Time to Rt < 1 for COVID-19 public health lockdown measures.

The epidemiological target of lockdowns is to drive down the effective reproduction number (Rt) to less than 1. A key unknown is the duration that lockdowns need to be in place to achieve this and which lockdown measures are effective. Daily number of laboratory confirmed community coronavirus 2019 cases were extracted from regular reports from the Ministry of Health Singapore from 20 March 2020 to 4 May 2020. We generated daily Rt to estimate the time needed for these public health lockdown measures to control the spread of severe acute respiratory syndrome coronavirus 2 as demonstrated by Rt < 1. It took about 14 days of nationwide lockdown for the Rt trend to change and start falling. The upper limit of the 95% confidence interval for time to Rt < 1 was day 15 of lockdown. We have shown that it is possible to start 'bending the Rt curve' about 2 weeks after implementation of specific lockdown measures with strict compliance.

Dietary Fibre for the Prevention of Cardiovascular Disease.

Cardiovascular disease (CVD) remains the major cause of mortality worldwide. The importance of diet in optimising cardiovascular health has been illustrated in various studies. The role of dietary fibre in CVD prevention remains debatable. Dietary fibre helps to reduce total cardiovascular risk by engendering better cholesterol level and blood pressure, for example. The observed benefits, particularly for CVD mortality, seem to correlate with the level of dietary fibre intake in a dose-response fashion. Total aversion to foods with carbohydrates could potentially restrict the sources of dietary fibre that are available, particularly whole grain products which are recommended in the Mediterranean diet and the Eat-Lancet report on healthy diets. Further high-quality nutrition research is required to discern the absolute benefits of dietary fibre for CVD prevention. This may have implications for total healthcare expenditure, by means of public health and prevention policy that would serve to reduce the global burden of CVD.

Planning and coordination of the radiological response to the coronavirus disease 2019 (COVID-19) pandemic: the Singapore experience.

Coronavirus disease 2019 (COVID-19) has spread fast and extensively around the world, with significant mortality and morbidity. As this is a respiratory infection, chest radiography and computed tomography (CT) are important imaging techniques in the work-up of this disease. Given its highly infectious nature, cross-infection within the healthcare setting and radiology departments needs to be addressed actively and prevented. We describe the response of radiology departments in Singapore to this pandemic, in terms of diagnosis, re-configuration of the department, re-organisation and segregation of staff, infection control, managerial, and leadership issues.

BOS is associated with decreased HDAC2 from steroid resistant lymphocytes in the small airways.

Immunosuppression therapies including corticosteroids fail to prevent bronchiolitis obliterans syndrome (BOS), primarily a disease of the small airways, following lung transplantation. We reported increases in steroid-resistant proinflammatory lymphocytes and their loss of histone deacetylase 2 (HDAC2), an important mediator of steroid action, in the blood of stable lung transplant recipients. We noted similar increases in the steroid-resistant lymphocytes in both the blood and small airways in BOS compared with the large airways. We hypothesized that these small airway cells would also exhibit a loss of HDAC2, and that these changes could be reversed by treatment with theophylline (HDAC2 activator). Blood, bronchoalveolar lavage and large and small airway brushings were collected from lung transplant patients with BOS (n = 12) or stable lung function (n = 18) and healthy aged-matched controls (n = 13). Intracellular proinflammatory cytokines [interferon (IFN-γ) and tumour necrosis factor (TNF)-α and HDAC2 were measured in CD8+ T, natural killer (NK) T-like and NK cells from cultured small airway brushings ± 5 mg/l theophylline ± 1 µM prednisolone using flow cytometry. Increased small airway CD8 T, NK T-like and NK cells were identified in BOS versus stable transplant and controls. In BOS, these cells exhibited increased IFN-γ/TNF-α and a loss of HDAC2. HDAC2 expression by small airway CD8+ T cells correlated with forced expiratory volume in 1 s (FEV1 ) (R = 0·880, P = 0·031). Theophylline and prednisolone synergistically up-regulated HDAC2 in CD8+ T cells. BOS is associated with loss of HDAC2 from steroid-resistant proinflammatory CD8+ T, NK T-like and NK cells in the small airways. Therapeutically increasing HDAC2 in these lymphocytes may reduce steroid resistance and improve graft survival.

Clinical risk factors for invasive aspergillosis in lung transplant recipients: Results of an international cohort study.

BACKGROUND: Invasive aspergillosis (IA) is a frequent complication in lung transplant recipients (LTRs). Clinical risk factors for IA have not been fully characterized, especially in the era of extensive anti-fungal prophylaxis. The primary objective of this study was to evaluate the clinical risk factors associated with IA in LTRs. The secondary objective was to assess the mortality in LTRs who had at least 1 episode of IA compared with LTRs who never had experienced IA. METHODS: We conducted an international, multicenter, retrospective cohort study of 900 consecutive adults who received lung transplants between 2005 and 2008 with 4years of follow-up. Risk factors associated with IA were identified using univariate and multiple regression Cox proportional hazards models. RESULTS: Anti-fungal prophylaxis was administered to 61.7% (555 of 900) of patients, and 79 patients developed 115 episodes of IA. The rate to development of the first episode was 29.6 per 1,000 person-years. Aspergillus fumigatus was the most common species isolated (63% [72 of 115 episodes]). Through multivariate analysis, significant risk factors identified for IA development were single lung transplant (hazard ratio, 1.84; 95% confidence interval, 1.09-3.10; p = 0.02,) and colonization with Aspergillus at 1 year post-transplantation (hazard ratio, 2.11; 95% confidence interval, 1.28-3.49; p = 0.003,). Cystic fibrosis, pre-transplant colonization with Aspergillus spp, and use of anti-fungal prophylaxis were not significantly associated with the development of IA. Time-dependent analysis showed IA was associated with higher mortality rates. CONCLUSION: Incidence of IA remains high in LTRs. Single-lung transplant and airway colonization with Aspergillus spp. within 1 year post-transplant were significantly associated with IA.

GENIPAC: A Genomic Information Portal for Head and Neck Cancer Cell Systems.

Head and neck cancer (HNC)-derived cell lines represent fundamental models for studying the biological mechanisms underlying cancer development and precision therapies. However, mining the genomic information of HNC cells from available databases requires knowledge on bioinformatics and computational skill sets. Here, we developed a user-friendly web resource for exploring, visualizing, and analyzing genomics information of commonly used HNC cell lines. We populated the current version of GENIPAC with 44 HNC cell lines from 3 studies: ORL Series, OPC-22, and H Series. Specifically, the mRNA expressions for all the 3 studies were derived with RNA-seq. The copy number alterations analysis of ORL Series was performed on the Genome Wide Human Cytoscan HD array, while copy number alterations for OPC-22 were derived from whole exome sequencing. Mutations from ORL Series and H Series were derived from RNA-seq information, while OPC-22 was based on whole exome sequencing. All genomic information was preprocessed with customized scripts and underwent data validation and correction through data set validator tools provided by cBioPortal. The clinical and genomic information of 44 HNC cell lines are easily assessable in GENIPAC. The functional utility of GENIPAC was demonstrated with some of the genomic alterations that are commonly reported in HNC, such as TP53, EGFR, CCND1, and PIK3CA. We showed that these genomic alterations as reported in The Cancer Genome Atlas database were recapitulated in the HNC cell lines in GENIPAC. Importantly, genomic alterations within pathways could be simultaneously visualized. We developed GENIPAC to create access to genomic information on HNC cell lines. This cancer omics initiative will help the research community to accelerate better understanding of HNC and the development of new precision therapeutic options for HNC treatment. GENIPAC is freely available at http://genipac.cancerresearch.my/ .

Bronchiolitis obliterans syndrome is associated with increased p-glycoprotein expression and loss of glucocorticoid receptor from steroid-resistant proinflammatory CD8+ T cells.

Immunosuppressive therapy fails to suppress the production of proinflammatory cytokines, particularly by CD8+ T cells, in stable lung transplant recipients and those undergoing chronic rejection, suggesting that some patients may become relatively resistant to immunosuppressants such as glucocorticoids (GC). We have shown loss of GC receptor (GCR) from the CD8+ cells, and we hypothesized that the drug membrane efflux pump, p-glycoprotein-1 (Pgp), may also be involved in lymphocyte steroid resistance following lung transplant. Pgp/GCR expression and interferon (IFN)-γ/tumour necrosis factor (TNF)-α proinflammatory cytokine production was measured in blood lymphocytes from 15 stable lung transplant patients, 10 patients with bronchiolitis obliterans syndrome (BOS) and 10 healthy aged-matched controls (± prednisolone ± Pgp inhibitor, cyclosporin A ± GCR activator, Compound A) using flow cytometry. Both Pgp+ and Pgp- lymphocyte subsets from all subjects produced IFN-γ/TNF-α proinflammatory cytokines. Pgp expression was increased in CD8+ Pgp+ T cells and correlated with IFN-γ/TNF-α expression and BOS grade. Reduced GCR was observed in CD8+ Pgp- T, natural killer (NK) T-like and NK cells from stable patients compared with controls, and reduced further in CD8+ Pgp- T cells in BOS. The addition of 2·5 ng/ml cyclosporin A and 1 µM prednisolone inhibit IFN-γ/TNF-α production significantly by CD8+ Pgp+ T cells from BOS patients. The addition of 10 µM Compound A and 1 µM prednisolone inhibit IFN-γ/TNF-α production significantly by CD8+ Pgp- T cells from BOS patients. BOS is associated with increased Pgp expression and loss of GCR from steroid-resistant proinflammatory CD8+ T cells. Treatments that inhibit Pgp and up-regulate GCR in CD8+ T cells may improve graft survival.

Voriconazole and squamous cell carcinoma after lung transplantation: A multicenter study.

This study evaluated the independent contribution of voriconazole to the development of squamous cell carcinoma (SCC) in lung transplant recipients, by attempting to account for important confounding factors, particularly immunosuppression. This international, multicenter, retrospective, cohort study included adult patients who underwent lung transplantation during 2005-2008. Cox regression analysis was used to assess the effects of voriconazole and other azoles, analyzed as time-dependent variables, on the risk of developing biopsy-confirmed SCC. Nine hundred lung transplant recipients were included. Median follow-up time from transplantation to end of follow-up was 3.51 years. In a Cox regression model, exposure to voriconazole alone (adjusted hazard ratio 2.39, 95% confidence interval 1.31-4.37) and exposure to voriconazole and other azole(s) (adjusted hazard ratio 3.45, 95% confidence interval 1.07-11.06) were associated with SCC compared with those unexposed after controlling for important confounders including immunosuppressants. Exposure to voriconazole was associated with increased risk of SCC of the skin in lung transplant recipients. Residual confounding could not be ruled out because of the use of proxy variables to control for some confounders. Benefits of voriconazole use when prescribed to lung transplant recipients should be carefully weighed versus the potential risk of SCC. EU PAS registration number: EUPAS5269.

Solution structure analysis of the periplasmic region of bacterial flagellar motor stators by small angle X-ray scattering.

The bacterial flagellar motor drives the rotation of helical flagellar filaments to propel bacteria through viscous media. It consists of a dynamic population of mechanosensitive stators that are embedded in the inner membrane and activate in response to external load. This entails assembly around the rotor, anchoring to the peptidoglycan layer to counteract torque from the rotor and opening of a cation channel to facilitate an influx of cations, which is converted into mechanical rotation. Stator complexes are comprised of four copies of an integral membrane A subunit and two copies of a B subunit. Each B subunit includes a C-terminal OmpA-like peptidoglycan-binding (PGB) domain. This is thought to be linked to a single N-terminal transmembrane helix by a long unstructured peptide, which allows the PGB domain to bind to the peptidoglycan layer during stator anchoring. The high-resolution crystal structures of flagellar motor PGB domains from Salmonella enterica (MotBC2) and Vibrio alginolyticus (PomBC5) have previously been elucidated. Here, we use small-angle X-ray scattering (SAXS). We show that unlike MotBC2, the dimeric conformation of the PomBC5 in solution differs to its crystal structure, and explore the functional relevance by characterising gain-of-function mutants as well as wild-type constructs of various lengths. These provide new insight into the conformational diversity of flagellar motor PGB domains and experimental verification of their overall topology.

TRPV4 plays a role in breast cancer cell migration via Ca2+-dependent activation of AKT and downregulation of E-cadherin cell cortex protein.

TRPV4 belongs to the 'Transient Receptor Potential' (TRP) superfamily. It has been identified to profoundly affect a variety of physiological processes, including nociception, heat sensation and inflammation. Unlike other TRP superfamily channels, its role in cancers are unknown until recently when we reported TRPV4 to be required for cancer cell softness that may promote breast cancer cell extravasation and metastasis. Here, we elucidated the molecular mechanisms mediated by TRPV4 in the metastatic breast cancer cells. TRPV4-mediated signaling was demonstrated to involve Ca2+-dependent activation of AKT and downregulation of E-cadherin expression, which was abolished upon TRPV4 silencing. Functionally, TRPV4-enhanced breast caner cell transendothelial migration requires AKT activity while a combination of transcriptional and post-translational regulation contributed to the TRPV4-mediated E-cadherin downregulation. Finally, mass spectrometry analysis revealed that TRPV4 is required for the expression of a network of secreted proteins involved in extracellular matrix remodeling. In conclusion, TRPV4 may regulate breast cancer metastasis by regulating cell softness through the Ca2+-dependent AKT-E-cadherin signaling axis and regulation of the expression of extracellular proteins.

Cochlear duct length-one size fits all?

OBJECTIVE: Recent studies demonstrated the utility of high-resolution computed tomography (HRCT) scans in measuring basal cochlear length and cochlear insertion depths. These studies showed significant variations in the anatomy of the cochlea amongst humans. The aim of our study was to investigate for gender and racial variations in the basal turn length of the human cochlea in an Asian population. METHOD: HRCT temporal bone data from year 1997 till 2012 of patients with normally developed cochleae who reported with otologic disease was obtained. Reconstruction of the full basal turn was performed for both ears. The largest distance from the midpoint of the round window, through the midmodiolar axis, to the lateral wall was measured (distance A). Length of the lateral wall of the cochlea to the first turn (360°) was calculated and statistically analyzed. RESULTS: HRCT temporal bone data from 161 patients was initially obtained. Four patients were subsequently excluded from the study as they were of various other racial groups. Study group therefore comprised of 157 patients (314 cochleae). Mean distance A was statistically different between the two sides of the ear (right 9.09mm; left 9.06mm; p=0.0069). Significant gender and racial differences were also found. Mean distance A was 9.17mm in males and 8.97mm in females (p=0.0016). The racial groups were Chinese (39%), Malay (38%) and Indian (22%). Between racial groups, mean distance A was 9.11mm (Chinese), 9.11mm (Malays) and 8.99mm (Indians). The mean basal turn lengths ranged from 19.71mm to 25.09mm. With gender factored in, significant variation in mean basal turn lengths was found across all three racial groups (p=0.04). CONCLUSION: The view of the basal turn of the cochlea from HRCT is simple to obtain and reproducible. This study found significant differences in basal cochlear length amongst male and female Asian patients, as well as amongst various racial groups. This has implications for cochlear electrode insertion as well as electrode array design.

Alterations in leukocyte transcriptional control pathway activity associated with major depressive disorder and antidepressant treatment.

Major depressive disorder (MDD) is associated with a significantly elevated risk of developing serious medical illnesses such as cardiovascular disease, immune impairments, infection, dementia and premature death. Previous work has demonstrated immune dysregulation in subjects with MDD. Using genome-wide transcriptional profiling and promoter-based bioinformatic strategies, we assessed leukocyte transcription factor (TF) activity in leukocytes from 20 unmedicated MDD subjects versus 20 age-, sex- and ethnicity-matched healthy controls, before initiation of antidepressant therapy, and in 17 of the MDD subjects after 8 weeks of sertraline treatment. In leukocytes from unmedicated MDD subjects, bioinformatic analysis of transcription control pathway activity indicated an increased transcriptional activity of cAMP response element-binding/activating TF (CREB/ATF) and increased activity of TFs associated with cellular responses to oxidative stress (nuclear factor erythroid-derived 2-like 2, NFE2l2 or NRF2). Eight weeks of antidepressant therapy was associated with significant reductions in Hamilton Depression Rating Scale scores and reduced activity of NRF2, but not in CREB/ATF activity. Several other transcriptional regulation pathways, including the glucocorticoid receptor (GR), nuclear factor kappa-B cells (NF-κB), early growth response proteins 1-4 (EGR1-4) and interferon-responsive TFs, showed either no significant differences as a function of disease or treatment, or activities that were opposite to those previously hypothesized to be involved in the etiology of MDD or effective treatment. Our results suggest that CREB/ATF and NRF2 signaling may contribute to MDD by activating immune cell transcriptome dynamics that ultimately influence central nervous system (CNS) motivational and affective processes via circulating mediators.

A dielectrophoretic method of discrimination between normal oral epithelium, and oral and oropharyngeal cancer in a clinical setting.

Despite the accessibility of the oral cavity to clinical examination, delays in diagnosis of oral and oropharyngeal carcinoma (OOPC) are observed in a large majority of patients, with negative impact on prognosis. Diagnostic aids might help detection and improve early diagnosis, but there remains little robust evidence supporting the use of any particular diagnostic technology at the moment. The aim of the present feasibility first-in-human study was to evaluate the preliminary diagnostic validity of a novel technology platform based on dielectrophoresis (DEP). DEP does not require labeling with antibodies or stains and it is an ideal tool for rapid analysis of cell properties. Cells from OOPC/dysplasia tissue and healthy oral mucosa were collected from 57 study participants via minimally-invasive brush biopsies and tested with a prototype DEP platform using median membrane midpoint frequency as main analysis parameter. Results indicate that the current DEP platform can discriminate between brush biopsy samples from cancerous and healthy oral tissue with a diagnostic sensitivity of 81.6% and a specificity of 81.0%. The present ex vivo results support the potential application of DEP testing for identification of OOPC. This result indicates that DEP has the potential to be developed into a low-cost, rapid platform as an assistive tool for the early identification of oral cancer in primary care; given the rapid, minimally-invasive and non-expensive nature of the test, dielectric characterization represents a promising platform for cost-effective early cancer detection.

Computational and mathematical modeling of the effects of tailbeat frequency and flexural stiffness in swimming fish.

In this paper we describe how we combine computational and mathematical models to form virtual fish to explore different hypotheses about the impact of centra. We show how we create simulation models using a combination of a mathematical model of a fish-like robot using caudal fin propulsion, a propulsion model, and an optimizer, to explore the impact of centra under various scenarios. The optimizer uses the mathematical model to construct valid configurations of the digital robot and uses the utility function and propulsion model to evaluate the performance of each configuration. The evaluations are used to explore the adaptive landscape and find high-performing configurations. Our results show that the high-performing configurations have both increased (flexural) stiffness of the tail and higher tailbeat frequencies.

Up-regulation of alternate co-stimulatory molecules on proinflammatory CD28null T cells in bronchiolitis obliterans syndrome.

Bronchiolitis obliterans syndrome (BOS) is associated with lack of immunosuppression of T cell proinflammatory cytokines and increased T cell granzyme B. Repeated antigen-driven proliferation down-regulates T cell CD28. We hypothesized that down-regulation of CD28 and up-regulation of alternate co-stimulatory molecules (CD134, CD137, CD152 and CD154) on T cells may be associated with BOS. Co-stimulatory molecules, granzyme B, perforin and intracellular cytokines were measured by flow cytometry on T cells from stable lung transplant patients (n = 38), patients with BOS (n = 20) and healthy controls (n = 10). There was a significant increase in the percentage of CD4/28(null) and CD8/28(null) T cells producing granzyme B, interferon (IFN)-γ and tumour necrosis factor (TNF)-α in BOS compared with stable patients. Down-regulation of CD28 was associated with steroid resistance and up-regulation of CD134, CD137, CD152 and CD154 on CD4(+) T cells and CD137 and CD152 on CD8(+) T cells. There was a significant correlation between increased CD28(null) /CD137 T cells producing IFN-γ, TNF-α with BOS grade (r = 0·861, P < 0·001 for CD28(null) /CD137 IFN-γ/CD8) and time post-transplant (r = 0·698, P < 0·001 for CD28(null) /CD137 IFN-γ/CD8). BOS is associated with down-regulation of CD28 and up-regulation of alternate co-stimulatory molecules on steroid-resistant peripheral blood proinflammatory CD4(+) and CD8(+) T cells. Therapeutic targeting of alternate co-stimulatory molecules on peripheral blood CD28(null) T cells and monitoring response using these assays may help in the management of patients with BOS.

Structural basis of the interaction of the breast cancer oncogene LMO4 with the tumour suppressor CtIP/RBBP8.

LIM-only protein 4 (LMO4) is strongly linked to the progression of breast cancer. Although the mechanisms underlying this phenomenon are not well understood, a role is emerging for LMO4 in regulation of the cell cycle. We determined the solution structure of LMO4 in complex with CtIP (C-terminal binding protein interacting protein)/RBBP8, a tumour suppressor protein that is involved in cell cycle progression, DNA repair and transcriptional regulation. Our data reveal that CtIP and the essential LMO cofactor LDB1 (LIM-domain binding protein 1) bind to the same face on LMO4 and cannot simultaneously bind to LMO4. We hypothesise that overexpression of LMO4 may disrupt some of the normal tumour suppressor activities of CtIP, thereby contributing to breast cancer progression.

Coronary artery spasm (CAS) simulating inferior ST elevation myocardial infarction (STEMI).

Coronary arteries vasospasm (CAS) is commonly seen in invasive cardiology laboratory during diagnostic catheterization or coronary intervention. Though the incidence of Printzmetal angina is uncommon, coronary vasospasm resulting in acute myocardial infarct is rare, especially if there is no significant atherosclerotic plaque within the coronary vasculature.

Efficacy of rituximab in refractory antisynthetase syndrome.

We report the successful use of repeated administration of rituximab in a patient with antisynthetase syndrome refractory to conventional immunosuppressive medications. A literature review revealed that previous experience with rituximab in this condition has been sparse. The rationale for the use of B-cell depleting therapies in antisynthetase syndrome has been explored in light of the current understanding of the pathogenesis of this condition.

fMRI language dominance and FDG-PET hypometabolism.

BACKGROUND: Atypical language dominance is common in patients with temporal lobe epilepsy. We examined the association of left temporal hypometabolism with laterality of fMRI activation in a language task in a cross-sectional study. METHODS: Thirty patients with temporal lobe epilepsy (mean age 32.4 ± 11.0 years [range 18-55]; epilepsy onset 15.3 ± 11.3 years [range 0.8-40]; 22 left focus, 8 right focus) had (18)fluoro-deoxyglucose (FDG)-PET using noninvasive cardiac input function. After MRI-based partial volume correction, regional glucose metabolism (CMRglc) was measured and asymmetry index, AI = 2(l - R)/(L + R), calculated. fMRI language dominance was assessed with an auditory definition decision paradigm at 3 T. fMRI data were analyzed in SPM2 using regions of interest from Wake Forest PickAtlas (Wernicke area [WA], inferior frontal gyrus [IFG], middle frontal gyrus [MFG]) and bootstrap laterality index, LI = (l - R/L + R). RESULTS: Nineteen patients had ipsilateral temporal hypometabolism; 3 of 4 patients with atypical language had abnormal FDG-PET. Increasing left midtemporal hypometabolism correlated with decreased MFG LI (r = -0.41, p < 0.05) and showed trends with WA LI (r = -0.37, p = 0.055) and IFG LI (r = -0.31, p = 0.099); these relationships became more significant after controlling for age at onset. Increasing hypometabolism was associated with fewer activated voxels in WA ipsilateral to the focus and more activated voxels contralaterally, but overall, activation amount in left WA was similar to subjects without left temporal hypometabolism (t = -1.39, p > 0.10). CONCLUSIONS: We did not find evidence of impaired blood oxygenation level-dependent response in hypometabolic cortex. Regional hypometabolism appears to be a marker for the temporal lobe dysfunction that leads to displacement of language function.

A rare coronary anatomy comprising dual (Type IV) left anterior descending arteries and an anomalous left circumflex artery from the right coronary artery.

We present the case of a rare coronary anomaly in a 64-year-old male who presented with exertional angina. The right coronary artery (RCA) was dominant, giving origin proximally to an anomalous left circumflex (LCX) artery and a left anterior descending (LAD) artery which supplied the conventional mid and distal LAD territory. The left main artery (LM) arose from the left coronary sinus and branched into a large first septal and an intermediate artery. There was associated non-critical atherosclerotic disease. We report this because of the rare division of the LAD area of supply by arteries from both coronary sinuses (dual LAD) with an anomalous LCX also arising from the proximal RCA. The clinical implications are discussed.