Biomedical subjects

K Schulte

Publications and source records attributed to K Schulte.

46 records · Page 3Linked to original sources

PubMed1991

[Thrombolytic treatment of retinal arterial occlusions with plasminogen activator].

Tissue-type plasminogen activator (rt-PA), a gene-technologically manufactured fibrinolytic compound, has been employed successfully for treatment of cardial and peripheral arterial vascular occlusions. The advantage of this compound is its lytic effect. It selectively displays its effect in therapeutic dosage on fresh thrombuses, showing only minimal influence on physiological clotting as such. Two patients with stop of the retinal arterial bloodflow in videofluorescence angiography were treated with short term lysis with 100 mg rt-PA, the onset of therapy was 7 and 6.5 hours after loss of vision. Already during the infusion of the compound reperfusion was achieved. Inspite of the relatively late onset of treatment, the visual fields of both patients improved. We assume lytic therapy with rt-PA to be an effective therapy for patients with retinal arterial occlusion, if applied within the first eight hours after acute loss of vision. The number of patients who could potentially benefit from this therapy is limited considering the high rate of spontaneous reperfusion before the first eye exam in 84% of the cases and considering the manifold contraindications for this therapy: 35% of the patients above 70 years of age, 56% of the patients with arterial hypertension (RR 160/100 and above) as well as 10% of the patients treated with Coumarine-derivatives should not undergo lysis. Only 43% of the patients with occlusion of central retinal artery and 21% of the patients with occlusion of retinal branch arteries received the first eye exam within the first 8 hours after the occlusion.

Adult↗

PubMed1989

[Effect of beta blockers on retinal hemodynamics. A double-blind study in healthy probands].

In a randomized double-blind study the effect of topically applied Timolol (Chibro-Timoptol 0.5%) on the retinal circulation was investigated. In order to quantify the retinal hemodynamics 20 healthy volunteers were examined twice using video fluorescein angiography. The arteriovenous passage time (AVP) and the dye bolus velocity (MDV) were quantified using an image-analyzing system. Following administration of Timolol, IOP decreased from 14.5 +/- 1.9 mm Hg to 9.4 +/- 1.7 mm Hg (P less than 0.010). The study also showed that there was a significant reduction in AVP from 1.75 +/- 0.5 s to 1.56 +/- 0.3 s (P less than 0.05) and an increase in MDV following local application of Timolol. No effect on systemic blood pressure or pulse rate was observed. The results indicate that in addition to its pressure-lowering effect, timolol also leads to increased retinal perfusion.

Adult↗

PubMed1989

Kinematics of the cervical spine following discectomy and stabilization.

The immediate biomechanical stability of the cervical spine following discectomy and stabilization is described. Fresh human ligamentous spines (C2-T2) were potted, and clinically relevant loads were applied by a loading frame attached to the C2 vertebra of each specimen. A set of three infrared light-emitting diodes (LEDs) were attached rigidly to each of four vertebrae (C4 to C7) to record their spatial locations after each load step application using a Selspot II (Selcom Selective Electronic, Inc., Valdese, North Carolina) system. The specimen was tested in the intact state, following discectomy at the C5-6 intervertebral level, following insertion of a bone graft in the intervertebral space, and following the application of an anterior metal plate. The load-deformation data of the injured and stabilized tests were normalized with regard to the corresponding results of the intact specimens. At the injured level (C5-6), the load-deformation results indicated a highly significant increase in motion in flexion (66.6%), extension (69.5%), lateral bending (41.3%), and axial rotation (37.9%). After the insertion of the bone graft, a significant decrease in motion was seen in the effected segment in extension (-45.9%), with similar reductions in lateral bending and axial rotation and a smaller reduction in flexion. The application of an anterior metal plate in addition to the bone graft at the injured level provided significant reduction in motion (-70%) in all load modalities. This data may have clinical relevance regarding the role of internal fixation in cases of severe spine instability.

Biomechanical Phenomena↗

PubMed1987

Effect of rioprostil, a synthetic prostaglandin E1 on meal-stimulated gastric acid secretion and plasma gastrin levels in humans.

The effects of rioprostil (a newly developed synthetic prostaglandin E1 analogue) on meal-stimulated gastric acid secretion was evaluated in 8 healthy human volunteers. Gastric acid output was measured by intragastric titration on 4 different occasions. The following procedure was invariably employed: after a basal period of 45 min, 5 peptone meals (8%, 500 ml each) were given intragastrically in 45-min intervals and gastric acid output was measured continuously. 45 min after the first meal, either placebo or 150, 300 or 600 micrograms of rioprostil were given intragastrically in a randomized order and on different days. 15 min later, the second meal was given and intragastric titration continued. Rioprostil caused a dose-dependent inhibition of the 3-hour integrated gastric acid response to the peptone meals. The percentage of inhibition was 41, 68 and 79%, respectively, for 150, 300 and 600 micrograms of rioprostil. Whereas the inhibition by the two highest doses was statistically significant, this was not the case for the lowest dose of rioprostil. The integrated 3-hour plasma gastrin response to the peptone meals was not significantly changed by any of the doses of rioprostil. No significant adverse effects were observed with rioprostil.

Adolescent↗

PubMed1984