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Biomedical subjects

P Morel

Publications and source records attributed to P Morel.

At least 91 records · Page 5Linked to original sources
PubMed2001

Renal transplantation with donors aged over 50: a long-term, single centre experience.

BACKGROUND: Renal transplantation is now considered the best treatment for end-stage renal failure patients. In view of the worldwide growing waiting list, extending donor age is one of the strategies implemented to make more kidneys available for transplantation. METHODS: From October 1983 to February 2000, 324 renal transplantations were performed at Geneva University Hospital, 68 of which were done with kidneys from donors aged over 50 (mean donor age 55.3 + 4.8 years) The following data were analysed at 1, 5 and 10 years and compared between recipients with donors aged over 50 (> 50 years) and under 50 (< 50 years): actuarial patient and graft survival, serum creatinine, causes of graft loss. RESULTS: Patient survival at 10 years was 83% with donors < 50 years and 61% with donors > 50 years (non-significant). Graft survival at 10 years was 61% with donors < 50 years and 48% with donors > 50 years (non-significant). Graft survival at 10 years or death with functioning graft was 69% with donors < 50 years and 68% with donors > 50 years (non-significant). Overall, donor age was not a predictive factor for graft survival, as shown by multiple logistic regression. CONCLUSIONS: Kidneys obtained from donors > 50 years are suitable for renal transplantation and yield acceptable graft survival.

Adolescent↗
PubMed2001

Human islet transplantation network for the treatment of Type I diabetes: first data from the Swiss-French GRAGIL consortium (1999-2000). Groupe de Recherche Rhin Rhĵne Alpes Genève pour la transplantation d'Ilots de Langerhans.

AIMS/HYPOTHESIS: Improvements in islet transplantation require clinical series large enough to implement controlled new strategies. The goal of this study was to demonstrate the feasibility of a multicentre network for islet transplantation in Type I (insulin-dependent) diabetic patients. METHODS: The five centres (Besançon, Geneva, Grenoble, Lyon, Strasbourg) of the GRAGIL network allow pancreas procurement, recipient recruitment, transplantation procedure and follow-up. Islet isolation is, however, performed in one single laboratory (Geneva). Pancreata were procured in each of the five centres and transported to Geneva with an ischaemia time of less than 8 hours. Islets were isolated using a standard automated method. If the islet number was too low for a graft (< 6,000 Islet-equivalent/kg), islets were cultured up to 12 days until another isolation was possible. Islets were transplanted by percutaneous transhepatic intraportal injection. Immunosuppression consisted of cyclosporine, mycophenolate mofetil, steroids and an anti-interleukin 2 receptor antibody. RESULTS: From March 1999 to June 2000, 56 pancreata procurements were performed with an average yield of 234500 islet-equivalent, with 32 preparations over 200000 islet-equivalent. Ten C-peptide negative Type I diabetic patients (5 men and 5 women, median age 44 years, median diabetes duration 29 years) with an established kidney graft (> 6 months) received 9,030 +/- 1,090 islet-equivalent/kg with a median purity of 63 %. The number of pancreata required for each graft was 1 (n = 5) or 2 (n = 5). At the completion of a 12 month follow-up, we observed 0% primary nonfunction, 50% graft survival and 20% insulin-independence. CONCLUSIONS/INTERPRETATION: This study demonstrates the interest and the feasibility of a multicentre collaboration in human islet transplantation.

Adult↗
PubMed2001

Insulin independence and normalization of oral glucose tolerance test after islet cell allotransplantation.

To achieve permanent normoglycemia in patients with type I diabetes, it is necessary to renew the insulin-producing beta-cells by transplantation of either a vascularized pancreatic graft or isolated islets of Langerhans. Presently, about 10% of patients with type I diabetes undergoing islet allotransplantation achieve insulin independence; however, glucose intolerance remains in the majority of cases. We report a case of long-term insulin independence after islet allotransplantation in a type I diabetic patient. Three years after islet transplantation, the patient remains insulin-independent with a normal oral glucose tolerance test (OGTT). The patient therefore no longer meets the World Health Organization criteria for the diagnosis of diabetes mellitus and demonstrates that islet transplantation can cure diabetes in type I diabetic patients.

Adult↗
PubMed2001

Evaluation of standard tyrosinase RT-PCR in melanoma patients by the use of the LightCycler system.

BACKGROUND: Haematogenous spread influences outcome in melanoma patients. The clinical relevance of detecting circulating melanoma cells in peripheral blood by tyrosinase mRNA RT-PCR is, however, questioned as rates of positivity considerably vary between studies. Standard tyrosinase-nested RT-PCR was here compared with a real-time PCR technique. METHODS: Forty-three blood samples from 20 stage III--IV melanoma patients were analyzed. Mononuclear cells were isolated using a Ficoll Hypaque gradient technique. Total RNA extracted by the acid guanidinum thiocyanate-phenol-chloroform method was reverse transcribed using random hexamers or specific primers. Standard tyrosinase-nested PCR was performed on Touchdown machine (Hybaid) and real-time PCR on a LightCycler instrument (Roche). RESULTS: Only two samples from stage IV patients (one from random hexamers, one from antisense primers) were found tyrosinase positive with a 100% agreement between the two PCR techniques. A 10-fold dilution of the first-round products improved the PCR kinetic and the final amount of amplified product of positive samples, but not the rate of positivity. CONCLUSIONS: Efficiency of the PCR reaction can be monitored in an online fashion by the LightCycler instrument allowing technical improvements. However, tyrosinase mRNA RT-PCR cannot be yet considered as a useful technique in the monitoring of melanoma patients.

Adult↗
PubMed2001

Tandem autotransplant as first-line consolidative treatment in poor-risk aggressive lymphoma: a pilot study of 36 patients.

PURPOSE: In the previous LNH87-2 study, consolidative high-dose therapy followed by stem cell transplantation (HDT) improved disease-free survival, as well as survival for patients (pts) presenting with two or three factors of the age-adjusted international prognostic index (Aa-IPI) in first complete remission (CR). In order to improve further the outcome of such patients, we conducted a pilot study of consolidative tandem autotranplant. PATIENTS AND METHODS: Thirty-six patients (pts) under 60 years of age with two or three factors of the Aa-IPI were enrolled. Their main characteristics were: diffuse large B-cell lymphoma (83%), Aa-IPI three factors (50%), and marrow involved (36)%. The procedure consisted of 1) induction with four cycles of ACVBP (doxorubicin, cyclophosphamide, vindesine, bleomycin, prednisone) 2) in responding pts, peripheral blood stem cell (PBSC) collection after the fourth cycle of ACVBP (11 pts) or after an additional mobilization regimen (Cyclophosphamide-VP16) (17 pts) 3) a first HDT (mitoxantrone, cyclophosphamide, VP16 and carmustine) followed by PBSC infusion 4) a second HDT (busulfan, carboplatin and melphalan) followed by PBSC infusion. Among the 29 patients responding to induction, 28 received the first HDTand 24 the second. RESULTS: The rates of three-year-event free survival and survival are 47% (95% confidence interval (95% CI: 31%-63%) and 50% (95% CI: 37%-69%), respectively. Eighteen patients remained free of evolutive disease and 18 patients have died, 15 from disease progression and three from treatment-related toxicity after tandem transplant (two veno-occlusive disease and one cerebral toxoplasmosis). CONCLUSION: We conclude that tandem transplant did not improve the results of the LNH87-2 study in which patients received a single consolidative HDT.

Adolescent↗
PubMed2001

[Multidisciplinary management of hereditary colorectal cancer].

AIM: The aim of this study was to assess the feasibility and success of multidisciplinary approach for the management of hereditary colorectal cancer. MATERIAL AND METHODS: From November 1998 to November 2000, 32 individuals with putative familial/hereditary predisposition to colorectal cancer were investigated for adenomatous polyposis (attenuated or classical familial adenomatous polyposis coli, FAP) or for hereditary nonpolyposis colorectal cancer (HNPCC). Amsterdam criteria (I and II) and Bethesda guidelines were used to select putative HNPCC kindreds. Clinical data including endoscopy, pathological and operative reports as well as family history were collected. Pre- and post-test genetic counseling was offered to at-risk individuals. Genetic testing included microsatellite instability (MSI) and search for germline mutations in the APC, hMSH2 and hMLH1 genes. Immunohistochemistry (IHC) of hMSH2 and hMLH1 protein expression in tumour samples was also performed. RESULTS: 11 APC mutations were characterized, whereas four mutations in HNPCC genes were found in hMSH2 (2) and in hMLH1 (2). MSI and IHC correlated completely for cases with identified pathogenic mutation (100%). CONCLUSION: A thorough evaluation and management of hereditary colorectal requires a multidisciplinary approach. Thus, more mutation carriers can be identified and benefit from appropriate genetic counselling, while non-carrier individuals are relieved from unnecessary surveillance.

Adenomatous Polyposis Coli↗
PubMed2001

Assessing the Cox model assumption as a statistical tool for classifying lymphomas.

INTRODUCTION: The Cox model is widely used in medical research for comparing survival. Lymphomas might exhibit important differences in long-term cure rate despite a similar survival. METHODS: Using log-rank test, we compared event-free survival (EFS), and the survival of 64 patients with mantle cell lymphoma (MCL), 525 patients with follicular lymphoma, and 1136 patients with diffuse centroblastic lymphoma (CB). RESULTS: Although EFS and survival of MCL were significantly shorter than those of follicular lymphoma, checking the validity of the proportional hazards assumption shows that the distribution of rates of events and deaths over time did not differ in MCL and follicular lymphoma. In contrast, the ratios of hazards (events and deaths rates) did not remain constant over time in MCL and CB, because of a decrease in late events and deaths rates in the latter histological type. CONCLUSION: Checking the validity of the Cox model hypothesis might be a useful tool for assessing long-term cure rate in seldom lymphoma subtypes. Despite a short overall survival, MCL should not be considered to be an aggressive lymphoma, in which available chemotherapy may cure a subset of patients.

Adult↗
PubMed2001

Tumor necrosis factor alpha release is a major biological event associated with rituximab treatment.

INTRODUCTION: In patients with low-grade non-Hodgkin's lymphoma, rituximab (MabThera) produces infusion-related toxicity, including fever, rigors, and chills in greater than 50% of those treated. The majority of these reactions are grade 1 or 2. MATERIALS AND METHODS: In the GELA study LNH98-5, a total of 400 elderly patients with previously untreated diffuse large B-cell lymphoma were randomized to treatment with CHOP or with rituximab plus CHOP (R-CHOP). In a detailed investigation of biological events which may be associated with adverse reactions specific to rituximab infusion, a subgroup of 55 patients (26 in the CHOP group and 29 in the R-CHOP group) were selected for measurement of several biological parameters at baseline and at 1, 4 and 8 h (H1, H4 and H8, respectively) after commencing therapy. For 27 patients, measurements included cytokine and complement levels. RESULTS: Baseline demographic and disease characteristics were similar for patients in both treatment groups. Compared with the CHOP treatment group, patients in the R-CHOP group had significantly higher post-treatment changes in neutrophil, lymphocyte, and monocyte counts, LDH levels, C3a levels, and TNF-alpha levels. In the R-CHOP group, neutrophil levels increased at H4 (P<0.05), lymphocyte levels decreased at H1 (P<0.05), H4 (P<0.001) and H8 (P<0.05), monocytes levels decreased at H1 (P<0.01), LDH levels increased at H4 (P<0.05) and H8 (P<0.01), and C3a decreased at H1 (P<0.01). The most statistically significant changes were observed for TNF-alpha levels: Mean values of TNF-alpha increased more than 250% at H1 and H4 and were still increased by 170% at H8 (P<0.001 at all timepoints). Since only six of the 55 evaluated patients had severe adverse events, it was not possible to correlate severe toxicity with these biological variations. CONCLUSION: This analysis demonstrates that rituximab infusion was rapidly followed by activation of complement, B-lymphocyte cytolysis, and TNF-alpha release.

Aged↗
PubMed2001

Virologic and immunologic parameters that predict clinical response of AIDS-associated Kaposi's sarcoma to highly active antiretroviral therapy.

The purpose of the work was to assess the predictive value of biologic factors on the efficacy of highly active antiretroviral therapy alone or combined with chemotherapy on AIDS-associated Kaposi's sarcoma. Twenty-six AIDS-Kaposi's sarcoma patients who started therapy with protease inhibitors were investigated. No baseline chemotherapy was associated with less severe initial clinical status. Median follow-up was 652 d. The main outcome measures were as follows: best Kaposi's sarcoma clinical response; Kaposi's-sarcoma-associated herpesviral load in peripheral blood mononuclear cells using real-time quantitative polymerase chain reaction (non-detectable if less than 100 copies per microg); human immunodeficiency viral charge in plasma (non-detectable if less than 200 copies per ml); and CD4 lymphocyte count. Time to undetectable Kaposi's-sarcoma-associated herpesviral load, time to undetectable human immunodeficiency viral charge, and time to CD4 >or= 150 per microl were also recorded over time, from 2 mo measurements. Patients were staged according to the AIDS Clinical Trials Group-based tumor, immune, systemic staging system criteria. At baseline, Kaposi's sarcoma was progressive for 25 (96%) of the 26 enrolled patients. Complete or partial response to highly active antiretroviral therapy alone or combined with chemotherapy was achieved in 22 patients (85%). Median time to clinical response was estimated at 251 d. Clinical response was faster in patients without chemotherapy at baseline (p = 0.003) as well as in patients not previously treated with reverse transcriptase inhibitors (p = 0.0012). Using univariable analyses, predictive factors of clinical response were undetectable Kaposi's-sarcoma-associated herpesviremia (p = 0.013), undetectable human immunodeficiency viremia (p = 0.03), and relative variation of CD4 lymphocytes (p = 0.004). Using multivariable analysis, undetectable Kaposi's-sarcoma-associated herpesviremia (p = 0.009) and relative variation of CD4 (p = 0.005) were independently selected as having a predictive value for clinical response. Occurrence of nondetection of either Kaposi's-sarcoma-associated herpesvirus or human immunodeficiency virus was not associated with baseline CD4 value. Kaposi's-sarcoma-associated herpesvirus quantitative viral charge is an independent predictive factor of the efficacy of highly active antiretroviral therapy on AIDS-Kaposi's sarcoma. Our results support immune reconstitution as a mechanism of response of Kaposi's sarcoma to highly active antiretroviral therapy.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Cd40 ligand-deficient mice are protected against cerulein-induced acute pancreatitis and pancreatitis-associated lung injury.

BACKGROUND AND AIMS: The interactions between inflammatory cells and their mediators play important roles in many inflammatory processes, but their importance during acute experimental pancreatitis and pancreatitis-associated lung injury is unclear. To address the role of the interaction between CD40 and its ligand CD40L, molecules that mediate major immunoregulatory functions, pancreatitis was induced by administering supramaximal doses of cerulein in mice that do not express CD40L. METHODS: The severity of pancreatitis was measured by serum amylase activity, pancreatic edema, acinar cell necrosis, and pancreas myeloperoxidase activity (an indicator of neutrophil infiltration). Lung injury was quantitated by evaluating lung microvascular permeability and lung myeloperoxidase activity. RESULTS: In pancreatic tissue from control mice and cerulein-treated mice, the expression of both CD40 and CD40L was detected. Immunohistochemical analysis performed in isolated acini from wild-type pancreata showed that both CD40 and CD40L were expressed on the acinar cell surface. Interestingly, pancreatitis and pancreatitis-associated lung injury were markedly decreased in mice deficient in CD40L compared with wild-types. CONCLUSIONS: These observations indicate that CD40L plays an important proinflammatory role in pancreatitis and pancreatitis-associated lung injury.

Acute Disease↗
PubMed2001

Obtaining a superficial femoral artery graft in adolescents and children with the deep femoral artery transposition.

A new technique to obtain a segment of the superficial femoral artery as an arterial conduit in young patients while an unobstructed peripheral blood flow is maintained by superficial femoral artery-deep femoral artery transposition is illustrated with two clinical examples. The explanted arterial autograft requires no replacement by another graft and provides a conduit of up to 10 cm in length. Excellent results were achieved in both patients at 1 year. This technique is recommended instead of saphenous vein conduits in very young patients because of the risk for late vein degeneration.

Adolescent↗
PubMed2001

Meckel's diverticulum in adults: retrospective analysis of 119 cases and historical review.

OBJECTIVE: To publish our experience in the management of Meckel's diverticula in adults, and compare our results with those published elsewhere. DESIGN: Retrospective investigation of casenotes. SETTING: Multicentre study, Switzerland. SUBJECTS: 119 patients aged over 16 years who had Meckel's diverticula resected between 1980 and 1997. MAIN OUTCOME MEASURES: Assessment of the usefulness of various investigations and the criteria for removing asymptomatic diverticula. RESULTS: 67 diverticula (56%) were resected during laparotomy for another cause, and 52 (44%) for symptoms caused by the diverticula. In both groups the condition was more common in men, and most likely to present during the fourth decade. The most common investigation in the 52 symptomatic cases was a plain film of the abdomen (n = 47, 90%), and in none was a Meckel's diverticulum suggested as the cause of the symptoms. The success rates of other investigations were: small bowel enema 4/9, 99mTc scan 3/4, angiography 1/3, and computed tomography 1/14. No ultrasound scans were done. Our results compared favourably with those reported elsewhere, with no deaths in either group, 2 complications that required reoperation in the incidental group, and 1 in the symptomatic group. CONCLUSIONS: The criteria to be taken into account when deciding to resect an asymptomatic diverticulum are: male sex, age <40, ASA score, the operation being done, the size and position of the diverticulum, whether it is palpable, and whether there are other reasons for the patient's complaints.

Adolescent↗
PubMed2001

Renal transplantation in the elderly: a long-term, single-centre experience.

BACKGROUND: End-stage renal failure increases with advancing age and renal transplantation should be considered in end-stage renal failure patients older than 60 years. However, there is a paucity of data on long-term patient and graft survival in this population. METHODS: From October 1983 to March 1999, 310 renal transplantations were performed at Geneva University Hospital in 283 patients, of which 49 were done in 48 patients older than 60 years (mean age 65.6+/-4.1 years). The following data were analysed at 1, 5, and 10 years, and compared between the patients >60 years and <60 years old: actuarial patient and graft survival, serum creatinine, causes of graft loss, and patient death. RESULTS: Patient survival at 10 years was 81% for patients <60 years and 44% for patients >60 years. Graft survival at 10 years was 59% for patients <60 years and 32% for patients >60 years. Graft survival at 10 years censored for death with functioning graft was 65% for patients <60 years and 81% for patients >60 years. Main causes of mortality in the older patients were related to cardiovascular events (47%), neoplasia (41%), and sepsis (18%). Overall, recipient and donor age were not predictive factors for graft survival, as shown by multiple logistic regression. CONCLUSIONS: Renal transplantation should be considered in patients older than 60 years, since graft survival is excellent in this population. Although these patients have a shorter life expectancy, they benefit from renal transplantation similarly to younger kidney transplant recipients.

Adolescent↗
PubMed2001

Effects of abdominal Co2 insufflation on renal and hepatic blood flows during acute hemorrhage in anesthetized pigs.

OBJECTIVE: To evaluate the consequences of laparoscopy during hemorrhage, we studied the respiratory, renal, and hepatic blood flow changes induced by abdominal Co2 insufflation during severe hemorrhage in anesthetized pigs. DESIGN: Prospective animal study. SETTING: University research laboratory. SUBJECTS: Anesthetized and ventilated pigs (n = 18). INTERVENTIONS: The right carotid artery was cannulated to measure mean arterial pressure. A pulmonary artery catheter was inserted to measure mean pulmonary arterial pressure and cardiac output. After a midline abdominal incision, three flow probes were positioned around the portal vein, the hepatic artery, and the renal artery to measure portal vein blood flow, hepatic artery blood flow, and renal blood flow. To induce hemorrhage, blood was withdrawn until mean arterial pressure reached 50 mm Hg. Laparoscopy was mimicked by insufflating Co2 until intra-abdominal pressure reached approximately 15 mm Hg. Measurements were collected during hemorrhage, Co2 abdominal insufflation, and the combination of both interventions. MEASUREMENTS AND MAIN RESULTS: Severe pulmonary hypertension and hypercapnic acidosis occurred during abdominal Co2 insufflation. However, the abdominal Co2 insufflation did not aggravate the cardiac output and total hepatic blood flow changes induced by acute hemorrhage, whereas the combination of hemorrhage and abdominal Co2 insufflation markedly altered renal blood flow. CONCLUSIONS: These results suggest that renal function must be monitored carefully when performing laparoscopy in trauma patients. In contrast, hepatic perfusion seems well preserved.

Analysis of Variance↗
PubMed2001

Clinical and histopathologic features and immunologic variables in patients with severe chilblains. A study of the relationship to lupus erythematosus.

We investigated 33 patients affected with chilblain lesions following a persisting course of more than 1 month. We focused on the incidence of an underlying connective tissue disease, mostly lupus erythematosus (LE), and we analyzed features of idiopathic chilblains compared with those of chilblain lesions associated with connective tissue disease. We also carried out a prospective follow-up of patients. Eleven patients included in the study were free of any clinical and/or laboratory abnormality suggestive of connective tissue disease, while 22 of 33 patients showed 1 or several abnormalities raising suspicion for connective tissue disease, and among them 8 had a diagnosis of systemic lupus erythematosus (SLE) established at initial evaluation based on the American College of Rheumatology revised criteria. The comparative analysis of patients with idiopathic chilblains and patients with chilblains associated with LE showed that female sex and persistence of lesions beyond cold seasons were significantly associated with chilblain LE. Histopathologic studies of chilblain lesions did not reveal features typical of LE in any case, but revealed a higher incidence of a deep perisudoral infiltrate in idiopathic chilblains. In patients showing signs of connective tissue disease, positive cutaneous immunofluorescence was correlated with the presence of circulating antinuclear antibodies. Two patients had an ascertained diagnosis of SLE with severe manifestations during prospective follow-up, requiring treatment with oral steroids in both cases. Chilblains following a chronic course may reveal connective tissue disease, and patients affected with chilblains associated with autoimmune abnormalities may develop severe SLE. Accordingly, long-term follow-up of these patients is warranted.

Adolescent↗
PubMed2001

Beta cell replacement for the treatment of diabetes.

The replacement of insulin-producing beta cells by islet transplantation can efficiently reverse diabetes. The recent improvements in clinical results were made possible by transplanting higher islet masses and through the introduction of new immunosuppressive protocols that avoid diabetogenicity. The need for alternatives to continuous immunosuppression, and an unlimited source of glucose-sensitive, insulin-secreting tissue, is emerging. In this review we discuss the various key steps in islet transplantation and offer perspectives for future developments in the replacement of insulin-producing beta cells for the treatment of type I diabetes.

Animals↗