Assessment of two methods for rapid intrapartum detection of vaginal group B streptococcal colonisation.

AIMS--To compare two methods for the rapid detection of intrapartum vaginal carriage of group B streptococci (Streptococcus agalactiae) with standard culture techniques and to establish their suitability for routine use. METHODS--Vaginal swabs from 266 patients in labour were incubated in glucose broth in an anaerobic atmosphere for four to six hours. The Wellcogen Strep B latex particle agglutination test kit was subsequently used for antigen detection. In the second part of the study swabs from 117 women were assessed for the presence of group B streptococci using the ICON STREP B immuno-concentration assay (Hybritech). Both methods were compared with standard semiquantitative culture on Columbia horse blood agar and Islam's medium. RESULTS--In the first study vaginal carriage of group B streptococci was shown in 38 of 266 (14.3%) patients by culture. Latex particle agglutination with the Wellcogen kit detected 30 of these positive results (sensitivity 78.9%, specificity 100%). In those patients with moderate to heavy colonisation (> 10(4) colony forming units per millilitre) antigen was detected in all (26/26) culture positive patients (sensitivity 100%, specificity 100%). In the second study 16 (13.7%) patients were culture positive. The ICON test detected 11 positive results (sensitivity 68.8%, specificity 100%) and for heavy colonisation (10(5) cfu/ml) detected nine of nine cases (sensitivity 100%, specificity 100%). The ICON test took 10 to 15 minutes to perform. CONCLUSION--These tests are potentially useful for the rapid detection of group B streptococci vaginal colonisation in labour, particularly heavy colonisation. Both tests are insufficiently sensitive to replace standard culture methods.     

Normal or early development of puberty despite gonadal damage in children treated for acute lymphoblastic leukemia

To determine the timing of pubertal development and the frequency of gonadal dysfunction in children who survive acute lymphoblastic leukemia, we assessed pubertal status and the plasma levels of sex steroids, gonadotropin, and inhibin in 45 children (20 girls and 25 boys) who had received combination chemotherapy along with 24 Gy of irradiation to the cranium (modified LSA2L2 protocol). We also reexamined testicular biopsy specimens, obtained at the time of the cessation of chemotherapy, for the presence of germ cells. Germ-cell damage, indicated by marked elevations in the plasma level of follicle-stimulating hormone (P less than 0.001 for the comparison with normal children), was evident in both sexes and was confirmed in the boys by the absence of germ cells in the testicular biopsy specimens and by the small size of the testes for pubic-hair stage. Only 44 percent of the pubertal girls had measurable plasma inhibin levels, as compared with more than 93 percent of normal pubertal girls. Although plasma sex-steroid levels were normal, the secretion of luteinizing hormone in response to stimulation with gonadotropin-releasing hormone was elevated in the pubertal children (P less than 0.01 for the comparison with normal controls)--a finding that suggests compensation for decreased gonadal function. Despite clear evidence of gonadal damage, girls had early menarche at a mean age (+/- SD) of 11.95 +/- 0.91 years, as compared with the Australian standard of 12.98 +/- 1.11 years (P less than 0.01). Thus, in girls, puberty was early despite primary gonadal damage. Thirteen of 23 boys reached puberty at a mean age of 12.36 +/- 0.73 years. We conclude that treatment for acute lymphoblastic leukemia may lead to primary gonadal damage in both sexes, regardless of the age at treatment, but that the secondary characteristics of puberty develop at a normal age or, in girls, relatively early.     

Histometry of lymphoid infiltrate in the thyroid of primary thyrotoxicosis patients. Relation of extent of thyroiditis to preoperative drug treatment and postoperative hypothyroidism.

The thyroids of primary thyrotoxicosis patients prepared for partial thyroidectomy with propranolol contained much more lymphoid infiltrate than those prepared with carbimazole. No relation was found between the extent of lymphoid infiltrate in the thyroid and the development of postoperative hypothyroidism either between or within the two drug treatment groups. This study has shown that the extent of thyroid infiltrate should not be used as the major factor in predicting hypothyroidism after subtotal thyroidectomy for primary thyrotoxicosis.     

Adherence of slime-producing strains of Staphylococcus epidermidis to smooth surfaces.

Slime production is not a generally recognized feature of Staphylococcus epidermidis. In a recent outbreak of S. epidermidis intravascular catheter-associated sepsis, we noted that 63% of clinically implicated strains grew as a slimy film coating the culture tube walls when propagated in tryptic soy broth. Only 37% of randomly collected blood culture contaminants and skin isolates demonstrated a similar phenomenon (p less than 0.05). Transmission electron micrographs of these coating bacteria showed them to be encased in an extracellular matrix that stained with alcian blue. Slime production was most evident in autoclaved media containing Casamino Acids and glucose supplementation (0.25% wt/vol). There were strain and media preparation variability of slime production in the presence of other carbohydrates. Some strains were not able to produce slime under any of the tested conditions. The production or nonproduction of slime did not influence growth rate. When grown in vitro, slime producers accumulated on the surface of intravascular catheters as macrocolonies, whereas non-slime, producers did not. Transmission and scanning electron micrographs showed slime producers to be encased in an adhesive layer on the catheter surface, whereas nonproducers were not encased. These results suggest that slime-mediated adherence may be a critical factor in the pathogenesis of S. epidermidis infections of medical devices.     

Observer variability in the histopathological reporting of abnormal rectal biopsy specimens.

AIMS--To study the consistency of reporting of abnormal rectal biopsy specimens, especially in the differentiation of inflammatory bowel disease from other causes of abnormality. METHODS--Sixty rectal biopsy specimens were identified from patients presenting with bloody diarrhoea. These were then circulated to the 11 consultant pathologists in the study who filled in a proforma with a list of 12 diagnostic categories and 22 features. RESULTS--Forty one of the 60 cases were examples of inflammatory bowel disease. In 33 of these cases nine or more pathologists had made the diagnosis. Further categorisation into ulcerative colitis and Crohn''s disease showed better recognition of ulcerative colitis. In the 19 cases of non-inflammatory bowel disease recognition of pseudomembranous colitis and solitary rectal ulcer syndrome was good, but the results were poorer in the case of infective colitis. CONCLUSION--The findings suggest that a group of consultant pathologists can differentiate between inflammatory bowel disease and other causes of an abnormal rectal biopsy specimen and can also recognise pseudomembranous colitis and solitary rectal ulcer syndrome satisfactorily.     

Evaluation of an educational programme to improve the recognition of psychological illness by general practitioners.

BACKGROUND: Take Care is a commercially sponsored educational package for the detection and management of depression by all members of the primary health-care team. AIM: This study was designed to evaluate whether the educational package affects the recognition of psychological illness by general practitioners. METHOD: General practitioners working in 13 practices in North West England or Trent Regional Health Authorities took part the evaluation. Patients who scored more than eight on the depression or anxiety component of the Hospital Anxiety and Depression (HAD) scales, and who were thought by their general practitioner to have a totally physical problem or no illness, were deemed to have a psychological illness that had been 'missed' by the doctor. Changes in the proportion of missed cases before and after exposure to Take Care were estimated. RESULTS: When all practices were considered together, the general practitioners missed a depressive illness in 24.1% of patients before Take Care, and 17.1% afterwards; absolute decrease 7.0% [95% confidence interval (CI) -2.0 to -12.0%]. An improvement was seen in most practices (Wilcoxon matched-pair test P < 0.05). The programme was also associated with a small reduction in the overall proportion of episodes of anxiety missed by the doctor (absolute decrease 4.5%; 95% CI -1.0 to -8.0%) a reduction was found in most practices (Wilcoxon matched-pair test P < 0.05). There was no material difference in the diagnostic false-positive rate of the doctors before and after the introduction of the programme. CONCLUSION: Exposure to an educational package for depression was associated with improved recognition of psychological illness by general practitioners.     

Differential expression of complement regulatory proteins decay-accelerating factor (CD55), membrane cofactor protein (CD46) and CD59 during human spermatogenesis.

We have examined the distribution of the complement (C) regulatory proteins CD59, membrane cofactor protein (MCP) and decay-accelerating factor (DAF) on mature sperm and compared expression of these proteins in parallel both during spermatogenesis and in the prostate. Enhanced immunoperoxidase staining and radioimmunoassay confirmed that C regulators are differentially expressed on sperm; CD59 was strongly expressed on the surface of acrosome intact sperm while MCP and DAF appear to be located primarily on the inner acrosomal membrane. While the MW of CD59 on sperm is typical of other systems, we confirm that in addition to a novel 40,000-46,000 MW MCP protein, sperm also express a novel 55,000 MW DAF product. Examination of normal testis by immunostaining revealed that although C regulators are differentially expressed within the germinal epithelium, all three proteins were present on the acrosomal region of condensing spermatids. We show that novel, low MW forms of MCP and DAF are expressed in normal testis membranes but are absent from testis membranes obtained from patients undergoing gender reassignment surgery in whom the germinal epithelium is diminished. Novel MW C3 convertase regulators are therefore associated with differentiating germinal epithelium. Typical CD59 components were also present on normal testis membranes confirming that CD59 is acquired during spermatogenesis. We demonstrate that the prostatic epithelium, in addition to MCP, expresses CD59 but not DAF. By comparison with CD59, therefore, our studies suggest that DAF may be acquired only in the testis. Overall, our data suggest that, on leaving the testis, sperm express the repertoire of C regulators required for protection from C during their transit through the male and female reproductive tracts.     

Mcm1 regulates donor preference controlled by the recombination enhancer in Saccharomyces mating-type switching

Switching of Saccharomyces mating type by replacement of sequences at the MAT locus involves a choice between two donors, HML and HMR. MATα cells inhibit recombination along the entire left arm of chromosome III, including HML, whereas MATa cells activate this same region. MATa-dependent activation of HML depends on a small, cis-acting DNA sequence designated the recombination enhancer (RE), located 17 kb centromere-proximal to HML. A comparison of RE sequences interchangeable between Saccharomyces cerevisiae and Saccharomyces carlsbergensis defines a minimum RE of 244 bp. RE activity is repressed in MATα cells by binding of the Matα2–Mcm1 corepressor to a site within the RE. Mutation of the two Matα2 binding sites removes most, but not all, of this repression, and RE chromatin structure in MATα cells becomes indistinguishable from that seen in MATa. Surprisingly, a 2-bp mutation in the Mcm1 binding site completely abolishes RE activity in MATa cells; moreover, RE chromatin structure in the MATa mutant becomes very similar to that seen in MATα cells with a normal RE, displaying highly ordered nucleosomes despite the absence of Matα2. Further, a mutation that alters the ability of Mcm1 to act with Matα2 in repressing a-specific genes also alters donor preference in either mating type. Thus, Mcm1 is critically responsible for the activation as well as the Matα2-Mcm1-mediated repression of RE activity.     

Production by Clostridium spiroforme of an iotalike toxin that possesses mono(ADP-ribosyl)transferase activity: identification of a novel class of ADP-ribosyltransferases

Clostridium spiroforme iotalike toxin produced time- and concentration-dependent incorporation of ADP-ribose into homo-poly-L-arginine. Polyasparagine, polyglutamic acid, polylysine, and agmatine were poor substrates. Enzyme activity was associated with the light-chain polypeptide of the toxin. The heavy chain did not possess ADP-ribosyltransferase activity, nor did it enhance or inhibit activity of the light chain. In broken-cell assays, the toxin acted mainly on G-actin, rather than F-actin. A single ADP-ribose group was transferred to each substrate molecule (G-actin). The enzyme was heat sensitive, had a pH optimum in the range of 7 to 8, was inhibited by high concentrations of nicotinamide, and was reversibly denatured by urea and guanidine. Physiological levels of nucleotides (AMP, ADP, ATP, and ADP-ribose) and cations (Na+, K+, Ca2+, and Mg2+) were not very active as enzyme inhibitors. The toxin was structurally and functionally similar to Clostridium botulinum type C2 toxin and Clostridium perfringens iota toxin. When combined with previous findings, the data suggest that a new class of mono(ADP-ribosyl)ating toxins has been found and that these agents belong to a related and possibly homologous series of binary toxins.