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Biomedical subjects

M Herman

Publications and source records attributed to M Herman.

120 records · Page 7Linked to original sources
PubMed1967

Voluntary control of microsaccades during maintained monocular fixation.

A contact-lens technique was used to record eye movements made by two subjects instructed either to "fixate" stationary white-light targets or to "hold" their eyes in position in the presence of the same targets. A marked reduction in saccade rate, frequently reaching zero throughout 9.8-second trials, was observed under the "hold" instruction.

Contact Lenses↗
PubMedDate not supplied

Experimental attempts to extend the current preimplantation genetic diagnosis with individual karyotypization of human blastomeres.

The drug-induced chromosome condensation using okadaic acid, a potent protein phosphatase inhibitor, was studied in day 1 to day 4 (D1-D4) spare human preimplantation embryos. In order to obtain cells for genetic tests, we developed a modified displacement blastomere biopsy method. During the okadaic acid treatment, approximately 40% of biopsied cells were lost due to heavy changes of the plasma membrane; this detrimental effect of okadaic acid differed markedly with the respect to the age of embryos. In comparison with the natural embryonic mitotic index, day 1 and day 2 embryonic cells gave increased yields of chromosome spreads (up to 51% of the initial D1-D2 cell number); on days 3 and 4 we were not able to obtain from surviving cells more than 31% blastomeres with condensed chromosomes (9% of total D3-D4 cell number). All chromosome spreads were successfully used for recycling in G-banding and subsequent FISH analysis.

Biopsy↗
PubMedDate not supplied

Comparison of three forms of bowel preparations for screening flexible sigmoidoscopy.

Our initial attempts at implementing a high-volume clinic were impeded by the quality of colon preparation. While two Fleet enema preparations were generally easy to administer and well tolerated, the results were frequently poor. Current studies are limited and opinions vary regarding the most effective bowel preparation. The purpose of this study was to compare three forms of bowel preparation for screening flexible sigmoidoscopy. All patients scheduled for screening flexible sigmoidoscopy were given one of three colon preparations: two Fleet enemas; magnesium citrate orally the evening before, clear liquid diet and two Dulcolax suppositories the day of the exam; or magnesium citrate orally the evening before, clear liquid the day of the exam, and two Fleet enemas 1 hour before the procedure. Examinations were performed using a video flexible sigmoidoscopy by specialty trained gastroenterologists. Physicians were asked to rate the preparations as excellent, good, fair, or poor according to explicit criteria, and to document depth of insertion. Results showed that the magnesium citrate and Fleet enema preparation was excellent for 70% of patients, allowing for greater depth of insertion. Need for repeat examination due to poor preparation was infrequent with this group and patient tolerance of the preparation was acceptable.

Analysis of Variance↗
PubMedDate not supplied

Small bowel obstruction due to a persistent omphalomesenteric duct.

We report a case of a Meckel diverticulum connected with the umbilicus through a fibrotic cord causing small bowel obstruction. On admission, the patient presented with an acute abdomen. A plain upright radiography of the abdomen, an ultrasonography of the abdomen, and an enema with gastrografin were performed, showing a small bowel obstruction at the level of the pre-terminal ileum, without revealing the cause. Urgent surgery followed, showing a persistent omphalomesenteric duct connected to the abdominal wall through a fibrotic cord, with a secondary volvulus of the small bowel. The remnant was resected and the volvulus reduced. The post-operative course was uneventful. Because of the serious complications and even possible mortality due to ischemic disease of the affected small bowel the possibility of a complicated persistent omphalomesenteric duct should be kept in mind, even if the preoperative work-up does not reveal a Meckel diverticulum.

Abdomen, Acute↗
PubMedDate not supplied

Effects of intravenous test dose epinephrine on fetal sheep during acute fetal stress and acidosis.

Small IV doses of epinephrine (epi; 5.0-20.0 micrograms), similar to those advocated for epidural test dosing, cause a significant though transient (3 minutes) reduction in uterine blood flow in pregnant ewes but no subsequent adverse effect on the mature, unstressed fetus. The purpose of this study was to investigate the acute effects on the mature fetus of a maternal IV test dose of 12.5 mg bupivacaine and 50.0 micrograms fentanyl with or without 16.5 micrograms epi in the presence of acute placental insufficiency and fetal asphyxia. Two minutes after dosing and for 15 minutes thereafter, no changes were observed in maternal heart rate (HR), mean arterial pressure (MAP) or arterial blood gas values and catecholamine concentrations other than a statistically significant doubling in epi levels after epi dosing. Mildly (mean arterial pH, 7.23) and severely (mean pH, 6.87) acidotic fetuses differed with respect to arterial pO2, pCO2 and catecholamine values, but in neither group were any changes observed after maternal dosing. Under the conditions of acute fetal stress and acidosis produced in this experiment, inclusion of epi 16.5 micrograms in an epidural test dose does not significantly affect the HR, MAP, aortic flow, blood gases or catecholamine levels of the mature fetal sheep when injected intravenously.

Acidosis↗