Role of inflammatory mediators in resistance and susceptibility to pneumococcal infection

Variations in the host response during pneumonia caused by Streptococcus pneumoniae in susceptible (CBA/Ca) and resistant (BALB/c) inbred mouse strains were investigated. Significant differences were detected in survival time, core body temperature, lung-associated and systemic bacterial loads, mast cell numbers, magnitude and location of cytokine production, lung disruption, and ability of isolated lung cells to release the cytokine tumor necrosis factor (TNF) alpha in vitro. Overall, the results indicate that the reduced capacity of CBA/Ca mice to induce rapid TNF activity within the airways following infection with S. pneumoniae may be a factor in their elevated susceptibility to pneumococcal pneumonia.     

Immunoglobulin light chain mRNA detected by in situ hybridisation in diagnostic fine needle aspiration cytology specimens.

AIMS: To demonstrate expression of immunoglobulin light chain mRNA in diagnostic fine needle aspiration (FNA) cytology specimens using an in situ hybridisation (ISH) technique; and to evaluate ISH in a series of reactive lymphoid proliferations and malignant lymphomas. METHODS: Forty diagnostic FNA specimens showing a lymphoid cell population were examined for immunoglobulin light chain mRNA expression using ISH. Aspirates were obtained from lymph node (n = 34), salivary gland (n = 3), subcutaneous tissue, thyroid and breast (n = 1 each). The cases included 20 B cell lymphomas, five cases of Hodgkin's disease and 15 reactive lymphoid proliferations. Comparison with light chain immunoreactivity was made in 36 cases and histological correlation from biopsy material was available in 24. RESULTS: Immunoglobulin light chain restriction was demonstrated in 14 of 20 B cell lymphomas using ISH and in six of 17 B cell lymphomas using immunocytochemistry. A polytypic pattern of light chain expression was observed in four of five cases of Hodgkin's disease with both techniques, and in 12 of 15 and 11 of 14 reactive lymphoid proliferations using ISH and immunocytochemistry, respectively. CONCLUSIONS: The assessment of immunoglobulin light chain expression is a useful adjunct to morphology in the diagnosis of reactive and malignant lymphoid proliferations in FNA specimens. Light chain restriction can be shown using either immunocytochemistry or ISH, but the latter is more sensitive in the diagnosis of B cell lymphoma.     

Non-specific X linked mental retardation.

Non-specific X linked mental retardation (MRX) is mental retardation in persons of normal physical appearance who have no recognisable features apart from a characteristic pedigree. Review of published reports shows that there is clinical variability in the degree of mental retardation within families and genetic heterogeneity, based on gene localisation, between families. We propose a classification based on genetic localisation and a set of minimal clinical features that should be recorded in the hope of identifying possible specific phenotypes.     

HBME-1 and antithrombomodulin in the differential diagnosis of malignant mesothelioma of pleura.

AIMS: To determine the usefulness of antibodies HBME-1 and antithrombomodulin in the differential diagnosis of malignant mesothelioma of the pleura. METHODS: Using microwave antigen retrieval and streptavidin-biotin complex horseradish peroxidase immunohistochemistry the above antibodies were used to stain sections of 57 malignant mesotheliomas, 17 reactive pleural hyperplasias, 23 cases of carcinoma metastatic in pleura, 20 primary ovarian cell carcinomas, and 20 primary renal cell carcinomas. RESULTS: Eighty six per cent of mesotheliomas and 82% of reactive mesothelial hyperplasias stained strongly with HBME-1. However, 48% of carcinomas metastatic to pleura also stained, as did all serous ovarian carcinomas. Seventy two per cent of mesotheliomas and 24% of reactive mesothelial hyperplasias stained strongly with the antithrombomodulin antibody; 86% and 88%, respectively, of these cases showed staining of any type. While 26% of metastatic carcinomas showed some staining with antithrombomodulin, only one third of these (9%) showed strong, yet focal, staining. Of 40 ovarian and renal carcinomas only two (5%) showed any staining with antithrombomodulin. CONCLUSIONS: HBME-1, although a sensitive mesothelial marker, is not sufficiently specific to be useful diagnostically, as almost half of carcinomas metastatic to pleura also stained positive. Antithrombomodulin is also a sensitive mesothelial marker and is sufficiently specific to be a useful discriminator, positively identifying, in appropriate circumstances, the mesothelial nature of a cell population.     

General practitioners and psychiatrists: comparison of attitudes to depression using the depression attitude questionnaire.

BACKGROUND. Variation in the management of depression may be linked to doctors' attitudes to depression. AIM. A study was undertaken comparing the attitudes to depression between general practitioners and psychiatrists. METHOD. A sample of 74 general practitioners and 65 psychiatrists in Wales was surveyed by postal questionnaire. Attitudes were assessed by the depression attitude questionnaire and patient management was assessed by a questionnaire on prescribing practice. RESULTS. General practitioners differed significantly from psychiatrists in attitudes, particularly in areas covering professional ease in dealing with patients with depression and identification of depression. Those general practitioners who reported use of low antidepressant doses were significantly more likely than general practitioners prescribing standard doses to believe in psychotherapeutic treatments. Users of short-term continuation therapy expressed a lack of therapeutic optimism and comfort in dealing with depressed patients. CONCLUSION. General practitioners and psychiatrists differ significantly in their attitudes to depression. The attitudes which vary among general practitioners reflect practice. The depression attitude questionnaire may prove useful in indicating how educational initiatives to improve primary care detection and management should be directed.     

Antidepressant prescribing: a comparison between general practitioners and psychiatrists.

BACKGROUND. The 'defeat depression' campaign emphasizes the importance of adequate prescribing of antidepressants in general practice. AIM. A study was undertaken to investigate the prescribing habits of a group of general practitioners and psychiatrists. METHOD. A postal questionnaire was sent to 123 general practitioners and 97 psychiatrists in south Wales. RESULTS. The response rate among general practitioners was 60% and among psychiatrists it was 67%. As a group, the psychiatrists reported using significantly higher daily dosages of antidepressant medication for adult and for elderly patients over a longer period compared with general practitioners. Fifty two per cent of 68 general practitioners and 17% of 60 psychiatrists reported using lower than recommended daily treatment dosages for adult patients and 40% of 68 general practitioners and 7% of 62 psychiatrists used a shorter than recommended period of continuation therapy (less than four months). Both groups showed a wide variation in the use of maintenance therapy. CONCLUSION. Educational efforts should be made to improve the prescribing habits of general practitioners and psychiatrists.     

Rapid Detection of Contagious Bovine Pleuropneumonia by a Mycoplasma mycoides subsp. mycoides SC Capsular Polysaccharide-Specific Antigen Detection Latex Agglutination Test

A latex agglutination test (LAT) has been developed for the diagnosis of contagious bovine pleuropneumonia (CBPP). The latex microspheres were coated with MmmSC polyclonal immunoglobulin G antiserum and detected MmmSC antigen in the serum of cattle infected with CBPP and in growth medium containing MmmSC. The specific antigen recognizsed by this test appeared to be the capsular polysaccharide (CPS). The LAT recognized all 23 strains of MmmSC examined in this study, with a sensitivity level of 2 ng of CPS, or the equivalent of 5 × 10³ CFU, in a reaction volume of 0.03 ml. Therefore, rapid identification of MmmSC cultures should be possible. Agglutination was also observed with the related goat pathogens and “Mycoplasma mycoides” cluster members Mycoplasma mycoides subsp. mycoides large colony biotype (four of six strains positive) and Mycoplasma mycoides subsp. capri (three of six strains positive), in agreement with the suggestion that these latter two mycoplasmas may in fact represent a single species (although collectively exhibiting two capsular serotypes). Comparisons in diagnosis with the complement fixation test (CFT) were made by using African field sera from CBPP-infected cattle. After 2 (or 3) min of incubation, the test detected 55% (or 61%) of CFT-positive sera and 29% (or 40%) of CFT-negative sera, with an overall correlation in diagnosis of 62% (or 61%). The rates for false-positive diagnoses made by using “known” CBPP-negative sera from the United Kingdom were 3 or 13% after 2 or 3 min of incubation, respectively. The data agree with previous findings that some CBPP CFT-negative misdiagnoses may occur due to “antibody eclipsing” by excess circulating antigen. The LAT combines low cost and high specificity with ease of application in the field, without the need for any specialist training or equipment.     

Immunoglobulin heavy chain switch region restriction fragment length polymorphisms are associated with renal disease.

We describe here, to our knowledge for the first time, associations between polymorphisms at the genomic DNA level in the immunoglobulin gene region and renal diseases which lead to chronic renal failure. Recent studies have shown that protein polymorphisms, present in immunoglobulin (Ig) heavy chains (Gm allotypes) are associated with certain forms of renal disease and with end stage renal failure per se. To investigate this association at the DNA level we have used probes which recognize Ig heavy chain genes and this report describes results obtained with one of these, the S mu switch region probe. With the restriction endonuclease Sst 1 (or the isoschizomer; Sac I) a number of restriction fragment length polymorphisms (RFLP) can be obtained which are recognized by this probe and there is a highly significant association between certain of these and renal disease. This is the first report of Ig switch region polymorphisms being associated with disease, yet our results suggest that S mu RFLP are more closely linked to renal disease than Ig protein polymorphisms.     

Isolation and characterization of human and rabbit sperm tail fibrous sheath

Using mechanical and chemical dissection methods, fibrous sheath was isolated both from normal ejaculated human spermatozoa and from rabbit cauda epididymal spermatozoa. The same techniques did not produce a pure preparation of fibrous sheath from ejaculated rabbit spermatozoa, suggesting that further cross-linking and stabilization of sperm structures occurs in response to components of the seminal plasma. The isolation procedures were monitored by phase contrast microscopy and the purity of the fibrous sheath was verified by electron microscopy. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of isolated human fibrous sheath revealed at least 14 protein bands of which the most intensely stained were of molecular weight 84, 72, 66.2, 57, 32 and 28.5 kDa. The rabbit fibrous sheath revealed at least 10 protein bands, of which the most intensely stained were 35.2, 32.7 and 28.5 kDa. The amino acid composition of the purified fibrous sheath from human and rabbit spermatozoa was similar, being high in aspartic acid and/or asparagine and glutamic acid and/or glutamine, serine, alanine, leucine, lysine and glycine, but low in histidine, tyrosine and isoleucine. This composition is similar to that reported for the rat and suggests that mammalian sperm tail fibrous sheaths are composed of similar types of proteins, although there are apparent differences in protein components between species.