Search PubMed⌕ Search

Biomedical subjects

C Zavala

Publications and source records attributed to C Zavala.

At least 19 recordsLinked to original sources
PubMed1992

Isolated congenital heart defects in first degree relatives of 185 affected children. Prospective study in Mexico City.

Parents (n = 355) and siblings (n = 313) of 185 index cases (IC) with congenital heart disease (CHD) were cardiologically evaluated. In the consecutive sample (2 years) Mendelian and chromosome syndromes were excluded. Four patients and nine siblings had CHD. The frequency of affection in siblings was 2.6% (8 in 313 siblings). All affected relatives are under medical care at the Centro Médico Nacional Siglo XXI, IMSS. In 10 of the 12 affected relatives found, the type of CHD was discordant from that of the IC. Discordance was found also in 9 of 36 IC with two or more CHD. An interpretation is given: if the mutated gene(s) has its effect in early embryological stages, affected relatives may have any type of CHD, but if the alteration occurs later, concordance is expected to be found. This model contributes also in explaining the remarkable genetic heterogeneity that exists in CHD.

Adolescent↗
PubMed1990

[Histocompatibility antigens and acute vascular purpura].

INTRODUCTION: Some kidney diseases are associated to HLA antigens. Nyulassy found an increase in HLA-B35 in patients with Henoch-Schönlein's purpura suffering nephritis (HSP-N). Our study searched for associations of HLA antigens and anaphylactoid purpura nephritis in Mexican mestizo patients. MATERIAL AND METHODS: HLA-A,B, and C antigens were detected by two-step microcytotoxicity in 22 patients with HSP-N and compared to those of 665 healthy subjects of the same ethnic background. RESULTS: A significant association was found between HSP-N and HLA-Aw19 single (pc less than 0.05) or in haplotype form (Aw19-B35) (pc less than 0.005). HLA B35 alone was associated to HSP-N but only at non corrected level (pc less than 0.05). DISCUSSION: The significant association between HLA-Aw19 and Aw19-B35 and HSP-N may indicate a risk factor in Mexican mestizo patients to develop this case.

Adolescent↗
PubMed1979

Variability between and within laboratories in the analysis of structural chromosomal abnormalities.

The frequency of structural chromosomal aberrations in two samples (AM and PM of the same day) from each of nine normal subjects, cultured in two different laboratories, was studied by six observers. The results were analyzed in order to determine the relative importance of inter- and intralaboratory factors in the variability of chromosomal abnormalities. In addition to the difference in the frequency of the abnormalities between the subjects studied, there were differences due to observers from different laboratories (P less than 0.01), as well as between laboratories (P less than 0.01). These results could be explained in part by insufficient agreement between observers from different laboratories and by differences in the quality of the method used.

Adult↗
PubMed1979

Complex segregation analysis of diabetes mellitus.

Complex segregation analysis was applied to a sample of 12,293 nuclear families each with at least 1 diabetic patient. The families were divided into two groups depending on the proband's treatment: insulin-dependent (IDG) and insulin-independent (IIG). Heterogeneity analysis has revealed a highly significant difference in the IIG group when families were divided into different mating types. The higher recurrence risk was found in the group with affected mothers. Also evidence for a major recessive gene was found in the IGG group, while it was not possible to distinguish between the hypothesis for absence of a major locus and absence of polygenic inheritance in the IDG group. Risks to develop the disease were calculated for a few typical situations.

Adolescent↗
PubMed1978

Intestinal lactase deficiency and milk drinking capacity in the adult.

The milk drinking capacity of 200 adults was determined experimentally and the results correlated with their milk drinking habits and intestinal lactase activity as judged by a lactose tolerance test. Of the group 65.5% were found to have deficient lactase activity and 5.3% experienced severe gastrointestinal symptoms with 250 ml of milk; 28.2% with 500 ml; 26.0% with 750 ml; 15.3% with 1000 ml and 25.2% tolerated the latter amount without difficulty. Of the normal individuals, 92.7% tolerated 1000 ml without symptoms. Intestinal lactase activity seemed to be important in determining the extremes of milk ingestion: four or more glasses per day or no milk ingestion, but had little effect in the intermediate pattern of milk consumption. It is concluded that intestinal lactase deficiency has clinical relevance and should be considered when nutritional supplementation with milk is contemplated.

Adolescent↗
PubMed1977

A glucose 6-phosphate dehydrogenase Gd (-) Castilla variant characterized by mild deficiency associated with drug-induced hemolytic anemia.

Erythrocyte G-6-PD deficiency is an X-chromosome-linked hereditary trait which is common in many ethnic groups. A deficiency of G-6-PD in red cells is often associated with hemolytic anemia. This report defines a new variant designated as Gd (-) Castilla, which is associated with drug-induced hemolysis. The red cell G-6-PD activity of the variant subject is about 20% of normal. The variant enzyme is thermolabile in vitro and it has faster than normal anodal electrophoretic mobility and normal substrate affinity. The hemolytic problem of the subject might be correlated to sensitivity to NADPH inhibition and molecular instability of the variant enzyme.

Adult↗
PubMed1975

Thyroid autoimmunity: increased frequency in relatives of insulin-dependent diabetes patients.

Thyroid antibodies were found significantly more often in insulin-dependent diabetics than in their spouses or in non-insulin-dependent diabetics. The poor correlation between presence of thyroid autoimmunity and duration of disease and the significantly increased prevalence of thyroid antibodies in first-degree relatives of insulin-dependent probands are interpreted to suggest that thyroid autoimmunity in probands with insulin-dependent diabetes is not secondary to diabetes. Since married couples in which both members had thyroid antibodies were not found more frequently than predicted by chance alone, acquired environmental factors are not the sole determinants of familial thyroid autoimmunity in diabetes; it is likely that inherited predisposition is of major importance. Relatives of probands with thyroid antibodies have significantly higher frequency of these antibodies than do relatives of negative probands. This finding suggests that there are several kinds of insulin-dependent diabetes, one of which may be an "autoimmune" disease.

Adrenal Glands↗
PubMed1975

Brachydactyly type B and symphalangism in different members of a Mexican family.

A patient with typical brachydactyly type B is described. By history, 4 generations had some affected members and it was possible to examine a sister and 2 children of the proposita. These individuals in addition to the brachydactyly had symphalangism, an abnormality not previously described in association with brachydactyly type B.

Adult↗