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Lateral Wall (lateral + wall)

Distribution by Scientific Domains

Medical Sciences	64%
Life Sciences	32%

Distribution within Medical Sciences

Cardiovascular Disease	34%
Otolaryngology (Ear, Nose & Throat)	29%

Selected Abstracts

Is the Left Ventricular Lateral Wall the Best Lead Implantation Site for Cardiac Resynchronization Therapy?

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1p2 2003
MAURIZIO GASPARINI
GASPARINI, M., et al.: Is the Left Ventricular Lateral Wall the Best Lead Implantation Site for Cardiac Resynchronization Therapy?Short-term hemodynamic studies consistently report greater effects of cardiac resynchronization therapy (CRT) in patients stimulated from a LV lateral coronary sinus tributary (CST) compared to a septal site. The aim of the study was to compare the long-term efficacy of CRT when performed from different LV stimulation sites. From October 1999 to April 2002, 158 patients (mean age 65 years, mean LVEF 0.29, mean QRS width 174 ms) underwent successful CRT, from the anterior (A) CST in 21 patients, the anterolateral (AL) CST in 37 patients, the lateral (L) CST in 57 patients, the posterolateral (PL) CST in 40 patients, and the middle cardiac vein (MCV) CST in 3 patients. NYHA functional class, 6-minute walk test, and echocardiographic measurements were examined at baseline, and at 3, 6, and 12 months. Comparisons were made among all pacing sites or between lateral and septal sites by grouping AL + L + PL CST as lateral site (134 patients, 85%) and A + MC CST as septal site (24 patients, 15%). In patients stimulated from lateral sites, LVEF increased from 0.30 to 0.39(P < 0.0001), 6-minute walk test from 323 to 458 m(P < 0.0001), and the proportion of NYHA Class III,IV patients decreased from 82% to 10%(P < 0.0001). In patients stimulated from septal sites, LVEF increased from 0.28 to 0.41(P < 0.0001), 6-minute walk test from 314 to 494 m(P < 0.0001), and the proportion of NYHA Class III,IV patients decreased from 75% to 23%(P < 0.0001). A significant improvement in cardiac function and increase in exercise capacity were observed over time regardless of the LV stimulation sites, either considered singly or grouped as lateral versus septal sites. (PACE 2003; 26[Pt. II]:162,168) [source]

Chronologic Changes of Nitric Oxide Concentration in the Cochlear Lateral Wall and Its Role in Noise-Induced Permanent Threshold Shift

THE LARYNGOSCOPE, Issue 5 2008
Yuh-Shyang Chen MD
Abstract Objective: The objective of this study was to investigate the chronologic changes of nitric oxide (NO) concentration in the cochlear lateral wall and to explore its possible role in permanent threshold shift (PTS) after intense noise exposure. Materials and Methods: Seventeen guinea pigs were subjected to a single continuous exposure to broadband white noise at 105 ± 2 dB sound pressure level (SPL) for 40 hours and were divided into four groups according to various postnoise recovery periods. Another 12 guinea pigs were not exposed to noise and served as controls. The hearing status of all animals was evaluated with auditory brainstem responses (ABR) evoked by condensation "click" sounds. ABR were recorded both prior to noise exposure and immediately before killing the animal. After death, NO concentration in the cochlear lateral wall was directly measured with an NO/ozone chemiluminescence technique. Results: An approximately 1.7-fold increase in NO concentration was observed immediately postnoise exposure, which persisted for up to 28 days. The threshold of ABR elevation (mean, 30 dB SPL) peaked immediately after cessation of noise exposure and gradually resolved to a PTS (mean, 14.5 dB SPL) 56 days after noise exposure when NO concentration had returned to its prenoise exposure level. Conclusion: Noise-induced threshold shift, which resolved to a mild PTS, can be partially attributed to NO elevation in the cochlear lateral wall. Our results revealed a nonlinear correlation between ABR recovery and depletion of NO, indicating that the mechanisms of NO changes in the cochlear lateral wall may be more complicated than previously conceived and that other pathophysiologic mechanisms may also play important roles in noise-induced PTS. [source]

Acinetobacter Endocarditis Presenting as a Large Right Atrial Mass: An Atypical Presentation

ECHOCARDIOGRAPHY, Issue 4 2010
Sherrita Bhagan-Bruno M.D.
This paper discusses a 26-year-old woman with end-stage renal disease on hemodialysis and Acinetobacter calcoaceticus-baumannii complex endocarditis. The patient had an indwelling right internal jugular catheter that was probably the nidus of infection. Transthoracic echocardiogram revealed an atypical presentation of the endocarditis as a large intracardiac mass, measuring in centimeters and occupying more than 50% of the right atrial cavity. The mass was attached to the lateral wall of the right atrium without valvular involvement. The patient was treated with prompt removal of the indwelling catheter, intravenous antibiotics, and surgical resection of the mass with an uneventful recovery. A literature search for cases of "Acinetobacter endocarditis" reveals this as the first case reported of Acinetobacter endocarditis presenting in this manner. (Echocardiography 2010;27:E39-E42) [source]

Left Ventricular Function in Male Patients with Secondary Hypogonadism

ECHOCARDIOGRAPHY, Issue 3 2007
Oben Baysan M.D.
Background: In addition to the effects on ventricular repolarization, testosterone could also affect left ventricular performance. The enhancement of left ventricular contractility in testosterone-deficient rats following testosterone replacement implies to the possible testosterone effect. Objectives: The aim of the current study is to reveal the alterations of left ventricular functions, if any, in secondary hypogonadal male patients. Methods: Thirty-four males with secondary hypogonadism comprised the study group. The control group consisted of 30 healthy subjects. Echocardiographic measurements including left ventricular dimensions, ejection fraction, mitral inflow, and left ventricular outflow parameters were obtained from all subjects. Tissue Doppler parameters were also measured from left ventricular lateral wall and interventricular septum. Results: Left ventricular diameters, wall thicknesses, and performance parameters were similar in both groups. Mitral inflow parameters showed a statistically insignificant difference. Pulse-wave tissue Doppler interpretation of hypogonadal and healthy subjects were similar in terms of lateral and septal basal segment Sm, Em, and Am wave velocities. Conclusions: Regarding the findings of previous studies that showed impaired myocardial contractility and lusitropy in testosterone deficient rats and our study results, further studies are needed for better understanding of testosterone's effects on human myocardium. [source]

Apical surgery of a maxillary molar creating a maxillary sinus window using ultrasonics: a clinical case

INTERNATIONAL ENDODONTIC JOURNAL, Issue 11 2010
B. García
García B, Peñarrocha M, Peñarrocha MA, von Arx T. Apical surgery of a maxillary molar creating a maxillary sinus window using ultrasonics: a clinical case. International Endodontic Journal, 43, 1054,1061, 2010. Abstract Aim, To describe a method of carrying out apical surgery of a maxillary molar using ultrasonics to create a lateral sinus window into the maxillary sinus and an endoscope to enhance visibility during surgery. Summary, A 37-year-old female patient presented with tenderness to percussion of the maxillary second right molar. Root canal treatment had been undertaken, and the tooth restored with a metal-ceramic crown. Radiological examination revealed an apical radiolucency in close proximity to the maxillary sinus. Apical surgery of the molar was performed through the maxillary sinus, using ultrasonics for the osteotomy, creating a window in the lateral wall of the maxillary sinus. During surgery, the lining of the sinus was exposed and elevated without perforation. The root-end was resected using a round tungsten carbide drill, and the root-end cavity was prepared with ultrasonic retrotips. Root-end filling was accomplished with MTA®. An endoscope was used to examine the cut root face, the prepared cavity and the root-end filling. No intraoperative or postoperative complications were observed. At the 12-month follow-up, the tooth had no clinical signs or symptoms, and the radiograph demonstrated progressing resolution of the radiolucency. Key learning points ,,When conventional root canal retreatment cannot be performed or has failed, apical surgery may be considered, even in maxillary molars with roots in close proximity to the maxillary sinus. ,,Ultrasonic sinus window preparation allows more control and can minimize perforation of the sinus membrane when compared with conventional rotary drilling techniques. ,,The endoscope enhances visibility during endodontic surgery, thus improving the quality of the case. [source]

A comparative histological evaluation of the biocompatibility of materials used in apical surgery

INTERNATIONAL ENDODONTIC JOURNAL, Issue 11 2004
C. J. A. Sousa
Abstract Aim, To evaluate the biological properties of a variety of materials that could be used in apical surgery. Methodology, The intraosseous implant technique recommended by the FDI (1980) and ADA (1982) was used to test the following materials: zinc oxide-eugenol (ZOE), mineral trioxide aggregate (MTA), and Z-100 light-cured composite resin. Thirty guinea-pigs, 10 for each material, divided into experimental periods of 4 and 12 weeks, received one implant on each side of the lower jaw symphysis. The connective tissue response alongside the lateral wall outside the cup served as a negative control for the technique. At the end of the observation periods, the animals were killed and the specimens prepared for routine histological examination to evaluate their biocompatibility. Results, The reaction of the tissue to the materials diminished with time. The ZOE cement was highly toxic during the 4-week experimental period, but this profile changed significantly after 12 weeks, when it showed biocompatible characteristics. MTA and Z-100 showed biocompatibility in this test model at both time periods. Conclusions, MTA and Z-100 composite were biocompatible at 4 and 12 weeks in this experimental model. [source]

Heterogeneous Regional Endocardial Repolarization is Associated with Increased Risk for Ischemia-Dependent Ventricular Fibrillation after Myocardial Infarction

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2003
Michael H. Swann M.SC.
Introduction: The aim of this study was to investigate whether the characteristics of endocardial ventricular repolarization are associated with differential risk for sudden death. Prolonged surface QT interval is associated with increased arrhythmic risk after myocardial infarction (MI), but the underlying mechanism of QT prolongation and its relation to lethal arrhythmias are unclear. Methods and Results: Ventricular fibrillation (VF) risk was assessed in 12 dogs 1 month after anterior MI during an exercise test coupled with brief circumflex coronary occlusion. Susceptible dogs (n = 5) developed VF during the brief ischemic episode, whereas resistant dogs did not (n = 7). Surface QT interval was measured at rest. Endocardial electroanatomic catheter maps of left ventricular repolarization were obtained in four unique regions identified by echocardiography and compared between groups. Compared to resistant dogs, susceptible dogs were characterized by prolonged surface QT intervals (240 ± 10 msec vs 222 ± 7 msec, P = 0.04). In addition, they had lower baroreflex sensitivity (9.7 ± 1.5 msec/mmHg vs 28 ± 9.8 msec/mmHg, P < 0.01) and a tachycardic response to acute ischemia suggesting higher propensity for stronger sympathetic reflexes. Surface QT interval prolongation in susceptible dogs was due to a marked heterogeneity of endocardial left ventricular repolarization (239 ± 42 msec, basal anterior wall vs 197 ± 35, lateral wall; P < 0.001). Resistant animals had no regional differences in endocardial repolarization. Conclusion: Sympathetic activation following MI not only produces adverse structural remodeling but also contributes to adverse electrophysiologic remodeling resulting in heterogeneous ventricular repolarization and in a myocardial substrate conducive to lethal reentrant arrhythmias. (J Cardiovasc Electrophysiol, Vol. 14, pp. 873-879, August 2003) [source]

Acoustic videodensitometric parameters correlate with abnormalities of left ventricular filling in hypertensive patients assessed via doppler tissue imaging

JOURNAL OF CLINICAL ULTRASOUND, Issue 8 2007
Paul Coulon
Abstract Purpose Using a videodensitometric technique developed in our center we investigated whether the amplitude of variation of gray levels in the interventricular septum was related to functional parameters, especially ventricular filling as studied by doppler tissue imaging (DTI) in hypertensive patients. Methods and Results We included 35 hypertensive patients from whom we recorded a two dimensional sequence of the left ventricle from the short axis parasternal view and a doppler tissue scan of the mitral ring. Two-dimensional sections were then analyzed with Iodp software to measure variations in levels of gray in the septum. We observed significant correlations between these variations and the velocity of the Ea wave on DTI of the lateral wall (r = 0.49, p < 0.002). On dividing this population into three sub-groups according to the Appleton classification of ventricular filling, we noted a tendency to a reduction in amplitude of variations of gray of the septum in cases with abnormalities of relaxation. This was even more marked in cases with a restrictive or pseudo-normal profile. Conclusion These observations point to the interest of sonographic videodensitometry in the evaluation of hypertensive cardiopathy. Further studies will be required to determine whether it can define the extent of the abnormalities of myocardial structure and the degree of fibrosis. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007 [source]

Comparative morphology of the foot structure of four genera of Loxosomatidae (Entoprocta): Implications for foot functions and taxonomy

JOURNAL OF MORPHOLOGY, Issue 10 2010
Tohru Iseto
Abstract Entoprocta is a group of mostly cryptic, benthic invertebrates with a sedentary lifestyle. Here, we investigate the morphology of the entoproct foot, which is an important structure in attachment and locomotion. We describe the foot structure of four solitary entoprocts, Loxosoma monilis, Loxosomella stomatophora, Loxocorone allax, and Loxomitra mizugamaensis, by means of light and transmission electron microscopy. Gland cells containing secretory granules were found in the foot of all the four species. In L. monilis, the gland cells densely paved the underside of the disc-shaped foot, but no duct or groove was found. In L. stomatophora and L. allax, a foot gland was present at the frontal end of a foot groove. The foot gland was a solid cell mass in the former species but a sac-like structure in the latter. Two types of groove accessory cells were recognized in both species; groove bulge cells (GBCs) showed large cytoplasmic bulges extending into the groove lumen, while groove microvillus cells have microvillus mats in the lateral wall of the groove. The bulges of GBCs in L. stomatophora are slender and attached to one another with desmosomes, forming appendages that extend down to the substratum, hinting at their contribution to attachment and locomotion. The bulges in L. allax form large swellings that fill the groove lumen and are connected to the surrounding cells with hemidesmosomes. In the liberated buds of L. mizugamaensis, tripartite gland cell masses were found at the basal end of the stalk, but no groove was found. A small invagination, which may be the opening of the gland, was found at the center of the foot tip, where the liberated buds attach themselves to the substratum and then metamorphose into adults. No openings were found at the lateral terminal wings, which support locomotion in Loxomitra species. J. Morphol. 271:1185,1196, 2010. © 2010 Wiley-Liss, Inc. [source]

Development of the swimbladder and its innervation in the zebrafish, Danio rerio

JOURNAL OF MORPHOLOGY, Issue 11 2007
G.N. Robertson
Abstract Many teleosts including zebrafish, Danio rerio, actively regulate buoyancy with a gas-filled swimbladder, the volume of which is controlled by autonomic reflexes acting on vascular, muscular, and secretory effectors. In this study, we investigated the morphological development of the zebrafish swimbladder together with its effectors and innervation. The swimbladder first formed as a single chamber, which inflated at 1,3 days posthatching (dph), 3.5,4 mm body length. Lateral nerves were already present as demonstrated by the antibody zn-12, and blood vessels had formed in parallel on the cranial aspect to supply blood to anastomotic capillary loops as demonstrated by Tie-2 antibody staining. Neuropeptide Y-(NPY-) like immunoreactive (LIR) fibers appeared early in the single-chambered stage, and vasoactive intestinal polypeptide (VIP)-LIR fibers and cell bodies developed by 10 dph (5 mm). By 18 dph (6 mm), the anterior chamber formed by evagination from the cranial end of the original chamber; both chambers then enlarged with the ductus communicans forming a constriction between them. The parallel blood vessels developed into an arteriovenous rete on the cranial aspect of the posterior chamber and this region was innervated by zn-12-reactive fibers. Tyrosine hydroxylase- (TH-), NPY-, and VIP-LIR fibers also innervated this area and the lateral posterior chamber. Innervation of the early anterior chamber was also demonstrated by VIP-LIR fibers. By 25,30 dph (8,9 mm), a band of smooth muscle formed in the lateral wall of the posterior chamber. Although gas in the swimbladder increased buoyancy of young larvae just after first inflation, our results suggest that active control of the swimbladder may not occur until after the formation of the two chambers and subsequent development and maturation of vasculature, musculature and innervation of these structures at about 28,30 dph. J. Morphol., 2007. © 2007 Wiley-Liss, Inc. [source]

Nerve regeneration through a healthy peripheral nerve trunk as a nerve conduit: A preliminary study of a new concept in peripheral nerve surgery

MICROSURGERY, Issue 4 2002
Fuat Yüksel M.D.
The popularity of nerve conduits has increased recently due to the need for alternative nerve reconstruction techniques, obviating the harvest of nerve grafts. Based on ideas suggesting nerve tissue itself, which was the most physiologic environment for nerve regeneration, a study using 40 sciatic nerves of 20 rats was performed. The proximal stumps of transected peroneal nerves were sutured to the lateral wall of healthy tibial nerve trunks after removal of the epineurium. Twelve weeks later, tissue samples were taken from the anastomosis sites and from the levels above and below these sites. Configurations of fascicles were evaluated, and numbers of fibers were estimated. It was observed that the fibers of peroneal nerves regenerated into and through the tibial nerve trunk distally. This suggested that active regenerating fibers of a proximal stump of a nerve could regenerate and progress as a fascicular unit in optimum condition at the trunk of another healthy nerve. This preliminary study should stimulate further studies based on this new concept: that a nerve trunk can serve as the host for the regenerating fibers of another nerve. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:138,143 2002 [source]

Several distinct localization patterns for penicillin-binding proteins in Bacillus subtilis

MOLECULAR MICROBIOLOGY, Issue 3 2004
Dirk-Jan Scheffers
Summary Bacterial cell shape is determined by a rigid external cell wall. In most non-coccoid bacteria, this shape is also determined by an internal cytoskeleton formed by the actin homologues MreB and/or Mbl. To gain further insights into the topological control of cell wall synthesis in bacteria, we have constructed green fluorescent protein (GFP) fusions to all 11 penicillin-binding proteins (PBPs) expressed during vegetative growth of Bacillus subtilis. The localization of these fusions was studied in a wild-type background as well as in strains deficient in FtsZ, MreB or Mbl. PBP3 and PBP4a localized specifically to the lateral wall, in distinct foci, whereas PBP1 and PBP2b localized specifically to the septum. All other PBPs localized to both the septum and the lateral cell wall, sometimes with irregular distribution along the lateral wall or a preference for the septum. This suggests that cell wall synthesis is not dispersed but occurs at specific places along the lateral cell wall. The results implicate PBP3, PBP5 and PBP4a, and possibly PBP4, in lateral wall growth. Localization of PBPs to the septum was found to be dependent on FtsZ, but the GFP,PBP fluorescence patterns were not detectably altered in the absence of MreB or Mbl. [source]

Feasibility Of Temporary Biventricular Pacing In Patients With Reduced Left Ventricular Function After Coronary Artery Bypass Grafting

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2007
FRANK EBERHARDT M.D.
Background and Methods: Biventricular pacing improves hemodynamics after weaning from cardiopulmonary bypass in patients with severely reduced left ventricular (LV) function undergoing coronary artery bypass grafting (CABG). We examined the feasibility of temporary biventricular pacing for 96 hours postoperatively. Unipolar epicardial wires were placed on the roof of the right atrium (RA), the right ventricular (RV) outflow tract, and the LV free lateral wall and connected to an external pacing device in 51 patients (mean LV ejection fraction 35 ± 4%). Pacing and sensing thresholds, lead survival and incidence of pacemaker dysfunction were determined. Results: Atrial and RV pacing thresholds increased significantly by the 4th postoperative day, from 1.6 ± 0.2 to 2.5 ± 0.3 V at 0.5 ms (P = 0.03) at the RA, 1.4 ± 0.3 V to 2.7 ± 0.4 mV (P = 0.01) at the RV, and 1.9 ± 0.6 V to 2.9 ± 0.7 mV (P = 0.3) at the LV, while sensing thresholds decreased from 2.0 ± 0.2 to 1.7 ± 0.2 mV (P = 0.18) at the RA, 7.2 ± 0.8 to 5.1 ± 0.7 mV (P = 0.05) at the RV, and 9.4 ± 1.3 to 5.5 ± 1.1 mV (P = 0.02) at the LV. The cumulative overall incidence of lead failure was 24% by the 4th postoperative day, and was similar at the RV and LV. We observed no ventricular proarrhythmia due to pacing or temporary pacemaker malfunction. Conclusions: Biventricular pacing after CABG using a standard external pacing system was feasible and safe. [source]

Scaling of the first ethmoturbinal in nocturnal strepsirrhines: Olfactory and respiratory surfaces

THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 3 2007
Timothy D. Smith
Abstract Turbinals (scroll bones, turbinates) are projections from the lateral wall of the nasal fossa. These bones vary from simple folds to branching scrolls. Conventionally, maxilloturbinals comprise the respiratory turbinals, whereas nasoturbinals and ethmoturbinals comprise olfactory turbinals, denoting the primary type of mucosa that lines these conchae. However, the first ethmoturbinal (ETI) appears exceptional in the variability of it mucosal covering. Recently, it was suggested that the distribution of respiratory versus olfactory mucosae varies based on body size or age in strepsirrhine primates (lemurs and lorises). The present study was undertaken to determine how the rostrocaudal distribution of olfactory epithelium (OE) versus non-OE scales relative to palatal length in strepsirrhines. Serially sectioned heads of 20 strepsirrhines (10 neonates, 10 adults) were examined for presence of OE on ETI, rostral to its attachment to the nasal fossa wall (lateral root). Based on known distances between sections of ETI, the rostrocaudal length of OE was measured and compared to the length lined solely by non-OE (primarily respiratory epithelium). In 13 specimens, the total surface area of OE versus non-OE was calculated. Results show that the length of non-OE scales nearly isometrically with cranial length, while OE is more negatively allometric. In surface area, a lesser percentage of non-OE exists in smaller species than larger species and between neonates and adults. Such results are consistent with recent suggestions that the olfactory structures do not scale closely with body size, whereas respiratory structures (e.g., maxilloturbinals) may scale close to isometry. In primates and perhaps other mammals, variation in ETI morphology may reflect dual adaptations for olfaction and endothermy. Anat Rec, 2007. © 2007 Wiley-Liss, Inc. [source]

Selective neck dissection and deintensified postoperative radiation and chemotherapy for oropharyngeal cancer: A subset analysis of the university of pennsylvania transoral robotic surgery trial,

THE LARYNGOSCOPE, Issue 9 2010
Gregory S. Weinstein MD
Abstract Objectives/Hypothesis: The purpose of this study was to determine the regional recurrence rate of node-positive oropharyngeal squamous cell carcinoma (OPSCC) in patients undergoing transoral robotic surgery (TORS) and selective neck dissection (SND) followed by observation, radiation, or concurrent chemoradiation. Study Design: A prospective, phase I, single-arm study was conducted. All OPSCC patients who voluntarily participated in a surgical trial with TORS and SND at an academic tertiary referral center from May 2005 to July 2007 were included. Methods: Thirty-one patients with previously untreated OPSCC undergoing TORS and SND (29 unilateral and two bilateral) were included. There were 29 males and two females, with ages ranging from 36 to 76 years (median = 55 years) with one palate, one lateral wall, 17 tonsil, 11 base of tongue, and one vallecula primary tumor classified as follows: T1 (n = 9, 29%), T2 (n = 15, 48.4%), T3 (n = 7, 22.6%), N0 (n = 6, 19.4%), N1 (n = 15, 48.4%), N2b (n = 10, 32.3%), and N2c (n = 1, 3.2%). There were three stage I (9.7%), two stage II (6.5%), 15 stage III (48.4%) and 11 stage IVa (35.5%) patients. Twenty-two patients were treated postoperatively with adjuvant therapy (12 radiation alone and 12 combined radiation and chemotherapy). Primary outcome measured was regional recurrence rate. Results: There was one regional recurrence on the contralateral, non-operated neck and one distant recurrence among the 31 patients who underwent SND. Conclusions: SND after TORS resection of primary OPSCC enables the use of selective and deintensified adjuvant therapy to reduce regional recurrence rates. Laryngoscope, 2010 [source]

Anatomy of the Middle-Turn Cochleostomy,

THE LARYNGOSCOPE, Issue 12 2008
Brandon Isaacson MD
Abstract Objective: Middle-turn cochleostomies are occasionally used for cochlear implant electrode placement in patients with labyrinthitis ossificans. This study evaluates the anatomic characteristics of the middle-turn cochleostomy and its suitability for placement of implant electrodes. Methods: Ten cadaveric human temporal bones were dissected using a facial recess approach. A middle-turn cochleostomy was drilled 2 mm anterior to the oval window and just inferior to the cochleariform process. The preparations were then stained with osmium tetroxide and microdissections were performed. The location of the cochleostomy on the cochlear spiral and its path through the various cochlear compartments were evaluated in all 10 specimens. A Cochlear Corporation depth gauge was inserted in five of the specimens and insertion trauma, number of contact rings, and depth of insertion were recorded. Results: Eight of the 10 cochleostomies were placed at approximately 360° on the cochlear spiral, near the transition between the basal and middle turns. In one case, the cochleostomy was found to enter the cochlear apex and in another it entered scala vestibuli of the proximal basal turn. The cochleostomy entered scala media in six bones and scala vestibuli in four specimens. A depth gauge was inserted in five specimens. The number of contacts placed within the cochlear lumen ranged from four to nine. There was evidence of insertional trauma to the lateral wall of the cochlear duct, basilar membrane, and Reissner's membrane, but no evidence of fractures to the osseous spiral lamina or modiolus. Conclusion: This study demonstrates that electrodes inserted via a middle-turn cochleostomy are likely to enter scala vestibuli and have access to the middle- and apical-cochlear turns. It is also possible that the electrode could be directed into the descending portion of the basal turn depending on cochleostomy orientation. Middle-turn cochleostomy seems to be a viable alternative for electrode placement when preservation of residual hearing is not a concern. [source]

Chronologic Changes of Nitric Oxide Concentration in the Cochlear Lateral Wall and Its Role in Noise-Induced Permanent Threshold Shift

A morphometric study of the inferior orbital fissure using three-dimensional anatomical landmarks: Application to orbital surgery

CLINICAL ANATOMY, Issue 6 2009
Mehmet Asim Ozer
Abstract The inferior orbital fissure (IOF) is an important structure during orbital surgery, however, neither its anatomical features nor the procedures necessary to expose the IOF have been examined in detail. A morphometric analysis of the IOF was performed on 232 orbits using computer software. The longest and shortest borders of the IOF were 18.2 ± 4.9 and 1.9 ± 1.3 mm, respectively. The outer and the inner angles were 138.9 ± 32.7° and 38.4 ± 24.7°, respectively. The perimeter of the IOF was 50.6 ± 13.5 mm and its area was 61.3 ± 39.1 mm2. Eight types of IOF were observed. Type 1 IOF was observed in 42.2% and the Type 2 IOF was identified in 15.9%. A statistically significant relation was found between the longest edge and area and the widest edge and area of the IOF. The findings of our study suggest that the removal of the lateral wall should begin inferiorly, just lateral to the IOF and extended superolaterally. These data may be useful during surgical approaches to the orbit. Clin. Anat. 22:649,654, 2009. © 2009 Wiley-Liss, Inc. [source]

Paraclinoid and cavernous sinus regions: Measurement of critical structures relevant for surgical procedure

CLINICAL ANATOMY, Issue 1 2005
Frederic Collignon
Abstract Determination of the safest distance the falciform ligament can be incised from its origin to the orbital apex. Measurement of the distance between the oculomotor foramen and the IV nerve in the lateral wall of the cavernous sinus. Evaluation of the optic strut as an accurate landmark between the intradural (subarachnoid) and extradural segment of the internal carotid artery (ICA). Ten fixed human cadaver heads were examined for a total of 20 sides. A frontotemporal craniotomy, an orbito-optic osteotomy, and extradural anterior clinoidectomy were carried out followed by opening the falciform ligament, circumferentially releasing the distal dural ring and dissection of the lateral wall of the cavernous sinus under the operating microscope. We measured: 1) the distance between the entry of the III nerve and the point where the IV nerve crosses over it into the cavernous sinus; 2) the distance the falciform ligament can be incised along the optic nerve laterally until the IV nerve is encountered at the orbital apex; 3) the distance between the optic strut and the lateral part of the distal dural ring; and 4) the distance between the optic strut and the ophthalmic artery. All measurements were made in millimeters, using small calipers. The distance between the optic strut and the lateral part of the distal dural ring ranges from 3,7.5 mm (mean = 5.47 mm). In all our specimens, the ophthalmic artery was found distally from the optic strut in the intradural space at a distance ranging from 0.5,7 mm (mean = 3.35 mm). The distance between the entry of the third nerve and the IV nerve into the cavernous sinus ranged from 7,15 mm (mean = 10.9 mm). The distance between the origin of the falciform ligament and the IV nerve at the level of the orbital apex ranged from 9,15 mm (mean = 10.75 mm). The falciform ligament and the optic sheath should not be opened longer than 9 mm along the lateral optic nerve or injury to the IV nerve can occur. Starting at the oculomotor foramen, the opening of the cavernous sinus should be limited to 7 mm to avoid injuring the IV nerve. Finally, the optic strut can be a reliable bony landmark that separates the subarachnoid space and extradural compartments along the anterior and medial ICA. Clin. Anat. 18:3,9, 2005. © 2004 Wiley-Liss, Inc. [source]

Does stimulation of nasal mucosa cause referred pain to the face?

CLINICAL OTOLARYNGOLOGY, Issue 5 2001
M. Abu-Bakra
Ten healthy volunteers (five men and five women, mean age 30 years 3 months), with no nasal contact points, had pressure, adrenaline (1 : 1000), substance P (10 and 80 nmol/mL) and placebo topically applied to their nasal mucosa. Areas stimulated were the nasal floor, septum and lateral wall as well as the inferior and middle turbinates in both nasal cavities. The application of stimuli was randomized and single-blinded. A numerical score of the subjective severity of pain was used to assess outcome. Pressure caused variable local nasal discomfort limited by the duration of application and the site of pressure. Substance P caused variable nasal itching and sneezing. None of the stimuli caused referred pain to the face. The results question the role of mucosal contact points in facial pain. [source]

An Echocardiographic Analysis of the Long-Term Effects of Carvedilol on Left Ventricular Remodeling, Systolic Performance, and Ventricular Filling Patterns in Dilated Cardiomyopathy

ECHOCARDIOGRAPHY, Issue 7 2005
Peter S. Rahko M.D.
Background: The long-term clinical benefit of beta blockade is well recognized, but data quantifying long-term effects of beta blockade on remodeling of the left ventricle (LV) is limited. Methods: This consecutive series evaluates the long-term response of the LV to the addition of carvedilol to conventional therapy for dilated cardiomyopathy. There were 33 patients who had a LV ejection fraction <45%, LV enlargement and symptomatic heart failure. Quantitative Doppler echocardiography was performed at baseline 6, 12, 24, and 36 months after initiation of carvedilol to evaluate LV ejection fraction, LV volume, wall stress, mass, regional function, and diastolic performance. Results: Compared to baseline there was a significant and sustained reduction in end-systolic volume and end-systolic wall stress with a corresponding improvement in LV ejection fraction. The LV mass did not decline but relative wall thickness increased toward normal. An analysis of regional wall motion responses showed an improvement in all areas, particularly the apical, septal, and lateral walls that was significantly more frequent in patients with a nonischemic etiology. Filling patterns of the LV remained abnormal throughout the study but changed with therapy suggesting a decline in filling pressures. These changes were sustained for 3 years. Conclusion: (1) The addition of carvedilol to conventional therapy for a dilated cardiomyopathy significantly improves LV ejection fraction and reduces LV end-systolic volume and wall stress for at least 3 years, (2) the response to 6 months of treatment predicts the long-term response, (3) the typical response is partial improvement of the LV, complete return to normal size, and function is uncommon, and (4) abnormalities of LV filling persist in virtually all patients throughout the course of treatment. [source]

Clinical anatomy of the equine sphenopalatine sinus

EQUINE VETERINARY JOURNAL, Issue 6 2004
J. L. McCANN
Summary Reasons for performing study: Disorders of the equine sphenopalatine sinus, including empyema and neoplasia, have been reported to cause damage to cranial nerves II and V. However, the clinical anatomy of these sinuses is not well described in horses. Objective: To examine the anatomy of the sphenopalatine sinuses in a range of equidae and, in particular, to examine the relationship of these sinuses to adjacent major nerves and vessels. Methods: The anatomy of the sphenoidal and palatine paranasal sinuses was examined in 16 equidae, primarily using transverse skull sections. Relevant structures were documented and photographed. Results: There was much variation between individual horses in sphenopalatine sinus anatomy. The sphenoidal sinuses were small in young horses and appeared to become larger and more complex with age. Variation was present in the extent that the sphenopalatine sinus extended into the basisphenoid bone. The septum dividing left and right sphenoidal sinuses was frequently not midline, but was intact in all cases. The sphenoidal and palatine sinuses communicated in most horses. In such cases, what could accurately be termed the (combined) sphenopalatine sinuses usually drained directly into the caudal maxillary sinuses. Additionally, in 5 out of 16 cases, some compartments of the sphenoidal sinus also drained into the ethmoidal sinus. The dorsal and lateral walls of the sphenoidal sinus were very thin and directly adjacent to cranial nerves II, III, IV, V and VI and major blood vessels. Conclusions: The equine sphenoidal and palatine sinuses are very variable in their anatomy, but are always in close proximity to multiple cranial nerves and major blood vessels. Potential relevance: Many cranial nerves and blood vessels could be damaged with disorders involving the sphenopalatine sinus, potentially causing major and variable neurological syndromes, haemorrhage and extension of sepsis. [source]

Effects of stylopharyngeus muscle dysfunction on the nasopharynx in exercising horses

EQUINE VETERINARY JOURNAL, Issue 4 2004
C. TESSIER
Summary Reasons for performing study: Nasopharyngeal collapse has been observed in horses as a potential cause of exercise intolerance and upper respiratory noise. No treatment is currently available and affected horses are often retired from performance. Objective: To determine the effect of bilateral glossopharyngeal nerve block and stylopharyngeus muscle dysfunction on nasopharyngeal function and airway pressures in exercising horses. Methods: Endoscopic examinations were performed on horses at rest and while running on a treadmill at speeds corresponding to HRmax50, HRmax75 and HRmax, with upper airway pressures measured with and without bilateral glossopharyngeal nerve block. Results: Bilateral glossopharyngeal nerve block caused stylopharyngeus muscle dysfunction and dorsal nasopharyngeal collapse in all horses. Peak inspiratory upper airway pressure was significantly (P = 0.0069) more negative at all speeds and respiratory frequency was lower (P = 0.017) in horses with bilateral glossopharyngeal nerve block and stylopharyngeus muscle dysfunction compared to control values. Conclusions: Bilateral glossopharyngeal nerve anaesthesia produced stylopharyngeus muscle dysfunction, dorsal pharyngeal collapse and airway obstruction in all horses. Potential relevance: The stylopharyngeus muscle is probably an important nasopharyngeal dilating muscle in horses and dysfunction of this muscle may be implicated in clinical cases of dorsal nasopharyngeal collapse. Before this information can be clinically useful, further research on the possible aetiology of stylopharyngeus dysfunction and dysfunction of other muscles that dilate the dorsal and lateral walls of the nasopharynx in horses is needed. [source]

Critical appraisal of the mouse model of myocardial infarction

EXPERIMENTAL PHYSIOLOGY, Issue 4 2004
Naomi M. Degabriele
In order to critically evaluate the utility of a mouse model of myocardial infarction (MI) for therapeutic studies, we investigated survival, haemodynamic measurements and histopathology in mice with an occluding suture placed at one of three distinct sites along the left anterior descending coronary artery. The suture was placed at the atrioventricular juncture (High), or at two sites more distally towards the base (Middle and Low). In the High group, only 33% of animals survived 7 days after MI (P < 0.05 compared to all other groups). Only the Middle group had significantly reduced haemodynamics compared to sham-operated animals (maximum left ventricular pressure: 55.9 ± 3.5 versus 80.8 ± 5.1 mmHg, maximum change in pressure over time : 2003 ± 172 versus 4402 ± 491, P < 0.01). Histological examination showed morphological changes in all MI groups. The Middle group had larger lesions than the Low group (P < 0.05). Lesions in the anterior and lateral walls correlated, albeit weakly, with cardiac function. Power calculations indicated that, despite a certain amount of intragroup variation, the Middle Suture model may be useful for therapeutic studies to assess the effects of treatment on cardiac function and overall lesion size. [source]

The Right Gastroepiploic Artery in Coronary Artery Bypass Grafting

JOURNAL OF CARDIAC SURGERY, Issue 4 2008
Hideki Sasaki M.D.
Although some reports presenting good results justify its use in clinical settings, there is still much concern about using the RGEA in bypass surgery. The RGEA demonstrates different behaviors from the internal thoracic artery (ITA) in bypass surgery due to its histological characteristics and anatomical difference, which might contribute to the long-term outcome. Now that left ITA (LITA) to left anterior descending artery (LAD) is the gold standard, other grafts are expected to cover the rest of the coronary arteries. It should be elucidated how we can use other grafts and what we can expect from them. RGEA, as an arterial graft, can be used as an in situ graft or a free graft. The RGEA is mainly used to graft to the right coronary artery (RCA) because of its anatomical position, and its patency is not inferior to that of the saphenous vein (SVG). The RGEA can cover the lateral walls when its length is long enough or by making a composite graft with other grafts. However, when used to graft to the LAD, its mid-term patency is not favorable. [source]

Larynx morphology and sound production in three species of Testudinidae

JOURNAL OF MORPHOLOGY, Issue 2 2004
Roberto Sacchi
Abstract Although the ability to vocalize is widespread among tortoises, the mechanisms of sound production in chelonians remain undescribed. In this study, we analyze the morphology and histology of the larynx of three species of Testudinidae (Testudo hermanni, T. graeca, and T. marginata) in order to ascertain the presence of vibrating acoustic structure, and based on our findings we propose a general model for phonation in tortoises. The structure of the larynx of the three tortoises analyzed is simple: three cartilages (the cricoid and two arytenoids) form the skeleton of the larynx, while two pairs of muscles (the dilators and constrictors) control the widening and closing of the glottis. The larynx is supported in the oral cavity by the hyoid cartilage, which in tortoises assumes the same functions of the thyroid cartilage of mammals. Two bands of elastic fibers are inserted in the lateral walls of the larynx just upstream of the glottis, and can be stretched away from the hyoid by the movements of the arytenoids. Their position and structure suggest that these bands are capable of vibrating during exhalation, and therefore may be considered vocal cords. The cricoid of T. marginata and T. graeca hold two diverticula, not previously reported, which might function as a low-frequency resonating chamber, improving the harmonic structure of tortoise calls. The structure of the larynx is compared with that of other vertebrates and the relationships between morphology and phonation are discussed. This is the first detailed description of anatomical structures possibly devoted to vocalization in chelonians. J. Morphol. 261:175,183, 2004. © 2004 Wiley-Liss, Inc. [source]

Étude de l'influence de l'évaporation d'un bac d'eau sur les transferts dans un canal corrugué

THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2000
Seghir Maamir
Abstract Les auteurs présentent une étude numérique et expérimentale des transferts qui s'effectuent par convection forcée dans un canal comportant une protubérance sinusoîdale et par convection naturelle dans un bac d'eau. L'étude numérique a été effectuée pour des nombres de Reynolds compris entre 35 et 350, plusieurs densité de flux de chaleur et pour des amplitudes de la protubérance comprises entre 0.005 et 0.02 m. Les résultats montrent que la diffusion de la vapeur d'eau dans l'air modifie le profil des lignes de courant qui devient convexe au-dessus de la surface libre de l'eau. En outre, l'evaporation atténue la perturbation engendrée par la protubérance et augmente les transferts de chaleur dans le canal. La visualisation de l'ecoulement, réalisée à l'aide d'un générateur de fumée d'encens, d'un laser à argon et d'une caméra vidéo à mis en évidence la complexité de l'interaction entre le flux de vapeur engendré par l'évaporation de l'eau du bac, l'écoulement de l'air dans le canal et les déperditions de chaleur à travers les parois latérales. Les résultats théoriques et expéri-mentaux sont en bon accord qualitatif. The authors present a numerical and experimental study on heat and mass transfers by forced convection in a channel with a sinusoidal protuberance and by natural convection in a reservoir full of water. The numerical study has been carried out for Reynolds numbers in a range of 35 to 350, several densities of heat flux and protuberance amplitude range of 0.005 to 0.02 m. Results show that the vapour diffusion in the air modifies the stream function profiles which become convex over the free surface of the water. In addition, the evaporation reduces the perturbation caused by the protuberance and increases the heat transfer rate in the channel. The visualisation of the flow, using smoke, an argon laser and a videocamera, shows the complexity of the interaction between the flow of vapour caused by the evaporation, the flow in the channel and the heat losses across the lateral walls. Theoretical and experimental results are in good qualitative agreement. [source]

Developing a Rabbit Model of Rhinogenic Chronic Rhinosinusitis,

THE LARYNGOSCOPE, Issue 6 2008
Kai-Li Liang MD
Abstract Objective: The purpose of this study was to develop a rabbit model of rhinogenic chronic rhinosinusitis (CRS). Methods: New Zealand white rabbits were used and divided into two groups. In group A rabbits, a piece of Merocel (Medtronic-Xomed, Jacksonville, FL) was inserted into one nasal cavity and the other was left undisturbed as control. In group B rabbits, 1 ,g phorbol 12-myristate 13-acetate (PMA) was injected into bilateral nasal lateral walls and then a piece of Merocel (Medtronic-Xomed) was inserted into one nasal cavity. At week 2, the Merocel (Medtronic-Xomed) was removed, and computed tomography (CT), nasoendoscopy, and cultures were performed. All examinations were repeated at week 12. Rabbits that had purulent discharge in nasal cavities and sinuses opacification shown in CT scans were diagnosed as having rhinosinusitis. Rabbits with CRS were randomly allocated to receive intravenous ceftriaxone (50 mg/kg/day) for 28 days or nothing. All rabbits with CRS received CT scans, nasoendoscopy, and cultures at week 16. Results: At week 12, CRS had developed in two controlled nasal cavities, six nasal cavities inserted with Merocel (Medtronic-Xomed), six nasal cavities injected with phorbol 12-myristate 13-acetate (PMA), and seven both PMA-injected and Merocel- (Medtronic-Xomed) inserted nasal cavities. Seven of nine treated CRS sides were clear of opacification after treatment. All non-treated CRS sides had persistent diseases at week 16. There was a significant difference in the CRS incidence (P = .00043) and culture rates (P = .027) between treated and non-treated CRS nasal cavities. Conclusions: Our study developed a rabbit model of rhinogenic CRS. This model is easily performed and is reversible by treatment. [source]

Early Embryonic Development of the Camel Lumbar Spinal Cord Segment

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2005
M. E. Abd Elmonem
The lumbar spinal cord segment of the camel embryo at CVRL 2.4 to 28 cm was examined. Major changes are occurring in the organization of the lumbar spinal cord segments during this early developmental period. At the CVRL 2.4, 2.7 and 3.6 cm the three primary layers, ependymal cells layer, mantle cells layer, marginal cells layer in the developing lumber spinal cord segment were demonstrated. The mantle layer is the first to show striking differentiation, while the marginal layer is represented by thin outer rim. Proliferation and differentiation of the neuroepithelial cells in the developing spinal cord produce the thick lateral walls, thin roof and floor plates. The spinal ganglion and dorsal root of the spinal nerve are differentiated. At 2.7 cm CVRL differential thickening of the lateral walls produces a shallow longitudinal groove called sulcus limitans, which separates the dorsal part (alar plate) from ventral part (basal plate). The ventral root of the spinal nerve, the spinal cord and ganglion are embedded in loose mesenchyme, which tends to differentiate into spinal meninges. At 3.6 cm CVRL the basal plate, which is the future ventral gray horn, seem to be quite voluminous and the dorsal and ventral roots unite to form the beginning of the spinal nerve. At 5.5 cm CVRL the alar plates enlarge forming the dorsal septum. At 8.4 cm to 10.5 cm CVRL the basal plates enlarge, and bulge ventrally on each side of the midline producing the future ventral medium fissure, and the white and gray matters can be recognized. At 28 cm CVRL the lumen of the spinal cord is differentiated into the central canal bounded dorsally and ventrally by dorsal and ventral gray commissures, and therefore the gray matter takes the appearance of a butterfly. The lumber spinal nerve and their roots are well distinguished. [source]