Comparison of the epidemiology, profile of mutations, and clinical response to antiretrovirals among subtypes B and F of the human immunodeficiency virus type 1

The authors compared demographic aspects and profile of mutations in 80 patients with subtypes B and F of human immunodeficiency type 1 (HIV-1). Genotyping of the pol region of the reverse transcriptase was performed using the ViroSeqTM Genotyping System. A total of 61 (76.2%) patients had subtype B and 19 (23.8%) subtype F of the HIV-1. Subtype F tended to be more frequent in heterosexuals and women with a low educational level, but without statistical significance. The frequency of mutations related to nucleoside reverse transcriptase inhibitors and protease inhibitors (PI) was the same in the two subtypes, but mutations related to PI at the codons 63, 77, and 71 were more frequent in subtype B, while mutations at the codons 36 and 20 predominated in subtype F. Sixty-two of the 80 patients infected with subtypes B and F were submitted to antiretroviral therapy for an average of 18-22 months. Undetectable viral loads at the end of follow-up were similar in the two groups, representing 63.8% of subtype B and 73.3% of subtype F (p = 0.715). CD4 lymphocyte counts before and after treatment were similar in the two groups. This study, despite pointing to possible epidemiological and genetic differences among subtypes B and F of HIV-1, suggests that the use of highly active antiretroviral therapy is equally effective against these subtypes.

Anti-human immunodeficiency virus type 1 humoral immune response and highly active antiretroviral treatment

Highly active antiretroviral treatment (HAART) of human immunodeficiency type 1 (HIV-1) infection is very effective in controlling infection, but elimination of viral infection has not been achieved as yet, and upon treatment interruption an immediate rebound of viremia is observed. A combination of HAART with an immune stimulation might allow treatment interruption without this rebounding viremia, as the very low viremias observed with successful HAART may be insufficient to permit maintenance of a specific anti-HIV-1 immune response. The objective of this study was to compare the humoral immune response of individuals undergoing successful HAART (NF=no failure) with that of individuals with evidence of failure of therapy (FT) and to verify if the viremia peaks observed in individuals with therapy failure would act as a specific stimulus for the humoral anti-HIV-1 immune response. Antibodies binding to gp120 V3 genotype consensus peptides were more frequently observed for FT, mainly against peptides corresponding to sequences of genotypes prevalent in the Rio de Janeiro city area, B and F. HIV-1 neutralization of HIV-1 IIIB and of four primary isolates from Rio de Janeiro was less frequently observed for plasma from the NF than the FT group, but this difference was more expressive when plasma from individuals with detectable viremia were compared to that of individuals with undetectable viral loads in the year before sample collection. Although statistically significant differences were observed only in some specific comparisons, the study indicates that presence of detectable viremia may contribute to the maintenance of a specific anti-HIV-1 humoral immune response.

Control of Mycobacterium fortuitum and Mycobacterium intracellulare infections with respect to distinct granuloma formations in livers of BALB/c mice

Mycobacterium fortuitum is a rapidly growing nontuberculous Mycobacterium that can cause a range of diseases in humans. Complications from M. fortuitum infection have been associated with numerous surgical procedures. A protective immune response against pathogenic mycobacterial infections is dependent on the granuloma formation. Within the granuloma, the macrophage effector response can inhibit bacterial replication and mediate the intracellular killing of bacteria. The granulomatous responses of BALB/c mice to rapidly and slowly growing mycobacteria were assessed in vivo and the bacterial loads in spleens and livers from M. fortuitum and Mycobacterium intracellulare-infected mice, as well as the number and size of granulomas in liver sections, were quantified. Bacterial loads were found to be approximately two times lower in M. fortuitum-infected mice than in M. intracellulare-infected mice and M. fortuitum-infected mice presented fewer granulomas compared to M. intracellulare-infected mice. These granulomas were characterized by the presence of Mac-1+ and CD4+ cells. Additionally, IFN-γmRNA expression was higher in the livers of M. fortuitum-infected mice than in those of M. intracellulare-infected mice. These data clearly show that mice are more capable of controlling an infection with M. fortuitum than M. intracellulare. This capacity is likely related to distinct granuloma formations in mice infected with M. fortuitum but not with M. intracellulare.

Immune response to Leishmania (Leishmania) chagasi infection is reduced in malnourished BALB/c mice

Protein-energy malnutrition and micronutrient deficiencies may down-regulate immune response and increase morbidity and mortality due to infection. In this study, a murine model was used to study the effects of protein, iron and zinc deficiencies on the immune response to Leishmania (Leishmania) chagasi infection. Mice were initially fed a standard diet or with a diet containing 3% casein but deficient in zinc and iron. After malnutrition was established, mice were inoculated with L. chagasiand sacrificed four weeks later in order to evaluate liver and spleen parasite loads and serum biochemical parameters. Significant decreases in liver and spleen weight, an increase in the parasite loads in these organs and decreases in serum protein and glucose concentrations in malnourished animals were observed. Furthermore, the production of interferon-gamma by spleen cells from infected malnourished mice stimulated by Leishmaniaantigen was significantly lower compared with that in control diet mice. These data suggest that malnutrition alters the immune response to L. chagasiinfection in the BALB/c model and, in association with the effects on biochemical and anatomical parameters of the host, favored increases in the parasite loads in the spleens and livers of these animals.

Kinetoplastid membrane protein-11 exacerbates infection with Leishmania amazonensis in murine macrophages

In Leishmania amazonensis, kinetoplastid membrane protein-11 (KMP-11) expression increases during metacyclogenesis and is higher in amastigotes than in promastigotes, suggesting a role for this protein in the infection of the mammalian host. We show that the addition of KMP-11 exacerbates L. amazonensis infection in peritoneal macrophages from BALB/c mice by increasing interleukin (IL)-10 secretion and arginase activity while reducing nitric oxide (NO) production. The doses of KMP-11, the IL-10 levels and the intracellular amastigote loads were strongly, positively and significantly correlated. The increase in parasite load induced by KMP-11 was inhibited by anti-KMP-11 or anti-IL-10 neutralising antibodies, but not by isotype controls. The neutralising antibodies, but not the isotype controls, were also able to significantly decrease the parasite load in macrophages cultured without the addition of KMP-11, demonstrating that KMP-11-induced exacerbation of the infection is not dependent on the addition of exogenous KMP-11 and that the protein naturally expressed by the parasite is able to promote it. In this study, the exacerbating effect of KMP-11 on macrophage infection with Leishmania is for the first time demonstrated, implicating it as a virulence factor in L. amazonensis. The stimulation of IL-10 production and arginase activity and the inhibition of NO synthesis are likely involved in this effect.

Hepatitis C virus quantification in serum and saliva of HCV-infected patients

The hepatitis C virus (HCV) can be detected in blood and other bodily fluids, such as saliva, semen and gastric juices. The aim of this study was to compare the HCV viral loads in the serum and saliva of infected patients. Twenty-nine patients with detectable HCV RNA in their serum and saliva were included in this study. The HCV viral loads were determined through quantitative real-time polymerase chain reactions. The median viral RNA levels were 5.78 log10 copies in the serum and 3.32 log10 copies in the saliva. We observed that the salivary HCV viral load was significantly lower than the viral load in the serum. Further studies are required to understand the role of saliva in the diagnosis, management and potential transmission of HCV.

Prevalence of occult hepatitis B virus infection in kidney transplant recipients

In this cross-sectional study, 207 hepatitis B surface antigen (HBsAg)-negative kidney transplant recipients were evaluated based on demographic and epidemiological data and on the levels of serological markers of hepatitis B virus (HBV) and hepatitis C virus infection and liver enzymes. Patients with HBV or human immunodeficiency virus infection were excluded. Sera were analysed for the presence of HBV-DNA. HBV-DNA was detected in two patients (1%), indicating occult hepatitis B (OHB) infection (the HBV-DNA loads were 3.1 and 3.5 IU/mL in these patients). The results of the liver function tests were normal and no serological markers indicative of HBV infection were detected. The prevalence of OHB infection was low among kidney transplant recipients, most likely due to the low HBsAg endemicity in the general population of the study area.

Social and immunological differences among uninfected Brazilians exposed or unexposed to human immunodeficiency virus-infected partners

Understanding the social conditions and immunological characteristics that allow some human immunodeficiency virus (HIV)-exposed patients to remain uninfected represents an on-going challenge. In this study, the socio-demographic and sexual behaviour characteristics and immune activation profiles of uninfected individuals exposed to HIV-infected partners were investigated. A confidential and detailed questionnaire was administered and venous blood was tested using HIV-1/enzyme immunoassays, plasma HIV-1 RNA levels/bDNA and immunophenotyping/flow cytometry to determine the frequencies of CD4 and CD8 T cells expressing activation markers. The data analysis showed significant differences (p < 0.05) for immune parameters in individuals who were uninfected, albeit exposed to HIV-infected partners, compared with unexposed individuals. In particular, the exposed, uninfected individuals had a higher frequency (median, minimum-maximum) of CD4+HLA-DR+ (4.2, 1.8-6.1), CD8+HLA-DR+ (4.6, 0.9-13.7), CD4+CD45RO+ (27.5, 14.2-46.6), CD4+CD45RO+CD62L+ (46.7, 33.9-67.1), CD8+CD45RA+HLA-DR+ (12.1, 3.4-35.8) and CD8+CD45RO+HLA-DR+ (9.0, 3.2-14.8) cells, a decreased percentage of CD8+CD28+ cells (11.7, 4.5-24.0) and a lower cell-surface expression of Fcγ-R/CD16 on monocytes (56.5, 22.0-130.0). The plasma HIV-1 RNA levels demonstrated detectable RNA virus loads in 57% of the HIV-1+ female partners. These findings demonstrate an activation profile in both CD4 and CD8 peripheral T cells from HIV-1 exposed seronegative individuals of serodiscordant couples from a referral centre in Belo Horizonte, state of Minas Gerais.

Optimisation of a quantitative polymerase chain reaction-based strategy for the detection and quantification of human herpesvirus 6 DNA in patients undergoing allogeneic haematopoietic stem cell transplantation

Human herpesvirus 6 (HHV-6) may cause severe complications after haematopoietic stem cell transplantation (HSCT). Monitoring this virus and providing precise, rapid and early diagnosis of related clinical diseases, constitute essential measures to improve outcomes. A prospective survey on the incidence and clinical features of HHV-6 infections after HSCT has not yet been conducted in Brazilian patients and the impact of this infection on HSCT outcome remains unclear. A rapid test based on real-time quantitative polymerase chain reaction (qPCR) has been optimised to screen and quantify clinical samples for HHV-6. The detection step was based on reaction with TaqMan® hydrolysis probes. A set of previously described primers and probes have been tested to evaluate efficiency, sensitivity and reproducibility. The target efficiency range was 91.4% with linearity ranging from 10-106 copies/reaction and a limit of detection of five copies/reaction or 250 copies/mL of plasma. The qPCR assay developed in the present study was simple, rapid and sensitive, allowing the detection of a wide range of HHV-6 loads. In conclusion, this test may be useful as a practical tool to help elucidate the clinical relevance of HHV-6 infection and reactivation in different scenarios and to determine the need for surveillance.

A non-enteric adenovirus A12 gastroenteritis outbreak in Rio de Janeiro, Brazil

A gastroenteritis outbreak that occurred in 2013 in a low-income community in Rio de Janeiro was investigated for the presence of enteric viruses, including species A rotavirus (RVA), norovirus (NoV), astrovirus (HAstV), bocavirus (HBoV), aichivirus (AiV), and adenovirus (HAdV). Five of nine stool samples (83%) from patients were positive for HAdV, and no other enteric viruses were detected. Polymerase chain reaction products were sequenced and subjected to phylogenetic analysis, which revealed four strains and one strain of non-enteric HAdV-A12 and HAdV-F41, respectively. The HAdV-A12 nucleotide sequences shared 100% nucleotide similarity. Viral load was assessed using a TaqMan real-time PCR assay. Stool samples that were positive for HAdV-A12 had high viral loads (mean 1.9 X 107 DNA copies/g stool). All four patients with HAdV-A12 were < 25 months of age and had symptoms of fever and diarrhoea. Evaluation of enteric virus outbreaks allows the characterisation of novel or unique diarrhoea-associated viruses in regions where RVA vaccination is routinely performed.

Workloads and strain process in Community Health Agents

ABSTRACT OBJECTIVE To identify the workloads present in the work activities of community health agents (CHAs) and the resulting strain processes. METHOD A descriptive, exploratory, cross-sectional and quantitative study conducted with 137 CHAs. Data were collected through a questionnaire and interview guided by the health surveillance software called SIMOSTE (Health Monitoring System of Nursing Workers), following the ethical codes of the current law. RESULTS In total, were identified 140 workloads involved in 122 strain processes, represented by the occurrence of health problems of the CHAs. The mechanical (55.00%) and biological (16.43%) loads stood out. The most common strain processes were the external causes of morbidity and mortality (62.31%) and diseases of the musculoskeletal system and connective tissue (10.66%). CONCLUSION From the identified overloads, it became evident that all workloads are present in the work process of CHAs, highlighting the mechanical load, represented mainly by external causes of morbidity and mortality that are related to occupational accidents.

Soil compaction and eucalyptus growth in response to forwarder traffic intensity and load

During timber exploitation in forest stands harvesting machines pass repeatedly along the same track and can cause soil compaction, which leads to soil erosion and restricted tree root growth. The level of soil compaction depends on the number of passes and weight of the wood load. This paper aimed to evaluate soil compaction and eucalyptus growth as affected by the number of passes and wood load of a forwarder. The study was carried out in Santa Maria de Itabira county, Minas Gerais State - Brazil, on a seven-year-old eucalyptus stand planted on an Oxisol. The trees were felled by chainsaw and manually removed. Plots of 144 m² (four rows 12 m long in a 3 x 2 m spacing) were then marked off for the conduction of two trials. The first tested the traffic intensity of a forwarder which weighed 11,900 kg and carried 12 m³ wood (density of 480 kg m-3) and passed 2, 4, and 8 times along the same track. In the second trial, the forwarder carried loads of 4, 8, and 12 m³ of wood, and the machine was driven four times along the same track. In each plot, the passes affected four rows. Eucalyptus was planted in 30 x 30 x 30 cm holes on the compacted tracks. The soil in the area is clayey (470 clay and 440 g kg-1 sand content) and at depths of 0-5 cm and 5-10 cm, respectively, soil organic carbon was 406 and 272 g kg-1 and the moisture content during the trial 248 and 249 g kg-1. These layers were assessed for soil bulk density and water-stable aggregates. The infiltration rate was measured by a cylinder infiltrometer. After 441 days the measurements were repeated, with additional analyses of: soil organic carbon, total nitrogen, N-NH4+, N-NO3-, porosity, and penetration resistance. Tree height, stem diameter, and stem dry matter were measured. Forwarder traffic increased soil compaction, resistance to penetration and microporosity while it reduced the geometric mean diameter, total porosity, macroporosity and infiltration rate. Stem dry matter yield and tree height were not affected by soil compaction. Two passes of the forwarder were enough to cause the disturbances at the highest levels. The compaction effects were still persistent 441 days after forwarder traffic.

Assessment of the soil compaction of two ultisols caused by logging operations

The impact of wood loads on bulk density and preconsolidation pressure and of harvester and forwarder traffic on rut depth, bulk density and preconsolidation pressure of two Ultisols were examined in this study. Our objective was to quantify the threshold beyond which significant soil compaction and rutting would occur. This study was carried out in the county of Eunápolis, state of Bahia, Brazil, (16 º 23 ' 17 '' S and 39 º 10 ' 06 '' W; altitude 80 m asl) in two Ultisols (PAd2 and PAd3) with different texture classes, in experimental areas with eucalypt plantation. The study involved measurements at the wood load site and machine driving at specific locations in the forest during logging operations. The treatments consisted of one harvester pass and, 8, 16 and 40 passes of a fully loaded forwarder. Thresholds were established based on the rut depth and percentage of preconsolidation pressure values in the region of additional soil compaction defined in the bearing capacity model. The percentage of soil samples with values of preconsolidation pressure in the region of additional soil compaction indicated a greater susceptibility of PAd3 than of PAd2 to soil compaction. The threshold levels established here based on preconsolidation pressure and rut depth indicated that no more than eight forwarder passes should be allowed in loading operations in order to minimize soil compaction.

Zoneamento ambiental aplicado à conservação do solo e da água

O zoneamento ambiental auxilia na gestão do solo e da água, pois fornece informações de uso e manejo do solo de forma adequada. Assim, propõe-se neste estudo: (i) a aplicação do zoneamento ambiental, baseado em valores de perda de solo, tolerância à perda de solo e à legislação ambiental; e (ii) etapa de monitoramento das características quali-quantitativas dos cursos d'água a partir do uso de curvas Total Maximum Daily Loads (TMDL). O estudo foi realizado na bacia hidrográfica do ribeirão Salobra, localizada na transição entre os biomas Cerrado e Pantanal. A partir do cruzamento dos planos de informação, obteve-se a divisão da área em cinco zonas de uso do solo, determinadas de acordo com a conservação e preservação da vegetação nativa, ocorrência de áreas úmidas e nascentes, uso adequado do solo e recuperação de áreas erodidas. Paralelamente, as curvas TMDL foram obtidas a partir da curva de permanência e de padrões de qualidade da água. Verificou-se que cerca de 6 % da área em estudo apresentou perda de solo superior ao limite tolerável e foi definida como área prioritária de recuperação no contexto do planejamento ambiental. O método aplicado permitiu a determinação de zonas específicas de uso do solo, identificação de irregularidades e de prioridades de conservação do solo. Além disso, as curvas TMDL constituem boa alternativa de monitoramento da água, pois produzem informações em condições críticas do corpo d'água.

Módulo eletrônico de controle para válvulas solenóides

This technical note describes a new and simple electronic circuit for driving solenoid valves. The circuit is based on a single integrated circuit DRV103, which is able to drive resistive or inductive loads up to 1.5 A. Switching of 12-V loads can be controlled by TTLlevel signals in two distinct steps. Initially, 12 V is applied during 110 ms, followed by 4.2 V RMS until the end of the activation TTL pulse. This mode of operation is particularly suitable to drive solenoids, because it requires a higher voltage to start and a lower maintenance voltage. By using this circuit, power consumption and heating are reduced and the solenoid lifetime is enhanced. Moreover, this circuit is specially appropriated to build computercontrolled solenoid valves systems.