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Bruno Heyd

Publications and source records attributed to Bruno Heyd.

16 recordsLinked to original sources
PubMed2006

Gene expression in human hepatocytes in suspension after isolation is similar to the liver of origin, is not affected by hepatocyte cold storage and cryopreservation, but is strongly changed after hepatocyte plating.

Isolated primary human hepatocytes are a well accepted system for evaluating pharmacological and toxicological effects in humans. However, questions remain regarding how culturing affects the liver-specific functions of the hepatocytes. In addition, cryopreservation could also potentially affect the differentiation state of the hepatocytes. The first aim of the present study was to compare gene expression in freshly isolated primary hepatocytes to that of the liver of origin and to evaluate the expression changes occurring after cryopreservation/thawing, both when maintained in suspension and after plating. The second aim of the present study was to evaluate gene expression in hepatocytes after cold storage of suspensions up to 24 h compared with freshly isolated hepatocytes in suspension. Our results show that the gene expression in freshly isolated human hepatocytes in suspension after isolation is similar to that of the liver of origin. Furthermore, gene expression in primary human hepatocytes in suspension is not affected by hepatocyte cold storage and cryopreservation. However, the gene expression is profoundly affected in monolayer cultures after plating. Specifically, gene expression changes were observed in cultured relative to suspensions of human hepatocytes that are involved in cellular processes such as phase I/II metabolism, basolateral and canalicular transport systems, fatty acid and lipid metabolism, apoptosis, and proteasomal protein recycling. An oxidative stress response may be partially involved in these changes in gene expression. Taken together, these results may aid in the interpretation of data collected from human hepatocyte experiments and suggest additional utility for cold storage and cryopreservation of hepatocytes.

Cell Separation↗
PubMed2006

N-acetylcysteine partially reverses oxidative stress and apoptosis exacerbated by Mg-deficiency culturing conditions in primary cultures of rat and human hepatocytes.

OBJECTIVE: The effects of magnesium (Mg) deficiency on the rate of oxidative stress and apoptosis in primary cultures of human hepatocytes were compared to cultured rat hepatocytes. The possible reversion by N-acetylcysteine (NAC) in Mg-deficient culturing conditions was evaluated. METHODS: Incubations were conducted for up to 72 h in media containing a deficient (0-0.4 mM) or a physiological (0.8 mM) Mg concentration, and in the presence or absence of NAC after 24 h of culture in these Mg concentration conditions. RESULTS: We obtained similar profiles in terms of apoptosis and oxidative stress in primary cultures of human hepatocytes, as compared to rat hepatocytes, i.e. a Mg concentration-dependent effect on the caspase-3 activity and GSH levels after 72 h of culture, caspase-3 activity being highest and GSH levels being lowest in Mg-free cultures. The addition of NAC to culture media after the first 24 h of culture increased GSH concentrations. This was accompanied in Mg-deficient cultures by a decrease in both the caspase-3 activity and the lipid peroxidation. However, when culturing hepatocytes with physiological Mg concentrations, an increase in both caspase-3 activity and lipid peroxidation was observed. CONCLUSIONS: Our results indicate that Mg deficiency exacerbates the rate of apoptosis in cultured hepatocytes, associated with an increase in oxidative stress, the sensitivity of human hepatocytes being equivalent to that of rat hepatocytes. They also indicate a dual role of NAC and/or GSH, i.e. protective for hepatocytes placed in a Mg-deficient environment, while deleterious for hepatocytes placed in a Mg-physiological environment.

Acetylcysteine↗
PubMed2006

Treatment of ulcerative colitis refractory to steroid therapy by oral microemulsion cyclosporine (Neoral).

BACKGROUND: Intravenous cyclosporine is active in 60% to 80% of patients with ulcerative colitis (UC) who failed to respond to intravenous corticosteroids. Several studies have suggested that cyclosporine in microemulsion form (Neoral) has some efficacy in this setting, but the optimal dose, blood level, time to response, and remission need to be better defined. The aim of this study was to evaluate the response to Neoral and its toxicity in active corticosteroid-refractory UC. METHODS: Between March 2002 and August 2005, 20 courses of Neoral [initial dose, 2.3 mg/kg (range, 1.8 to 2.8 mg/kg) every 12 hours] were prescribed in 19 consecutive patients for a UC attack that did not respond to intravenous methylprednisolone. All patients received prophylaxis against Pneumocystis carinii. RESULTS: Response was obtained in 17 of 20 attacks (85%) after 3.5 days (range, 1 to 7). Remission was obtained in 15 of 20 attacks (75%) after 13 days (range, 2 to 30 days). Four responders relapsed and underwent colectomy 21 to 900 days after the start of Neoral. Overall, 14 of 19 patients (74%) were colectomy free after a median follow-up of 8 months (range, 1 to 41 months). Cyclosporine blood levels were measured at fasting (C0) and 2 hours after Neoral administration (C2) in a subgroup of 10 responders. The results were 103 ng/mL (range, 32 to 240 ng/mL) for C0 and 761 ng/mL (183 to 1390 ng/mL) for C2. One severe bedridden patient with neonatal encephalopathy died. Main side effects observed were mild transient renal impairment (n = 2), hypertension (n = 1), cytomegalovirus infection (n = 2), and esophageal candidiasis (n = 1). CONCLUSIONS: In active corticosteroid-refractory UC, Neoral seems to have the same efficacy and toxicity as the intravenous form. Trough target cyclosporine blood levels should not exceed 100 ng/mL for C0 and 700 ng/mL for C2.

Administration, Oral↗
PubMed2005

Liver transplantation for cardiac failure in patients with hereditary hemorrhagic telangiectasia.

Liver involvement in hereditary hemorrhagic telangiectasia may lead to high-output cardiac failure. Few data have been reported on orthotopic liver transplantation (OLT) for these patients. In this paper, we describe two patients treated by OLT as a salvage procedure for cardiac failure, and we review literature on this subject. Our two patients resumed normal cardiac function after OLT. This procedure appears to be a promising therapy with good long-term results despite dissection difficulties encountered due to the collateral arterial network reorganization.

Angiography↗
PubMed2005

Serum and intraperitoneal pharmacokinetics of cisplatin within intraoperative intraperitoneal chemotherapy: influence of protein binding.

Intraperitoneal (i.p.) chemotherapy is a promising therapeutic method to improve the effectiveness of cisplatin in patients with ovarian cancer and peritoneum involvement. Intraperitoneal treatment can be intraoperatively performed just after a complete surgical resection of peritoneal tumor nodules. However, little is known regarding the pharmacokinetics of platinum during intraoperative i.p. chemotherapy (IIC). Serum and i.p. measurements of total and ultrafilterable platinum were performed to determined pharmacokinetic parameters in 11 consecutive patients who received a 2-h IIC with 50 mg/m cisplatin. Protein concentrations were determined in serum and peritoneal liquid at the same times. The cisplatin concentration required to kill OVCAR-3 human ovarian cancer cells and evaluation of cisplatin binding to proteins were determined in vitro. Platinum i.p. concentration decreased rapidly and quickly came under the cytotoxicity threshold (10 mg for 2 h). About 85% of i.p. and serum cisplatin was ultrafilterable during IIC. Platinum concentrations were closely related to protein concentrations. Due to the very low level of serum protein (almost 25 g/l), serum cisplatin binding during chemotherapy was very low (almost 25%), but increased with protein concentration recovery. These pharmacokinetic data show that a sufficient concentration to kill human ovarian cancer is not reached with a single i.p. bath containing 50 mg/m cisplatin for 2 h. A new protocol with a renewed bath and a higher cisplatin concentration is under investigation.

Aged↗
PubMed2005

Experimental models of acute and chronic liver failure in nude mice to study hepatocyte transplantation.

Although hepatocyte transplantation is a promising therapy for acute liver failure in human, there is still a lack of animal models suffering from hepatic injury in which the benefits of hepatocyte transplantation could be evaluated solely, without the bias caused by immunosuppression. As a consequence, the aim of the study was first to develop reproducible models of partial hepatectomy and of thioacetamide (TA)- or Jo2-induced acute liver failure in nude mice. Chronic liver disease was also investigated by repeated injections of sublethal doses of thioacetamide. Survival rates, routine histologic observations, alanin aminotransferase sera content, Ki67, and caspase 3 immunodetection were investigated both after 40% partial hepatectomy and after toxic-induced damages. Liver injuries were more severe and/or precocious in nude mice than in Balb/c mice for a given treatment with a maximum of acute injury obtained 24 h after single toxic injection, and were found to be transitory and reversible within 10 days. Toxics induced apoptosis followed by necrosis, confirming recent published data. Onset of fibrosis leading to reproducible chronic cirrhosis in nude mice correlated with increasing number of Ki67-positive cells, indicating that high levels of cell proliferation occurred. Chronic cirrhosis progressively reversed to fibrosis when the treatment ceased. Preliminary results demonstrated that engrafted xenogeneic hepatocytes could be detected in the host liver by anti-MHC class I immunohistochemistry. Fractions enriched in 2n or 4n hepatocytes by cell sorting using a flow cytometer were equivalent to the unpurified fraction in terms of engraftment in control nude mice or in nude mice subjected to PH. However, in mice suffering from liver injury 24 h after Jo2 or TA treatment, the engraftment of 2n hepatocytes was about twice that of an unpurified hepatocyte population or of a population enriched in 4n hepatocytes.

Animals↗
PubMed2004

Synthesis of 4-hydroxycoumarin and 2,4-quinolinediol derivatives and evaluation of their effects on the viability of HepG2 cells and human hepatocytes culture.

We report here the synthesis of aromatic coumarins and aromatic alpha-quinolones which were evaluated in vitro for their protective potentialities against tert-butyl hydroperoxide (t-BHP)-induced oxidative damage on human liver cell death, i.e., human hepatoma HepG2 cell line and human hepatocytes in primary culture. We found that the presence of a benzylidene at the 3-position or a heterocycle with N and S heteroatoms on the benzopyrone or quinolone system was essential for the protective effect of these compounds against t-BHP-induced decrease in viability of cells. We found also that a methoxy group on the aromatic ring systems decreased this potential. t-BHP-induced cytotoxicity in primary cultures of human hepatocytes could be therefore prevented by these compounds suggesting that they could display hepatoprotective effects in humans.

4-Hydroxycoumarins↗
PubMed2004

Tissue collection, transport and isolation procedures required to optimize human hepatocyte isolation from waste liver surgical resections. A multilaboratory study.

BACKGROUND: The European Center for Validation of Alternative Methods (ECVAM) has funded a prevalidation study in three laboratories (France, USA and UK) on the use of human hepatocyte cultures to predict cytochrome P-450 induction. AIMS AND METHODS: As first stage of this prevalidation study, the purpose of the present work was to set criteria for optimization and harmonization of hepatocyte isolation from human tissue among laboratories to establish a routine procedure. This was achieved by combining and/or comparing the data generated by the two independent European laboratories (France and UK). RESULTS: The results confirmed that surgical waste material is a valuable source for obtaining high quality hepatocytes under certain pre-, intra- and post-operative conditions: cell yield of viable hepatocytes was not significantly affected by age and sex of patients, nor indications for resection, steatosis or cholestasis. Cold ischeamia up to 5 hours did not influence viable cell yield allowing transport of material. CONCLUSION: The use of biopsy sizes between 50-100 g, cannulation with 2-4 cannulae, digestion with collagenase-containing digestion medium at a flow rate of 25 ml/cannula for 20 minutes, with cut surface being glued in order to reform Glisson's capsule, should optimize the total yield of viable human hepatocytes obtained per preparation of waste liver surgical resections.

Adult↗
PubMed2003

Effects of clofibric acid on mRNA expression profiles in primary cultures of rat, mouse and human hepatocytes.

The mRNA expression profile in control and clofibric acid (CLO)-treated mouse, rat, and human hepatocytes was analyzed using species-specific oligonucleotide DNA microarrays (Affymetrix). A statistical empirical Bayes procedure was applied in order to select the significantly differentially expressed genes. Treatment with the peroxisome proliferator CLO induced up-regulation of genes involved in peroxisome proliferation and in cell proliferation as well as down-regulation of genes involved in apoptosis in hepatocytes of rodent but not of human origin. CLO treatment induced up-regulation of microsomal cytochrome P450 4a genes in rodent hepatocytes and in two of six human hepatocyte cultures. In addition, genes encoding phenobarbital-inducible cytochrome P450s were also up-regulated by CLO in rodent and human hepatocyte cultures. Up-regulation of phenobarbital-inducible UDP-glucuronosyl-transferase genes by CLO was observed in both rat and human but not in mouse hepatocytes. CLO treatment induced up-regulation of L-fatty acid binding protein (L-FABP) gene in hepatocytes of both rodent and human origin. However, while genes of the cytosolic, microsomal, and mitochondrial pathways involved in fatty acid transport and metabolism were up-regulated by CLO in both rodent and human hepatocyte cultures, genes of the peroxisomal pathway of lipid metabolism were up-regulated in rodents only. An up-regulation of hepatocyte nuclear factor 1alpha (HNF1alpha) by CLO was observed only in human hepatocyte cultures, suggesting that this trans-activating factor may play a key role in the regulation of fatty acid metabolism in human liver as well as in the nonresponsiveness of human liver to CLO-induced regulation of cell proliferation and apoptosis.

Aged↗
PubMed2003

Indications and results of liver transplantation for Echinococcus alveolar infection: an overview.

BACKGROUND: Alveolar echinococcosis (AE) of the liver, caused by the larval stage of the fox tapeworm Echinococcus multilocularis, has the characteristics of a slow-growing liver cancer. It is one of the rare parasitic diseases for which a parasitolytic drug is not yet available, and AE is lethal in the absence of appropriate therapeutic management. Complete surgical resection of the parasite at an early stage of infection provides favourable prospects for cure, but, due to a long clinical latency, many cases are diagnosed at an advanced stage, so that partial liver resection can be performed in only 35% of patients. Benzimidazole (BZM) treatment is given in inoperable cases but these compounds are only parasitostatic, and lifelong therapy is required. During the past 20 years some centres have considered liver transplantation (LT) for the treatment of incurable AE. METHODS: Our review summarizes the results of this experience based on a series of 47 European patients who received transplants between 1985 and 2002, tries to specify the real place of LT for AE, and underlines the measures that could be undertaken in the future to improve the results. RESULTS: Five-year survival was 71%. Five-year survival without recurrence was 58%. Major technical difficulties related either to previous laparotomies or to the loco-regional involvement were observed. The nine early deaths concerned AE patients with a long past-history of symptomatic AE (iterative cholangitis, secondary biliary cirrhosis). Five late deaths were directly related to ongoing AE, located in the brain in three cases, a very rare AE location that was not investigated before LT in these patients. CONCLUSIONS: In general, the pre-LT screening for distant AE metastases appeared insufficient in this series. Heavy immunosuppressive schemes, absence or delayed re-introduction of BZM after LT have clearly played a role in this unfavourable course. This unique experience indicates that, despite major technical difficulties, LT for incurable AE is feasible and could be discussed in very symptomatic cases. Before LT, interventional radiology should be preferred to repeated laparotomies. Pre-LT and post-LT BZM treatment is mandatory. A careful evaluation of possible distant metastases should be done before the decision for LT is made. After LT, the possibility of an ongoing AE must be permanently kept in mind. This could be reduced by lightening the immunosuppressants, carefully following the specific circulating antibodies, and applying a systematic radiological evaluation, not only to the graft but also to the lungs and the brain.

Adolescent↗
PubMed2003

Experience of liver transplantation for incurable alveolar echinococcosis: a 45-case European collaborative report.

BACKGROUND: Alveolar echinococcosis (AE) of the liver is a rare and severe parasitic disease. It behaves like a slow-growing liver cancer, and liver transplantation (LT) has been proposed in advanced cases since 1985. The aim of this retrospective study was to collect all AE transplant cases in Europe, analyze the results, and specify the usefulness of LT for this unusual indication. METHODS: A questionnaire was sent to 83 LT centers from July 1996 to December 1999. RESULTS: Sixty-five centers responded: 45 AE patients (mean age, 45.8 years) underwent an LT procedure at 16 LT centers. The mean interval between diagnosis and LT was 5 years. One patient died during the hepatectomy phase. Five-year survival was 71%. Five-year survival without recurrence was 58%. The nine early deaths were mostly related to bacterial or fungal infections, or both, in patients in bad condition when LT was performed. Six patients had a graft AE reinfection. Five late deaths were related directly to ongoing AE. In the other cases, benzimidazole (BZM) therapy seemed to stabilize AE residues. CONCLUSIONS: This unique experience indicates that LT is feasible for life-threatening AE. Specific management is needed to optimize the results: earlier decision for LT in incurable symptomatic biliary AE, pre- and post-LT BZM therapy, meticulous pre-LT evaluation to identify extrahepatic extension, and an immunosuppressive regimen kept to a minimum.

Adolescent↗
PubMed2002

Feasibility of and interest in combined endoscopic ultrasonography and biliary drainage in unexplained acute biliopancreatic disorders.

Combined endoscopic ultrasonography and duodenal bile drainage for microscopic bile examination was prospectively evaluated in patients with unexplained acute biliopancreatic disorders defined as follows: isolated biliary-type pain (group 1), biliary-type pain and elevated transaminases (group 2), or acute pancreatitis (group 3). All patients had prior negative transabdominal ultrasonography. Endoscopic ultrasonography and bile drainage were combined under anesthesia during the same procedure. Combined endoscopic ultrasonography and bile drainage was feasible without any complication in the 48 patients studied. Biliary lithiasis was diagnosed in 20 patients (42%), 5 in group 1 (38%), 7 in group 2 (39%), and 8 in group 3 (47%). Endoscopic ultrasonography and microscopic bile examination were positive respectively in 17 (36%) and in 13 (27%) patients. In conclusion, combined endoscopic ultrasonography and bile drainage for microscopic bile examination is a simple procedure. Biliary lithiasis is diagnosed in a high proportion of patients with unexplained acute biliopancreatic disorders.

Acute Disease↗
PubMedDate not supplied

Esophageal stents as a salvage therapy for non-malignant iatrogenic esophageal perforations.

BACKGROUND: Esophageal non-malignant perforations are severe life-threatening conditions. The current treatment is either surgical or conservative. METHODS: We report a case series of 3 consecutive patients (1 female, 2 male; 34-68 years) treated with expandable covered stents for non-malignant iatrogenic esophageal perforations. OBSERVATIONS: In our series, 3 out of 3 patients sealed their perforations and resumed normal oral intake. Complications observed were 2 stent migrations, which occurred at 6 and 11 months after stent insertion, a stenosis due to acid reflux treated by another stent insertion above the first one. On the basis of the data available, it appears that esophageal stents was successful in 82% of the cases. The mortality and complication rates were of 7% and 32% respectively. The main complications observed were peptic stenosis above the stent and fistulas. CONCLUSION: These results are promising but need to be confirmed in large-scale prospective studies. Mediastinal drainage remains mandatory when sepsis is present.

Adult↗