Avaliação e comparação entre métodos de mensuração de pressão arterial sistólica em gatos hígidos conscientes / Evaluation and comparison between methods of measurement of systolic blood pressure in healthy conscious cats

Após validação de dois diferentes métodos de mensuração de pressão arterial sistólica (PAS) não invasivos ou indiretos (oscilométrico e Doppler vascular) com o invasivo ou direto (cateterização arterial - padrão ouro) em 12 gatos hígidos anestesiados de mesma faixa etária, os métodos não invasivos foram avaliados e comparados em 24 gatos hígidos e conscientes, divididos em quatro grupos de idade. Em cada animal, procedeu-se à mensuração da pressão pelos métodos Doppler e oscilométrico. O método oscilométrico foi o primeiro a ser realizado, e, logo em seguida, o método Doppler. Os valores considerados foram obtidos das médias de sete medidas consecutivas para cada método, com intervalo de 30 segundos entre elas. A primeira medida e as medidas discrepantes (variação ˃ 20% PAS), obtidas com sinais óbvios de estresse e/ou com movimentação do animal, foram descartadas. Os métodos de mensuração oscilométrico e Doppler, embora tenham apresentado médias estatisticamente diferentes em todos os grupos, quando comparados em cada grupo, apresentaram uma correlação significativa, alta e positiva. Ou seja, sempre que for obtido um valor elevado por um método, o mesmo fato ocorrerá com o outro método e vice-versa. Clinicamente, a diferença observada não é relevante, uma vez que a diferença média dos valores obtida pelos dois métodos, em cada grupo, foi menor que 1,1%.(AU)

After two different validation systolic blood pressure measurement methods (PAS), not invasive or indirect (oscillometric and doppler vascular) with invasive or direct (arterial catheterization - Gold Standard) in 12 anesthetized healthy cats of the same age group, not invasive methods were evaluated and compared in 24 healthy conscious cats, divided into four age groups. In each animal, we proceeded to measure the pressure by Doppler and oscillometric methods. The oscillometric method was the first to be performed, and, shortly thereafter, the doppler method. The values considered were obtained from averages from seven consecutive measurements for each method with an interval of thirty seconds between them. The first measurement and disparate measurements (range ˃ 20% PAS) obtained with obvious signs of stress and / or animal movement were discarded. Methods of oscillometric and doppler measurement, although statistically different averages were shown in all groups when compared, each group showed a significant high positive correlation, meaning that when a high value is obtained by a method, the same occurs with the other method, and vice versa. Clinically, the observed difference is not relevant since the mean difference values obtained by the two methods, in each group was lower than 1.1%.(AU)

Cross-protective efficacy from a immunogen firstly identified in Leishmania infantum against tegumentary leishmaniasis.

Experimental vaccine candidates have been evaluated to prevent leishmaniasis, but no commercial vaccine has been proved to be effective against more than one parasite species. LiHyT is a Leishmania-specific protein that was firstly identified as protective against Leishmania infantum. In this study, LiHyT was evaluated as a vaccine to against two Leishmania species causing tegumentary leishmaniasis (TL): Leishmania major and Leishmania braziliensis. BALB/c mice were immunized with rLiHyT plus saponin and lately challenged with promastigotes of the two parasite species. The immune response generated was evaluated before and 10 weeks after infection, as well as the parasite burden at this time after infection. The vaccination induced a Th1 response, which was characterized by the production of IFN-γ, IL-12 and GM-CSF, as well as by high levels of IgG2a antibodies, after in vitro stimulation using both the protein and parasite extracts. After challenge, vaccinated mice showed significant reductions in their infected footpads, as well as in the parasite burden in the tissue and organs evaluated, when compared to the control groups. The anti-Leishmania Th1 response was maintained after infection, being the IFN-γ production based mainly on CD4(+) T cells. We described one conserved Leishmania-specific protein that could compose a pan-Leishmania vaccine.

Prophylactic properties of a Leishmania-specific hypothetical protein in a murine model of visceral leishmaniasis.

In this work, the effect of vaccination of a newly described Leishmania infantum antigenic protein has been studied in BALB/c mice infected with this parasite species. The LiHyD protein was characterized after a proteomic screening performed with the sera from dogs suffering visceral leishmaniasis (VL). Its recombinant version was expressed, purified and administered to BALB/c mice in combination with saponin. As a result of vaccination and 10 weeks after challenge using an infective dose of L. infantum stationary promastigotes, vaccinated mice showed lower parasite burdens in different organs (liver, spleen, bone marrow and footpads' draining lymph nodes) than mice inoculated with the adjuvant alone or the vaccine diluent. Protected mice showed anti-Leishmania IgG2a antibodies and a predominant IL-12-driven IFN-γ production (mainly produced by CD4(+) T cells) against parasite proteins, whereas unprotected controls showed anti-Leishmania IgG1 antibodies and parasite-mediated IL-4 and IL-10 responses. Vaccinated mice showed an anti-LiHyD IgG2a humoral response, and their spleen cells were able to secrete LiHyD-specific IFN-γ, IL-12 and GM-CSF cytokines before and after infection. The protection was correlated with the Leishmania-specific production on nitric oxide. Altogether, the results indicate that the new LiHyD protein could be considered in vaccine formulations against VL.

Avaliação e comparação entre métodos de mensuração de pressão arterial sistólica em gatos hígidos anestesiados / Evaluation and comparison between methods of measurement of systolic blood pressure in healthy anesthetized cats

Foram avaliados e comparados, para fins de validação, dois diferentes métodos de mensuração de pressão arterial sistólica (PAS), não invasivos ou indiretos (oscilométrico e Doppler vascular) com o invasivo ou direto (cateterização arterial - padrão ouro), em 12 gatos hígidos anestesiados de idade variando entre sete meses e dois anos. Em cada animal, procedeu-se à mensuração simultânea da pressão não invasiva e da invasiva. O método oscilométrico foi comparado, por meio de sete medidas consecutivas, com intervalo de 30 segundos entre elas, com o método invasivo, e, logo em seguida, o método Doppler foi comparado ao método invasivo da mesma maneira. Concluiu-se que o método oscilométrico é estatisticamente igual ao método invasivo, enquanto o Doppler difere de ambos. Entretanto, pela forte correlação positiva entre os métodos Doppler e invasivo, foi possível criar um fator de correção (equação de regressão linear) para se determinar o valor da pressão invasiva, a partir do valor obtido pelo método Doppler. Para obtenção de valores mais fidedignos, recomenda-se a utilização desse fator de correção quando o método Doppler for utilizado para mensuração de PAS em gatos anestesiados.

For validation purposes, two different methods of measurement of systolic blood pressure (SBP), noninvasive or indirect (oscillometric and vascular doppler), direct or invasive (arterial catheterization - the gold standard) were evaluated and compared in 12 healthy anesthetized cats, varying between seven months to two years old. In each animal, we proceeded to the simultaneous noninvasive and invasive measurement of pressure. The oscillometric method was compared by means of seven consecutive measurements with an interval of 30 seconds between them, with the invasive method, and soon after, the doppler method was compared to the invasive method in the same way. It was concluded that the oscillometric method is statistically equal to the invasive method, whereas doppler differs from both. However, due to the strong positive correlation between doppler and invasive methods, it was possible to create a correction factor (linear regression) to determine the value of invasive pressure from the value obtained by the doppler method. To obtain more reliable figures, it is recommended to use this correction factor when the doppler method is used to measure SBP in anesthetized cats.

Immunodiagnosis of human neurocysticercosis using a synthetic peptide selected by phage-display.

The usefulness of a synthetic peptide in the serodiagnosis of Taenia solium human neurocysticercosis (NC) has been evaluated. Phage-displayed peptides were screened with human antibodies to scolex protein antigen from cysticercus cellulosae (SPACc). One clone was found to interact specifically with anti-SPACc IgGs. The corresponding synthetic peptide was found to be recognized in ELISA by NC patient's sera. The study was carried out with sera from 28 confirmed NC patients, 13 control sera and 73 sera from patients suffering from other infectious diseases. A 93% sensibility and a 94.3% specificity was achieved. Figures of 89% and 31.4% of sensibility and specificity were obtained in a SPACc-based ELISA. Immunoblotting of SPACc with anti-peptide antibodies revealed a single band of approximately 45 kDa in 1D and four 45 kDa isoforms in 2D-gel electrophoresis. A strong and specific immunostaining in the fibers beneath the suckers, at the base of the rostellum, and in the tissue surrounding the scolex of cysticerci was observed by immunomicroscopy. Our results show that a peptide-based immunodiagnostic of neurocisticercosis can be envisioned.

Molecular characterization of protective antibodies raised in mice by Tityus serrulatus scorpion venom toxins conjugated to bovine serum albumin.

The possibility of raising a humoral immune response capable of inducing in vivo protection against the lethal effects of Tityus serrulatus (Ts) scorpion venom was evaluated in the mouse model. An immunogen was prepared that consists of a toxic fraction (TstFG(50)) of the Tityus venom (this G(50) chromatography fraction represents most of the toxicity of the crude venom) conjugated to bovine serum albumin (BSA) with glutaraldehyde. TstFG(50) coupled to BSA yielded a thoroughly detoxified immunogen. BALB/c and C57BL/10 mice were immunized with this preparation and all developed an antibody response. In vivo protection assays one week after the last immunization showed that vaccinated mice could resist the challenge by twice the LD(50) of the TstFG(50), a dose which killed all control non-immune mice. The protective effect persisted nine weeks after the end of the immunization protocol. To characterize epitopes of protective antibodies we used the Spot method of multiple peptide synthesis to prepare sets of immobilized 15 mer overlapping peptides, covering the complete amino acid sequences of the main Tityus toxins, TsII and TsVII (both beta-type toxins) and TsIV, an alpha-type toxin that is the major lethal component of the venom. Antibody binding to peptides, revealed one major antigenic region in the C-terminal part of the three toxins and another region in the helical part of TsII and TsIV toxins. It is likely that these epitopes correspond to neutralizing epitopes since they correspond to regions of the toxins that are known to be involved in the active site of the toxins.

Efficacy of oxamniquine and praziquantel in the treatment of Schistosoma mansoni infection: a controlled trial.

OBJECTIVE: To evaluate the therapeutic efficacy of oxamniquine and praziquantel, the two most clinically important schistosomicide drugs, and to compare the accuracy of faecal examination with the accuracy of oogram in testing for Schistosoma mansoni infection. METHODS: In a triple-masked and randomized controlled trial, 106 patients infected with S. mansoni were randomly allocated to one of three statistically homogeneous groups. One group was given 60 mg/kg praziquantel per day for three consecutive days, another was given two daily doses of 10 mg/kg oxamniquine, and the placebo group received starch. Faecal examinations (days 15, 30, 60, 90, 120, 150, and 180 after treatment) and biopsy of rectal mucosa by quantitative oogram (days 30, 60, 120, and 180) were used for the initial diagnosis and for evaluating the degree of cure. The chi2 test and the Kruskal-Wallis test were used to compare variables in the three groups. Survival analysis (Kaplan-Meier) and the log-rank test were used to evaluate the efficacy of the treatments. FINDINGS: The sensitivity of stool examinations ranged from 88.9% to 94.4% when patients presented with >5000 S. mansoni eggs per gram of tissue (oogram); when the number of eggs dropped to <1000 eggs per gram, sensitivity was reduced (range, 22.7-34.0%). When cure was evaluated by stool examination, oxamniquine and praziquantel had cure rates of 90.3% and 100%, respectively. However, when the oogram was used as an indicator of sensitivity, the oxamniquine cure rate dropped dramatically (to 42.4%), whereas the rate for praziquantel remained high, at 96.1%. CONCLUSIONS: Praziquantel was significantly more effective than oxamniquine in treating S. mansoni infection. The oogram was markedly more sensitive than stool examinations in detecting S. mansoni eggs and should be recommended for use in clinical trials with schistosomicides.

Schistosoma mansoni: identification of a 46KDa antigen of the schistosomular surface by monoclonal antibody

Um anticorpo monoclonal da subclasse IgG2a, designado C6G9, foi obtido pela imunizacao de camundongos BALB/c com antigenos de ovo de Schistosoma mansoni. Esse anticorpo monoclonal possibilitou a identificacao de um antigeno de peso molecular aproximado de 46 quilodaltons (KDa), cuja expressao foi avaliada atraves da reacao de imunofluorescencia indireta. O referido antigeno persistiu no tegumento do esquistossomulo em desenvolvimento pelo menos ate 96 horas pos-transformacao. O anticorpo monoclonal reagiu tambem com a superficie de cercarias, mas nao com a de vermes adultos. O C6G9, em presenca de complemento, foi tambem capaz de mediar niveis significativos de citoxicidade para esquistossomulos recem-transformados.

Entamoeba histolytica: antigenic characterization of axenic strains from Brazil

Trofozoitos obtidos de cultura de Entamoeba histolytica isoladas e axenizadas no Brasil (ICB-CSP, ICB-462 e ICB-32) foram utilizados para a producao de soros imunes em coelhos e para a caracterizacao de antigenos atraves dos seus perfis eletroforetico e glicoproteico, em paralelo com uma cepa padrao isolada e axenizada nos Estados Unidos (HK-9). Obtiveram-se soros hiperimunes, reativos frente aos antigenos homologos e heterologos. As quatro cepas em estudo apresentaram perfis eletroforetico e glicoproteico complexos e semelhantes, compostos por polipeptideos com pesos moleculares variando de 200 kDa a menos de 29 kDa. Nao se detectaram diferencas significativas entre as cepas patogenicas e nao patogenicas.

ELISA detection of specific circulating antibodies against Schistosoma mansoni in mice after treatment with oxamniquine

Mice infected with 80 cercariae of Schistosoma mansoni treated with a single oral dose of oxamnique (400 mg/kg) 65 days after infection. Groups of 8-12 animals were sacrificed approximately 2 weeks after treatment and then at montly intervals. The sera obtained were evaluated for S. mansoni antibodies by enzyme-linked immunosorbeent assay (ELISA) at 1:200 dilution. Worms could not be recovered on days 14, 28, 58, 90, 119, 154 and 180 after treatment, indicating the efficacy of the chemotherapy. When performed with different antigens obtained from several stages in the life cycle of S. mansoni, i.e., soluble egg antigen, adult worm tegument, cercaria antigen, schistosomule tegument and adult worm (10 *g antigen/ml), the ELISA showed a decrease in specific antibody levels as a function of time after treatment starting on day 58, reaching levels close to control (noninfected untreated) in most animals 120 days after treatment. Purified antigens from the adult worm and the schistosomule tegument appear to be promising for use in clinical studies evaluating schistosomiasis after drug treatment

Generation of protective immune sera by Crotalus durissus terrificus venom detoxified by controlled iodination

1. Whole soluble venom from the snake Crotalus durissus terrificus was detoxified by controlled iodination. Doses equivalent to 100 LD50 of the native venom were administerd to mice, without signs of intoxication. 2. The non-toxic iodinated derivative were able to stimulate antibodies in rabbits and horses within a short period (6 months) of inmunization. Horse antisera attained titers of 0.5 to 0.9 mg/ml for protection aginst native venom. 3. Horse antisera obrained in horses from native and iodinated venom were run against both native and iodinated venoms, as antigens, in gel immunodiffusion. The precipitation lines showed total identity of the types of sera