Determination of 16S ribosomal RNA sequences of all members of the genus Peptostreptococcus and their phylogenetic position

A comparative analysis of 16S ribosomal RNA sequences of all Peptostreptococcus species revealed that most members of the genus Peptostreptococcus should be divided into many different genera. The relationship between clostridia and peptostreptococci was analysed to find the phylogenetic position of peptostreptococci.

[Overexpression of c-erbB-2 proto-oncogene product in chondrosarcomas]

The c-erbB-2 proto-oncogene plays an important role in the regulation of cellular proliferation and differentiation. Overexpression of c-erbB-2 proto-oncogene product in 40 cases of chondrosarcomas was investigated using ABC immunoperoxidase method. Overexpression of c-erbB-2 product was present in 36/40 (90%) chondrosarcomas and in 1/9 (11%) benign cartilage tumors. Normal cartilage tissue gave negative results. These findings indicate that c-erbB-2 proto-oncogene product has practical value in diagnosing chondrosarcomas. c-erbB-2 positive grading showed a significant inverse correlation with the histopathological grading. Chondrosarcomas with high histological grade and poor differentiation showed a bias toward a decline in expression of c-erbB-2 product. The c-erbB-2 proto-oncogene product may be used as a differentiation marker.

16S ribosomal DNA sequences of anaerobic cocci and proposal of Ruminococcus hansenii comb. nov. and Ruminococcus productus comb. nov

The 16S ribosomal DNA sequences of representative members of the family Peptococcaceae were determined. The members of the family examined were divided into the following four phylogenetic groups: Peptococcus niger ATCC 27731T (T = type strain), the Sarcina-Peptostreptococcus anaerobius group, the ruminococcus-coprococcus group, and the peptostreptococcus group. Peptococcus niger, the type species of the family, was not related to other members of the family. Peptostreptococcus anaerobius ATCC 27337T, the type strain of the type species of the genus Peptostreptococcus, was closely related to Clostridium sordellii NCIB 10717T (level of sequence similarity, 85%). Sarcina ventriculi GIFU 7886, a spore-forming anaerobic gram-positive coccus, clustered with Clostridium perfringens ATCC 13124T at a similarity value of 91%. Members of the Sarcina-Peptostreptococcus anaerobius group clustered with clostridia at similarity values ranging from 85 to 91%. The type strains of Peptostreptococcus prevotii, Peptostreptococcus asaccharolyticus, Peptostreptococcus micros, and Peptostreptococcus magnus clustered at levels of sequence homology of 84 to 93%. This cluster was not included in the Peptococcus niger group or the Peptostreptococcus anaerobius group. Thus, these members of the genus Peptostreptococcus should be separated from the other members of the genus and also from members of the family Peptococcaceae. The sequence of Peptostreptococcus productus ATCC 27340T was different from the sequences of Peptostreptococcus anaerobius and Peptococcus niger. The sequence of Streptococcus hansenii ATCC 27752T, a strictly anaerobic strain, was different from the sequences of other streptococci; this strain clustered with Peptostreptococcus productus, coprococci, and ruminococci. Several phenotypic characteristics of Streptococcus hansenii ATCC 27752T were similar to characteristics of ruminococci.(ABSTRACT TRUNCATED AT 250 WORDS)

An outbreak of hepatitis A among health care workers: risk factors for transmission

OBJECTIVES

The purpose of this study was to investigate a nosocomial outbreak of hepatitis A that occurred in the burn treatment center of a referral hospital.

METHODS

Retrospective cohort and case-control studies were performed to determine acquisition rates and risk factors for transmission. Adjusted infection rates were calculated by week of exposure. A case-control study was conducted to determine potential mechanisms for nosocomial acquisition. Recently infected health care workers were defined as case patients; exposed, serosusceptible health care workers without infection served as controls.

RESULTS

The outbreak of hepatitis A affected 11 health care workers and 1 other burn patient (1 secondary patient case). All 11 health care workers became ill after the admission of a man and his 8-month-old son who developed hepatitis A while in the hospital. The cumulative incidence risk ratio was elevated for health care workers caring for either the infant or the father during the same week of exposure. The case-control study implicated the behavior of eating on the hospital ward as the single most important risk factor for infection.

CONCLUSION

Inadequate hand-washing and subsequent oral contamination appear responsible for the outbreak. Hospitals may witness other institutional outbreaks if health care workers regularly eat on the wards.

Association of secondary and polymicrobial nosocomial bloodstream infections with higher mortality

The objective of this study was to characterize microbiological factors independently associated with higher mortality rates following nosocomial bloodstream infection. All patients admitted to the University of Iowa Hospitals and Clinics between 1 July 1989 and 30 June 1990 who developed a nosocomial bloodstream infection were included. The crude in-house mortality for the 364 patients with nosocomial bloodstream infections was 33%. These deaths accounted for 25% of all in-hospital deaths. Significant risk factors for death from bloodstream infection included diagnoses of cancers and diseases of the cardiovascular and respiratory systems (p < 0.01). Neither previous surgery nor neutropenia was associated with higher mortality rates. Whereas the crude mortality rates associated with gram-negative (33%) and gram-positive (31%) bloodstream infections were similar, that associated with fungemia was higher (54%, p < 0.02). The mortality associated with secondary bloodstream infections (46%) was higher than that associated with primary bloodstream infections (28%, p < 0.001). Furthermore, polymicrobial infections had a worse prognosis than infections from which a single pathogen was isolated (p < 0.05). A multivariate, logistic regression model identified four variables that independently predicted mortality (p = 0.025): age (OR 1.01 per year; CI95 1.00-1.02); cancer (OR 2.35, CI95 1.26-4.37) or diseases of the cardiovascular or respiratory systems (OR 2.20, CI95 1.04-4.67); polymicrobial infection (OR 2.34; CI95 1.21-4.53); and secondary bloodstream infection (OR 2.46; CI95 1.50-4.02). The last variable was the strongest independent predictor. Our study demonstrates the importance of microbiological factors in the outcome of nosocomial bloodstream infections.

BCR-ABL-induced oncogenesis is mediated by direct interaction with the SH2 domain of the GRB-2 adaptor protein

BCR-ABL is a chimeric oncoprotein that exhibits deregulated tyrosine kinase activity and is implicated in the pathogenesis of Philadelphia chromosome (Ph1)-positive human leukemias. Sequences within the first exon of BCR are required to activate the transforming potential of BCR-ABL. The SH2/SH3 domain-containing GRB-2 protein links tyrosine kinases to Ras signaling. We demonstrate that BCR-ABL exists in a complex with GRB-2 in vivo. Binding of GRB-2 to BCR-ABL is mediated by the direct interaction of the GRB-2 SH2 domain with a phosphorylated tyrosine, Y177, within the BCR first exon. The BCR-ABL-GRB-2 interaction is required for activation of the Ras signaling pathway. Mutation of Y177 to phenylalanine (Y177F) abolishes GRB-2 binding and abrogates BCR-ABL-induced Ras activation. The BCR-ABL (Y177F) mutant is unable to transform primary bone marrow cultures and is impaired in its ability to transform Rat1 fibroblasts. These findings implicate activation of Ras function as an important component in BCR-ABL-mediated transformation and demonstrate that GRB-2 not only functions in normal development and mitogenesis but also plays a role in oncogenesis.

Chronic tonsillitis and IgA nephropathy

The authors studied the effect of tonsillectomy for IgA nephropathy and the relationship between chronic tonsillitis and IgA nephropathy. Forty-five patients with IgA nephropathy were treated by tonsillectomy in our department. The effective rate of hematuria type IgA nephropathy was 86.2% and that of non-hematuria type 62.5%. We also determined the immunoglobulin composition of the tonsilla tissue in 18 IgA nephropathy patients and compared it with that of 18 chronic tonsillitis patients. The immunoglobin level of the IgA nephropathy group was higher than that of the contrast group, indicating that the disorder of tonsilla immunity may be one of the pathogenic factors for IgA nephropathy. Since no specific method has been available for the treatment of IgA nephropathy, we use tonsillectomy as an effective procedure.

[Vascular malformation of posterior cerebral artery in supertentorium]

Seventeen cases of vascular malformation of posterior cerebral artery in supertentorium from 1973 to 1991 are reported. These patients accounted for 8.8% of the total supertentorial vascular malformations during the same period. Their ages ranged from ten to forty-eight years with an average of thirty-one years. The vascular malformation was located in the occipital lobe or under the temporal lobe. Its main blood supply was from the basilar artery. Headache and hemorrhage were common clinical manifestations. Some cases had a defect of the visual field. Vertebral angiography is necessary for diagnosis of this disease. All the seventeen cases were operated without any death. The operative approach and experience in seeking for the vascular malformation during the operation are discussed.

Complete nucleotide sequence and molecular characterization of ViaB region encoding Vi antigen in Salmonella typhi

Plasmid pGBM124, which contains a 14-kb Salmonella typhi chromosomal DNA fragment capable of producing the Vi antigen in Escherichia coli HB101 and ViaB-deleted S. typhi GIFU 10007-3, was studied. We determined the complete nucleotide sequence of this fragment and found 11 open reading frames. Mutagenesis, subcloning, and complementation analysis showed that three genes (vipA, vipB, and vipC) are involved in biosynthesis of the Vi polysaccharide. The putative primary amino acid sequence suggests that both vipA and vipB encode the NAD- or NADP-dependent enzymes to synthesize the nucleotide sugar for the Vi polysaccharide. Five genes (vexA, vexB, vexC, vexD, and vexE) may be involved in translocation of the Vi polysaccharide. Proteins VexA, VexB, VexC, and VexD had moderate similarities to components of group II capsule transporters, and the VexC protein had a putative ATP-binding site. These data indicate that the transport system for the Vi polysaccharide belongs to the ATP-binding cassette transporters. By using the isogenic Vi+ and Vi- strains constructed in this study, we reconfirmed that the Vi antigen is necessary for the serum resistance of S. typhi.

Proliferative effect of mevalonate metabolites other than isoprenoids on cultured vascular smooth muscle cells

1. Recent investigations revealed that isoprenoid compounds serve as key substances for cellular proliferation through post-translational modification. Previously we reported that tissues of spontaneously hypertensive rats (SHR) had a lower activity of isoprenoid biosynthesis when compared with the normotensive control rat (WKY). However, cultured vascular smooth muscle cells (VSMC) of SHR showed an enhanced growth rate. These findings led us to investigate further the effect of isoprenoid compounds on VSMC proliferation. 2. When the cells of WKY were stimulated with 5% fetal calf serum (FCS) in the presence of lovastatin, [3H]-thymidine incorporation decreased in a dose-dependent manner and was completely inhibited at 30 mumol/L. Exogenously added mevalonate showed a protective effect against lovastatin (81% protection at 0.1 mumol/L). 3. Fluoromevalonate (Fmev), an inhibitor of mevalonate-PP decarboxylase which converts mevalonate-PP into isoprenoids, showed a dual inhibitory effect. DNA synthesis was partially inhibited at 0.01-1 mumol/L, however at 10 mumol/L there was no detectable inhibition. The inhibitory effect was again observed at concentrations over 10 mumol/L. 4. In the presence of lovastatin and Fmev to block both HMG CoA reductase and mevalonate-PP decarboxylase, exogenous mevalonate dose dependently stimulated [3H]-thymidine incorporation induced by FCS. 5. These data suggest the positive effect of the initial mevalonate derivatives other than isoprenoid compounds on the proliferation of VSMC.

The function of GRB2 in linking the insulin receptor to Ras signaling pathways

Insulin-induced activation of extracellular signal-regulated kinases [ERKs, also known as mitogen-activated protein (MAP) kinases] is mediated by Ras. Insulin activates Ras primarily by increasing the rate of guanine nucleotide-releasing activity. Here, we show that insulin-induced activation of ERKs was enhanced by stable overexpression of growth factor receptor-bound protein 2 (GRB2) but not by overexpression of GRB2 proteins with point mutations in the Src homology 2 and 3 domains. Moreover, a dominant negative form of Ras (with Ser17 substituted with Asn) blocked insulin-induced activation of ERKs in cells that overexpressed GRB2. GRB2 overexpression led to increased formation of a complex between the guanine nucleotide-releasing factor Sos (the product of the mammalian homolog of son of sevenless gene) and GRB2. In response to insulin stimulation, this complex bound to tyrosine-phosphorylated IRS-1 (insulin receptor substrate-1) and Shc. In contrast to the activated epidermal growth factor receptor that binds the GRB2-Sos complex directly, activation of the insulin receptor results in the interaction of GRB2-Sos with IRS-1 and Shc, thus linking the insulin receptor to Ras signaling pathways.

[The phytohemagglutinins and soybean agglutinin in diagnosis of endometrial adenocarcinoma]

The distribution of PHA and SBA receptors was studied by ABC immunoperoxidase method in 30 cases of endometrial adenocarcinoma (EA), 10 cases of normal endometrium (NE) and 20 cases of cystic glandular hyperplastic endometrium (CGH). The results showed that the positive rate of PHA and SBA in EA was 46.67% and 73.33% respectively, but negative and low in NE and CGH (P < 0.05). PHA and SBA showed a progressive rising tendency along with the changes of NE to CGH and EA (P < 0.01). It is suggested that both PHA and SBA may be used as differentiated markers in EA and may be helpful in clinical diagnosis.

Guanine-nucleotide-releasing factor hSos1 binds to Grb2 and links receptor tyrosine kinases to Ras signalling

Many of the actions of receptor tyrosine kinases are mediated by the protein Ras, including the activation of various downstream serine/threonine kinases and the stimulation of growth and differentiation. The human protein Grb2 binds to ligand-activated growth factor receptors and downstream effector proteins through its Src-homology (SH) domains SH2 and SH3, respectively, and like its homologue from Caenorhabditis elegans, Sem-5, apparently forms part of a highly conserved pathway by which these receptors can control Ras activity. Here we show that the SH3 domains of Grb2 bind to the carboxy-terminal part of hSos1, the human homologue of the Drosophila guanine-nucleotide-releasing factor for Ras, which is essential for control of Ras activity by epidermal growth factor receptor and sevenless. Moreover, a synthetic 10-amino-acid peptide containing the sequence PPVPPR specifically blocks the interaction. These results indicate that the Grb2/hSos1 complex couples activated EGF receptor to Ras signalling.

Importance of pre-existing co-morbidities for prognosis of septicemia in critically ill patients

OBJECTIVE

To determine admission characteristics associated with the outcome of septicemia in critically ill patients and more specifically assess the prognostic value of pre-existing co-morbidities.

DESIGN

5 year-retrospective cohort study.

SETTING

Surgical Intensive Care Unit (ICU-20 beds) in a 1600 bed-tertiary care center.

PATIENTS

Among 5457 patients admitted to the ICU between 1984 and 1988, 176 (3.2%) met prospectively-defined criteria for blood culture-proven septicemia (8.77 per 1000 patient-days). Overall septicemic patients had a 5-fold increased risk of death compared to non-septicemic patients (relative risk 5.03, 95% confidence intervals 4.17-6.07, p < 0.0001), and this estimate persisted after stratification according to age, sex, primary diagnosis and conditions of admission to the ICU (emergency/elective).

RESULTS

Prognostic factors recorded on admission to ICU that were associated with mortality from septicemia among 173 patients were older age, higher admission Apache II score, gastrointestinal surgery, ultimately and rapidly fatal diseases and the number of co-morbidities in addition to the principal diagnosis (active smoking, alcohol abuse, non-cured malignancy, diabetes mellitus, splenectomy, recent antibiotic therapy, major surgery, or major cardiac event). In the multivariate analysis with logistic regression procedures, Apache II and co-morbidities were identified as the two independent predictors of mortality.

CONCLUSIONS

Pre-existing co-morbidities assessed at the admission to the ICU significantly improved the prediction of mortality from septicemia compared to Apache II score alone.

[Measurement of the single muscle fiber action potentials and jitter value in tibialis anterior muscles of rabbits in situ]

With a home-made jitter data processing board and microcomputer for recording extracellular single fiber action potential (SF-AP), variations of the time intervals of the SF-AP pairs, or the jitters, from two adjacent muscle fibers in the unique motor unit in tibialis' anterior in response to repeated stimuli were measured. The jitter distribution of 936 recorded from 7 rabbits was positively showed with a percentile value of P75-P25 of 54.99-14.61 microseconds. The data suggested that the lower limit was smaller than that of skeletal muscles in normal human and that there exists also some differences in the jitter values of SFEMG between human and rabbit muscles.

Successful segmental small bowel allotransplantation in pigs

The two step small-bowel transplantation was performed experimentally in pigs. Both ends of heterotopic segmental allografts of 100 cm small bowel were enterostomized during the first operation. After 4-6 weeks, the allograft was interposed in the continuity of the intestine. Rejection was developed in Group I (n = 6) without immunosuppression. The mean survival time of the grafts was 17.7 +/- 7.6 days, and recipients were alive after resection of necrotic grafts. The animals of Group II (n = 6) were treated by cyclosporine concomitantly with azathioprine and methylprednisolone. Two pigs were killed for severe pneumonia on day 92, 97 and the grafts were alive, the other four recipients and their grafts survived for more than 300 days, 270 days, 260 days and 260 days respectively. No GVHD was observed and rejection was the major problem in segmental intestinal transplantation.

Isolation and sequence analysis of variant forms of human transcobalamin II

Two cDNA clones (1.9 kb and 1.5 kb, respectively) encoding full length human TC II have been isolated from a human endothelial cell cDNA library and sequenced. The differences between the two clones are the length of the 5' end and the 3' end non-coding regions and the codon at position 198 and 219. Both the clones differ from the recently isolated (human endothelial cell) cDNA for TC II (Platica, O., Janecko, R., Quadros, E.V., Regee, A., Romain, R. and Rothenberg, S.P. (1991) J. Biol. Chem. 266, 7860-7863) in codon 259 and 376 and in their calculated pI values. In vitro transcription followed by translation in a reticulocyte lysate system and SDS-PAGE revealed that the isolated cDNA clones encode a protein of 43 kDa. Upon treatment with canine pancreatic microsomes, the molecular mass of the in vitro translated product was reduced to 41.5 kDa, indicating the presence of an approximately 1.5 kDa signal peptide. This translation product was immunoprecipitated with rabbit anti-serum to human TC II and was able to bind to Cbl-Sepharose beads. The amino acid sequence alignment of TC II with that of other Cbl binding proteins (rat intrinsic factor, human transcobalamin I and porcine haptocorrin) revealed only 33% overall homology. However, there were four regions of greater than 80% homology and two regions of about 60% homology. These regions encompass the majority of the hydrophobic areas of the Cbl-binders. Based on these studies, we suggest that structural basis for the expression of different polymorphic forms of TC II may be due to single point mutations and that TC II, like other mammalian Cbl-binders, have evolved from a common ancestral gene. Furthermore, the Cbl-binding functional domain most probably resides in a hydrophobic pocket which is formed by all or some of the six regions of high homology.

The prevalence of coronary heart disease in the multi-ethnic and high diabetes prevalence population of Mauritius

The prevalence of coronary heart disease (CHD) was determined in a population survey in Mauritius where the prevalence of non-insulin dependent diabetes and mortality from CHD are amongst the highest in the world. Men and women aged 35-74 years of all major ethnic groups were included: Asian Indians (Hindus and Muslims), Creoles and Chinese. ECG abnormalities suggesting either 'probable CHD' or 'possible CHD' were defined using standard criteria. The overall prevalence of probable CHD was 2.7% in men and 0.9% in women, and that of probable or possible CHD together 17.8% in men and 33.3% in women. The prevalence of CHD did not vary significantly between the four ethnic groups. In the multivariate analyses, age and high blood pressure were the most important independent predictors of ECG abnormalities. Neither diabetes nor serum insulin seemed to contribute independently to the prevalence of CHD. This survey confirmed the high ranking of Mauritius in international mortality statistics. The high rates of CHD seen in Asian Indians, African-origin Creoles and Chinese in the rapidly developing country of Mauritius may be a pointer to future problems in their regions of origin.

Covalently immobilized DNA plate for luminometric DNA-DNA hybridization to identify viridans streptococci in under 2 hours

Single-stranded chromosomal DNA was covalently bound to a microdilution plate and used for quantitative DNA-DNA hybridization. After 30 min, hybridized DNA was quantitatively detected by alkaline phosphatase and a chemiluminescent substrate. This method was successfully used for the rapid identification of viridans streptococci.

[Proliferating cell nuclear antigen (PCNA/cyclin) in gastric carcinoma in relation to its prognosis]

Expression of proliferating cell nuclear antigen (PCNA/Cyclin) in 73 cases of gastric carcinomas and its relationship to prognosis were semiquantitatively analysed by ABC immunoperoxidase method and its clinical application was explored. PCNA staining located in the nuclei of tumor cells. A semiquantitative PCNA grading showed a significant negative correlation with survival of the gastric carcinomas cases (P < 0.01). Survival analysis also presented that the prognosis of patients with intensive expression of PCNA was poor. Generally speaking, the expression of PCNA showed a significant positive correlation with the differentiation degree of the tumor and nodal metastasis (P < 0.05). However, among these cases, the poorly differentiated adenocarcinomas with a weak grade of PCNA expression generally considered as of a high malignant degree and poor prognosis, survived longer. The facts indicated that the in situ detection of PCNA in gastric carcinoma is more objective and reliable in assessing a proper prognosis than that made on the basis of traditional morphological differentiation grading.

Phosphorylation and ubiquitination of the 26S proteasome complex

This article reviews recent studies from our laboratory on protein regulators of the proteasome (multicatalytic proteasome complex) in red blood cells. A 240-kD inhibitory component (CF-2) exists in 26S proteasome complexes in a form which is conjugated to ubiquitin. Interestingly, this factor was shown to be identical to delta-aminolevulinic acid dehydratase (ALAD), involved in heme synthesis. A distinct 200-kD inhibitor of the proteasome is not present in the 26S complex. A 32-kD subunit of the 20S proteasome appears to be important for the latency of this core protease. Multiple isoelectric variants of the 32-kD subunit are consistent with phosphorylation. Another 20S proteasome subunit of 30 kD molecular weight is phosphorylated at specific serine residues by copurifying casein kinase II. It is suggested that ubiquitination and phosphorylation may account for at least part of the ATP dependency associated with the 26S proteasome complex. These modifications may play a role in the activity, assembly, translocation and/or turnover of this particle.

Homonuclear broad-band-decoupled chemical shift imaging by singular value decomposition with optimization

The conventional viewpoint of localized NMR spectroscopy is to acquire spectral information through time-domain data, while leaving spatial information to phase encoding by incremental magnetic field gradients. A second viewpoint, much less frequently used, places the emphasis on the acquisition of spatially well-resolved images by conventional means, leaving the chemical shift segregation through phase encoding in the incremental t(1) period (in a 2-DNMR parlance). The feasibility and practicality of the second viewpoint are demonstrated by implementation of a modified version of the SLIM technique, which was originally designed for the first viewpoint, using simulated and real phantom data with optimization of the t(1)-encoding parameters.

[Relationship between Langerhans cells and prognosis of patients with gastric carcinoma]

Langerhans cells (LCs) in 73 cases of gastric carcinomas (GC) were quantitatively investigated by ABC immunohistochemical method using anti-S-100 protein antibody. The mean density of LCs (cell numbers/mm2) infiltrating the carcinomas showed an intimate relationship with the prognosis (P < 0.01) and the status of lymph node (LN) metastasis (P < 0.05). The density of LCs in patients without LN metastasis was significantly higher than that with LN metastasis. In 73 cases of GC, there were 35 cases of LCs(+) and 38 of LCs(++) groups. The mean survival times were 29.81 months in the former and 52.21 months in the latter. A significant relationship (P < 0.05) between the survival and degree of the density of LCs was showed by Student's t test and life table method. There were no correlation among the density of LCs and gross appearance, depth of invasion, histologic type and patients' sex. The fact indicated that LCs may play an important role in immunological defense mechanisms of host against the tumor. Patients with dense infiltration of LCs survived longer and showed less LN metastasis than those without such an infiltration. It is considered that measurement of LCs in specimens of GC may be taken as one of criteria of prognosis.

Three new species of the genus Peptostreptococcus isolated from humans: Peptostreptococcus vaginalis sp. nov., Peptostreptococcus lacrimalis sp. nov., and Peptostreptococcus lactolyticus sp. nov

We describe three new species of the genus Peptostreptococcus which were isolated from human specimens and were tentatively identified as Peptostreptococcus prevotii. These three organisms were not homologous with previously described type strains of the genus Peptostreptococcus. A total of 12 strains that were identified biochemically as P. prevotii were divided into five independent DNA similarity groups; 10 of these strains were divided into three similarity groups which exhibited significant phenotypic differences from previously described species. Therefore, we propose the following new species: Peptostreptococcus vaginalis for group 1 strains, Peptostreptococcus lacrimalis for group 2 strains, and Peptostreptococcus lactolyticus for group 3 strains. The type strain of P. vaginalis is strain GIFU 12669 (= JCM 8138), the type strain of P. lacrimalis is strain GIFU 7667 (= JCM 8139), and the type strain of P. lactolyticus is strain GIFU 8586 (= JCM 8140).

[Pulmonary function disturbances in patients with hepatic cirrhosis]

The results of five pulmonary function tests on 52 patients with uncompensated hepatic cirrhosis were presented. Compared with matched healthy adults, the patients had decreased values of VC, TLC and DLCO, and their RV/TLC increased (P < 0.05-0.001). Possible pathogenic factors were investigated. The ascites showed evident influences on pulmonary function. In addition to the disorders detected by the above 4 tests, FRC decreased in the patients with ascites. A comparison between the patients with albumin below 30g/L and the patients with albumin above 30g/L revealed that reduced plasma albumin also played role in decreasing VC, TLC and DLCO. Besides the effects of ascites, severe varices of esophagus should have relation to the increase of RV/TLC and the decrease of DLCO.

[Traumatic external gastrointestinal fistula: report of 77 cases]

Seventy-seven patients developed gastroenteric fistula as a complication of abdominal trauma, including small bowl fistula (25), duodenal fistula (17), colonic fistula (16), pancreatic fistula (3), gastric fistula (2), and multiple fistula (14). These patients accounted for 15.9% (77/483) of all patients with intestinal fistula treated in the same period in our department. An average of 8.8 days had elapsed before the final diagnosis of GI fistula was made, during which 73 patients had 1-8 kinds of complications, 48 received 1-5 operations, and 67 were given nutritional support for 6 to 254 days. Thirty patients were cured operatively and 33 (52.4%) spontaneously. The mortality was 18.2%. The etiology, principles of prevention, and management of traumatic intestinal fistula were discussed with emphasis on effective nutritional support and intraabdominal drainage.

Point mutation in FGF receptor eliminates phosphatidylinositol hydrolysis without affecting mitogenesis

Stimulation of growth factor receptors with tyrosine kinase activity is followed by rapid receptor dimerization, tyrosine autophosphorylation and phosphorylation of signalling molecules such as phospholipase C gamma (PLC gamma) and the ras GTPase-activating protein. PLC gamma and GTPase-activating protein bind to specific tyrosine-phosphorylated regions in growth factor receptors through their src-homologous SH2 domains. Growth factor-induced tyrosine phosphorylation of PLC gamma is essential for stimulation of phosphatidylinositol hydrolysis in vitro and in vivo. We have shown that a short phosphorylated peptide containing tyrosine at position 766 from a conserved region of the fibroblast growth factor (FGF) receptor is a binding site for the SH2 domain of PLC gamma (ref. 8). Here we show that an FGF receptor point mutant in which Tyr 766 is replaced by a phenylalanine residue (Y766F) is unable to associate with and tyrosine-phosphorylate PLC gamma or to stimulate hydrolysis of phosphatidylinositol. Nevertheless, the Y766F FGF receptor mutant can be autophosphorylated, and can phosphorylate several cellular proteins and stimulate DNA synthesis. Our data show that phosphorylation of the conserved Tyr 766 of the FGF receptor is essential for phosphorylation of PLC gamma and for hydrolysis of phosphatidylinositol, but that elimination of this hydrolysis does not affect FGF-induced mitogenesis.

[Research of lectin receptors in early gastric carcinoma]

Sixty cases of early gastric carcinoma (EGC) were studied to identify the receptors against lectins (ConA, DBA, PHA, PNA, and WGA) respectively by means of immunohistochemical ABC technique. The result obtained was coincidently compared with the figures of carcinoembryonic antigen (CEA). Immunoelectronmicroscopy was carried out on four cases with freshly prepared gastric carcinoma specimens in order to observe the distribution of these 5 lectin receptors by using streptavidin-gold complex method. The results were as follows: the gold particles labelled for 5 lectin receptors were mainly located on the cytoplasmic membrane, organelle membrane and the mucin granules. The distribution and the intensity of positive reaction were known to be correlated with histologic typing, histogenesis and the degree of cell differentiation of EGC, PHA, PNA and WGA staining for the corresponding receptors were considered of some value in the diagnosis of gastric carcinoma.

A functional tomato ACC synthase expressed in Escherichia coli demonstrates suicidal inactivation by its substrate S-adenosylmethionine

1-Aminocyclopropane-1-carboxylate (ACC) synthase is a key enzyme in the biosynthesis of the plant hormone, ethylene. We have isolated, sequenced and expressed a functional tomato (cv Pik-Red) ACC synthase gene in Escherichia coli. ACC synthase expressed in E. coli was inactivated by incubation with S-adenosylmethionine (SAM), the half-time of which was concentration dependent. Mixing the tomato fruit protein extract with the cell-free extract from transformed E. coli did not affect SAM-dependent inactivation of ACC synthase activity. Thus, single isoforms of the ACC synthase enzyme, which demonstrate the biochemical features expected of the tomato fruit enzyme, can be expressed in E. coli and their structure-function relationships investigated.

Comparative efficacy of alternative hand-washing agents in reducing nosocomial infections in intensive care units

BACKGROUND

Effective hand-washing can prevent nosocomial infections, particularly in high-risk areas of the hospital. There are few clinical studies of the efficacy of specific hand-cleansing agents in preventing the transmission of pathogens from health care workers to patients.

METHODS

For eight months, we conducted a prospective multiple-crossover trial involving 1894 adult patients in three intensive care units (ICUs). In a given month, the ICU used a hand-washing system involving either chlorhexidine, a broad-spectrum antimicrobial agent, or 60 percent isopropyl alcohol with the optional use of a nonmedicated soap; in alternate months the other system was used. Rates of nosocomial infection and hand-washing compliance were monitored prospectively.

RESULTS

When chlorhexidine was used, there were 152 nosocomial infections, as compared with 202 when the combination of alcohol and soap was used (adjusted incidence-density ratio [IDR], 0.73; 95 percent confidence interval, 0.59 to 0.90). The largest reduction with chlorhexidine was in gastrointestinal infections (IDR, 0.19; 95 percent confidence interval, 0.05 to 0.64). When chlorhexidine was available, the rates of nosocomial infection declined in each of the ICUs, and health care workers washed their hands more often than when alcohol and soap were used (relative risk, 1.28; 95 percent confidence interval, 1.02 to 1.60). The total volume of alcohol and soap used was 46 percent that of chlorhexidine (P less than 0.001).

CONCLUSIONS

A hand-disinfection system using an antimicrobial agent (chlorhexidine) reduces the rate of nosocomial infections more effectively than one using alcohol and soap. The improvement may be explained at least in part by better compliance with hand-washing instructions when chlorhexidine was used.

Electrocardiographic abnormalities and associated factors in Chinese living in Beijing and in Mauritius. The Mauritius Non-Communicable Disease Study Group

OBJECTIVE

To compare the prevalence of electrocardiographic abnormalities and to evaluate the association between these abnormalities and the levels of coronary heart disease among Chinese living in different environments.

DESIGN

Cross sectional surveys.

SETTING

Beijing, China, and the island of Mauritius.

SUBJECTS

Random samples of people aged 35-64 years in Beijing (621 men, 642 women) in 1984 and in Mauritius among Chinese (137 men, 130 women) and non-Chinese (1265 men, 1432 women) in 1987.

MAIN OUTCOME MEASURES

Prevalence of electrocardiographic abnormalities suggesting coronary heart disease and of associated risk factors.

RESULTS

Prevalence of electrocardiographic abnormalities suggesting coronary heart disease was significantly lower in Beijing (4.0%) than in Mauritian Chinese (24.3%) and Mauritian non-Chinese (24.5%). Mean serum concentrations of total and non-high density lipoprotein cholesterol were lower in Beijing Chinese than in Mauritian Chinese, but smoking and hypertension were slightly more prevalent. Overall, men with electrocardiographic abnormalities had higher risk factor levels than those with a normal electrocardiogram regardless of ethnic origin.

CONCLUSIONS

The prevalence of coronary heart disease and associated risk factors was different among Chinese living in two different environments: in Beijing in the People's Republic of China and in Mauritius. Chinese, who traditionally have a very low frequency of coronary heart disease, are by no means protected against coronary heart disease and other non-communicable diseases. Therefore, primary prevention of coronary heart disease is a major challenge for preventive medicine in China, as well as in many other developing countries.

Site-directed conversion of a cysteine to aspartate leads to the assembly of a [3Fe-4S] cluster in PsaC of photosystem I. The photoreduction of FA is independent of FB

The terminal electron acceptors FA and FB exist as two [4Fe-4S] clusters located on the 8.9-kDa PsaC protein in photosystem I. We have used site-directed mutagenesis to produce a complementary pair of mutant PsaC proteins in which specific cysteine ligands to the [4Fe-4S] clusters were changed to aspartic acid residues. The mutant proteins, denoted C14D and C51D, were overproduced in Escherichia coli; the iron-sulfur clusters were inserted in vitro; and the reconstituted proteins were rebound to the P700-FX core of Synechococcus sp. PCC 6301 in the presence of the PsaD protein. In complexes reconstituted with C51D a rhombic ESR spectrum with g-values of 2.063, 1.934, and 1.879 in the reduced state identifies the intact [4Fe-4S] cluster as FB, while an intense axial spectrum with g-values of 2.020 and 1.997 in the oxidized state identifies the altered cluster in the aspartate site as a [3Fe-4S] cluster. The [3Fe-4S] cluster corresponding to FA can be reduced chemically with dithionite and photochemically by illumination at room temperature but is not reduced by illumination at 15 K. With reconstituted C14D a rhombic ESR spectrum with g-values of 2.043, 1.942, and 1.853 in the reduced state identified the unaltered [4Fe-4S] cluster as FA, while a complex spectrum with a gz-value of 2.194 and an asymmetric gx,y set of resonances between 2.092 and 1.999 indicates an altered cluster of unknown identity in the site containing the aspartate ligand. The ESR signals arising from the altered cluster corresponding to FB are not diminished by illumination at either room temperature or 15 K.(ABSTRACT TRUNCATED AT 250 WORDS)

[Metastatic tumor of posterior fossa]

Twenty-seven cases of metastatic tumor of posterior fossa were presented in this paper. Of the patients, 20 were males and 7 females; their age ranged from 20 to 68, and 89% of them were over 40 years of age. The primary foci found were bronchopulmonary carcinomas (7 cases), rhinopharyngeal carcinomas (3 cases), and cancer of the liver (1 case), but in 16 cases the primary foci were not found. All of these patients presented symptoms and signs of obviously increased intracranial pressure, and most of them had the signs of cerebellar and cranial nerves' lesions. Ventriculorgraphy and brain CT scanning were important procedures in the diagnosis, and MRI was most valuable in establishing the diagnosis and localization of posterior fossa metastatic tumors. Twenty-six patients underwent operation. The short-term follow-up study showed an improvement in 25 cases. There was one death. The surgical treatment of posterior fossa metastatic tumor was emphasized. Radiotherapy and chemotherapy were discussed.

Structure and organization of rhodophyte and chromophyte plastid genomes: implications for the ancestry of plastids

Plastid genomes of two rhodophytes (Porphyra yezoensis and Griffithsia pacifica) and two chromophytes (Olisthodiscus luteus and Ochromonas danica) were compared with one another and with green plants in terms of overall structure, gene complement and organization. The rhodophyte genomes are moderately colinear in terms of gene organization, and are distinguished by three rearrangements that can most simply be explained by transpositions and a large (approximately 40 kb) inversion. Porphyra contains two loci for ppcBA and Griffithsia has two loci for rpoA. Although there is little similarity in gene organization between the rhodophytes and consensus green plant genome, certain gene clusters found in green plants appear to be conserved in the rhodophytes. The chromophytes Olisthodiscus and Ochromonas contain relatively large plastid inverted repeats that encode several photosynthetic genes in addition to the rRNA genes. With the exception of rbcS, the plastid gene complement in Olisthodiscus is similar to that of green plants, at least for the subset of genes tested. The Ochromonas genome, in contrast, appears unusual in that several of the green plant gene probes hybridizing to Olisthodiscus DNA did not detect similar sequences in Ochromonas DNA. Gene organization within the chromophytes is scrambled relative to each other and to green plants, despite the presence of putatively stabilizing inverted repeats. However, some gene clusters conserved in green plants and rhodophytes are also present in the chromophytes. Comparison of the entire rhodophyte, chromophyte and green plant plastid genomes suggests that despite differences in gene organization, there remain overall similarities in architecture, gene content, and gene sequences among in three lineages. These similarities are discussed with reference to the ancestry of the different plastid types.

Accumulation of wound-inducible ACC synthase transcript in tomato fruit is inhibited by salicylic acid and polyamines

Regulation of wound-inducible 1-aminocyclopropane-1-carboxylic acid (ACC) synthase expression was studied in tomato fruit (Lycopersicon esculentum cv. Pik-Red). A 70 base oligonucleotide probe homologous to published ACC synthase cDNA sequences was successfully used to identify and analyze regulation of a wound-inducible transcript. The 1.8 kb ACC synthase transcript increased upon wounding the fruit as well as during fruit ripening. Salicylic acid, an inhibitor of wound-responsive genes in tomato, inhibited the wound-induced accumulation of the ACC synthase transcript. Further, polyamines (putrescine, spermidine and spermine) that have anti-senescence properties and have been shown to inhibit the development of ACC synthase activity, inhibited the accumulation of the wound-inducible ACC synthase transcript. The inhibition by spermine was greater than that caused by putrescine or spermidine. The transcript level of a wound-repressible glycine-rich protein gene and that of the constitutively expressed rRNA were not affected as markedly by either salicylic acid or polyamines. These data suggest that salicylic acid and polyamines may specifically regulate ethylene biosynthesis at the level of ACC synthase transcript accumulation.

SH2 domains prevent tyrosine dephosphorylation of the EGF receptor: identification of Tyr992 as the high-affinity binding site for SH2 domains of phospholipase C gamma

Several cytoplasmic tyrosine kinases contain a conserved, non-catalytic stretch of approximately 100 amino acids called the src homology 2 (SH2) domain, and a region of approximately 50 amino acids called the SH3 domain. SH2/SH3 domains are also found in several other proteins, including phospholipase C-gamma (PLC gamma). Recent studies indicate that SH2 domains promote association between autophosphorylated growth factor receptors such as the epidermal growth factor (EGF) receptor and signal transducing molecules such as PLC gamma. Because SH2 domains bind specifically to protein sequences containing phosphotyrosine, we examined their capacity to prevent tyrosine dephosphorylation of the EGF and other receptors with tyrosine kinase activity. For this purpose, various SH2/SH3 constructs of PLC gamma were expressed in Escherichia coli as glutathione-S-transferase fusion proteins. Our results show that purified SH2 domains of PLC gamma are able to prevent tyrosine dephosphorylation of the EGF receptor and other receptors with tyrosine activity. The inhibition of tyrosine dephosphorylation paralleled the capacity of various SH2-containing constructs to bind to the EGF receptor, suggesting that the tyrosine phosphatase and the SH2 domain compete for the same tyrosine phosphorylation sites in the carboxy-terminal tail of the EGF receptor. Analysis of the phosphorylation sites protected from dephosphorylation by PLC gamma-SH2 revealed substantial inhibition of dephosphorylation of Tyr992 at 1 microM SH2. This indicates that Tyr992 and its flanking sequence is the high-affinity binding site for SH2 domains of PLC gamma.(ABSTRACT TRUNCATED AT 250 WORDS)

Functional expression of transcobalamin II cDNA in Xenopus laevis oocytes

The products of in vitro transcription of human transcobalamin II (TC II) cDNA when microinjected into Xenopus laevis oocytes yielded a single secretory protein of 43 kDa. The mobility of the 43 kDa band did not change following digestion with peptide N-glycosidase F. [57Co]Cbl bound to the medium was immunoprecipitated with anti-serum to human TC II, but not to other Cbl binders. In addition, the [57Co]Cbl complex also bound to placental microsomes. These results suggest that TC II mRNA transcribed encodes TC II which contains both the Cbl and receptor binding domains. Furthermore, Xenopus oocytes can be used as a screening system to define structural elements important in TC II's secretion and binding reactions.

Molecular cloning of the ViaB region of Salmonella typhi

The ViaB region required for Vi antigen production in Salmonella typhi was cloned. The plasmid pGBM124 containing a 14-kb S. typhi chromosomal DNA fragment conferred the ability to produce Vi antigen on Escherichia coli HB101 and ViaB-deleted S. typhi GIFU10007-3. Tn5 insertion analysis showed that the 14-kb DNA was split into three regions. Region 1 and region 2 are involved in the biosynthesis of Vi polysaccharide. Region 3 is involved in translocation of the Vi polysaccharide to the cell surface. Southern blot hybridization showed that regions 2 and 3 but not region 1, were considerably homologous to the DNA of Vi-positive Citrobacter freundii.

[Enteral nutrition support in severe surgical patients]

Enteral nutrition (EN) support was used in 88 patients with severe abdominal diseases, each with 2 to 7 (mean 3.8) surgical complications. Hospitalization ranged from 43 to 760 days (mean 122 days), during which the patients underwent 2 to 8 surgeries (mean 3.4). EN lasted for 9 to 409 days (mean 57.4 days), including TEN in 47 patients, TPN+EN in 12, and TEN transferring from TPN in 29, respectively. Patients' body weight, plasma proteins, and serum transferrin increased significantly by the end of EN support with the improvement starting from the second week. We conclude that EN should be used first in indicated patients.

[A comparative study of Bacteroides fragilis and E. coli related to the pathogenesis of calcium bilirubinate gallstones]

A comparative study of Bacteroides fragilis and E. coli bacterial infection in the biliary tract in relation to the pathogenesis of pigment stone formation was carried out on the basis of gallstone rabbit's model of anaerobic bacterial infection. One hundred and twenty Japanese hybrid big-ear white rabbits were randomly divided into four groups: 14 in control group, 31 in B. fragilis (BF) group, 42 in E. coli group and 33 in the mixed group. In the experimental groups we successfully made gallstone formation in aerobic, anaerobic and mixed bacterial infections in biliary tracts respectively. On 7, 15 and 30 postoperative days the survival rabbits were sacrificed for investigations. Our experiments demonstrated that the incidence and amount of stone formation in the mixed group were the highest among the experiment groups. The key point to preclude stone formation was to control the bacterial infection in the biliary tract as early as possible. The results suggested that the ability of production of beta-glucuronidase in BF group was significantly higher than that in E. coli group. The author considered that BF was more important than E. coli in the pathogenesis of calcium bilirubinate gallstone formation.

Polypeptide composition of the Photosystem I complex and the Photosystem I core protein from Synechococcus sp. PCC 6301

The polypeptide composition of the Photosystem I complex from Synechococcus sp. PCC 6301 was determined by sodium-dodecyl sulfate polyacrylamide gel electrophoresis and N-terminal amino acid sequencing. The PsaA, PsaB, PsaC, PsaD, PsaE, PsaF, PsaK and PsaL proteins, as well as three polypeptides with apparent masses less than 8 kDa and small amounts of the 12.6 kDa GlnB (PII) protein, wee present in the Photosystem I complex. No proteins homologous to the PsaG and PsaH subunits of eukaryotic Photosystem I complexes were detected. When the Photosystem I complex was treated with 6.8 M urea and ultrafiltered using a 100 kDa cutoff membrane, the resulting Photosystem I core protein was found to be depleted of the PsaC, PsaD and PsaE proteins. The filtrate contained the missing proteins, along with five proteolytically-cleaved polypeptides with apparent masses of less than 16 kDa and with N-termini identical to that of the PsaD protein. The PsaF and PsaL proteins, along with the three less than 8 kDa polypeptides, were not released from the Photosystem I complex to any significant extent, but low-abundance polypeptides with N-termini identical to those of PsaF and PsaL were found in the filtrate with apparent masses slightly smaller than those found in the native Photosystem I complex. When the filtrate was incubated with FeCl3, Na2S and beta-mercaptoethanol in the presence of the isolated Photosystem I core protein, the PsaC, PsaD and PsaE proteins were rebound to reconstitute a Photosystem I complex functional in light-induced electron flow from P700 to FA/FB. In the absence of the iron-sulfur reconstitution agents, there was little rebinding of the PsaC, psaD or PsaE proteins to the Photosystem I core protein. No binding of the truncated PsaD polypeptides occurred, either in the presence or absence of the iron-sulfur reagents. The reconstitution of the FA/FB iron-sulfur clusters thus appears to be a necessary precondition for rebinding of the PsaC, psaD and psaE proteins to the Photosystem I core protein.

PsaD is required for the stable binding of PsaC to the photosystem I core protein of Synechococcus sp. PCC 6301

The psaC gene product from Synechococcus sp. PCC 7002 and the psaD gene product from Nostoc sp. PCC 8009 were synthesized in Escherichia coli and purified to homogeneity. Incubation of the PsaC apoprotein with the Synechoccus sp. PCC 6301 photosystem I core protein in the presence of FeCl3, Na2S, and beta-mercaptoethanol resulted in a time-dependent transition in the flash-induced absorption change from a 1.2-ms, P700+ FX- back-reaction to a long-lived, P700+ [FA/FB]- back-reaction. ESR studies showed that FB and FA were photoreduced about equally at 19 K, and while the resonances were shifted upfield, they remained as broad as in the free PsaC holoprotein. When the reconstituted complex was purified in a sucrose gradient containing 0.1% Triton X-100, most of the optical absorption transient reverted to that characteristic of the P700+ FX- back-reaction. Addition of purified PsaD to the incubation mixture led to a greater extent of recovery of electron flow to FA/FB for any given concentration of PsaC. ESR studies showed that FA, rather than FB, became the preferred electron acceptor at 19 K; moreover, the resonances moved upfield and sharpened to become nearly identical with those of a control photosystem I complex. When the sample was purified in a sucrose gradient containing 0.1% Triton X-100, the long-lived P700+ [FA/FB]- optical transient remained stable. Analysis by denaturing polyacrylamide gel electrophoresis showed that the PsaC and PsaD proteins had rebound to the photosystem I core. The data indicate that although PsaC can bind loosely, the presence of PsaD leads to a stable, isolatable photosystem I complex which is spectroscopically indistinguishable from the native complex. Since a PsaC1 fusion protein which contains an amino-terminal extension of five amino acids (MEHSM...) does not bind in the absence of PsaD [Zhao, J., et al. (1990) FEBS Lett. 276, 175-180], the N-terminus of the PsaC protein could provide a site of interaction with the photosystem I core. We propose that the binding of PsaC to the PsaA/PsaB heterodimer is potentiated by insertion of the FA/FB clusters into PsaC, and stabilized by the presence of PsaD.

[Quantitation of platelet-bound von Willebrand factor in normal subjects and patients with coronary heart disease]

By using anti-human von Willebrand factor (vWF) monoclonal antibody, SZ-29, and indirect immunofluorescent technique and spectrofluorophotometer, we have quantitated platelet-bound vWF in normal subjects and patients with coronary heart disease (CHD). The results demonstrated that the quantity of platelet-bound vWF in CHD patients was significantly higher than that in normal (P less than 0.01) and the percentage of naturally activated platelet in CHD patients was also significantly higher than that in normal subjects (P less than 0.01). This might be one of the causes of hypercoagulability in CHD patients.