Evaluation of coagulation profile in dogs with ACTH-dependent hyperadrenocorticism compared to healthy dogs by rotational thromboelastometry (ROTEM).

Despite their low morbidity, thromboembolic events in hyperadrenocorticism are associated with high mortality. Identifying the main hemostatic abnormalities will improve the prophylactic approach of these canine patients. The aim of this study was to evaluate hemostatic alterations related with ACTH-dependent HAC and its association with hypercoagulable state. For this purpose, 25 dogs diagnosed with ACTH-dependent HAC were compared with 28 healthy dogs as a control group. The hemostatic variables included platelet count, antithrombin, fibrinogen, D-dimer, PT, aPTT, rotational thromboelastometry (ROTEM) and platelet aggregation. Results showed a hypercoagulable state in 32% (8/25) dogs by ROTEM, which had at least 2 of the next features: decreased coagulation time (CT) or clot formation time (CFT) on INTEM (5/25) or EXTEM (4/25); increased maximum clot firmness (MCF) on INTEM (9/25), EXTEM (6/25) and FIBTEM (9/25). These same variables had a significant difference (P≤ 0.05) compared with the control group, as well as the parameters of α-angle and CT. Median fibrinogen levels (310 vs.178 mg/dL), mean platelet aggregation (11.1 vs. 7.9 Ohms), median platelet count (360 vs. 225 ×103/µL) and mean antithrombin activity (140 vs. 119%) were increased in ACTH-dependent HAC dogs compared to control group. PT (7.1 vs. 8.0 seconds) and aPTT (11.6 vs. 15.2 seconds) were also shortened in ACTH-dependent HAC dogs. Our findings confirm the presence of a hypercoagulable tendency in dogs with HAC. Although multifactorial, fibrinogen concentration and MCF FIBTEM showed the relevance of this protein for hypercoagulability in HAC.

Thromboelastometry assessment of mycophenolate mofetil effect on thrombotic risk in dogs with primary and secondary immune-mediated hemolytic anemia and by Erhlichia canis infection / [Avaliação por tromboelastometria do efeito do micofenolato de mofetila no risco trombótico em cães com anemia hemolítica imunomediada primária e secundária à infecção por Erhlichia canis]

This study aimed to identify, by means of thromboelastometry assessment, altered thrombotic risk in dogs with primary and secondary IMHA by E. canis infection after initiating the immunosuppressive therapy with mycophenolate mofetil. The animals' screening was based on complete blood count (CBC), biochemical and urine tests. Dogs with moderate to severe anemia (hematocrit ≤ 25%) which showed symptoms of immune-mediated hemolysis, such as spherocytosis, positive saline agglutination, bilirubinuria and/or hemoglobinuria, were included. Blood and urine samples were collected at two different moments. The first sample (M1) was collected at the time of diagnosis, when hematocrit was lower or equal to 25% before treatment with mycophenolate mofetil (Accord ®); the second sample (M2) was collected after treatment with mycophenolate mofetil, when hematocrit was greater or equal to 30%. Five out of the twelve animals selected died before the end of the study. No reduction in thrombotic risk was observed in the animals treated with mycophenolate mofetil. The animals that presented hypocoagulation at the time of diagnosis showed the worst prognosis, and their reticulocyte count displayed a better prognostic value than their erythrocytes count at the time of diagnosis.(AU)

O objetivo deste estudo foi esclarecer se há alteração do risco trombótico em cães com anemia hemolítica imunomediada primária e secundária a E.canis, avaliado por meio da tromboelastometria, após início de tratamento com micofenolato de mofetila. A seleção dos animais foi baseada na avaliação de hemograma, exame bioquímico e urinálise. Cães com anemia moderada a severa (hematócrito ≤ 25%), com sinais de hemólise imunomediada, como esferocitose, aglutinação em salina positivo, bilirrubinúria e/ ou hemoglobinúria, foram incluídos. As amostras de sangue e urina foram coletadas em dois momentos diferentes. A primeira amostra (M1) foi coletada no momento do diagnóstico, quando o hematócrito era igual ou inferior a 25%, sem fazer uso do micofenolato de mofetila (Accord®), e o segundo momento (M2), após tratamento com micofenolato de mofetila, quando o hematócrito era igual ou maior que 30%. Doze animais foram selecionados, cinco morreram antes do término do estudo. Não houve diminuição do risco trombótico entre os animais tratados com micofenolato de mofetila; os animais que apresentaram menor coagulabilidade apresentaram pior prognóstico, e a contagem de reticulócitos apresentou melhor valor prognóstico do que a contagem de hemácias no momento do diagnóstico.(AU)

Broader prevalence of Wolbachia in insects including potential human disease vectors.

Wolbachia are intracellular, maternally transmitted bacteria considered the most abundant endosymbionts found in arthropods. They reproductively manipulate their host in order to increase their chances of being transmitted to the offspring, and currently are being used as a tool to control vector-borne diseases. Studies on distribution of Wolbachia among its arthropod hosts are important both for better understanding why this bacterium is so common, as well as for its potential use as a biological control agent. Here, we studied the incidence of Wolbachia in a broad range of insect species, collected from different regions of Brazil, using three genetic markers (16S rRNA, wsp and ftsZ), which varied in terms of their sensitivity to detect this bacterium. The overall incidence of Wolbachia among species belonging to 58 families and 14 orders was 61.9%. The most common positive insect orders were Coleoptera, Diptera, Hemiptera and Hymenoptera, with Diptera and Hemiptera having the highest numbers of Wolbachia-positive families. They included potential human disease vectors whose infection status has never been reported before. Our study further shows the importance of using quantitative polymerase chain reaction for high-throughput and sensitive Wolbachia screening.

Antimicrobial action of chelating agents: repercussions on the microorganism development, virulence and pathogenesis.

Infections caused by resistant microorganisms often fail to respond to conventional therapy, resulting in prolonged illness, increased treatment costs and greater risk of death. Consequently, the development of novel antimicrobial drugs is becoming more demanding every day since the existing drugs either have too many side-effects or they tend to lose effectiveness due to the selection of resistant strains. In view of these facts, a number of new strategies to obstruct vital biological processes of a microbial cell have emerged; one of these is focused on the use of metal-chelating agents, which are able to selectively disturb the essential metal metabolism of the microorganism by interfering with metal acquisition and bioavailability for crucial reactions. The chelation activity is able to inhibit the biological role of metal-dependent proteins (e.g., metalloproteases and transcription factors), disturbing the microbial cell homeostasis and culminating in the blockage of microbial nutrition, growth and development, cellular differentiation, adhesion to biotic (e.g., extracellular matrix components, cell and/or tissue) and abiotic (e.g., plastic, silicone and acrylic) structures as well as controlling the in vivo infection progression. Interestingly, chelating agents also potentiate the activity of classical antimicrobial compounds. The differences between the microorganism and host in terms of the behavior displayed in the presence of chelating agents could provide exploitable targets for the development of an effective chemotherapy for these diseases. Consequently, metal chelators represent a novel group of antimicrobial agents with potential therapeutic applications. This review will focus on the anti-fungal and anti-protozoan action of the most common chelating agents, deciphering and discussing their mode of action.

Extracellular S100B protein modulates ERK in astrocyte cultures.

S100B is a calcium binding protein expressed and secreted by astrocytes. Extracellular S100B stimulates the proliferation of astroglial cells and the survival of neurons. Extracellular signal regulated kinases (ERK) are involved in the transduction of proliferating signals in astrocytes. Here we report that S100B significantly increases the activity of ERK in primary cultures of astrocytes, a result which may be related to previous observations of the effect of this protein on glial proliferation. We further confirm that conversion of S100B to its covalent dimer by oxidation of cysteine residues increases its extracellular activity. Although we cannot exclude S100B involvement in other mechanisms of signal transduction, these results suggest that ERK activity in astrocytes is modulated by extracellular S100B.