Suppression of serum iron-binding capacity and bone marrow cellularity in pigs fed aflatoxin.
Explore the source record for details and available documents.
Aflatoxins↗
Biomedical subjects
D E Clark
Publications and source records attributed to D E Clark.
Education in gastroenterology at a Japanese hospital. Medical and surgical aspects.
Admission to a standard 6-year university course in medicine is very competitive in Japan. Medical practice is dominated economically by a national health service and epidemiologically by diseases of the upper gastrointestinal tract. Gastric cancer is very common, although diseases familiar to Western society are increasing. A detailed examination of the educational program in gastroenterology at the Kitasato University Hospital, one of the newer private teaching hospitals in Japan, reflects the cultural and environmental differences from an American experience. A residency system on the American model has been developed at this hospital. The extensive training in gastroenterological diagnostic techniques, including contrast radiography and endoscopy, is most striking. The ability to describe pathological abnormalities with precision is given great emphasis. Subspecialty training in medical or surgical gastroenterology is not standardized and is oriented primarily toward research and the development of expertise in a limited academic area.
Fellowships and Scholarships↗
Effects of vomitoxin (deoxynivalenol) on conditioned saccharin aversion and food consumption in adult rats.
Vomitoxin is a trichothecene mycotoxin that induces feed refusal. Experiment I evaluated the potential aversive action of vomitoxin in a conditioned taste aversion paradigm. Adult male rats were fed either a control chow diet or a diet adulterated with 640 ppm lithium chloride (positive control) or with 2, 4 or 8 ppm vomitoxin and given access to a 0.1% saccharin solution and tap water during three training days. The rats were then shifted to a plain chow diet during 5 extinction days. Vomitoxin (8 ppm) and the positive control diet induced marked taste aversion commencing on the first day of exposure. Rats fed the 4 and 8 ppm vomitoxin diets ate less food only on the first day of contaminated diet exposure. Experiment II evaluated the potential action of vomitoxin on food palatability. Adult male rats were fed a powdered commercial chow for 5 days and then offered, in a preference test, a choice of chow and either: the same chow or chow adulterated with either 0.25, 0.50, 1.0, 2.0, 4.0 or 8.0 ppm vomitoxin. Relative to the total food intakes and the choice ratios (control chow consumed/total chow consumed) of the chow-chow groups, adulteration with 8 ppm vomitoxin resulted in a significant reduction in overall food intake, but not in food choice ratio and this effect of vomitoxin on feed consumption was observed only on day 1 of exposure. Vomitoxin, at 4 and 8 ppm, does not alter food palatability but does induce conditioned saccharin aversion.
Animals↗
Survival following nonpenetrating traumatic rupture of cardiac chambers.
We report the cases of 3 patients who survived cardiac chamber rupture resulting from blunt external trauma. All were drivers in motor vehicle collisions. All were seen with signs of pericardial tamponade and were treated by pericardiocentesis followed by emergency thoracotomy performed in the operating room. Ruptures of the right atrium and right and left ventricles were repaired by manual suture techniques without cardiopulmonary bypass. The cases of 37 previously reported patients who survived this injury are reviewed. We believe that patients with cardiac rupture who reach the hospital alive can often be saved by prompt diagnosis and immediate surgical treatment.
Accidents, Traffic↗
Ethanol consumption and free operant avoidance performance following exposure to dietary lead.
Rats were exposed ad libitum to a diet containing either 500 ppm lead (Group Lead-Diet) or a control diet with no added lead (Group Control-Diet). On Day 60 both groups were presented with a 15% ethanol solution (nonchoice test) in the home cage for five days prior to placement on a choice test that presented animals with a 10% ethanol solution and tap water. Concurrently with the choice test in the home cage, animals were placed in operant chambers for one hr (pre-avoidance) prior to a 30 min free operant avoidance session (avoidance) and remained there for one hr (post-avoidance) after training. Throughout avoidance training, the choice test was conducted in the chamber as well as the home cage. In addition to evidence of greater ethanol consumption by Group Lead-Diet rats, the results showed that these animals lever pressed more frequently, but not more efficiently, than Group Control-Diet animals.
Alcohol Drinking↗
Dietary lead increases ethanol consumption in the rat.
Rats fed either a diet containing 500 ppm (parts per million) Pb (as lead acetate) or an unadulterated control diet for 50 days were offered a 15% ethanol (ETOH) solution in a nonchoice (one-bottle) test situation. The results from this test indicated that Pb-diet animals consumed greater amounts of the ETOH solution than did controls. In a subsequent choice (three-bottle, two-fluid) test situation offering a nonpreferred ETOH solution or tap water as alternatives, Pb-diet animals once again ingested greater amounts of the ETOH solution. These findings are discussed in terms of possible Pb-induced increases in emotionality and the potential stress-reduction properties of ETOH.
Alcohol Drinking↗
Employment in health services: long-term trends and projections.
Demand for health services is expected to grow in response to the increasing number of elderly people; but growth prospects to 1995 for the industry's wage and salary workers are uncertain because of changes in both the financing and delivery of health care.
Employment↗
Tolerance and effect of chronic dietary cobalt on sheep.
Degeneration and necrosis of the testes and reduced spermatogenesis were recently observed in rats after prolonged intake of dietary cobalt (Co). The objective of the present study was to evaluate the effect of chronic Co intake on testicular and other tissues in sheep. Adult cross-bred rams were dosed daily for 70 days with gelatin capsules containing either 0, 3.0, or 4.5 mg Co/kg body weight. The Co dosages were increased on days 71 to 109 to 0, 10.0 and 15.0 mg Co/kg. Blood and serum samples were collected weekly and the rams were submitted to necropsy on day 109. Tissues were evaluated for histopathological changes and tissue Co residues and testicular spermatid reserves were determined. Highly significant (P less than 0.005) increases in Co levels were present in the blood, liver, kidney and testes of the treated rams. Neither gross nor microscopic lesions were observed in the testes or other tissues. Spermatid reserves remained unchanged. The absence of lesions and nonsignificant alterations in hematological and biochemical determinations indicated that prolonged exposure to Co at the dosages administered did not induce testicular degeneration in sheep and was tolerated without apparent pathological manifestations.
Animals↗
A novel inhibitor of mammalian collagenase.
N-[[[(5-chloro-2-benzothiazolyl)thiolphenyllacetyll-L-cysteine (WY-45,368) is a potent inhibitor of human skin fibroblast collagenase. Kinetic data show that the inhibition is competitive, with a Ki of 3.5 microM. WY-45,368 inhibits neither of two other metalloproteinases, thermolysin and angiotensin converting enzyme, nor does it inhibit clostridial collagenase--thus indicating specificity for mammalian collagenase.
Acetylcysteine↗
Effects of dietary cobalt on testicular structure.
Adult male rats were maintained on a diet containing 265 ppm cobalt for up to 98 days. Three rats were sacrificed weekly and assayed for testicular damage by light and electron microscopy. Testicular damage was first apparent after 70 days of treatment, followed by a progressive deterioration of cell architecture and decrease in testicular volume. The degenerative changes were of a very general nature; e.g., thickening of basal lamina and basement membranes, increased packing of red blood cells in veins and arteries, formation of "giant" cells, loss of sperm tail filaments, and degeneration of sperm mitochondria. No cobalt residues could be detected by energy dispersive x-ray microanalysis. These data indicate that testicular degeneration was not a primary response to cobalt and suggest that the testes become hypoxic due both to blockage of veins and arteries by red blood cells and to changes in permeability caused by thickening of basal lamina and basement membranes.
Animals↗
Dietary administration of nickel: effects on behavior and metallothionein levels.
Adult male rats were fed either 0, 10, or 20 mg Ni/kg body weight (as NiCl2) via a 10 g daily food ration. Following 14 days of exposure, animals were trained over a period of 61 days to lever press for food on a VI-2 operant training schedule while continuing to experience the indicated daily doses. Those rats treated with 20 mg/kg Ni lever pressed at a significantly lower rate than controls. Group 10 mg/kg subjects were not significantly different on this behavioral measure than control subjects. Atomic absorption spectrophotometric analysis revealed a dose/response accumulation of Ni in the kidney, but analyses of blood, bone, brain, hair, small intestine, liver, and testes did not show differential agent accumulations. Neither hepatic nor renal metallothionein levels were increased above control levels. These findings were discussed within the framework of other recent behavioral and biochemical studies of heavy metal toxicity.
Animals↗
Effects of guanethidine sympathectomy on feeding, drinking, weight gain and amphetamine anorexia in the rat.
Adult female rats that underwent sympathectomy induced by guanethidine treatment (10, 20 or 40 mg/kg) exhibited markedly increased water intake, but did not display significant alterations of either food intake, body weight, or the Lee Index of obesity. Guanethidine treatment did not attenuate amphetamine anorexia as evidenced by comparable dose-dependent reductions in food intake to d-amphetamine sulfate (0.25, 0.50, 1.0, and 2.0 mg/kg) in sympathectomized and control rats. These data are not consistent with the hypothesis that amphetamine anorexia is partially mediated via enhanced BAT thermogenesis.
Adipose Tissue, Brown↗
Trauma as a symptom of alcoholism.
Explore the source record for details and available documents.
Accidents↗
The effect of varied stride rate upon shank deceleration in running.
The purpose of this study was to determine the effects of systematic changes in stride rate and length at a given running speed on the peak shank deceleration (PSD) experienced during ground contact. Data were collected from 10 well-trained subjects as they ran on a treadmill at a pace of 3.8 m s-1 (7-min mile-1). Shank deceleration was measured by a lightweight accelerometer which was tightly attached over the distal medial tibia. High-speed films (200 Hz) were taken from a side view to quantify modifications in sagittal plane movement which might have accompanied the stride rate changes. Five stride rate conditions were randomly presented - 10% slower, 5% slower, normal, 5% faster and 10% faster. Average PSD was computed from 10 steps during each condition and testing was repeated on three different occasions. For each session, PSD observed for each condition was normalized to that observed at the normal stride rate in order to minimize the effects of variations in attachment of the accelerometer between and within subjects. The normalized PSD results at each stride rate tested were - normal = 1.0, 10% slower = 1.09, 5% slower = 1.03, 5% faster = 0.96 and 10% faster = 0.91. Significant differences were found between all these means except normal and 5% slower. The kinematic analysis revealed non-significant results for hip, knee and ankle joint angles at touchdown for the various stride rates. Application of the findings to existing analytical models indicated that, for a given running speed, peak impact forces in the ankle and knee joints decreased as stride rate increased.
Acceleration↗
Testicular degeneration and necrosis induced by dietary cobalt.
Dietary cobalt (265 ppm Co) induced polycythemia and consistent degenerative and necrotic lesions in the seminiferous tubules of rats. Cyanosis and engorgement of testicular vasculature on day 35 and thereafter was followed on day 70 by degenerative and necrotic changes in the germinal epithelium and Sertoli cells. Spermatogonia, primary spermatocytes and round spermatids were markedly affected, while elongated spermatids, spermatozoa, and sertoli cells were more resistant. Damaged tubules, often present side by side with normal tubules, contained multinucleated giant cells composed of degenerated and necrotic spermatocytes and/or spermatids, sloughed germinal and Sertoli cells, and calcified necrotic debris. Necrotic tubules were frequently collapsed and devoid of epithelium except for occasional spermatogonia and surviving Sertoli cells. Lesions were not observed in the Leydig cells, cauda epididymis or seminal vesicles.
Animals↗
Health: crossroads over the horizon?
Explore the source record for details and available documents.
Health Occupations↗
Mesoappendiceal paraganglioma.
A 10-cm tumor of the mesoappendix was removed from an asymptomatic 81-year-old woman, who is alive and healthy 5 years later. Histologically, the tumor was a paraganglioma. Five other case reports of paraganglioma involving the gastrointestinal tract distal to the duodenum are reviewed. The authors believe these tumors should be regarded as aberrant retroperitoneal paragangliomas.
Aged↗
The regional distribution of cadmium in the brains of orally exposed adult rats.
Cadmium (Cd) levels were measured in 13 dissected brain regions of adult male rats from 3 treatment groups. Rats (approximately 200 g each) were each fed 10 g/day of diets containing either 20 or 100 micrograms/g (ppm) Cd or control diet to which no Cd was added but contained approximately 0.35 ppm Cd. After 67 days of treatment, the brain of each rat was removed and each was dissected into 13 anatomical regions including olfactory bulbs, frontal cortex, rest of cortex, corpus callosum, hippocampus, amygdalae, corpus striatum, colliculum, tegmentum, thalamus, hypothalamus, pons-medulla, and cerebellum. Cd residues (dry weight) in each sample were determined by flameless atomic absorption spectrophotometry. With exception of the thalamus and olfactory bulbs, each of the brain regions of the 100 ppm Cd rats had more Cd than did those from either the 20 ppm Cd rats or controls which did not differ. There was evidence of selective accumulation of Cd within the olfactory bulbs of control and treated animals. This selective accumulation may be related to anosmia reported in workers with industrial exposure to Cd.
Animals↗