New hydrazides derivatives of isoniazid against Mycobacterium tuberculosis: Higher potency and lower hepatocytotoxicity.

Tuberculosis (TB) is one of the leading causes of death worldwide. The emergence of multi-drug resistant strains of Mycobacterium tuberculosis (Mtb) and TB-HIV co-infection are major public health challenges. The anti-TB drugs of first choice were developed more than 4 decades ago and present several adverse effects, making the treatment of TB even more complicated and the development of new chemotherapeutics for this disease imperative. In this work, we synthesized two series of new acylhydrazides and evaluated their activity against different strains of Mtb. Derivatives of isoniazid (INH) showed important anti-Mtb activity, some being more potent than all anti-TB drugs of first choice. Moreover, three compounds proved to be more potent than INH against resistant Mtb. The Ames test showed favorable results for two of these substances compared to INH, one of which presented expressly lower toxicity to HepG2 cells than that of INH. This result shows that this compound has the potential to overcome one of the main adverse effects of this drug.

Study of heavy metal content in HIV-infected blood using X-ray fluorescence technique.

The objective of this work was to study the sensitivity of energy dispersion X-ray fluorescence (EDXRF) in the elemental analysis of blood samples. Using this technique, blood samples (0.03 ml) from infected and non-infected patients were evaluated. It was possible to point out that blood samples from patients infected by HIV present deficiencies in Fe, Zn and K concentrations when compared to non-infected ones. The results emphasized EDXRF as a important technique for detection of heavy metals in blood using small volume of samples, without the need of any specific sample pre-preparation, and leading to an important reduction in the final cost of the analyses.

Effect of highly active antiretroviral therapy on cytomegalovirus antigenaemia in AIDS patients.

To assess the effect of highly active antiretroviral therapy (HAART) on cytomegalovirus (CMV) antigenaemia in AIDS patients, 70 patients with CD4+ cell counts < or = 50/mm3 and positive anti-(CMV) immunoglobulin G (IgG) were tested at 15-30 day intervals for CMV antigenaemia. We selected those patients who had been followed up for more than 3 months. Three patient profiles were defined: A, followed up before the introduction of HAART; B, followed up before and after the use of HAART; and C, followed up after the use of HAART. Thirty-nine patients were included, 12 in group A, 17 in group B, and 10 in group C. Group A patients presented a lower median CD4+ cell count compared with groups B and C patients (9, 122 and 127 cells/mm3, respectively), with the increase in the last 2 groups being related to the use of HAART (P<0.001). A lower proportion of positive antigenaemia was observed in group B after the introduction of HAART compared with the time before HAART (P=0.02). HAART caused an immunological improvement and was found to be associated with negativity of CMV antigenaemia.

Cytomegalovirus infection in children with Down syndrome in a day-care center in Brazil.

This study evaluates the transmission of CMV infection in 120 children aged 1 to 15 years with Down syndrome who attended a day-care center for handicapped children in São Paulo, Brazil. A blood sample was obtained from each children at the beginning of the study for detection of IgG and IgM cytomegalovirus (CMV) antibodies by an immunofluorescence assay. Samples of saliva and urine were obtained every 3 months from the children with CMV antibodies to detect shedding of the virus by culture in human foreskin fibroblasts, by detection of pp65 CMV-antigen and by a nested PCR assay. The prevalence of anti CMV-IgG antibodies was 76.6% (92/120), and IgM anti-CMV antibodies were detected in 13% (12/92) of the seropositive children. During the first viral evaluation, CMV was detected in the urine and/or saliva in 39/90 (43.3%) of the seropositive children. In the second and third evaluations, CMV was detected in 41/89 (46%) and in 35/89 (39.3%) children, respectively. Detection of CMV was shown both in urine and saliva in 28/39 (71.8%), 19/41(46.3%) and 20/35 (57.1%) of the children excreting the virus, respectively. Additionally, in 3(3/4)9 (67.4%) of the excreters CMV could be demonstrated in urine or saliva in at least two out of the three virological evaluations carried out sequentially in a six month period. Of the 28 initially seronegative children, 26 were re-examined for anti-CMV IgG antibodies about 18 months after the negative sample; seroconversion was found in 10/26 (38.5%). Taking all 536 samples of urine or saliva examined by virus culture and pp65 antigen detection during the study into account, 159 (29.6%) were positive by virus culture and 59 (11%) gave a positive result with the pp65 assay. These data demonstrate the high prevalence of CMV shedding and the high risk of CMV infection in children with Down syndrome attending a day-care center for mentally handicapped patients. The virus culture was more sensitive than the pp65 CMV antigen assay for CMV detection in both urine and saliva samples.