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Biomedical subjects

K Rootwelt

Publications and source records attributed to K Rootwelt.

At least 55 records · Page 3Linked to original sources
PubMed1986

High-dose intravenous methylprednisolone pulse therapy as initial treatment in cryptogenic fibrosing alveolitis. A pilot study.

Ten patients with fibrosing alveolitis were treated in a simple random design initially with either a high dose of methylprednisolone (5 patients) or a conventional dose of prednisolone (5 patients) followed by a maintenance dose of 30 mg prednisolone daily. The patients were followed for 6 weeks. No significant (p greater than 0.05) differences were observed between patients with high and low initial dose of glucocorticosteroids, as regards forced vital capacity, transfer factor for carbon monoxide or symptom scores after 3 and 6 weeks of treatment. After 6 weeks the dyspnoea score and the 67Ga uptake decreased, on average, by 74 and 85%, respectively, while forced vital capacity and transfer factor increased by 15 and 29%.

Adult↗
PubMed1986

Changes in plasma and red cell volumes during exposure to high altitude.

Training at moderate altitude has been used by athletes to improve the performance at sea level. Not all athletes benefit from altitude training, and there also has been some doubt as to whether red cell volume increases in all subjects. Ten members of the Norwegian Everest Expedition 1985 took part in the present study. Plasma volume was determined by isotope dilution, using 125I-albumin. By simultaneous measurement of hematocrit the total blood volume and red cell volume were calculated. Measurements were done in Oslo (sea level) before departure, and in Base Camp (5300 m) four weeks later. The mean altitude during these four weeks was 4100 m. Red cell volume increased in all participants, and excessively in two of them. Since plasma volume decreased in four subjects, the change in total blood volume was less consistent. In one climber dehydration led to a decrease in total blood volume. While a significant correlation was found between maximal oxygen uptake and red cell volume at sea level, the hematologic response to altitude seemed independent on physical fitness. In one climber the erythropoietic response was so excessive (more than 50% increase in red cell volume), that he had to be hemodiluted.

Adult↗
PubMed1986

Reduced cerebral blood flow in high altitude climbers.

Cerebral blood flow (CBF) was studied by 133Xe inhalation dynamic single photon emission computer tomography in 8 members of a climbing expedition to the Himalayas. With one exception they had all previously climbed at high altitudes. All stayed above 6,500 m for approximately 3 weeks, and 5 reached the summit of Mt. Everest. CBF was measured in Oslo before, immediately after, and one year after the completion of the expedition. Measurements were made at rest and following the injection of 1 g acetazolamide intravenously. As reference group was used 13 healthy male subjects of similar age from the hospital staff. Ten age-matched male diving instructors formed a second control group. In the climbers a small, but not significant reduction in CBF was seen after the expedition. On the other hand, they had significantly lower CBF than reference subjects already before the expedition. The flow difference was most pronounced corresponding to the perfusion territory of the middle cerebral artery. One year after the completion of the expedition the average CBF in climbers was still more than 15% lower than in the reference group. The climbers had higher relative flow increase after acetazolamide injection than the reference subjects, showing that the functional capacity of the microvascular system of the brain was intact. Whether neuronal activity or number of neurones is reduced in climbers proportional to the decrease in flow, or maintained at normal level by increased oxygen and glucose extraction, cannot be answered by the present data.

Acclimatization↗
PubMed1986

Measurement of cerebral blood flow with 133Xe inhalation and dynamic single photon emission computer tomography. Normal values.

Cerebral blood flow (CBF) was studied by 133Xe inhalation tomography in 25 healthy subjects. Mean age was 41 years and range 23-66 years. Mean hemispheric CBF at rest was 59.8 ml/100 g/min, and cerebellar flow 60.8 ml/100 g/min. This difference was not statistically significant. The distribution of CBF values was skewed and approximated a log normal distribution. Estimated lower and upper normal reference range limits calculated as mean (log) +/- 2 S.D. (log) were 47-74 ml/100 g/min. Women had approximately 5 ml/100 g/min higher CBF values than men. This difference corresponded to the difference in hematocrit. Neither in men nor in women was there any tendency to age dependent reduction or increase in flow. In both sexes hemispheric regional CBF (rCBF) was asymmetric with higher flow values in the right cerebral hemisphere; particularly in the anterior distribution territory of the middle cerebral artery. In this region the maximum individual flow difference was 8 ml/100 g/min and the average difference 3.5 +/- 2.6 ml/100 g/min. Emotional activation as a consequence of the study conditions is assumed to be the cause of this observed asymmetry. Cerebellar flow was not assymetric. No significant difference in cerebellar or hemispheric CBF was found when a second study followed the first by 3-15 months. PCO2 correction of flow improved the reproducibility. The standard deviation of the flow difference between test/retest measurements was 5 ml/100 g/min. After 1 g acetazolamide given intravenously the mean increase in hemispheric CBF was 15.7 +/- 5.1 ml/100 g/min.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetazolamide↗
PubMed1985

Significance of a positive exercise ECG in middle-aged and old athletes as judged by echocardiographic, radionuclide and follow-up findings.

To study the pathologic and prognostic significance of--and possible underlying mechanisms for--a pathological exercise ECG in athletes, two age-matched groups were selected from a total population of 117 middle-aged and old endurance athletes: Group A: 21 with a pathological exercise-ECG, and group B: 21 with normal exercise-ECGs. Data from 201-thallium perfusion scintigraphy, 99 m-technetium multiple gated acquisition ventriculography (MUGA), resting echocardiography and 3 years follow-up are as follows: None had thallium findings indicating reversible myocardial ischaemia, but one from group A had a probable old myocardial infarction. All had normal resting MUGA, but group A men slightly more often presented a subnormal increase in ejection fraction according to exercise MUGA than group B men (9/20 vs 4/21). The former also more often had ventricular hypertrophy (LVH) (19/21 vs 14/21). However, apart from slightly longer ventricular filling time among group A men the echocardiograms revealed no group differences e.g. in cardiac dimensions or in indices of systolic or diastolic function. Regardless of exercise-ECG response, 18/42 athletes had one or more value of left ventricular dimensions or diameter exceeding the 95th percentile of the normal range. Since one patient from group A had asymmetric septal hypertrophy, one developed cardiomyopathy during the 3 years follow-up and one had a previous myocardial infarction, only 3/21 had cardiac disease which might explain the pathological exercise-ECG. Thus, pathological exercise-ECG rarely signifies heart disease in athletes, and very rarely coronary heart disease. Rather, the pathological exercise-ECG may be related to LVH and various subtle alterations in cardiac physiology following long-term endurance training.

Adult↗
PubMed1985

Ferrochelatase deficiency in the bone marrow in a syndrome of congenital hypochromic microcytic anemia, hyperferremia, and iron overload of the liver.

Two sisters had congenital hypochromic microcytic anemia with hyperferremia, heavy iron deposits in the liver, and reduced bone marrow iron. Liver ferrochelatase activity was within normal limits, but in the bone marrow ferrochelatase activity was only 20% of that in healthy controls. There were no findings suggestive of lead intoxication, sideroblastic anemia, or erythropoietic protoporphyria.

Adult↗
PubMed1978

Optimum laboratory test combinations for thyroid function studies, selected by discriminant analysis.

In 430 patients with a variety of thyroid disorders, linear discriminant analysis was used to select laboratory test combinations giving optimum diagnostic efficiency in thyroid function studies. Unexpectedly, TSH was found valuable in the diagnosis of hyperthyroidism and T3 in hypothyroidism. These test combinations were found optimal for the separation of euthyroidism/hyperthyroidism: T3, TSH and T4; euthyroidism/hypothyroidism: Combined free thyroid hormone index (FTI) and TSH; and hyperthyroidism/euthyroidism/hypothyroidism: T3, TSH, T4, FTI and T3U. The latter test combination had a total efficiency of 94%. Cholesterol, achilles reflex time, PBI and radioiodine uptake measurement contributed little to the discrimination.

Adolescent↗
PubMed1978

Effect of carbamazepine, phenytoin and phenobarbitone on serum levels of thyroid hormones and thyrotropin in humans.

Patients on long-term treatment with either of the stereochemically related antiepileptic drugs phenytoin (DPH) or carbamazepine (CBZ) had similar changes in serum thyroid hormone concentrations. T4, FT4, FT4 index, T3, FT3, FT3 index and rT3 were reduced, whereas T3U and TSH were not significantly different from the reference group levels. Long-term phenobarbitone treatment had no convincing effect on the investigated parameters when used alone, but possibly potentiated the effect of CBZ. In patients starting on CBZ, T4 fell to a stable 70% of the basal level after 1--2 weeks. T3 decreased transitorily to 85% of the basal level. TSH showed a complementary but somewhat delayed transitory increase. T3U and TBG did not change significantly. The effect of CBZ and DPH can be explained by interference with thyroid hormone binding to TBG combined with enzyme-induced increased metabolic clearance rate of thyroid hormones without homeostatic maintenance of premedication levels of FT4 and FT3. We suggest that the regulated factor maintaining euthyroidism in these patients is the total quantity of thyroid hormones being degraded in the tissues per unit time. We conclude that serum concentrations of FT4 and FT3 do not reflect thyroid status adequately under all circumstances.

Adult↗
PubMed1976

Infusion cisternography.

A source of error in cerebrospinal fluid (CSF) infusion tests is leakage at the dural puncture site. The addition of a bolus of radionuclide to the infusion fluid was helpful in detecting the existence of leakage as shown by increased infusion pressure in six of eight patients studied with and without scintigraphic evidence of leakage. Comparison of CSF dynamics in 26 patients studied by infusion cisternography and conventional cisternography showed similar patterns, suggesting no alteration of CSF dynamics by the artificial CSF infusion. Combining the two tests, therefore, resulted in simple identification of the leakage and saved the patient time and discomfort.

Cisterna Magna↗
PubMed1976

Use of 131I-toluidine blue in radionuclide imaging of enlarged parathyroid glands.

Parathyroid scintigraphy with 131I-labelled toluidine blue was performed in 40 patients, 30 of whom were operated for suspected hyperparathyroidism. Hyperplastic glands or adenomas could be localized by scintigraphy in 18 of 27 patients who proved to have hyperparathyroidism. The correlation between scintigraphy and operative finding was always correct when the parathyroids weighed more than 2 g. Scintigraphy was correctly negative in one, falsely negative in 6, and falsely positive in 5 of the operated patients. In a group of 10 unoperated patients, scintigraphy was positive in one of the 3 patients with suspected hyperparathyroidism, but negative in the others. Although 131I-toluidine blue is not ideal as a scintigraphic agent for the parathyroids, we are of the opinion that it represents an improvement compared with 75Se-selenomethionine.

Evaluation Studies as Topic↗
PubMed1975

Effects of dipyridamole and acetylsalicylic acid on platelet functions in patients with aortic ball-valve prostheses.

The effects of dipyridamole and ASA on platelet functions were studied in patients with aortic ball-valve prostheses. Before ingestion, platelet adhesiveness was markedly reduced and platelet survival time slightly, but insignificantly shortened. ASA prolonged the bleeding time, reduced collagen-induced platelet aggregation, and inhibited secondary aggregation initiated by adrenalin. Similar effects were obtained with 2 Gm. of ASA alone as with 1 Gm. daily in combination with 225 mg. of dipyridamole. Platelet adhesiveness remained low. Depyridamole alone, 375 mg. daily, did not influence any of these parameters. The mean platelet half-life was prolonged from 3.52 to 3.72 days by each drug and to 4 days by the combined treatment. None of the differences was, however, statistically significant. A clinical study with ASA has been started in a larger series of patients to evaluate the effect on arterial thromboembolism.

Aortic Valve↗
PubMed1975

A comparison between urography and radioisotope renography in the follow-up of surgery for hydronephrosis.

The result of surgical correction of hydronephrosis caused by chronic obstruction at the pyeloureteral junction has been evaluated clinically as well as by urography and body background substracted renography performed preoperatively and up to 65 months postoperatively. The average follow-up period was 24 months. Twenty-eight patients (29 kidneys) were operated. Clinically 24 patients were improved. Urography showed regress of hydronephrosis and/or improved urinary pelvic drainage in 22 patients, whereas kidney function is judged from renography was improved in only 8 patients. Improvement in all parameters was generally most marked during the first postoperative months. Renographic improvement was seen much more often when the contralateral (non-operated) kidney was abnormal. Thus, kidney function in terms of effective renal plasma flow is rather uninfluenced by hydronephrosis surgery if the contralateral kidney is normal, whereas clinical improvement in urinary drainage is regularly obtained. This improvement in drainage is poorly registered by renography. It is concluded that renography is an important complementary method to urography, but the method cannot replace the radiological methods in the follow-up of hydronephrosis surgery.

Adolescent↗