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Biomedical subjects

U Krause

Publications and source records attributed to U Krause.

At least 181 records · Page 10Linked to original sources
PubMed1986

The effect of cryopreservation on hormone secretion in vitro and morphology of human parathyroid tissue.

The hormone secretion from human parathyroid tissue autografted after cryopreservation can fail frequently. In this study we examined the effects of the cryopreservation procedure on parathyroid hormone secretion in vitro and the viability of parathyroid cells to identify possible reasons for graft failure. Cryopreservation did not affect quantitative parathyroid hormone release from single-cell suspensions or its calcium-and magnesium-dependent regulatory mechanisms. However, morphometric analysis of thawed 1 mm3 graft particles showed various degrees of necrosis when compared with fresh grafts. Thus partial necrosis of cryopreserved tissue appears to contribute to poor transplantation results compared with immediate replantation of fresh parathyroid tissue. This limitation can be overcome by increasing the number of frozen graft particles used for autotransplantation. The percentage of viable cells should be accounted for by morphometric analysis and this factor used when calculating the number of graft particles employed.

Cell Survival↗
PubMed1985

Comparison of 131I-metaiodobenzylguanidine scintigraphy with urinary and plasma catecholamine determinations in the diagnosis of pheochromocytoma.

In a retrospective study of 31 patients with suspected pheochromocytoma we examined the preoperative results of 131I-metaiodobenzylguanidine (131-I-MIBG) scintigraphy and a fluorimetric urine catecholamine determination test. An additional radioenzymatic plasma catecholamine determination test was performed in 25 patients. In 14 of the 31 patients the diagnosis of pheochromocytoma was later histologically confirmed. In the remaining 17 patients the suspected diagnosis was finally rejected after a clinical decision had been made on the basis of clinical history, symptoms, laboratory and imaging tests. 131-I-MIBG scintigraphy apparently had a very high specificity (no false-positive results among the patients with rejected diagnosis), but showed the least sensitivity (3 of 14 tumours were not detected). Urine catecholamines showed two false-negative and three false-positive results. Plasma catecholamines had the highest sensitivity and gave only one false-positive result. Because of its high pathognomonic value 131-MIBG scintigraphy can be helpful not only for localization, but also for confirmation of diagnosis when catecholamine determination tests are contradictory. On the basis of our experience with false-positive results after interfering medication therapy, urine and plasma catecholamine determination tests should only be carried out after purification with thin layer chromatography or high performance liquid chromatography.

3-Iodobenzylguanidine↗
PubMed1985

Pulsatile gonadotropin-releasing hormone therapy in male patients with Kallmann's syndrome or constitutional delay of puberty.

The response to low-dose pulsatile gonadotropin-releasing hormone (GnRH) therapy was tested in three hypogonadotropic hypogonadal male patients and a boy with delayed puberty showing different luteinizing hormone responses (delta LH) to test doses of 25 micrograms GnRH intravenously before treatment. Four male patients, 16 to 20 years of age, three with Kallmann's syndrome and one with idiopathic delay of puberty, received 2 micrograms GnRH subcutaneously every 2 1/2 hours for 3 months by the use of the Zyklomat pump (Ferring GmbH, Kiel, FRG). In two patients with Kallmann's syndrome and decreased delta LH, serum testosterone did not increase during treatment, even after increasing the dosage and changing the route of administration (4 micrograms subcutaneously or 8 micrograms intravenously every 2 1/2 hours for 4 weeks with every dosage). The third patient with Kallmann's syndrome and the boy with delayed puberty, both with normal delta LH, presented normal serum testosterone after 3 months of subcutaneous low-dose treatment. The different responses to a GnRH test dose corresponding to the response to pulsatile GnRH therapy probably reflect different degrees of maturation of the pituitary gonadotrophs.

Eunuchism↗
PubMed1985

Effect of lens implants on iris fluorescein angiography and the iris pigment layer.

Fourteen eyes underwent cataract operation and implantation of an iris fixated (Medallion) pseudophakos. Eleven had an uncomplicated per- and post-operative course (group 1), 3 had a subluxation of the lens implant (group 2). The control group (group 3) consisted of the 14 contralateral eyes from group 1 and 2. Two cadaver eyes had a similar lens implanted (group 4). Groups 1-3 were investigated by bilateral simultaneous iris fluorescein angiography and retroiridal stereo transillumination photography. In group 1, one case with pupillary and diffuse semiperipheral leakage areas was observed, in a clinically healthy eye 15 months after the operation. An other one had some leakage at the pupillary border, but not in the area of contact with the loops. Rubbing between iris surface and some parts of the lens did not provoke local leakage. No new vessel formation was found. Pigment layer defects were observed in every operated eye, but no leakage was related to them except in the two pupillary areas mentioned. Mayor pigment defects did not progress in a quiet eye. The iris seems to be to some degree resistant to contact with the parts of the intraocular lens implant.

Adult↗
PubMed1985

Preliminary results with the clonidine suppression test in the diagnosis of pheochromocytoma.

23 patients presenting with symptoms of pheochromocytoma were subjected to the clonidine suppression test. In 6 patients, in whom a pheochromocytoma was surgically approved later on, norepinephrine was not suppressed by clonidine. 17 patients in whom a secondary form of hypertension could be excluded by other diagnostic measures showed a marked decrease of plasma norepinephrine. Apart from drowsiness, no adverse side effects were observed. In our hands, the clonidine test proved as a safe and specific test in the diagnosis of pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1985

Selective blood sampling in adrenal hypertension.

Selective venous blood sampling was performed in 89 patients with hypertension (14 pheochromocytoma, 10 Conn's syndrome, 8 Cushing's disease, 57 essential hypertension). We looked for diagnostic criteria and the valuability of blood sampling from the adrenal veins in such diseases. Defining a norepinephrine concentration of more than 8,000 ng/l as pathological, we had an accuracy of 94.6%. Defining an aldosterone concentration of more than 1,400 pg/ml as pathological, we had an accuracy of 97.4%. In Cushing's disease this method was not very helpful due to overlapping results.

Adrenal Gland Diseases↗
PubMed1985

Crohn's disease. A long-term study of the clinical course in 186 patients.

A series of 186 patients treated for Crohn's disease during the period 1956 to 1968 has been followed up in 1970, 1975, and now in 1983. Among 173 patients operated on there were 89 recurrences (52%). After a follow-up time greater than 14 years (mean, 18 years) 'radical' resections at the first operation gave a lower recurrence rate (31%), fewer reoperations, and a better quality of life compared with non-'radical' resections (recurrence rate, 83%). The quality of life estimated for all patients alive in 1983, 152 patients, was good in 89%; 8.6% had moderate subjective symptoms, and 2.6% had pronounced subjective symptoms. With an increasing follow-up time there was no decrease in the patients' quality of life. Ileorectal anastomosis did not give very good results; proctocolectomy and ileostomy, however, gave good results. Regular investigation of all patients is of vital importance to give them a good quality of life.

Adolescent↗
PubMed1985

[Sarcoidosis involvement and adenocarcinoma of the stomach].

A 59-years old woman showed 5 years after the diagnosis of a sarcoidosis of stage II--III according to Wurm and Reindell an abdominal symptomatology in the sense of an ulcerous disease. Radiological, endoscopical and bioptical examinations revealed a small contraction of the antrum, an ulcus at first diagnosed as benign and an adenocarcinoma. In the resected part of the stomach were found noncaseating granulomas with Epithelioid cells and Giant cells as well as the adenocarcinoma. 1 1/2 years after partial resection of the stomach (B II) a recurrence of the carcinoma near the anastomosis and metastases in the lymphonoduli of the abdomen were found by autopsy. Thoracic of abdominal manifestations of the sarcoidosis could no longer be demonstrated.

Adenocarcinoma↗
PubMed1984

Long-acting and selective suppression of growth hormone secretion by somatostatin analogue SMS 201-995 in acromegaly.

In 6 of 7 acromegalic patients a single subcutaneous injection of 50 micrograms of a new octapeptide somatostatin analogue (SMS 201-995) reduced serum growth hormone (GH) from 30 +/- 12 ng/ml to 1.4 +/- 0.4 (mean +/- SEM). Serum GH remained below basal concentration for 9 h. In the remaining patient who had very high basal preprandial serum GH, SMS 201-995 produced a reduction in serum GH of only 20%. Plasma glucose concentrations were increased to the upper limits of the normal range when a high-carbohydrate meal was consumed 2 h after injection. In non-diabetic patients plasma glucose did not exceed 129 mg/dl. The 40% decrease in plasma glucagon, which lasted for 7 h after SMS 201-995 injection, was not statistically significant. No side-effects and no rebound phenomenon were observed. These results suggest that SMS 201-995 may be the first somatostatin analogue suitable for the clinical management of acromegaly.

Acromegaly↗
PubMed1984

Regional differences in the effect of pargyline on dopamine concentrations in the rat hypophysis.

Dopamine concentrations were estimated in different regions of the infundibular-pituitary system of the rat. The highest values were found in the pituitary stalk where they are comparable to the concentrations in the striatum, and higher than in the median eminence. In the anterior lobe the dopamine (DA) concentrations of the upper pole (10% of the lobe tissue) were 2-5 times higher than in the rest of the lobe. Anterior lobe DA was significantly higher in rats about 6 months old than in rats about 3 months old. After inhibition of MAO, the DA concentrations in the isolated neural lobe (NL) were more than doubled. In contrast there was no increase in the DA concentrations of the intermediate lobe, an observation which is in agreement with our previous finding that DA synthesis in the intermediate lobe after electrical stimulation of the pituitary stalk is much slower than in the neural lobe. Pargyline treatment caused an increase in the DA concentrations in the anterior lobe by about 150%. This rise (together with a DA increase in the stalk-infundibulum) may be related to the decrease in circulating prolactin which occurs in pargyline treated rats.

Aging↗
PubMed1984

Development of individual insulin infusion profiles for open loop infusion systems.

A computer controlled syringe-type insulin infusion pump storing up to 254 different infusion rates, eight different meal programs and two different basal rates automatically changeable during 24 h in EPROM was used for insulin infusion applying a wavy step profile. This profile approaching the physiological postprandial insulin secretion of the B-cell was calculated by an algorithm following the biphasic insulin secretion model proposed by E. Cerasi . The computer program for the open loop infusion device simulated the feed-back structure of a closed loop insulin secretion control by an algorithm based upon a theoretical postprandial blood sugar profile. Fifteen unstable juvenile onset insulin requiring diabetics could be well controlled after two to three days of an intravenous open loop insulin infusion program. The programs consisted of two constant basal rates and superimposed wavy step profile programs activated at the beginning of each meal. The preabsorptive bolus or cephalic phase was an additional tool both for improved postprandial blood sugar control and further reduction of insulin consumption. The programmable insulin infusion device proved as a valuable tool for the study of a sophisticated insulin infusion profile suitable as well for open loop as for closed loop insulin infusion systems.

Adult↗
PubMed1984

Effect of cimetidine on basal and histamine-induced secretion of parathyroid hormone in vitro.

The effect of cimetidine on basal and histamine-induced PTH secretion was tested using single cell suspensions obtained from (a) primary parathyroid adenomas, and (b) secondary hyperplastic parathyroid tissue from patients undergoing chronic hemodialysis. The histamine-stimulated hormone secretion was dose-dependent. Cimetidine suppressed both basal and histamine-stimulated hormone secretion. Within the therapeutic range the suppressive effect was identical for adenoma and hyperplasia. Both adenomata and secondary hyperplastic glands showed a histamine H2-receptor-related response. The role of histamine in the pathogenesis of hyperparathyroidism is not quite clear so that the possible benefits of cimetidine for medical treatment of primary and secondary hyperparathyroidism will have to be proven by careful clinical trials.

Adenoma↗