Biomedical subjects

Linda Nelson

Publications and source records attributed to Linda Nelson.

5 recordsLinked to original sources

PubMed2006

Impact of acute rotavirus gastroenteritis on pediatric outpatient practices in the United States.

OBJECTIVES: The objectives of this study were to determine the presenting symptoms, healthcare utilization, and lost time from work and day care associated with acute rotavirus gastroenteritis. METHODS: During the winter to spring seasons of 2002-2003 or 2003-2004, children <36 months of age presenting with acute gastroenteritis to urban and suburban pediatric outpatient practices affiliated with 5 academic centers across the United States were enrolled in similarly designed studies. The case definition required >or=3 watery or looser-than-normal stools and/or forceful vomiting within a 24-hour period beginning <or=72 hours before presentation. Stool samples were tested for rotavirus antigen by standard commercial assays. Symptom frequencies for laboratory-confirmed rotavirus and nonrotavirus gastroenteritis were compared by Fisher's exact test; the number of healthcare contacts and lost days from work or day care were compared with the median 2-sample test. RESULTS: Stool specimens were obtained from 284 of 303 (94%) participants; 115 (40%) of tested specimens were positive for rotavirus (range, 31-50% across the 5 centers). Compared with participants with nonrotavirus gastroenteritis, children with rotavirus gastroenteritis were more likely to have 1) vomiting (83% versus 66%; P = 0.003), 2) combined diarrhea and vomiting (75% versus 50%; P < 0.001), and 3) fever (60% versus 43%; P = 0.010). More time from work was lost by parents/guardians of children with rotavirus than nonrotavirus gastroenteritis (median 2 versus 0 day; P = 0.007). More day care was missed by children with rotavirus than nonrotavirus gastroenteritis (median 3 versus 1 day; P = 0.002). CONCLUSIONS: In this multicenter study, rotavirus consistently caused a sizable proportion of cases of acute gastroenteritis seen in pediatric outpatient practices in the United States during the winter and spring. Rotavirus gastroenteritis was more frequently associated with vomiting, combined diarrhea and vomiting, fever and lost time from work and day care than nonrotavirus gastroenteritis.

Acute Disease↗

PubMed2005

Renal and vestibular toxicity due to inhaled tobramycin in a lung transplant recipient.

Chronic rejection is the major hurdle to long-term survival after lung transplantation. Endobronchial infection with Pseudomonas aeruginosa is common in patients with chronic rejection and this may further contribute to deterioration of the allograft. Inhaled tobramycin is commonly used to treat P aeruginosa airways infection in patients with cystic fibrosis. The safety of inhaled tobramycin in transplant recipients, however, has not been established. We describe the first report of a lung transplant recipient who developed renal failure and vestibular injury after receiving inhaled tobramycin. We review the literature regarding the safety of inhaled tobramycin and discuss potential mechanisms that may promote systemic toxicity in transplant recipients.

Administration, Inhalation↗

PubMed2005

Learning and memory as a function of age in Down syndrome: a study using animal-based tasks.

Individuals with Down syndrome (DS) are at a high risk for developing Alzheimer disease (AD) after the age 40; however, low levels of intellectual functioning, coupled with impaired language ability, confound the detection of AD. Comparative neuropsychological tests developed in animal models of aging and cognition do not require intact language function and can be useful for detecting changes in cognition. Experimental paradigms used to detect age-dependent cognitive deficits in animal models were applied in the present study to measure cognitive function in a group of 20 adults with DS ranging in age from 22 to 58 years. Object discrimination, reversal learning, and spatial and object memory were administered using a modified Wisconsin General Testing Apparatus and reinforcement (penny rewards). When considering age as the only clinical variable to parallel the animal studies, age was significantly correlated with performance on object memory and marginally related to performance on reversal learning and spatial memory. However, when evaluating multiple clinical variables including age, a measure of intellectual ability (FSIQ), scores on the Dementia Questionnaire for Persons with Mental Retardation (DMR), and gender using regression analysis, scores on the DMR were the best predictors of errors of reversal learning, whereas FSIQ was the best predictor of performance on object memory. These results suggest that while age may be related to performance on learning and memory tasks, other clinical variables may be stronger predictors of performance in adults with DS. These changes may reflect prefrontal and medial temporal lobe dysfunction that is associated with the development of AD pathology in DS.

Adult↗

PubMed2004

Randomized pilot study of a new atrial-based minimal ventricular pacing mode in dual-chamber implantable cardioverter-defibrillators.

OBJECTIVE: We hypothesized that a new minimal ventricular pacing mode (MVP) that provides AAI/R pacing with ventricular monitoring and back-up DDD/R pacing as needed during AV block (AVB) would significantly reduce cumulative percent ventricular pacing compared to DDD/R. BACKGROUND: Conventional DDD/R mode often results in high cumulative percent ventricular pacing that may adversely affect ventricular function and increase risk of heart failure and atrial fibrillation. METHODS: MVP was made operational in 30 patients with DDD/R implantable cardioverter-defibrillators (ICDs) and no history of AVB. Patients were randomized to one week each in DDD/R and MVP. Holter monitor recordings (ECG, intracardiac electrograms, and event markers) and device diagnostics were analyzed for cumulative % atrial paced (Cum%AP), cumulative percent ventricular pacing, and frequency and duration of DDD/R pacing back-up. Diaries were used to report symptoms. RESULTS: Age of the study population was 61 years +/- 12 years and 83% were male. Baseline PR interval was 204 ms +/- 32 ms and programmed AV intervals (DDD/R) were 200 ms +/- 50 ms (paced)/167 ms +/- 54 ms (sensed). Cum%AP was similar between MVP and DDD/R (47.9 +/- 37 vs 46.3 +/- 36). Cumulative percent ventricular pacing was significantly lower in MVP vs DDD/R (3.79 +/- 16.3 vs 80.6 +/- 33.8, P < .0001). Back-up DDD/R pacing during MVP operation due to transient AVB occurred in 10% of patients (9.3 +/- 7.4 [range 1-15] episodes/patient-day, duration 39.7 minutes +/- 156 minutes). Fifteen percent of AV intervals during MVP operation exceeded 300 ms. No significant symptoms were reported during MVP operation. CONCLUSIONS: MVP dramatically reduced cumulative percent ventricular pacing compared to DDD/R while maintaining AV synchrony and providing sensor-modulated atrial pacing support. Intermittent oscillations between MVP and DDD/R during transient AV block appeared safe and well tolerated.

Atrioventricular Node↗

PubMed2002

Down syndrome and Alzheimer disease: response to donepezil.

BACKGROUND: Individuals with Down syndrome who develop Alzheimer disease may show an improvement in cognitive functioning after treatment with acetylcholinesterase inhibitors. OBJECTIVE: To determine whether individuals with Down syndrome and Alzheimer disease will show improvement after institution of donepezil treatment. DESIGN: A nonrandomized controlled trial using donepezil in a pilot study format. SETTING: Academic medical center. PATIENTS: Convenience sample of 6 treated patients with Down syndrome and 9 closely matched historical control subjects. INTERVENTION: Oral administration of donepezil for a 5-month period. PRIMARY OUTCOME MEASURE: The Down Syndrome Dementia Scale. RESULTS: Significant improvement in dementia scores for the treated group during a 3- to 5-month period (P =.03). CONCLUSIONS: Acetylcholinesterase inhibitors may be helpful in reversing the symptoms of dementia during early and middle stages of cognitive decline. These findings support the rationale for a more extensive study of the efficacy of acetylcholinesterase inhibitors in Down syndrome dementia.

Alzheimer Disease↗