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Biomedical subjects

I Requena

Publications and source records attributed to I Requena.

32 records · Page 2Linked to original sources
PubMed1990

Trichogenic trichoblastoma. An unusual neoplasm of hair germ.

Tumors of hair germ are a very rare group of primary cutaneous neoplasms that have been divided into two groups: epithelial and mesenchymal. Epithelial neoplasms of hair germ are further subdivided into those that are purely epithelial (trichoblastomas) and into epithelial neoplasms with mesenchymal components that may cause inductive changes toward the earliest phase of hair follicle differentiation (trichoblastic fibroma) or a more advanced and complete hair follicle formation (trichogenic trichoblastoma). We herein report an ulcerated trichogenic trichoblastoma whose epithelial and mesenchymal components recapitulated the formation of numerous primitive dermal papillae of the hair bulb because there were numerous strands of small polygonal epithelial cells that delimited areas of a dense and abundantly cellular connective tissue in a hair papilla-like pattern.

Adult↗
PubMedDate not supplied

A silver staining method for the detection of polymorphic proteins in minute bloodstains after isoelectric focusing.

A silver staining method has been developed to study polymorphic proteins in bloodstains after isoelectric focusing. This method is highly sensitive and permits the detection of polymorphic proteins (i.e. alpha 1-antitrypsin, Gc and Tf C subtypes) in bloodstains as small as 0.2 microliter or less. The method is simple and reproducible and can be used after immunofixation. Blood stains can be identified after longer storage periods than is possible by using conventional staining methods.

Blood Proteins↗
PubMedDate not supplied

The isoelectric focusing of keratins in hair followed by silver staining.

An isoelectric focusing method followed by silver staining has been developed for the study of keratins which is as effective as two-dimensional electrophoresis and fluorography for hair species identification. Hair from dogs, rabbits, horses, cows, guinea-pigs, donkeys, sheep and cats were successfully identified. Narrow pH ranges were used to observe heterogeneity in human hair. Although this heterogeneity may be affected by environmental conditions, it may be of use in criminalistics.

Animals↗
PubMedDate not supplied

[Balantidiasis in a rural community from Bolivar State, Venezuela].

Balantidium coli is the etiologic agent of balantidiasis, an infrequent zoonose of worldwide distribution. The objective of the present study was to determine the clinical and epidemiological aspects of balantidiasis in a rural community in the Bolivar State in Venezuela. Fifty persons and 12 pigs were evaluated. Fecal samples were analyzed by direct examination and by the methods of Faust and Willis. The global rate of intestinal parasitoses detected was 88.0% for the human population and 83.3% for the pigs. The prevalence of human and porcine balantidiais was 12.0% (6/50) and 33.3% (4/12), respectively. The disease was only detected in children, all of them with multiple parasites and with clinical manifestations. Deficient environmental sanitation, absence of basic services in the dwellings, low socioeconomic level, and the presence of pigs infected with B. coli are the factors that explain and maintain the conditions favorable to the transmission of balantidiasis in the population studied.

Adult↗
PubMedDate not supplied

[Coma associated with migraine].

INTRODUCTION: Basilar migraine is a particular form of migraine with an aura in which crises of headache are accompanied by symptoms of dysfunction in the vertebro-basilar territory, including alteration of consciousness in the form of stupor or coma. CLINICAL CASES: We report four patients, three men of 14, 17 and 83 years of age and one woman of 21. All had previous histories of migraine and presented with transitory episodes of coma. During the coma, the woman woke up spontaneously with intense bulimia. In the three men, it was seen, on injecting flumazenil, that the state of consciousness and the EEG returned to normal transiently. Neuroimaging studies (CT and MR) were normal in all patients. CONCLUSIONS: Migraine-coma is an exceptional, emergency condition in which structural, infectious, toxic and metabolic pathology of the Central Nervous System should be ruled out. As well as in patients with basilar migraine, the association of migraine and coma may also be seen in patients with familial hemiplegic migraine and CADASIL and MELAS syndromes. It may be that gabaergic mechanisms are involved in the theoretical dysfunction of the ascending reticular activating system causing alteration of consciousness, since in the three patients in whom flumazenil was injected, there was a response.

Adolescent↗
PubMedDate not supplied

[Isolated hemi-ataxia as a sign of mesencephalic lacunar infarction].

INTRODUCTION: Lesions of the dento-rubro-thalamo-cortical pathway may cause homolateral or contralateral hemiataxia, depending on whether they are found above or below the decussation which occurs at the level of the inferior colliculus. Most mesencephalic infarctions causing hemiataxia also show oculomotor involvement with nuclear or fascicular lesions of the third cranial nerves. This was not seen in the case we report. CLINICAL CASE: We describe the case of a diabetic patient with a permanent right appendicular hemiataxia, without oculomotor involvement, caused by a lacunar infarct shown on MR imaging which was situated in the antero-external part of the left superior mesencephalum. CONCLUSIONS: This case helps to clarify the topography of the thalamic radiations of the mesencephalic calotte, including the decussated superior dento-rubro-thalamic pathway to the red nucleus. Involvement of this, situated in the mesencephalic lateral vascular territory causes contralateral hemiataxia.

Aged↗
PubMedDate not supplied

[CT vs MRI in the diagnosis of acute stroke].

70 patients who had suffered an acute stroke (52 ischaemic and 18 haemorrhagic) were studied with CT and MR, performing both techniques during the first week of disease and correlating the findings with the clinical data. MR proved superior in the detection of ischaemic infarcts, specially those in the posterior territory and with a small size; it was also superior to CT in the detection of leukoaraiosis and the demonstration of vascular obstructions. CT failed to detect a small brain stem haemorrhage secondary to bleeding of a cavernoma, while its performance was similar to that of MR in the remaining cases. In all patients with intracerebral haemorrhages, including two who were examined on the first day, an area of increased density was evidenced in the T1 sequences. It is concluded that CT, due to its greater availability and easiness of performance, must be maintained as first choice in acute stroke in order to differentiate haemorrhage from ischaemia, while MR may provide additional information in selected cases.

Acute Disease↗
PubMedDate not supplied

[Syndromes of continuous muscular activity: report of a central case (stiff-man) and a peripheral case (neuromyotonia) associated with neuroborreliosis].

We describe two cases of continuous muscular activity: one which is central (the stiff-man syndrome), and another which is peripheral (neuromiotony), the latter in a patient suffering from diabetic neuropathy and with positive Borrellia burgdorferi serology in the bloodstream, as well as CSF. Both cases reacted favourably to medical treatment. In the first case botulinic toxin was used as a simultaneous treatment for focal pseudodystonia in one foot. Response was good.

Aged↗
PubMedDate not supplied

[Autoscopy and multiple sclerosis].

A female patient with clinically defined multiple sclerosis presented episodes of audiovisual hallucinations in the form of projections of her own body image speaking to her. EEG and EEG-Holter studies were normal. MRI revealed multiple areas of hypersignals in white matter, particularly in both temporal lobes. The episodes remitted with carbamazepine therapy. We postulate that this phenomenon of autoscopy, which is unusual in multiple sclerosis, may be related to a mechanism of ephaptic transmission in the temporal lobe that is inhibited by carbamazepine, or it may be related to seizure.

Adult↗