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Biomedical subjects

R M Fernández

Publications and source records attributed to R M Fernández.

13 recordsLinked to original sources

Polymorphisms in the promoter regions of FAS and FASL genes as candidate genetic factors conferring susceptibility to endometriosis.

Although the pathophysiological mechanisms leading to endometriosis remain unknown, several hypothesis have been proposed, including a dysregulation of the normal apoptotic process which takes place in the endometrium. One of the apoptotic pathways playing a crucial role in the programmed cell death within the endometrium is the Fas-FasL system. In this study we have performed a case-control analysis in order to evaluate three polymorphisms located within FAS (-1377G>A and -670A>G) and FASL (-843C>T) genes, as susceptibility factors for endometriosis. We have analysed a series of women with endometriosis compared respectively to a group of women without symptoms of the disease, and to a group of confirmed unaffected women. The genotyping of the three variants was carried out by Fluorescence Resonance Energy Transfer (FRET) technology, and statistical analysis was performed using chi2 test with Yates correction. Our results show that the differences in the distribution of the polymorphic variants were not statistically significant when the group of patients was compared to the other groups. Thus, it seems to indicate that the variants here analysed are not involved in the pathogenesis of the disease in our population. However this does not let us to completely exclude such genes as potential candidates for the disease. A complete genetic analysis of the genes involved in the intricate regulatory system of the apoptosis may lead to the identification of susceptibility factors for the disease and a better understanding of its etiology.

Adult↗

Analysis of the involvement of CCR5-Delta32 and CCR2-V64I variants in the development of endometriosis.

Several arguments support the proposal that the cytokine network plays a critical role in the aetiology of endometriosis. Among various chemokines, regulated-on-activation, normal-T-cell-expressed and -secreted (RANTES) and monocyte chemotactic protein 1 (MCP-1) concentrations have been shown to be increased in the peritoneal fluid of women with endometriosis. Some studies have demonstrated that, in the context of endometriosis, these chemokines are involved in apoptosis, angiogenesis and/or chemotaxis. Since the chemokines exert their effects by binding to their receptors, it would be plausible that factors affecting such interactions might play a role in the pathogenesis of endometriosis. Thus we postulated that the genes encoding CCR5 and CCR2, which are the receptors for RANTES and MCP-1 respectively, could be good candidate genes for the disease. We have used real-time PCR and FRET technologies to genotype and evaluate the variants CCR5-Delta32 and CCR2-V64I, as susceptibility factors in a cohort of Spanish women with endometriosis. No differences have been found in the frequencies of the two polymorphisms nor in the haplotype/genotype distribution between cases and controls. These data would suggest the lack of association between these polymorphisms and endometriosis in our population, although they do not permit us to discard completely a possible role of other variants within CCR5 and CCR2 genes in this pathology.

Endometriosis↗

Evaluation of germline sequence variants within the promoter region of RANTES gene in a cohort of women with endometriosis from Spain.

The RANTES (regulated upon activation normal T cells expressed and secreted) chemokine, is known to be expressed in endometriotic lesions in a concentration correlating with the severity of endometriosis. Since it has been widely demonstrated that endometriosis has a genetic basis, we postulated that the gene encoding RANTES could be a good candidate gene for the disease. We have used fluorescence resonance energy transfer (FRET) technology to genotype and evaluate the role of the variants -403G-->A and -28C-->G, located within the promoter region of the gene, as susceptibility factors in a cohort of Spanish women with endometriosis. No differences have been found in the allelic frequencies of both variants nor in the haplotype/ genotype distribution between patients and controls. These data are consistent with the lack of association between these polymorphisms and endometriosis in our population. They do not exclude completely a possible role of other variants within RANTES gene in this pathology.

Adult↗

Germline sequence variant S836S in the RET proto-oncogene is associated with low level predisposition to sporadic medullary thyroid carcinoma in the Spanish population.

OBJECTIVE: The molecular basis of sporadic medullary thyroid carcinoma (MTC) remains elusive. While germline gain-of-function mutations in the RET proto-oncogene cause hereditary MTC, somatic activating RET mutations and loss of heterozygosity of markers in various chromosomal regions representing deletions of tumour suppressor genes, have been described in a variable number of sporadic MTC. A previous report suggested that the presence of a germline variant at RET codon 836 (S836S) was associated with the development of sporadic MTC and, furthermore, that the presence of S836S was highly correlated with somatic RET M918T mutation in the MTC. Thus, we sought to determine if the S836S variant would be associated with sporadic MTC from a completely different population base, that of Andalucia. DESIGN: This is a case-control study to determine whether the presence of RET germline S836S is correlated with sporadic MTC in Andalucia. PATIENTS: Thirty-two patients with sporadic MTC from the Andalucia region of Spain, serviced by our University Hospital, were ascertained throughout the period 1995-99. Sporadic MTC was defined as a lack of personal or family history suggestive of multiple endocrine neoplasia type 2 (MEN 2) and lack of germline RET mutations which define any MEN 2 subtype. A region and race matched cohort of 250 controls was also obtained. MEASUREMENTS: The frequency of the S836S allele was determined in cases and controls and compared using the standard chi-squared statistic and Fisher's exact test. RESULTS: The polymorphic allele frequency at codon 836 in the control population (18/500 chromosomes, 3.6%) differed significantly from the MTC case cohort, 9.3% of case chromosomes (six of 64 alleles, Fisher's exact test, two-tailed, P = 0.043). CONCLUSIONS: Germline RET S836S variant is associated with a two- to three-fold risk of sporadic MTC in the Spanish population, in accordance with a previous study based on German cases. Our observations suggest that this phenomenon might be universal and not limited to Germany.

Adult↗

Helicobacter pylori, hyperammonemia and subclinical portosystemic encephalopathy: effects of eradication.

BACKGROUND/AIMS: An involvement of Helicobacter pylori in the development of hepatic encephalopathy in cirrhotic patients has been proposed, but data confirming such an association are lacking. This prospective study aimed to assess whether ammonia levels and indicators of subclinical portosystemic encephalopathy were influenced by H. pylori status in a series of 62 cirrhotic patients. The effects of H. pylori eradication on such parameters were also investigated. METHODS: Fasting blood ammonia levels, mental state, number connection test, flapping tremor, and EEG tracings were recorded at baseline, and in H. pylori-positive patients (as diagnosed by rapid urease test and 14C-urea breath test) these parameters were reassessed 2 months following eradication therapy. RESULTS: In this series of non-advanced cirrhotic patients, the prevalence of H. pylori infection was 52%. No significant differences were observed between H. pylori+ and H. pylori- cases with respect to fasting venous blood ammonia concentration (47+/-24 vs. 43+/-22 micromol/l) or to the remaining parameters assessing portosystemic encephalopathy. In addition, H. pylori eradication failed to induce any significant variation in either fasting blood ammonia levels (from 45+/-23 to 48+/-26 micromol/l) or neurologic disturbances. CONCLUSION: These results indicate that H. pylori infection is not a major contributing factor to either fasting blood ammonia levels or parameters assessing subclinical portosystemic encephalopathy in patients with non-advanced liver cirrhosis.

Aged↗

Turner's syndrome: a behavioral and cytogenetic study.

This study focused on the behavioral and cytogenetic aspects of Turner's syndrome. We evaluated the behavioral scores by ESPQ, HSPQ, and TAMAI tests. In the cytogenetic study, six different variables were defined by a chromosome image analysis computer system (Applied Imagine) that assessed changes in band organization and the measurement of mean optical density (MOD) in six G-bands (Xp21, Xq12, Xq21, Xq23, Xq25, Xq27). We studied 33 females with Turner's syndrome and compared them with 30 females individually matched for normal karyotype, short stature, age, and education. Significant differences were found between the two groups.

Adolescent↗

[Study of diffuse chronic hepatopathy in the outpatient context].

OBJECTIVE: Description of the general characteristics of patients with Diffuse Chronic Hepatopathy (DCH) in an ABS. DESIGN: Empirical study of a prospective and retrospective type. Site. Primary Care. ABS La Mina. Sant Adrià de Besòs. PATIENTS AND OTHER PARTICIPANTS: All patients diagnosed as suffering DCH since 1984, in line with histological or clinical--morphological criteria accepted in the literature. MAIN MEASUREMENTS AND RESULTS: Using a data base of the centre's morbidity and mortality register, 287 reports of patients over 14 years old defined as having DCH were examined. 222 cases met the established criteria. Most of these were males (68%), and to an even higher proportion in the group with alcoholic etiology (84%), which was the most common cause of DCH (64.4%). There was a lower number of complications and deaths attributable to DCH than in published hospital series. CONCLUSIONS: Among the characteristics of DCH in a natural population using the health services, it is important to note the predominance of compensated forms having a rate of complications and deaths attributable to DCH significantly lower than what was observed in hospital series. This information may be of use in planning activities at the ABS level.

Adolescent↗

[Quality assurance at a health center: 2 years' experience].

In the Primary Care field there is very little experience of organizing a quality control programme that covers all aspects of care. In our centre, at the beginning of 1989, a Quality Control Commission (QCC) was formed with the aim of establishing and coordinating these activities. We describe our two year experience in this report, with special emphasis on the programme's organizational side and the methodological difficulties we encountered while introducing the programme.

Community Health Centers↗

[Ischemic cardiopathy in primary care. A descriptive study].

A descriptive study of ischemic heart disease in a primary care center is reported. From the recording systems 112 patients with IHD (9 of them dead) were identified. The calculated incidence and prevalence rates were 1.9/1000 and 10.9/1000, respectively. There were remarkably high rates of cardiovascular risk factors. The most common forms of presentation were myocardial infarction in males and angina in females. The physicians of the primary care center played a role in the diagnosis in 17% of patients. In addition, the disease was exclusively managed in the primary care center in 29% of patients, most of them over 65 years of age. The role of the primary care physician in the diagnosis and control of this condition is emphasized.

Age Factors↗

Neural tube defects: a study in Puerto Rico.

Recent literature reports an apparent decline in the incidence of neural tube defects throughout the world. A revision of stillbirth certificates and surgical reports of closure procedures for open neural tube defects was done in order to establish the incidence and its trend during a nine year period in Puerto Rico. The current prevalence of the syndrome was estimated using the death certificates in addition to the fore-mentioned surgical reports. Our results indicate that Puerto Rico carries probably the highest incidence of the US territories and that the trend is not declining one.

Cohort Studies↗

[Preventing the recurrence of febrile seizures: intermittent prevention with rectal diazepam compared with continuous treatment with sodium valproate].

Sixty nine children suffering from a first febrile seizure without evidence of neurologic disorder or associated risk factors were randomly assigned to one of three groups: no treatment; intermittent rectal diazepam; or continuous oral sodium valproate. All patients were followed for two years. Periodical controls were performed every three months in order to record febrile episodes, recurrent seizures, and treatment side affects. Rate of recurrent febrile seizures was 16% in control group, and 5.5% in diazepam group. Sodium valproate group showed no recurrences in the follow-up period. The low relapsing rate in control group suggests that prophylaxis should not be established even if it is requested by certain parental attitudes.

Administration, Rectal↗