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Biomedical subjects

S Armendares

Publications and source records attributed to S Armendares.

At least 19 recordsLinked to original sources

Gene frequencies and admixture estimates in a Mexico City population.

Five hundred and ten students of the Universidad Nacional Autónoma de México were tested to determine the distribution of ABO, MN, Rr-Hr blood groups, and serum haptoglobin, albumin, and Factor Bf types. Based on the results we found that the proportion of Indian and White genes are of 56.16 and 43.84%, respectively in the dihybrid model and 2.93, 56.22, and 40.85% for Blacks, Indians, and Whites in the trihybrid one. The present study reveals a higher proportion of Indian genes in the Mexico City population than estimated in previous publications. Reasons why the present results apply to a much larger group of Mexico City mestizos than the previous ones are given.

ABO Blood-Group System

A patient with 44 chromosomes.

A patient with Turner syndrome and a 13q14q translocation is described. Not a single such case had been reported. The principal findings in connection with double aneuploidy in humans are discussed.

Child

Defective monocyte chemotaxis in children with Down's syndrome.

Under-agarose random migration, chemokinesis and chemotaxis of monocytes from 36 patients with Down's syndrome were compared to those of monocytes from 42 healthy, age-matched control children. Random migration of monocytes from patients with Down's syndrome was comparable to that of controls. In contrast, chemotaxis of monocytes from patients with Down's syndrome was significantly decreased (P less than 0.001) when compared to that of controls, even though chemokinesis was significantly increased (P less than 0.001). Age, sex, and physical development of patients with Down's syndrome or of control children included in this study had no apparent effect upon monocyte mobility.

Chemotaxis, Leukocyte

[Human identity].

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Biological Evolution

A 49,XXXYY male.

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Abnormalities, Multiple

Chromosome studies of bone marrow cells from metronidazole-treated patients.

Chromosome studies were performed in bone-marrow cells from thirty nine patients with hepatic or intestinal amibiasis, and/or giardiasis, who had been treated with metronidazole during ten days. There was no significant difference in chromosome aberration frequency between the samples before and after treatment.

Adolescent

Frequency of sister chromatid exchanges in severe protein calorie malnutrition.

Nine children with severe protein calorie malnutrition were studied regarding the frequency of sister chromatid exchanges (SCE's) in peripheral blood lymphocytes. The results showed that there was no significant difference between the number of SCE's in the malnourished children as compared to an adequate control group. An interesting finding was that the proportion of 3rd or subsequent division metaphases found in the malnourished children, was higher and significantly different from that seen in the control group.

Adult

Partial 2p trisomy (p21 leads to pter) in two siblings of a family with a 2p-:15q+ translocation.

Partial 2p trisomy was diagnosed (by the G-banding method) in two sibs with multiple congenital defects. Their father showed a balanced translocation 46,XY,rcp(2;15)(p21;q26) (so the patients were the result of a paternal adjacent-1 meiotic segregation). The clinical features of the two affected cases are compared with other cases previously reported of partial 2p trisomy in order to individualize the syndrome.

Abnormalities, Multiple

Intrafamilial correlation analysis for IgM serum levels.

The IgM serum level was determined in the members of 29 healthy families. The IgM mean concentrations between fathers and mothers and between sons and daughters were significantly different (P less than .01), with higher serum IgM levels in females than in males. Simple linear regression analysis was done for the following intrafamilial combinations: son-father, daughter-father, son-mother, and daughter-mother. Significant correlation coefficients (P less than .05) were obtained in all four combinations, which does not support the X-linked gene hypothesis (i.e., that the X chromosome carries quantitative genes for immunoglobulin M). An alternative explanation for the differences between sexes for IgM serum concentration is considered.

Adolescent

Familial true hermaphorodism in three siblings: plasma hormonal profile and in vitro steroid biosynthesis in gonadal structures.

The in vitro biosynthesis of estrogens and androgens by gonadal tissues of the ovotestes was studied in three siblings with familial true hermaphrodism and correlated with daily steroid and gonadotropin plasma levels. The probands were 15, 13, and 11 years old with normal male phenotype and external genitalia, grade III hypospadias, bilateral scrotal ovotestes, gynecomastia, and no uterus or fallopian tubes. Their karyotypes were 46XX both in peripheral lymphocytes and in gonadal fibroblasts, and no Y chromosome fluorescence was observed. A fusiform biopsy of each gonad was obtained, and the testicular and ovarian structures were excised and incubated for five days at 37 C with 3.8 muCi of 7alpha3H dehydroepiandrosterone, in Eagle's growth media, 95% O2 and 5% CO2. After standard procedures, four extractions with methylene chloride were performed, and the residue was assayed using Sephadex LH no. 20 chromatography. Testosterone (T), delta4androstenedione (delta 4), 5alphadehydrotestosterone (5alphaDHT), estrone (E1), estradiol-17 beta (E2) and estriol (E3) were measured. Also, during 16 consecutive days daily venous samples were obtained, and FSH, LH, E2, progesterone (P), and testosterone (T) were determined. The predominant steroids formed in vitro were estrogens, mainly E1 by either the testicular or ovarian structures. In the 11-year-old subject, the ovotestes were less active than in his oldest siblings. The patterns of androgen production showed that T was the principal androgen formed, followed by delta4 and minimal amounts of 5alphaDHT. The daily plasma hormonal profile resembled more closely a female pattern, specially in the 15 and 13-year-old patients. It is suggested that the ovotestes of these siblings had the enzymatic mechanisms necessary for estrogen and androgen biosynthesis, mainly E1 and T using a preferential metabolic pathway via androstenedione. Furthermore, it seems that the testicular structures had a greater capability to synthesize estrogens than the ovary.

Adolescent

Familial true hermaphrodism in three siblings: clinical, cytogenetic, histological and hormonal studies.

Three affected siblings with the hermaphrodism are described. The propositi showed the following characteristics: male phenotype and gender role, hypospadias, bilateral scrotal ovotestes with palpable nodules, and absence of müllerian structures. The X chromatin was positive and the Y chromatin was negative in the 3 affected subjects. Their karyotype in peripheral blood lymphocytes and in gonadal fibroblasts was 46,XX and no Y chromosome fluorescence was observed. Plasma FSH was elevated in the 2 older patients and plasma LH was elevated only in the oldest. Plasma testosterone was low and plasma estradiol high in the 3 siblings; plasma progesterone was elevated in 2, but normal in 1 sibling. Since some of the clinical characteristics of these 3 affected siblings are not the most common features in the majority of sporadic cases of true hermaphrodism, it is suggested that the presence of all of them may be the first clue for the clinical suspicion of the familial type of true hermaphrodism.

Adolescent