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Biomedical subjects

I R Katz

Publications and source records attributed to I R Katz.

At least 19 recordsLinked to original sources
PubMed1992

Geriatric psychopathology: an American perspective on a selected agenda for research.

The authors present an overview of research questions related to psychopathology in elderly patients. Specific research questions in the areas of organic mental disorders, affective disorders, personality disorders, anxiety disorders, psychotic disorders, and substance abuse are presented. Clinical investigators are encouraged to pursue some of these specific questions in order to facilitate diagnosis and to develop specific effective treatment strategies for psychopathology in older patients.

Aged↗
PubMed1992

Depression and mortality among institutionalized aged.

This study examined the association between depression and mortality among a group of nursing home and congregate apartment residents (initial n = 898) over a 30-month period. Baseline [Time 1 (T1)] and 1-year follow-up [Time 2 (T2)] assessments yielded research-based diagnoses of possible major, minor, or no depression, along with measures of functional disability, cognitive status, and physician-rated health. Event history analyses were used to assess differential mortality as a function of level of depression after T1 and of change in depressive status from T1 to T2. Significant effects for T1 depression at 6, 12, and 18 months after the interview reflected an increased death rate among possible major depressives as compared with other respondents. An effect of change in depressive status from T1 to T2 appeared to be caused by long-term negative effects of T1 depression. Finally, none of the observed associations remained significant when controlled for effects of physical health, functional disability, and cognitive status. Thus, the effects of depression on mortality among this sample appeared to be attributable strictly to the correlation of depression with ill health. However, cautious interpretation is recommended inasmuch as causal paths between depression, ill health, and death remain unclear.

Activities of Daily Living↗
PubMed1992

Incidence of depression in long-term care settings.

A one-year longitudinal study examined incidence and persistence of depression among nursing home and congregate apartment residents. Of 868 persons interviewed at Time 1, 15.7% displayed research-diagnosed possible major depression, and 16.5% displayed minor depressive symptoms. A follow-up interview a year later (T2; n = 448) yielded an incidence rate for possible major depression of 6.6% among persons with only minor or no depression in the previous year. For T1 nondepressives (i.e., excluding minor depressives), the incidence of possible major depression was 5.6%, and of minor depression, 6.3%. More than 40% of T1 possible major depressives showed no remission of symptoms a year later. In contrast, more than half of T1 minor depressives showed no depression at T2; however, another 16.2% appeared at follow-up to suffer possible major depression. Change in depression was associated with cognitive status, functional disability, and physical health. In general, persistence of depression was associated with greater decline, although patterns differed somewhat for the three functional indicators. Clinical and research implications of findings are discussed.

Activities of Daily Living↗
PubMed1992

Alleviation of immunosuppression in vitro by recombinant platelet factor 4.

To elucidate the mechanism by which platelet factor 4 (PF4), a secreted platelet protein, and its C-terminal peptides alleviate suppression of the antibody response in vivo, their immunoregulatory activity was studied in vitro, using cultured spleen cells from BALB/c mice primed with sheep red blood cells (SRBC). When addition of 48 h cultured concanavalin A (Con A) blasts at 5 x 10(5)/ml significantly suppressed the anti-SRBC plaque-forming cell response, suppression was alleviated in 25 of 29 experiments by 0.2 micrograms/ml recombinant (r)PF4 (6.4 nM if rPF4 is a tetramer). The effect of Con A blasts was abolished by cimetidine, a histamine type 2 (H2) antagonist. Dimaprit, an H2 agonist, at 1-2 x 10(-4) M, or splenic T cells that had been incubated for 1 h with dimaprit and washed, also caused significant suppression that was alleviated by 0.2 micrograms/ml rPF4 (n = 8), and by 0.02 micrograms/ml in six of these tests. The C-terminal 13 amino acid peptide of PF4 was active at 0.02-0.2 micrograms/ml (0.01-0.11 microM), but peptides from the middle or N-terminal end of the molecule, or IL-8, which shares structural homology with PF4, were inactive. IL-1 and IL-2 raised control responses without affecting suppression or its alleviation by rPF4. Neutralizing antibody to transforming growth factor beta 1 (TGF-beta 1) did not affect Con A blast-induced suppression and suppression induced by exogenous TGF-beta 1 (0.5 ng/ml) was not counteracted by rPF4. Blocking prostaglandin production with 0.2 or 2 microM indomethacin did not affect suppression significantly but reduced rPF4 activity; prostaglandin D2 restored the effect of rPF4.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Bedside clinical and electrophysiological assessment: assessment of change in vulnerable patients.

Current approaches to the diagnosis of delirium are based upon the recognition of symptoms that emerge in the pathological state. As an alternative, we propose an approach to case identification for research purposes based on the recognition of significant changes in the cognitive or cerebral state of the individual patient. Categorical change can be defined using prediction intervals calculated from repeated measures on a population of medically stable subjects. Data from subjects enrolled in a prospective study of delirium in a long-term care population were utilized to calculate prediction intervals for the Mini-Mental Status Examination and for measures of the electroencephalographic background frequency as obtained with a two-channel microprocessor-based EEG device. Preliminary findings support the validity of this quantitative approach for defining changes in brain state. Future research should evaluate both cognitive and electrophysiological techniques for monitoring vulnerable patients.

Aged↗
PubMed1991

Toxic and metabolic encephalopathies in long-term care patients.

Evaluation of the change in performance on the Blessed Memory Information Concentration Test over a one-year period was used as a probe for the prevalence of reversible cognitive disorders among patients living in a residential care facility. Of 157 patients with cognitive impairment at the initial assessment, 10 (6.4%) improved by 6 points or more, 19 (12.1%) improved by 5 points or more, and 15 (9.6%) had a reduction in the number of errors by 33% or more. Thus, using improvement over time as an indicator, we estimate that 6% to 12% of the elderly patients in our sample had a reversible component to their cognitive impairment at the initial assessment. Retrospective review of medical records identified (one or more) possible causes for impairment at baseline in each of the ten patients who showed the greatest improvement: adverse drug effects in seven patients, depression in two, and metabolic encephalopathies in three.

Aged↗
PubMed1991

Depression and cognitive change among institutionalized aged.

Interrelations between depression (Geriatric Depression Scale) and cognitive impairment (Blessed test) were examined among 201 nursing home and congregate apartment residents in a 2-year, 3-wave study. In structural equations models that controlled autocorrelations and within-occasion correlated residuals, introducing paths from depression to subsequent cognitive status significantly reduced unexplained variance, whereas paths from cognitive status to subsequent depression did not. Subsidiary analyses indicated that the relation of depression to subsequent cognitive status was strongest among persons with borderline (vs. impaired or intact) cognitive status, but only for the first time interval. Discussion addresses explanations for obtained results and implications for monitoring and treating depression among elderly long-term care residents.

Activities of Daily Living↗
PubMed1991

The relation of pain to depression among institutionalized aged.

Nursing home and congregate apartment residents (N = 598) were classified on the basis of a DSM-IIIR symptom checklist as suffering possible major, minor, or no depression; they also completed the Geriatric Depression Scale (GDS) and the Profile of Mood States (POMS). Possible major depressives reported more intense pain and a greater number of localized pain complaints than did minor depressives; nondepressed individuals reported the least intense pain and fewest localized complaints. The effect remained strong even when functional disability and health status were controlled statistically. Both pain intensity and number of localized complaints were correlated with GDS and POMS factor scores, but strength and direction of associations varied with level of depression. Item-by-item examination of localized complaints again indicated that more depressed individuals were more likely to report pain, particularly where physicians had identified a physical problem that might account for the pain. Results are compared with previous research on pain among younger individuals. Implications for treatment of depressed elderly are discussed.

Activities of Daily Living↗
PubMed1990

Pharmacologic treatment of major depression for elderly patients in residential care settings.

A significant drug-placebo difference was found in a double-blind, placebo-controlled study of nortriptyline for treatment of major depression among frail elderly patients living in an institutional setting. This finding confirms the validity of the DSM-III-R diagnosis of major depression and establishes the need for specific psychiatric services for the chronically ill elderly living in nursing homes and congregate housing facilities. The incidence of adverse events requiring early termination of treatment was 34%, demonstrating the vulnerability of these patients and their need for careful monitoring during treatment. High levels of self-care disability and low levels of serum albumin were both associated with decreased therapeutic responses, demonstrating the need for further research on psychopathology in these settings.

Age Factors↗
PubMed1989

Steady state pharmacokinetics of nortriptyline in the frail elderly.

The frail elderly, for whom chronic disease and disability are essentially universal, are at high risk for depression and are specifically vulnerable to the adverse effects of antidepressant medication. There have, however, been few investigations of either the pharmacokinetics or the clinical investigations of either the pharmacokinetics or the clinical response to antidepressants in such patients. We report on the pharmacokinetics of nortriptyline at steady state in a group of 22 patients, average age 84, living within an institutional setting. Comparison of our findings with those previously reported for younger and healthier subjects suggests that there are no clinically significant group differences in nortriptyline kinetics. Plasma levels of nortriptyline and those of both the trans- and cishydroxylated metabolites are linear with daily dose. Mean (and SD) for the parameter (plasma level/dose) was 1.21 (0.63) ng/ml/mg/day for the parent compound, 1.41 (0.86) for the trans metabolite, and 0.30 (0.16) for the cis metabolite. There was no significant correlation across individuals between the accumulation of the parent compound and the metabolites. Based upon these data, the average dose of nortriptyline required to achieve a plasma level of 100 ng/ml is 80 mg/day. Dose requirements, however, vary between individuals by a factor of 20. Plasma levels measured 24 hours after a 25-mg test dose of nortriptyline can allow early identification of slow metabolizers. Twenty-four-hour plasma levels (mean 8.8 ng/ml, SD 3.2) were significantly correlated with steady state levels at 25 mg/day (r = 0.71), steady state levels at 50 mg/day (r = 0.73), and each individual's average (plasma level/dose) (r = 0.57).

Aged↗
PubMed1989

Clinical features of depression in the nursing home.

The prevalence of depression among nursing home residents was estimated by screening a group of residents selected from a random sample on the basis of cognitive status; it ranged from 18-20% for major depression to 27-44% for other dysphoric states. Though individual patients were observed to change over a 6-month period, depression as assessed with the Geriatric Depression Scale was, in general, persistent. Major depression was clinically confirmed in 8 of 10 patients identified at screening. It was characterized by medical disorders that complicated diagnosis and treatment, and by increased mortality relative to the rest of the population.

Aged↗
PubMed1989

Immunoregulatory activity of peptides related to platelet factor 4.

Platelet factor 4 (PF4), a secreted platelet protein, alleviates concanavalin A-induced immunosuppression in mice. We now find that activity also resides in (i) the C-terminal tridecapeptide of PF4 (P13S), (ii) an analog of this in which arginine replaces the lysine residues and in which the last two amino acids are absent, (iii) the C-terminal 18 amino acids of low-affinity platelet factor 4, which is very similar to P13S, and (iv) peptide fragments of P13S that contain only 5-9 amino acids. P13S treated with fluorescamine to derivatize the free amino groups retained immunoregulatory activity but did not bind to heparin-agarose. The N-terminal and middle portions of PF4, polylysine, protamine, and three unrelated peptides were inactive in this assay.

Amino Acid Sequence↗
PubMed1989

Depression among institutionalized aged: assessment and prevalence estimation.

Aged nursing home and congregate apartment residents were screened for symptoms of depression and cognitive impairment. Of 708 survey respondents, 12.4% met DSM-IIIR criteria (33) for major depression; about half this group also displayed significant cognitive deficits. Another 30.5% of the total sample reported less severe but nonetheless marked depressive symptoms. Such "minor" depressive syndromes were much more common among congregate housing than nursing home residents. Possible major depression was more prevalent among newly admitted residents of both housing components. Comparison of cognitively impaired vs intact respondents revealed that the two groups' self-reports of depression were equally internally consistent, and bore equivalent correlations with observer ratings made by interviewers and direct care staff. Checks of medical records of a group of survey nonrespondents (n = 203) indicated that, excepting the extremely demented, the active sample of 708 accurately represents institution residents as a whole. Finally, comparison with clinical diagnoses made by facility psychology and psychiatry department staff indicated good concurrent validity of research screening measures and methods.

Aged↗