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Biomedical subjects

N Olivares

Publications and source records attributed to N Olivares.

At least 19 recordsLinked to original sources
PubMed2004

HLA-DQB1, -DQA1, -DRB1 linkage disequilibrium and haplotype diversity in a Mestizo population from Guadalajara, Mexico.

HLA-DQB1, -DQA1, and -DRB1 genes were typed by polymerase chain reaction with sequence-specific primer (PCR-SSP) in 159 healthy volunteers from 32 families living in Guadalajara, Mexico. Three-locus genotype data from all family members were used to infer haplotypes in 54 unrelated individuals of the sample, from which estimate of segregating haplotype frequencies and linkage disequilibrium (LD) between loci were computed. Genotype distributions were concordant with Hardy-Weinberg expectations (HWE) for all three loci, and allele distributions were similar to the ones observed in other Latin-American populations. Of the 56 distinct three-site (DQB1-DQA1-DRB1) haplotypes observed in the sample, the five most common (i.e., with frequencies of five counts or more) were: *0302-*0301-*04, *0201-*0201-*07, *0301-*0501-*14, *0402-*0401-*08, and *0501-*0101-*01. These common three-locus haplotypes also contributed to the majority of the significant two-locus linkage disequilibria of these three sites.

HLA-DQ Antigens↗
PubMed2001

Effect of exogenous melatonin on hepatic energetic status during ischemia/reperfusion: possible role of tumor necrosis factor-alpha and nitric oxide.

BACKGROUND: This study was designed to determine if the very potent antioxidant melatonin is able to reduce organ damage and improve energetic status in an in situ liver ischemia/reperfusion model. MATERIALS AND METHODS: Total hepatic ischemia was induced in rats by occlusion of the hepatic artery, portal vein, and bile duct. A portojugular shunt was inserted. After 60 min of ischemia, reperfusion was established for a period of 120 min. Rats were assigned to one group receiving systemic melatonin administration or to another receiving only normal saline. Variables were observed at preischemia, after 60 min of ischemia, and at 30, 60, and 120 min of reperfusion. RESULTS: Energy charge, measured as the arterial ketone body ratio, showed higher values in the melatonin group during the first 60 min of reperfusion. Rises in plasma nitrite, tumor necrosis factor (TNF)-alpha, aspartate aminotransferase, alanine aminotransferase, lipid peroxidation products, and inducible nitric oxide synthase (iNOS) expression were less severe with melatonin. Linear regression analysis demonstrated a significant correlation between nitrites and arterial ketone body ratio (R(2) = 0.2454). Bile production was higher with melatonin. Seven-day survival rates were 52% for control, 80% for melatonin, and 100% for sham groups. CONCLUSIONS: Exogenous melatonin is capable of preserving the functional and energetic status during ischemia/reperfusion which is associated with reduced concentrations of TNF-alpha and inhibited expression of iNOS and NO production. This improvement may be due to an adequate preservation of the hepatic mitochondrial redox status.

3-Hydroxybutyric Acid↗
PubMed2001

[Indoor air pollution in a zone of extreme poverty of La Pintana, Santiago-Chile].

BACKGROUND: Indoor pollution can be an important risk factor for human health, considering that people spend more than 60% of their time in their houses. AIM: To investigate indoor pollution in a zone of extreme poverty in Metropolitan Santiago. MATERIAL AND METHODS: During 24 h, carbon monoxide (CO), sulfur dioxide (SO2), respirable particulate matter (PM10), polycyclic aromatic hydrocarbons absorbed in PM5, temperature and humidity, were measured in the interior of 24 houses in a La Pintana, Santiago. RESULTS: The higher pollutant concentrations were observed during hours when heating was used, in houses that used coal (mean PM10 250 micrograms/m3, CO 42 ppm, SO2 192 pph) or firewood (mean PM10 489 micrograms/m3, CO 57 ppm, SO2 295 pph). In all houses, polycyclic aromatic hydrocarbons were detected and they came from the interior of the house and not from external filtered air. Coal, firewood and cigarette smoke were important sources of carcinogenic and kerosene and gas were sources of non carcinogenic polycyclic aromatic hydrocarbons. CONCLUSIONS: In the houses studied, the population was exposed to an accumulation of highly toxic pollutants, caused by a lack of ventilation. A high relative humidity also contributed to the growth of biological pollutants.

Adolescent↗
PubMed2000

Reproductive history in mothers of children with neural tube defects.

The reproductive history of 100 women with at least 1 child with a neural tube defect (NTD) has been studied. The data analyzed correspond to the period previous to their first visit to a genetic counseling service. A total of 204 pregnancies resulted in 205 outcomes. Of the 100 sibships, 14 (14%) had more than 1 affected member. The pregnancy was shorter than 28 weeks in 56/205 (27%) of the total outcomes. Of 104 evaluable previous outcomes, 34 corresponded to short pregnancies, positioned before an affected (23/60, 38%), a healthy (2/18, 11%), or an undiagnosed product (9/26, 35%). Short pregnancies subsequent to affected outcomes were also increased. The inter-gestational interval varied according to diagnosis: it was longer in the affected group than in the healthy one (0.1 > p > 0.05) and the subsequent intervals were shorter for the affected group (p < 0.05). An increased number of abortions adjacent to affected offspring and a changing fertility pattern, depending on the product diagnosis, point to an environmental etiological component in this high-risk NTD group of mothers.

Abortion, Spontaneous↗
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

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↗
PubMed1981

alpha, 1-4 Glucosidase activity in human seminal plasma from normal, vasectomized, and subfertile men.

Neutral alpha, 1-4 glucosidase activity was assayed by a spectrophotometric method using p-nitro-phenyl-alpha-D-glucopyranoside as the substrate in the seminal plasma of normal, vasectomized, and oligospermic men. The latter groups showed lower values than the controls. These results suggest that the main source of the alpha, 1-4 glucosidase activity is between the vasectomy site and the tubule, and that the enzyme is related to sperm density or to a spermatogenesis factor.

Glucosidases↗
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

Alumina cream-induced focal motor epilepsy in cats. IV. Thickness and cellularity of layers in the perilesional motor cortex.

Thickness and cellularity of motor cortical layers adjacent to epileptogenic lesions produced by administration of alumina cream (AC) were measured in the brains of 18 cats that were at latent, convulsive, and remissive stages of an experimental model of epilepsy. Sham-operated animals were used as controls. Brains were fixed by perfusion and embedded in paraffin. Sections of motor cortex adjacent to the AC deposit were obtained at constant thickness to measure thickness and cellularity in each cortical layer. A statistically significant reduction in thickness and cellularity was detected in layers 2, 4, and 6, whereas reduction in these aspects was not significant in layers 3 and 5 in the initial stages of the model (latent and convulsive). It is suggested that AC may exert a cytotoxic effect on inhibitory neurons located at layers 2 and 4, to determine an imbalance of intracortical excitability.

Aluminum Hydroxide↗
PubMed1980

Deficient cell immunity and mild intermittent hyperaminoacidemia in a patient with the Rubinstein-Taybi Syndrome.

A boy aged 2 years 8 months presenting the Rubinstein-Taybi Syndrome (RTS) and a history of recurrent gastrointestinal and respiratory infections was studied. Partial deficient cell immunity and intermittent hyperaminoacidemia and aminoaciduria were ascertained. These findings were interpreted as evidence of phenotypic and probably genetic heterogeneity of RTS.

Abnormalities, Multiple↗
PubMed1980

A simple screening procedure for adenylate kinase, hexokinase and glucose-6-phosphate dehydrogenase deficiencies.

A simple screening procedure for the detection of adenilate kinase (AK), hexokinase (Hx) or glucose-6-phosphate dehydrogenase (G6PD) deficiencies in blood, is described. It consists of two assays : in the first, the ATP formed by blood AK is coupled to Hx and G6PD, and in the second, the glucose-6-phosphate formed by blood Hx is coupled to G6PD. The enzyme activities are visually estimated by the reduction of NADP+ (non-fluorescent) to NADH (fluorescent). The appearance of fluorescence in the first assay indicates that the three enzyme activities are present. The absence of fluorescence could be due to the deficiency of any one of the three enzymes; in this case the second assay used in combination with the Beutler's screening test for G6PD permits the detection of the specific enzymatic deficiency.

Adenylate Kinase↗
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↗
PubMed1979

A simple rapid fluorescent assay for adenosine deaminase activity.

A simple, rapid (2 hours), fluorescent test for the activity of blood adenosine deaminase (ADA) is described. The test which can be performed on both heparinized and dried blood, is based on the conversion of adenosine to inosine and ammonium in the presence of ADA. The enzyme activity is visually estimated by the oxidation of NADH (fluorescent) to NAD+ (non-fluorescent) in a coupled reaction with glutamate dehydrogenase. The disappearance of fluorescence indicates ADA activity in the sample. The advantages are discussed of the use of this test for the study of the autosomal recessive severe combined immunodeficiency.

Adenosine Deaminase↗
PubMed1979

On the deletion 4p16 Wolf-Hirschhorn syndrome.

Two girls (aged 46 and 5 months) and one boy aged 5 months) were studied and found to have the Wolf-Hirschhorn syndrome. Chromosomal complement in all three cases implicated the deletion of the 4p16 band ; in two of them an extra segment of autosomal material was found to be translocated to 4p. Parents' karyotypes were normal. It is concluded that the expression of the 4p16 monosomy is stronger than that of some simultaneous partial trisomies.

Abnormalities, Multiple↗
PubMed1979

Hemolytic anemia caused by glucose-6-phosphate dehydrogenase deficiency.

Results are reported concerning quantitation of glucose -6- phosphate dehydrogenase (G6PD) enzyme activity where in one of the members of a family a clinical diagnosis of acute hemolytic anemia due to G6PD deficiency had been established. In the propositus, G6PD levels were found to be less than 10 per cent thus confirming diagnosis; the same enzymatic deficiency was identified in one of the siblings without a history of hematologic pathology and in a maternal cousin with a history of neonatal jaundice as well as two obliged carriers. Electrophoretical enzyme phenotype was similar to A variant in three affected males. Advantages of prevention and medical care possible with early diagnosis of G6PD deficiency are discussed.

Adolescent↗
PubMed1978

Galactosemia as a result of galactose-1-phosphate uridyltransferase deficiency.

This study was designed to determine the activity of galactose-1-phosphate uridyltransferase enzyme in a family (parents and eight children): four of these with clinical diagnosis of classical galactosemia. In two of them a complete transferase deficiency was found, thus confirming diagnosis; the other two, a pair of dizygotic twins, who since birth up to 11 years of age had been on a galactose free diet, showed enzymatic activity consistent with normal heterozygotes, one of them, and with normal homozygotes, the other. The parents and four brothers had the same enzyme activity levels an those found in heterozygotes for galactosemia. Early diagnosis is of utmost importance in classical galactosemia, and we emphasize this point because patients can be treated with dietotherapy and primary prevention is possible through genetic counseling.

Adolescent↗