Mutat Res, 1990 Sep, 242(1), 57 - 65 Polyomavirus-based shuttle vectors for studying mechanisms of mutagenesis in rodent cells; Zernik-Kobak M et al.; We have constructed a series of polyomavirus-based shuttle vectors for analyzing mechanisms of mutagenesis in rodent cell systems . These vectors contain the supF suppressor tRNA gene which serves as the mutagenesis target; the pBR327 replication functions and ampr gene for replication and selection in bacteria; and the polyomavirus genome which permits replication in rodent cells . The polyoma genomes used in these vectors vary in their enhancer regions, causing varying efficiencies of replication in different types of rodent cells . One of the vectors (pPySLPT-2) which replicates particularly well in several different rodent cell types (i.e., Chinese hamster ovary, mouse hepatoma and mouse lymphoma) was used to compare mutation induction by UV radiation in UV repair-deficient mouse lymphoma L5178Y-R cells with mutagenesis in the related UV repair-proficient line, L5178Y-S . In both cell types, UV-induced mutants could be recovered at frequencies up to 50-fold higher than that of the spontaneous background . At a given UV fluence the L5178Y-R cells were more highly mutable than the L5178Y-S cells . Our results indicate that these new polyomavirus-based vectors should be useful for analysis of the molecular mechanisms of mutation induction in rodent cell systems, and in particular should allow detailed analysis of mutagenesis in the well characterized rodent somatic cell mutants. Virology, 1990 Sep, 178(1), 232 - 7 Identification of two additional v-sea-encoded proteins in avian erythroblastosis virus, S13-infected fibroblasts; Knight J et al.; Rabbit antibodies prepared against a v-sea-encoded polypeptide expressed in bacteria were used to characterize the v-sea-encoded proteins in cells transformed by the avian erythroblastosis virus, S13 . In addition to the two previously described v-sea-encoded proteins, gp155 and gp70, two additional proteins were identified of molecular weights 38,000 and 36,000 Da . Interestingly, these two proteins were found only in fibroblasts infected with the S13 virus and not in S13-transformed erythroid cells . These two proteins were phosphoproteins, but, unlike the two previously characterized v-sea-encoded proteins, they did not appear to be modified by the addition of N-linked sugars . Possible mechanisms for the biosynthesis of these two new proteins are discussed. Cancer Res, 1990 Sep 1, 50(17 Suppl), 5658S - 5667S A human hepatocellular carcinoma 3.0-kilobase DNA sequence transforms both rat liver cells and NIH3T3 fibroblasts and encodes a 52-kilodalton protein; Yang SS et al.; Neoplastic transformation of rat liver cells in vitro by DNA-mediated gene transfer with an oncogene, hhcM, derived from human (Mahlavu) hepatocellular carcinoma, is described and compared with that of NIH3T3 cells . hhcM was cloned in a neomycin-resistant simian virus 40 promoter vector (pNeor/S) and was designated pNrpM-1 . BRL-1 or NIH3T3 cells, transfected with pNrpM-1 DNA, showed significant morphological changes, loss of contact inhibition, and anchorage-independent growth . They became highly tumorigenic in nude rats and nu/nu mice . Control BRL-1 and NIH3T3 cells, whether transfected with pNeor/S DNA or not, remained contact inhibited and nontumorigenic . Both the transformants and the tumor cells contained integrated hhcM DNA as shown by Southern blot hybridization . The complete nucleotide sequence of the hhcM 3.0-kilobase DNA was also determined, and it consisted of a possible open reading frame for a protein of 52 kilodaltons (467 amino acids) . The high-level production of a slightly modified form of this 52-kilodalton protein in a bacterial expression system has been successfully achieved . The bacteria-produced protein was similar in electrophoretic behavior to the 52- to 53-kilodalton protein synthesized in a cell-free translation system using rabbit reticulocyte lysate programmed with hybrid-selected hhcM-specific mRNA from Mahlavu hepatocellular carcinoma cells. Nichidai Koko Kagaku, 1990 Sep, 16(3), 361 - 7 {Non-specific immunosuppressive effect induced by A . actinomycetemcomitans}; Ochiai K et al.; Previous studies have shown that immunosuppressive effects are related to the pathogenicity of periodontopathic bacteria and the development of periodontal disease . We reported soluble sonic extracts (SE) from A . actinomycetemcomitans and B . intermedius had a strong immunosuppressive effect on primary response of anti-SRBC plaque forming cells . SE from A . actinomycetemcomitans inhibited the IgM----IgG isotype switching . The purpose of this study was to investigate the effect of SE on secondary immunoresponse . As a control, mice (C3H/HeN) were immunized with intraperitoneal injection of SRBC and complete Freund's adjuvant, and additional SRBC after 30 days . In order to study the effect of SE from A . actinomycetemcomitans on secondary response, four groups were prepared in this study . One group of C3H/HeN mice were injected SE intravenously before the primary immunization of SRBC . The other three groups were given SE at different time on secondary injection of SRBC and designated the pre-, post-, or simultaneous injection, respectively . Hemolytic plaque assay was performed and estimated anti-SRBC plaque forming cells in each immunoglobulin class and IgG subclass, on the 5th day after the secondary injection . The immunosuppressive effect was found in all the groups which we examined . The present study strongly suggests that periodontopathic bacteria have strong adjuvant activity, and long-term Actinobacillus infection accompanied by periodontal fluctuation in bacterial flora may induce aberration in the immune system . The suppressed immune system explain the explosive growth of bacteria tested in our investigation, resulting in the mixed or opportunistic infection by bacteria harbored in the gingival crevice. Nutrition, 1990 Sep-Oct, 6(5), 347 - 56 Clinical use of total nutritional admixtures; Campos AC et al.; The administration of a single mixture of the components of total parenteral nutrition (TPN) constitutes total nutritional admixture (TNA), the safety and efficacy of which in a variety of clinical settings have been confirmed by controlled trials . According to the nitrogen balance and stable isotope methods, TNA is as efficacious as the old system of three bottles with piggyback intravenous fat emulsion in maintaining body nitrogen mass, visceral protein, and liver function . Also, serum concentrations of electrolytes, trace elements, and vitamins can be maintained adequately using the TNA system . The other advantages are the timesaving to the nursing staff, with its hidden savings in cost; the avoidance of a peripheral catheter solely for the infusion of lipid emulsion in addition to the central catheter for TPN in hospitalized patients; and the facility of use in home nutrition programs . The ease of home use has resulted in a greater degree of patient compliance; thus patients receive a mixed-fuel system while avoiding the hazards of a piggyback infusion, with all its potential complications . Among the perceived disadvantages of TNA are a supposed higher frequency of catheter-related sepsis, a view based on in vitro studies that is not borne out by in vivo studies; catheter occlusion by precipitation of calcium salts; and enhanced ability to clear fat and thus fat tolerance with continuous infusion of lipids . Numerous studies have shown that these concerns are unwarranted. Kanagawa Shigaku, 1990 Sep, 25(2), 209 - 20 {Immunobiological activities of Veillonella parvula isolated from infected root canals}; Nagashima Y; The primary etiological agent of all periapical lesions has long been considered to be bacterial . Furthermore, bacteria from infected root canals are potential antigens capable of initiating immunological reactions in periapical tissues . The purpose of this study, therefore, was clarify the immunological potentials of Veillonella parvula (V . parvula), which was frequently isolated from root canals with periapical lesion . Immunobiological activities of V . parvula sonic extracts were investigated on the enhancement of monocytes migration, induction of interleukin-1 (IL-1) production, mitogenicity and polyclonal activation of B cell . Following results were obtained: 1 . Both LPS and protein of V . parvula sonic extracts strongly enhanced the activity of human peripheral monocytes migration . 2 . Induction of IL-1 on C3H/HeN mice macrophage by V . parvula sonic extracts were stronger than that of S . typhimurium LPS as positive control . 3 . It was found that mitogenicity of LPS from V . parvula on splenocytes was stronger than that of the protein, however mitogenicity on thymocytes was not shown in both preparation . 4 . The polyclonal activation of B cell on splenocytes of BALB/c nu/nu mice by V . parvula was induced by the protein and LPS . 5 . These findings indicate that both the protein and LPS from V . parvula have a regulation of immunobiological responses against macrophages and lymphocytes. Ther Drug Monit, 1990 Sep, 12(5), 419 - 26 Impact of a clinical pharmacokinetic service on patients treated with aminoglycosides: a cost-benefit analysis; Destache CJ et al.; In a prospective, randomized study, 75 adults receiving aminoglycosides were followed by a clinical pharmacokinetic service and 70 followed as controls . The two groups were similar in age, gender, height, and APACHE II score . A cost-to-charge ratio was used to derive direct costs of hospitalization and calculate cost-benefit . Excluded from this comparison were patients with incomplete acceptance of pharmacokinetic service recommendations and patients followed by other clinical pharmacists . Pharmacokinetic service patients had shorter hospitalizations (322.67 +/- 270.28 h; controls 442.89 +/- 536.81, p = 0.087) and febrile periods (50.05 +/- 79.38 h; controls 92.23 +/- 122.50, p less than 0.05) . More pharmacokinetic service patients had adequate peak levels . Pharmacokinetic service direct costs were lower ($7,102.56 +/- 9,898.19; controls $13,758.64 +/- 22,874.31, p less than 0.05) . Calculated direct cost of the service was $85.00/patient . Annual savings for 500 patients is $2,220,540.00. Khirurgiia (Mosk), 1990 Sep, (9), 65 - 8 {Treatment of suppurative diseases of soft tissues by CO2 laser and immobilized trypsin}; Tolstykh PI et al.; The results of treatment of 245 patients with purulent diseases of the soft tissues are discussed . The course of the wound process was most favourable with the use of immobilized trypsin on gauze in the management of wounds formed after surgical debridement of purulent foci by means of CO2 laser . The method made it possible to accelerate the processes of necrolysis, provide a stable low level of dissemination of bacteria in the wound tissues, reduce the term of preparation of the wound for the application of secondary sutures and the terms of healing. Kekkaku, 1990 Sep, 65(9), 569 - 74 {Isolation of a strain of M . tuberculosis which is considered to be rifampicin-dependent, from a patient with long-lasted smear positive and culture difficult (SPCD) mycobacteria}; Nakamura M et al.; During the course of clinical examination of drug sensitivity tests for M . tuberculosis, a strain of M . tuberculosis which is considered to be rifampicin-dependent was isolated from a patient with persisting smear positive, culture negative (SPCN) or culture difficult (SPCD) mycobacteria status . The strain isolated produced a few tiny colonies on the control Ogawa-egg yolk medium, whereas it showed abundant growth like a bacteria plaque on the medium containing rifampicin 50 micrograms/ml . Furthermore, the growth of the strain on Ogawa medium containing rifampicin 50 micrograms/ml is much better than that on the medium containing rifampicin 10 micrograms/ml. JPEN J Parenter Enteral Nutr, 1990 Sep-Oct, 14(5 Suppl), 170S - 174S Nutrition and translocation; Alexander JW; It is now clear that atrophy of the intestinal mucosa can occur rapidly after injury and that the degree of atrophy is quantitatively related to the severity of injury . Such atrophy can be associated with translocation of bacteria and endotoxin, which can trigger the hypermetabolic response and induce a septic state, which may ultimately lead to multiple system organ failure . Early enteral feeding following trauma can prevent atrophy of the intestinal mucosa and is associated with a decrease in the hypermetabolic response and the incidence of septic complications and diarrhea . Enteral feeding of complete diets can also improve outcome with other forms of intestinal injury such as gamma irradiation or cytotoxic drugs . In contrast, total parenteral nutrition and elemental enteral diets are associated with atrophy of the intestinal mucosa and increased translocation . The addition of glutamine and/or fiber to elemental diets may decrease translocation in some but not all circumstances . It is now clear that enteral nutrition can influence the incidence and severity of translocation, which in turn can potentially reverse or prevent the adverse effects of injury and inflammation in traumatic injury and serious illness. J Clin Microbiol, 1990 Sep, 28(9), 1877 - 80 Detection and identification of Mycobacterium tuberculosis by DNA amplification; Pao CC et al.; The polymerase chain reaction (PCR) was used to identify mycobacterial DNA sequences in uncultured clinical specimens . Two oligonucleotide primers derived from the sequence of a gene that codes for the 65-kilodalton antigen of Mycobacterium tuberculosis amplified DNA from all 11 species of mycobacteria tested . Amplified DNAs of nontuberculosis mycobacteria were found to be approximately 20 to 40 bases shorter than those from M . tuberculosis and Mycobacterium bovis BCG . DNA equivalent to that present in as few as 40 M . tuberculosis cells either alone or in the presence of DNA equivalent to that in 10(6) human cells could be detected . Results from analysis of cultured bacteria and clinical specimens showed PCR was sensitive and specific both in detecting mycobacteria and in differentiating M . tuberculosis and BCG from other species of mycobacteria . The PCR method with the primers reported here may become a useful tool in the early and rapid detection of mycobacterial infections in uncultured clinical specimens. EMBO J, 1990 Sep, 9(9), 2959 - 67 Self-association of the Drosophila zeste protein is responsible for transvection effects; Bickel S et al.; The zeste gene product is required for transvection effects that imply the ability of regulatory elements on one chromosome to affect the expression of the homologous gene in a somatically paired chromosome . The z1 mutation causes a pairing dependent inhibition of the expression of the white gene . Both of these phenomena can be explained by the tendency of zeste protein, expressed in bacteria or in flies, to self-associate, forming complexes of several hundred monomers . These large aggregates bind to DNA and are found in nuclear matrix preparations, probably because they co-sediment with the matrix . The principal determinants of this self-association are located in the C-terminal half of the protein but some limited aggregation is obtained also with the N-terminal half, which contains the DNA binding domain . The z1 and zop2 mutant proteins aggregate to the same degree as the wild type but the z11G3 product, a pseudorevertant of z1, has a reduced tendency to aggregate . This mutation, which in vivo is antagonistic to z1 and does not support transvection effects, can be made to revert its phenotype when the mutant protein is over-produced under the control of the heat shock promoter . These results indicate that both the zeste-white interaction and transvection effects require the formation of high order aggregates . When the z1 protein is over-produced in vivo, it reduces the expression of an unpaired copy of white, indicating that the normal requirement for chromosome pairing is simply a device to increase the size of the aggregate bound to the white regulatory region. Hua Xi Yi Ke Da Xue Xue Bao, 1990 Sep, 21(3), 289 - 92 {Scanning electron microscope observation on proximal enamel surfaces of normal teeth}; Zhu L et al.; This observation was made on the proximal surfaces of normal permanent molars . Observations were concentrated mainly on those teeth with abraded contact areas on the mesial surface and the unabrasive distal surfaces if the partially or wholly embedded third molars . The results showed that the surfaces of the abraded contact areas were plain than those outside the contact . There were lots of pitted holes or fissures on the surfaces outside the contact areas . In the holes accumulations of bacteria could be seen . These holes and fissures could also be seen on the unexposed distal surfaces of the third molars, but no clear-defined traces of bacteria were observed in the holes. Rev Chil Pediatr, 1990 Sep-Oct, 61(5), 242 - 7 {Etiology of lower acute respiratory infections in hospitalized infants . 3 . Investigation of Chlamydia trachomatis}; Leon A et al.; Five infants with Chlamydia trachomatis associated pneumonia are analyzed . They were diagnosed out of 80 infants admitted to the hospital with pneumonia whose etiology was studied for virus, bacteria and Chlamydia trachomatis . Serum IgM antibodies to Chlamydia tr . were measured by indirect immunofluorescence (IIF), which is considered to be specific in high titers (1 greater than or equal to 32) . The five cases represented 10.4% of infants studied younger than six months . One child was born by cesarean section suggesting the possibility of other non oculogenital still undefined mechanism of transmission . Clinical symptoms and laboratory findings were characteristics of those described in Chlamydia tr . pneumonia . Chlamydia trachomatis must be considered an etiologic agent in infantile pneumonia specially in the first six months of life . The high specificity and sensitivity of the IFF makes this serologic test the best non-invasive method for diagnosis of Chlamydia tr . pneumonia currently available. Am J Dent, 1990 Sep, 3 Spec No, S53 - 6 In vitro antiplaque effects of a triclosan/copolymer mouthrinse; Williams M et al.; The influence of a mouthrinse containing 0.03% triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) and 0.25% copolymer (polyvinylmethylether maleic acid copolymer), compared to a matching placebo rinse, on in vitro plaque formation was assessed in two dynamic plaque model systems . In the controlled saliva flow cell system, the triclosan-containing rinses significantly reduced total plaque compared to the placebo rinse, with no significant differences when copolymer was removed from the active rinse formula . In the continuous culture system (chemostat flow cell model), the mean plaque was significantly reduced when compared with placebo . The results of these studies indicate that a triclosan mouthrinse, in the presence or absence of copolymer, is effective in reducing plaque in vitro. Mutat Res, 1990 Sep-Nov, 237(5-6), 259 - 69 Homologous recombination is elevated in some Werner-like syndromes but not during normal in vitro or in vivo senescence of mammalian cells; Cheng RZ et al.; Werner syndrome (WS) is a recessive genetic condition associated with markedly reduced replicative lifespans of cells in culture, high chromosomal instability in vivo and in vitro, and premature appearance of many characteristics of normal aging, including an increased incidence of cancer . We have monitored plasmid homologous recombination frequencies in diploid fibroblasts from 6 Werner or Werner-like syndrome patients, following transfection with a plasmid substrate containing 2 overlapping fragments of the TN5 Neor gene . Plasmid DNA recovered from these cells was then assayed for homologous recombination by (a) transformation of recA- bacteria to Ampr (indicating total viable plasmid) or Neor (indicating viable recombinant plasmid), and (b) by limited-cycle polymerase chain reaction (PCR) to co-amplify a recombinant fragment containing the overlap region, and a control region of the same plasmid, without bacterial transformation . Bacterial assay data indicated that recombination rates in 3 of the 6 WS strains were significantly elevated above normal controls; 4 of 6 appeared elevated by PCR assay . The highest-recombination WS strain showed evidence of reduced degradation of transfected plasmid DNA . For this small sample of WS strains, clinical severity of WS was not well correlated with recombination rate as determined by either assay (Pearson r = 0.78, not significant, for PCR assay); elevated recombination may, however, define a subset of WS at greatest risk for cancer and/or atherosclerosis . PCR assay of a hyperoxia-resistant HeLa cell line, displaying substantially increased chromosome breakage, indicated increased recombination between direct-repeat fragments . Nevertheless, elevated recombination in WS strains is unlikely to be secondary to impaired replicative capacity characteristic of WS cells, or to defective repair of chromosome damage which is increased in WS, since recombination in non-WS strains was unaffected by passage level or repeated UV irradiation. J Dermatol Sci, 1990 Sep, 1(5), 311 - 8 Flare factors and atopic dermatitis: the role of allergy; Dahl MV; Atopic dermatitis is a genetically determined eczematous skin disease strongly influenced by environmental conditions called flare factors . Allergic reactions are one such flare factor . These reactions include contact urticaria, allergic contact dermatitis, and late phase reactions . Contact urticaria could induce eczema by eliciting scratching . A late phase reaction may be involved in eczema produced by prolonged epicutaneous applications of antigens in individuals with immediate sensitivity to these antigens . Mechanisms of allergic contact dermatitis might also elicit dermatitis . Environmental allergens may include mold, dust, mite, pollens, foods, danders and bacteria. EMBO J, 1990 Sep, 9(9), 2803 - 9 Fimbrial phase variation in Bordetella pertussis: a novel mechanism for transcriptional regulation; Willems R et al.; Fimbriae belong to a class of extracellular filamentous proteins which are involved in the attachment of bacteria to host tissues . Bordetella pertussis, the etiological agent of whooping cough, produces two serologically distinct fimbriae . We show that, like a number of other B . pertussis virulence genes, transcription of the fimbrial subunit genes (fim) is positively controlled by trans-acting polypeptides encoded by the bvg locus . In addition to this coordinate control, transcription of the fim genes is regulated at an individual level by phase variation . This process is characterized by a switching between a high and low level of expression of a particular fim gene . We have identified a conserved DNA region, located close to the start of the fim genes, which is likely to be involved in both positive regulation by the bvg locus, and phase variation . This promoter region contains a stretch of approximately 15 C residues and it appears that phase transitions occur by small insertions or deletions in this C-rich region . We propose that these mutations affect transcription of the fim genes by varying the distance between the binding site for an activator and the -10 box . The fim promoter shows homology with the pertussis toxin promoter, which is also positively regulated by the bvg locus. Yale J Biol Med, 1990 Sep-Oct, 63(5), 387 - 410 G-CSF and GM-CSF in clinical trials; Antman KH; Hematopoietic growth factors have now been purified, cloned, and produced in bacteria and yeast . Those that are currently in clinical study include erythropoietin, GM-CSF, G-CSF, M-CSF (also called CSF-1), and multi-CSF (also called interleukin 3) . Growth factor appear likely to enhance the recovery and function of circulating white cells after standard-dose cancer therapy and high-bone-dose cancer therapy with marrow transplant and to restore leukocyte numbers and competence in the acquired immune deficiency syndromes and myelodysplastic syndromes . Phase I, II trials in AIDS, in cancer patients receiving chemotherapy, in cases of myeloproliferative disease, and after bone marrow transplant have been published . The results of phase III studies are just becoming available. Gene, 1990 Sep 1, 93(1), 17 - 25 Nucleotide sequence of the Caulobacter crescentus flaF and flbT genes and an analysis of codon usage in organisms with G + C-rich genomes; Schoenlein PV et al.; The Caulobacter crescentus flaFG region encodes trans-acting, regulatory factors that modulate flagellin synthesis during flagellum biogenesis . In this study, sequence analysis and experiments utilizing a promoterless cat gene demonstrated that the flaF and flbT genes have overlapping transcripts with the same orientation . In addition, the 5' ends of the flgL and flbA genes were located . A sequence resembling an Rho-factor-independent terminator was found in the 3' region of the flaF gene . This region was uniquely A + T-rich and the encoded mRNA contained an inverted repeat sequence which could form a stable stem-loop structure followed by nine U-residues . The codon usage of C . crescentus genes was examined and indicated a preference for specific codons from each of the synonymous codon groups . Furthermore, comparison to the codon usage of other organisms with G + C-rich genomes indicated a strong preference for the same codons preferred by C . crescentus. Am J Obstet Gynecol, 1990 Sep, 163(3), 887 - 9 Gram stain results from amniocentesis in patients with preterm premature rupture of membranes--comparison of maternal and fetal characteristics; Asrat T et al.; A total of 108 patients with preterm premature rupture of membranes who had undergone amniocentesis were retrospectively analyzed . Seventy-seven patients had negative amniotic fluid Gram stains and were managed expectantly . Thirty-one patients had positive amniotic fluid Gram stains confirmed by subsequent cultures and were delivered of infants on that basis . A univariate comparison of various parameters revealed significant differences in maternal temperature, pulse, and white blood cell count . Patients with positive Gram stains had lower mean gestational age, higher baseline fetal heart rate, and nonreactive fetal heart rate tracings . On the basis of a multivariate stepwise discriminate analysis, fetal heart rate greater than 150 beats/min or nonreactive nonstress test were the best predictors of the Gram stain findings, with a sensitivity of 71%, specificity of 76%, and negative predictive value of 87% . These data suggest that in patients with preterm premature rupture of membranes and fetal tachycardia or nonreactive nonstress test, amniocentesis should be performed in the initial evaluation. Proc Natl Acad Sci U S A, 1990 Sep, 87(17), 6753 - 7 Positive transcriptional feedback at the bvg locus controls expression of virulence factors in Bordetella pertussis; Scarlato V et al.; Regulation of the genes coding for virulence factors in Bordetella pertussis is controlled by the bvg locus, which encodes one putative sensory protein (BvgS) and one positive regulator of transcription (BvgA) . We have studied the transcription of the bvg locus and found that this is controlled by a 350-base-pair DNA fragment, which contains five promoters, three of which transcribe the bvg locus, one transcribes an antisense RNA, and one transcribes a virulence-associated gene . Under noninducing conditions, only the promoter P2 is active and this is responsible for the production of low amounts of regulatory proteins . Upon induction, the other four promoters become active and, by a mechanism that may involve transcriptional and translational regulation, cause a 50-fold increase of the transcriptional activator BvgA . A model of the autoregulation of the bvg locus is presented. Trends Biotechnol, 1990 Sep, 8(9), 237 - 40 Antigen delivery systems for analysing host immune responses and for vaccine development; Curtiss R 3rd; Overall, the meeting was timely and worthwhile . It is evident that there is a need for comparative studies to establish a firm foundation for future work . This is particularly important since it appears that the responses observed are influenced by the particular strain used for attenuation, the means of attenuation, the antigen-presentation system employed and the animal most immunized . In this last regard, one must recognize that most work to date has been with inbred strains of mice which differ from the genetic diversity of most hosts that are the intended beneficiaries of the immunization strategies being developed. Biochem Biophys Res Commun, 1990 Aug 31, 171(1), 273 - 9 Purification and characterization of a 7Fe-ferredoxin from Rhodobacter capsulatus; Jouanneau Y et al.; A ferredoxin was purified anaerobically from Rhodobacter capsulatus grown photoheterotrophically with excess ammonia . This ferredoxin, called ferredoxin II (FdII), had a molecular weight of approximatively 15,000 by gel filtration and 14,000 by SDS polyacrylamide gel electrophoresis indicating that it is monomeric . Its absorption spectrum (oxidized form) exhibited maxima at 280 nm and 400 nm; the A400/A280 ratio had a calculated value of 0.55 . Chemical determination of its iron and sulfur atom content, the value of the extinction coefficient at 400 nm (epsilon 400 = 26.8 mM-1 cm-1) and EPR spectra indicated that ferredoxin II contained one {3Fe-4S} and one {4Fe-4S} cluster . Upon reduction with excess dithionite only the {3Fe-4S} cluster became reduced . The reduction of both clusters was achieved by using 5-deazaflavin as photocatalyst . Ferredoxin II was also purified from bacteria grown under nitrogen limiting (nif derepressing) conditions . In in vitro assays, ferredoxin II catalyzed electron transport between illuminated chloroplasts and nitrogenase. Nature, 1990 Aug 30, 346(6287), 841 - 4 Hormonal control of Mg2+ transport in the heart; Romani A et al.; Magnesium is abundant in the mammalian body and the second most abundant cation in cells . Because the concentration of intracellular free Mg2+ is relatively high (0.2-1 mM), Mg2+ is unlikely to act as a second messenger, like Ca2+, by rapidly changing its cytosolic concentration . But changes in Mg2+ do have profound effects on cellular metabolism, structure and bioenergetics . Key enzymes or metabolic pathways, mitochondrial ion transport, Ca2+ channel activities in the plasma membrane and intracellular organelles, ATP-requiring reactions, and structural properties of cells and nucleic acids are modified by changes in Mg2+ concentration . Yet, although some information is available from giant cells and bacteria, little is known about the regulation of intracellular Mg2+ in mammalian cells . Here we report a new transport mechanism for Mg2+ across the sarcolemma of cardiac cells in both intact hearts and dissociated myocytes . We show that noradrenaline, through beta-adrenergic stimulation and increase of cyclic AMP, stimulates a large efflux of Mg2+ from cardiac cells . This transport is of major dimensions and can move up to 20% of total cellular Mg2+ within a few minutes. Ugeskr Laeger, 1990 Aug 27, 152(35), 2512 - 3 {Post-traumatic subcutaneous emphysema--misdiagnosed as gas gangrene}; Jorgensen PS et al.; Two cases of subcutaneous emphysema which developed after minor trauma are presented . One patient had a wound on the tip of the olecranon, and the other an interdigital wound . Both cases were misdiagnosed as gas gangrene, and treated with surgical revision and antibiotics . Neither necrosis nor bacteria were found . Both cases of emphysema were believed to be due to the pumping effect of the movement of the limbs. Br Dent J, 1990 Aug 11-25, 169(3-4), 83 - 6 Evaluation of a new antiseptic-containing alginate impression material; Ghani F et al.; A comparison was made of the disinfection achieved in impressions taken in Blueprint Asept alginate impression material and those taken in the plain brand of this material disinfected by immersion in 1% Hycolin solution for one minute . The plain Blueprint impression material without disinfection was used as a control . Impressions were taken of dies which had been contaminated with 0.75 ml of saliva from each of 20 volunteers . The surfaces of the impressions were used to inoculate Wilkins-Chalgren agar plates immediately and after 1 and 2 hours' storage of the impressions . The number of organisms recovered from the surface of the Blueprint Asept impressions was 1.5% of the control immediately after removal from the dies and complete disinfection was observed within one hour . In contrast, the number of organisms recovered from the surface of the impressions disinfected with 1% Hycolin solution was 30% of the control immediately after disinfection, and viable organisms could still be recovered after 2 hours' storage . Blueprint Asept impression material appears, therefore, to provide a high degree of disinfection when compared with the plain material treated with 1% Hycolin solution for one minute. Appl Environ Microbiol, 1990 Aug, 56(8), 2511 - 6 Tetrachloroethene transformation to trichloroethene and cis-1,2-dichloroethene by sulfate-reducing enrichment cultures; Bagley DM et al.; Tetrachloroethene, also known as perchloroethylene, was reductively dechlorinated to trichloroethene and cis-1,2-dichloroethene by laboratory sulfate-reducing enrichment cultures . The causative organism or group was not identified . However, tetrachloroethene was dechlorinated to trichloroethene in 50 mM bromoethane-sulfonate-inhibited enrichments and to trichloroethene and cis-1,2-dichloroethene in 3 mM fluoroacetate-inhibited enrichments . Overall transformation varied from 92% tetrachloroethene removal in 13 days to 22% removal in 65 days, depending on conditions of the inoculum, inhibitor used, and auxilliary substrate used . Neither lactate, acetate, methanol, isobutyric acid, valeric acid, isovaleric acid, hexanoic acid, succinic acid, nor hydrogen appeared directly to support tetrachloroethene dechlorination, although lactate-fed inocula demonstrated longer-term dechlorinating capability. Mol Cell Probes, 1990 Aug, 4(4), 299 - 306 DNA hybridization for diagnosis of pertussis; Reizenstein E et al.; The aim of the present study was to evaluate a mixed phase DNA hybridization assay for detection of Bordetella pertussis and Bordetella parapertussis in nasopharyngeal aspirates from patients with suspected pertussis . Among 179 consecutive patients with own or parental suspicion of pertussis, the diagnosis was confirmed in 103 patients by serology and in 52/103 (50%) cases also by culture . The remaining 76 patients served as nonpertussis controls . Direct hybridization was positive in 38% samples with serology as reference method, a non-significant difference to the 50% sensitivity for culture . Preculture of samples on membranes for 24, 48 and 72 h gave a significantly higher sensitivity only with 72 h preculture, 69% vs 50% (P = 0.007) . The 72h preculture gave, however, also a significant decrease of specificity, 87% vs 100% for routine culture (P = 0.001) and is not a more rapid diagnostic method . The result shows that rapid diagnosis by DNA hybridization can be achieved in a large proportion of pertussis cases . The presence of smaller numbers of bacteria in samples only positive after preculture indicate that DNA hybridization could be a highly sensitive diagnostic method with further development of more rapid amplification systems. Am J Dermatopathol, 1990 Aug, 12(4), 357 - 62 Spirochetal forms in the dermal lesions of morphea and lichen sclerosus et atrophicus; Ross SA et al.; Morphea and lichen sclerosus et atrophicus are cutaneous diseases that are manifest by an early edematous stage, followed later by sclerosis and atrophy . They share features with acrodermatitis chronica atrophicans and erythema chronicum migrans, diseases that have been linked to infection by the spirochete Borrelia burgdorferi . A modified silver stain was used to identify the presence of spirochetes in skin biopsy specimens of patients with morphea and lichen sclerosus et atrophicus . Spirochetal forms were identified in the lesional skin of 10 of 25 patients with morphea and in 10 of 21 cases of lichen sclerosus et atrophicus . These spiral forms of bacteria had a significant tendency to occur in early and fully developed lesions of morphea and in early lesions of lichen sclerosus et atrophicus, whereas they tended to be absent in lesions demonstrating late pathological changes. Gut, 1990 Aug, 31(8), 913 - 7 Clogging of biliary endoprostheses: a new perspective; Coene PP et al.; Endoscopic palliation with biliary endoprostheses is now an established treatment for benign and malignant strictures of the biliary tree . These endoprostheses, however, tend to clog with time . We investigated this problem by undertaking in vitro studies on stents of different designs made of different polymer materials . The stent that performed best was then tested in an in vivo trial . There was a direct relation in vitro between the frictional coefficient of a polymer and the amount of encrusted material . Catheters perfused in bacterially contaminated bile, irrespective of material and design, accrued significantly more sludge than catheters perfused with sterilised bile . The presence of side holes significantly increased the amount of sludge in the stents, but eliminated any differences between the various materials . We therefore investigated the effect of omitting side holes in a clinical trial which consisted of two groups of 20 patients each . The group treated with conventional stents accrued significantly more sludge in the stents than the group treated with experimental stents without side holes (p less than 0.05) . The absence of side holes did not cause incomplete drainage or increase morbidity . Side holes are detrimental to stent patency, which is adversely affected by other factors including bacteria and proteins. J Pharmacol Exp Ther, 1990 Aug, 254(2), 612 - 5 The anaerobic metabolism of verapamil in rat cecal contents forms nor-verapamil and thiocyanate; Koch RL et al.; The anaerobic metabolism of verapamil was studied to determine the role the intestinal flora may have on the disposition of verapamil . Metabolites produced by the flora could be the source of adverse reactions reported only with the p.o . controlled release formulations but not with immediate release formulations . Verapamil was found to be metabolized to thiocyanate, nor-verapamil and several more polar metabolites that were detected by either a specific assay for cyanide and thiocyanate or a high-performance liquid chromatography (HPLC) assay, respectively . The rate of thiocyanate formation with an initial substrate concentration of 2 mM verapamil was found to be 0.008 +/- 0.004 microgram/hr/ml of 1:10 cecal suspension . The N-demethylated metabolite, nor-verapamil, was detected in the cecal suspensions but it also disappeared with time . The rate of verapamil disappearance was dependent on the concentration of bacteria in the incubation mixture; the rate being most rapid with the highest concentration of bacteria . Acetonitrile and butyronitrile were also found to be metabolized by the cecal flora . Cyanide as well as thiocyanate were produced from both organo-nitriles . These results suggest that the cyano group of verapamil, acetonitrile and butyronitrile were all cleaved to form cyanide and/or thiocyanate . With verapamil, cleavage of the cyano group would form new chemical entities that could be pharmacologically active and serve as a source of some of the adverse reactions or side-effects reported. Clin Orthop, 1990 Aug, (257), 226 - 30 Synovial leukocytosis in infectious arthritis; McCutchan HJ et al.; The clinical presentation of 41 adult patients with infectious arthritis has been reviewed with special emphasis on initial synovial fluid leukocytosis . Fifty percent of the patients with culture-proven joint-space infections had synovial fluid leukocyte counts below 28,000/mm3 . Comparison of this investigation with previous studies of similar magnitude demonstrates a striking difference in the mean and median synovial fluid white cell counts . The population reviewed had a higher incidence of patients with potentially immunocompromising medical conditions than previous reports . Similarities between this and previous reports include predisposing conditions, the spectrum of pathogens cultured, associated clinical findings on admission, hospital course, and mortality . The data presented here document the magnitude of potential overlap between the synovial fluid leukocytosis in infected joints and in joints afflicted with other forms of inflammatory arthropathy . Three patients populations (malignant neoplasms, steroid use, and intravenous drug abuse) with positive cultures from synovial fluid aspirates but initial synovial fluid white cell counts averaging below 50,000 cells/mm3 were identified . Patients with moderate synovial fluid leukocytosis, especially those potentially immunocompromised, must be considered to have infectious arthritis unless other causes of inflammatory arthropathies are demonstrated. J Neuroimmunol, 1990 Aug, 28(3), 201 - 8 Muramyl-dipeptide, a macrophage-derived cytokine, alters neuronal activity in hypothalamus and hippocampus but not in the dorsal raphe/periaqueductal gray of rats; Dougherty PM et al.; Muramyl-dipeptide (MDP) is derived in vivo by degradation of bacteria cell walls and is the minimum fragment that stimulates the acute phase response to bacterial infection . The present study investigates whether this specific product of an immune response affects central nervous system (CNS) function . To this end, the activity of single neurons within the hypothalamus, hippocampus, and dorsal raphe/periaqueductal gray region prior to and following systemic (i.p.) injection was studied . The results obtained from a total of 120 cells demonstrate that single hypothalamic and hippocampal neurons, sites previously shown to aid in the integration of various environmental stimuli into physiologic processes, alter their neuronal activity in site-specific manners following MDP administration . The specificity of the responses included both the threshold for activation of particular sites, effects of increasing dosages upon response pattern characteristics, and time course to the changes observed . These results therefore suggest that MDPs may play a role in the neuro-immunologic regulatory pathways during the immune response to bacterial infection. Infect Immun, 1990 Aug, 58(8), 2516 - 22 A new assay for invasion of HeLa 229 cells by Bordetella pertussis: effects of inhibitors, phenotypic modulation, and genetic alterations; Lee CK et al.; Invasion and intracellular survival of Bordetella pertussis in HeLa 229 cells was studied by a new assay that utilizes polymyxin B instead of gentamicin to rapidly kill extracellular organisms . Invasion measured by this assay was time and temperature dependent and was inhibited by the microfilament drug cytochalasin D . The invasion process was also dependent on a functional vir locus (also known as bvg), the positive regulator of virulence gene expression in B . pertussis . Four spontaneous Vir- phase variants of B . pertussis and a mutant with a transposon insertion mutation in the vir locus did not invade . Cells that were environmentally modulated and thus did not express virulence determinants also did not invade . Two Vir- mutants, a vir-directed plasmid insertion mutant and a UV-light-induced mutant, were capable of invasion, although they did not produce other known virulence factors such as pertussis toxin and hemolysin but did produce small amounts of filamentous hemagglutinin (FHA) and the 69-kilodalton outer membrane protein . None of 70 Tn5 IS50L::phoA (TnphoA) insertion mutants of strain Bp18323 (including three mutants defective in FHA) tested showed any reproducible defect in invasion . A mutant carrying a site-directed deletion mutation in FHA was also capable of invasion in our assay . These data suggest that there is redundancy in the invasion functions of B . pertussis and that one or more of these are coordinately regulated with FHA and the 69-kilodalton outer membrane protein more tightly than with other vir-activated gene products. Gastroenterology, 1990 Aug, 99(2), 352 - 61 Helicobacter mustelae-associated gastritis in ferrets . An animal model of Helicobacter pylori gastritis in humans; Fox JG et al.; Gastric Helicobacter mustelae was present in 100% of 11 adult female ferrets (Mustela putorius furo) . The high immunoglobulin G antibody levels to H . mustelae in all ferrets showed a significant immune response to the organism . Urease mapping of the ferret stomach indicated that the bacteria heavily colonized the proximal duodenum and antrum and, to a lesser extent, the corpus . The histological gastritis observed coincided with presence of H . mustelae . Superficial gastritis was noted in the oxyntic gastric mucosa, whereas in the distal antrum the chronic inflammatory response occupied the full thickness of the mucosa . In the proximal antrum and transitional mucosa, focal glandular atrophy and regeneration were observed . Seven control specific-pathogen-free ferrets were not colonized with the bacteria, did not have detectable levels of immunoglobulin G H . mustelae antibody, and did not have H . mustelae-associated gastritis . The ferret lacks the polymorphonuclear-cell response seen in active chronic gastritis typically described with Helicobacter pylori gastritis in humans . However, the lesion in ferrets does closely resemble the diffuse antral gastritis seen in a subset of adults with H . pylori gastritis as well as children infected with H . pylori . Like H . pylori, H . mustelae adheres tightly to gastric mucosa . The ferret infected with H . mustelae, in addition to specific-pathogen-free uninfected control ferrets, will make longitudinal studies possible, enabling dissection of multiple host and environmental variables that influence the effect of H . mustelae colonization on progression and severity of gastroduodenal disease. Immunol Lett, 1990 Aug, 25(1-3), 43 - 7 T cell responses in a sporozoite-immunized human volunteer and a chimpanzee; Nardin EH; We have recently investigated the specificity of T cells induced in a human volunteer and a chimpanzee immunized by multiple exposures to the bites of large numbers of malaria-infected mosquitoes . T cell lines and clones have been obtained from a human volunteer immunized with Plasmodium falciparum sporozoites . These CD4+ T cell clones specifically recognize the native circumsporozoite (CS) protein expressed on sporozoites, as well as bacteria- and yeast-derived recombinant falciparum CS proteins . The epitope recognized by the sporozoite specific human T cells mapped to the 5' repeat region of the CS protein and was contained in the NANPNVDPNANP sequence . A T cell line has also been isolated from PBL obtained from a chimpanzee immunized by multiple exposures to the bits of P . vivax infected mosquitoes . The CS-specific chimpanzee T cells were used to identify a T cell epitope within a repeat region of the P . vivax CS protein. Environ Health Perspect, 1990 Aug, 88, 13 - 25 Cellular responses to oxidative stress: the {Ah} gene battery as a paradigm; Nebert DW et al.; A major source of oxidative stress in animals is plant stress metabolites, also termed phytoalexins . The aromatic hydrocarbon-responsive {Ah} gene battery is considered here as a model system in which we can study metabolically coordinated enzymes that respond to phytoalexin-induced oxidative stress . In the mouse, the {Ah} battery comprises at least six genes: two Phase I genes, CYP1A1 and CYP1A2; and four Phase II genes, Nmo-1, Aldh-1, Ugt-1, and Gt-1 . All six genes appear to be regulated positively by inducers such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other ligands of the Ah receptor . In the absence of foreign inducer, the control of Nmo-1 gene expression is independent of the control of CYP1A1 and CYP1A2 gene expression . The radiation deletion homozygote c14CoS/c14CoS mouse is lacking about 1.1 centiMorgans of chromosome 7 . Although having no detectable CYP1A1 or CYP1A2 activation, the untreated c14CoS/c14CoS mouse exhibits markedly elevated transcripts of the Nmo-1 gene and three growth arrest- and DNA damage-inducible (gadd) genes . These data suggest that the missing region on chromosome 7 in the c14CoS/c14CoS mouse contains a gene(s), which we propose to call Nmo-1n, encoding a trans-acting factor(s) that is a negative effector of the Nmo-1 and gadd genes . The three other {Ah} battery Phase II genes behave similarly to Nmo-1 in the c14CoS/c14CoS mouse . This coordinated response to oxidative stress and DNA damage, by way of the release of a mammalian battery of genes from negative control, bears an interesting resemblance to the SOS response in bacteria. Dtsch Zahnarztl Z, 1990 Aug, 45(8), 485 - 9 {In-vivo corrosion tests of dental alloys in relationship to saliva pH}; Simonis A et al.; The corrosion of four dental alloys and titanium was studied in relationship to saliva pH and plaque accumulation in vivo . Test specimens were scanned for porosities with an image analysis system before and after exposure to the oral milieu . The saliva pH was monitored during the study period . After four days of exposure in the mouth the plaque accumulation and the vitality of the plaque on the alloy surfaces was evaluated . Plaque accumulation and mean saliva-pH were not correlated with the observed surface corrosion . The least surface effects were observed on titanium, which showed the highest plaque accumulation . Different alloys showed different bacteriostatic effects . The least amount of living bacteria was found on titanium . Plaque accumulation and bacteria vitality depended on material and test person. J Gen Microbiol, 1990 Aug, 136 ( Pt 8), 1623 - 9 Extensive heterogeneity of the protein composition of Chlamydia trachomatis following serial passage in two different cell lines; Goswami PC et al.; To determine if the host-modulated adherence characteristics of the intracellular bacterial pathogen Chlamydia trachomatis were due to the acquisition of altered surface-exposed proteins, highly purified chlamydiae grown in two different host cells were analysed . Two serovars, L1 and E, were grown for multiple passages in both HeLa and McCoy host cells . Numerous protein differences in the chlamydial elementary bodies (EB) of each serovar grown in the two different hosts were detected by two-dimensional (2-D) gel electrophoresis and fluorography of radioactively labelled proteins . At least four to six serial passages in the alternative host were necessary before the changes were apparent . Iodination of suspensions of purified chlamydiae and 2-D electrophoresis revealed several surface proteins that were determined by the host cells in which the bacteria had replicated . These iodinated chlamydial proteins were removed by treatment of the iodinated EB with trypsin, indicating their location at the bacterial surface . Two of the major constituents of the outer-membrane complex, the cysteine- and methionine-rich 60 kDa and 40 kDa proteins, remained unchanged in both molecular mass and charge during the host adaptation . Several chlamydial proteins capable of binding iodinated host membrane preparations also exhibited host-dependent alterations . Immunoblotting experiments with a rabbit and a human polyclonal sera indicated that distinct host-specified chlamydial proteins were reactive with the two sera. Mol Gen Genet, 1990 Aug, 223(1), 40 - 8 Genetic analysis of the LexA repressor: isolation and characterization of LexA(Def) mutant proteins; Oertel-Buchheit P et al.; We report the isolation of LexA mutant proteins with impaired repressor function . These mutant proteins were obtained by transforming a LexA-deficient recA-lacZ indicator strain with a randomly mutagenized plasmid harbouring the lexA gene and subsequent selection on MacConkey-lactose indicator plates . A total of 24 different lexA(Def) missense mutations were identified . All except three mutant proteins are produced in near-normal amounts suggesting that they are fairly resistant to intracellular proteases . All lexA(Def) missense mutations are situated within the first 67 amino acids of the amino-terminal DNA binding domain . The properties of an intragenic deletion mutant suggest that the part of the amino-terminal domain important for DNA recognition or domain folding should extent at least to amino acids 69 or 70 . A recent 2D-NMR study (Lamerichs et al . 1989) has identified three alpha helices in the DNA binding domain of LexA . The relative orientation of two of them (helices 2 and 3) is reminiscent of, but not identical to, the canonical helix-turn-helix motif suggesting nevertheless that helix 3 might be involved in DNA recognition . The distribution of the lexA(Def) missense mutations along the first 67 amino-terminal amino acids indeed shows some clustering within helix 3, since 8 out of the 24 different missense mutations are found in this helix . However one mutation in front of helix 1 and five mutations between amino acids 61 and 67 suggest that elements other than helices 2 and 3 may be important for DNA binding. J Environ Sci Health B, 1990 Aug, 25(4), 433 - 46 Enhanced degradation of carbofuran in Pacific Northwest soils; Getzin LW et al.; Persistence of 14C-carbonyl carbofuran was measured in Pacific Northwest soils that had received 1-14 applications of the insecticide for root weevil control on perennial crops . Insecticide decay curves were obtained in nonautoclaved soil and several autoclaved soil samples from previously-treated fields and in nonautoclaved soils from paired control sites not previously treated with carbofuran . The insecticide usually degraded faster in soil from previously-treated fields than in soil from corresponding control fields . Among 26 previously-treated fields, the pseudo half-life (time for 50% loss) of carbofuran was less than one wk in 11 soils, 1-3 wks in 8 soils and greater than 4 wks in the remaining soils . Among the nontreated control fields the pseudo half-life was greater than 2 wks in all cases and greater than 15 wks in 5 of the soils . The carbofuran decay curve always possessed an initial lag phase where soil mixing enhanced insecticide decline . Carbofuran degraded very slowly in autoclaved soil samples . The half-life of carbofuran exceeded 16 wk in all autoclaved soils tested and in most instances 85-90% of the original dosage remained when the tests were terminated 112 days after treatment . These results provided evidence that many of the soils which received applications of carbofuran over the past several years have developed a capacity to degrade carbofuran very rapidly. J Dairy Sci, 1990 Aug, 73(8), 2112 - 20 Lymphocyte blastogenesis inhibition by milk whey as an indicator of mastitis; Barta O et al.; Sixty milk whey samples prepared from quarters of five cows with a history of mastitis were tested for their ability to inhibit DNA synthesis in mitogen-stimulated lymphocytes . The inhibitory activity was compared with milk SCC, electrical conductivity, pH, and the number of colony-forming bacteria in the milk . Milk whey contained factors that inhibited DNA synthesis in cultured lymphocytes . Inhibition of mitogen-induced DNA synthesis increased with the clinical severity of mastitis and with increased values of indirect indicators of mastitis . The increases in inhibition and electrical conductivity were delayed past the increases in SCC . Milk whey (10 microliters) from quarters with clinical mastitis and from quarters with SCC greater than 900,000 inhibited 96 to 100%, 84 to 100%, and 69 to 100% of DNA synthesis in 3-d cultures of lymphocytes stimulated with Concanavalin A, phytohemagglutinin P, and pokeweed mitogen, respectively . The numbers of colony-forming bacteria correlated least with the inhibitory activity. Int J Food Microbiol, 1990 Aug, 11(1), 93 - 102 Standard plate counts of drinking water: a comparison between incubation temperatures of 20 and 30 degrees C; Spinedi C et al.; Standard plate counts of 5085 drinking water samples gathered in the Region of Basle were carried out over a period of 9 years (1977 to 1985) . Two conditions of incubation were evaluated: 20 degrees C and 30 degrees C for 72 h . In ground water samples (3048 samples) colony forming units (cfu) at 30 degrees C were found to be higher than counts at 20 degrees C incubation, 45% of the samples contained greater than or equal to 2 cfu/ml at 30 degrees versus 35% at 20 degrees C . The median was 1 cfu/ml at both temperatures . In spring water samples (2036 samples) bacterial counts at 20 degrees C were found to be higher than counts at 30 degrees C incubation, 61% of the samples contained greater than 10 cfu/ml at 20 degrees C versus 51% at 30 degrees C . The median was 19 cfu/ml at 20 degrees C incubation versus 11 cfu/ml at 30 degrees C . These differences were statistically significant with p less than 0.001 (Wilcoxon matched-pairs signed-rank test) . No correlation was found between bacterial counts at 20 degrees C and bacterial counts at 30 degrees C, nor between bacterial counts and original water temperatures . It appears that incubation temperatures of 20 degrees C and 30 degrees C favor the growth of different populations of bacteria and temperature is not the only factor . However, from a practical point of view the use of only one incubation temperature seems to be justified for the purpose of judging the sanitary quality of drinking water. J Clin Periodontol, 1990 Aug, 17(7 Pt 1), 454 - 62 Intracrevicular application of tetracycline in white petrolatum for the treatment of periodontal disease; Eckles TA et al.; In vitro tests in our laboratory have shown that 40% tetracycline HCl in a white petrolatum carrier (TTC-WP) has potential as a sustained release, autodissipating system . The present study tested subgingival placement of TTC-WP via syringe in vivo . Quadrants (2 diseased sites in each) in 9 patients with moderate/severe periodontitis were randomly assigned to receive the following treatments: (1) TTC-WP; (2) WP only; (3) scaling and root planing; (4) untreated control . TTC release into gingival crevicular fluid (GCF) over time (baseline, 1, 8, 24, 72 and 168 h) was measured using an agar diffusion bioassay . Clinical parameters and subgingival bacterial morphotypes (darkfield analysis) were also evaluated over time (baseline, 2, 4, 8, 12 weeks) . Results indicated that TTC-WP was easily placed into periodontal pockets and biologically effective TTC was released into GCF for at least 3 days (mean concentration = 115.8 +/- 43.1 micrograms/ml at 3 days) . TTC-WP reduced probing pocket depths and bleeding on probing relative to baseline measurements for 8-12 weeks post-treatment, and reduced %s of motile rods and spirochetes, with an accompanying increase in cocci, for 2-8 weeks . Similar effects were noted in the scaled and root-planed sites, but for a longer duration . TTC-WP and WP were clinically dissipated after 2 weeks and no adverse tissue reactions were observed . From these findings, subgingival TTC-WP cannot replace scaling and root planing therapy, but has characteristics useful in subgingival plaque control. Antimicrob Agents Chemother, 1990 Aug, 34(8), 1508 - 11 Activities of clarithromycin, sulfisoxazole, and rifabutin against Mycobacterium avium complex multiplication within human macrophages; Perronne C et al.; The activities of clarithromycin, sulfisoxazole, and rifabutin against three virulent strains of Mycobacterium avium complex isolated from patients with acquired immunodeficiency syndrome were evaluated in a model of intracellular infection . Human monocyte-derived macrophages were infected at day 6 of culture with M . avium complex . Intracellular bacteria were counted 60 min after inoculation . Extra- and intracellular bacteria were counted at days 4 and 7 after inoculation . The concentrations used were 4 micrograms of clarithromycin per ml (MICs for the three strains, 4, 4, and 4 micrograms/ml), 50 micrograms of sulfisoxazole per ml (MICs, 50, 25, and 25 micrograms/ml), and 0.5 micrograms of rifabutin per ml (MICs, 2, 0.5, and 0.5 micrograms/ml) . Compared with controls, clarithromycin and rifabutin slowed the intracellular replication of the three strains (at day 7 after inoculation, P was less than 0.01 for the first strain and less than 0.001 for the two others) . Sulfisoxazole was ineffective against the three strains . Clarithromycin was as effective as rifabutin . Clarithromycin plus rifabutin was as effective as each single agent . Clarithromycin plus sulfisoxazole was as effective as clarithromycin alone. Br J Surg, 1990 Aug, 77(8), 878 - 81 Mutagenicity of bile and duodenal adenomas in familial adenomatous polyposis; Spigelman AD et al.; Duodenal adenomas occur almost inevitably in patients with familial adenomatous polyposis (FAP) whereas gastric adenomas are rare . FAP patients are also at high risk of duodenal cancer . Within the duodenum, adenomas cluster around the ampulla of Vater, as do the majority of duodenal cancers, suggesting that bile plays a role in tumour development . We therefore tested duodenal bile from 29 postcolectomy FAP patients (27 of whom had duodenal adenomas) and 24 non-FAP patients for mutagenicity, using techniques that detect point mutations in bacteria . Results which appeared to show that FAP bile was more mutagenic than control bile could be accounted for by a feeding effect, elimination of which also eliminated 'mutagenicity' . Under the conditions of our assays we conclude that if bile is an important factor in genesis of duodenal tumours, it does not act by inducing point mutation. Pract Odontol, 1990 Aug, 11(8), 49 - 53 {Correlation of clinico-radiographic findings with histopathology in teeth diagnosed as necrotic}; Garces Ortiz M et al.; A correlation between clinical and X-ray findings with histopathology in teeth diagnosed as necrotic 30 permanent human teeth with a deep carious lesion associated with a periapical radiolucency were studied . Results were based on the histopathologic findings, correlated with clinical and radiographic data, analyzed underlight microscope . The clinically diagnosed necrotic teeth with a periapical radiolucency were 19 (63.33%), showed remnants of vital pulp tissue under histologic observation, mainly in the medium and apical root thirds, in multi-rooted teeth . Presence of infiltrated bacteria was also observed at dentinal tubules coronally . 11 teeth (36.66%) remnants did not show any evidence of vital pulp tissue, only total necrosis was observed . This group showed the presence of bacteria infiltrated at the dentinal tubules coronally and into the root canals. Epidemiol Infect, 1990 Aug, 105(1), 79 - 85 Serological grouping of Treponema hyodysenteriae; Hampson DJ et al.; Two Australian isolates of Treponema hyodysenteriae which did not fit within the current serological grouping system for these bacteria were examined by agarose gel double immunodiffusion tests (AGDP) . Isolate Vic1 was serologically unique, and we propose that it becomes the type organism for a new sixth serological group of T . hyodysenteriae (Group F) . Isolate Q1 was unusual in that lipopolysaccharide (LPS) extracted from it reacted strongly in AGDP with serum raised against the type organism for serogroup D (A1), and also weakly with serum raised against the type organism for serogroup B (WA1) . The nature of this cross-reactivity was examined by using cross-absorbed antisera in AGDP, and by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis . The pattern of serological cross-reactivity between Q1, A1 and WA1 was complex and was not fully defined, but the isolate Q1 apparently shared low molecular weight 'serogroup' LPS antigens with A1, and shared higher molecular weight LPS antigens with WA1 . On this basis Q1 was designated as belonging to serogroup D, although it was recommended that this be qualified as D (B) to indicate the presence of weak cross-reactivity with serogroup B . Such serological cross-reactivity may have significance in relation to the development of immunity to T.hyodysenteriae . Isolate Q1 may be a potentially useful organism for vaccine development because of its ability to induce a good serological response to LPS of treponemes from both serogroups D and B. Proc Natl Acad Sci U S A, 1990 Aug, 87(15), 5851 - 5 In vitro transcription of two rRNA genes of the archaebacterium Sulfolobus sp . B12 indicates a factor requirement for specific initiation; Hudepohl U et al.; We describe a cell-free transcription system for the archaebacterium Sulfolobus sp . B12 that specifically initiates transcription at the 5S rRNA-encoding DNA and the 16S/23S rRNA-encoding DNA promoters of the same species . With this crude extract system, specific initiation was absolutely dependent on the box A motif, a highly conserved promoter element in archaebacteria located approximately 25 base pairs upstream of transcription initiation sites . In vitro transcription of the rRNA genes by purified RNA polymerase, however, resulted in semi-specific, box A-independent initiation, indicating that factor(s) in the crude extract were necessary for the highly specific box A-dependent transcription . Fractionation of the cell-free extract by sucrose-gradient centrifugation resulted in the identification of a low molecular weight fraction complementing purified RNA polymerase to an extract-like specificity. J Bacteriol, 1990 Aug, 172(8), 4715 - 8 Conservation of hydrogenase and polyferredoxin structures in the hyperthermophilic archaebacterium Methanothermus fervidus; Steigerwald VJ et al.; A 3.3-kilobase-pair region of the Methanothermus fervidus genome encoding part of the small subunit and all of the large subunit of the methyl viologen-reducing hydrogenase and a polyferredoxin was cloned and sequenced . The sequence of this hyperthermophilic hydrogenase conforms to the consensus sequence established for procaryotic {NiFe} hydrogenases . Although the M . fervidus polyferredoxin is the same size as the Methanobacterium thermoautotrophicum ferredoxin, containing six tandemly arranged bacterial ferredoxinlike domains, these two proteins are predicted to be only 64% identical in their primary sequences. J Clin Microbiol, 1990 Aug, 28(8), 1770 - 3 Confirmatory assay increases specificity of the chlamydiazyme test for Chlamydia trachomatis infection of the cervix; Moncada J et al.; Enzyme immunoassays for the detection of chlamydial antigens are commonly used to diagnose Chlamydia trachomatis infection . As is true for all nonculture methods, the specificities of these tests are a concern . A confirmatory blocking assay (Abbott Laboratories, North Chicago, Ill.) was evaluated at four sexually transmitted disease test sites . This assay is designed to confirm true-positive Chlamydiazyme (CZ) specimens and to identify false-positive CZ reactions caused by cross-reacting bacteria . Cervical specimens were collected from 2,891 women . Chlamydia prevalence by tissue culture (TC) was 9.2% (266 of 2,891 specimens) . Compared with TC, the sensitivity and specificity of CZ were 78.9% (210 of 266 specimens) and 98.2% (2,577 of 2,625 specimens), respectively . There were 48 CZ false-positive reactions . The direct fluorescent-antibody test (DFA) was positive for 31 of 48 false-positive reactions, indicating culture misses . Thus, when the standard was both TC and DFA, CZ sensitivity was 81.1% and CZ specificity was 99.3% . Of the 17 CZ-positive patients who were negative by both TC and DFA, 3 were negative on repeat CZ and 11 of 14 were identified as false positive by the confirmatory assay . The confirmatory test was positive for CZ-positive women who were positive by TC or DFA . Use of the confirmatory test, which increased the specificity to 99.9%, would increase confidence in positive CZ results and make the test more useful for screening populations with a low prevalence of C . trachomatis infection. FEBS Lett, 1990 Aug 1, 268(2), 427 - 30 Regulation of plant gene expression by antisense RNA; Mol JN et al.; Regulation of gene expression by antisense RNA was first discovered as a naturally-occurring phenomenon in bacteria . Recently natural antisense RNAs have been found in a variety of eukaryotic organisms; their in vivo function is, however, obscure . Deliberate expression of antisense RNA in animal and plant systems has lead to successful down-regulation of specific genes . We will review the current status of antisense gene action in plant systems . The recent discovery that 'sense' genes are able to mimic the action of antisense genes indicates that (anti)sense genes must operate by mechanisms other than RNA-RNA interaction. Eur J Biochem, 1990 Jul 31, 191(2), 297 - 305 Cytochrome aa3 from Sulfolobus acidocaldarius . A single-subunit, quinol-oxidizing archaebacterial terminal oxidase; Anemuller S et al.; The thermoacidophilic archaebacterium Sulfolobus acidocaldarius (DSM 369) extrudes protons when expending respiratory energy {Moll, R . & Schafer, G . (1988) FEBS Lett . 232, 359-363} . Cytochromes of the membrane electron-transport systems are assumed to represent the proton pumps . Only a- and b-type cytochromes can be found; no c-type cytochromes are present . Of the two terminal oxidases {Anemuller, S . & Schafer, G . (1989) FEBS Lett . 244, 451-455} one shows an absorption band at 604-605 nm, typical of cytochromes of the aa3 type . This hemoprotein has been solubilized from the membrane and purified to homogeneity . It exhibits distinct differences from known aa3-type oxidases . (a) It consists of a single polypeptide subunit of 38-40 kDa apparent molecular mass with two heme-a molecules and two copper ions . (b) In the oxidized state, absorption maxima are found at 421 nm and 597 nm, and in the reduced state at 439 nm and 601 nm; CO difference spectra suggest one heme to be a heme-a3 centre . (c) The redox potentials of the heme centres are +220 mV and +370 mV, respectively . (d) A high-spin heme signal at g = 6 is present in EPR spectra, which is more prominent than the low-spin heme signal at g = 3, the former already being present in the oxidized state . A signal at g = 2.1 may be due to one of the copper ions and is superimposed upon a minor free radical signal at g = 2 . (e) Caldariella quinone was also isolated from the plasma membrane of Sulfolobus . Its redox midpoint potential at pH 6.5 was determined to be +100 (+/- 5) mV; spectral properties have also been determined . (f) The isolated aa3 preparation does not oxidize cytochrome c; however, it oxidizes N,N,N',N'-tetramethyl-1,4-phenylenediamine dihydrochloride as an artificial single-electron donor as well as reduced caldariella quinone, which is assumed to represent the natural substrate . The reaction is cyanide-sensitive and the product of oxygen reduction is water . (g) On the basis of the results obtained a novel type of cytochrome aa3 is postulated in this paper which oxidizes reduced quinones; its ability to act as a proton pump remains to be shown. J Mol Biol, 1990 Jul 20, 214(2), 497 - 525 Refined structure of dienelactone hydrolase at 1.8 A; Pathak D et al.; The structure of dienelactone hydrolase (DLH) from Pseudomonus sp . B13, after stereochemically restrained least-squares refinement at 1.8 A resolution, is described . The final molecular model of DLH has a conventional R value of 0.150 and includes all but the carboxyl-terminal three residues that are crystallographically disordered . The positions of 279 water molecules are included in the final model . The root-mean-square deviation from ideal bond distances for the model is 0.014 A and the error in atomic co-ordinates is estimated to be 0.15 A . DLH is a monomeric enzyme containing 236 amino acid residues and is a member of the beta-ketoadipate pathway found in bacteria and fungi . DLH is an alpha/beta protein containing seven helices and eight strands of beta-pleated sheet . A single 4-turn 3(10)-helix is seen . The active-site Cys123 residues at the N-terminal end of an alpha-helix that is peculiar in its consisting entirely of hydrophobic residues (except for a C-terminal lysine) . The beta-sheet is composed of parallel strands except for strand 2, which gives rise to a short antiparallel region at the N-terminal end of the central beta-sheet . The active-site cysteine residue is part of a triad of residues consisting of Cys123, His202 and Asp171, and is reminiscent of the serine/cysteine proteases . As in papain and actinidin, the active thiol is partially oxidized during X-ray data collection . The positions of both the reduced and the oxidized sulphur are described . The active site geometry suggests that a change in the conformation of the native thiol occurs upon diffusion of substrate into the active site cleft of DLH . This enables nucleophilic attack by the gamma-sulphur to occur on the cyclic ester substrate through a ring-opening reaction. Nature, 1990 Jul 19, 346(6281), 287 - 91 cis-trans recognition and subunit-specific degradation of short-lived proteins; Johnson ES et al.; The N-end rule, a code that relates the metabolic stability of a protein to the identity of its amino-terminal residue, is universal in that different versions of the N-end rule operate in mammals, yeast and bacteria (unpublished data) . The N-end rule-based degradation signal comprises a destabilizing amino-terminal residue and a specific internal lysine residue . We now show that, in a multisubunit protein, these two determinants can be located on different subunits and still target the protein for destruction . Moreover, in this case (trans recognition) only the subunit that bears the lysine determinant is actually degraded . Thus an oligomeric protein can contain both short-lived and long-lived subunits . These insights have functional and practical implications. FEBS Lett, 1990 Jul 16, 267(2), 199 - 202 Selective solubilization of chlorosome proteins in Chloroflexus aurantiacus; Eckhardt A et al.; Proteins were solubilized selectively from chlorosomes of Chloroflexus aurantiacus by electrophoretic gel filtration according to Griebenow et al . Whereas the 11 kDa and 18 kDa proteins were extracted almost completely, the remaining modified chlorosomes contained high amounts of pigment and c-protein . It was concluded that the c-protein in contradiction to the publication by Griebenow et al . is indeed localized in the interior of Chloroflexus chlorosomes. Pol Tyg Lek, 1990 Jul 16-30, 45(29-31), 625 - 7 {A few years of following up results of chronic respiratory infections with broncho-vaxom}; Polubiec A; Broncho-Vaxom was administered to 57 patients with chronic respiratory infections . A significant improvement was noted in 70% of the treated patients whereas mild improvement in 21% . Discussing the results of Broncho-Vaxom therapy, the author suggests so-called maintenance therapy with the same preparation to stabilize its effect. Pol Tyg Lek, 1990 Jul 16-30, 45(29-31), 601 - 4 {T and B lymphocytes and serum alpha 1-antitrypsin activity in children with bronchial asthma treated with broncho-vaxom}; Wartenberg J et al.; The aim of this study was to evaluate an effect of Broncho-Vaxom treatment on T and B lymphocytes and serum alpha 1AT in children treated at "Zuch" sanatorium in Szczawno-spa . The trial involved 46 school aged children suffering from infectious or infectious-atopic asthma . The post-Broncho-Vaxom treatment values for T lymphocytes were significantly higher in infectious, and significantly lower for B lymphocytes in infectious-atopic asthma . Serum alpha 1AT activity in children suffering from infectious asthma decreased significantly after the treatment . A correlation between the efficacy of the treatment and the lymphocyte percentage was observed . In children with very effective clinical results of Broncho-Vaxom treatment, the significant increase in T lymphocyte, and decrease in B lymphocyte populations was observed . Changes in T and B lymphocyte percentage were analysed in respect to alpha 1AT pre-treatment activity . In children with high alpha 1AT value, T lymphocytes after the treatment increased significantly in infectious, and B lymphocytes decreased significantly in infectious-atopic group. J Biol Chem, 1990 Jul 5, 265(19), 11251 - 8 Characterization of the binding of Actinomyces naeslundii (ATCC 12104) and Actinomyces viscosus (ATCC 19246) to glycosphingolipids, using a solid-phase overlay approach; Stromberg N et al.; Actinomyces naeslundii (ATCC 12104) and Actinomyces viscosus (ATCC 19246) were radiolabeled externally (125I) or metabolically (35S) and analyzed for their ability to bind glycosphingolipids separated on thin layer chromatograms or coated in microtiter wells . Two binding properties were found and characterized in detail . (i) Both bacteria showed binding to lactosylceramide (LacCer) in a fashion similar to bacteria characterized earlier . The activity of free LacCer was dependent on the ceramide structure; species with 2-hydroxy fatty acid and/or a trihydroxy base were positive, while species with nonhydroxy fatty acid and a dihydroxy base were negative binders . Several glycolipids with internal lactose were active but only gangliotriaosylceramide and gangliotetraosylceramide were as active as free LacCer . The binding to these three species was half-maximal at about 200 ng of glycolipid and was not blocked by preincubation of bacteria with free lactose or lactose-bovine serum albumin . (ii) A . naeslundii, unlike A . viscosus, showed a superimposed binding concluded to be to terminal or internal GalNAc beta and equivalent to a lactose-inhibitable specificity previously analyzed by other workers . Terminal Gal beta was not recognized in several glycolipids, although free Gal and lactose were active as soluble inhibitors . The binding was half-maximal at about 10 ng of glycolipid . A glycolipid mixture prepared from a scraping of human buccal epithelium contained an active glycolipid with sites for both binding specificities. Gene, 1990 Jul 2, 91(1), 27 - 34 The methane monooxygenase gene cluster of Methylococcus capsulatus (Bath); Stainthorpe AC et al.; Methane is oxidised to methanol in methanotrophic bacteria by the enzyme methane monooxygenase (MMO) . Methylococcus capsulatus (Bath) produces a soluble MMO which oxidises a range of aliphatic and aromatic compounds with potential for commercial exploitation . This multicomponent enzyme has been extensively characterised and biochemical data have been used to identify a 12-kb fragment of Methylococcus DNA carrying the structural genes mmoY and mmoZ, coding for the beta- and gamma-subunits of MMO component A, the methane-binding protein . We now report the complete nucleotide (nt) sequence of mmoX, the gene encoding the alpha-subunit of component A which is found to be 5' to mmoY and mmoZ . We also report the complete nt sequence of mmoC which encodes component C, the iron-sulfur flavoprotein of MMO, the N terminus of which is significantly homologous with spinach ferredoxin . The mmo structural genes are clustered within a 7-kb region and are closely linked to two small open reading frames of unknown function. FEBS Lett, 1990 Jul 2, 267(1), 38 - 42 Two-dimensional crystallization of DNA gyrase B subunit on specifically designed lipid monolayers; Lebeau L et al.; The B subunit of DNA gyrase formed two-dimensional crystals when bound to a specifically recognized phospholipid spread into a monolayer at the air/water interface . The especially designed lipids consisted of novobiocin coupled through the 3' or 2" hydroxyl group and a hydrophilous linker of a given length to dioleoylphosphatidic acid . Two-dimensional crystals of the gyrase B subunit are formed under physiological conditions of pH and ionic strength, with no precipitant added to the solution . Crystal diffraction extended to a 2.7 nm resolution in negative stain, with unit cell parameters a = 6.1 nm, b = 7.6 nm and gamma = 64 degrees. J Clin Periodontol, 1990 Jul, 17(6), 364 - 70 Darkground microscopy of subgingival plaque from the top to the bottom of the periodontal pocket; Omar AA et al.; Part of the results of a study of subgingival plaque by darkground microscopy was used to investigate morphotype distribution at different levels within the periodontal pocket . Subgingival plaque was sampled at coronal, middle and apical levels from each of 28 approximal surfaces on 28 teeth extracted from 28 adults with untreated moderate to advanced periodontitis . Sample preparation and darkground microscopy were as described previously . The data recorded only the subgingival level at which the maximum count occurred for a given morphotype and subject . It was found that the maximum count of spirochaetes occurred most frequently at the apical level (p less than 0.05) and the maximum count of 'others' at the coronal level (p less than 0.05) . Also, coccal counts showed a trend to increase the more apical the sample . Standardised darkground microscopy was able to show that the sampled subgingival level had a significant influence on plaque bacterial morphotype distribution, indicating the importance of accurate sampling of subgingival plaque at the most apical level. J Comp Pathol, 1990 Jul, 103(1), 101 - 5 Intestinal lesions resembling paratuberculosis in a wild rabbit (Oryctolagus cuniculus); Angus KW; One of three feral rabbits from a colony on a hill grazing used to sustain farmed red deer in north-east Scotland, had chronic intestinal lesions resembling paratuberculosis (Johne's disease), but similar lesions were not found in 29 juvenile and adult rabbits killed subsequently on the same ground . Acid- and alcohol-fast bacteria were observed in fixed tissues, but material for culture was not obtained from the affected rabbit, thus the species of Mycobacterium involved was not identified . The farmed deer had experienced recently a severe outbreak of paratuberculosis. J Pediatr Gastroenterol Nutr, 1990 Jul, 11(1), 41 - 4 Nodular gastritis and Helicobacter pylori; Bujanover Y et al.; Numerous reports have established the association of Helicobacter pylori and peptic ulcer disease in adults . Recently, this association has also been demonstrated in children . We investigated 14 children and adolescents with recurrent abdominal pain . In six patients, endoscopy revealed gastritis and Helicobacter pylori was identified . Giemsa stain was more sensitive than culture or urease testing in identifying the bacteria . In four of the six, a nodular appearance of the antral mucosa was observed . The histological examination suggests lymphoid hyperplasia as the cause of the nodularity . All of the patients became symptomless after combined treatment with amoxicillin and bismuth subsalicylate . We conclude that nodular gastritis is a peculiar type of gastritis in children . It is frequently found in association with Helicobacter pylori infection. Neuron, 1990 Jul, 5(1), 35 - 48 Brain alpha-bungarotoxin binding protein cDNAs and MAbs reveal subtypes of this branch of the ligand-gated ion channel gene superfamily; Schoepfer R et al.; alpha-Bungarotoxin (alpha Bgt) is a potent, high-affinity antagonist for nicotinic acetylcholine receptors (AChRs) from muscle, but not for AChRs from neurons . Both muscle and neuronal AChRs are thought to be formed from multiple homologous subunits aligned around a central cation channel whose opening is regulated by ACh binding . In contrast, the exact structure and function of high-affinity alpha Bgt binding proteins (alpha BgtBPs) found in avian and mammalian neurons remain unknown . Here we show that cDNA clones encoding alpha BgtBP alpha 1 and alpha 2 subunits define alpha BgtBPs as members of a gene family within the ligand-gated ion channel gene superfamily, but distinct from the gene families of AChRs from muscles and nerves . Subunit-specific monoclonal antibodies raised against bacterially expressed alpha BgtBP alpha 1 and alpha 2 subunit fragments reveal the existence of at least two different alpha BgtBP subtypes in embryonic day 18 chicken brains . More than 75% of all alpha BgtBPs have the alpha 1 subunit, but no alpha 2 subunit, and a minor alpha BgtBP subtype (approximately 15%) has both the alpha 1 and alpha 2 subunits. Proc Natl Acad Sci U S A, 1990 Jul, 87(13), 4895 - 9 Multiple-exposure photographic analysis of a motile spirochete; Goldstein SF et al.; The Leptospiraceae are thin spirochetes with a unique mode of motility . These spiral-shaped bacteria have internal periplasmic flagella that propel the cells in low-viscosity and gel-like high-viscosity media . A model of Leptospiraceae motility has been previously proposed that states that the subterminally attached periplasmic flagella rotate between the outer sheath and the helical protoplasmic cylinder . The shape of the cell ends and the direction of gyration of these ends are determined by the direction of rotation of the internal periplasmic flagella . Rotation of the periplasmic flagella in one direction causes that end to be spiral-shaped, and rotation in the other direction causes that end to be hook-shaped . One prediction of the model is that these right-handed spirochetes roll clockwise when swimming away from an observer . For maximum swimming efficiency, the model predicts that the sense of the spiral-shaped end is left-handed and gyrates counterclockwise . The present study presents direct evidence that the cell rolls clockwise (protoplasmic cylinder helix diameter = 0.24 micron; pitch = 0.69 micron), the ends gyrate counterclockwise, and the spiral-shaped end is left-handed (helix diameter = 0.6 micron; pitch = 2.7 microns)--as predicted by the model . The hook-shaped end appears approximately planar . The approach used was to illuminate stroboscopically cells slowed by Ficoll and analyze the resultant multiple-exposure photographs focused above and below the axis of the cell . The methodology used should be helpful in analyzing the motility of the larger and more complex spirochetes. J Bacteriol, 1990 Jul, 172(7), 3537 - 40 Purification and characterization of formyl-coenzyme A transferase from Oxalobacter formigenes; Baetz AL et al.; Formyl-coenzyme A (formyl-CoA) transferase was purified from Oxalobacter formigenes by high-pressure liquid chromatography with hydrophobic interaction chromatography and by DEAE anion-exchange chromatography . The enzyme was a single entity on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel permeation chromatography (Mr, 44,000) . It had an isoelectric point of 4.7 . The enzyme catalyzed the transfer of CoA from formyl-CoA to either oxalate or succinate . Apparent Km and Vmax values, respectively, were 3.0 mM and 29.6 mumols/min per mg for formyl-CoA with an excess of succinate . The maximum specific activity was 2.15 mumols of CoA transferred from formyl-CoA to oxalate per min per mg of protein. J Infect Dis, 1990 Jul, 162(1), 121 - 6 A mutation in the mip gene results in an attenuation of Legionella pneumophila virulence; Cianciotto NP et al.; Infection by Legionella pneumophila is believed to depend upon its ability to multiply within host alveolar macrophages . To investigate this, a site-specific mutation was introduced into a gene (mip) that encodes a 24,000-Da surface protein; an 80-fold loss of infectivity for both U937 cells and explanted human alveolar macrophages was observed . Further phenotypic analysis of the mutant strain has failed to show alterations in bacterial factors (e.g., proteinase, lipopolysaccharide) that have suspected roles in virulence . To substantiate that this mutation also results in reduced virulence in animals, the lethality and clinical illnesses produced by the parent and mutant L . pneumophila strains were compared in guinea pigs after intratracheal inoculation . The mutant strain produced fewer illnesses, slower-progressing disease, and fewer lethal infections than either the parent strain or a derivative of the mutant strain with the wild-type mip gene reintroduced . When sublethal inocula of the three strains were used, the mutant bacteria were recovered in slightly lower numbers from lung homogenates and in significantly lower numbers from the spleen, at 48 h, than were the other two test strains . Thus mip seems to be necessary for full virulence of L . pneumophila and may represent the first genetically defined virulence factor in this species. Z Naturforsch {C}, 1990 Jul-Aug, 45(7-8), 733 - 8 The ribulose bisphosphate carboxylase/oxygenase of Prochlorothrix hollandica: purification, subunit structure and partial N-terminal sequence analysis of the large subunit; Hawthornthwaite AM et al.; Ribulose bisphosphate carboxylase/oxygenase was purified to apparent homogeneity from the carboxysomes of Prochlorothrix hollandica . The MW of the native enzyme was estimated to be 560,000 Dalton, comprising large subunits (LSU) of 57,000 Dalton and small subunits (SSU) of 13,000, probably in an 8LSU8SSU quaternary structure . Enzyme activity was maximal at pH 8.0 at 30 degrees C . The requirement of activity for Mg2+ could not be replaced by Mn2+ . Co2+, Ca2+ or Cu2+ . Amino acid N-terminal sequence analysis of the LSU showed a high degree of conservation when compared to cyanobacterial and chloroplast LSU sequences but was too short to allow a reliable phylogenetic assignment of P . hollandica. Stomatol DDR, 1990 Jul, 40(7), 299 - 304 {Effectivity of ultrasonics by the root canal instrumentation}; van Gogswaardt DC et al.; The investigative results showed that preparation of root canals is more effective with ultrasonic as compared to hand instrumentation . Areas like diverticula, canal enlargements or side canals were seen to be extremely clean . This is probably due to the effect of cavitation, implosion of small bubbles, the acceleration of minute particles and the formation of ultra sonic waves . The REM investigation showed no residual bacteria . The hand instrumented canals showed pulp remainders in the canal. Zhonghua Wai Ke Za Zhi, 1990 Jul, 28(7), 427 - 9, 447 {Alternation of plasma fibronectin concentration after fracture and relationship with infection}; Sun QB; Plasma fibronectin concentrations were measured in 78 patients with traumatic fracture and 80 healthy people as a control . The results showed that plasma fibronectin concentrations of the patients without complicated infection were significantly decreased 5 to 48 hours after fracture . As comparison with the control, the mean decrease was 56 (16.9%; P less than 0.01), 121 (36.5%; P less than 0.001) and 71 mg/L (21.4%; P less than 0.001) at 5.24 and 48 hours respectively, and restored to the levels of the control at 4 days . In the patients complicated infection, plasma fibronectin concentration was not recovered at 14 days after fracture . The mean decrease was 96 (28.9%; P less than 0.001); 148 (44.6%; P less than 0.001), 119 (35.8%; P less than 0.001), 83 (25.0%; P less than 0.001), 59 (17.8%; P less than 0.01) and 43 mg/L (13.0%; P less than 0.01) at 5.24, 48 hours, 4.7 and 14 days, respectively, as comparison with the control . The results suggest that plasma fibronectin concentrations in the patients with fracture without complicated infection are temporarily decreased and rapidly recovered, but, in the patients with complicated infection, the low fibronectin levels are continued and render the patients more susceptible for bacteria and thus result in complicated infection . Plasma fibronectin can be used as a valuable index to prevent and treat complicated infection after traumatic fracture. Zhonghua Wai Ke Za Zhi, 1990 Jul, 28(7), 410 - 1, 445-6 {Free skin flap for wound infection}; Chen LF; Since 1979, free skin flaps (FSF) have been used for repairing infected wounds in 32 cases with the sequence of 31 cases succeeded and 1 case failed . Among them, 27 cases (84%) were I stage healing and 4 cases (12.5%) were II stage healing . The patients whose infectious surface of wound with exposure of bone, articulation and tendon can not repair with skin grafting or near skin flap were chosen to have this operation . However, the blood vessels in the surface of wound which can be supplied to anastomosis were also necessary . The most important thing for the operation was determination of the opportunity making out the major bacteria infected and debridement entirely . The bigger the blood vessel calibre of FSF selected, the better the surface of wound healing . In this group, 4 cases appeared crisis of blood vessels . Whether it is associated with inflammation of wound is discussed. ASAIO Trans, 1990 Jul-Sep, 36(3), M317 - 20 Sterile versus non-sterile dialysis fluid in chronic hemodialysis treatment; Bambauer R et al.; As the quality of water in the dialysis fluid varies considerably, and in view of the fact that endotoxin or active derivatives can cause acute side effects in patients, the dialysis fluid must be sterile . Therefore, we introduced ultrafiltration of dialysis fluid before entering the dialyzer . Fifteen patients, (ten women, five men) were treated for 4 weeks with nonsterile, and then with sterile dialysis fluid . The bacterial loading in the dialysis fluid before hemodialysis was 1.34 X 10(5)/ml, and after hemodialysis 2.9 X 10(3)/ml; the endotoxin concentration was high and varied between less than 1 EU/ml and greater than 10 EU/ml before and after hemodialysis . After ultrafiltration of the dialysis fluid by a polyamide hollow fiber membrane, all samples were free of bacteria and the concentration of endotoxin was lower than the detectable limit (less than 0.03 and less than 0.5 EU/ml) . With ultrafiltration of dialysis fluid we can obtain sterile dialysate, which is endotoxin free . Interleukin-1 and tumor necrosis factor in the patients with ultrafiltration was significantly lower than without ultrafiltration. Z Gastroenterol, 1990 Jul, 28(7), 327 - 34 {Gastritis: immunohistochemical detection of specific and nonspecific immune response to Helicobacter pylori}; Mollenkopf C et al.; Granulocyte infiltration was studied in 88 biopsies of antrum mucosa from patients with B-gastritis . Evidence of IgA-, IgG- and IgM-antibodies as well as of lysozyme in the mucosa was demonstrated by immunohistochemical methods . Helicobacter pylori (Hp) is coated by antibodies and a significant correlation between extent of opsonisation and number of plasma cells in the connective tissue of the lamina propria could be stated . Thus, the infiltration of plasma cells is a specific immune response against Hp . In the depths of gastric pits the antibody-coating of bacteria is faint . Instead, lysozyme and lactoferrin are produced there . By means of a Cross-sectional study a model is developed which characterizes B-gastritis as a dynamic process . Lagging behind, the inflammation follows the motile bacteria resulting in a patchy distribution of inflamed areas in the mucosa . At the peak of these local inflammation-waves the production of antibodies and lysozyme is intensified . Coating the bacteria with IgG and IgM results in complement activation liberating chemotaxin C5a . Consequently, there is a massive granulocyte infiltration leading to local reduction or eradication of Hp. Gig Sanit, 1990 Jul, (7), 20 - 3 {Changes in biological activity of turf-podzolic soil of different mechanical composition contaminated with heavy metals}; Pertsovskaia AF et al.; It has been shown that soil pollution with heavy metals (copper, nickel) lead to negative changes in parameters characterizing potential biological activity of soil (nitrogen-fixation, breath, invertase activity, bacteria and fungi count) . More profound changes were observed in sandy soil compared to loamy soil . A direct relationship of these effects with the content of mobile forms of heavy metals in soil has been established . For the comparative and prognostic investigation of the danger of soil pollution with heavy metals it has been suggested to use a coefficient of differences in the content of mobile forms and a coefficient of biological effect. Protein Eng, 1990 Jul, 3(7), 577 - 81 Alignment of protein sequences using secondary structure: a modified dynamic programming method; Fischel-Ghodsian F et al.; A method for comparison of protein sequences based on their primary and secondary structure is described . Protein sequences are annotated with predicted secondary structures (using a modified Chou and Fasman method) . Two lettered code sequences are generated (Xx, where X is the amino acid and x is its annotated secondary structure) . Sequences are compared with a dynamic programming method (STRALIGN) that includes a similarity matrix for both the amino acids and secondary structures . The similarity value for each paired two-lettered code is a linear combination of similarity values for the paired amino acids and their annotated secondary structures . The method has been applied to eight globin proteins (28 pairs) for which the X-ray structure is known . For protein pairs with high primary sequence similarity (greater than 45%), STRALIGN alignment is identical to that obtained by a dynamic programming method using only primary sequence information . However, alignment of protein pairs with lower primary sequence similarity improves significantly with the addition of secondary structure annotation . Alignment of the pair with the least primary sequence similarity of 16% was improved from 0 to 37% 'correct' alignment using this method . In addition, STRALIGN was successfully applied to seven pairs of distantly related cytochrome c proteins, and three pairs of distantly related picornavirus proteins. Dent Clin North Am, 1990 Jul, 34(3), 449 - 73 Mechanisms of dentin sensitivity; Pashley DH; This article reviews dentin sensitivity from a mechanistic perspective beginning with short treatments of pulpal innervation, the hydrodynamic considerations of dentin, and how various stimuli may cause pain . Speculation is raised about the contribution of bacteria and their products on dentin sensitivity and how dentin might become truly hypersensitive, especially following periodontal therapy . Wherever possible, the clinical considerations of basic research is stressed. EMBO J, 1990 Jul, 9(7), 2051 - 9 Structure of donor side components in photosystem II predicted by computer modelling; Svensson B et al.; Thirty-one and eleven sequences for the photosystem II reaction centre proteins D1 and D2 respectively, were compared to identify conserved single amino acid residues and regions in the sequences . Both proteins are highly conserved . One important difference is that the lumenal parts of the D1 protein are more conserved than the corresponding parts in the D2 protein . The three-dimensional structures around the electron donors tyrosineZ and tyrosineD on the oxidizing side of photosystem II have been predicted by computer modelling using the photosynthetic reaction centre from purple bacteria as a framework . In the model the tyrosines occupy two cavities close to the lumenal surface of the membrane . They are symmetrically arranged around the primary donor P680 and the distances between the centre of the tyrosines and the closest Mg ion in P680 are around 14 A . Both tyrosineZ and tyrosineD are suggested to form a hydrogen bond with histidine 190 from the loop connecting helices C and D in the D1 and D2 proteins, respectively . The Mn cluster in the oxygen evolving complex has been localized by using known and estimated distances from the tyrosine radicals . It is suggested that a binding region for the Mn cluster is constituted by the lumenal ends of helices A and B and the loop connecting them in the D1 protein . This part of the D1 protein contains a large number of strictly conserved carboxylic acid residues and histidines which could participate in the Mn binding . There is little probability that the Mn cluster binds on the lumenal surface of the D2 protein. J Infect Dis, 1990 Jul, 162(1), 193 - 200 The use of a specific DNA probe and polymerase chain reaction for the detection of Mycobacterium leprae; Williams DL et al.; A DNA probe encoding approximately 80% of the 18-kDa protein gene of Mycobacterium leprae was isolated and tested for specificity by assessing hybridization of the probe to genomic DNA from taxonomically related and unrelated DNA samples . The 360-base-pair (bp) probe was specific for M . leprae DNA and did not hybridize with genomic DNA from 18 species of bacteria nor with DNA from human, murine, and armadillo sources . Oligonucleotide primers were synthesized corresponding to the 5' and 3' ends of the 360-bp fragment to yield a fragment of similar size on amplification of M . leprae DNA by the polymerase chain reaction (PCR) . A simple procedure for DNA extraction from M . leprae-infected tissues was developed that provided suitable template DNA for amplification . The PCR test was specific for M . leprae DNA from human and murine sources and detected M . leprae DNA in biopsies from leprosy patients and from control and uninfected human skin biopsy preparations seeded with as few as 100 M . leprae. J Bacteriol, 1990 Jul, 172(7), 3654 - 60 Purification and characterization of an alpha-glucosidase from a hyperthermophilic archaebacterium, Pyrococcus furiosus, exhibiting a temperature optimum of 105 to 115 degrees C; Costantino HR et al.; Pyrococcus furiosus is a strictly anaerobic hyperthermophilic archaebacterium with an optimal growth temperature of about 100 degrees C . When this organism was grown in the presence of certain complex carbohydrates, the production of several amylolytic enzymes was noted . These enzymes included an alpha-glucosidase that was located in the cell cytoplasm . This alpha-glucosidase has been purified 310-fold and corresponded to a protein band of 125 kilodaltons as resolved by 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis . The enzyme exhibited optimum activity at pH 5.0 to 6.0 and over a temperature range of 105 to 115 degrees C . Kinetic analysis conducted at 108 degrees C revealed hydrolysis of the substrates p-nitrophenyl-alpha-D-glucopyranoside (PNPG), methyl-alpha-D-glucopyranoside, maltose, and isomaltose . Trace activity was detected towards p-nitrophenyl-beta-D-glucopyranoside, and no activity could be detected towards starch or sucrose . Inhibition studies conducted at 108 degrees C with PNPG as the substrate and maltose as the inhibitor yielded a Ki for maltose of 14.3 mM . Preincubation for 30 min at 98 degrees C in 100 mM dithiothreitol and 1.0 M urea had little effect on enzyme activity, whereas preincubation in 1.0% sodium dodecyl sulfate and 1.0 M guanidine hydrochloride resulted in significant loss of enzyme activity . Purified alpha-glucosidase from P . furiosus exhibited remarkable thermostability; incubation of the enzyme at 98 degrees C resulted in a half life of nearly 48 h. Development, 1990 Jul, 109(3), 521 - 31 A positional marker for the dorsal embryonic retina is homologous to the high-affinity laminin receptor; Rabacchi SA et al.; In a search for determinants of positional information in the embryonic eye, we isolated two monoclonal antibodies that label strongly the dorsal part of the undifferentiated embryonic retina in mammals, bird and cold-blooded vertebrates . In the chick, the optic tectum is labeled in a corresponding fashion, the ventral tectum more heavily than the dorsal tectum . Through biochemical and molecular analysis both antibodies were found to recognize a protein that has been cloned repeatedly, first in a screen with antibodies to the '68K-laminin receptor' (Wewer et al . (1986) Cancer Res . 47, 5691-5698), a name that may not exhaustively describe its function . Western blots show the protein to be present in most or all tissues, and Western and Southern blots reveal a high degree of conservation in the detected signals up to invertebrates and bacteria . Despite the very strong and selective labeling of the dorsal retina in conventional immunohistochemical preparations, the protein and its mRNA are present in even amounts throughout the embryonic retina, as demonstrated by Western and Northern blots of bisected retinas, and immunohistochemically in retinas fixed with ethylene glycole bissuccinimide (EGS), an NH2-group crosslinker with very long spacer arm . This indicates that the dorsoventral asymmetry in the embryonic retina is not in the amount but in the configuration of this protein; whether this difference relates to laminin binding is not known. Dtsch Z Mund Kiefer Gesichtschir, 1990 Jul-Aug, 14(4), 297 - 300 {Odontogenic brain abscess . 2 case reports}; Feldges A et al.; The odontogen brain abscess is a relatively rare, but very serious complication of an infection of the teeth . Frequently the bacteria found by aspiration of the brain abscess are the only indication of a dental focus . The diagnostic problems in confirming a covert dental infection as the cause of the brain abscess are illustrated. Zhonghua Kou Qiang Yi Xue Za Zhi, 1990 Jul, 25(4), 194 - 6, 251 {An experimental study of sialin-like anticaries varnish}; Fan MW; The bacteria present in the oral cavity may produce organic acid through actions on sugars, result in a rapid of plaque pH, leading to demineralization . Of the enamel and decay of the tooth . The arginine-containing tetrapeptide in saliva may correct the pH drop . In the present paper we introduced a new varnish that is composed mostly of derivatives of arginine molecule (SL varnish) . This material can prevent pH fall in plaque in vitro and the dissolution of enamel surface after four weeks of cariogenic challenge. Zentralbl Veterinarmed A, 1990 Jul, 37(6), 471 - 6 Effect of organochlorine pesticides on the phagocytic activity of bovine milk cells; Sitarska E et al.; The effect of a complex of organochlorine compounds on the phagocytic activity of macrophages and neutrophils in milk was assessed in vitro using a mixture of DDT, DDE, DDD, alpha, beta and gamma-HCH and HCB and PCBs in concentrations occurring in milk and in concentrations being multiples of the concentrations in milk . Standard strains 305 and Smith of S . aureus were used for phagocytosis assessment . A suppressing effect of these compounds was observed on the per cent of cells phagocytizing both these strains, with a significant decrease in the number of bacteria of both strains phagocytized by macrophages, and the number of S . aureus strain 305 bacteria phagocytized by neutrophils . The concentrations of the mixture of organochlorine compounds used in the experiment had no significant effect on the number of Smith strain bacteria phagocytized by neutrophils. JPEN J Parenter Enteral Nutr, 1990 Jul-Aug, 14(4 Suppl), 109S - 113S Effects of glutamine-supplemented diets on immunology of the gut; Alverdy JC; Recent research developments have identified the gastrointestinal tract as the most metabolically active organ after surgical stress . In addition to fulfilling its role as an organ of digestion and absorption, the gut must maintain immunologic function in order to protect the host from invading pathogens . Central to the function of the intestinal immune system is the expression of secretory IgA, the most abundant immunoglobulin in external secretions . The synthesis and expression of IgA in secretions appear to be sensitive to dietary alteration and may be impaired after surgical stress . Data are presented suggesting that maintenance of gut mass and barrier function to bacteria via dietary manipulation may be essential to ensure host survival during critical illness. JPEN J Parenter Enteral Nutr, 1990 Jul-Aug, 14(4), 353 - 6 Continuous enteral feeding: a major cause of pneumonia among ventilated intensive care unit patients; Jacobs S et al.; Continuous enteral feeding is widely practiced in intensive care units (ICU) . We found that pneumonia developed in 54% of 24 ventilated patients on continuous enteral feeding for more than 3 days . This appeared to affect only patients with a persistently high morning (7:00 am) gastric pH, with 12 of 13 (92%) patients developing pneumonia . In 11 patients the causative organisms were cultured initially from the stomach, oropharynx and trachea before pneumonia supervened . This effect was distinct from that found with the prophylactic use of antacids or H2-receptor antagonists . The mortality (46%) of this group of patients was 1.6 times greater than the expected mortality predicted by the Apache II Severity of Disease Classification System. Appl Environ Microbiol, 1990 Jul, 56(7), 1992 - 8 Characterization of sodium dodecyl sulfate-resistant proteolytic activity in the hyperthermophilic archaebacterium Pyrococcus furiosus; Blumentals II et al.; Cell extracts from Pyrococcus furiosus were found to contain five proteases, two of which (S66 and S102) are resistant to sodium dodecyl sulfate (SDS) denaturation . Cell extracts incubated at 98 degrees C in the presence of 1% SDS for 24 h exhibited substantial cellular proteolysis such that only four proteins could be visualized by amido black-Coomassie brilliant blue staining of SDS-polyacrylamide gels . The SDS-treated extract retained 19% of the initial proteolytic activity as represented by two proteases, S66 (66 kilodaltons {kDa}) and S102 (102 kDa) . Immunoblot analysis with guinea pig sera containing antibodies against protease S66 indicated that S66 is related neither to S102 nor to the other proteases . The results of this analysis also suggest that S66 might be the hydrolysis product of a 200-kDa precursor which does not have proteolytic activity . The 24-h SDS-treated extract showed unusually thermostable proteolytic activity; the measured half-life at 98 degrees C was found to be 33 h . Proteases S66 and S102 were also resistant to denaturation by 8 M urea, 80 mM dithiothreitol, and 5% beta-mercaptoethanol . Purified protease S66 was inhibited by phenylmethylsulfonyl fluoride and diisopropyl fluorophosphate but not by EDTA, ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, or iodoacetic acid . These results indicate that S66 is a serine protease . Amino acid ester hydrolysis studies showed that protease S66 was hydrolytically active towards N-benzoyl-L-arginine ethyl ester. Heart Lung, 1990 Jul, 19(4), 362 - 70 Contamination of enteral feedings and diarrhea in patients in intensive care units; Mickschl DB et al.; To investigate the effect of contamination of enteral feeding solutions on the incidence of diarrhea in critically ill patients, 36 adult intensive and coronary care unit patients received enteral feeding by an aseptic or a routine protocol . Cultures of formula were obtained on the first 4 days of enteral feeding . A significantly greater incidence of contamination was found for the routine protocol group than for the aseptic protocol group (p less than 0.05); however, differences in incidence of diarrhea between subjects who did and did not receive contaminated formula were not significant . Subjects who had diarrhea also had significantly lower (p less than 0.05) serum albumin and transferrin levels . The effects of severity of illness, osmolality, and rate of formula administration on incidence of diarrhea were investigated, and these were not found to be significant factors . Implications for nursing practice and further research are generated. Rev Med Interne, 1990 Jul-Aug, 11(4), 333 - 5 {Turner's syndrome and autoimmune dysthyroidism}; Ortega F et al.; The authors report a case of Turner's syndrome associated with Hashimoto's thyroiditis and present the various physiopathological hypotheses currently offered to explain the frequent association of an autoimmune pathology and a gonadal dysgenesis with an absence of X chromosome which is held responsible for autoimmunity . Is the chromosomal abnormality a factor predisposing to autoimmunity or does it result from a disturbance of the immune mechanism? Environmental factors, such as bacteria, viruses or some pollutants might be responsible for both the immune disorders and the chromosomal abnormality . The association of the two types of disease may also be accidental . In the present state of our knowledge, there is no answer to these questions. J Endod, 1990 Jul, 16(7), 342 - 5 Failure of endodontic treatment due to a palatal gingival groove in a maxillary lateral incisor with talon cusp and two root canals; Fabra-Campos H; A case is presented in which endodontic treatment of a maxillary lateral incisor with a talon cusp and two root canals failed following a mistaken diagnosis . What was first diagnosed as an endodontic lesion was, in all probability, a primary periodontal lesion caused by the advance of