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Biomedical subjects

R Garza-Chapa

Publications and source records attributed to R Garza-Chapa.

At least 19 recordsLinked to original sources
PubMed1996

Risk estimation of ABO and Rho(D) incompatibility in persons with mono- and polyphyletic surnames in Monterrey, Mexico. Comparison with other Mexican populations.

ABO and Rh(o)(D) blood groups were determined in 3813 males and females affiliated with the Instituto Mexicano del Seguro Social (IMSS) who are residents of the Monterrey Metropolitan Area (MMA) in northeastern Mexico. They were selected by their monophyletic or polyphyletic surnames. The ABO and Rh(o)(D) blood group phenotypes and gene frequencies were determined and based upon these, the risk of incompatibilities was estimated for both marriages (MI) and maternal-fetal incompatibility (MFI). These were compared with those estimated for other populations of residents in the MMA, and in other locations in Mexico, as well as with the two most important ancestral populations, Spanish and Tlaxcaltecan Mexican Indians, with the hypothesis that the percent of risk of ABO and Rh(o)(D) MI and MFI are greater in the population with monophyletic surnames than those with polyphyletic surnames. It was found that for persons with monophyletic and polyphyletic surnames, as well as for the other populations in the MMA and other places in Mexico, their ABO and Rho(D) MI and MFI percent of risk are intermediate to the ones estimated for their ancestry. The percentages of MI and MFI are higher for the persons with monophyletic than for the ones with polyphyletic surnames, other populations from the MMA and those from other locations in Mexico. The risks are higher when the similarity with Spanish increases and are lower when their similarities with the Mexican Indians increase.

ABO Blood-Group System↗
PubMed1995

Orally administered gossypol has no effect on eight hamster erythrocytic enzymes.

The effectiveness of gossypol as an antifertilizing agent is due to the severe injuries or death that this drug produces on spermatozoa and spermatides. Several in vitro and in vivo studies have shown that spermatozoal lactic and malic dehydrogenases are inhibited by gossypol; and that these are more susceptible than the somatic enzymes. Notwithstanding, the in vivo effects on other somatic enzymes have been poorly analyzed. The present study shows that gossypol did not produce toxic effects on eight erythrocytic enzymes of male hamsters that were fed daily with 20 mg of gossypol/kg, for 1, 3, 5 or 10 days. The enzymatic activities analyzed were: adenylate kinase, hexokinase, glucose-6-phosphatase, glucose phosphoisomerase, phosphofructokinase, glyceraldehyde-3-phosphate dehydrogenase, phosphoglyceratokinase and pyruvate kinase.

Administration, Oral↗
PubMed1994

Frequency and origin of G-6-PD deficiency among icteric newborns in the metropolitan area of Monterrey, Nuevo León, Mexico.

829 icteric newborn males were studied in order to have more information about the frequency of the G-6-PD deficiency and its origin in the population of the Monterrey Metropolitan area (MMA), in northeastern Mexico. For each subject information about the maternal grandparents' birthplace (states of Mexico) was gathered. The newborns were grouped into five geographic areas. It was found that the frequency of G-6-PD deficiency is higher in icterics than in normal newborns. The grandparents of the deficient newborns with variant B belonged to the northeastern states of Mexico where more European genetic contribution was present whereas most of the grandparents of the A- deficient newborns were from the gulf coast states, where the genetic contribution was African.

Emigration and Immigration↗
PubMed1994

Relationships by isonymy between persons with monophyletic and polyphyletic surnames from the Monterrey metropolitan area, Mexico.

Three thousand two hundred eleven males and females who resided and were interviewed in the Monterrey metropolitan area in northeastern México were selected for having 1 of 10 common selected surnames as either their patronymic or matronymic name. Five of the names are considered monophyletic and five are considered polyphyletic. Because each individual has two surnames, information about the name complementary to the selected surname was analyzed using isonymy methods (1) to see the effect of immigration on the genetic composition of the population and (2) to determine the isonymy, the relationship by isonymy within and between the persons with monophyletic and polyphyletic surnames. The percentages of the most common complementary surnames, the coefficients of relationship by isonymy of surnames for a selected surname, and the coefficients of relationship between the selected surnames are higher in the monophyletic than in the polyphyletic surnames, indicating that the persons with monophyletic names still conserve some customs of the founders that possibly increase their degree of endogamy. Perhaps these indicators are inversely related to migration, indicating that the monophyletic surnames have been more stable in Monterrey since it was colonized.

Emigration and Immigration↗
PubMed1991

Genetic structure of the populations migrating from San Luis Potosi and Zacatecas to Nuevo León in Mexico.

The Mexicans residing in the Monterrey metropolitan area in Nuevo León, Mexico, were grouped by generation and birthplace [Monterrey Metropolitan Area (MMA), San Luis Potosi (SLP), and Zacatecas (ZAC)] of the four grandparents to determine the extent of genetic variation within this population and the genetic differences, if any, between the natives living in the MMA and the immigrant populations from SLP and ZAC. Nine genetic marker systems were analyzed. The genetic distance analysis indicates that SLP and ZAC are similar to the MMA, irrespective of birthplace and generation. Gene diversity analysis (GST) suggests that more than 96% of the total gene diversity (HT) can be attributed to individual variation within the population. The genetic admixture analysis suggests that the Mexicans of the MMA, SLP, and ZAC, stratified by birthplace and generation, have received a predominantly Spanish contribution (78.5%), followed by a Mexican Indian contribution (21.5%). Similarly, admixture analysis, conducted on the population of Nuevo León and stratified by generation, indicates a substantial contribution from the MMA (64.6%), followed by ZAC (22.1%) and SLP (13.3%). Finally, we demonstrate that there is no nonrandom association of alleles among the genetic marker systems (i.e., no evidence of gametic disequilibrium) despite the Mestizo origin of this population.

Alleles↗
PubMed1989

Variation in the gene frequencies of three generations of humans from Monterrey, Nuevo León, Mexico.

Allele frequencies for the ABO, Rh, MNSs, Duffy, Kidd, Lutheran, P and Lewis blood group systems in 207 persons whose 4 grandparents were born in the Monterrey Metropolitan area (MMA), grouped into 3 generations, were ascertained along with other related population from the MMA, Mestizos from Saltillo, Coahuila and Tlaxcala, and from the populations thought to have contributed to their genetic constitution (native Mexican Indians and Spanish). Genetic admixture and distance estimates were calculated. Gene frequencies of the three generations from MMA are intermediate to those of the ancestral populations, indicating that they are Mestizo but with a genetic structure different from Mestizos of Saltillo and Tlaxcala. Both genetic admixture and distance estimates indicate that the oldest generation exhibits the greatest Spanish influence which decreases in the youngest generation and in the other MMA populations as a result of the immigration from the central states of Mexico.

Blood Group Antigens↗
PubMed1980

Population genetics in the state of Nuevo León, Mexico. II. Genetic markers, frequencies and their possible association with chromosome damage in workers exposed to lead.

In order to find out genetic variability and its possible association with chromosomic damage, we studied the ABO, Rh and MN blood groups as well as the ability to taste PTC, ear lobe type and mid-digital hair, in 77 workers exposed to lead oxides. 23 people who worked near the source of lead (internal control) and 20 people not exposed to lead (external control). From each person a blood sample was taken for chromosome analysis in cultured lymphocytes and for lead determination, at the same time an urine sample was taken for delta-aminolevulinic acid (ALA) determinations; at the same time an urine sample increased chromosome damage, blood lead levels and urinary ALA, were found as compared with both controls. Differences were statistically significant. As for genetic marker frequencies differences were found only for the Rh factor, between the internal control and both the external control and exposed workers. No significant association was found between genetic markers and chromosome damage. Association was observed between blood lead levels, and urinary ALA with some genetic markers like ABO and MN blood groups and ear lobe type.

Chromosome Aberrations↗
PubMed1978

ABO and Rho(D) blood groups in IMSS population in the State of Nuevo León (estimation of simple and double incompatibility frequency in married couples and their offspring).

ABO and Rho (D) blood groups were studied in 61,023 people receiving medical care at the medical units or blood banks of the Instituto Mexicano del Seguro Social in the metropolitan area in the city of Monterrey, Nuevo León, so as to determine the genetical inheritance patterns that control these blood antigens, and that were used in the stimation of ABO and Rho (D) incompatibility in married couples and in births with maternal fetal incompatibility. It was found that IMSS populations, regardless of the medical units, can be considered as part of the same one and are different to those observed in blood banks. From the married couples, 28.58 percent were found to be incompatible with ABO and 7.15 percent with Rho (D); in 2.04 percent of cases, maternal fetal incompatibility had a ratio of 15.63 percent in the ABO group and 5.60 percent in the Rho (D) group. Double incompatibility was found in 0.88 percent of cases. The importance of these facts is stressed, considered as significant data for neonatologists and for those working in maternal fetal isoimmunization clinics.

ABO Blood-Group System↗
PubMed1977

[Chromosome analysis in professional subjects exposed to lead contamination].

Chromosomes were analyzed in cultured lymphocytes of 44 male workers from a lead oxide factory, and from a control group of 15 nonexposed individuals. Lead concentration in blood ranged from 30 to 75 mug/100 ml in exposed subjects and from 15 to 35 mug/10 ml in controls. Length of exposure to lead ranged from one month to 11 years eight months. In subjects occupationally exposed to lead, a significant increase in chromatid and chromosome aberrations was found. The frequency of such findings parallels exposure time to lead.

Adult↗
PubMed1977

[Porphyrins].

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Genetic Counseling↗