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1.
Tropical Biomedicine ; : 462-470, 2023.
Article in English | WPRIM (Western Pacific) | ID: wpr-1011362

ABSTRACT

@#Bats are flying mammals with unique immune systems that allow them to hold many pathogens. Hence, they are recognised as the reservoir of many zoonotic pathogens. In this study, we performed molecular detection to detect coronaviruses, paramyxoviruses, pteropine orthoreoviruses and dengue viruses from samples collected from insectivorous bats in Krau Reserve Forest. One faecal sample from Rhinolophus spp. was detected positive for coronavirus. Based on BLASTN, phylogenetic analysis and pairwise alignment-based sequence identity calculation, the detected bat coronavirus is most likely to be a bat betacoronavirus lineage slightly different from coronavirus from China, Philippines, Thailand and Luxembourg. In summary, continuous surveillance of bat virome should be encouraged, as Krau Reserve Forest reported a wide spectrum of biodiversity of insectivorous and fruit bats. Moreover, the usage of primers for the broad detection of viruses should be reconsidered because geographical variations might possibly affect the sensitivity of primers in a molecular approach.

2.
Trop Biomed ; 40(4): 462-470, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-38308834

ABSTRACT

Bats are flying mammals with unique immune systems that allow them to hold many pathogens. Hence, they are recognised as the reservoir of many zoonotic pathogens. In this study, we performed molecular detection to detect coronaviruses, paramyxoviruses, pteropine orthoreoviruses and dengue viruses from samples collected from insectivorous bats in Krau Reserve Forest. One faecal sample from Rhinolophus spp. was detected positive for coronavirus. Based on BLASTN, phylogenetic analysis and pairwise alignment-based sequence identity calculation, the detected bat coronavirus is most likely to be a bat betacoronavirus lineage slightly different from coronavirus from China, Philippines, Thailand and Luxembourg. In summary, continuous surveillance of bat virome should be encouraged, as Krau Reserve Forest reported a wide spectrum of biodiversity of insectivorous and fruit bats. Moreover, the usage of primers for the broad detection of viruses should be reconsidered because geographical variations might possibly affect the sensitivity of primers in a molecular approach.


Subject(s)
Chiroptera , Coronavirus Infections , Coronavirus , Animals , Coronavirus/genetics , Animals, Wild , Phylogeny , Genome, Viral
3.
Clin Radiol ; 77(7): 503-513, 2022 07.
Article in English | MEDLINE | ID: mdl-35365295

ABSTRACT

Physiological and pathological processes arising from the breast and anterior chest wall may share similar clinical presentations because of the small volume of male breasts. Therefore, imaging is frequently required to localise and characterise the lesion and guide biopsy when radiological findings are equivocal or suspicious. Mammography or digital breast tomosynthesis (DBT) and ultrasound are the mainstays of breast imaging work-up. Other imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI) and positron-emission tomography (PET) can sometimes augment the investigation and aid treatment planning. This article reviews the key imaging features of a wide spectrum of benign and malignant conditions that involve the male breast and anterior chest wall across various age groups. Familiarisation with the salient radiological findings is essential for reaching an accurate diagnosis and optimising management.


Subject(s)
Breast Neoplasms , Thoracic Wall , Adolescent , Breast/diagnostic imaging , Breast/pathology , Breast Neoplasms/pathology , Child , Humans , Male , Mammography/methods , Radiographic Image Enhancement/methods , Thoracic Wall/diagnostic imaging , Tomography, X-Ray Computed/methods , Young Adult
4.
Osteoporos Int ; 32(2): 301-309, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32827276

ABSTRACT

We conducted a large, retrospective cohort study using data from Taiwan's National Health Insurance Research Database to evaluate whether the risk of developing osteoporosis is associated with sepsis. Our study found that adults younger than 65 years with sepsis had a significantly increased risk of developing osteoporosis. INTRODUCTION: There have been limited studies regarding the osteoporosis risk associated with sepsis. Our purpose is to evaluate whether the risk of developing osteoporosis is associated with sepsis. METHODS: We conducted a large, retrospective cohort study using data from Taiwan's National Health Insurance Research Database. From the insurance claims data, a total of 13,178 patients diagnosed with sepsis from 2000 to 2012 were included in the sepsis cohort, and a propensity score-matched cohort included 13,178 individuals without sepsis. To calculate the incidence of osteoporosis, both groups were followed until 2013. Cox regression analysis was performed to obtain the hazard ratios (HRs) to assess the risk of developing osteoporosis. The Kaplan-Meier method was used to estimate the cumulative incidence of osteoporosis. RESULTS: The overall incidences of osteoporosis (per 1,000 person-years) in the sepsis and non-sepsis groups were 10.2 and 10.7, respectively. The risk of osteoporosis significantly increased in the presence of sepsis (adjusted HR = 1.17, 95% confidence interval (CI) = 1.04-1.31). The risk of osteoporosis in the sepsis group was significantly higher than that in the non-sepsis group for young patients aged 20-49 years and patients aged 50-64 years (adjusted HR = 1.93, 95% CI = 1.08-3.44; adjusted HR = 2.01, 95% CI = 1.52-2.65, respectively). The Kaplan-Meier curves of cumulative probability also showed a significantly increased risk of osteoporosis in patients aged 20-49 years and aged 50-64 years with sepsis compared with non-sepsis (P = 0.025; P < 0.001, respectively). CONCLUSION: Adults younger than 65 years with sepsis had a significantly increased risk of developing osteoporosis.


Subject(s)
Osteoporosis , Sepsis , Adult , Cohort Studies , Humans , Incidence , Middle Aged , Osteoporosis/epidemiology , Osteoporosis/etiology , Proportional Hazards Models , Retrospective Studies , Risk Factors , Sepsis/complications , Sepsis/epidemiology , Taiwan/epidemiology , Young Adult
5.
Sci Rep ; 10(1): 568, 2020 01 17.
Article in English | MEDLINE | ID: mdl-31953476

ABSTRACT

Sub-optimal nutrition and dental caries are both common with significant short and long-term implications for child health and development. We applied twin statistical methods to explore the relationship between body mass index (BMI) and dental caries. We measured BMI at 18 months and six years of age and cumulative dental caries experience at six years in 344 twin children. Dental caries in primary teeth was categorised into 'any' or 'advanced' and BMI was analysed as both a continuous and categorical variable. Statistical analyses included multiple logistic regression using generalized estimating equations and within/between-pair analyses. There was no association between BMI and 'any' dental caries experience at either time-point, neither overall nor in within/between pair analyses. However, 'advanced' dental caries at six years was associated with a within-pair difference in BMI of -0.55 kg/m2 (95% CI -1.00, -0.11, p = 0.015). A within-pair increase of 1 kg/m2 in BMI was associated with a lower within-pair risk of advanced dental caries (OR 0.68, 95% CI 0.52, 0.90, p = 0.007). These findings reveal a possible causal relationship between lower BMI and dental caries. As dental outcomes were only measured at one time point, the direction of this potentially causal relationship is unclear.


Subject(s)
Dental Caries/epidemiology , Diseases in Twins/epidemiology , Body Mass Index , Child , Female , Humans , Infant , Logistic Models , Male , Nutritional Status
6.
Malays Fam Physician ; 14(3): 18-27, 2019.
Article in English | MEDLINE | ID: mdl-32175037

ABSTRACT

BACKGROUND: Colorectal cancer (CRC) is the second most common cancer in Malaysia. Awareness of risk factors, symptoms and warning signs of CRC will help in early detection. This paper presents the level of CRC awareness among the urban population in Malaysia. METHOD: A cross-sectional study was conducted from November 2015 till December 2016 at three government clinics in the Klang Valley. The validated Bowel Cancer Awareness Measure questionnaire in both English and Malay was used. The mean knowledge scores for the warning signs and risk factors of CRC in different socio-demographic groups were compared using ANOVA in SPSS version 23. Statistical significance was set at p<0.05 and a 95% confidence level. RESULTS: Of the 426 respondents, 29.1% were unable to recall the warning signs and symptoms of CRC. Average recall was less than two warning signs and symptoms (mean 1.62, SD 1.33). The mean total knowledge score for CRC was 9.91 (SD 4.78), with a mean knowledge scores for warning signs and risk factors at 5.27 (SD 2.74) and 4.64 (SD 2.78), respectively. Respondents with a higher level of education were found to have higher level of knowledge regarding the warning signs of CRC. There was a significant positive association between knowledge score for warning signs and level of confidence in detecting warning signs. Regarding the total knowledge score for CRC, 3.3% of respondents scored zero. For warning signs and risk factors, 8.2% and 8.5% of respondents had zero knowledge scores, respectively. CONCLUSIONS: Generally, awareness of CRC is poor among the urban population of Klang Valley. Greater education and more confidence in detecting warning signs are significantly associated with better knowledge of warning signs. CRC awareness programs should be increased to improve awareness.

7.
J Dent Res ; 98(1): 77-83, 2019 01.
Article in English | MEDLINE | ID: mdl-30074848

ABSTRACT

The etiology of hypomineralized second primary molars (HSPM) is unclear, but genetic and environmental factors have been proposed. The aim of this study was to investigate the relative contribution of genes and environment to the etiology of HSPM and to identify potential environmental risk factors in a longitudinal twin cohort. Children from twin pregnancies ( N = 250) were recruited antenatally, and detailed demographic, health, and phenotypic data were collected at recruitment, 24- and 36-wk gestation, birth, and 18 mo of age. 25-Hydroxyvitamin D was quantified for mothers at 28-wk gestation and infants at birth. Dental examinations were conducted on the twins at 6 y of age to determine the presence, severity, and extent of HSPM per standardized criteria. To investigate associations of environmental risk factors with HSPM, multiple logistic regression models were fitted with generalized estimating equations to adjust for twin correlation. Within- and between-pair analyses were performed for unshared continuous variables: birthweight and birth 25-hydroxyvitamin D. Twin-twin concordance for monozygotic (MZ) and dizygotic (DZ) pairs was calculated and compared after adjusting for identified risk factors. A total of 344 twins underwent the 6-y-old dental assessment; HSPM occurred in 68 (19.8%). After adjusting for potential confounders, vitamin D levels at birth, infantile eczema, dizygosity, in vitro fertilization, socioeconomic position, and maternal smoking beyond the first trimester of pregnancy demonstrated the strongest associations with HSPM. Overall concordance for HSPM was 0.47 (95% CI, 0.32 to 0.62) with weak evidence ( P = 0.078) of higher concordance in MZ twins (0.63; 95% CI, 0.38 to 0.89) as compared with DZ twins (0.41; 95% CI, 0.24 to 0.58). After adjusting for known risk factors, there was no evidence ( P = 0.172) for an additive genetic influence. These findings suggest that shared and unshared environmental factors, such as maternal smoking later in pregnancy and infantile eczema, are important in the etiology of HSPM.


Subject(s)
Dental Enamel Hypoplasia/epidemiology , Tooth, Deciduous , Twins, Dizygotic/statistics & numerical data , Twins, Monozygotic/statistics & numerical data , Australia , Child , Dental Enamel Hypoplasia/etiology , Female , Humans , Molar , Pregnancy , Prevalence , Prospective Studies
8.
Opt Express ; 25(21): 26067-26075, 2017 Oct 16.
Article in English | MEDLINE | ID: mdl-29041268

ABSTRACT

Generating N single photons simultaneously is a formidable challenge due to the lack of deterministic single photon sources. Recent work [New J. Phys. 19, 063013 (2017] has proposed a relative multiplexing scheme that can enhance the N single photons probability with a minimum of active switching resources. We experimentally demonstrate relative temporal multiplexing on two photon sources with a 90% additional enhancement over the standard temporal multiplexing scheme demonstrated previously. 88 ± 11% visibility of Hong-Ou-Mandel quantum interference verifies the indistinguishability of the heralded single photons after the synchronization. This proof-of-principle demonstration points out the potential significance of the relative multiplexing scheme for large-scale photonic quantum information processing.

9.
Nat Commun ; 7: 10853, 2016 Mar 21.
Article in English | MEDLINE | ID: mdl-26996317

ABSTRACT

It is a fundamental challenge in quantum optics to deterministically generate indistinguishable single photons through non-deterministic nonlinear optical processes, due to the intrinsic coupling of single- and multi-photon-generation probabilities in these processes. Actively multiplexing photons generated in many temporal modes can decouple these probabilities, but key issues are to minimize resource requirements to allow scalability, and to ensure indistinguishability of the generated photons. Here we demonstrate the multiplexing of photons from four temporal modes solely using fibre-integrated optics and off-the-shelf electronic components. We show a 100% enhancement to the single-photon output probability without introducing additional multi-photon noise. Photon indistinguishability is confirmed by a fourfold Hong-Ou-Mandel quantum interference with a 91 ± 16% visibility after subtracting multi-photon noise due to high pump power. Our demonstration paves the way for scalable multiplexing of many non-deterministic photon sources to a single near-deterministic source, which will be of benefit to future quantum photonic technologies.

10.
Child Care Health Dev ; 42(3): 297-312, 2016 May.
Article in English | MEDLINE | ID: mdl-26860873

ABSTRACT

BACKGROUND: Children born before full term (39-41 weeks' gestation) are at increased risk of adverse cognitive outcomes. Risk quantification is important as late-preterm (LPT; 34-36 weeks) and early-term (ET; 37-38 weeks) births are common. METHOD: This review analyses the effect of LPT and ET births on long-term cognitive and educational outcomes. The primary outcome was general cognitive ability. Secondary outcomes included verbal/non-verbal intelligence quotient, subject-specific school performance and special educational needs. The search strategy included Medline and Embase from January 1975 to June 2013. Eligible studies investigated specified outcomes and included suitable gestational age participants assessed at 2 years and older. Outcome measures and socio-demographic descriptors were extracted, and data meta-analysed where possible. RESULTS: Eight studies compared ET birth with full-term birth. Fourteen studies compared LPT birth with either term birth (>37 weeks, n = 12 studies) or full-term birth (39-41 weeks, n = 2 studies). Substantial between-study heterogeneity existed. LPT and ET children underperformed in most outcomes compared with their term/full-term counterparts, respectively. For example, LPT children had an increased risk of lower general cognitive ability (adjusted risk ratio 1.38 [95% confidence interval 1.06-1.79]), and full-term children performed 5% of a standard deviation higher (z-score 0.05 [0.02, 0.08]) than ET children. Poorer outcomes persist into adulthood; term cohorts performed 5% of a standard deviation higher than LPT cohorts (z-score 0.05 [0.04, 0.07]), and full-term cohorts performed 3% of a standard deviation higher than ET cohorts (z-score 0.03 [0.02, 0.04]). CONCLUSION: This review critically examines the knowledge around long-term cognitive outcomes of LPT and ET births, demonstrating multiple, small, adverse differences between LPT/ET and term/full-term births.


Subject(s)
Child Behavior Disorders/psychology , Cognition Disorders/etiology , Cognition Disorders/psychology , Infant, Premature, Diseases/etiology , Infant, Premature/psychology , Child Behavior Disorders/etiology , Child Behavior Disorders/physiopathology , Child, Preschool , Cognition Disorders/physiopathology , Early Intervention, Educational/methods , Humans , Infant , Infant, Newborn , Infant, Premature, Diseases/physiopathology , Infant, Premature, Diseases/psychology , Odds Ratio
11.
Clin Radiol ; 68(12): 1268-75, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23953005

ABSTRACT

Tracheomalacia, tracheobronchomalacia, and excessive dynamic airway collapse are all terms used to describe tracheal narrowing in expiration. The first two describe luminal reduction from cartilage softening and the latter refers to luminal reduction from exaggerated posterior membrane movement. Expiratory tracheal narrowing is a frequent occurrence that can cause symptoms of airway obstruction, such as dyspnoea, wheeze, and exercise intolerance. The accurate diagnosis and quantification of expiratory tracheal narrowing has important aetiological, therapeutic, and prognostic implications. The reference standard for diagnosis has traditionally been bronchoscopy; however, this method has significant limitations. Expiratory tracheal disorders are readily detected by four-dimensional dynamic volume multidetector computed tomography (4D-CT), an emerging, non-invasive method that will potentially enable detection and quantification of these conditions. This review discusses the morphological forms of expiratory tracheal narrowing and demonstrates the utility of 4D-CT in the diagnosis, quantification, and treatment of these important conditions.


Subject(s)
Tracheal Diseases/diagnostic imaging , Exhalation/physiology , Four-Dimensional Computed Tomography , Humans , Terminology as Topic , Trachea/diagnostic imaging , Trachea/pathology , Trachea/physiopathology , Tracheal Diseases/pathology , Tracheal Diseases/physiopathology , Tracheobronchomalacia/diagnostic imaging , Tracheobronchomalacia/pathology , Tracheobronchomalacia/physiopathology , Tracheomalacia/diagnostic imaging , Tracheomalacia/pathology , Tracheomalacia/physiopathology
12.
J Vis Commun Med ; 35(2): 50-8, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22747263

ABSTRACT

AIM: To investigate the use of anaglyphs and stereograms for three-dimensional imaging of the external nose. METHOD: Red-cyan anaglyphs and colour stereograms created from stereo photographs of patients with nasal deformity were compared to standard photographs. Assessors rated images on 'life-likeness' of imaging, contour definition and utility for surgical planning. RESULTS: 9 patients were recruited. Stereograms provided significantly improved life-like features and definition of nasal structure, with some benefit for pre-operative planning. Less benefit was found for anaglyph images. Oblique views proved most effective. CONCLUSIONS: Stereograms provide simple, inexpensive three-dimensional images of the nose, with potential uses in operative analysis, medicolegal documentation, teaching and research.


Subject(s)
Imaging, Three-Dimensional/instrumentation , Nose/abnormalities , Photography/instrumentation , Humans , Image Processing, Computer-Assisted/instrumentation , Image Processing, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Photography/methods , Software
13.
Br J Oral Maxillofac Surg ; 50(5): 410-6, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22000023

ABSTRACT

The aim of this cross-sectional survey was to ask patients about the financial burden of having head and neck cancer, and to explore its relation with health-related quality of life (HRQoL). In the Mersey region 447/752 eligible patients (59%) responded to the questionnaire. There was no obvious response bias. The most notable financial costs of head and neck cancer that were a moderate or large burden to patients were petrol (25%, 112), home heating (24%, 108), change in the type of food (21%, 95), and loss of earnings (20%, 88). During the previous week 15% (63/423) had lost a moderate or large amount of income because of their medical condition. In terms of taking care of their financial needs, 10% (40) were moderately dissatisfied and 15% (61) very dissatisfied. Patients with worse physical and social emotional functioning experienced more notable financial burden, more difficult life circumstances in the past month and greater financial difficulty and loss in income due to their condition in the previous week, more dissatisfaction with how well they took care of their own financial needs and were more likely to have sought statutory benefits. Cancer of the head and neck has a serious impact on financial aspects of patients' lives and seems to be associated with a poor HRQoL. Multidisciplinary teams can do much more to address the cost of having treatment by recognising need earlier, and giving advice and access to appropriate benefits.


Subject(s)
Cost of Illness , Head and Neck Neoplasms/economics , Health Services Needs and Demand/economics , Income/statistics & numerical data , Quality of Life , Aged , Aged, 80 and over , Employment/economics , Female , Head and Neck Neoplasms/psychology , Health Care Surveys , Humans , Logistic Models , Male , Middle Aged , Retirement/economics , Surveys and Questionnaires , United Kingdom
14.
Clin Otolaryngol ; 35(1): 13-7, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20447157

ABSTRACT

BACKGROUND: Oilseed rape production is widespread in cereal growing areas. Many patients attending our clinics for seasonal allergy claim that they are allergic to it. AIM: To determine the prevalence of oilseed rape allergy in our population. POPULATION: General population within a mixed cereal farming area attending a rhinology and allergy clinic in a district general hospital, UK. METHODS & MATERIALS: Retrospective chart analysis. The results of 1475 consecutive patients who underwent skin prick allergy testing over a 2-year period (January 2003-December 2005) and of 640 consecutive patients over a 1-year period (September 2008-September 2009) were analysed and compared. RESULTS: Allergy to house dust mite was found to be most common (n = 526, 25%) followed by grass pollen (n = 519, 24%) and cereals (n = 429, 20%). Oilseed rape hypersensitivity was relatively uncommon, comprising only 2% of the population tested (n = 28). CONCLUSION: Oilseed rape does not cause significant allergy, even in areas of high production. It is likely that those patients exhibiting oilseed rape allergy may in fact be symptomatic due to the effect of other allergens, acting either synergistically with the oilseed rape allergen, or more likely, in spite of it.


Subject(s)
Brassica napus/adverse effects , Edible Grain , Environmental Exposure/adverse effects , Rhinitis, Allergic, Seasonal/epidemiology , Rhinitis, Allergic, Seasonal/therapy , Rural Population/statistics & numerical data , Environmental Monitoring , Epidemiological Monitoring , Humans , Retrospective Studies , United Kingdom/epidemiology
15.
J Laryngol Otol ; 123(1): 123-5, 2009 Jan.
Article in English | MEDLINE | ID: mdl-18854059

ABSTRACT

OBJECTIVE: The aim of this paper is to describe a novel technique of improving the nasal airflow in patients in whom, despite reduction surgery to the inferior turbinates (either alone or with septal surgery), the nasal airways remain compromised because of obstruction occurring anterior to the inferior turbinate, due to a prominent nasal process of the maxilla at the pyriform aperture. METHOD: We describe a novel approach to resection of the nasal process of the maxilla, a technique performed in 40 patients with either: residual obstructive symptoms following septal surgery with or without turbinate surgery; and significant inspiratory alar collapse. The same technique was also used in two patients to improve the intranasal approach to the medial and anterior maxilla during endoscopic medial maxillectomy for recurrent inverted papilloma. RESULTS: Patients reported a subjective improvement in their nasal airways, with resolution of inspiratory alar collapse. This technique significantly improved intranasal access in the two patients with inverted papilloma. CONCLUSION: This technique confers significant subjective improvement of nasal airways patency in selected patients, and improves endoscopic surgical access to clear inverted papilloma.


Subject(s)
Maxilla/surgery , Nasal Obstruction/surgery , Nasal Septum/surgery , Osteotomy, Le Fort/methods , Papilloma, Inverted/surgery , Rhinoplasty/methods , Humans , Maxilla/physiopathology , Nasal Obstruction/physiopathology , Nasal Septum/physiopathology , Osteotomy, Le Fort/standards , Papilloma, Inverted/physiopathology , Rhinoplasty/standards
16.
Acta Biomater ; 4(5): 1569-75, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18400573

ABSTRACT

In bone fracture healing, the extent to which the injured bone regains stability and strength depends on the mechanical properties of the tissues that are formed during healing. While many techniques have been used to quantify the overall mechanical behavior of fracture calluses, few data exist on the material properties of individual callus tissues. The overall goal of this study was to quantify these material properties. Nanoindentation was performed at multiple locations across thin (200mum), longitudinal sections of rat fracture callus at 35 days post fracture. Following indentation, sections were stained with alizarin red S and alcian blue to obtain semi-quantitative estimates of tissue mineral content and proteoglycan content, respectively. Indentation moduli varied over three orders of magnitude (0.61-1010MPa) throughout the callus. Much of this variation was due to the presence of multiple tissue types: the indentation moduli of granulation tissue, chondroid tissue and woven bone ranged 0.61-1.27MPa (median=0.99MPa), 1.39-4.42MPa (median=2.89MPa) and 26.92-1010.00MPa (median=132.00MPa), respectively. In regions of alizarin red staining, the indentation modulus was correlated (r=0.62, P=0.04) with stain intensity, suggesting a positive correlation between modulus and mineral content in woven bone. In addition, the indentation modulus of woven bone along the periosteal aspect of the cortex increased with distance from the fracture gap (P=0.004). These results demonstrate the usefulness of nanoindentation in characterizing the elastic properties of the heterogeneous mixture of tissues present in bone fracture callus.


Subject(s)
Bony Callus/physiopathology , Femoral Fractures/physiopathology , Fracture Healing/physiology , Hardness Tests/methods , Nanotechnology/methods , Animals , Bony Callus/pathology , Elasticity , Femoral Fractures/pathology , Male , Rats , Rats, Sprague-Dawley , Stress, Mechanical
18.
Virology ; 349(2): 463-75, 2006 Jun 05.
Article in English | MEDLINE | ID: mdl-16490225

ABSTRACT

The initial interaction between mosquito-borne flavivirus West Nile and mosquito cells is poorly characterized. This study analyzed the endocytic and the associated signaling pathway that mediate the infectious entry of West Nile virus (WNV) into mosquito cell line (C6/36). Pretreatment of C6/36 cells with pharmacological drugs that blocks clathrin-mediated endocytosis significantly inhibited virus entry. Furthermore, the transfection of functional blocking antibody against clathrin molecules and the overexpression of dominant-negative mutants of Eps15 in C6/36 cells caused a marked reduction in WNV internalization. WNV was shown to activate focal adhesion kinase (FAK) to facilitate the endocytosis of virus but not the mitogen-activated protein kinases (ERK1 and ERK2). Subsequent to the internalization of WNV, the virus particles are translocated along the endosomal pathway as revealed by double-immunofluorescence assays with anti-WNV envelope protein and cellular markers for early and late endosomes. Specific inhibitor for protein kinase C (PKC) was shown to be highly effective in blocking WNV entry by inhibiting endosomal sorting event. The disruption of the microtubule network using nocodazole also drastically affects the entry process of WNV but not the disruption of actin filaments by cytochalasin D. Finally, a low-pH-dependent step is required for WNV infection as revealed by the resistance of C6/36 cells to WNV infection in the presence of lysosomotropic agents.


Subject(s)
Aedes/virology , Endocytosis , West Nile virus/physiology , Actin Cytoskeleton/drug effects , Actin Cytoskeleton/metabolism , Animals , Antigens, Viral/analysis , Cadaverine/analogs & derivatives , Cadaverine/pharmacology , Cell Line , Chlorpromazine/pharmacology , Clathrin/genetics , Clathrin/physiology , Cytochalasin D/pharmacology , Endosomes/virology , Enzyme Inhibitors/pharmacology , Filipin/pharmacology , Focal Adhesion Protein-Tyrosine Kinases/analysis , Intracellular Signaling Peptides and Proteins/genetics , Microscopy, Confocal , Microscopy, Fluorescence , Microtubules/drug effects , Microtubules/metabolism , Mitogen-Activated Protein Kinases/analysis , Nocodazole/pharmacology , Protein Kinase C/antagonists & inhibitors , Sucrose/pharmacology
19.
Virology ; 339(2): 249-60, 2005 Sep 01.
Article in English | MEDLINE | ID: mdl-15992848

ABSTRACT

This study isolated and characterized the West Nile virus (WNV) putative receptor molecule(s) from Aedes albopictus mosquito (C6/36) cells. The binding of WNV to C6/36 cells was saturated with 5000 particles per cell. The entry of WNV into C6/36 cells was strongly inhibited when pretreated with proteinase K and to a lesser extent with sodium periodate. However, pretreatment of C6/36 cells with phospholipases, glycosidases, heparinases and neurimidase had no effect on virus entry. By using virus overlay protein blot assay, WNV was observed to bind to the 140-kDa, 95-kDa, 70-kDa and 55-kDa plasma membrane-associated molecules isolated from C6/36 cells. Murine antibodies generated against the 95-kDa and 70-kDa membrane proteins effectively blocked WNV, Japanese encephalitis virus (JEV) and Dengue virus (DV) serotype 2 infection in C6/36 cells. In addition, the binding of the recombinant-WNV envelope domain III protein to C6/36 cells can be inhibited by the anti-95-kDa and anti-70-kDa membrane protein antibodies. These data strongly supported the possibility that the 95-kDa and 70-kDa plasma membrane-associated proteins are part of a receptor complex for mosquito-borne flaviviruses (WNV, JEV and DV) on mosquito cells.


Subject(s)
Aedes/metabolism , Membrane Proteins/metabolism , West Nile Fever/metabolism , West Nile virus/physiology , Aedes/cytology , Aedes/virology , Animals , Cell Line , Cell Membrane/metabolism , Culicidae , Gene Expression , Protein Binding
20.
J Laryngol Otol ; 119(5): 348-51, 2005 May.
Article in English | MEDLINE | ID: mdl-15949096

ABSTRACT

The objective of this study was to assess the efficacy of topical lignocaine in reducing the pain of pack removal after nasal surgery. Fifty-eight patients with Merocel nasal packs in situ after nasal surgery were randomized to receive 10 ml of either 2 per cent lignocaine or 0.9 per cent saline on the packs 10 minutes prior to their removal and the pain experienced on their removal was recorded on a visual analogue scale. The median pain score was 3.4 in the lignocaine group and 2.9 in the saline group with no statistical evidence of a difference between the two groups. There was no statistical evidence of an association between the group and the operation performed, the use of intra-operative Moffat's solution or the use of post-operative oral analgesia. We conclude that lignocaine used in this way does not reduce the pain of pack removal after nasal surgery.


Subject(s)
Anesthetics, Local/administration & dosage , Lidocaine/administration & dosage , Nose/surgery , Postoperative Care/methods , Tampons, Surgical , Administration, Topical , Adult , Aged , Aged, 80 and over , Double-Blind Method , Female , Humans , Male , Middle Aged , Pain Measurement/methods , Pain, Postoperative/drug therapy , Prospective Studies
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