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Controversy persists regarding the ideal surgical approach for repair of esophageal atresia with tracheoesophageal fistula (EA/TEF). We examined complications and outcomes of infants undergoing thoracoscopy and thoracotomy for repair of Type C EA/TEF using propensity score-based overlap weights to minimize the effects of selection bias.Secondary analysis of two databases from multicenter retrospective and prospective studies examining outcomes of infants with proximal EA and distal TEF who underwent repair at 11 institutions was performed based on surgical approach. Regression analysis using propensity score-based overlap weights was utilized to evaluate outcomes of patients undergoing thoracotomy or thoracoscopy for Type C EA/TEF repair.Of 504 patients included, 448 (89%) underwent thoracotomy and 56 (11%) thoracoscopy. Patients undergoing thoracoscopy were more likely to be full term (37.9 vs. 36.3 weeks estimated gestational age, p 0.001), have a higher weight at operative repair (2.9 vs. 2.6 kg, p 0.001), and less likely to have congenital heart disease (16% vs. 39%, p 0.001). Postoperative stricture rate did not differ by approach, 29 (52%) thoracoscopy and 198 (44%) thoracotomy (p = 0.42). Similarly, there was no significant difference in time from surgery to stricture formation (p 0.26). Regression analysis using propensity score-based overlap weighting found no significant difference in the odds of vocal cord paresis or paralysis (OR 1.087 p = 0.885), odds of anastomotic leak (OR 1.683 p = 0.123), the hazard of time to anastomotic stricture (HR 1.204 p = 0.378), or the number of dilations (IRR 1.182 p = 0.519) between thoracoscopy and thoracotomy.Infants undergoing thoracoscopic repair of Type C EA/TEF are more commonly full term, with higher weight at repair, and without congenital heart disease as compared to infants repaired via thoracotomy. Utilizing propensity score-based overlap weighting to minimize the effects of selection bias, we found no significant difference in complications based on surgical approach. However, our study may be underpowered to detect such outcome differences owing to the small number of infants undergoing thoracoscopic repair.Level III.

Anastomotic stricture is the most common complication after esophageal atresia (EA) repair. We sought to determine if postoperative acid suppression is associated with reduced stricture formation.A prospective, multi-institutional cohort study of infants undergoing primary EA repair from 2016 to 2020 was performed. Landmark analysis and multivariate Cox regression were used to explore if initial duration of acid suppression was associated with stricture formation at hospital discharge (DC), 3-, 6-, and 9-months postoperatively.Of 156 patients, 79 (51%) developed strictures and 60 (76%) strictures occurred within three months following repair. Acid suppression was used in 141 patients (90%). Landmark analysis showed acid suppression was not associated with reduction in initial stricture formation at DC, 3-, 6- and 9-months, respectively (p = 0.19-0.95). Multivariate regression demonstrated use of a transanastomotic tube was significantly associated with stricture formation at DC (Hazard Ratio (HR) = 2.21 (95% CI 1.24-3.95, p0.01) and 3-months (HR 5.31, 95% CI 1.65-17.16, p0.01). There was no association between acid suppression duration and stricture formation.No association between the duration of postoperative acid suppression and anastomotic stricture was observed. Transanastomotic tube use increased the risk of anastomotic strictures at hospital discharge and 3 months after repair.

Objective The purpose of this study was to evaluate the safety of a water-soluble contrast challenge as part of a nonoperative management algorithm in children with an adhesive small bowel obstruction (ASBO). Background Predicting which children will successfully resolve their ASBO with non-operative management at the time of admission remains difficult. Additionally, the safety of a water-soluble contrast challenge for children with ASBO has not been established in the literature. Methods A retrospective review was performed of patients who underwent non-operative management for an ASBO and received a contrast challenge across 5 children's hospitals between 2012 and 2020. Safety was assessed by comparing the complication rate associated with a contrast challenge against a pre-specified maximum acceptable level of 5%. Sensitivity, specificity, negative (NPV) and positive (PPV) predictive values of a contrast challenge to identify successful nonoperative management were calculated. Results Of 82 children who received a contrast challenge, 65% were successfully managed nonoperatively. The most common surgical indications were failure of the contrast challenge or failure to progress after initially passing the contrast challenge. There were no complications related to contrast administration (0%; 95% confidence interval: 0-3.6%, P = 0.03). The contrast challenge was highly reliable in determining which patients would require surgery and which could be successfully managed non-operatively (sensitivity 100%, specificity 86%, NPV 100%, PPV 93%). Conclusion A contrast challenge is safe in children with ASBO and has a high predictive value to assist in clinical decision-making.

Background Management of ovarian torsion has evolved toward ovarian preservation regardless of ovarian appearance during surgery. However, patients with torsion and an ovarian neoplasm undergo a disproportionately high rate of oophorectomy. Our objectives were to identify factors associated with ovarian torsion among females with an ovarian mass and to determine if torsion is associated with malignancy. Methods A retrospective review of females aged 2-21 y who underwent an operation for an ovarian cyst or neoplasm between 2010 and 2016 at 10 children's hospitals was performed. Multivariate logistic regression was used to assess factors associated with torsion. Imaging data were assessed for sensitivity, specificity, and predictive value in identifying ovarian torsion. Results Of 814 girls with an ovarian neoplasm, 180 (22%) had torsion. In risk-adjusted analyses, patients with a younger age, mass size >5 cm, abdominal pain, and vomiting had an increased likelihood of torsion (P 5 cm had two times the odds of torsion (odds ratio: 2.1; confidence interval: 1.2, 3.6). Imaging was not reliable at identifying torsion (sensitivity 34%, positive predictive value 49%) or excluding torsion (specificity 72%, negative predictive value 87%). The rates of malignancy were lower in those with an ovarian mass and torsion than those without torsion (10% versus 17%, P = 0.01). Among the 180 girls with torsion and a mass, 48% underwent oophorectomy of which 14% (n = 12) had a malignancy. Conclusions In females with an ovarian neoplasm, torsion is not associated with an increased risk of malignancy and ovarian preservation should be considered.

Introduction The purpose of this study was to develop a multi-institutional registry to characterize the demographics, management, and outcomes of a contemporary cohort of children undergoing congenital lung malformation (CLM) resection. Methods After central reliance IRB approval, a web-based, secure database was created to capture retrospective cohort data on pathologically-confirmed CLMs performed between 2009 and 2015 within a multi-institutional research collaborative. Results Eleven children's hospitals contributed 506 patients. Among 344 prenatally diagnosed lesions, the congenital pulmonary airway malformation volume ratio was measured in 49.1%, and fetal MRI was performed in 34.3%. One hundred thirty-four (26.7%) children had respiratory symptoms at birth. Fifty-eight (11.6%) underwent neonatal resection, 322 (64.1%) had surgery at 1–12 months, and 122 (24.3%) had operations after 12 months. The median age at resection was 6.7 months (interquartile range, 3.6–11.4). Among 230 elective lobectomies performed in asymptomatic patients, thoracoscopy was successfully utilized in 102 (44.3%), but there was substantial variation across centers. The most common lesions were congenital pulmonary airway malformation (n = 234, 47.3%) and intralobar bronchopulmonary sequestration (n = 106, 21.4%). Conclusion This multicenter cohort study on operative CLMs highlights marked disease heterogeneity and substantial practice variation in preoperative evaluation and operative management. Future registry studies are planned to help establish evidence-based guidelines to optimize the care of these patients. Level of evidence Level II.

OBJECTIVE To describe utilization and long-term outcomes of pneumonectomy in children and adolescents with cancer. SUMMARY BACKGROUND DATA Pneumonectomy in adults is associated with significant morbidity and mortality. Little is known about the indications and outcomes of pneumonectomy for pediatric tumors. METHODS The Pediatric Surgical Oncology Research Collaborative (PSORC) identified pediatric patients

Neonatal appendicitis is a rare disease with a high mortality rate. Appendicitis is difficult to diagnose in neonatal and infant populations because it mimics other more common conditions in these age groups. Furthermore, signs and symptoms of appendicitis are often nonspecific in nonverbal patients and a high index of suspicion is necessary to initiate the appropriate diagnostic work-up. The keys to successful management of appendicitis in infants include keeping the diagnosis on the differential in the setting of unexplained intra-abdominal sepsis, following a diagnostic algorithm in the work-up of infant abdominal pathology, and performing appendectomy once the diagnosis is confirmed.

Abdominal wall defects are common congenital anomalies with the most frequent being gastroschisis and omphalocele. Though both are the result of errors during embryologic development of the fetal abdominal wall, gastroschisis and omphalocele represent unique disorders that have different clinical sequelae. Gastroschisis is generally a solitary anomaly with postnatal outcomes related to the underlying integrity of the prolapsed bowel. In contrast, omphalocele is frequently associated with other structural anomalies or genetic syndromes that contribute more to postnatal outcomes than the omphalocele defect itself. Despite their embryological differences, both gastroschisis and omphalocele represent anomalies of fetal development that benefit from multidisciplinary and translational approaches to care, both pre- and postnatally. While definitive management of abdominal wall defects currently remains in the postnatal realm, advancements in prenatal diagnostics and therapies may one day change that. This review focuses on recent advancements, novel techniques, and current controversies related to the prenatal diagnosis and management of gastroschisis and omphalocele.

Simultaneous gastrostomy tube (GT) and tracheostomy placement in young children offers potential benefit in limiting anesthetic exposure, but it is unknown whether combining these procedures introduces additional morbidity. This study compared outcomes after combined GT and tracheostomy placement versus GT placement alone among similar ventilator-dependent patients.Ventilator-dependent children2-years-old who underwent GT placement alone (MV-GT), simultaneous GT and tracheostomy placement (GT+T), and GT placement alone with a pre-existing tracheostomy (T-GT) were identified using 2012-2018 NSQIP-Pediatric Participant User Files. Multiple logistic regression models were used to compare outcomes while adjusting for other group differences.Among 1100 children, 351 underwent MV-GT, 494 GT+T, and 255 T-GT. Major complications occurred in 23.6%, 17.0%, and 14.5% of the respective groups (p = 0.01). Major complications with GT+T were similar to T-GT (adjusted odds ratio [aOR]=1.19, 95%CI:0.78-1.83, p = 0.4) and lower than MV-GT (aOR=0.67, 95%CI:0.47-0.95, p = 0.02). Severe complications including mortality, cardiac arrest, and stroke were similar between the three groups (p = 0.8).Children2-years-old undergoing GT+T did not experience higher post-operative complications compared to children undergoing T-GT or MV-GT. Utilizing GT+T to limit anesthetic exposure may be reasonable within this high-risk population.Treatment Study LEVEL OF EVIDENCE: Level III.

Prior data suggest that infants with gastroschisis are at high risk for hypothermia and infectious complications (ICs). This study evaluated the associations between perioperative hypothermia (PH) and ICs in gastroschisis using a multi-institutional cohort.Retrospective review of infants with gastroschisis who underwent abdominal closure from 2013-2017 was performed at 7 children's hospitals. Any-IC and surgical site infection (SSI) were stratified against the presence or absence of PH, and perioperative characteristics associated with PH and SSI were determined using multivariable logistic regression.Of 256 gastroschisis neonates, 42% developed PH, with 18% classified as mild hypothermia (35.5-35.9 °C), 10.5% as moderate (35.0-35.4 °C), and 13% severe (35 °C). There were 82 (32%) ICs with 50 (19.5%) being SSIs. No associations between PH and any-IC (p = 0.7) or SSI (p = 0.98) were found. Pulmonary comorbidities (odds ratio (OR)=3.76, 95%CI:1.42-10, p = 0.008) and primary closure (OR=0.21, 95%CI:0.12-0.39, p0.001) were associated with PH, while silo placement (OR=2.62, 95%CI:1.1-6.3, p = 0.03) and prosthetic patch (OR=3.42, 95%CI:1.4-8.3, p = 0.007) were associated with SSI on multivariable logistic regression.Primary abdominal closure and pulmonary comorbidities are associated with PH in gastroschisis, however PH was not associated with increased risk of ICs. Independent risk factors for SSI include silo placement and prosthetic patch closure.

Purpose With the emergence of the coronavirus disease-2019 (COVID-19) pandemic, institutions were tasked with developing individualized pre-procedural testing strategies that allowed for re-initiation of elective procedures within national and state guidelines. This report describes the experience of a single US children’s hospital (Children’s Wisconsin, CW) in developing a universal pre-procedural COVID-19 testing protocol and reports early outcomes. Methods The CW pre-procedural COVID-19 response began with the creation of a multi-disciplinary taskforce that sought to develop a strategy for universal pre-procedural COVID-19 testing which (1) maximized patient safety, (2) prevented in-hospital viral transmission, (3) conserved resources, and (4) allowed for resumption of procedural care within institutional capacity. Results Of 11,209 general anesthetics performed at CW from March 16, 2020 to October 31, 2020, 11,150 patients (99.5%) underwent pre-procedural COVID-19 testing. Overall, 1.4% of pre-procedural patients tested positive for COVID-19. By June 2020, CW was operating at near-normal procedural volume and there were no documented cases of in-hospital viral transmission. Only 0.5% of procedures were performed under augmented COVID-19 precautions (negative pressure environment and highest-level personal protective equipment). Conclusion CW successfully developed a multi-disciplinary pre-procedural COVID-19 testing protocol that enabled resumption of near-normal procedural volume within three months while limiting in-hospital viral transmission and resource use.

Esophageal atresia with or without tracheoesophageal fistula is a congenital anomaly resulting from abnormal embryonic development of the foregut. It is frequently associated with other congenital anomalies and genetic syndromes, most commonly congenital heart disease. Prior to the advent of surgical repair in 1941, EA was a universally fatal diagnosis. Current management strategies have now improved survival of EA to over 90%. This chapter reviews the diagnostic workup, associated comorbidities, operative considerations, and common postoperative complications related to esophageal atresia with or without tracheoesophageal fistula.

This study evaluated compliance with a multi-institutional quality improvement management protocol for Type-C esophageal atresia with distal tracheoesophageal fistula (EA/TEF).Compliance and outcomes before and after implementation of a perioperative protocol bundle for infants undergoing Type-C EA/TEF repair were compared across 11 children's hospitals from 1/2016-1/2019. Bundle components included elimination of prosthetic material between tracheal and esophageal suture lines during repair, not leaving a transanastomotic tube at the conclusion of repair (NO-TUBE), obtaining an esophagram by postoperative-day-5, and discontinuing prophylactic antibiotics 24 h postoperatively.One-hundred seventy patients were included, 40% pre-protocol and 60% post-protocol. Bundle compliance increased 2.5-fold pre- to post-protocol from 17.6% to 44.1% (p 0.001). After stratifying by institutional compliance with all bundle components, 43.5% of patients were treated at low-compliance centers (20%), 43% at medium-compliance centers (20-80%), and 13.5% at high-compliance centers (80%). Rates of esophageal leak, anastomotic stricture, and time to full feeds did not differ between pre- and post-protocol cohorts, though there was an inverse correlation between NO-TUBE compliance and stricture rate over time (ρ = -0.75, p = 0.029).Compliance with our multi-institutional management protocol increased 2.5-fold over the study period without compromising safety or time to feeds and does not support the use of transanastomotic tubes.Level II.Treatment Study.

Complexity in movement planning, arising from diverse temporal and spatial sources, places a computational burden on the central nervous system. However, the efficacy with which humans can perform natural, highly trained movements suggests that they have evolved effective behavioral strategies that simplify the computational burden. The specific aim of our research was to use three-dimensional high-speed video to determine whether the tail nociceptive withdrawal response (NWR) to noxious heat stimuli delivered at locations that varied both circumferentially and rostral-caudally on the tail depended on the location of the stimulus in spinalized rats. In particular, we sought to determine whether the movement strategy was categorical (limited number of directions) or continuous (any variation in stimulus location results in a variation in response direction). In spinalized rats, localized, noxious heat stimuli were delivered at eight locations circumferentially around the tail and at five rostral-caudal levels. Our results demonstrate that at all rostral-caudal levels, response movement direction was bimodal regardless of circumferential stimulus location-either ~ 64° left or right of ventral. However, in spite of tight clustering, movement direction varied significantly but weakly according to circumferential location, in that responses to stimuli were more lateral for lateral stimulus locations. In contrast, changes in stimulus level strongly affected movement direction, in that a localized bend response closely matched the level of the stimulus. Together, our results demonstrate, based on movement analysis in spinalized rats, that the NWR employs a hybrid categorical-continuous strategy that may minimize the harmful consequences of noxious stimuli.

Purpose The purpose of this study was to determine the diagnostic accuracy of tumor markers for malignancy in girls with ovarian neoplasms. Methods A retrospective review of girls 2–21 years who presented for surgical management of an ovarian neoplasm across 10 children's hospitals between 2010 and 2016 was performed. Patients who had at least one concerning feature on imaging and had tumor marker testing were included in the study. Sensitivity, specificity, and negative and positive predictive values (PPV) of tumor markers were calculated. Results Our cohort included 401 patients; 22.4% had a malignancy. Testing for tumor markers was inconsistent. AFP had high specificity (98%) and low sensitivity (42%) with a PPV of 86%. The sensitivity, specificity, and PPV of beta-hCG was 44%, 76%, and 32%, respectively. LDH had high sensitivity (95%) and Inhibin A and Inhibin B had high specificity (97% and 92%, respectively). Conclusions Tumor marker testing is helpful in preoperative risk stratification of ovarian neoplasms for malignancy. Given the variety of potential tumor types, no single marker provides enough reliability, and therefore a panel of tumor marker testing is recommended if there is concern for malignancy. Prospective studies may help further elucidate the predictive value of tumor markers in a pediatric ovarian neoplasm population. Type of Study Retrospective Cohort Review. Level of Evidence Level III.

Ex Utero Intrapartum Treatment (EXIT) is a technique developed to safely and efficiently establish cardiopulmonary support at delivery while maintaining placental bypass. Indications for the EXIT approach are expanding and currently include EXIT-to-airway, EXIT-to-resection, EXIT-to-extracorporeal membrane oxygenation (ECMO), and EXIT-to-separation of conjoined twins. The EXIT technique involves planned partial delivery of the fetus via hysterotomy while maintaining uterine relaxation and placental support, allowing for the establishment of neonatal cardiopulmonary stability in a controlled manner. Fetal interventions performed during EXIT can include endotracheal intubation, tracheostomy, mass excision, removal of a temporary tracheal occlusive device, ECMO cannulation, and others. The most important aspect of an EXIT procedure is the formation of a multi-disciplinary team with broad expertise in fetal intervention to collaborate throughout the pre, intra, and post-partum periods. This chapter reviews the prenatal workup, decision making, surgical indications, and operative considerations associated with EXIT procedures.

BACKGROUND: Available evidence supports ovary-sparing surgery for benign ovarian neoplasms; however, preoperative risk stratification of pediatric ovarian masses can be difficult. Our objective of this study was to characterize the surgical management of pediatric ovarian neoplasms across 10 children’s hospitals and to identify factors that could potentially aid in the preoperative risk stratification of these lesions. METHODS: A retrospective review of girls and women aged 2 to 21 years who underwent surgery for an ovarian neoplasm between 2010 and 2016 at 10 children’s hospitals was performed. Multivariable logistic regression was used to examine the relationships between the preoperative cohort characteristics, procedure performed, and risk of malignancy. RESULTS: Among 819 girls and women undergoing surgery for an ovarian neoplasm, malignant lesions were identified in 11%. The overall oophorectomy rate for benign disease was 33% (range: 15%–49%) across institutions. Oophorectomy for benign lesions was independently associated with provider specialty (P = .002: adult gynecologist, 45%; pediatric surgeon, 32%; pediatric gynecologist, 18%), premenarchal status (P = .02), preoperative suspicion for malignancy (P < .0001), larger lesion size (P < .0001), and presence of solid components (P < .0001). Preoperative findings independently associated with malignancy included increasing size (P < .0001), solid components (P = .003), and age (P < .0001). CONCLUSIONS: The rate of oophorectomy for benign ovarian disease remains high within the pediatric population. Identification of factors associated with the choice of procedure and the risk of malignancy may allow for improved preoperative risk stratification and fewer unnecessary oophorectomies. These results have been used to develop and validate a multidisciplinary preoperative risk stratification algorithm that is currently being studied prospectively across 10 institutions.

The purpose of this study was to evaluate the clinical presentation and operative outcomes of patients with congenital lobar emphysema (CLE) within a large multicenter research consortium.After central reliance IRB-approval, a retrospective cohort study was performed on all operatively managed lung malformations at eleven participating children's hospitals (2009-2015).Fifty-three (10.5%) children with pathology-confirmed CLE were identified among 506 lung malformations. A lung mass was detected prenatally in 13 (24.5%) compared to 331 (73.1%) in non-CLE cases (p 0.0001). Thirty-two (60.4%) CLE patients presented with respiratory symptoms at birth compared to 102 (22.7%) in non-CLE (p 0.0001). The most common locations for CLE were the left upper (n = 24, 45.3%), right middle (n = 16, 30.2%), and right upper (n = 10, 18.9%) lobes. Eighteen (34.0%) had resection as neonates, 30 (56.6%) had surgery at 1-12 months of age, and five (9.4%) had resections after 12 months. Six (11.3%) underwent thoracoscopic excision. Median hospital length of stay was 5.0 days (interquartile range, 4.0-13.0).Among lung malformations, CLE is associated with several unique features, including a low prenatal detection rate, a predilection for the upper/middle lobes, and infrequent utilization of thoracoscopy. Although respiratory distress at birth is common, CLE often presents clinically in a delayed and more insidious fashion.Level III.

Oxytocin receptor (OXTR) acts as a key behavioral modulator of the central nervous system, affecting social behavior, stress, affiliation and cognitive functions. Variants of the Oxtr gene are known to influence behavior both in animals and humans; however, canine Oxtr polymorphisms are less characterized in terms of possible relevance to function, selection criteria in breeding and domestication. In this report, we provide a detailed characterization of common variants of the canine Oxtr gene. In particular (1) novel polymorphisms were identified by direct sequencing of wolf and dog samples, (2) allelic distributions and pairwise linkage disequilibrium patterns of several canine populations were compared, (3) neighbor joining (NJ) tree based on common single nucleotide polymorphisms (SNPs) was constructed, (4) mRNA expression features were assessed, (5) a novel splice variant was detected and (6) in vitro functional assays were performed. Results indicate marked differences regarding Oxtr variations between purebred dogs of different breeds, free-ranging dog populations, wolf subspecies and golden jackals. This, together with existence of explicitly dog-specific alleles and data obtained from the NJ tree implies that Oxtr could indeed have been a target gene during domestication and selection for human preferred aspects of temperament and social behavior. This assumption is further supported by the present observations on gene expression patterns within the brain and luciferase reporter experiments, providing a molecular level link between certain canine Oxtr polymorphisms and differences in nervous system function and behavior.

gamma-amino butyric acid (GABA) is the major inhibitory neurotransmitter in the CNS, mediating fast inhibitory synaptic transmission, by activating GABAA receptors. However, these GABA-gated Cl- channels can also be excitatory, causing depolarization, and increasing Ca2+ entry via voltage-operated Ca2+ channels (VOCCs). Evidence exists for excitatory ionotropic GABA receptors in anterior pituitary cells, including gonadotropes, but these have not been directly characterized and their pharmacology remains controversial. Here we have measured the cytosolic Ca2+ concentration ([Ca2+]i) in alphaT3-1 gonadotropes, to test for expression of excitatory GABA receptors. The GABAA agonists, GABA and muscimol, both caused rapid, robust and dose-dependent increases in [Ca2+]i (EC50 values 2.7 and 1 microM), whereas the GABAB agonist, baclofen, did not. The GABAA antagonist, bicuculline, inhibited muscimol's effect, whereas the GABAB antagonist, phaclofen, did not. The neuroactive steroid 5alpha-pregnan-3alpha-ol-11,20-dione (an allosteric activator of GABAA receptors) increased [Ca2+]i, and this effect, like that of muscimol, was inhibited by picrotoxin. The muscimol effect on [Ca2+]i was blocked by the VOCC antagonist, nifedipine, or by Ca2+-free medium. When cells were pretreated with muscimol this increased the spike phase of the [Ca2+]i response to subsequent stimulation with gonadotropin-releasing hormone (GnRH). Similar amplification was seen in muscimol-pretreated cells stimulated with GnRH in Ca2+-free medium, but not when cells were pretreated with muscimol in Ca2+-free medium. The amplification was not, however, GnRH receptor-specific, because the spike response to ionomycin was also increased by muscimol pretreatment. These data provide the first direct evidence for expression of excitatory GABAA receptors, and the first demonstration of acute steroid effects, on GnRH-responsive pituitary cells. They also reveal a novel mechanism by which GABAA activation modulates GnRH action, raising the possibility that this may also influence gonadotrophin secretion from non-immortalized gonadotropes.

Two splice variants of the human metabotropic glutamate receptor 7, named hmGluR7a and hmGluR7b, were isolated from a human brain cDNA library. The isoforms differ by an out-of-frame insertion of 92 nucleotides close to the C-terminus of the hmGluR7 coding region. hmGluR7a has a length of 915 amino acids and represents the human homolog of the recently cloned rat mGluR7. hmGluR7b is seven amino acids longer and exhibits a novel C-terminus of 23 amino acids in length. RT-PCR analysis demonstrated the existence of mGluR7b transcripts in wild-type mouse brain and its absence in mGluR7 knockout mice. Northern blot analyses indicate that mGluR7 expression is developmentally regulated. It is expressed at high levels in human fetal brain and at a lower level in many regions of adult human brain. Stimulation of hmGluR7b with l-2-amino-4-phosphonobutyrate (l-AP4), l-serine-O-phosphate (l-SOP) or l-glutamate in stably transfected Chinese hamster ovary (CHO) cells depressed forskolin-induced cAMP accumulation, whereas (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid ((1S,3R)-ACPD) and quisqualate (both at 1 mM) had no significant effects. As described for rat mGluR7, the rank order of agonist potencies is: l-SOP, l-AP4 > l-glutamate > (1S,3R)-ACPD, quisqualate. © 1997 Elsevier Science Ltd. All rights reserved.

Catalytic antibodies have created a new dimension in protein chemistry. In these studies it is particularly valuable to investigate systems for which natural enzymic catalysts are unknown. At Strathclyde we have examined several ways of preparing homochiral building blocks for organic synthesis. Antibodies that catalyse the Diels-Alder reaction have been characterized. The target reaction was the addition of acetoxybutadiene to N-substituted maleimides, a reaction that should give a pentafunctional homochiral building block. Catalytic antibodies can give insight into the mechanism of catalysis by proteins. We have investigated an adventitious hydrolytic antibody that cleaves activated esters. We have also shown that an antibody raised to ampicillin for analytical purposes catalyses hydrolysis of the beta-lactam ring.

gamma-amino butyric acid (GABA) is the major inhibitory neurotransmitter in the CNS, mediating fast inhibitory synaptic transmission, by activating GABAA receptors. However, these GABA-gated Cl- channels can also be excitatory, causing depolarization, and increasing Ca2+ entry via voltage-operated Ca2+ channels (VOCCs). Evidence exists for excitatory ionotropic GABA receptors in anterior pituitary cells, including gonadotropes, but these have not been directly characterized and their pharmacology remains controversial. Here we have measured the cytosolic Ca2+ concentration ([Ca2+]i) in alphaT3-1 gonadotropes, to test for expression of excitatory GABA receptors. The GABAA agonists, GABA and muscimol, both caused rapid, robust and dose-dependent increases in [Ca2+]i (EC50 values 2.7 and 1 microM), whereas the GABAB agonist, baclofen, did not. The GABAA antagonist, bicuculline, inhibited muscimol's effect, whereas the GABAB antagonist, phaclofen, did not. The neuroactive steroid 5alpha-pregnan-3alpha-ol-11,20-dione (an allosteric activator of GABAA receptors) increased [Ca2+]i, and this effect, like that of muscimol, was inhibited by picrotoxin. The muscimol effect on [Ca2+]i was blocked by the VOCC antagonist, nifedipine, or by Ca2+-free medium. When cells were pretreated with muscimol this increased the spike phase of the [Ca2+]i response to subsequent stimulation with gonadotropin-releasing hormone (GnRH). Similar amplification was seen in muscimol-pretreated cells stimulated with GnRH in Ca2+-free medium, but not when cells were pretreated with muscimol in Ca2+-free medium. The amplification was not, however, GnRH receptor-specific, because the spike response to ionomycin was also increased by muscimol pretreatment. These data provide the first direct evidence for expression of excitatory GABAA receptors, and the first demonstration of acute steroid effects, on GnRH-responsive pituitary cells. They also reveal a novel mechanism by which GABAA activation modulates GnRH action, raising the possibility that this may also influence gonadotrophin secretion from non-immortalized gonadotropes.

Catalytic antibodies have created a new dimension in protein chemistry. In these studies it is particularly valuable to investigate systems for which natural enzymic catalysts are unknown. At Strathclyde we have examined several ways of preparing homochiral building blocks for organic synthesis. Antibodies that catalyse the Diels-Alder reaction have been characterized. The target reaction was the addition of acetoxybutadiene to N-substituted maleimides, a reaction that should give a pentafunctional homochiral building block. Catalytic antibodies can give insight into the mechanism of catalysis by proteins. We have investigated an adventitious hydrolytic antibody that cleaves activated esters. We have also shown that an antibody raised to ampicillin for analytical purposes catalyses hydrolysis of the beta-lactam ring.

Antibodies raised to the bovine serum albumin conjugate of the adduct of acetoxybutadiene with N-(4-carboxybutanoyl)maleimide have been shown to catalyse the Diels-Alder cycloaddition of acetoxybutadiene with N-benzyl- and N-ethyl-maleimide. For one antibody, designated H11, the reaction was selective for 1-acetoxybutadiene; 1-methoxybutadiene and penta-2,4-diene were not substrates. Product inhibition was not observed but the reaction was found to be pH dependent showing a maximum rate at pH 8.5. Analysis of the products of cycloaddition catalysed by H11 indicated that the expected acetoxy adduct was obtained but underwent further reaction catalysed by H11 to afford the corresponding alcohol. This unexpected discovery of a dual catalytic activity associated with an antibody is discussed in the context of hydrolysis reactions catalysed by antibodies.

We conducted a preschool vision screening study using stereopsis testing with the Random Dot E and Lang stereotests as a complement to visual acuity measurement. Over 6000 children were screened. Stereopsis testing at a threshold of 600 seconds of arc was cognitively easier for the children than visual acuity measurement. At this threshold there was no effect on reducing the rate of visual acuity overreferrals, but ten children with abnormal binocular vision were detected who were not referred by visual acuity criteria. Though a large number of children passed only one of the two stereotests, there was no significant difference in their degree of difficulty. Stereopsis testing with these two stereotests may be a useful adjunct to preschool vision screening programs though further studies are required.