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Biomedical subjects

J Valle

Publications and source records attributed to J Valle.

At least 37 records · Page 2Linked to original sources
PubMed1999

Prevention of age-related aneuploidies by polar body testing of oocytes.

PURPOSE: We previously demonstrated that aneuploidy-free oocytes may be preselected by testing the first and second polar bodies removed from oocytes following their maturation and fertilization. The present paper describes the results of the application of the method in 659 in vitro fertilization cycles from patients of advanced maternal age. METHODS: Using micromanipulation techniques, 3943 oocytes were tested by polar body sampling and fluorescent on situ hybridization analysis using specific probes for chromosomes 13, 18, and 21. RESULTS: Fluorescent in situ hybridization results were available for 3217 (81.6%) of 3943 oocytes studied, of which 1388 (43.1%) had aneuploidies; 35.7% of the aneuploidies were of first meiotic division origin, and 26.1% of second meiotic division origin. Most errors in the first meiotic division were represented by chromatid malsegregation. The transfer of embryos deriving from 1558 of 1829 aneuploidy-free oocytes in 614 treatment cycles resulted in 131 clinical pregnancies and 88 healthy children born after confirmation of the polar body diagnosis. CONCLUSIONS: Polar body testing of oocytes provides an accurate and reliable approach for prevention of age-related aneuploidies in in vitro fertilization patients of advanced maternal age.

Adult↗
PubMed1999

Breastfeeding, socio-economic conditions and nutritional status of children younger than 12 months in Brazil.

Taking account of socio-economic determinants such as maternal education and family income, nutritional status and its relationship to breastfeeding and socio-economic conditions were studied in 419 children aged 3-12 months in the city of Niterói in south-eastern Brazil. Data were obtained by sampling a population during a high coverage (90%) vaccination campaign in 1992. After stratifying by maternal educational level, the relative risk (prevalence ratio) for height-for-age (H/A) Z-score < -1 in relation to no breastfeeding was 2.2 (95% CI 1.1-4.2) for families where mothers had been educated for less than 4 years and 0.7 (95% CI 0.4-1.1) otherwise, indicating a significant interaction (modifying effect) between breastfeeding and the control variable (chi 2 = 7.4; p = 0.006). Similar results were found when family income was used as the stratification variable (RR 2.2, 95% CI 1.1-4.3 in the lower and RR 0.7, 95% CI 0.4-1.2 in the higher income stratum; chi 2 = 6.7; p = 0.009). The population-attributable risk fraction indicated that in the age group analysed a reduction of about 40% in the number of children with HAZ < -1 could be achieved in low-income/low-education families by the widespread adoption of breastfeeding.

Brazil↗
PubMed1999

Prepregnancy testing for single-gene disorders by polar body analysis.

Preventive measures for single-gene disorders are currently based on carrier screening in pregnancy and prenatal diagnosis. Although this has been extremely effective for preventing new cases of common inherited conditions, the major limitation is still termination of 25% of wanted pregnancies following detection of affected fetuses. To overcome this important problem, we developed a method for prepregnancy genetic testing that involves DNA analysis of the first and second polar bodies, which are extruded during maturation and fertilization of oocytes. We offered this option to 28 couples at risk for having children with single-gene disorders. Fifty clinical cycles were performed from these patients for the following conditions: 20 for cystic fibrosis, 18 for thalassemia, 6 for sickle cell disease, 2 each for Gaucher disease and LCHAD (long-chain 3-hydroxyacyl-COA dehydrogenase deficiency), and 1 each for hemophilia B and phenylketonuria. Oocytes obtained from these patients using in vitro fertilization procedures (IVF) were tested by a sequential multiplex nested PCR analysis of the first and second polar body to detect the gene involved simultaneously with linked polymorphic markers. A total of 191 of 399 oocytes with predicted genotype were mutation free and preselected for fertilization and transfer. In all but three cycles, one to three unaffected embryos with predicted unaffected genotypes were transferred, resulting in 20 pregnancies, from which 19 healthy children have been born. The follow-up analysis of embryos resulting from oocytes with predicted affected genotype, confirmed the diagnosis in 97% of cases, demonstrating the reliability of prepregnancy diagnosis of single-gene defects by polar body analysis.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1999

Gastric cellular turnover and the development of atrophy after 31 years of follow-up: a case-control study.

OBJECTIVE: Why only some patients colonized with Helicobacter pylori (H. pylori) develop atrophy, a preneoplastic change, is not known. Because gastric mucosal mass is dependent upon a balance between epithelial proliferation and turnover, we hypothesized that atrophy may develop due to increased apoptosis relative to proliferation. METHODS: Gastric epithelial apoptosis was measured by terminal deoxyuridine nucleotide nick end labeling (TUNEL) assay and proliferation by Ki-67 immunohistochemistry in gastric corpus biopsies in a unique cohort of patients followed for 31 yr (1952-1983). Sixteen patients who developed atrophy over this time were selected (cases), with two matched controls, who did not develop atrophy, for each. Apoptosis and proliferation were measured in the corpus biopsies taken in 1952. RESULTS: Cases (N = 16) and controls (N = 32) were well matched for age, sex, initial histology, and severity of H. pylori infection. In the initial (1952) biopsies, 4.3 +/- 1.7 cells (mean +/- SEM) per gland were Ki-67-positive in the cases, compared with 2.1 +/- 0.4 in controls (p = 0.48). 9.2 +/- 2.3 cells per gland were terminal deoxyuridine nucleotide nick end labeling-positive in cases, compared with 6.3 +/- 0.8 in controls (p = 0.29). Proliferation to apoptosis ratios were similar in both groups (cases, 0.38 +/- 0.16; controls 0.39 +/- 0.08, p = 0.37). CONCLUSIONS: Patients who later developed atrophy, initially had mildly (but not statistically significant) increased gastric epithelial cell proliferation and apoptosis, compared with those patients who did not develop atrophy, suggesting increased cellular turnover in the atrophy group. However, in these patients with gastritis, the ratio of apoptosis to proliferation was not a determinant of risk for development of atrophy decades later.

Adolescent↗
PubMed1999

Primary lymphomas of the heart in immunocompetent patients. Presentation of two cases with one 12 year survival. Analysis of surgical implications.

Two primary malignant lymphomas originating in the right heart cavities have been diagnosed and treated in our department: one, with additional right atrial and inferior vena cava thrombosis required emergency thrombectomy, incomplete excision and chemotherapy and survived 12 years, the other with extensive right ventricular infiltration and failure, died from mediastinitis and aplastic anaemia following surgery and chemotherapy. Quick diagnosis and treatment are indicated. If possible, surgery should be avoided.

Contraindications↗
PubMed1998

Aetiology of ovine footrot in Spain.

Four hundred and sixty strains of obligate anaerobes were isolated from 216 cases of ovine foot rot distributed throughout Spain. The predominant species was Dichelobacter nodosus, which was isolated in 168 cases (77.8 per cent). A higher proportion of the strains of D nodosus than of the other strains had elastolytic activity, 118 of the 168 strains degrading elastin. Species belonging to the genus Prevotella were isolated from 96 cases (44.4 per cent). Serotyping of the D nodosus strains showed that serovars A1, A2 and C were the most commonly isolated in Spain.

Animals↗
PubMed1998

Ribotyping of Fusobacterium necrophorum strains isolated from bovine and ovine hepatic abscesses.

A microbiological study was made of 100 strains of Fusobacterium necrophorum isolated from hepatic abscesses in bovine and ovine herds. Differences between the biological activity and ribotypes within the two F. necrophorum subspecies were studied. Conventional methods identified 89 isolates as F. necrophorum subsp. necrophorum and 11 as F. necrophorum subsp. funduliforme. For ribotyping, 50 strains (35 F.n. subsp. necrophorum, 11 F.n. subsp. funduliforme and 4 reference strains) were digested with restriction endonucleases (HindIII, EcoRI and BamHI) and examined after hybridization with digoxigenin-labelled cDNA probe transcribed from a 16 and 23S rRNAs from Escherichia coli. The most discriminating restriction endonuclease enzymes for ribotyping were EcoRI and BamHI. The presence or absence of two distinct band of 5 kb (EcoRI) and 10.5 kb (BamHI) differentiated the two subspecies. This technique also revealed genetic differences between isolates which could be used in the epidemiological study of clinical processes caused by F. necrophorum.

Journal Article↗
PubMed1998

Three births after preimplantation genetic diagnosis for cystic fibrosis with sequential first and second polar body analysis.

OBJECTIVE: The purpose of this study was to determine the accuracy and feasibility of sequential polar body removal and analysis for preimplantation genetic diagnosis of mendelian disorders. STUDY DESIGN: Three couples with risk factors for cystic fibrosis had preimplantation genetic diagnosis with the use of sequential polar body analysis. After stimulation, oocytes were harvested and the first polar bodies were removed and analyzed on the day of aspiration. The following day, after fertilization, the second polar bodies were aspirated. Only embryos known to have inherited the normal maternal allele were transferred. RESULTS: All three couples had successful pregnancies resulting in the births of unaffected infants. CONCLUSIONS: Preimplantation diagnosis with the use of sequential polar body removal is feasible and can prevent the establishment of genetically abnormal pregnancies for couples at risk.

Alleles↗
PubMed1998

Preimplantation diagnosis of common aneuploidies by the first- and second-polar body FISH analysis.

PURPOSE: A low pregnancy rate in in vitro fertilization (IVF) patients of advanced maternal age may be caused by aneuploidies originating from non disjunction in the first or second meiotic divisions. We introduced genetic testing of oocytes by sampling and fluorescent in situ hybridization (FISH) analysis of the first and second polar bodies, to avoid fertilization and transfer of aneuploid oocytes in IVF patients of advanced maternal age. METHODS: Three hundred and sixty-three IVF patients 34 years and older participated in the study. Using micromanipulation procedures, the first and second polar bodies were removed following their extrusion from the oocytes and studied by FISH, using probes specific for chromosomes 13, 18, and 21 to detect oocytes with common aneuploidies. RESULTS: Of a total of 538 IVF cycles, 3250 oocytes were available for FISH analysis, with conclusive FISH results in 2742 oocytes (84.3%). As many as 1102 (40%) of oocytes were predicted to be aneuploid and not transferred. Of 1640 embryos predicted to be normal, 1145 were transferred in 467 treatment cycles, resulting in 107 pregnancies (23%), from which 67 healthy children have been born, 32 pregnancies spontaneously aborted, and 15 pregnancies are ongoing after being confirmed normal by prenatal diagnosis. CONCLUSIONS: Preimplantation diagnosis by first- and second-polar body FISH analysis allows us to avoid the age-related risk of common aneuploidies in IVF patients of advanced maternal age.

Aneuploidy↗
PubMed1997

Recurrent gains of 1q, 8 and 12 in the Ewing family of tumours by comparative genomic hybridization.

Comparative genomic hybridization (CGH) was used to detect copy number changes of DNA sequences in the Ewing family of tumours (ET). We analysed 20 samples from 17 patients. Fifteen tumours (75%) showed copy number changes. Gains of DNA sequences were much more frequent than losses, the majority of the gains affecting whole chromosomes or whole chromosome arms. Recurrent findings included copy number increases for chromosomes 8 (seven out of 20 samples; 35%), 1q (five samples; 25%) and 12 (five samples; 25%). The minimal common regions of these gains were the whole chromosomes 8 and 12, and 1q21-22. High-level amplifications affected 8q13-24, 1q and 1q21-22, each once. Southern blot analysis of the specimen with high-level amplification at 1q21-22 showed an amplification of FLG and SPRR3, both mapped to this region. All cases with a gain of chromosome 12 simultaneously showed a gain of chromosome 8. Comparison of CGH findings with cytogenetic analysis of the same tumours and previous cytogenetic reports of ET showed, in general, concordant results. In conclusion, our findings confirm that secondary changes, which may have prognostic significance in ET, are trisomy 8, trisomy 12 and a gain of DNA sequences in 1q.

Adolescent↗
PubMed1997

Minimum inhibitory concentrations for selected antimicrobial agents against Fusobacterium necrophorum isolated from hepatic abscesses in cattle and sheep.

Minimum inhibitory concentrations for 35 antimicrobial agents against 100 Fusobacterium necrophorum isolates from hepatic abscesses in sheep and cattle were determined. Twelve of the thirteen beta-lactam antibiotics tested inhibited growth of 100% of strains tested. Of the remaining antimicrobial agents, extensive susceptibility was found for: spiramycin, josamycin, lincomycin, tylosin, oxytetracycline, chlortetracycline, rufloxacin, metronidazole, cotrimoxazole, sulfadimethoxine, virginiamycin and fosfomycin.

Animals↗
PubMed1997

Gains, losses, and amplifications of DNA sequences evaluated by comparative genomic hybridization in chondrosarcomas.

Comparative genomic hybridization was used to search for previously unknown gains and losses of DNA sequences along all chromosome arms in 29 chondrosarcoma specimens obtained from 23 patients. Extensive genetic aberrations, with a mean of 6 changes per tumor (range, 1 to 24), were detected in 21 of the 29 samples analyzed (72%). The majority of these changes were gains of whole chromosomes or whole chromosome arms. Gains of DNA sequence copy number were most frequent at 20q (38%), 17p (38%), 20p (31%), 1cen-q24 (28%), and 14q23-qter (28%). High-level amplifications of small chromosome regions were sporadic, detected in only 17% of the samples. The only recurrent high-level amplification, seen in two tumors (7%), affected the minimal common region 12cen-q15. Other amplifications, each encountered only once, involved 1p33-p35, 2p23-pter, 4p, 6p22-pter, 18q12-q22, 19p13.2, 19q13.2, and 20q13.1. Losses of DNA sequences were rare and were most commonly observed at 6cen-q22 (17%) and 9p (17%).

Adult↗