Search results for "peripheral"

Human surrogate models of neuropathic pain.

2005

Neuropathic pain is defined as pain initiated or caused by a primary lesion or dysfunction in the nervous system (Merskey and Bogduk, 1994). Current efforts to refine this definition focus on the terms ‘dysfunction’ and ‘nervous system’ with the intention to clarify that there has to be an identifiable lesion or disease process affecting the somatosensory system. Experimental models of neuropathic pain according to either one of these definitions are expected to imitate mechanisms of nerve damage within the peripheral or central parts of the somatosensory system and the ensuing processes of degeneration and regeneration. Whereas this approach to model the etiology and pathophysiology of the…

Opioid-Sensitive Peripheral Neuronal Activity in the Modulation of Gastric Mucosal Injury

1991

There is growing evidence that capsaicin-sensitive afferent neurones participate in the protective mechanisms of the gastric mucosa against damage. Animals pretreated systemically with capsaicin, at doses that lead to the ablation of capsaicin-sensitive afferent neurons, show an increase in the level of macro-scopically apparent mucosal damage in different experimental models of ulceration (Szolcsanyi and Bartho, 1981; Holzer and Sametz, 1986). Furthermore, acute stimulation with capsaicin of afferent nerve endings located in the gastric mucosa protects against different ulcerogenic mechanisms (Szolcsanyi and Bartho, 1981; Holzer and Lippe, 1988; Holzer et al., 1989).

Pharmacokinetics and pharmacodynamics of hydroxyethyl starch in hypovolemic pigs; a comparison of peripheral and intraosseous infusion.

1999

Intraosseous (i.o.) infusion is considered a useful technique for the administration of medications and fluids in emergency situations when peripheral intravascular access is not possible. This study investigated the effectiveness of i.o. versus intravenous (i.v.) infusion of hydroxyethyl starch (HES 200/0.5) in hypovolemic pigs. Twenty-three pigs (8- to 9-week-old) were anaesthesized, instrumented and blood was withdrawn (25-30 ml/kg) to50 mmHg mean arterial pressure (MAP). The animals were left untreated in haemorrhage for 30 min. Relevant haemodynamic parameters were monitored and blood samples were collected for blood gas and HES concentration analysis. Infusion of HES via i.v. or i.o. …

Injection pressure mapping of intraneural vs. perineural injections: further lessons from cadaveric studies.

2018

Background The aim of the study was to investigate the difference between intraneural and perineural injection pressures in human cadavers. Targeted nerves included the cervical roots, the supraclavicular and infraclavicular brachial plexus, the sciatic-subgluteal nerve and the common peroneal and tibial nerves. Methods Ten readings were obtained for each nerve location. Over ten seconds, 1 mL of 0.9% NaCl was injected - deliberately slower than in clinical practice to eliminate the risk of aberrant readings relating to the speed of injection. Perineural injections occurred at least 1 mm outside the epineurium. After pressure recordings were completed 0.1mL of dye was injected, and dissecti…

Climate-growth relationships of Quercus gussonei (Borzì) Brullo in the Mediterranean region: adaptive traits and water use efficiency.

2016

Due to their marginal distribution, peripheral tree populations are highly vulnerable and are more likely to be influenced by extreme climate conditions. This occurrence is known to cause dieback in many species at their Mediterranean margins. Quercus gussonei (Borzì) Brullo is a deciduous oak endemic of Sicily. It is a thermophilous, peripheral form of Quercus cerris L. which is showing an incipient but ongoing decline. A deeper ecophysiological knowledge is urgently needed on this species in order to plan proper conservation actions and reduce the risk of its extinction. In the aim to understand at what extent changes in environmental conditions could be responsible for Q. gussonei declin…

STUDIES ON NAD- AND NADP- DEPENDENT ENZYMES IN PERIPHERAL NERVE

1966

Molecular and kinetic properties of lactate dehydrogenase in the degenerating peripheral nerve

1966

Abstract Electrophoretic and catalytic studies have been carried out on lactate dehydrogenase of normal and transected sciatic nerves of the rat. Lactate dehydrogenase of the intact nerve exhibits an almost even distribution of activity among its component iso-enzymes. The complete transection of the nerve is responsible for a deep and immediate shift of the enzyme towards the so-called muscle type pattern. Seven days after the nerve section the percentage activity of iso-enzyme 5 is almost three times higher than in the intact nerve. After a short lag period lactate dehydrogenase specific activity (activity/mg protein) undergoes a sharp decrease in transected nerves. The return of the elec…

Incorporation of Membrane Proteins in Solid-Supported Lipid Layers

1995

Membrane oligo- and polysialic acids

2011

AbstractPolysialic acid (polySia) and oligosialic acid (oligoSia) chains are linear polysaccharides composed of sialic acid monomers. The majority of biological poly/oligoSia chains are bound to membranes. There is a large diversity of membrane poly/oligoSia in terms of chain length, occurrence, biological function, and the mode of membrane attachment. Poly/oligoSia can be anchored to a membrane via a phospholipid (polySia in bacteria), a glycosphingolipid (oligoSia in gangliosides), an integral membrane glycoprotein, or a glycoprotein attached to a membrane via glycosylphosphatidylinositol. In eukaryotic cells, the attachment of a poly/oligoSia chain to the membrane anchor is usually throu…

Solid State NMR Structure Analysis of the Antimicrobial Peptide Gramicidin S in Lipid Membranes: Concentration-Dependent Re-alignment and Self-Assemb…

2008

Antimicrobial peptides can kill bacteria by permeabilizing their cell membrane, as these amphiphilicmolecules interact favourably with lipid bilayers. This mechanism of action is attributed eitherto the formation of a peptide “carpet” on the membrane surface, or to a transmembranepore. However, the structure of such a pore has not yet been resolved under relevant conditions.Gramicidin S is a symmetrical cyclic β-sheet decapeptide, which has been previouslyshown by solid state NMR to lie flat on the membrane surface at low peptide:lipid ratios (≤ 1:80).Using highly sensitive 19F-NMR, supported by 15N-labelling,we found that gramicidin S can flip into an upright transmembrane alignment at hig…