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Biomedical subjects

M Ron

Publications and source records attributed to M Ron.

At least 109 records · Page 6Linked to original sources
PubMed1986

Sire and maternal grandsire effects on calving difficulty and calf mortality in Israeli Holsteins.

Associations among sire and maternal grandsire evaluations for calving difficulty and calf mortality were investigated in the Israeli Holstein population. Primiparous and multiparous calvings were analysed separately. Genetic correlations between calving difficulty and calf mortality were close to unity for primiparous calvings but lower for multiparous calvings. Genetic correlations between primiparous and multiparous sire evaluations were .94 and .72 for calving difficulty and calf mortality. Genetic correlations between sire and maternal grandsire evaluations were .6 for primiparous calvings and not-significant for multiparous calvings for both traits. These results correspond to findings that the direct genetic effect is larger than the maternal effect but that there is a slight negative correlation between them. We suggest that sire evaluations for calving difficulty of multiparous cows be used as a preliminary prediction of heifer calving difficulty and calf mortality and that the separate calving trait evaluations be combined into an overall calving selection index.

Animals↗
PubMed1985

Associations among milk yield, yield persistency, conception, and culling of Israeli Holstein dairy cattle.

Genetic correlations among Predicted Differences for milk yield corrected for economic value of fat content, annualized yield, yield persistency, conception rate, and culling rate were estimated. Correlations were .43 between yield persistency and annualized yield, .42 between yield persistency and conception rate, and .1 between annualized yield and conception rate. For Predicted Differences for these traits computed separately for each of first three parities, correlations between pairs were highest for annualized yield and lowest for culling rate. Regression coefficients for conception rate from cow insemination records on daily yield preceding insemination and on absolute change of yield during month of insemination were significantly negative for the first three parities. A positive pleiotropic effect for yield, yield persistency, and conception rate was suggested; therefore, progeny testing for yield persistency may improve yield and conception rate. High yields and large changes of yield during month of insemination adversely affected conception rate of cows within herds.

Animals↗
PubMed1984

Transfer of 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 across the perfused human placenta.

The rates of placental transfer of 25-hydroxyvitamin D3 [25-(OH)D3] and 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] were determined in an in vitro perfusion system. Antipyrine was included in each perfusion, and the data are expressed as clearance index, the ratio of hydroxyvitamin D3 to antipyrine clearance. In most experiments, serum, 0.2%, was added to the perfusates as a source of vitamin D3-binding protein. Binding as measured by dextran-coated charcoal assay for 25-(OH)D3 was over 90%, for 1,25-(OH)2D3, only 25% to 50%. The clearance index from the maternal to fetal circulation averaged 0.02 and 0.26 for 25-(OH)D3 and 1,25-(OH)2D3, respectively. When vitamin D3-binding protein was omitted from the perfusate, the clearance indices of 25-(OH)D3 were 0.12 and 0.46 in two experiments. Binding to vitamin D3-binding protein is a major determining factor for the transfer rates of 25-(OH)D3 and 1,25-(OH)2D3.

Antipyrine↗
PubMed1984

Maternal blood pressure response to the intravenous administration of pethidine-promethazine during labor.

A double blind study on the effect of an intravenous injection of a combination of 75 mg pethidine and 25 mg promethazine was conducted on 200 women during normal deliveries. Four groups of 50 women each received injections of pethidine and promethazine, promethazine alone, pethidine alone and normal saline. In the pethidine-promethazine group there was a significant elevation in blood pressure in the first 10 min following the injection as compared with the other groups. The mean (+/- S.D.) systolic blood pressure after the injection was 143.2 +/- 14.3 mmHg as compared with 118.9 +/- 8.4 mmHg before the injection, and the mean diastolic blood pressure as 96.9 +/- 8.4 mmHg after the injection as compared with 77.7 +/- 9.3 mmHg before the injection. 25 mg promethazine alone caused slight elevation in blood pressure which was further increased by combination with pethidine. The clinical significance of these observations is discussed.

Blood Pressure↗
PubMed1984

Computed axial brain tomography in long-term benzodiazepine users.

Twenty patients who had taken long-term benzodiazepines were submitted to brain CT scan examinations. Some scans appeared abnormal. The mean ventricular/brain area measured by planimetry was increased over mean values in an age- and sex-matched group of control subjects but was less than that in a group of alcoholics. There was no significant relationship between CT scan appearances and the duration of benzodiazepine therapy. The clinical significance of the findings is unclear.

Adult↗
PubMed1984

Growth characteristics of human first trimester decidual cells cultured in serum-free medium: production of prolactin, prostaglandins and fibronectin.

A procedure for the establishment of pure human first trimester decidual cells in primary cultures has been developed. The high rate of success in obtaining such cultures resulted from the elimination of fibroblasts by appropriate enzyme dissociation and filtration of the initial tissue sample, and subsequent maintenance of the cells in a serum-free medium supplemented with insulin, fibroblast growth factor (FGF), estradiol, progesterone, hydrocortisone, transferrin and sodium selenite. Under these culture conditions, we obtained pure and actively dividing decidual cells forming tightly packed and nonoverlapping epithelioid cell monolayers covering more than 75% of the culture area. The cultured decidual cells retained their in vivo capacity to produce prolactin and various prostaglandins (PGs), primarily PGE2. There was a marked reduction in hormone production after 20 days in culture. A massive network of fibrillar surface fibronectin was detected by indirect immunofluorescence staining of the cultured cells. The production of prolactin and PGs together with the secretion of fibronectin may play a role in the implantation and subsequent growth of the embryo. The described procedure of obtaining fibroblast-free decidual cell monolayers will promote studies on the hormonal regulation of this tissue at the time of early intrauterine life.

Cells, Cultured↗
PubMed1984

Maternal-fetal transfer of aminophylline.

Ten women with normal pregnancies who underwent an elective cesarean section received orally 200 mg of aminophylline every 6 hours for 24 - 36 hours prior to surgery. The levels of aminophylline and caffeine were measured in maternal and cord sera and in amniotic fluids. The mean level of aminophylline (+/- SD) in maternal serum was 10.4 +/- 1.74 micrograms/ml, and in cord serum 11.2 +/- 1.25 micrograms/ml. The mean aminophylline level in amniotic fluids was 8.2 +/- 1.42 micrograms/ml. The serum aminophylline levels were within the therapeutic level range. Caffeine levels in those specimens ranged between traces to 6 micrograms/ml which correspond to the normal dietary range.

Aminophylline↗
PubMed1984

Factors affecting conception rate of Israeli Holstein cattle.

Environmental and genetic effects on reproductive performance were estimated. Data included records of 194,579 inseminations of cows and 56,132 inseminations of heifers in 200 kibbutz herds from 1980 to 1981. Conception status was ascertained by veterinary palpation if no subsequent parturition was recorded. With subsequent parturition, the insemination closest to 277 days before parturition was considered successful. Largest differences in conception rate were between cows (40.4%) and heifers (64.3%) and among insemination month for cows (23.5 to 51.5%). Heritabilities of sire effect on conception rate were .016 for cows and .006 for heifers. Correlations between heifers and cows were .64 for inseminator and .54 for service sire. Low correlation between heifers and cows for herd effect (.17) indicates a management problem; low correlation between heifers and cows for sire effect (.27) suggests a different genetic mechanism for fertility. Significant improvement may be achieved in fertility by selection of service sires, sires, and inseminators if evaluations are based on a large number of observations. However, the major increase of conception rate may be expected from reducing adverse effects of summer conditions on reproductive performance.

Animals↗
PubMed1984

Increased placental concentrations of 25-hydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 in pregnant rats treated with human chorionic gonadotropin.

Pregnant rats were injected intrajugularly with 2500 i.u. human chorionic gonadotropin (HCG) toward the end of gestation (days 18-19) and 7.0 pmoles of tritiated 25-hydroxyvitamin D3 [( 3H]25(OH)D3) the following day. They were sacrificed ten to 24 hours later. [3H]25(OH)D3 and the in vivo produced [3H]24,25-dihydroxyvitamin D3 [( 3H]24,25(OH)2D3) in lipid extracts from maternal serum, kidneys, placenta and fetal tissues were separated by Sephadex LH-20 chromatography, and high performance liquid chromatography (HPLC). HCG treatment of pregnant rats increased significantly 25(OH)D3 levels in the placenta and kidneys and 24,25(OH)2D3 level in the placenta. Fetal metabolites levels were unaffected by HCG treatment. Serum and kidney levels of 25(OH)D3 and 24,25(OH)2D3 in pregnant rats were significantly lower than in non-pregnant rats. Serum and kidney levels of both metabolites in non-pregnant female rats treated with HCG did not differ from the untreated controls. HCG may, therefore, be involved in regulation of fetoplacental vitamin D metabolism.

Animals↗
PubMed1983

Vitamin D3 metabolites in rat epididymis: high 24,25-dihydroxy vitamin D3 levels in the cauda region.

Normal male rats received six subcutaneous injections of 8.0 pmoles of tritiated 25-hydroxy vitamin D3 ([3H]25(OH)D3) or one intrajugular injection of 8.0 pmoles of high specific radioactivity [3H]-25(OH)D3. Lipid extracts of several tissues including the reproductive organs were subjected to sephadex LH-20 chromatography to determine the tissue distribution of the injected material and of the in vivo produced dihydroxylated cholecalciferol metabolites. The nature of the putative 25(OH)D3 and the 24,25-dihydroxy vitamin D3 (24,25(OH)2D3) from epididymis tissue was confirmed by high performance liquid chromatography (HPLC). The epididymis levels of 24,25(OH)2D3 were considerably higher in the cauda epididymis compared to kidney and caput epididymis levels. The other metabolites levels in this tissue were similar to those determined in the kidneys. The amounts of the three metabolites found in all other tissues were well below the cauda epididymis or kidney levels. The findings suggest a possible physiological role for 24,25(OH)2D3 in the epididymis, and are also consistent with data of others which indicated a possible action of 1,25-dihydroxy vitamin D3 (1,25(OH)2D3) in rat reproductive tissues.

24,25-Dihydroxyvitamin D 3↗
PubMed1983

Serum levels of polychlorinated biphenyls and some organochlorine insecticides in women with recent and former missed abortions.

Polychlorinated biphenyls and some organochlorine insecticides (DDT isomers and their metabolites, lindane (gamma-BHC), dieldrin, heptachlor epoxide) were assessed in the serum of 17 women with recent missed abortions, 7 women who experienced one or several missed abortions in their past, and 7 women with normal, second trimester pregnancy. Fifty-three percent of the cases of recent missed abortion had PCB serum levels higher than the mean plus two standard deviations of the control group. The mean PCB serum level in women with recent missed abortion and relatively high PCB serum levels was significantly different from that of the control group (103.04 versus 20.69 ppb, P less than 0.001). The mean PCB serum level of the former missed abortions group was also significantly different from that of the control group (82.00 versus 20.69 ppb, P less than 0.001). The quantity of the higher chlorinated biphenyl homologues (penta- and hexachlorobiphenyls) was increased in the high PCB level, missed abortion group and in the former missed abortion group, while the lower chlorinated biphenyl homologues were decreased in these groups in comparison with the control group. The percentage of total o,p'-DDT serum level, as related to total DDT, showed an increase in the high PCB level, recent missed abortion and in the former missed abortion groups, in comparison with the control group (36.18 and 48.98 versus 25.57, respectively). The fact that the former missed abortion group showed increased PCB serum levels similar to those found in the high PCB level, recent missed abortion group confirms the existence of an association between relatively high PCB serum levels and the occurrence of missed abortion. The possible role of PCBs in the occurrence of missed abortion is discussed.

Abortion, Missed↗
PubMed1983

Maternal and fetal serum prolactin levels in cases of premature rupture of membranes.

Serum prolactin levels were measured in maternal and fetal sera immediately post delivery in 20 cases of premature rupture of the membranes and in 20 controls. Fetal serum prolactin levels were 781 +/- 265 ng/ml in cases of PRM and 737 +/- 314 ng/ml in controls. Maternal serum prolactin levels were 504 +/- 264 ng/ml in cases of PRM and 731 +/- 361 ng/ml in controls. This difference is statistically significant (t = 1.81, p less than 0.05). A probable role of prolactin in maintaining fetal membrane integrity and the probable effect of the difference in maternal serum prolactin concentration in the two groups on the membranes' viscoelastic properties is discussed.

Elasticity↗
PubMed1983

Associations among progeny tests of single or pooled lactations.

Genetic correlations between Predicted Difference for first and second, first and third, and second and third lactations milk were .82, .62, and .94 and for Predicted Difference percent fat .94 for the three associations. Regression coefficients for following on previous lactation Predicted Difference were less than unity; thus, Predicted Difference from first lactation might be overweighted when age adjusted and pooled with second and third lactations. Regressions of Predicted Difference milk of sons on sires for first, second, third, and pooled lactation records were .32 +/- 18, .42 +/- .21, .56 +/- .31, .35 +/- .15, and intraclass correlations between half brothers were .09 +/- .08, .28 +/- .11, .25 +/- .11, and .12 +/- 10. Predicted Differences for second and third lactations were, thus, near the theoretical expectation of .5 and .25 for regressions of son on sire and between half-brother correlations but lower for Predicted Differences of first and pooled lactations. Variance of Predicted Difference of first lactation between sires of sons was small compared with the variance of sons within sires. It was postulated that effective selection on the sire-to-sire path on Predicted Difference of first lactation had reduced predictability on the sire-to-sire improvement path. An interaction of sire by number of lactations may be inferred from the incomplete genetic correlations between Predicted Differences of first and following lactations and from the reduction in the variance between sire in first but not in later lactations. Progeny tests of single lactation seem warranted for the production profile of dairy sires.

Animals↗
PubMed1983

Genetic correlations among progeny groups for type traits, milk yield, yield persistency, and culling rates.

Associations among six primipara type traits and first and second lactation milk yield, yield persistency, and culling rates were estimated by means of 100 progeny groups with first and 76 with second lactations. Correlations of second lactation culling rate with dairy character and with rear udder were approximately -.4. Persistency, measured in either first or second lactation, was negatively associated with all type traits.

Animals↗
PubMed1983

Neonatal outcome in cesarean section under general anesthesia, related to gestational age, induction-delivery and uterus-delivery intervals.

Neonatal outcome after cesarean section under general anesthesia was studied in 568 women in whom no prior signs of fetal distress were evident. Low Apgar 1-minute scores were not related to induction-delivery and/or to uterus-delivery intervals, which were all within the accepted safe limits, but were related to the gestational age. Thus, Apgar scores less than 7 were found in 62% of newborns whose gestational age was less than 35 weeks, but in only 17% of those greater than or equal to 35 weeks. The importance of gestational age, in addition to the induction-delivery and uterus-delivery intervals, is discussed in relation to neonatal outcome following cesarean section.

Adolescent↗