Resumo em Inglês:

Although cellular immunity is essential for the elimination of human papillomavirus (HPV), the mechanisms involved are still poorly understood. We summarize the main mechanisms involved in cellular immune response to infections caused by HPV. Immunotherapies for HPV-related cancers require the disruption of T-cell response control mechanisms, associated with the stimulation of the Th1 cytokine response.

Resumo em Inglês:

A follow-up study was made of 94 chronic hepatitis C patients at a hepatitis clinic in Brazil, after interferon alpha (IFN-alpha) therapy, to determine the influence of anti-interferon antibodies on treatment outcome. Patients diagnosed as having chronic hepatitis C, confirmed by PCR (HCV RNA) and liver biopsy, were treated with interferon alpha 2a or 2b for at least six months, and were followed up for 24 weeks after termination of treatment in order to assess biochemical, virological and clinical pathology responses. Only 6% of the 94 patients developed anti-IFN antibodies, 70% presented a biochemical response and 23% maintained a sustained virological response. Clinical evaluation revealed that in only 2 patients was there progression of fibrosis; the necro-inflammatory score indicated that 72% maintained the same activity, 12% had worsening necro-inflammatory activity, and the remaining 16% had decreased activity. There was no significant correlation of demographic and laboratory variables with levels of anti-interferon antibodies. Similarly, biochemical and virological responses were not influenced by anti-interferon antibodies. Multivariate analysis by logistic regression revealed that clinical pathological parameters, staging and necro-inflammatory activity did not influence the response to the virus.

Resumo em Inglês:

During their academic activities, undergraduate nursing students are exposed to contamination by bloodborne pathogens, as well as by others found in body fluids, among which are the Human Immunodeficiency (HIV), Hepatitis B and C viruses. We developed a profile of victimized students, characterizing accidents with biological material occurring among undergraduate nursing students at a public university in São Paulo State, Brazil. We identified the main causes and evaluated the conduct adopted by students and their reactions and thoughts concerning the accidents. Seventy-two accidents were identified, of which 17% involved potentially contaminated biological material. Needles were the predominant cause of accidents. The most frequently involved topographic areas were the fingers. Only five students reported the accidents and sought medical care. Among these, two students were advised to begin prophylactic treatment against HIV infection by means of antiretroviral drugs. It was found that the risk of accidents is underestimated and that strategies such as formal teaching and continual training are necessary in order to make students aware of biosafety measures.

Resumo em Inglês:

The alarming emergence and spread of antimicrobial resistance among common bacteria threatens the effectiveness of therapy for many infections. Surveillance of antimicrobial resistance is essential to identify the major problems and guide adequate control measures. Several resistance surveillance programs have been implemented in North America and Europe in the last decade; however, very few programs have assessed antimicrobial resistance in Latin American countries. The SENTRY Antimicrobial Surveillance Program was initiated in 1997 and represents the most comprehensive surveillance program in place at the present time worldwide. The SENTRY Program collects consecutive isolates from clinically documented infections in more than 80 medical centers worldwide (10 in Latin America). The isolates are collected according to the type of infection (objectives) and susceptibility tested in a central microbiology laboratory by reference broth microdilution methods according to NCCLS guidelines. The Program also incorporated molecular typing (ribotyping and PFGE) and resistance mechanism analysis of selected isolates. In this report we present a very broad analysis of the data generated by testing almost 20,000 bacterial isolates against more than 30 antimicrobial agents. The susceptibility results (MIC50, MIC90 and % susceptible) are presented in 11 tables according to the organism and site of infection. The data from Brazil, as well as the data from isolates collected in 2001, are analyzed separately. This report allows the evaluation of the activities numerous antimicrobial agents against clinical isolates collected in Latin American countries.

Resumo em Inglês:

Staphylococcus aureus is a pathogen that has been associated with nosocomial infections since the preantibiotic era. Since the introduction of antibiotics in medical practice in the 1940 s, methicillin-resistant S. aureus (MRSA) strains have been emerging in various parts of the world. In view of the important role of the phagocytic system in the defense against this bacteria, we decided to study phagocytosis by neutrophils and monocytes of an epidemic MRSA strain in São Paulo, Brazil, in comparison with methicillin-sensitive strains. Complement system opsonins are fundamental for efficient ingestion of the resistant and sensitive strains by both types of phagocytes. We found no association of the opsonic requirement of the MRSA strain with the multiresistance phenotype. On the other hand, the MRSA strain was found to be more resistant to the effector mechanisms of neutrophils than both sensitive strains when opsonized with fresh serum, despite the phagocytosis results. This fact suggests that the intracellular killing of S. aureus is an additional parameter of bacterial virulence, but new approaches must be implemented to study the interactions of this MRSA strain with phagocytes in order to investigate the possible factors involved in its behavior in response to neutrophil effector mechanisms.

Resumo em Inglês:

Community-acquired pneumonia is very common, but some of the cases do require hospitalization for treatment, particularly when older patients and/or co-morbidities are involved; both "typical" and "atypical" respiratory pathogens take part etiologically, and there is increasing concern about the emergence of resistance. There is interest in therapeutic options that can: a) comprehend such a spectrum of bacteria and resistance; b) allow parenteral to oral sequential treatment. We made a multicenter, prospective and randomized trial to compare the "standard" treatment of ceftriaxone IV alone or in combination with erythromycin IV, followed by clarithromycin PO (ceftriaxone treatment arm), with gatifloxacin IV, followed by oral administration (gatifloxacin treatment arm). The need for hospitalization was based on clinical criteria as judged by the investigators. Standardized criteria for diagnosis and follow-up were employed. Fifty-six patients were enrolled, with 48% over 65 years old, and there were frequent co-morbidities. Of these, 51 were clinically evaluable, 26 in the gatifloxacin and 25 in the ceftriaxone arm, with comparable success rates, 92% and 88%, respectively, even when major prognostic factors were considered. There were no serious adverse events or significant laboratory value changes attributable to the study drugs. Gatifloxacin as monotherapy (initially IV then orally until completion of treatment) was shown to be effective and safe, comparable to ceftriaxone IV alone or in combination with a macrolide (initially IV then orally until completion of treatment), in empirical therapy for community-acquired pneumonias, for patients that, at the physician s discretion, require initial treatment as inpatients.

Resumo em Inglês:

Macrophages exposed to 10 mug/mL citrinin (CTR) or 0.01 mug CTR mixed with 0.04 mug aflatoxin B1 (AFB1) for a period of 2 h at 37ºC, were infected with 10(6) Toxoplasma gondii tachyzoites/muL. The parasites were treated with mycotoxins (2 h at 37ºC) before being added to the macrophage culture. The number of tachyzoites was quantified 2, 24, 48, 72 and 96 h after infection. During the first 2 hours, 59% infectivity was observed in the control. After exposure to CTR or the mixture of toxins (CTR-AFB1), macrophages were infected with 77.5% and 75% of the inoculated tachyzoites, respectively. Similarly, 72.3% of the cells were infected when cultured together with previously treated parasites. The treatment with CTR-AFB1 gave rise to 2.9 times more tachyzoites than the control at 72 h. An increased number of parasites was recovered from macrophages exposed to CTR after 96 h, and to CTR-AFB1 after 72 h of culture; The number of tachyzoites recovered from the supernatant was 1.94 and 2.06 times higher, respectively, than in the control (5 x 10(5) ± 0.054 /mL).

Resumo em Inglês:

A Klebsiella pneumoniae strain was isolated from the urine of a patient at one of the centers participating in the 2001 edition of the MYSTIC program in Brazil. The initial phenotypic findings of the isolated K. pneumoniae presented an unusual MIC of 8 mug/mL to meropenem, 2 mug/mL to imipenem, elevated MICs to broad spectrum cephalosporins (ceftazidime/cefotaxime/cefepime MIC > 256 mug/mL), aminoglycosides (gentamycin > 256 mug/mL and tobramycin = 48 mug/mL), piperacillin/tazobactam (MIC > 256 mug/mL) and susceptibility to ciprofloxacin (MIC = 0.25 mug/mL). The strain also tested positive for ESBL production with double-disk and E-test methodologies. More detailed investigation revealed that the strain produced a SHV-4 type enzyme and also lacked a 36 kDa outer membrane porin.

Resumo em Inglês:

Tuberculosis of the cystic duct lymph node associated with cholelithiasis is rare. We report a case of a 40 year-old woman with this pathology. She presented with anorexia, biliary colic, postprandial fullness and fever. Imaging studies revealed cholelithiasis and several visible portal lymph nodes. Cholecystectomy was performed and histopathological examination showed tuberculosis of the cystic duct lymph node without affecting the gallbladder. The presence of gallstones and lymphadenopathy in computed tomography, associated with persistent fever and symptoms that resemble cholecystitis, should cause suspicion of tuberculosis. However, diagnosis is usually achieved by microscopic appearance of caseating granulomas and isolation of Mycobacterium tuberculosis. The treatment in this case consisted of cholecystectomy and antitubercular chemotherapy.

Resumo em Inglês:

Toxoplasmic encephalitis is the most common cerebral mass lesion in patients with AIDS. The definitive diagnosis requires direct demonstration of the tachyzoite form of Toxoplasma gondii in cerebral tissue. The presumptive diagnosis is based on serology, clinical and radiological features, and on response to anti-Toxoplasma therapy. Typically, patients have a subacute presentation of focal neurological signs, with multiple lesions in computed tomography (CT) or magnetic resonance imaging (MRI). However, the neurological and CT scan spectrum is broad. We report a case of toxoplasmic encephalitis in a heterosexual man without prior history of HIV infection. He was admitted with four days of headache, confusion, and new onset of seizures. His brain CT disclosed no alterations and MRI revealed multiple lesions. Empirical specific anti-Toxoplasma therapy was initiated and the patient experienced excellent clinical and radiological improvement. His HIV tests were positive and the CD4+ cell count was 74 cells/ml (8.5 %). On follow up, three months later, the general state of the patient was good, without neurological sequelae and with a normal MRI. We concluded that toxoplasmic encephalitis should be considered in the differential diagnosis of meningoencephalitis in sexually active individuals, including cases without prior history or suspicion of HIV infection, and no abnormalities on CT scan.