Epistylis smalli (Ciliophora: Peritrichia) a new peritrich from Guaiba Lake, Southern Brazil.

Epistylis smalli n. sp., a freshwater colonial peritrich, was collected in Guaíba Lake, Southern Brazil. Its morphology was investigated using in vivo observations and protargol stained specimens. E. smalli possess an elongate zooid that measures in vivo, on average, 173 µm in length and 50 µm in width. A C-shaped macronucleus that surrounds the infundibulum and a single contractile vacuole could be easily observed in the living cell. The oral infraciliature observed in silver-stained specimens was typical of peritrich ciliates, with three infundibular polykinetids bearing three rows of kinetosomes. A detailed description of the live and stained zooids is given.

Antibody responses induced by Leish-Tec®, an A2-based vaccine for visceral leishmaniasis, in a heterogeneous canine population.

Zoonotic visceral leishmaniasis (VL) is a widespread disease, and dogs are the main reservoirs for human parasite transmission. Hence, development of an effective vaccine that prevents disease and reduces the transmission of VL is required. As euthanasia of seropositive dogs is recommended in Brazil for VL epidemiological control, to include anti-VL canine vaccines as a mass control measure it is necessary to characterize the humoral responses induced by vaccination and if they interfere with the reactivity of vaccinated dogs in serological diagnostic tests. Leish-Tec(®) is an amastigote-specific A2 recombinant protein vaccine against canine visceral leishmaniasis (CVL) that is commercially available in Brazil. Here, we tested the immunogenicity of Leish-Tec(®) in a heterogeneous dog population by measuring A2-specific antibody responses. Healthy dogs (n=140) of various breeds were allocated to two groups: one group received Leish-Tec(®) (n=70), and the other group received a placebo (n=70). Anti-A2 or anti-Leishmania promastigote antigen (LPA) antibody levels were measured by ELISA in serum samples collected before and after vaccination. An immunochromatographic test (DPP) based on the recombinant K28 antigen was also used for serodiagnosis of CVL. Vaccinated animals, except one, remained seronegative for anti-LPA total IgG and anti-K28 antibodies. Conversely, seropositivity for anti-A2 total IgG antibodies was found in 98% of animals after vaccination. This value decreased to 81.13% at 6 months before rising again (98%), after the vaccination boost. Anti-A2 IgG2 and IgG1 titers were also increased in vaccinated animals relative to control animals. These data indicate that Leish-Tec(®) is immunogenic for dogs of different genetic backgrounds and that humoral responses induced by vaccination can be detected by A2-ELISA, but do not interfere with the LPA-ELISA and DPP diagnostic tests for CVL.

Improved canine and human visceral leishmaniasis immunodiagnosis using combinations of synthetic peptides in enzyme-linked immunosorbent assay.

BACKGROUND: Zoonotic visceral leishmaniasis (VL) is a severe infectious disease caused by protozoan parasites of the genus Leishmania and the domestic dogs are the main urban parasite reservoir hosts. In Brazil, indirect fluorescence antibody tests (IFAT) and indirect enzyme linked immunosorbent assay (ELISA) using promastigote extracts are widely used in epidemiological surveys. However, their sensitivity and specificity have often been compromised by the use of complex mixtures of antigens, which reduces their accuracy allowing the maintenance of infected animals that favors transmission to humans. In this context, the use of combinations of defined peptides appears favorable. Therefore, they were tested by combinations of five peptides derived from the previously described Leishmania diagnostic antigens A2, NH, LACK and K39. METHODOLOGY/PRINCIPAL FINDINGS: Combinations of peptides derived A2, NH, LACK and K39 antigens were used in ELISA with sera from 44 human patients and 106 dogs. Improved sensitivities and specificities, close to 100%, were obtained for both sera of patients and dogs. Moreover, high sensitivity and specificity were observed even for canine sera presenting low IFAT anti-Leishmania antibody titers or from asymptomatic animals. CONCLUSIONS/SIGNIFICANCE: The use of combinations of B cell predicted synthetic peptides derived from antigens A2, NH, LACK and K39 may provide an alternative for improved sensitivities and specificities for immunodiagnostic assays of VL.

Interaction between oral estrogen plus progestogen therapy and ABO blood groups on coagulation activation in postmenopausal women.

OBJECTIVE: The aim of this study was to investigate the effect of postmenopausal hormone therapy on coagulation and whether this effect differs according to ABO blood groups. METHODS: This was a prospective observational study to evaluate factor VIII (FVIII) activity, factor von Willebrand (vWF), and D-dimer (D-Di) levels and ABO blood groups in 61 postmenopausal women using oral estrogen plus progestogen therapy (EPT; 2 mg estradiol + 1 mg norethisterone acetate) for 3 months and in 101 women not using EPT. After 3 months, all eligible women who had completed the treatment scheme proposed for the EPT group or those who opted to participate but had not undergone EPT had a blood sample collected for analysis. RESULTS: Significant differences were observed in FVIII activity and vWF levels in the control group between those carrying group O and non-group O blood. For EPT users, significant differences were observed for FVIII activity, vWF, and D-Di levels. After a multivariate regression analysis, FVIII activity and ABO blood groups were independently associated with vWF levels, whereas interaction between ABO blood groups and EPT were independently associated with FVIII activity. Besides diabetes, the ABO × EPT interaction was also noted to be independently associated with D-Di levels. CONCLUSIONS: These findings suggest an interactive effect between oral EPT and non-O blood groups, contributing to the mechanism by which estrogen triggers the hypercoagulability state and increased risk for venous thrombosis in women undergoing oral EPT.

Plasminogen activator inhibitor-1 4G/5G promoter polymorphism and PAI-1 plasma levels in young patients with ischemic stroke.

The 4G/5G polymorphism in the plasminogen activator inhibitor-1 (PAI-1) gene, has been associated with arterial disease. In this study, we investigated the association of IS in young patients with CRP and PAI-1 levels and frequency of insertion-deletion polymorphism of PAI-1 gene. The plasma levels of PAI-1 and CRP and the frequency of 4G/5G polymorphism were analyzed in 127 Brazilian young patients that presented IS and in 201 healthy and unrelated control subjects. The levels of CRP (P < 0.001) and PAI-1 (P < 0.001) were significantly higher in patients when compared with control group. Only PAI-1 plasma levels were independently associated with risk of IS (OR 3.40; 95% CI 1.49-7.74; P = 0.001) after adjustments for lifestyles covariates. The 4G/4G genotype was significantly more frequent among control subjects as compared to patients (OR 0.41; 95% CI 0.24-0.68; P < 0.001). Although increased PAI-1 plasma levels are associated with development of IS in Brazilian young patients, they are not influenced by the 4G/5G PAI-1 polymorphism.