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Biomedical subjects

C Legendre

Publications and source records attributed to C Legendre.

At least 145 records · Page 8Linked to original sources

Augmentation of portal blood flow improves function of human cirrhotic liver.

In cirrhotic livers, the intrahepatic resistance is increased and drug elimination and portal transhepatic flow are decreased. The aim of our work was to study the effect of a twofold increase in portal blood flow during 2 hr on the hemodynamic parameters, drug elimination and hepatic viability in eight isolated perfused human cirrhotic livers. Using an oxygenated recirculating system with independent arterial and portal flows, we perfused livers with Kreb's buffer bicarbonate solution, bovine serum albumin (20 gm.L-1) and human red blood cells (hematocrit 20%). The flow was maintained at a basal level of 0.713 +/- 0.19 L/min for 1 hr and then increased and maintained for 2 hr at twice the basal flow. Portal pressure-portal flow curve slopes were linear (27.04 +/- 21.06 mm Hg.L-1 x min; range = 6.43 to 60.8) and correlated with intrahepatic resistance during the basal-flow period (r = 0.87, p < 0.01). Parameters registered during the basal- and high-flow periods were compared by use of Student's t test: portal pressure increased from 23.5 +/- 7 to 37.3 +/- 16.7 mm Hg (p < 0.05); arterial pressure increased from 80.3 +/- 19 to 103.5 +/- 26 mm Hg (p < 0.005); hepatic artery flow resistance increased 31.9% (from 690.1 +/- 218 to 899.4 +/- 269 mm Hg.L-1 x min; p < 0.005); indocyanine green clearance increased by 28.2% (from 86.0 +/- 58.3 to 109.2 +/- 74.8 ml.min-1 x kg liver-1; p < 0.04). No significant differences were observed in enzyme release, biliary flow (n = 5) and oxygen consumption. Histological examinations demonstrated sinusoidal dilatations in six of eight cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Tunnelized double femoral catheters. A technique for vascular access in hemodialysis].

OBJECTIVES: Temporary vascular access for haemodialysis is an everyday problem in a dialysis unit. We used the double catheter method developed for the internal jugular vein to catheterize the femoral vein in patients in which the jugular route could not be used. METHODS: A double catheter was inserted via percutaneous, bedside, punction into the femoral vein in 12 patients under local anaesthesia. The exit point was located near the middle of the thigh. RESULTS: Mean implantation time was 45 minutes. The inferior vena cava was the ideal site for the distal tip of the catheters. Mean duration of utilisation was 41 days (range 6-118) and allowed a mean of 28 haemodialysis sessions (range 4-49). Echo-Doppler examinations after withdrawal did not reveal any thrombosis of the femoral, iliac or vena cava. CONCLUSIONS: When the jugular route is difficult or contraindicated, double femoral catheterism is a useful alternative vascular access for haemodialysis.

Acute Kidney Injury↗

Acyclovir in preventing cytomegalovirus infection in kidney transplant recipients: a case-controlled study.

High dose oral acyclovir has been reported to be effective in preventing both cytomegalovirus (CMV) infection and disease in renal transplant recipients. We conducted a case-controlled study in which 42 cadaveric kidney transplant recipients were prophylactically treated with high dose oral acyclovir for 3 months and compared to historical controls matched for donor/recipient CMV serological status, age, sex, and immunosuppressive therapy. Before transplantation, study group patients received acyclovir intravenously (500 mg/m2 over 1 hour) which was subsequently given orally (basal dose--800 mg four times daily) from day 2 post-transplantation according to renal function. All patients received 14-day induction immunosuppressive therapy with either a polyclonal or a monoclonal antibody together with low dose steroids and azathioprine, cyclosporin being introduced at day 10 post-transplantation. Blood viral cultures as well as CMV antibody titers were performed in study group and control patients in the same laboratory, before transplantation, weekly until 3 months and then monthly until 6 months. CMV infection was defined as a positive blood or bronchoalveolar lavage viral culture or presence of CMV IgM or CMV IgG in a previously seronegative patient. Diagnosis of CMV disease also required the presence of at least one concomitant febrile illness, with or without other clinical symptoms, not attributable to another pathogen. All patients were followed for 3 months. Incidence of both CMV infection and disease was compared in the two groups using the log-rank test. With regard to CMV infection, we found significantly less CMV infection in CMV seropositive patients (regardless of donor CMV serological status) in the study group compared to historical controls (P = 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Acyclovir↗

Choledocho-ureteral anastomosis in the rat. A new experimental model of long-term, total, internal bile diversion.

Choledocho-ureteral anastomosis is a new experimental model of total bile diversion in the rat. The anastomosis is carried out using a polyethylene tutor drain and requires neither an external drain nor restraint of the animal. After 14 days of diversion, bile flow fell by 53% and there were no biological signs of cholestasis. The rats survived for up to 2 months. Choledocho-ureteral anastomosis is a reliable and simple experimental model which can be used to study the effects of prolonged interruption of enterohepatic bile-acid circulation.

Anastomosis, Surgical↗

Immunogenicity of rat hepatocytes in vivo: effect of cholestasis-induced changes in major histocompatibility complex expression.

Hepatocytes normally express few major histocompatibility complex (MHC) class I and no MHC class II molecules, a phenomenon which could explain their low immunogenicity. However, in pathological situations, such as allograft rejection and cholestasis, hepatocytes strongly express MHC class I molecules and their immunogenicity could be different. The aim of this study was to assess the role of MHC expression on the immunogenicity of hepatocytes in vivo. Hepatocytes were obtained from normal and cholestatic DA rats by whole-liver perfusion with EDTA. Cholestasis was induced by ligation-section of the common bile duct. MHC expression on hepatocytes was assessed by cytofluorimetry after labelling with monoclonal antibodies against MHC class I and class II antigens. The percentage of hepatocytes expressing MHC class I was 9.8 +/- 2.2% in normal rats and 77.2 +/- 3.3% in cholestatic rats (P = 2 x 10(-4)); MHC class II expression was present on 1 +/- 0.5% of normal hepatocytes and 0.4% +/- 0.1% of cholestatic hepatocytes (P > 0.05). Lewis rats received a DA or Wistar-Furth heart allograft 7 days after intravenous injection of 2 x 10(7) hepatocytes from normal or cholestatic DA rats. The DA heart allograft was rejected in 6.3 +/- 0.4 days in Lewis controls, 8.8 +/- 1.1 days (N.S.) in Lewis recipients that received normal DA hepatocytes and 17.6 +/- 3.0 days (P = 2 x 10(-4)) in Lewis recipients that received hepatocytes from cholestatic DA rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Augmented portal flow in the isolated perfused cirrhotic rat liver: a haemodynamic and morphological study.

1. Isolated perfused cirrhotic rat livers were used to study the effects of an increase in portal perfusion pressure and portal flow on the microcirculation and viability of the hepatocytes. Cirrhosis was induced by CCl4, and Krebs-Ringer bicarbonate buffer solution was used as the perfusate. Portal perfusion pressures were increased incrementally between 25 and 45 cm H2O. The viability of the livers was assessed and histological studies were performed under light and electron microscopy. 2. An increase in portal perfusion pressure induced an increase in hepatic flow in all the experiments (P < 0.05). Hepatic flow was 2.52 ml min-1g-1 of liver (SD 0.67; n = 5) at basal pressure compared with 4.19 ml min-1g-1 of liver (SD 0.93; n = 5) and 5.91 ml min-1g-1 of liver (SD 0.63; n = 5) when pressures were raised to 25 and 45 cmH2O, respectively. Portal perfusion pressure and hepatic flow were correlated (r = 0.908; P < 0.001; n = 30). 3. Production of the enzyme alanine aminotransferase (EC 2.6.1.2) increased significantly from 5.69i.u. ml-1min g-1 of liver (SD 3.62; n = 5) to 23.53i.u. ml-1min g-1 of liver (SD 16.7; n = 5) when the perfusion pressure was raised from baseline to 30 cmH2O. In all the cases the porto-caval gradient of enzyme production was within the normal range. No correlation existed between the release of enzyme and portal perfusion pressures.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Liver disease from surreptitious administration of urethane.

We report subacute necrosis, peliosis hepatis, venoocclusive disease and hepatic angiosarcoma after long-term administration of urethane. We take this to be the 12th case of urethane-induced hepatitis and the first associated with vascular liver tumor.

Chronic Disease↗

Endothelin-1 secretion by human gallbladder epithelial cells in primary culture.

BACKGROUND: The three isoforms of endothelin (ET), ET-1, ET-2, and ET-3 are potent contractile agonists for smooth muscle in a wide variety of tissues including the gallbladder. There is increasing evidence that endothelin acts in a paracrine fashion, however, its cell source in the gallbladder is unclear. EXPERIMENTAL DESIGN: To examine the production of ET by gallbladder and bile duct epithelium. RESULTS: We show that human gallbladder epithelial cells in primary culture secrete endothelin. ET release was time-dependent, and intracellular ET was negligible, indicating de novo synthesis. Secretion was increased by physiologic concentrations of cholecystokinin. Epithelial cells lining hepatic cysts in primary culture also released ET, suggesting that the intrahepatic, as well as the extrahepatic biliary epithelium is a source of this cytokine. High performance liquid chromatography separation of the conditioned medium from both cell types showed a single peak corresponding to that of ET-1. In vivo, ET-1 was present in hepatic cyst fluid, but was not detectable in gallbladder or choledochal bile. On tissue sections, both intrahepatic and extrahepatic bile duct epithelial cells were labeled with an anti-"big" ET-1 polyclonal antibody. CONCLUSIONS: These results suggest that ET-1 is locally produced in the biliary tract and by a paracrine route, could play a role in choledochal motility and gallbladder contraction.

Bile Ducts↗