Chikungunya-Driven Gene Expression Linked to Osteoclast Survival and Chronic Arthralgia.

Chikungunya fever (CHIKF), caused by the Chikungunya virus (CHIKV), manifests as acute febrile illness often associated with polyarthritis and polyarthralgia. Although the acute symptoms resolve within two weeks, many patients experience prolonged joint pain and inflammation, resembling rheumatoid arthritis (RA). This study aimed to identify molecular markers related to joint pain and chronicity in CHIKV-infected individuals by analyzing blood transcriptomes using bulk RNA sequencing. B- and T-cell receptor (BCR and TCR) diversity was assessed through computational analysis of RNA-seq data, revealing a significant reduction in CDR3 diversity in CHIKV-infected individuals compared to healthy controls. This reduced diversity was associated with the upregulation of genes involved in osteoclast differentiation and activation, particularly through the RANK/RANKL signaling pathway. These findings suggest a potential link between immune dysregulation and enhanced osteoclast activity, which may contribute to the persistence of joint pain in chronic CHIKF. Targeting osteoclast-related pathways could offer therapeutic strategies for managing chronic symptoms in CHIKF patients.

Identification of third stage larvae of strongyles and molecular diagnosis of Strongylus vulgaris in the feces of Thoroughbred horses kept in training centers in Rio de Janeiro, Brazil.

The aims of the present study were to identify strongyles in the feces of Thoroughbred horses based on larval morphology; to detect Strongylus vulgaris using molecular diagnosis and compare results to those of feces culture; and to determine the association between the presence of S. vulgaris with corresponding animal information (age range, gender, and anthelmintic use). Feces of horses kept in six Training Centers in Rio de Janeiro State, that showed the presence of ≥500 eggs per gram of feces (EPG) were subjected to strongyle identification. Of the 520 fecal samples collected, 35 had an EPG ≥ 500. After fecal culture for L3 larvae identification, DNA was extracted, subjected to PCR to amplify the ITS2 region DNA fragment of S. vulgaris, and sequenced. A total of 3500 larvae were analyzed. Most were classified as small strong (99.7%), with an emphasis on the type A subfamily of Cyathostominae. Forms of S. vulgaris only corresponded to 0.2%. In all, 25 samples showed amplified S. vulgaris DNA products and 11 showed nucleotide sequences with high sequence identity. Fecal culture and PCR results showed poor agreement (kappa = 0.105) for S. vulgaris diagnosis. Age, gender, anthelmintic use, and anthelmintic administration interval were not statistically significant. The present study showed the presence of S. vulgaris in the feces of horses kept in Rio de Janeiro Training Centers, mainly seen via PCR, which has emerged as the most effective tool for diagnosis. This study made it possible to identify strongyles that infect horses in the region, emphasizing upon the necessity for constant monitoring of the animals.

Coding, Decoding and Retrieving a Message Using DNA: An Experience from a Brazilian Center Research on DNA Data Storage.

DNA data storage based on synthetic oligonucleotides is a major attraction due to the possibility of storage over long periods. Nowadays, the quantity of data generated has been growing exponentially, and the storage capacity needs to keep pace with the growth caused by new technologies and globalization. Since DNA can hold a large amount of information with a high density and remains stable for hundreds of years, this technology offers a solution for current long-term data centers by reducing energy consumption and physical storage space. Currently, research institutes, technology companies, and universities are making significant efforts to meet the growing need for data storage. DNA data storage is a promising field, especially with the advancement of sequencing techniques and equipment, which now make it possible to read genomes (i.e., to retrieve the information) and process this data easily. To overcome the challenges associated with developing new technologies for DNA data storage, a message encoding and decoding exercise was conducted at a Brazilian research center. The exercise performed consisted of synthesizing oligonucleotides by the phosphoramidite route. An encoded message, using a coding scheme that adheres to DNA sequence constraints, was synthesized. After synthesis, the oligonucleotide was sequenced and decoded, and the information was fully recovered.

Critical exponents of master-node network model.

The dynamics of competing opinions in social network plays an important role in society, with many applications in diverse social contexts such as consensus, election, morality, and so on. Here, we study a model of interacting agents connected in networks in order to analyze their decision stochastic process. We consider a first-neighbor interaction between agents in a one-dimensional network with the shape of ring topology. Moreover, some agents are also connected to a hub, or master node, who has preferential choice or bias. Such connections are quenched. As the main results, we observed a continuous nonequilibrium phase transition to an absorbing state as a function of control parameters. By using the finite-size scaling method we analyzed the static and dynamic critical exponents to show that this model probably cannot match any universality class already known.

Epidemiological and genomic investigation of chikungunya virus in Rio de Janeiro state, Brazil, between 2015 and 2018.

Since 2014, Brazil has experienced an unprecedented epidemic caused by chikungunya virus (CHIKV), with several waves of East-Central-South-African (ECSA) lineage transmission reported across the country. In 2018, Rio de Janeiro state, the third most populous state in Brazil, reported 41% of all chikungunya cases in the country. Here we use evolutionary and epidemiological analysis to estimate the timescale of CHIKV-ECSA-American lineage and its epidemiological patterns in Rio de Janeiro. We show that the CHIKV-ECSA outbreak in Rio de Janeiro derived from two distinct clades introduced from the Northeast region in mid-2015 (clade RJ1, n = 63/67 genomes from Rio de Janeiro) and mid-2017 (clade RJ2, n = 4/67). We detected evidence for positive selection in non-structural proteins linked with viral replication in the RJ1 clade (clade-defining: nsP4-A481D) and the RJ2 clade (nsP1-D531G). Finally, we estimate the CHIKV-ECSA's basic reproduction number (R0) to be between 1.2 to 1.6 and show that its instantaneous reproduction number (Rt) displays a strong seasonal pattern with peaks in transmission coinciding with periods of high Aedes aegypti transmission potential. Our results highlight the need for continued genomic and epidemiological surveillance of CHIKV in Brazil, particularly during periods of high ecological suitability, and show that selective pressures underline the emergence and evolution of the large urban CHIKV-ECSA outbreak in Rio de Janeiro.

Prevalence, Risk Factors and Diagnosis of Helminths in Thoroughbred Horses Kept at Training Centers in Rio de Janeiro, Brazil.

The aims of this study were to determine the prevalence of helminths in Thoroughbred horses in Rio de Janeiro; make correlations with risk factors for these infections; and compare the efficiency of three floatation solutions applied in the quantitative Mini-FLOTAC technique. Fecal samples from 520 horses were collected from six training centers between 2019 and 2021. These were subjected to the Mini-FLOTAC technique using three solutions: NaCl (density = 1.200 g/mL), ZnSO4 (1.350 g/mL) and ZnSO4 (1.200 g/mL); and also to qualitative techniques. Information on the horses' sex and age of horses was retrieved from the studbook; data on management from a questionnaire. The overall prevalence of intestinal parasites was 71.9%, with significant differences between training centers (P ≤ .05). On farm C, 87.7% of the samples presented strongylids and 38.7% had Parascaris spp., with the highest egg counts per gram of feces (EPG), of 358.33 and 40.41 respectively. Horses less than 3 years of age were about eight times more likely to be parasitized by strongylids and eleven times more likely to have EPG ≥500. The NaCl solution used in Mini-FLOTAC enabled recovery of the greatest number of samples with high EPG and reached the highest sensitivity values in the diagnosis when compared to the other solutions. Moreover, in the diagnoses, the levels of agreement between the results from the solutions used in Mini-FLOTAC were substantial. However, in estimating the EPG, full agreement between the results from the solutions used in Mini-FLOTAC was not obtained.

Yerba Mate (Ilex paraguariensis) Processing and Extraction: Retention of Bioactive Compounds.

Ilex paraguariensis is a native tree from South America known for the presence of bioactive compounds, and its processed leaves are consumed as hot and cold infusions. After harvest (step 1), the leaves are subjected to flame blanching to inactive the enzymes (step 2), followed by drying and milling (step 3). The impacts of I. paraguariensis processing on leaf composition were investigated by extracting the major compounds (chlorogenic and isochlorogenic acids (3-CQA, 4-CQA, 5-CQA, 3,4-DQA, 3,5-DQA and 4,5-DQA), p-coumaric acid, caffeine and rutin) using different ratios of ethanol and water as extraction solvent (EW 25:75, 50:50, and 75:25 (w/w)). The solvent ratio of EW 50:50 was more effective in extracting the chlorogenic acids isomers, with retention of chlorogenic acids of 3463, 9485, and 9516 µg mL- 1 for steps 1, 2, and 3, respectively. Rutin and p-coumaric acid exhibited similar behavior with the increment of processing steps; however, p-coumaric acid was only detected in steps 2 and 3 for the solvent ratios EW 50:50 and 25:50. The caffeine extraction from I. paraguariensis varied from 936 to 1170 µg mL- 1 for all processing steps, with emphasis on its concentration extracted in step 1. The evolution of processing steps led to a higher retention of phenolic compounds from I. paraguariensis, which was not observed when using different solvent ratios, and the solvent ratio EW 50:50 was more effective for the extraction of chlorogenic acids. The successful extraction of chlorogenic acids from I. paraguariensis in this study proved to be a promising alternative for the use of yerba mate beyond the cuia cup.

First microscopic and molecular parasitological survey of Strongylus vulgaris in Brazilian ponies.

The frequency of gastrointestinal parasites with an emphasis on Strongylus vulgaris was investigated among the Brazilian Pony breed kept on farms in the municipality of Teresópolis, state of Rio de Janeiro. Fecal samples were collected in three stud farms: A (n= 22 animals), B (n= 3), and C (n= 2). Fecal samples were subjected to the quantitative Mini-FLOTAC technique, using three different solutions, and to qualitative techniques. The parasite prevalence was found to be 81.4%. Eggs from strongylids were identified in 74% of the ponies. Eggs of Parascaris spp. were detected in 22.7% of the animals, which were all females of farm A. At this locality, mares were kept with their foals in fenced paddocks all the time. The NaCl solution of d = 1.200 g/ml was generally the one that presented the highest frequency of diagnosis of nematode eggs and the highest mean of fecal eggs per gram. The fecal samples were also subjected to the polymerase chain reaction for amplification of DNA from the ITS2 region for Strongylus vulgaris. Twelve samples presented nucleotide sequences for S. vulgaris. In the end, this study revealed the high frequency (96.3%) of S. vulgaris among ponies on farms in Teresópolis, Rio de Janeiro, Brazil.

Full-scale network analysis reveals properties of the FV protein structure organization.

Blood coagulation is a vital process for humans and other species. Following an injury to a blood vessel, a cascade of molecular signals is transmitted, inhibiting and activating more than a dozen coagulation factors and resulting in the formation of a fibrin clot that ceases the bleeding. In this process, the Coagulation factor V (FV) is a master regulator, coordinating critical steps of this process. Mutations to this factor result in spontaneous bleeding episodes and prolonged hemorrhage after trauma or surgery. Although the role of FV is well characterized, it is unclear how single-point mutations affect its structure. In this study, to understand the effect of mutations, we created a detailed network map of this protein, where each node is a residue, and two residues are connected if they are in close proximity in the three-dimensional structure. Overall, we analyzed 63 point-mutations from patients and identified common patterns underlying FV deficient phenotypes. We used structural and evolutionary patterns as input to machine learning algorithms to anticipate the effects of mutations and anticipated FV-deficiency with fair accuracy. Together, our results demonstrate how clinical features, genetic data and in silico analysis are converging to enhance treatment and diagnosis of coagulation disorders.

Effect of sires' expected progeny difference for scrotal circumference and juvenile ADG on the puberty of crossbred beef heifers.

The early attainment of puberty in heifers is essential for the profitability of the cow-calf farm. This study aimed to evaluate the impact of juvenile average daily gain (ADG) and sire's expected progeny difference (EPD) on puberty of crossbred beef heifers. Sixty Angus × Nellore heifers early weaned (age = 102 ± 4.3 d; initial BW = 103 ± 4.7 kg) were used in a 2 × 2 factorial arrangement. The factor 1 was the sire's EPD for scrotal circumference, in which heifers born from sires with positive EPD were considered precocious (P), and heifers born from sires with negative EPD were considered non-precocious (NP). The factor 2 was the high (HG; ADG = 0.9 kg; ad libitum) and medium ADG (MG; ADG = 0.7 kg) from 3rd to 7th month of age (1st phase). After 1st phase until puberty, all heifers were fed ad libitum (2nd phase). Statistical analysis was performed by SAS. There was an interaction between factors for DMI in the 1st phase (P = 0.02), which PHG heifers had higher DMI than NPHG. There was no effect on puberty rate, BW, age and BCS at puberty comparing HG vs. MG. However, favorable sires' EPD for scrotal circumference induced a higher proportion of puberty (P 87% vs. NP 59%) at 15 months of age. Thus, the ADG in juvenile age did not affect puberty rate, but sires with positive EPD increased puberty rate of Angus × Nellore heifers in heifers fed a high gain diet.

In-Hospital Symptoms of Depression and Anxiety are Strong Risk Factors for Post-Stroke Depression 90 Days After Ischemic Stroke.

Background and Purpose: Acute ischemic stroke (AIS) and depression are the major causes of disability and decreased quality of life worldwide. Psychiatric disorders are common after stroke, especially post-stroke depression (PSD), which affects one-third of survivors. Although frequent, little is known about the real complexity of the pathophysiology and the factors associated with PSD. Methods: This research aimed to provide data about risk factors and predictors of PSD 90 days after AIS. A cohort study was conducted in a tertiary stroke center located in southern Brazil. We interviewed 148 patients with AIS who were consecutively hospitalized between January 2020 and January 2021. The Hospital Anxiety and Depression Scale (HADS) was applied during hospitalization and at follow-up 90 days after AIS. Furthermore, sociodemographic, clinical, and radiological variables were investigated. Predictive factors were assessed using univariate and multivariate linear regression. The impact of the COVID-19 pandemic on the data was also evaluated. Results: The frequency of PSD 90 days after AIS was 33.9%. In-hospital symptoms of depression and anxiety each represented a 2-fold risk for PSD at follow-up. Furthermore, the HADS - anxiety score 90 days after AIS was strongly associated with the HADS - depression value 90 days after stroke (R: .71; B: .56; P < .01). Conclusions: The present study highlighted a noteworthy frequency of PSD 90 days after AIS. Psychiatric variables during hospitalization and in the follow-up appeared to be the leading associated factors with PSD. These data might support the determination of which patients require more psychiatric management.

Effects of lasalocid, narasin, or virginiamycin supplementation on rumen parameters and performance of beef cattle fed forage-based diet.

Two experiments were designed to evaluate the impacts of supplementing lasalocid (LAS), narasin (NAR), or virginiamycin (VRM) on rumen fermentation parameters, apparent nutrient digestibility, and blood parameters (Exp. 1), as well as feed intake and performance (Exp. 2) of Nellore cattle consuming a forage-based diet. In Exp. 1, 32 rumen-fistulated Nellore steers (initial shrunk body weight [BW] = 355 ± 4.4 kg) were assigned to a randomized complete block design. Within block, animals were randomly assigned to one of four treatments: 1) forage-based diet without feed additives (CON), 2) CON diet plus 13 mg/kg of dry matter (DM) of NAR, 3) CON diet plus 20 mg/kg of DM of sodium LAS, or 4) CON diet plus 20 mg/kg of DM of VRM. No treatment effects were detected (P ≥ 0.32) for intake and apparent digestibility of nutrients. Steers fed NAR had the lowest (P ≤ 0.01) molar proportion of acetate on day 28, 56, and 112 vs. CON, LAS, and VRM steers, whereas acetate did not differ (P ≥ 0.25) between LAS, VRM, and CON steers from day 28 to 84. On day 112, steers fed LAS had a lower (P < 0.02) molar proportion of acetate vs. VRM and CON, whereas it did not differ between CON and VRM (P > 0.33). Steers receiving NAR had a greater (P ≤ 0.04) ruminal propionate vs. CON, LAS, and VRM, whereas LAS steers had greater (P < 0.04) propionate vs. CON and VRM steers on day 28 and 112, and it did not differ (P > 0.22) between CON and VRM. In Exp. 2, 160 Nellore bulls were blocked by initial shrunk BW (212 ± 3.1 kg) in a 140-d feedlot trial. Diets contained the same treatments used in Exp. 1. Bulls fed NAR had greater (P < 0.02) average daily gain (ADG) vs. CON and VRM, and similar (P = 0.17) ADG between NAR and LAS, whereas ADG did not differ (P > 0.28) between LAS, VRM, and CON bulls. A treatment effect was detected (P = 0.03) for dry matter intake, being greater in NAR vs. CON, LAS, and VRM bulls, and similar (P > 0.48) between CON, LAS, and VRM bulls. A tendency was detected (P = 0.09) for feed efficiency, which was greater (P < 0.02) in NAR bulls vs. CON and VRM, and similar (P = 0.36) between NAR and LAS bulls. From day 112 to 140, bulls receiving NAR were heavier (P < 0.03) vs. CON, LAS, and VRM bulls, but no differences were observed (P > 0.51) between CON, LAS, and VRM bulls. Collectively, ruminal fermentation profile and intake were impacted by NAR supplementation, which partially contributed to the enhanced performance of Nellore bulls receiving a forage-based diet.

Feed additives are nutritional tools that benefit dietary digestibility and nutrient utilization, alter ruminal fermentation routes, and improve cattle growth and efficiency, thus increasing productivity and profitability in beef cattle systems. Nonetheless, most of the current research focuses on supplementing feed additives in high-concentrate diets. Leaving a significant gap in understanding the influence of feed additives in cattle consuming forage-based diets, especially molecules capable of altering the fermentation process and, consequently, beef cattle performance. Therefore, this experiment aimed to evaluate the impacts of supplementing narasin (NAR), lasalocid (LAS), or virginiamycin (VRM) on rumen fermentation parameters, apparent nutrient digestibility, feed intake, and performance of Bos indicus Nellore cattle consuming a forage-based diet. Including commercially available feed additives into forage-based diets did not impact nutrient intake and digestibility of nutrients. The inclusion of NAR affected ruminal fermentation parameters toward propionate production, positively contributing to animal performance. Ruminal fermentation characteristics and animal growth were not impacted by dietary LAS and VRM, which could be attributed to the dose used in the current experiment, despite the manufacturer's recommendation. This research provides insights into NAR as an important feed additive for forage-based beef cattle diets.

First microscopic and molecular parasitological survey of Strongylus vulgaris in Brazilian ponies / Primeiro levantamento parasitológico microscópico e molecular de Strongylus vulgaris em pôneis brasileiros

The frequency of gastrointestinal parasites with an emphasis on Strongylus vulgaris was investigated among the Brazilian Pony breed kept on farms in the municipality of Teresópolis, state of Rio de Janeiro. Fecal samples were collected in three stud farms: A (n= 22 animals), B (n= 3), and C (n= 2). Fecal samples were subjected to the quantitative Mini-FLOTAC technique, using three different solutions, and to qualitative techniques. The parasite prevalence was found to be 81.4%. Eggs from strongylids were identified in 74% of the ponies. Eggs of Parascaris spp. were detected in 22.7% of the animals, which were all females of farm A. At this locality, mares were kept with their foals in fenced paddocks all the time. The NaCl solution of d = 1.200 g/ml was generally the one that presented the highest frequency of diagnosis of nematode eggs and the highest mean of fecal eggs per gram. The fecal samples were also subjected to the polymerase chain reaction for amplification of DNA from the ITS2 region for Strongylus vulgaris. Twelve samples presented nucleotide sequences for S. vulgaris. In the end, this study revealed the high frequency (96.3%) of S. vulgaris among ponies on farms in Teresópolis, Rio de Janeiro, Brazil.(AU)

A frequência de parasitos gastrointestinais, com ênfase na pesquisa de Strongylus vulgaris, foi investigada entre os Pôneis Brasileiros criados em haras na cidade de Teresópolis, no estado do Rio de Janeiro. Amostras fecais foram coletadas em três haras: A (n=22 animais), B (n=3) e C (n=2). Amostras fecais foram submetidas à técnica quantitativa de Mini-FLOTAC utilizando três diferentes soluções e técnicas qualitativas. A prevalência de parasitos foi de 81,4%. Ovos de estrôngilos foram identificados em 74% dos pôneis. Ovos de Parascaris spp. foram detectados em 22,7% dos animais, sendo todos fêmeas do haras A. Nesta propriedade, as éguas eram mantidas com os pôneis em piquetes cercados durante todo o tempo. A solução de NaCl, com densidade de 1.200 g/ml, foi a que apresentou a maior frequência diagnóstica de ovos de nematoides e a maior contagem de ovos por grama de fezes. As amostras também foram submetidas à reação de polimerase em cadeia para amplificar DNA da região ITS2 de Strongylus vulgaris. Doze amostras fecais apresentaram sequências nucleotídicas de S. vulgaris. Ao final, este estudo demonstrou a alta frequência (96.3%) de S. vulgaris em pôneis mantidos em haras na cidade de Teresópolis, Rio de Janeiro, Brazil.(AU)

Tucuxi-BLAST: Enabling fast and accurate record linkage of large-scale health-related administrative databases through a DNA-encoded approach.

Background: Public health research frequently requires the integration of information from different data sources. However, errors in the records and the high computational costs involved make linking large administrative databases using record linkage (RL) methodologies a major challenge. Methods: We present Tucuxi-BLAST, a versatile tool for probabilistic RL that utilizes a DNA-encoded approach to encrypt, analyze and link massive administrative databases. Tucuxi-BLAST encodes the identification records into DNA. BLASTn algorithm is then used to align the sequences between databases. We tested and benchmarked on a simulated database containing records for 300 million individuals and also on four large administrative databases containing real data on Brazilian patients. Results: Our method was able to overcome misspellings and typographical errors in administrative databases. In processing the RL of the largest simulated dataset (200k records), the state-of-the-art method took 5 days and 7 h to perform the RL, while Tucuxi-BLAST only took 23 h. When compared with five existing RL tools applied to a gold-standard dataset from real health-related databases, Tucuxi-BLAST had the highest accuracy and speed. By repurposing genomic tools, Tucuxi-BLAST can improve data-driven medical research and provide a fast and accurate way to link individual information across several administrative databases.

HIV infection increases the risk of acquiring Plasmodium vivax malaria: a 4-year cohort study in the Brazilian Amazon HIV and risk of vivax malaria.

Globally, malaria and human immunodeficiency virus (HIV) are both independently associated with a massive burden of disease and death. While their co-infection has been well studied for Plasmodium falciparum, scarce data exist regarding the association of P. vivax and HIV. In this cohort study, we assessed the effect of HIV on the risk of vivax malaria infection and recurrence during a 4-year follow-up period in an endemic area of the Brazilian Amazon. For the purpose of this study, we obtained clinical information from January 2012 to December 2016 from two databases. HIV screening data were acquired from the clinical information system at the tropical hospital Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD). The National Malaria Surveillance database (SIVEP malaria) was utilized to identify malaria infections during a 4-year follow-up period after diagnosis of HIV. Both datasets were combined via data linkage. Between 2012 and 2016, a total of 42,121 people were screened for HIV, with 1569 testing positive (3.7%). Out of all the patients diagnosed with HIV, 198 had at least one episode of P. vivax malaria in the follow-up. In the HIV-negative group, 711 participants had at least one P. vivax malaria episode. When comparing both groups, HIV patients had a 6.48 [(5.37-7.83); P < 0.0001] (adjusted relative risk) greater chance of acquiring P. vivax malaria. Moreover, being of the male gender [ARR = 1.41 (1.17-1.71); P < 0.0001], Amerindian ethnicity [ARR = 2.77 (1.46-5.28); P < 0.0001], and a resident in a municipality of the Metropolitan region of Manaus [ARR = 1.48 (1.02-2.15); P = 0.038] were independent risk factors associated with an increased risk of clinical malaria. Education ≥ 8 years [ARR = 0.41 (0.26-0.64); P < 0.0001] and living in the urban area [ARR = 0.44 (0.24-0.80); P = 0.007] were associated to a lower risk of P. vivax malaria. A total of 28 (14.1%) and 180 (25.3%) recurrences (at least a second clinical malaria episode) were reported in the HIV-positive and HIV-negative groups, respectively. After adjusting for sex and education, HIV-positive status was associated with a tendency towards protection from P. vivax malaria recurrences [ARR = 0.55 (0.27-1.10); P = 0.090]. HIV status was not associated with hospitalizations due to P. vivax malaria. CD4 + counts and viral load were not associated with recurrences of P. vivax malaria. No significant differences were found in the distribution of parasitemia between HIV-negative and HIV-positive P. vivax malaria patients. Our results suggest that HIV-positive status is a risk factor for vivax malaria infection, which represents an additional challenge that should be addressed during elimination efforts.

Trypanosoma cruzi Genomic Variability: Array Comparative Genomic Hybridization Analysis of Clone and Parental Strain.

Trypanosoma cruzi, the etiological agent of Chagas disease, exhibits extensive inter- and intrastrain genetic diversity. As we have previously described, there are some genetic differences between the parental G strain and its clone D11, which was isolated by the limiting dilution method and infection of cultured mammalian cells. Electrophoretic karyotyping and Southern blot hybridization of chromosomal bands with specific markers revealed chromosome length polymorphisms of small size with additional chromosomal bands in clone D11 and the maintenance of large syntenic groups. Both G strain and clone D11 belong to the T. cruzi lineage TcI. Here, we designed intraspecific array-based comparative genomic hybridization (aCGH) to identify chromosomal regions harboring copy-number variations between clone D11 and the G strain. DNA losses were more extensive than DNA gains in clone D11. Most alterations were flanked by repeated sequences from multigene families that could be involved in the duplication and deletion events. Several rearrangements were detected by chromoblot hybridization and confirmed by aCGH. We have integrated the information of genomic sequence data obtained by aCGH to the electrophoretic karyotype, allowing the reconstruction of possible recombination events that could have generated the karyotype of clone D11. These rearrangements may be explained by unequal crossing over between sister or homologous chromatids mediated by flanking repeated sequences and unequal homologous recombination via break-induced replication. The genomic changes detected by aCGH suggest the presence of a dynamic genome that responds to environmental stress by varying the number of gene copies and generating segmental aneuploidy.

Acute ischemic stroke and COVID-19 pandemic in Brazil: a comparative study of frequency and risk factors before and during SARS-CoV-2 era.

BACKGROUND: COVID-19 pandemic directly impacted the request for hospital care and medical assistance for several diseases worldwide, as occurred with acute ischemic stroke. The present study sought to compare the incidence and severity of acute ischemic stroke (AIS), in addition to sociodemographic, clinical, and radiological characteristics of patients hospitalized in the prepandemic (2018-2019) and pandemic (2020-2021) eras. METHODS: An incidence case-control, observational, and analytical research was carried out in the Stroke Unit of Hospital Governador Celso Ramos, Florianopolis, Santa Catarina, Brazil, including 171 patients admitted with acute ischemic stroke from April 2018 to April 2019 (prepandemic era) and 148 patients between January 2020 and January 2021 (during pandemic). RESULTS: The mean incidence of AIS hospital admissions was significantly lower in the pandemic period (CI 95%, 0.2 to 5.6; p = 0.04), being lower in the lockdown periods and when the incidence of new COVID-19 cases increased. Besides, referring to AIS severity, the mean areas of AIS were larger during the pandemic period (p < 0.01), especially in August, September, December, and January (p < 0.05). Sociodemographic and clinical variables did not show any difference between the two periods of the study. CONCLUSIONS: Hospital admissions for AIS decreased in the COVID-19 pandemic, mostly during months of higher incidences of new COVID-19 cases. When the incidence of admissions diminished, an increase in the severity of AIS was observed, characterized by larger areas. These findings might contribute to other similar referral centers in managing public policies related to stroke.

Diagnosis, risk factors analysis and first molecular characterization of Cryptosporidium spp. in horses from Rio de Janeiro, Brazil.

An analysis was made of the frequency of Cryptosporidium spp. in fecal samples from horses raised on farms in the Teresópolis city, state of Rio de Janeiro, Brazil, and the risk factors that favored this infection. Between 2019 and 2020, 314 samples of equine feces were collected, 287 of which came from English Thoroughbred horses and 27 from ponies. Information on the horses and their management were retrieved from a stud book and forms filled out by trainers. The fecal samples were subjected to macroscopic analysis, modified Sheather's and Lutz parasitological techniques, safranin staining, and to enzyme-linked immunosorbent assay (ELISA) for the detection of coproantigens. All the samples that tested positive by these techniques underwent partial sequence analysis of the 18S rRNA gene to characterize the protozoan species. Cryptosporidium spp. was identified in 35 (11.1%) of the samples, 34 from English Thoroughbred horses and one from a pony. Based on a logistic regression model, it was found that the presence of dogs and small ruminants on the farms, and drinking water from a spring, were significantly associated with the animals' infection by the protozoan (p < 0.05). Eight of the English Thoroughbred horse samples underwent molecular characterization, which revealed the presence of Cryptosporidium felis in one sample and Cryptosporidium parvum in seven. The seven samples containing C. parvum were subjected to gp60 gene analysis, based on which nucleotide sequences typical of the IIa family were identified, which are usually transmitted from animals to humans. In addition, the genotype IIaA15G2R1, which is considered to have the highest profile of zoonotic transmissibility, was identified in one Thoroughbred horse. This is the first study conducted in the state of Rio de Janeiro that molecularly characterized Cryptosporidium spp. in horses, and the first on the American continent to detect C. felis in the feces of these animals.

Narasin improves ewe milk yield efficiency and may affect performance of lambs

Adding ionophores to ruminant diets is a strategy to manipulate ruminal fermentation and improve milk yield. This study evaluates the effects of narasin supply to lactating ewes on dry matter intake (DMI), milk yield and composition, and performance of the lambs. Thirty lactating Santa Inês and Santa Inês × Dorper ewes fed a basal diet containing 50 % coastcross hay and 50 % concentrate were randomly assigned to two treatments: control (CON; without ionophores) or NAR (addition of 13 mg narasin kg-1 DM). From the 2nd to 10th week of lactation, DMI of ewes was determined, and once a week, their milk production and composition was measured over a 3-h interval. At the 10th week of lactation, lambs were weaned and their average daily gain (ADG) and starter DMI continued to be evaluated for two more weeks. Narasin supply did not affect weight and DMI of ewes. Ewes fed NAR had greater feed efficiency for milk production and displayed tendency for higher milk yield. Narasin supply reduced milk protein levels, but it did not affect other milk component levels. Ewes fed NAR had greater production of milk urea nitrogen and showed tendency for higher production of fat and total solids. Starter DMI of lambs was not affected by treatments; however, there was a tendency for greater weaning weight for NAR lambs. At the end of experiment, no differences were observed in the performance of lambs. The supply of 13 mg narasin kg-1 to lactating ewes improved milk yield efficiency and tended to increase the weaning weight of their lambs.(AU)