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Biomedical subjects

M Matheus

Publications and source records attributed to M Matheus.

At least 19 recordsLinked to original sources
PubMed1992

[Results of studies of surgically treated carpal tunnel syndrome with obligate tenosynovectomy of the flexor tendons].

The authors present a follow-up of thirty five patients with carpal tunnel syndrome, who had undergone surgical treatment including synovialectomy of the flexor tendons. Beyond the clinical findings, pre- and postoperative comparison of the electromyograms, conduction velocities and an exact analysis of the lipid disorders were studied. These findings and the results of the histological analysis of the tenosynovial membrane are evaluated with special regard to the etiology of the carpal tunnel syndrome.

Adult↗
PubMed1990

[Clinical and angiographic characteristics of acute anteroseptal and upper lateral myocardial infarction: obliquous infarction; proposal of a new denomination for a specific type of infarction].

PURPOSE: Analysis of clinical and angiographic characteristics of oblique (anteroseptal and high lateral) myocardial infarction. MATERIAL AND METHODS: Forty-two patients, 33 men, aged 30 to 79 years (mean 57) with oblique myocardial infarction were clinically evaluated and through coronary arteriography between ten day and eight months (mean of two months) of the acute event. RESULTS: Twenty patients had severe proximal lesions of left anterior descending artery (LAD), being single in thirteen. Four cases showed severe lesions in two arteries and three cases in three arteries. Fourteen patients exhibited collateral circulation to LAD or recanalization. Ejection fraction values were between 0.12 and 0.65 (mean 0.38). Eight patients died, four of them due to myocardial failure and four due to noncardiac causes. During follow-up angina pectoris was present in five, stroke in three and pulmonary embolism in two patients. CONCLUSION: Oblique myocardial infarction is associated with single and proximal lesion of LAD in the majority of the patients who underwent coronary arteriography, with low incidence of cardiac failure and death.

Adult↗
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↗
PubMed1980

The importance of placental examination in newborns with single umbilical artery.

Examination of placentas from newborns with single umbilical artery (SUA) can furnish valuable data to Perinatologists. Thus, 33.3% of the SUA newborns with gross macroscopic alterations of the placenta were malformed. In the other hand, 75% of the malformed SUA newborns had gross placental alterations. It is pointed out the importance of examination of the placenta, even at unaided eye, as a tool to prevent the Perinatologist in search of probable malformations (both apparent or occult).

Female↗