Centrilobular Areas Research Articles

Histopathological alterations caused by Klebsiella pneumoniae infection in rabbits and the preventive effects of whole sonicated killed antigen and Albizia lebbeck extract

Background. The purpose of this study is to estimate the protective capability of ethanolic Albizia lebbeck leaf extract against Klebsiella pneumoniae contagion in rabbits. Methods. The animals gathered into three groups each group contain eight albino rabbits were received the following: subcutaneously group one was received Killed Whole Cell Sonicated Antigen-Klebsiella pneumoniae (KWCSAg-KP); group two was orally received ethanolic Albizia lebbeck leaf extract and KWCSAg-KP subcutaneously; group three was quit as control group was given PBS subcutaneously. The rabbit groups were orally challenged by 1.5 × 108 CFU/ml Klebsiella pneumoniae then the rabbit were immolated ten days post-challenge for pathological changes. Spleen, liver, intestine and kidney were examined for histopathological alterations. Intestine, liver, kidney and spleen were examined for pathological changes. Results. The results revealed that the 2nd group had the least histopathological alterations with moderate infiltration of inflammatory cells in addition to no any abnormality detected in the kidney as well as the liver. The KWCSAg-KP group revealed sloughing with mild superficial inflammation in the lamina propria and mild vacuolation of the hepatocytes in the centrilobular area in addition to moderate white pulp hyperplasia in the spleen. The control group showed sever changes of inflammation, vacuolation, intestinal hemorrhage and congestion of the hepatic veins as well as hemosiderosis of the red pulp in the spleen. Conclusion. Albizia lebbeck leaf extract revealed to give an appropriate protection against inflammation as well as damage of virulent Klebsiella pneumoniae contagion in comparison to both of KWCSAg-KP and control groups.

Copper hepatopathies in Australian dogs.

To evaluate hepatopathies in Australian dogs according to the World Small Animal Veterinary Association (WSAVA) guidelines. Specifically, to describe the prevalence and survival of dogs with copper-associated hepatopathy. Medical records from the Small Animal Specialist Hospital were reviewed to identify dogs with liver disease and liver biopsy between November 2008 and November 2021. Liver histopathology reports were reviewed with a board-certified veterinary pathologist and classified according to the WSAVA guidelines. Histopathology reports and clinical records were reviewed to ascertain the most important histological process for statistical analysis. Copper-associated hepatopathy was defined as (i) histological evidence of copper accumulation in centrilobular areas (Zone 3) associated with hepatocyte necrosis, inflammation with copper-laden macrophages and chronic hepatitis (ii) histochemical copper staining showing hepatocyte copper accumulation in the centrilobular areas and iii) hepatic copper measurement with concentrations greater than 600 μg/g dry weight of liver. Dogs with primary inflammatory parenchymal disease included dogs with copper-associated hepatopathy, idiopathic chronic hepatitis, non-specific reactive hepatitis, chronic bacterial hepatitis and immune-mediated chronic hepatitis. Descriptive statistics were performed for all dogs. Age, weight and clinicopathologic data were compared between dogs with copper-associated hepatopathy and dogs with other causes of chronic primary inflammatory parenchymal liver disease (Kruskal-Wallis test). Survival times were calculated and compared (Kaplan-Meier curves and log rank test) between dogs with copper-associated hepatopathy and dogs with other chronic primary inflammatory parenchymal liver diseases. Breed was evaluated to determine the breed most commonly affected with copper-associated hepatopathy and identify any breed in which this disease has not previously been described. Sixty-seven (43 female, 24 male) dogs with a median age of 7.8 years (quartile [Q] Q1-Q3 4.5-9.6 years) were included. Thirteen dogs had copper-associated hepatopathy, eight dogs had idiopathic chronic hepatitis, eight dogs had non-specific reactive hepatitis, seven dogs had disorders associated with portal hypertension, five dogs had chronic bacterial hepatitis and four dogs had immune-mediated chronic hepatitis. Compared with dogs with other causes of chronic primary inflammatory parenchymal liver disease, dogs with copper-associated hepatopathy tended to be younger (6.73 vs. 8.01 years, P = 0.057) and heavier (19.8 vs. 9.6 kg, P = 0.052) than dogs with other causes of primary chronic inflammatory parenchymal diseases. There was no statistically significant difference when ALT (P = 0.30), ALP (P = 0.18) and total bilirubin (P = 0.13) were compared between the two groups. The median survival time for all dogs after liver biopsy was 2010 days (CI 1321 days - not reached). There was no significant difference in survival between dogs with copper-associated hepatopathy and dogs with other causes of chronic primary inflammatory parenchymal liver disease (P = 0.5). Copper-associated hepatopathy was common among Australian dogs with chronic hepatopathies, occurring in younger and heavier dogs than other causes of primary inflammatory parenchymal liver disease. Clinical pathology is not useful for differentiating between copper-associated hepatopathy and other causes of chronic primary inflammatory parenchymal liver disease. When copper-associated hepatopathy is treated, the prognosis can be good. This is the first report of copper-associated hepatopathy in Australian Cavalier King Charles Spaniels.

ARRB1 downregulates acetaminophen-induced hepatoxicity through binding to p-eIF2α to inhibit ER stress signaling.

Acetaminophen (APAP) stands as the predominant contributor to drug-induced liver injury (DILI), and limited options are available. β-Arrestin1 (ARRB1) is involved in numerous liver diseases. However, the role of ARRB1 in APAP-induced liver injury remained uncertain. Wild-type (WT) and ARRB1 knockout (KO) mice were injected with APAP and sacrificed at the indicated times. The histological changes, inflammation, endoplasmic reticulum (ER) stress, and apoptosis were then evaluated. Hepatic cell lines AML-12 and primary hepatocytes were used for in vitro analyses. Systemic ARRB1-KO mice were susceptible to APAP-induced hepatotoxicity, as indicated by larger areas of centrilobular necrosis area and higher levels of ALT, AST, and inflammation level. Moreover, ARRB1-KO mice exhibited increased ER stress (indicated by phosphorylated α subunit of eukaryotic initiation factor 2 (p-eIF2α)-activating transcription factor 4 (ATF4)-CCAAT-enhancer-binding protein homologous protein (CHOP)) and apoptosis (indicated by cleaved caspase 3). Further rescue experiments demonstrated that the induction of apoptosis was partially mediated by ER stress. Overexpression of ARRB1 alleviated APAP-induced ER stress and apoptosis. Moreover, co-IP analysis revealed that ARRB1 directly bound to p-eIF2α and eIF2α. ARRB1 protected against APAP-induced hepatoxicity through targeting ER stress and apoptosis. ARRB1 is a prospective target for treating APAP-induced DILI.

OUTCOME OF AZITHROMYCIN AND MONOSODIUM GLUTAMATE ON HISTOLOGIC AND BIOCHEMICAL ALTERATIONS IN RATS’ LIVER

Background: Monosodium glutamate (MSG), a commonly used flavouring, mediated hepatotoxic and pro-inflammatory responses. Azithromycin (AZT), an antibiotic with anti-inflammatory activity, may be co-consumed with MSG to present unknown outcomes on the liver, a major organ for the detoxification of xenobiotics. Aim: This study evaluated the effect of AZT and MSG on histologic and biochemical changes in rats’ liver. Methods: Thirty rats in five groups were for seven successive days orally exposed to groups 1, (distilled water 1 mL Kg−1), 2, (MSG 8000 mg/kg), 3, overdose AZT, OAZT (AZT 412.5 mg Kg−1), 4, therapeutic concentration AZT, TAZT, (AZT 82.5mg Kg−1), and 5, (TAZT 82.5 mg Kg−1 + MSG 8000 mg Kg−1). Liver function markers in therats’ serum and liver tissue, and changes in the liver histologic were assessed by acceptable protocols. The mean of numeric data were tested for significance at p value less than 0.05 by analysis of variance (ANOVA). Results: MSG treatment significantly (p<0.05) increased hepatic and serum alanine aminotransferase activity (ALT), aspartate aminotransferase activity (AST), alkaline phosphatase activity (ALP), total bilirubin concentration (T-BIL), and direct bilirubin concentration (D-BIL) but decreased albumin concentration (ALB) compared to control and others. TAZT treatment caused a significant (p<0.05) decrease in these effects unlike MSG and OATZ treatments while TAZT + MSG co-treatment significantly (p<0.05) reversed these effects compared to MSG-treated rats. Rats’ liver sections for rats in groups 2 and 3 showed severe hepatocellular degeneration and necrosis compared to others while those in group 4 (TAZT) showed the normal hepatic histo-architecture comparable to those in group 1 (control). Those in group 5 showed marked cellular swelling and leukocytic infiltration in only the centrilobular areas, suggesting active restorative responses. Conclusion: Thus, TAZT significantly mitigated the compromised histologic and biochemical integrities of liver function due to MSG treatment in rats via probable normalization of their enzymatic and non-enzymatic indicators of liver function. This suggests that TAZT could be useful in managing histologic and biochemical malfunction of rats’ liver due to MSG assault. Peer Review History: Received: 12 October 2023; Revised: 9 November; Accepted: 13 December, Available online: 15 January 2024 Academic Editor: Dr. Marwa A. A. Fayed, University of Sadat City, Egypt, maafayed@gmail.com Received file: Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Idoko Alexander, Caritas University, Enugu, Nigeria, idokoalexander1@gmail.com Dr. Dennis Amaechi, MrsFoluBabade Mini Estate, Flat 5 by Old Soldiers Quarter, Sabongari/Bwari, Abuja- Federal Capital Territory, Nigeria. amaechitoexcel@yahoo.com

Concordance between transbronchial lung cryobiopsy and surgical lung biopsy in patients with idiopathic multicentric Castleman disease: A report of four cases

BackgroundIdiopathic multicentric Castleman disease (iMCD) is a rare polyclonal lymphoproliferative disease often associated with pulmonary involvement. Recently, transbronchial lung cryobiopsy (TBLC) has been reported to be useful for the diagnosis of diffuse interstitial lung disease. However, there have been no reports of pathological assessment of TBLC for iMCD. MethodTo clarify the efficacy of TBLC in the diagnosis of iMCD, we retrospectively reviewed four iMCD patients who had undergone both TBLC and surgical lung biopsy (SLB). ResultsThe median age was 44 years; 2 males and 2 females. Two or three TBLC specimens were taken from each patient. All patients had no complications other than minimal bleeding. The size of the TBLC specimens was approximately 5–6 × 3–4 mm, and the alveolar region, and centrilobular and perilobular areas were adequately sampled. As with SLB, the extent of lung lesions and inflammatory cell infiltration could be sufficiently evaluated by TBLC. The presence of lymphoid follicles could also be assessed by TBLC; however, the germinal centers with lymphoid follicles were difficult to evaluate. The TBLC specimens could also be evaluated for immunostaining, especially IgG4 immunostaining, to rule out IgG4-related lung disease. Pulmonary pathological grading showed a high concordance rate between major pathological findings of TBLC and SLB. The pathologist's confidence level of TBLC for the diagnosis of iMCD was high in all cases. ConclusionsTBLC exhibits a high concordance rate with SLB in the pathological evaluation of iMCD, which may be useful for the diagnosis of iMCD.

Histopathological Study to Evaluate the Effect of Aqueous Extract of Portunuspelagicus and Mebendazole on Hydatid Cysts in Mice.

Hydatid disease is a parasitic infestation by a tapeworm of the genus Echinococcus sp., which has a global distribution. The current study was conducted to evaluate the effectiveness of the crustacean aqueous extract of Portunuspelagicus for 2 weeks of treatment compared to mebendazole on hydatid cyst in laboratory mice male Balb / C strain. Mice were infected intraperitoneally with 2000 protoscolices. After 12 weeks of infection, each mouse was treated with mebendazole (50mg/kg) and the hot aqueous extract of p. pelagicus (8, 16 g/kg). Samples of infected organs (liver, spleen, and lungs) were examined under a microscope to evaluate the morphological and histopathological changes of hydatid cysts and tissues. The study confirmed macroscopically that there were a number of hydatid cysts of different sizes in the liver, spleen, and lungs, splenomegaly, and congestion of the lungs of the positive control group. The histological changes in the organs of the group treated with the crustacean extract were represented by the vacuolation of hepatocytes in the centrilobular area of the liver. At the same time, the lungs show intensive peri-bronchiolar inflammation, pulmonary vascular congestion, and in the spleen, the deposition of amyloid-like material in the white pulp, extramedullary hematopoiesis, While the histopathological changes in the organs of mice treated with mebendazole, were represented by the presence in the mild liver vacuolation of the centrilobular area. In contrast, the lungs show mild pulmonary vascular congestion and emphysema, and the spleen shows normal white pulp, the normal red pulp of mice. The aqueous extract Portunuspelagicus and mebendazole are effective in controlling the contamination in the intermediate hosts.

Pathological lesions associated with Vibrio infection in Atlantic horse mackerel (Trachurus trachurus L., 1758) from the western coast of Tripoli, Libya.

Vibrios are aquatic bacteria causing Vibriosis in humans and aquatic animals. Vibriosis is a significant disease of cultured and wild fish. The present study aimed to address the impact of Vibrios on the health status of Trachurus trachurus inhabiting the coastal area of Tripoli. A total of 100 samples of (T. trachurus) were collected randomly from the Western Coast of Tripoli and Bab Al-Baher market, throughout the period from spring 2019 to summer 2019. All the sampled fish were examined externally and internally and lesions were recorded. Bacterial isolation from the liver and kidney was carried out using the appropriate culture media. Tissue samples were taken from the liver, kidney, and spleen in 10% neutral buffered formalin for a histopathology examination. The tissue sections were stained with hematoxylin and eosin to assess morphologically and Perl's Prussian blue for the demonstration of ferric iron. On average 69% of the infected fish exhibited at least one pathological lesion. Vibrios were recovered from 90% of the examined fish. The histopathological changes of the liver showed severe congestion of blood vessels (BVs), mononuclear cell infiltration surrounding a bile duct, granular degeneration and coagulative necrosis of hepatocytes in the centrilobular area, marked vacuolar degeneration of hepatocytes, activation of melano-macrophage centers (MMCs), multiple cysts of nematode in hepatic tissue (incidental finding). The histopathological alterations of the kidney showed severe congestion of BVs, vacuolar degeneration of the renal tubular epithelium, severe interstitial mononuclear cell infiltration, and marked activation of MMCs in the kidney. Moreover, congestion of BVs and marked activation of melano-macrophages (MMCs) were found in the spleen. The MMCs of most of the sampled tissues showed a strong positive reaction for ferric iron. The polluted aquatic environment by sewage at Tripoli Coast is an essential factor for triggering the pathogenicity and invasion of Vibrios to vulnerable Atlantic horse mackerel. Also, this study is a preliminary step to give a baseline for further future studies on epidemiology and control of Vibrio infection in Libyan fish.

A prospective study evaluating patterns of liver siderosis in beta-thalassemia major patients undergoing splenectomy

Background: Hepatic iron overload resulting from multiple red cell transfusions over a long period of time is a complication of thalassemia major. Hepatocellular iron deposits with a decreasing gradient from periportal to centrilobular areas in the liver have been referred to as the HH pattern and those deposits primarily in reticuloendothelial cells and macrophages with occasional heterogeneous deposits in periportal hepatocytes are referred to as the non-HH pattern. Aims and Objectives: The purpose of this study was to evaluate patterns of liver siderosis in these patients and correlate with number of units of blood transfused. Materials and Methods: Thirty beta-thalassemia patients were selected, having splenomegaly and during splenectomy, liver biopsy was taken and sent for histopathology examination and pattern of siderosis was noted as HH (Hepatocytes), non-HH (Reticuloendothelial cells/Kupffer cells/macrophages) or HH; non-HH (Mixed). Results: Mean number of units transfused was 48.429±9.53 (SD) for patients having HH pattern of liver siderosis whereas it was 58.667±13.27 (SD) for patients having HH; non-HH pattern of liver siderosis. Independent-samples non-parametric Mann–Whitney U test was performed and P-value was found to be 0.028 which emphasized that total number of units of blood transfused vary significantly with two groups showing different patterns of siderosis. Conclusion: Hence, pattern of liver siderosis can be a good indicator for transfusional iron overload in beta-thalassemia major patients.

Porto-sinusoidal vascular disorder.

It is well established that portal hypertension can occur in the absence of cirrhosis, as reported in patients with immune disorders, infections and thrombophilia. However, similar histological abnormalities primarily affecting the hepatic sinusoidal and (peri)portal vasculature have also been observed in patients without portal hypertension. Thus, the term porto-sinusoidal vascular disorder (PSVD) has recently been introduced to describe a group of vascular diseases of the liver featuring lesions encompassing the portal venules and sinusoids, irrespective of the presence/absence of portal hypertension. Liver biopsy is fundamental for PSVD diagnosis. Specific histology findings include nodular regenerative hyperplasia, obliterative portal venopathy/portal vein stenosis and incomplete septal fibrosis/cirrhosis. Since other conditions including alcohol-related and non-alcoholic fatty liver disease, or viral hepatitis, or the presence of portal vein thrombosis may occur in patients with PSVD, their relative contribution to liver damage should be carefully assessed. In addition to histology and clinical diagnostic criteria, imaging and non-invasive tests such as liver and spleen stiffness measurements could aid in the diagnostic workup. The introduction of PSVD as a novel clinical entity will facilitate collaborative studies and investigations into the underlying molecular pathomechanisms encompassed by this term.

Determination of the effect of Quercetinon oxidant- antioxidant parameters in the blood and liver tissues of rats given sodium fluoride experimentally

AimThe purpose of the study is to research the effect of quercetin, which has a good antioxidant characteristic in rats exposed to sodium fluoride (NaF) toxication, on oxidant and antioxidant activity in liver tissue and erythrocyte. Material and method40 Swiss albino male rats with a weight of approximately 20–25 gr were used in the study. The rats were separated into 4 equal groups (n = 10). The first group, the control group, was given normal drinking water; the second group was given 12 mg/kg/day NaF; the third group was given 40 mg/kg/day quercetin; the fourth group was given 12 mg/kg/day NaF+40 mg/kg/day quercetin orally for 30 days. As a result of the experiment, plasma AST and ALT activities were found. Total oxidant capacity (TOC) and total antioxidant capacity (TAC) analyses were made in liver tissue and erythrocyte hemogenisate. Histopathological analyses of the liver tissue were conducted. ResultsNo changes were found in plasma ALT activities between groups. Increases were found in AST activity of all groups. While erythrocyte TAC level was found to increase in fluorine and fluorine + quercetin group when compared with the control group, erythrocyte TOC level was found to increase in all groups when compared with the control group. No significant change was found in TOC and TAC levels in the liver tissue. In liver tissue histopathology, while hydropic degeneration and cellular necrosis were found in vena centralis area in fluorine group, hydropic degeneration was found in heptocytes in centrilobular area in the quercetin group. In the fourth group, hydropic degeneration and centrilobular necrosis were more severe. It was found that in rats which are given NaF experimentally, fluorine and quercetin caused histopathological degenerations in the liver tissue during this time. ConclusionWhile no changes were found in TOC and TAC levels of liver tissue, antioxidant capacity was found to be stimulated in fluorine groups in erythrocyte.

Liver protection from acetaminophen hepatotoxicity using copper(I)-nicotinic acid complex

The present study was performed to investigate the hepatotoxicity of acetaminophen and the possible hepatoprotective effect of copper(I)-nicotinate in rats through biochemical light and electron microscopy studies. Two groups of rats (39 in total) were used: group I (15 rats) received acetaminophen by intraperitoneal injection in a dose of 1000 mg/kg. While group II (15 rats) received an oral dose of 800 μg/kg copper(I)-nicotinate dissolved in 0.5 mL of saline three times through 24 h and 1 h after the last dose, and 9 rats were kept as control. Blood and tissue samples for biochemical, light, and electron microscopy were collected after 4, 12, and 24 h. Biochemical results showed a significant elevation in ALT, AST, and nitric oxide levels in rats who received acetaminophen only. In contrast, the corresponding levels of treated rats with the copper complex showed a less significant elevation in ALT, AST, and nitric oxide. Light microscopic examination of liver tissue taken from intoxicated animals showed congestion of the vasculature with hydropic and fatty degeneration. Centrilobular necrosis of the hepatocytes with glycogen depletion was observed in the centrilobular areas. Ultrastructural examination showed fatty degeneration, mitochondrial swelling, severe irregular dilatation of RER and SER, loss of glycogen granules, and pyknosis of the nuclei. Examination of livers of animals that received copper complex before intoxication revealed only cup-shaped mitochondria, a mild degree of fatty degeneration, and glycogen depletion with no evidence of necrosis. This work provides evidence for the antioxidant properties of the copper(I)-nicotinate complex and illustrates the pathological changes induced by acetaminophen in liver tissue.

Decreased Portal Circulation Augments Fibrosis and Ductular Reaction in Nonalcoholic Fatty Liver Disease in Mice

Nonalcoholic fatty liver disease often progresses to cirrhosis and causes liver cancer, but mechanisms of its progression are yet to be elucidated. Although nonalcoholic fatty liver disease is often associated with abnormal portal circulation, there have not been any experimental studies to test its pathogenic role. Here, whether decreased portal circulation affected the pathology of nonalcoholic steatohepatitis (NASH) was examined using congenital portosystemic shunt (PSS) in C57BL/6J mice. Whereas PSS significantly attenuated free radical-mediated carbon tetrachloride injury, it augmented pericellular fibrosis in the centrilobular area induced by a 0.1% methionine choline-deficient l-amino acid-defined high-fat diet (CDAHFD). PSS aggravated ductular reaction and increased the expression of connective tissue growth factor. Pimonidazole immunohistochemistry of the liver revealed that the centrilobular area of PSS-harboring mice was more hypoxic than that of control mice. Although tissue hypoxia was observed in the fibrotic area in CDAHFD-induced NASH in both control and PSS-harboring mice, it was more profound in the latter, which was associated with higher carbonic anhydrase 9 and vascular endothelial growth factor expression and neovascularization in the fibrotic area. Furthermore, partial ligation of the portal vein also augmented pericellular fibrosis and ductular reaction induced by a CDAHFD. These results demonstrate that decreased portal circulation, which induces hypoxia due to disrupted intralobular perfusion, is an important aggravating factor of liver fibrosis in NASH.

Acute necrotic hepatotoxicity caused by Lantana camara L. ingestion in dairy cattle

ABSTRACT: This study describes an outbreak of acute necrotic hepatopathy associated with spontaneous poisoning by Lantana camara L. in dairy cattle. A herd of 15 cows and heifers was introduced into a native pasture with limited food supply, and, sixteen days later, eight animals had spontaneous nasal hemorrhage, fever, lethargy, jaundice, and dry, dark stools with mucus and blood. The clinical course varied from two to five days. In the pasture where the cattle were kept, abundant adult specimens of L. camara L. with evident signs of consumption were observed. In total, seven cattle died and necropsy was performed in three of them. All animals had moderate jaundice, hemorrhage in the subcutaneous tissue and on the surface of different organs. The liver was slightly enlarged, with orange discoloration and enhanced lobular pattern. Histologically, multifocal areas of coagulative necrosis of hepatocytes in the centrilobular area, occasionally extending to the midzonal area, were observed, as well as marked hepatocellular degeneration and prominent cholestasis. The current study suggests that L. camara L. poisoning should be considered a differential diagnosis of acute and necrotic hepatotoxicity in cattle, despite the absence of photosensitization.

Spontaneous poisoning by Ateleia glazioviana (leg. Papilionoideae) in sheep and goats in the West region of Santa Catarina

ABSTRACT: This study reported the epidemiological data and the clinical and pathological conditions of spontaneous poisoning by Ateleia glazioviana in sheep and goats in the West region of Santa Catarina. The small ruminants were located in a place where there was a large amount of young plants of A. glazioviana and showing signs of consumption. The stock of sheep was composed of 250 animals, of which 45 died. In the goat herd, there were 28 animals, and of these, 27 died, and one was sacrificed. The main clinical signs were weight loss, fatigue, slow-walk, and eventually submandibular and facial edema. Some animals were found dead, and others died suddenly after being moved. Abortions and the birth of weak lambs were also observed. In total, five sheep and one goat were necropsied. The main macroscopic lesions were associated to eccentric cardiac hypertrophy and moderate, multifocal white areas in the epicardium and myocardium. Two sheep showed marked edema in the subcutaneous tissue of the head and neck and it could be noted hydrothorax and hydroperitoneum and liver with a nutmeg-like appearance. Histological changes were relevant in the myocardium. They consisted of fibrosis and myofiber necrosis associated with macrophage infiltrate, multifocal, low and marked swelling of cardiomyocytes with loss of fibrillarystriae, and increased nuclear volume. In two sheep, there was still congenital hepatic, as well as marked centrilobular and diffuse areas.

Involvement of neutrophils in rat livers by low-dose thioacetamide administration.

The administration with high dose (close to LD50) of thioacetamide (TAA), a hepatotoxicant used widely to induce experimental liver lesions, develops hepatocellular necrosis and subsequent inflammation (mainly M1-/M2-macrophages without neutrophil infiltration) in rats. We analyzed rat livers treated with a low dose TAA (50 mg/kg/body weight) at 6, 12, 18, 24 and 48 hr. The lesions in the affected centrilobular areas consisted of slight hepatocyte degeneration at 12 hr, and inflammatory cell infiltration at 18 and 24 hr; the lesions recovered until 48 hr. Translocation of intranuclei to cytoplasm of HMGB1, a representative molecule of damage-associated molecular patterns, was seen in some hepatocytes mainly at 6, 12, and 18 hr. As an interesting finding, at 12 hr, myeloperoxidase-positive neutrophil infiltration was observed in the affected centrilobular area. Additionally, CD68 M1-/CD163 M2-macrophages increased consistently at 12 to 48 hr. CXCL1, a chemokine for induction of neutrophils, began to increase at 6 hr and gradually increased at 12, 18 and 24 hr, apparently corresponding to the appearance of neutrophils. Collectively, the present findings at the low dose TAA indicated that along with M1-/M2-macrophages, neutrophils were characteristically seen, which might be elicited by cytoplasmic translocation of HMGB1 from nuclei. These finding would be useful for evaluation of hepatotoxicity at the early stages.

Diabetogenic potential of dexamethasone and effect Annona muricata methanolic bark extract as post-exposure therapy in albino rats

Diabetes mellitus (DM) is a metabolic disorder leading to high level of morbidity and mortality in human population and it has been identified as the leading cause of death from non-infectious diseases. The use of dexamethasone has been on the increase due to wide array of therapeutic effects it has and the use has mostly been without prescription, since it is a non- prescription drug. Therefore, the potential of dexamethasone to induce DM was studied. Some of the drugs currently used in the treatment of diabetes have their own problematic effects and also expensive, Annona muricata methanolic bark extract(AMMBE) was used in the treatment of dexamethasone-induced diabetes in rats. The research was carried out on albino rats in Federal College of Animal Health and Production Technology, Ibadan and lasted for twenty-eight (28) days. The rats were allotted into four groups (A, B, C and D). Group B, C and D were induced with glucocorticoid (Dexamethasone) (2mgkg-1) daily for seven (7) days intraperitoneally, while group A which was the positive control were given distilled water throughout without induction with glucocorticoid. Group B (the negative control) was induced with glucocorticoid with noAMMBE administration. Group C, was induced and treated with AMMBE at 400 mgkg-1for 14 days. While Group D, was induced with glucocorticoid and were treated with the standard drug (glibenclamide) at 2.5mgkg-1body weight of the rats daily for 14 days. Organ samples of liver, kidney and pancreas were collected for histopathological lesions evaluation. The result showed that dexamethasone induced diabetes after seven (7) days of intraperitoneal administration of 2 mgkg-1 body weights with the glucometer readings in most of the albino rats up to and above 129 mgdL-1. The average blood sugar levels in induced groups (B, C and D) were 132.0±4.05, 129.0±1.41 and130.0±2.93, respectively which were not statistically significant (P>0.05). After administration of AMMBE, the average blood sugar level for group B (126.0±1.41) was significantly different (P<0.05) from C (91.0±1.72) and D (87.0±2.97). Clinical signs of alopecia, dehydration, writhing, paw-licking were observed. There were massive losses of pancreatic cell mass grossly afterinduction with dexamethasone. Histopathological lesions observed ranges from no visible lesion in the control and glibenclamide treated groups to accentuation of hepatocytes in the AMMBE treated rats, and marked vacuolar degeneration of hepatocytes in periportal areas to centrilobular area with Kidney degeneration and multifocal coagulation necrosis of tubular epithelium in group induced with dexamethasone but untreated (group B)Diabetogenic potential of dexamethasone and effect Annona muricata methanolic bark extract degeneration, multifoci coagulation and necrosis. The blood sugar levels post exposure to AMMBE and Glibenclamide showed reduction in the sugar levels. It could be concluded that dexamethasone has the potential of inducing diabetes when its use is prolonged and AMMBE has antidiabetic effect which could be fully explored.

Acetaminophen-Induced Rat Hepatotoxicity Based on M1/M2-Macrophage Polarization, in Possible Relation to Damage-Associated Molecular Patterns and Autophagy.

Overdose of acetaminophen (APAP), an antipyretic drug, is an important cause of liver injury. However, the mechanism in the rat model remains undetermined. We analyzed APAP-induced hepatotoxicity using rats based on M1/M2-macrophage functions in relation to damage-associated molecular patterns (DAMPs) and autophagy. Liver samples from six-week-old rats injected with APAP (1000 mg/kg BW, ip, once) after 15 h fasting were collected at hour 10, and on days 1, 2, 3, and 5. Liver lesions consisting of coagulation necrosis and inflammation were seen in the affected centrilobular area on days 1 and 2, and then, recovered with reparative fibrosis by day 5. Liver exudative enzymes increased transiently on day 1. CD68+ M1-macrophages increased significantly on days 1 and 2 with increased mRNAs of M1-related cytokines such as IFN-γ and TNF-α, whereas CD163+ M2-macrophages appeared later on days 2 and 3. Macrophages reacting to MHC class II and Iba1 showed M1-type polarization, and CD204+ macrophages tended to be polarized toward M2-type. At hour 10, interestingly, HMGB1 (representative DAMPs) and its related signals, TLR-9 and MyD88, as well as LC3B+ autophagosomes began to increase. Collectively, the pathogenesis of rat APAP hepatotoxicity, which is the first, detailed report for a rat model, might be influenced by macrophage functions of M1 type for tissue injury/inflammation and M2-type for anti-inflammatory/fibrosis; particularly, M1-type may function in relation to DAMPs and autophagy. Understanding the interplayed mechanisms would provide new insight into hepato-pathogenesis and contribute to the possible development of therapeutic strategies.

Visualization and isolation of zone-specific murine hepatocytes that maintain distinct cytochrome P450 oxidase expression in primary culture

Parenchymal hepatocytes are responsible for most of the metabolic functions of the liver, but exhibit distinct functional properties depending on their localization within the hepatic lobule. Cytochrome P450 oxidases represent a family of drug-metabolizing enzymes, which are expressed predominantly in hepatocytes localized in the centrilobular area (zone 3). The present study describes a unique transgenic mouse strain that distinguishes zone 3 hepatocytes from periportal zone 1 hepatocytes by the intensity of EGFP fluorescence. Both zone 1 and zone 3 hepatocytes isolated from these mice showed the same zone-specific gene expression patterns as in liver tissue in vivo. Experiments using primary cultures of hepatocytes indicated that a combination of low oxygen concentration and activation of Wnt/β-catenin signaling maintained the expression of zone 3-specific P450 drug-metabolizing enzymes, which was characterized by their susceptibility to acetaminophen-induced mitochondrial dysfunction. These zone-specific hepatocytes provide a useful system in the research area of liver pathophysiology and drug development.

Cylindrospermopsin-Microcystin-LR Combinations May Induce Genotoxic and Histopathological Damage in Rats.

Cylindrospermopsin (CYN) and microcystins (MC) are cyanotoxins that can occur simultaneously in contaminated water and food. CYN/MC-LR mixtures previously investigated in vitro showed an induction of micronucleus (MN) formation only in the presence of the metabolic fraction S9. When this is the case, the European Food Safety Authority recommends a follow up to in vivo testing. Thus, rats were orally exposed to 7.5 + 75, 23.7 + 237, and 75 + 750 μg CYN/MC-LR/kg body weight (b.w.). The MN test in bone marrow was performed, and the standard and modified comet assays were carried out to measure DNA strand breaks or oxidative DNA damage in stomach, liver, and blood cells. The results revealed an increase in MN formation in bone marrow, at all the assayed doses. However, no DNA strand breaks nor oxidative DNA damage were induced, as shown in the comet assays. The histopathological study indicated alterations only in the highest dose group. Liver was the target organ showing fatty degeneration and necrotic hepatocytes in centrilobular areas, as well as a light mononuclear inflammatory periportal infiltrate. Additionally, the stomach had flaking epithelium and mild necrosis of epithelial cells. Therefore, the combined exposure to cyanotoxins may induce genotoxic and histopathological damage in vivo.

Glutamine Synthetase and Cytochrome P‐4502E1 Characterize Metabolic Zonation in Human Liver: Immunohistochemical Study

Hepatic metabolic zonation endows metabolic homeostasis and proper functioning of the liver under various physiological conditions. The zonation reflects the heterogeneity of gene expression and functions of hepatocytes along the centro‐portal axis of the liver lobule. The Wnt/ß‐catenin signaling pathway is the master regulator of hepatic zonation. The pathway maintains the metabolic zonation of glutamine synthetase (GS) and cytochrome P‐4502E1 (2E1) —among others—in the centrilobular parenchyma. GS detoxifies ammonia entering the liver as well as serves as an immunohistological marker of perivenous hepatocytes that make up the first three cell layers around the central vein. 2E1 mediates metabolism of xenobiotics and has a broader centrilobular expression than that of GS. While the zonation of GS and 2E1 has been documented in animal models, the phenomenon remains to be evaluated in human liver. This study assessed expression of GS and 2E1 in human cadaveric livers by immunohistochemistry. Ten livers of cadavers (mean age, 79.9 years) with minimal fibrotic changes were studied. Consecutive paraffin liver sections were stained with a polyclonal GS antibody or 2E1 antibody using an immunoperoxidase method. The central vein was defined as a hepatic vein located at the center of the classic liver lobule and showed a cross‐sectional diameter not exceeding 150 μm. In each liver, five to six veins were examined for the distribution of GS+ hepatocytes in the centrilobular area. In most cases, GS+ hepatocytes were arranged in a band of 1 to 3 cells wide in the perivenous area around the central veins (perivenous cells). In some instances, GS staining was observed in hepatocytes beyond the perivenous area (recorded as non‐perivenous cells). Midlobular and periportal hepatocytes lacked GS staining. Expressed as per central vein, counts of perivenous GS+ cells were 14.9 ± 2.2 and non‐perivenous cells were 5.6 ± 1.8. The mean 2E1 zonal score was 1.35 ± 0.35. Total GS+ cell numbers (perivenous plus non‐perivenous) were found to correlate with 2E1 zonal scores (P > 0.05, N = 10).ConclusionsExpression of GS and 2E1 characterizes the metabolic zonation in the liver of aged cadavers, in accordance with the findings of animal studies. The correlation of GS with 2E1 expression suggests a link between the hepatic zonation of GS and 2E1, which is consistent with the notion that the zonation is mediated by the Wnt/ß‐catenin signaling pathway.