Biomedical subjects

B A Rowley

Publications and source records attributed to B A Rowley.

15 recordsLinked to original sources

PubMed1991

The computerized pupil.

An IBM-compatible computer graphics software program has been developed which simulates pupillary function. A light pen, electronically interfaced with the computer, simulates a pen light and, when it is placed on the computer image of the pupil, causes pupillary constriction; when it is withdrawn, the pupils redilate. A variety of abnormal pupillary responses are depicted. Anatomical diagrams and questions concerning various simulated pupillary conditions further enhances the educational experience. Medical students, residents in ophthalmology and the neurosciences, optometrists, nurses, ophthalmic assistants, and other health care professionals can utilize this program to learn a wide range of pupillary abnormalities in an interactive environment.

Audiovisual Aids↗

PubMed1988

Effects of hemoglobin perfusion on contractile function of the isolated ventricular septa.

Effects of three unmodified hemoglobin solutions on myocardial contractile function was evaluated using isolated perfused rabbit interventricular septa. The hemoglobin solutions tested were: a human hemoglobin solution (SFHS-A), a bovine hemoglobin prepared by a column chromatography (SFHS-B), and a bovine hemoglobin obtained by a ultrafiltration method (SFHS-C). Myocardial effects were assessed by comparing contractile parameters; developed tension (DT), resting tension (RT), and perfusion pressure (PP), measured before (control perfusion with Tyrode buffer) and during hemoglobin perfusion. Further, to examine the effects of hemoglobin solutions on myocardial contractility following a period of impaired flow, septal responses to a 10-minute period of ischemia (stopflow) were also studied. After a 10-minute perfusion with hemoglobin solution, SFHS-C increased DT to 124 +/- 12% (paired t-test, p less than 0.05) without causing a significant increase in RT or PP while SFHS-A and SFHS-B decreased DT to 96 +/- 20% (p greater than 0.05) and to 77 +/- 7% (p less than 0.05), respectively. A significant rise in PP (40-50% above baseline) was also noted with these solutions (p less than 0.05). Similarly, after a 30-minute reperfusion following a 10-minute ischemia, SFHS-C allowed significantly better percentage recovery (95 +/- 3%) than septa perfused with SFHS-A (81 +/- 2%) or SFHS-B (63 +/- 6%) (Student's t-test, p less than 0.05). These results indicate that hemoglobin solution, if properly prepared, does not seem to have acute deleterious effects on contractile function of the isolated heart.

Animals↗

PubMed1987

Stimulation of sciatic nerve regeneration in the adult rat by low-intensity electric current.

Morphometric analysis was used to evaluate regeneration in transected sciatic nerves of adult rats constantly stimulated with low-intensity direct current. The ends of the cut nerve were separated by a distance of 5 mm and inserted into a Silastic tube. Histological and electron microscopy criteria were used to measure and evaluate the cross-sectional area and the structure of the bridge connecting the distal and proximal stumps. After 3 weeks of stimulation (10 microA DC with distal cathode) the stimulated animals showed a cross-sectional bridge area twice the size of nonstimulated controls. The number of myelinated and unmyelinated axons, and the vascular areas, were also larger in the experimental group. This is the first quantitative analysis of low-intensity direct current-enhanced peripheral nerve regeneration in adult mammals.

Animals↗

PubMed1984

Renal oncocytoma: sonographic analysis of 14 cases.

The sonographic features of 15 histologically confirmed renal oncocytomas in 14 patients are presented. Lesions were evaluated for homogeneity, echogenicity, margination, venous invasion, and nodal enlargement. Nine were less than 5.5 cm in diameter, homogeneous, and well circumscribed. Three lesions were greater than 8 cm in diameter, contained areas of central necrosis or calcification, and were nonspecific for renal oncocytoma. One of these lesions (12 cm) contained a central scar. Two masses were slightly inhomogeneous and, at best, moderately circumscribed. In no case were metastatic nodes or venous invasion present. Since about 6% of renal cell carcinomas may have this appearance, the homogeneous, well marginated renal mass that is isoechoic with cortex and less than 5.5 cm in diameter is as likely to represent renal cell carcinoma as it is an oncocytoma. Although only present in one of the cases, the central fibrotic scar in a larger mass has been described in oncocytoma and may be the most specific feature. Preoperative investigation with fine-needle aspiration biopsy for cytology may be indicated in an attempt to avoid radical nephrectomy in selected patients.

Adenoma↗

PubMed1979