Search PubMed⌕ Search

Biomedical subjects

J Granados

Publications and source records attributed to J Granados.

At least 91 records · Page 5Linked to original sources
PubMed1994

HLA-B alleles and complotypes in Mexican patients with seronegative spondyloarthropathies.

OBJECTIVES: To analyse major histocompatibility complex (MHC) haplotypes in Mexican mestizo patients with seronegative spondyloarthropathies (SSpA) and normal controls, to discover if there are other antigens, besides B27, in the HLA region that might show association with the disease. METHODS: The study included 100 Mexican mestizo patients with SSpA and 200 of their first degree relatives. These groups were compared with 85 ethnically matched controls. The class I and class III MHC antigens were obtained by standard methods. The significance of differences between patients and controls was tested by chi 2 analysis; linkage disequilibrium among the different alleles in each haplotype was estimated by computing delta values. RESULTS: We found a significantly increased frequency of the HLA-B27 antigen (pcorr. = 1 x 10(-5), odds ratio (OR) = 33.4, 95% confidence interval (CI) = 9.3-142.0). In the group of 45 SSpA patients negative for the B27 antigen, independent increased frequencies of HLA-B49 antigen (pcorr. = 0.03, OR = 6.5, 95% CI = 1.5-32.8)) and the FC31 complotype (pcorr. = 0.04, OR = 3.7, 95% CI = 1.2-11.1) were found. Significant delta values were obtained for the [B27;SC30] haplotype (p = 0.0005) but not for haplotypes marked by the FC31 complotype. HLA-B antigens on the homologous chromosome in B27 positive patients were mainly HLA-B51 (18%) and HLA-B60 (16%); however, the observed genotypes B27/B51 and B27/B60 were not significantly different than expected from the allele frequencies alone. CONCLUSIONS: These data suggest that in Mexicans additional genes within the MHC region besides the HLA-B27 antigen, might be related to the genetic susceptibility for developing SSpA. Relevant antigens included the HLA-B49 and the FC31 complotype.

Adult↗
PubMed1994

Recurrent Trichosporon beigelii endocarditis after aortic valve replacement.

Fungal endocarditis of the bioprosthetic heart valve, implanted in a patient without evidence of impaired immunity, is reported. Clinical manifestations of endocarditis appeared 7 years after aortic valve replacement for rheumatic disease and included embolization into the popliteal artery. Trichosporon beigelii was isolated from the cultured fragments of the embolus. Two valve replacements were performed because of recurrent infection during the following 4 years. In spite of prolonged antifungal therapy, the patient died from multiorgan septic involvement.

Adult↗
PubMed1993

Cardiac myxomas: surgical treatment, long-term results and recurrence.

Long-term results of the surgical treatment of cardiac myxomas are not completely understood due to its recurrence. We review our experience in 27 operated cases with a follow-up to 22 years (mean 6.5 years), in order to throw light on results and review the problem of recurrence. One patient had a previous recurrent myxoma. At surgery we resect all the tumors and their attachment bases. We prefer a biatrial approach, ample resection and exploration of all cardiac chambers. Hospital mortality was 3.7% (1 case of associated aortic valve replacement) and late mortality 7%. Long-term results were satisfactory, without recurrences. The postoperative life expectancy of these patients seems similar to that of the normal population, except in cases of recurrence or associated valve replacement. Recurrence is very low (4.7% in 526 cases reported in the literature), except in the case of young patients and recurrent, familial, multiple or complex myxomas. The multigrowth potential of the tumor seems more important than an inadequate surgical resection.

Adult↗
PubMed1992

Diversity and pattern of inheritance of autoantibodies in families with multiple cases of systemic lupus erythematosus.

The pattern of inheritance of autoantibodies in eight families chosen from a pool of 110 families of patients with systemic lupus erythematosus (SLE) is described. In all the eight families at least two members were already affected by SLE. In total, 19 patients and 43 first degree relatives were examined. The inheritance of a large set of antinuclear antibodies (for example, DNA, Sm, RNP, Ro, La, histones) and 16/6 idiotype seemed to be related to some unknown genetic factors but not related to HLA. The presence of numerous antinuclear autoantibodies in the serum of a subject was not necessarily associated with overt disease. The incidence of the 16/6 idiotype among patients and their relatives was low. It is not yet clear whether the 'autoantibody burden' is greater in families with multiple cases of SLE than in families with single cases.

Antibody Diversity↗
PubMed1992

Increased frequency of HLA-DR3 in Mexican mestizo pediatric patients with amebic liver abscess (ALA).

Mexican mestizo pediatric patients with ALA revealed a significantly increased frequency of HLA-DR3 alone, or in its haplotype form HLA-A2, DR3, which confirms our previous observation in adult patients with ALA in the same ethnic group. However, the relative increase in these HLA specificities in pediatric ALA patients when compared to adult patients was not statistically significant, and calls for an enlargement of the population studied.

Adolescent↗
PubMed1991

Immunoglobulin heavy chain constant-region gene polymorphism in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is associated with immunoglobulin allotypes in several ethnic groups. In this study, we investigated the association of a Bst EII immunoglobulin heavy chain constant-region gene restriction fragment length polymorphism with SLE in patients from the US and Mexico. A 3-kb restriction fragment was observed with significantly decreased frequency in randomly selected Mexican SLE patients and in Mexican SLE patients in multiplex families. However, no such association was observed in SLE patients from the US. Thus, the absence of a 3.0-kb Bst EII restriction fragment from immunoglobulin heavy chain constant-region genes provides a marker for SLE in Mexican individuals.

Blotting, Southern↗
PubMed1991

Immunogenetics of human American cutaneous leishmaniasis. Study of HLA haplotypes in 24 families from Venezuela.

Twenty-four families with one or multiple cases of localized cutaneous leishmaniasis (LCL) from an endemic region with the highest incidence of LCL in Venezuela were typed from HLA-ABC, DR, DQ antigens and complement factors. The parental HLA haplotypes segregated at random among healthy and affected siblings but in backcross families significantly higher frequencies of HLA-A28 (p = 0.0018), -Bw22 (p = 0.0122), or -DQw8 (p = 0.0364) were present in affected compared to healthy siblings. HLA-B15 showed a higher frequency (p = 0.0062) among the latter group. Haplotypes Bw22CF31 (p = 0.0076) and Bw22DRw11DQw7 (p = 0.0163) were also significantly more frequent in affected compared to healthy siblings and A2Cw- (p = 0.0445) among the latter. No HLA genetic linkage with a putative LCL susceptibility gene(s) could be demonstrated in this study. A case/control comparison of 26 unrelated LCL patients (one proband from each family) and healthy individuals of the same ethnic origin confirmed the association of HLA-Bw22 (pc = 0.048) and -DQw3 (pc = 0.036) with LCL. The relative risk reached 12.5 for Bw22 and 4.25 for DQw3 with ethiologic factors of 0.17 and 0.64, respectively. HLA-DQw3 apparently makes the major contribution as a genetic risk factor for LCL at the population level.

Female↗
PubMed1991

Increased frequency of HLA-DR3 and complotype SC01 in Mexican mestizo patients with amoebic abscess of the liver.

Our preliminary study (31 patients) of HLA frequencies and amoebic abscess of the liver (AAL) in Mexican mestizos was extended to include 110 patients with this condition. The previously found increase in HLA-B16 was not confirmed, but the frequency of HLA-DR3 was again found significantly increased in patients with AAL when compared to the normal, ethnically matched control population, both in its isolated (35.5% vs 12.7%) and in the HLA-A2, DR3 haplotypic version (20.9% vs 4.5%). Moreover, seven of the 17 HLA specificities that were found to be individually different at P (yet not at PC) level in patients with AAL when compared to the control population, were actually HLA-DR3 containing haplotypes. HLA-DR3 may thus encode a risk factor(s) for AAL, at least in the Mexican mestizo population. Furthermore a significant increase in the complotype SC01 and its haplotypic version SC01, DR4 were identified in 45 non selected patients with AAL when compared to normal controls (31.1% vs 6.7% and 17.8% vs 0% respectively). Even though a relationship between allelic forms of complement components and their function has not been fully established, this complotype could represent a risk factor as well, since complement appears to play a role in host defence against amoebic invasion. Finally, no extended haplotype preference was found in these AAL patients.

Adult↗
PubMed1990

Genetic polymorphism of the human sex hormone-binding globulin: evidence of an isoelectric focusing variant with normal androgen-binding affinities.

Human sex hormone-binding globulin (hSHBG) is a plasma glycoprotein composed of two identical subunits. The protein, which has high affinity for testosterone and estradiol has been purified to homogeneity. In this study we have investigated, on neuraminidase-treated serum samples, the presence of genetic variations of hSHBG by polyacrylamide gel isoelectric focusing (IEF). Based on IEF analyses of 110 serum samples from adult Mexican individuals we have identified two distinct IEF-patterns. The most frequent phenotype (95.45%) was characterized by two IEF-bands with pIs of 6.50 and 6.63, respectively. In five serum samples, a different 4-band pattern with pIs of 6.50, 6.63, 6.70 and 6.76 was identified. Family studies showed that this pattern was genetically determined. The frequency of this variant was 4.55%, and the observed phenotypes were consistent with the expression of an autosomal genetic system. The estimated gene frequencies for both alleles were shown to be in genetic equilibrium. Affinity constants, binding kinetics and serum concentrations of hSHBG from individuals having a 4-band pattern were similar to those obtained in individuals with a 2-band pattern, thus suggesting that the mechanism responsible for the generation of polymorphic variants of hSHBG reported herein did not involve the steroid binding site of the molecule. These findings may be of broad interest, as other serum binding proteins express genetic variants, which may permit their further structural and functional subclassification.

Adult↗
PubMed1990

Aberrant right subclavian artery associated with common carotid trunk. A rare cause of vascular ring.

We have reviewed four cases of incomplete vascular rings caused by the presence of a common carotid trunk from which arose both carotid arteries associated with an aberrant right subclavian artery. The patients were aged between 3 and 9 months. All patients presented with recurrent respiratory tract infections. Three patients showed signs of malnutrition and failure to thrive caused by episodes of bronchial aspiration from extrinsic compression of the oesophagus. One patient presented with dyspnoea induced by feeding and another had stridor. A common carotid trunk associated with an aberrant subclavian artery was confirmed in all cases. No other associated anomaly was observed in any patient. Ligature and section of the anomalous right subclavian artery was performed in all patients. The low incidence of this type of vascular ring, its physiopathological mechanism and surgical management are discussed.

Carotid Arteries↗
PubMed1990

[HLA antigens, complement types, and amebic liver abscess in Mexican mestizos].

The association between parasitic diseases, and antigens of the major histocompatibility complex in man (HLA) has been poorly studied. The only study of the association between the HLA system and amebic abscess of the liver was performed by our group, and revealed a significant increase in HLA-BI6 and HLA-DR3 in patients with amebic abscess of the liver. The present study covered a larger number of patients and controls (110 of each) and it confirmed the association with HLA-DR3, it failed to confirm the association with HLA-BI6.

Adult↗
PubMed1990

Gene frequencies and admixture estimates in four Mexican urban centers.

We studied 202 individuals from the city of Leon in Guanajuato state, 228 from Merida, Yucatan, 220 from Oaxaca, Oaxaca, and 257 from Saltillo, Coahuila, to learn the distribution of the ABO, MN, Rh, and Duffy blood groups, serum haptoglobin, albumin, and factor Bf types, and red cell hemoglobin and glucose-6-phosphate dehydrogenase types. With the gene frequencies obtained, we performed admixture measurements with a maximum likelihood method, obtaining a trihybrid model for black, Indian, and white ancestry with the following proportions: 0.084, 0.513, and 0.403 in Leon: 0.059, 0.512, and 0.429 in Merida; 0.018, 0.676, and 0.306 in Oaxaca; and 0.073, 0.547, and 0.380 in Saltillo. The general pattern has high Indian ancestry followed by white and black ancestry. This pattern is congruent with most other studies performed in Mexico, including the east coast, where Indian ancestry predominates despite a clear increase in the black contribution.

Blood Group Antigens↗
PubMed1989

The frequency of complement receptor type 1 (CR1) gene polymorphisms in nine families with multiple cases of systemic lupus erythematosus.

Low levels of complement receptor type 1 (CR1) on the erythrocytes of patients with systemic lupus erythematosus (SLE) may be acquired or genetically determined. Nine families with multiple cases of SLE were studied using a CR1 probe and restriction fragment length polymorphism analysis, to address this question. The absence of a significant increase in the frequency of a 6.9-kb band (previously shown to be associated with low-level CR1 on erythrocytes) suggests that this genetic marker does not play a major role in determining SLE, either in these families or in SLE patients in general.

DNA Probes↗
PubMed1988

Gene frequencies and admixture estimates in the state of Puebla, Mexico.

Three hundred ninety-three individuals from the Universidad Autónoma de Puebla and its University Hospital were studied to determine the distribution of ABO, MN, Rh-Hr, Duffy, and Diego blood groups; red cell hemoglobin and glucose-6-phosphate dehydrogenase variants; and serum haptoglobins, albumins, and factor Bf types. With the results we estimated that the proportions of black, indian, and white genes are 10.7%, 56.3%, and 33.0%, respectively, in a trihybrid model. Reasons are given as to why the black ancestry may be artifically high, and it is pointed out that independent confirmation with other markers is needed before the figure can be accepted as a true value.

Adolescent↗
PubMed1988

Conservative operation for mitral stenosis. Independent determinants of late results.

A retrospective study was designed to define the independent determinants of late results in 282 consecutive patients operated on for mitral stenosis between 1978 and 1985. A total of 25 variables were investigated by multivariate discriminant analysis for their possible influence on symptomatic outcome, subsequent reoperation, postoperative thromboembolism, and death. All the patients underwent a conservative mitral valve operation. In addition, 25 patients required concomitant tricuspid annuloplasty. The surgical mortality rate was 1.4% and the late mortality, reoperation, and thromboembolism rates were, respectively, 0.14%, 0.80%, and 0.95%/pt-yr. Actuarial probability of complication-free survival at 8 years was 83% +/- 3.7%. Left atrial size on the M-mode echocardiograms, tricuspid annuloplasty, mitral annuloplasty, presence of left atrial thrombus, male gender, and separation of subvalvular apparatus portended a significantly higher likelihood of poor postoperative symptomatic status (p less than 0.0005). Preoperative mild mitral regurgitation, E to F slope on the M-mode echocardiogram, and tricuspid annuloplasty had significant influence on the need for late reoperation (p less than 0.05). Postoperative atrial fibrillation, mitral valve amplitude on the M-mode echocardiogram, preoperative embolism, and residual mitral incompetence had an independent predictive power for postoperative thromboembolism (p less than 0.05). Finally, preoperative atrial fibrillation, preoperative cardiothoracic ratio, postoperative left atrial size, and postoperative atrial fibrillation all influenced the probability of long-term complications. These results suggest that earlier operation should be considered in patients with mitral stenosis, to increase the complication-free survival rate.

Actuarial Analysis↗