Biomedical subjects

J Beyer

Publications and source records attributed to J Beyer.

At least 289 records · Page 16Linked to original sources

PubMed1991

Prevalence of antibodies to recombinant hepatitis C virus protein C100-3 and of elevated transaminase levels in blood donors from Northern Germany.

Antibody to recombinant hepatitis C virus protein C100-3 (anti-C100-3) was assayed by a first generation enzyme-linked immunosorbent assay (ELISA; Ortho Diagnostics) in 116,700 blood donors who had not been tested before. Total prevalence of repeatably positive donors was 0.72% (n = 842). Prevalence increased significantly from 0.42% at 18-27 years of age to 1.26% at greater than or equal to 58 years. Donors with elevated serum transaminase levels were significantly more often anti-C100-3 positive, but in 98.7% of donors with current or 99.1% with previous transaminase elevations, anti-C100-3 was not found. Elevated transaminases were more often associated with positive anti-C100-3 in females than in males. However, in the total donor population no significant differences of anti-C100-3 prevalence were found between the sexes. During follow up at three subsequent blood donations, 1.08% of donors were positive at least once, but only 0.48% were consistently positive. The cutoff of the Ortho ELISA was not in the minimum of the frequency distribution between positive and negative samples, but far within the range of the negative signals, i.e. the test is likely to produce a significant number of false-positive results. In retesting positive samples with two ELISAs from other producers only a 22% to 65% agreement was found. In a low prevalence group such as German blood donors, the first generation ELISAs for anti-C100-3 produced more false than specific positive results. Most donors with elevated alanine aminotransferase (ALT) are anti-C100-3 negative.

Adolescent↗

PubMed1991

Relationship of eye muscle antibodies with HLA phenotypes and thyroid-stimulating immunoglobulins in endocrine orbitopathy.

The relationship between endocrine orbitopathy and Graves' hyperthyroidism is still not clarified. The purpose of this study was to elucidate the incidence of eye muscle antibodies and the relationship with HLA phenotypes and thyroid antibodies in 65 patients with endocrine orbitopathy classes 1-5. Both bovine and abdominal muscles were used as antigens in ELISA systems in which IgG and IgM antibodies were assayed. Before starting the immunosuppressant therapy, 46/65 patients (71%) showed a positive result for eye muscle antibodies. Those patients with an active disease had such antibodies more frequently. Where the ophthalmopathy was of recent onset IgM antibodies were found, whereas patients with chronic disease were mostly IgG-Ab positive. No association was found either with HLA phenotypes (B8, DR3) or with antibodies directed against thyroglobulin, thyroid microsomes, and the TSH receptor measured as thyroid-stimulating immunoglobulins. Furthermore, there was no correlation between ophthalmopathy class and optic muscle antibody-binding activity. There was no relation between the degree of exophthalmos and eye muscle, thyroid-stimulating, antithyroglobulin, or antithyroid microsomal antibodies. These results suggest that, although very closely related, endocrine orbitopathy and Graves' hyperthyroidism are separate, organ-specific autoimmune diseases.

Adolescent↗

PubMed1991

Studies on facial temperature rise and involvement of serotonin in the respiratory stimulation by CRH.

Following an intravenous injection of 100 micrograms hCRH a facial flushing can frequently be observed along with respiratory stimulation. Both effects can be mediated by a common transmitter. Serotonin is well known to produce facial flush as well as to modulate respiration. In order to clarify is serotonin is a common mediator for facial flush and respiratory stimulation after i.v. application of hCRH, we studied the time course of facial skin temperatures and respiratory stimulation after intravenous injection of 100 micrograms hCRH in 10 healthy subjects. Furthermore, we measured respiratory stimulation after i.v. administration of 100 micrograms hCRH in 10 healthy subjects pretreated with the serotonin antagonist cyproheptadine. Facial skin temperatures reached maximum levels 9 min after CRH administration and remained raised for more than 60 min. Respiratory stimulation occurred within the first minute after CRH administration and reached a maximum during the second minute, but could no longer be observed after 10 min. Serum serotonin levels did not change after CRH stimulation in doses up to 3 micrograms/kg body weight), and cyproheptadine did not abolish the respiratory stimulation effect of hCRH in a dosage sufficient to suppress CRH.-induced cortisol secretion.

Adult↗

PubMed1991

Thyrotropin-releasing hormone has stimulatory effects on ventilation in humans.

Thyrotropin-releasing hormone (TRH) stimulates pituitary thyrotropin synthesis and release and also regulates autonomic nervous system functions by acting as a neuromodulator and neurotransmitter. In experimental animals a stimulation of ventilation by thyrotropin-releasing hormone was shown when applied at central nervous system sites that affect respiratory motor output. It was the goal of our study to investigate the respiratory properties of thyrotropin-releasing hormone on basal and stimulated (i.e. CO2-rebreathing) conditions following systemic thyrotropin-releasing hormone application in healthy humans. Thyrotropin-releasing hormone (200 micrograms, 400 micrograms intravenous) initiated a rapid short lasting rise of minute volume, ventilatory air-flow and alveolar oxygen tension under steady state breathing (P less than 0.001). Breathing frequency was less affected, heart rate rose concomitantly (P less than 0.001). While breathing with increasing concentrations of carbon dioxide, minute volume was higher under thyrotropin-releasing hormone than under placebo alone. Further effects (e.g. nausea, dizziness, palpitations) mostly appeared later than respiratory changes and thus may not be responsible for their initiation. Our findings prove systemic thyrotropin-releasing hormone to be a strong respiratory stimulant in man. Response in respiratory output was also accompanied by central nervous system-effects (e.g. dizziness, restlessness, augmented vigilance). The mode of thyrotropin-releasing hormone effects on respiration after peripheral administration is still speculative. An augmented sympathetic output or a direct receptor mediated action at central nervous system sites may be responsible, while a peripheral effect cannot be excluded.

Adolescent↗

PubMed1991

Potential clinical use of an adrenergic/cholinergic agent (HP 128) in the treatment of Alzheimer's disease.

A novel compound designated HP 128, which manifests adrenergic and cholinergic properties, was administered for 10 days to patients with Alzheimer's disease in a double-blind, placebo-controlled trial. All patients who entered the trial had previously failed to respond to a structurally related cholinesterase inhibitor without adrenergic properties (HP 029). The primary purpose of the study was to assess the safety and tolerance of HP 128. Efficacy measures were obtained to generate hypotheses for possible future studies. In the dosage range examined, HP 128 was safe and well tolerated. Effects on clinical measures of dementia severity were equivocal.

Aged↗

PubMed1991

Graves ophthalmopathy: role of MR imaging in radiation therapy.

Twenty-three patients with Graves ophthalmopathy who underwent radiation therapy were monitored by means of magnetic resonance (MR) imaging. T2 relaxation times of extraocular muscles and orbital fat, areas of extraocular muscles, and degree of exophthalmos were measured by means of MR imaging at the beginning, at the end, and 3 months after completion of radiation therapy. As a result, patients with primarily elevated T2 times of extraocular muscles showed a better therapy response regarding muscle thickening than patients with primarily normal T2 times. Elevated T2 times, which probably represent acute inflammatory changes, were markedly decreased at the end of therapy. Therefore, quantitative MR imaging favors the choice of anti-inflammatory therapy regimens in patients with elevated T2 times of extraocular muscles. However, the clinical response (activity scores) to the low-dose treatment protocol that was used did not correlate well with primarily elevated T2 times. Furthermore, T2 times increased again after cessation of therapy. Whether a higher radiation dose or a different fractionation scheme leads to better results must be clarified by means of further study.

Adult↗

PubMed1991

Unaltered pulsatile and circadian TSH release in euthyroid patients with endemic goitre.

To evaluate the pathophysiological role of TSH in goitrogenesis we investigated pulsatile TSH secretion in 11 patients with a non-toxic goitre and in 11 healthy controls. Thyroid volume was 40 +/- 10 ml in the goitre group and 15 +/- 4 ml in the controls as measured by ultrasound. Blood was sampled continuously via an indwelling venous catheter at 10-min intervals over 24 h. Neither the mean 24-h serum TSH levels (goitre 1.1 +/- 0.5 vs controls 0.9 +/- 0.4 mU/l) nor the nocturnal surge of TSH were significantly different between the two groups. The average of the TSH pulse frequency (goitre 10.8 +/- 3.7 vs controls 9.6 +/- 3.5 pulses/24-h) and of the TSH pulse amplitude (goitre 0.4 +/- 0.2 vs controls 0.3 +/- 0.1 mU TSH/l) as analysed by DESADE programme (detection of secretory activity by discrete deconvolution) did not differ in the two groups. Furthermore, there was no correlation between the volume of the thyroid gland and the dynamics of the TSH secretion. We conclude that our data do not suggest a relevant pathophysiological role of TSH secretion in the development of non-toxic goitre in man.

Adult↗

PubMed1991

[Clinical use of peripheral stem cells for autologous transplantation].

Peripheral blood derived hematopoietic stem cells (PBSC) have been transplanted successfully to eight patients suffering from different malignancies. The separations were started during chemotherapy-induced cytopenia and large volumes of peripheral blood were processed. Using this separation concept, it was possible in all cases to obtain the stem cell amount necessary for hematopoietic reconstitution.

Blood Cell Count↗

PubMed1991

Circadian variation of basal and postprandial insulin sensitivity in healthy individuals and patients with type-1 diabetes.

The circadian variation of basal and postprandial plasma glucose and insulin levels was analyzed in 10 healthy individuals and 10 type-1 diabetic patients treated with a glucose-controlled insulin infusion system. In both groups the postprandial glycemic response to identical low caloric mixed meals ingested at 8.00 am, 1.00 pm, and 6.00 pm increased significantly in the course of the day. In contrast to findings in conventional insulin therapy mean postprandial insulin requirements of the diabetic patients increased from 8.5 +/- 3.0 IU for breakfast to 9.1 +/- 2.0 for lunch and 10.9 +/- 3.0 for dinner (p less than 0.01). Repeated studies with different test meals showed that in the diabetic patients the circadian deterioration of carbohydrate tolerance was reduced after a fibre rich meal with low glycemic effect and insulin requirements. In the healthy subjects basal insulin levels at 8.00 am were 35% higher than at 1 and 6.00 pm (p less than 0.01). Basal insulin requirements of the diabetic patients increased significantly from a night value of 0.7 IU/h to 1.18 IU/h during the early morning and remained constant throughout day time. We conclude that circadian changes in postprandial carbohydrate tolerance are independent from the endogenous rhythmics of basal glucose metabolism. In diabetic patients the circadian pattern of postprandial responses is substantially determined by exogenous factors like diet composition caloric intake and therapeutic regimen.

Adult↗

PubMed1991

[Studies on the influence of releasing hormones TRH and CRH on respiratory regulation].

Patterns of neuroanatomical distribution of Thyrotropin-releasing hormone (TRH) and Corticotropin-releasing hormone (CRH) and of their receptors in brain areas of humans and of animals suppose a regulating function of both peptides on regulation of respiration. In experimental animals TRH induces rhythmical and synchronous firing of defined neurons of nucleus tractus solitarii. In fetal sheep, endogenous and exogenous CRH promotes maturation of breathing rhythm genesis. In own human studies we demonstrated a modulation of respiration in healthy test-subjects - predominantly a stimulation of respiration - by systemic TRH and CRH. This effect persists also during hypercapnia, as we showed in patients and in 12 healthy test subjects while re-breathing CO2: when compared to placebo, CRH i.v. (200 micrograms. Bissendorf, Hannover, FRG) induces a significant (p less than 0.0001) shift of the ventilatory response curve to the left (petCO2 vs minute volume). Stimulation of respiration by CRH is independent of activation of the pituitary-adrenal axis. At present two analogues of CRH are available for application in humans (as a diagnostic of endocrinological disorders): human CRH and ovine CRH. Both analogues are comparably effective in stimulation of ventilation although sequence of effects is different in both analogues. We also evaluated the effect of CRH in 10 aged patients who were under prolonged respirator therapy after major abdominal surgery; both human and ovine CRH (100-200 micrograms i.v.) induced a profound and long lasting stimulation of ventilation under assisted respirator therapy. Vigilance was also markedly increased in all patients and thus was of therapeutic value. CRH also has a potential to alter sleep architecture in healthy and in diseased persons.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1990

[Computer-assisted diabetes therapy--a challenge for modern medicine].

By the use of computers in the therapy of diabetes new diagnostic and therapeutic possibilities are brought about. The computers open the possibility for a comprehensive data seizing, evaluation of the stored material and possibilities of various abilities for demonstration. Moreover, it becomes possible to regulate the therapy more subtly with the help of self-adapting programs and in its consequence to render it more effective than the own management of therapy is able to do it. This manifests itself significantly in badly or only moderately stabilised diabetics. In very well educated and trained diabetics even the superiority of the management of the computer becomes visible. Here this can no more be shown in the improvement of the stabilisation of diabetes which can no more be improved without risks for the patient. In these patients it is the reduction of the frequency of hyperglycaemia, by means of which can be shown that the stabilisation of diabetes in diabetics who were well stabilised already before can still be improved by the computer therapy. In addition to this the computer seems to cause further positive effects on the learning behaviour of the diabetics.

Blood Glucose↗

PubMed1990

The influence of penbutolol and placebo on blood sugar levels and insulin consumption in the glucose-controlled insulin infusion system ("artificial endocrine pancreas").

The aim of the study was to investigate the influence of 40 mg of the beta-blocker penbutolol (Betapressin TM; Hoechst Ltd., Frankfurt/Main) in comparison to placebo on the insulin consumption on the blood sugar profile in twelve insulin-dependent diabetes (IDDM) patients. The patients were treated with penbutolol and placebo for a period of three days, and then were examined with the help of the glucose-controlled insulin infusion system. The blood sugar profile and insulin consumption over a 24 hour period was not affected by either penbutolol or placebo, nor could any changes be measured in these parameters when measured after food intake. After a submaximal exercise load on the bicycle ergometer (1 watt per kg body weight) following an evening meal, no difference could be observed between penbutolol and placebo in the above-mentioned parameters. The same was also true for hormonal parameters as STH, ACTH, cortisol, and catecholamines. These findings demonstrated that medication of penbutolol over a three-day period has no influence on the baseline blood sugar profile and insulin consumption or on insulin consumption after food intake during rest and physical exercise.

Adolescent↗

PubMed1990

[Long-term results following surgical treatment of islet cell adenoma].

To evaluate the long term results after operation of islet cell adenomas we analyzed our own patient material from 1.1.1967 to 30.11.1988. During this time we operated 43 patients with islet cell tumors. 36 patients had benign adenomas. After a medium time of 6.7 years we analyzed the outcome of 33 patients. Only one out of 29 patients with a solitary adenoma had a recurrence of the disease. Two patients after pancreas resection had diabetes mellitus. In contrast to this only one out of four patients with multiple adenomas was free of symptoms. One patient had diabetes mellitus. In two patients five operations were necessary up to now, nevertheless one of the patients had persistent hypoglycaemic symptoms. These results show that the most important factor in therapy of patients with islet cell tumors is the recognition and complete removal of multiple adenomas.

Adenoma, Islet Cell↗

PubMed1990

[Central nervous appetite regulation: mechanisms and significance for the development of obesity].

This review focuses on neurotransmitter and neuropeptide actions on food ingestion, as well as on some of the mechanisms that may lead to the development and maintenance of obesity. In particular, the role of hypothalamic amines (catecholamines, serotonin) in appetite control is described. Thus, hypothalamic noradrenaline appears to stimulate food intake, while an enhanced brain serotonergic neurotransmission leads to a suppression of food ingestion, preferentially of carbohydrate intake. The involvement of brain serotonin neurons in appetite control is most attractive, since serotonin synthesis and release is readily affected by either precursor loading (i.e., 1-tryptophan) or pharmacological manipulation (e.g., drugs such as fenfluramine or fluoxetine). Recent data now suggest that at least a subgroup of obese patients is characterized by a disturbed serotonergic neurotransmission, thus exhibiting behaviors such as carbohydrate craving. Among neuropeptides involved in appetite control, the most attractive candidate appears to be corticotropin-releasing hormone which is released by neurons of the paraventricular nucleus and produces a stress-like activation of the organism, and has a strong appetite-suppressant effect.

Appetite↗

PubMed1990

Long-term observation of endocrine ophthalmopathy and retrospective appraisal of therapeutic measures.

The course of endocrine ophthalmopathy was investigated on the basis of clinical and biochemical parameters and in relation to different therapeutic strategies. A retrospective appraisal was made of 297 patients (44 +/- 14 yr, 249 women) with inclusion of anamnestic and clinical data as well as the results of computer tomography. At the beginning of therapy, 253 patients were hyperthyroid, 36 were euthyroid and eight were hypothyroid. The HLA typing carried out in 89 patients showed the phenotypes B8 and DR3 in 32% and 42% of the cases, respectively. Raised microsomal antibodies were present in 56% of the patients and there were raised thyroglobulin antibodies in 19%. Sixty-three % of the patients received immunosuppressants in the course of therapy: glucocorticoids in all cases, nonsteroid immunosuppressants in 15%. Eight % of the patients were irradiated retrobulbarly. The inflammatory parameters could be favorably affected, whereas eye muscle involvement and bulbar protrusion proved to be more resistant to therapy. In patients with combined immunosuppressant therapy or steroids + retrobulbar radiation, there were unequivocal successes with regard to the proptosis, vision and intraocular pressure. None of the strategies applied constitutes an optimal treatment with regard to the long-term course. Following therapy, there is an improvement of endocrine ophthalmopathy, but not complete healing.

Adolescent↗

PubMed1990

Studies on the Origin of (-)-alpha-Bisabolol and Chamazulene in Chamomile Preparations; Part I. Investigations by Isotope Ratio Mass Spectrometry (IRMS).

IRMS was used to determine the delta (13)C-and deltaD-values of dried plant material and essential oil fractions of CHAMOMILLA RECUTITA and VANILLOSMOPSIS ERYTHROPAPPA and of isolated components thereof. Both plants turned out to follow the same C (3) photosynthetic pathway. The carbon isotope ratios ( delta (13)C-values) of chamomile-derived bisabolol ranged from -32 per thousando to -30 per thousand; the corresponding deltaD-values varied between -240 per thousand and -205 per thousand. VANILLOSMOPSIS bisabolol differed significantly, with delta (13)C-values of approximately -27 per thousand, and a deltaD-value of about -175 per thousand. In addition, chamazulene of chamomiie was characterized by a delta (13)C-value of -31 per thousand, whereas in chamazulene from ACHILLEA MILLEFOLIUM lower carbon discrimination was found (delta (13)C = -30 per thousand). The delta (13)C-values allowed us to detect adulterations of chamomiie preparations. The isolation of bisabolol, a main ingredient of these preparations, and subsequent IRMS analysis is much more tedious than GC/IRMS, which makes it possible to determine the carbon isotope ratio of bisabolol without prior isolation. Only one commercial chamomiie preparation was completely free of non-chamomile admixtures. Our investigations clearly demonstrate that admixtures of natural compounds can be detected in chamomile oil and chamomile preparations even if there is no difference in the photosynthetic mechanism of the corresponding plants.

Journal Article↗

PubMed1990

Urinary glycosaminoglycans in Graves' ophthalmopathy.

An increased accumulation of glycosaminoglycans (GAG) in retrobulbar tissues has been reported in patients with thyroid eye disease. We examined the quantitative urinary GAG excretion in 101 patients with Graves' ophthalmopathy of different classes, 36 patients with Graves' hyperthyroidism without ophthalmopathy, 14 patients with toxic nodular goitre and 103 control subjects. Glycosaminoglycans were isolated from 24-h urine collections by precipitation with cetylpyridinium chloride and ethanol followed by photometrical quantification of hexuronic acids after reaction with carbazole. In comparison with the control group (15.8, 10.4, 21.6 mg/24 h; median, 25th, 75th percentile) a significant (P less than 0.005) elevation of urinary GAG excretion was found in patients with ophthalmopathy (19.2, 12.2, 28.7 mg/24 h), whereas patients with Graves' hyperthyroidism and no ophthalmopathy (16.2, 11.9, 21.7 mg/24 h) and patients with toxic nodular goitre (15.8, 11.5, 21.2 mg/24 h) exhibited no markedly increased values. Especially, patients with active, untreated ophthalmopathy showed on average a twofold increase (36.7, 28.1, 48.4 mg/24 h) in urinary GAG excretion. In contrast, high values were not found in patients with inactive ophthalmopathy and elevated values decreased under treatment, which correlated with clinical findings. Further, relapses were also accompanied by high GAG excretion. Thus, using a simple laboratory method, quantitative determination of urinary GAG excretion appears to present an effective parameter for the activity of Graves' ophthalmopathy.

Adolescent↗

PubMed1990

Ciamexone in endocrine orbitopathy. A randomized double-blind, placebo-controlled study.

The influence of ciamexone on the activity and course of endocrine orbitopathy was investigated. Fifty-one patients with active orbitopathy classes II-VI were allocated randomly to two groups: over a period of six months, 26 patients received 300 mg/day ciamexone and 25 patients received placebo tablets. In both groups, prednisolone was administered in addition in the first four weeks. Ophthalmological investigations and clinical tests as well as orbit sonography were carried out before as well as one, three and six months after the beginning of therapy. Before and after treatment, computer tomography of the orbit was performed. Symptoms and signs did not show any significant improvement one and six months after therapy. No differences between the two therapy groups were observed. Detailed examination did not reveal any preferential action of the product on individual parameters. Sonography and computer tomography showed no significant alterations of the thickness of the oculomotor muscles. Thus administration of 300 mg ciamexone once a day as compared with placebo did not show any effect on the course and activity of endocrine orbitopathy.

Adjuvants, Immunologic↗