Biomedical subjects

A Honig

Publications and source records attributed to A Honig.

At least 37 records · Page 2Linked to original sources

PubMed2002

Effects of acute tryptophan depletion on mood and cortisol release in first-degree relatives of type I and type II bipolar patients and healthy matched controls.

Biological vulnerability for bipolar disorders (BD) in relatives of BD patients has not as yet been established. Serotonergic vulnerability was studied, using acute tryptophan depletion (ATD), in healthy first-degree relatives of BD patients and healthy controls. The effects of ATD on mood and cortisol release in 30 healthy adult, lifetime symptom free, unaffected first-degree relatives of BD patients (Family History; FH) were compared with effects in 15 healthy matched controls in a placebo-controlled, double-blind, crossover design. During ATD and placebo, salivary cortisol response was also assessed during a stress-inducing speech task (SIST). First-degree relatives of type II BD patients (FH II) showed an elevation of mood, whereas control subjects and relatives of type I BD patients (FH I) showed a lowering of mood after ATD. ATD was followed by a decrease in cortisol level in both FH subgroups, but not in the controls. The results suggest serotonergic vulnerability that affected mood in FH II subjects and cortisol release in both FH I and FH II subjects.

Adult↗

PubMed2002

Cognition following acute tryptophan depletion: difference between first-degree relatives of bipolar disorder patients and matched healthy control volunteers.

BACKGROUND: Serotonergic circuits have been proposed to mediate cognitive processes, particularly learning and memory. Cognitive impairment is often seen in bipolar disorders in relation to a possible lowered serotonergic turnover. METHODS: We investigated the effects of acute tryptophan depletion (ATD) on cognitive performance in healthy first-degree relatives of bipolar patients (FH) (N= 30) and matched controls (N= 15) in a placebo-controlled, double-blind cross-over design. Performance on planning, memory and attention tasks were assessed at baseline and 5 h after ATD. RESULTS: Following ATD, speed of information processing on the planning task was impaired in the FH group but not in the control group. FH subjects with a bipolar disorder type I relative (FH I) showed impairments in planning and memory, independent of ATD. In all subjects, ATD impaired long-term memory performance and speed of information processing. ATD did not affect short-term memory and focused and divided attention. CONCLUSIONS: The results suggest serotonergic vulnerability affecting frontal lobe areas in FH subjects, indicated by impaired planning. Biological vulnerability in FH I subjects is reflected in impaired planning and memory performance. In conclusion, the cognitive dysfunctions in FH subjects indicate an endophenotype constituting a possible biological marker in bipolar psychopathology. Serotonin appears to be involved in speed of information processing, verbal and visual memory and learning processes.

Administration, Oral↗

PubMed2002

Serotonergic dysregulation in bipolar disorders: a literature review of serotonergic challenge studies.

OBJECTIVES: Serotonin (5-hydroxytryptamine; 5-HT) and endocrine abnormalities have been repeatedly reported in bipolar disorders (BD). Useful methods to investigate 5-HT responsivity, and the interaction with neuroendocrine functioning, are provided by acute 5-HT challenge and depletion paradigms. In this review 5-HT challenges are limited to paradigms that stimulate 5-HT activity in BD. METHODS: Literature was searched for in electronic libraries: MEDLINE and PSYCHLIT, period 1966-2001. Papers describing effects of an acute 5-HT challenge on neuroendocrine functioning in BD patients were selected. RESULTS: Review of the literature revealed 15 studies: five papers described the effects of 5-HT challenges in manic BD patients, four papers in euthymic BD and seven in depressed BD patients. The reviewed 5-HT challenge paradigms are acute administration of oral and intravenous (i.v.) dosage of d,l-fenfluramine, tryptophan, 5-hydroxytryptophan, ipsapirone and buspirone. There were no papers which investigated neuroendocrine effects of m-chlorophenylpiperazine, clomipramine and citalopram in BD patients and were therefore not reviewed. CONCLUSIONS: The literature on 5-HT challenge procedures in BD shows evidence for a blunted prolactin (PRL) in mania and depression as well as a blunted cortisol in euthymic BD patients. This suggests that in both mania and depression similar changes in the 5-HT system are involved. It is speculated that blunting of cortisol responses in euthymic BD patients may be a result of chronically altered 5-HT functioning, whereas changes in PRL release following 5-HT challenges reflect more state-dependent changes in 5-HT activity. The 5-HT responsivity in BD patients has also been associated with pharmacological treatment, suicidal behaviour, weight loss and age. Recommendations for future research are given.

Bipolar Disorder↗

PubMed2002

Intercomparison exercise of the PTB, BfS, MPA and PSI calibration facilities for radon gas concentration.

The traceability chain of one national reference laboratory (PTB) and three accredited radon calibration laboratories (BfS MPA and PSI) to internationally acknowledged radon gas standards is specified. As an additional tool for quality assurance, interchange of an electronic radon measuring instrument was used as a means for a relative comparison of the radon gas reference atmospheres. The instrument was exposed to radon gas activity concentrations between 500 Bq.m(-3) and 15 kBq.m(-3). Measured sensitivities of the participants agree well inside the range of specified calibration uncertainties.

Calibration↗

PubMed2002

Reduced tolerance of simulated altitude (4200 m) in young men with borderline hypertension.

BACKGROUND: Primary hypertensives who are acutely exposed to hypoxic hypoxia show an enhanced reactivity of arterial chemoreceptors as well as an exaggerated response of the sympathetic nervous system. Since these phenomena could influence their ability to tolerate sustained hypoxic hypoxia, this study was performed to determine whether persons predisposed to hypertension have a normal tolerance of simulated high altitude. METHODS: Subjects were 18 young men with a family history of hypertension (sons of hypertensives, SOHT) whose BP values were in the upper normal or borderline hypertensive range. Controls were 15 young men without parental hypertension (sons of normotensives, SONT) who had normal BP values. Each subject underwent both a control and an altitude experiment. The latter consisted of an 8-h exposure to hypobaric hypoxia (equivalent to 4200 m) while resting supine in an altitude chamber. Fluids were administered by mouth and by intravenous line to produce sustained diuresis. Variables measured included heart rate, BP, respiratory rate, O2 saturation, urine flow rate, and sodium excretion. RESULTS: All subjects tolerated the control experiment and all SONT also completed altitude exposure. However, 8 of 18 SOHT developed antidiuresis and had to leave the chamber early due to symptoms of mild acute mountain sickness. Compared with SONT, SOHT exhibited more stable cardiorespiratory parameters at altitude. CONCLUSIONS: The data support the hypothesis that borderline hypertensives have stronger cardiorespiratory responses to altitude than controls, a response that is compatible with higher excitability of their arterial chemoreceptors. However, their altitude tolerance is reduced even at rest, probably because of the renal effects of an exaggerated response in the sympathetic nervous system.

Adaptation, Physiological↗

PubMed2001

The RNA binding protein YB-1 binds A/C-rich exon enhancers and stimulates splicing of the CD44 alternative exon v4.

Exon enhancers are accessory pre-mRNA splicing signals that stimulate exon splicing. One class of proteins, the serine-arginine-rich (SR) proteins, have been demonstrated to bind enhancers and activate splicing. Here we report that A/C-rich exon enhancers (ACE elements) are recognized by the human YB-1 protein, a non-SR protein. Sequence-specific binding of YB-1 was observed both to an ACE derived from an in vivo iterative selection protocol and to ACE elements in an alternative exon (v4) from the human CD44 gene. The ACE element that was the predominant YB-1 binding site in CD44 exon v4 was required for maximal in vivo splicing and in vitro spliceosome assembly. Expression of wild-type YB-1 increased inclusion of exon v4, whereas a truncated form of YB-1 did not. Stimulation of exon v4 inclusion by wild-type YB-1 required the ACE necessary for YB-1 binding in vitro, suggesting that YB-1 stimulated exon inclusion in vivo by binding to an exonic ACE element. These observations identify a protein in addition to SR proteins that participates in the recognition of exon enhancers.

Alternative Splicing↗

PubMed2001

Depression and cardiac mortality: results from a community-based longitudinal study.

BACKGROUND: Depression may be a potential risk factor for subsequent cardiac death. The impact of depression on cardiac mortality has been suggested to depend on cardiac disease status, and to be stronger among cardiac patients. This study examined and compared the effect of depression on cardiac mortality in community-dwelling persons with and without cardiac disease. METHODS: A cohort of 2847 men and women aged 55 to 85 years was evaluated for 4 years. Major depression was defined according to psychiatric DSM-III criteria. Minor depression was defined by Center for Epidemiologic Studies-Depression Scale scores of 16 or higher. Effects of minor and major depression on cardiac mortality were examined separately in 450 subjects with a diagnosis of cardiac disease and in 2397 subjects without cardiac disease after adjusting for demographics, smoking, alcohol use, blood pressure, body mass index, and comorbidity. RESULTS: Compared with nondepressed cardiac patients, the relative risk of subsequent cardiac mortality was 1.6 (95% confidence interval [CI], 1.0-2.7) for cardiac patients with minor depression and 3.0 (95% CI, 1.1-7.8) for cardiac patients with major depression, after adjustment for confounding variables. Among subjects without cardiac disease at baseline, similar increased cardiac mortality risks were found for minor depression (1.5 [95% CI, 0.9-2.6]) and major depression (3.9 [95% CI, 1.4-10.9]). CONCLUSION: Depression increases the risk for cardiac mortality in subjects with and without cardiac disease at baseline. The excess cardiac mortality risk was more than twice as high for major depression as for minor depression.

Age Factors↗

PubMed2001

Depression and myocardial infarction: relationship between heart and mind.

There is a relationship between depression and Myocardial Infarction (MI) as higher levels of depression and severe depression (major vs minor) are associated with higher morbidity and mortality due to cardiac events, which are mainly caused by arrhythmia. Second, severity of MI is not or even inversely related to development of depression. Depression post-MI goes often unrecognized as only 10% of depressed MI patients are diagnosed as such. This underestimation of depression is attributed to its atypical profile, tendency of physicians to interpret depressive symptoms as a transient and 'natural' reaction to a life-threatening event, and the scarce knowledge of risk factors associated with development of post-MI depression. During the first 18 months following MI major depression occurs in 15-30% of patients. Depression should be assessed in an early stage as depression has the highest prevalence in hospital and in the first 6 months post-MI. Risk factors for developing post-MI depression include complications during hospitalization, prescription of benzodiazepines during hospitalisation, previous history of depression, and not being able to stop smoking. Selective Serotonin Reuptake Inhibitors (SSRIs) appear to be first choice treatment in post-MI depression. As yet there is no information on the efficacy and safety of Serotonin and Noradrenalin Reuptake Inhibitors (SNRIs).

Depressive Disorder↗

PubMed2001

Research into the specificity of depression after stroke: a review on an unresolved issue.

Iwo decades of research have failed to generate consistent insight into the specificity of poststroke depression (PSD). This is, at least in part, caused by methodological difficulties. Differences in symptom profile between PSD and depression with no or another medical cause were described, but no specific and unequivocal clinical picture has been established so far. Prevalence rates of PSD varied largely between studies. In community based studies using standardised diagnostic instruments for depression, relatively low prevalence rates were reported compared to inpatient or rehabilitation studies. PSD occurs most frequently in the first few months after stroke, while a new incidence peak may occur 2-3 years after stroke. Two systematic reviews on the relation between lesion location and depression did not support the claim that left hemisphere lesions are a risk factor for PSD. A new concept of vascular depression has been proposed, which relates depression in the elderly to acute or chronic damage to the cerebral vascular system. Future efforts should aim at increasing the uniformity of study designs, assessment tools should be further improved for use in cognitively impaired patients and appropriate control groups should be defined to study the characteristic features of PSD.

Depressive Disorder↗

PubMed2001

Usefulness of the retrospective Life-Chart method manual in outpatients with a mood disorder: a feasibility study.

The aim of this project was to evaluate whether the Life-Chart Manual (LCM) can help patients to complete their own Life-Chart (LC). All patients were recruited via the outpatient department for affective disorders of the Academic Hospital Maastricht. They were diagnosed as having a unipolar or bipolar disorder according to DSM-IV criteria. Following a short briefing interview, these patients were asked to complete their own LC for the last 6 years, using the manual. Seventy-four patients were selected, of whom 44 were willing to participate in the study. About half of these patients (n=20) completed the LC adequately (60-80% of the items completed) with only minimal professional help. Although patients found it difficult to complete the LC, most considered it worthwhile. The LCM is an adequate tool to help patients with a major affective disorder to complete their own LC with minimal professional assistance.

Adult↗

PubMed2001

Clinical correlates of depression following myocardial infarction.

OBJECTIVE: Post-MI depression increases mortality, especially in the first 18 months after MI. Identifying patients at risk for post-MI depression is therefore important. In the present study we investigated possible correlates for post-MI depression on an a priori basis. METHOD: Based on the literature, four clinically easily attainable variables were selected as possible correlates for post-MI depression. These were prescription of benzodiazepines during acute hospitalization, cardiac complications during acute hospitalization, history of depression, and not being able to stop smoking within six months after MI. A consecutive cohort of 173 first-MI patients was screened with the SCL-90 depression scale and DSM-III-R criteria for major depression. Of this cohort 35 depressed patients were compared with 35 non-depressed post-MI patients, matched for gender, age, and severity of MI. RESULTS: In univariate analyses, complications during hospitalisation (OR = 2.14; CI = 0.89-5.14), prescription of benzodiazepines (OR = 3.67; CI = 1.11-12.1), history of depression (OR = 3.0; CI = 0.87-10.4), and not being able to stop smoking (OR = 4.5; CI = 1.11-18.2) were clinical correlates for post-MI depression. Multivariate analyses showed that none of these variables were independent of the others in predicting depression. CONCLUSIONS: A number of easily measurable patient characteristics identify those MI-patients at risk of post-MI depression. Further investigations should focus on the predictive value of these factors in relation to post-MI depression.

Adult↗

PubMed2000

[Depression following a heart infarct and increased risk of death].

Depression is an important risk factor for cardiac mortality, especially in the first 18 months after a myocardial infarction. Listlessness and a hostile mood are the specific features of the depression following myocardial infarction, rather than depressed mood. Also, depressed post infarction patients are more often re-admitted for cardiac reasons and their work resumption is delayed. There are indications that depression and myocardial infarction have an aetiological relationship via the behavior and emotions that are a risk factor for the development of both disorders. Depression and myocardial infarction are both stress-related disorders. A pathological stress reaction is seen in both conditions and triggers immune activation, enhanced blood cortisol levels, disturbance of serotonin metabolism and increased sympathetic activation. Early detection of post-infarction depression and treatment with a selective serotonin reuptake inhibitor (SSRI) is advised. SSRIs have been shown to be efficacious and safe in this patient population. Tricyclic antidepressants (TCAs) are relatively contra-indicated due to their cardiac side effects. As yet, no therapeutic effect of antidepressants, in the sense of decreased cardiac mortality or a decrease in fatal rhythm disorders, has been demonstrated.

Antidepressive Agents, Tricyclic↗

PubMed2000

[Panic disorder in patients with chest pain and palpitations: an often unrecognized relationship].

The prevalence of panic disorder in patients who present with chest pain or palpitations to a First Heart Aid setting varies in the literature between 0%-59%. In a high percentage of cases, panic disorder is not recognized by the cardiologist in patients who present initially with chest pain or palpitations. Patients with panic disorder have a large and ongoing medical consumption. A selective serotonin reuptake inhibitor and/or cognitive therapy appear to be good treatment of panic disorder in patients who present initially with chest pain or palpitations. A CO2 challenge test elicits the symptoms in patients with panic disorder with high sensitivity and specificity but this test has not been validated in patients who present initially with chest pain or palpitations and in whom the diagnosis 'panic disorder' is not yet established.

Arrhythmias, Cardiac↗

PubMed2000

[Panic disorder, chest pain and palpitations: a pilot study of a Dutch First Heart Aid].

OBJECTIVE: To determine how many patients, presenting to a First Heart Aid (FHA) with chest pain or palpitations without a cardiac origin for their complaints, have a panic disorder and/or depression. DESIGN: Prospective and questionnaire investigation. METHOD: In 3 months (November 1st 1998-January 31st 1999) all patients presenting to the FHA of the University Hospital Maastricht, the Netherlands, and who were not admitted, were screened for the presence of psychopathology by means of a questionnaire, the 'Hospital anxiety and depression scale' (HADS). Patients scoring above 8 on the HADS with no cardiac cause for their initial complaint were interviewed using the 'Mini international neuropsychiatric interview' (MINI) to determine whether there was a panic disorder and/or a depressive episode. RESULTS: Of a total of 621 patients 251 met the inclusion criteria; 134 (53%) gave informed consent (72 (54%) men and 62 (46%) women, with a mean age of 55.9 (SD: 13.2; range: 23-84)). Of the 134, 77 had a HADS score > or = 8; in 59 (30 men; 29 women) the MINI was carried out; in 49 (83%) panic disorder (n = 45) or depression (n = 4) was diagnosed. In 7/45 the cardiologist had diagnosed a psychiatric disorder ('Hyperventilation'). CONCLUSION: In 83% of the patients who visited the Maastricht FHA with cardiac complaints but without a cardiac origin and who had a HADS score > or = 8, panic disorder and/or depression was diagnosed.

Adult↗

PubMed2000

Measurement of radon and radon progenies at the German radon reference chamber.

The activity concentration of radon in the environment can vary over five orders of magnitude. Radon and its progenies thus concern all people involved in radiation protection as well as in low-level experiments. In the German radon reference chamber at the PTB, radon and its progenies are measured with different systems for alpha- and gamma-spectrometry with the full set of environmental parameters, e.g. temperature, humidity and aerosol concentration being controlled. Control of air pressure is also possible by use of an extention chamber. The sampling and measuring technique for radon and its short-lived progenies at the German radon reference chamber are the basis for fundamental studies with regard to the understanding of the equilibrium factor and the unattached fraction of progenies. The facility also serves for the calibration of radon progeny detectors.

Environmental Monitoring↗

PubMed2000

The relationship between depressive and vital exhaustion symptomatology post-myocardial infarction.

OBJECTIVE: Many peri-myocardial infarction patients experience decreased wellbeing, which is either conceptualized as depression or as vital exhaustion. The objective of the present study is to investigate whether or not depression and vital exhaustion are separate entities. It was hypothesized that, if depression and vital exhaustion are separate phenomena, the correlation between two depression questionnaires would be higher than those between either of the two depression questionnaires and a vital exhaustion questionnaire. METHOD: Subjects were 143 patients who had recently experienced a first acute myocardial infarction (MI). At 1, 3, 6 and 12 months post-MI, patients completed two self-report depression questionnaires (the Zung-SDS and the Depression scale of the SCL-90), and a vital exhaustion questionnaire (the Maastricht Questionnaire). Correlation coefficients were calculated for the two depression questionnaires and the vital exhaustion questionnaire. Furthermore, an exploratory principal component analysis was performed on the combined items of the three questionnaires. RESULTS: Strong and virtually identical correlations were found between the three measures at all four time-points. A one-factor model was the best fit in the exploratory principal component analysis. CONCLUSION: The present results do not support the hypothesized separate conceptual identity of depression and vital exhaustion.

Adult↗

PubMed2000

Cognitive performance in relation to MRI temporal lobe volume in schizophrenic patients and healthy control subjects.

The aim of this study was to identify whether specific deficits in cognitive processing are present in schizophrenia and whether these are related to the volume of temporal and limbic structures. Twenty-seven schizophrenic outpatients were compared with 19 matched control subjects. Compared with control subjects, patients performed complex tasks disproportionately worse than they performed simple tasks. No group differences were found with regard to temporal and limbic volume. Volume of the parahippocampal gyrus was correlated with cognitive performance. The findings are interpreted as evidence for a dysfunction in the maintenance of task-relevant information and the inhibition of irrelevant information.

Adult↗

PubMed2000

Cognitive dysfunctions and white matter lesions in patients with bipolar disorder in remission.

OBJECTIVE: To compare cognitive functioning in relation to white matter lesions in bipolar disorder in remission and schizophrenia. METHOD: Cognitive performance and the occurrence of white matter lesions on MRI images of the brain were assessed in 22 patients with bipolar disorder in remission, 22 patients with schizophrenia and 22 healthy volunteers. RESULTS: Performance of tests of memory, speed and cognitive flexibility was significantly impaired in both patient groups. The frequency of white matter lesions did not differ significantly between the three groups. No differences in cognitive performance were found between patients with white matter lesions and patients without such lesions. CONCLUSION: White matter lesions apparently do not underlie cognitive deficits that are found in patients with bipolar disorder in remission and in patients with schizophrenia.

Bipolar Disorder↗