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Biomedical subjects

P Cabrera

Publications and source records attributed to P Cabrera.

At least 19 recordsLinked to original sources
PubMed2005

The effect of treatment with omalizumab, an anti-IgE antibody, on asthma exacerbations and emergency medical visits in patients with severe persistent asthma.

BACKGROUND: Patients with severe persistent asthma who are inadequately controlled despite treatment according to current asthma management guidelines have a significant unmet medical need. Such patients are at high risk of serious exacerbations and asthma-related mortality. METHODS: Here, we pooled data from seven studies to determine the effect of omalizumab, an anti-immunoglobulin E (IgE) monoclonal antibody, on asthma exacerbations in patients with severe persistent asthma. Omalizumab was added to current asthma therapy and compared with placebo (in five double-blind studies) or with current asthma therapy alone (in two open-label studies). The studies included 4308 patients (2511 treated with omalizumab), 93% of whom had severe persistent asthma according to the Global Initiative for Asthma (GINA) 2002 classification. Using the Poisson regression model, results were calculated as the ratio of treatment effect (omalizumab : control) on the standardized exacerbation rate per year. RESULTS: Omalizumab significantly reduced the rate of asthma exacerbations by 38% (P < 0.0001 vs control) and the rate of total emergency visits by 47% (P < 0.0001 vs control). Analysis of demographic subgroups showed that the efficacy of omalizumab on asthma exacerbations was unaffected by patient age, gender, baseline serum IgE (split by median) or by 2- or 4-weekly dosing schedule, although benefit in absolute terms appeared to be greatest in patients with more severe asthma, defined by a lower value of percentage predicted forced expiratory volume in 1 s (FEV(1)) at baseline. CONCLUSIONS: These results suggest that omalizumab may fulfil an important need in patients with severe persistent asthma, many of whom are not adequately controlled on current therapy.

Anti-Asthmatic Agents↗
PubMed2005

A 6-month regimen for EPTB with intermittent treatment in the continuation phase: a study of 679 cases.

BACKGROUND: No large studies have demonstrated the effectiveness of a 6-month regimen for all forms of extra-pulmonary tuberculosis (EPTB). METHODS: Retrospective, observational analysis to evaluate the effectiveness of a 6-month treatment regimen (2HRZE/4H3R3) for all patients diagnosed with EPTB in Caracas, Venezuela, from 1 January 1998 to 31 December 2000, using direct observation. RESULTS: Of 679 patients enrolled, 101 (14.9%) had AIDS. In 83.2% the diagnosis was based on microbiological, histological or genetic amplification information. Of 612 (90.1%) patients who took more than 90% of the doses, treatment had to be altered in six (1%) due to drug side effects. Of the remaining 606 patients who took more than 90% of the doses, 603 (99.5%) were cured and three failed. In the follow-up conducted 2 years after the end of treatment, only 6 relapsed (1%). Cures without relapse were achieved in 24 cases of central nervous system involvement, 27 cases of osteoarticular involvement and in the 42 who had miliary and/or disseminated TB. CONCLUSION: A 6-month treatment regimen for all forms of EPTB, with treatment three times a week during the continuation phase, was highly effective.

Adolescent↗
PubMed2003

Epidemiology of tuberculosis on Gran Canaria: a 4 year population study using traditional and molecular approaches.

BACKGROUND: In recent years several population based studies using restriction fragment length polymorphism (RFLP) analysis have shown a higher rate of recent transmission of tuberculosis than previously thought. This study was undertaken to determine the transmission patterns of tuberculosis and the potential causes of recent transmission on the island of Gran Canaria (Spain). METHODS: The strains of all patients diagnosed with tuberculosis confirmed by culture between 1 January 1993 and 31 December 1996 were typed by RFLP using the insertion sequence IS6110. A cluster was defined as two or more isolates with an identical RFLP pattern. Epidemiological linkage through contact tracing was investigated. RESULTS: Of the total of 719 patients, 153 (21.3%) were excluded because there was inadequate bacterial DNA for genotyping (n=129) or the isolates of Mycobacterium tuberculosis had less than five copies of IS6110 (n=24). The isolates from 409 patients (72.3%) were grouped into 78 different clusters with an estimated 58.5% of the cases being due to recent transmission. Young age was the only significant predictor of clustering. Only in 147 (35.9%) of the 409 patients belonging to a cluster could an epidemiological link be found. 111 patients (19.6%) were identified as having had previous contact with a tuberculosis patient and 81 of them (72.9%) belonged to a cluster. The three largest clusters included 75, 49 and 20 patients, respectively. CONCLUSION: Recent transmission is frequent among patients with tuberculosis on Gran Canaria and could be associated with certain aspects of control measures. Some of the clusters described in the study could be due to the prevalence of particular strains of M tuberculosis on the island.

Adult↗
PubMed2001

Epidemiological evidence of the spread of a Mycobacterium tuberculosis strain of the Beijing genotype on Gran Canaria Island.

Molecular epidemiological studies suggest that particular Mycobacterium tuberculosis strains have an enhanced capacity to spread within a community. One strain, the Beijing genotype, has been associated with outbreaks in a number of communities throughout the world. IS6110 restriction fragment length polymorphism (RFLP) analysis was performed on M. tuberculosis isolates from 566 of the 721 patients (78.5%) diagnosed with tuberculosis (TB) on Gran Canaria Island from 1993 to 1996, as well as 35% of isolates from 1991-1992 (85 strains). RFLP identification of the family of strains of the Beijing genotype was confirmed by spoligotyping. Medical records of all patients were reviewed and epidemiological links were identified. Of 566 M. tuberculosis isolates from 1993 to 1996 with RFLP available, 72% belonged to clusters. The largest contained 75 cases and was caused by a strain of the Beijing genotype that was introduced to the island in 1993. It was found in 10 patients in 1993 (5.5%), 12 in 1994 (8.1%), 18 in 1995 (16.4%), and 35 in 1996 (27.1%). Epidemiological linkage was confirmed for 68% of cases. This study has demonstrated rapid dissemination of this strain of the Beijing genotype. This genotype might play an important role in the future of the worldwide tuberculosis epidemic.

Adolescent↗
PubMed2001

Ovine Echinococcus granulosus transmission dynamics in the province of Rio Negro, Argentina, 1980-1999.

In this work, the impact of a hydatidosis control programme for dogs on the intermediate ovine host was specifically analysed to determine the levels of prevalence achieved and the dynamics of parasite transmission, as well as to evaluate the quality of diagnostic systems in slaughterhouses. A field study was conducted in four slaughterhouses (Valcheta, Los Menucos, Jacobacci, Bariloche) that process animals coming from all the departments within the work area. The control programme for dogs entailed treating dogs with 5 mg/kg praziquantel at 2-month intervals for 20 years. Sample size was determined with a 10% error margin and a 95% significance level. Harvested viscera (liver, lungs, kidneys) were preserved in 5% formaldehyde and sent to the laboratory for diagnostic confirmation of both positive and negative specimens. The 61% initial prevalence dropped to 18.3% at the end of the 10-year period, observed differences proving significant (Chi-square=15.454, P=0.00). There were statistically significant increases in infection prevalence with age (Pearson's Chi-square=133.61, P=0.00). Overall, 37.2% of hydatidosis cases diagnosed in slaughterhouses were considered non-hydatid by histological study. On the other hand, 1.1% of those diagnosed as healthy were found to be infected with hydatidosis. The number of hydatid cysts per animal increased with age: 0.04 in lambs and 1.22 in adults (linear regression equation, -0.0539+0.0127 x age), whereas the average for the whole period was 3.7% in lambs and 20.5% in adults. Viability studies indicated that 63.8% of parasitised animals had viable cysts, out of which 53.3% were fertile. Diagnosis of infection in sheep made by means of an adjusted statistical design and with histological confirmation of the presumptive diagnosis made in slaughterhouses demonstrated the flaws of the official systems for epidemic surveillance of hydatidosis. However, there was no overall significant difference in slaughterhouse and laboratory data.Ro was 0.53 and could imply a decrease in reproductive capacity of the parasite and steady state extinction.

Abattoirs↗
PubMed2001

Exogenous reinfection with tuberculosis on a European island with a moderate incidence of disease.

The frequency and determinants of exogenous reinfection and of endogenous reactivation of tuberculosis in patients previously treated are poorly understood. In Gran Canaria Island, Spain, between 1991 and 1996, 962 tuberculosis cases were confirmed by culture. Drug susceptibility testing was performed on available bacterial isolates and IS6110-based RFLP genotyping was carried out. Twenty-three patients (2.4%) had two positive cultures separated by at least 12 mo, 18 of whom had bacterial DNA available for genotypic analysis. The initial and final isolates from eight (44%) were different genotypes, indicating exogenous reinfection. Six of them were retreated after cure and two retreated after default. Six were HIV seronegative and two were HIV seropositive. Endogenous reactivation was seen in the remaining 10 patients of whom eight were retreated after default and two after cure. Three of the eight (38%) being retreated after default developed multidrug resistance. One genotype was responsible for a second episode of tuberculosis in five cases, three exogenous reinfections and two endogenous reactivations. In the context of a moderate incidence of tuberculosis, exogenous reinfection is an important cause of TB recurrence, even in HIV-seronegative patients.

Adult↗
PubMed2001

Ixodes (Haemixodes) longiscutatum Boero (new status) and I. (H.) uruguayensis Kohls & Clifford, a new synonym of I. (H.) longiscutatum (Acari: Ixodidae).

Females of Ixodes (Haemixodes) uruguayensis Kohls & Clifford, 1967, a species whose adults were unknown until the present, were obtained in the laboratory from engorged nymphs collected on rodents (Scapteromys tumidus and Oxymycterus nasutus) in the counties of Maldonado and San José, Uruguay. Morphological characters of these females were identical to those given in the description of the female of Ixodes longiscutatum Boero, 1944. I. uruguayensis is, thus, relegated to a junior subjective synonym of I. longiscutatum. However, because of the unique morphological characters of the immature stages, the validity of the subgenus Haemixodes Kohls & Clifford, 1967 is not questioned. Therefore, the new status of Ixodes (Haemixodes) uruguayensis Kohls & Clifford, 1967 is Ixodes (Haemixodes) longiscutatum Boero, 1944.

Animals↗
PubMed2001

Expression of CD44 splice variants in spontaneous murine tumors.

CD44 is a widely distributed set of cell surface glycoproteins expressed in several types of cells and tissues, implicated in cell-cell and cell-substrate interactions. This molecule plays a major role in cell differentiation, development and activation and has also been described as a potential marker of malignancy and metastasis. In the present study we investigated by RT-PCR followed by exon specific amplification the expression of CD44 splice variants in four different murine tumors as well as in the invaded organs in order to correlate the expression of CD44 variants with potential tumor invasiveness and their implications for growth. Our data showed deregulation in the expression of CD44 isoforms but no discernible correlation in isoform expression pattern. However, in all tumors studied isoforms presented by the primary tumor were detected in the invaded organs before metastasis could be demonstrated by histopathological analysis.

Alternative Splicing↗
PubMed1998

Human cystic echinococcosis in a Uruguayan community: a sonographic, serologic, and epidemiologic study.

A prevalence and transmission study of human cystic echinococcosis (CE), due to infection with the dog tapeworm Echinococcus granulosus, was undertaken in the village of La Paloma in central Uruguay. The human population was registered and screened for CE by abdominal ultrasound scan as well as a number of serologic tests. Dogs were screened for E. granulosus infection by arecoline purgation as well as specific coproantigen testing. The total prevalence of human CE (new cases and those with a previous history) was 5.6% (64 of 1,149); 3.6% (40) of the cases were new ultrasound detected asymptomatic cases (mean age = 45 years). Age prevalence increased from 1.1% in the 4-6-year-old group to > 11% in the > 60-year-old group; the 20-29-year-old group had a significantly higher CE rate of 7.4%, compared with younger and older age groups, and there was no difference between sexes. A CE rate of 3.9% (20 of 514) was also recorded by ultrasound for new cases in the population residing outside the village. Most of the hydatid cysts were located in the liver presenting as either univesicular cysts or a solid mass, and of those 71% and 63%, respectively, with such cyst presentations were seropositive against E. granulosus cyst fluid antigens. Two of eight individuals who were filter paper blood spot seropositive, but ultrasound scan negative, were subsequently diagnosed respectively with pulmonary hydatidosis after radiography, and hepatic hydatidosis after computed tomography scan. Of 36 households with a CE patient, 32 were single cases while four households each harbored two CE cases. This did not represent a clustered distribution within families (23 of 117). Almost 20% of the dogs from La Paloma were found infected with E. granulosus after purge examination, with a mean worm number of 67 (range = 1-1,020). An additional eight dogs that were purge negative were Echinococcus coproantigen positive. The study showed that human CE is highly endemic in Uruguay, with one of the highest local prevalence rates in the world. Transmission appears to occur readily within well-developed towns, as well as on rural sheep ranches. Mass screening by ultrasound scanning with confirmatory serologic testing is an effective approach to case detection at the community level.

Adolescent↗
PubMed1996

Effect of immediate and delayed post preparation on apical dye leakage using two different sealers.

Eighty freshly extracted teeth were endodontically prepared and filled with gutta-percha and either a zinc oxide-eugenol-based sealer or AH26 to determine what effect these sealers, with widely differing properties, would have on apical microleakage after either immediate or delayed dowel space preparation. The teeth were randomly assigned to 1 of 4 groups, and the post space was made either immediately after filling or after being stored in 100% humidity for 1 wk. They were then immersed in a 2% methylene blue solution under vacuum, washed, and split longitudinally. The extent of dye penetration was read by five independent observers and the results analyzed. The only significant difference was in the delayed preparation group with zinc oxide-eugenol sealer, which showed greater leakage than the other groups.

Analysis of Variance↗
PubMed1996

Evaluation of a directly observed six months fully intermittent treatment regimen for tuberculosis in patients suspected of poor compliance.

BACKGROUND: Although a priority for tuberculosis control is to achieve the maximum cure rate, compliance with chemotherapy in specific high risk groups (homeless, intravenous drug abusers, chronic alcoholics) is usually poor. METHODS: From January 1990 to December 1994 102 patients with tuberculosis (96 pulmonary, six extrapulmonary) who were poorly compliant with treatment were treated with a six month fully intermittent (twice weekly) directly observed regimen. They comprised 71 homeless subjects, 50 chronic alcoholics, 23 intravenous drug abusers, nine infected with HIV, and 11 who had previously abandoned a daily antituberculosis regimen; 53 had more than one of these risk factors. Treatment included isoniazid and rifampicin for six months and pyrazinamide during the first two months. Patients who failed to take their medication on two consecutive occasions were actively sought by telephone or by personal search. RESULTS: After two months of treatment 95 of the 102 patients had taken their medication regularly and 90 of them had negative cultures. Four of the remaining patients had negative cultures after three months. At the end of the six months 87 patients had completed treatment and were considered cured. Only 15 patients abandoned the treatment (13 of whom had more than one risk factor). Only three relapses occurred in the 102 patients at one year follow up and in the 88 patients followed for two years. Two patients required a change of treatment due to major side effects. Although intravenous drug abuse was the only predictor of non-compliance in the multivariate analysis, if the available variables in the second month of treatment were analysed, current poor compliance and abandonment of treatment in the past were found to be significantly associated with non-compliance. CONCLUSIONS: This study shows the efficacy of this intermittent regimen and the effectiveness of a directly observed treatment programme.

Adolescent↗
PubMed1996

Massive hemoptysis as a manifestation of fistulized thoracic aortic aneurysms into the bronchial tree.

Aortobronchial fistulas are an uncommon and serious cause of hemoptysis. We present three cases of aortobronchial fistulas that were diagnosed and treated at our hospital. They were presented as massive hemoptysis. The clinical suspicion of a leaking thoracic aortic aneurysm into the bronchial tree should prompt the correct diagnostic procedures since early surgery is the only way to manage this condition.

Aged↗
PubMed1995

Echinococcus granulosus infections of dogs in the Durazno region of Uruguay.

The prevalence and distribution of Echinococcus granulosus in domestic dogs was examined in three dog populations in the Durazno region of Uruguay. The prevalence was 19.7 per cent in 704 dogs successfully purged with arecoline hydrobromide. Higher prevalences were detected in dogs from the rural area (30.0 per cent) and the village of La Paloma (25.9 per cent) than in the town of Sarandi del Yi (7.9 per cent). The frequency distribution of E granulosus was overdispersed (k, the negative binomial parameter = 0.08), with only a few animals harbouring heavy infections. The results of a questionnaire showed that the prevalence was greatest in male dogs, in dogs that were not kennelled, in dogs that had access to fields and in dogs that were not dosed with praziquantel. Dogs that were given raw sheep offal by their owners were no more likely to be parasitised than other dogs; this may reflect the inaccuracy of the owners' replies, or that the dogs were being infected outside their home.

Animals↗
PubMed1995

Diagnosis of canine echinococcosis: comparison of coproantigen and serum antibody tests with arecoline purgation in Uruguay.

Echinococcus granulosus is one of the most important and widespread of the helminth zoonoses. Diagnosis of E. granulosus infection in dogs currently relies on arecoline dosing and detailed examination of the purge for adult worms. Two immunodiagnostic tests (ELISA) based on genus specific coproantigen detection or serum antibody (IgG, IgA and IgE) detection were compared against arecoline purgation for the detection of Echinococcus in naturally infected dogs in Uruguay. The coproantigen ELISA had a sensitivity of 76.9% compared with 34.6% for the serum IgG ELISA when assessed against 26 purge positive dogs (purge worm count range 1-4331). Coproantigen reactivity was positively correlated (r = 0.65) to purge worm count, with a threshold at over 20 worms. There was no positive correlation of antibody levels with worm counts. In 26 matched Echinococcus positive dog samples, the overall sensitivity of serological detection increased to 69.2% when seroreactivity for IgA and IgE antibodies were included and to 96.2% for both coproantigen and antibody assays combined. The detection of current infection of individual dogs with E. granulosus by coproantigen ELISA has the potential to replace arecoline purgation, while specific serum antibody detection should be useful in assessing Echinococcus exposure in dog populations.

Animals↗
PubMed1995

The epidemiology of tuberculosis in Gran Canaria, Canary Islands, 1988-92: effectiveness of control measures.

SETTING: Since there is no national programme for tuberculosis control in Spain and the epidemiological situation in this country is unknown, a programme against tuberculosis in Gran Canaria (Canary Islands) was started in 1987. OBJECTIVE: To analyze the impact of this control programme, particularly the trend of new cases of tuberculosis by age groups and risk factors for 1988-92. DESIGN: A detailed search of all new cases of tuberculosis was carried out by examining the files of all public and private hospitals and outpatient clinics of the island, the records of the Services of Clinical Microbiology and Pathology of the public hospitals, and the registers of patients with AIDS. RESULTS: The annual rates of new cases of tuberculosis per 100,000 were 32.2 in 1988 (214 cases), 26.2 in 1990 (174 cases), and 29.4 in 1992 (196 cases), and the rates of sputum-positive cases 13.3 (89 cases), 12 (80 cases) and 15 (100 cases), respectively. The distribution of tuberculosis cases by age peaked in the age groups 40-49 and 30-39 years. Between 1988 and 1992, statistically significant differences were found in the percentage of cured patients (21% [45/214] vs 85.7% [168/196]), patients with a delay in diagnosis > 3 months (40.2% [86/214] vs 21.9% [43/196]), and contacts evaluated (45.3% [97/214] vs 90.3% [177/196]). However, an upward trend in the incidence of tuberculosis for 1990-92 was found in association with an increase of new cases among the homeless, immigrants, and HIV-infected people. When these three population groups were excluded from the analysis, the annual rate for the total population showed a progressive decline from 1988-92. CONCLUSIONS: The data studied here show that successful priority control measures (cure rate, early diagnosis, study of contacts) have been achieved in this island. It is necessary, however, to develop strategies for combating the tuberculosis problem in specific high risk populations.

Adolescent↗
PubMed1995

Transbronchial fine needle aspiration in clinical practice.

We review our experience of transbronchial fine needle aspiration (TBFNA) over a 3-year period. A total of 112 TBFNAs were performed on 95 patients. Four aspirates were from peripheral lung lesions, 20 from non-ulcerated submucosal infiltrative lesions, 19 from mediastinal abnormalities close to the tracheobronchial tree, and the remaining 69 were for staging of bronchogenic carcinoma with apparent mediastinal lymph node spread, evaluated by chest computed tomography (CT). In the 20 submucosal lesions TBFNA reached a sensitivity of 82.3%, providing the only evidence of a malignant process in five cases. With respect to the 19 mediastinal lesions arising in close proximity to the central airways, TBFNA permitted a diagnosis in cases that would otherwise have required more invasive procedures, although the diagnostic sensitivity of the technique in this group of patients was poor (26%). In the mediastinal staging group, the sensitivity was 76.9%, with no false positive results. Complete sensitivity of TBFNA for the detection of disease was 65.8%. We conclude that TBFNA is a reliable and low risk procedure.

Adolescent↗
PubMed1995

DNA analysis of bronchoalveolar lavage in the diagnosis of pulmonary lymphoma.

Lung lymphomas frequently present a diagnostic challenge. The diagnosis of malignant lymphoma is possible when lymphocyte subpopulations show aneuploidy or a definable monoclonal surface marker or both. We present a case of lymphoma of the lung in which DNA analysis of bronchoalveolar lavage fluid was the first successful method in the time course of diagnosis.

Aged↗