Cell suspensions

Blut, 1977 Jan, 34(1), 49 - 52
A mofidied method for measuring the filtrability of erythrocytes; Imre S; A modified method based on Teitel's original procedure for measuring the filtrability of erythrocytes was described . The filter paper was not placed into a funnel but to the exit at the bottom of a 2 ml glass column . The filtration of the red cell suspension was quantitated by measuring the decrease of the volume in the column.

J Immunol, 1977 Jan, 118(1), 146 - 50
Immunologic reactivity of the lung . III . Effects of corticosteroids on alveolar macrophage cytotoxic effector cell function; Hunninghake GW et al.; The effects of various in vitro and in vivo regimens of corticosteroid administration on guinea pig alveolar macrophages were studied . Corticosteroid-induced immunosuppression was assessed by the effect of drug administration on the total numbers and functional capabilities of alveolar macrophages as measured by the PHA-induced and antibody-dependent cellular cytotoxicity assays against sheep red blood cell targets . In vivo administration of either hydrocortisone sodium succinate (100 mg/kg/one dose) or cortisone acetate (100 mg/subcutaneously for 7 days) caused a marked increase in the numbers of alveolar macrophages recovered from the teased lung cell suspensions and 4 and 24 hr, respectively, after the last injection . Both regimens of corticosteroid administration cause similar levels of peripheral blood lymphocytopenia and monocytopenia, 4 and 24 hr, respectively, after the final injection . Neither in vitro hydrocortisone (0, 1, and 10 mug/ml), nor hydrocortisone (100 mg/kg), in vivo had any effect on either the PHA-induced or antibody-dependent cellular cytotoxicity of alveolar macrophages . In marked contrast, cortisone acetate, depo-preparation which gives sustained elevations of plasma cortisol levels similar to those found for a brief period after i.v . injection of hydrocortisone caused a marked decrease in cytotoxic effect on function of alveolar macrophages suspensions . In a separate experiment, the suppressed killer cell function of the alveolar macrophages from steroid-treated animals was found not to be related to an intrinsic defect in killing of bound target cells since the defect in killing could be overcome by increasing the density of antibody and PHA on the target cells.

Neuroendocrinology, 1977, 24(3-4), 232 - 40
Acute decrease of blood thyroid hormone by isovolemic exchange transfusion as a stimulus for pulse TSH release and its modifications by CNS Lesions; Langer P et al.; The level of thyroid hormone in blood has been acutely decreased by about 20--30% within 20 min with the aid of isovolemic exchange transfusion (IET) of thyroid hormone free blood cell suspension (THFBCS) in three groups of rats: (1) intact control (C); (2) median eminence (ME)-lesioned; (3) thalamus (TH)-lesioned . The levels of thyroxine (T4) and TSH were measured by specific radioimmunoassay (RIA) before the transfusion and for 180 min after that . The level of T4 increased to the initial value at about 120 min after IET in C and ME-lesioned rats, while in TH it remained decreased until 180 min . Furthermore, at the end of IET the level of TSH in C and ME-lesioned rats was about 2--3 time higher than the initial value and its continuous decrease was observed until 180 min . In contrast, in TH-lesioned rats the increase of TSH level was delayed, being significant at 60 min only . It was concluded that IET of THFBCS acts as a stimulus of acute TSH release which was remarkably inhibited in TH-lesioned animals . In addition, the destruction of most of the ME did not apparently influence this response, as shown by essentially similar data obtained in C and ME-lesioned rats.

Scand J Immunol, 1977, 6(12), 1251 - 61
Antibody-dependent cytotoxicity mediated by cells eluted from synovial tissues of patients with rheumatoid arthritis and juvenile rheumatoid arthritis; Abrahamsen TG et al.; Cell suspensions containing an average of 78% lymphocytes were obtained from synovial tissues of 26 patients with rheumatoid arthritis and 10 patients with juvenile rheumatoid arthritis . These cells were shown to mediate cytotoxicity against 51Cr-labeled chicken erythrocytes sensitized with a rabbit anti-chicken erythrocyte antiserum . Nylon column filtration of the cells increased the proportion of lymphocytes and usually also the cytotoxicity, which suggested that at least some of the effector cells were lymphocytes . The cytotoxic activity of the cells obtained from rheumatoid synovial tissue was always lower than that obtained with the patients' peripheral blood lymphocytes . No significant change in cytotoxicity of normal peripheral blood lymphocytes was observed after these cells had been treated in the same manner as the rheumatoid synovial tissues.

Am J Hematol, 1977, 3, 237 - 44
The use of filtration techniques for the lysis and study of red blood cells; Hultquist DE et al.; A filtration technique for the gentle lysis of erythrocytes has been developed using cellulose triacetate membranes . When cell suspensions are filtered under nitrogen pressure, lysis occurs at the surface of the filter in such a way that the cell ghosts are retained on the filter . The contents of the cell are extruded through the pores of the filter without mixing with the cell suspension . Cell ghosts and intact erythrocytes have been collected on membranes and examined by electron microscopy . These preparations have the advantage of being free of the structural artifacts that result from centrifugation . In addition, the filter facilitates preparation for electron microscopy by providing a support for the sample during fixation and then dissolving during the dehydration of the sample.

Acta Biol Med Ger, 1977, 36(3-4), 543 - 8
{Viability, ATP and 2,3-DPG content of resuspended erythrocytes during several-week storage in cold}; Strauss D et al.; Leukocyte-and thrombocyte-poor packed red cells obtained from ACD or . ACD-AG blood were resuspended to a hematocrit of about 55% and stored at 4 degrees C . The resuspension solution consisted of xylitol, inorganic phosphate, bicarbonate, adenine (A) and guanosine (G) solved in water . In one case glucose, citrate and sucrose were also added, in another one, sorbitol . The 2,3-DPG and the ATP level remained for a longer period in the sorbitol-xylitol-medium than in the glucose-xylitol-medium . The ATP content in the red cell suspension was higher than in packed cells . Higher ATP values were obtained in red blood cells from whole blood with adenine and guanosine . The survival rate of resuspended red blood cells in glucose-AG-citrate-sucrose medium was about 80--85% after 3 weeks of storage and 77% after 6 weeks with a higher range.

Folia Biol (Praha), 1977, 23(4), 235 - 42
Action of A RNase and AS RNase on growth of cells in vitro; Cinatl J et al.; The effect of bovine pancreatic A RNase and bull seminal vesicle AS RNase on proliferation of HeLa cells and LEP cells in vitro was studied . The ribonucleases were used in doses of 0.1, 1.0, 10.0, and 100.0 microgram per ml of medium and 100 000 inoculated cells . Proliferation was evaluated by the growth curves . Both in single and long-term experiments . A RNase in all doses used had no effect on cell proliferation, whereas AS RNase exerted inhibitory activity beginning with the dose of 10 microgram, and affected more markedly the LEP cells (a diploid non-malignant cell line) than the malignant heteroploid HeLa cells . When added to the cell suspension, AS RNase was shown by indirect immunofluorescence to bind to HeLa cell membranes in all phases of growth, whereas AS RNase was found on membranes of LEP cells only when they were derived from the log phase of growth.

Am J Pathol, 1977 Jan, 86(1), 123 - 31
Glucose-6-phosphate dehydrogenase isoenzymes in acinar epithelial cells separated from the mammary gland of the rat at intervals during the course of lactation; Scalise MM et al.; Acinar epithelial cells were purifed from suspensions of cells from the lactating mammary glands of rats . As described previously, this purififaction was accomplished by sedimentation in an isokinetic gradient of Ficoll (polysucrose) in tissue culture medium, and the purity of the separated cells was established by electron microscopy and by histochemical markers . Isoenzymes of glucose-6-phosphate dehydrogenase were investigated at various intervals during lactation in separated populations of stromal and acinar cells . Acinar cells contained three- to eightfold more glucose-6-phosphate dehydrogenase activity than did stromal cells . The proportions of the respective isoenzymes varied during the course of lactation, and the observed changes were parallel in purified acinar cells and in the lactating mammary glands from which the cell suspensions were obtained . The availability of purified acinar cells in the investigation of interactions between hormones and cells from the mammary gland permits a greater degree of specificity than has been possible in the study of mammary cell suspensions which contain myoepithelial cells, duct cells, acinar cells, endothelial cells, fibroblasts, fat cells, mast cells, plasma cells, and blood cells.

Biull Eksp Biol Med, 1977 Jan, 83(1), 73 - 5
{Changes in the immunologis status of the body during carcinogenesis detected by the physico-chemical characteristics of cells of the immunocompetent system}; Stepanova EN et al.; The state of cell population of the lymph nodes and the thymus was studied on a model of rat sarcoma of the hip(induced by dimethlbenzanthracene) by the method of fluorescent sounds . Statistically significant changes of incorporation of the negatively charged sound 1-anilino-8-naphthalinosulfonate (ANS) into cell suspension, depending on the stage of sarcoma development, were detected . The appearance of cell forms with a lesser hydrophobic character of the surface and with less binding points for the ANS were noted at the early carcinogenesis periods . It is supposed that these cells were referred to immature ones . A conclusion was drawn on the applicability of the method of fluorescent sound for recording changes in the immunological state of the organism in carcinogenesis.

Microbios, 1977, 19(75), 17 - 26
Effect of phenoxyethanol on the permeability of Escherichia coli NCTC 5933 to inorganic ions; Gilbert P et al.; Concentrations of phenoxyethanol which retarded the growth rate of Escherichia coli NCTC 5933 in nutrient broth, stimulated the rates of respiration and total oxygen uptake of cell suspensions with glucose as carbon source, and were able to dissipate artificially induced membrane proton gradients . In cells with repressed oxidative phosphorylating activity, no stimulation of respiration was observed . These actions were characteristic of uncouples of oxidative phosphorylation . Similar concentrations of the drug caused additional increased permeability of the cytoplasmic membrane to K+ but not to Li+, Na+, Ca++, Mg++, NO-3, Cl-, So--4, or PO---4 . Drug induced permeability of the membrane to protons and potassium ions were not found to be directly coupled.

Scand J Immunol, 1977, 6(12), 1305 - 15
Studies of antibody-dependent cytotoxicity in a plaque assay: evidence of human monocyte-like effector cells; Thorsteinsson L et al.; Two different methods for evaluating 'in vitro' cytotoxicity against antibody-coated target cells mediated by mononuclear leukocytes were compared . One was a plaque assay for identification of the cytotoxic cell and the other the classical chromium release assay for antibody-dependent cytotoxicity (ADCC) . A marked decrease in plaque-forming cells (PFC) was observed in a cell suspension depleted of peroxidase-positive cells and cells with membrane-bound Ig (B lymphocytes) by fractionation on a nylon fiber column . In contrast, the ADCC activity was considerably increased by these depletions . A similar effect was obtained by removal of phagocytic cells with iron . These results, together with the observations after depletion of E-RFC (T lymphocytes) or EA-RFC (Fc-receptor-bearing cells), suggest that the PFC in the assay system used were of monocytic origin and differnet from the cells responsible for the ADCC.

Int Arch Allergy Appl Immunol, 1977, 55(1-6), 131 - 4
Role of T and adherent cells in in vitro response of nude mouse spleen cells to bacterial lipopolysaccharide; Takigawa M et al.; Thy 1.2-positive cells and adherent cells were depleted from nude mouse spleen cell suspensions by treatment with anti-Thy 1.2 antisera plus complement and by passage through Sephadex G-10 column, respectively . The results of 3H-TdR uptake and appearance of IgM containing cells induced in vitro by lipopolysaccharide (LPS) were similar in both untreated and depleted spleen cells . Our findings confirm T and adherent cell independence of LPS response in nude mice.

J Immunol Methods, 1977, 17(3-4), 329 - 36
A direct hemolytic plaque assay on polylysine-coated coverslips for scanning electron microscopy of antibody forming cells; Pan S et al.; A direct immunoplaque assay was utilized without agar or other semi-solid matrix for examining antibody secreting cells by scanning electron microscopy . For this purpose a polylysine procedure was used whereby 'charged' coverslips absorbed onto their surface an even monolayer of target sheep erythrocytes . Hemolysin secreting splenocytes derived either from mice immunized in vivo with SRBC or from normal or primed splenocytes immunized in vitro with the same antigen formed large numbers of hemolytic plaques on the RBC-coated polylysine treated coverslips . SEM examination of such plaque-forming cells revealed the presence of cells with the typical surface morphology of lymphocytes present in whole spleen cell suspensions . Many of the lymphocytes were covered with numerous microvilli while a small percentage were relatively free of such villi and exhibited a much smoother surface . Examination of lymphocytes secreting hemolytic antibody on polylysine coated coverslips sensitized with target erythrocytes thus permits the direct examination and analysis of surface morphologic features and also permits a direct comparison with other features revealed by light and fluorescent microscopy.

J Pathol, 1977 Jan, 121(1), 1 - 8
Characteristics of mononuclear cell populations in chronically inflamed synovial membranes; Meijer CJ et al.; Mononuclear cells infiltrating synovial membranes in chronic synovitis were characterised both in situ and in cell suspensions by surface markers and histochemical techniques . T-lymphocytes were the predominant infiltrating cell in rheumatoid arthritis as well as in other forms of chronic arthritis, including ankylosing spondylitis and arthritis associated with Crohn's disease . B-lymphocytes were found exclusively in rheumatoid synovial membranes . These cells were demonstrable both in true germinal centres and, focally and diffusely, in nodular mononuclear infiltrates lacking the histochemical characteristics of germinal centres . The synovial lining cells, unlike mononuclear phagocytes, had no demonstrable receptors for C3 and Fc.

Int Arch Allergy Appl Immunol, 1977, 54(4), 364 - 73
Experiments on the passive sensitization of human basophils, using quantitative immunofluorescence microscopy; Stallman PJ et al.; In previous experiments a correlation was found between the amount of IgE on human basophils and the IgE serum level . The results of these experiments are shown to fit a free exchange model with an approximately constant K-value . We investigated whether the free IgE-receptors on the basophils, which should be present according to this model, could be saturated by incubating the cell suspensions with IgE myeloma protein or with sera from patients with an elevated IgE serum level . Various incubation conditions were applied in sensitizing the leukocytes, and cells from both atopic and nonatopic subjects were used for testing, but no increase in basophil-bound IgE could be measured with the quantitative immunofluorescence technique . Nor could we demonstrate a significant dissociation of cell-bound IgE in a period of 24 h . Therefore another hypothesis is put forward, in which receptor turnover is taken into account: we assumed that that free receptors on the basophils had a shorter functional half-life, than the half-life of the IgE-receptor complexes . This model would explain the contradictory results mentioned above.

Microsc Acta, 1977 Jan, 79(1), 43 - 5
The use of porous plastic filters in the preparation of cell suspensions; Pearce FL; Suspensions of cells were prepared by dissociation of various tissues with the proteolytic enzyme pronase . Debris, undisrupted tissue and cell clumps were effectively removed from the suspensions by passage through VYON F porous plastic filters whereas isolated cells were recovered without significant losses . The viability of the cells, as judged by dye exclusion and subsequent behavior in tissue culture, was not affected by the treatment.

Bull Cancer, 1977, 64(2), 225 - 40
Morphological and functional differentiation and classification of cutaneous lymphomas; Burg G et al.; It was the purpose of our studies to achieve reevaluation of the histo- and cytomorphology of cutaneous lymphomas by means of additional enzymecyto-chemical and funtional tests . Skin biopsy specimens from 99 patients with cutaneous lymphomas and pseudolymphomas were stained for HE, Giemsa, PAS, Gormori, several hydrolytic enzymes and peroxidase . In cell suspensions extracted from skin lesions B and T cell differentiation was performed using surface markers . In addition tissue cells were tested for PHA response in suspensions and for intracytoplasmatic Ig on smears . Based on these studies cutaneous lymphomas were filed, within the "Kiel" classification of low grade and high grade malignant lymphomas according to their histological, enzymecytochemical and immunological features . It got evident that B cell and T cell lymphomas of low grade malignancy in the skin both present distinct histological patterns, indicating areas B and T cell microenvironmental specificity.

J Immunol Methods, 1977, 16(1), 1 - 13
Optimal conditions for the separation of rat T lymphocytes on anti-immunoglobulin--immunoglobulin affinity columns; Kondorosi E et al.; The separation of rat T lymphocytes was investigated on anti-Ig--Ig columns . A simple and efficient method for the purification of rat Ig by precipitation of rat serum with sodium sulfate is presented . Protein binding characteristics of glass and plastic beads, as solid support of affinity columns, are described, as well as optimal parameters for coating beads with rat Ig (with BSA, ribonuclease and lysozyme, as comparison) . Binding of Ig was primarily dependent on the concentration of the Ig solution . Maximal strong binding of Ig (6.2 X 10(3) molecules per micron2 of bead surface) was reached a 400 microng per ml concentration of purified Ig solution during 20 min of incubation . Higher concentrations increased only the amount of loosely bound Ig on the surface of beads whereas the amount of firmly bound Ig remained unchanged . Fractionation of lymphoid cell suspensions on anti-Ig--Ig affinity columns prepared at optimal conditions resulted in highly purified T-cell suspensions containing less than 1% of lymphocytes bearing surface Ig receptors.

Ann Immunol (Paris), 1977 Jan-Mar, 128(1-2), 47 - 9
{Cellular interaction in the pokeweed-mitogen induced terminal differentiation to polyclonal immunoglobulin production in human B lymphocytes in vitro}; Robert M et al.; The differentiation of human B lymphocytes in vitro into Ig secreting cells, as measured by a radioimmunoassay rendered specific to IgG and IgM, in response to a polyclonal stimulant, requires the participation of several cellular types . Upon poleweed-mitogen stimulation, B-cell enriched and monocyte containing cell suspensions prepared by elution of nylon wool adherent cells, when mixed with various concentrations of T cells purified by filtration through nylon wool column and depletion of EAC-rosette forming cells, synthesize 5 to 20 times more Ig than non separated lymphocytes . These experiments which demonstrate the cooperation of certain T cells also suggest that other cells eliminated by nylon wool adherence act as suppressor cells . The cooperation of these T cells is independent of their proliferation and can be obtained with allogeneic T cell.

Transfusion, 1977 Jan-Feb, 17(1), 16 - 22
A method for radioactive antiglobulin testing with 125I labeled anti-IgG; Jenkins DE Jr et al.; The present report describes a method for 125I anti-IgG antiglobulin testing . The method involves the use of a labeled DEAE cellulose IgG fraction of goat anti-human IgG globulin . Leukocyte-free red blood cells were used in the test procedure . Both the labeled antiserum and the red blood cell suspensions were diluted in normal rabbit serum to prevent non-specific uptake of labeled antiserum by normal, uncoated red blood cells . The results of the study show that the method is highly reproducible and relatively easy to perform once the labeled anti-IgG is prepared . Furthermore, the use of labeled antiserum permits analysis of antiserum specificity by radioimmunoelectrophoresis . The problem of determining anti-IgG/IgG binding ratios remains the major disadvantage to using the method to determine precise amounts of human IgG coating red blood cells.

Physiol Chem Phys, 1977, 9(6), 533 - 8
Effect of haemagglutinating virus of Japan on the potassium compartmentation and the membrane potential of human erythrocytes; Utsumi K et al.; HVJ induces release of potassium and changes in membrane potential of certain types of cells . These changes are quite dependent on incubation temperature and are inhibited by the addition of con A to cell suspensions prior to the addition of viruses.

Endocr Res Commun, 1977, 4(2), 159 - 69
An improved bioassay for ACTH determination; Liotta AS et al.; An improved method for the bioassay of ACTH has been developed using short-term culture of adrenal cell suspensions derived from intact rats . Six separate pools of adrenals were used and cells derived from the same pool were compared after acute dispersion and overnight culture . The ED50, defined as the concentration of ACTH required to produce half maximal steroidogenesis, for cultured cells was 35.4+/-2 pg/ml compared to 240+/-60 pg/ml for cells used immediately after dispersion . The minimum concentrations of ACTH necessary to produce a response significantly above basal levels were 0.98+/-.10 pg/ml and 12.1+/-3 pg/ml respectively . Response characteristics of the cultured cells were highly reproducible . The incubation volume employed in this study was 0.25 ml, so the ED50 expressed as dose of ACTH per tube was actually 8.8 pg for the cultured cells . Such sensitivity provides requisite methodology for the measurement of ACTH under varying physiological conditions.

Prostaglandins, 1977 Jan, 13(1), 25 - 31
Cyclic AMP response to prostaglandin E1 in mononuclear cells from peripheral blood and synovial fluid of patients with rheumatoid arthritis; Zurier RB et al.; The cyclic AMP response to prostaglandin E1 (PGE1) was studied in peripheral blood (PB) and synovial fluid (SF) mononuclear cells from patients with rheumatoid arthritis (RA) . The PGE1 induced accumulation of cyclic AMP was consistently (7 of 8 patients) less in cell suspensions derived from SF than in suspensions of equivalent numbers of mononuclear cells obtained simultaneously from PB . The high PB/SF cyclic AMP ratio was seen most clearly at the lowest concentration (10(-6)M) of PGE1 tested . There was no correlation between the patients' therapy and cyclic AMP response to PGE1 . The high PB/SF cyclic AMP ratio was not accounted for by the presence of platelets in PB cell suspensions.

Transplantation, 1977 Jan, 23(1), 53 - 9
Mixed heart cell-lymphocyte reactions and graft survivals in Ag-B-compatible rats; Kashiwabara H et al.; A method of dissociation of the rat heart cell for the mixed lymphocyte culture purpose is described . The treatment of the young rat heart with 0.1% collagenase-hyaluronidase solution yielded satisfactory heart cell suspension . The hear cells, thus obtained after mitomycin C treatment but not irradiation, stimulated allogeneic lymphocytes in the presence of 2-mercaptoethanol . In the Fischer to Lewis combination compatible at the Ag-B locus, strong reactions of Lewis lymphocytes to the dissociated heart and skin cells of the Fischer rat were related to the acute rejection of heart and skin grafts, while negative reactions by the kidney and spleen cells reflected a prolonged survival of the kidney graft . The role of skin- and hear-specific antigens in the rejection phenomenon is discussed.

J Bioeng, 1977 Jan, 1(2), 61 - 77
The preferential adsorption of hemoglobin to polyethylene; Horbett TA et al.; Hemoglobin adsorption to foreign surfaces has not previously been considered in studies of blood-material interactions, despite the fact that hemoglobin is the most abundant protein present in blood . A hemoglobin-like protein was detected on a number of surfaces exposed to blood plasma, serum, and red cell suspensions . Hemoglobin adsorption to polyethylene from plasma was found to approximately equal the amount of adsorption of albumin and fibrinogen . The high relative affinity of hemoglobin for polyethylene was further confirmed by adsorption isotherm and direct competition experiments . The data from all four experimental methods support the following ranking of plasma protein affinity for polyethylene: Hemoglobin greater than fibrinogen greater than albumin congruent to gamma-globulin.

Vox Sang, 1977, 33(5), 257 - 65
Preparation and specificity testing of a rabbit anti-human thymocyte serum (with 1 colour plate); Brutel de la Riviere A et al.; The preparation of a specific anti-T cell serum, applicable in the indirect immunofluorescence technique on cell suspensions, smears of peripheral blood and bone marrow and on tissue sections is described . Rabbits were immunized with thymocytes; after removal of antibodies against species-specific antigens and antigens common to leucocytes by absorptions with red cells and granulocytes, specificity for thymocytes was obtained by repeated absorptions with CLL cells, used as B cell equivalents . Subsequently, the IgG fraction of the absorbed antiserum was isolated . This antibody preparation was tested with various types of blood cells as well as with cell suspensions depleted or enriched in T cells . For the study of tissue sections it had to be absorbed with liver powder . When studying lymphatic tissue it was found to stain only thymus-dependent areas in the specimens tested.

J Immunol Methods, 1977, 15(3), 291 - 7
Temperature dependence of antigen-specific rosette formation by lymphocytes from immunised mice; Wansbrough-Jones M et al.; Spleen cell suspensions from mice undergoing a secondary response to sheep erythrocytes (SRBC) contained about one tenth as many specific antigen-binding, rosette-forming cells (RFC) when they had been washed at 37 degrees C instead of 4 degrees C before rosetting . This difference was correlated with the presence of IgG anti-SRBC antibody in the serum, and the 37 degrees C washings of immunised spleen cells could passively allergise non-immune spleen cells at 4 degrees C for specific rosette formation which was inhibitable by anti-mouse F(ab)2 serum . The RFC from actively immunised mice were lymphocytes and not macrophages by morphological and cytochemical criteria . It is suggested that the 37 degrees C-labile RFC are lymphocytes to which IgG antibodies bind in the cold . These data indicate that in the use of antigen-binding cell assays to monitor immunological responses, it is necessary to wash lymphocytes at 37 degrees C before testing.

Ann Immunol (Paris), 1977 Jan-Mar, 128(1-2), 137 - 9
{H-2 specificity and auto-reactivity of autologous rosette-forming cells from adult thymectomized mice spleen cells}; Charreire J et al.; We have previously shown that the number of autologous rosette-forming cells (A-RFC) found in adult thymectomized mice (A-Tx) spleens was 15 times higher than that found in spleens of intact controls . We have therefore investigated both the specificity of A-RFC and their relationship with autoreactivity . Immunoadsorption experiments showed that while the incubation on allogeneic monolayers did not bring any modification in A-RFC levels . This result suggests that the formation of autologous rosettes is the manifestation of a true recognition event associated with the H-2 complex . A-Tx mice spleen cells injected into syngeneic recipients induced an enlargement of the afferent popliteal lymph node (LN) . Ficoll-Triosil A-RFC depleted A-Tx spleen cells lost their capacity to induce this popliteal proliferation . Conversely, A-RFC recovered spleen cell suspensions obtained from the pellet of the Ficoll Triosil gradient kept their capacity of inducing auto-reactivity . Thus, it seems that A-RFC and lymphocytes stimulating the afferent LN belong to the same sub-population.

J Immunol Methods, 1977, 14(3-4), 267 - 9
Rapid identification of monocytes in a mixed mononuclear cell preparation; Tucker SB et al.; A method for identifying monocytes by the "non-specific esterase" stain is described . This method is particularly applicable to mononuclear cell suspensions obtained by Ficoll--Hypaque density gradient separations and allows rapid as well as accurate determinations.

Dev Biol Stand, 1976 Dec 13-15, 37, 235 - 40
The testing of cell invasiveness in embryonic tissue and in cell culture; Ikic D et al.; The subcutis of 11-day-old chick embryos, 15- to 18-day-old mouse embryos and the skin muscle tissue of human fetus were stretched on lens paper in a Petri dish and seeded with a piece of LED-Widr or HDC cell sheet . Mem + 10% FCS was added . After three days incubation the material was fixed, sectioned and H-E stained . In the second part of our investigation several cell lines were prepared on cover slips . When confluent, the cultures were inoculated with 1-2 drops of cell suspension of another cell line . Three days after the seeding of cell suspension on the confluent cell sheet the cultures were fixed and stained . It can be seen in the organ cultures that LED-Widr cells closely adhere to the embryonic tissue which in some places they are invading . In tissue culture examination we found that heteroploid cells seeded on a confluent sheet of diploid cells adhered but that a diploid cell seeded on epithelial-like heteroploid cells would not adhere . The testing of invasiveness in embryonic tissue in organ culture showed that it can be a useful model . By seeding suspended cells of fibroblast lines on a confluent sheet of heteroploid cell lines their contact inhibition or their invasive ability can be determined . The seeding of heteroploid cell lines on diploid cell lines can be used as a model for the study of the mechanism of invasion into normal tissue and for the in vitro study of invasion inhibiting properties of certain substances.

Aust J Biol Sci, 1976 Dec, 29(5-6), 443 - 51
Preparation of metabolically active cell suspensions from wool roots; Ward KA; A method is described for the preparation of metabolically active cell suspensions from plucked wool roots using the proteolytic enzyme trypsin . The suspensions consist of a heterogeneous population of cells which appear similar in morphology to follicle bulb cells, differentiating keratinocytes and possibly cells of the inner root sheath . The concentrations of trypsin and of inorganic ions for optimum activity of the suspensions have been determined, and the inclusion of EGTA was found to increase the yield of cells . The cell suspensions incorporate {14C}leucine, {3H}uridine and {3H}thymidine into acid-insoluble products, and are sensitive to the action of cycloheximide and emetine, but not to chloramphenicol or rifampin . Autoradiography has shown that the cells believed to be derived from the follicle bulbs show the greatest activity.

J Cell Sci, 1976 Dec, 22(3), 657 - 70
Assay of intercellular adhesiveness using cell-coated Sephadex beads as collecting particles; Vosbeck K et al.; A simple, rapid and precise method, based on a previous method, for measuring relative rates of intercellular adhesion is described . DEAE-Sephadex beads were treated with nitrocellulose in order to allow cells to grow on their surfaces . Balb/c 3T3 and Balb/c 3T12 cells were used to characterize the assay . They formed confluent cell layers on nitrocellulose-treated DEAE-Sephadex . These cell-coated beads were employed to collect 32P-labelled cells from single cell suspensions . Since they formed statistically uniform, large collecting surfaces, the collection of labelled cells was markedly improved as compared to the original assay . The cell-coated beads collected a large percentage of the labelled cells in a short time . The percentage of cells collected was independent of the concentration of labelled cells in the assay mixture, and the collection was linear for approximately 60 min . The variability between replicate assays was usually +/- 5% . The assay allows the rapid and precise determination of intercellular adhesion in large numbers of individual samples . These features make it useful to screen for effects of different treatments on intercellular adhesions.

Arch Microbiol, 1976 Dec 1, 111(1-2), 137 - 44
Growth of Hansenula polymorpha in a methanol-limited chemostat . Physiological responses due to the involvement of methanol oxidase as a key enzyme in methanol metabolism; van Dijken JP et al.; Hansenula polymorpha has been grown in a methanol-limited continuous culture at a variety of dilution rates . Cell suspensions of the yeast grown at a dilution rate of 0.16 h-1 showed a maximal capacity to oxidize excess methanol (QmaxO2) which was 1.6 times higher than the rate required to sustain the growth rate (QO2) . When the dilution rate was decreased to 0.03 h-1, QmaxO2 of cells increased to a value of more than 20 times that of QO2 . The enzymatic basis for this tremendous overcapacity for the oxidation of excess methanol at low growth rates was found to be the methanol oxidase content of the cells . The level of this enzyme increased from 7% to approximately 20% of the soluble protein when the growth rate was decreased from 0.16 to 0.03 h-1 . These results were explained on the basis of the poor affinity of methanol oxidase for its substrates . Methanol oxidase purified from Hansenula polymorpha showed an apparent Km for methanol of 1.3 mM in air saturated reaction mixtures and the apparent Km of the enzyme for oxygen was 0.4 mM at a methanol concentration of 100 mM . The involvement of an oxygen dependent methanol oxidase in the dissimilation of methanol in Hansenula polymprpha was also reflected in the growth yield of the organism . The maximal yield of the yeast was found to be low (0.38 g cells/g methanol) . This was not due to a very high maintenance energy requirement which was estimated to be 17 mg methanol/g cells X h.

Arch Microbiol, 1976 Dec 1, 111(1-2), 111 - 5
Induction of D-6-hydroxynicotine oxidase in resting cells of Arthrobacter oxidans; Reeves HC et al.; Resting cell suspensions of Arthrobacter oxidans were shown to synthesize the inducible enantiozyme, D-6-hydroxynicotine oxidase, in the presence of D-nicotine or D-6-hydroxynicotine . The corresponding L-enantiomers, as well as gamma-methylaminopropyl-(6-OH-pyridyl-3)-ketone, which is the product of the reaction catalyzed by the enzyme, were ineffective as inducers . L-6-Hydroxynicotine inhibited induction by D-nicotine and D-6-hydroxynicotine while L-nicotine inhibited induction by D-6-hydroxynicotine and had no effect on induction by D-nicotine . Enzyme induction was also found to be inhibited by glucose, 2-deoxy-D-glucose and by several intermediates of the tricarboxylic acid cycle . An absolute requirement for protein synthesis and for oxygen was also demonstrated to be necessary for the reactions involved in the covalent attachment of flavin adenine dinucleotide to pre-existing precursor protein to yield the catalytically active D-6-hydroxynicotine oxidase.

Br J Cancer, 1976 Dec, 34(6), 619 - 25
Stimulation of autologous blood lymphocytes by malignant lymphoma cells and homogenates; Ludgate ME et al.; The blastogenic response to autologous blood lymphocytes to whole-cell suspensions and to homogenates obtained from malignant lymphoma tissue has been investigated . Spleens were obtained from patients in whom laparotomy was performed for staging of malignant lymphoma . Cell suspensions prepared from tumour nodules were treated with mitomycin C and allowed to react with separated autologous blood lymphocytes for 6 days . Lymphocyte stimulation was measured by liquid scintillation counting after exposure to 3H-TdR . Cultures were also prepared in which autologous lymphocytes were treated with spleen tumour homogenate . Control experiments used spleens from staging procedures in which no tumour deposits were present, and normal spleens removed incidentally during other operations . In the controls, the uptake of TdR was never more than twice that of unstimulated lymphocytes . Greater degrees of lymphocyte stimulation were seen in 6 out of 14 patients, using whole tumour cells, and in 7 out of 16 patients, using tumour homogenates . The results indicate an antigenic difference between tumour and host cells, and suggest that lymphocytes can react to a tumour-associated antigen.

Lab Invest, 1976 Dec, 35(6), 550 - 7
Tissue factor in cultured cells: pharmacologic effects; Maynard JR et al.; Tissue factor activity in suspension cultures of WISH amnion cells is modulated by pharmacologic doses of agents which alter membrane structure and function . Lysosomal stabilizing steroids (hydrocortisone, dexamethasone, aldosterone, prednisolone, and estradiol) suppress the change in activity which follows subculture; lytic steroids (testosterone and progesterone) are ineffective . Chloroquine both increases the specific activity and extends the time before return to the basal level . Dimethyl sulfoxide and ouabain suppress the complete expression of activity but do not inhibit the subsequent decay . The effect of cytochalasin B is complex, the drug being either suppressive or slightly stimulatory depending on the time of addition . Cyclic nucleotides (AMP or GMP) or insulin do not regulate the expression of tissue factor in these cells . A dramatic increment and prolongation of activity occurs when colchicine or vinblastine is added to the cell suspension shortly after subculture; there is much less stimulation by griseofulvin . Lumicolchicine has no effect while deuterium oxide is inhibitory . From these experiments, we conclude that increased membrane fluidity or altered secretory processes resulting from microtubule disruption stabilize tissue factor in cultured cells . Since contradictory results were obtained with agents which stabilize lysosomes or inhibit transport, the role of these cellular functions in tissue factor production or decay is unclear.

J Cell Biol, 1976 Dec, 71(3), 921 - 32
Effects of glutathione-oxidizing agents on microtubule assembly and microtubule-dependent surface properties of human neutrophils; Oliver JM et al.; In human peripheral blood polymorphonuclear leukocytes and lymphocytes, GSH-oxidizing agents promote the movement of surface-bound concanavalin A (Con A) into caps and inhibit the assembly of microtubules (MT) that is normally induced by Con A binding . Con A capping and inhibition of MT assembly occur when GSH levels in cell suspensions are decreased by 30-70%, and return to GSH to control levels is accompanied by the appearance of cytoplasmic MT and by inhibition of the capping response with Con A . Oxidation of GSH markedly stimulates the hexose monophosphate shunt, and regeneration of GSH occurs rapidly . The data indicate that MT cannot be assembled or maintained in the face of decreased GSH levels . Thus, GSH homeostasis becomes critical during physiological events such as phagocytosis which simultaneously induce the assembly of MT and the production of agents like H2O2 that can oxidize GSH.

Ann Med Interne (Paris), 1976 Dec, 127(12), 865 - 72
{Morphologic criteria of surface studies by electron microscopy and classification of lymphoproliferative syndromes . Critical study}; Reyes F et al.; Surface associated immunoglobulins (s.Ig) have been detected on human lymphocytes, in normal individuals and in disease, by an immunoelectron microscopic method using peroxidase-labeled antibodies . Experiments have been carried out on fixed cell suspensions, in order to avoid membrane alterations induced by anti-immunoglobulin antibodies . Normal human blood B lymphocytes have a villous surface . However this relationship between microvilli and detectable s.Ig, as found in the normal state, is not confirmed by examinating various T and B cell proliferative states . Thus surface morphology alone is not sufficient for classifying cells in disease . The precise nature of mononuclear cells from hairy cell leukemia remains nuclear.

Arch Microbiol, 1976 Dec 1, 111(1-2), 73 - 6
Spectroscopic properties and related functions of the stigma measured in living cells of Euglena gracilis; Benedetti PA et al.; The spectroscopic properties of stigma inside green and dark-grown cells and of isolated stigma globules have been studied by means of a microspectrophotometer build in the Laboratory . On the base of these results and of the analysis of the absorption spectra of a stigma suspension, cell suspension and the cell methanolic extracts, it can be inferred that pigments localized in the stigma are free carotenoids which are not closely packed and do not show an ordered arrangement . Furthermore, the efficiency of the stigma as shading device is duscussed.

Am Rev Respir Dis, 1976 Dec, 114(6), 1099 - 105
Characterization of immunocompetent cells recovered from the respiratory tract and tracheobronchial lymph node of normal guinea pigs; Gorenberg DJ et al.; To gain insight into the structure of the lung's immune system, the identity and function of immunocompetent cells in the broncho-alveolar air spaces and tracheobronchial lymph nodes of normal guinea pigs were examined . Guinea pig thymus-derived (T) lymphocytes (mediators of cellular immunity) were identified by their ability to form rosettes with rabbit erythrocytes (E rosettes) . Bone marrow-derived (B) lymphocytes (mediators of humoral immunity) were identified by their ability to form rosettes with sheep erythrocytes sensitized with antibody and complement (EAC rosettes) and by the presence of surface immunoglobulin, detected by direct immunofluorescence . Total lung lavage yielded 14+/-5.0 X 10(6) (mean +/- SD) cells . There were 68+/-5 per cent cells of the monocyte-macrophage series as judged by morphology, the ingestion of latex particles, and the uptake of neutral red; 20+/-9 per cent were eosinophils, and 12+/-5 per cent were lymphocytes . Stable populations of T and B lymphocytes were recovered from guinea pig airways and tracheobronchial lymph nodes . T cells represented 76 per cent of lymphocytes from the airways and 64 per cent of lymphocytes in tracheobronchial lymph node; B cells equalled 14 per cent and 30 per cent, respectively . The functional potential of T cells present in the lung and tracheobronchial lymph node was demonstrated by their proliferative response to phytohemagglutinin . These results indicated that, although macrophages are the predominant cell type, viable T and B lymphocytes are present in the guinea pig broncho-alveolar air space . The composition of these cells is comparable to what has been observed in normal human lungs and provides preliminary evidence that the guinea pig may be a useful model for humans . This report also describes a method using 2 vital stains whereby macrophages, lymphocytes, and rosetted lymphocytes can be distinguished in unseparated cell suspensions prepared from bronchial aspirates.

Acta Pathol Microbiol Scand {C}, 1976 Dec, 84C(6), 489 - 94
Freezing of rat lymphocytes . III . Freezing of plaque-forming cells and restoration by frozen-thawed normal cells of antibody production in irradiated rats; Hem E; The present investigation is an extension of earlier work with dimethyl sulphoxide (DMSO) protected frozen-thawed rat lymphocytes . In the present work it is shown that some 85-90% of the haemolytic plaque-forming cells (PFC) survived the freeze-thaw process . Irradiated rats were restored with fresh and frozen-thawed cells and immunized against sheep red blood cells (SRBC) . Evidence is presented that a restrictive control of the PFC response by suppressor cells present in the spleen cell suspension is lost during the freeze-thaw process, giving a higher number of PFC/spleen in recipients of frozen-thawed mixed spleen and lymph node cells than in rats receiving the corresponding fresh preparations.

Cancer, 1976 Dec, 38(6), 2296 - 309
The immune response at the tumor site in lung carcinoma; Ioachim HL et al.; The local immune response to lung cancer was investigated by histologic and immunologic means . Distinctive patterns of stromal cellular reaction, characteristic for different histologic types of lung carcinoma, were recognized . The amount of cellular infiltration was highest in squamous cell carcinomas and lowest or nonexistent in oat cell carcinomas . Within the various histologic categories the well-differentiated tumors appeared to be accompanied by more reactive cells than the poorly differentiated ones; there was no relation between tumor necrosis and cellular infiltration . The plasma cells were distinctly associated with squamous cell carcinomas; their number in the stroma was proportionate to the degree of differentiation and the presence of keratin produced by the tumors . Eluates with a high content of immunoglobulins were recovered from pleural effusions and from solid lung carcinomas by dissociation of antigen-antibody complexes . These preparations reacted positively in indirect immunofluorescence tests with tissue cultures and with fresh suspensions of lung carcinoma cells, but not with tissue culture cells of most nonpulmonary tumors or with cell suspensions of normal adult and fetal lung . Similarly prepared fractions of noncarcinomatous pleural effusions did not react with lung cancer cells.

Immunology, 1976 Dec, 31(6), 943 - 51
Analysis of immunosuppression generated by the graft-versus-host reaction . II . Characterization of the suppression cell and its mechanism of action; Shand FL; Spleen cells from (CBA X C57/BL) F1 mice undergoing graft-versus-host (GVH) reaction induced by injection of parental cells 7-14 days previously are capable of suppressing an immune response by normal or primed F1 spleen cells to chicken erythrocytes and levan in vivo and sheep erythrocytes in vitro . The cells in these GVH spleens which were responsible for the suppression were sensitive to treatment with anti-0 serum, resistant to 900 rad irradiation in vivo and not retained by anti-immunoglobulin columns . Suppressor activity in vitro was present only in the non-adherent fraction of these GVH cell suspensions . Furthermore, the T-cell fraction, purified by affinity chromatography, suppressed the in vitro response of macrophage-depleted normal F1 cells to DNP-levan . Collectively, these observations imply that suppressor T cells generated by GVH reaction can affect B-cell functions directly without intermediary macrophage participation . Spleen cells from (CBA X C57/BL) F1 mice undergoing GVH reaction induced by C57/BL cells were depleted of their F1 content by treatment with anti-CBA alloantiserum . The suppressive activity of the residual donor component was still expressed against other F1 cells (AKR X C57/BL) which were H-2 compatible with the original host, but not against H-2-incompatible cells (DBA/1 X C57/BL) F1 . However, the latter were suppressed in the presence of (CBA X C57/BL) F1 cells . Thus, interaction of donor T cells with F1 target cells containing those H-2 antigens towards which they are sensitized is mandatory for the subsequent manifestation of immunosuppressive activity . GVH cells suppressed the response of primed F1 cells in double Marbrook chambers when the two populations were separated were by a cell-impermeable membrane, provided the GVH suspension contained F1 cells to which donor T cells were sensitized . This suggests that soluble factors are involved in the mechanism of GVH-induced immunosuppression.

Int J Cancer, 1976 Nov 15, 18(5), 687 - 96
Agglutination reactions of spontaneous canine tumour cells, induced by concanavalin A, demonstrated by an isotopic assay; Betton GR; Quantitative assessment of the agglutination of 51Cr labelled canine cell suspensions to canine kidney cell monolayers has been performed over a range of concanavalin A concentrations . Agglutination was observed with all cell cultures tested, comprising four spontaneous canine melanomas, two canine mammary carcinomas, a benign mammary tumour and a contact-inhibited kidney cell line . The melanomas tested showed strong specific inhibition of concanavalin A agglutination by 10(-2)M alpha-methyl-D-glucopyranoside . Inhibition of agglutination of mammary tumour and kidney cells was weaker and less specific . Agglutination was inhibited at 4degrees C . Reduced agglutination to glutaraldehyde-fixed mono-layers was observed in the case of mammary tumours but was absent when contact-inhibited kidney cells were tested . The specificity of the reaction for transformed cells and the parameters involved are discussed.

J Natl Cancer Inst, 1976 Nov, 57(5), 1157 - 67
An assessment of intratumor phagocytic and surface marker-bearing cells in a series of autochthonous and early passaged chemically induced murine sarcomas; Pross HF et al.; Single cell suspensions from five different 3-methylcholanthrene-induced tumors in CBA mice were examined in the autochthonous host and sequentially for 5-11 passages . They were also examined for Fc receptor-bearing, phagocytic, theta antigen-positive, and surface immunoglobulin-bearing cells . The preparations contained a high proportion of phagocytic and marker-bearing cells both in the original host and during early passage . This proportion was consistent for any particular tumor and passage . Between different tumors, however, the proportions were sufficiently different to allow the tumor to be identified on this basis; this suggested that various chemically induced tumors may be unique in their tumor-host relationship as measured by the type of cells which infiltrate them . With on-going early passage of the tumors, the proportion of marker-bearing cells decreased to a constant level in most instances, mainly because of a reduction in the percentage of phagocytic cells . The tumor with the least macrophages (MBQA, less than 5%) consistently appeared more rapidly and killed the host more rapidly than did the tumor with the most macrophages (MBQD, 15-30%), but was not significantly different in its growth rate . The theta antigen- and Fc receptor-positive cells within these tumors were derived from the animal receiving the tumor inoculum, and thus represented host cell infiltration of the tumor . The results were discussed with reference to fundamental concepts of the immunology of chemically induced tumors and the importance of host cell infiltration within these tumors.

J Natl Cancer Inst, 1976 Nov, 57(5), 995 - 1007
Characterization of mammotrophs separated from the human pituitary gland; Hymer WC et al.; Human pituitary tissues from 27 patients and 7 persons post mortem were dissociated into single cell suspensions . On the average, 23% of the cells were mammotrophs . The concentration of prolactin in these suspensions averaged 3.8 ng/1,000 cells . After cell separation by velocity sedimentation at unit gravity, mammotrophs and other cell types were enriched twofold to threefold . The separated mammotrophs retained structural integrity at light and electron microscopic levels . In eight separation experiments, cells recovered from different gradient regions were assayed for intracellular prolactin levels . In cells from "normal" subjects, 8.5% of the prolactin recovered from the gradient was associated with large mammotrophs, whereas in patients with breast cancer, 28% of the hormone was associated with large mammotrophs . The number of mammotrophs recovered from this gradient region (beyond fraction 6) was doubled in breast cancer (2 expts) . These mammotrophs showed areas of hypertrophied Golgi and endoplasmic reticulum . Culture of the separated cells from 1 patients with diabetes and 2 patients with breast cancer for 21 days showed that mammotrophs in the upper gradient fractions (diabetic) secreted seven times more hormone than those in the lower regions, whereas those mammotrophs from patients with breast cancer that fell to the lower gradient regions secreted 15 times more prolactin than did those in the upper regions . These data suggest that pituitaries of patients with breast cancer contain a small pool (10-20%) of hypertrophied mammotrophs that have the potential for significant secretory activity in vitro.

J Reprod Fertil, 1976 Nov, 48(2), 347 - 53
A highly efficient method for washing mammalian spermatozoa; Harrison RA; A simple method has been developed for washing spermatozoa: the cell suspension is layered over a solution containing Ficoll and, after centrifugation, the original suspending medium remains as an undiluted layer above the Ficoll solution while the spermatozoa form a loose pellet at the bottom . Removal of the supernatant layers is easily and completely accomplished by aspiration . When ram spermatozoa were washed by this method, as much as 99-6% of the original medium could be removed during a single washing cycle, while up to 98% of the cells were recovered . Mechanical damage to the cells was minimal and repeatability was high.

Blut, 1976 Nov, 33(5), 301 - 12
Re-entry of resting leukaemic blood cells into proliferation in human acute leukaemia during diffusion chamber culture; Hoelzer D et al.; From 17 patients with different forms of acute leukaemia, mononuclear blood cells were cultured in diffusion chambers (DC) implanted intraperitoneally into pre-irradiated mice . In 14 patients, growth of blast cells could be observed during the culture period of up to 21 days . To question whether this growth of blast cells was due only to proliferation of the initially proliferating fraction or whether a re-entry of resting leukaemic cells into proliferation was involved, various 3H-thymidine (3H-TdR) labelling studies were carried out . The absolute increase of blast cells in EC showed no correlation with the fraction of leukaemic blast cells in DNA-synthesis in the implanted cell suspension as measured by 3H-TdR labelling in vitro . Furthermore, in 2 patients where the kinetic behaviour of initially labelled leukaemic blast cells was followed during DC culture, the increase in total blast cells could only be attributed to a small extent to proliferation of those cells initially in the cell cycle . Lastly, "in vivo" labelling during the culture period showed that in one case 25% and in another case 60% of the blast cells in DC were proliferating . The conclusion is that, owing to the stimulation of the diffusion chamber milieu and possibly also due to removal of an in vivo inhibition, in most cases of acute leukaemia resting leukaemic blast cells can apparently re-enter the active cell cycle . This has relevance for an understanding of the self-maintenance of the leukaemic cell population and may also be a reason for relapse of leukaemia after the usual cytostatic drug treatment which affects mainly the proliferating leukaemic cells.

Am J Clin Pathol, 1976 Nov, 66(5), 883 - 91
An evaluation of the Haema-Count MK-40 blood counting system; Weisbrot IM et al.; The Haema-Count MK-40, a semiautomated blood counting system, determines hemoglobin, erthrocyte count, leukocyte count, and hematocrit values of blood cell suspensions prepared with a small automatic pipetter-diluter . It is similar to the MK-3, which the authors previously evaluated, but has automatic coincidence correlation and a modified prime and rinse cycle . Its performance was compared with those of standard methods, i.e., the single-channel Coulter Counter and manual cyanmethemoglobin and microhematocrit methods . Precisions for hemoglobin determinations and for leukocyte and erythrocyte counts were equal to those of the reference (comparative) methods . Patients comparisons for those determinations had only small intermethod variability and small clinically insignificant biases . The hematocrit channel was the least precise . With a modified method of calibration, the authors obtained patient comparisons without statistically significant bias from the microhematocrit . Calibration was stable for all channels during the course of the study.

Am J Anat, 1976 Nov, 147(3), 357 - 73
Dissociation of epithelial cells from rabbit trachea and small intestine with demonstration of APUD endocrine cells; Sonstegard KS et al.; In this study the entire epithelial lining of tracheas and a 15-cm segments of small intestine were dissociated into individual cell components after 45-minute incubation with 1% pronase . Light and electron microscopy of isolated cells confirmed good morphologic preservation of various epithelial cell types dissociated from the trachea and small intestinal mucosa . Of particular interest was the recovery and preservation of APUD endocrine cells, which are known to be widely dispersed amongst various non-endocrine epithelial cells in both the trachea and small intestine . The APUD cells were demonstrated in dissociated cell preparations by a formaldehyde-induced fluorescence method, Grimelius' silver nitrate stain, and electron microscopy . The isolated APUD cells retained their characteristic features, e.g., amine-handling properties, argyrophilia and cytoplasmic dense-core vesicles . The cell dissociation method described in this report provides high yields of viable epithelial cells in single cell suspensions which are suitable for further cell separation into homogeneous populations of single kinds of cells, including the APUD endocrine cells . Availability of methods for isolation of tracheal and intestinal APUD cells will facilitate further studies, in vitro, on secretory, metabolic and functional aspects of these cells.

Blood, 1976 Nov, 48(5), 743 - 53
Size distribution, electronic recognition, and counting of human blood monocytes; Loos H et al.; During a study on the separation of human blood monocytes from lymphocytes, a method was developed to recognize and count monocytes by electronic means . Lightscattering (Cytograf, Bio/Physics), and changes in electrical resistance (Channelyzer, Coulter) were used to size mononuclear leukocytes directly in cell suspensions . Both methods revealed a size distribution profile in which two populations of mononuclear leukocytes could be distinguished . The largest cells were virtually eliminated after phagocytosis of iron particles . We confirmed that these cells were monocytes by three different criteria: the intracellular lysozyme activity, the number of phagocytes, and the percentage of cells with kidney-shaped nuclei . The highly significant correlations we found showed that monocytes could be recognized and counted by electronic sizing . For this method, purified mononuclear leukocyte preparations had to be used, since the presence of erythrocytes, platelets, and polymorphonuclear cells interfered . Statistical analysis revealed that electronic sizing permitted discrimination of differences in monocyte content of 4.5%, with a probability of 95% . It was calculated that this sensitivity of electronic monocyte counting was about three times higher than the sensitivity of microscopic methods . Since 100,000 cells can be sized within a few seconds, not only the efficiency of the preparation but also minor changes in the size of monocytes and lymphocytes introduced during the isolation can be followed.

Mikrobiologiia, 1976 Nov-Dec, 45(6), 941 - 5
{Hydrogen production by the cyanobacterium Anabaena variablis in the light}; Gogotov IN et al.; Light of low intensity (less than or equal to 25-10(5) erg-cm(-2)-sec(-1)) stimulates hydrogen production by cell suspensions of Anabaena variabilis in the presence of glucose, pyruvate or formate . The maximum rate of hydrogen production in the presence of these substrates was observed at light intensities of 650, 1400 and 2250 erg-cm(-2)-sec(-1), respectively . The rate of oxygen production by the cells increases while the rate of hydrogen evolution decreases with increase in light intensity (2.5-6.0-10(3) erg-cm(-2)-sec(-1)) . In the presence of DCMU (10(-5)-10(-4) M), hydrogen evolution is not inhibited in the presence of pyruvate or formiate and is inhibited to a less extent in the presence of glucose . According to the results obtained, hydrogen evolution by A . variabilis in the light does not require the action of two photosystems . Inhibition of hydrogen production at significant light intensities is due to the action of oxygen on this process; the rate of oxygen evolution increases with light intensity.

Lab Invest, 1976 Nov, 35(5), 430 - 8
Immunologic and cytochemical cell markers in non-Hodgkin's lymphomas; Davey FR et al.; Lymph nodes were obtained from 28 patients with non-Hodgkin's lymphoma and 24 patients without hematologic malignancy . Cases of undifferentiated lymphoma, diffuse histiocytic lymphoma, diffuse and nodular mixed histiocytic-lymphocytic lymphoma, nodular poorly differentiated lymphocytic lymphoma, and diffuse well differentiated lymphocytic lymphoma were analyzed . Touch preparations were stained for nonspecific esterases, peroxidase, Sudan black B activity and with periodic acid-Schiff and Wright-Giemsa reagents . Mononuclear cell suspension from lymph nodes and, in some cases, peripheral blood were tested for spontaneous rosette formation with sheep erythrocytes and for the presence of surface immunoglobulin . The remainder of the lymph node was examined after staining with hematoxylin and eosin . Analysis of the lymphocyte surface markers indicated that 15 cases of various histologic types of lymphoma were B cell proliferations . However, three out of four cases of diffuse poorly differentiated lymphocytic lymphoma and one of seven cases of diffuse histiocytic lymphoma appeared to represent T cell neoplasia . Lymph nodes from four cases of lymphoma representing diverse histologic types were replaced by neoplastic cells devoid of discernible cell markers . In five cases, the distribution of cell surface markers in the malignant lymph node failed to differ from data obtained in the analysis of non-neoplastic lymph nodes . The study indicates that the histopathologic entities recognized in the currently employed classification of lymphoreticular malignancies are heterogeneous . Alterations in the distribution of cell surface markers in the peripheral blood from five of 12 patients indicated involvement prior to demonstrable morphologic evidence of peripheral blood involvement in four patients and bone marrow infiltration in two patients.

J Virol, 1976 Nov, 20(2), 384 - 90
Infection of resistant avian cells by subgroup B Rous sarcoma virus; Linial M; Chicken fibroblasts derived from the H & N flock, which have been characterized as resistant to subgroup B avian oncornaviruses in focus assays, can be infected in suspension shortly after trypsinization by subgroup B sarcoma and leukosis viruses . Once cells are plated, resistance to infection reappears rapidly . C/BE cell suspensions obtained by treatment with EDTA instead of trypsin are not as sensitive to infection . Late interference established by preinfection with subgroup B leukosis viruses is not overcome by trypsinization . In addition to C/BE H & N chicken cells, C/ABE RPRL line 7 cells can also be infected by subgroup B viruses shortly after trypsinization; however, none of the cell types can be made sensitive to subgroup E infection . These results are discussed in relation to current information on the genetic control of resistance to avian oncornaviruses.

Proc Natl Acad Sci U S A, 1976 Nov, 73(11), 3857 - 61
Subcellular localization of S-adenosyl-L-methionine:tRNA methyltransferases with aminoacyl-tRNA synthetases in human and mouse: normal and leukemic leukocytes; Agris PF et al.; The subcellular distributions of S-adenosyl-L-methionine:tRNA methyltransferases and aminoacyl-tRNA synthetases were investigated with the use of human and mouse normal and leukemic leukocyte cell lines . Differential centrifugation of homogenized cell suspensions produced three pelleted subcellular fractions (nuclear and membrane, microsomal, and postribosomal) and a supernatant fraction . Each fraction was assayed for both methyltransferase activity and synthetase activity . The largest amounts, 40-50%, of total methyltransferase and synthetase activities were localized in either the microsomal or the postribosomal fractions, depending on cell type . In addition, the highest specific activities of these two enzyme systems were found to be present in the microsomal and postribosomal fractions . The psotribosomal fraction from leukemic leukocytes had a methyltransferase specific activity higher than that of the microsomal fraction, while the same two fractions of normal leukocytes had approximately equal activities . Specific activities of aminoacyl-tRNA synthetases were found to be approximately equal for these two fractions, whether they were from normal or leukemic leukocytes . The activity of tRNA methyltransferases and synthetases within the postribosomal fraction of the cytoplasm suggests the existence of high-molecular-weight enzyme complexes for the modification as well as the aminoacylation of tRNA.

Arch Dermatol Res, 1976 Oct 27, 256(3), 255 - 60
Long-term tissue culture of epithelial-like cells from human skin (NCTC strain 2544) . I . Measurement of viscosity; Neufahrt A et al.; Viscosities of cell suspensions of human skin epithelium (NCTC strain 2544) were determined by a Wells-Brookfield rotation viscosimeter . A structure viscosity may be postulated by the form of the viscosity curves at different shear-rates . At a cell number of 0.5 X 10(6) cells/ml a viscosity of 1.094 centipoise (25degrees C, shear-rate 230 s-1) could be found . Since a suspension of single cells may be easily formed mechanically (mopping) the NCTC 2544 cells are useful as investigational model regarding the investigation of membrane characteristics.

Int J Cancer, 1976 Oct 15, 18(4), 432 - 8
Fc receptor-bearing cells as a reliable marker for quantitation of host lymphoreticular infiltration of progressively growing solid tumors; Kerbel RS et al.; Disaggregated cell suspensions made from transplanted solid tumors, either chemically-induced fibrosarcomas, or spontaneous mammary carcinomas, can contain very high numbers of Fc receptor-bearing cells which are of host origin . Because most types of lymphoreticular cells have Fc receptors, and because T cells--most of which are Fc receptor-negative--appear to infiltrate such tumors only to a very limited degree, the possibility that Fc receptor cells could serve as a reliable and simple marker for host lymphoreticular cell infiltration of solid tumors was tested . This was accomplished by comparing the ratios of Fc rosetting cells to serologically detectable host cells in H2d or H2k haplotype tumor cell suspensions grown in (H2d X H2k)f1 hybrid mice, where host cells could be distinguished from tumor cells by treatment with the appropriate anti-H2 serum . Ratios of 0.8 to 1.08 were obtained for four different tumors including the SaD/2 fibrosarcoma, a CBA spontaneous fibrosarcoma, and the T1699 and CaD/2 mammary carcinomas . Analysis of the results showed that enumeration of Fc rosettes was a reliable host cell maker for at least three of the four tumors tested . The mean non-malignant host cell content of the various tumors, as assessed by anti-H2 cytotoxicity tests, ranged from 23% to 41%.

Eur J Immunol, 1976 Oct, 6(10), 757 - 8
The rapid onset of inhibition of antibody-forming cell proliferation upon an increase in density of cellular suspensions cultured in vitro; Gurvich AE et al.; It was shown previously that the development of primary immune response in vitro in the Mishell-Dutton system was strongly inhibited by increased cell densities (Gurvich et al., Immunology 1975 . 28: 271) . In the present work, the rate of onset of this inhibition was studied in C57BL/6 mouse spleen cell suspensions during the phase of exponential increase of antibody-forming cells (AFC) after 3 days' cultivation in vitro with the antigen . It has been shown that the increase in AFC number is very soon inhibited following an increase in the cellular density, the inhibition already being evident within 2 or 4 h . Parallel reduction in incorporation of radioactive precursors in DNA and especially RNA is observed, whereas inhibition of protein synthesis was delayed.

Infect Immun, 1976 Oct, 14(4), 872 - 5
Amplified migration inhibition effect; Philp JR et al.; Upon exposure to specific antigen in tissue culture, sensitive lymphocytes released macrophage migration inhibition factor and other lymphokines into the supernatant culture medium . Migration of peritoneal macrophages from nonsensitive animals was inhibited in the presence of such supernatants . However, with previous techniques it was found that an inhibitory effect was present at only low low titers (less than 10(2)) . It is therfore of great interest that by increasing cellular density, the total number of cells being kept constant, inhibitory activity can be amplified by a factor as great as 10(10) . This amplification was observed only when lymphocytes and macrophages were loosely packed, as by spontaneous sedimentation in a conical test tube . The effect was abolished by dispersing the cell suspension in a flat-bottomed flask or, alternatively, by shaking the test tube so that intimate prolonged intercellular contact was prevented.

Aust J Exp Biol Med Sci, 1976 Oct, 53(5), 381 - 7
Appearance of cytolytic antibodies in sheep lymph following immunisation with tumour cells . Identification of antibody subclasses; Grant CK et al.; Sheep were immunised with mouse P815 tumour cell suspensions and at intervals afterwards lymph was collected draining from the stimulated lymph nodes . The lymph samples were fractionated by column chromatography into IgM, IgG1 and IgG2 antibody fractions; these were then assayed for cytolytic functions on 51Cr labelled target P815 cells . Complement dependent antibodies were assayed using sheep complement; activity was first detected in the IgM fraction 3-4 days after immunisation and in the IgG1 fraction at 5-6 days . No CDA activity was found in fractions of the IgG2 antibody subclass at any time . Leucocyte dependent antibodies were detected only in the IgG fraction, and they appeared simultaneously in both IgG1 and IgG2 subclasses 5-6 days after immunisation.

J Natl Cancer Inst, 1976 Oct, 57(4), 865 - 74
Characteristics of JMV Marek's disease tumor: a nonproductively infected transplantable cell lacking in rescuable Virus; Stephens EA et al.; Cells of the JMV Marek's disease (MD) tumor, originally produced by rapid serial passage of MD lymphoma cells in chickens, were characterized to determine whether they were of host or donor origin and to ascertain certain virus-host cell interrelationships . Differences noted in blood group B surface alloantigens between tumor cells and host lymphocytes indicated a probable nonhost origin (i.e., transplantability) of the tumor . JMV spleen tumors contained predominantly large lymphoblasts bearing MD tumor-associated surface antigen . DNA from JMV tumor cell suspensions hybridized significantly with MD virus cRNA, which indicated that JMV cells contained at least a portion of the MD virus genome . No MD virus was rescued from JMV tumors by techniques suitable for rescue of virus from MD lymphomas . The JMV tumor cells were also devoid of MD virus-specific antigens . These properties differed markedly from those of MD lymphoma cells and make the JMV tumor cell a unique, potentially valuable, tool for further study of oncogenic herpesvirus infection and tumor immunity in the chicken.

Biomedicine, 1976 Sep 30, 25(8), 288 - 90
Leucocyte migration fibrinolysis technique (LMFT): description of a method; Coeugniet E et al.; Human leucocytes can migrate in a gel medium consisting of fibrin, 10% horse serum and tissue culture medium 199 . The cells migrate within the fibrin gel mass . The 24 h . areas of migration depend upon the volume and concentration of the cell suspension applied on the fibrin gel . The amount of cells per mm2 migration culture area is less than half the amount used in the leucocyte migration agarose test . The results are reproducible, the standard variation of the migration areas is below 10% . The method is potentially useful for several purposes such as for measuring fibrinolytic and migratory activity of granulocytes, monocytes and lymphocytes and modification of these functions by lymphokines.

Int J Cancer, 1976 Sep 15, 18(3), 331 - 8
Inflammatory cells in solid murine neoplasms . II . Cell types found throughout the course of Moloney sarcoma regression or progression; Russell SW et al.; Regressing and progressing Moloney sarcomas, induced in BALB/c mice by the injection of cultured sarcoma cells (MSC)1, were sampled for histologic analysis and then disaggregated using mixtures of trypsin, collagenase and DNAse or collagenase and DNAse alone . The types of inflammatory cells (IC) found in resultant cell suspensions were determined 6, 11, 14 and 18 days post inoculation . Inflammatory infiltrates were composed almost exclusively of three cell types; neutrophils, T lymphocytes and macrophages . The extent to which each was found in tumors was related to the time post inoculation . Neutrophils were part of an early acute inflammatory response seen in both developing regressing and progressing sarcomas . The onset of regression was associated histologically with the appearance within tumors of a mononuclear inflammatory infiltrate . T lymphocytes and macrophages were the principal constituents . A higher percentage of T lymphocytes was recovered at all sampling times from regressing, compared to progressing, sarcomas . During development of the mononuclear inflammatory infiltrate there were relatively more large T cells in regressing, than in progressing tumors, and the percentage of macrophages was higher . Thereafter, the proportion of macrophages in the recovered cell population was approximately the same for both types of tumor . Such equality was more apparent than real, however, since IC were restricted to the peripheries of progressing sarcomas after the acute inflammatory phase, but continued to be found throughout regressing neoplasms . The effective ratio of macrophages and T lymphocytes to tumor cells therefore was much lower in progressing sarcomas than was suggested by percentage figures . The data presented support the concept that T lymphocytes are instrumental in causing the regression of Moloney sarcomas, possibly through interactions with macrophages.

Int J Cancer, 1976 Sep 15, 18(3), 322 - 30
Inflammatory cells in solid murine neoplasms . I . Tumor disaggregation and identification of constituent inflammatory cells; Russell SW et al.; Mechanical and enzymatic methods of disaggregating tumors were studied with the goals of (1) minimizing cell losses while (2) maintaining functional and surface membrane markers needed to objectively identify inflammatory cells (IC)1 in resultant suspensions . Application of the principles and methods described makes accurate estimation of the percentage of each IC type present in neoplasms possible for the first time . Compared to purely mechanical means of disaggregating tumors, all enzyme mixtures tested markedly increased yields of viable cells/g neoplasm . Best results were obtained with a combination of collagenase and a protease of broader substrate range (alpha chymotrypsin, papain, pronase or trypsin) . The combination of enzymes that gave the highest yields with the least effect on inflammatory cell markers was trypsin, collagenase and DNAse (TCD) . Because mechanical injury appeared to be the greatest single cause of cell loss (the enzymes themselves had little direct effect), potential sources were identified and either eliminated or minimized . With TCD, depending on the tumor system, cell recovery (measured as DNA recovered in cell suspensions) was as high as 50% and yields were as much as 6.9 X 10(8) viable cells/g tumor . Complete disaggregation was not required to obtain representative IC populations from tumor fragments . Neutrophils, eosinophils and mast cells from disaggregated neoplasms were counted in Giemsa stained cytocentrifuge preparations based on their unique morphologic appearances . Macrophages were identified by their capacity to phagocytose zymosan, a function which proved highly resistant to the effect of enzymes . Flourescent microscopic identification of brain associated thymus antigen (BATA) allowed quantification of T lymphocytes, since this marker was virtually unchanged by enzyme exposure . Surface immunoglobulin (Ig) was stripped from B lymphocytes most rapidly by pronase and chymotrypsin, slowly by trypsin and papain, and not at all by collagenase . Ig positive cells therefore could be quantified in suspensions generated by collagenase or very short (20 min) exposure of fragments to trypsin.

Cancer Res, 1976 Sep, 36(9 PT 2), 3471 - 5
Detection of T-cell lymphoma-associated antigens on cord blood lymphocytes and phytohemagglutinin-stimulated blasts; Kaplan J et al.; Absorption studies demonstrate that T-cell lymphoma-associated antigens detected by rabbit antisera to human T-lymphoblast cell lines are present in suspensions of cord blood lymphocytes and phytohemagglutinin-stimulated adult blood lymphocytes in amounts similar to those found in T-cell lymphoma tumor cell suspensions . Smaller amounts of antigen activity are found in suspensions of tonsil cells, thymocytes, and unstimulated adult blood lymphocytes . Little or no antigen activity is found in suspensions of lymphoblasts from patients with other types of leukemia or from B-cell lines . T-cell depletion removes antigen activity from suspensions of normal lymphocytes . These findings suggest that T-cell lymphoma-associated antigens may be fetal antigens expressed by activated T-cells.

Allergol Immunopathol (Madr), 1976 Sep-Oct, 4(5), 325 - 32
Localization of T and B lymphocytes in human adenoid, tonsil, appendix and Peyer's patches; Mello JF et al.; T and B lymphocytes were detected in human adenoid, tonsil, appendix and Peyer's patches by adherence to sheep erythrocytes (E) and human erythrocytes sensitized with antibody and complement (HEAC) . The percentages of T lymphocytes in adenoid and tonsil cell suspensions averaged 30.9 +/- 3.4 (S.D.) and 35.8 +/- 6.4 (S.D.) . The percentages of B lymphocytes in the same tissues were 42.5 +/- 11.3 (S.D.) and 40.1 +/- 34 (S.D.) respectively . In adenoid and tonsil tissue sections, B lymphocytes were found in the follicles and T lymphocytes were detected around the follicular areas . The predominant cell population in Peyer's patches and appendix sections was constituted by B lymphocytes.

Blut, 1976 Sep, 33(3), 171 - 80
Erythroid colony formation (CFUe) in fetal liver and adult bone marrow and spleen from the mouse; Rich IN et al.; The methyl cellulose modification of the CFUe technique has been applied to 14 day fetal liver and adult bone marrow and spleen from CBA/CA mice . Optimized doses of fetal calf serum, alpha-thioglycerol, erythropoietin and cell suspensions have been obtained from dose response curves in order to standardize the technique . The slopes of the erythropoietin and cell dose response curves indicate a greater sensitivity by fetal liver to the hormone than bone marrow or spleen . The proportion of cells in the DNA synthesis phase of the cell cycle, as measured by the CFUe technique, has been estimated by administering hydroxyurea . Two hours after the drug was injected, 89% of fetal liver cells, 71% of bone marrow cells and 81% of spleen cells were found to be in the S-phase.

Immunology, 1976 Sep, 31(3), 443 - 53
Casein-induced experimental amyloidosis . VI . A pathogenic role for b cells in the murine model; Scheinberg MA et al.; The relationship between cellular (B-cell) responses and the development of casein-induced amyloidosis was explored . The main findings are: (1) B-cell abnormalities are more pronounced in amyloid susceptible CBA/J than in amyloid resistant A/J mice; these include increased mitogen responses to SIII, PI:C and DXS, and enhanced primary immune responses to T-independent antigens; (2) CBA/J amyloid spleen cell suspensions appear to be enriched with antibody dependent killer cells and precursors of antibody-forming cells; these abnormalities are not seen in casein treated A/J mice . This hitherto unrecognized proliferation of immunoblasts in casein-treated CBA/J animals raises the possibility that B cell-macrophage interaction may play an important role in the pathogenesis of amyloid disease.

Tumori, 1976 Sep-Oct, 62(5), 503 - 15
Electron microscopic observations on T and B lymphocytes from spleens of syngeneic radiation chimaeras; Rebessi S et al.; The ultrastructure of T and B lymphocytes has been examined in long-term syngeneic chimaeras and age-control mice . Spleen cell suspensions from these mice were passed through glass wool columns to obtain pure lymphocyte populations . These cells were then separated into T and B lymphocytes by nylon wool columns, and their purity was tested by cytotoxicity assays with anti-phi serum . Electron microscopic observations on such separated T and B lymphocytes did not reveal morphological differences except when the cells were fully differentiated, either as mature (T2) cells or plasmacells . In particular, T2 cells showed a very high cytoplasmic density, attributable to the presence of a larger number of microfilaments with respect to immature (T1) cells . In long-term chimaeras a significantly larger number of T2 cells was found as compared to age-control mice, and this morphological observation is correlated with the differences in immune reactivity and leukemia incidence previously described in these mice.

Can J Microbiol, 1976 Sep, 22(9), 1293 - 9
The respiratory metabolism of Mycobacterium lepraemurium; Kato L et al.; The respiratory metabolism of Mycobacterium lepraemurium isolated from Sprague-Dawley rats lepromata using several substrates was investigated . None of the intermediates of the glycolysis cycle as well as of the tricarboxylic acid cycle except succinate was oxidized by purified whole suspensions of M . lepraemurium . Likewise, many sulfur compounds such as cystine, thiourea, thioacetate, thiodiglycol, mercaptoact and some sulfhydryl compounds, e.g., cysteine, dithioerythritol, dithiorthritol, and penicillamine were readily oxidized by murine bacillary suspensions, whereas thioglycolate, thioglucose, and reduced glutathione were oxidized at a slow rate . Succinate was not or was very poorly oxidized by normal cells probably because of impermeability of the cell wall but the addition of succinate to the cell suspensions frozen for 1 min at -40 degrees C considerably enhanced oxygen uptake over the endogenous value . The oxidation of succinate was unaffected by inhibitors rotenone, atabrine, and amytal but was markedly inhibited by thenoyltrifluoroacetone, antimycin A, 2-N-heptyl-4-hydroxyquinoline-N-oxide, and cyanide . The thiol-binding agents, p-hydroxymercuribenzoate and N-ethylmaleimide were also effective inhibitors of succinate oxidation but the process was not affected by uncouplers dinitrophenol, dibromophenol, pentachlorophenol, and carbonyl-cyanide-m-chlorophenylhydrazone . The results indicated that succinate oxidation by M . lepraemurium was mediated by oxidative enzymes involving an electron transport chain with oxygen as the terminal electron acceptor.

J Bacteriol, 1976 Sep, 127(3), 1188 - 96
Energy cost of galactoside transport to Escherichia coli; Purdy DR et al.; Energy reserves of Escherichia coli can be depleted by our previously reported procedure to a level such that even the "downhill" transport of o-nitrophenyl-beta-D-galactopyranoside (ONPG) is completely dependent upon the exogenous energy supply . The ONPG concentration is high externally to the cells and is low intracellular because of the action of cytoplasmic beta-galactosidase . In the present work, depleted cell suspensions have been infused at low, steady rates with glucose and other energy sources while measurements of transport were being made . Comparing the rate of ONPG transport with the rate of introduction of glucose under conditions where the chosen glucose infusion rate limits transport, we find that 89 molecules of ONPG are transported per molecule of fully oxidized glucose . This transport yield is constant over a 6.5-fold range in rate of glucose addition . This constancy over a range of infusion rates implies that transport is the major cellular function under these special conditions . The yield value if 89 is in the agreement with the predicitions of 76 from Mitchell's chemiosmotic theory and constitutes an independent proff of its validity, since all the other proposed mechanisms of engery coupling predict much smaller yields . The lag from the start of glucose infusion into the reaction cuvette, to the extrapolated time at which a steady rate of transport and concomitant hydrolysis are achieved, is short (approximately 1 min) . Similarly, the time after the infusion is stopped until the rate of transport returns to the background rate is also short . The latter implies that the energy metabolism is directed almost entirely to transport and/or other ongoing cellular processes and not to repair or renewal of an energy-independent, facilitated diffusion system.

J Endocrinol, 1976 Sep, 70(3), 345 - 59
Purification and characterization of Leydig cells from rat testes; Janszen FH et al.; An LH-responsive Leydig cell preparation (containing 6+/-2% Leydig cells) was obtained by collagenase treatment of rat testis . Centrifugation of this cell preparation through a 13% Ficoll solution for 10 min at 1500 g resulted in a four times purification of the Leydig cells, with a concomitant increases in steroidogenic activity . Addition of 0-2% albumin to the 13% Ficoll solution, adjusted to 280 mosmol/l, resulted in a further twofold purification of the Leydig cells paralleled by a twofold increase in steroidogenic activity . Centrifugation of these Ficoll-albumin-purified Leydig cells through a 6% dextran solution for 2 min at 100 g resulted in a further 1-7 times purification of the Leydig cells . A combination of the two centrifugation steps resulted in a 12-5 times purification of Leydig cells compared with the original crude cell suspension, while an increase in steroidogenic activity of 22-5 times was obtained . This final cell preparation contained 59 +/- 17% Leydig cells (mean +/- S.D., n = 6) . The recovery of Leydig cells was 29% . Collagenase treatment of testes deficient in spermatogenesis resulted in a cell preparation with the same steroidogenic activity as Ficoll-purified cells from normal testes . Centrifugation of these cells through a 13% Ficoll solution gave only a limited increase in the steroidogenic activity . Isopycnic centrifugation of the crude cell preparation on a discontinous Ficoll metrizoate gradient resulted in two discrete peaks of Leydig cells, one peak at a density of 1-039-1-055 g/ml and one at a density of 1-068-1-088 g/ml . Both types of cells produced testosterone . In the presence of LH, cyclic AMP production in both types of Leydig cells increased, but testosterone production was only increased by LH in the "denser" Leydig cells and not in the "light" Leydig cells . No difference in sensitivity to LH could be observed between the Leydig cell preparations of different purity . Using a 60 min pre-incubation period the highest testosterone response was obtained with 100-1000 ng LH/ml . The same maximum testosterone response was obtained with 10-100 ng LH/ml when the pre-incubation period was omitted.

Cancer Res, 1976 Sep, 36(9 pt.1), 3171 - 7
Loss or persistence of the differentiated state of simian virus 40-induced hamster tumor cells before and after serial passage in culture; Diamandopoulos GT et al.; The transformed cells that arise from among the hamster epithelial and mesenchymal cells exposed to SV40 in vitro are, as a rule, fibroblastoid and pleomorphic rather than epithelioid . Moreover, the neoplasms that these transformed cells induce in the allogeneic host are spindle cell sarcomas and pleomorphic sarcomas rather than carcinomas . Since this phenomenon may result from cellular dedifferentiation in culture, to the extent that the anaplastic morphology and lack of specialized function can no longer suggest the cell or origin, we investigated the fate of the differentiated state of cells of three types of SV40-induced hamster tumors before and after serial passage in vitro . The tumors evaluated were three reticulum cell sarcomas, three osteogenic sarcomas, and two lymphosarcomas of B-cell origin . Our data demonstrate that reticulum cell sarcoma cells lose their morphological differentiation soon after the original tumors are dissociated into cell suspensions but preserve their phagocytic activity throughout their in vitro passage . Osteogenic sarcoma cells lose their differentiated phenotype and their capacity to form osteoid during but not before their serial passage in culture . Lymphosarcoma cells preserve their lymphoid morphology and their ability to produce immunoglobulin even after many in vitro passages . These results indicate that, in many types of SV40-induced tumors, neoplastic cell dedifferentiation, following serial passage in culture, is responsible to a great extent for the emergence of new cell phenotypes lacking in morphological and functional features characteristic of the cells originally transformed by SV40.

Cancer Res, 1976 Sep, 36(9 pt.1), 3113 - 8
Biosynthesis of albumin via a precursor protein in Morris hepatoma 5123tc; Edwards K et al.; The mechanism of albumin biosynthesis was studied in Morris hepatoma 5123tc in vivo and in hepatoma cell suspensions obtained by solubilizing the intercellular matrix with collagenase and hyaluronidase . In the in vivo experiments, L-{-14C}leucine was injected i.v . into rats bearing hepatomas in the muscles of both hind legs . After 14 min, tumors were removed and homogenized . A protein fraction quantitatively precipitable with antialbumin was isolated from the homogenate by acetone fractionation and precipitation with antiserum against serum albumin . This protein fraction was not homogeneous . With the use of 3 consecutive chromatographies on diethylaminoethyl cellulose, a very highly radioactive albumin-like protein could be separated from a large amount of only slightly radioactive albumin . In hepatoma cell suspensions incubated with L-{1-14C}leucine followed by a chase with excess nonradioactive L-leucine, radioactivity was incorporated first into the albumin-like protein and transferred thereafter into albumin, suggesting that albumin was synthesized via the albuminlike protein as precursor . In vivo, 1.8% of newly synthesized hepatoma protein was albumin or its precursor, compared with 1.2% in cell suspensions.

Proc Soc Exp Biol Med, 1976 Sep, 152(4), 631 - 4
Role of converting enzyme in the cardiovascular and adrenal cortical responses to (des-Asp1)-angiotensin I; Larner A et al.; (Des-Asp1)-angiotensin I, angiotensin II and III were evaluated for pressor activities in conscious nephrectomized rats and for steroidogenic actions in rat adrenal zona glomerulosa . The pressor effect of this angiotensin nonapeptide was similar to that found with mole-equivalent doses of angiotensin III (one-third as active as angiotensin II) and was significantly attenuated by pretreatment with the 0 . jararaca nonapeptide converting enzyme inhibitor . Hence, (des-Asp1)-angiotensin I is a substrate for converting enzyme in vivo, and the rapid conversion indicates that an alternate pathway for the formation of angiotensin III could exist . (Des-Asp1)-angiotensin I possessed only 0.1% of the activity of angiotensin III as a steroidogenic agent in cell suspensions of rat adrenal zona glomerulosa . Angiotensin I was a weak steroidogenic agent in vitro (1%) and was not blocked by an inhibitor of converting enzyme . Adrenal cells dispersed from the outer zone of the cortex would appear to be devoid of significant converting enzyme activity.

Am J Pathol, 1976 Sep, 84(3), 469 - 78
An in vitro model of pancreatic carcinoma . Morphology and in vivo growth; Parsa I et al.; Pancreas rudiments from 13-day rat embryos were cultured in the presence of dimethylnitrosamine (DMN) for up to 10 weeks . Pancreas morphogenesis and differentiation occurred during the first week of culture . Acinar cell degeneration and necrosis began on the fifth day of culture and resulted in almost complete loss of acinar cells, islet cells, and fibroblasts by the end of the third week . This was associated with proliferation of cells without zymogen granules (centroacinar, ductal, or undifferentiated?) . Theses cells formed glandular structures which extended to the surface of the explant . By the end of the fourth week, explants resembled ductal hyperplasia with foci of carcinoma in situ . The distribution pattern of neoplasia in 343 explants examined after 10 weeks of DMN treatment was as follows: 79% resembled ductal cell carcinoma; 9%, ductal hyperplasia; and 3%, acinar cell carcinoma . Nude mice injected with cell suspensions prepared from 10-week-old culture developed subcutaneous nodules . These nodules resembled duct cell carcinoma with desmoplastic reaction.

Endocrinology, 1976 Sep, 99(3), 758 - 64
Induction of follicle-stimulating hormone (FSH) receptors in rat ovaries by estrogen priming; Louvet JP et al.; Estrogen pretreatment of hypophysectomized immature rats stimulated granulosa cell proliferation and enhanced FSH binding to the ovary in vivo . The present studies were undertaken to ascertain whether estrogen pretreatment altered the number of specific FSH receptor sites per ovarian cell, resulting in increased FSH binding . Cell suspensions were prepared from the ovaries of groups of rats pretreated with graded doses of 17beta-estradiol . The isolated cells contained specific FSH receptors with high affinity for FSH . The results of these studies clearly showed that the number of specific FSH receptors per ovarian cell was unaffected by pretreatment with graded doses of 17beta-estradiol or with diethylstilbestrol . The enhanced in vivo FSH binding was solely the result of estrogen-induced proliferation of granulosa cells with a fixed number of specific FSH receptors per cell.

Ann Immunol (Paris), 1976 Sep-Oct, 127(5), 717 - 31
{The spleen in "nude" mice: an immunological and immunocytochemical study (author's transl)}; Viac J et al.; An immunological and immunocytochemical study to compare spleen cells of Nude (C57B1) and Swiss mice is reported . The percentage of surface immunoglobulins bearing lymphocytes is identical in both strains of animal (40%) . An activated C3 receptor is present in the majority of these cells and has been demonstrated within the germinal centers in both cell suspensions and frozen tissue sections . The population of Fc receptor bearing cells is more heterogenous, but the percentage of these is nearly identical in both Swiss and Nude mice . T-cell specificity is identified with an anti-thymocyte and an antibrain antiserum using an indirect immunoperoxidase method . The percentage of cells detected with the anti-thymocyte antiserum is very low in the spleen of Nude mice (5%) compared to that in the Swiss mice (42%) . In the Nude mice, the anti-brain antiserum detects up to 30% of the spleen cells which may be considered as precursors and, so far, these 30% of cells in the Nude mice are considered as "null" cells, compared to only 20% in normal mice . The localization of the various immunocompetent cells within the spleen tissue is determined by immunofluorescence, immunoenzymology and the EAC rosette test . This study leads to the conclusion that in the periarteriolar areas of the spleen of the Nude mice, immune cells are sparse but that thymo-independent cells are located in the same region in both species of mice.

Rev Esp Fisiol, 1976 Sep, 32(3), 187 - 92
Measurement of glycolytic rates in cell suspensions using a recording pH meter; Lopez-Alarcon L et al.; A method for measuring continuously glycolytic rates in cell suspensions, using a recording pH meter, is described . Under the described conditions the method is very exact, sensitive and reproducible . The method can be applied to different cells and different conditions of assay calibrating in each case the pH range, cell concentration range and the ratio of delta protons to delta lactic acid.

Eur J Biochem, 1976 Aug 16, 67(2), 527 - 41
Light-induced enzyme synthesis in cell suspension cultures of Petroselinum hortense . Demonstration in a heterologous cell-free system of rapid changes in the rate of phenylalanine ammonia-lyase synthesis; Schroder J et al.; The conditions for protein synthesis in vitro with polyribosomes from cell suspension cultures of parsel (Petroselinum hortense) and a wheat-germ extract were investigated . Two different criteria were used as estimated of the translational activity: (a) the total rate of incorporation of {35S}methionine into acid-insoluble material; (b) the ratio of large (molecular weight greater than 25000) to small (molecular weight less than 25000) peptide products . Depending on which of the criteria was employed, the pH optimum and the optimal concentrations for Tris=acetate, magnesium acetate, KCL, methionine and the wheat-germ extract differed considerably . The translational activity of the polyribosomes (both criteria) was effciently protected by 0.1 M Mg2+ against degradation during the isolation procedure . The rate of synthesis of phenylalanine ammonia-lyase in vitro with the polyribosomes was determined by measuring the incorporation rate of L-{35S}methionine into protein which was precipitable by a rabbit antiserum prepared for the purified enzyme . The immunoprecipitate was analyzed by disc gel electrophoresis in the presence of dodecylsulfate and was shown to contain small amounts of the complete enzyme subunits and relatively large amounts of shorter peptides which were also characteristic for the enzyme . The time course of light-induced changes in the rate of phenylalanine ammonia-lyase synthesis in vitro were investigated during a period of 15 h under two different conditions of induction: the cell cultures were irradiated with ultraviolet light eith (A) continuously or (B) for 2.5 h and then returned to darkness . Although the highest rate of enzyme synthesis was observed somewhat later inexperiment A than in experiment B, the periods of time during which the rate of synthesis increased rapidly were limited in both cases to only a few hours . The results obtained in vitro were identical within the limits of the experimental error with theoretical calculations of the changes in the rate constant of phenylalanine ammonia-lyase synthesis in vivo . These changes were calculated from the corresponding curves for the changes in the enzyme activity under the conditions of induction . The results are in agreement with previous observations suggesting that the induction of phenylalanine ammonia-lyase by light in the parsley cells was a short-term effect whose efficiency was greatly reduced within the 15 h of experimentation, even under continuous irradiation.

Int J Cancer, 1976 Aug 15, 18(2), 189 - 96
Interactions of murine leukemia virus (MuLV) with isolated lymphocytes . II . Infections of B and T cells with Friend virus complex indiffusion chambers and in vitro: effect of polyclonal mitogens; Cerny J et al.; The infection of isolated B and T cells by a murine leukemia virus (Friend) MuLV-F) was studied both in vitro and in vivo with an implanted diffusion chamber system . Lymphocytes were obtained from pools of normal spleen cells by filtration of the cell suspension through a nylon-wool column . The purity for both Ig positive and theta-positive cells varied between 85% and 90% in the B-cell and T-cell fractions; both lymphocyte fractions responded very well to stimulation with their respective specific polyclonal mitogens, bacterial lipopolysaccharide (LPS) and concanavalin A (Con A) . Lymphocytes were infected by incubating pelleted cells in 2-6 x 10(4) FFU MuLV for 1 h at 4 degrees C and were then cultured for 5-10 days . Cells releasing infectious MuLV were enumerated as infectious centers (IC) . IC were really detectable in the cultures of infected B-cells but none were found in the T-cell cultures . Addition of LPS to the culture medium increased the number of IC in B-cell fractions up to 1,000-fold . Furthermore, in T-cell cultures with LPS, IC also appeared in number which approximately correlated with the contaminating Ig+ cells of the T-cell fraction . In contrast, Con A had no consistent effect on the infection of either B or T cells . In the absence of MuLV-F, mitogenic stimulation alone did not elicit any endogenous IC . In subsequent experiments, purified lymphocytes were infected in diffusion chambers in vivo . The number of IC in infected B cells increased 1,000-fold as compared to infection in tissue culture . The peak of infection at 10 days was followed by a slight decline . Infected cells were also found in diffusion chambers containing T-cell fractions; these IC had very similar kinetics to those in B-cell-containing chambers, but their number was 10 times lower, suggesting that the infected cells were B cells, which comprised about 10% of the T-cell fraction . The virus-related antigens were detectable by immunofluorescence on the membrane of cells recovered from B-cell-bearing chambers but not on cells from T-cell-bearing chambers.

Int J Cancer, 1976 Aug 15, 18(2), 197 - 204
Interactions of murine leukemia virus (MuLV) with isolated lymphocytes . III . Alterations of splenic B and T cells in Friend virus-infected mice; Cerny J et al.; Lymphoid tissues of mice infected with murine leukemia virus (Friend) (MuLV-F) were examined for the presence of cellular markers of MuLV-F infection . The Friend virus-associated cell membrane antigen (FVMA) and the virus group-specific antigen (GSA) were detectable on cells from the spleen and, to a lesser degree, on cells from the bone-marrow . In contrast, neither FVMA nor GSA was found in cells from the thymus . Alterations in the B-cell and T-cell spleen populations of MuLV-F-infected mice were then studied . The proportion of Ig-positive cells declined from the initial 45% (in non-infected controls) to about 10% after 2 weeks of infection . A similar decline of theta-positive cells was noted . However, complement-bearing cells (EAC rosettes) declined even more rapidly and became undetectable in the second week after infection . The treatment of spleen cells from MuLV-F-infected mice with anti-FVMA serum plus complement in vitro reduced the number of detectable Ig-positive cells, specifically, whereas the number of theta-positive cells remained unchanged . Furthermore, B and T cells from spleens of infected mice were separated on an affinity column with anti-Ig antibody-coated beads . The initial cell suspension contained about 45% FVMA-positive cells, about 40% Ig-positive cells and about 40% theta-positive cells . Ig+ cells were retained on the column . The theta-positive cell fraction was collected in the eluate and contained very few FVMA-positive cells with some "null" cells . Most of the FVMA-positive cells were retained on the column, which strongly suggested that they were B cells . These results confirm the previous experiments which showed the selective infections of purified splenic B cells by MuLV-F in cultures.

Biochim Biophys Acta, 1976 Aug 13, 440(2), 429 - 47
Membranes of Rhodopseudomonas sphaeroides . IV . Assembly of chromatophores in low-aeration cell suspensions; Niederman RA et al.; Chromatophore membrane formation was induced in low-aeration suspensions of Rhodopseudomonas sphaeroides and highly purified chromatophore preparations were isolated at various intervals between 4 and 18 h . The levels of several functional components associated with the isolated strucures were investigated . B-875, the light-harvesting bacteriochlorophyll complex associated with the reaction center, was preferentially inserted into the chromatophore membrane during the early stages of induction, and thereafter its levels reached a steady state; b- and c-type cytochromes were also maintained at essentially constant levels . In contrast, the levels of B-850, the accessory light-harvesting bacteriochlorophyll, together with its associated protein, continued to increase throughout the induction process . Increases in the levels of the major carotenoid component followed a similar course . These findings are consistent with a stepwise assembly mechanism for associated bacteriochlorophyll and protein components and suggest that separate regulatory mechanisms control the levels of functionally essential and accessory components within the membrane.

Clin Exp Immunol, 1976 Aug, 25(2), 319 - 27
Rosette-formation with mouse erythrocytes . II . A marker for human B and non-T lymphocytes; Gupta S et al.; Peripheral blood lymphocytes from healthy control subjects were studied for spontaneous rosette-formation with mouse erythrocytes . The mean percentage of mouse erythrocyte rosette-forming cells (MRFC) in sixty-three subjects was 7.4X3.5; after neuraminidase treatment olymphocytes the mean percentage of mouse erythrocyte rosette-forming cells(NMRFC) was 17.2X5.6 . Thymus cell suspensions made only occasional rosettes with mouse erythrocytes . There was no effect of neuraminidase treatment of thymocytes on mouse erythrocyte rosette-formation . Double labelling experiments with other cell surface markers confirmed this binding of mouse erythrocytes to be a B-cell characteristic . Monocytes and granulocytes do not bind mouse erythrocytes . It appears that there is a distinct receptor for the binding of mouse erythrocytes on the surface of lymphocytes carrying surface immunoglobulins; neuraminidase treatment of lymphocytes permits this binding to occur also on virtually all the non-T cells B cells plus the third population cells).

J Natl Cancer Inst, 1976 Aug, 57(2), 345 - 8
Role of donor immunocompetent cells in allograft rejection; Jacobs BB et al.; Allotransplantable lines of the BALB/c (H-2d) Leydig cell tumor C4092 were established in DBA/1 (H-2q) mice after maintenance in organ culture . These modified tumors had reduced immunogenicity but were recognized and rejected by previously sensitized DBA/1 mice . The addition of 3.4 X 10(3)-1 X 10(5) peritoneal exudate cells (PEC) from untreated BALB/c mice to cell suspensions of the modified tumor did not restore Immunogenicity when the cell mixture was Inoculated sc Into DBA/1 recipients . However, when equivalent numbers of PEC or spleen cells were inoculated iv into animals receiving the tumor cell suspension sc, the acceptance of the tumors was significantly reduced or prevented . This indicated that the BALB/c lymphoid cells inoculated iv stimulated the immune system of the host, which in turn recognized the tumor cell inoculum . The lack of effect of the BALB/c lymphoid cells when admixed with the tumor did not support the assumption that the loss of passenger lymphoid cells was responsible for the allotransplantability of grafts after organ culture explantation . Additional evidence was presented that supports our view that the reduced immunogenicity was associated with a phenotypic modification of the tumor cells per se.

Tsitologiia, 1976 Aug, 18(8), 1003 - 7
{Effect of uncoupling agents and benz (a) pyrene metabolites on respiration in L cells and normal mouse embryonal fibroblasts}; Riabykh TP et al.; A method is proposed for a polarografic study of the respiration of cell suspensions obtained from monolayer cultures of L-cells and from normal embryonic fibroblasts of mice (C3HA line) . 6-hydroxybenzo(a)pyrene (6-OHBP) . The metabolite of the carcinogenic hydrocarbon benzo(a)pyrene, was shown to be a strong uncoupler of of oxidation and phosphorylation of cell suspensions . Its effect was influenced by the presence of calf serum in the incubation media . Possible relationships between the toxic effect of 6-OHBP on monolayer cultures of normal and tumor cells, and its effect on cell energetics are discussed.

Beitr Pathol, 1976 Aug, 158(3), 255 - 86
{Sarcoma 180: growth and regression . Comparative investigations using flow-through and scanning cytophotometers as well as histological, cytological and autoradiographic techniques (author's transl)}; Stecher G et al.; Material and methods: The growth and the regression of the experimental tumor S 180 was investiaged by volume measurements and by cytophotometric studies on 50 mice in each of a pilot and in the present main experiment . In addition, histological, cytological and cytokinetic examinations were performed . Results and discussion: Beginning on day 18, a spontaneous regression of the tumor was found in 20% and 38% of the animals, respectively . DNA-measurements were performed with a scanning-microspectrophotometer on tumor tissue imprints and tumor cell suspensions and were also carried out with a flow-through cytophotometer ICP on suspensions . DNA-histograms were plotted on days 4, 7, 12, 18, 20, 22, 26 and 29 after the transplantation . These revealed a constant position of the maxima at 2C for normal cells and at 4C and 8C for the tumor cells . In particular, by measuring a large total number of 4,968,000 nuclei with the ICP, distinct changes were found in the proportion of the single nuclei classes during growth and spontaneous regression . This technique also enables a quantitative measurement to be made of the DNA of cell debris from necrosis . With growing tumos, the proportion of the tumor cells increased to a maximum of 65% on day 18 and decreased to 37% on day 29 . The DNA of cell debris grew from 8% to 47% . The proportion of normal cells was only 10% to 15% in the final phases . In tumors with a spontaneous regression the proportion of the tumor cell nuclei was 20% on day 18 and 11% on day 29 . The proportion of the DNA of cell debris was again about 45% . The proportion of normal nuclei was greatly increased to 45% . Histological and cytological evidence together with measurements of the areas of nuclei and incorporation of 3H-TdR confirmed that the normal cells, the number of which increased during spontaneous regression were cells of a fibrovascular granulation tissue . While the rate of the DNA-synthesis of growing tumors continously decreased with age there was also a rapid decrease of the labelling index of spontaneously regressing tumors between days 12 and 18 . In the final phase only the nuclei of the granulation tissue were labelled.

Transplantation, 1976 Aug, 22(2), 101 - 7
Influence of separation techniques on the distribution and function of lymphocyte subpopulations . A comparison of three techniques; Mookerjee BK; The effect, if any, of three different lymphocyte separation techniques on the composition and functional characteristics of the purified cell suspensions has been studied . Each separation technique was shown to yield a cell population with highly specific and reproducible characteristics . The Ficoll-Hypaque technique led to good lymphocyte yields but low yields of sheep erythrocyte-rosetting (E-rosetting) T cells, and the separated cell population responded least well to phytohemagglutinin . The glass sand filtration technique led to lowest overall yield of small lymphocytes and of EAC-rosetting cells . There was significantly lower total yield of E-rosetting T cell as well, but the separated lymphocyte suspension had excellent purity, had relatively high percentage of E-rosetting T cells, and they responded extremely well to phytohemagglutinin (PHA) and pokeweed mitogen (PWM) . The Technicon separation involving magneticremoval of phagocytic cells by exposure to iron particles consistently led to large yields of small lymphocytes with good purity, the largest total harvests of E-rosetting T cells, as well as EAC-rosetting cells while the separated population had the highest percentage of E-rosetting cells and responded very well to PHA and PWM . These results show that lymphocyte losses during purification are not nonspecific and that the choice of the separation technique profoundly affects the characteristics of the purified lymphocyte population obtainable.

Am J Pathol, 1976 Aug, 84(2), 259 - 82
The repopulation of lymph nodes of dogs after 1200 R whole-body x-irradiation and intravenous administration of mononuclear blood leukocytes; Nelson B et al.; Fresh and cryopreserved autologous or allogeneic mononuclear blood cells (MBCs) intravenously injected in 1200 R total-body x-irradiated dogs repopulated lymph nodes within 10 days after tranfusion . Several parameters of the lymphopoietic regeneration were correlated with the number of cells transfused and with the number of colony-forming units contained in the cell suspension when they were cultured in agar (CFUc) . Values within the normal or close to normal range were reached in the mesenteric nodes of most of the animals transfused with 10 X 10(9) MBC or more . These values were obtained when 5 X 10(5) CFUc or more were transfused . Axillary nodes showed lower values than mesenteric nodes . They were mostly under the normal range but well over those of the irradiated controls . Frozen and thawed MBCs seem to be as effective as fresh cells for lymphopoietic restoration . The mesenteric nodes of dogs transfused with allogeneic MBCs showed higher cellularity and larger cortical-paracortical areas than those of dogs tranfused with approximately the same number of autologous cells . The repopulation of lymph nodes parallels that of the marrow.

Am J Pathol, 1976 Aug, 84(2), 239 - 58
The effect of leukocyte and platelet transfusion on the activation of intravascular coagulation by endotoxin in granulocytopenic and thrombocytopenic rabbits; Bohn E et al.; The effect of transfusion of peritoneal leukocytes, platelets, or cell suspension medium on the activation of intravascular coagulation and on the generation of capillary microclots was studied in 51 granulocytopenic and thrombocytopenic rabbits . Granulocytopenia and thrombocytopenia induced by feeding the cytoxic drug busulfan prevented the activation of intravascular coagulation and the occurrence of renal glomerular microclots after two injections of endotoxin . The transfusion of platelets into busulfan-pretreated rabbits increased the mean platelet count from 2,400 to 205,000 cells/mul, but platelet-transfused rabbits did not exhibit activation of intravascular coagulation after endotoxin injection . If however, granulocytopenic and thrombocytopenic rabbits were transfused with peritoneal leukocytes (1.0 X 10(9) cells/kg) before the second injection of endotoxin, activation of intravascular coagulation occurred, and microclot formation in renal glomerular capillaries was observed in a high percentage of animals . Positive reactions to endotoxin were obtained in leukocyte-transfused rabbits even with platelet counts of 1,000 cells/mul before the second injection of endotoxin . Thus platelets do not seem to be essentially involved in the activation of intravascular coagulation by endotoxin, whereas the presence of leukocytes is required for triggering endotoxin-induced generalized intravascular coagulation.

Hoppe Seylers Z Physiol Chem, 1976 Aug, 357(8), 1089 - 95
{Metabolism of nicotinic acid in plant cell suspension cultures, IV: Occurrence and metabolism of nicotinic acid N-alpha-arabinoside (author's transl)}; Leienbach KW et al.; Application of nicotinic acid to cell suspension cultures of Petroselinum hortense Hoffm., Daucus carota, Nicotiana tabacum and Nicotiana glauca leads to the formation of the recently isolated{2} nicotinic acid N-alpha-L-arabinoside . In these cell cultures the arabinoside is a metabolically active compound; the nicotinic acid moiety is used for NAD synthesis and nicotinic acid degradation involving decarboxylation and ring fission . N-Methylnicotinic acid (trigonelline) and nicotinic acid N-alpha-L-arabinoside occur alternatively in plant cell suspension cultures, but seem to fulfil the same function as a reserve form for nicotinic acid . Catabolism of nicotinic acid in parsley cell suspension cultures does not involve 6-hydroxynicotinic acid as an intermediate.

Hoppe Seylers Z Physiol Chem, 1976 Aug, 357(8), 1081 - 7
{Metabolism of nicotinic acid in plant cell suspension cultures, III: Formation and metabolism of trigonelline (author's transl)}; Heeger V et al.; Cell suspension cultures of Phaseolus aureus, Glycinemax., Cicer arietinum and Chenopodium rubrum convert nicotinic acid and nicotinamide into N-methyl nicotinic acid (trigonelline) . Application of {carboxyl-14C}- and {N-methyl-14C}nicotinic acid to cell cultures demonstrated that 1) the nicotinic acid moiety of trigonelline is funnelled into the pyridine nucleotide cycle, 2) trigonelline is demethylated partly oxidatively, but predominantly non-oxidatively, transferring the methyl carbon atom to still unknown acceptors, and 3) uptake of trigonelline by mung bean cell cultures is accompanied by demethylation and instantaneous remethylation reactions . Cell suspension cultures of parsley (Petroselinum hortense Hoffm.) show uptake but no metabolism of trigonelline . The data are compared with trigonelline metabolism in intact plants.

Acta Physiol Scand, 1976 Aug, 97(4), 457 - 69
Effect of glucagon on cyclic AMP, albumin metabolism and incorporation of 14C-leucine into proteins in isolated parenchymal rat liver cells; Dich J et al.; Parenchymal rat liver cells were isolated by the collagenase method and incubated in Krebs-Henseleit buffer containing 0.5% gelatin . The basal level of cyclic AMP in isolated cells was 0.52 nmol per g liver wet wt . Glucagon (10(-10)-10(-6) M) caused a significant increase in the level of cyclic AMP . Maximum levels were obtained 2-15 min after addition of glucagon . Repeated administration of glucagon caused a new increase in cyclic AMP, but the response was lesser than after the first addition of glucagon, indicating refractoriness to glucagon . The rate of albumin secretion was 4.6 mug/min per g liver wet wt . This is about the rate found in the perfused liver, Glucagon (10(-8-10(-6) M) inhibited albumin secretion and the incorporation of 14C-leucine into albumin, into total proteins in the medium and into total proteins in the cell suspension . The effect of glucagon on albumin secretion is compatible with an effect on the rate of synthesis . A positive correlation existed between the maximal level of cyclic AMP after glucagon administration and the inhibition of both albumin secretion and the incorporation of 149leucine.

J Virol, 1976 Aug, 19(2), 325 - 30
Encephalomyocarditis virus RNA: variations in polyadenylic acid content and biological activity; Hruby DE et al.; Encephalomyocarditis (EMC) viral RNA was isolated from purified virus grown in Ehrlich ascites tumor cells . The viral RNA was found to contain polyadenylic acid {poly(A)} regions that were very heterogeneous in length . Chromatography of the EMC viral RNA on oligo(dT)-cellulose columns separated the RNA into three distinct fractions (peaks 1 to 3) . Approximately 20% of the EMC viral RNA appeared as peak 1, 40% as peak 2, and 40% as peak 3 . The RNA in each fraction appeared to be intact as shown by co-sedimentation with 35S unfractionated EMC viral RNA in SDS-sucrose density gradients . Approximately 95 to 100% of peaks 1 and 3, and 60 to 70% of peak 2, reappeared at the same elution position after rechromatography on oligo(dT)-cellulose . The RNA in peak 1 contained poly(A) with an average length of 16 nucleotides, peak 2 contained poly(A) with an average of 26 nucleotides, and peak 3 contained an average of 74 nucleotides in its poly(A) region . The distribution in the three fractions, as well as the average length of the poly(A) moieties, was relatively unaffected by changes in the cell suspension medium used during infection . Finally, each of the three viral RNA fractions was assayed for biological activity using an infectious RNA assay on L-cell monolayers . Infectivity of the viral RNA was found to increase with poly(A) length, with peak 3 viral RNA being approximately 10 times more infectious than peak 1 viral RNA.

Hoppe Seylers Z Physiol Chem, 1976 Aug, 357(8), 1069 - 80
{Metabolism of nicotinic acid in plant cell suspension cultures: II; Isolation, characterization and enzymology of nicotinic acid N-alpha-arabinoside (author's transl)}; Leienbach KW et al.; A very hydrophilic compound was isolated from parsley cell suspension cultures in high yield after application of nicotinic acid . Using chemical, chromatographic and spectroscopic procedures the structure of this new plant constituent has been elucidated as nicotinic acid N-alpha-L-arabinopyranoside . This structure has been proved by chemical synthesis . An arabinosyltransferase was isolated from parsley cell suspension cultures and purified about 19-fold . The enzyme converted nicotinic acid N-alpha-arabinoside with UDP to nicotinic acid and UDP-arabinose . pH-Optimum (pH 7.0-8.0), Km value for nicotinic acid N-alpha-L-arabinoside (2.2 X 10(-4) mol/l) and mol . wt . (app . 70 000) of the transferase were measured . Function and biosynthesis of the arabinoside in cell cultures are discussed.

Brain Res, 1976 Jul 30, 111(2), 311 - 20
Selective cell association of catecholamine neurons in brain aggregates in vitro; Levitt P et al.; Brain tissues (aggregates) were reconstructed in vitro from dissociated single cell suspensions derived from 12- to 18-day embryonic mouse midbrain containing the substantia nigra . The application of the Falck-Hillarp histofluorescence method to these cell systems allows the visualization and identification of this specific population of developing catecholamine (CA) neurons during their reassembly, differentiation and histogenetic patterning in vitro . CA neurons are unselectively distributed in the initial dissociated cell suspension and in the reaggregating tissue up to 24 h . By 48 h the CA neurons have selectively associated into small clusters which further coalesce into a thick and elongated band along one margin of the aggregate by 96 h . This structure is similar in organization to the morphology exhibited by substantia nigra neurons in situ during their migratory phase in normal development . In addition, the differentiated neurons observed in the later aggregates appear to produce normal processes . Catecholamine analyses show a significant increase in dopamine and noradrenaline levels during the process of differentiation and histogenetic organization in vitro.

J Biol Chem, 1976 Jul 25, 251(14), 4428 - 35
Depletion of 18O from C18O2 in erythrocyte suspensions . The permeability of the erythrocyte membrane to CO2; Silverman DN et al.; The depletion of 18O from CO2, caused by the exchange of oxygen between CO2 and water during the hydration-dehydration cycle, is catalyzed by carbonic anhydrase . This depletion process at chemical equilibrium in the presence of erythrocytes is biphasic, exhibiting a very rapid depletion rate immediately following the addition of cells to an isotonic solution containing 18O-enriched CO2, followed by a much slower depletion rate . It is hypothesized that these depletion characteristics are caused by the diffusion of labeled CO2 into erythrocytes where depletion occurs rapidly due to the large intracellular carbonic anhydrase content . Kinetic equations which describe this hypothesis are solved and a rate constant is obtained which represents the depletion of 18O in CO2 caused by the presence of red cells . These are equilibrium experiments with no net uptake or loss of CO2 in the cells . Consequently, depletion processes are not limited in rate by bicarbonate-chloride exchange or proton distribution across the membrane . The purpose of these measurements is to determine whether the rate of 18O depletion in red cell suspensions is determined by carbonic anhydrase activity in the cell or by the diffusion process by which CO2 enters the cell . This goal is achieved by partially inhibiting carbonic anhydrase with acetazolamide . The rate constant representing 18O depletion caused by the presence of red cells is unchanged, even though up to 90% of carbonic anhydrase is inhibited . From this rate constant the permeability constant of the membrane of rat erythrocytes to CO2 at 25 degrees and pH 7.4 is determined to be (7.6 +/- 1.2) X 10(-3) cm s-1 in the presence of 3.2 mM picrate, a passive anion diffusion inhibitor intended to block HCO3 -flux across the membrane . Using no picrate and allowing HCO3-flux to introduce an error in the measurements, the permeability constant is (1.6 +/- 0.4) X 10(-2) cm s-1 . The permeability constants measured by this technique include the diffusion barrier to CO2 not only of the red cell membrane but also of a portion of the intracellular medium.

Biochemistry, 1976 Jul 13, 15(14), 3138 - 45
Angular scattering analysis of the circular dichroism of biological cells . 2 . The red blood cell; Gitter-Amir A et al.; A detailed interpretation of the grossly distorted ultraviolet absorption and circular dichroism spectra of the intact red blood cell is given, including an evaluation of the effects of protein conformation, detector geometry, cell hemoglobin content, and refractive index on the calculated cell spectra . The origins of the major differences between cell and hemoglobin solution spectra were quantitatively accounted for in terms of differential scatter and absorption flattening, with the latter effect dominating the picture . The relatively low sensitivity of the red blood cell suspension circular dichroism spectrum to hemoglobin conformation is due to the order of magnitude flattening of circular dichroism intensity . The importance of accounting for instrumental light detection geometry and the intense small angle scattering (less than 8 degrees) for a range of particle sizes (0.1-5 mum) is made clear.

Cell Tissue Kinet, 1976 Jul, 9(4), 313 - 23
A technique for determining the proportion of the clonogenic cells in S phase in ENT6 cell cultures and tumors; Rockwell S et al.; The survival of cultured EMT6 cells was examined after treatment with hydroxyurea (HU) or high specific activity tritiated thymidine (3H-TdR) . The concentrations of the agents, duration of exposure to the agents, and post-exposure treatment of the cultures were found to influence the cell survival; the effects of these factors are reported . Conditions were defined under which the proportions of cells killed by HU and by 3H-TdR were the same and were also the same as the proportion of labeled cells seen on autoradiographs of cultures labeled with small doses of 3H-TdR . Under these conditions, either 3H-TdR or HU could be used to determine the proportion of the clonogenic cells in S phase . Single cell suspensions prepared from solid EMT6 tumors were treated in vitro with HU or 3H-TdR, using the conditions found optimal for each agent with cultured cells . The proportion of the tumor cells killed by treatment with HU in vitro was the same as the proportion killed by HU in vivo and as the proportion labeled by 3H-TdR in vivo, and incubation of tumor cell suspensions with HU in vitro appeared to provide a valid measurement of the proportion of clonogeneic tumor cells in S phase . Incubation of tumor cell suspensions with 3H-TdR in vitro proved difficult to perform and the results were relatively unreliable because of severe problems with reutilization of 3H-TdR during the incubation for colony formation.

Immunology, 1976 Jul, 31(1), 129 - 38
Rabbit lymphoid cells . II . Anti-allotype antisera, lipopolysaccharide and other bacterial and fungal mitogens as probes for the identification of B-cell subpopulations; Shek PN et al.; Removal of adherent cells or complement-mediated killing of rabbit thymus lymphocyte antigen (BTLA) bearing rabbit T lymphocytes did not abolish the responsiveness (increased thymidine incorporation) of lymphoid cells to antibody against immunoglobulin allotype, Nocardia water-soluble mitogen (NWSM), pneumococcal polysaccharide SIII (PPSIII), S . abortus lipopolysaccharide (LPS), lipid A conjugated to bovine serum albumin and a crude preparation containing C polysaccharide from the cell wall of Diplococcus pneumoniae . Isologous and heterologous antisera, directed against different portions of the Ig receptor, differed in their capacity to enhance thymidine incorporation . The difference in mitogenicity of these antisera was discussed in terms of the accessibility of cell-bound immunoglobulin receptor sites . Spleen cells, responsive to anti-allotype (Ab4) antiserum and B-cell mitogens, NWSM and PPSIII, were characterized by velocity sedimentation . The mean volume of NWSM- and PPSIII-responsive cells was larger than that of the cells responsive to anti-allotype antiserum . Fractionation of spleen cells on glass bead columns yielded a population of non-adherent cells which were two to six times as responsive to anti-Ab4 antiserum as the original spleen cell suspension . The responsiveness of peripheral blood lymphocytes to anti-Ab4 antiserum was significantly greater than that of spleen cells . On the other hand, spleen cells were more responsive to PPSIII than were cells from the peripheral blood, the popliteal and the mesenteric lymph nodes.

Blood, 1976 Jul, 48(1), 33 - 9
Insulin binding of acute lymphocytic leukemia cells; Esber EC et al.; Because of differences in insulin binding of cultured lymphoic cell lines, T- and B-cell surface receptor and 125I-insulin binding studies were performed on the bone marrow and peripheral blood leukocytes of 13 children with active acute lymphocytec leukemia . Based on surface receptors, nine patients had null-cell disease and four had T-cell disease . The mean per cent insulin binding of the bone marrow cells from the null-cell patients was 10.0% +/- 8.1 and from the T-cell patients was 0.18% +/- 0.13 . The mean insulin binding of the cell suspensions of the peripheral blood from the null-cell patients was 7.3% +/- 7.5 and 0.07% +/- 0.06 from the T-cell patients . Displacement studies with nonradioactive insulin indicated that null leukemic cells bore specific binding sites . These results indicated that there may be metabolic as well as surface membrane heterogeneity among the acute lymphocytic leukemias of childhood.

J Immunol, 1976 Jul, 117(1), 151 - 4
Studies on the maturation of immune responsiveness in the mouse . II . Role of the spleen; Landahl CA et al.; Experiments were designed to investigate the role of the spleen in the development of the murine immune system . By using mice splenectomized within 24 hr of birth, as well as mice with a hereditary, congenital absence of the spleen, the primary immune response to sheep erythrocytes was examined . The immunocompetence of lymph node cells from spleenless or control mice was assessed in vitro, in organ and in cell suspension cultures, and in vivo, by transfer into lethally irradiated syngeneic recipients followed by antigenic stimulation . The immunologic capacities of thymus and bone marrow cells were similarly tested by injection separately or in combination into irradiated syngeneic mice . Lymph node cells from spleenless animals appeared fully competent both in vitro and in transfer experiments . Neither neonatal splenectomy nor congenital absence of the spleen significantly reduced the capacity of bone marrow or thymus cells to participate in the immune response to sheep erythrocytes.

Mikrobiologiia, 1976 JUL-AUG, 45(4), 655 - 60
{New brown chlorobacteria Prosthecochloris phaeoasteroidea nov . sp.}; Puchkova NN et al.; Two strains of new photosynthetic bacteria were isolated from salt meromictic lakes Mogilnoye and Faro . The bacteria are abligate phototrophic anaerobic cultures which utilize H2S as an electron donor by oxidizing it to elementary sulphur and sulphates . Sulphur is liberated outside the cell . The cultures contain bacteriochlorophyll e and carotenoids of the isorenierathene type . Photosynthetic structures are represented by chlorobium-vesicles . According to these properties, the cultures belong to the Chlorobiaceae family . The bacteria have no gas vacuoles . The cells form 10--20 apophyses-prosthecae which is typical of the Prostheocochloris genus . The new strains differ from Prosthecochloris aestuarii by the brown colour of the cell suspension, the composition of pigments, and ecology . They are classed as a new species Prostheocochloris phaeoasteroidea nov . sp . Diagnosis of the new species is presented.

In Vitro, 1976 Jul, 12(7), 485 - 94
The role of the gas phase in the greening and growth of illuminated cell suspension cultures of spinach (Spinacia oleracea, L.); Dalton CC et al.; The gas phase developed above spinach suspension cultures critically affected their growth and greening . Ethylene accumulation inhibited greening; this effect of ethylene was antagonised when the culture gas phase was enriched with carbon dioxide . Greening was enhanced by reducing the partial pressure of oxygen below the air level; this effect was observed when oxygen supply did not restrict growth.

Scand J Haematol, 1976 Jul, 17(1), 71 - 7
Preparation of concentrated platelet suspensions by dehydration against polyethyleneglycol 20,000; Akkerman JW et al.; Gel filtered platelet suspensions were concentrated by repeated dehydration against polyethyleneglycol 20,000 followed by dialysis against slightly hypotonic buffer . This method increased the platelet concentration 2-3 times with a recovery of 80-100% . The final cell suspension closely resembled the original platelet rich plasma as tested by a number of platelet tests.

Blood, 1976 Jul, 48(1), 139 - 47
Identification of monocytes in suspensions of mononuclear cells; Rothbarth PH et al.; A new histochemical technique for morphological studies of mononuclear cells and granulocytes, based on fluorescent staining with methyl green, pyronine Y, and stilbene-isothiocyanato disulfonic acid (MPS stain) is described . The method was applied to mononuclear cells isolated from the blood of normal human subjects by Ficoll-Isopaque density centrifugation . Three cell populations were distinguished, mainly on the basis of differences in morphology and cytochemistry, utilizing the MPS stain . One of the cell types had many of the morphological characteristics of the monocyte . This technique, augmented by lysosomal content and endocytosis capacity studies, revealed contimination of the cell suspension with a larger percentage of monocytes than has usually been reported in the literature.

J Immunol, 1976 Jul, 117(1), 337 - 42
Divergent effects of cyclophosphamide administration on mononuclear killer cells: quantitative depletion of cell numbers versus qualitative suppression of functional capabilities; Hunninghake GW et al.; The effects of various regimens of cyclophosphamide administration on guinea pig peripheral blood leukocytes were studied . Cyclophosphamide-induced immunosuppression was assessed by the effect of drug administration on the proportions and absolute numbers of leukocyte populations, and by the effect on functional capabilities of unfractionated and adherent cell-depleted mononuclear cell suspensions as measured by the PHA-induced cellular cytotoxicity and antibody-dependent cellular cytotoxicity assays against chicken erythrocyte targets . Intraperitoneal administration of five daily doses of cyclophosphamide (5 mg/kg) caused a modest absolute leukopenia but no change in cytotoxic effector function of the mononuclear cells remaining in the circulation . As the dosage of cyclophosphamide was increased to 20 mg/kg/day to produce a pronounced leukopenia, a profound neutropenia (less than 300 polymorphonuclear leukocytes/mm3) together with a marked decrease in mononuclear cell effector function was noted . A single i.p . injection of cyclophosphamide (100 mg/kg), which produced identical degrees of leukopenia of each leukocyte class as did daily administration of cyclophosphamide (20 mg/kg/day), caused no change in mononuclear cell effector function when compared to saline controls . Complement receptor-bearing and Fc-receptor bearing mononuclear cells were decreased to the same degree by both regimens of cyclophosphamide administration . Removal of adherent cells from mononuclear cell suspensions by column purification resulted in a marked decrease in cytotoxic effector function at low effector to target ratios . At higher effector to target ratios there was no difference in cytotoxic effector function between unfractionated and column-purified cells . In contrast, the functional defect in mononuclear cell suspensions from animals that received five daily doses of cyclophosphamide (20 mg/kg) could not be compensated for at higher effector to target ratios, indicating that this functional defect was not an artifact of relative depletion of monocytes by cyclophosphamide, but was due to an actual suppression of the effector functional capabilities of the killer cells . This study indicates that, dependent on the particular regimen of drug administration, the quantitative depletion of mononuclear cell populations by cyclophosphamide administration can be clearly distinguished from the qualitative effect on certain functional capabilities of surviving cells.

Clin Exp Immunol, 1976 Jul, 25(1), 95 - 102
Schistosoma mansoni in baboons . Antibody-dependent cell-mediated damage to 51Cr-labelled schistosomula; Butterworth AE et al.; A technique is described for estimating cell-mediated damage to the larval stages of Schistosoma mansoni that occur in the mamalian host (schistosomula), by measuring release of 51Cr from labelled organisms . This technique, although widely used for assaying cytotoxicity to single cell suspensions or monolayers, has not previously been applied to a multicellular parasite . It is more objective than microscopical assays, and allows the processing of larger numbers of samples . The new method has been used for the detection and quantification of cell-dependent cytotoxic antibodies in infected baboons . The effector cell in normal baboon peripheral blood, as in man, is associated with a neutrophil- and eosinophil-enriched fraction . Cytotoxic antibodies appear in the serum about 4 weeks after a primary infection, rising to a peak at 7-10 weeks, and then declining . In some animals, a second rise towards 30 weeks was observed . There were no consistent differences between groups of baboons exposed to 1000 cercariae, 200 cercariae, and 200 cercariae administered at each of five monthly intervals . The possible relationship between cell-dependent cytotoxic antibodies and resistance to reinfection in infected animals is discussed.

Acta Pathol Microbiol Scand {A}, 1976 Jul, 84(4), 297 - 300
Heterogeneity in in vitro response to progesterone and melphalan of mammary tumours induced in the rat by 7,12-DMBA; Aspegren K et al.; Five mammary tumours induced in rats by 7, 12-DMBA were each divided into four sections, and studied as cell suspensions in vitro for response to melphalan or progesterone measured as H3-thymidine incorporation . Heterogeneity towards melphalan and progesterone was found within all five tumours, but the mode of reaction of the two drugs differed . The biological relevance of these findings is discussed.

Br J Cancer, 1976 Jul, 34(1), 39 - 45
A soft agar colony assay for Lewis lung tumour and B16 melanoma taken directly from the mouse; Courtenay VD; A soft agar colony assay has been developed for the B16 mouse melanoma and the Lewis lung tumour . The special features of the technique are the use of a gas phase with 5% O2 instead of air and the addition of rat red blood cells . Single cell suspensions are prepared by trypsinization from the solid tumour and the cells are plated out in 0-3% agar over a layer of 0-5% agar in 30-mm Petri dishes . After 8 to 15 days' incubation in 5% O2, colonies of more than 50 cells are produced . Plating efficiencies of between 30 and 50% are usually obtained . The addition of up to 10(4) heavily irradiated tumour cells gives some further improvement in plating efficiency for the B16 melanoma but not for the Lewis lung tumour . Applications of the technique to measure cell survival in the two tumours after treatment with cytotoxic drugs and radiation are reported . The scatter of experimental points is relatively small, and in comparative experiments good agreement has been obtained with results using in vivo assay techniques.

Stain Technol, 1976 Jul, 51(4), 237 - 40
Differential staining of tannin in sections of epoxy-embedded plant cells; Parham RA et al.; A staining procedure is described for the light microscopic localization of ergastic tannins in epoxy sections of plant cells embedded for study by transmission electron microscopy . Callus and cell suspensions of Pseudotsuga menziesii and Pinus taeda fixed in glutaraldehyde:acrolein and then OsO4, followed by epoxy embedding, were sectioned 0.5 mum thick, stained on a glass slide with ethanolic Sudan black B at 60 C as described by Bronner, and then mounted in Karo syrup . Tannin deposits stained brownish-orange and were easily distinguished from lipid bodies of similar size, which stained dark blue to black, and from starch grains, which were unstained . The significance of this differential polychromasia was confirmed by transmission electron microscopy . This staining procedure should prove valuable in the cytoplasmic evaluation of the plant cell ergastics (especially tannins) via light microscopy whether or not electroc microscopic examination is intended.

J Gen Microbiol, 1976 Jul, 95(1), 159 - 65
Formation of ethylene by Escherichia coli; Primrose SB; Escherichia coli strain SPA O converts methionine to ethylene by an inducible enzyme system . L-Cysteine, L-homocysteine, methionine derivatives and the sulphur-containing analogues of L-methionine also act as precursors of ethylene . Ethylene is produced by cell suspensions only in the presence of air; cell-free preparations can produce ethylene aerobically and anaerobically, but the extent to which they do so depends on the mode of culture growth . Light stimulates ethylene production by cell suspensions and its presence is essential for production by cell-free preparations . The kinetics of ethylene biogenesis and its pH and temperature optima suggest that ethylene is a secondary metabolite.

Am J Pathol, 1976 Jul, 84(1), 1 - 10
A decrease in cell-mediated immunity in uremia associated with an increase in activity of suppressor cells; Raskova J et al.; The graft-versus-host (GVH) reactivity of uremic and control spleen cells was studied by popliteal lymph node assay in the rat . The reaction evoked by cells from animals with severe uremia was conspicuously weaker than that evoked by control cells . The magnitude of the GVH reaction induced by control cells was directly proportional to dose, while with the uremic cells the same increases in dose led only to insignificant increases in the strength of the GVH reaction . When mixtures of syngeneic control and uremic cells were used, the GVH reactivity of the control cells was suppressed . The activity of uremic spleen cells can be enhanced (restored) by removal of the sub-population of cells adherent to glass wool . The GVH reaction induced by uremic cells so treated became directly proportional to dose . The removal of the adherent cell population from the uremic spleen cell suspension also led to the disappearance of the suppressor effect in mixtures of control and uremic cells . These results indicate that a decrease in GVH activity of rat uremic spleen cells is due to an increase in suppressor cell activity in the uremic spleen cell population.

J Bacteriol, 1976 Jul, 127(1), 14 - 23
Role of polyadenylic acid in a deoxyribonucleic acid-membrane fraction extracted from pneumococci; Firshein W et al.; After the addition of radioactive polyadenylic acid to cell suspensions of pneumocci, part of the radioactivity becomes associated with a deoxyribonucleic acid (DNA)-membrane fraction extracted from the cells . A variety of techniques show that a portion of this associated radioactivity may represent oligoadenylates complexed to DNA, probaby as part of a ribonucleic acid (RNA) component . Polyadenylic acid, which had previously been shown to enhance DNA synthesis in cell suspensions (Firshein and Benson, 1968), also enhances the extent of DNA synthesis by the DNA-membrane fraction in vitro under specific conditions of concentration and conformation . The mechanism of action of this enhancement may be related to the ability of oligoadenylates to increase the number of initiation sites for DNA replication by stimulating the production of an RNA primer, thus providing additional 3'-OH groups with which DNA polymerase can react.

J Biol Chem, 1976 Jun 25, 251(12), 3539 - 44
Dietary regulation of 6-phosphogluconate dehydrogenase synthesis; Procsal D et al.; The relative rates of synthesis and degradation for rat liver 6-phosphogluconate dehydrogenase have been determined in animals maintained at several dietary states . Relative rates of synthesis were determined by pulse-labeling the enzyme either in live rats and determining the radioactivity in the purified enzyme or in whole cell suspensions of hepatocytes followed by precipitation of the enzyme with a specific antiserum . The relative rate of synthesis of the enzyme in rats fed a high carbohydrate fat-free diet was approximately 3.7 to 5.6 times greater than that in animals fed a pellet diet or in fasted rats, respectively . In contrast, a half-life of 13 to 19 hours was determined for the degradation of the enzyme in all three nutritional states . We have concluded that nutritional alterations in the levels of this enzyme in rat liver are caused by alterations in the rate of enzyme synthesis . Glucagon has no effect on the rate of synthesis of this enzyme.

Calcif Tissue Res, 1976 Jun 14, 20(3), 251 - 9
Osteopetrosis of microphthalmic mice -- a defect of the hematopoietic stem cell.?
Loutit JF, Sansom JM.
The recessive genes mi and gl in the homozygous state determine, among other phenotypic effects, osteopetrosis in the house mouse . From a stock carrying mi derived from Gruneberg (1963) the mi gene was bred into the standard CBA/H inbred strain . Microphthalmic mice of these two stocks and their hybrids were treated as newborn by intraperitoneal injection and at weaning or maturity by intravenous injection of cell suspensions containing hematopoietic stem cells from phenotypically normal mice . Resolution of much of the osteopetrosis but not the other phenotypic effects occurred within a few months in the majority of cases, provided syngeneic or H-2 compatible allogeneic cells were given: it did not occur spontaneously or on giving H-2 incompatible cells or on giving compatible material by an inappropriate route . The results accord with hypotheses that (1) osteoclasis of scaffoldtype woven bone is impaired in mi mi, (2) that osteoclastic cells are derived through circulating monocytes from hematopoietic stem cells, and (3) in mi mi this defect can be overcome by a transplant of normal hemopoietic stem cells.

Br J Cancer, 1976 Jun, 33(6), 600 - 5
Influence of exogenous tRNA on growth of transplantable 32P-induced osteosarcomata; Geddes-Dwyer V et al.; The weights of osteosarcomata that arose 22 days after the s.c . injection of cell suspensions (of whold tumours) that had been exposed in vitro to tRNA were significantly different from the weights of those arising from untreated cells . The tRNA was isolated by phenol extraction and DEAE-cellulose chromatography from eviscerated full-term rat embryos, from rat mesenchymal (granulation) tissue and from rat anaplastic osteosarcomata . Tumours developing from osteosarcoma cells treated with either embryonic or normal mesenchymal tRNA were reduced in weight by 76% and 60% respectively . These effects could not be explained as a toxic consequence, because tumour weight was increased by 128% after exposure of cells to osteosarcoma tRNA . In this osteosarcoma model it appears that tumour weights can be influenced in different ways by tRNA from different sources.

Gann, 1976 Jun, 67(3), 431 - 6
Human breast cancer serially transplantable in nude mice in ascites form; Hirohashi S et al.; Cell suspension of a human breast cancer cell line (Hattori line) was injected intraperitoneally into an athymic nude mouse to produce ascites form breast cancer (peritoneal carcinomatosis) . Subsequent serail transfers of cancer cells in ascites were also successful in mice . All male and female nude mice injected 1 X 10(7) tumor cells died of accumulation of ascites after a latency period averaging 4 weeks, with one exception which died of a wasting disease . Multiple lung metastases were observed in some mice . The tumor cells retained cytological characteristics of the original cell line, and histology of the infiltrating tumor in the peritoneum and omentum was that of poorly differentiated adenocarcinoma . Differentiation not only toward acinar or duct lining cells but also toward myoepithelial cells was observed by histochemistry, immunohistochemistry, and electron microscopy.

J Pharmacol Exp Ther, 1976 Jun, 197(3), 615 - 22
Studies of a transplantable rat pheochromocytoma: biochemical characterization and catecholamine secretion; Chalfie M et al.; The biochemistry and secretory characteristics of a transplantable rat pheochromocytoma have been studied . This tumor possesses the enzyme required for the biosynthesis of norepinephrine from tyrosine, and stores large amounts of norepinephrine (33 +/- 3 nmol/mg of protein) . The tumor does not have detectable levels of noradrenalin N-methyltransferase, nor does it contain significant amounts of epinephrine . Approximately two-thirds of the catecholamine content, and one-half of the dopamine beta-monoxygenase activity in the tumor can be isolated in a granule fraction by sedimentation . This granule fraction also contains ATP; the molar ratio of catecholamine to ATP in this granule fraction (5.6 +/- 0.9) is similar to that found in granules prepared from normal adrenal glands . Cell suspensions were prepared by mechanical disruption of the tumor . Incubation of these cell suspensions in media containing 56 mM K+, or the divalant cation ionophores, lasolocid or A23187, leads to the release of catecholamine from these cells . The cells do not secrete catecholamine in response to acetycholine . Catecholamine release induced by 56 mM K+ appears to be by exocytosis, since this release is dependent upon extracellular Ca++, and is accompanied by the release of dopamine beta-monooxygenase, but not of lactate dehydrogenase, from the cells . The mechanism by which the ionophores stimulate catecholamine secretion has not been established.

J Exp Med, 1976 Jun 1, 143(6), 1453 - 63
A quantitative assay for transformation of bone marrow cells by Abelson murine leukemia virus; Rosenberg N et al.; A quantitative Abelson murine leukemia virus (A-MuLV) lymphoid cell transformation assay has been developed using a semisolid agarose culture system . Under these conditions lymphoid cell transformation was shown to vary linearly with the dose of A-MuLV used . The susceptibility of bone marrow cells from different strains of mice to A-MuLV-induced transformation can be estimated using the agarose assay . Strains with bone marrow cells of high, medium, and low susceptibility to A-MuLV can be identified . The assay has been used to study the susceptibility of cells from lymphoid organs of fetal and adult mice to A-MuLV . Cell suspensions from fetal liver, adult bone marrow, and adult spleen are susceptible to A-MuLV, while thymocytes are resistant to A-MuLV-induced transformation . Bovine serum albumin gradient fractionation of bone marrow cells before infection with A-MuLV demonstrates that the majority of A-MuLV-sensitive cells are recovered in a broad band partially overlapping the majority of the nucleated cells . The agarose assay system allows study of A-MuLV-lymphoid cell interaction at the level of single cell-single virus particle interaction.

Circ Res, 1976 Jun, 38(6 Suppl 2), 117 - 21
Changes in cardiovascular and adrenal cortical responses to angiotensin III induced by sodium deprivation in the rat; Peach MJ et al.; The restriction of dietary sodium intake is known to depress the cardiovascular responses to angiotensin II and increase the sensitivity of the adrenal zona glomerulosa to this steroidogenic octapeptide . In sodium-repleted animals, angiotensin III is a weak pressor substance and a potent stimulant of aldosterone biosynthesis . The effect of a low sodium diet on vascular and steroidogenic responses to angiotensin II and angiotensin III was investigated . In nephrectomized rats, angiotensin III had one-third of the pressor activity relative to angiotensin II when either normal or sodium-deprived animals were compared . When administered subcutaneously (sc) to rats, angiotensin II and III induced comparable steroidogenic responses, whereas only angiotensin II significantly elevated blood pressure . The comparison of cell suspensions from control adrenals with suspensions of adrenals from sodium-deprived animals showed that the zona glomerulosa from rats on low sodium diets had increased wet weight (20%), cell protein (25%), and basal steroidogenic rats (45%) . Adrenocorticotropic hormone (ACTH)-induced responses in adrenal cells from low sodium animals were about twice the responses of cells from normal adrenals . Angiotensin II and III stimulated the cortex at a threshold concentration of 5 X 10(-10) M and induced a maximum response at about 5 X 10(-8) M in cells prepared from normal rat adrenals . In cells dispersed from adrenal capsules of sodium-deprived rats, the maximal steroidogenic response to angiotensin II occurred at 3 X 10(-8) M, whereas angiotensin III was maximal at 1 X 10(-9) M . Aldosterone synthesis induced by both peptides was increased approximately 45% in adrenal cells from low salt rats . At 0.9 mumol/kg, sc, Sar-1, Ile-8-angiotensin II antagonized cardiovascular responses to angiotensin II and did not alter aldosterone in the sodium-deprived rat . In contrast, treatment with Ile-7-angiotensin III blocked the adrenal cortex but not the vascular actions of angiotensin II . These data are consistent with a role for angiotensin III in the renin-angiotensin-aldosterone response to sodium deprivation.

Laryngol Rhinol Otol (Stuttg), 1976 Jun, 55(6), 487 - 90
{Percent distribution of B-Lymphocytes in human tonsils at various ages}; Uhlmann C et al.; B-Lymphocytes of the classes G, M and A were determined by use of heavy-chain-specific fluorescent antisera from 67 children between 2 and 14 years of age and from 15 adults up to 60 years of age . Tonsils from which viable cell suspensions were investigated for B-Cells were classified histologically, according to their degree of lymphatic hyperplasia and inflammation . With increasing age, a statiscally significant decrease in percent G- and M-cells was observed while A-cells remained unchanged . With increasing severity and extent of inflammation and lymphatic hyperplasia, there occured a mild increase in percent M-cells . G-cells did not exhibit major changes under such conditions . It is suggested, that the tonsil may represent an early and fast reaching immunocompetent organ primarily determined for the production of large molecular IgM and IgA of less specificity.

Eur J Biochem, 1976 Jun 1, 65(2), 529 - 36
Enzymic synthesis of lignin precursors . Purification and properties of a cinnamoyl-CoA: NADPH reductase from cell suspension cultures of soybean (Glycinemax); Wengenmayer H et al.; A cinnamoyl-coenzyme A reductase catalyzing the NADPH-dependent reduction of substituted cinnamoyl-CoA thiol esters to the corresponding cinnamaldehydes was isolated from cell suspension cultures of soybean (Glycine max L . var . Mandarin) . A 1660-fold purification of the enzyme was achieved by (NH4)2SO4 fractionation, chromatography on DEAE-cellulose, hydroxyapatite and Sephadex G-100 and affinity chromatography on 5'-AMP-Sepharose . The apparent molecular weight of the reductase was found to be about 38 000 on the basis of the elution volume from a Sephadex G-100 column . Maximum rate of reaction was observed between pH 6.0 and 6.2 in 0.1-0.2 M citrate buffer at 30 degrees C . The enzyme was markedly inhibited by thiol reagents . The reductase showed a high degree of specificity for cinnamoyl-CoA esters . Feruloyl-CoA was the substrate with the lowest Km value (73 muM) and highest V (230 nkat/mg) followed by 5-hydroxy-feruloyl-CoA, sinapoyl-CoA, p-coumaroyl-CoA, caffeoyl-CoA and cinnamoyl-CoA . No reaction took place with acetyl-CoA . The Km value for NADPH varied with the type of substrate . Km values of 28, 120, and 290 muM were found with feruloyl-CoA, sinapoyl-CoA, and p-coumaroyl-CoA, respectively . The rate of reaction observed with NADH was only about 5% of that found with NADPH . The reaction products CoASH and NADP+ inhibited the reaction . The Ki values were in the range of 0.5-1 mM and the inhibition was of a noncompetitive (mixed) type . The role of the reductase in the biosynthesis of lignin precursors is discussed.

Dtsch Med Wochenschr, 1976 May 14, 101(20), 779 - 82
{Generalised herpes simplex virus infection presenting as an "acute abdomen" (author's transl)}; Kugler S et al.; A 23-year-old patient developed acute upper abdominal symptoms during in-patient treatment for vulvo-vaginitis . Clinical picture, scintigraphy and angiography suggested a space-occupying process of the liver . Laparotomy showed ascites and a congested liver covered with cell necroses . The patient died the day after the operation from circulatory failure . Virological investigations of liver and spleen cell suspensions as well as the ascites fluid led to the demonstration of herpes virus type 2 . The complement binding reaction gave a titre of 1:20 to herpes simplex virus . Disseminated herpes simplex virus infection is rare and in this case spread from the genital area.

Brain Res, 1976 May 7, 107(2), 345 - 54
Reduced glucocorticoid binding site concentration in cortical neuronal perikarya from senescent rats; Roth GS; Isolated neuronal perikarya from cerebral cortices of senescent (24-26-month-old) male rats exhibit a 55-65% reduction in the concentration of specific cytosol glucocorticoid binding sites when compared to mature counterparts (12-13 months) . Neuronal preparations from the two age groups are essentially identical with respect to yield, protein content, physiochemical integrity and purity as judged by enrichment for free glycine and reduction in carbonic anhydrase specific activity (relative to unfractionated cortical cell suspensions) . Adrenalectomy does not alter the number of glucocorticoid binding sites in either group, and age differences do not appear due to differential partitioning of sites between nucleus and cytoplasm . It is suggested that loss of receptors from the cortical neuron population represents a possible mechanism by which glucocorticoid responsiveness may be decreased during aging.

Lab Invest, 1976 May, 34(5), 489 - 94
Effect of HgCl2 on rat kidney cells in primary culture; Inamoto H et al.; Single cell suspensions, obtained from rat kidneys, were cultured with various concentrations of HgCl2 for different times to examine the effects on cellular synthetic activity . Unexpectedly, the RNA synthesis of kidney cells was stimulated with low doses of HgCl2, whereas it was inhibited with higher doses . Even at a higher dose, RNA synthesis was stimulated during early incubation but was inhibited during longer incubations . Thus, the effect of mercury showed a biphasic pattern both in dose-response and time-response relationships . Moreover, once the cells were exposed to HgCl2 for a certain period, RNA syntehsis was irreversibly inhibited . Since RNA synthesis was inhibited earlier than DNA or a protein synthesis, the RNA synthesizing system appeared most susceptible . Without HgCl2, by the time DNA synthesis reached its maximum, protein and RNA synthesis had already declined . In contrast, RNA synthesis of HgCl2-treated cells remained at its maximal level and showed no decline when DNA synthesis reached its peak.

J Immunol, 1976 May, 116(5), 1199 - 1203
IgM complex receptors on subpopulations of murine lymphocytes; Lamon EW et al.; Murine lymphocytes from spleen, lymph node, and thymus were examined for IgM complex receptors . Lymphocytes from all three organs were found to bind SRBC sensitized with IgM from various sources including: primary anti-SRBC serum, murine and rabbit anti-Escherichia coli LPS sera, and a murine IgM myeloma (MOPC 104E) . Rosette formation by lymphocytes with IgM-sensitized SRBC was inhibited by soluble antigen-IgM complexes but not by IgM or antigen alone . Rosette formation was also inhibited by human IgM (Fc)5mu but not by Fab mu . Antiserum and complement treatment of the cells and subsequent recovery of the viable cells by trypsinization, filtration, and washing revealed the IgM rosette-forming cell (RFC) in the thymus to be a T cell . Spleen on the other hand was found to contain both B and T cells capable of binding IgM sensitized SRBC . Removal of both B and T cells from spleen cell suspensions eliminated all IgM RFC . The IgM complex receptor was found to be trypsin insensitive . Anti-Ig column fractionation enriched IgM RFC in spleen and lymph node suspensions passed through the columns, whereas cells bearing surface Ig, IgG complex receptors, and C3 receptors were retained in the columns.

Histochem J, 1976 May, 8(3), 283 - 90
Microspectrophotometry of mitochondrial cytochrome P-450 in single adrenal cells; Rappay G et al.; The cytochrome P-450 is known to be a key enzymic component in steroid hydroxylation . Biochemically it is localized in adrenal cells, both in the mitochondrial and in the microsomal fractions . Owing to its characteristic light absorptivity, attempts were made at its localization and measurement in a microspectrophotometric system . Specific difference spectra were obtained in the cytoplasm of some cells from an adrenal cell suspension before and after saturation with carbon monoxide . Scanning at 450 nm showed slender absorption maxima after CO saturation randomyl distributed in the cytoplasm . These may be attributed to mitochondria or larger cytoplasmic functional units including mitochondria.

J Biochem (Tokyo), 1976 May, 79(5), 1035 - 42
Biochemical studies of pyrithiamine-resistant mutants of Escherichia coli K12; Kawasaki T et al.; The biochemical properties of strains (PT-R101 and PT-R108) of Escherichia coli K12 resistant to growth inhibition by pyrithiamine, and antimetabolite of thiamine, have been studied . Intracellular thiamine pyrophosphate concentration in these resistant strains was slightly but definitely higher than that in the parent strain . Thiamine synthesis from the pyrimidine and thiazole moieties of thiamine by cell suspensions was greater in the resistant strains than the parent strain . The activities of enzymes involved in thiamine biosynthesis in these pyrithiamine-resistant strains were 2-3 times higher than the parent strain (3301), except for thiamine-phosphate kinase, which was indetectable in in vitro assay of the activity . However, other evidence indicates that this enzyme is not defective but is functioning in vivo and, furthermore, that the negligible activity of this enzyme did not affect the growth rate of the mutants . The activities of these enzymes were further enhanced when PT-R101 was grown on 5mM adenine and were reduced almost to zero when the strain was grown on 0.1 muM thiamine in the same way as the parent strain . However, when these resistant strains were grown on a low concentration of thiamine such as 0,05 muM, thiamine synthesis by cell suspensions also decreased, but only to a limited extent compared with the parent strain . These results suggest that PT-R101 and PT-R108 are altered in the mechanisms of regulation of thiamine biosynthesis . Their altered properties might be due to a reduced binding affinity of the repressor protein, which is involved on the regulation of thiamine synthesis, for the corepressor, thiamine pyrophosphate,

Arthritis Rheum, 1976 May-Jun, 19(3), 555 - 62
Predominance of T cells in the lymphocytic infiltrates of synovial tissues in rheumatoid arthritis; Bankhurst AD et al.; Synovial tissues from 5 patients with rheumatoid arthritis (RA) were examined with immunofluorescence microscopy for the presence of lymphocytes with either bone marrow-derived (B) or thymus-derived (T) surface markers . Five synovial tissues with severe to mild lymphocytic infiltrations by bright field microscopy were examined in parallel with immunofluorescence . B cells were identified with a pepsin-digested fluoresceinated anti-F (ab')2 antiserum and T cells were detected with a specific rabbit anti-T lymphocyte antiserum . By these techniques 75-90% of the lymphocytes in these frozen sections were identified as T cells . Cell suspensions were also prepared by collagenase digestion of two of the five synovial tissues . The lymphocytes in these cell suspensions were predominantly T lymphocytes (78-85%) as shown by their ability to form spontaneous rosettes with sheep erythrocytes (E rosettes).

Infect Immun, 1976 May, 13(5), 1321 - 4
Modified hemolytic plaque technique for the detection of bluetongue virus antibody-forming cells; Oellermann RA et al.; A hemolytic plaque assay was developed for the detection of antibody-forming cells to bluetongue virus (BTV) . Sheep erythrocytes (SRBC), onto which BTV had been absorbed, served as the indicator of lysis due to the presence of BTV antibody-forming cells . The ratio of BTV to SRBC was found to be critical for optimum hemolytic plaque formation . For routine use, 50 mul of 12% BTV SRBC, 0.1 ml of a spleen cell suspension, and 0.5 ml of 0.5% agarose in a balanced salt solution were mixed and plated on a microscope slide precoated with 0.1% aqueous agarose . Slides were incubated for 1 h at 37 C in a humidified incubator and subsequently flooded with 0.4 ml of a 1:15 dilution of complement . Incubation was continued for a further 2 h before the hemolytic plaques were scored . It was not possible to establish BTV serotype specificity by this technique.

Eur J Immunol, 1976 May, 6(5), 317 - 20
Lymphocyte-mediated cytotoxicity against tumor cells . III Differentiation of concanavalin A-activated cytotoxic effector cells; Waterfield JD et al.; The maturation of selected T cell responses in the lymphoid organs of irradiated CBA mice was followed after adoptive transfer of syngeneic fetal liver cells . Mitogenic responsiveness to phytohemagglutinin (PHA) and concanavalin A (Con A) was found to reach control values 3 weeks after reconstitution in the thymus, spleen, and lymph node, of fetal liver repopulated animals . Spleen and lymph node cell reactivity in mixed lymphocyte culture reactions required 6 weeks to reach significant values . However, the ability of spleen cell suspensions to be activated by Con A into cytotoxic effector lymphocytes appeared after only 2 to 3 weeks . It is concluded that two functionally distinct T cell subpopulations exist in the spleen, one which can be activated into cytotoxic effector lymphocytes by Con A, and one which responds to alloantigens by DNA synthesis.

J Bacteriol, 1976 May, 126(2), 1017 - 9
Inhibition of dimethyl ether and methane oxidation in Methylococcus capsulatus and Methylosinus trichosporium; Patel R et al.; Metal-chelating or -binding agents inhibited the oxidation of dimethyl ether and methane, but not methanol, by cell suspensions of Methylococcus capsulatus and Methylosinus trichosporium . Evidence suggests that the involvement of metal-containing enzymatic systems in the initial step of oxidation of dimethyl ether and methane.

Thromb Haemost, 1976 Apr 30, 35(2), 350 - 7
Increased protein synthesis by human platelets during phagocytosis of latex particles in vitro; Bessler H et al.; A three-fold increase of protein synthesis by human platelets during in vitro phagocytosis of polystyrene latex particles was detected . During the first two hours of incubation, the percentage of phagocytizing platelets and the number of latex particles per platelet increased; by the end of the third hour, the first parameter remained stable, while the number of latex particles per cell had decreased . Vincristine (20 mug/ml of cell suspension) inhibited platelet protein synthesis . This effect was both time- and dose-dependent . The drug also caused a decrease in the number of phagocytizing cells, as well as in their phagocytotic activity.

Virchows Arch B Cell Pathol, 1976 Apr 29, 20(3), 197 - 204
Quantitative study of lymphoreticular infiltration into canine transmissible venereal sarcoma; Yang TJ et al.; Lymphoreticular cell (LRC) infiltration into tumour masses at different stages of growth after transplantation was studied in canine transmissible venereal sarcoma (CTVS) . The percent viable LRC of total viable cells in tumour suspensions shows an inverse correlation with the logs of tumour mass of adult dogs (R = -0.475, phi = 28, P less than 0.01), which suggests that the degree of LRC infiltration is a measure of the host immune response . However, an estimate of the surface area (S.A.) of the tumour rather well perfused with blood elements based on the formula S.A . = 5.43 (tumour mass in g)2/3 showed that the LRC mass present in a tumour was a function of its surface area . Thus, the inverse correlation of the percent viable LRC's in a viable tumour cell suspension to the log of the CTVS mass might not necessarily indicate that the infiltrated LRC's were active as immune effector cells . The correlation does show that, as the CTVS size increases, the volume of the necrotic center increases more rapidly than the volume perfused with blood and, therefore, the percent viable LRC's in CTVS decreases with CTVS size increase.

J Biol Chem, 1976 Apr 25, 251(8), 2511 - 9
Utilization of exogenous GDP-mannose for the synthesis of mannose-containing lipids and glycoproteins by oviduct cells; Struck DK et al.; Suspensions of oviduct cells were prepared by subjecting oviduct tissue to sequential incubations with EDTA, alpha-chymotrypsin, and crude collagenase, followed by a final incubation with EDTA . Cells isolated in this way incorporate mannose from exogenous GDP-mannose into mannosyl-lipid, oligosaccharide-lipid, and glycoprotein(s) . Based on several criteria, the mannosyl-lipid is identical with mannosyl-phosphoryldolichol . Similarly, the oligosaccharide-lipid appears to be identical with the oligosaccharide-lipid synthesized in vitro (Lucas, J . J., Waechter, C . J., and Lennarz, W . J . (1975) J . Biol . Chem . 250, 1992-2002) . In contrast, the glycoproteins are much lower in molecular weight than those labeled in cell-free preparations . Using intact oviduct cell suspensions it was found that: (a) exogenous GDP-mannose, not its breakdown products, serves as the direct mannosyl donor; (b) experiments using mixtures of known proportions of broken and intact cells, as well as studies with metabolic inhibitors, indicate that greater than 50% of the observed incorporation of mannose from GDP-mannose was catalyzed by enzymes associated with intact cells, rather than broken cells or membrane fragments; (c) incorporation of mannose from GDP-mannose into the mannosyl acceptors does not require energy and proceeds without significant uptake of GDP-mannose into trichloroacetic acid-soluble components of the cells; (d) under conditions where labeled guanosine incorporation into nucleic acids is readily detected, no incorporation of the guanosine moiety of {3H}GDP-mannose is observed . These results indicate that the enzymes catalyzing synthesis of lipid-linked intermediates involved in glycoprotein synthesis are not only associated with intracellular membranes, but with the plasma membrane as well.

Acta Pathol Microbiol Scand {C}, 1976 Apr, 84(2), 105 - 11
Tumor Fc receptors and tumor-associated immunoglobulins; Tonder O et al.; Tissue sections and cell suspensions from ten malignant tumors were tested for Fc receptors using sheep erythrocytes sensitized by rabbit IgG antibodies . Surface bound IgG on cells from the same tumors were estimated using an antiglobulin consumption test with 125I labelled human IgG as reference . The amount of IgG present per 10(6) cells varied from less than 100 ng to approximately 600 ng . When these amounts of IgG were plotted against the Fc receptor activity of corresponding tumors, seven of the tumors were distributed along a line showing an inverse linear relationship; i.e . tumors with large amounts of IgG on their cell surfaces had the lowest Fc reactivity and vice versa . Cells from three of the tumors had lower amounts of IgG on their surface than expected from this relationship . However, the lack of correlation could be explained by the focal distribution of the Fc positive tissue within non-reactive tissue . The cells from these areas presumably carry less IgG on their surface and thereby reduce the quantity of IgG calculated per 10(6) cells . Prolonged washing of tumor sections resulted in stronger Fc receptor activity, and correspondingly washed cells had lower amount of IgG on their surface . Presumably the Fc receptor can bind IgG in vivo.

J Biol Chem, 1976 Apr 10, 251(7), 1864 - 70
Surface alterations in calf lymphocytes oxidized by sodium periodate; Presant CA et al.; In order to investigate alterations in surface structure in transformed lymphocytes, calf submandibular lymph node cell suspensions were oxidized with NaIO4 . Oxidezed lymphocytes were morphologically transformed and had higher rates of DNA synthesis by 2 days after treatment . These results were prevented by reduction of the cell suspension with NaBH4, or by neuraminidase treatment of cells prior to oxidation . The amount of 125I-labeled Agaricus bisporus lectin bound to cells immediately after oxidation and the affinity constant for binding were increased over 2-fold, while cells immediately following oxidation and reduction showed decreased receptors with still higher affinity for the lectin compared to untreated cells . The amount of Phaseolus vulgaris lectin bound to oxidezed cells was also increased, but affinity was unchanged . Immediately following oxidation and reduction, these receptor sites were unchanged in number and affinity from untreated cells . In contrast, the number and affinity of receptors for concanavalin A were not changed immediately after oxidation or oxidation and reduction . In order to define the extent of compositional changes in surface glycoprotein receptors, plasma membranes were isolated from frozen calf submandibular lymph nodes . Compared to untreated plasma membranes, oxidezed membranes had similar contents of galactose, mannose, N-acetylglucosamine, N-acetylgalactosamine, fucose, and amino acids . Sialic acid content of oxidized membranes was reduced when measured by thiobarbituric acid assay . Sialic acids of untreated plasma membranes co-chromatographed with N-glycolylneurominic acid and N-acetylneuraminic acid, while those of oxidized membranes co-chromatographed with N-glycolylneuraminic acid and 5-acetamido-3,5-dideoxy-L-arabino-7-aldehydo-2-heptulosonic acid . Therefore, specific surface conformational changes in certain classes of membrane glycoproteins are associated with mild Malapradian oxidation of membrane sialic acids . These temporally precede NaIO4-induced transformation of calf lymphocytes . This is consistent with an hypothesis of membrane-mediated stimulation of lymphocyte transformation.

Endocrinology, 1976 Apr, 98(4), 904 - 9
Lack of gonadotropic activity in the rabbit blastocyst prior to implantation; Holt JA et al.; Recent reports of an LH-like hormone in the rabbit preimplantation blastocyst and of elevated serum progesterone levels in the presence of unimplanted blastocysts prompted us to characterized further the biological activity of the presumed gonadotropin . Progesterone was measured by a highly specific radioimmunoassay in sera obtained from pregnant and pseudopregnant rabbits after mating (day 0) to fertile or vasectomized males . On days 3, 4, 5, and 6, which represent the preimplantation period, mean progesterone concentrations (ng/ml +/- SE) were 4.3 +/- 0.7, 5.1 +/- 0.5, 6.8 +/- 1.1, and 9.0 +/- 1.9 in 5 pseudopregnant rabbits and 4.1 +/- 0.4, 6.7 +/- 0.6, 5.9 +/- 0.9, and 7.0 +/- 0.8 in 7 pregnant rabbits . In a separate experiment, serum progesterone concentrations in 6 pseudopregnant and 8 pregnant rabbits were 10.1 +/- 0.7 ng/ml and 13.7 +/- 1.1 (P less than 0.02), respectively on days 11-12 . Thus, serum progesterone concentrations were not different in pregnant and pseudopregnant rabbits before the time of implantation (day 7), but were higher in pregnant rabbits after implantation . Blastocysts obtained on day 6 and incubated with a cell suspension of immature rat ovaries failed to stimulate the accumulation of progesterone in medium, in contrast to hCG, which was active even in the presence of blastocysts . Day-6 blastocysts also failed to stimulate the accumulation of testosterone from decapsulated rat testes and of progesterone from rabbit ovarian tissues in vitro . A gonadotropic effect of the conceptus can be observed in the rabbit within 4 to 5 days after implantation . However, we find no evidence for the existence of an LH-like hormone in the preimplantation blastocyst which stimulates the rabbit ovary to secrete progesterone.

J Immunol, 1976 Apr, 116(4), 1045 - 50
Synthesis of Gm allotypes by human tonsillar lymphocytes in culture: concordance with serum phenotype; Litwin SD et al.; Isolated human tonsillar lymphocytes were cultured with pokeweed mitogen, phytohemagglutinin, and without mitogen for 9 to 28 days . IgK, Gm(a) and Gm(f) were then quantitated in the cell suspensions . In cultures of cells derived from persons whose blood was heterozygous for IgGl allotype antigens Gm(a+f+), approximately equal amounts of Gm(a) and Gm(f) were found . In cultures of cells of Gma or Gmf homozygotes, there was complete concordance between the Gm allotype antigens produced by the cultures and the donor's serum phenotype-with no instance, either at zero time or at culture termination in which a Gm antigen was detected which was absent from the donor's serum . It was concluded that in vitro genetic allotype synthesis in tonsillar lymphocytes during short-term culture mirrored accurately in vivo Gm expression . IgK and Gm antigen synthesis was highest in the flasks containing pokeweed mitogen although both phytohemagglutinin and no-mitogen control flasks showed, in certain experiments, proliferation and an increase in the Ig per viable cell . It was observed that no-mitogen flasks contained twice as much allotype antigen as did phytohemagglutinin flasks suggesting an inhibition of Ig synthesis associated with the mitogen . The tonsillar lymphocytes, under the experimental conditions employed, were shown by a radio-incorporation and immunoprecipitation technique to be synthesizing polyclonal Ig de novo, at the termination of the cultures.

J Clin Invest, 1976 Apr, 57(4), 826 - 35
Human bone marrow lymphocytes . Cytotoxic effector cells in the bone marrow of normal individuals; Fauci AS et al.; This study was undertaken to determine the capability of lymphocytes in the bone marrow of normal individuals to mediate nonspecific killer cell functions in assays of phytohemagglutinin (PHA)-induced cellular cytotoxicity, and antibody-dependent cellular cytotoxicity (ADCC) against 51Cr-labeled chicken erythrocyte target cells . Relatively pure mononuclear cell suspensions were obtained from bone marrow aspirates in 30 normal volunteers by sucrose gradient centrifugations and from the peripheral blood of the same individuals by Hypaque-Ficoll density centrifugations . At an effector: target ratio of 10:1, the PHA-induced cellular cytotoxicity of peripheral blood was 78.8 +/- 1.3%, while that of bone marrow was not significantly less at 66 +/- 9% (P greater than 0.1) . At low effector:target ratios, the ADCC of bone marrow was negligible, while at higher effector:target ratios (20:1) bone marrow ADCC was 69 +/- 3.7%, which was comparable to that of peripheral blood . The lymphocytes themselves in the mononuclear cell suspensions of both peripheral blood and bone marrow were capable of cytotoxicity activity since depletion of monocytes from the suspensions by adherence to rayon wool and G-10 Sephadex columns did not remove the cytotoxic activity . Blocking of the Fc receptor on the effector cells by the addition of aggregated gamma globulin to the cultures suppressed the ADCC but not the PHA-induced cellular cytotoxicity of both peripheral blood and bone marrow, indicating that ADCC is dependent on an Fc receptor on the effector cell in both compartments . These studies demonstrate that the bone marrow of normal humans contains populations of lymphoid cells which have highly efficient killer cell capacities . It is uncertain what portion of these cells arise in the bone marrow and what portion enter the bone marrow parenchyma as part of the recirculating lymphocyte pool . These findings have relevance in the clearer understanding of the killer cell potential of grafted human marrow, as well as the bone marrow sequestration of functionally capable lymphocyte subpopulations in disease states and during chemotherapy.

Avian Dis, 1976 Apr-Jun, 20(2), 299 - 301
Application of a microtiter cell-culture method to characterization of avian adenoviruses; Grimes TM et al.; A microtiter cell-culture method was developed and used to titrate virus isolates for characterization . Virus dilutions and chicken kidney cell suspensions were dispensed into the wells of disposable microculture plates, with infectivity endpoints being determined microscopically on the fifth or sixth day, or by reading crystal-violet-stained monolayers on day 6 . With this method, 37 candidate avian adenoviruses isolated from diagnostic accessions were characterized as avian adenoviruses (AAV) . The criteria used for characterization were production of round-cell cytopathic effect, resistance to chloroform treatment, inhibition by 5-bromodeoxyuridine, and the presence of an antigen showing identity with a known AAV by precipitation in agar gel . Statistical anlaysis of eight replicate titrations of three AAV indicated that the titration method was highly reproducible . Use of the microculture method for titrations gave substantial savings in indicator cells, media, incubator space, culture dishes, and time.

Radiat Environ Biophys, 1976 Mar 30, 13(1), 19 - 26
Modifications of gamma-ray sensitivity of bacterial membrane by pre-exposure to light; Misiti-Dorello P et al.; The exposure of E.coli B/r cells to ultraviolet (UV) or to visible light prior to irradiation with gamma-rays modifies the sensitivity of the cell membrane to the radiation damage responsible for the loss of intracellular K+ content . The experiments reported in the paper have shown: 1 . exposure of bacterial cells to sublethal doses of UV light increases their sensitivity to gamma-ray-induced membrane damage, while exposure to visible light has the opposite effect; 2 . in combined exposures, the visible light, either given before or after the UV always produces a strong photoprotective effect . In either case, the photosensitizing effect of UV is completely suppressed; 3 . the photoprotection decays with time if cell suspensions are left in the dark before gamma-irradiation . At 0 degrees C, the half-life of the photoprotective effect is 25 min at pH 7 and 100 min at pH 7.5 . The decay is due to the presence of oxygen; 4 . the light band responsible for the induction of photoprotection has been estimated to lie in the wavelength region between 540 and 580 nm.

Z Krebsforsch Klin Onkol Cancer Res Clin Oncol, 1976 Mar 19, 85(3), 299 - 307
{In vitro assay for cyclophosphamide-sensitivity of human tumours: the effect of 4-hydro-peroxy-cyclophosphamide on the incorporation of 3H-uridine into the nucleic acids of human tumour cells (author's transl)}; Bastert G et al.; The utility of 4-hydro-peroxy-cyclophosphamide for testing the selectivity of human tumours cells against cyclophosphamide in vitro was studied . 4-hydro-peroxy-cyclophosphamide in aqueous solution spontaneously decomposes to 4-hydroxy-cyclophosphamide, the primary product of metabolic activation of cyclophosphamide thus representing a new form of "activated" cyclophosphamide . From 31 human tumours including 21 mammarian-, 4 ovarial-, 2 uterine-carcinomas, 2 seminomas, 1 hypernephroma and 1 rectum-carcinoma cell suspensions were made and the effect on the 3H-Uridine- and the 3H-Thymidine-incorporation into the nucleic acids after short time incubation with the effect of 4-hydro-peroxy-cyclophosphamide and 4-hydroxy-cyclophosphamide . 7 malignomas showed high sensitivity both against 4-hydro-peroxy-cyclophosphamide and against 4-hydroxy-cyclophosphamide . No additional inhibitory effect of the peroxyde function besides of that of the alkylating moiety of the molecule was found . Accordingly 4-hydro-peroxy-cyclophosphamide because of its better availibility and stability may be used as "activated" cyclophosphamide in screening tests for cyclophosphamide-sensivity of human tumours in vitro.

J Membr Biol, 1976 Mar 18, 26(2-3), 121 - 51
Regulation of ion permeabilities of isolated rat liver cells by external calcium concentration and temperature; Kolb HA et al.; Regulation of ion transport through the plasma membrane was studied on single cell suspensions of hepatocytes, obtained after perfusion of rat liver with collagenase/hyaluronidase solution . Steady-state intracellular K and Na contents were shown to be markedly dependent on external Ca concentration and temperature, the sum of both ion concentrations remaining nearly constant . In contrast, steady-state intracellular chloride content was found to be independent of external Ca concentration, but dependent on temperature . Using the constant field relations, the passive permeabilities PK and PCl for potassium and chloride, respectively, were derived from the experimental data . At temperatures at and above 37 degrees C, with increasing external Ca concentration, PK, exhibits a sharp decrease at about 10(-4)M . In contrast, PCl at 37 degrees C was found to be independent of Ca concentration within experimental error . Earth alkali ions other than Ca, show marked but different effects on PK if compared at equal concentrations . Preincubation of the cells with cholesterol leads to a broadening of the dependence of PK on external Ca concentration . The above results, as well as those on the dependence of PK on external Ca concentration obtained by other authors, could be quantitatively described by a theoretical model of the plasma membrane proposed earlier . This model postulates regulatory binding sites, which cooperatively undergo a cation exchange of divalent cations by K+ ions from the external medium if the cation composition of the latter is altered.

Eur J Biochem, 1976 Mar 16, 63(1), 303 - 11
Synthesis of albumin via a precursor protein in cell suspensions from rat liver; Edwards K et al.; The mechanism of the biosynthesis of albumin was studied in cell suspensions from rat liver . The cells were prepared by continuous perfusion of the liver in situ with 0.05% collagenase and 0.10% hyaluronidase and incubated under conditions optimized for the incorporation of amino acids into protein . Seven minutes after starting the incubation L-{1-14C}leucine was added, followed after 25 min by a 15 or 30-min chase with an 830-fold excess of non-radioactive L-leucine . Total protein, an albumin-like protein, and albumin were isolated from samples withdrawn immediately of total protein was found to remain constant after addition of the non-radioactive L-leucine, whereas that of the albumin-like protein decreased and that of albumin increased with incubation time . The increase in albumin radioactivity accounted for the decrease in radioactivity of the albumin-like protein, suggesting that the latter is a precursor of albumin . The precursor protein differed from albumin by an oligopeptide extension at the N-terminal end.

Eur J Biochem, 1976 Mar 16, 63(1), 137 - 45
Regulation of phenylalanine ammonia-lyase activity in cell-suspension cultures of Petroselinum hortense . Apparent rates of enzyme synthesis and degradation; Hahlbrock K; The time courses for induced changes in the phenylalanine ammonia-lyase activity at five different stages during the growth cycle of cell-suspension cultures from parsley (Petroselinum hortense Hoffm.) were investigated . Large increases in the enzyme activity, induced either by irradiation or by dilution of a cell culture into fresh medium, were followed by an expotential decline to the initial low level . The maximum inducible level of specific enzyme activity varied within a range of about six-fold, depending on the mode of induction and the growth stage of the cell culture.

J Lipid Res, 1976 Mar, 17(2), 190 - 2
Human fat cell sizing--a quick, simple method; Ashwell M et al.; Two methods were used to determine the mean cell diameters of 37 samples of human adipose tissue, obtained by open or needle biopsy . Method I was the sizing of cells in cell suspensions and Method II was a quick, simple method of sizing cells from fixed sections . The agreement between the two methods was good (r = 0.93, P = less than 0.001) . The results using Method II were slightly lower than those using Method I, and a correction factor is suggested . Method II has several advantages over Method I and we propose that it is a suitable method for sizing cells when a quick method with a permanent record is required.

Br J Dermatol, 1976 Mar, 94(3), 243 - 252
Incorporation of I-14C-acetate into the lipids of isolated epidermal cells; Long VJ; Suspensions of epidermal cells were prepared by trypsinization of rat epidermis and incubated with I-14C-acetate in Eagle's minimum essential medium . The incorporation of radioactivity into the total lipids of the cells was increased by the addition of serum to the medium . The pattern of incorporation into the main lipid classes was affected by the addition of serum to the medium and by alterations in the density of the cell suspensions . The incorporation of radioactivity into the total lipids increased approximately linearly over a 24-h period of incubation and the pattern of incorporation into the phospholipids and glycolipids altered with time . However, at each time interval studied, reporducible patterns of incorporation were obtained under controlled conditions . The incorporation of radioactive acetate therefore provides the basis for a very sensitive method of lipid analysis.

Endocrinol Exp, 1976 Mar, 10(1), 23 - 8
Further studies on response of blood thyroid hormone level to its acute depletion by isovolemic exchange transfusion; Langer P et al.; Groups of rats weighing about 400 g and fed low iodine diet for 16 days were injected with 125I- daily from day 8 to 14 . Two days later their blood thyroid hormone was acutely depleted with an isovolemic exchange transfusion of hormone-free blood cell suspension . Relative changes of total plasma radioactivity and iodinated compounds were measured at frequent intervals, maintaining isovolemia of the recipient animal . In normal animals a post-transfusion decrease of total plasma radioactivity was related to the degree of exchange of total blood volume as was the post-transfusion increase to the initial level . No post-transfusion increase of total plasma radioactivity or labeled thyroxine was found in thyreidectomized animals . On the other hand, in normal animals a post-transfusion increase of plasma labelled thyroxine was observed . A linear increase of labeled iodide in plasma was found in both normal and thyroidectomized rats, the mechanism of which in thyroidectomized animals may be explained by a reflux of iodide from peripheral tissues to the blood . In normal animals a TSH-induced release of iodide from thyroid due to TSH action may participate in this phenomenon.

J Cell Biol, 1976 Mar, 68(3), 451 - 61
Freeze-fracture studies of the thecal membranes of Gonyaulax polyedra: circadian changes in the particles of one membrane face; Sweeney BM; Intramembrane faces were visualized in the marine dinoflagellate Gonyaulax polyedra by the freeze-fracture technique, in order to test a prediction of a membrane model for circadian oscillations--i.e;, that membrane particle distribution and size change with time in the circadian cycle . Cells from each of four cell suspensions in continuous light (500 1x, 20-21 degrees C) were frozen, without fixation or cryoprotection, at four circadian times in a cycle . This paper reports findings concerning the membranes associated with the theca, particularly the cytoplasmic membrane and the membrane of the large peripheral vesicle . While the number and size distribution of the particles of the PF face of the cytoplasmic membrane were constant with time, those of the EF face of the peripheral vesicle doubled in number at 18 h circadian time as compared with 06 h . Particles of the 120-A size class, in particular, were more numerous at 12 and 18 h circadian time than at 00 and 06 h . While the finding does not provide definitive confirmation of the membrane hypothesis for circadian rhythms, it is consistent with this model . It is suggested that the peripheral vesicle may be the site of bioluminescence in Gonyaulax.

J Cell Biol, 1976 Mar, 68(3), 799 - 802
Ectogalactosyltransferase studies in fibroblasts and concanavalin A-stimulated lymphocytes; Patt LM et al.; In this communication, we have demonstrated that hydrolysis of the nucleotide sugar can cause errors in the detection of an ectoglycosyltransferase . Spleen cell suspensions can incorporate radioactivity when incubated with labeled UDP-galactose, but all the activity is due to decomposition of the nucleotide sugar and uptake of the free sugar . The fibroblast cell lines can incroporate carbohydrate directly from UDP-galactose . Several criteria are presented with can be used to demonstrate that a nucleotide sugar is the direct carbohydrate donor.

Hoppe Seylers Z Physiol Chem, 1976 Mar, 357(3), 359 - 75
Autoregulatory shift from fructolysis to lactate gluconeogenisis in rat hepatocyte suspensions . The problem of metabolic zonation of liver parenchyma; Katz N et al.; Hepatocytes were isolated from fed rats with glucose and insulin and freom fasted rats with glucagon in all media in an attempt to obtain cells which might be fixed preferentially in either the glycolytic or gluconeogenic state . When tested enzymatically, both "fed" and fasted" cells catalyzed glucose formation from lactate (gluconeogenesis) and lactate formation from fructose (fructolysis); lactate formation from glucose may have occurred in "fed" cells . Thus it was impossible, at least in the C3 part of the metabolic pathways between triosephosphate and pyruvate, to fix the hepatocytes in either metabolic state . The shift from glycolysis to gluconeogenesis could be investigated for the C3 part in "fasted" cells with fructose as the glycolytic and lactate as the gluconeogenic substrate . Lactate was first formed from fructose and later reutilized to a large extent . This reconsumption was blocked by the gluconeogenesis inhibitor quinolinate, both when tested enzymatically and radiochemically . Thus fructolysis was shifted to lactate gluconeogenesis . This shift at the assumed phosphoenolpyruvate/pyruvate cycle was autoregulatory, i.e . dependent on substrates and independent of circulating horomes . Maximal velocities and half saturating concentrations were determined for fructose and for lactate as substrates . The kinetic data obtained, especially the sigmoidal pattern of fructolysis, could nicely explain phenomenologically the rather sudden slow-down of lactate production and the shift to lactate consumption . The levels of the metabolites ATP, ADP, AMP, fructose bisphosphate and alanine, which control the enzymes of the assumed phosphoenolypyruvate/pyruvate cycle, were determined in the cytosol and in the mitochondria before and after the shift from fructose glycolysis to lactate gluconeogenesis . The changes observed could not explain the shift . Experiments with {14C} fructose plus unlabelled lactate and reciprocally, with unlabelled fructose plus {14C} lactate, clearly reveled that within the C3 part, glycolysis and gluconeogenesis were catalyzed simultaneously . The simultaneity of and the shift between fructolysis and gluconeogenesis by the liver cell suspension can best be explained by assuming two metabolically different types of hepatocytes rather than one type of hepatocyte with metabolically equal or different cell compartment . In vivo, the different types of hepatocytes would form a gluconeogenic and a glycolytic zone within the liver parenchyma . Since, under normal conditions, the size of these metabolic zones should remain unaltered, the shift from net glycolysis to net gluconeogenesis would be dependent primarily on substrate concentrations (autoregulation).

J Clin Invest, 1976 Mar, 57(3), 633 - 40
Comparative properties of the Charcot-Leyden crystal protein and the major basic protein from human eosinophils; Gleich GJ et al.; Guinea pig eosinophil granules contain a protein, the major basic protein (MBP), which accounts for more than half of the total granule protein, has a high content of arginine, and displays a remarkable tendency to form disulfide-linked aggregates . In this study we have purified a similar protein from human eosinophil granules and have compared the human MBP to the protein comprising the Charcot-Leyden crystal (CLC) . Eosinophils from patients with various diseases were purified and disrupted, and the granule fraction was obtained . Examination of the granule fraction by transmission electron microscopy showed numerous typical eosinophil granules . Analyses of granule lysates by gel filtration and by polyacrylamide gel electrophoresis revealed the presence of peroxidase and MBP with properties similar to that previously found in guinea pig eosinophil granules . The human MBP had a molecular weight of 9,200, contained less than 1% carbohydrate, was rich in arginine, and readily formed disulfide-bonded aggregates . CLC were prepared from eosinophil-rich cell suspensions by homogenization in hypotonic saline . The supernates following centrifugation of cell debris spontaneously formed CLC . Analysis of CLC revealed the presence of a protein with a molecular weight of 13,000 containing 1.2% carbohydrate . The protein displayed a remarkable tendency to aggregate even in the presence of 0.2 M acetic acid . Human MBP and CLC protein differed in their molecular weights, carbohydrate compositions, and amino acid analyses . Mixtures of the MBP and the CLC protein yielded two bands in polyacrylamide gel electrophoresis . Neither eosinophil protein increased vascular permeability in the guinea pig skin or contracted the guinea pig ileum . The results indicate that the human MBP and the CLC are distinct substances with properties such that one cannot be derived from the other.

Endocrinol Exp, 1976 Mar, 10(1), 29 - 36
Altered response of blood thyroxine level after its acute depletion by isovolemic exchange transfusion in rats with lesions in hypothalamus and thalamus; Langer P et al.; Bilateral electrolytic lesions were made in various areas of hypothalamus or thalamus on the 6th day of a period of daily radioiodide injections (1 or 5 muCi125I-daily per animal) in male rats weighing about 350 g . Such injections were continued for another 4 days and after 2 days of intermission the blood thyroid hormone was acutely depleted by isovolemic exchange transfusion of thyroid hormone free blood cell suspension . Relative changes of plasma thyroxine level were measured with the aid of paper chromatography in small aliquots of plasma frequently taken from the animals under maintaining isovolemia by replacing the removed plasma . It was found that in animals with various bilateral electrolytic lesions in hypothalamus (suprachiasmatic and paraventricular areas) the response of blood thyroxine level after the transfusion is similar as in sham-operated controls bearing unilateral subcortical lesion or in normal animals observed previously . On the other hand, the response in animals with thalamic lesions was repeatedly found to resemble that observed previously in thyroidectomized animals . Since the response of blood thyroxine level presumably results from changes of pituitary thyrotropic activity, it is concluded that in rats with thalamic lesions the normal response of hypothalamo-pituitary-thyroid axis was prevented . The mechanism of this action, however, remains to be elucidated.

Z Immunitatsforsch Exp Klin Immunol, 1976 Mar, 151(1-2), 13 - 21
Effect of cyclophosphamide on the immune response to sheep erythrocytes in the mouse . II . A study of enzyme activities in the draining lymph node; Mackiewicz S et al.; Young adult CFW mice, injected with sheep erythrocytes, were treated with cyclophosphamide and sacrificed at different times . The activity of acid phosphatase and for non-specific esterase was measured by semi-quantitative methods in smears prepared from cell suspension of draining lymph node . In cyclophosphamide-treated mice was noted a significant decrease in acid phosphatase activity in lymphoid cells, expressed both as average activity in single lymphoid cell and a decrease in proportion of cells exhibiting enzyme activity . Also a short-term decrease was observed in activity of non-specific esterase caused both by disappearance of highly active large lymphoid and blast cells as well as decrease in percentage of enzyme-positive small lymphocytes.

Rev Fr Transfus Immunohematol, 1976 Mar, 19(1), 55 - 65
{Heterogeneity of the cellular distribution of erythrocytic A antigens . Ultramicroscopic study}; Gourdin MF et al.; A and A1 antigens have been detected on cells of the human erythrocyte series by immunoelectron microscopy . These antigens have been revealed by an indirect method involving various anti-A and anti-A1 antibodies (allo, auto, hetero-antibodies) and peroxidase-conjugated anti-immunoglobulin antibodies . Immunologic labelling has been carried out with erythrocyte or bone marrow cell suspensions which were fixed prior to incubation with reagents . Cells from various A phenotypes were examined . A and A1 antigens were visualized on maturing normoblasts, at every developmental stage . In addition cell to cell variations of the surface labelling of erythrocytes was found in normal phenotypes, suggesting the existence of several populations of cells according to antigenic load.

Biotechnol Bioeng, 1976 Feb, 18(2), 217 - 37
Conversion of L-sorbose to L-sorbosone by immobilized cells of Gluconobacter melanogenus IFO 3293; Martin CK et al.; Gluconobacter melanogenus IFO 3293 cells capable of converting L-sorbose to L-sorbosone were immobilized in polyacrylamide gel . The preferred polymer composition for high activity and stability was determined to contain a total monomer concentration of 7.2% and 16.6% crosslinking agent . No significant differences in optimal conditions for conversion, e.g., pH and temperature, were found in comparison with free cell suspensions . However, in the absence of L-sorbose, the thermal stability of immobilized cells was lower . After the initial loss, the conversion activity of immobilized cells increased, possibly due to lysis, and this increase was related to the polymerization conditions and the incubation temperature for the L-sorbose conversion . The enzymatic activity and stability of the immobilized cells also depended on the physical form of the gel and the aeration levels . Addition of electron acceptors or addition of L-sorbosone to the medium reduced, while addition of neomycin, ampicillin, chloramphenicol, and tetracycline increased the stability of the enzymatic activity.

Gastroenterology, 1976 Feb, 70(2), 177 - 80
Isolation and kinetic characteristics of mucosal lymphocytes in Crohn's Disease; Clancy R; Single cell suspensions of lymphocytes have been prepared from human gut mucosa, and short-term culture used to characterize the kinetics of DNA synthesis of mucosal lymphocytes . High rates of DNA synthesis were found in 72-hr cultures of Crohn's disease mucosal lymphocytes, compared with normal subjects . These high rates correlated with the appearance of numerous transformed blast cells in terminated cultures . Lymphocytes from normal and abnormal human gut mucosa were stimulated by phytohemagglutinin-P, except in some patients with Crohn's disease with high rates of "spontaneous" DNA synthesis . The isolation and culture of human gut mucosal lymphocytes by a simple preparative technique will enable the direct study of lymphocyte function in both normal and diseased gut mucosa.

Can J Microbiol, 1976 Feb, 22(2), 159 - 64
Products of anaerobic phloroglucinol degradation by Coprococcus sp . Pe15; Tsai CG et al.; Under anaerobic conditions, resting cell suspensions of Coprococcus sp . Pe15 degraded 1 molecule of phloroglucinol to 2 molecules of acetic acid and 2 molecules of carbon dioxide . The organism metabolized the flavonoids rhamnetin and quercetin anaerobically in 20% rumen fluid medium but failed to grow under similar conditions at the expense of any of 39 other aromatic or flavonoid compounds tested.

Br J Radiol, 1976 Feb, 49(578), 166 - 71
Response of HeLa cells to irradiation with pi- mesons; Mill AJ et al.; HeLa cell suspensions were irradiated at various depths of Perspex in a beam of 70 MeV pi- mesons . The dose-rate in the Bragg peak varied between 40 rad hour-1 and 150 rad hour-1 . The cells were assayed in vitro for loss of reproductive integrity . The results for irradiation in the peak indicated an RBE of about 2-1 when compared to the response obtained using 60Co gamma-rays at comparable dose-rates . At dose-rates of 100-150 rad hour-1, the RBE peak-to-plateau was about 1-4, while at lower dose-rates, the RBE peak-to-plateau was about 1.

Agents Actions, 1976 Feb, 6(1-3), 326 - 39
Studies on the regulation of the neutrophil chemotactic response using a rapid and reliable method for measuring random migration and chemotaxis of neutrophil granulocytes; Keller HU et al.; An economic and sensitive test system for measuring random and directional migration of human neutrophils is described . The technique, based on a modified Boyden chamber equipped with a two-filter system, permits a substantial reduction of both incubation time and sample volume . The influence of various technical factors such as the neutrophil concentration in the cell suspension, the incubation time of the chambers, the test concentration of activated plasma or serum, the presence of heparin, and the procedure for separating neutrophils from human peripheral blood, was investigated . Standardized procedures for measuring and reporting neutrophil chemotaxis are proposed . The method has been used to study the significance of factors regulating neutrophil migration such as cytotaxin inactivators and neutrophil immobilizing factors (NIF) . Activity of cytotaxin inactivators as assessed in undiluted serum or plasma at pH 7.4, 6.0 or 4.0 was very low . In contrast, potent neutrophil immobilizing activity was found in human serum or diluted plasma . These factors which inhibit migration were accordingly termed neutrophil immobilizing factors of plasma (NIF-P) and neutrophil immobilizing factor of serum (NIF-S) . These factors are heat-stable, non-dialysable and of high molecular weight.

Immunology, 1976 Feb, 30(2), 189 - 202
Single cell studies on the antibody-forming potential of fractionated, hapten-specific B lymphocytes; Nossal GJ et al.; This study addresses itself to the problem of antibody formation in vitro by mouse splenic B lymphocytes enriched for reactivity to the hapten NIP by the hapten-gelatine binding and melting technique of Haas and Layton (1975) . Small numbers of NIP-gelatine-bound B cells were placed in microcultures either by bulk dispensing of dilute cell suspensions, or by micromanipulation under direct microscopic visualization . Antibody formation was induced by the T cell-independent hapten-protein conjugate NIP-polymierized flagellin, using 10(4) thymus cells per microlitre as 'filler' cells . The frequency of precursors of NIP-specific antibody-forming cells among bound cells was about 2-2 X 10(-2) (one cell in forty-five) by both statistical and direct evaluation, after adjustment for a background frequency of 6-10 X 10(-8) precursors in the thymus filler cells . Single clones commenced antibody secretion asynchronously, as shown by the fact that the incidence of positive cultures continued to rise over the whole three days of culture, and that very small clones of one to four plaque-forming cells (PFC) were still found on day 3 . The mean PFC number per positive culture rose from 1-2 at day 1 to 4-7 at day 2 and about 20 at day 3.

Acta Physiol Scand, 1976 Feb, 96(2), 170 - 9
Cyclic AMP-dependent and independent inhibition of lipolysis by adenosine and decreased pH; Hjemdahl P et al.; NA-stimulated lipolysis and cAMP formation in isolated rat fat cells is inhibited by acidosis . In the present report we have examined the quantitative relationship between lipolysis and cAMP formation at normal and reduced pH and the possible involvement of adenosine, an endogenous inhibitor of cAMP formation . Adenosine antagonized cAMP accumulation and to a considerably lower degree lipolysis, effects potentiated by acidosis . Theophylline, an antagonist of adenosine effects, stimulated lipolysis and cAMP-accumulation, and potentiated responses to NA . Adenosine deaminase (ADA) had theophylline-like effects . Acidosis inhibited lipolysis and cAMP accumulation induced by ADA and theophylline to a larger extent than those induced by NA . It is suggested that adenosine modulates fat cell cAMP production and may contribute to the antilipolytic effect of acidosis . There was a curvilinear relationship between cAMP elevation and glycerol production in fat cell suspensions, which was different at pH 7.4 and at pH 6.6 . The amount of cAMP needed for half-maximal activation of lipolysis increased from 1.3 (pH 7.4) to 3.1 pMol X 10(-5) cells (pH 6.6) . The maximal glycerol production was reduced from 1 300 to 900 nMol X 10(-5) cells . The antilipolytic effect of acidosis is apparently due partly to an inhibition of cAMP formation and partly to inhibition of subsequent step(s) in the activation sequence.

Eur J Biochem, 1976 Jan 2, 61(1), 199 - 206
Coordinated induction and subsequent activity changes of two groups of metabolically interrelated enzymes . Light-induced synthesis of flavonoid glycosides in cell suspension cultures of Petroselinum hortense; Hahlbrock K et al.; The enzymes of the flavonoid glycoside pathway were specifically induced upon irradiation of a 10-day-old, dark-grown cell suspension culture of Petroselinum hortense Hoffm . with ultraviolet light . The curves for the activity changes of a first sequence of three enzymes (group I) revealed only small, but significant, differences . Sharp peaks in these enzyme activities were observed at about 17, 22, and 23 h after the onset of the irradiation . The apparent half-lives during the subsequent periods of decline ranged, in the same order, from about 10 to 15 and 17 h . No significant differences were found for the lag periods preceding the increases in the three enzyme activities . The possibility is discussed that the slight differences in the patterns of the light-induced activity changes are mainly due to different rates of degradation of the enzymes, suggesting an otherwise largely interpendent regulation . The patterns of the activity changes of four enzymes of the second sequence (group II) differed greatly from those observed for group I, but were again similar to one another . Thus, the two groups of enzymes appear to be regulated differently, despite their concomitant induction . A sigmoidal curve for the accumulation of the flavonoid glycosides was obtained upon the induction of the enzymes . This curve corresponded closely to that derived by integration of the curve for the activity changes of the first enzyme of group I, phenylalanine ammonia-lyase . It is concluded that this enzyme might be rate-limiting for the entire pathway.

Arch Invest Med (Mex), 1976, 7(1), 1 - 8
{Antibodies in venereal sarcoma in dogs}; Gomez-Estrada H et al.; Neoplastic cell suspensions prepared from fourteen spontaneous and three transplanted vereal sarcomas of the dog were studied by microcytotoxicity and immunofluorescence tests . Serum and cell-surface antibodies were found in all cases . These antibodies were not capable of activating canine complement . Most likely these antibodies are not cytotoxic in vivo, but rather act by enhancing tumor growth.

J Histochem Cytochem, 1976 Jan, 24(1), 11 - 5
The use of a slide spinner in the analysis of cell dispersion; Wolley RC et al.; A simple and reliable method of determining the degree of dispersion of a cell suspension has been developed using the Perkin-Elmer Uni-Smear Spinner . Optimum conditions regarding rate and duration of spin, etc., were first ascertained using dispersed cell cultures including human cervical cancer cells as well as gynecologic samples . After spinning, single cells in suspension appeared as isolated cells on the slides . Cell aggregates, on the other hand, remained together . Therefore, the distribution of cells in various sized aggregates could be easily quantitated and the slides retained for future review . This method was used to evaluate the dispersing effects of trypsin, ethylenediaminetetraacetate and and syringing human on human gynecology samples obtained by routine cervical scrapes . None of the dispersion methods has, so far, produced an adequate monodispersed cell suspension without unacceptable cell loss.

Br J Cancer, 1976 Jan, 33(1), 36 - 50
Studies on the Fc receptor bearing cells in a transplanted methylcholanthrene induced mouse fibrosarcoma; Szymaniec S et al.; The presence of Fc receptors on the surface of cell suspensions obtained from a transplanted isogeneic methylcholanthrene induced murine fibrosarcoma has been investigated by determining the capacity of such cells to form rosettes with antibody coated SRBC . These studies indicate that a large percentage of cells in the tumour had Fc receptors on their surface . The proportion of such cells was increased by reducing the number of cells transplanted, by administering cyclophosphamide to the host, and on occasions by the i.p . injection of C . parvum . It was largely unaffected by the route of tumour cell transplantation or by T cell depletion of the host before transplantation but appeared to decline in older (i.e . larger) tumours . Both phagocytic and non-phagocytic cells had Fc receptors on their surface . The phagocytic population appeared to be affected most by procedures which altered the overall percentage of Fc receptor bearing cells . The Fc receptor bearing tumour cells were separated from those devoid of Fc receptors on the basis of their adherent properties . Upon transplantation to isogeneic hosts both populations gave rise to tumours containing a high percentage of Fc receptor bearing cells . These studies suggest that many of the Fc receptor bearing cells in our tumour are probably infiltrating cells of host origin . Their significance in relation to tumour growth remains to be established.

Arthritis Rheum, 1976 Jan-Feb, 19(1), 73 - 8
Reduction of phagocytosis and lysosomal enzyme release from human leukocytes by serum from patients with systemic lupus erythematosus; Zurier RB; Serums from 22 of 30 (73.3%) patients with systemic lupus erythematosus (SLE) interfered significantly with particle (zymosan) uptake and subsequent release from normal human neutrophils of lysosomal enzymes . SLE serums with low as well as those with normal functional hemolytic complement activity (CH50) suppressed phagocytosis and enzyme release despite the presence of normal serum in cell suspensions . The defect did not appear to be caused by anticomplementary activity of serum . Serums from patients whose clinical activity of disease varied from none to severe and whose treatment varied from none to high doses of prednisone were capable of suppressing phagocytosis and enzyme release . The severity of clinical SLE activity did not affect the degree of suppression . Serums from patients treated with corticosteroids were more inhibitory than serums from patients not so treated . The nature of the inhibitor is unknown.

Vox Sang, 1976, 30(2), 144 - 8
Capillary tube testing and enhancement with 30% Albumin; Crawford MN et al.; Capillary tube methods are reviewed and modifications with albumin are described with emphasis on detection of antigens in the major red cell systems and in HL-A and related systems using red cell suspension.

Immunology, 1976 Jan, 30(1), 117 - 21
Antibody-dependent cell-mediated cytotoxicity in the rat . The role of macrophages; Sanderson CJ et al.; Experiments are described in which the inactivation of macrophage activity by quartz particles is used to investigate the role of macrophages in antibody-dependent cell-mediated cytotoxicity in the rat . The results confirm previous findings which indicated that macrophages play no significant role in assays using cell line cells as targets . On the other hand, previous suggestions that macrophages are active against antibody-coated chick erythrocytes cannot be substantiated . In fact, it is shown that macrophages can play a protective role, and that inhibiting macrophage activity in peritoneal exudates leads to a spectacular increase in antibody-dependent lysis of chick erythrocytes . It is suggested that the confusion surrounding the role of macrophages in this assay has resulted from the failure to recognize that adherence techniques such as carbonyl-iron treatment of cell suspensions can result in substantial depletion of non-phagocytic adherent cells.

Cancer Res, 1976 Jan, 36(1), 33 - 6
Effect of N1-(2'-tetrahydrofuryl)-5-fluorouracil and 5-fluorouracil on nucleic acid and protein biosyntheses in Ehrlich ascites cells; Fujimoto S et al.; N1-(2'-Tetrahydrofuryl)-5-fluorouracil (FT-207) is a derivative of 5-fluorouracil (5-FU) and has been accepted as a new chemotherapeutic drug . The inhibitory effects of FT-207 and 5-FU on nucleic acid and protein biosyntheses in Ehrlich ascites cells were compared . Both drugs markedly inhibited the incorporation in vivo of the labeled precursors into nucleic acid and protein . The inhibitory effect of FT-207 on DNA and RNA synthesis lasted for a long period of time . Two hr after administration of 5-FU (250 mug/g body weight), the absolute size of uracil pool of liver increased by at least 50% . However, in an in vitro study, FT-207 at a concentration of 60 mug/ml produced no effect on the incorporation of precursors into DNA and RNA of Ehrlich ascites cells 3 hr incubation . If 5-FU was added to Ehrlich ascites cell suspension simultaneously with {5-3H}uridine, the incorporation of the labeled precursor into RNA increased by 30 to 50%.

Cancer Res, 1976 Jan, 36(1), 28 - 32
Tumor colony formation by Friend virus-infected cells in immunosuppressed mice; Axeirad AA et al.; We have investigated the role of host immunological factors in the formation of "tumor colonies" in the spleens of unirradiated C57BL/6 X C3Hf/Bi FI mice 9 days after i.v . injection of spleen cells from Friend virus (FV)-infected C3Hf/Bi donors . Pretreatment of hosts with antilymphocyte serum (ATS) increased the number of tumor colonies . Pretreatment with formalinized FV-infected cells had the opposite effect, and ATS diminished the inhibitory effect of preimmunization . Cell suspensions from 11 individual FV-infected donors were examined . The suspensions differed with respect to their behavior on transplantation into untreated and ATS-pretreated F1 hybrid hosts . With several suspensions, the number of tumor colonies produced was approximately proportional to the number of cells injected; in all of these, ATS increased the slope of the line relating colony number to cell number . With most of the suspensions, tumor colony-forming efficiencies in untreated hosts strikingly decreased with increasing number of cells injected; ATS induced an increase in the number of tumor colonies and rendered the colony-forming response more nearly proportional to cell number . With two suspensions, few or no colonies developed; pretreatment with ATS had no significant effect . When the 11 cell suspensions were considered together, a proportional relation was found between the magnitude of the ATS effect (i.e., colony number in the presence of ATS minus colony number in the absence of ATS) and the colony-forming efficiency in ATS-treated mice . The ATS effect on the average was equivalent to a 2-fold increase in tumor colony-forming efficiency . We interpret these findings to indicate that two factors interact to determine the number of tumor colonies produced by spleen cells from FV-infected C3H donors in untreated F1 hybrid hosts . One is a property of the FV-infected cell population and includes its frequency of tumor colony-forming units; this factor varies widely among different cell suspensions . The other is a property of the tumor colony-forming units-host interrelationship and includes the vulnerability of tumor colony-forming units to the host immune response elicited by the injected cells; this factor appears to be constant with different cell suspensions . The present results show that the two factors can be dissociated in immunosuppressed hosts.

In Vitro, 1976 Jan, 12(1), 65 - 73
Culture of cells in beem capsules: a new technique for electron microscopic study of monolayer cultures; Eppig JJ et al.; A method is described for the monolayer cultivation of primary cell suspensions and established cell lines directly in carbon-coated BEEM capsules, BEEM capsules are routinely employed by electron microscopists in tissue embedding procedures; growing monolayer cultures directly on the lids of inverted BEEM capsules presents the obvious advantage of maintaining cell to cell and cell to substratum conthaets with a minimum of stress and damage in the preparative steps for electron microscopy.

Int Arch Allergy Appl Immunol, 1976, 50(1), 129 - 32
Antiserum specific for reticulin of the bursa of fabricius; Boyd RL et al.; Antiserum produced by immunizing rabbits with embryonic chicken spleen cells showed, after appropriate absorption with cell suspensions, specificity for fetal spleen cells in membrane immunofluorescence tests . However, when the original antiserum was absorbed with tissue homogenates and tested on cryostat tissue sections, it reacted specifically with the reticular framework which separates the cortical and medullary lymphocytes in the follicles of the adult bursa of Fabricius . It is suggested that the reticulin may influence bursal lymphoid differentiation.

Int Arch Allergy Appl Immunol, 1976, 52(1-4), 79 - 94
Studies on immune responses to parasite antigens in mice . II . Aspects of the T cell dependence of circulating reagin production to Ascaris suum antigens; Mitchell GF; Heat-labile, rat skin-fixing antibodies were detected readily in the sera of young female mice dosed intranasally with the body fluid of Ascaris suum (ABF) and the adjuvant, Bordetella pertussis vaccine (BPV) . In addition, washed cell suspensions prepared from spleen and the lymph nodes regional to the lungs were positive in an adoptive cutaneous anaphylaxis assay, an assay which may detect activities of reagins associated with mast cells rather than reaginic antibody-secreting cells . The intraperitoneal route was a poor means of inducing circulating anti-ABF reagins and an intraperitoneal injection of ABF + BPV delayed the appearance of circulating reagins in mice dosed at the same time with ABF + BPV intranasally . Hypothymic female BALB/c . nu/nu ('nude') mice failed to produce circulating reagins to ABF but an injection of normal thymocytes or cortisone-resistant thymocytes from syngeneic female mice led to higher titers of circulating reagins than found in normal female BALB/c . nu/+ littermates . Using cells from young male or female syngeneic donors and male and female BALB/c . nu/mu recpiients, evidence was obtained for a defect in the thymus of young male mice and conceivably this defect may extend to the peripheral T cell population in such mice . Cyclophosphamide pretreatment or adrenalectomy increased circulating reagin titers in normal mice dosed intranasally with ABF + BPV, and pretreatment with lipopolysaccharide intranasally markedly reduced titers of circulating anti-ABF reagins . In the discussion, emphasis is given to the hypothesis that potent allergens are T cell-stimulating, relatively persistent antigens which, when located in submucosal lymphoid sites and under conditions of limited antibody production as a result of limited recruitment of 'helper' T cells systemically, lead to the induction and sustained production of IgE by resident Bxi cells and their progeny.

Int Arch Allergy Appl Immunol, 1976, 52(1-4), 347 - 54
Characterization of K-cell activity by use of depletion experiments; Kraft D et al.; Normal human blood lymphocytes with affinity for ox red cells sensitized with IgG antibody, for normal or papain-treated sheep red cells and for ox red cells coated with mouse complement were used for rosette formation and the rosetting cells separated by density gradient centrifugation on Ficoll/hypaque . The non-rosetting cells at the interface were collected and compared with cell suspensions before treatment for direct and antibody-dependent cytotoxicity of human target cells . Depletion of Fc-receptor-bearing lymphocytes strongly decreased antibody-dependent cell-mediated cytotoxicity; reduction in the number (or depletion) of T cells and cells with C'3 receptor had no effect, showing the same or enhanced K-cell activity . It is concluded that one type of K or killer cell has Fc receptors but lacks C'3 receptors.

J Immunol Methods, 1976, 12(1-2), 125 - 30
Fractionation of cytotoxic cells from tumour-immune rats on derivatized collagen gels; Maoz A et al.; Incubation at 37 degrees C of spleen cells from rats, immunized with Gross virus-induced lymphoma, on collagen gels coated with membrane extracts of lymphoma cells yielded two different cell populations . The non-adherent cells showed greatly diminished cytotocicity for lymphoma cells compared with unfractionated spleen cell suspensions, whilst the specifically adherent cells which were recovered after collagenase digestion of the gels, showed enrichment of cytotoxic activity.

Scand J Immunol, 1976, 5(5), 487 - 95
Binding of IgM by human T lymphocytes; Gmelig-Meyling F et al.; Ox erythrocytes, sensitized with IgM-type rabbit antibodies, were found to form rosettes with human blood lymphocytes . Granulocytes, monocytes, and macrophages appeared to lack this property . The rosette formation could be inhibited with human IgM and its Fc fragments . IgM-binding lymphocytes were also present in cell suspensions isolated from human tonsils and thymuses and among blood lymphocytes cultured in vitro . The outcome of combined marker tests and cell separation experiments disclosed that the rosetting lymphocytes belong to the T-lymphocyte population.

Scand J Immunol, 1976, 5(5), 467 - 77
Modification of the response of human T lymphocytes to phytomitogens by cocultivation with unresponsive non-T leukocytes; Blomgren H; Experiments were conducted to ascertain to what extent the mitogen response of human peripheral T cells is influenced by contaminated, nonresponding leukocytes . T- and B-lymphocyte preparations, extensively depleted of monocytes, exhibited extremely poor responses to pokeweed mitogen and concanavalin A compared with the original unfractionated cell population . A strongly reduced phytohemagglutinin response was noted in the B-cell but not in the T-cell fraction . Mixtures of cell preparations enriched in T or B cells yielded stimulations higher than expected . Mitomycin-C-treated T-cell preparations mixed with untreated preparations enriched in B cells gave slightly higher responses than expected . However, highly enhanced responses were observed when untreated T cells were mixed with mitomycin-treated cell suspensions enriched in B cells . A similar enhancing effect was noted when mitomycin-treated cell suspensions enriched in adherent cells were added . It is concluded that the mitogen reactivity of T cells, on a cell-for-cell basis, may be enhanced tenfold or more by cocultivation with unresponsive non-T leukocytes . A reduced mitogen reactivity of peripheral lymphoid cells from patients with various types of disease may thus either reflect a decreased proportion of responsive lymphocytes or unresponsive non-T lymphocytes capable of enhancing mitogen reactivity, or both.

Scand J Immunol, 1976, 5(3), 233 - 42
Antibody-dependent cell cytoxicity (ADCC) . Characterization of 'killer' cells in human lymphoid organs; Cordier G et al.; The effector cell(s) in human antibody-dependent cell cytotoxicity (ADCC), with antibody-coated chickens erythrocytes as targets, was studied by comparison of cell suspensions from various lymphoid organs and by means of various cell fractionation methods . Effector cells (K) were found mostly in peripheral blood, spleen, and bone marrow but not in tonsils, lymph nodes, and thymus . Effector cells bear Fc receptors and can form EA rosettes with the antibody-coated target cells . About 1,5% peripheral blood lymphocytes can form 'high-avidity' EA rosettes with targets coated at low antiserum concentration . Most of the effector cells belong to this small subset, as shown by experiments of selective depletion . Removal of most monocytes, T cells, or B cells from, or addition of T-cell-specific antiserum to, the effector cell suspensions did not affect ADCC . Effector cells in this model of ADCC therefore lack the conventional B- or T-cell markers but at least some of them are likely to bear C3 receptors.

Scand J Immunol, 1976, 5(3), 221 - 31
Distribution of cells binding erythrocyte-antibody (EA) complexes in human lymphoid populations; Samarut C et al.; Cells bearing Fc receptors were studied using a rosette technique with chicken erythrocytes coated with rabbit antibodies (EA) . By comparison with other markers and by selective depletion of T and B cells it was demonstrated that EA rosettes were formed by about 10% of the monocytes, 7% of the T lymphocytes, and 45% of the B cells . In addition, 26% of EA-rosette-forming cells (EA-RFC) in the peripheral blood carried on other markers than C3 receptors . Marked differences were found in the percentages of EA-RFC in cell suspensions from various lymphoid organs: peripheral blood, 15.2%; spleen, 26.6%; bone marrow, 30.9%; lymph nodes, 2.8%; thymus, 0.3%; and tonsils, 0.5% . It was concluded that Fc receptors were present on subsets of different lymphocyte subpopulations; their presence could not be regarded as a specific marker of one of these subpopulations.

Scand J Immunol, 1976, 5(1-2), 129 - 40
Genetic control of B-cell responses . II . Identification of the spleen B-cell defect in C3H/HeJ mice; Coutinho A; The responsiveness of spleen cells from C3H/HeJ and C3H/Tif mice to lipopolysaccharide (LPS) was compared . Around 1,000-fold higher concentration of LPS were required to minimally activate HeJ cells, as compared with Tif high-responder cells, to both proliferation and polyclonal antibody secretion . However, HeJ cells did respond to higher LPS concentrations (100 and 1000 mug/ml) . This selective pattern of responsiveness to LPS was also observed in the polyclonal responses of strains to LPS in vivo . Furthermore, the unresponsiveness of HeJ spleen cells was found to depend on a pure B-cell defect in the capacity to interact and/or generate triggering signals on interaction with LPS . Thus, adherent cells, thymus-derived lymphocytes, serum factors, and other non-specific conditions inherent in spleen cell suspensions of low-responder mice were not responsible for suppressing a putative B-cell response to LPS . The present findings are compatible with the possibility that the defect in C3H/HeJ B cells reflects the absence of a structure on the cell surface membrane that is functionally responsible for mediating LPS triggering.

J Immunol, 1976 Jan, 116(1), 156 - 8
Thymosin restores T cell function and reduces the incidence of amyloid disease in casein-treated mice; Scheinberg MA et al.; Evidence is presented that T cell impairment appears to be specifically related to the pathogenesis of experimental amyloidosis . This conclusion is based on the finding that thymosin administration improves T cell function as measured by mitogen stimulation of spleen cell suspension and at the same time reduces the incidence and severity of amyloid disease in casein-treated mice.

Arch Virol, 1976, 52(4), 297 - 306
Growth, purification and characterization of Semliki Forest virus in Ehrlich ascites tumor cell suspensions; Ivanic S; The growth of Semliki Forest Virus (SFV) in suspension cultures of Ehrlich Ascites (EA) cells and its purification is described . Large volumes of virus material were concentrated by filtration with DIAFLO XM-300 membrane and precipitation with ammonium sulfate . A combination of protamine sulfate treatment, centrifugation of the virus onto a 50 per cent sucrose cushion, and sedimentation through a 5--30 per cent sucrose density gradient was employed . The purified virus particles were homogeneous as revealed by electron microscopy, by moving boundary electrophoresis, and by polyacrylamide gel electrophoresis . Virus suspensions containing 1 mg/ml of protein had a hemagglutinin titer of 1:12,000 when measured with 0.25 per cent goose red blood cells.

Acta Morphol Acad Sci Hung, 1976, 24(4), 331 - 40
Bioassay of blood-born tumour cells on in vivo and in vitro systems; Dobrossy L et al.; Viability and biological integrity of tumour cells circulating in the blood were studied in an experimental system using bioassay methods . Results of subcutaneous and intravenous retransplantation as well as explantation of the blood obtained from tumour-bearing animals previously receiving intravenous inoculation of tumour cell suspension (Yoshida sarcoma, Walker 256 carcinosarcoma and DMBA-induced myeloid ascitic leukaemia), revealed that the tumour cells detected in the blood are not only viable at the time of their transportation in the blood-stream but are also in possession of biologic potentials to proliferate and establish metastatic growths in organs.

Acta Biol, 1976, 27(4), 281 - 90
Rosette formation of concanavalin A-treated erythrocytes around polymorphonuclear leucocytes and lymphocytes; Rohlich P et al.; Concanavalin A (Con A) induces rosette formation of erythrocytes around polymorphonuclear leucocytes and lymphocytes in cell suspensions of autologous human blood cells . The effect which is most characteristic in a concentration between 25 and 50 microgram/ml is due to Con A bound on the erythrocyte membrane . A similar effect, although less pronounced, was observed with phytohaemagglutinin at concentrations of 10 and 25 microgram/ml . The treated erythrocytes showed a higher affinity to polymorphonuclears when compared with lymphocytes . At the contact area, the membrane of the erythrocyte became highly folded while its free surface was smooth and spherical . The effect of the local concentration and immunobilization of the lectin on the erythrocyte membrane and the similarity of the contact pattern to that of erythrophagocytosis are discussed.

Biochimie, 1976, 58(10), 1195 - 211
Biosynthesis of mannan and mannolipids from GDP-Man by membrane fractions of sycamore cell cultures; Smith MM et al.; Membrane fractions have been prepared from sycamore (Acer pseudoplatanus) cell suspensions grown in liquid medium . These fractions catalyzed the transfer of mannoxyl-units from GDP-(14C) Man into a polymannoside, a mannolipid and oligosaccharide-lipids . The polymannoside was partially solubilized by proteolytic digestion or maceration in sodium dodecyl sulfate-urea mixtures . However no evidence is available of a covalent linkage between the biosynthesized glycan and peptides . The structural analysis of the (14C)mannan showed that the polysaccharide was a homopolymer of beta-(1 leads to 4) linked mannose with a few branches . During the incubation of the membranes with the substrate, the polymer chains elongated with a large number of sugar units and contained 25 to 40 hexose residues per non-reducing end monomer . GDP-Glc was a competitive inhibitor of the GDP-Man: beta-mannan mannosyl-transferase, whereas GDP-Man activated a GDP-Gle: beta-glucan glucosyl-transferase present in the same membrane preparation . Two kinds of glycolipids were synthesized in the presence of GDP-(14C)Man . The first (I) contained a polar moiety characterized as a mannose-phosphate and was very similar to polyprenyl-phosphate-mannose identified in plants by Alam and Hemming . The other mannolipid (II) was hydrolyzed by mild acid into labeled oligosaccharides of high molecular weight . This material was separated into two oligosaccharide fractions, the first (II A) of MW over 5000, the second (II B) of MW around 1700 . II B contained at most two labeled mannose residues per chain, linked to the non-reducing end of unlabeled units which probably contained neutral sugars and N-acetyl-osamine(s) near the reducing end . Oligosaccharide II A seemed to contain one or several II B chains.

Vox Sang, 1976, 31(1 SUPPL), 25 - 31
Collection of peritoneal exudate cells from small laboratory animals; Casciato DA et al.; A simple method for the collection of peritoneal cells from small laboratory animals is described . Peritoneal exudates were induced by either caseinate or glycogen, and the cells were retrieved through a closed system . The technique permitted repeated studies on individual animals and yielded consistently sterile cell suspensions.

Cancer Treat Rep, 1976 Jan, 60(1), 1 - 8
Effects and specificity of anticancer agents on the respiration and energy metabolism of tumor cells; Gosalvez M et al.; Using 35 new anticancer agents from the screening program of the National Cancer Institute we have performed a biochemical study of the effects on the respiration and oxidative phosphorylation of rat liver mitochondria and on the respiration of leukocyte, liver, L1210 leukemia, and Ehrlich ascites cell suspensions . Fifteen of the 35 compounds were found to be potent respiratory inhibitors as defined by 50% inhibition of mitochondrial respiration at concentrations of 110 mu mol/liter or less . The mechanism of respiratory inhibition by the drugs was either a rotenone-, antimycin-, or oligomycin-like effect . One triazine derivative showed some specificity for inhibiting tumor cell respiration in comparison with normal cell respiration . Two naphthoquinone derivatives showed inhibition of respiration in in vivo treatments at chemotherapeutic doses . It was concluded that data on respiratory effects may assist in the interpretation of the results of in vivo and in vitro screening tests of the drugs, and that in some cases, as with the naphthoquinone derivatives, the effects on respiration could be related to the mechanism of action or the mechanism of toxicity of the drugs.

Mech Ageing Dev, 1976, 5(6), 389 - 98
Lysosomal enzyme activities in parenchymal and nonparenchymal liver cells isolated from young, adult and old rats; Knook DL et al.; Parenchymal and nonparenchymal cells were isolated from the livers of female BN/BiRij rats, aged 3, 12, 24 and 30-35 months, by means of enzymatic techniques . About 70% of the cells in the nonparenchymal cell suspensions were endothelial cells and 25% were Kupffer cells . More than 90% of the isolated parenchymal, Kupffer and endothelial cells were viable as judged by trypan blue exclusion and ultrastructural appearance . The age-related changes in the specific activities of the lysosomal enzymes acid phosphatase, beta-galactosidase, cathepsin D and arylsulphatase B in parenchymal and nonparenchymal cells showed no correlated behavior . The most prominent change was observed for the cathepsin D activity in parenchymal cells, which nearly triples during the lifespan of the rat . A comparison of the activities obtained with homogenates of the whole liver and with parenchymal and nonparenchymal cells revealed that aging changes in lysosomal enzyme activities in homogenates should be carefully interpreted, since opposite patterns of change were often observed in the activities in parenchymal cells and in nonparenchymal cells.

J Immunol Methods, 1976, 12(3-4), 347 - 54
Acridine orange fluorescence cytochemistry for detecting lymphocyte immunoreactivity; Rolland JM et al.; Acridine orange staining reveals changes within 3 hours of in vitro stimulation of normal rat lymphocytes with mitogens, and of immune rat lymphocytes with the sensitizing antigen . An increased number of red fluorescent cytoplasmic organelles, presumably lysosomes are seen by fluorescence microscopy . Fluorimetry of the supernatants from stained cell suspensions suggests an overall decreased cell uptake of the dye . The microscopy and fluorimetry detected early events in the reaction of lymphocytes from tumour-bearing rats with the target tumour cells . It would appear that the changes in intracellular behaviour of the dye and in overall cell uptake after immune stimulation are a reflection of dissociated variations in internal and external cell membrane permeability, and may provide simple general means for recognizing cellular immune reactions.

Tsitologiia, 1976 Jan, 18(1), 102 - 5
{Use of a mixed cell suspension obtained from the livers of different rats for cytological studies}; Polishchuk AM et al.; The possibility of employing a mixed suspension of isolated liver cells from several rats for estimation of some quantitative characters commonly used in cytological investigations was studied . It is demonstrated that the disaggregation rate of liver in different animals varies slightly, and the mean values of the parametres studied (the proportion of dividing and binucleated cell) obtained from individual animals coincides well with those of the mixed suspension.

Mikrobiologiia, 1976 Jan-Feb, 45(1), 54 - 9
{Changes in the concentration of extracellular products and their composition in a synchronous culture of Chlorella pyrenoidosa in the presence of light and an elevated 02 concentration}; Maksimova IV et al.; An increase of oxygen concentration in a gaseous mixture passed through cell suspensions of Chlorella pyrenoidosa (from 21 to 100%) stimulates the production of extra-cellular organic substances and changes their composition . The cells accumulate in the medium glycolic acid rather than a variety of other substances . The accumulation of glycolic acid depends on the growth stage of the cells . The relation of production of extracellular organic substances by the algal cells to the ratio between the carboxylase and oxgenase activities of ribulose diphosphate carboxylase is discussed.

J Immunol Methods, 1976, 11(3-4), 297 - 301
A simple method of lymphocyte purification from human peripheral blood; Alderson E et al.; We present a simple technique for obtaining cell suspension from human peripheral venous blood containing on average 96% lymphocytes, no macrophages and leukocyte red blood cell ratio 1 : 1 . Cells are readily prepared under sterile conditions and can be used in culture experiments . The high yield of lymphocytes and the avoidance of Ficoll-Triosil makes the technique especially valuable for micro cytotoxicity tests such as those aimed at measuring tumour immunity.

Neoplasma, 1976, 23(2), 137 - 50
Investigation of the inhibitory activity of some mycobacterial strains on growth of the intratracheally transplanted Deals' sarcoma in guinea pigs; Schwartz E et al.; In this paper the authors describe and analyse results that they obtained by infection of the guinea pig organism carried out by subcutaneous or intratracheal application with five mycobacterial strains, namely Myco bovis BCG-Praha, Myco the H37Ra, Myco Kansasii, Myco fortuitum and Myco smegmatis . At predetermined time intervals following subcutaneously or intratracheally performed infection (on 7th, 16th, 28th and 56th day after infection) transplantation of a Deals' guinea pig sarcoma cell suspension was carried out in guinea pigs by the intraltracheal route . As it appears from the results gained the applied mycobacteria exhibit a partial inhibition of growth od Deals' guinea pig sarcoma cells of different character . From among the utilized strains the Myco bovis BCP-Praha and the Myco tbc H37Ra exhibited the highest, Myco fortuitum and Myco smegmatis the lowest inhibitory activity . Intratracheally performed infections yielded in general better results on the growth inhibition than infections carried out with the same strain but by the subcutaneous route . Furthermore, in the experiments reported on in the present paper the authors could verify their earlier experience, namely that inhibition of growth of sarcoma cells is most pronounced at the time of maximal biological activity (logarithmic phase of multiplication) of the applied mycobacterium.

J Immunol Methods, 1976, 10(4), 385 - 8
A raft technique for chemotaxis: a versatile method suitable for clinical studies; Addison IE et al.; We describe a raft technique for the study of chemotaxis which possesses a number of advantages over the use of chambers . Membranes are laid on pads soaked in chemotactic agent and cells are contained in plastic cups, which are inverted on to the membrane . This method gives results which are similar to those obtained in conventional vessels . It would seem well suited to comparative measurements of chemotaxis in clinical series, for it avoids the use of special chambers, minimises the number of membranes and their handling and more than one cell suspension can be placed on a membrane . In addition, the method is experimentally versatile: simple manipulations allow work with cells adherent to other surfaces, studies of the effect of substituting a new agent or of reversing the gradient during an experiment, migration against gravity, and of the effect of non-adherent cells on migrating cells.

J Immunol Methods, 1976, 10(4), 301 - 6
An improved autoradiographic technique for the detection of antibody-forming cells; Mason DW; An authoradiographic technique for the detection of antibody-forming cells has been developed for the assay of anti-DNP responses . The lymphoid cell suspension to be assayed was allowed to a glass slide coated with DNP-conjugated gelatin to which the secreted antibody bound during subsequent incubation . The bound antibody and its Ig class was revealed by a second incubation using 125I-anti-immunoglobulin reagents followed by autoradiography . Studies on the sensitivity and specificity of the method are presented and its advantages over other techniques described . The technique should be readily applicable to other haptens.

J Immunol Methods, 1976, 11(1), 55 - 62
A simplified procedure for in vitro immunization of dispersed spleen cell cultures; Kamo I et al.; Dispersed spleen cell suspensions from normal mice were immunized with sheep erythrocytes in flat bottom vial tubes containing a relatively small amount of tissue culture medium fortified with a 'nutrient cocktail' . The magnitude of the number of antibody plaque forming cells appearing in such tube cultures was equivalent or greater than that obtained in Marbrook vessels in the Mishell--Dutton system . Omission of the nutrient cocktail on the day of culture initiation, or the use of round bottom vials, resulted in much lower PFC responses.

Acta Med Scand, 1976, 199(4), 293 - 304
Distribution of immunoglobulin-containing cells in human bone marrow and lymphoid tissues; Turesson I; Cell suspensions of human bone marrow, spleen, lymph nodes and palatine tonsils have been investigated for the presence of intracellular immunoglobulins by a direct immunofluorescence technique, using monospecific antisera against human Ig heavy chains alpha, mu and gamma and light chains kappa and lambda . Serum Ig levels were determined and the number of positive cells was compared with the concentration and calculated synthetic rate of serum Ig in each individual . The 28 patients studied covered a wide range of diagnoses and included those with normal as well as pathologically decreased or increased serum Ig levels . There was a high correlation between the calculated synthetic rate of each Ig class and the percentage of cells positive for the same Ig class in the bone marrow but not in the spleen, lymph nodes or tonsils . The Ig-containing cells constituted a much larger proportion of the total lymphoid cell population in the bone marrow than in the peripheral lymphoid organs . The estimated total number of Ig-containing cells was also much larger in the bone marrow than in the other organs investigated . It is concluded that in man the bone marrow is the major site of serum Ig synthesis and that the average synthetic rate per cell is the same regardless which of the three major Ig classes is produced . The role played by different lymphoid organs in humoral immunity is discussed in the light of the present results and reported data regarding lymphocyte and plasma cell kinetics in mammals.

Exp Hematol, 1976 Jan, 4(1), 32 - 42
Histological alterations in spleen and bone marrow colonies produced by irradiation of the donor mice; Dunn CD; The previously reported decrease in the ratio of erythrocytic (E): granulocytic (G) spleen colonies observed 8 days after bone marrow transplantation, when the donors had been x-irradiated up to 4 hours before the marrow was taken for transfer, was confirmed . The effect of taking the marrow between 4 hours and 13 days after x-irradiation, on the E:G ratio in both spleen and femoral bone marrow colonies, has been studied in detail . The reversion to a normal E:G ratio in spleen colonies assessed at 8 or 10 days was associated with increases in this ratio of colonies in the femoral bone marrow . Transplantation of cell suspensions prepared from the spleen and femoral bone marrow of primary recipients 8 days after the initial transfer produced a histological distribution of 8-day colonies in secondary recipients which was indpendent of x-irradiation of the donor . The data suggest that a hypothesis involving CFU migration within the spleen and, possibly, from the bone marrow to the spleen, provides a more satisfactory explanation of the data than one involving two CFU populations with different radiosensitivities.

Dev Biol Stand, 1976, 35, 9 - 25
The use of suspension cultures for FMD vaccine production . Criteria for the evaluation of cells, virus and vaccine; Nardelli L et al.; A survey of problems connected with the cell suspension culture for the production of FMD vaccine is presented, in order to stimulate a discussion . Introductory remarks are made on the following topics: 1) suspension cell lines used for FMD vaccine production, 2) terminology, 3) criteria for the characterization of a cell culture, 4) evaluation of FMD virus produced according to the cell suspension technique and correlation existing between in vitro tests and antigenicity in domestic animals, 5) criteria which must be met by FMD vaccine produced from virus cultivated on cell suspension.

Somatic Cell Genet, 1976 Jan, 2(1), 77 - 80
Chilling of somatic cells unnecessary for Sendai virus-induced heterokaryon formation; Donner L et al.; Incubation of cell suspensions or monolayers at 4 degrees C for 20 min after addition of beta-propiolactone-inactivated Sendai virus did not enhance heterokaryon formation as compared to parallel cell cultures incubated at 37 degrees C immediately after the addition of Sendai virus . These findings show that the routine chilling of somatic cells in fusion experiments can be omitted.

Immunol Commun, 1976, 5(3), 189 - 203
A sensitive and reproducible assay for the quantitation of erythrophagocytosis and its correlation with reduction in tritiated thymidine uptake in a tumor target cell system modified by immunoenhancing or immunosuppressive agents; Scheetz ME 2nd et al.; A new and sensitive assay procedure for studying erythrophagocytosis is described . The assay technique permits quantitation of the in vivo and in vitro effects of chemicals, hormones, and cell, or microbrial products, on the level of phagocytic activation of glass-adherent cells . The effect of intraperitoneal injection of BCG, Zymosan, Vitamin A, B . pertussis, cortisone, estrone, and thioglycollate on phagocytic activation of peritoneal exudate cells harvested from two days up to 28 days following drug injection was examined by this assay . Erythrophagocytosis was compared to the effect of "activated" spleen cells on tritiated thymidine uptake of a tumor target cell suspension.

Hamatol Bluttransfus, 1976, 19, 207 - 19
Surface features of cells in human lymphoproliferative disorders . An immunoelectron microscopy study; Gourdin MF et al.; Peroxidase conjugated antibodies were applied to cell suspensions in order to detect surface associated immunoglobulins . Cell suspensions were fixed prior to incubation with reagents, a procedure avoiding membrane alterations induced by antibodies to surface component . By immunoelectron microscopy an identification of B lymphocytes could be made with simultaneous observation of their surface architecture . Basic findings were that normal circulating human B lymphocytes had a villous surface . This relationship was not confirmed however by examinating samples from various B and T cell proliferations establishing that surface morphology is not sufficient to categorize cells in disease . Specimens from hairy cell leukemia were also examined . Despite salient surface characteristics as revealed by the present method, the categorization of cells remains unclear.

Am J Hematol, 1976, 1(3), 325 - 30
Immunologic studies of human plasma cells; Beaulieu R et al.; Purified plasma cell suspensions were produced from 3 subjects with malignant plasma cell disease . Various physical, biological, and immunological properties of these cells were studied . Neoplastic human plasmablasts were found to be denser than their mature forms, in contrast to the usual relationship of the lymphoid, myeloid, and erythroid series . The human plasma cells did not respond to phytohemagglutinin stimulation and were found to be weakly reactive in mixed lymphocyte-plasma cell cultures . Potent antisera was produced against such cells, and the antisera demonstrated a broad cross reactivity with various human lymphocyte populations . The data suggest a lymphoid origin for human plasma cells and possibly a specific relationship to B-type lymphocytes.

Arch Geschwulstforsch, 1976, 46(2), 110 - 5
{Impulse cytophotometric investigations on tumour material (author's transl)}; Krug H; By impulse cytophotometry (ICP) we can get the distribution of the frequency of cell nuclei as a function of the fluorescence intensity . The interpretation of the curves is only possible on the basis of histophysical and histochemical features . The following problems are discussed: specificity of staining with ethidium bromide, pretreatment, detritus, comparison with other independent methods . The second peak of the karyogram consists of G2-cells and, in polyploidy of tetraploid cells . This peak is often high in cell suspensions of malignant tumours; sometimes we found polyploidy up to 16c . The stem line concept is discussed . The ICP is a valuable aid in exfoliative cytology, but no screening method.

Acta Derm Venereol, 1976, 56(1), 1 - 9
Studies on guinea pig skin cell cultures . V . Co-culture of pigmented melanocytes and albino keratinocytes, a model for the study of pigment transfer; Prunieras M et al.; Mixed cultures of melanocytes (M) and keratinocytes (K) are easily obtained from pigmented guinea pig ear skin . They are suitable for the study of pigment transfer from M to K . However, quantitation is difficult because many K are already loaded with pigment prior to cultivation . A technique is presented in which pigment-producing M are co-cultured with K of albino origin . Pigmented guinea pig ear skin is split with trypsin and basal cells including M are harvested . The cell suspension is treated with sodium citrate which prevents the attachment of K (but not of M) to the culture substrate . Ninety per cent pure M cultures are obtained . Five to seven days later, another basal cell suspension is prepared, this time from albino ear skin . This second suspension is seeded on top of the pigment-forming culture of M . The number of contacts between albino K and pigment-forming M increases as a direct function of time . Contrarily, the number of K which become pigmented increases until the fifth day of co-culture and decreases thereafter.

J Histochem Cytochem, 1976 Jan, 24(1), 355 - 62
Studies on human monocytes with a multiparameter cell sorter; Kwan D et al.; Suspensions of human lymphocytes and monocytes separated by the Ficoll-hypaque method from the peripheral blood show a Coulter volume distribution, measured with a multiparameter cell sorter, characterized by a minor peak at 500 mu3, containing 5-15% of the cells, and a major peak at 200 mu3 . Using fluorescent latex particles we have found that the monocytes, the cells that ingest the latex particles, all lie in the 500 mu3 peak; conversely, all of the cells in the 500 mu3 peak are monocytes . When the cell suspensions are incubated, the monocytes increase both the average volume and in absolute numbers . The number of monocytes approximately doubles during 3 days of incubation, when it reaches its maximum value . At that time we have found that all of the monocytes lack receptors for sheep red blood cells and all possess receptors for human gamma-globulin . The increase in monocyte number appears, therefore, to arise from the enlargement of "monocyte presursors" that resemble lymphocytes in volume and resemble both the monocytes and the B lyphocytes with respect to surface sheep red blood cell and human gamma-globulin receptors.

J Immunol, 1976 Jan, 116(1), 210 - 7
The effect of neonatal rat graft-vs-host disease (GVHD) on Fc receptor lymphocytes; Clancy J Jr et al.; The level of Fc receptor rosette-forming lymphocytes (Fc-RFL) was examined in spleen and lymph node cell suspension from neonatal DA and BN rats inoculated within 24 hr of birth with either allogeneic L (experimental) or syngeneic (control) lymphoid cells . In addition, these levels were compared to fetal and neonatal animals that received no injection . The indicator cells (EA) were sheep erythrocytes sensitized with one-half concentration of the highest dilution of rabbit anti-sheep erythrocyte IgG(A) which agglutinated an equal amount of 1% suspension of E . Care was taken to exclude scoring macrophages by injecting colloidal carbon at least 1 hr before killing the test animals . The spleen of 19-day DA fetal rats exhibited a level of 19.3% Fc-RFL, similar to that of animals having received adult syngeneic cells at birth (40.0%) by day 7 . Thereafter the level of Fc-RFL did not vary appreciably between these two groups . However, as early as 2 days after inoculation there was a significantly greater number of Fc-RFL in the spleen of experimental DA neonates compared to controls . The lymph nodes of experimental animals did not exhibit a significantly greater number of Fc-RFL until day 6 with both tissue compartments peaking at day 10 and remaining significantly higher than controls until death . In neonatal BN animals significantly higher levels of Fc-RFL in experimental animals were not evident as early and peaked later (day 12) in both tissue compartments but again these differences remained until death . Cytotoxic alloantisera demonstrated that on days 6, 10, and 12 most, if not all, of the Fc-RFL were host in origion in both DA and BN GVHD, with a very significant host plasma cell response in such GVHD animals . One-micron tissue section revealed the presence of a great number of plasma cell especially prominent in the medulla of lymph nodes with the cortex of lymph nodes and white pulp of the spleen markedly depleted of lymphocytes indicative of cytotoxicity.

Dtsch Med Wochenschr, 1975 Dec 12, 100(50), 2562 - 4
{T and B lymphocytes in skin changes of cutaneous lymphoma (author's transl)}; Burg G et al.; In 30 patients with benign or malignant lymphoreticular proliferation of the skin (38 skin biopsies) the percentage of immunoglobulin-bearing (B) and of spontaneous rosette-forming (T) lymphocytes was determined in cell suspension from homogenized tissue . Four main classes of cutaneous lymphoma could be differentiated: lymphocyte-rich (more than 50% of the infiltrate cells, predominantly B-lymphocytic, predominantly T-lymphocytic, mixed B and T-lymphocytic), lymphocyte-depleted (less than 50% of infiltrate cells), reticulo-histio-monocytic infiltrates, and reticulo- or lymphosarcoma . A definite statement was not possible (other than in leukaemic processes) if the accumulation of lymphocytic cells represented the primary malignant process rather than a concomitant inflammatory reaction . A clinically useful differentiation was into hyperplasia, paraplasia and neoplasia, as this takes into account different histopathological characteristics of cutaneous lymphomas (reactive hyperplastic/autonomic proliferative: benign/malignant; reversible/irreversible; systemic/nonsystemic; metastasizing/nonmetastasizing).

Biochim Biophys Acta, 1975 Dec 5, 411(2), 334 - 48
Cellular energy dependent agglutination of rat ascites tumor cells mediated by concanavalin A and Ricinus communis agglutinin; Kaneko I et al.; Effect of various metabolic inhibitors on the agglutination of rat ascites tumor cells mediated by concanavalin A and Ricinus communis agglutinin was studied using a quantitative assay method for agglutination in which turbidity of cell suspension is measured . Cell agglutination was inhibited by low temperature, cytochalasin B and inhibitors of energy generating systems without affecting lectin binding, and agglutination was not affected by hydroxyurea, actinomycin D or cycloheximide . The inhibitors of energy generating systems decreased the cellular ATP level and inhibited macromolecular synthesis under the conditions where they inhibited the agglutinations . In contrast, cytochalasin B did not depress the cellular ATP level nor inhibit RNA and protein syntheses . These results suggest that the agglutination is associated with cellular energy dependent processes other than macromolecular synthesis; probably with some cellular surface movements participated by microfilament activity.

Immunology, 1975 Dec, 29(6), 1019 - 28
Local and systemic immune responses following oral immunization of foetal lambs; Husband AJ et al.; Foetal lambs were immunized orally 6-15 days before birth by introducing horse spleen ferritin into the amniotic fluid . Immunized and non-immunized lambs were killed at birth, usually before they had suckled, blood and intestinal contents were collected and single cell suspensions were prepared from spleen, mesenteric lymph nodes and jejunum . Specific antibody was detected in serum and intestinal contents of all immunized lambs which had not suckled . Specific antibody was usually not detected in samples from non-immunized lambs . In immunized lambs antibody activity in serum was associated with IgM and in intestinal contents with IgA and IgM . In agreement with these findings, the levels of IgM and IgA in serum and intestinal contents of immunized lambs were relatively high . Generally, immunoglobulins were not detected in samples from non-immunized lambs . Relatively high proportions of cells secreting specific antibody were present in the tissues of immunized but not non-immunized lambs . In the spleen most of the cells were secreting IgM antibody, in mesenteris lymph nodes IgM cells predominated and small numbers of IgA cells were detected, and in the jejunum approximately equal numbers of IgA and IgM cells were secreting specific antibody.

J Natl Cancer Inst, 1975 Dec, 55(6), 1467 - 70
In vitro growth promotion of rat leukemia L5222 cells in the presence of 2-mercaptoethanol; Pourreau-Schneider N; Propagation of the transplantable acute rat leukemia L5222 in vitro was highly dependent on the reducing agent 2-mercaptoethanol (2-Me) . Maximum growth promotion was obtained in the simultaneous presence of 1.25-2.5 x 10-4m 2-Me and 30% fetal bovine serum in enriched tissue culture medium NCTC 135 . A short exposure to the reducing agent insured growth of the leukemia cells for 5 days, but extended culture necessitated constant presence of the thiol . After 2-8 days of culture, inoculation of the cell suspension produced widespread leukemia in inbred BD IX rats.

Endocrinology, 1975 Dec, 97(6), 1445 - 54
Surface modifications evoked by estradiol and diethylstilbestrol in isolated endometrial cells: evidence from lectin probes and extracellular release of lysosomal protease; Pietras RJ et al.; Endometrial cells were isolated from the uteri of ovariectomized rats . The inhibitory effect of alpha-methyl-D-mannoside on fluorescein-labeled concanavalin A (Con A) binding to these cells indicates that they possess specific binding sites for Con A . The lectin also mediates adsorption of homologous erythrocytes to these cells . Both Con A binding and Con A-mediated hemadsorption to endometrial cells are depressed at 4 C compared with these functions in cells maintained at 22 C . Gross elevations in lectin-mediated hemadsorption to endometrial cells are evident following prior exposure to 1 X 10(-9)M concentrations of diethylstilbestrol (DES) or estradiol-17beta, but not to the physiologically inactive 17 alpha-epimer, at 22 C . The enhancement of hemagglutinability cannot be attributed to a corresponding increase in lectin binding at 22 C . Although estrogen treatment elicited significant increments in Con A binding as early as 5 min after addition of estrogen to cell suspensions, the increment in agglutination attributable to hormone treatment consistently ranged from 1.5-3 times greater than the increase in lectin binding . These estrogenic effects were reduced by incubation of the endometrial cells at 4 C or when cortisol, 3 X 10(-6)M, was present with estradiol-17beta . In parallel experiments, treatment with DES and estradiol-17beta, but not estradiol-17 alpha, also enhanced the release of cathepsin B 1 and acid phosphatase from uterine segments into the particle-free extracellular media in which the tissues had been incubated for 30-60 min . The marked increment in the extracellular activity of the lysosomal hydrolases induced by estrogen treatment was suppressed in cells incubated at 4 C or when cortisol was present concomitantly . These and related data suggest the hypothesis that acute increments in lysosomal hydrolase activity may contribute to cell surface alterations which have been described in both normal and aberrant processes of cell growth.

Z Klin Chem Klin Biochem, 1975 Dec, 13(12), 545 - 8
{A simple extraction chamber for the analysis of gases by gas chromatography in small blood samples (50 microliters) (author's transl)}; Schachinger H; A sample extraction chamber for the determination of O2- CO2- and N2O-concentrations in 50 microliters blood samples by gas chromatography is described . These blood samples can be transferred anaerobically from the ear lobe of a patient or other donor by a doctor or medical auxillary . It is shown that N2O, O2 and CO2 are completely extracted from blood, red cell suspension and HCO3-solutions respectively . When the concentrations of the same sample was repeatedly measured the coefficient of variation was 1.3% for O2 and N2O and 1.2% for CO2.

J Cell Physiol, 1975 Dec, 86(3 Pt 1), 561 - 5
A mechanical dissociation method for preparation of muscle cell cultures; Tepperman K et al.; A cell preparation method by which large numbers of embryonic chick skeletal muscle cells may be obtained is described . The procedure requires fewer manipulations and much less time than standard trypsinization . By the criteria used, both methods are comparable with respect to percent viable cells and survival of plated cells . However, in addition to the ease of preparation, the mechanical dissociation method offers the significant advantage that the cell suspension is greatly enriched for myoblasts without the necessity of an additional preplating step.

J Immunol, 1975 Dec, 115(6), 1555 - 7
Ly antigens: markers of T cell function on mouse spleen cells; Hirst JA et al.; By the use of Ly antisera and complement it is possible to remove subpopulations of mouse T cells from spleen cell suspension . It is shown that these Ly antisera are specific for the Ly alleles carried by the cells . Helper cells from primed or unprimed mice and cells which respond to Con A express Ly-1 antigen but little or no Ly-2 antigen (Ly-1+ phenotype) whereas cells which respond to PHA express both Ly-1 and Ly-2 antigens (Ly-1+2+ phenotype).

J Exp Med, 1975 Dec 1, 142(6), 1403 - 15
Fc-receptors, Ia-antigens, and immunoglobulin on normal and activated mouse T lymphocytes; Krammer PH et al.; Using antibody coated bovine erythrocytes we were unable to demonstrate Fc-receptors on either thymus cells or T cells prepared from lymph node cell suspensions by anti-Ig column filtration . However, if parental thymus or lymph node T cells were transferred to X-irradiated F1 hybrids, activated donor T cells recovered from the recipient's spleen (ATC-spleen) were shown to express Fc-receptors . Fc-receptors were also demonstrable on ATC-spleen prepared between strain combinations differing at the M-locus . In marked contrast, Fc-receptors were not detected on ATC recovered from thoracic duct lymph (T.TDL) . This applied to (a) H-2-activated T.TDL derived from normal thymus cells, (b) H-2-activated T.TDL derived from thymus cells depleted of B cells, and (c) M-locus-activated T.TDL . Of these three populations, surface Ig (of B cell origin) was detected on a large proportion of the first but not on the second and third populations . Thus, the failure to detect Fc-receptors on any of these populations could not be attributed to blocking by adsorbed surface Ig . In addition, various T-cell populations were examined by a microcytotoxicity assay for the presence of cell surface Ia-antigens . 5--10% of the thymus cells, 20--30% of cortisone-resistant thymus cells, 60--70% of lymph node cells, and 60--80% of ATC-spleen and T.TDL showed Ia.

J Microsc, 1975 Dec, 105(3), 325 - 33
Distilled glutaraldehyde: its use in an improved fixation regime for cell suspensions; Gillett R et al.; A method is described for the sequential fixation of cell suspensions, suitable for use at room or culture temperatures . Though an adequate method for fixing cell suspensions does exist in the literature (Hirsch & Fedorko, 1968), it involves the use of a mixed glutaraldehyde-osmium tetroxide fixative . Since these two components inter-react, this method has many drawbacks . Previously described weaknesses of a sequential fixation regime (Hirsch & Fedorko, 1968; Jones, Yeh & Hirsch, 1972) with glutaraldehyde and osmium tetroxide have been overcome by the use of vacuum distilled glutaraldehyde as the primary fixative . The results, using a mixed glutaraldehyde-osmium tetroxide fixative and using the two components sequentially on a variety of cell types, are compared . The advantages of a sequential fixation made possible by the use of vacuum distilled glutaraldehyde rather than commercial glutaraldehyde are discussed.

Endocrinol Jpn, 1975 Dec, 22(6), 585 - 9
Some biological properties of human chorionic follicle stimulating hormone; Tojo S et al.; The biological properties of human chorionic FSH (hCFSH) for rat ovaries were investigated . Highly purified hCFSH had similar response to the ovarian augmentation test as bovine FSH and significantly enhanced 3H-thymidine uptake by granulosa cells and theca cells in the ovary of hypophysectomized rat . In contrast, highly purified hCG little responded to the ovarian augmentation test and had no effect on 3H-thymidine uptake by the ovary . These results indicate that hCFSH may promote the follicular growth of ovary resulting from granulosa cell proliferation and its enlargement . In addition, freshly harvested porcine granulosa cells were employed in an in vitro system to investigate specific binding of hCFSH to ovarian receptor . Radioiodinated hCFSH (125I-hCFSH) and hCG (125I-hCG) were respectively incubated with cell suspensions . Binding of these hormone preparations was proportional to the cell number and increased with the time of incubation through 120 minutes . The binding ability of 125I-hCFSH to the cells was greater than that of 125I-hCG . Increasing concentrations of unlabeled hCFSH in the incubation mixture progressively inhibited the uptake of 125I-hCFSH by granulosa cells . Unlabeled hCG was not able to compete with 125I-HCFSH binding . The similar phenomenon to inhibit the binding of 125I-hCG to the cells was also recognized in the presence of unlabeled hCG . These findings suggest that granulosa cell has at least two different types of receptor sites: one for hCFSH and the other for hCG.

Appl Microbiol, 1975 Dec, 30(6), 951 - 8
Tetramethyl-p-phenylenediamine oxidase reaction in Azotobacter vinelandii; Jurtshuk P Jr et al.; It was possible to quantitate the tetramethyl-p-phenylenediamine (TMPD) oxidase reaction in Azotobacter vinelandii strain O using turbidimetrically standarized resting cell suspensions . The Q(O2) value obtained for whole cell oxidation of ascorbate-TMPD appeared to reflect the full measure of the high respiratory oxidative capability usually exhibited by this genera of organisms . The Q(O2) value for the TMPD oxidase reaction ranged from 1,700 to 2,000 and this value was equivalent to that obtained for the oxidation of the growth substrate, e.g., acetate . The kinetic analyses for TMPD oxidation by whole cells was similar to that obtained for the "particulate" A . vinelandii electron transport particle, that fraction which TMPD oxidase activity is exclusively associated with . Under the conditions used, there appeared to be no permeability problems; TMPD (reduced by ascorbate) readily penetrated the cell and oxidized at a rate comparable to that of the growth substrate . This, however, was not true for the oxidation of another electron donor, 2,6-dichloroindophenol, whose whole cell Q(O2) values, under comparable conditions, were twofold lower . The TMPD oxidase activity in A . vinelandii whole cells was found to be affected by the physiological growth conditions, and resting cells obtained from cells grown on sucrose, either under nitrogen-fixing conditions or on nitrate as the combined nitrogen source, exhibited low TMPD oxidase rates . Such low TMPD oxidase rates were also noted for chemically induced pleomorphic A . vinelandii cells, which suggests that modified growth conditions can (i) alter the nature of the intracellular terminal oxidase formed (or induced), or (ii) alter surface permeability, depending upon the growth conditions used . Preliminary studies on the quantitative TMPD oxidation reaction in mutant whole cells of both Azotobacter and a well-known Mucor bacilliformis strain AY1, deficient in cytochrome oxidase activity, showed this assay can be very useful for detecting respiratory deficiencies in the metabolism of whole cells.

Endocrinology, 1975 Dec, 97(6), 1577 - 86
Aldosterone production by isolated adrenal glomerulosa cells: stimulation by physiological concentrations of angiotensin II; Fredlund P et al.; The production of aldosterone by isolated canine zona glomerulosa cells was measured after the incubation of cell suspensions with angiotensin II and ACTH, and during changes in extracellular potassium concentration . Adrenal cell suspensions were prepared by collagenase digestion and physical dispersion of the capsular layer of the dog adrenal cortex, and aldosterone production was determined by direct radioimmunoassay of cell incubation media . The isolated dog adrenal cells were highly responsive to angiotensin II, with aldosterone production significantly stimulated by concentrations of the octapeptide as low as 10(-11)M . Thus, the steroidogenic response of zona glomerulosa cells was consistently observed at peptide concentrations within the physiological range of angiotensin II in dog plasma, i.e., 2.0-5.0 X 5.0 X 10(-11)M . The maximum aldosterone response of 3-8 times the basal level of steroid production was induced by 3 X 10(-10)M angiotensin II, and a decrease in aldosterone production occurred at peptide concentrations above 10(-9)M . The aldosterone response of isolated adrenal cells to ACTH was consistently less sensitive than their response to angiotensin II, by a factor of 10-20 fold . Aldosterone production was significantly increased by 10(-10)M ACTH, and reached a maximum at 10(-8)M ACTH . By contrast with angiotensin II, ACTH usually evoked a higher maximal level of aldosterone production, and did not produce a decline in steroidogenesis at peptide concentrations above the level which caused maximum stimulation of aldosterone formation . Changes in the potassium concentration of cell incubation media were also accompanied by marked effects upon aldosterone synthesis which was abolished in the absence of potassium and became detectable in the presence of 0.5 mM K+ . After remaining constant between 2.5 and 4.0 mM K+, aldosterone production rose sharply above 4.5 mM K+ and reached a maximum at 8 mM K+ . These observations provide direct evidence that aldosterone production by zona glomerulosa cells is influenced by changes in angiotensin II levels within the normal plasma range.

Science, 1975 Nov 21, 190(4216), 784 - 5
Bone resorption restored in osteopetrotic mice by transplants of normal bone marrow and spleen cells; Walker DG; Capacity to resorb bone and calcified cartilage was restored permanently in mice with inherited osteopetrosis by the intravenous administration of cell suspensions prepared from spleen and bone marrow of normal littermates . Beginning near active growth plates as early as 2 weeks after transplantation, replacement of the abnormal spongiosa continued until medullary cavitites were fully expanded.

Int J Cancer, 1975 Nov 15, 16(5), 798 - 809
Host responses within solid tumors: non-thymus-derived specific cytotoxic cells within a murine mammary adenocarcinoma; Haskill JS et al.; The nature of host-derived, specifically cytotoxic cells infiltrating solid murine mammary adenocarcinomas (line T1699) was investigated . Cell suspensions obtained from enzymatically dispersed tumors were separated by sedimentation velocity . The host cell fraction was heterogeneous and contained T-lymphocytes, non-phagocytic cells bearing Fc receptors, eosinophils and monocytes . Host cells equivalent in size to small lymphocytes and bearing Fc receptors were found to be the predominant cell type responsible for colony inhibition . These colony-inhibiting cells were insensitive to lysis with either anti-theta or anti-IgG serum and complement; and they were specific both in their induction and in their mediation and in their mediation of cytotoxicity . Host cells made up the predominant population in spontaneously regressive tumors but only a minor component in progressive tumors, and they were totally absent from progressive tumors in X-irradiated animals.

Philos Trans R Soc Lond B Biol Sci, 1975 Nov 6, 272(915), 181 - 92
Cell communication by periodic cyclic-AMP pulses; Gerisch G et al.; At the surface of aggregating cells of the slime mould, Dictyostelium discoideum, two different sites interacting with extracellular cAMP are detectable: binding sites and cycl-nucleotide phosphodiesterase . Both sites are developmentally regulated . An adequate stimulus for the chemoreceptor system in D . discoideum is the change of cAMP concentration in time, rather than concentration per se: long-term binding of cAMP causes only short-term response . The system is, consequently, adapted to the recognition of pulses rather than to steady-state concentrations of cAMP . The ce,lls are, nevertheless, able to sense stationary spatial gradients and to respond to them by chemotactic orientation . The possibility is discussed that they do so by transforming spatial concentration changes into temporal ones, using extending pseudopods as sensors . The cAMP recognition system is part of a molecular network involved in the generation of spatio-temporal patterns of cellular activities . This system controls the periodic formation of chemotactic signals and their propagation from cell to cell . The phosphodiesterase limits the duration of the cAMP pulses and thus sharply separates the periods of signalling; the binding sites at the cell surface are supposed to be the chemoreceptors . The control of cellular activities via cAMP receptors can be studied with biochemical techniques with cell suspensions in which spatial inhomogeneities are suppressed by intense stirring, whereas the temporal aspect of the spatiotemporal pattern is preserved . Under these conditions it can be shown that the extracellular cAMP concentration changes periodically, and that the phase of the cellular oscillator can be shifted by external pulses of cAMP . It can also be shown that small cAMP pulses induce a high output of cAMP, which demonstrates signal amplification, a function necessary for a cellular relay system.

In Vitro, 1975 Nov-Dec, 11(6), 379 - 81
Use of the local anesthetic lidocaine for cell harvesting and subcultivation; Rabinovitch M et al.; Cell suspensions from monolayer cultures of 3T3, SV-3T3, BHK, BS-C-1, or macrophages, were prepared by brief exposure of the cultures to the amide anesthetic lidocaine . Cells were subcultivated six times without marked impairment of plating efficiency . The method should be applicable to physiological, biochemical, or immunological studies in which exposure of cells to proteolytic enzymes is to be avoided.

J Protozool, 1975 Nov, 22(4), 476 - 81
Fine structure of the oocyst walls of Isospora serini and Isospora canaria and excystation of Isospora serini from the canary, Serinus canarius L; Speer CA et al.; Oocysts of Isospora serini and Isospora canaria, from the canary Serinus canarius, were broken, added to a cell suspension, fixed in Karnovsky's fluid, and studied in the electron microscope . The oocyst wall of each species had an electron-lucent inner layer, a more osmiophilic middle layer and an outer layer of electron-lucent (I . serini) or electron-dense material interspersed with some electron-lucent material (I . canaria) . A few, relatively large lipid-like bodies were present in the outer or middle layer of the oocyst wall of I . canaria . As many as 9 membranes were present in the oocyst wall of I . canaria and 3 in that of I . serini . When exposed to a trypsin-sodium taurocholate fluid, sporozoites of I . serini excysted from 5-month-old sporocysts in vitro, but not from sporocysts stored for more than 6 months . No excystation occurred in 15-month-old I . canaria sporocysts . Similarities and differences in excystation between I . serini and other Isospora, Eimeria, and Sarcocystis species are discussed.

Biull Eksp Biol Med, 1975 Nov, 80(11), 66 - 70
{The importance of the density of spleen cell suspensions in cultures for development of immune reactions}; Gurvich AE et al.; A relationship was revealed between the number of cells in the suspension of the splenic tissue taken for induction of primary immunization of the reaction outside the organism and the number of the plaque-forming cells (PFC) formed by the end of incubation . It was shown that with increase of the cell density in the culture in the bottom of the incubation flask there was a 10-100 fold decrease of the PFC response; as to the cell viability--it was not affected or decreased but slightly . This effect was observed in using sheep red blood cells and water-soluble antigen extracted from them as an antigen . The effect was independent of shortage of the antigen or of the nutrient substances; it was accompanied by a general reduction of the 3H-thymidine incorporation into cultured cells.

Transplantation, 1975 Nov, 20(5), 362 - 7
The human splenic suppressor cell; Sampson D et al.; Studies of human spleen cell suspensions show that they contain a population of cells which can inhibit the mixed lymphocyte reaction . The cells appear to be able to suppress the patient's own response to an antigenic challenge in slightly greater degree than their ability to suppress a nonspecific mixed lymphocyte culture . The suppressive effect is dependent on cell dose and is linearly related to the log of cell concentration . At low dose these cells have no suppressive effect and, in fact, behave as stimulators . Exposure of these cells to an environment containing immunosuppressive drug abrogates their suppressor activity . Manipulation of these cells may prove to be of value in the control of graft rejection.

Eur J Biochem, 1975 Nov 1, 59(1), 9 - 15
Purification and properties of isoenzymes of cinnamyl-alcohol dehydrogenase from soybean-cell-suspension cultures; Wyrambik D et al.; Two isoenzymes of an NADP+ -dependent cinnamyl alcohol dehydrogenase and an NAD+ - dependent aliphatic alcohol dehydrogenase were extracted from cell suspension cultures of soybean (Glycine max L., var . Mandarin) which form lignin during growth . These enzymes could be separated from each other by chromatography on DEAE-cellulose and hydroxyapatite . The cinnamyl alcohol dehydrogenase isoenzymes were partially purified by (NH4)2SO4 fractionation, and column chromatography on DEAE-cellulose, Sephadex G-100, and hydroxyapatite . The molecular weight of the enzymes were estimated by the elution volumes from a Sephadex G-100 column and were found to be about 43,000 (isoenzyme 1) and 69,000 (isoenzyme 2) . Maximum rates of reaction were observed in the case of coniferyl alcohol oxidation at pH 9.2 (Isoenzyme 1) and pH 8.8 (isoenzyme 2); in the reverse reaction pH 6.5 was optimal for isoenzyme 2 . Whereas isoenzyme 1 is specific for coniferyl alcohol, isoenzyme 2 can also oxidize cinnamyl alcohol and a number of substituted cinnamyl alcohols, Km values for substituted cinnamaldehydes are 3-11 times lower than for the corresponding alcohols . Neither isoenzyme reacted with benzyl alcohol, anisic alcohol or ethanol . Substrate inhibition for the forward and reverse reaction was found with isoenzyme 2 but not with isoenzyme 1 . The equilibrium constant was determined to be about 10(9) in favour of coniferaldehyde reduction . The possible role of the cinnamyl alcohol dehydrogenase in lignin biosynthesis is discussed.

Arch Microbiol, 1975 Oct 27, 105(2), 123 - 7
The uptake and assimilation of sulphate by Thiobacillus ferrooxidans; Tuovinen OH et al.; Sulphate was rapidly bound by cell suspensions of Thiobacillus ferrooxidans . The binding was depressed by tetrathionate but was unaffected by Group VI anions, cysteine or methionine . Increasing uptake of sulphate was observed in cell suspensions incubated in the presence of ferrous iron . The bulk of 35S-sulphate was removed from the organisms by washing with dilute sulphuric acid and the remaining label was incorporated into cold trichloroacetic acid-soluble compounds . 35S-labelled adenosine 5'-sulphatophosphate was produced from ATP and 35S-sulphate by cell suspensions and in cell-free extracts . There was no evidence for the production of adenosine 3'-phosphate 5'-sulphatophosphate assayed by a very sensitive bioluminescence method.

J Biol Chem, 1975 Oct 10, 250(19), 7728 - 38
Role of anion translocation across the mitochondrial membrane in the regulation of urea synthesis from ammonia by isolated rat hepatocytes; Meijer AJ et al.; The regulation of urea synthesis from ammonia was investigated using isolated hepatocytes from fasted rats . Addition of ammonia alone produced only a small increase of urea formation, which was stimulated 2-fold by ornithine in conjunction with a fall of ATP levels and an accumulation of citrulline . Further addition of oleate or beta-hydroxybutyrate produced an additional 2-fold stimulation of urea formation to approximately 200 mumol/g dry weight/hour . The presence of oleate also protected against the inhibitory effect of 2,4-dinitrophenol on urea synthesis and the cellular ATP content . The data suggest that both the rate of of energy production and the rate of generation of reducing equivalents from endogensou substrates are insufficient to meet the requirements for optimal rates of urea synthesis . Urea formation from NH3 in the presence of ornithine and oleate, but iin the absence of gluconeogenic precursors, was inhibited by butylmalonate, a known inhibitor of malate-phosphate exchange across the mitochondrial membrane, and stimulated by theaddition of malate and other dicarboxylic acids and amino acids to the cell suspension...

Neurobiology, 1975 Oct, 5(5), 249 - 53
Oxygen uptake by suspension of mouse brain cells; Kovaru H et al.; A cell suspension was prepared by sieving mouse brain cortices in an isotonic solution of purified polyvinylpyrrolidone . A large increase on the O2-uptake by the suspension could be obtained with the preparation procedure described . The respiratory rate of suspension, incubated in saline medium, containing 6.2 mM K+, 10 mM pyruvate, 5 mM fumarate and 0.9 mM 5'-AMP, was equal to 68% of the respiratory rate of slices . High K+ concentration (65 mM) stimulated O2-consumption of suspension by 64% (73% in slices).

Blut, 1975 Oct, 31(4), 201 - 12
{Quantitative determination of human bone marrow proliferation kinetics during three culture days}; Boll I et al.; In order to obtaon of human bone marrow cells, fresh bioptic material was homogenized and the cell suspensions were incubated for 72 hs in a fluid medium . After 24, 48 and 72 hs of incubation the total cell number of the culture was determined . At the same time differential counts of stained smears were performed . Both, erythrocytopoiesis and granulocytopoiesis showed regeneration, maturation, and an absolute increase of the number of precursors and of mature cells . The quantitative data obtained in vitro during 24 hs correspond with our data of kinetics obtained by observed mitotic duration and cell differential countings in vivo . However, after a longer cultivation time we found a diminution of divisible precursors, and an increase of mature erythroblasts as well as an excessibe survival of the PMNs.

Am J Clin Pathol, 1975 Oct, 64(4), 472 - 6
Use of immunoperoxidase on brain tissue for the rapid diagnosis of herpes encephalitis; Benjamin DR et al.; An indirect immunoperoxidase method to detect herpes simplex viral antigen in brain cell suspensions from patients suspected to have herpes encephalitis is described . The method is rapid, reliable and specific, and successfully identified the herpes virus infected cells in four of five culture-proven cases . There was one false-negative reaction, but no false-positive . The immunoperoxidase technic offers a number of advantages over immunofluorescence for routine diagnosis.

Arch Int Pharmacodyn Ther, 1975 Oct, 217(2), 309 - 21
Lack of steroidogenic response to cyclic AMP and ACTH in adrenal cells from rats bearing the MtTF4 tumor; Rivkin I et al.; Adrenal cell suspensions prepared from rats bearing the MtTF4 tumor failed to increase corticosterone production when exposed to adenosine 3', 5'-cyclic monophosphate (cyclic AMP) or ACTH, placing the defect in these adrenals beyond the ACTH receptor site . Adrenal cells from normal rats responded well to these stimuli . Adrenal cyclic AMP phosphodiesterase prepared from the tumor bearing rats appeared normal both with respect to its specific activity and inhibition profile with theophylline . Exposure of the MtTF4 adrenal cells to 1,2-3H-cholesterol in the presence of either cyclic AMP or ACTH did not result in an increase in radioactively labeled corticosterone, whereas increased label could be demonstrated in adrenal cells from normal rats similarly treated.

Nippon Naibunpi Gakkai Zasshi, 1975 Sep 20, 51(9), 724 - 39
Comparative studies on the methods for the investigation of steroid metabolism in the liver (author's transl)}; Okumura J; It is reasonable to presume that the metabolism of the steroid hormones in the liver may play an important role in elucidating their physiologic significance . Although there are many methods by which the intrahepatic metabolism of the steroid hormones can be evaluated, little has been reported on a method to elucidate simultaneously such dynamic factors as metabolic rate, quantities passing through the liver, structural change, conjugation and the like . In this paper, comparative studies on the methods for the investigation of steroid hormone metabolism in the liver were carried out . These include batch incubation, dialysis, continuous flow perfusion, portal vein injection and the "tissue column method" which was newly designed in order to search for the dynamic factors described above in a simple system, simultaneously . In the "tissue column method" studied here, cell suspension of the rabbit liver mixed with Sephadex G 75 gel (4:1 in volume) was packed at the height of 4 cm in a glass column (internal diameter; 1.5 cm) . After an isotopically labelled steroid was placed on the tissue column, this column was perfused with oxygenated extracellular fluid (pH 7.4), keeping the perfusion system at 37 degrees C . The perfusion was continued for 60 min . and the perfusate was collected in 5 fractions . Flow rate was kept at 2 ml/min . When the perfusion was stopped, the cells were rapidly homogenized . The concentrations of the radioactivity in each perfusate, and in the final cells were measured . The amount of entry into the liver cells were calculated . The compounds in the perfusate and in the cells were separated by alumina column chromatography for analyzing the metabolites . Based on these experiments, the following conclusions were drawn; 1) Usual methods with liver slices and homogenates can clarify only the metabolic pathway . 2) To examine the amount of entry of steroids into the liver, portal vein injection as well as the "tissue column method" are preferable to the methods of dialysis and batch incubation . It seemed probable that the entry of steroids into the liver might not be explained simply on the basis of passive transfusion . 3) Incubation of slices and homogenate are of great advantage in studying the metabolic transformation in a specific organ . However, portal vein injection as well as the "tissue column method" are much more preferable to investigate the conjugation of steroids in the liver . 4) Continuous flow perfusion reported by Elrio Gurpide is suitable to examine the metabolism and the entry of steroids in a specific organ, but it is disadvantageous for investigating the conjugation of steroids because of its low production rate of conjugated steroids . 5) The portal injection method is intricate, troublesome and expensive, but this method provides a situation similar to in vivo circumstances...

Humangenetik, 1975 Sep 20, 30(3), 251 - 7
Apparent "in situ" clone of cytogenetically marked ataxia-telangiectasia lymphocytes; Hook EB et al.; Six adjacent metaphases, each with the same cytogenetic aberration of a group D chromosome, most probably a No . 14, were observed in a field of a slide from a 96-hour culture of lymphocytes from an individual with ataxia-telangiectasia (AT) . None of the 304 other metaphases examined from this or other simultaneous cultures of this individual showed such an aberration . It seems most likely that an "in situ" marked clone has been observed and this supports interpretation of consistent cytogenetic abnormalities in those with AT as having clonal origin . The method of slide preparation employed which involves placing, rather than dropping, the cell suspension on the slide may facilitate detection of "in situ" clones.

Arch Dermatol Res, 1975 Sep 12, 253(2), 105 - 12
{Mitogenic activity of melanoma extracts in leucocyte cultures (author's transl)}; Lischka G; From a mixed cell suspension of five primary melanomas an aqueous sterile extract was made and added to homologue leucocyte cultures of eight melanoma patients and seven controls . The extract had a blastogenic and mitogenic effect in all cultures . There was no significant difference between the responses of patients and controls . In experiments with an equally prepared extract of normal skin, added to homologue leucocyte cultures of nine persons, none but one had a positive reaction . This indicates, that the motigenic principle of the melanoma extract is not related to the histocompatibility antigen nor caused by chemical or bacterial contamination of the primary cell suspensions . It seems to be derived from the cytoplasmic fraction of melanoma cells . Other experiments to solve the problem were impossible because of lack of material . There are several reports in the literature which by using different methods indicate, that there might be an immunological reaction to melanoma associated principles in healthy persons, too.

Cancer Lett, 1975 Sep, 1(1), 29 - 32
The macrophage content of some human tumours; Gauci CL et al.; The number of macrophages present in 44 surgically removed breast tumours and melanomas was determined by making a cell suspension and measuring the proportion of cells which bound a heterologous anti-macrophage serum and spread rapidly in culture . The macrophage content of the different tumours ranged from 0% to 30% . The malignant tumours which were known to have metastasized, as well as metastatic lesions, all contained less than 10% of macrophages whereas cancers for which there was no evidence of spread at operation had widely varying numbers of macrophages.

J Natl Cancer Inst, 1975 Sep, 55(3), 659 - 63
RNA:DNA ratios in a developing fibrosarcoma and its lung metastases in C3H mice; Kravetz de Srulijes L et al.; The quantitative ratios of RNA:DNA were followed in a developing transplanted fibrosarcoma in C3H mice and in its lung metastases . There was a significant increase in these ratios in developing tumors originating from cell suspensions (P smaller than 0.001) and a single implanted piece (P smaller than 0.05) . No significant change was demonstrated in developing fibrosarcoma originating from two pieces of this tumor (P greater than 0.05) which were implanted simultaneously . When comparing the ratios of RNA and DNA of developing lung metastases to the primary tumors, we found a significantly higher ratio in the metastases (P smaller than 0.001) . No significant changes in RNA:DNA ratios were demonstrated in normal proliferating tissues either in physiologic hyperplasia or embryo tissue culture (P greater than 0.05).

J Morphol, 1975 Sep, 147(1), 41 - 59
An ultrastructural study of adhesive junctions in reaggregates of unincubated chick embryos; Macarak EJ; Cell suspensions obtained by the dissociation of unincubated chick embryo blastoderms were allowed to reaggregate on a gyratory shaker for 24-48 hours . The reaggregates which form during this period consist of an inner phase of tightly packed cohesive cells surrounded by an external phase of loosely packed cells . This sorted out arrangement achieves its definitive form between 24 and 48 hours of rotation culture . It was determined that the external phase consists of primitive ectoderm and that the internal phase consists of primitive endoderm . Both 24- and 48-hour reaggregates were examined in the electron microscope and observations were directed to areas of close membrane apposition between cells . In 48-hour reaggregates, primitive endoderm cells were joined by many specialized junctions (desmosomes) . The formation of desmosomes in reaggregates of dissociated unincubated chick embryo cells was correlated with the sorting out process.

Can J Microbiol, 1975 Sep, 21(9), 1357 - 61
Inhibition of oxidative metabolism in Escherichia coli by d-camphor and restoration of oxidase activity by quinones; Cardullo MA et al.; Oxidative metabolism in whole cells of Escherichia coli strain 82/r was inhibited by d-camphor when glucose, pyruvate, or succinate was used as substrate . Inhibition was not due to lower surface tension in d-camphor-treated cell suspensions nor was it a function of cell permeability . Succinic, lactic, and NADH-oxidase activities were inhibited in alumina powder cell-free extracts (80 mug of protein/ml) by d-camphor (1100 mug/ml) . NADH: and succinic: DCPIP oxidoreductase enzymes were unaffected by d-camphor . Menadione (vitamin K3) restored succinic, lactic, and NADH-oxidase activities in d-camphor-inhibited cell-free extracts . Concentrations of menadione used to restore succinic and NADH oxidase activities were not stimulatory in non-camphor-treated extracts . Succinic oxidase activity in d-camphor-inhibited cell-free extracts was also restored by ubiquinone (Q6) but not by vitamin K1 . These results are interpreted to indicate that d-camphor may affect quinone function in E . coli.

J Bacteriol, 1975 Sep, 123(3), 828 - 36
Differences in coupling of energy to glycine and phenylalanine transport in aerobically grown Escherichia coli; Sprott GD et al.; Differences exist in the coupling of energy to transport of glycine and phenylalanine in aerobically grown cells of Escherichia coli . Energy derived from respiration, although involved in both uptake systems, is not employed identically as shown by kinetic effects of cyanide and anoxia and by temperature dependencies . Additional evidence for aerobic differences was provided by the effects of azide which greatly decreased initial rates of uptake of glycine but not phenylalanine . The effect on glycine uptake was not due to uncoupling of oxidative phosphorylation or to a decrease in respiration rate . Evidence for anaerobic differences was provided by the addition of either glucose or ferricyanide to cell suspensions containing glycerol, thereby maintaining anoxic uptake of phenylalanine, but not glycine, at the aerobic level . Ferricyanide stimulation required a functional Ca, Mg-adenosine 5'-triphosphatase and involved cell metabolism . Ferricyanide was also found to produce differential stimulation of other amino acid transport systems; tyrosine, tryptophan and leucine uptakes were stimulated whereas those for alanine, proline, threonine, and glutamine were relatively unaffected.

Acta Cytol, 1975 Sep-Oct, 19(5), 448 - 52
Non-visual prescreening of cervical smears with a flow-through cytophotometer; Freni SC; An experiment was carried out with the fluorescence impulse cytophotometer I.C.P . 11 (Phywe, Gottingen, Germany) in a routine cytology laboratory . A total of 600 cervical smears were examined with 15 test samples of body fluids and tissue cultures . The results were compared with those obtained by classical Papanicolaou cytology and clinical "follow-up" . The main purpose was to find criteria for malignancy to be used as parameters in automated non-visual cytology . The main problems in the technique of preparing and measuring specimens have been discussed . Preparation of cell suspensions was time consuming; moreover, techniques were not completely controllable . A method for judging histograms was discussed . It appears that unless a better method is found for preparing suspensions of single, naked and undamaged nuclei, free from leukocytes, impulse cytophotometric measurement of DNA will remain an unreliable method for prescreening of cervical smears.

Biochem J, 1975 Sep, 150(3), 373 - 7
Oxidative phosphorylation during glycollate metabolism in mitochondria from phototrophic Euglena gracilis; Collins N et al.; Mitochondria were isolated by gradient centrifugation on linear sucrose gradients from broken cell suspensions of phototrophically grown Euglena gracilis . An antimycin A-sensitive but rotenone-insensitive glycollate-dependent oxygen uptake was demonstrated in isolated mitochondria . The partial reactions of glycollate-cytochrome c oxidoreductase and cytochrome c oxidase were demonstrated by using Euglena cytochrome c as exogenous electron acceptor/donor . Isolated mitochondria contain glycollate dehydrogenase and glyoxylate-glutamate aminotransferase and oxidize exogenous glycine . A P:O ratio of 1.7 was obtained for glycollate oxidation, consistent with glycollate electrons entering the Euglena respiratory chain at the flavoprotein level . The significance of these results is discussed in relation to photorespiration in algae.

Appl Microbiol, 1975 Sep, 30(3), 456 - 63
Separation of viable Rickettsia typhi from yolk sac and L cell host components by renografin density gradient centrifugation; Weiss E et al.; Rickettsia typhi cultivated in the yolk sac of chicken embryos or in L cells irradiated 7 days previously was separated from host cell components by two cycles of Renografin density gradient centrifugation . Preliminary steps involved differential centrifugation and centrifugation over a layer of 10% bovine plasma albumin of infected yolk sac suspensions, or trypsinization and passage through filters of wide porosity of infected L cell suspensions . Rickettsial preparations obtained by these methods appeared to be free from host cell components while retaining high levels of hemolytic activity, egg infectivity, and capacity to catabolize glutamate . Average yields were 3.3 mg of rickettsial protein per yolk sac or 0.44 mg per 16-oz (ca . 475-ml) L cell culture . Extracts from these two preparations displayed malate dehydrogenase activity of electrophoretic mobility identical to each other but quite different in migration patterns from the corresponding host cell enzymes . This method of separation of rickettsiae from host cell constituents appears to be particularly well suited for the study of rickettsial enzymatic activity.

J Clin Microbiol, 1975 Sep, 2(3), 243 - 6
Dispersion and cultivation of renal cells after short-term storage of kidneys; de Oca HM et al.; A new method for the preparation of cell suspensions from human newborn kidneys is described . It involves the use of a mixture of trypsin-ethylenediaminetetraacetic acid and collagenase . The cell yields obtained after tissue dispersion by this method were significantly greater than those obtained after dispersion with either trypsin or ethylenediaminetetraacetic acid alone or in combination . When kidneys were removed 12 h or more postmortem from refrigerated cadavers, higher cell yields were obtained from renal tissue stored overnight at 4 to 6 C in CMRL ATM (Healy and Parker, 1966), as compared to cell yields obtained from kidneys processed immediately upon removal . This observation was confirmed by controlled experiments performed with rabbit kidneys.

Clin Exp Immunol, 1975 Sep, 21(3), 442 - 55
Immunological responsiveness of frozen-thawed human lymphocytes; Strong DM et al.; Mononuclear cells (10--20 X 10(6)) obtained from human peripheral blood by a standard Ficoll-Hypaque technique were suspended in RPMI 1640 media at 4 degrees C containing 10% foetal calf serum and 7-5% dimethyl sulphoxide (DMSO) . Two-millilitre aliquots were cooled at -1 degree C/min in a Cryoson BV-4 programmed freezing system to -30 degrees C, then -5 degrees C/min to -80 degrees C and stored in liquid nitrogen vapor . On the day of testing, cell suspensions were thawed rapidly in a 37 degree C water bath . DMSO was diluted slowly out of the sample and cells resuspended in fresh RPMI 1640 . It was found that frozen stored human lymphocytes (FSHL) demonstrated all the characteristics of fresh unfrozen cells . These included their ability to form spontaneous rosettes with sheep erythrocytes ('E' rosettes) and sheep erythrocyte--antibody--complement rosettes ('EAC' rosettes) . The presence of surface immunoglobulins and Fc receptors were shown by membrane immunofluorescence to be comparable . In addition, the results show that FSHL respond to mitogens, specific antigens; act as both stimulators and responders in the mixed lymphocyte culture reaction; and exhibit cell-mediated lymphocytotoxicity following in vitro sensitization, or against antibody-coated target cells.

What Is Botulism?, What Is Biofilm?, What Is Rhizobia?, What Is Environmental Microbiology?, What Is Water Purification?, s, Microorganisms, e, Bacteriology, n, Bacterium, e, Microorganism, r, Bacteria, n, Streptococcal, c, Bacillus, o, Lactobacillus, i, Bacillus anthracis, n, Meningococcus, o, Streptococci, a, Bacillus, c, Microbial, o, Sepsis, n, Biofilms, c, Antibiotics, r, Pseudomonas, s, Lactobacillus, n, Bacillus subtilis, e, Functional genomics, a, Escherichia coli, s, S. cerevisiae, a, Enterobacteriacea, a, O157, n, E coli O157, r, Eubacter

Scientific Publications - Work Done by Microbiology Reader Bioscreen C
Agricultural Microbiology Anaerobic Microbiology Antimicrobial Susceptibility Artificial Atmosphere Bioassay of Antibiotics Biofilm Microbiology Bioreactor Technology Biotechnology Cell Biology Clinical Microbiology Environmental Microbiology Experiments with Yeast	Fermentation Food Microbiology Functional Genomics Gene Technology Growth Media Development Growth Rate and Lag Time Industrial Microbiology Medical/Pharmaceutical Field Microbiological Assay Microbiological Research Microbiology of Cosmetics go to a specific theme...	Military Microbiology Molecular Microbiology Mutagenicity and Genotoxicity Oral Microbiology Patents Postantibiotic Studies Soil Microbiology Spore Microbiology Veterinary Microbiology Waste/Wastewater Treatment Water Microbiology Wine Microbiology

� 2005 Transgalactic Ltd (manufacturer of Bioscreen C software) | Privacy Statement | P.O. Box 1393, 00101 Helsinki, Finland, phone: +358 9 85172920, fax: +358 9 8749481, e-mail: microbiology@bionewsonline.com

Last modified: May 25, 2005