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Biomedical subjects

M Peña

Publications and source records attributed to M Peña.

At least 55 records · Page 3Linked to original sources
PubMed1993

T-cell receptor alpha, delta, and gamma chain genes in insulin-dependent diabetes mellitus.

We have studied the genotypic, haplotypic, and allelic distribution of germline Restriction Fragment Length Polymorphism (RFLP) of T-cell receptor (Tcr) alpha, gamma, and delta loci in 75 insulin-dependent diabetes mellitus (IDDM) patients and 84 healthy blood donors as control population. The restriction endonuclease PvuII produces three allelic fragments of Tcr C gamma (TcrCG) gene segment of 16, 13, and 11.3 Kb respectively. Our observations revealed that PvuII/TcrCG RFLP allelic distributions were not significantly different in the IDDM and the control group. However, 85% of IDDM patients carried HLA DR3 and/or DR4 haplotypes, and when comparing these patients with a second group of HLA DR3+ and/or DR4+ healthy individuals, the 11.3 Kb/PvuII fragment of TcrCG gene was found to be associated with IDDM patients (chi 2 = 11.4, P = 0.003). 54.9% of IDDM patients carried at least one 11.3 Kb allele vs. 21% in controls (chi 2 = 10.77, P = 0.004). No significant association was found between RFLP in Tcr, C alpha, C delta, V gamma 9 loci and IDDM.

Adolescent↗
PubMed1992

Delay in diagnosis of intradural spinal tumors.

Fifty-seven patients with primary intradural spinal tumors operated on in North Manchester and Salford between 1978 and 1988 were reviewed retrospectively. The commonest diagnoses were meningioma and nerve sheath cell tumors (neurilemmomas and neurofibromas). The median delay in diagnosis was 2.5 years (range 3 days to 24 years). Fifty-eight percent were initially referred to orthopaedic surgeons and 95% percent to specialties other than neurosurgery. The commonest presenting symptom was back pain, but later neurologic and urinary symptoms came to predominate. Eighty-eight percent are disease-free at a mean follow-up of 5.7 years. Symptoms were partially or completely relieved in the majority of patients. Delay in diagnosis of these tumors arises from failure to consider the diagnosis in patients with longstanding back pain or neurologic problems.

Diagnostic Errors↗
PubMed1992

A receiver operating characteristic (ROC) curve analysis of a model of mental health services use by Puerto Rican poor.

In this study, the contribution of four distinct domains of the Help Seeking-Decision Making model to predicting the use of mental health services is examined. Using a proposed methodology the authors assess the relevance of this model and its domains to mental services planning. The methodology combines logistic regression analysis and receiver operating characteristic (ROC) curves. Logistic regression analysis allows us to examine the individual variables of the model and generate predictions about use. ROC curves allow us to compare and interpret the relative contribution of a predisposing domain, a physical and mental health domain, an enabling-restrictive domain, and an organizational domain in correctly classifying users and nonusers of mental health services. The physical and mental health domain yielded a Somer's D-statistic of 0.7, which corresponds to an 85% correct classification of randomly selected pairs of users and nonusers. The study findings suggest that comparing ROC curves helps to describe and interpret the domains of the model that are relevant for making predictions about who will or will not use mental health services during a 1-year period.

Adolescent↗
PubMed1990

Papillary eccrine adenoma--a light-microscopic and immunohistochemical study.

We report a case of papillary eccrine adenoma. This benign cutaneous tumour had a diagnostic microscopic appearance that consisted of multiple dilated ducts lined by two or more layers of cells. The inner layer often formed intraluminal papillary projections of variable complexity. The lumina were filled by eosinophilic amorphous material. Immunoperoxidase studies showed carcino-embryonic antigen in the luminal border of the ducts, but S-100 protein was absent for tumoral ducts. We discuss the eccrine and apocrine differentiation of this neoplasm on the basis of the immunoperoxidase results. The differential diagnosis includes other cutaneous neoplasms with intraductal papillary proliferation.

Carcinoembryonic Antigen↗
PubMed1989

Fiber and exercise in the treatment of obese adolescents.

The changes in body weight, body fat, lean body mass, and the efficiency index were studied in a sample of 80 obese males and females undergoing four different treatments, using two treatment components: an increase in dietary fiber, and energy expenditure through exercise. In both sexes there was a significant effect of exercise upon body weight and an improvement in the efficiency index. There was also a significant interaction between fiber and exercise in girls, but not in boys. This suggests that the eventual effect of dietary fiber is heightened by exercise, as corroborated by significant differences in some of the groups.

Adolescent↗
PubMed1989

[Scintigraphic method for the study of painful shoulder syndrome: differential count].

Pain may be present in different sites in patients with a painful shoulder syndrome. We compared (scintigraphy) 56 patients with unilateral painful shoulder syndrome and 26 controls. A differential count index (DCI) was used to evaluate painful sites. Values (mean +/- SD) obtained for patients and controls at different sites were: acromioclavicular joint 1.53 +/- 0.33 vs 1.09 +/- 0.08 (p less than 0.005); * 1.30 +/- 0.39 vs 1.07 +/- 0.07 (p less than 0.01); scapular insertion of deltoid muscle 1.61 +/- 0.40 vs 1.10 +/- 0.10 (p less than 0.005); scapular insertion of trapezius muscle 1.31 +/- 0.21 vs 1.08 +/- 0.06 (p less than 0.005). Average number of painful sites for patients 40 years and older was 2.24 vs 1.58 for younger patients (p less than 0.005). Sensitivity and specificity for pain in the various sites was: * 50% and 90%: acromioclavicular joint 85% and 88%; scapular insertion of deltoid muscle 83 and 90%; and scapular insertion of trapezius muscle 71 and 80%, respectively.

Adult↗
PubMed1988

Body fat deposition in adult obese women. I. Patterns of fat distribution.

Fat patterning was studied in a sample of 76 obese women before and after weight reduction by principal components analysis. Circumferences were selected as variables rather than skinfolds because circumferences correlated more highly with body composition determined either by total body water or total body potassium. A separate sample of 136 males and females, measured once, was employed to validate the results. The validation sample yielded similar findings. Two significant components were found, the first contrasting upper and lower fatness and the second trunk and extremity fatness. Waist circumference was the best predictor of upper-body fat patterning. For the lower body, thigh circumference loaded more highly than did the iliac crest circumference. Arm circumference did not contribute significantly to upper-lower fat patterning.

Adipose Tissue↗
PubMed1988

Body fat deposition in adult obese women. II. Changes in fat distribution accompanying weight reduction.

This study examined changes in body fat distribution in 68 women who lost an average of 12.3 kg from an initial weight of 103.6 kg. Weight reduction was accompanied by a small but statistically significant reduction of 1.2% in the waist-to-hip ratio, suggestive of a reduction in upper-body obesity. Subjects with greater upper-body obesity tended to achieve greater reductions in the waist-to-hip ratio. Changes in five circumference measures were highly correlated with losses of fat and showed that subjects with lower-body obesity tended to lose large amounts of fat from both their upper and lower fat depots while subjects with upper-body obesity lost fat primarily from their upper depots. Women with lower-body obesity tended to lose more total body fat than did women with upper body obesity (r = -0.26, p less than 0.04).

Adipose Tissue↗
PubMed1985

Borderline-tissues as sites of antigen deposition and persistence--a unifying concept of rheumatoid inflammation?

In organs of rheumatoid inflammation avascular tissue is nourished by perfusion either directly from the blood stream or by neighbouring blood vessels (borderline-tissue). An open question remains whether this borderline-tissue promotes only the known antigen persistence, or also the first deposition of the pathogenetically important microbial antigen, and subsequently a deposition of immune complexes. The three markers (carbon, latex, and living bacteria) used in this study led to nearly the same pattern of deposition in two groups of organ systems: Organs with clearance function belonging to the mononuclear phagocyte system (MPS); organs with borderline-tissues: joint, kidney, artery, heart valve, and eye. This deposition at the borderline can be observed best in areas of the joint where highly vascularized tissues are adjacent to avascular tissues nourished via perfusion: perichondrium, peritendineum, periosteum, and endo- and perimysium. These localisations of particle deposition correspond exactly with the intraarticular predilection sites of chronic rheumatoid inflammation in man and animals. Our results indicate an easier settlement of corpuscular material in these localisations, which at the same time are unable to eliminate such substances, unlike the organs of the MPS. Our studies seem to support the theory of pathogenetic importance of the borderline-tissues as a localizing factor in the perpetuating rheumatoid inflammation.

Animals↗
PubMed1984

[The scientific work of students: its role in the formation of health professionals].

This article describes the results of 16 years of experience in the scientific development of students of the medical sciences in Cuba, particularly those of the old Faculty of Medicine of Havana University, today the Superior Institute of Medical Sciences. It describes the different intra- and extracurricular forms that this activity can take, with emphasis on the favorable experience built up in the so-called Scientific Working Groups associated with the research projects of faculty members. The article highlights the educational effect of this practice and the need to make it a required and evaluated activity on the curriculum and at the same time that it be given moral and material encouragement. In view of the demands imposed by the scientific and technical revolution, it is felt that scientific work contributes to the development of abilities, attitudes and aptitudes for creative work and for the acquisition of knowledge needed by every university graduate, and is also useful in the selection of future researchers and teachers. The article also underscores the part played by student organizations in the successful conduct of scientific work by students and in its disclosure through their periodical.

Cuba↗
PubMed1984

[Strategy for the formation of human resources in biomedical basic sciences].

The author describes the strategy followed in the Higher Institute of Medical Sciences of Havana for manpower training in basic biomedical sciences. This strategy is based on the Government's general policy for scientific development, and has resulted in the establishment of a network of centers of higher education and research institutes employing more than 3,800 professional and technical staff. Four-year specialization courses have been devised for physicians and dentists, and master's programs for which nonmedical professionals may apply. A system for the obtaining of scientific degrees has been structured together with an extensive program of graduate courses and training. The author comments on the excellent results obtained from the planned, efficient use of bilateral agreements with institutions in other countries and of the possibilities for training and qualification of specialists, the experience in which has already been offered to less developed countries.

Cuba↗
PubMed1980

The influence of physical exercise upon the body composition of obese children.

Thirty-seven obese children 8 to 14 years of age were given a diet 115 kJ/kg of ideal weight for height and were distributed in two groups. One group was under normal ward conditions and the other underwent a physical exercise programme. Body weight, the percent of ideal weight referred to height, percent body weight, and absolute body fat were determined before and 15 days after both therapeutic regimes. The results revealed significant differences in the reduction of these parameters (p < 0.001). When comparing the two groups, only the reduction of percent body fat displayed a significant difference (p < 0.02), showing a greater reduction in those who had performed physical exercise.

Adolescent↗