Biomedical subjects

J P John

Publications and source records attributed to J P John.

9 recordsLinked to original sources

PubMed2006

Sustained attention and executive functions in euthymic young people with bipolar disorder.

BACKGROUND: Persistent neuropsychological impairments have been reported in the euthymic phase of bipolar affective disorder. However, the findings have been confounded by multiple episodes, chronic illness and residual mood symptoms. AIMS: To assess sustained attention and executive functioning in euthymic young people with bipolar I disorder who had had no more than two affective episodes. METHOD: Thirty euthymic patients (with illness duration of less than 5 years and no more than two affective episodes) and 30 matched healthy individuals were assessed for sustained attention and executive functioning. RESULTS: The bipolar group (mean age 22.4 years, s.d.=2.52; duration of illness 20.87 months, s.d.=14.72), showed impairment on tasks of attention and executive functioning. Multivariate logistic regression analysis demonstrated that deficits in executive functioning differentiated cases from controls. There was no correlation between residual depressive symptoms and neuropsychological performance. CONCLUSIONS: Deficits in attention and executive functioning were present in young people who had experienced only a few episodes of bipolar disorder, suggesting that the deficits are possibly trait abnormalities. Whether these deficits worsen with progression of illness needs to be examined in longitudinal studies.

Adult↗

PubMed2001

Neuroendocrine and behavioral responses to mCPP in Obsessive-Compulsive Disorder.

Patients with Obsessive-Compulsive Disorder (OCD) have been shown to demonstrate blunted cortisol and prolactin responses along with an exacerbation of obsessive-compulsive symptoms in response to oral administration of the pharmacological probe, meta-chlorophenylpiperazine (mCPP). In an attempt to replicate these findings, mCPP was administered orally in the dose of 0.5 mg/kg body weight in a randomized double-blind design to 34 OCD patients who were either drug-naive or drug-free for a minimum period of four weeks. The cortisol and prolactin responses were contrasted with those of 18 drug-free healthy subjects. The OCD patients showed significantly blunted cortisol and prolactin responses to mCPP challenge as compared to normal subjects. However, mCPP did not produce any significant exacerbation of obsessive-compulsive symptoms in the patient group. The results are suggestive of a serotonin (5-HT) receptor hyporesponsivity in the HPA axis. Even though previous studies indicate a hyperresponsivity of the 5-HT receptor system in the orbitofrontal-striatal-pallido-thalamo-cortical pathway as shown by significant symptom worsening following serotonergic challenge, the present study failed to replicate those results. 5-HT receptor hyporesponsivity in the HPA axis may be considered as a biological "trait marker" of OCD, and may not be directly involved in the mediation of symptomatology of the disorder.

Administration, Oral↗

PubMed1995

Assessment of changes in both weight and frequency of use of medications for the treatment of gastrointestinal symptoms among clozapine-treated patients.

Clozapine has an unusual profile of adverse effects; among them, gastrointestinal (GI) side effects are important management concerns. The charts of patients in a state hospital who received clozapine for at least 3 months were reviewed. We compared the pre- and post-clozapine weights and changes in frequency and intensity of use of drugs prescribed for gastrointestinal symptoms for each subject (n = 99). There were statistically significant increases in the use of antacids (p < 0.02) and both bulk and non-bulk laxatives (p < 0.05, p < 0.03). Seventy-three percent of patients gained weight, of whom 27% gained over 10% body weight. This study confirms clozapine's association with weight gain, constipation, and upper GI symptoms. The literature concerning weight gain, and the mechanisms underlying GI adverse effects were reviewed.

Adult↗

PubMed1978

Influence of pentifylline on brain metabolism of normal and anoxic rats.

1-Hexyl-3,7-dimethyl-xanthine (pentifylline) increases significantly (1 h after oral administration of 25 mg/kg) the adenosine triphosphate and the total adenine nucleotide pool in the brain of normal rats and rats subjected to nitrogen breathing for 30 s. An increase in glycogen and in pyridine nucelotides (NAD+ + NADH2) were also noted. The results indicate that pentifylline shows a tendency toward normalizing or "economizing" the brain metabolism.

Adenine Nucleotides↗

PubMed1974