Biological research in pregnancy and perinatology最新文献

The early mitochondria show a lower cytochrome P-450 specific concentration and cholesterol side-chain cleavage activity as compared to the term placental mitochondria. These differences occur mainly in the heavy fraction of placental mitochondria.

Two metal-binding proteins, designated as PI and PII, were isolated and purified from normal term human placentas by gel filtration and ion-exchange chromatography. The molecular weights were determined to be 10,000 and 12,000 daltons, and isoelectric points (pI) were 4.8 and 5.9, respectively. The amino acid composition of these proteins was quite different from that of metallothionein. Total amount of acidic amino acid residues was in large excess over that of basic amino acid residues. Cadmium and zinc were the major metals bound to these proteins. The metal contents of cadmium and zinc in placental tissue were 39.34 and 22.23 ng/g placenta, respectively, as measured by flame atomic absorption spectrophotometry. The in vitro translated metal-binding proteins encoded by the corresponding mRNA were characterized by the purified rabbit antiserum against PI and PII. The demonstrated presence of these metal-binding proteins in human placenta suggests its possible role of detoxification activity and protective effect to the fetuses in utero.

(Na+-K+)-ATPase activities of liver, hind leg skeletal muscle, brain, perirenal white adipose tissue, interscapular brown adipose tissue and blood as well as placenta, fetal liver and fetal blood were determined in virgin rats and pregnant rats on days 12, 19 and 21 of gestation in order to evaluate its relative contribution either to metabolite transport processes or/and to thermogenesis during pregnancy. No changes were found in (Na+-K+)-ATPase activity in liver, blood and white adipose tissue in pregnant rats versus controls. (Na+-K+)-ATPase activity from muscle, brain and interscapular brown adipose tissue decreased during pregnancy and placenta showed an increase of (Na+-K+)-ATPase on day 21 of gestation in respect to day 12. No significant changes were observed either in fetal liver or fetal blood.

Intramitochondrial distribution of the cholesterol side-chain cleavage reaction was investigated in human placental mitochondria. The matrix side of the inner mitochondrial membrane has been found to be most probably side of this reaction.

To study physiological variations in serum growth factors during peripartal period, we have measured levels of a serum growth-promoting activity (thymidine activity, TA) and radioimmunoassayable somatomedin C (Sm-C) during labor in 39 women who delivered spontaneously (group A), by caesarean section (group B) and by legal abortion (LA) (group C). TA values were higher in the group A than in the group B and C, suggesting an important effect of uterine contractions in TA generation. A major role in Sm-C production seems to be played by the length of gestation since Sm-C concentrations were significantly higher in mothers delivered by caesarean section than in LA women. During labor influence of estrogens and progesterone in growth factor production seems unlikely because of the lack of correlation with TA and Sm-C levels. The lower TA values in placental flow than in the capillary blood of newborn suggest that serum growth factors, measured as TA, are produced by the newborn and do not cross through the placenta. These data suggest that the absolute dependence of the fetus on the mother does not preclude instances of fetal autonomy.

Ultrafiltrable metabolites in human term placenta and umbilical cord were analysed by means of 13C-NMR spectroscopy and gas-liquid chromatography. In these tissues, existing in a very reduced redox state, lactate and polyols (sorbitol, myoinositol and xylitol) were found to be the major accumulated intermediates of the glycolytic pathways. The cord tissue preferentially took up myoinositol.

The distribution of drug acetylator phenotypes in 100 healthy newborn infants was studied and compared with the acetylator phenotypes frequency in different age groups. Phenotyping was performed by assaying total and free sulphadimidine in the urine after single oral test dose of the drug/100 mg. As in elderly subjects, slow acetylator phenotype was predominant also in healthy newborns (83%), which was the highest frequency of all age groups observed. Acetylator phenotype in the newborn infants may be influenced by genetic, environmental (e.g., nutritive), as well as by developmental factors (e.g., postnatal enzyme deficiency, age-specific changes in organ functions, etc.). In this connection, slow acetylator phenotype of the neonate may be related to a negative pantothenic acid balance causing insufficient Coenzyme-A synthesis, too. The predominance of the slow acetylator phenotype resulting in higher drug sensitivity can be regarded clinically as a special risk factor in human neonates.

Between 1983 and 1984 a double-blind randomized study with progesterone substitution in threatened abortion was carried out. Fifty-six patients with vaginal bleeding during the first trimester of pregnancy, the internal cervical os being closed, were referred to the hospital. Twenty-five women (5th and 6th week of gestation) with positive serum concentrations of beta-hCG were admitted to the study without regard to sonogram results. In other 25 women (7th-10th week of pregnancy) and 6 women (greater than or equal to 11th week of pregnancy) fetal heart action and movement could be demonstrated by ultrasound. The patients were prescribed bed rest and vaginal suppositories twice daily, containing either 25 mg progesterone or only polyethylene glycol. The code was not broken until after completion of the study. Serial serum determinations of beta-hCG, estradiol-17 beta (E2), progesterone, and ultrasound were performed. Four patients had to be omitted from final analysis (two tubal pregnancies, one intrauterine infection, one sectio parva). Three of 26 patients progesterone (11%) and five of 26 patients with placebo (19%) had an abortion, which represented no significant difference. Frequency of abortion was increased in women more than 30 years old, in women with previous abortions and after ovulation induction. Progesterone treatment resulted in a significant elevation of serum progesterone concentrations (p less than 0.01), while beta-hCG and E2 were unchanged. The results of this study confirm that pregnancy outcome is favorable in women with bleeding and normal hormone concentrations without hormonal treatment and unfavorable in women with reduced beta-hCG and E2-concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Maternal and fetal blood gas values were studied in 90 selected mothers of comparable age, weight, duration of pregnancy and hematocrit values undergoing cesarean section under balanced general anesthesia in four differing clinical situations: elective with and without placental dysfunction, and emergency with and without fetal distress in apparently normal mothers. Pre-induction (Fi O2 0.21) and pre-delivery (Fi O2 0.60) maternal blood gas analysis, along with umbilical cord blood gas analysis were performed in all cases. Apgar scoring was carried out at one minute and three minutes and correlated with the blood gas values. Out of the 90 cases studied, 36 neonates (40%) showed good apgar scores of greater than seven at one minute and three minutes and correlated well with maternal blood gas values which were within normal ranges. Of the remaining 54 cases (60%) with similar mean maternal gas values the neonates showed an apgar score of less than seven in the first minute. The score improved in three minutes in 35 of them (66%), and umbilical cord blood gas values showed a low pH (umbilical vein 7.22 +/- 0.02 units, umbilical arterial 7.21 +/- 0.01 units) but satisfactory pO2 (umbilical vein 39.4 +/- 1.9 torr, umbilical arterial 2.5 +/- 1.3 torr).(ABSTRACT TRUNCATED AT 250 WORDS)