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Biomedical subjects

M Horowitz

Publications and source records attributed to M Horowitz.

At least 541 records · Page 30Linked to original sources

Regional [14C]misonidazole distribution in experimental RT-9 brain tumors.

Regional [14C]misonidazole-derived radioactivity (MISO) was measured by quantitative autoradiography in experimental RT-9 brain tumors 0.5, 2, and 4 hr after an i.v. bolus (25 mg) and constant infusion (10 mg/hr). Misonidazole (MISO) concentration in plasma and brain was also measured by high-pressure liquid chromatography; the brain/plasma MISO ratio ranged between 0.5 and 0.7. MISO equivalents were calculated from tissue or plasma 14C radioactivity and [14C]MISO specific activity data. The MISO/MISO equivalents ratio, which represents the nonmetabolized fraction of [14C]MISO, fell gradually in plasma (0.89 at 4 hr) and more rapidly in brain (0.67 at 4 hr) and tumor (0.30 at 4 hr). MISO distributed uniformly throughout the brain at all three time periods. In contrast, MISO distribution in tumor was variable, and tumor concentrations relative to that in brain increased with time. The average tumor/brain MISO ratio was 1.3, 1.7, and 2.6 at 0.5, 2, and 4 hr, respectively, which suggests tumor uptake and binding of MISO or, more likely, MISO-derived 14C-labeled metabolites. In addition, MISO distribution in tumor tissue was strikingly heterogeneous at 4 hr, resulting in an average high/low tumor activity ratio of 4/1 and an average high tumor/brain ratio of 5/1. Tumor regions with high MISO activity correlated in part to viable-appearing cells around necrotic foci.

Animals↗

Measurement of gastric emptying after gastric bypass surgery using radionuclides.

The pattern of gastric emptying has been assessed after gastric bypass surgery using a double isotope technique for measuring solid and liquid emptying with a scintillation camera. Eleven control subjects and 12 patients, 12 months post-gastric bypass, were studied. Stomal and gastric pouch size were assessed at endoscopy. Solid emptying was slower and liquid emptying was more rapid after gastric bypass surgery. Initial rapid emptying of solid occurred in the 4 patients with the smallest pouch diameters. There was no correlation between stomal size and rates of solid or liquid emptying nor between the weight loss produced by the operation and the rates of solid or liquid emptying, stoma or pouch size.

Adult↗

Effect of modification of fluid intake in the puerperium on serum prolactin levels and lactation.

Twenty-one puerperal women were divided into two groups, those with high (4 L/day) and those with low (800 mL/day) fluid intake. Basal and post-suckling serum prolactin levels and the production rate of breast milk were similar in each group. Osmotic influences on prolactin secretion appear to be unimportant in human physiology, and there is no basis for prescribing changes in fluid intake for the control of human lactation.

Female↗

Strachan's syndrome 30 years after onset.

While a prisoner-of-war in Malaya from 1942-1945, a 29-year-old man developed a painful sensorimotor neuropathy, bilateral central scotomata and sensorineural deafness. Examination 34 years later, after a long period of adequate nutrition, revealed considerable residual deficit. Nerve conduction studies suggested axonal degeneration with prominent collateral reinnervation. This case of Strachan's syndrome is reported to draw attention to the limited functional recovery and to focus attention on this condition at a time when famine conditions are rife in Southeast Asia.

Aged↗

News of risk for early heart disease as a stressful event.

Modern prevention includes efforts to reduce the frequency of coronary heart disease by screening populations for certain risk factors, and then advising persons high in risk on how to alter their vulnerability. But what is the effect of telling persons they are at increased risk for such threatening events as heart attacks? Without such information they may not be motivated to change such behavior as cigarette smoking or to comply with blood pressure reducing regimens. With it, worry about their health status may increase. The present study examined such variables in 575 men with no previous symptoms of heart disease who were informed of increased risk and followed for three years. The men were divided at random into two groups of equal size. A Special Intervention group received repeated reminders of risk and procedures for cessation of smoking, reduction of blood pressure, and dietary alteration to lower serum cholesterol. A contrast group received usual medical care, as they saw fit, in response to the news of risk. At yearly intervals, scores on level of subjective distress, avoidance, and coping were obtained. One-third of the men reported intrusive or avoidance experiences one year after receipt of the news of increased risk. The Special Intervention group, with its more frequent reminders, had significantly higher levels of intrusive ideas and feelings about the news of risk than the Usual Care group, and significantly higher levels of coping experiences.

Adult↗

Clinical evaluation of the sliding compression screw in 121 hip fractures.

Between August 1975 and June 1978, the orthopedic residents at the Jacksonville Health Education Program have used the sliding compression screw to treat 135 hip fractures. The 121 of these being reported include 27 subcapital and femoral neck fractures, 88 intertrochanteric fractures, and six subtrochanteric fractures. Patients' ages ranged from 23 to 98 years, with a mean age of 64. Accurate anatomic reduction of the fracture fragments, be it open or closed, and attention to detail in the placement of the compression screws were thought to be major factors favoring a good result. As confidence was gained in the stability of fixation, appropriate patients were allowed postoperative weight-bearing regimes. It was further concluded that the ability of the sliding screw to allow for a "self-seeking equilibrium" of the fracture fragments obviated the need for primary medial displacement in unstable fractures in almost all instances.

Adult↗

Suppressor cells in vitro: differential effects of indomethacin and related compounds.

In vitro immune response systems known to involve suppressor cell regulation were examined for effects produced by the drug indomethacin and other compounds known to inhibit the cyclooxygenase pathway of arachidonic acid metabolism. In all cases tested where suppressor T cell activity is known to be the dominant inhibitory mechanism, suppression was not blocked by drug addition and was sometimes more pronounced. In the cases tested where suppression could be attributed to a non-T cell, most likely a macrophage-like cell (M0), suppression could be abolished by drug treatment. Indomethacin and related compounds may be useful analytical tools for separation of T cell vs. non-T cell mediated suppression.

Animals↗

Herbicidal treatments for control of Papaver somniferum L.

Fifty-five commercially available herbicides were evaluated for possible use to destroy illicit opium poppy crops (Papaver somniferum). In the first stage, herbicides were sprayed on poppy plants grown in containers. The following compounds killed poppy plants: (a) herbicides with typical foliar activity--amitrole, bromoxynil, 2,4-D, glyphosate, ioxynil and paraquat; and (b) herbicides with root and foliar activity--the triazines ametryn, atrazine, metribuzin, prometryn, simazine and terbutryn; the substituted ureas benzthiazuron, chloroxuron, diuron, fluometuron, linuron, methabenzthiazuron, neburon and phenobenzuron; and the miscellaneous compounds karbutilate, methazole, oxadiazon and pyrazon. Severe but sublethal injury was caused by cycloate, EPTC, molinate, pobulate, cacodylate + MSMA, ethofumesate, perfluidone and phenmedipham. Abnormal development of vegetative or reproductive parts of the plant was induced by benefin, butralin, dinitramine, pendimethalin, trifluralin, diphenamid, napropamide, dalapon and propham. Efficient herbicides with negligible persistence in soil at the doses applied were evaluated on poppy plants in the field at various stages of growth. Small plants were severely injured by 2,4-D, killed rapidly by bromoxynil, ioxynil, paraquat (in mixture + diquat), and more slowly by glyphosate and metribuzin. The resistance to herbicides increased with the age of the poppy plant. Severe damage with partial kill of developed plants was obtained with bromoxynil, ioxynil, glyphosate, and paraquat + diquat; the last treatment produced the fastest effect.

Drug and Narcotic Control↗