966 resultados para Lateral rotation of the tibia
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The olfactory neuroepithelium is characterised by the mosaic distribution of primary olfactory neurons that express different odorant receptors and cell surface glycoconjugates. Carbohydrates are believed to form a glycocode that mediates sorting out and fasciculation of primary olfactory axons through interactions with carbohydrate-binding proteins such as galectin-1. In the present study, we describe in detail the expression pattern of galectin-1 in the developing and adult rat olfactory system. We demonstrate that galectin-1 is expressed by olfactory ensheathing cells both in olfactory nerve and within the nerve fibre layer of the olfactory bulb of the embryonic and adult rat. In the adult rat, galectin-1 was preferentially expressed by olfactory ensheathing cells in the nerve fibre layer of the ventromedial and lateral surfaces of the olfactory bulb. Galectin-1 was also expressed by subsets of periglomerular cells and granule cells, particularly in the ventromedial region of the olfactory bulb. In adult rat, the galectin-1 ligand, N-acetyl-lactosamine, was expressed by primary olfactory axons that terminated in glomeruli present in the ventromedial and lateral olfactory bulb. These results suggest that expression of galectin-1 may provide a mechanism for the sorting of subpopulations of axons in the nerve fibre layer of the olfactory bulb during development as well as play a role in the postnatal maintenance of specific glomerular connections. (C) 1999 Elsevier Science B.V. All rights reserved.
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In the first of three experiments, 11 participants generated pronation and supination movements of the forearm, in time with an auditory metronome. The metronome frequency was increased in eight steps (0.25 Hz) from a base frequency of 1.75 Hz. On alternating trials, participants were required to coordinate either maximum pronation or maximum supination with each beat of the metronome. In each block of trials, the axis of rotation was either coincident with the long axis of the forearm, above this axis, or below this axis. The stability of the pronate-on-the-beat pattern, as indexed by the number of pattern changes, and the time of onset of pattern change, was greatest when the axis of rotation of the movement was below the long axis of the forearm. In contrast, the stability of the supinate-on-the-beat pattern was greatest when the axis of rotation of the movement was above the long axis of the forearm. In a second experiment, we examined how changes in the position of the axis of rotation alter the activation patterns of muscles that contribute to pronation and supination of the forearm. Variations in the relative dominance of the pronation and supination phases of the movement cycle across conditions were accounted for primarily by changes in the activation profile of flexor carpi radialis (FCR) and extensor carpi radialis longus (ECR). In the Final experiment we examined how these constraints impact upon the stability of bimanual coordination. Thirty-two participants were assigned at random to one of four conditions, each of which combined an axis of rotation configuration (bottom or top) for each limb. The participants generated both inphase (both limbs pronating simultaneously, and supinating simultaneously) and antiphase (left limb pronating and right limb supinating simultaneously, and vice versa) patterns of coordination. When the position of the axis of rotation was equivalent for the left and the right limb, transitions from antiphase to inphase patterns of coordination were Frequently observed. In marked contrast, when the position of the axis of rotation for the left and right limb was contradistinct, transitions From inphase to antiphase patterns of coordination occurred. The results demonstrated that when movements are performed in an appropriate mechanical context, inphase patterns of coordination are less stable than antiphase patterns.
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Establishment of the left-right axis is a fundamental process of vertebrate embryogenesis. Failure to develop left-right asymmetry leads to incorrect positioning and morphogenesis of numerous internal organs, and is proposed to underlie the etiology of several common cardiac malformations. The transcriptional modulator Cited2 is essential for embryonic development: Cited2-null embryos die during gestation with profound developmental abnormalities, including cardiac malformations, exencephaly and adrenal agenesis. Cited2 is also required for normal establishment of the left-right axis; we demonstrate that abnormal heart looping and right atrial and pulmonary isomerism are consistent features of the left-right-patterning defect. We show by gene expression analysis that Cited2 acts upstream of Nodal, Lefty2 and Pitx2 in the lateral mesoderm, and of Lefty1 in the presumptive floor plate. Although abnormal left-right patterning has a major impact on the cardiac phenotype in Cited2-null embryos, laterality defects are only observed in a proportion of these embryos. We have therefore used a combination of high-resolution imaging and three-dimensional (3D) modeling to systematically document the full spectrum of Cited2-associated cardiac defects. Previous studies have focused on the role of Cited2 in cardiac neural crest cell development, as Cited2 can bind the transcription factor Tfap2, and thus affect the expression of Erbb3 in neural crest cells. However, we have identified Cited2-associated cardiac defects that cannot be explained by laterality or neural crest abnormalities. In particular, muscular ventricular septal defects and reduced cell density in the atrioventricular (AV) endocardial cushions are evident in Cited2-null embryos. As we found that Cited2 expression tightly correlated with these sites, we believe that Cited2 plays a direct role in development of the AV canal and cardiac septa. We therefore propose that, in addition to the previously described reduction of cardiac neural crest cells, two other distinct mechanisms contribute to the spectrum of complex cardiac defects in Cited2-null mice; disruption of normal left-right patterning and direct loss of Cited2 expression in cardiac tissues.
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Recent investigations in the upper Rio Huallaga in Peru revealed the presence of an intriguing species of the Loricariinae. To characterize and place this species within the evolutionary tree of the subfamily, a molecular phylogeny of this group was inferred based on the 12S and 16S mitochondrial genes and the nuclear gene F-reticulon4. The phylogeny indicated that this distinctive species was a member of the subtribe Loricariina. Given its phylogenetic placement, and its unusual morphology, this species is described as a new genus and new species of Loricariinae: Fonchiiloricaria nanodon. This new taxon is diagnosed by usually possessing one to three premaxillary teeth that are greatly reduced; lips with globular papillae on the surface; the distal margin of lower lip bearing short, triangular filaments; the premaxilla greatly reduced; the abdomen completely covered by plates, with the plates between lateral abdominal plates small and rhombic; a caudal fin with 14 rays; the orbital notch absent; five lateral series of plates; dorsal-fin spinelet absent; preanal plate present, large and solid, and of irregular, polygonal shape, the caudal peduncle becoming more compressed posteriorly for the last seven to 10 plates. (C) 2011 The Authors Journal of Fish Biology (C) 2011 The Fisheries Society of the British Isles
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Telecanthus, the lateral displacement of the medial canthus, can be a congenital deformity or can occur after facial trauma or tumor resection. Treatment of telecanthus remains a challenge for plastic surgeons. For proper correction, it is necessary to shift the medial canthus medially, fixing its tendon to the bone. The ideal technique would allow easy, safe, and stable fixation of the tendon, permit a unilateral approach with minimal incisions, and be cost-effective. The purpose of this study was to evaluate the feasibility and results (immediate and long-term) of medial telecanthus repair using ipsilateral titanium microanchor fixation. Nine patients, 7 with unilateral telecanthus and 2 with bilateral telecanthus, underwent ipsilateral canthopexy involving a microanchor device. Anthropometric measurements of the orbital regions were taken before, immediately after, and at 1 year after surgery. Data for the affected sides were compared with those for the unaffected sides, and the evolution of those values was assessed throughout the 1-year follow-up period. For all patients, the final values were lower than those initially obtained. At 1 year after surgery, the intercanthal distance was reduced to age-adjusted normal values in all cases. On the operated side, stable improvement was observed in terms of the distance from the medial canthus to the midline, although some degree of recurrence was noted in most of the patients. The use of a microanchor system for medial canthopexy can be considered an easily performed and effective option for treating canthal dystopia, especially when an ipsilateral approach is preferred.
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H-1 NMR spectra of the thyroid hormone thyroxine recorded at low temperature and high field show splitting into two peaks of the resonance due to the H2,6 protons of the inner (tyrosyl) ring. A single resonance is observed in 600 MHz spectra at temperatures above 185 K. An analysis of the line shape as a function of temperature shows that the coalescence phenomenon is due to an exchange process with a barrier of 37 kJ mol(-1). This is identical to the barrier for coalescence of the H2',6' protons of the outer (phenolic) ring reported previously for the thyroid hormones and their analogues. It is proposed that the separate peaks at low temperature are due to resonances for H2,6 in cisoid and transoid conformers which are populated in approximately equal populations. These two peaks are averaged resonances for the individual H2 and H6 protons. Conversion of cisoid to transoid forms can occur via rotation of either the alanyl side chain or the outer ring, from one face of the inner ring to the other. It is proposed that the latter process is the one responsible for the observed coalescence phenomenon. The barrier to rotation of the alanyl side chain is greater than or equal to 37 kJ mol(-1), which is significantly larger than has previously been reported for Csp(2)-Csp(3) bonds in other Ph-CH2-X systems. The recent crystal structure of a hormone agonist bound to the ligand-binding domain of the rat thyroid hormone receptor (Wagner et al. Nature 1995, 378, 690-697) shows the transoid form to be the bound conformation. The significant energy barrier to cisoid/transoid interconversion determined in the current study combined with the tight fit of the hormone to its receptor suggests that interconversion between the forms cannot occur at the receptor site but that selection for the preferred bound form occurs from the 50% population of the transoid form in solution.
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We examined the role of cytokinins (CKs) in release of apical dominance in lateral buds of chickpea (Cicer arietinum L.). Shoot decapitation or application of CKs (benzyladenine, zeatin or dihydrozeatin) stimulated rapid bud growth. Time-lapse video recording revealed growth initiation within 2 h of application of 200 pmol benzyladenine or within 3 h of decapitation. Endogenous CK content in buds changed little in the first 2 h after shoot decapitation, but significantly increased by 6 h, somewhat later than the initiation of bud growth. The main elevated CK was zeatin riboside, whose content per bud increased 7-fold by 6 h and 25-fold by 24 h. Lesser changes were found in amounts of zeatin and isopentenyl adenine CKs. We have yet to distinguish whether these CKs are imported from the roots via the xylem stream or are synthesised in situ in the buds, but CKs may be part of an endogenous signal involved in lateral bud growth stimulation following shoot decapitation. To our knowledge, this is the first detailed report of CK levels in buds themselves during release of apical dominance.
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Purpose: A gap of more than a hundred years occurred between the first accounts of mesial temporal sclerosis and recognition of its role in the pathogenesis of psychomotor seizures. This paper reviews how the understanding and surgical treatment of temporal lobe epilepsy developed, particularly from the work of Penfield, Jasper, and their associates at the Montreal Neurological Institute (MNI). Methods: Publications on EEG and surgery for temporal lobe seizures from 1935 to 1953 were reviewed and charts of selected patients operated on at the MNI in the same period were examined. Attention was focused on the evolution of surgical techniques for temporal lobe epilepsy. Results: In the late 1930s, some EEG findings suggested deep-lying disturbances originating in the temporal lobe. However, it took another two decades before the correlation of clinical, neurophysiological, and anatomical findings provided evidence for the involvement of the mesial structures in psychomotor or temporal lobe seizures. From 1949 and onward, Penfield and his associates applied this evidence to extend the surgical resections to include the uncus and the hippocampus. Conclusion: The collaborative work of a team led by Penfield and Jasper at the MNI helped to define the role of neurophysiological studies in epilepsy surgery. As a result, the importance of removing the mesial structures in order to obtain better seizure control in patients with temporal lobe epilepsy became firmly established.
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OBJECTIVE: A new nerve transfer technique using a healthy fascicle of the posterior cord for suprascapular nerve reconstruction is presented. This technique was used in a patient with posttraumatic brachial plexopathy resulting in upper trunk injury with proximal root stumps that were unavailable for grafting associated with multiple nerve dysfunction. CLINICAL PRESENTATION: A 45-year-old man sustained a right brachial plexus injury after a bicycle accident. Clinical evaluation and electromyography indicated upper trunk involvement. Trapezius muscle function and triceps strength were normal on physical examination. INTERVENTION: The patient underwent a combined supra- and infraclavicular approach to the brachial plexus. A neuroma-in-continuity of the upper trunk and fibrotic C5 and C6 roots were identified. Electrical stimulation of the phrenic and spinal accessory nerves produced no response. The suprascapular nerve was dissected from the upper trunk, transected, and rerouted to the infraclavicular fossa. A healthy fascicle of the posterior cord to the triceps muscle was transferred to the suprascapular nerve. At the time of the 1-year follow-up evaluation, arm abduction against gravity and external rotation reached 40 and 34 degrees, respectively. CONCLUSION: The posterior cord can be used as a source of donor fascicle to the suprascapular nerve after its infraclavicular relocation. This new intraplexal nerve transfer could be applied in patients with isolated injury of the upper trunk and concomitant lesion of the extraplexal nerve donors usually used for reinnervation of the suprascapular nerve.
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Objective: The purpose of this study was to investigate the reliability and validity of photogrammetry in measuring the lateral spinal inclination angles. Methods: Forty subjects (32 female and 8 males) with a mean age of 23.4 +/- 11.2 years had their scoliosis evaluated by radiographs of their trunk, determined by the Cobb angle method, and by photogrammetry. The statistical methods used included Cronbach alpha, Pearson/Spearman correlation coefficients, and regression analyses. Results: The Cronbach a values showed that the photogrammetric measures showed high internal consistency, which indicated that the sample was bias free. The radiograph method showed to be more precise with intrarater reliabilities of 0.936, 0.975, and 0.945 for the thoracic, lumbar, and thoracolumbar curves, respectively, and interrater reliabilities of 0.942 and 0.879 for the angular measures of the thoracic and thoracolumbar segments, respectively. The regression analyses revealed a high determination coefficient although limited to the adjusted linear model between the radiographic and photographic measures. It was found that with more severe scoliosis, the lateral curve measures obtained with the photogrammetry were for the thoracic and lumbar regions (R = 0.619 and 0.551). Conclusions: The photogrammetric measures were found to be reproducible in this study and could be used as Supplementary information to decrease the number of radiographs necessary for the monitoring of scoliosis. (J Manipulative Physiol Ther 2009;32:423-430)
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Purpose: To evaluate the use of orbital polyacrylamide gel injection for the correction of anophthalmic enophthalmos. Methods: Noncontrolled clinical trial of 21 patients (14 with ocular implants, 5 with phthisis bulbi, and 2 with dermis-fat graft). Orbital CT was performed to estimate the volume of polyacrylamide gel needed to restore orbital volume. Polyacrylamide gel was injected using a 22-gauge (30 x 0.7 min) needle transcutaneously inserted in the lateral third of the lower eyelid, directed to the orbital muscle cone. A second injection was administered 15 days later. if necessary. CT was repeated 30 days after the last procedure. Exophthalmometry was performed before Bind 90 days after file procedure. Results: The mean total volume injected per orbit was 2.4 +/- 0.7 ml (range 1-3.5 ml). The volume of the enophthalmic orbit increased front 26.9 +/- 5.0 ml to 29.3 +/- 4.9 ml (p < 0.001). The mean difference in exophthalmometry readings was 3.3 +/- 1.6 mm (range, 1.5-8.0 mm) before the procedure and 1.0 +/- 0.9 mm (range, 0.0-3.0 mm) after 3 months (p < 0.001). Adjustment of the ocular prosthesis or fabrication of a new one was necessary in 11 patients (52.4%), and the mean volume of the ocular prosthesis was reduced front 2.0 +/- 0.6 ml to 1.6 +/- 0.6 ml (p = 0.003). All patients were satisfied with the aesthetic results. No serious adverse events were observed. The initial results were maintained 1 year after the procedure. Conclusions: Polyacrylamide gel injection in the orbital space effectively reduces enophthalmos in ocular prosthesis wearers.
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OBJECTIVE: To study the microanatomy of the brainstem related to the different safe entry zones used to approach intrinsic brainstem lesions. METHODS: Ten formalin-fixed and frozen brainstem specimens (20 sides) were analyzed. The white fiber dissection technique was used to study the intrinsic microsurgical anatomy as related to safe entry zones on the brainstem surface. Three anatomic landmarks on the anterolateral brainstem surface were selected: lateral mesencephalic sulcus, peritrigeminal area, and olivary body. Ten other specimens were used to study the axial sections of the inferior olivary nucleus. The clinical application of these anatomic nuances is presented. RESULTS: The lateral mesencephalic sulcus has a length of 7.4 to 13.3 mm (mean, 9.6 mm) and can be dissected safely in depths up to 4.9 to 11.7 mm (mean, 8.02 mm). In the peritrigeminal area, the distance of the fifth cranial nerve to the pyramidal tract is 3.1 to 5.7 mm (mean, 4.64 mm). The dissection may be performed 9.5 to 13.1 mm (mean, 11.2 mm) deeper, to the nucleus of the fifth cranial nerve. The inferior olivary nucleus provides safe access to lesions located up to 4.7 to 6.9 mm (mean, 5.52 mm) in the anterolateral aspect of the medulla. Clinical results confirm that these entry zones constitute surgical routes through which the brainstem may be safely approached. CONCLUSION: The white fiber dissection technique is a valuable tool for understanding the three-dimensional disposition of the anatomic structures. The lateral mesencephalic sulcus, the peritrigeminal area, and the inferior olivary nucleus provide surgical spaces and delineate the relatively safe alleys where the brainstem can be approached without injuring important neural structures.
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Objective. The purpose of this series was to determine the frequency of abductor mechanism avulsion by sonography after total hip arthroplasty with the Hardinge approach (J Bone Joint Surg Br 1982; 64:17-19) and its relationship to the presence of insufficiency of this musculature in the postoperative period. Methods. Thirty-four consecutive patients were prospectively accessed in the postoperative period of hip arthroplasty by the Trendelenburg test, hip sonography, and abductor muscle electromyography. In patients who were found to have clinical insufficiency of the abductor musculature, we also measured the femoral offset in the preoperative and postoperative radiographs. Hip sonography was performed by an experienced musculoskeletal radiologist blinded to the other tests, and the tendons of the gluteus medius and gluteus minimus were visualized on longitudinal and transverse sections with a 7- to 10-MHz linear transducer. Results. Eight patients presented clinical insufficiency of the abductor musculature as detected by the Trendelenburg test. Four of these 8 patients with abductor insufficiency presented tendinous avulsion detected by sonography. One of the 4 patients with abductor insufficiency and normal sonographic findings had a decrease in the femoral offset caused by the arthroplasty itself. Two patients presented electromyographic changes of the abductor musculature, with no tendinous avulsion detected by sonography and no abductor insufficiency. Conclusions. We concluded that in patients undergoing total hip arthroplasty by the Hardinge approach in whom insufficiency of the abductor musculature develops, sonography is an interesting method of investigation because it identified the cause of this problem in most of our patients.
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The present study aimed to assess the reliability of intra and inter-examiner subacromial impingement index (SII) measures obtained from radiographs. Thirty-six individuals were enrolled and divided into two groups: control group, composed of 18 volunteers in good general health without shoulder problems, and a group of 18 patients with subacromial impingement syndrome (SIS). Radiographic images were taken with the dominant upper limb in neutral rotation, while the volunteers held their arm at 90A degrees of abduction in the frontal plane. The beam of radiation at 30A degrees craniocaudal inclination was used to provide an antero-posterior image view. Three blinded examiners each performed three measurements from the subacromial space (SS) and the anatomical neck of the humerus (NH). The SII was calculated as the ratio of the SS and the NH measures. The mean values of SII were compared using t-tests. The intra-class correlation coefficient (ICC) was used to assess intra- and inter-examiner reliability of the measures. The mean values of SII were greater for the control group (0.12) than for the SIS group (0.08; p = 0.0071). SII measurements showed excellent intra (0.96-0.99) and inter-examiner reliability (0.94) for both the control and SIS group. The results of this study show the potential use of the SII; a greater mean value for the control group compared to the SIS group and excellent reliability for intra- and inter-examiner measurement. Validation studies of the index should be conducted to correlate the index with clinical findings from subacromial impingement syndrome.
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The paraventricular nucleus of the hypothalamus (PVN) has been implicated in several aspects of cardiovascular control. Stimulation of the PVN evokes changes in blood pressure and heart rate. Additionally, this brain area is connected to several limbic structures implicated in behavioral control, as well as to forebrain and brainstem structures involved in cardiovascular control. This evidence indicates that the PVN may modulate cardiovascular correlates of behavioral responses to stressful stimuli. Acute restraint is an unavoidable stressor that evokes marked and sustained cardiovascular changes, which are characterized by elevated mean arterial pressure (MAP) and an intense heart rate (HR) increase. We report on the effect of inhibition of PVN synapses on MAP and HR responses evoked by acute restraint in rats. Bilateral microinjection of the nonspecific synaptic blocker cobalt (CoCl2, 1mM/100nl) into the PVN did not change the HR response or the initial peak of the MAP response to restraint stress, but reduced the area under the curve of the MAP response. Moreover, bilateral microinjection of cobalt in areas surrounding the PVN did not change the cardiovascular response to restraint. These results indicate that synapses in the PVN are involved in the neural pathway that controls blood pressure changes evoked by restraint.