Showing papers by "University of Graz published in 1982"

Capsaicin and nociception in the rat and mouse. Possible role of substance P.

Abstract: Newborn or adult rats and mice were treated with capsaicin. The effect of systemic or intrathecal treatment on thermonociception, chemonociception, content and release of immunoreactive substance P (I-SP) was investigated.

Evidence that the contractile response of the guinea‐pig ileum to capsaicin is due to release of substance P.

Abstract: 1. The possible roles of substance P and opioids in the contractile response of the isolated guinea-pig ileum to the sensory stimulant drug capsaicin were investigated, and the contractions were found to be inhibited by about 60% in preparations desensitized to substance P. 2. Contractions evoked by stimulation of the mesenteric nerves in the presence of the adrenergic blocking drug guanethidine were inhibited by about 75% after the ileum had been rendered insensitive to substance P. 3. Atropine partially inhibited the effect of capsaicin. The atropine-resistant component of the contractile response to capsaicin was inhibited by more than 85% in preparations desensitized to substance P and almost abolished by the substance P antagonist, (D-Pro2,D-Trp7,9)-substance P. 4. The opioid peptide (D-Met2, Pro5)-enkephalinamide inhibited, whereas the opiate antagonist naloxone enhanced the atropine-resistant contractions in response to capsaicin. 5. The results indicate that the contractile response of the guinea-pig ileum to capsaicin and mesenteric nerve stimulation is mediated by release of substance P, presumably from sensory nerve endings in the gut. Substance P appears to act on the smooth muscle both directly and indirectly via cholinergic neurones. It is proposed that opioids modulate the non-cholinergic response to capsaicin by inhibiting the release of substance P.

Stabbing line segments

Abstract: An algorithm for the geometric problem of determining a line (called a stabbing line) which intersects each ofn given line segments in the plane is presented. As a matter of fact, the algorithm computes a description of all stabbing lines. A purely geometric fact is proved which infers that this description requiresO(n) space to be specified. Our algorithm computes it inO(n logn) time which is optimal in the worst case.

Generating gamma variates by a modified rejection technique

Abstract: A suitable square root transformation of a gamma random variable with mean a ≥ 1 yields a probability density close to the standard normal density. A modification of the rejection technique then begins by sampling from the normal distribution, being able to accept and transform the initial normal observation quickly at least 85 percent of the time (95 percent if a ≥ 4). When used with efficient subroutines for sampling from the normal and exponential distributions, the resulting accurate method is significantly faster than competing algorithms.

Analysis of the effects of intravenously injected capsaicin in the rat.

Abstract: 1. I.v. injection of 1 or 3 micrograms capsaicin led to a triphasic blood pressure response in Sprague-Dawley rats but, in contrast to Wistar rats, did not affect heart rate and respiration. The blood pressure response was a sequence of fall (A), return to normal levels or slight rise (B), and fall (C) in blood pressure. The blood pressure response to capsaicin remained unchanged after treatment with adrenoceptor or cholinoceptor antagonists. 2. The initial fall in blood pressure (A) was absent after bilateral vagotomy and in the pithed rat. The delayed fall in blood pressure (C) remained unchanged after vagotomy, but was absent after neonatal capsaicin pretreatment and in the pithed rat. Effect B was not diminished after vagotomy or despinalization: it was augmented in rats treated neonatally with capsaicin. 3. I.a. injection of capsaicin into the hind leg caused a reflex fall in blood pressure which was changed to a reflex rise in rats treated with capsaicin as neonates. 4. The initial and the delayed fall in blood pressure after i.v. injection of capsaicin seems to be reflex responses to stimulation of capsaicin-sensitive small diameter afferent fibres. The intermediate rise in blood pressure appears to result mainly from a direct short vasoconstriction by capsaicin.

Visceral pain reflex after pretreatment with capsaicin and morphine

Abstract: 1. Distension of the proximal jejunum by increasing the intraluminal pressure for short time periods causes a reflex response in blood pressure of anaesthetized rats which correlates with the magnitude of distension. The blood pressure response consists of a short initial rise followed by a marked decrease for the time of distension. 2. The absence of the depressor response in capsaicin desensitized rats indicates its mediation by C fibre afferents. These afferents are located within the periarterial mesenteric nerves. The depressor response was also elicited by stimulation of these nerves and abolished by local application of percain or capsaicin onto the mesenteric stalk. Vagal afferents were not involved in this depressor response as shown by bilateral vagotomy or by afferent vagus stimulation. 3. The depressor response is absent in spinal rats. Therefore, the location of the reflex centre is assumed to be supraspinal. Because it is augmented by naloxone and abolished by morphine in a naloxone reversible way it is regarded as a nociceptive reflex response. 4. The efferent side of the depressor response is unknown; cholinergic and α-adrenergic activation were excluded. 5. The initial pressor response to intestinal distension or to afferent periaterial mesenteric nerve stimulation persists in capsaicin desensitized rats excluding the involvement of C fibre afferents and in spinal rats indicating that the reflex centre is within the spinal cord. It is not diminished by morphine and therefore not a nociceptive response. Its inhibition by phentolamine suggests an α-adrenergic spinal response to intestinal distension. In control rats the pressor response is greatly overlapped by the much more pronounced depressor response.

Direct separation of amino enantiomers by high performance ligand exchange chromatography on chemically bonded chiral phases

Abstract: Various chiral chemically bonded stationary phases for the separation of amino acid enantiomers by high performance ligand exchange chromatography are described. The phases were synthesized by treating silica gel with 3-glycidoxypropyltrimethoxysilane and bonding L-amino acids such as L-azetidine carboxylic acid, L-pipecolic acid or L-phenylalanine to the product. The best results were obtained with L-pipecolic acid as a fixed ligand. Nearly all common amino acid enantiomers could be separated.

Prevention of symptomatic vasospasm by topically applied nimodipine.

Abstract: A 2.4×10−5M solution of the Calcium-antagonist Nimodipine was administered to the exposed cerebral vessels in 17 patients intraoperatively clipping of a ruptured aneurysm. The interval between subarachnoid haemorrhage and operation was 48 to 72 hours. The CT investigation had revealed blood accumulation in the basal cisterns in all cases. Vasodilatation was observed in all instances; the percentage being greater in small vessels as compared to large vessels. Postoperatively, a neurological deficit combined with angiographically verified vasospasm occurred in two patients, but was reversible in both. Fifteen patients remained free from symptomatic vasospasm and were discharged without neurological deficit. In 13 of these patients and 3 additional cases, a plastic cannula was placed intraoperatively so that postoperative topical administration of Nimodipine was possible. Postoperative control-angiograms after a mean interval of 7 days from SAH did not show severe spasm in any of the patients; localised moderate asymptomatic spasm was found in 8 cases and was reserved in 5. Moderate postoperative symptomatic spasm was observed in 2 patients, treated and reversed in one patient. In 5 of 7 cases without evidence of spasm in the angiogram postoperative topical administration of Nimodipine caused vasodilatation. It is concluded, that topical intracisternal administration of Nimodipine reverses intraoperative vascular spasm and decreases the probability of postoperative symptomatic vasospasm after early surgery.

Genome size and heterochromatin variation in rodents

Abstract: Nuclear DNA amounts are determined in 16 species and the C-banding patterns for 19 species of rodents. A list of rodent DNA amounts is compiled. The fraction of heterochromatin in the genome is determined as the length of C-banded chromosome material relative to the total karyotype length. Among all rodents, heterochromatin amounts tend to be larger in the larger genomes. However, this relationship is not exact and does not hold true for individual genera. In general the notion of a basic rodent genome of defined size to which various amounts of heterochromatin have been added is untenable.

"Extraepithelial enterochromaffin cell--nerve-fibre complexes" in the normal human appendix, and in neurogenic appendicopathy.

Abstract: Extraepithelial, extraglandular endocrine cells of types EC1 and EC2 occur in the lamina propria of the normal appendix. They are more numerous in intramucosal neurogenic appendicopathy. Ultrastructurally there is invariably a close association between the cells and non-myelinated nerve fibres of the mucous plexus. Together they form a complex surrounded by a common basal lamina, and the term enterochromaffin cell-nerve fibre complex (ECC–NF) is suggested for this morphological and funcitional unit. The derivation of extraepithelial EC cells from the glandular epithelial cells could not be established and the existence of the complexes in held to support an origin from neuroendocrineprogrammed ectoblasts.

Solvent- andpH-dependence of the absorption and fluorescence spectra of harman: Detection of three ground state and four excited state species

Abstract: ThepH-dependence of the absorption and fluorescence spectra of the alkaloid harman has been investigated. Three species, namely the cation, the neutral molecule and the anion have been found in absorption, whilst four species, namely the cation, the neutral molecule, the anion and the zwitterion were detected by fluorimetry. The zwitterion must be formed by a double proton transfer during lifetime of the excited state. Fluorescence quantum yields are entirely different for the various species, being highest for the cation (ϕ f in 1N sulfuric acid 0.89).

Function of cyclic GMP in acetylcholine-induced contraction of coronary smooth muscle.

Abstract: Increasing evidence indicates that cyclic GMP is involved in smooth muscle relaxation by various nitrocompounds which stimulate guanylate cyclase Since, however, rises in cGMP were also observed in association with contractile effects, the role of cGMP in acetylcholine-induced contraction was studied in isolated bovine coronary artery strips Concentration response experiments were performed with acetylcholine (ACh) in the absence and in the presence of a) the cGMP-phosphodiesterase inhibitor M & B 22,948, and of b) methylene blue which was found to inhibit NO-, and azide-induced stimulation of guanylate cyclase (Katsuki et al 1977b), and changes in cGMP-levels (RIA) and in smooth muscle tone were monitored

Practical aspects to the use of indirect fourier transformation methods

Abstract: Practical hints for the application of the indirect Fourier transformation method are given. In detail there are discussed the problems of stabilization of the least squares routine, the estimation of the maximum dimension of the particles, the choice of an appropriate number of the spline functions, the combination of scattering functions measured with different primary beam geometry, standard deviation and error propagation of the solution functions, influence of the interparticle interference effect and background scattering on the results, determination of the radius of gyration and the scattering intensity at zero angle and finally the possibility of simulation of measuring curves starting with model bodies is described. It is attempted to demonstrate the advantages of indirect Fourier transformation on hand of several practical examples.

Small‐Angle X‐Ray Scattering Studies of Tryptophan Synthase from Escherichia coli and Its α and β2 Subunits

Abstract: The alpha and beta 2 subunits of tryptophan synthase were investigated by small-angle X-ray scattering. The molecular parameters are: radius of gyration, alpha: 1.95 nm, beta 2: 3.01 nm; maximum particle diameter, alpha: 5.8 nm, beta 2: 10.5 nm; and hydrated volume, alpha: 60 nm3, beta 2 160 nm3. The shape of the alpha subunit can best be described by a circular cylinder, slightly tapered at one end. An elongated elliptical cylinder with its cross section larger in the middle than at the ends was found to be a model equivalent in scattering to the beta 2 subunits. The alpha 2 beta 2 enzyme complex was found to have a radius of gyration of 4.01 nm, a maximum length of 13.5 nm, and a hydrated volume of 270 nm3. No satisfactory fit of the scattering data was obtainable by mere apposition of the models of the alpha and beta 2 subunits. Two cylinders overlapping laterally fit the experimental data considerably better, suggesting changes in the conformation of the subunits on forming the alpha 2 beta 2 complex.

Separable potential for the neutron-proton system

Abstract: A separable potential is proposed for the $n\ensuremath{-}p$ interaction in $^{1}S_{0}$ and $^{3}S_{1}\ensuremath{-}^{3}D_{1}$ partial waves. In the singlet $S$ state the potential fits new phenomenological phases rather accurately in the laboratory kinetic energy range 0-600 MeV; it is also capable of reproducing singlet effective-range parameters in close agreement with experiment. In the coupled state $^{3}S_{1}\ensuremath{-}^{3}D_{1}$ the potential provides a correct description of the deuteron data (${E}_{D}$, ${p}_{D}$, $Q$, $\ensuremath{\eta}$), while at the same time it adequately fits modern phenomenological phases up to ${E}_{\mathrm{lab}}\ensuremath{\gtrsim}500$ MeV in both the $S$ and the $D$ wave; triplet effective-range parameters are also in agreement with experimental data. Only the mixing parameter ${\ensuremath{\epsilon}}_{1}$ deviates from predictions of phase-shift analyses. In the construction of the potential care was taken that its off-shell behavior be reasonable. As an eminent property it thus exhibits an off-shell behavior similar to the one of the Paris potential. In particular the $^{3}S_{1}\ensuremath{-}^{3}D_{1}$ potential yields a deuteron $S$-state wave function, which in momentum space shows a zero like the Paris potential. Still the model is simple enough to be of good use in modern computer codes for few-body systems and other nuclear applications.NUCLEAR REACTIONS Separable potential proposed for $n\ensuremath{-}p$ interaction; fits new on-shell data; off-shell behavior compared to Paris potential.

Chromosomal evolution in the genus Clethrionomys

Abstract: The karyotypes of Clethrionomys rufocanus and C. glareolus are presented using G- and C-banding techniques. There is intraspecific polymorphism in Clethrionomys rufocanus for a pericentric inversion. The main difference between the karyotypes of the two species is considered to result from a reciprocal translocation.

Detection of igg sensitization of red cells with 125I staphylococcal protein A

Abstract: Most cases of immune hemolytic anemia are associated with a positive direct antiglobulin test. However, in some cases, the antiglobulin test is not sensitive enough to detect low levels of red-cell bound antibodies. This report describes a method using radiolabelled purified staphylococcal protein A which is capable of detecting IgG sensitization of red cells beyond the threshold of serologic techniques. It is less cumbersome than previously described methods and does not require antibody purification procedures. Its effectiveness was demonstrated for the detection of red-cell alloantibodies and in evaluation of patients with acquired hemolytic anemias associated with a negative direct antiglobulin test.

TSH, T3, rT3 and fT4 in maximal and submaximal physical exercise.

Abstract: The response of various thyroid hormone parameters to maximal physical exercise (MPE) was investigated in 14 medium and long distance runners and 13 divers. The effect of submaximal long time physical exercise (SMPE) was examined in seven divers. The TSH-level decreases significantly during MPE and slightly rises again after the end of the exercise. In SMPE, however, TSH continuously rises until 15 min after the end of the exercise. The T3 level rises significantly in MPE and falls below the initial value 15 min after the exercise finishes, during SMPE it remains practically unchanged and slightly decreases after the finish. In MPE, the rT3 level does not change and slightly decreases after termination, while the fT4 level continuously decreases from the beginning till 15 min after the exercise period. The latter two parameters do not show any change in SMPE. As possible reasons for the changes of TSH levels a decrease (MPE) or an increase (SMPE) of pituitary secretion might play a role. Furthermore, in MPE the rise in T3 level might be related to hemoconcentration, and the decrease in fT4 level to an elevated cellular utilization.