Search Results
Results 201 - 250 of 992
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Hershey T - - 2003
OBJECTIVE: To assess whether subthalamic nuclei (STN) stimulation's primary mechanism of action is to drive or inhibit output neurons. METHODS: Cerebral blood flow responses to STN stimulation were measured using PET in 13 patients with Parkinson disease. Patients were scanned with stimulators off and on (six scans each condition). Clinical ...
Delgado-Molina Esther - - 2003
PURPOSE: We conducted a study to determine the possible differences in blood aspiration between 2 needles of the same length and external gauge but with different internal gauges during truncal block of the inferior alveolar nerve. The working hypothesis was that increased blood aspiration may be expected with larger internal ...
Eicke Bernhard M - - 2003
OBJECTIVE: Neurophysiological assessment of the peripheral autonomic system is characterized by various limitations. An alternative approach to laser Doppler and venous plethymography is the assessment of the sympathetic vasomotor response of the radial artery obtained by continuous wave Doppler sonography. Nomogram data have been established and demonstrate the temporary disappearance ...
Koeda S - - 2003
We evoked changes in lower lip blood flow and systemic arterial blood pressure by electrically stimulating the central cut end of the lingual nerve in artificially ventilated, urethane-anesthetized, cervically vago-sympathectomized cats, rats, rabbits, and guinea pig. The systemic arterial blood pressure changes were species-dependent: increases in rat, consistent decreases in ...
Ootsuka Y - - 2003
5-HT1A receptor agonists lower body temperature. We have investigated whether activation of 5-HT1A receptors inhibits cutaneous sympathetic discharge so that dilatation of the cutaneous vascular bed lowers body temperature by increasing heat transfer to the environment. We measured ear pinna blood flow in conscious rabbits (with chronically implanted Doppler ultrasound ...
Iaconetta Giorgio - - 2003
OBJECT: The sphenopetroclival area is the border zone between the middle and posterior cranial fossa. Several authors have studied the microsurgical anatomy of this region and have furnished sometimes contradictory descriptions of this area, which still represents a great challenge for the neurosurgeon. On the basis of previous anatomical data ...
Uchida Sae - - 2003
The effects of mechanical afferent stimulation of either a hindpaw or a hind leg on ovarian blood flow and systemic arterial blood pressure were studied in anesthetized nonpregnant adult female rats. Ovarian blood flow at the left side was continuously measured using a laser Doppler flowmeter. A mechanical stimulus (by ...
Kobayashi Shigeru - - 2003
STUDY DESIGN: An intraoperative straight-leg-raising (SLR) test was conducted to investigate patients with lumbar disc herniation to observe the changes in intraradicular blood flow, which then were compared with the clinical features. OBJECTIVE: The legs of each patient were hung down from the operating table as a reverse SLR test ...
Polska Elzbieta - - 2003
PURPOSE: There is evidence from a variety of animal studies that the adenosine system plays a role in the control of intraocular pressure (IOP) and ocular blood flow. However, human data on the effect of adenosine on IOP and choroidal and optic nerve blood flow are not available. METHODS: The ...
Barin A K - - 2003
In joints, synthetic mu-opioids reduce inflammatory changes such as protein extravasation and associated oedema formation. However, the effect of endogenous opioid peptides on other inflammatory processes such as altered tissue blood flow has not been investigated. The present study examined the peripheral effects of the endogenous mu-opioid ligand endomorphin-1 (EM-1) ...
Arnold Anthony C - - 2003
Based on histopathology, electron microscopic corrosion cast studies, optic nerve blood flow studies, and clinical data, the pathogenesis of idiopathic nonarteritic ischemic optic neuropathy includes the following features: (1) structurally crowded optic discs are predisposed; (2) laminar and retrolaminar regions are the most common locations for infarction; (3) there is ...
Frangiskos F - - 2003
Aspiration of the syringe after the needle had been placed in position for an inferior alveolar nerve block (but before the anaesthetic solution was injected) in 250 patients showed that the tip of the needle was in a blood vessel in 49 (20%). Aspiration of blood was significantly more common ...
Zhang Yi - - 2003
We sought to define the contribution of the climbing fibers (CF), one of the major inputs to Purkinje neurons, to the increase in cerebellar blood flow (BFcrb) produced by activation of the cerebellar cortex. The neurotoxin 3-acetylpyridine was used to lesion the inferior olive, the site from which the CF ...
Ben Simon Guy J - - 2003
BACKGROUND AND OBJECTIVE: To examine the reliability of scanning laser Doppler flowmetry in measuring capillary flow in regions of the optic nerve head, which are manifested differently by confocal tomographic angiography. PATIENTS AND METHODS: Capillary blood flow of the optic nerve head was measured in 16 eyes of 13 patients ...
Blaber A P - - 2003
Orthostatic reflexes were examined at 375 m and after 60 min of exposure in a hypobaric chamber at 3660 m using a 20-min 70 degrees head-up tilt (HUT) test. Mean arterial blood pressure, R wave-R wave interval (RRI), and mean cerebral blood flow velocity (MFV) were examined with coarse-graining spectral ...
Kemppainen P - - 2003
Animal experiments have shown that the application of capsaicin to oral mucosa leads to a neurogenic inflammation associated with blood flow elevations in gingivomucosal tissues. In this investigation, we measured the tooth stimulation and capsaicin-evoked blood flow responses in maxillary gingiva in humans to study whether axon-reflex-mediated vasodilatation crosses the ...
Satoh-Kuriwada S - - 2003
This study was designed to determine whether painful electrical stimulation of the tooth pulp induces centrally mediated reflex vasomotor changes in human gingiva and whether the sympathetic nervous system is involved in the vasomotor responses. Dynamic changes in maxillary gingival blood flow (GBF) following painful electrical stimulation of the mandibular ...
Wang Joseph - - 2003
A flow-injection system with an organophosphorus-hydrolase (OPH)-biosensor detector has been developed and characterized for the rapid detection of organophosphorus (OP) nerve agents. The enzyme was immobilized onto a thin-film gold detector through a cystamine-glutaraldehyde coupling. Factors influencing the performance were optimized. The resulting flow system offered a fast, sensitive, selective, ...
Gallar Juana - - 2003
PURPOSE: To study the response of scleral cold receptors located in areas of the eye unexposed to temperature and blood flow changes. METHODS: In anesthetized cats, the neural activity was recorded from single, cold-sensory fibers of the ciliary nerves innervating the sclera and limbus. Controlled temperature changes of the receptive ...
Rodd Helen D - - 2003
This study sought to explore the anatomical relationships between peptidergic nerves and blood vessels within human primary and permanent teeth. Extracted primary and permanent molars (n = 120) were split longitudinally, placed in Zamboni's fixative and the coronal pulps were processed for indirect immunofluorescence. Ten-micrometre-thick serial frozen pulp sections were ...
Erdos Benedek - - 2003
It is a well-known phenomenon that cerebral blood flow is coupled to neural activation induced by non-noxious somatosensory stimulation. However, basic questions related to pain-induced cerebral blood flow changes remain unanswered. In the present study, the sciatic nerve of anesthetized rats was subjected to electric stimulation with noxious and non-noxious ...
Buerk Donald G - - 2003
We report the first dynamic measurements of tissue nitric oxide (NO) during functional activation of rat somatosensory cortex by electrical forepaw stimulation. Cortical tissue NO was measured electrochemically with rapid-responding recessed microelectrodes (tips <10 microm). Simultaneous blood flow measurements were made by laser-Doppler flowmetry (LDF). NO immediately increased, reaching a ...
Hida Shinichi - - 2003
STUDY DESIGN: Nerve root blood flow was intraoperatively measured before and after discectomy for lumbar disc herniation and compared with clinical features. OBJECTIVE: To investigate the relation between nerve root blood flow changes and symptoms associated with lumbar disc herniation. SUMMARY OF BACKGROUND DATA: Several authors have reported that recovery ...
Chamot Stéphane R - - 2003
A fundus camera-based phosphorometer to noninvasively and quasicontinuously measure the blood partial pressure of oxygen (pO(2,blood)) in the microvasculature of the pig optic nerve using the principle of the phosphorescence quenching by O(2) is described. A porphyrin dye is injected into the venous circulation and the decay of its phosphorescence ...
Dezawa Akira - - 2002
STUDY DESIGN: Assessment of qualitative and quantitative changes in the microcirculation of nerve roots, such as the diameter of blood vessels and the low rate of erythrocytes, was observed during lumbar interbody fusion. OBJECTIVE: To ascertain changes in the microcirculation of nerve roots before and after retraction during lumbar interbody ...
Tubbs R Shane - - 2002
OBJECTIVE: Cadaveric studies of the blood supply to the human cervical sympathetic chain and ganglia are lacking in the English literature. This study seeks to elucidate the gross blood supply of the cervical sympathetic chain so as to avoid surgical disruption of these vessels and thus decrease the risk of ...
Izumi Hiroshi - - 2002
We measured the changes in lower lip blood flow and systemic arterial blood pressure evoked by lingual nerve or trigeminal spinal nucleus (Vsp) stimulation to gain an insight into the brainstem integration of sympathetic and parasympathetic responses to nociceptive stimulation. We used artificially ventilated, cervically vago-sympathectomized cats deeply anesthetized with ...
Zubairy A I - - 2002
All invasive procedures carry some degree of risk of damage to the normal structures in the proximity of the region where the procedure is performed. The risk is, however, minimal for venous cannulation. A case is reported of an injury to the anterior interosseus nerve sustained during venepunture for routine ...
Palmer Greta M - - 2002
It has been proposed that epinephrine prolongs lidocaine nerve blockade duration by exerting a local vasoconstrictive effect on tissues at the injection site, slowing lidocaine's local clearance. However, previous studies have failed to demonstrate consistent effects of lidocaine and epinephrine, injected alone and in combination, on vascular tone or regional ...
Buerk Donald G - - 2002
Blood flow studies in the brain, heart, and other organs suggest that there could be interaction between nitric oxide (NO) and adenosine. This possibility was investigated in the optic nerve head (ONH) during photic stimulation of the dark-adapted cat eye. Functional activation of ONH blood flow was measured by laser ...
Xu Qing-Gui - - 2002
Neuromas are generally considered to be swollen uniform collections of uncontrolled aberrantly sprouting axons. In early experimental neuromas, there are substantial rises in local blood flow associated with their formation, but human studies of chronic lesions have suggested that neuromas develop ischemia and become impediments to regeneration. The issue is ...
Sundin Lena - - 2002
Inspection of the dorsal end of fish gills reveals an impressive set of nerve trunks, connecting the gills to the brain. These trunks are branches of cranial nerves VII (the facial) and especially IX (the glossopharyngeal) and X (the vagus). The nerve trunks carry a variety of nervous pathways to ...
Sekiguchi Miho - - 2002
STUDY DESIGN: An analysis of nerve vascular changes in nerve roots induced by serotonin in chronically compressed nerve roots. OBJECTIVES: To assess the hypotheses that serotonin might have a vasoconstrictive effect in chronically compressed nerve roots. SUMMARY OF BACKGROUND DATA: The 5-hydroxytryptamine 2A receptor is involved in serotonin-induced activation or ...
Andrew D - - 2002
Single nerve fibres innervating tooth pulp were isolated from filaments dissected from the inferior alveolar nerve in 17 anaesthetized cats. The fibres were studied to determine whether electrical stimulation of single units produced detectable changes in pulpal blood flow. Single pulpal nerve fibres were electrically stimulated at just above their ...
Vanderthommen Marc - - 2002
OBJECTIVES: To evaluate, with a high spatial resolution, the blood flow variations in human skeletal muscle during neuromuscular electric stimulation (NMES) and hence to gain better understanding of the mechanisms of muscle spatial recruitment during NMES. DESIGN: One thigh was submitted to 3 stimulation bouts of different durations (S1=4min, S2=8min, ...
Lagi Alfonso - - 2002
Continuous recording of mean cerebral blood flow velocity (MCBFV) by Doppler ultrasound allows detection of low-frequency (LF) oscillations, which reflect sympathetic activity in the cerebral circulation. To establish whether the sympathetic drive to the cerebral circulation is altered in patients with compensated cirrhosis, and, if so, where alterations take place, ...
Melrose James - - 2002
STUDY DESIGN: Nerves and blood vessel distribution in discs were localized immunohistochemically and correlated with the proteoglycan contents of normal and degenerate disc tissues. OBJECTIVE: The aim of the present study was to systematically evaluate whether nerve and blood vessel ingrowth was associated with depletion of disc proteoglycans and degenerative ...
Yamaguchi Shinjiro - - 2002
The effects of electrical stimulation of the dorsal skin area on the mesenteric arterioles were investigated in anesthetized rats by the use of an intravital microscope-television system. Changes in the diameter of the mesenteric precapillary arterioles (10-40 microm in diameter) were measured with an image processor. Blood flow velocity in ...
Janssen Ben J A - - 2002
Control of blood pressure and of blood flow is essential for maintenance of homeostasis. The hemodynamic state is adjusted by intrinsic, neural, and hormonal mechanisms to optimize adaptation to internal and environmental challenges. In the last decade, many studies showed that modification of the mouse genome may alter the capacity ...
Gazelius B - - 2002
BACKGROUND: During endoscopic transthoracic sympathicotomy (ETS) in patients with hyperhidrosis it is useful to assess the effect of surgery peroperatively. However, the autonomic system is affected in various ways by different anesthetic agents. In the present study, the effect of ETS during either isoflurane or propofol anesthesia was evaluated by ...
Perlmutter J S - - 2002
BACKGROUND AND OBJECTIVE: Deep brain stimulation (DBS) of the ventral intermediate nucleus of the thalamus (VIM) provides remarkable relief of tremor in the limbs contralateral to the side of the brain stimulated. The benefits have been sufficiently dramatic that this is now an accepted clinical treatment of essential as well ...
Kihara Mikihiro - - 2002
OBJECTIVE: Aging impacts microvessels in a number of tissue beds. Vasopressin acts as a vasoconstrictor in most blood vessels but may also cause vasodilation. We evaluated the role of aging and vasopressin in the regulation of nerve blood flow (NBF) in rat peripheral nerve. METHODS: We undertook a dose-response study ...
Hofman S - - 2002
Pulpal blood flow (PBF) changes have been monitored by laser Doppler flowmetry on rat mandibular incisors. Electrical stimulation (10 sec, 50 microA, 2 ms, 20 Hz) of one incisor induced a blood flow decrease followed by a blood flow increase. The effect of intravenous administration of antagonists of ionotropic glutamate ...
Chamot Stéphane R - - 2002
BACKGROUND: To investigate the effect of isovolumic hemodilution on the tissue oxygenation of the optic nerve head (ONH). MATERIAL AND METHODS: In 9 miniature pigs (6 - 12 kg), hemodilution was performed by replacing 100 - 140 ml of blood by an equivalent volume of 6 % hydroxyethyl starch in ...
Mann W J - - 2002
Surgical treatment of lesions of the skull base carries significant risk to the functioning of the cerebral hemispheres, the brain stem and the cranial nerves. This risk is due both, to problems associated with maintaining an adequate blood flow while exposing and removing the tumor and to direct or indirect ...
Koss Michael C - - 2002
A new technique using ultrasonic flowmetry was developed in order to directly measure blood flow in the long posterior ciliary artery (LPCA) of anesthetized cats. Basal LPCA blood flow averaged about 0.6 ml/min and was stable over the experimental period. Electrical stimulation of the cervical preganglionic cervical sympathetic nerve produced ...
Talman William T - - 2002
Autoregulation maintains cerebral blood flow near basal levels as blood pressure increases, but vasodilation, breakthrough, occurs when hypertension exceeds the autoregulatory range. Loss of breakthrough after transection of baroreceptor nerves suggests that breakthrough is neurally mediated. We hypothesize that central baroreflex interruption will likewise prevent breakthrough. In treated rats, injections ...
Shishido Hiroaki - - 2002
STUDY DESIGN: An experimental physiologic and histologic study of dexamethasone effects on peripheral nerves. OBJECTIVE: To characterize the effect of topically applied 0.4% dexamethasone on acute changes in nerve blood flow and subsequent histologic changes in rat sciatic nerve fibers. SUMMARY OF BACKGROUND DATA: Dexamethasone is an anti-inflammatory glucocorticoid used ...
Aggarwal Anuradha - - 2002
BACKGROUND: Although it is established that heightened sympathetic drive exists in congestive heart failure (CHF), the reflex processes by which this may occur and the sites in the central nervous system that may be responsible for mediating this process are not yet fully elucidated. METHODS AND RESULTS: Eight patients with ...
Ngai Al C - - 2002
Pial arterioles supplying the hindlimb somatosensory cortex dilate in response to contralateral sciatic nerve stimulation. The mechanism of this pial vasodilation is not well understood. One possibility is that vasoactive metabolites released during brain activation may diffuse to subarachnoid cerebrospinal fluid (CSF) to dilate pial vessels. To test this hypothesis, ...
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