Rodolfo Paredes

Introduction/Objective: Chronic cholestatic liver disease (CCLD) is characterized by impaired bile production and excretion due to its inflammatory nature and potential progression to biliary cirrhosis. Murine models mimic cholestatic-type human liver diseases, such as the 3,5- diethoxycarbonyl-1,4-dihydrocholidine (DDC) model. Nonetheless, the timeline for liver regeneration following cessation of the DDC diet remains unclear. This study aimed to evaluate the duration of hepatic alterations after cessation of the DDC diet. Methods: C57BL/6J male mice (16-17 weeks old) were randomly assigned to Control (standard diet) and CCLD (DDC-supplemented diet) groups. After six weeks of diet exposure, the DDC group transitioned to a standard diet. Liver parameters were evaluated at 3-, 18-, and 36-days post-diet cessation. Analysis included liver damage and weight, histopathology, and biochemical markers. Results: Liver damage remained elevated until day 36, whereas liver weight remained elevated until day 18. Histological analysis confirmed that bile duct obstruction and fibrosis scores in the DDC group remained significantly higher than in controls up to 36 days after the DDC diet. Serum bile acid levels remained elevated for up to 18 days, while GGT levels did not differ across time points. AST levels were markedly increased at 3 days, whereas ALT levels remained elevated at 3 and 18 days. Discussion/Conclusion: Total cholesterol and triglyceride levels increased until day 18, highlighting changes in lipid metabolism. Our study demonstrates hepatic effects in the DDCinduced CCLD model, with alterations persisting beyond cessation of hepatotoxin exposure. These findings show the temporal dynamics of CCLD after diet cessation through different liver parameters.

Chagas disease, caused by Trypanosoma cruzi, is maintained in nature by complex interactions among wild vertebrates and triatomine insect vectors, yet the role of many introduced hosts remains poorly resolved. Here, we assessed natural T. cruzi infection in wild European rabbits (Oryctolagus cuniculus) from central Chile, where introduced rabbits overlap ecologically with the sylvatic vector Mepraia spinolai. Eight free-ranging rabbits captured in Las Chinchillas National Reserve were evaluated using an integrative diagnostic approach combining xenodiagnosis with laboratory-reared, parasite-free M. spinolai nymphs, real-time polymerase chain reaction targeting T. cruzi satellite DNA in blood and 12–14 organs per animal, and histopathology with immunohistochemistry (anti-cruzipain) to identify tissue parasite forms. Blood molecular detection was positive in seven out of eight rabbits, while xenodiagnosis detected viable parasites in two out of seven evaluated individuals. Organ molecular screening detected T. cruzi DNA in at least one organ in all rabbits, with frequent positivity in the diaphragm, reproductive tissues, spleen, and kidney. Histopathology identified parasite forms in four out of eight animals, and immunohistochemistry confirmed hepatic amastigotes in one case. These findings provide multi-method evidence of natural infection in the sampled individuals, including evidence of parasite viability in some individuals, suggesting potential epidemiological relevance within this ecological context and possible utility for surveillance in Chilean sylvatic transmission settings.

Cystic echinococcosis (CE) is a globally distributed zoonotic disease caused by Echinococcus granulosus sensu lato, forming fluid-filled cysts in humans and livestock. These cysts consist of three layers: an inner germinal layer and a middle laminar layer of parasitic origin, and an outer adventitial layer derived from the host’s immune response. The adventitial layer typically contains immune cells such as T and B lymphocytes, macrophages, and other inflammatory cells. Notably, differences have been reported in the cellular composition of this layer depending on the host species. However, the variation in calprotectin expression—a protein specific to phagocytes—between cattle and sheep CE cysts has not been previously described. This study assessed calprotectin expression using immunohistochemistry with anti-calprotectin antibodies on adventitial tissue sections from cattle and sheep CE cysts. The results showed a significantly higher calprotectin expression in the adventitial layer of cattle cysts compared to sheep. This difference was not associated with the fertility or anatomical location of the cysts. These findings suggest that the host species influences the level of calprotectin expression in the adventitial layer, contributing to our understanding of host-specific immune responses in CE.

Cystic Echinococcosis (CE) is a zoonotic disease caused by Echinococcus granulosus sensu lato, forming cysts in ruminants and humans with major health and economic impacts. The immune response to CE cysts is complex, with fertility linked to the host’s inflammatory reaction. This study examines γδ T cell distribution and role within the adventitial layer of non-fertile CE cysts in cattle, including cases co-infected with the trematode Fasciola hepatica (FH), a known immune response modulator. Using immunohistochemistry and double immunofluorescence, we observed γδ T cells dispersed in the adventitial layer, enriched in inflammatory zones. Co-infected cases (CE + FH+) showed a reduced γδ T cell proportion among CD3+ T cells compared to non-coinfected cases, suggesting an immunoregulatory effect of FH. Our findings align with prior studies showing γδ T cell recruitment in granulomatous diseases in ruminants but reveal that co-infection alters this response. This study provides the first detailed characterization of γδ T cells in cattle CE cysts, emphasizing their potential role in granulomatous immune responses. It highlights the need for further research into mechanisms influencing CE cyst fertility and immune modulation in helminth co-infections, advancing our understanding of host-pathogen interactions and informing disease management strategies.

Urinary incontinence is a widespread issue, particularly among women, with effective treatments remaining elusive. The pig, and especially the female pig, stands as a promising animal model for the study of this condition, due to its anatomical similarities to humans. The aim of this study was to explore the largely uncharted muscular structure of the female pig urethra, linking urethral muscle dysfunction to incontinence. We examined histological sections from the urethras of six sows using Hematoxylin-Eosin and Masson’s trichrome staining for morphometric analysis. The statistical significance of cellular disposition was determined through analysis of variance (ANOVA), followed by a Tukey post hoc test to elucidate specific inter-group differences. Our analysis revealed segment-specific epithelial differences, including variations in cell layers, sparse acinar glands, rich vasculature, and distinct muscle fibers with diverse regional distributions. Notably, significant differences in muscular area and tissue distribution were identified between the proximal, middle, and distal segments of the urethra (p < 0.001). The observed anatomical variations, along with the cellular similarities between pigs and humans, establish the female pig as a crucial translational model for advancing urological research. Specifically, these findings provide a foundation for the development of innovative therapeutic strategies and surgical techniques that can be directly applied to improve outcomes in human urological conditions.

Cystic echinococcosis (CE) is a zoonotic disease caused by the tapeworm Echinococcus granulosus sensu lato (s.l). In the intermediate host, this disease is characterized by the growth of cysts in viscera such as liver and lungs, inside of which the parasite develops to the next infective stage known as protoscoleces. There are records that the infected viscera affect the development and morphology of E. granulosus s.l. protoscolex in hosts such as buffalo or humans. However, the molecular mechanisms that drive these differences remains unknown. Weighted gene co-expression network analysis (WGCNA) using a set of RNAseq data obtained from E. granulosus sensu stricto (s.s.) protoscoleces found in liver and lung cysts reveals 34 modules in protoscoleces of liver origin, of which 12 have differential co-expression from protoscoleces of lung origin. Three of these twelve modules contain hub genes related to immune evasion: tegument antigen, tegumental protein, ubiquitin hydrolase isozyme L3, COP9 signalosome complex subunit 3, tetraspanin CD9 antigen, and the methyl-CpG-binding protein Mbd2. Also, two of the twelve modules contain only hypothetical proteins with unknown orthology, which means that there are a group of unknown function proteins co-expressed inside the protoscolex of liver CE cyst origin. This is the first evidence of gene expression differences in protoscoleces from CE cysts found in different viscera, with co-expression networks that are exclusive to protoscoleces from liver CE cyst samples. This should be considered in the control strategies of CE, as intermediate hosts can harbor CE cysts in liver, lungs, or both organs simultaneously.

Salmonella enterica is an important foodborne pathogen. Commercial poultry are the main reservoirs of Salmonella enterica, leading to the contamination of food and outbreaks in humans. The vaccination of chickens is one of the most important strategies to reduce the number of Salmonella in poultry farms. Unfortunately, commercial vaccines have not been fully effective in controlling the spread and do not contain all the Salmonella serovars that circulate on farms. In this study, we evaluate a new, cochleate-based, trivalent injectable vaccine against S. Enteritidis, S. Typhimurium and S. Infantis, describing the vaccine security, capacity to induce specific anti-Salmonella serovar IgY and the gene expression of immune markers related to CD4 and CD8 T-cell-mediated immunity. Efficacy was evaluated through oral challenges performed separately for each Salmonella serotype. The efficacy and safety of the trivalent vaccine was proven under controlled conditions. The vaccine has no local or systemic reactions or adverse effects on poultry performance related to the vaccine. The vaccine provided significantly increased serum IgY titer levels, significantly reduced Salmonella CFU/g present in the cecum and an increased CD4+/CD8+ ratio in vaccinated animals when challenged with S. Infantis, S. Enteritidis and S. Typhimurium. These results indicate that this new trivalent vaccine does not generate adverse effects in poultry and produces an increase in neutralizing antibodies against the three Salmonella serovars.

Cystic Echinococcosis (CE), a zoonotic parasitic disease, is caused by the cestode Echinococcus granulosus sensu lato. CE inflicts severe damage in cattle, sheep, and human hosts worldwide. Fertile CE cysts are characterized by the presence of viable protoscoleces. These parasite forms are studied with minimal contamination with host molecules. Hosts, cattle and sheep, show differences in their CE cyst fertility. The effect of the host in protoscolex transcriptome is not known. We genotyped and performed transcriptomic analysis on sheep protoscoleces obtained from liver and lung CE cysts. The transcriptomic data of Echinococcus granulosus sensu stricto protoscoleces from 6 lung CE cysts and 6 liver CE cysts were Collected. For host comparison analysis, 4 raw data files belonging to Echinococcus granulosus sensu stricto protoscoleces from cattle liver CE cysts were obtained from the NCBI SRA database. Principal component and differential expression analysis did not reveal any statistical differences between protoscoleces obtained from liver or lung cysts, either within the same sheep or different sheep hosts. Conversely, there are significant differences between cattle and sheep protoscolex samples. We found differential expression of immune-related genes. In cattle, 7 genes were upregulated in protoscoleces from liver cysts. In sheep, 3 genes were upregulated in protoscoleces from liver and lung CE cysts. Noteworthy, are the differential expression of antigen B, tegument antigen, and arginase-2 in samples obtained from sheep CE cysts, and basigin in samples from cattle CE cysts. These findings suggest that the host species is an important factor involved in the differential expression of immune related genes, which in turn is possibly related to the fertility of Echinococcus granulosus sensu stricto cysts.

Cystic echinococcosis is a zoonotic disease caused by the metacestode of Echinococcus granulosus sensu lato. The disease is characterized by the development of cystic structures inside viscera of the intermediate host, mainly liver and lungs. These cysts are formed by three layers: germinal, laminated, and adventitial layer, the latter being the local host immune response. Metacestodes that develop protoscoleces, the infective stage to the definitive host, are termed fertile, whereas cysts that do not produce protoscoleces are termed non-fertile. Sheep usually harbor fertile cysts while cattle usually harbor non-fertile cysts. Adventitial layers with fibrotic resolution are associated to fertile cysts, whereas a granulomatous reaction is associated with non-fertile cysts. The aim of this study was to analyze cellular distribution in the adventitial layer of fertile and non-fertile E. granulosus sensu stricto cysts found in liver and lungs of cattle and sheep. A total of 418 cysts were analyzed, 203 from cattle (8 fertile and 195 non-fertile) and 215 from sheep (64 fertile and 151 non-fertile). Fertile cysts from cattle showed mixed patterns of response, with fibrotic resolution and presence of granulomatous response in direct contact with the laminated layer, while sheep fertile cysts always displayed fibrotic resolution next to the laminated layer. Cattle non-fertile cysts display a granulomatous reaction in direct contact with the laminated layer, whereas sheep non-fertile cysts display a granulomatous reaction, but in direct contact with the fibrotic resolution. This shows that cattle and sheep cystic echinococcosis cysts have distinct local immune response patterns, which are associated to metacestode fertility.