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Biomedical subjects

R Ekman

Publications and source records attributed to R Ekman.

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

A follow up study of suicide attempters: increase of CSF-somatostatin but no change in CSF-CRH.

Concentrations of somatostatin and corticotrophin releasing hormone (CRH), measured in cerebrospinal fluid (CSF) have been reported to be low in suicidal patients with major depressive disorder (MDD). Often have MDD patients in general, high CSF-CRH and low CSF-somatostatin concentrations, which both seem to normalise with clinical recovery. The present study was designed to look for CSF-CRH and CSF-somatostatin alterations along with clinical changes in patients studied repeatedly after a suicide attempt. Sixteen patients with different diagnoses, initially inpatients after a suicide attempt (baseline), participated. Lumbar punctures and ratings according to the Suicidal Assessment Scale (SUAS) and the Montgomery-Asberg Depression Rating Scale (MADRS) were performed while patients were drug-free (baseline) and after a median of 7 (5 to 9) months. At follow up MADRS- and SUAS-scores were significantly decreased (P<0.05), whereas CSF-somatostatin was significantly increased (P=0.013) and CSF-CRH had not changed significantly. Thus, the patients showed long-lasting low CSF-CRH concentrations, in spite of changed CSF-somatostatin concentrations and clinical amelioration.

Adult↗
PubMed2001

Bicycle-related injuries among the elderly--a new epidemic?

Bicycling in Sweden has almost doubled between 1980 and 1992/3 among persons aged 25-64 y. The upward trend is continuing. For the elderly (65 or older) the bicycle is a common means of transport, in both Sweden and a number of other countries. Almost one-third of the Swedish population aged 65 or older bike at some time during the year. The objectives of this study are to describe the pattern of, and trend in, bicycle-related injuries among the elderly in Sweden and to discuss possible means of injury prevention. Mortality data come from official death certificates (1967-96). Hospital-discharge data (1985-96) are also employed, divided into three age groups (-14, 15-64 and 65-), by external cause according to the ICD-9, and also into 'all diagnoses' and 'head injuries'. Number of cases and days of hospital care for persons aged 65 or more, on aggregate and by gender, are reported for 1996. The whole of Sweden and its northern and southern parts separately were investigated. 2830 bicyclists were killed over the period 1967-96, of which 47% were 65 or older. The risk of dying due to bicycling was about 3.7 times greater among the elderly than among children aged 14 or under. There were significant changes in injury trends for all age groups between 1985 and 1996 with regard to hospital care. Annual average decreases for children, of 2.2% for all diagnoses and of 3.4% for head injuries, were observed. For the other two age groups there were increases in all injuries of 3.4% (15-64) and of 2.9% (65-), and increases in head injuries of 4.6% (15-64) and 2.7% (65-). For the elderly living in the southern part of Sweden, there was an increase on average of 2.2% per year over the period, compared with 4.2% for those in the northern part. Males showed a higher incidence of injuries and received longer periods of care than females. Do we have an epidemic of bicycle injuries among the elderly? They face a greater risk of being injured or killed than his/her younger counterpart. For all ages the risk is 7.4 times higher for a bicyclist than for a car driver. The risk for the elderly is about 3 times greater than for the average bicyclist, and as much as 6 times higher for the age group 75-84 y. With some few exceptions, there is no doubt that society has neglected the problem. Decision-makers have a tendency to focus on the relatively young. But people are living longer today and the elderly are healthier, which indicates the need for greater interest and more intervention. We have signs of an epidemic, but one that can be ameliorated or prevented. Just waiting for injury to occur leads only to premature death or lifelong disability.

Adolescent↗
PubMed2001

Future aspects of psychoneuroimmunology - lymphocyte peptides reflecting psychiatric disorders studied by mass spectrometry.

We have investigated whether cytoplasmatic and nuclear extracts of human peripheral blood lymphocytes contain arginine vasopressin (AVP), of importance for memory functions, in samples from healthy controls and patients diagnosed as depressed. It is the first time as AVP, AVP-fragments and chemically modified AVP-forms have been demonstrated in lymphocyte/nuclear extracts. This was performed by an HPLC-purification step, followed by a second immunoprecipitation step before identification by mass spectrometry. We are developing new methods using a combination of high-resolution mass spectrometry and separation techniques such as capillary electrophoresis and nano liquid chromatography. We have named this methodological approach when studying endogenous peptides -Peptidomics.

Arginine Vasopressin↗
PubMed2001

Development of a national injury prevention/safe community programme in Vietnam.

The aim of this study is to describe the initiation of a national programme on injury prevention/safe community (IP/SC). Market economy, Doi Moi, was introduced in Vietnam in 1986, and since then the injury pattern has been reported to have changed. The number of traffic injury deaths has increased three-fold from 1980 to 1996 and traffic injuries more than four-fold. Injuries are now the leading cause of mortality in hospitals. There are difficulties in obtaining a comprehensive picture of the injury pattern from official statistics and, in conjunction with the work initiated by the Ministry of Health, a number of local reporting systems have already been developed. Remarkable results have been achieved within the IP/SC in a very short time, based on 20 years of experience. An organizational construction system has been built from province to local community areas. Management is based on administrative and legislative documents. IP/SC implementation is considered the duty of the whole community, local authorities and people committees, and should be incorporated into local action plans. The programme is a significant contribution towards creating a safe environment in which everybody may live and work, allowing the stability for society to develop. Implementation of the programme in schools is a special characteristic. The programme will be developed in 800 schools with a large number of pupils (25% of the population). This model for safer schools is considerably concerned and is a good experience to disseminate. The recommendations are that more pilot models of IP/SC should be conducted in other localities and that the programme should be expanded to a national scale. Furthermore, co-operation between sectors and mass organizations should be encouraged and professional skills of key SC members at all levels should be raised.

Accidents, Traffic↗
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

[Laboratory diagnosis of gastrinoma. Nordic collaboration can improve the quality].

Measurement of gastrin in serum or plasma in patients with gastrinoma may be complicated by the presence of circulating biosynthetic intermediates which may not be detected by commonly available immunoassays. In contrast, the "processing-independent analysis" of gastrins developed by professor Jens Rehfeld et al in Copenhagen detects gastrin forms irrespective of their size. The authors review gastrinoma pathophysiology, the biochemistry of gastrin and other biomarkers of gastrinoma, the differential diagnosis of hypergastrinemia as well as other methods currently employed in the workup of gastrinoma patients, and illustrate with a clinical case.

Biomarkers, Tumor↗
PubMed2000

Detection and quantification of neurotensin in human brain tissue by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

A method was developed for mass spectrometric detection of neurotensin (NT)-like immunoreactivity and quantification of NT in human brain tissue. The method is based on immunoprecipitation followed by analysis using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The identity of the major component of the immunoprecipitates as neurotensin was confirmed by fragment ion analysis on an electrospray ionization quadrupole time-of-flight instrument. MALDI-TOF-MS quantification of NT was achieved using stable-isotope-labeled NT as the internal standard, yielding an error of less than 5%. The method allowed detection of low-femtomole amounts of NT, staring from low-milligram amounts of lyophilized brain tissue. In addition to NT, several other peptides were detected in the purified samples, most of which, according to their molecular masses, corresponded to fragments of NT. The method is demonstrated with quantification of NT from human hypothalamus tissue, and a comparison is made with results obtained from competitive radioimmunoassay.

Brain Chemistry↗
PubMed2000

Cognitive functioning and cerebrospinal fluid concentrations of neuropeptides for patients with good neurological outcomes after aneurysmal subarachnoid hemorrhage.

OBJECTIVE: Many patients exhibit cognitive disturbances after aneurysmal subarachnoid hemorrhage (SAH). Structural and functional neuroimaging has failed to demonstrate any correlation with these complaints. This study was performed to investigate whether neuropeptide concentrations in cerebrospinal fluid could be related to cognitive disturbances after SAH. METHODS: Lumbar cerebrospinal fluid was obtained, 3 to 6 months after surgery, from 17 patients who experienced good outcomes after aneurysmal SAH. The samples were analyzed for various neuropeptides using radioimmunoassays, and the peptide concentrations were evaluated in relation to scores on standardized neuropsychological tests. RESULTS: The neuropsychological test results were normal for eight individuals, whereas the remaining nine patients exhibited various degrees of cognitive impairment. There was no correlation between the concentrations of arginine vasopressin or neuropeptide Y and test performance. However, significant correlations between cognitive impairment and elevated levels of beta-endorphins (P = 0.02), corticotropin-releasing factor (P = 0.004), and delta sleep-inducing peptide (P = 0.045) were noted. CONCLUSION: Patients with cognitive impairments after aneurysmal SAH exhibited higher cerebrospinal fluid concentrations of endorphins, corticotropin-releasing factor, and delta sleep-inducing peptide than did those with normal capacity. This is probably attributable to diffuse derangement of transmitter release in the brain, resulting from the insult or ensuing complications, although a secondary increase in corticotropin-releasing factor concentrations caused by increased stress during the testing because of reduced cognitive capacity cannot be excluded.

Adult↗
PubMed2000

CSF sulfatide distinguishes between normal pressure hydrocephalus and subcortical arteriosclerotic encephalopathy.

OBJECTIVES: To examine the CSF concentrations of molecules reflecting demyelination, neuronal and axonal degeneration, gliosis, monoaminergic neuronal function, and aminergic and peptidergic neurotransmission in a large series of patients with normal pressure hydrocephalus (NPH) or subcortical arteriosclerotic encephalopathy (SAE), to elucidate pathogenic, diagnostic, and prognostic features. METHODS: CSF concentrations of glycosphingolipid (sulfatide), proteins (neurofilament triplet protein (NFL), glial fibrillary acidic protein (GFAP)), neuropeptides (vasoactive intestinal peptide (VIP), 4-aminobutyric acid (GABA)), and monoamines (homovanillic acid (HVA), 5-hydroxy-indoleacetic acid (5-HIAA), 4-hydroxy-3-methoxyphenylglycol (HMPG)) were analysed in 43 patients with NPH and 19 patients with SAE. The diagnoses of NPH and SAE were based on strict criteria and patients with NPH were subsequently operated on. Twelve clinical variables, psychometric tests measuring perceptual speed, accuracy, learning, and memory and a psychiatric evaluation were performed in all patients and before and after a shunt operation in patients with NPH. RESULTS: The CSF sulfatide concentration was markedly increased in patients with SAE (mean 766, range 300-3800 nmol/l) compared with patients with NPH (mean 206, range 50-400 nmol/l) (p<0.001). 5-HIAA, GABA, and VIP in CSF were higher in patients with SAE than in patients with NPH. The patients with NPH with cerebrovascular aetiology had higher sulfatide concentrations and a poorer outcome after shunt surgery than patients with NPH with other aetiologies. CONCLUSIONS: The pathogenesis of the white matter changes in NPH and SAE is different and ischaemic white matter changes can be a part of the NPH state. The markedly increased CSF sulfatide concentrations in patients with SAE indicate ongoing demyelination as an important pathophysiological feature of SAE. The CSF sulfatide concentration distinguished between patients with SAE and those with NPH with a sensitivity of 74% and a specificity of 94%, making it an important diagnostic marker.

Adult↗
PubMed2000

Three-week neonatal hypoxia reduces blood CGRP and causes persistent pulmonary hypertension in rats.

To increase understanding of persistent pulmonary hypertension, we examined chronic pulmonary effects of hypoxia at birth and their relationships with immunoreactive levels of the potent vasodilator, calcitonin gene-related peptide (CGRP). Rats were born in 10% hypobaric hypoxia, where they remained for 1-2 days, or in 15% hypoxia, where they remained for 21 days. All were then reared in normoxia for 3 mo followed by reexposure to 10% hypoxia for 7 days (H-->H) or continued normoxia (H-->N); age-matched normoxic rats were hypoxic for the last 7 days (N-->H) or normoxic throughout (N-->N). Results are as follows. Pulmonary arterial pressure (P(PA)) in 10% H-->N rats was normal at the end of the experiment (13 wk), but in rats reexposed to hypoxia (H-->H), pressure rose to 19% above N-->H controls. In 15% H-->N rats, P(PA) remained high, similar to that of N-->H rats, and increased further by 40% on reexposure (H-->H). Medial thickness of small pulmonary arteries in 10% H-->H rats also increased by 40% over N-->H controls and was equally high in 15% H-->N and H-->H rats. In N-->H rats from both experiments, right ventricular hypertrophy index (RVH) was increased after hypoxia at 15-16 wk. Also, in the 15% study, RVH remained elevated in H-->N rats and increased in H-->H rats by 19% above N-->H controls. Blood CGRP was reduced by neonate and adult hypoxia, and hypoxic reexposure (H-->H) further lowered blood CGRP in the 15% but not 10% study. Declining left ventricular blood CGRP correlated highly with logarithmically increasing P(PA) in the 15% study (r = -0.81, P = 0.000). In conclusion, 1) short perinatal exposure to 10% O(2) exacerbated pulmonary hypertension with hypoxia later in life, 2) 15% O(2) at birth and for 21 days caused persistent pulmonary hypertension and exacerbation with reexposure, and 3) P(PA) correlated highly with declining blood CGRP levels in the 15% study.

Animals↗
PubMed1999

The synaptic-vesicle-specific proteins rab3a and synaptophysin are reduced in thalamus and related cortical brain regions in schizophrenic brains.

Two synaptic-vesicle proteins, rab3a and synaptophysin, have been studied on post-mortem brain tissues of schizophrenics and healthy controls. We found significantly reduced levels of rab3a in thalamus (p<0.001); for both proteins in gyrus cinguli and hippocampus (p<0.0001); for rab3a in frontal and parietal cortex (p<0.05); and no differences in temporal cortex or cerebellum in schizophrenics compared with controls. Reduced synaptic density may be a prominent feature of the molecular neuropathology of schizophrenia.

Adult↗
PubMed1999

Behavioral and endocrine adaptation, and up-regulation of NPY expression in rat amygdala following repeated restraint stress.

A single 1 h restraint increases experimental anxiety in the elevated plus-maze through actions within the amygdala, while intra-amygdala administration of neuropeptide Y (NPY) has the opposite effect. Endogenous amygdala NPY expression is suppressed by single restraint, providing a possible mechanism for the anxiety-promoting action of this stressor. Here, we examined whether repeated stressor exposure might lead to an adaptation (habituation or sensitization) with regard to plus-maze behavior and glucocorticoid response, and whether this might be accompanied by altered effects of the stressor on NPY expression. Following repeated restraint (1 h/day, 9-10 days), neither an anxiogenic-like effect of the stressor nor a glucocorticoid response were present. This behavioral and endocrine adaptation was accompanied by an up-regulation of prepro-NPY mRNA and NPY peptide in amygdala but not in hypothalamic or cortical extracts, an effect opposite to that previously seen after a single restraint session. Thus, an up-regulation of NPY expression in the amygdala complex may be an adaptive mechanism recruited to cope with a repeated stressor.

Adaptation, Physiological↗
PubMed1999

[How reliable is the laboratory? Increased needs of patient-related quality assurance].

Recent developments in medical care and research involve the increased use of immunochemical assays for hormones, tumour markers, vitamins and drugs. External quality assurance programmes using pooled human sera usually fail to detect analytical interference due to substances (e.g. anti-immunoglobulin or anti-ligand antibodies) present in individual serum specimens. The article reports on experience gained during a three-year period when specimens from individual patients attending a thyroid unit were distributed to hospital laboratories in Sweden for analysis. Specimen selection criteria were based on contradictory findings at the initial clinical or laboratory evaluation. The programme has given rise to the formation of a network of the laboratories involved, under the co-ordination of EQUALIS (External quality assurance in laboratory medicine in Sweden).

Antibodies↗
PubMed1999

Sample purification and preparation technique based on nano-scale reversed-phase columns for the sensitive analysis of complex peptide mixtures by matrix-assisted laser desorption/ionization mass spectrometry.

A simple reversed-phase nano-column purification and sample preparation technique is described, which markedly improves the mass spectrometric analysis of complex and contaminated peptide mixtures by matrix-assisted laser desorption/ionization (MALDI). The method is simple, fast and utilizes only low-cost disposables. After loading the sample on the column and a subsequent washing step, the analyte molecules are eluted with 50-100 nl of matrix solution directly on to the MALDI/MS target. The washing step ensures removal of a wide range of contaminants. The small bed volume of the column allows efficient sample concentration and the elution process yields very small sample spots. This simplifies the analysis and minimizes discrimination effects due to sample heterogeneity, because the desorption/ionization laser simultaneously irradiates a large portion of the sample. Taken together, these features of the method significantly improve the sensitivity for MALDI/MS analysis of contaminated peptide samples compared with the commonly used sample preparation procedures. This is demonstrated with in-gel tryptic digests of proteins from human brain that were separated by 2D gel electrophoresis. Furthermore, it is shown that with this method 2,5-dihydroxybenzoic acid (DHB) acts as an efficient matrix for peptide mapping. Both detection sensitivity and sequence coverage are comparable to those obtained with the currently preferred matrix alpha-cyano-4-hydroxycinnamic acid (CHCA). The higher stability of peptide ions generated with DHB compared with CHCA is advantageous when analyzing fragile sample molecules. Therefore, the method described here is also of interest for the use of Fourier transform ion cyclotron resonance (FT-ICR) or ion-trap mass analyzers.

Animals↗
PubMed1999

Plasma levels of substance P, neuropeptide Y and vasoactive intestinal polypeptide in patients with chronic tension-type headache.

Animal and human studies have shown that substance P (SP), neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) are involved in the pathophysiology of acute and chronic pain conditions. The primary aim of the present study was to compare plasma levels of SP, NPY and VIP in external jugular vein between patients with chronic tension-type headache and healthy controls. The secondary aim was to examine plasma levels of these neuropeptides in relation to headache state. In addition, we wanted to study the relation between cranial circulation (jugular vein) and peripheral circulation (antecubital vein). Blood from the external jugular and antecubital vein was drawn from 20 patients with chronic tension-type headache and 20 healthy controls. Plasma SP in patients, 2.0 (1.4-2.2) pmol/l, did not differ significantly from plasma SP in controls, 1.7 (1.1-2.1) pmol/l, (P=0.44). No significant differences were found between SP levels on days with headache, 1.5 (0.3-1.7) pmol/l, and SP levels on days without headache, 1.7 (1.1-1. 9) pmol/l, (P=0.06). Plasma NPY in patients, 118+/-3 pmol/l, did not differ significantly from plasma NPY in controls, 113+/-5 pmol/l, (P=0.40). There was no difference between NPY levels on days with headache, 120+/-3 pmol/l, and on days without headache, 118+/-3 pmol/l, (P=0.73). VIP levels in patients, 6 (4-7) pmol/l, did not differ significantly from VIP levels in controls, 5 (5-7) pmol/l, (P=0.50). No significant differences were found between VIP levels measured on days with headache, 5 (4-6) pmol/l, and VIP levels measured on days without headache, 6 (4-7) pmol/l, (P=0.81). Plasma levels of SP, NPY and VIP did not significantly differ between the peripheral and the cranial circulation neither in patients nor in controls (0.05). In summary, the present study indicates that plasma levels of SP, NPY and VIP are normal in chronic tension-type headache patients and largely unrelated to headache state.

Adult↗
PubMed1999

Alterations of corticotropin releasing hormone (CRH) and neuropeptide Y (NPY) plasma levels in mood disorder patients with a recent suicide attempt.

In order to receive a further understanding of stress-regulation in depressed suicide attempters, peptides that are supposed to be related to the stress system (the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system) were studied in plasma. When compared with healthy controls, cortisol was high (p<0.001) and corticotropin releasing hormone (CRH) and neuropeptide Y (NPY) appeared to be low (p<0.001) in patients who had recently attempted suicide. Patients who had repeatedly attempted suicide had the lowest NPY. A correlation between NPY and cortisol (p<0.05) was found in suicidal patients with depression NOS, whereas beta-endorphins correlated with cortisol (p<0.01) in suicidal patients with major depressive disorder. A postdexamethasone decrease of NPY was noted in the controls but not in the patients. These results suggest stress system alterations in suicidal patients with mood disorders.

Adult↗