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Biomedical subjects

Y Panis

Publications and source records attributed to Y Panis.

At least 127 records · Page 7Linked to original sources

[Treatment of experimental liver tumors by in vivo suicide gene transfer in rats].

We investigated whether the transduction of a suicide gene might induce the elimination of malignant solid tumours. BDIX male rats were given an intra-hepatic injection of a mixture containing DHDK12 tumor cells and xenogeneic fibroblasts. The latter were producing either the herpes simplex virus type 1 thymidine kinase HSV1-TK- or nls-lac Z(control)-expressing recombinant retroviral particles. 5 days later, a time at which the tumor is macroscopic, all the rats were treated with ganciclovir, a nucleoside analog that is metabolized by HSV1-TK into a toxic compound. After 5 days of treatment, a dramatic reduction in tumour volume was noted in the HSV1-TK group. These results delineate a new therapeutical strategy for the treatment of disseminated liver metastases or of a large variety of solid malignant tumours.

Animals↗

[Surgical treatment of toxic megacolon complicating pseudomembranous colitis. Apropos of a case, review of the literature].

Toxic megacolon complicating pseudomembranous colitis has been rarely observed. Only 36 cases have been previously reported. We present herein a new case report in which pseudomembranous colitis was secondary to prophylactic antibiotherapy with pefloxacin for hip prosthesis. Despite specific oral treatment (against Clostridium difficile) by vancomycin, toxic megacolon required urgent subtotal colectomy with ileostomy and sigmoidostomy. Postoperative course was uneventful. Analysis of the reported cases demonstrates the high overall mortality of the series (32%); the procedure of choice seems to be subtotal colectomy, which removes the septic focus, with a 12% operative mortality rate.

Aged↗

[Liver transplantation without clamping the vena cava inferior].

An original technique of orthotopic liver transplantation with preservation of the recipient's entire inferior vena cava and side-to-side caval anastomosis is described. The procedure was used in 21 consecutive patients. It has permitted to avoid vena cava occlusion and the need for venous bypass. No consequences on caval flow were observed during the anhepatic phase. Such technique avoids retrocaval dissection and requires only one caval anastomosis, reducing the duration of the anhepatic phase.

Acute Disease↗

Polymorphonuclear count in ascitic fluid after laparotomy in cirrhotic patients.

In order to establish whether an ascitic polymorphonuclear count greater than 250/mm3 remains a diagnostic criterion for postoperative bacterial peritonitis, a prospective study of 16 patients with cirrhosis and ascites undergoing hepatectomy (n = 4), portocaval shunt (n = 5) and biliary and digestive surgery (n = 7) was carried out. Sixty-four consecutive specimens of ascitic fluid were obtained through abdominal one-way suction tubes left in situ. In 17 (26%) specimens, ascitic fluid was blood stained and the polymorphonuclear count was unreliable; none of these specimens demonstrated positive ascitic fluid culture. In the remaining 47 specimens the polymorphonuclear count ranged from 5 to 5,920/mm3. Positive ascitic fluid culture was significantly higher in polymorphonuclear > or = 250/mm3 group (5/13: 38%) than in polymorphonuclear < 250/mm3 group (2/34: 6%) (p < 0.02). These results suggest that, as in non-operated cirrhotic patients: (a) polymorphonuclear count should be taken in account in the diagnosis of postoperative bacterial peritonitis; (b) polymorphonuclear count greater than 250/mm3 is a good criterion for the diagnosis of bacterial postoperative peritonitis.

Ascitic Fluid↗

A new technique of side to side caval anastomosis during orthotopic hepatic transplantation without inferior vena caval occlusion.

An original technique of OLT with preservation of the entire IVC of the recipient and side to side caval anastomosis is described. The procedure has permitted the avoidance of retrocaval dissection and temporary vena caval occlusion. The caval outflow was respected during the anhepatic phase. The technique, requiring only one caval anastomosis, has reduced the duration of the anhepatic phase and the need for venous bypass.

Anastomosis, Surgical↗

Experimental model of colon cancer: recurrences after surgery alone or associated with intraperitoneal 5-fluorouracil chemotherapy.

The liver is the most frequent site of metastases in colon cancer. No good animal model has been available to help improve the treatment of liver metastases or their prevention after resection of a primary colon cancer. The aim of this study was to develop a model of colon cancer induced by azoxymethane in the rat and to study the outcome after surgical resection alone or in association with intraperitoneal chemotherapy (5-fluorouracil (5-FU). Three hundred male Wistar rats received subcutaneous azoxymethane (10 mg/kg body weight/week) for 12 weeks. Eighty-three rats with isolated colon cancer underwent total colectomy; 40 of these rats with no metastases were randomized into two groups: surgery alone or surgery plus 5-FU (5 mg/kg body weight/day) for 5 days after surgery. Thirty rats were able to be evaluated. At autopsy, peritoneal carcinomatosis and liver metastases were more frequent in the control group than after adjuvant treatment with 5-FU (27.7 percent vs. 0, P less than 0.05; and 22.2 percent vs. 0, P less than 0.05, respectively). The rates of peritoneal and hepatic recurrence after resection of the primary cancer indicate that the model mimics the natural history of human colon cancer. In this model, 5-FU reduced the rate of peritoneal carcinomatosis and liver metastases but did not influence survival.

Adenocarcinoma↗

Intrahepatic recurrence after resection of hepatocellular carcinoma complicating cirrhosis.

To determine whether a careful evaluation of tumor extension by preoperative computed tomography scan after intra-arterial injection of ultrafluid lipiodol and by intraoperative ultrasound examination reduced the recurrence rate of hepatocellular carcinoma after resection, a series of 47 cirrhotic patients with a single tumor operated on from 1984 was studied. Alphafetoprotein level was less than 100 ng/mL in 26 patients (55%), size of the tumor was less than 5 cm in 28 patients (59%), and capsule was present in 30 patients (63%). The resection was performed with free margin measuring 1 cm or more. The overall cumulative survival rates at 3 and 5 years were 35% and 17%, respectively. Intrahepatic recurrence was observed in 28 patients (60%), located less than 2 cm from the resection margin in only four patients. The cumulative intrahepatic recurrence rate at 3 years was 81% and was significantly higher in patients with tumor greater than or equal to 5 cm and in patients with preoperative alphafetoprotein level of greater than or equal to 100 ng/mL. In this series the cumulative intrahepatic recurrence rate at 5 years was 100%. This high recurrence rate after resection, even with careful evaluation of tumor extension, indicates that liver transplantation might be envisaged for the treatment of cirrhotic patients with resectable hepatocellular carcinoma.

Adult↗

["Ex situ-in vivo" surgery of the liver: a new technique in liver surgery. Principles and preliminary results].

Major liver resections with complex vascular reconstruction require ischemia lasting from 2 h 30 to 5 h thus exceeding hepatic tolerance to warm ischemia. We describe a new technique of "ex situ-in vivo" liver surgery with prolonged ischemia with an intact hepatic pedicle. The surgical procedure encompasses complete mobilization of the liver and inferior vena cava, inferior mesenteric and femoral to axillary vein bypass, complete vascular exclusion of the liver, cold perfusion (U. W. solution), section of the hepatic veins allowing exteriorization of the liver ("ex situ") which remains connected by the hepatic pedicle ("in vivo"). The liver is placed on a heat exchanger at 4 degrees C. This procedure was performed in three patients: one each with hepatocellular carcinoma, huge metastasis of colorectal carcinoma and a "diffuse" hemangioma. Duration of ischemia was 225, 205, and 230 min respectively. The postoperative course was uneventful in all 3 cases and patients are alive at 15, 12, and 6 months. As it improves resecability rate of liver tumors and provides radical margins of resection, this procedure may be a beneficial alternative to liver transplantation for which poor results in cancer therapy with a high rate of recurrence are mainly due to immunosuppression.

Carcinoma, Hepatocellular↗

[Experimental models for hepatic metastases from colorectal tumors].

Over recent years, the interest in the development of experimental models of colorectal liver metastases has increased due to the need for new adjuvant therapies to improve the treatment of both colorectal cancer and liver metastases. The induction of colon cancer by carcinogens in the rat with spontaneous liver metastases fairly closely mimicks the natural history of colon cancer but a low yield of both colonic cancer (less than 50%) and liver metastases (approx. 25%) is obtained after 6 months of latency. Direct intraportal injection of cells derived from a colon carcinoma cell line is the experimental model most often used. Although it bypasses the natural history of cancer this simple model produces up to 100% of liver metastases 6 weeks after injection of cells. These two models have been used for several studies of liver metastases concerning their morphology, their modulating factors and their vascularisation. They have been used to test new adjuvant therapies for colorectal cancer.

Animals↗

Experimental colorectal liver metastases. Influence of sex, immunological status and liver regeneration.

The liver is the most frequent site of metastases from colon cancer. To improve our knowledge of liver metastases and to develop new adjuvant therapies, a good animal model is necessary. The aims of this study were to obtain a model of liver metastases with intraportal injection of colon adrenocarcinoma cell aggregates (DHDK12 cell line) and to study the effect of various factors, i.e., sex, liver regeneration and immunosuppression, on the development of liver metastasis. Cell aggregates were injected into the portal vein of 59 syngenic male and female BD IX rats following randomization into three groups. Group 1, (control 12 males and 10 females) received only cell aggregates; group 2 (12 males and 10 females) underwent a 70% hepatectomy before cell injection; group 3 (15 males and 10 females) received cyclosporin A injections at a dose of 10 mg/kg per day for 28 days following cell injection. Autopsy was performed at 10 weeks. Liver metastases were more frequent in the male rats in group 3 than in those in group 1 (80% vs. 30%, p less than 0.04). The rate of liver metastases in females was not increased by immunosuppression (22.2% vs. 12.5%, N.S.). Liver resection (group 2) did not significantly modify the incidence of liver metastasis. No female had liver metastases in this group. This relatively simple model rapidly produces liver metastasis with a high yield, but only in male rats. Besides sexual factors, immunosuppression also increased the rate of experimental liver metastasis, while liver regeneration failed to do so.

Adenocarcinoma↗

[Hepatocellular carcinoma arising in the normal liver. A clinical study and long-term prognosis after surgical resection in 12 patients].

Hepatocellular carcinoma mainly affects patients with cirrhosis or with various degrees of fibrosis. From 1979 to 1990, among 87 patients who underwent hepatic resection for non fibrolamellar hepatocellular carcinoma, 12 (14%) had a non fibrolamellar hepatocellular carcinoma developed in a normal liver. There were 8 men and 4 women, aged 29 to 74 years. In 7 patients (58%) hepatocellular carcinoma was associated with clinical manifestations. Serum hepatitis B surface antigen were absent in all patients. Serum alphafetoprotein level was less than 100 ng/ml in 10 (83%), size of the tumor was greater than or equal to 5 cm in 10 (83%) and capsule was present in 10 (83%). Resections included removal of 2 segments or more in 11 (91%). One patient died postoperatively. Actuarial survival rate at 3 and 5 years were respectively 57% and 38%. Intra or extrahepatic recurrence was recognized in 8 (67%), 2 patients were alive respectively 28 and 16 months after treatment of their intrahepatic recurrence (resection in one and intraarterial embolisation in one). In conclusion, our results suggest that aggressive surgical efforts are justified in non fibrolamellar hepatocellular carcinoma arising in normal liver.

Actuarial Analysis↗

[Rectal resection with colo-anal anastomosis for ergotamine-induced rectal stenosis].

Anorectal ulcers due to ergotamine suppositories are extremely rare. We report the first case of rectal stenosis following regular abuse of ergotamine suppositories which required rectal resection and coloanal anastomosis, despite stopping the intoxication 1 year previously. The rectal eversion during the perineal procedure allowed a low anastomosis to be performed, on the dentate line. One year later, the functional result was considered to be good, demonstrating the place of coloanal anastomosis in benign rectal pathology.

Adult↗

The isolated perfused rat spleen. An original method for studying the function of hepatocytes transplanted into the spleen.

The aim of this study was to assess directly the function of isolated hepatocytes 1 year after transplantation into the spleen, using an original model of isolated rat-spleen perfusion. Three specific liver functions, albumin synthesis, indocyanine-green clearance, and antipyrine oxidation, were studied. Five x 10(6) isolated hepatocytes were injected into the spleen of syngenic Wistar-Furth rats. One year later, splenectomy was performed, and the splenic pedicle was carefully isolated in order to allow a selective ex vivo perfusion for 3 hr. De novo albumin synthesis was studied by qualitatively using immunoelectrophoresis and autoradiography, and quantitatively using (35S)-methionine incorporation in albumin. De novo albumin synthesis was observed in spleens containing transplanted hepatocytes but not in controls (P less than 0.001); (35S)-methionine incorporation was significantly higher in spleens containing transplanted hepatocytes than in controls (132 +/- 67 cpm/spleen/hr vs. 14 +/- 6 cpm/spleen/hr, P less than 0.001). Antipyrine clearance was significantly higher in spleens with transplanted hepatocytes than in controls (67.4 +/- 4.9 microliters/min/g vs. 0.2 +/- 0.4 microliters/min/g, P less than 0.01). No statistically significant difference was observed with indocyanine-green clearance (4.2 +/- 6.0 microliters/min/g, vs. 5.2 +/- 5.1 microliters/min/g, P greater than 0.05); this was probably due to the absence of compartmentation between the sinusoid and biliary sectors in this model. In conclusion, using this original isolated rat-spleen perfusion model, it was directly observed that 1 year after transplantation, intrasplenic hepatocytes can perform two liver-specific functions, i.e., de novo albumin synthesis and antipyrine clearance.

Albumins↗