Numerical Density Of Hepatocytes Research Articles

Influence of nanostructured calcium aluminate and calcium silicate on the liver: histological and unbiased stereological analysis

To examine the potential systemic toxicity of nanostructured materials based on calcium silicate and calcium aluminate, for potential application in Dentistry. Twenty-four Albino Wistar rats aged 2months were used as an invivo animal model for subcutaneous implantation of the investigated materials, placed in polyethylene tubes. Thirty days after implantation, the livers of the rats were analysed and following histological and stereological parameters were evaluated for volume density of hepatocytes and blood sinusoids, number and numerical density of hepatocytes, surface of hepatocytes and their nucleuses, nucleocytoplasmic ratio and mitotic index of hepatocytes. Stereological measurements were achieved using Cavalieri's principle, with grid P2 and unbiased analysis. Additionally, immunohistochemistry studies were performed to further analyse changes in liver tissue. Several haematological and biochemical parameters of blood of experimental animals were also analysed, as well as local tissue reactions around the implants. Statistical analysis was performed using parametric (anova and t-test) and nonparametric tests (Kruskal-Wallis and Mann-Whitney U-test) depending on data distribution. Implanted dental cements led to an increase in stereological and histological parameters in liver tissue compared to control rats. Although the investigated parameters mostly showed significant differences between control and experimental animals, the liver tissue of the experimental animals did not have visible signs of pathological changes. This was supported by the analysis of blood parameters which were not significantly different between control and experimental animals. Also, the subcutaneous tissues had minimal inflammatory reactions. Immunohistochemistry studies revealed that nanostructured materials induced proliferation of hepatocytes, but that the immunological response to the materials was not strong enough to induce proliferation of immunoreactive cells in liver in the observed time period. This study was performed as a contribution to the attestation of the biocompatibility of dental cements based on calcium silicate and calcium aluminate. Although these materials induced several changes in the liver structure, they were not clinically relevant and represent a normal and reversible response of the liver to the presence of biocompatible materials in the body. Blood and immunohistochemistry analyses and local tissue reactions further confirmed that these materials possess good biocompatible potential.

Study of liver in HBV-related hepatocellular carcinoma: Stereology shows quantitative differences in liver structure.

Hepatocellular carcinoma (HCC) is one of the main consequences of liver chronic disease. Hepatocellular carcinoma-related changes may be seen in patients with chronic hepatitis B. The aim of the current study was to quantitate liver tissue elements by stereological technique in patients with hepatitis B-related cancer and compare the results with control and only hepatitis B group. Needle liver biopsies from 40 patients with only chronic hepatitis B infection, from 41 patients with only early hepatocellular carcinoma, from 40 patients with early hepatitis B-related cancer and 30 healthy subjects (control group) were analyzed by stereological method using systematic uniform random sampling method. Haematoxylin and eosin stained sections were used. The numerical density of hepatocytes, hepatocyte volume, numerical density of Kupffer cells, volume density of the connective tissue in the portal space, and volume density of the connective tissue were assessed. Quantitative analysis of liver samples indicated that there were statistically significant differences in the numerical density of hepatocytes, hepatocyte volume, numerical density of Kupffer cells, volume density of the connective tissue in the portal space, and volume density of the connective tissue between control and hepatitis B-related cancer and hepatitis B groups. Quantitative, stereological technique is simple and reliable for evaluating HCC in chronic hepatitis B. It is useful for assessing the liver tissue parameters. Stereology is recommended for the diagnosis of people prone to cancer in patients with chronic hepatitis B.

Stereological analysis of size and density of hepatocytes in the porcine liver.

The porcine liver is frequently used as a large animal model for verification of surgical techniques, as well as experimental therapies. Often, a histological evaluation is required that include measurements of the size, nuclearity or density of hepatocytes. Our aims were to assess the mean number-weighted volume of hepatocytes, the numerical density of hepatocytes, and the fraction of binuclear hepatocytes (BnHEP) in the porcine liver, and compare the distribution of these parameters among hepatic lobes and macroscopic regions of interest (ROIs) with different positions related to the liver vasculature. Using disector and nucleator as design-based stereological methods, the morphometry of hepatocytes was quantified in seven healthy piglets. The samples were obtained from all six hepatic lobes and three ROIs (peripheral, paracaval and paraportal) within each lobe. Histological sections (thickness 16μm) of formalin-fixed paraffin-embedded material were stained with the periodic acid-Schiff reaction to indicate the cell outlines and were assessed in a series of 3-μm-thick optical sections. The mean number-weighted volume of mononuclear hepatocytes (MnHEP) in all samples was 3670±805μm3 (mean±SD). The mean number-weighted volume of BnHEP was 7050±2550μm3 . The fraction of BnHEP was 4±2%. The numerical density of all hepatocytes was 146997±15738 cellsmm-3 of liver parenchyma. The porcine hepatic lobes contained hepatocytes of a comparable size, nuclearity and density. No significant differences were identified between the lobes. The peripheral ROIs of the hepatic lobes contained the largest MnHEP with the smallest numerical density. The distribution of a larger MnHEP was correlated with a larger volume of BnHEP and a smaller numerical density of all hepatocytes. Practical recommendations for designing studies that involve stereological evaluations of the size, nuclearity and density of hepatocytes in porcine liver are provided.

Macro- and microstructural descriptions of the zebrafish (Danio rerio) liver.

The liver is an essential metabolically active organ, responsible for many vital life functions such as metabolism, synthesis, and storage. This study describes the macroscopic and microscopic zebrafish liver and its temporal changes during a period of 13 weeks. Forty-six adult zebrafish were used (46), of which 27 were females and were 19 males. Seven fish were euthanized initially for macroscopic evaluation and 3 fish were euthanized weekly for 13 weeks for microscopic evaluation. Routine histological technique was performed; the slides were stained with haematoxylin/eosin and periodic acid-Schiff. The volumetric (Vv(h)) and numerical (Nv(h)) densities of hepatocytes and vacuolation intensity were determined weekly. The liver was located in the coelomic cavity ventrally to the swim bladder, slightly brownish and divided into 3 hepatic lobes. Microscopically, it consisted of hepatocytes forming a muralium duplex around the sinusoids. The staining of the cytoplasm of hepatocytes was more eosinophilic and more basophilic in males and females, respectively. There was no formation of portal triads and phagocytic cells. The gallbladder had transitional epithelium, and the bile ducts had simple cuboidal epithelium. The volume and numerical density of hepatocytes during the 13 weeks was not statistically different, but these parameters displayed a positive correlation. The vacuolation was due to the presence of glycogen. The zebrafish liver has macro and micro structural particular features while, quantitatively, the volume and number of hepatocytes showed great capacity to respond to the physiological needs of the animal at the time.

A study of regenerative ability of liver after repetitive heat stress induced liver injury

Background: It is well known that heat stress produces liver injury. It is also known that liver regenerate after injury. This way, there should be almost no or minimal alteration in the size of the liver after regeneration. Aims & Objective: In the present study, after heat induced liver injury, the ability of liver to regenerate itself was assessed. Liver injury was assessed by biochemical [Serum Glutamic Pyruvate Transaminase (SGPT); Serum Glutamic Oxaloacetic Transaminase (SGOT); and Alkaline Phosphatase (ALKP)], morphological, and morphometric changes. On the other hand, Liver regeneration was evaluated by morphological and morphometric observations of male adult albino rats (Wistar strain). Material and Methods: The experimental animals were subjected to repetitive heat stress for 4 hours daily, at 37 ± 0.5 ˚C in a Biological Oxygen Demand (BOD) incubator (relative humidity 65 - 82%) for 2 and 5 consecutive days. Biochemical assessment was done on blood collected from left ventricle of beating heart of rats. Morphometric and morphological studies were conducted under light microscope on paraffin sections (H&E) of liver from control and experimental animals. The morphometric analysis was done by intersection – point counting method, using simple square lattice test system. Relative Liver Wet Weight of all animals was calculated. Results: Progressively degenerative changes in morphological observations (disruption of cell plates in liver lobules and Kupffer cell hyperplasia), progressively increased statistical significance of morphometric (numerical density of Kupffer cells on area - Nak), and biochemical parameters informed that increasing liver damage was present with increased repetition of heat exposures in 2 and 5 days heat exposed experimental albino rats. With this liver degeneration, Relative Liver Wet Weight of all the experimental animals should have been decreased but it was not, reiterating about well-known fact of regenerative ability of liver. Along with progressive changes of heat induced liver injury, progressively increasing regenerative changes were also evident on morphological (binucleate cells and anisocytosis) observations supported by statistically significant morphometric (volume density of hepatocytes – Vvh and numerical density of hepatocytes - Nvh) parameters in experimental animals. Conclusion: The above findings suggested that the regenerative ability of liver progressively increased with progressively increasing liver injury.

Assessment of liver damage in male albino rats after repetitive heat stress of moderate level

Background: There are multiple studies showing the effect of severe heat stress on systemic functions. Severe heat stress has been known to affect almost every organ in the body. It is well proved that liver is the organ which is severely affected by heat stress and the biochemical, morphological, and morphometric changes of liver following severe heat stress are well documented. But, the effect of repetitive heat stress of moderate level on the liver has not been studied extensively. Aims & Objective: In the present study, the effect of repetitive heat stress of moderate level was assessed on biochemical [Serum Glutamic Pyruvate Transaminase (SGPT); Serum Glutamic Oxaloacetic Transaminase (SGOT); and Alkaline phosphatase (ALKP)], morphological, and morphometric changes of liver of adult albino male rats (wistar strain). Materials and Methods: The experimental animals were subjected to repetitive heat stress for 4 hours daily, at 37 ± 0.5oC in a Biological Oxygen Demand (BOD) incubator (relative humidity 65 - 82%) for 2, 5, and 10 consecutive days. Biochemical assessment (SGPT, SGOT, and ALKP) was done on blood collected from left ventricle of beating heart of rats. Morphometric and morphological studies were conducted under light microscope on paraffin sections (H&E) of liver from control and experimental animals. The morphometric analysis was done by intersection – point counting method, using simple square lattice test system. Results: The serum levels of liver enzymes were elevated in all heat exposed animals (statistically significant in five and ten days exposed animals) in comparison to controls. Morphological changes of anisocytosis at some sites, disruption of cell plates in lobules, mild Kupffer cell hyperplasia were present in rats exposed to heat for two consecutive days. After five days heat exposure ballooning degeneration, single cell necrosis along with small foci of necrosis disrupting cell plates in lobules, and sinusoidal compression were noticed. Kupffer cell hyperplasia was observed. At various sites, hepatocytes showed regenerative changes as binucleate cells and anisocytosis. After 10 days exposure, changes became more marked. The volume density of hepatocytes (Vvh) and numerical density of hepatocytes (Nvh) increased with the increase in heat exposure, despite increasing degenerative changes, confirming regenerative power of liver by hepatocyte proliferation. The increasing numerical density of Kupffers cells on area (Nak) indicated progressive liver damage. Conclusion: All the observations confirmed that exposure to repetitive heat stress, even of moderate level, leads to liver damage.

Bilateral Ovariectomy in Young Rats: What Happens in Their Livers during Cecal Ligation and Puncture Induced Sepsis?

Study ObjectivePediatric ovarian masses comprise a heterogeneous group of benign and malignant lesions. Surgical methods consist of emergency or programmed surgery with tumoral resection and uni/bilateral oophorectomy or salpingo-oophorectomy. We examined whether bilateral ovariectomy (OVX) worsens liver injury during the onset of cecal ligation and puncture (CLP)-induced sepsis in rats. DesignThe rat groups were: sham, bilateral-OVX, sepsis, and OVX-sepsis. SettingsAfter OVX operation, rats were allowed to recover for 12 weeks. At the end of recovery, CLP was applied 16 hours after sepsis induction. Main OutcomeThere was a significant difference in the numerical density of hepatocytes only between the sepsis and the OVX-sepsis groups. Serum ALT and AST were increased significantly in the OVX-sepsis group. NF-κB activation after OVX increased after induction of sepsis. OVX-sepsis group showed marked thrombosis in portal vein branches and the central vein, degeneration in the bile ducts, and widespread ischemic areas in liver sections. Intra-inflammatory cell invasion was observed in both the portal and intrasinusoidal areas. DiscussionThis study indicates that increases in liver NF-κB activity in ovariectomized rats following CLP-induced sepsis correlates with elevated levels of serum ALT and AST and with histopathologic changes in rat liver. Bilateral OVX therefore appears to play a role in the activation of NF-κB or in production of cytokines in liver cells. Thus, we provided novel insight into the effects of OVX on liver injury following CLP-induced sepsis.

Comparative study of three angiotensin II type 1 receptor antagonists in preventing liver fibrosis in diabetic rats: stereology, histopathology, and electron microscopy

The presence of liver disease in patients with progressively worsening insulin resistance may not be recognized until patients develop manifestations of the metabolic syndrome such as diabetes, hypertension, hyperlipidemia, and vascular disease. It was aimed to investigate whether three angiotensin II type 1 receptor antagonists (ARBs) (olmesartan, losartan, and valsartan) had preventive effect against hepatic fibrosis and this was a common characteristic among ARBs. In current study, 25 adult male rats were used and divided into five groups: the non-diabetic healthy group, alloxan induced diabetic (AID) control group, AID losartan group, AID valsartan group and AID olmesartan group. According to numerical density of hepatocytes, significant difference was found between the non-diabetic healthy group and diabetic control group. All treatments groups were significant when compared to diabetic control group. In diabetic control group it was examined swelling, irregular cristae arrangement in some of mitochondria. It was also determined mitochondria membrane degeneration in some areas of section profiles. In diabetic rats treated with losartan group, there were necrotic hepatocytes. In diabetic rats treated with valsartan group, predominantly, findings were similar to losartan group. In diabetic rats treated with olmesertan group, plates of hepatocytes were quite regular. There were hardly necrotic cells. Not only other organelles such as RER, SER and lysosom but also mitochondrial structures had normal appearance. In the diabetic control group electron microscopy revealed edema in both the cytoplasm and perinuclear area and the nuclear membranes appeared damaged. In conclusion, it was established that the most protective ARB the liver in diabetic rats was olmesartan, followed by losartan.

The protective effect of beta-1,3-D-glucan on taxol-induced hepatotoxicity: a histopathological and stereological study

The present study was undertaken to determine the histopathological and quantitative effects of the antineoplastic agent, taxol, on the liver. The protective effects of the strong antioxidant, β-1,3-D-glucan, against liver damage induced by taxol were also investigated. Mice were divided into four main treatment groups: control, taxol, β-1,3-D-glucan, and taxol+β-1,3-D-glucan. Each group was further subdivided into six subgroups, according to time of sacrifice (6, 12, 24, and 48 hours and 7 and 14 days). After the experiments, quantitative and histopathological changes in liver were examined by light microscopy and modern stereological systems. Stereological results indicated that the portal triad area of the taxol group was significantly reduced, compared to the controls at 12 hours, whereas in the taxol plus β-glucan and β-glucan groups, the means were similar to those of the controls. There was no statistically significant difference in the numerical density of hepatocytes with time between the control and other groups. The histopathological results indicated an increased, time-dependent degeneration and necrosis of the liver tissues in mice in the taxol group. Regenerative changes in livers of mice in the taxol plus β-glucan group were observed, when compared with those of the taxol group. Stereological and histopathological results suggest that β-glucan may reduce taxol-induced hepatic damage by blocking the change in the portal area and suppressing processes leading to necrosis.

Normalization of hepatic lysosomal autophagy in streptozotocin diabetic rats after pancreatic transplantation

This study was performed to determine whether the enhanced hepatic autophagocytosis occurring in diabetes mellitus could be reversed by pancreatic transplantation despite the persistence of hyperglucagonemia in transplant recipients. Twenty weeks after pancreatic transplantation, hepatic lysosomes and autophagic vacuoles were quantitated morphometrically in untreated streptozotocin-diabetic rats and in streptozotocin-diabetic rats treated by pancreatic transplantation. Hyperglycemia and hypoinsulinemia in untreated diabetic rats were corrected after pancreatic transplantation. However, the peripheral plasma glucagon concentration remained significantly higher in transplant recipients than in non-diabetic controls. Light microscopic morphometry revealed no significant effect of the diabetic state or its reversal on the volume of the single hepatocyte or the volume density and numerical density of hepatocytes. However, electron microscopic examination showed that the number and volume density of lysosomes and autophagic vacuoles, which were significantly increased in diabetic rats, returned to control values after pancreatic transplantation. It is concluded that chronic hyperglucagonemia does not preserve enhanced hepatic autophagocytosis when the diabetic hypoinsulinemia is corrected by the pancreatic transplant.

Chlordecone-induced potentiation of carbon tetrachloride hepatotoxicity: A morphometric and biochemical study

The present study, conducted over a time course of 36 hr after CCl 4 administration, describes sequential morphometric and biochemical changes which occur in livers of rats exposed to a combination of low levels of chlordecone (10 ppm for 15 days) and a single ip injection of CCl 4 (0.1 ml/kg). Those changes were compared to hepatic alterations which occur in rats that received the same dose of chlordecone or CCl 4 alone. Biochemical studies showed only trivial increases in levels of glutamic-pyruvic transaminase (GPT), glutamic-oxalacetic transaminase (GOT), and moderate but temporary increases in isocitrate dehydrogenase (ICD) after CCl 4 alone. The combination of chlordecone and CCl 4 resulted in significantly greater elevations of all three serum enzymes at all time intervals examined. Morphometric data showed no difference between normal diet controls and animals exposed to chlordecone alone as far as numerical density of hepatocytes or volume densities of hepatocytes with glycogen, lipid, dilated rough endoplasmic reticulum (RER), pyknosis, or mitoses. Morphometric analysis of livers from animals that received CCl 4 alone showed decreases in numerical density, temporary decrease in precentage of hepatocytes containing glycogen, an increase in hepatocytes containing lipid, temporary increase in hepatocytes with dilated RER, and temporary increases in pyknotic nuclei. Soon after the initial hepatic injury was histologically evident between 4 and 6 hr, the number of mitoses increased dramatically and this progressed until complete recovery from CCl 4 damage. From all indices of damage, complete recovery was evident by 36 hr after CCl 4 administration. Morphometric analysis of livers from rats that received the chlordecone + CCl 4 combination showed decrease in numerical density, consistent and progressive decrease in percent of hepatocytes containing glycogen, progressive increase in hepatocytes containing lipid, progressive increase in cells with dilated RER, and a progressive increase in cells with pyknotic nuclei. Number of mitoses remained suppressed, in notable contrast to the animals receiving CCl 4 alone. These studies suggest that two aspects of chlordecone potentiation of CCl 4 hepatotoxicity might be of mechanistic interest: first, the initial, progressive, and remarkably greater CCl 4 injury in chlordecone-treated animals, and second, the mechanism for the suppression or prevention of hepatocellular repair and renovation, which leads to complete recovery of animals receiving CCl 4 alone while leading to total hepatic failure and death of animals receiving the combination treatment.

Effects of the type of dietary fat at two levels of vitamin E in Wistar male rats during development and aging. III. Biochemical and morphometric parameters of the liver

The purpose of this study was to explore in rats the possible influence of the type of dietary fat at two extreme levels of vitamin E on several biochemically determined hepatic changes and on a number of quantitatively analyzed structural and ultrastructural variations with age in hepatic cells. Six groups of weanling Wistar male rats were fed ad libitum isoenergetic diets containing similar amounts (15 g per 100 g diet) of saturated fat (coconut oil), unsaturated fat (safflower oil) or a combination of both at two levels of dl-α-tocopherol (2 or 200 mg per 100 g of diet). Determinations were performed in rats killed at 3, 6, 12, 18 and 24 months. Although in relation to age and irrespective of the type of diet, several of the biochemical parameters fluctuated with time, comparisons of the results between the youngest and oldest rats showed no changes in the levels of hepatic RNA, phospholipids, cholesterol, total tocopherols and total collagens, significant increases in DNA and triglycerides and a significant decrease in total protein. While the type of diet did not have in general significant influences on the levels of DNA, RNA, total protein and collagens, either the type of dietary fat and/or the levels of vitamin E had some definite effects on the levels of triglycerides, cholesterol, phospholipids and total tocopherols, as well as on the in vitro formation of malonaldehyde and on the eventual occurrence of in vivo lipoperoxidation (diene conjugation). These effects, however, varied in relation to the duration of the diverse dietary treatments. The morphologic studies indicated that all the livers had variable but generally moderate degrees of fatty changes (mainly due to triglyceride accumulation) which were attributed to the moderate obesity found in the rats. The mean nuclear and cell dimensions of hepatocytes, the number of binucleated hepatocytes, surface density of rough endoplasmic reticulum, numerical density of mitochondria and the fractional cytoplasmic volume occupied by lipofuscin pigment in hepatocytes were not significantly affected by the type of diet, by age or by the eventual occurrence of in vivo hepatic lipoperoxidation, whereas the numerical density of hepatocytes (mono- and binucleated) and “litoral cells” (endothelial, Kupffer and Ito cells), although unaffected by diet, significantly increased with age. On the other hand, the fractional volume of mitochondria and peroxisomes, as well as the numerical density of peroxisomes, were significantly influenced by the type of dietary fat and to lesser extent by the dietary levels of vitamin E.