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Biomedical subjects

S C Bell

Publications and source records attributed to S C Bell.

198 records · Page 11Linked to original sources
PubMed1969

Micromethod for assaying serum levels of erythromycin.

A micromethod for assaying serum levels of erythromycin is described. The assay had the following characteristics: detection of 0.03 to 0.035 mug/ml, a long-range curve which minimizes sample dilution, 0.04 ml for a single measurement (0.3 ml required for full coverage), and utility for a variety of body fluids. The method employs radial diffusion from small paper discs which were saturated by capillary action rather than by dipping or pipetting. Although the method was designed to handle serum in which the sample volume is limited, statistical analysis demonstrated that the method has satisfactory precision for routine use. A study of 10 consecutive assays indicates a precision of +/-12% at the 95% confidence limits. The method of least squares was used to calculate the line of best fit, and the statistics were developed on this basis. The assay method is applicable to a variety of antibiotics.

Anti-Bacterial Agents↗
PubMedDate not supplied

Antibodies to heat shock proteins in dogs with rheumatoid arthritis and systemic lupus erythematosus.

Antibodies to heat shock proteins of the 65 kDa group were demonstrated in canine sera and synovial fluid. This paper reports these antibody measurements in three groups of dogs with joint disease and compares them with those of a control population. Dogs with rheumatoid arthritis (RA) showed higher anti-heat shock proteins (HSP) antibody levels, in both their sera and synovial fluids, compared to the control dogs and these antibodies were predominantly of the IgG and IgM class; there was a significant correlation between IgM anti-HSP65 and IgM-rheumatoid factors. There was also a significant correlation between anti-HSP65 and antibodies to canine distemper virus, but only of the IgM class and the relevance of these antibodies to the overall pathogenesis of canine RA and, in particular, to the presence of canine distemper virus within the joint, are discussed.

Animals↗
PubMedDate not supplied

Analysis and significance of anti-nuclear antibodies in dogs.

Assays for detecting and measuring antinuclear antibodies (ANA) in dogs were compared. They included the indirect immunofluorescence test, using rat liver as substrate, and ELISAs for three nuclear antigens: double-stranded DNA, single-stranded DNA, and histone. There was no correlation between the ANA titre and antibodies to the three nuclear antigens. Analysis of ANA in different arthropathies showed no specific disease association. HEP-2 cells showed no fluorescence reaction with either ANA-positive or ANA-negative dog sera. Western blotting produced too complex a pattern to identify specific antigens. The antigens that reacted with ANA in dogs were not identified; there is either a broad range of reactivities or non-specific binding of immunoglobulins.

Animals↗
PubMedDate not supplied

Localization of antigen defined by a monoclonal antibody to human 32-kDa insulin-like growth factor-binding protein in the sheep uterus at preimplantation stages of pregnancy.

Employing a murine monoclonal antibody to pregnancy-associated endometrial alpha I-globulin, a 32-kDa insulin-like, growth factor-binding protein (IGF-BP) and major product of the decidualized endometrium in the human, reactivity has been detected in the luminal epithelium of the sheep endometrium during the preimplantation period of pregnancy. Staining was associated with supranuclear regions of the cytoplasm. Reactivity was restricted to the pregnant uterus and was distributed throughout the luminal epithelium in both caruncular and intercaruncular regions. The reactivity was absent from endometrial glands in intercaruncular regions. Staining was first detected at day 10, peaked at day 14 of gestation and was absent by day 16. The implications of the induction of the production of this protein by the preimplantation blastocyst in the luminal epithelium is discussed with reference to the potential role of IGF-BP in IGF action in the embryo.

Animals↗
PubMedDate not supplied

Confocal immunofluorescence localization of collagen types I, III, IV, V and VI and their ultrastructural organization in term human fetal membranes.

The distribution of collagen types I, III, IV, V and VI in term human fetal membranes was examined using conventional and confocal indirect immunofluorescence techniques. Collagens I and III were present in most of the layers of fetal membranes except in the trophoblast layer contrary to what has been previously reported. Although collagen IV is considered to be a basement membrane component our study, using monoclonal and polyclonal antibodies, showed its consistent presence in the spongy and reticular layers in high intensity. This was first report on the distribution of type V collagen in the chorion where it was found in the reticular and in the trophoblast layers. Type VI collagen was present mainly in the amnion and the reticular layer. The ultrastructural examination of the extracellular matrix showed that the main fibrous skeleton of the fetal membranes was formed of large banded fibres (Ultrastructurally identical to collagens types I and III) connected together and to the epithelial basement membranes by networks of unbanded filaments (collagen types V, VI and other components). The extensive and continuous networks formed by these collagens may be a major factor responsible for the mechanical integrity of the fetal membranes.

Collagen↗
PubMedDate not supplied

Ia antigen-bearing decidual cells and macrophages in cultures of mouse decidual tissue.

The ontogeny of Ia antigen expression on cells within the decidua basalis of the placenta and on decidual cells differentiating in vitro was investigated in the mouse. The results indicate that Ia antigen expression is temporarily restricted and can be detected in short-term cultures of decidual tissue only during the final third of gestation. The Ia antigen positive cells, which are non-phagocytic, non-specific esterase negative and lack Fc receptors, appear to be true decidual cells on the basis of their fine structural characteristics. In contrast, morphologically identical dendritic decidual cells arising from differentiation in vitro of endometrial cells do not express Ia antigens. A population of small rounded cells was also present in cultures of both decidual tissue and in vitro decidualized endometrial cells. These rounded cells possess the macrophage-like properties of Fc receptors, non-specific esterase and phagocytic activity. The possible function of these cell populations within the decidual tissue is discussed.

Animals↗
PubMedDate not supplied

Immunochemical and biochemical relationship between human pregnancy-associated secreted endometrial alpha 1- and alpha 2-globulins (alpha 1- and alpha 2-PEG) and the soluble placental proteins 12 and 14 (PP12 and PP14).

Two proteins, pregnancy-associated endometrial alpha 1- and alpha 2-globulins (alpha 1- and alpha 2-PEG), synthesized de novo and secreted by the human endometrium and decidua during pregnancy, have been demonstrated to be immunochemically related to the soluble placental proteins PP12 and PP14 isolated from term placenta. However, although these immunochemically similar endometrially- and placentally-derived proteins differ in their reported biochemical properties, in this report we have demonstrated that PP12 and PP14 are biochemically identical to alpha 1- and alpha 2-PEG with respect to subunit size. We conclude that these placental proteins are derived from the endometrium by de novo synthesis, and we suggest that the localization of these proteins to the placenta reflects either absorption, specific binding or processing by the trophoblast. The significance of clinical studies involving PP12 and PP14 measurement must therefore be reassessed in the light of their exclusive endometrial origin.

Abortion, Therapeutic↗
PubMedDate not supplied

Partial characterization of immunosuppressive factors from short-term cultures of murine decidual tissue.

Previous in vitro experiments provided evidence for the immunosuppressive properties of supernatants from short-term cultures of decidual tissue obtained from the uterus of the pregnant mouse. The inhibitory activity of supernatants, previously detected in a mixed lymphocyte reaction (MLR), has now been demonstrated in an in vitro thymocyte proliferation assay. Fractionation of these supernatants on Sephadex G-15 and Sephacryl S-300 revealed that inhibition of the thymocyte proliferation assay was associated only with a low molecular weight fraction (less than 1,500), whilst MLR inhibitory activity was associated with three different molecular weight fractions (less than 1,500, 60,000 and 1,000,000). These results are discussed in relation to the different biological factors previously isolated in decidua or deciduoma of rats and humans.

Animals↗
PubMedDate not supplied

Aminoglycosides in cystic fibrosis: a descriptive study of current practice in Australia.

AIM: To determine the diversity of clinical practice with respect to aminoglycosides in cystic fibrosis (CF) units within Australia. METHOD: In April 1999, a questionnaire on the use of aminoglycosides was sent to 30 CF units across Australia. Information was collected about drug selection, dosing, monitoring and toxicity with intravenous administration. RESULTS: Completed surveys were received from 26 of the 30 units (response rate = 86%) and all units with > 40 patients. Tobramycin was the drug of choice in all but two centres where there was equivalent use of gentamicin and tobramycin. The survey demonstrated a trend in recent years to reduce the number of doses per day with 54% of centres prescribing once daily, 23% twice daily and 23% thrice daily regimens. Initial dosing was generally based on mg/kg per day (mean 8.8, range 7.5-10 mg/kg per day). Dosing by infusion occurred in 11 of 14 units using once-daily dosing and there was equivalent use of bolus and infusion methods for multiple-daily regimens. Drug monitoring depended on dosing regimen. Units using multiple daily regimens monitored using trough +/- peak levels, whereas 50% of units using once-daily dosing used two postdose levels to alter dose. Actual toxicity, in particular nephrotoxicity, ototoxicity and vestibular toxicity was reported by 19, 27 and 12% of units, respectively. CONCLUSION: The prescribing, dosing and monitoring of aminoglycosides in CF across Australia varies greatly. This is likely to be due to a lack of definitive evidence as to the optimum use in this patient group.

Adolescent↗