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Biomedical subjects

K Rasmussen

Publications and source records attributed to K Rasmussen.

At least 235 records · Page 13Linked to original sources
PubMed1991

High performance liquid chromatography method for rapid and accurate determination of homocysteine in plasma and serum.

Determination of homocysteine in plasma or serum for evaluation of cobalamin and folate deficiency is becoming an important diagnostic procedure. Accurate, rapid and low cost methods for measuring homocysteine are therefore required. We have improved an HPLC method and made it suitable for clinical application. The more important changes are the addition of an internal standard, mercaptopropionylglycine, and the use of a plasma/serum based calibration material. The method consists of the following steps: reduction of the sample with tri-n-butylphosphine, precipitation of proteins, derivatisation with ammonium 7-fluorobenzo-2-oxa-1,3-diazole-4-sulphonate, and HPLC separation followed by fluorescence detection. The linearity of the assays is established and the coefficient of variation is 3.0%. Stability studies show that blood samples must be cooled or centrifuged immediately after venipuncture. The method is useful for evaluation of cobalamin or folate deficiency, especially in patients with normal or moderately depressed cobalamin or folate concentrations in blood.

Chromatography, High Pressure Liquid↗
PubMed1991

Treatment of Parkinson's disease with electroconvulsive therapy.

There is substantial evidence that electroconvulsive therapy (ECT) can ameliorate the symptoms of Parkinson's disease independent of any antidepressant activity. ECT thus presents a treatment alternative for the severely impaired, medication-resistant Parkinson's patient. In this article, we review the literature on this subject and present our recommendations for current clinical practice.

Aged↗
PubMed1990

[Reflections on the professional and organizational development of internal medicine].

A steadily increasing body of knowledge has led to the current system of specialization and sub-specialization in medicine. A potential danger is sub-subspecialization and fragmentation of service to patients. Internal medicine must therefore remain undisrupted and given possibilities of growth. The foremost challenge of internal medicine today is to further develop its own diagnostic and therapeutic culture. Traditionally, the internist has been the advocate of rational clinical diagnostics. Clinical diagnostics must remain the starting point of the diagnostic process. Our therapeutic culture is linked in particular to conducting and analysing large clinical trials. Internal medicine is also playing an increasingly important role in the organization of proper care for the old and the dying.

Internal Medicine↗
PubMed1990

[Experience with Doppler echocardiography in infants with systolic murmur].

In a one-year period, 33 infants with a systolic cardiac murmur were examined by Doppler-echocardiography. The clinical diagnosis based on ECG, X-ray and physical examination by a pediatrician or cardiologist was changed or established by Doppler-echocardiographic examination in 63% of the cases. In almost all cases, this meant changing of the strategy concerning further diagnostic evaluation and therapy. In eight (24%) of the infants no malformation was detected by Doppler-echocardiography, and no further cardiological examinations were carried out. In eight (24%) infants a complex heart malformation was detected. Three of these infants had no clinical signs of heart disease except for the murmur. Because an early and accurate diagnosis is important in the management of infants with heart disease, we recommend that infants suspected of having congenital heart disease are examined by Doppler-echocardiography in a department with experience in this technique.

Echocardiography, Doppler↗
PubMed1990

[Health screening in the workplace. Benefits and principles].

This article describes the prophylactic programmes for health surveillance which exist in the occupational environment in Denmark. Compared with other industrialised countries, Denmark has only few established surveillance programmes. Nevertheless, these investigations exist, particularly in the form of non-specific general clinical health investigations at local workplaces, in certain branch agreements and in certain types of work. In addition, the article provides a review of the literature concerning health and health-economic effects of supervision of health. It is concluded that with the existing knowledge, pre-employment examinations and periodic health examinations as routine examinations without and clearly defined object must be regarded as having limited prophylactic value and that examinations of this nature can scarcely give the worker any health benefit or give the employer any economic profit. On the other hand, programmes of this nature may give the employees a false sense of security and contribute towards interpreting of justifiable levels of exposure, on an incorrect basis. Biological monitoring and occupational medical screening include, as a rule, more well directed programmes which will probably be employed to a greater extent in the coming years. Finally, a set of American directives for criteria of utilization, particularly for screening in occupational medicine are discussed. It is maintained here, among other things, the necessity of an integrated analysis of biological monitoring, screening and control of exposure so that health surveillance can be of benefit for all the employees at a workplace and not only the individual worker.

Denmark↗
PubMed1990

[Chlorinated solvents and fetal damage. Spontaneous abortions, low birth weight and malformations among women employed in the dry-cleaning industry].

Workers in the dry-cleaning industry are exposed to vapours from the cleaning fluids, primarily perchlorethylene, which is a chlorinated solvent. Animal experiments, short-term tests for mutagenic effects and epidemiological investigations have raised the suspicion that perchlorethylene may cause reproductive failure. This investigation is an attempt to assess the risk for reproductive failure in 886 women exposed to dry-cleaning solvents while employed in dry-cleaning establishments. Twelve spontaneous abortions occurred, one infant was born with malformations and ten infants had low birth weights. A non-significant risk for spontaneous abortion was found among women with the greatest exposure. This estimate is, however, uncertain and the result must be interpreted with care.

Abortion, Legal↗
PubMed1990

[Anesthesiologic aspects of narco-curare-electroshock treatment].

The physiology and side-effects of narco-curare-electric shock treatment are reviewed on the basis of the literature and, similarly, risk groups are delimited. Directives for preoperative assessment, the anaesthesiological procedure and per- and postoperative observation are given. It is concluded that the NCE procedure is associated with a low risk and slight mortality provided the above-mentioned conditions are observed. Patients with cardiovascular disease constitute the greatest risk group and should receive optimal medical treatment prior to NCE. In cases with raised intracranial pressure, NCE should only be employed with great reservation. ECG monitoring, treatment with atropine and preliminary treatment with oxygen are advised in general. Withdrawal of psychocopharmaca prior to NCE is rarely indicated.

Anesthesia, General↗
PubMed1990

[Exposure of Danish workers to trichloroethylene during the period 1947-1987].

Trichloroethylene, an organic solvent from the group of chlorinated hydrocarbons, has been employed throughout the greater part of this century particularly for degreasing of metals, dry cleaning and as a content in glue and lacquer. Biological monitoring of workers exposed to trichloroethylene as current health supervision has been employed in Danish factories since 1947 as the metabolite trichloroacetic acid in the urine provides an indication of the degree of exposure during the preceding week. In the present investigation, a review was undertaken of all measurements of trichloroacetic acid notified to the Danish Labour Inspection Service during the period 1947-1987 in order to obtain an impression of the historical development in the level of exposure. A total of 2,272 biological measurements distributed among 330 factories, reveal exposure of about the same level from the middle of the fifties to the middle of the seventies but with a distinct fall during the period, as the average value during the first five-year period was 82 mg/l as compared with 18 mg/l at the end of this 40-years period. These data are supplemented by case-histories from the earliest part of the period described by doctors from the Danish Labour Inspection Service.

Air Pollutants, Occupational↗
PubMed1990

[Measurement of the quality of life as a element in assessing therapeutic effects in essential arterial hypertension. Methodologic aspects].

The quality of life has become an important element in assessment of medicinal treatment. As an independent expression, the quality of life covers the human disappointments which a medical disease may involve ("discomfort") whereas the clinical dysfunction caused by the disease is covered by the expression "disability". In the treatment of essential arterial hypertension, the clinical symptoms of the disease are few or none ("asymptomatic hypertension"). In an investigation of 303 patients in general practice for arterial hypertension, the significance of the frequency of dosage of metoprolol (Seloken) was assessed by means of measurement of the quality of life by the General Health Questionnaire (GHQ), a questionnaire which contains components such as fatigue, sleep, anxiety and depression. No advantages in the quality of life were found in administering antihypertensive drugs once or twice daily. From the methological point of view, the following conditions were found which should be taken into consideration in future investigations in this field: The GHQ was found to be easy for the patients to employ. This is important as the quality of life is a personally experienced dimension. The questionnaire correlated adequately with the visual analogue scales. Approximately 1/3 of the patients had reduced quality of life at the commencement of the investigation as assessed by GHQ. A multiple regression analysis revealed that the reduced well-being was due to social, life events and side effects. It is therefore recommended that these aspects should be described when patients commence a course of medicinal treatment i.e. the social life events and side effects of the medicine in connection with the actual subjective dimension of quality of life.

Adult↗
PubMed1990

[Pregnancy and the work place. Risk assessment during a 5-year period at an occupational medicine clinic].

If the occupational environment of a pregnant women is considered to present the risk for injurious effects on the foetus, there has been a possibility in Denmark since 1981 in the Maintenance Allowance legislation for absence from work on account of the particular occupation during the entire duration of the ascertained pregnancy. Assessment of the risk for foetal damage in the occupational environment is undertaken primarily by the general practitioner with advice and the possibility for more detailed assessment of the risk from Workers' Supervision Authorities and the Clinic for Occupational Medicine. The principles for assessing the risk in the Clinic for Occupational Medicine are reviewed on the basis of 144 cases from the period 1983-1987 and these are illustrated by three case histories. In addition, the main principles in assessing the risk are reviewed. At present, risks are considered to be in occupations involving work with chemicals, heavy lifting and EDB screens.

Adult↗
PubMed1990

Serotonin excitation of facial motoneurons: receptor subtype characterization.

The receptor subtype(s) mediating the enhancement of facial motoneuron excitability by serotonin (5-HT) was evaluated by means of single-cell recording in vivo (in the anesthetized rat) and in vitro in brain slices. In vivo, microiontophoretic application of the broad-spectrum 5-HT1 agonist 5-carboxamidotryptamine (5-CT), the 5-HT2/5-HT1C agonist 1-[2,5-dimethoxy-4-methylphenyl]-2-aminopropane (DOM), but not the selective 5-HT1A agonist 8-OH-2[di-n-propylamino]tetralin (8-OH-DPAT), produced a 5-HT-like enhancement of facial motoneuron excitability. Intravenous administration of the 5-HT2/5-HT1C antagonists ritanserin and LY 53857 in vivo blocked the facilitatory effects of 5-HT and DOM, but not norepinephrine (NE). Similarly, in brain slices, bath application of ritanserin blocked the effects of 5-HT, DOM, and 5-CT, but not NE on facial motoneurons. Intracellular recordings showed that DOM induced a slow depolarization and an increase in evoked spikes, but these effects were of lesser magnitude and longer duration than those produced by 5-HT. Taken together, these results indicate a role for 5-HT2 and/or 5-HT1C but not 5-HT1A receptors in serotonergic enhancement of facial motoneuron excitability since 5-HT's effect was 1) at least partially mimicked by the selective 5-HT2/5-HT1C agonist DOM, 2) mimicked by the broad-spectrum 5-HT1 agonist 5-CT but not the selective 5-HT1A agonist 8-OH-DPAT, and 3) blocked by the 5-HT2/5-HT1C antagonists ritanserin and LY 53857.

DOM 2,5-Dimethoxy-4-Methylamphetamine↗
PubMed1990

Alcohol decreases serum osteocalcin in a dose-dependent way in normal subjects.

The acute effect of 25 and 50 g of alcohol on the variation in serum osteocalcin, a specific and sensitive marker of bone formation, and on serum cortisol and serum parathyroid hormone (PTH)(1-84) was calculated in 6 normal young adults. They were studied during three periods, each lasting from 4 p.m.-7:30 a.m. Alcohol was ingested between 4:15 and 5 p.m. during period two and three. Blood was taken at 4 p.m. and every 15 minutes from 4:30 til 6 p.m., followed by hourly sampling until 12 p.m. The last blood sample was taken after an overnight fast at 7:30 a.m. Initial and end values before and after alcohol ingestion did not differ significantly from control values. Repeated measures analysis of variance showed that 50 g of ethanol decreased serum osteocalcin significantly (P less than 0.02) and increased serum cortisol (P less than 0.05) during the 4-12 p.m. interval. The interaction of 50 g of ethanol on the variation in serum osteocalcin was already significant during the first 2 hours (P less than 0.02), where no significant effect on serum cortisol could be detected. Although insignificant, the same pattern was observed after 25 g of alcohol. There was no significant change in the variation of serum iPTH(1-84) during the 4-6 p.m. after alcohol intake. We conclude that 3-4 drinks of alcohol taken over 45 minutes decreases serum osteocalcin in a dose-dependent way. The time lag between changes in serum osteocalcin and cortisol indicates that the decrease in serum osteocalcin is not related to the increase in serum cortisol.

Adult↗
PubMed1990

Monitoring of renal allografts by Doppler ultrasound: precision and reference values.

The Doppler ultrasound method was used to obtain blood flow velocity curves from one of the large segmental arteries near the pelvis of transplanted renal allografts. The precision of the method for estimation of the pulsatility index (PI), the ratio between the peak systolic and the least diastolic velocity (A/B ratio) and the ratio of the are under the velocity curve of the first half and the second half of the cardiac cycle (AUC 1/2 ratio) was tested in vivo by examination of six renal allograft patients eight times. Two investigators examined each patient twice in random order upon two successive days. To investigate variation with time the same 10 patients were examined four times with 6-8 week intervals. To establish normal ranges for the PI, the A/B ratio and the AUC 1/2 ratio, a cross-sectional study of 54 patients with stable and well-functioning renal allografts was performed. No systematic variation was found between observers, days or repeated observations. The mean coefficient of variation was 8.3% for the pulsatility index, 5.8% for the A/B ratio and 14.9% for the AUC 1/2 ratio. The longitudinal study showed no systematic variation of the indices with time. For the 54 patients in the cross-sectional study the mean pulsatility index was 0.78, the mean A/B ratio 2.62 and the mean AUC ratio 1.82.

Blood Flow Velocity↗
PubMed1990

Doppler ultrasound in the diagnosis of renal allograft rejection and in monitoring the effect of treatment.

Thirty-six consecutively transplanted renal allograft patients were prospectively monitored with ultrasound-Doppler examinations three times weekly during the first 3 weeks after transplantation. Although triple-immunosuppressive therapy consisting of cyclosporin A, azathioprine and prednisolone was used, acute rejection occurred in 11 patients. Nine patients had immediate onset of graft function and no rejection. Ten patients had acute tubular necrosis (ATN) without any signs of rejection and were treated with dialysis for 1-3 weeks after transplantation. Thrombosis of the renal artery was diagnosed in four patients. During rejection episodes pulsatility index (PI) was above normal range in all patients. In patients with mild to moderate ATN and PI was normal throughout the clinical course whereas two patients with severe ATN but no signs of rejection in the kidney biopsy also had high PI. It is concluded that serial Doppler velocity examination after kidney transplantation is a non-invasive, cheap and reliable method for monitoring of the graft. The method can be used in the early diagnosis of rejection, and it is of special value in monitoring grafts without function.

Azathioprine↗
PubMed1990

The relationship between clinically confirmed cobalamin deficiency and serum methylmalonic acid.

Over a 1-year period, we examined 42 consecutive patients with low serum cobalamin levels detected by primary screening test (S-protein binder, RIA). In 31 patients (74%) clinical cobalamin deficiency was confirmed, whereas the remaining 11 patients (26%) were characterized clinically as non-cobalamin deficient. The serum methylmalonic acid level was higher than 0.34 mumol l-1 (3 SD above the mean in normal controls) in 30 of the 31 clinically characterized cobalamin-deficient subjects, and below this level in 10 of the 11 non-deficient patients. We conclude that the serum methylmalonic acid assay provides an appropriate means of discrimination between cobalamin deficiency and non-cobalamin deficiency (efficiency = 0.95), and we recommend that the assay be adopted as the standard test for diagnosis of tissue cobalamin deficiency.

Adult↗
PubMed1990

In situ hybridization analysis of isodicentric X-chromosomes with short arm fusion.

We present here an alternative approach to the study of mosaic cell lines containing dicentric chromosomes. The approach is based on chromosome-specific non-radioactive in situ hybridization with centromere (alpha satellite DNA) probes. The hybridization analysis may be used as an alternative to the C-band analysis, while at the same time to some extent replacing the Q-band analysis as well. The advantage of using in situ hybridization is mainly that it allows the very fast screening of a large number of metaphases. We illustrate this new application of the technique by using it for the analysis of two cases of isodicentric X-chromosomes. The approach is expected to be generally applicable, so that it may be applied to the scoring of other types of chromosomal mosaicism as well.

Child↗
PubMed1990

Electrophysiology of the central serotonin system: receptor subtypes and transducer mechanisms.

It is becoming evident that the diverse electrophysiological actions of 5-HT in the central nervous system can be best formulated in terms of receptor subtypes and their respective effector mechanisms. Based on the findings described in this review, the following pattern of central 5-HT electrophysiology is emerging: 1) inhibitory effects are mediated by 5-HT1 receptors linked to the opening of K channels via pertussis-toxin sensitive G proteins: 2) facilitatory effects are mediated by 5-HT2 receptors and involve the closing of K channels, an effect which appears to be negatively modulated by activation of the PI second messenger system: 3) fast excitations are mediated by 5-HT3 receptors, most likely involving a direct interaction with an ion channel rather than through coupling with a G protein or a second messenger. Further studies will be required in a wider range of brain areas to establish the generality of these conclusions.

Animals↗