Biomedical subjects

A Lemoine

Publications and source records attributed to A Lemoine.

At least 19 recordsLinked to original sources

PubMed2006

Prognosis of stage II colon cancer by non-neoplastic mucosa gene expression profiling.

We have assessed the possibility to build a prognosis predictor (PP), based on non-neoplastic mucosa microarray gene expression measures, for stage II colon cancer patients. Non-neoplastic colonic mucosa mRNA samples from 24 patients (10 with a metachronous metastasis, 14 with no recurrence) were profiled using the Affymetrix HGU133A GeneChip. Patients were repeatedly and randomly divided into 1000 training sets (TSs) of size 16 and validation sets (VS) of size 8. For each TS/VS split, a 70-gene PP, identified on the TS by selecting the 70 most differentially expressed genes and applying diagonal linear discriminant analysis, was used to predict the prognoses of VS patients. Mean prognosis prediction performances of the 70-gene PP were 81.8% for accuracy, 73.0% for sensitivity and 87.1% for specificity. Informative genes suggested branching signal-transduction pathways with possible extensive networks between individual pathways. They also included genes coding for proteins involved in immune surveillance. In conclusion, our study suggests that one can build an accurate PP for stage II colon cancer patients, based on non-neoplastic mucosa microarray gene expression measures.

Adenocarcinoma↗

PubMed2006

Solid-phase synthesis and pharmacological evaluation of a library of peptidomimetics as potential farnesyltransferase inhibitors: an approach to new lead compounds.

Oncogenic Ras proteins whose activation is farnesylation by farnesyltransferase have been seen as important targets for novel anticancer drugs. Inhibitors of this enzyme have already been developed as potential anti-cancer drugs, particularly by rational design based on the structure of the CA(1)A(2)X carboxyl terminus of Ras. Synthesis of a peptidomimetics library via solid-phase synthesis using the Multipin method is described here. The most active hits on cellular assays were resynthesized and enzymatic activity was measured. Compounds A1, A5 and A7 present significant activity on the isolated enzyme (IC(50)=117, 57.3 and 28.5 nM) and their molecular docking in the active site of the enzyme provides details on key interactions with the protein.

Enzyme Inhibitors↗

PubMed2006

Co expression of SCF and KIT in gastrointestinal stromal tumours (GISTs) suggests an autocrine/paracrine mechanism.

KIT is a tyrosine kinase receptor expressed by several tumours, which has for specific ligand the stem cell factor (SCF). KIT is the main oncogene in gastrointestinal stromal tumours (GISTs), and gain-of-function KIT mutations are present in 70% of these tumours. The aim of the study was to measure and investigate the mechanisms of KIT activation in 80 KIT-positive GIST patients. KIT activation was quantified by detecting phosphotyrosine residues in Western blotting. SCF production was determined by reverse transcriptase-PCR, ELISA and/or immunohistochemistry. Primary cultures established from three GISTs were also analysed. The results show that KIT activation was detected in all cases, even in absence of KIT mutations. The fraction of activated KIT was not correlated with the mutational status of GISTs. Membrane and soluble isoforms of SCF mRNA were present in all GISTs analysed. Additionally, SCF was also detected in up to 93% of GISTs, and seen to be present within GIST cells. Likewise, the two SCF mRNA isoforms were found to be expressed in GIST-derived primary cultures. Thus, KIT activation in GISTs may in part result from the presence of SCF within the tumours.

Autocrine Communication↗

PubMed2006

Fate and characterization of circulating tumor cells in a NOD/SCID mouse model of human hepatocellular carcinoma.

There is much debate about the way in which epithelial tumors metastasize. It has been proposed that the bone marrow (BM) acts as a tumor cell reservoir. We injected human hepatocellular carcinoma (HCC) cells (Mahlavu cell line) into the livers, circulation or BM of NOD/SCID mice and circulating tumor cells were quantified. When injected under the Glisson capsule, a primary tumor developed and continuously yielded circulating tumor cells. Liver tumor removal led to a very low level of Mahlavu cells both in blood and BM 30 days later. When Mahlavu cells (cultured or from BM of primary mice femurs) were intravenously injected into mice, the number of cells in the bloodstream (BS) steadily decreased, whereas the BM was not significantly colonized. When Mahlavu cells were directly injected into one femur, the controlateral femur was not colonized. Microscopic analysis and a sensitive PCR assay (<1 Mahlavu cell/nuclear cells) both failed to detect human tumor cells in other organs regardless of injection route. In conclusion, our model strongly supports the hypothesis that HCCs continuously release cells into the BS. However, in sharp contrast with the current hypothesis, the BM is not specifically colonized by tumor cells but could store them at a very low level.

Animals↗

PubMed2004

A functional analysis of ACP-20, an adult-specific cuticular protein gene from the beetle Tenebrio: role of an intronic sequence in transcriptional activation during the late metamorphic period.

A gene encoding the adult cuticular protein ACP-20 was isolated in Tenebrio. It consists of three exons interspersed by two introns, intron 1 interrupting the signal peptide. To understand the regulatory mechanisms of ACP-20 expression, ACP-20 promoter-luciferase reporter gene constructs were transfected into cultured pharate adult wing epidermis. Transfection assays needed the presence of 20-hydroxyecdysone, confirming that ACP-20 is up-regulated by ecdysteroids. Analysis of 5' deletion constructs revealed that three regions are necessary for high levels of transcription. Interaction experiments between intronic fragments and epidermal nuclear proteins confirmed the importance of intron 1 in ACP-20 transcriptional control, which results from the combined activity of regulatory cis-acting elements of the promoter and those of intron 1.

Amino Acid Sequence↗

PubMed2002

Rapid automated simultaneous screening of (G1691A) Factor V, (G20210A) prothrombin, and (C677T) methylenetetrahydrofolate reductase variants by multiplex PCR using fluorescence scanning technology.

The Factor V Leiden mutation (G1691A), and mutations in the prothrombin (G20210A) and 5,10-methylenetetrahydrofolate reductase (C677T) genes are common hereditary risk factors associated with venous thrombosis. The aim of this study was to develop an automated, PCR-based genotyping assay for rapid simultaneous screening of these three mutations. We adapted multiplex PCR, using primer modifications to introduce cleavage sites for restriction endonucleases into the fragments bearing each of the mutations. The three mutations were analyzed in a single tube by fluorescence scanning. An internal digestion control was introduced to prevent false-negative results due to incomplete digestion or a total lack of digestion. DNA fragment analysis was carried out using an automated capillary electrophoresis instrument (ABI310). This reliable, efficient, easy-to-use assay can be applied to specimens from large clinical trials and epidemiological surveys.

Factor V↗

PubMed2001

Detection of gammopathy by serum protein electrophoresis for predicting and managing therapy of lymphoproliferative disorder in 911 recipients of liver transplants.

Monitoring of posttransplantation lymphoproliferative disorder (LPD) is usually based on imaging, which lacks sensitivity. A prospective study in 911 consecutive recipients of liver transplants was conducted to assess the value of gammopathy monitoring by serum protein electrophoresis (SPE) and to compare it with conventional follow-up methods. Patients systematically underwent SPE testing just before transplantation, at least twice during the first year after transplantation, and once a year thereafter. Patients with LPD underwent SPE testing every month. Immunofixation was done if abnormalities were detected by SPE. Gammopathy was observed in 114 patients, 18 of whom had onset of LPD. In 3 other patients, LPD developed, but no gammopathy was detected before onset of LPD or while LPD was present. Multivariate analyses showed gammopathy (relative risk [RR], 65.3), more than one transplantation (RR, 7.5), and viral cirrhosis (RR, 2.8) to be independent prognostic factors associated with occurrence of LPD. LPD was treated by reducing immunosuppression, with or without chemotherapy, administration of anti-CD20 monoclonal antibody, or surgery. The mortality rate was 24% (5 of 21 patients). Remission, which occurred in 13 patients, was associated with disappearance of gammopathy in 10 patients. In 5 patients, normalization of SPE results preceded the diagnosis of remission based on imaging, by a mean of 4 months. For diagnosis of LPD remission, the positive and negative predictive values of disappearance of gammopathy were 91% and 100%, respectively; and gammopathy monitoring was more sensitive than imaging (100% and 38%, respectively). Gammopathy monitoring is an inexpensive, noninvasive, sensitive way to detect LPD and assess the efficacy of treatment. It could be used routinely in follow-up of recipients of transplants.

Adult↗

PubMed2001

Functional metabolic characteristics of intact pig livers during prolonged extracorporeal perfusion: potential for a unique biological liver-assist device.

BACKGROUND: The clinical development of liver-support devices based on perfusion of either pig hepatocytes cartridges or whole pig livers has been hampered by the ability to use sufficient liver cell mass to provide adequate metabolic support, limited perfusion times, and the potential for patient exposure to pig zoonotic diseases. METHODS: We designed an original system in which an isolated intact pig liver was perfused extracorporeally under physiological conditions in a closed loop circuit with allogeneic pig blood and constant monitoring of major physiological and functional parameters. The perfusion circuit further included an interface membrane to provide for separation of patient and liver perfusion circulation. RESULTS: Prolonged (6-21 hr) liver perfusion did not produce significant liver damage as reflected by modest rises in the levels of the serum transaminases, stability of main biochemical parameters (including potassium), and the maintenance of normal cellular morphology. Optimal liver function was documented as measured by lactate consumption, control of glycemia, and the results of clotting studies and functional assays. The perfused liver cleared 82% and 79% of peak bilirubin and ammonia concentrations with clearing kinetics identical throughout perfusion. Indocyanine green clearance was identical to that observed in the living donor before explant surgery. CONCLUSIONS: In conclusion, the extracorporeal pig liver perfusion apparatus described here allows optimal pig liver function for prolonged periods of time. The microporous membrane to provide separation of donor organ and recipient and the high level of functional activity suggest that this form of liver metabolic support may have important clinical applications.

Ammonia↗

PubMed2001

Results of recto-vaginal fistula repair: retrospective analysis of 48 cases.

OBJECTIVE: To evaluate the long-term outcome of the Musset technique of recto-vaginal fistula (RVF) repair. STUDY DESIGN: During the years 1992-1998, 48 women underwent recto-vaginal fistula repair. A retrospective study in a university tertiary referral center was conducted. RESULTS: The main etiologies were obstetrical trauma (25), local infection (11), inflammatory disease (7), and post surgery (3). Thirty women (63%) had a previous fistula repair failure. The mean+/-S.D. fistula diameter was 1.4+/-1.0, and in 40% of the patients the fistula diameter was >2.5cm. In 19 cases (39.6%) there was a complete opening of the perineum and anal sphincter. Gas and stool incontinence before the operation were noted in 85 and 75% of the patients, respectively. Successful anatomic results were achieved in all patients. Five patients were re-operated due to gas and stool incontinence, and all but one had satisfactory anatomic and functional satisfactory results. The success rates in women with Crohn's disease and with a previous RVF repair failure were 100 and 98%, respectively. No major intra or postoperative complications were noted. CONCLUSION: The Musset procedure provide excellent anatomic and functional results and women with Crohn's disease or previous RVF repair have comparable long-term results.

Adult↗

PubMed2001

Histological, genomic and clinical heterogeneity of clear cell hepatocellular carcinoma.

AIMS: The aim of the study was to determine whether clear cell type hepatocellular carcinoma should still be regarded as a separate uniform diagnostic entity. METHODS AND RESULTS: We retrospectively studied 118 cirrhotic patients with hepatocellular carcinoma treated by orthotopic liver transplantation, and 31 noncirrhotic patients with hepatocellular carcinoma treated by either liver surgical resection or transplantation. The pathology of all liver resections was reviewed. Microsatellite instability was performed on paraffin-embedded samples at loci located on chromosomes 2p, 3p, 5q, 8q, 9p, 13q, 16q and 17p. Among the 118 cirrhotic patients, 10 (8.5%) had a clear cell hepatocellular carcinoma; these had clinical characteristics and prognosis similar to the other cirrhotic patients. No genetic alterations were detected in these tumours. Among the 31 noncirrhotic patients, one (3.2%) had a clear cell hepatocellular tumour. This 170-mm tumour had a lipid density on computed tomography, and its histology resembled chromophobe cell renal carcinoma. Furthermore, this tumour had unusual genomic alterations, with microsatellite instability in 6/8 chromosome loci. CONCLUSIONS: Clear cell hepatocellular carcinoma is a heterogeneous entity in which a chromophobe cell subtype should be identified.

Adolescent↗

PubMed2000

Real-time quantitation of bcr-abl transcripts in haematological malignancies.

We have applied an automated real-time quantitative PCR assay using a double-labeled fluorogenic probe to detect t(9;22)-positive cells in haematological malignancies. The results are expressed as the ratio of chimeric bcr-abl transcripts on abl transcripts. Highly reproducible results were obtained for t(9;22)-positive K562 RNA. Ten copies of bcr-abl DNA from a recombinant KW-3 plasmid and one positive cell in 10(4) can be detected. Thirty-two patients with chronic myeloid leukaemia (CML), 25 with acute leukaemia, 12 with myelodysplastic syndromes and 7 with other myeloproliferative syndromes were tested. Follow-up data were obtained in bcr-abl positive cases. Results were compared with those of conventional nested RT-PCR and cytogenetics. Real-time quantitative RT-PCR values correlated well with both these methods. However, in some cases the only means of detecting early relapse or blastic transformation was to examine the kinetics of real-time quantitative RT-PCR. Thus, real-time quantitative RT-PCR appears suitable for the diagnosis and follow-up of patients with the t(9;22) translocation.

Acute Disease↗

PubMed2000

Transjugular intrahepatic portosystemic shunt (TIPS) for severe veno-occlusive disease of the liver following bone marrow transplantation.

Severe veno-occlusive disease (VOD) of the liver is a leading cause of mortality after bone marrow transplantation (BMT). Vascular and parenchymal injuries account for acute portal hypertension and liver failure is frequently present. We describe the results of transjugular intrahepatic portosystemic shunt (TIPS) for the management of VOD after BMT. TIPS was performed in 10 patients with histologically proven severe VOD. Portal hypertension was controlled by TIPS in all patients (mean hepatic venous pressure gradient before, 20 +/- 11 vs 6 +/- 5 mm Hg after TIPS, P < 0.01) without technical complications. Five patients with rapidly worsening VOD died within 10 days of TIPS without any improvement. The five remaining patients with less advanced disease showed improvement in various clinical and biological parameters. Four patients subsequently died. The lone survivor continues to do well with resolution of VOD 6 months after TIPS. TIPS can be performed safely and controls portal hypertension in VOD after BMT. Arguments from the present series and from eight previously reported cases favour earlier application of TIPS to obtain improved overall survival. Bone Marrow Transplantation (2000) 25, 987-992.

Adolescent↗

PubMed2000

Resection of nonresectable liver metastases from colorectal cancer after percutaneous portal vein embolization.

OBJECTIVE: To assess the influence of preoperative portal vein embolization (PVE) on the long-term outcome of liver resection for colorectal metastases. SUMMARY BACKGROUND DATA: Preoperative PVE of the liver induces hypertrophy of the remnant liver and increases the safety of hepatectomy. METHODS: Thirty patients underwent preoperative PVE and 88 patients did not before resection of four or more liver segments. PVE was performed when the estimated rate of remnant functional liver parenchyma (ERRFLP) assessed by CT scan volumetry was less than 40%. RESULTS: PVE was feasible in all patients. There were no deaths. The complication rate was 3%. The post-PVE ERRFLP was significantly increased compared with the pre-PVE value. Liver resection was performed after PVE in 19 patients (63%), with surgical death and complication rates of 4% and 7% respectively. PVE increased the number of resections of more than four segments by 19% (17/88). Actuarial survival rates after hepatectomy with or without previous PVE were comparable: 81%, 67%, and 40% versus 88%, 61%, and 38% at 1, 3, and 5 years respectively. CONCLUSIONS: PVE allows more patients with previously unresectable liver tumors to benefit from resection. Long-term survival is comparable to that after resection without PVE.

Aged↗

PubMed2000

Percutaneous portal vein embolization increases the feasibility and safety of major liver resection for hepatocellular carcinoma in injured liver.

OBJECTIVE: To assess the influence of preoperative portal vein embolization (PVE) on the long-term outcome of liver resection for hepatocellular carcinoma (HCC) in injured liver. SUMMARY BACKGROUND DATA: On an healthy liver, PVE of the liver to be resected induces hypertrophy of the remnant liver and increases the safety of hepatectomy. On injured liver, this effect is still debated. METHODS: During the study period, 10 patients underwent preoperative PVE and 19 patients did not before resection of three or more liver segments for HCC in injured liver (cirrhosis or fibrosis). PVE was performed when the estimated rate of remnant functional liver parenchyma (ERRFLP) assessed by computed tomographic scan volumetry was less than 40%. RESULTS: In all patients, PVE was feasible. There were no deaths or complications. The ERRFLP after PVE was significantly increased compared with the pre-PVE value. Liver resection was performed after PVE in 9 of 10 patients, with surgical death and complication rates of 0% and 45%, respectively. PVE increased the number of resections of three or more segments by 47% (9/19). Overall actuarial survival rates with or without previous PVE (89%, 67%, and 44% vs. 80%, 53%, and 53% at 1, 3 and 5 years, respectively) and disease-free actuarial survival rates (86%, 64%, and 21% vs. 55%, 17%, and 17% at 1, 3, and 5 years respectively) after hepatectomy were comparable. CONCLUSION: With the use of PVE, more patients with previously unresectable HCC in injured liver can benefit from resection. Long-term survival rates are comparable to those after resection without PVE.

Carcinoma, Hepatocellular↗

PubMed2000

[Hormone replacement therapy after endometrial or ovarian cancer].

Use of hormonal replacement therapy after treatment of ovarian or endometrial cancer remains a matter of debate. Novel adjuvant therapies tend to increase the survival of these patients, who are exposed to risk factors of hormonal deficiency subsequent to primary therapy. Therefore, the aims of the present review of literature was to analyse epidemiologic and clinical parameters on behalf on hormonal replacement therapy in this population.

Endometrial Neoplasms↗

PubMed1999

Microsatellite instability in European hepatocellular carcinoma.

Genetic instability has been detected in many types of cancers but poorly investigated in hepatocellular carcinoma (HCC). We have studied the incidence of microsatellite instability (MI) at eight highly polymorphic microsatellite markers and the poly A tract BAT26 and tested for mutations at two sites of repetitive sequence (poly-A nucleotides 709-718 and GT repeat-nucleotides 1931-1936) in the Transforming Growth Factor beta (TGFbeta) type II receptor (RII) gene, in a group of 46 European HCCs and the surrounding nontumour tissue. This analysis showed that 63% of HCCs exhibit MI in at least one chromosome locus and 41% in two or more loci. No mutations of the TGFbetaRII gene were found in the MI positive tumours. No correlation was found with clinicopathological characteristics of the tumours such as cirrhosis, etiology, number of nodules, Edmondson's grade and vascular invasion. However, in patients who had a rearranged D16S402 microsatellite in their tumour, the recurrent disease and the number of nodules were significantly higher than in the others (P<0.005 and P<0.02, respectively). We propose to consider D16S402 rearrangement in HCC as a prognostic factor to identify patients presenting a higher risk of recurrence.

Adolescent↗

PubMed1999

Clinical significance of circulating anti-p53 antibodies in European patients with hepatocellular carcinoma.

p53 alterations are considered to be predictive of poor prognosis in hepatocellular carcinoma (HCC) and may induce a humoral response. Anti-p53 serum antibodies were assessed by enzyme-linked immunosorbent assay (ELISA) using purified recombinant human p53 on 130 European HCC patients before treatment and during the clinical course of the disease. p53 immunohistochemistry was performed on tumours from the 52 patients who underwent surgery, and DNA sequencing analysis was initiated when circulating anti-p53 antibodies were detected. Nine (7%) HCC patients had anti-p53 serum antibodies before treatment. During a mean period of 30 months of follow-up, all the negative patients remained negative, even when recurrence was observed. Of the nine positive patients, eight were still positive 12-30 months after surgery. The presence of anti-p53 serum antibodies was correlated neither with mutation of the p53 gene nor the serum alpha-fetoprotein levels and clinicopathological characteristics of the tumours. However, a greater incidence of vascular invasion and accumulation of p53 protein were observed in the tumours of these patients (P<0.03 and P<0.01 respectively) as well as a better survival rate without recurrence (P = 0.05). In conclusion, as was recently shown in pancreatic cancer, anti-p53 serum antibodies may constitute a marker of relative 'good prognosis' in a subgroup of patients exhibiting one or several markers traditionally thought to be of bad prognosis.

Adolescent↗

PubMed1999

[Hepatocellular carcinoma].

Hepatocellular carcinoma is a rapidly fatal tumor that usually becomes symptomatic only at a stage beyond the reach of currently available treatments. The only hope for a cure lies in early diagnosis. It follows that an effective screening strategy should be used in high-risk populations, including patients with cirrhosis due to any cause, patients with chronic hepatitis B or C, and asymptomatic carriers of the B virus genome (and probably the C virus genome). Screening currently relies on physical examination and on two investigations, ultrasound scanning and the alpha-fetoprotein (AFP) assay, whose sensitivity and specificity vary with tumor size. The optimal interval between evaluations seems to be four to six months, although large prospective studies confirming this are not yet available. Because the AFP assay lacks sensitivity and specificity in patients with small tumors, other serum markers are being evaluated. In parallel, hepatitis B immunization and alpha interferon therapy of chronic hepatitis C are expected to decrease the incidence of hepatocellular carcinoma.

Carcinoma, Hepatocellular↗