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Biomedical subjects

C Knirsch

Publications and source records attributed to C Knirsch.

6 recordsLinked to original sources
PubMed2001

Antibiotic use and risk of ischemic stroke in the elderly.

PURPOSE: To determine whether treating infections with antibiotics that have antichlamydial activity decreases the risk of ischemic stroke in the elderly. SUBJECTS: We analyzed data from 199 553 subjects 65 years and older in a health care claims database who had continuous health and pharmacy coverage for at least 2 years between January 1, 1991, and September 30, 1997. Using proportional hazards models with time-dependent covariates for prior antibiotic prescription and adjusting for cardiovascular risk factors, we determined the associations between antibiotic use and first claim for ischemic stroke (n = 7,335) during the observation period. RESULTS: Rates of stroke (per 1,000 person-years) were 6.64 for macrolides, 9.27 for quinolones, 7.49 for tetracyclines, 6.88 for penicillins, 7.97 for cephalosporins, 8.58 for trimethoprim-sulfamethoxazole, and 7.29 for subjects with no antibiotic claims. The adjusted hazard ratios (HR) were 0.94 (95% confidence interval [CI]: 0.87 to 1.01) for macrolides, 1.04 (95% CI: 0.91 to 1.18) for tetracyclines, 1.02 (95% CI: 0.95 to 1.08) for penicillins, and 1.00 (95% CI: 0.82 to 1.22) for trimethoprim-sulfamethoxazole. Subjects with claims for quinolone antibiotics (HR = 1.17; 95% CI: 1.09 to 1.26) and cephalosporins (HR = 1.09; 95% CI: 1.02 to 1.16) had a slightly higher risk of stroke. CONCLUSION: Exposures to short courses of antibiotics are not associated with lower risk of ischemic stroke in patients aged 65 years and older.

Aged↗
PubMed2000

Discontinuation of Mycobacterium avium complex prophylaxis in patients with antiretroviral therapy-induced increases in CD4+ cell count. A randomized, double-blind, placebo-controlled trial. AIDS Clinical Trials Group 362 Study Team.

BACKGROUND: Patients infected with HIV who experience increases in CD4(+) cell counts are at reduced risk for opportunistic infections. However, the safety of discontinuing prophylaxis against Mycobacterium avium complex has been uncertain. OBJECTIVE: To compare the rate of M. avium complex infection in patients with increased CD4(+) cell counts who receive azithromycin and those receiving placebo. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: 29 university-based clinical centers in the United States. PARTICIPANTS: 643 HIV-1-infected patients with a previous CD4(+) cell count less than 0.05 x 10(9) cells/L and a sustained increase to greater than 0.10 x 10(9) cells/L during antiretroviral therapy. INTERVENTION: Azithromycin, 1200 mg once weekly (n = 321), or matching placebo (n = 322). MEASUREMENTS: Mycobacterium avium complex cultures, CD4(+) cell counts, and clinical evaluations for AIDS-defining illnesses and bacterial infections were done every 8 weeks. Plasma HIV-1 RNA levels were measured at 16-week intervals. RESULTS: During follow-up (median, 16 months), 2 cases of M. avium complex infection were reported among the 321 patients assigned to placebo (incidence rate, 0.5 event per 100 person-years [95% CI, 0.06 to 1.83 events per 100 person-years]) compared with no cases among the 322 patients assigned to azithromycin (CI, 0 to 0.92 events per 100 person-years), resulting in a treatment difference of 0.5 event per 100 person-years (CI, -0.20 to 1.21 events per 100 person-years) for placebo versus azithromycin. Both cases were atypical in that M. avium complex was localized to the vertebral spine. Patients receiving azithromycin were more likely than those receiving placebo to discontinue treatment with the study drug permanently because of adverse events (8% vs. 2%; hazard ratio, 0.24 [CI, 0.10 to 0.57]). CONCLUSIONS: Prophylaxis against Mycobacterium avium complex can safely be withdrawn or withheld in adults with HIV infection who experience increases in CD4(+) cell count while receiving antiretroviral therapy.

AIDS-Related Opportunistic Infections↗
PubMed2000

Collaborative multidisciplinary workshop report: clinical antimicrobial trials for primary and secondary prevention of atherosclerotic cardiovascular disease.

The task assigned to the working group on Clinical Antimicrobial Trials for Primary and/or Secondary Prevention of Atherosclerotic Cardiovascular Disease was to evaluate the need for additional clinical antibiotic trials of a primary or secondary nature for the treatment of atherosclerotic heart disease and to suggest possible designs for future trials. In addition, the working group was to define the role of collaboration in answering research questions.

Anti-Bacterial Agents↗
PubMed1999

Diagnosis of pediatric tuberculosis in the modern era.

BACKGROUND: Correctly diagnosing tuberculosis (TB) in children is critical to provide appropriate treatment and to detect undiagnosed source cases. However, diagnosing TB in children may be difficult. OBJECTIVE: We sought to determine whether Amplicor, a Food and Drug Administration-approved polymerase chain reaction (PCR) assay used to detect Mycobacterium tuberculosis in sputum and computerized tomography (CT) would facilitate the diagnosis of TB in children. We also examined the applicability of the Centers for Disease Control and Prevention clinical case definition for TB. SETTING: A university-affiliated pediatric hospital in New York City. SUBJECTS: From March, 1995, to November, 1997, 27 children < 15 years of age (mean age, 3.9 years) were evaluated for suspected TB. RESULTS: M. tuberculosis was cultured from 5 of 76 (6.6%) gastric aspirate specimens, and PCR detected M. tuberculosis DNA in 3 (4.1%) of these specimens. There was poor correlation between culture and PCR because 6 specimens were discordant. CT scans were diagnostic of mediastinal or hilar adenopathy in 6 children with equivocal or negative chest radiographs and confirmed adenopathy in 8 others. Six children received alternative diagnoses. CONCLUSIONS: We conclude that the commercially available PCR technology had very limited utility in detecting M. tuberculosis from gastric aspirates, but CT scans were useful in assessing pediatric patients with suspected TB.

Adolescent↗
PubMed1999

Automating a severity score guideline for community-acquired pneumonia employing medical language processing of discharge summaries.

Obtaining encoded variables is often a key obstacle to automating clinical guidelines. Frequently the pertinent information occurs as text in patient reports, but text is inadequate for the task. This paper describes a retrospective study that automates determination of severity classes for patients with community-acquired pneumonia (i.e. classifies patients into risk classes 1-5), a common and costly clinical problem. Most of the variables for the automated application were obtained by writing queries based on output generated by MedLEE1, a natural language processor that encodes clinical information in text. Comorbidities, vital signs, and symptoms from discharge summaries as well as information from chest x-ray reports were used. The results were very good because when compared with a reference standard obtained manually by an independent expert, the automated application demonstrated an accuracy, sensitivity, and specificity of 93%, 92%, and 93% respectively for processing discharge summaries, and 96%, 87%, and 98% respectively for chest x-rays. The accuracy for vital sign values was 85%, and the accuracy for determining the exact risk class was 80%. The remaining 20% that did not match exactly differed by only one class.

Community-Acquired Infections↗