21 research outputs found

    Differential Regulation of Tyrosinase Activity in Skin of White and Black Individuals In Vivo by Topical Retinoic Acid

    Get PDF
    Tyrosinase activity is a key determinant of melanin production in skin. Because retinoic acid regulates tyrosinase activity in melanoma cells, we analyzed modulation of pigmentation in vivo by retinoic acid. Black and white subjects were either not treated, or treated topically for 4 d under occlusion with vehicle, retinoic acid (0.1%), or the irritant sodium lauryl sulfate (2%). In untreated skin, tyrosinase activity and melanin content were significantly greater (2.3 times, and 3.2 times, respectively) in blacks versus whites. Four days of treatment with topical retinoic acid did not alter tyrosinase activity or melanin content in black skin. In contrast, retinoic acid treatment significantly induced (2.7 times, n = 8) tyrosinase activity, compared to vehicle treatment, in white skin. Melanin content, however, remained unchanged at 4 d. In separate experiments, tyrosinase activity in white subjects (n = 25) was increased 16% (p = 0.01) in sodium lauryl sulfate – treated skin, and 77% (p = 0.0005) in retinoic acid – treated skin, compared to vehicle-treated skin. The effect of retinoic acid on tyrosinase activity could be differentiated from non-specific irritation, because tyrosinase activity in retinoic acid – treated skin was significantly greater (52%, p = 0.004) than sodium lauryl sulfate-treated skin. Similar results were obtained with the dihydroxyphenylalanine reaction done on vehicle, sodium lauryl sulfate-, and retinoic acid – treated white skin. Northern analysis (n = 6) and semi-quantitative polymerase chain reaction (n = 6) demonstrated that retinoic acid treatment did not alter tyrosinase mRNA levels in white skin. Western analysis revealed that induction of tyrosinase activity by retinoic acid also was not associated with increased tyrosinase protein content (n = 9), indicating that regulation of tyrosinase activity by retinoic acid occurs through a post-translational mechanism. These data demonstrate that low tyrosinase activity in white skin in vivio is retinoic acid inducible and high tyrosinase activity in black skin in vivo is neither further induced nor reduced by retinoic aci

    Suitability of external controls for drug evaluation in Duchenne muscular dystrophy

    Get PDF
    OBJECTIVE: To evaluate the suitability of real-world data (RWD) and natural history data (NHD) for use as external controls in drug evaluations for ambulatory Duchenne muscular dystrophy (DMD). METHODS: The consistency of changes in the 6-minute walk distance (Δ6MWD) was assessed across multiple clinical trial placebo arms and sources of NHD/RWD. Six placebo arms reporting 48-week Δ6MWD were identified via literature review and represented 4 sets of inclusion/exclusion criteria (n = 383 patients in total). Five sources of RWD/NHD were contributed by Universitaire Ziekenhuizen Leuven, DMD Italian Group, The Cooperative International Neuromuscular Research Group, ImagingDMD, and the PRO-DMD-01 study (n = 430 patients, in total). Mean Δ6MWD was compared between each placebo arm and RWD/NHD source after subjecting the latter to the inclusion/exclusion criteria of the trial for baseline age, ambulatory function, and steroid use. Baseline covariate adjustment was investigated in a subset of patients with available data. RESULTS: Analyses included ∼1,200 patient-years of follow-up. Differences in mean Δ6MWD between trial placebo arms and RWD/NHD cohorts ranged from -19.4 m (i.e., better outcomes in RWD/NHD) to 19.5 m (i.e., worse outcomes in RWD/NHD) and were not statistically significant before or after covariate adjustment. CONCLUSIONS: We found that Δ6MWD was consistent between placebo arms and RWD/NHD subjected to equivalent inclusion/exclusion criteria. No evidence for systematic bias was detected. These findings are encouraging for the use of RWD/NHD to augment, or possibly replace, placebo controls in DMD trials. Multi-institution collaboration through the Collaborative Trajectory Analysis Project rendered this study feasible

    Improving Community Understanding of Medical Research: Audience Response Technology for Community Consultation for Exception to Informed Consent

    No full text
    Introduction: The Department of Health and Human Services and Food and Drug Administration described guidelines for exception from informed consent (EFIC) research. These guidelines require community consultation (CC) events, which allow members of the community to understand the study, provide feedback and give advice. A real-time gauge of audience understanding would allow the speaker to modify the discussion. The objective of the study is to describe the use of audience response survey (ARS) technology in EFIC CCs. Methods: As part of the Rapid Anticonvulsant Medication Prior to Arrival Trial (RAMPART), 13 CC events were conducted. We prepared a PowerPoint™ presentation with 4 embedded ARS questions,according to specific IRB guidelines to ensure that the pertinent information would reach our targeted audience. During 6 CCs, an ARS was used to gauge audience comprehension. Participants completed paper surveys regarding their opinion of the study following each CC. Results: The ARS was used with minimal explanation and only one ARS was lost. Greater than 80% of the participants correctly answered 3 of the 4 ARS questions with 61% correctly answering the question regarding EFIC. A total of 105 participants answered the paper survey; 80-90% of the responses to the paper survey were either strongly agree or agree. The average scores on the paper survey in the ARS sites compared to the non-ARS sites were significantly more positive. Conclusion: The use of an audience response system during the community consultation aspects of EFIC is feasible and provides a real-time assessment of audience comprehension of the study and EFIC process. It may improve the community’s opinion and support of the study

    Improving Community Understanding of Medical Research: Audience Response Technology for Community Consultation for Exception to Informed Consent

    No full text
    Introduction: The Department of Health and Human Services and Food and Drug Administration described guidelines for exception from informed consent (EFIC) research. These guidelines require community consultation (CC) events, which allow members of the community to understand the study, provide feedback and give advice. A real-time gauge of audience understanding would allow the speaker to modify the discussion. The objective of the study is to describe the use of audience response survey (ARS) technology in EFIC CCs. Methods: As part of the Rapid Anticonvulsant Medication Prior to Arrival Trial (RAMPART), 13 CC events were conducted. We prepared a PowerPoint™ presentation with 4 embedded ARS questions,according to specific IRB guidelines to ensure that the pertinent information would reach our targeted audience. During 6 CCs, an ARS was used to gauge audience comprehension. Participants completed paper surveys regarding their opinion of the study following each CC. Results: The ARS was used with minimal explanation and only one ARS was lost. Greater than 80% of the participants correctly answered 3 of the 4 ARS questions with 61% correctly answering the question regarding EFIC. A total of 105 participants answered the paper survey; 80-90% of the responses to the paper survey were either strongly agree or agree. The average scores on the paper survey in the ARS sites compared to the non-ARS sites were significantly more positive. Conclusion: The use of an audience response system during the community consultation aspects of EFIC is feasible and provides a real-time assessment of audience comprehension of the study and EFIC process. It may improve the community’s opinion and support of the study

    Improving Understanding of Medical Research: Audience Response Technology for Community Consultation for Exception to Informed Consent

    No full text
    Introduction: The Department of Health and Human Services and Food and Drug Administration described guidelines for exception from informed consent (EFIC) research. These guidelines require community consultation (CC) events, which allow members of the community to understand the study, provide feedback and give advice. A real-time gauge of audience understanding would allow the speaker to modify the discussion. The objective of the study is to describe the use of audience response survey (ARS) technology in EFIC CCs.Methods: As part of the Rapid Anticonvulsant Medication Prior to Arrival Trial (RAMPART), 13 CC events were conducted. We prepared a PowerPoint™ presentation with 4 embedded ARS questions,according to specific IRB guidelines to ensure that the pertinent information would reach our targeted audience. During 6 CCs, an ARS was used to gauge audience comprehension. Participants completed paper surveys regarding their opinion of the study following each CC. Results: The ARS was used with minimal explanation and only one ARS was lost. Greater than 80% of the participants correctly answered 3 of the 4 ARS questions with 61% correctly answering the question regarding EFIC. A total of 105 participants answered the paper survey; 80-90% of the responses to the paper survey were either strongly agree or agree. The average scores on the paper survey in the ARS sites compared to the non-ARS sites were significantly more positive.Conclusion: The use of an audience response system during the community consultation aspects of EFIC is feasible and provides a real-time assessment of audience comprehension of the study and EFIC process. It may improve the community’s opinion and support of the study. [West J Emerg Med. 2014;15(4):414-418.

    A phase IIa double-blind, placebo controlled study of extended-release niacin for stroke recovery

    No full text
    Introduction: In pre-clinical studies, extended-release niacin has been shown to increase neurogenesis, synaptogenesis, and angiogenesis in a rat model of experimental middle cerebral artery (MCA) occlusion. Using this animal model, extended-release niacin has been shown to improve functional outcomes in rats when compared to placebo, beginning 24 hours after experimental stroke. Methods: This was a phase IIa double-blind, randomized, placebo controlled study (Henry Ford Health System funded; clinicaltrials.gov NCT00796887). At a single site (Henry Ford Hospital, Detroit, MI), patients with ischemic stroke 3 to 7 days prior and NIHSS 4-20 were randomized to two doses of oral extended-release niacin (500 mg or 1000 mg daily) or placebo. Primary outcome measures were change in mRS or NIHSS from baseline to Week 24. Results: There were 27 patients enrolled in this study. Ten patients were randomized to extended-release niacin 500 mg, 7 to 1000mg, and 10 to placebo. No significant differences were seen in baseline characteristics of enrolled patients. Significant increases in HDL-C were seen from baseline to 24 weeks among extended-release niacin treated patients (12.5 mg/dL, p=0.035), but not in placebo-treated patients (6.2 mg/dL, p=0.157). Mean improvement in NIHSS from baseline to 24 weeks of treatment was similar for both extended-release niacin and placebo treated patients (6.5 vs. 6.1, p=0.845). No differences were seen in functional outcome (mRS) at 24 weeks between extended-release niacin and placebo treated patients (2.1 vs. 2.0, p=0.860). There were a total of 40 AEs, with 27 in the extended-release niacin group and 10 in the placebo group. For these AEs, no clear interaction with treatment group could be confirmed. Conclusions: Extended-release niacin administered for 24 weeks starting between 3 and 7 days after ischemic stroke demonstrated no improvement in functional outcome as compared to placebo. Extended-release niacin was overall well tolerated. Although this small exploratory study did not identify a signal for potential efficacy, useful sample size estimates were gleaned. Any future clinical investigations may benefit from the collection of additional clinical measures of motor or gait function to differentiate treatment effects
    corecore