Tolerability and efficacy of single dose albendazole,diethylcarbamazine citrate (DEC) or co-administration of albendazole with DEC in the clearance of <Emphasis Type="Italic">Wuchereria bancrofti</Emphasis>in asymptomatic microfilaraemic volunteers in Pondicherry,South India: a hospital-based study

Background  

The tolerability and efficacy of single dose albendazole (400 mg), diethylcarbamazine citrate (DEC) (6 mg/kg bodyweight) or co-administration of albendazole (400 mg) + DEC (6 mg/kg bodyweight) was studied in 54 asymptomatic Wuchereria bancrofti microfilaraemic volunteers in a double blind hospital-based clinical study.     

Spatial and temporal expression of histone demethylase,Kdm2a,during murine molar development

The histone demethylase, lysine (K)-specific demethylase 2A (Kdm2a), is highly conserved and expressed ubiquitously. Kdm2a can regulate cell proliferation and osteo/dentinogenic, adipogenic and chondrogenic differentiation of mesenchymal stem cells (MSCs) derived from dental tissue. We used quantitative real-time RT-PCR analysis and immunohistochemistry to detect Kdm2a expression during development of the murine molar at embryonic days E12, E14, E16 and E17 and postnatal days P3 and P14. Immunohistochemistry results showed no positive staining of Kdm2a at E12. At E14, Kdm2a was expressed weakly in the inner enamel epithelium, stellate reticulum cells and dental sac. At E16, Kdm2a was expressed mainly in the inner and outer enamel epithelium, stratum intermedium and dental sac, but weaker staining was found in cervical loop and dental papilla cells adjacent to the basement membrane. At E17, the strongest Kdm2a staining was detected in the ameloblasts and stronger Kdm2a staining also was detected in the stratum intermedium, outer enamel epithelium and dental papilla cells compared to the expression at E16. Postnatally, we found that Kdm2a was localized in secretory and mature ameloblasts and odontoblasts, and dentin was unstained. Real-time RT-PCR showed that Kdm2a mRNA levels in murine germ cells increased from E12 to E14 and from E14 to E16; no significant change occurred at E16, E17 or P3, then the levels decreased at P14 compared to P3. Kdm2a expression may be closely related to cell proliferation, to ameloblast and odontoblast differentiation and to the secretion of extracellular enamel and dentin during murine tooth development.     

Cytokines in rats experimentally infected with Trypanosoma evansi

The aim of this study was to measure the levels of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukin 1 (IL-1) and interleukin 6 (IL-6) in the serum of rats experimentally infected with Trypanosoma evansi and to correlate these levels with hematological parameters. Initially, 48 rats (group T) were intraperitoneally inoculated with cryopreserved blood containing 1 × 10⁶ trypomastigotes per animal. Twenty-eight animals (group C) were used as negative controls and received 0.2 mL of saline by the same route. The experimental groups were formed according to the time after infection and the degree of parasitemia as follows: four control subgroups (C3, C5, C10 and C20) with seven non-inoculated animals each and four test subgroups (T3, T5, T10 and T20) with 10 animals each inoculated with T. evansi. The blood samples were collected by cardiac puncture at days 3 (C3, T3), 5 (C5, T5), 10 (C10, T10) and 20 (C20, T20) post-infection (PI) to perform the complete blood count and the determination of IFN-γ, TNF-α, IL-1 and IL-6 levels using an ELISA quantitative sandwich. Infected rats showed normocytic normochromic anemia during the experimental period. T. evansi infection in rats caused a serum increase (P < 0.01) of IFN-γ, TNF-α, IL-1 and IL-6 levels at days 3, 5, 10 and 20 PI compared to the controls. The multiple linear regressions showed a reduction of 24% in the hematocrit as a consequence of the increased IFN-γ, TNF-α and IL-1. Therefore, we conclude that the infection caused by T. evansi causes an increase in the pro-inflammatory cytokines. These results suggest a synergism among IL-1, TNF-α and IFN-γ contributing to the development of anemia. This increase is associated with the regulation of immune responses against the parasite.     

Efficient Identification of HIV Serodiscordant Couples by Existing HIV Testing Programs in South Brazil

Objective

To examine the feasibility of identifying HIV negative at risk individuals in HIV serodiscordant couples, during voluntary HIV testing in South Brazil.

Methods

We surveyed HIV testers at 4 public testing sites in Rio Grande do Sul. We obtained information on risk behaviors and sexual partnerships. HIV testing and testing for recent infection were performed; HIV prevalence and risk behaviors were assessed among subjects who reported having a steady partner who was HIV positive (serodiscordant group) and compared with the general testing population.

Results

Among 3100 patients, 490 (15.8%) reported being in a steady relationship with an HIV positive partner. New HIV infections were diagnosed in 23% of the serodiscordant group (vs. 13% in the general population, p = 0.01); among newly positive subjects, recent HIV infections were more frequent (23/86, 26.7%) among testers with positive partners than among the general testing group (52/334; 15.6%; p = 0.016). Less than half of the serodiscordant testers reported having used a condom during the last sexual intercourse with their HIV-positive partner. Participants with inconsistent condom use with steady partner were four times more likely to test positive for HIV compared to those who reported always using condoms with the steady partner (OR: 4.2; 95% CI: 2.3 to 7.5).

Conclusion

It is highly feasible to identify large numbers of HIV susceptible individuals who are in HIV serodiscordant relationships in South Brazil testing sites. Condom use within HIV serodiscordant couples is low in this setting, suggesting urgent need for biomedical prevention strategies to reduce HIV transmission.     

Thermographic evaluation of climatic conditions on lambs from different genetic groups

In production systems the characterization of genetic resources in relation to their capacity to respond to environmental conditions is necessary. The objective of this study was to evaluate the use of infrared thermography for separation of animals from different genetic groups and determine which phenotypic traits are important for climatic adaptation. A total of 126 suckling lambs from four different genetic groups (Santa Inês – SI, Bergamasca – B, Bergamasca X Santa Inês – BS, and Ile de France X Santa Inês – IL) were used. The animals were divided into two groups, one housed and another in an outside paddock. Thermograph photographs were taken at four-hour intervals over three full days. Temperatures of the nose, skull, neck, fore and rear flanks and rump were measured, as well as coat depth, the density and length of hairs, reflectance and color. The daily temperature range during the experimental period was more than 20°C, with animals experiencing heat (12 h to 15 h) and cold (24 h to 4 h) stress. The three main phenotypic traits that influenced genetic group separation were hair density, height of coat, and length of hairs. Thermograph temperatures were able to detect different responses of the genetic groups to the environment. Therefore, infrared thermography is a promising technique to evaluate the response of animals to the environment and to differentiate between genetic groups.     

Humoral and Cellular Immunity in Chromium Picolinate-Supplemented Lambs

The effects of oral supplementation of chromium picolinate (CrPic) on humoral and cellular immunity in sheep were investigated. Twenty-four male lambs divided into four treatments and received different dosages of CrPic: placebo (0), 0.250, 0.375, and 0.500 mg of chromium/animal/day during 84 days. The base ration was Panicum maximum cv Massai hay and concentrate. Blood samples were collected fortnightly for total and differential leukocyte counts. On days 28 and 56, the lambs were challenged with chicken ovalbumin I.M. Serum samples were collected on days 46 and 74 and subjected to an indirect enzyme-linked immunosorbent assay to measure IgG anti-ovalbumin. The cell-mediated immune response was determined by a delay-type hypersensitivity test using phytohemagglutinin. CrPic did not significantly affect humoral immunity in lambs but there was a negative effect on cellular immunity (P?<?0.05) as Cr supplementation increased. Therefore, the level of Cr supplementation for lambs must be better studied to address its effect on stressed animals or the possible toxic effects of Cr on the animal itself or its immune system.     

Mitochondrial ATP-sensitive K channels as redox signals to liver mitochondria in response to hypertriglyceridemia

We have recently demonstrated that hypertriglyceridemic (HTG) mice present both elevated body metabolic rates and mild mitochondrial uncoupling in the liver owing to stimulated activity of the ATP-sensitive potassium channel (mitoK_ATP). Because lipid excess normally leads to cell redox imbalance, we examined the hepatic oxidative status in this model. Cell redox imbalance was evidenced by increased total levels of carbonylated proteins, malondialdehydes, and GSSG/GSH ratios in HTG livers compared to wild type. In addition, the activities of the extramitochondrial enzymes NADPH oxidase and xanthine oxidase were elevated in HTG livers. In contrast, Mn-superoxide dismutase activity and content, a mitochondrial matrix marker, were significantly decreased in HTG livers. Isolated HTG liver mitochondria presented lower rates of H₂O₂ production, which were reversed by mitoK_ATP antagonists. In vivo antioxidant treatment with N-acetylcysteine decreased both mitoK_ATP activity and metabolic rates in HTG mice. These data indicate that high levels of triglycerides increase reactive oxygen generation by extramitochondrial enzymes that promote mitoK_ATP activation. The mild uncoupling mediated by mitoK_ATP increases metabolic rates and protects mitochondria against oxidative damage. Therefore, a biological role for mitoK_ATP as a redox sensor is shown here for the first time in an in vivo model of systemic and cellular lipid excess.     

The role of salivary nitrophorins in the ingestion of blood by the triatomine bug Rhodnius prolixus (Reduviidae: Triatominae)

To assist haematophagy, Rhodnius prolixus produces several bioactive molecules in its saliva which it injects into the host skin. The most abundant of these molecules are the nitrophorins (NPs). In this work, we reduced the expression of NP1-4 in the saliva of R. prolixus by RNAi and evaluated the subsequent feeding performance of the bugs using the cibarial pump electromyogram either on the dorsal skin or on the tail vein of the mice. NPs salivary mRNA was reduced by >99% in comparison to controls. Saliva from knockdown nymphs also presented 82% less haemproteins while the total protein was not reduced. Knockdown nymphs feeding on the skin had lower ingestion rates mainly due to the longer cumulative probing time and lower cibarial pump frequency. Another difference was that knockdown insects bit approximately 5 times more. No differences were observed between groups fed on the tail vein. When the feeding sites were compared, nymphs fed on the tail vein had higher effective ingestion rates. These findings endorse the importance of the NPs for the ability of bugs to complete the meal in a short total contact time with a low number of bites, decreasing the perception of the insect by the host.