Clinical and genetic profile of congenital long QT syndrome in Hong Kong: a 20-year experience in paediatrics.

INTRODUCTION: Congenital long QT syndrome (LQTS) is a genetically transmitted cardiac channelopathy that can lead to sudden cardiac death. This study aimed to report the clinical and genetic characteristics of all young patients diagnosed with LQTS in the only tertiary paediatric cardiology centre in Hong Kong. METHODS: This is a retrospective review of all paediatric and young adult patients diagnosed at our centre with LQTS from January 1997 to December 2016. The diagnosis of LQTS was established with a corrected QT interval (QTc) ≥480 ms, Schwartz score of >3 points, or the presence of a pathogenic mutation. RESULTS: Fifty-nine patients (33 males) from 52 families were included, with a mean age of 8.17 years (range, 0.00-16.95 years) at presentation. Five patients had concomitant congenital heart diseases. The mean follow-up duration was 5.33 ± 4.65 years. The mean QTc in the cohort was 504 ± 47 ms. They presented with syncope and convulsion (49%), cardiac arrest (10%), bradycardia and neonatal atrioventricular block (12%). Fifteen (25%) patients were asymptomatic at diagnosis. Thirty-eight (64.4%) patients were confirmed to have a pathogenic mutation for LQTS genes. Forty-five (76.3%) patients received beta blocker therapy. Thirteen (22.0%) patients required implantable cardioverter defibrillator. There was no mortality in the study period. The 1-, 5-, and 10-year breakthrough cardiac event-free rates were 93.0%, 80.7%, and 72.6%, respectively. CONCLUSION: Identification of the disorder, administration of beta blockers, and lifestyle modification can prevent subsequent cardiac events in LQTS. Genotyping in patients with LQTS is essential in guiding medical therapy and improving prognosis.

Genetic basis of channelopathies and cardiomyopathies in Hong Kong Chinese patients: a 10-year regional laboratory experience.

INTRODUCTION: Hereditary channelopathies and cardiomyopathies are potentially lethal and are clinically and genetically heterogeneous, involving at least 90 genes. Genetic testing can provide an accurate diagnosis, guide treatment, and enable cascade screening. The genetic basis among the Hong Kong Chinese population is largely unknown. We aimed to report on 28 unrelated patients with positive genetic findings detected from January 2006 to December 2015. METHODS: Sanger sequencing was performed for 28 unrelated patients with a clinical diagnosis of channelopathies or cardiomyopathies, testing for the following genes: KCNQ1,KCNH2,KCNE1,KCNE2, and SCN5A, for long QT syndrome; SCN5A for Brugada syndrome; RYR2 for catecholaminergic polymorphic ventricular tachycardia; MYH7 and MYBPC3 for hypertrophic cardiomyopathy; LMNA for dilated cardiomyopathy; and PKP2 and DSP for arrhythmogenic right ventricular dysplasia/cardiomyopathy. RESULTS: There were 17 males and 11 females; their mean age at diagnosis was 39 years (range, 1-80 years). The major clinical presentations included syncope, palpitations, and abnormal electrocardiography findings. A family history was present in 13 (46%) patients. There were 26 different heterozygous mutations detected, of which six were novel-two in SCN5A (NM_198056.2:c.429del and c.2024-11T>A), two in MYBPC3 (NM_000256.3:c.906-22G>A and c.2105_2106del), and two in LMNA (NM_170707.3:c.73C>A and c.1209_1213dup). CONCLUSIONS: We have characterised the genetic heterogeneity in channelopathies and cardiomyopathies among Hong Kong Chinese patients in a 10-year case series. Correct interpretation of genetic findings is difficult and requires expertise and experience. Caution regarding issues of non-penetrance, variable expressivity, phenotype-genotype correlation, susceptibility risk, and digenic inheritance is necessary for genetic counselling and cascade screening.

TSC1/2 mutations define a molecular subset of HCC with aggressive behaviour and treatment implication.

OBJECTIVE: We investigated the mutational landscape of mammalian target of rapamycin (mTOR) signalling cascade in hepatocellular carcinomas (HCCs) with chronic HBV background, aiming to evaluate and delineate mutation-dependent mechanism of mTOR hyperactivation in hepatocarcinogenesis. DESIGN: We performed next-generation sequencing on human HCC samples and cell line panel. Systematic mutational screening of mTOR pathway-related genes was undertaken and mutant genes were evaluated based on their recurrence. Protein expressions of tuberous sclerosis complex (TSC)1, TSC2 and pRPS6 were assessed by immunohistochemistry in human HCC samples. Rapamycin sensitivity was estimated by colony-formation assay in HCC cell lines and the treatment was further tested using our patient-derived tumour xenograft (PDTX) models. RESULTS: We identified and confirmed multiple mTOR components as recurrently mutated in HBV-associated HCCs. Of significance, we detected frequent (16.2%, n=18/111) mutations of TSC1 and TSC2 genes in the HCC samples. The spectrum of TSC1/2 mutations likely disrupts the endogenous gene functions in suppressing the downstream mTOR activity through different mechanisms and leads to more aggressive tumour behaviour. Mutational disruption of TSC1 and TSC2 was also observed in HCC cell lines and our PDTX models. TSC-mutant cells exhibited reduced colony-forming ability on rapamycin treatment. With the use of biologically relevant TSC2-mutant PDTXs, we demonstrated the therapeutic benefits of the hypersensitivity towards rapamycin treatment. CONCLUSIONS: Taken together, our findings suggest the significance of previously undocumented mutation-dependent mTOR hyperactivation and frequent TSC1/2 mutations in HBV-associated HCCs. They define a molecular subset of HCC having genetic aberrations in mTOR signalling, with potential significance of effective specific drug therapy.

Clinical and genetic profile of catecholaminergic polymorphic ventricular tachycardia in Hong Kong Chinese children.

OBJECTIVE: To report our experience in the management of catecholaminergic polymorphic ventricular tachycardia in Hong Kong Chinese children. METHODS: This case series study was conducted in a tertiary paediatric cardiology centre in Hong Kong. All paediatric patients diagnosed at our centre with catecholaminergic polymorphic ventricular tachycardia from January 2008 to October 2014 were included. RESULTS: Ten patients (five females and five males) were identified. The mean age at presentation and at diagnosis were 11.0 (standard deviation, 2.9) years and 12.5 (2.8) years, respectively. The mean delay time from first presentation to diagnosis was 1.5 (standard deviation, 1.3) years. They presented with recurrent syncope and six patients had a history of aborted cardiac arrest. Four patients were initially misdiagnosed to have epilepsy. Catecholaminergic polymorphic ventricular tachycardia was diagnosed by electrocardiogram at cardiac arrest (n=2), or provocation test, either by catecholamine infusion test (n=6) or exercise test (n=2). Mutations of the RyR2 gene were confirmed in six patients. Nine patients were commenced on beta-blockers after diagnosis. Despite medications, three patients developed aborted or resuscitated cardiac arrest (n=2) and syncope (n=1). Left cardiac sympathetic denervation was performed in five patients and an implantable cardioverter defibrillator was implanted in another. There was no mortality during follow-up. CONCLUSIONS: Catecholaminergic polymorphic ventricular tachycardia should be considered in children who present with recurrent syncope during exercise or emotional stress. Despite beta-blocker treatment, recurrent ventricular arrhythmias occur and may result in cardiac arrest.

Transcatheter ablation of atrioventricular junctional re-entrant tachycardia in children and adolescents in Hong Kong: comparison of cryothermal with radiofrequency energy.

OBJECTIVE: To compare the outcome of cryothermal and radiofrequency energy transcatheter ablation of atrioventricular junctional re-entrant tachycardia in children and adolescents. DESIGN: Case series with internal comparison. SETTING: Two hospitals in Hong Kong. PATIENTS: Consecutive transcatheter ablation procedures for atrioventricular junctional re-entrant tachycardia in children and adolescents in our unit from August 2000 to September 2008 were retrospectively reviewed. Radiofrequency ablation was performed from August 2000 to June 2005, and cryoablation from July 2005 to September 2008. MAIN OUTCOME MEASURES: Demographic data, outcome and procedural details. RESULTS: Thirty-eight procedures were reviewed. The radiofrequency ablation group (n=20) and cryoablation group (n=18) had similar demographic characteristics, except that there were more patients with congenital heart disease in the latter group (P=0.03). Acute procedural success rate was 100% in both groups. One patient from the radiofrequency ablation group had recurrence of atrioventricular junctional re-entrant tachycardia. The frequency of post-ablation persistent heart block was higher in the radiofrequency ablation than cryoablation group (10% vs 0%, P=0.17), but this difference was not statistically significant. A shorter fluoroscopy time was noted in the cryoablation group (31 ± 13 vs 38 ± 18 minutes; P=0.03). CONCLUSIONS: Transcatheter cryoablation for atrioventricular junctional re-entrant tachycardia in children and adolescents is as effective as radiofrequency ablation over the medium term. It has an excellent safety profile in terms of avoiding heart block.

Influence of country of study on student responsiveness to the H1N1 pandemic.

OBJECTIVES: University students, both travelling abroad on holiday or exchange students entering a country, can serve as mobile carriers of infectious diseases during a pandemic, and thus require special attention when considering preventive measures. The objectives of this study were to evaluate student compliance and opinions on preventive measures of a university before and during an H1N1 influenza pandemic, and to explore environmental and behavioural factors that might contribute towards compliance. STUDY DESIGN: Cross-sectional, self-administered questionnaire. METHODS: Local and foreign students attending an international summer school programme were invited to participate in a self-administered survey. RESULTS: Respondents complied with most of the preventive measures, excluding website viewing and mask wearing. Significant differences in compliance and perceived necessity were found amongst students from Singapore, Hong Kong and the USA. Singaporean students were significantly more likely to comply with all measures and consume antiviral medication in response to the pandemic than students studying in the US. CONCLUSIONS: Students' responses towards university pandemic measures were largely positive, but sensitivity towards these measures varied between groups by country of study. This should be considered in further comparative studies.

Monoclonal antibodies to VP1 recognize a broad range of enteroviruses.

Enteroviruses (EVs) are common seasonal viruses that are associated with a variety of diseases. High-quality monoclonal antibodies (MAbs) are needed to improve the accuracy of EV diagnosis in clinical laboratories. In the present study, the full-length VP1 genes of poliovirus 1 (Polio 1) and coxsackievirus B3 (Cox B3) were cloned, and the encoded proteins were expressed and used as antigens in an attempt to raise broad-spectrum MAbs to EVs. Two pan-EV MAbs were isolated: one raised against Polio 1 VP1 and the other against Cox B3 VP1. The binding sites of both pan-EV MAbs were mapped to an amino acid sequence within a conserved region in the N terminus of Polio 1 VP1 by peptide and competition enzyme-linked immunosorbent assay. Two additional MAbs, an EV70-specific MAb and an EV71/Cox A16-bispecific MAb, developed against EV70 and 71 VP1 proteins, were pooled with the two pan-EV MAbs (pan-EV MAb mix) and tested for their sensitivity and specificity in the staining of various virus-infected cells. The pan-EV MAb mix detected all 40 prototype EVs tested and showed no cross-reactivity to 18 different non-EV human viruses. Compared with two commercially available EV tests, the pan-EV MAb mix exhibited higher specificity than one test and broader spectrum reactivity than the other. Thus, our study demonstrates that full-length Polio 1 VP1 and Cox B3 VP1 can serve as effective antigens for developing a pan-EV MAb and that the pan-EV MAb mix can be used for the laboratory diagnosis of a wide range of EV infections.

Excretion of human immunodeficiency virus type 1 through polarized epithelium by immunoglobulin A.

Human immunodeficiency virus (HIV) is transmitted primarily sexually across mucosal surfaces. After infection, HIV propagates initially in the lamina propria below the polarized epithelium and causes extensive destruction of mucosal T cells. Immunoglobulin A (IgA) antibodies, produced in the lamina propria and then transcytosed across the mucosal epithelium into the lumen, can be the first line of immune defense against HIV. Here, we used IgA monoclonal antibodies against HIV envelope proteins to investigate the abilities of polarized primate and human epithelial cells to excrete HIV virions from the basolateral to the apical surface via polymeric Ig receptor (pIgR)-mediated binding and the internalization of HIV-IgA immune complexes. African green monkey kidney cells expressing pIgR demonstrated HIV excretion that was dependent on the IgA concentration and the exposure time. Matched IgG antibodies with the same variable regions as the IgA antibodies and IgA antibodies to non-HIV antigens had no HIV excretory function. A mixture of two IgA anti-bodies against gp120 and gp41 showed a synergistic increase in the level of HIV excreted. The capacity for HIV excretion correlated with the ability of IgA antibodies to bind HIV and of the resulting immune complexes to bind pIgR. Consistent with the epithelial transcytosis of HIV-IgA immune complexes, the colocalization of HIV proteins and HIV-specific IgA was detected intracellularly by confocal microscopy. Our results suggest the potential of IgA antibodies to excrete HIV from mucosal lamina propria, thereby decreasing the viral burden, access to susceptible cells, and the chronic activation of the immune system.

Multiple introductions of methicillin-resistant Staphylococcus aureus ST612 into Western Australia associated both with human and equine reservoirs.

Staphylococcus aureus is a serious human and animal pathogen. Multilocus sequence type 612 (ST612) is the dominant methicillin-resistant S. aureus (MRSA) clone in certain South African hospitals and is sporadically isolated from horses and horse-associated veterinarians in Australia. Colonisation and infection by ST612-MRSA is increasing in Western Australia. Whole-genome sequencing was performed for 51 isolates of ST612-MRSA from Western Australian patients and healthcare workers, South African hospital patients, Australian veterinarians and New South Wales horses. Core genome phylogenies suggested that Australian equine and veterinarian-associated ST612-MRSA were monophyletic. Individual Western Australian isolates grouped either with this equine-associated lineage or more diverse lineages related to those in South African hospitals. Bioinformatic analyses of the complete ST612-MRSA reference genome SVH7513 confirmed that ST612-MRSA was closely related to ST8 USA500 MRSA. Common use of rifampicin in South Africa and equine veterinarian practice may favour ST612-MRSA in these settings. Humans and horses colonised with ST612-MRSA are potential reservoirs for MRSA in Australia.

Calu-3/A-549 mixed cells as a replacement for primary rhesus monkey kidney cells for virus detection.

BACKGROUND: Primary kidney cells derived from rhesus macaques (pRhMK) are heavily relied upon for the detection and culture of a wide range of clinically relevant viruses. The use of these cultures is problematic due to the possible presence of endogenous viruses, the need to sacrifice a primate, and the inherent variance found in primary cultures. OBJECTIVE: To develop a continuous cell line or mixed cell co-culture that could replace dependence on pRhMK cells. STUDY DESIGN: Cells from the Calu-3 and A-549 cell lines were used to prepare mixed cell monolayers that were compared to pRhMK cells for their ability to detect respiratory viruses, measles, mumps, enteroviruses, and herpes viruses. Clinically derived and laboratory virus strains were used for these comparisons in culture plates or 16 mm tubes. RESULTS: Calu-3/A-549 cells are more sensitive than pRhMK for the detection of adenovirus, enteroviruses and herpes simplex virus and are about equally sensitive for the detection of other respiratory viruses, measles, mumps and varicella-zoster virus. CONCLUSIONS: Calu-3/A-549 cells are an equivalent or better alternative to pRhMK cells for the detection of many clinically relevant viruses.

Evidence of human bocavirus circulating in children and adults, Cleveland, Ohio.

BACKGROUND: Viral respiratory illness is a major cause of morbidity and mortality. The human bocavirus (HBoV) is a recently recognized parvovirus isolated from human respiratory secretions. OBJECTIVES: To define the clinical and epidemiologic characteristics in adult and pediatric patients with evidence of HBoV. STUDY DESIGN: From October 2005 through October 2006, we screened respiratory samples from children and adults negative for common respiratory pathogens for HBoV by PCR. Demographic and clinical characteristics were obtained from medical records of HBoV positive individuals. RESULTS: Of 2075 samples screened, 1826 (88.0%) represented distinct respiratory events: 1539 (84.3%) were pediatric (<18 years), and 273 (15.0%) adult (> or =18 years). Forty (2.2%) patients had HBoV: 36 (2.3%) children and 4 (1.5%) adults. HBoV positive children had history of prematurity (31.3%) and cardiac disease (18.8%). Adults had underlying pulmonary (100%) and cardiac (50%) disease. Twenty-seven children (84.4%) were hospitalized; 9 (28.1%) required intensive care. All adults were hospitalized; none required intensive care. Nosocomial acquisition likely occurred in 3 patients. CONCLUSIONS: HBoV circulates in Cleveland, OH, in children and adults with similar frequencies, and can warrant hospitalization and intensive care. Further study would clarify our understanding of this newly recognized human pathogen.

Randomized Trial to Compare Renal Function and Ductal Response between Indomethacin and Ibuprofen Treatment in Extremely Low Birth Weight Infants.

BACKGROUND: A head to head comparison study on renal function and ductal response between indomethacin and ibuprofen has rarely been conducted in extremely low birth weight (ELBW) infants. OBJECTIVES: The aim was to compare renal function and ductal response between indomethacin and ibuprofen in ELBW infants. METHODS: We performed a double-blind randomized control trial to compare renal function and ductal response between indomethacin (0.2, 0.1, and 0.1 mg/kg i.v. every 24 h for 3 doses) and ibuprofen lysine (10, 5, and 5 mg/kg i.v. every 24 h for 3 doses) in ELBW infants with significant hemodynamic patent ductus arteriosus (cardiovascular dysfunction score >3 and LA/AO ratio ≥1.3). RESULTS: A total of 144 infants were enrolled: 73 received indomethacin and 71 received ibuprofen lysine. Significant decreases in urine output were seen in 30 infants (41%) in the indomethacin group and 15 (21%) in the ibuprofen group (p = 0.02). The indomethacin group was associated with a significantly higher chance of persistent ductal response than the ibuprofen group (66 vs. 49%, p = 0.046), but with a lower glomerular filtration rate on day 1, higher serum creatinine on days 1, 2, and 7, and lower urinary prostaglandin on days 2-7. Both groups were comparable in mortality and in bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, and retinopathy of prematurity morbidity. CONCLUSIONS: With the current dosage, ibuprofen had fewer renal side effects but was associated with a lower rate of persistent ductal closure in ELBW infants. The precise role of prostaglandin on renal tubular function in ELBW infants remains to be further investigated.

Surgical therapy for atrial tachycardia in adults.

Eighteen adult patients with atrial tachycardia refractory to treatment with a mean of four drugs underwent attempted surgical cure. Atrial tachycardia originated in the right atrium in 17 patients and the left atrium in 1 patient. Tachycardia could be reproducibly induced and terminated by atrial extrastimuli or atrial pacing in 8 patients (44%). Resection of the arrhythmogenic area was performed in 16 patients (89%), and an isolation procedure was performed in 1 patient. In seven cases (39%), the area of isolation or excision included the sinoatrial node. One patient underwent His bundle section because the arrhythmogenic region was too close to the atrioventricular (AV) conduction system to enable resection. The mean duration of clinical follow-up was 56 +/- 34 months. Clinical tachycardia recurred in five patients (28%), but in two patients it did not recur until greater than 1 year after surgery. A permanent pacemaker was implanted in 3 (18%) of the 17 patients whose His-Purkinje system was left intact. One other patient had required permanent pacing before surgery. Only one of the seven patients undergoing sinoatrial node resection or isolation required permanent pacing for symptomatic bradycardia. Apart from the requirement for permanent pacing, no significant complications occurred. Surgical therapy for atrial tachycardia is a safe procedure, but the rate of cure appears to be less than that of supraventricular tachycardias associated with accessory AV connections. Excision or isolation of the sinoatrial node does not necessitate permanent pacing in most patients.

Enhancement of cytomegalovirus detection in mink lung cells using CMV Turbo.

BACKGROUND: Detection of HCMV from clinical specimens was a slow process until the development of shell vial method with staining for immediate early antigen (IEA). Culture though still considered insensitive is widely used for other than blood samples. A method to improve culture sensitivity is desirable. OBJECTIVES: TurboTreat, a CMV pretreatment medium from Diagnostic Hybrids Inc., was evaluated on Mv1Lu, R-Mix and MRC-5 cells for improved sensitivity for HCMV detection. STUDY DESIGN: Monolayers of Mv1Lu, R-Mix and MRC-5 cells in 48-well plates were treated with TurboTreat for overnight (o/n), 4 h or left untreated and then inoculated with previously positive HCMV specimens. After o/n incubation, cells were fixed, stained and positive cells counted. RESULTS: CMV TurboTreat enhanced detection 2-3-fold after 4 h treatment and 4-6-fold after o/n treatment in Mv1Lu and R-Mix cells and to a lesser extend in MRC-5 cells with clinical isolates of HCMV. With frozen clinical specimens, Mv1Lu cells treated o/n, 4 h or untreated detected 23, 21 and 15 positive specimens, respectively. R-Mix cells detected 19, 18, and 14 positives, respectively and MRC-5 cells detected 16, 15 and 15 positives, respectively. In no case was a positive detected in another cell line regardless of treatment that was not detected in Mv1Lu treated o/n. CONCLUSION: The o/n pretreatment with CMV TurboTreat on Mv1Lu cells is the optimum condition of treatment and significantly enhanced the detection of HCMV. Even 4 h pretreatment of Mv1Lu cells showed significant enhancement over untreated Mv1Lu, R-Mix and MRC-5 cells. Pretreatment of Mv1Lu cells with CMV TurboTreat for 4 h or longer increased the sensitivity of rapid HCMV detection.

Simultaneous pancreas and kidney transplant rejection: separate or synchronous events?

The results of simultaneous pancreas and kidney transplantation (SPK) cannot be matched by pancreas transplantation alone (PTA), in part because an independent diagnosis of pancreas graft rejection remains difficult. The relationship between rejection of the pancreas and rejection of the kidney is poorly understood, and it is not known whether simultaneous transplantation of both organs confers true protection to either graft. To study these questions, reliable canine allotransplant models of kidney transplantation alone (KTA), PTA, and SPK were established. Sixty-seven mongrel dogs received KTA (n=21), PTA (n=23), or SPK (n=23) with either no immunosuppression, low-dose cyclosporine (CsA)-based immunosuppression, or high-dose CsA-based immunosuppression. Needle core biopsy (NCB) and fine needle aspiration biopsy (FNAB) were performed at 0, 2, 4, 7, 9, 11, 14, 21, and 30 days or at the time of graft failure. Pancreas and kidney graft survival after SPK was significantly shorter in dogs given low-dose CsA than in dogs given high-dose CsA (pancreas, P<0.04; kidney, P<0.03). Concurrent NCBs and FNABs were performed on 227 occasions in pancreas grafts and 229 occasions in kidney grafts. The time to initial evidence of rejection by NCB was not different in any immunosuppressed group. Synchronous rejection occurred in 73% of immunosuppressed SPK biopsies. Kidney-only rejection occurred in 23% of biopsies and pancreas-only rejection occurred in only 3% after SPK. All markers of pancreas graft rejection were poor, with the most sensitive being NCB of the simultaneously transplanted kidney. In summary, recipients of SPK required more immunosuppression than recipients of PTA, and improved PTA survival should be achievable with more sensitive markers of rejection. Markers of kidney rejection were the most sensitive indicators of pancreas rejection, and independent pancreas rejection was uncommon after SPK.

Surgical validation and implications for transcatheter closure of quantitative echocardiographic evaluation of atrial septal defect.

Accurate evaluation of secundum atrial septal defect (ASD) is important for the success of transcatheter closure. The purpose of this study was (1) to describe a quantitative evaluation by transthoracic (TTE) and transesophageal (TEE) echocardiography of the various morphologic features of ASD that might be important for patient selection for transcatheter closure, and (2) to assess the reliability of these 2 methods by surgical findings. Preoperative TTE and TEE were used to evaluate the ASD of 27 children undergoing surgical closure. Measurements included the diameters of ASD and the atrial septal lengths in the transverse and longitudinal axis, and the width of the superior, inferior, anteroinferior, and posterior septal margins. The shape and location of the ASD and the adequacy of the septal margins for anchoring occluding devices were determined. Echocardiographic data were compared with corresponding surgical measurements. No significant difference occurred in the means of all the parameters measured with the 3 methods, except for the transverse ASD diameter (p <0.05). Good agreement occurred between TTE and TEE and surgical data, except for the transverse ASD diameter, transverse atrial septal length, and the posterior septal margin on TTE. Intraclass correlations between TTE and TEE and surgical measurements of all parameters were good, except for the transverse ASD diameter. The accuracy in determining shape and location of the ASD by TTE and TEE were 100%, whereas that for determining the adequacy of septal margins was 98% and 97%, respectively. In conclusion, TTE and TEE are reliable methods for quantitative evaluation of ASD.

Analysis of indications for surgical closure of subarterial ventricular septal defect without associated aortic cusp prolapse and aortic regurgitation.

Subarterial ventricular septal defect (VSD) is relatively common in Orientals. We reviewed the outcome of 214 patients (137 males) who were followed for 8.6 +/- 5.2 years (range 0.1 to 24.3) and addressed the issue regarding the necessity and optimum timing of closing subarterial defects before development of aortic valve deformities. Demographic data, transthoracic and transesophageal echocardiographic findings, cardiac catheterization results, and operative findings were reviewed. Kaplan-Meier actuarial analysis was performed to assess the development of aortic valve complications over time. Seventy-five patients with heart failure and pulmonary hypertension underwent surgical closure of VSD at the age of 2.4 +/- 2.9 years. No patient had aortic cusp prolapse before operation and none developed aortic cusp prolapse or aortic regurgitation (AR) on follow-up. In contrast, of the 139 asymptomatic patients managed conservatively, 102 (73%) developed aortic cusp prolapse, 78% of whom (80 of 102) developed AR. The prevalence of aortic cusp prolapse and AR at 1, 5, 10, and 15 years old was 8%, 30%, 64%, and 83%, and 3%, 24%, 45%, and 64%, respectively. Significant prolapse or AR prompted surgical closure of VSD with (n = 22) or without (n = 26) valvoplasty in 48 of 102 patients (47%). The size of the VSD was significantly larger in patients with heart failure (9.6 +/- 3.3 mm) or aortic cusp prolapse (11.7 +/- 4.1 mm) compared with those without heart failure (4.5 +/- 1.4 mm, p <0.001). All patients with aortic cusp prolapse and all but 1 with heart failure had a defect size of > or =5 mm. In conclusion, subarterial VSD of > or =5 mm should be closed as early as possible to prevent development of aortic cusp prolapse and AR. Asymptomatic patients with small defects <5 mm could be managed conservatively.

CV-1 and MRC-5 mixed cells for simultaneous detection of herpes simplex viruses and varicella zoster virus in skin lesions.

BACKGROUND: Culture for varicella zoster virus (VZV) is relatively insensitive. Herpes simplex viruses (HSV) culture methods, which rely on primary rabbit kidney (pRK), mink lung (Mv1Lu) or the ELVIS HSV culture system fail to detect VZV. Culture of atypical vesicular skin lesions should be able to detect both HSV and VZV. OBJECTIVES: In this study, we evaluated the sensitivity of a newly developed mixture of CV-1/MRC-5 cells for the concurrent detection of both HSV and VZV. STUDY DESIGN: The CV-1/MRC-5 mixed cells were compared with pRK cells and Mv1Lu cells for the detection of HSV and to MRC-5 and A-549 cells for the detection of VZV. Fresh clinical samples submitted for HSV culture, VZV culture, and/or direct immunofluorescent assay (DFA) as well as frozen clinical samples previously positive for VZV were used for these comparisons. RESULTS: This preliminary study suggest that CV-1/MRC-5 mixed cells are as sensitive as pRK and Mv1Lu cells for the detection of HSV and appear to be more sensitive than MRC-5 and A-549 cells for the detection of VZV. Although the sample size is small, pre-CPE staining with VZV specific monoclonal antibody (Mab) at day 2 post-inoculation may provide a rapid detection of VZV with these mixed cells, but not with MRC-5 or A549 cells. In addition, culture of VZV in mixed cells from fresh clinical specimens appears to be as sensitive as antigen detection by DFA. Finally, 1% of specimens from skin lesions submitted for HSV culture grew VZV, highlighting the importance of culturing for both VZV and HSV, particularly in the case of atypical lesions. CONCLUSION: CV-1/MRC-5 mixed cells are highly sensitive for the simultaneous culture of HSV and VZV. The ability to detect either HSV or VZV from skin lesions is important for patient management.