We have produced monoclonal antibodies against Plasmodium yoelii merozoite surface protein 1 (MSP-1) and have assessed their ability to suppress blood stage parasitemia by passive immunization. Six immunoglobulin G antibodies were characterized in detail: three (B6, D3, and F5) were effective in suppressing a lethal blood stage challenge infection, two (B10 and G3) were partially effective, and one (B4) was ineffective. MSP-1 is the precursor to a complex of polypeptides on the merozoite surface; all of the antibodies bound to this precursor and to an ∼42-kDa fragment (MSP-142) that is derived from the C terminus of MSP-1. MSP-142 is further cleaved to an N-terminal ∼33-kDa polypeptide (MSP-133) and a C-terminal ∼19-kDa polypeptide (MSP-119) comprised of two epidermal growth factor (EGF)-like modules. D3 reacted with MSP-142 but not with either of the constituents MSP-133 and MSP-119, B4 recognized an epitope within the N terminus of MSP-133, and B6, B10, F5, and G3 bound to MSP-119. B10 and G3 bound to epitopes that required both C-terminal EGF-like modules for their formation, whereas B6 and F5 bound to epitopes in the first EGF-like module. These results indicate that at least three distinct epitopes on P. yoelii MSP-1 are recognized by antibodies that suppress parasitemia in vivo.

Schistosomiasis control seems to be different in countries were low parasitic burden and asymptomatic clinical patients are the features of majority of cases. Immunological methods must substitute the traditional coprologic techniques used for some decades in the Control Program. Circumoval Precipitin Test (COPT), intradermal test and ELISA with soluble egg antigen (SEA) are evaluated for using as tools for seroepidemiologic studies. COPT and ELISA were performed after treatment to known their utility when impact of chemotherapy must be assessed. One hundred sixty five persons were followed up 3, 6, 9 and 12 months after treatment. The mean sensitivity of COPT studied by age groups was 95.6% which is very important considering that 88.4% of the studied population excreted less than 100 eggs/gr of feces, while sensitivity of intradermal test was 58.2%. Children showed the highest reactivity to COPT. When treatment is effective, COPT reactivity progressively diminish until become negative one year later. In the non cure group, the COPT reactivity diminished but never below 20%. ELISA-SEA did not modify one year after treatment. Effort should be made to isolate fractions of eggs of Schistosoma mansoni whose antibodies disappear after treatment.

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Suture biomaterials are critical in wound repair by providing support to the healing of different tissues including vascular surgery, hemostasis, and plastic surgery. Important properties of a suture material include physical properties, handling characteristics, and biological response for successful performance. However, bacteria can bind to sutures and become a source of infection. For this reason, there is a need for new biomaterials for suture with antifouling properties. Here we report two types of cellulose fibers from coconut (Cocos nucifera) and sisal (Agave sisalana), which were purified with a chemical method, characterized, and tested in vitro and in vivo. According to SEM images, the cellulose fiber from coconut has a porous surface, and sisal has a uniform structure without internal spaces. It was found that the cellulose fiber from sisal has mechanical properties closer to silk fiber biomaterial using Ultimate Tensile Strength. When evaluating the cellulose fibers biodegradability, the cellulose from coconut showed a rapid weight loss compared to sisal. The antifouling test was negative, which demonstrated that neither possesses intrinsic microbicidal activity. Yet, a weak biofilm was formed on sisal cellulose fibers suggesting it possesses antifouling properties compared to cellulose from coconut. In vivo experiments using healthy mice demonstrated that the scarring and mechanical connection was like silk for both cellulose fibers. Overall, our results showed the potential use of cellulose fibers from vegetal for surgical sutures due to excellent mechanical properties, rapid degradation, and no bacterial adhesion.

Polyclonal immunoglobulin Y (IgY) antibodies were produced in chicken eggs against the purified R(II)-subunit of the cAMP-dependent protein kinase (PKA) from pig heart, which corresponds to the Sus scrofa R(II)α isoform. In order to evaluate whether Trypanosoma equiperdum possessed PKA R-like proteins, parasites from the Venezuelan TeAp-N/D1 strain were examined using the generated anti-R(II) IgY antibodies. Western blot experiments revealed a 57-kDa polypeptide band that was distinctively recognized by these antibodies. Likewise, polyclonal antibodies raised in mice ascites against the recombinant T. equiperdum PKA R-like protein recognized the PKA R(II)-subunit purified from porcine heart and the recombinant human PKA R(I)β-subunit by immunoblotting. However, a partially purified fraction of the parasite PKA R-like protein was not capable of binding cAMP, implying that this protein is not a direct downstream cAMP effector in T. equiperdum. Although the function of the S. scrofa PKA R(II)α and the T. equiperdum PKA R-like protein appear to be different, their cross-reactivity together with results obtained by bioinformatics techniques corroborated the high level of homology exhibited by both proteins. Moreover, its presence in other trypanosomatids suggests an important cellular role of PKA R-like proteins in parasite physiology.