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Biomedical subjects

V Alvarez

Publications and source records attributed to V Alvarez.

138 records · Page 8Linked to original sources
PubMedDate not supplied

[Pneumocystis carinii pneumonia: laboratory diagnosis].

We worked with 51 samples, 7 bronchoalveolar lavages (BAL) and 44 sputa (S) of 31 AIDS patients with clinical and radiographic symptoms compatible with Pneumocystis pneumonia. With the aim of finding a specific sensitive methodology for the diagnosis of Pneumocystis carinii, we evaluated 4 coloration techniques (silver methenamine, its modification without gold chloride, toluidine blue and Giemsa). 35% of the patients studied were positive. P. carinii were observed in 18% of the 44 sputa. We observed that the analysis of a single sputum sample (S) has a very low sensitivity and that the processing of two or more samples is necessary since only one of the 14 patients who had sent a single sample was found P. carinii positive, while in the remaining ten who had sent more than one (S) sample, the microorganism was detected in 50%. 4 of the 7 BAL were positive. 4 BAL were preceded by the analysis of an (S) sample: in two cases the results were negative while BAL allowed us to make the diagnosis, thus demonstrating its greater efficacy. To enhance sensitivity each sample was centrifuged until exhaustion and 10 slides were prepared for coloration with the final sediment. The four techniques employed were specific and all the Pneumocystis pneumonia patients responded to the treatment. Silver methenamine, its modification without gold chloride, and toluidine blue were very sensitive, in contrast to of Giemsa. The stain to be chosen is either silver methenamine, or its modification, because both achieve the best contrast, allowing optimum P. carinii identification. We suggest the implementation of some of these techniques in laboratory routine.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Intolerance to sodium metabisulfite in children with steroid-dependent asthma.

Oral challenge tests were carried out with sodium metabisulfite solution doses of 5, 10, 25, 50 and 100 mg, dissolved in 20 ml of citric acid, and administered to 20 children aged 7-14 years with steroid-dependent bronchial asthma. A single-blind challenge protocol was performed initially and the positive responses were confirmed by double-blind challenge. Initially, 6 of 20 presented a positive reaction, confirmed in 4 of 20 by double-blind challenge. Only 1 child was clinically suspected of exhibiting intolerance to this agent. The prevalence of the challenge test using sodium metabisulfite in children with steroid-dependent bronchial asthma was 20%.

Adolescent↗
PubMedDate not supplied

Serotonin gene polymorphisms in patients with panic disorder.

INTRODUCTION: The objective is to investigate the possible association between four serotonin gene polymorphisms (T102C, A-1438G, 5-HTTLPR and VNTR-5HTT) and panic disorder (PD). PATIENTS AND METHOD: 92 PD outpatients (DSM-IV criteria) and 174 healthy volunteers from Asturias (control group) were included. Polymorphisms were determined after polymerase chain reaction amplification followed by digestion with restriction enzymes and electrophoresis on an agarose gel. RESULTS: Both 5-HT2A polymorphisms are in complete linkage disequilibrium in our population. No statistically significant differences in genotype frequencies of serotonin gene polymorphisms (T102C, A-1438G, 5HTTLPR and VNTR-5HTT) were found between patients and control subjects. Allele frequencies did not differ between both groups. No differences were found according to gender. CONCLUSIONS: The polymorphisms studied were not associated with PD in our population. However, larger patient samples are necessary to confirm or reject these findings.

Adult↗
PubMedDate not supplied

Short electropherotype rotaviruses isolated longitudinally from a cohort of Mexican infants.

Stool specimens obtained longitudinally during the first year of life of a cohort of 75 rural infants were tested for the presence of rotavirus with an enzyme-linked immunosorbent assay. Thirty four infants showed the presence of rotaviruses during the first year of life. Only 41% of these episodes were associated with diarrhea. Extraction of rotavirus RNA was still possible in 12 of 34 stool samples, ten of them obtained during episodes of associated-diarrhea. Electropherotyping of these rotavirus showed that nine had a short electropherotype. One diarrheal and two asymptomatic samples had a long electropherotype. Subgrouping the viruses with monoclonal antibodies showed that five of the nine rotaviruses with short electropherotype belonged to subgroup I, and two of the three with long electropherotype belonged to subgroup II. The rest of rotaviruses could not be subgrouped. This study confirms the prevalence of only few rotavirus strains in any defined geographic region over a specific period of time, in this case, a rotavirus with a short electropherotype.

Cohort Studies↗
PubMedDate not supplied

[Study of the bronchial provocation test with Alternaria in the diagnosis of childhood asthma: sensitivity, specificity, reproducibility].

The results of the cutaneous tests with fungus, and the repercussion of the fungal allergens in asthma via inhalatory route has been a controversial subject for many years. The lack of characterization, purification and standardization of the allergens make the results of the cutaneous tests highly variable. The diagnostic value of the bronchial provocation test (BPT) in asthma, associated with suspicious fungal hypersensitivity, correctly performed with adequate controls and concentrations of non-irritant fungal allergens has been emphasized by various authors. The motive of the present study to demonstrate, by means of the BPT with Alternaria, if the lung is the target organ of hypersensitivity demonstrated by cutaneous tests and RAST, comparing the obtained results by the Score of FOUCARD (fig. 1), with the result of the inhalatory test. The specificity and reproductibility of the BPT was likewise verified according to the employed allergen and its non-unspecific irritant concentrations to the airway. Twenty patients of both sexes, with ages ranging between 7 and 14 years, distributed in two groups, were studied and diagnosed as having bronchial asthma. Group I: Fourteen patients diagnosed with asthma, for hypersensitivity to Alternaria with Score of FOUCARD equal or greater than 5 (Table I). Group II: Control group composed of 6 patients with negative allergological findinds to Alternaria with bronchial hyperreactivity demonstrated in for cases by BPT positive against Dermatophagoides and in two cases with positive methacholine test (PC20 less than 8 mg./ml.). The inhalation of the allergen was performed following the described method by Cockcroft.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[Factors modifying late bronchial response in the bronchial provocation test in asthmatic children].

When the test of bronchial provocation with inhalant allergens is performed in atopic asthmatics, we may find an immediate response (IR), a late response (LR) or a dual response (IR-LR). The immediate response occurs between 10 to 30 minutes after the allergenic exposition and it is resolved spontaneously in about one to two hours. A proportion of these patients, estimated around 47-73% presented a LR. The LR is manifested 3 or 5 hours after the inhalation test, maximum at 6-12 hours and may persist until 24 hours. The late response serves as a clinical model of asthma because the bronchial response is more prolonged and severe than the immediate response. This is best controlled with corticosteroids while bronchial reversibility is difficult with sympathomimetics only, a fact commonly observed in the natural course of asthma. The early response was observed to be in relation with multiple factors more predictable than the late response. The object of this work was to evaluate if the LR was related with factors such as the degree of obstruction previous to the test, the intensity of immediate bronchial response and the maximum dose of inhaled allergen. The present study was performed in 34 children of both sexes with ages ranging between 6 and 14 years, diagnosed with bronchial asthma caused by Dermatophagoides (26 patients), and Alternaria (8 patients) through the score of Foucard with positive bronchial provocation test with the allergen. The BPT was performed according to the method described for Cockcroft, utilizing a continuous pressured nebulizer, inhaling for two minutes at current volume. We employed the De Villbis 646 model nebulizer with flow of air at 6 l/min and output at 0.13-0.16 ml/min. The inhaled concentrations of allergen progressively increased by ten fold, in Dermatophagoides 0.01; 0.1; 1 and 10 BU/ml, and for Alternaria 1/1,000,000, 1/100,000 and 1/10,000 P/V. Ten minutes after each dose a spirometric function with pneumoscreen Jaeger was performed. If the FEV1 was decreased by 20% from the control value, we considered the IR positive. The late response was evaluated through an hourly control of the peak respiratory flow rate (PEFR) with a Mini Wright within a 24 hours period after the test, respecting nocturnal sleep. We considered positive (LR) if PEFR fall was equal or superior to 40% of the basal value and the presence of bronchial symptoms.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMedDate not supplied

Lepidoglyphus destructor acarus in the urban house environment.

To assess the presence of Lepidoglyphus destructor in the household environment of sensitized children living in an urban environment, samples of house dust were collected at the homes where two groups of patients were living, as well as in two bakeries in the city of Valencia, which were taken as a reference. Patients were divided into two groups. Group A included atopic children suffering from rhinitis and/or asthma, who were sensitized to L. destructor, as proven by prick test and specific IgE (CAP). Group B included children with the same features as those included in Group A, who were sensitized to Dermatophagoides pteronyssinus, with prick and CAP tests showing no significant sensitization to L. destructor. The samples of dust were analyzed, and the amounts of Der p I, Der f I, Der II and Lep d I per gram of dust were assessed through a solid-phase ELISA with monoclonal antibodies. In Group A, all patients but two showed a sensitization to D. pteronyssinus by prick test and serum IgE. At the homes of the patients from both groups, significant levels of Dermatophagoides were found. In Group A, only three houses showed levels of L. destructor which were comparable to those found in bakeries. Lep d I was not found in the houses of Group B patients. This means that a sensitization to L. destructor, as assessed with full extracts, is not always an indicator of its presence at the patient's house environment; it may rather refer to cross-reactivity to Dermatophagoides. Thus, availability of the main antigen Lep d I seems necessary to increase the specificity of the allergologic study.

Adolescent↗
PubMedDate not supplied

Multiple endocrine neoplasia type 1 (MEN1): LOH studies in a affected family and in sporadic cases.

Multiple endocrine neoplasia (Menl) is an autosomai dominant hereditary trait characterized by tumors of endocrine tissues. The MEN1 gene maps to chromosome llql3, has been recently isolated, and encodes a protein termed menin that is ubiquitously expressed. This gene is likely to be a tumor suppressor gene, with tumors developing after the inactivation of both copies of the gene in a single cell. In agreement with this, 11q-deletions (loss of heterozygosity) are frequently found in neoplasms from MEN1 patients. In this study, DNA from family-members was extracted and analysed for 10 microsatellites flanking the MEN1-gene on chromosome 11q. SSCP was used to determine the presence of MEN1-mutations in several patients. DNA was extracted from paraffin blocks containing tissue from 10 parathyroid tumors (4 familial and 6 sporadic) and 2 gastrinomas (both from patients of the Men1-family). LOH was determined by comparing the autoradiographic patterns of several markers between the normal tissue and the malignant tissue counterpart. All the affected individuals in the MEN1-family shared one haplotype, not present in the healthy individuals. We searched for mutations at the MEN1 gene (SSCP-analysis) in several affected members. An SSCP-mobility shift was found at exon 9, and direct sequencing showed that this corresponded to a common polymorphism at codon 418 (GAC/GAT), LOH, a genetic alteration characteristic of genomic regions containing tumor suppressor genes, was found in all the parathyroid tumors, but not in two gastrinomas. SSCP-analysis of the MEN1-exon 9 polymorphism showed that LOH included the MEN1-gene in the informative parathyroid tumors. In conclusion, LOH at 11q is frequent in Menl-parathyroid tumors, either sporadic or familial, and the deletion involves the MEN1-gene. In contrast, the two gastrinomas did not show LOH, indicating the existence of a second mutation other than the MEN1-deletion in these tumors. Our data suggest that the mechanism that drives tumorigenesis in Menl either familial or sporadic, is influenced by the tissue context.

Adolescent↗