Inflammatory myopathies and beyond: The dual role of neutrophils in muscle damage and regeneration

Skeletal muscle is one of the most abundant tissues of the human body and is responsible for the generation of movement. Muscle injuries can lead to severe disability. Skeletal muscle is characterized by an important regeneration capacity, which is possible due to the interaction between the myoblasts and immune cells. Neutrophils are fundamental as inducers of muscle damage and as promoters of the initial inflammatory response which eventually allows the muscle repair. The main functions of the neutrophils are phagocytosis, respiratory burst, degranulation, and the production of neutrophil extracellular traps (NETs). An overactivation of neutrophils after muscle injuries may lead to an expansion of the initial damage and can hamper the successful muscle repair. The importance of neutrophils as inducers of muscle damage extends beyond acute muscle injury and recently, neutrophils have become more relevant as part of the immunopathogenesis of chronic muscle diseases like idiopathic inflammatory myopathies (IIM). This heterogeneous group of systemic autoimmune diseases is characterized by the presence of muscle inflammation with a variable amount of extramuscular features. In IIM, neutrophils have been found to have a role as biomarkers of disease activity, and their expansion in peripheral blood is related to certain clinical features like interstitial lung disease (ILD) and cancer. On the other hand, low density granulocytes (LDG) are a distinctive subtype of neutrophils characterized by an enhanced production of NETs. These cells along with the NETs have also been related to disease activity and certain clinical features like ILD, vasculopathy, calcinosis, dermatosis, and cutaneous ulcers. The role of NETs in the immunopathogenesis of IIM is supported by an enhanced production and deficient degradation of NETs that have been observed in patients with dermatomyositis and anti-synthetase syndrome. Finally, new interest has arisen in the study of other phenotypes of LDG with a phenotype corresponding to myeloid-derived suppressor cells, which were also found to be expanded in patients with IIM and were related to disease activity. In this review, we discuss the role of neutrophils as both orchestrators of muscle repair and inducers of muscle damage, focusing on the immunopathogenesis of IIM

INFECCIÓN NATURAL CON Trypanosoma cruzi EN TRIATOMINOS (HEMIPTERA: REDUVIIDAE: TRIATOMINAE), VECTORES DE LA ENFERMEDAD DE CHAGAS EN SAN ANTONIO RAYÓN, JONOTLA, PUEBLA, MÉXICO

The study was carried out in San Antonio Rayón, Jonotla, Puebla, México, from August 2002 to May 2003. The objetive was determite the natural infection index to Trypanosoma cruzi. The metod consist in sprinkling piretrids to 10% at ecotopes of bugs. From a total 388 specimens there were 62 females, 48 males and 278 nymphs. There were 30 triatominae bugs infected with Trypanosoma cruzi. The entomological index were: 44.65% infestation, 4.04 stacking, 1.8 density, 90.625% colonization and 18.40% natural infection. The triatominae bugs were identified as Triatoma dimidiata (Latreille, 1811). In the main were founded within houses, this suggests us that housing quality and the modification of environment with agricultural and cattle objetives may favored the invasion into human dwellings.  En la comunidad de San Antonio Rayón, Jonotla, Puebla, México; se llevó a cabo un estudio sobre la existencia de triatominos intradomiciliarios, con el propósito de determinar el índice de infección natural de Trypanosoma cruzi, durante los meses de Agosto 2002 a Mayo de 2003. Con el propósito de cuantificar los triatominos, fue asperjada una solución de piretriodes al 10% en el interior de las casas y el peridomicilio, donde se observaron acumulaciones de bloque, madera, corrales, etc que constituyen habitáculos naturales de Triatoma dimidiata (Latreille, 1811); de los cuales se capturaron un total de 388 triatominos, distribuidos en 62 hembras, 48 machos y 278 ninfas de diferentes estadios; 30 de los ejemplares presentaron infección natural con Trypanosoma cruzi. Los índices entomológicos fueron: Infestación 44.65%, Hacinamiento 4.04, Densidad 1.8, Colonización 90.63% e infección natural con Trypanosoma cruzi 18.40%. Se encontró un cambio en la etología de esta especie con respecto a comunicaciones anteriores al ser detectado con mayor frecuencia en el intradomicilio, lo cual se justifica por las alteraciones ecológicas de carácter antropogénico producidas en esta zona con fines agrícolas y ganaderos

Infección natural con Trypanosoma cruzi en triatominos (Hemiptera: reduviidae: triatominae), vectores de la enfermedad de Chagas en San Antonio Rayón, Jonotla, Puebla, México.

En la comunidad de San Antonio Rayón, Jonotla, Puebla, México; se llevó a cabo un estudio sobre la existencia de triatominos intradomiciliarios, con el propósito de determinar el índice de infección natural de Trypanosoma cruzi, durante los meses de Agosto 2002 a Mayo de 2003. Con el propósito de cuantificar los triatominos, fue asperjada una solución de piretriodes al 10% en el interior de las casas y el peridomicilio, donde se observaron acumulaciones de bloque, madera, corrales, etc que constituyen habitáculos naturales de Triatoma dimidiata (Latreille, 1811); de los cuales se capturaron un total de 388 triatominos, distribuidos en 62 hembras, 48 machos y 278 ninfas de diferentes estadios; 30 de los ejemplares presentaron infección natural con Trypanosoma cruzi. Los índices entomológicos fueron: Infestación 44.65%, Hacinamiento 4.04, Densidad 1.8, Colonización 90.63% e infección natural con Trypanosoma cruzi 18.40%. Se encontró un cambio en la etología de esta especie con respecto a comunicaciones anteriores al ser detectado con mayor frecuencia en el intradomicilio, lo cual se justifica por las alteraciones ecológicas de carácter antropogénico producidas en esta zona con fines agrícolas y ganaderos

Immune protection against Trypanosoma cruzi induced by TcVac4 in a canine model

Chagas disease, caused by Trypanosoma cruzi, is endemic in southern parts of the American continent. Herein, we have tested the protective efficacy of a DNA-prime/T. rangeli-boost (TcVac4) vaccine in a dog (Canis familiaris) model. Dogs were immunized with two-doses of DNA vaccine (pcDNA3.1 encoding TcG1, TcG2, and TcG4 antigens plus IL-12- and GMCSF- encoding plasmids) followed by two doses of glutaraldehyde-inactivated T. rangeli epimastigotes (TrIE); and challenged with highly pathogenic T. cruzi (SylvioX10/4) isolate. Dogs given TrIE or empty pcDNA3.1 were used as controls. We monitored post-vaccination and post-challenge infection antibody response by an ELISA, parasitemia by blood analysis and xenodiagnosis, and heart function by electrocardiography. Post-mortem anatomic and pathologic evaluation of the heart was conducted. TcVac4 induced a strong IgG response (IgG2>IgG1) that was significantly expanded post-infection, and moved to a nearly balanced IgG2/IgG1 response in chronic phase. In comparison, dogs given TrIE or empty plasmid DNA only developed high IgG titers with IgG2 predominance in response to T. cruzi infection. Blood parasitemia, tissue parasite foci, parasite transmission to triatomines, electrocardiographic abnormalities were significantly lower in TcVac4-vaccinated dogs than was observed in dogs given TrIE or empty plasmid DNA only. Macroscopic and microscopic alterations, the hallmarks of chronic Chagas disease, were significantly decreased in the myocardium of TcVac4-vaccinated dogs.We conclude that TcVac4 induced immunity was beneficial in providing resistance to T. cruzi infection, evidenced by control of chronic pathology of the heart and preservation of cardiac function in dogs. Additionally, TcVac4 vaccination decreased the transmission of parasites from vaccinated/infected animals to triatomines.CONACYT PROY No. 156701 UAEM PROY No. 2381/2006U National Institutes of Health/National Institute of Allergy and Infectious Diseases http://www.niaid.nih.gov/Pages/ default.aspx GRANT NUMBER (AI072538) NJG; American Heart Association http://www.heart.org/ HEARTORG/ GRANT NUMBER (0855059F) to NJG

Activity and residual effect of two formulations of Lambdacyhalothrin sprayed on palm leaves to Rhodnius prolixus

The insecticidal activity and residual effect of two formulations of lambdacyhalothrin were evaluated with Rhodnius prolixus   ;laboratory and field tests were conducted in the State of Chiapas, Mexico. The results indicate that the lethal concentrations of the active ingredient of SC (LC50 = 2.37 and LC90 = 8.5 mg, a.i./m2) were 4-8 times than those with the insecticide WP applied on R. prolixus bugs in palm leaves, a common building material for thatched roofs. Other investigators in South America recommended applying 30 mg a.i./m2 in porous materials; we obtained that the products WP and SC were 3.5 and 16 times more effective on palm leaves. Regarding the evaluation of the residual effects in field spraying, there was up to 15 months persistence after the application of WP in two doses (8.6 mg a.i./m2 and 3.752 mg a.i./m2) with SC. We consider R. prolixus highly susceptible to the employed pyrethroids; they could be used to control this vector in the state of Chiapas, Mexico

Development of genital plates in nymphs of Triatoma pallidipennis, Stål 1872, (Hemiptera: Reduviidae) and its application as sexing method

Searching for morphometric differences between sexes in immature forms, the development of genital plates in the exuviae of Triatoma pallidipennis Stål 1872 nymphs was studied. Differences were found in the form and size of the 9th genital urosternite, it is larger and wider in males as compared to females. This difference is reported in several South American Triatoma species. From our results it is possible to sex early stages from microscopic observation of genital plates in whole insects