The limits and power of peer review.
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Ethics, Medical↗
Biomedical subjects
Michael Franklin
Publications and source records attributed to Michael Franklin.
Common and unique components of response inhibition revealed by fMRI.
The ability to inhibit inappropriate responses is central to cognitive control, but whether the same brain mechanisms mediate inhibition across different tasks is not known. We present evidence for a common set of frontal and parietal regions engaged in response inhibition across three tasks: a go/no-go task, a flanker task, and a stimulus-response compatibility task. Regions included bilateral anterior insula/frontal operculum and anterior prefrontal, right dorsolateral and premotor, and parietal cortices. Insula activity was positively correlated with interference costs in behavioral performance in each task. Principal components analysis showed a coherent pattern of individual differences in these regions that was also positively correlated with performance in all three tasks. However, correlations among tasks were low, for both brain activity and performance. We suggest that common interference detection and/or resolution mechanisms are engaged across tasks, and that inter-task correlations in behavioral performance are low because they conflate measurements of common mechanisms with measurements of individual biases unique to each task.
Adolescent↗
A comparison of two treatment regimens of ceftriaxone in late Lyme disease.
BACKGROUND: The optimal duration of treatment for patients with late Lyme disease is unresolved. METHODS: In a prospective, open label, randomized, multi-center study, a 14 day course of ceftriaxone was compared to 28 days of therapy. Entry criteria included objective abnormalities compatible with late Lyme disease and serologic reactivity to Borrelia burgdorferi. Randomization took place prior to obtaining serologic results. Clinical response was rated as cure; improvement; failure; or not assessable. RESULTS: Of the 201 patients randomized, 21 patients in the 14 day group and 37 in the 28-day group were excluded from the study for failure to meet serologic criteria. Of those who met serologic criteria, 80 patients received 14 days and 63 received 28 days of ceftriaxone. At time of last evaluation, there were 5 treatment failures in the 14 day group and none in the 28 day group (p = 0.07). Clinical cure rates were 76% for the 14 day group and 70% for the 28 day group (p = NS). Therapy was discontinued due to adverse events for a significantly greater proportion of patients in the 28-day group compared to the 14-day group (p < 0.02). CONCLUSIONS: Ceftriaxone for 14 days eradicated the signs and symptoms of late Lyme disease in the majority of evaluable patients. Although there were more failures in the 14-day group than in the 28-day group, this study did not have the power to determine if a clinical subset of patients may benefit from 28 days of therapy.
Adult↗
Effects of short-term administration of valproate on serotonin-1A and dopamine receptor function in healthy human subjects.
OBJECTIVE: To examine the effects of short-term valproate treatment on human brain serotonin and dopamine function by means of challenge tests with ipsapirone, a partial agonist at 5-HT1A receptors, and apomorphine, a dopamine receptor agonist. DESIGN: Experimental challenge-rechallenge, within-subjects repeated measures, before and at the end of 14 days of treatment with valproate at a dosage of 625 mg/d (reached gradually over the first 5 days). PARTICIPANTS: Eight healthy male volunteers (mean age 38 years) selected for good physical and mental health who were nonsmokers. OUTCOME MEASURES: Pharmacological probes were used to evaluate the effects of valproate. In the ipsapirone challenge, changes in adrenocorticotropic hormone (ACTH), cortisol and body temperature were measured, and in the apomorphine challenge, growth hormone (GH) and prolactin were the dependent variables. RESULTS: Valproate treatment did not significantly alter the ACTH, cortisol or body temperature responses to ipsapirone (20 mg by mouth), which reached equivalent plasma levels at each challenge. Similarly, valproate treatment did not alter the GH or prolactin responses to apomorphine (5 micrograms/kg subcutaneously). CONCLUSIONS: These results suggest that short-term treatment with valproate at a dose of 625 mg/d does not alter hypothalamic or pituitary 5-HT1A or dopamine receptor responses to challenges with ipsapirone and apomorphine, respectively.
Adrenocorticotropic Hormone↗