Biomedical subjects
H Joyeux
Publications and source records attributed to H Joyeux.
[Coagulation disturbances after subtotal or total hepatectomy in the dog (author's transl)].
The authors relate 15 cases of blood coagulation disturbances among three groups of animals after 80%, 90% or total hepatectomy. Animals in group I, after 80% hepatectomy, were sacrified between the 10th and 30th postoperative days. Group II animals, with 90% hepatectomy, survived for periods ranging from 18 to 24 hours. In group III, after total hepatectomy, survival varied between 30 and 40 hours. The coagulation disturbances which were observed following 80% hepatectomy were spontaneously compatible with the survival of the animals. Following 90% and total hepatectomy the resulting disturbances were constantly severe enough to limit survival time. Supportive procoagulant therapy associated with sequential heparin administration seems justified by the insufficient biosynthesis of clotting factors and their unavoidable consumption as a result of localized then disseminated intravascular coagulation and secondary fibrinolysis.
Mediation by an androgen receptor of the stimulatory effect of testosterone on the growth of a fibrosarcoma in the rat.
We studied the effect of testosterone on the growth of a 20- methylcholanthrene-induced transplanted fibrosarcoma and assayed androgen receptors in this tumor. The effect of an antiandrogen in male rats and the comparative tumor growth in females confirmed the androgen sensitivity. A synthetic androgen that strongly binds to the androgen receptor was used to characterize the binding activity in nuclear extracts of tumor. Scatchard analysis showed that the dissociation constant of the hormone receptor complexes (Kd) was 26 +/- 2 nmol/l and the number of binding sites was about 95 +/- 12 fmol/mg of protein. The hormone-receptor complexes sedimented in the region of 3.7 S.
[Short bowel syndromes in adults. Prognostic factors. Evaluation and treatment. Retrospective study. Apropos of 80 cases].
Since 1981, a consensus is appeared in order to define and to precise the natural evolution of short bowel with a maximal remaining small bowel of 150 cm. The phenomenon of intestinal adaptation which are better known in animals than in humans, are on the dependence of luminal, hormonal and humoral factors (epidermal growth factor, polyamines). The knowledge of prognostical factors and the anatomical and functional evaluation of remaining small bowel allow to "measure" the improvement of digestive absorption and to decide the duration of nutritional support. An experience in 80 cases of short bowel syndrome is reported. A significant correlation exists between the duration of parenteral nutrition support and the length of the remaining gut (p < 0.001) and multifactorial analysis differentiates 3 groups of short bowel characterized by their length and parenteral support duration.
[Serum marker of the functional hepatic mass after extensive hepatectomy. The branched/aromatic amino acid ratio. Experimental and clinical studies].
During severe hepatic insufficiency, serum amino acid profile is modified with an increase of aromatic amino acids (AAA) (Tyrosine and Phenylalanine) and methionine concentrations and a decreased value of 3 branched chain amino acids (BCAA) (leucine, isoleucine and valine). These observations have been confirmed after hepatic surgery in experimental and clinical studies. In experimental models, after 10, 32, 68, 77 or 90% hepatectomy in Wistar rats, the BCAA/AAA ratio (R) is correlated with the extent of hepatectomy: r = 0.74, p < 0.001; with the post-operative interval time (8, 24, 32, 48, 168 or 240 hours): r = 0.60, p < 0.001 and with the liver weight when animals are sacrificed: r = 0.64, p < 0.001. In clinical studies, 26 patients have undergone 60 to 80% hepatectomy for primary or secondary tumors of the liver and R is determined on the immediate post-operative day and every day during the first post-operative week. Liver regeneration is followed by single photon emission computerized tomoscintigraphy on days 0, 7 and 30 with assessment of hepatic growth index (HGI) estimated by the ratio: liver mass on day 7 or 30/remnant liver mass on day 0. On post-operative day 7, R is 1.61 +/- 0.3 (normal: 3.5 +/- 0.51). Mean liver volume is 60 +/- 11% and HGI is 1.9 +/- 0.3. On this day, a correlation is found between R and HGI (r = 0.76). On post-operative day 30, HGI is 2.34 +/- 0.50, mean liver volume is 89.6 +/- 0.9% and R is 2.02 +/- 0.65.(ABSTRACT TRUNCATED AT 250 WORDS)
Evidence for CYP3A-mediated N-deethylation of amiodarone in human liver microsomal fractions.
Metabolism of amiodarone to its N-deethylated derivative was investigated on a bank of human hepatic microsomal fractions, two of them lacking the CYP2D6 isozyme. Michaelis-Menten constants for amiodarone N-deethylation were 0.33 +/- 0.11 microM and 2.38 +/- 0.74 nmol/min/mg for KM and Vmax. The specific involvement of CYP3A gene subfamily in amiodarone N-deethylation was provided by the following observations: 1) metabolism of amiodarone is inhibited in a concentration-dependent manner by ketoconazole, a specific CYP3A inhibitor, and by nifedipine, a specific substrate for CYP3A gene subfamily, with IC50 of 0.3 and 25 microM, respectively; 2) nifedipine competitively inhibits amiodarone metabolism with a Ki of 38 microM; 3) amiodarone N-deethylation is increased following incubation with hepatic microsomal fractions prepared from CYP3A-inducers such as rifampycin and triacetyloleandomycin, but also following the in vitro disruption of the "cytochrome P-450-Fe-(II)-triacetyloleandomycin nitroso derivative" complex; 4) antibodies raised against either rabbit or baboon monkey CYP3A gene subfamily inhibit amiodarone N-deethylation; and 5) microsomal fractions that specifically express CYP3A4 biotransform amiodarone to its N-deethylated derivative. These studies indicate that CYP3A isozyme(s) mainly metabolize amiodarone to its N-deethylated derivative in human hepatic microsomal fractions.
[Proceedings: New technic of parenteral feeding].
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Long term ambulatory parenteral hyperalimentation (L. T. A. P. H.) in Gastroenterology [proceedings].
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[Liver tumors around the vena cava. Strategy for surgical approach of segments I and IX].
The technical problems raised by the delicate surgery of tumours of the liver developing around the vena cava, with and without invasion of segments I and IX was studied on the basis of 7 cases reports. The intra- or extra-hepatic pedicule route, the denudation of the entire retrohepatic vena cava, and the clamping needed for exsanguinous surgery are presented together with future perspectives including 3-D liver imaging, stimulation of liver regeneration potential and ex-vivo techniques are discussed with the aim of more and more carcinological liver surgery.
[Therapeutic strategy in 46 cases of radiation injury of the intestine].
Our expérience in the treatment of 46 cases with radiation enteritis (RE) permitted to summarize 5 key points in the Surgical Strategy: laparotomy incision, enterolysis technique, small bowel and colon preservation, anastomosis technic and parenteral nutritional support. Surgery is imposed most of the time in digestive and nutritional Insufficiencies due to radiation enteritis. 46 patients aged to 33-81 years (mean age = 59) were included for possible surgery. The first clinical digestive symptoms were occlusion (n = 39) and/or digestive fistula (n = 7) and/or perforation (n = 3). These abnormalities were often associated with severe malnutrition (weight loss > or = 20% of usual weight) inducing surgery preparation with pre-operative parenteral nutrition (8 to 350 days). 3 patients were not operated because of general problems and lived 1 to 7 months after the beginning of parenteral nutrition. For operated patients (n = 43), 12 underwent 2 operations (resection and/or enteral liberation) and one patient underwent 4 surgical interventions because of digestive fistula. In 35 cases, small bowel resection was performed leaving 135.4 +/- 62.6 cm of intestine (0 to 225 cm of jejunum and/or ileum) and in 13 cases, complete enterolysis was achieved. All the patients received a post-operative parenteral nutrition during 1 to 23 months (median = 6.2 +/- 5.3 months). 31 patients received home parenteral nutrition during the pre and/or post-operative phase for a median duration of 6.3 +/- 3.2 months (range: 1-23 months). 4 patients died during the immediate post-operative phase and among them, 3 died after the second surgery. 12 deaths were observed due to the primary cancer and 6 due to the evolution of radiation lesions. Median survival of patients without cancer evolution reach 180 months with a 5-year survival rate of 94% (Kaplan-Meier method). In patients with radiation enteritis, the pre and post-operative nutritional support associated with radical surgery allows to obtain prolonged survival in non cancer patients.
[Therapeutic strategy for large cervical, mediastinal metastatic mature teratomas and large retro- and intraperitoneal lesions].
A 27 years old man was treated after surgery and classic chemotherapy for a right testicular teratoma (stage IV). Two months after the end of chemotherapy the patient developed "a Growing Teratoma Syndrome" with left subclavian and mediastinal nodes enlargement and bulky abdominal cystic masses with vena cava compression, collateral circulation and oedema of inferior members. Four debulking surgical approaches: cervical, thoracic and abdominal were performed and permitted complete functional recovery.
[Application of three-dimensional computer graphics in oncology].
Accurate 3D tumoral volume evaluation is now possible through the combined use and progress of computer graphics technics (3D reconstruction and visualization) and medical imagery (helicoidal TDM scanner). Specific organ and pathology oriented softwares can help answer rapidly to problems posed by oncologic praticians. A new decision support for diagnosis, therapy and follow-up is emerging. First results in liver tumors and hepatic regeneration macroscopic biometrics are presented. Tumoral or organ volumic index will be usable in the follow-up. TNM staging, external conformal radiotherapy for prostatic or brain tumors, drugs cytolytic effects evaluation will take great advantage of these technologies. 3D visualization and matching CT and MRI imagery can help computed assisted surgery.
[Intestinal rest. Technique. Indications. Results (author's transl)].
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