[An arterial compression syndrome due to the ligamentum arcuatum mediale of the diaphragm].
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Adult↗
Biomedical subjects
R Loose
Publications and source records attributed to R Loose.
Inhibition of lipopolysaccharide (LPS)-induced endothelial cytotoxicity by diosmin.
The cytotoxic effect of lipopolysaccharide (LPS) on cultivated bovine aortic endothelial cells was determined. This LPS-induced cytotoxicity was attenuated by diosmin. That means, the IC50 value of LPS in the combination with 8 mumol/l diosmin was shifted from 31 to 70 ng/ml in a concentration dependent manner. As a hypothesis it was suggested, that the inhibition of LPS-induced cytotoxicity in bovine aortic endothelial cell cultures by diosmin could be probably mediated via inhibition of tyrosine kinases.
Animals↗
[Stent migration with perforation of the portal vein after transjugular intrahepatic portosystemic shunt (TIPS) with a self-expanding stent].
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Alloys↗
A parametric analysis of the 'rate effect' in the sensorimotor cortex: a functional magnetic resonance imaging analysis in human subjects.
We studied the effects of different movement speeds of unimanual right hand movements on functional magnetic resonance signal changes in the sensorimotor cortex using echo planar imaging (EPI). Six healthy right-handed subjects were scanned at rest and while executing a finger tapping task with their right index finger. Movement frequency was visually paced at rates ranging from 0.5 to 5 Hz, separated by 0.5 Hz steps. The blood oxygen level dependent (BOLD) response within the left sensorimotor cortex was linearly and positively related to movement frequency. However, this relation holds (r2 = 0.91) only for movement frequencies faster than 1 Hz (1.5-5 Hz). For the slower frequencies there was an initial sharp increase of the BOLD response from 0.5 to 1 Hz followed by an activity drop for 1.5 Hz. These results are compatible with the idea that two different motor control modes are operative during slow or fast movements. During slow movements a computational demanding on-line feedback control mode is operative resulting in strong BOLD signals indicating extensive neural activity. During faster movements on the other hand a program-like motor control mode is operative resulting in less demanding neural computations. The amount of neural computation for the latter control mode increases with increasing movement speed.
Adult↗
Effects of long term treatment with corticotropin releasing factor on corticotropic tumor cells in vitro.
hCRF inhibits proliferation of corticotropic tumor cells cultivated in serum-reduced medium via interaction with CRF-receptors. This effect was attenuated by the specific antagonist hCRF (9-41), but not by a variety of substances which are inhibitors of cAMP production or cAMP-dependent kinases, suggesting that the effect was not mediated via cAMP. The growth inhibiting effect of hCRH was developed after 4 h incubation, a longer hCRF treatment did not change the effect observed after 4 h. Simultaneously, after hCRF treatment for 4 days the cells were insensitive for ACTH release by hCRF stimulation despite of an increase in the number of secretory granules. The results show that the inhibition of proliferation of pituitary tumor cells by hCRF seems to be a rapid receptor-mediated process connected with morphological changes, but not mediated via activation of adenylate cyclase.
Animals↗
Inhibition of lipopolysaccharide (LPS)-induced endothelial cytotoxicity by selected flavonoids.
The cytotoxic effect of lipopolysaccharide (LPS) was examined on bovine aortic endothelial cell proliferation in vitro. This LPS-induced cytotoxicity (IC50 = 22 ng/ml) was attenuated by selected flavonoids, such as catechin, myricetin, quercetin, hesperitin, and rutin. No inhibitory effect was induced by flavones, morin, kaempferol, chrysin and naringin. The isoflavone genistein, and the synthetic tyrphostin B46, both known inhibitors of tyrosine kinases, also attenuated the toxic LPS effect. The hypothesis was framed that the inhibition of LPS-induced cytotoxicity in bovine aortic endothelial cell cultures by flavonoids could be mediated via inhibition of specific tyrosine kinases.
Animals↗
[Contrast-enhanced MR angiography in Leriche's syndrome].
PURPOSE: To determine the usefulness of contrast-enhanced MR angiography for the diagnosis of Leriche's syndrome. MATERIAL AND METHODS: Leriche's syndrome was seen in 7 patients via DSA. In addition, contrast-enhanced MR angiography was performed (TR 7.8 ms/TE 2.1 ms, flip angle 30 degrees, slab thickness 116 mm, slice thickness 1.82 mm, 64 partitions, FOV 500 x 438 mm, matrix 224 x 512). RESULTS: Diagnosis of Leriche's syndrome was possible by contrast-enhanced MR angiography in each case. Visualisation of the femoral arteries was not possible in two patients by intraarterial DSA, in three other patients there was an insufficient contrast in the femoral arteries with DSA. Contrast-enhanced MR angiography revealed good visualisation of the femoral arteries in these patients. In addition, contrast-enhanced MR angiography allowed complete visualisation of the patent lower limb arteries. In intraarterial DSA visualisation of the lower limb arteries was achieved reached in only one patient, but was incomplete. CONCLUSION: Contrast-enhanced MR angiography yielded the correct diagnosis of Leriche's syndrome in all 7 patients. Contrast-enhanced MR angiography was superior to DSA in the assessment of the distal run-off vessels in five of seven patients.
Adult↗
[Intramural hemorrhage of the thoracic aorta].
PURPOSE: Intramural hemorrhage (IMH) of the aorta is considered to be a possible preliminary stage to dissection. We report on our experience with MRI, CT, and TEE in the diagnosis as well as in the correct evaluation of the extent of an IMH. METHOD: Between 1983 and 1997 a total of 26 patients were examined using MRI (n = 13) and/or contrast enhanced CT (n = 18) or TEE. The validation was effected in 17 cases through intraoperative or postmortem inspection and in the remaining cases either through continuous clinical or radiological monitoring (n = 6) or through the depiction of the results in 2 different imaging procedures (n = 3). RESULTS: The correct diagnosis of an IMH was made on all examined patients with all imaging modalities. In all cases, MRI enabled the correct identification of the affected aortic segments. Using CT the affected descending aorta was overlooked in one out of 15 cases; TEE failed in one out of two cases of intramural hemorrhage in the aortic arch. A false positive diagnosis was made with CT in one out of 9 cases in the ascending aorta, and using sonography, this occurred in two out of 3 cases in the area of the aortic arch. CONCLUSION: According to our experience, magnetic resonance imaging is the most accurate method for the diagnosis of an IMH.
Adult↗
Computer tomographic assessment of perfluorocarbon and gas distribution during partial liquid ventilation for acute respiratory failure.
The average in vivo chest computed tomographic (CT) attenuation number (air = -1,000, soft tissue = 0, perflubron = +2,300 Hounsfield units [HU]) of 10 ventrodorsal-oriented lung segments was calculated to assess the distribution of gas and perflubron in 14 oleic acid lung-injured adult sheep during partial liquid ventilation (PLV, n = 7) or gas ventilation (GV, n = 7). Partial liquid ventilation was associated with a significant decrease in shunt fraction (PLV = 40 +/- 12%, GV = 76 +/- 12%, p = 0.004). Computed tomographic attenuation data during expiration (HUexp) demonstrated minimal gas aeration in GV animals in the dependent (segments 6-10) lung zones (HUexp = -562 +/- 108 for segments 1-5, HUexp = -165 +/- 104 for segments 6-10, p = 0.015). During PLV, perflubron was predominantly distributed to the dependent lung regions (HUexp = 579 +/- 338 for segments 1-5, HUexp = 790 +/- 149 for segments 6-10, p = 0.04). The ratio of the inspiratory to expiratory HU (HUinsp/exp) was greater in dependent than nondependent regions (mean HUinsp/exp segments 1-5 = 0.56, segments 6-10 = 0.81, p = 0.01), indicating that during inspiration relatively more gas than perflubron was distributed to the nondependent lung regions. We conclude that during PLV in this lung injury model, (1) gas exchange is improved when compared with gas ventilation, (2) perflubron is distributed predominantly to the dependent regions of the lung, and (3) although gas is distributed throughout the lung with each inspiration, more gas than perflubron goes to the nondependent lung regions.
Acute Disease↗
Electrophysiological evidence for direction-specific rotary evoked potentials in human subjects--a topographical study.
The spatio-temporal characteristics of rotary evoked potentials are unknown up to now. Transient motions with sinusoidal velocity profile (60 degrees , 47.12 degrees /s, 74.02 degrees /s2, duration 2 s) were alternately applied (rightward/leftward) to 12 healthy subjects. Fixation of a target-cross moving with them suppressed the vestibulo-ocular reflex. Quasi-DC-scalp potentials were recorded from a total of 21 equidistant (3 cm) locations (single sweep: 5 s, 0.016-100 Hz). Brain activity evoked by rotary stimulation is dominated by a late, long-lasting component within a mean peak latency of about 1800 ms after motion onset. Topographic distribution over both hemispheres specifically depends upon the direction of rotation and is mirror-symmetric with respect to the sagittal midline. The gradient of the potential field obtained shows its maximum along a lateral orientation corresponding to the temporo-parietal orientation of vestibular cortical projection areas.
Adult↗
[Saving intravenously administered contrast media in CT diagnosis by using multi-phase pumps].
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Contrast Media↗
[Goals, requirements and prerequisites of teleradiology. An assessment of current status].
Specific radiological requirements have to be considered for the realization of telemedicine. In this article the goals and requirements for an extensive introduction of teleradiology will be defined from the radiological user's point of view. Necessary medical, legal and professional prerequisites for teleradiology are presented. Essential requirements, such as data security, maintenance of personal rights and standardization, must be realized. Application-specific requirements, e.g. quality and extent of teleradiological functions, as well as technological alternatives, are discussed. Each project must be carefully planned in relation to one's own needs, extent of functions and system selection. Topics, such as acknowledgement of electronic documentation, reimbursement of teleradiology and liability, must be clarified. Legal advice and the observance of quality guidelines are recommended.
Forecasting↗
Effect of flavonoids on daunomycin-induced toxicity in cultivated endothelial cells.
The cytotoxicity of daunomycin in cultivated endothelial cells was differentially influenced by selected flavonoids. One group (myricetin, flavone, apigenin) enhanced daunomycin toxicity whereas flavonols like quercetin, kaempferol, rutin and morin significantly inhibited this cytotoxicity. Other flavonoids like hesperidin, naringin and catechin did not interact with the daunomycin-induced inhibition of proliferation. There was no correlation between lipophilicity and toxicity of the flavonoids and the observed effects on daunomycin-induced cytotoxity. The protective effect of quercetin and rutin seems to be connected with the antioxidative properties of these flanonols.
Animals↗
[Indications and outcome effectiveness of transpopliteal angioplasty].
PURPOSE: In this retrospective study, the results following angioplasty by the retrograde transpopliteal approach were evaluated to confirm the indications of this technique. PATIENTS AND METHODS: 34 patients were evaluated. Of these 28 were male and 6 were female. Differences to a normal group of patients planned to have angioplasty are the different location of the puncture and on extremely negative selection. RESULTS: Technical success was observed in 84%. A long-term patency ratio of 0.53 was achieved after 30 month. No complications relevant to the therapy were observed. CONCLUSIONS: The transpopliteal approach is a safe and efficient alternative to femoral puncture if the latter is impossible. Compared to the crossover-technique, mechanical considerations favor this technique.
Adult↗
Perception of direction of visual motion. I. Influence of angular body acceleration and tilt.
We investigated, psychophysically, the influence of body rotation on visual motion direction thresholds for both upright sitting and tilted observers. Four angular accelerations (0, 20, 40 and 60 degrees/s2) were combined with 3 concurrent backward-tilt positions (0, 45 and 90 degrees). This led to combined stimulation of the semicircular canals and otoliths. Vestibular stimulation was combined with a visual motion stimulus. Random-dot kinematograms in which varying percentages of pixels coherently moving to the left were presented upon a background of otherwise randomly moving pixels (random walk). The smallest percentage of coherently moving pixels leading to a clear perception of motion direction represented as the perceptual threshold. Angular accelerations about the longitudinal body axis significantly increased motion-direction thresholds. Concurrent backward tilt did not influence thresholds. These results differ from those of studies in which translational linear acceleration was employed. Our results support the view that it is necessary to distinguish between linear acceleration caused by gravitational forces and that caused by additional linear accelerations about the x-, y-, and z-axes.
Acceleration↗
Perception of direction of visual motion. II. Influence of linear body acceleration.
We investigated whether linear whole-body acceleration along the interaural y-axis influenced the concurrent perception of visual motion direction as has been shown for angular accelerations. A sled running on air bearings along a 7.5-m track was used to accelerate 18 subjects at two different linear accelerations. These young, healthy volunteers, aged 25.50 +/- 7.38 years, used a joystick to indicate whether or not they perceived visual motion to the left within a random-dot kinematogram continuously presented on a monitor moving with them. The percentage of coherently leftward moving pixels presented for a 640-ms period during acceleration was adjusted according to a Modified Binary Search (MOBS) procedure. Six conditions were tested, two acceleration levels of 1 and 2 m/s2 to both left and right with, at the higher acceleration, two different times of visual motion presentation. Conditions were sequenced by means of a 6 x 6 Latin square balanced for order and carry over. A MANOVA did not show any statistically significant effects either for the independent variables acceleration, velocity, and direction of motion of the sled or for their interactions. The results obtained are in clear contrast to those obtained under rotatory stimulation. We conclude that the otolithic contribution to vestibular-visual motion processing is negligible.
Acceleration↗
[The value of colloid scintigraphy and erythrocyte scintigraphy in detecting acute or intermittent gastrointestinal hemorrhages].
PURPOSE: In a retrospective analysis the diagnostic value of two scintigraphic methods was compared with each other. METHOD: 104 patients with acute or intermittent gastrointestinal haemorrhage were examined with 121 scintigraphic studies. We compared scintigraphic results with surgical findings, endoscopic results or final clinical diagnosis. We used two scintigraphic methods, colloid scintigraphy and in vivo/vitro red blood cell scintigraphy. RESULTS: Our scintigraphic findings reached a sensitivity of 72% and a specificity of 100%. We calculated a sensitivity of 68% for colloid scintigraphy and a sensitivity of 79% for red blood cell scintigraphy. The correct localisation of bleeding was successful in 52 (98%) cases. CONCLUSIONS: Our results demonstrate that red blood cell scintigraphy is the method of choice in detecting intermittent gastrointestinal hemorrhage. We believe that with new preparation kits for in vivo labelling red blood cell scintigraphy will become seriously competitive for the colloid scintigraphic method.
Acute Disease↗
Position and velocity responses from the otoliths and the canals: results from ESA's parabolic flights.
BACKGROUND: Transient (i.e., phasic) bell-shaped vestibularly evoked potentials (VESTEP's) were recorded from the human scalp during whole body rotation about the vertical z-axis using a multi-axis rotary chair (yaw-motion). For pitch-motions about the interaural y-axis, however, a sustained (i.e., tonic) VESTEP was recorded, presumably because of the additional otolithic stimulation. HYPOTHESIS: During microgravity, only phasic VESTEP's were recorded because pitch-motions stimulate only the vertical semicircular canals without otolithic contamination. METHODS: The motion profile applied simulated the form of a natural smooth head movement ("raised cosine"). It was designed to minimize all possible sources of mechanical, electrical, and physiological artifacts. With this motion profile, seated subjects were tilted 90 degrees nose-down or 90 degrees nose-up about their interaural y-axis ("pitch") thus stimulating the vertical semicircular canals and the otoliths. In addition, the raised cosine velocity profile was applied during the microgravity phases of a total of 90 parabolic flight maneuvers, thus stimulating the vertical canals without additional otolithic stimulation. RESULTS: A transient (phasic) bell-shaped VESTEP was found in the Earth-bound laboratory for backward-tilts corresponding to the velocity profile used. For nose-down tilts, however, a sustained (tonic) negativity was found which matched the applied position profile. In microgravity, only the transient bell-shaped responses could be recorded irrespective of tilt direction. CONCLUSION: These results are interpreted in terms of both a position response generated by pitch-down and a velocity response caused by pitch-up motions. This differentiation might prove to be a useful electrophysiological tool in oto-neurological diagnosis to distinguish between otolithic and canal disorders.
Adult↗