Heart Failure as the Initial Presentation of Anomalous Left Coronary Artery From the Pulmonary Artery.

Coronary arteries arising from the pulmonary artery have an incidence of 0.002% in the general population. We present a 29-year-old woman who presented to our hospital with acute decompensated heart failure and atrial fibrillation with a rapid ventricular rate. She underwent a cardiac catheterization to rule out ischemic disease, which revealed retrograde contrast flow through the left coronary artery from the right coronary artery. A coronary computed tomography (CT) angiogram was pursued which showed the presence of an anomalous left coronary artery arising from the pulmonary artery (ALCAPA). For the management of her atrial fibrillation, she was electrically cardioverted. She was discharged on guideline-directed medical therapy for her heart failure, with a cardiac surgery referral for the surgical fixation of her ALCAPA.

Long-term outcomes up to 25 years following balloon pulmonary valvuloplasty: A multicenter study.

OBJECTIVE: Evaluate long-term outcomes following balloon pulmonary valvuloplasty (BPV) for pulmonary stenosis (PS). BACKGROUND: Long-term data following BPV is limited to small, single center studies. METHODS: BPV from April 12, 1985 to January 7, 2015 from three centers were included. Outcomes studied were ≥ moderate PI by echocardiogram and residual PS ≥ 40 mm Hg. Risk factors for ≥ moderate PI, residual PS, and repeat intervention were assessed by univariate and multivariate analysis. RESULTS: Among 254 patients, mean age at BPV was 3.8 years (range 1 day-67 years), initial PS catheter gradient was 56 mm Hg (IQR 40-70), 19% had critical PS, and 9% had genetic syndromes. Mean follow-up duration was 7.5 years (maximum 25 years). Sixty-nine (29%) had ≥ moderate PI, 41 patients (17%) had residual PS > 40 mm Hg, and 31 (13%) had re-intervention. In univariate analysis, younger age, lower weight, greater initial PS gradient, greater initial RV/systemic pressure ratio, critical PS, and longer follow-up duration were associated with ≥ moderate PI. Greater initial PS gradient was associated with long-term residual PS or repeat intervention. In multivariate analysis, greater initial gradient and lower weight were independently associated with > moderate PI and greater initial PS gradient and genetic abnormality were independently associated with residual PS and repeat intervention. CONCLUSION: Smaller patients with greater initial PS were more likely to develop significant long-term PI. Patients with greater initial PS and genetic abnormalities were more likely to have residual PS or require repeat intervention following BPV.

The in vitro zebrafish heart as a model to investigate the chronotropic effects of vapor anesthetics.

In addition to their intended clinical actions, all general anesthetic agents in common use have detrimental intrasurgical and postsurgical side effects on organs and systems, including the heart. The major cardiac side effect of anesthesia is bradycardia, which increases the probability of insufficient systemic perfusion during surgery. These side effects also occur in all vertebrate species so far examined, but the underlying mechanisms are not clear. The zebrafish heart is a powerful model for studying cardiac electrophysiology, employing the same pacemaker system and neural control as do mammalian hearts. In this study, isolated zebrafish hearts were significantly bradycardic during exposure to the vapor anesthetics sevoflurane (SEVO), desflurane (DES), and isoflurane (ISO). Bradycardia induced by DES and ISO continued during pharmacological blockade of the intracardiac portion of the autonomic nervous system, but the chronotropic effect of SEVO was eliminated during blockade. Bradycardia evoked by vagosympathetic nerve stimulation was augmented during DES and ISO exposure; nerve stimulation during SEVO exposure had no effect. Together, these results support the hypothesis that the cardiac chronotropic effect of SEVO occurs via a neurally mediated mechanism, while DES and ISO act directly upon cardiac pacemaker cells via an as yet unknown mechanism.

Derivation of Continuum Models from An Agent-based Cancer Model: Optimization and Sensitivity Analysis.

BACKGROUND: Agent-based models provide a formidable tool for exploring complex and emergent behaviour of biological systems as well as accurate results but with the drawback of needing a lot of computational power and time for subsequent analysis. On the other hand, equation-based models can more easily be used for complex analysis in a much shorter timescale. METHODS & OBJECTIVE: This paper formulates an ordinary differential equations and stochastic differential equations model to capture the behaviour of an existing agent-based model of tumour cell reprogramming and applies it to optimization of possible treatment as well as dosage sensitivity analysis. RESULTS: For certain values of the parameter space a close match between the equation-based and agent-based models is achieved. The need for division of labour between the two approaches is explored.

Continuous Cardiopulmonary Bypass During the Repair of Total Anomalous Pulmonary Venous Return.

Circulatory arrest (CA) is traditionally utilized during the repair of total anomalous pulmonary venous return (TAPVR). Since 2005, we have exclusively repaired all types of TAPVR using continuous cardiopulmonary bypass. We present our technique using continuous cardiopulmonary bypass throughout the duration of the repair, by temporarily occluding the vertical vein and placing a pump sucker within the pulmonary venous confluence. This technique has been used on 29 consecutive patients and resulted in limited morbidity and absence of pulmonary vein stenosis from most recent follow-up.

Zebrafish heart as a model to study the integrative autonomic control of pacemaker function.

The cardiac pacemaker sets the heart's primary rate, with pacemaker discharge controlled by the autonomic nervous system through intracardiac ganglia. A fundamental issue in understanding the relationship between neural activity and cardiac chronotropy is the identification of neuronal populations that control pacemaker cells. To date, most studies of neurocardiac control have been done in mammalian species, where neurons are embedded in and distributed throughout the heart, so they are largely inaccessible for whole-organ, integrative studies. Here, we establish the isolated, innervated zebrafish heart as a novel alternative model for studies of autonomic control of heart rate. Stimulation of individual cardiac vagosympathetic nerve trunks evoked bradycardia (parasympathetic activation) and tachycardia (sympathetic activation). Simultaneous stimulation of both vagosympathetic nerve trunks evoked a summative effect. Effects of nerve stimulation were mimicked by direct application of cholinergic and adrenergic agents. Optical mapping of electrical activity confirmed the sinoatrial region as the site of origin of normal pacemaker activity and identified a secondary pacemaker in the atrioventricular region. Strong vagosympathetic nerve stimulation resulted in a shift in the origin of initial excitation from the sinoatrial pacemaker to the atrioventricular pacemaker. Putative pacemaker cells in the sinoatrial and atrioventricular regions expressed adrenergic ß2 and cholinergic muscarinic type 2 receptors. Collectively, we have demonstrated that the zebrafish heart contains the accepted hallmarks of vertebrate cardiac control, establishing this preparation as a viable model for studies of integrative physiological control of cardiac function by intracardiac neurons.

Intrinsic and extrinsic innervation of the heart in zebrafish (Danio rerio).

In the vertebrate heart the intracardiac nervous system is the final common pathway for autonomic control of cardiac output, but the neuroanatomy of this system is not well understood. In this study we investigated the innervation of the heart in a model vertebrate, the zebrafish. We used antibodies against acetylated tubulin, human neuronal protein C/D, choline acetyltransferase, tyrosine hydroxylase, neuronal nitric oxide synthase, and vasoactive intestinal polypeptide to visualize neural elements and their neurotransmitter content. Most neurons were located at the venous pole in a plexus around the sinoatrial valve; mean total number of cells was 197 ± 23, and 92% were choline acetyltransferase positive, implying a cholinergic role. The plexus contained cholinergic, adrenergic, and nitrergic axons and vasoactive intestinal polypeptide-positive terminals, some innervating somata. Putative pacemaker cells near the plexus showed immunoreactivity for hyperpolarization-activated cyclic nucleotide-gated channel 4 (HCN4) and the transcription factor Islet-1 (Isl1). The neurotracer neurobiotin showed that extrinsic axons from the left and right vagosympathetic trunks innervated the sinoatrial plexus proximal to their entry into the heart; some extrinsic axons from each trunk also projected into the medial dorsal plexus region. Extrinsic axons also innervated the atrial and ventricular walls. An extracardiac nerve trunk innervated the bulbus arteriosus and entered the arterial pole of the heart to innervate the proximal ventricle. We have shown that the intracardiac nervous system in the zebrafish is anatomically and neurochemically complex, providing a substrate for autonomic control of cardiac effectors in all chambers.

Surgical and procedural skills training at medical school - a national review.

This national study quantifies procedural and surgical skills training at medical schools in the United Kingdom (UK), a stipulated requirement of all graduates by the General Medical Council (GMC). A questionnaire recorded basic procedural and surgical skills training provided by medical schools and surgical societies in the UK. Skills were extracted from (1) GMC Tomorrows Doctors and (2) The Royal College of Surgeons Intercollegiate Basic Surgical Skills (BSS) course. Data from medical school curricula and extra-curricular student surgical societies were compared against the national GMC guidelines and BSS course content. Data were analysed using Mann-Whitney U tests. Representatives from 23 medical schools completed the survey (71.9% response). Thirty one skills extracted from the BSS course were split into 5 categories, with skills content cross referenced against GMC documentation. Training of surgical skills by medical schools was as follows: Gowning and gloving (72.8%), handling instruments (29.4%), knot tying (17.4%), suturing (24.7%), other surgical techniques (4.3%). Surgical societies provided significantly more training of knot tying (64.4%, P = 0.0013) and suturing (64.5%, P = 0.0325) than medical schools. Medical schools provide minimal basic surgical skills training, partially supplemented by extracurricular student surgical societies. Our findings suggest senior medical students do not possess simple surgical and procedural skills. Newly qualified doctors are at risk of being unable to safely perform practical procedures, contradicting GMC Guidelines. We propose a National Undergraduate Curriculum in Surgery and Surgical Skills to equip newly qualified doctors with basic procedural skills to maximise patient safety.

The structure of the caudal wall of the zebrafish (Danio rerio) swim bladder: evidence of localized lamellar body secretion and a proximate neural plexus.

In this study, we present a morphological description of the fine structure of the tissues composing the caudal tip of the adult zebrafish swim bladder and an immunochemical survey of the innervation at this site. The internal aspect of the caudal tip is lined by an epithelium specialized to secrete surfactant into the lumen as evinced by the exocytosis of lamellar bodies. The sole innervation to this region consists of a neural plexus, present on the external surface, of nitric oxide synthase-positive (nNOS) neuronal cell bodies that are contacted by axon terminals, some containing neuropeptide Y and vasoactive intestinal polypeptide. As the specialized epithelium and neural plexus are coincident and of common extent, we suggest that the morphological relationship between the two elements allows the nervous system to affect surfactant processing, possibly through a paracrine mechanism.

Surgical Safety Training of World Health Organization Initiatives.

Undergraduate training in surgical safety is essential to maximize patient safety. This national review quantified undergraduate surgical safety training. Training of 2 international safety initiatives was quantified: (1) World Health Organization (WHO) "Guidelines for Safe Surgery" and (2) Department of Health (DoH) "Principles of the Productive Operating Theatre." Also, 13 additional safety skills were quantified. Data were analyzed using Mann-Whitney U tests. In all, 23 universities entered the study (71.9% response). Safety skills from WHO and DoH documents were formally taught in 4 UK medical schools (17.4%). Individual components of the documents were taught more frequently (47.6%). Half (50.9%) of the additional safety skills identified were taught. Surgical societies supplemented safety training, although the total amount of training provided was less than that in university curricula (P < .0001). Surgical safety training is inadequate in UK medical schools. To protect patients and maximize safety, a national undergraduate safety curriculum is recommended.

Regional innervation of the heart in the goldfish, Carassius auratus: a confocal microscopy study.

The intracardiac nervous system represents the final common pathway for autonomic control of the vertebrate heart in maintaining cardiovascular homeostasis. In teleost fishes, details of the organization of this system are not well understood. Here we investigated innervation patterns in the heart of the goldfish, a species representative of a large group of cyprinids. We used antibodies against the neuronal markers zn-12, acetylated tubulin, and human neuronal protein C/D, as well as choline acetyltransferase, tyrosine hydroxylase, nitric oxide synthetase, and vasoactive intestinal polypeptide (VIP) to detect neural elements and their transmitter contents in wholemounts and sections of cardiac tissue. All chambers of the heart were innervated by choline acetyltransferase-positive axons, implying cholinergic regulation; and by tyrosine hydroxylase-containing axons, implying adrenergic regulation. The mean total number of intracardiac neurons was 713 ± 78 (SE), nearly half of which were cholinergic. Neuronal somata were mainly located in a ganglionated plexus around the sinoatrial valves. Somata were contacted by cholinergic, adrenergic, nitrergic, and VIP-positive terminals. Putative pacemaker cells, identified by immunoreactivity for hyperpolarization activated, cyclic nucleotide-gated channel 4, were located in the base of the sinoatrial valves, and this region was densely innervated by cholinergic and adrenergic terminals. We have shown that the goldfish heart possesses the necessary neuroanatomical substrate for fine, region-by-region autonomic control of the myocardial effectors that are involved in determining cardiac output.

Total Hip Arthroplasty in A Young Patient with Bernard-Soulier Syndrome.

INTRODUCTION: The management of patients with coagulopathic disorders undergoing orthopaedic surgery requires a dedicated, multi-disciplinary team with detailed perioperative planning. Bernard-Soulier Syndrome (BSS) is an extremely rare disorder, affecting 1 in 1 million individuals worldwide. It is caused by a deficiency in glycoprotein 1b-V-IX which is required for normal platelet-mediated clot formation. The deficiency results in prolonged bleeding time with high risk of spontaneous bleeds. Few reports exist in the clinical literature of BSS patients undergoing major surgery. CASE REPORT: A 40 year old, female with known BSS and developmental dysplasia of her left hip (DDH) was referred to us for consideration of left total hip arthroplasty (THA). Consultation with her Haematologist for pre-operative optimization of platelets and related clotting times together with detailed discussions of her intended anaesthesia protocol and surgery resulted in a successful operation with less than anticipated blood loss. She entered our rehabilitation program just one week after surgery. CONCLUSION: BSS is an extremely rare bleeding disorder that puts patients at very high risk of blood loss following surgery. This is the first report that we are aware of describing a BSS patient undergoing a THA. A cohesive, highly specialized, multi-disciplinary team is crucial to the success of these patients.

Mentoring in pediatric oncology: a report from the Children's Oncology Group Young Investigator Committee.

A formal Mentorship Program within the Children's Oncology Group (COG) was established to pair young investigators (mentees) with established COG members (mentors). Despite the American Academy of Pediatrics policy statement promoting mentorship programs, there are no publications describing and evaluating national mentorship programs in pediatric subspecialties. In this study, a series of internal program evaluations were performed using surveys of both mentors and mentees. Responses were deidentified and analyzed to determine the utility of the program by both participant satisfaction and self-reported academic productivity. Results indicated that mentees were generally satisfied with the program. Mentor-mentee pairs that met at least quarterly demonstrated greater academic productivity than pairings that met less frequently. This formal mentorship program appeared to have subjective and objective utility for the development of academic pediatric subspecialists.

Patterning of the adult mandibulate mouthparts in the red flour beetle, Tribolium castaneum.

Specialized insect mouthparts, such as those of Drosophila, are derived from an ancestral mandibulate state, but little is known about the developmental genetics of mandibulate mouthparts. Here, we study the metamorphic patterning of mandibulate mouthparts of the beetle Tribolium castaneum, using RNA interference to deplete the expression of 13 genes involved in mouthpart patterning. These data were used to test three hypotheses related to mouthpart development and evolution. First, we tested the prediction that maxillary and labial palps are patterned using conserved components of the leg-patterning network. This hypothesis was strongly supported: depletion of Distal-less and dachshund led to distal and intermediate deletions of these structures while depletion of homothorax led to homeotic transformation of the proximal maxilla and labium, joint formation required the action of Notch signaling components and odd-skipped paralogs, and distal growth and patterning required epidermal growth factor (EGF) signaling. Additionally, depletion of abrupt or pdm/nubbin caused fusions of palp segments. Second, we tested hypotheses for how adult endites, the inner branches of the maxillary and labial appendages, are formed at metamorphosis. Our data reveal that Distal-less, Notch signaling components, and odd-skipped paralogs, but not dachshund, are required for metamorphosis of the maxillary endites. Endite development thus requires components of the limb proximal-distal axis patterning and joint segmentation networks. Finally, adult mandible development is considered in light of the gnathobasic hypothesis. Interestingly, while EGF activity is required for distal, but not proximal, patterning of other appendages, it is required for normal metamorphic growth of the mandibles.

Effects of altered ambient pressure on the volume and distribution of gas within the swimbladder of the adult zebrafish, Danio rerio.

Many teleosts use gas-filled swimbladders to control buoyancy and influence three-dimensional orientation (pitch and roll). However, swimbladder volume, and its contributions to these functions, varies with depth-related pressure according to Boyle's law. Moreover, the swimbladder volume at a given depth also depends on the compliance of the swimbladder wall, but this latter factor has been investigated in only a limited number of species. In this study, changes in the volume of the zebrafish swimbladder were observed both in vitro and in situ in pressure chambers that allowed simulations of movements within the water column to and from depths of >300 cm. Results show the anterior chamber to be highly compliant, varying ±38% from its initial volume over the range of simulated depths. This large volume change was accomplished, at least in part, by a series of regular corrugations running along the ventral aspect of the chamber wall and another set of pleats radiating from around the communicating duct in the caudal aspect of the chamber wall. The posterior chamber, in contrast, was found to be minimally compliant, varying only a fraction of a percent from its initial volume over the same pressure range. The different volumetric responses of the chambers caused a significant shift in the distribution of gas within the swimbladder system, but only resulted in a change in the whole-body pitch angle of ±2 deg over the range of pressures tested. Together, our findings provide new insights into the control of buoyancy and trim within teleosts and suggest novel mechanisms that may contribute to swimbladder performance.

Simultaneous chiral separation of methylamphetamine and common precursors using gas chromatography/mass spectrometry.

Methylamphetamine, ephedrine, and pseudoephedrine were derivatized using trifluoroacetic anhydride and enantiomers of each were analyzed using gas chromatography coupled to mass spectrometry (GC/MS) fitted with a γ-cyclodextrin (Chiraldex™ G-PN) chiral column. A temperature-programmed method was developed and optimized and the results compared with those obtained using a previously published isothermal GC method applied to GC/MS analysis. Trifluoroacetylated 3-(trifluoromethyl)phenethylamine hydrochloride was used as an internal standard, and mass fragmentation patterns are proposed for all derivatives analyzed. Qualitative validation of the optimized chromatographic conditions was completed in accordance with the guidelines published by the United Nations Office on Drugs and Crime (UNODC). Under conditions of repeatability and reproducibility, the method gave relative retention times with a relative standard deviation of less than 0.02% for all six analytes of interest. This surpasses the UNODC's acceptance criteria of 2% for validation of qualitative precision. Ephedrine and pseudoephedrine are common precursors in the clandestine manufacture of methylamphetamine. Seizures of illicit methylamphetamine therefore often contain mixtures of these optically active compounds. The simultaneous enantioseparation of these compounds to produce a profile would provide valuable information to law enforcement agencies regarding the provenance of a methylamphetamine seizure.

Requirement of FADD, NEMO, and BAX/BAK for aberrant mitochondrial function in tumor necrosis factor alpha-induced necrosis.

Necroptosis represents a form of alternative programmed cell death that is dependent on the kinase RIP1. RIP1-dependent necroptotic death manifests as increased reactive oxygen species (ROS) production in mitochondria and is accompanied by loss of ATP biogenesis and eventual dissipation of mitochondrial membrane potential. Here, we show that tumor necrosis factor alpha (TNF-α)-induced necroptosis requires the adaptor proteins FADD and NEMO. FADD was found to mediate formation of the TNF-α-induced pronecrotic RIP1-RIP3 kinase complex, whereas the IκB Kinase (IKK) subunit NEMO appears to function downstream of RIP1-RIP3. Interestingly, loss of RelA potentiated TNF-α-dependent necroptosis, indicating that NEMO regulates necroptosis independently of NF-κB. Using both pharmacologic and genetic approaches, we demonstrate that the overexpression of antioxidants alleviates ROS elevation and necroptosis. Finally, elimination of BAX and BAK or overexpression of Bcl-x(L) protects cells from necroptosis at a later step. These findings provide evidence that mitochondria play an amplifying role in inflammation-induced necroptosis.

Chiral gas chromatography as a tool for investigations into illicitly manufactured methylamphetamine.

The aim of this study was to develop a chiral gas chromatographic method for the separation of compounds likely to be found in the EMDE synthesis of methylamphetamine, a heavily abused stimulant drug. Here we describe the separation of the enantiomers of ephedrine, pseudoephedrine, chlorinated intermediates and methylamphetamine using fluorinated acid anhydrides as chemical derivatization reagents prior to gas chromatographic analysis on a 2,3-di-O-methyl-6-t-butyl silyl-ß-cyclodextrin stationary phase (CHIRALDEX™ B-DM). Separation of the enantiomers of pseudoephedrine, methylamphetamine and chloro-intermediates was achieved using PFPA derivatization, and enantiomers of ephedrine using TFAA derivatization, in run times of less than 40 minutes. The use of HFBA as a derivatization reagent for this set of analytes is also discussed.