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Biomedical subjects

G M McCarthy

Publications and source records attributed to G M McCarthy.

At least 37 records · Page 2Linked to original sources
PubMed1999

Factors associated with refusal to treat HIV-infected patients: the results of a national survey of dentists in Canada.

OBJECTIVES: This study investigated dentists refusal to treat patients who have HIV. METHODS: A survey was mailed to a random sample of all licensed dentists in Canada, with 3 follow-up attempts (n = 6444). Data were weighted to allow for probability of selection and nonresponse and analyzed with Pearson's chi 2 and multiple logistic regression. RESULTS: The response rate was 66%. Of the respondents, 32% had knowingly treated HIV-infected patients in the last year; 16% would refuse to treat HIV-infected patients. Respondents reported willingness to treat HIV-infected patients (81%), injection drug users (86%), hepatitis B virus-infected patients (87%), homosexual and bisexual persons (94%), individuals with sexually transmitted disease(s) (94%), and recipients of blood and blood products (97%). The best predictors of refusal to treat patients with HIV were lack of ethical responsibility (odds ratio = 9.0) and items related to fear of cross-infection or lack of knowledge of HIV. CONCLUSIONS: One in 6 dentists reported refusal to treat HIV-infected patients, which was associated primarily with respondents' lack of belief in an ethical responsibility to treat patients with HIV and fears related to cross-infection. These results have implications for undergraduate, postgraduate, and continuing education.

Adult↗
PubMed1999

Dentists and HIV.

Explore the source record for details and available documents.

Attitude of Health Personnel↗
PubMed1999

Infection control practices across Canada: do dentists follow the recommendations?

This study investigated provincial and territorial differences in dentists' compliance with recommended infection control practices in Canada (1995). Questionnaires were mailed to a stratified random sample of 6,444 dentists, of whom 66.4% responded. Weighted analyses included Pearson's chi-square test and multiple logistic regression. Significant provincial and territorial differences included testing for immune response after hepatitis B virus (HBV) vaccination, HBV vaccination for all clinical staff, use of infection control manuals and post-exposure protocols, biological monitoring of heat sterilizers, handwashing before treating patients, using gloves and changing them after each patient, heat-sterilizing handpieces between patients, and using masks and uniforms to protect against splatter of blood and saliva. Excellent compliance (compliance with a combination of 18 recommended infection control procedures) ranged from 0% to 10%; the best predictors were more hours of continuing education on infection control in the last two years, practice location in larger cities (> 500,000) and sex (female). Clearly, improvements in infection control are desirable for dentists in all provinces and territories. Extending mandatory continuing education initiatives to include infection control may promote better compliance with current recommendations.

Canada↗
PubMed1998

Molecular mechanism of basic calcium phosphate crystal-induced activation of human fibroblasts. Role of nuclear factor kappab, activator protein 1, and protein kinase c.

Synovial fluid basic calcium phosphate (BCP) crystals are markers of severe joint degeneration in osteoarthritis. BCP crystals cause mitogenesis of articular cells and stimulate matrix metalloprotease production, thus promoting degradation of articular tissues. Previous work suggested that BCP crystal-induced cell activation required intracellular crystal dissolution, induction of proto-oncogene expression, and activation of signal transduction pathways involving protein kinase C and mitogen-activated protein kinases. Here we further elucidate the mechanisms of BCP crystal-induced cell activation as BCP crystals activate transcription factors nuclear factor kappaB and activator protein 1 in human fibroblasts. We confirm the role of protein kinase C in BCP crystal-induced mitogenesis in human fibroblasts. In contrast, we demonstrate that BCP crystals do not activate signal transduction pathways involving protein tyrosine kinases or phosphatidylinositol 3-kinase. These data further define the mechanism of cell activation by BCP crystals and confirm its selectivity, an observation that may have therapeutic implications.

3T3 Cells↗
PubMed1998

Improved compliance with recommended infection control practices in the dental office between 1994 and 1995.

OBJECTIVE: To investigate changes in Ontario dentists' infection control practices between 1994 and 1995. METHODS: Data from responses of 4003 dentists to a 1994 survey and responses of 987 dentists to a 1995 survey were compared by using descriptive statistics from all respondents and McNemar's test for paired data from those participating in both surveys. RESULTS: Response rates were 70% (1994) and 62% (1995). There were improvements in reports of routine use of gloves (92% to 94%); masks (73% to 79%); and protective eyewear (83% to 84%); vaccination for hepatitis B virus (HBV) or naturally acquired immunity of dentists (93% to 94%); HBV vaccination of clinical staff (64% to 77%); heat sterilization of handpieces (83% to 95%); and no extra precautions for patients with HIV (13% to 48%). Pairwise comparison of data for 788 dentists participating in both surveys showed statistically significant increases in reports of all practices except use of protective eyewear. The 1995 follow-up data also indicated low compliance with handwashing (74% before treating each patient; 62% after removing gloves); flushing water lines after treating each patient (54%); and using postexposure protocol for needlesticks and cuts (36%). CONCLUSIONS: Dentists' reports of compliance with recommended infection control practices and universal precautions against HBV and HIV infection increased between 1994 and 1995, but most dentists apparently have not adopted universal precautions. More education is needed to promote universal precautions, HBV vaccination for clinical staff, handwashing, and postexposure protocol.

Dental Offices↗
PubMed1998

A comparison of infection control practices of different groups of oral specialists and general dental practitioners.

OBJECTIVE: The purpose of this study was to compare the infection control practices of general dentists and dental specialty groups. METHODS: A survey was mailed to 5997 dentists in 1994; the response rate was 70%. The data were analyzed with multiple logistic regression (reference group: general dentists). RESULTS: When sociodemographic influences were taken into consideration, significant predictors of routine infection control practices included all of the following characteristics (odds ratios are in parentheses): 1. Gloves: being younger than 40 years of age (4.5) and being female (5.9). 2. Using gloves and changing gloves after each patient: being younger than 40 years of age (4.0), being female (3.0), being an oral surgeon (3.6), and being an orthodontist (0.2). 3. Using gloves, masks, and protective eyewear: being younger than 40 years of age (2.5), being female (2.3), and being an orthodontist, oral physician, or oral pathologist (0.2). 4. Hepatitis B vaccination for the practitioner: being younger than 40 years of age (5.1). 5. Hepatitis B vaccination for all clinical staff members: being younger than 40 years of age (1.2), being an oral surgeon (1.7), and being an orthodontist (0.6). 6. Heat sterilization of handpieces: being younger than 40 years of age (1.5), being an oral surgeon (5.4), and being an orthodontist (0.2). 7. Taking no additional precautions for patients with HIV: being younger than 40 years of age (1.7), being a periodontist (2.6), being a pedodontist (2.3), and being an oral physician/oral pathologist (4.3). CONCLUSION: Improved compliance with recommended infection control procedures is required for all groups and is particularly necessary for orthodontists.

Adult↗
PubMed1998

Risk factors associated with mucositis in cancer patients receiving 5-fluorouracil.

Oral mucositis is a dose-limiting toxicity of 5-fluorouracil (5-FU). This prospective cohort study investigated factors associated with mucositis in patients receiving 5-FU for cancer of the digestive tract. Sixty-three patients (mean age 65 years) completed self-administered questionnaires and had interviews, oral examinations and unstimulated whole salivary flow measurements at baseline and follow-up appointments. The duration of follow-up was 2 months. Predictor variables included sociodemographic data, body surface area, diabetes, smoking, alcohol consumption, salivary flow, oral hygiene, presence of prostheses, performance status, regimen of cytotoxic drugs, hematological data, and herpes simplex virus antibody titer. Forty-six per cent of patients developed at least one episode of oral mucositis during cytotoxic treatment. Pearson's chi-square analysis showed that mucositis was significantly associated with xerostomia at baseline, xerostomia during chemotherapy, and lower baseline neutrophil counts (P < or = 0.05). Multiple logistic regression analysis indicated that xerostomia at baseline (odds ratio, OR = 10.0), or baseline neutrophil level under 4000 cells/mm3 (OR = 3.9) were significant predictors of mucositis. Taking into account the effect of neutrophil level at baseline, xerostomia during chemotherapy (OR = 4.5) was also a significant predictor of mucositis. The results showed that xerostomia and lower baseline neutrophil levels are significantly associated with oral mucositis. These variables should be taken into consideration in the design of intervention studies to reduce the frequency and severity of mucositis. More research is required to investigate the role of saliva and neutrophils in the pathogenesis of chemotherapy-induced mucositis.

Adult↗
PubMed1998

Basic calcium phosphate crystal-induced collagenase production: role of intracellular crystal dissolution.

OBJECTIVE: To investigate the potential therapeutic effects of inhibiting intracellular dissolution of basic calcium phosphate (BCP) crystals in tissue culture by raising lysosomal pH using bafilomycin A1, a specific vacuolar pump inhibitor. DESIGN: 45Ca-labeled crystals were used to demonstrate intracellular crystal dissolution in human foreskin fibroblasts (HF). Mitogenesis was evaluated using [3H]thymidine incorporation assays and cell counts. Northern blot and Western blot were used to study collagenase [matrix metalloproteinase-1 (MMP1)] mRNA accumulation and protein secretion, respectively. RESULTS: Bafilomycin A1 inhibited intracellular dissolution of BCP crystals and caused a concentration-dependent inhibition of BCP crystal-induced mitogenesis. Doses of bafilomycin A1 which inhibited intracellular crystal dissolution and mitogenesis had no effect on BCP crystal-induced MMP1 mRNA accumulation or protein secretion. CONCLUSION: Raising lysosomal pH to inhibit intracellular BCP crystal dissolution attenuates the proliferative response to BCP crystals in HF but does not prevent metalloprotease synthesis and secretion. The therapeutic potential of lysosomotropic agents for preventing joint destruction in BCP crystal deposition disease is limited.

Anti-Bacterial Agents↗
PubMed1998

Basic calcium phosphate crystals induce synthesis and secretion of 92 kDa gelatinase (gelatinase B/matrix metalloprotease 9) in human fibroblasts.

OBJECTIVE: Synovial fluid basic calcium phosphate (BCP) crystals are associated with severe joint degeneration accompanied by synovial hypertrophy. The metalloprotease 92 kDa gelatinase (MMP-9) has been implicated in the degradation of extracellular matrix in osteoarthritis, but the ability of BCP crystals to induce gelatinase in human fibroblasts or in adult porcine chondrocytes has not previously been studied. The hypothesis that the mitogenic response to BCP crystals is accompanied by induction and secretion of MMP-9 was studied. METHODS: MMP-9 messenger RNA (mRNA) was detected by northern blot and reverse transcription-polymerase chain reaction (RT-PCR). Gelatinase secretion was identified by western blot and zymography of conditioned media. RESULTS: BCP crystals caused a concentration dependent induction of MMP-9 mRNA accumulation and protein secretion in human fibroblasts but not in adult porcine chondrocytes. CONCLUSION: BCP crystals induce MMP-9 production by HF but not adult porcine chondrocytes. Fibroblast MMP-9 may be an important mediator of the joint destruction associated with synovial fluid BCP crystals.

Animals↗
PubMed1997

Infection control in the orthodontic office in Canada.

Because of the difficulty of identifying infected persons, current recommendations for infection control are to treat all patients as if they are infected with blood-borne pathogens such as human immunodeficiency virus (HIV) and the hepatitis viruses. Dentists' compliance with these recommendations has been investigated previously, however, there are few data related to orthodontists. The objective of this study was to measure the proportion of orthodontists who report the use of recommended infection control procedures and to compare the infection control practices of orthodontists and general dentists. A mailed survey with three follow-up attempts was administered to all orthodontists and general dentists in Ontario (N = 5441) in 1994. There were significant differences in the routine use of gloves (orthodontists 85%, general dentists 92%); masks (orthodontists 38%, general dentists 75%); protective eyewear (orthodontists 60%, general dentists 84%); changing gloves after each patient (orthodontists 84%, general dentists 96%); and heat sterilization of handpieces (orthodontists 57%, general dentists 84%). Hepatitis B virus (HBV) vaccination of all clinical staff was reported by 46% of orthodontists, compared with 61% of general dentists (p < 0.001). Reports of HBV vaccination of orthodontists (94%) and general dentists (92%) were not significantly different. The use of additional precautions for patients with HIV was reported by 80% of orthodontists and 78% of general dentists. More education is required to promote the use of universal precautions by both general practitioners and orthodontists. Increased use of barrier methods, HBV vaccination of clinical staff, and heat sterilization of handpieces is required to reduce the potential for cross infection in the orthodontic practice. This is particularly important with the increasing number of microorganisms that are resistant to antibiotics.

Acquired Immunodeficiency Syndrome↗
PubMed1997

The infection control practices of general dental practitioners.

OBJECTIVES: To investigate the infection control practices of general dentists in Ontario in 1994. DESIGN: Confidential coded questionnaires were mailed to all general dental practitioners in Ontario (n = 5,176), with three follow-up attempts. Data were analyzed using Pearson's chi-squared test and multiple logistic regression. SETTING: Offices of general dental practitioners in Ontario. PARTICIPANTS: General dental practitioners actively involved in treating patients. RESULTS: The response rate adjusted for nondelivery was 70%. A high proportion of respondents reported using gloves (always, 91.8%; sometimes, 7.8%), masks (always, 74.8%; sometimes, 21.1%), or protective eyewear (always, 83.6%; sometimes, 13%); heat sterilization of handpieces (83.9%); and hepatitis B (HBV) vaccination of dentists (92.3%). However, only 61.4% of respondents reported HBV vaccination of all clinical staff, and 87.7% used additional precautions for patients with human immunodeficiency virus (HIV). Significant predictors of the use of recommended infection control procedures (i.e., always using gloves, masks, and eye protection; heat sterilization of handpieces; HBV vaccination for dentist and staff; and no extra precautions for patients with HIV) were age < 40 years (odds ratio [OR], 2.6), lack of concern regarding increased personal risk (OR, 2.0) or costs of infection control procedures (OR, 1.5), and knowledge of the low infectivity of HIV after a needlestick injury (OR, 2.0) and that infection control procedures for HBV are adequate for HIV (OR, 2.7). CONCLUSION: Additional education is required to promote a more realistic perception of risk of HIV transmission in the dental office and the use of all recommended infection control practices, including Universal Precautions.

Adult↗
PubMed1997

Nonresponse bias in a national study of dentists' infection control practices and attitudes related to HIV.

The aim was to investigate late response and nonresponse bias in a survey related to HIV and infection control. Questionnaires with ID numbers were mailed to a stratified random sample of dentists in Canada with additional mailings 4 and 7 weeks later (n = 6444). We compared responses received after < 4 weeks, 4-7 weeks, > 7 weeks. Extrapolation was used to estimate nonresponse bias. Univariate analyses showed significant differences between responses received < 4 weeks after initial mailing and those received later for items on sociodemographics, knowledge, infection control practices and attitudes: late responders were more likely to report that they would refuse to treat any patients with HIV (P < 0.01). Multiple logistic regression indicated that the best predictors of responses received > or = 4 weeks were disagreement that HBV is more infectious than HIV (OR = 1.7); unwillingness to attend a dentist who treats HIV/AIDS patients (OR = 1.3); incorrect perception of the risk of HIV infection after an HIV-contaminated needlestick injury (OR = 1.2); and sometimes or never heat-sterilizing handpieces after each patient (OR = 1.2). Extrapolation indicated that the percentage of all respondents who reported refusal to treat (15.2%) would have been 17.1% if a 100% response rate had been obtained. We found significant evidence of late response and nonresponse bias primarily in knowledge and fears related to HIV infectivity; however, the impact on the final results was small and we concluded that additional follow-up to improve response rates would not be worthwhile.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Nonresponse bias in a survey of Ontario dentists' infection control and attitudes concerning HIV.

OBJECTIVE: This study investigated late response and nonresponse bias in an HIV-related survey of dentists. METHODS: Questionnaires with ID numbers were mailed to all dentists in Ontario (N = 5,997) with additional mailings four and seven weeks later. RESULTS: Proportionately more respondents who returned questionnaires less than four weeks after the first mailing reported that they knowingly treated (P < .05) or were willing to treat HIV-infected patients (P < .05); that they had an accurate perception of risk of HIV infection after a needlestick injury (P < .01), and preferred not to refer HIV-infected patients (P < .01). Linear extrapolation of cumulative percent responses indicated nonresponse bias in terms of attitude and knowledge items; however, the magnitude was low. CONCLUSIONS: The effects of late response and nonresponse bias on the results of this study were small. However, these results cannot be generalized beyond the study population, and obtaining high response rates and testing for nonresponse bias in surveys of attitudes related to HIV are recommended.

Acquired Immunodeficiency Syndrome↗