Browsing by Author "Pereira, SA"
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- Differences in Nevirapine Biotransformation as a Factor for its Sex-Dependent Dimorphic Profile of Adverse Drug ReactionsPublication . Marinho, AT; Rodrigues, PM; Caixas, U; Antunes, A; Branco, T; Harjivan, S; Marques, MM; Monteiro, EC; Pereira, SAOBJECTIVES: Nevirapine is widely used for the treatment of HIV-1 infection; however, its chronic use has been associated with severe liver and skin toxicity. Women are at increased risk for these toxic events, but the reasons for the sex-related differences are unclear. Disparities in the biotransformation of nevirapine and the generation of toxic metabolites between men and women might be the underlying cause. The present work aimed to explore sex differences in nevirapine biotransformation as a potential factor in nevirapine-induced toxicity. METHODS: All included subjects were adults who had been receiving 400 mg of nevirapine once daily for at least 1 month. Blood samples were collected and the levels of nevirapine and its phase I metabolites were quantified by HPLC. Anthropometric and clinical data, and nevirapine metabolite profiles, were assessed for sex-related differences. RESULTS: A total of 52 patients were included (63% were men). Body weight was lower in women (P = 0.028) and female sex was associated with higher alkaline phosphatase (P = 0.036) and lactate dehydrogenase (P = 0.037) levels. The plasma concentrations of nevirapine (P = 0.030) and the metabolite 3-hydroxy-nevirapine (P = 0.035), as well as the proportions of the metabolites 12-hydroxy-nevirapine (P = 0.037) and 3-hydroxy-nevirapine (P = 0.001), were higher in women, when adjusted for body weight. CONCLUSIONS: There was a sex-dependent variation in nevirapine biotransformation, particularly in the generation of the 12-hydroxy-nevirapine and 3-hydroxy-nevirapine metabolites. These data are consistent with the sex-dependent formation of toxic reactive metabolites, which may contribute to the sex-dependent dimorphic profile of nevirapine toxicity.
- Efavirenz Concentrations in HIV-Infected Patients With and Without Viral HepatitisPublication . Pereira, SA; Caixas, U; Branco, T; Germano, I; Lampreia, F; Papoila, AL; Monteiro, EAIMS: Data on efavirenz in HIV/viral hepatitis co-infected patients is non-consensual, probably due to liver function heterogeneity in the patients included. METHODS: A case control study was performed on 27 HIV-infected patients, with controlled and homogenous markers of hepatic function, either mono-infected or co-infected with HBV/HCV, to ascertain the influence of viral hepatitis on efavirenz concentrations over a 2-year follow-up period. RESULTS: No differences were found in efavirenz concentrations between groups both during and at the end of the follow-up period: control (2.43 +/- 1.91 mg l(-1)) vs. co-infected individuals (2.37 +/- 0.37 mg l(-1)). CONCLUSION: It was concluded that HBV/HCV infections in themselves do not predispose to an overexposure to efavirenz.
- Effect of Efavirenz on High-Density Lipoprotein Antioxidant Properties in HIV-Infected PatientsPublication . Pereira, SA; Batuca, JR; Caixas, U; Branco, T; Delgado-Alves, J; Germano, I; Lampreia, F; Monteiro, ECWHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: * In previous work, we showed a long-term and concentration-dependent beneficial effect of the non-nucleoside reverse transcriptase inhibitor efavirenz (EFV) on high-density lipoproteins (HDL) in human immunodeficiency virus (HIV)-infected patients. * Furthermore, it has been suggested that instead of the current practice of only measuring HDL-chelesterol values, the evaluation of HDL function, namely its antioxidant properties, might be an improved tool for identifying subjects at increased risk for cardiovascular events. * Paraoxonase-1 (PON-1) is an enzyme associated with HDL that is responsible for HDL antioxidant function. WHAT THIS STUDY ADDS: * In the present work, we studied the effect of EFV on the activity of PON-1 and showed, for the first time, that EFV-based antiretroviral therapy is associated with a better antioxidant function, i.e. with a higher PON-1 activity. AIMS: A long-term and concentration-dependent beneficial effect of efavirenz (EFV) on cholesterol associated with high-density lipoprotein (HDL-c) in human immunodeficiency virus (HIV)-infected patients has been documented. Furthermore, it has been suggested that, instead of the current practice of only measuring HDL-c values, the evaluation of HDL quality might be an improved tool for identifying subjects at increased risk of cardiovascular events. Paraoxonase-1 (PON-1) is an enzyme associated with HDL that is involved in the onset of cardiovascular disease and responsible for HDL antioxidant function. The aim of the present study was to investigate the effect of EFV on the circulating activity of PON-1 in HIV-infected patients. METHODS: The patients included were adults with a documented HIV-1 infection, nontreated or treated with antiretroviral regimens including EFV 600 mg once daily as first therapeutic regimen for at least 3 months. The influence of treatment with EFV, HDL-c and CD4 cell count on PON-1 activity was analysed. RESULTS: HIV-infected White patients treated with EFV had higher PON-1 activity [77.35 U l(-1) (65.66, 89.04)] (P < 0.05) and higher PON-1 activity : HDL-c ratio [1.88 (1.49, 2.28)] (P < 0.01) than untreated patients. PON-1 activity was higher in Black patients (P < 0.001) and in patients with a CD4 cell count >500 cells ml(-1) (P= 0.0120). CONCLUSIONS: EFV-based antiretroviral regimens are associated with HDL particles with a better antioxidant function, i.e. with a higher PON-1 activity. The PON-1 activity of Black patients is higher than that found in Whites regardless of treatment. Ethnicity should be taken into consideration when studying drug effects on PON-1 activity.
- Health-Related Quality of Life After Pediatric Cochlear ImplantationPublication . Pereira, SA; Sousa, H; Barros, EObjectives: To examine the results of health-related quality of life (HRQoL) questionnaire scores from deaf children fitted with at least one cochlear implant (CI) and compare responses to normal-hearing age-peers (NHP) and to their parents. Methods: This cross-sectional study included 33 pediatric patients with a hearing experience of at least 1 year with CI and a control group of 21 NHP. The KINDLR questionnaire for measuring HRQoL (generic) in children (7-12years) and adolescents (13-17years) and a CI questionnaire (specific) were completed by CI users and their parents. Scores were transformed to a 100-point scale with 100 representing the most positive response. Results: The group of children and adolescents with CI reached a similar score in the generic HRQoL (Children:78,6; Adolescents:80,4; p = 0,35) and in the overall CI questionnaire (Children:77,6; Adolescents:75,6; p = 0,53). CI users in both age groups scored generic HRQoL similarly to their NHP (NH children:82,2, p = 0,18; NH adolescents:77,5; p = 0,07) and higher than CI users from other centers (OC) (OC children:75,4; OC adolescents:70,3). CI users scored their school domain lower than their NHP (p = 0,04). Generic and CI questionnaire scores of parents and their children correlated positively (r = 0,66, p = 0,00 and r = 0,73, p = 0,00). The total scores of HRQoL in the self-rating and parent rating correlate with none of the variables at study (gender, cause of deafness, age at implantation, years with a CI, chronological age) except with speech progression (p = 0,007). Conclusions: Children with CI experience similar quality of life as NHP. Parents are reliable reporters on the status of their child's overall quality of life.
- Long-Term and Concentration-Dependent Beneficial Effect of Efavirenz on HDL-Cholesterol in HIV-Infected PatientsPublication . Pereira, SA; Branco, T; Côrte-Real, R; Germano, I; Lampreia, F; Caixas, U; Monteiro, EAIMS: To investigate the long-term effects of efavirenz on cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein (LDL-C) and triglycerides (TG). METHODS: Thirty-four HIV-infected patients who commenced efavirenz therapy were monitored for 36 months. RESULTS: In patients with baseline HDL-C<40 mg.dL-1 an increase in HDL-C from 31+/-1 mg.dL-1 to 44+/-2 mg.dL-1 (95% confidence interval 5.9, 21.9, P<0.01) was observed and remained throughout the follow-up period. Median efavirenz plasma concentration was 1.98 mg.L-1 and a direct correlation between percentage of HDL-C variation or TC/HDL-C ratio and efavirenz plasma concentrations was found. CONCLUSIONS: There is evidence of a long-term and concentration-dependent beneficial effect of efavirenz on HDL-C in HIV-infected patients.
- Rett Syndrome With and Without Detected MECP2 Mutations: an Attempt to Redefine PhenotypesPublication . Temudo, T; Santos, M; Ramos, E; Dias, K; Vieira, JP; Moreira, A; Calado, E; Carrilho, I; Oliveira, G; Levy, A; Barbot, C; Fonseca, M; Cabral, A; Cabral, P; Monteiro, J; Borges, L; Gomes, R; Mira, G; Pereira, SA; Santos, M; Fernandes, A; Epplen, JT; Sequeiros, J; Maciel, PBackground: The diagnosis of Rett syndrome (RTT) is based on a set of clinical criteria, irrespective of mutation status. The aims of this study were (1) to define the clinical differences existing between patients with Rett syndrome with (Group I) and without a MECP2 mutation (Group II), and (2) to characterize the phenotypes associated with the more common MECP2 mutations. Patients and Methods: We analyzed 87 patients fulfilling the clinical criteria for RTT. All were observed and videotaped by the same paediatric neurologist. Seven common mutations were considered separately, and associated clinical features analysed. Results: Comparing Group I and II, we found differences concerning psychomotor development prior to onset, acquisition of propositive manipulation and language, and evolving autistic traits. Based on age at observation, we found differences in eye pointing, microcephaly, growth, number of stereotypies, rigidity, ataxia and ataxic-rigid gait, and severity score. Patients with truncating differed from those with missense mutations regarding acquisition of propositive words and independent gait, before the beginning of the disease, and microcephaly, growth, foot length, dystonia, rigidity and severity score, at the time of observation. Patients with the R168X mutation had a more severe phenotype, whereas those with R133C showed a less severe one. Patients with R294X had a hyperactive behaviour, and those with T158M seemed to be particularly ataxic and rigid. Conclusion: A clear regressive period (with loss of prehension and language, deceleration of growth) and the presence of more than three different stereotypies, rigidity and ataxic-rigid gait seemed to be very helpful in differentiating Group I from Group II.