Herpes Simplex Virus type 1 infects Langerhans cells and the novel epidermal dendritic cell, Epi-cDC2s, via different entry pathways.

Skin mononuclear phagocytes (MNPs) provide the first interactions of invading viruses with the immune system. In addition to Langerhans cells (LCs), we recently described a second epidermal MNP population, Epi-cDC2s, in human anogenital epidermis that is closely related to dermal conventional dendritic cells type 2 (cDC2) and can be preferentially infected by HIV. Here we show that in epidermal explants topically infected with herpes simplex virus (HSV-1), both LCs and Epi-cDC2s interact with HSV-1 particles and infected keratinocytes. Isolated Epi-cDC2s support higher levels of infection than LCs in vitro, inhibited by acyclovir, but both MNP subtypes express similar levels of the HSV entry receptors nectin-1 and HVEM, and show similar levels of initial uptake. Using inhibitors of endosomal acidification, actin and cholesterol, we found that HSV-1 utilises different entry pathways in each cell type. HSV-1 predominantly infects LCs, and monocyte-derived MNPs, via a pH-dependent pathway. In contrast, Epi-cDC2s are mainly infected via a pH-independent pathway which may contribute to the enhanced infection of Epi-cDC2s. Both cells underwent apoptosis suggesting that Epi-cDC2s may follow the same dermal migration and uptake by dermal MNPs that we have previously shown for LCs. Thus, we hypothesize that the uptake of HSV and infection of Epi-cDC2s will stimulate immune responses via a different pathway to LCs, which in future may help guide HSV vaccine development and adjuvant targeting.

Aganglionosis with the absence of hypertrophied nerve fibres predicts disease proximal to rectosigmoid colon.

PURPOSE: The gold standard for the diagnosis of Hirschsprung's disease (HSCR) is the pathologic evaluation of a rectal biopsy that demonstrates the absence of ganglion cells and nerve fibre hypertrophy. However, it has been frequently reported that hypertrophic nerves may not be present in some variants like long-segment HSCR, total colonic aganglionosis, premature and very young infants. The aim of this study was to determine this association. METHODS: We performed a retrospective review of the HSCR database at our tertiary care children's hospital from 2000 to 2013. In order to analyse the relationship between the diameter of the nerve fibres and the level of aganglionosis, we classified the patient sample into two groups-fibres ≤40 and >40 µm. The groups were statistically compared with P < 0.05 being significant. RESULTS: Rectal biopsies of 92 patients confirmed as HSCR with definitive operation performed at the same institution were reviewed. The mean nerve diameter was 50.1 µm (range 20-87.5 µm). Nerve fibre diameter ≤40 µm was predictive of transition zone above the sigmoid colon. A specificity of 77.3 % and a likelihood ratio of 2.03 supported this perception. No correlation was noted between nerve fibre diameter and gestational age at birth, birth weight or age at biopsy. CONCLUSION: The absence of nerve fibre hypertrophy in the presence of aganglionosis on rectal biopsy specimens is predictive of long-segment HSCR.

Relay of herpes simplex virus between Langerhans cells and dermal dendritic cells in human skin.

The mechanism by which immunity to Herpes Simplex Virus (HSV) is initiated is not completely defined. HSV initially infects mucosal epidermis prior to entering nerve endings. In mice, epidermal Langerhans cells (LCs) are the first dendritic cells (DCs) to encounter HSV, but it is CD103(+) dermal DCs that carry viral antigen to lymph nodes for antigen presentation, suggesting DC cross-talk in skin. In this study, we compared topically HSV-1 infected human foreskin explants with biopsies of initial human genital herpes lesions to show LCs are initially infected then emigrate into the dermis. Here, LCs bearing markers of maturation and apoptosis formed large cell clusters with BDCA3(+) dermal DCs (thought to be equivalent to murine CD103(+) dermal DCs) and DC-SIGN(+) DCs/macrophages. HSV-expressing LC fragments were observed inside the dermal DCs/macrophages and the BDCA3(+) dermal DCs had up-regulated a damaged cell uptake receptor CLEC9A. No other infected epidermal cells interacted with dermal DCs. Correspondingly, LCs isolated from human skin and infected with HSV-1 in vitro also underwent apoptosis and were taken up by similarly isolated BDCA3(+) dermal DCs and DC-SIGN(+) cells. Thus, we conclude a viral antigen relay takes place where HSV infected LCs undergo apoptosis and are taken up by dermal DCs for subsequent antigen presentation. This provides a rationale for targeting these cells with mucosal or perhaps intradermal HSV immunization.

Adjunct ultrasonography in children with suspected acute appendicitis: identifying the optimal target group.

BACKGROUND: Role of ultrasonography in diagnosis of acute appendicitis in children is being debated. This study was conducted ahead of a clinical trial and aimed to evaluate the adjunctive role of ultrasonography in this group. METHODS: Retrospective chart review of consecutive children undergoing appendicectomy in an Australian tertiary children's hospital over 24 months. Two study groups were: clinical assessment and clinical assessment plus ultrasonography. The accuracy of diagnosis was compared by generating estimates for sensitivity and positive predictive value using histopathology of the appendix as the reference standard. The incremental value of ultrasonography was evaluated in subgroups of gender, age and clinical severity. RESULTS: Two hundred ninety-five children (170 boys, median age 10 years) were included in the study. Negative appendicectomy rate was 17.3%; 10.4% in the clinical assessment group (n = 134) and 23% in the ultrasonography group (n = 161). Overall sensitivity for diagnosis by clinical assessment (71.4%, 95% confidence interval (CI) 63.3-79.5) was not significantly different to that using adjunct ultrasonography (77.7%, 95% CI 69.7-85.7; P = 0.29). Adjunct ultrasonography was more sensitive between 7 and 11 years (81% versus 68%, P = 0.002) and possibly in girls (86% versus 73%, P = 0.1), but did not increase the sensitivity of the diagnosis in children who presented with milder symptoms and signs. CONCLUSIONS: Adjunct ultrasonography may not increase the overall accuracy of diagnosis of acute appendicitis in children but holds promise in certain subgroups viz. between 7 and 11 years and in girls. There is an increase in negative appendicectomies following a 'non-targeted' use of ultrasonography. Future prospective trials should take cognizance of these findings in designing the subgroup analysis.

Porcine models for pediatric minimally invasive surgical training--a template for the future.

Pediatric minimally invasive surgery is a rapidly developing field with a steep learning curve for each new procedure that is developed and integrated into practice. The European consensus is that the training across the learning curve should not be on the patients. Simulation is a widely accepted methodology to shorten the learning curve. Training on animal models is an advanced form of simulation. This helps to reduce morbidity and the costs of patient care. This article describes our 3 years of experience in the development of animal models for training in pediatric minimally invasive surgery.

Impact of minimally invasive surgery on the pediatric surgical profession.

We conducted a survey among pediatric surgeons to examine the impact of the advent of minimally invasive surgery (MIS) on the pediatric surgical profession with respect to job satisfaction and training challenges. An invitation to participate in a web-based questionnaire was sent out to 306 pediatric surgeons. Apart from demographic details and training recommendations, parameters relevant to job satisfaction, including patient interaction, peer pressure, ethical considerations, academic progress, ability to train residents, and financial remuneration, were studied. The response rate was 38.2%. Working in a unit performing MIS was identified by 71% of respondents as the most effective and feasible modality of training in MIS. Inability to get away from a busy practice was the most common reason cited for inability to acquire MIS training. The overall responses to the job satisfaction parameters showed a positive trend in the current MIS era for patient interaction, ethical considerations, academic progress, and training residents, with a negative trend for peer pressure and financial remuneration. The enthusiastic minimally invasive surgeons (EMIS) were defined as those having more than 5 years of MIS experience and also performing more than 10% of their work using MIS. Of the 113 responses analyzed, 67 belonged to the EMIS category. Those belonging to the EMIS group were less likely to feel inadequate in training their residents, in meeting the felt needs of the patients, or to complain about peer pressure. They were more likely to consider MIS to be as relevant and beneficial in children as in adults. Embracing MIS, as represented by the EMIS group, correlated with an overall greater job satisfaction.

Two decades of minimally invasive pediatric surgery-taking stock.

BACKGROUND: The past 2 decades have seen a rapid integration of minimally invasive surgery (MIS) to pediatric surgical practice. This study endeavored to delineate the current status of MIS in pediatric surgery. METHODS: Three hundred six pediatric surgeons were invited to participate in an anonymous Web-based survey. Apart from demographic details and opinion regarding robotic surgery, surgeons were asked to choose between "perform MIS," "do not perform MIS but recommend it," and "MIS not indicated" for common pediatric surgical conditions. RESULTS: Responses were received from 117 pediatric surgeons (38.2%). Sixty-one percent of respondents did more than 10% of their work using MIS, and 85% had more than 5 years experience in MIS. Cholecystectomy, nonpalpable testis, and exploration for abdominal pain scored highest among the positive recommendations for MIS, whereas liver tumors, biliary atresia, Wilms' tumor, and inguinal hernia scored highest among the negative recommendations for MIS. Fifty-one percent of the respondents had more than 20 years experience as a pediatric surgeon and were categorized as "senior" surgeons. Compared with the young surgeons, the senior surgeons were more likely to recommend MIS as a contraindication for simple and complicated appendicitis, reduction of intussusception, gastrostomy, fundoplication, pyloromyotomy, adhesiolysis, splenectomy, adrenalectomy, nephrectomy for dysplastic kidneys, heminephrectomy, pyeloplasty, anorectal malformations, pyeloplasty, achalasia cardia, hiatal hernia repair, lung resection, and diaphragmatic hernia repair. More than half the respondents believed that robotic surgery has a role for children in the future. CONCLUSIONS: A widespread integration of MIS into the pediatric surgical practice is evident from this study. Current practice and recommendations of the surveyed surgeons have been outlined. Significant differences between the young and senior surgeons reflect the evolving nature of the recommendations.

An optimum animal model for neonatal thoracoscopy.

PURPOSE: This study attempted to define an optimum animal model for neonatal thoracoscopy. MATERIALS AND METHODS: Seven rabbits and three 5-7-kg piglets were subjected to thoracoscopy by three pediatric surgeons. The outcome for the successful completion of esophageal anastomosis and additional procedures, including diaphragmatic plication and lung biopsy, were noted. RESULTS: Whereas esophageal anastomosis could be accomplished in all piglets, it could be achieved in only 1 rabbit. Additional procedures were possible in 2 piglets and no rabbits. Anesthetic complications were seen in 4 rabbits and 1 piglet. CONCLUSION: Our findings suggest that the piglet may be the optimum animal model for replicating neonatal thoracoscopy. The fragility of the rabbit, coupled with a limited intrathoracic working space, limits its use for thoracoscopy.

What causes intrathoracic gastric dilatation in a late-presenting diaphragmatic hernia?

A 13-year-old previously asymptomatic patient presented with abdominal pain and vomiting. Chest radiogram revealed a left intrathoracic stomach. Laparotomy confirmed a dilated, hypertrophic stomach herniating through a left Bochdalek hernia. The patient recovered after a period of prolonged gastric paresis. While highlighting the importance of considering this condition in the differential diagnosis of a cystic lesion in the chest, this article also postulates a mechanism for the hypertrophic gastric dilatation in a late presentation of a congenital diaphragmatic hernia.

An eighteen year follow-up after surgery for congenital microgastria--case report and review of literature.

Congenital microgastria is a rare disorder with only 59 previously reported cases in the literature. The best results are achieved by definitive surgery in the form of a Hunt-Lawrence (HL) jejunal pouch for gastric augmentation. Only 12 patients have previously undergone a HL pouch for microgastria. Long-term results after a HL pouch are not well known. We report a patient who underwent a HL pouch 18 years ago, now having a good quality of life and eating normal meals, though having a suboptimal somatic growth. It is likely that long-term results can be optimized by early gastric augmentation with a HL pouch.

Posttraumatic small bowel obstruction in children.

BACKGROUND: The diagnosis of intestinal injuries in children after blunt abdominal trauma can be difficult and delayed. Most children who suffer blunt abdominal trauma are managed nonoperatively, making the diagnosis of intestinal injuries more difficult. We sought to gain information about children who develop intestinal obstruction after blunt abdominal trauma by reviewing our experience. METHODS: Review of records from a pediatric tertiary care center over an 11.5-year period revealed 5 patients who developed small bowel obstruction after blunt trauma to the abdomen. The details of these patients were studied. RESULTS: All patients were previously managed nonoperatively for blunt abdominal trauma. Intestinal obstruction developed 2 weeks to 1 year (median, 21 days) after the trauma. Abdominal x-ray, computerized tomography scan, or barium meal studies were used to establish the diagnosis. The pathology was either a stricture, an old perforation, or adhesions causing the intestinal obstruction. Laparotomy with resection and anastomosis was curative. CONCLUSIONS: Posttraumatic small bowel obstruction is a clinical entity that needs to be watched for in all patients managed nonoperatively for blunt abdominal trauma.

Atypical congenital mesoblastic nephroma presenting in the perinatal period.

Congenital mesoblastic nephroma (CMN) is a rare tumour of infancy having an overall good prognosis. The less common, atypical CMNs have cellular elements in them and tend to have an unpredictable course. Occurrence in the perinatal period may further change the outcome. By reporting three patients presenting in the perinatal period with atypical CMN, an attempt is made in this paper to characterize the clinical behaviour of these variant tumours. Though one of our patients had an uneventful course, the other two had several complications including polyhydramnios, prematurity, hypertension, haemodynamic instability and tumour spillage. The course was complicated by recurrence in the latter two and refractoriness to chemotherapy and death in one. That the atypical subset of CMNs occurring in the perinatal period can have a stormy course is well illustrated by this report. Possible prognostic factors are evaluated and the sparse reports of similar cases in the literature are reviewed and compared.