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Biomedical subjects

H Markowitz

Publications and source records attributed to H Markowitz.

8 recordsLinked to original sources
PubMed1990

Responses of female rhesus macaques to an environmental enrichment apparatus.

Environmental enrichment devices are a potential way to enhance psychological well-being in laboratory animals. The effects of such devices need to be systematically evaluated before they are recommended for widespread use. The purpose of this research was to monitor the behavioural and physiological responses of adult female rhesus macaques to a simple enrichment device. The apparatus consisted of a box attached to the monkey's home cage that contained a radio and a food dispenser, which could be controlled by the monkeys via contact detectors. Radio and food dispenser use were automatically recorded. Whole blood serotonin (WBS), plasma cortisol and abnormal behaviour were measured in 5 monkeys before, during and after a 20-week period in which the monkey's cages were equipped with the device. All monkeys used the device (3 of the 5 subjects earned an average of more than 200 food pellets per day). Mean plasma cortisol and whole blood serotonin did not differ across sampling times, suggesting that the apparatus had no effect on basal stress levels. There was an inverse relationship between apparatus use and cortisol levels in 76% of the samples, but only 3 of 17 coefficients were significant. There was a significant but small negative correlation between apparatus use and self-abusive behaviour. This enrichment device was readily used by adult rhesus monkeys and could be adapted for use in a wide variety of laboratory settings.

Animals↗
PubMed1990

Opposite effects of diabetes on nephrotoxic and ischemic acute tubular necrosis.

The effect of streptozotocin-induced diabetes mellitus on two different models of acute tubular necrosis (ATN), was studied: (i) the nephrotoxic model of HgCl2-induced ATN and (ii) the ischemic model of renal artery clamping for 60 min. Induction of ATN with HgCl2 in normal rats decreased CrCl from 0.67 +/- 0.05 to 0.1 +/- 0.019 ml/min (P less than 0.001) after 24 hr, and it deteriorated further to 0.03 +/- 0.013 ml/min after 48 hr; whereas, in the diabetic rats, HgCl2 decreased CrCl from 0.98 +/- 0.11 only to 0.31 +/- 0.037 ml/min (P less than 0.0001), but CrCl recovered to 0.50 +/- 0.08 ml/min after 48 hr. Bilateral clamping of renal arteries for 60 min in control and diabetic rats extremely decreased CrCl in both groups. Twenty-four hours after clamping, two of nine rats from the diabetic group died, whereas none from the control group died. Forty-eight hours after clamping, all nine rats from the diabetic group died, whereas only two rats from the control group died, and in the four surviving rats CrCl recovered slightly. Our study shows that streptozotocin-induced diabetes could not confer a general protection against ATN. It was protective against a nephrotoxic insult but aggravated the ischemic insult. An attempt to reconcile these discrepant effects is made in the Discussion.

Acute Kidney Injury↗
PubMed1989

Influence of cage size on heart rate and behavior in rhesus monkeys.

We studied 6 singly caged adult female rhesus monkeys to determine whether increased cage size had any effect on behavior or heart rate. Two monkeys at a time were placed in cages 40% larger than their standard cage for 1 week on 2 occasions, using a counter-balanced design. Direct behavioral observations were performed 75 minutes/week on each monkey. Heart rate and general activity were monitored 35 hours/week by a telemetry system. Statistically significant differences were not found in aggressive, submissive, abnormal, or self-abusive behavior, nor in time spent in the front half of the cage, duration of grooming, looking at the observer, or stereotyped or nonstereotyped locomotion. Vocalizations increased the first time in the larger cage, but not the second, and decreased upon the second return to the standard cage. Differences with respect to cage size were not found in heart rate or activity level, although there were significant variations at different times of day. We conclude that modest increases in cage size are unlikely to enrich the environment of singly caged laboratory primates.

Animals↗
PubMed1977

Quantitative method for estimating myoglobin in urine.

A simple, rapid, and quantitative immunochemical technique is described for quantitation of urinary myoglobin. The test is specific for myoglobin in the presence of hemoglobin or tissue constituents, can be completed within 1 h or less, and can detect 1 to 2 mg/liter. Normal urinary myoglobin concentrations are less than this.

Animals↗
PubMed1976

Problems with beaded fluorescence pattern in FTA-ABS test.

The significance of false-positive FTA-ABS fluorescence in connective tissue diseases and other clinical conditions was evaluated by studying the serum from several groups of patients. In 12% of 67 patients without syphilis, serum with an antinuclear antibody (ANA) titer of 1:32 or greater gave low intensity FTA-ABS test fluorescence. In 20% of 150, patients (2.7% with a history of syphilis), serum with rheumatoid factor (RF) titers of 1:640 or greater demonstrated some reactivity. Only 1.3% of 75 donors of normal blood showed low-grade FTA-ABS fluorescence. In 385 patients with diagnostic problems, 2.1% of the serum demonstrated the beaded pattern. Patterns varied, depending on the treponemal antigen preparation and the duration of serum storage. Also, multiple specimens from the same patient produced different patterns. Furthermore, the beaded pattern could be demonstrated in patients with a history of syphilis, with other medical disorders, and in apparently normal persons.

Antibodies, Antinuclear↗
PubMed1975

Do elephants ever forget?

Three adult female elephants (Elephas maximus) were tested on a light-dark discrimination problem with an 8-yr intertrial interval. The first subject took only 6 min to reach criterion and made only two errors, suggesting remarkable retention. The other two subjects were found to have visual anomalies that would have gone undetected without this research.

Animals↗