A longevity study with enhancer substances (selegiline, BPAP) detected an unknown tumor-manifestation-suppressing regulation in rat brain.

AIMS: First proof to show that (-)-deprenyl/selegiline (DEP), the first selective inhibitor of MAO-B, later identified as the first ß-phenylethylamine (PEA)-derived synthetic catecholaminergic activity enhancer (CAE) substance and (2R)-1-(1-benzofuran-2-yl)-N-propylpentane-2-amine (BPAP), the tryptamine-derived presently known most potent, selective, synthetic enhancer substance, are specific markers of unknown enhancer-sensitive brain regulations. MAIN METHODS: Longevity study disclosing the operation of tumor-manifestation-suppressing (TMS) regulation in rat brain. Immonohistochemical identification of a fibromyxosarcoma in rats. Experiments with human medulloblastoma cell lines. Analysis of the mechanism of action of enhancer substances. KEY FINDINGS: Whereas 20/40 saline-treated rats manifested a fibromyxosarcoma, in groups of rats treated with 0.001mg/kg DEP: 15/40 rats; with 0.1mg/kg DEP: 11/40 rats (P<0.01); with 0.0001mg/kg BPAP: 8/40 rats (P<0.001); with 0.05mg/kg BPAP: 7/40 rats (P<0.01) manifested the tumor. Experiments with human medulloblastoma cell lines, HTB-186 (Daoy); UW-228-2, showed that BPAP was devoid of direct cytotoxic effect on tumor cells, and did not alter the direct cytotoxic effectiveness of temozolomide, cisplatin, etoposide, or vincristine. Interaction with distinct sites on vesicular monoamine-transporter-2 (VMAT2) is the main mechanism of action of the enhancer substances which clarifies the highly characteristic bi-modal, bell-shaped concentration-effect curves of DEP and BPAP. SIGNIFICANCE: Considering of the safeness of the enhancer substances and the finding that DEP and BPAP, specific markers of unknown enhancer sensitive brain regulations, detected the operation of an enhancer-sensitive TMS-regulation in rat brain, it seems reasonable to test in humans low dose DEP or BPAP treatment against the spreading of a malignant tumor.

Examination of claudin-1 expression in patients undergoing liver transplantation owing to hepatitis C virus cirrhosis.

The cell adhesion molecule claudin-1 (CLDN-1) is a well known co-factor for the cell entry of hepatitis C virus (HCV). We examined 24 hepatic biopsies from liver transplant patients. Reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry were performed according to standard procedures. RT-PCR results were shown as relative expression (ΔCT) with beta-actin as the reference gene. Immunohistochemistry results are shown by morphometry. The CLDN-1 mRNS expression rate was significantly lower when the patient displayed favorably with an unsatisfactory to antiviral therapy 0.756 ± 0.249 versus 1.304 ± 0.28 (P=.012). There was also a strong positive correlation between CLDN-1 protein expression and liver fibrosis (Pearson correlation coefficients: r=0.476; P=.034).

Claudins as diagnostic and prognostic markers in gynecological cancer.

Claudins are the main protein components of tight junctions (TJs) which function as selective barriers by controlling paracellular diffusion, maintain cellular polarity and play a role in signal transduction. The expression pattern of the 24 known members of the claudin family proved to be organ and tissue specific. The up- or downregulation of individual claudins has been described, especially during carcinogenesis. A significant increase of claudins-1 and -7 was detected in premalignant cervical lesions and invasive cancer compared with normal cervical epithelia. Claudins-3 and -4 were elevated in endometrial cancer. Claudin-1 overexpression characterized type II (seropapillary) endometrial carcinoma, while claudin-2 was elevated in type I (endometrioid) carcinoma. Claudins-3 and -4 were highly expressed in serous ovarian carcinoma. The expression data on claudins in different premalignant and malignant alterations suggest that these proteins might serve as diagnostic and prognostic markers and might be targets for future therapy.

Claudin-5 protein is a new differential marker for histopathological differential diagnosis of canine hemangiosarcoma.

AIMS: Claudin-5 protein is an endothel-specific claudin, present in tight junctions. To evaluate its usefulness as a differential diagnostic marker of canine hemangiosarcomas, the expression of claudin-5 molecule was studied in different canine tumours of vascular origin. METHODS AND RESULTS: Ninety two canine neoplastic tissue samples obtained from necropsies and biopsy specimens were routinely processed and stained immunhistochemically for claudin-5. The neoplastic endothelial cells of canine hemangiosarcomas, hemangiomas, and lymphangiomas showed a strong membrane immunoreactivity for claudin-5, but the other investigated canine malignant and benign tumours, including fibrosarcomas, myxo-, leiomyo-, cardiac rhabdomyo-, neurofibro-, synovial-, osteo-, and chondrosarcomas, spindle cell melanomas, hemangio-pericytomas, benign fibroblast proliferations, and leiomyomas were negative for this endothelial marker. In these non-vascular canine tumours intense immunostaining was detected in the endothelial cells of the incorporated intratumoural vessels and neovasculature. The canine splenic hematomas induced by hemangiosarcomas were distinguished from splenic hematomas induced by non-neoplastic lesions by the means of claudin-5 protein. In hemangiosarcomas the percentage of positive neoplastic endothelial cells was higher, and stronger when using the claudin-5 molecule compared to CD31 and vWf. CONCLUSION: The results show that claudin-5 molecule can be used as a new differential marker, and could also be of a diagnostic value in the differential diagnosis of canine hemangiosarcomas from sarcomas of other origin with hemorrhages or increased vascularization. Claudin-5 could help to reveal neoplastic proliferation of endothelial cells causing splenic hematomas and differentiate these tumours from non-vascular neoplastic splenic lesion. The immunohistochemical detection of the claudin-5 protein had a higher sensitivity than CD31, and vWf antigen in case of canine hemangiosarcomas.

Localization of hepatitis C virus RNA on human erythrocytes by RT in situ PCR technique.

BACKGROUND: Our previous results showed that hepatitis C virus (HCV) is detectable on erythrocytes by RT in situ PCR. The aims of the present study were to compare the sensitivity of this erythrocyte in situ PCR to routine serum solution phase HCV PCR as well as to obtain more data about the binding and cellular localization of HCV in the erythrocyte. METHODS: 105 previously HCV-infected patients and 20 control individuals were studied using RT in situ PCR on erythrocytes and solution phase RT-PCR from serum samples. Binding of HCV to erythrocytes was studied by in vitro inoculation. RT in situ PCR results were evaluated by fluorescence and confocal laser scanning microscopy. RESULTS: From 105 HCV cases, 78 gave positive, while 5-and all control cases-gave negative results by both PCR techniques. In 21 cases, only the in situ technique provided positive results, while in only I case did the solution phase method provide positive results. During in vitro inoculation, an early HCV-erythrocyte binding was detected followed by virus internalization. CONCLUSIONS: Erythrocyte-in situ PCR was found to show higher sensitivity for the detection of HCV compared to the generally applied serum PCR method. In vitro studies suggested a specific binding of HCV to erythrocyte and showed the virus to be capable of internalization.

Hepatitis viruses and hepatocarcinogenesis.

Hepatocellular carcinoma (HCC) is among the most frequent malignancies worldwide. Hepatitis viruses, such as the hepatitis B virus (HBV) and hepatitis C virus (HCV) are undoubtedly listed in the etiology of HCC. Studies show that, in the near future, viral hepatitis will carry increasing weight in the etiology of HCC. This review briefly discusses the known carcinogenic effects of HBV and HCV in the light of experimental and human studies. The data show that viral proteins may directly interfere with gene products responsible for cell proliferation and cell growth. Many other signal transduction cascades may be affected as well. Direct integration of HBV viral sequences into the host genome increases the genomic instability. The genomic imbalance allows the development and survival of malignant clones bearing defected genomic information. HBV and HCV infection induces indirect and direct mechanisms through cellular damage, increased regeneration and cell proliferation, therefore enhancing the development of HCC.

[Papillary renal cell carcinoma]. / Papillaris vesesejtes veserák.

The authors present a case of a papillary type renal cell carcinoma. The tumor is mostly discovered accidentally; a histopathological evaluation is indispensable for an exact diagnosis. Because of a better prognosis, differentiation of this tumor type from the classic variant of renal cell carcinoma is necessary, however, the contralateral appearance of a second tumor is not to be excluded, which necessitates a strict patient follow-up. Prevalence of this tumor is higher in patients with chronic dialysis.

[Acute pancreatitis with few symptoms and extensive necrosis]. / Akut pancreatitis tünetszegény, kiterjedt, távoli necrosisokkal.

The authors present a particular case of an acute pancreatitis. The disease developed in a young male patient following cholelithiasis and cholecystectomy. The inflammation affected the outer layers of the pancreas as a mantle and it caused widespread fat necrosis. Necrectomy for septic state was conducted to improve the condition, but the patient died of pulmonary embolism. Unexpectedly big necrotic areas of fat necrosis and abscess were found at autopsy.

Hepatocyte proliferation and cell cycle phase fractions in chronic viral hepatitis C by image analysis method.

OBJECTIVE: Chronic hepatitis is characterized by necrosis of liver cells, accompanied by an inflammatory reaction and compensatory cell proliferation. The interaction of the core and non-structural proteins of hepatitis C virus (HCV) with several cellular factors suggests that cell proliferation may be influenced by HCV. The aim of this study was to investigate hepatocyte proliferation and DNA ploidy patterns in patients with chronic viral hepatitis C (CH-C) compared with chronic non-viral hepatitis (CH-N), using a TV image analysis method. METHODS: The DNA index (DI) and cell phase fractions (G1, S, G2) were measured by means of digital picture analysis method on nuclear suspensions of Feulgen stained hepatocytes. Cells were taken from the liver biopsy specimens of 71 patients with CH-C and 24 patients with CH-N. Twenty-six normal liver samples were used as controls. RESULTS: Significantly higher G1 (94 +/- 4) and lower S (3.56 +/- 3.16) phase fractions were measured in CH-C compared with CH-N (G1, 90 +/- 6; S, 6.4 +/- 5.99). The DI of moderate (1.12 +/- 0.05) and severe (1.12 +/- 0.05) CH-C showed near-aneuploid DNA content, while diploidy (DI < 1.10) was detected in cases of CH-N. CONCLUSION: The higher G1 and lower S cell cycle phase fractions in CH-C reflect decreased hepatocyte proliferation compared with CH-N. The near-aneuploid DNA content of the HCV-infected liver samples may be a sign of increased genetic instability, which may contribute to the carcinogenic potential of HCV.

Expression of decorin, transforming growth factor-beta 1, tissue inhibitor metalloproteinase 1 and 2, and type IV collagenases in chronic hepatitis.

Decorin is a small extracellular matrix proteoglycan. It binds and modulates transforming growth factor (TGF)-beta 1 action, the major stimulator of fibrogenesis. Its role in the pathogenesis of human liver cirrhosis is unknown. Therefore, we studied the relationship of the 2 proteins in normal human liver and in 43 chronic hepatitis and liver cirrhosis specimens. To understand the mechanism that maintains matrix deposition in stage IV hepatitis, we studied expression of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2, as well as the activities of type IV collagenases. Gene expression was analyzed on messenger RNA and protein level by morphologic and biochemical approaches. Decorin proved to be an early marker of fibrogenesis, and its deposition increased parallel to that of TGF-beta 1 and to inflammatory activity. Liver fibrosis progressed despite high temporospatial expression of decorin with TGF-beta 1. Neither decorin nor TGF-beta 1 protein deposition increased further in cirrhosis with low inflammatory activity, suggesting that impaired extracellular matrix catabolism rather than active production plays a role in this stage. This possibility was supported by high message levels of metalloproteinase inhibitors, no 72-kd collagenase activities, and low 92-kd collagenase activities.

[Pathologic evaluation of orthotopic liver transplantation in Hungary]. / A hazai májtranszplantációk értékelése patológiai szempontból.

A total of 81 orthotopic liver transplantations were performed on 74 patients between January 1995 and December 1999 at the Department of Transplantation and Surgery of the Semmelweis University in Budapest. Indication for transplantation was liver cirrhosis in 57 cases, 10 patients were transplanted due to fulminant liver failure, while 7 patients underwent transplantation because of liver metastasis of different semimalignant tumours. During the above period, retrospective studies on 205 pre- and posttransplantation liver biopsies, 74 explanted livers, 7 explanted liver grafts and 22 autopsy cases were performed at the First Institute of Pathology and Experimental Cancer Research of the Semmelweis University in Budapest. A number of 116 protocol biopsies (dates as zero time, 7th day, 6th month and 12th month) and 73 non-protocol biopsies (taken due to liver allograft dysfunction) were analysed. Different gradings of acute rejection--characterised by trias of portal inflammation, venous endothelitis and bile duct damage--were detected in 62 cases. Chronic rejection occurred in 7 patients, with 4 cases of vanishing bile duct syndrome and one of the case of foam cell arteriopathy, add to 2 cases of chronic rejection characterized by undetermined bile duct damage. The present study includes the evaluation of 22 autopsy cases according to liver transplantation in Hungary, with the finding that liver allograft insufficiency was the main cause of mortality. Authors conclude that pathomorphological analysis has an important role in relation to liver transplantation.

Trabecular angiomyolipoma mimicking hepatic cell carcinoma.

Hepatic angiomyolipomas are rare tumors, especially in comparison with those occurring in the kidney. Nevertheless, it is important to be aware of their existence, especially when occurring in the liver, where they might have different subtypes. Not infrequently they are composed of rather irregular cells with epithelioid appearance. In these cases hepatocellular carcinoma or the possibility of other malignant tumors has to be ruled out, with the aid of numerous immunohistochemical reactions. The authors present a case of a female patient, whose liver lesion was first diagnosed on cytological examination as a hepatocellular carcinoma. Based on the preoperative cytological diagnosis, a large liver lobe resection was performed. Histological examination found an angiomyolipoma of the above-mentioned type, and the final diagnosis was ascertained with the aid of vimentin, smooth muscle actin (SMA), and HMB-45.

[Hepatocyte proliferation and DNA content in chronic hepatitis C]. / Hepatocyta-proliferáció és DNS-tartalom krónikus C-hepatitisben.

Apart from inflammatory reaction, the death of hepatocytes is also a characteristic of chronic hepatitis. Necroinflammation is followed by compensatory proliferation, which plays a rather important role in maintaining the liver function. Authors studied the DNA content of hepatocytes in patients with chronic hepatitis C, and determined the ratio of hepatocytes in phases G1, S and G2 to determine the hepatocyte proliferation and regeneration capacity of the liver. Liver biopsy samples were taken from 23 patients with chronic hepatitis C and from 16 with chronic hepatitis with non viral origin, from which nuclear suspension counts were done based on the histological slides. A total of 16 normal liver tissue samples served as control. The DNA index, G1, S, G2 and polyploid fraction were determined using the DNACE (Digital Image Analyzer for Nuclear Deoxyribonucleic Acid Content Estimation, KFKI/NIO, Hungary) digital imaging process. The DNA index was found to be significantly higher in the chronic hepatitis C than in the non-C group, with the verification of aneuploidy (DI > 1.10). The chronic non-C hepatitis cases showed lower G1 (88 +/- 6) and higher S (7.8 +/- 6.6) fractions. In comparison to the normal liver tissues, the chronic hepatitis C cases also revealed a significantly (p < 0.05) lower G1 (91 +/- 5) and a higher S (5.4 +/- 3.6) fraction, though staying behind the values found for the non-viral group. The deviation can be explained by the presentation of the HCV proliferation inhibitory effect. The polyploid cell fraction revealed a significantly higher value in the chronic non-viral cases as compared to the C virus group, reflecting on the decreased regeneration capacity of the liver. When comparing the HCV groups, significant differences were found between the mild and moderate cases in respect to the G1 and G2 fractions. At the same time, the moderate and severe cases showed statistical deviation regarding the DNA index. Chronic hepatitis C virus infection reduces the proliferation of hepatocytes and the regeneration capacity of the liver. The aneuploid DNA index reflects on genetic instability, which could be the basis of the malignant transformation of the cells.

Effect of hepatitis C virus on hepatocyte proliferation and DNA ploidy in patients with chronic hepatitis C.

Hepatitis C virus infection may act as a cofactor by inducing chronic hepatitis and cirrhosis, playing a promoting role in the multistep process of hepatocarcinogenesis by maintaining liver inflammation, hepatocyte necrosis and regeneration. The aim of this study was to measure the DNA ploidy and cell proliferation of hepatocytes in patients with chronic hepatitis C. Hepatocyte nucleus suspension was analyzed from 45 patients with chronic hepatitis C and from 27 patients with chronic hepatitis non-C. The histopathological pattern of chronic hepatitis samples/grade, stage/was investigated. A significantly lower cyclin A protein expression and cytometrically measured S-phase fraction was observed in chronic hepatitis C as compared to chronic hepatitis non-C, representing suppressed cell proliferation of virus infected cells. In the chronic hepatitis C groups, the S-phase fraction depression was moderate, the grade of inflammation and cyclin A protein expression were also decreased, mainly in the severe grade group. In chronic hepatitis non-C, the number of cyclin A staining-positive cells increased parallel with severity of the inflammation. In addition, the HCV infection caused a near diploid minimally aneuploid cellular DNA content in the cases of moderate and severe histological groups. In contrast, the cellular DNA content was consequently diploid-independent of histological grades in chronic hepatitis non-C. Our results suggest that in chronic viral hepatitis C, the hepatocyte proliferation is suppressed parallel with the degree of inflammation, while the DNA content becomes aneuploid. The aneuploidy is a sign of genetic instability, predisposing the affected cells to unbalanced chromosomal abnormality which finally leads to malignant transformation.

Decorin and actin expression and distribution in patients with chronic hepatitis C following interferon-alfa-2b treatment.

BACKGROUND/AIMS: Chronic hepatitis C can lead to cirrhosis and hepatocellular carcinoma. Interferon-alfa therapy may prevent the progression of the disease. The expressions of decorin and alfa-smooth muscle cell actin of the extracellular matrix play a central role in liver fibrosis. We set out to assess the expressions of these proteins in chronic hepatitis C patients, and to evaluate how they can be modified by interferon-alfa therapy. METHODS: Twenty chronic hepatitis C patients received interferon-alfa-2b therapy for 6 months (group I) or 12 months (group II). Liver biopsy samples were taken before and after the therapy. The alfa-smooth muscle actin-positive cells were determined with a monoclonal antibody, and decorin expression was detected with a polyclonal antibody. The cells were evaluated with a semiquantitative scoring method. For statistical analysis, non-parametric methods were used. RESULTS: Before the therapy, alfa-smooth muscle actin-labeled cells and marked decorin expression were present throughout all the acinar zones. Interferon-alfa-2b therapy resulted in significant decreases in both the number of alfa-smooth muscle actin-positive cells and the decorin expression. The alfa-smooth muscle actin-positive cells and decorin expression correlated with the histological activity index (R=0.72, p<0.03, R=0.68, p<0.05). CONCLUSIONS: This study demonstrates that a large number of alfa-smooth muscle actin-positive cells and a marked decorin expression are frequent findings in chronic hepatitis C. Treatment with interferon-alfa-2b for 12 months reduced the number of labeled cells and the decorin expression. The results suggest that interferon-alfa-2b is capable of interfering with fibrogenesis in an early and presumably still reversible phase of chronic hepatitis C.

Papillary microcarcinoma of the thyroid gland in renal transplant patients.

Among organ transplant recipients there is a world wide increase in the number of de novo tumors as well as a decrease in the time of the first appearance after the transplantation. Between 1973 and the 31st of August 1999 1709 cadaver renal allograft transplantations were performed in our Department. Four thyroid cancers were detected among the renal transplanted patients. Two of them proved to be papillary microcarcinomas. Although the elevated risk of thyroid cancers is well established in the literature papillary microcarcinomas have never been reported before in an immunosuppressed patient. Authors highlight that the thyroid gland should always be carefully checked in organ transplant recipients, since better survival might be achieved even in the immunosuppressed population. Metastatic tumor is relatively benign which is in correlation with the literature, but there has been little experience in organ transplanted patients so far.

Induction and peroxisomal appearance of gulonolactone oxidase upon clofibrate treatment in mouse liver.

Various antihyperlipemic peroxisome proliferators are known to be carcinogenic in rodents but not in human, other primates and guinea pig, which species lost their ability to synthesize ascorbate due to mutations in the gulonolactone oxidase gene. Ascorbate synthesis is accompanied by H2O2 production, consequently its induction can be potentially harmful; therefore, the in vivo effect of the peroxisome proliferator clofibrate was investigated on gulonolactone oxidase expression in mouse liver. Liver weights and peroxisomal protein contents were increased upon clofibrate treatment. Elevated plasma ascorbate concentrations were found in clofibrate-treated mice due to the higher microsomal gulonolactone oxidase activities. Remarkable gulonolactone oxidase activity appeared in the peroxisomal fraction upon the treatment. Increased activity of the enzyme was associated with an elevation of its mRNA level. According to the present results the evolutionary loss of gulonolactone oxidase may contribute to the explanation of the missing carcinogenic effect of peroxisome proliferators in humans.

[Severe relapse of hepatitis C following liver transplantation. Successful treatment with a combination of interferon-alpha and ribavirin]. / Hepatitis C súlyos relapsusa májátültetés után. Sikeres kezelés interferon-alpha és ribavirin kombinációval.

A 38-year-old, male patient, with end-stage HCV cirrhosis, underwent liver transplantation (OLT). After a sufficient recovery a rapid elevation of ALT and profound jaundice developed 3 months after OLT, together with a 15-fold rise of pre-transplant HCV RNS level. Liver biopsy was carried out, histology excluded rejection and signs of acute hepatitis were observed. Interferon alpha 2b 3 MU TIW and ribavirin 800 mg/day resulted in normalization of ALT, se. bilirubin and decrease of viral load by 90 per cent at the 3rd month of treatment. Improvement of hepatitis and no rejection was shown by control histology. A 6-month combination therapy followed by continuous ribavirin monotherapy maintains a permanent good condition with normal ALT, no icterus, a continuously low HCV RNA level and a mild chronic hepatitis with fibrosis in the liver histology 18 months after OLT. Danger of HCV reactivation after OLT, difficulties of diagnosis, interactions of immunostimulant and immunosuppressive drugs, advantages of combination therapy are discussed.