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Biomedical subjects

M A Sala

Publications and source records attributed to M A Sala.

At least 19 recordsLinked to original sources
PubMed1998

A morphometric study of maternal smoking on apoptosis in the syncytiotrophoblast.

OBJECTIVES: To study syncytiotrophoblast apoptosis in the placenta of smoking and non-smoking pregnant women. METHODS: Twelve neonates, pregnancies and placentas were available for study. Eight mothers smoked during pregnancy and the remaining four were non-smokers used as control subjects. The main outcome measure was the apoptotic syncytiotrophoblast index for each group. Apoptosis was detected by immunohistochemistry using the TUNEL method and quantitatively measured using a Merz grid. The apoptotic syncytiotrophoblast index was calculated as the ratio of mean apoptotic labeling to percent terminal villus area using high-power field microscopy. RESULTS: Significant differences in apoptotic syncytiotrophoblast index were observed between the control group (15.06+/-3.72) and the smoker group (1.66+/-1.74) (P < 0.0001, Mann-Whitney test), but no differences were detected in clinical or morphometric data between groups. CONCLUSIONS: The human placental syncytiotrophoblast undergoes apoptosis and this process is associated with inhibition of apoptosis by the smoking habit. The same way as the presence of trophoblast apoptosis is associated with modifications of the maternal-fetal exchange, the inhibitory effect of the smoking habit on syncytiotrophoblast could be responsible for the poor prognosis of pregnancy in the presence of maternal smoking.

Adolescent↗
PubMed1995

Effect of acyclovir on rat fetus palate mucosa.

Five pregnant rats were treated during organogenesis with sc injections of acyclovir (50 mg/kg body weight) on days 9, 10 and 11 of pregnancy. The fetuses (N=62) were evaluated on day 20 of gestation and presented decreased body weight as well as delayed differentiation of fetal rat palate epithelium, with increased nuclear volume, decreased cytoplasmic and cellular volumes, decreased epithelial and keratin thicknesses, and increased cellular numerical density.

Abnormalities, Drug-Induced↗
PubMed1994

Effect of hyperthermia on rat fetus palate epithelium.

Maternal hyperthermia during gestation induces delayed cellular growth and differentiation in fetal rat palate epithelium, with increased nuclear, cytoplasmic and cellular volumes, increased epithelial thickness, decreased keratin and cellular numerical density.

Animals↗
PubMed1993

Alcohol-induced alterations in the palate epithelium of the rat fetus.

Maternal alcoholism (ethanol and sugar cane brandy) during gestation induces delayed cellular growth and differentiation in fetal rat palate epithelium, with increased nuclear, cytoplasmic and cellular volumes, increased epithelial and keratin thickness and decreased cellular numerical density.

Animals↗
PubMed1990

Morphological, morphometric and stereological study of submandibular glands in rats with lesion of the anteroventral region of the third ventricle (AV3V).

Lesions of the antero-ventral region of the third ventricle induce in the rat submandibular gland parenchyma, atrophy through vascular ischemia, and simultaneously increased fibrosis of the connective tissue, probably by alteration of the pituitary gonadotropins (FSH, LH), thyrotrophic hormone (TSH), growth hormone and probably insulin levels.

Animals↗
PubMed1989

Placental characteristics in twin transfusion syndrome.

The authors describe the histological features of the placenta in a typical case of twin-to-twin transfusion, with particular attention focused on the stereologic aspects. Villi from the anemic placental portion were slightly edematous, with small and inconspicuous vessels. The stereologic characteristics of this portion were nearer values of normal placentas. The plethoric region appears as a postmature organ, with a very thin trophoblast layer and numerous vasculo-syncytial membranes. The most dramatic alterations of this region were mainly related to the foetal capillary. According to the stereologic results, the consecutive circulatory alterations would facilitate the maternal-fetal exchanges in the plethoric placental territory, thus justifying the greater development of this twin.

Adult↗
PubMed1989

Enzymatic histochemistry of the human umbilical vessels.

The enzymatic activities of human umbilical vessels from normal term pregnancies were studied by histochemical methods. The results obtained suggest that oxidative phosphorylation is of little importance, whereas pentose cycle and anaerobic glycolysis are probably the most important sources of energy in the umbilical vessels. The presence of leucine aminopeptidase activity in the venous endothelium probably represents a defensive mechanism inactivating oxytocin.

Histocytochemistry↗
PubMed1989

Measurement of the villus surface area and its regional variation in the human full-term placenta.

The surface/volume ratio and the surface density of the chorionic villi in different cotyledonary regions of the human mature placenta were studied by stereologic methods. The villus surface/volume ratio showed a mean value of 812.3 cm2/cm3 (standard deviation = 89.2 cm2/cm3). There were no significant differences according to the site from which the sample was obtained. The villus surface density in normal mature placentae was (496.3 +/- 49.0) cm2/cm3. The last parameter showed no differences among regions. Despite the absence of significant differences of exchange surface areas among the cotyledonary regions considered, other important parameters, such as trophoblast thickness, frequency of vasculo-syncytial membranes, as well as the maximal gradient of concentration, facilitates the maternal-fetal transfer by simple diffusion mechanism in the central-parabasal region.

Chorionic Villi↗
PubMed1986

Regional variation of the vasculo-syncytial membranes in the human full-term placenta.

The authors determined the frequency of vasculo-syncytial membranes in different cotyledonary regions of the full-term placenta. There were significant differences according to the site from which the sample was obtained. The highest frequency (164,3%) corresponds to the central-parabasal region of the cotyledon, close to the point of entry of the maternal blood into the intervillous space, whereas the lowest value (104,5%) corresponds to the lateral-subchorial region. The results of the present study as well as those reported by others suggest that the villi from the central-parabasal region are the best adapted ones for gas transfer between maternal and fetal blood.

Female↗
PubMed1984

Histochemical study of the fetal membranes in the human term pregnancy.

The histochemical distribution of polysaccharides and proteins was studied in the human fetal membranes from term pregnancies. The neutral polysaccharide reactions were stronger in the trophoblast layer of the chorion and in the decidua, whereas the acid mucopolysaccharides were equally intense in the connective layers and in the decidua. The protein reactions were always stronger in the decidua. It was demonstrated the existence of a cover of acid mucopolysaccharides over the apical surface of the amniotic epithelium. The possible participation of this cover in water and electrolytes transfer is discussed.

Extraembryonic Membranes↗
PubMed1984

A stereologic study on the thickness of the trophoblastic layer and its regional variation in the human term placenta.

A new stereological method was applied to estimate the average thickness of the trophoblastic layer in chorial villi from different regions of the human term placenta. Statistically significant differences were demonstrated among the 5 regions considered. The results suggest that the thickness of the trophoblastic layer is related to the pO2 gradient in the intervillous space blood.

Chorionic Villi↗
PubMed1983

Volume density of syncytial sprouts and its regional variation in the human mature placenta.

The authors studied by means of sterological methods the volume density of syncytial sprouts in different cotyledonary regions of the human term placenta. The syncytial sprouts account for 4.92% of the placenta volume. Meanwhile, there were significant differences according to the site from which the sample was obtained. The lowest value (2.72%) corresponds to the central-parabasal zone of the cotyledon, close to the entry of the maternal blood into the intervillous space, whereas the highest values correspond to the "venous" regions. The results of the present study, as well as those reported by others, suggest that the lateral-subchorial zone would be the growing region of the cotyledon.

Adult↗
PubMed1983

Stereological analysis of syncytiotrophoblast from human mature placenta.

Syncytiotrophoblast from human term placenta, studied by stereological methods both by light and electron microscopy, was shown to account for 19.49% of the placenta volume. Significant differences in volume density were observed in syncytiotrophoblast from villi obtained from different regions of the cotyledon. These differences may be caused by the heterogeneous conditions of oxygenation in the intervillous space blood and its effect on trophoblastic growth. The volume density of the organelles, related to syncytioplasm volume, was 0.0524, 0.0122, 0.0033 and 0.1136, for mitochondria, lysosomes, Golgi complex and endoplasmic reticulum, respectively. There were no differences in the volume densities of the different organelles among the four cotyledonary regions studied.

Female↗
PubMed1980

A mathematical model for the curves of intrauterine growth.

Different mathematical models for a chart of intrauterine growth were tested attempting to employ uncomplicated curves. In this manner, a chart of foetal growth was elaborated by plotting the cube root of neonate weight against the gestational age. Two different regions can be clearly seen in this chart of growth. In the first one, until the 34th week of pregnancy, there is a linear relationship between the two variables. In the second region, for pregnancies above the 34th week, the curve has a quadratic equation, reaching the maximum between the 43rd and 44th week, decreasing posteriorly. The goodness of fit obtained by the present mathematical model is more satisfactory than that obtained by mathematical models with a single linear equation.

Anthropometry↗