Search PubMed⌕ Search

Biomedical subjects

T Weiss

Publications and source records attributed to T Weiss.

At least 127 records · Page 7Linked to original sources
PubMed1988

Identification of the receptor for erythropoietin on human and murine erythroleukemia cells and modulation by phorbol ester and dimethyl sulfoxide.

Erythropoietin, a glycoprotein that regulates erythropoiesis, initiates its biological effects by binding to a cell-surface receptor. Little is known about the structure of the erythropoietin receptor and the events that follow binding of erythropoietin to its receptor, in part because of the difficulty of obtaining sufficient quantities of cells that express the erythropoietin receptor. We used both iodinated and metabolically labeled erythropoietin to characterize the receptor on a variety of erythroleukemia cell lines not previously tested, and we have identified both human and murine cell lines that display large numbers of erythropoietin receptors. Both erythropoietin-responsive and -nonresponsive cell lines exhibit a single class of binding sites. The human erythroleukemia cell line OCIM1 exhibits approximately 3000 erythropoietin receptors per cell with a Kd of 280 pM. The erythropoietin-responsive Rauscher red 5-1.5 murine erythroleukemia cell line displays approximately 1700 receptors per cell with a Kd of 440 pM. The GM979 murine erythroleukemia cell line has approximately 1600 receptors per cell with a Kd of 660 pM. Induction of the erythroid phenotype by dimethyl sulfoxide or its suppression by phorbol 12-myristate 13-acetate was accompanied by an increase or decrease, respectively, in erythropoietin receptor number. Affinity crosslinking of labeled erythropoietin to the receptor identified two proteins corresponding to estimated molecular masses of 95 and 105 kDa. The OCIM1, Rauscher, and GM979 erythroleukemia cell lines provide a useful model for the study of postreceptor signaling events, as well as a convenient source for purification of the erythropoietin receptor.

Animals↗
PubMed1988

[Modification of mucociliary clearance by a combination of theophylline with ambroxol and of ambroxol in monotherapy].

Influence on Mucociliary Clearance by a Theophylline-Ambroxol Combination and by Ambroxol in Monotherapy. In a controlled randomised double-blind study the influence of theophylline + ambroxol (TA) and ambroxol (A) on lung function and mucociliary clearance was investigated. 19 patients with chronic obstructive lung disease were treated after a 5-day wash-out period for 5 days with TA (700 mg theophylline, 60 mg ambroxol/d) or A (60 mg ambroxol/d), respectively. Measurements were done on the 5th and 10th day. Under the treatment with TA a marked improvement of lung function was observed. The mucociliary clearance improved under treatment with TA and A, with TA being significantly better compared with treatment group A.

Adult↗
PubMed1988

An apparatus for a complimentary treatment of spasmodic torticollis.

We have developed an apparatus for treating spasmodic torticollis that can be used at home both during intensive therapy and follow-up. The refractoriness of spasmodic torticollis requires patients to practice biofeedback training partly on a home basis. However, it is usually difficult for spasmodic torticollis patients to provide and handle electromyographic (EMG) biofeedback training instruments. The present apparatus has 2 parts: first, a harness with a light source which is fixed on both shoulders; second, a photoreceptor, operant system for rewarding effect, and a digital recorder. The light is adjusted to strike the photoreceptor on the forehead when headposition is normal. Subjects are asked to keep the operant system--e.g. a radio--activated. They are trained in various postures as sitting, standing and walking. This apparatus provides a chance of home training to augment and maintain the effect during therapeutic sessions and the follow-up period.

Biofeedback, Psychology↗
PubMed1988

An amperometric glucose sensor with combined enzyme layers.

An amperometric needle-type glucose sensor consisting of a silver tube as the cathode and a platinum wire as the anode was developed. The sensor was provided with two enzyme layers (glucose-oxidase and catalase) separated by a polyurethane membrane. The catalase caused an accelerated decomposition of H2O2 generated during the enzymatic oxidation of glucose. In this way the lifetime of the sensor and the oxygen dependence of the analytical signal could be improved.

Biosensing Techniques↗
PubMed1988

A potentially implantable enzyme electrode for amperometric measurement of glucose.

A membrane limited amperometric enzyme electrode suitable for glucose measurement in biological fluids was developed. The sensor consists of a central platinum wire (0.3 mm) surrounded by a stainless steel tubing (0.8-1.0 mm outer diameter; 2-4 cm length). By successive dipcoating procedures, layers from cellulose acetate, glucose oxidase (crosslinked with glutaraldehyde) and polyurethane are placed on its surface. The platinum is polarized at +700 mV against steel. In vitro results: Electrodes are stable for at least 6 days. They exhibit a linear range extending to 500 mg/dl glucose. Response times are less than 100 sec. The sensors are not dependent on stirring and are relatively insensitive to changes of pH. Dependency of glucose measurement upon dissolved oxygen is negligible at oxygen concentrations above 0.5 mg/l. In vivo results: Preliminary studies in sheep using subcutaneously implanted needles indicate that short term glucose monitoring is feasible.

Animals↗
PubMed1988

[Magnetic resonance tomography (MRT) in bronchial cancer].

Comparative studies were made of 47 patients suffering from histologically and cytologically confirmed bronchial carcinoma, using CT and MRT respectively. CT examinations were performed before and after intravenous administration of contrast medium, whereas the MR examinations were conducted via EEG-triggered T1 and T2 marked SE sequences in the axial and coronary planes. Both methods were assessed in respect of tumour visualisation and documentation of tumour spread. Staging of tumour and lymph nodes yielded largely concurring results for CT and MRT. Exceptions were seen in 7 of 10 patients with malignant involvement of the pericardium and in 3 of 27 patients with lymph node metastases located mediastinally and subcarinally where only MRT showed a positive involvement of the pericardium or lymph nodes (with possible consequences for the staging of the tumour or lymph nodes). Decisive advantages of MRT compared with CT were seen in the identification of infiltration of the aortic-wall, in the differentiation of the poststenotic syndrome, in the visualisation of the thoracic wall infiltration and functional information on blood flow rate in upper venolus obstruction caused by a carcinoma.

Carcinoma, Bronchogenic↗
PubMed1987

Multifocal static creamy choroidal infiltrates. An early sign of lymphoid neoplasia.

Three patients, each more than 60 years of age at initial presentation, had early stage lymphoid infiltrates (formerly called reactive lymphoid hyperplasia) of the choroid and contiguous extraocular tissues. There were multifocal, confluent, and nonconfluent creamy patches in the choroid. These lesions changed very little over periods of observation ranging from 1 to 4 years and failed to produce ophthalmoscopically visible disturbances of the retinal pigment epithelium (RPE). Fluorescein angiography demonstrated dye collection within the lesions without leakage into the subretinal or subpigment epithelial spaces. Both ultrasonography and computed tomography (CT) showed thickening of the choroid with either anterior or posterior episcleral extensions of lymphoid tissue. Pathologic evaluation of biopsy specimens of extraocular portions of the lesions showed low-grade tumors that were diffuse infiltrates of mature lymphocytes, which exhibited lymphoplasmacytoid features, Dutcher bodies, or small residual germinal centers (so-called borderline lesions). Two patients had uniocular localized disease, whereas the third had bilateral ocular lesions, hypogammaglobulinemia, and another extranodal chest wall lymphoid tumor. Therapy for the localized ocular condition consisted either of oral administration of corticosteroids or low doses of radiotherapy.

Aged↗
PubMed1987

[Rapid nuclear magnetic resonance tomography. Initial results of studies using the new gradient echo sequence].

In 60 patients with intracerebral lesions, examined by MRI, a new gradient-echo sequence was employed. This imaging technique uses excitation pulse angles smaller than 90 degrees and echoes are produced by an inversion of the read gradient. Since no 180 degrees pulse between successive excitations is necessary, very short repetition times can be used. Depending on matrix-size and signal averaging, MR imaging time can be reduced to approximately 5 to 40 seconds for single slice scan. For comparison, conventional T1- and T2-weighted spin-echo images were performed. Diagnostic results of the T1-weighted fast gradient-echo images corresponded with T1-weighted spin-echo images in 30% of cases. Diagnostic information was lower in 40% of cases. In the remainder of cases (30%) lesions were not detected with the gradient-echo technique. This especially applied to multiple sclerosis, infarctions and low-grade gliomas. Due to image artefacts and low contrast, visualization of small pathologic lesions was limited. Significant improvement of tumor visualization on gradient-echo scans was observed after injection of Gd-DTPA (0.1 mmol/kg).

Brain Diseases↗
PubMed1987

[Magnetic resonance tomography of intrathoracic tumors].

65 patients suspected of having intrathoracic masses were studied using magnetic resonance imaging (MRI) and computed tomography (CT). The intensity difference between mass and adjacent normal tissue or mediastinal fat was greater on MRI than on CT images. MRI was superior to CT in differentiating bronchogenic carcinomatous tumours from postobstructive pneumonia and/or lobar collapse. MRI images most clearly depicted obstructed mediastinal vessels and were also able to indicate intravenous flow reductions. The latter could be demonstrated by an increase of signal intensity within venous structures proximal to the obstruction. In patients with lung cancer no significant differences were found between the two imaging methods for the evaluation of tumour extent or node involvement.

Bronchogenic Cyst↗
PubMed1987

[Effect of a secretolytic and a combination of pinene, limonene and cineole on mucociliary clearance in patients with chronic obstructive pulmonary disease].

Effect of a Secretolytic and a Combination of Pinene, Limonene and Cineole on Mucociliary Clearance in Patients with Chronic Pulmonary Obstruction. Studies demonstrating the elimination of radioactive particles during a 7-day course of therapy with 3 x 30 mg ambroxol or 4 x 1 capsule. Gelomyrtol forte (1 capsule = 0.3 g Myrtol, standardised to at least 20 mg of alpha-pinene, 75 mg of limonene and 75 mg of cineole (eucalyptol) yield improved mucociliary clearance in both groups. No change of lung function was observed.

Adult↗
PubMed1987

[Nuclear magnetic resonance tomography of superior vena cava obstruction].

The potential of magnetic resonance tomography (MRT) to demonstrate the mediastinal veins was evaluated retrospectively in 6 patients with superior vena cava obstruction. In each instance, MRT provided detailed information about the extent of venous obstruction and the precise site of the causative oncological pathology. Transaxial images most clearly and unequivocally depicted obstructed superior vena cava. MRT was also able to indicate some secondary effects of superior vena cava obstruction such as slow intravenous flow. The latter could be demonstrated by a significant increase of signal intensity within venous structures proximal to the obstruction. Peripheral venous collaterals in the chest wall were better seen with contrast enhanced computed tomography scans.

Collateral Circulation↗
PubMed1986

[Course of conservatively treated acute lumbar root compression syndrome. A computer tomography controlled study].

Of 129 patients with an acute lumbar root compression syndrome due to disc herniation 21, who were symptom-free, were examined by computed tomography (CT) on average 276 days after a three-step regimen of conservative treatment. In no instance had there been a deterioration of the original findings. In 14 patients the CT picture continued to demonstrate disc herniation, although the patients were without symptoms. In two patients a moderate, in five a marked regression of herniation was demonstrated by CT. Clinical improvement without change in the CT picture points to the compression syndrome not being explainable solely in mechanical terms. As a matter of fact, a possible cause may be a disturbance of radicular blood supply resulting in oedematous root swelling which is usually masked in the CT by prolapsed disc tissue. There is as yet no easy explanation for regression in case of prolapsed, perhaps even sequestered, disc tissue. It is possible that there have been reparative processes, such as have been described histopathologically in form of ingrown vessels. More plausibly would be a separation of the herniated and/or sequestered disc tissue in form of an asymptomatic sliding into the terminal caudal region.

Adult↗
PubMed1986

CT of the postoperative lumbar spine: the value of intravenous contrast.

Sixty-five patients with recurrent radicular complaints after operation for lumbar disc herniation underwent CT examination before and after intravenous contrast application (volume: 1.5-2.0 ml/kg body weight; flow rate: 0.35 ml/s). Postsurgical hypertrophic scar tissue showed definite contrast enhancement, whereas disc herniation remained unenhanced. Intravenous contrast application is recommended in patients previously operated upon for disc herniation.

Cicatrix↗