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Biomedical subjects

D Stephens

Publications and source records attributed to D Stephens.

At least 73 records · Page 4Linked to original sources
PubMed2000

Subcategories of patients with King-Kopetzky syndrome.

King-Kopetzky syndrome (Obscure Auditory Dysfunction, OAD) has been recognized as a clinically distinct condition in audiological and ENT clinics. It is characterized by normal hearing thresholds on pure tone audiometry (PTA) but complaints of difficulties in understanding speech in the presence of background noise. In a study on 110 consecutive patients with King-Kopezky syndrome referred to the Welsh Hearing Institute, subjects were subdivided into seven subcategories based on sensitized measures of auditory dysfunction and on psychological assessment. These were: (1) middle ear dysfunction; (2) mild cochlear pathology; (3) central/medial olivocochlear efferent system (MOCS) auditory dysfunction; (4) purely psychological problems; (5) multiple auditory pathologies; (6) combined auditory dysfunction and psychological problems and (7) unknown. Different subgroups may represent different pathogenic and aetiological factors. Thus, subcategorization provides further understanding of the basis of King-Kopetzky syndrome, and hence may guide the rehabilitative management of these patients.

Adolescent↗
PubMed1999

Risk factors for resistance to "first-line" antimicrobials among urinary tract isolates of Escherichia coli in children.

BACKGROUND: There are increasing concerns regarding antimicrobial resistance in Canada. Data are limited on the prevalence, patterns of resistance and risk factors associated with resistant organisms, including coliforms, in children. This study was done to address these issues as they relate to urinary tract isolates of Escherichia coli in a tertiary care pediatric centre in Ottawa. METHODS: A surveillance study was conducted from December 1992 to December 1994. Susceptibility testing of urinary tract isolates of E. coli was performed using a panel of antimicrobial agents. A case-control study was also conducted for subjects with isolates resistant to trimethoprim-sulfamethoxazole (T-S), this drug being used a representative "first-line" agent. RESULTS: A total of 1636 consecutive isolates were obtained from 967 subjects. Of the 1636 isolates, 736 (45.0%) were resistant to ampicillin, 514 (31.4%) were resistant to T-S, 363 (22.2%) were resistant to both ampicillin and T-S, and 27 (1.7%) were resistant to both ampicillin and gentamicin. In the case-control study 274 children with isolates resistant to T-S were matched with 274 children who had T-S-sensitive isolates obtained during the study period or the preceding or subsequent 6 months. Multivariate analyses indicated that subjects who had received antimicrobials for more than 4 weeks in the previous 6 months were about 23 times more likely to have isolates resistant to T-S than were subjects without this risk factor (odds ratio [OR] 23.4, 95% confidence interval [CI] 12.0-47.6). Children with genitourinary tract abnormalities were 2.4 times more likely to have resistant isolates than those without such abnormalities (95% CI 1.2-4.5). Compared with children who had no hospital admissions in the previous year, those with 1 admission in that period were more likely to have resistant isolates (OR 2.3, 95% CI 1.4-7.5), as were those with 2 or more admissions in that period (OR 3.2, 95% CI 1.1-4.8). Compared with children aged 2-6 years, children under 2 years of age were less likely to have resistant isolates (OR 0.3, 95% CI 0.2-0.8). INTERPRETATION: Selective antimicrobial pressure and multiple admissions to hospital were among the risk factors associated with antimicrobial resistance. The finding of a low but definite level of resistance to both ampicillin and gentamicin is important for the selection of empiric therapy for sepsis in neonates. The role of inexpensive first-line agents in the outpatient treatment and prevention of urinary tract infections requires re-examination, particularly in children who have recently received antimicrobial therapy.

Anti-Bacterial Agents↗
PubMed1999

Comparison of albuterol delivered by a metered dose inhaler with spacer versus a nebulizer in children with mild acute asthma.

OBJECTIVE: In children with mild acute asthma, to compare treatment with a single dose of albuterol delivered by a metered dose inhaler (MDI) with a spacer in either a weight-adjusted high dose or a standard low-dose regimen with delivery by a nebulizer. STUDY DESIGN: In this randomized double-blind trial set in an emergency department, 90 children between 5 and 17 years of age with a baseline forced expiratory volume in 1 second (FEV1 ) between 50% and 79% of predicted value were treated with a single dose of albuterol, either 6 to 10 puffs (n = 30) or 2 puffs (n = 30) with an MDI with spacer or 0.15 mg/kg with a nebulizer (n = 30). RESULTS: No significant differences were seen between treatment groups in the degree of improvement in percent predicted FEV1 (P =.12), clinical score, respiratory rate, or O2 saturation. However, the nebulizer group had a significantly greater change in heart rate (P =.0001). Our study had 93% power to detect a mean difference in percent predicted FEV1 of 8 between the treatment groups. CONCLUSION: In children with mild acute asthma, treatment with 2 puffs of albuterol by an MDI with spacer is just as clinically beneficial as treatment with higher doses delivered by an MDI or by a nebulizer.

Adolescent↗
PubMed1999

Detrimental effects of alcohol on tinnitus.

The present study has examined the detrimental effects which alcohol has on tinnitus in a consecutive series of 51 patients seen in a tinnitus clinic and reporting such an effect. Eighty-four per cent of those studied reported that the level of the tinnitus was increased by the alcohol, 73% that they became more aware of it, and 47% that it increased the effect of the alcohol on their sleep. Compared with patients reporting beneficial effects on tinnitus, they consumed less alcohol, they comprised a higher proportion of younger females, and they were more likely to report that their tinnitus was worse the next day. There were no marked differences between the effects of different types of alcohol.

Adult↗
PubMed1999

A patient-based voucher system of brief hospitalisation.

OBJECTIVE: The aim of this study was to demonstrate the clinical use of a patient-based voucher system for brief hospitalisation. CLINICAL PICTURE: A 31-year-old male, chronically disabled, with schizophrenia, polysubstance, and borderline personality disorders presented concerns for the treating team. TREATMENT: Management was community based except for a single admission in which the patient chose the timing and duration via a predetermined set of vouchers. OUTCOME: In contrast to previous admissions, a patient-chosen, voucher-based admission was single, brief and uneventful. CONCLUSIONS: Novel approaches to chronically disabled patients with psychiatric illness enable change from therapeutic pessimism. A patient-based voucher system seemed to be of use in one patient.

Adult↗
PubMed1999

Audioscan testing in patients with King-Kopetzky syndrome.

In this study, the Audioscan test has been used to detect early signs of hearing abnormalities in 80 patients with King-Kopetzky syndrome. A significantly higher prevalence of Audioscan notches between 500 and 3,000 Hz was found for each age band and gender in patients with King-Kopetzky syndrome than in control subjects. This indicates that Audioscan notches between 500 and 3,000 Hz may represent a fine hearing deficit as an indicator of mild auditory dysfunction in patients with King-Kopetzky syndrome. However, there was no significant difference in the percentage of notches in the 3,001-8,000 Hz frequency band between the King-Kopetzky syndrome and control groups.

Acoustic Stimulation↗
PubMed1999

Test-retest variability of distortion-product otoacoustic emissions in human ears with normal hearing.

In the present study, the test-retest variability of distortion product otoacoustic emissions (DPOAEs) due to various causes has been assessed quantitatively at individual frequencies using the ILO88/92 system. The short-term variance was generally lower than 3 dB2. Changing the position and the fit of the probe may affect the level of background noise in the ear canal, which interferes with the responses of the DPOAEs mainly at low frequencies and can also influence the interaction of the resonances of the outer ear and acoustic stimuli. The long-term variance was significantly greater than short-term variance, but did not differ significantly from variance of refitting the probe. The total DPOAE variance was small across all the frequencies above 1000 Hz except for a small peak in the 2500 Hz range. This may be related to the low response amplitudes in this region. The limitation of DPOAE detection at frequencies below 1000 Hz must lead to caution in the interpretation of results in this frequency range. The magnitude of the total variance was similar to that found in audiometric studies.

Acoustic Stimulation↗
PubMed1999

A statistical experimental approach to cosolvent formulation of a water-insoluble drug.

19-Nor-1 alpha, 25-dihydroxyvitamin D2, an analog of vitamin D2, is a nonpolar compound with limited solubility in water. An injectable solution was formulated using a cosolvent system consisting of water, ethanol, and propylene glycol. A statistical response surface approach was used to evaluate the effect of these three solvents on the solubility of the drug (25 degrees C) in the ternary cosolvent system. The data generated from five selected formulations were used to develop a multiple linear regression model that quantitatively defines the solubility of the drug as a function of the cosolvent composition. Close agreement was found between the experimental data and data calculated using the model. The capability of this model to predict drug solubility in cosolvent systems with various combinations of the three solvents was also verified.

Chemistry, Pharmaceutical↗
PubMed1999

Additive contribution of nitrous oxide to sevoflurane minimum alveolar concentration for tracheal intubation in children.

BACKGROUND: To study the interaction between nitrous oxide and sevoflurane during trachea intubation, the authors determined the minimum alveolar concentration of sevoflurane for tracheal intubation (MAC(TI)) with and without nitrous oxide in children. METHODS: Seventy-two children aged 1-7 yr were assigned randomly to receive one of three end-tidal concentrations of nitrous oxide and one of four end-tidal concentrations of sevoflurane: 0% nitrous oxide with 2.0, 2.5, 3.0, or 3.5% sevoflurane: 33% nitrous oxide with 1.5, 2.0, 2.5, or 3.0% sevoflurane; or 66% nitrous oxide with 1.0, 1.5, 2.0, or 2.5% sevoflurane. After steady state end-tidal anesthetic concentrations were maintained for at least 10 min, laryngoscopy and intubation were attempted using a straight-blade laryngoscope and an uncuffed tracheal tube. The interaction between nitrous oxide and sevoflurane was investigated using logistic regression analysis of the responses to intubation. RESULTS: Logistic regression curves of the probability of no movement in response to intubation in the presence of sevoflurane and 0, 33, and 66% nitrous oxide were parallel. The interaction coefficient between nitrous oxide and sevoflurane did not differ significantly from zero (P = 0.89) and was removed from the logistic model. The MAC(TI) (+/- SE) of sevoflurane was 2.66+/-0.16%, and the concentration of sevoflurane required to prevent movement in 95% of children was 3.54+/-0.25%. Thirty-three percent and 66% nitrous oxide decreased the MAC(TI) of sevoflurane by 18% and 40% (P<0.001), respectively. CONCLUSIONS: We conclude that nitrous oxide and sevoflurane suppress the responses to tracheal intubation in a linear and additive fashion in children.

Age Factors↗
PubMed1999

Development of a quality-of-life index for pediatric inflammatory bowel disease: dealing with differences related to age and IBD type.

BACKGROUND: A child- and adolescent-generated IBD quality-of-life index was designed to be descriptive (to be used to assess the overall impact of IBD on individual patients), and evaluative (to be used as an outcome measure in clinical trials). METHODS: Item-generation and item-reduction interviews with 82 patients with IBD aged 8 to 17 years (61 with Crohn's disease, 21 with ulcerative colitis; 36 girls, 45 boys) generated a list of ways in which their lives were affected by IBD. These issues were incorporated into an item-reduction questionnaire, which was administered to 117 patients (87 Crohn's disease, 30 ulcerative colitis). Patients indicated on a visual analog scale how important an item was to them and how often it bothered them. Mean and median importance-plus-frequency scores for each issue were calculated for the entire group and among patients in subgroups according to age and IBD type. RESULTS: Ulcerative colitis and Crohn's disease affect the lives of children and adolescents differently. Bowel symptoms are more troubling and disabling to patients with ulcerative colitis, whereas systemic symptoms and body image concerns are greater for patients with Crohn's disease. The impact of Crohn's disease on ability to function in school and leisure activities is greater. Worries about future health problems and about the effects of IBD on the family are shared. Crohn's disease and ulcerative colitis trigger emotional responses of unfairness and frustration, but anger and embarrassment are more prevalent in ulcerative colitis. Disparities between age groups are fewer and less marked than those between types of IBD. CONCLUSION: In selection of items to be retained in a pediatric IBD quality-of-life measure, the variation in concerns with disease type must be considered. A single index to assess IBD-related quality of life must include items of major importance to one subgroup of patients, even if not important to all. Alternately, a core of common concerns could be supplemented by disease-specific modules, thereby increasing the content validity of the tool for all patients.

Adolescent↗
PubMed1999

Variable morbidity of respiratory syncytial virus infection in patients with underlying lung disease: a review of the PICNIC RSV database. Pediatric Investigators Collaborative Network on Infections in Canada.

OBJECTIVE: We wished to compare outcomes of respiratory syncytial virus (RSV) infection in children with bronchopulmonary dysplasia (BPD) with those with other pulmonary disorders: cystic fibrosis, recurrent aspiration pneumonitis, pulmonary malformation, neurogenic disorders interfering with pulmonary toilet, and tracheoesophageal fistula. METHODS: Children with RSV infection hospitalized at seven Canadian pediatric tertiary care hospitals in 1993 through 1994 and 9 hospitals in 1994 through 1995 were enrolled and prospectively followed. This study is a secondary analysis of data from this prospective cohort. RESULTS: Of the 1516 patients enrolled the outcomes of 159 with preexisting lung disorders before RSV lower respiratory tract infection constitute this report. There were no significant differences among the 7 groups (BPD, cystic fibrosis, recurrent aspiration pneumonitis, pulmonary malformation, neurogenic disorders interfering with pulmonary toilet, tracheoesophageal fistula, other) for the morbidity measures: duration of hospitalization, intensive care unit (ICU) admission, duration of ICU stay, mechanical ventilation and duration of mechanical ventilation. Patients using home oxygen were more likely to be admitted to the ICU than those who had never or previously used home oxygen (current 57.1%, past 23.8%, never 33.3%, P = 0.03). CONCLUSIONS: Children with other underlying diseases have morbidity similar to those with BPD. Prophylactic interventions against RSV should also be studied in these groups.

Bronchopulmonary Dysplasia↗
PubMed1999

A comparison of male and female adolescents referred to an eating disorder program.

OBJECTIVE: To compare gender-related psychopathology and psychiatric diagnoses in male and female adolescents referred to an adolescent eating disorder program. METHOD: All adolescents presenting at the Eating Disorder Program at our hospital completed the semistructured Diagnostic Interview for Children and Adolescents-Revised (DICA-R) and self-report scales, including the Children's Depression Inventory (CDI), the Brief Symptom Inventory (BSI), the Eating Disorder Inventory (EDI-2), and the Family Assessment Measure (FAM-III), during their initial assessment. The 157 subjects (21 male, 136 female) were classified into Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) eating disorder (ED) subtypes and then recombined into male and female restricters (R) and ED-related groups: showing eating-related concerns but not having a DSM-IV diagnosis. We compared the male and female restricter groups and ED-related group on 5 specific psychological dimensions to examine comorbid psychiatric diagnosis, ED-specific and nonspecific psychopathology, EDI clinical and provisional subscales, and family functioning using multivariate analyses of covariance (MANCOVAs). RESULTS: Males endorsed statistically significant lower drive for thinness and body dissatisfaction than did females. However, there are no representative norms for adolescent males on these variables. The ED-related group also endorsed statistically significant lower drive for thinness and body dissatisfaction (specific ED psychopathology) than did the ED-restricter groups. The males in both groups endorsed fewer EDI items than did their female counterparts, but the differences were not statistically significant. Comorbid psychiatric diagnoses of depression and anxiety in male and female restricters were common but did not distinguish the groups. CONCLUSIONS: Our results suggest that male and female adolescents with EDs are clinically similar to each other and therefore resemble adults for lack of gender-specific effects on self-reported psychopathology, family functioning, and comorbid psychiatric disorders.

Adolescent↗
PubMed1999

Improving smooth sailing between hospital and home.

A unique, collaborative project was undertaken by a large acute care facility and its affiliated multisite home health agency. Educational practices within the network were evaluated and improved, resulting in increased patient and staff outcomes.

Community Health Nursing↗
PubMed1998

The Platelet Function Analyzer (PFA-100): a novel in-vitro system for evaluation of primary haemostasis in children.

The PFA-100 system provides an in-vitro method of assessing primary platelet-related haemostasis by measuring the time (the closure time, or CT) taken for a platelet plug to occlude a microscopic aperture cut into a membrane coated with collagen and either epinephrine or ADP. We used the system to establish normal ranges for CTs in healthy children, adults and neonates. Mean CTs of healthy children were independent of the needle gauge used (21G or 23CG) for blood sampling; they were very similar to the mean CTs of healthy adults, but longer than mean CTs of healthy neonates. Although children with haemophilia had normal CTs, the PFA-100 system was found to be potentially useful in screening for von Willebrand disease in children.

Adolescent↗
PubMed1998

Use of patient-specific estimates in patient evaluation and rehabilitation.

For a number of years we have been using open-ended questionnaires in the assessment of hearing disability and handicap, tinnitus complaint behaviour together with shortcomings and benefits of various rehabilitative interventions. More recently we have applied this approach to positive experiences reported by adults who have developed a hearing impairment and to the use of silence or social withdrawal as a communication tactic. In addition, we have asked individuals to rate the magnitude of each of their listed disabilities, handicaps, shortcomings, etc., on a scale to provide a qualitative assessment of each of these elements important to the individual. Such a procedure can be repeated after the intervention to measure changes in such estimates. This approach can thus highlight for the therapist, those elements of the patients' problems which are being well or poorly addressed and hence help them to concentrate their effort on the latter. Results obtained using this technique are presented and discussed.

Aged↗
PubMed1998

Variation in the measurements of basement membrane thickness and inflammatory cell number in bronchial biopsies.

We do not have an estimate of how much tissue is needed for a reliable measure of bronchial epithelial reticular basement membrane (RBM) thickness or for counts of inflammatory cells. An assessment of the frequency distribution and variance of data from repeat measurements of RBM thickness and biopsy section inflammatory cell counts in cases with asthma (n=6), chronic obstructive pulmonary disease (COPD; n=5), and normal healthy subjects (n=7) was made. Tissue sections were stained with haematoxylin and eosin or by immunohistochemistry for EG2, mast cell tryptase and CD3-positive cells. Measurements of RBM thickness in individuals followed a log-normal distribution. For a precision of approximately +/-15%, 31-45 measurements were required. In contrast, inflammatory cell counts for each individual did not follow a normal distribution. There was high variance such that the cumulative weighted mean did not become stable until at least 5-10 mm of tissue underlying the RBM had been included. In conclusion multiple measurements of reticular basement membrane thickness or tissue section cell counts should be made for each individual in studies of bronchial biopsies. It is recommended that reticular basement membrane thickness should be measured at 20 mm intervals over a 1 mm reticular basement membrane length and that a zone beneath it of at least 5-10 mm of reticular basement membrane should be included for counts of inflammatory cells.

Adult↗