Biomedical subjects

Richard Casey

Publications and source records attributed to Richard Casey.

10 recordsLinked to original sources

PubMed2006

Racial and ethnic differences in unmet need for vision care among children with special health care needs.

OBJECTIVE: To examine racial and ethnic differences in unmet need for vision care among children with special health care needs. METHODS: Cross-sectional data from the National Survey of Children with Special Health Care Needs were analyzed. The analytic sample was 14,070 children with special health care needs who needed eyeglasses or vision care in the previous year. Children who did not receive all the eyeglasses or vision care they needed were considered to have unmet need for vision care. RESULTS: Of the sample, 5.8%, representing approximately 198,600 children with special health care needs in the United States, had unmet need for vision care. Rates of unmet need ranged from 2.5% to 14.3% across the 7 racial and ethnic groups studied. Relative to whites, children of African American, Latino, and multiracial backgrounds had approximately twice the adjusted risk of unmet need, whereas American Indian or Alaskan Native children had a lower adjusted risk. Health care providers, school personnel, insurance coverage, and other factors also contributed to differences in the risk of unmet need, independently of child race/ethnicity. CONCLUSION: Further research is needed to explain and address the causes of racial and ethnic differences in unmet need for vision care among children with special health care needs.

Adolescent↗

PubMed2006

Measuring quality of life: the development and initial validation of the patient-reported erectile function assessment instrument.

OBJECTIVES: Erectile dysfunction (ED) is a complex condition, which is variously influenced by physical, emotional, societal, and relationship factors. ED has serious implications for the quality of life (QoL) enjoyed by an affected male and his partner. It is very important, therefore, to understand the impact of ED on the QoL of those affected by it. Our objective was to determine if the eight-question Patient Reported Erectile Function Assessment (PREFA) could act as an independent, comprehensive disease-specific instrument in the assessment of QoL as it is impacted by ED. METHODS: During the development and validation of the Erectile Function-Visual Analog Scale (EF-VAS) (14), a new ED-specific preference-based instrument, a series of questions were included at the beginning of the assessment that would act as a way to encourage respondents to focus on their own experience with ED. Upon analysis of the EF-VAS data, it became apparent that the eight-question "warm up" section might act as a stand-alone assessment. Accordingly, the eight questions were named PREFA, and a validation analysis was undertaken to determine their consistency, feasibility, reliability, validity, and responsiveness. RESULTS: The PREFA questionnaire was found to be feasible and simple to complete, reliable, and valid, with excellent responsiveness. Overall, the PREFA has demonstrated that it can perform as a stand alone, validated assessment of the impact of ED on QoL, assessing areas of QoL not previously captured in existing instruments. CONCLUSIONS: The PREFA is suitable for use in clinical and research settings as a disease-specific QoL assessment tool.

Erectile Dysfunction↗

PubMed2006

A double-blind randomized dose-response study comparing daily doses of 5, 10 and 15 mg controlled-release oxybutynin: balancing efficacy with severity of dry mouth.

OBJECTIVE: To assess the efficacy, incidence of dry mouth and overall satisfaction with initial doses of 5, 10 and 15 mg of a new, once-daily, controlled-release (CR) form of oxybutynin for treating urge urinary incontinence (UUI). PATIENTS AND METHODS: Patients who reported urinary incontinence (UI) (one or more episodes/diary) and voiding frequency (eight or more voids/day) or urgency (one or more episodes/diary) during a 2-week baseline were randomized to once-daily 5, 10 or 15 mg CR oxybutynin for 4 weeks. Daily episodes of UI, voids, urgency, adverse events, dry mouth and satisfaction were recorded in a 3-day diary at baseline and after 4 weeks of treatment. In all, 237 patients were randomized and evaluated. RESULTS: Episodes of UI, voids and urgency were significantly reduced over the study period at all doses. Daily UI episodes were significantly lower with 15 mg/day than 5 and 10 mg/day. Dry mouth symptoms were similar in the 10 and 15 mg/day groups, and higher than in the 5 mg/day group. However, significantly greater overall satisfaction was reported with 15 than 5 mg/day. CONCLUSIONS: There were significant dose-response relationships with CR oxybutynin for both UI episodes and dry mouth. The greatest satisfaction was with 15 mg/day, and the severity of dry mouth was comparable at 10 mg/day, indicating that greater efficacy at the higher dose did not compromise tolerability.

Adult↗

PubMed2005

Piecewise-linear models of genetic regulatory networks: equilibria and their stability.

A formalism based on piecewise-linear (PL) differential equations, originally due to Glass and Kauffman, has been shown to be well-suited to modelling genetic regulatory networks. However, the discontinuous vector field inherent in the PL models raises some mathematical problems in defining solutions on the surfaces of discontinuity. To overcome these difficulties we use the approach of Filippov, which extends the vector field to a differential inclusion. We study the stability of equilibria (called singular equilibrium sets) that lie on the surfaces of discontinuity. We prove several theorems that characterize the stability of these singular equilibria directly from the state transition graph, which is a qualitative representation of the dynamics of the system. We also formulate a stronger conjecture on the stability of these singular equilibrium sets.

Genes, Regulator↗

PubMed2005

Activity-independent coregulation of IA and Ih in rhythmically active neurons.

The fast transient potassium or A current (IA) plays an important role in determining the activity of central pattern generator neurons. We have previously shown that the shal K+ channel gene encodes IA in neurons of the pyloric network in the spiny lobster. To further study how IA shapes pyloric neuron and network activity, we microinjected RNA for a shal-GFP fusion protein into four identified pyloric neuron types. Neurons expressing shal-GFP had a constant increase in IA amplitude, regardless of cell type. This increase in IA was paralleled by a concomitant increase in the hyperpolarization-activated cation current Ih in all pyloric neurons. Despite significant increases in these currents, only modest changes in cell firing properties were observed. We used models to test two hypotheses to explain this failure to change firing properties. First, this may reflect the mislocalization of the expressed shal protein solely to the somata and initial neurites of injected neurons, rendering it electrically remote from the integrating region in the neuropil. To test this hypothesis, we generated a multicompartment model where increases in IA could be localized to the soma, initial neurite, or neuropil/axon compartments. Although spike activity was somewhat more sensitive to increases in neuropil/axon versus somatic/primary neurite IA, increases in IA limited to the soma and primary neurite still evoked much more dramatic changes than were seen in the shal-GFP-injected neurons. Second, the effect of the increased IA could be compensated by the endogenous increase in Ih. To test this, we modeled the compensatory increases of IA and Ih with a cycling two-cell model. We found that the increase in Ih was sufficient to compensate the effects of increased IA, provided that they increase in a constant ratio, as we observed experimentally in both shal-injected and noninjected neurons. Thus an activity-independent homeostatic mechanism maintains constant neuronal activity in the face of dramatic increases in IA.

Action Potentials↗

PubMed2005

Early symptom improvement of benign prostatic hyperplasia (BPH) treated with once daily alfuzosin.

INTRODUCTION AND OBJECTIVES: A novel slow release formulation of alfuzosin should improve compliance by reducing dosing to one 10 mg tablet per day. The current study examined efficacy, at 9 days and 3 months, and safety of this formulation of alfuzosin in BPH patients. METHODS: ALF-X was a 3-month, non-comparative, observational study of 353 BPH patients from 39 Canadian Urology centres. RESULTS: At baseline (BL), mean age was 63.1+/-9.01 years, 92.6% of patients were Caucasian, 3.4% had a history of acute urinary retention, mean duration of the micturition disorder was 48.6+/-54.15 months, and mean PSA was 3.3+/-6.65 ng/mL. Mean total International Prostate Symptom Score (I-PSS) decreased from 17.5 at BL to 10.4 at M3--an improvement of 7.1+/-6.82 points (40.6%, p < 0.001), mostly occurring (27.0%, p < 0.001)) during the first 9 days. Mean Quality of Life Assessment Index improved by 0.7+/-1.39 points between BL and D9 (17.5%, p < 0.001), and by 1.5+/-1.52 points between BL and M3 (37.5%, p < 0.001). The proportion of 'mild' I-PSS patients increased from 11.8% (BL) to 29.7% (D9) to 39.0% (M3); those with 'severe' I-PSS decreased from 37.8% (BL) to 14.5% (D9) to 9.4% (M3). Of 144 patients with nocturia (>2 nightly voidings) at D1, 51.4% improved to < or = 2 nightly voidings at D9, and 60.4% at M3. Adverse events related to alfuzosin occurred in 7.8% of patients; 2.0% experienced serious adverse events. There were no vasodilatory events related to alfuzosin or deaths. CONCLUSIONS: In routine clinical practice, slow-release alfuzosin is associated with a significant improvement in LUTS, and frequency of nocturia, and an excellent safety profile.

Adrenergic alpha-Antagonists↗

PubMed2004

Vardenafil improves patient satisfaction with erection hardness, orgasmic function, and overall sexual experience, while improving quality of life in men with erectile dysfunction.

PURPOSE: The North American Pivotal Trial was designed to investigate the efficacy and safety of vardenafil in males with erectile dysfunction (ED). MATERIALS AND METHODS: In this randomized, double-blind, placebo-controlled, multicenter, fixed-dose, parallel group, 6-month study, vardenafil at three doses (5 mg, 10 mg, and 20 mg) was compared to placebo with the primary efficacy variables being the International Index of Erectile Function (IIEF) Erectile Function (EF) domain score and per patient diary response success rates for penetration and maintenance of erection through completion of intercourse. Additional efficacy variables included IIEF domain scores measuring intercourse satisfaction, orgasmic function, sexual desire, and overall satisfaction. Diary entries for overall per patient satisfaction rates for hardness and sexual experience were also measured. Improvements in quality of sexual life were assessed using the Fugl-Meyer quality of life (QoL) questionnaire. RESULTS: Compared to placebo, patients taking 10 mg and 20 mg doses of vardenafil showed statistically significantly greater improvement in IIEF domain scores measuring intercourse satisfaction (10.3 and 10.3 vs. 7.7), orgasmic function (7.1 and 6.9 vs. 5.3), overall satisfaction. (7.1 and 7.1 vs. 5.2) for vardenafil 10 mg and 20 mg vs. placebo, respectively, at last observation carried forward (LOCF). Vardenafil 5 mg was statistically significantly better than placebo for the secondary IIEF domain variables of intercourse satisfaction (8.9 vs. 7.7) and overall satisfaction (6.3 vs. 5.2) for vardenafil vs. placebo, respectively, at LOCF. Per patient satisfaction rates for the secondary diary variables measuring erection hardness (38%, 52%, 58% and 18%) and overall satisfaction (45%, 58%, 62% and 23%) were dose dependent and statistically significantly superior for vardenafil at 5 mg, 10 mg and 20 mg compared with placebo, respectively. Patients' answers to the Fugl-Meyer QoL questionnaire assessing improvement in sexual life also indicated statistically significant superiority for all doses of vardenafil vs. placebo treatment. The most frequent adverse events (AE) in the 5 mg, 10 mg, and 20 mg of vardenafil and placebo groups, respectively, were: headache (10%, 22%, 21% and 4%), flushing (5%, 10%, 13% and 0%), dyspepsia (1%, 4%, 6% and < 1%), and rhinitis (9%, 14%, 17% and 5%). Most AEs were mild or moderate in severity and transient in nature. CONCLUSION: Vardenafil was superior to placebo for IIEF domain scores, per patient success rates for diary questions, and assessment of quality of sexual life, in a broad range of patients with ED irrespective of etiology or severity. Vardenafil was generally well tolerated, with most AEs being mild or moderate in severity and transient in nature.

Adult↗

PubMed2003

West African crystalline maculopathy.

OBJECTIVE: To describe the findings of a new crystalline maculopathy exclusively affecting elderly members of the Igbo tribe of southeast Nigeria. DESIGN: Retrospective, observational noncomparative case series. METHODS: Six patients referred over a 2-year period to the medical retina consultation service of the King/Drew Medical Center (Los Angeles, Calif) were identified as having a characteristic crystalline maculopathy. Each underwent detailed historical questioning and comprehensive ocular evaluation, including formal retinal examination. Color vision testing, fluorescein angiography, Humphrey visual field analysis, and electrophysiologic assessment were also performed. RESULTS: Each of the 6 patients was an elderly member of the Igbo tribe of southeast Nigeria and demonstrated a unique crystalline maculopathy. A central, superficial cluster of green or yellow, refractile, foveal crystals that were bilateral and asymmetric in distribution was noted in each case. The crystals were benign and unassociated with visual deficit. Retinal sequelae were notably absent and fluorescein angiography results were unremarkable. Additional ancillary testing was generally normal, although 1 patient demonstrated unexplained mild to moderate depression of the scotopic and photopic responses on electrophysiologic analysis. CONCLUSIONS: Elderly members of the Igbo tribe of southeast Nigeria may harbor characteristic bilateral but asymmetric foveal crystals, comprising a novel syndrome of crystalline maculopathy unassociated with obvious visual deficits or retinal sequelae. The etiology of this crystalline maculopathy remains unclear, although genetic, degenerative, and toxic causes are postulated.

Aged↗

PubMed2003

Efficacy and safety of ketotifen fumarate 0.025% in the conjunctival antigen challenge model of ocular allergic conjunctivitis.

PURPOSE: To determine the duration of action of ketotifen 0.025% eye drops vs placebo taken as single or multiple doses in an allergen challenge model. DESIGN: Two randomized, multicenter, double-masked, contralateral placebo-controlled studies, one a single-dose and one a multiple-dose study. METHODS: Two conjunctival provocation tests (CPTs) were initially conducted to confirm reproducibility of subject responses in both studies. Subjects in study 1 (n = 87) received single doses of ketotifen in one eye and placebo in the other 15 minutes, 6 hours, and 8 hours before CPT. Subjects in study 2 (n = 85) received ketotifen or placebo once 8 hours before CPT. Single-dose efficacy results were used to further qualify a subject as a responder. Responders were re-randomized to a 4-week twice daily dosing regimen with a CPT 8 hours after the final dose. In both studies, ocular symptoms were assessed at three time points 3 to 15 minutes after challenge. There were no significant differences in adverse events between groups. RESULTS: For both studies, ocular itching and vascular injection were significantly reduced (P <.003) at all time points after instillation of ketotifen, with a maximum reduction at 7 minutes postchallenge. In study 2, chemosis, tearing, and lid swelling were also assessed and were significantly reduced (P <.008) after instillation of ketotifen. CONCLUSIONS: Ketotifen 0.025% eye drops were safe and statistically effective in preventing ocular itching, injection, and other signs and symptoms of allergic conjunctivitis at 15 minutes, 6 hours, and 8 hours after a single dose and at 8 hours after the final dose of a 4-week twice daily regimen.

Adult↗

PubMed1997

Measuring the minimum clinically important difference in BPH outcome measures.

PURPOSE: To determine the minimum clinically important difference with respect to the different outcome measures used in benign prostatic hyperplasia (BPH) research. MATERIALS AND METHODS: Forty-two patients diagnosed with symptomatic BPH were prospectively recruited from community urology clinics. Patients were asked at follow-up visits to rate their improvement using a self-administrated questionnaire. The improvement score was then compared to the changes from baseline in each of the outcome measures. RESULTS: Maximum and mean flow-rates did not correlate significantly with the patient's improvement measure. The Boyarsky score correlated best with the patient's grading of overall improvement (R=.507, p<.001). The mean change in Boyarsky symptom score for patients with a small improvement was 3.23 (sd=3.52).

Journal Article↗