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Biomedical subjects

B D Bennett

Publications and source records attributed to B D Bennett.

49 records · Page 3Linked to original sources
PubMed1988

Uses and limitations of prostate-specific antigen in the laboratory diagnosis of prostate cancer.

We have studied the clinical utility of a recently developed assay for a prostate specific protein (prostate-specific antigen). Histochemical demonstration of prostate-specific antigen has a higher sensitivity and specificity for the diagnosis of prostate carcinoma than does prostatic acid phosphatase. Similarly, measurement of prostate-specific antigen by immunoassay in serum is a more sensitive indicator of tumor stage and recurrence after therapy than prostatic acid phosphatase. More information is needed, however, regarding the variation in this protein with different therapeutic methods.

Acid Phosphatase↗
PubMed1987

Nucleotide sequence and deduced amino acid sequence of a coleopteran-active delta-endotoxin gene from Bacillus thuringiensis subsp. san diego.

A gene from Bacillus thuringiensis subsp. san diego that is responsible for a delta-endotoxin active against Colorado potato beetle and some other Coleoptera was sequenced and shown to have surprising regional homology with both lepidopteran and dipteran active delta-endotoxins from other strains of B. thuringiensis. Unlike the lepidopteran active toxins from B. thuringiensis subsp. kurstaki that exist as approx. 130-kDa protoxins and form bipyramidal crystalline inclusions, the coleopteran toxic protein forms a square-shaped crystal composed of an approx. 65-kDa protein. Comparisons of the gene sequences encoding the active portions of these protoxins indicate conservation of N-terminal hydrophilic and hydrophobic regions, and suggest a distant ancestral origin for these insecticidal proteins.

Amino Acid Sequence↗
PubMed1986

Trichomonas vaginalis in the prostate gland.

Although the prostate gland is believed to serve as a parasite reservoir in trichomoniasis in men, and clinical association of trichomonads with prostatitis is common, there has been, to our knowledge, no unequivocal demonstration of Trichomonas vaginalis within the prostate gland. Using established immunoperoxidase procedures, we have positively identified trichomonads in the prostatic urethra, glandular lumina, submucosa, and stroma. Foci of nonspecific acute and chronic inflammation, as well as intraepithelial vacuolization, were associated with the infection. The finding of trichomonads within and beneath glandular epithelium necessitates reevaluation of the traditional view of T vaginalis as a strictly surface-dwelling organism.

Humans↗
PubMed1986

Teaching laboratory medicine. The clinical laboratory experience.

A medical student's introduction to the clinical laboratory often sets the tone for the relationship that will exist between him or her and the laboratory throughout medical practice. As part of the sophomore pathology and laboratory medicine course at the University of South Alabama, Mobile, groups of seven or eight medical students spend one hour in each of ten different areas of the clinical laboratory. This experience acquaints the students with laboratory personnel, organization, and procedure, and emphasizes the importance of communication between clinicians and the laboratory staff. Consequently, our students have greater awareness of the capabilities and limitations of laboratory testing. This has, in turn, resulted in more efficient use of laboratory resources by clinicians and fewer complaints about laboratory service. The relatively small size of the classes in our institution enables us to schedule these sessions effectively. However, schools with larger classes could use a similar system since many of these schools have access to laboratories at more than one hospital.

Alabama↗
PubMed1983

Oral administration of nicotine: its uptake and distribution after chronic administration to mice.

An investigation was made of the suitability of administering nicotine to experimental animals by inclusion in the drinking water. It was found that, after an initial accommodation period of several weeks, nicotine could be administered up to a concentration of 100 micrograms/ml with no decrease in fluid intake or weight gain compared to control. An analysis of the steady-state plasma levels and distribution of nicotine was made in mice which had received nicotine in the drinking water at a concentration of 60 micrograms/ml. The average daily dose of nicotine received by these animals was 17.2 mg/kg. The steady-state plasma level of nicotine was 34.4 ng/ml, representing 6% of the total compound present at steady-state as determined by thin-layer chromatography. The distribution of nicotine or metabolite in mice which had received [methyl-14C]-nicotine orally was determined. Whole-body autoradiography, as well as direct tissue counting, demonstrated that nicotine accumulates in a number of areas, particularly the salivary gland, nasal epithelium, uterus, and liver. There was relatively little material in the blood or brain. This investigation indicates that ad libitum oral administration is an acceptable method for maintaining experimental animals on nicotine for long periods of time.

Administration, Oral↗
PubMed1981

In vitro susceptibility of Trichomonas vaginalis to zinc.

The prostate has long been considered to be a site of sequestration of Trichomonas vaginalis. From this reservoir, organisms are thought to be shed during intercourse and produce repeated infections in the female genitourinary tract. Bacteria known to cause prostatitis are inhibited by concentrations of zinc found in uninfected prostatic secretions. The present study demonstrates a similar inhibitory effect of zinc on the growth of T. vaginalis. This finding would suggest that, in otherwise healthy males, the prostate is not likely to be a reservoir for latent infection by these organisms.

In Vitro Techniques↗
PubMed1980

Adrenal myelolipoma associated with Cushing's disease.

An 18-year-old man with a history of Cushing's disease was treated with a total right and a near total left adrenalectomy in 1956. Pathologic examination of the operative specimen revealed bilateral adrenal hyperplasia. After 13 years, recurrence of symptoms of cortisol excess necessitated cobalt irradiation to the pituitary, which was without clinical effect. After an initial response to the adrenolytic agent, o,p'-DDD, partial relapse occurred. At this time, the recognition of an abdominal mass prompted abdominal exploration revealing a huge adrenal myelolipoma containing adrenal cortical cells distributed diffusely throughout the tumor. Symptoms of adrenal insufficiency developed, and adrenal steroid secretion did not respond to exogenous adrenocorticotropic hormone postoperatively. The case illustrates that adrenal myelolipomas may become very large with continued stimulation by adrenocorticotropic hormone, may contain significant amounts of adrenal cortical tissue, and may be associated with clinical hypercortisolism.

17-Hydroxycorticosteroids↗
PubMed1980

Immunocytochemical identification of trichomonads.

Trichomonas vaginalis is one of the more common pathogens of the genitourinary tract. Morphologic studies of trichomonal infections, however, have been hampered by the fragile nature of these thin-walled flagellates and the lack of specific histochemical procedures to identify the fragmented organisms found in tissue sections. These limitations have usually restricted positive identification to smears of freshly obtained specimens. In an attempt to overcome these limitations, a rabbit antiserum specific for Trichomonas organisms was produced by repeated subcutaneous injections of a documented strain of T vaginalis maintained in vitro. Using this antiserum, immunoperoxidase techniques have been modified so that trichomonads have been clearly identified both in smears and in paraffin-embedded tissue sections. This method seems to be useful in establishing the presence of these organisms in tissue and may subsequently contribute to the histopathologic definition of trichomoniasis in man.

Animals↗
PubMedDate not supplied

Immunoperoxidase staining of trichomonas vaginalis in cytologic material.

In the course of studies on the histopathology and pathogenesis of trichomonal infections, specific antisera to Trichomonas vaginalis were produced. Using these antisera, conventional immunocytochemical techniques were modified and applied to a variety of cytologic specimens. With this methodology, trichomonal organisms were identified in specimens from usual and unexpected locations. These findings plus the potential applications of similar methodologies to other areas of cytopathology are reported.

Animals↗