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Biomedical subjects

H Dige-Petersen

Publications and source records attributed to H Dige-Petersen.

17 recordsLinked to original sources

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

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

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

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

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

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

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

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

Thyrotropin response to thyrotropin-releasing hormone in fullterm, euthyroid and hypothyroid newborns.

The serum concentration of thyrotropin (TSH) and the TSH response following thyrotropin-releasing hormone (TRH) were studied in 16 euthyroid babies from 16 to 172 hours after birth and in 2 primary hypothyroid babies, 3 and 28 days of age. Serum-TSH was measured before an intravenous injection of 40 mug TRH and after 30 and 180 min. In the euthyroid babies increased basal levels of TSH were seen shortly after birth, followed by a pronounced decline. The extent of TSH increase after TRH could be correlated with the basal levels, and the relative increase was comparable to that which occurs in adults. In the hypothyroid babies very high basal levels of serum-TSH were seen, 125 and 400 muU/ml respectively, with no further increase following TRH stimulation. It was concluded that in euthyroid fullterm newborn, the relative response of serum-TSH to TRH was equal to that of adults, in spite of elevated thyroid hormone concentrations. In the hypothyroid newborn very high levels of serum-TSH were seen and a supplementary TRH-test seems without diagnostic value in congenital hypothyroidism.

Congenital Hypothyroidism

Evolution of autonomy in idiopathic non-toxic goiter, evaluated by regional suppressibility of 99mTc-uptake and TSH response to TRH.

Seventeen euthyroid patients with non-toxic goiter were studied, 7 had diffuse goiters and 10 had nodular goiters. The TSH response to TRH and the 99mTc-uptake were measured before and after T3 suppression. The uptake, measured with a gamma camera, was calculated for the whole gland and for a maximum of 6 regions within the thyroid gland. The suppressibility of 99mTc-uptake (percent change of uptake) ranged from 0 to 95%, it was significantly greater in patients with diffuse than in those with nodular goiters, and was alike in nodular and internodular tissue. The patients with diffuse goiter were significantly younger than those with nodular goiter. Abolished TSH response to TRH was seen in 2 patients with negative T3 suppression tests. In another 2 patients impaired TSH response was associated with impaired suppressibility. In 13 patients with normal TRH tests, the suppression of uptake was normal in 8 and subnormal in 5. The results suggest that nodularity and functional autonomy may develop in non-toxic goiters. In some of these goiters the mass of autonomous tissue may be large enough to cause negative TRH tests, probably indicating hypersecretion of thyroid hormones, although not necessarily above the normal range.

Goiter

Human serum thyrotrophin level and response to thyrotrophin-releasing hormone in the aged.

170 healthy volunteers were investigated, and the clinical and biochemical conditions of selection specified. The fasting morning level of serum thyrotrophin (TSH) was determined in all volunteers and found unchanged within the age interval 18-94 years, independent of sex. This is in disagreement with results obtained by other investigators who found an increase of TSH in old age. The implications of the criteria of selection are discussed. Nycterohemeral rhythm was studied in 16 persons. Rhythmic variation was an inconstant finding, and the pattern in the young could not be distinguished from that in the old. The TSH response to thyrotrophin-releasing hormone (TRH) was determined in 53 persons of various ages and found unrelated to age. Nonetheless, the lowest responses were observed in the aged, but the difference was not statistically significant. Possible physiological interpretations of an unaltered TSH secretion in spite of an age-related decrease in thyroid function are discussed.

11-Hydroxycorticosteroids

131I-19-iodocholesterol scintigraphy of the adrenal cortex.

131-I-19-iodocholesterol scintigraphy of the adrenal cortex has been carried out in 26 patients. In 4 patients with normal adrenocortical function the tracer was equally accumulated on the two sides. In 7 patients with untreated Cushing's syndrome, bilateral uptake was found in 4 patients with bilateral hyperplasia whereas unilateral visualization was obtained in three cases of cortisol producing adenomas. The side localization was confirmed at operation. Eight patients had been operated for Cushings syndrome prior to the scintigraphy. Remnant adrenocortical tissue with negligible or subnormal function (4 patients) could not be visualized. Normo- or hyperfunctioning remnant tissue was visualized in 3 patients. One patient had recurrent hypercorticism due to metastases from a previously removed adrenocortical carcinoma; a single pelvic accumulation was seen, whereas several metastases in the abdomen and thorax were not visualized. Four patients with aldosteronism were investigated. Three had primary aldosteronism due to an adrenocortical adenoma. In two of these, the site of the adrenal lesion was localized pre-operatively. In the third patient, equal bilateral accumulation of iodocholesterol was seen even after suppression with dexamethasone. At operation a small tumour was found. In 1 patient with indeterminate aldosteronism both glands were visualized and at a second examination the uptake was equally suppressed by dexamethasone.

Adrenal Cortex