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Biomedical subjects

Philippe Morel

Publications and source records attributed to Philippe Morel.

At least 19 recordsLinked to original sources

Successful treatment of recurrent focal segmental glomerulosclerosis after kidney transplantation by plasmapheresis and rituximab.

A 22-year-old patient whose primary kidney disease was focal segmental glomerulosclerosis (FSGS) developed severe recurrence of proteinuria (up to 57 g/24 h) immediately after a haploidentic living donor kidney transplantation despite pre-operative plasmapheresis. The immunosuppressive treatment consisted of tacrolimus, mycophenolate mofetil, basiliximab and steroids. He underwent 10 plasmapheresis sessions in the first 3-week post-transplantation. In addition, he received 2 i.v. doses of rituximab (RTX) 600 mg (375 mg/m(2)) on days 7 and 15. Proteinuria decreased below nephrotic range at day 14 and serum creatinine returned progressively to normal values. A short course of oral ciclophosphamide (100 mg/j) was administrated between days 22 and 40 and three additional plasmapheresis sessions on days 34, 39 and 49. This strategy allowed obtaining sustained full remission of the nephrotic syndrome (NS) and excellent graft function, which persists over 2 years after transplantation. No notable adverse events related to RTX or plasmapheresis were observed. This case suggests that RTX associated with plasmapheresis may be an effective treatment of recurrent NS because of FSGS.

Adult↗

A new method of biliary sampling for cytopathological examination during endoscopic retrograde cholangiography.

OBJECTIVES: Biliary brushing during endoscopic retrograde cholangiography (ERC) may allow the diagnosis of cancer, but this technique is limited by a low (18-57%) sensitivity. We compared the cellular and diagnostic yields of a new sampling method (using stricture dilation and a grasping basket) with those of brushing. METHODS: Sixty consecutive patients with a suspected malignant obstruction of the common bile duct were included in a consecutive, nonrandomized order. They underwent sampling during ERC using the new method (study patients, N = 30) or a brush (control patients, N = 30). A final diagnosis of cancer was made in 22/30 (73%) study patients and 21/30 (70%) control patients. At the end of the study period, all smears were interpreted at cytopathological examination in a blind and random fashion for cellularity (insufficient, low, moderate, or high) and diagnosis (normal, atypical considered reactive, highly atypical suspicious for cancer, or malignant). "Highly atypical" and "malignant" diagnoses were considered as indicative of cancer. RESULTS: Compared with biliary brushing, the new method provided a high cellular yield in more cases (19/30 vs 10/30, P= 0.020), a higher sensitivity for the detection of cancer (19/22 [86%] vs 11/21 [52%], P= 0.015), and a higher diagnostic accuracy (27/30 [90%] vs 20/30 [67%], P= 0.028). Specificity for the detection of cancer was 100%. The 30-d complication rate observed with the new method was 3%. CONCLUSIONS: Significantly higher cellular and diagnostic yields can be obtained at ERC in patients with suspected malignant biliary stricture by combining stricture dilation and a grasping basket compared with brushing.

Aged↗

International trial of the Edmonton protocol for islet transplantation.

BACKGROUND: Islet transplantation offers the potential to improve glycemic control in a subgroup of patients with type 1 diabetes mellitus who are disabled by refractory hypoglycemia. We conducted an international, multicenter trial to explore the feasibility and reproducibility of islet transplantation with the use of a single common protocol (the Edmonton protocol). METHODS: We enrolled 36 subjects with type 1 diabetes mellitus, who underwent islet transplantation at nine international sites. Islets were prepared from pancreases of deceased donors and were transplanted within 2 hours after purification, without culture. The primary end point was defined as insulin independence with adequate glycemic control 1 year after the final transplantation. RESULTS: Of the 36 subjects, 16 (44%) met the primary end point, 10 (28%) had partial function, and 10 (28%) had complete graft loss 1 year after the final transplantation. A total of 21 subjects (58%) attained insulin independence with good glycemic control at any point throughout the trial. Of these subjects, 16 (76%) required insulin again at 2 years; 5 of the 16 subjects who reached the primary end point (31%) remained insulin-independent at 2 years. CONCLUSIONS: Islet transplantation with the use of the Edmonton protocol can successfully restore long-term endogenous insulin production and glycemic stability in subjects with type 1 diabetes mellitus and unstable control, but insulin independence is usually not sustainable. Persistent islet function even without insulin independence provides both protection from severe hypoglycemia and improved levels of glycated hemoglobin. (ClinicalTrials.gov number, NCT00014911 [ClinicalTrials.gov].).

Adult↗

Lymph node retrieval in abdominoperineal surgical specimen is radiation time-dependent.

BACKGROUND: A low yield of lymph nodes (LN) in abdominoperineal resection (APR) specimen has been associated with preoperative radiation therapy (XRT) in population-based studies, which may preclude adequate staging of anorectal carcinomas. We hypothesized that the number of LN retrieved in APR specimen was correlated with the dose and the timing of pelvic irradiation. PATIENTS AND METHODS: We performed a retrospective study of 102 patients who underwent APR in a single institution between 1980 and 2004. Pathological reports were reviewed and the number of lymph nodes retrieved in APR specimens was correlated with: 1) Preoperative radiation; 2) Dose of pelvic irradiation; and 3) Time interval between the end of XRT and surgery. RESULTS: There were 61 men and 41 women, with a median age of 66 (range 25-89) years. There were 12 patients operated for squamous cell carcinoma of the anal canal (SCCA) and 90 for rectal cancer. 83% and 46% of patients with anal and rectal cancer respectively underwent radical/neoadjuvant radiotherapy. The mean +/- SD number of LN in APR specimen was 9.2 +/- 5.9. The mean number of LN in APR specimen was significantly lower in patients who underwent preoperative XRT (8 +/- 5.5 vs. 10.5 +/- 6.1, Mann-Whitney U test, p = 0.02). The mean number of LN was not significantly different after XRT in patients with SCCA than in patients with rectal cancer (6.2 +/- 5.3 vs. 7.8 +/- 5.3, p = 0.33). Finally, there was an inverse correlation between the yield of LN and the time elapsed between XRT and surgery (linear regression coefficient r = -0.32, p = 0.03). CONCLUSION: Our data indicate that: 1) radiation therapy affects the yield of LN retrieval in APR specimen; 2) this impact is time-dependent. These findings have important implications with regard to anatomic-pathological staging of anal and rectal cancers and subsequent decision-making regarding adjuvant chemotherapy.

Journal Article↗

Outcome of surgery for rectal cancer in octogenarians.

INTRODUCTION: The aim of this study was to assess the outcome of surgery for rectal cancer in patients 80 years of age or more. METHODS: A retrospective study of 29 patients older than 80 years, who presented in our institution between 1997 and 2001 with the diagnosis of rectal adenocarcinoma, was undertaken. RESULTS: Median follow-up was 54 (range 27-78) months, and the median age of patients was 85 (range 80-94) years. Twenty-four out of 29 patients (83%) underwent surgery, 23 being operated electively. Twenty out of 24 patients (83%) underwent resection with curative intent, while four patients (17%) had a palliative procedure. Median hospital stay was 13 (range 10-35) days. Postoperative morbidity and mortality were 46% and 12.5%, respectively. However, when considering only elective procedures with curative intent, operative mortality was 5%. At the time of last follow-up, 13 patients were alive, five of them with no evidence of recurrent disease at 5 years, for an overall 2- and 5-year survival rate of 80% and 67%, respectively. Four out of the 7 deaths, which occurred after surgery, were due to medical causes unrelated to cancer. CONCLUSION: In our institution, two thirds of patients older than 80 years who presented with rectal cancer underwent surgery with curative intent. In this selected population, good results in terms of short-term survival can be achieved, at the price of an elevated postoperative morbidity. Whenever possible, treatment with curative intent should be considered in patients with rectal cancer, irrespective of the age.

Aged, 80 and over↗

Soluble CD40 ligand in prediction of acute severe pancreatitis.

AIM: To assess the early predictability of the soluble CD40L (sCD40L) in pancreatitis severity. METHODS: Between February 2000 and February 2003, 279 consecutive patients with acute pancreatitis were prospectively enrolled in our study. In this report, 40 patients with mild and 40 patients with severe pancreatitis were randomly studied. sCD40L concentrations were measured 48 hours after admission. RESULTS: sCD40L levels were significantly higher 48 hours after admission in severe pancreatitis than in mild pancreatitis. Using a cutoff of 1000 pg/L, the sensitivity and specificity of sCD40L to detect a severe course of the disease were 78% and 62% respectively compared to 72% and 81% for CRP. Logistic regression analysis found that CRP was the only statistically significant marker able to detect a severe course of the disease. CONCLUSION: These findings indicate that CRP remains a valuable marker to determine the severity and prognosis of acute pancreatitis whereas sCD40L levels should be assessed in further studies.

Adult↗

Neutrophil depletion--but not prevention of Kupffer cell activation--decreases the severity of cerulein-induced acute pancreatitis.

AIM: To determine whether neutrophil depletion and Kupffer cell inhibition might combine their protective effects to decrease the severity of acute pancreatitis. METHODS: Mice had cerulein administration to induce acute pancreatitis and were pretreated with either anti-mouse neutrophil serum or gadolinium chloride (GdCl3) to prevent Kupffer cell activation, or both treatments. Injury was assessed in pancreas and lungs. Myeloperoxidases (MPO) assessed neutrophil infiltration. Interleukin-6 (IL-6) and IL-10 were measured in serum, pancreas, lungs and liver. RESULTS: In mice with acute pancreatitis, neutrophil depletion reduced the severity of pancreatitis and pancreatitis-associated lung injury. Kupffer cell inactivation by GdCl3 had less protective effect, although IL-6 and IL-10 concentrations were significantly decreased. The protective treatment brought by neutrophil depletion was not enhanced by Kupffer cell inactivation and both treatments did not combine their protective effects. CONCLUSION: Our results confirm the role of activated neutrophils in aggravating organ injury in acute pancreatitis while the role of Kupffer cell activation is less obvious.

Acute Disease↗

Epidural anaesthesia restores pancreatic microcirculation and decreases the severity of acute pancreatitis.

AIM: To investigate the effect of epidural anaesthesia (EA) on pancreatic microcirculation during acute pancreatitis (AP). METHODS: AP was induced by injection of sodium taurocholate into the pancreatic duct of Sprague-Dawley rats. To realize EA, a catheter was introduced into the epidural space between T7 and T9 and bupivacaine was injected. Microcirculatory flow was measured by laser Doppler flowmetry. Arterial blood gas analyses were performed. At the end of the experiment (<or=5 h), pancreas was removed for histology. The animals were divided into three groups: Group 1 (n=9), AP without EA; Group 2 (n=4), EA without AP; and Group 3 (n=6), AP treated by EA. RESULTS: In Group 1, pancreatic microcirculatory flow prior to AP was 141+/- 39 perfusion units (PU). After AP, microcirculatory flow obviously decreased to 9+/- 6 PU (P<0.05). Metabolic acidosis developed with base excess (BE) of -14+/-3 mmol/L. Histology revealed extensive edema and tissue necrosis. In Group 2, EA did not significantly modify microcirculatory flow. BE remained unchanged and histological analysis showed normal pancreatic tissue. In Group 3, AP initially caused a significant decrease in microcirculatory flow from 155+/-25 to 11+/-7 PU (P<0.05). After initiation of EA, microcirculatory flow obviously increased again to 81+/-31 PU (P<0.05). BE was -6+/-4 mmol/L, which was significantly different compared to Group 1 (P<0.05). Furthermore, histology revealed less extensive edema and necrosis in pancreatic tissue in Group 3 than that in Group 1. CONCLUSION: AP caused dramatic microcirculatory changes within the pancreas, with development of metabolic acidosis and tissue necrosis. EA allowed partial restoration of microcirculatory flow and prevented development of tissue necrosis and systemic complications. Therefore, EA should be considered as therapeutic option to prevent evolution from edematous to necrotic AP.

Acute Disease↗

Endothelial nitric oxide synthase regulation is altered in pancreas from cirrhotic rats.

AIM: To determine whether biliary cirrhosis could induce pancreatic dysfunction such as modifications in endothelial nitric oxide synthase(eNOS) expression and whether the regulation of eNOS could be altered by the regulatory proteins caveolin and heat shock protein 90 (Hsp90), as well as by the modifications of calmodulin binding to eNOS. METHODS: Immunoprecipitations and Western blotting analysis were performed in pancreas isolated from sham and cirrhotic rats. RESULTS: Pancreatic injury was minor in cirrhotic rats but eNOS expression importantly decreased with the length (and the severity) of the disease. Because co-immunoprecipitation of eNOS with both Hsp90 and caveolin similarly decreased in cirrhotic rats, eNOS activity was not modified by this mechanism. In contrast, cirrhosis decreased the calmodulin binding to eNOS with a concomitant decrease in eNOS activity. CONCLUSION: In biliary cirrhosis, pancreatic injury is minor but the pancreatic nitric oxide (NO) production is significantly decreased by two mechanisms: a decreased expression of the enzyme and a decreased binding of calmodulin to eNOS.

Animals↗

Morphologic alterations associated with mechanical bowel preparation before elective colorectal surgery: a randomized trial.

PURPOSE: The feasibility and safety of left-sided colorectal procedures with avoidance of mechanical bowel preparation has recently been demonstrated. Moreover, mechanical preparation has been associated with an increased risk for abdominal septic complications, including anastomotic leakage. This study was designed to determine whether mechanical bowel preparation is associated with histologic alterations in the colon. METHODS: Fifty patients (mean age, 61 (range, 45-78) years) scheduled to undergo elective colorectal surgery were prospectively randomized to receive mechanical preparation (polyethylene glycol; Group 1) or no preparation (Group 2) preoperatively. A macroscopically healthy segment of the bowel was excised at the proximal margin of the colectomy piece. A pathologist, blinded to the patient's group allocation, assessed various morphologic parameters. RESULTS: Indications for colectomy (cancer and complicated diverticulosis) did not differ between groups. Bowel wall alterations were more frequent in patients who received a preparation. The most striking alterations associated with mechanical preparation were loss of superficial mucus (moderate-to-severe in 96 and 52 percent in Groups 1 and 2, respectively; P < 0.001) and epithelial cells (moderate-to-severe in 88 and 40 percent in Groups 1 and 2, respectively; P < 0.01). In addition, inflammatory changes, i.e., lymphocytes (severe in 48 and 12 percent in Groups 1 and 2, respectively; P < 0.02) and polymorphonuclear cells infiltration (severe in 52 and 8 percent in Groups 1 and 2, respectively; P < 0.02), were more prevalent after mechanical preparation. CONCLUSIONS: Mechanical bowel preparation is associated with structural alteration and inflammatory changes in the large bowel wall. Although bowel wall inflammation is a known risk factor for anastomotic leak, it remains to be elucidated whether these changes have a direct relation to the deleterious effect of mechanical bowel preparation in terms of abdominal morbidity.

Aged↗

Tetracycline-regulated expression of VEGF-A in beta cells induces angiogenesis: improvement of engraftment following transplantation.

Early revascularization of pancreatic islet cells after transplantation is crucial for engraftment, and it has been suggested that vascular endothelial growth factor-A (VEGF-A) plays a significant role in this process. Although VEGF gene therapy can improve angiogenesis, uncontrolled VEGF secretion can lead to vascular tumor formation. Here we have explored the role of temporal VEGF expression, controlled by a tetracycline (TC)-regulated promoter, on revascularization and engraftment of genetically modified beta cells following transplantation. To this end, we modified the CDM3D beta cell line using a lentiviral vector to promote secretion of VEGF-A either in a TC-regulated (TET cells) or a constitutive (PGK cells) manner. VEGF secretion, angiogenesis, cell proliferation, and stimulated insulin secretion were assessed in vitro. VEGF secretion was increased in TET and PGK cells, and VEGF delivery resulted in angiogenesis, whereas addition of TC inhibited these processes. Insulin secretion by the three cell types was similar. We used a syngeneic mouse model of transplantation to assess the effects of this controlled VEGF expression in vivo. Time to normoglycemia, intraperitoneal glucose tolerance test, graft vascular density, and cellular mass were evaluated. Increased expression of VEGF resulted in significantly better revascularization and engraftment after transplantation when compared to control cells. In vivo, there was a significant increase in vascular density in grafted TET and PGK cells versus control cells. Moreover, the time for diabetic mice to return to normoglycemia and the stimulated plasma glucose clearance were also significantly accelerated in mice transplanted with TET and PGK cells when compared to control cells. VEGF was only needed during the first 2-3 weeks after transplantation; when removed, normoglycemia and graft vascularization were maintained. TC-treated mice grafted with TC-treated cells failed to restore normoglycemia. This approach allowed us to switch off VEGF secretion when the desired effects had been achieved. TC-regulated temporal expression of VEGF using a gene therapy approach presents a novel way to improve early revascularization and engraftment after islet cell transplantation.

Animals↗

The duration of postoperative ileus after elective colectomy is correlated to surgical specialization.

AIM: Postoperative ileus is an important factor of complications following gastrointestinal procedures. Its pathophysiology and the parameters, which may impact on its duration, remain unclear. The aim of this study was to measure the role of various clinical determinants on restoration of intestinal function after elective colorectal surgery. METHODS: From July 2002 to September 2003, all patients who underwent laparotomy for colectomy (laparoscopic resections excluded) with either an ileotransverse, colocolic, or high colorectal anastomosis were entered in this prospective study. The intervals in hours between the end of the surgical procedure and passing of flatus (PG) and passing of stool (PS) were recorded by an independent investigator. PG and PS were eventually correlated with the following parameters: type of colectomy, early removal of nasogastric tube (NGT), mechanical bowel preparation (MBP), type of underlying disease, systemic administration of opiates, and surgical training (colorectal fellowship or other). RESULTS: One hundred twenty-four patients were entered in this study. Four patients (3.2%) developed septic complications (3 anastomotic leaks and 1 intraabdominal abscess) and were excluded from the analysis. Median age in this population was 68 (range 30-95) years. Mean duration of postoperative ileus was 70+/-28 h (PG) and 99+/-34 h (PS). The type of colectomy, underlying disease, MBP, and early NGT removal failed, in univariate analysis, to correlate with the duration of postoperative ileus. By contrast, time intervals PG and PS were statistically shorter in the group of patients treated by a colorectal surgeon [56+/-23 vs 74+/-28 h (PG); 82+/-26 vs 103+/-35 h (PS), p=0.004], as well as in patients who received systemic opiates for less than 2 days [64+/-27 vs 75+/-28 h (PG), p=0.04; 88+/-32 vs 108+/-33 h (PS), p=001]. CONCLUSION: Restoration of normal intestinal function after elective open colectomy takes 3 (PG) to 4 (PS) days. In our series, specialized training in colorectal surgery has a positive impact on the duration of postoperative ileus. Surgical specialization should be considered an important parameter in future clinical trials aiming to minimize postoperative ileus.

Adult↗

Management of hepatocellular adenoma: solitary-uncomplicated, multiple and ruptured tumors.

AIM: While hepatocellular adenomas (HAs) have often been studied as a unique entity, we aimed to better define current management of the various forms of HAs. METHODS: Twenty-five consecutive patients operated for solitary-uncomplicated (9), multiple (6), and ruptured (10) HAs were reviewed according to management strategies and outcomes. RESULTS: All solitary-uncomplicated HAs (ranged 2.2-14 cm in size) were removed. Out of 25 HAs, 2 (8%) included foci of carcinoma. In the multiple HA group, previously undiagnosed tumors were identified during surgery in 5/6 cases. In three cases with multiple spread HA, several lesions had to be left unresected. They remained unmodified after 4-, 6-, and 6-year radiological follow-up. Patients with ruptured HA (ranged 1.7-10 cm in size) were initially managed with hemodynamic support and angiography, allowing the embolization of actively bleeding tumors in two patients. All ruptured tumors were subsequently removed 5.5 d (range 4-70 d) after admission. CONCLUSION: Tumors suspected of HA, regardless of the size, should be resected, because of high chances of rupture causing bleeding, and/or containing malignant foci. Although it is desirable to remove all lesions of multiple HA, this may not be possible in some patients, for whom long-term radiological follow-up is advised. Ruptured HA can be managed by hemodynamic support and angiography, allowing scheduled surgery.

Adenoma, Liver Cell↗

Neoadjuvant radiochemotherapy for locally advanced gastric cancer: long-term results of a phase I trial.

PURPOSE: To assess the long-term results of radiation therapy (RT) when added preoperatively to systemic chemotherapy in patients with locally advanced gastric cancer. METHODS AND MATERIALS: Patients presenting with T3-4 or N+ gastric cancer received two cycles of cisplatin 100 mg/m2 d1, 5FU 800 mg/m2 d1-4, and Leucovorin 60 mg twice daily d1-4; one cycle before and one concomitantly with hyperfractionated RT (median dose, 38.4; range, 31.2-45.6 Gy). All patients underwent a total or subtotal gastrectomy with D2 lymph node resection. RESULTS: Nineteen patients were accrued and 18 completed the neoadjuvant therapeutic program. All patients were subsequently operated and no fatality occurred. At a mean follow-up of 8 years for the surviving patients, no severe late toxicity was observed. The 5-year locoregional control, disease-free, and overall survival were of 85%, 41%, and 35%, respectively. The peritoneum was the most frequent site of relapse. Among long terms survivors, no severe (Radiation Therapy Oncology Group Grade 3-4) late complication was reported. CONCLUSIONS: The present neoadjuvant treatment does not seem to increase the operative risk, nor the late side effects. The encouraging locoregional control rate suggests that the neoadjuvant approach should be considered for future trials in locally advanced gastric cancer. Also, the frequency of peritoneal recurrence stresses the need for a more efficient systemic or intraperitoneal treatment.

Adult↗

Expression and secretion of alpha1-proteinase inhibitor are regulated by proinflammatory cytokines in human pancreatic islet cells.

AIMS/HYPOTHESIS: Alpha1-proteinase inhibitor (alpha1-PI) has been considered a key player in inflammatory processes. In humans, the main production site of alpha1-PI is the liver, but other tissues, including pancreatic islets, also synthesise this molecule. The aims of this study were to assess the islet cell types that produce alpha1-PI, to determine whether alpha1-PI is actually secreted by islet cells, and to assess how its production and/or secretion are regulated. METHODS: Expression of alpha1-PI in human islet cells was assessed by immunofluorescence, electron microscopy and western blotting. Release of alpha1-PI was analysed by reverse haemolytic plaque assay and ELISA. The effects of cytokines on alpha1-PI synthesis and secretion were tested. RESULTS: Immunofluorescence showed that alpha and delta cells do express alpha1-PI, whereas beta cells do not. By electron microscopy, we demonstrated a colocalisation of alpha1-PI with glucagon and somatostatin within secretory granules. Immunolabelling also revealed localisation of alpha1-PI within the Golgi apparatus, related vesicles and lysosomal structures. The expression of alpha1-PI in islet cells was also demonstrated by western blotting and ELISA of protein extracts. ELISA and reverse haemolytic plaque assay showed that alpha1-PI is secreted into the culture medium. Treatment of islet cells with IL-1beta and oncostatin M for 4 days increased the production and release of alpha1-PI. CONCLUSIONS/INTERPRETATION: Our results demonstrate that alpha1-PI is expressed by the alpha and delta cells of human islets, and that proinflammatory cytokines enhance the production and release of this inhibitor.

1-Methyl-3-isobutylxanthine↗

Treatment of acetaminophen-induced acute liver failure in the mouse with conditionally immortalized human hepatocytes.

BACKGROUND/AIMS: Liver failure is a life threatening condition currently treated by palliative measures and, when applicable, organ transplantation. The use of a bioartificial organ capable of fulfilling the main functions of the liver would represent an attractive alternative. However, the shortage of suitable donor cells, and their limited growth ability have impeded the development of this strategy. We investigated whether lentiviral vectors allow for conditional immortalization of human hepatocytes and whether these immortalized hepatocytes could reverse lethal acute liver failure. METHODS: We exposed primary human hepatocytes to Cre-excisable lentiviral vectors coding for SV40T Antigen, telomerase, and/or Bmi-1 and tested the functionality of the resulting cell lines. Therapeutic potential of immortalized hepatocytes were tested in a murine model of acetaminophen-induced hepatic injury. RESULTS: The immortalized hepatocytes grew continuously yet were non-tumorigenic, stopped proliferating when exposed to Cre recombinase, and conserved defining properties of primary hepatocytes, including the ability to secrete liver-specific proteins and to detoxify drugs. The implantation of encapsulated immortalized human hepatocytes rescued mice from lethal doses of acetaminophen. CONCLUSIONS: Lentiviral vectors represent tools of choice for immortalization of non-dividing primary cells, and lentivirally immortalized human hepatocytes are promising reagents for cell-based therapy of acute liver failure.

Acetaminophen↗