Evaluating TROPOMI and MODIS performance to capture the dynamic of air pollution in São Paulo state: A case study during the COVID-19 outbreak.

Atmospheric pollutant data retrieved through satellite sensors are continually used to assess changes in air quality in the lower atmosphere. During the COVID-19 pandemic, several studies started to use satellite measurements to evaluate changes in air quality in many different regions worldwide. However, although satellite data is continuously validated, it is known that its accuracy may vary between monitored areas, requiring regionalized quality assessments. Thus, this study aimed to evaluate whether satellites could measure changes in the air quality of the state of São Paulo, Brazil, during the COVID-19 outbreak; and to verify the relationship between satellite-based data [Tropospheric NO2 column density and Aerosol Optical Depth (AOD)] and ground-based concentrations [NO2 and particulate material (PM; coarse: PM10 and fine: PM2.5)]. For this purpose, tropospheric NO2 obtained from the TROPOMI sensor and AOD retrieved from MODIS sensor data by using the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm were compared with concentrations obtained from 50 automatic ground monitoring stations. The results showed low correlations between PM and AOD. For PM10, most stations showed correlations lower than 0.2, which were not significant. The results for PM2.5 were similar, but some stations showed good correlations for specific periods (before or during the COVID-19 outbreak). Satellite-based Tropospheric NO2 proved to be a good predictor for NO2 concentrations at ground level. Considering all stations with NO2 measurements, correlations >0.6 were observed, reaching 0.8 for specific stations and periods. In general, it was observed that regions with a more industrialized profile had the best correlations, in contrast with rural areas. In addition, it was observed about 57% reductions in tropospheric NO2 throughout the state of São Paulo during the COVID-19 outbreak. Variations in air pollutants were linked to the region economic vocation, since there were reductions in industrialized areas (at least 50% of the industrialized areas showed >20% decrease in NO2) and increases in areas with farming and livestock characteristics (about 70% of those areas showed increase in NO2). Our results demonstrate that Tropospheric NO2 column densities can serve as good predictors of NO2 concentrations at ground level. For MAIAC-AOD, a weak relationship was observed, requiring the evaluation of other possible predictors to describe the relationship with PM. Thus, it is concluded that regionalized assessment of satellite data accuracy is essential for assertive estimates on a regional/local level. Good quality information retrieved at specific polluted areas does not assure a worldwide use of remote sensor data.

How mobility restrictions policy and atmospheric conditions impacted air quality in the State of São Paulo during the COVID-19 outbreak.

Mobility restrictions are among actions to prevent the spread of the COVID-19 pandemic and have been pointed as reasons for improving air quality, especially in large cities. However, it is crucial to assess the impact of atmospheric conditions on air quality and air pollutant dispersion in the face of the potential variability of all sources. In this study, the impact of mobility restrictions on the air quality was analyzed for the most populous Brazilian State, São Paulo, severely impacted by COVID-19. Ground-based air quality data (PM10, PM2.5, CO, SO2, NOx, NO2, NO, and O3) were used from 50 automatic air quality monitoring stations to evaluate the changes in concentrations before (January 01 - March 25) and during the partial quarantine (March 16 - June 30). Rainfall, fires, and daily cell phone mobility data were also used as supplementary information to the analyses. The Mann-Whitney U test was used to assess the heterogeneity of the air quality data during and before mobility restrictions. In general, the results demonstrated no substantial improvements in air quality for most of the pollutants when comparing before and during restrictions periods. Besides, when the analyzed period of 2020 is compared with the year 2019, there is no significant air quality improvement in the São Paulo State. However, special attention should be given to the Metropolitan Area of São Paulo (MASP), due to the vast population residing in this area and exposed to air pollution. The region reached an average decrease of 29% in CO, 28% in NOx, 40% in NO, 19% in SO2, 15% in PM2.5, and 8% in PM10 concentrations during the mobility restrictions period compared to the same period in 2019. The only pollutant that showed an increase in concentration was ozone, with a 20% increase compared to 2019 during the mobility restrictions period. Before the mobility restrictions period, the region reached an average decrease of 30% in CO, 39% in NOx, 63% in NO, 12% in SO2, 23% in PM2.5, 18% in PM10, and 16% in O3 concentrations when compared to the same period in 2019. On the other hand, Cubatão, a highly industrialized area, showed statistically significant increases above 20% for most monitored pollutants in both periods of 2020 compared to 2019. This study reinforces that the main driving force of pollutant concentration variability is the dynamics of the atmosphere at its various time scales. An abnormal rainy season, with above average rainfall before the restrictions and below average after it, generated a scenario in which the probable significant reductions in emissions did not substantially affect the concentration of pollutants.

Glutathione and IGF-1 in bovine seminal cryopreservation: oxidative stress response and pregnancy rate / [Glutationa e IGF-1 na criopreservação seminal bovina: resposta do estresse oxidativo e taxa de gestação]

The objective of this study was to evaluate the rate of conception, metabolic, and structural conditions of cryopreserved bovine sperm cells, plus extender with IGF-1 and glutathione (GSH). 12 ejaculations of Nelore bulls were used, submitted to treatments: control, gSH (2mM/mL), IGF-1 (100ng/mL) and gSH (1mM/mL) + IGF-1 (50ng/mL). After cryopreservation and thawing the semen passed the fast thermo resistance test (TTR), plasma membrane and acrosomal integrity (PIAI), mitochondrial membrane potential (AP), oxidative stress, and conception rate. Tukey test was used for the statistical analysis of the parametric variables and the Friedman test for nonparametric. The gestation percentage was compared by the Chi-square test. There was no statistical difference (P<0.05) between treatments for the TTRr variable. Otherwise in the oxidative stress evaluated with the CellROX probe was noted that the IGF-1 showed the highest number of reactive cells (P<0.05). The PIAI, AP and gestation rate showed no difference among treatments (P>0.05), with an average of conceptions of 36.58%. It is concluded that IGF-1, gSH and their association did not cause changes in sperm motility, mitochondrial potential, plasma and acrosomal membrane integrity. IGF-1 increased oxidative stress, however, there was no difference in the gestation rate among the treatments.(AU)

Objetivou-se avaliar a taxa de concepção, as condições metabólicas e estrutural das células espermáticas bovinas criopreservadas, acrescidas de diluidores com fator de crescimento semelhante à insulina do tipo 1(IGF-1) e glutationa (GSH). Foram utilizados 12 ejaculados de touros da raça Nelore, submetidos aos tratamentos: controle, gSH (2mM/mL), IGF-1 (100ng/mL) e gSH (1mM/mL) + IGF-1 (50ng/mL). Após a criopreservação e descongelação, o sêmen passou pelos testes de termorresistência rápida (TTRr), integridade de membrana plasmática e acrossomal (PIAI), alto potencial mitocondrial (AP), estresse oxidativo e taxa de concepção. Utilizou-se o teste de Tukey para as análises estatísticas das variáveis paramétricas e o teste de Friedman para as não paramétricas, com significância de 5%. A percentagem de gestação foi comparada pelo teste do qui-quadrado. Não hove diferença estatística (P<0,05) entre os tratamentos para a variável TTRr. Já no estresse oxidativo avaliado com a sonda CellROX, observou-se que o IGF-1 apresentou maior quantidade de células reativas (P<0,05), 36,38± 24,10. A PIAI, o AP e a taxa de gestação não apresentaram diferença entre tratamentos (P>0,05), com média de concepções de 36,58%. Conclui-se que o IGF-1, a gSH e a sua associação não causaram mudanças na motilidade espermática, no potencial mitocondrial, na integridade da membrana plasmática e acrossomal. O IGF-1 aumentou o estresse oxidativo, porém sem diferença na taxa de gestação entre os tratamentos.(AU)

Insulina e IGF-1 no meio extensor de criopreservação seminal bovina / Insulin and IGF-I in extender medium for bovine semen cryopreservation

Objetivou-se avaliar a condição metabólica e estrutural das células espermáticas bovinas após congelação, com adição prévia de IGF-I e insulina no meio diluidor seminal. Os ejaculados de seis touros Nelore foram submetidos a quatro tratamentos: controle; insulina (100µUI/mL); IGF-I (150ng/mL) e insulina + IGF-I (50µUI/mL e 75ng/mL, respectivamente). Após a congelação, realizaram-se os testes de termorresistência rápida, coloração pelo corante azul de tripan e Giemsa, além da análise computadorizada da motilidade espermática, da integridade das membranas plasmática e acrossomal, e da peça intermediária por meio de sondas fluorescentes. O teste de termorresistência rápida apresentou efeito dentro do tempo de cada tratamento, mas não entre os tratamentos. Na análise computadorizada da motilidade espermática, foram observados movimento, motilidade e velocidade espermáticos; não houve efeitos dos tratamentos sobre qualquer uma dessas variáveis. Respostas iguais foram obtidas com as sondas fluorescentes e o corante azul de tripan/Giemsa. A adição de insulina e IGF-I, de forma isolada ou combinada, ao meio diluidor para congelação de sêmen não produziu efeitos sobre as condições metabólica e estrutural das células espermáticas.(AU)

This study aimed to evaluate the metabolic and structural condition of the spermatic bovine cells after the freezing, with addition, previously, of IGF-I and Insulin in the seminal thinner medium. The semen of 6 Nellore bulls were submitted to four treatments: Control, Insulin (100µUI/mL); IGF-I (150ng/mL) and Insulin + IGF-I (50µUI/mL and 75ng/mL, respectively). After freezing, rapid resistance tests, Tripan and Giemsa Blue staining, and computerized analysis of sperm motility and integrity of the plasma and acrosomal membranes and the intermediate part were performed by fluorescent probes. The term rapid resistance test had effect within the time of each treatment, but not between treatments. In the computer analysis of sperm motility, sperm movement, motility and velocity no effects of treatments were observed on any of these variables. The same results were obtained with the fluorescent probes and the Blue dye Trypan / Giemsa. The addition of Insulin and IGF-I, alone or in combination, to the semen freezing dilution medium had no effect on the metabolic and structural condition of sperm cells.(AU)

Does supplementation of vitamin C, reduced glutathione or their association in semen extender reduce oxidative stress in bovine frozen semen? / A suplementação de vitamina C, glutationa reduzida ou sua associação no diluidor de sêmen reduz o estresse oxidativo no sêmen congelado bovino?

The aim of this study was to evaluate the addition of vitamin C, reduced glutathione and the association thereof to the bovine semen cryopreservation extender. The ejaculate from nine bulls were divided into four fractions, each corresponding to a treatment, namely: control group-semen diluted with Tris-yolk extender; vitamin C group-semen diluted in Tris-yolk extender supplemented with vitamin C (2.5mmol/mL); glutathione group-semen diluted in Tris-yolk extender supplemented with reduced glutathione (2.5mmol/mL) and associated group-semen diluted in Tris-yolk extender supplemented with vitamin C (1.25mmol/mL) and reduced glutathione (1.25mmol/mL). Afterwards, the semen was packed into French straws and submitted to cryopreservation using automated equipment. After cryopreservation, the semen was thawed and evaluated considering sperm motility, morphology, plasma membrane, acrosome, mitochondrial potential and oxidative stress, as well as the thermo resistance test. Extender's supplementation with the association of vitamin C and reduced glutathione showed benefic effects on sperm motility and preservation of plasma and acrosomal membranes during semen cryopreservation, being also the group that showed higher values of reactive oxygen species. Thus, the association of both antioxidants contributed to the preservation of sperm cells in every analyzed characteristic, suggesting its use on bovine semen cryopreservation.(AU)

O objetivo deste estudo foi avaliar a adição de vitamina C, glutationa reduzida e sua associação ao diluidor de criopreservação de sêmen bovino. O ejaculado de nove touros foi dividido em quatro frações, cada uma correspondendo a um tratamento, a saber: grupo controle - sêmen diluído em Tris-gema; grupo vitamina C - sêmen diluído em Tris-gema, suplementado com vitamina C (2,5mmol/mL); grupo glutationa - sêmen diluído em Tris-gema, suplementado com glutationa reduzida (2,5mmol/mL) e grupo sêmen associado - diluído em Tris-gema, suplementado com vitamina C (1,25mmol/mL) e glutationa reduzida (1,25mmol/mL ). Posteriormente, o sêmen foi envasado em palhetas francesas e submetido à criopreservação por meio de equipamento automatizado. Após a criopreservação, o sêmen foi descongelado e avaliado quanto à motilidade espermática, à morfologia, à membrana plasmática, ao acrossoma, ao potencial mitocondrial e ao estresse oxidativo, bem como pelo teste de resistência térmica. A suplementação de extensor com a associação de vitamina C e glutationa reduzida mostrou efeitos benéficos sobre a motilidade espermática e a preservação das membranas plasmática e acrossomal durante a criopreservação de sêmen, sendo também o grupo que apresentou maiores valores de espécies reativas de oxigênio. Assim, a associação de ambos os antioxidantes contribuiu para a preservação dos espermatozóides em todas as características analisadas, sugerindo sua utilização na criopreservação de sêmen bovino.(AU)

Cacao Phylloplane: The First Battlefield against Moniliophthora perniciosa, Which Causes Witches' Broom Disease.

The phylloplane is the first contact surface between Theobroma cacao and the fungus Moniliophthora perniciosa, which causes witches' broom disease (WBD). We evaluated the index of short glandular trichomes (SGT) in the cacao phylloplane and the effect of irrigation on the disease index of cacao genotypes with or without resistance to WBD, and identified proteins present in the phylloplane. The resistant genotype CCN51 and susceptible Catongo presented a mean index of 1,600 and 700 SGT cm-2, respectively. The disease index in plants under drip irrigation was reduced by approximately 30% compared with plants under sprinkler irrigation prior to inoculation. Leaf water wash (LWW) of the cacao inhibited the germination of spores by up to 98%. Proteins from the LWW of CCN51 were analyzed by two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis followed by tandem mass spectrometry. The gel showed 71 spots and identified a total of 42 proteins (28 from the plant and 14 from bacteria). Proteins related to defense and synthesis of defense metabolites and involved in nucleic acid metabolism were identified. The results support the hypothesis that the proteins and water-soluble compounds secreted to the cacao phylloplane participate in the defense against pathogens. They also suggest that SGT can contribute to the resistance of cacao.

Zeólitas naturais na dieta de frangos de corte / Natural zeolites in broiler diet

O objetivo deste trabalho foi avaliar o efeito da inclusão de 0,5% da zeólita natural clinoptilolita na dieta de frangos de corte sobre o consumo de água, ração e características das excretas. Foi conduzido um ensaio em gaiolas metabólicas, com frangos de corte de linhagem comercial, no período de 14 a 23 dias de idade. O experimento foi constituído de dois grupos de aves, sendo que um recebeu dieta sem inclusão de zeólitas (controle) e outro dieta com inclusão de 0,5% de zeólita (clinoptilolita) em rações isonutritivas, em um delineamento inteiramente ao acaso, com 10 repetições de 10 aves. Avaliou-se o consumo de água e de ração, nas excretas, pH, teor de nitrogênio total e umidade. A inclusão de 0,5% de zeólitas naturais na dieta não alterou (P>0,05) o consumo de água e de ração e o teor de nitrogênio das excretas, entretanto, reduziu (P<0,05) o pH e a umidade das excretas. Conclui-se que a inclusão de 0,5% de zeólitas naturais na dieta de frangos de corte reduz o pH e a umidade das excretas e pode ser utilizada como aditivo alimentar sem prejudicar o consumo de água e de ração.(AU)

The aim of this study was to evaluate the addition of 0.5% natural zeolites (clinoptilolite) to the diet of broilers and their effect on water and feed intake and excreta characteristics. The test was carried out in metabolic cages, with commercial line broilers, in the period from 14 to 23 days old. The experiment was conducted with two groups of broilers: one group received diet without zeolite inclusion (control) and the other received a diet with 0.5% inclusion of zeolite (clinoptilolite) in balanced diets, in a completely randomized design, with 10 replicates of 10 broilers. Water and feed intake, pH, total nitrogen, and moisture of excreta were evaluated. The inclusion of 0.5% of natural zeolites in the diet did not change (P>0.05) the water and feed intake and total nitrogen of excreta, nevertheless, it decreased (P<0.05) the pH and moisture of excreta. We conclude that the addition of 0.5% natural zeolites to the diet of broilers decreases pH and moisture of excreta and can be used as feed additive without compromising water and feed intake.(AU)

Chlorinated drinking water for lightweight laying hens / Cloração na água de dessedentação para poedeiras leves

The study aimed to evaluate the effect of different levels of chlorine in drinking water of laying hens on zootechnical performance, eggs shell quality, hemogasometry levels and calcium content in tibia. 144 Hy-Line laying hens, 61 weeks old, were used distributed in 24 metabolism cages. They were subjected to water diets, for a period of 28 days, using sodium hypochlorite as a chlorine source in order to obtain the following concentrations: 5ppm (control), 20ppm, 50ppm, and 100ppm. Their performance was evaluated through water consumption, feed intake, egg production and weight, egg mass, feed conversion. Shell quality was measured by specific gravity. At the end of the experiment, arterial blood was collected for blood gas level assessment and a poultry of each replicate was sacrificed to obtain tibia and calcium content measurement. There was a water consumption reduction from 20ppm of chlorine and feed intake reduction in poultry receiving water with 100ppm of chlorine. The regression analysis showed that the higher the level of chlorine in water, the higher the reduction in consumption. There were no differences in egg production and weight, egg mass, feed conversion, specific gravity, tibia calcium content, and hemogasometry levels (hydrogenionic potential, carbon dioxide partial pressure, oxygen partial pressure, sodium, potassium, chloride, bicarbonate, carbon dioxide total concentration, anion gap and oxygen saturation). The use of levels above 5ppm of chlorine is not recommended in the water of lightweight laying hens.(AU)

Objetivou-se avaliar o efeito de diferentes níveis de cloro na água de dessedentação de poedeiras sobre o desempenho zootécnico, a qualidade da casca dos ovos, os índices hemogasométricos e o teor de cálcio na tíbia. Foram utilizadas 144 poedeiras leves Hy Line, de 61 semanas de idade, distribuídas em 24 gaiolas de metabolismo. As aves foram submetidas, durante um período de 28 dias, a dietas hídricas utilizando-se hipoclorito de sódio como fonte de cloro para compor as seguintes concentrações: 5ppm (controle), 20ppm, 50ppm e 100ppm. O desempenho foi avaliado mediante o consumo de água e ração, a produção e o peso dos ovos, a massa de ovos e a conversão alimentar. A qualidade da casca foi aferida por meio da gravidade específica. Ao final do experimento, coletou-se sangue arterial para avaliação dos índices hemogasométricos e sacrificou-se uma ave de cada repetição para coleta de tíbias e aferição do teor de cálcio. Verificou-se redução do consumo de água a partir de 20ppm de cloro e no consumo de ração em aves que receberam água com 100ppm de cloro. A análise de regressão demonstrou que quanto maior for o nível de cloro na água, maior será a redução no consumo. Não foram observadas diferenças na produção e no peso dos ovos, na massa de ovos, na conversão alimentar, na gravidade específica dos ovos, no teor de cálcio nas tíbias e nos índices hemogasométricos (potencial hidrogeniônico, pressão parcial de gás carbônico, pressão parcial de oxigênio, sódio, potássio, cloro, bicarbonato, concentração total de dióxido de carbono, ânion gap e saturação de oxigênio). Não se recomenda a utilização de níveis superiores a 5ppm de cloro na água de dessedentação de poedeiras leves.(AU)

Natural zeolites in diet or litter of broilers.

This study aims to analyse the influence of adding natural zeolites (clinoptilolite) to the diet or litter of broilers and their effects on growth performance, carcass yield and litter quality. Three consecutive flocks of broilers were raised on the same sawdust litter, from d 1 to d 42 of age, and distributed in three treatments (control with no added zeolites, addition of 5 g/kg zeolite to diet and addition of 100 g/kg zeolites to litter). The addition of zeolites to the diet or litter did not affect growth performance or carcass yield. The addition of zeolites to the diet did not influence moisture content of the litter, ammonia volatilisation was reduced only in the first flock and pH of litter was reduced in the second and third flock. However, the addition of zeolites to the litter reduced moisture content, litter pH and ammonia volatilisation in all flocks analysed. The addition of 5 g/kg zeolite to the diet in three consecutive flocks was not effective in maintaining litter quality, whereas the addition of 100 g/kg natural zeolites to sawdust litter reduced litter moisture and ammonia volatilisation in three consecutive flocks raised on the same litter.

Conjunctival flora, Schirmer's tear test, intraocular pressure, and conjunctival cytology in neotropical primates from Salvador, Brazil.

BACKGROUND: This study aimed to establish reference values for selected ophthalmic diagnostic tests in healthy neotropical primates from Salvador, Brazil. METHODS: A total of 73 intact adults, including Callithrix jacchus (n = 31), Callithrix penicillata (n = 8), Cebus sp. (n = 22), and Cebus xanthosternos (n = 9) were used to evaluate the normal conjunctival bacterial flora. Cebus xanthosternos (n = 12) were used to evaluate tear production with Schirmer's tear test (STT), intraocular pressure (IOP), and conjunctival cytology. RESULTS: For all animals evaluated, Gram-positive bacteria were predominant. Results of the diagnostic tests in Cebus xanthosternos were as follows: STT: 14.92 ± 5.46 mm/minutes, IOP: 19.62 ± 4.57 mmHg, and conjunctival cytology revealed intermediate squamous epithelial cells in great quantities. CONCLUSIONS: These ophthalmic reference values will be particularly useful to diagnose discrete or unusual pathological changes in the neotropical primates eye.

[Preliminary evaluation of the insecticide susceptibility in Anopheles gambiae and Culex quinquefasciatus from Lobito (Angola), using WHO standard assay]. / Premiers tests OMS d'évaluation de la sensibilité aux insecticides chez Anopheles gambiae et Culex quinquefasciatus à Lobito, Angola.

Field collections of the most common urban mosquito vectors Anopheles gambiae and Culex quinquefasciatus were carried out in June 2003, March 2004 and November 2005 to gather preliminary data on the insecticide susceptibility in mosquitoes from Lobito (Angola) using the WHO standard bioassays. Bioassays were performed on F0 adults emerging from the field larval collections and on unfed adults from landing catches on volunteers. Batches of mosquitoes from three selected locations (Alto Liro, San Jao and Bela Vista) were exposed for 1 hour to several insecticides such as DDT 4%, carbosulfan 0.4%, permethrin 1%, deltamethrin 0.05% and cyfluthrin 0.15%, in order to estimate the immediate knockdown times (kdT50 and kdT95) and the mortality rate after exposure. The results revealed that mosquito susceptibility to insecticides varied depending on the insecticide, the site and the period of collection. The main local malaria vector A. gambiae (both M and S forms) was basically resistant to DDT and susceptible to all pyrethoids, regardless of the period and the site of collections. The overall mortality rate due to DDT was 73% in Alto Liro, 89% in San Jao and varied depending on the period in Bela Vista between 95% in March 2004 and 100% in November 2005. The mortality due to pyrethoids was 100% at all locations, with the kdT50 and KdT95 times ranging between 9 and 16 minutes and between 18 and 29 minutes, respectively. Concerning the C. quinquefasciatus, populations from Yard and Caponte were resistant to all insecticides tested; the mortality rate was 40% with deltamethrin and 70% with permethrin, while no lethal effect was observed with DDT or carbosulfan. In conclusion, despite its probable high resistance to DDT, the main local malaria vector A. gambiae remained fully susceptible to pyrethroids. This could forecast a good biological efficacy of the scheduled vector control interventions in Angola, based on a large-scale distribution of long-lasting, insecticide-treated nets and on the implementation of indoor residual spraying. The local vector control programme must include well-adapted IEC campaigns and full participation of the community for better management of the insecticide resistance in targeted mosquitoes and for better control of malaria vector populations.

Disarray of sarcomeric alpha-actinin in cardiomyocytes infected by Trypanosoma cruzi.

Infection with Trypanosoma cruzi causes acute myocarditis and chronic cardiomyopathy. Remarkable changes have been demonstrated in the structure and physiology of cardiomyocytes during infection by this parasite that may contribute to the cardiac dysfunction observed in Chagas' disease. We have investigated the expression of alpha-actinin, an actin-binding protein that plays a key role in the formation and maintenance of Z-lines, during the T. cruzi-cardiomyocyte interaction in vitro. Immunolocalization of alpha-actinin in control cardiomyocytes demonstrated a typical periodicity in the Z line of cardiac myofibrils, as well as its distribution at focal adhesion sites and along the cell-cell junctions. No significant changes were observed in the localization of alpha-actinin after 24 h of infection. In contrast, depletion of sarcomeric distribution of alpha-actinin occurred after 72 h in T. cruzi-infected cardiomyocytes, while no change occurred at focal adhesion contacts. Biochemical assays demonstrated a reduction of 46% and 32% in the expression of alpha-actinin after 24 h and 72 h of infection, respectively. Intracellular parasites were also stained with an anti-alpha-actinin antibody that recognized a protein of 78 kDa by Western blot. Taken together, our data demonstrate a degeneration of the myofibrils in cardiomyocytes induced by T. cruzi infection, rather than a disassembly of the I bands within sarcomeres.