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Biomedical subjects

J Gascón

Publications and source records attributed to J Gascón.

At least 19 recordsLinked to original sources
PubMed2006

Use of a short fragment of the C-terminal E gene for detection and characterization of two new lineages of dengue virus 1 in India.

Here we propose the use of a 216-nucleotide fragment located in the carboxyl terminus of the E gene (E-COOH) and a pairwise-based comparison method for genotyping of dengue virus 1 (DENV-1) strains. We have applied this method to the detection and characterization of DENV-1 in serum samples from travelers returning from the tropics. The results obtained with the typing system correlate with the results obtained by comparison of the sequences of the entire E gene of the strains. The approach demonstrates utility in plotting the distribution and circulation of different genotypes of DENV-1 and also suggests the presence of two new clades of Indian strains. The integration of the method with an online database and a typing characterization tool enhances its strength. Additionally, the analysis of the complete E gene of DENV-1 strains suggested the occurrence of a nondescribed recombination event in the China GD23-95 strain. We propose the use of this methodology as a tool for real-time epidemiological surveillance of dengue virus infections and their pathogenesis.

DNA, Viral↗
PubMed2005

Genetic diversity of Shigella species from different intercontinental sources.

One hundred and twenty three strains of Shigella spp. (mostly Shigella sonnei and Shigella flexneri) were isolated between 1995 and 2000 from patients suffering from traveller's diarrhoea. Seventy nine of them have been typed by digestion of their chromosomal DNA with Xba I and pulsed field gel electrophoresis. Results show a high degree of heterogeneity in both S. sonnei and S. flexneri isolates. This is the first time that the molecular typing of such a high number of geographically unrelated isolates of Shigella sp. is carried out, showing a high level of genomic re-arrangement.

Bacterial Typing Techniques↗
PubMed2005

Histoplasmosis infection in Spanish travelers to Latin America.

The aim of the study presented here was to assess the incidence of histoplasma infection in a cohort of 342 individuals in Spain who had traveled to Latin America for the first time. The histoplasmin skin test was positive in 20% of the travelers, and Central America posed a higher risk for infection than South America (p=0.013). Sleeping outdoors (p=0.031) and the duration of travel (p=0.016) were also identified as significant risk factors. Serological testing demonstrated poor overall sensitivity for detecting infection in the travelers, but for the symptomatic acute cases the results were improved. Histoplasmosis must be considered in patients presenting with fever (odds ratio=3.51 [1.52-8.12]) or cough (odds ratio=4.24 [1.32-13.58]) after visiting Latin America. The results of this study have public health implications and indicate the risks of acquiring histoplasmosis should be included in pre-travel counseling.

Adult↗
PubMed2005

Analysis of the mechanisms of resistance to several antimicrobial agents in Shigella spp. causing travellers' diarrhoea.

Eighty isolates of Shigella spp. (37 Shigella flexneri and 43 Shigella sonnei) from patients with travellers' diarrhoea were studied. Susceptibility tests revealed high levels of resistance, especially to ampicillin (65%), tetracycline (78%) and trimethoprim (75%), and particularly among the S. flexneri isolates. Dihydrofolate reductase 1 genes (dfrA1) were prevalent among the trimethoprim-resistant isolates, while oxa genes predominated among the ampicillin-resistant isolates. Chloramphenicol resistance was associated with production of chloramphenicol acetyltransferase, while nalidixic acid-resistant isolates had a single mutation in the gyrA gene. The results indicate a continuing need for resistance surveillance and rational use of antimicrobial agents.

Ampicillin↗
PubMed2002

Comparative, clinico-epidemiologic study of Schistosoma mansoni infections in travellers and immigrants in Spain.

The study presented here aimed to contrast the marked clinical differences in the presentation of Schistosoma mansoni-induced infection between immigrants and travellers entering Spain from endemic regions, and to elucidate the therapeutic implications of these infections. A total of 200 African immigrants and 80 travellers with schistosomiasis were included in the study. Among the immigrants, 25 patients were diagnosed with Schistosoma mansoni infection; 15 presented with nonspecific symptoms, and 10 were asymptomatic. Hepatosplenomegaly was observed in nine. Among the travellers, 14 were diagnosed with Schistosoma mansoni infection; four were asymptomatic, four had Katayama syndrome, four had diarrhoea, and two had prostatitis. All of the patients were treated with praziquantel. Patients diagnosed with Katayama syndrome received praziquantel and dexamethasone for 3 days, with the praziquantel treatment being repeated at 3-4 weeks. The significant differences observed in the clinical presentation of Schistosoma mansoni-induced infection, indicate that a well-differentiated therapeutic strategy is required when this infection is diagnosed in a non-immune (traveller) or a semi-immune (immigrant) patient.

Adult↗
PubMed2002

Treatment of severely psychotic inpatients with schizophrenia: olanzapine versus other antipsychotic drugs.

Nine hundred and ten schizophrenic inpatients suffering from acute psychotic episodes were included in a naturalistic study. Patients were prescribed treatment with olanzapine (OLZ) or with typical antipsychotic (TYP) drugs. Patients receiving another atypical antipsychotic were excluded. Of the whole sample, 483 (53.4%) were treated with olanzapine and 421 (46.6%) with typical antipsychotics. Three specific subpopulations of greater severity were defined: patients with prominent psychotic symptoms, agitated patients, and patients initially treated with intramuscular (i.m.) medication because of their acute clinical condition. Severity of illness was assessed using the Clinical Global Impression (CGI) scale for severity, the Brief Psychiatric Rating Scale (BPRS) and the Nursing Observational Scale for Inpatient Evaluation. Baseline differences were adjusted per data analysis. The mean change from baseline to endpoint of overall symptomatology (total BPRS score) was significantly greater in the olanzapine group compared to the typical antipsychotic-treated group, both in the sample of patients with prominent positive symptoms (P < 0.001) and in the sample of agitated patients (P =0.015). Significant differences were also found in BPRS positive scores, BPRS negative scores and CGI scores in these two populations. Patients who had received previous i.m. drugs showed no statistically significant differences in symptomatic improvement between both treatments groups, except for a more favourable response of BPRS negative subscores in the olanzapine group (P =0.015). The results suggest that olanzapine may be considered as a first line treatment for severely psychotic inpatients with schizophrenia.

Acute Disease↗
PubMed2001

[Sexual behavior risk in Spanish international travelers].

BACKGROUND: To know the sexual behavior of Spanish international travelers and its association with geographical destinations and sexually transmitted disease acquisition. PATIENTS AND METHOD: 1,008 consecutive patients who attended a tropical out-patient clinic during 26 months were surveyed by means of a previously designed clinical questionnaire that included specific questions regarding sexual practices during the trip. RESULTS: 19% of travelers had sexual intercourse; 53.6% of them having employed a condom. There were no differences regarding gender or destination. 3.4% of travelers who had unprotected sexual intercourse acquired HIV. CONCLUSIONS: A high proportion of travelers have unprotected, risk sexual contacts. A low but alarm

Adult↗
PubMed2001

[Cyclosporiasis: a clinical and epidemiological study in travellers with imported Cyclospora cayetanensis infection].

BACKGROUND: To assess the clinical and epidemiological characteristics of the enteritis produced by Cyclospora cayetanensis. PATIENTS AND METHOD: A microbiological, epidemiological and clinical protocol in travelers to tropical and temperate areas affected by travelers diarrhea (TD). RESULTS: C. cayetanenesis was isolated from 55 patients. 96% of them suffered TD. Persistent diarrhea (> 2 weeks) was present in 69% and weight loss > or = 3 kg in 38%. In 36% of cases, TD began after returning from the trip. Although C. cayetanensis has a cosmopolitan distribution, it was mostly isolated from travellers to Latin America, the Indian subcontinent and South East Asia. In only five cases a potential risk factor was detected: strawberries (3), buffalo's milk (1) and marinated fish "ceviche" (1). CONCLUSIONS: C. cayetanensis is an emerging enteropathogen, isolated in 2-4% of Spanish travellers suffering from TD, and should be considered in the diferential diagnosis of this clinical entity.

Cyclosporiasis↗
PubMed2001

[Neurocysticercosis: an imported disease?].

BACKGROUND: Neurocysticercosis is the CNS involvement caused by Taenia solium larvae and the most frequent cerebral parasitation. It has a cosmopolitan distribution but endemic in the low income countries. The paper analizes the geographic origin, clinical characteristics of patients and the diagnostic and therapeutic modalities. PATIENTS AND METHOD: Retrospective revision of clinical files in patients with the diagnosis of neurocysticercosis between the period January 1990 to March 2000. RESULTS: Ten patients were included of which only one was of Spanish nationality. The others were immigrants or travellers to Central/South America (7), Africa (1) and South East Asia (1). Nine patients presented with convulsive crisis, generalized in 7 and 3 cases suffered headaches. The diagnosis was obtained through biopsy technique (3 cases) and the rest through CT scan or MR and serology. ELISA specific serology was positive in 60% of cases. Eight patients were treated with praziquantel or albendazol solely with good clinical evolution. CONCLUSIONS: Neurocysticercosis is prevalent among the immigrant population and in our case imported mostly from Latin America. Diagnosis is reached through imaging and serological techniques. Treatment with praziquantel or albendazol improves the clinical picture and controls the convulsive crisis.

Emigration and Immigration↗
PubMed2001

[Katayama fever in Spanish tourists: analysis of 25 cases].

BACKGROUND: Awareness about the clinical presentation and the clinical and terapeutical management of acute schistosomiasis in the non immune traveller. PATIENTS AND METHOD: Febrile patients with epidemiological history of swimming in endemic areas. Prospective protocol 1984-1999. RESULTS: 21% of patients with a diagnosis of schistosomiasis developed the Katayamna syndrome. Nine patients had also a clinical picture of swimmer's itch dermatitis. Diagnosis was suspected on the basis of epidemiology, fever and eosinophilia. Diagnostic confirmation was established through serology in 10 cases and parasitology in 11. In 2 cases both methods were positive. CONCLUSIONS: Fever and eosinophilia after being exposed to infested waters should rise alarm on the syndrome. Availability of serological tests with an earlier positivization and badly needed at present. In Spain two trips, to Mali (Dogon country) and Uganda, are responsible for 75% of the infections. The subject should be introduced routinely in our travellers clinics.

Adult↗
PubMed2000

Enteroaggregative escherichia coli virulence factors in traveler's diarrhea strains.

Enteroaggregative Escherichia coli (EAEC) is associated with diarrhea in Spanish travelers to developing countries. In this study, the polymerase chain reaction was used to test EAEC isolates for genes encoding putative virulence factors, including EAEC adhesins, the plasmid-encoded toxin (Pet), a heat-stable enterotoxin (EAST), and Shigella enterotoxins 1 and 2 (ShET1 and ShET2). Findings included a low prevalence of genes for Pet (4.3%), ShET2 (4.3%), and the adherence factor AAF/II (8.7%). The overlapping genes encoding the ShET1 and the Pic mucinase were present in most EAEC strains tested (56.5%); however, some strains that carried this locus did not produce both proteins, as determined by Western immunoblot. Surprisingly, ShET1 and ShET2 genes were also found in other E. coli pathotypes, as was the EAST toxin locus. These findings underscore the heterogeneity of EAEC strains and suggest that the ShET1 may be an important virulence factor in traveler's diarrhea.

Adhesins, Escherichia coli↗
PubMed2000

Diarrhea in children under 5 years of age from Ifakara, Tanzania: a case-control study.

A matched case-control study was conducted in the Maternal and Child Health Clinic (MCH) in Ifakara, Tanzania, during the rainy season in order to elucidate the risk factors for and etiology of diarrheal diseases in children under 5 years of age. Cases (103) and controls (206) were matched for sex and age group. Precoded questionnaires with demographic details, clinical history, and physical signs were completed. Stools samples were collected for bacterial, parasitological, and viral studies. A high number of siblings (odds ratio [OR], 0.86; P = 0.027), the number of siblings surviving (OR, 0.82; P = 0.007), the birth order (OR, 0.85; P = 0.018) and the distance from the house to the water source (OR, 0.33; P = 0.011) were associated with the risk of diarrhea. There were high rates of enteropathogen isolates in stool samples from children without diarrhea (52.23%). Shigella species were the only enteropathogen statistically related with diarrhea (OR, 2.90; P < 0.029). Enterotoxigenic, enteropathogenic, and enteroaggregative strains of Escherichia coli were not related with diarrhea, and neither were Giardia lamblia or Salmonella species.

Case-Control Studies↗
PubMed2000

[Diagnostic usefulness of the intradermal test with histoplamin in non-endemic areas of histoplasmosis].

The histoplasmosis in Spain is an imported disease presenting in most of case diagnostic difficulties. In this paper, the intradermal skin test with Histoplasma capsulatum antigen as diagnostic method in immunocompetent patients with clinical and radiological signs compatible with histoplasmosis after being visited Central and South American endemic counties, in which this mycosis is endemic. Nine Spanish patients coming from different countries of Latin America with fever and acute respiratory symptoms compatible with histoplasmosis were studied. Other nine accompanying subjects and five controls were also evaluated. Patients underwent mycological cultures and and serological tests for H. capsulatum. Intradermal test with 1% histoplasmine were done in all patients. Serology and skin tests tests were also performed in accompanying people. Intradermal were done in healthy controls. Skin test with histoplasmine were positive in seven of the nine patients. Six of these showed precipitating antibodies against the same antigen. H. capsulatum was only isolated from bone marrow biopsy samples in one patient. The seven patients were given itraconazole by oral route and all symptoms improved after 2 and 4 weeks. In five accompanying subjects the skin test were also positive so that a subclinical histoplasmosis was diagnosed. In the remaining patients and healthy accompanying subjects histoplasmosis infection was excluded. In non endemic geographical areas of histoplasmosis intradermal skin test with histoplasmin when used in immunocompetent individuals is an easy and reliable method for the diagnosis of this mycosis as well as for epidemiological studies.

English Abstract↗