Hematologic variables of the Arrau turtle (Podocnemis expansa) under the effects of different anticoagulants and cytologic stains.

BACKGROUND: The hematology of turtles of the Amazon, such as the Arrau turtle (Podocnemis expansa), has not been well described in the literature. Referencing how to collect and analyze blood samples is fundamental for the medical practice of these exotic animals. OBJECTIVES: The aim of this study was to evaluate the hematologic parameters of Arrau turtles of the Amazon to determine the best anticoagulant (EDTA, citrate, or sodium heparin) and cytologic stain (Giemsa, Quick Panoptic, or Rosenfeld) for use with this species. METHODS: Blood samples from eight turtles were collected. Three blood smears were made using blood without anticoagulant, and the rest of the sample was distributed in three tubes, containing EDTA, citrate, and sodium heparin, for erythrogram and leukogram analyses. RESULTS: All blood samples anticoagulated with EDTA showed marked hemolysis. Blood collected with citrate showed minimal hemolysis, and blood collected with sodium heparin did not have any hemolysis. Some analyses were not performed on blood containing EDTA because of the intense hemolysis. The erythrocyte variables were obtained and showed better results for blood samples in heparin. Blood smears without anticoagulant were appropriate for differential leukocyte counts with the three stain types, while blood with any of the anticoagulants made it difficult to differentiate leukocytes. CONCLUSIONS: Sodium heparin showed the best results and should be the anticoagulant of choice for hematologic studies in P expansa. All cytologic stains were efficient, allowing adequate identification of distinct cell groups. Leukocyte differentiation was assured and had better contrast using blood smears made from blood without an anticoagulant.

Haematological and immunophenotypic evaluation of peripheral blood cells of cattle naturally infected with bovine papillomavirus.

Papillomaviruses are among the most widespread animal viruses, with many hosts harbouring multiple virus types. The present study aimed to evaluate the haematological and immunophenotypic profile of cattle infected with bovine papillomavirus (BPV). Blood samples were collected from 10 animals with clinical cutaneous BPV and without clinical papillomatosis (control). Haematological analysis demonstrated a significant reduction in haemoglobin and haematocrit for BPV-infected animals. The results also showed an increase of natural killer cells and a decrease of γδ+ T-cells and the CD4+/CD8+ ratio for the BPV group when compared to the control group. The infection was also found to stimulate a pro-inflammatory profile with the participation of CD8+T cells producing elevated IFN-γ and IL-17. These findings, although preliminary, provide a better understanding of the immune response of cattle infected with BPV.

Evaluation of parameters related to libido and semen quality in Zebu bulls naturally infected with Trypanosoma vivax.

BACKGROUND: Trypanosomiasis is a disease caused by Trypanosoma (Dutonella) vivax, a hemoprotozoa that can affect bovines. In South America, the sanguineous form is mechanically transmitted from one mammalian host (ruminant) to another by the bite of a blood-sucking insect or by needles contaminated with infected blood. The negative impact of the parasitosis caused by T. vivax infection on the reproductive activity of male and female ruminants is known to reduce fertility. In males, alterations such as degeneration, diffuse or interlobular inflammatory infiltrate found in ovine and bovine testicles, can affect fertility through decreased sperm quality. This study evaluated the impact of natural infection with T. vivax on Zebu bulls from the Central Station of Artificial Insemination (CSAI) with regard to libido and the negative effects caused by this protozoan on semen quality. METHODS: Blood samples of 44 animals were collected to evaluate the presence of the trypomastigote form of T. vivax in blood smears obtained from hematocrit and buffy coat, and antibody titer IgG anti T. vivax in indirect Immunoflorescence (IFI). Furthermore, data related to libido, ejaculate volume, spermatic concentration, and seminal vigor were recorded for these animals employing the criteria of the CSAI. RESULTS: Nine animals (20.45 %) showed T. vivax trypomastigotes and parasitemia between 0.02 and 0.07, and antibody titers from 1:80 to 1:320 in IFI. Twenty nine negative animals in parasitological tests were not reactive in IFI, and six animals presented the antibodies IgG anti T. vivax in IFI. Data on reproductive activity showed that animals infected with T. vivax have a decreased libido and an increased spermatic volume, whereas other factors related to the reproductive process such as spermatic concentration, motility and spermatic force, were unchanged in infected bulls. CONCLUSIONS: The T. vivax infection in Zebu bulls from CSAI caused patent parasitemia, induced a febrile state, promoted reduction in the libido and increased the ejaculate volume. These conditions together may account to decrease the performance of these animals.

Influence of endogamy and mitochondrial DNA on immunological parameters in cattle.

BACKGROUND: Endogamy increases the risk of manifestation of deleterious recessive genes. Mitochondrial DNA allows the separation of American Zebu (Bos indicus and Bos taurus) and evaluate the effect of mitochondrial DNA on productive traits of cattle. However, the effect of endogamy and mitochondrial DNA (mtDNA) on the immune system remains unclear. The aim of this study was to evaluate the association between endogamy, mtDNA and immune parameters. RESULTS: A total of 86 cattle (43 cows and 43 calves) were used in this study. Age, endogamy, milk yield, and origin of mtDNA were measured and their influence on immunological parameters was evaluated. Older cows had increased CD4+ T cells, decreased CD21+ and γδhigh T cells as well as increased CD4+/CD8+ and T/B ratio. Multiple regression analysis indicated that endogamy in calves was associated with increased CD8+ T and CD21+ B lymphocytes, and decreased γδhigh T cells in peripheral blood. Cows with medium and lower endogamy had a lower percentage of B lymphocytes and γδlow T cells and cows with lower endogamy had higher levels of γδ T cells and γδhigh T cells, as well as the CD4+/CD48+ cell ratio. Calves with higher endogamy had higher levels of CD8+ T lymphocytes, whereas calves with lower endogamy had lower levels of γδlow T cells. CONCLUSIONS: These results demonstrated for the first time that endogamy influences the immune system of cattle.

Variação da força de resistência à micro-tração de fragmentos de ossos corticais preservados em diversos meios e a fresco: estudo experimental em coelhos / Variation of the resistance force to the micro-traction of fragments of cortical bones preserved in several means and fresh: Experimental study in rabbits

Devido ao crescente uso dos aloenxertos nas cirurgias ortopédicas, há a necessidade do conhecimento de suas características biomecânicas ao longo do tempo de preservação. O presente trabalho consistiu na análise da força de resistência à micro-tração de amostras de ossos corticais de coelho preservadas em diversos meios por até 180 dias e a fresco. Os resultados revelaram que a resistência e o tempo de preservação apresentaram uma relação inversamente proporcional, significando que, quanto maior o tempo de preservação, menor a resistência física avaliada no ensaio biomecânico de resistência à micro-tração. Dos meios utilizados, a glicerina apresentou menores valores quanto ao teste de resistência, demonstrando, após 30 dias de preservação, apenas 24,58 por cento da força presente no osso a fresco e, aos 180 dias, 1,76 por cento. As amostras submetidas à autoclavagem também demonstraram baixos valores ao final do experimento, quando permaneceram com apenas 12,31 por cento da força presente no osso a fresco. Os ossos preservados em plasma homólogo, líquido de dakin e aqueles criopreservados apresentaram os melhores índices de resistência ao final do experimento, permanecendo, respectivamente, com 82,47; 70,34 e 66,72 por cento da força máxima quando comparados com a resistência dos ossos frescos. Concluiu-se que a escolha do método e o tempo de preservação interferiu diretamente na biomecânica dos ossos corticais, promovendo a diminuição da capacidade de resistência à tração ao longo do período de preservação.

Due to the increasing use of cortical bone allografts in orthopedic surgeries, de knowledge of its biomechanics characteristics during preservation time is needed. The present study consisted in the analyses of the resistance power to the micro-traction of samples of rabbit cortical bones preserved in several means for up to 180 days and fresh. The results showed that the resistance and the preservation time presented an inversely proportional relation, meaning that, the longer the time of preservation, the shorter the physical resistance evaluated in the biomechanical rehearsal of resistance to the micro-traction. The glycerin has presented lower values in relation to the resistance test, showing, after 30 days, only 24.58 percent of the present power in the fresh bone, and by 180 days, 1.76 percent. The samples submitted to autoclavation also showed low values by the end of the experiment, while they remained with just 12.31 percent of the power present in the fresh bone. The bones preserved in homologous plasma, Dakin liquid and the ones cryopreserved showed the best levels of resistance at the end of the experiment, remaining, respectively with 82.47, 70.34 and 66.72 percent of the maximum power, while compared with the resistance of the fresh bones. The conclusion is that the choice of methodology and time of preservation interfered directly in the biomechanics of the cortical bones, promoting decrease of the resistance capacity to the traction along the period of preservation.

Kinetic peculiarities of human tissue kallikrein: 1--substrate activation in the catalyzed hydrolysis of H-D-valyl-L-leucyl-L-arginine 4-nitroanilide and H-D-valyl-L-leucyl-L-lysine 4-nitroanilide; 2--substrate inhibition in the catalyzed hydrolysis of N alpha-p-tosyl-L-arginine methyl ester.

Hydrolysis of D-valyl-L-leucyl-L-lysine 4-nitroanilide (1), D-valyl-L-leucyl-L-arginine 4-nitroanilide (2), and N alpha-p-tosyl-L-arginine methyl ester (3) by human tissue kallikrein was studied throughout a wide range of substrate concentrations. At low substrate concentrations, the hydrolysis followed Michaelis-Menten kinetics but, at higher substrate concentrations, a deviation from Michaelis-Menten behavior was observed. With the nitroanilides, a significant increase in hydrolysis rates was observed, while with the ester, a significant decrease in hydrolysis rates was observed. The results for substrates (1) and (3) can be accounted for by a model based on the hypothesis that a second substrate molecule binds to the ES complex to produce a more active or an inactive SES complex. The deviation observed for substrate (2) can be explained as a bimolecular reaction between the enzyme-substrate complex and a free substrate molecule.