Benefits of a school-based asthma treatment program in the absence of secondhand smoke exposure: results of a randomized clinical trial

BACKGROUND: Daily maintenance medications are recommended for all children with mild persistent to severe persistent asthma; however, poor adherence to these medications is common. OBJECTIVE: To evaluate the impact of school-based provision of inhaled corticosteroids on asthma severity among urban children with mild persistent to severe persistent asthma. DESIGN: Children aged 3 to 7 years with mild persistent to severe persistent asthma were identified at the start of the 2000-2001 and 2001-2002 school years in Rochester. Children were assigned randomly to a school-based care group (daily inhaled corticosteroids provided through the school) or a usual-care group (inhaled corticosteroids not given through school). MAIN OUTCOME MEASURE: Improvement in parent-reported symptom-free days. RESULTS: Of 242 eligible children, 184 were enrolled from 54 urban schools. Data for 180 children were available. Parents of children in the school-based care group had a greater improvement in quality of life compared with parents of children in the usual-care group (change score, 0.63 vs 0.24; P =.047); also, children in the school-based care group vs the usual-care group missed less school because of asthma (mean total days missed, 6.8 vs 8.8; P =.047) and experienced more symptom-free days during the early winter months (mean days per 2-week period, 9.2 vs 7.3; P =.02). A post hoc analysis revealed that all significant findings were produced by differences among children who were not exposed to secondhand smoke. Furthermore, among children not exposed to smoke, those in the school-based care group vs the usual-care group had more symptom-free days overall (11.5 vs 10.5; P =.046), had fewer days needing rescue medications (1.6 vs 2.3; P =.03), and were less likely to have had 3 or more acute visits for asthma (6 [13%] of 47 children vs 17 [31%] of 54 children; P =.03). CONCLUSIONS: School-based provision of inhaled corticosteroids significantly improved symptoms, quality of life, and absenteeism among urban children with mild persistent to severe persistent asthma. This effect was seen only among children not exposed to secondhand smoke.     

Cell division rates of primary human precursor B cells in culture reflect in vivo rates

Bone marrow stroma-based cultures provide a powerful model for studying cell division and apoptosis of primary human precursor B cells. Studies using this model are elucidating the mechanisms by which stromal cells inhibit apoptosis of cultured normal precursor B cells and have demonstrated that the apoptotic rate of cultured leukemic precursor B cells can predict clinical outcome in acute lymphoblastic leukemia. In contrast to apoptosis, cell division in this model has not been well characterized. In this study, we quantified the rates of cell division in cultured primary human normal and leukemic precursor B cells by labeling precursor B cells with the fluorescent dye carboxyfluorescein diacetate, succinimyl ester. Based on the rate of decreasing fluorescent signal over 3 weeks, normal CD19(+), CD10(+) precursor B cells divided once every 90.5 hours, a number that correlates well with the known in vivo rate of 65.5 hours. The division rates were similar among different cultures and constant throughout the 3 weeks of culture, suggesting that the variable expansions of precursor B cells seen among different samples and culture durations are not secondary to different cell division rates. Unlike normal cells, cultured leukemic B cells had a heterogeneous division rate that ranged from once every 26-240 hours. These rates correlated well with their respective in vivo proliferation index. These findings indicate that the stroma-based cultures faithfully replicate in vivo cell division rates and can be used to elucidate the pathways that regulate cell division of primary human precursor B cells.     

Astigmatism after small-incision clear corneal cataract extraction and intraocular lens implantation in children

PURPOSE: To investigate the magnitude of postoperative astigmatism in children having cataract extraction with intraocular lens (IOL) implantation through a 3.0 mm superior clear corneal incision. SETTING: Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA. METHODS: This retrospective chart review comprised all pediatric patients having cataract surgery with IOL implantation through a 3.0 mm clear corneal incision from 1997 to 2002. One hundred two eyes of 75 patients were included. All refractions were performed manually by an experienced pediatric ophthalmologist. RESULTS: The mean postoperative retinoscopic cylinder in all patients was 0.63 diopter (D) (range 0.0 to 4.50 D) at 1 month, 0.40 D (range 0.0 to 1.75 D) at 6 months, and 0.51 D (range 0.0 to 2.50 D) at 1 year. Patients aged 0 to 36 months at the time of surgery had a mean postoperative cylinder of 0.22 D at 1 month, 0.03 D at 6 months, and 0.21 D at 1 year. Patients between 36 months and 6 years of age at surgery had a mean refractive cylinder of 0.50 D, 0.38 D, and 0.75 D, respectively. Patients older than 6 years at surgery had a mean refractive cylinder of 0.94 D, 0.75 D, and 0.76 D, respectively. CONCLUSIONS: Small-incision clear corneal cataract extraction with IOL implantation in children led to minimal postoperative astigmatism that remained stable over time. Less astigmatism was observed in children having surgery before they were 36 months old.     

Cognitive performance and subjective experience during combined exposures to whole-body vibration and noise

Objective The goal of this study was to examine the effects of noise and whole-body vibration, individually and combined, and at various stimulus intensity levels, on cognitive performance and subjective experience.Method Fifty-four participants (27 men and 27 women) with a mean age of 25 years, ranging from 19 to 30, were exposed for 20 min each to a 16-Hz sinusoidal whole-body vibration, a helicopter sound at 21 Hz, both stimuli combined, and a control condition. Participants were randomly assigned to one of three groups: low intensity [77 dB(A) noise and 1.0 m/s² vibration], medium intensity [81 dB(A)/1.6 m/s²] or high intensity [86 dB(A)/2.5 m/s². During each environmental exposure, short-term memory performance was tested with a visual Sternberg paradigm. Reaction time was measured as a dependent variable. Directly following each environmental exposure, participants rated the difficulty of the task and the annoyance level of the exposure stimulus.Results Results revealed no significant changes in reaction times due to environmental exposure or intensity level. However, participants significantly rated the combined exposure as both more annoying and more difficult than the other conditions. Further, the high-intensity group rated subjective annoyance significantly higher than the other groups for all conditions.Conclusions The results from this study indicate that performance alone is not a sufficient measure for the study of the effects of combined stimuli on a human operator.     

CT-derived estimation of cochlear morphology and electrode array position in relation to word recognition in Nucleus-22 recipients

This study extended the findings of Ketten et al. [Ann. Otol. Rhinol. Laryngol. Suppl. 175:1–16 (1998)] by estimating the three-dimensional (3D) cochlear lengths, electrode array intracochlear insertion depths, and characteristic frequency ranges for 13 more Nucleus-22 implant recipients based on in vivo computed tomography (CT) scans. Array insertion depths were correlated with NU-6 word scores (obtained one year after SPEAK strategy use) by these patients and the 13 who used the SPEAK strategy from the Ketten et al. study. For these 26 patients, the range of cochlear lengths was 29.1–37.4 mm. Array insertion depth range was 11.9–25.9 mm, and array insertion depth estimated from the surgeon's report was 1.14 mm longer than CT-based estimates. Given the assumption that the human hearing range is fixed (20–20,000 Hz) regardless of cochlear length, characteristic frequencies at the most apical electrode (estimated with Greenwood's equation [Greenwood DD (1990) A cochlear frequency–position function of several species–29 years later. J Acoust. Soc. Am. 33: 1344–1356] and a patient-specific constant as) ranged from 308 to 3674 Hz. Patients' NU-6 word scores were significantly correlated with insertion depth as a percentage of total cochlear length (R = 0.452; r2 = 0.204; p = 0.020), suggesting that part of the variability in word recognition across implant recipients can be accounted for by the position of the electrode array in the cochlea. However, NU-6 scores ranged from 4% to 81% correct for patients with array insertion depths between 47% and 68% of total cochlear length. Lower scores appeared related to low spiral ganglion cell survival (e.g., lues), aberrant current paths that produced facial nerve stimulation by apical electrodes (i.e., otosclerosis), central auditory processing difficulty, below-average verbal abilities, and early Alzheimer's disease. Higher scores appeared related to patients' high-average to above-average verbal abilities. Because most patients' scores increased with SPEAK use, it is hypothesized that they accommodated to the shift in frequency of incoming sound to a higher pitch percept with the implant than would normally be perceived acoustically.     

Survival of some medically important fungi on hospital fabrics and plastics

Tests of the survival of Candida spp., Aspergillus spp., a Fusarium sp., a Mucor sp., and a Paecilomyces sp. on hospital fabrics and plastics indicated that viability was variable, with most fungi surviving at least 1 day but many living for weeks. These findings reinforce the need for appropriate disinfection and conscientious contact control precautions.     

Tutorials in clinical research: part III. Selecting a research approach to best answer a clinical question

OBJECTIVE: This is the third in a series of sequential "Tutorials in Clinical Research." The objectives of this specific report are to enable the reader to rapidly dissect a clinical question or article to efficiently determine what critical mass of information is required to answer the question and what study design is likely to produce the answer. STUDY DESIGN: Tutorial. METHODS: The authors met weekly for 3 months exploring clinical problems and systematically recording the logic and procedural pathways from multiple clinical questions to the selection of proper research approaches. The basic elements required to understand the processes of selection were catalogued and field tested, and a report was produced to define and explain these elements. RESULTS: Fundamental to a research approach is the assembly of subjects and the allocation of exposures. An algorithm leading to the selection of an approach is presented. The report is organized into three parts. The tables serve as a rapid reference section. The initial two-part narrative explains the process of approach selection. The examples section illustrates the application of the selection algorithm. CONCLUSIONS: Selecting the proper research approach has six steps: the question, logic and ethics,identification of variables, data display considerations, original data source considerations, and selection of prototypical approaches for assembly of subjects. Field tests of this approach consistently demonstrated its utility.