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Biomedical subjects

A Ron

Publications and source records attributed to A Ron.

At least 19 recordsLinked to original sources
PubMed1989

The influence of an infectious disease specialist on the antimicrobial budget of a community teaching hospital.

After an infectious disease specialist (IDS) was introduced into a community teaching hospital, the use of antibiotics in eight of the main hospital departments was considerably reduced. The average daily expenditure on antibiotics before the IDS was appointed (April-June 1984) was $5.6. This was reduced in the last quarter of the study (April-June 1986) to $1.6. A drastic change, from $7.6 to $2.0, was noted in the surgical departments, due mainly to a strict policy in the prophylactic use of antibiotics. The success of the IDS was achieved by a combination of educational programmes, co-operation of the microbiology laboratory and the hospital pharmacy as well as by limiting restrictions to an extent that maintained clinical efficacy and the goodwill of those concerned.

Anti-Bacterial Agents↗
PubMed1989

AIDS in New York City: the role of intravenous drug users.

The key to the future of the HIV epidemic is the intravenous drug user. In New York City the future has arrived--intravenous drug use is now the predominant risk factor among new cases of AIDS. Our limited knowledge of most facets of drug abuse prevention and treatment and the emotional polarity and politicalization of the issues surrounding AIDS have made control of its spread among intravenous drug users very difficult. Clearly new research efforts are needed better to decide how to reduce the further spread of HIV infection among this group. But efforts to stop the spread cannot await these results. Intense and immediate efforts should focus on five areas for potential control of the spread of HIV infection among drug users: education, treatment on demand, expanding support services, providing sterile equipment, and readjustment of some of society's moral judgments that currently block action. Let us hope that in 10 years we do not look back and realize that we did too little too late while it was still possible to make a difference.

Acquired Immunodeficiency Syndrome↗
PubMed1989

The therapeutic efficacy of critical care units. Identifying subgroups of patients who benefit.

The majority of patients are admitted to critical care units for observation and to facilitate intervention if deterioration occurs or complications develop. We attempted to determine if a reduction in mortality in a subgroup of these patients admitted directly to the critical care units could be identified. A new method using the scientific principles of a randomized trial applied to the case-control design was employed. All 1905 patients admitted to the medical service over a three-month period were prospectively evaluated for illness severity and stability. Patients who would not have been eligible for a randomized clinical trial were excluded. Based on the prospective evaluations, four prognostically distinct subgroups of patients were formed. An odds ratio for each of the prognostic groups was calculated, a ratio of greater than 1 indicating a protective effect of direct critical care admission. Only one subgroup of patients, the unstable moderately ill, had an odds ratio greater than 1 (13.3). These results, in association with the results of our previous study, suggest that at the time of admission to the hospital, direct admission to the critical care unit reduced mortality among the unstable moderately ill subgroup of patients.

Epidemiologic Methods↗
PubMed1988

Sheep bronchoalveolar carcinoma: tissue associated protein complex (TAPC) in normal lung tissue and in the tumor differed quantitatively.

Sheep lungs experimentally and naturally affected by bronchoalveolar carcinoma were washed out exhaustively of soluble components by phosphate-buffered saline, pH 7.4 (PBS), followed by glycine buffer, pH 2.8 (GB), and then again by 1M KCl followed by PBS. The tissue matrix (TM) of the tumor-free region and the tumor-affected tissue were analysed separately by sodium dodecyl sulfate (SDS) polyacrylamide electrophoresis. Normal lung tissues obtained from normal sheep served as controls. Several protein fractions and fragments, identified in both the normal and the tumorous lung, have the molecular weight (MW) of 130,000-228,000, as compared with the major soluble tissue associated protein having MW of 70,000. Coomassie blue staining used in the SDS polyacrylamide system and alkaline phosphatase immunoreaction used in the Enzyme Linked Immunosorbant Assay (ELISA) showed tenfold increased concentration of the TAPC in the TM of the tumor tissue and in the blood of tumor-affected animals, respectively. Total concentration of the TAPC in the serum of tumor-affected animals was higher than in the normal. Immunofluorescent antibody test (IAT) detected the TAPC in the cytoplasm of tumor as well as in normal lung cells, and the study suggested that the TAPC reaches the peripheral blood during tissue destruction occurring at the tumor site, as observed by light and electron microscopy (LM and EM). The concentration of each of the TAPC fractions was higher in the tumor-affected sheep lung as compared with normal sheep lung. Antibodies prepared against the TAPC fractions were toxic to sheep lung cells in tissue culture. Tumor cells were more susceptible.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1987

The effect of estradiol valerate and allylestrenol on endometrial transformation in hypergonadotropic hypogonadic women.

The effect of estradiol valerate and allylestrenol on the endometrial transformation of five hypergonadotropic hypogonadic women was evaluated. Estradiol valerate was administered throughout the whole induced cycle (28 days), while allylestrenol was added during the second half of the cycle. Endometrial biopsies were performed during allylestrenol treatment and were evaluated histologically. Samples of endometrium were also subjected to one-dimensional SDS electrophoresis. Of ten biopsies performed, only one was interpreted to be in-phase, while the others were dated proliferative (4 biopsies) or showed abortive or out-of-phase secretory transformation. The highest mean serum progesterone level, detected under allylestrenol treatment, was 1.5 ng/ml. Protein electrophoresis demonstrated relative sequential changes in the protein patterns of the 115 kDa and 150 kDa protein bands. It is concluded that allylestrenol, although having gestagen properties, may not be efficient for the induction of an adequate secretory transformation of human endometrium in the absence of ovaries.

Adult↗
PubMed1987

Stress proteins in the human endometrium and decidua.

Protein synthesis in response to heat shock was induced in the proliferative and secretory human endometrium as well as in human decidua during a 2-h incubation period at 41 degrees C. A major 70 K stress protein and two minor stress proteins of 88 and 94 K were detected after [35S]methionine incorporation followed by SDS polyacrylamide gel electrophoretic separation and autoradiography of dried gels. Two dimensional isoelectric focusing followed by fluorography showed the major 70 K stress protein to consist of at least six polypeptides of pH 4.6 to 5.5, the 88 K to consist of at least four polypeptides, of pH 5.5 to 6.0, and the 94 K to consist of at least three polypeptides of pH 4.6 to 5.2. Stress proteins in the human endometrium and decidua may prove to be of physiological significance in reproductive events.

Decidua↗
PubMed1986

Effect of depletion of phosphate and bicarbonate ions on insulin action in rat adipocytes.

The effect of insulin on rat adipocytes was studied in isotonic buffers (pH 7.4) containing NaCl, CaCl2, MgSO4, KCl, and bovine serum albumin but no phosphate or bicarbonate anions. In phosphate- and bicarbonate-free buffers the dose-response curve to insulin is shifted to the right, the effects of the hormone on hexose uptake, glucose metabolism, and inhibition of lipolysis being observed at much higher (nearly 2 orders of magnitude) concentrations of insulin. The insulin binding capacity of the cells is only slightly changed. The dose-response curve for isoproterenol which stimulates lipolysis in the same cell type is almost the same in both Krebs-Ringer bicarbonate buffer and phosphate- and bicarbonate-free buffers. The dose-response curves for agents that mimic the action of insulin such as wheat germ agglutinin or vanadate ions are also shifted to the right. The dose-response curve to insulin can be returned to "normal" by readdition of either bicarbonate or phosphate. Almost complete recovery is obtained at either 10 mM bicarbonate or 24 mM phosphate, respectively. External Ca2+ ions which are not required for the proper action of insulin in fat cells maintained in Krebs-Ringer bicarbonate buffer, become essential for insulin action in bicarbonate-free buffer. The study indicates that depletion of bicarbonate and, to a lesser extent, phosphate anions, interferes with an essential insulin-dependent post-binding event. Also, in bicarbonate-free medium, external Ca2+ ions are essential for insulin-mediated processes. The implications of this study to the mode of action of insulin, and to physiological and clinical states of insulin desensitization are discussed.

3-O-Methylglucose↗
PubMed1986

Effect of depletion of bicarbonate or phosphate ions on insulin action in rat adipocytes. Further characterization of the receptor-effector system.

In the preceding paper (Shechter, Y., and Ron, A. (1986) J. Biol. Chem. 261, 14945-14950) we have shown that in fat cells, prepared and maintained in an isotonic buffer (pH 7.4) containing neither phosphate nor bicarbonate anions (Buffer A), the dose-response curve to insulin shifted to the right by about 2 logarithms and insulin binding affinity or capacity was only slightly decreased. In the current paper we demonstrate that progressive loss of insulin binding, either by treatment with trypsin or preincubating the cells with isoproterenol, correlates well with the reduced ability of the cells to elicit maximal lipogenesis in response to insulin. We further demonstrate in the "new" system that: the dissociation of labeled insulin from fat cells is not accelerated by the inclusion of unlabeled insulin in the medium; termination of lipogenesis in Buffer A occurs immediately; ligand-induced receptor internalization is grossly defective; and insulin is unable to stimulate lipogenesis at 15 degrees C. The data support the hypothesis that in the new experimental system all measurable binding sites are linked to a coupling mechanism. Each site behaves as an independent, separate entity and there are no site to site interactions. This leads to a linear relationship between binding and bioactivation, lack of negative or positive cooperatively, accelerated rate of termination, defective internalization, a shift to the right in the dose-response curve to insulin, and a lack of insulin response at a lower temperature. In more general terms, the study indicates that all measurable insulin receptors are chemically homogeneous in their potential capability to be coupled to an insulin effector (biologically relevant) system, and they do so under particular experimental conditions.

Adipose Tissue↗
PubMed1985

Use of medical care by children during a physicians' strike.

From March through June 1983 the almost 8,000 physicians in the public sector in Israel were on strike. While emergency hospital care was assured, primary care options were severely limited, and the Alternative Medical Service set up by the Israel Medical Association involved a significant payment at the time of visit. This constituted a radical change from the no-charge physician care regularly provided to the insured population in the community clinics. A study was conducted in the third month of the strike to assess the utilization of care for children. The results of interviews with 253 families registered in eight Sick Fund clinics showed that the majority of parents who reported a child's illness did not defer seeking care. The first sources of care were the nurses in the community clinic and the hospital emergency room, while care from physicians working privately was used to the same extent as the Alternative Medical Centers. These results indicate that the relatively high utilization patterns of this population were not significantly changed. Differences in the first source of care by clinic suggest that socioeconomic factors and the availability of the various options are related to use in each area. These factors, as well as the threshold for seeking care and the influence of selection, should be examined in more detail to develop appropriate utilization patterns and a more rational use of resources.

Adolescent↗
PubMed1985

Expression of a cell surface immobilization antigen during serotype transformation in Tetrahymena thermophila.

A temperature shift from 40 to 28 degrees C rapidly induced expression of a specific immobilization antigen at the cell surface in Tetrahymena thermophila. This transformation was inhibited by actinomycin D and cycloheximide but not by colchicine or cytochalasin B. The major surface antigen expressed at 28 degrees C in cells homozygous for the SerH3 allele was partially purified, and an antiserum against this preparation was raised in rabbits. Electrophoresis, immunoblot, and [35S]methionine incorporation studies are reported which support the conclusion that the H3 antigen is an acidic protein with an Mr of approximately 52,000 daltons. An induced synthesis of the H3 immobilization antigen was detected within 30 min after a shift from 40 to 28 degrees C. This protein appeared to be synthesized in the microsomal fraction and transferred without cleavage to the cell surface, where it was inserted first into nonciliated regions.

Animals↗
PubMed1985

The "key-form" system for data collection in disability evaluation.

A new system for comprehensive disability evaluation has been developed in the framework of our Hospital. This system is based on multidisciplinary evaluation during one day of tests and the summarization of the data collected. The process takes place at the Institute for Functional Evaluation, a joint project of the National Insurance Institute and the Loewenstein Hospital in Israel. The process was designed to provide the basis for the determination of the degree of disability according to the requirements of the General Disability Law. In order to carry out the experimental program a computerized system of recording was created. The method of recording is based upon the "Key-form" where the different systems of the body appear one after the other and next to them the term "normal" or "abnormal". In the case of an abnormal mark, the tester goes on to the next stage which involves completion of a detailed form for that system. The forms are coded for the transfer of information to the computer without intermediary stages and this enables processing of a vast amount of data with relative ease. The system enables compilation of individual profiles and statistical tables and analysis. Theoretical and practical applications of the system are discussed on the basis of the pilot study.

Data Collection↗
PubMed1985

Ambulatory care of the aged in Kupat Holim clinics.

The use of ambulatory services by the elderly was studied, using data recorded on a daily diary in primary care practices. The number and content of visits to primary care practices in Kupat Holim (Health Insurance Institute of the General Federation of Labor) community clinics in the Sharon and Tel Aviv regions is presented. The rates of use by the total adult population and by those greater than or equal to 65 years old treated by the same physicians are compared for the two regions. As expected, the elderly have the higher visit rates, with 8.4 annual visits as compared with 5.1 for the total adult population in the Sharon region clinics. For Tel Aviv practices, there were 11.7 and 6.8 visits, respectively. The proportion of visits by the elderly in the daily load is around 60% greater than is their proportion in the patient populations. These data do not permit any qualitative analysis, but have implications for the planning, staffing and management of ambulatory care for the elderly.

Adult↗
PubMed1984

Effects of interferon and encephalomyocarditis virus on in vitro development of preimplantation mouse embryos with and without the zona pellucida.

Development of preimplantation mouse embryos, with or without the zona pellucida, in the presence of interferon (IFN) and mouse encephalomyocarditis (EMC) virus was studied using the in vitro culture method. The embryos (2- to 8-cell stages) were obtained from superovulated mice and cultured in modified Witten's medium under paraffin oil in 5% CO2 in air at 37 degrees C. Removal of the zona pellucida does not affect the subsequent development of the embryos: 90% of embryos with and 87% of embryos without the zona pellucida reached the morula-early blastocyst stages. Mouse IFN (10(4) units/ml) had no inhibitory effect on the developmental ability of the preimplantation embryos with or without the zona pellucida: 88 and 89% of the embryos in each group, respectively, reached the morula-early blastocyst stages. The preimplantation mouse embryos were sensitive to the embryotoxic effect of EMC virus: at a multiplicity of 20 infection particles per embryo the development of 43% of embryos was inhibited. The zona pellucida had no significant protective effect: Its removal changed only slightly the susceptibility of the preimplantation embryos to this virus. Pretreatment of embryos with IFN did not protect them from the embryotoxic effect of EMC virus. This work indicates that preimplantation mouse embryos appear to be resistant for both the antiviral and antiproliferative activities of IFN.

Animals↗
PubMed1984

'Stress-proteins' are induced in Tetrahymena pyriformis by histidinol but not in mammalian (L-929) cells.

This study compares the influence of histidinol, a reversible inhibitor of growth and protein synthesis, on patterns of proteins synthesis in Tetrahymena pyriformis and cultured mouse L cells. In Tetrahymena, histidinol (10 mM) reduced total cell protein synthesis by over 60%. Analysis of individual protein bands by SDS-PAGE showed that at least 17 bands became less prominent, while 13 polypeptides became more prominent, during exposure to histidinol. These effects were rapidly reversed by addition of equivalent concentrations of histidine. Actinomycin D (actD) prevented the enhancement of most of the histidinol-'stimulated' bands, suggesting control at the transcriptional level. The majority of the histidinol-'stimulated' polypeptides appeared to be the same as corresponding heat-shock polypeptides, although some polypeptides were 'stimulated' by histidinol and not by heat shock, while others were 'stimulated' by heat shock and not by histidinol. 'Stimulation', both by histidinol and by heat shock, may reflect selective retention rather than induced synthesis of some or all of the relevant polypeptides. In contrast to Tetrahymena, cultured mouse L cells did not alter their normal polypeptide pattern under the influence of histidinol, under conditions in which total protein synthesis was depressed to a similar degree. It is possible that 'stress' proteins might be formed or retained in order to mediate adaptive responses of free-living cells to environmental changes.

Animals↗
PubMed1979

Evaluation of hypertension control in general practice.

A review of the medical charts of 17 general practitioners in six family clinics in Tel Aviv showed that a blood pressure reading was recorded for 69.3% of the adult patients. Elevated values--greater than or equal to 160 (systolic) and/or greater than or equal to 95 (diastolic) mm Hg--were seen in 26.1% of the patients with recorded blood pressure readings. Antihypertensive medications were presecribed for 74.5% of those with elevated blood pressure. In two thirds of the treated group, blood pressure had been measured only once or twice before the initiation of therapy. Of the treated patients, 30% seem to have stopped therapy on their own initiative. Treatment was discontinued by the physician in 18%. Of the 52% who remained on treatment, only one third had a normal systolic or diastolic pressure on the last reading. The failure to reduce blood pressure in the other two thirds may be due, at least in part, to the use of methyldopa and reserpine without a diuretic.

Adult↗