Association of circulating endothelium and noradrenaline with increased calcium-channel binding sites in the placental bed in pre-eclampsia.

OBJECTIVE: To evaluate factors contributing to both placental hypoperfusion and maternal vasoconstriction in pre-eclampsia. DESIGN: Single centre, comparative study of calcium-channel density and affinity in the placental bed of pregnant women with normotension and pre-eclampsia. SETTING: Teaching hospital. PARTICIPANTS: Twenty-two primigravidae in the third trimester of pregnancy: 10 with pre-eclampsia and 12 normotensive. METHODS: Plasma levels of endothelin-1 (by RIA) and noradrenaline (by HPLC-ED) were measured. Both pharmacological characterisation and anatomical localisation of dihydropyridine-sensitive binding sites (using radioligand-binding studies and autorradiographic techniques) were determined with 3H-isradipine in placental bed tissues to determine both the density (Bmax) and the affinity (Kd) of receptor sites. RESULTS: Higher plasma levels of endothelin-1 and noradrenalin were found in women with pre-eclampsia compared with normotensive women. Placental bed tissues bound 3H-isradipine in a saturable, reversible time and temperature-dependent manner with very low Kd values. Study of the 3H-isradipine specificity binding included the use of several dihydropyridine displacers. In the group with pre-eclampsia the Scatchard analysis of the results showed a significant increase (P < 0.001) both in the affinity [Kd = 0.23 nmol (0.04) vs 0.45 nmol (0.03), pre-eclampsia vs normotensive] and in the density of calcium-channel binding sites [Bmax = 77.70 fmol/mg (1.30) vs 64.30 fmol/mg (1 80) tissue, pre-eclampsia vs normotensive]. Autoradiography confirmed that in the placental bed tissue of those with pre-eclampsia there was a much higher silver grain density in the arteries walls, compared with normotensive women. CONCLUSIONS: In pre-eclampsia there is an increase in the maternal circulation of two strong vasoconstrictor factors (endothelin-1 and noradrenalin) and a sharp increase both in the density and the affinity of calcium-channel binding sites in placental bed central area. The latter may strongly contribute to the perpetuation of the uteroplacental hypoperfusion either by itself or by amplifying the local actions of circulating factors, such as endothelin-1 and noradrenalin.

[Breast feeding, a nature-culture hybrid]. / Amamentação: um híbrido natureza-cultura.

This article consists in an essay that aims, through a review of bibliography, to discuss the relation between a proposal of Bruno Latour about nature-culture and breast feeding. According to his proposal, having as reference an epistemological view, there is an attempt to establish dialogue between different scientific achievements with a view to contribute to the improvement of this subject in the field of public health. Firstly, the paradox of weaning is found in the scenery of knowledge and practices of breast feeding. The analysis is based on the relationship nature-science and culture-society, which are present in the process of breast feeding. Finally, the discussion has the aim of dealing with breast feeding as long as a hybrid between nature and culture, starting a new issue to the continuity in the debate about the thematic in question.

[Wilson's disease ("hepatic form") in a region endemic for schistosomiasis mansoni: clinical presentation of 25 patients]. / Doença de Wilson ("forma hepática") em região endêmica para esquistossomose mansoni: apresentação clínica de 25 pacientes.

Brazil has a young population and areas of endemic mansoni schistosomiasis where Wilson's disease might be easily misdiagnosed in patients erroneously classified as having either the hepatosplenic or the hepatointestinal form of the helminthiasis. Twenty five patients with the "hepatic form" of Wilson's disease (14 males and 11 females) were investigated in Belo Horizonte, MG; the mean age was 13.7 years (3 to 22). Nineteen had hepatomegaly (76%) and nine splenomegaly (36%). Twenty two (88%) had cirrhosis. The Kaiser-Fleisher ring was detected in fifteen (60%). Four (16%) had clear neurological abnormalities. Eleven (44%) had ascitis and/or jaundice. Ninety one point three per cent and 92% had low ceruloplasmin and copper serum levels respectively. Eighty four point two per cent showed an increased 24 hours urinary copper excretion; seven patients in whom hepatic copper was determined had increased values. Six out of nine had at least a ten fold increase in 24 hours urinary copper excretion following penicillamine use ("penicillamine test"). Three out of 19 patients (15.8%) had mansoni schistosoma ova in stools examination, a common prevalence in our population. Their biopsies showed inactive cirrhosis without schistosomiasis-associated alterations. At least fourteen patients (56%) could be misdiagnosed as having hepatointestinal or hepatosplenic schistosomisis when in fact they suffered from Wilson's disease with or without asymptomatic intestinal schistosomiasis, losing the chance of an early treatment. The follow-up time of 22 patients was 52 months (1 to 96); eight (36.3%) died, four from bleeding esphageal varices, three from terminal hepatic failure and one from fulminant liver failure. The majority of the patients, including those who died, had abandomned the use of penicillamine or had taken it irregularly, due mainly to its highly expensive cost. A 17 year old patient underwent a successful liver transplant in 1989.

Loss of dopamine D1-like receptors in the umbilical artery of pre-eclamptic subjects.

1. The influence of pre-eclampsia on the density and pattern of dopamine D1-like receptors was studied in frozen samples of the placental end of the umbilical artery by using radioligand binding and autoradiographic techniques in combination. 2. Analysis was performed on normotensive (n = 10) and pre-eclamptic subjects (n = 9) undergoing caesarean delivery, using [3H]-SCH 23390 as a ligand. Pre-eclamptic patients received a low salt diet and were treated with magnesium sulphate and hydralazine. The possibility that this treatment may cause changes in the density of dopamine D1-like receptors was evaluated by treating male Wistar rats in the same way and by determining [3H]-SCH 23390 binding in sections of the kidney which represents an organ containing dopamine D1-like receptors. 3. The density of dopamine D1-like receptors of the umbilical artery, which are probably vasodilatory, was decreased in pre-eclamptic compared with normotensive subjects. In contrast, the affinity of the radioligand for dopamine D1-like receptors was not statistically different between normotensive and pre-eclamptic subjects. Low salt diet, magnesium sulphate and hydralazine treatment did not affect [3H]-SCH 23390 binding to sections of rat kidney. This suggests that changes in the density of dopamine D1-like receptors in pre-eclamptic patients are a specific phenomenon not dependent upon antihypertensive measures. 4. Analysis of the pharmacological profile of [3H]-SCH 23390 binding to sections of the umbilical artery both in normotensive and pre-eclamptic subjects indicates the labelling of dopamine D5 receptors. 5. These findings collectively suggest that the dopaminergic vasodilatory tone in the umbilical artery is impaired in pre-eclampsia. The possible significance of these data should be clarified in future studies.

Pharmacological characterization and autoradiographic localization of dopamine D1 receptors in the human umbilical artery.

Combined in vitro radioreceptor binding and autoradiographic techniques with [3H]SCH 23390 as a ligand were used to analyze the pharmacological profile and anatomical localization of dopamine D1 receptor sites in sections of human umbilical artery. The ligand was bound to sections of the artery in a manner consistent with the labelling of D1 receptors. These receptors, which show a fetal-to-maternal gradient with the highest concentration near the placenta, are located within the smooth muscle layer of the umbilical artery. The above findings suggest that endogenous dopamine may be involved in the control of the tone of the umbilical artery through the interaction with D1 receptors.

Predominance of oxidative deamination in the metabolism of exogenous noradrenaline by the normal and chemically denervated human uterine artery.

Longitudinal strips were prepared from human uterine arteries obtained at hysterectomy. The artery had a low content of noradrenaline and dopamine, contrasting with a high content of the deaminated catechols, dihydroxyphenylglycol (DOPEG) and dihydroxymandelic acid (DOMA), which together represented 98% of endogenous catechols. When incubated with 3H-noradrenaline (0.1 mumol/l), the uterine artery removed, accumulated and metabolized noradrenaline. Deaminated metabolites predominated, DOMA being the most abundant metabolite. Cocaine markedly reduced the accumulation of 3H-noradrenaline and abolished 3H-DOPEG formation, but did not change 3H-DOMA. Selective monoamine oxidase (MAO) inhibitors (clorgyline, selegiline and 2-amino ethyl carboxamide derivatives) caused a marked decrease in the amounts of 3H-DOPEG, 3H-DOMA and 3H-O-methylated and deaminated metabolites (OMDA) formed by the tissue and an increase in 3H-normetanephrine (NMN) formation. Inhibition of catechol-O-methyltransferase suppressed NMN formation and reduced that of OMDA; hydrocortisone slightly depressed the formation of DOMA and OMDA. Homogenates of the uterine artery deaminated 3H-5-HT, 14C-phenylethylamine and 3H-tyramine; inhibition curves of the deamination of 3H-tyramine by clorgyline and selegiline were compatible with the presence of both MOA A and MOA B. Exposure of the strips to 6-hydroxydopamine (1.5 mmol/l for 20 min; 3 exposure periods followed by washout periods of 15,15 and 30 min) resulted in complete and selective chemical denervation of the arterial tissue. This chemical denervation had effects which were similar to those of cocaine. The 2-amino ethyl carboxyamide derivatives markedly reduced the formation of deaminated metabolites by the denervated strips.(ABSTRACT TRUNCATED AT 250 WORDS)

[Prevalence of intestinal parasitosis in feces collected during necropsies]. / Prevalência de enteroparasitoses em fezes colhidas durante necrópsias.

With the intention to verify the frequency of intestinal parasites, we have taken the inside digestive system material from three different parts of the intestinal tract while we were doing 135 complete necropsies. The stools were kept in MIF (Formol, iodine and merthiolate mixture) being studied in slides by the direct method. We have found intestinal parasites in 40 cases (29.6%), 11 (27.5%) with two or more kinds of parasites and 29 cases (72.5%) with only one kind of parasite. The most frequent parasites were: S. stercoralis (31,9%), E. hystolytica (23.4%), hook worm (19.1%) and A. lumbricoides (17%). The results are in according with epidemiological research made in this area. Thus, they prove that the parasitological exam made in feces taken during the necroscopy provides further evidence to enrich the anatomo-pathological diagnosis.