Microvascular complications in orthokeratology (Ortho-K): A real-time study on the microvasculature of the bulbar conjunctiva in Ortho-K treatment

Orthokeratology (Ortho-K) is an over-night hard contact lens therapy, which physically reshapes the corneal curvature in order to stabilize or temporally eliminate myopia in patients. We hypothesize that the prolonged physical contact and mechanical pressure induced by the Ortho-K lenses may create lasting inadvertent effects and damages (microangiopathy), and may bring about unwanted changes in the microvasculature of the bulbar conjunctiva. Computer-assisted intravital microscopy (CAIM) was used to view, document (via videotaping) and objectively quantify (via computer-assisted image analysis) the real-time dynamic and morphometric characteristics of the conjunctival microcirculation in long-term (at least over one year) Ortho-K patients (n = 11) and matched non-user control subjects (n = 8). Ortho-K patients were instructed to wear their lenses overnight following standard protocol. During the study, the conjunctival microcirculation of the left eye of all Ortho-K lens users was viewed, frequently re-focused and videotaped, without and with the lens in place, as outlined in Methods. The matched control subjects (non-lens wearing) were videotaped and studied in like manner. The dynamic and morphometric characteristics of each user and control subject were analyzed, quantified and summated as a severity index (SI) collectively for comparison. SI of Ortho-K lens users (4.18±1.08) differed significantly from SI of control subjects (1.75±1.39, p≤0.05). In addition, changes in the conjunctival microcirculation (e.g., flow velocity, vessel diameter, shape change, etc) were viewed and videotaped immediately after the myopic patients put on the Ortho-K lenses. Eight of the 11 Ortho-K lens users displayed significant percentage changes (p≤0.05) in flow velocity and 10 of 11 displayed significant percentage changes (p≤0.05) in vessel diameter, without and with the Ortho-K lenses. The results clearly indicated that significant microvascular changes via tissue remodeling occurred, and were caused directly by the physical presence of the Ortho-K lenses.

Bone Protective Effects of Danggui Buxue Tang Alone and in Combination With Tamoxifen or Raloxifene in vivo and in vitro

Danggui Buxue Tang (DBT), a traditional Chinese Medicine decoction containing Astragali Radix (AR) and Angelicae Sinensis Radix (ASR), is commonly prescribed for women in China as a remedy for menopausal symptoms. Previous study indicated that DBT stimulated cell growth and differentiation of human osteosarcoma MG-63 cells and exhibited estrogenic properties via estrogen receptors (ERs). The present study aimed to study the bone protective effects of DBT and its potential interactions with selective estrogen receptor modulators (SERMs, tamoxifen and raloxifene) in both in vivo and in vitro models as they act via similar ERs. Six-month-old Sprague-Dawley rats were randomly assigned to the following treatments for 12 weeks: (1) sham-operated control group with vehicle (sham), (2) ovariectomized group with vehicle (OVX), (3) OVX with 17β-estradiol (E2, 2.0 mg/kg day), (4) OVX with tamoxifen (Tamo, 1.0 mg/kg day), (5) OVX with raloxifene (Ralo, 3.0 mg/kg day), (6) OVX with DBT (DBT, 3.0 g/kg day), (7) OVX with DBT+Tamoxifen (DBT+Tamo), and (8) OVX with DBT+Raloxifene (DBT+Ralo). Effects of DBT and potential interactions between DBT and SERMs were also evaluated in MG-63 cells. DBT, tamoxifen, raloxifene, and their combinations significantly increased bone mineral density (BMD) and improved trabecular bone properties, including bone surface (BS), trabecular bone number (Tb.N), and trabecular bone separation (Tb.Sp), as well as restored changes in bone turnover biomarkers and mRNA expression of genes involved in bone metabolism in OVX rats. Furthermore, DBT, SERMs, and their combinations significantly increased serum estradiol and suppressed follicle stimulating hormone and luteinizing hormone in OVX rats, suggesting the possible involvement of the hypothalamus–pituitary–gonadal axis in mediating their bone protective effects. However, SERMs, but not DBT, significantly increased uterus index in OVX rats. DBT significantly induced ALP activity and estrogen response element-dependent transcription in MG-63 cells. Our study demonstrated that DBT alone and in combinations with SERMs could exert bone protective effects in vitro and in vivo.

The association of the dietary approach to stop hypertension (DASH) diet with blood pressure, glucose and lipid profiles in Malaysian and Philippines populations

BACKGROUND AND AIM

Despite a growing body of evidence from Western populations on the health benefits of Dietary Approaches to Stop Hypertension (DASH) diets, their applicability in South East Asian settings is not clear. We examined cross-sectional associations between DASH diet and cardio-metabolic risk factors among 1837 Malaysian and 2898 Philippines participants in a multi-national cohort.

METHODS AND RESULTS

Blood pressures, fasting lipid profile and fasting glucose were measured, and DASH score was computed based on a 22-item food frequency questionnaire. Older individuals, women, those not consuming alcohol and those undertaking regular physical activity were more likely to have higher DASH scores. In the Malaysian cohort, while total DASH score was not significantly associated with cardio-metabolic risk factors after adjusting for confounders, significant associations were observed for intake of green vegetable [0.011, standard error (SE): 0.004], and red and processed meat (-0.009, SE: 0.004) with total cholesterol. In the Philippines cohort, a 5-unit increase in total DASH score was significantly and inversely associated with systolic blood pressure (-1.41, SE: 0.40), diastolic blood pressure (-1.09, SE: 0.28), total cholesterol (-0.015, SE: 0.005), low-density lipoprotein cholesterol (-0.025, SE: 0.008), and triglyceride (-0.034, SE: 0.012) after adjusting for socio-demographic and lifestyle groups. Intake of milk and dairy products, red and processed meat, and sugared drinks were found to significantly associated with most risk factors.

CONCLUSIONS

Differential associations of DASH diet and dietary components with cardio-metabolic risk factors by country suggest the need for country-specific tailoring of dietary interventions to improve cardio-metabolic risk profiles.

The first pilot study of expanded newborn screening for inborn errors of metabolism and survey of related knowledge and opinions of health care professionals in Hong Kong

INTRODUCTION

Newborn screening is important for early diagnosis and effective treatment of inborn errors of metabolism (IEM). In response to a 2008 coroners' report of a 14-year-old boy who died of an undiagnosed IEM, the OPathPaed service model was proposed. In the present study, we investigated the feasibility of the OPathPaed model for delivering expanded newborn screening in Hong Kong. In addition, health care professionals were surveyed on their knowledge and opinions of newborn screening for IEM.

METHODS

The present prospective study involving three regional hospitals was conducted in phases, from 1 October 2012 to 31 August 2014. The 10 steps of the OPathPaed model were evaluated: parental education, consent, sampling, sample dispatch, dried blood spot preparation and testing, reporting, recall and counselling, confirmation test, treatment and monitoring, and cost-benefit analysis. A fully automated online extraction system for dried blood spot analysis was also evaluated. A questionnaire was distributed to 430 health care professionals by convenience sampling.

RESULTS

In total, 2440 neonates were recruited for newborn screening; no true-positive cases were found. Completed questionnaires were received from 210 respondents. Health care professionals supported implementation of an expanded newborn screening for IEM. In addition, there is a substantial need of more education for health care professionals. The majority of respondents supported implementing the expanded newborn screening for IEM immediately or within 3 years.

CONCLUSION

The feasibility of OPathPaed model has been confirmed. It is significant and timely that when this pilot study was completed, a government-led initiative to study the feasibility of newborn screening for IEM in the public health care system on a larger scale was announced in the Hong Kong Special Administrative Region Chief Executive Policy Address of 2015.

Neonatal outcomes of preterm or very-low-birth-weight infants over a decade from Queen Mary Hospital, Hong Kong: comparison with the Vermont Oxford Network

INTRODUCTION

There is a paucity of local data on neonatal outcomes of preterm/very-low-birth-weight infants in Hong Kong. This study aimed to evaluate the survival rate on discharge and morbidity of preterm/very-low-birth-weight infants (≤29+6 weeks and/or birth weight <1500 g) over a decade at Queen Mary Hospital in Hong Kong, so as to provide centre-specific data for prenatal counselling and to benchmark these results against the Vermont Oxford Network.

METHODS

Standardised perinatal/neonatal data were collected for infants with gestational age of 23+0 to 29+6 weeks and/or birth weight of <1500 g who were born at Queen Mary Hospital between 1 January 2005 and 31 December 2014. These data were compared with all neonatal centres in the Vermont Oxford Network in 2013. The Chi squared test was used to compare the categorical Queen Mary Hospital data with that of Vermont Oxford Network. A two-tailed P value of <0.05 was considered statistically significant.

RESULTS

The overall survival rate on discharge from Queen Mary Hospital for 449 infants was significantly higher than that of the Vermont Oxford Network (87% versus 80%; P=0.0006). The morbidity-free survival at Queen Mary Hospital (40%) was comparable with the Vermont Oxford Network (44%). At Queen Mary Hospital, 86% of infants had respiratory distress syndrome, 40% bronchopulmonary dysplasia, 44% patent ductus arteriosus, 7% severe intraventricular haemorrhage, 5% necrotising enterocolitis, 10% severe retinopathy of prematurity, 10% late-onset sepsis, and 84% growth failure on discharge. Rates of respiratory distress syndrome, intraventricular haemorrhage, necrotising enterocolitis, and severe retinopathy of prematurity were similar in the two populations. At Queen Mary Hospital, significantly more infants had bronchopulmonary dysplasia (P=0.011), patent ductus arteriosus (P=0.015), and growth failure (P=0.0001) compared with the Vermont Oxford Network. In contrast, rate of late-onset sepsis was significantly lower at Queen Mary Hospital than the Vermont Oxford Network (P=0.0002).

CONCLUSIONS

Mortality rate and most of the morbidity rates of our centre compare favourably with international standards, but rates of bronchopulmonary dysplasia and growth failure are of concern. A regular benchmarking process is crucial to audit any change in clinical outcomes after implementation of a local quality improvement project.

MUC13 protects colorectal cancer cells from death by activating the NF-κB pathway and is a potential therapeutic target

MUC13 is a transmembrane mucin glycoprotein that is over produced by many cancers, although its functions are not fully understood. Nuclear factor-κB (NF-κB) is a key transcription factor promoting cancer cell survival, but therapeutically targeting this pathway has proved difficult because NF-κB has pleiotropic functions. Here, we report that MUC13 prevents colorectal cancer cell death by promoting two distinct pathways of NF-kB activation, consequently upregulating BCL-X_L. MUC13 promoted tumor necrosis factor (TNF)-induced NF-κB activation by interacting with TNFR1 and the E3 ligase, cIAP1, to increase ubiquitination of RIPK1. MUC13 also promoted genotoxin-induced NF-κB activation by increasing phosphorylation of ATM and SUMOylation of NF-κB essential modulator. Moreover, elevated expression of cytoplasmic MUC13 and NF-κB correlated with colorectal cancer progression and metastases. Our demonstration that MUC13 enhances NF-κB signaling in response to both TNF and DNA-damaging agents provides a new molecular target for specific inhibition of NF-κB activation. As proof of principle, silencing MUC13 sensitized colorectal cancer cells to killing by cytotoxic drugs and inflammatory signals and abolished chemotherapy-induced enrichment of CD133⁺ CD44⁺ cancer stem cells, slowed xenograft growth in mice, and synergized with 5-fluourouracil to induce tumor regression. Therefore, these data indicate that combining chemotherapy and MUC13 antagonism could improve the treatment of metastatic cancers.

Apical lymph node dissection of the inferior mesenteric artery

AIM

It is controversial whether a high or low ligation of the inferior mesenteric artery (IMA) is superior. The former allows an extended lymph node clearance whereas the latter preserves the distal vascular supply via the left colic artery (LCA). Apical lymph node dissection of the IMA (ALMA) harvests nodal tissue along the IMA proximal to the LCA whilst performing a low ligation. This anatomically replicates the oncological benefit of high ligation and the vascular preservation of low ligation. Our study evaluates the nodal yield of ALMA and the short-term outcome of this technique.

METHOD

We retrospectively studied 19 patients with sigmoid or rectal cancer who underwent curative surgical resection with ALMA. All ALMAs were performed with a standard technique previously described (Kobayashi et al., Surg Endosc 2005, 20:563-9; Sekimoto et al. Surg Endosc 2010, 25:861-6) . The lymph node yield from the dissection (the ALMA specimen) was compared with the total lymph node yield. Data on the LCA anatomy, time required to perform ALMA, complications and postoperative recovery were evaluated.

RESULTS

ALMA was successful in 18 patients. Median postoperative hospitalization was 5 (2-26) days without ALMA-related morbidity or mortality. The median lymph node yield was 20 (9-41) and a median of 14.3 (0-80)% were harvested with ALMA. Two patients not having neoadjuvant chemoradiotherapy had fewer than 12 lymph nodes, excluding nodes harvested from ALMA. The average time required for ALMA was 18 min.

CONCLUSION

ALMA is a safe and feasible technique, allowing extended lymphadenectomy without sacrificing the LCA. In this small group of patients none were upstaged due to cancerous involvement of the proximal nodes.

Comparing the meanings of living with advanced breast cancer between women resilient to distress and women with persistent distress: a qualitative study

BACKGROUND

Most women with advanced breast cancer (ABC) show little distress, but about one in ten show persistent distress over time. It remains unclear if meanings ascribed by patients to ABC differentiate these distress trajectories.

STUDY AIMS

This qualitative study (a) compared illness meanings of ABC between women with persistent psychological distress and those with low/transient distress, and (b) examined how illness meanings might influence coping strategies.

METHODS

The sample was drawn from a prior quantitative study exploring psychological distress trajectories following ABC diagnosis. Overall, 42 Cantonese- or Mandarin-speaking Chinese women diagnosed with locally advanced or metastatic ABC were recruited based on their distress trajectory status (low-stable, transient, or persistent distress). Interviews were recorded, transcribed, and analyzed following grounded theory approach using simultaneous analysis.

RESULTS

Women with persistent distress viewed their diagnosis as another blow in life, the illness was global, permeating every aspect of their life. Maladaptive rumination and thought suppression were common responses to illness demands. These women had poor social support. A sense of demoralization stood out in their narratives. In contrast, women with transient/low-stable distress encapsulated the illness, with minimum impacts of their life. They did not evidence dysfunctional repetitive thoughts. Living in a supportive environment, they were able to accept and/or live in the present-moment.

CONCLUSIONS

Rumination, thought suppression, social constraints, and pre-existing exposure to life stress may be potential risks for chronic distress in response to advanced breast cancer. Persistent and transient distress responses to cancer may have different underpinnings. Copyright © 2016 John Wiley & Sons, Ltd.

Melatonin modulates M4-type ganglion-cell photoreceptors

In the retina, melatonin is secreted at night by rod/cone photoreceptors and serves as a dark-adaptive signal. Melatonin receptors have been found in many retinal neurons including melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs), suggesting it could modulate the physiology of these inner retinal photoreceptors. Here, we investigated whether melatonin modulates the alpha-like M4-type ipRGCs, which are believed to mediate image-forming vision as well as non-image-forming photoresponses. Applying melatonin during daytime (when endogenous melatonin secretion is low) caused whole-cell-recorded M4 cells' rod/cone-driven depolarizing photoresponses to become broader and larger, whereas the associated elevation in spike rate was reduced. Melanopsin-based light responses were not affected significantly. Nighttime application of the melatonin receptor antagonist luzindole also altered M4 cells' rod/cone-driven light responses but in the opposite ways: the duration and amplitude of the graded depolarization were reduced, whereas the accompanying spiking increase was enhanced. These luzindole-induced changes confirmed that M4 cells are modulated by endogenous melatonin. Melatonin could induce the above effects by acting directly on M4 cells because immunohistochemistry detected MT1 receptors in these cells, although it could also act presynaptically. Interestingly, the daytime and nighttime recordings showed significant differences in resting membrane potential, spontaneous spike rate and rod/cone-driven light responses, suggesting that M4 cells are under circadian control. This is the first report of a circadian variation in ipRGCs' resting properties and synaptic input, and of melatoninergic modulation of ipRGCs.

Cross-cultural measurement equivalence of the EQ-5D-5L items for English-speaking Asians in Singapore

PURPOSE

To investigate how the response labels of the 5-level EQ-5D (EQ-5D-5L) items are interpreted and used by English-speaking Chinese and non-Chinese Singaporeans, as a means to assessing whether those items are cross-culturally equivalent health-status measures in this Asian population.

METHODS

In face-to-face interviews, Chinese, Malay and Indian visitors to a primary care institution in Singapore were asked to rate the relative severity conveyed by EQ-5D-5L response labels, each containing the keyword of 'no(t),' 'slight(ly),' 'moderate(ly),' 'severe(ly),' or 'unable'/'extreme(ly),' using a 0-100 numerical rating scale. Participants were also asked to describe 25 hypothetical health states using the EQ-5D-5L response labels. Differences between Chinese and Malay/Indian participants in label interpretation and selection were examined using multivariate regression analysis to adjust for participant characteristics.

RESULTS

The differences in adjusted mean severity scores for individual EQ-5D-5L labels between Chinese (n = 148) and non-Chinese (Malay: n = 53; Indian: n = 56) participants ranged from 0.0 to 9.0. The relative severity of the labels to the participants supported the ordinality of the EQ-5D-5L response labels and was similar across ethnic groups. Chinese and non-Chinese participants selected similar response labels to describe each hypothetical health state, with the adjusted odds ratios of selecting any type of the five response labels for non-Chinese versus Chinese participants ranging from 0.92 to 1.15 (p > 0.05 for all).

CONCLUSIONS

The EQ-5D-5L items are likely to generate equivalent health outcomes between English-speaking Chinese and non-Chinese Singaporeans.

Emergency management of dental trauma: knowledge of Hong Kong primary and secondary school teachers

OBJECTIVES. To investigate the level of knowledge about emergency management of dental trauma among Hong Kong primary and secondary school teachers. DESIGN. Questionnaire survey. SETTING. A teachers' union that unites 90% of teachers in Hong Kong. PARTICIPANTS. Randomly selected primary and secondary school teachers. RESULTS. Only 32.8% of respondents correctly stated that a person sustaining dental trauma should go to dentists directly. In all, 73.1% of teachers correctly stated that a dental trauma patient should go for treatment immediately. Only 32.5% knew that a fractured tooth should be put in liquid. Even fewer (23.2%) realised that the displaced tooth should be repositioned back to the original position. Relatively more respondents (74.7%) understood that an avulsed baby tooth should not be put back. Disappointingly, only 16.3% of teachers knew that an avulsed permanent tooth should be replanted. Furthermore, only 29.6% of teachers thought that they were able to distinguish between deciduous teeth and permanent teeth, whilst 20.4% correctly identified at least one of the appropriate mediums: milk, physiological saline or saliva, for storing an avulsed tooth. Teachers who previously received first-aid training with dental content or acquired dental injury information from other sources, scored significantly higher than teachers without such training or acquired information. CONCLUSION. The knowledge on emergency management of dental trauma among primary and secondary school teachers in Hong Kong is insufficient, particularly on the handling of permanent tooth avulsion and the appropriate storage medium for avulsed teeth. Receipt of first-aid training with dental contents and acquisition of dental injury information from other sources were positively correlated with knowledge in managing dental trauma.

Molecular mechanisms underlying bile acid-stimulated glucagon-like peptide-1 secretion

BACKGROUND AND PURPOSE

The glucagon-like peptides GLP-1 and GLP-2 are secreted from enteroendocrine L-cells following nutrient ingestion. Drugs that increase activity of the GLP-1 axis are highly successful therapies for type 2 diabetes, and boosting L-cell secretion is a potential strategy for future diabetes treatment. The aim of the present study was to further our understanding of the bile acid receptor GPBA (TGR5), an L-cell target currently under therapeutic exploration.

EXPERIMENTAL APPROACH

GLUTag cells and mixed primary murine intestinal cultures were exposed to bile acids and a specific agonist, GPBAR-A. Secretion was measured using hormone assays and intracellular calcium and cAMP responses were monitored using real-time imaging techniques.

KEY RESULTS

Bile acid-triggered GLP-1 secretion from GLUTag cells was GPBA-dependent, as demonstrated by its abolition following tgr5 siRNA transfection. Bile acids and GPBAR-A increased GLP-1 secretion from intestinal cultures, with evidence for synergy between the effects of glucose and GPBA activation. Elevation of cAMP was observed following GPBA activation in individual GLUTag cells. Direct calcium responses to GPBAR-A were small, but in the presence of the agonist, a subpopulation of cells that was previously poorly glucose-responsive exhibited robust glucose responses. In vivo, increased delivery of bile to more distal regions of the ileum augmented L-cell stimulation.

CONCLUSIONS AND IMPLICATIONS

GPBA signalling in L-cells involves rapid elevation of cAMP, and enhanced calcium and secretory responses to glucose. Modulation of this receptor therapeutically may be an attractive strategy to enhance GLP-1 secretion and achieve better glycaemic control in diabetic patients.

Occupation and risk of non-Hodgkin's lymphoma in Singapore

BACKGROUND

Some epidemiological studies have reported that teachers may be at increased risk of non-Hodgkin's lymphoma (NHL), but results are inconsistent.

AIMS

To examine the possible association between occupation and risk of NHL in the Singapore population.

METHODS

A hospital-based interviewer-administered case-control study was carried out in five major hospitals in Singapore between April 2004 and December 2008. A complete occupational history, which included all jobs lasting over 1 year since graduation from school, was obtained for each participant. The Singapore Standard Occupational Classification was used for coding all occupations recorded.

RESULTS

Eight hundred and thirty controls and 465 NHL cases, comprising B-cell (n = 404, 87%) as well as T- and NK-cell (n = 61, 13%) neoplasms, were recruited. Having ever worked as a teacher was associated with a significantly higher risk of NHL (adjusted OR 2.04, 95% CI 1.12-3.72). Teachers who had taught for ≤10 years had a significantly higher risk of NHL (adjusted OR 2.44, 95% CI 1.11-5.34), but we did not observe an elevated risk for those who reported teaching for >10 years. Among the 31 teachers with NHL, 23% taught in upper secondary schools, with equal proportions (13%) teaching in primary and pre-primary schools, respectively. The remainder taught in other settings.

CONCLUSIONS

Teachers come into frequent contact with children and may consequently have higher rates of exposure to common infectious agents. Therefore, the hypothesis of an infective aetiology of NHL may be supported by our findings.

Annexin-1-deficient mice exhibit spontaneous airway hyperresponsiveness and exacerbated allergen-specific antibody responses in a mouse model of asthma

BACKGROUND

Glucocorticoids are the mainstream drugs used in the treatment and control of inflammatory diseases such as asthma. Annexin-1 (ANXA1) is an anti-inflammatory protein which has been described as an endogenous protein responsible for some anti-inflammatory glucocorticoid effects. Previous studies have identified its importance in other immune diseases such as rheumatoid arthritis and cystic fibrosis. ANXA1-deficient ((-/-)) mice are Th2 biased, and ANXA1 N-terminus peptide exhibits anti-inflammatory activity in a rat model of pulmonary inflammation.

OBJECTIVE

ANXA1 protein is found in bronchoalveolar lavage fluid from asthmatics. However, the function of ANXA1 in the pathological development of allergy or asthma is unclear. Thus, in this study we intended to examine the effect of ANXA1 deficiency on allergen-specific antibody responses and airway responses to methacholine (Mch).

METHODS

ANXA1(-/-) mice were sensitized with ovalbumin (OVA) and challenged with aerosolized OVA. Airway resistance, lung compliance and enhanced pause (PenH) were measured in naïve, sensitized and saline or allergen-challenged wild-type (WT) and ANXA1(-/-) mice. Total and allergen-specific antibodies were measured in the serum.

RESULTS

We show that allergen-specific and total IgE, IgG2a and IgG2b levels were significantly higher in ANXA1(-/-) mice. Furthermore, naïve ANXA1(-/-) mice displayed higher airway hypersensitivity to inhaled Mch, and significant differences were also observed in allergen-sensitized and allergen-challenged ANXA1(-/-) mice compared with WT mice.

CONCLUSIONS

In conclusion, ANXA1(-/-) mice possess multiple features characteristic to allergic asthma, such as airway hyperresponsiveness and enhanced antibody responses, suggesting that ANXA1 plays a critical regulatory role in the development of asthma.

CLINICAL RELEVANCE

We postulate that ANXA1 is an important regulatory factor in the development of allergic disease and dysregulation of its expression can lead to pathological changes which may affect disease progression.

Evolution of the haemagglutinin gene of the influenza A(H1N1)2009 virus isolated in Hong Kong, 2009–2011

Phylogenetic analysis of the haemagglutinin (HA) gene shows that the influenza A(H1N1)2009 viruses collected in Hong Kong clustered in two main branches characterised by the E391E and E391K amino acids. The main branch E391K evolved in two sub-branches with N142D and S202T mutations that first appeared in March and July 2010, respectively, with the latter becoming the predominant strain. These genetic variants that emerged display similar antigenic characteristics. Concurrent with genetic surveillance, laboratories should continue monitoring the circulating viruses antigenically.

Evolution of the haemagglutinin gene of the influenza A(H1N1)2009 virus isolated in Hong Kong, 2009-2011

Phylogenetic analysis of the haemagglutinin (HA) gene shows that the influenza A(H1N1)2009 viruses collected in Hong Kong clustered in two main branches characterised by the E391E and E391K amino acids. The main branch E391K evolved in two sub-branches with N142D and S202T mutations that first appeared in March and July 2010, respectively, with the latter becoming the predominant strain. These genetic variants that emerged display similar antigenic characteristics.Concurrent with genetic surveillance, laboratories should continue monitoring the circulating viruses antigenically.

Precise charm to strange mass ratio and light quark masses from full lattice QCD

By using a single formalism to handle charm, strange, and light valence quarks in full lattice QCD for the first time, we are able to determine ratios of quark masses to 1%. For m(c)/m(s) we obtain 11.85(16), an order of magnitude more precise than the current PDG average. Combined with 1% determinations of the charm quark mass now possible this gives m(s)(2 GeV)=92.4(1.5) MeV. The MILC result for m(s)/m(l)=27.2(3) yields m(l)(2 GeV)=3.40(7) MeV for the average of u and d quark masses.