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Biomedical subjects

H Warner

Publications and source records attributed to H Warner.

At least 37 records · Page 2Linked to original sources
PubMed1983

Initiation of erection and semen release by rectal probe electrostimulation (RPE).

Instrumentation and methodology are described for rectal probe electrostimulation (RPE) in human males to elicit erection and allow semen collection. This system virtually eliminates shock hazard; the simultaneous monitoring of current, voltage and impedance ensures reliability and repeatability. It was tested with 8 neurologically intact subjects, and 12 paraplegic patients with lesions between T4 and L2. Platinum electrodes delivered current (density never exceeding 0.37 mA per mm. at the electrode) at frequencies of 60 Hz, 20 Hz, and 0.25 Hz. Erection was elicited repeatably in only 1 of the intact subjects, and no seminal emissions or ejaculations occurred. Discomfort prevented current delivery beyond levels even 50 per cent of those safely acceptable. Six of 10 paraplegic patients (2 others had penile implants) developed erections with 20 Hz; the other 2 frequencies were much less effective. The extent of RPE-induced penile tumescence varied directly with electrode surface area and applied current intensity. Discomfort was minimal. Retrograde seminal emission in 5 of the 12 paraplegics was verified by post-stimulation recovery of sperm via voiding or bladder irrigation via catheter. Although motility was very low, 4 of 8 recovered bladder-urine/seminal fluid specimens indicated sperm counts and morphology consonant with use in artificial insemination. Thus, RPE, if combined with techniques to allow antegrade semen collection, may be a useful technique for spinal cord-injured men who, as part of their sexual rehabilitation, are interested in siring children.

Adult↗
PubMed1980

Effects of glucose on insulin release and on intermediary metabolism of isolated perifused pancreatic islets from fed and fasted rats.

We examined the relationship between glucose-induced insulin release and the intermediary metabolism of islets from fed and fasted rats. Isolated islets were perifused and insulin release measured in the effluent. At various times after switching islets from 2.4 to 8.6 or 14.5 mM glucose or from 2.4 to 14.5 and back to 2.4 mM glucose, islets were quickly frozen, freeze dried, and subsequently analyzed for tissue content of glucose-6-P, fructose-1,6-P2 plus triose-P, Pi, ATP, ADP, 5'-AMP, NADH, NADPH, total NAD, and total NADP using enzymatic fluorometric procedures. When islets from fed rats were exposed to high glucose, there were concomitant increases of insulin release and islet content of glucose-6-P, fructose-1,6-P2 plus triose-P, NADH, and NADPH. During stimulation Pi and 5'-AMP content fell markedly. The total adenine nucleotide content remained constant. Similar secretory and metabolic changes occurred when 1.5 mM Pi was added to the perifusion fluid. When glucose-stimulated islets were switched back to low glucose for 10 min, all substances but fructose-1,6-P2 plus triose-P, 5'-AMP, NADPH, and possibly ATP returned to the prestimulatory level. Starvation of rats for 3 days blocked the secretory response to 8.6 mM glucose. Fructose-1,6-P2 plus triose-P rose but it did not attain the level existing in islets from fed rats. The ratios (ATP)/(5'-AMP) and (ATP)/(Pi)(adp) increased to the values observed in glucose-stimulated islets of fed rats. The metabolic changes in islets from fed rats exposed to high glucose are consistent with an activation of glycolysis occurring concomitantly with stimulated rates of insulin release. This occurs despite the decrease of important activators of glycolysis--Pi and 5'-AMP. The enhanced glycolysis possibly results from P-fructokinase activation by increased fructose-6-P levels. Activation of glycolysis with 8.6 mM glucose was not as pronounced in islets from starved rats. Despite the different secretory response of islets from fet and fasted rats, the changes of phosphorylation state in the islets, in particular, Pi and 5'-AMP levels, were similar.

Adenosine Diphosphate↗
PubMed1979

Myocardial infarct imaging with 99mTc-pyrophosphate and 99mTc-methylene diphosphonate: lack of correlation.

A prospective study of eight patients with recent transmural myocardial infarction was performed using 99mTc-Sn-pyrophosphate and 99mTc-Sn-methylene diphosphonate in each patient. All pyrophosphate scans were strongly positive whereas the diphosphonate scan was strongly positive in only one case. We conclude that 99mTc-Sn-pyrophosphate is preferable to 99mTc-Sn-methylene diphosphonate for myocardial imaging.

Diphosphates↗
PubMed1978

Relationship between diazepam dose, plasma level, age, and central nervous system depression.

Patients undergoing elective cardioversion for treatment of arrhythmias were premedicated with diazepam. The dose was individualized to achieve a degree of central nervous system CNS) depression characterized by response to painful but not vocal stimulation. Promptly following each cardioversion, blood was drawn and the plasma diazepam concentration was measured by gas chromatography. The plasma levels varied as widely as the diazepam doses so that there was no fixed plasma level of diazepam associated with the degree of CNS depression produced in these patients. However, both the dose of diazepam and the resulting plasma level were inversely correlated to age, indicating that age is a critical factor in the use of diazepam for cardioversion premedication; elderly are more sensitive to the depressant effects of this drug than the young.

Adult↗
PubMed1978

Rectal probe electroejaculation of primates.

The technique of rectal probe electroejaculation has been developed to permit collection of semen using equipment proven safe, simple, and effective on the 30 primate species so far tested. This paper provides information on the construction and operation of this equipment, together with electrical parameters applicable to primate species. Seminal emission or ejaculation occurs in all species when alternating current is delivered at 0.25 mA/mm2 electrode area. The most effective frequency is 20 Hz, and the most acceptable anesthetic is ketamine hydrochloride.

Animals↗
PubMed1977

The association between basal body temperature, sexual swelling and urinary gonadal hormone levels in the menstrual cycle of the chimpanzee.

Basal body temperature (BBT) was measured continuously by radiotelemetry throughout 14 chimpanzee menstrual cycles and correlated with daily observations of the sexual skin swelling. A biphasic BBT shift from a pre-nadir mean of 36-12 degrees C to a post-nadir mean of 36-67 degrees C was observed in 12 cycles. The temperature nadir showed a close temporal relationship with detumescence of the sexual skin swelling (an early luteal event), but the rate of temperature rise after the nadir was variable. In 3 normal cycles studied, the temperature nadir occurred the day after a urinary oestrone peak, but there was no consistent temporal association between BBT rise and pregnanediol increment. Progesterone secretion is therefore probably not the sole determinant of the BBT shift; the changing oestrogen/progestin ratio may be the more important factor regulating body temperature during the luteal phase.

Animals↗
PubMed1975

Polymorphic acetylation procainamide in man.

N-Acetylprocainamide (NAPA) and procainamide plasma and urine concentrations were determined by thin-layer chromatography (TLC) densitometry in people of known acetylator phenotype (dapsone phenotyping) taking procainamide for more than 3 days. The plasma NAPA/procainamide ratio 3 hr after the last dose for fast acetylators (mean plus or minus SD) is 1.8 plus or minus 0.59 (N equal to 8) and for slow acetylators, 0.61 plus or minus 0.09 (N equal to 6) P smaller than 0.001). The renal clearance of NAPA averaged 1.2 times the simultaneously measured endogenous creatinine clearance, whereas procainamide clearance was approximately double the creatinine clearance. There was no difference between slow and rapid acetylators in the renal clearance of either drug or the urine pH, indicating that the difference in plasma NAPA/procainamide ratios between these two groups is due to differences in their rates of acetylation. Therefore, procainamide is probably acetylated by the polymorphic N-acetyltransferase in man. Reflecting the blood level differences, the NAPA/procainamide ratio in urine (collected 99 to 180 min after last dose) was found to be higher in rapid than in slow acetylators. The plasma protein binding of NAa and of procainamide are similar. Since NAPA seems to have an antiarrhythmic potency similar to procainamide, NAPA probably contributes to the antiarrhythmic activity of procainamide therapy, especially in genetic rapid acetylators.

Acetylation↗
PubMed1975

Cytochemical response of kidney, liver and nervous system of fluoride ions in drinking water.

Morphological and cytochemical studies on the squirrel monkey have been made after maintaining the sujects on pure distilled water and fluoridated distilled water for 18 months with the objective of determining the effect of fluoride on the activity of some hydrolytic and oxidative enzymes in the kidney, liver and nervous system. Daily water intake by individual animals was measured over the final 10 months of the animal's exposure to 0,1 and 5 ppm fluoride. Water consumption was considerably higher in the animals on higher fluoride intake. Whereas the nervous system remained totally unaffected by this experimental procedure, the liver showed a slightly enhanced acivity of Krebs citric acid cycle enzymes. The kidneys, however, showed significant cytochemical changes, especially in the animals on 5 ppm fluoride intake in their drinking water. In these animals, the glomeruli showed an increase in the activity of acid phosphatase and the enzymes belonging to the citric acid cycle and the pentose shunt, whereas lactate dehydrogenase, a resentative of the anaerobic glyoclytic pathway, remained unchanged or only slightly changed. These observations suggest that fluoride in concentrations as low as 5 ppm interferes to some extent with the intracellular metabolism of the excretory system.

Acid Phosphatase↗
PubMed1975

Assessment of ventricular function in coronary artery disease using nitroglycerin and computerized analysis of left ventriculograms.

The ability to predict if abnormalities in regional wall motion are reversible would assist in selecting patients for aortocoronary bypass operation. This study shows that asynergic areas of the ventricle may be reversed by nitroglycerin. Thirty-four asynergic areas in 30 patients with coronary artery disease were studied before and after administration of nitroglycerin. Nineteen patients with previous infarction, diagnostic Q waves in their electrocardiogram, and akinetic areas in the left ventricle had no change in their akinetic areas after nitroglycerin administration. Nine of these patients did show increased motion in other hypokinetic areas of the myocardium. Five of 11 patients with no evidence of previous infarction showed a dramatic improvement in akinetic areas after nitroglycerin, while of the remaining 6, 5 showed mild improvement. This illustrates that recoverable asynergic areas may be recognized by nitroglycerin.

Adult↗
PubMed1975

Conversations with a chimpanzee in a computer-controlled environment.

The linguistic-type skills of a young chimpanzee (Pan) acquired in a computer-controlled language-training situation are reviewed. Those skills include facile acquisition of vocabulary, object naming, color naming, appropriate use of "yes" and "no" in response to certain questions, and conversation. In conversations the subject has formulated novel sentences and without special training has asked that objects be named, whereupon requests were made that they be given to her. These findings are interpreted in terms of how enriched environments can serve to bring forth novel communication skills in the chimpanzee, which is otherwise alinguistic; how the challenge of the environment can serve to limit manifest intelligence; and how a cognitive, rather than the traditional stimulus-response, framework is required for understanding the communication skills and psychological processes of the chimpanzee.

Animals↗