RESUMO
OBJECTIVES: Muscular forces are an important determinant of bone strength, but bone may also adapt to non-muscular loading. We tested the hypothesis that loads associated with childhood gymnastics yield high arm bone mass (BMC), bone size and bone strength, independent of arm lean mass (FFM) and muscle cross-sectional area (CSA). METHODS: Total body DXA and distal radius pQCT scans were performed on 33 post-menarcheal girls (19 ex/gymnasts, 14 non-gymnasts). Physical activity and calcium intake were assessed by questionnaire. For the non-dominant arm, pQCT measured bone strength indices and bone CSA (total, cortical) (4%, 33% sites); DXA measured arm FFM, arm BMC and skull BMC. Multiple regression analyses assessed gymnastic exposure, arm FFM, gynecological age and stature as predictors of bone parameters. RESULTS: Bone outcomes at loaded upper extremity sites were 10-42% greater in ex/gymnasts than non-gymnasts. Gymnastic exposure remained a consistent, significant predictor of upper extremity skeletal parameters after accounting for the effects of muscle parameters, gynecological age and height. CONCLUSIONS: Considering the effects of either arm FFM or muscle CSA, indices of bone mass, geometry and theoretical strength are disproportionately elevated after gymnastic exposure. Thus, non-muscular loading may be a distinct and important determinant of human skeletal structure.
Assuntos
Osso e Ossos/anatomia & histologia , Osso e Ossos/fisiologia , Ginástica , Músculo Esquelético/anatomia & histologia , Resistência à Tração , Extremidade Superior , Adolescente , Anatomia Transversal , Densidade Óssea , Osso e Ossos/metabolismo , Feminino , Humanos , Tamanho do Órgão , Estresse Mecânico , Magreza , Tomografia Computadorizada por Raios X/métodos , Suporte de CargaRESUMO
Alendronate (ALN) and other bisphosphonates have been used successfully in pediatric patients with osteopenia secondary to connective tissue diseases. Loss of growth in height has not been reported, but concerns remain regarding the effect of these potent antiresorptive agents when used in children and adolescents. High-dose methotrexate (MTX) and other chemotherapy drugs have been implicated in osteoporosis and a high fracture incidence in survivors of childhood cancers and are also associated with osteopenia in adult animals. The effect of high dose MTX on bone density during rapid skeletal growth, however, has not been widely studied, nor has the potentially therapeutic effect of bisphosphonates in this setting. We examined the effects of ALN and MTX administration, alone and in combination, on bone density, morphology, mechanical strength, and longitudinal growth in normal growing rats. Sprague-Dawley rats were given ALN once weekly (0.3 mg/kg) from 5 to 11 weeks of age, with and without a course of methotrexate (MTX) given daily in weeks 1 and 3 (0.75 mg/kg/day). Twenty-four animals were randomly divided into four groups: Control (vehicle), ALN alone, ALN + MTX, and MTX alone. After 6 weeks, the femora, tibiae, and lumbar spine were studied by dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, mechanical strength testing, microradiography, light microscopy, and by determination of ash weights and bone lengths. ALN treatment increased bone mineral density (BMD) by 23% to 68%. The largest increases in the femur occurred in the distal third where endochondral bone growth was greatest and included large increases in trabecular bone and total cross-sectional area. ALN + MTX produced similar effects to ALN alone. MTX only reduced BMD by 8% in the vertebrae, but not significantly at other sites. MTX also led to femoral length reductions of 2.9%. The small reductions in BMD due to MTX were overwhelmed by the increases due to ALN, whereas the length loss was unaffected. Transverse density banding corresponding to weekly ALN administrations were clearly evident radiographically throughout the growing skeleton, likely due to decreased resorption and possibly increased mineralization in the bands. ALN or ALN + MTX treatment also led to increases in mechanical strength in the femora. Although MTX administration during growth leads to some BMD reduction, ALN given with MTX eliminates this reduction and in fact bone density and strength increase above control levels.
Assuntos
Alendronato/farmacologia , Conservadores da Densidade Óssea/farmacologia , Densidade Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Metotrexato/toxicidade , Alendronato/administração & dosagem , Animais , Osso e Ossos/patologia , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
The aim of this study was to determine the independent and combined effects of 100 mg/kg and 200 mg/kg doses of the radioprotectant amifostine and radiotherapy dose fractionation in preserving the integrity of or minimizing damage to the physis during high-dose radiation exposure in an animal model. Thirty-six weanling four-week-old male Sprague-Dawley rats were randomized into six study groups of six animals each. The distal femur and proximal tibia in the right leg of each animal was exposed to X-irradiation, with the contralateral left leg serving as the nonirradiated control. Three groups received a single 25 Gy radiotherapy dose: one group alone, a second group preceded by 100 mg/kg amifostine, and a third preceded by 200 mg/kg amifostine. Three groups received a total of 25 Gy in three equal fractions: one group alone, a second group preceded by 100 mg/kg amifostine, and a third preceded by 200 mg/kg amifostine. Fractionation of the 25 Gy radiation dose reduced the mean percent overall limb growth loss to 44.8%, a statistically significant reduction compared to a mean 58.8% reduced growth with the single 25 Gy dose. Addition of amifostine at 100 and 200 mg/kg before each of the three fractions of radiotherapy further decreased the mean percent overall limb growth loss to 35.2% and 28.5%, respectively, both statistically significant reductions beyond that achieved by fractionation alone.
Assuntos
Amifostina/farmacologia , Desenvolvimento Ósseo/efeitos dos fármacos , Desenvolvimento Ósseo/efeitos da radiação , Protetores contra Radiação/farmacologia , Animais , Fracionamento da Dose de Radiação , Relação Dose-Resposta a Droga , Fêmur/crescimento & desenvolvimento , Fêmur/efeitos da radiação , Masculino , Modelos Animais , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Tíbia/crescimento & desenvolvimento , Tíbia/efeitos da radiaçãoRESUMO
PURPOSE: The purpose of this study was to determine the relative benefits of sparing longitudinal bone growth by fractionation alone compared to pretreatment with amifostine, a chemical that provides differential radioprotection of normal tissues. METHODS AND MATERIALS: Twenty-four weanling 4-week-old male Sprague-Dawley rats were randomized into 2 overall treatment groups: fractionation alone (n = 12) and amifostine pretreatment (n = 12). The distal femur and proximal tibia in the right leg of each animal were exposed to a therapeutic X-irradiation dose (17.5 Gy total in 3 or 5 fractions) with the contralateral left leg as control. In 12 of the animals, amifostine (100 mg/kg) was administered intraperitoneally 20 min before radiation exposure. Six weeks later, growth was calculated based upon measurement of the bone lengths. RESULTS: Fractionated radiation resulted in a mean percent overall limb growth loss of 21. 1 +/- 7.0%. The addition of amifostine brought the mean percent overall limb growth loss to 16.3% +/- 4.6%, which showed a strong trend toward significance compared to fractionation alone (p = 0. 061). The addition of radioprotection with amifostine to 5 fractions irradiation significantly reduced the femoral and overall percentage growth arrest and limb length discrepancy compared to 5 fractions alone. CONCLUSIONS: These results support further investigation of amifostine and other radioprotectants in combination with fractionation for use in growing children requiring radiotherapy to the extremity for malignant tumors.
Assuntos
Amifostina/farmacologia , Desenvolvimento Ósseo/efeitos da radiação , Fracionamento da Dose de Radiação , Fêmur/efeitos da radiação , Lesões por Radiação/prevenção & controle , Protetores contra Radiação/farmacologia , Tíbia/efeitos da radiação , Animais , Fêmur/crescimento & desenvolvimento , Desigualdade de Membros Inferiores/prevenção & controle , Masculino , Radiobiologia , Ratos , Ratos Sprague-Dawley , Tíbia/crescimento & desenvolvimentoRESUMO
This experiment was aimed at illuminating the relationship between electromagnetic and mechanical stimuli of bone formation when present simultaneously. Movable and stationary intramedullary wire implants were studied in rabbits treated with a pulsing electromagnetic field (PEMF) 4 h/day for 3 weeks, and were compared with identical control animals without PEMF. Trabecular bone formed routinely at spontaneously movable implants, but not at stationary ones. On average, PEMF-treated movable implants in the femur induced 44% more bone than untreated movable implants. Also, in the PEMF-treated femora, a 22% enlargement of the area of the medullary canal was observed compared with no-field controls. In the tibia, these effects were weak or nonexistent. The PEMF used did not induce bone at stationary implants, suggesting that under these conditions it is not a primary trigger in vivo.
Assuntos
Fenômenos Eletromagnéticos , Fêmur/fisiologia , Osteogênese , Próteses e Implantes , Tíbia/fisiologia , Animais , Fêmur/patologia , Movimento (Física) , Coelhos , Tíbia/patologiaRESUMO
The osteogenesis induced in the medullary canal of rabbits by the implantation of moving and stationary wire electrodes was studied with and without the simultaneous application of 20-microA constant direct cathodic current. After 3 weeks, the formation of new trabecular bone in the canal was studied and measured microscopically. Electrically stimulated osteogenesis was not observed at stationary electrodes. As in previous studies with this model, a movable electrode alone stimulated new bone formation whose area was 7-10% of the canal area. The amount of this bone was not statistically increased by the addition of cathode current. Movable, electrically active cathodes were associated, however, with fluid-filled spaces incorporated within the new trabecular bone. When mechanical stimuli were controlled, we were not able to demonstrate that the direct current stainless steel cathode acts either as an inducer or a substantial enhancer of medullary osteogenesis.
Assuntos
Eletrodos , Osteogênese/fisiologia , Análise de Variância , Animais , Desenvolvimento Ósseo/fisiologia , Condutividade Elétrica , Estimulação Elétrica , Fêmur/citologia , Fêmur/fisiologia , Modelos Biológicos , CoelhosRESUMO
The radioprotectant compound amifostine (S-2[3-aminopropylamino]-ethylphosphorothioic acid), administered prior to radiotherapy, has been demonstrated to provide differential protection of normal cells from the damaging effects of ionizing radiation. The aim of this pilot was to determine if amifostine could preserve the integrity of, or minimize the damage to, the physis during exposure to radiation in an animal model. Thirty weanling Sprague-Dawley rats were randomized into five groups of six animals each. Groups 1 and 2 received a single exposure to radiation consisting of 12.5 and 17.5 Gy, respectively. Groups 3 and 4 received similar exposures of 12.5 and 17.5 Gy, respectively, but with prior administration of amifostine at 100 mg/kg. Group 5 (control) received neither radiation nor amifostine. At 6 weeks, femoral and tibial lengths were measured in treated and untreated hindlimbs and compared with the baseline lengths to calculate growth. Concordant with previous reports in the literature, the radiation doses of 12.5 and 17.5 Gy reduced net femoral growth in length by a mean of 23% (range = 12-33%, SD = 7.41) and 59% (range = 54-64%, SD = 4.45), respectively, in the irradiated limb. Amifostine reduced anticipated growth loss normally resulting from a single 12.5-Gy radiation dose by 48.9% in the femur, 13.1% in the tibia, and 27.6% overall in the total limb (p < or = 0.05). Similarly, anticipated growth loss from a single 17.5-Gy radiation dose was reduced by 30.8% in the femur, 20.3% in the tibia, and 25.7% overall in the total limb (p < or = 0.05). Amifostine administered prior to clinically relevant radiation exposures significantly reduced the amount of anticipated growth arrest in our animal model.
Assuntos
Amifostina/uso terapêutico , Lâmina de Crescimento/efeitos da radiação , Lesões Experimentais por Radiação/prevenção & controle , Protetores contra Radiação/uso terapêutico , Amifostina/farmacologia , Animais , Desenvolvimento Ósseo/efeitos dos fármacos , Desenvolvimento Ósseo/efeitos da radiação , Modelos Animais de Doenças , Fêmur/efeitos dos fármacos , Fêmur/crescimento & desenvolvimento , Fêmur/efeitos da radiação , Lâmina de Crescimento/efeitos dos fármacos , Lâmina de Crescimento/crescimento & desenvolvimento , Membro Posterior/efeitos dos fármacos , Membro Posterior/crescimento & desenvolvimento , Membro Posterior/efeitos da radiação , Projetos Piloto , Protetores contra Radiação/farmacologia , Ratos , Ratos Sprague-Dawley , Tíbia/efeitos dos fármacos , Tíbia/crescimento & desenvolvimento , Tíbia/efeitos da radiação , Raios XRESUMO
Previous experiments have suggested that mechanical activity of electrode implants may contribute to the observed bone formation that has been attributed to the electrical currents. This was tested by implanting movable and stationary wires in the medullary canal of the rabbit femora or tibiae. The moving implants uniformly showed significant medullary bone formation at the wire, whereas the stationary ones did not. This bone persisted for as long as 8 weeks and was mostly resorbed by 12 weeks as the implants became fixed. The new trabecular bone closely resembled that typically seen at electrically active implants. Implant motion may have a more important role in electrically induced osteogenesis than previously thought.
Assuntos
Osteogênese , Animais , Fios Ortopédicos , Osso e Ossos/anatomia & histologia , Osso e Ossos/diagnóstico por imagem , Estimulação Elétrica/métodos , Eletrodos Implantados , Fêmur , Estimulação Física/métodos , Coelhos , Radiografia , Tíbia , Fatores de TempoRESUMO
The factors leading to overgrowth following fixation of long-bone fractures in children have never been clearly understood. The amount of trauma and the type of fixation may play a role. A rabbit model was used to investigate the influence of a femoral osteotomy and plate fixation on subsequent growth. Unilateral midshaft femoral osteotomy was performed in 6-week-old rabbits, and the bone was fixed internally with a plate and screws. End-to-end reduction was performed either at full length or with a segment removed. Bone length measurements at the end of growth revealed no significant difference in growth between the control femur and the femur that had undergone osteotomy and plate fixation. Shortened plated femora also showed no tendency to grow longer or faster than full-length fixed femora or controls. Interestingly, in the ipsilateral tibia a small but statistically significant length increase, equivalent to about 2% increase in additional growth, was observed, whereas technetium-99 methylene diphosphonate uptake was reduced in the tibial physes. In the context of the rabbit experimental model chosen, these results suggest that significant femoral over-growth does not occur following femoral osteotomy and plate fixation.
Assuntos
Animais Recém-Nascidos/crescimento & desenvolvimento , Desenvolvimento Ósseo , Fixadores Internos , Osteotomia , Animais , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/metabolismo , Coelhos , Radiografia , Cintilografia , Tecnécio/farmacocinética , Distribuição TecidualRESUMO
Fractures of the distal radius are common, especially in postmenopausal women, and their prevalence increases with age. Knowledge of the factors that increase the risk of fracture in this metaphyseal region would have predictive and therapeutic implications. Of particular interest in this study were (a) the relative contributions of cortical and trabecular bone to the strength of the distal radius and (b) the best radiographic features to use as strength indicators. In 21 forearms from fresh cadavera (median age at the time of death, 75 years), single photon absorptiometry and quantitative computed tomography were used to determine bone mineral content (BMC), density (BMC/W), and cross-sectional properties of the radius at distal and midshaft sites. Mechanical testing of the forearms then was used to determine the ultimate force and energy to cause the type of fracture that might be caused by a fall on the outstretched hand. Twelve of the 17 tested specimens sustained a fracture of the distal radius, and five sustained a fracture of the scaphoid. In the group of fractures of the distal radius, we found the cross-sectional area and moment of inertia of the cortical shell at the metaphyseal site to be better correlates of strength than the trabecular area and trabecular moment. In contrast, strength correlated much better with trabecular density than with cortical density. Overall, the best correlates of strength were the BMC and BMC/W at either the distal or proximal site. On balance, these results suggest that the thin cortical shell contributes substantially more to the mechanical strength of the distal radius than has been commonly appreciated.
Assuntos
Doenças Ósseas Metabólicas/etiologia , Rádio (Anatomia)/fisiologia , Idoso , Densidade Óssea , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
PURPOSE: To determine if pentoxifylline, interleukin 1alpha, selenium and misoprostol can minimize damage to physeal longitudinal growth during single radiation dose exposure in an animal model. MATERIALS AND METHODS: Eighty-seven weanling Sprague-Dawley rats were randomized into 15 drug/dose groups. All groups received a single 17.5-Gy gamma-irradiation exposure to the right knee, the left limb serving as an internal control. Pentoxifylline was injected 30 min before exposure, sodium selenite and interleukin 1alpha 24 h before exposure and misoprostol 2 h before exposure. Positive controls received 17.5 Gy. At 6 weeks, animals were sacrificed, the hind limb lengths were measured and detailed histomorphometric analysis was performed. RESULTS: Statistically significant reductions (p < or = 0.03) in mean limb length discrepancy compared with irradiation alone were seen following administration of pentoxifylline (50 mg kg(-1)), interleukin 1alpha (15 mcg kg(-1)), selenium (5 mg kg(-1)) and misoprostol (20 mg kg(-1)). Histomorphometric endpoints and growth rate remained altered at 6 weeks despite treatment, but length discrepancy reduction was highly correlated with the appearance of regenerative clones. CONCLUSIONS: Each drug reduced the amount of anticipated growth arrest in the animal model and some compared favourably in magnitude with that previously demonstrated for the established radioprotectant drug amifostine. Restoration of growth appears related to appearance of regenerative clones.
Assuntos
Desenvolvimento Ósseo/efeitos dos fármacos , Desigualdade de Membros Inferiores/prevenção & controle , Protetores contra Radiação/farmacologia , Animais , Desenvolvimento Ósseo/efeitos da radiação , Regeneração Óssea/efeitos dos fármacos , Regeneração Óssea/efeitos da radiação , Interleucina-1/farmacologia , Ossos da Perna/efeitos dos fármacos , Ossos da Perna/efeitos da radiação , Desigualdade de Membros Inferiores/etiologia , Masculino , Misoprostol/farmacologia , Modelos Animais , Pentoxifilina/farmacologia , Lesões Experimentais por Radiação/fisiopatologia , Ratos , Ratos Sprague-Dawley , Selênio/farmacologiaRESUMO
PURPOSE: The use of protective equipment has been absent or inconsistent in scholastic women's lacrosse leading to increasing concern for eye and head injury. There is a paucity of field data, however, on which to base strategic decisions on how best to prevent head injuries in young athletes. METHODS: This study examined the effects of protective eyewear on injury rates in scholastic women's lacrosse in a cohort of approximately 700 varsity and junior varsity players in central New York studied prospectively for 2 yr during a transition from sparse to almost complete eyewear use. RESULTS: The overall head/face injury rate was 0.71 injuries per 1000 exposures (games and practices) and was 16.5% lower in goggle wearers. In games alone, where more aggressive play and stick use prevails, the rate associated with protective eyewear use was markedly lower (51%). Considering specific regions, the rates for peri-orbit and forehead injuries among goggle users were substantially lower than for nonusers (6% and 13%, respectively). Cheek and scalp injury rates tended to be higher among goggle wearers, but not statistically significantly so. Significant compensatory increases with goggle wear at other sites were not observed. Only a few injuries appeared to be mediated by the goggles themselves and potentially could have been more serious if the goggles had not been present. No direct eye (orbit) injuries were reported throughout the study period. CONCLUSION: On balance, then, the use of eyewear in women's lacrosse appears to be beneficial when users are compared with nonusers.
Assuntos
Traumatismos Craniocerebrais/prevenção & controle , Dispositivos de Proteção dos Olhos , Traumatismos Faciais/prevenção & controle , Esportes com Raquete/lesões , Adolescente , Distribuição de Qui-Quadrado , Traumatismos Craniocerebrais/epidemiologia , Traumatismos Craniocerebrais/etiologia , Traumatismos Faciais/epidemiologia , Traumatismos Faciais/etiologia , Feminino , Humanos , New York/epidemiologia , Estudos ProspectivosRESUMO
Electrically generated silver ions have been shown previously to be a potent antibacterial agent with an exceptionally broad spectrum as indicated by in vitro testing. The present study reports on clinical experience using electrically generated silver ions as adjunctive treatment in the management of chronic osteomyelitis. Fourteen patients had fifteen treatment attempts: thirteen for chronic osteomyelitis of the tibia, one for acute and chronic pyarthrosis and osteomyelitis of the knee, and one for a chronically draining sinus after total hip replacement. Wound débridement, silver ion iontophoresis, and subsequent wound care (usually provided by the patient) resulted in control of the infection in twelve of the fifteen treatment attempts and in healing of the non-union after follow-up ranging from three to thirty-six months. The other three attempts led to two partial and one complete failure.
Assuntos
Anti-Infecciosos Locais/uso terapêutico , Fraturas Ósseas/complicações , Osteomielite/tratamento farmacológico , Prata/uso terapêutico , Adulto , Anti-Infecciosos Locais/administração & dosagem , Desbridamento , Avaliação de Medicamentos , Eletrodos , Feminino , Seguimentos , Fraturas Ósseas/microbiologia , Humanos , Íons , Iontoforese , Masculino , Pessoa de Meia-Idade , Nylons , Osteomielite/microbiologia , Osteomielite/cirurgia , Prata/administração & dosagem , CicatrizaçãoRESUMO
Low-intensity pulsed ultrasound recently has been shown to accelerate long bone fracture healing, but its effect on bone growth and development is unknown. The longitudinal growth and bone density of the femur and tibia in young rats was measured after application of an ultrasound transducer emitting 1.5-MHz pulsed ultrasound (30 mW/cm2, SATA) for 20 min/day. After 28 days, no length difference was detected (< or = 2%) compared to the sham-treated leg or to unexposed controls. Also, no significant difference in bone mineral density (BMD) of the femur or tibia was found (< or = 6%). In a repeated experiment in which a periosteal trauma stimulus was created in the femoral diaphysis, the ultrasound also had no effect on growth or BMD. This results suggests that physeal bone growth is far less sensitive to this level of ultrasound application than is fracture repair. This may be related to the cascade of cellular events and regulatory factors that are present after a fracture.
Assuntos
Fêmur/crescimento & desenvolvimento , Tíbia/crescimento & desenvolvimento , Ultrassom , Absorciometria de Fóton , Análise de Variância , Animais , Peso Corporal , Densidade Óssea , Fêmur/diagnóstico por imagem , Masculino , Ratos , Ratos Sprague-Dawley , Temperatura , Tíbia/diagnóstico por imagemRESUMO
The somatosensory cortical evoked potentials recorded during posterior spine fusion and instrumentation for 99 consecutive patients with idiopathic scoliosis, 18 years of age or younger, were retrospectively reviewed. The potentials were recorded from scalp electrodes while synchronously stimulating both tibial nerves near the ankles. Signal changes observed during consecutive 30-minute time intervals after deformity correction were analyzed. No changes in neurologic status were observed postoperatively. Latency values tended to remain constant on average. A small, but statistically significant, decrease in the first two interpeak amplitudes was observed during the first 30-minute interval after deformity correction. The first interpeak amplitude recovered, while the second remained statistically significantly decreased. No patient had a decrease of greater than 50% in both of the first two amplitudes, which persisted throughout the 60-minute interval immediately after deformity correction. This study demonstrated a tendency for somatosensory cortical evoked potential interpeak amplitudes to decrease during the first 30 minutes after deformity correction. There was a great deal of individual variation, including amplitude increases in many patients. There was no evidence supporting an association between dramatic, sustained amplitude decreases and uncomplicated deformity correction. The value of thoroughly evaluating somatosensory cortical evoked potential signal trends while making intraoperative decisions is emphasized.
Assuntos
Artrodese , Potenciais Somatossensoriais Evocados/fisiologia , Escoliose/fisiopatologia , Humanos , Estudos Retrospectivos , Escoliose/cirurgia , Medula Espinal/fisiopatologiaRESUMO
The intraoperative variability of somatosensory cortical evoked potentials (SCEPs) has been measured for 320 consecutive spinal surgeries and found to be a function of patient diagnosis, neuromuscular status, age, and procedural factors. In many cases, it is likely that this variability severely limits the reliability and usefulness of spinal cord monitoring in detecting early cord compromise. Patients with idiopathic scoliosis, spondylolisthesis, and pseudarthrosis have the smallest spontaneous variability and strongest amplitudes, while those with congenital, paralytic scoliosis, stenosis, or tumor have very variable, weak SCEPs. Patients with neurologic disorders, particularly cerebral palsy, myelomeningocele, Friedreich's ataxia, and peripheral deficits, also have high variability and weak amplitudes. A monitoring quality scoring system is proposed that may be useful during surgery in judging how well the SCEPs can discern surgically related changes in cord function from background variations.
Assuntos
Potenciais Somatossensoriais Evocados , Monitorização Fisiológica/métodos , Traumatismos da Medula Espinal/prevenção & controle , Fusão Vertebral , Adulto , Idoso , Anestesia Geral , Humanos , Cuidados Intraoperatórios , Pessoa de Meia-Idade , Fatores de TempoRESUMO
Silver has had a widespread application in the care of burn wounds and chronic skin ulcers. The in vitro evaluation of unbound ionic silver is reported in this study. A comparison is made between silver-coated fabric alone and the fabric acting under direct electric current anodization. A variety of commonly found predominant skin pathogens were tested in this comparative study. Our studies confirm previous reports demonstrating an effective penetration of the silver ion and its local antibacterial action. Accurate measurements of the bacteria-free "clear zones" surrounding the electrically activated silver-coated fabric showed these to be significantly larger than those of the silver fabric without electric stimulation. This method affords another option in the use of silver for its antibacterial property, i.e., by iontophoresis. Its potential clinical use awaits further in vivo trials.