A Critical Analysis of Rectal Biopsy to Exclude Hirschsprung's Disease

INTRODUCTION

 Most Hirschsprung's disease (HD) are diagnosed in young children with increased risk ("red flag"). Older children (>6 months) require open rectal biopsy (ORB) with its own impact on risk and resources. We investigated if "red flag", age, and sex used in combination could exclude HD.

MATERIALS AND METHODS

 "Red flags" are risk factors associated with HD, including neonatal bowel obstruction, genetic association, failure of passage of meconium in <48 hours, infantile constipation, distension with vomiting, or family history. All rectal biopsies (2015-2018) were reviewed for indications, methods, and histopathological findings. Logistic regression analysis was adopted to assess predictive value of "red flag," age, and sex (p < 0.05* was significant).

RESULTS

 A total of 187 children underwent 84 suction rectal biopsies and 113 ORBs (n = 197 in total). Final histopathological diagnoses were non-HD (n = 154) and HD (n = 43). Total 78% of rectal biopsies were non-HD, of which 63% by ORB. Non-HD was associated with absence of "red flag" (49 vs. 16%*), increased age at biopsy (22 months vs. 28 days*), >6 months old (62 vs. 30%*), and female gender (54 vs. 16%*), compared with HD. In the absence of "red flag," 7/82 (9%) had HD (negative predictive value = 91%). Logistic regression analysis found absent "red flag" predicted non-HD biopsy with odds ratio 4.77 (1.38, 16.47), corrected for age and sex.

CONCLUSION

 Negative rectal biopsy rate for HD is very high. The majority required ORB. Although "red flag" and gender, but not age, have strong predictive values, it is inadequate for excluding HD. This study supports the need for alternative strategies in excluding HD.

Charismatic Nonverbal Displays by Leaders Signal Receptivity and Formidability, and Tap Approach and Avoidance Motivational Systems

Status cues and signals act as guidance systems by regulating social approach and avoidance. Applied to leadership, we hypothesized that nonverbal displays conveying the dual-status messages of receptivity and formidability and the approach/avoidance motives they activate set conditions for charismatic, leader–follower relationships. We investigated perceptions of charisma, the nonverbal signals associated with them, the motives they energize, and the relationships they support across levels of analysis. At the social–perceptual level (studies 1a–d), eligible voters rated political leaders’ traits after viewing silent, 30-s videos of speeches presented online. As predicted, perceptions of politicians’ receptivity (warmth and attractiveness) and formidability (competence and power) were independently associated with perceptions of their charisma; perceptions of trustworthiness and authenticity showed weaker or negligible associations. Results were similar when the stimuli were female, Jamaican educational leaders. Leaders’ nonverbal behavior was linked to perceptions of their receptivity, formidability, and charisma in study 2. At the brain systems level, studies 3a and 3b tested predictions that charismatic nonverbal performances stimulate equivalent degrees of approach and avoidance motivation in observers. Brain recordings via electroencephalography (EEG) were made while undergraduates viewed leaders rated high or low in charisma. Discrepancies in alpha activity in the left and the right frontal hemispheres (associated with approach and avoidance, respectively) were relatively diminished when participants viewed highly charismatic political leaders, indicating that approach and avoidance motives are energized in response to charismatic performances. The EEG patterns for Jamaican leaders were similar but not significant. At the group level of analysis, study 4 sought evidence that charismatic leaders create uniquely influential relationships with followers. Video recordings of student leaders interacting with pairs of unfamiliar students during a group decision-making task were assessed for leader receptivity, formidability, and charisma by independent sets of undergraduate judges. Perceptions of student leaders’ receptivity and formidability predicted their charisma, and charismatic leaders were most influential in bringing followers to privately accept a controversial group decision. Across studies, evidence generally supported hypotheses generated from status cues theory: charismatic leadership builds upon the nonverbal projection of dual-status messages and the approach/avoidance motives they engender, setting conditions for a uniquely powerful brand of influence.

Neonatal Appendicitis and Incarcerated Inguinal Hernia: Case Report and Review of the Literature

Neonatal appendicitis carries a high mortality rate. We describe a peculiar case presented after an incarcerated hernia manually reduced in a 4-week-old male neonate with ipsilateral undescended testis. Laparoscopy allowed a prompt recognition of an unexpected intra-abdominal life-threatening condition. Pathogenesis, treatment, and outcome are discussed on the light of a comprehensive literature review.

High Yield Polycarbosilane Precursors to Stoichiometric SiC. Synthesis, Pyrolysis and Application

The synthesis and properties of two polycarbosilanes that have essentially a “SiH2CH2” composition is described. One of these polymers is a highly branched hydridopolycarbosilane (HPCS) derived from Grignard coupling of CI3SiCH2CI followed by LiAIH4 reduction. This synthesis is amenable to large scale production and we are exploring applications of HPCS as a source of SiC coatings and its allyl-derivative, AHPCS, as a matrix source for SiC- and C-fiber-reinforced composites. These polymers thermoset on heating at 200-400 °C (or at 100 °C with a catalyst) and give near stoichiometric SiC with low O content in ca. 80% yield on pyrolysis to 1000 °C. The second method involves ring-opening polymerization of 1,1,3,3-tetrachlorodisilacyclobutane and yields a high molecular weight, linear polymer that can be reduced to [SiH2CH2]n (PSE), the monosilicon analog of polyethylene. In contrast to high density polyethylene which melts at 135 °C, PSE is a liquid at room temperature which crystallizes at ca. 5 °C. On pyrolysis to 1000 °C, PSE gives stoichiometric, nanocrystalline, SiC in virtually quantitative yield. The polymer-to-ceramic conversion was examined for PSE by using TGA, mass spec, solid state NMR, and IR methods yielding information regarding the cross-linking and structural evolution processes. The results of these studies of the polymer-to-ceramic conversion process and our efforts to employ the AHPCS polymer as a source of SiC matrices are described.

Fabrication of Sic Matrix Composites by Liquid Phase Infiltration with a Polymeric Precursor

A process for the fabrication of SiC matrix composites has been developed which employs aliquid, highly branched, polycarbosilane (AHPCS). This polymer thermosets on heating at 200-400 °C (or at 100 °C with catalyst) and yields an amorphous SiC with low excess C and O content in 60-80% yield on pyrolysis to 1000 °C. Preforms consisting of C-coated Nicalon SiC fiber cloth, unidirectional Textron SiC SCS-6 fiber layups, or Mo boats packed with SiC whiskers, were infiltrated with the polymer, cured in an autoclave, and pyrolyzed to 1000 °C. Five to eight infiltration cycles gave net shape composites with final densities at 85-94 % of theoretical. The results of 4-point flexure tests on the as-prepared Nicalon composites indicate flexure strengths (aver. 378 MPa) that are comparable to or better than similarly reinforced CVI-SiC matrix composites. The whisker and SCS-6 composites showed a small weight loss (10-20%) on heating to 1500 °C in Ar and little or no weight change or obvious embrittlement in air at 1000 °C.

Challenges in the prenatal and post-natal diagnosis of mediastinal cystic hygroma: a case report

INTRODUCTION

Cystic hygroma is a benign congenital neoplasm that mostly presents as a soft-tissue mass in the posterior triangle of the neck. Pure mediastinal lesions are uncommon; the vast majority are asymptomatic and are an incidental finding in adulthood. The diagnosis is often made intra- or postoperatively. Prenatal identification is exceptional and post-natal diagnosis also proves challenging.

CASE PRESENTATION

We report one such case that was mistaken for other entities in both the prenatal and immediate post-natal period. Initial and follow-up antenatal ultrasound scans demonstrated a multicystic lesion in the left chest, and the mother was counselled about the possibility of her baby having a congenital diaphragmatic hernia. Initial post-natal chest radiographs were reported as normal. An echocardiogram and thoracic computed tomography scan confirmed a complex multiloculated cystic mediastinal mass. The working diagnoses were of a mediastinal teratoma or congenital cystic adenomatous malformation. At operation, the lesion was compressed by the left lung and was found to be close to the left phrenic nerve, which was carefully identified and preserved. After excision, histopathological examination of the mass confirmed the diagnosis of cystic hygroma. Postoperative dyspnoea was observed secondary to paradoxical movement of the left hemidiaphragm and probable left phrenic neuropraxia. This settled conservatively with excellent recovery.

CONCLUSION

Despite the fact that isolated intrathoracic cystic hygroma is a rare entity, it needs to be considered in the differential diagnosis of foetal and neonatal mediastinal masses, particularly for juxtadiaphragmatic lesions. The phrenic nerve is not identifiable on prenatal ultrasound imaging, and it is therefore understandable that a mass close to the diaphragm may be mistaken for a congenital diaphragmatic hernia because of the location, morphology and potential phrenic nerve compression. Post-natal diagnosis may also be misleading as many mediastinal cystic masses have similar appearances on imaging. Therefore, as well as cystic architecture, special consideration needs to be given to the anatomical location and effect on local structures.

Postnatal outcome of antenatally diagnosed intra-abdominal cysts

The aim of this study is to establish the postnatal diagnosis and outcome of all abdominal cystic lesions diagnosed antenatally over a 13-year period. All prenatally suspected and postnatally confirmed intra-abdominal cysts seen and delivered between 1991 and 2004 were identified. Antenatal diagnosis, gestational age at delivery, sex and postnatal diagnosis and outcome were recorded. Fifty-five patients were identified with an antenatal diagnosis of abdominal cystic lesion. There were 53 live births and 2 intrauterine deaths. In 13 cases (24%) the cyst had resolved on a postnatal scan. Sixteen (29%) required surgical intervention postnatally. Twenty-six (47%) were given a "non-specific" diagnosis of abdominal cyst antenatally. Three (11%) of these non-specific cysts had resolved on postnatal scan. A "specific" diagnosis of the abdominal cyst was made antenatally in 29 cases (53%) of which 12 (43%) had the diagnosis confirmed postnatally. In ten (35%) of these there was a normal postnatal scan. Antenatal ultrasound scans may not reliably predict the exact pathological diagnosis of abdominal cystic lesions. However this study provides valuable information on the proportion of correctly diagnosed lesions and those that will persist into the postnatal period allowing more informative counselling for prospective parents.

Multidisciplinary approach to expansion thoracoplasty for congenital spinal deformity: a preliminary report

BACKGROUND

In children with congenital chest wall deformities, the vertical expandable prosthetic titanium Rib (VEPTR) has recently been developed to move the emphasis away from corrective spinal fusion, to expanding the deformed hemithorax. The aim of this paper is to demonstrate the need for paediatric surgeons in what is primarily an orthopaedic procedure.

MATERIALS AND METHODS

All patients less than 5 years old who had primary congenital scoliosis with poor respiratory function and were treated by VEPTR at our institution in conjunction with the spinal orthopaedic surgeons were reviewed.

RESULTS

All 6 cases required rib exposure and thoracostomy by a paediatric surgeon. One required exposure of the ribs only, 3 required an extrapleural thoracotomy and 2 required intrapleural thoracotomy with a patch repair of the rib space. None of the patients required blood transfusion and there were no early complications. All patients showed radiological improvement of their spinal and thoracic deformity as well as improvement in their respiratory function.

CONCLUSION

Paediatric surgeons play an important role in the thoracic exposure required for this orthopaedic procedure. The benefit of a multidisciplinary approach is highlighted in this paper. The VEPTR implant may replace major spinal fusion surgery in this challenging group of patients.

Rectal adenocarcinoma following cranio-spinal radiotherapy for cerebellar medulloblastoma

The authors present a case of a 16-year-old female diagnosed with rectal adenocarcinoma 10 years after receiving cranio-spinal radiotherapy for a cerebellar medulloblastoma. While the risk of a second malignancy is recognised to be increased in children previously treated with radiotherapy, rectal adenocarcinoma is a rare presentation. A child presenting with symptoms of weight loss and a change in bowel habit in a patient who has previously received radiotherapy should alert practitioners to the possibility of a colorectal malignancy.

Fibroepithelial polyps causing ureteropelvic junction obstruction in children--a case report and review article

Fibroepithelial polyps are extremely rare benign mesodermal tumours in children that can cause ureteropelvic junction (UPJ) obstruction. We report on a 10-year-old boy presenting with UPJ obstruction due to a fibroepithelial polyp, and review 28 similar published paediatric cases.

Infantile hypertrophic pyloric stenosis: an infectious cause?

The aetiology of infantile hypertrophic pyloric stenosis (IHPS) remains unclear. The aim of this study was to test the hypothesis that a common bacterium, Helicobacter pylori (HP) may be implicated in the pathogenesis of IHPS. Thirty-nine consecutive infants with confirmed IHPS had their stool analysed with an enzyme immunoassay for the presence of HP. An age/sex-matched group of infants with unrelated surgical conditions were also tested. No positive results for the presence of HP stool antigen were obtained in the study nor the control group. The results of this study demonstrate no causative link between HP and IHPS. A genetic basis has been implicated for IHPS. However, evidence does exist that IHPS is a condition acquired after birth and that an infective agent may be involved in the pathogenesis. Further studies are required to elucidate perinatal factors that may induce the expression of this condition in a genetically sensitive individual.

Somatostatin for intractable postoperative chylothorax in a premature infant

A premature infant of 31 weeks' gestation underwent repair of an oesophageal atresia, distal tracheo-oesophageal fistula and anal stenosis. A lymphatic leak was noted at the time of surgery. Chylous drainage persisted and an intravenous infusion of somatostatin was begun. The volume of chyle drained fell dramatically within the first 24 h and was negligible by the 5th day of treatment. No reaccumulation of the chylothorax was seen after the cessation of somatostatin. To our knowledge this is the youngest reported child in whom somatostatin has been used successfully in treating a postoperative chylothorax.

Provision of HPA-1a (PlA1)-negative platelets for neonatal alloimmune thrombocytopenia: screening, testing, and transfusion protocol

HPA-1a-negative platelet products are not routinely available for newborns with alloimmune thrombocytopenia. In this article we describe a program established to identify normal pheresis donors who are HPA-1a-negative and to organize their future donations so that our regional blood center would always have an HPA-1a-negative platelet product available. The solid phase red cell adherence assay was used for initial screening of platelet pheresis products. HPA-1a-negative donors were confirmed with the platelet suspension immunofluorescence test using three anti-HPA-1a sera. Screening of 2600 plateletpheresis donor samples identified 40 HPA-1a-negative donors. Of these, 36 are active and are coded for recognition on the daily pheresis inventory sheet. Theoretically, assuming four donations per year and donors' cooperation with scheduling, these 36 donors would enable us to have at least one HPA-1a-negative product available every day. In addition, a decision tree for patient management using platelet serology and availability of HPA-1a-negative products was developed. The GTI-PAK trade mark 12 is the major technique used for serologic screening of mothers of patients thought to have neonatal alloimmune thrombocytopenia. By screening pheresis donors and developing a clinical decision tree, HPA-1a-negative products, a rare resource, can be fully utilized.