931 resultados para Lateral sizes
Resumo:
There is growing interest in understanding the role of the non-injured contra-lateral hemisphere in stroke recovery. In the experimental field, histological evidence has been reported that structural changes occur in the contra-lateral connectivity and circuits during stroke recovery. In humans, some recent imaging studies indicated that contra-lateral sub-cortical pathways and functional and structural cortical networks are remodeling, after stroke. Structural changes in the contra-lateral networks, however, have never been correlated to clinical recovery in patients. To determine the importance of the contra-lateral structural changes in post-stroke recovery, we selected a population of patients with motor deficits after stroke affecting the motor cortex and/or sub-cortical motor white matter. We explored i) the presence of Generalized Fractional Anisotropy (GFA) changes indicating structural alterations in the motor network of patientsâeuro? contra-lateral hemisphere as well as their longitudinal evolution ii) the correlation of GFA changes with patientsâeuro? clinical scores, stroke size and demographics data iii) and a predictive model.
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Skeletal muscle mitochondrial (Mito) and lipid droplet (Lipid) content are often measured in human translational studies. Stereological point counting allows computing Mito and Lipid volume density (Vd) from micrographs taken with transmission electron microscopes. Former studies are not specific as to the size of individual squares that make up the grids, making reproducibility difficult, particularly when different magnifications are used. Our objective was to determine which size grid would be best at predicting fractional volume efficiently without sacrificing reliability and to test a novel method to reduce sampling bias. Methods: ten subjects underwent vastus lateralis biopsies. Samples were fixed, embedded, and cut longitudinally in ultrathin sections of 60 nm. Twenty micrographs from the intramyofibrillar region were taken per subject at Ã-33,000 magnification. Different grid sizes were superimposed on each micrograph: 1,000 Ã- 1,000 nm, 500 Ã- 500 nm, and 250 Ã- 250 nm. Results: mean Mito and Lipid Vd were not statistically different across grids. Variability was greater when going from 1,000 Ã- 1,000 to 500 Ã- 500 nm grid than from 500 Ã- 500 to 250 Ã- 250 nm grid. Discussion: this study is the first to attempt to standardize grid size while keeping with the conventional stereology principles. This is all in hopes of producing replicable assessments that can be obtained universally across different studies looking at human skeletal muscle mitochondrial and lipid droplet content.
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The morphology and distribution of local-circuit neurons (interneurons) were examined, by calbindin D-28k and parvalbumin immunocytochemistry, in the frontal cortex (area 8) in two patients with frontal lobe dementia of non-Alzheimer type associated with classical amyotrophic lateral sclerosis (ALS), and in seven normal cases. The density of calbindin D-28k immunoreactive cells was dramatically reduced in ALS patients, but the density of parvalbumin-immunoreactive neurons was preserved. Decreased density of calbindin D-28k-immunoreactive neurons, which are mainly located in the upper cortical layers, may interfere with the normal processing of cortico-cortical connections, whereas integrity of parvalbumin-immunoreactive cells may be associated with the preservation of the major inhibitory intracortical circuits in patients with frontal lobe dementia.
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Amyotrophic lateral sclerosis (ALS) is predominantly characterized by a progressive loss of motor function. While autonomic dysfunction has been described in ALS, little is known about the prevalence of lower urinary tract symptoms (LUTS) and intestinal dysfunction. We investigated disease severity, LUTS and intestinal dysfunction in 43 patients with ALS attending our outpatient department applying the ALS functional rating scale, the International Consultation on Incontinence Modular Questionnaire, the Urinary Distress Inventory and the Cleveland Clinic Incontinence Score. Results were compared to the German population of a cross-sectional study assessing LUTS in the healthy population, the EPIC study. Results showed that urinary incontinence was increased in patients with ALS aged ≥ 60 years compared to the EPIC cohort (female: 50%/19% (ALS/EPIC), p = 0.026; male: 36%/11% (ALS/EPIC), p = 0.002). No difference was seen at 40-59 years of age. Urge incontinence was the predominant presentation (73% of symptoms). A high symptom burden was stated (ICIQ-SF quality of life subscore 5.5/10). Intake of muscle relaxants and anticholinergics was associated with both urinary incontinence and severity of symptoms. Furthermore, a high prevalence of constipation (46%), but not stool incontinence (9%), was noted. In conclusion, the increased prevalence of urge incontinence and high symptom burden imply that in patients with ALS, LUTS should be increasingly investigated for.
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Excessive speed is often cited as a primary driver factor in crashes, particularly rural two-lane crashes. It has also been suggested that speed plays a significant role in crashes on curves. However, the relationship between speed and crashes on curves is not well documented because it is difficult to determine driver speed after the fact when investigating a crash. One method to begin documenting this relationship is to explore the relationship between lateral position and speed as a crash surrogate. For this study, the researchers collected speed and lateral position data for three rural two-lane curves. The relationship between lateral position and speed was assessed by comparing the odds of a near-lane crossing for vehicles traveling 5 or more mph over the advisory speed to those for vehicles traveling below that threshold.
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Collective evidence indicates that motor neuron degeneration in amyotrophic lateral sclerosis (ALS) is non-cell-autonomous and requires the interaction with the neighboring astrocytes. Recently, we reported that a subpopulation of spinal cord astrocytes degenerates in the microenvironment of motor neurons in the hSOD1(G93A) mouse model of ALS. Mechanistic studies in vitro identified a role for the excitatory amino acid glutamate in the gliodegenerative process via the activation of its inositol 1,4,5-triphosphate (IP(3))-generating metabotropic receptor 5 (mGluR5). Since non-physiological formation of IP(3) can prompt IP(3) receptor (IP(3)R)-mediated Ca(2+) release from the intracellular stores and trigger various forms of cell death, here we investigated the intracellular Ca(2+) signaling that occurs downstream of mGluR5 in hSOD1(G93A)-expressing astrocytes. Contrary to wild-type cells, stimulation of mGluR5 causes aberrant and persistent elevations of intracellular Ca(2+) concentrations ([Ca(2+)](i)) in the absence of spontaneous oscillations. The interaction of IP(3)Rs with the anti-apoptotic protein Bcl-X(L) was previously described to prevent cell death by modulating intracellular Ca(2+) signals. In mutant SOD1-expressing astrocytes, we found that the sole BH4 domain of Bcl-X(L), fused to the protein transduction domain of the HIV-1 TAT protein (TAT-BH4), is sufficient to restore sustained Ca(2+) oscillations and cell death resistance. Furthermore, chronic treatment of hSOD1(G93A) mice with the TAT-BH4 peptide reduces focal degeneration of astrocytes, slightly delays the onset of the disease and improves both motor performance and animal lifespan. Our results point at TAT-BH4 as a novel glioprotective agent with a therapeutic potential for ALS.
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The authors report a case of repetitive locking knee caused by a subluxation of the posterior horn of a normal lateral meniscus. The posterior horn was sutured to the posterior knee capsule and the athlete resumed complete sports activity 4 months after the surgery.
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Each year several prestressed concrete girder bridges in Iowa and other states are struck and damaged by vehicles with loads too high to pass under the bridge. Whether or not intermediate diaphragms play a significant role in reducing the effect of these unusual loading conditions has often been a topic of discussion. A study of the effects of the type and location of intermediate diaphragms in prestressed concrete girder bridges when the bridge girder flanges were subjected to various levels of vertical and horizontal loading was undertaken. The purpose of the research was to determine whether steel diaphragms of any conventional configuration can provide adequate protection to minimize the damage to prestressed concrete girders caused by lateral loads, similar to the protection provided by the reinforced concrete intermediate diaphragms presently being used by the Iowa Department of Transportation. The research program conducted and described in this report included the following: A comprehensive literature search and survey questionnaire were undertaken to define the state-of-the-art in the use of intermediate diaphragms in prestressed concrete girder bridges. A full scale, simple span, restressed concrete girder bridge model, containing three beams was constructed and tested with several types of intermediate diaphragms located at the one-third points of the span or at the mid-span. Analytical studies involving a three-dimensional finite element analysis model were used to provide additional information on the behavior of the experimental bridge. The performance of the bridge with no intermediate diaphragms was quite different than that with intermediate diaphragms in place. All intermediate diaphragms tested had some effect in distributing the loads to the slab and other girders, although some diaphragm types performed better than others. The research conducted has indicated that the replacement of the reinforced concrete intermediate diaphragms currently being used in Iowa with structural steel diaphragms may be possible.
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Objective: To assess the impact of patient admission in different hospital types in Switzerland on early in-hospital and 1-year outcomes in patients with acute coronary syndrome (ACS).Methods: From 1997 to 2009, 31,010 ACS patients from 76 Swiss hospitals were enrolled in the AMIS Plus registry. Large tertiary teaching institutions with 24 hour/7 day cardiac catheterization facilities were classified as type A hospitals, all others as type B. One-year outcome was studied in a subgroup of patients admitted after 2005. Multivariate logistic regression models were used to calculate the odds ratios (OR with 95%CI) for independent predictors of mortality and major adverse cardiac events (MACE).Results: There were 11 type A hospitals with admissions of 15,987 (52%) patients and 65 type B hospitals with 15,023 (48%) patients. Patients initially admitted into B hospitals were older, more frequently female, hypertensive and diabetic, had more severe comorbidities and more frequently NSTE-ACS/UA. They were less likely to receive aspirin, clopidogrel and GPIIb/IIIa antagonists. STE-ACS patients initially admitted into B hospitals received more thrombolysis than those admitted into A hospitals, but less percutaneous coronary intervention (PCI). From the patients admitted to B hospitals, 5271 (35%) were transferred for intervention. Crude in-hospital mortality and MACE were higher in patients from B hospitals. Crude 1-year mortality of 3747 ACS patients followed up was higher in patients initially admitted into B hospitals, but no differences were found for MACE. Hospital type, after adjustment for age, risk factors, type of ACS and co-morbidities, was not an independent predictor of in-hospital mortality (OR 0.94; 0.76-1.16), in-hospital MACE (0.98; 0.82-1.17), 1-year mortality or 1-year MACE (1.06; 0.85-1.33). Analysis of the time of admission indicated a crude outcome in favor of hospitalization during duty-hours but no significant effect could be documented for 1-year outcome.Conclusion: ACS patients admitted to type B hospitals were older, had more severe co-morbidities, more NSTEACS and received less intensive treatment. However, after correcting for baseline inequalities, early and mid-term outcomes were similar regardless of hospital type. Ultimate patient outcome thus does not appear to be influenced by the type of hospital where the initial admission takes place. Appropriate early referral of selected patients probably partly explains this finding.
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Introduction: Primary bone sarcomas around the ankle are rare. Due to the proximity of neurovascular structures and limited soft tissue reserves, limb salvage is often not possible. Case report: A 19 yo male presented with pain and a progressive swelling of his ankle. X-rays revealed cortical erosions and an extensive periosteal reaction (sunburst) of the distal fibula. MRI showed a large mass of the fibula invading adjacent soft tissue. The lesion appeared close to the ankle joint, but with the articular cartilage as a barrier and without joint effusion. Core-needle biopsy revealed a high-grade chondroblastic osteosarcoma. No metastases were detected. After presentation at our multidisciplinary sarcoma board, the patient was subjected to neo-adjuvant chemotherapy (AOST 03-331). Without any sign of intra-articular contamination of the ankle joint, surgical treatment consisted of wide resection of the lateral malleolus including a large skin patch, the distal third of the fibula, the lateral surfaces of the tibia and talus as well as the insertion of the lateral ligament on the calcaneus. The distal parts of the anterior, peroneal, and posterior muscular compartments were resected en bloc with the tumor. The defect was reconstructed with tibio-talar and talo-calcanear fusion, bony allograft and a plate. Soft-tissue coverage was achieved with a free fascio-cutaneous flap from the controlateral thigh. Histological analysis revealed clear margins and 50% of tumor necrosis. The oncologic treatment was completed with adjuvant chemotherapy. Conclusion: Wide resection and reconstruction of the lateral malleolus is technically demanding but possible in selected cases. Despite some important functional loss, limb salvage is superior to an amputation.
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Visando ao estudo do uso de bordadura lateral em experimentos de avaliação de genótipos de milho-verde, testaram-se quatro arranjos para pré-especificar a disposição das linhas na parcela experimental básica. No arranjo 1, o estudo foi feito de forma que os efeitos convergissem para o centro da parcela. No arranjo 2, têm-se informações do efeito de bordadura de cada lado da parcela. No arranjo 3, as informações são obtidas em cada linha da parcela, e no arranjo 4, têm-se informações das linhas de cada lado da parcela em relação à parte central. Os dados utilizados foram provenientes de um ensaio de avaliação de 20 genótipos de milho-verde, coletados separadamente em cada linha da parcela, permitindo-se, desta maneira, utilizar o esquema de parcelas subdivididas. Os resultados obtidos possibilitam recomendar os arranjos 1 ou 2 para o estudo de bordadura lateral. Com relação à cultura de milho-verde, verificou-se que há necessidade de duas fileiras de bordadura lateral de cada lado da parcela.
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Aeromonas hydrophila AH-3 lateral flagella are not assembled when bacteria grow in liquid media; however, lateral flagellar genes are transcribed. Our results indicate that A. hydrophila lateral flagellar genes are transcribed at three levels (class I to III genes) and share some similarities with, but have many important differences from, genes of Vibrio parahaemolyticus. A. hydrophila lateral flagellum class I gene transcription is σ70 dependent, which is consistent with the fact that lateral flagellum is constitutively transcribed, in contrast to the characteristics of V. parahaemolyticus. The fact that multiple genes are included in class I highlights that lateral flagellar genes are less hierarchically transcribed than polar flagellum genes. The A. hydrophila lafK-fliEJL gene cluster (where the subscript L distinguishes genes for lateral flagella from those for polar flagella) is exclusively from class I and is in V. parahaemolyticus class I and II. Furthermore, the A. hydrophila flgAMNL cluster is not transcribed from the σ54/LafK-dependent promoter and does not contain class II genes. Here, we propose a gene transcriptional hierarchy for the A. hydrophila lateral flagella.
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Death of sensory hair cells in the inner ear results in two global health problems that millions of people around the world suffer: hearing loss and balance disorders. Hair cells convert sound vibrations and head movements into electrical signals that are conveyed to the brain, and as a result of aging, exposure to noise, modern drugs or genetic predisposition, hair cells die. In mammals, the great majority of hair cells are produced during embryogenesis, and hair cells that are lost after birth are not replaceable. However, in the last decades, researches have shown some model organisms that retain the ability to regenerate hair cells damaged after embryogenesis, such as Zebrafish and chicken, providing clues as to the cellular and molecular mechanisms that may block hair cell regeneration in mammals. This discovery initiated a search for methods to stimulate regeneration or replacement of hair cells in mammals, a search that, if fruitful, will revolutionize the treatment of hearing loss and balance disorders. One aim of my project is to study the role of retinoic acid in adult Zebrafish and in mice, which is a metabolite of vitamin A known as an essential molecule to activate hair cell regeneration after cells damaged in Zebrafish embryo. We want to study important genes involved in retinoic acid pathway, such as Aldh1a3 and RARs genes, to check what their role is in the inner ear of adult Zebrafish and compare result obtained in the inner ear of mice. On the other hand, Zebrafish lateral line contains neuromast, which are formed by the same structure than the inner ear: hair cells surrounded by supporting cells and neurons. The lateral line is a structure below the skin's surface that makes easier to damage hair cells to study their regeneration. For that reason, another aim of my project is to study how Sox2 and Atoh1, essential genes during the inner ear development, change their expression during hair cell regeneration in the lateral line. In my project, the most important concepts related to Zebrafish world are explained in order to understand why we have studied this animal and these essential genes. Then, techniques that we used are explained, with their protocol attached in the annexes. Finally, results of my project are shown, but many of them were not expected and they would be needed to follow studying.