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Biomedical subjects

J Vilches

Publications and source records attributed to J Vilches.

At least 37 records · Page 2Linked to original sources
PubMed1980

Determination of plasma malondialdehyde-like material and its clinical application in stroke patients.

Plasma malondialdehyde-like material (MDA-LM) was evaluated in 138 normal subjects and in a group of 57 stroke patients using a modification of the method of Smith et al. (1976). The basal level of MDA-LM in the control group was 35 mumol/l with a range of 22-50 mumol/l. Values above 50 mumol/l were found in 80% of the patients suffering from subarachnoid haemorrhage, in 68% of those with cerebral thrombosis, and in 17% with transient ischaemic attacks. None of the patients with cerebral embolism, intracerebral haematoma, or lacunar infarct had values above 50 mumol/l. Significant statistical differences were found between the control group and all the patients except those with lacunar infarcts.

Cerebrovascular Disorders↗
PubMed1980

[Hepatocyte changes in experimental iron overloading. An ultrastructural and microanalytic study].

In this paper the ultrastructural changes in hepatocytes which were experimentally induced by oral and parenteral iron overloading in Sprague-Dawley rats fed on a steatogenous U.A.R. 2-13 diet are analysed. The changes in the mitochondria consisted of flocculation, vesiculation and crystolysis. The R.E.G. showed marked phenomena of dilatation degranulation and fragmentation. The lysosomes became more numerous and increased their content of ferric macromolecules. Degenerative nuclear phenomena were also seen. A microanalytic study of the cellular organelles and nucleus was done relating the cellular lesion and the intracellular distribution of the iron.

Animals↗
PubMedDate not supplied

Scanning and transmission electron microscopy of a craniopharyngioma: x-ray microanalytical study of the intratumoral mineralized deposits.

This paper discusses the value of scanning electron microscopy (SEM) and x-ray microanalysis in the classification of craniopharyngiomas. This neoplasm shows epithelial nest, cords of cuboid cells, foci of squamous metaplasia, and microcystic degeneration. SEM reveals that the epithelial cysts are lined with elongated cells that possess numerous microvilli and blebs and that some cysts are lined with polyhedral cells. The microvilli are interpreted as characteristic of the fast growing craniopharyngiomas. A microanalytical study of the calcified areas reveals the presence of magnesium, phosphorus, and calcium.

Calcinosis↗
PubMedDate not supplied

[Post-natal development of interstitial Leydig cells in rat testicle].

The existence of different stages of postnatal activities in Leydig's cells, as demonstrated in hormone studies, appears to be fully admitted. Such occurrence should have repercussions on the population of those elements primarily entrusted with their production, either in the number of elements or their activities. The present article studies Leydig's cells rate in Wistar rats over the postnatal stage, from birth to adulthood. During this postnatal stage, Leydig's cells population does not actually disappear. There is a decrease immediately after birth and up to the age of 21 days when gonadal drop occurs in this species, and from there on a considerable increase takes place for in a two-month period they multiply by ten. On the other hand, it is highly surprising the great speed of testicle growth up to the age of 60 days, reaching maximum size at 90 days. The increase is due to the growth of the tubular compartment.

Aging↗
PubMedDate not supplied

[Relation of prolactin with nodular hyperplasia and carcinoma of the prostate].

The relationship between prolactin in NH and prostate carcinoma has several aspects: under normal conditions, prolactin enhances androgens output, increasing the Leydig cell susceptibility to LH. At the prostate level, it increases testosterone binding to the prostate epithelium and stimulates the conversion of testosterone to dihydrotestosterone. On its own, it decreases prostatic protein degradation and increases the DNA synthesis index. With regard to Nodular Hyperplasia, once its hormone dependency is rated, it also appears to be stimulated by high levels of prolactin. The NH cell cultures with human prostate increase their growth, cell division, as well as the DNA synthesis. The aspects of the prolactin-prostate carcinoma interaction involve considering this hormone as a possible carcinogenic agent, emphasizing the existence of high plasma levels of this hormone in individuals with prostate carcinoma, where any androgen excess is considered a major factor at the genesis of this tumour, and prolactin increases indirectly its testicular synthesis. Also, prolactin itself stimulates the growth and development of carcinomatous human cell lines, increasing its effect in the presence of testosterone. For this reason, controlling this hormone levels becomes an element to have into consideration in the treatment and follow-up of these patients; also, the reevaluation of any drug therapy that, besides the initial goal pursued, does not maintain baseline prolactin levels. The association of anti-prolactin drugs has to be understood as a co-adjuvant therapy when there is androgenic deprivation, never as a single treatment.

Animals↗
PubMedDate not supplied

[Application of transmission and scanning electron microscopy in experimental obstructive uropathy: I. Glomerular lesions].

In this research we use the Electronic Transmission and Sweep Microscope to study the morphostructural modifications undergone by the renal glomerulus in experimental obstructive uropathy. The most significant alterations take place at the level of the basal lamina of the glomerulus, where progressive thickening anf folding occurs. The podocytes display, mainly in the late groups, loss of the digit-shaped character of their secondary prolongations, with shortening and thickening of these. They also take on an anarchic arrangement and are pseudofused to one another, forming a cellular lamina in contact with the underlying basal membrane. These morphostructural changes justify the reduction in glomerular filtration that takes place in obstructive uropathy.

Animals↗
PubMedDate not supplied

[Application of transmission and scanning electron microscopy in experimental obstructive uropathy: II. Tubular lesions].

The morfoestructural changes that appear at renal tubule level in obstructive uropathy consist in a progressive loss of the differentiations in the plasmatic membrane: reduction in the number of apical microvilli and of basal invaginations, which entails a drop in the exchange surface area. Degeneration and cellular necrosis phenomena also exist, with the appearance of cell traces in the tubule lumen. On the other hand, morphological signs of a rapid rate of cellular activity in the tubule cells are displayed. Together with the modifications that take place at basal membrane level these changes give rise to an alteration of tubule dynamics.

Animals↗
PubMedDate not supplied

[Application of transmission and scanning electron microscopy in experimental obstructive uropathy: III. Lesions at the interstitial level].

In experimental obstructive uropathy the renal interstice undergoes profound modifications, from the earliest stages, with the fibroblastic elements adopting a palisade arrangement between the renal tubules and the blood cells. Between these cells there is a marked edema configuring "canals", which could be the morphological image of the tubulovenous reflux described in obstructive uropathy. these routes, which we will call tubule-interstice-vein "canals", since in no case could we verify the existence of a direct communication between the tubule formations and the veins, disappear in animals put down late, where fibro and myofibroblastic elements, round cells and macrophages proliferate. A larger number of fibres and fundamental substance are also found. As a result of these changes, a great alteration in renal architecture takes place.

Animals↗
PubMedDate not supplied

[Embryonary rhabdomyosarcoma of the middle ear. Apropos of a case].

The subject presented for its rarity is a case of rhabdomyosarcoma embryonal ear in girl patient 6 years old. Her clinic first gave a wrong diagnosis of chronic otitis of the middle ear with otorrhea and facial paralysis. A malignant tumour was suspected during the operation. A histopathology study confirmed the diagnosis of rhabdomyosarcoma. A review of the literature is made and details given of how often it occurs, and incidence, histopathology types, treatment and prognosis.

Child↗