Effects of maternal sodium depletion on the composition of ovine fetal fluids

Effects of maternal sodium depletion on the composition of ovine fetal fluids were studied. Maternal Na depletion was achieved by 48-h drainage of parotid saliva. There was a significant decrease in both maternal and fetal plasma Na concentration, indicating that both mother and fetus had experienced the Na-depletion stimulus. There was a significant increase in maternal blood aldosterone but the change in fetal blood aldosterone was not significant. In animals where there was an increase in fetal blood aldosterone the increase could be accounted for by transfer of aldosterone across the placenta from the mother. There was a significant decrease in fetal urinary Na concentration and Na excretion and the urinary Na/K ratio fell in seven out of eight studies. These observations are consistent with the hypothesis that fetal Na depletion sensitizes the fetal kidney to the action of circulating aldosterone as in the adult.

The value of urine osmolality as an index of stress in the ovine fetus

In ovine fetuses, during 100-130 days of gestation, urine osmolalities less than 175 mosmol/kg water were associated with plasma immunoreactive adrenocorticotrophin (ACTH) concentrations below 40 pg/ml in 40/41 samples. In 18/29 fetuses with urine osmolalities greater than 175 mosmol/kg water plasma ACTH was significantly elevated. In 38 samples of fetal blood there was a significant correlation between plasma ADH and ACTH concentrations. By least squares regression the equation to the line was [ACTH] = 5.06 + 3.70 [ADH] (r = 0.62, P less than 0.001). In 50 samples from fetuses of gestational ages 100-140 days, with urine osmolalities of 302 +/- 86 mosmol/kg (mean +/- SD) the blood pH, pO2 and pCO2 values were not significantly different from those in 50 samples from fetuses with urine osmolalities of 125 +/- 22 mosmol/kg. It is proposed that the measurement of fetal urine osmolality provides a good index of fetal stress. A fetus with a urine osmolality less than 175 mosmol/kg is almost invariably in the optimum, unstressed condition.

Development of the hypothalamic-pituitary-axis in the ovine fetus: ontogeny of action of ovine corticotropin-releasing factor

In samples from twenty chronically cannulated ovine fetuses the plasma immunoreactive adrenocorticotrophin (ACTH) concentrations were 12.5 +/- 3.2(8), 15.2 +/- 4.1(9) and 21.2 +/- 5.6(8) pg/ml at periods, prior to parturition, of -30 to -35, -25 to -29 and -20 to -24 days respectively. Values are mean +/- SEM (number of samples). These values were not significantly different from each other but were significantly lower (P less than 0.02) than values in the next two age groups -36.0 +/- 4.9(7) pg/ml at -19 to -15 days, and 39.6 +/- 6.6(11) pg/ml at -14 to -9 days. A further significant increase (P less than 0.05) occurred in the -8 to -3 day period, ACTH being 53.9 +/- 5.4(12) pg/ml. On day of delivery two samples had values of 325 and 360 pg/ml. A single injection, intravenously of 1.0 microgram ovine corticotrophin-releasing factor (O-CRF), caused a significant increase in fetal plasma ACTH concentrations in fetuses of -6 to -23 days prior to delivery but not in fetuses -24 to -35 days prior to parturition. The maximum values of ACTH after O-CRF were significantly greater in fetuses -2 to 0 days prior to parturition than in younger fetuses (P less than 0.01). In 6 experiments in 4 fetuses (parturition -1 to -13 days) the effect of 1.0 microgram O-CRF persisted for at least 2.5 h. The results support the hypothesis that the pituitary release of ACTH changes sensitivity to hypothalamic O-CRF at least twice during the last fifth of gestation; an increasing sensitivity is seen as term approaches.

t-[3H]butylbicycloorthobenzoate: new radioligand probe for the gamma-aminobutyric acid-regulated chloride ionophore

t-[3H]Butylbicycloorthobenzoate [( 3H]TBOB; 22 Ci/mmol) was prepared by reductive dechlorination of its 4-chlorophenyl analog with tritium gas. This new radioligand binds reversibly to fresh washed rat brain P2 membranes in 500 mM NaCl plus 50 mM sodium-potassium phosphate buffer (pH 7.4) at 25 degrees C, with 80-90% specific relative to total binding, a KD of 61 +/- 15 nM, and a Bmax of 1.6 +/- 0.5 pmol/mg of protein. [3H]TBOB association with its binding site(s) is monophasic, but its dissociation is biphasic. The binding characteristics of [3H]TBOB are essentially identical to those of t-[35S]butylbicyclophosphorothionate [( 35S]TBPS) with respect to pH dependence, stimulation by anions, regional distribution in the brain, and pharmacological profile. Saturation analyses and dissociation studies further indicate that TBOB and TBPS have a common binding site. However, binding of the two radioligands differs in respect to temperature effects. In contrast to [35S]TBPS, which exhibits negligible binding at 0 degrees C, [3H]TBOB binds to rat brain membranes at 0, 25, and 37 degrees C with similar KD values. [3H]TBOB with its long radioactive half-life and temperature-independent KD is a valuable supplement to [35S]TBPS in further biochemical and pharmacological characterization of the gamma-aminobutyric acid receptor-ionophore complex.

Neutralisation of Trichoplusia ni nuclear polyhedrosis virus with antisera to two forms of the virus

Two forms of a baculovirus, Trichoplusia ni nuclear polyhedrosis virus, one released at the plasma membrane of cells (cell released virus: CRV) and the other derived from polyhedra (polyhedron derived virus: PDV) occur naturally. Antisera raised against the two forms specifically neutralised the homologous form. The envelope proteins of the two forms were shown to be the major proteins involved in serum neutralisation and to be responsible for the antigenic diversity of the virus forms.

Characterization of the immunosuppressive effect of burned tissue in an animal model

The immunosuppressive effect of burned tissue was studied using a mouse burn model. To evaluate the immunologic status an in vivo measure of cell-mediated immunity (CMI) involving contact sensitization of mice by painting the skin with dinitrofluorobenzene was used; mice were challenged 5 days later by painting the ear with the same antigen. Ear swelling in response to antigenic challenge was used as a quantitative measure of CMI; diminution in ear swelling in treatment mice compared to sensitized, unburned control mice indicated the degree of immunosuppression. A full-thickness steam burn covering 20% body surface ares (BSA) was profoundly immunosuppressive as reflected by ear swelling of 45 to 60% of that found in normal mice; partial thickness burns and burns of 10% BSA extent were not significantly immunosuppressive. Transfer into unburned mice of burned skin equivalent in size to a 20% BSA burn eschar resulted in marked immunosuppression, but transfer of smaller amounts of burned skin, or of larger amounts of unburned skin and normal and burned liver tissue, did not produce immunosuppression. Mice receiving a very high-temperature (300 degrees C), dry burn were only slightly more suppressed than mice receiving a standard steam burn. Normal immunity was preserved in burned mice which received daily application of cerium nitrate to the wound for 7 days, but application of other topical agents commonly used in burn treatment did not preserve immunity. Postburn immunosuppression thus appears related quantitatively to toxic factors in burned skin, and these toxic factors can be abrogated in burned mice by the topical application of cerium nitrate.

Interactions of methylestrogens with cytoplasmic and nuclear estrogen receptors in rat pituitary gland, hypothalamus and uterus

The in vitro affinities to cytoplasmic estrogen receptors of the methylestrogens 2-methylestradiol-17 beta, 4-methylestradiol-17 beta and 4-hydroxy-2-methylestradiol-17 beta, which are useful probes to test the biological importance of 2- or 4-hydroxylation of estradiol-17 beta (catecholestrogen formation), have been determined in hypothalamic, pituitary and uterine tissue of the ovariectomized rat. Moreover, the in vivo capacity of these compounds to translocate estrogen receptors into the cell nucleus of pituitary and uterine tissue has been studied. Methylestrogens exhibited estrogen receptor affinities which were not significantly different from the binding affinity of estradiol-17 beta. When given at a high dose (100 micrograms/animal) their nuclear translocation capacity was equal (4-methylestradiol-17 beta) or even higher (2-methylestradiol-17 beta) than that of estradiol-17 beta. However, at a low dose (5 micrograms/animal) 4-methylestradiol was completely ineffective in both the pituitary gland and the uterus, and 2-methylestradiol-17 beta was less potent than estradiol-17 beta in the pituitary gland.

Baculovirus replication: inhibition of Trichoplusia ni multiple nuclear polyhedrosis virus by [E]-5-(2-bromovinyl)-2'-deoxyuridine

[E]-5-(2-bromovinyl)-2'-deoxyuridine (BVdU) inhibits the replication of the baculovirus Trichoplusia ni multiple nucleocapsid nuclear polyhedrosis virus in Spodoptera frugiperda cells. Virus-specific DNA synthesis and late protein synthesis are suppressed by the drug. BVdU is phosphorylated by deoxythymidine (deoxycytidine) kinase present in both uninfected and virus-infected cells, and in its 5'-triphosphate form it inhibits DNA polymerase activity in virus-infected cells. The effect of the BVdU is not completely reversible. Phosphonoacetic acid, phosphonoformic acid and Acyclovir have no effect on baculovirus replication. Acyclovir fails to compete with deoxycytidine and thymidine as substrates for pyrimidine deoxynucleoside kinase in virus-infected and uninfected cells.

An outline of population geography of Jiangsu province, China

"Jiangsu (Kiangsu) Province [China] is located in the lower reaches of the Yangtze River which divides it into two parts, South Jiangsu and North Jiangsu. The area of the province is 102,000 sq. km with a population of 60,521,114 and a density of 605 per sq. km in 1982. The area of Jiangsu is slightly larger than that of Hungary (93,000 sq. km). But the population is 5.7 times and the density of population 5.2 times larger than those of Hungary. This paper states the tendency of population growth, the geographical distribution and present condition of urban and rural population, discussing briefly the rational redistribution of [the] population of Jiangsu."