PubMed Health⌕ Search

Biomedical subjects

A Miguel

Publications and source records attributed to A Miguel.

At least 55 records · Page 3Linked to original sources
PubMed1986

Phosphoglycerate kinase deficiency: biochemical studies on hair follicles.

A fluorimetric procedure for the determination of phosphoglycerate kinase in single human hair follicles is described. Enzyme studies on different parts of hair follicles after dissection show that the distribution of glucose-6-phosphate dehydrogenase matches that of phosphoglycerate kinase. Glucose-6-phosphate dehydrogenase can therefore be used as a reference enzyme to compensate for differences in hair follicle sizes. It was shown that the variation in the values found in individual hair follicles is improved by relating phosphoglycerate kinase to glucose-6-phosphate dehydrogenase activity. In areas of the world where glucose-6-phosphate dehydrogenase deficiency occurs frequently, an autosomally inherited reference enzyme may be preferred. It is shown that 6-phosphogluconate dehydrogenase is useful in this respect. Upon storage a gradual drop in the activity of all three enzymes was observed, but the rate of decrease was about equal: the enzyme activity ratio was, therefore, almost unaffected for a period of one week. This allows the determination of phosphoglycerate kinase even in mailed hair follicles.

Enzyme Stability↗
PubMed1983

Population screening for glucose-6-phosphate dehydrogenase deficiency on the Baleares.

Two thousand people on the Isles of the Baleares were screened for glucose-6-phosphate dehydrogenase deficiency using a commercially available kit. Among the thousand males tested, five were found deficient; of the thousand women, one had low enzyme activity according to this test. Diagnosis of glucose-6-phosphate dehydrogenase deficiency could be verified using hair follicle analysis on mailed hair samples. The same technique also allowed heterozygotes to be identified unequivocally.

Female↗
PubMed1983

Spanish delta-beta-thalassemia: hematological studies and composition of the gamma-chains in ten homozygous patients.

We report the hematological studies and the composition of the gamma-chains of 10 homozygous delta beta(0)-thalassemia patients belonging to 6 families. These patients showed a mild to moderate chronic hemolytic anemia, morphological changes typical of thalassemia and 100% fetal hemoglobin in their peripheral blood. The homozygous studied synthesized A gamma- and G gamma-chains in approximately equal amounts, and the fetal hemoglobin with a threonyl residue at position 75 is present and accounts for all the A gamma production.

Adolescent↗
PubMed1982

Human hair follicles may be used for population screening of heterozygotes of glucose-6-phosphate dehydrogenase deficiency.

The carrier status for glucose-6-phosphate dehydrogenase deficiency can still be detected with the use of hair follicles after a period up to 10-14 days after plucking, even under conditions of temperature and humidity that are encountered in tropical countries, where the disease is most common. Furthermore, it is shown that the hair colour or age of the donor has no influence on the enzyme activity. As a consequence, the hair follicle is indeed suitable for screening in rural areas since mailing to existing medical centres is possible.

Adult↗
PubMed1982

A comparative study of complex mitochondrial DNA in human lymphocytes transformed by Epstein-Barr virus and PHA.

Mitochondrial DNA (mt DNA) molecules, isolated from normal human lymphocytes, lymphocytes stimulated with phytohemagglutinin (72 h) and a cultured Burkitt's lymphoma cell line, were examined by electron microscopy. Only monomeric forms of mt DNA were found in normal human lymphocytes, whereas in the other cell types, catenated forms were also observed. Unicircular complex forms were apparently absent in all the cell types studied, suggesting that these forms are not a common malignant transformation in human cells. No clear correlation between mitochondrial modifications--as detected by stereological analysis--and the presence of catenated forms could be established. It is suggested that other mechanisms rather than replication of mt DNA would appear to be the mechanism responsible for the formation of these forms.

Cell Line↗
PubMed1982

Extramedullary multiple myeloma. A qualitative and quantitative electron microscopic study.

A case of multiple myeloma with a mediastinal tumor and other unusual findings is described. The findings included the presence of extramedullary tumor masses at multiple sites in addition to the medullary tumor and, more interestingly, the occurrence of pleural and peritoneal effusions. The plasma cells from these effusions were analyzed using stereological morphometric methods. The plasma cells were also cultured and established as a continuous cell line and were studied using the same methods. Our results indicate that there are qualitative and quantitative morphologic differences between the pleural and peritoneal plasma cells. Comparison between plasma cells and cultured cells from the intraperitoneal exudate showed marked morphologic differences. The analysis of these differences indicated that mature plasma cells, when subjected to culture, were transformed into immature lymphoid cells.

Aged↗
PubMed1979

[Hypernatremia and adipsia (author's transl)].

We have studied an infant (female) with a persisting hypernatremia and adipsia, examined for the first time at the age of five months. The funtional test carried out showed an insensibility of the osmoreceptors for very important changes in POsm. carryng with them a lack of response of the ADH. Neuroradiological studies demostrated hydrocephalia secondary to a stenosis of the aqueduct of Silvio. Treatment with chlorpropamide proved effective. The literature is being revised comparing out results with those of other authors.

Chlorpropamide↗