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Biomedical subjects

B Ibarra

Publications and source records attributed to B Ibarra.

At least 55 records · Page 3Linked to original sources
PubMed1983

On the screening for inborn errors of galactose metabolism.

The utility of a simplified diagram of procedures for screening specimens for genetic disorders in galactose metabolism is stressed. Both, early detection and institution of the dietetic treatment are imperative since these inherited disorders have clinical and pathological consequences which can be very severe in galactose-1-phosphate uridyltransferase and uridine diphosphate galactose-4-epimerase deficiencies.

Carbohydrate Epimerases↗
PubMed1982

Phosphoglucomutase: evidence for a new locus expressed in human milk.

Electrophoretic study of phosphoglucomutase (PGM) in human milk revealed different patterns that can be explained by the existence of a locus distinct from the common PGM1, PGM2, and PGM3. One hundred and forty samples were tested and the results showed four different alleles of PGM4 whose frequencies were under Hardy-Weinberg equilibrium.

Alleles↗
PubMed1982

G-6-PD Guadalajara. A new mutant associated with chronic nonspherocytic hemolytic anemia.

This paper describes a new G-6-PD variant designated Guadalajara, which was found in a Mexican boy suffering from chronic hemolytic anemia. The red cell enzyme activity of the subject is about 14%. The mutant enzyme showed rapid electrophoretic mobility, slightly increased affinity for glucose-6-phosphate, slightly decreased affinity for NADP+, moderately elevated utilization of substrate analogues, and normal heat stability, pH curve, and inhibition by NADPH. G-6-PD Guadalajara differs from all previously reported variants and is the first variant associated with chronic hemolysis found in Mexico.

Anemia, Hemolytic, Congenital↗
PubMed1982

Red blood cell sorbitol dehydrogenase deficiency in a family with cataracts.

Sorbitol dehydrogenase (SORD) was quantitatively assayed in a family in which four out of five brothers and their father had bilateral cataracts. Three sibs (two of them with cataracts) and both their father and paternal grandfather had SORD activity of about 25% of the reference values; of the other two affected sibs one had about 50% and the other had 75%; the mother and two paternal uncles had about 75%. These results do not define a clear cataract-SORD deficiency etiopathogenic relationship, nevertheless, they strongly suggest activity polymorphism in human red cell SORD, which would be highly relevant not only to the study of cataracts but of other major complications in diabetes.

Cataract↗
PubMed1982

Sorbitol dehydrogenase (EC.1.1.1.14) polymorphism in human seminal plasma.

Sorbitol dehydrogenase was electrophoretically determined in 173 different samples of human seminal plasma in cellulose acetate as support media. This method permitted the identification of three phenotypes : one with a slow band, one with a fast band and the third with both slow and fast bands. These findings can be explained either by the presence of two alleles at a different SORD locus determining the enzyme in seminal plasma or by the formation of secondary isozymes.

Electrophoresis, Cellulose Acetate↗
PubMed1982

Tetrasomy 9p: clinical aspects and enzymatic gene dosage expression.

A girl aged 13 years and 9 months with a phenotypic appearance of 9p trisomy was studied. Chromosome analysis of peripheral blood lymphocytes revealed a 9p tetrasomy [47,XX,+i(9p)] with no evidence of mosaicism. Biochemical studies corroborate the gene dosage effect for galactose-1-phosphate uridyltransferase. The roentgenological findings were quite similar to those of the 9p trisomy except for hypoplastic and angulated ribs, and malformed vertebral bodies, which are probably exclusive of the tetrasomic state.

Adolescent↗
PubMed1982

Abnormal hemoglobins in Northwestern Mexico.

Blood samples from 9,929 individuals in Northwestern Mexico were assayed for abnormal hemoglobins (Hbs). alpha-thal, beta-thal, beta s and beta c traits, as well as rare abnormal Hbs were observed with variable low frequencies (0 to 0.45%). Eight out of eleven rare abnormal Hbs detected so far have been characterized: Three Hb Riyadh, one Hb J Georgia, one Hb Fannin-Lubbock, one Hb Chiapas and two Hb Tarrant. These results suggest that abnormal Hbs do not constitute a regional public health problem and reflect a wide ethnologic heterogeneity.

Female↗
PubMed1982

Screening for inborn errors of the erythrocyte metabolism in Northwestern Mexico.

Data from a program aiming to the detection of inborn errors of the erythrocyte metabolism (IEEM) in Northwestern Mexican populations are presented. 5,998 individuals were studied and divided in 5 groups: a) 1,022 full-term newborns without jaundice; b) 872 randomly selected full-term newborns; c) 3,243 full-term newborns with jaundice; d) 54 patients with hemolytic anemia, and e) 807 professional blood donors. In groups b, c and d screening for 9 out of 14 IEEM clearly associated with hemolysis was carried out by means of enzymatic fluorescent procedures. In groups a and e only G-6-PD deficiency was investigated. The results suggest that 0.34%, 0.77%, 24% and 0.37% of the individuals from groups b, c, d and e, respectively, have an IEEM. The frequency of G-6-PD deficiency was 0, 0.43%, 1.1%, 30.3% and 0.37% in the males from groups a, b, c, d and e, respectively. The IEEM as a cause of neonatal jaundice seem not to be a public health problem in the studied populations. Systematic screening for: 1) G-6-PD deficiency in newborns with jaundice and 2) IEEM in patients with hemolysis, is recommended.

Anemia, Hemolytic↗
PubMed1981

Meiotic arrest at first spermatocyte level: a new inherited infertility disorder.

Three 46,XY phenotypically male, azoospermic brothers out of thirteen sibs from a consanguineous marriage were studied and found to have a unique pattern of testicular histology with arrest of spermatogenesis at the pachytene stage of primary spermatocytes. Endocrinological evaluation showed elevated plasma luteinizing(LH) and normal to elevated follicle-stimulating (FSH) hormones, positive gonadotropin pituitary response to luteinizing hormone-releasing hormone, depletion of LH and FSH levels by exogenous testosterone (T) administration, normal levels of T and dihydrotestosterone hormones, and elevation of T after stimulation with human chorionic gonadotropin hormone. Electrophoretic assay of lactic dehydrogenase isozymes did not reveal band C4 in semen or testicular tissue. These traits seem to constitute a hitherto undescribed form of infertility in which spermatogenesis arrest at the first spermatocyte level is the main feature. The parental consanguinity suggests autosomal recessive inheritance.

Adolescent↗
PubMed1981

Heterozygosity and homozygosity for the high oxygen affinity hemoglobin Tarrant or alpha 126 (H9) Asp replaced by Asn in two Mexican families.

Two Mexican families from the State of Jalisco have been studied in which 11 members were carriers of Hb Tarrant. Ten subjects were Hb Tarrant heterozygotes producing about 25% of the abnormal hemoglobin. One 9-year-old boy was homozygous for Hb Tarrant. About 50% of his hemoglobin was of the variant type. The heterozygotes had mild erythrocytosis which was considerably more severe in the homozygote. The average P50 value for blood of the heterozygote was 15.1 mm Hg (controls: 22.5 mm Hg) while this value was decreased to 9 mm Hg in the homozygote. The clinical condition of the homozygote is compatible with a mild chronic tissue hypoxia.

Aspartic Acid↗
PubMed1981

Trisomy 22q12 leads to qter: "aneusomie de recombinaison" of a pericentric inversion.

A 10-day-old girl affected with 22q12 leads to qter "pure" trisomy as a consequence of recombination within a maternal pericentric inversion (22)(p13q12) is described. A phenotypical comparative analysis reveals that the proposita's phenotype is strikingly similar to that of the trisomy 22 syndrome. Arylsulphatase-A activity was above normal levels and interpreted to be the result of a triple dosage of the gene, whose localization would be within the 22q12 leads to qter segment. It is concluded that the segment 22q12 leads to qter, rather than band q11 as previously suggested, plays an important role in determining the phenotypical abnormalities which characterize the trisomy 22 syndrome.

Abnormalities, Multiple↗
PubMed1981

Detection of inborn errors of metabolism in 1,117 patients studied because of suspected inherited disease.

Results of screening tests for the detection of inborn errors of metabolism in 1,117 consecutive patients are reported in this work; patients came for a second consultation to the Departamento de Genética, Centro Médico de Occidente, IMSS. Simple qualitative test were made that revealed the presence of abnormal metabolites (amino-acids, sugars, organic acids and mucopolysaccharides) in urine and blood as well as identification tests for variant proteins. Results were positive in 138 patients and test for confirmation and/or specificity were made in all patients; in 35 the following diagnosis and incidence were established: classic galactosemia, 2; glucose-6-phosphate dehydrogenase deficiency, 20; essential pentosuria, 1; hyperphenylalaninemia, 5; blue diaper syndrome, 1; cistinuria 1, and type 1 mucopolysaccharidosis, 5.

Amino Acid Metabolism, Inborn Errors↗
PubMed1980

Autosomal recessive spondylo-epi-metaphyseal dysplasia (Irapa type) in a Mexican family: delineation of the syndrome.

Three sibs from a Mexican mestizo family affected with a spondylo-epi-metaphyseal dysplasia were studied. The clinical, radiological, and genetic findings were similar to those previously described in Venezuelan Indians of the Irapa tribe. The present patients permit confirmation of the syndrome and provide evidence for autosomal recessive inheritance. Genetic drift is postulated.

Adolescent↗
PubMed1980

Study of tuberculous meningitis by CT.

Computed tomography is a very valuable method by which the pathogenic evolution of tuberculous meningitis may be followed, thereby facilitating its differential diagnosis and controlling the efficiency of therapy. The initial miliary tuberculosis in the brain, very often unaccompanied by neurological symptoms, may offer very evident CT images. CT may also demonstrate the fibrogelatinous exudate which fills the basal cisterns and surrounds the arterial vessels which cross this region. Because of this, secondary arteritis is frequent and may be indirectly detected by CT in the form of foci of ischemic infarcts. Tuberculomas may be multiple, and are found equally in the cerebral and the cerebellar parenchyma. These tuberculomas present different images on CT, depending on the evolution of the disease at that moment. Hydrocephalus is a common complication of TM and is caused by a lack of reabsorption of the cerebrospinal fluid, or by an obstructive lesion in the ventricular drainage pathways due to a tuberculoma. This complication is usually easily identified by CT, which, moreover, permits the control of its evolution.

Adult↗
PubMed1980

A simple assay for uridine diphosphate galactose 4-epimerase activity.

A simple fluorescent test for the activity of blood uridine diphosphate galactose 4-epimerase which converts uridine diphosphate galactose to uridine diphosphate glucose is described. The enzyme activity is visually estimated by to reduction of NAD+ (non fluorescent) to NADH (fluorescent) in a coupled reaction with uridine diphosphate glucose dehydrogenase. The appearance of fluorescence indicates that epimerase activity is present in the sample. The usefulness of this test in newborn screening programs for inborn errors of galactose metabolism is stressed.

Carbohydrate Epimerases↗
PubMed1980

Detection of hemoglobin alterations in a sample population in northwest Mexico. Preliminary report.

Blood samples from 1,000 individuals seen at the Instituto Mexicano del Seguro Social in northwestern Mexico were assayed by multiple systems (acid, alkaline and neutral electrophoresis, heat, freeze and isopropanol stability and erythrocytic morphology under hypoxia) to detect hemoglobin (Hb) abnormalities. Two beta-thalassemia heterozygotes (0.2 per cent), five Hb S heterozygotes (0.5 per cent) and three probable new Hb variants (0.3 per cent) were identified. These preliminary results give a general idea of the gene frequencies in this population, but do not yet permit the evaluation of the relative advantage of multiple methodology for the detection of abnormal Hbs.

Female↗