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Biomedical subjects

B Nordlinger

Publications and source records attributed to B Nordlinger.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Intraperitoneal transplantation of isolated hepatocytes of the pig: the implantable bioartificial liver].

The general aim is to prepare a bioartificial liver to treat acute hepatic failure using allo- and xenogeneic hepatocytes, immunoprotected by macroencapsulation and transplanted into the peritoneal cavity. The goal of this study was to prepare a large amount of isolated porcine hepatocytes, to encapsulate them within biocompatible membranes for transplant in allo- and xenogeneic combinations and to examine the viability and functionality of the cells 6 weeks later. Hepatocyte isolation was performed in 12 kg pigs (n = 15) by dissociation of the liver with collagenase D (1 g) without oxygenation. Encapsulation of the hepatocyte suspension (10(7)/mL) was performed in hydrogel membranes AN69; hollow fibers (2 m x 0.8 mm) and flaskes (1.8 cm), and transplanted to Yucatan pigs (n = 4) and Lewis rats (n = 12). Six weeks later, they were removed to study the cell viability by histological examination, and the production of albumin by immunonephelometry. The rate of isolated hepatocytes was 38 +/- 5 x 10(9)/mL by liver of pig and the mean viability was 93 +/- 2%. Six weeks after transplantation, hepatocytes were viable, organized in lobules, and showed conserved albumin production. The same results were observed for allogenic and xenogeneic combinations. In conclusion, this method of liver dissociation allowed for preparation of a large amount of isolated hepatocytes from a single pig liver, theoretically sufficient to treat a patient with acute liver failure. Hydrogel membranes were well tolerated and allowed immunoprotection without immunosuppression. Transplanted hepatocytes remained functional. This work is an important step in progress toward clinical application.

Animals↗
PubMed1998

Encapsulated xenogeneic hepatocytes remain functional after peritoneal implantation despite immunization of the host.

BACKGROUND/AIMS: Xenogeneic hepatocytes encapsulated in semipermeable membranes could be used in the future for the treatment of acute liver failure and congenital liver defects. However, host immune response could affect the viability and function of transplanted cells. The purpose of this study was to investigate the immunological consequences of intraperitoneal implantation of encapsulated xenogeneic hepatocytes and their effects. METHODS: Recipient Lewis rats received 2 x 10(7) human hepatocytes encapsulated in semipermeable hydrogel-based hollow fibers, 2 x 10(7) free human hepatocytes or 2 x 10(7) encapsulated Lewis rat hepatocytes. The presence of human albumin in rat sera was assessed by Western blot and the presence of anti-human hepatocytes and anti-human albumin antibodies by ELISA. RESULTS: Anti-hepatocyte antibodies were detected on the 7th day, and their level increased progressively on days 21 and 28 in rats grafted with encapsulated or free human hepatocytes. Anti-albumin antibodies were detected on day 7 and increased progressively in rats grafted with encapsulated human hepatocytes, but were not detected in the other groups. No immune complexes or complement components of donor origin were detected by immunofluorescence in the recipients' tissues. Despite immunization of the host, encapsulated xenogeneic hepatocytes survived and produced albumin, whereas free hepatocytes had been lysed. CONCLUSION: Transplantation of encapsulated xenogeneic hepatocytes resulted in immunization of the host with production of anti-hepatocyte and anti-albumin antibodies. However, hepatocytes could be efficiently protected by the membrane and remained viable and functional during the study.

Animals↗
PubMed1998

Internal bioartificial liver with xenogeneic hepatocytes prevents death from acute liver failure: an experimental study.

OBJECTIVE: To demonstrate that a bioartificial liver, using allogeneic or xenogeneic hepatocytes protected from rejection by a semipermeable membrane, could prevent death from acute liver failure. SUMMARY BACKGROUND DATA: An implantable bioartificial liver using isolated hepatocytes could be an alternative to orthotopic liver transplantation to treat patients with acute liver failure. It could serve either as a bridge until liver transplantation or as the main treatment until recovery of the native liver. However, allogeneic or xenogeneic hepatocytes that could be used in clinical applications are spontaneously rejected. METHODS: Acute liver failure was induced in rats by 95% liver resection. Twenty-five million hepatocytes harvested in rats (allogeneic) or guinea pigs (xenogeneic) were encapsulated in a semipermeable membrane to protect them from rejection. The hollow fibers containing hepatocytes were transplanted into the peritoneum of recipient rats. Survival rates were compared between rats transplanted or not with hepatocytes. RESULTS: In groups not transplanted with viable hepatocytes, 73% to 93% of rats died after 95% liver resection. The mortality rate was reduced to 39% in rats transplanted with allogeneic hepatocytes and 36% in rats transplanted with xenogeneic hepatocytes. The bioartificial liver could be removed 1 month after transplantation, when regeneration of the native liver was complete. Allogeneic and xenogeneic hepatocytes remained viable. CONCLUSIONS: The implantable bioartificial liver was able to prevent death in this model of acute liver failure. This could be an important step toward clinical application of the method.

Animals↗
PubMed1998

Overexpression of stromelysin-3, BM-40/SPARC, and MET genes in human esophageal carcinoma: implications for prognosis.

Molecular markers can improve staging and predict aggressive clinical behavior in esophageal cancer, thus helping to define appropriate therapeutic protocols and to identify patients who will benefit from surgery. We therefore characterized, by Northern blot and/or immunohistochemistry, the relative expression of three effectors involved in the invasion, angiogenesis, and dissemination of tumor cells in esophageal cancer versus nontumoral mucosae: (a) stromelysin-3 (ST3), a member of the metalloproteinase family; (b) basement membrane 40/secreted protein acidic and rich in cysteine (BM-40/SPARC), an extracellular matrix-associated protein involved in angiogenesis; and (c) the hepatocyte growth factor receptor MET, which triggers the scattering of epithelial cells. Results were analyzed in relation to clinicopathological parameters (cpTNE) including tumor size (T), lymph node status (N), periesophageal tissue invasion (E), disease recurrence, and overall survival. The ST3, BM-40/SPARC, and MET genes were found to be overexpressed in tumor samples compared to control mucosa. BM-40/SPARC and MET mRNA levels were not linked to any one of the cpTNE, indicating that this overexpression occurs at an early stage of neoplastic progression. In contrast, ST3 expression, identified by immunohistochemistry in fibroblastic cells surrounding neoplastic islets, correlated with tumor size and periesophageal tissue invasion. Of the 36 patients studied, those with high ST3 levels had shorter disease-free survival than those with low levels, but there was no relationship between the cpTNE and disease recurrence or survival. Our study demonstrates that ST3, BM-40/SPARC, and MET are involved in different steps of esophageal carcinogenesis and that ST3 overexpression is a marker of aggressive clinical behavior. We conclude that in esophageal cancer, ST3 might help to assess survival and the risk of recurrence after surgical resection.

Adenocarcinoma↗
PubMed1997

Evidence for survival and metabolic activity of encapsulated xenogeneic hepatocytes transplanted without immunosuppression in Gunn rats.

BACKGROUND: Hepatocyte transplantation could be an alternative to whole organ transplantation to correct enzymatic disorders. To this end, it would be of major importance to use xenogeneic cells without immunosuppression. The aim of this study was to investigate the survival and metabolic activity of encapsulated xenogeneic hepatocytes in the absence of immunosuppression. For this purpose, we used Gunn rats genetically incapable of bilirubin conjugation. METHODS: Xenogeneic (from guinea pigs) and allogeneic (from Lewis rats) hepatocytes (2x10(7)) were isolated, macroencapsulated in hydrogel hollow fibers made with an acrylonitrile-sodium methallyl-sulfonate copolymer, and transplanted into the peritoneum of Gunn rats without any immunosuppression. Plasma bilirubin levels were evaluated weekly. Bilirubin conjugates in bile and cell morphology were studied after 5 and 12 weeks, respectively. RESULTS: In Gunn rats transplanted with xenogeneic hepatocytes, a significant decrease in the serum bilirubin level was observed between 3 and 9 weeks after transplantation when compared with controls transplanted with empty hollow fibers: it fell to 62% of the initial level at weeks 5-7 (P < 0.01). A comparable result was observed in Gunn rats transplanted with encapsulated allogeneic cells. Bilirubin conjugates were observed in bile samples of rats transplanted with encapsulated hepatocytes. After explantation, hollow fibers appeared intact with minimal fibrosis. Cell viability and hepatocyte morphology were preserved. CONCLUSIONS: These results indicate that macroencapsulated xenogeneic hepatocytes can survive and remain functional for more than 2 months when transplanted in vivo in the absence of any immunosuppression.

Acrylic Resins↗
PubMed1997

Administration of exogenous interleukin-2 abrogates spontaneous rat liver allograft acceptance but does not affect long-term established graft survival.

BACKGROUND: Spontaneous tolerance to the orthotopic liver allograft uniformly occurs in the DA (RT1a) to PVG (RT1c) rat combination despite a fully allogeneic barrier. METHODS: To assess whether spontaneous acceptance might be the consequence of a T cell help deficit at the time of the first exposure of alloantigens to the host, we studied the effect of exogenous interleukin (IL)-2 injections at the time of liver transplantation and during long-term follow-up. RESULTS: Although spontaneous acceptance of the liver allograft constantly ensued in the DA to PVG combination, a daily injection of recombinant IL-2 (3 x 10(5) U) uniformly provoked acute cellular rejection of the liver allograft and consequently the death of animals by postoperative day 5-6. Simultaneous to the graft loss, hepatic enzymes (alanine aminotransferase) increased more than 50-fold in IL-2-treated recipients, whereas similar IL-2 treatment did not produce any hepatic dysfunction in syngeneic animals. By immunohistology, the expression of the alpha chain of the IL-2 receptor, usually undetectable in untreated animals, was evident on CD4 and CD8 lymphocytes infiltrating the liver graft. In contrast, a similar IL-2 regimen and even higher IL-2 doses (x 10(6) U) did not abrogate the liver allograft survival during long-term follow-up. CONCLUSIONS: Our results demonstrate that spontaneous rat liver allograft acceptance may be abolished by exogenous IL-2 injections, which suggests that an "inherent T cell help deficit" might be implicated in the spontaneous acceptance mechanisms of DA to PVG liver allografts.

Alanine Transaminase↗
PubMed1997

Long-term survival following resection of colorectal hepatic metastases. Association Française de Chirurgie.

AIM: The aim of this study was to analyse characteristics of patients who survived more than 5 years after liver resection of colorectal metastases. METHODS: A multicentre retrospective study collected 1818 patients who underwent curative resection of hepatic metastases between 1959 and 1991. Among the 747 patients operated on before 1987, 102 survived longer than 5 years, and were compared with patients who survived less than 5 years. RESULTS: Three risk factors proved independently significant in multivariate analysis between the two groups: serosa infiltration (P = 0.003), involvement of peritumoral lymph nodes around the primary colorectal tumour (P = 0.04), and a liver resection margin of less than 1 cm (P = 0.02). There was no significant difference for other parameters studied (location of primary tumour, location, number and size of metastases, type of resection). A trend towards a shorter survival of patients with increased carcinoembryonic antigen serum level was observed. CONCLUSION: Resection of colorectal hepatic metastases can provide long-term survival even in patients with poor prognostic factors. It seems justified to undertake resection of colorectal liver metastases whenever it may be performed safely as a curative treatment.

Carcinoembryonic Antigen↗
PubMed1997

Radical surgery and postoperative radiotherapy as combined treatment in rectal cancer. Final results of a phase III study of the European Organization for Research and Treatment of Cancer.

BACKGROUND: There is controversy whether adjuvant radiotherapy should be given before or after surgery for locally advanced, resectable rectal cancer. Preoperative radiotherapy substantially reduces local recurrence rates but may increase postoperative complications. In addition, patients found to have early cancers are treated unnecessarily. This study is a randomized trial of postoperative radiotherapy in patients who had a potentially curative resection for locally advanced rectal carcinoma. METHODS: Following complete excision of a Dukes B or C rectal cancer, 172 patients were randomized to adjuvant radiotherapy (46 Gy 5 days per week in 30-38 days) (84 patients) or controls (88 patients). RESULTS: After a median follow-up of 85 months, no benefit from postoperative radiotherapy had been observed in disease-free survival (P = 0.81), overall survival (P = 0.52), local recurrence-free interval (P = 0.46) or in the number and sites of recurrence. Acute toxicity following radiotherapy included diarrhoea (20 per cent), cystitis (13 per cent), delayed wound healing (7 per cent), pneumonia (5 per cent) and seizures (1 per cent). Late complications included reoperation for small bowel obstruction (5 per cent), chronic diarrhoea (20 per cent), chronic cystitis (12 per cent) and persistent perineal sinus (9 per cent). In the group who had surgery alone, late morbidity was found in 11 per cent. CONCLUSION: This trial failed to demonstrate any improvement in overall survival or local control when postoperative irradiation was given following resection of locally advanced rectal carcinoma.

Adult↗
PubMed1996

[Cancer of the upper 3rd of the extra-hepatic bile ducts: surgical indication].

OBJECTIVES: Evaluate the surgical approach of curative resection in patients treated for cancer of the hepatic hilus. METHODS: We made a retrospective analysis of 50 cases collected between 1982 and 1994. Preoperative work-up was progressively centered on ultrasonography and Doppler examinations together with transhepatic cholangiography. Surgery was performed in 39 patients; surgery was not attempted in 11 patients in poor health status or with advanced stage disease. RESULTS: Curative resection was performed in 14 of the 39 operated patients. There were no hospital deaths and mean survival at 5 years was 60%. Median survival was 23 months. A palliative procedure was used in 25 patients with 3 deaths and a 7-month median survival. Transhepatic intubation of the bile ducts was performed in the 11 non-operated patients: there were 3 deaths and median survival was 3 months. CONCLUSIONS: A surgical approach, based on a simple preoperative work-up and extensive surgical exploration together with extemporaneous pathology can detect cases in which curative surgery is indicated. Care for operated patients given only palliative treatment is not compromised with this attitude and results are at least as good as those obtained with endoscopic or transhepatic intubation.

Adenocarcinoma↗
PubMed1996

Surgical resection of colorectal carcinoma metastases to the liver. A prognostic scoring system to improve case selection, based on 1568 patients. Association Française de Chirurgie.

BACKGROUND: Five-year survival rates after resection of liver metastases from colorectal carcinoma are close to 25%. Recurrences occur in two-thirds of the patients after surgery. Selection of patients likely to benefit from surgery remains controversial and subjective. METHODS: Data from 1568 patients with resected liver metastases from colorectal carcinoma were collected. The prognostic value of different factors was studied through uni- and multivariate analyses. A scoring system was developed including the most relevant factors. RESULTS: Two- and 5-year survival rates were 64% and 28%, respectively, and were affected by: age; size of largest metastasis or CEA level; stage of the primary tumor; disease free interval; number of liver nodules; and resection margin. Giving one point to each factor, the population was divided into three risk groups three risk groups with different 2-year survival rates: 0-2 (79%), 3-4 (60%), 5-7 (43%). CONCLUSIONS: A simple prognostic scoring system was proposed to evaluate the chances for cure of patients after resection of liver metastases from colorectal carcinoma. The comparison between expected survival and estimated operative risk can help determine on an objective basis whether surgery is worthwhile. This system needs further prospective validation.

Aged↗
PubMed1996

Locoregional chemotherapy for adjuvant treatment of colorectal adenocarcinoma.

Adjuvant chemotherapy with 5-fluorouracil (5-FU) and levamisole administered intravenously for 1 year has proved to be effective after curative surgical resection of Dukes' stage C colon carcinomas. Locoregional chemotherapy aims at delivering drugs directly into the abdominal cavity or the liver using either intraperitoneal or intraportal route of administration. Theoretically, these routes of administration have several advantages. The drugs can be delivered at a high dose concentration to the most common site of recurrence (i.e. peritoneum and liver) with decreased systemic toxicity. This article reviews the present status of intraportal and intraperitoneal chemotherapy as adjuvant postoperative treatment for colorectal carcinoma with special attention to the results of prospective randomised trials. Some positive results confirm that both route of administration represent promising methods for adjuvant chemotherapy. However, currently there are insufficient data on which to make a clear-cut conclusion on real benefits. New trials are currently in progress to test new modalities using different drugs or different drug combinations, using both locoregional and systemic treatments, and may prove to be more effective than systemic chemotherapy alone in the adjuvant treatment of colorectal cancers.

Adenocarcinoma↗
PubMed1996

Ileal pouch-anal anastomosis as the first choice operation in patients with familial adenomatous polyposis: a ten-year experience.

BACKGROUND: The choice between ileal pouch-anal anastomosis (IPAA) and ileorectal anastomosis (IRA) in the treatment of patients with familial adenomatous polyposis remains controversial. The aims of this study were to assess our 10-year experience with proctocolectomy, endoanal mucosectomy, construction of an ileal reservoir pouch, and IPAA in a series of 171 patients with familial adenomatous polyposis and to compare the functional results after IPAA with those after IRA. METHODS: Data from patients treated by IPAA at one institution were prospectively accumulated from October 1983 to October 1993. Medical records of 171 consecutive patients were studied regarding morbidity and functional results. These functional results were compared with those of a series of 23 patients who underwent IRA at the same institution. RESULTS: One patient (0.6%) died after operation. Sixty-two patients (36%) had concomitant colorectal carcinoma, 36 of which tumors were invasive (15 stage A, 13 stage B, and 8 stage C). Forty-six patients (27%) had at least one postoperative complication, with 14 patients requiring reoperation (8%). Twenty-six patients (15%) had obstruction. Seven patients (4%) had pelvic sepsis, and one had transient impotence (0.6%). Only two patients (1%) had a typical episode of pouchitis. The mean follow-up was 29 months (range, 3 to 100 months); 101 patients were monitored for more than 1 year. Little difference was noted between bowel function after IRA and that after IPAA. The mean daytime stool frequency after IPAA was 4.2 with 26% of patients having an average of 1 bowel movement at nighttime, compared with a stool frequency of 3.0 and 13% of patients having night evacuation after IRA. Daytime continence was normal for 98% of patients after IPAA and for all the patients after IRA. Nighttime continence was normal in 96% and 98% of patients, respectively. CONCLUSIONS: Morbidity and functional results after IPAA for familial adenomatous polyposis do not differ from those reported after IRA. For this reason and because of the risk of rectal cancer after ileorectal anastomosis, IPAA with endoanal mucosectomy is our first choice in the treatment of patients with familial adenomatous polyposis.

Adenomatous Polyposis Coli↗
PubMed1996

Glutamine metabolism and neuropathological disorders in experimental hepatic encephalopathy: effect of transplanted hepatocytes.

BACKGROUND: Physiopathology of hepatic encephalopathy remains unclear. Recent studies have suggested that ammonia would not act by itself but through an increase in glutamine in the brain. We have previously demonstrated that transplantation of syngeneic hepatocytes into the spleen was able to correct both behavioral deficits and plasma amino acid changes observed in portacaval shunted rats. The aim of the present work was to show a correlation between the correction of chronic hepatic encephalopathy by means of intrasplenic hepatocyte transplantation and two parameters, brain glutamine concentration and ultrastructural aspects of astrocytes. METHODS: Inbred male Wistar Furth rats were divided into three groups: sham-operated rats (n = 10), rats subjected to portacaval shunt (n = 10), and rats subjected to portacaval shunt and intrasplenic hepatocellular transplantation of 10(7) hepatocytes isolated from livers of syngeneic rats (n = 10). Chronic hepatic encephalopathy was quantified 30 and 60 days after operation by means of nose-poke exploration and spontaneous activity. Pathologic examination and measurement of glutamine concentrations in the corpus striatus and in the cerebral cortex were performed 60 days after operation. RESULTS: Portacaval shunt rats showed reduced spontaneous activity and nose-poke exploration scores. After portacaval shunt a significant glutamine increase occurred in the corpus striatus and in the cerebral cortex when compared with sham rats (p < 0.05). Ultrastructural examination showed modification of astrocytes named Alzheimer type II after portacaval shunt. Correction of behavioral abnormalities by means of intrasplenic hepatocyte transplantation was associated with partial correction of striatal glutamine increase and with decrease in astrocyte alterations. Cortex glutamine concentration in portacaval shunt-intrasplenic hepatocyte transplantation group and in portacaval shunt rats did not differ significantly. CONCLUSIONS: These data show that intrasplenic hepatocyte transplantation not only prevents neurologic disorders of hepatic encephalopathy but can also decrease glutamine and ultrastructural alterations in the corpus striatus in an experimental model of chronic liver failure. These data are in favor of the involvement of glutamine in chronic hepatic encephalopathy. These results suggest that intrasplenic hepatocyte transplantation might be of therapeutic interest in chronic liver failure.

Animals↗
PubMed1996

Immunosuppressive effects of endotoxins and bile acids in vivo in the rat.

Cell-mediated immunity is impaired during cholestasis. The aim of this study was to evaluate in vivo the effects on this immune defect of high serum levels of endotoxin and bile acids. Heterotopic cardiac allotransplantations were performed in the DA/Lewis rat combination. Cholestasis, induced by ligation/section of the common bile duct, was responsible for a significant delay in the rejection time (16 +/- 0.5 vs. 7.1 +/- 0.4 days in controls, P < 0.01). Elimination of Gram-negative intestinal bacteria from cholestatic rats by a vancocin/colimycin/tobramycin (VCT) mixture induced a significant reduction in endotoxin levels and a reduction in rejection times (9.5 +/- 1.0 days, P < 0.01) that remained, however, significantly longer than those of controls (P < 0.05). Oral administration of chenodeoxycholic acid in non-cholestatic rats significantly enhanced the serum concentration of total bile acids (60.6 +/- 15.3 mumol L(-1) vs. 17.4 +/- 1.9 mol L(-1) in controls, P < 0.01) and postponed allograft rejection (10.7 +/- 0.6 days, P < 0.01 vs. controls). These data suggest that increased endotoxin level and serum bile acid concentration may play a role in the immunosuppressive effect of cholestasis.

Animals↗