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1.
Cardiovasc Pathol ; 60: 107433, 2022.
Article in English | MEDLINE | ID: mdl-35588998

ABSTRACT

BACKGROUND: Whilst a combination of genetically mediated vulnerability and hemodynamic insult is suspected to contribute to bicuspid aortic valve (BAV) aortopathy, the underlying pathophysiological mechanisms are poorly understood. METHODS: Utilizing RT-qPCR, we compared the expression of 28 potentially relevant long non-coding RNA (lncRNA) in aortic tissue from BAV patients undergoing aortic surgery for aortopathy, to healthy controls. Relative lncRNA expression was measured using ΔΔCT, with fold-change calculated as RQ=2-ΔΔCT. RESULTS: When comparing samples from BAV patients (n=29, males n=25; median age 58 years, Q1-Q3 51-65, maximum aortic dimension 50±5 mm) with healthy controls (n=7; males n=4, P=.12; median age 39 years, Q1-Q3 18-47, P=.001), there were two differentially expressed lncRNA: TUG1 expression was significantly lower in BAV aortic tissue (RQ 0.59, 95% CI 0.50-0.69, P=.02), whilst MIAT expression was significantly higher (RQ 2.87, 95% CI 1.96-4.20, P=.01). Sensitivity analysis including only patients with normal BAV function showed similar trends of differential expression of TUG1 (RQ 0.69, 95% CI 0.50-0.90, P=.29) and MIAT (RQ 2.55, 95% CI 1.21-5.36, P=.29) compared to controls. CONCLUSIONS: LncRNA TUG1 and MIAT are differentially expressed in BAV aortopathy compared to healthy controls, independent of BAV hemodynamics. Aberrant lncRNA expression may be involved in the pathogenesis of BAV aortopathy.


Subject(s)
Bicuspid Aortic Valve Disease , Heart Valve Diseases , RNA, Long Noncoding , Adult , Aorta/pathology , Aortic Valve/pathology , Female , Heart Valve Diseases/pathology , Humans , Male , Middle Aged , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism
2.
Preprint in English | medRxiv | ID: ppmedrxiv-22273909

ABSTRACT

BackgroundMonitoring the emergence and spread of SARS-CoV-2 variants is an important public health objective. Travel restrictions, aimed to prevent viral spread, have major economic consequences and unclear effectiveness despite considerable research. We investigated the introduction and establishment of the Gamma variant in New York City (NYC) in 2021. MethodsWe performed phylogeographic analysis on 15,967 Gamma sequences available on GISAID and sampled between March 10th through May 1st, 2021, to identify geographic sources of Gamma lineages introduced into NYC. We identified locally circulating Gamma transmission clusters and inferred the timing of their establishment in NYC. FindingsWe identified 16 phylogenetically-distinct Gamma clusters established in NYC (cluster sizes ranged 2-108 genomes). Most of the NYC clusters were introduced from Florida and Illinois; only one was introduced from outside the United States (US). By the time the first Gamma case was reported by genomic surveillance in NYC on March 10th, the majority (57%) of circulating Gamma lineages had already been established in the city for at least two weeks. InterpretationDespite the expansion of SARS-CoV-2 genomic surveillance in NYC, there was a substantial gap between Gamma variant introduction and establishment in January/February 2021, and its identification by genomic surveillance in March 2021. Although travel from Brazil to the US was restricted from May 2020 through the end of the study period, this restriction did not prevent Gamma from becoming established in NYC as most introductions occurred from domestic locations.

3.
Singapore Med J ; 63(2): 61-67, 2022 02.
Article in English | MEDLINE | ID: mdl-32729311

ABSTRACT

The complete picture regarding transmission modes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unknown. This review summarises the available evidence on its transmission modes, our preliminary research findings and implications for infection control policy, and outlines future research directions. Environmental contamination has been reported in hospital settings occupied by infected patients, and is higher in the first week of illness. Transmission via environmental surfaces or fomites is likely, but decontamination protocols are effective in minimising this risk. The extent of airborne transmission is also unclear. While several studies have detected SARS-CoV-2 ribonucleic acid in air samples, none has isolated viable virus in culture. Transmission likely lies on a spectrum between droplet and airborne transmission, depending on the patient, disease and environmental factors. Singapore's current personal protective equipment and isolation protocols are sufficient to manage this risk.


Subject(s)
COVID-19 , SARS-CoV-2 , Hospitals , Humans , Infection Control/methods , Personal Protective Equipment
4.
Article in English | WPRIM (Western Pacific) | ID: wpr-927270

ABSTRACT

The complete picture regarding transmission modes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unknown. This review summarises the available evidence on its transmission modes, our preliminary research findings and implications for infection control policy, and outlines future research directions. Environmental contamination has been reported in hospital settings occupied by infected patients, and is higher in the first week of illness. Transmission via environmental surfaces or fomites is likely, but decontamination protocols are effective in minimising this risk. The extent of airborne transmission is also unclear. While several studies have detected SARS-CoV-2 ribonucleic acid in air samples, none has isolated viable virus in culture. Transmission likely lies on a spectrum between droplet and airborne transmission, depending on the patient, disease and environmental factors. Singapore's current personal protective equipment and isolation protocols are sufficient to manage this risk.


Subject(s)
Humans , COVID-19 , Hospitals , Infection Control/methods , Personal Protective Equipment , SARS-CoV-2
6.
Infect Control Hosp Epidemiol ; 42(11): 1327-1332, 2021 11.
Article in English | MEDLINE | ID: mdl-33487210

ABSTRACT

BACKGROUND: Understanding the extent of aerosol-based transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is important for tailoring interventions for control of the coronavirus disease 2019 (COVID-19) pandemic. Multiple studies have reported the detection of SARS-CoV-2 nucleic acid in air samples, but only one study has successfully recovered viable virus, although it is limited by its small sample size. OBJECTIVE: We aimed to determine the extent of shedding of viable SARS-CoV-2 in respiratory aerosols from COVID-19 patients. METHODS: In this observational air sampling study, air samples from airborne-infection isolation rooms (AIIRs) and a community isolation facility (CIF) housing COVID-19 patients were collected using a water vapor condensation method into liquid collection media. Samples were tested for presence of SARS-CoV-2 nucleic acid using quantitative real-time polymerase chain reaction (qRT-PCR), and qRT-PCR-positive samples were tested for viability using viral culture. RESULTS: Samples from 6 (50%) of the 12 sampling cycles in hospital rooms were positive for SARS-CoV-2 RNA, including aerosols ranging from <1 µm to >4 µm in diameter. Of 9 samples from the CIF, 1 was positive via qRT-PCR. Viral RNA concentrations ranged from 179 to 2,738 ORF1ab gene copies per cubic meter of air. Virus cultures were negative after 4 blind passages. CONCLUSION: Although SARS-CoV-2 is readily captured in aerosols, virus culture remains challenging despite optimized sampling methodologies to preserve virus viability. Further studies on aerosol-based transmission and control of SARS-CoV-2 are needed.


Subject(s)
COVID-19 , RNA, Viral , Hospitals , Humans , Polymerase Chain Reaction , RNA, Viral/genetics , SARS-CoV-2
7.
Infect Control Hosp Epidemiol ; 42(6): 669-677, 2021 06.
Article in English | MEDLINE | ID: mdl-33081858

ABSTRACT

BACKGROUND: The risk of environmental contamination by severe acute respiratory coronavirus virus 2 (SARS-CoV-2) in the intensive care unit (ICU) is unclear. We evaluated the extent of environmental contamination in the ICU and correlated this with patient and disease factors, including the impact of different ventilatory modalities. METHODS: In this observational study, surface environmental samples collected from ICU patient rooms and common areas were tested for SARS-CoV-2 by polymerase chain reaction (PCR). Select samples from the common area were tested by cell culture. Clinical data were collected and correlated to the presence of environmental contamination. Results were compared to historical data from a previous study in general wards. RESULTS: In total, 200 samples from 20 patient rooms and 75 samples from common areas and the staff pantry were tested. The results showed that 14 rooms had at least 1 site contaminated, with an overall contamination rate of 14% (28 of 200 samples). Environmental contamination was not associated with day of illness, ventilatory mode, aerosol-generating procedures, or viral load. The frequency of environmental contamination was lower in the ICU than in general ward rooms. Eight samples from the common area were positive, though all were negative on cell culture. CONCLUSION: Environmental contamination in the ICU was lower than in the general wards. The use of mechanical ventilation or high-flow nasal oxygen was not associated with greater surface contamination, supporting their use and safety from an infection control perspective. Transmission risk via environmental surfaces in the ICUs is likely to be low. Nonetheless, infection control practices should be strictly reinforced, and transmission risk via droplet or airborne spread remains.


Subject(s)
COVID-19/transmission , Cross Infection/transmission , Intensive Care Units , SARS-CoV-2 , Adult , Aged , Aged, 80 and over , COVID-19/prevention & control , Cross Infection/prevention & control , Cross Infection/virology , Decontamination/methods , Female , Humans , Male , Middle Aged , Patients' Rooms , Real-Time Polymerase Chain Reaction , Respiration, Artificial/adverse effects , Risk Factors
8.
Nat Commun ; 11(1): 2800, 2020 05 29.
Article in English | MEDLINE | ID: mdl-32472043

ABSTRACT

Understanding the particle size distribution in the air and patterns of environmental contamination of SARS-CoV-2 is essential for infection prevention policies. Here we screen surface and air samples from hospital rooms of COVID-19 patients for SARS-CoV-2 RNA. Environmental sampling is conducted in three airborne infection isolation rooms (AIIRs) in the ICU and 27 AIIRs in the general ward. 245 surface samples are collected. 56.7% of rooms have at least one environmental surface contaminated. High touch surface contamination is shown in ten (66.7%) out of 15 patients in the first week of illness, and three (20%) beyond the first week of illness (p = 0.01, χ2 test). Air sampling is performed in three of the 27 AIIRs in the general ward, and detects SARS-CoV-2 PCR-positive particles of sizes >4 µm and 1-4 µm in two rooms, despite these rooms having 12 air changes per hour. This warrants further study of the airborne transmission potential of SARS-CoV-2.


Subject(s)
Betacoronavirus/isolation & purification , Coronavirus Infections/virology , Environmental Microbiology , Patients' Rooms , Pneumonia, Viral/virology , Adult , COVID-19 , Coronavirus Infections/epidemiology , Coronavirus Infections/pathology , Coronavirus Infections/transmission , Cross-Sectional Studies , Female , Hospitals , Humans , Male , Middle Aged , Pandemics , Particle Size , Particulate Matter/analysis , Particulate Matter/chemistry , Pneumonia, Viral/epidemiology , Pneumonia, Viral/pathology , Pneumonia, Viral/transmission , SARS-CoV-2 , Time Factors
9.
Preprint in English | medRxiv | ID: ppmedrxiv-20046557

ABSTRACT

Understanding the particle size distribution in the air and patterns of environmental contamination of SARS-CoV-2 is essential for infection prevention policies. We aimed to detect SARS-CoV-2 surface and air contamination and study associated patient-level factors. 245 surface samples were collected from 30 airborne infection isolation rooms of COVID-19 patients, and air sampling was conducted in 3 rooms. Air sampling detected SARS-CoV-2 PCR-positive particles of sizes >4 {micro}m and 1-4 {micro}m in two rooms, which warrants further study of the airborne transmission potential of SARS-CoV-2. 56.7% of rooms had at least one environmental surface contaminated. High touch surface contamination was shown in ten (66.7%) out of 15 patients in the first week of illness, and three (20%) beyond the first week of illness (p = 0.010).

12.
Cells ; 9(2)2020 02 15.
Article in English | MEDLINE | ID: mdl-32075271

ABSTRACT

Although the influenza A virus H7N9 subtype circulates within several avian species, it can also infect humans with a severe disease outcome. To better understand the biology of the H7N9 virus we examined the host response to infection in avian and human cells. In this study we used the A/Anhui/1/2013 strain, which was isolated during the first wave of the H7N9 epidemic. The H7N9 virus-infected both human (Airway Epithelial cells) and avian (Chick Embryo Fibroblast) cells, and each infected host transcriptome was examined with bioinformatic tools and compared with other representative avian and human influenza A virus subtypes. The H7N9 virus induced higher expression changes (differentially regulated genes) in both cell lines, with more prominent changes observed in avian cells. Ortholog mapping of differentially expression genes identified significant enriched common and cell-type pathways during H7N9 infections. This data confirmed our previous findings that different influenza A virus subtypes have virus-specific replication characteristics and anti-virus signaling in human and avian cells. In addition, we reported for the first time, the new HIPPO signaling pathway in avian cells, which we hypothesized to play a vital role to maintain the antiviral state of H7N9 virus-infected avian cells. This could explain the absence of disease symptoms in avian species that tested positive for the presence of H7N9 virus.


Subject(s)
Influenza A Virus, H7N9 Subtype/physiology , Orthomyxoviridae Infections/genetics , Orthomyxoviridae Infections/virology , A549 Cells , Animals , Chick Embryo , Chickens , Dogs , Gene Expression , Humans , Influenza in Birds/genetics , Influenza in Birds/metabolism , Influenza in Birds/virology , Influenza, Human/genetics , Influenza, Human/metabolism , Influenza, Human/virology , Madin Darby Canine Kidney Cells , Orthomyxoviridae Infections/metabolism , Signal Transduction
13.
Trop Med Infect Dis ; 3(1)2018 Mar 12.
Article in English | MEDLINE | ID: mdl-30274428

ABSTRACT

Melioidosis is a notifiable infectious disease registered with the Ministry of Health (MOH) and Agri-Food & Veterinary Authority (AVA), Singapore. From a clinical perspective, increased awareness of the disease has led to early detection and treatment initiation, thus resulting in decreasing mortality rates in recent years. However, the disease still poses a threat to local pet, zoo and farm animals, where early diagnosis is a challenge. The lack of routine environmental surveillance studies also makes prevention of the disease in animals difficult. To date, there have been no reports that provide a complete picture of how the disease impacts the local human and animal populations in Singapore. Information on the distribution of Burkholderia pseudomallei in the environment is also lacking. The aim of this review is to provide a comprehensive overview of both published and unpublished clinical, veterinary and environmental studies on melioidosis in Singapore to achieve better awareness and management of the disease.

14.
J Ethnopharmacol ; 221: 30-36, 2018 Jul 15.
Article in English | MEDLINE | ID: mdl-29626673

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Mitragyna speciosa (Korth.) also known as kratom, is a native medicinal plant of Southeast Asia with opioid-like effects. Kratom tea/juice have been traditionally used as a folk remedy and for controlling opiate withdrawal in Malaysia. Long-term opioid use is associated with depletion in testosterone levels. AIM OF THE STUDY: Since kratom is reported to deform sperm morphology and reduce sperm motility, we aimed to clinically investigate the testosterone levels following long-term kratom tea/juice use in regular kratom users. METHODS: A total of 19 regular kratom users were recruited for this cross-sectional study. A full-blood test was conducted including determination of testosterone level, follicle stimulating hormone (FSH) and luteinizing hormone (LH) profile, as well as hematological and biochemical parameters of participants. RESULTS: We found long-term kratom tea/juice consumption with a daily mitragynine dose of 76.23-94.15 mg did not impair testosterone levels, or gonadotrophins, hematological and biochemical parameters in regular kratom users. CONCLUSION: Regular kratom tea/juice consumption over prolonged periods (>2 years) was not associated with testosterone impairing effects in humans.


Subject(s)
Follicle Stimulating Hormone/blood , Luteinizing Hormone/blood , Mitragyna , Plant Extracts/administration & dosage , Testosterone/blood , Adult , Beverages/analysis , Humans , Male , Phytochemicals/administration & dosage , Phytochemicals/analysis , Plant Extracts/analysis , Young Adult
15.
Clin Psychol Psychother ; 24(4): 1014-1027, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28008691

ABSTRACT

Functional Analytic Psychotherapy (FAP) is a behavioral psychotherapy intervention that emphasizes the development of an intimate and intense therapeutic relationship as the vehicle of therapeutic change. Recently, research has provided preliminary support for a FAP therapist training (FAPTT) protocol in enhancing FAP competency. The present study aimed to expand on this research by examining the effects of FAPTT on FAP-specific skills and competencies and a set of broadly desirable therapist qualities (labelled awareness, courage and love in FAPTT) in a sample of therapist trainees in Singapore. The study also evaluated the feasibility and acceptability of FAP in the Singaporean context. Twenty-five students enrolled in a master's in clinical psychology program were recruited and randomly assigned to receive either eight weekly sessions of a FAPTT course or to a waitlist condition. All participants completed measures assessing empathy, compassionate love, trait mindfulness, authenticity and FAP-specific skills and competencies pre- and post-training, and at 2-month follow-up. A post-course evaluation was administered to obtain participants' qualitative feedback. Results indicated that compared with the waitlisted group, FAPTT participants reported significant increases in overall empathy, FAP skill and treatment acceptability from pre- to post-training. Improvements were observed on several outcome variables at 2-month follow-up. Participants reported finding the training to be both feasible and acceptable, although several raised issues related to the compatibility of the treatment with the local cultural context. Overall, the findings suggest that FAPTT is effective for improving specific FAP competencies and selected broadly desirable therapist qualities among therapist trainees. Copyright © 2016 John Wiley & Sons, Ltd. KEY PRACTITIONER MESSAGE: Functional Analytic Therapy (FAP) therapist training protocol was effective in improving empathy and FAP skills among Singaporean therapist trainees. These improvements were maintained at 2-month follow-up. The training was found to be acceptable in the Singaporean context, although several adaptations were suggested to increase the compatibility between FAP principles and local cultural norms.


Subject(s)
Attitude of Health Personnel , Clinical Competence/statistics & numerical data , Education, Medical, Graduate/methods , Professional-Patient Relations , Psychoanalytic Therapy/education , Students, Medical/psychology , Adult , Empathy , Female , Humans , Love , Male , Mindfulness , Singapore , Young Adult
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