Mol Gen Genet, 1980, 179(2), 457 - 60 Regulation of the synthesis of nucleoside catabolic enzymes in Escherichia coli: further analysis of a deo Oc mutant strain; Albrechtsen H et al.; Four genes, deoA, deoB, deoC, and deoD, involved in the synthesis of nucleoside and deoxynucleoside catabolic enzymes, are located contiguously in the order C-A-B-D on the linkage map of E . coli . They constitute two overlapping operons, one transcribing all the four genes and the other deoB and deoD . To the left of deoC are located two promoter-operator regions in the order deoPO-cytPO . They are involved in controlling the expression of the tetracistronic mRNA . For efficient binding of RNA polymerase at the cytPO site the cAMP+CRP complex is required, whereas binding of RNA polymerase at the deoPO site is independent of this complex . Evidence is available for the existence of yet another controlling site, PO-3, located between deoA and deoB; this controls the expression of deoB and deoD . Both the operons are transcribed in a clockwise direction . An operator constitutive (Oc) type mutant affecting the synthesis of all four deo enzymes has been analysed . Because of this mutation the strain has become insensitive to catabolite repression . The results confirm the order of the gene in the controlling region to be deoPO-cytPO and the mutation, previously analysed as a deletion, appears to have deleted cytPO deoC region of the chromosome. J Immunol Methods, 1980, 38(3-4), 205 - 16 A simplified immunoenzyme antigen binding technique as an approach for immunodiagnosis; Bahr G et al.; A simple immunoenzyme technique is described in which the enzyme beta-galactosidase of E . coli (Z) is used as a marker . The principle of the test is based on the ability of the cells to bind the antigen . Conditions of the assay using Z both as the antigen and marker are described . As a screening technique, conditions are defined at limited antigen concentrations when binding is not directly proportional to the number of cells present . Hence, drops of blood can be used directly for detection of an immune response without counting the cells . Furthermore, treatment of whole blood with ethanol was shown to (a) increase the binding capacity and (b) allow the storage of specimens for weeks without any loss of activity . With human hydatid fluid (HHF) antigens conjugated to Z as a model, it was possible to detect the immune response of rabbits injected with HHF . The method is simple, requires no sophisticated equipment and can be used in large scale epidemiological surveys. Genetika, 1980, 16(1), 66 - 77 {Cloning of threonine operon genes in Escherichia coli cells}; Kozlov IuI et al.; A set of hybrid plasmids carrying Escherichia coli threonine genes was obtained and cloned . The plasmid pBR322 was used as a vehicle . The genetic and restriction analyses showed that genes thrA and thrB were placed between SalGI and EcoRI sites on the 2.6 megadaltons DNA region . The transcription of threonine operon genes inserted in the hybrid plasmids is under the control of its own promoter . The copy number of hybrid plasmids was reverse proportional to their molecular weight and did not depend on the replicon number . Amplification of genes of threonine operon by hybrid plasmids led to 20-25-fold increase of homoserine dehydrogenase activity, encoded by thrA gene . The expression of this gene, incorporated in hybrid plasmids, was repressed by the addition of threonine and isoleucine in the culture medium. Scand J Gastroenterol, 1980, 15(3), 311 - 4 Endotoxin-induced microclots in ulcerative colitis and Crohn's disease; Juhlin L et al.; Radially oriented fibrin microclots were observed when blood from patients with active lesions of Crohn's disease and ulcerative colitis was kept in capillary tubes for 24 h . Addition of bacterial extract or endotoxins increased the fibrin formation . The phenomenon is not seen in healthy subjects or patients who have healed after colectomy . The data are consistent with our findings in patients with vasculitis and support the view that patients with Crohn's disease and ulcerative colitis have circulatory endotoxins. Eur J Biochem, 1980, 108(1), 213 - 21 The complex formation between Escherichia coli aminoacyl-tRNA, elongation factor Tu and GTP . The effect of the side-chain of the amino acid linked to tRNA; Wagner T et al.; The interaction between Escherichia coli aminoacyl-tRNAs and elongation factor Tu (EF-Tu) x GTP was examined . Ternary complex formation with Phe-tRNAPhe and Lys-tRNALys was compared to that with the respective misaminoacylated Tyr-tRNAPhe and Phe-tRNALys . There was no pronounced difference in the efficiency of aminoacyl-tRNA x EF-Tu x GTP complex formation between Phe-tRNAPhe and Tyr-tRNAPhe . However, Phe-tRNALys was bound preferentially to EF-Tu x GTP as compared to Lys-tRNALys . This was shown by the ability of EF-Tu x GTP to prevent the hydrolysis of the aminoacyl ester linkage of the aminoacyl-tRNA species . Furthermore, gel filtration of ternary complexes revealed that the complex formed with the misaminoacylated tRNALys was also more stable than the one formed with the correctly aminoacylated tRNALys . Both misaminoacylated aminoacyl-tRNA species could participate in the ribosomal peptide elongation reaction . Poly(U)-directed synthesis of poly(Tyr) using Tyr-tRNAPhe occurred to a comparable extent as the synthesis of poly(Phe) with Phe-tRNAPhe . In the translation of poly(A) using native Lys-tRNALys, poly(Lys) reached a lower level than poly(Phe) when Phe-tRNALys was used . It was concluded that the side-chain of the amino acid linked to a tRNA affects the efficiency of the aminoacyl-tRNA x EF-Tu x GTP ternary complex formation. CRC Crit Rev Biochem, 1980, 8(2), 175 - 89 Comparative studies on the regulation of tryptophan synthesis; Crawford IP; In vitro DNA recombination techniques have revolutionized the study of genetic control of biosynthetic pathways . Using examples drawn from the pathway of tryptophan synthesis, approaches to the deciphering of regulatory signals and response mechanisms through transposition of DNA segments and DNA sequence analysis will be presented . After reviewing the known chromosomal arrangements and regulatory patterns of trp genes in the bacterial groups studied so far, and describing the results of transferring all or part of the pathway's genes from one organism to a distantly related one, the use of this technique to analyze new organisms will be described . Along with some advantages over the conventional methods there are some pitfalls . Finally, since it is likely that events analogous to recombinant DNA experiments take place readily in nature, their consequences in studies of bacterial evolution will be conjectured. Mol Gen Genet, 1980, 178(2), 293 - 9 High efficiency temperature-sensitive amber suppressor strains of Escherichia coli K12: construction and characterization of recombinant strains with suppressor-enhancing mutations; Oeschger MP et al.; A set of eight strains combining the supD43,74 ts1 suppressor gene with alleles of three suppressor-enhancing (sue) genes have been constructed and characterized . The sue mutations work cooperatively to raise suppressor activity and together raise the activity of the supD43,74-encoded suppressor 40-fold . These strains further expand the utility of the ts suppressor system by providing as much as 100% suppressor activity at temperatures at or below 20 degrees C to as little as 0.015% suppressor activity at 43 degrees C. Enzyme, 1980, 25(2), 127 - 31 Preparation of water-soluble high-molecular weight substrates for beta-D-galactosidase; Madhav R et al.; Two types of high-molecular water-soluble substrates of beta-D-galactosidase were prepared . Substrate I contains beta-D-{3H}-galactopyranosyl moieties linked, through a hydrocarbon bridge, to a polymeric dialdehyde (oxidized starch) backbone (molecular weight 6,000); in substrate II the backbone is poly-L-lysine (molecular weight 80,000) . In the presence of Triton X-100, but not in its absence, D-{3H}-galactose is split from the substrates by homogenates of normal mouse liver or pancreas . It is suggested that substrates I and II could be used to test the integrity of lysosomal and other cellular membranes, and to assess the extent of cellular injury. Hoppe Seylers Z Physiol Chem, 1980, 361(2), 105 - 17 The primary structure of L-asparaginase from Escherichia coli; Maita T et al.; The carboxymethylated L-asparaginase from Escherichia coli A-1--3 was fragmented with cyanogen bromide and the resulting peptides were isolated by using gel filtration on Sephadex G-50 and column chromatography on DE-52 . The amino acid sequences of the 7 cyanogen bromide peptides thus obtained were established completely or partially by further fragmentation with trypsin, chymotrypsin and pepsin, and the Dansyl Edman method . Based on the above results and the complete sequences of the tryptic peptides from the carboxymethylated L-asparaginase reported in the previous paper, the whole sequence of the enzyme was established . The reported sequence consists of 321 amino acid residues and its calculated molecular weight is 34 080. J Bacteriol, 1980 Jan, 141(1), 297 - 304 Accumulation of guanosine tetraphosphate and guanosine pentaphosphate in Myxococcus xanthus during starvation and myxospore formation; Manoil C et al.; Cultures of Myxococcus xanthus develop multicellular fruiting bodies when starved for carbon and nitrogen sources on an agar surface . Under these conditions of severe starvation, cultures rapidly accumulated a compound identified as guanosine tetraphosphate by chromatographic migration of the compound and of its major acid and alkali breakdown products . The accumulation of guanosine tetraphosphate was reduced in the presence of tetracycline, indicating that it may be synthesized by mechanisms similar to those of Escherichia coli . The guanosine tetraphosphate level was also reduced in starved cultures of a mutant unable to fruit normally, although it has been determined whether the defect in guanosine tetraphosphate accumulation is responsible for the inability to fruit . Induction of spores by glycerol addition led to transient increases in both guanosine tetraphosphate and guanosine pentaphosphate at a stage following most cell shortening, but before spores had acquired full refractility. J Exp Med, 1980 Jan 1, 151(1), 81 - 90 Induction of acute cholecystitis by activation of factor XII; Becker CG et al.; Acute, acalculous cholecystitis is seen among patients suffering with bacterial sepsis, burns, trauma, or cancer; clinical conditions that could lead to activation of factor XII-dependent pathways and result in inflammation of the gall bladder . To test this hypothesis, dogs were injected intravenously with ellagic acid or rutin, known polyphenol activators of factor XII, or with Escherichia coli endotoxin, also known to activate factor XII, and monkeys were injected intravenously with ellagic acid . In both species, in vivo activation of factor XII-dependent pathways with polyphenol activator resulted in rapid and selective development of acute vasculitis in the serosa and muscularis of the gallbladder and margination of polymorphonuclear neutrophils in pulmonary blood vessels . Intravenous injection of E . coli endotoxin in dogs resulted in necrosis and thrombosis of vessels that were especially severe in the serosa and muscularis of the gallbladder but also present in vessels of many other organs . These observations indicate that blood vessels of the gall bladder and, to a lesser degree, the lung are especially sensitive to injury consequent to in vivo activation of factor XII-dependent pathways and, in view of the common ingestion of plant polyphenols, may provide important insight into the pathogenesis of cholecystitis in man. Adv Shock Res, 1980, 3, 105 - 16 Cardiogenic endotoxin shock: coronary flow and contractile protein dysfunction as determinants of depressed cardiac contractility; Krause SM et al.; Cardiogenic endotoxin shock (ES) refers to the intermediate and latter stages of ES characterized by a progressive myocardial dysfunction . This laboratory has been developing the hypothesis that a major etiology of this observed myocardial failure is a progressive state of global ischemia . In order to further test this hypothesis, ES (E coli, Difco Labs, 026:B6, 4 mg/kg) was induced in the canine model (n = 6) and coronary flow, myocardial contractility (dP/dtmax), and systemic hemodynamics were continuously monitored for five hours, following which the cardiac contractile proteins were isolated and characterized . In the ES group, control coronary flow (CF) = 90.5 +/- 3.6 ml/min/100 gm LV, coronary vascular resistance (CVR) = 61.82 X 10(3) +/- 2.28 X 10(3) dyne . sec . cm--5 and dP/dtmax 2,200 +/- 160 mm Hg/sec . Between four and five hours, CF decreased to 58.6 +/- 16 ml/min/100 gm LV, CVR increased to 128.6 X 10(3) +/- 18 X 10(3) dyne . sec . cm--5, and dP/dtmax decreased to 968 +/- 62 mm Hg/sec . Sham animals (n = 7) demonstrated no significant difference in CF, CVR, or dP/dtmax . Control myofibrillar ATPase activity demonstrated 50% activation (specific activity = 0.072 +/- 0.002 mumoles Pi/mg protein . min) at p Ca++ = 6.4, with no significant difference between endocardium and epicardium . ES myofibrils demonstrated 50% activation (specific activity = 0.060 +/- 0.002 mumoles Pi/mg protein . min endocardial, and 0.068 +/- 0.005 mumoles Pi/mg protein . min epicardial at pCa++ = 6.48 and 6.45, respectively, incriminating a change in affinity for Ca++ binding to the regulatory proteins . Thus, it would appear that the documented decrease in myocardial contractility is due in part to a depression of myofibrillar ATPase activity, which is related to a decrease in coronary flow, an increase in coronary vascular resistance, and a state of global myocardial ischemia. Agents Actions Suppl, 1980, 7, 199 - 203 Splenic suppressor cells in adjuvant arthritic rats: effect of D-penicillamine; Binderup L et al.; Adherent spleen cells from rats with adjuvant arthritis inhibit the incorporation of 3H-thymidine into DNA and 3H-leucine into protein in nonadherent spleen lymphocytes, stimulated by the mitogens Concanavalin A and E . coli Lipopolysaccharide . This suppressive activity was abolished by pretreatment of the adherent cells with the selective macrophage toxin silica . It is suggested that suppressor macrophages directly, or through interaction with suppressor T cells, inhibit the response of lymphocytes to mitogens by inhibition of cellular protein synthesis, followed by inhibition of DNA-synthesis and death of about 30% of the lymphocytes . Treatment of adjuvant arthritis rats with D-penicillamine resulted in significantly increased incorporation of 3H-thymidine in spleen lymphocytes, compared to cultures from untreated, arthritic rats . This approach may prove useful in the investigation of cellular interactions in a model of immunologically induced inflammation and provide a tool for the evaluation of the effects of immunoregulatory drugs. Basic Life Sci, 1980, 15, 25 - 43 Role of cellular systems in modifying the response to chemical mutagens; Strauss B et al.; Neocarzinostatin (NCS) produces apurinic/apyrimidinic (AP) sites in DNA which are repaired by the AP excision repair system . Survival after NCS treatment is not determined exclusively by this repair system, presumably because of the production of other, lethal, lesions . MNNG also produces multiple lesions which may be handled by cells in different ways . In E . coli, MNNG treatment results in rapid induction of a system which removes O6-methylguanine . Inhibition of this induction with chloramphenicol results in a large increase in mutation frequency . Induction of an enzyme which removes O6-methylguanine probably accounts for the enrichment of mutations near DNA growing points . MNNG also induces multiple closely linked mutations . The production of multiple mutations but not of single-site mutations is blocked in rec A and uvr E strains . The exact nucleotide site at which DNA synthesis is blocked in vitro by reaction with mutagens can be observed in a phi X174 system in which the nucleotide sequence is known . DNA polymerase I catalyzed synthesis is blocked one nucleotide before the reacted base on the template strand . In contrast, with some damaged templates, AMV reverse transcriptase can insert a base at the level of the reacted nucleotide on the template. Allerg Immunol (Leipz), 1980, 26(3), 222 - 42 {Immunostaging of patients with chronic pancreatitis . I . A study of humoral and cell-mediated immunity (author's transl)}; Schutt C et al.; Immunostaging was performed in patients with chronic pancreatitis of different etiologic groups . Immune responifveness was assessed by immunoglobulin serum levels, non specific autoantibody formation, C3 levels, antistreptolysin reaction, antibody titer against Toxoplasma gondii, E . coli, Herpes simplex-, Mumps- and Cytomegalovirus and screening for soluble immune-complexes (PEG precipitation assay), number of T- and B-lymphocytes, lymphocyte responsiveness to PHA, PPD, tetatoxoid and mumps-antigen in a whole blood assay, skin testing with candidin, trichophytin, tuberculin and streptokinase and HLA-typing . In some cases we found a depressed cell-mediated immune responsiveness . Patients were divided into two groups based on this main finding . Cellular hyporesponsiveness was correlated to the severity of the disease and a high incidence of HLA-B5 but not to any etiologic factor of the disease. Mol Gen Genet, 1980, 180(2), 369 - 76 An unusual RNA polymerase binding site in the immunity region of phage lambda; Pirrotta V et al.; RNA polymerase binds very tightly at a site called Brex in the lambda immunity region, to the left of the rex gene and about 600 nucleotides to the right of PL . The complex formed is resistant to 1 M NaCl in the absence of nucleotide triphosphate . While in vitro little or no transcription is observed from Brex, in vivo, when inserted in a plasmid vector which allows detection of its activity, it acts as an efficient promoter . We have mapped the site protected by RNA polymerase against DNase and determined its sequence which is abnormal compared that of an average promoter. Mol Gen Genet, 1980, 180(2), 343 - 9 Isolation and characterization of specialized transducing lambda phages carrying ribosomal protein genes of Escherichia coli; Kitakawa M et al.; Specialized transducing lambda phages have been isolated which carry the regions of the Escherichia coli chromosome containing the gene or gene-clusters for ribosomal proteins (r-proteins) S1, S6-S18-L9, S16-L19, and L28-L33 . To investigate whether these phages also carry the genes for r-proteins S9, L13, L20, L31 and L34 whose gene locations are not known, cells irradiated with UV light were infected with these phages and the r-proteins synthesized were analyzed by two-dimensional gel electrophoresis . However, no synthesis of these r-proteins was stimulated, indicating that their genes are not located in the neighborhood of any of the above-mentioned genes or gene clusters . It was found that proteins S6 and S18 synthesized in the cells irradiated with UV light were not modified under these conditions in which no concomitant ribosome assembly took place. Mol Gen Genet, 1980, 180(2), 331 - 41 Synthesis of ribosomal proteins in merodiploid strains of Escherichia coli; Dowsett SJ et al.; The regulation of the synthesis of r-proteins in Escherichia coli was investigated by increasing the dosage of the genes for a limited number of ribosomal proteins (r-proteins) using either transducing phage lambda fus 3 (Lindahl et al . 1977) or lambda rifd 18 (Kirschbaum and Konrad 1973) . During exponential growth the presence in the cell of either lysogenised transducing phage did not increase the rate of synthesis or degradation of any of the 31 r-proteins whose genes are duplicated . Experiments were also performed to determine whether r-protein synthesis during the period of unbalanced r-protein synthesis that follows nutritional enrichment was sensitive to an increase in gene dosage . Duplication of the 27 r-protein genes on lambda fus 3 did not alter the rate of synthesis of any of the r-proteins after enrichment . However, gene dosage effects were detected for at least 3 of the r-proteins whose genes were duplicated on lambda rifd 18. Mol Gen Genet, 1980, 180(2), 283 - 91 Analysis of ultraviolet light-induced suppressor mutations in the strain of Escherichia coli K-12 AB1157: an implication for molecular mechanisms of UV mutagenesis; Kato T et al.; Genetic analysis of histidine independent (His+) revertants induced by ultraviolet light in the his-4 E . coli strain AB1157 was carried out: 93% carried ochre (UAA) suppressor mutations and 17% carried back mutations to his+ or (intragenic?) suppressors not detectably separable from his-4 . Using the specialized transducing lambda psu 2int- phage, which carries supE-supB, it was determined that 87% of the ochre suppressors mapped in the supE-supB region . We were able to deduce that 56% of these affected tRNA1Gln by a CAA leads to TAA change in the tRNA gene while 31% affected tRNA2Gln by TAG- leads to TAA change . Although we were unable to deduce the base substitution of the remaining 13%, the results indicate that most of the suppressor mutations are caused by G:C to A:T transition . These results suggest that the high incidence of supE-supB region suppressor mutation in E . coli by UV would be a reflection of the general feature of UV mutagenesis; i.e . preferential induction of G:C to A:T transition in repairing nonpairing DNA lesions . AI 05371 Mol Gen Genet, 1980, 179(2), 311 - 7 Genetic fine structure of the pyrE region containing the genes for ribosomal proteins L28 and L33 in Escherichia coli; Isono K et al.; Temperature-sensitive mutants harbouring alterations in ribosomal proteins L28 and L33 have been isolated and used in mapping the genes coding for the two proteins . It was found that they mapped very close to each other and near pyrE at 80.7 min on the E . coli genetic map . The genes affected by the mutations have been concluded to be the structural genes for proteins L28 (rpmB) and L33 (rpmG) by constructing merodiploids heterozygous for pyrE and for the two ribosomal proteins . Various transduction studies with P1kc phages indicate the gene order in this region to be (rpmB, rpmG)-pyrE-spoT-gltC. Arch Exp Veterinarmed, 1980, 34(2), 235 - 45 {Quantitative makeup of the gastrointestinal flora of piglets in the 1st 2 weeks of life . 2 . The development of the gastrointestinal flora in primary specific-pathogen-free piglets}; Schulze F et al.; Quantitative germ flora analyses were applied to 22 SPF piglets, aged between four hours and 14 days, to follow up the development of their gastro-intestinal flora . The development of a fairly stable gastro-intestinal flora was delayed . Escherichia coli strains were isolated from SPF piglets which had died following diarrhoea and septicaemia, but they did not fall in those E . coli sero-groups known for pathogenicity to swine . The outcome of raising was greatly stabilised and amounted to about 70 per cent by administration of something between 80 ml and 100 ml of radiation-sterilised sow colostrum. Genetika, 1980, 16(7), 1176 - 81 {Role of Escherichia coli K-12 lambda phage receptors in transfection and plasmid transformation}; Likhacheva NA et al.; The dependence of competence of Escherichia coli cells in transfection and plasmid transformation from phage lambda receptor protein was studied . Mal+ variants, sensitive to phage lambda (Mal+ lambda S) were obtained from strains with impaired lambda-phage receptor protein (Mal-lambda R) . Maximum increase of transfection (4.7-fold) was observed in JC411Mal+ lambda S strain . The efficiency of plasmid transformation of pMB9 and RP4 DNAs was also higher in the strain with functioning lambda-receptor protein. Circ Shock, 1980, 7(3), 277 - 87 Myocardial failure and excitation--contraction uncoupling in canine endotoxin shock: role of histamine and the sarcoplasmic reticulum; Hess ML et al.; Subendocardial and subepicardial sarcoplasmic reticulum (SR) were isolated from five groups of dogs following five hours of hemodynamic monitoring: Group 1, 6-8 mg/kg diphenhydramine (n = 5); Group 2, 0.5 mg/kg histamine phosphate, IV bolus; Group 3, 4.0 mg/kg Escherichia coli endotoxin (n = 5); Group 4, 6-8 mg/kg diphenhydramine, followed by 4.0 mg/kg E coli endotoxin (n = 5); and Group 5, time-matched, sham-operated controls (n = 5) . The velocity of calcium uptake and ATP hydrolysis and the integrity of the transport system were determined (coupling ratio = mumoles Ca++/mumoles Pi) . Control SR calcium-uptake velocities averaged 1.13 +/- 0.3 mumoles Ca++/mg-min, with no significant difference between the endocardium and epicardium . SR calcium uptake from the endotoxin shock group averaged 0.64 +/- 0.06 (endocardium) and 0.56 +/- 0.05 (epicardium) mumoles Ca++/mg-min (P < 0.01 from control).ATPase activity from the control group = 1.23 +/- 0.04 mumoles Pi/mg-min; and the endotoxin-shocked group exhibited an activity of 0.99 +/- 0.06, with no significant difference between the endocardial and epicardial populations (P > 0.1) . Diphenhydramine-control SR calcium-uptake rates averaged 1.12 +/- 0.6 mumoles Ca++/mg-min, with no difference between endocardium and epicardium . Diphenhydramine pretreatment plus endotoxin-shock epicardial SR calcium uptake = 0.94 +/- 0.08 mumoles Ca++/mg-min, while the endocardial SR was significantly depressed at 0.72 +/- 0.04 mumoles Pi/mg-min, with no difference between endocardium and epicardium . Bolus histamine infusion resulted in a small but significant depression of both SR calcium-uptake rates (0.93 +/- 0.04 mumoles Ca++/mg-min) and ATPase activity (0.93 +/- 0.04 mumoles Pi/mg-min), with no significant difference between epicardium and endocardium . This study confirms that the calcium transport system of cardiac sarcoplasmic reticulum isolated from endotoxin-shocked animals is depressed . However, this depression is not due entirely to a depression of the Mg++-dependent, Ca++-stimulated ATPase enzyme, but is also associated with a significant uncoupling of ATP hydrolysis from calcium transport . The histamine blocker, diphenhydramine, was only able to protect the epicardial SR; the endocardial SR still exhibited an uncoupling of ATP hydrolysis from calcium transport . Bolus histamine infusion produced a small but significant depression of both calcium transport and ATP hydrolysis . These results are formulate d into a "proton-lysosome" hypothesis that appears to be able to explain excitation-contraction uncoupling in the endotoxin-shocked myocardium. Radiat Environ Biophys, 1980, 18(1), 27 - 36 W-reactivation of phage lambda in X-irradiated mutants of Escherichia coli K-12; Martignoni KD et al.; The survival of UV irradiated phage lambda was increased on X-irradiated E . coli K-12 host cells over that on unirradiated cells . The frequency of c mutants among the surviving phages was to a similar extent increased by the X-ray exposure of the host cells as by UV light . This W-reactivation of phage lambda occurred in uvrA, polA, and recB mutants besides the wild type at about equal X-ray doses, however, at a reduced reactivation efficiency compared with the wild type . W-reactivation was undetectable in recA mutants . While maximal UV induced W-reactivation occurred 30 min after irradiation, the maximal X-ray induced reactivation was found immediately after irradiation . Chloramphenicol (100 micrograms/ml) and nitrofurantoin (50 micrograms/ml) inhibited W-reactivation of phage lambda if added before irradiation of the host cells, indicating the necessity of protein synthesis for W-reactivation. Mol Gen Genet, 1980, 180(1), 147 - 55 Induction of lambdoid prophages by amino acid deprivation: differential inducibility; role of recA; Melechen NE et al.; Lambda prophage in auxotrophic lysogens can be induced by omission of one or combinations of the required amino acids from the culture medium . Such amino acid deprivation can result in nearly as effective induction of lambda as thymine deprivation . Prophage 424 is also induced equally effectively under both conditions although to a lesser extent than lambda . By contrast prophage 21 and lambda i21 are differentially induced effectively by thymine deprivation and virtually not at all during amino acid deprivation . The same differential induction of 21 and equivalent induction of lambda and 424 occur when all three prophages are present in the same lysogen . Increasing the levels of lambda repressor with a cI carrying-plasmid prevented amino acidless induction of lambda as did the lambda ind- mutation . A recA, but not a recB, mutation in the host prevented induction by amino acid deprivation . A recC mutant host showed increased spontaneous induction of lambda and 21 prophages . The findings reported are used as an argument that the recA protease probably is not itself acting as the inducing protease and that a likely source of the observed specificity is an effector molecule . Different effector molecules may be produced in response to different exigent situations, to which the phage repressors may have evolved sensitivity . lambda i80 was inducible both by amino acid and thymine deprivation. Mol Gen Genet, 1980, 179(3), 521 - 6 Coordinate expression of Escherichia coli dnaA and dnaN genes; Sako T et al.; The defects of temperature-sensitive dnaA and dnaN mutants of Escherichia coli are complemented by a recombinant lambda phage, which carries the bacterial DNA segment composed of two EcoRI segments of 1.0 and 3.3 kilobases . Derivatives of the phage, which have an insertion segment of Tn3 in the dnaA gene, are much less active in expressing the dnaN gene function than the parent phage . The dnaN gene activity was determined as the efficiency of superinfecting phage to suppress loss of the viability of lambda lysogenic dnaN59 cells at the non-permissive temperature . Deletions that include the end of the dnaA gene distal to the dnaN gene also reduce the expression of the dnaN gene function . Deletion and insertion in the dnaN gene do not affect the expression of the dnaA gene function . The expression of the dnaN gene function by the dnaA- dnaN+ phages remains weak upon simultaneous infection with dnaA+ dnaN- phages . Thus the insertion and deletion of the dnaA gene influence in cis the expresion of the dnaN gene . We propose that the dnaA and dnaN genes constitute an operon, where the former is upstream to the latter. Mol Gen Genet, 1980, 179(3), 509 - 19 Role of an autorepression system in the control of lambda dv plasmid copy number and incompatibility; Murotsu T et al.; The lambda dv plasmid genome is composed of two regions: (1) the autorepressor region which consists of promoter-operator (pRoR) and autorepressor (tof) and (2) the origin region which consists of the origin of replication (ori) and two initiator genes (O and P) (Matsubara 1976) . Replication of this plasmid is directly connected with transcription from pRoR . Using lambda dvs having various mutations in pRoR, the transcription ability was examined in detail in connection with the control mechanism of replication . The transcription ability of the autorepressor region is controlled by the binding affinity of the tof protein and pRoR . Thus, at steady-state, lambda dvs carrying a highly-constitutive ('strong') pRoR produced the autorepressor at high levels, whereas those carrying a low-constitutive ('weak') pRoR produced the autorepressor at low levels . This relationship did not change even when a fragment of lambda dv genome covering the autorepressor region was cloned into the plasmids pBR322 and pSC138, which could be maintained in a fixed amount within a cell . It was also shown that the autorepressor level at steady-state is a function of copy number of the DNA carrying the region for autorepression . These observations fit the autorepression model of Sompayrac and Maaloe (1973), which predicts that a decreased level of autorepressor activates pRoR and initiates transcription which leads to the production of tof protein until a new steady-state is established . By the same token, if the affinity of autorepressor and pRoR is decreased, pRoR remains active until a higher level of autorepressor is produced . Transcription of the autorepressor region directly affects the level of transcription of the origin region which is located distal to the promoter . Thus, the ability to replicate is connected with an ability to produce autorepressor . The lambda dv plasmids with 'strong' or 'weak' pRoR were maintained at a high or low copy number, respectively . The phenomenon of incompatibility of lambda dv was also examined using pBR322 and pSC138 plasmids carrying the cloned autorepressor region of lambda dv . The chimeric plasmids with 'strong' pRoR exhibited strong incompatibility with lambda dv, whereas those with 'weak' pRoR showed weak incompatibility . This indicates that interaction of the autorepressor and pRoR is related to the incompatibility of lambda dv plasmids. IARC Sci Publ, 1980, (27), 243 - 55 Induction of a stable, heritable epigenetic change by mutagenic carcinogens: a new test system; Toman Z et al.; The expression of the E . coli gal operon was set under the direct negative control of phage lambda repressor by a fusion between the gal operon an the active cI cro segment of phage lambda genoma . This system can exist in two stable but reversible epigenetic states: (A) the immune cI+ cro- gal- state (white colonies on McConkey gal plates) and (B) the nonimmune cI- cro+ gal+ state (red colonies) . Transcription of this gal operon depends upon activation of the PR promoter; hence requiring the removal of lambda immunity repressor (cI) from the oR operator . Short exposure of this E . coli strain to radiation or chemical mutagens/carcinogens leads to a stable, inherited loss of the cI repressor (due to the take-over by the cro repressor, repressing the cI gene) and subsequent constitutive expression of the gal operon . This switch, from the (A) state to the (B) state, depends upon E . coli recA+ and lambda cro+ genes and is reversible upon supply of lambda cI repressor; this is consistent with the fact that cI and cro proteins are mutual repressors, i.e., only one of them can be expressed at a given time . This E . coli strain provides the easiest, most accurate and sensitive assay for all mutagenic and SOS-inducing agents. Mol Gen Genet, 1980, 178(3), 675 - 80 Characterisation of a lambda transducing phage carrying the F conjugation gene traG; Willetts N et al.; A lambda transducing phage carrying the traGSTD genes of the E . coli K12 factor F was isolated by an in vivo technique, and characterized in tra complementation tests, by determining its restriction endonuclease fragment sizes, and by measuring heteroduplex molecules . The size and location on the F physical map of the tra transducing segment was thereby determined . Comparison of the proteins synthesized in UV-irradiated cells by this phage and by a derivative carrying the amber traG79 mutation, allowed the traG product to be identified as a protein of molecular weight 100,000 . In the same experiments, the sizes of the traT and traD products made by the phage were also measured, being 25,000 and 85,000 daltons respectively. Mol Gen Genet, 1980, 178(3), 597 - 601 Second-site rho mutation: genetic linkage and polyC-dependent ATPase; Guterman SK et al.; Rho has been purified to homogeneity from Escherichia coli double mutant rho-115 sur-38 cells, and from rho6 and rho-115 cells . The sur-38 mutation suppresses the original rho-115 phenotype . We observe that the polyC-dependent ATPases of these three rho preparations have the same specific activities . However, the ATPase of rho from the double rho-115 sur-38 mutant is extremely heat labile, while that from rho-115 shows a heat lability intermediate between the wild type and the double mutant . Transduction analysis suggests that sur-38 is closely linked to rho-115 in the order ilv--sur-38--rho-115--metE . These data are consistent with the model that the sur-38 mutation affects the structural gene for rho. Mol Gen Genet, 1980, 178(2), 381 - 9 Isolation and characterization of lambda b221poriCasnA, a plaque-forming specialized transducing phage carrying the origin of replication of the Escherichia coli chromosome; Soll L; A specialized transducing phage lambda b221poriCasnA has been isolated carrying oriC the origin of chromosomal replication of Escherichia coli . All phage genes required for lytic growth are retained, thus the phage is capable of lytic growth . The presence of the oriC locus confers upon infecting phage DNA the ability to replicate as a plasmid using only host DNA replication functions . The presence of both oriC and ansA markers has allowed the development of a plaque assay for origin function which can be used to identify mutants at these loci . Comparison of restriction endonuclease cleavage sites present on lambda b221proiCasnA DNA to those on its parent, lambda b221 rex::Tn10 suggests the steps involved in the formation of the transducing phage. Mol Gen Genet, 1980, 178(2), 317 - 23 Induction of prophage lambda without amplification of recA protein; Baluch J et al.; The requirement for amplified synthesis of recA protein in the UV-promoted induction of coliphage lambda was studied . We confirmed that a low concentration of rifampicin inhibited specifically the increased synthesis of recA protein after an inducing treatment (Satta and Pardee, 1978) . Under these conditions, using an optimal dose of UV, E . coli lysogens were induced, producing active phage . The drug delayed the onset of induction and with increasing concentrations affected the yield of phage, but all the cells lysed . The results established that induction can proceed without amplification of recA protein synthesis. Am Surg, 1980 Jan, 46(1), 14 - 9 Multiple organ failure: clinical and experimental; Eiseman B et al.; The clinical scenario of multiple organ failure (MOF) is reviewed and its frequent correlation with sepsis emphasized . It is hypothesized that MOF is produced by the formation of immune complexes (IC) in response to infection with deposition on organs such as the liver, lung, and kidney . Such immune complexes trap macrophages which can directly damage endothelium . Such a pathologic picture is in keeping with that of MOF . Granular deposits of IgG, IgM, C3, C5, and fibrinogen have been identified in the organs of four patients dying of MOF and sepsis . Similar deposits have been identified using fluorescent antibody stains in the organs of rabbits following cecal perforation . It is hypothesized that sepsis may produce organ failure at a distance from the site of infection via deposits of immune complexes. Physiol Bohemoslov, 1980, 29(1), 81 - 7 Endotoxin-induced changes in the rabbit's blood picture; Konickova Z et al.; The authors studied changes in the rabbit's blood picture in the first 24 hours after the administration of three different doses of endotoxin . The most pronounced changes were observed in the white blood component, particularly the granulocytes, which almost vanished from the blood stream immediately after the endotoxin was injected . In 24 hours granulocytopenia was succeeded by marked granulocytosis . Changes in the lymphocytes were smaller; the lymphocyte count fell slightly about 3 hours after the injection of endotoxin, but by 24 hours it was almost normal again . The platelet count also fell after the administration of endotoxin, but the red blood picture remained virtually the same. Proc Natl Acad Sci U S A, 1980 Jan, 77(1), 167 - 71 Specificity of diffusion channels produced by lambda phage receptor protein of Escherichia coli; Luckey M et al.; The lamB protein, the receptor for phage lambda, was purified from the outer membrane of Escherichia coli K-12 by extraction with Triton X-100 and EDTA, chromatography on DEAE-Sephacel in Triton X-100, exchange of Triton for cholate by gel filtration, and chromatography on Sephacryl S-200 in cholate, NaCl, and EDTA . The purified protein appeared to exist as several oligomeric species . In an equilibrium retention assay with reconstituted vesicles containing phospholipids and lipopolysaccharide, the lamB protein conferred permeability for disaccharides . In a liposome swelling assay designed to measure rates of diffusion, the lamB protein conferred permeability to phospholipid liposomes for a variety of substrates . The rates obtained indicate the permeation facilitated by the lamB protein is specific, discriminating among substrates by both size and configuration . For example, maltose diffused into liposomes 40 times faster than sucrose, about 8 times faster than cellobiose, and about 12 times faster than maltoheptaose . The results suggest that the lamB protein forms a transmembrane channel containing a site (or sites) that loosely interacts with the solutes. Cell, 1980 Jan, 19(1), 143 - 9 Dimeric intermediates of recombination in phage lambda; Chattoraj DK; Biparental lambda phage DNA dimers formed by the Rec recombination system of E . coli were isolated in the absence of DNA replication and phage maturation . The RecA but not the RecB gene is required for dimer formation . Dimers are primarily circular but can also be branched circular or linear . In circular dimers the crossover points are distributed uniformly along the chromosome, even in the presence of the RecB-dependent Chi recombinational hotspots . Thus in the absence of DNA synthesis and maturation, the Rec system can act reciprocally both in the presence and absence of the RecB gene; this lack of RecB participation accounts for the observed lack of Chi activity. J Bacteriol, 1980 Jan, 141(1), 223 - 6 Influence of uvrD3, uvrE502, and recL152 mutations on the phenotypes of Escherichia coli K-12 dam mutants; Marinus MG; The recF143 allele did not alter the phenotypes of dam mutants of Escherichia coli . The uvrD3, uvrE502, and recL152 mutations did alter some of the phenotypes of dam bacteria . It was concluded that the uvrD, uvrE, and recL gene products are involved in the same deoxyribonucleic acid repair pathway as the dam gene product. Zentralbl Chir, 1980, 105(15), 953 - 67 {Developmental and current status of clinical liver transplantation}; Thiede A et al.; Liver transplantation is gradually beginning to move from the experimental to the clinical stage . Of the approx . 340 human "transplantation" which have been carried out worldwide, approx . 250 were performed by the transplantation teams in Denver and Cambridge . They were performed orthotopically . The detailed analysis of the indications by Calne ( n = 81) and Starzl (n = 153) is supplemented by analysis of the course of a total of 223 cases . Individual cases, such as a child with a liver transplant which is functioning for 9 1/2 years, show that liver transplantation is possible . Statistically, however, liver transplantation still involves a big question mark . Nevertheless, the Denver team has announced a 1 year survival quota of almost 50% . In the statistics on the causes of death, technical complications are clearly on the decline . The biliodigestive anastomosis constituted a "locus minoris resistentae", recently, however, the complication rate has been lowered considerably by the use of a Roux-Y-loop bypass and an intermediate gallbladder conduit . Infectious complications - bacterial, fungal and viral - caused or at least promoted by immunosuppression are a main problem . The special immunologic situation of the liver in transplantation has as yet not been clarified either experimentally or clinically . Unequivocal evidence of graft rejection is often difficult, because infectious and drug-induced liver intoxications can produce similar symptoms. Nucleic Acids Symp Ser, 1980, (7), 89 - 98 Solvent extraction method used in separating the protected product of synthetic oligodeoxyribonucleotides; Kuang D; A solvent extraction method for separating synthetic protected oligodeoxyribonucleotides was used in our laboratory based on the lipophilic property of the protecting group of 5'-OH of the oligomers . The extraction of synthetic products protected with MMTr is complete by ether or ether-chloroform (6:1 V/V) for mononucleosides, by chloroform for dinucleoside monophosphates, by dichloromethane:n-butanol (4:1 V/V) for trimer or tetramer, and is nearly complete by dichloromethane:n-butanol (2:1 V/V) for hexamer . The 5'-end phosphorylated nucleotides, oligonucleotides and their symmetrical pyrophosphates remain in water phase . The following synthetic products of protected oligodeoxyribonucleotides have been isolated with this method, all above 85% in purity: (Formula: see text). Nucleic Acids Symp Ser, 1980, (7), 365 - 76 Synthesis of a model promoter for gene expression in Escherichia coli; Dobrynin VN et al.; We have synthesized a 67-membered double-stranded DNA containing putative initiation sites for transcription and translation in E . coli . Among the potential applications of this DNA are construction of artificial genes, cloning of foreign genes in E . coli, and study of structure - activity relations in promoter and ribosome binding sites. J Med Virol, 1980, 6(2), 139 - 45 DNA cloned from the ayw subtype of hepatitis B virus; Price P et al.; DNA from the ayw subtype of hepatitis B virus (HBV) was ligated into the EcorI site of DNA from plasmid pBR322 and propagated in E coli chi 776 . A plasmid with a 3200 base pair insert (pHBV-1) was isolated and the cloned HBV DNA was mapped with restriction endonucleases . Differences were found in restriction endonuclease cleavage sites for DNAs from HBV of subtype ayw and adr. Circ Shock, 1980, 7(4), 413 - 24 The effect of indomethacin and adrenergic receptor blocking agents on rats and canine responses to endotoxin; Goto F et al.; The effect of indomethacin, a prostaglandin (PG) synthesis inhibitor, on the hemodynamics and survival rates of Escherichia coli endotoxin-administered animals (dog and Rat) was studied . Indomethacin post-treatment significantly elevated aortic pressure, cardiac output, and left ventricular isometric tension elevated aortic pressure, cardiac output, and left ventricular isometric tension rise (LVP dp/dt max) following endotoxin administration in the dog . In dogs in a hyperdynamic state due to indomethacin administration treated with phenoxybenzamine (COB) and alprenolol, aortic pressure and cardiac output fell to pre-indomethacin administration values . In reserpine-administered and bilaterally adrenalectomized dogs, hemodynamic states were not altered by indomethacin administration during endotoxin shock . These results suggest that indomethacin potentiates the responses of catecholamines induced by endotoxin shock . Pretreatment with indomethacin alone did not increase the survival rates in endotoxin-administered rats . However, pretreatment and posttreatment with indomethacin combined with POB significantly increased the survival rate over untreated controls (LD 80) given endotoxin alone . Cyclic adenosine monophosphate (cAMP) levels in liver tissue decreased significantly in untreated controls and rats pretreated with indomethacin alone . In contrast, tissue cAMP levels remained within normal values in rats pretreated with indomethacin combined with POB . These results indicate that indomethacin may make a significant contribution as an antishock agent when peripheral circulation is maintained. Microbiol Immunol, 1980, 24(12), 1139 - 49 Restriction endonuclease cleavage maps of the ampicillin transposons Tn2601 and Tn2602; Yamamoto T et al.; This paper reports the cleavage maps of ampicillin transposons Tn2601 and Tn2602, for restriction endonucleases BamHI, PvuII, AvaI, HincII, and HaeII . Both of the transposons are very similar to the well-known ampicillin transposon Tn3 in size, endonuclease cleavage sites, and possession of a short inverted repeat sequence at both ends . A slight difference in the cleavage pattern among these three transposons was observed in the region around the BamHI site which was assumed to be a part of the repressor gene for transposition. Trans R Soc Trop Med Hyg, 1980, 74(5), 653 - 6 The epidemiology of Entamoeba histolytica in Mexico City . A pilot survey I; Sargeaunt PG et al.; Stocks of intestinal amoebae isolated from hospital patients in Mexico City and grown in monoxenic culture were compared among themselves and with those already described (SARGEAUNT & WILLIAMS, 1979), using the electrophoretic patterns of four enzymes: glucose phosphate isomerase (GPI), phosphoglucomutase (PGM), L-malate:NADP+ oxido-reductase (oxalacetate-decarboxylating) (ME) and hexokinase (HK) . New isoenzyme groups (SARGEAUNT & WILLIAMS, 1979) of all the amoebae, including Entamoeba histolytica have been demonstrated . Amongst these have been found seven more groups of E . histolytica, two new groups of E . hartmanni, one new group of Dientamoeba fragilis and one new group of E . coli . Of the seven new groups of E . histolytica three are known to originate from patients with clinical amoebiasis whilst the remainder are from asymptomatic subjects . Only 11.2% of the 125 isolations were associated with clinical amoebiasis, and these are clearly distinguished from the isolations from asymptomatic patients by their electrophoretic isoenzyme pattern. Mol Gen Genet, 1980, 180(2), 487 - 8 Direct selection of DNA inserts in plasmid gene of kanamycin-resistance; Slutsky AM et al.; In this paper we propose a method of direct selection for hybrid DNA molecules in paromomycin-dependent E . coli cells. Mol Gen Genet, 1980, 180(2), 267 - 73 Identification of the dnaA and dnaN gene products of Escherichia coli; Yuasa S et al.; A specialized transducing lambda phage carrying the dnaN genes of Escherichia coli specifies two proteins of about 41 and 48 kilodaltons (kd) . The temperature-sensitive mutations, dnaN59 and dnaA167, were found to result in altered isoelectric points of the 41 and 48 kd proteins, respectively . Thus the dnaN gene product was identified as a weakly acidic 41 and 48 kd protein . The synthesis of the dnaN gene product is greatly reduced by insertion of a transposon Tn3 in the dnaA gene and by deletion in the gene at the distal end to the dnaN gene . Temperature-sensitive dnaA mutations, on the dnaN gene product . These results indicate that the synthesis of the dnaN gene product is dependent on the structural integrity of the dnaA gene. Mol Gen Genet, 1980, 179(2), 391 - 7 The structure of unstable constitutive revertants of mutant galOP-308::IS2-I; Delius H et al.; The isolation and characterization of three unstable and constitutive revertants of mutant galOP-308 of E . coli is described . In this mutant an IS2 element is integrated between the promoter and the first structural gene of the galactose operon, and exerts a strong polar effect on the expression of the three galactose genes . In the three revertants under investigation it was observed that relief of polarity and constitutive expression of the gal-operon were accompanied by the deletion of 90% of the IS2 sequence and of various lengths of the adjacent sequences including the gal-promoter . We conclude from this result that the transcription termination signals causing strong polarity were located on the deleted part of IS2, and that in our revertants the galactose genes are now under the control of a new promoter which is apparently unstable. Mol Gen Genet, 1980, 179(2), 369 - 72 Plasmid vectors derived from phage Mu allow direct selection of transformants containing cloned HindIII and PstI fragments; Schumann W et al.; The vector plasmids pKN001 and pKN80 both contain the EcoRi.C fragment of E.coli phage Mu DNA which codes for a killing function that is efficiently expressed upon transformation into Mu-sensitive bacteria . By in vitro insertion of HindIII fragments at the single HindIII site of pKN80 or of PstI fragments at the single PstI site of pKN001 the killing function is inactivated . The resulting plasmids have a selective advantage over the religated vector when transformed into Mu-sensitive bacteria . More than 90% of the transformations contain hybrid plasmids . These results show the usefulness of Mu DNA containing plasmids pKN001 and pKN80 as vectors that allow the direct selection for recombinant plasmids. Mol Gen Genet, 1980, 179(2), 289 - 97 Localization of the plasmid (pKM101) gene(s) involved in recA+lexA+-dependent mutagenesis; Shanabruch WG et al.; Twenty Tn5 insertion mutants of the drug resistance plasmid pKM101 have been isolated that are unable to enhance mutagenesis with ultraviolet (UV) irradiation or methyl methanesulfonate . By restriction mapping, the Tn5 insertion in each of these pKM101 mutants was shown to be within a 1.9 kb region of the plasmid genome . We have termed this segment of the pKM101 map the muc (mutagenesis: UV and chemical) gene(s) . Characterization of these mutants indicated that any Tn5 insertion within the muc gene(s) abolished the ability of pKM101 to: (a) enhance spontaneous, UV and chemical mutagenesis, (b) increase host survival following UV-irradiation, (c) increase the survival of UV-irradiated phage plated on irradiated or unirradiated cells, and (d) suppress the repair and mutagenesis deficiencies of a umuC- mutant . Possible models to explain the role of the pKM101 muc gene(s) in mutagenesis and repair are discussed. Genetika, 1980, 16(11), 1947 - 57 {Restriction and electron microscopic analyses of deletion derivatives thermosensitive with respect to maintaining plasmid pEG1}; Danilevich VN et al.; Temperature-independent deletion mutants of temperature-sensitive in self-maintenance plasmid pEG-1, derived from R-factor RP4, are mapped using the restriction endonucleases PstI, SmaI, EcoRI, BamHI and the heteroduplex analysis . The pEG1 derivatives under study are found to have deletions in the area of ampicillin transposon Tn1 and nearby genes . The left and the right ends of these deletions boundaries are localized between 37.5 MD and 7.6 MD in the RP4 map . Thus far, the area of plasmid RP4 (37.5-7.6 MD) with Tn1 and, presumably, inc gene(s) in it does not have any genes needed for stable maintenance of R-factor . A conclusion is made that the gene RP4, which carries the mutation determining thermosensitive character of pEG1 maintenance and of inhibition of the cell growth, is localized between the EcoRI site and transposon Tn1 at a distance less than 1.0 MD from the latter. Genetika, 1980, 16(10), 1741 - 52 {Certain properties of transcribed fragments of the mouse genome cloned in plasmid pBR322}; Tokarskaia ON et al.; Clones of total mouse DNA efficiently hybridized with mRNA (or cDNA) were selected by colony hybridization technique . The majority of selected fragments demonstrate hybridization with cDNA, dsRNA-B (isolated from pre-mRNA) and oligo(dT) . The data obtained indicate that the base sequences hybridizing to these test-probes are contiguous within several individual cloned restriction DNA fragments . At least in two cases sequences hybridizing with cDNA belong to repetitive fraction of the mouse genome (presumptive repetitive structural genes) . They are transcribed effectively, and respective mRNAs of abundant type . Two other clones contain structural genes which are expressed into mRNAs of non-abundant type. Zentralbl Bakteriol Naturwiss, 1980, 135(6), 461 - 6 Detection of polyphosphates and enzymes of polyphosphate metabolism in Bdellovibrio bacteriovorus; Bobyk MA et al.; Bdellovibrio bacteriovorus cells, parasitizing in E . coli, contain a considerable amount of inorganic polyphosphates, 55% of the total pool of which is due to the most polymeric acid-insoluble polyphosphates . B . bacteriovorus contains enzymes participating both in the synthesis and consumption of polyphosphates, i.e . 1,3-diphosphoglycerate: polyphosphate phosphotransferase, polyphosphate glucokinase, polyphosphatase, tripolyphosphatase, pyrophosphatase, acid and alkaline phosphatases . The possible role of high-molecular polyphosphates in the vital activity of the bacterial parasite B . bacteriovorus is discussed. Mol Gen Genet, 1980, 179(1), 75 - 80 The ral gene of phage lambda . II . Isolation and characterization of ral deficient mutants; Debrouwere L et al.; The lambda ral function modulates the restriction and modification activities of the Escherichia coli K12 and B restriction enzymes (Zabeau et al., 1980) . In order to further analyse this function, ral deficient mutants have been isolated, using a method which exploits the property of the strong mutagen N-methyl-N'-nitro-N-nitrosoguanidine (N.G.) to induce multiple closely linked mutations . Hence, mutagenized phages carrying mutations in one locus were frequently found to contain additional mutations in adjacent loci . This very efficient mutagenesis procedure enabled us to isolate 27 independent Ral deficient mutants . Seven mutants were found to affect the ral gene directly and were located between the genes N anc cIII . Detailed mapping of two of these mutants showed that the lambda ral gene is located at position 70.6-70.9% on the physical map . The isolation and characterization of these mutants further supports the conclusion that ral is a gene different from the N gene, and demonstrates that the ral gene product is responsible for both counteracting restriction and enhancing modification. Mol Gen Genet, 1980, 179(1), 211 - 6 Genetic organization and restriction enzyme cleavage map of the ksgA-pdxA region of the Escherichia coli chromosome; Andresson OS et al.; Small multicopy plasmids carrying the Escherichia coli genes ksgA and pdxA were constructed by ligation in vitro of an EcoRI restriction fragment from lambda ksg10 (Andresson and Davies, 1980a) into the EcoRI sites of the ColE1 plasmids RSF2124 and pVH51 . Cleavage maps of the plasmids were determined for 21 different restriction enzymes . The ksgA gene was located in a 750 basepairs (bp) region 1,450 bp clockwise of the EcoRI site in folA: pdxA is in a 2,040 bp region immediately clockwise of ksgA. Genetika, 1980, 16(7), 1199 - 1203 {Relation between Escherichia coli K-12 viability and mutability and the balance between DNA and protein synthesis . III . Relation between disruptions in the balance between DNA and protein synthesis and mutagenesis and viability during thymidine deprivation of thy- cells defective with respect to recB and polA genes}; Fradkin GE et al.; The phenomenon of metabolic mutagenesis is found to be determined by stabilization of metabolic breaks in DNA chains, being linked with disbalance of intracellular synthesis of DNA and protein . The rate of metabolic mutagenesis observed in case of the DNA-protein synthesis disbalance due to thymine starvation is influenced by cell genotype . The lack of exonuclease V in recB-thy- cells decreases (reduces) the rate of metabolic mutagenesis and does not effect the viability . The lack of DNA polymerase I activity in polA-thy- cells causes a sharp increase in the metabolic mutagenesis rate and a parallel sharp drop in the survival under thymine starvation, as compared to cells with polA+thy- genotype. Genetika, 1980, 16(6), 985 - 93 {Study of a pts-gene-linked pleiotropic mutation influencing expression of catabolyte-sensitive genes of Escherichia coli K-12}; Burd GI et al.; Properties of the pleiotropic mutation pts17 are described . This mutation is liked to pts1 gene, which specifies the synthesis of the enzyme I of phosphoenolpyruvate-dependent phosphotransferase system (PTS) in Escherichia coli K-12 . Genetic analysis has shown that pts17 mutation is located between purC and pts1 markers and that the wild type allele pts17+ has transdominant character over the mutant allele pts17 . The mutant strain J6217, isogenic to parent J62, shows normal growth properties in the minimal salt media with a number of carbohydrates used as a single carbon source . The pts17 mutations does not affect the enzyme I activity, but significantly suppresses the total PTS activity in the bacterial cell extracts . The intact mutant cells reveal the enhanced rate of accumulation and phosphorylation of alpha-methylglucoside . The pts17 bacteria show 3-fold enhanced phosphohydrolase activity with glucose-6-phosphate as substrate . It is established that pts17 mutation decreases the differential rate of the L-tryptophanase synthesis and makes the process of unductions resistant to glucose catabolite repression . It is suggested that this mutation affects the activity of the PTS factor III . One can suppose that the latter mediates the influence of ptsI and ptsH mutations upon the expression of catabolite-sensitive operons in E . coli. Antonie Van Leeuwenhoek, 1980, 46(4), 353 - 62 Persistence of the pBR 322 plasmid in Escherichia coli K 12 grown in chemostat cultures; Wouters JT et al.; Populations of a Escherichia coli K 12 strain, containing the vector plasmid pBR 322, were grown in chemostat culture under glucose- and phosphate-limited conditions . Resistance to tetracycline and ampicillin were lost after prolonged cultivation, resulting in the production of apparent plasmid-free populations which were more competitive than the original population . This competitiveness between plasmid-free and plasmid-containing populations was greatest in environments where the nutrient restriction was severe . Also during sequential subcultivation in batch cultures loss of plasmid was observed. Mol Gen Genet, 1980, 180(1), 91 - 7 Tn1 generated mutants in the mercuric ion reductase of the Inc P plasmid, R702; Summers AO et al.; Physiological, biochemical and genetic aspects of resistance to inorganic mercury compounds were examined in a group of mercury sensitive derivatives generated in the Inc P plasmid, R702, by Tn1 insertion . Strains carrying each of these insertion mutations had no detectable mercuric ion reductase, were more sensitive to mercuric ion than a plasmidless strain, and exhibited inducible uptake of Hg2+ . These characteristics indicate that the mutants are altered in the Hg(II) reductase . This hypothesis was supported by complementation and recombination analysis with known point and deletion mutations in the mer operon of the Inc FII plasmid, R100 . Such experiments showed that the eight insertions studied had occurred in four distinct regions of the Hg(II) reductase structural gene (merA) . Complementation data also demonstrated that the regulatory protein determined by the R702 plasmid has no effect on the expression of the micro-constitutive Hg(II) reductase activity expressed by merR mutants of R100. Mol Gen Genet, 1980, 180(1), 213 - 7 Interactions between the F conjugal transfer system and CloDF13::Tna plasmids; Willetts N; It was confirmed that all the F transfer genes required for the formation of stable mating pairs, including traN and traG, are essential for transfer of the two small multicopy plasmids ColE1 and cloDF13, whereas the traM, traI and traZ genes that are required for F conjugal DNA metabolism, are not . Differences between ColE1 and CloDF13 were that the F traD gene was needed for transfer of ColE1 but not of CloDF13, and that R100-1 efficiently transferred CloDF13 but not ColE1 . A copy number mutant of CloDF13 inhibited F transfer and reduced plaque formation by the F-specific RNA phage f2, but not by Q beta or by the single-strand DNA phage f1 . This phenotype suggests that the inhibition system (FinC) acts on traD, mutations in which give a similar phenotype . Hybridisation experiments with lambda tra phage DNA showed that transcription of traD was not reduced, and FinC probably inhibits function of the traD product rather than its synthesis . FinC-insensitive Flac mutants were isolated and characterised . One was shown to have an uppromoter mutation resulting in increased transcription of traJ and hence of the traY leads to Z operon including traD: the raised level of the traD product presumably then counteracted FinC inhibition. Mol Gen Genet, 1980, 180(1), 123 - 7 Isolation of an IS1 flanked kanamycin resistance transposon from R1drd19; Clerget M et al.; We have isolated and identified an IS1-flanked transposon from the plasmid R1drd19 . This transposon specifies resistance to kanamycin and is 10.4 kg long . It exhibits a frequency of transposition two orders of magnitude lower than that of the smaller, IS1-flanked transposon Tn9 . We have named it Tn2350. Mol Gen Genet, 1980, 180(1), 115 - 21 Genetic and physical mapping of recF in Escherichia coli K-12; Ream LW et al.; Two factor transductional crosses place recF at approximately 82 min on the E . coli chromosome; recF is highly cotransducible with dnaA and gyrB (cou) . Transductional analysis with a series of lambda tna specialized transducing phages carrying chromosomal DNA from the tnaA region place recF between dnaA and gyrB . This analysis also indicates that a gene lying in the same region and producing an easily detectable protein (estimated MW of 45 kD) is dnaN and not recF. Mol Gen Genet, 1980, 179(3), 661 - 7 Involvement of DNA gyrase in rRNA synthesis in vivo; Wahle E et al.; The effects of oxolinic acid and novobiocin, two known inhibitors of DNA gyrase, on in vivo transcription in E . coli were investigated . The drugs inhibit the incorporation of 3H-uridine into RNA . It is shown that the effect is due to a direct influence of DNA gyrase on transcription, independent of interference with replication . By the use of rifampicin and hybridization experiments it was found that treatment with intermediate concentrations of DNA gyrase inhibitors reduces the rate of rRNA synthesis to a smaller extent than the rate of total RNA synthesis . By following the completion of growing rRNA chains we have also obtained evidence indicating that the average rate of rRNA chain growth is decreased in cells treated with inhibitors of DNA gyrase. Mol Gen Genet, 1980, 179(3), 615 - 25 Construction of pBR322-ara hybrid plasmids by in vivo recombination; Horwitz AH et al.; In vivo recombination was used to clone deletions of the araBAD-araC genes of Escherichia coli onto a hybrid pBR322-ara plasmid . Genetic and physical analyses demonstrated that the desired deletions had been recombined onto the plasmid . In addition to permitting a detailed physical analysis of various ara deletions, this procedure has generated a series of plasmid cloning vehicles that can be used to clone, by in vivo recombination, any ara point mutation located within the region covered by the deletions . Hybrid plasmids containing the cloned point mutation can be distinguished from the original cloning vehicle by genetic complementation . The desired recombinant plasmid can be easily obtained because the frequency of recombination between the plasmid ara region and the chromosomal ara region is 0.025%--3% . A plasmid containing a deletion which removes the ara controlling site region and the araC gene was used to clone two types of araBAD promoter mutations and an araC mutation by in vivo recombination . Genetic and physical analysis of these plasmids established that the mutations in question had been recombined on to the ara deletion plasmid . The application of this procedure to the ara genes and to other genetic systems is discussed. Mol Gen Genet, 1980, 179(3), 573 - 80 Plasmid cloning vectors that can be nicked at a unique site; Bishop JO et al.; We describe ColEl-type plasmids, with relaxed DNA replication, based on pMB9, and carrying the CmR determinant of R1, in addition to the TcR determinant of pMB9 . One of the plasmids, pPH207, has unique sites for EcoRI, HindIII, BamI, SalI and HpaI . Insertion of foreign DNA into all but the last of these inactivates either the CmR or the TcR determinant . The original CmR TcR plasmid (pCM2) contains a copy of IS1 which produces deletions to left and to right . Most of these inactivate either the CmR or the TcR determinant . An internal 280 bp deletion of IS1 DNA in pPH207 greatly reduces the frequency at which deletions are observed . The main feature of these plasmids is a site that is cleaved by some preparations of EcoRI in only one strand of the DNA duplex (the EcoRIn site) . This site facilitates strand separation of sequences inserted at the HindIII, BamI and SalI sites of the TcR gene, and also of any inserted at the true EcoRI site by a method that destroys that site . Since the orientation of the EcoRIn site is known, the orientation of sequences inserted at the neighbouring sites can be easily determined . Plasmid pPH207 is not mobilised by a Hfr, but its mobilisation is promoted by ColEl . It is therefore Mob- bom+ . Experiments with minicells show that it directs the copious synthesis of chloramphenicol transacetylase. Mol Gen Genet, 1980, 179(3), 547 - 54 The origin of Q-independent derivatives of phage lambda; Kaiser K; lambda qsr' (Q-independent) phages are characterised by the replacement of the region of the lambda genome that contains Q, S, R, and the late gene promoter, P'R, with host-derived DNA that codes for functions analogous to those deleted . Restriction endonuclease analysis and DNA/DNA hybridisation methods have been used to show that lambda p4 and lambda qin A3, two such Q-independent phages, are the product of recombination between lambda and a defective lambdoid prophage (the qsr' prophage) located at an as yet unidentified site in the E . coli K 12 chromosome . The qsr' prophage is distinct from the defective lambdoid prophage Rac (Kaiser and Murray 1979) . In the E . coli K12 strain AB1157 from which lambda qsr' phages cannot be generated, the qsr' prophage has suffered an internal deletion . That the qsr' prophage appears not to carry a full complement of essential late genes suggests one explanation for its apparently defective nature. Physiol Chem Phys, 1980, 12(1), 51 - 5 Interaction of sulfur-containing radioprotectors with DNA: a spectrophotometric study; Vasilescu D et al.; The interaction between sodium-compensated DNA and several aminothiol radioprotectors {cysteamine; methyl-2-cysteamine; cysteamine phosphorothioate; N-(2-mercaptoethyl) 1,2-diaminoethane; N-(2-mercaptoethyl)-1,3-diaminopropane; N-(3-aminopropyl)-2-aminoethyl phosphorothioic acid} has been studied by spectrophotometry . In all cases, elevation of the melting point (Tm) of the DNA-radioprotector complex was observed . The interaction of these ionized aminothiols with phosphate groups of DNA is essentially an electrostatic one, like that for metallic cations, and can be expressed by the Schildkraut-Lifson equation Tm = a log Cradio + b, where a and b are adjustable parameters and Cradio is the concentration of the radioprotectors. Membr Biochem, 1980, 3(1-2), 131 - 46 H + -substrate cotransport by the melibiose membrane carrier in Escherichia coli; Tsuchiya T et al.; Proton entry into anaerobic Escherichia coli in response to the addition of HCl was measured by monitoring pH changes in the external solution . Preincubation of cells in a Na+ -free medium containing melibiose or methyl-alpha-galactoside (alpha MG) stimulated the rate of H+ entry in response to the acid pulse . This melibiose- or alpha MG-dependent proton pathway appeared to be identical to the melibiose carrier, since the channel was only observed in melibiose-induced cells . Furthermore, this membrane pathway for protons showed the same temperature sensitivity as the melibiose carrier (active at 30 degrees but inactive at 37 degrees) . These observations are consistent with the idea that the melibiose transport system provides a pathway for protons in the presence of appropriate substrates, but that the pathway is closed to protons in the absence of the sugar . Such observations indicate that there is an obligatory coupling between H+ flux and melibiose or alpha MG flux through the carrier when Na+ is omitted from the incubation medium. Hemoglobin, 1980, 4(3-4), 497 - 507 The organization of the gamma-delta-beta gene complex in normal and thalassemia cells; Bank A et al.; Restriction enzyme digestion analysis and direct human globin gene cloning have permitted analysis of the physical arrangement of nucleotide sequences within and surrounding the human globin genes . With these methods it has been shown that the linear arrangement 5' to 3' of the globin genes is G gamma-A gamma-delta-beta . The G gamma and A gamma genes are separated by about 3.5 kilobases (kb), while the A gamma and delta genes are 15 kb apart, and the delta and beta 6.5 kb apart . Each of these genes contains a large intervening sequence (IVS) of approximately 1 kb in precisely the same position between condons 104 and 105 . In addition, each of these genes has a small IVS between codons 30 and 31 . In homozygous delta beta thalassemia DNA, there is deletion of all of the normal delta and beta gene fragments . However, a new fragment 4.2 kb in size containing the 5' end of the delta globin gene is retained . Retention of this fragment in delta beta thalassemia, but not in HPFH is consistent with a role for sequences in this region for limiting gamma globin gene expression . Studies to date suggest that the beta + and beta 0 thalassemias will be due to a heterogeneous group of DNA defects affecting either beta globin gene transcription or beta mRNA processing . In most cases of beta + and beta 0 thalassemia DNA analyzed, there is no detectable deletion of beta or delta genes . In three India beta 0 patients, deletion of the 3' end of the beta gene has been found . Analysis of cloned beta globin genes from a patient with beta + thalasseia shows differences from normal in the fragments generated by restriction enzymes which cut frequently . Whether these differences are responsible for the defect in thalassemia or are polymorphisms unrelated to thalassemia remains to be determined. Microbiol Immunol, 1980, 24(6), 479 - 94 Gene expression of ampicillin resistance transposons, Tn2601 and Tn2602; Yamamoto T et al.; To establish the mode of gene expression specified by transposon, we investigated the correlation among the homology of the DNA sequence, the extent of transposon-specific transcription, the specific activity of penicillinase (PCase) per cell, and the transposition frequency by using two ampicillin resistance transposons (TnAs), Tn2601 and Tn2602 . Although both the TnAs specify the so-called type I PCase, Tn2602 always conferred 10- to 20-fold higher PCase activity per cell than Tn2601 regardless of the kind of replicon carrying TnA . The transposition freuency of Tn2602 also was 8 to 50 times higher than that of Tn2601 in all combinations of donor and recipients plasmids examined . As a result, the transposability expressed by the TnA was thought to correlate with the productivity of PCase in the cell specified by the corresponding TnA . The level of TnA-specific transcription of Tn2602 was noticeably higher than that of Tn2601, whereas the two TnAs shared a high degree (more than 90%) of DNA sequence homology . These results suggest that the difference in rates of transcription of the two transposons plays a key role in determining the difference in the productivity of PCase and the transposition-protein(s) of Tn2601 and Tn2602. Dermatologica, 1980, 161(4), 227 - 32 A serological study of herpes simplex virus type 1 antibody over a 13-year period; Ratner JJ et al.; HSV-1 serum antibody titers determined by 50% plaque reduction and confirmed by radioimmunoassay in 11 samples from an individual over a 13-year period indicated a significant increase between the first sample and a sample taken 9 years later . This increase did not seem to reflect loss of antibody in the low titered serum sample due to storage. Eur J Biochem, 1980, 108(1), 223 - 31 Lactose carrier protein of Escherichia coli . Structure and expression of plasmids carrying the Y gene of the lac operon; Teather RM et al.; The previously described hybrid plasmid pC7 which carries lacI+O+delta(Z)Y+A+ on a 12.3 X 10(6)-Mr DNA fragment {Teather et al . (1978) Mol . Gen . Genet . 159, 239-248} was partially digested with the restriction endonuclease EcoRI under conditions reducing the recognition sequence to d(A-A-T-T) and ligated to the vector pB322 . lac Y-carrying inserts of various sized (Mr 1.5-4.7 X 10(6)) were obtained . Hybrid plasmid pTE18 (2300-base-pair insert) carries part of the I (repressor) gene, the promotor-operator region, part of the Z (beta-galactosidase) gene, the Y (lactose carrier) gene and part of the A (transacetylase) gene . Upon induction of pTE18-harbouring strains the Y-gene product is expressed at a nearly constant rate for several generations and accumulates to a level of 12-16% of the total cytoplasmic membrane protein . Integration into the membrane leads to active carrier as judged by binding and transport measurements. Can J Microbiol, 1980 Jan, 26(1), 94 - 101 Consequences of interaction between F plasmid and a drug-resistance plasmid belonging to incompatibility group F1; Katz L et al.; Two plasmids, pLK1 and pLK2, were derived from pIP218, an in vivo recombinant of plasmid F and the drug-resistance plasmid pIP176 (Cmr, Smr, Sur, Tcr) . Of these two plasmids, pLK1 is 70 Mdaltons and carries the Tc-resistance determinant in a 7-Mdalton transposition element; pLK2 is 125 Mdaltons and carries Cm-, Sm- and Su-resistance determinants . The plasmid pLK1 resulted as a Tc-resistance segregaant of PIP218 during its coexistence with another plasmid, Co1E1-araC101, and pLK2 (125 Mdaltons) as a CmrSmrSur segregant during the conjugal transfer of pIP218 . Both plasmids belong to the F1-incompatibility group, surface-exclude each other and Flac, and are derepressed for transfer . Incompatibility studies also indicated the preferential maintenance of pLK2 in hosts carrying either pLK2 and pLK1, or pLK2 and F'lac . An explanation of this phenomenon is provided . Furthermore, our data suggest the illegitimate recombination of the chromosomal lac genes with pLK1 . In course of the incompatibility studies, the tet determinant was transposed from pLK1 into the chromosome, from the chromosome into the lac genes of an Flac plasmid, and from the Flac plasmid into another site on a second Flac plasmid. Folia Microbiol (Praha), 1980, 25(3), 201 - 6 Simultaneous induction of three catabolic enzymes in Escherichia coli; Pavlasova E et al.; During a simultaneous induction of three enzymes which are subject to catabolite repression (beta-galactosidase, tryptophanase and amylomaltase, or beta-galactosidase, tryptophanase and D-serine deaminase) in a batch culture, the rates of synthesis of beta-galactosidase and tryptophanase decreases, while the rates of synthesis of amylomaltase and D-serine deaminase remain unaffected . The addition of cAMP brings about a considerable increase of the rate of synthesis of D-serine deaminase and a partial synthesis rate increase of beta-galactosidase whihle the synthesis rate of tryptophanase remains lowered and the synthesis rate of amylomaltase remains unaffected . In a continuous culture beta-galactosidase, tryptophanase and D-serine deaminase are synthesized simultaneously at a maximum rate without mutual influence . The addition of cAMP increases the rate of synthesis of all three enzymes. Ann N Y Acad Sci, 1980, 343, 425 - 32 The structure of rat preproinsulin genes; Lomedico PT et al.; In rat there are two nonallelic insulins, I and II . We have cloned and sequenced double stranded cDNA copies of both preproinsulin mRNA I and II . Using the cloned sequence as probe, we established by the Southern blotting technique a restriction map of the two chromosomal genes . This map indicates that an intron exists within the insulin II gene . To examine this in more detail, we have isolated both genes from a library of rat DNA cloned in phage lambda . Restriction endonuclease analysis and direct DNA sequencing revealed that gene II contains two introns: a 490 base pair intron between the region encoding amino acids 38 and 39 of proinsulin, and a 119 base pair intron, which is 17 base pairs upstream from the initiation codon . Gene I is not interrupted within the protein coding region, but possesses an intron homologous to the 119 base pair intron of insulin II . We are studying the structure of insulin genes from other species to determine if the 490 base pair intron was lost or inserted in the duplicated gene . We have identified nuclear RNA molecules larger than preproinsulin mRNA which contain the transcribed intronic sequences . These molecules represent a new precursor in insulin biosynthesis. Mol Gen Genet, 1980, 178(3), 717 - 8 Molecular cloning of EcoRII endonuclease and methylase genes; Kosykh VG et al.; The genes for restriction-modification system EcoRII have been cloned from plasmid N3 DNA using RSF2124 as a vector plasmid . The hybrid plasmids designated pFK321 and pFK322 contained a 5.8 megadaltons EcoRI--fragment derived from N3 DNA including the genes for restriction-modification system EcoRII and a gene for resistance to sulfanilamide. Mol Gen Genet, 1980, 178(3), 655 - 61 Complementation of T4 phage am mutations by hybrid phages lambda-T4; Vorozheikina D et al.; EcoRI fragments of the T4 cytosine-containing DNA (dC-DNA) were cloned in the lambda XIII vector phage carrying the only restriction site for EcoRI in the repressor gene of lambda . 38 genes of T4 were identified in the cloned fragments by means of marker rescue technique . All cloned early genes and some late genes of T4 were able to complement a corresponding am mutations of T4 phage when nonpermissive cells of E.coli were simultaneously infected with hybrid phages lambda-T4 and am mutants of T4 . An average burst size for am mutants from su- cells (when complemented by corresponding hybrid phage) was 20-70 pfu for early genes and 1-3 to 20 pfu for late ones . When the extract of cells infected with hybrid phage lambda-T4-22 containing T4 genes 57, 1, 2, 64 was mixed with the extract of cells infected with T4N51 mutant, the complementation in vitro was observed . So, it was shown that normal product of late gene 2 is synthesized in the cells infected with hybrid phage lambda-T4-22 in the absence of positive regulators of transcription coded by early T4 genes. Mol Gen Genet, 1980, 178(2), 475 - 7 Construction and properties of a new cloning vehicle, allowing direct screening for recombinant plasmids; Ruther U; pUR2, a certified B2(EK2) vector, allows easy isolation of variants containing cloned EcoRI-fragments . Bacteria harboring plasmids without inserts make blue colonies on indicator-plates, whilst those harboring recombinant plasmids make white colonies. Mol Gen Genet, 1980, 178(2), 471 - 3 Does the insertion element IS1 transpose preferentially into A+T-rich DNA segments? Meyer J, Iida S, Arber W. IS1-mediated insertion and deletion formation occur preferentially into A+T-rich regions of DNA of bacteriophate P1 and of the r-determinant of the R plasmid NR1 . The significance of this correlation is discussed in view of other published data. Mol Gen Genet, 1980, 178(2), 367 - 74 Deletions and an inversion induced by a resident IS1 of the lactose transposon Tn951; Cornelis G et al.; DNA-DNA filter binding tests, "Southern" blotting experiments and DNA heteroduplex analysis clearly show that Tn951 contains an IS1 element . This IS1-951 sequence is peculiar in that it does not contain the PstI cleavage site which is usually observed on E . coli derived IS1 elements . Nonetheless, IS1-951 induces deletions . This process is temperature dependent . One instance of an IS1-951 induced inversion was observed, the structure of which is compatible with the current models of transposition of IS elements. Mol Gen Genet, 1980, 178(2), 343 - 9 Isolation of a polynucleotide phosphorylase mutant using a kanamycin resistant determinant; Portier C; Insertion in an episome of a kanamycine-resistant element (Tn5) at the polynucleotide phosphorylase gene level, results, after transduction into a wild strain, by the loss of activities specific to polynucleotide phosphorylase . A low phosphorolytic activity is nevertheless detectable in crude extracts, but no longer in extracts slightly purified after heat treatment at 54 degrees C . The part played by other enzymes in these activities is discussed . Bacterial growth is not affected by introduction of the mutation. Mol Gen Genet, 1980, 178(2), 281 - 4 IS4 is still found at its chromosomal site after transposition to galT; Klaer R et al.; IS4-DNA has been hybridized to separated DNA fragments of E . coli K12 strain M28 and to three mutants caused by transposition of IS4 to galT . The parental strain shows one band hybridizing to IS4 representing one copy of IS4 in the chromosome . The mutants have this copy retained and show in addition a second band corresponding to the IS4 copy in galT . The experiments support the hypothesis that transposition of IS4 is accompanied by replication of the element. Chromosoma, 1980, 77(2), 203 - 15 Arrangement of coding and non-coding sequences in the DNA molecules coding for rRNAs in Oxytricha sp . DNA of ciliated protozoa . VII; Swanton MT et al.; All of the genes in the macronucleus of Oxytricha sp . occur on physically separate "gene-sized" DNA molecules . We have inserted the DNA molecule that codes for rRNA into a bacterial plasmid in order to study its structure and function . Using restriction nuclease mapping and hybridization of 125I-rRNAs to gel separated DNA fragments we have determined that the intact rDNA is 8,140+/-50 base pairs (bp) in length . Reading from one end, the molecule consists of approximately 1,540 bp of non-coding DNA, approximately 2,100+/-50 bp that code for 19S rRNA, approximately 3,700+/-50 bp that code for 25 rTNA, and approximately 620+/-50 bp of non-coding DNDA . The 5.8S rRNA coding sequence (approximately 150 bp) occurs at one end of the 25S RNA coding region but which end is not known yet . All three rRNAs are encoded in the same strand of the DNA molecule, and transcription is in the order: 19S leads to 25S. Arzneimittelforschung, 1980, 30(3a), 558 - 69 Viruses as tools for studies on the molecular biology of mammalian cells; Doerfler W et al.; 1 . Multiple copies of intact adenovirus type 12 (Ad12) DNA are integrated into the DNA of Ad12-transformed hamster and Ad12-induced rat brain tumor cells . Free viral DNA is not present in the Ad12-transformed lines investigated . 2 . Only few sites of integration are found in Al2-transformed hamster and Ad12-induced rat brain tumor cells . Integration may have occurred into repetitive cellular sequences at selective sites . These sites may be different in different cell lines, however, none of these sites has been analyzed in sufficient detail . 3 . Three lines of Ad12-induced rat brain tumor cells exhibit identical patterns of integration . These lines have been derived from three brain tumors in one animal and may have evolved from the same transformed cell . 4 . In Ad12-induced rat brain tumor cells early and late segments of the viral genome are expressed as polysome-associated messenger RNA . 5 . In human cells productively infected with adenovirus type 2 (Ad2), a large number of viral genome copies are linked to cellular DNA early postinfection . There are only a few sites of recombination (illegitimate?) which probably lie in repetitive cellular DNA sequences . The functional significance of this frequent recombination is unknown. Mol Gen Genet, 1980, 177(4), 667 - 74 Genetic evidence for absence of transposition functions from the internal part of Tn981 a relative of Tn9; Reif HJ; Inverse transposition of the DNA of pBR322 was found to be mediated by the small transposon Tn981 a relative of Tn9 flanked by direct repeats of IS1 . Since the resulting structure IS1::pBR322::IS1 (Tn983) is transposed in a second step in the absence of Tn981, it is concluded that all the functions necessary for transposition of IS1 flanked transposons are coded for by IS1 itself or the E . coli chromosome, respectively. Mol Gen Genet, 1980, 177(4), 597 - 601 Effect of DNA sequences adjacent to the termini of Tn3 on sequential translocation; Tu CP et al.; Insertion of Tn3 generates a five base pair repeat of a nucleotide sequence indigenous to the recipient genome . Tn3 promoted deletions extend precisely from the Tn3 terminus and remove one of the 5 base pair repeats while not affecting the ability of Tn3 to subsequently undergo translocation . A direct repeat of a 10 bp sequence located in the Tn3 termini occurs internally within Tn3 and may affect the orientation of insertion. Yale J Biol Med, 1980 Jan-Feb, 53(1), 61 - 9 Hepatitis viruses: characterization and diagnostic techniques; Dienstag JL; Two human hypatitis viruses have been identified and characterized, but one or more additional agents exist . Hepatitis B virus (HBV) is a complex 42-nm predominantly double-stranded DNA virus with distinct surface and core antigens and an endogenous DNA polymerase . Hepatitis A virus (HAV) is a 27-nm RNA virus with enterovirus-like properties . Progressively more sensitive and specific immunologic assays have been applied to the study of viral hepatitis and are available for routine diagnostic purposes . As a result we recognize distinct serologic response patterns to infection, new antigenic markers, biochemical-biophysical characteristics of the viruses, and their epidemiologic features . Recombinant DNA technology has permitted the cloning of HBV genetic material and gene products in E . coli, but the virus has not been cultivated in vitro . In contrast, successful in vitro cultivation of HAV has finally been accomplished . Application of sensitive serologic tests for HAV and HBV has revealed that "non-A, non-B" agents account for a substantial proportion of transfusion-associated hepatitis as well as hepatitis occurring in the absence of percutaneous exposure . These agents have been transmitted to chimpanzees, and several putative virus antigen-antibody systems have been described; however, a specific association between these virus antigens and non-A, non-B hepatitis has not been established. Res Vet Sci, 1980 Jan, 28(1), 44 - 50 The effect of Escherichia coli endotoxins and adrenocortical hormones on plasma enzyme activities in the domestic fowl; Curtis MJ et al.; The intravenous injection of endotoxins isolated from Escherichia coli serogroups O111 and O78 (2 mg/kg) increased the activities of aspartate transaminase and lactate and sorbitol dehydrogenases in the plasma of six- to 11-week-old chickens during the next 24 h . These changes were compared with those produced by adrenocorticotrophic hormone and beta-methasone and were attributed to tissue damage involving the liver followed by increased enzyme synthesis which may have been induced partly by adrenocortical hormones . Further evidence of liver damage was provided by a fall in the activity of cholinesterase . The alkaline phosphatase activity gave no indication of cholestasis. Res Vet Sci, 1980 Jan, 28(1), 123 - 7 The effect of Escherichia coli endotoxins on the concentrations of corticosterone and growth hormone in the plasma of the domestic fowl; Curtis MJ et al.; The intravenous injection of chickens aged six to 11 weeks with Escherichia coli endotoxins (serogroups O111 and O78) produced a large increase in the plasma corticosterone concentration which was maximal (five to 10-fold) after 1 h and still evident after 8 h . It did not vary with the dose over the range 0.1 to 2 mg/kg and was smaller than that produced by adrenocorticotrophic hormone (ACTH) (20 iu/kg) . A decrease in growth hormone concentration was detected between 1 and 2 h after endotoxin administration in six- to seven-week-old birds, this change being opposite to that which occurs in man. Mol Gen Genet, 1980 Jan, 177(2), 301 - 9 Requirement of DNA gyrase for the initiation of chromosome replication in Escherichia coli K-12; Filutowicz M; It has been found that strains carrying mutations in the dnaA gene are unusually sensitive to COU, NAL or NOV, which are known to inhibit DNA gyrase activities . The delay in the initiation of chromosome replication after COU treatment has been observed in cells with chromosomes synchronized by amino acid starvation or by temperature shift-up (dnaA46) . The unusual sensitivity of growth to COU of the initiation mutant runs parallel to a higher sensitivity to the drug of the initiation of chromosome replication . The double mutant, dnaA46, cou-110 has been isolated and mutation cou-110 conferring resistance of growth, initiation and elongation of chromosome replication to COU was mapped in the gene coding for the subunit of DNA gyrase . The reduced frequency of appearance of the mutants resistant to COU, NAL, or NOV in the initiation mutant suggests that some mutations in genes coding for DNA gyrase subunits cannot coexist with the dnaA46 mutation . The possible mechanisms of the requirement of DNA gyrase for dnaA-dependent initiation of E . coli chromosome are discussed. Eur J Biochem, 1980 Jan, 103(2), 219 - 26 Studies on the mechanism of transcription of nucleosomal complexes; Wasylyk B et al.; The mechanism of transcription by Escherichia coli RNA polymerase holoenzyme of chromatin assembled in vitro has been studied by two approaches . Using digestion with endodeoxyribonuclease EcoRI as a probe of mobility, it was found that nucleosome movement is slow compared to the time taken for RNA polymerase to transcribe through regions organised into nucleosomes . However, transcription leads to at least some displacement of nucleosomes relative to their original site on the DNA . In the second approach chromatin was reconstituted from extensively crosslinked histone octamers and simian virus 40 DNA . RNA chain elongation on this template is inhibited relative to non-crosslinked chromatin . This can be related to a decrease in the ability of the cross-linked histone octamers to dissociate from the DNA. Proc Natl Acad Sci U S A, 1980 Jan, 77(1), 313 - 7 Organization of the recA gene of Escherichia coli; Horii T et al.; The restriction map of a BamHI DNA fragment that contains the recA gene of Escherichia coli has been established and a large portion of the fragment's nucleotide sequence has been determined . The coding region of the recA gene contains 1059 nucleotide residues and encodes a single protein of 353 amino acid residues . The amino acid sequence of the first five residues of the NH2 terminus of the recA protein agrees with the sequence predicted from the DNA sequence except for the absence of formylmethionine in the purified protein . Immediately after the coding sequence, there is a G+C-rich sequence with dyad symmetry followed by an A+T-rich sequence . These could signal termination of transcription . The site of initiation for synthesis in vitro of the recA messenger RNA has been determined by analysis of the 5' nucleotide sequence of {gamma-32P}ATP-labeled transcripts . The promoter region shos a high degree of symmetry and contains sequences commonly found in recognition and binding sites for RNA polymerase. Proc Natl Acad Sci U S A, 1980 Jan, 77(1), 262 - 6 Isolation of a replication origin complex from Escherichia coli; Nagai K et al.; A complex consisting of replicative origin DNA and several proteins was isolated from Escherichia coli . Cells of temperature-sensitive mutants were labeled at the origin and fractionated by sucrose gradient centrifugation . A complex highly purified in origin DNA sedimented as a unique band . This complex dissociated at high concentration, above 0.2 M KCl . Upon dialysis, the complex reformed, allowing further purification of its constituents . Three major protein bands were found, corresponding to proteins of the outer membrane . The complex did not sediment with membrane fractions, but adhered to the outer membrane in the presence of magnesium. Proc Natl Acad Sci U S A, 1980 Jan, 77(1), 210 - 4 Cloning DNA sequences from influenza viral RNA segments; Lai CJ et al.; DNA sequences corresponding to gene segments that code for the nonstructural protein, the matrix protein, and the hemagglutinin of influenza A virus {strain A/Udorn/72 (H3N2)} were cloned in Escherichia coli pBR 322 . Initially, positive and negative cDNA strands were prepared separately by reverse transcription . The positive strands of cDNA were transcribed from genomic RNA segments by using a specific dodecamer DNA sequence as a primer; the negative strands of cDNA were transcribed from cytoplasmic viral mRNA segments by using an oligo(dT) primer . DNA duplexes corresponding in size to the virus RNA segments were then purified, inserted into the plasmid DNA, and used for transformation of E . coli . The influenza virus-specific DNA sequences isolated from recombinant plasmid molecules were characterized by mapping restriction enzyme cleavage sites . In addition, the orientation of cloned DNA was determined with reference to the 3' terminus of viral RNA. Proc Natl Acad Sci U S A, 1980 Jan, 77(1), 107 - 11 Double-stranded RNA inhibits a phosphoprotein phosphatase present in interferon-treated cells; Epstein DA et al.; In accord with previous studies, (I)n . (C)n, a potent inhibitor of the cell-free protein-synthesizing system of interferon-treated L cells, stimulates incorporation of 32P from {gamma-32P}ATP into the 67,000-dalton protein, P1 . The double-stranded RNA (I)n . (br5C)n, which is inactive as an inhibitory of protein synthesis, does not stimulate phosphorylation of P1 under conditions approximating those of protein synthesis . However, we have found conditions under which (I)n . (br5C)n is approximately as effective as (I)n . (C)n in stimulating incorporation of label from {gamma-32P}ATP into 67,000-dalton protein . Upon transfer of labeled P1 from these conditions to those compatible with protein synthesis, there is a time-dependent decrease in label in the 67,000-dalton protein . This decrease is more rapid in the presence of (I)n . (br5C)n than in the presence of (I)n . (C)n . This differential decrease is also observed when 32P-labeled extracts are diluted into buffer containing 10 mM ATP, hexokinase and 1 and M glucose, or Escherichia coli alkaline phosphatase . A partial proteolytic digest of P1 labeled in the absence of double-stranded RNA or in the presence of (I)n . (C)n or (I)n . (br5C)n gives rise to similar peptide patterns . These results suggest that dephosphorylation as well as phosphorylation determines the net incorporation of 32P into P1 . Moreover, these results suggest the existence of a phosphatase activity that may be inhibited more strongly by (I)n . (C)n than by (I)n . (br5C)n. Gene, 1980 Jan, 8(2), 163 - 77 Alteration of the specificity of restriction endonucleases in the presence of organic solvents; Malyguine E et al.; The specificity of XbaI, SalI, HhaI, PstI, BamHI and SstI is relaxed in the presence of an organic solvent, such as 20% glycerol or 8% dimethylsulfoxide (DMSO) . This alteration, very pronounced in some cases, requires an excess of enzyme, varies from one kind of enzyme to another and is highly dependent on the pH, the ionic strength, the nature of the metallic cofactor and/or the presence of a second organic solvent . Preliminary data concerning XbaI and BamHI used under conditions where the relaxation of specificity is moderate, suggest that some of the new ("pseudo") sites correspond to shortened sequences derived from the normal recognition sequence cleaved under the standard conditions of the reaction. Gene, 1980 Jan, 8(2), 153 - 62 Isolation of transposon TnA from plasmid RP4 carrying two copies of this element; Dobritsa AP et al.; Employing heteroduplex and restriction analyses, two inverted copies of a 3.2.10(6) dalton transposable sequence, TnA, were found in RP4::TnA, a spontaneously arisen derivative of the plasmid RP4 . Integration of the second copy of TnA causes loss of the conjugative properties of RP4 . Both TnA sequences in RP4::TnA were localized and found to have opposite orientations . The DNA fragment corresponding to the individual transposon TnA was isolated after the endonuclease S1 digestion of RP4::TnA molecules annealed under conditions favoring intramolecular renaturation . The attempts to transform the cells of Escherichia coli QD5003, HB101{pCRI} and JC7623 with the isolated transposon were unsuccessful. Cell, 1980 Jan, 19(1), 151 - 60 Translocation specificity of the Tn3 element: characterization of sites of multiple insertions; Tu CP et al.; 247 independent events involving insertion of the TN3 transposable element into a 4 kb constructed plasmid (pTU4) of partially known DNA sequence were studied by restriction endonuclease mapping, and 65 of these insertion sites were examined further by DNA sequence analysis . Our results show that the previously proposed regional specificity for Tn3 insertion is associated with a strong preference for AT-rich segments as insertion sites . Moreover, multiple insertions of the Tn3 occurred at certain AT-rich nucleotide positions, and 23 of 26 independent insertion events at a single nucleotide position were found to be in the same orientation . A region of the recipient plasmid showing major homology with the terminal 18 bp of Tn3 was identified in the vicinity of an 11 nucleotide segment that included three insertional hot spots and 36 independent insertions . Our results indicate that the site and orientation of insertion of Tn3 are at least partly determined by the primary nucleotide sequence of the recipient genome, and suggest that insertional hot spots may result from the combined effects of AT richness plus homology of the recipient genome with the terminal sequences of Tn3. Antibiotiki, 1980 Jan, 25(1), 28 - 32 {Biological activity of a new Soviet natural inducer, double-stranded RNA}; Fomina AN et al.; Antiviral activity of a two-spiral RNA (ts RNA), a new natural interferon inductor was studied . It was shown that ts RNA extracted from a phage infected E . coli culture was an active inductor of interferon and resistance to infection with the forestspring encephalitis virus experimental animals . In experiments on 10-12 g mice ts RNA administered in a dose of 50 micrograms/mouse 6 hours after the infection induced up to 1280 units/ml of the serum interferon . When the inductor was administered repeatedly, the experimental animals developed hyporeactivity resulting in a marked decrease in interferon production after the 3rd subsequent injection . The most pronounced effect with respect to the forest-spring encephalitis virus was observed when the inductor was administered intraperitoneally in a dose of 20 micrograms/mouse 4 hours before the infection . The protective effect was less pronounced when the inductor was administered 24 and 48 hours before the infection . A two-fold administration of the inductor did not increase the antiviral effect . When the inductor was administered in a dose of 100 micrograms 14 days before the infection, the animals showed an increase in the nonspecific resistance to the infection resulting in a marked antiviral effect. J Bacteriol, 1980 Jan, 141(1), 87 - 99 Cloning of replication, incompatibility, and stability functions of R plasmid NR1; Miki T et al.; The region of R plasmid NR1 that is capable of mediating autonomous replication was cloned by using EcoRI, SalI, and PstI restriction endonucleases . The only EcoRI fragment capable of mediating autonomous replication in either a pol+ or a polA host was fragment B . SalI fragment E joined in native orientation with the part of SalI fragment C that overlapped with EcoRI fragment B, and also two contiguous PstI fragments of sizes 1.6 and 1.1 kilobases from EcoRI fragment B-mediated autonomous replication . When these individual SalI fragments were cloned onto plasmid pBR313 or the individual PstI fragments were cloned onto plasmid pBR322, none of these single fragments could rescue the replication of the ColE1-like vectors in a polA host, even in the presence of a compatible "helper" plasmid derived from a copy mutant of NR1 . In contrast to the results reported for closely related R plasmid R6, EcoRI fragment A of NR1 could not rescue the replication of ColE1 derivative RSF2124 in a polA(Am) mutant or in a polA(Ts) mutant at the restrictive temperature . Although capable of autonomous replication, EcoRI fragment B of NR1 (or smaller replicator fragments cloned from it by using other restriction enzymes) was not stably inherited in the absence of selection for the recombinant plasmid . When EcoRI fragment B was ligated to EcoRI fragment A of NR1, the recombinant plasmid was stable . Thus, EcoRI fragment A contained a stability (stb) function . The stb function did not act in trans since EcoRI fragment B was not stably inherited when a ColE1 derivative (RSF2124) ligated to EcoRI fragment A was present in the same cell . A cointegrate plasmid consisting of EcoRI fragment B of NR1 ligated to RSF2124 was also not stably inherited, whereas only EcoRI fragment B was unstable when both RSF2124 and EcoRI fragment B coexisted as autonomous plasmids in the same cell . The incompatibility gene of NR1 was shown to be located within the region of overlap between SalI fragment E and the PstI 1.1-kilobase fragment . A copy mutant of NR1 (called pRR12) was found to have greatly reduced incompatibility with NR1; this Inc- phenotype is cis dominant. J Bacteriol, 1980 Jan, 141(1), 413 - 6 A stable plasmid carrying the yeast Leu2 gene and containing only yeast deoxyribonucleic acid; Toh-e A et al.; The plasmid pSLe1 is a deletion derivative of the yeast-Escherichia coli hybrid plasmid pJDB219, obtained by HindIII digestion, ligation, and transformation directly into Saccharomyces cerevisiae . pSLe1 has only yeast sequences; it contains one of the inverted repeated sequences of plasmid 2muDNA and the LEU2 gene . pSLe1 is stably maintained in yeast cells without selective pressure . pSLe1 is about half as large as 2muDNA, but pSLe1 does not displace the normal 2muDNA. J Bacteriol, 1980 Jan, 141(1), 405 - 8 Genetic analysis of Escherichia coli mutants defective in adenylate kinase and sn-glycerol 3-phosphate acyltransferase; Esmon BE et al.; Complementation analysis with independently isolated plA and adk (adenylate kinase) mutants of Escherichia coli showed that all the mutants belong to the same complementation group . The results suggest that the adk (plsA) locus is the structural gene for adenylate kinase. J Bacteriol, 1980 Jan, 141(1), 397 - 400 Isolation and properties of calmodulin from Dictyostelium discoideum; Clarke M et al.; A calcium-dependent regulatory protein (calmodulin) was purified from vegetative amoebae of Dictyostelium discoideum . The properties of Dictyostelium calmodulin are similar but not identical to those of bovine brain calmodulin . Calmodulin activity was not detected in extracts of Saccharomyces cerevisiae or Escherichia coli. Folia Microbiol (Praha), 1980, 25(1), 16 - 23 Effect of cyclic adenosine-3',5'-monophosphate on the simultaneous synthesis of beta-galactosidase and tryptophanase in Escherichia coli; Pavlasova E et al.; When inducing simultaneously beta-galactosidase and tryptophanase in a batch culture either the synthesis of tryptophanase or of both enzymes is decreased due to an insufficient cAMP concentration . The addition of this nucleotide can overcome this decrease . In a continuous culture both enzymes are synthesized at the maximum rate, as the amount of cAMP produced during carbon limitation of growth is probably sufficient for the simultaneous synthesis of both enzymes . In the beta-galactosidase hyperproduction mutant cultivated continuously the level of beta-galactosidase markedly decreases when tryptophanase is simultaneously induced . Also this decrease is caused by cAMP insufficiency and can be overcome by increasing its concentration . cAMP is thus an important regulatory factor of both enzymes and becomes a limiting factor in their simultaneous synthesis; a competition for this regulatory compound apparently occurs and probably also a different mutual affinity of the regulatory complex with the promoter site of the enzyme operons is involved. Biochim Biophys Acta, 1980, 606(1), 113 - 24 Large-scale purification of two forms of active lac operator from plasmids; Kallai OB et al.; A practical procedure is described for obtaining milligram quantities of a small (29 nucleotide) Eco RI restriction fragment of DNA containing the Escherichia coli lac operator . A yield of 10--15 mg of operator is obtained from 1 kg of wet cell paste . The resultant operator is shown to be homogeneous and competitively active in filter assays . Two separable but interconvertible forms of lac operator exist in solution, probably linear duplex and hairpin isomers . Only the presumed linear form is active in binding lac repressor by competition assay, but the two isomers are interconvertible by heating to 80 degrees C . The methods described here should be generally applicable for purifying other restriction fragments from plasmids. J Supramol Struct, 1980, 14(4), 405 - 22 Averages of glutamine synthetase molecules as obtained with various skin and electron dose conditions; Kessel M et al.; Averaged projections of individual glutamine synthetase molecules have been obtained by using electron microscopy and image processing . The methodology of correlation averaging under low dose conditions is described in detail . Because of their low signal-to-noise ratio, images made under low dose conditions cannot be directly interpreted in terms of high resolution features . Computer averaging of these images reveals a division of the subunit projection into two domains whose sizes agree with results of Lei et al {2} limited proteolysis experiments. Mol Biol (Mosk), 1980, 14(1), 212 - 22 {Structure of nuclear pre-mRNA . XIII . Hybridization properties of triphosphorylated 5'-end fragments}; Peunova NI et al.; Triphosphorylated 5'-end fragments about 100 nucleotides long were prepared from purified nuclear pre-mRNA using a modified hydroxyapatite method . These fragments as well as fragments of total pre-mRNA were polyadenylated by ATP:RNA adenyl-transferase and used as templates for the synthesis of {32P}cDNA by reverse transcriptase in the presence of an oligo(dT)-primer, cDNA transcribed from total fragments of pre-mRNA and from 5'-end fragments (5'-cDNA) were hybridized with excess of nuclear pre-mRNA . The extent of hybridization was 65-70 and 80-85% in different experiments . 18% of total cDNA and 35% of 5'-cDNA hybridized with mRNA from polysomes . A high homology between mRNA and triphosphorylated 5'-ends of pre-mRNA may be explained in the terms of splicing . The sequences adjacent to the triphosphorylated 5'-ends of pre-mRNA represent a specific class with complexity about 2.10(5) nucleotides . Less than 30% of 5'-cDNA hybridized with intermediately repetitive DNA, while the main portion hybridized with unique DNA sequences . About 15% of 5'-cDNA contain oligo (dA) sequences, originated from oligo (U) in the pre-mRNA. Circ Shock, 1980, 7(4), 387 - 98 Effects of endotoxin on microvascular flow velocity and indicator dispersion; Baker CH; The effects of endotoxin (3mg/kgLD100) on the microcirculation of exposed mesentery were studied in anesthetized cats (0.7 kg) . A femoral artery and vein were cannulated for arterial pressure determination and injections . Successive bolus injections (0.05 ml) of blood containing sulphhemoglobin red blood cells (SH-RBC) and fluorescein isothiocyanate-labeled dextran (FITC-Dextran) were made into a mesenteric artery branch . The indicator passage through the microvessels was recorded on videotape . Upon replay, the outputs of an injection signal and two video sampler (VS) intensity-sensitive windows (placed at each end of the vessel) were monitored for obtaining indicator time-concentration curves . The arteriolar flow velocity was calculated as the distance between windows (millimeters) divided by the difference in mean transit time (t) of the two curves . Vessel dimensions were determined as the calibrated distance between the windows . During the first hour postendotoxin, the arterial pressure decreased while arterioles (35 micrometer and larger) and venular diameters increased . Terminal arteriole (20-micrometer)diameters decreased . SH-RBC and FITC-Dextran velocities decreased 50%, t increased, and indicator dispersion increased . Arterial pressure increased to above control levels during the next two hours and 55-micrometers and 35-micrometers arteriolar and venular diameters decreased, and 20 micrometers arterioles increased; SH-RBC and FITC-Dextran flow velocities gradually decreased; arteriolar t increased markedly; and indicator disp