RESUMEN
PURPOSE: Shear modulus (µ) is directly correlated to the tissue stiffness and can predict the tendon ultimate force to failure. With the knee extended 0° (K0), semitendinosus tendon (ST) is tensioned while patellar tendon (PT) is relaxed. At 80o , knee flexion (K80) tendons present an opposite stress pattern; however, the relation between ST and PT µ in both situations was not studied yet. METHOD: We accessed the µ of the ST and PT at 0o and 80o knee flexion by supersonic shear wave imaging (SSI) elastography from 18 healthy males. Relative µ indexes were calculated for relaxed and tensioned conditions. RESULT: The average µ for ST was µST-K0 = 197·62 ± 31·93 kPa and µST-K80 = 77·76 ± 30·08. For TP, values were µTP-K0 = 23·45 ± 5·89 and µTP-K80 = 113·92 ± 57·23 kPa. Relative µ indexes were calculated for relaxed (IR = µST-K80 /µTP-K0 ) and tensioned conditions (IT = µST-K0 /µPT-K80 ). The relative µ indexes were IR = 3·63 ± 1·50 and IT = 2·00 ± 0·96 (P<0·05). CONCLUSION: Semitendinosus tendon µ was significantly higher than PT µ in both tensioned and relaxed positions. This can predict a higher ultimate force to failure and a less elastic behaviour in ST grafts when compared to PT grafts. This new parameter could aid physicians in graft choice previous to anterior cruciate ligament reconstruction.
RESUMEN
Biodiversity crises have led scientists to develop strategies for achieving conservation goals. The underlying principle of these strategies lies in systematic conservation planning (SCP), in which there are at least 2 conflicting objectives, making it a good candidate for multi-objective optimization. Although SCP is typically applied at the species level (or hierarchically higher), it can be used at lower hierarchical levels, such as using alleles as basic units for analysis, for conservation genetics. Here, we propose a method of SCP using a multi-objective approach. We used non-dominated sorting genetic algorithm II in order to identify the smallest set of local populations of Dipteryx alata (baru) (a Brazilian Cerrado species) for conservation, representing the known genetic diversity and using allele frequency information associated with heterozygosity and Hardy-Weinberg equilibrium. We worked in 3 variations for the problem. First, we reproduced a previous experiment, but using a multi-objective approach. We found that the smallest set of populations needed to represent all alleles under study was 7, corroborating the results of the previous study, but with more distinct solutions. In the 2nd and 3rd variations, we performed simultaneous optimization of 4 and 5 objectives, respectively. We found similar but refined results for 7 populations, and a larger portfolio considering intra-specific diversity and persistence with populations ranging from 8-22. This is the first study to apply multi-objective algorithms to an SCP problem using alleles at the population level as basic units for analysis.
Asunto(s)
Algoritmos , Alelos , Conservación de los Recursos Naturales/estadística & datos numéricos , Dipteryx/genética , Variación Genética , Brasil , Conservación de los Recursos Naturales/métodos , Frecuencia de los Genes , Heterocigoto , Humanos , Repeticiones de MicrosatéliteRESUMEN
Apoptosis is a highly complex form of cell death that can be triggered by alterations in Ca(2+) homeostasis. Members of the Bcl-2 family may regulate apoptosis and modulate Ca(2+) distribution within intracellular compartments. Bax, a proapoptotic member of the family, is constitutively expressed and soluble in the cytosol and, under apoptotic induction, translocates to mitochondrial membranes. However, it is not clear if the intracellular Ca(2+) stores and selective Ca(2+) releases can modulate or control Bax translocation. The aim of this study was to investigate the relation of intracellular Ca(2+) stores with Bax translocation in rat cortical astrocytes. Results show that the classical apoptotic inducer, staurosporine, caused high elevations of cytosolic Ca(2+) that precede Bax translocation. On the other hand, agents that mobilize Ca(2+) from endoplasmic reticulum such as noradrenaline or thapsigargin, induced Bax translocation, while mitochondrial Ca(2+) release evoked by carbonyl cyanide-p-(trifluoromethoxyphenyl) hydrazone was not able to cause Bax punctation. In addition, microinjection of inositol 1,4,5- trisphosphate induced Bax translocation. Taken together, our results show that in Bax overexpressing cortical astrocytes, endoplasmic reticulum-Ca(2+) release may induce Bax transactivation and specifically control apoptosis.
Asunto(s)
Astrocitos/metabolismo , Calcio/metabolismo , Corteza Cerebral/metabolismo , Retículo Endoplásmico/metabolismo , Proteína X Asociada a bcl-2/metabolismo , Animales , Apoptosis , Células Cultivadas , Corteza Cerebral/citología , Citometría de Flujo , Microinyecciones , Transporte de Proteínas , RatasRESUMEN
AIM: To compare cone-beam computed tomography (CBCT) with periapical radiography for the identification of simulated endodontic complications. METHODOLOGY: Sixteen human teeth, in three mandibles, were submitted to the following simulated endodontic complications: G1) fractured endodontic file; G2) root perforation; G3) cast post with deviation; G4) external root resorption. Periapical radiographs were taken of each tooth at three different angles, and CBCT scan was taken. One calibrated examiner who was specialized in dental radiology interpreted the images. The results were analysed using the following scoring system: 0 - unidentified alteration; 1 - alteration identified with inaccurate diagnosis; and 2 - alteration identified with accurate diagnosis. Data were analysed using McNemar and Wilcoxon tests (alfa=0.05). RESULTS: In the overall assessment, CBCT was superior when compared with periapical radiographs (P<0.05). When individual results on each complication were evaluated, CBCT was superior only in the identification of external root resorption (100% Score 2) (P<0.05). CONCLUSION: Cone-beam computed tomography could be an alternative to periapical radiographs especially in the detection and assessment of external root resorption.
Asunto(s)
Cavidad Pulpar/diagnóstico por imagen , Cuerpos Extraños/diagnóstico por imagen , Enfermedades Periapicales/diagnóstico por imagen , Radiografía Dental/instrumentación , Tratamiento del Conducto Radicular/efectos adversos , Ápice del Diente/diagnóstico por imagen , Tomografía Computarizada de Haz Cónico , Instrumentos Dentales , Humanos , Mandíbula/diagnóstico por imagen , Enfermedades Periapicales/etiología , Técnica de Perno Muñón , Radiografía Dental/métodos , Tratamiento del Conducto Radicular/instrumentación , Resorción Radicular/diagnóstico por imagenRESUMEN
AIM: To establish the association between the obstruction site, whether it is unilateral or bilateral, age group, and sex. METHODS: A retrospective observational study of 1000 lacrimal ducts of 500 consecutive patients seen in the Emílio Amorim Radiological Clinic, who were suspected of having lacrimal duct obstructions, was performed. RESULTS: Of the studied patients, 121 were men and 379 were women. Their ages varied between 2 years and 93 years. 148 of the examinations were normal; in 298 the obstructions were unilateral and in 54 they were bilateral. The majority of the obstructions occurred at the valve of Krause. There was a significant difference in the correlation of the obstruction site with sex. The obstruction was total in 378 valves and partial in 28. Other findings included sinusitis, osteomas, bone fractures, fistulae, diverticulum, and lacrimal stones. CONCLUSION: Obstruction of the lacrimal ducts is normally total, unilateral, and sited at the valve of Krause. The obstruction of this valve predominantly affects women, whereas obstruction of the valve of Hasner mainly affects men. There was no significant difference in the distribution of obstructions by age group.
Asunto(s)
Aparato Lagrimal/diagnóstico por imagen , Obstrucción del Conducto Lagrimal/diagnóstico por imagen , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Técnicas de Diagnóstico Oftalmológico , Femenino , Humanos , Obstrucción del Conducto Lagrimal/terapia , Masculino , Persona de Mediana Edad , Radiografía , Estudios Retrospectivos , Distribución por SexoRESUMEN
In the present study, we evaluated proapoptotic protein Bax on mitochondria and Ca2+ homeostasis in primary cultured astrocytes. We found that recombinant Bax (rBax, 10 and 100 ng/ml) induces a loss in mitochondrial membrane potential (Delta Psi m). This effect might be related to the inhibition of respiratory rates and a partial release of cytochrome c, which may change mitochondrial morphology. The loss of Delta Psi m and a selective permeabilization of mitochondrial membranes contribute to the release of Ca2+ from the mitochondria. This was inhibited by cyclosporin A (5 microM) and Ruthenium Red (1 microg/ml), indicating the involvement of mitochondrial Ca2+ transport mechanisms. Bax-induced mitochondrial Ca2+ release evokes Ca2+ waves and wave propagation between cells. Our results show that Bax induces mitochondrial alteration that affects Ca2+ homeostasis and signaling. These changes show that Ca2+ signals might be correlated with the proapoptotic activities of Bax.
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Apoptosis/fisiología , Astrocitos/metabolismo , Señalización del Calcio/fisiología , Calcio/metabolismo , Líquido Intracelular/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Animales , Animales Recién Nacidos , Apoptosis/efectos de los fármacos , Astrocitos/efectos de los fármacos , Señalización del Calcio/efectos de los fármacos , Respiración de la Célula/fisiología , Células Cultivadas , Ciclosporina/farmacología , Citocromos c/metabolismo , Membranas Intracelulares/efectos de los fármacos , Membranas Intracelulares/metabolismo , Potenciales de la Membrana/efectos de los fármacos , Potenciales de la Membrana/fisiología , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Ratas , Rojo de Rutenio/farmacología , Proteína X Asociada a bcl-2RESUMEN
Intracellular calcium homeostasis is important for cell survival. However, increase in mitochondrial calcium (Ca2+m) induces opening of permeability transition pore (PTP), mitochondrial dysfunction and apoptosis. Since alterations of intracellular Ca2+ and reactive oxygen species (ROS) generation are involved in cell death, they might be involved in neurodegenerative processes such as Huntington's disease (HD). HD is characterized by the inhibition of complex II of respiratory chain and increase in ROS production. In this report, we studied the correlation between the inhibitor of the complex II, 3-nitropropionic acid (3NP), Ca2+ metabolism, apoptosis and behavioural alterations. We showed that 3NP (1 mm) is able to release Ca2+m, as neither Thapsigargin (TAP, 2 microm) nor free-calcium medium affected its effect. PTP inhibitors and antioxidants inhibited this process, suggesting an increase in ROS generation and PTP opening. In addition, 3NP (0.1 mm) also induces apoptotic cell death. Behavioural changes in animals treated with 3NP (20 mg/kg/day for 4 days) were also attenuated by pre- and co-treatment with vitamin E (VE, 20 mg/kg/day). Taken together, our results show that complex II inhibition could involve Ca2+m release, oxidative stress and cell death that may precede motor alterations in neurodegenerative processes such as HD.
Asunto(s)
Apoptosis , Astrocitos/metabolismo , Calcio/metabolismo , Mitocondrias/metabolismo , Enfermedades Neurodegenerativas/metabolismo , Estrés Oxidativo , Animales , Antioxidantes/farmacología , Apoptosis/efectos de los fármacos , Astrocitos/efectos de los fármacos , Astrocitos/patología , Conducta Animal/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Cruzamientos Genéticos , Modelos Animales de Enfermedad , Complejo II de Transporte de Electrones/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Colorantes Fluorescentes , Masculino , Ratones , Mitocondrias/efectos de los fármacos , Enfermedades Neurodegenerativas/inducido químicamente , Enfermedades Neurodegenerativas/patología , Nitrocompuestos , Estrés Oxidativo/efectos de los fármacos , Propionatos , Desacopladores/farmacología , Vitamina E/farmacologíaRESUMEN
Cellular Ca2+ signals are crucial in the control of most physiological processes, cell injury and programmed cell death through the regulation of a number of Ca2+-dependent enzymes such as phospholipases, proteases, and nucleases. Mitochondria along with the endoplasmic reticulum play pivotal roles in regulating intracellular Ca2+ content. Mitochondria are endowed with multiple Ca2+ transport mechanisms by which they take up and release Ca2+ across their inner membrane. During cellular Ca2+ overload, mitochondria take up cytosolic Ca2+, which in turn induces opening of permeability transition pores and disrupts the mitochondrial membrane potential (deltapsim). The collapse of deltapsim along with the release of cytochrome c from mitochondria is followed by the activation of caspases, nuclear fragmentation and cell death. Members of the Bcl-2 family are a group of proteins that play important roles in apoptosis regulation. Members of this family appear to differentially regulate intracellular Ca2+ level. Translocation of Bax, an apoptotic signaling protein, from the cytosol to the mitochondrial membrane is another step in this apoptosis signaling pathway.
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Apoptosis/fisiología , Señalización del Calcio/fisiología , Linfocinas/fisiología , Mitocondrias/fisiología , Proteínas Proto-Oncogénicas c-bcl-2/fisiología , Animales , Proteínas Proto-Oncogénicas/fisiología , Proteína X Asociada a bcl-2RESUMEN
Cellular Ca2+ signals are crucial in the control of most physiological processes, cell injury and programmed cell death through the regulation of a number of Ca2+-dependent enzymes such as phospholipases, proteases, and nucleases. Mitochondria along with the endoplasmic reticulum play pivotal roles in regulating intracellular Ca2+ content. Mitochondria are endowed with multiple Ca2+ transport mechanisms by which they take up and release Ca2+ across their inner membrane. During cellular Ca2+ overload, mitochondria take up cytosolic Ca2+, which in turn induces opening of permeability transition pores and disrupts the mitochondrial membrane potential (Dym). The collapse of Dym along with the release of cytochrome c from mitochondria is followed by the activation of caspases, nuclear fragmentation and cell death. Members of the Bcl-2 family are a group of proteins that play important roles in apoptosis regulation. Members of this family appear to differentially regulate intracellular Ca2+ level. Translocation of Bax, an apoptotic signaling protein, from the cytosol to the mitochondrial membrane is another step in this apoptosis signaling pathway