Hirschsprung disease.

Hirschsprung disease (HSCR) is a rare congenital intestinal disease that occurs in 1 in 5,000 live births. HSCR is characterized by the absence of ganglion cells in the myenteric and submucosal plexuses of the intestine. Most patients present during the neonatal period with the first meconium passage delayed beyond 24 h, abdominal distension and vomiting. Syndromes associated with HSCR include trisomy 21, Mowat-Wilson syndrome, congenital central hypoventilation syndrome, Shah-Waardenburg syndrome and cartilage-hair hypoplasia. Multiple putative genes are involved in familial and isolated HSCR, of which the most common are the RET proto-oncogene and EDNRB. Diagnosis consists of visualization of a transition zone on contrast enema and confirmation via rectal biopsy. HSCR is typically managed by surgical removal of the aganglionic bowel and reconstruction of the intestinal tract by connecting the normally innervated bowel down to the anus while preserving normal sphincter function. Several procedures, namely Swenson, Soave and Duhamel procedures, can be undertaken and may include a laparoscopically assisted approach. Short-term and long-term comorbidities include persistent obstructive symptoms, enterocolitis and soiling. Continued research and innovation to better understand disease mechanisms holds promise for developing novel techniques for diagnosis and therapy, and improving outcomes in patients.

Approach and Technique for Cesarean Section to Immediate Resection for High-Risk Sacrococcygeal Teratomas.

INTRODUCTION: Ex-utero intrapartum treatment has been established as an option for fetal and perinatal surgeons to deliver patients with sacrococcygeal teratomas (SCTs) which are causing significant fetal distress and possible in-utero fetal demise. However, ex-utero intrapartum treatment procedures carry significant maternal risk and morbidity. Herein, we report an alternative technique of Cesarean section to immediate resection (CSIR) for managing high-risk SCTs. METHODS: A retrospective institutional review board-approved review was performed on all SCTs evaluated at our fetal center from May 2014 to September 2020. Demographics; prenatal imaging characteristics; prenatal interventions; and postnatal surgery data including operative time, estimated blood loss, pathology, and outcomes were collected. Outcomes of interest included surveillance serum alpha-fetoprotein levels, imaging surveillance, developmental milestones, and the presence or absence of constipation or fecal incontinence. RESULTS: A total of 20 patients with prenatal diagnosis of SCT were evaluated. Mothers who transferred their care to another institution after diagnosis were excluded from this study. Twelve neonates underwent standard postnatal resection. Three neonates underwent emergent CSIR for high output cardiac failure, fetal anemia, or concerns for in-utero hemorrhagic rupture. The median (interquartile range) operative time was 231.5 (113) minutes for the standard operative group versus 156 min in the CSIR group. We present three patients who underwent immediate resection after emergent Cesarean section. We report 100% survival for the three consecutive cases. CONCLUSIONS: CSIR is a safe and feasible approach for managing appropriately selected high-risk SCTs with signs of hydrops, fetal distress, or fetal anemia. Despite patient prematurity, we demonstrated 100% survival of three consecutive cases. We suggest that CSIR be considered an option in the management algorithm for high-risk SCTs.

Association for Academic Surgery/Society of University Surgeons research awards are highly successful in fostering future surgeon-scientists.

BACKGROUND: The surgeon-scientist brings a unique perspective to surgical research. The Association of Academic Surgeons and Society of University Surgeons foster the development of surgeon-scientists through foundation awards to residents and junior faculty. We sought to evaluate the academic success of surgeons who received an Association for Academic Surgery/Society of University Surgeons award. METHODS: Information was collected for individuals who received a resident or junior faculty research award from the Association for Academic Surgery or Society of University Surgeons. Google Scholar, Scopus, and the National Institutes of Health Research Portfolio Online Reporting Tools: Expenditures and Results were used to assess scholarly achievements. RESULTS: Eighty-two resident awardees were included, 31 (38%) of whom were female. Thirteen (24%) are now professors, 12 (22%) are division chiefs, and 4 (7%) are department chairs. Resident awardees have a median of 886 citations (interquartile range 237-2,111) and an H-index of 14 (interquartile range 7-23). Seven (13%) went on to receive K08/K23 awards, and 7 (13%) received R01s, with a total of about $200 million in National Institutes of Health funding (79-fold return on investment). Thirty-four junior faculty awardees were included, 10 (29%) of whom were female. Thirteen (38%) are now professors, 12 (35%) are division chiefs, and 7 (21%) are department chairs. Faculty awardees have a median of 2,617 citations (interquartile range 1,343-7,857) and an H-index of 25 (interquartile range 18-49). Four (12%) received K08 or K23 awards, and 10 (29%) received R01s, with about $139 million in National Institutes of Health funding (98-fold return on investment). CONCLUSION: Association for Academic Surgery/Society of University Surgeons research awardees experience high degrees of success in academic surgery. Most resident awardees pursue fellowship training and remain in academic surgery. A high percentage of both faculty and resident awardees hold leadership positions and successfully achieve National Institutes of Health funding.

Targeting the Inducible T-cell Costimulator (ICOS) in Patients with Relapsed/Refractory T-follicular Helper Phenotype Peripheral T-cell and Angioimmunoblastic T-cell Lymphoma.

PURPOSE: Proliferation of T-follicular helper (TFH) CD4+ T cells is a postulated pathogenic mechanism for T-cell non-Hodgkin lymphomas (T-NHL). The inducible T-cell costimulator (ICOS) is highly expressed by TFH, representing a potential target. MEDI-570 is a monoclonal antibody against ICOS, which eliminates ICOS+ cells in preclinical models. PATIENTS AND METHODS: We report the safety, pharmacokinetics (PK), pharmacodynamics (PD), and clinical activity of MEDI-570 in T-NHL. NCI-9930 is a phase I, first-in-human study of MEDI-570 in relapsed/refractory malignant T-NHL known to express ICOS. MEDI-570 was administered intravenously every 3 weeks for up to 12 cycles. Primary endpoints were safety, dose-limiting toxicities (DLT), and recommended phase II dose (RP2D). Secondary and exploratory endpoints included efficacy parameters and various correlative studies. This study is supported by the National Cancer Institute (NCT02520791). RESULTS: Twenty-three patients were enrolled and received MEDI-570 at five dose levels (0.01-3 mg/kg). Sixteen (70%) had angioimmunoblastic T-cell lymphoma (AITL); median age was 67 years (29-86) and the median prior lines of therapies was 3 (1-16). Most common grade 3 or 4 adverse events were decreased CD4+ T cells (57%), lymphopenia (22%), anemia (13%), and infusion-related reactions (9%). No DLTs were observed. The RP2D was determined at 3 mg/kg. Analysis of T-cell subsets showed reductions in CD4+ICOS+ T cells reflecting its effects on TFH cells. The response rate in AITL was 44%. CONCLUSIONS: MEDI-570 was well tolerated and showed promising clinical activity in refractory AITL. MEDI-570 resulted in sustained reduction of ICOS+ T lymphocytes.

Safety and Efficacy of MEDI0457 plus Durvalumab in Patients with Human Papillomavirus-Associated Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma.

PURPOSE: Tumoral programmed cell death ligand-1 (PD-L1) expression is common in human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC). We assessed whether a DNA vaccine targeting HPV-16/18 E6/E7 with IL12 adjuvant (MEDI0457) combined with the PD-L1 inhibitor durvalumab could enhance HPV-specific T-cell response and improve outcomes in recurrent/metastatic HPV-16/18-associated HNSCC. PATIENTS AND METHODS: In this phase Ib/IIa study, immunotherapy-naïve patients with ≥1 previous platinum-containing regimen (neoadjuvant/adjuvant therapy or for recurrent/metastatic disease) received MEDI0457 7 mg intramuscularly with electroporation on weeks 1, 3, 7, and 12, then every 8 weeks, plus durvalumab 1,500 mg intravenously on weeks 4, 8, and 12, then every 4 weeks, until confirmed progression and/or unacceptable toxicity. Coprimary objectives were safety and objective response rate (ORR; H0: ORR ≤ 15%); secondary objectives included 16-week disease control rate (DCR-16), overall survival (OS), and progression-free survival (PFS). RESULTS: Of 35 treated patients, 29 were response evaluable (confirmed HPV-associated disease; received both agents). ORR was 27.6% [95% confidence interval (CI), 12.7-47.2; four complete responses, four partial responses]; responses were independent of PD-L1 tumor-cell expression (≥25% vs. <25%). DCR-16 was 44.8% (95% CI, 26.5-64.3). Median PFS was 3.5 months (95% CI, 1.9-9.0); median OS was 29.2 months (15.2-not calculable). Twenty-eight (80.0%) patients had treatment-related adverse events [grade 3: 5 (14.3%); no grade 4/5], resulting in discontinuation in 2 (5.7%) patients. HPV-16/18-specific T cells increased on treatment; 4 of 8 evaluable patients had a >2-fold increase in tumor-infiltrating CD8+ T cells. CONCLUSIONS: MEDI0457 plus durvalumab was well tolerated. While the primary efficacy endpoint was not reached, clinical benefit was encouraging.

Ancillary documents for NIH grant applications: The pages beyond the science.

Preparing a grant proposal is no small feat, especially for research (R-series) grants from the National Institutes of Health. The National Institutes of Health is the largest public funder of biomedical research in the world, and as such, procuring a research grant from the National Institutes of Health is one of the ultimate benchmarks of success for a surgeon-scientist. Most investigators are familiar with the page limits for most R-series grants (12 pages for an R01 and 6 pages for an R21), with the addition of a single page allotted for the specific aims. Interestingly, despite the usual focus on the aforementioned research section, the rest of the application can routinely consist of an additional 100 to 150 pages, which means that pages allotted for the specific aims and research strategy represent only 10% of the complete application package. For busy surgeons, it is this abundance of ancillary documentation that can make preparing a research grant particularly onerous. Fortunately, for some, support exists within the department to help prepare much of this documentation by drawing from previous sources, templates, and boilerplate language that has been developed. Although these resources can significantly reduce the burden on individual investigators, there is a danger of leaning on generalized templates that can dilute the message of the overall grant proposal and introduce extraneous or incorrect information that can ultimately impact the cohesiveness and ultimately the competitiveness of the grant. The focus of this article is to educate surgeon-scientists regarding the purpose and importance of the ancillary information required for National Institutes of Health research grants and how to make the most of institutional resources while tailoring these materials to create a cohesive, competitive grant application.

Case report: Spindle cell neoplasm presenting as a spontaneous intestinal perforation in a term infant.

Spontaneous intestinal perforations in the neonatal population are mostly associated with low birth weight, prematurity, and necrotizing enterocolitis. Spontaneous intestinal perforation in the absence of these risk factors is extremely rare and should raise clinical concern for an underlying bowel pathology. Here we present a unique case of a normal-weight, full-term girl with spontaneous intestinal perforation due to a spindle cell neoplasm with a novel BRAF mutation and infantile fibrosarcoma-like morphology. Though rare, malignancy should be considered in the differential diagnosis for bowel perforation in an otherwise healthy, term infant as complete surgical excision can be curative.

Case Report: The Medical and Surgical Management of an Infant With Extreme Prematurity and Fetus-In-Fetu.

Fetus-in-fetu (FIF) is a rare congenital anomaly where a parasitic twin is within the body of a host twin. FIF is reported to occur in 1:500,000 live births. Herein, we report the first case of the medical and surgical treatment of a FIF patient who was born with extreme prematurity at 25-weeks gestation. With the multi-disciplinary coordination of neonatology, surgery, and interventional radiology, the patient was able to achieve a window of medical stability 4 weeks after birth. A decision was made at that time to proceed with an intra-abdominal and perineal resection of the FIF. The FIF was successfully resected and the patient was able to recover from the operation, with eventual discharge from the NICU. In conclusion, extreme prematurity and FIF may be amenable to surgical resection and a multi-disciplinary approach is crucial to achieve the desired outcome.

Angiosarcoma of the Pancreas in a Pediatric Patient With an Activating KDR-Internal Tandem Duplication: A Case Report and Review of the Literature.

Pancreatic angiosarcoma is an exceedingly rare malignancy accounting for <1% of pancreatic neoplasms. A very limited number of pancreatic angiosarcomas have been reported in the literature without any cases described in children. We present the case of a 17-year-old female diagnosed with angiosarcoma of the pancreas following pancreaticoduodenectomy for a pancreatic mass, initially presumed to be a solid pseudopapillary neoplasm of the pancreas. The angiosarcoma was found to have a novel activating internal tandem duplication in the KDR gene (KDR-internal tandem duplication). We discuss the current literature on this disease process. This is the first reported case of pancreatic angiosarcoma in a pediatric patient and the first with an activating KDR-internal tandem duplication.

Surgical Approach to Pediatric Ovarian Growing Teratoma Syndrome: A Case Report.

BACKGROUND: Growing teratoma syndrome is defined as conversion of a metastatic immature tumor to a mature tumor after adjuvant chemotherapy and remains an area of investigation because of its unclear pathogenesis. Because of its risk of malignant transformation, the primary treatment strategy for pediatric patients is surgical resection. CASE: In this report we present a case of a pediatric patient with recurrent growing teratoma syndrome who was treated with chemotherapy, debulking procedures, and cryoablation for the growing nodules throughout her abdominal cavity. The patient has had a good clinical outcome without recurrent malignant tumor. SUMMARY AND CONCLUSION: These masses do not always regress with chemotherapy and complete surgical excision or ablation should be attempted when possible.

High-dose adenosine for treatment of refractory paroxysmal supraventricular tachycardia.

Paroxysmal supraventricular tachycardia (PSVT) is one of the more common arrhythmias requiring treatment in the emergency department. Intravenous adenosine is recommended as the initial medication of choice for treatment of PSVT, given in escalating doses up to a maximum of 12 mg. With a serum half-life of less than 10 s, adenosine must be given rapidly to allow for adequate time for it to reach the heart via venous return. In over 10% of adult patients, PSVT will not be terminated with maximum doses of adenosine. We report a case of a patient requiring a higher-than recommended dose of adenosine for termination of PSVT. The patient had a history of pulmonary hypertension with resultant right heart failure at the time of presentation. We believe the higher dose of adenosine was necessary in this patient because of the impaired venous return to her right heart. This case indicates that patients with impaired venous return to the right heart may require higher-than-recommended doses of adenosine for effective termination of PSVT.

Vaccination with synthetic long peptide formulated with CpG in an oil-in-water emulsion induces robust E7-specific CD8 T cell responses and TC-1 tumor eradication.

BACKGROUND: Despite considerable efforts at developing therapeutic vaccines for cancer, clinical translation of preclinical successes has been challenging, largely due to the difficulty of inducing strong and sustained cytotoxic T lymphocyte (CTL) responses in patients. Several peptide-based cancer vaccines have failed to show sustainable tumor regression in the clinic, possibly because of a lack of optimization of both the adjuvant and antigen components of the preparations. Here, we aimed to develop and optimize a vaccine format utilizing a synthetic long peptide (SLP) containing the human papilloma virus 16 (HPV16) E7 antigen, with a centrally located defined MHC class I epitope, and evaluate its immunogenicity and efficacy in combination with various adjuvant formulations. METHODS: E731-73 SLP was tested alone or in combination with toll-like receptor (TLR)3, TLR4, TLR7/8 and TLR9 agonists and formulated in oil-in-water (o/w) or water-in-oil (w/o) emulsions to determine a vaccine format inducing a robust CD8 T cell response in murine models. Once a lead vaccine format was determined, we examined its ability to inhibit tumor growth in the murine TC-1 model that expresses HPV16 E7 antigen. RESULTS: We identified the TLR9 agonist CpG formulated in a squalene-based o/w emulsion as the most potent adjuvant, inducing the expansion of multifunctional antigen specific CD8 T cells with cytolytic potential. We also demonstrated that SLP E731-73 + CpG + o/w emulsion vaccine can provide prophylactic and more importantly, therapeutic benefit in the TC-1 murine tumor model. CONCLUSIONS: Our results demonstrate that the novel vaccine format E7 SLP + CpG delivered in an o/w emulsion holds potential for the promotion of strong CTL responses and tumor eradication and encourages further development of peptide/adjuvant vaccines in cancer immunotherapy strategies.

CD4+ T Cells Drive Lung Disease Enhancement Induced by Immunization with Suboptimal Doses of Respiratory Syncytial Virus Fusion Protein in the Mouse Model.

Respiratory syncytial virus (RSV) infection of seronegative children previously immunized with formalin-inactivated (FI) RSV has been associated with serious enhanced respiratory disease (ERD). The phenomenon was reproduced in the cotton rat and the mouse, and both preclinical models have been routinely used to evaluate the safety of new RSV vaccine candidates. More recently, we demonstrated that immunizations with suboptimal doses of the RSV fusion (F) antigen, in its post- or prefusion conformation, and in the presence of a Th1-biasing adjuvant, unexpectedly led to ERD in the cotton rat model. To assess if those observations are specific to the cotton rat and to elucidate the mechanism by which vaccination with low antigen doses can drive ERD post-RSV challenge, we evaluated RSV post-F antigen dose de-escalation in BALB/c mice in the presence of a Th1-biasing adjuvant. While decreasing antigen doses, we observed an increase in lung inflammation associated with an upregulation of proinflammatory cytokines. The amplitude of the lung histopathology was comparable to that of FI-RSV-induced ERD, confirming the observations made in the cotton rat. Importantly, depletion of CD4+ T cells prior to viral challenge completely abrogated ERD, preventing proinflammatory cytokine upregulation and the infiltration of T cells, neutrophils, eosinophils, and macrophages into the lung. Overall, low-antigen-dose-induced ERD resembles FI-RSV-induced ERD, except that the former appears in the absence of detectable levels of viral replication and in the context of a Th1-biased immune response. Taken together, our observations reinforce the recent concept that vaccines developed for RSV-naïve individuals should be systematically tested under suboptimal dosing conditions.IMPORTANCE RSV poses a significant health care burden and is the leading cause of serious lower-respiratory-tract infections in young children. A formalin-inactivated RSV vaccine developed in the 1960s not only showed a complete lack of efficacy against RSV infection but also induced severe lung disease enhancement in vaccinated children. Since then, establishing safety in preclinical models has been one of the major challenges to RSV vaccine development. We recently observed in the cotton rat model that suboptimal immunizations with RSV fusion protein could induce lung disease enhancement. In the present study, we extended suboptimal dosing evaluation to the mouse model. We confirmed the induction of lung disease enhancement by vaccinations with low antigen doses and dissected the associated immune mechanisms. Our results stress the need to evaluate suboptimal dosing for any new RSV vaccine candidate developed for seronegative infants.

Surgical Management of Idiopathic Constipation in Pediatric Patients.

Constipation is a common childhood problem, but an anatomic or physiologic cause is identified in fewer than 5% of children. By definition, idiopathic constipation is a diagnosis of exclusion. Careful clinical evaluation and thoughtful use of imaging and other testing can help exclude specific causes of constipation and guide therapy. Medical management with laxatives is effective for the majority of constipated children. For those patients unresponsive to medications, however, several surgical options can be employed, including anal procedures, antegrade colonic enemas, colorectal resection, and intestinal diversion. Judicious use of these procedures in properly selected patients and based on appropriate preoperative testing can lead to excellent outcomes. This review summarizes the surgical options available for managing refractory constipation in children and provides guidance on how to choose the best procedure for a given patient.

IRAK1 Augments Cancer Stemness and Drug Resistance via the AP-1/AKR1B10 Signaling Cascade in Hepatocellular Carcinoma.

Frequent relapse and drug resistance in patients with hepatocellular carcinoma (HCC) can be attributed to the existence of tumor-initiating cells (TIC) within the tumor bulk. Therefore, targeting liver TICs may improve the prognosis of these patients. From transcriptome sequencing of 16 pairs of clinical HCC samples, we report that interleukin-1 receptor-associated kinase 1 (IRAK1) in the TLR/IRAK pathway is significantly upregulated in HCC. IRAK1 overexpression in HCC was further confirmed at the mRNA and protein levels and correlated with advanced tumor stages and poor patient survival. Interestingly, IRAK4, an upstream regulator of IRAK1, was also consistently upregulated. IRAK1 regulated liver TIC properties, including self-renewal, tumorigenicity, and liver TIC marker expression. IRAK1 inhibition sensitized HCC cells to doxorubicin and sorafenib treatment in vitro via suppression of the apoptotic cascade. Pharmacological inhibition of IRAK1 with a specific IRAK1/4 kinase inhibitor consistently suppressed liver TIC populations. We identified aldo-keto reductase family 1 member 10 (AKR1B10) as a novel downstream target of IRAK1, which was found to be overexpressed in HCC and significantly correlated with IRAK1 expression. Knockdown of AKR1B10 negated IRAK1-induced TIC functions via modulation of the AP-1 complex. Inhibition of IRAK1/4 inhibitor in combination with sorafenib synergistically suppressed tumor growth in an HCC xenograft model. In conclusion, targeting the IRAK4/IRAK1/AP-1/AKR1B10 signaling pathway may be a potential therapeutic strategy against HCC.Significance: IRAK4/IRAK1/AP-1/AKR1B10 signaling pathway regulates cancer stemness and drug resistance and may be a novel therapeutic target in HCC. Cancer Res; 78(9); 2332-42. ©2018 AACR.

Neutralizing Alpha-Toxin Accelerates Healing of Staphylococcus aureus-Infected Wounds in Nondiabetic and Diabetic Mice.

Staphylococcus aureus wound infections delay healing and result in invasive complications such as osteomyelitis, especially in the setting of diabetic foot ulcers. In preclinical animal models of S. aureus skin infection, antibody neutralization of alpha-toxin (AT), an S. aureus-secreted pore-forming cytolytic toxin, reduces disease severity by inhibiting skin necrosis and restoring effective host immune responses. However, whether therapeutic neutralization of alpha-toxin is effective against S. aureus-infected wounds is unclear. Herein, the efficacy of prophylactic treatment with a human neutralizing anti-AT monoclonal antibody (MAb) was evaluated in an S. aureus skin wound infection model in nondiabetic and diabetic mice. In both nondiabetic and diabetic mice, anti-AT MAb treatment decreased wound size and bacterial burden and enhanced reepithelialization and wound resolution compared to control MAb treatment. Anti-AT MAb had distinctive effects on the host immune response, including decreased neutrophil and increased monocyte and macrophage infiltrates in nondiabetic mice and decreased neutrophil extracellular traps (NETs) in diabetic mice. Similar therapeutic efficacy was achieved with an active vaccine targeting AT. Taken together, neutralization of AT had a therapeutic effect against S. aureus-infected wounds in both nondiabetic and diabetic mice that was associated with differential effects on the host immune response.

Effects of ICOS+ T cell depletion via afucosylated monoclonal antibody MEDI-570 on pregnant cynomolgus monkeys and the developing offspring.

MEDI-570 is a fully human afucosylated monoclonal antibody (MAb) against Inducible T-cell costimulator (ICOS), highly expressed on CD4+ T follicular helper (TFH) cells. Effects of MEDI-570 were evaluated in an enhanced pre-postnatal development toxicity (ePPND) study in cynomolgus monkeys. Administration to pregnant monkeys did not cause any abortifacient effects. Changes in hematology and peripheral blood T lymphocyte subsets in maternal animals and infants and the attenuated infant IgG immune response to keyhole limpet hemocyanin (KLH) were attributed to MEDI-570 pharmacology. Adverse findings included aggressive fibromatosis in one dam and two infant losses in the high dose group with anatomic pathology findings suggestive of atypical lymphoid hyperplasia. The margin of safety relative to the no observed adverse effect level (NOAEL) for the highest planned clinical dose in the Phase 1a study was 7. This study suggests that women of child bearing potential employ effective methods of contraception while being treated with MEDI-570.

Stearoyl-CoA desaturase regulates sorafenib resistance via modulation of ER stress-induced differentiation.

BACKGROUND & AIMS: We investigated the functional role and clinical significance of stearoyl-CoA desaturase-1 (SCD1) mediated endoplasmic reticulum (ER) stress in regulating liver tumor-initiating cells (T-ICs) and sorafenib resistance, with the aim of developing a novel therapeutic strategy against hepatocellular carcinomas (HCCs). METHODS: We evaluated the clinic-pathological relevance of SCD1 and its correlation with sorafenib resistance in large cohorts of HCC clinical samples by qPCR and immunohistochemical analyses. Lentiviral-based overexpression and knockdown approaches were performed to characterize the functional roles of SCD1 in regulating liver T-ICs and sorafenib resistance. Molecular pathways mediating the phenotypic alterations were identified through RNA sequencing analysis and functional rescue experiments. The combinatorial effect of SCD1 inhibition and sorafenib was tested using a patient-derived tumor xenograft (PDTX) model. RESULTS: SCD1 overexpression was found in HCC, which was associated with shorter disease-free survival (p = 0.008, log rank test). SCD1 was found to regulate the populations of liver T-ICs; while its suppression by a SCD1 inhibitor suppressed liver T-ICs and sorafenib resistance. Interestingly, SCD1 was markedly upregulated in our established sorafenib-resistant PDTX model, and its overexpression predicts the clinical response of HCC patients to sorafenib treatment. Suppression of SCD1 forces liver T-ICs to differentiate via ER stress-induced unfolded protein response, resulting in an enhanced sensitivity to sorafenib. The PDTX#1 model, combined with sorafenib treatment and a novel SCD1 inhibitor (SSI-4), showed a maximal growth suppressive effect. CONCLUSIONS: SCD1-mediated ER stress regulates liver T-ICs and sorafenib sensitivity. Targeting SCD1 alone or in combination with sorafenib might be a novel personalized medicine against HCC. Lay summary: In this study, SCD1 was found to play a critical role in regulating liver tumor-initiating cells and sorafenib resistance through the regulation of ER stress-mediated differentiation. Targeting SCD1 in combination with sorafenib may be a novel therapeutic strategy against liver cancer.

Immunization with Low Doses of Recombinant Postfusion or Prefusion Respiratory Syncytial Virus F Primes for Vaccine-Enhanced Disease in the Cotton Rat Model Independently of the Presence of a Th1-Biasing (GLA-SE) or Th2-Biasing (Alum) Adjuvant.

Respiratory syncytial virus (RSV) infection of children previously immunized with a nonlive, formalin-inactivated (FI)-RSV vaccine has been associated with serious enhanced respiratory disease (ERD). Consequently, detailed studies of potential ERD are a critical step in the development of nonlive RSV vaccines targeting RSV-naive children and infants. The fusion glycoprotein (F) of RSV in either its postfusion (post-F) or prefusion (pre-F) conformation is a target for neutralizing antibodies and therefore an attractive antigen candidate for a pediatric RSV subunit vaccine. Here, we report the evaluation of RSV post-F and pre-F in combination with glucopyranosyl lipid A (GLA) integrated into stable emulsion (SE) (GLA-SE) and alum adjuvants in the cotton rat model. Immunization with optimal doses of RSV F antigens in the presence of GLA-SE induced high titers of virus-neutralizing antibodies and conferred complete lung protection from virus challenge, with no ERD signs in the form of alveolitis. To mimic a waning immune response, and to assess priming for ERD under suboptimal conditions, an antigen dose de-escalation study was performed in the presence of either GLA-SE or alum. At low RSV F doses, alveolitis-associated histopathology was unexpectedly observed with either adjuvant at levels comparable to FI-RSV-immunized controls. This occurred despite neutralizing-antibody titers above the minimum levels required for protection and with no/low virus replication in the lungs. These results emphasize the need to investigate a pediatric RSV vaccine candidate carefully for priming of ERD over a wide dose range, even in the presence of strong neutralizing activity, Th1 bias-inducing adjuvant, and protection from virus replication in the lower respiratory tract.IMPORTANCE RSV disease is of great importance worldwide, with the highest burden of serious disease occurring upon primary infection in infants and children. FI-RSV-induced enhanced disease, observed in the 1960s, presented a major and ongoing obstacle for the development of nonlive RSV vaccine candidates. The findings presented here underscore the need to evaluate a nonlive RSV vaccine candidate during preclinical development over a wide dose range in the cotton rat RSV enhanced-disease model, as suboptimal dosing of several RSV F subunit vaccine candidates led to the priming for ERD. These observations are relevant to the validity of the cotton rat model itself and to safe development of nonlive RSV vaccines for seronegative infants and children.

Postnatal human enteric neuronal progenitors can migrate, differentiate, and proliferate in embryonic and postnatal aganglionic gut environments.

BACKGROUND: Enteric neural stem/progenitor cells (ENSCs) offer an innovative approach to treating Hirschsprung disease (HSCR) and other enteric neuropathies. However, postnatal-derived human ENSCs have not been thoroughly characterized and their behavior in the embryonic and postnatal intestinal environment is unknown. METHODS: ENSCs were isolated from the intestines of 25 patients undergoing bowel resection, including 7 children with HSCR. Neuronal differentiation and proliferation of ENSCs from submucosal and myenteric plexuses from patients with and without HSCR were characterized. ENSC migration and differentiation were studied following transplantation into embryonic chick neural crest, embryonic chick hindgut, and postnatal mouse aganglionic colon. RESULTS: The proliferative and neurogenic potential of ENSCs from HSCR intestine is equivalent to that of non-HSCR controls. Similarly, no difference was observed between myenteric- and submucosal-derived ENSCs. Postnatal ENSCs transplanted to embryonic neural crest pathways and to aneural hindgut migrate normally and differentiate into appropriate neural crest-derived cell types. ENSCs in postnatal mouse aganglionic colon differentiate into neurons and glia both ex vivo and in vivo. CONCLUSIONS: ENSCs isolated from the postnatal intestine of patients with and without HSCR can behave like embryonic neural crest-derived cells. These results support the feasibility of cell-based therapy for future treatment of neurointestinal disease.