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Tom Wong

Bio: Tom Wong is an academic researcher from Health Canada. The author has contributed to research in topics: Syphilis & Population. The author has an hindex of 35, co-authored 150 publications receiving 5560 citations. Previous affiliations of Tom Wong include Harvard University & Public Health Agency of Canada.


Papers
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Journal ArticleDOI
18 Nov 1999-Nature
TL;DR: The results show that both systemic and local T-cell activation can lead to OPGL production and subsequent bone loss, and they provide a novel paradigm for T cells as regulators of bone physiology.
Abstract: Bone remodelling and bone loss are controlled by a balance between the tumour necrosis factor family molecule osteoprotegerin ligand (OPGL) and its decoy receptor osteoprotegerin (OPG)1,2,3. In addition, OPGL regulates lymph node organogenesis, lymphocyte development and interactions between T cells and dendritic cells in the immune system3,4,5. The OPGL receptor, RANK, is expressed on chondrocytes, osteoclast precursors and mature osteoclasts4,6. OPGL expression in T cells is induced by antigen receptor engagement7, which suggests that activated T cells may influence bone metabolism through OPGL and RANK. Here we report that activated T cells can directly trigger osteoclastogenesis through OPGL. Systemic activation of T cells in vivo leads to an OPGL-mediated increase in osteoclastogenesis and bone loss. In a T-cell-dependent model of rat adjuvant arthritis characterized by severe joint inflammation, bone and cartilage destruction and crippling, blocking of OPGL through osteoprotegerin treatment at the onset of disease prevents bone and cartilage destruction but not inflammation. These results show that both systemic and local T-cell activation can lead to OPGL production and subsequent bone loss, and they provide a novel paradigm for T cells as regulators of bone physiology.

1,843 citations

Journal ArticleDOI
TL;DR: This investigation investigated a possible cluster of SARS-CoV infections in healthcare workers who used contact and droplet precautions during attempted cardiopulmonary resuscitation of a SARS patient, and a systematic approach to the problem was outlined.
Abstract: Infection of healthcare workers with the severe acute respiratory syndrome–associated coronavirus (SARS-CoV) is thought to occur primarily by either contact or large respiratory droplet transmission. However, infrequent healthcare worker infections occurred despite the use of contact and droplet precautions, particularly during certain aerosol-generating medical procedures. We investigated a possible cluster of SARS-CoV infections in healthcare workers who used contact and droplet precautions during attempted cardiopulmonary resuscitation of a SARS patient. Unlike previously reported instances of transmission during aerosol-generating procedures, the index case-patient was unresponsive, and the intubation procedure was performed quickly and without difficulty. However, before intubation, the patient was ventilated with a bag-valve-mask that may have contributed to aerosolization of SARS-CoV. On the basis of the results of this investigation and previous reports of SARS transmission during aerosol-generating procedures, a systematic approach to the problem is outlined, including the use of the following: 1) administrative controls, 2) environmental engineering controls, 3) personal protective equipment, and 4) quality control.

249 citations

Journal ArticleDOI
Prithwish De1, Ameeta E. Singh, Tom Wong, W Yacoub, Ann M. Jolly 
TL;DR: The transmission of Neisseria gonorrhoeae in a localised outbreak in Alberta, Canada, is examined using measures of network centrality to determine the association between risk of infection of network members and their position within the sexual network.
Abstract: Objectives: Sexual partnerships can be viewed as networks in order to study disease transmission. We examined the transmission of Neisseria gonorrhoeae in a localised outbreak in Alberta, Canada, using measures of network centrality to determine the association between risk of infection of network members and their position within the sexual network. We also compared risk in smaller disconnected components with a large network centred on a social venue. Methods: During the investigation of the outbreak, epidemiological data were collected on gonorrhoea cases and their sexual contacts from STI surveillance records. In addition to traditional contact tracing information, subjects were interviewed about social venues they attended in the past year where casual sexual partnering may have occurred. Sexual networks were constructed by linking together named partners. Univariate comparisons of individual network member characteristics and algebraic measures of network centrality were completed. Results: The sexual networks consisted of 182 individuals, of whom 107 were index cases with laboratory confirmed gonorrhoea and 75 partners of index cases. People who had significantly higher information centrality within each of their local networks were found to have patronised a popular motel bar in the main town in the region (p = 0.05). When the social interaction through the bar was considered, a large network of 89 individuals was constructed that joined all eight of the largest local networks. Moreover, several networks from different communities were linked by individuals who served as bridge populations as a result of their sexual partnering. Conclusion: Asking clients about particular social venues emphasised the importance of location in disease transmission. Network measures of centrality, particularly information centrality, allowed the identification of key individuals through whom infection could be channelled into local networks. Such individuals would be ideal targets for increased interventions.

150 citations

Journal ArticleDOI
TL;DR: MSM recruited on-line who reported a new or casual sex partner(s) in the prior 3 months are at considerable risk of HIV or other sexually transmitted infections, but they are equally likely to report UAI whether sex partners were met on-lines or off-line.
Abstract: Objective: To assess whether men who have sex with men (MSM) are more likely to report unprotected anal intercourse (UAI) with partners met on-line compared with those met off-line. Methods: A total of 6122 individuals consented to participate in an anonymous behavioral survey on-line. This event-based analysis is limited to the 1683 men from the United States and Canada who had sex in the 3 months before the study and reported that their last sexual encounter included a new or casual male partner or partners. Prevalence and predictors of UAI were analyzed separately for the 386 men reporting more than 1 partner (multiple) and the 1297 men reporting only 1 (single) partner in their last encounter. Results: Of the 1683 MSM recruited on-line, 51% met their partner(s) in their last sexual encounter on-line and 23% reported UAI. No difference in risk for UAI was found for partners met on-line versus off-line in the bivariate or multivariate analyses. In a multivariate analysis of men with multiple-partner encounters, UAI was significantly associated with being HIV-seropositive (adjusted odds ratio [OR] = 2.87; P = 0.02) in a model that included age; education; whether partners were met on-line or off-line; and use of crystal methamphetamine, sildenafil, or alcohol before sex. Using the same model, significant predictors of UAI in men reporting a single-partner encounter were use of crystal methamphetamine (adjusted OR = 5.67; P = 0.001) and no college degree (adjusted OR = 1.63; P = 0.01). Conclusions: MSM recruited on-line who reported a new or casual sex partner(s) in the prior 3 months are at considerable risk of HIV or other sexually transmitted infections, but they are equally likely to report UAI whether sex partners were met on-line or off-line. The Internet may be an ideal venue for reaching high-risk MSM.

143 citations

Journal ArticleDOI
Noni MacDonald1, Tom Wong
TL;DR: The 2006 edition of the Canadian Guidelines on Sexually Transmitted Infections (STIs) is available online (at [www.phac-aspc.gc.ca/std-mts/sti\_2006/stI\_intro2006_e]) and in hard copy from the Canadian Public Health Association.
Abstract: The 2006 edition of the Canadian Guidelines on Sexually Transmitted Infections (STIs) is available online (at [www.phac-aspc.gc.ca/std-mts/sti\_2006/sti\_intro2006_e.html][1]) and in hard copy from the Canadian Public Health Association. For this edition, revision and chapter review followed an even

140 citations


Cited by
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01 Jun 2012
TL;DR: SPAdes as mentioned in this paper is a new assembler for both single-cell and standard (multicell) assembly, and demonstrate that it improves on the recently released E+V-SC assembler and on popular assemblers Velvet and SoapDeNovo (for multicell data).
Abstract: The lion's share of bacteria in various environments cannot be cloned in the laboratory and thus cannot be sequenced using existing technologies. A major goal of single-cell genomics is to complement gene-centric metagenomic data with whole-genome assemblies of uncultivated organisms. Assembly of single-cell data is challenging because of highly non-uniform read coverage as well as elevated levels of sequencing errors and chimeric reads. We describe SPAdes, a new assembler for both single-cell and standard (multicell) assembly, and demonstrate that it improves on the recently released E+V-SC assembler (specialized for single-cell data) and on popular assemblers Velvet and SoapDeNovo (for multicell data). SPAdes generates single-cell assemblies, providing information about genomes of uncultivatable bacteria that vastly exceeds what may be obtained via traditional metagenomics studies. SPAdes is available online ( http://bioinf.spbau.ru/spades ). It is distributed as open source software.

10,124 citations

Book ChapterDOI
01 Jan 2010

5,842 citations

Journal ArticleDOI
15 May 2003-Nature
TL;DR: Discovery of the RANK signalling pathway in the osteoclast has provided insight into the mechanisms of osteoporosis and activation of bone resorption, and how hormonal signals impact bone structure and mass.
Abstract: Osteoclasts are specialized cells derived from the monocyte/macrophage haematopoietic lineage that develop and adhere to bone matrix, then secrete acid and lytic enzymes that degrade it in a specialized, extracellular compartment. Discovery of the RANK signalling pathway in the osteoclast has provided insight into the mechanisms of osteoclastogenesis and activation of bone resorption, and how hormonal signals impact bone structure and mass. Further study of this pathway is providing the molecular basis for developing therapeutics to treat osteoporosis and other diseases of bone loss.

5,760 citations

Journal ArticleDOI
23 Feb 2001-Cell
TL;DR: The authors regret the inability to cite all of the primary literature contributing to this review due to length considerations, but wish to thank F. Chan, T. Migone, and J. Wang for insightful comments on the manuscript.

3,756 citations

Journal ArticleDOI
01 Sep 2000-Science
TL;DR: Osteopetrotic mutants have provided a wealth of information about the genes that regulate the differentiation of osteoclasts and their capacity to resorb bone.
Abstract: Osteoporosis, a disease endemic in Western society, typically reflects an imbalance in skeletal turnover so that bone resorption exceeds bone formation. Bone resorption is the unique function of the osteoclast, and anti-osteoporosis therapy to date has targeted this cell. The osteoclast is a specialized macrophage polykaryon whose differentiation is principally regulated by macrophage colony-stimulating factor, RANK ligand, and osteoprotegerin. Reflecting integrin-mediated signals, the osteoclast develops a specialized cytoskeleton that permits it to establish an isolated microenvironment between itself and bone, wherein matrix degradation occurs by a process involving proton transport. Osteopetrotic mutants have provided a wealth of information about the genes that regulate the differentiation of osteoclasts and their capacity to resorb bone.

3,604 citations