Biomedical subjects

J R Snell

Publications and source records attributed to J R Snell.

4 recordsLinked to original sources

PubMed1996

Partial wave in human seminiferous tubules appears to be a random occurrence.

Serial cross sections were evaluated to determine the architectural arrangement of stages among men with varied spermatogenic efficiencies. Using autopsy specimens, glutaraldehyde-perfused testes from men with low or high daily sperm production per g parenchyma were compared. Lobes of testicular parenchyma were teased from connective tissue septa, further fixed in osmium, and embedded such that the straight portions of tubules could be sectioned perpendicularly. Unstained 22 microns serial sections were sectioned optically with Nomarski optics. Paired photomicrographs of each tubular cross section were taken under a 40 x objective, and stages of the spermatogenic cycle were mapped by two observers using Clermont's criteria (Clermont, 1963). For comparison, numbers (1-6) were assigned randomly to the stages, the stages were plotted in two dimensions (length and circumference of tubule) as if the tubule were cut down its length and laid flat, and geometric centers were plotted for each stage. Geometric centers consecutive and/or non-consecutive stages appeared to form an angle down the length of the tubule. When considering helical patterns along the tubule, men with neither low nor high spermatogenic efficiency had a complete wave composed of all six consecutive stages. The helical pattern of geometric centers indicated only 2-4 consecutive stages when the actual values of stages were used or when random numbers were substituted for actual numerical value of stages. The number of consecutive stages in tubules from these men was not different from consecutiveness found when stages were assigned random numbers. Given that no complete wave was found, regardless of spermatogenic efficiency, and that the degree of consecutiveness of stages down a helical pattern in human seminiferous tubules could be generated from random numbers, the arrangement of stages in human seminiferous tubules may simply be a random occurrence.

Analysis of Variance↗

PubMed1996

Myocardial infarction as the presenting manifestation of systemic lupus erythematosus with antiphosphatidylserine antibodies.

BACKGROUND: The presence of antiphospholipid antibodies has been associated with thrombotic events in systemic lupus erythematosus and other diseases. Antiphosphatidylserine antibodies have been shown more recently to have clinical implications being noted in thrombocytopenia, positive VDRL test, prolonged partial thromboplastin time, and recurrent fetal loss. OBJECTIVE: To report a patient with systemic lupus erythematosus who presented with a myocardial infarction resulting from a single clot in the distal left anterior descending coronary artery and to discuss the merits of evaluating such patients for the presence of antiphospholipid antibodies. METHODS: Case report and review of the literature. RESULTS: A 55-year-old woman with no risk factors for coronary artery disease presented with a myocardial infarction. A distal left anterior descending coronary artery clot was seen on angiography. Evaluation for the presence of a hypercoagulable state revealed evidence for systemic lupus erythematosus. Although lupus anti-coagulant and anticardiolipin antibody titers were negative, antiphosphatidylserine IgA antibodies were detected. CONCLUSION: Because antiphosphatidylserine antibodies of the IgA isotype have been shown to be associated with thrombosis and other manifestations of systemic lupus erythematosus, a complete evaluation for antiphospholipid antibodies should include testing for all three isotypes.

Antibodies, Antiphospholipid↗

PubMed1991

A veterinary digital anatomical database.

This paper describes the Veterinary Digital Anatomical Database Project. The purpose of the project is to investigate the construction and use of digitally stored anatomical models. We will be discussing the overall project goals and the results to date. Digital anatomical models are 3 dimensional, solid model representations of normal anatomy. The digital representations are electronically stored and can be manipulated and displayed on a computer graphics workstation. A digital database of anatomical structures can be used in conjunction with gross dissection in teaching normal anatomy to first year students in the professional curriculum. The computer model gives students the opportunity to "discover" relationships between anatomical structures that may have been destroyed or may not be obvious in the gross dissection. By using a digital database, the student will have the ability to view and manipulate anatomical structures in ways that are not available through interactive video disk (IVD). IVD constrains the student to preselected views and sections stored on the disk.

Anatomy, Veterinary↗

PubMed1975

Control of microflora in stallion semen with a semen extender.

Sterile equipment was used to collect ten ejaculates from each of ten normal stallions and quantitative and qualitative bacterial counts were made within 15 min after collection. The mean bacterial population in undiluted semen was found to be 573,000 +/- 374,000 organisms/ml. The bacterial content of semen diluted with two parts sterile physiological saline, or with two parts of a cream-gelatin extender, was measured within 15 min after collection and again after 2 hr at 25 degrees C. The number of bacteria was slightly increased in the saline after 2 hr, but 1 93% and 99% reduction occurred in the extended semen within 15 min and after 2 hr at room temperature.

Animals↗