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Introduction: the disease by non-alcoholic fatty liver is considered the hepatic expression of the metabolic syndrome and is accompanied by histological and functional alterations of the liver. The Morphometry is a valuable tool in the assessment of liver morphology. Objective: to describe the histomorphometric differences in the liver of a group of healthy rats and one of them subjected to a state of metabolic syndrome. Methods: a developmental, correlational, cross-sectional, experimental research study with quantitative approach was conducted in the period from October 2015 to September 2019, using a system of morphometric methods. Histological liver slices were analyzed to 16 male Sprague-Dawley rats randomly distributed in two experimental groups of eight animals for each group. Parametric test (one-factor ANOVA) was applied for group comparisons. The existing relationships between the variables were determined. Results: the area of the nucleus was greater in the hepatocytes of the perivenous zone in the induced group. The area of the cytoplasm was greater in the hepatocytes of the perivenous zone, but its behavior was homogeneous in the two study groups. Conclusions: the differences found between the control and induced groups with respect to nuclear and cytoplasmic area could constitute the morphological expression of the biochemical alterations caused by the metabolic syndrome. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the possible toxic effects associated with prolonged use of Pterocarpus santalinoides leaf extract. Methods: Methanol leaf extract of Pterocarpus santalinoides (MEPS) was incorporated in rat feed at different doses (2.5, 5.0 and 10.0 mg/kg) for 90 days. On days 30, 60 and 90, blood was collected from the retro-orbital plexus of four rats that were randomly selected from each group (n = 14). Full blood count was done using an auto hematological analyzer, liver marker enzymes (AST, ALT and ALP) and kidney function parameters (serum urea and creatinine) were determined following standard methods as contained in Randox® test kits. The histopathological examination of the liver, kidney, lung and heart was also carried out. Results: MEPS did not cause significant (p > 0.05) changes in the body weight, relative organ weights and hematological indices of treated rats when compared with control. The extract (5.0 and 10.0 mg/kg) significantly (p < 0.05) increased the AST activity of the rats on day 90. Total bilirubin concentration was significantly (p < 0.05) reduced by all doses of MEPS, while serum urea and creatinine were significantly (p < 0.05) increased. Degeneration of hepatocytes and tubular epithelial cells of the kidney were observed in rats treated with MEPS at a dose of 10.0 mg/kg on days 60 and 90 of the study. Conclusion: MEPS does not cause significant toxicity in albino rats, when administered for a short duration. However, long term therapy with the extract precipitates liver and kidney damage. [ABSTRACT FROM AUTHOR]

Purpose: To study the influence of microRNA-33b (miR-33b) on liver cancer cell proliferation, migration and invasiveness, and the mechanism involved. Methods: MicroRNA-33b or Fli-1 overexpression plasmid was transfected into liver cancer (SMMC7721) cells. Cell proliferation, migration, and invasiveness were determined using cell counting kit 8 (CCK-8), scratch test, and Transwell invasion assay, respectively. The amounts of miR-33b and Fli-1 in liver cancer tissues, paracancerous normal tissues, and miR-33b overexpression and control groups were measured using qRT-PCR, while protein concentration of matrix metalloproteinase 2 (MMP-2) was assayed using Western blotting. Results: Fli-1 protein was markedly upregulated in liver cancerous cells, relative to paracancerous normal tissues (p < 0.05). MicroRNA-33b protein expression was also significantly upregulated in miR- 33b overexpression group, but the corresponding Fli-1 expression was downregulated in miR-33b overexpression group, relative to control (p < 0.05). MicroRNA-33b overexpression significantly and time-dependently inhibited SMMC7721 cell proliferation and migration, but it reduced the degree of apoptosis (p < 0.05). Liver cancer (SMMC7721) cells in miR-33b overexpression group were less invasive than the control group (p < 0.05). Similarly, miR-33b overexpression significantly downregulated MMP-2 protein expression in SMMC7721cells (p < 0.05). Conclusion: Overexpression of miR-33b suppresses the proliferation, migratory and invasive potential of hepatic cancer cells via down-regulation of Fli-1 and MMP-2 protein expression. This finding may be useful in the identification of new liver cancer drugs. [ABSTRACT FROM AUTHOR]

In chronic liver disease, orthotopic transplantation is the only current therapeutic alternative but it is limited due to lack of donors. Trials with adult stem cells in acute liver damage show promising results. The aim of this work was to evaluate the effectiveness of human adipose stem cell (h-ASC)infusion in rats with chronic liver damage. Rats with thioacetamide-induced liver fibrosis were grouped into: group I control that did not receive thioacetamide and h-ASC, group II received thioacetamide and saline i.v., group III received thioacetamide and h-ASC 1 x 106/kg i.v. via tail vein. Histological liver regeneration was evaluated by METAVIR index, while Macrophagocytus stellatus (Kupffer cells), stellate cells a-SMA+ and collagen I+ cells by immunohistochemistry; functional damage was evaluated by blood levels of the analytes Aspartate Aminotransferase (AST), Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), Urea and Blood Urea Nitrogen (BUN) and hemogram. The results show attenuation of structural liver damage evidenced by decreased nodules, degree of histologic injury on Metavir score, and decreased Macrophagocytus stellatus, a-SMA+ cells and type I+ collagen cells;functionally there is moderate reduction of AST, ALT, urea, BUN and moderate decrease of white cells but favorable effect on mean corpuscular volume and mean corpuscular hemoglobin. Eight weeks after infusion there is a small population of h-ASC in the liver. Inconclusion, intravenous infusion of h-ASC in rats reduces functional and structural damage of hepatic fibrosis with low persistence of h-ASC in the liver parenchyma. To our knowledge this is the first work that evaluates the effect of h-SC in the model of chronic murineliver damage and the persistence of transplanted cells. [ABSTRACT FROM AUTHOR]

The liver is one of the most important organs that contribute to maintain metabolic homeostasis in vertebrates, with a high regenerative capacity. Liver is constituted by diverse cellular types, which work together to accomplish the organ function. Hepatocytes are the main cellular type responsible for most of hepatic functions; they are a heterogeneous population with specialized metabolic functions. Several signaling pathways such as TGF-β/Smads, Hippo/YAP-TAZ and Wnt/β-catenin, among others, regulate hepatocytes phenotype. These cells are normally in a quiescent state but they exhibit plasticity in response to liver damage; thus, they can proliferate or change their phenotype through process such as transdifferentiation or transformation in order to contribute to the maintenance of liver homeostasis or during the development of diverse pathologies. [ABSTRACT FROM AUTHOR]

Hepatic stellate cells (HSCs) are a major source of collagen in the liver and play a crucial role in fibrogenesis induced by schistosomes. Resting HSCs function primarily storing vitamin A, but in response to injury of the liver tissue, are activated and undergo transdifferentiation to myofibroblasts, which are characterized by the production of extracellular matrix (ECM) components rich in fibrillar collagens. In schistosomiasis, a fibrogenic granulomatous inflammatory response develops, directed mainly against schistosome eggs, resulting in liver pathology associated with the disease. In the process, the role of HSCs has not been studied conclusively, not only in schistosomiasis but also in other parasitoses. In Schistosoma mansoni infection it is known that they are present in the activated state (myofibroblasts), in the fibrotic border of liver granuloma. In contrast to other diseases, it has been demonstrated that expression and activation of these cells leads to the progression of the fibrogenesis, which may lead to liver cancer. Likewise, the low expression and activation is associated with decreased fibrogenesis and the possible limitation of the pathology. Fibrogenesis and immunopathogenesis caused by S. mansoni, studied in murine models, may have broad implications for human health, and ultimately it translates into an effective intervention strategy for schistosomiasis, as well as for other liver granulofibrotic diseases which can induce cancer in this tissue. Therefore, the following review describes the role of hepatic stellate cells in the inflammatory-fibrotic response of murine schistosomiasis. [ABSTRACT FROM AUTHOR]

Livers of Sprague Dawley rats were irradiated with daily doses of 6 J/cm² emitted by a laser AsGa, equivalent to . 904 nm during 15 days. Experiment animals were anaesthetised and killed after 5, 10, 30, 45 and 60 days post irradiation, in order to obtain samples of liver by surgery. These were processed for transmission electron microscopy, and morphometric techniques were applied using 8,500 X magnification with special emphasis on measuring the volumetric fractions of cell components in order to determine the duration of infrared stimulation. Analysis of the results between control hepatocytes and those irradiated with doses of 6 J/cm2 and by period after infra-red stimulation revealed the existence of marked differences between the volumetric fractions of cell components which determine cell function or are involved in protein synthesis. The measurements show clearly that the effect of the infrared laser persists up to 30 days post stimulation, with evidence of modifications of organelles revealing high functioning, while after 30 days a notable inhibition of this functioning is observed. It is therefore concluded that the effects of infrared radiation persist for precise times, provoking a drastic transformation in hepatocyte components, and thus the functioning of these high-metabolism cells. [ABSTRACT FROM AUTHOR]

Mycoplasma pneumoniae has come to be recognized as a worldwide cause of primary atypical pneumonia. Apart from respiratory tract infections, this organism is also responsible for producing a wide spectrum of non-pulmonary manifestations including neurological, hepatic, cardiac diseases, hemolytic anemia, polyarthritis and erythema multiforme. This review includes some of the newer aspects of the knowledge on this pathogen, clinical characteristics of infections, how it causes disease, radiology and various laboratory tools in diagnosis, differential diagnosis and treatment. [ABSTRACT FROM AUTHOR]

During menopause, hormonal changes such as decreased estradiol and increased follicle stimulating and luteinizing hormones occur. In premenopausal women fibrosis and hepatic steatosis is less than in postmenopausal women and improves when hormone replacement therapy is administered. The aim of this study was to determine quantitative aspects of the liver of rats undergoing an experimental model of ovariectomy-induced menopause. We used 10 Sprague-Dawley (Rattus norvergicus) healthy adults. The rats were weighed and divided into two groups (bilateral oophorectomy = Group Ovx and control = Group Sham The animals were sacrificed at 60 days and the liver removed obtaining a piece of each liver. Five cuts were made of 4 micron and stained with HE. We analyzed five fields per slide. M42 test was used. Stereological parameters considered were as follows: Nv, Vv, Sv and total number (Tn) of hepatocytes and sinusoids. The average weight of Ovx and Sham group was 300.8 g and 285.8 g respectively. The Nv of hepatocytes of rats subjected to sham surgery (CS) and Ovx (CO) was 6.89 and 7.70 x105/mm³ x105/mm³, respectively. The Vv of CS and CO hepatocytes was 71.92% and 80.48%, respectively. SV and CO, CS hepatocytes was 260.61 mm²/ mm³ and 273.64 mm²/mm³, respectively. The average volume of CS livers was 8.40 mm³ and hepatocyte Tn averaged 5.79 x 106. The average volume was 9.28 mm³CO livers and Tn of 7.15 x 106 Regarding the sinusoids, the Nv in the liver CS and CO was 2.81 x 105/mm² and 2.64 x 105/mm³, respectively. The Vv of sinusoids in CS and CO was 16.74% and 16.46%, respectively. The sinusoids in rats Sv CS and CO was 49.40 mm²/mm³and 45.21 mm²/mm³, respectively. The sinusoids Tn CS and CO averaged 2.37 x 106 and 2.45 x 106, respectively. The lack of estrogen can cause fibrosis and hepatic steatosis as noted by other authors, but also changes in the organization and the proportion of the components of the liver, factors to consider during diagnosis and prognosis of liver disorders. [ABSTRACT FROM AUTHOR]

Sprague Dawley rat livers were irradiated with 8 and 16 J/cm² daily doses during 15 days from the AsGA laser. equivalent to 904 rim. Liver samples were surgically removed from rats previously anesthetized, then processed for electronic microscopic transmission and subsequently studied and subjected to morphometric techniques using 8.500 X enlargements with special emphasis on quantifying cellular component volumetric fractions. The result analysis of the hepatocytes irradiated with 8 and 16J/cm² doses revealed that there were marked differences between the volumetric fractions of cellular components that determine cellular functionality and protein synthesis, a quantification that clearly demonstrates that with a dose of 8 J/cm² the optimum stimuli is achieved in order to obtain high functionality, while with a dose of 16 J/cm² a notable reduction of that functionality is noted, concluding that the effects of specific infrared radiation doses provoke a drastic transformation of its components in hepatocytes, and therefore its functionality, activating or inhibiting it, and representing the effect of these stimulations over this elevated metabolism cellular type. [ABSTRACT FROM AUTHOR]

Liver samples were taken from previously anaesthetised Sprague Dawley rats, both normal and irradiated with daily doses of 1, 2, 4, 8, and 16 J/cm2 applied over 15 days by AsGa laser equivalent to 904 nm. These samples were then processed for optical microscopy. They were studied and subjected to morphometric techniques using 1000X magnification, placing special emphasis on the quantification of the areas of nuclei and nucleoli. An analytic comparison of the results between normal and irradiated hepatocytes reveals the existence of significant differences between both the nuclear and nucleolar areas studied, from which it is concluded that the effect of these doses of infrared radiation is to provoke a drastic transformation in the components of the hepatocytes, and therefore in their functioning, principally with respect to protein synthesis, and that this would be the effect of stimulation of this nature on this type of high-metabolism cell. [ABSTRACT FROM AUTHOR]

While studies have been conducted in the liver of different species, there is little research on the guinea pig, a rodent of easy handling and used as an experimentation animal. The aim was to describe in the guinea pig liver, some histological and histochemical aspects, which would allow experimental studies to be carried out. We used seven male guinea pigs (Cavia porcellus) obtained from the Bioterium of the Universidad de La Frontera, Temuco, Chile. Samples were fixed in buffered formalin and processed for inclusion in paraplast. Serial thick of 5 μm were stained for histological and histochemical studies. The liver presented a lobular architecture vague borders and portal tracts consisting of vascular structures and canalicular bile. Parenchymal cords were composed of hepatocytes with a cuboidal to polygonal appearence, and radially distributed from the central lobular vein. It showed the presence of glucogen liver cells, and hemosiderin neutral mucins. The average diameter of hepatocytes was 17.25 μm and the nucleous was of 7.31 μm. The guinea pig liver shows similarities with other species, however, to determine morphological parameters, age, environmental conditions of animals, feeding, etc. must be considered. [ABSTRACT FROM AUTHOR]

Therapeutic vaccination of chronic infectious diseases has been extensively explored because of its possible contribution to their eradication. In particular, therapeutic vaccination of hepatitis B virus chronic infections is especially interesting since this disease is characterized by a sustained necro-inflammatory process of the liver that may evolve into more severe conditions including cirrhosis and hepatocellular carcinoma. The basic role of the immune system in the healing process of this chronic infection suggests that it offers a favorable setting for immunotherapeutic treatments, either spontaneously or as a result of antiviral therapy. However, no vaccine has been able to cure this or any other chronic infection in spite of the large number of vaccine candidates tested. The knowledge of the liver as a lymphoid organ and the limited advances of therapeutic vaccination demand more thorough analyses within the rationale of current vaccine candidates. In the last ten years there has been an increased knowledge of innate immunity and intra- and extra-hepatic signaling mechanisms, to support a rational design of vaccine strategies. The high costs and low effectiveness of conventional treatments, and the large amount of chronic carrier patients for this virus, indicate a favorable setting for the development of immunotherapeutic products against chronic hepatitis B. It is possible to predict that adjuvant strategies that take into account the properties of the liver as a lymphoid organ would have an impact in the development of this new field of therapeutic vaccines. [ABSTRACT FROM AUTHOR]

The infrared lasser emitted by the Gallium Arsenide diode provides an adequate therapy for articular lessions due to their healing, analgesic, and anti-inflammatory powers. It also promotes at cellular level mitochondrial ATP synthesis, modulates Calcium channels and activate mitotic processes by increasing DNA and protein synthesis. To determine the effective doses which stimulates rat liver protein synthesis, several samples from normal and irradiated tissues to intensities of 1, 2, 4, 8, and 16 Joules/cm2 by 15 consecutive days were taken. These samples were later prepared and observed under transmission E.M. (10000X) and analyzed by morphometric studies, where volume and organelle distribution, such as nucleus, cytoplasm, endoplasmic reticulum, glycogen inclussions, nucleolus, eu and heterochromatin were accounted, together at nuclear-cytoplasmic relationships and the cellular and nuclear areas. Under comparison normal and irradiated hepatocytes presented a significative difference in all evaluated parameters. It can be concluded that at certain specific level of infrared irradiation, hepatocytes alter their morphology by modifyng those cellular components involved in protein sintesis. [ABSTRACT FROM AUTHOR]

Objective. To determine the 50% lethal concentration (CL50) and anatomopathological lesions associated with exposure to a mixture of Roundup® herbicide and Cosmoflux® 411 surfactant in juvenile silver Pacu (Piaractus brachypomus). Materials and methods. Fish of 44.5 ± 3.7 g body weight were exposed for 96 h to several concentrations of herbicide plus surfactant mixture. Mortality was recorded at 96 h and tissue samples were collected for histopathological evaluation. Results. The CL50 was 23.42 mgI-i for Roundup® (p

Trypanosoma evansi is a hemoparasite (Kinetoplastida: Trypanosomatidae) that causes a parasite infection known in south america as horse derrengadera. this trypanosomiasis is of great concern in venezuela because horse are used in farms of apure state for diverse activities, of importance for agriculture production in the region. the knowledge is very scarse in relation to ultrastructural alterations caused by Trypanosoma evansi in horses and natural and experimental hosts. the present investigation represents the continuation of a series of studies about histological, histochemical and ultrastructural alterations produced in mammals by venezuelan isolates of T. evansi. Ten mice were experimentally infected with T. evansi, liver samples prepared according to transmission electron microscopy and then thin sections of livers were observed in an electron microscope. During the course of the disease we found different degrees of changes in hepatocytes as follows: abundance of lipid droplet, irregular distribution of glycogen particles, changes in peroxisome nucleoid, presence of lipofuscine granules, swollen smooth endoplasmic reticulum, pleomorphic mitochondria and rough endoplasmic reticulum disappearance. Additionally, we describe endothelial alterations and the occurrence of parasite intracellular forms, confirming our findings of previous studies realized in adrenal glands in relation to the existence of an intracellular stage of T. evansi in experimentally infected mice. [ABSTRACT FROM AUTHOR]

Introduction. Hepatocarcinoma (HCC) is defined as a primary malignant neoplasm of the liver that is originated in hepatocytes. The HCC is the more frequent malignant neoplasm of the liver. The incidence of this neoplasm increased in developed countries and its relation with the infection by hepatitis C virus was identified. HCC represents the seventh more frequent cancer in men and the ninth more frequent cancer in women. Objective. To improve the survival of the patients with hepatocarcinoma dealth with chemoembolization. Material and methods. Between 2004 and 2006, eigth patients with hepatocellular carcinoma were included in the study; were treated with transcatheter arterial chemoembolization (TACE), alphaphetusprotein measurement studied, was used coefficient of correlation of Pearson and use Kaplan-Meier for the survival of this patients. Results. Were eigth studied patients, the average of age was of 68 years old, the average of alphaphetusprotein was of 423.2 ng/mL, the survival was 80% in the 13 month after the chemoembolization. No major complication occurred during procedure. Conclusion. The survival of the patients with hepatocarcinoma dealt with chemoembolization was greater in relation to the patient without chemoembolization, there was relation between the levels of AFP and no the size of the tumor. The improvement in the quality of life as well as the local air traffic control of hepatocarcinoma profit with the chemoembolization. [ABSTRACT FROM AUTHOR]

Introduction: Nuclear receptor LXRα (liver X receptor alpha) has a beneficial effect on the reverse pathway of cholesterol and reverts some defects in the lipid metabolism that are related with cardiovascular risk. LXRα activity is modulated by agonists of the nuclear receptor PPARγִ (Peroxisome Proliferator-Activated Receptor gamma), that are used for type 2 Diabetes treatment. Objective: To observe LXRα gene expression and some genes that it regulates, after the treatment with a PPARγ agonist in the absence of estrogens. Method: 18 New Zealand female rabbits were ophorectomized. Three groups selected themselves randomly. In two groups, were treated with hypercholesterolemic diet during 3 weeks alternating with normal diet for a total of 24 weeks, to one of these groups, administered placebo (group 1, n=6) and to another one rosiglitazone 3 mg/Kg/día (group 2, n=6). The third group took like group control with normal diet. The expression of the genes of lxrα, abca1 and il-1β? was determined by means of RT-PCR. Results: An increase in LXRά mRNA expression was observed in liver, without any variation in ABCA1 in artery. A reduction on IL-1β levels in artery after rosiglitazone therapy was observed. Conclusion: PPARγ activation increases LXRα function in the absence of estrogens. However PPARγ might execute some beneficial effect on reverse cholesterol pathway in a different route from LXRα/ABCA1 pathway. [ABSTRACT FROM AUTHOR]

The standard model of three populations (healthy and unhealthy hepatocytes, and viral load) for the study of the dynamics of hepatitis C virus (HCV), is compared with viral dynamic model with alanine aminotransferase (ALT). In terms of the threshold parameter that it's the same for both models, the existence and local asymptotic stability of the endemically infected equilibrium steady state, and the global stability of the healthy individual equilibrium steady state are established. Furthermore, an experimental study is presented showing that it's possible to carry out the monitoring of hepatic damage biopsies free by numerical parameter estimation, considering only viral load and ALT levels measurements and a reasonable assessment of pretreatment hepatic damage. [ABSTRACT FROM AUTHOR]

Se estudiaron por microscopía electrónica de transmisión y confocal, biopsias hepáticas y células mononucleares de sangre periférica (CMSP) en 150 pacientes cubanos con hepatitis C crónica. Se hallaron elementos novedosos acerca de la detección de la cápsida del VHC en células extraparenquimatosas del hígado. Se visualizó la presencia de apoptosis en las células hepáticas y en CMSP mediante la técnica TUNEL y la activación de efectores de la apoptosis. Se observó por primera vez, la presencia de ARN de cadena positiva y negativa en hepatocitos y en CMSP en más del 80% de las muestras analizadas de pacientes ARN negativo en suero, con mejoría histológica y bioquímica. Se mostró por primera vez, que las células extraparenquimatosas del hígado y las CMSP constituyen reservorios para la replicación del VHC. La presencia en las células estrelladas del AgcHC y de las partículas del núcleo del VHC, detectadas por primera vez, mostraron que el VHC puede infectar directamente a estas células y su transdiferenciación en células similares a miofibroblastos, lo que modula así el proceso de fibrogénesis hepática y demuestra que junto a los fibroblastos, las células estrelladas desempeñan una función relevante en la fibrosis hepática. La aplicación de estos conocimientos tiene implicaciones importantes para el diagnóstico, seguimiento y pronóstico de la enfermedad de referencia. [ABSTRACT FROM AUTHOR]

El láser infrarrojo genera emisiones las cuales inducen en las células tanto una activa síntesis proteica como modulando síntesis de DNA, de ATP mitocondrial y de fibras colágenas, de igual manera generando activación de la proliferación celular, las concentraciones de calcio citoplasmático y la actividad de un número creciente de enzimas. De hígados de rata irradiados con dosis diarias de 6 Joules/cm² durante 15 días consecutivos y sacrificadas a los 5,10, 30,45 y 60 días post irradiación fueron obtenidas muestras de hepatocitos para posteriormente ser tratados con técnica para microscopía electrónica de transmisión obteniéndose micrografías con aumentos finales de 8.500 X, realizándose en ellas estudios morfométricos con el propósito de cuantificar las fracciones volumétricas de componentes celulares pertenecientes a estas células con la dosis infrarroja descrita y visualizar la persistencia de los efectos de dicha estimulación. Se evaluaron fracciones volumétricas de: Citoplasma, núcleo, Retículo Endoplasmático Rugoso, mitocondrias, inclusiones de glicógeno, eu y heterocromatina. Los resultados derivados del estudio morfométrico comparativo entre hepatocitos irradiados con 6 J/cm² y sacrificados con diferentes días post irradiación indican que existen marcadas diferencias cuantitativas en todos los componentes celulares evaluados y se concluye entonces que los efectos de las estimulaciones infrarrojas persisten hasta 30 días post irradiación, estadio en el que se visualiza una marcada actividad celular básicamente de los componentes celulares involucrados en síntesis proteica. De igual manera, por sobre esta etapa se observa una constante disminución en el volumen de dichos componentes celulares, situación que indica una sostenida disminución en la actividad celular. Comprobándose, por ende, que los efectos de radiaciones infrarrojas producen drásticas transformaciones de sus constituyentes durante un cierto período de tiempo y modulando la funcionalidad en este tipo celular de elevado metabolismo [ABSTRACT FROM AUTHOR]