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BACKGROUND: Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) responsible for coronavirus disease 2019 (COVID-19) is most well-known for causing pulmonary injury, a significant proportion of patients experience hepatic dysfunction. The mechanism by which SARS-CoV2 causes liver injury is not fully understood. The goal of this study was to describe the hepatic pathology in a large cohort of deceased patients with COVID-19 as compared to a control group of deceased patients without COVID-19. METHODS: Consented autopsy cases at two institutions were searched for documentation of COVID-19 as a contributing cause of death. A group of consecutive consented autopsy cases during the same period, negative for SARS-CoV-2 infection, was used as a control group. The autopsy report and electronic medical records were reviewed for relevant clinicopathologic information. H&E-stained liver sections from both groups were examined for pertinent histologic features. Select cases underwent immunohistochemical staining for CD 68 and ACE2 and droplet digital polymerase chain reaction (ddPCR) assay for evaluation of SARS-CoV2 RNA. RESULTS: 48 COVID-19 positive patients (median age 73, M:F 3:1) and 40 COVID-19 negative control patients (median age 67.5, M:F 1.4:1) were included in the study. The COVID-19 positive group was significantly older and had a lower rate of alcoholism and malignancy, but there was no difference in other comorbidities. The COVID-19 positive group was more likely to have received steroids (75.6 % vs. 36.1 %, p < 0.001). Hepatic vascular changes were seen in a minority (10.6 %) of COVID-19 positive cases. When all patients were included, there were no significant histopathologic differences between groups, but when patients with chronic alcoholism were excluded, the COVID-19 positive group was significantly more likely to have steatosis (80.9 % vs. 50.0 %, p = 0.004) and lobular inflammation (45.7 % vs. 20.7 %, p = 0.03). Testing for viral RNA by ddPCR identified 2 of the 18 (11.1 %) COVID-19 positive cases to have SARS-CoV-2 RNA detected within the liver FFPE tissue. CONCLUSIONS: The most significant findings in the liver of COVID-19 positive patients were mild lobular inflammation and steatosis. The high rate of steroid therapy in this population may be a possible source of steatosis. Hepatic vascular alterations were only identified in a minority of patients and did not appear to play a predominant role in COVID-19 mediated hepatic injury. Low incidence of SARS-CoV-2 RNA positivity in liver tissue in our cohort suggests hepatic injury in the setting of COVID-19 may be secondary in nature.
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Alcoolismo , COVID-19 , Humanos , Idoso , SARS-CoV-2 , COVID-19/patologia , RNA Viral/análise , Alcoolismo/complicações , Alcoolismo/patologia , Fígado/patologia , Inflamação/patologia , Autopsia , Estudos de Casos e ControlesRESUMO
In a 3-month toxicity study in cynomolgus monkeys at a European contract laboratory, animals were infected with HAV, initially resulting in hepatic injury being incorrectly attributed to the test compound. Elevated serum ALT/AST/GLDH (5- to 10-fold) were noted in individual animals from all groups including controls, with no apparent dose, exposure, or time-related relationship. Liver histopathology revealed minimal to slight inflammatory cell accumulation in periportal zones of most animals, and minimal to slight hepatocyte degeneration/necrosis in 10/42 animals from all groups. As these findings were more pronounced in 6 drug-treated animals, including 2/6 in the low dose group, the draft report concluded: "treatment-related hepatotoxicity at all dose levels precluded determination of a NOAEL." However, the unusual pattern of hepatotoxicity suggested a factor other than drug exposure might have caused the hepatic effects. Therefore, snap-frozen liver samples were tested for hepatitis viruses using a PCR method. Tests for hepatitis B, C, and E virus were negative; however, 20/42 samples were positive for hepatitis A virus (HAV). Infection was strongly associated with increased serum ALT/GLDH, and/or hepatocyte degeneration/necrosis. Re-evaluation of the study in light of these data concluded that the hepatic injury was not drug-related. A subsequent 6-month toxicology study in HAV-vaccinated cynomolgus monkeys confirmed the absence of hepatotoxicity. Identification of HAV infection supported progression of the drug candidate into later clinical trials. Although rarely investigated, subclinical HAV infection has occasionally been reported in laboratory primates, including those used for toxicology studies and it may be more prevalent than the literature indicates.
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Hepatite A , Fígado , Macaca fascicularis , Animais , Masculino , Fígado/efeitos dos fármacos , Fígado/patologia , Feminino , Vírus da Hepatite A/efeitos dos fármacos , Doença Hepática Induzida por Substâncias e Drogas , Alanina Transaminase/sangue , Testes de ToxicidadeRESUMO
AIMS: The Schistosoma japonicum (S japonicum)-infected ApoE gene deficiency (ApoE-/- ) mice were used to determine effect of ApoE on hepatic immunopathology. METHODS: Murine activities and appetite, body weight, and ratio of liver weight to its body weight (Hepatic mass index, HMI) were observed. Worm load and liver egg burden were evaluated as the infection intensity. Number and size of liver egg granulomas and serum levels of alanine aminotransferase (ALT) were investigated. We analysed hepatic fibrosis by markers of fibrosis in tissue, detected hepatic Th17 and Treg frequency by flow cytometry, and measured hepatic expressions of RORγt, Foxp3, IL-17A and TGF-ß1 via qPCR. Lipid metabolism was determined by serum levels of cholesterol (TC) and triglyceride (TG) as well as hepatic Oil red O staining. RESULTS: In the infected ApoE-/- mice, the increased infection intensity aggravated the hepatic immunopathology (evidenced by increased HMI, elevated egg granulomas and increased ALT levels) and fibrosis (increased hepatic collagen deposition). ApoE deficiency resulted in significantly elevated ratio of hepatic Th17/Treg and higher serum levels of TC and TG, along with higher level of hepatic Oil red O staining. CONCLUSIONS: ApoE deficiency promotes hepatic pathology and fibrosis by exacerbating Th17/Treg imbalance and altering lipid metabolism in murine schistosomiasis japonica.
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Apolipoproteínas E/deficiência , Esquistossomose Japônica/imunologia , Esquistossomose Japônica/patologia , Linfócitos T Reguladores/patologia , Células Th17/patologia , Animais , Apolipoproteínas E/genética , Feminino , Metabolismo dos Lipídeos , Cirrose Hepática/parasitologia , Cirrose Hepática/patologia , Camundongos , Carga Parasitária , Schistosoma japonicum/patogenicidade , Esquistossomose Japônica/metabolismo , Esquistossomose Japônica/parasitologiaRESUMO
Histochemistry has an important, continuing role in the current assessment of hepatic biopsies and resection specimens. The evaluation of connective tissue elements in the liver can be accomplished with such methods as the Masson trichrome, Snook reticulin, Vierhoff van Gieson, orcein, and Victoria blue stains. The results contribute to the diagnosis of acute and chronic hepatitis, submassive necrosis, venous outflow obstruction, steatohepatitis, and cirrhosis. Fat stains done on frozen sections of liver tissue are routinely performed in the evaluation of donor liver allograft biopsies. Iron stains such as Perls' method and the Prussian blue technique contribute to the recognition of hemochromatosis and hemosiderosis. The rhodanine, orcein, and Timm stains for copper are used in the characterization of chronic cholestatic liver disease and Wilson's disease. Labeling of carbohydrate-based moieties in various disorders is accomplished with the digested and undigested periodic acid-Schiff method, and Congo red or crystal violet stains can be employed to detect amyloid deposition. Lastly, evaluations of the thickness of the cell plates and continuity of the reticulin framework, as seen with the Snook reticulin stain, can contribute to the diagnostic separation of benign from malignant hepatocellular neoplasms.
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Histocitoquímica , Hepatopatias/patologia , Fígado/patologia , Biópsia , Humanos , Valor Preditivo dos Testes , Prognóstico , Coloração e RotulagemRESUMO
Huntington's disease (HD), a congenital neurodegenerative disorder, extends its pathological damages beyond the nervous system. The systematic manifestation of HD has been extensively described in numerous studies, including dysfunction in peripheral organs and peripheral inflammation. Gut dysbiosis and the gut-liver-brain axis have garnered greater emphasis in neurodegenerative research, and increased plasma levels of pro-inflammatory cytokines have been identified in HD patients and various in vivo models, correlating with disease progression. In the present study, we investigated hepatic pathological markers in the liver of R6/2 mice which convey exon 1 of the human mutant huntingtin gene. Furthermore, we evaluated the impact of intravenously administered Mesenchymal Stromal Cells (MSCs) on the liver enzymes, changes in hepatic inflammatory markers, as well as brain pathology and behavioral deficits in R6/2 mice. Our results revealed altered enzyme expression and increased levels of inflammatory mediators in the liver of R6/2 mice, which were significantly attenuated in the MSC-treated R6/2 mice. Remarkably, neuronal pathology and altered motor activities in the MSC-treated R6/2 mice were significantly ameliorated, despite the absence of MSCs in the postmortem brain. Our data highlight the importance of hepatic pathological changes in HD, providing a potential therapeutic approach. Moreover, the data open new perspectives for the search in blood biomarkers correlating with liver pathology in HD.
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Doença de Huntington , Camundongos , Humanos , Animais , Doença de Huntington/metabolismo , Camundongos Transgênicos , Modelos Animais de Doenças , Encéfalo/metabolismo , Fígado/metabolismoRESUMO
Schistosomiasis is the second most debilitating neglected tropical disease in the world. Liver egg granuloma and fibrosis are the main damage of schistosomiasis. In this study, the role of allograft inflammatory factor-1 (AIF-1) in liver pathology and its regulation in immune responses were investigated in a transgenic mouse infected with Schistosoma japonicum. We found that AIF-1 overexpression reduced worm burden and decreased egg granuloma sizes and serum alanine aminotransferase levels, along with inhibited hepatic collagen deposition and serum hydroxyproline levels during S. japonicum infection. Moreover, AIF-1 overexpression resulted in an increased ratio of Th1/Th2, increased levels of IFN-γ and T-bet, and lower levels of GATA-3 in the spleen, accompanied by increased M1 percentages, decreased M2 percentages, and thus a higher ratio of M1/M2 in the peritoneal cavity and liver. AIF-1 induced CD68 and iNOS mRNA expression and protein levels of cytoplasmic p-P38 and nuclear NF-κB, along with enhanced levels of TNF-α and TGF-ß in macrophages in vitro. Moreover, the hepatic pathology had a negative correlation with Th1/Th2 and M1/M2 ratios in the infected mice. The findings reveal that the beneficial role of AIF-1 in alleviating hepatic damage is related to restoring type I/II immune balance in S. japonicum infection.
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Liver biopsy is essential for management in liver transplant patients with clinical features suspicious for acute cellular rejection (ACR). As more patients are transplanted for noninfectious indications, it has become increasingly common for them to receive treatment for presumed ACR before biopsy. The effect of pretreatment on the classic histologic triad of ACR's mixed portal inflammation, endothelialitis, and bile duct damage is not well described. Here we report a retrospective study of 70 liver transplant biopsies performed on 53 patients for suspected ACR between 2018 and 2021. Thirty-seven biopsies had a clinical diagnosis of ACR after biopsy. Pretreatment with steroids, antithymocyte globulin, or other increased immunosuppression was given before biopsy in 17 of 37 cases; 20 not-pretreated cases acted as controls. A representative hematoxylin and eosin-stained slide from each biopsy was reviewed independently in a blinded fashion by 3 hepatic pathologists, graded according to the Banff system, assigned a Rejection Activity Index (RAI), and assessed for other histologic features. We found that pretreated biopsies had significantly less portal inflammation (P < .001), less endothelialitis (P < .001), lower RAI (P < .001), and less prominent eosinophils (P = .048) compared to not-pretreated biopsies. There was no significant difference for the other examined variables, including bile duct inflammation/damage (P = .32). Our findings suggest that portal inflammation and endothelialitis become less prominent with pretreatment, whereas bile duct inflammation/damage may take longer to resolve. When evaluating biopsies for suspected ACR, the finding of bile duct inflammation/damage should raise the possibility of partially treated ACR, even in the absence of endothelialitis and portal inflammation.
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Rejeição de Enxerto , Fígado , Humanos , Estudos Retrospectivos , Fígado/patologia , Biópsia , Rejeição de Enxerto/patologia , Inflamação/patologia , AloenxertosRESUMO
Toxoplasma gondii (T. gondii), one of the most important Apicomplexan protozoa, causes toxoplasmosis in human throughout the world. Galectin (Gal)-9 triggers a series of immune events via binding to its receptors, including T cell immunoglobulin and mucin-containing molecule 3, CD137, CD44, and protein disulfide isomerase. To examine the regulatory role of galectin-receptor interactions in anti-toxoplasmic activities, C57BL/6 mice were infected with T. gondii RH strain and intraperitoneally injected with alpha (α)-lactose to block the interactions of galectins and their receptors. Heatmaps showed upregulated values for Gal-9 and CD137 in the livers of T. gondii-infected mice and T. gondii-infected mice treated with α-lactose. Compared with T. gondii-infected mice, T. gondii-infected mice treated with α-lactose showed significantly increased survival rate, decreased tissue parasite burden, attenuated liver histopathology, increased mRNA expression levels of CD137, IFNγ, IL-4, and IL-10 in the liver, and increased Gal-9 mRNA expression level in the spleen. Correlation analysis showed that significant positive correlations existed between the mRNA expression levels of Gal-9 and CD137, Gal-9 and IFNγ, as well as between CD137 and IFNγ in the liver and spleen of T. gondii-infected mice; between CD137 and IFNγ in the liver of T. gondii-infected mice treated with α-lactose. In addition, blockage of galectin-receptor interactions showed enhanced M2 macrophage polarization in the liver of T. gondii-infected mice. Our data indicate that Gal-9-CD137 interaction may play an important role in T. gondii proliferation and liver inflammation in mice during acute T. gondii infection, through regulating T cell and macrophage immune responses.
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Galectinas , Fígado , Toxoplasma , Toxoplasmose , Animais , Modelos Animais de Doenças , Galectinas/antagonistas & inibidores , Galectinas/metabolismo , Lactose/metabolismo , Fígado/metabolismo , Fígado/patologia , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/metabolismo , Toxoplasmose/complicaçõesRESUMO
Hepatic drug metabolizing enzymes (DMEs) markedly affect drug pharmacokinetics. Because liver diseases may alter enzymatic function and in turn drug handling and clinical efficacy, we investigated DMEs expression in dependence on liver pathology and liver failure state. In 5 liver pathologies (hepatitis C, alcoholic liver disease, autoimmune hepatitis, primary biliary cholangitis and primary sclerosing cholangitis) and for the first time stratified according to the Child-Pugh score, 10 CYPs (CYP1A1, CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4 and CYP3A5) and 4 UGTs (UGT1A1, UGT1A3, UGT2B7 and UGT2B) enzymes were quantified for protein abundance (LC-MS/MS) and gene expression (qRT-PCR). CYP2E1 was the most vulnerable enzyme, and its protein levels were significantly reduced just in Child-Pugh class A livers. The protein abundance of CYP1A1, CYP2B6, CYP2C19, CYP2D6 as well as UGT1A1, UGT1A3 and UGT2B15 was relatively stable in the course of progression of liver function deterioration. Alcoholic liver disease and primary biliary cholangitis were involved in the most prominent changes in the protein abundances, with downregulation of 6 (CYP1A2, CYP2C8, CYP2D6, CYP2E1, CYP3A4, UGT2B7) and 5 (CYP1A1, CYP2B6, CYP2C8, CYP2E1, CYP3A4) significantly downregulated enzymes, respectively. The results of the study demonstrate that DMEs protein abundance is affected both by the type of liver pathology as well as functional state of the organ.
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BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) also referred as metabolic as metabolic (dysfunction) associated fatty liver disease. Type 2 diabetes mellitus (T2DM) is a major cause in progression of NAFLD and non-alcoholic steatohepatitis (NASH). The aim of the present study is to assess the activity of liver enzymes in T2DM in North Indian population. METHOD: This was a cross-sectional descriptive study clinic-based study in patients with T2DM. A total of 612 participants (226 healthy controls and 386 T2DM) were recruited. Body mass index (BMI), activity of liver enzymes including alanine and aspartate aminotransferase (ALT, AST) along with alkaline phosphatase (ALP) was measured. Fasting blood glucose (FBG) and glycosylated hemoglobin (HbA1c) along with total protein (TP) and albumin were also measured. Quantitative variables were expressed as mean ± SD, while qualitative variables as frequencies (%). Pearson/Spearman correlation test, unpaired t-test, Chi-squared test was used to assess the correlation, association and significant differences between study groups respectively. A P-value of < .05 was set as statistically significant. The Statistical Package for Social Sciences (SPSS) ® Statistics, version 23 (IBM SPSS Statistics, Armonk, NY) was used to for analysis of data. RESULTS: The study was conducted on 386 T2DM patients, and out of 386 patients, 139 (36.01%) were male (P < .000) and 247 (63.98%) were female. The mean age of the T2DM patients was 46.4 ± 13.6 years, while healthy individuals have mean age of 39.2 ± 12.0 years (P < .000). It was observed that the activity of AST in T2DM is comparable with the healthy persons (P = .060). While the level of ALT, total bilirubin and ALP in T2DM is significantly higher compared to healthy control (P < .000). On average, 62.53% of T2DM subjects and 32% of participants of healthy subjects had abnormal liver enzymes activity. CONCLUSION: The present study has revealed widely co-existent derangements in liver function tests (LFTs) in the diabetic population of North India. A detailed workup in such patients may be helpful in timely diagnosis and treatment. Moreover, early detection and management of abnormal liver parameters in T2DM would help minimize liver-related morbidity and mortality.
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A high prevalence of hepatic pathology (in 17 of 19 cases) was reported in post-mortem (PM) examinations of COVID-19 patients, undertaken between March 2020 and February 2021 by a single autopsy pathologist in two English Coronial jurisdictions. The patients in our cohort demonstrated high levels of recognised COVID-19 risk factors, including hypertension (8/16, 50%), type 2 diabetes mellitus (8/16, 50%) and evidence of arteriopathy 6/16 (38%). Hepatic abnormalities included steatosis (12/19; 63%), moderate to severe venous congestion (5/19; 26%) and cirrhosis (4/19; 21%). A subsequent literature review indicated a significantly increased prevalence of steatosis (49%), venous congestion (34%) and cirrhosis (9.3%) in COVID-19 PM cases, compared with a pre-pandemic PM cohort (33%, 16%, and 2.6%, respectively), likely reflecting an increased mortality risk in SARS-CoV-2 infection for patients with pre-existing liver disease. To corroborate this observation, we retrospectively analysed the admission liver function test (LFT) results of 276 consecutive, anonymised COVID-19 hospital patients in our centre, for whom outcome data were available. Of these patients, 236 (85.5%) had significantly reduced albumin levels at the time of admission to hospital, which was likely indicative of pre-existing chronic liver or renal disease. There was a strong correlation between patient outcome (length of hospital admission or death) and abnormal albumin at the time of hospital admission (p = 0.000012). We discuss potential mechanisms by which our observations of hepatic dysfunction are linked to a risk of COVID-19 mortality, speculating on the importance of recently identified anti-interferon antibodies.
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BACKGROUND: Whether achieving sustained virological response (SVR) in patients with hepatitis C attains complete elimination of hepatitis C virus (HCV) is unknown, because occult HCV infection (OCI), defined as the detection of HCV-RNA in hepatocytes or peripheral blood mononuclear cells (PBMC) in absence of serum HCV-RNA, may occur. We thus investigated the prevalence and clinical relevance of OCI. METHODS: Subjects from three hospitals who had achieved serum HCV clearance, including 60 of Direct-acting antiviral agents (DAAs) induced SVR, 50 of pegylated interferon plus ribavirin (PR) induced SVR, and 30 of spontaneous resolution, were subjected to detect HCV-RNA in liver by robust RNAscope assay and PBMC by qPCR. Paired liver biopsies at baseline and at SVR24 were analyzed. RESULTS: OCI was detected in 16 of 140 subjects (11.4%), with 15.0% in DAA-based group, 10.0% in PR group and 6.7% in spontaneously resolved group. In DAA-based subgroups, the incidence of OCI was gradually increased in group of solely DAA(s) therapy, combining DAA and PR therapy and combining DAA and ribavirin therapy. OCI is more frequent in patients with genotype 3. No correlation between baseline viral load, interleukin-28B genotype, baseline transaminases, post-SVR transaminases and OCI were found. However, OCI was significantly linked with severity of fibrosis and active inflammation at post-SVR, even considering basal fibrosis status. In addition, both the magnitude and the frequency of fibrosis regression were lower in patients with OCI than in those without OCI. In the multivariate analysis, PR therapy was identified an independent negative prognostic factor for both hepatic inflammation (Pâ¯=â¯.022) and fibrosis regression (Pâ¯=â¯.015). Importantly, we found HCV relapse in one of the OCI patients at 48â¯weeks after the end of PR treatment. CONCLUSIONS: HCV-RNA can persist in hepatocytes and/or PBMC in a certain of patients who achieved spontaneous or treatment-induced HCV RNA clearance from serum and associated with persistent histological abnormality. Our findings provide new insights into cure of HCV and could influence the following-up scenario after SVR.
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Hepacivirus/fisiologia , Hepatite C/patologia , Hepatite C/virologia , Fígado/patologia , Fígado/virologia , Carga Viral , Adulto , Idoso , Antivirais/farmacologia , Antivirais/uso terapêutico , Biópsia , Feminino , Hepatite C/tratamento farmacológico , Humanos , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , RNA Viral , Resposta Viral Sustentada , Resultado do Tratamento , Adulto JovemRESUMO
Greater than two-thirds of all Hepatitis C virus (HCV) infections are chronic, leading to extrahepatic changes in the body. The objective of this article was to describe various musculoskeletal findings that can be elicited during an osteopathic structural exam in the setting of liver dysfunction along with an overview of hepatic viscerosomatics and Chapman's points. Osteopathic medicine is a branch of modern medicine that utilizes hands-on diagnosis and treatment through musculoskeletal manifestations in addition to the standard allopathic practices. Herein, we presented a case of untreated chronic HCV infection, complicated by polysubstance abuse, with positive findings on osteopathic physical exam consistent with hepatic pathology.
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Organic arsenic diphenylarsinic acid (DPAA[V]) accumulates at high concentrations in the liver of primates after its subchronic administration. However, no studies on the hepatic effects of organic arsenic compounds, including DPAA(V), on primates have been reported to date. To clarify the toxicokinetics of DPAA(V) in the liver of primates, hepatic tissue specimens were collected from cynomolgus monkeys (n = 32) at 5, 29, 170, and 339 days after repeated administration of DPAA(V) for 28 days. Four histopathological changes in the specimens were observed and pathologically evaluated. Atypical ductular proliferation was found in the DPAA(V)-exposed liver throughout the period. Inflammatory cell infiltration in Glisson's capsules and lipid droplets were seen at earlier periods after administration. Conversely, inflammatory cell infiltration in liver lobules was seen later after administration. In this experiment, we did not confirm the hepatic dysfunction of DPAA(V)-exposed monkeys by blood chemistry tests. To compensate for this, we further investigated the blood from a patient who exhibited several neurological symptoms after DPAA(V) exposure. Her blood chemistry test values for aspartate transaminase, alanine transaminase, and lactate dehydrogenase were elevated, suggesting that her liver may have been damaged by DPAA(V) exposure. Together, these findings suggest that the accumulation of DPAA(V) may induce differential histopathological changes in primate hepatocytes, resulting in decreased liver function. This is the first report to investigate the liver of primates pathologically after exposure to organic arsenic DPAA(V). Our findings will help expand our knowledge regarding the effect of DPAA(V) on the liver of primates.
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Arsenicais/efeitos adversos , Fígado/efeitos dos fármacos , Fígado/patologia , Alanina Transaminase/sangue , Animais , Arsenicais/administração & dosagem , Arsenicais/farmacocinética , Aspartato Aminotransferases/sangue , Biomarcadores/sangue , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Criança , Feminino , Humanos , Gotículas Lipídicas/metabolismo , Fígado/metabolismo , Hepatopatias/diagnóstico , Macaca fascicularis , Fatores de TempoRESUMO
Major advances have been made in identifying potential vaccine molecules for the control of fasciolosis in livestock but we have yet to reach the level of efficacy required for commercialisation. The pathogenesis of fasciolosis is associated with liver damage that is inflicted by migrating and feeding immature flukes as well as host inflammatory immune responses to parasite-secreted molecules and tissue damage alarm signals. Immune suppression/modulation by the parasites prevents the development of protective immune responses as evidenced by the lack of immunity observed in naturally and experimentally infected animals. In our opinion, future efforts need to focus on understanding how parasites invade and penetrate the tissues of their hosts and how they potentiate and control the ensuing immune responses, particularly in the first days of infection. Emerging 'omics' data employed in an unbiased approach are helping us understand liver fluke biology and, in parallel with new immunological data, to identify molecules that are essential to parasite development and accessible to vaccine-induced immune responses.
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Fasciolíase/prevenção & controle , Vacinas/imunologia , Animais , Fasciola hepatica/imunologia , Fasciolíase/imunologia , Fasciolíase/patologia , Proteínas de Helminto/imunologia , Ruminantes/imunologia , Ruminantes/parasitologia , Zoonoses/imunologia , Zoonoses/patologia , Zoonoses/prevenção & controleRESUMO
Foi feita uma avaliação histopatológica de 702fragmentos de tecido hepático obtidos pela antiga SUCAM no sul do Estado da Bahia no período que vai de 1981 a 1991. Apenas em 17,7% dos casos ofígadofoi considerado h is to logicamente normal. Mais de um terço dos casos exibia intensa esteatose, provavelmente causada por desnutrição grave afetando crianças nos primeiros anos de vida. Nos demais, as alterações indicativas de fbrose, tuberculose, esquistossomose e hepatites apareceram como processos importantes pela sua gravidade e frequência. Além disso, uma variada gama de processos patológicos hepáticos pôde também ser reconhecida. Sugere-se que o material de viscerotomia merece um exame histológico mais detalhado, pois desta maneirapoderáfomecer dados de valorpar a a identificação de processos patológicos que afetam populações vivendo em áreas remotas do nosso país.