Presence of Anti-T. cruzi Antibodies in Inhabitants and Dogs of Two Rural Settlements in the Sierra de Los Tuxtlas, Veracruz, Mexico.

PURPOSE: The aim of this study was to identify the risk factors associated with house infestation by Triatoma dimidiata as well as with Trypanosoma cruzi infection in humans and owned dogs in two rural communities from the municipality of Catemaco, Veracruz, Mexico. METHODS: One hundred and 16 human blood samples and 34 dog blood samples were collected. The presence of anti-T. cruzi antibodies was determined using four different ELISA assays. Moreover, reactive ELISA sera from humans and dogs were processed by indirect immunofluorescence (IFI) to confirm the presence of anti-T. cruzi antibodies. RESULTS: Serologic tests for T. cruzi infection showed a prevalence of 5.1% (6/116) in humans and of 50% (17/34) in owned dogs. CONCLUSION: The presence of animals (dogs, chickens and wild animals), as well as some characteristics of house construction were identified as risk factors for infestation and infection. Complementary studies must be carried out to allow a better understanding of the transmission dynamics in the state of Veracruz, Mexico, and the implementation of adequate control programs.

Lesion-associated microglia and macrophages mediate corralling and react with massive phagocytosis for debris clearance and wound healing after LPS-induced dopaminergic depletion.

Neuroinflammation contributes to neuronal degeneration in Parkinson's disease (PD). However, how brain inflammatory factors mediate the progression of neurodegeneration is still poorly understood. Experimental models of PD have shed light on the understanding of this phenomenon, but the exploration of inflammation-driven models is necessary to better characterize this aspect of the disorder. The use of lipopolysaccharide (LPS) to induce a neuroinflammation-mediated neuronal loss is useful to induce reliable elimination of dopaminergic neurons. Nevertheless, how this model parallels the PD-like neuroinflammation is uncertain. In the present work, we used the direct LPS injection as a model inductor to eliminate dopaminergic neurons of the substantia nigra pars compacta (SNpc) in rats and reevaluated the inflammatory reaction. High-resolution 3D histological examination revealed that, although LPS induced a reliable elimination of SNpc dopaminergic neurons, it also generated a massive inflammatory response. This inflammation-mediated injury was characterized by corralling, a damaged parenchyma occupied by a vast population of lesion-associated microglia and macrophages (LAMMs) undertaking wound compaction and scar formation, surrounded by highly reactive astrocytes. LAMMs tiled the entire lesion and engaged in long-standing phagocytic activity to resolve the injury. Additionally, modeling LPS inflammation in a cell culture system helped to understand the role of phagocytosis and cytotoxicity in the initial phases of dopaminergic degeneration and indicated that LAMM-mediated toxicity and phagocytosis coexist during LPS-mediated dopaminergic elimination. However, this type of severe inflammatory-mediated injury, and subsequent resolution appear to be different from the ageing-related PD scenario where the architectural structure of the parenchyma is mostly preserved. Thus, the necessity to explore new experimental models to properly mimic the inflammatory compound observed in PD degeneration.

Natural infection with Trypanosoma cruzi in three species of non-human primates in southeastern Mexico: A contribution to reservoir knowledge.

The mechanisms of infection and dispersion of Trypanosoma cruzi among animals, especially in the sylvatic environment, are still not entirely clear, and various aspects of the transmission dynamics of this parasite in the sylvatic environment are still unknown. T. cruzi is a parasite with a great biological and genetic diversity that infects a wide variety of hosts, therefore, transmission cycles of this parasite are complex. The objective of this study was to determine the prevalence of T. cruzi infection and analyze the genetic variability of the discrete typing units (DTUs) of the parasite in three non-human primate species (Alouatta palliata, Alouatta pigra, and Ateles geoffroyi) in southeastern Mexico. A total of one hundred sixty-four serum samples (42 samples of A. pigra, 41 samples of A. palliata (free-ranging) and 81 samples of A. geoffroyi (hosted in care centers)) were analyzed for the detection of anti-T. cruzi antibodies by ELISA assays. The seroprevalence of infection was 23.39% in A. palliata, 21.40% in A. pigra and 16.27% in A. geoffroyi. Additionally, presence of parasite DNA was assessed by PCR, and the identification of DTUs was performed by real-time PCR coupled to High Resolution Melting (qPCR-HRM). Different DTUs (TcI, TcII, TcIII, TcV and TcVI) were found in the analyzed monkeys. In addition, infection of monkeys was not associated with age or gender, but it was associated with the species. This study reveals the risk of infection in the study area and that the different DTUs of the parasite can coexist in the same habitat, indicating that T. cruzi transmission in the study area is very complex and involves many ecological factors. However, there is a need for long-term studies of host-parasite interactions to provide a solid understanding of the ecology of these species and to understand the dispersion strategies of T. cruzi.

Hematological and biochemical blood values in wild populations of black howler monkeys (Alouatta pigra) of Campeche, México.

BACKGROUND: The clinical analyses of free-ranging New World primates are extremely limited. The aim of this study was to obtain baseline data of blood chemistry and hematological values of free-ranging Alouatta pigra. METHOD: 17 males and 17 females were captured. We collected blood from the caudal tail vein; conventional techniques were used to analyze the samples RESULTS: Hemoglobin, hematocrit, and erythrocytes were significantly higher in males than in females. In relation to biochemical blood values, albumin/globulin ratio, cholesterol, triglycerides, calcium, phosphorus, magnesium, and iron were significantly higher in males than in females, while creatinine was significantly higher in females than in males. CONCLUSIONS: In general, measured parameters are similar to those of other primates and will be used as reference values for futures studies.

Variation in the Extraction Efficiency of Estradiol and Progesterone in Moist and Lyophilized Feces of the Black Howler Monkey (Alouatta pigra): Alternative Methods.

Several fecal steroid extraction techniques have been developed to measure the ovary function in different species of mammals. However, regardless of the method of extraction and the sample type chosen, it has been observed that they can yield results with different percentages of recuperation. The objective of this study was to determine whether the type of substratum, solvent and extraction method used have any influence on the extraction efficiency in the feces of Alouatta pigra (black howler monkey). For this purpose we used two methods: agitation and ebullition. With each method, we utilized moist and lyophilized feces. The validation of radioimmunoassay method was accurate and precise for quantify estradiol and progesterone in lyophilized feces of A. pigra. To both of which ethanol and methanol, absolute and at 80%, were added, besides the hormones (125)I-Estradiol and (125)I-Progesterone. The extraction efficiency for (125)I-Estradiol was from 87.72 ± 3.97 to 41.24 ± 2.67%, and for (125)I-Progesterone from 71.15 ± 4.24 to 42.30 ± 1.19% when we used the agitation method. Whereas with the ebullition method, the extraction efficiency for (125)I-Estradiol ranged from 86.89 ± 2.66 to 71.68 ± 3.02% and for (125)I-Progesterone from 98.31 ± 1.26 to 85.40 ± 1.98%. Due to the differences found in these assays, which depend on the method used, the type of feces employed and the type of solvent added to them, we recommend the ebullition method and the lyophilized feces of A. pigra for extracting the hormones, since in moist feces there may exist variables which might interfere in the quantification of (125)I-Estradiol and (125)I-Progesterone.

Blood parameters are little affected by time of sampling after the application of ketamine in black howler monkeys (Alouatta pigra).

BACKGROUND: Ketamine hydrochloride is an anesthetic commonly utilized to obtain biological samples in various non-human primates. Its application alters individual hematologic and biochemical values. The aim of this study was to analyze its effect on blood parameters of Alouatta pigra. METHOD: We collected blood samples at 10 and 40 minutes after the application of ketamine in 12 adult female A. pigra living in free-ranging conditions. RESULTS: The analysis showed that 40 minutes after application of ketamine, the number of platelets, lymphocytes and concentration of phosphorus decreased; however, creatinine, cholesterol, triglycerides, and potassium values increased. CONCLUSIONS: Our results suggest that ketamine appears to have little effect on the hematology and blood biochemistry of Alouatta pigra females with respect to those reported for other non-human primates. It is also important to consider the elapsed time after their application when taking blood samples for proper interpretation of the hemogram of Alouatta pigra females.