Cleavage of the pseudoprotease iRhom2 by the signal peptidase complex reveals an ER-to-nucleus signaling pathway.

iRhoms are pseudoprotease members of the rhomboid-like superfamily and are cardinal regulators of inflammatory and growth factor signaling; they function primarily by recognizing transmembrane domains of their clients. Here, we report a mechanistically distinct nuclear function of iRhoms, showing that both human and mouse iRhom2 are non-canonical substrates of signal peptidase complex (SPC), the protease that removes signal peptides from secreted proteins. Cleavage of iRhom2 generates an N-terminal fragment that enters the nucleus and modifies the transcriptome, in part by binding C-terminal binding proteins (CtBPs). The biological significance of nuclear iRhom2 is indicated by elevated levels in skin biopsies of patients with psoriasis, tylosis with oesophageal cancer (TOC), and non-epidermolytic palmoplantar keratoderma (NEPPK); increased iRhom2 cleavage in a keratinocyte model of psoriasis; and nuclear iRhom2 promoting proliferation of keratinocytes. Overall, this work identifies an unexpected SPC-dependent ER-to-nucleus signaling pathway and demonstrates that iRhoms can mediate nuclear signaling.

p63 is a key regulator of iRHOM2 signalling in the keratinocyte stress response.

Hyperproliferative keratinocytes induced by trauma, hyperkeratosis and/or inflammation display molecular signatures similar to those of palmoplantar epidermis. Inherited gain-of-function mutations in RHBDF2 (encoding iRHOM2) are associated with a hyperproliferative palmoplantar keratoderma and squamous oesophageal cancer syndrome (termed TOC). In contrast, genetic ablation of rhbdf2 in mice leads to a thinning of the mammalian footpad, and reduces keratinocyte hyperproliferation and migration. Here, we report that iRHOM2 is a novel target gene of p63 and that both p63 and iRHOM2 differentially regulate cellular stress-associated signalling pathways in normal and hyperproliferative keratinocytes. We demonstrate that p63-iRHOM2 regulates cell survival and response to oxidative stress via modulation of SURVIVIN and Cytoglobin, respectively. Furthermore, the antioxidant compound Sulforaphane downregulates p63-iRHOM2 expression, leading to reduced proliferation, inflammation, survival and ROS production. These findings elucidate a novel p63-associated pathway that identifies iRHOM2 modulation as a potential therapeutic target to treat hyperproliferative skin disease and neoplasia.

Tetanus in New Zealand children: Intensive care management of a vaccine preventable disease.

AIM: To review management of children admitted with tetanus to Starship Children's Hospital from 2000 to 2013. METHODS: Retrospective chart review of children aged 0-15 years admitted to Starship Children's Hospital with tetanus from 2000 to 2013. Follow-up of immunisation status was via the National Immunisation Register and/or phone contact with patient's primary health care provider. RESULTS: Four cases of tetanus occurred, all in unimmunised children. All four required paediatric intensive care unit admission (length of stay (LOS) 2.5-7 weeks) for ventilatory support; three required tracheostomy. Specific tetanus treatment included metronidazole, tetanus immunoglobulin and antispasmodic medications such as magnesium sulphate and benzodiazepines. Three remain partially or unimmunised following discharge. CONCLUSION: Tetanus in children is a rare but preventable life-threatening disease, requiring costly intensive care management. Immunisation is cheap and effective in preventing tetanus and should be offered to all children, including tetanus cases for their future protection.

Efficacy of a Standardized Computer-Based Training Curriculum to Teach Echocardiographic Identification of Rheumatic Heart Disease to Nonexpert Users.

The ability to integrate echocardiographic for rheumatic heart disease (RHD) into RHD prevention programs is limited because of lack of financial and expert human resources in endemic areas. Task shifting to nonexperts is promising; but investigations into workforce composition and training schemes are needed. The objective of this study was to test nonexperts' ability to interpret RHD screening echocardiograms after a brief, standardized, computer-based training course. Six nonexperts completed a 3-week curriculum on image interpretation. Participant performance was tested in a school-screening environment in comparison to the reference approach (cardiologists, standard portable echocardiography machines, and 2012 World Heart Federation criteria). All participants successfully completed the curriculum, and feedback was universally positive. Screening was performed in 1,381 children (5 to 18 years, 60% female), with 397 (47 borderline RHD, 6 definite RHD, 336 normal, and 8 other) referred for handheld echo. Overall sensitivity of the simplified approach was 83% (95% CI 76% to 89%), with an overall specificity of 85% (95% CI 82% to 87%). The most common reasons for false-negative screens (n = 16) were missed mitral regurgitation (MR; 44%) and MR ≤1.5 cm (29%). The most common reasons for false-positive screens (n = 179) included identification of erroneous color jets (25%), incorrect MR measurement (24%), and appropriate application of simplified guidelines (39.4%). In conclusion, a short, independent computer-based curriculum can be successfully used to train a heterogeneous group of nonexperts to interpret RHD screening echocardiograms. This approach helps address prohibitive financial and workforce barriers to widespread RHD screening.

Handheld echocardiographic screening for rheumatic heart disease by non-experts.

OBJECTIVES: Handheld echocardiography (HAND) has good sensitivity and specificity for rheumatic heart disease (RHD) when performed by cardiologists. However, physician shortages in RHD-endemic areas demand less-skilled users to make RHD screening practical. We examine nurse performance and interpretation of HAND using a simplified approach for RHD screening. METHODS: Two nurses received training on HAND and a simplified screening approach. Consented students at two schools in Uganda were eligible for participation. A simplified approach (HAND performed and interpreted by a non-expert) was compared with the reference standard (standard portable echocardiography, performed and interpreted by experts according to the 2012 World Heart Federation guidelines). Reasons for false-positive and false-negative HAND studies were identified. RESULTS: A total of 1002 children were consented, with 956 (11.1 years, 41.8% male) having complete data for review. Diagnoses included: 913 (95.5%) children were classified normal, 32 (3.3%) borderline RHD and 11 (1.2%) definite RHD. The simplified approach had a sensitivity of 74.4% (58.8% to 86.5%) and a specificity of 78.8% (76.0% to 81.4%) for any RHD (borderline and definite). Sensitivity improved to 90.9% (58.7% to 98.5%) for definite RHD. Identification and measurement of erroneous colour jets was the most common reason for false-positive studies (n=164/194), while missed mitral regurgitation and shorter regurgitant jet lengths with HAND were the most common reasons for false-negative studies (n=10/11). CONCLUSIONS: Non-expert-led HAND screening programmes offer a potential solution to financial and workforce barriers that limit widespread RHD screening. Nurses trained on HAND using a simplified approach had reasonable sensitivity and specificity for RHD screening. Information on reasons for false-negative and false-positive screening studies should be used to inform future training protocols, which could lead to improved screening performance.

Handheld echocardiography versus auscultation for detection of rheumatic heart disease.

BACKGROUND: Rheumatic heart disease (RHD) remains a major public health concern in developing countries, and routine screening has the potential to improve outcomes. Standard portable echocardiography (STAND) is far more sensitive than auscultation for the detection of RHD but remains cost-prohibitive in resource-limited settings. Handheld echocardiography (HAND) is a lower-cost alternative. The purpose of this study was to assess the incremental value of HAND over auscultation to identify RHD. METHODS: RHD screening was completed for schoolchildren in Gulu, Uganda, by using STAND performed by experienced echocardiographers. Any child with mitral or aortic regurgitation or stenosis plus a randomly selected group of children with normal STAND findings underwent HAND and auscultation. STAND and HAND studies were interpreted by 6 experienced cardiologists using the 2012 World Heart Federation criteria. Sensitivity and specificity of HAND and auscultation for the detection of RHD and pathologic mitral or aortic regurgitation were calculated by using STAND as the gold standard. RESULTS: Of 4773 children who underwent screening with STAND, a subgroup of 1317 children underwent HAND and auscultation. Auscultation had uniformly poor sensitivity for the detection of RHD or valve disease. Sensitivity was significantly improved by using HAND compared with auscultation for the detection of definite RHD (97.8% vs 22.2%), borderline or definite RHD (78.4% vs 16.4%), and pathologic aortic insufficiency (81.8% vs 13.6%). CONCLUSIONS: Auscultation alone is a poor screening test for RHD. HAND significantly improves detection of RHD and may be a cost-effective screening strategy for RHD in resource-limited settings.

Simplified rheumatic heart disease screening criteria for handheld echocardiography.

BACKGROUND: Using 2012 World Heart Federation criteria, standard portable echocardiography (STAND) reveals a high burden of rheumatic heart disease (RHD) in resource-poor settings, but widespread screening is limited by cost and physician availability. Handheld echocardiography (HAND) may decrease costs, but World Heart Federation criteria are complicated for rapid field screening, particularly for nonphysician screeners. The aim of this study was to determine the best simplified screening strategy for RHD detection using HAND. METHODS: In this prospective study, STAND (GE Vivid q or i or Philips CX-50) was performed in five schools in Gulu, Uganda; a random subset plus all children with detectable mitral regurgitation or aortic insufficiency also underwent HAND (GE Vscan). Borderline or definite RHD cases were defined by 2012 World Heart Federation criteria on STAND images, by two experienced readers. HAND studies were reviewed by cardiologists blinded to STAND results. Single and combined HAND parameters were evaluated to determine the simplified screening strategy that maximized sensitivity and specificity for case detection. RESULTS: In 1,439 children (mean age, 10.8 ± 2.6 years; 47% male) with HAND and STAND studies, morphologic criteria and the presence of any mitral regurgitation by HAND had poor specificity. The presence of aortic insufficiency was specific but not sensitive. Combined criteria of mitral regurgitation jet length ≥ 1.5 cm or any aortic insufficiency best balanced sensitivity (73.3%) and specificity (82.4%), with excellent sensitivity for definite RHD (97.9%). With a prevalence of 4% and subsequent STAND screening of positive HAND studies, this would reduce STAND studies by 80% from a STAND-based screening strategy. CONCLUSIONS: In resource-limited settings, HAND with simplified criteria can detect RHD with good sensitivity and specificity and decrease the need for standard echocardiography. Further study is needed to validate screening by local practitioners and long-term outcomes.

The utility of handheld echocardiography for early rheumatic heart disease diagnosis: a field study.

AIMS: The World Heart Federation (WHF) guidelines for rheumatic heart disease (RHD) are designed for a standard portable echocardiography (STAND) machine. A recent study in a tertiary care centre demonstrated that they also had good sensitivity and specificity when modified for use with handheld echocardiography (HAND). Our study aimed to evaluate the performance of HAND for early RHD diagnosis in the setting of a large-scale field screening. METHODS AND RESULTS: STAND was performed in 4773 children in Gulu, Uganda, with 10% randomly assigned to also undergo HAND. Additionally, any child with mitral or aortic regurgitation also underwent HAND. Studies were performed by experienced echocardiographers and blindly reviewed by cardiologists using 2012 WHF criteria, which were modified slightly for HAND--due to the lack of spectral Doppler capability. Paired echocardiograms were performed in 1420 children (mean age 10.8 and 53% female), resulting in 1234 children who were normal, 133 who met criteria for borderline RHD, 47 who met criteria for definite RHD, and 6 who had other diagnoses. HAND had good sensitivity and specificity for RHD detection (78.9 and 87.2%, respectively), but was most sensitive for definite RHD (97.9%). Inter- and intra-reviewer agreement ranged between 66-83 and 71.4-94.1%, respectively. CONCLUSIONS: HAND has good sensitivity and specificity for diagnosis of early RHD, performing best for definite RHD. Protocols for RHD detection utilizing HAND will need to include confirmation by STAND to avoid over-diagnosis. Strategies that evaluate simplified screening protocols and training of non-physicians hold promise for more wide spread deployment of HAND-based protocols.

Longitudinal strain and strain rate in patients with hemodynamically significant ventricular septal defects.

BACKGROUND: Patients with significant overcirculation from large ventricular septal defects (VSDs) may have altered contractility compared to normal patients. METHODS: Patients were enrolled prospectively. Patients were excluded if they were acutely ill or over age five. Left ventricular longitudinal strain and strain rate were measured in patients with VSDs referred for surgical correction and control participants with structurally normal hearts. RESULTS: There was no difference in the average longitudinal strain or strain rate of six segments in the left ventricle. The mean for both the groups was 19.9% (P = .95). Strain rate was 1.5 s(-1) in the patients with a VSD and 1.42 s(-1) in the control group (P = .30). The left ventricular end diastolic dimension was significantly larger in the group with ventricular defects (z score 1.38 vs -0.37) than the control group (P = .000). CONCLUSIONS: The left ventricle end-diastolic dimension in patients with ventricular defects was significantly larger, but there was no difference in longitudinal strain or strain rate.

Impact of telemedicine on hospital transport, length of stay, and medical outcomes in infants with suspected heart disease: a multicenter study.

BACKGROUND: Previous single-center studies have shown that telemedicine improves care in newborns with suspected heart disease. The aim of this study was to test the hypothesis that telemedicine would shorten time to diagnosis, prevent unnecessary transports, reduce length of stay, and decrease exposure to invasive treatments. METHODS: Nine pediatric cardiology centers entered data prospectively on patients aged <6 weeks, matched by gestational age, weight, and diagnosis. Subjects born at hospitals with and without access to telemedicine constituted the study group and control groups, respectively. Data from patients with mild or no heart disease were analyzed. RESULTS: Data were obtained for 337 matched pairs with mild or no heart disease. Transport to a tertiary care center (4% [n = 15] vs 10% [n = 32], P = .01), mean time to diagnosis (100 vs 147 min, P < .001), mean length of stay (1.0 vs 26 days, P = .005) and length of intensive care unit stay (0.96 vs 2.5 days, P = .024) were significantly less in the telemedicine group. Telemedicine patients were significantly farther from tertiary care hospitals than control subjects. The use of inotropic support and indomethacin was significantly less in the telemedicine group. By multivariate analysis, telemedicine patients were less likely to be transported (odds ratio, 0.44; 95% confidence interval, 0.23-0.83) and less likely to be placed on inotropic support (odds ratio, 0.16; 95% confidence interval, 0.10-0.28). CONCLUSIONS: Telemedicine shortened the time to diagnosis and significantly decreased the need for transport of infants with mild or no heart disease. The length of hospitalization and intensive care stay and use of indomethacin and inotropic support were less in telemedicine patients.

Motion sickness prevention by an 8-Hz stroboscopic environment during air transport.

INTRODUCTION: Previous research has shown that retinal slip can be a significant factor in causing motion sickness. Stroboscopic illumination may prevent retinal slip by providing snapshots of the visual environment that are brief enough so each image is stationary on the retina. METHODS: The purpose of this study was to determine the effectiveness of an 8-Hz stroboscopic environment as a motion sickness countermeasure for passengers during a nauseogenic flight in a helicopter. The study population was comprised of 18 motion sickness susceptible subjects. Subjects completed a motion sickness symptom questionnaire, a psychomotor vigilance test, weapons utilization tasks, a time estimation task, and a sustained attention task after nauseogenic flights with and without 8-Hz stroboscopic illumination in the cabin. RESULTS: Baseline-corrected scores of self-reported nausea were significantly lower after the stroboscopic condition (M = 36.57 +/- 6.95) than the nonstroboscopic condition (M = 50.88 +/- 7.36). Furthermore, the stroboscopic condition resulted in significantly better performance on the vigilance task than the nonstroboscopic condition. However, baseline-corrected scores of oculomotor symptoms were greater after the stroboscopic condition (M = 33.27 +/- 5.52) than the nonstroboscopic condition (M = 24.85 +/- 4.10). DISCUSSION: These results support the use of stroboscopic illumination as a nonpharmacologic countermeasure for motion sickness related to retinal slip. However, due to the uncontrolled nature of the flights, the possibility that these results could have been influenced by differences in motion between flights cannot be excluded. This technology should be investigated in other forms of transportation (i.e., ground vehicles).

Modafinil as a replacement for dextroamphetamine for sustaining alertness in military helicopter pilots.

INTRODUCTION: Successful military aviation operations depend on maintaining continuous day-night operations. Stimulants are easy to use and popular for sustaining performance because their utility is not dependent upon environmental or scheduling modifications. Dextroamphetamine is authorized for use by the aircrews of all U.S. military services, but its potential for abuse and subsequent addiction is of aeromedical concern. Finding an alternative stimulant, such as modafinil, that displays a low affinity for dopamine uptake binding sites would prove extremely beneficial. This study sought to establish the efficacy and safety of modafinil during actual flying operations, thus providing the operational validity desired to approve the use of modafinil for helicopter flight operations. METHODS: During two, 40-h periods of sustained wakefulness, 18 helicopter pilots (17 men, 1 woman, mean years of age = 29.5) each completed 15 flights and other evaluations, during which they received 2 of 3 experimental conditions: 3 doses at 4-h intervals of modafinil (100 mg), dextroamphetamine (5 mg), or placebo. RESULTS: Statistical results showed that modafinil, like dextroamphetamine, maintained alertness, feelings of well-being, cognitive function, judgment, risk perception, and situation awareness of sleep-deprived aviators consistently better than placebo and without side effects of aeromedical concern. DISCUSSION: Like previous research, this study strongly suggests that both drugs can maintain acceptable levels of mood and performance during sleep deprivation. The results also confirm that modafinil is well tolerated and appears to be a good alternative to dextroamphetamine for countering the debilitating mood and cognitive effects of sleep loss during sustained operations.

Cognition enhancement by modafinil: a meta-analysis.

INTRODUCTION: Currently, there are a number of pharmaceuticals available that have potential to enhance cognitive functioning, some of which may ultimately be considered for such use in military operations. Some drugs with potential for cognition enhancement have already been studied for use in military operations specific to their primary effect in sleep regulation (i.e., dextroamphetamine, modafinil, caffeine). There is considerable information available on many of these drugs. However, considerations for military appropriateness must be based on proficient research (e.g., randomly controlled trial design). METHODS: A meta-analysis was conducted to summarize the current state of knowledge of these potentially cognition-enhancing drugs. The analysis only included studies which met inclusion criteria relevant to military research. RESULTS: The results of the literature review reveal a gap in research of the enhancement properties of the drugs of interest. The results yielded three studies (all of which studied modafinil) that met the criteria. The meta-analysis of these three studies revealed a relatively weak pooled effect of modafinil on some aspects of cognitive performance in normal, rested adults. DISCUSSION: While the results of this study support the efficacy of modafinil, the main finding is the large literature gap evaluating the short- and long-term effects of these drugs in healthy adults.

The arterial switch operation: 25-year experience with 258 patients.

BACKGROUND: At our institution, the arterial switch operation for transposition of the great arteries has transitioned from the Gore-Tex patch (W.L. Gore & Associates, Flagstaff, AZ) for pulmonary artery reconstruction to redundant pantaloon pericardial patch (RPPP). The (U-shaped) coronary artery button was used for coronary reimplantation. This study investigates overall mortality and factors for neopulmonary artery, neoaortic, and coronary artery surgical reintervention. METHODS: We performed a retrospective chart review of all patients who underwent arterial switch between 1983 and 2007. Our surgical database, operative reports, and cardiology clinic charts were reviewed. Time to event was plotted as Kaplan-Meier curves. Predictors of time-to-event were examined using Cox proportional hazard modeling. RESULTS: A total of 258 patients underwent arterial switch during the study. Mortality declined from 15% (era I: 1983 to 1990) to 11% (era II: 1991 to 1998) to 7% (era III: 1999 to 2007). Era III had a significantly later time to death compared with era I (hazard ratio [HR] 0.62, p = 0.04). The RPPP had a lower neopulmonary artery reintervention rate compared with Gore-Tex; 9 of 225 (4%) versus 3 of 21 (14%), p = 0.008. Complex anatomy increased risk for neopulmonary reintervention (HR 3.3, p = 0.03). Surgical reintervention rate for coronary arteries was 2%. Complex coronary anatomy (HR 17.9, p = 0.01) predicted coronary reintervention. Predictors of neoaortic reintervention were prior pulmonary artery band (HR 4.3, p = 0.03), complex anatomy (HR 3.5, p = 0.01), and coronary artery anatomy (HR 3.5, p = 0.04). CONCLUSIONS: Arterial switch operation mortality has decreased. Conversion to RPPP reduced neopulmonary artery reintervention. The (U-shaped) coronary artery button technique is associated with low coronary reintervention rates. Complex coronary anatomy increases coronary and aortic reintervention. Prior pulmonary artery banding and complex anatomy increase aortic reintervention.

Echocardiography in pediatric infective endocarditis.

Transesophageal echocardiography is more sensitive than transthoracic echocardiography (TTE) in detecting endocarditis in adults; however, pediatric data are limited. Retrospectively, 39 subjects with endocarditis were divided into adult-sized (≥60 kg) and pediatric-sized (<60 kg). TTE was 97% sensitive in pediatric-sized subjects but 70% in adult-sized subjects (P < 0.05). TTE is usually sufficient for detection of endocarditis in children <60 kg.

Observed prevalence of congenital heart defects from a surveillance study in China.

OBJECTIVES: The purpose of this study was to estimate the prevalence of major and minor congenital heart defects among fetuses and neonates using sonography in a general population of 4 areas surrounding Shanghai, China. METHODS: Pregnant women were recruited between April 2004 and December 2005 in Jiaxing City, Suzhou City, Changshu County, and Haining County. All participants could have 3 sonographic examinations performed by specially trained physicians regardless of medical indication: a fetal sonographic screen and fetal echocardiography between 20 and 28 weeks' gestation and neonatal echocardiography. Diagnoses of congenital heart defects were made on the basis of review of all available scans by an international group of experts in pediatric cardiology. Prevalence rates were calculated per 1000 births. RESULTS: Among 4006 scanned fetuses and neonates, there were 75 congenital heart defects, including 12 major defects. The observed prevalence for all congenital heart defects was 18.7 (95% confidence interval, 14.8-23.5) per 1000 births, and the prevalence for major defects was 3.0 (95% confidence interval, 1.6-5.2) per 1000 births. The most common defects were ventricular septal defects (n = 47 [62.7%]), atrial septal defects (n = 14 [18.7%]), tetralogy of Fallot (n = 4 [5.3%]), and hypoplastic left heart syndrome (n = 3 [4.0%]). CONCLUSIONS: The prevalence of all congenital heart defects in the 4 areas of China studied was higher than that reported in other countries, with ventricular septal defects being the most frequent defects. Our data likely reflect a better estimate of the total prevalence of congenital heart defects in China than reported previously.

B-type natriuretic peptide and heart failure in patients with ventricular septal defect: a pilot study.

In adults without congenital heart disease, B-type natriuretic peptide (BNP) has been shown to be a very sensitive and specific marker of heart failure. The utility of BNP as a marker of clinical heart failure in children with a ventricular septal defect (VSD) has yet to be determined. A prospective, observational study evaluated BNP levels and other measures of heart failure. Eligible patients were <2 years old, scheduled to undergo surgical repair of a VSD, and without other significant structural heart disease. Data collected before and after surgical repair included echocardiographic measurements, electrocardiographic (ECG) findings, Ross score, BNP measurements, and weight gain. A total of 21 patients were enrolled and 14 patients had complete postoperative follow-up data. For patients with complete data, mean BNP decreased by 94 pg/ml (118 pre vs. 24 post; paired t-test, p = 0.041), mean left ventricular end-diastolic dimension z-score decreased by 1.75 (+0.86 vs. -0.89; paired t-test, p = 0.013), mean weight z-score change per month increased by 0.35 (-0.25 vs. +0.10; Wilcoxon test, p = 0.013), and the incidence of biventricular hypertrophy on ECG decreased (46% vs. 0%; McNemar test, p = 0.031). The change in BNP showed a trend toward a negative correlation with weight z-score change per month (r = -0.531, p = 0.075). In conclusion, BNP, along with other measures of heart failure, decreased following VSD repair, and the change in BNP was most closely correlated with improved weight gain.