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Biomedical subjects

S R Wilson

Publications and source records attributed to S R Wilson.

At least 181 records · Page 10Linked to original sources
PubMed1981

Type III group B streptococcal strain differences in susceptibility to opsonization with human serum.

Human serum opsonins to type III Group B streptococci (GBS) were studied in an in vitro opsonophagocytic assay. Two type III GBS test strains were susceptible (893 and IIINor) and two resistant (891 and 892) to opsonization by the majority of sera from 15 healthy adults. Four individuals with undetectable or low opsonic titers to the test strains were immunized with pneumococcal vaccine; immunization with pneumococcal vaccine induced a titer rise in all but one instance when susceptible GBS strains were tested. In contrast, only a single titer rise was detected when resistant GBS strains were employed in the test. These results indicate that immunization with a cross-reacting antigen (identical to core antigen of type III GBS) fails to induce opsonic antibody to all strains of type III GBS. A resistant strain was made highly susceptible to neutrophil killing in vitro by exposure to neuramindase prior to incubation with opsonic serum. Using a fluorescent lectin-binding assay, this enzyme appeared to remove surface sialic acid, suggesting that sialic acid is an antiphagocytic factor. However, the possibility that other surface moieties may act as antiphagocytic factors cannot be ruled out. Both opsonic susceptible and resistant strains absorbed opsonic antibody from serum, which suggests that the GBS antiphagocytic factors do not prevent binding of antibody to resistant bacteria. These findings indicate that demonstration of serum opsonic activity to one strain of type III GBS may not accurately depict opsonic activity to other strains. In addition, immunization with core antigen did not enhance opsonic activity against all GBS strains. These data also point out the need to use assays which measure functional antibody, since demonstration of antibody binding may not reflect its ability to facilitate bacterial phagocytosis and killing.

Adult↗
PubMed1980

Diminished bacterial defences with intralipid.

'Intralipid', a lipid emulsion used in parenteral nutrition, impaired bacterial clearance and enhanced bacterial virulence in mice. In addition it inhibited the chemotaxis of human neutrophils in vitro. Intralipid may enhance the risk of bacterial sepsis in certain patients.

Animals↗
PubMed1980

Analyzing gene-frequency data when the effective population size is finite.

The statistical methods used by SCHAFFER, YARDLEY and ANDERSON (1977) and by GIBSON et al. (1979) to analyze the variation in allele frequencies in two common types of experimental procedure, where the effective population size is finite, are extended to a more general situation involving a greater range of experiments. The analysis developed is more sensitive in detecting changes in allele frequency due to both fluctuating and balancing selection, as well as to directional selection. The error involved in many studies due to ignoring the effective population size structure would appear to be large. The range of hypothesis that can be considered may be increased as well. Finally, the method of determining bounds for the effective population size, when a particular genetic model is known to hold for a data set, is also outlined.

Alleles↗
PubMed1980

The role of computed tomography in assessment of tumoral pathology of the adrenal glands.

The findings at computed tomography (CT) of the adrenal glands in 58 patients are presented. Most patients (50) were referred for suspected adrenal dysfunction. In three, adrenal masses were suspected from other radiological studies. Three patients had palpable abdominal masses, and incidental adrenal metastases were found in two. Pathological findings included pheochromocytomas (nine patients), adrenocortical adenomas (six), adrenocortical carcinomas (three), metastases (two), and one example each of myelolipoma, hemorrhagic renal cyst, and probable granuloma. Of 24 adrenal masses, 23 were clearly apparent in the scans and one was suspected. The smallest tumor diagnosed was 0.5 cm in diameter. There was on false positive diagnosis of a small tumor and no known false negatives. Because of their consistent location and unusual shape and because they are usually surrounded by retroperitoneal fat, the adrenal glands are ideal organs for study by CT, a highly accurate method for detecting and excluding mass lesions that may render arteriography and venography unnecessary. Surgery was performed in five patients with tumors following localization by CT only. Limitations and potential diagnostic pitfalls in interpretation are discussed.

Adolescent↗
PubMed1980

Varices of the gallbladder.

Fixed filling defects of the gallbladder on an oral cholecystogram were demonstrated by ultrasound and a splenoportogram to represent gallbladder varices. No previous ultrasound description of gallbladder varices could be found in the literature.

Cholecystography↗
PubMed1979

Immunoprecipitation and opsonic cross-reaction between type-14 pneumococcus and group-B streptococcus type III.

Antisera directed against type-14 pneumococcus was opsonic for several strains of type-III group-B streptococcus. Furthermore, the polysaccharide antigen in the polyvalent pneumococcal vaccine reacted to form precipitation lines with antisera directed against type-14 pneumococcus and group-B streptococcus type III Immunisation with currently available pneumococcal vaccine may provide opsonic antibody against group-B streptococci and provide a method of preventing neonatal group-B streptococcal infections.

Animals↗
PubMed1979

Selection for ethanol tolerance in two populations of Drosophila melanogaster segregating alcohol dehydrogenase allozymes.

Selection for ethanol tolerance was equally successful in two populations of D. melanogaster in both of which the frequency of AdhF was 0.5 at the start of the experiment. Increased tolerance to ethanol was not invariably associated with increased frequencies of AdhF. In one population alcohol dehydrogenase (ADH) activity was significantly higher in three of the four selected sublines compared with their controls but there was no difference in activity between the selected and control sublines in the second population. The level of ADH activity in the control and selected lines was significantly correlated with the frequency of AdhF, but not with ethanol tolerance. These results show that adaptation to environmental alcohols in populations of D. melanogaster can be independent of the ADH system.

Alcohol Oxidoreductases↗
PubMed1979

On the use of multiple thresholds for the determination of the mode of inheritance of semi-continuous traits.

In this article we reconsider the analysis proposed by Reich et al. (1972) for determining the mode of inheritance for semi-continuous traits from intrafamilial data. We consider both the (general) multifactorial and the single-locus model formulation. We show (numerically), by using a much improved numerical analysis technique for the parameter estimation, that there may be many single-locus models that could have given rise to a particular data set, dependent on its size and nature. Finally we question whether the use of monozygotic twins data, or data obtained from defining further levels of severity of the disease, would improve the discrimination between these two types of models.

Alleles↗
PubMed1979

Abdominal biopsy with ultrasound guidance.

The value of aspiration biopsy under ultrasound guidance has been demonstrated in 51 patients. The confirmation of malignancy, particularly, has allowed many patients the value of chemotherapy or a quiet demise, without the necessity for diagnostic laparotomy.

Abdominal Neoplasms↗