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Biomedical subjects

M Weiner

Publications and source records attributed to M Weiner.

At least 271 records · Page 15Linked to original sources
PubMedDate not supplied

Computer analysis of factors influencing frequency of infection in systemic lupus erythematosus.

Data from a prospective study of the clinical course in 223 patients with systemic lupus erythematosus followed for 655 patient-years were analyzed by computer to determine the influence on frequency of infection of 1) corticosteroid dose; 2) azathioprine; 3) active disease, measured by new disease exacerbations, elevated ESR, hypocomplementemia, active urinary sediment, and proteinuria; 4) uremia; and 5) leukopenia. The frequency of all infections, and of bacterial and opportunistic infections specifically, increased progressively with increasing steroid dose. Azathioprine use, independent of steroid dose, did not account for an increased risk of bacterial, opportunistic, or nonspecific viral infections. Leukopenia did not predispose to infection, except possibly when associated with azathioprine-induced bone marrow suppression. Active renal disease, especially when manifested by abnormal urine sediment, was associated with an increase in infection frequency.

Azathioprine↗
PubMedDate not supplied

Modification of age-induced changes in heme and hemoproteins by testosterone in male rats.

Age-related changes in heme and hemoproteins, as well as the effect of testosterone treatment on these modifications were examined in male Sprague-Dawley rats. The activity of delta-aminolevulinic acid synthase (ALA-S) and the microsomal concentration of heme in aged rats were decreased by 37% and 33%, respectively, as compared to young values. In contrast, a marked increase in the activity of microsomal heme oxygenase (MHO) was seen in these animals. In aged rats, the level of cytochrome P-450 was decreased by 37%, as compared to young values. Furthermore, the activities of benzo[a]pyrene hydroxylase and aniline hydroxylase were decreased in proportion to the microsomal content of cytocyrome P-450. Steroid delta 4-hydrogenase, an index of endogenous substrate metabolism, exhibited no changes in activity during the aging process. The level of various hemoproteins such as cytochrome b5 and tryptophan pyrrolase in aged animals remained unaltered despite the decreased hepatic concentration of heme. It is worth noting that testosterone treatment of aged castrated rats restored the level of heme and cytochrome P-450 and the altered enzymatic activities of ALA-S and MHO to the "young" condition. In view of these findings, it is concluded that the events which lead to the low level of heme and cytochrome P-450 and its dependent mixed function oxidase activity during the senescent period could be due to increased rates of MHO and diminished ALA-S activities in these animals.

Aging↗
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The influence of infusion rate on the acute intravenous toxicity of phytic acid, a calcium-binding agent.

The intravenous toxicity of phytic acid (inositol hexakisphosphate, IHP) has recently become of interest because of the potential for IHP incorporation into red blood cells to achieve a therapeutically useful shift in the hemoglobin-oxygen dissociation curve (Gersonde, K. and Nicolau, C., Blut, 39 (1979) 1). The observed acute intravenous toxicity of IHP in rodents is consistent with its recognized capacity to bind calcium. The toxic manifestations of intravenous IHP are a function of rate of infusion as well as total dose, with some seemingly anomalous variations which may related to compensatory mechanisms. The data suggest that significant alterations of plasma calcium and the toxic potential of such alterations are not likely to result from the administration of red blood cells with IHP incorporated.

Animals↗
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The in vivo survival of human red cells with low oxygen affinity prepared by the osmotic pulse method of inositol hexaphosphate incorporation.

The purpose of this study was to determine the posttransfusion survival of low-affinity red cells (RBCs) containing the hemoglobin modifier, inositol hexaphosphate (IHP). An osmotic pulse technique was used to incorporate IHP, a compound that normally does not cross the RBC membrane. Two groups of six volunteers were studied. RBCs were treated under conditions that resulted in a relatively large increase in mean corpuscular volume (delta MCV = 11.8 +/- 4.0, 1 SD) in Group I, but a relatively small increase (delta MCV = 5.5 +/- 1.9) in Group II. The groups had a similar decrease in mean corpuscular hemoglobin (delta MCH = -3.8 +/- 0.9 for Group I and -3.1 +/- 1.1 for Group II). The 24-hour posttransfusion RBC survival, measured with 3 mL of 51Cr-labeled autologous RBCs, correlated with the induced change in oxygen affinity, and larger shifts were associated with poorer survival. An acceptable 75-percent 24-hour posttransfusion survival was achieved for p50 increases up to approximately 15 torr. Cells that survived 24 hours appeared to have a normal lifespan. This study is the first demonstration of adequate survival for human RBCs with a potentially long-lasting decrease in oxygen affinity.

Blood Transfusion↗
PubMedDate not supplied

Contrasting views of physicians and nurses about an inpatient computer-based provider order-entry system.

OBJECTIVE: Many hospitals are investing in computer-based provider order-entry (POE) systems, and providers' evaluations have proved important for the success of the systems. The authors assessed how physicians and nurses viewed the effects of one modified commercial POE system on time spent patients, resource utilization, errors with orders, and overall quality of care. DESIGN: Survey. MEASUREMENTS: Opinions of 271 POE users on medicine wards of an urban teaching hospital: 96 medical house officers, 49 attending physicians, 19 clinical fellows with heavy inpatient loads, and 107 nurses. RESULTS: Responses were received from 85 percent of the sample. Most physicians and nurses agreed that orders were executed faster under POE. About 30 percent of house officers and attendings or fellows, compared with 56 percent of nurses, reported improvement in overall quality of care with POE. Forty-four percent of house officers and 34 percent of attendings/fellows reported that their time with patients decreased, whereas 56 percent of nurses indicated that their time with patients increased (P < 0.001). Sixty percent of house officers and 41 percent of attendings/fellows indicated that order errors increased, whereas 69 percent of nurses indicated a decrease or no change in errors. Although most nurses reported no change in the frequency of ordering tests and medications with POE, 61 percent of house officers reported an increased frequency. CONCLUSION: Physicians and nurses had markedly different views about effects of a POE system on patient care, highlighting the need to consider both perspectives when assessing the impact of POE. With this POE system, most nurses saw beneficial effects, whereas many physicians saw negative effects.

Attitude to Computers↗
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Psychological reactions to continuous ambulatory peritoneal dialysis.

The first twenty patients who entered our continuous ambulatory peritoneal dialysis (CAPD) program from March, 1979 to February, 1981 were interviewed to assess their psychological reactions to CAPD. Six patients were successfully maintained on CAPD for more than one year. CAPD provided patients with a greater sense of well-being, strength, and independence. This independence required adherence to a strict schedule of exchanges. Reactions to the loss of CAPD followed the pattern of a grief reaction. Those patients who were self-disciplined and comfortable assuming active control of their health care proved to be the best candidates for CAPD.

Adult↗
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Comparative prescription practices of family practice, internal medicine, and pediatrics residents.

The purpose of this study was to compare the prescribing practices among family practice, pediatric, and internal medicine third-year residents in an inner city ambulatory care setting. A four-month chart audit was made for the prescriptions provided for asthma, osteoarthritis, congestive heart failure, and upper respiratory infection patients by these residents. In general, family physicians prescribed medications that were not different from those used by internists and pediatricians. However, there were significant (p less than 0.01) differences in the number of visits and prescriptions among the specialties. The prescribing practices of the study group differed from a national survey of private practitioners in several drug categories.

Drug Prescriptions↗
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Inhibition of glucuronidation and sulfation by dibutyryl cyclic AMP in isolated rat hepatocytes.

Dibutyryl cyclic adenosine 3':5'-monophosphate (DBcAMP) has been reported to cause numerous alterations in the activity of hepatic monooxygenase enzymes following in vivo administration or in vitro addition to intact liver preparations. In the present report the effect of the nucleotide on metabolism of p-nitroanisole (pNA) and aniline was studied in isolated rat hepatocytes. Initial studies indicated that in vitro addition of DBcAMP to hepatocytes increased metabolism of both pNA and aniline as determined by the production of oxidized metabolites, p-nitrophenol (pNP) and p-aminophenol, respectively. After enzymatic hydrolysis with beta-glucuronidase and arylsulfatase, it was determined that DBcAMP had increased accumulation of pNP formed from pNA by inhibiting further metabolism via conjugation reactions. Further studies using pNP directly as substrate confirmed the finding and revealed that glucuronidation was more sensitive to the inhibitory effect of DBcAMP than was sulfation. The 8-bromo derivative of cAMP was more potent than DBcAMP at inhibiting glucuronidation, whereas cyclic AMP and dibutyryl cyclic guanosine 3':5'-monophosphate were without effect. Noncyclic adenine nucleotides (ATP, ADP, AMP) also altered pNA and pNP metabolism. ATP and ADP increased pNP accumulation from pNA while ATP and AMP inhibited glucuronidation of pNP. DBcAMP was further found to decrease UDP-glucuronic acid levels in a concentration-dependent manner without disrupting the redox state (NAD+/NADH) in hepatocytes. The data suggest that adenine nucleotides exert a nonspecific inhibition upon glucuronidation and sulfation reactions.

Adenine Nucleotides↗
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A profile of the urban family.

Very little research work has detailed the structure and function of inner city families. A retrospective demographic analysis of three distinct New York City community districts shows a broad spectrum of living arrangements within the city as well as within separate census tracts. Urban family physicians should be aware of these trends in order to improve their delivery of care and their understanding of family dynamics.

Delivery of Health Care↗
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Inhibition of hepatic drug metabolism in VX2 carcinoma-bearing rabbits.

Hepatic metabolism of aniline, p-chloro-N-methylaniline, and aminopyrine was determined in control male, New Zealand White rabbits or those bearing VX2 carcinoma (a prostaglandin-secreting tumor). In addition, the levels of cyclic AMP and cyclic GMP in the liver and the concentration of calcium in serum were examined. After 13 days of tumor growth, metabolism of aminopyrine and PCMA was decreased by approximately 30%, whereas aniline metabolism was not significantly altered. Metabolism of all substrates was significantly depressed to 20-60% of control by 22 days after transplantation. Serum calcium levels increased by 14 and 29% after 13 and 22 days, respectively. The ratio of cyclic AMP to cyclic GMP was 156% of control after 13 days and 139% by 22 days of tumor growth. The increased ratio was due solely to a change in cyclic AMP concentration. A 20-min pretreatment with prostaglandin E1, 0.3 mg/kg ip, depressed in vitro hepatic metabolism of all substrates by 27-56% while increasing cyclic AMP levels by 42%.

Aminopyrine↗
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Metabolism of p-nitroanisole and aniline in isolated hepatocytes of streptozotocin-diabetic rats.

The metabolism of p-nitroanisole and aniline was studied in isolated hepatocytes of male and female rats rendered diabetic with streptozotocin. In cells of male diabetic rats the production of the oxidized metabolites of both substrates was decreased relative to cells of control rats. In contrast, enzyme activity toward both substrates was increased when isolated microsomes of diabetic males were studied. Cytochrome P-450 content was increased in hepatocytes and microsomes of these animals. Treatment of diabetic male rats with insulin returned drug disposition and cytochrome P-450 in hepatocytes to control levels. In females, production of oxidized metabolites in hepatocytes as well as mono-oxygenase activities in microsomes were increased by diabetes, whereas cytochrome P-450 levels were not significantly altered in hepatocytes or microsomes. The results indicate that the effect of diabetes on drug metabolism observed in microsomal preparations may not accurately reflect the pattern of drug disposition in the whole cell. The pattern may ultimately be determined by other factors within the hepatocytes which are altered in the diabetic condition. Such factors may be responsible for the sex-dependent effects of streptozotocin diabetes on drug metabolism in rat hepatocytes.

Aniline Compounds↗
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Intracerebral hemorrhage caused by cerebral amyloid angiopathy: radiographic-pathologic correlation.

Seven cases of nontraumatic intracerebral hemorrhage due to histologically confirmed cerebral amyloid angiopathy were observed over a period of 2 1/2 years. Initial computed tomographic (CT) scans demonstrated lobar hemorrhages in all but one patient, who had presented with corpus callosum hemorrhage. Superficial location, irregular borders, and surrounding edema were characteristic features. Angiography was performed in three cases. Findings included mass effect (three cases), opercular branch occlusion (one case), and pericallosal irregularity (one case), all in the areas of the hemorrhage. Clinically, none of the patients had a history of prior cerebrovascular disease. Mild hypertension had been present in three patients and dementia in two. These findings suggest that cerebral amyloid angiopathy is not a rare cause of atraumatic lobar hemorrhage, particularly in a normotensive, elderly population.

Aged↗