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Biomedical subjects

V C Carvalho

Publications and source records attributed to V C Carvalho.

10 recordsLinked to original sources
PubMed1995

Nerve cell loss in the myenteric plexus of the human esophagus in relation to age: a preliminary investigation.

Morphometric measurements have been carried out on the human myenteric esophageal neurons at the ages of 20-40 and more than 70 years. The number of neurons decreases after 70 years of age, which is accompanied by an increase in the sizes of the neurons. In percentage terms the decrease in the number of neurons in the aged varied from 22 to 62% along the esophagus being most pronounced in its superior third at the junction with the pharynx.

Adult↗
PubMed1992

Alterations in the levels and lipid composition of plasma lipoproteins (VLDL, LDL and HDL) in Brazilian patients with hepatosplenic schistosomiasis mansoni.

1. The plasma concentrations of low- and high-density lipoproteins (LDL and HDL) were significantly reduced in Brazilian patients with compensated hepatosplenic schistosomiasis mansoni (SM) when compared with healthy individuals, but very low-density lipoprotein (VLDL) levels were unchanged. 2. All three classes of lipoproteins isolated from SM plasma had an increased content of triacylglycerol and unesterified cholesterol and decreased cholesteryl ester and phospholipid. 3. The individual phospholipid composition of patient VLDL, LDL, HDL was also altered; the amount of phosphatidylcholine was increased and that of lysophosphatidylcholine decreased. 4. The saturated and monounsaturated fatty acyl content of cholesteryl esters in patient lipoproteins was also significantly increased, and diunsaturated and polyunsaturated fatty acyl content was decreased. 5. When isolated lipoproteins were examined as negatively stained preparations by electron microscopy, the morphology of SM patient LDL was normal but the HDL fraction was abnormal and showed marked heterogeneity of size with the presence of occasional discoidal particles which resembled "nascent" HDL.

Adult↗
PubMed1989

Alterations in the fatty acyl composition of plasma cholesteryl esters in Brazilian patients with hepatosplenic schistosomiasis mansoni.

1. The dyslipoproteinemia commonly occurring in the hepatosplenic forms of schistosomiasis mansoni in Brazilian patients is characterized by low plasma levels of cholesteryl esters and of the cholesterol-esterifying enzyme, lecithin:cholesterol acyltransferase (LCATase, EC.2.3.1.43). 2. In the present study, normal healthy individuals and patients suffering from hepatosplenic schistosomiasis mansoni were compared for the fatty acyl compositions of circulating plasma cholesteryl esters and of those formed in vitro by the action of LCATase on a) the endogenous plasma lipoproteins and b) an excess of lipoprotein substrate composed of heat-inactivated plasma. 3. In patient plasma the proportions of saturated and monounsaturated cholesteryl esters were higher and those of diunsaturated and polyunsaturated esters were lower than in the control group. 4. Similar differences were observed between patients and controls in the proportions of the cholesteryl ester subclasses formed in vitro by the action of LCATase on endogenous plasma lipoproteins. 5. Incubation of fresh normal or patient plasma with excess heat-inactivated plasma as substrate for LCATase produced proportions of cholesteryl ester subclasses similar to those formed during incubation of nonheated aliquots of the appropriate substrate plasma. 6. We conclude that the alterations in fatty acyl composition of plasma cholesteryl esters in patients with hepatosplenic schistosomiasis mansoni do not appear to be a direct consequence of the low levels of LCATase activity in patient plasma.

Adult↗
PubMed1986

An anatomical study of the palmar cutaneous branch of the median nerve.

We present an anatomical study of the palmar cutaneous branch of the median nerve emphasizing its frequency, origin, perforation point at the transverse carpal ligament, point of emergence in the palm, width, length, divisions and innervation territory. For this purpose, fifty cadaver hands were dissected under a stereomicroscope and/or magnifying glass. The origin of the palmar cutaneous branch (PCB) was on the average 4.56 cm proximal to conventionally named "zero point" on the most distal transverse volar wrist crease. Perforation of the aponeurosis occurred on average 0.79 cm from the mentioned point and its emergence in the palm at 0.76 cm. The nerve had an average length of 5.24 cm. PCB's divisions in the palm resulted in a medial branch in 42%, a lateral branch in 92% and an intermediate branch in 100% of the hands studied. In six specimens PCB presented a deep branch which was directed toward the thenar eminence or made communication with the superficial branch of the palmar digital nerve or still penetrated between the first or second metacarpal. In 4% of the cases there was a communicating branch between the superficial branch of the radial nerve and the PCB. These anatomical results should be considered in the evaluation of the best surgical techniques for decompression of the median nerve in the carpal tunnel.

Female↗
PubMed1985

Inhibitory effect of high-density lipoproteins from plasma of schistosomiasis mansoni patients on the binding of normal low-density lipoproteins to cultured skin fibroblasts.

Total high-density lipoproteins (HDL) isolated from the plasma of patients suffering from hepatosplenic schistosomiasis mansoni have an abnormal apoprotein composition. The apoprotein E content is increased and one or two abnormal apoproteins with pI 6.0 and 6.5 are present in patient HDL. Whilst normal HDL have a negligible effect on the binding of 125I-labelled normal low density lipoproteins (LDL) by cultured human skin fibroblasts, patient HDL is inhibitory. It is concluded that the abnormal apoprotein composition of schistosomiasis HDL allows it to bind to the LDL receptor on the fibroblast membrane.

Apolipoproteins E↗
PubMed1985

Nerve cells in the human cavernous sinus.

The present anatomical investigation showed that, in 10 cavernous sinuses of human beings studied, we found neurons with morphological characteristics similar to those found in the autonomic nervous system ganglia. Sometimes these neurons were found isolated alongside nerve fibres; otherwise grouped in ganglia. These cells were more frequent in the middle part of the sinus and in the vicinity of the internal carotid artery and abducent nerve. We also observed a bundle of fibres connected with neurons and bundles of fibres being incorporated to (or leaving?) the abducent nerve.

Abducens Nerve↗
PubMedDate not supplied

Influence of hypoxanthine and other purines on the lecithin:cholesterol acyltransferase reaction in the plasma of rat and other species.

1. Esterification of radiolabelled cholesterol in the plasma of rat, mouse, pig, ox and, to a lesser extent, guinea pig was partially inhibited by hypoxanthine, xanthine and guanine; esterification in human plasma and in plasma from 12 other vertebrate species was unaffected by purines. 2. Esterification of endogenous cholesterol and the formation of lysolecithin in rat plasma were decreased in the presence of purines indicating that it was the lecithin:cholesterol acyltransferase (LCAT) reaction that was inhibited rather than the isotopic equilibration of labelled cholesterol with the endogenous substrate lipoproteins. 3. Maximum inhibition of the LCAT reaction in rat plasma occurred at 1.4 mM hypoxanthine or xanthine; inhibition was not dependent upon the concentration of LCAT or plasma lipoproteins but increased with the amount of lipoprotein depleted rat plasma (LDRP) present in the incubation mixture. 4. Partial inhibition of the LCAT reaction in rat or mouse plasma by purines had no significant effect on the fatty acyl composition of the cholesteryl esters (CE) formed by LCAT. 5. In the presence of heated rat plasma, LDRP or, to a lesser extent, rat high density lipoproteins (HDL) prepared from heated plasma, the LCAT reaction in human plasma was inhibited by hypoxanthine. 6. Rat HDL and LDRP prepared from plasma pre-incubated at 37 degrees C for 4 hr before heating increased and decreased, respectively, the inhibitory effect of hypoxanthine on human plasma LCAT compared with HDL and LDRP prepared from unincubated rat plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗