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Biomedical subjects

E Martinez

Publications and source records attributed to E Martinez.

At least 37 records · Page 2Linked to original sources

Domiciliation process of Rhodnius stali (Hemiptera: Reduviidae) in Alto Beni, La Paz, Bolivia.

We report a systematic collection of Triatominae inside houses and in the peridomestic environment of Alto Beni, department of La Paz, Bolivia. This area is free of Triatoma infestans and although we detected previously seropositivity for Trypanosoma cruzi, the Alto Beni region is not officially considered as endemic for Chagas disease. From 11 houses of five localities, we collected adults, nymphs and eggs of a Rhodnius species, which was confirmed by morphological and morphometric analysis as Rhodnius stali. This little-known species has long been confused with R. pictipes, and was originally described from museum specimens labelled as R. pictipes. Our data show that R. stali is able to establish colonies in domestic and peridomestic habitats in Bolivia, and it is probably the vector responsible for Chagas disease seropositivity observed in the indigenous population of Alto Beni.

Animals↗

[Myospherulosis of the maxillary sinus].

BACKGROUND: We present a case of a myospherulosis, describe the underlying cause and discuss ways of preventing its development. CASE REPORT: A 35-year-old man presented myospherulosis of the maxillary sinus caused by an antibiotic ointment placed in the sinus three years earlier during a Caldwell Luc procedure. The patient underwent a second Calwell Luc procedure. Outcome was uneventful and no recurrence was noted. DISCUSSION: Histological examination should be ordered at reoperation and petroleum-based ointments and packings should be avoided in sinus surgery.

Adult↗

Streptococcus agalactiae infective endocarditis: analysis of 30 cases and review of the literature, 1962-1998.

We describe 30 cases (1.7%) of community-acquired penicillin-susceptible Streptococcus agalactiae endocarditis among 1771 episodes of endocarditis diagnosed in 4 Spanish hospitals from 1975 through 1998. Endocarditis affected a native valve (most often the mitral valve) in 25 cases (83%). Surgical valve replacement was performed for 12 patients (40%). Fourteen patients (47%) died. Mortality rates for patients with native and prosthetic valve endocarditis were 36% and 100%, respectively (P=.01). The mortality rate for native valve endocarditis decreased during the last 6 years of the study (from 61% in 1975-1992 to 8% in 1993-1998; P<.05). Additionally, 115 cases in the literature from 1962-1998 were reviewed. During 1980-1998, the percentage of patients who underwent cardiac surgery increased from 24% (in the previous period, 1962-1979) to 43% (P=.05) and the mortality rate decreased from 45% to 34% (P=NS). S. agalactiae is an uncommon cause of endocarditis with a high mortality rate, although the prognosis of native valve endocarditis has improved in recent years, probably because of an increased use of cardiac surgery.

Adult↗

Phase I study of weekly CPT-11 (irinotecan)/docetaxel in patients with advanced solid tumors.

Based on the synergistic cytotoxicity demonstrated in vitro by topoisomerase I inhibitors followed by docetaxel and the feasibility of giving both drugs on a weekly schedule avoiding overlapping toxicities, we designed a phase I trial of weekly CPT-11 (irinotecan)/docetaxel to determine the dose-limiting toxicities (DLT) and the maximum-tolerated dose (MTD) of this combination. Eighteen patients with advanced solid tumors treated with at least one prior chemotherapy regimen were included in this trial. CPT-11 was administered as a 90-min (intravenous) IV infusion followed immediately by docetaxel as a 30-min IV infusion. Both drugs were given on days 1, 8 and 15 in 4-week cycles. Four escalating dose levels of CPT-11/docetaxel (level I: 60/20 mg/m(2), level II: 60/25 mg/m(2), level III: 70/25 mg/m(2), and level IV: 70/30 mg/m(2)) were studied. Forty-seven cycles were administered (range, 1-5 courses) with a median number of 2.6 cycles per patient. Grade 4 leukopenia was the DLT reached at dose-level IV (CPT-11/docetaxel 70/30 mg/m(2)). Four patients had grade 3 anemia at dose levels III (two patients) and IV (two patients), while grade 3/4 thrombocytopenia was not seen. Grade 3/4 non-hematologic toxicities included grade 3 diarrhea in two patients (dose levels II and IV), grade 3 asthenia in one patient (dose level II) and grade 3 stomatitis in one patient (dose level I). The recommended dose of this weekly schedule is CPT-11 70 mg/m(2) and docetaxel 25 mg/m(2). DLT of this regimen is leukopenia, although toxicity is manageable at the recommended dose level. The activity of this regimen is being evaluated in a phase II study in previously treated patients with advanced non-small cell lung cancer.

Adult↗

Strategically designed sample composition for fastest screening of polychlorinated biphenyl congeners in water samples.

A new strategy for preparing composite samples of special interest and applicability in environmental screening studies is presented. The use of supersaturated experimental design matrices to conduct the sample composition of water sample specimens in screening studies is demonstrated. In contrast to well known conventional sample composition, this strategic approach provides analytical objects allowing the accurate prediction of analyte concentration levels in the original individual sample specimens while fixing the number of experiments to be carried out down to the very number of sample specimens. This will be of special importance when dealing with analytes that require complicated, labour intensive and expensive analytical processes. To reach this goal, two main conditions must be fulfilled. The first one is the sparsity effect (Pareto principle) which holds for the specimens in the sampling campaign. This means that the number of really anomalous or contaminated specimens, as compared to the total number of specimens to be analysed, is low. In environmental screening studies, frequently this situation can be reasonably assumed. The second condition is to have an effective manner to develop and solve the experimental designs required to build-up the composite samples. The challenging problem of screening PCBs in water samples has been tackled to show the usefulness of this strategic approach by combining chemometrically assisted sample composition and rapid analysis using solid-phase microextraction of the composite samples.

Environmental Monitoring↗

Interferon-alpha and ribavirin for the treatment of recurrent hepatitis C after liver transplantation.

BACKGROUND: Initial studies utilizing interferon-alpha and ribavirin for the treatment of recurrent hepatitis C virus (HCV) infection after liver transplantation showed promising results. Here we report our single-center experience using this combination therapy. METHODS: Liver transplant recipients with recurrent HCV (elevated serum aminotransferases, positive serum HCV RNA, and biopsy-proven hepatitis without rejection) received interferon-alpha (1.5-3 million units subcutaneously three times a week) and ribavirin (400-1000 mg p.o. daily) for 12 months or more. Serum aminotransferases, HCV RNA, and severity of hepatitis were followed. RESULTS: Thirty-two patients have been treated for at least 3 months, including 13 who have been on 12 or more months of therapy. Three died from allograft failure due to recurrent HCV. Dose reductions of interferon-alpha and/or ribavirin occurred in 22 patients. Thirteen had their medications permanently discontinued for severe adverse effects. Twenty-six patients (81%) had a biochemical response (BR; normalization of serum aminotransferases) after 3 months. End-of-treatment and sustained BR were 77% and 71%, respectively. Mean viral loads decreased 68-77%; however, only three patients became serum HCV RNA negative. After 12 months of therapy, no histological improvement was observed in 11 patients who were biopsied. Patients who received mycophenolate mofetil or daclizumab had a less likelihood of achieving a BR. CONCLUSIONS: A significant number of patients did not tolerate interferon-alpha or ribavirin. Although BR was excellent and mean viral loads decreased significantly, virological clearance was poor and no histological improvement was noted. A more efficacious treatment with less adverse effects for recurrent HCV after liver transplantation is needed.

Adult↗

Risk of lipodystrophy in HIV-1-infected patients treated with protease inhibitors: a prospective cohort study.

BACKGROUND: Risk factors for lipodystrophy in patients infected with HIV-1 treated with highly active antiretroviral therapy (HAART) containing HIV-1 protease inhibitors are poorly understood. We aimed to identify the risk factors for lipodystrophy in antiretroviral-naive HIV-1-infected adults on HAART. METHODS: Moderate or severe body-fat changes were clinically assessed and categorised as subcutaneous lipoatrophy, central obesity, or both, in all consecutive antiretroviral-naïve HIV-1-infected adults who began HAART with two nucleoside reverse transcriptase inhibitors plus at least one protease inhibitor from October, 1996, to September, 1999. A person-years analysis was used to calculate the incidence of types of lipodystrophy, and Cox proportional hazards models were used to describe the univariate and multivariate factors associated with progression to any lipodystrophy. FINDINGS: After a median follow-up of 18 months, 85 (17%) of the 494 patients developed some type of lipodystrophy. The incidences of any lipodystrophy, lipodystrophy with subcutaneous lipoatrophy, and lipodystrophy with central obesity were 11.7 (95% CI 9.2-14.2), 9.2 (7.0-11.4), and 7.7 (5.7-9.7) per 100 patient-years. An increased risk for any lipodystrophy was found among women as compared with men (relative hazard 1.87 [1.07-3.28]), heterosexuals (2.86 [1.50-5.48]), and homosexuals (2.17 [1.07-4.42]) as compared with intravenous drug users, with increasing age (1.33 per 10 years older [1.08-1.62]), and with the duration of exposure to antiretroviral therapy (1.57 per 6 months extra [1.30-1.88]) but not with any individual antiretroviral agent. The factors associated with an increased risk for lipodystrophy with subcutaneous lipoatrophy or lipodystrophy with central obesity were very similar to those associated with any lipodystrophy. The duration of indinavir use may represent an additional contribution for the development of lipodystrophy with central obesity (1.26 per 6 months extra [0.99-1.60]); p=0.064). INTERPRETATION: Risk factors associated with development of any lipodystrophy, lipodystrophy with subcutaneous lipoatrophy, and tipodystrophy with central obesity in patients infected with HIV-1 who were receiving HAART containing protease inhibitors are multifactorial and overlapping, and cannot be exclusively ascribed to the duration of exposure to an particular antiretroviral agent.

Adult↗

Neural processing to visual stimuli in a three-choice reaction-time task.

Some authors have suggested that certain components of the event-related potentials (ERPs) reflect underlying stages in the discrimination process. Previous studies have shown that in an auditive three-choice reaction-time task the discrimination is accomplished as a two-stage process, with the more frequently occurring stimulus discriminated at an earlier point than the rarer stimulus and the subjects could be classified as fast and slow responders in function of their response to the most frequent of the three tones. We continuously recorded the electrocerebral activity (EEG) from the scalp and the electromyographic activity (EMG) from the responding muscles in a visual three-choice reaction-time task in 10 strictly right-handed subjects. EEG and EMG responses were subsequently analyzed off-line by aligning them by the onset of either the stimulus (stimulus-synchronized) or the response (response-synchronized). The results suggest that processes of visual stimuli evaluation and response execution are continuously integrated. The discrimination and response systems to visual stimuli is accomplished as a three-stage process, one to frequent tone, another for rare 1, and the last for rare 2. The subjects were classified as fast and slow responders in function of their response to the most frequent of the three tones.

Adult↗