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1.
Bone ; 49(5): 955-64, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21810491

RESUMO

This review reports on proceedings of a bone histomorphometry session conducted at the Fortieth International IBMS Sun Valley Skeletal Tissue Biology Workshop held on August 1, 2010. The session was prompted by recent technical problems encountered in conducting histomorphometry on bone biopsies from humans and animals treated with anti-remodeling agents such as bisphosphonates and RANKL antibodies. These agents reduce remodeling substantially, and thus cause problems in calculating bone remodeling dynamics using in vivo fluorochrome labeling. The tissue specimens often contain few or no fluorochrome labels, and thus create statistical and other problems in analyzing variables such as mineral apposition rates, mineralizing surface and bone formation rates. The conference attendees discussed these problems and their resolutions, and the proceedings reported here summarize their discussions and recommendations.


Assuntos
Osso e Ossos/anatomia & histologia , Animais , Conservadores da Densidade Óssea/administração & dosagem , Difosfonatos/administração & dosagem , Humanos , Ligante RANK/imunologia
2.
Osteoporos Int ; 20(5): 793-800, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-18769963

RESUMO

UNLABELLED: Comparison of infrared spectroscopic images of sections from biopsies of placebo-treated post-menopausal women and women treated for 3 years with 10 mg/day alendronate demonstrated significant increases in cortical bone mineral content, no alterations in other spectroscopic markers of "bone quality," but a decrease in tissue heterogeneity. METHODS: The material properties of thick sections from iliac crest biopsies of seven alendronate-treated women were compared to those from ten comparably aged post-menopausal women without bone disease, using infrared spectroscopic imaging at approximately 7 microm spatial resolution. Parameters evaluated were mineral/matrix ratio, crystallinity, carbonate/amide I ratio, and collagen maturity. The line widths at half maximum of the pixel histograms for each parameter were used as measures of heterogeneity. RESULTS: The mineral content (mineral/matrix ratio) in the cortical bone of the treated women's biopsies was higher than that in the untreated control women. Crystallinity, carbonate/protein, and collagen maturity indices were not significantly altered; however, the pixel distribution was significantly narrowed for all cortical and trabecular parameters with the exception of collagen maturity in the alendronate treatment group. CONCLUSIONS: The increases in mineral density and decreased fracture risk associated with bisphosphonate treatment may be counterbalanced by a decrease in tissue heterogeneity, which could impair tissue mechanical properties. These consistent data suggest that alendronate treatment, while increasing the bone mass, decreases the tissue heterogeneity.


Assuntos
Alendronato/farmacologia , Conservadores da Densidade Óssea/farmacologia , Densidade Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Adulto , Osso e Ossos/anatomia & histologia , Osso e Ossos/fisiologia , Estudos de Casos e Controles , Método Duplo-Cego , Feminino , Humanos , Pessoa de Meia-Idade , Pós-Menopausa/fisiologia , Espectroscopia de Infravermelho com Transformada de Fourier
3.
Scand J Surg ; 96(4): 281-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18265854

RESUMO

The use of telemedicine is long-standing, but only in recent years has it been applied to the specialities of trauma, emergency care, and surgery. Despite being relatively new, the concept of teletrauma, telepresence, and telesurgery is evolving and is being integrated into modern care of trauma and surgical patients. This paper will address the current applications of telemedicine and telepresence to trauma and emergency care as the new frontiers of telemedicine application. The University Medical Center and the Arizona Telemedicine Program (ATP) in Tucson, Arizona have two functional teletrauma and emergency telemedicine programs and one ad-hoc program, the mobile telemedicine program. The Southern Arizona Telemedicine and Telepresence (SATT) program is an inter-hospital telemedicine program, while the Tucson ER-link is a link between prehospital and emergency room system, and both are built upon a successful existing award winning ATP and the technical infrastructure of the city of Tucson. These two programs represent examples of integrated and collaborative community approaches to solving the lack of trauma and emergency care issue in the region. These networks will not only be used by trauma, but also by all other medical disciplines, and as such have become an example of innovation and dedication to trauma care. The first case of trauma managed over the telemedicine trauma program or "teletrauma" was that of an 18-month-old girl who was the only survival of a car crash with three fatalities. The success of this case and the pilot project of SATT that ensued led to the development of a regional teletrauma program serving close to 1.5 million people. The telepresence of the trauma surgeon, through teletrauma, has infused confidence among local doctors and communities and is being used to identify knowledge gaps of rural health care providers and the needs for instituting new outreach educational programs.


Assuntos
Serviços Médicos de Emergência/métodos , Telemedicina/organização & administração , Telemetria/métodos , Ferimentos e Lesões/terapia , Humanos , Avaliação de Programas e Projetos de Saúde/métodos , Centros de Traumatologia
4.
Endocrinology ; 147(12): 5592-9, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16935844

RESUMO

Glucocorticoid administration to mice results in a rapid loss of bone mineral density due to an imbalance in osteoblast and osteoclast numbers. Whereas excess glucocorticoids reduce both osteoblast and osteoclast precursors, cancellous osteoclast number surprisingly does not decrease as does osteoblast number, presumably due to the ability of glucocorticoids to promote osteoclast life span. Whether glucocorticoids act directly on osteoclasts in vivo to promote their life span and whether this contributes to the rapid loss of bone with glucocorticoid excess remains unknown. To determine the direct effects of glucocorticoids on osteoclasts in vivo, we expressed 11beta-hydroxysteroid dehydrogenase type 2, an enzyme that inactivates glucocorticoids, specifically in the osteoclasts of transgenic mice using the tartrate-resistant acid phosphatase promoter. Bone mass, geometry, and histomorphometry were similar in untreated wild-type and transgenic animals. Glucocorticoid administration for 7 d caused equivalent increases in cancellous osteoblast apoptosis, and equivalent decreases in osteoblasts, osteoid, and bone formation, in wild-type and transgenic mice. In contrast, glucocorticoids stimulated expression of the mRNA for calcitonin receptor, an osteoclast product, in wild-type but not transgenic mice. Consistent with the previous finding that glucocorticoids decrease osteoclast precursors and prolong osteoclast life span, glucocorticoids decreased cancellous osteoclast number in the transgenic mice but not wild-type mice. In accord with this decrease in osteoclast number, the loss of bone density observed in wild-type mice was strikingly prevented in transgenic mice. These results demonstrate for the first time that the early, rapid loss of bone caused by glucocorticoid excess results from direct actions on osteoclasts.


Assuntos
Densidade Óssea/efeitos dos fármacos , Glucocorticoides/farmacologia , Osteoclastos/efeitos dos fármacos , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/genética , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/metabolismo , Animais , Desenvolvimento Ósseo/genética , Osso e Ossos/metabolismo , Dexametasona/efeitos adversos , Dexametasona/farmacologia , Feminino , Glucocorticoides/efeitos adversos , Masculino , Camundongos , Camundongos Transgênicos , Especificidade de Órgãos , Osteoclastos/metabolismo , Prednisolona/farmacologia , Coluna Vertebral/citologia , Coluna Vertebral/efeitos dos fármacos , Coluna Vertebral/crescimento & desenvolvimento , Transgenes
5.
Osteoporos Int ; 15(3): 231-7, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14727011

RESUMO

The bisphosphonate ibandronate, administered either daily or intermittently with an extended between-dose interval of >2 months, has been shown to reduce significantly the incidence of vertebral fractures, to increase bone mineral density and to reduce levels of biochemical markers of bone turnover in a phase III randomized study in women with postmenopausal osteoporosis (PMO). Bone histomorphometry was performed on a subgroup of women participating in this study in order to assess bone quality and architecture. The patients were randomized to receive one of the following: placebo, continuous oral daily ibandronate (2.5 mg/day) or intermittent oral ibandronate (20 mg every other day for 12 doses every 3 months). Out of the overall study population of 2,946 patients, 110 were randomly assigned to undergo transiliac bone biopsy at either month 22 or month 34 of treatment. The primary safety endpoint was osteoid thickness in trabecular bone, which was measured to exclude treatment-induced bone mineralization defects. Secondary safety endpoints assessed bone volume, bone turnover and micro-architecture. The primary efficacy endpoint was bone mineralizing surface. In all bone biopsy cores, newly formed trabecular bone retained its structure without any signs of woven bone. Marrow fibrosis and signs of cellular toxicity were not observed. Quantitative assessment demonstrated no impairment in mineralization of bone matrix: osteoid thickness tended to be similar or slightly lower in the ibandronate groups versus the placebo group. All secondary safety variables and the bone efficacy parameter were consistent with the production of normal-quality, newly formed bone and a modest reduction in bone turnover with both ibandronate regimens relative to placebo. Long-term treatment with oral ibandronate, even when administered with an extended between-dose interval of >2 months, produces normal-quality, newly formed bone in women with PMO.


Assuntos
Difosfonatos/administração & dosagem , Ílio/patologia , Osteoporose Pós-Menopausa/tratamento farmacológico , Osteoporose Pós-Menopausa/patologia , Idoso , Biópsia , Remodelação Óssea , Esquema de Medicação , Feminino , Seguimentos , Humanos , Ácido Ibandrônico , Ílio/fisiopatologia , Osteoporose Pós-Menopausa/fisiopatologia , Ensaios Clínicos Controlados Aleatórios como Assunto
6.
Science ; 298(5594): 843-6, 2002 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-12399595

RESUMO

We show that sex steroids protect the adult murine skeleton through a mechanism that is distinct from that used to preserve the mass and function of reproductive organs. The classical genotropic actions of sex steroid receptors are dispensable for their bone protective effects, but essential for their effects on reproductive tissues. A synthetic ligand (4-estren-3alpha,17beta-diol) that reproduces the nongenotropic effects of sex steroids, without affecting classical transcription, increases bone mass and strength in ovariectomized females above the level of the estrogen-replete state and is at least as effective as dihydrotestosterone in orchidectomized males, without affecting reproductive organs. Such ligands merit investigation as potential therapeutic alternatives to hormone replacement for osteoporosis in both women and men [corrected].


Assuntos
Densidade Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Estrenos/farmacologia , Osteoblastos/efeitos dos fármacos , Osteoclastos/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Osso e Ossos/fisiologia , Neoplasias da Mama/patologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Força Compressiva/efeitos dos fármacos , Di-Hidrotestosterona/farmacologia , Estradiol/farmacologia , Estrenos/metabolismo , Feminino , Humanos , Masculino , Camundongos , Orquiectomia , Tamanho do Órgão/efeitos dos fármacos , Osteoblastos/fisiologia , Osteocalcina/sangue , Osteoclastos/fisiologia , Osteogênese/efeitos dos fármacos , Osteoporose/tratamento farmacológico , Ovariectomia , Pirazóis/farmacologia , Receptores de Estrogênio/metabolismo , Glândulas Seminais/efeitos dos fármacos , Transcrição Genética/efeitos dos fármacos , Células Tumorais Cultivadas , Útero/efeitos dos fármacos , Útero/metabolismo
7.
Child Dev ; 72(5): 1554-78, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11699687

RESUMO

A path model of teacher expectancy effects was evaluated in a sample of 376 first- through fifth-grade urban elementary school children. The roles of two moderators (classroom perceived differential treatment environment and developmental differences) and one mediator (children's self-expectations) of teacher expectancy effects on children's year-end achievement were examined. Significant differences in effects and effect sizes are presented. Both classroom environment (high versus low in differential treatment, as seen through children's eyes) and developmental differences moderated the strength of teacher expectancy effects. Generally, stronger effects were found in classrooms in which expectancy-related cues were more salient to children, but developmental differences moderated which effect was most pronounced. A significant age-related decline in direct effects on ending achievement was interpreted as evidence that teacher expectations may tend to magnify achievement differences in the early grades, but serve to sustain them in later grades. Support for indirect effects (teacher expectations --> children's self-expectations --> ending achievement) was limited to upper elementary grade classrooms perceived as high in differential treatment. In contrast to prior research that emphasized small effect sizes, the present analyses document several instances of moderate effects, primarily in classrooms in which expectancy-related messages were most salient to children. These results underscore the importance of explicit attention to the inclusion of moderators, mediators, and multiple outcomes in efforts to understand teacher expectancy effects.


Assuntos
Atitude , Escolaridade , Docentes , Individualidade , Autoimagem , Fatores Etários , Criança , Feminino , Seguimentos , Humanos , Masculino , Modelos Educacionais , Estudos Prospectivos , Ensino
8.
Rev Endocr Metab Disord ; 2(1): 65-73, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11708295

RESUMO

During normal bone remodeling, the supply of new osteoblasts and osteoclasts and the timing of the death of osteoclasts, osteoblasts and osteocytes by apoptosis are critical determinants of the initiation of new BMUs and the extension or reduction of the lifetime of existing ones. Many of the effects of chronic glucocorticoid administration on bone can be explained by decreased birth of osteoblast and osteoclast precursors and increased apoptosis of mature osteoblasts and osteocytes, disrupting the fine balance among these processes. Therapeutic agents that alter the prevalence of apoptosis of osteoblasts and osteoclasts can correct the imbalance in cell numbers that is the basis of the diminished bone mass and increased risk of fractures, found in glucocorticoid-induced osteoporosis.


Assuntos
Glucocorticoides/efeitos adversos , Osteoporose/induzido quimicamente , Osso e Ossos/patologia , Humanos , Osteoporose/patologia , Osteoporose/terapia
9.
J Bone Miner Res ; 16(10): 1754-64, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11585338

RESUMO

Smad3 is a well-characterized intracellular effector of the transforming growth factor beta (TGF-beta) signaling pathway and was implicated recently in the potentiation of vitamin D receptor (VDR)-mediated signaling. Given that both TGF-beta and vitamin D are important regulators of bone remodeling, it is expected that Smad3 plays an integral role in normal maintenance of bone. However, the exact mechanisms by which Smad3 functions in bone remodeling are unknown. Here, we show that mice with targeted deletion of Smad3 are osteopenic with less cortical and cancellous bone compared with wild-type littermates. Decreases in bone mineral density (BMD) in Smad3 null mice reflect the inability of osteoblasts to balance osteoclast activity, although osteoclast numbers are normal and vitamin D mediated serum calcium homeostasis is maintained. The osteopenia of Smad3 null mice is attributed to a decreased rate of bone formation associated with increased osteocyte number and apoptosis. These findings are supported by studies with isolated primary osteoblasts that show TGF-beta can no longer inhibit the differentiation of osteoblasts in the absence of Smad3; yet, TGF-beta-stimulated proliferation remains intact. Together these data support a model that a loss of Smad3 increases the osteocyte fate of the osteoblast and decreases the duration of osteoblast function by shortening lifespan, ultimately resulting in osteopenia.


Assuntos
Apoptose , Doenças Ósseas Metabólicas/metabolismo , Proteínas de Ligação a DNA/fisiologia , Osteoblastos/citologia , Osteogênese/fisiologia , Transativadores/fisiologia , Animais , Osso e Ossos/patologia , Cálcio/sangue , Contagem de Células , Diferenciação Celular , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Homeostase , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteoblastos/metabolismo , Osteoclastos/citologia , Osteócitos/citologia , Proteína Smad3 , Transativadores/genética , Transativadores/metabolismo , Fator de Crescimento Transformador beta/metabolismo
10.
J Bone Miner Res ; 16(10): 1879-85, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11585353

RESUMO

Endogenous Cushing's syndrome (CS) in children causes growth retardation, decreased bone mass, and increased total body fat. No prospective controlled studies have been performed in children to determine the long-term sequelae of CS on peak bone mass and body composition. A 15-year-old girl with Cushing disease (CD), and her healthy identical co-twin, were followed for 6 years after the CD was cured. At the 6-year follow-up both twins had areal bone mineral density (BMD) and body composition determined by dual-energy X-ray absorptiometry (DXA) and three-dimensional quantitative computed tomography (3DQCT). Z scores for height, weight, and body mass index (BMI) were -2.3, -0.8 and 0.2, and 1.2, 0.2, and -0.6, in the twin with CD and her co-twin, respectively. In the twin with CD, areal BMD and bone mineral apparent density (BMAD) at different sites varied from 0.7 to 3 SD below her co-twin. Volumetric lumbar spine bone density Z score was -0.75 and 1.0, and total body, abdominal visceral, and subcutaneous fat (%) was 42, 10, and 41 versus 26, 4, and 17 in the twin with CD and her co-twin, respectively. The relationship between total body fat and L2-L4 BMAD was inverse in the twin with CD (p < 0.05), which by contrast in her co-twin was opposite and direct (p < 0.001). In the twin with CD, despite cure, there was a persistent deficit in bone mass and increase in total and visceral body fat. These observations suggest that hypercortisolism (exogenous or endogenous) during adolescence may have persistent adverse effects on bone and fat mass.


Assuntos
Osso e Ossos/fisiopatologia , Síndrome de Cushing/metabolismo , Gorduras/metabolismo , Glucocorticoides/metabolismo , Adolescente , Composição Corporal , Líquidos Corporais , Densidade Óssea , Osso e Ossos/metabolismo , Síndrome de Cushing/diagnóstico por imagem , Síndrome de Cushing/fisiopatologia , Sistema Endócrino , Feminino , Seguimentos , Humanos , Radiografia , Gêmeos Monozigóticos
13.
Telemed J E Health ; 7(1): 27-31, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11321706

RESUMO

The goal of this investigation was to determine if there were identifiable patterns in the volume and types of teleconsults provided by an established telemedicine program over an extended period of time. Data from over 3 years of providing telemedicine consults within a university-based telemedicine programs were analyzed to identify trends and points of significant change in service provision. Teleconsult volume over a 40-month period was best fit by a logarithmic transformation of the regression curve that is characteristic of slow but steady growth. Consults have been provided in 53 subspecialties, with an average of 12 different subspecialties each month. Number of subspecialties per month was best fit by a sixth-order polynomial. Teleconsult volume has varied on a monthly basis, but overall volume has increased over time. This program has maintained its initial goal of being a multispecialty provider. Analyzing telemedicine consult data over extended periods of time is especially useful for long-term program evaluation and development of a successful business plan.


Assuntos
Encaminhamento e Consulta/estatística & dados numéricos , Consulta Remota/estatística & dados numéricos , Arizona , Humanos , Medicina/estatística & dados numéricos , Consulta Remota/organização & administração , Especialização , Revisão da Utilização de Recursos de Saúde
14.
Cell ; 104(5): 719-30, 2001 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-11257226

RESUMO

The relationship of the classical receptors and their transcriptional activity to nongenotropic effects of steroid hormones is unknown. We demonstrate herein a novel paradigm of sex steroid action on osteoblasts, osteocytes, embryonic fibroblasts, and HeLa cells involving activation of a Src/Shc/ERK signaling pathway and attenuating apoptosis. This action is mediated by the ligand binding domain and eliminated by nuclear targeting of the receptor protein; ERalpha, ERbeta, or AR can transmit it with similar efficiency irrespective of whether the ligand is an estrogen or an androgen. This antiapoptotic action can be dissociated from the transcriptional activity of the receptor with synthetic ligands, providing proof of principle for the development of function-specific-as opposed to tissue-selective-and gender-neutral pharmacotherapeutics.


Assuntos
Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Transdução de Sinais/fisiologia , Androgênios/farmacologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Sítios de Ligação/fisiologia , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Receptor alfa de Estrogênio , Receptor beta de Estrogênio , Estrogênios/farmacologia , Feminino , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/fisiologia , Células HeLa , Humanos , Técnicas In Vitro , Masculino , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/fisiologia , Osteoclastos/citologia , Osteoclastos/efeitos dos fármacos , Osteoclastos/fisiologia , Fragmentos de Peptídeos/farmacologia , Receptores Androgênicos/química , Receptores de Estrogênio/química , Fatores Sexuais , Transdução de Sinais/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/fisiologia , Domínios de Homologia de src/fisiologia , Quinases da Família src/metabolismo
16.
Hum Pathol ; 32(12): 1283-99, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11774159

RESUMO

Telepathology is the practice of pathology at a distance by using video imaging and telecommunications. Significant progress has been made in telepathology. To date, 12 classes of telepathology systems have been engineered. Rapid and ultrarapid virtual slide processors may further expand the range of telepathology applications. Next-generation digital imaging light microscopes, such as miniaturized microscope arrays (MMA), may make virtual slide processing a routine laboratory tool. Diagnostic accuracy of telepathology is comparable with that of conventional light microscopy for most diagnoses. Current telepathology applications include intraoperative frozen sections services, routine surgical pathology services, second opinions, and subspecialty consultations. Three telepathology practice models are discussed: the subspecialty practice (SSP) model; the case triage practice (CTP) model; and the virtual group practice (VGP) model. Human factors influence performance with telepathology. Experience with 500 telepathology cases from multiple organs significantly reduces the video viewing time per case (P < .01). Many technology innovations can be represented as S-curves. After long incubation periods, technology use and/or efficiency may accelerate. Telepathology appears to be following an S-curve for a technical innovation.


Assuntos
Consulta Remota/organização & administração , Telepatologia/organização & administração , Difusão de Inovações , Humanos , Modelos Teóricos , Consulta Remota/métodos , Telepatologia/métodos
17.
Hum Pathol ; 32(12): 1304-8, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11774161

RESUMO

This feasibility study examined the diagnostic accuracy of Internet-based dynamic-robotic telepathology using neuropathology cases. Randomly, 83 cases were selected from the routine diagnostic workload of the Neurosurgical Pathology Laboratory in Poznan, Poland. Telepathology diagnoses were compared with conventional paraffin section diagnosis. The neuropathologists, operating a robotically controlled motorized microscope over the Internet from 3 different Polish cities, individually reviewed the cases using computer workstations. Viewing times ranged from 2 minutes 54 seconds to 32 minutes 12 seconds per case. The mean diagnostic accuracy for telepathology diagnosis was 95%, with 2 of 3 observers achieving 100% diagnostic accuracy. Image quality was judged to be sufficient for correct evaluation, and the viewing times required to establish a final diagnosis by remote video microscopy were acceptable. Generally, user acceptance of robotic telepathology was high.


Assuntos
Técnicas de Diagnóstico Neurológico , Neoplasias do Sistema Nervoso/diagnóstico , Consulta Remota/métodos , Robótica/métodos , Telepatologia/métodos , Adolescente , Adulto , Idoso , Criança , Estudos de Viabilidade , Feminino , Alemanha , Humanos , Internet , Masculino , Microscopia/instrumentação , Microscopia/métodos , Pessoa de Meia-Idade , Inclusão em Parafina , Polônia , Distribuição Aleatória , Reprodutibilidade dos Testes , Telepatologia/instrumentação , Estados Unidos
19.
Telemed J E Health ; 6(3): 297-302, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11110633

RESUMO

Many rural sites cannot afford a digitizer to digitize radiographic films and transmit them via a telemedicine network for review by a radiology specialist. This project tested the feasibility of using a consumer digital still camera to photograph radiographic images and transmit them via a telemedicine network to a consulting hub site. In this study, the feasibility of using a digital camera to photograph plain film radiographs of 40 bone trauma cases from a rural health center in Arizona was tested. The cases were transmitted to the Arizona Telemedicine Program hub site using a private asynchronous transfer mode network based on T1 carriers. Two orthopedic surgeons and two radiologists reviewed the cases on a color monitor and the original film images. The readers also rated image quality. There were no significant differences in diagnostic accuracy between conventional film and telemedicine reading. Diagnostic agreement between film and monitor viewing was quite high, as was agreement in confidence ratings. Image quality was generally rated as excellent to good in both viewing conditions. Cases that did not correlate well were judged to have poor image quality, or diagnoses were based on photographs that had part of the diagnostic region of interest cropped off. It was determined that a digital still camera can be used effectively in many cases to photograph radiographic images for transmission and viewing via a telemedicine network, as long as adequate views, zoomed in regions of interest, and good quality original films are used in the acquisition process.


Assuntos
Redes de Comunicação de Computadores/instrumentação , Fotografação/instrumentação , Telerradiologia/instrumentação , Arizona , Apresentação de Dados , Reações Falso-Negativas , Reações Falso-Positivas , Estudos de Viabilidade , Humanos , Curva ROC , Serviços de Saúde Rural , Telerradiologia/normas
20.
Am J Med ; 108(2): 153-64, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11126309

RESUMO

During normal bone remodeling, the rate of supply of new osteoblasts and osteoclasts and the timing of the death of osteoclasts, osteoblasts, and osteocytes by apoptosis are critical determinants of the initiation of new BMUs and the extension or reduction of the lifetime of existing ones. Disruption of the fine balance among these processes may be an important mechanism behind the deranged bone turnover found in most metabolic disorders of the adult skeleton. Like most armies, the amount 5 of work done by bone cells is far more dependent on numbers than vigor. Therapeutic agents that alter the prevalence of apoptosis of osteoblasts and osteoclasts can correct the imbalance in cell numbers that is the basis of the diminished bone mass and increased risk of fractures in osteoporosis.


Assuntos
Apoptose , Osteoporose/patologia , Corticosteroides/efeitos adversos , Animais , Anti-Inflamatórios/efeitos adversos , Regeneração Óssea/efeitos dos fármacos , Remodelação Óssea/efeitos dos fármacos , Humanos , Osteonecrose/induzido quimicamente , Osteoporose/tratamento farmacológico , Osteoporose/etiologia , Osteoporose/prevenção & controle , Osteoporose Pós-Menopausa/patologia , Prednisona/efeitos adversos
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