1,8-cineole and castor oil in sodium lauryl ether sulphate disrupt reproduction and ovarian tissue of Rhipicephalus (Boophilus) microplus.

Essential and fixed oils have been researched as alternatives to chemical acaricides. The activity of volatile compounds from essential oils (1,8-cineole, citral and eugenol) at 1.0% (w/v) and fixed oil (castor oil) at 0.3% (w/v) dissolved in 2.0% (v/v) dimethyl sulfoxide (DMSO) + 0.2% (w/v) Tween 80® was assessed against Rhipicephalus microplus using immersion tests. 1,8-cineole (29.0%) and castor oil (30.2%) had the highest reproductive inhibition rate. A second experiment was performed to verify the effect of the 1,8-cineole (10.0% w/v) and, or castor oil (0.3% w/v) on tick reproduction using different solubilizing agents. The highest reproductive inhibition was observed for the combination of 1,8-cineole/castor oil (94.1%) and 1,8-cineole in 2.0% (w/v) sodium lauryl ether sulphate (SLES) (92.8%). A third experiment showed morphological changes in R. microplus oocytes at different stages of development, as well as in pedicel cells. The most intense effects were observed when ticks were immersed in the formulation containing 1,8-cineole (10.0% w/v) and castor oil (0.3% w/v) dissolved in 2% (w/v) SLES. These findings highlight the potential of this formulation as an alternative for managing cattle ticks as their cytotoxic effects can reduce R. microplus reproductive success.

Synthesis and herbicidal activity of 2alpha, 4alpha-dimethyl-8-oxabicyclo[3.2.1]oct-6-en-3-one derivatives.

The catalytic oxidation of 2alpha,4alpha-dimethyl-8-oxabicyclo[3.2. 1]oct-6-en-3-one with osmium tetraoxide and excess hydrogen peroxide resulted in the formation of 2alpha,4alpha-dimethyl-6, 7-exo-isopropylidenedioxy-8-oxabicyclo[3.2.1]octan-3-one (2), with 91% yield. Addition of aryllithium reagents to this compound resulted in the formation of the aromatic alcohols (6a-h) with 48-76% yield. These alcohols were treated with thionyl chloride in pyridine, and the corresponding alkenes (7a-h) were obtained with 46-80% yield. The effect of compounds 6a-h and 7a-h on the root growth of Sorghum bicolor was evaluated at a concentration of 6.6 microg g(-)(1). The alcohols 6a-h caused an inhibitory effect (8-100%) on the S. bicolor radicle growth. The three most active compounds were 6e (aryl = p-methylphenyl), 6g (aryl = p-chlorophenyl), and 6h (aryl = p-fluorophenyl) and caused 100% inhibition. The effect of alkenes 7a-h was less pronounced and varied from 15% to 46% inhibition. Another experiment was carried out in a greenhouse to evaluate the effect of alcohols 6e, 6g, and 6h, at a 6.6 microg g(-)(1) dose, against Cucumis sativus, S. bicolor and the weeds Bidens pilosa, Desmodiumtortuosum, and Pennisetum setosum. All three compounds showed an inhibitory effect on the development of the aerial parts (26-73%) and roots (13-79%) of the weeds and crops.

Mycobacterium leprae DNA in peripheral blood may indicate a bacilli migration route and high-risk for leprosy onset.

Leprosy epidemiological studies have been restricted to Mycobacterium leprae DNA detection in nasal and oral mucosa samples with scarce literature on peripheral blood. We present the largest study applying quantitative real-time PCR (qPCR) for the detection of M. leprae DNA in peripheral blood samples of 200 untreated leprosy patients and 826 household contacts, with results associated with clinical and laboratory parameters. To detect M. leprae DNA a TaqMan qPCR assay targeting the M. leprae ML0024 genomic region was performed. The ML0024 qPCR in blood samples detected the presence of bacillus DNA in 22.0% (44/200) of the leprosy patients: 23.2% (16/69) in paucibacillary (PB), and 21.4% (28/131) in multibacillary (MB) patients. Overall positivity among contacts was 1.2% (10/826), with similar percentages regardless of whether the index case was PB or MB. After a follow-up period of 7 years, 26 contacts have developed leprosy. Comparing the results of healthy contacts with those that become ill, ML0024 qPCR positivity at the time of diagnosis of their index case represented an impressive 14.78-fold greater risk for leprosy onset (95% CI 3.6-60.8; p <0.0001). In brief, contacts with positive PCR in blood at diagnosis of index cases are at higher risk of later leprosy onset and this marker might be combined with other prognostic markers for management of contacts, which requires further studies.

Oral mucosa as a source of Mycobacterium leprae infection and transmission, and implications of bacterial DNA detection and the immunological status.

Leprosy is an important health problem in Brazil despite extensive use of multidrug therapy. The nasal mucosa is the preferential site of entry and exit of Mycobacterium leprae, and although lesions have been found in the oral mucosa, its potential involvement in the transmission of leprosy bacilli has never been investigated. We investigated the presence of the M. leprae DNA in buccal swabs of leprosy patients (334) and household contacts (1288) through polymerase chain reaction (PCR), and correlated this with clinical and laboratorial evaluations. The overall positivity for patients and contacts was 18.26% and 6.83%, respectively. Subclinical infection among contacts was considered when PCR and anti-PGL-1 ELISA presented positive results. This study provides evidence that the oral mucosa may be a secondary site of M. leprae transmission and infection, and contacts with bacillary DNA may be actively involved in transmission. We have also shown that bacilli DNA is more frequently found in the oral mucosa of PB patients. Our findings have great epidemiological relevance and indicate an additional strategy for leprosy control programmes and dental clinics.

Efeito moluscicida do óleo essencial de Cymbopogon winterianus Jowitt (Poaceae) sobre Lymnaea columella (Say, 1817) e Biomphalaria tenagophila (D'Orbigny, 1835) / Molluscicidal effect of essential oil of Cymbopogon winterianus Jowitt (Poaceae) on Lymnaea columella (Say, 1817) and Biomphalaria tenagophila (D'Orbigny, 1835)

RESUMO O uso das substâncias moluscicidas convencionais no controle de planorbídeos vetores constitui-se uma importante ferramenta no combate da fasciolose hepática e esquistossomose. Sendo, portanto, de extrema relevância para a pecuária e para os serviços de Vigilância Epidemiológica. Por outro lado, a seleção de caramujos resistentes a tais substâncias e sua baixa seletividade estimulam a busca por novas substâncias. Neste sentido, o presente trabalho foi desenvolvido para avaliar o efeito do óleo essencial de Cymbopogon winterianusJowitt sobre Lymnaea columella e Biomphalaria tenagophila, hospedeiros intermediários de Fasciola hepatica e esquistossomose mansônica, respectivamente. O óleo essencial foi extraído a partir de folhas frescas utilizando o sistema Clevenger. A análise qualitativa foi realizada por meio de cromatografia gasosa acoplada a espectrometria de massas (CG/EM) e a quantificação dos constituintes presentes no óleo foi determinada por cromatografia gasosa acoplada ao detector de ionização de chama (CG/DIC). O efeito moluscicida foi avaliado utilizando seis moluscos de cada espécie e o óleo essencial de C. winterianus nas concentrações finais de 10, 20, 30, 40, 60, 80 e 100 ppm. A análise por cromatografia gasosa do óleo essencial possibilitou a identificação dos componentes majoritários geraniol (28,62%), citronelal (23,62%) e citronelol (17,10%). Os valores de DL100 e DL50para os moluscos das espécies L. columella e B. tenagophila foram, respectivamente, 60 e 40 ppm; 80 ppm e 60 ppm. O óleo de Cymbopogon winterianus demonstrou-se uma alternativa promissora para o controle dos moluscos, sendo a espécie L. columella mais sensível ao mesmo.

ABSTRACT Conventional molluscicides have been employed to control of planorbids vectors and are an important tool in order to control the hepatic fascioliasis and schistosomiasis. Thus, these substances have been showinggreat relevance for both Veterinary and Livestock Services as well as for Epidemiology and Disease Surveillance. On the other hand, the process of drug pressure for the selection of resistant snails to such components and their low selectivity have stimulated the search for new substances. Since researches on new drugs are the starting point to assist on themolluscs control, this work was developed in order to evaluate the effect of Cymbopogon winterianus Jowitt essential oil on L. columella and B. tenagophila, intermediate hosts of Fasciola hepatica and Schistosoma mansoni, respectively. The essential oil was obtained from fresh leaves by hydrodistillation using a Clevenger apparatus. A qualitative analysis was performed by gas chromatography together with a mass spectrometry one (GC/MS) and the chemical constituent content was determined by gas chromatography with a flame ionization detector (GC/FID). The molluscicidal effect was evaluated through the use of six snails of each species and C. winterianus essential oil at 10, 20, 30, 40, 60, 80 and 100 ppm. The result of the gas chromatographic analysis for the essential oil showed geraniol (28.62%), citronellal (23.62%) and citronellol (17.10%) as the major chemical components . The DL100 and DL50 values for L. columella and B. tenagophila species were, respectively, 60 and 40 ppm; 80 ppm and 60 ppm. L. columella had demonstrated more sensitivity to this essential oil than theB. tenagophila species. The C. winterianus essential oil proved to be a promising alternative for the control of these molluscs being the L. columella species the most sensitive of them.

Egg-hatching inhibition in mice immunized with recombinant Schistosoma bovis 28 kDa glutathione S-transferase.

The capacity of a recombinant glutathione S-transferase from Schistosoma bovis (rSb 28GST) to protect BALB/c mice against homologous and heterologous infections with, respectively, S. bovis or Schistosoma mansoni has been studied. Two injections of the rSb 28GST and an intravenous boost resulted in a marked specific IgG response on the day of experimental challenge with S. bovis or S. mansoni cercariae. Immunization of BALB/c mice led to a reduction in egg maturation and egg viability after infection with S. bovis or S. mansoni. Adult worm recoveries after an S. bovis challenge infection and tissue egg densities (intestine and liver) in S. mansoni challenge infection were also reduced in the immunized groups, but these differences were not statistically significant. No association between in vitro inhibition of GST enzymatic activity induced by immunized mouse sera and worm burden reduction was recorded. The analysis of the immune response, on the day of perfusion, showed the production of immunoglobulin (Ig)G1, IgG2a and IgG2b specific antibodies and the production of interleukin (IL)-4 and IL-5 by spleen cells after rSb 28GST stimulation. These data suggest that rSb 28GST immunization induces a moderate effect upon egg maturation and egg hatching, suggesting the involvement of similar mechanisms of action and common, but not exclusive, targets during S. bovis and S. mansoni infections. As a consequence, immunization with rSb 28GST may prove useful in affecting the pathology and transmission of African schistosomes.

Definition and mapping of epitopes recognized by specific monoclonal antibodies to Schistosoma bovis 28 kDa glutathione S-transferase: relation with anti-egg viability immunity.

Monoclonal antibodies to the 28kDa glutathione S-transferase of Schistosoma bovis have been constructed in mice and used to characterize the epitope(s) potentially implied in the induction of anti-fecundity and anti-egg viability immune responses. Among the MoAbs produced three were particularly studied: Sb4-50 (IgG2a) and Sb4-56 (IgG1) which inhibited Sb28GST activity and Sb4-10 (IgG1) which did not. The use of overlapping peptides covering the entire amino acid sequence of Sb28GST, allowed us to define the linear epitopes recognized by these anti-Sb28GST MoAbs. Amino acid residues 202-211 were recognized by both MoAbs Sb4-50 and Sb4-56 and MoAb Sb4-10 recognized amino acid residues 58-67. Their capacity to inhibit GST activity suggested binding to the active site or to neighbouring regions, which include the C-terminal domain (a.a. 190-211) of the protein. When passively transferred into BALB/c mice MoAbs induced a significant reduction in egg hatching and an increase in immature eggs. Effects on worm burdens were, however, variable and no clear-cut association between the inhibition of enzyme activity and anti-fecundity or anti-viability activities was recorded. Our data indicate that beside the anti-fecundity and anti-viability immunity related to the impairment of GST activity, immune response to epitopes located in other regions of the molecule also contribute to the reduction of egg viability.