Biomedical subjects

N R Peterson

Publications and source records attributed to N R Peterson.

5 recordsLinked to original sources

PubMed2000

Positive and negative biopsies in the pre-prostate specific antigen and prostate specific antigen eras, 1980 to 1997.

PURPOSE: We assess temporal trends in prostate biopsy incidence, utilization and cancer yield in the community before and after the introduction of serum prostate specific antigen (PSA) to the community medical practice MATERIALS AND METHODS: Study subjects comprised all Olmsted County men with a first prostate biopsy performed between January 1, 1980 and December 31, 1997. Medical records of all study subjects (1,729) were reviewed for clinical information from the first and all subsequent biopsies. RESULTS: Annual age adjusted prostate biopsy incidence increased from 113/100, 000 (95% confidence interval 76, 150) in 1980 to 487/100,000 (421, 554) in 1992 and decreased to 264/100,000 (219, 309) in 1997. For men 50 to 59 years old biopsy incidence increased 400% from 137/100, 000 in 1980 to 1986 to 686/100,000 in 1993 to 1997. Overall, there were 93/100,000 more negative biopsies and 49/100,000 more positive biopsies in 1993 to 1997 than in 1980 to 1986. The overall cancer yield of 36% was essentially unchanged across periods (p = 0.6). However, by age cancer yield decreased from 29% to 21% (1980 to 1986 versus 1993 to 1997) for men 50 to 59 years old but increased from 38% to 45% for those 70 to 79 years old. CONCLUSIONS: Overall cancer yield from prostate biopsies has changed little during the last 15 years. Increased cancer yield for men 70 years old or older has been offset by the decreased yield in younger men. Attention must now be given to diagnostic techniques which might reduce the incidence of negative biopsies and improve cancer yield in younger men.

Aged↗

PubMed1990

Clinical and molecular evaluation of acetowhite genital lesions in men.

A total of 108 male partners of women with cervical condyloma and/or dysplasia underwent evaluation for gross and subclinical condyloma via acetic acid screening with a magnified examination. Biopsies of acetowhite genital skin were obtained for histological and deoxyribonucleic acid hybridization analysis. Of the men 52 (49%) had acetowhite lesions and underwent biopsies, 44 of which were evaluable by histological and deoxyribonucleic acid analyses. Of the lesions 12 had features of condyloma or penile intra-epithelial neoplasia, among which 7 (58%) contained human papillomavirus deoxyribonucleic acid. The remaining 32 lesions revealed minimal histological changes sometimes suggesting condyloma. However, only 5 of the 32 biopsies (16%) contained human papillomavirus deoxyribonucleic acid. A tendency to overdiagnose condyloma based on histological findings is suggested. Criteria by which to identify best human papillomavirus-related morphology are presented. Acetowhite genital epithelia with minor (nonspecific) histological changes correlate poorly with human papillomavirus nucleic acids and in most cases do not represent disease involving common viral types. The application of appropriate histological criteria appears to be particularly relevant to management strategies that avoid overtreatment of minor epithelial abnormalities. It remains unclear whether acetowhite genital epithelia positive for human papillomavirus require treatment given the high tendency for recurrence and lack of demonstrated effect on the natural history of cervical carcinoma.

Acetates↗

PubMed1988

Ureteral duplication with lower pole ectopia to the epididymis.

We report a unique case of a duplex ureter with ureteral ectopia. A 30-year-old man presented with a coliform infection of the epididymis and excretory urography revealed, in addition to a normal-appearing right renal collecting system, a second right ureter that arose from an inferior calix, penetrated the lower pole parenchyma and drained directly into the ipsilateral epididymis. The radiological evaluation and surgical management are discussed, and several embryological explanations for this anomaly are offered.

Adult↗

PubMed1983

Pseudotorsion of testis.

Unilateral scrotal inflammation was noted in an otherwise asymptomatic three-day-old male and was initially believed to be due to testicular torsion. It proved, however, to be the result of peritonitis from a thermometer-induced rectal perforation presenting via a communicating hydrocele. Treatment included primary closure of the rectal perforation with colostomy diversion combined with parenteral antibiotics. Preoperative evaluation of neonates with acute unilateral inflammation of the scrotum and a known hydrocele or hernia with flat and oblique x-ray films may reveal significant unsuspected intra-abdominal pathology.

Anti-Bacterial Agents↗

PubMed1972

Characterization of spheroplast membranes of Neisseria meningitidis group B.

Spheroplast membranes (spheroplast envelopes) of strain 2091 of group B Neisseria meningitidis were prepared by a procedure that included lysozyme treatment of the cells and osmotic lysis of the resulting spheroplasts. Electron microscopy revealed that the membranes consisted of two unit layers, generally parallel to each other. The membrane preparation migrated as a single component in a 40 to 70% sucrose gradient and consisted of 62% protein, 28% lipid, 9% ribonucleic acid, small amounts of carbohydrate, hexosamine, and deoxyribonucleic acid. When 1 or 10 mug (dry weight) was injected intravenously into rabbits, a mild pyrogenic reaction was elicited. In immunodiffusion tests, immune rabbit serum prepared against spheroplast membranes produced three major precipitin lines, with the homologous antigen solubilized with sodium dodecyl sulfate, and a single line with untreated antigen. The immune serum also reacted with a cell wall antigen, and to a lesser extent with some of the cytoplasmic antigens. Succinate dehydrogenase and reduced nicotinamide adenine dinucleotide (NADH) oxidase activities were found to be associated with the spheroplast membranes. NADH dehydrogenase also was associated with the membranes but was gradually released and recovered in other fractions. Glutamate-oxaloacetate transaminase, glutamate, glucose-6-phosphate, and isocitrate dehydrogenase activities were not found in the membrane preparation. About one-third of these enzymatic activities were recovered in the supernatant fluid after the sedimentation of the spheroplasts and two-thirds were recovered in the cytoplasmic fraction. N-acetylneuraminic acid (NAN)-condensing enzyme and cytidine monophosphate-NAN synthesizing enzyme also were identified in this organism. These enzymes were not associated with the membranes and were recovered from extracts from whole cells, spheroplasts, or cells exposed to osmotic shock, as well as from spheroplast supernatant and shock fluids. It is concluded that the spheroplast membranes of the strain of meningococci used in these studies are typical of those recovered from gram-negative bacteria.

Animals↗