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Biomedical subjects

A Ron

Publications and source records attributed to A Ron.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1980

Surgical day care: a review of 5,427 cases.

A surgical day care unit was established at the Kaplan Hospital, Rehovot, in 1975. This study includes 5,427 patients who underwent ear, nose and throat, gynecologic, eye and plastic surgery as well as other surgical procedures in the unit. The organization and staffing of the unit are also described. The feasibility of performing minor to intermediate surgical procedures requiring general anesthesia on a day basis is demonstrated. The experience gained shows that high medical standards are achieved with low resource expenditure. The cost per patient is significantly reduced. Absenteeism from school and word due to disability during long waiting times and hospitalization is decreased. There is less demand for hospital beds and the risk of cross infection is reduced. The psychological trauma of hospitalization, particularly in children, is reduced, and the waiting period for surgical intervention is much shorter.

Ambulatory Surgical Procedures↗
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↗
PubMed1977

Qualitative and quantitative studies on DNA and RNA synthesis in Loxodes striatus nuclei.

In this study the characteristics of the synthesis of DNA and RNA in the nuclei of Loxodes were investigated. Loxodes striatus is a primitive ciliate with 2 pairs of structurally differentiated diploid nuclei, the macro- and micronuclei. The macronuclei and differentiated morphologically into a clearly recoginzable central core and an outer zone. To determine DNA and RNA synthesis, individual organisms were analyzed by autoradiography after incubating groups of cells with a 3H-labeled precursor ([3H]thymidine for DNA and [3H]uridine for RNA). The following observations were made: (A) All portions of macro- and micronuclei appeared to contain DNA as judged by the localizations of incorporated [3H]thymidine. (B) The macro- and micronuclei did not synthesize DNA at the same time; moreover, the duration of DNA synthesis in the former was much longer than of the latter nucleus. (C) Replication of DNA in the inner core and outer zone of the macronucleus occurred at separate times with little if any overlap. (D) All of the detectable [3H]uridine incorporation was found in the macronucleus and none in the micronucleus. Within the macronucleus the central core was more heavily labeled. (E) The quantitative differences in the label of the different components synthesis can occur in adult macronuclei. The possible explantion of these results is discussed in the context of the nuclear evolution of ciliates and of recent information on nuclear differentiation.

Animals↗
PubMed1976

Fractionation of RNA from tetahymena by affinity chromatography on poly-U-Sepharose.

Exponential growing Tetrahymena pyriformis organisms were labelled with (3H) uridine or (3H) adenosine. The labelled RNA was extracted and isolated by affinity chromatography on poly-uridylic-acid sepharose and further analysed by means of sucrose gradient centrifugation and RNase digestion. Experimental evidence proved the existence of RNase resistant poly adenylic-acid fragments in the RNA of Tetrahymena cells. This poly adenylic-acid segment has a sedimentation rate of 4-5 S and would be localised in the 10-12S region of the RNA which is probably the m-RNA.

Animals↗
PubMed1976

Cytoplasmic DNA synthesis by cord blood cells of premature and full-term infants: an autoradiographic study.

Cord blood cells from 8 full-term and 12 premature infants as well as blood leukocytes from 10 adults were incubated with 3H-thymidine and were subsequently exposed to autoradiographic emulsion for prolonged periods of 45 and 90 days. Cytoplasmic label -- which were interpreted as evidence of mitochondrial DNA synthesis -- was found in 1.7 per cent of lymphoid cells from adult blood, in 2.9 per cent and 4.5 per cent of lymphoid cells from full-term and premature infants, respectively. Statistical analysis of the data shows that the number of labelled cells is significantly larger in the blood of premature infants than in adults (p less than 0.01).

Adult↗