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Biomedical subjects

H Agren

Publications and source records attributed to H Agren.

At least 37 records · Page 2Linked to original sources
PubMed2001

Tau and Abeta42 in cerebrospinal fluid from healthy adults 21-93 years of age: establishment of reference values.

BACKGROUND: Tau protein and the 42-amino acid form of beta-amyloid (Abeta42) measured in cerebrospinal fluid (CSF) have been proposed as potential biochemical diagnostic markers for Alzheimer disease. For the introduction of these assays in clinical practice, adequate reference values are of importance. METHODS: CSF samples were obtained from 231 neurologically and psychiatrically healthy individuals, 21-93 years of age, all with a MiniMental State examination score of 28 or above. Standardized ELISAs were used to measure tau and Abeta42 in CSF. Following IFCC recommendations, we used a rank-based method; the 0.90 and 0.10 fractiles were estimated to establish reference values for CSF-tau and CSF-Abeta42, respectively. Putative confounding factors, such as the influence of the passage of proteins from peripheral blood to CSF, influence of dysfunction of the blood-brain barrier, and freezing and thawing of CSF, were investigated. RESULTS: A correlation with age was found for CSF-tau (r = 0.60; P <0.001). Therefore, separate reference values for different age groups were established for CSF-tau: <300 ng/L in the group 21-50 years of age, <450 ng/L in the group 51-70 years of age, and <500 ng/L in the group 71-93 years of age. CSF-Abeta42 did not correlate with age (r = -0.045), and the reference value was set to >500 ng/L. No correlation was found between blood-brain barrier function and CSF-tau or CSF-Abeta42. CONCLUSIONS: These reference values can be applied when using CSF-tau and CSF-Abeta42 in clinical practice.

Adult↗
PubMed2000

No evident neuronal damage after electroconvulsive therapy.

Electroconvulsive therapy (ECT) is regarded as one of the most effective treatments for major depressive disorder but has also been associated with cognitive deficits possibly reflecting brain damage. The aim of this study was therefore to evaluate whether ECT induces cerebral damage as reflected by different biochemical measures. The concentrations in the cerebrospinal fluid (CSF) of three established markers of neuronal/glial degeneration, tau protein (tau), neurofilament (NFL) and S-100 beta protein, were determined in nine patients who fulfilled DSM-IV criteria for major depression. CSF samples were collected before and after a course of six ECT sessions. The CSF/serum (S) albumin ratio reflecting potential blood-brain barrier (BBB) dysfunction was also determined at these time points. The treatment was clinically successful with a significant decline of depressive symptoms in all patients as assessed by the Montgomery-Asberg Rating Scale for Depression. Several patients had signs of BBB dysfunction and/or neuronal damage before the start of treatment. Levels of CSF-tau, CSF-NFL and CSF-S-100 beta levels were not significantly changed by ECT. Also the CSF/S albumin ratio was found to be unchanged after the course of ECT. In conclusion, no biochemical evidence of neuronal/glial damage or BBB dysfunction could be demonstrated following a therapeutic course of ECT.

Adult↗
PubMed2000

Observation of a continuum-continuum interference hole in ultrafast dissociating core-excited molecules.

The femtosecond dissociation of HCl after core excitation has been studied through the resonant Auger decay. The spectra contain contributions from decay occurring at both "molecular" and "atomic" internuclear distances. We have observed a new interference mechanism in these spectra: An atomic spectral line develops into a negative spectral contribution, a "hole," when detuning the excitation energy from the maximum of the Cl2p(-1)sigma(*) resonance. Resonant x-ray scattering theory quantitatively explains this behavior as due to a novel destructive continuum-continuum interference between molecular and atomic contributions to the Auger decay.

Journal Article↗
PubMed2000

Doppler splitting of In-flight auger decay of dissociating oxygen molecules: the localization of delocalized core holes

By exploiting the core-excitation-induced dissociation of O2, we find that the Auger emission exhibits a Doppler-like energy shift. We show this to be a manifestation of localization of the core hole and propose that the problem of core-hole localization versus delocalization in core-hole spectroscopies may be resolved by considering the nature of the measurement.

Journal Article↗
PubMed2000

[When disease insight is halting. II. The neurobiological underpinnings].

This review examines the neurobiological underpinnings of impaired insight and awareness in psychosis. Crucial mainly dopaminergic pathways are discussed in relation to delusions and hallucinations. Thirty percent of psychotic patients with impaired insight will not respond to traditional neuroleptic drug treatment, and the possibility that multifocal brain etiology might underlie such cases is discussed. It is suggested that severe cases of thought process disorder in psychosis may result from such multifocal processes.

Adaptation, Psychological↗
PubMed2000

Reduced brain norepinephrine and dopamine release in treatment-refractory depressive illness: evidence in support of the catecholamine hypothesis of mood disorders.

BACKGROUND: The etiology of depressive illness has been linked with brain monoaminergic neuronal dysfunction, yet the development of sensitive markers of endogenous depression has proven difficult. METHODS: Using catheters placed in an internal jugular vein, we estimated the release of brain monoamine neurotransmitters in 19 healthy volunteers and in 9 patients with nonbipolar depressive illness refractory to medication at rest and following intravenous desipramine hydrochloride. Venoarterial plasma concentration gradients were used to quantify the amount of neurotransmitters stemming from the brain. Cerebral oxidative metabolism was assessed concurrently from measurements of oxygen and carbon dioxide gas exchange via the process of regional indirect calorimetry. RESULTS: The brains of these patients exhibited reduced venoarterial norepinephrine (4.0 +/- 2.7 nmol/L vs 0.7 +/- 1.3 nmol/L) and homovanillic acid concentration gradients (8.3 +/- 7.8 nmol/L vs 3.1 +/- 1.9 nmol/L), and used an energy source other than glucose. Internal jugular 5-hydroxyindoleacetic acid concentration gradients were not reduced in the patients with depressive illness. While both the reduction in norepinephrine turnover and the defect in cerebral metabolism were normalized following pharmacological blockade of the norepinephrine transporter with desipramine, paradoxically it was the brain's turnover of dopamine that bore a significant relation to the patients' clinical status (r(s) = 0.79, P =.02). The positive nature of this relationship remains difficult to reconcile. CONCLUSIONS: In accordance with the monoamine hypothesis, a deficit in brain norepinephrine and dopamine exists in patients with depressive illness. Moreover, the brains of these patients use an energy source other than glucose, a situation that is normalized following the acute pharmacological blockade of the norepinephrine transporter with the tricyclic antidepressant, desipramine.

Adult↗
PubMed2000

Sertraline versus paroxetine in major depression: clinical outcome after six months of continuous therapy.

reuptake inhibitors (SSRIs) during continuation therapy. This investigation reports the differential effect of 6 months of treatment with sertraline versus paroxetine for symptoms of depression, quality of life, and personality outcomes. Outpatients with unipolar major depression (DSM-III-R) were randomly assigned to receive 24 weeks of double-blind treatment with flexible doses of paroxetine (20-40 mg) or sertraline (50-150 mg). Assessments included the Montgomery-Asberg Depression Rating Scale (MADRS), the Clinical Global Impression Scale, the Battelle Quality of Life Questionnaire, and the Structured Clinical Interview for DSM-III-R Personality Disorders screen questionnaire. One hundred seventy-six patients (mean age, 43 years; 64% female; baseline MADRS, 30.3) were treated with sertraline and 177 patients (mean age, 42 years; 71% female; MADRS, 30.7) with paroxetine. Antidepressant efficacy during continuation therapy was sustained, with only 2% of patients receiving sertraline and 9% of patients receiving paroxetine suffering a relapse. Continuation therapy resulted in a substantial conversion of responders during short-term treatment to full remission: remitter rates increased from 52% to 80% for sertraline and from 57% to 74% for paroxetine. The improvements in quality of life were related to a reduced depression score. SSRI treatment had significant beneficial effects on both categorical and dimensional measures of personality. A logistic regression analysis identified early response (25% reduction in MADRS scores at week 2) as the most important predictor of treatment response, whereas high severity, chronicity, and poor baseline quality of life had no effect. Both treatments were well-tolerated, with sertraline having a somewhat lower side effect profile. Sertraline and paroxetine demonstrated comparable efficacy during short-term and continuation therapy. Treatment was associated with significant improvement in quality of life and with reductions in axis II personality psychopathology.

Adolescent↗
PubMed1999

The influence of prolactin response to d-fenfluramine on executive functioning in major depression.

BACKGROUND: The main purpose of this study was to assess the influence of serotonergic activity, as measured by prolactin response to d-fenfluramine, on executive functioning in major depression. METHODS: Forty-one persons between 22 and 71 years of age who met the DSM-IV criteria for major depressive episode were administered the Wisconsin Card Sorting Test (WCST) in computerized format, and d-fenfluramine was administered orally. Postfenfluramine blood samples for ascertaining plasma prolactin levels were obtained. RESULTS: The key finding was that prolactin response was positively related to four out of five selected WCST variables. Also, increasing age was associated with decreasing WCST performance. There was no interaction between prolactin response and age, indicating that the effects of prolactin response on the WCST generalized across the age range examined. CONCLUSIONS: The overall pattern of results suggests that there may be a relationship between serotonergic activity and executive functioning in major depression.

Adult↗
PubMed1999

[Non-profit networks for suicide prevention].

Survival groups and suicide clusters constitute new challenges for suicide prevention. Emergency ward and intensive care personnel and psychologists working in close co-operation with general practitioners are strategically important in such preventive endeavours. Scientists and health care personnel need to develop joint strategies for the purpose. Politicians and administrators are important target groups for information on suicide prevention. The foregoing are important findings in the first year's experience of the West Swedish Network for Suicide Prevention.

Crisis Intervention↗
PubMed1999

The experience of social support in patients suffering from treatment-refractory depression--a pilot study.

The purpose of this study was (1) to ascertain to what extent a group of patients with treatment-refractory depression perceive that they have received sufficient social support, and (2) to define clinical variables that differentiate such patients from those who perceive that they have not received sufficient social support. Twenty-seven treatment-refractory patients with major depression were included in the study. The result showed that only 37% had what was judged as insufficient social support. Those with insufficient and sufficient social support had equally severe depressions, the same number of stressful life events, and the same number of persons in their social network. Patients with insufficient social support were characterized by (1) a subjective conviction that the number of persons in their network was insufficient, and (2) female gender. Emotional support was valued higher than any other kind of support.

Attitude to Health↗
PubMed1999

Effect of buspirone on sexual dysfunction in depressed patients treated with selective serotonin reuptake inhibitors.

To evaluate the possible influence of buspirone on sexual dysfunction in depressed patients treated with a selective serotonin reuptake inhibitor (SSRI), we analyzed data from a placebo-controlled trial designed to explore the efficacy of buspirone as add-on treatment for patients not responding to an SSRI alone. At baseline, all patients met the criteria for a major depressive episode according to DSM-IV and had received citalopram or paroxetine during a minimum of 4 weeks without responding to the treatment. Buspirone (flexible dosage, 20-60 mg/day) or placebo was added to the SSRI for 4 weeks; the mean daily dose of buspirone at endpoint was 48.5 mg (SD = 1.0). Sexual dysfunction was evaluated using a structured interview. Before starting medication with buspirone or placebo, 40% (47 of 117) reported at least one kind of sexual dysfunction (decreased libido, ejaculatory dysfunction, orgasmic dysfunction). During the 4 weeks of treatment, approximately 58% of subjects treated with buspirone reported an improvement with respect to sexual function; in the placebo group, the response rate was 30%. The difference between placebo and active drug treatment was more pronounced in women than in men. The response was obvious during the first week, with no further improvement during the course of the study. It is suggested that the effect of buspirone on sexual dysfunction is a result of a reversal of SSRI-induced sexual side effects rather than of an antidepressant effect of the drug.

Anti-Anxiety Agents↗
PubMed1999

Efficacy and tolerability of mirtazapine versus citalopram: a double-blind, randomized study in patients with major depressive disorder. Nordic Antidepressant Study Group.

We aimed to compare the antidepressant and anxiolytic effects, tolerability and effects on quality of life of mirtazapine and citalopram in a randomized, double-blind, multicentre, 8-week study. Patients with a Major Depressive Episode (DSM-IV) and a baseline score of > or = 22 on the Montgomery-Asberg Depression Rating Scale (MADRS) were randomized to 8 weeks treatment with either mirtazapine (n = 137, 15-60 mg/day) or citalopram (n = 133, 20-60 mg/day). Efficacy was evaluated by the MADRS, Hamilton Anxiety Scale (HAM-A), Clinical Global Impression scales (CGI), the Leeds Sleep Evaluation Questionnaire (LSEQ) and Quality of Life Enjoyment and Satisfaction Questionnaire (QLESQ). The efficacy analyses were performed on the Intent-To-Treat Group using the Last Observation Carried Forward method. Vital signs and laboratory variables are measured and adverse events recorded at each weekly visit. The magnitude of reduction from baseline in group mean MADRS scores was large in both groups, reaching after 8 weeks of treatment mean scores of 9.1 in the mirtazapine group and 8.9 in the citalopram group. Both treatments also resulted in a substantial improvement in anxiety symptoms, sleep disturbances and quality of life, and high percentage of responders. However, at day 14, statistically significantly larger magnitudes of change favouring mirtazapine were present in the group mean MADRS, HAM-A and CGI-Severity of illness and Quality of life scores. A difference of 2.3 points on MADRS favouring mirtazapine is considered indicative for a clinically relevant superiority between two proven antidepressants. Mirtazapine treatment was also related to faster improvement of sleep, quality of sleep and improved alertness following awakening, as shown by statistically significant differences on the self-rating LSEQ at various time points. There were no differences between two treatment groups on self-rating QLSEQ. Both drugs were well tolerated, with a low number of patients in either group prematurely terminating the study due to adverse events (mirtazapine: 3.6%, citalopram, 3.0%). Sweating and nausea were statistically significantly more frequent in the citalopram group and increased appetite and complaints of weight increase in the mirtazapine group. There were no clinically relevant changes in laboratory parameters and vital sign variables with either treatment, except for clinically relevant increase in body weight, occurring more frequently in mirtazapine patients. In this study, mirtazapine and citalopram were equally effective in reducing symptoms of depression and anxiety, and well tolerated. However, mirtazapine was significantly more effective than citalopram after 2 weeks of treatment on the MADRS, HAM-A and CGI Severity of illness and Quality of life scales. This finding, consistently present at all major efficacy variables, suggests potentially faster onset of efficacy of mirtazapine over citalopram.

Adult↗