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Biomedical subjects

I W Fong

Publications and source records attributed to I W Fong.

At least 37 records · Page 2Linked to original sources
PubMed1997

Asymptomatic oral carriage of Candida albicans in patients with HIV infection.

OBJECTIVE: To assess the relationship of asymptomatic carriage of Candida albicans and clinically apparent thrush in patients with HIV infection. DESIGN: Prospective, longitudinal, controlled study. SETTING: The HIV clinic at St. Michael's Hospital, University of Toronto. PARTICIPANTS: One hundred and twenty-seven patients with HIV-infection were divided into 3 groups according to the CD4+ lymphocyte count, and 37 healthy volunteers served as controls. INTERVENTIONS: Determination of blood type, baseline CD4+ lymphocyte count in patients with HIV infection, and immunophenotyping. Samples of saliva (2 mL) were obtained from each patient and control. MAIN OUTCOME MEASURES: Carrier status, clinical presence of thrush, the association between carriage of C. albicans and blood type, secretor status and history of oral infection. RESULTS: In patients with HIV infection and C albicans colonization no correlation was found with blood type or secretor status of blood group antigen in the saliva. The frequency of oral carriage of yeast was greater in patients infected with HIV than in controls, but the difference was not significant for asymptomatic subjects with a CD4+ lymphocyte count greater than 500/microL. Persistent carriage of yeast and development of clinical thrush were associated with lower CD4+ counts. Clinical thrush developed only in patients with persistent asymptomatic carriage of C. albicans and CD4+ counts less than 500/microL. CONCLUSION: The greater risk of oral colonization with C. albicans in patients with HIV infection partly explains the high prevalence of thrush found in this group.

Adolescent↗
PubMed1996

A comparison of two regimens for the treatment of Mycobacterium avium complex bacteremia in AIDS: rifabutin, ethambutol, and clarithromycin versus rifampin, ethambutol, clofazimine, and ciprofloxacin. Canadian HIV Trials Network Protocol 010 Study Group.

BACKGROUND: Bacteremia with the Mycobacterium avium complex is common in patients with the acquired immunodeficiency syndrome (AIDS), but the most effective treatment for this infection remains unclear. METHODS: We randomly assigned 229 patients with AIDS and M. avium complex bacteremia to receive either rifampin (600 mg daily), ethambutol (approximately 15 mg per kilogram of body weight daily), clofazimine (100 mg daily), and ciprofloxacin (750 mg twice daily) (the four-drug group) or rifabutin (600 mg daily), ethambutol (as above), and clarithromycin (1000 mg twice daily) (the three-drug group). In the three-drug group the dose of rifabutin was reduced by half after 125 patients were randomized, because 24 of 63 patients had uveitis. RESULTS: Among 187 patients who could be evaluated, blood cultures became negative more often in the three-drug group than in the four-drug group (69 percent vs. 29 percent, P<0.001). Among patients treated for at least four weeks, the bacteremia resolved more frequently in the three-drug group (78 percent vs. 40 percent, P<0.001). In the three-drug group, bacteremia resolved more often with the 600-mg dose of rifabutin than with the 300-mg dose (P=0.025), but the latter regimen was more effective than the four-drug regimen (P<0.05). The median survival was 8.6 months in the three-drug group and 5.2 months in the four-drug group (P = 0.001). The median Karnofsky performance score was higher in the three-drug group than in the four-drug group from week 2 to week 16 (P<0.05). Mild uveitis developed in 3 of the 53 patients receiving the 300-mg dose of rifabutin, an incidence about one quarter that observed with the 600-mg dose (P<0.001). CONCLUSIONS: In patients with AIDS and M. avium complex bacteremia, treatment with the three-drug regimen of rifabutin, ethambutol, and clarithromycin leads to resolution of the bacteremia more frequently and more rapidly than treatment with rifampin, ethambutol, clofazimine, and ciprofloxacin, and survival rates are better.

AIDS-Related Opportunistic Infections↗
PubMed1996

Clinical and cost considerations in the pharmacotherapy of vulvovaginal candidiasis.

Vulvovaginal candidiasis (VVC) is a frequent cause of morbidity in women of reproductive age. Most women will experience 1 or 2 episodes in their lifetime, but a smaller population develop chronic recurrent disease. There are few data on cost or pharmacoeconomic considerations in the management of this condition. The disease does not usually result in long term disability, loss of employment or death, but could affect a woman's work performance through irritability, frustration and unhappiness. This review attempts to estimate the least costly programme or regimen (as the efficacy of different regimens is similar) that would be applicable to patients, third-party payers and society. Nonprescription or over-the-counter (OTC) antifungal preparations could have an impact on overall cost in the management of VVC. In the management of infrequent acute VVC, an OTC preparation would be least costly to the healthcare system (provided that the diagnosis was correct). The strategies used to control symptoms in patients with chronic recurrent VVC should be based on the frequency of recurrent episodes. For patients with less than 12 episodes a year, empirical self-treatment at the onset of symptoms with an OTC agent (e.g. intravaginal clotrimazole 500mg) is less costly and preferable to patients than monthly prophylaxis. Patients with a greater frequency of recurrences may benefit from monthly, daily or twice weekly prophylaxis. At present, for very frequent recurrences, intravaginal clotrimazole 200mg twice weekly appears to be as effective as daily oral ketoconazole, and may be safer and less costly. However, because of the lack of prospective controlled studies, most of these recommendations are based on hypothetical reasonings. Furthermore, the disadvantages of OTC antifungals include the potential for overuse and inappropriate use, possibly resulting in the delayed diagnosis and treatment of other conditions. On balance, OTC preparations may provide patients with faster and more economical care, and improve healthcare delivery.

Antifungal Agents↗
PubMed1995

The natural history of progressive multifocal leukoencephalopathy in patients with AIDS. Canadian PML Study Group.

Progressive multifocal leukoencephalopathy (PML) is usually a fatal neurological disease. The natural history of PML in patients with human immunodeficiency virus infection was analyzed. The correlations between CD4+ lymphocyte count, previous diagnosis of AIDS, treatment with cytarabine, and survival time are reported for 28 individuals for whom the diagnosis of PML was confirmed by histopathologic examination. For 16 patients (57%), PML was the AIDS-defining illness. For these 16 patients, the mean (+/- SD) survival time after presentation was 7.5 +/- 7.6 months (range, 1-31 months), whereas that for the 12 patients (43%) for whom AIDS was previously diagnosed was 3.2 +/- 2.8 months (range, 1-11 months) (P = .01). The overall mean (+/- SD) CD4+ cell count was 85 +/- 82/mm3 (range, 12-349/mm3). The mean (+/- SD) survival time for patients with CD4+ cell counts of > or = 90/mm3 at the time of presentation was 9.4 +/- 8.7 months, while that for patients with CD4+ cell counts of < 90/mm3 at the time of presentation was 3.6 +/- 1.8 months (P = .03). The nine patients did not benefit from treatment with cytarabine.

Acquired Immunodeficiency Syndrome↗
PubMed1995

The value of a single amphotericin B bladder washout in candiduria.

The efficacy of single amphotericin B bladder washout was assessed, and the source of infection was sought, in 47 patients with 62 separate episodes of candiduria. After a single bladder washout, 44 of 62 (71%) candiduria episodes cleared and none of these patients had evidence of invasive disease or kidney infection. Ten (56%) of 18 patients with persistent candiduria had no evidence of invasive disease or kidney infection at autopsy or clinically. The sensitivity of a positive urine culture for Candida spp. after a single amphotericin B bladder washout in predicting kidney infection or invasive candidiasis was 100% (CI = 63-100%); but the specificity was only 81% (CI = 47-100%) and the positive predictive value only 44%.

Administration, Intravesical↗
PubMed1995

Pharmacokinetics of trimethoprim-sulfamethoxazole in critically ill and non-critically ill AIDS patients.

Current dosage regimens of trimethoprim-sulfamethoxazole used to treat Pneumocystis carinii pneumonia in AIDS patients have been based on data from healthy subjects or patients without AIDS. The clearance and absorption characteristics of the drugs may potentially be different between patients with and without AIDS. This study was conducted to assess the pharmacokinetics of trimethoprim-sulfamethoxazole in critically ill and non-critically ill AIDS patients treated for P. carinii pneumonia. Patients received trimethoprim at 15 mg/kg of body weight and sulfamethoxazole at 75 mg/kg of body weight daily intravenously in three to four divided doses and were switched to the oral route when the regimen was tolerated. Serum samples for determination of drug concentrations were obtained over 12 h after intravenous and oral dosing. The pharmacokinetics of trimethoprim and sulfamethoxazole were compared in eight critically ill versus nine non-critically ill male patients and were as follows, respectively: clearance, 1.88 +/- 0.44 versus 1.73 +/- 0.64 ml/min/kg for trimethoprim and 0.40 +/- 0.12 versus 0.34 +/- 0.11 ml/min/kg for sulfamethoxazole; volume of distribution, 1.6 +/- 0.5 versus 1.5 +/- 0.5 liters/kg for trimethoprim and 0.5 +/- 0.3 versus 0.4 +/- 0.1 liters/kg for sulfamethoxazole; and half-life, 10.9 +/- 7.4 versus 11.3 +/- 4.0 h for trimethoprim, and 15.5 +/- 9.5 versus 14.3 +/- 4.7 h for sulfamethoxazole. No significant differences (P > 0.05) were observed between patient groups, although there was wide intersubject variability. Absorption appeared to be similar between the critically ill and non-critically patients: bioavailability was 97.5% +/- 22.4% versus 101.8% +/- 22.7% for trimethoprim and 86.2% +/- 17.9% versus 99.1% +/- 20.5% for sulfamethoxazole, respectively. Because of the similar pharmacokinetics of trimethoprim-sulfamethoxazole in critically ill and non-critically ill AIDS patients, the two groups of patients may receive similar dosages. Dosage adjustment does not appear to be required when switching from the intravenous to the oral route.

AIDS-Related Opportunistic Infections↗
PubMed1995

Effects of an acidic beverage (Coca-Cola) on absorption of ketoconazole.

Absorption of ketoconazole is impaired in patients with achlorhydria. The purpose of this study was to determine the effectiveness of a palatable acidic beverage (Coca-Cola Classic, pH 2.5) in improving the absorption of ketoconazole in the presence of drug-induced achlorhydria. A prospective, randomized, three-way crossover design with a 1-week wash-out period between each treatment was employed. Nine healthy nonsmoking, nonobese volunteers between 22 and 41 years old were studied. Each subject was randomized to receive three treatments: (A) ketoconazole 200-mg tablet with water (control), (B) omeprazole (60 mg) followed by ketoconazole (200 mg) taken with water, and (C) omeprazole (60 mg) followed by ketoconazole (200 mg) taken with 240 ml of Coca-Cola Classic. The pH values of gastric aspirates were checked after omeprazole was administered to confirm attainment of a pH of > 6. Multiple serum samples were obtained for measurements of ketoconazole concentrations by high-pressure liquid chromatography. The mean area under the ketoconazole concentration-time curve from zero to infinity for the control treatment (17.9 +/- 13.1 mg.h/liter) was significantly greater than that for treatment B (3.5 +/- 5.1 mg.h/liter; 16.6% +/- 15.0% of control). The mean peak concentration was highest for the control treatment (4.1 +/- 1.9 micrograms/ml), for which the mean peak concentration showed a significant increase over that for treatment B. The absorption of ketoconazole was reduced in the presence of omeprazole-induced achlorhydria. However, drug absorption was significantly increased, to approximately 65% of the mean for the control treatment, when the drug was taken with an acidic beverage, such as Coca-Cola.

Achlorhydria↗
PubMed1995

Diagnostic value of detecting JC virus DNA in cerebrospinal fluid of patients with progressive multifocal leukoencephalopathy.

JC virus DNA was detected by PCR in the cerebrospinal fluid of 17 of 23 (73.9%) patients with confirmed cases of progressive multifocal leukoencephalopathy and 2 of 48 (4.2%) controls without progressive multifocal leukoencephalopathy. The sensitivity and specificity of this PCR were 74 and 95.8%, respectively, while the positive and negative predictive values were 89.5 and 88.5%, respectively.

DNA, Viral↗
PubMed1995

Clarithromycin versus cefaclor in lower respiratory tract infections. The Canadian Bronchitis Study Group.

A randomized study was done to compare the efficacy of clarithromycin 250 mg or 500 mg b.i.d., vs. cefaclor 250 mg or 500 mg t.i.d. for 7-14 d in 197 evaluable patients with lower respiratory tract infection. Ninety-five patients received clarithromycin, 88 with acute bronchitis or exacerbation of chronic bronchitis, and 7 with pneumonia. One hundred and two patients received cefaclor, 86 with bronchitis and 16 with pneumonia. Ten patients (10.5%) in the clarithromycin group did not complete the trial, 5 (5.3%) because of adverse event, and 3 (3.2%) because of clinical failure. Similarly, 11 patients (10.8%) did not complete cefaclor, 2 (2%) because of adverse event, and 7 (6.9%) because of clinical failure. Clinical cure or improvement was observed in 90 (94.7%) of patients on clarithromycin vs. 92 (90.2%) on cefaclor, p = 0.66. Bacteriologic cure was seen in 26/36 patients (72.2%) on clarithromycin vs. 28/40 patients (70%) on cefaclor, p = 0.28. Clarithromycin is just as effective as cefaclor for lower respiratory tract infections and is well tolerated.

Bronchitis↗
PubMed1994

Alcoholism and rapid progression to AIDS after seroconversion.

Rapid progression of infection with human immunodeficiency virus type 1 (HIV-1) to AIDS after seroconversion is rare; it has been associated with coinfection by cytomegalovirus or human T lymphotrophic virus type I. We describe an alcoholic patient whose condition progressed to AIDS 3 months after HIV-1 seroconversion occurred. Culture of peripheral blood mononuclear cells yielded a syncytium-inducing variant of HIV-1. T lymphocytes showed no spontaneous cytotoxic activity against HIV-infected cells, nor could such activity be demonstrated following stimulation with HIV-1 antigen in the presence of recombinant interleukin-2. We hypothesize that our patient's accelerated course was due to alcohol abuse, which may have suppressed T cell function and stimulated HIV replication.

Acquired Immunodeficiency Syndrome↗
PubMed1994

The value of prophylactic (monthly) clotrimazole versus empiric self-treatment in recurrent vaginal candidiasis.

OBJECTIVE: To determine the comparative efficacy and cost benefit of prophylactic monthly (perimenstrual) clotrimazole, versus empiric self-treatment with the same agent at the onset of symptoms in recurrent vulvovaginal candidiasis. DESIGN: Prospective, randomised, open cross-over study of women with proven recurrent vulvovaginal candidiasis. Clinical and microbiological assessments were done every two months for 12 months. SETTING: Women's Clinic of a University Teaching Hospital. SUBJECTS: Twenty-three otherwise healthy, non-pregnant women with greater than four proven episodes of candida vaginitis in the last year were enrolled into the study. INTERVENTION: Patients were randomised to receive: (1) a single dose of prophylactic clotrimazole 500 mg ovule just before or on the last day of the menses each month for 6 months; (2) or a single dose of clotrimazole 500 mg ovule empirically at the onset of symptoms for 6 months. After the first 6 months patients were crossed-over to the opposite regimen. MAIN OUTCOME MEASURES: Symptoms of recurrent vulvovaginitis during each period, and number of clotrimazole ovules used for each 6 month period. The personal preference of the patients for the two different regimens were assessed at the end of study. RESULTS: During the prophylactic 6 months period of the study, 23 patients had 50 episodes of symptomatic vaginitis (mean 2.2 episodes per patient), versus 86 episodes (mean 3.7 episodes/patient) during the empiric self-treatment 6 months period (P = 0.05). However, during the prophylactic period a total of 168 clotrimazole ovules were used (mean 7.3 per patient), versus 84 ovules (mean 3.6 per patient) during the empiric self-treatment period, p < 0.001. The personal preference of the patients for the type of regimen employed were 17 (73.9%) in favour of the empirical treatment, versus 4 (17.4%) in favour of the prophylactic treatment and 2 (8.7%) no personal preference, p < 0.01. CONCLUSION: Empiric self-treatment is more cost-effective and preferable to patients than cyclical monthly prophylactic use of 500 mg clotrimazole vaginal ovules.

Adolescent↗
PubMed1994

The rectal carriage of yeast in patients with vaginal candidiasis.

Reinfection from the lower gastrointestinal tract is a possible source of recurrent vulvo-vaginal candidiasis. A prospective study to assess the prevalence of yeast carriage in various orifices (including the rectum) in controls and patients, and the relationship to acute vaginitis, was conducted. Cultures for yeast were obtained from the mouth, rectum, vulva, and vagina every 1-2 months for 1 y from the patients. The prevalence of yeast carriage in healthy controls was 3/37 (8.1%) from the vulva, vagina, and rectum, and 4/37 (10.8%) from the mouth. In patients, yeast carriage during episodes of vaginitis was: from the vagina, 190/193 (98.4%); from the vulva, 107/193 (55.4%); from the rectum, 93/193 (48.2%); and from the mouth, 52/193 (26.9%). During visits without vaginitis, yeast carriage was lower: in the rectum, 59/587 (10.1%); in the vulva, 53/459 (11.6%); in the vagina, 77/587 (13.1%); and in the mouth, 89/587 (15.2%). Yeast in the lower bowel during symptomatic vaginitis is higher (p = 0.0001) than in controls, but not significantly greater during asymptomatic periods. Recurrence of Candida vaginitis is not dependent on yeast reservoir in the lower gut between symptomatic episodes.

Administration, Intravaginal↗
PubMed1993

Tularemia from a cat bite: case report and review of feline-associated tularemia.

We report the case of a 63-year-old man who developed ulceroglandular tularemia complicated by pneumonia following a cat bite. A review of the literature revealed 51 cases of cat-related tularemia reported since 1928. Details of 15 cases (including the present case) were available and analyzed. If, following feline contact, patients develop pneumonia or if patients with skin and soft-tissue infection fail to respond to therapy with penicillin, physicians should be alerted to the possibility of tularemia. A greater awareness of this complication following a cat bite or cat scratch is important for recognizing this uncommon infection.

Animals↗
PubMed1993

Lack of in vitro resistance of Candida albicans to ketoconazole, itraconazole and clotrimazole in women treated for recurrent vaginal candidiasis.

OBJECTIVE: To determine whether in vitro resistance of Candida albicans to the imidazoles (ketoconazole, clotrimazole and itraconazole) is associated with recurrence of candida vaginitis. DESIGN: Candida isolates were collected before, during and after treatment from women with recurrent vaginal candidiasis (> or = 4 episodes/year), randomised into two prospective studies: (1) 56 women treated with ketoconazole 400 mg/daily for 7 days; (2) 44 women randomised to receive itraconazole 200 mg orally, or clotrimazole 200 mg intravaginally, twice weekly for six months. SETTING: Women's Candida Clinic at St. Michael's Hospital, a University of Toronto teaching Hospital, Toronto, Ontario, Canada. MAIN OUTCOME, MEASURES: Isolates of yeasts recovered pre and post treatment were tested for significant changes in 50% inhibitory concentration (IC50). Resistance was defined as a greater than fourfold increase in baseline IC50 of post treatment isolates compared with pretreatment isolates. RESULTS: Over 250 strains of C albicans were tested and none showed development of resistance to any of the agents. CONCLUSION: Recurrence of vaginal candidiasis is not related to the development of drug resistance.

Adolescent↗
PubMed1993

Infection of arterio-venous fistulas created for chronic haemodialysis.

One of the complications of chronic haemodialysis is infection at the venous access site. A retrospective chart review (1985-1990) was done on patients requiring venoaccess for haemodialysis. 197 patients had 254 arterio-venous (A-V) fistulas created. 40 patients had 71 prosthetic implants and 157 patients had 183 autogenous fistulas created. 16 (22%) prosthetic grafts were infected versus 8 (4.3%) autogenous fistulas (p < 0.0001). Bacteraemia was present in 9/16 (56%) infected prosthetic grafts and 4/8 (50%) infected autogenous fistulas. Seven (43.8%) of the prosthetic grafts required removal; 6 (37.5%) were cured with drainage, irrigation and antibiotics, and 3 (18.8%) with antibiotics alone. One (12.5%) of the autogenous fistulas was removed, 4 (50%) required revision and 3 (37.5%) were treated with antibiotics alone. Whenever possible, A-V fistulas should be created in the arms with an autogenous graft as infections are less and easier to treat.

Adolescent↗
PubMed1993

Medication use patterns in HIV-positive patients.

Patients with HIV infection or AIDS often receive several medications for treatment or prevention of their primary disease and/or associated complications. The objective of this study was to document patterns of drug use in an HIV-positive, outpatient population. Data were collected via one-on-one interviews with 26 HIV-positive patients; prescription and non-prescription drug use, adverse drug reactions and drug allergies were recorded. Anti-retroviral therapy was received by over 90 % of the patients. Over 90% of patients were on anti-infective agents, commonly cotrimoxazole or dapsone, while 27% received acyclovir. At least 70% of patients used three or more prescription medications concurrently. Every patient reported self-medicating with at least one over-the-counter (OTC) product and over half used three or more OTC products concurrently. Adverse reactions, mainly attributable to zidovudine, were reported by over 80% of patients. Non-compliance was a common drug-related issue; over 70% of patients omitted drug doses. In conclusion, the use of multiple medications in the ambulatory HIV-positive patients presents the health care team with potential drug-related problems that may ultimately affect the efficacy and toxicity of therapy. Thus pharmacists may play an active role in the provision of direct care to these patients.

Adult↗