Brief Report: Risk of Recurrent Interstitial Lung Disease From Osimertinib Versus Erlotinib Rechallenge After Symptomatic Osimertinib-Induced Interstitial Lung Disease.

Introduction: Interstitial lung disease (ILD) is the most frequent cause of drug-related mortality from EGFR tyrosine kinase inhibitors (TKIs). Yet, for patients with symptomatic osimertinib-induced ILD, the risk of recurrent ILD associated with EGFR TKI rechallenge, either with osimertinib or another TKI, such as erlotinib, is unclear. Methods: Retrospective study of 913 patients who received osimertinib treatment for EGFR mutation-positive NSCLC. Clinical characteristics, ILD treatment history, and subsequent anticancer therapy of patients with symptomatic osimertinib-induced ILD were collated. The primary end point was to compare the incidence of recurrent ILD with osimertinib versus erlotinib rechallenge. Results: Of 913 patients, 35 (3.8%) had symptomatic osimertinib-induced ILD, of which 12 (34%), 15 (43%), and eight (23%) had grade 2, 3 to 4, and 5 ILD, respectively. On ILD recovery, 17 patients had EGFR TKI rechallenge with eight received osimertinib and nine received erlotinib. The risk of recurrent ILD was higher with osimertinib rechallenge than erlotinib (p = 0.0498). Of eight, five (63%) developed recurrent ILD on osimertinib rechallenge, including three patients with fatal outcomes. In contrast, only one of nine patients (11%) treated with erlotinib had recurrent ILD. Median time to second ILD occurrence was 4.7 (range 0.7-12) weeks. Median time-to-treatment failure of patients with erlotinib rechallenge was 13.2 months (95% confidence interval: 8.6-15.0). Conclusions: The risk of recurrent ILD was considerably higher with osimertinib rechallenge than erlotinib. Osimertinib rechallenge should be avoided, whereas erlotinib may be considered in patients with symptomatic osimertinib-induced ILD.

Probing the molecular determinants of fluorinase specificity.

Molecular determinants of FlA1 fluorinase specificity were probed using 5'-chloro-5'-deoxyadenosine (5'-ClDA) analogs as substrates and FlA1 active site mutants. Modifications at F213 or A279 residues are beneficial towards these modified substrates, including 5'-chloro-5'-deoxy-2-ethynyladenosine, ClDEA (>10-fold activity improvement), and conferred novel activity towards substrates not readily accepted by wild-type FlA1.

Hospitalisation associated with the 2009 H1N1 pandemic and seasonal influenza in Hong Kong, 2005 to 2010.

Reliable estimates of the morbidity burden caused by the 2009 pandemic influenza (pH1N1) are important for assessing the severity of the pandemic. Poisson regression models were fitted to weekly numbers of cause-specific hospitalisation in Hong Kong from 2005 to 2010. Excess hospitalisation associated with the 2009 pandemic and seasonal influenza was derived from the model by incorporating the proxy variables of weekly proportions of specimens positive for the pandemic influenza A(H1N1)pdm09, seasonal influenza A (subtypes H3N2 and H1N1) and B viruses. Compared with seasonal influenza, pH1N1 influenza was associated with higher hospitalisation rates for acute respiratory disease (ARD) among children younger than 18 years and adults aged between 18 and 64 years, but among the elderly aged 65 years and older the hospitalisation rates were lower for pH1N1 than for seasonal H3N2 and H1N1 influenza. Hospitalisation rates for chronic diseases associated with pH1N1 influenza were generally higher than those associated with seasonal influenza. The reported hospitalised cases with laboratory-confirmed pandemic infections accounted for only 16% of pH1N1 influenza-associated hospitalisations for ARD in the age group 75 years and older, and 5‒66% of hospitalisations for chronic diseases in those older than 40 years. The 2009 H1N1 influenza pandemic was associated with a dramatically increased risk of hospitalisation among children and young adults. The morbidity burden of pandemic was underreported in old people and in those with chronic conditions.

The impact of clinical protocols in the management of severe sepsis: a prospective cohort study.

This study aimed to assess the availability of clinical protocols and their effect on compliance to the Surviving Sepsis Campaign bundles and on mortality in severe sepsis in ten Singaporean adult teaching intensive care units (ICU). The presence of 11 protocols in the ICUs, steps taken based on the Johns Hopkins University Quality and Safety Research Group's model to translate protocols into practice, and organisational characteristics were assessed. Clinical and research personnel recorded characteristics of patients with severe sepsis who were admitted in July 2009, the achievement of sepsis bundle targets and outcomes. Hospital mortality was 39% for 128 patients. Fewer than half of the ICUs had protocols for early goal-directed therapy, blood cultures, antibiotics, steroids, lung-protective ventilation and weaning. Compliance rates with the resuscitation and management bundles were 18 and 3% respectively. Units with protocols were generally not more likely to achieve associated bundle targets. Steps from the Johns Hopkins model to measure performance, engage teams and sustain and extend interventions were taken in fewer than half of the available protocols. However, on logistic regression analysis, the number of protocols available per ICU was independently and inversely associated with mortality. In conclusion, clinical protocols are infrequently available in Singapore's ICUs and when present do not generally improve compliance to the sepsis bundles. These protocols may, however, be a surrogate marker of the quality of care as they are independently associated with decreased mortality. The use of an integrated and multifaceted approach to translate protocols into practice should be considered.

Effect of influenza on cardiorespiratory and all-cause mortality in Hong Kong, Singapore and Guangzhou.

1. Using a common modelling approach, mortality attributable to influenza was higher in the two subtropical cities Guangzhou and Hong Kong than in the tropical city Singapore. 2. The virus activity appeared more synchronised in subtropical cities, whereas seasonality of influenza tended to be less marked in the tropical city. 3. High temperature was associated with increased mortality after influenza infection in Hong Kong, whereas relative humidity was an effect modifier for influenza in Guangzhou. No effect modification was found for Singapore. 4. Seasonal and environmental factors probably play a more important role than socioeconomic factors in regulating seasonality and disease burden of influenza. Further studies are needed in identifying the mechanism behind the regulatory role of environmental factors.

Enterovirus 71 encephalomyelitis and Japanese encephalitis can be distinguished by topographic distribution of inflammation and specific intraneuronal detection of viral antigen and RNA.

AIMS: To investigate if two important epidemic viral encephalitis in children, Enterovirus 71 (EV71) encephalomyelitis and Japanese encephalitis (JE) whose clinical and pathological features may be nonspecific and overlapping, could be distinguished. METHODS: Tissue sections from the central nervous system of infected cases were examined by light microscopy, immunohistochemistry and in situ hybridization. RESULTS: All 13 cases of EV71 encephalomyelitis collected from Asia and France invariably showed stereotyped distribution of inflammation in the spinal cord, brainstem, hypothalamus, cerebellar dentate nucleus and, to a lesser extent, cerebral cortex and meninges. Anterior pons, corpus striatum, thalamus, temporal lobe, hippocampus and cerebellar cortex were always uninflamed. In contrast, the eight JE cases studied showed inflammation involving most neuronal areas of the central nervous system, including the areas that were uninflamed in EV71 encephalomyelitis. Lesions in both infections were nonspecific, consisting of perivascular and parenchymal infiltration by inflammatory cells, oedematous/necrolytic areas, microglial nodules and neuronophagia. Viral inclusions were absent. CONCLUSIONS: Immunohistochemistry and in situ hybridization assays were useful to identify the causative virus, localizing viral antigens and RNA, respectively, almost exclusively to neurones. The stereotyped distribution of inflammatory lesions in EV71 encephalomyelitis appears to be very useful to help distinguish it from JE.

Excess mortality associated with the 2009 pandemic of influenza A(H1N1) in Hong Kong.

Reliable estimates of the burden of 2009 pandemic influenza A(pH1N1) cannot be easily obtained because only a small fraction of infections were confirmed by laboratory tests in a timely manner. In this study we developed a Poisson prediction modelling approach to estimate the excess mortality associated with pH1N1 in 2009 and seasonal influenza in 1998-2008 in the subtropical city Hong Kong. The results suggested that there were 127 all-cause excess deaths associated with pH1N1, including 115 with cardiovascular and respiratory disease, and 22 with pneumonia and influenza. The excess mortality rates associated with pH1N1 were highest in the population aged ≥65 years. The mortality burden of influenza during the whole of 2009 was comparable to those in the preceding ten inter-pandemic years. The estimates of excess deaths were more than twofold higher than the reported fatal cases with laboratory-confirmed pH1N1 infection.

Novel multiplex oligonucleotide-conjugated bead suspension array for rapid identification of enterovirus 71 subgenogroups.

A high-throughput multiplex bead suspension array was developed for the rapid subgenogrouping of EV71 strains, based on single nucleotide polymorphisms observed within the VP1 region with a high sensitivity as low as 1 PFU. Of 33 viral isolates and 55 clinical samples, all EV71 strains were successfully detected and correctly subgenogrouped.

Comparison of the technical and clinical performance of the Elecsys HBsAg II assay with the Architect, AxSym, and Advia Centaur HBsAg screening assays.

South East Asia has some of the highest prevalence rates of hepatitis B virus (HBV) infection (>or=8%) in the world, and the emergence of hepatitis B surface antigen (HBsAg) mutant strains is a growing problem. Assays with the highest levels of sensitivity, including mutant detection, should be used for routine HBsAg screening. In this large multicenter study, the clinical and technical performance of the fully automated Elecsys HBsAg II assay was compared with the Architect, AxSYM, and Advia Centaur HBsAg assays for HBsAg screening. Nine laboratories (three each from Thailand, Korea, and Singapore) compared the Elecsys HBsAg II assay with their routine HBsAg screening assay against a range of stored and routine clinical samples, including recombinant mutants. The Elecsys HBsAg II assay demonstrated equivalent sensitivity and specificity to the Architect HBsAg assay. However, the Elecsys HBsAg II assay recognized a native mutant sample (L94S, L97V, L98V, T123A) that the Architect HBsAg assay failed to detect. The AxSYM and Advia Centaur HBsAg assays appeared less sensitive for the detection of early HBV infection and also failed to detect some of the recombinant mutant strains. There was almost complete agreement between the Elecsys HBsAg II assay and comparator assays with respect to routine serum samples. The results of this study demonstrate that the Elecsys HBsAg II assay is a highly sensitive and specific screening assay for HBsAg and detects reliably the most important and clinically relevant HBV mutants and genotypes. It is suitable for routine HBsAg screening in Asia.

Use of the cytomegalovirus pp65 antigenemia assay for preemptive therapy in allogeneic hematopoietic stem cell transplantation: a real-world review.

Despite advances in surveillance strategies and antivirals, cytomegalovirus (CMV) infection continues to pose problems to patients receiving hematopoietic stem cell transplants (HSCTs). The bone marrow transplant (BMT) unit at the Singapore General Hospital embraced the preemptive strategy in late 2003. Although several studies have demonstrated its usefulness, we conducted this review to document CMV-related events at our institution. Forty-six patients underwent CMV surveillance using the CMV pp65 antigenemia (CMV Ag) assay from January 2004 to December 2005. Twenty-seven patients had CMV infection, and 19 remained antigenemia-negative. No differences were found between the 2 groups for the following potential risk factors for CMV infection: age, total number of co-morbidities, duration of neutropenia after conditioning, baseline creatinine, type of conditioning regimen (conventional vs. reduced intensity), type of transplant (matched sibling vs. others), recipient CMV status, donor CMV status, and use of total body irradiation. Two patients received alemtuzumab; both developed CMV Ag. Twelve episodes of CMV infection occurred after the 100th post-HSCT day. Two patients developed CMV disease. One of them could be considered a failure of the preemptive strategy, as she had CMV gastritis diagnosed on the same day that she became pp65-positive. The other developed CMV disease despite prompt institution of ganciclovir, although she had multiple post-HSCT complications requiring enhanced immunosuppression, as well as relapsed disease. One-year disease-free survival was 55.5% in those with CMV infection and 52.3% in those without infection. Survival was not affected by CMV infection.

Theory of enhanced performance emerging in a sparsely connected competitive population.

We provide an analytic theory to explain Anghel et al's recent numerical finding whereby a maximum in the global performance emerges for a sparsely connected competitive population [Phys. Rev. Lett. 92, 058701 (2004)]. We show that the effect originates in the highly correlated dynamics of strategy choice, and can be significantly enhanced using a simple modification to the model.

Effects of trypan blue on cell viability and gene expression in human retinal pigment epithelial cells.

AIM: To evaluate the effects of trypan blue on cell viability and gene expression in human retinal pigment epithelial (RPE) cells. METHODS: Three concentrations (0.06 mg/ml, 0.6 mg/ml, and 4 mg/ml) of trypan blue were applied to human ARPE19 cells for 1 minute. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RPE cells were sampled daily for 6 consecutive days to assess the effects of trypan blue on cell viability. The effects of trypan blue on the expression of apoptosis related and cell cycle arrest gene expressions including c-fos, c-jun, p53, and p21 were performed using reverse transcription-polymerase chain reaction and immunostaining. RESULTS: The MTT assay showed a concentration dependent suppression effect of trypan blue on cell viability, with higher reduction in the 0.6 mg/ml and 4 mg/ml trypan blue treated groups. No significant change in the expression of c-fos and c-jun was found with all three concentrations of trypan blue. An increase in p53 expression was found in the 4 mg/ml trypan blue treated group at 10-30 minutes after trypan blue application. Immunostaining showed a mild, albeit insignificant, increase of p53 expression in the RPE cells. No significant increase in p21 expression was observed in the 0.06 mg/ml trypan blue treated group but there were significant increases in p21 expression in both the 0.6 mg/ml (p = 0.032) and the 4 mg/ml (p = 0.025) treated groups. CONCLUSIONS: Trypan blue may lead to toxicity on cultured RPE cells as indicated by the reduction in cell viability and changes in the expression of apoptosis related and cell cycle arrest genes at higher concentrations. The application of 0.06 mg/ml trypan blue for 1 minute appeared to have no significant effect on cultured RPE.

Hand, foot and mouth disease in Singapore: a comparison of fatal and non-fatal cases.

AIM: An epidemic of hand, foot and mouth disease (HFMD) occurred in Singapore between September and November 2000. During the epidemic, there were four HFMD-related deaths and after the epidemic, another three HFMD-related deaths. This study sought to determine the risk factors predictive of death from HFMD disease. METHODS: The risk factors for fatal HFMD were determined by comparing clinical and laboratory findings between fatal cases (n = 7) and non-fatal controls (n = 131) admitted between September 2000 and April 2001. Enterovirus 71 positive fatal cases (n = 4) and non-fatal controls (n = 63) were also compared. RESULTS: In total, 138 HFMD cases with a mean age of 32 mo were studied. The majority of fatal cases died from interstitial pneumonitis, of whom three also had brainstem encephalitis. Of the 131 non-fatal cases, 3 had concomitant infections (respiratory syncytial virus bronchiolitis, right-sided pneumonia, Haemophilus influenzae type b meningitis), 2 had aseptic meningitis, and 1 each had transient drowsiness, intravenous immunoglobulin-related complications and transverse myelitis. By multivariate logistic regression analysis, atypical physical findings (p = 0.0006), raised total white cell count (p = 0.0128), vomiting (p = 0.0116) and absence of mouth ulcers (p = 0.043) were predictive of a fatal course. Although previous epidemics have described neurogenic pulmonary oedema as the main cause of death, the fatal cases in this study died mainly from interstitial pneumonitis alone or with myocarditis or encephalitis. CONCLUSION: Although HFMD is generally a benign disease, risk factors such as vomiting, absence of mouth ulcers, atypical presentation and raised total white cell count should alert the physician of a fatal course of illness.

Clinical characteristics of an outbreak of hand, foot and mouth disease in Singapore.

BACKGROUND: We experienced a hand, foot and mouth disease (HFMD) outbreak in late year 2000 in Singapore. Between 14 September 2000 and 14 November 2000, a total of 3526 cases of HFMD were notified. There were 652 patients clinically suspected to have HFMD, who were seen at the Children's Emergency department of KK Women's and Children's Hospital of Singapore. OBJECTIVE OF THE STUDY: To study the clinical profile and virologic isolates of children admitted with HFMD during the outbreak. STUDY DESIGN: A prospective observational study. METHODS: Analysis of clinical features and virologic studies of 129 selected cases of HFMD and herpangina. RESULTS: The median age was 25 months with a range of between 4 months and 11 years. The majority were less than 5 years old (87%). The male-to-female ratio was 1.3:1. The median numbers of day of illness to presentation to the hospital was 3 days. Poor feeding and loss of appetite accounted for 76.7% of the admissions. Symptoms of vomiting were present in 37.2% of the cases. Oral ulcers were found in 96.1%, rashes over hands in 87.6%, over feet in 86.8% and over buttocks in 54.3%. Only 4.7% exhibited no rashes other than oral ulcers and were labelled as herpangina. The median duration of fever was 3 days, ranging from 2 to 7 days. An intravenous drip was required in 68.2% due to poor feeding. Viral cultures were sent in 89.1% of patients of whom 61.7% of patients were positive for viruses. Of the positive cultures, types of viruses isolated were EV71 (enterovirus 71) in 59/71 (83%), Coxsackievirus (A16, A24, A2 B3, B4) in 6/71 (8.4%), EV Untypable in 4/71 (5.6%) and mixed [EV71, echo25, cytomegalovirus (CMV)] in 2/71 (2.8%). EV71 was isolated mostly from stool samples followed by vesicle fluid culture and throat swabs. Two siblings aged 14 months and 2.5 years died during this period at day 5 of illness, their post-mortem examinations showed interstitial pneumonitis of the lungs. EV71 was isolated from the brain, heart, tonsils, intestines, throat and rectal swabs. A raised total white cell count of 14,000/L versus 12,000/L was significantly associated with complicated HFMD (P = 0.04). There was no difference in clinical characteristics of EV71 versus non-EV71 infections. Other viral illnesses, e.g. measles and CMV, may be mistaken for HFMD in the outbreak setting. CONCLUSIONS: HFMD tends to occur in younger children less than 5 years old due to low herd immunity. Poor feeding due to mouth ulcers accounts for admission to hospital requiring intravenous drip. EV71 accounted for the majority (75%) of the positive isolations, followed by coxsackievirus and untypable EV, mixed infection of echovirus or CMV. The yield of virus isolation was highest from stool, followed by vesicles and throat swabs. There is no difference in clinical characteristics of EV71 and non-EV71 virus infections. Enterovirus can cause mild symptoms to fatal death. Two infants died of interstitial pneumonitis and encephalitis.

Full-field optical coherence tomography by two-dimensional heterodyne detection with a pair of CCD cameras.

A two-dimensional heterodyne detection technique based on the frequency-synchronous detection method [Jpn. J. Appl. Phys. 39, 1194 (2000)] is demonstrated for full-field optical coherence tomography. This technique, which employs a pair of CCD cameras to detect the in-phase and quadrature components of the heterodyne signal simultaneously, offers the advantage of phase-drift suppression in interferometric measurement. Horizontal cross-sectional images are acquired at the rate of 100 frames/s in a single longitudinal scan, with a depth interval of 6 microm, making the rapid reconstruction of three-dimensional images possible.

Hemagglutinin-neuraminidase sequence and phylogenetic analyses of mumps virus isolates from a vaccinated population in Singapore.

During 1999-2000, a sustained mumps outbreak in the highly vaccinated population in Singapore was attributed to vaccine failure associated with the Rubini vaccine strain. To explain this phenomenon, the complete nucleotide and amino acid sequences of the hemagglutinin-neuraminidase (HN) gene of eight mumps virus isolates from patients with parotitis in Singapore were determined and compared with those of known vaccine strains. Phylogenetic trees constructed on the basis of HN nucleotide and amino acid sequences showed that the Singapore mumps virus isolates were more closely related to the Urabe strain and belonged to a different cluster from the Rubini and Jeryl-Lynn strains. The Rubini vaccine showed only approximately 93% nucleotide and approximately 96% amino acid sequence similarity to Urabe and Singapore isolates. Compared with the vaccine strains, six of the eight isolates lacked the extracellular glycosylation site at residues 400-402. Other significant amino acid disparities (e.g., at residue 354) may also affect the antigenic properties of the HN protein. These findings suggest that the evolution and adaptation of the currently circulating mumps virus strains in the community has led to the emergence of genetically distinct viral strains. The low vaccine efficacy of the Rubini strain represents a major reason for the recent mumps resurgence and failure of mumps immunization in Singapore.