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Biomedical subjects

K McCoy

Publications and source records attributed to K McCoy.

At least 37 records · Page 2Linked to original sources

Pharmacokinetics and safety of tobramycin after once-daily administration in patients with cystic fibrosis.

STUDY OBJECTIVE: Tobramycin is commonly used to treat respiratory tract infections in patients with cystic fibrosis. We designed a study to determine the pharmacokinetics and safety of once-daily dosing of tobramycin in this population. DESIGN: Multiple blood samples were collected from each patient, and serum concentrations of tobramycin were determined by a fluorescence polarization immunoassay. Blood urea nitrogen and serum creatinine levels were measured every 2 to 3 days, and audiometric evaluations were performed at the start and end of therapy. MEASUREMENTS AND RESULTS: Eighteen patients (mean age, 24.6 years) received tobramycin at doses of 7 to 15 mg/kg/d as a single-dose infusion over 20 min. The maximum serum concentration of tobramycin ranged from 40.1 to 64.6 mg/L. A mean dose of 11.9+/-1.9 mg/kg was needed to obtain a theoretical mean peak serum concentration of 42.4+/-4.5 mg/L. The mean total body clearance, apparent volume of distribution, and elimination half-life was 1.7+/-0.4 mL/min/kg, 0.27+/-0.06 L/kg, and 1.8+/-0.3 h, respectively. The period of time that the serum concentration exceeded eight times the theoretical minimum inhibitory concentration of 1 mg/L ranged from 2.1 to 4.4 h, which was nearly five times longer compared with the use of divided daily doses in the same patients during previous hospitalizations. No nephrotoxicity, ototoxicity, or adverse effects occurred in any patient. CONCLUSION: Based on our data, tobramycin may be used safely in once-daily doses to treat exacerbations of respiratory tract infections in patients with cystic fibrosis.

Adolescent↗

Protective immunity to nematode infection is induced by CTLA-4 blockade.

The recent observation that neutralization or genetic deletion of the T lymphocyte receptor CTLA-4 allows enhanced T cell reactivity offers new opportunities for immunotherapy against infectious agents. We used a neutralizing antibody to block CTLA-4 interaction with its ligands CD80 and CD86 during infection of mice with the nematode, Nippostrongylus brasiliensis. CTLA-4 blockade greatly enhanced and accelerated the T cell immune response to N. brasiliensis, resulting in a profound reduction in adult worm numbers and early termination of parasite egg production. The ability of CTLA-4 blockade to accelerate primary immune responses to a protective level during an acute infection indicates its potential as an immunotherapeutic tool for dealing with infectious agents.

Abatacept↗

Can the histologic changes of cystic fibrosis-associated hepatobiliary disease be predicted by clinical criteria?

BACKGROUND: Correlation between clinical parameters and histology changes in cystic fibrosis liver disease has not been documented. The purpose of this study was to determine the histologic spectrum of cystic fibrosis liver disease and the degree to which a clinical scoring system can identify subjects with significant histologic abnormalities. METHODS: We reviewed the predictive value of physical examination, biochemical parameters, and a clinical liver score, incorporating physical examination and biochemical parameters, in predicting significant abnormalities of liver histology in 43 cystic fibrosis patients who underwent hepatic biopsy. Biopsies were scored by two masked pathologists for fibrosis, inflammation, inspissation, fatty infiltration, and congestion. RESULTS: Significant histologic disease was present in 56% of patients despite little biochemical or physical examination evidence of disease. No single parameter used in the scoring system predicted the type or degree of the liver disease. The clinical liver score had a sensitivity of 85% and a specificity of 82% in predicting significant histologic changes, yet it was unable to predict the specific lesion. CONCLUSIONS: Significant histologic liver disease is common in cystic fibrosis, although the exact nature of the lesion cannot be predicted without liver biopsy. A clinical liver score that was developed for this may be useful in determining which patients require more definitive evaluation.

Adolescent↗

Aerosolized recombinant human DNase in hospitalized cystic fibrosis patients with acute pulmonary exacerbations.

The goal of this study was to evaluate the safety and efficacy of recombinant human DNase (rhDNase) in hospitalized patients with cystic fibrosis (CF) experiencing acute pulmonary exacerbations. Eighty patients with documented CF were enrolled at 11 CF centers when admitted for antibiotic therapy. Patients were at least 5 yr old with a forced vital capacity (FVC) > or = 35% of predicted and an oxygen saturation > or = 90% on a fraction of inspired oxygen (FIO2) < 0.5. Patients were randomized to receive rhDNase 2.5 mg in 2.5 ml excipient twice a day (n = 43) or 2.5 ml excipient alone twice daily (n = 37) along with conventional treatment for exacerbations. Administration of rhDNase was not associated with acute adverse events or deaths, and no patients experienced allergic or anaphylactic reactions. Although forced expiratory volume in one second (FEV1) and FVC improved in both treatment groups during the double-blind period, there were no statistically significant differences in the mean change from baseline in FEV1 or FVC between the two groups. rhDNase therapy is safe and well tolerated in CF patients with acute exacerbations requiring hospitalization, but the study did not demonstrate a statistically significant therapeutic effect of rhDNase when added to a regimen of antibiotics and chest physical therapy.

Acute Disease↗

Effects of 12-week administration of dornase alfa in patients with advanced cystic fibrosis lung disease. Pulmozyme Study Group.

STUDY OBJECTIVE: The 12-week efficacy and safety of aerosolized recombinant human DNase (dornase alfa) were evaluated in previously untreated patients with cystic fibrosis (CF) with advanced lung disease. DESIGN: In this multicenter, double-blind, placebo-controlled study, CF patients with advanced lung disease were randomized to receive either dornase alfa or placebo once a day for 12 weeks. PATIENTS: A total of 320 patients in clinically stable condition with documented CF and an FVC less than 40% of predicted were recruited from 65 CF Foundation care centers in the United States. The dornase alfa and placebo groups were comparable with respect to age (range, 7 to 57 years), height, and weight. Male subjects outnumbered female subjects (55% vs 45%) and few subjects were younger than 17 years of age (15%). The percentages of predicted FEV1 and FVC were significantly lower in the dornase alfa group at baseline (p < or = 0.05). INTERVENTIONS: Patients were randomly assigned to receive either 2.5 mg dornase alfa once daily (n = 158) or placebo once daily (n = 162). All patients continued to receive standard medications and treatments administered for CF. MEASUREMENTS AND RESULTS: Dornase alfa improved the mean percent change in FEV1 from baseline by 9.4% compared with 2.1% for placebo (p < 0.001). The actively treated group showed a 12.4% improvement in FVC compared with 7.3% for placebo (p < 0.01). There were no differences between the treatment groups in dyspnea score number of days receiving i.v. antibiotics, or length of hospital stay; the overall incidence of adverse events was comparable between treatment groups. Fifteen patients died: 9 in the dornase alfa group and 6 in the placebo group; no differentiating clinical characteristics were demonstrated. CONCLUSIONS: Pulmonary function as measured by FEV1 and FVC improved significantly in the dornase alfa-treated patients. Dornase alfa was found to be safe and well tolerated over the 12-week study period.

Adolescent↗

Diagnostic agreement in the classification of headache using Ad Hoc Committee and IHS criteria.

This study examined the level of agreement between raters in the diagnosis of headache using the Ad Hoc Committee (AHC) on the Classification of Headache and the Headache Classification Committee of the International Headache Society (IHS) classification criteria. In addition, differences in classification of headache between the AHC and IHS classification systems were considered. Analyses indicated that both the AHC and IHS classification systems were adequate in allowing clinicians to reach 100% agreement in diagnosis of headache cases (N = 36). Additionally, there was 91.7% diagnostic agreement between the two sets of criteria as applied by the raters. Differences in diagnostic classification between the two sets of criteria were believed to be the result of IHS exclusionary criteria in the classification of Tension-type headache.

Adult↗