Search results for "nerve"
showing 10 items of 1683 documents
Nitric oxide-mediated beta 2-adrenoceptor relaxation is impaired in mesenteric veins from portal-hypertensive rats.
1996
Abstract BACKGROUND & AIMS: beta-Adrenergic relaxation seems to be mediated by nitric oxide. The aim of this study was to evaluate changes induced by portal hypertension in beta 2-adrenergic vasorelaxation. METHODS: Isolated rat mesenteric veins were relaxed by salbutamol, and nerve- mediated vasocontractions were induced by electrical field stimulation. Responses were evaluated in the presence of NG-nitro-L-arginine methyl ester (L-NAME) or tetrodotoxin. Immunocytochemical techniques were used for localization of neuronal NO synthase. RESULTS: Salbutamol-induced relaxations were decreased in rings from portal-hypertensive animals. L- NAME reduced these relaxations, but its effects were mor…
Subretinal neovascularization in anterior ischemic optic neuropathy.
1991
A 66-year-old man with typical anterior ischemic optic neuropathy in one eye suffered from edema of the optic disc without functional changes in the fellow eye. However, 7 months later, a reduction in visual acuity, a change in the visual field and a worsening of the contrast-sensitivity curve demonstrated the development of typical anterior ischemic optic neuropathy in this eye as well. After another 6-month period, in addition to these changes, an extensive subretinal neovascular membrane developed in the papillomacular area, which further reduced the patient's visual acuity and required treatment with laser photocoagulation. To our knowledge, this is the first case report of the occurren…
A presynaptic excitatory M1 muscarine receptor at postganglionic cardiac noradrenergic nerve fibres that is activated by endogenous acetylcholine.
1990
Rabbit atria were isolated with the extrinsic right vagus and sympathetic nerves intact and perfused with Tyrode solution. Noradrenaline overflow evoked by sympathetic nerve stimulation (SNS) at 3 Hz for 3 min was determined before, during, and after vagus nerve stimulation (VNS), also at 3 Hz and for 3 min. The VNS pulses preceded the SNS pulses by 3, 100 and 233 ms. Acetylcholine overflow was determined after labelling of the transmitter stores with [14C]choline. Pirenzepine 80 nmol/l failed to alter the muscarinic inhibition of noradrenaline overflow when the vago-sympathetic impulse intervals were 3 and 233 ms. At an interval of 100 ms VNS did not significantly inhibit noradrenaline ove…
Retinal nerve fibre layer and brain grey substance as early prognostic factors for disability in multiple sclerosis.
2012
We read with interest the article by Bock et al ,1 in which the association between retinal nerve fibre layer (RNFL) and total macular volume (TMV) was analysed by optical coherence tomography (OCT) and contrast sensitivity was measured by functional acuity contrast testing in relapsing-remitting multiple sclerosis (MS) patients. The authors found that the functional contrast vision in MS is influenced by morphological changes in the anterior visual pathway. This work emphasised that contrast sensitivity is reduced in MS, and that RNFL and TMV, as morphological measures of retinal axon loss, are predictors of contrast sensitivity. Ophthalmological examinations were the basis of the Bock et …
Predictive value of heidelberg retina tomograph parameters for the development of glaucoma in the European glaucoma prevention study
2015
Purpose To determine whether baseline Heidelberg Retina Tomograph (HRT) measurements of the optic disc are associated with the development of open-angle glaucoma (OAG) in individuals with ocular hypertension in the European Glaucoma Prevention Study (EGPS). Design Retrospective analysis of a prospective, randomized, multicenter, double-masked, controlled clinical trial. Methods There were 489 participants in the HRT Ancillary Study to the EGPS. Each baseline HRT parameter was assessed in univariate and multivariate proportional hazards models to determine its association with the development of OAG. Proportional hazards models were used to identify HRT variables that predicted which partici…
Biased postural vertical in humans with hemispheric cerebral lesions.
1998
International audience; This study was aimed at demonstrating the existence of a biased postural vertical in humans with a recent cerebral lesion. The postural vertical of patients and controls was analysed comparatively using a self-regulated balancing task, performed in sitting posture. Patients displayed a quite constant (19/22) contralesional tilt of the postural vertical (mean -2.6 degrees), varying with the severity of their spatial neglect and hemianaethesia. Eight of them showed a pathological contralesional bias (mean -5.5 degrees) as compared to normals. This result indicates an asymmetric process of somatic graviceptive information due to some cerebral lesions. When patients were…
Postoperative analgesic efficacy of peripheral levobupivacaine and ropivacaine: a prospective, randomized double-blind trial in patients after total …
2008
BACKGROUND: Several previous trials have characterized the intra- and postoperative effects of the recently introduced local anesthetics, levobupivacaine and ropivacaine, for a variety of continuous peripheral nerve blocks. METHODS: We compared the analgesic efficacy of levobupivacaine 0.125% versus ropivacaine 0.2% via patient-controlled femoral nerve analgesia after total knee arthroplasty. In a double-blind, randomized, prospective design, 60 patients received femoral infusion with either substance. We analyzed postoperative local anesthetic consumption, pain scores, motor block, and opioid requirements over 72 h. RESULTS: Pain scores, motor block incidence, and opioid requirements were …
Functional evidence for different roles of GABAA and GABAB receptors in modulating mouse gastric tone
2010
Abstract The aims of the present study were to investigate, using mouse whole stomach in vitro , the effects of γ-aminobutyric acid (GABA) and GABA receptor agonists on the spontaneous gastric tone, to examine the subtypes of GABA receptors involved in the responses and to determine the possible site(s) of action. GABA induced gastric relaxation, which was antagonized by the GABA A -receptor antagonist, bicuculline, potentiated by phaclofen, GABA B -receptor antagonist, but not affected by 1,2,5,6-Tetrahydropyridin-4-yl methylphosphinic acid hydrate (TPMPA), GABA C -receptor antagonist. Muscimol, GABA A -receptor agonist, mimicked GABA effects inducing relaxation, which was significantly re…
Impact of regional femoral nerve block during general anesthesia for hip arthoplasty on blood pressure, heart rate and pain control: A randomized con…
2015
Background Adequate pain management is essential for preventing hemodynamic instability which can affect the perfusion of vital organs during the perioperative period, particularly in geriatric patients. For hip arthroplasty, peripheral nerve block is frequently used, limiting the adverse effects of opioid and non-opioid analgesics. Objective The aim was to survey the impact of a supplementary single shot femoral nerve block (FNB) on hemodynamic stability and pain level. Methods After registration at German Clinical Trial Register (DRKS-ID): DRKS00000752. and Ethics Committee approval (University Hospital of Marburg), 80 patients who underwent elective hip surgery were included. Half of the…
Evolution of otosclerosis to cochlear implantation.
2011
Abstract Introduction Otosclerosis is an osteodystrophy of the labyrinthine capsule producing conductive hearing loss. If the process invades the cochlea, a sensorineural hearing loss usually takes place. The cochlear implant is a good alternative in these patients. Objective To ascertain the behaviour of cochlear implantation (CI) in otosclerosis. Material and methods We reviewed a database of 250 patients who underwent CI, performing a retrospective study of 13 patients with clinical, audiological and/or imaging findings of bilateral otosclerosis. The 26 ears were studied as to their natural history, previous surgeries, evolution to profound hearing loss, computed tomography (CT) images, …