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  • Digitale Medien  (13)
  • 1990-1994  (11)
  • 1975-1979  (2)
  • 1
    ISSN: 1520-5126
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    s.l. : American Chemical Society
    Journal of the American Chemical Society 114 (1992), S. 4941-4943 
    ISSN: 1520-5126
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 25 (1975), S. 0 
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract— Cyclic 3′,5′-AMP (cAMP) and cyclic 3′,5′–GMP (cGMP) phosphodiesterase activities were found in human cerebrospinal fluid (CSF) using low substrate concentration (0.4μM). More rapid hydrolysis of cGMP than that of cAMP was observed in human CSF. However, cGMP hydrolytic activity of CSF was very much lower (0.3 pmol/min/ml CSF) than that of human cerebral cortex (33.7 nmol/min/g wet cortex). The pH optimum was found to be 8.0 (cGMP phosphodiesterase) and 7.5 (cAMP phosphodiesterase). The maximum stimulation of both cAMP and cGMP phosphodiesterase was achieved at 4 mM-MgCl2. Cyclic AMP had relatively little effect on the hydrolysis of cGMP in CSF and the cortex, while cGMP inhibited hydrolysis of cAMP in both tissues. Snake venom was found to stimulate cAMP and cGMP phosphodiesterase activity of CSF, by 60% and 110% respectively. This stimulation by snake venom was also observed in the cortex phosphodiesterase, but was not observed in human plasma or thyroid phosphodiesterase. When CSF was applied to Sepharose 6B column, cGMP phosphodiesterase was separated into three different molecular forms. A plot of activity against substrate concentration using peak I (largest molecular size) revealed a high affinity (Km= 2.6μM) and a low affinity (Km= 100μM) for cAMP suggesting the existence of at least two molecular forms of the enzyme. On the other hand, using a cGMP as substrate the only one Km value (1.90 μm) was obtained. These Km values of CSF enzymes described above were close to those obtained from human cerebral cortex preparations. The enzyme under peak I corresponded to the cortex enzyme when judged from its molecular size and stimulation by snake venom. It seems likely from our results that at least a part of CSF phosphodiesterase originates from the central nervous system.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 95 (1991), S. 9042-9044 
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
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  • 5
    ISSN: 1432-0533
    Schlagwort(e): Pituitary adenoma ; Monoclonal antibody Ki-67 ; Anti-DNA polymerase α monoclonal antibody ; Bromodeoxyuridine ; Nucleolar organizer regions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The growth potential of 65 pituitary adenomas was determined by histochemical analysis with Ki-67 and anti-DNA polymerase α monoclonal antibodies, bromodeoxyuridine (BrdUdR) labeling, and counts of argyrophilic nucleolar organizer regions (Ag-NORs). The mean proliferating cell indices (PCIs) determined by Ki-67 and anti-DNA polymerase α and the BrdUdR labeling index (LI) were generally very low [1.0±0.2%, 1.1±0.2%, and 0.5±0.1% (±SE), respectively]. Apart from adrenocorticotropic hormone-positive adenomas, which had significantly higher indices, there were no statistically significant differences in the indices among the other subtypes of pituitary adenomas. Recurrent tumors had higher Ki-67 and DNA polymerase α PCIs and BrdUdR LIs (3.6%, 4.2%, 1.4%) than primary tumors (0.8%, 0.8%, 0.3%; P〈0.005). The number of Ag-NORs did not correlated significantly with any of the three indices. The mean number of Ag-NORs was higher in nonfunctioning adenomas than in functioning adenomas (2.04 vs 1.66, P〈0.005); among prolactin-positive adenomas, those treated preoperatively with bromocriptine had more Ag-NORs than untreated tumors (1.75 vs 1.57, P〈0.005). These results suggest that the Ki-67 and DNA polymerase α PCIs and the BrdUdR LI predict the growth potential of individual pituitary adenomas, whereas the number of Ag-NORs appears to correlate with hormone production rather than with the proliferative potential.
    Materialart: Digitale Medien
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  • 6
    ISSN: 0942-0940
    Schlagwort(e): HA1077 ; cerebral vasospasm ; subarachnoid haemorrhage ; cerebral blood flow ; calcium antagonist
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We examined the effects of the recently developed calcium antagonist HA1077 on cerebral haemodynamics during the chronic stage of the two-haemorrhage canine model system of vasospasm. Regional cerebral blood flow (rCBF), regional cerebral blood velocity and regional cerebral blood volume in the canine parietal cortex were measured by Laser-doppler flowmeter. On the 7th day after the initial injection of autogenous blood, subarachnoid haemorrhage (SAH) produced a significant decrease in rCBF (59% of control, p〈0.05) and Hood velocity (48% of control, p〈0.05), with no remarkable change in blood volume (108% of control). Bolus intravenous administration of HA1077 (0.1–0.3 mg/kg) dose-dependently increased the rCBF and blood velocity, without significantly changing the blood volume on Day 7 after SAH. HA1077 improves haemodynamic function manifested by an increase in rCBF and velocity in this SAH model, and may be suitable for the treatment of vasospasm in patients with SAH.
    Materialart: Digitale Medien
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  • 7
    ISSN: 0942-0940
    Schlagwort(e): Tumour consistency ; meningiomas ; MRI ; T 2-weighted image
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The findings on magnetic resonance imaging (MRI) in 73 surgically verified intracranial meningiomas were correlated with their histology and consistency during resection. T 1-weighted imaging was least useful since most of the tumours were iso-intense, similar to cortical grey matter regardless of histology or tumour consistency. The signal intensity on T 2-weighted images was found to best correlate with both the histology and consistency of the meningioma. Generally, the low intensity portion of the tumour on T 2-weighted images indicated a more fibrous and harder character, while the higher intensity portions indicated a more soft character. Most of the fibroblastic meningiomas showed the features of a hard tumour while angioblastic tumours showed the features of soft tumours. Tumours predicted to be harder on MR imaging generally took longer to resect than softer ones, and this relationship was shown best for the larger tumours. Using linear regression analysis, it appears that operative time for soft tumours is more affected by factors other than tumour consistency. Blood loss during surgery was also unrelated to the consistency of the tumour. These results suggest that the histology and consistency of meningiomas may be predictable from findings on T 2-weighted imaging, and this may also predict the difficulty and time required for resection.
    Materialart: Digitale Medien
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  • 8
    ISSN: 0942-0940
    Schlagwort(e): Subarachnoid haemorrhage ; chronic cerebral vasospasm ; calcium antagonist ; AT877 ; HA 1077
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The initial dose-escalating clinical trial of a novel calcium antagonist, AT877, in patients with aneurysmal subarachnoid haemorrhage is reported. AT877 is characterized by its strong spasmolytic activity, its inhibition of intracellular calcium ion activity, and the inhibiton of several protein kinases. A total of 113 patients (Hunt and Hess grades I to IV) who had undergone surgery within 3 days of aneurysmal rupture entered the study. Patients were divided into 5 groups according to the total daily dose of AT877: I: 20 mg; II: 40 mg; III: 60 mg; IV: 90 mg; and V: 120–180 mg. AT877 was given by intravenous infusion over 30 min two or three times a day for 14 days after surgery. Although AT877 did not completely abolish angiographic vasospasm, severe vasospasm was seen less frequently in patients given higher doses. Vasospasm was the cause of a poor clinical outcome (Glasgow outcome scale rating 3 or greater) in 19%, 7%, 9%, 8%, and 6% of the patients in groups I to V, respectively. The results indicated a favourable clinical effect of AT877 at doses above 40 mg per day. Only mild hypotension was seen, even when 60 mg of AT877 was infused over 30 min. AT877 appears to be effective in patients with subarachnoid haemorrhage. Part of its effect may be attributable to protection of the brain from ischaemic insults due to chronic cerebral vasospasm. However, the drug still needs to be evaluated in a placebo-controlled double-blind trial (which is currently being carried out).
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Acta neurochirurgica 103 (1990), S. 71-75 
    ISSN: 0942-0940
    Schlagwort(e): Ischaemic oculopathy ; venous stasis retinopathy ; neovascular glaucoma ; rubeosis iridis ; STA-MCA anastomosis ; EC-IC bypass surgery
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Effects of STA-MCA anastomosis on two patients with neovascular glaucoma due to occlusion of the internal carotid artery are presented. Both patients improved in visual acuity and central retinal artery pressure as well as in signs of transient ischaemic attack. Postoperative angiography showed a marked decrease in collateral flow through the ophthalmic artery, which is reversed from the normal direction, with the development of blood flow through the anastomosis. Discussion is offered indicating that the lack of collateral flow through both the anterior and posterior communicating arteries is important in addition to occlusion of the internal carotid artery in order to produce full-blown ischaemic oculopathy such as venous stasis retinopathy, neovascular glaucoma or rubeosis iridis. It is stressed that EC-IC bypass surgery should be performed soon after the appearance of ischaemia and before the development of neovascular glaucoma or rubeosis iridis in order to obtain normal vision. In ischaemic oculopathy the results of EC-IC bypass can be evaluated objectively and quantitatively by many noninvasive neuro-ophthalmological tests which are important in discussing the efficacy of the bypass surgery.
    Materialart: Digitale Medien
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  • 10
    ISSN: 0942-0940
    Schlagwort(e): Endothelin ; neuropeptide Y ; angiotensin II ; cerebral arteries ; cerebral circulation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We have studied the effect of endothelin, an endothelium-derived peptide, on isolated canine and bovine cerebral arteries in vitro and on canine vertebral blood flow (VBF) in vivo. Endothelin produced a dose-dependent contraction of canine and bovine arterial smooth muscle with ED50 values ranging from 4 to 8 nM. The response to endothelin developed slowly and persisted as a sustained contraction. Maximal contraction by endothelin required the presence of extracellular calcium and was independent of the presence of endothelium. The maximal contraction produced by endothelin was approximately 2–3 times greater than that produced by neuropeptide Y or angiotensin II. The injection of endothelin into the vertebral artery decreased vertebral blood flow (VBF) dose-dependently without affecting systemic blood pressure or heart rate. The decrease in VBF produced by endothelin was long-lasting, like that produced by neuropeptide Y, but more potent. The present data, together with our previous study demonstrating that the intracisternal injection of endothelin induces an unusually long-lasting decrease in the basilar artery diameter angiographically, suggests that endothelin may act as a long-acting vasoconstrictor in cerebral vascular disease.
    Materialart: Digitale Medien
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