Systemic gene delivery transduces the enteric nervous system of guinea pigs and cynomolgus macaques.

Characterization of adeno-associated viral vector (AAV) mediated gene delivery to the enteric nervous system (ENS) was recently described in mice and rats. In these proof-of-concept experiments, we show that intravenous injections of clinically relevant AAVs can transduce the ENS in guinea pigs and non-human primates. Neonatal guinea pigs were given intravenous injections of either AAV8 or AAV9 vectors that contained a green fluorescent protein (GFP) expression cassette or phosphate-buffered saline. Piglets were euthanized three weeks post injection and tissues were harvested for immunofluorescent analysis. GFP expression was detected in myenteric and submucosal neurons along the length of the gastrointestinal tract in AAV8 injected guinea pigs. GFP-positive neurons were found in dorsal motor nucleus of the vagus and dorsal root ganglia. Less transduction occurred in AAV9-treated tissues. Gastrointestinal tissues were analyzed from young cynomolgus macaques that received systemic injection of AAV9 GFP. GFP expression was detected in myenteric neurons of the stomach, small and large intestine. These data demonstrate that ENS gene delivery translates to larger species. This work develops tools for the field of neurogastroenterology to explore gut physiology and anatomy using emerging technologies such as optogenetics and gene editing. It also provides a basis to develop novel therapies for chronic gut disorders.

Robust impurity detection and tracking for tokamaks.

A robust impurity detection and tracking code, able to generate large sets of dust tracks from tokamak camera footage, is presented. This machine learning-based code is tested with cameras from the Joint European Torus, Doublet-III-D, and Magnum-PSI and is able to generate dust tracks with a 65-100% classification accuracy. Moreover, the number dust particles detected from a single camera shot can be up to the order of 1000. Several areas of improvement for the code are highlighted, such as generating more significant training data sets and accounting for selection biases. Although the code is tested with dust in single two-dimensional camera views, it could easily be applied to multiple-camera stereoscopic reconstruction or nondust impurities.

Recurrent syncope for over a decade due to idiopathic ventricular fibrillation.

A 35-year-old man had a history of recurrent syncope for more than a decade. During a witnessed episode, an ambulatory electrocardiographic recording showed ventricular flutter/fibrillation that lasted for 2 1/2 minutes and terminated spontaneously without adverse neurologic sequelae. No structural heart disease and no possible etiologic factor for the ventricular tachyarrhythmia was found. The patient received an automatic implantable cardioverter defibrillator. Review of the literature suggests that the automatic implantable cardioverter defibrillator is a valid option in idiopathic ventricular fibrillation in young individuals to avoid the potential risk of recurrent cardiac arrest.

Effects of T cells on platelet-derived growth factor-like protein secretion from endothelial cells.

The cause of accelerated graft arteriosclerosis after heart transplantation is unknown. To examine whether the interactions of T cells and endothelial cells (ECs) could contribute to the cause of this phenomenon, T cells were co-incubated with human umbilical artery endothelial cells (HUAEC) and human vein endothelial cells (HUVEC) and the resulting conditioned medium supernatant was assayed for the presence of platelet-derived growth factor (PDGF)-like protein. PDGF-like protein secretion was significantly greater from HUAECs co-incubated with T cells at T-cell/HUAEC ratios of 30:1 (6.9 +/- 1.1 fmol/10(6) ECs) and 10:1 (6.0 +/- 1.1 fmol/10(6) ECs) than the combined background secretion from HUAECs and T cells incubated separately (3.6 +/- 0.8 fmol/10(6) ECs) (p less than 0.05). PDGF-like protein secretion above background levels from HUAECs was significantly greater, however, than from HUVECs co-incubated with T cells at T-cell/HUVEC ratios of 30:1 (1.0 +/- 0.4 fmol/10(6) ECs) and 10:1 (0.75 +/- 0.36 fmol/10(6) ECs) (p less than 0.05). In four experiments, preincubation of HUAECs with gamma-interferon induced HLA-DR antigen expression but actually caused a decrease in T-cell-induced PDGF-like protein secretion above background levels (3.0 +/- 0.6 fmol/10(6) ECs) when compared to nonstimulated HUAECs (4.0 +/- 0.4 fmol/10(6) ECs; p less than 0.05). PDGF-like protein secretion was minimal at 1 hour and increased over time to a maximum at 24 hours. The conclusion is that T cells are capable of inducing secretion of a very potent mitogen, PDGF-like protein, from endothelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Assay of the heat-labile enterotoxin of Escherichia coli in infant rabbits.

Infant rabbits were shown to respond to Escherichia coli heat-labile enterotoxin by a consistent increase in intestinal fluid content, which was maximal 5 h after oral dosing. Infant rabbits could be used in a simple quantitative assay for heat-labile E. coli enterotoxin based on the ratios of gut weight to remaining body weight 5 h after oral dosing. Infant rabbits remained responsive to heat-labile enterotoxin up to 14 days of age, after which their gastric pH became low enough to destroy the enterotoxin. Rabbits that had been deprived of food before being dosed had a reduced gastric pH and a reduced response to the enterotoxin. Lincomycin andmitomycin C were found not to increase th e yield of heat-labile enterotoxin from E. coli strain P307.

Treatment of infected left ventricular assist device using antibiotic-impregnated beads.

There is no well-established therapy for treating infections of heart-assist or artificial heart devices, a serious problem with life-threatening consequences. We used a promising new approach in which antibiotic-impregnated polymethylmethacrylate beads were placed around an implanted left ventricular assist device to control an external blood pump infection in a bridge-to-transplant patient. In this case report, we describe the potential of antimicrobial-impregnated polymethylmethacrylate beads for in situ control of infections involving external surfaces of cardiovascular devices.

Synthesized or digitized? A guide to the use of computer speech.

In addition to technical and cost determinants, a range of human factors issues governs the appropriateness of synthesized or digitized speech for a particular system. For example, since synthesized messages are created textually, they may reflect the rules and habits of written language, rather than spoken language. This may cause listeners some difficulty interpreting the intended meaning of the message. Moreover, the different speech media place constraints upon techniques of message creation editing, transmission and reception. Synthesized speech is easy to edit in terms of lexical content, but the production of sophisticated prosodic features can be problematic. In contrast, unedited digitized speech will normally have appropriate prosodic cues and because of this will be difficult to edit. The influence of these factors is examined and illustrations of both good and poor practice are given. The paper concludes with a decision criteria checklist for speech output devices.

Adolescent girls' attitudes toward pregnancy: the importance of asking what the boyfriend wants.

OBJECTIVE: We evaluated the factors associated with attitudes toward pregnancy among girls presenting to an adolescent health clinic to better predict which girls are at the highest risk of pregnancy. STUDY DESIGN: We used a cross-sectional provider-administered survey design. POPULATION: A total 202 girls aged 13 to 18 years presenting consecutively for reproductive health services to an adolescent care clinic were interviewed about their desire for pregnancy. Girls found to be already pregnant at the initial visit (n=54) were removed from analysis. OUTCOMES: measured The main outcome measured was desire for pregnancy. Subjects were grouped by those desiring pregnancy (n=16), those desiring to avoid pregnancy (n=107), and those ambivalent about pregnancy (n=25). RESULTS: The girls who were ambivalent about pregnancy were not significantly different from the girls desiring pregnancy. In unadjusted analysis, girls desiring pregnancy or who were ambivalent about it were more likely to be Hispanic, unemployed, to not attend school, to live with neither natural parent, and to have lived away from home for more than 2 weeks. In adjusted analysis, the reported attitude of the boyfriend toward having a child was the only significant predictor of adolescent girls&rsquo attitude toward pregnancy. CONCLUSIONS: The best predictor of an adolescent girl&rsquos attitude toward pregnancy is her perception of her boyfriends&rsquo desire for a baby. Primary care providers should include boyfriends in any efforts to delay pregnancy in at-risk adolescent girls. Teenagers who are ambivalent about whether they want to be pregnant do not differ significantly from those desiring pregnancy, and should be considered just as high risk.

Prognostic value of B-type natriuretic peptide in surgical palliation of children with single-ventricle congenital heart disease.

The objective of this prospective study was to assess the prognostic role of perioperative B-type natriuretic peptide (BNP) levels in infants and children with single-ventricle congenital heart disease undergoing Norwood, bidirectional cavopulmonary anastomosis (BCPA), or Fontan operation. BNP levels were measured at baseline, after cardiopulmonary bypass, 6 to 12 hours after surgery, and then daily until indwelling vascular catheters were removed. Outcome measures included length of mechanical ventilation, inotropic support, and hospital stay. Twenty subjects underwent 23 surgical procedures (13 Norwood, 5 BCPA, and 5 Fontan). BNP levels were significantly higher in patients undergoing a Norwood procedure compared with a BCPA or Fontan procedure (p < 0.01). BNP levels measured 6 to 12 hours after surgery were predictive of duration of hospitalization (p = 0.005) and inotropic support (p = 0.01). An increase in BNP level within 48 hours of extubation was observed in 92% of patients undergoing a Norwood procedure. Early postoperative BNP levels correlate significantly with the ensuing duration of inotropic support and length of hospitalization. An increase in BNP after extubation may be reflective of the degree of underlying cardiopulmonary instability. Further investigation is necessary to define this important relation.

Polemic: five proposals for a medical school admission policy.

Five proposals for admitting better applicants into medical school are discussed in this article: (1) An A level in a humanity or social science would be required, to supplement--not replace--the stringent science requirement. This would ensure that successful candidates would be better "primed" for the medical curriculum. (2) Extra points in the applicant's initial screening would be awarded for an A level in English literature. (3) There would be a minimum age of 23 for applicants, although a prior degree would not be required. This is to ensure that the applicants are mature enough to know themselves and the world better, to make a more informed and motivated choice of career, and to get more out of the humanities components of the curriculum. (4) A year's full-time experience in a healthcare or charity environment would be desirable. (5) Applicants would be given two lists of interview discussion topics to prepare: works of literature and topics in healthcare politics.

The dangers of medical ethics.

The dominant conception of medical ethics being taught in British and American medical schools is at best pointless and at worst dangerous, or so it will be argued. Although it is laudable that medical schools have now given medical ethics a secure place in the curriculum, they go wrong in treating it like a scientific body of knowledge. Ethics is a unique subject matter precisely because of its widespread familiarity in all areas of life, and any teaching has to start from this shared ethical understanding and from the familiar ethical concepts of ordinary language. Otherwise there is a real risk that spurious technocratic jargon will be deployed by teacher and student alike in the futile search for intellectual respectability, culminating in a misplaced sense of having "done" the ethics module. There are no better examples of such jargon than "consequentialism", "deontology", and the "Four Principles". At best, they cannot do the work they were designed to do and, at worst, they can lead student and practitioner into ignoring their own healthy ethical intuitions and vocabulary.

Interventional cardiac catheterization advances in nonsurgical approaches to congenital heart disease.

Interventional cardiac catheterization offers increased therapeutic options to many patients with congenital heart disease. Over the past year encouraging results have been reported in hundreds of patients with interatrial communications, patent ductus arteriosus, and pulmonary artery stenosis requiring stenting. The Amplatzer (AGA Medical Corporation, Golden Valley, MN, USA) family of atrial septal, ventricular septal, and ductus occluding devices shows particular promise. Other studies support the efficacy and safety of established procedures such as balloon valvuloplasty and coarctation angioplasty. In some areas, such as transcatheter perforation of atretic pulmonary valves and endovascular stenting for coarctation of the aorta, our technical abilities may be advancing faster than our understanding of the ultimate clinical impact of our treatment. As interventional cardiac catheterization procedures continue to develop, they must be evaluated carefully against alternative treatments.

B-type natriuretic peptide levels in congenital heart disease.

The objective of this study was to evaluate the potential role of B-type natriuretic peptide (BNP) levels in children with congenital heart disease undergoing cardiac catheterization. Measurement of plasma BNP concentration has been shown to be useful in the diagnosis, risk stratification, and management of adult patients with congestive heart failure, but little is known about the role of BNP in children with structural congenital heart disease. We measured plasma BNP levels using the Triage BNP test in patients with congenital heart disease referred for diagnostic or interventional cardiac catheterization. Plasma BNP concentration was measured in 96 children and 11 adults > or = 19 years old (7.9+/-8.3 years) undergoing heart catheterization for underlying congenital heart disease. BNP levels ranged from < 5 to > 1300 pg/ml, with a median BNP concentration of 19.0 pg/ml. Baseline BNP concentrations were > 100.0 pg/ml on 19 occasions in 17 patients. The pressure difference between the left ventricle and ascending aorta was 10-110 mmHg in 21 patients. BNP concentrations for this cohort ranged from < 5.0 to 1060.0 pg/ml and correlated with the degree of left ventricular outflow obstruction (correlation coefficient, 0.661; p = 0.001). This study suggests that with additional research, BNP concentration may prove to be a useful clinical tool in managing children and adults with congenital heart disease.

The absence of ongoing immunoglobulin gene hypermutation suggests a distinct mechanism for c-myc mutation in endemic Burkitt's lymphoma.

PURPOSE: Burkitt's lymphoma is a malignancy of mature, immunoglobulin (Ig)-bearing B cells characterized by translocation between c-myc and Ig gene loci. A role for the juxtaposed Ig genes in the mutation and deregulation of c-myc expression typical of endemic Burkitt's lymphoma (eBL) has been proposed, but never proven. Our objective was to determine whether Ig gene hypermutation is ongoing in eBL. METHODS: We isolated Ig heavy-chain sequences from K962 eBL tumor cells using reverse transcription and polymerase chain reaction (PCR) amplification. The PCR product was ligated into Bluescript II vectors. Multiple subclones were sequenced and the variable regions were compared for evidence of ongoing Ig hypermutation. RESULTS: Six total single base substitutions were observed within four of the nine subclones studied. Four substitutions resulted in amino acid changes and two were silent. There was no clustering of mutations in hypervariable regions, or a high incidence of amino acid replacement or link substitutions, all of which are characteristic of Ig hypermutation. The observed mutations occurred at a rate consistent with Taq polymerase error. CONCLUSIONS: Our data indicate that in the eBL tumor sample K962, the mechanism underlying c-myc mutation is distinct from that which gives rise to Ig hypermutation.

Tandem arrangement of the closely linked desmoglein genes on human chromosome 18.

The desmogleins, together with the desmocollins, both members of the cadherin superfamily, are the adhesive proteins of the desmosome type of cell junction, characteristically found in epithelial cells. Three different human desmoglein isoforms are encoded by separate genes (DSG1, DSG2, and DSG3) located on chromosome 18q12.1. DSG2 has been shown to be the most widely expressed in all desmosome-containing tissues, whereas DSG1 and DSG3 are expressed only in certain tissues, mostly stratified squamous epithelia. The desmoglein isoforms are expressed in a stratification-related manner in human epidermis, DSG1 being suprabasally expressed and DSG3 at a lower level, while DSG2 expression is weak and basal. Yeast artificial chromosome clones carrying all three known human desmoglein genes have now been isolated. The smallest clone containing all three DSG genes was 275 kb, and the three desmoglein genes were clustered within a region of less than 150 kb. From the types of clone obtained and from restriction enzyme analysis the order of the DSG genes and their orientation was deduced to be 5'-DSG1-DSG3-DSG2-3'. There thus appears to be some correspondence between the order of DSG genes and their expression within tissues, raising the intriguing possibility that the organization of the desmoglein gene cluster is required for properly regulated gene expression.

Sinus node dysfunction in tuberous sclerosis.

Tuberous sclerosis is an autosomal dominant disease with potential for involvement of the skin, brain, lungs, kidneys, and heart. A case of prolonged sinus node pause and episodes of unresponsiveness in a 21-week-old infant with tuberous sclerosis is described. The infant subsequently underwent placement of an epicardial pacemaker. This case illustrates the importance of electrocardiographic studies in infants with tuberous sclerosis and seizure-like episodes.

Internal mammary artery angiography should be a routine component of diagnostic coronary angiography.

Left internal mammary artery (LIMA) angiography was performed with diagnostic coronary angiography in 130 cases for which the coronary findings made use of the LIMA as a bypass graft a consideration. In 98% of the cases the approach to LIMA angiography was femoral with a 5F LIMA catheter first directed into the proximal subclavian and then advanced over a guidewire placed into the distal subclavian well beyond the origin of the LIMA. After withdrawing the wire the catheter was brought proximally to selectively cannulate and visualize the LIMA with nonionic contrast media. The only complication was a single transient occipital visual field loss. LIMA caliber too narrow to permit use as a graft was found twice, LIMA occlusion unrelated to prior surgery was found once, and LIMA occlusion related to prior surgery was found twice. Subclavian and/or vertebral stenosis was present five times. Large proximal branches of the LIMA best identified prior to surgery were present 12 times. Based on this experience, LIMA angiography 1) can be performed safely with a high degree of success, 2) demonstrates significant findings in 15% of cases, and 3) should therefore be performed whenever coronary angiographic findings make it appropriate to consider LIMA to coronary artery bypass grafting.