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Biomedical subjects

G Kirsch

Publications and source records attributed to G Kirsch.

At least 19 recordsLinked to original sources
PubMed1992

Synthesis and biological activities of 8(14)a-homocalcitriol.

8(14)a-Homocalcitriol was synthesized and tested for its biologic activities. It exhibited a vitamin D agonist activity profile. The compound was bound to the pig intestinal receptor with an affinity slightly less than calcitriol, showed the same potency in inducing HL 60 cell differentiation and inhibition of keratinocyte proliferation as calcitriol, and was found to be approximately 10-fold less potent in inducing hypercalcemia and hypercalciuria after a single injection in normal rats.

Animals↗
PubMed1992

Basics and recommendations for brain SPECT. Task Group "Neurology" of the European Association of Nuclear Medicine.

In this article guidelines for single-photon emission computerized tomography (SPECT) of the brain are presented by the Task Group "Neurology" of the European Association of Nuclear Medicine (EANM). Under separate headings are discussed: the pathophysiologic principles of various brain diseases, pharmacokinetics and pharmacodynamics of various radiopharmaceuticals, physical principles of SPECT imaging, computerized data processing, clinical protocols and the evaluation of SPECT results.

Brain↗
PubMed1991

Control of K+ channels by G proteins.

Heterotrimeric G3 proteins are though to couple receptors to ionic channels via cytoplasmic mediators such as cGMP in the case of retinal rods, cAMP in the case of olfactory cells, and the cAMP cascade in the case of cardiac myocytes. G protein-mediated second messenger effects on K+ channels are dealt with elsewhere in this series. Recently, membrane-delimited pathways have been uncovered and an hypothesis proposed in which the alpha subunits of G proteins directly couple receptors to ionic channels, particularly K+ channels. While direct coupling has not been proven, the membrane-delimited nature has been established for specific G proteins and their specific K+ channel effectors.

Animals↗
PubMed1979

[Peripheral blood flow in patients with necrobiosis lipoidica (diabeticorum)].

For the judgment of the peripheral blood supply 16 insulin-dependent diabetics with necrobiosis lipoidica at the lower extremities were compared with 15 insulin-dependent diabetics without necrobiosis lipoidica. The vascular changes in form of retinopathy, nephropathy, neuropathy, hypertension, the results of the radiologically provable vascular changes, oscillograms and impedance plethysmograms as well as the results of the muscle and skin clearance and angioscintigraphy were evaluated. The at last mentioned methods give an insight into the microangiopathy. The apparantly contradicting findings of the muscle clearance (smaller blood supply) and of the skin clearance (increased blood flow) find their explanation by the angioscintigraphically proved different regional parameters of blood flow in the necrobiotic regions. The angiopathic findings are characterized by the enrichment of activity in the marginal seam as a sign of hyperemia and decreased accumulation in the centre as an expression of necrobiosis. The changes of the connective tissue and their causes of development are discussed. Angiopathic and traumatic influences conditioned by metabolism, apart from local peculiarities are taken into consideration.

Adolescent↗
PubMed1979

[Extra-intracranial arterial bypass for cerebral trauma].

A report is given on a young patient with a cerebral haemorrhage due to an occlusion of the A. carotis interna and the median main stem in which a regression of the one-sided symptoms could be achieved by a microneurosurgical establishment of an extra-intracranial anastomosis. The improvement of the cerebral perfusion could be objectivated angiographically and scintigraphically. The case shows that the prognosis of the cerebro-vascular lesion, especially in young and middle-aged patients, can be improved by surgical formation of collaterals. This gives hope for a further development of this method of treatment.

Adult↗
PubMed1979

[Radionuclide angiography in the functional assessment of surgical extra- and intracranial vascular anastomoses].

Extra-intercranial arterial vascular anastomosing is a surgical form of treatment in selected patients with ischemic cerebral diseases. For the demarkation of the indication for an operation and for the objectification of the functional results cerebrovascular radionuclide angiography was carried out in seven patients with cerebrovascular insufficiency before and after the bypass operation. The non-invasive method only requires an intravenous bolar radionuclide application. It permits a well reproducible appraisal of the regional cerebral blood flow. The best functional results of the shunt operation were observed in the radionuclide angiogram of patients with pronounced focal perfusion reductions. Functionally unsatisfactory results were obtained with low-degree diffuse perfusion reductions of one hemisphere. The results permit to derive criteria for the surgical indication.

Adult↗