Showing papers by "University of Graz published in 1986"
01 Aug 1986
TL;DR: A new technique for half-space and simplex range query using random sampling to build a partition-tree structure and introduces the concept of anε-net for an abstract set of ranges to describe the desired result of this random sampling.
Abstract: We present a new technique for half-space and simplex range query using O(n) space and O(na) query time, where a 0. These bounds are better than those previously published for all d ≥ 2. The technique uses random sampling to build a partition-tree structure. We introduce the concept of an e-net for an abstract set of ranges to describe the desired result of this random sampling and give necessary and sufficient conditions that a random sample is an e-net with high probability. We illustrate the application of these ideas to other range query problems.
378 citations
TL;DR: It turns out that the standard Euclidean Voronoi diagram of point sets inRd along with its order-k generalizations are intimately related to certain arrangements of hyperplanes, and this fact can be used to obtain new Vor onoi diagram algorithms.
Abstract: We propose a uniform and general framework for defining and dealing with Voronoi diagrams. In this framework a Voronoi diagram is a partition of a domainD induced by a finite number of real valued functions onD. Valuable insight can be gained when one considers how these real valued functions partitionD ×R. With this view it turns out that the standard Euclidean Voronoi diagram of point sets inRd along with its order-k generalizations are intimately related to certain arrangements of hyperplanes. This fact can be used to obtain new Voronoi diagram algorithms. We also discuss how the formalism of arrangements can be used to solve certain intersection and union problems.
346 citations
TL;DR: A regulatory role for β 2 -glycoprotein-I is suggested in the pathway of blood coagulation because it causes a reduction of the prothrombinase binding sites of these coagulations factors to platelets or phospholipid vesicles.
297 citations
TL;DR: Results indicate that capsaicin-sensitive afferent neurons are involved in gastric mucosal protection against ulcerogenic factors, and suggest that this type of gastric defense is primarily due to a local mechanism initiated by sensory nerve endings in the gastrics mucosa.
252 citations
TL;DR: Compared to malonaldehyde, 4-hydroxynonenal exhibits a much higher capacity to modify LDL and it is believed that this aldehyde is a more likely candidate for being responsible for LDL modification under in vivo lipid peroxidation conditions.
235 citations
TL;DR: C capsaicin releases several bioactive peptides from sensory neurons which may mediate the acute algetic effect of chemical irritants.
198 citations
TL;DR: The rate of 4-hydroxynonenal formation is highest during the very initial phase of its formation and the onset does not show a lag phase, suggesting a transient intermediate predominantly formed during the early phase of microsomal lipid peroxidation.
169 citations
TL;DR: In all blood vessels tested, NPY depresses the TNS-evoked [3H]NA secretion via a nifedipine-resistant action and exerts a variable, Ca2+-dependent vasoconstrictor effect and enhancement of NA and TNS contractions.
Abstract: The effects of porcine neuropeptide Y (NPY) regarding sympathetic vascular control were studied in vitro on isolated rat blood vessels. The 10 -9 M NPY enhanced (about two-fold) the contractile responses to transmural nerve stimulation (TNS), noradrenaline (NA) and adrenaline (about two-fold) in the femoral artery. Higher concentrations of NPY (> 10-8 M) caused an adrenoceptor-resistant contraction per se. The TNS-evoked [3H]NA efflux was significantly reduced by NPY in a concentration-dependent manner (threshold 10 -9 M). The calcium antagonist, nifedipine, abolished the contractile effects of NPY and the NPY-induced enhancement of NA contractions but did not influence the prejunctional inhibition of [3H]NA release. Receptor-binding studies showed that the ratio of alpha1- to alpha2-adrenoceptors in the femoral artery was 30:1. The NPY did not cause any detectable change in the number of alpha1- or alpha2-adrenoceptor binding sites or in the affinity of alpha2-binding sites, as revealed by prazosin- and clonidine-binding, respectively. The NPY also inhibited the TNS-evoked [3H]NA release (by 42–86%) in the superior mesenteric and basilar arteries and in femoral and portal veins. The NPY still depressed TNS-evoked [3H]NA secretion from the portal vein in the presence of phentolamine. The NPY caused a clear-cut contraction in the basilar artery, increased the contractile force of spontaneous contractions in the portal vein, while only weak responses were observed in the superior mesenteric artery and femoral vein. The NA-induced contraction was markedly enhanced by NPY in the superior mesenteric artery, only slightly enhanced in the portal vein and uninfluenced in the femoral vein. In conclusion, in all blood vessels tested, NPY depresses the TNS-evoked [3H]NA secretion via a nifedipine-resistant action. Furthermore, NPY exerts a variable, Ca2+-dependent vasoconstrictor effect and enhancement of NA and TNS contractions.
165 citations
TL;DR: It was not possible to establish any defined target areas within the heart for vagal or spinal SP-IR afferents by use of immunohistochemical methods, and NPY and TH-IR nerves were also almost totally absent in the heart after bilateral stellatectomy.
Abstract: The localization and origin of substance P (SP)-, neuropeptide Y (NPY)-, and noradrenaline/tyrosine hydroxylase (NA/TH)-immunoreactive (IR) nerves in the guinea-pig heart were investigated by means of immunohistochemistry; quantitative analysis was performed by radioimmunoassay (NPY) and high performance liquid chromatography (NA). Both untreated animals and animals subjected to stellatectomy, combined stellatectomy and local capsaicin pretreatment of the vagal nerves or systemic application of capsaicin were studied. A dense network of SP-IR nerves was observed in the right atrium in different locations: (1) around local cardiac ganglion cells, (2) close to blood vessels, (3) within the myocardium, and (4) close to and within peri and endocardium. A moderately dense SP-innervation, mainly related to blood vessels, was found in the ventricles. Very dense networks of NPY and TH-IR nerve fibers with an overlapping distributional pattern around blood vessels and in the myocardium were seen in both the atria and the ventricles. In addition, some cell bodies in local cardiac ganglia were NPY-IR. Bilateral stellatectomy resulted in a reduction of SP-IR in the right atrium (55% of control), which was more pronounced after additional capsaicin pretreatment of the vagal nerves (44% of control). In the left ventricle no significant depletion of SP-IR was seen by either stellatectomy or combined stellatectomy and capsaicin treatment of the vagal nerves. It was not possible to establish any defined target areas within the heart for vagal or spinal SP-IR afferents by use of immunohistochemical methods. Systemic capsaicin treatment caused a total loss of SP-IR nerves in the heart. After bilateral stellatectomy the levels of NPY-IR and NA were reduced to about 10% of control in both the right atrium and left ventricle. In accordance, NPY and TH-IR nerves were also almost totally absent in the heart after bilateral stellatectomy.
146 citations
TL;DR: Since 4-hydroxyalkenals have been shown to originate from biomembrane lipids peroxidation, these findings should be taken into consideration in the assessment of the genotoxic role of lipoperoxidation in humans.
Abstract: The cytotoxic and genotoxic activities of 4-hydroxypentenal (HPE), 4-hydroxyhexenal (HHE), 4-hydroxyoctenal (HOE), 4-hydroxynonenal (HNE) and 4-hydroxyundecenal (HUE) were investigated in Chinese hamster ovary (CHO) cells. All five 4-hydroxyalkenals reduced plating efficiency in a concentration (ranging from 7 to 170 μM) lower than that producing a parallel reduction of trypan blue-excluding cells, but with both methods the increase in molarity needed to obtain a lethal effect was constantly rather small. With all five 4-hydroxyalkenals a significant amount of DNA fragmentation, as revealed either by the alkaline elution assay or by alkaline denaturation followed by chromatographic partition of single- and double-stranded DNA, was detected only after cell exposure to a cytotoxic concentration. HPE, HHE and HOE induced a clear-cut increase of sister-chromatid exchange (SCE) frequency, while that displayed by cells treated with HNE, and HUE was minimal, even if dose-dependent and statistically significant. Since 4-hydroxyalkenals have been shown to originate from biomembrane lipids peroxidation, these findings should be taken into consideration in the assessment of the genotoxic role of lipoperoxidation in humans.
TL;DR: Capsaicin evokes release of several tachykinins from both central and peripheral endings of primary afferent neurons, and the peptides released from sensory nerves in the periphery may induce effects such as protein extravasation and smooth muscle contraction.
TL;DR: From the end of 1979 to September, 1985, radical pelvic lymphadenectomy was performed at the Graz Clinic in 123 cases of Stages IA to IV ovarian cancer following maximum debulking procedure.
TL;DR: In this article, the change in fluorescence intensity of a buffered pH indicator solution entrapped in silicone rubber is measured via an optical fibre bundle, and the effects of sensor preparation and buffer composition on response time, reversibility and sensitivity are discussed.
TL;DR: By dilating airways and evacuating trapped gas, this method of PEP mask PT improves lung function and mucus clearance in CF and thorough practice with the technique and frequent control of the optimal resistance are mandatory.
Abstract: Twenty patients with cystic fibrosis (CF) were trained to mobilize intrabronchial secretions by a new method of positive expiratory pressure mask (PEP mask) physiotherapy (PT). Patients repeatedly expired forcefully through the PEP mask; expiratory resistance was varied by eight different internal diameter resistors at the outlet. Forced vital capacity with the mask (FVCPEP) was determined for each resistor and was compared with the one measured without the instrument (FVC); simultaneously the sustained expiratory pressure (SEP) developed against the resistance was recorded. After training, each patient exceeded FVC with one or more resistors; "optimum" FVCPEP was 124 +/- 16% FVC at a SEP of 61 +/- 21 cm H2O. Using the PEP mask, patients cleared a higher percentage of their daily sputum volume than with conventional PT (78 +/- 22% versus 53 +/- 17%, p less than 0.01). In 11 patients (subgroup 1), multiple aspects of lung function were measured at the beginning of the study, after 10 months with PEP mask PT, after two further months without using the mask but with conventional PT, and after six more months with PEP mask PT. Results showed significantly increased expiratory flow rates, significantly decreased hyperinflation and airway instability with PEP mask PT, and a marked decline of lung function without it. The remaining nine patients (subgroup 2) entered into the same protocol; based on findings in subgroup 1 and on ethical considerations, however, the control period without PEP mask PT was then omitted, resulting in a steady and statistically significant improvement of lung function over the entire observation period. In the course of preliminary trials, two children transiently used a suboptimal resistance (FVCPEP less than FVC) and responded with a deterioration of lung function. By dilating airways and evacuating trapped gas, this method of PEP mask PT improves lung function and mucus clearance in CF. Thorough practice with the technique and frequent control of the optimal resistance are mandatory.
TL;DR: These cDNA clones and the RNA probes derived therefrom were used to detect specifically mRNAs by Northern-blot assays of RNAs from various carcinomas and cultured carcinoma cells, and the specificity and sensitivity of this procedure were demonstrated.
TL;DR: It is concluded that both cerebellar haemorrhage and infarction should be operated on as soon as progressive deterioration of consciousness develops, which occurs more frequently in patients with cerebellary haemOrrhage than with Cerebellar infarctions.
Abstract: This report summarizes the outcome of 56 patients with cerebellar lesions of vascular origin, 40 patients with cerebellar infarction, and 16 with spontaneous cerebellar haemorrhage. All patients had computerized tomography: occlusive hydrocephalus was diagnosed in 75% of patients with cerebellar haemorrhage and in 23% with cerebellar infarction. Nine out of 10 patients survived after early surgical evacuation of the haematoma and 4 of them recovered completely. Two patients underwent only external ventricular drainage (EVD), one died after 2 days, and the other recovered with a moderate deficit. Three of 4 medically treated patients died within one week; all had developed occlusive hydrocephalus. The fourth medically treated patient recovered completely; consciousness had never deteriorated nor had occlusive hydrocephalus developed. Among 40 patients with cerebellar infarction, 13 developed progressive deterioration of consciousness; 7 of them underwent decompressive craniectomy of the posterior fossa and survived. One patient had only external ventricular drainage and died. Four out of the 5 medically treated patients died during the acute phase. From these observations and several reports in the literature, it is concluded that both cerebellar haemorrhage and infarction should be operated on as soon as progressive deterioration of consciousness develops. This occurs more frequently in patients with cerebellar haemorrhage than with cerebellar infarction. Individual decision-making in each case necessitates intensive neurosurgical observation.
TL;DR: In this paper, a collaborative project on cement paste pore solution analysis has been carried out by Institutes in Sweden, Denmark and Austria to determine: (i) the reproducibility of the pore expression method; (ii) the effect of added chlorides on the OH − concentration of OPC pastes from the three countries and (iii) the influence of flyash, slag and silica fume additions on the degree of chloride binding by the cement.
TL;DR: Although immunoreactivity of calcitonin gene-related peptide (CGRP) was detected in mouse spinal cord, CGRP caused no behavioral reactions, nor did it significantly affect thermo- or chemonociception or the scratching induced by SP.
TL;DR: Data suggest that PGE2 may be an important intermediate in the transduction mechanism leading to 5-HT-induced intestinal secretion, and that physiologic doses of P GE2 may act by facilitating calcium entry, rather than by increasing intracellular calcium through activation of the adenylate cyclase.
TL;DR: A new data structure is described which stores S in O(n) space and allows us to answer a halfplanar range query in O (n log 2 (1+√5)−1) time in the worst case, thus improving the best result known before.
TL;DR: In this paper, a new type of oxygen-sensitive material is obtained by preparing an aqueous emulsion of a solution of an oxygen sensitive fluorescent dye in a rigid polymer, and the fluorescence of this emulsion is related to the oxygen partial pressure, but a Stern-Volmer plot is not linear over the whole pressure range.
Abstract: A new type of oxygen-sensitive material is obtained by preparing an aqueous emulsion of a solution of an oxygen-sensitive fluorescent dye in a rigid polymer. The fluorescence of this emulsion is related to the oxygen partial pressure, but a Stern-Volmer plot is not linear over the whole pressure range. Aside from high sensitivity and specificity for oxygen, this new type of sensing material has favorable analytical wavelengths allowing the use of low-cost opto-electronic equipment. Since the indicator is embedded in an aqueous environment, the sensor should be capable of monitoring various kinds of reactions occurring in the aqueous phase, for instance enzymatic reactions which are accompanied by production or consumption of oxygen.
TL;DR: This study substantiates the independent metabolic control of Lp-a, as compared to plasma apolipoprotein-B and total cholesterol, as well as the hormones hCG, human placenta lactogen, progesteron, estradiol, and insulin, during pregnancy and post partum.
Abstract: The changes in plasma lipoprotein-a Lp-a concentations during pregnancy were investigated. Out of 42 women with normal pregnancy, 22 reached Lp-a values greater than 10 mg/dL. Plasma levels of Lp-a in addition to total cholesterol, and apolipoprotein B were measured at 4 to 6-week intervals during pregnancy and post partum. The hormones hCG, human placenta lactogen, progesteron, estradiol, and insulin were measured concomitantly. The results can be summarized as follows: (1) Plasma Lp-a concentrations rose steadily during the first trimester of pregnancy and reached a maximum in the middle of the second trimester. Maximal Lp-a values in the 19th week on average were 2.8 times higher as compared to the values of the eight week of pregnancy. Plasma Lp-a fell from the 19th week of pregnancy, reaching a basal value at the time of birth. This value remained virtually unchanged until 6 months post partum. (2) Despite the fact that apolipoprotein-B and total cholesterol rose significantly, exhibiting pronounced maxima during the course of pregnancy, there was no overlap in the shape of their concentration curve with Lp-a. (3) The rise in plasma Lp-a concentration did not correlate with any of the measured hormones at a given time interval. Time shifted analysis of the concentration curve revealed a correlation with hCG, however, with a lag phase of approximately 11 weeks. This study substantiates the independent metabolic control of Lp-a, as compared to plasma apolipoprotein-B and total cholesterol.
Journal Article•
TL;DR: It is shown that the pathologic process of MB formation involves changes in cytokeratin organization and conformation, resulting in the accessibility of a specific antigenic determinant which is inaccessible ("masked") in the heterotypic tetramer subunit and in the cytokersatin filaments of normal cells.
TL;DR: In this article, the state of the art in optical sensing technology is briefly described in this review, and major advantages of this type of sensor over others include cheapness, ease of miniaturization and the renunciation of reference cells.
Abstract: Recent advances in opto-electronics, (fiber) optics, and optical spectroscopy have led to the development of a fascinating new chemical sensor technique. The present state of the art in optical sensing technology is briefly described in this review. Major advantages of this type of sensor over others include cheapness, ease of miniaturization and the renunciation of reference cells. Among the disadvantages, mention should be made of interference by ambient light, comparatively small analytical ranges, lack of specificity and lack of low-priced lasers.
TL;DR: In this paper, 4-benzoyl-5-phenyl-furan-2,3-dione reacts with various phenylhydrazones at 60-80°C to the pyrazole carboxylic acid, which then can be decarboxylated to 4-bensoyl 1,5-diphenyl-pyrazole (5).
Abstract: 4-Benzoyl-5-phenyl-furan-2,3-dione (1) reacts with various phenylhydrazones2 at 60–80°C to the pyrazole carboxylic acid3 a, which then can be decarboxylated to 4-benzoyl-1,5-diphenyl-pyrazole (5).1 and phenylhydrazine combine again yielding3 a as the main product and the isomeric pyridazinone6 as by-product. At higher temperatures (120–140°C) the reaction of1 with2 a leads to the formation of dibenzoyl acetic acid hydrazide derivatives8.
01 Jan 1986
TL;DR: It is concluded that the glucose-6-phosphatase inactivation during lipid peroxidation can be due to the formation of 4-hydroxynonenal, which implies that a functional SH group of glucose- 6-ph phosphatase is layered in the membrane.
Abstract: 1) The effect of 4-hydroxynonenal and lipid peroxidation on the activities of glucose-6-phosphatase and palmitoyl CoA hydrolase were studied.2) 4-Hydroxynonenal inactivates glucose-6-phosphatase but has no effect on palmitoyl-CoA hydrolase. These effects are similar with those observed during lipid peroxidation of microsomes.3) The inhibition of glucose-6-phosphatase by 4-hydroxynonenal can be prevented by glutathione but not by vitamin E. The inactivation of glucose-6-phosphatase during lipid peroxidation is prevented by glutathione and delayed by vitamin E.4) The formation of 4-hydroxynonenal during lipid peroxidation was followed in relation to the inactivation of glucose-6-phosphatase. At 50% inactivation of glucose-6-phosphatase the 4-hydroxynonenal concentration was 1.5μM. To obtain 50% inactivation of glucose-6-phosphatase by added 4-hydroxynonenal a concentration of 150μM or 300μM was needed with a preincubation time of 30 and 60 min, respectively.5) It is concluded that the glucose-6-phosphatase ...
TL;DR: In this article, the influence of column reinforced soft clays on the settlement and failure load of rafts on a circular footing has been analyzed using a finite element code and results for a circle footing are presented.
TL;DR: Trichoderma reesei was grown on sulfite pulp and the major cellobiohydrolase of the culture filtrate was purified to homogeneity and the distance distribution function p(r) measured by the small angle X-ray scattering technique indicates that the enzyme molecule has a rather unusual tadpole like shape with an isotropic head and a long tail.
Abstract: Trichoderma reesei was grown on sulfite pulp and the major cellobiohydrolase of the culture filtrate was purified to homogeneity. The distance distribution function p(r) measured by the small angle X-ray scattering technique indicates that the enzyme molecule has a rather unusual tadpole like shape with an isotropic head and a long tail. The maximum length is 18 nm and the largest diameter is 4.4 nm.