995 resultados para Callus formation


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Objective: To describe the prolonged rehabilitation program for a Jones fracture in a Division I-A American football player. Background: A 21 year old, African American, collegiate football player (body mass= 264 lb; height= 76.5 in; body fat= 16.0%) complained of a sharp pain at the dorsal aspect of the left foot. The athlete experiences a compressive force to the fifth metatarsal and upon evaluation, mild swelling was present along the lateral aspect of the foot. Differential Diagnosis: Jones fracture, metatarsal fracture, bone contusion. Treatment: An intramedullary fixation surgery was scheduled two weeks post injury, to correct and stabilize the fracture. Intramedullary fixation is a method of mending the bone internally with a screw, wire, or metal plate along the fractured bone length wise. Following surgery the athlete continued use of crutches for ambulation and was placed in a removable walking boot for 5 weeks. Uniqueness: This case presented a unique challenge in the rehabilitation program, as the athlete experienced slow formation of the bone callus and therefore a prolonged rate of recovery. The athlete was in a walking boot longer than expected (2 weeks longer than anticipated) which inhibited advancement in his rehabilitation due to a slow bone callus formation. A soft callus usually begins to form at day 5 following injury, but documentation was incomplete, and a hypothesis for slow bone callus formation could be secondary to lengthened time between injury occurrence and injury reporting. The athlete may have been weight bearing during the early callus formation, but healing may have been prohibited. Also, vascularization in the area is already limited and may also have played a role in delayed bone growth. Conclusions: Although the return to participation was longer than expected, the rehabilitation program was successful in returning the athlete to competition.

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The most native fruit trees are belonging to Myrtaceae family, which it have as main marketing potential their fruit. Despite the wide acceptance of the fruits of these native fruit cultura, the establishment of commercial orchards is still necessary, because if it prevails extraction in the forest. To start the cultivo in the orchard, the first point is on the mother plant choice, which should provide superior characteristics when compared to other genotypes. Then, it is necessary to choose the method to can produce satisfactory amount of seedlings and preferably without it to lose the mother plant characteristics. For this, it adopts the asexual thechniques, with option for grafting, cuttings and air layering. These techniques when tested with native fruits tree, it proved limiting in theses results, with this, it should to test other it to recommend its use, especially, those fruit native of higher potential as jabuticaba tree, pitanga tree, sete capote tree and araça amarelo tree. The aim of this study was to test the use of asexual propagation through mini-cuttings in these native fruit trees, according to the time of collection, the mini-cutting length and concentration of IBA, as well as, it to relate the results of rooting with tryptophan extracted at certain times. The work was carried out at Universidade Tecnológica Federal do Paraná – Câmpus Dois Vizinhos, Brazil. The samples were collected each two months. The mini-cutting were prepared with 6 or 8 cm, with a pair of leaves reduced to 25% of the original size. The mini-cuttings had their base immersed in liquid solution of indole-butyric acid (IBA) in the concentrations of 0, 3000 and 6000 mg L-1 and then were placed in tubes containing commercial substrate. The experimental design was completely randomized with factorial 2 x 3 x 6 (mini-cutting length x IBA concentration x time of collection), with four replications, it being each plot varied according to the amount of shoots obtained by period time. After 120 days, the rooting and callus formation (%), average number of roots per mini-cutting and the average length of the roots were evaluated. After 60 days of these evaluations, the survival of mini-cuttings rooted after transplant was evaluated. It was evaluated also the production of mini-cuttings of each size in each period time. At the end of the experiment it was evaluated the percentage of survival of mother plantlets. For analysis of tryptophan was used materials branches, leaves and twigs with leaves, taken from the materials used for the production of mini-cutting. It was recommended for hybrid jabuticaba tree the use mini-cutting with eight cm, treated with 6000 mg L-1 of IBA and collected in June. For jabuticaba tree of cabinho and araça amarelo tree the period for propagation by mini-cuttings should be in August, regardless of IBA concentration and length of the mini-cutting. In the jabuticaba tree sabara and sete capote tree is important to obtain more satisfactory results realized the collect in October or December, with the same independence of other levels tested in other factors. However, for sete capote tree should test other techniques to increase the efficiency of propagation. And with pitanga tree recommended to the collection in June, but with 6cm the application of 3000 mg L-1 of IBA and 8 cm with 6000 mg L-1 of IBA.

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Introducción El motivo principal por el que acuden los pacientes a las consultas de podología es el dolor producido por los callos y callosidades plantares. El dolor producido por las callosidades y callos plantares provocan en el paciente cambios de presiones y alteraciones en el apoyo, dificultando la deambulación correcta. Existen numerosos estudios sobre la eliminación de callosidades en pacientes diabéticos, con AR, pero pocos en personas sanas. La eliminación de estos callos y callosidades se puede realizar mediante deslaminación mecánica con bisturí o mediante queratolíticos. Objetivos Objetivo principal Analizar el efecto de la deslaminación mecánica con bisturí de las callosidades y callos plantares sobre el dolor y la calidad de vida en sujetos sanos Objetivos secundarios Determinar la existencia de modificaciones en los parámetros de la marcha con la eliminación de callosidades y callos plantares Observar las diferencias y efectividad de tratamientos de la eliminación de callosidades plantares mediante la técnica de deslaminación mecánica con bisturí versus parches de ácido salicílico Comprobar los cambios producidos en los parámetros psíquicos y fiscos del paciente antes y después de las diferentes técnicas de eliminación de las callosidades empleadas Método Se realizan dos estudios: un estudio cuasi experimental aleatorizado no controlado, en el que a un grupo de 34 pacientes con callosidades plantares dolorosas se les mide el dolor con una escala visual analógica y para analizar los parámetros de la marcha, la paltaformaWin-Track, antes del tratamiento de deslaminación mecánica con bisturí y a las 24 horas. El segundo estudio es un ensayo clínico aleatorizado inscrito en Australian New ZelandClinicalstrials y aprobado por el Comité ético de la Universidad de Málaga, en el que 62 participantes con callosidades plantares dolorosas se dividieron en dos grupos de tratamiento. El grupo A recibió tratamiento con parche de ácido salicílico y el grupo B recibió tratmiento de deslaminación con bisturí. Se utilizó la escala visual analógica para la medida de dolor antes, inmediatamente después de la intervención, a las 2 semanas y a las 6 semanas. Para el dolor y la discapacidad funcional del pie se utilizó el cuestionario Manchester FootPain and Disability antes del tratamiento, a las 2 semanas y a las 6 semanas. Para medir la calidad de vida general se utilizó el cuestionario SF-12 Conclusiones La deslaminación mecánica con bisturí de los callos y callosidades plantares es efectiva para su eliminación a nivel de la sensación de dolor, aunque no tanto en lo que se refiere a la mejora de calidad de vida. No hay resultados significativos de que la eliminación mecánica con bisturí de callos y callosidades plantares modifican los parámetros de la marcha medido con la plataforma Win-track. Se observa como la deslaminación mecánica con bisturí para la eliminación de callos y callosidades plantares pueden ser más efectiva a corto plazo que la eliminación mediante parche con ácido salicílico. Se observa cómo se modifica los paramentos psíquicos en el grupo de tratamiento con parche con ácido salicílico, aunque con una significación baja. Bibliografía Balanowski, K. R., & Flynn, L. M. (2005). Effect of painful keratoses debridement on foot pain, balance and function in older adults. Gait & Posture, 22(4), 302-307. http://doi.org/10.1016/j.gaitpost.2004.10.006 Collins, S. L., Moore, R. A., &McQuay, H. J. (1997). The visual analogue pain intensity scale: what is moderate pain in millimetres? Pain, 72(1-2), 95-97. Coughlin, M. J. (2000).Common Causes of Pain in the Forefoot in Adults. Journal of Bone & Joint Surgery, British Volume, 82-B(6), 781-790. Farndon, L. J., Vernon, W., Walters, S. J., Dixon, S., Bradburn, M., Concannon, M., & Potter, J. (2013). The effectiveness of salicylic acid plasters compared with «usual» scalpel debridement of corns: a randomised controlled trial. Journal of Foot and Ankle Research, 6(1), 40. http://doi.org/10.1186/1757-1146-6-40 Freeman, D. B. (2002). Corns and calluses resulting from mechanical hyperkeratosis. American FamilyPhysician, 65(11), 2277-2280. Gijon-Nogueron, G., Ndosi, M., Luque-Suarez, A., Alcacer-Pitarch, B., Munuera, P. V., Garrow, A., & Redmond, A. C. (2014). Cross-cultural adaptation and validation of the Manchester Foot Pain and Disability Index into Spanish. Quality of Life Research: An International Journal of Quality of Life Aspects of Treatment, Care and Rehabilitation, 23(2), 571-579. http://doi.org/10.1007/s11136-013-0507-5 Grouios, G. (2005). Footedness as a potential factor that contributes to the causation of corn and callus formation in lower extremities of physically active individuals. The Foot, 15(3), 154-162. http://doi.org/10.1016/j.foot.2005.05.003 Landorf, K. B., Morrow, A., Spink, M. J., Nash, C. L., Novak, A., Potter, J., &Menz, H. B. (2013). Effectiveness of scalpel debridement for painful plantar calluses in older people: a randomized trial. Trials, 14, 243. http://doi.org/10.1186/1745-6215-14-243 Lang, L. M. G., Simmonite, N., West, S. G., & Day, S. (1994). Salicylic acid in the treatment of corns. The Foot, 4(3), 145-150. http://doi.org/10.1016/0958-2592(94)90019-1 Luo, X., Lynn George, M., Kakouras, I., Edwards, C. L., Pietrobon, R., Richardson, W., & Hey, L. (2003). Reliability, validity, and responsiveness of the short form 12-item survey (SF-12) in patients with back pain. Spine, 28(15), 1739-1745. http://doi.org/10.1097/01.BRS.0000083169.58671.96 Ramachandra, P., Maiya, A. G., & Kumar, P. (2012). Test-retest reliability of the Win-Track platform in analyzing the gait parameters and plantar pressures during barefoot walking in healthy adults. Foot & Ankle Specialist, 5(5), 306-312. http://doi.org/10.1177/1938640012457680 Siddle, H. J., Redmond, A. C., Waxman, R., Dagg, A. R., Alcacer-Pitarch, B., Wilkins, R. A., &Helliwell, P. S. (2013). Debridement of painful forefoot plantar callosities in rheumatoid arthritis: the CARROT randomised controlled trial. Clinical Rheumatology, 32(5), 567-574. http://doi.org/10.1007/s10067-012-2134-x

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After bone fracture, various cellular activities lead to the formation of different tissue types, which form the basis for the process of secondary bone healing. Although these tissues have been quantified by histology, their material properties are not well understood. Thus, the aim of this study is to correlate the spatial and temporal variations in the mineral content and the nanoindentation modulus of the callus formed via intramembranous ossification over the course of bone healing. Midshaft tibial samples from a sheep osteotomy model at time points of 2, 3, 6 and 9 weeks were employed. PMMA embedded blocks were used for quantitative back scattered electron imaging and nanoindentation of the newly formed periosteal callus near the cortex. The resulting indentation modulus maps show the heterogeneity in the modulus in the selected regions of the callus. The indentation modulus of the embedded callus is about 6 GPa at the early stage. At later stages of mineralization, the average indentation modulus reaches 14 GPa. There is a slight decrease in average indentation modulus in regions distant to the cortex, probably due to remodelling of the peripheral callus. The spatial and temporal distribution of mineral content in the callus tissue also illustrates the ongoing remodelling process observed from histological analysis. Most interestingly the average indentation modulus, even at 9 weeks, remains as low as 13 GPa, which is roughly 60% of that for cortical sheep bone. The decreased indentation modulus in the callus compared to cortex is due to the lower average mineral content and may be perhaps also due to the properties of the organic matrix which might be different from normal bone.

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Iterative computational models have been used to investigate the regulation of bone fracture healing by local mechanical conditions. Although their predictions replicate some mechanical responses and histological features, they do not typically reproduce the predominantly radial hard callus growth pattern observed in larger mammals. We hypothesised that this discrepancy results from an artefact of the models’ initial geometry. Using axisymmetric finite element models, we demonstrated that pre-defining a field of soft tissue in which callus may develop introduces high deviatoric strains in the periosteal region adjacent to the fracture. These bone-inhibiting strains are not present when the initial soft tissue is confined to a thin periosteal layer. As observed in previous healing models, tissue differentiation algorithms regulated by deviatoric strain predicted hard callus forming remotely and growing towards the fracture. While dilatational strain regulation allowed early bone formation closer to the fracture, hard callus still formed initially over a broad area, rather than expanding over time. Modelling callus growth from a thin periosteal layer successfully predicted the initiation of hard callus growth close to the fracture site. However, these models were still susceptible to elevated deviatoric strains in the soft tissues at the edge of the hard callus. Our study highlights the importance of the initial soft tissue geometry used for finite element models of fracture healing. If this cannot be defined accurately, alternative mechanisms for the prediction of early callus development should be investigated.

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Introduction & Aims Optimising fracture treatments requires a sound understanding of relationships between stability, callus development and healing outcomes. This has been the goal of computational modelling, but discrepancies remain between simulations and experimental results. We compared healing patterns vs fixation stiffness between a novel computational callus growth model and corresponding experimental data. Hypothesis We hypothesised that callus growth is stimulated by diffusible signals, whose production is in turn regulated by mechanical conditions at the fracture site. We proposed that introducing this scheme into computational models would better replicate the observed tissue patterns and the inverse relationship between callus size and fixation stiffness. Method Finite element models of bone healing under stiff and flexible fixation were constructed, based on the parameters of a parallel rat femoral osteotomy study. An iterative procedure was implemented, to simulate the development of callus and its mechanical regulation. Tissue changes were regulated according to published mechano-biological criteria. Predictions of healing patterns were compared between standard models, with a pre-defined domain for callus development, and a novel approach, in which periosteal callus growth is driven by a diffusible signal. Production of this signal was driven by local mechanical conditions. Finally, each model’s predictions were compared to the corresponding histological data. Results Models in which healing progressed within a prescribed callus domain predicted that greater interfragmentary movements would displace early periosteal bone formation further from the fracture. This results from artificially large distortional strains predicted near the fracture edge. While experiments showed increased hard callus size under flexible fixation, this was not reflected in the standard models. Allowing the callus to grow from a thin soft tissue layer, in response to a mechanically stimulated diffusible signal, results in a callus shape and tissue distribution closer to those observed histologically. Importantly, the callus volume increased with increasing interfragmentary movement. Conclusions A novel method to incorporate callus growth into computational models of fracture healing allowed us to successfully capture the relationship between callus size and fixation stability observed in our rat experiments. This approach expands our toolkit for understanding the influence of different fixation strategies on healing outcomes.

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Time to first root in cuttings varies under different environmental conditions and understanding these differences is critical for optimizing propagation of commercial forestry species. Temperature environment (15, 25, 30 or 35 +/- A 2A degrees C) had no effect on the cellular stages in root formation of the Slash x Caribbean Pine hybrid over 16 weeks as determined by histology. Initially callus cells formed in the cortex, then tracheids developed and formed primordia leading to external roots. However, speed of development followed a growth curve with the fastest development occurring at 25A degrees C and slowest at 15A degrees C with rooting percentages at week 12 of 80 and 0% respectively. Cutting survival was good in the three cooler temperature regimes (> 80%) but reduced to 59% at 35A degrees C. Root formation appeared to be dependant on the initiation of tracheids because all un-rooted cuttings had callus tissue but no tracheids, irrespective of temperature treatment and clone.

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Time to first root in cuttings varies under different environmental conditions and understanding these differences is critical for optimizing propagation of commercial forestry species. Temperature environment (15, 25, 30 or 352C) had no effect on the cellular stages in root formation of the Slash * Caribbean Pine hybrid over 16 weeks as determined by histology. Initially callus cells formed in the cortex, then tracheids developed and formed primordia leading to external roots. However, speed of development followed a growth curve with the fastest development occurring at 25C and slowest at 15C with rooting percentages at week 12 of 80 and 0% respectively. Cutting survival was good in the three cooler temperature regimes (>80%) but reduced to 59% at 35C. Root formation appeared to be dependant on the initiation of tracheids because all un-rooted cuttings had callus tissue but no tracheids, irrespective of temperature treatment and clone.

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Vegetative propagation programs internationally are affected by the significant decline of rooting success as trees mature. This study compared the cellular stages of root formation in stem cuttings from 15-week-old (juvenile) and 9-y-old (mature) stock plants of the slash x Caribbean pine hybrid (Pinus elliottii var. elliottii x P. caribaea van hondurensis). The cellular stages of root formation were the same in both juvenile and mature cuttings, beginning with cell divisions of the vascular cambium forming callus tissue. Within the callus, tracheids differentiated and elongated to form root primordia. Roots in juvenile cuttings developed faster than those in mature cuttings and the juvenile cuttings had a much higher rooting percent at the end of the study (92% and 26% respectively). Cuttings of the two juvenile genotypes had more primary roots (5.5 and 3.3) than the three mature genotypes (0.96, 0.18 and 0.07). The roots of juvenile cuttings were more evenly distributed around the basal circumference when compared with those on cuttings from the mature genotypes. Further work is needed to improve understanding of physiological changes with maturation so that the rooting success and the speed of development in cuttings from mature stock plants can be optimised, hence improving genetic gain.

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The objective of present research was to verify the IBA and/or NAA effects with boron, on rooting of coffee (Coffea arabica L. cv 'Mundo Novo') stem cuttings. Therefore it were used stem cuttings from semi-hardwood orthotropous branches, having two nodes, with aproximately 10 cm of lenght. The cuttings were treateds during 24 hours with IBA and/or NAA plus boron solutions. The treatments' effect was observed trough the following observation, 90 days after planting: rooting percentage and number of cuttings with ''callus''. Trough the resultS obtained, it was concluded that, for obtaining more rooting of cuttings, the best treatment was NAA at 200 ppm plus boron or, the combination of IBA and NAA at 200 ppm plus boron.

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Calcium chloride concentrations from 0.0 to 12.12 mM were added to the culture medium and calcium content in calluses were determined directly by X-ray fluorescence spectrometry, a non-destructive method, allowing the processing of the same tissue for histological analysis. A multivariate statistical analysis (PCA - Principal Components Analysis) grouped the treatments into 5 blocks and indicated the most responsive group. Lack of calcium supply caused a complete absence of a morphogenic process and tissue collapse. An increase in calcium concentration gave higher total protein and sugar contents, an increase in peroxidase specific activity and changes in the histological characteristics. It was possible to verify that calcium stimulated globular somatic embryo formation at concentration of 6.62 mM.