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Biomedical subjects

N P Nair

Publications and source records attributed to N P Nair.

At least 19 recordsLinked to original sources
PubMed2001

Differences in symptomatology and diagnostic profile in younger and elderly depressed inpatients.

BACKGROUND: Depression is the most prevalent psychiatric disorder in the elderly and several studies indicate that 10-15% of persons over 65 years suffer from significant depressive symptoms. Despite the high prevalence, most cases of depression in the elderly remain unrecognized and untreated, maybe because of a different pattern of symptoms across age groups. The objective of the study was to compare symptomatology and diagnostic profile between younger and elderly DSM-III and DSM-III-R major depressed inpatients and to advise an appropriate depression scale for the elderly. METHODS: The study covers 461 depressed inpatients evaluated with the Hamilton Depression Scale and the Newcastle 1965 Scale. To find differences between younger and elderly patients, the symptomatology was analyzed stepwise by principal component analyses, latent structure analyses and single item analyses. RESULTS: No clinically significant differences in symptomatology between younger and elderly depressed patients were found. The DSM-IV concept of Major Depression and the ICD-10 criteria for depression was not influenced by patients' age. LIMITATIONS: All patients were hospitalized and mainly endogenously depressed and generalization of the results to other populations should be made with caution. Only pretreatment data was analyzed. CONCLUSIONS: The DSM-IV concept of Major Depression and the ICD-10 criteria for depression can be used without modification for age.

Adult↗
PubMed1999

Alzheimer's disease may not be a spirochetosis.

It has been reported previously that spirochetes could be one of the causes of Alzheimer's disease (AD). In this study, we have attempted to reproduce these findings by examining fresh blood samples from 22 patients diagnosed with early stage (n = 16) and late stage (n = 6) AD. The patients were participants in a clinical drug trial. Fresh necropsy brain cortical specimens from AD patients (n = 7) were also examined. Spirochetes were observed microscopically in the blood of only one late-stage AD patient. None of the brain tissues showed the presence of spirochetes. Our results suggest that spirochetes are probably not associated with AD.

Aged↗
PubMed1999

Increased cortisol levels and impaired cognition in human aging: implication for depression and dementia in later life.

Perhaps the most prominent feature of human aging is the variability in decline of intellectual processes. Although many research avenues have been used to study the origin of such an increased variability with aging, new studies show that some biological factors may be associated with normal and pathological cognitive aging. One biological parameter that came under scrutiny in the past few years is the hypothalamic-pituitary-adrenal (HPA) axis, an endocrine closed-loop system controlling the secretion of stress hormones (glucocorticoids). In this review, we summarize data obtained in both animals and humans suggesting that cumulative exposure to high levels of glucocorticoids can be particularly detrimental for the aged hippocampus, a brain structure involved in learning and memory in both animals and humans. We then analyze the implication of these data for the study of dementia and depression in later life, two disorders characterized by increased glucocorticoid secretion in a significant proportion of patients. Finally, we suggest various factors that could explain the development of glucocorticoid hypersecretion in later life.

Aging↗
PubMed1998

Cortisol levels during human aging predict hippocampal atrophy and memory deficits.

Elevated glucocorticoid levels produce hippocampal dysfunction and correlate with individual deficits in spatial learning in aged rats. Previously we related persistent cortisol increases to memory impairments in elderly humans studied over five years. Here we demonstrate that aged humans with significant prolonged cortisol elevations showed reduced hippocampal volume and deficits in hippocampus-dependent memory tasks compared to normal-cortisol controls. Moreover, the degree of hippocampal atrophy correlated strongly with both the degree of cortisol elevation over time and current basal cortisol levels. Therefore, basal cortisol elevation may cause hippocampal damage and impair hippocampus-dependent learning and memory in humans.

Aged↗
PubMed1998

Therapeutic equivalence of risperidone given once daily and twice daily in patients with schizophrenia. The Risperidone Study Group.

A study was conducted to determine whether once-daily administration of risperidone was as effective and safe as twice-daily administration. In a double-blind 6-week trial, 211 patients with acute exacerbation according to DSM-III-R criteria were randomly assigned to receive risperidone at 8 mg once daily or 4 mg twice daily. The primary efficacy measure was the treatment response rate, defined as a 20% or greater reduction in total Positive and Negative Syndrome Scale (PANSS) scores. Severity of extrapyramidal symptoms was assessed by the Extrapyramidal Symptom Rating Scale. The percentage of patients who showed a treatment response at endpoint was not significantly different between groups (76%, once-daily; 72%, twice-daily), nor was the median time to first treatment response (14 days, both groups). Significant reductions in PANSS total and subscale scores and PANSS-derived Brief Psychiatric Rating Scale were observed in both groups, with no significant between-group differences. Extrapyramidal Symptom Rating Scale scores did not differ significantly between groups. There were no clinically relevant changes in vital signs, electrocardiograms, or clinical laboratory test results in either group. Gradual dosage titration over the first 3 days of treatment was well-tolerated in both groups. The median trough plasma concentrations of risperidone, 9-hydroxyrisperidone, and risperidone plus 9-hydroxyrisperidone were significantly lower with once-daily than with twice-daily administration; median plasma concentrations measured within the first 8 hours after administration tended to be higher with once-daily administration. These differences did not affect the safety and efficacy of risperidone. Risperidone given once daily at 8 mg is as effective as twice-daily administration of 4 mg in the treatment of acute exacerbations of schizophrenia. Both regimens were equally well-tolerated.

Adolescent↗
PubMed1997

The dexamethasone suppression test and treatment outcome in elderly depressed patients participating in a placebo-controlled multicenter trial involving moclobemide and nortriptyline.

The dexamethasone suppression test (DST) was conducted in 95 elderly DSM-III-R depressed patients randomized for treatment with moclobemide (MOC; 400 mg daily), nortriptyline (NT; 75 mg daily), or placebo (PBO) in a 7-week double-blind multicenter study. Patients were assessed weekly using various clinical scales, including the 17-item Hamilton Depression Rating Scale. The DST was administered at baseline and at the end of treatment. At baseline, no relationship was found between DST status and the various clinical scales used. At the end of treatment, suppressors (DST-) had significantly improved clinical ratings compared to nonsuppressors (DST+), and were mostly found among those treated with NT (71%) as compared to MOC (41%) or PBO (33%) (p < .03). On the other hand, baseline DST measures influenced treatment outcome; DST+ patients had a greater number of treatment responders to NT (48%) than MOC (19%) or PBO (20%) (p < .07). For DST- patients, the situation was reversed: NT, 7%; MOC, 31%. Postdexamethasone cortisol levels were lower in MOC responders (p < .07). An interaction was found between DST and drug-specific response. The DST may be a useful adjunct for predicting and evaluating the outcome of antidepressant therapy.

Aged↗
PubMed1997

The Major Depression Rating Scale (MDS). Inter-rater reliability and validity across different settings in randomized moclobemide trials. Danish University Antidepressant Group.

The Major Depression Rating Scale (MDS) has been derived from the Hamilton Depression Scale and the Melancholia Scale. The MDS contains the nine DSM-IV items for major depression which all have anchoring scores from 0 to 4; hence, the theoretical score range is up to 36. The Major Depression Rating Scale has in this study been psychometrically analysed in randomized moclobemide trials. The results showed that the MDS had higher internal validity than the Hamilton Depression Scale. Thus, the homogeneity of the items was higher; factor analysis identified only one general depression factor (after 4 weeks of treatment explaining more than 50% of the variance). The inter-rater reliability of the two scales was of the same high level. The ability to measure changes (external validity) was tested in randomized clinical trials with moclobemide versus tricyclics (clomipramine and notriptyline) performed in Denmark in the psychiatric setting as well as in the general practice. The results showed that in the psychiatric setting tricyclics were superior to moclobemide with effect sizes ranging between 0.43 and 0.53. The highest effect size was obtained with the Melancholia Scale and the Major Depression Rating Scale, while the Hamilton Depression Scale was below 0.50. In the general practice setting no difference was found between moclobemide and clomipramine. In conclusion, the Major Depression Rating Scale has been found to have a more homogeneous factor structure than the Hamilton Depression Scale, but still with the same level of reliability and external validity. However, studies are needed to standardize the scale, especially in the general practice setting.

Antidepressive Agents↗
PubMed1997

Treatment of Alzheimer's disease with sabeluzole: functional and structural correlates.

Sabeluzole, a new benzothiazole derivative, has been shown to be neurobiologically active preclinically and clinically appears to exert beneficial effects on memory. In this study, sabeluzole (5 or 10 mg twice daily vs. placebo) was investigated in patients with probable Alzheimer's disease over 1 year, with assessments of cognitive performance and structural changes. Cognitive performance was measured using the Alzheimer's Disease Assessment Scale periodically during treatment. Potential structural correlates in the frontal horn, caudate, third ventricle and hippocampal regions were examined by obtaining computerized tomographic (CT) images before and after treatment. Patients receiving sabeluzole evidenced greater stability than did placebo-treated patients in some cognitive measures. CT measures showed no significant changes from baseline, but some weak associations were found between relative preservation of cognitive function and smaller structural declines in the third ventricle and hippocampus. Cognitive outcome measures suggest that sabeluzole may have potential in slowing the cognitive deterioration of Alzheimer's disease. Furthermore, the method used to explore potential benefits on a morphologic level, although negative in this study, could yet have potential.

Aged↗
PubMed1997

Psychogeriatric clinical, electro-encephalographic and autopsy findings.

Demographic, psychiatric, and electro-encephalographic (EEG) data were compared with brain autopsy findings for 73 elderly psychiatric patients. A late onset of depression (60+ years) was more likely than early onset to be accompanied by Alzheimer's disease. There were strong associations between clinical and histopathological indicators of Alzheimer's disease. This was particularly evident for diffuse EEG slowing. Clinical as well as histopathological indicators of Alzheimer's disease were intensely related to EEG features, mainly EEG slowness (positive), reactivity to eye opening (negative) and dominant frequency (negative). Cerebrovascular pathology showed fewer EEG correlations. The results support the usefulness of the clinical electro-encephalogram in patients suspected to have Alzheimer's disease.

Age Factors↗
PubMed1997

Stress-induced declarative memory impairment in healthy elderly subjects: relationship to cortisol reactivity.

A group of 14 healthy elderly subjects was submitted to a nonstressful (attentional task) and a stressful (public speaking task) condition. Declarative (conscious recollection of learned information) and nondeclarative (retrieved information without conscious or explicit access) memory as well as salivary cortisol levels were measured before and after each condition. The results showed that the stressful condition significantly decreased declarative memory performance, whereas the nonstressful condition did not. Nondeclarative memory performance was not affected by either condition. Further analyses separating the subjects into responders and nonresponders in terms of stress-induced cortisol changes revealed a very different pattern of cortisol secretion and declarative memory performance in both populations. We showed that the responders presented increased cortisol levels 60 min before the actual stressor, whereas the nonresponders presented increased cortisol levels 25 min before the actual stressor. Although the responders did not differ from the nonresponders in declarative memory performance before and after the nonstressful condition, they presented a lower declarative memory performance when measured before and after the stressful condition. The early increase in cortisol levels observed in the responder group suggests that the anticipation of the stress, rather than the actual stressor per se, may have played a more significant role in the stress-induced declarative memory deficits observed in this subgroup. Together, these results show that the cortisol response to anticipation of stress and/or to stress in the elderly specifically affects those memory functions that are dependent on hippocampal activity. They also suggest that an altered cortisol responsivity to acute and/or chronic stress, with its detrimental effects on memory, could be an important factor explaining the genesis of memory deficits in aged populations.

Aged↗
PubMed1996

Cardiovascular, neuroendocrine, and monoaminergic responses to psychological stressors: possible differences between remitted panic disorder patients and healthy controls.

Both clinical symptomatology and stress research suggest that panic attacks might be partially attributable to exaggerated psychophysiological responses to environmental stressors. In the present study, we aimed to explicitly test this idea by measuring the physiological responses to a mild psychological stressor in both healthy controls (n = 8) and fully remitted, medication-free panic disorder patients (n = 8). One hour before the stressor, former patients, compared to healthy controls, exhibited higher diastolic blood pressure. From a blood sample taken 30 min before the stressor, patients, compared to controls, had lower paroxetine platelet binding site densities. During the stressor, patients, compared to controls, had greater increases in plasma levels of cortisol. These preliminary findings suggest that remitted panic disorder patients might have disturbed physiological responses to mild psychological stressors. These disturbances might be related to the development of future episodes.

Adult↗
PubMed1996

Comparison of fluvoxamine, imipramine, and placebo in the treatment of outpatients with panic disorder.

Fluvoxamine and imipramine were compared to placebo in an 8-week doubleblind randomized multicentre trial comprising of 148 outpatients between 19 and 57 years of age (mean: 35) with a DSM-III-R diagnosis of Panic Disorder. mean daily dose at endpoint was: fluvoxamine, 171.4 mg; imipramine 164.7 mg. The mean number of panic attacks per week at baseline were 10.9, 14.4 and 6.5 for fluvoxamine, imipramine and placebo, respectively. The intent-to-treat analysis of the change from baseline (difference score) of the number of panic attacks at endpoint revealed: a difference of 3.3 attacks (95% CI: -0.3, 6.8) between fluvoxamine and placebo and a difference of 6.0 attacks (95% CI: 1.5, 10.5) between imipramine and placebo. Treatment was stopped prematurely in 31 (62%) on fluvoxamine, 16 (33%) on imipramine and 29 (58%) on placebo. The number of patients withdrawing due to intolerance was 13 (26%) for fluvoxamine, 10 (21%) for imipramine and 4 (8%) for placebo. The number of patients withdrawing due to lack of efficacy was 10 (20%) for fluvoxamine, 4 (8%) for imipramine and 12 (24%) for placebo. Overall, this study demonstrated that fluvoxamine was not effective in the treatment of panic disorder but did show a strong effect for imipramine. A chance occurrence of significantly fewer number of panic attacks in the placebo group at baseline may limit the conclusions of this study.

Adult↗
PubMed1996

Clinical relevance of serum nortriptyline and 10-hydroxy-nortriptyline measurements in the depressed elderly: a multicenter pharmacokinetic and pharmacodynamic study.

In a recent placebo-controlled multicenter study, 38 patients, ranging in age between 62 and 88 years (median, 71) were treated with nortriptyline (NT) for up to 7 weeks. NT was administered in a divided dose of 75 mg daily and serum NT (se NT), and its 10-hydroxy-metabolites (se OH-NT) were determined at various intervals. Several clinical measures of efficacy, including the 17-item Hamilton Rating Scale for Depression, were evaluated weekly as well as side effects (anticholinergic) and electrocardiogram (ECG) changes. Eighty-one percent of patients had NT levels in the previously defined therapeutic range of 50 to 170 ng/ml, with steady state reached between 1 and 3 weeks. There was little individual variation in drug kinetics and metabolism over the study period. In general se OH-NT levels were not greater than those of se NT. Pharmacodynamic analyses showed that patients with moderate to severe anticholinergic side effects [CSE(+)] had significantly higher NT levels than those with mild or no symptoms [CSE(-)]. Furthermore, repeated-measures ANOVA modeled over time showed a highly significant decrease in clinical measures in both CSE groups of patients and also a highly significant group-time interaction. Higher se OH-NT levels were associated with less anticholinergic side effects. No ECG changes were observed.

Aged↗
PubMed1996

The effect of Yohimbine, an alpha2 adrenergic receptor antagonist, on the growth hormone response to apomorphine in normal subjects.

Yohimbine HCl (16 mg po) administered 30 min before clonidine (CLON) (2 ug/kg infused over 10 min) (N = 5) or apomorphine HCl (Apo) (0.5 mg sc) (N = 10) antagonized the growth hormone (GH) response to CLON but had no effect on the GH response to Apo in normal men. This finding suggests that in humans, alpha2 adrenergic mechanisms do not modulate dopaminergic function, at least not in the hypothalamic-pituitary axis, and that the GH response to Apo is not mediated via an alpha2 adrenergic link.

Adrenergic alpha-Antagonists↗
PubMed1995

Moclobemide and nortriptyline in elderly depressed patients. A randomized, multicentre trial against placebo.

Moclobemide and nortriptyline were compared with placebo in a double-blind randomized multinational (Canada, Denmark and UK) trial comprising 109 patients of > 60 years of age with major depression (DSM-III-R). Patients were randomized to 7 weeks of treatment with doses of 400 mg/day moclobemide, 75 mg/day nortriptyline or placebo. It was necessary to adjust nortriptyline dosage in < 20% of patients to maintain serum levels within the postulated therapeutic window of 50-170 ng/ml. At end of treatment, the remission rates were 23% for moclobemide, 33% for nortriptyline and 11% for placebo. Anticholinergic and orthostatic events occurred more often with patients on nortriptyline than either moclobemide or placebo.

Aged↗