In vivo retrovirus-mediated gene transfer into lamb liver.

TOPIC: Highly efficient retrovirus-mediated gene transfer into hepatocytes in vivo has been previously reported in the rat. Before considering human applications of these techniques in the treatment of inherited liver diseases, it was necessary to document its efficiency in a large animal model. Lamb was choosen because the liver was similar to human liver regarding size and anatomy. MATERIALS AND METHODS: To induce hepatocyte division which is necessary for infection with retroviral particles, animals were subjected to a left hepatectomy. Kinetics of liver regeneration were assessed on sequential liver biopsies after partial hepatectomy in order to provide an evaluation of the peak of maximal liver regeneration in a first animal group. Recombinant retroviruses encoding a reporter gene (E. coli beta galactosidase) were then perfused through the portal vein of the regenerating liver in a second animal group. RESULTS: The more intense liver regeneration occurred from one to 6 days after partial hepatectomy, with the highest thymidine kinase rate and MIB-1 antibody staining on the second day. The proportion of genetically modified lamb hepatocytes expressing the reporter gene was less than 1%, despite the use of higher titers of retroviral particles than those described in previous reports. CONCLUSION: The results obtained in rodent livers with this in vivo gene transfer methodology cannot currently be scaled up in a large ruminant model. The efficacy of vectors has to be tested in other large mammals before planning gene therapy trials for the treatment of inherited liver diseases

In vivo retroviral-mediated transfer of a marker-gene in ornithine transcarbamylase-deficient Spf(ash) mice.

Gene therapy is a new therapeutic approach for inherited metabolic hepatopathies. The authors studied the potential application of such a strategy to the correction of ornithine transcarbamylase (OTC) deficiency by in vivo protocol of retroviral-mediated gene transfer to the liver. A partial hepatectomy was followed (24 to 48 hours later) by asanguinous perfusion of the regenerating liver with beta-galactosidase (beta-gal) recombinant retrovirus. This protocol allowed beta-gal gene transfer in normal C57B6 mice liver with 60 +/- 52 positive cells per square centimeter. This proportion never exceeded 20 cells per square centimeter in OTC-deficient spf(ash) mice. The high mortality rate for spf(ash) mice was explained by an important sensitivity of those mice to the protein catabolism rather than by technical difficulties during intraportal perfusion. This first in vivo retroviral-mediated gene transfer study in animals with a life-threatening metabolic inherited hepatopathy showed that, despite efficiency of gene therapy in normal animal models, several experimental difficulties should be overcome before human application of this protocol is considered

The challenge of measuring quality of life in children with Hirschsprung's disease or anorectal malformation

PURPOSE: The aim of the present study was to assess, after adaptation to French, the only specific quality of life (QoL) instrument for children with Hirschsprung\u27s disease or anorectal malformation, the Hirschsprung\u27s disease/Anorectal Malformation Quality of Life questionnaire (HAQL), in order to get a standardized QoL evaluation instrument that could further be used to help health care improvement. METHODS: The study was conducted in three teaching hospitals, including the French reference center for anorectal and pelvic malformations. After adaptation to French, QoL questionnaires were sent to the children and proxies. The questionnaire was mailed to 280 families. Psychometrics properties of the questionnaires (validity and reliability) were analysed from 120 proxy and 96 child questionnaires. RESULTS: The HAQL with the original structure was not acceptable. Exploratory steps led to a clinically pertinent structure that had acceptable fit and good validity and reliability properties. The final structure pools physical symptoms (continence, discomfort) and psychosocial dimensions (general well-being, social and emotional functioning) of QoL. CONCLUSION: The final structure, despite the disadvantage of being a new structure, allows assessment of QoL in this population and has the advantage of being shorter and validated on the clinical postoperative questionnaire from the Krickenbeck international consensus

Learning Laparoscopic Skills: Observation or Practice?

OBJECTIVE: The aim of this study was to assess the respective roles of observation and direct practice in the retention of laparoscopic skills. MATERIALS AND METHODS: Eighteen fifth-year medical students were included in a two-session laparoscopic learning course. During the first session, each participant was given four tasks to complete from the "Basic skills" and "Essential tasks" modules of the Simbionix LAP Mentor™, and another four tasks for observation only. During the second session, each participant completed all eight tasks. Performance evaluation was assessed using the objective structured assessment of technical skills (OSATS) global rating scale and LAP Mentor metrics. RESULTS: The mean OSATS score during the first session (S1) was 16.7 ± 3.2. This increased by 34% during the second session (S2), reaching 21.8 ± 2.6 in the group of former observer students (S2O, P < .0001), and by 56% (25.1 ± 1.9) in the group of former practicing students (S2A, P < .0001). The analysis of LAP Mentor metrics showed that 14 of 28 parameters (50%) improved in the S2A group compared to S1, whereas only 25% of the parameters improved in the S2O group, the difference being significant (P = .048). In both groups, the more complex the task, the more the number of improved parameters decreased. CONCLUSIONS: Although simple observation of laparoscopic skills improved further performance, direct practice on the virtual reality trainer ensured more effective training. This work therefore advocates incorporating personal training on simulators into residents\u27 surgical curricula

Skills improvement after observation or direct practice of a simulated laparoscopic intervention

BACKGROUND: Laparoscopic skills are more and more often being learned on simulators. PURPOSE: To assess the respective roles of observation and direct practice in the retention of laparoscopic procedural skills. BASIC PROCEDURES: Twelve surgical residents were included in a two-session laparoscopic training course. During the first session (S1), one participant completed a cholecystectomy on the Simbionix LAPMentor™ and then observed his colleague carrying out a total hysterectomy and vice versa. During the second session (S2), each participant completed both interventions. Skills evaluation was assessed using the Objective Structured Assessment of Technical Skills (OSATS) global rating scale and LAPMentor™ metrics. MAIN FINDINGS: Mean OSATS score during the first session was 19.3±5.1, and increased by 37% in the group of former observer students (S2O, P=0.003), and by 54% in the group of former practising students (S2A, P=0.001). Self- and peer-grading results were concordant with the supervisor\u27s evaluation. Detailed analysis of LAPMentor™ metrics showed a trend toward more parameters being improved in group S2A as compared to group S2O on both interventions. The most significant improvements concerned the time of completion for the hysterectomy and the efficiency of cautery for the cholecystectomy. CONCLUSIONS: Observation of laparoscopic skills still allows for surgical improvement, but direct practice on a virtual reality trainer provides better results. Self- and peer-grading were concordant with the supervisor\u27s evaluation. This work may advocate the integration of both personal training on simulators and surgical observation into residents\u27 surgical curricula

Hereditary pancreatitis in children: surgical implications with special regard to genetic background.

PURPOSE: Hereditary pancreatitis (HP) is the primary etiology of chronic pancreatitis during childhood, progressing through recurrent episodes of acute pancreatitis and finally leading to pancreatic insufficiencies. Hereditary pancreatitis is because of mutations of the cationic trypsinogen (PRSS1) gene. Some other genes, such as SPINK1 or CFTR, have been associated with familial idiopathic chronic pancreatitis. The aim of our study was to clearly define diagnostic and therapeutic strategies for HP patients, through an analysis of our study group and a review of the literature. METHODS: All children admitted from 1995 to 2007 with a final diagnosis of hereditary pancreatitis were restrospectively included in the study. We analyzed all medical records with special attention given to cases involving genetic screening (PRSS1, SPINK1, and CFTR genes). RESULTS: Ten children were included. Eight had HP with PRSS1 mutation, 2 of them without a familial history of chronic pancreatitis. The 2 others patients had SPINK1 mutations. Three HP patients were operated on for acute complications of pancreatitis and are well with a mean follow-up of 5.5 years. No patient had pancreatic insufficiencies or weight loss. CONCLUSIONS: Hereditary pancreatitis is associated with severe pancreatitis, with a greater risk of developing pancreatic cancer. It must therefore be diagnosed correctly and treated to prevent its considerable complications

Tolerance and efficacy of preventive gastrostomy feeding in pediatric oncology

BackgroundMalnutrition in pediatric oncology remains underestimated, although having a negative impact on outcome. Enteral nutrition (EN) using percutaneous endoscopic gastrostomy (PEG) may prevent or reverse malnutrition consequences. We aimed to evaluate both efficacy and safety of early EN during tumors treatment in children. Procedures Medical records of pediatric patients having a PEG tube inserted between 1995 and 2009 were retrospectively reviewed. We compared type and incidence of complications in Group 1, including 74 patients suffering from cancer, and control Group 2, including 57 patients with neurological impairment. Efficacy of EN was evaluated through nutritional parameters [Z-scores weight for height (W/H) and height for age (H/A)], post-operative complications and relapse rates. Statistical significance was set for P < 0.05. Results PEG tolerance was similar in both groups, as shown by comparable complication rates (62% vs. 76%, NS). EN allowed improvement or stabilization of Z-score W/H in 76% of oncologic patients. The final height loss was lower (−0.5 vs. −1.2 SD of Z-scores H/A) when EN was started at the beginning of the oncologic treatment. In bone tumors, EN prevented weight loss during chemotherapy, and tended to lessen surgical complications, relapses and deaths. Conclusions Early gastrostomy feeding represents a relatively safe way to prevent malnutrition in children with cancer, and might play a role in bone tumors oncological outcome. Further prospective studies are needed to confirm these results and assess the impact of EN and PEG on quality of life

Factors influencing immune response after in vivo retrovirus-mediated gene transfer to the liver.

BACKGROUND: Highly efficient retrovirus-mediated gene transfer into hepatocytes in vivo triggers an immune response directed against transduced hepatocytes. This effect may be due either to spreading of retroviral vectors in the blood stream with subsequent infection of antigen presenting cells (APCs) or to cross-presentation of the transgene product present as a contaminant in the viral stock. In order to decrease immune response, we evaluated the effect of asanguineous perfusion of the liver as well as purification of the viral stock on long-term transduction of hepatocytes using the nls-lacZ marker gene. METHODS: Animals were divided in four groups. In group 1, the viral supernatant was perfused in the regenerating liver after complete vascular exclusion of the organ. In group 2, using the same strategy, animals received retroviral supernatant that was passed through a beta-galactosidase affinity column to reduce beta-galactosidase contamination. In two control groups (respectively groups 3 and 4) the corresponding viral supernatants were delivered via peripheral injection. RESULTS: In group 1, 23.1% of animals had no immune response 2 months after gene delivery vs. 33.4% in group 2, 4.3% in control group 3, and 0% in control group 4. Statistical analysis of the results demonstrated that only the difference between groups 2 and 3 was statistically significant. This indicated that both asanguineous perfusion together with passage through an affinity column were required to decrease significantly immune response. CONCLUSIONS: Our present results suggest that both supernatant contamination and viral spreading contribute to immune response after retrovirus-mediated gene delivery to the liver

Long-term Outcome of Hirschsprung Disease: Impact on Quality of Life and Social Condition at Adult Age

BACKGROUND: Hirschsprung disease is a rare congenital disease typically requiring surgical treatment during childhood. Quality of life and social condition at adult age can be impaired by disease-specific sequelae. OBJECTIVE: This study aimed to assess the quality of life and social outcome of adult patients operated on for Hirschsprung disease during childhood. DESIGN: Patients operated on for Hirschsprung disease during childhood were identified and specific questionnaires were sent to them. SETTINGS: Data from 2 referral centers were used. PATIENTS: Patients who completed the questionnaires regarding quality of life and social condition were included. MAIN OUTCOME MEASURES: The Hirschsprung\u27s Disease and Anorectal Malformations Quality of Life disease-specific questionnaire (8 dimensions explored; each scored from 0 to 100 maximum score) and a sociodemographic questionnaire were sent to identified patients. Sociodemographic data were compared with those of the French general population. RESULTS: Thirty-four patients had Hirschsprung disease (men, 76%; mean age, 32 years) were included in the study. Mean total Hirschsprung\u27s Disease and Anorectal Malformations Quality of Life score was 611 of 800 (maximum score 800). The 2 most impaired dimensions were "physical symptoms" and "diarrhea" (62.9/100 and 73.6/100). Fecal continence was only marginally affected (mean score, 89/100). Patients with Hirschsprung disease achieved better educational levels than the French general population. Parental and marital status did not differ between the 2 groups. LIMITATIONS: This study had the limitations inherent to a retrospective study. CONCLUSION: The quality of life of adult patients with Hirschsprung disease sequelae is marginally impaired in this study. Despite the consequences of this congenital abnormality, the condition eventually achieved can be considered as satisfactory. See Video Abstract at http://links.lww.com/DCR/A917

Staged gastroschisis closure using Alexis wound retractor: first experiences

INTRODUCTION: The aim of this study is to analyze the effectiveness of an Alexis wound retractor (AWR) device for staged gastroschisis closures. PATIENTS AND METHODS: AWR device was used to cover unreduced viscera of a gastroschisis when primary abdominal wall closure was not convenient. The eviscerated organs were covered with one of the two spring-loaded rings of the AWR inserted underneath the abdominal wall. Gradual reduction was guaranteed through careful traction on the external ring. We retrospectively analyzed the prenatal, post-natal and operative data of the first patients treated with AWR and report their post-operative outcomes. RESULTS: The AWR device was used for staged closure in eight cases. Complete reduction and fascial closure were performed at a median of 3.5 ± 1.6 days. Ventilatory support was necessary for 4.0 ± 3 days and full parenteral feeds for 7.5 ± 6.1 days after fascial closure. Median full enteral feeding was observed at 18 ± 12.5 days after closure allowing discharge in a median period of 30.5 ± 15.6 days after closure. CONCLUSION: The AWR device is not only a safe and efficient silo for a progressive reduction of severe gastroschisis, but also an interesting tool for continuous stretching leading to an increase of the peritoneal cavity volume, enhancing the equalizing of the viscero-abdominal disproportion