Laparoscopic percutaneous extraperitoneal closure for inguinal hernia: learning curve for attending surgeons and residents.

BACKGROUND/PURPOSE: Laparoscopic percutaneous extraperitoneal closure (LPEC) for pediatric inguinal hernia is a simple technique in which a purse-string suture made of nonabsorbable material is placed extraperitoneally around the hernia orifice by a special suture needle (Lapaherclosure™). Concerns have been raised about the extensive learning curve for both attending surgeons and residents to master this technique. This study assesses the difference in learning curves for the safe performance of LPEC by attending surgeons and residents. METHODS: A retrospective analysis was performed on the surgical charts of 409 consecutive patients (175 girls, 234 boys) who had undergone LPEC for inguinal hernia repair from December 2005 to December 2011 at Jikei University Hospital. The number of operation needed by attending surgeons and residents to reach the appropriate operation time was analyzed by the Mann-Whitney U test. RESULTS: LPEC was performed by three attending surgeons and four residents who had not previously performed LPEC. The standard operation time for LPEC by attending surgeons who have performed more than 100 LPEC cases safely is 30 min. In our study, the attending surgeons needed a mean of 12 operations (range, 10-16) to reach 30 min for LPEC. Three residents needed a mean of 31 operations (range, 27-33) to reach 30 min for LPEC. The fourth resident could not perform LPEC in 30 min or less. The difference between the number of operations needed by the attending surgeons and the residents to perform LPEC safely was statistically significant (P < 0.05). The overall incidence of contralateral patent processus vaginalis was 47.9 %. CONCLUSIONS: Our learning curve analysis showed that whereas attending surgeons needed a mean of 12 operations to perform LPEC repairs safely in 30 min or less, residents needed more than 30 operations to safely perform LPEC repairs without supervision.

Delayed primary reconstruction of esophageal atresia and distal tracheoesophageal fistula in a 471-g infant.

INTRODUCTION: Waterston et al. have classified the risk of morbidity in infants with esophageal atresia and tracheoesophageal fistula. However, few cases of esophageal atresia with distal tracheoesophageal fistula in extremely low birth weights infants have been reported. In such infants, the selection of primary reconstruction or staged repair remains controversial. In the present report, we describe the difficulties of perioperative management of such small infants and discuss how to rescue them. PRESENTATION OF CASE: A 471-g female infant was delivered at 28 weeks' gestation via cesarean section. Esophageal atresia with distal tracheoesophageal fistula was diagnosed. Esophageal banding and gastrostomy were performed via laparotomy on day 1. On day 74, when the infant weighed almost 1000g, airway management was discontinued. On day 136, endotracheal intubation again became necessary because of respiratory problems, and the esophagus was reconstructed on day 141. Despite this operation, the patient died on day 276 because of continuing respiratory problems. DISCUSSION: Esophageal banding is considered an appropriate treatment for respiratory problems in such extremely low weight infants. However, the timing of dissection of the tracheoesophageal fistula after esophageal banding is extremely important. CONCLUSION: In the present case, ligation of the tracheoesophageal fistula and esophageal reconstruction should have been performed as soon as possible.

[Diagnosis of mild hemophilia A made by massive intraabdominal bleeding in a 13-year-old boy].

We report a 13-year-old boy who had massive intra-abdominal bleeding without a history of bleeding episodes or traumatic cause of bleeding. The patient underwent surgical treatment because bleeding was not controlled after treatment with tranexamic acid and transfusions including fresh-frozen plasma. Bleeding was traced to the lower left lobe of the liver. The mother's side of the family had a history of bleeding episodes in the boy's grandfather, great uncle, and son of a great aunt. A low level of plasma factor VIII coagulant activity (22%) led to a diagnosis of mild hemophilia A. Compared with severe hemophilia, mild hemophilia is more difficult to diagnose because bleeding episodes are less frequent. Most cases are found after incidental trauma or uncontrolled surgery-related bleeding, there is rarely a family history of hemophilia and activated partial thromboplastin time is normal or slightly prolonged. However, bleeding episodes in mild hemophilia may result in excessive, sometimes life-threatening hemorrhage and require early diagnosis and replacement treatment with adequate amounts of factor VIII, as in severe hemophilia.

Risk factors of infection of implanted device after the Nuss procedure.

PURPOSE: The Nuss procedure is a minimally invasive procedure for the correction of pectus excavatum. It involves insertion of a substernal metal bar. A feared complication of any implantation procedure is infection, which often requires removal of the implanted device. This report describes the authors' experience with infectious complications after the Nuss procedure. METHODS: The study included 195 patients diagnosed with pectus excavatum. We performed the Nuss procedure under thoracoscopic control on all the patients. Factors analyzed for all patients included bar infection, sex, age, number of bars, and season of the year during which the operation was performed. RESULTS: Of the 195 study patients, there were 11 patients who suffered postoperative infectious complications, including 7 patients with cellulitis and 4 patients with bar infections. We removed the infected bars from three of the patients with bar infections. Ten of the patients with infected bar had undergone their operations in the summer. Sex, age and number of bars did not differ significantly between patients with or without infections. However, a significantly higher number of infections occurred among patients who underwent the Nuss procedure in the summer compared with the other seasons of the year (P < 0.05, Kruskal-Wallis Test). CONCLUSION: All patients with cellulitis successfully recovered with conservative treatment. However, 75 % of the patients with bar infections required removal of the infected device. Our study results showed that performance of the Nuss procedure during summer is a risk factor for postoperative infection. We recommend that particularly careful technique must be used during summer to prevent postoperative infections following the Nuss procedure.

EphA2 as a glioma-associated antigen: a novel target for glioma vaccines.

EphA2 is a receptor tyrosine kinase and is frequently overexpressed in a wide array of advanced cancers. We demonstrate in the current study that the EphA2 protein is restrictedly expressed in primary glioblastoma multiforme and anaplastic astrocytoma tissues in comparison to normal brain tissues. To evaluate the possibility of targeting EphA2 in glioma vaccine strategies, we stimulated human leukocyte antigen (HLA) A2+ peripheral blood mononuclear cells (PBMCs) obtained from healthy donors and glioma patients with autologous dendritic cells (DCs) loaded with synthetic EphA2883-891 peptide (TLADFDPRV), which has previously been reported to induce interferon-gamma in HLA-A2+ PBMCs. Stimulated PBMCs demonstrated antigen-specific cytotoxic T lymphocyte (CTL) responses as detected by specific lysis of T2 cells loaded with the EphA2883 peptide as well as HLA-A2+ glioma cells, SNB19 and U251, that express EphA2. Furthermore, in vivo immunization of HLA-A2 transgenic HHD mice with the EphA2883-891 peptide resulted in the development of an epitope-specific CTL response in splenocytes, despite the fact that EphA2883-891 is an autoantigen in these mice. Taken together, these data suggest that EphA2883-891 may be an attractive antigen epitope for molecularly targeted glioma vaccines.

Delivery of dendritic cells engineered to secrete IFN-alpha into central nervous system tumors enhances the efficacy of peripheral tumor cell vaccines: dependence on apoptotic pathways.

We tested whether modulation of the CNS-tumor microenvironment by delivery of IFN-alpha-transduced dendritic cells (DCs: DC-IFN-alpha) would enhance the therapeutic efficacy of peripheral vaccinations with cytokine-gene transduced tumor cells. Mice bearing intracranial GL261 glioma or MCA205 sarcoma received peripheral immunizations with corresponding irradiated tumor cells engineered to express IL-4 or GM-CSFs, respectively, as well as intratumoral delivery of DC-IFN-alpha. This regimen prolonged survival of the animals and induced tumor-specific CTLs that expressed TRAIL, which in concert with perforin and Fas ligand (FasL) was involved in the tumor-specific CTL activity of these cells. The in vivo antitumor activity associated with this approach was abrogated by administration of neutralizing mAbs against TRAIL or FasL and was not observed in perforin-/-, IFN-gamma-/-, or FasL-/- mice. Transduction of the tumor cells with antiapoptotic protein cellular FLIP rendered the gene-modified cells resistant to TRAIL- or FasL-mediated apoptosis and to CTL killing activity in vitro. Furthermore, the combination therapeutic regimen was ineffective in an intracranial cellular FLIP-transduced MCA205 brain tumor model. These results suggest that the combination of intratumoral delivery of DC-IFN-alpha and peripheral immunization with cytokine-gene transduced tumor cells may be an effective therapy for brain tumors that are sensitive to apoptotic signaling pathways.

IL-4-transfected tumor cell vaccines activate tumor-infiltrating dendritic cells and promote type-1 immunity.

We previously demonstrated that IL-4 gene-transfected glioma cell vaccines induce effective therapeutic immunity in preclinical glioma models, and have initiated phase I trials of these vaccines in patients with malignant gliomas. To gain additional mechanistic insight into the efficacy of this approach, we have treated mice bearing the MCA205 (H-2(b)) or CMS-4 (H-2(d)) sarcomas. IL-12/23 p40(-/-) and IFN-gamma(-/-) mice, which were able to reject the initial inoculation of IL-4 expressing tumors, failed to mount a sustained systemic response against parental (nontransfected) tumor cells. Paracrine production of IL-4 in vaccine sites promoted the accumulation and maturation of IL-12p70-secreting tumor-infiltrating dendritic cells (TIDCs). Adoptive transfer of TIDCs isolated from vaccinated wild-type, but not IL-12/23 p40(-/-), mice were capable of promoting tumor-specific CTL responses in syngeneic recipient animals. Interestingly, both STAT4(-/-) and STAT6(-/-) mice failed to reject IL-4-transfected tumors in concert with the reduced capacity of TIDCs to produce IL-12p70 and to promote specific antitumor CTL reactivity. These results suggest that vaccines consisting of tumor cells engineered to produce the type 2 cytokine, IL-4, critically depend on type 1 immunity for their observed therapeutic efficacy.

Epidermal growth factor receptor-transfected bone marrow stromal cells exhibit enhanced migratory response and therapeutic potential against murine brain tumors.

We have created a novel cellular vehicle for gene therapy of malignant gliomas by transfection of murine bone marrow stroma cells (MSCs) with a cDNA encoding epidermal growth factor receptor (EGFR). These cells (EGFR-MSCs) demonstrate enhanced migratory responses toward glioma-conditioned media in comparison to primary MSCs in vitro. Enhanced migration of EGFR-MSC was at least partially dependent on EGF-EGFR, PI3-, MAP kinase kinase, and MAP kinases, protein kinase C, and actin polymerization. Unlike primary MSCs, EGFR-MSCs were resistant to FasL-mediated cytotoxicity and were capable of stimulating allogeneic mixed lymphocyte reaction, suggesting EGFR-MSCs possess suitable characteristics as vehicles for brain tumor immuno-gene therapy. Following injection at various sites, including the contralateral hemisphere in the brain of syngeneic mice, EGFR-MSCs were able to migrate toward GL261 gliomas or B16 melanoma in vivo. Finally, intratumoral injection with EGFR-MSC adenovirally engineered to secrete interferon-alpha to intracranial GL261 resulted in significantly prolonged survival in comparison to controls. These data indicate that EGFR-MSCs may serve as attractive vehicles for infiltrating brain malignancies such as malignant gliomas.

Vaccination with EphA2-derived T cell-epitopes promotes immunity against both EphA2-expressing and EphA2-negative tumors.

BACKGROUND: A novel tyrosine kinase receptor EphA2 is expressed at high levels in advanced and metastatic cancers. We examined whether vaccinations with synthetic mouse EphA2 (mEphA2)-derived peptides that serve as T cell epitopes could induce protective and therapeutic anti-tumor immunity. METHODS: C57BL/6 mice received subcutaneous (s.c.) vaccinations with bone marrow-derived dendritic cells (DCs) pulsed with synthetic peptides recognized by CD8+ (mEphA2671-679, mEphA2682-689) and CD4+ (mEphA230-44) T cells. Splenocytes (SPCs) were harvested from primed mice to assess the induction of cytotoxic T lymphocyte (CTL) responses against syngeneic glioma, sarcoma and melanoma cell lines. The ability of these vaccines to prevent or treat tumor (s.c. injected MCA205 sarcoma or B16 melanoma; i.v. injected B16-BL6) establishment/progression was then assessed. RESULTS: Immunization of C57BL/6 mice with mEphA2-derived peptides induced specific CTL responses in SPCs. Vaccination with mEPhA2 peptides, but not control ovalbumin (OVA) peptides, prevented the establishment or prevented the growth of EphA2+ or EphA2-negative syngeneic tumors in both s.c. and lung metastasis models. CONCLUSIONS: These data indicate that mEphA2 can serve as an attractive target against which to direct anti-tumor immunity. The ability of mEphA2 vaccines to impact EphA2-negative tumors such as the B16 melanoma may suggest that such beneficial immunity may be directed against alternative EphA2+ target cells, such as the tumor-associated vascular endothelial cells.

Delivery of interferon-alpha transfected dendritic cells into central nervous system tumors enhances the antitumor efficacy of peripheral peptide-based vaccines.

We evaluated the effects, on immunity and survival, of injection of interferon (IFN)-alpha-transfected dendritic cells (DC-IFN-alpha) into intracranial tumors in mice immunized previously with syngeneic dendritic cells (DCs) pulsed either with ovalbumin-derived CTL or T helper epitopes. These immunizations protected animals from s.c. challenge with ovalbumin-expressing M05 melanoma (class I+ and class II-negative). Notably, antiovalbumin CTL responses were observed in animals vaccinated with an ovalbumin-derived T helper epitope but only after the mice were challenged with M05 cells. This cross-priming of CTL was dependent on both CD4+ and CD8+ T cells. Because we observed that s.c., but not intracranial, tumors were infiltrated with CD11c+ DCs, and because IFN-alpha promotes the activation and survival of both DCs and T cells, we evaluated the combinational antitumor effects of injecting adenoviral (Ad)-IFN-alpha-engineered DCs into intracranial M05 tumors in preimmunized mice. Delivery of DC-IFN-alpha prolonged survival. This was most notable for animals prevaccinated with both the CTL and T helper ovalbumin epitopes, with 60% (6 of 10) of mice (versus 0 of 10 of control animals) surviving for > 80 days after tumor challenge. DC-IFN-alpha appeared to persist longer than mock-transfected DCs within the intracranial tumor microenvironment, and DC-IFN-alpha-treated mice exhibited enhanced levels of ovalbumin-specific CTL in draining cervical lymph nodes. On the basis of these results, we believe that local expression of IFN-alpha by DCs within the intracranial tumor site may enhance the clinical efficacy of peripheral vaccine approaches for brain tumors.

Successful in utero gene transfer using a gene gun in midgestational mouse fetuses.

BACKGROUND/PURPOSE: In utero gene therapy offers a number of potential advantages over postnatal gene therapy. A latest method of gene transfer to fetuses in utero uses a new tool called a gene gun. The gene gun is less invasive and simpler than other in utero methods. The current study was designed to determine whether the gene gun is an effective tool for transferring genes to mouse fetuses in utero. METHODS: Using a gene gun, we transferred plasmids that included enhanced green fluorescent protein (EGFP) genes and cytomegalo virus promoters to the abdominal skin of 40 A/J fetal mice at each of 3 gestational ages (13, 14, or 15 days). Four or 5 days after gene transfer, the number of surviving fetuses was counted, and a color image of EGFP in the skin was analyzed for gene transfer rates by fluorescence microscopy. Survival rates were analyzed using Fisher's Exact test. RESULTS: The mean survival rate was 89.2% (107 of 120) in gene transfer fetuses and 91.7% (55 of 60) in controls. There is no difference in survival rate between gene transfer fetus and control. The highest gene transfer rate was 100% (37 of 37) at the gestational age of 14 days. The rate was 97.1% (34 of 35) at gestational ages of 13 and 15 days. CONCLUSIONS: The results of this study show that in utero gene transfer by gene gun is a less-invasive technique, and the gene gun is an effective tool transferring genes to mouse fetuses in utero.

Gene therapy and biologic therapy with interleukin-4.

For more than two decades, there has been a concerted effort to define the biology of, and develop the clinical applications for, cytokines that influence the immune system. However, intrinsic potency and toxicity have complicated application of cytokines as therapeutic agents when applied systemically. Indeed, one of the major characteristics of most cytokines is that they regulate immunity at a local or regional level, and systemic levels provided by most conventional schema fail to mimic the induction of an effective immune response. IL-4 has pleiotropic effects on immune cells of multiple lineages, endothelial cells and tumor cells. Accumulating data in pre-clinical studies demonstrate that sustained expression of IL-4 at the targeted organs or tissues may provide an effective means for therapy of variety of diseases including cancers and immunologic disorders. This review discusses biological properties and therapeutic applications of IL-4, particularly when it is delivered as a transgene in the settings of gene therapy.