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Introduction: Communication failings may compromise the diagnostic process and pose a risk to quality of care and patient safety. With a focus on emergency care settings, this project aims to examine the critical role and impact of communication in the diagnostic process, including in diagnosis-related health and research policy, and diagnostic patient-clinician interactions in emergency departments (EDs)., Methods and Analysis: This project uses a qualitatively driven multimethod design integrating findings from two research studies to gain a comprehensive understanding of the impact of context and communication on diagnostic excellence from diverse perspectives. Study 1 will map the diagnostic policy and practice landscape in Australia, New Zealand and the USA through qualitative expert interviews and policy analysis. Study 2 will investigate the communication of uncertainty in diagnostic interactions through a qualitative ethnography of two metropolitan Australian ED sites incorporating observations, field notes, video-recorded interactions, semistructured interviews and written medical documentation, including linguistic analysis of recorded diagnostic interactions and written documentation. This study will also feature a description of clinician, patient and carer perspectives on, and involvement in, interpersonal diagnostic interactions and will provide crucial new insights into the impact of communicating diagnostic uncertainty for these groups. Project-spanning patient and stakeholder involvement strategies will build research capacity among healthcare consumers via educational workshops, engage with community stakeholders in analysis and build consensus among stakeholders., Ethics and Dissemination: The project has received ethical approvals from the Human Research Ethics Committee at ACT Health, Northern Sydney Local Health District and the Australian National University. Findings will be disseminated to academic peers, clinicians and healthcare consumers, health policy-makers and the general public, using local and international academic and consumer channels (journals, evidence briefs and conferences) and outreach activities (workshops and seminars)., Competing Interests: Competing interests: JM is a member of the Council of Education of the Australasian College for Emergency Medicine., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Aim: To improve the effectiveness of nursing clinical handover through a qualitative, tailored communication intervention., Design: A multisite before and after intervention using qualitative ethnography combined with discourse analysis of nursing handover interactions., Methods: We implemented a tailored ward-based intervention to redesign nursing handover practice with co-constructed recommendations for organisational and cultural change on seven wards across three affiliated metropolitan hospitals between February 2020 and November 2022. The intervention was informed by pre-implementation interviews and focus groups with nursing, medical and allied health staff and patients (n = 151) and observed and/or audio-recorded handover events (n = 233). Post-intervention we conducted interviews and focus groups (n = 79) and observed and/or audio-recorded handover events (n = 129) to qualitatively evaluate impact., Results: Our translational approach resulted in substantial changes post-intervention. Nurses conducted more shift-to-shift handovers at the bedside, with greater patient interaction and better structured and more comprehensive information transfer, supported by revised handover documentation. Redesigned group handovers were focused and efficient, communicating critical patient information., Conclusion: Contextualised training combined with changes to ward-level systemic factors impeding communication results in improved nursing handovers. Practice change requires strong executive leadership and project governance, combined with effective ward-level leadership, collaboration and mentoring. The speed and degree of change post-intervention demonstrates the power of interdisciplinary collaborative research between hospital executive, ward leadership and communication specialists., Relevance to Clinical Practice: Nurses are more likely to conduct efficient group handovers and informative, patient-centred bedside handovers in line with policy when they understand the value of handover and have practical strategies to support communication. Communication training should be combined with broader ward-level changes to handover practice tailored to the ward context. A multilevel approach results in more effective practice change., Reporting Method: We adhered to the COREQ guidelines., Patient or Public Contribution: We interviewed patients on study wards pre and post intervention., (© 2024 The Authors. Journal of Clinical Nursing published by John Wiley & Sons Ltd.)

Objective: To describe and analyse the perspectives and communication practices of kidney clinicians and older patients (aged 60 +) during collaborative education and decision-making about dialysis., Methods: This qualitative study drew on pluralistic data sources and analytical approaches investigating elicited semi-structured interviews (n = 31) with doctors (n = 8), nurses (n = 8) and patients (n = 15), combined with ethnographic observations, written artefacts and audio-recorded naturally-occurring interactions (n = 23, education sessions n = 4; consultations n = 19) in a tertiary Australian kidney outpatient clinic. Data were analysed for themes and linguistic discourse features., Results: Five themes were identified across all data sources: 1) lost opportunity in education; 2) persistent disease knowledge gaps; 3) putting up with dialysis; 4) perceived and real involvement in decision-making and 5) complex role of family as decision-making brokers., Conclusion: As the first study to complement interviews with evidence from naturally-occurring kidney interactions, this study balances the perspectives of how older patients and their clinicians view chronic kidney disease education, with how decision-making about dialysis is reflected in practice., Practice Implications: The study provides suggestions for contextualized, multi-perspectives formal and informal training for improving decision-making about dialysis, spanning from indications to boost communication efficiency, to reducing unexplained jargon, incorporating patient navigators and exploring different dialysis modalities., Competing Interests: Declaration of Competing Interest The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: Universal admission screening and follow-up symptom-based testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may play critical roles in controlling nosocomial transmission. We describe the performance of test strategies for inpatients and their companions during various disease incidences in Taiwan., Design: Retrospective population-based cohort study., Setting: The study was conducted across 476 hospitals in Taiwan., Methods: The data for both testing strategies by reverse transcription-polymerase chain reaction for SARS-CoV-2 in newly admitted patients and their companions during May 2021-June 2022 were extracted and analyzed., Results: The positivity rate of universal admission screening was 0.76% (14,640 of 1,928,676) for patients and 0.37% (5,372 of 1,438,944) for companions. The weekly community incidences of period 1 (May 2021-June 2021), period 2 (July 2021-March 2022), and period 3 (April 2022-June 2022) were 6.57, 0.27, and 1,261, respectively, per 100,000 population. The positivity rates of universal admission screening for patients and companions (4.39% and 2.18%) in period 3 were higher than those in periods 1 (0.29% and 0.04%) and 2 (0.03% and 0.003%) (all P < .01). Among the 22,201 confirmed cases, 9.86% were identified by symptom-based testing. The costs and potential savings of universal admission screening for patients and companions achieved a breakeven point when the test strategy was implemented in a period with weekly community incidences of 27 and 358 per 100,000 population, respectively., Conclusions: Universal admission screening and follow-up symptom-based testing is important for reducing nosocomial transmission. Implementing universal admission screening at an appropriate time would balance the benefits with costs and potential unintended harms.

Background: Effective interpersonal communication is critical for shared decision-making (SDM). Previous SDM communication training in nephrology has lacked context-specific evidence from ethnographic analysis of SDM interactions with older patients considering treatment options of end stage kidney disease (ESKD). This study explores communication strategies in SDM discussions in nephrology, specifically focusing on older patients considering dialysis as kidney replacement therapy (KRT)., Methods: We conducted a qualitative study analysing naturally-occurring audio-recorded clinical interactions (n = 12) between Australian kidney doctors, patients aged 60+, and carers. Linguistic ethnography and qualitative socially-oriented functional approaches were used for analysis., Results: Two types of communication strategies emerged: (1) Managing and advancing treatment decisions: involving active checking of knowledge, clear explanations of options, and local issue resolution. (2) Pulling back: Deferring or delaying decisions through mixed messaging. Specifically for non-English speaking patients, pulling back was further characterised by communication challenges deferring decision-making including ineffective issue management, and reliance on family as interpreters. Age was not an explicit topic of discussion among participants when it came to making decisions about KRT but was highly relevant to treatment decision-making. Doctors appeared reluctant to broach non-dialysis conservative management, even when it appears clinically appropriate. Conservative care, an alternative to KRT suitable for older patients with co-morbidities, was only explicitly discussed when prompted by patients or carers., Conclusions: The findings highlight the impact of different communication strategies on SDM discussions in nephrology. This study calls for linguistic-informed contextualised communication training and provides foundational evidence for nephrology-specific communication skills training in SDM for KRT among older patients. There is urgent need for doctors to become confident and competent in discussing non-dialysis conservative management. Further international research should explore naturally-occurring SDM interactions in nephrology with other vulnerable groups to enhance evidence and training integration., (© 2023. The Author(s).)

Background/purpose: Long-term care facilities (LTCFs) are high-risk settings for the novel coronavirus disease (COVID-19). The aim of the study was to describe the extent and the impacts of 2021 COVID-19 outbreaks on LTCFs in Taiwan., Methods: We retrospectively analyzed the data of each COVID-19 outbreak in LTCFs from May 15 to July 31, 2021 in Taiwan. We characterized the features of LTCFs with outbreaks and compared the characteristics of infected staff members and residents of the affected LTCFs., Results: COVID-19 outbreaks were reported in 16 LTCFs (0.9%). The outbreak was significantly associated with LTCFs with ≥50 beds [adjusted odds ratio (aOR), 6.3; 95%confidence interval [CI], 1.9-21.1] and location of Taipei metropolitan area (aOR, 4.6; 95%CI, 1.7-12.8). Resident cases accounted for 75.4% (203/269) of confirmed cases affected by outbreaks. The 30-day all-cause mortality was 24.2% for residents only and was significantly associated with age ≥65 years [adjusted hazard ratio (aHR, 4.3; 95%CI, 1.7-10.5)], presence of symptoms on diagnosis (aHR, 2.2; 95%CI, 1.3-3.7), and LTCF occupancy rate ≥80% (aHR, 3.0, 95%CI, 1.3-7.4)., Conclusion: COVID-19 outbreaks have a critical impact on residents in LTCFs owing to the advanced age and high prevalence of chronic comorbidities in this population. Multi-pronged infection control measures and mass testing are vital for mitigating COVID-19 transmission in LTCFs., Competing Interests: Declaration of competing interest All authors declare no conflicts of interest to disclose., (Copyright © 2023 Formosan Medical Association. Published by Elsevier B.V. All rights reserved.)

Background: Central line-associated bloodstream infection (CLABSI) surveillance data are voluntarily submitted to the Taiwan Healthcare-associated Infection and Antimicrobial Resistance Surveillance (THAS) System. Validation of the CLABSI data is important to ensure the quality of surveillance data. We aimed to validate the CLABSI surveillance data reported to the THAS system., Methods: This study was a retrospective medical record review of patients with positive blood cultures admitted to the intensive care units (ICUs) of 13 participating hospitals between October and December 2021. An external validation team was convened to perform the validation process according to the standardised protocol and to record the reasons for misclassification., Discussion: During the study period, 688 patients with 1,238 positive blood cultures from 59 ICUs at 13 hospitals were evaluated. Among the 185 potential CLABSI events which met the THAS definition by either the external reviewers or the hospital reviewers, 24 (13.0%) events were identified by only the external reviewers, and six (3.2%) were identified by only the hospital reviewers, with an agreement rate of 83.8%. Using external reviewers as the gold standard, the pooled mean sensitivity and positive predictive value of CLABSI reporting were 86.6% (155/179) and 96.3% (155/161), respectively. Among the 37 misclassification episodes, missed case findings were the most common reason for misclassification ( N= 16, 43.2%)., Conclusions: The CLABSI data reported to the THAS system are generally reliable. This study showed the need for ongoing validation processes and quality improvement to maintain the accuracy and validity of the surveillance data., (© 2023 The Authors.)

Background: Carbapenem resistance is perceived as a clinical challenge in the management of debilitated and immunocompromised patients who eventually will die from underlying diseases. We aimed to examine whether carbapenem resistance per se, rather than the underlying diseases, negatively affect outcomes, by comparing the excess mortality and morbidity from healthcare-associated infections (HAIs) caused by carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-susceptible A. baumannii (CSAB)., Methods: This was a nationwide retrospective matched cohort study of hospitalized patients in 96 hospitals which participated in Taiwan Nosocomial Infection Surveillance (TNIS). A total of 2,213 patients with A. baumannii HAIs were individually matched to 4,426 patients without HAIs. Main outcomes were excess risks for one-year all-cause mortality and one-year new-onset chronic ventilator dependence or dialysis-dependent end-stage renal disease., Results: Excess one-year mortality was 27.2% in CRAB patients, compared with their matched uninfected inpatients, as well as 15.4% in CSAB patients (also compared with their matched uninfected inpatients), resulting in an attributable mortality of 11.8% (P <0.001) associated with carbapenem resistance. The excess risk associated with carbapenem resistance for new-onset chronic ventilator dependence was 5.2% (P <0.001). Carbapenem resistance was also associated with an extra cost of $2,511 per case of A. baumannii HAIs (P <0.001)., Conclusion: Carbapenem resistance is associated with a significant disease burden in terms of excess mortality, long-term ventilator dependence, and medical cost. Further studies on effects of antimicrobial stewardship programs in decreasing this burden are warranted., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Su et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Healthcare-associated coronavirus disease 2019 (COVID-19) has significant implications for patients, their companions and healthcare workers (HCWs). Controlling transmission in healthcare settings is critical to reduce deaths due to COVID-19., Aim: To describe the epidemiology and characteristics of healthcare-associated COVID-19 outbreaks and outbreak-related cases., Methods: The investigation data for each healthcare-associated outbreak that occurred between 15 th January 2020 and 31 st July 2021 in Taiwan were analysed retrospectively. Confirmed outbreak-associated cases were categorized as HCW cases, patient companion cases or patient cases, and the characteristics of the confirmed cases were compared between these categories., Findings: In total, 54 healthcare-associated COVID-19 outbreaks including 512 confirmed cases were reported. The median number of affected cases per outbreak was six [interquartile range (IQR) 2-12], and the median outbreak duration was 12 days (IQR 4.3-17.0). Only 5.7% and 0.2% of all confirmed cases were partially and fully vaccinated, respectively. Most outbreaks (90%, 48/54) occurred in May and June 2021. HCW cases, companion cases and patient cases accounted for 19.5%, 41.2% and 39.3% of the total cases. Patient cases were significantly older (median age 72 years, IQR 61-83) and had higher 30-day all-cause mortality (37.4%) than HCW cases (median age 41 years, IQR 28-58, 0%) and companion cases (median age 52 years; IQR 42-62, 1%)., Conclusion: Healthcare-associated COVID-19 outbreaks have a critical impact on patients. Nevertheless, two-thirds of cases in the healthcare-associated outbreaks in this study comprised HCWs and companions. In order to effectively mitigate COVID-19 transmission in healthcare settings, multi-pronged infection prevention and control measures should be implemented and tailored for these three groups., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

In this study, the enhanced solubilization performance of a poorly soluble drug, beclomethasone dipropionate (BDP), was investigated using hydroxypropyl-β-cyclodextrin (HP-β-CD) and ethanol. The enhanced solubility of the drug was determined using the phase solubility method and correlated as a function of both HP-β-CD and ethanol concentrations. The effective progress of drug solubility originated from the formation of cyclodextrin and BDP inclusion complexes and increase in the lipophilicity of the medium, by aqueous ethanol, for hydrophobic BDP. BDP and HP-β-CD composite particles were produced using supercritical assisted atomization (SAA) with carbon dioxide as the spraying medium, 54.2% ( w/w ) aqueous ethanol as the solvent, and an optimal amount of the dispersion enhancer leucine. The effect of the mass ratio of HP-β-CD to BDP ( Z ) on the in vitro aerosolization and in vitro dissolution performance of BDP-HP-β-CD composite particles was evaluated. The aerosolization performance showed that the fine particles fraction ( FPF ) of the composite particles increased with increasing mass ratio. The water-soluble excipient (HP-β-CD) effectively enhance the dissolution rate of BDP from composite particles. This study suggests that BDP-HP-β-CD composite particles produced using SAA can be employed in immediate-release drug formulations for pulmonary delivery.

Highly sensitive X-ray detection is crucial in, for example, medical imaging and secure inspection. Halide perovskite X-ray detectors are promising candidates for detecting highly energetic radiation. In this report, we describe vacuum-deposited Cs-based perovskite X-ray detectors possessing a p-i-n architecture. Because of the built-in potential of the p-i-n structure, these perovskite X-ray detectors were capable of efficient charge collection and displayed an exceptionally high X-ray sensitivity (1.2 C Gy air -1 cm -3 ) under self-powered, zero-bias conditions. We ascribe the outstanding X-ray sensitivity of the vacuum-deposited CsPbI 2 Br devices to their prominent charge carrier mobility. Moreover, these devices functioned with a lowest detection limit of 25.69 nGy air s -1 and possessed excellent stability after exposure to over 3000 times the total dose of a chest X-ray image. For comparison, we also prepared traditional spin-coated CH 3 NH 3 -based perovskite devices having a similar device architecture. Their volume sensitivity was only one-fifth of that of the vacuum-deposited CsPbI 2 Br devices. Thus, all-vacuum deposition appears to be a new strategy for developing perovskite X-ray detectors; with a high practical deposition rate, a balance can be reached between the thickness of the absorbing layer and the fabrication time.

Aims: To increase the quality and safety of patient care, many hospitals have mandated that nursing clinical handover occur at the patient's bedside. This study aims to improve the patient-centredness of nursing handover by addressing the communication challenges of bedside handover and the organizational and cultural practices that shape handover., Design: Qualitative linguistic ethnographic design combining discourse analysis of actual handover interactions and interviews and focus groups before and after a tailored intervention., Methods: Pre-intervention we conducted interviews with nursing, medical and allied health staff (n = 14) and focus groups with nurses and students (n = 13) in one hospital's Rehabilitation ward. We recorded handovers (n = 16) and multidisciplinary team huddles (n = 3). An intervention of communication training and recommendations for organizational and cultural change was delivered to staff and championed by ward management. After the intervention we interviewed nurses and recorded and analyzed handovers. Data were collected from February to August 2020. Ward management collected hospital-acquired complication data., Results: Notable changes post-intervention included a shift to involve patients in bedside handovers, improved ward-level communication and culture, and an associated decrease in reported hospital-acquired complications., Conclusions: Effective change in handover practices is achieved through communication training combined with redesign of local practices inhibiting patient-centred handovers. Strong leadership to champion change, ongoing mentoring and reinforcement of new practices, and collaboration with nurses throughout the change process were critical to success., Impact: Ineffective communication during handover jeopardizes patient safety and limits patient involvement. Our targeted, locally designed communication intervention significantly improved handover practices and patient involvement through the use of informational and interactional protocols, and redesigned handover tools and meetings. Our approach promoted a ward culture that prioritizes patient-centred care and patient safety. This innovative intervention resulted in an associated decrease in hospital-acquired complications. The intervention has been rolled out to a further five wards across two hospitals., (© 2021 The Authors. Journal of Advanced Nursing published by John Wiley & Sons Ltd.)

In this study, hydroxypropyl-beta-cyclodextrin (HP-β-CD) particles were produced using supercritical assisted atomization (SAA) with carbon dioxide as the spraying medium or co-solute and aqueous ethanol solution as the solvent. The effects of several key factors on the morphology and size of the HP-β-CD particles were investigated. These factors included the solvent effect, temperatures of the precipitator and saturator, concentration of the HP-β-CD solution, and flow rate ratio of carbon dioxide to the HP-β-CD solution. The conducive conditions for producing fine spherical particles were 54.2% ( w/w ) aqueous ethanol as the solvent; precipitator and saturator temperatures of 373.2 K and 353.2 K, respectively; a flow rate ratio of carbon dioxide to HP-β-CD solution of 1.8; and low concentrations of HP-β-CD solution. The addition of leucine (LEU) enhanced the aerosol performance of the HP-β-CD particles, and the fine particle fraction ( FPF ) of the HP-β-CD particles with the addition of 13.0 mass% LEU was 1.8 times higher than that of the HP-β-CD particles without LEU. This study shows that LEU can act as a dispersion enhancer and that HP-β-CD particles produced using SAA can be used as pulmonary drug carriers.

Competing Interests: Declaration of Competing Interest None.

Background: Chlorhexidine (CHG) bathing decreases the incidence of bloodstream infections in intensive care units, but its effect has been understudied in patients with hematological malignancies in noncritical care units., Methods: Adults with hematological malignancies hospitalized for cytotoxic chemotherapy in noncritical care units were offered daily 2% CHG bathing. We compared outcomes of patients who chose CHG bathing (CHG group) with outcomes of those who did not choose CHG bathing (usual-care group). The primary outcome was gram-positive cocci-related, skin flora-related, or central line-associated bloodstream infection. The negative control outcome was gut-origin bacteremia., Results: The CHG group (n = 485) had a crude incidence rate of the primary outcome that was 60% lower than the rate for the usual-care group (n = 408; 3.4 vs 8.4 per 1000 patient-days, P = .02) but had a similar crude incidence rate of the negative control outcome (4.5 vs 3.2 per 1000 patient-days; P = .10). In multivariable analyses, CHG bathing was associated with a 60% decrease in the primary outcome (adjusted hazard ratio [HR], 0.4; P < .001). In contrast, CHG bathing had no effect on the negative control outcome (adjusted HR, 1.1; P = .781). CHG bathing was well tolerated by participants in the CHG group., Conclusions: CHG bathing could be a highly effective approach for preventing gram-positive cocci-related, skin flora-related, or central line-associated bacteremia in patients with hematological malignancies who are hospitalized for cytotoxic chemotherapy in noncritical care units., (© The Author(s) 2019. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

The Ebola virus was first discovered in 1976, but the outbreak of Ebola virus disease that began in Guinea, West Africa, in December 2013 shocked the world. It is the largest and most severe epidemic of Ebola virus disease to date. The US Centers for Disease Control and Prevention confirmed that inadequate implementation of the policy of acquiring travel history led to a delay in identifying the first imported Ebola virus disease case. The Taiwan Centers for Disease Control developed a no-notice drill that used a simulated patient to assess hospitals' emergency preparedness capacity in responding to Ebola virus disease. Despite the fact that regular inspection shows that more than 90% of regional hospitals and medical centers inquired about patients' travel history, occupation, contact history, and cluster information, the no-notice drill revealed that more than 40% of regional hospitals and medical centers failed to ask emergency room patients about these factors. Therefore, to assist in inquiries about travel history, occupation, contact history, and cluster information in emergency triage and outpatient settings, the Taiwan CDC revised the criteria for hospital infection control inspection. It requested that hospitals issue appropriate reminders and implement process control mechanisms to block diagnostic processes in instances in which healthcare workers do not inquire about travel history, occupation, contact history, and cluster information. Furthermore, the Taiwan CDC will continue no-notice inspections in order to strengthen hospitals' infection control measures and reduce the risk of infectious disease transmission in the healthcare system.

Background: Staphylococcus aureus is a leading cause of healthcare-associated infections (HAIs), but the impact of S. aureus HAIs on the long-term survival and functional status of hospitalized patients remain unknown. This study aimed to examine whether S. aureus HAIs increase the risks for long-term mortality and disability., Methods: We conducted a retrospective population-based matched cohort study of inpatients at 8 medical centers, 43 regional hospitals, and 63 local hospitals which participated in the Taiwan Nosocomial Infection Surveillance (TNIS). We individually matched 3070 patients with S. aureus HAIs to 6140 inpatients without HAIs at a 1∶2 ratio by age, gender, hospital, specialty, underlying diseases, and the length of stay before onset of the S. aureus HAI. Main outcome measures are one-year excess risks for mortality, new-onset chronic ventilator dependence, and new-onset dialysis-dependent end-stage renal disease., Results: We found that patients with S. aureus HAIs had an excess one-year mortality of 20.2% compared with matched uninfected inpatients (P<0.001). The excess risk for new-onset chronic ventilator dependence and dialysis-dependent end-stage renal disease was 7.3% and 2.6%, respectively (Ps<0.001). S. aureus HAIs were also associated with an excess hospital stay of 12 days and an extra cost of $5978 (Ps<0.001)., Conclusion: S. aureus HAIs have substantial negative effect on the long-term outcome of hospitalized patients in terms of both mortality and disability, which should be taken into consideration in future cost-effectiveness studies of the control and prevention interventions for S. aureus HAIs.

A 31-year-old man suffered from a stab wound to the lower extremity. The patient had a hard sign of a vascular injury (a diminished distal pulse) and therefore probably should have undergone operative repair, but refused. One week later, he returned to our emergency department with a painful right thigh swelling. Bedside sonography was used to detect a pseudoaneurysm. Emergency sonography is a fast, non-invasive, and rapid decision-making approach in emergency practice.

This study demonstrated the feasibility of utilizing electrokinesis in an electrodeless dielectrophoresis chip to separate and concentrate microparticles such as biosamples. Numerical simulations and experimental observations were facilitated to investigate the phenomena of electrokinetics, i.e., electroosmosis, dielectrophoresis, and electrothermosis. Moreover, the proposed operating mode can be used to simultaneously convey microparticles through a microfluidic device by using electroosmotic flow, eliminating the need for an additional micropump. These results not only revealed that the directions of fluids could be controlled with a forward/backward electroosmotic flow but also categorized the optimum separating parameters for various microparticle sizes (0.5, 1.0 and 2.0 μm). Separation of microparticles can be achieved by tuning driving frequencies at a specific electric potential (90 Vpp·cm(-1)). Certainly, the device can be designed as a single automated device that carries out multiple functions such as transportation, separation, and detection for the realization of the envisioned Lab-on-a-Chip idea.

Discovery of an alternative fuel is now an urgent matter because of the impending issue of oil depletion. Lipids synthesized in algal cells called triacylglycerols (TAGs) are thought to be of the most value as a potential biofuel source because they can use transesterification to manufacture biodiesel. Biodiesel is deemed as a good solution to overcoming the problem of oil depletion since it is capable of providing good performance similar to that of petroleum. Expression of several genomic sequences, including glycerol-3-phosphate dehydrogenase, glycerol-3-phosphate acyltransferase, lysophosphatidic acid acyltransferase, phosphatidic acid phosphatase, diacylglycerol acyltransferase, and phospholipid:diacylglycerol acyltransferase, can be useful for manipulating metabolic pathways for biofuel production. In this study, we found this approach indeed increased the storage lipid content of C. minutissima UTEX 2219 up to 2-fold over that of wild type. Thus, we conclude this approach can be used with the biodiesel production platform of C. minutissima UTEX 2219 for high lipid production that will, in turn, enhance productivity.

Highly efficient butanol-producing bacterial microflora were isolated from hydrogen-producing sludge of a sewage treatment plant. Based on denaturing gradient gel electrophoresis (DGGE) analysis and 16s rDNA comparison, four strains from the butanol-producing microflora were identified as Clostridium saccharoperbutylacetonicum, Clostridium butylicum, Clostridium beijernckii, and Clostridium acetobutylicum. The effects of glucose, FeSO(4) · 7H(2)O and yeast extract concentrations on the butanol production by the mixture culture were investigated on batch mode. The medium composition for bio-butanol production was optimized using the Box-Behnken design and response surface methodology (RSM). The maximum butanol production rate (0.25 ± 0.02 g/L-h) and concentration (12.4 g/L) were obtained under the condition of glucose concentration, 60 g/L; FeSO(4) · 7H(2)O, 0.516 g/L; yeast extract concentration, 5.13 g/L. Addition of 6.0 g/L butyric acid significantly increased the butanol titer to 17.51 ± 0.49 g/L. Pressurized fermentation strategy (employed with a 5L fermentor) further enhanced the butanol concentration to 21.35 g/L, along with a maximum butanol rate of 1.25 g/L-h., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objective: Carbapenem-resistant Acinetobacter baumannii (CRAB) has emerged as an important pathogen causing healthcare-associated infections (HAIs) in Taiwan. The present study is aimed to investigate the epidemiology of HAIs caused by CRAB and the association of CRAB infection and hospital usage of different antimicrobials., Methods: Two nationwide databases in the period 2003 to 2008, the Taiwan Nosocomial Infection Surveillance System and National Health Insurance claim data, were used for analysis. A total of 13,811 healthcare-associated A. baumannii infections and antimicrobial usage data from 121 hospitals were analyzed., Results: There was a significant increase in the proportion of number of HAIs caused by CRAB over that by all A. baumannii (CRABpAB), from 14% in 2003 to 46% in 2008 (P<0.0001). The greatest increase was in central Taiwan, from 4% in 2003 to 62% in 2008 (P<0.0001). Use of anti-pseudomonal carbapenems, but not other classes of antibiotics, was significantly correlated with the increase of CRABpAB (r = 0.86, P<0.0001)., Conclusions: We suggested that dedicated use of anti-pseudomonal carbapenems would be an important intervention to control the increase of CRABpAB.

A novel whole-cell sensing chip system consisted of a micro-concentrator, a set of electrochemical detection electrodes, and a microfluidic channel was developed for rapid detection of arsenite in water. Firstly, the E. coli cells transformed with arsenited-regulated reporter plasmids were incubated with solution contained arsenite. Under this condition, the level of reporter protein, β-galactosidase, expressed by E. coli cells is dependent on the concentration of arsenite. Using the dielectrophoretic force, the micro-concentrator continuously enriched the E. coli cells into a small area above the embedded detection electrodes. And then the relative expression levels of β-galactosidase were obtained using the electrochemical method to measure the amount of p-aminophenol (PAP) which converted from the p-aminophenyl-β-D-galactopyranoside (PAPG) by β-galactosidase. From the result, it indicates this device can detect as low as 0.1 ppm of arsenite within 30 min. Compared with other traditional detection methods, our new device provides better performance like higher sensitivity, shorter analysis time, and lower cost in detecting the arsenite., (Copyright © 2010 Elsevier B.V. All rights reserved.)

During the period of August 2002 and November 2004, an epidemiological investigation for Bartonella infection was conducted in small mammals in Taiwan. Using whole blood culture on chocolate agar plates, Bartonella species were successfully isolated from 41.3% of the 310 animals tested. The isolation rate of Bartonella species varied among different animal species, including 52.7% of the 169 Rattus norvegicus, 28.6% of the 126 Sucus murinus, 10% of the 10 Rattus rattus and 66.7% of the three Rattus losea. Bacteremia prevalence also varied with the origin of the animals, as 56.2% of the animals captured on farms, 38.6% of the ones captured at harbour sites and 11.8% of the animals captured from urban areas were bacteremic. Through molecular analysis of the gltA gene and 16S/23S intergenic spacer region, genetic diversity of Bartonella organisms was identified, including strains closely related to Bartonella tribocorum, Bartonella grahamii, Bartonella elizabethae, Bartonella phoceensis and Bartonella rattimassiliensis. Moreover, this is the first report of zoonotic B. elizabethae and B. grahamii identified in R. losea, the lesser rice-field rat. Various Bartonella species were identified in R. norvegicus, compared to 97.2% of Suncus murinus with unique Bartonella species. By indirect immunofluorescence antibody test, using various rodent Bartonella species as antigens, consistently low percentage of seropositivity implied that small mammals may play a role as competent reservoirs of Bartonella species in Taiwan. Future studies need to be conducted to determine whether these Bartonella species would be responsible for human cases of unknown fever or febrile illness in Taiwan, especially zoonotic B. elizabethae and B. grahamii., (© 2009 Blackwell Verlag GmbH.)

A new micromachined circulating polymerase chain reaction (PCR) chip is reported in this study. A novel liquid transportation mechanism utilizing a suction-type membrane and three microvalves were used to create a new microfluidic control module to rapidly transport the DNA samples and PCR reagents around three bio-reactors operating at three different temperatures. When operating at a membrane actuation frequency of 14.29 Hz and a pressure of 5 psi, the sample flow rate in the microfluidic control module can be as high as 18 microL/s. In addition, an array-type microheater was adopted to improve the temperature uniformity in the reaction chambers. Open-type reaction chambers were designed to facilitate temperature calibration. Experimental data from infrared images showed that the percentage of area inside the reaction chamber with a thermal variation of less than 1 degrees C was over 90% for a denaturing temperature of 94 degrees C. Three array-type heaters and temperature sensors were integrated into this new circulating PCR chip to modulate three specific operating temperatures for the denaturing, annealing, and extension steps of a PCR process. With this approach, the cycle numbers and reaction times of the three separate reaction steps can be individually adjusted. To verify the performance of this circulating PCR chip, a PCR process to amplify a detection gene (150 base pairs) associated with the hepatitis C virus was performed. Experimental results showed that DNA samples with concentrations ranging from 10(5) to 10(2)copies/microL can be successfully amplified. Therefore, this new circulating PCR chip may provide a useful platform for genetic identification and molecular diagnosis.

Background and Purpose: We previously reported the development of a non-structural protein NS1 serotype-specific immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) for dengue serodiagnosis and seroepidemiological study. This assay can be used to differentiate the immunologic status of individuals into naive, primary, or secondary dengue virus (DENV) infection and identify the DENV serotypes of primary infection. A retrospective study was conducted to investigate the serological responses of confirmed dengue cases infected during each of the sequential DENV-1 (August 1994 to February 1995), DENV-2 (August to December 1997), DENV-3 (August 1998 to January 1999), and DENV-4 (June to December 2000) epidemics in Tainan City, Taiwan., Methods: 218 serum samples collected 1.1 to 7.2 years postinfection were analyzed by NS1 serotype-specific IgG ELISA together with corresponding acute and/or convalescent serum samples when available. The immunological status and the infecting DENV serotypes were determined for these individuals., Results: High titers of dengue NS1 serotype-specific IgG antibody could be detected in serum samples. Differentiation of immunological status showed that 76.6% and 23.4% of cases had primary and secondary infections, respectively. A significant age-dependent increase in the rate of secondary infection was observed for those cases born before 1942. Notably, analysis of postinfection serum samples of 17 dengue hemorrhagic fever patients infected during the 1998 DENV-3 epidemic showed that 9 cases (53%) had primary infections., Conclusions: Our data revealed that a majority of the population born after 1943 in Tainan City are naive to DENV infection and are at high risk of infection with all 4 DENV serotypes.

Rapid recovery, immobilization, and silica encapsulation of a dual-fusion enzyme was achieved by using iminodiacetic acid (IDA) modified magnetic nanoparticle as a carrier. D-amino acid oxidase (DAAO) of Rhodosporidium toruloides was used as a model enzyme in which a silica-precipitating peptide R5 and a metal ion complexing peptide (His)(6) were fused to its N- and C-terminal, respectively. After charging the magnetic particle with Cu(2+), the dual-fusion DAAO of 0.43 g could be directly recovered from the recombinant E. coli crude extract and immobilized on 1 g of the magnetic particle. Once in contact with hydrolyzed tetramethoxysilane (TMOS), the homogeneously dispersed immobilized dual-fusion DAAO was biosilicificated to form aggregates with size about 50 microm. The silica-encapsulated immobilized DAAO demonstrated a pyruvic acid production rate comparable with that of the naked immobilized DAAO in five repeated batch reactions when D-alanine was used as substrate. Furthermore, 85% of its activity remained after incubation at 60 degrees C for 1 h while the naked immobilized DAAO lost all its activity. This process provides the advantages that recombinant fusion enzyme can be directly recovered from crude extract, silica encapsulation protects the enzyme from leakage and denaturation, and the enzyme activity can be easily retrieved by applying a magnetic field.

Background: Although the previous study demonstrated the envelope protein of dengue viruses is under purifying selection pressure, little is known about the genetic differences of full-length viral genomes of DENV-3. In our study, complete genomic sequencing of DENV-3 strains collected from different geographical locations and isolation years were determined and the sequence diversity as well as selection pressure sites in the DENV genome other than within the E gene were also analyzed., Results: Using maximum likelihood and Bayesian approaches, our phylogenetic analysis revealed that the Taiwan's indigenous DENV-3 isolated from 1994 and 1998 dengue/DHF epidemics and one 1999 sporadic case were of the three different genotypes - I, II, and III, each associated with DENV-3 circulating in Indonesia, Thailand and Sri Lanka, respectively. Sequence diversity and selection pressure of different genomic regions among DENV-3 different genotypes was further examined to understand the global DENV-3 evolution. The highest nucleotide sequence diversity among the fully sequenced DENV-3 strains was found in the nonstructural protein 2A (mean +/- SD: 5.84 +/- 0.54) and envelope protein gene regions (mean +/- SD: 5.04 +/- 0.32). Further analysis found that positive selection pressure of DENV-3 may occur in the non-structural protein 1 gene region and the positive selection site was detected at position 178 of the NS1 gene., Conclusion: Our study confirmed that the envelope protein is under purifying selection pressure although it presented higher sequence diversity. The detection of positive selection pressure in the non-structural protein along genotype II indicated that DENV-3 originated from Southeast Asia needs to monitor the emergence of DENV strains with epidemic potential for better epidemic prevention and vaccine development.

We present the results of laboratory-based dengue surveillance in Taiwan for 2005. A phylogenetic study showed that multiple dengue epidemics were caused by three different imported dengue virus (DENV) strains. A strain of DENV-3 (genotype I) imported from the Philippines first appeared in the southern part of Kaohsiung City and later spread to Kaohsiung County from August to December, which resulted in 77 cases of dengue. Another strain of DENV-3 (genotype II) imported from Vietnam first appeared in the central part of Kaohsiung City and later spread to Kaohsiung County from September to December, which resulted in 35 cases of dengue. A strain of DENV-2 (American/Asian genotype) imported from Vietnam first appeared in Tainan City and later spread to Kaohsiung City/County from October to December, which resulted in 60 cases of dengue. This study provides molecular epidemiologic evidence that most dengue in Taiwan is caused by imported strains of the virus.

Microbial hyaluronic acid (HA), commonly produced by pathogenic Streptococcus, was made possible to be produced by a generally recognized as safe Lactococcus lactis by coexpressing HA synthase and uridine diphosphate-glucose dehydrogenase (UDP-GlcDH) of Streptococcus equi subsp. zooepidemicus in a nisin-controlled expression (NICE) system. With scarce expressed HA synthase alone, the constructed recombinant L. lactis (LL-NA) strain could produce HA with a concentration about 0.08 g/l in the M17 medium supplemented with 1% (w/v) glucose. In contrast to HA synthase, UDP-GlcDH of Streptococcus could be overexpressed in the NICE system. With coexpression of heterologous UDP-GlcDH with HA synthase, the constructed LL-NAB strain grew slightly slower to a concentration about 10% lower that of the LL-NA strain. However, the HA concentration produced was enhanced about eightfold to 0.65 g/l.

Vitreoscilla hemoglobin (VHb) was constitutively expressed in Acetobacter xylinum to enhance bacterial cellulose (BC) production. A pronounced enhancement of BC production in static culture was observed. Reducing O(2) tension in gaseous phase of the culture by tightly sealing the culture tube could also enhance BC production by 70%. O(2) tension in gaseous phase reduced from 21 to 15% in the sealed and static culture of VHb-expressing A. xylinum after 7 days cultivation, while 7.36g/l of BC with yield of 0.44 were obtained. BC pellicle production by VHb-expressing A. xylinum was successfully scaled-up in a sealed 4l disposable zip lock plastic bag with BC yield of 0.38 and concentration of 6.73g/l.

Bacillus subtilis strains that can produce hyaluronic acid (HA) were constructed by integrating the HA synthase gene (hasA) and the UDP-glucose dehydrogenase gene of group C Streptococcus (hasB) or of B. subtilis itself (tauD) into the amyE locus of the B. subtilis chromosome. All of the inserted genes were under the control of a strong constitutive vegII promoter of B. subtilis. Although HA production could be achieved by expressing hasA alone, coexpressing hasB or tauD with hasA could enhance HA production at least 2-fold. To replenish the energy consumed for HA biosynthesis, Vitreoscilla hemoglobin (VHb) was coexpressed with the HA-expressing genes. With the expression of VHb, not only the cell concentration was enhanced 25%, but also HA production was further increased by 100%. About 1.8 g/L of HA was obtained by the recombinant strain B. subtilis carrying VHb, hasA, and tauD genes in the expression cassette after 30 h cultivation.

Vitreoscilla hemoglobin (VHb) gene driven by the constitutive bla promoter was expressed in the cellulose-producing Acetobacter xylinum. The expressed VHb was biochemically active and could enhance cell growth in a shaken culture containing cellulase. VHb-expressing A. xylinum (VHb+) exhibited a specific growth rate 50% higher than that of the host strain (VHb-). Probably because of its faster growth rate, the size of tentacled cellulose beads produced by VHb+ was about 20% of that produced by VHb- after 2 days cultivation in a shake-flask. When cultured statically, the amount of cellulose pellicle produced by VHb+ could be 2-fold that produced by VHb-. Cellulose pellicle concentration of 11 g/L was obtained for VHb+, whereas 6 g/L was obtained for VHb- after 6 days of microaerobic incubation.

Serotyping dengue virus (DENV) from suspect human specimens is crucial for developing sound epidemiological control measurements early in the transmission season and for effective patient management. We modified DENV consensus D1 (mD1) and serotype-specific TS2 (mTS2) and redesigned serotype-specific TS1 (rTS1) and TS4 (rTS4) as described previously in the conventional capsid and premembrane gene (C-prM) protocol (R. S. Lanciotti, C. H. Calisher, D. J. Gubler, G.-J. Chang, A. V. Vorndam, J. Clin. Microbiol. 30:545-551, 1992). In addition, we designed two new sets of amplimers and probes, located at nonstructural protein 5 (NS5) and the 3' noncoding region (3'NC) of DENV. The NS5 protocol utilizes two flaviviral consensus outer amplimers (mFU1 and CFD2) and four dengue virus serotype-specific TaqMan fluorogenic probes. The 3'NC protocol uses two DENV consensus amplimers, DC10418 and CDC10564. The conventional gel-based, heminested detection method was adapted for the C-prM protocol for detecting and serotyping dengue viruses. In addition, we developed the real-time SYBR green I and postamplification melting temperature curve analysis for the mD1/TS and 3'NC protocols using identical amplification conditions. The NS5 amplimer/probe set was formulated as a one-tube, multiplex, real-time reverse transcriptase PCR for serotype identification. Three sets of amplimers and probes were verified for their specificity in tests with yellow fever, Japanese encephalitis, St. Louis encephalitis, and West Nile viruses; optimized against 109 DENV strains; and validated for detection of the virus in sera from two different panels of acute-phase human dengue serum specimens and one panel of virus isolates from dengue patients' serum specimens. Clinical evaluation by two separate laboratories indicated that the C-prM was more sensitive (100%) than the NS5 (91%) or the 3'NC (91%) protocol.

The PsADH2-promoter of Pichia stipitis alcohol dehydrogenase II (ADH II) gene was employed to control the expression of Vitreoscilla hemoglobin (VHb) gene in Pichia pastoris. As in P. stipitis, the promoter was also induced microaerobically in P. pastoris. The expression level of VHb in P. pastoris at low O2 tension (<5% air saturation) was 16 nmol/g dry cell wt, i.e. about 24-fold higher than that at 60% air saturation. The expressed VHb enhanced growth of P. pastoris under microaerobic conditions. The application of O2-regulated promoter in P. pastoris revealed that induction of high-level expression of heterologous protein is feasible without addition of supplementary compounds.

Airport fever screening in Taiwan, July 2003-June 2004, identified 40 confirmed dengue cases. Results obtained by capture immunoglobulin (Ig) M and IgG enzyme-linked immunoassay, real time 1-step polymerase chain reaction, and virus isolation showed that 33 (82.5%) of 40 patients were viremic. Airport fever screening can thus quickly identify imported dengue cases.

Expression of the gene (daao) encoding D-amino acid oxidase (DAAO) in Escherichia coli typically results in a marked decrease of cell viability, and it has generally been assumed that the consumption of intracellular D-alanine by DAAO is responsible for this effect. Vitreoscilla hemoglobin (VHb) gene (vgb) was coexpressed with Rhodosporidium toruloides D-amino acid oxidase in E. coli BL21(DE3) and BL21(DE3)pLysS, expression hosts differing in the stringency of suppressing basal transcription. Not only was the toxic effect of DAAO on cell growth relieved but also the pronounced cell lysis of BL21(DE3)pLysS caused by the expression of DAAO was prevented by coexpressing VHb with DAAO. As a result of the higher cell density achieved, DAAO activity about 1.5-fold higher than that of DAAO-expressing control strains could be obtained by DAAO/VHb-coexpressing strains. The relieving effect of VHb on DAAO toxicity resulted from its oxygen-binding ability. The low availability of free intracellular oxygen reduced DAAO activity and consequently its toxicity.

Envelope and membrane (E/M) and nonstructural protein NS1 serotype-specific capture Immunoglobulin M (IgM) enzyme-linked immunosorbent assays (ELISAs) were developed to differentiate four dengue virus serotypes. A total of 93 anti-dengue virus IgM-positive serum samples collected between days 5 and 45 of illness from 59 confirmed dengue patients were analyzed. The results showed that positive serotype specificity could be identified for 86.1 and 47.6% of serum samples tested for E/M-specific IgM antibodies versus 83.3 and 42.9% of serum samples tested for NS1-specific IgM antibodies from patients with primary and secondary dengue virus infections, respectively. Dual analyses with both E/M and NS1 serotype-specific capture IgM ELISAs showed that positive serotype specificity could be correctly identified for 98.6 and 61.9% of all of the primary and secondary serum samples tested, respectively. These findings suggested that E/M and NS1 serotype-specific capture IgM ELISAs have the potential to be of use in dengue virus serotyping.

We have found that NS1 serotype-specific immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) can be used to differentiate primary and secondary dengue virus infections. This is due to the fact that the NS1-specific IgG antibody cannot be detected before day 9 of illness for primary infection, so the NS1-specific IgG antibodies measured in acute-phase sera must come from previous infection. Comparison of NS1 serotype-specific IgG ELISA with envelope- and membrane-specific capture IgM and IgG ELISA in the differentiation of primary and secondary dengue virus infections showed good correlation (95.90% agreement). Most important, we have found that the serotype of the dengue virus from the majority of patients with primary infection could be correctly identified when convalescent-phase or postinfection sera were analyzed by NS1 serotype-specific IgG ELISA. These findings suggested that NS1 serotype-specific IgG ELISA could be reliably applied for serodiagnosis and seroepidemiological study of dengue virus infection.

A quantitative one-step SYBR Green I-based reverse transcription (RT)-PCR system was developed for the detection and differentiation of four different dengue virus serotypes in acute-phase serum samples. A set of group- and serotype-specific primer pairs was designed against conserved sequences in the core region and evaluated for clinical diagnosis. A linear relationship was obtained between the amount of input RNA and cycle threshold (Ct) value over a range of 10 to 10(7) PFU per ml of cell culture-derived dengue viruses. The detection limit of the group-specific primer pair was between 4.1 and 43.5 PFU/ml for four dengue serotypes. The detection limit of each of the serotype-specific primer pairs was calculated to be 10 PFU/ml for dengue virus serotype 1 (DEN-1), 4.6 PFU/ml for DEN-2, 4.1 PFU/ml for DEN-3, and 5 PFU/ml for DEN-4. Comparisons between the one-step SYBR Green-based RT-PCR assay and the conventional cell culture method in the clinical diagnosis of dengue virus infection from acute-phase serum samples of confirmed dengue patients were performed. The results showed that 83 and 67% of 193 acute-phase serum samples tested were positive by the one-step SYBR Green-based RT-PCR method and cell culture method, respectively. Further analysis showed that the one-step SYBR Green-based RT-PCR method could detect twice as many acute-phase serum samples with positive dengue-specific immunoglobulin M (IgM) and/or IgG antibodies than cell culture method. Our results demonstrate the potential clinical application of the one-step SYBR Green I-based RT-PCR assay for the detection and differentiation of dengue virus RNA.

An NS1 serotype-specific indirect enzyme-linked immunosorbent assay (ELISA) was developed to differentiate primary and secondary dengue virus infections and serotypes of primary dengue virus infection. For this report, we carried out retrospective seroepidemiologic studies on serum samples collected from residents of Liuchiu Hsiang, Pingtung County, an isolated island in southern Taiwan during 1997-1998. The results demonstrated that good correlation existed between dengue virus NS1 serotype-specific immunoglobulin G (IgG) ELISA and dengue virus plaque reduction neutralization test (PRNT). Our data suggested that NS1 serotype-specific IgG ELISA could replace PRNT for seroepidemiologic studies to differentiate Japanese encephalitis and dengue virus infections and for dengue virus serotyping.

Community-based seroepidemiologic studies were conducted to monitor the effectiveness of measles immunization programmes and to estimate the decay rate of vaccine-induced measles IgG titres. Sera collected from a mountain (792 sera), rural (875 sera) and urban (894 sera) populations in 1995-1997 were available. Measles IgG was quantified using a commercial EIA kit. Measles IgG seroprevalence and geometric mean titre (GMT) were calculated by setting the cut-off titre at 50 mIU/ml. The decay rate of measles IgG titres was estimated by assuming that the measles IgG titres, without exposing to wild measles virus, decay exponentially and constantly after 1 year post vaccination. The half-life of measles IgG titres was calculated from the corresponding decay rate. Measles IgG seroprevalences in these three populations have reached >95% in school children (7-18 years old) and >98% in young adults (19-25 years old) but varied from 87 to 96% in pre-school children (4-6 years old). Two-dose vaccinees, comparing with 1-dose vaccinees, had a significantly higher seroprevalence (98 versus 92%, P<0.01) and a slightly longer half-life of measles IgG titres (61 versus 27 months, P=0.08) but the measles IgG GMT in the two groups did not differ significantly (675 versus 618 mIU/ml, P=0.78).

An indirect enzyme-linked immunosorbent assay (ELISA) was developed to detect and differentiate the antibody responses to Japanese encephalitis (JE) virus nonstructural protein NS1 between infected and vaccinated individuals. The results showed that all convalescent sera from JE patients contained NS1-specific IgG antibodies, while 65 and 40% of these sera showed detectable NS1-specific IgM and IgA antibodies, respectively. Specificity analysis showed that NS1-specific IgM and IgA antibodies from JE patients do not cross-react to dengue virus NS1 glycoprotein, while IgG antibodies from 10% of JE patients showed significant cross-reaction to dengue virus NS1 glycoprotein. To differentiate infection from vaccination, the immune sera from 24 children vaccinated with inactivated JE vaccine were analyzed. The data showed that none of these immune sera had detectable NS1-specific IgG antibodies. The results demonstrated the potential application of JE NS1-specific indirect ELISA to differentiate infection from vaccination.

To understand the antibody responses to dengue (DEN) nonstructural 1 (NS1) glycoprotein and their roles in protective immunity or pathogenesis of dengue fever (DF) and dengue hemorrhagic fever (DHF), we have analyzed the NS1-speccific IgM, IgA and IgG antibodies from patients with DF and DHF. An isotype-specific, indirect enzyme-linked immunosorbent assay (ELISA) was established by coating a NS1-specific monoclonal antibody (MAb), D2/8-1, to capture soluble NS1 antigens secreted in the culture supernatants of Vero cells infected with DEN virus. We observed strong anti-NS1 antibody responses in all of the convalescent sera of patients with DF and DHF. Similar NS1-specific isotypic and serotypic antibody responses were found in the sera from DF and DHF patients. The results showed that all DEN infections induced significant NS1-specific IgG, whereas 75% and 60% of primary DF patients vs. 40% and 90% of secondary DF patients produced IgM and IgA antibodies, respectively. Specificity analysis showed that DEN NS1-specific IgG and IgA antibodies cross-react strongly to Japanese encephalitis (JE) virus NS1 glycoprotein, whereas DEN NS1-specific IgM antibodies do not cross-react to JE virus NS1 glycoprotein at all. The serotype specificity of NS1-specific IgM, IgA and IgG were found to be 80%, 67% and 75% for primary infections, and 50%, 22% and 30% for secondary infections in positive samples of DF patients. Similar pattern was found in DHF patients. The results showed that all of the DF and DHF patients produced significant NS1-specific antibodies. We did not observe direct correlation between the anti-NS1 antibody responses and DHF because sera from patients with DF and DHF showed similar anti-NS1 antibody responses., (Copyright 2000 Wiley-Liss, Inc.)

The leukocyte-endothelial adhesive interaction is one of the key mechanisms during inflammation. The human promyelocytic cell line HL60 has been used in a number of studies to characterize leukocyte-endothelial interactions, especially selectin-mediated adhesion. HL60 also has been used in studies to characterize the myeloid cell function during differentiation. In this study, we investigated the adhesive interactions of HL60 to vascular endothelium, either in its undifferentiated state or after dimethylsulfoxide-induced granulocytic differentiation. Granulocytic differentiation of HL60 cells significantly enhanced their transmigration across cytokine-activated (IL-1 beta 10 U/ml, 4 h) HUVEC monolayer. Interestingly, this enhanced transmigration of differentiated HL60 cells was inhibited by pretreatment of the monolayers with anti-E-selectin mAb as well as anti-ICAM-1 mAb or anti-VE-cadherin mAb, suggesting a potential role for E-selectin in transendothelial migration. Further study of this enhanced transmigration mechanism may elucidate the regulation of selectin-mediated leukocyte-endothelial interactions.