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Biomedical subjects

M Kjaer

Publications and source records attributed to M Kjaer.

At least 217 records · Page 12Linked to original sources
PubMed1985

Effect of exercise on epinephrine turnover in trained and untrained male subjects.

The kinetics underlying plasma epinephrine concentrations were studied. Six athletes (T) and six sedentary males (C) were given intravenous infusions of 3H-labeled epinephrine, after which arterial blood was drawn. They rested sitting and bicycled continuously to exhaustion (60 min at 125 W, 60 min at 160 W, 40 min at 200 W, and 240 W to the end). Work time was 154 +/- 13 (SE) (T) and 75 +/- 6 (C) min. At rest, epinephrine clearance was identical [28.4 +/- 1.3 (T) vs. 29.2 +/- 1.8 (C) ml . kg-1 . min-1], but plasma concentration [1.42 +/- 0.27 (T) vs. 0.71 +/- 0.16 (C) nmol . l-1] and, accordingly, secretion [2.9 +/- 0.7 vs. 1.5 +/- 0.4 nmol . min-1] were higher (P less than 0.05) in T than C subjects. Epinephrine clearance was closely related to relative work load, decreasing from 15% above the basal level at 30% of maximal O2 uptake (VO2 max) to 22% below at 76% of VO2 max. Epinephrine concentrations increased much more with work intensity than could be accounted for by changes in clearance and were, at exhaustion, higher (P less than 0.05) in T (7.2 +/- 1.6) than in C (2.5 +/- 0.7 nmol . l-1) subjects despite similar glucose, heart rate, and hematocrit values. At a given load, epinephrine clearance rapidly became constant, whereas concentration increased continuously. Forearm extraction of epinephrine invalidated use of blood from a cubital vein or a hand vein arterialized by hot water in turnover measurements. During exercise, changes in epinephrine concentrations reflect changes in secretion rather than in clearance. Training may increase adrenal medullary secretory capacity.

Adrenal Medulla↗
PubMed1984

Glucose turnover and hormonal changes during insulin-induced hypoglycemia in trained humans.

Eight athletes (T), studied the third morning after the last exercise session, and seven sedentary males (C) (maximal O2 consumption 65 +/- 4 vs. 49 +/- 4 (SE) ml X kg-1 X min-1, for T and C men, respectively) had insulin infused until plasma glucose, at an insulin level of 1,600 pmol X l-1, was 1.9 mmol X l-1. Glucose turnover was determined by primed constant rate infusion of 3-[3H]glucose. Basal C-peptide (0.46 +/- 0.04 vs. 0.73 +/- 0.06 pmol X ml-1) and glucagon (4 +/- 0.4 vs. 10 +/- 2 pmol X l-1) were lower (P less than 0.05) and epinephrine higher (0.30 +/- 0.06 vs. 0.09 +/- 0.03 nmol X l-1) in T than in C subjects. During and after insulin infusion production, disappearance and clearance of glucose changed identically in T and C subjects. However, in spite of identical plasma glucose concentrations, epinephrine (7.88 +/- 0.99 vs. 3.97 +/- 0.40 nmol X l-1), growth hormone (97 +/- 17 vs. 64 +/- 6 mU X l-1), and pancreatic polypeptide (361 +/- 84 vs. 180 +/- 29 pmol X l-1) reached higher levels (P less than 0.05) and glucagon (28 +/- 3 vs. 47 +/- 10 pmol X l-1) lower levels in T than in C subjects. Blood pressures changed earlier in athletes during insulin infusion, and early recovery of heart rate, free fatty acid, and glycerol was faster. Responses of norepinephrine, cortisol, C-peptide, and lactate were similar in the two groups. Training radically changes hormonal responses but not glucose kinetics in insulin hypoglycemia.

Adult↗
PubMed1984

Whole body and regional clearances of noradrenaline and adrenaline in man.

The whole body clearance of noradrenaline (NA) was measured in seven patients pre- and postoperatively. L-3H-NA was infused intravenously for 90 min and steady-state concentrations of L-3H-NA were measured in both arterial and peripheral venous blood. Preoperatively, in the resting supine position the clearance values based on arterial and venous sampling averaged 1.4 and 2.5 l/min, respectively (p less than 0.02). The difference in clearance values was due to peripheral uptake of NA averaging 45%. The plasma appearance rate on NA averaged 2.4 nmol/min before surgery and it increased to 9.5 nmol/min postoperatively (p less than 0.02). The plasma clearance of NA did not change. These results indicate that the calculation of plasma NA clearance based on venous sampling results in values that are too high. Furthermore, such values may be influenced by individual variations in the peripheral uptake of NA, since we found no correlation between clearance values based on venous and arterial sampling. In other experiments we measured the influence of physical exercise in young healthy subjects on the clearance rate of plasma adrenaline (A). The clearance of A, which at rest averaged 1.9 l/min tended to increase at low work loads and to decrease below resting levels at high exercise intensity. The changes were, however, small (+/- 20% of resting values). The regional extraction ratio of NA was 0.5 to 0.6 in the forearm, the liver and the kidney.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Misonidazole combined with radiotherapy in the treatment of inoperable squamous cell carcinoma of the lung. A double-blind randomized trial.

Sixty-seven patients with inoperable squamous cell carcinoma of the lung were randomized to receive split-course irradiation therapy, 40 Gy in 10 fractions over 5 weeks plus either placebo or misonidazole 1.200 mg/m2 orally on each treatment day. The target area was the primary tumor, both hilar regions, mediastinum, and both supraclavicular regions. Thirty-three patients received misonidazole, while 34 patients received placebo. Mean observation time for the study was 27 months (range, 17-36+ months. 31% of the patients in the misonidazole group obtained a complete response (CR) or a partial response (PR) as compared to 29% in the placebo group. No difference was demonstrated in the relapse pattern comparing the two groups. The death intensity was significantly higher (P = 0.03) in the misonidazole than in the placebo group, with the median survival being 4.2 and 6.7 months, respectively. Eight patients in the misonidazole group (31%) developed sensoric neuropathy while one patient in the placebo group developed irradiation myelopathy of the Brown-Sequard type. The group of patients who later developed neuropathy had significantly higher plasma misonidazole concentrations on treatment days than the group of patients who did not. It is concluded that the combination of misonidazole and irradiation therapy for inoperable squamous cell carcinoma of the lung has no effect on response rate and relapse pattern, but a significant unexplained adverse effect on survival.

Aged↗
PubMed1983

The analgesic effect of the GABA-agonist THIP in patients with chronic pain of malignant origin. A phase-1-2 study.

Fourteen patients with chronic pain of malignant origin were treated with escalating doses of THIP intramuscularly 5-30 mg in an open phase 1 study. Analgesic activity was demonstrated in 60% of the patients at the level of 20 mg THIP and a dose response relation was present. Side effects, sedation, dizziness, euphoria, nausea, and blurred vision were present in up to 80% of the patients and were dose limiting. The maximum serum concentration was reached within 1 h after dosing in 87% of all administrations. Mean t1/2 was 1.52 +/- 0.63 h and the clearance was 0.49 +/- 0.181 min. Significant correlations were demonstrated between serum concentration, dose of THIP, analgesic effect and side effects. It is concluded that THIP cannot be used for the treatment of chronic cancer pain, not because of insufficient analgesic effect but because of unacceptable side effects.

Adult↗
PubMed1983

Evoked potentials. With special reference to the diagnostic value in multiple sclerosis.

A survey is given of my studies of evoked potentials in patients with multiple sclerosis (MS) and in control subjects. Potentials were recorded following random low-rate auditory stimulation (BAEP), checker-board pattern-reversal stimulation (VEP), somatosensory stimulation (SEP); blink reflexes (BR) were recorded following electrical stimulation of the supraorbital nerve. Normal data had to be related to age and sex in evaluating BAEPs and VEPs. In 160 MS patients, a total of 421 recordings were obtained. Changes by repeated BAEP and VEP tests might reflect changes in the clinical state, but they also did occur in clinically stable patients. In patients with definite MS, high incidences of abnormality were shown, supporting the clinical findings. The diagnostic value was greatest when clinically silent lesions were demonstrated in patients with suspected or possible MS. In these patients, either BAEP or VEP gave evidence of subclinical lesions in about 50%, and when combined, in 71% of the patients, thus making a transfer to a more certain diagnostic classification possible and invasive examinations unnecessary. When SEP and BR tests were added, subclinical lesions were found in 74% of the patients. The SEP recordings did show a high incidence of abnormality, but only few silent lesions; the BR test was the least sensitive. The VEP was abnormal in all patients with signs of optic neuritis and in all but one with a history of optic neuritis. The present results are compared to those obtained in other laboratories and with other types of examinations in MS patients. It is concluded that although the tests are not specific for MS, they give valuable information in the majority of patients with a clinically uncertain diagnosis. This information will most often not be given by other types of examination. The combination of VEP and BAEP is recommended, but it should be supplemented by SEP recording in patients without spinal signs.

Adolescent↗
PubMed1982

The clinical course and prognosis of patients with renal adenocarcinoma with solitary metastasis.

The present investigation describes a series of 25 patients with solitary metastasis from a renal adenocarcinoma. Forty-eight percent of the patients had metastatic foci in bones, 24% in the lungs, and 28% in a variety of organs. Radiotherapy was the treatment for 64% of the patients, surgery for 36%. Disease control after treatment was obtained in 88% of the patients. The 5-year survival rate was 39%. Sixteen of 25 patients died after a mean survival time of 36 months; 9/25 patients are still living 28-126 months after treatment. Women survived significantly better than men. Patients with normal pre- and post-treatment erythrocyte sedimentation rate (ESR) survived significantly longer than patients with elevated ESR. A definite relationship between ESR and disease activity was demonstrated in 64% of the patients. We concluded that solitary metastases in bones can be treated with radiotherapy; even if 64% of the patients die there is significant clinical remission to be obtained after aggressive treatment. Furthermore, ESR seems to be an important indicator of prognosis and disease activity.

Adenocarcinoma↗
PubMed1982

A comparative study of intramuscular buprenorphine and morphine in the treatment of chronic pain of malignant origin.

1 Twenty-seven patients with moderate to severe chronic pain of malignant origin received buprenorphine (0.3 mg) and morphine (10 mg) intramuscularly in a double-blind, single dose within patient study. 2 Efficacy analysis demonstrated no significant differences in the peak analgesic effects or in the time to reach these effects. However, buprenorphine had a significantly longer duration of action than morphine. 3 Sedation was the most frequent unwanted effect with a similar incidence following each treatment. Buprenorphine was associated with a significantly higher incidence, greater severity, earlier onset, and longer duration of dizziness, nausea and vomiting than morphine. 4 Following both treatments there were small but significant decreases in pulse rate, blood pressure, and respiratory rate.

Adult↗
PubMed1980

Variations of brain stem auditory evoked potentials correlated to duration and severity of multiple sclerosis.

A total of 158 recordings of brain stem auditory evoked potentials (BAEPs) were obtained in 121 patients with multiple sclerosis. A statistically significant increased incidence of abnormality and diffusely abnormal recordings was found with increasing duration and severity of symptoms. Alterations in follow-up recordings might reflect changes in the clinical state, but also occurred in clinically stable patients. These findings suggested that transition from normality of BAEPs might occur either by successive disappearance of the later waves or by uniformly decreasing amplitudes of all the waves to diffusely abnormal recordings. It was concluded that the main value of BAEP recording in patients with multiple sclerosis was to indicate clinically silent lesions, and its value in monitoring the clinical condition of the individual patient was dubious.

Adolescent↗
PubMed1980

Localizing brain stem lesions with brain stem auditory evoked potentials.

Based on a survey of brain stem auditory evoked potentials (BAEPs) in animals and humans with localized brain stem lesions compared to the recognizability of BAEP components in normal materials, it was concluded that BAEP examination might localize lesions to a high or low level and diffusely within the brain stem. In 155 patients with multiple sclerosis, vascular disorders or other lesions from a neurological department, the involvement of the brain stem was clinically estimated to be negative, situated at a high or low level or diffuse. Correlation between location of the lesions assessed by clinical versus BAEP examination showed correspondence between negative and diffusely abnormal findings, but not with regard to levels within the brain stem. CT-scanning similarly failed to localize lesions to various levels. This was probably due to poorly circumscribed or widespread lesions. The main value of BAEP in neurological patients was to establish clinically silent lesions, especially in patients with multiple sclerosis and only spinal signs.

Animals↗
PubMed1980

Visual evoked potentials in normal subjects and patients with multiple sclerosis.

Visual evoked potentials (VEPs) by checkerboard pattern-reversal stimulation were recorded in 70 subjects aged 10--69 years and in 100 patients with definite, probable or possible multiple sclerosis (MS). Longer latencies and smaller amplitudes of the major positive component were found in male subjects, in old subjects and when the amplifier's band-pass was narrowed. Subjects 10--14 years old had longer latencies and higher amplitudes than mature adults. Based on findings in the normal material, the following three criteria were used in evaluating the recordings from patients: the latency, the side difference in latencies and the ratio of amplitudes between the two sides of the major positive component with various limits for the two sexes and different age groups. The incidence of abnormal recordings was 85% for all the patients, 100% in 50 patients with definite, 70% in 50 patients with probable or possible MS, 73% in patients who had a history of spinal symptoms only, 98% if they had and 74% if they had not experienced optic neuritis. The incidence of abnormal findings increased with increasing duration of symptoms. All patients with visual acuity below 0.67 had abnormal VEPs. The high incidence of abnormal recordings confirmed the value of the test in establishing the diagnosis, and suggested that the use of different normative values for sex and age may increase the diagnostic yield without increasing the number of false positive findings.

Adolescent↗
PubMed1980

Brain stem auditory and visual evoked potentials in multiple sclerosis.

The diagnostic value of the checkerboard pattern-reversal visual evoked potential (VEP) and the random, low rate stimulated brain stem auditory evoked potential (BAEP) was compared in 99 patients with established or suspected multiple sclerosis (MS). In normal subjects examined by both techniques no abnormal recordings were found. In 49 patients with definite MS an incidence of abnormality was found in 100% of VEP and in 84% of BAEP recordings. In 50 patients with probable or possible MS an abnormal VEP was found in 70% and an abnormal BAEP in 50%. When the two examinations were combined, the diagnostic yield increased to 100 and 80%, respectively. 22 patients had only spinal symptoms; in these the VEP gave 73%, the BAEP 55% and the combination 82% abnormalities. The combination of the two techniques was found useful for demonstrating demyelinating lesions in the central nervous system, the diagnostic value being greatest when these lesions were clinically silent.

Acoustic Stimulation↗
PubMed1980

Recognizability of brain stem auditory evoked potential components.

In examining neurological patients suspected of having a brain stem lesion with brain stem auditory evoked potentials (BAEPs), a technique giving high amplitudes and/or maximal recognizability of most of the components was preferred. An increase of interstimulus intervals and stimulus strength and a widening of the band-passes of the amplifier were found to increase the amplitudes and the recognizability in BAEPs from normal subjects and patients. A random monaural 75 dBHL stimulation with 230 msec intervals and frequency cut-offs of the amplifier of 50--5,000 c/sec was chosen as the standard procedure. In normal subjects aged 10--69 years, a decrease in amplitudes was found with increasing age. Men older than 50 years had longer latencies than younger men. Women had shorter latencies and higher amplitudes than men. Waves I, III and V were recognized in all normal subjects; the recognizability of waves II, IV and VI was 94% or more in subjects younger than 50 years, 85--93% in the oldest subjects.

Acoustic Stimulation↗