Biomedical subjects
Publications and source records attributed to G M McCarthy.
Concurrent joint infection with Mycobacterium tuberculosis (TB) and demonstration of intraarticular monosodium urate (MSU) crystals has not previously been reported. We describe a patient with chronic tophaceous gout from whose joints both TB and MSU crystals were isolated. We propose a mechanism to explain this condition.
OBJECTIVE: To investigate changes in the infection control practices, attitudes, and knowledge of dentists as they relate to HIV/AIDS: STUDY DESIGN: A comparison of responses to surveys conducted in 1992 (n = 258) and 1994 (n = 262) with the use of univariate/multivariate analyses and McNemar's test for paired data. RESULTS: The response rate were > 70%. There were significant increases in reports of continuing education related to HIV/AIDS, heat sterilization of handpieces, use of masks, and knowledge of risk of HIV infection after a needlestick injury. Significantly fewer respondents reported concerns about staff fears about HIV/AIDS: Reports of willingness to treat patients with HIV increased from 68% to 77%. The best predictors of willingness to treat changed from primarily infection control variables to lack of concern with respect to risk or loss of patients when treating persons with HIV. CONCLUSIONS: Increased use of infection control procedures and knowledge may be partly attributable to the introduction of mandatory continuing education in 1993.
Recent advances in understanding the pathogenesis and mechanisms whereby calcium crystals contribute to cartilage damage are highlighted in this review. Studies that help elucidate pathologic crystal formation in cartilage are discussed. The effect of calcium pyrophosphate dihydrate crystals on the progression of joint degeneration in vivo is noted. Early-onset osteoarthritis and chondrocalcinosis are linked to chromosome 8q. A syndrome of chondrocalcinosis associated with recurrent childhood seizures is linked to chromosome 5p. An unusual destructive and hypertrophic arthropathy of the atlantoaxial joint in calcium pyrophosphate dihydrate crystal deposition disease is described.
We surveyed 5,997 dentists in Ontario to investigate gender differences in the characteristics, infection control practices, knowledge and attitudes regarding the treatment of HIV-infected patients. The response rate was 70.3%. Reports indicated that female dentists are younger and more likely to work in larger urban centres (P < 0.00001), and in general practice (P < 0.0001) than their male counterparts. Multiple logistic regression analyses indicated that many significant gender differences in the univariate analyses could be explained by the confounding influence of age, practice location, and specialty; however, some differences remain significant: Women were more likely than men to report attending continuing education dealing with HIV/AIDS in the past two years (P < 0.001), and to use masks and eye protection (P < 0.00001). Men reported more economic concerns than women: they were more concerned about the financial burden of infection control costs (P < 0.00001), and losing patients from their practice if it is known that they treat patients with HIV (P < 0.05). However, there were no significant differences in willingness to provide treatment for patients with HIV. We conclude that there is little evidence to show that access to oral care for patients with HIV is affected by gender differences.
This preliminary, descriptive study investigated the behavior and attitudes of HIV-infected patients concerning dental care. A self-administered, anonymous questionnaire was completed by 101 of 102 consecutive HIV-infected adults (mean age 36 years). Since the diagnosis of HIV infection, 81 respondents reported that they had sought dental care; 54 reported visiting a dentist at least once a year; 41 had changed dentists; and 62 reported current mouth problems, for which 45 were receiving treatment. Forty per cent of all respondents were receiving treatment in a hospital dental department. The use of hospital facilities was not associated with advanced HIV disease. Seventy per cent of participants were satisfied with the dental treatment they had received since they were diagnosed with HIV (18 per cent had no opinion, and 12 per cent were dissatisfied). Twelve per cent were concerned that their HIV seropositivity would not be kept confidential. While 87 per cent of participants had disclosed their HIV-seropositivity to their current dentist, 29 per cent believed that the dentist could be reluctant to provide treatment if they did so. Some patients reported changing dentists or not seeking care based on their fear that dentists would be reluctant to provide treatment. Fifteen per cent of patients who had sought dental care reported that they were refused treatment because they had HIV. Participants were more likely to have received dental care within the previous year if they reported being able to afford treatment, or had dental insurance (p < 0.01). Because more than 33 per cent of respondents had incomes below the poverty line, it is likely that economic factors limit the access to dental care for patients with HIV. More research is required using a larger sample and a random selection of participants.
We describe 3 patients with non-insulin-dependent diabetes mellitus who presented with hand pain and swollen joints. All 3 had radiographic changes in the affected joints typical of those associated with hemochromatosis. None of these patients had hemochromatosis. This is the first description of hemochromatosis-like arthropathy in diabetes mellitus without hemochromatosis.
These recent meetings emphasized the considerable progress that has been made in HIV/AIDS. The prospect for non-progression of the disease, improved management of complications arising from the condition, and the potential for additional progress were the hallmarks of these meetings. The considerable developments that have occurred make it necessary for the dental profession to continue to play a role in the recognition, diagnosis, and management of oral conditions, and to keep abreast of the considerable developments in this field-and the implications that these developments have for patients presenting with complications related to other conditions, which may include bacterial, fungal or viral infections and malignant disease.
OBJECTIVE: To investigate reports of nondisclosure of HIV-seropositivity to dentists by HIV-infected patients and their rejection for dental treatment. STUDY DESIGN: An anonymous self-administered questionnaire was completed by 101 consecutive consenting HIV-infected patients. RESULTS: Eighty percent of respondents (mean age, 36 years) had visited a dentist since their HIV diagnosis; 15% of these reported that they had been refused treatment because the dentist did not want to treat HIV-infected patients. Rejection was reported by 25% of respondents with heterosexual and 14% with homosexual risk factors, 11% of recipients of blood or blood products, and 8% with unknown or multiple risk factors. Refusal was not associated with economic factors. Nondisclosure of HIV-seropositivity to their current dentist was reported by 13% of respondents. No respondents attending hospitals or health units reported nondisclosure, compared with 18% of respondents attending private dental offices (p < 0.05). CONCLUSION: More research is required with a larger sample to improve generalizability and to permit subgroup analysis.
Synovial fluid basic calcium phosphate (BCP) crystals are associated with severe destructive arthropathies characterised by synovial proliferation and non-inflammatory degradation of intra-articular collagenous structures. BCP crystals stimulate fibroblast and chondrocyte mitogenesis, metalloprotease secretion and prostaglandin production. As a tissue protective effect of prostaglandins has been suggested, we recently studied the effect of PGE1 on BCP crystal-induced mitogenesis and collagenase mRNA accumulation in human fibroblasts (HF). We demonstrated a dose-dependent inhibition of BCP crystal-induced mitogenesis and collagenase mRNA accumulation. The mechanism of PGE1 inhibition of BCP crystal-induced mitogenesis and collagenase mRNA accumulation was therefore explored. PGE1 (100 ng/ml) increased HF intracellular cAMP 40-fold over control. BCP alone caused no such change but inhibited the PGE1-induced increase in intracellular cAMP by at least 60%. The PGE1-induced increase in intracellular cAMP was also blocked by the adenyl cyclase inhibitor, 2',5'-dideoxyadenosine (ddA) (10 microM) and ddA reversed the PGE1-mediated inhibition of BCP crystal-induced mitogenesis. Dibutyryl cAMP also inhibited BCP crystal-induced mitogenesis in a concentration-dependent manner. Agents which increase intracellular cAMP levels such as the adenyl cyclase activator forskolin and the phosphodiesterase, inhibitor 3-isobutyl-1-methylxanthine (IBMX) mimicked the effect of PGE1 on HF collagenase mRNA levels. PGE1 inhibits the biologic effects of BCP crystals through the cAMP signal transduction pathway and such inhibition may have significant therapeutic implications.
Synovial fluid basic calcium phosphate (BCP) crystals are associated with severe destructive arthropathy. BCP crystals induce the secretion of matrix-degrading enzymes such as collagenase. No prophylactic or therapeutic agents are recognized to ameliorate the cartilage damage associated with BCP deposits in joints. As a chondroprotective effect of prostaglandins (PG) has been suggested, we studied the effect of misoprostol, a PGE1 analogue, on BCP crystal-induced mitogenesis and collagenase messenger RNA (mRNA) accumulation in human fibroblasts (HF). Mitogenesis was determined by 3H-thymidine incorporation assays and collagenase mRNA accumulation by Northern blot analysis, in HF stimulated with BCP crystals in the presence or absence of misoprostol. Misoprostol caused concentration-dependent inhibition of BCP crystal-induced mitogenesis. The inhibition of BCP-stimulated mitogenesis was not specific as misoprostol also inhibited the mitogenic response to 10% serum. There was only 50 (+/-5)% inhibition of serum-induced mitogenesis by misoprostol at 500 ng/ml, the concentration that completely inhibited BCP crystal-induced mitogenesis. Misoprostol also inhibited the accumulation of collagenase mRNA in BCP-stimulated HF by 63%. These data suggest that misoprostol may inhibit the synovial proliferation and cartilage degradation that accompany BCP crystal deposition.
We describe a 33-year-old woman with acute calcific periarthritis (ACP) of the interphalangeal joint of the thumb and review 42 reported cases of ACP involving the finger joints. A computer assisted literature search for reported cases of ACP involving the finger joints was performed. Clinical features of our case and those fulfilling the criteria for entry into this study were analyzed.
OBJECTIVE: To investigate BCP (basic calcium phosphate) crystal-stimulated mitogenesis and collagenase gene transcription in primary cultures of porcine chondrocytes. METHODS: The role of protein kinases in BCP crystal-stimulated DNA synthesis was investigated using thymidine incorporation, kinase inhibitors, and protein kinase C (PKC) assays. Northern blot analysis was used to determine the levels of collagenase c-fos and c-jun message. RESULTS: BCP crystals stimulated chondrocyte proliferation in a PKC-dependent manner. Increased levels of collagenase message were preceded by an increased accumulation of c-fos, but not c-jun. CONCLUSION: BCP crystals could contribute to the abnormal chondrocyte proliferation and collagenase secretion observed in some rheumatic diseases.
Synovial fluid basic calcium phosphate crystals (BCP) are often found in severely degenerated joints. Crystalline BCP is a growth factor stimulating fibroblast mitogenesis and acting as a competence factor similar to platelet-derived growth factor. In human fibroblasts (HF), the synthesis of collagenase and stromelysin is coordinately induced after stimulation with a variety of cytokines and growth factors. We sought to determine whether BCP, like other growth factors, might induce proteases that would damage articular tissue. Northern blot analysis of mRNA for collagenase and stromelysin in HF stimulated with BCP was performed. Secreted enzymes were analyzed by immunoblot using a monoclonal antibody to collagenase and by immunoprecipitation using a polyclonal antibody to stromelysin. Stromelysin activity was confirmed using casein substrate gels. A significant, dose-dependent accumulation of collagenase and stromelysin message was evident after 4 h and continued for at least 24 h in BCP-stimulated cultures. Forty-nine and 54 kD proteins immunoreacting with collagenase antibody were identified in the conditioned media (CM) from BCP-stimulated cultures while 50 and 55 kD proteins were identified by immunoprecipitation with stromelysin antibody. Collagenase activity was increased significantly in the CM from BCP treated cells; casein substrate gels showed casein degrading bands at molecular weights consistent with stromelysin. BCP stimulates coordinate induction of collagenase and stromelysin which may mediate the joint destruction associated with these crystals.
This prospective cohort study investigated orofacial pain occurring as a manifestation of vincristine neurotoxicity. Forty cancer patients (28 to 63 years of age) receiving vincristine were given baseline interviews and orofacial examinations, which were repeated weekly for 7 weeks of treatment. Twenty-two patients (55%) had neurotoxicity manifesting as orofacial pain. Onset was usually 3 days after vincristine administration; mean duration was 2 days. Twenty patients (50%) were affected in the first week: nine (22%) with severe and five (12%) with moderate pain. Symptoms were mild and infrequent in subsequent weeks. Eighteen control patients receiving chemotherapy without vincristine had no comparable orofacial symptoms. Multiple sites in the distribution of the trigeminal and glossopharyngeal nerves were affected: primarily the temporomandibular joint, mandible, throat, ears, and mandibular teeth. The frequency of orofacial pain increased with younger age. Pain was significantly associated with smaller body surface area (p less than 0.05), indicating a dose-related toxicity, and with sociodemographic variables including smoking (p less than 0.05).
Human immunodeficiency virus (HIV)-related oral candidiasis affects approximately one third of HIV-seropositive patients and more than 90% of patients with AIDS. It is necessary to identify patients who have a greater risk of candidiasis developing, so that interventions can be designed to reduce the frequency. This is particularly important because there is evidence that Candida species are immunosuppressive and therefore candidiasis may adversely affect the prognosis of patients with HIV. Susceptibility to HIV-related oral candidiasis is associated with xerostomia, severity of disease, depression of cell-mediated immunity, and older age (greater than 35 years). The frequency of HIV-related oral candidiasis is notably increased when the CD4 lymphocyte count falls to less than 300 cells/mm3. Xerostomia appears to be a better predictor of HIV-related oral candidiasis than CD4 count and should be prevented (e.g., by avoiding xerogenic drugs) and treated, when necessary, to minimize the risk of oral candidiasis.
The National Institutes of Health recently recommended research initiatives to investigate oral complications of cancer chemotherapy. This prospective cohort study investigated orofacial complications of combination chemotherapy (cyclophosphamide, methotrexate, fluorouracil, vincristine, and prednisone) in women with breast cancer. Thirty-four patients were given baseline interviews and examinations. Each patient was given weekly orofacial examinations and biweekly interviews for the first seven cycles of cytotoxic treatment. The orofacial complications included neurotoxicity caused by vincristine, mucositis, and candidiasis. Neurotoxicity affected 22 of 34 (65%) patients, was significantly associated with age less than 50 years (p less than 0.05), and manifested as pain in 19 of 34 (56%) patients. Mucositis affected 7 of 34 (21%) patients and was significantly associated with the occurrence of lesions of the oral mucosa at baseline examination; and smaller body surface area--indicating a dose-related toxicity (p less than 0.05). In four of the patients with mucositis (57%) granulocytopenia developed during the 7 days after the onset of mucositis. Intraoral candidiasis affected 4 of 34 (12%) patients.
Dietary fish oil supplementation can induce several metabolic changes relevant to rheumatic diseases. Both experimental and clinical evidence show that dietary fish oil supplementation modulates inflammatory and immune responses. Many studies have shown beneficial, albeit modest, effects in the treatment of rheumatoid arthritis. Studies in murine models of systemic lupus erythematosus have been encouraging, but few studies have been performed to assess the effects of dietary fish oil in the human disease or in other systemic rheumatic diseases. Further study on the efficacy of dietary fish oil supplementation in the treatment of specific rheumatic diseases is warranted.
Topical capsaicin 0.075% was evaluated for the treatment of the painful joints of rheumatoid arthritis (RA) and osteoarthritis (OA) in a 4 week double blind, placebo controlled randomized trial. Twenty-one patients were selected, all of whom had either RA (n = 7) or OA (n = 14) with painful involvement of the hands. Assessments of pain (visual analog scale), functional capacity, morning stiffness, grip strength, joint swelling and tenderness (dolorimeter) were performed before randomization. Treatment was applied to each painful hand joint 4 times daily with reassessment at 1, 2 and 4 weeks after entry. One subject did not complete the study. Capsaicin reduced tenderness (p less than 0.02) and pain (p less than 0.02) associated with OA, but not RA as compared with placebo. A local burning sensation was the only adverse effect noted. These findings suggest that topical capsaicin is a safe and potentially useful drug for the treatment of painful OA of the hands.