Lack of toxicity of hydroethanolic extract from Mitragyna inermis (Willd.) O. Kuntze by gavage in the rat

In traditional medicine in Mali, extracts derived from Mitragyna inermis (Willd.) O. Kuntze (Family: Rubiaceae) are commonly used to treat malaria. The antimalarial activity and the lack of genotoxicity in vitro and in vivo have been demonstrated in previous studies. Acute and chronic evaluation of the toxicity of the hydroethanolic extract of Mitragyna inermis leaves was performed in this study, according to the recommendations (cahier de l'Agence no. 3) of the French Drug Office. Two dosages (300 mg/kg and 3 g/kg) were given in one single administration by gavage to male and female rats. No animal died and no behavioral signs of acute toxicity were observed. Chronic toxicity studies over 28 days showed no changes in body weight and no macroscopic abnormality in the 14 organs examined after the animals were sacrificed. With the 3 g/kg/d drug dosage (100-fold higher than those proposed in man), only slight histological abnormalities were observed. Statistically significant differences, compared to control animals, in the weight of some organs and the values of some haematological or biochemical parameters were observed. However, these values always remained in the range given by the breeder for naive animals of the same strain. These investigations thus seemed to indicate the safety of repeated oral administration (up to 3 g/kg/d) of the hydroethanolic extract of Mitragyna inermis leaves, which can therefore be continuously used with safety by the African population in traditional treatment of malaria.

Immunohistochemical detection of C-100 hepatitis C virus antigen in formaldehyde-fixed paraffin-embedded liver tissue. Correlation with serum, tissue and in situ RT-PCR results

We localized HCV C-100 protein in liver biopsies of 15 patients with chronic hepatitis C using immunohistochemistry. The results were compared to serum, tissue extract analysis of HCV RNA and in situ RT-PCR described in a previous study. HCV was detected in 80% of the sera tested, in 40% of the tissue extracts and in 80% and 60% of the tissue sections tested by immunohistochemistry and in situ RT-PCR respectively. Compared to the serum positive cases, 83% and 67% of the cases were respectively positive with immunohistochemistry and in situ RT-PCR and 41% were positive with tissue extract detection. Compared to the tissue extract positive cases, 25% and 50% of the cases were respectively positive with immunohistochemistry and in situ RT-PCR. Finally, 75% of the cases positive by immunohistochemistry were also positive by in situ RT-PCR. These results underline the complementarity of the different methods for the precise diagnosis of hepatitis C.

Evaluation of glycogen loss in human liver transplants. Histochemical zonation of glycogen loss in cold ischemia and reperfusion

To find a prognosis model of human liver transplant, we evaluate 62 surgical biopsies for the loss of glycogen and its variations in relation to cold ischemia, reperfusion, lobular zonation and donor's ages. We applied univariate, multivariate and discriminant analysis and logistic regression. There was a clear lobular zonation of glycogen during cold ischemia and at reperfusion. During cold ischemia, the mean loss was 48% in periportal zones and 74% in pericentrilobular zones. At reperfusion, it was in the range of 60% in periportal zones and 95% in pericentrilobular zones. It was observed in 64% of the grafts for an ischemia time less than 10 hr and in 82% of the grafts for an ischemia time of 10 hr or more. It was increased by 90% at reperfusion with pericentral predominance. Donors' age was an aggravating factor of glycogen loss beyond 28 years of age. In conclusion, in periportal zones, mean global glycogen depletion was about 54% during cold ischemia and reperfusion. It decreased by 90% at reperfusion with pericentral predominance. Logistic regression has allowed modelization of cold ischemia and reperfusion.

Hepatitis C virus RNA detection by in situ RT-PCR in formalin-fixed paraffin-embedded liver tissue. Comparison with serum and tissue results

The purpose of this study was to localize HCV RNA in formalin-fixed paraffin-embedded liver biopsies of 15 patients with chronic hepatitis C using in situ RT-PCR method. The results were compared to serum and tissue extract analysis of HCV RNA. HCV RNA was detected in 80% of the sera tested, in 40% of the corresponding hepatic tissue extract and in 60% of the tissue sections tested by in situ RT-PCR. Compared to the serum positive cases, 67% of the cases were positive with in situ RT-PCR and 41% were positive with tissue extract detection. 50% of the cases in situ RT-PCR positive were also positive with tissue extract detection. These results underlined the complementarity of the different methods of viral detection for the precise diagnosis of hepatitis C.

Effect of ischemia-reperfusion on bile canalicular F-actin microfilaments in hepatocytes of human liver allograft: image analysis by confocal laser scanning microscopy

We studied and quantified the effect of ischemia-reperfusion on hepatic F-actin on bile canalicular and basolateral membranes in human liver allografts by means of confocal laser scanning microscopy imaging. The phalloidin-FITC staining of F-actin was normal in liver hepatocytes before reperfusion but decreased significantly after reperfusion (by 25% of controls). These results indicate that hepatic F-actin alteration is produced during the reperfusion phase. This modification, probably induced by reactive oxygen species, could impair bile canalicular contraction and tight junction permeability and consequently bile secretion in the postoperative period.

Central neurocytoma: 2 case reports and review of the literature

Central neurocytoma is a rare benign tumor of the central nervous system occuring in young adults and typically located in the ventricles. The tumor is composed of small round cells with neuronal differentiation and has a favourable prognosis. We report two cases of giant central neurocytomas with a triventricular extension in two young women. The first case concerned a 26 years old righthanded woman in whom an intraventricular mass was discovered, after a car accident with head trauma. Skull radiography showed an enlargment of the sella turcica. A CT scan performed in order to examine the pituitary gland revealed a voluminous and heterogenous intraventricular tumor with calcification. The second case concerned a 26 years old righthanded woman, presenting with a 4 Glasgow Coma Scale Score preceded by an acute onset of headache with projectile vomiting. A CT scan performed in emergency revealed a voluminous intraventricular mass with significant hydrocephalus. We review the different pathological and topographical patterns of previously published neurocytomas and discuss surgical management, effectiveness of radiation therapy and biological behavior.

Effects of digoxin on chemoreflex in patients with chronic heart failure

The effects of digitalis on the baroreflexes in human chronic heart failure have been well studied. Similarly, since it has been recently shown that chemoregulation remains generally effective during cardiac failure, the goal of this study was to evaluate the effects of a chronic administration of digoxin on the chemoreflexes. Hemodynamic and blood gas parameters were assessed in 7 patients with chronic congestive heart failure before and after chronic administration for 10 days of digoxin therapy (0.25 mg daily). In both situations measurements were performed 1/ in baseline conditions at room air and, 2/ after inhalation of pure O2 for 30 min, in order to inhibit the activation of the chemoreflexes. At room air, acute O2 inhalation resulted in a significant decrease in heart rate and cardiac output. After digoxin therapy, comparatively to pre-treatment values, cardiac output, stroke volume and PaO2 were significantly higher while heart rate, systemic resistance and pulmonary wedge pressure were lower. Furthermore, acute O2 inhalation did not modify heart rate or any hemodynamic variables. These results suggest that after digoxin therapy chemoreflex was no more activated in these patients. This effect may be related to the sympatho-inhibitory and to the positive inotropic effects of digoxin: improving hemodynamic and blood gas parameters may result in the inactivation of the reflex.

Quantitative analysis of glycogen content in hepatocytes of human liver allograft after ischemia and reperfusion

In order to examine glucose metabolism in liver grafts after cold ischemia and reperfusion, the heterogeneous lobular distribution pattern of glycogen content was studied using histochemical quantitative analysis. In most of the cases, this heterogeneous pattern of glycogen was observed after preservation and reperfusion. However, a 42% reduction of glycogen content, expressed as the ratio between stained surface and total surface of liver biopsies, was observed in biopsies after reperfusion. Moreover, both periportal and centrilobular hepatocytes showed a significant decrease in mean optical density after reperfusion (18% and 25%, respectively). The comparison of our results to early postoperative liver function tests and cold ischemia times showed no significant correlation (p<0.05).

Hepatotoxic effect of metallic pollutants on enzyme histochemical activities of yellow-legged gull Larus cachinnans michahellis liver

We studied the hepatotoxic effect of heavy metals (cadmium, mercury, copper) on Mg2+ -ATPase, NADH diaphorase, succinic dehydrogenase and acid phosphatase of yellow-legged gull liver, using enzyme histochemical methods. The lysosomal enzyme activity of acid phosphatase was increased in all cases. However, the other enzyme activities appeared to be insensitive to the different metallic pollutants and to their respective levels, in contrast with literature experimental data showing plasma membrane and mitochondrial alterations. This controversy could be explained by the differences in dietary conditions and metal overloads. The molecular basis of the toxicities of metallic pollutants is discussed.

Effect of dietary lipid (soybean lecithin and triacylglycerol) on hepatic F-actin microfilaments in cyclosporine A-treated rats: image analysis by confocal laser scanning microscopy

We studied and quantified the effect of cyclosporine A on hepatic F-actin on bile canalicular and basolateral membranes in rats fed either soybean lecithin, triacylglycerol-enriched diet, or low-fat diet by means of confocal laser scanning microscopy imaging. The phalloidin-FITC staining of F-actin was quite normal in the lecithin-cyclosporine A group but decreased significantly in the other cyclosporine A-treated groups (by 40% and 25% of control in triacylglycerol-cyclosporine A and cyclosporine A groups, respectively). The alteration of F-actin by cyclosporine A, related to cholestasis evidenced by a decrease in bile salt secretion, was prevented by dietary soybean lecithin and amplified by dietary soybean triacylglycerol.

Effect of ischemia-reperfusion on the heterogeneous lobular distribution pattern of glycogen content and glucose-6-phosphatase activity in human liver allograft

In order to examine glucose metabolism in liver grafts after cold ischemia and reperfusion, the heterogeneous lobular distribution pattern of glycogen content and glucose-6-phosphatase activity was studied using histochemical methods. The characteristic heterogeneous lobular distribution pattern of glycogen and glucose-6-phosphatase was maintained after preservation and reperfusion. However, it appeared that glycogen content decreased in both periportal and centrilobular hepatocytes after reperfusion. The glycogen decrease was higher in periportal hepatocytes. Glucose-6-phosphatase activity was maintained after reperfusion in most of the cases in periportal hepatocytes. In centrilobular hepatocytes, more cases showed a decrease in enzyme activity. It is suggested that ischemia-reperfusion mainly affects the glycogen content in both periportal and centrilobular hepatocytes and that centrilobular glucose-6-phosphatase activity is more sensitive to ischemia-reperfusion injury than periportal hepatocytes.

Effect of dietary lipids on hepatic Na+,K(+)-ATPase in cyclosporine A-treated rats: immunocytochemical analysis of alpha1 subunit by confocal laser scanning microscopy imaging

We studied the effect of dietary soybean lecithin or triacylglycerol on hepatic Na+,K(+)-ATPase in cyclosporine A-treated rats by means of quantitative immunocytochemistry. Cyclosporine A-treated rats were fed lecithin or a triacylglycerol-enriched diet or a low-fat diet. As a control, one group was only fed the low-fat diet; the three other groups were treated with cyclosporine A solvent and received the low fat, lecithin, or triacylglycerol diet. Bile canalicular staining significantly decreased in all cyclosporine A-treated groups with the higher values in lecithin-fed rats. In basolateral membranes, no decrease was observed in the lecithin-cyclosporine group, in contrast to the other groups. The triacylglycerol-cyclosporine group had lower values in both membrane domains. The alteration of Na+,K(+)-ATPase by cyclosporine A was related to cholestasis evidenced by a decrease in bile salt secretion. These modifications were prevented by dietary soybean lecithin and amplified by dietary soybean triacylglycerol.

A quantitative immunocytochemical study of Na+,K+-ATPase in rat hepatocytes after STZ-induced diabetes and dietary fish oil supplementation

Because diabetes causes alterations in hepatic membrane fatty acid content, these changes may affect the Na+,K+-ATPase. In this study we documented the effects of streptozotocin (STZ)-induced diabetes on hepatic Na+,K+-ATPase catalytic alpha1-subunit and evaluated whether these changes could be normalized by fish oil supplementation. Two groups of diabetic rats received fish oil or olive oil supplementation. Both groups had a respective control group. We studied the localization of catalytic alpha1-subunit on bile canalicular and basolateral membranes using immunocytochemical methods and confocal laser scanning microscopy, and the Na+, K+-ATPase activity, membrane fluidity, and fatty acid composition on isolated hepatic membranes. A decrease in the alpha1-subunit was observed with diabetes in the bile canalicular membranes, without changes in basolateral membranes. This decrease was partially prevented by dietary fish oil. Diabetes induces significant changes as documented by enzymatic Na+,K+-ATPase activity, membrane fluidity, and fatty acid content, whereas little change in these parameters was observed after a fish oil diet. In conclusion, STZ-induced diabetes appears to modify bile canalicular membrane integrity and dietary fish oil partly prevents the diabetes-induced alterations.

Modification of Ca2+, Mg2+-ATPase and F-actin distribution in hepatocytes of cyclosporine A treated rats. Effect of soyabean lecithin and triacylglycerol

We studied the effect of cyclosporine A on hepatic Ca2+, Mg2+-ATPase and F-actin on bile canalicular and basolateral membranes in rats fed either soyabean lecithin, or triacylglycerol enriched diet, or low fat diet. Ca2+, Mg2+-ATPase histochemical activity was not modified in lecithin-cyclosporine A group, whereas the activity was decreased in the other groups. The triacylglycerol-cyclosporine A group had the lower activity. The histochemical staining of F-actin was quite normal in lecithin-cyclosporine group but decreased in the other cyclosporine A treated groups. The lower staining was observed in the triacylglycerol-cyclosporine group. The alteration of Ca2+, Mg2+-ATPase and F-actin by cyclosporine A, related to cholestasis evidenced by a decrease in bile salt secretion, were prevented by dietary soyabean lecithin and amplified by dietary soyabean triacylglycerol.

Analysis by confocal laser scanning microscopy imaging of undilated bile canaliculi F-actin staining in the hepatocytes of human extrahepatic cholestatic liver

Many studies have demonstrated the role of bile canalicular microfilaments in bile secretion and bile flow. It is now admitted that modification of bile canalicular network of microfilaments play a role in dysfunction of bile secretion observed in many cases of cholestasis. This work intends to study F-actin, a major component of microfilaments, in human hepatocytes in extrahepatic cholestasis. Normal and extrahepatic cholestatic liver were studied. F-actin was stained with fluorescent phallotoxin and quantified by using confocal laser scanning microscopy and an image analysis method. Mean specific fluorescence (MSF) of bile canaliculi was measured. Since dilated and bile plugged canaliculi were rarely observed in cholestatic liver sections, only undilated bile canaliculi were analysed. Bile canalicular MSF was significantly increased (p < 0.05) in cholestatic hepatocytes (1.3 to 1.7 fold higher than in controls). These data demonstrate a pericanalicular thickening of F-actin microfilaments in human extrahepatic cholestatis, similar to that described in literature in many cases of human intrahepatic and extrahepatic cholestasis cases as well as in experimentally induced cholestasis. However, further studies are needed to understand this increase in F-actin pericanalicular microfilaments in human extrahepatic cholestasis.