Biomedical subjects
Publications and source records attributed to V Paradis.
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BACKGROUND: Budd-Chiari syndrome (BCS) is associated with parenchymal changes leading to major architecture remodelling. In order to gain further insight into the pathogenesis of BCS, we investigated expression of a set of genes involved in the course of chronic liver diseases. METHODS: Quantitative expression of 35 selected genes involved in extracellular matrix regulation, growth factors, and angiogenesis was investigated in 13 cases of BCS and compared with 10 normal livers and 13 cirrhosis cases by real time reverse transcription-polymerase chain reaction. Differential gene expression was considered significant for genes showing at least a twofold variation, with p < 0.05. RESULTS: Expression of 14 genes was significantly increased in BCS versus normal liver, with the highest increase in superior cervical ganglion 10 (SCG10) gene. BCS cases were classified according to their evolution and morphological pattern as either acute or chronic in six and seven cases, respectively. Unsupervised hierarchical clustering of acute and chronic BCS cases on the basis of similarity in gene expression pattern led to distinction between the two groups. Expression of three genes was significantly different in acute versus chronic BCS (increase in matrix metalloproteinase 7 and SCG10, decrease in thrombospondin-1 for chronic BCS). Seventeen and 10 genes, mainly involved in extracellular matrix and vascular remodelling, were significantly deregulated in acute BCS versus normal liver and cirrhosis, respectively. CONCLUSION: These results show that BCS cases display a specific gene expression profile that is different from that of normal liver and cirrhosis; the molecular configuration of BCS can be readily distinguished by its evolution and morphological pattern.
BACKGROUND AND AIMS: Splanchnic vein thrombosis is a significant source of complications in candidates for liver transplantation. The aims of this study were: (a) to determine the prevalence of and risk factors for splanchnic vein thrombosis in cirrhotic patients awaiting transplantation and (b) to assess the usefulness of anticoagulation. METHODS: A total of 251 cirrhotic patients listed for transplantation were analysed. All underwent systematic screening for thrombosis with Doppler ultrasonography. During the second period of the study, all patients with thrombosis received anticoagulation up to transplantation while during the first period none had received anticoagulation. RESULTS: The incidence of splanchnic vein thrombosis at evaluation was 8.4%. Seventeen additional patients (7.4%) developed de novo thrombosis after evaluation. Independent risk factors for thrombosis were low platelet count (77.4 (36.3) v 111.6 (69.2) 10(9)/l; p = 0.001), a past history of variceal bleeding (47.4% v 29.1%; p = 0.003), and a prolonged interval from listing to transplantation (8.5 (6.8) v 4.8 (4.4) months; p = 0.002). The proportion of partial or complete recanalisation was significantly higher in those who received (8/19) than in those who did not receive (0/10, p = 0.002) anticoagulation. Survival was significantly lower in those who had complete portal vein thrombosis at the time of surgery (p = 0.04). CONCLUSION: These results support a systematic screening for splanchnic vein thrombosis in patients awaiting transplantation. They suggest that in these patients, anticoagulation is safe and has a significant impact on recanalisation as well as prevention of extension of thrombosis.
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Telomerase enzymatic activity has been detected in most human malignant tumours including hepatocellular carcinoma. In order to assess the cellular source, the topographic distribution, and the chronology of telomerase re-expression during human liver carcinogenesis, an in situ technique derived from the standard TRAP (telomeric repeat amplification protocol) assay was set up that allowed the detection of telomerase enzyme activity at the cellular level on frozen liver tissue sections. In situ TRAP (ISTRAP) was performed on 27 hepatocellular carcinomas (HCCs) and 57 non-tumour livers, including normal liver without HCC, liver samples adjacent to tumour with and without hepatic cirrhosis, and biopsies of chronic hepatitis. In HCC, telomerase was detected in the nuclei of liver tumour cells in 23/27 cases (85%), with a heterogeneous distribution within the tumour. This signal was also detected in clusters of hepatocytes in 16/26 (61%) samples of liver adjacent to HCC, in 10/23 (43%) cases of chronic viral hepatitis without adjacent HCC, and in scattered nuclei of 2/8 histologically normal livers. Comparison of the results obtained with ISTRAP and standard TRAP assays on tissue extracts suggests a gain in sensitivity with the in situ technique. This study confirms that telomerase is expressed in most HCCs and suggests that focal telomerase reactivation is an early event during human liver carcinogenesis. ISTRAP is a sensitive technique that allows the study of telomerase expression in the morphological context.
Human telomerase is a specialized reverse transcriptase that catalyses telomeric repeat addition at the ends of chromosomes. Activation of this enzyme is one of the key steps in cell immortalization and carcinogenesis, and one of its components, hTERT, is considered as the rate-limiting factor. While telomerase activity was found to be prognostically relevant in various cancers, results obtained from renal cell carcinomas (RCC) failed to show any correlation with the usual prognostic factors. The aim of the study was to reassess the role of telomerase and its hTERT component in the biological behaviour of RCC using new quantitative techniques, such as the quantitative evaluation of hTERT mRNA level by a real-time RT-PCR procedure and the measuring of telomerase activity by an ELISA TRAP assay. Since experimental evidence supports a relationship between cell proliferation or c-myc expression and telomerase, the proliferation index and c-myc mRNA levels were also studied. Forty-one RCC (29 conventional renal cell carcinomas (CRCC), 10 papillary RCC and two urothelial carcinomas) were studied. In 73% of cases, normalized hTERT mRNA expression was significantly higher in the tumour sample than in the normal tissue. Telomerase activity was detected in 63% of RCC, while corresponding normal tissue was always negative. Analysis of correlations showed firstly that both telomerase activity and hTERT mRNA level were lower in the group of CRCC versus non-CRCC (TRAP: 0.3+/-0.1 versus 0.6+/-0.2, p<0.05; hTERT/PO mRNA: 5+/-3 versus 37+/-8, p<0.001, respectively); secondly, that in the group of CRCC, hTERT mRNA expression level was correlated with the stage of the tumour (p=0.01); and thirdly, that no correlation was observed between c-myc mRNA level and hTERT mRNA level. In conclusion, these results support the involvement of telomerase in RCC and the potential interest of hTERT mRNA quantification.
Until now, no molecular parameter has been available for predicting the metastatic potential of prostate tumours, which leaves their outcome uncertain despite an apparent benign histology or early stage. Abnormal expression of adhesion molecules, such as E-cadherin, can be contributing factors for increased invasiveness and metastatic potential. Histological analysis for E-cadherin expression was carried out on paraffin-embedded tumour tissues. Tumour metastatic potential was indirectly evaluated by detecting circulating prostate cells (CPC), using reverse transciptase-polymerase chain reaction (RT-PCR) and prostate-specific membrane antigen (PSMA) as a target. Patients were followed-up for a median of 14 months (range 10--19 months) after surgery with serum prostate-specific antigen (PSA) level measurement. Interestingly, 23 of 44 localised tumours exhibited aberrant E-cadherin expression. Prior to primary surgery, PSMA RT-PCR detected the spread of prostate cells to the blood in 24 patients. Statistical analysis showed that abnormal E-cadherin expression in the tumours was the only variable that was independently correlated with prostate cell dissemination in the blood (P<0.0001). In logistic regression analysis, abnormal E-cadherin expression was a significant independent predictor for a later biological relapse. This impaired adhesion status was clearly correlated with a haematogenous spread of the primary tumour cells. It could therefore be an objective way to restrict the indications for radical surgery to patients not presenting with this feature.
There is growing evidence that senescent cells accumulate in vivo and are associated with the aging process in parallel with the progressive erosion of telomeres. Because recent data show that telomere shortening is involved in the pathogenesis of liver cirrhosis, we looked for replicative senescence cells in normal livers, chronic hepatitis C, and hepatocellular carcinoma (HCC). Replicative senescent cells were detected on liver tissue cryosections using expression of a specific marker, senescence-associated beta-galactosidase, a cytoplasmic enzyme detected at pH 6. A total of 57 frozen liver samples (15 normal liver, 32 chronic hepatitis C, and 10 HCCs) were studied. Replicative senescence was graded as absent in 56% of cases (32 of 57) and present in 44% (25 of 57). Replicative senescence was considered present in 3 of 15 normal livers (20%), 16 of 32 chronic hepatitis cases (50%), and 6 of 10 HCCs (60%). In the group of nontumoral livers, the presence of senescent cells in liver was associated with older age (P =.03). In the group with chronic hepatitis C, fibrosis stage, but not activity grade, was significantly correlated with the accumulation of replicative senescent cells (P <.001). Finally, beta-Gal staining in nontumoral tissue was strongly correlated with the presence of HCC in the surrounding liver (P <.001). These results suggest that chronic hepatitis C represents a relevant model of accelerated replicative senescence and that accumulation of replicative senescent cells predispose to HCC development. Detection of replicative senescent cells may then serve as a predictive marker of a hepatocellular carcinoma in the surrounding tissue. HUM PATHOL 32:327-332.
Nonalcoholic steatohepatitis (NASH) may progress to liver fibrosis and cirrhosis. Mechanisms directly involved in the development of fibrosis have been poorly investigated. Because connective tissue growth factor (CTGF) is an intermediate key molecule involved in the pathogenesis of fibrosing chronic liver diseases and is potentially induced by hyperglycemia, the aims of this study were to (1) study the expression of CTGF in vivo both in human liver biopsy specimens of patients with NASH and in an experimental model of obesity and type II diabetes (Zucker rats); and (2) analyze the effects of hyperglycemia and insulin in vitro on hepatic stellate cells. In vivo, CTGF overexpression was observed in the liver tissue of all of the 16 patients with NASH. CTGF immunostaining was mild in 7 cases (44%) and moderate or strong in 9 cases (56%). Staining was mainly detected in the liver extracellular matrix in parallel with the amount of liver fibrosis. Liver from fa/fa rats also showed CTGF overexpression by comparison with Fa/fa rats both at the messenger RNA (mRNA) level (3-fold increase) and protein level. In vitro, both CTGF mRNA and protein were significantly increased when hepatic stellate cells were incubated with either glucose or insulin. A slight increase in type I procollagen mRNA level was also observed in hepatic stellate cells incubated with glucose. In conclusion, this study suggests that hyperglycemia and insulin are key-factors in the progression of fibrosis in patients with NASH through the up-regulation of CTGF.
PURPOSE: We studied a series of superficial transitional cell carcinoma of the bladder to assess whether the Ki-67 labeling index predicts recurrence and progression in a cohort of patients treated by transurethral resection alone or receiving adjuvant intravesical bacillus Calmette-Guerin therapy (BCG). MATERIALS AND METHODS: From 1989 to 1990, we prospectively studied 70 consecutive cases of superficial transitional cell carcinoma of the bladder using Ki-67 immunostaining. The tumors were 43 pTa and 27 pTl. Thirteen were treated with transurethral resection only and 57 received adjuvant intravesical BCG. The median follow-up times was 64 months. The threshold index values of Ki-67 for recurrence and progression were determined using ROC curves. The relative predictive values of the Ki-67 labeling index and tumor characteristics for recurrence and progression were evaluated using Cox's proportional hazards model. RESULTS: A cutoff value of 13% was determined. The recurrence free survival rate at 5 years was 68% for cases with a Ki-67 labeling index of 13 or higher and 71% for those with an index of less than 13 (NS). The progression-free survival rate at 5 years was 43% in cases with an index of 13 or higher and 89% in those with an index of less than 13 (p<0.0001). Using multivariate analysis the Ki-67 labeling index is an independent risk factor for tumor progression with a relative risk of 4.61 (p<0.05). CONCLUSION: When BCG is used for high and intermediate risk superficial bladder cancers, the Ki-67 labeling index is an independent predictive factor of progression but not of recurrence.
Monoclonal immunoglobulin (Ig) deposition diseases are characterized by deposition in tissues of excessive amounts of the Ig, compromising organ functions. Light chain deposition disease (LCDD) and AL amyloidosis are the commonest [Buxbaum 1992]. LCDD is usually characterized by rapidly progressive renal failure with glomerular and tubular deposits of Ig fragments mostly composed by kappa light chain. Monoclonal Ig production can also be observed associated with various symptoms, that, taken together, have been described as the Crow-Fukase syndrome or POEMS syndrome. It associates polyneuropathy, organomegaly, endocrinopathy, monoclonal Ig, and skin changes. In POEMS syndrome, renal abnormalities are rare and are reported as a moderate renal insufficiency with mild proteinuria or acute functional renal insufficiency leading in some cases to end-stage renal failure [Fukatsu et al. 1991]. Although a monoclonal Ig is produced, no Ig deposit disease had been described in POEMS syndrome except a case of AL amyloidosis [Toyokuni et al. 1992]. Here, to our knowledge, we report the first case of an LCDD associated with a POEMS syndrome. Although an autologous bone marrow graft was realized, the monoclonal component reappeared and was responsible for end-stage renal disease, cachexia and death.
BACKGROUND: Recurrent hepatitis C virus (HCV) infection after liver transplantation is characterized by a high level of intrahepatic HCV replication and more severe liver damage in case of genotype 1b infection. We investigated the involvement of apoptosis in recurrent HCV liver disease, and its possible links with histological findings, HCV genotype, liver HCV RNA level, and liver Fas mRNA level. METHODS: We studied 61 liver graft biopsy specimens from 25 patients transplanted for HCV-related cirrhosis. DNA fragmentation was determined semi-quantitatively by in situ end labeling. HCV RNA and liver Fas mRNA were determined in parallel by quantitative polymerase chain reaction, with ribosomal 28S RNA as internal standard. RESULTS: Apoptotic lesions were predominantly portal (nonhepatocytic) or lobular (hepatocytic). Both were correlated with serum aminotransferase levels. The degree of portal apoptosis correlated with acute rejection (P<0.001), although lobular apoptosis was associated with lobular hepatitis (P<0.02), and HCV genotype 1b (P=0.04). In multivariate analysis, liver Fas mRNA level independently correlated with HCV-related chronic active hepatitis (P=0.04), age (P=0.01), and liver HCV RNA level (P=0.0007). CONCLUSIONS: After liver transplantation, 1) apoptosis is involved in HCV-related liver damage; 2) HCV type 1b may induce more severe apoptotic lesions than other genotypes; and 3) Fas transcription may be up-regulated by intrahepatic HCV replication.
We report three cases of a primary malignant lymphoma of the urinary bladder. The radiological features revealed a sessile mass of the lateral wall for one case, a circumferential thickening in the second, and two separated masses of the bladder wall in the last case. Primary malignant lymphoma of the urinary bladder is extremely rare. From a review of the literature, the clinical and radiological findings are discussed. In this paper we report the first case of urinary bladder lymphoma presented on CTas multiple masses.
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Vascular endothelial growth factor (VEGF) is an angiogenic factor that may be involved in tumor growth and metastasis. Only a few data concerning the role of VEGF in renal cell carcinomas (RCCs) are available, and no studies have yet evaluated its prognostic value. The aim of the present study was to assess VEGF expression in a large series of renal tumors with a long follow-up, correlated with the usual histoprognostic factors and survival. VEGF immunostaining was performed on formalin-fixed, paraffin-embedded archival tissue from 74 renal carcinomas (62 conventional renal cell and 12 papillary carcinomas). Positivity of immunostaining was semi-quantitatively scored by two pathologists. Angiogenesis was evaluated by immunostaining with anti-CD34 antibodies on serial sections. Cytoplasmic VEGF expression was detected in tumor cells in 35% (26/74) of RCCs, including 18 out of the 62 (29%) conventional RCCs and 8 out of the 12 (67%) papillary carcinomas (P=0.02). In the group of conventional RCCs, VEGF expression was positively correlated with both nuclear grade (P=0.05) and size of the tumor (P=0.05). Furthermore, a significant correlation was observed between VEGF expression and microvascular count (P=0.04). Finally, cumulative survival rate was significantly lower in the group of patients with conventional RCCs expressing VEGF (log rank test, P=0.01). In the Cox model, VEGF expression was a significant independent predictor of outcome, as well as stage and nuclear grade. This study suggests that VEGF is involved in angiogenesis in conventional RCCs and appears to be a potential prognostic factor in these tumors.
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