Biomedical subjects

Keith A Wesnes

Publications and source records attributed to Keith A Wesnes.

21 records · Page 2Linked to original sources

PubMed2002

Safety, pharmacokinetics, and effects on cognitive function of multiple doses of GTS-21 in healthy, male volunteers.

This study was designed to determine the safety, tolerability, pharmacokinetics and effects on cognitive function of GTS-21 in healthy, male volunteers. A total of 18 subjects were randomized to GTS-21 (25, 75 and 150 mg) or placebo administered three times daily (first 4 days, once on Day 5) for three, 5-day sessions. GTS-21 was well tolerated up to doses of 450 mg/day, with no clinically significant safety findings. C(max) and the area under the plasma concentration of GTS-21 and the metabolite 4-OH-GTS-21 increased in a dose-related fashion; although considerable intersubject variability occurred, it decreased with continued dosing. GTS-21 showed statistically significant enhancement of three measures of cognitive function (attention, working memory, episodic secondary memory) compared to placebo. A relationship between exposure to GTS-21 and the magnitude of the cognitive response was apparent, with maximal effect approached for doses between 75 and 150 mg three times a day. These data indicate that GTS-21 may represent a novel treatment for dementia.

Adolescent↗

PubMed2002

Basal activity of the HPA axis and cognitive function in anorexia nervosa.

Elevated cortisol and cognitive impairments have been described in anorexia nervosa, but the relationship between these two variables has not been adequately explored. We profiled the pattern and extent of the cognitive impairment in anorexia nervosa and determined how this related to cortisol secretion. Twenty patients with anorexia nervosa and a matched control group completed a computerized cognitive assessment battery. Diurnal cortisol secretion was measured by serial saliva sampling. Patients were significantly impaired on tasks of attention, long-term memory and working memory. Both groups showed the expected diurnal variation in cortisol production, but no evidence was found for patient cortisol hypersecretion. No correlation was found between cortisol secretion and any of the cognitive task measures. These data suggest that at least some of the cognitive impairments seen in anorexia nervosa are attributable to something other than a basal increase in cortisol secretion. The limitations of cortisol as an indicator of HPA axis activity are discussed.

Adult↗

PubMed2002

Hepatitis C and cognitive impairment in a cohort of patients with mild liver disease.

Patients with chronic hepatitis C virus (HCV) infection frequently report fatigue, lassitude, depression, and a perceived inability to function effectively. Several studies have shown that patients exhibit low quality-of-life scores that are independent of disease severity. We therefore considered whether HCV infection has a direct effect on the central nervous system, resulting in cognitive and cerebral metabolite abnormalities. Twenty-seven viremic patients with biopsy-proven mild hepatitis due to HCV and 16 patients with cleared HCV were tested with a computer-based cognitive assessment battery and also completed depression, fatigue, and quality-of-life questionnaires. The HCV-infected patients were impaired on more cognitive tasks than the HCV-cleared group (mean [SD]: HCV-infected, 2.15 [1.56]; HCV-cleared, 1.06 [1.24]; P =.02). A factor analysis showed impairments in power of concentration and speed of working memory, independent of a history of intravenous drug usage (IVDU), depression, fatigue, or symptom severity. A subgroup of 17 HCV-infected patients also underwent cerebral proton magnetic resonance spectroscopy (1H MRS). The choline/creatine ratio was elevated in the basal ganglia and white matter in this group. Patients who were impaired on 2 or more tasks in the battery had a higher mean choline/creatine ratio compared with the unimpaired patients. In conclusion, these preliminary results demonstrate cognitive impairment that is unaccounted for by depression, fatigue, or a history of IVDU in patients with histologically mild HCV infection. The findings on MRS suggest that a biological cause underlies this abnormality.

Adult↗