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Biomedical subjects

C T Le

Publications and source records attributed to C T Le.

At least 73 records · Page 4Linked to original sources
PubMed1989

Bronchodilation from intravenous theophylline in patients with cystic fibrosis: results of a blinded placebo-controlled crossover clinical trial.

Most patients with cystic fibrosis (CF) eventually develop chronic obstructive pulmonary disease and theoretically could benefit from theophylline therapy. The purpose of this study was to investigate the pharmacologic response to intravenous theophylline by pulmonary function tests (PFT) and the theophylline pharmacokinetics in patients with CF. A randomized, double-blind, placebo-controlled, crossover trial was conducted in 10 ambulant patients with CF (5 females, 5 males), aged 11 to 21 years. Each patient received an intravenous dose of theophylline and normal saline over 1/2 hour on consecutive days. Spirometry and whole-body plethysmography were performed at baseline, 1, 3, 5, and 7 h after the theophylline dose, and 10 blood samples were collected over 9 h on both study days. The percent change of PFT from the baseline was recorded. Analysis of variance for balanced two-period crossover design was used to evaluate the effectiveness of theophylline therapy. The serum concentration (Conc.) vs. time data were fitted using nonlinear least-squares regression analysis. The theophylline dose administered was 7.9 +/- 0.4 (mean +/- SD) mg/kg, which produced a maximal Conc. (Cmax) of 14.6 +/- 2.7 microgram/ml. The half-life (T1/2), volume of distribution (Vd), and total body clearance (TBC) were 4.9 +/- 1.9 h, 537 +/- 124 mL/kg, and 80 +/- 16 ml/h/kg, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Experimental animal models for studying antimicrobial pharmacokinetics in otitis media.

Antimicrobial treatment of otitis media, especially drug dosing considerations, is largely empiric, with few reported pharmacologic studies of drug distribution into the middle ear. A chinchilla animal model of serous and purulent otitis media has been used for some time to investigate mechanisms of disease pathogenesis. This model was adapted to investigate the penetration of amoxicillin, trimethoprim, and sulfamethoxazole into middle ear effusion. Purulent otitis media was produced by direct middle ear inoculation with type 7F Streptococcus pneumoniae. Serous otitis media was produced by eustachian tube obstruction using silastic sponge or Coeflex cement, but the Coeflex caused an undesirable local inflammatory response. The three antibiotics were administered to chinchillas with serous and purulent middle ear effusion. Plasma and ear fluid drug concentrations were measured by liquid chromatography and demonstrated the value of this model in assessing antibiotic penetration.

Amoxicillin↗
PubMed1988

Randomization using packaged programs.

The problem of implementation of a randomization in controlled clinical trials is briefly discussed. A computer procedure is proposed and illustrated with simple programs using BMDP, SAS, and SPSS.

Clinical Trials as Topic↗
PubMed1988

Determining risk for chronic otitis media with effusion.

Chronic otitis media with effusion (OME) has been observed in 10 to 20% of children following acute, symptomatic otitis media. To determine factors that place children at increased risk of chronic OME, we conducted a 6-week prospective study of 386 children who had 3 or more recent episodes of otitis media and who had middle ear effusion present for at least 2 weeks. Of these children 23% developed chronic OME (i.e. effusion lasting 8 continuous weeks or more), and 26% developed chronic OME complicated by acute, symptomatic otitis media. Predictors for chronic OME were (1) bilateral OME, (2) duration of effusion for greater than 2 weeks at enrollment and (3) day care attendance. Children with these 3 factors had twice the risk of developing chronic OME as children lacking all 3 factors. These risk factors can be used to target children for early, aggressive OME therapy.

Child↗
PubMed1988

Testing for linear trends in proportions using correlated otolaryngology or ophthalmology data.

This paper is concerned with the issue of testing for trend with correlated binary data. We consider the problem where one has either one or two ears (or eyes) available for analysis at baseline and one wishes to look at changes over time in a dichotomous outcome taking into account the correlation between responses from two ears. A reparameterization of Rosner's (1982, Biometrics 38, 105-114) correlated binary data model is presented and applied to a test for trend where the stratifying variable is age (or any other subject-specific variable). Observed and expected values are calculated for the trend statistic separately for both unilateral and bilateral cases and are then summed to obtain an overall summary statistic. The proposed method is illustrated by a reanalysis of data presented in a published study of the efficacy of antibiotics for the treatment of otitis media.

Amoxicillin↗
PubMed1987

Thickness of the human round window membrane in different forms of otitis media.

The thickness and morphologic characteristics of the round window membrane were evaluated in temporal bones from normal subjects as well as those with serous otitis media, purulent otitis media, and chronic otitis media. Temporal bones were studied in chronological order in six age ranges to determine the possibility of age-related differences. No significant difference in the mean thickness of the round window membrane was observed in terms of age groups in normal temporal bones or temporal bones from patients with otitis media; however, a significant difference in the mean thickness was observed in the various forms of otitis media compared with the normal round window membrane in all age groups. The membrane was thickest in patients with chronic otitis media when compared with that in normal subjects or those with serous or purulent otitis media. The epithelial layer (including the subepithelial space) and the fibrous layer were measured individually to determine in which layer the change in mean thickness occurred. These measurements showed an involvement of all layers of the round window membrane in those groups with otitis media, with maximal involvement of the combined epithelial layer and subepithelial space.

Adolescent↗
PubMed1987

Microbiological evaluation of wet and dry floor sanitization systems in hospital patient rooms.

A new system for sanitizing floors in hospital patient rooms has been developed. The method consists of dry dusting with a cotton-blend, chemically treated (10% by dry mop weight) dust mop. This method was compared with a conventional cleaning protocol consisting of an initial predusting with the same nongermicidal chemical (3% by dry mop weight) followed by wet mopping with a fresh solution of a quaternary ammonium disinfectant-detergent. Each of six rooms was sampled by using RODAC plates (Becton Dickinson Labware, Oxnard, Calif.) on 10 consecutive days for each of the two methods. The study was initially performed during the summer and then repeated during the winter. Results imply that there is no significant difference between the new dry method (81.9% CFU reduction) and the conventional method (83.1% CFU reduction). Furthermore, the initial dry dusting step in the conventional method accounted for virtually all of the reduction by that method. Thus, wet mopping with a germicidal chemical produced no additional significant reduction of natural microbial populations on environmental surfaces beyond that achieved by dry dusting with dust-suppressant chemicals.

Analysis of Variance↗
PubMed1986

Decline of vaccine-induced antipneumococcal antibody in children with nephrotic syndrome.

Twenty-five children with steroid-responsive idiopathic nephrotic syndrome were studied for persistence of antipneumococcal capsular polysaccharide antibody during relapse of their disease and at 1, 6, and 12 months after vaccination with the 14-valent pneumococcal vaccine. Nonrelapsers (group I) were compared to those who had at least one relapse but whose sera were obtained during remission (group II). Group II had a more rapid decline in total anticapsular antibody per month than group I (5.3% v 2.4%). Analysis by individual anticapsular types showed that differences between groups approached significance only for type 4 (P = .07). Rates of decline of antibody against pneumococcal capsular polysaccharide varied among types. One year after vaccination, 50% of patients had less than 300 ngAbN/mL against types 4, 6A, 7F, 8, and 19F. Sera obtained from seven patients during relapse had geometric mean antibody concentrations less than 300 ngAbN/mL against those same types; two of these types have been reported to cause disease in vaccinated patients with nephrosis. Decline of antibody against pneumococcal capsular polysaccharide following vaccination varies by capsular type. Type-specific analysis should be used when monitoring serum antibody levels in these patients after vaccination.

Adolescent↗
PubMed1985

Evaluation of nongermicidal handwashing protocols for removal of transient microbial flora.

A method has been described which can compare the efficacy of different nongermicidal handwashing protocols for removal of transient microbial flora without the necessity of establishing or relying on a previously determined baseline for an individual subject. The wash effluent is collected, and colony counts for the effluent reflect the number removed by the wash protocol. A second standard wash in a handwashing machine is performed, and the test criterion is the percent removed in the test wash based on the sum of total CFU recovered from the two washes. The method was used to compare an 8-s cycle for a newly developed handwashing machine with a conventional 15-s Ivory soap wash. When machine pressure was adequate (42 lb/in2), there was no statistically significant difference in the percent removal of transient flora by the two methods (48.8% from the machine versus 45.1% from the Ivory soap wash). At 32 lb/in2, the Ivory soap wash recovered 60.3%, whereas the machine recovered 45.1%.

Analysis of Variance↗
PubMed1984

Cefaclor v amoxicillin in treatment of acute otitis media.

A randomized clinical trial compared cefaclor and amoxicillin for the treatment of acute otitis media (AOM). Twenty-four (77%) of the 31 examined patients treated with cefaclor and 25 (83%) of the 30 examined patients treated with amoxicillin had resolution of signs and symptoms after completing a ten- to 14-day course of the antibiotic. Patients who had bilateral AOM, serous or mucoid middle ear effusion, Hemophilus influenzae cultured from effusion, or more than five previous otitis media episodes, or who were 3 years of age or younger were more likely to fail treatment. Hemophilus influenzae isolated from effusion were significantly less susceptible to cefaclor than amoxicillin, but none of the 12 treatment failures were caused by antibiotic-resistant infections. Eight (36%) of the 22 patients who recovered after treatment and were reexamined one to three weeks later experienced recurrent AOM. Ear-specific, as well as patient-specific, analyses showed no significant differences between cefaclor and amoxicillin.

Acute Disease↗