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Biomedical subjects

U Cordes

Publications and source records attributed to U Cordes.

At least 37 records · Page 2Linked to original sources

Islet-cell tumors: detection of small lesions with computed tomography and ultrasound.

Fifteen patients with a total of 16 islet-cell tumors 7-20 mm in diameter (average, 12 mm) were examined preoperatively by computed tomography (CT) and ultrasound. Seven out of 16 tumors were detected by CT and 9 out of 15 by ultrasound. Marked contrast enhancement was seen on dynamic CT scans following a bolus injection, while a circumscribed, hypoechoic mass was seen on ultrasound. Tumors of the tail of the pancreas and those outside the pancreas were difficult to detect. Ultrasound is recommended as the initial step for locating islet-cell tumors, followed by CT; angiography and transhepatic venous sampling should be restricted to tumors which are not detectable by other methods. Intraoperative ultrasound was successful in 3 patients and may facilitate the operative search.

Adenoma, Islet Cell↗

A comparison of the activity of the sympathoadrenal and adrenocortical system under inhalation anesthesia techniques.

Epinephrine, norepinephrine, ACTH and cortisol plasma levels as well as heart rate and blood pressure were studied in 32 patients undergoing ophthalmic surgery. Epinephrine levels rose significantly during nitrous oxide anesthesia and also during enflurane-nitrous oxide anesthesia, whereas they fell slightly during halothane-nitrous oxide anesthesia. Norepinephrine levels remained unchanged. ACTH and cortisol levels increased during all three types of anesthesia. During nitrous oxide and enflurane-nitrous oxide anesthesia, heart rate and blood pressure were elevated, halothane nitrous oxide anesthesia was associated with an increased heart rate but not with increased blood pressure.

Adolescent↗

[Imaging adrenergic tumours with 131J-meta-benzylguanidine].

Pheochromocytoma scanning using 131J-meta-benzylguanidine was done in one patient with metastasizing paraganglioma, one patient with multiple endocrine neoplasia type IIb. No activity of tumour tissue could be demonstrated in the patient with metastasizing paraganglioma, whereas the pheochromocytoma could be clearly defined in the patient with multiple endocrine neoplasia type IIa. The female with multiple endocrine neoplasia type IIb showed a suspect space-occupying lesion of the left adrenal using computed tomography. Pheochromocytoma could be excluded by 131J-benzylguanidine scanning, selective estimation of catecholamines in adrenal venous blood as well as the glucagon stimulation and clonidine suppression.

Adrenal Gland Neoplasms↗

[Ectopic hormone formation in multiple endocrine type IIa neoplasia (author's transl)].

A patient with high-grade osteoporosis had elevated levels of ACTH, cortisol and carcinoembryonic antigen (CEA). Computed tomography demonstrated enlarged adrenal glands. Despite intensive search no ACTH-producing tumour was found. A central Cushing's syndrome was thus possible, and a radiologically normal sella turcica made a microadenoma of the hypophysis a possibility. However, a one-time hypertensive crisis with elevated catecholamines raised the suspicion of an additional phaeochromocytoma and thus provided the first pointer to a multiple endocrine neoplasia. Bilateral phaeochromocytomas, discovered at adrenalectomy, as well as raised serum-calcitonin levels, strongly suggested coexistence of a C-cell carcinoma, which previously had not been demonstrated either by thyroid scanning or fine-needle biopsy. A total thyroidectomy revealed a multifocal and metastasizing C-cell carcinoma. On extraction it contained a high concentration of calcitonin, typical for a C-cell carcinoma. An unusual finding was of ACTH in extracts of both the C-cell carcinoma and the phaeochromocytoma. It was immunologically identical with the synthetic ACTH used as a standard.

Adrenal Gland Neoplasms↗

[Diagnosis of the site of insulinomas: percutaneous transhepatic portal vein catheterisations with selective blood sampling for hormone determination (author's transl)].

Percutaneous transhepatic portal vein catheterisation with blood sampling from the various areas of drainage, especially the pancreatic veins, was undertaken in seven patients with insulinoma to diagnose its site. In six patients measurement of serum-insulin levels revealed an abrupt rise in the vascular area later found to drain the area of the insulinoma. Insulin measurement in one patient with insulinoma in the head of the pancreas falsely indicated an islet-cell tumour in the region of the tail of the pancreas. C-peptide concentration in serum followed the concentration of insulin, but did not show such a marked rise. The method of percutaneous transhepatic portal vein catheterisation with selective blood sampling for the measurement of hormonal concentration was superior to ultrasound, computer tomography or coeliacography for determining the site of the tumour.

Adenoma, Islet Cell↗

Influence of norepinephrine on vessel geometry of the intact femoral artery in juvenile insulin-dependent diabetics-evidence of early diabetic angiopathy in central arteries.

A modified M-mode ultrasound echo system had been employed to study blood-vessel geometry of the intact femoral artery before and after Norepinephrine (NE) infusion. 14 patients with juvenile IDDM aged below 35 years and 11 healthy subjects participated in the study. In the diabetic group, wall distensibility (delta D/delta P) was reduced (p less than 0.01) at control conditions. After NE infusion, wall distensibility decreased in both groups (p less than 0.01). The decrease of wall distensibility is due to an increase in pulse pressure (delta P) (p less than 0.002) in the diabetic group and a reduction of pulsatile diameter (delta D) (p less than 0.02) in the normal group. Increased stiffening of the arteriaL wall after NE infusion with progressive reduction of wall strain (delta D/Dd) is the typical finding in the normal group. No change of wall strain was observed in the diabetic group. The functional alteration of the diabetic femoral artery may be described as diminished resistance of the arterial wall to the distending force of rising blood pressure.

Adolescent↗

[Blood-sugar-controlled insulin infusion systems for rapid adjustment of insulin-dependent diabetics (author's transl)].

Empirically obtained data could be verified and the basis for assessment of total insulin requirement, circadian distribution of insulin doses and contents of single insulin portions of old and delayed-action insulin could be established in a prospective study in 13 insulin-dependent diabetics. Assessment of insulin requirements was done after a 36-hour investigation period with the artificial endocrine pancreas using standardised conditions. Readjustment was complemented by dietary advice and rearrangement of total calory input and distribution of carbohydrates during the day. Therapeutic success in 55 patients justifies this procedure. Adjustment of insulin-dependent diabetics was thus obtained more rapidly, better and at less cost.

Adolescent↗

The effects of equal caloric amounts of xylitol, sucrose and starch on insulin requirements and blood glucose levels in insulin-dependent diabetics.

Xylitol has been suggested as a potentially useful sweetener in the diabetic diet. In 14 insulin-dependent diabetics a standard diabetic diet regimen was compared with diets in which starch was isocalorically exchanged in the breakfast meal by either 30 g xylitol or 30 g sucrose. Insulin requirement and blood glucose were measured using a glucose-controlled insulin infusion system. The results following breakfast with xylitol were similar to those after starch breakfasts. Sucrose, in contrast, induced a greater post-prandial rise in blood glucose levels despite counter-regulation by the glucose-controlled insulin infusion system. Insulin requirement after sucrose significantly exceeded (p less than 0.01) that after xylitol or starch during the first 60 min and 2 h respectively. No short-term side effects of xylitol were found.

Adult↗

[Localization of islet cell tumors using sonography, computed tomography, arteriography and selective transhepatic venous sampling for hormone assay (author's transl)].

Of 29 patients examined operation revealed a malignant tumor in 9 and a benign insulinoma in 18, 2 insulinomas were not found. The problems of preoperative tumor localization were limited to small insulinomas (size 7-35 mm). Ultrasound detected all of 3 insulinomas as low echogenic structures (size 7, 8, 17 mm). Computed tomography demonstrated 4 of 5 insulinomas (size 7, 8, 15, 17 mm) due to contrast enhancement following bolus injection. Arteriography localized 12 of 18 insulinomas preoperatively and 14 of 18 retrospectively. Selective transhepatic venous sampling for insulin assay identified 7 of 8 tumors. Real-time ultrasound and dynamic CT are promising in the diagnostics of insulinomas over 7 mm and should precede arteriography. Selective transhepatic venous sampling as the last diagnostic step is a major procedure and most specific, but not always without problems in interpretation.

Adenoma, Islet Cell↗

[The effect of enflurane anaesthesia and operation on the sympathoadrenal and adrenocortical system (author's transl)].

The effect of enflurane anaesthesia on the sympathoadrenal system, the hypothalamic-hypophyseal-adrenocortical system, and on the circulatory system was investigated in patients undergoing ophthalmic surgery. Blood concentrations of adrenaline, noradrenaline, ACTH, cortisol, and arterial blood pressure and heart rate were measured in 10 patients 30 min after premedication (I), 3-5 min after surgical incision (II), 20 or 45 min after surgical incision (III) and in 7 of 10 patients 10-15 min after extubation (IV). After conventional induction anaesthesia was maintained with enflurane (1.5-2.0%), combined with N2O/O2 2:1, and intermittent relaxation. Plasma adrenaline, ACTH, cortisol and heart rate increased significantly during operation, while plasma noradrenaline and blood pressure did not change significantly. Thus enflurane anaesthesia could not completely inhibit the increased activity of sympathoadrenal and hypothalamic-hypophyseal-adrenocortical system caused by surgical stress.

Adolescent↗

[Mechanomyography - results in a normal population and in patients with thyroid dysfunction (author's transl)].

Isometric contraction of the adductor pollicis by stimulating the ulnar nerve was determined in 20 normal adult subjects. We measured mechanical latency, electro-mechanical latency, contraction time, time to half relaxation and isometric twitch force. Besides that we registered the compound muscle action potential and the nerve conduction velocity. The median nerve was used to elicit the nerve action potential and to determine conduction velocity and relative refractory period. In 6 pat. with hypothyroidism and in 7 pat. with hyperthyroidism the above mentioned parameters were measured. There was a significant change concerning contractile properties, i.e. muscular contraction became slower in hypothyroidism and faster in hyperthyroidism as compared to values obtained in the control group. The isometric twitch force was reduced in both conditions. To assure the close relationship between thyroid hormone (L-thyroxin) and muscle contraction a group of patients who have undergone thyroidectomy was investigated in the same way. Muscle and nerve parameters were determined during a levothyroxin-therapy and in a period without any treatment. The same phenomenon was observed, i.e. reduction of twitch velocity in the hypothyroid state. The twitch force was not reduced in this group. The close relationship between thyroid hormone and contractile properties allows a discrimination between hypo-and hyperthyroid state and a control of thyroxin substitution.

Electric Stimulation↗

[Sympathetic activity and blood pressure in normotensive and hypertensive patients undergoing ophthalmic surgery under electrostimulation anaesthesia (author's transl)].

Plasma adrenaline, noradrenaline, blood pressure and heart rate were determined in 10 normotensive and 10 hypertensive patients undergoing ophthalmic surgery under electrostimulation anaesthesia. Venous blood samples for the determination of the catecholamines by a spectrofluorometric method were taken 30 min after premedication and 45 min after surgical incision. The catecholamine concentrations showed no significant differences neither by comparing the normotensive patients with the hypertensive patients nor by comparing the values during operation with them after premedication in each group. However, in the hypertensive patients blood pressure showed a higher increase during operation than in the normotensive patients.

Aged↗

[Effect of calcium dobesilate on permeation of plasma proteins in diabetic patients].

The effect of six months of treatment with 750 mg calcium dobesilate on sedimentation rate blood count, cholesterol, triglycerides, platelet aggregation factor, total protein, electrophoretic distribution of serum protein concentrations, and kinetics of intravenous albumin marked with 131I was established in 35 diabetics with a mean duration of diabetes of 9.8 years. There was significant intravascular retention of 131I albumin and significant increase of serum albumin, beta-globulins and total protein after treatment. The other parameters remained unchanged. The results are interpreted as evidence of lowering of the increased transcapillary permeability within the vascular system seen in diabetics.

Aged↗