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Biomedical subjects

J Beyer

Publications and source records attributed to J Beyer.

At least 325 records · Page 18Linked to original sources
PubMed1989

[Long-term study of endocrine ophthalmopathy and retrospective assessment of therapeutic measures].

The follow-up of Graves' ophthalmopathy was analysed regarding to clinical and chemical data on the one hand and to dependence on different therapeutic alternatives on the other. 297 patients (44 +/- 14 years, 249 female, 48 men) were observed with inclusion of data from the history and clinical data as well (computer tomography and orbital sonography). At the onset of therapy 253 patients were hyperthyroid, 36 euthyroid and eight showed hypothyroidism. The staging was: I 13, II 54, III 113, IV 95, V five, VI eight patients. The HLA-typing in 89 patients showed the following results: B8 in 32%, DR3 in 42%, B8 as well as DR3 in 24% of the patients. In about 50% of the cases there were raised microsomal and in about 18% there were raised thyroglobuline antibodies. 63% of the patients received immunosuppressive medication: corticosteroids in 100% (more than one time in 43%), cyclosporine A in 11%, ciamexone in 10%, other non-steroid immunosuppressants in 5% of the cases. The retrobulbar irradiation was performed in 9%, and total thyroidectomy in 7%. During therapy the inflammatory process was clearly ameliorated, however exophthalmos and diplopia were more resistant to treatment. In the group of patients with combined cyclosporine and prednisone therapy and in the group of patients with total thyroidectomy and partly retrobulbar radiotherapy, significant differences were observed regarding to visual acuity and Hertel values. None of the therapies applied constitutes an optimal treatment with the regard to the long-term course. Under therapy an improvement can be reached, but no complete healing.

Adolescent↗
PubMed1989

[Thyroxine vs iodine and thyroxine. Comparison of the TSH suppression test].

In a crossover study 20 subjects (12 with non-toxic goiter) were given 150 micrograms levo-thyroxine (LT4) or a combination of 100 micrograms LT4 and 100 micrograms iodide daily for 8 weeks. Group I took 150 micrograms LT4 and group II the combination. After 4 weeks the two groups switched medications. A clinical examination, an intravenous TRH test and thyroid sonography were performed before the start of the study and 4 and 8 weeks thereafter. 150 micrograms LT4 daily resulted in significantly higher TSH suppression than the combination. A decrease in thyroid volume from 45 ml (mean range 24-85) to 26 ml (17-70 ml) was registered after as little as 4 weeks' therapy in 12 of 20 subjects with goiter.

Adult↗
PubMed1989

HIV-2 antibody testing of blood donors with doubtful immunoblot results for HIV-1.

Antibodies against human immunodeficiency virus type-1 (HIV-1) in samples from blood donors are commonly detected by various enzyme-linked immunosorbent assays (ELISA) and by confirmatory tests, e.g., "Western blot" or immunofluorescence tests. Immunoblot reactivity, which is directed only towards the HIV-1 core proteins p 18, p 24 and p 55, may represent false-positive reactions. Out of 125,000 blood donations, 140 were repeatably HIV-1 antibody reactive by ELISA; of these, 20 were doubtful positive sera with isolated p 18 and/or p 24 bands in the HIV-1 confirmatory assay. Antibodies to HIV-2 are known to cross-react with these HIV-1 core proteins. We therefore assayed the 20 sera by immunofluorescence and immunoblotting for the presence of antibodies to HIV-2. None of these doubtful HIV-1 antibody positive blood donor sera was found to have antibodies to HIV-2.

Blood Donors↗
PubMed1989

Relationship between pituitary ACTH content and hypothalamic catecholamines in the rat.

Hypothalamic concentrations of epinephrine and norepinephrine were determined in rats following 6-hydroxydopamine lesions of the locus coeruleus and subcoeruleus system and following sham-operation. These concentrations were correlated with pituitary ACTH content. While the lesion procedure did not have a major effect on hypothalamic monoamine levels, we were able to demonstrate a strong negative correlation between hypothalamic epinephrine and pituitary ACTH content independent of the experimental condition. Only a weak negative correlation was observed for hypothalamic norepinephrine and pituitary ACTH. Our recent and previous data suggest a tonic and phasic inhibition of ACTH release by hypothalamic monoamines.

Adrenocorticotropic Hormone↗
PubMed1989

Ciclosporin and thyroid-stimulating immunoglobulins in endocrine orbitopathy.

The study investigated whether ciclosporin (C) affected the thyroid-stimulating immunoglobulins (TSI) in serum of patients with endocrine orbitopathy (EO). The effect of C was compared with that of prednisone (P). Fifteen patients with EO classes III-V received C (n = 7) or P (n = 8). In addition to the immunosuppressants, five patients with Graves' disease in each group received methimazole (MMI). The stimulation of the cAMP levels in the medium of thyrocyte cultures was determined as a parameter of TSI. The TSI levels were markedly lowered in both groups during and after therapy. C group: before therapy 6.2 pmol/ml +/- 1.63 (100%, mean +/- SEM), during treatment 4.6 pmol/ml +/- 2.28 (74%), after treatment 4.1 pmol/ml +/- 1.33 (66%). P group: before treatment 9.1 pmol/ml +/- 3.42 (100%), during treatment 5.9 pmol/ml +/- 2.90 (65%), after treatment 3.7 pmol/ml +/- 1.20 (41%). There is neither a significant difference between the two groups nor between the patients who received the combined therapy (MMI + immunosuppressants) or only received immunosuppressants (P more than 0.05). The mean cAMP value of the healthy reference group (n = 19) is 0.4 pmol/ml +/- 0.03. There is a significant difference between this value and the cAMP values of the patients both before and after therapy (P less than 0.01). Thus, both C and P markedly lower the TSI titers of patients with EO.

Adult↗
PubMed1989

Direct tubular effect on calcium retention by hydrochlorothiazide.

Previous studies with hydrochlorothiazide revealed a calcium retaining effect of this substance. The mechanism by what this is done is still matter of controverse discussion. Effects of hydrochlorothiazide on vitamin D metabolism have been reported as well as those on parathyroid function. To further clarify the calcium retaining potency of hydrochlorothiazide (HCTZ) we treated 10 healthy young volunteers for four weeks with 2 x 50 mg HCTZ. In all volunteers we observed a marked decrease in urinary calcium excretion as well as in calcium clearance. Furthermore, we found a slight rise in ionized serum calcium (6.7%) and in intact PTH, as well as a 36% drop in 1,25-(OH)2-D3-levels. These effects were reversible after discontinuation of the treatment. No change was observed in urinary cAMP, phosphate excretion, serum anorganic phosphate levels, serum calcitonin and magnesium levels. Data presented here suggest that treatment with HCTZ causes a persistent reduction in calcium excretion through direct tubular effects, inhibits hydroxylation of vitamin D, and does not affect parathyroid function.

Adult↗
PubMed1989

Eye muscle antibodies in endocrine exophthalmos. Clinical and serological observations.

Serum samples were obtained from 65 patients with endocrine exophthalmos class I-V. In 33/65 patients who were treated either with prednisone or with ciclosporin, blood was sampled before, during and after therapy. Antibodies against eye muscle were determined during the course of immunosuppressive therapy in order to have an objective parameter of the therapeutic effect. To ascertain the specificity of the reaction both eye and abdominal muscles were used as antigens in an ELISA system. Both IgG and IgM antibodies were detected. In 45/65 patients (71%) eye muscle antibodies were positive before starting therapy. Antibodies were mostly detected in patients with active disease. Patients with exophthalmos of recent onset always had IgM antibodies whereas patients with chronic exophthalmos were mostly IgG positive. Patients with relapse showed mostly IgG but also IgG and IgM positivity in 2 cases. In 58% of cases only IgG antibodies were found whereas in 34% both IgG and IgM were detected and in 8% only IgM antibodies. There was no association between antibodies directed against eye muscle and thyroid microsomal and thyroglobulin antibodies or with the state of thyroid function. Furthermore there was no correlation between exophthalmos classes and eye muscle antibody binding activity. The antibody level declined during therapy with prednisone or with ciclosporin but rose again 8-12 weeks after stopping the drug in patients with progressive disease.

Adolescent↗
PubMed1989

Modification of leucine transport across bovine pigment epithelium by metabolic stress.

The transport of leucine in the apical-to-basal (retina to choroid) direction across the isolated bovine retinal pigment epithelium is mediated predominantly by the L amino transport system at low carrier (10 microns) concentrations. There is no evidence of an active or facilitated transport system operating in the opposite direction. The identification of the L system is based on the lack of sodium dependence, specific inhibition of leucine transport by 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH), and the demonstration of trans-stimulation. Lysine, glutamate, and 2-methylaminoisobutyric acid (MeAIB) did not provide any competitive inhibition. Ouabain and iodoacetate were also ineffective in modifying leucine transport. The transport mediated by the L system was markedly temperature sensitive, whereas no temperature dependence was apparent in the transport of leucine in the basal-to-apical direction (choroid to retina). When treated with dinitrophenol (DNP), the transport of leucine in the apical-to-basal direction was greatly enhanced, but no effect was observed on the leucine movement in the opposite direction. Azide and rotenone had an effect similar to DNP, as did reducing the partial pressure of O2 to less than 40 Torr. The enhancement of transport appeared to be mediated by the activation of an ancillary system, since it was susceptible to different classes of metabolic and competitive inhibitors as well as the observed ionic dependency. After DNP treatment, the transport of leucine was inhibited by lysine and BCH, revealed a sodium dependence, and could be inhibited by iodoacetate. The characteristics of the enhanced transport appear to be similar to those of the recently described G system(s) of amino acid transport.

Amino Acids↗
PubMed1989

Effects of l-tryptophan and various diets on behavioral functions in essential hypertensives.

The effects of tryptophan in combination with two different diets (high-carbohydrate and high-protein diet) on behavioral parameters such as mood, sleep and performance were chronically studied in a group of 34 hypertensive patients undergoing a trial of testing the antihypertensive properties of l-tryptophan. While no major changes in mood were observed, there was a tendency for sleep latency to decrease and sleep duration to increase following tryptophan intake in the intragroup analysis. The administration of tryptophan caused a significant improvement on performance in a concentration task. No significant dietary effects were observed either in combination with tryptophan or in the placebo group. These data again demonstrate behavioral relevance of the precursor amino acid l-tryptophan and suggest a long-term improvement in partial aspects of performance behavior.

Adult↗
PubMed1989

Dexamethasone does not suppress the respiratory analeptic effect of corticotropin-releasing hormone.

Human CRH (hCRH), which acts as a major neuroregulator within the hypothalamic-pituitary-adrenal axis, is also a respiratory stimulant. The broad distribution of CRH receptors in brain areas involved in respiratory regulation is consistent with this finding. This study was designed to investigate whether ACTH or cortisol mediates the respiratory stimulation effect of CRH. Bolus injection of 100 micrograms hCRH induced significant respiratory stimulation in all 10 normal subjects studied. hCRH given after the administration of 2 mg dexamethasone, which greatly reduced plasma cortisol levels, had the same respiratory effect on respiration. Thus, increase in plasma ACTH and cortisol concentrations are probably not involved in the respiratory analeptic effect of CRH.

Adult↗
PubMed1989

Coumamidines, new broad spectrum antibiotics of the cinodine type. III. Microbiologic activity of coumamidine gamma 1.

The coumamidines are novel antibiotics with activity against a wide spectrum of aerobic Gram-positive and Gram-negative bacteria. All microbiological studies were performed on coumamidine gamma 1. The MIC90s (micrograms/ml) of coumamidine are as follows: Staphylococcus aureus 1.0, Streptococcus pyogenes 8, Enterobacteriaceae 2.0, Pseudomonas aeruginosa 8, Campylobacter jejuni and Campylobacter coli 1, Legionella pneumophila 8, Haemophilus influenzae 0.5, Neisseria gonorrhoeae 0.5. Coumamidine had MICs ranging from 8 to greater 0.5, Neisseria gonorrhoeae 0.5. Coumamidine had MICs ranging from 8 to greater than 64 for most anaerobes, except some Peptostreptococcus strains. The aminoglycoside super-sensitive strain, P. aeruginosa BMH 10, was also super-sensitive to coumamidine (MIC 0.2 micrograms/ml). Coumamidine was rapidly bactericidal for S. aureus. The viable bacterial count in logarithmic phase cultures was reduced to less than 10 cfu within 2 hours after exposure to 4 times the MIC (3.12 micrograms/ml) of coumamidine. The frequency of resistance development was less than 1 X 10(-9) for Escherichia coli and S. aureus when selected at 4 and 8 times the MIC. The Cmax in mouse serum after a single subcutaneous dose of 25 mg/kg of coumamidine was 4.5 micrograms/ml and t1/2 was 1 hour. Coumamidine is stable in serum. In mouse protection tests against S. aureus NCTC 10649 the ED50 was less than 0.6 mg/kg/day when it was administered subcutaneously at 1 and 5 hours after infection. Coumamidine was not absorbed after oral administration. The antibacterial spectrum, bactericidal activity, stability in serum and low frequency of resistance make this an interesting new class of antibiotics.

Aminoglycosides↗
PubMed1988

Immunosuppressant therapy of thyroid eye disease.

Thyroid eye disease is attributed to an autoimmune process where both cellular and humoral immunity play a role. In this report, after a short introduction dealing with immunopathogenesis of the disease, immunosuppressant therapy is discussed. Treatment with glucocorticoids (as the standard substance), nonsteroid immunosuppressants (azathioprine, cyclophosphamide, lately cyclosporin) and with the immunomodulatory substance ciamexone is reviewed. Retroorbital irradiation as a "local" immunosuppressive method and plasmapheresis are also discussed. While systemic glucocorticoids and to a lesser extent orbital radiotherapy are routinely administered for severe Graves' ophthalmopathy, nonsteroid immunosuppressants and plasmapheresis are not yet part of the established treatment of thyroid eye disease. Their use should currently remain confined to controlled studies.

Graves Disease↗
PubMed1988

Evaluation of the clonidine-suppression test in the diagnosis of pheochromocytoma.

In this study we examined the preoperative value of the clonidine-suppression test in 15 patients with surgically proved pheochromocytomas. The result of the clonidine-suppression test was pathological (epinephrine plus norepinephrine above 500 ng/l 3 h after clonidine) in 10 of 15 patients (66%). These patients had relatively large tumors and higher basal norepinephrine plasma levels. Out of the 5 cases without a pathological clonidine test 4 had normal basal plasma catecholamine levels with the result that the clonidine test could not be properly applied and 1 case produced a false negative result. These 5 cases generally had smaller tumors and lower plasma catecholamine levels. Two of these cases had basally raised epinephrine values. The other three cases had either a paradoxical increase or a suspiciously low fall (less than 25%) in norepinephrine within the normal range. We conclude that the clonidine-suppression test is only reliable for the diagnosis of relatively large pheochromocytomas.

Adrenal Gland Neoplasms↗