Estudo dosimétrico para implementação da técnica radioterapêutica volumetric modulated arc therapy (VMAT)

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica

Analysis of HIV- type 1 protease and reverse transcriptase in Brazilian children failing highly active antiretroviral therapy (HAART)

The aim of this study was to evaluate the genotypic resistance profiles of HIV-1 in children failing highly active antiretroviral therapy (HAART). Forty-one children (median age = 67 months) receiving HAART were submitted to genotypic testing when virological failure was detected. cDNA was extracted from PBMCs and amplified by nested PCR for the reverse transcriptase and protease regions of the pol gene. Drug resistance genotypes were determined from DNA sequencing. According to the genotypic analysis, 12/36 (33.3%) and 6/36 (16.6%) children showed resistance and possible resistance, respectively, to ZDV; 5/36 (14%) and 4/36 (11.1%), respectively, showed resistance and possible resistance to ddI; 4/36 (11.1%) showed resistance to 3TC and D4T; and 3/36 (8.3%) showed resistance to Abacavir. A high percentage (54%) of children exhibited mutations conferring resistance to NNRTI class drugs. Respective rates of resistance and possible resistance to PIs were: RTV (12.2%, 7.3%); APV (2.4%, 12.1%); SQV(0%, 12.1%); IDV (14.6%, 4.9%), NFV (22%, 4.9%), LPV/RTV (2.4%, 12.1%). Overall, 37/41 (90%) children exhibited virus with mutations related to drug resistance, while 9% exhibited resistance to all three antiretroviral drug classes.

Clinical laboratory assessment of hepatitis C and HIV coinfected patients according to the antiretroviral therapy received

During the year of 2001, a retrospective, descriptive study in order to determine the influence of the antiretroviral therapy received by 111 HIV-HCV coinfected patients who had undergone at least one liver biopsy was conduced, 74 of them were treated with a protease inhibitor regimen (WPI), and 37 with a non-protease inhibitor regimen (NPI). The main characteristics found were: a young patient population (mean age 41 years old in both groups), composed in most part of male individuals (74.3% WPI and 51.4% NPI) with previous risk factors for both infections (WPI 93.2% and NPI 89.2%). The most significant findings included AIDS-defining disease (WPI 18.9% and NPI 13.5% of the cases), elevated hepatic enzyme levels (WPI: SGOT 52.1 and NPI 53.2), absence of liver disease-related symptoms (16.2% for both groups), average CD4 count > 350 for both groups (WPI 362.2 and NPI 378.1), predominantly low-grade fibrosis in both populations (0-2 in 63.6% of WPI patients and in 80% of NPI patients), with necro-inflammatory activity ranging from 5-7 in 51.3% and 42.9% of WPI patients and NPI patients, respectively. It is suggested a sequential biopsy to better evaluate the evolution of the hepatic disease, according to the HAART regimen received.

Screening for pulmonary tuberculosis in Teresópolis, RJ, Brazil: the search for respiratory symptomatic patients in emergency service of "Hospital das Clínicas de Teresópolis Costantino Ottaviano, Fundação Educacional Serra dos Órgãos"

The aim of the present study was to investigate the detection percentage of tuberculosis among patients that are respiratory symptomatic (TB suspects). In this work, we present the preliminary results of research carried out at "Hospital das Clínicas de Teresópolis Costantino Ottaviano da Fundação Educacional Serra dos Órgãos (FESO)" from November 2003 to April 2004. Among the 40 respiratory symptomatic individuals identified and referred to the Tuberculosis Control Program in Teresópolis, two (5.0%) were characterized as smear-positive. These results confirm reports in the literature and underscore the need for and importance of this strategy.

Hearing impairment in patients with tuberculosis from Northeast Brazil

The aim of this paper is to describe the auditory profile of subjects who were given streptomycin treatment for tuberculosis in the years 2000 and 2001, in Recife, Northeast Brazil. The Injury Notification Database at the Municipal Department of Health was consulted and 78 individuals who had been on streptomycin during the period under study were selected. Forty-two individuals were excluded, of whom five were over 59 years of age and two were under 18 years. Nineteen turned out to be deceased, 13 could not be found, two were serving prison terms and one refused to participate. As a result, only 36 subjects participated in the study. These 36 individuals were interviewed and underwent meatoscopy and audiometry. The mean age of the group under study was 38.8 years old and males predominated (79.4%). Twenty-seven patients (75%) showed hearing impairment, the bilateral sensorineural type (63.9%) being the most frequent, mainly affecting the high frequencies over 4000 Hz. In the light of findings showing a high percentage of hearing impairment complaints among users of streptomycin, this issue seems to warrant an in-depth investigation, as does the implementation of an auditory follow-up routine for patients undergoing such chemotherapy for tuberculosis.

Pulmonary thromboembolism in AIDS patient with chronic venous insufficiency, pulmonary tuberculosis and breast cancer: a case report and pathophysiology review

Recent literature reports thrombotic episodes occurring in patients with HIV infection associated with other abnormalities including neoplasms and infections predisposing to a hypercoagulable state. We report a 47-year-old woman who developed pulmonary thromboembolism in association with HIV infection, pulmonary tuberculosis and breast cancer. She was treated with rifampin, isoniazid, pyrazinamide; heparin, phenprocoumon, zidovudine, lamivudine and efavirenz. Acid fast bacilli were visualized in a sputum smear and three months after, Mycobacterium tuberculosis was isolated from lymph node biopsy during a episode of immune reconstitution. The isolated mycobacteria showed sensitivity to all first-line drugs. HIV infection, breast cancer and pulmonary tuberculosis have several mechanisms that induce hypercoagulable state and can lead to thromboembolic complications. Pulmonary thromboembolism in this patient was a diagnostic challenge because of all the other severe diseases that she experienced at the same time.

Severe Isolated Thrombocytopenia After Clopidogrel and Pentoxifylline Therapy: a Case Report

INTRODUCTION: Clopidogrel is frequently associated with thrombotic thrombocytopenic purpura, however this drug is rarely related to severe isolated thrombocytopenia. Pentoxifylline has previously been associated with thrombocytopenia only once. To the best of our knowledge, this is the first report of severe isolated thrombocytopenia after therapy with both clopidogrel and pentoxyfilline. CASE PRESENTATION: We report the case of a 79-year-old Caucasian man who presented to our facility with intermittent claudication. He had obliterative arterial disease and started therapy with clopidogrel and pentoxifylline. His basal platelet count was 194 × 109 cells/L. At three days after the start of treatment, our patient had lower limb petechia and stopped taking clopidogrel and pentoxifylline. His platelet count lowered to 4 × 109 cells/L and our patient was admitted to hospital. Our patient had purpura with no other hemorrhages or splenomegaly. Results of a blood smear were normal, and a bone marrow study showed dysmegakaryopoiesis. Antiplatelet antibody test results were negative, as were all viral serology tests. Imaging study results were normal. Our patient was given immunoglobulin but there was no sustained platelet increase, so corticotherapy was started as the next treatment step. At five months after clopidogrel and pentoxifylline were discontinued, his platelet count continued increasing even after prednisolone was tapered. CONCLUSIONS: Severe isolated thrombocytopenia may appear as a side effect when using clopidogrel and pentoxifylline. These drugs are widely used by general physicians, internists, cardiologists and vascular surgeons. We hope this report will raise awareness of the need to monitor the platelet count in patients taking these drugs.

Asymptomatic oral carriage of Candida species in HIV-infected patients in the highly active antiretroviral therapy era

Oropharyngeal candidiasis is the most common opportunistic fungal infection in individuals infected with human immunodeficiency virus. CD4+ lymphocytes count and the quantification of viral RNA in blood plasma have been found to be the main markers of HIV disease progression. The present study was conducted to evaluate Candida sp. diversity in the oral cavity of HIV-infected patients and to determine whether there was association of CD4+ cell count and viral load with asymptomatic oral Candida carriage. Out of 99 HIV-positive patients studied, 62 (62.6%) had positive culture for Candida (oral carriage) and 37 patients (37.4%) had Candida negative culture (no oral carriage). The etiologic agents most common were C. albicans and C. tropicalis. The range of CD4+ was 6-2305 cells/mm³ in colonized patients and 3-839 cells/mm³ for non-colonized patients, while the viral load was 60-90016 copies/mL for colonized patients and 75-110488 copies/mL for non colonized patients. The viral load was undetectable in 15 colonized patients and in 12 non colonized patients. Our results showed that there was no significant difference of the variables CD4+ cell count and viral load between oral candida carriage and no oral candida carriage patients.

Withdrawal of maintenance therapy for cytomegalovirus retinitis in AIDS patients exhibiting immunological response to HAART

BACKGROUND: Before the introduction of highly active antiretroviral therapy (HAART), CMV retinitis was a common complication in patients with advanced HIV disease and the therapy was well established; it consisted of an induction phase to control the infection with ganciclovir, followed by a lifelong maintenance phase to avoid or delay relapses. METHODS: To determine the safety of CMV maintenance therapy withdrawal in patients with immune recovery after HAART, 35 patients with treated CMV retinitis, on maintenance therapy, with CD4+ cell count greater than 100 cells/mm³ for at least three months, but almost all patients presented these values for more than six months and viral load < 30000 copies/mL, were prospectively evaluated for the recurrence of CMV disease. Maintenance therapy was withdrawal at inclusion, and patients were monitored for at least 48 weeks by clinical and ophthalmologic evaluations, and by determination of CMV viremia markers (antigenemia-pp65), CD4+/CD8+ counts and plasma HIV RNA levels. Lymphoproliferative assays were performed on 26/35 patients. RESULTS: From 35 patients included, only one had confirmed reactivation of CMV retinitis, at day 120 of follow-up. No patient returned positive antigenemia tests. No correlation between lymphoproliferative assays and CD4+ counts was observed. CONCLUSION: CMV retinitis maintenance therapy discontinuation is safe for those patients with quantitative immune recovery after HAART.

Physical therapy with drug treatment in bell palsy: a focused review

ABSTRACT: The physical therapy (PT) associated with standard drug treatment (SDT) in Bell palsy has never been investigated. Randomized controlled trials or quasirandomized controlled trials have compared facial PT (except treatments such as acupuncture and osteopathic) combined with SDT against a control group with SDT alone. Participants included those older than 15 yrs with a clinical diagnosis of Bell palsy, and the primary outcome measure was motor function recovery by the House-Brackmann scale. The methodologic quality of each study was also independently assessed by two reviewers using the PEDro scale. Four studies met the inclusion criteria. Three trials indicate that PT in association with SDT supports higher motor function recovery than SDT alone between 15 days and 1 yr of follow-up. On the other hand, one trial showed that electrical stimulation added to conventional PT with SDT did not influence treatment outcomes. The present review suggests that the current practice of Bell palsy treatment by PT associated with SDT seems to have a positive effect on grade and time recovery compared with SDT alone. However, there is very little quality evidence from randomized controlled trials, and such evidence is insufficient to decide whether combined treatment is beneficial in the management of Bell palsy.

Aids-related progressive multifocal leukoencephalopathy: a retrospective study in a referral center in São Paulo, Brazil

Few data are available about progressive multifocal leukoencephalopathy (PML) in patients with acquired immunodeficiency syndrome (AIDS) from Brazil. The objectives of this study were to describe the main features of patients with PML and estimate its frequency among AIDS patients with central nervous system (CNS) opportunistic diseases admitted to the Instituto de Infectologia Emílio Ribas, São Paulo, Brazil, from April 2003 to April 2004. A retrospective and descriptive study was performed. Twelve (6%) cases of PML were identified among 219 patients with neurological diseases. The median age of patients with PML was 36 years and nine (75%) were men. Nine (75%) patients were not on antiretroviral therapy at admission. The most common clinical manifestations were: focal weakness (75%), speech disturbances (58%), visual disturbances (42%), cognitive dysfunction (42%), and impaired coordination (42%). The median CD4+ T-cell count was 45 cells/µL. Eight (67%) of 12 patients were laboratory-confirmed with PML and four (33%) were possible cases. Eleven (92%) presented classic PML and only one case had immune reconstitution inflammatory syndrome (IRIS)-related PML. In four (33%) patients, PML was the first AIDS-defining illness. During hospitalization, three patients (25%) died as a result of nosocomial pneumonia and nine (75%) were discharged to home. Cases of PML were only exceeded by cases of cerebral toxoplasmosis, cryptococcal meningoencephalitis, and CNS tuberculosis, the three more frequent neurologic opportunistic infections in Brazil. The results of this study suggest that PML is not an uncommon HIV-related neurologic disorder in a referral center in Brazil.

Mesenchymal Stem Cell Therapy in Heart Disease

Cardiovascular disease is among the main causes of mortality and morbidity worldwide. Despite significant advances in medical and interventional therapy, the prognosis of conditions such as ischemic heart disease is still dismal. There is thus a need to investigate new therapeutic tools, one of which is stem cell therapy. Hematopoietic stem cells are the most studied type, and the fact that their biology is relatively well understood has led to their being used in preclinical research and clinical trials. However, the results of some of these studies have been controversial, which has opened the way for studies on other cell types, such as mesenchymal stem cells. These cells have immunomodulatory properties which suggest that they have therapeutic potential in cardiology. In the present article, the authors review the state of the art regarding mesenchymal stem cells, from basic and translational research to their use in clinical trials on ischemic heart disease, heart failure and arrhythmias, and discuss possible future uses.

Effects of tissue handling and processing steps on PCR for detection of Mycobacterium tuberculosis in formalin-fixed paraffin-embedded samples

Development and standardization of reliable methods for detection of Mycobacterium tuberculosis in clinical samples is an important goal in laboratories throughout the world. In this work, lung and spleen fragments from a patient who died with the diagnosis of miliary tuberculosis were used to evaluate the influence of the type of fixative as well as the fixation and paraffin inclusion protocols on PCR performance in paraffin embedded specimens. Tissue fragments were fixed for four h to 48 h, using either 10% non-buffered or 10% buffered formalin, and embedded in pure paraffin or paraffin mixed with bee wax. Specimens were submitted to PCR for amplification of the human beta-actin gene and separately for amplification of the insertion sequence IS6110, specific from the M. tuberculosis complex. Amplification of the beta-actin gene was positive in all samples. No amplicons were generated by PCR-IS6110 when lung tissue fragments were fixed using 10% non-buffered formalin and were embedded in paraffin containing bee wax. In conclusion, combined inhibitory factors interfere in the detection of M. tuberculosis in stored material. It is important to control these inhibitory factors in order to implement molecular diagnosis in pathology laboratories.