RESUMEN
BACKGROUND: Parents with learning disabilities report facing a widely held 'presumption of incompetence', placing them under pressure to prove their parenting competence. In collaboration with a learning disability theatre company, an inclusive research methodology explored experiences of parenting with learning disabilities, with a specific focus on the operation of stigma in parents' lives. METHOD: Interviews with 17 mothers and 5 fathers who self-identified as having learning disabilities were co-facilitated by learning-disabled co-researchers, and analysed using thematic analysis, with input from people with learning disabilities. RESULTS: Thematic analysis generated four key themes; (1) positions of powerlessness, (2) assumptions of incompetence, (3) challenging assumptions and proving competence and (4) claiming power. CONCLUSION: Parents reported experiencing stigma and disempowerment within their networks, yet continued to embrace their valued parental identity and drew strength from involvement with self-advocacy organisations. The research informed arts-based performance pieces and resources aimed at training professionals and raising public awareness.
Asunto(s)
Discapacidad Intelectual , Discapacidades para el Aprendizaje , Femenino , Humanos , Responsabilidad Parental , Padres , Estigma SocialRESUMEN
Although the role of Na(+) in several aspects of Ca(2+) regulation has already been shown, the exact mechanism of intracellular Ca(2+) concentration ([Ca(2+)](i)) increase resulting from an enhancement in the persistent, non-inactivating Na(+) current (I(Na,P)), a decisive factor in certain forms of epilepsy, has yet to be resolved. Persistent Na(+) current, evoked by veratridine, induced bursts of action potentials and sustained membrane depolarization with monophasic intracellular Na(+) concentration ([Na(+)](i)) and biphasic [Ca(2+)](i) increase in CA1 pyramidal cells in acute hippocampal slices. The Ca(2+) response was tetrodotoxin- and extracellular Ca(2+)-dependent and ionotropic glutamate receptor-independent. The first phase of [Ca(2+)](i) rise was the net result of Ca(2+) influx through voltage-gated Ca(2+) channels and mitochondrial Ca(2+) sequestration. The robust second phase in addition involved reverse operation of the Na(+)-Ca(2+) exchanger and mitochondrial Ca(2+) release. We excluded contribution of the endoplasmic reticulum. These results demonstrate a complex interaction between persistent, non-inactivating Na(+) current and [Ca(2+)](i) regulation in CA1 pyramidal cells. The described cellular mechanisms are most likely part of the pathomechanism of certain forms of epilepsy that are associated with I(Na,P). Describing the magnitude, temporal pattern and sources of Ca(2+) increase induced by I(Na,P) may provide novel targets for antiepileptic drug therapy.
Asunto(s)
Calcio/metabolismo , Hipocampo/efectos de los fármacos , Potenciales de la Membrana/efectos de los fármacos , Sodio/metabolismo , Veratridina/farmacología , Animales , Animales Recién Nacidos , Anticonvulsivantes/farmacología , Biofisica , Cloruro de Cadmio/farmacología , Carbonil Cianuro m-Clorofenil Hidrazona/farmacología , Clonazepam/análogos & derivados , Clonazepam/farmacología , Estimulación Eléctrica/métodos , Inhibidores Enzimáticos/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Hipocampo/citología , Técnicas In Vitro , Ionóforos/farmacología , Masculino , Potenciales de la Membrana/fisiología , Técnicas de Placa-Clamp , Células Piramidales/efectos de los fármacos , Células Piramidales/fisiología , Ratas , Ratas Wistar , Bloqueadores de los Canales de Sodio/farmacología , Tetrodotoxina/farmacología , Tapsigargina/farmacología , Tiazepinas/farmacologíaRESUMEN
STUDY DESIGN: A novel degenerative disc disease model and sustained delivery method for corticosteroid in male Sprague-Dawley albino rats. OBJECTIVES: To develop a model of degenerative disc disease and to determine the effect of continuous sustained release of corticosteroid on the process of degeneration within the traumatized disc. SUMMARY OF BACKGROUND DATA: The current modalities of treating symptomatic degenerative disc disease are either conservative or surgical. However, there is no cure for the degenerative process and prevention, therefore, is the ideal treatment. An understanding of the mechanisms involved in disc degeneration is crucial to develop new methods for prevention and treatment, including appropriate delivery systems and dosages of repair factors. METHODS: The L5-L6 intervertebral disc was pierced with a 23-gauge needle in 18 rats. The animals received either sham or corticosterone-charged tricalcium phosphate ceramic capsules. The rats were euthanized at 4 weeks. Chondrocytes in the transition zone areas were counted and compared statistically. RESULTS: The surgical technique induced degeneration of the nucleus without evidence of inflammation at adjacent levels when compared with nontraumatized controls. The number of chondrocytes per area was significantly less in the sham group than in the control group. Corticosteroid treatment showed chondrocyte numbers similar to control in 4 of 5 different views of the disc. The anterior region of the disc had 50% less chondrocytes per area than the control; however, the chondrocyte numbers were 50% greater than in the same site from discs of sham animals. CONCLUSIONS: The results show the development of a degenerative disc animal model that can be used to test the effects of growth enhancing factors in disc repair. Administration of continuous sustained release of corticosterone can slow the process of degeneration within the traumatized disc in the rat model.
Asunto(s)
Antiinflamatorios/farmacología , Corticosterona/farmacología , Degeneración del Disco Intervertebral/tratamiento farmacológico , Disco Intervertebral/efectos de los fármacos , Animales , Antiinflamatorios/uso terapéutico , Materiales Biocompatibles/farmacología , Materiales Biocompatibles/uso terapéutico , Fosfatos de Calcio/farmacología , Fosfatos de Calcio/uso terapéutico , Recuento de Células , Condrocitos/citología , Condrocitos/efectos de los fármacos , Condrocitos/fisiología , Corticosterona/uso terapéutico , Modelos Animales de Enfermedad , Esquema de Medicación , Fibrocartílago/citología , Fibrocartílago/efectos de los fármacos , Fibrocartílago/fisiología , Inflamación/tratamiento farmacológico , Inflamación/patología , Inflamación/fisiopatología , Disco Intervertebral/citología , Disco Intervertebral/fisiología , Degeneración del Disco Intervertebral/patología , Degeneración del Disco Intervertebral/fisiopatología , Masculino , Ratas , Ratas Sprague-Dawley , Regeneración/efectos de los fármacos , Regeneración/fisiología , Resultado del TratamientoRESUMEN
Management of bone infection and resulting bony defects is one of the major issues in Orthopaedic surgery. Systemic antibiotic therapy alone does not usually eradicate bacteria because of poor penetration into bone. Therefore, local application of aminoglycoside antibiotics at the site of infection can provide high drug concentrations to eradicate the bacteria. Aminoglycosides have been shown to be toxic to certain cells in the ears and in the kidneys. Approximately 5-10% of the people who are treated with aminoglycosides experience some side effect, affecting their hearing, sense of balance, or kidneys. Little information exists in the literature addressing the effects of the aminoglycoside, Tobramycin, on osteoblast cells. MG63 osteoblast-like cell line, were treated with varying concentrations of Tobramycin (0, 10, 50, 100microM) over a period of 24, 48 and 72 hours, harvesting them after each time period and performing assays to test their metabolic function (Glutathione assay) and cell membrane viability (MDA). The results show that Tobramycin at concentrations greater than the minimum inhibitory concentration (MIC) caused marked reductions in cell number with increased membrane damage as early as 48 hours. Glutathione levels within the cells were increased in the 50uM and 100uM treatments as early as 24 hours indicating impaired metabolic function. These results may have implications for using Tobramycin as antibacterial prophylaxis in Orthopaedic surgery, as its toxic effects may interfere with the osteoblasts ability to form bone, and delay healing.
Asunto(s)
Membrana Celular/metabolismo , Supervivencia Celular/efectos de los fármacos , Glutatión/metabolismo , Osteoblastos/efectos de los fármacos , Osteoblastos/fisiología , Fosfolípidos/metabolismo , Tobramicina/administración & dosificación , Antibacterianos/administración & dosificación , Línea Celular , Membrana Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Osteoblastos/citologíaRESUMEN
Demineralized bone matrix (DBM) has been shown to possess osteoinductive capability and one of the specific bone morphogenetic proteins (BMPs) found within DBM that has been attributed with this osteoinductive ability is BMP-7, also known as osteogenic protein-1 (OP-1). The specific aims of this study were (1) to compare the treatment of segmental bone defects with OP-l and DBM in a rat femur model and (2) to determine the effects of the two treatments given at high and low doses via sustained release drug delivery. Animals in Group 1 acted as the control and Group 2 had a created segmental defect with plating and placement of a calcined tricalcium phosphate lysine (TCPL) capsule containing antibiotic (sham). Group 3 and 4 animals had a created segmental defect and received a TCPL carrier containing antibiotic along with DBM or OP-1, respectively. After 4 weeks post-implantation, animals were sacrificed before the retrieval of the bone. The femora were analyzed radiographically and histologically for bone growth. Analysis of the gross specimens showed considerable bone regeneration at low and high doses for both DBM and OP-1 when compared to the shams. At low levels bone regeneration between DBM and OP-1 was very similar. However, at high doses, OP-1 was shown to cause bone overgrowth with a greater curvature and an increased thickness of the distal and proximal ends of the femur. The stained slides showed the defects treated with DBM and OP-1 to be bridged with lamellar and woven bone that was continuous with the original bone. Histologically, the experimental femora demonstrated natural remodeling processes with new osteons and angiogenesis.
Asunto(s)
Proteínas Morfogenéticas Óseas/administración & dosificación , Preparaciones de Acción Retardada/administración & dosificación , Fracturas del Fémur/tratamiento farmacológico , Fémur/efectos de los fármacos , Curación de Fractura/efectos de los fármacos , Tobramicina/administración & dosificación , Factor de Crecimiento Transformador beta/administración & dosificación , Animales , Antibacterianos/administración & dosificación , Proteína Morfogenética Ósea 7 , Sustitutos de Huesos/uso terapéutico , Modelos Animales de Enfermedad , Combinación de Medicamentos , Fracturas del Fémur/diagnóstico por imagen , Fracturas del Fémur/patología , Fémur/diagnóstico por imagen , Fémur/patología , Radiografía , Ratas , Ratas Sprague-Dawley , Trasplante Homólogo/métodos , Resultado del TratamientoRESUMEN
Bone grafts are used to treat various disorders, including delayed union and nonunion of fractures, congenital pseudoarthrosis, and osseous defects from trauma, infection, and tumors. Bone graft substitutes provide surgeons a wide range of materials, structures, and potential delivery systems to use in bone grafting procedures. In addition, the materials may be used as scaffolds to deliver patient derived bone cells. The goal of this study was to seed MG63 osteoblast cells onto three different material constructs--TCP, ZnCaP and ProOsteon--and to compare the growth characteristics of the cells in reaction to the materials. Cellular response to the material was evident as early as 24 hours following the addition of cells onto the constructs. Cells were found adjacent to and along the TCP and ZnCaP carrier, while in the ProOsteon group, the cells appeared non-adhered and more round than spindle shaped. Type I collagen synthesis was highly evident in the TCP and ZnCaP groups at the end of 16 days, whereas little cellular activity was noted around the ProOsteon construct. The overall results suggest a favorable environment for bone cell growth on TCP and ZnCaP materials. The materials may serve as delivery systems for cells in tissue engineering fields in the future.
Asunto(s)
Materiales Biocompatibles/administración & dosificación , Fosfatos de Calcio/administración & dosificación , Durapatita/administración & dosificación , Osteoblastos/citología , Osteoblastos/fisiología , Osteogénesis/fisiología , Sulfato de Zinc/administración & dosificación , Sustitutos de Huesos/administración & dosificación , Línea Celular , Proliferación Celular/efectos de los fármacos , Tamaño de la Célula/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Humanos , Ensayo de Materiales , Osteoblastos/efectos de los fármacos , Osteogénesis/efectos de los fármacosRESUMEN
Bone morphogenetic proteins (BMPs) are a group of structurally related proteins in the transforming growth factor-beta (TGF-beta) family which have been shown to stimulate bone formation in vivo. Since these proteins are concentrated in the organic matrix of bone and would be released after a fracture or during bone resorption, they are likely to have a profound effect on bone remodeling and may provide a link between bone resorption and bone formation. The hypothesis of this study was that osteoblast-like cells (OBs) treated with demineralized bone matrix (DBM) would have similar levels of secretion of osteopontin (OPN) and osteocalcin (OCN) to that of OBs treated with insulin-like growth factor-1 (IGF-1), while OBs treated with bone morphogenetic protein-7, also called osteogenic protein-1 (OP-1), would secrete levels of OPN and OCN less than the DBM group. Specifically, the aims of this study were to evaluate osteoblast-like cells (MG-63 cell line) for secretion of both OPN and OCN after treatment with DBM, OP-1, or IGF-1 compared to control, at 24, 48, and 72 hours. After each incubation period, ELISA kits were used to determine the levels of osteopontin and osteocalcin production. The results clearly demonstrated a rise of OCN at 48 hours and a fall at 72 hours for all samples, including control groups. However, there was no significant difference between groups (p > 0.05). With the OPN assay, results showed no significant difference between groups until 72 hours (p = 0.022), where the IGF-1 group was significantly higher than the Control and DBM groups (p = 0.003 and p = 0.021, respectively). This information is important for understanding the signaling pathways that may be initiated in the osteoblast following stimulation with growth factors.
Asunto(s)
Matriz Ósea/metabolismo , Proteínas Morfogenéticas Óseas/administración & dosificación , Factor I del Crecimiento Similar a la Insulina/administración & dosificación , Osteoblastos/metabolismo , Osteocalcina/biosíntesis , Proteínas/administración & dosificación , Sialoglicoproteínas/biosíntesis , Matriz Ósea/efectos de los fármacos , Proteína Morfogenética Ósea 7 , Calcificación Fisiológica/efectos de los fármacos , Calcificación Fisiológica/fisiología , Línea Celular , Relación Dosis-Respuesta a Droga , Humanos , Factor II del Crecimiento Similar a la Insulina , Osteoblastos/efectos de los fármacos , Osteopontina , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiologíaRESUMEN
Signals are transduced across the cell membrane through a series of events that are triggered by the activation of receptors or opening of ion channels. It is evident that the stimulation of cells can elicit a series of catabolic cascades, which cause degradation of several membrane phospholipids. Several breakdown products participate directly in the intracellular signaling cascade. The objective of this study was to establish the changes in phospholipid pools of MG-63 cells in 15 and 30 minutes after stimulation with IGF-1, which is a known growth factor. After collection of the cells, methods were performed to prepare the samples for thin-layer chromatography. Silica gel plates were analyzed for each experiment for quantitative and qualitative data. The cells were also tested for alkaline phosphatase activity. The highest percent of radioactivity was within the phosphatidylcholine fraction of control cells at 15 minutes and phosphatidylserine at 30 minutes. The highest percent of radioactivity was in the phosphatidylserine fraction at 15 minutes and increased after 30 minutes in IGF-1 treated cells.
Asunto(s)
Factor I del Crecimiento Similar a la Insulina/administración & dosificación , Osteoblastos/metabolismo , Fosfolípidos/metabolismo , Línea Celular , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Osteoblastos/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiologíaRESUMEN
Glycolysis is a very important process which contains very intricate steps that play a role in cellular performance and viability. Fructose 1,6-bisphosphate (FBP) is a glycolytic intermediate that has proven to improve cellular conditions under hypoxic and ischemic conditions. Osteoblasts are key regulators of skeletal matrix synthesis and degradation. Thus, considering FBP's positive effects on ameliorating hypoxia-induced injuries, the objective of this study was to determine its effects and comparative effects on osteoblast cells under normoxic and hypoxic states. MG63 osteoblast-like cells were cultured in 24-well culture plates and treated with high, medium and low dosages of FBP at 24, 48, and 72 hours. At the end of each time period, cellular number, damage by a malondialdehyde assay (MDA), and glutathione levels were evaluated. There was a significant increase in cell number for the low level of FBP in normoxia at 48 hours (p < 0.05). For the cells in hypoxia, there was a significant decrease in cell number for the medium level at 48 hours (p < 0.05). At 48 hours there was a significant decrease in cell damage through MDA measurement for the cells in normoxia and hypoxia when compared to the control. Cellular damage was not evident in the supernatant in either oxygen condition for the duration of the study. A significant decrease in glutathione levels was also noted for the cells in hypoxia. Cellular morphology included multiple nucleoli, vacuolated cytoplasm, abnormal cells, and web-like cytoplasm. The results indicate that FBP does protect bone cells exposed to hypoxic injuries, and while doing so, ameliorating the states of the cells in shock.
Asunto(s)
Hipoxia de la Célula/fisiología , Fructosadifosfatos/administración & dosificación , Osteoblastos/citología , Osteoblastos/fisiología , Oxígeno/metabolismo , Apoptosis/efectos de los fármacos , Hipoxia de la Célula/efectos de los fármacos , Línea Celular , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Glucólisis/efectos de los fármacos , Humanos , Osteoblastos/efectos de los fármacosRESUMEN
Increasing osteoblast activity in an anabolic fashion may offer an ideal therapeutic treatment for various orthopedic complications including osteoporosis. The purpose of this study was to evaluate the effect of mevinolin, a clinical statin drug, on osteoblast function (MG 63 Cell Line) and compare its mode of action with the conventionally utilized parathyroid hormone (PTH). MG63 cells were treated with different concentrations (control, low (100 nM), medium (1 uM), and high (10 uM)) of mevinolin or Parathyroid hormone. The cells were incubated for 24, 48, and 72 hours at 37 degrees C in a 95% air and 5% CO2 environmental chamber. Data obtained in this study revealed that: (I) there were significant decreases in cell number after 24 hours upon the exposure of medium and high doses of mevinolin, (II) cell numbers rebounded back toward control after 48 hours and were similar in number at 72 hours, and (III) there were no significant changes in calcium or alkaline phosphatase activity were observed throughout the study. Morphologically, the cells treated with various doses of Mevinolin expressed similar structural changes to those observed using PTH. These changes included pleomorphic characteristics and an occasional hyperchromatic pattern during the entire duration of the study (72 Hours). Other structural features observed were spindle shapes, cluster arrangements and multinucleation. The majority of cells had multiple nucleoli in all treated groups compared to controls. The overall conclusion of this investigation demonstrated that the concentrations used (100 nM and 10 microM) did not appear to affect the mitotic activities of immature phenotypic MG-63 cells. In addition, the concentrations of mevinolin used did not trigger the differentiation process of the cells throughout the experimental phases. This observation led us to suggest that the reason for such an outcome could be attributed to the lack of a response in calcium production or alkaline phosphatase activity (stimulator to differentiation and mineralization process).
Asunto(s)
Lovastatina/administración & dosificación , Osteoblastos/citología , Osteoblastos/fisiología , Hormona Paratiroidea/administración & dosificación , Diferenciación Celular/efectos de los fármacos , Línea Celular , Proliferación Celular/efectos de los fármacos , Tamaño de la Célula/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/administración & dosificación , Osteoblastos/efectos de los fármacosRESUMEN
Insulin-like Growth Factor-1 (IGF-1) and Parathyroid hormones (PTH) are major endocrine secretions that contribute to bone formation. The purpose of this experiment was to examine MG-63 bone like cells after treatment with PTH and IGF-1 in low (1 ug), medium (5 ug), and high (50 ug) dosage levels. MG-63 cells were plated onto a 24 well tissue culture plate at a density of 1 x 1--5 cells per well. The experiment was designed to evaluate cell counts, cell damage (MDA), protein levels, calcium levels, alkaline phosphatase levels, and cellular morphology after 24, 48, and 72 hours post incubation with IGF-1 and PTH. Both hormones stimulated cellular mitotic division as evidenced by morphology and cell numbers. There was an inverse relationship between dose and cell number with the lower dose of IGF-1 and PTH causing the most increase. In both hormones, the exposure to the highest dose induced the largest MDA level increase. However, in the protein levels, few changes in protein levels were found with IGF-1, but PTH showed an increase of protein levels over the time periods. Morphological evaluation showed prominent nucleoli and cellular division throughout both treatments, however the cells with IGF-1 became extremely elongated and the cells with PTH became rather plump. The information gathered suggests that IGF-1 and PTH have an anabolic effect on MG-63 and the effect is dose dependent with both treatments with the lower dose being more effective.