Characterization of Two-Pore Channel 2 by Nuclear Membrane Electrophysiology

Lysosomal calcium (Ca2+) release mediated by NAADP triggers signalling cascades that regulate many cellular processes. The identification of two-pore channel 2 (TPC2) as the NAADP receptor advances our understanding of lysosomal Ca2+ signalling, yet the lysosome is not amenable to traditional patch-clamp electrophysiology. Previous attempts to record TPC2 single-channel activity put TPC2 outside its native environment, which not reflect TPC2’s true physiological properties. To test the feasibility of using nuclear membrane electrophysiology for TPC2 channel characterization, we constructed a stable human TPC2-expressing DT40TKO cell line that lacks endogenous InsP3R and RyR (DT40TKO-hTPC2). Immunostaining revealed hTPC2 expression on the ER and nuclear envelope. Intracellular dialysis of NAADP into Fura-2-loaded DT40TKO-hTPC2 cells elicited cytosolic Ca2+ transients, suggesting that hTPC2 was functionally active. Using nuclear membrane electrophysiology, we detected a ~220 pS single-channel current activated by NAADP with K+ as the permeant ion. The detected single-channel recordings displayed a linear current-voltage relationship, were sensitive to Ned-19 inhibition, were biphasically regulated by NAADP concentration, and regulated by PKA phosphorylation. In summary, we developed a cell model for the characterization of the TPC2 channel and the nuclear membrane patch-clamp technique provided an alternative approach to rigorously investigate the electrophysiological properties of TPC2 with minimal manipulation.published_or_final_versio

Prevalence of past or current Hepatitis B infection and factors for non-vaccination in Chinese patients with inflammatory bowel diseases

The Conference program's website is located at http://jsibd.jp/1staocc/program.htmlPoster Oral: PO-46Information on the prevalence and natural history of chronic hepatitis B (HBV) among Asian IBD patients are scarce. Moreover, the prevalence of HBV vaccination coverage in Asian IBD patients remains unknown. AIM: We determined the prevalence and clinical course of current and past HBV infection among Chinese IBD patients. We also determined the proportion of Chinese IBD patients without protective antibody against HBV and factors associated with non-vaccination. METHODS: All patients attending our IBD Clinic had blood tests for viral hepatitis B markers. The prevalence of current and past infection with HBV, and effective HBV vaccination were determined. We also identified for risk factors associated with non-vaccination. RESULTS: A total of 267 Chinese IBD (166 ulcerative colitis and 101 Crohn’s disease) patients were studied. The mean follow up was 10.5 years. Current HBV infection was detected in 6.7% patients whereas 28.5% had evidence of past HBV infection. One hundred and two (38.2%) patients had no detectable anti-HBs antibodies. Multivariate analysis found that young age of diagnosis (OR 1.021; 95% CI 1.00 – 1.04) and the use of thiopurines (OR 0.51; 95%CI 0.29 – 0.91) were associated with absence of anti-HBs. Deranged liver function was detected in 27 (10.1%) IBD patients including three (16.7%) HBsAg-positive patients. The corresponding proportion of patients with liver derangement was 7.9% in patients with past HBV infection, 8.9% in HBsAg-negative patients without anti-HBs and 11.2% in patients with effective HBV vaccination (P = 0.71). CONCLUSION: Current and past infection with HBV was detected in about one-third of Chinese IBD patients. Approximately 40% of IBD patients lacked protective antibody against HBV. The use of thiopurines and young age of diagnosis was associated with non-vaccination among Chinese IBD patients. A more intensive HBV vaccination program with regular monitoring of anti-HBs may be needed in this group of patients.published_or_final_versio

Concurrent comparison of epidemiology, clinical presentation and outcome between adult patients suffering from the pandemic influenza A (H1N1) 2009 virus and the seasonal influenza A virus infection

Purpose of study: The demographics, clinical features and outcome of patients with pandemic influenza A (H1N1) 2009 infection were compared with a concurrent cohort of patients with seasonal influenza A infection. Study design: The clinical and microbiological data of hospitalised adult patients admitted between 29 June and 28 October 2009, with pandemic A (H1N1) 2009 or seasonal influenza A infection, were analysed. Results: A total of 186 patients including 69 pandemic A (H1N1) and 117 seasonal influenza were analysed. The majority (75%) under 50 years of age had pandemic A (H1N1). Compared with seasonal influenza, pandemic A (H1N1) patients were younger (median age 47 years vs 76 years, p<0.001), less likely to have lower respiratory tract symptoms (46.4% vs 66.7%, p=0.007), but more likely to be obese (5.8% vs 0%, p=0.018), pregnant (7.2% vs 0.9%, p=0.027) or have no underlying predisposing factors (24.6% vs 5.1%, p<0.001). Patients with pandemic A (H1N1) were more likely to receive oseltamivir (91.3% vs 40.2%, p<0.001), but less likely to receive antibiotics (75.4% vs 90.6%, p=0.005). Respiratory failure was the reason for intensive care unit admission for all four patients with pandemic A (H1N1), but only for one of three patients with seasonal influenza. There were no statistical significant differences in the rate of intensive care unit admission or death. Conclusions: In addition to age, several clinical parameters were different between pandemic A (H1N1) and seasonal influenza. However, since both seasonal and pandemic influenza can lead to significant morbidity and mortality, the impact of pre-existing seasonal influenza should not be underestimated during the pandemic period.published_or_final_versio

A randomised controlled trial to compare immunogenicity between intramuscular and intradermal trivalent influenza vaccination in nursing home older adults

BACKGROUND: Immunosenescence in older adults contributes to unsatisfactory immunogenicity towards influenza vaccine. Intradermal (ID) administration of influenza vaccine has been suggested to improve immunogenicity but there is no study regarding the immunogenicity of ID influenza vaccination in nursing home older adults ...postprin

Unexpectedly Higher Morbidity and Mortality of Hospitalized Elderly Patients Associated with Rhinovirus Compared with Influenza Virus Respiratory Tract Infection

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A prospective randomized, open-label trial comparing the safety and efficacy of dose sparing intradermal 2010/2011 trivalent influenza vaccine delivered by two different devices

Poster Abstract Session - Influenza Vaccines: no. 533BACKGROUND: We performed intradermal 2010/11 trivalent influenza vaccination (TIV) in adult subjects delivered by two different intradermal (ID) devices, using 20% and 60% of the standard dose and compared the immunogenicity and safety with full dose intramuscular (IM) immunization. METHODS: This is a prospective randomized trial conducted from December 2010 to March 2011, comprising chronically ill adults. Subjects were randomly assigned …postprin

Prevention of nosocomial transmission of norovirus by strategic infection control measures

BACKGROUND. Nosocomial outbreaks of norovirus infection pose a great challenge to the infection control team. METHODS. Between November 1, 2009, and February 28, 2010, strategic infection control measures were implemented in a hospital network. In addition to timely staff education and promotion of directly observed hand hygiene, reverse-transcription polymerase chain reaction for norovirus was performed as an added test by the microbiology laboratory for all fecal specimens irrespective of the request for testing. Laboratory-confirmed cases were followed up by the infection control team for timely intervention. The incidence of hospitalacquired norovirus infection per 1,000 potentially infectious patient-days was compared with the corresponding period in the preceding 12 months, and the incidence in the other 6 hospital networks in Hong Kong was chosen as the concurrent control. Phylogenetic analysis of norovirus isolates was performed. RESULTS. Of the 988 patients who were tested, 242 (25%) were positive for norovirus; 114 (47%) of those 242 patients had norovirus detected by our added test. Compared with the corresponding period in the preceding 12 months, the incidence of hospital-acquired norovirus infection decreased from 131 to 16 cases per 1,000 potentially infectious patient-days (P< .001), although the number of hospitalacquired infections was low in both the study period (n=8) and the historical control periods (n=11). The incidence of hospital-acquired norovirus infection in our hospital network (0.03 cases per 1,000 patient-days) was significantly lower than that of the concurrent control (0.06 cases per 1,000 patient-days) (P=.015). Forty-three (93%) of 46 norovirus isolates sequenced belonged to the genogroup II.4 variant. CONCLUSIONS. Strategic infection control measures with an added test may be useful in controlling nosocomial transmission of norovirus. © 2011 by The Society for Healthcare Epidemiology of America. All rights reserved.published_or_final_versio

Harvesting convalescent plasma for hyperimmune intravenous globulin production: a multicentre randomised double-blind controlled trial for treatment of patients with serious S-OIV H1N1 infection

Poster Presentations: Emerging / Infectious Diseases: abstract no. P107-Ab0089Symposium Theme: Translating Health Research into Policy and Practice for Health of the Populationpublished_or_final_versio