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Biomedical subjects

B Dupas

Publications and source records attributed to B Dupas.

At least 19 recordsLinked to original sources
PubMed2002

Extracorporeal photochemotherapy for secondary chronic progressive multiple sclerosis: a pilot study.

BACKGROUND/PURPOSE: Extracorporeal photochemotherapy (ECP) has been proposed for the treatment of various auto- and allo-immune reactions. However, a standard ECP regimen did not significantly alter the course of chronic progressive multiple sclerosis (MS). We tested whether an intensive ECP treatment can affect the course of secondary chronic progressive form of MS. METHODS: Five patients free of immunosuppression were included. Soluble 8-MOP was added ex vivo to a mononuclear cell suspension obtained in a cell separator. This cellular suspension was then irradiated using an UVA irradiator and re-infused into the patient. ECP was performed once a week for 6 weeks and then, depending on clinical evaluation, for a maximum of 6 months, with 2-year follow-up after treatment discontinuation. Scoring was performed with the Kurzke scale and EDSS by a single independent neurologist. RESULTS: One patient was excluded because of recurrent attacks at the very beginning of treatment. Four patients completed the study: one exhibited clinical improvement and three remained stable during the first 6 months of treatment. However, all experienced relapse or worsening of the disease after discontinuation of ECP treatment. CONCLUSION: Our intensive ECP treatment only transiently alters the course of the severe secondary chronic progressive form of MS, with rebound after treatment discontinuation.

Adult↗
PubMed2002

Percutaneous ethanol injection vs. resection in patients with small single hepatocellular carcinoma: a retrospective case-control study with cost analysis.

BACKGROUND: Percutaneous ethanol injection and hepatic resection are the most widely used curative therapeutic options for patients with compensated liver disease and small hepatocellular carcinoma. AIM: To compare percutaneous ethanol injection and hepatic resection in a selected group of consecutive French patients with a single hepatocellular carcinoma, smaller than or equal to 50 mm, in terms of survival, recurrence rate of malignancy and direct costs. METHODS: The analysis of two contemporary cohorts of Child-Pugh A or B patients with a single hepatocellular carcinoma of < or = 50 mm treated by percutaneous ethanol injection (n=55) or hepatic resection (n=50). RESULTS: Long-term survival was not significantly different between the two groups when the size of hepatocellular carcinoma was less than 30 mm. However, the survival of patients with hepatocellular carcinoma larger than 30 mm was higher after hepatic resection than after percutaneous ethanol injection (P=0.044). The cumulative direct costs were significantly higher in patients treated by hepatic resection than in those treated by percutaneous ethanol injection regardless of the tumour size. The calculated costs per month of survival in patients treated with percutaneous ethanol injection and hepatic resection were 999 vs. 3865 euros, respectively (P < 0.001). CONCLUSIONS: Percutaneous ethanol injection is more cost effective than hepatic resection in patients with a single hepatocellular carcinoma smaller than 30 mm. However, in patients with a larger tumour, long-term survival is higher after hepatic resection.

Aged↗
PubMed2002

Complications of radiofrequency coagulation of liver tumours.

BACKGROUND: Radiofrequency coagulation (RFC) is being promoted as a novel technique with a low morbidity rate in the treatment of liver tumours. The purpose of this study was to assess critically the complication rates of RFC in centres with both large and limited initial experience, and to establish causes and possible means of prevention and treatment. METHODS: This is an exhaustive review of the world literature (articles and abstracts) up to 31 December 2001; 82 independent reports of RFC of liver tumours were analysed. RESULTS: In total, 3670 patients were treated with percutaneous, laparoscopic or open RFC. The mortality rate was 0.5 per cent. Complications occurred in 8.9 per cent: abdominal bleeding in 1.6 per cent, abdominal infection in 1.1 per cent, biliary tract damage in 1.0 per cent, liver failure in 0.8 per cent, pulmonary complications in 0.8 per cent, dispersive pad skin burn in 0.6 per cent, hepatic vascular damage in 0.6 per cent, visceral damage in 0.5 per cent, cardiac complications in 0.4 per cent, myoglobinaemia or myoglobinuria in 0.2 per cent, renal failure in 0.1 per cent, tumour seeding in 0.2 per cent, coagulopathy in 0.2 per cent, and hormonal complications in 0.1 per cent. The complication rate was 7.2, 9.5, 9.9 and 31.8 per cent after a percutaneous, laparoscopic, simple open and combined open approach respectively. The mortality rate was 0.5, 0, 0 and 4.5 per cent respectively. CONCLUSION: The morbidity and mortality of RFC, while low, is higher than previously assumed. With adequate knowledge, many complications are preventable.

Carcinoma, Hepatocellular↗
PubMed2002

[Massive hemoperitoneum from rupture of an intra-peritoneal varix].

Rupture of an intra-abdominal varix in a patient with portal hypertension is a rare but severe cause of massive hemoperitoneum. The authors report the case of a patient with alcoholic cirrhosis that presented to the emergency department with hypovolemic shock. Imaging showed massive hemoperitoneum, severe portal hypertension and suggested the diagnosis of spontaneous rupture of an intra-abdominal varix, confirmed at laparotomy.

Abdomen↗
PubMed2001

Double common bile duct with ectopic drainage into the stomach. Case report and review of the literature.

A rare abnormal biliary tract consisting in a double common bile duct with an ectopic biliary tree draining into the stomach is described. This congenital anomaly, associated with lithiasis in the ectopic duct, was detected for the first time on MR-cholangiopancreatography. Only 23 cases of abnormal biliary drainage into the stomach have been reported in the literature. Embryogenesis and potential risks, such as lithiasis in the ectopic duct and the development of gastric carcinoma, are discussed.

Aged↗
PubMed2001

Laminar hook instrumentation in the cervical spine. An experimental study on the relation of hooks to the spinal cord.

Several anterior and posterior methods are today available for stabilization of the cervical spine. Factors such as level and degree of instability, method of decompression, bone quality, length of fixation and safety factors influence the choice of method for a particular patient. The use of laminar hooks in the cervical spine has been restricted by fear of cord compression with the potential of tetraplegia. The aim of the present study was to assess the safety and determine the anatomical relation between hooks inserted in the cervical spinal canal and the dura and spinal cord. Thirteen cadavers from seven women and six men with no evidence of cervical spine disorder were included. The mean age was 81.3 years (range 65-101 years). The cervical spine was instrumented with cervical Compact Cotrel Dubousset hooks and rods. The effect of the hook on the dura was studied by myelography in nine cadavers. The deformation of the dural sac was quantified by measurement of the maximal width of the indentation of the contrast column at each level. A CT myelography scan was obtained in three cadavers. The ratio between the distance of maximal hook intrusion into the spinal canal and the canal diameter in the direction of the hook was calculated. The relation between inserted hooks and the spinal cord and dura was documented in a fresh cadaver studied with CT myelography. A hemilaminectomy was performed at all levels in three cadavers with direct visual inspection and photography of the hook sites before and after excision of the dura. A dural deformation of 2 mm or less, as observed by myelography, was found at four out of 77 (5%) hook sites. The deformation was caused by a supralaminar hook at C3, C6 and C7 and by an infralaminar hook at C6. The mean hook intrusion in the spinal canal, as observed on CT, was 27% (range 8-43) of the canal diameter. On visual inspection, 14 out of 18 hooks were in contact with the dura. After removal of the dura, two out of the 18 hooks in the same cadaver were in contact with the spinal cord. However, no deformation of the cord was observed. To our knowledge this is the first study systematically documenting the relation between hooks and the spinal cord in cadavers. In 95% of the hooks no deformation of the dural sac was observed and there was no evidence of spinal cord deformation. From an anatomical point of view, laminar hook instrumentation can be considered a safe procedure. The study shows, however, that hooks inserted in the cervical spine have a close anatomical relationship with the neuraxis, and at stenotic levels the use of other techniques is therefore recommended.

Aged↗
PubMed2001

Immune-dependent distant bystander effect after adenovirus-mediated suicide gene transfer in a rat model of liver colorectal metastasis.

Gene transfer of the herpes simplex virus thymidine kinase (HSV-tk) gene sensitizes tumor cells to the toxic effect of ganciclovir (GCV). The toxic effect of GCV extends to nontransduced surrounding cells by a metabolic process known as the bystander effect. A distant bystander effect, which involves anatomically separated tumors, has been reported in vivo. Our aim was to evaluate and characterize such distant effect in a rat model of colorectal tumors implanted in the liver using adenovirus to carry the HSV-tk gene. Two colorectal tumors were implanted in two distinct liver lobes of the liver. One of the tumor was transduced with an adenoviral vector containing HSV-tk gene. The volumes of the tumors were monitored after GCV treatment. Implication of the immune system was studied histologically and after in vivo manipulations. After GCV administration, the nontransduced distant tumor regressed partially or completely in the experimental group. Immunohistochemical analysis revealed the presence of CD8+ lymphocytes in the distant lesion. HSV-tk/GCV-induced immune response against tumors was evidenced by an adoptive transfer assay (Winn assay) and the distant bystander effect was blunted after CD8+ lymphocytes depletion. However, the survival rates for treated animals were not improved. These findings demonstrate that an immune-mediated effective distant bystander effect can be obtained after limited adenoviral-mediated transfer of the HSV-tk gene.

Adenoviridae↗
PubMed2001

Contrast-enhanced MR imaging of experimental acute tubular necrosis.

PURPOSE: To demonstrate the involvement of the various renal structures in acute tubular necrosis (ATN). MATERIAL AND METHODS: In 15 rats, using a T1-/T2-weighted sequence, either gadodiamide alone, or gadodiamide in combination with sprodiamide (a susceptibility agent) were used to enhance the various anatomical substrates of the kidney. The results were compared to those of pathological verification. RESULTS: Experimentally induced ATN of the rat kidney causes profound changes in the medulla, leaving the cortex largely intact. The difference between the normal cortex and the partially necrotic outer medulla, on the one hand, and the papillary region, was significantly enhanced with the combination, whereas a larger region composed of the inner and outer medulla was enhanced after the gadolinium chelate alone. CONCLUSION: The results varied considerably between the two procedures; the double contrast demonstrated a clear difference between the inner and outer medulla, and the gadolinium chelate alone demonstrated a clear difference between the medulla and the cortex. These results demonstrated a clear difference in the compartmentalization between the inner and outer medullary regions, providing complementary information about the pathological condition of the kidney.

Animals↗
PubMed2001

Hepatocyte-mediated transport to the bile of AMI-HS, a particulate contrast agent.

RATIONALE AND OBJECTIVES: The elimination of hepatocyte-directed particulate contrast agents has not been studied in the same detail as particles eliminated mainly by the mononuclear phagocyte system. The aim of the present study was to elucidate the fate of these particles by a multidisciplinary approach. METHODS: After intravenous injection of AMI-HS particles directed to the hepatocytes, rats were killed and cytological studies, by both electron microscopy and histochemistry, and spectroscopic studies of the bile were performed. The data were compared with a dynamic magnetic resonance study of the heart and liver. RESULTS: The particles were rapidly cleared from the blood by Kupffer cells and hepatocytes and then found first in the vascular and later in the biliary pole of the hepatocytes. After 24 hours, a relaxometric characterization of the bile showed the presence of unchanged particles in the bile. CONCLUSIONS: These results show the capacity of the liver to excrete unchanged AMI-HS particles directly into the bile.

Animals↗
PubMed2000

Interruption of the inferior vena cava with azygos termination associated with congenital absence of portal vein.

The authors report an exceptional and well-documented case of interruption of the retrohepatic segment of the inferior vena cava with an "azygos continuation", combined with absence of the portal vein. The only known combination of congenital anomalies of the inferior vena cava and the portal vein was that of an "azygos continuation" and a preduodenal portal vein. The double interruption, portal and inferior caval, may be associated with a disturbance of preferential flows induced by the left umbilical thrust. According to hemodynamic theory, the left umbilical flow is the determining factor in organogenesis of the portal vein and the retrohepatic segment of the inferior vena cava.

Abnormalities, Multiple↗
PubMed2000

[MRI-cholangiopancreatography characteristics of cystic pancreatic tumors].

STUDY AIM: The purpose was to assess the value of MR cholangiopancreatography (MRCP) to evaluate the diagnosis and surgical resectability of pancreatic cystic tumors. PATIENTS AND METHODS: For MRCP, thick RARE and thin HASTE heavily T2-weighted sequences were performed with a 1.5 Tesla MR unit in 42 patients. Diffusion-weighted echo-planar sequences were performed in 16 patients. Surgical and histopathological correlation was obtained in 15 patients. RESULTS: MRCP detected all cystic lesions of the pancreas: 15 intraductal papillary mucinous tumors, 10 serous cystadenomas, 2 benign mucinous cystadenomas, 1 solid pseudopapillary tumor and 14 small cystic lesions (less than 2 cm) with no clinical signs. MRCP provided complete visualization of the pancreatic duct, showed excrescences within the dilated main or branch pancreatic ducts, identified microlacunar mixed and macrolacunar patterns, as well as septa, communications and stenosis, without contrast agent. MRCP did not characterize serous or mucinous cystic lesions. Specific diagnostic criteria of the various types of intraductal papillary mucinous tumors were noted (main duct, branch duct and combined types) and illustrated with the imaging findings necessary for accurate differential diagnosis. CONCLUSION: MRCP is a useful noninvasive and essential method in preoperative staging of cystic tumors of the pancreas; it is a reasonable alternative to endoscopic retrograde cholangiopancreatography and endosonography, as it provides the necessary information for treatment: surgical decision and/or follow-up.

Bile Ducts↗
PubMed2000

[Diaphragmatic excursion after inter-sternocleidomastoid block depending on the site of the injection].

OBJECTIVE: To evaluate the incidence of the hemidiaphragmatic paresis after inter Sterno-Cleido-Mastoid (inter-SCM) block. STUDY DESIGN: Prospective, comparative, single blind study. PATIENTS: 16 patients ASA I-II. METHODS: The diaphragmatic paresis was measured by a radiologist unaware of the technique used and operated side. It was determined by the diaphragmatic excursion (DE) on double-exposure chest radiography, obtained preoperatively and postoperatively (DE-pre, DE-post) for the ipsilateral and controlateral side of the inter-SCM block. All the patients were given 20 mL 0.5% bupivacaine plus 20 mL 2% lidocaine both with epinephrine. These anesthetics were injected via the stimuling needle or via the catheter after opacified radiological control of the catheter position. The patients were divided into 2 groups. Group 1: injection via the needle after eliciting flexion of fingers, or via a catheter into infraclavicular position; group 2: injection via the needle after eliciting contraction of deltoid, or elbow flexion, or via a supraclavicular catheter. RESULTS: All the patients had satisfactory block. The ipsilateral DE was decreased after injection of anesthetics in group 2 (P < 0.001) while it remained unchanged in group 1. CONCLUSION: The diaphragmatic paresis is avoidable with the inter-SCM block if and only if the anesthetic solution is injected via the needle after stimulating flexion of fingers or via a catheter into infraclavicular position.

Adult↗
PubMed2000

[Evaluation of a new sequence of magnetic resonance cholangio-pancreatography in thick cut and one shot acquisition].

OBJECTIVES: To assess the accuracy and reproducibility of a new magnetic resonance cholangiopancreatography sequence (MRCP), using long echo time and "single shot" acquisition (providing high-contrast thick slices: 20 mm or more), in the morphological analysis of the biliary tree and pancreatic ducts. METHODS: Fifty four patients with biliary and/or pancreatic disease were investigated with MRCP "single shot" thick slices. Biliary ducts were explored with MRCP "single shot", coronal and oblique coronal 20 mm thick slices on a 256 x 256 matrix. Natives pictures were reviewed by three independent radiologists, from three different institutions. MRCP results were compared with reference examinations in 54 cases (direct biligraphy methods: 54, CT scan: 11, endoscopic ultrasonography: 6, surgery: 6). RESULTS: For detection of bile duct dilatation, the agreement of MRCP "single shot" thick slices was more than 96% (Kappa > 0.92) and the inter-observer agreement was excellent (Kappa=0.92). For detection of biliary tree and/or pancreatic duct obstruction, MRCP "single shot" thick slice sensitivity was above 89% and specificity was 75%. The malignant nature of the lesions was determined with a sensitivity of 100% and a specificity of 92%. MRCP "single shot" thick slices could not differentiate pancreatic carcinomas from distal main bile duct cholangiocarcinomas. MRCP "single shot" thick slices did not detect small stones ( 3 mm) of the common bile duct. CONCLUSION: The excellent sensitivity, specificity and inter-observer agreement of MRCP "single shot" thick slices can be used to limit invasive imaging methods in the diagnosis of extrahepatic cholestasis.

Adult↗
PubMed1999

Electron microscopy study of intrahepatic ultrasmall superparamagnetic iron oxide kinetics in the rat. Relation with magnetic resonance imaging.

Ultrasmall superparamagnetic iron oxide (USPIO) contrast agents for use in magnetic resonance imaging (MRI) are currently undergoing clinical evaluation. However, the images observed and the kinetic profiles obtained differ from one agent to another. In this study, BD IX rats received an intravenous penis injection of the USPIO contrast agents AMI-HS and AMI-227. A cytologic study of the liver was performed, and the data obtained were compared with those of MRI. Images acquired in light microscopy, transmission electron microscopy, microanalysis and electron diffraction provided data on the cell categories involved in the processing of these contrast agents, the importance and modalities of each category relative to this processing, and the modalities of agent elimination. AMI-HS was rapidly removed from the bloodstream by Kupffer's cells and hepatocytes and then eliminated through bile ducts. AMI-227 remained much longer in the blood compartment since it was processed very slowly by endothelial and Kuppfer's cells in the near absence of hepatocytic participation and thus of elimination by the bile ducts. These results allowed us to base our interpretation of MRI sequences on cytologic observations.

Animals↗
PubMed1999

Gadolinium-enhanced MR imaging of normal renal transplants. An evaluation of a T1-weighted dynamic echo-planar sequence.

PURPOSE: To evaluate the potential usefulness of dynamic MR with echoplanar imaging (EPI) in assessing the renal function in patients with renal allografts. MATERIAL AND METHODS: Using a T1-weighted sequence, EPI was performed after injection of a Gd-chelate in 17 patients with normally functioning renal allografts. Time-intensity curves were plotted from the signal intensity (SI) measurements of the cortex and the medulla. RESULTS: The pattern of corticomedullar differentiation (CMD) observed after contrast enhancement was divided into four phases using the T1-EPI. After a rapid decrease in the SI of cortical structures, and a subsequent return to precontrast levels, a gradual fall in the SI of the medulla was observed. The average time between the two periods of signal loss was 60 s. CONCLUSION: This study illustrated the potential use of dynamic T1-EPI to demonstrate contrast-induced CMD in renal allografts.

Adult↗
PubMed1999

[MR cholangiopancreatography in choledochal cysts].

PURPOSE: To assess the value of MR cholangiopancreatography (MRCP) in the diagnosis and preoperative evaluation of choledochal cysts. MATERIAL AND METHODS: Five patients (aged between 6 days and 28 years) were investigated by MRCP, referred for ultrasonographic detection of a bile duct dilatation or a cystic structure, of antenatal diagnosis (1 case), for jaundice or abdominal pain (3 cases) or in late follow-up of a choledochal cyst surgery. Two endoscopic-ultrasonographic studies were performed. The five patients underwent surgery without preoperative biliary cholangiography. MRCP was performed using a HASTE sequence in frontal, oblique, axial planes (1,5 Tesla MR unit). RESULTS: MRCP allowed to confirm choledochal cyst, helps to specify the anatomical type (2 type I, 3 type II), detects choledocholithiasis (3 cases). Anatomic correlation was perfect. MRCP allowed to exclude gastrointestinal duplication. Anomalous junction of the pancreaticobiliary duct was found in one case. CONCLUSION: MRCP diagnoses choledochal cysts, specifies type, helps surgery and can avoid endoscopic retrograde cholangiography or endoscopic sonographic examinations especially for children. It may find an anomalous junction of the pancreaticobiliary duct.

Adolescent↗
PubMed1998

Interleukin-2/sodium butyrate treatment cures rats bearing liver tumors after acquired 5-fluorouracil resistance.

We studied the effect of immunotherapy using recombinant interleukin-2 (rIL-2) in combination with a differentiating agent, sodium butyrate (NaBut), on experimental 5-fluorouracil (5-FU)-resistant liver metastasis from colorectal cancer in rats. For this purpose, we used direct liver injection of 5-FU resistant cells, PRObRI, in syngeneic BDIX rats to establish liver tumors. The growth of liver metastasis was followed before and after NaBut/rIL-2 treatment by magnetic resonance imaging (MRI). The presence of liver tumors was checked by MRI 7 days after tumor cell injection. Evaluable rats were then assigned randomly to a control and an experimental group. The different treatments were started on day 10 and administered intraperitoneally (i.p.). Combined NaBut/rIL-2 treatment followed by MRI on days 56 and 91 was shown both to significantly reduce the growth of liver tumors and to prevent extrahepatic spread. In addition, NaBut/rIL-2 treatment induced a complete regression in 50% of the rats which remained free of disease.

Animals↗