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Lateral Edge (lateral + edge)
Selected AbstractsHypoxia-sensing properties of the newborn rat ventral medullary surface in vitroTHE JOURNAL OF PHYSIOLOGY, Issue 1 2006N. Voituron The ventral medullary surface (VMS) is a region known to exert a respiratory stimulant effect during hypercapnia. Several studies have suggested its involvement in the central inhibition of respiratory rhythm caused by hypoxia. We studied brainstem,spinal cord preparations isolated from newborn rats transiently superfused with a very low O2 medium, causing reversible respiratory depression, to characterize the participation of the VMS in hypoxic respiratory adaptation. In the presence of 0.8 mm Ca2+, very low O2 medium induced an increase in c-fos expression throughout the VMS. The reduction of synaptic transmission and blockade of the respiratory drive by 0.2 mm Ca2+,1.6 mm Mg2+ abolished c-fos expression in the medial VMS (at the lateral edge of the pyramidal tract) but not in the perifacial retrotrapezoid nucleus/parafacial respiratory group (RTN/pFRG) VMS, suggesting the existence of perifacial RTN/pFRG hypoxia-sensing neurons. In the presence of Ca2+ (0.8 mm), lesioning experiments suggested a physiological difference in perifacial RTN/pFRG VMS between the lateral VMS (beneath the ventrolateral part of the facial nucleus) and the middle VMS (beneath the ventromedial part of the facial nucleus), at least in newborn rats. The lateral VMS lesion, corresponding principally to the most rostral part of the pFRG, produced hypoxia-induced stimulation, whereas the middle VMS lesion, corresponding to the main part of the RTN, abolished hypoxic excitation. This may involve relay via the medial VMS, which is thought to be the parapyramidal group. [source] Biomechanics of the Fractured Medial Coronoid Process and the Isolated Anconeal Process in the Canine Elbow JointANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2005J. Maierl Introduction:, Elbow dysplasia is one of the most important orthopaedic diseases of the canine elbow joint. The medial coronoid process (MCP) and the anconeal process (AP) are involved with a high incidence. Aims:, The aim of this study was to clarify whether these processes are especially loaded resulting in osteoarthrosis. Material and Methods:, Elbow joints were examined from dogs of various breeds, with a body weight over 20 kg and an age ranging from 1 to 12 years. Only joints without damage to the articular cartilage have been included in this investigation. Articular surfaces have been evaluated macroscopically, subchondral bone density (long-term loading) and split-lines (long-term tensile loading) have been determined. Results:, In the humeral fossa olecrani, there was a distinct impression on the inner side of the lateral compared to the medial epicondyle. In the ulna, the MCP was much greater than the lateral coronoid indicating that the medial process has to support the humeral condyle to a higher extent. Subchondral split lines with a transverse orientation in the fossa olecrani gave evidence of long-term transverse tensile loading in this area. Split lines on the MCP were oriented radially as if the lateral edge was bent downwards. Subchondral bone density in the fossa olecrani was higher towards the lateral epicondyle in comparison to the medial. Furthermore, there was a bone density maximum on the medial part of the humeral condyle opposite of the MCP with its very high density. Discussion:, Gait analyses showed that there is a transverse, medially oriented force of up to 4% bodyweight acting on the paw during midstance. As the carpus is stable when slightly hyperextended during midstance loading there is a long lever arm from the ground up to an assumed rotation centre in the depth of the trochlear notch. The medially directed ground reaction force slightly rotates the forearm inwards causing a bending moment about the elbow joint, which leads to an increased pressure of the AP and the MCP. This bending in addition to sagittal loading is the reason for the high susceptibility of the MCP and AP. [source] Minimal access thyroid surgery: technique and report of the first 25 casesANZ JOURNAL OF SURGERY, Issue 5 2004Jessica E. Gosnell Background: Minimal access thyroid surgery, using various techniques, is increasingly being reported. The present study reviews our experience with thyroid surgery using a lateral focused mini-incision approach, and assesses its safety and feasibility. Methods: The study group comprised all patients undergoing minimal access thyroid surgery (MATS) during the period May 2002,May 2003. Data were prospectively gathered, including patient demographics, indication for surgery, operation performed, nodule size, final pathology, and complications. Exclusion criteria for this procedure included: family history of thyroid cancer, previous neck irradiation or surgery, carcinoma on fine needle aspiration, presence of significant thyroiditis, multinodular goitre, and nodule size >3 cm. The operation was carried out through a 2.5-cm lateral incision placed directly over the nodule, with exposure gained by dissecting the plane between the sternomastoid muscle and the lateral edge of the strap muscles. Results: Twenty-five patients underwent MATS, 22 women and three men. Nineteen patients underwent hemithyroidectomy, five underwent isthmectomy, and one underwent local nodule excision. The average measured incision size was 2.63 cm at the end of the procedure. The average nodule size was 2.2 cm, and the average thyroid lobe resected measured 4.7 cm in maximal length. Final pathology revealed benign nodules in 21 patients and four thyroid cancers (two follicular and two papillary). There was one wound infection and two patients had temporary recurrent laryngeal nerve neuropraxia. Conclusion: Minimal access thyroid surgery is a safe and feasible alternative to open thyroid surgery in selected cases. [source] A clinicoanatomical study of the novel nerve fibers linked to stress urinary incontinence: The first morphological description of a nerve descending properly along the anterior vaginal wallCLINICAL ANATOMY, Issue 3 2007Susumu Yoshida Abstract When performing anterior colporrhaphy for cystocele, most pelvic surgeons have not considered the neuroanatomy that contributes to urethral function. The aim of the study was to anatomically identify nerve fibers located in the anterior vagina associated with the pathogenesis of incontinence and pelvic organ prolapse. Anterior vaginal specimens were obtained from 17 female cadavers and 33 cases of clinical cystocele by anterior vaginal resection. The specimens were step-sectioned and stained with hematoxylin-eosin, S100 antibody, and tyrosine hydroxylase antibody. As a result, descending nerves 50,200 ,m in thickness were identified between the urethra and vagina. They were located more than 10 mm medially from a cluster of nerves found almost along the lateral edge of the vagina and stained with S100 and tyrosine hydroxylase antibody, originated from the cranial part of the pelvic plexus, and appeared to terminate at the urethral smooth muscles. The authors classified the density of S100 positive nerve fibers in the anterior vaginal wall obtained from clinically operated cases of cystocele into three grades (Grade 1, nothing or a few thin nerves less than 20 ,m in diameter; Grade 2, thick nerves more than 50 ,m in diameter and thin nerves; Grade 3, more than 3 thick nerves in one field at an objective magnification of 40××). Mean urethral mobility (Q-tip) values (28.1° ±± 19.6°) observed in the Grade 3 cases was significantly lower than those (50.0° ±± 27.4° and 59.4° ±± 19.9°) in Grade 2 and Grade 1, respectively. In addition, the presence of preoperative or postoperative stress urinary incontinence in the cases of Grade 1 was significantly higher than those of the cases with S100 positive stained nerves. In conclusion, the novel nerve fibers immunohistochemically identified in the anterior vaginal wall are different from those of the common nervous system or the pelvic floor and are associated with the pathogenesis of urethral hypermobility. Clin. Anat. 20:300,306, 2007. © 2006 Wiley-Liss, Inc. [source] Coexistence of a pectoralis quartus muscle and an unusual axillary arch: Case report and reviewCLINICAL ANATOMY, Issue 5 2002Victoria Bonastre Abstract A pectoralis quartus muscle and an unusual axillary arch were found on the left side of a female cadaver. The axillary arch was a musculoaponeurotic complex continuous with the iliacal fibers of the latissimus dorsi. The muscular part, together with the tendon of pectoralis major, inserted into the lateral lip of the bicipital groove of the humerus, whereas the aponeurotic part was formed by a fibrous band that extended deep to the pectoralis major to insert into the coracoid process between the attachments of the coracobrachialis and pectoralis minor. The pectoralis quartus originated from the rectus sheath, and joined the inferior medial border of the fibrous band of the axillary arch, at the lateral edge of the pectoralis major. The axillary arch muscle crossed anteriorly the axillary vessels and the brachial plexus. The clinical importance of these muscles is reviewed. Clin. Anat. 15:366,370, 2002. © 2002 Wiley-Liss, Inc. [source] Matrix metalloproteinase-dependent shedding of syndecan-3, a transmembrane heparan sulfate proteoglycan, in Schwann cellsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 5 2003Vinod K. Asundi Abstract Schwann cells transiently express the transmembrane heparan sulfate proteoglycan syndecan-3 during the late embryonic and early postnatal periods of peripheral nerve development. Neonatal rat Schwann cells released soluble syndecan-3 into the culture medium by a process that was blocked by inhibition of endogenous matrix metalloproteinase activity. When Schwann cells were plated on a substratum that binds syndecan-3, the released proteoglycan bound to the substratum adjacent to the cell border. Membrane-anchored syndecan-3 was concentrated in actin-containing filopodia that projected from the lateral edges of the Schwann cell membrane. Membrane shedding was specific for syndecan-3 and was not observed for the related proteoglycan syndecan-1. Analysis of Schwann cells transfected with wild-type and chimeric syndecan-1 and syndecan-3 cDNAs revealed that membrane shedding was a property of the syndecan-3 ectodomain. Inhibition of syndecan-3 release significantly enhanced Schwann cell adhesion and process extension on dishes coated with the non-collagenous N-terminal domain of ,4(V) collagen, which binds syndecan-3 and mediates heparan sulfate-dependent Schwann cell adhesion. Matrix metalloproteinase-dependent syndecan-3 shedding was also observed in newborn rat peripheral nerve tissue. Syndecan-3 shedding in peripheral nerve tissue was age specific, and was not observed during later stages of postnatal nerve development. These results demonstrate that Schwann cell syndecan-3 is subject to matrix metalloproteinase-dependent membrane processing, which modulates the biological function of this proteoglycan. © 2003 Wiley-Liss, Inc. [source] Morphological mechanisms for regulating blood flow through hepatic sinusoidsLIVER INTERNATIONAL, Issue 1 2000Robert S. McCuskey Abstract: This review summarizes what is known about the various morphological sites that regulate the distribution of blood flow to and from the sinusoids in the hepatic microvascular system. These sites potentially include the various segments of the afferent portal venules and hepatic arterioles, the sinusoids themselves, and central and hepatic venules. Given the paucity of smooth muscle in the walls of these vessels, various sinusoidal lining cells have been suggested to play a role in regulating the diameters of sinusoids and influencing the distribution and velocity of blood flow in these vessels. While sinusoidal endothelial cells have been demonstrated to be contractile and to exhibit sphincter function, attention has recently focused on the perisinusoidal stellate cell as the cell responsible for controlling the sinusoidal diameter. A very recent study, however, suggested that the principal site of vasoconstriction elicited by ET-1 was the pre-terminal portal venule. This raised the question of whether or not the diameters of sinusoids might decrease due to passive recoil when inflow is reduced or eliminated and intra-sinusoidal pressure falls. In more recent in vivo microscopic studies, clamping of the portal vein dramatically reduced sinusoidal blood flow as well as the diameters of sinusoids. The sinusoidal lumens rapidly returned to their initial diameters upon restoration of portal blood flow suggesting that sinusoidal blood pressure normally distends the sinusoidal wall which can recoil when the pressure drops. Stellate cells may be responsible for this reaction given the nature of their attachment to parenchymal cells by obliquely oriented microprojections from the lateral edges of their subendothelial processes. This suggests that care must be exercised when interpreting the mechanism for the reduction of sinusoidal diameters following drug administration without knowledge of changes occurring to the portal venous and hepatic inflow. [source] | |||||||||||||