Islet transplantation in a recipient presenting the factor V Leiden mutation.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to Philippe Morel.
Explore the source record for details and available documents.
BACKGROUND: Costimulatory blockade has been shown to allow long-term survival of xenogeneic islets. The aim of the present study was to analyze the possibility of xenogeneic islet retransplantation using costimulatory blockade. METHODS: Streptozotocin-induced diabetic C57/BL6 mice were transplanted with 1000 human islet equivalents. After 14 days, mice were nephrectomized (graftectomy) and retransplanted with human leukocyte antigen (HLA)-mismatched human islets under contralateral kidney capsule. Four groups were performed: I: all transplants (Tx) without MR1; II: first Tx without MR1, second Tx with MR1; III: first Tx with MR1, second Tx without MR1; and IV: all Tx with MR1. Recipient serums were analyzed by cross-match for serum-mediated cytotoxicity against human lymphocytes and islets. RESULTS: In group I, the second graft rejection was accelerated (graft survival, 5 +/- 3 days) compared with the first graft without MR1 (13 +/- 7 days). In groups II and III, second graft survivals were 16 +/-1 3 and 62 +/- 15 days, respectively. In group IV, second graft function was maintained for >100 days. Pretransplant cross-matches were all negative. Post-second Tx cross-matches were positive in groups I and II and negative in group IV. In group III, post-second Tx cross-matches were negative only for cells with HLA molecules present in the first donor. CONCLUSIONS: MR1 was unable to induce tolerance after sensitization. MR1 given at the first Tx only allowed prolonged survival of the second Tx, but rejection still occurred with development of antibodies against molecules not present on first donor cells, indicating that costimulatory blockade does not induce linked-suppression against species-specific antigens of xenografts but can induce donor-specific unresponsiveness. MR1 given for all sequential transplantation allowed long-term regraft survival and prevented occurrence of antidonor antibodies.
Explore the source record for details and available documents.
BACKGROUND: Abdominal and retroperitoneal Castleman's disease could present either as a localized disease or as a systemic disease. Castleman's disease is a lymphoid hyperplasia related to human Herpes virus type 8, which could have an aggressive behavior, similar to that of malignant lymphoid neoplasm mainly with the systemic type, or a benign one in its localized form. METHODS: The authors report two cases of localized Castleman's disease in the retroperitoneal space and review the current and recent progress in the knowledge of this atypical disease. CASES PRESENTATION: The two patients were young healthy women presenting with a hyper vascular peri-renal mass suggestive of malignant tumor. Both have been resected in-toto. One of them had an extensive resection with nephrectomy, while the second had a kidney preserving surgery. Pathological examination revealed localized Castleman's disease and surgical margins were free of disease. Postoperative course was uneventful, and after more than 5-years of follow-up no recurrences have been observed. CONCLUSION: Localized Castleman's disease should be considered when facing a solid hypervascular abdominal or retroperitoneal mass. A better knowledge of this disorder and its characteristic would help surgeon to avoid unnecessarily extensive resection for this benign disorder when dealing with abdominal or retroperitoneal tumors. Surgical resection is curative for the localized form, when complete, while splenectomy could be indicated for the systemic form.
BACKGROUND: Since the Edmonton trial in 2000, increasing numbers of transplant centers have been implementing islet transplantation programs. Some institutions have elected to associate in multicenter networks, such as the Swiss-French GRAGIL (Groupe Rhin-Rhône-Alpes-Genève pour la Transplantation d'Ilots de Langerhans) consortium. METHODS: All pancreata offers to the University of Geneva Cell Isolation and Transplantation Center from within the network in 2002 and 2003 were reviewed. Islet preparations were attributed to the most suitable recipient on a centrally managed waiting list. All shipments were performed by ambulance in less than 5 hr. RESULTS: Over the period of study, 260 pancreata were offered, from a total of 1,304 cadaveric donors in the four allocation regions (20%). Fifty-two patients were on the waiting list at any time during this 2-year period. The percentage of organs offered varied in the range of 0.5% to 42%, depending on region of origin, with a correlation with number of patients on the waiting list in each region. Of these, 104 (40%) were accepted for processing. Ninety-two pancreata were actually processed, resulting in 42 islet preparations being transplanted. The number of international equivalents of transplanted preparations was 378,500+/-16,000 versus 165,400+/-15,400 (P<0.0001) for nontransplanted preparations. Total cold ischemia time was 6+/-0.3 hr for transplanted preparations versus 6.7+/-0.4 hr for nontransplanted preparations (not significant). CONCLUSIONS.: A high rate of pancreas offers, successful isolation, and islet transplantation can be achieved in multicenter networks such as GRAGIL. Such an approach can expand both the donor pool and the recipient population.
PURPOSE: To assess prospectively the quality of life (QOL) of patients treated by preoperative radiotherapy (RT) and surgery for locally advanced rectal cancer. METHODS AND MATERIALS: We studied 53 patients treated with bi-fractionated RT (50 Gy in 40 fractions within 4 weeks) followed at a median interval of 45 days by abdominoperineal resection in 11 patients and low anterior resection in 42 patients. Their QOL was assessed using two self-rating questionnaires developed by the European Organization for Research and Treatment of Cancer (EORTC): one was cancer specific (EORTC QLQ-C30) and one was site specific (EORTC QLQ-C38). The questionnaires were completed before RT and 12-16 months after RT, at which time 17 patients had undergone colostomy. We hypothesized that at least some scores of the various scales would vary between the two analyses. RESULTS: Compared with the pre-RT scores, at 1 year, patients reported statistically significant improvement in their emotional state (median 75 vs. 100, p <0.0001), perspective of the future (67 vs. 100, p = 0.0004), and their global QOL (75 vs. 83, p = 0.0008), as well as a decrease in GI symptoms (13 vs. 0, p = 0.002). However, the sexual dysfunction score increased significantly, particularly in men (17 vs. 83, p = 0.0045), and a trend toward a lower body image score was observed (100 vs. 89, p = 0.068). At 1 year, patients with colostomies reported similar or significantly improved symptom scores for fatigue, pain, GI problems, and sleep disturbance, but no such improvements were observed in patients without stomas. CONCLUSION: One year after combined treatment for locally advanced rectal cancer, patients exhibited statistically significant improvement in some important QOL outcomes, including global QOL, despite a decrease in sexual function and body image. Any additional improvement in QOL outcome may require refinements in the RT and surgical techniques to reduce late sequelae, particularly sexual dysfunction. Our results suggest that QOL considerations do not justify sphincter-conserving approaches if locoregional tumor control would be compromised.
BACKGROUND: T cells and macrophages play a major role in the rejection of xenografted islets. Depending on the phylogenetic disparity, direct or indirect antigen presentation is predominant. The aim of this study was to analyze in vitro the predominance of direct or indirect presentation by depleting antigen-presenting cells in concordant and discordant xenogeneic combinations. In vivo, we analyzed the effect of macrophage depletion on concordant and discordant islet xenograft survival to assess in which combination this strategy can be used as therapeutic tool. MATERIALS AND METHODS: In vitro, we performed mouse anti-rat and anti-human mixed lymphocyte reactions (MLR) after depletion of responder or stimulator antigen-presenting cells by magnetic sorting. In vivo, streptozotocin-induced diabetic C57BL/6 mice were treated by gadolinium chloride (GdCl) to deplete macrophages, and rat or human islets were transplanted under the kidney capsule. Islet function was followed by glycemia, and xenografts were analyzed at regular intervals for histology and immunohistochemistry. RESULTS: Mouse anti-rat MLR showed a predominant direct antigen presentation pathway, whereas in mouse anti-human MLR, direct and indirect pathways were similarly involved. Survival of rat islets was not modified by GdCl therapy. In contrast, survival of human islets was significantly prolonged in GdCl-treated mice. Macrophage infiltration was decreased in concordant and discordant GdCl-treated xenografts at day 4 compared with controls. At day 15, macrophage, CD4+, and CD8+ cell infiltration was similar in all groups. CONCLUSIONS: Our results indicate that direct antigen presentation is dominant in the rejection mechanism of concordant islet xenografts and cannot be influenced by host macrophage depletion. Both direct and indirect antigen presentation are involved in rejection of discordant xenogeneic islets. Macrophage depletion should only be considered as therapeutic tool for discordant islet xenotransplantation.
The aim of our study was to assess cell trafficking and early events after intraportal islet transplantation. Sprague-Dawley rat islets were incubated for various times, with various concentrations of 2-[F]fluoro-2deoxy-D-glucose (FDG), and in presence of various glucose concentrations. FDG-labeled syngeneic islets or FDG alone were injected in rats. Radioactivity was measured in the liver and in various organs by positron-emission tomography for 6 hours. FDG uptake increased with incubation time or FDG concentration and decreased in presence of glucose. In vivo, all islets implanted in the liver, with an uptake 4.4 times higher than controls (44.2% vs. 10.1%, P=0.02). Radioactivity in the liver decreased at the same rate after injection of labeled-islets and FDG alone. Ex vivo labeling of islets and imaging of posttransplant early events were feasible. Islets engrafted exclusively in the liver. No islet loss could be demonstrated 6 hours after transplantation.
BACKGROUND: Due to its unspecific presentation, intussusception is often diagnosed with delay in adults. METHODS: From 1986 to 2002, ten patients (men/women: 8/2, median age: 53.6 years) were managed for intussusception. Clinical, radiological and surgical management data were retrospectively analyzed. RESULTS: All patients presented with abdominal symptoms (pain: 10/10, nausea and vomiting: 3/10, diarrhoea: 2/10, "red-currant jelly stool": 2/10) during a median time of 8.3 months (2 days - 6 years) and with a trend for longer duration of symptoms for benign compared to malignant underlying disease (2 years vs 1 month). Two cases had developed acute bowel obstruction at the time of surgery. CT-scan was always performed, with correct diagnosis in seven cases. Ultrasonography (4/10), contrast enema (5/10) or coloscopy (4/10) either missed the intussusception or served merely to confirm the CT diagnosis. At surgery, an underlying lesion (six malignant and four benign tumours) was identified and removed in all cases (four small bowel, three right colon, two ileocaecal and one left colon resections). Eight were undiagnosed previously. CONCLUSIONS: Intussusception is rare in adults, but should be considered in cases of chronic or acute bowel obstructions. Early surgical management allows detection and potential cure of underlying tumours.
BACKGROUND: Biologic characteristics of enzyme products used for islet isolation are critical for the success of islet transplantation. In particular, lot-to-lot variability significantly affects the yields of the isolation procedure. In this study, we have evaluated a new enzyme preparation in which highly purified collagenase can be blended with separately supplied neutral protease in a predetermined ratio. METHODS: We compared the results of human-islet isolations performed either with Collagenase NB1 supplemented with Neutral Protease NB (group I, n=9) or with Liberase (group II, n=9). RESULTS: Endotoxin contents of the enzyme preparations were lower in group I. Total islet yields were similar in both groups, but islet equivalents per gram of pancreas was higher in group I (4,020+/-1,240 vs. 2,360+/-1,350; P<0.05). Islet morphology was improved in group I with significantly higher proportion of free and intact islets (71+/-9% vs. 52+/-14%; P<0.01). In vitro function was improved and apoptosis rate was lower in group I. CONCLUSIONS: This new enzyme blend was as efficient as Liberase in terms of islet yields and showed improvements in islet morphology, viability, and in vitro function. The possibility to control lot-to-lot variability and the low endotoxin contents make Collagenase NB1 a promising product for human-islet isolation.
Adenocarcinoid of the appendix is an infrequent tumor with histologic features of both adenocarcinoma and carcinoid tumor. Although its malignant potential remains unclear, adenocarcinoids seem to be biologically more aggressive than conventional carcinoids. The aim of this study was to analyze long-term results of surgical treatment for appendiceal adenocarcinoid. A retrospective review (1991-2003) identified seven patients (median age 72, range 27-81 years) treated for appendiceal adenocarcinoid. The clinical data of these patients were reviewed. Follow-up was complete for all patients (median 60 months, range 24-108 months). Most cases presented with associated acute appendicitis (71%). First intention surgery consisted of appendectomy (m = 6) and right hemicolectomy (m = 1). In three patients, additional surgical procedures were performed (right colectomy). Indications for colectomy were tumor size (three cases) associated with appendectomy margin invasion in one case. One patient with lymph node and peritoneal involvement experienced recurrence 9 months after hemicolectomy and died of the disease at 2 years. One patient subsequently died of colon carcinoma 6 years after adenocarcinoid treatment. Five patients were alive without disease at the time of the last follow-up. Synchronous or metachronous colon carcinomas developed in three patients (43%). Our results suggest that appendectomy alone could be used for appendiceal adenocarcinoid provided that the tumor (1) is less than 1 cm; (2) does not extend beyond the appendix adventitia; (3) has less than 2 mitoses/10 high power fields; and (4) has surgical margins that are tumor free. Otherwise, carcinologic right colectomy seems to be indicated. The risk for developing colorectal adenocarcinoma seems to be extremely high in patients treated for appendiceal adenocarcinoid and warrants close follow-up with colonoscopic screening.
PURPOSE: This study was undertaken to assess the incidence of 1) metachronous colorectal cancer and 2) subsequent extracolonic cancers, in relation to the location (proximal or distal to the splenic flexure) of the first primary colorectal tumor. METHODS: In this population-based study, a cancer registry database was used to identify patients diagnosed with colorectal adenocarcinoma between 1970 and 1999. Patients with familial adenomatous polyposis and those with hereditary nonpolyposis colorectal cancer syndrome were excluded from the study, as were patients with nonepithelial tumors. Location of the first tumor was established according to International Classification of Diseases-Oncology-02 classification. The registry covers a population of 500,000 residents. RESULTS: A total of 5,006 patients had sporadic adenocarcinoma of the colon or rectum during this period of time, with 1,703 first primary tumors (34 percent) being located proximal to the splenic flexure. One hundred twenty occurrences of second primary colorectal cancer were observed in this population (2.39 percent). The risk for developing a second incidence of primary colorectal cancer was higher in patients whose initial tumor was located in the proximal colon (3.4 percent vs. 1.8 percent; odds ratio, 1.92; 95 percent confidence interval, 1.33-2.77; P < 0.001). The risk for each segment of the large bowel was as follows: cecum, 3.4 percent; right colon, 3 percent; transverse colon, 3.8 percent; left colon, 2.8 percent; sigmoid colon, 1.7 percent; and rectum, 1.8 percent. By contrast, the risk for developing a second, extracolonic tumor did not differ between patients with proximal and distal tumors (13.7 percent vs. 13.4 percent, P = 0.73). CONCLUSION: Patients with a first tumor located within the proximal colon are at twice the risk for developing metachronous colorectal cancer. From an epidemiologic standpoint, these data are in accordance with 1) the increasing incidence and 2) the better prognosis of proximal colon cancer in various populations. Our results confirm that proximal colon cancer is a distinct entity, which justifies the reporting of cases of colon cancer according to their location proximal or distal to the splenic flexure.
Explore the source record for details and available documents.
BACKGROUND: Laparoscopic fundoplication effectively controls reflux symptoms in patients with gastroesophageal reflux disease (GERD). However, symptom relapse and side effects, including dysphagia and gas bloat, may develop after surgery. The aim of the study was to assess these symptoms in patients who underwent laparoscopic fundoplication, as well as in control subjects and patients with hiatal hernia. METHODS: A standardized, validated questionnaire on reflux, dysphagia, and gas bloat was filled out by 115 patients with a follow-up of 1 to 7 years after laparoscopic fundoplication, as well as by 105 subjects with an incidentally discovered hiatal hernia and 238 control subjects. RESULTS: Patients who underwent fundoplication had better reflux scores than patients with hiatal hernia ( P = .0001) and similar scores to control subjects ( P = .11). They also had significantly more dysphagia and gas bloat than patients with hiatal hernia and controls ( P < .005 for all comparisons). Gas bloat and dysphagia were more severe in hiatal hernia patients than in controls ( P < 0.005). After fundoplication, the 25% of the patients with the shortest follow-up (1.5 +/- 0.2 years) and the 25% patients with the longest follow-up (5.8 +/- 0.6 years) had similar reflux, dysphagia, and gas bloat scores ( P = .43, .82, and .85, respectively). CONCLUSION: In patients with severe GERD, laparoscopic fundoplication decreases reflux symptoms to levels found in control subjects. These results appear to be stable over time. However, patients who underwent fundoplication experience more dysphagia and gas bloat than controls and patients with hiatal hernia-symptoms that should be seen as a side effect of the procedure and of GERD itself.
BACKGROUND: The aim of this retrospective study was to evaluate clinical presentation and long-term outcome of patients treated surgically for complicated liver hydatid cysts. PATIENTS AND METHODS: Eighty-four patients with liver hydatid cysts underwent an operation at the Geneva University Hospital between 1980 and 1999. Clinical presentation, postoperative morbidity, mortality, and long-term recurrence rate were evaluated. RESULTS: Among the 84 patients with liver hydatid disease, 35 patients (41%) presented complicated cysts (ie, cysts that had developed a fistula into adjacent structures or organs). In most patients, the fistula communicated with the biliary tree (n = 25), but we also observed communication with the right lung (n = 3), the right diaphragm (n = 2), liver parenchyma (n = 1), and peritoneal cavity (n = 1). Complete removal of the cystic disease was possible in 24 of 35 patients (70%). In 11 patients, fragments of cysts were not removed because of their location adjacent to main vessels. Postoperatively, 8 patients (23%) developed a severe complication (grade II and III). There were no postoperative deaths, and no recurrences of hydatid disease were observed with a median follow-up of 8.6 years (complete follow-up was obtained in 69% of patients). CONCLUSIONS: Complicated liver hydatid disease is frequent and was observed in almost half of patients operated for liver hydatid cysts at our center. Using a surgical strategy aimed at complete removal of cystic and pericystic tissue with simultaneous treatment of the fistulous tract, we observed 23% postoperative morbidity, no mortality, and no recurrence of disease with a median follow-up of >8 years.
BACKGROUND: Simultaneous pancreas-kidney (SPK) transplantation has become the therapy of choice for type 1 diabetic patients with end-stage renal disease. The current analysis examined the impact of human leukocyte antigen (HLA) matching on graft outcome following SPK transplantation. The study population was obtained from patients enrolled in the Euro-SPK 001 study. METHODS: The effect of HLA matching on graft function and survival was assessed in 180 SPK recipients in whom complete donor-recipient HLA data were available. A group of 45 patients with 0-3 HLA mismatches (MM) was compared with a group of 135 patients with 4-6 MM. RESULTS: There were no differences in 3-year kidney, pancreas or patient survival between the 0-3 and 4-6 MM groups. Biological parameters of kidney and pancreas graft function were similar in both groups. Significantly more patients with 0-3 MM (66%) were rejection-free at 3 years than was the case among those with 4-6 MM (41%; P = 0.003). The relative risk of acute rejection was 2.6 times higher among patients with 4-6 MM than among those with 0-3 MM. CONCLUSIONS: There was no evidence that HLA matching was associated with improved kidney or pancreas survival. However, a higher rate of acute rejection was observed with poor HLA match, which may impact long-term survival.
BACKGROUND: The aim of this study was to evaluate in vitro and in vivo functions of isolated hepatocytes after immortalization, cryopreservation, encapsulation and xenotransplantation into mice with fulminant liver failure (FLF). METHODS: Rat and human hepatocytes were isolated from normal liver tissue by collagenase digestion. Human hepatocytes were immortalized using lentiviral vectors coding for SV 40 large T antigen, Bmi-1 and telomerase. Rat and immortalized human hepatocytes (IHH) were encapsulated in 400 micron alginate-PLL-alginate membranes and cryopreserved using a computerized device. In vitro, encapsulated hepatocytes (cryopreserved or freshly isolated) were cultured in albumin-free medium and albumin production was measured by enzyme-linked immunosorbent assay (ELISA). In vivo, a model of FLF was established in C57/BL6 mice by acetaminophen administration (700 mg/kg i.p.) followed 15 h later by a 30% hepatectomy. Microencapsulated (cryopreserved or freshly isolated) hepatocytes were transplanted intraperitoneally to mice with FLF and the following experimental groups were performed: group 1 (n = 10) Tx of empty capsules; group 2 (n = 12) Tx of free primary rat hepatocytes; group 3 (n = 12) Tx of cryopreserved encapsulated rat hepatocytes; group 4 (n = 10) Tx of fresh encapsulated rat hepatocytes; group 5 (n = 9) Tx of cryopreserved encapsulated IHH; group 6 (n = 10) Tx of fresh encapsulated IHH. Animals were killed at regular intervals and histopathology of microcapsules and liver tissue was obtained. RESULTS: In vitro, cryopreserved or fresh encapsulated rodent hepatocytes showed a progressively decreasing albumin secretion over 1 week in culture. In contrast, cryopreserved or fresh encapsulated IHH showed minimal, but stable albumin secretion. In vivo, FLF was achieved by combination of acetaminophen with 30% hepatectomy, resulting in a reproducible survival of 23% +/- 5%. In groups 1 and 2, survival rates were not improved significantly compared with untreated mice. In groups 3 and 4, Tx of cryopreserved or fresh encapsulated rat hepatocytes significantly increased survival rate to 66% and 80%, respectively (P < 0.01). In groups 5 and 6, Tx of cryopreserved or fresh encapsulated IHH improved survival to 50% and 55%, respectively (P < 0.05). Histopathology revealed that encapsulated hepatocytes were viable up to 2 weeks post-Tx. CONCLUSIONS: Primary rodent hepatocytes maintained synthetic functions after encapsulation and cryopreservation short-term. IHH showed minimal albumin secretion in the absence of encapsulation and cryopreservation, suggesting that hepatocytes loose specific functions after immortalization. After induction of FLF in mice, intraperitoneal Tx of encapsulated (primary or immortalized, fresh or cryopreserved) xenogeneic hepatocytes significantly improved survival. These results indicate that naïve and genetically modified hepatocytes can successfully be encapsulated, stored using cryopreservation, and be transplanted into xenogeneic recipients with liver failure and sustain liver metabolic functions.
The aim of the study was to investigate microbiological contamination rate during human pancreatic islet isolation. Between 1996 and 2002, pancreas preservation media and post-purification islet preparations were screened for microbiological contamination. After arrival in the laboratory, pancreata were washed prior to enzyme perfusion with either Hank's balanced salt solution (Group I, n = 170, 1996 to 2001) or decontaminated with polyvidonum-iodine, cefazoline, and amphotericine B (Group II, n = 45, 2001 to 2002). Microbiological contamination of preservation media was observed in 56% and 84% for Groups I and II, respectively. Analysis of contaminants revealed 74% Gram-positive, 21% Gram-negative bacteria and 5% fungi. Duration of transport had an influence on the rate of contamination (P < 0.05). After islet isolation, Group I presented microbial contamination of 16 islet preparations (9.4%) [i.e. Gram-positive bacteria (n = 10), Gram-negative bacteria (n = 4), and fungi (n = 2)]. In Group II, only 2 islet preparations (4.4%) presented microbial contamination. Microbial contamination during pancreas procurement occurs frequently. Most microorganisms are eliminated during islet isolation, and de novo contaminations during islet isolation are rare. Pancreas decontamination reduces the risk of infection of the final islet preparation.