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Biomedical subjects

W Wiesmann

Publications and source records attributed to W Wiesmann.

34 records · Page 2Linked to original sources
PubMed1988

[Experimental thrombolysis of thromboembolisms in the middle cerebral artery circulatory area].

Since the majority of ischaemic cerebral infarcts is caused by thromboemboli, we determined the benefit of fibrinolytic therapy in acute stroke. Thromboemboli were induced in the middle cerebral artery of 21 dogs. Urokinase was started at different time intervals after infarction (1, 3 and 5 hours) at a rate of 1000 IU/kg/min. Angiographically controlled thrombolysis was achieved in all 15 treated cases, whereas in the control group (n = 6) no case of recanalisation was observed. Systemic fibrinolysis occurred in all cases. Postmortem examinations of the brains showed no intracerebral haemorrhages. Our findings indicate that urokinase treatment may be of value in acute ischaemic stroke.

Acute Disease↗
PubMed1988

[Imaging procedures in systemic connective tissue diseases (collagenoses)].

Systemic lupus erythematosus (SLE) and progressive systemic sclerosis (PSS) represent the most frequent manifestations of systemic connective tissue diseases (collagen diseases). Radiological examinations are employed to estimate the extension and degree of the pathological process. In addition, progression of the disease can be verified. In both of the above collagen diseases, specific radiological findings can be observed that permit them to be differentiated from other entities. An algorithm for the adequate radiological work-up of collagen diseases is presented.

Humans↗
PubMed1988

[Computerized tomography and magnetic resonance tomography in soft tissue tumors].

The modern cross-sectional imaging techniques, e.g. CT and MR, have brought about a significant improvement in the diagnosis of soft tissue tumors. CT allows these neoplasms to be detected with relatively high sensitivity and their extension to be assessed. MR has proved to be superior to CT owing to the high soft tissue contrast it provides and its multi-planar imaging capabilities. Gadolinium-DTPA, a paramagnetic agent, can be utilized to good advantage as contrast material in MR; it yields further information as to the malignancy or otherwise of particular tumors. In addition, differentiation of tumor recurrences from other postoperative alterations seems to be feasible.

Humans↗
PubMed1988

[Quality assurance in x-ray diagnosis as specified in DIN 6868].

Regular quality control and safety assurance in diagnostic radiological systems are included in the new radiation protection regulations. The monitoring program for both the equipment and the film processor can enable the user to recognize loss of quality early. Variables in the film processing unit can be differentiated from faults in the X-ray equipment more easily, including its use. The cost and time spent in setting up a safety assurance program are justified by the increase in quality.

Germany, West↗
PubMed1987

[Thrombolysis of cerebral thromboembolism by urokinase in an animal model].

The majority of ischemic cerebral insults are caused by thromboembolism. In animal experiments we have investigated the possibility of reperfusing ischemically damaged brain tissue by thrombolysis of cerebral emboli. 1, 3 and 5 hours after cerebral infarction due to thromboembolism, thrombolytic treatment with urokinase (1000 IU/kg/min) was started. Thrombolysis, monitored by angiography, was successful in all cases (n = 15). In all cases the fall in fibrinogen, alpha 2-antiplasmin and plasminogen reflected systemic fibrinolytic effects. Anatomo-pathologic investigation of the brains revealed no intracerebral bleeding complications. The results of the study suggest a favourable effect of urokinase on acute ischemic cerebral infarction.

Acute Disease↗
PubMed1987

[Clinical pictures of pulmonary aspergillosis].

Pulmonary infection with Aspergillus can present a variety of clinical manifestations. Essentially, allergic bronchopulmonary aspergillosis, aspergilloma, and invasive aspergillosis are the three main forms. The coexistence of more than one of these entities is not unusual. Predisposing factors for such mycotic infections include previous lung-structure damage, immunodeficiency, and disturbances in the equilibrium of the resident flora of the respiratory tract. The radiological changes in pulmonary aspergillosis are described in association with clinical presentations and laboratory findings and are demonstrated by actual examples.

Aspergillosis↗
PubMed1987

[Intrahepatic collateral veins in obliteration of the inferior vena cava].

Occlusion of the inferior vena cava (IVC) can be either congenital or acquired. Tumors at the porta hepatis are the most common cause of acquired occlusion. Various pathways of venous collateralization are described. The development of a transhepatic venous shunt depends on the isolated inflow of the liver veins into the IVC at different levels, with flow reversal in the most inferior hepatic vein. The case of a 46-year-old female patient with an intrahepatic venous shunt is presented. Ultrasound, computed tomography, magnetic resonance imaging and angiography were performed. Their relative diagnostic values are discussed.

Collateral Circulation↗
PubMed1986

[Acute focal bacterial nephritis].

Acute focal bacterial nephritis is a very rare type of infective nephritis. It is characterised by groups of abscesses of 1 to 5 mm. situated in the renal cortex with pus tracking to the papillae. Urography is normal or suggests a non-specific enlargement. On sonography, non-homogeneous foci with reduced echogenicity are observed. Unenhanced CT shows indefinite lesions of reduced density, which do not enhance as much as the surrounding parenchyma after contrast injection. On angiography these areas appear as hypovascular lesions. The disease must be differentiated from a malignant renal tumour and from an acute renal abscess. The clinical findings and the results of sonographic and radiological observations on five patients with acute focal bacterial nephritis are described.

Acute Disease↗
PubMed1986

[Radiological diagnosis of aggressive fibromatosis].

Aggressive fibromatosis (desmoid, desmoid tumour) resembles, in its infiltrating and destructive growth, a fibrosarcoma, but does not metastasize. Because of its high recurrence rate, the tumour remains a surgical problem. Various imaging methods were evaluated retrospectively in 23 patients with histologically confirmed aggressive fibromatosis. Conventional radiological procedures are poor at demonstrating the extent and type of tumour. Modern tomographic methods are more able to determine the size of the lesion and a combination of angiography and CT can frequently provide a definite diagnosis.

Adolescent↗
PubMed1986

[Radiological diagnosis of adrenal gland diseases].

Among all the radiological examination techniques, CT is today, besides scintigraphy, the method of choice as far as the detection of functional adrenal lesions is concerned. In primary aldosteronism, CT classification of the syndrome is based on the detection of an adenoma which can be reliably detected in adenoma sizes up to 8-10 mm. Thus, 70 to 80% of Conn's syndromes can be classified. In adrenal Cushing's syndrome, the distinction between adenoma and carcinoma of the adrenal gland is up to CT and can usually be easily made due to the characteristic morphology of each type of lesion. In case of a typical adrenal or juxtaadrenal tumor location, detection of a pheochromocytoma is likewise easy. In ectopic and multiple pheochromocytomas or such as occur as part of a MEN-syndrome, the situation is quite different. If lesions of the adrenal gland are found by accident in examinations otherwise indicated, the question arises whether the process is malignant or benign. In this respect, all the traditional imaging methods, including CT, involve a considerable factor of uncertainty, especially if a malignant tumor is anamnestically known and the question of metastases arises. According to recent information, MR-imaging seems to be advantageous concerning this difficult differential diagnosis.

Adrenal Gland Diseases↗
PubMed1984

[Sipple syndrome as a differential diagnosis in recurrent laryngeal nerve].

Two cases of Sipple's syndrome with the typical signs of medullary carcinoma of the thyroid, pheochromecytoma and parathyroid adenoma are presented. Cushing's disease and marfanoid habitus were demonstrated. They are classified as multiple endocrine adenopathy type 2A and 2B according to the modern nomenclature.

Adult↗
PubMed1978

Cholinergic agents inhibit sodium transport across the isolated toad bladder.

Acetylcholine and carbamylcholine (carbachol) inhibited sodium transport across the toad bladder. This effect was blocked by atropine. Carbachol increased the uptake of 45Ca by isolated toad bladder epithelial cells. This increased 45Ca uptake was blocked by atropine, pentobarbital, or lanthanum chloride. The inhibitory effect of cholinergic agents on sodium transport was dependent on external calcium concentration and was abolished by decreasing external calcium from 2 to 0.2 mM or by agents (pentobarbital, lanthanum chloride) which prevent the movement of calcium into cells. Carbachol increased modestly, but significantly, the levels of cyclic GMP in isolated toad bladder epithelial cells. This effect was blocked by atropine. Whether the decrease in sodium transport produced by cholinergic agents is the result of increased intracytoplasmic calcium levels, increased cyclic GMP levels, or a combination of both remains to be established.

Acetylcholine↗
PubMed1977

Effects of ionophore A23187 on base-line and vasopressin-stimulated sodium transport in the toad bladder.

The cation specific ionophore A23187 (Io) is a useful tool for studying the role of intracellular Ca++ (Ca++)i in physiologic processes. The present studies explore the role of (Ca++)i on Na transport in the toad bladder. Scraped bladder cells exposed to 1 muM Io for 60 min took up 100% more 45Ca than control cells. Io, 1 muM, added to the serosal side of bladders incubated in standard Ringers containing 2.5 mM Ca++ inhibited short circuit current (SCC) values by a mean of 30% at 60 min and 50% at 90 min. Io did not inhibit SCC significantly in bladders incubated in Ringers containing 0.2 mM Ca++. These data indicate that the effects of Io on SCC depend on the levels of external Ca++ and suggest that entry of Ca++ into cells mediates the inhibition of base-line SCC. PReincubation of the bladders with either lanthanum chloride or pentobarbital prevented the increased 45Ca uptake produced by ionophore as well as theinhibition of SCC caused by the antibiotic. Vasopressin, antidiuretic hormone (ADH). 10 MU/ml, increased peak SCC by 247% in bladders preincubated for 1 h in Ringers with 2.5 mM Ca++ and 1 muM Io and by 318% in control bladders (P less than 0.01). Bladders exposed to 1 muM Io in Ringers with 0.2 mM Ca++ had an increase in SCC after ADH comparable to that observed in controls. Since the effects of ADH on SCC are mediated by cyclic AMP, we tested the effects of Io on cAMP production by scraped toad bladder cells. ADH increased cAMP from 8 to 30 pmol/mg protein in controls but it did not increase cAMP over base-line values in the presence of Io when the Ringers contained 2.5 mM Ca++. Io did not inhibit cAMP production in response to ADH when the Ca++ in the Ringers was 0.2 mM. The results indicate that Io inhibits baseline and ADH stimulated SCC by increasing (Ca++)i or Ca++ bound to the cell membrane. It is suggested that: ()( (Ca++)i or membrane-bound Ca++ plays a key role in base-line and ADH stimulated Na transport in the toad bladder; (2) inhibition of ADH stimulated SCC may be due inpart to decreased cAMP generation in response to ADH when (Ca++)i or membrane-bound Ca++ levels are increased.

Animals↗