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Biomedical subjects

H Dige-Petersen

Publications and source records attributed to H Dige-Petersen.

At least 19 recordsLinked to original sources
PubMed1992

Effect of ketanserin on global cerebral blood flow and cerebral oxygen metabolism during midazolam-fentanyl or isoflurane anaesthesia.

We have studied the effect of ketanserin on cerebral blood flow (CBF), cerebral oxygen metabolism (CMRO2) and cerebrovascular carbon dioxide reactivity in 19 adult patients undergoing lumbar disc operation--10 during midazolam-fentanyl anaesthesia (group A) and nine during isoflurane anaesthesia (group B). Measurements were made in each patient whilst awake, during anaesthesia, during anaesthesia with ketanserin and during anaesthesia with ketanserin and hyperventilation. CBF was measured by the i.v. xenon-133 technique. CMRO2 was calculated as the product of CBF and the cerebral arterio-venous oxygen content difference. In the awake state, CBF was 52 and 51 ml/100 g min-1 and CMRO2 3.8 and 3.5 ml/100 g min-1 in groups A and B, respectively. After induction of anaesthesia, CBF decreased 37% in group A and 22% in group B (P < 0.05); CMRO2 decreased 26% in group A and 51% in group B (P < 0.05). Adding ketanserin did not change CBF or CMRO2 in either group. The carbon dioxide reactivity of the cerebral vessels during anaesthesia with ketanserin was 15.4% kPa-1 in group A and 24% kPa-1 in group B. We concluded that ketanserin, in a clinically recommended dose, administered during midazolam-fentanyl or isoflurane anaesthesia had no effect on global CBF, CMRO2 or the relationship between the two factors. Cerebrovascular carbon dioxide reactivity was preserved.

Adult↗
PubMed1992

Permanent, skin penetrating, bone-anchored titanium implants. A clinical study of host-reaction in bone and soft tissue.

In 12 patients with a skin penetrating retroauricular titanium-implant (Brånemark) the reaction in bone and soft tissue was studied. Observation time was 6 to 36 months. All implants were "osseointegrated", as assessed by repeated manual test, X-ray examination and 99mTC-scintigraphy. Soft tissue reactions appeared to be slight and clinically insignificant. However, all patients produced crusts around the abutment. When the abutment was removed varying degrees of inflammatory reaction in the skin penetration could be observed in most patients. A theory for the development and cause of the soft tissue reactions is proposed and changes in the operative procedure and the design of the abutment to reduce the host reaction are suggested. It is stressed that the clinical significance of this host reaction is uncertain and above all has to be weighed against the important benefits this implant system offers to a severely handicapped group of patients.

Adult↗
PubMed1992

Radioimmunoassay of endothelin in human plasma.

A specific and sensitive radioimmunoassay (RIA) for determination of endothelin-1 (ET-1) in human plasma has been developed. Antibodies were raised in rabbits using synthetic ET-1 conjugated to thyroglobulin as immunogen. The antibodies obtained were used at a final dilution of 1:300,000 yielding maximum binding of 61.7 +/- 3.0% (mean +/- 1 SD, n = 20) of 125I-ET-1. The ID50 (inhibitory dose 50%) was 4.5 +/- 0.6 fmol/100 microliters (mean +/- 1 SD, n = 20). The sensitivity of the RIA was 0.33 fmol/100 microliters standard solution. No cross reactivity was observed with endothelin-3, big-endothelin-1, atrial natriuretic factor, angiotensin I or angiotensin II. The cross-reactivity with endothelin-2 was 100%. Endothelin was extracted from acidified plasma with Sep-pak C18 cartridges and recovery of ET-1 added to normal plasma was 70.9 +/- 10.3% (mean +/- 1 SD, n = 12). The concentration of ET-1 in plasma from normal subjects was 1.5 +/- 0.4 pmol/l (mean +/- 1 SD, n = 11) ranging from 1.0 to 2.2 pmol/1. Extracts of normal human plasma subjected to high performance liquid chromatography on a reverse phase C18 column showed one peak of immunoreactivity co-eluting with the standard for ET-1. From these data it is concluded that the immunoreactive material measured in normal plasma with the present RIA is identical to ET-1.

Animals↗
PubMed1989

Gastric emptying of liquid meals: validation of the gamma camera technique.

In order to assess the extent of errors and to provide correction factors for gamma camera gastric emptying studies of liquid meals labelled with radionuclides (99Tcm or 113Inm), a series of phantom studies were performed with different gastric emptying procedures, gamma cameras and data handling systems. To validate the overall accuracy of the method, 24 combined aspiration and gamma camera gastric emptying studies were carried out in three normal volunteers. Gastric meal volume, expressed as a percentage of the original volume of the meal ingested was underestimated due to scattered radiation from the stomach. The underestimation was 7-20% varying with the size of the gastric region of interest (ROI), the energy of the nuclide and the fraction of meal in the stomach. The overestimation, due to scattered radiation from the gut, was negligible (1-3%) for any of the procedures with 10% of the meal situated outside the stomach at a distance of at least 1 cm. Sections of the duodenal loop were always inside the stomach ROI and were likely to contain a constant fraction of the meal (3-10%). The gamma camera technique eliminated much of the error due to variations of stomach geometry and produced accurate quantitative gastric emptying data comparable to those obtained by evacuation (P greater than 0.10), when the entire field maximum 1-min count achieved within the first 20 min of a study was taken as representing the original volume of the meal ingested, and when corrections for area related errors due to scattered radiation from the stomach were performed.

Gastric Emptying↗
PubMed1989

Evaluation of renal function and morphology in children by 99mTc-DTPA gamma camera renography.

The purpose of the present investigation was to evaluate the use of 99mTc-DTPA (diethylenetriaminepenta-acetate) gamma camera renography for the study of kidney function as well as morphology. Sixty-nine children with urinary tract infection or congenital hydronephrosis aged 6 days to 13.6 years were studied. A method for determination of the glomerular filtration rate (GFR) from the recorded curves without use of blood or urine samples was tested in 65 consecutive children. From each renogram an uptake index was determined. After a weight/height correction the sum of right and left kidney uptake index correlated with total GFR determined from plasma clearance of 51Cr-EDTA (ethylenediaminetetra-acetate) measured on the same day (r = 0.96). The relative standard error of estimating GFR from the renograms was 10.7% at GFR = 100 ml/min and 14.6% at GFR = 50 ml/min. In a subgroup including 20 children no difference was found in kidney morphology and length studied by renography and intravenous urography, the latter providing more details concerning the urinary tract. Relative kidney length did not correlate with relative renal function determined by renography, emphasizing the difficulty in determination of relative renal function by urography. In conclusion, not only relative but also absolute renal function (GFR) can be determined in children by 99mTc-DTPA renography; at the same time kidney and urinary tract morphology are evaluated. In our hands, 99mTc-DTPA renography has become a useful diagnostic tool, lowering the need for the more cumbersome intravenous urography and 51Cr-EDTA plasma clearance. However, intravenous urography is mandatory for the detailed study of the urinary tract, and use of the 51Cr-EDTA plasma clearance technique is necessary when a very reliable determination of GFR is wanted.

Adolescent↗
PubMed1989

Gastric emptying of liquid meals. A study in 88 normal persons.

Using a gamma camera, gastric emptying of a nutrient liquid meal labelled with 99m-Tc-DTPA has been studied in 88 normal subjects in order to assess reproducibility and to establish the range for gastric emptying under standardized conditions. The emptying patterns were visualized as time-activity curves. The early phase (0-15 min) was characterized by a rapid emptying taking place during the first minutes and a subsequent period of almost no emptying (plateau) lasting for up to 20 minutes, followed by an almost constant emptying in the later phase (15-60 min). In the early and later phase mean percentages emptied were 13% (range, 0-30) and 49% (range, 9-79), respectively. The intraindividual variation was larger for repeated tests of months' than of days' intervals, the coefficients of variation in the early phase being on the average 72% (range, 29-175) and 37% (range, 13-128), respectively. During the later phase less variation was seen. Irregular deviations from the standard pattern were observed in the curves, indicating gastric contractions and duodenogastric reflux. Serial scintifotos revealed that the radionuclide labelled gastric content was not uniformly distributed within the stomach. This activity distribution, affected by the subject's position during emptying, seemed to occur instantaneously and to be completed within a few minutes. These findings allow the standardized radioisotope technique to be used for physiological, pathophysiological and pharmacological studies, when performing consecutive studies in the same individual within days or a few weeks. The wide reference interval for gastric emptying of this liquid meal invalidates the method as a clinical diagnostic tool.

Adult↗
PubMed1988

Somatic manifestations in children suspected of having been maltreated.

The present study revealed an incidence of maltreatment of 26.8 in 100,000 children under 15 years of age, higher than previously assumed. The sample comprises 41 children suspected of having been maltreated. A systematic examination included radiography and isotope scintigraphy of the skeletal system. In 9 cases the diagnosis was not confirmed, in 23 confirmed, and in 9 children it seemed likely. The most common form of maltreatment was physical violence with bruises. A total of 6 fractures were demonstrated. Three children had been exposed to sexual abuse. Intracranial haematoma, of long standing, was found in one child. Thirteen of the children (40%) were of short statute, their height and weight below the 25th percentile. Among 27 children examined by X-rays 16 (59%) had delayed skeletal maturation. Disturbances of growth, as well as behavioural abnormalities, were particularly striking in this group of patients. The findings suggest that even the slightest suspicion of maltreatment should lead to a general medical evaluation without delay.

Adolescent↗
PubMed1988

The reliability of measuring left ventricular ejection fraction by radionuclide cardiography: evaluation by the method of variance components.

A statistical model based on the method of variance components was applied to obtain confidence statements for single and repeat determinations of left ventricular ejection fraction by radionuclide techniques. With this approach variance caused by individual factors in the measurement procedure is estimated to allow calculation of confidence intervals based on single measurements and the detection limits for changes. Six study groups made up of a total of 143 subjects were examined by both multigated equilibrium and first pass imaging. Under favourable conditions (with an updated gamma camera and experienced observer) the 95% confidence interval with a single measurement of left ventricular ejection fraction by equilibrium imaging was +/- 3 ejection fraction units, compared with +/- 6 units with the first pass technique (one ejection fraction unit = 1/100 of the possible values from 0.00 to 1.00). The minimal significant changes (at the 5% level) in measured equilibrium left ventricular ejection fraction at intervals of 15 min, 3 days, 1, 3, and 4 weeks were +/- 4, +/- 4, +/- 5, +/- 5, and +/- 6 units, respectively. The corresponding minimal detectable changes in a subject's "true" left ventricular ejection fraction for the same intervals were +/- 7, +/- 7, +/- 10, +/- 10, and +/- 12 units respectively. With first pass imaging, only average values for the variation at repeat determination could be calculated. The minimal significant change in measured first pass left ventricular ejection fraction was +/- 7 units, and the minimal detectable change in "true" left ventricular ejection fraction was +/- 14 units. Measurements of left ventricular ejection fraction by equilibrium technique were generally more reproducible than first pass determinations because the variability caused by study acquisition, observer analysis, and residual errors was smaller. The method of variance components appears to be well suited to the evaluation of quantitative biological measurements in clinical use. The popularity of established procedures may obscure the lack of basic information about method evaluation.

Adult↗
PubMed1986

Effects of combined therapy with amiloride and hydrochlorothiazide on plasma and total body potassium, blood pressure, and the renin-angiotensin-aldosterone system in hypertensive patients.

After a run-in period of 8 weeks on a regimen of hydrochlorothiazide (HCT, median dosage 75 mg/day), patients with essential hypertension were randomly allocated to continued hydrochlorothiazide therapy (Group I) or additional treatment with amiloride (Group II, median dosage 15 mg/day, or 5 mg per 25 mg hydrochlorothiazide) for the following 12 weeks. Thereafter all the patients were changed to treatment with a fixed combination tablet containing 5 mg amiloride and 50 mg hydrochlorothiazide (Moduretic), keeping the thiazide dosage unchanged for an additional 12 weeks. In Group I patients there was no change in plasma potassium, total body potassium content or the renin-angiotensin-aldosterone system during the 12 weeks on HCT. When the treatment was changed to Moduretic, significant increases were found of 10% in plasma potassium and 3% in total body potassium content. No important stimulation of the renin-angiotensin-aldosterone system was found. In Group II patients addition of an average of 15 mg amiloride to the hydrochlorothiazide treatment led to significant increases in plasma potassium and total body potassium content of approximately 15% and 4%, respectively. There was also a significant increase in the plasma concentrations of renin, angiotensin II and aldosterone. Reducing the average dose of amiloride to 7.5 mg/day by use of Moduretic did not lead to decrease in plasma potassium or total body potassium content. Plasma concentrations of renin, angiotensin II, and aldosterone were decreased, but the individual changes varied markedly and no significant overall change was found.

Adult↗
PubMed1978

A comparison of 99Tc and 123I scintigraphy in nodular thyroid disorders.

Out of 450 patients referred for thyroid scintigraphy 83 consecutive patients with nodular goitre were selected for dual scintigraphy with 99mTc and 123I. Seventy-four patients had one or more palpable nodules and the other nine patients had palpably diffuse goitres with one or more nodules on the routine 99mTc scintigram. For the comparison of scintigrams an eight level colour display was used, and regional differences between the 99mTc and 123I scintigrams were defined as a minimum of 25% (2 colour levels) variation of the relative activity in well defined areas. Thirteen patients, i.e. 16% of those with nodular goitre, had discordant scintigrams. All 13 patients had non-malignant thyroid disorders, (simple goitre, radio-iodine treated hyperthyroidism, autonomous adenoma, subacute thyroiditis, Riedel's and lymphocytic thyroiditis). The diagnosis was verified histologically in eight of these patients. Eight of the 13 patients had a high 99mTc activity relative to 123I, five patients showed the opposite discrepancy. Another 5 patients with a follicular or mixed follicular thyroid carcinoma had identical scintigrams. These findings indicate that 123I does not offer such diagnostic advantages over the cheap and readily available 99mTc, that its use for routine scintigraphy of the thyroid gland seems to be justified at present.

Adenoma↗
PubMed1978

Lung split function test and pneumonectomy. A lower limit for operability.

Regional 133Xe ventilation/perfusion studies were used to predict residual lung function after pulmonary resections. The accuracy of the method was good as checked by postoperative spirometry in 11 patients. In 25 patients with impaired lung function and pulmonary cancer, who were consecutively selected for surgery, the predicted postoperative maximal breathing capacities (MBC) ranged from 17 to 41 l/min-1 m-2. No patients became permanent pulmonary invalids. One patient died from myocardial infarction, 7 had transient pulmonary insufficiency and 17 patients survived operation without complications. Perfusion studies alone proved as reliable as perfusion/ventilation studies.

Aged↗
PubMed1977

Subclinical ergotism.

The systolic blood-pressure at the ankle and the first toe was measured in 30 patients, mean age 42, who had taken ergotamine regularly for more than a year. With one exception, the patients had no symptoms or signs of arterial insufficiency in the limbs, but all had low-normal or abnormal foot systolic blood-pressures. In a group of 13 patients who stopped taking ergotamine the distal pressures rose significantly and from the ninth day were normal.

Adult↗
PubMed1977

Pituitary-thyroid responsiveness to thyrotropin-releasing hormone in preterm and small-for-gestational age newborns.

A dose of 40 microgram TRH was injected intravenously in 12 preterm (PT) and 15 small-for-gestational age (SGA) babies (with advanced gestational ages) between 5 and 167 hours after birth. Serum-thyrotropin (TSH) was measured prior to and 30 and 180 min after TRH; serum-thyroxine (T4) and serum-triiodothyronine (T3) were measured prior to and 180 min after TRH. The percentage increase in serum-TSH in PT and SGA babies was comparable to that of fullterm newborns. The serum-TSH 30 min after TRH in SGA newborns was significantly correlated to basal TSH values, such a correlation could not be shown in the preterms. One SGA and four PT babies had a repeat TRH-test performed later in infancy: In all but one PT with a gestational age of 27 weeks the TSH rise was lower than in the neonatal period. The thyroid hormone responses after TRH were similar in the two groups of babies. The percentage increase above basal levels were: Median serum-T3 increase about 46% and median serum-T4 increase about 14%. It is concluded that in low-birth-weight newborn babies the pituitary TSH response to exogenous TRH was like that detected in fullterm newborns and more pronounced that later in infancy. The effect of endogenous TSH as measured by thyroid hormone increases was of the same magnitude as observed in fullterms and in adults.

Female↗
PubMed1977

Effect of thyrotrophin releasing hormone (TRH) in patients with pituitary disorders.

The secretion and biological activity of thyroid stimulating hormone (TSH) were studied in 22 patients with a pituitary tumour (17 acromegalics and 5 patients with a chromophobe adenoma) and in 36 hypophysectomized patients (16 acromegalics and 20 with a chromophobe adenoma). Thyroid function was assessed by serum thyroxine (T4), serum triiodothyronine (T3), and thyroxine-binding globulin (TBG) concentration. Serum TSH was measured before and after injection of TSH releasing hormone (TRH), and in 19 hypophysectomized patients the T3 response after TRH was measured. In addition a TRH test was performed 1-2 weeks after surgery in 11 patients. The basal serum TSH did not differ from euthyroid control values in any of the groups and no late effect of hypophysectomy was observed. Subnormal peak TSH values were seen in 10 out of 37 euthyroid patients, whereas 9 out of 11 hypothyroid patients responded normally. Hypophysectomy caused an immediate but transient decrease in peak TSH in patients with a chromophobe adenoma only. The rise in serum T3 after TRH was significantly lower in hypophysectomized patients than in controls. An increase in TSH was followed by a T3 response in all patients except in 4 out of 8 euthyroid acromegalics. In patients operated on for a chromophobe adenoma the T3 response was correlated with serum T4, whereas this was not the case in acromegalics.

Acromegaly↗