Tridimensional localization of bone and soft tissue injuries in complex facial trauma is fundamental for treatment. The face can be conceptualized as 3 groups of interconnected osseous struts that are oriented in the horizontal, sagittal and coronal planes. Each group of struts is closely related to specific soft tissue structures that are susceptible to injury. Any single CT section in the coronal plane or in the axial plane contains parts of one or more these struts. Facial CT in biplane were performed in 32 patients of facial trauma. The most common site of facialfractures is found in middle part of horizontal struts, geometrically in anteromedial portion of the inferior orbital fissure of the face. The most common soft tissue injury combined with facialfracture is hematoma and/or herniated orbital contents into the ...
This book provides an analysis of pathophysiologic concepts of trauma and reviews the effectiveness of the available imaging modalities in acute trauma of various organ system. Topics covered are chest injuries; abdominal trauma; fractures of long bones; the foot and ankle; the knee; hand and wrist; the elbow; the shoulder; the pelvis hips; the spine; the skull and facial trauma and the clinical assessment of multiple injuries patients. Comparative evaluation of diagnostic techniques of radiography is discussed. Normal anatomy and bonefractures along with soft-tissue injuries are described.
Thirty-five patients with temporal bonefractures were examined; the fractures were sometimes associated with dislocation of the assicular chain caused by road fatalities. Computed Tomography (CT) was performed either because of the presence of clinical symptoms associated with trauma of the temporal bone, because of a hemotympanum discovered during a CT scan of the brain. Thirty-three fractures were detected: 19 longitudinal, 6 transverse, and 8 complex. An incudostapedial dislocation was also detected, together with a displacement of a stapedial prosthesis from the lenticular process of incus, and 3 incus-malleus dislocation associated with fractures. High resolution CT allows the precise definition of the course of the fractures, of the associated dislocation of the ossicular chain, and of facial nerve lesion, thus ...
Computed tomography allows today to reconstruct three-dimensional (eD) images fram axial scans. The authors report their experience in cranio-facial pathology achived in two Departments of Radiology (University of Trieste, Italy and University of Standford, California). 3D images have been realized using two different softwares, one of which allows to reconstruct both soft tissue and bone structures. The application in maxillo-facial traumas, cranio-facial malformations and head tumours are disscussed. 3D images turned out to be very useful for the optimal visualization and for the spatial demostration of the lesion and have potential applications in cranio-facial surgery and radiotherapy.
The authors present a guide to the imaging of facialfractures. It is illustrated with conventional radiographs and computed tomograms; the magnetic resonance images primarily suggest the potential applications of this technique. This book provides a source of imaging information on facial trauma. A section on pertinent anatomy is followed by a systematic discussion of the common isolated and complex facialfractures. Perspectives are offered on some commonly seen but infrequently described relationships, such as the tripod-LeFort II association. Consideration is also given to related soft-tissue injuries. The book includes a brief chapter on the type and utility of supplementary imaging studies in the evaluation of those intracranial injuries that may occur concurrently.
Bone mineral density is considered to be the standard measure for the diagnosis of osteoporosis and the assessment of fracture risk. The majority of fragility fractures occur in patients with bone mineral...Full Text Available
A mechanistic understanding of fracture in human bone is critical to predicting fracture risk associated with age and disease. Despite extensive work, a mechanistic framework for describing how the underlying microstructure affects the failure mode in bone is lacking.
Failure of bone under monotonic and cyclic loading is related to the bone mineral density, the quality of the bone matrix and the evolution of microcracks. The theory of linear elastic fracture...Full Text Available
Current drug treatments for post-menopausal osteoporosis cannot eliminate bonefractures, possibly because the mechanisms responsible for bone loss are not fully understood. Although research within...Full Text Available
Background:The present study measured longitudinal changes in bone turnover markers in elderly patients with vertebral fracture and investigated the relationship among bone turnover...Full Text Available
Recessive inactivating mutations in human matrix metalloproteinase 2 (MMP2, gelatinase A) are associated with syndromes that include abnormal facial appearance, short stature, and severe bone...Full Text Available
sup(99m)Tc-MDP bone scintigraphy was performed on patients who received muscle-pedicle bone graft. In each of the bone head and the bone graft, a time-activity curve was obtained. In this muscle-pedicle bone graft, active revascularization and marked osteogenesis, which suggested rapid bone repairing, were observed. The bone scintigraphy was considered to be useful in observing the result of bone grafts, blood circulation, and time of bone fusion, and of value for early detection of secondary changes.
A micro-mechanistic understanding of bonefracture thatencompasses how cracks interact with the underlying microstructure anddefines their local failure mode is lacking, despite extensive research nthe response of bone to a variety of factors like aging, loading, and/ordisease.
A micro-mechanistic understanding of bonefracture that encompasses how cracks interact with the underlying microstructure and defines their local failure mode is lacking, despite extensive research on the response of bone to a variety of factors like aging, loading, and/or disease. Micro-mechanical models for fracture incorporating such local failure criteria have been widely developed for metallic and ceramic materials systems; however, few such deliberations have been undertaken for the fracture of bone. In fact, although the fracture event in mineralized tissues such as bone is commonly believed to be locally strain controlled, until recently there has been little experimental evidence to support this widely held belief. In the present study, a series of in vitro experiments involving a double-notch bend test ...
The hierarchical arrangement of collagen and mineral into bone tissue presumabley maximizes fracture resistance with respect to the predominant strain mode in bone. Thus, the ability of cortical...Full Text Available
Twenty-six patients with late complications following femoral neck fracture were examined with both skeletal and bone marrow radionuclide scintimetry. There was no correlation between the methods with respect to the quantitative assessment of femoral head vascularity based on different uptake ratios comparing the fractured and the intact side. Skeletal scintimetry always had good image quality and permitted reliable differentation between nonunion of the fracture and late segmental collapse, in contrast to bone marrow scintimetry which gave poor image quality. Skeletal scintimetry thus seems superior to bone marrow scintimetry for assessment and differential diagnosis of late complications following femoral neck fracture. It is emphasized that the physiological mechanisms for radionuclide uptake must be taken into account when comparing ...
Twenty-six patients with late complications following femoral neck fracture were examined with both skeletal and bone marrow radionuclide scintimetry. There was no correlation between the methods with respect to the quantitative assessment of femoral head vascularity based on different uptake ratios comparing the fractured and the intact side. Skeletal scintimetry always had good image quality and permitted reliable differentation between nonunion of the fracture and late segmental collapse, in contrast to bone marrow scintimetry which gave poor image quality. Skeletal scintimetry thus seems superior to bone marrow scintimetry for assessment and differential diagnosis of late complications following femoral neck fracture. It is emphasized that the physiological mechanisms for radionuclide uptake must be taken into account when comparing ...
Purpose: In an experimental study, the correlation between the trabecular bone density of the different regions of the proximal femur and the fracture load in the setting of femoral neck fractures was examined. Methods: The bone mineral density 41 random proximal human femora was estimated by single-energy quanitative CT (SE-QCT). The trabecular bone density was measured at the greatest possible extracortical volume at midcapital, midneck and intertrochanteric level and in the 1 cm"3 volumes of the centres of these regions in a standardised 10 mm thick slice in the middle of the femoral neck axis (in mg/ml Ca-hydroxyl apatite). The proximal femora were then isolated and mounted on a compression/bending device under two-legged stand conditions and loaded up to the point when a femoral neck fracture occurred. Results: Statistical analysis revealed a linear ...
In the past decade, we have witnessed a revolution in osteoporosis diagnosis and therapeutics. This includes enhanced understanding of basic bone biology, recognizing the severe consequences of fractures...Full Text Available
BackgroundBallet Dancers have been shown to have a relatively high incidence of stress fractures of the foot and ankle. It was our objective to examine MR imaging patterns of bone...Full Text Available
We treated 13 patients for femoral neck fracture. They consisted of 2 males and 11 females, and were classified according to Garden stage classification; Stage I, 3 cases; Stage II, 2 cases; Stage III, 2 cases; Stage IV, 4 cases. Two trochanteric fracture cases were used by control. We evaluated perfusion of the femoral head after femoral neck fracture using bone scintigraphy, which is considered useful for evaluation of perfusion of the femoral neck before operation. (author)
Age-related deterioration of the fracture properties of bone, coupled with increased life expectancy, are responsible for increasing incidence of bonefracture in the elderly, and hence, an understanding of how its fracture properties degrade with age is essential. The present study describes ex vivo fracture experiments to quantitatively assess the effect of aging on the fracture toughness properties of human cortical bone in the longitudinal direction. Because cortical bone exhibits rising crack-growth resistance with crack extension, unlike most previous studies the toughness is evaluated in terms of resistance-curve (R-curve) behavior, measured for bone taken from wide range of age groups (34-99 years). Using this approach, both the ex vivo crack-initiation and crack-growth ...
Background Fracture healing in osteoporosis is delayed. Quality and speed of fracture healing in osteoporotic fractures are crucial with regard to the outcome of patients. The question arises whether established antiosteoporotic drugs can further improve fracture healing. Materials and methods Osteoporosis manifests predominantly in the metaphyseal bone. Nevertheless, an established metaphyseal fracture model is lacking. A standardized metaphyseal fracture-healing model with stable plate fixation was developed for rat tibiae. The healing process was analyzed by biomechanical, gene expression, and histomorphometric methods in ovariectomized (OVX) and sham-operated rats (SHAM), compared to standardized estrogen (E)- and raloxifene (R)-supplemented diets. Results Estrogen and raloxifene impro...
The aim of this study was the evaluation of contralateral hip fractures after a previous hip fracture. For this retrospective analysis patients were selected from the database of the LUMC, a teaching hospital in the south-west of the Netherlands. We analyzed all patients with a second fracture of a hip between 1992 and 2007. The exclusion criteria were high impact trauma and patients with diseases or medication known to have a negative effect on bone metabolism. A total of 1,604 hip fractures were identified. The possible predictive factors for the second fracture and descriptive statistics related to surgery (Hb and HT before and after the operation, total amount of intra- and postoperative blood loss, type of osteosynthesis, complications, time of death after the last fracture, time betw...
The authors have evaluated bone mineral content in the vertebral spongiosa by means of Computed Tomography. The method proposed by Genant and Cann [17, 18] has been applied to examine 164 healthy volunteers and 108 patients. Both healthy males and females showed a progressive bone mineral loss increasing with age; the bone mineral loss was most severe in females during the 4th and 5th decade of life. Pathology included patients with osteoporotic fractures (vertebral and femural neck), patients with partial gastrectomy, renal failure, primary hyperparathyroidism, Cushing syndrome, corticosteroid therapy. Bone mineral values were significantly lower in most pathologic groups. Computed Tomography proves thus to be a valuable method to assess bone mineral content and to identify patients at risk for fractures.
This case report makes evident that in a 75 years old patient with a (cured) femoral neck fracture 15 years ago a refracture at the same site following a new trauma could not be detected by conventional X-ray. The follow-up of a radionuclide bone study, however, enabled the dignosis of a refracture. From these findings, it is further evident that the decreased bone metabolism in older patients has to be considered. Thus, although the initial bone scan following the trauma is negative, a follow-up scan should be performed within a 4 day-period.
This case report makes evident that in a 75 years old patient with a (cured) femoral neck fracture 15 years ago a refracture at the same site following a new trauma could not be detected by conventional X-ray. The follow-up of a radionuclide bone study, however, enabled the dignosis of a refracture. From these findings, it is further evident that the decreased bone metabolism in older patients has to be considered. Thus, although the initial bone scan following the trauma is negative, a follow-up scan should be performed within a 4 day-period. (orig.).
The viability of osteocytes can be demonstrated in sawn decalcified sections of bone by their lactate dehydrogenase activity. In the cancellous bone of the femoral head, the proportion of lacunae containing viable osteocytes decreased from 88 +/- 7% (mean +/- SD) at 10-29 years to 58 +/- 12% (P Ultimate compressive strength did not correlate with osteocyte viability. In the femoral head there is gradual, age-related reduction in osteocyte viability that can be more pronounced in hip fracture. Osteocyte death may affect bone quality by impairing repair of fatigue damage. PMID:8275364
Microdamage naturally occurs in bone tissue as a result of cyclic loading placed on the body from normal daily activities. While it is usually repaired through the bone turnover process, accumulation of microdamage may result in reduced bone quality and increased fracture risk. It is unclear whether certain areas of bone are more susceptible to microdamage than others due to compositional differences. This study examines whether areas of microdamaged bone are chemically different than undamaged areas of bone. Bone samples (L3 vertebrae) were harvested from 15 dogs. Samples were stained with basic fuchsin, embedded in poly-methylmethacrylate, and cut into 5-(micro)m-thick sections. Fuchsin staining was used to identify regions of microdamage, and synchrotron infrared microspectroscopic imaging was used to determine the ...
A large inguino-scrotal hernia was detected in the early phase of a radionuclide bone scan performed for evaluation of a femoral neck fracture not visualized on plain x-rays. The patient was administered 1 GBq of Scrotal scintigraphy using "9"9"mTc-MDP and a regional three-phase bone scan of the pelvis, hips and proximal femora was obtained on the gamma camera. Copyright (1999) Blackwell Science Pty Ltd
Our group is interested in evaluating early effects of dietary interventions on bone loss. Postmenopausal women lose bone following reduction in estrogen which leads to increased risk of fracture. Traditional means of monitoring bone loss and effectiveness of treatments include changes in bone density, which takes 6 months to years to observe effects, and changes in biochemical markers of bone turnover, which are highly variable and lack specificity. Prelabeling bone with {sup 41}Ca and measuring urinary {sup 41}Ca excretion with accelerator mass spectrometry provides a sensitive, specific, and rapid approach to evaluating effectiveness of treatment. To better understand {sup 41}Ca technology as a tool for measuring effective treatments on reducing bone resorption, we perturbed bone resorption by ...
We investigated the descriminative ability of total body bone-mineral expressed as the total body bone-density (TBBD) measured by dual photon absorptiometry (DPA) in 79 healthy premenopausal women, 27 healthy postmenopausal women, and 120 female osteoporotic fracture patients presenting with either Colles' fracture, vertebral fracture or femoral neck-fracture. TBBD was compared to the bone-mineral density of the lumbar spine (BMD{sub spine}) also measured by DPA, and to the bone-mineral content of the forearms (BMC{sub forearm}) measured by single photon absorptiometry (SPA). TBBD, BMD{sub spine} and BMC{sub forearm} showed that all the fracture patient groups had significantly reduced bone-mass. Using receiver operating characteristic (ROC) analysis, we found that TBBD ...
Over 300 cases of femoral neck fractures following radiotherapy for intrapelvic malignant tumor have been reported in various countries since Baensch reported this disease in 1927. In Japan, 40 cases or so have been reported, and cases of bilateral femoral neck fractures have not reached to ten cases. The authors experienced a case of 75 year-old female who received radiotherapy for cancer of the uterus, and suffered from right femoral neck fracture 3 months after and left femoral neck fracture one year and half after. As clinical symptoms, she had not previous history of trauma in bilateral femurs, but she complained of a pain in a hip joint and of gait disturbance. The pain in left femoral neck continued for about one month before fracture was recognized with roentgenogram. As histopathological findings, increase of fat marrow, decrease of bone trabeculae, and ...
AIM: To define the value of digital radiography with a clinical flat panel detector system for evaluation of wrist fractures in comparison with state of the art storage phosphor radiography. MATERIAL AND METHODS: Hard copy images of 26 fractured wrist specimens were acquired with the same exposure dose on a state of the art storage phosphor radiography system and a clinical flat panel detector. Image features like cortical bone surface, trabecular bone, soft tissues and fracture delineation were independently analysed by 4 observers using a standardised protocol. Image quality ratings were evaluated with an analysis of variance (ANOVA). RESULTS: Flat panel detector radiographs were rated superior with respect to cortical and trabecular bone representation as well as fracture evaluation, while storage phosphor radiographs produced better soft ...
AIM: To define the value of digital radiography with a clinical flat panel detector system for evaluation of wrist fractures in comparison with state of the art storage phosphor radiography. MATERIAL AND METHODS: Hard copy images of 26 fractured wrist specimens were acquired with the same exposure dose on a state of the art storage phosphor radiography system and a clinical flat panel detector. Image features like cortical bone surface, trabecular bone, soft tissues and fracture delineation were independently analysed by 4 observers using a standardised protocol. Image quality ratings were evaluated with an analysis of variance (ANOVA). RESULTS: Flat panel detector radiographs were rated superior with respect to cortical and trabecular bone representation as well as fracture evaluation, while storage phosphor radiographs produced better soft ...
BACKGROUND: Although definitions vary, infected nonunion has been defined as a state of failure of union and persistence of infection at the fracture site for 6 to 8 months.>). Infected nonunions of the supracondylar region of the femur are uncommon and are mostly due to a severe open fracture with extensive comminution and segmental bone loss or after internal fixation of a comminuted closed fracture. Associated factors include exposed bone devoid of vascularized periosteal coverage for more than 6 weeks, purulent discharge, a positive bacteriological culture from the depth of the wound, and histologic evidence of necrotic bone containing empty lacunae. Soft-tissue loss with multiple sinuses, osteomyelitis, osteopenia, complex deformities with limb-length inequality, stiffness of the adjacent joint, polybacterial multidrug-resistant infection, and smoking ...
The prospective study includes 25 patients without pathology of the femoral head for the evaluation of the normal femoral head perfusion. In addition 34 patients with femoral head necrosis underwent i.a. DSA preoperatively before pedicled pelvic bone grafting. 15 patients after pelvic bone graft operation and 7 patients with medial femoral head fracture were also examined via superselective DSA. In cases with femoral head necrosis a rarefaction or interruption of the rami nutricii proximales, or an occlusion of the medial circumflex femoral artery were observed. Patients with medial femoral neck fracture showed an interruption of the rami nutricii proximales of the femoral head. Postoperative DSA - after pedicled pelvic bone graft - revealed a regular arterial graft perfusion in 82%. (orig.).
IntroductionIrradiation of normal, non-malignant bone during cancer therapy can lead to atrophy and increased risk of fracture at several skeletal sites, particularly...Full Text Available
Hypothyroidism and thyrotoxicosis are each associated with an increased risk of fracture. Although thyroxine (T4) is the predominant circulating thyroid hormone, target cell responses are determined...Full Text Available
BackgroundDiet is considered an important factor for bone health, but is composed of a wide variety of foods containing complex combinations of nutrients. Therefore we investigated...Full Text Available
There is increasing evidence of a biochemical link between lipid oxidation and bone metabolism. Paraoxonase 1 (PON1) prevents the oxidation of low-density lipoprotein (LDL) and metabolizes biologically...Full Text Available
Posttraumatic tibia valga is a well-recognized complication following fracture of the upper tibial metaphysis in young children. We present a case of a child who developed a valgus deformity following fracture of the proximal tibia and fibula in which quantitative bone scintigraphy at 5 months after injury demonstrated increased uptake at the proximal tibial growth plate with proportionally greater uptake on the medial side. This finding suggests that the valgus deformity in this patient was due to a relative increase in vascularity and consequent overgrowth of the medial portion of the proximal tibial physis.
Posttraumatic tibia valga is a well-recognized complication following fracture of the upper tibial metaphysis in young children. We present a case of a child who developed a valgus deformity following fracture of the proximal tibia and fibula in which quantitative bone scintigraphy at 5 months after injury demonstrated increased uptake at the proximal tibial growth plate with proportionally greater uptake on the medial side. This finding suggests that the valgus deformity in this patient was due to a relative increase in vascularity and consequent overgrowth of the medial portion of the proximal tibial physis.
Muscular fatigue in the training athlete or military recruit has been hypothesized to cause increased bone strain that may contribute to the development of a stress fracture. Under normal circumstances, muscles exert a protective effect by contracting to reduce bending strains on cortical bone surfaces. In vivo strain studies in dogs show that muscle fatigue following strenuous exercise elevates bone strain and changes strain distribution. However, a similar experiment has yet to be performed in humans. The purpose of this work was to test the hypothesis in humans that strenuous fatiguing exercise causes an elevation in bone strain. It was also hypothesized that this elevation is greater in younger people than in older people due to the decline in muscle strength and endurance that normally occurs with age. To test these hypotheses, strain in the tibiae of seven human volunteers was ...
In the paper six cases of facial osteomyelitis as a complication of chronic sinusitis in hemophiliac-AIDS patients are reported. Osteomyelitis was suggested by an increasing of erythrocyte sedimentation rate. The diagnosis was confirmed by a positive {sup 99m} Tc MDP scintigraphy. The patients were submitted to clinical treatment. The erythrocyte sedimentation rate and 67-gallium citrate scans were used in the follow-up of the therapy. Three patients had negative gallium after three weeks of organism-specific antibiotic therapy; in two patients the gallium scintigraphy remained positive. One patient did not undergo the radionuclide scan for this clinical conditions. These results suggest that MDP scans showed higher sensitivity and specificity in detection of bone disease in chronic sinusitis. Gallium scans appeared to be valuable tool in the follow-up of the infection. There are no reports in the literature of osteomyelitis as a complication ...
Bone mineral content as determined by computerized tomography (CT) and mechanical strength on axial loading were compared in 36 cadaveric femur specimens. Based on the CT measurements of density and area, the mass of a transverse slice of the femur was estimated. Highly significant correlations were demonstrated between strength and cancellous bone density. Even higher correlations were revealed when the bone masses of the proximal and distal femoral areas were calculated. Based on these findings, an equal distribution of the effective mass of the femur was postulated. This hypothesis was confirmed in an experimental rotational model. The CT attenuation values were also correlated to direct measurements of bone mineral content, i.e. calcium. Moreover, the strength of different metal implants, commonly used in femoral neck fractures, were assessed in cadaver specimens. 134 refs., 13 ...
Twenty-seven patients with symptoms or clinical findings suggesting joint or bone disorders of the anterior chest wall (ACW) were evaluated by spiral CT with 3-dimensional (3-D) and multiplanar reconstructions. Preceding conventional ACW tomography was performed in 10 patients. ACW joint and bone changes were visualized more adequately by coronal 2-D reconstructions based on spiral CT than by conventional tomography. In addition, nonossified costal cartilages and soft tissue lesions were demonstrated. 3-D reconstructions sometimes added information, especially in patients with fracture and dislocation. (orig.).
Secondary ischemic necrosis of femoral head due to loss of blood supply following to femoral neck fracture is well known. The regional distribution of bone-seeking radiopharmaceuricals in the skeleton can depend on a number of factors, but bone blood flow is a major physiological determinant of regional skeletal uptake of Tc-99m polyphosphate and bone imaging may thus be used for the evaluation of vascularity of the femoral head. The authors made a comparative study of scintigraphic findings and operative findings of 28 cases of femoral neck fracture treated at Kyung Hee University Hospital from April 1980 to May 1984. The results were as follows: 1. In 16 cases of proven avascular necorsis of femoral head, scintigraphy showed absent or decreased activity in 14 cases (87.5%), while radiography showed increased density in 10 cases (62.5%). 2. In 12 cases of proven vital femoral head, ...
We examined whether or not BMD or bone markers were useful for assessing the risk of vertebral fractures in 248 Japanese men with type 2 diabetes. We analyzed the relationships between bone markers (osteocalcin [OC], bone-specific alkaline phosphatase [BAP], urinary N-terminal cross-linked telopeptide of type-I collagen) or BMD and HbA1c, urinary C-peptide, insulin-like growth factor-I (IGF-I), parathyroid hormone, 1,25(OH)2 vitamin D, and the presence of prevalent vertebral fractures. Multiple regression analysis adjusted for age, body height, weight, duration of diabetes, and serum creatinine showed that serum OC and OC/BAP ratio were correlated negatively with HbA1c (P?P?P?0.05). This association was still significant after additional adjustment for lumbar or femoral neck BMD. Our res...
A retrospective study was made of all radionuclide (RN) bone images performed at our institution over a two-year period to evaluate femoral head viability after nonpathologic fracture of the femoral neck. Twelve patients had avascular femoral heads during the perioperative period, of which nine had adequate follow-up. Seven of these nine patients had follow-up bone images. Revascularization occurred in four patients, while three had persistent absence of femoral head uptake. With clinical follow-up ranging from four to 29 months (median: 14 months), only two of these nine patients developed clinical or radiographic evidence of osteonecrosis. RN bone imaging performed in the perioperative period does not reliably predict the development of post-traumatic osteonecrosis of the femoral head and, at present, should not be used to determine prospectively method of treatment of femoral neck ...
A retrospective study was made of all radionuclide (RN) bone images performed at our institution over a two-year period to evaluate femoral head viability after nonpathologic fracture of the femoral neck. Twelve patients had avascular femoral heads during the perioperative period, of which nine had adequate follow-up. Seven of these nine patients had follow-up bone images. Revascularization occurred in four patients, while three had persistent absence of femoral head uptake. With clinical follow-up ranging from four to 29 months (median: 14 months), only two of these nine patients developed clinical or radiographic evidence of osteonecrosis. RN bone imaging performed in the perioperative period does not reliably predict the development of post-traumatic osteonecrosis of the femoral head and, at present, should not be used to determine prospectively method of treatment of femoral neck ...
Quantitative bone scintigraphy was performed on 23 white females with post-menopausal osteoporosis and vertebral compression fractures. These patients were then entered into a randomized, double-blind clinical trial or sodium fluoride therapy (NaF=14, placebo=9) which included repeat bone scintigraphy every six months. Scintigraphic images were acquired for 500K counts per image over the total body with computer acquisition over the posterior thoracic and lumbar spine. Images were obtained on a wide field-of-view gamma camera two hours after injecting 15 mCi of Tc-99m MDP. Data analysis showed a significant reduction in the activity ratio of abnormal vertebral body to normal vertebral body in those patients treated with sodium fluoride (paired t-test p=0.0095). No significant change was observed in the control group of (p=0.142). These results suggest that sodium fluoride therapy promotes more rapid healing of osteoporotic ...
The role of high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) in the diagnosis of preoperative and postoperative complications caused by acquired cholesteatomas will be described in this paper. The pre- and postoperative imaging of the temporal bone was performed with HRCT and MRI. HRCT and MRI were performed in the axial and coronal plane. MRI was done with T2 weighted and T1 weighted sequences both before and after the intravenous application of contrast material. All imaging findings were confirmed clinically or surgically. The preoperative cholesteatoma-caused complications depicted by HRCT included bony erosions of the ossicles, scutum, facial canal in the middle ear, tympanic walls including the tegmen tympani, and of the labyrinth. The preoperative cholesteatoma-caused complications depicted by MRI included signs indicative for labyrinthitis, and brain abscess. Postoperative HRCT depicted bony erosions ...
Quantitative assessment of bone scintigraphy was performed in fifty-six patients with hip joint disease including femoral neck fracture, aseptic necrosis of the femoral head, traumatic dislocation of the hip, Perthes disease, and transient synovitis of the hip. In the static study, bone scintigraphy was obtained 3 hours after injection of sup(99m)Tc-MDP by gamma camera equipped with a computer and uptake ratios were calculated. In the dynamic study, bone scintigraphy was performed in one, 3 and 5 hours after injection of radionuclide. Femoral head uptake ratio was markedly decreased in osteonecrosis following femoral neck fracture and characteristically increased in aseptic necrosis of the femoral head but prolonged retention of sup(99m)Tc-MDP could be observed. Uptake ratios of epiphysis were decreased in Perthes disease but normal in transient synovitis of the hip. Static and ...
The authors propose a method for determining the risk of femoral neck fracture in osteoporotic patients that is not based on densitometric techniques. The method is based on a structural analysis performed by a computer on data taken from a single digital anteroposterior projection of the hip. From the image, the effective cross-sectional area and cross-sectional moment of inertia are computed from attenuation principles. Together with other geometric measurements, these data are used in an engineering analysis to compute the yield strength of the proximal femur, under stress applied through the acetabulum in a one-legged stance. An index of fracture risk based on the ratio of estimated yield strength to body weight is proposed. Ultimately it is expected that this work will allow the clinician to estimate hip fracture risk in osteoporotic patient using widely available existing technology, a goal which has eluded ...
The purpose of this study is to clarify the confusing nomenclature and pathogenesis of Developmental Facial Paralysis, and how it can be differentiated from other causes of facial paralysis present at birth. Differentiating developmental from traumatic facial paralysis noted at birth is important for determining prognosis, but also for medicolegal reasons. Given the dramatic presentation of this condition, accurate and reliable guidelines are necessary in order to facilitate early diagnosis and initiate appropriate therapy, while providing support and counselling to the family. The 30 years experience of our center in the management of developmental facial paralysis is dependent upon a thorough understanding of facial nerve embryology, anatomy, nerve physiology, and an appreciation of well...
Purpose: To evaluate MR imaging of the hip in patients with a clinically suspected impacted fracture of the femoral neck in cases where conventional plain films show negative or equivocal findings. Material and Methods: Twenty-seven such patients were prospectively examined by MR imaging with a 1.0 T unit, within 24 hours of admittance to hospital. A coronal T1-weighted turbo spin-echo sequence (n=27), and a coronal STIR sequence (n=25) or a coronal T2-weighted turbo spin-echo fast saturation sequence (n=2) were used. The evaluations were made by 2 radiologists with experience in musculoskeletal radiology. Results: There were 6 patients with a petrochanteric fracture, 2 without and 4 with slight displacement. Five patients had an impacted fracture of the femoral neck, and 3 had a fracture of the superior pubic bone. Of 2 patients with advanced arthrosis, i had an impacted femoral ...
Purpose: In an experimental study, the correlation between the trabecular bone density of the different regions of the proximal femur and the fracture load in the setting of femoral neck fractures was examined. Methods: The bone mineral density 41 random proximal human femora was estimated by single-energy quanitative CT (SE-QCT). The trabecular bone density was measured at the greatest possible extracortical volume at midcapital, midneck and intertrochanteric level and in the 1 cm{sup 3} volumes of the centres of these regions in a standardised 10 mm thick slice in the middle of the femoral neck axis (in mg/ml Ca-hydroxyl apatite). The proximal femora were then isolated and mounted on a compression/bending device under two-legged stand conditions and loaded up to the point when a femoral neck fracture occurred. Results: Statistical analysis revealed a linear ...
In the case of injuries of the ankle joint, an imaging technique is expected to reveal the state of the bones, ligaments, and articular cartilage. Irrespective of novel imaging techniques, a plain radiography will be made in order to obtain a first picture of the injury. Examples are given, showing that further orientation along the Lauge-Hansen classification scheme of this type of injury helps to completely ascertain the damage to the Articulatio talocruralis. Further examinations applying specific methods such as arthrography will detect possible, isolated syndesmosis ruptures; lesions of the ligaments can also be directly detected by CT or MRT. The articular cartilage and its lesions can be visualized by a combination of CT and arthrography, but are better shown by the completely non-invasive MRT. This latter method also gives insight into pathological processes with the bone. It allows to detect necrotic bone regions ...
Dual energy X-ray absorptiometry (Hologic QDR-1000) was used to quantitatively analyze the diagnosis and prevention of osteoporosis. The peak bone mineral density (BMD) of the spine appeared in normal men in their twenties and in normal women in their thirties. There was acceleration of bone loss in the 50 to 60 year age bracket (premenopause and postmenopause) in normal women. On the contrary, the peak BMD of the femoral neck in normal men and women appeared in their twenties after which it decreased slightly with age. Comparison showed that the femoral neck BMD of normal women was lower than that of men throughout all ages. The fracture threshold, 0.756 g/cm[sup 2] for the spine, was obtained by scanning 73 females with spinal fractures, the mean BMDs for L2-L4 at the 90th percentile level were used as the fracture threshold. The fracture threshold of femoral ...
The ultimate compressive strength of 36 thoracolumbar vertebrae was determined experimentally. In addition, the trabecular bone mineral content was measured by single energy quantitative computed tomography. The areas of fractured endplates were also determined by computed tomography. The results show that a linear relationship exists between the compressive strength and the product of bone density and endplate area. These data allow an in vivo prediction of vertebral body strength using a noninvasive method with a standard error of estimate amounting to less than 0.95 kN. PMID:3212488
Abstract The healing of predominantly metaphyseal fractures in postmenopausal osteoporosis is delayed and comparatively poor. Due to the potential side effects of HRT, natural alternatives are appealing. The aim of this study was to determine whether Cimicifuga racemosa extract BNO 1055 improves metaphyseal fracture healing in severe osteopenic bone in rats. Thirty three 12 week old female rats developed severe osteopenia during 10 weeks after ovariectomy. After metaphyseal tibial osteotomy and standardized T plate osteosynthesis, the healing periods in ovariectomized rats (C), 17 estradiol (E) and Cimicifuga racemosa (CR) supplemented diets were assessed for 35 days. Changes in callus morphology were evaluated qualitatively by biomechanical testing and quantitatively in microradiographies...
Magnetic resonance imaging can be used in the trauma setting to detect fractures and associated soft tissue injuries of the musculoskeletal system. Magnetic resonance imaging complements plain radiography and CT for evaluating cancellous bone, cartilage and growth-plate injuries, and intra- and extraarticular supporting soft tissue structures. This review outlines typical applications and imaging consideration for injuries of the pelvis and lower extremity. (orig.) With 12 figs., 78 refs.
In this study the distribution of sup(99m)Tc-diphosphonate and tetracycline and histological examination were also investigated in femoral heads obtained during replacement surgery. One hundred patients received scintigraphic examinations immediately after the occurrence of injury and every month thereafter. Ten mCi of sup(99m)Tc-diphosphonate was injected intravenously. Three hours later, detailed scintigrams of the bilateral hip areas were made with a scintillation camera connected to a computer. The uptake of sup(99m)Tc-diphosphonate in the fracture was expressed as a ratio of the counts recorded in one area to those recorded in the other area. A peak value in count ratio was recorded in all patients 4 to 6 weeks after fractures. One hundred patients were classified into a normal healing group and a delayed or non-union group. Namely, sup(99m)Tc-diphosphonate uptake was significantly higher in the delayed or non-union group than in the ...
In this study the distribution of sup(99m)Tc-diphosphonate and tetracycline and histological examination were also investigated in femoral heads obtained during replacement surgery. One hundred patients received scintigraphic examinations immediately after the occurrence of injury and every month thereafter. Ten mCi of sup(99m)Tc-diphosphonate was injected intravenously. Three hours later, detailed scintigrams of the bilateral hips areas were made with a scintillation camera connected to a computer. The uptake of sup(99m)Tc-diphosphonate in the fracture was expressed as a ratio of the counts recorded in one area to those recorded in the other area. A peak value in count ratio was recorded in all patients 4 to 6 weeks after fractures. One hundred patients were classified into a normal healing group and a delayed or non-union group. Namely, sup(99m)Tc-diphosphonate uptake was significantly higher in the delayed or non-union group than in the ...
A selected series of 24 patients with displaced medial femoral neck fracture, treated with closed reduction and osteosynthesis with cancellous bone screws (ASIF), were investigated. During an observation period of 6 to 26 months, serial hip joint scintigraphies were performed and compared with serial X-ray examinations. At the first scintigraphic examination performed on average 5-6 weeks after the fracture, two separate investigators found a decreased amount of activity or no activity in the femoral head of 10 and 8 patients, respectively. At the second scintigraphic examination performed on average 11.1 weeks after the fracture both investigators found no activity or a decreased amount of activity in 8 patients. This figure declined to 7 during the following period, because one patient with decreased activity was recorded as having normal activity 15 months after the fracture. ...
PurposeTo report unusual ocular manifestations of branchio-oculo-facial syndrome (BOFS) caused by a novel mutation in activating enhancer binding protein 2 alpha (TFAP2A).MethodsFull...Full Text Available
An influential neural model of face perception suggests that the posterior superior temporal sulcus (STS) is sensitive to those aspects of faces that produce transient visual changes, including facial...Full Text Available
The role of high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) in the diagnosis of preoperative and postoperative complications caused by acquired cholesteatomas will be described in this paper. The pre- and postoperative imaging of the temporal bone was performed with HRCT and MRI. HRCT and MRI were performed in the axial and coronal plane. MRI was done with T2 weighted and T1 weighted sequences both before and after the intravenous application of contrast material. All imaging findings were confirmed clinically or surgically. The preoperative cholesteatoma-caused complications depicted by HRCT included bony erosions of the ossicles, scutum, facial canal in the middle ear, tympanic walls including the tegmen tympani, and of the labyrinth. The preoperative cholesteatoma-caused complications depicted by MRI included signs indicative for labyrinthitis, and brain abscess. Postoperative HRCT depicted bony erosions ...
Purpose of this work is to investigate the role of Helical CT and the usefulness of three-dimensional (3D) imaging for pre-operative planning and follow-up of reconstructive maxillofacial surgery with alloplastic material in neoplastic disease involving this region. From 1996 to 1999 eleven patients were examined with Helical CT and 3D images for planning of maxillofacial plastic and reconstructive surgery for advanced cancer of this anatomically complex region. A 3D-modulated titanium mesh (100%) or micro nets was used to rebuild the anterior surface of maxillary bone and the orbital floor. The mesh was cut to the appropriate size and shape and curved where necessary. Within the residual sinusal cavity a siliconed filling was used surmounting an acrylic prosthesis with dental arch to rebuild the palate. A rehydrated bovine pericardium was affixed and moduled on the borders in two cases only. Three-dimensionally reconstructed CT images were obtained preoperatively ...
Investigations of radionuclide metabolism and effects in various mammalian species revealed important similarities between animals and humans and between some animal species. These include skeletal deposition of radium and radiostrontium in bone volume; deposition on bone surfaces of plutonium and other actinides; liver deposition of actinides; induction of skeletal or liver malignancies by these radionuclides; induction of tooth and jaw abnormalities; mammary cancer induction by radium in humans and in the beagle; depression of circulating cells in blood; and induction of bonefractures. There are also inter-species differences that may not have been noted if multiple species (including humans) had not been studied. Some of these are more rapid excretion of radium in humans compared with most other mammals; induction by radium of eye melanomas in animals but not humans; rapid loss of deposited ...
The bone scans of 33 patients (pts) with recent subcapital fractures (fx) of the femur were evaluated prospectively to determine their value in predicting femoral head visability. Each of the 33 pts (ll men, 22 women, age range 30-92) had a pre-operative bone scan within 72 hrs of the fx (23 pts within 24 hrs). Anterior and posterior planar views of both hips and pinhole views (50% of pts) were obtained 2 hrs after administration of Tc-99m HDP. The femoral head was classified as perfused if it showed the same activity as the opposite normal side or if it showed only slightly decreased activity. Femoral heads showing absent activity were classified as nonperfused. Overall, 20 of the 33 pts showed a photopenic femoral head on the side of the fx. Only 2 pts showed increased activity at hte site of the fx. Internal fixation of the fx was performed in 23 pts, 12 of whom had one or more follow-up scans. Five of these 12 pts ...
BACKGROUNDHirsutism is the presence of excess body or facial terminal (coarse) hair growth in females in a male-like pattern, affects 5–15% of women, and is an important...Full Text Available
BackgroundBlindness due to trachoma is avoidable through Surgery, Antibiotics, Facial hygiene and Environmental improvements (SAFE). Recent surveys have shown trachoma to be a serious...Full Text Available
135 patients with histologically proven Ewing's sarcoma, treated at the Institute Gustave Roussy between 1960-1974 were reviewed in order to establish the effectiveness and the complications associated with radiotherapy. In 133 patients, a dose of at least 60 Gy for long bones, 55 Gy for flat bones and 45 Gy for vertebrae was given. 26 major complications (of which more than one occured in certain patients) were observed: 12 cases of growth retardation, loss of joint function in 7 cases, 3 fractures, 2 osteonecroses, 2 cases of delayed healing, one massive soft tissue fibrosis, 1 abdominocutaneous fistula, 2 cases of symptomatic pulmonary fibrosis with associated infection, 2 cases of radiation enteropathy, 2 of mammary hypoplasia and 1 osteosarcoma developing in an irradiated zone. These complications necessitated 12 surgical interventions, including 4 disarticulations or amputations. The incidence of complications can be ...
Introduction: There are many problems in the radiological diagnosis of aseptic loosening in total hip arthroplasty. Computed tomography (CT) and magnetic resonance tomography (MRT) are not usable for metallic implants (stainless steel, cobalt alloy, titanium alloy). Material and Methods: From April 1993 to December 1993 15 CFRP non-cemented hip prostheses have been implanted. In a prospective clinical study plane radiographs, CT and MRT have been analysed. Results: Three stems were revised (1 femoral fracture, 1 severe thigh pain, 1 aseptic loosening). CFRP are not visible in plane radiographs. There was a complete (two-third of the cases) or nearly complete (one-third of the cases) small sclerotic interface between the prosthesis and the bone, these were apparent in CT and MRT in stable implant cases and did not have any clinical correlations. Discussion: The small sclerotic interface is quite different in comparison to so called 'Reactive ...
This study is a contribution to the growing body of work on the influence of changes in the composition of an acrylic bone cement on various properties of the curing and cured material. The focus is on one commercially-available acrylic bone cement brand, Surgical Simplex P, and three variants of it and a series of properties, namely, setting time, maximum exotherm temperature, activation energy and frequency factor for the polymerization reaction, diffusion coefficient for the uptake of phosphate buffered saline, at 37 degrees C, ultimate compressive strength (UCS), plane-strain fracture toughness, fatigue life (under fully-reversed tension-compression stress), hardness (H) and elastic modulus (both determined using quasi-static nanoindentation), and the variation of the storage and loss moduli with frequency of the applied force in a dynamic nanoindentation test. It was found that (a) a 68% reduction in the volume of the ...
Objective: To discuss the clinical application value of dual energy subtraction (DES) in direct digital radiography of chest. Methods: 83 cases of chest digital radiography(DR) using double-energy subtraction (DES) were randomly selected, and three posterior-anterior (PA) chest films (standard image, bone image and soft tissue image) were obtained in each case, which is so called 'bone and soft tissue separated' technology. Results: With the aid of double energy subtraction (DES), the bony chest was subtracted, the sensitivity and specificity of pulmonary calcification were improved, and sensitivity of pulmonary nodes was also improved, enhancing the distinction between pulmonary benign or malignant lesions, enlightening the diagnosis of chest cage lesions, and showing a clear superiority in the detection of pulmonary nodes comparing to common chest films. The double energy subtraction (DES) films showed a higher diagnostic accuracy in the ...
Physiological bone remodeling is a highly coordinated process responsible for bone resorption and formation and is necessary to repair damaged bone and to maintain mineral homeostasis. In addition to...Full Text Available
BackgroundMultiple myeloma is a hematologic malignancy associated with the development of a destructive osteolytic bone disease.ResultsMathematical...Full Text Available
The ability to mechanically reinforce an osteoporotic vertebral body could impede spinal compression fracture and the associated pain and complications. Previous studies have shown that reinforcement of fractured vertebrae with conventional acrylic cement can relieve symptoms and avoid further collapse. In this study, we explored the use of a carbonated apatite cement combined with a minimally invasive injection technique to improve the compressive mechanical properties of cadaveric vertebral bodies. After establishing the biomechanical characteristics of cement formulations intended to have appropriate viscosities, we evaluated the infiltration of the cements into thoracic vertebral bodies using a combined suction-injection technique. The energy-absorption capabilities of the reinforced vertebral bodies were then measured during axial compressive tests and compared with those of nonreinforced vertebrae. The ultimate compressive strength of the ...
If bone strength was the only requirement of skeleton, it could be achieved with bulk, but bone must also be light. During growth, bone modelling and remodelling optimize strength, by depositing bone...Full Text Available
Around the world there is a small industry of non-governmental organisations that provide health care in niche areas that cannot be met by national health care provision. One topic is facial deformity that can have a dramatic effect on quality of life. In this study we investigate the morbidity and outcome of a British surgical team working for a 2-week period in Ethiopia. Thirty-five patients who presented with facial deformities had 47 operations during a 2-week period. Data were recorded for a minimum of 3 weeks postoperatively. Operative techniques were classified as simple or complex. Postoperative complications were assessed and classified as major, intermediate, and minor. In addition, the character of each complication was recorded and the cause elucidated. After 3 weeks the clinic...
(1).—Varieties of spinal injuries, the three groups of common usage: fractures, dislocations, fracture-dislocations. Shall not refer in detail to fractures of the spinous or transverse processes....Full Text Available
BackgroundThe facial region has been the most common site of injury following violent episodes. The purpose of this study was to determine the prevalence and pattern of maxillofacial...Full Text Available
This study was an evaluation of the performance of self-applied, blue light, light-emitting diode therapy in the treatment of mild-to-moderate inflammatory acne on the face, concerning: 1) time to improvement...Full Text Available
Autism is a pervasive developmental condition, characterized by impairments in non-verbal communication, social relationships and stereotypical patterns of behavior. A large body of evidence suggests that several aspects of face processing are impaired in autism, including anomalies in gaze processing, memory for facial identity and recognition of facial expressions of emotion. In search of neural markers of anomalous face processing in autism, much interest has focused on a network of brain regions that are implicated in social cognition and face processing. In this review, we will focus on three such regions, namely the STS for its role in processing gaze and facial movements, the FFA in face detection and identification and the amygdala in processing facial expressions of emotion. Much evidence suggests that a better understanding of the normal development of these specialized regions is essential ...
A 13 year- old girl presented to the department with sternomental contractures as a result of facial burns from kerosene explosion. Difficult airway was envisaged. Over the period of time she developed...Full Text Available
Forty children with the fetal alcohol syndrome were identified in the west of Scotland. All were growth retarded and had abnormal facial features, and all those who were tested were found to have neurological...Full Text Available
Sixteen patients with PAGET's disease of bone underwent quantitative bone scintigraphy with "9"9"mTc-MDP before and after a long-term treatment with carbocalcitonin, a synthetic analogue of eel calcitonin. The radionuclide study consisted in the blood pool and bone uptake measurement and in the bone avidity calculation (bone uptake - blood pool ratio). In our patients, a significant decrease in bone uptake and bone avidity was found, whereas the blood pool remained statistically unchanged. This behaviour could be accounted for the shift of the compact bone to a lamellar pattern. (orig.).
Sixteen patients with PAGET's disease of bone underwent quantitative bone scintigraphy with /sup 99m/Tc-MDP before and after a long-term treatment with carbocalcitonin, a synthetic analogue of eel calcitonin. The radionuclide study consisted in the blood pool and bone uptake measurement and in the bone avidity calculation (bone uptake - blood pool ratio). In our patients, a significant decrease in bone uptake and bone avidity was found, whereas the blood pool remained statistically unchanged. This behaviour could be accounted for the shift of the compact bone to a lamellar pattern.
Low resolution and un-sharp facial images are always captured from surveillance videos because of long human-camera distance and human movements. Previous works addressed this problem by using an active camera to capture close-up facial images without considering human movements and mechanical delays of the active camera. In this paper, we proposed a unified framework to capture facial images in video surveillance systems by using one static and active camera in a cooperative manner. Human faces are first located by a skin-color based real-time face detection algorithm. A stereo camera model is also employed to approximate human face location and his/her velocity with respect to the active camera. Given the mechanical delays of the active camera, the position of a target face with a given delay can be estimated using a Human-Camera Synchronization Model. By controlling the active camera with corresponding amount of pan, ...
The paper deals with sixteen cases of acetabular fractures studied with CT. After a short description of the normal CT findings, the different kind of fractures are reported. The usefulness of CT examination in evaluating acetabular fractures and their complications is confirmed both in conservative treatment and surgical approach.
Marginal fractures of the tibial plateau are associated with a high incidence of soft tissue injuries to the stabilising structures of the knee joint. Injuries to the anterior cruciate ligament are associated with the Segond fracture and impingement fractures of the posteromedial tibial plateau. Recognition of these fractures aids diagnosis of these injuries. Marginal fractures of the tibial plateau associated with posterior cruciate ligament injuries are less common, though recently a ''reverse'' Segond fracture has been recognised. We describe a fracture of the anteromedial tibial plateau associated with complete disruption of the posterior cruciate ligament and posterolateral complex. (orig.)
Objective. To examine the incidence, radiographic and histologic findings of medial femoral neck buttressing in a consecutive group of patients undergoing total hip arthroplasty.Design. Biomechanical parameters were evaluated on standard anteroposterior pelvic radiographs of 113 patients prior to hip replacement surgery. Demographic information on all patients was reviewed and histologic evaluation was performed on specimens obtained at the time of surgery.Results. The incidence of medial femoral neck buttressing was found to be 50% in a consecutive series of patients undergoing total hip arthroplasty. The incidence was slightly higher in women (56% vs 41%). Patients with buttressing had increased neck-shaft angles and smaller femoral neck diameters than were seen in patients without buttressing. Histologic evaluation demonstrated that the buttress resulted from deposition bone by the periosteum on the femoral neck in the absence of any evidence of femoral neck ...
The staging of patients with multiple myeloma demands sensitive imaging methods for the assessment of the skeletal system. MRI allows for direct visualization of the bone marrow which exhibits five different infiltration patterns in multiple myeloma: 1. normal appearance of the bone marrow, 2. focal involvement, 3. homogeneous diffuse infiltration, 4. combined diffuse and focal infiltration, 5. ''salt and pepper'' pattern with inhomogeneous bone marrow signals due to multiple fat islands. The combination of T1w-SE and STIR sequences is best suited for detecting all infiltration patterns and for the differential diagnoses e. g. hemangiomas. With parallel imaging in MRI, acquisition times can be markedly reduced and whole-body screening of the bone marrow can be achieved within 30 min. MRI is superior to radiography for the detection of focal as well as diffuse ...
In this retrospective study, 28 cases of Ewing's sarcoma are reviewed for the onset of metastasis. Bone scans demonstrated bone metastasis in three out of 28 patients at presentation. Of the 22 patients free of metastases at presentation, ten subsequently developed bone metastases. In six of these patients, the bone scan was the earliest demonstrator of metastatic disease. Bone scans are recommended at presentation and periodically during follow-up.
The objective of this study was to simplify the opacifying mixing process of the bone cement and contrast used for percutaneous vertebroplasty (PVP). We performed a biomechanical study of polymethyl methacrylate (PMMA) (Corinplast 3) using three different mixtures of PMMA, monomer, and contrast: group I, 2:1; group II, 3:2; group III, 3:2:1 ratio of powder/monomer/iodinated contrast (Omnipaque). In vitro biomechanical testing of ultimate compressive strength was carried out in all samples. Following the conclusion of a proper bone cement mixture regimen drawn from the in vitro study, PVP was performed in 125 patients: 58 with cancer, 12 with hemangioma, and 54 with osteoporotic fracture. The ultimate compressive strength in group III was decreased by 38% compared to groups II and I. Proper fluoroscopic visualization was achieved in all PVP procedures using this mixture. There were no major complications associated with ...
The objective of this study was to simplify the opacifying mixing process of the bone cement and contrast used for percutaneous vertebroplasty (PVP). We performed a biomechanical study of polymethyl methacrylate (PMMA) (Corinplast{sup TM} 3) using three different mixtures of PMMA, monomer, and contrast: group I, 2:1; group II, 3:2; group III, 3:2:1 ratio of powder/monomer/iodinated contrast (Omnipaque). In vitro biomechanical testing of ultimate compressive strength was carried out in all samples. Following the conclusion of a proper bone cement mixture regimen drawn from the in vitro study, PVP was performed in 125 patients: 58 with cancer, 12 with hemangioma, and 54 with osteoporotic fracture. The ultimate compressive strength in group III was decreased by 38% compared to groups II and I. Proper fluoroscopic visualization was achieved in all PVP procedures using this mixture. There were no major complications associated ...
This work contains 27 chapters which cover recent advances in fracture mechanics applied to cement-based composites: concrete, reinforced concrete, and fiber reinforced concrete. The book, based on a NATO Advanced Study Institute, is a comprehensive survey of treating nonlinearity associated with crack growth in brittle materials such as cement composites, rocks and ice. The book is divided into 8 major themes: advances in nonlinear fracture mechanics; fracture processes; numerical modelling of fracture; experimental methods of determining fracture parameters; damage and continuum modelling; strain-rate and dynamic effects of crack propagation; stress-corrosion, time and temperature effects on fracture; and implications for concrete structures.
The objectives of this project are to detect and characterize fractures in a naturally fractured tight gas reservoir, using surface seismic methods, borehole imaging logs, and in-situ stress field data. Further, the project aims to evaluate the various seismic methods as to their effectiveness in characterizing the fractures, and to formulate the optimum employment of the seismic methods as regards fracture characterization.
Questions are examined of prospecting for nonanticlinical traps within North Sakhalin, their spatial distribution and evaluation of the outlook for oil and gas content. Traps of tapering and facial substitution on wings and periclines of local elevations, accumulative bar and erosion-accumulative channel are isolated. THe hypothesis is made that it is possible to form stratigraphic traps above the discrepancy and below it. It is noted that formation of zones of lithological tapering and facial substitution are associated with areas of the exchange of the sedimentation situation. The primary role of the shore and coastal zones in the formation of the examined types of nonanticlinal traps is established. The Okhino-Ekhabinskiy region in North Sakhalin is isolated as the primary object for prospecting for nonanticlinal traps.
Abstract. Scanning electron microscopy documentation of first instar Calliphora vicina Robineau-Desvoidy, Phormia regina (Meigen) and Lucilia illustris (Meigen) (Diptera: Calliphoridae) is presented for the first time, and the following morphological structures are documented: pseudocephalon; antenna; maxillary palpus; facial mask; labial lobe; thoracic and abdominal spinulation; spiracular field; posterior spiracles, and anal pad. Light microscopy documentation and illustrations are provided for the cephaloskeleton in lateral and ventral views. New diagnostic features are revealed in the configuration of the facial mask, cephaloskeleton and posterior spiracles. The first instar morphology of C. vicina, Ph. regina and L. illustris is discussed in the light of existing knowledge about early...
This paper introduces a parallel measurement approach for fast infrared-based human temperature screening suitable for use in a large public area. Our key idea is based on the combination of simple image processing algorithms, infrared technology, and human flow management. With this multidisciplinary concept, we arrange as many people as possible in a two-dimensional space in front of a thermal imaging camera and then highlight all human facial areas through simple image filtering, image morphological, and particle analysis processes. In this way, an individual's face in live thermal image can be located and the maximum facial skin temperature can be monitored and displayed. Our experiment shows a measured 1ms processing time in highlighting all human face areas. With a thermal imaging ca...
Abstract A 3-month, open-label, single-center study was conducted to determine whether a uniquely formulated and physiologically balanced topical treatment serum containing multiple growth factors, cytokines, peptides, antioxidants and depigmenting agents could improve the visible signs of facial photodamage. Thirty-seven females, aged 32-55 years, with mild to severe, fine and coarse peri-ocular wrinkles were enrolled and completed the study. Subjects applied the treatment serum to the face twice daily for 3 months in conjunction with a basic skincare regimen. Clinical evaluations of photodamage were performed at baseline and months 1, 2 and 3. Cutometer measurements and subject self-assessment questionnaires were also conducted during the study. Clinical evaluations showed statistically ...
Background:High-energy fractures of posterior tibial plateau always need surgical treatment. Generally, posterior fragments of these fractures could not be exposed and reduced...Full Text Available
BackgroundNorway, and particularly Oslo, has the highest reported incidence of hip fractures in the world. It is increasingly common to care for older hip fracture patients in orthogeriatric...Full Text Available
IntroductionSeizures with or without trauma may cause fractures that occur commonly in epileptic seizures. Fracture risk is less reported in non-epileptic seizures. Some metabolic...Full Text Available
BackgroundHip fracture patients often have an impaired nutritional status at the time of fracture, which can result in a higher complication rate, prolonged rehabilitation time and...Full Text Available
This book contains over 20 selections. Some of the titles are: Continuum damage mechanics studies on the dynamic fracture of concrete; Dynamic compressive strength of cementitious materials; Rate-sensitivity of mode I and mode II fracture concrete; and An impact damage model of concrete.
Bone radiotracer uptake in renal osteodystrophy was investigated in 35 dialysis patients by correlating the results of quantitative bone scintigraphy with those of biochemical and bone morphometric studies. There were highly significant correlations (P < 0.001) between the total skeletal activity and the biochemical (iPTH and alkaline phosphatase), and histologic parameters of hyperparathyroidism. These clinical results strongly suggest that increased bone turnover i.e. hyperparathyroidism, rather than osteomalacia is the major cause of increased skeletal uptake in renal osteodystrophy.
We report a case of stress fracture of the clavicle associated with sternocostoclavicular hyperostosis. A 60-year-old man sustained a stress fracture of the right clavicle with no history of trauma. On radiography, hyperostosis of the anterior chest wall and ankylosis of the sternoclavicular joint were evident in addition to the fracture. Fracture healing was uneventful after 2.5 months. Ankylosis of the sternoclavicular joint may have caused increased stress at the midshaft of the clavicle by daily activity or minor trauma. Such a fracture is a rare complication of sternocostoclavicular hyperostosis. (orig.)
The main objectives of this project are to quantify the changes in fracture porosity and multi-phase transport properties as a function of confining stress. These changes will be integrated into conceptual and numerical models that will improve our ability to predict and optimize fluid transport in fractured system. This report details our progress on: (a) developing the direct experimental measurements of fracture aperture and topology and fluid occupancy using high-resolution x-ray micro-tomography, (b) counter-current fluid transport between the matrix and the fracture, (c) studying the effect of confining stress on the distribution of fracture aperture and two-phase flow, and (d) characterization of shear fractures and their impact on multi-phase flow. The three-dimensional surface that describes the large-scale structure of the fracture ...
Background:Cemented hip arthroplasty is an established treatment for femoral neck fracture in the mobile elderly. Cement pressurization raises intramedullary pressure and...Full Text Available
MINC stands for Multiple INteracting continua.'' It is an approximate method for modeling fluid and heat flow in fractured- porous media, developed by Pruess and Narasimhan (1982, 1985) at the Lawrence Berkeley Laboratory. The method is applicable to flow processes in which an important aspect is the exchange of fluid, heat, or chemical species between fractures and unfractured rock. Examples include production and injection operations in fractured geothermal reservoirs, water-flooding, steamflooding, and other methods for enhanced oil recovery from fractured reservoirs, as well as chemical transport and contaminant migration in fractured rock. MINC can only be applied to media in which the fractures are sufficiently well connected so that a continuum treatment of flow in the fracture network can be made.
An analytical model is proposed for the design and simulation of in-situ fracture of deep oil sand formations. This model is based on the finite element variational principle in conjunction with special empirical modules to characterize in-situ oil sands behavior. A computer code by the name of SANFRAC was developed to handle the dynamic fracture of formations induced by explosives. Simulation of hydraulic fracture processes can be treated by the same code as special cases using the quasi-static analysis. Numerical case studies by the SANFRAC code indicate that extensive horizontal fracture can be achieved by dynamic loads with proper fracture starters configured at the injection well. The unique advantage of the dynamic fracturing technique over the hydraulic fracture methods is also demonstrated by these studies.
Purpose: This paper reviews and reassesses the internationally accepted niches or ‘targets’ in bone marrow that are sensitive to the induction of leukaemia and primary...Full Text Available
OBJECTIVETo assess the new quantitative bone scan parameters as markers of Charcot neuroosteoarthropathy (CNO) activity.RESEARCH DESIGN AND METHODSForty-two...Full Text Available
BackgroundCalcitonin gene related peptide (CGRP) is a neuropeptide that is abundant in the sensory neurons which innervate bone. The effects of CGRP on isolated bone cells have been...Full Text Available
BackgroundMaintenance of healthy bone requires the balanced activities of osteoclasts (OCs), which resorb bone, and osteoblasts, which build bone. Disproportionate action of OCs...Full Text Available
Bone remodeling is necessary to avoid microdamage accumulation, which could lead to whole-bone failure. Previous studies have shown that this bone-repair mechanism is triggered by osteocyte apoptosis....Full Text Available
Bone matrix gelatin, prepared by sequential chemical treatment including decalcification with 0.6 N hydrochloric acid [9], was used as an alloimplant for the treatment of benign bone tumours, tumorous conditions of bone, acetabular dysplasia, delayed union, traumatic bone defects and other disorders. The bone matrix gelatin implanted into bone defects was incorporated successfully in 98% of implantations, excluding cases of infection, tumour recurrence and recurrence of tumorous conditions. The material was also implanted into ten bone sites as an onlay but in five it was resorbed without new bone formation. The incorporation of the bone matrix gelatin into the recipient bed was completed from 6 to 33 months (average 14.9 months) after implantation. Wound infection complicated 5 of 165 implantations ...
Bone metastases of an Ewing's sarcoma were detected by magnetic resonance imaging (MRI), when bone scan, CT and plain films were still normal. This is due to the ability of MRI to detect intramedullary metastases before involvement of the cortex. (Auth.).
Using a ligature-induced model in type-2 Zucker diabetic fatty (ZDF) rat and normoglycemic littermates, we investigated whether diabetes primarily affects periodontitis by enhancing bone loss...Full Text Available
This cross-sectional study evaluated the association between radiographic evidence of alveolar bone loss and the concentration of host-derived bone resorptive factors (interleukin-1 beta, tumor...Full Text Available
BackgroundLifestyle, genetics and environmental factors are established determinants of bone density. We aimed to describe the bone characteristics of competitive top-ranked Nigerian...Full Text Available
Radionuclide bone metastases therapy is a major achievement of nuclear medicine. Development of less radiotoxic and more effective radiopharmaceuticals is therefore a challenge for radiopharmacists and industry. This paper reviews the application of rhenium-188 HEDP as a reactor- or generator-produced nuclide for bone metastases therapy. (author)
Cortical bone contributes the majority of overall bone mass and bears the bulk of axial loads in the peripheral skeleton. Bone metabolic disorders often are manifested by cortical microstructural changes...Full Text Available
Purpose: Radiotherapy (RT) has been the predominant local treatment for Ewing's sarcoma of bone at the University of Florida. Twice-daily hyperfractionated RT was initiated in 1982 to improve local control and functional outcome. This retrospective review compares the results of once-daily vs. twice-daily RT in patients with primary Ewing's sarcoma of an extremity, with emphasis on functional outcome. Methods and Materials: Between June 1971 and January 1990, 37 patients were treated at the University of Florida for nonmetastatic Ewing's sarcoma of bone with a primary lesion in an extremity. Three patients underwent amputation. Of 34 patients treated with RT, 31 had RT alone and 3 had a combination of RT and local excision. Before 1982, 14 patients received once-daily RT; since 1982, 17 patients have received twice-daily RT. Doses of once-daily RT varied from 47 to 61 Gy at 1.8-2 Gy per fraction. Doses of twice-daily RT varied, depending on the ...
The presence of natural fractures in reservoir rock can significantly enhance gas production, especially in tight gas formations. Any general knowledge of the existence, location, orientation, spatial density, and connectivity of natural fractures, as well as general reservoir structure, that can be obtained prior to active seismic acquisition and drilling can be exploited to identify key areas for subsequent higher resolution active seismic imaging. Current practices for estimating fracture properties before the acquisition of surface seismic data are usually based on the assumed geology and tectonics of the region, and empirical or fracture mechanics-based relationships between stratigraphic curvature and fracturing. The objective of this research is to investigate the potential of multicomponent surface sensor arrays, and passive seismic sources in the form of local earthquakes ...
Rock fracture characterization documents a total of 1496 fractures in unit 2 of the Tshirege Member of the Bandelier Tuff along 6013 feet of Los Alamos Canyon`s north wall adjacent to Operational Unit 1098. Geologically termed joints, these fractures likely owe their primary origin to brittle failure during the cooling contraction of the tuff after its emplacement nearly 1 million years ago. Subsequent tectonic movement along the Pajarito Fault system has modified fracture strikes, dips, apertures, and linear density. From a background linear density of approximately 20 fractures per 100-foot interval along the canyon wall, fracture density increases to values in excess of 50 fractures per 100-foot interval in a zone at and immediately east of the Omega West reactor building TA-2-1. This increase in fracture density is ...
The surgical management of osteoradionecrosis of the temporal bone has met with limited success because of the difficulty in accurate assessment of the viability of nonnecrotic bone intraoperatively. Failure to resect all nonviable bone results in recurrence of a necrotic focus. With the use of hyperbaric oxygen therapy to stabilize marginal bone and oral tetracycline to label viable bone preoperatively, removal of all nonviable bone can be accomplished. Postoperatively, a second course of hyperbaric therapy enhances wound healing, thus assuring a successful outcome. This article details a successful systematic approach that was developed to resect a necrotic focus in the temporal bone of a 10-year-old boy who had undergone a full course of radiotherapy for treatment of a rhabdomyosarcoma.
The radiographic features of Ewing's sarcoma of the bones of the hands and feet are reviewed utilizing cases obtained from the Mayo Clinic patient files and the consultation files of Drs. D.C. Dahlin and K.K. Unni. This series consists of a total of 43 cases of pathologically proven Ewing's sarcoma involving the small bones of the hands and feet. The classic radiographic features of Ewing's sarcoma in the long bones, including lytic, permeative destruction, aggressive periosteal reaction, cortical violation, and a soft tissue mass, are also seen in the bones of the hands and feet, with similar frequency. These classic features are most commonly present in lesions affecting the short tubular bones. Lesions affecting the tarsal bones more often demonstrate atypical radiographic features. These atypical radiographic appearances may play a role in the reported delay ...
This study investigated dose to bone tissue in electron beam therapy. Measurements were made using films and thermoluminescent dosimeters in a polystyrene phantom containing bone inhomogeneity for 15-MeV, 12-MeV, and 9-MeV electron beams. An increase in dose of approximately 18%, 12%, and 11%, for the three electron energies respectively, relative to the dose in polystyrene, was found for bone material having an electron density (relative to water) of 1.73. Measurements were also made using films for 15- and 9-Mev electrons in a phantom with a mandibular bone and teeth. A dose enhancement in bone of approximately 10% and 7%, respectively, for the two energies was found in the phantom where the electron density of bone was about 1.60. These results suggest that injury to bone is possible in those clinical situations where high doses of ...
This study investigated dose to bone tissue in electron beam therapy. Measurements were made using films and thermoluminescent dosimeters in a polystyrene phantom containing bone inhomogeneity for 15-MeV, 12-MeV, and 9-MeV electron beams. An increase in dose of approximately 18%, 12%, and 11%, for the three electron energies respectively, relative to the dose in polystyrene, was found for bone material having an electron density (relative to water) of 1.73. Measurements were also made using films for 15- and 9-Mev electrons in a phantom with a mandibular bone and teeth. A dose enhancement in bone of approximately 10% and 7%, respectively, for the two energies was found in the phantom where the electron density of bone was about 1.60. These results suggest that injury to bone is possible in those clinical situations where high doses of ...
In eight patients with Ewing's sarcoma bone scans were performed using "9"9"mTc-MDP. This procedure rendered possible the diagnosis of clinically or radiologically silent metastases. (orig.).
Bone integrity and mineral status were studied with a noninvasive method in uremic patients with severe secondary hyperparathyroidism undergoing maintenance hemodialysis.
Changes in radiostrontium clearance (SrC) and bone formation (tetracycline labeling) were observed in the femurs of skeletally mature dogs following the various operative steps involved in bone screw fixation. Drilling, but not periosteal stripping, produced a small but statistically significant increase in SrC and endosteal bone formation in the distal third of the bone. Strontium clearance values equivalent to those produced by drilling alone were recorded after screw fixation at low or high torque (5 versus 20 inch pounds), as well as by the insertion of loosely fitting stainless steel implants. Bone formation (equals the percentage tetracycline-labeled trabecular bone surfaces) was increased by 30% when SrC values exceeded 3.5 ml/100 g bone/min, and the relationship was linear when SrC values ranged between 1.0 and 7.0 ml/100 g ...
This paper examines the seismic signatures of discrete, finite-length fractures, and outlines an approach for elastic, prestack reverse-time imaging of discrete fractures. The results of this study highlight the importance of incorporating fracture-generated P-S converted waves into the imaging method, and presents an alternate imaging condition that can be used in elastic reverse-time imaging when a direct wave is recorded (e.g., for crosswell and VSP acquisition geometries).
Complications of non-union and avascular necrosis during fracture healing process are the most important problems. Early detection of the evidence of non-union and avascular necrosis and follow-up study of fracture healing process will reduce complications and sequellae in fracture patients. Femoral neck and tibial shaft are the most important fracture sites where non-union and/or avascular necorsis are frequently developed. Osteomedullography was performed in 30 cases of fracture, 21 femoral neck, 8 tibial shafts and 1 talar neck, in the Department of Radiology of national Medical Center during the period form August 1977 to March 1981. The following results were obtained: 1. 16 patients of femoral neck fracture were performed osteomedullography one. Non-union showing no crossing vein through the fracture site was noted in 12 cases from 16 ...
A model of weightlessness in which the hindlimbs of rats are elevated by their tails at a 40 degrees angle to unload the hindlimbs while maintaining normal weight bearing on the forelimbs has been used to simulate certain conditions of space flight. When we used this model in growing rats, we found that growth in bone weight ceased by 1 week in the hindlimbs and lumbar vertebrae, whereas growth in bone weight in the forelimbs and cervical vertebrae remained unaffected. Within 2 weeks, however, the accretion of bone weight in the hindlimbs and lumbar vertebrae returned to normal despite continued skeletal unloading. Since bone weight in the growing rat is primarily determined by bone formation (bone resorption is modest), we investigated the effects of selective skeletal unloading on bone formation during 2 weeks of hindlimb elevation using ...
The present work is a research of the effect of helium on the microstructure, mechanical properties and fracture behaviors of a type 316 austenitic steel. Helium implantation was performed by 30-MeV #alpha#-particle injection on very small size specimens, using a cyclotron. Average helium content in a He-deposited region was up to 2000 appm He. In the case of 2000appm He implantation, intergranular fracture was sometimes observed on the helium deposited region after tensile test at room temperature. At elevated temperature test, however, this material showed the transition of fracture mode from transgranular-ductile fracture at 773K to intergranular fracture at 873. In the case of 500 appm He implantation, the transition of fracture mode was recognized at a temperature range of 873K to 973K. (author).
The nucleation and propagation of hydrofractures by injection of over pressured fluids in an elastic and isotropic medium are studied experimentally. Non-Newtonian fluids are injected inside a gelatine whose mechanical properties are assumed isotropic at the experimental strain rates. Linear elastic theory predicts that plastic deformation associated to breakage of gelatin bonds is limited to a small zone ahead of the tip of the propagating fracture and that propagation will be maintained while the fluid pressure exceeds the normal stress to the fracture walls (Ch\\'avez-\\'Alvarez,2008) (i.e., the minimum compressive stress), resulting in a single mode I fracture geometry. However, we observed the propagation of fractures type II and III as well as nucleation of secondary fractures, with oblique to perpendicular trajectories with respect to the initial ...
BackgroundNatural disasters result in significant numbers of disabling impairments. Paradoxically, however, the traditional health system response to natural disasters largely neglects health-related rehabilitation as a strategic intervention.ObjectivesTo examine the role of health-related rehabilitation in natural disaster relief along three lines of inquiry: (1) epidemiology of injury and disability, (2) impact on health and rehabilitation systems, and (3) the assessment and measurement of disability.DesignQualitative literature review and secondary data analysis.ResultsAbsolute numbers of injuries as well as injury to death ratios in natural disasters have increased significantly over the last 40 years. Major impairments requiring health-related rehabilitation include amputations, traumatic brain injuries, spinal cord injuries (SCI), and long bonefractures. Studies show that persons with pre-existing disabilities are more likely to die in a ...
Yucca Mountain, Nevada is a potential site for a high-level radioactive-waste repository. Uncertainty and sensitivity analyses were performed to estimate critical factors in the performance of the site with respect to a criterion in terms of pre-waste-emplacement ground-water travel time. The degree of failure in the analytical model to meet the criterion is sensitive to the estimate of fracture porosity in the upper welded unit of the problem domain. Fracture porosity is derived from a number of more fundamental measurements including fracture frequency, fracture orientation, and the moisture-retention characteristic inferred for the fracture domain.
Back pain from osteoporosis is commonly related to compression fractures. The patient with vertebral compression fractures additionally suffers from an ongoing risk of recurrent fractures and postural abnormalities that can result in impaired respiratory function, leading to increased risk of morbidity. Weakened back muscles, especially the back extensor group, are felt to contribute significantly to this risk. The combination of pharmacologic and nonpharmacologic interventions, through physical activity, exercise, and modalities, are potential interventions that could be used to help reduce the pain of osteoporotic compression fractures as well as potentially reducing recurrent fracture rates.
In this study, bone mineral density (BMD) of normal (CON), ovariectomized (OVX) and partially nephrectomized (NFR) rats was measured by 31P NMR spectroscopy; bone matrix density was...Full Text Available
The paper intends to lay down the fundamentals of normal mineralisation in the perinatal phase as a basis for investigations of disturbed mineralisation. Data are presented on the percentage area of the mineralized osseous tissue, the osteocyte density, and the mineral contents of healthy bones at this age. Comparative morphological examinations of thin bone sections and microradiographs give a picture of bone development at this age. (orig./AJ).
Interferon-γ (IFN-γ) has been shown to enhance anti-tumor immunity and inhibit the formation of bone-resorbing osteoclasts. We evaluated the role of IFN-γ in bone metastases,...Full Text Available
The radiologic appearance of inflammatory and tumorous lesions in the iliac bone is characterized by destructive alterations and consolidations simultaneously. This pattern is nonspecific. The value of plain films of this area is compromised by the anatomy of the iliac bone and by overlying structures. Therefore tomography, computer tomography and bone scans are necessary. Difficulties in differentiation between benign and malignant lesions are discussed and case reports are given. The importance of histologic examination is stressed.
Radionuclide X-ray fluorescence analysis was used for the determination of Sr/Ca ratio in bones to test the influence of a diet on this ratio. Significant differences were observed for Sr/Ca ratio in bones of various animals. Only small differences in the Ca/Sr ratio were observed for the samples of various prehistoric human bones. (author) 4 refs.; 4 tabs.
Using QCT, we made a longitudinal, population-based assessment of rates of bone loss over life at the distal radius, distal tibia, and lumbar spine. Cortical bone loss began in perimenopause in women...Full Text Available
Fifteen quantitative bone scintigraphies were performed in an adolescent girl during the follow-up of a femoral osteogenic sarcoma treated by chemotherapy and massive allograft. Three hours after injection of the radiopharmaceutical (7.4 MBq/kg of 99mTc-MDP) bone activity was measured in the inferior limbs at several regions of interest centered on the hips, femurs (proximal, middle, distal) and proximal tibias. The variations of relative bone activities A/S (ratio of corresponding counting rates between two homologous regions in the affected A and in the healthy S limb) and of absolute bone activities (expressed in counts/pixel-second) are interpreted as a function of times during treatment. The quantitative results are discussed with regard to main phenomena influencing bone activity in this particular clinical case: bone growth, chemotherapy and ...
In an effort to explore Diffraction Enhanced Imaging of bone tissue, experiments were performed to determine if it was possible to use Diffraction Enhanced Imaging to detect microdamage in bovine cortical bone. Measurements were made at the National Synchrotron Light Source where pre- and post-fatigue rocking curve widths of the bone were studied. The rocking curve widths were then compared. Since no consistent pattern of narrowing or broadening of the rocking curve emerged, it is likely that the ultra-small-angle X-ray scattering present in the bone overshadowed any additional changes to rocking curve caused by microdamage of the bone. Larger bone structures were able to be visualized which suggests that microdamage may be visualized with a higher resolution detector.
The aim of this work was to compare dose calculation algorithm results at orthovoltage energies for a phantom composed of a bone slab in water. The calculation methods investigated were: no correction, ETAR, Batho, convolution/superposition and Monte Carlo. All algorithms calculated depth dose curves in a water phantom within 4% of experiment. However in the bone phantom, differences of over 40% between the No Correction / ETAR / Batho / Convolution and Monte Carlo results in the 1 cm thick bone slab were observed. These differences are predominantly because the algorithms do not account for the differing atomic number of the bone compared to water The increased dose to bone and the tissue adjacent to the bone interface should be considered when treating with orthovoltage photons. Copyright (1998) Australasian Physical and Engineering Sciences in Medicine
In acute intoxication, uranium (U) not only inhibits bone formation but its excretion in urine also causes renal damage. The former effect is ameliorated by tetracycline (TC), probably due to its chelation property, which might also prevent U deposition in bone. Chemical determination of U incorporated in bone and a histological study of the kidneys were performed on animals injected with U and then treated with TC. The results showed that TC was unable to prevent the binding of U to bone while it exacerbated U-induced renal damage.
The utilization of nuclear medicine bone scanning examinations early in the diagnostic process allows physicians to render prompt and correct treatment in urgent or difficult athletic cases. Bone scanning should be performed for athletic injuries whenever (1) x-rays are normal but bone or joint pain persists; (2) x-rays are positive but it cannot be determined if the findings are acute or chronic; (3) soft-tissue injuries present and x-rays are not useful; and (4) bone pain or joint impairment present without a history of trauma.89 references.
A case has been presented of an expanding, aggressive bone cyst in the scapula of an 11-year-old girl. The lesion had the appearance of a highly aggressive, cyst-like disorder that appeared to be benign. Biopsy and histological preparation confirmed the presence of a solitary bone cyst. The clinical, radiological, and pathological criteria associated with a solitary bone cyst, particularly in the scapula, were discussed and the literature was reviewed. The differential diagnosis was stressed and a number of examples of scapular lesions was presented radiologically, particularly lesions that might be confused with solitary bone cyst. (orig./SHA).
The governing equations for heat and mass transfer were derived for hydraulically fractured geothermal reservoirs. When converted to nondimensional form it was shown that the equations can be considerably simplified. The resulting equations can be strongly influenced by the effects of buoyancy; the magnitude of the effect is measured by the ratio of the Grashof and Reynolds numbers, and the ratio of the actual permeability of the fracture and the square of the fracture gap width. Significant quantities of energy can be extracted from hydraulic fractures--even without thermal stress fracturing. The amount is limited by the size of the fracture and the low thermal conductivity of rock. The viscous pressure drop in open fractures is insignificant, and depending upon losses in piping and surface equipment, the entire system could be ...
The major effect of immobilization during growth is a smaller bone mass induced by either an increased bone resorption or a decreased bone formation. Using a method of analyzing radioisotopic loss of (/sup 3/H)tetracycline and (/sup 3/H)collagen from bone prelabeled in vivo, we compared the amount of bone resorption due to immobilization with bone resorption induced by growth. One hind limb was denervated in growing male rats, 6 weeks of age, that had been chronically prelabeled with (/sup 3/H)tetracycline, /sup 45/calcium, and (/sup 3/H)proline. The total radioactivity of the whole femur and tibia/fibula from the denervated limb was compared with that from bones of the control limb at 0, 1, 2, 4, and 8 weeks after denervation. The effect of growth on bone formation was measured by net increases in ...
Mineral deposition or alteration is commonly found at fracture-block interfaces is fissured, geothermal reservoirs. In response to pressure reduction in the fissures such mineralization, if less permeable than the matrix rock, will retard the flow of fluid from the blocks to the fissures and is termed fracture skin in this paper. The problem of fluid flow to a production well in a double-porosity reservoir with fracture skin was analyzed theoretically. One of the findings of the analysis was that fully transient block-to-fissure flow can be approximated by pseudo-steady state flow if fracture skin permeability is sufficiently low. Type curves generated by numerical inversion of Laplace transform solutions are used to cooroborate the results of a finite-difference model of steam transport to a well in a naturally fissured, geothermal reservoir with fracture skin.
The understanding of transport processes that occur in naturally fractured geothermal systems is far from being complete. Often, evaluation and numerical simulations of fractured geothermal reservoirs, are carried out by assuming equivalent porous media and homogeneous petrophysical properties within big matrix blocks. The purpose of this paper, is to present a comparison between results obtained from numerical studies of a naturally fractured reservoir treated as a simple porous medium and the simulation of some real aspects of the fractured reservoir. A general conclusion outlines the great practical importance of considering even approximately, the true nature of such systems. Our results show that the homogeneous simplified evaluation of the energy resource in a fractured system, could result in unrealistic estimates of the reservoir capacity to generate ...
The understanding of transport processes that occur in naturally fractured geothermal systems is far from being complete. Often, evaluation and numerical simulations of fractured geothermal reservoirs, are carried out by assuming equivalent porous media and homogeneous petrophysical properties within big matrix blocks. The purpose of this paper, is to present a comparison between results obtained from numerical studies of a naturally fractured reservoir treated as a simple porous medium and the simulation of some real aspects of the fractured reservoir. A general conclusion outlines the great practical importance of considering even approximately, the true nature of such systems. Our results show that the homogeneous simplified evaluation of the energy resource in a fractured system, could result in unrealistic estimates of the reservoir capacity to generate electricity.
The residing fracture system and the prevailing in situ stresses have a significant impact on fluid flow and heat transfer in crystalline rocks. The long term response of fracture systems to changes in effective stresses, in particular the long term geo-mechanical effects of thermal stresses on reservoir characteristics is of particular interest to the geothermal industry.In this paper, a geothermal reservoir model is presented, in which a thermo-poroelastic finite element module is coupled to a fracture geomechanical module. This describes fracture closure as a function of effective stress and the changes in parameters, such as effective permeability, porosity and discrete fracture apertures. The novelty of this approach lies in its dynamic treatment of the characteristic properties of in...
A 52-year-old woman had a history of left hearing loss for 5 years. An acoustic neurinoma with 3.2 cm in diameter was diagnosed and treated with gamma-knife radiosurgery (19 Gy of marginal dose) 1 year and 4 months ago. She developed headache, nausea, and visual disturbance 1 month prior to admission. Slight left facial palsy appeared after radiosurgery. Magnetic resonance imaging demonstrated the tumor with central necrosis in the left cerebellopontine angle cistern, increasing in size to 3.5 cm in diameter, and hydrocephalus. Tumor removal was performed incompletely, because of the fibrous appearance of the tumor and severe adherence with the surrounding cerebellar tissue. Facial palsy did not worsen after surgery. Since the hydrocephalus was not resolved, a right ventriculo-peritoneal shunt was inserted. The clinical course in this case suggests that tumor removal followed by radiosurgery was an approximately effective treatment for large ...
Compact bone makes up approximately 80% of the human skeletal mass. This study examines the effect of estrogen deficiency on compact bone turnover and associated geometrical structural adaptation over a 31-month period in a large animal model. Twenty-seven skeletally mature sheep were divided into control (n = 16) and ovariectomy group (OVX, n = 11). Animals were administered five different fluorochrome dyes to label intracortical bone turnover, and sacrificed at 31 months. Compact bone samples were analyzed for cortical geometry, intracortical turnover at five time points, resorption cavities, porosity, and compressive strength. Intracortical bone turnover was significantly increased in OVX, which demonstrated seasonal variation. Cross-sectional area in OVX was significantly greater than control and was associated with an increased section modulus. Intracortical porosity was ...
The need for noninvasive sensitive techniques for the diagnosis and follow-up of metabolic bone disease in dialysis patients has stimulated the author's interest in the efficacy of more detailed quantitative bone scintigraphy. Using hemodialysis to reduce elevated soft-tissue activity at scintigraphy, an attempt was made to assess the diagnostic sensitivity of quantitative bone scintigraphy as compared to qualitative bone scintigraphic, biochemical, radiographic and bone histologic studies. The second aim of these studies was to determine if one of the two major components of renal osteodystrophy is a major determinant for skeletal radiotracer uptake. The clinical observations on the efficacy and possible specificity of quantitative bone scintigraphy in the diagnosis and follow-up during treatment of renal osteodystrophy are presented briefly in this chapter. ...
Intracapsular femoral neck fractures remain unsolved fractures even after improvement in techniques of diagnosis and internal fixation. Individuals who sustain displaced femoral neck fractures are at high risk of developing avascular necrosis and non-union. Although several methods for predicting the viability of femoral head have been reported, they are not effective or widely used because of unreliability, potential complications and technical difficulties. Dynamic MRI was introduced in the recent past as a simple, non-invasive technique to predict the femoral head viability after the femoral neck fractures. In this study role of dynamic MRI was studied in 30 patients with 31 intracapsular femoral neck fractures. Fractures were divided in to three types according to dynamic curve patterns on MRI evaluation and were followed up for 6 months to 2 years to ...
Intracapsular femoral neck fractures remain unsolved fractures even after improvement in techniques of diagnosis and internal fixation. Individuals who sustain displaced femoral neck fractures are at high risk of developing avascular necrosis and non-union. Although several methods for predicting the viability of femoral head have been reported, they are not effective or widely used because of unreliability, potential complications and technical difficulties. Dynamic MRI was introduced in the recent past as a simple, non-invasive technique to predict the femoral head viability after the femoral neck fractures. In this study role of dynamic MRI was studied in 30 patients with 31 intracapsular femoral neck fractures. Fractures were divided in to three types according to dynamic curve patterns on MRI evaluation and were followed up for 6 months to 2 years to ...
The characteristics of fractures in unit 2 of the Tshirege Member of the Bandelier Tuff were documented in Pit 39, a newly excavated 13.7 m deep disposal pit at Material Disposal Area G on Mesita del Buey. The average spacing between fractures is about 1.0 to 1.3 m, the average fracture aperture is about 3 to 5 mm, and the average fracture dip is about 76o to 77o. Fracture spacing and dip in Pit 39 are generally consistent with that reported from other fracture studies on the Pajarito Plateau, although the fracture apertures in Pit 39 are less than reported elsewhere. Measured fracture orientations are strongly affected by biases imparted by the orientations of the pit walls, which, combined with a small data set, make identification of potential preferred orientations dlfflcult. The most prominent ...
Purpose. To validate a protocol for creating virtual models to be used in the construction of solid prototypes useful for the planning-simulation of maxillo-facial surgery, in particular for very complex anatomical and pathologic problems. To optimize communications between the radiology, engineering and surgical laboratories. Methods and materials. We studied 16 patients with different clinical problems of the maxillo-facial district. Exams were performed with multidetector computed tomography (MDCT) and single slice computed tomography (SDCT) with axial scans and collimation of 0.5-2 mm, and reconstruction interval of 1 mm. Subsequently we performed 2D multiplanar reconstructions and 3D volume-rendering reconstructions. We exported the DICOM images to the engineering laboratory, to recognize and isolate the bony structures by software. With these data the solid prototypes were generated using stereolitography. To date, surgery has been ...
The bone mineral content of 109 lumbar vertebrae from 36 different subjects was determined by dual photon absorptiometry. The mean age of the subjects was 58.5 years (range, 31 to 79 years). The ultimate strength of the vertebral bodies was determined during axial compression. Bone mineral content and ultimate compressive strength were correlated (r = 0.86) and the strength was found to increase linearly with increasing amounts of bone mineral content. No differences in this correlation were found in the four vertebral levels (L-4) included in the study, but a difference in this correlation was found between specimens taken from male and female subjects. The results make it possible to estimate the strength of a vertebral body from the knowledge of its bone mineral content as determined by dual photon absorptiometry and provide a basis of estimations of normal and abnormal amounts of ...
High-energy synchrotron x-ray diffraction (XRD) has been used to quantify load transfer in bovine plexiform bone. By using both wide-angle and small-angle XRD, strains in the mineral as well as the collagen phase of bone were measured as a function of applied compressive stress. We suggest that a greater proportion of the load is borne by the more mineralized woven bone than the lamellar bone as the applied stress increases. With a further increase in stress, load is shed back to the lamellar regions until macroscopic failure occurs. The reported data fit well with reported mechanisms of microdamage accumulation in bovine plexiform bone.
A fragmented fossil bone incised with the figure of a proboscidean was recently found at Vero Beach, Florida near the location where Late Pleistocene fauna and human bones were recovered from 1913 to 1916. This engraving may represent the oldest and only existing example of Terminal Pleistocene art depicting a proboscidean in the Americas. Because of the uniqueness, rarity, and potential antiquity of this specimen, caution demanded that a variety of tests be used in an attempt to verify its authenticity. The mineralized bone was identified as mammoth, mastodon, or giant sloth. Rare earth element analysis was consistent with the fossil bone being ancient and originating at or near the Old Vero site (8-IR-9). Forensic analysis suggests the markings on the bone are not recent. Optical microsc...
Mechanobiological theories have been introduced to illustrate the interaction between biology and the local mechanical environment during bone healing. Although several theories have been proposed, a quantitative validation using histomorphometric data is still missing. In this study, in vivo histological data based on an ovine animal experiment was quantified and used to validate bone healing simulations focussing on the endochondral ossification process. The bone formation at different callus regions (periosteal and endosteal bone at the medial and lateral side) was analyzed from in vivo data and quantitatively compared with in silico results. A histomorphometric difference was found in medial and lateral hard callus formation 3 weeks after osteotomy. However, the same amount of new bone...
Osteoporotic vertebral fractures often lead to pain and disability. They can be successfully treated, and possibly prevented, by injecting cement into the vertebral body, a procedure known as vertebroplasty....Full Text Available
Femur fractures typically affect elderly patients with multiple co-morbidities. Pain control can be difficult, requiring intensive nursing and physician care as elderly patients may manifest cardiovascular...Full Text Available
BackgroundThere have been reports both supporting and refuting an inverse relationship between hip fracture and hip osteoarthritis (OA). We explore this relationship using a case-control...Full Text Available
Hip fractures are associated with a high rate of mortality and profound temporary and sometimes permanent impairment of quality of life. Current guidelines indicate that surgeons should perform surgery...Full Text Available
A scintimetric study using Tc-99m MDP was made of 54 patients with delayed union, nonunion, or late segmental collapse of the femoral head, 4-92 months after femoral neck fracture. In radiographically verified collapse, the radionuclide uptake ratio between the femoral head on the fractured and on the intact side (HHR) was significantly higher than in fractures resulting in delayed union or nonunion. On the basis of scintimetric and radiographic findings, the patients with healing disturbances could be divided into three groups, characterized by the following features: (1) Satisfactory post-reduction position of the fracture without subsequent redisplacement and a high HHR, which as a rule turned out to be delayed union; (2) The same radiographic pattern but with a lower HHR, which in most cases resulted in nonunion; (3) Inadequate reduction or early redisplacement of the fracture ...
Background and purposeRadial head fractures are common, and may be associated with other injuries of clinical importance. We present the results of a standard additional MRI scan...Full Text Available
BackgroundThis case series report discusses patients presenting with hemorrhage and hemodymanic compromise due to severe pelvic fractures and undergoing intraoperative angioembolization...Full Text Available
OBJECTIVE:To evaluate the profile of osteoporosis treatment among patients hospitalized due to hip fractures at a tertiary-level university hospital. To compare the impact of hospitalization...Full Text Available
BackgroundStress fractures are a significant problem among athletes and soldiers and may result in devastating complications or even permanent handicap. Genetic factors may increase...Full Text Available
Background: Intramedullary fixation of midclavicular fractures may be a better option than non-operative treatment for high performance/professional athletes because of the potential reduction...Full Text Available
BackgroundHip dislocation after arthroplasty for femoral neck fractures remains a serious complication. The aim of our study was to investigate the dislocation rate in acute femoral...Full Text Available
The use of cementless threaded cups in THA is a well-established treatment. Fractures of the cups are rare complications recorded in individual cases with material defects being discussed as the primary...Full Text Available
BackgroundThe effects of intervention programs on health-related quality of life (HRQOL) of patients with hip fracture have not been well studied. We hypothesized that older patients...Full Text Available
The Idaho National Engineering Laboratory (INEL) has been conducting geothermal reservoir research and testing sponsored by the US Department of Energy (DOE) since 1983. The INEL research program is primarily aimed at the development of reservoir engineering techniques for fractured geothermal reservoirs. Numerical methods have been developed which allow the simulation of fluid flow and heat transfer in complex fractured reservoirs. Sensitivity studies have illustrated the importance of incorporating the influence of fractures in reservoir simulations. Related efforts include fracture characterization, geochemical reaction kinetics and field testing.
Heat exchange during laminar flow is studied at the fracture scale on the basis of the Stokes equation. We used a synthetic aperture model (a self-affine model) that has been shown to be a realistic geometrical description of the fracture morphology. We developed a numerical modelling using a finite difference scheme of the hydrodynamic flow and its coupling with an advection/conduction description of the fluid heat. As a first step, temperature within the surrounding rock is supposed to be constant. Influence of the fracture roughness on the heat flux through the wall, is estimated and a thermalization length is shown to emerge. Implications for the Soultz-sous-For\\^{e}ts geothermal project are discussed.
Self-expanding metallic stent insertion has been widely applied for the palliative treatment of malignant esophageal strictures. Although it is known as an easy, safe, and effective procedure, complications are well known and include things such as stent migration and esophageal stent occlusion caused by tumor in growth. However, metallic stent fractures have been rarely reported in the esophagus, especially for nitinol stents. We report a case of a stent fracture associated with migration in a patient with a malignant esophageal stricture near the gastroesophageal junction. It is highly probable that the stent fracture was due to chemical erosion of the stent caused by gastric juice
We apply our work on fracture- and matrix-dominated flow to develop a conceptual model of hydrological flow processes in the unsaturated zone at Yucca Mountain. The possibility of fracture-dominated flow is discussed, and various deductions are made on its impact on natural and total system performance, site characterization activities, and site suitability determination.
Different sized ROIs within the femoral head and different modes of calculation were used in (/sup 99m/Tc)MDP scintimetry after femoral neck fracture. In preoperative scintimetry, correction for increased trochanteric uptake gave the best discrimination, whereas in postoperative scintimetry the direct ratio fractured/intact femoral head was superior. The change in ROI size had little influence.
Comprehensive Structural Integrity is a reference work which covers all activities involved in the assurance of structural integrity. It provides engineers and scientists with an unparalleled depth of knowledge in the disciplines involved. The new online Volume 11 is dedicated to the mechanical characteristics of materials. This paper contains the chapter 11.02 of this volume and is structured as follows: Test techniques; Analysis; Fracture behavior; Fracture toughness tests for nonmetals.
Phase II Randomized Study of the Effect of Zoledronate Versus Observation on Bone Mineral Density of the Lumbar Spine in Patients Undergoing Risk-Reducing Excision of Both Ovaries (GOG-0215). See the protocol summary.
This study was designed to evaluate the suitability of a novel bioabsorbable material in treating bone defects. A poly(desaminotyrosyl-tyrosine-ethyl ester carbonate) (PDTE carbonate) membrane (thickness...Full Text Available
Bone-seeking radiopharmaceutical uptake (BSRU) was used to examine alveolar bone metabolism in a longitudinal study of tetracycline efficacy in beagle dogs. BSRU was measured in untreated control dogs and in beagles receiving either 250 mg or 500 mg oral tetracycline-HCl daily for 16 months. The rate of bone loss was determined for radiographs taken semiannually for a 6-month pretreatment period and for a 24-month treatment period. Measurements of BSRU obtained at month 16 of treatment were correlated with rates of bone loss determined radiographically in an attempt to determine whether BSRU was indicative of the subsequent rate of bone loss. A reduced rate of alveolar bone loss was found in the 500 mg tetracycline group at month 16 of the study relative to the untreated controls which was consistent with the decreased bone-seeking ...
This report of progress and future objectives timetable is based on an included schematic of goals and objectives and the project abstract which is included as Appendix 1. Five matters are summarized in the order of (1) novel methods of calcified bone confocal microscopy and reconstruction image analysis of decalcified beagle and human cortical bone serial sections, (2) macroscopic cross-correlation of beagle and human cortical and cancellous bone fractions with CT analysis, (3) guidance to the most radiobiologically important skeletal regions of interest with the just completed {sup 90}Sr bone tumor map from life time beagle studies, (4) deposition patterns of radioactive agents that participate in apatite crystal nucleation processes in bone and leave radiation-excited electrons trapped in bone mineral, and (5) the budget period timetable. The discovery that ...
Accumulated lines of evidence suggest that hyperimmune responses to periodontal bacteria result in the destruction of periodontal connective tissue and alveolar bone. The etiological roles of periodontal...Full Text Available
Platelet-derived growth factor (PDGF) is a potent moderator of soft tissue repair through induction of the inflammatory phase of repair and subsequent enhanced collagen deposition. We examined the effect...Full Text Available
Bone loss associated with estrogen depletion is well documented in cancellous bone but less well characterized in cortical bone. The effects of ovariectomy on the aged beagle skeleton were studied by histomorphometric analysis of the cortical bone in sequential rib biopsies. Biopsies were taken from each ovariectomized or sham-operated dog at the time of surgery and at 1, 4, and 8.5 months after surgery. Just prior to each postoperative biopsy, tetracycline, calcein, and xylenol orange, respectively, were administered by a fluorochrome labeling procedure (2d-10d-2d) to provide markers of bone formation. Analysis of sequential rib biopsies provided a means to follow the ovariectomy response over time and to compare each animal against its own baseline. Though ovariectomy did not influence histomorphometric indices at 1 month after surgery, a transient increase in cortical ...
Osterix (Osx) is a zinc-finger-containing transcription factor that is expressed in osteoblasts of all endochondral and membranous bones. In Osx null ...Full Text Available
Bone metastasis of primary colorectal cancer is uncommon. When it occurs, it is usually a late manifestation of disease and is indicative of poor prognosis. We describe a patient with multiple metachronous...Full Text Available
In regions of high bone loading, the mechanoresponsive osteocytes inhibit osteoclastic bone resorption by producing signaling molecules. One possible candidate is matrix extracellular phosphoglycoprotein...Full Text Available
BackgroundPeak bone mass, attained by early adulthood, is influenced by genetic and life-style factors. Early infant feeding and duration of breastfeeding in particular, associate...Full Text Available
Previous experimental data from various laboratories indicate that endotoxin of gram-negative oral microorganisms might be one of the most important bacterial products involved in bone resorption during...Full Text Available
Osteoblasts are the primary cells responsible for bone formation. They also support osteoclast formation from bone marrow precursors in response to osteotropic factors by inducing receptor activator...Full Text Available
Genetic effects on mechanical properties have been demonstrated in rodents, but not confirmed in primates. Our aim was to quantify the proportion of variation in vertebral trabecular bone mechanical...Full Text Available
BackgroundSarcoma encompasses an uncommon group of cancer and the data is insufficient from Pakistan. We report our four years experience of Sarcoma of soft tissues and bones.MethodsThis...Full Text Available
BackgroundDifferences in duration of bone healing in various parts of the human skeleton are common experience for orthopaedic surgeons. The reason for these differences is not obvious...Full Text Available
Objectives To assess the effectiveness of calcium supplementation for improving bone mineral density in healthy children and to determine if any effect is modified by other factors and...Full Text Available
OBJECTIVEHormonal contraceptives may adversely affect bone mineral density . However, racial differences and the reversibility of these changes are poorly understood....Full Text Available
The measurement of bone loss in patients undergoing maintenance dialysis over a period of two and a half years is reported. The tendency to lose bone is a likely event in renal failure, but depends...Full Text Available
To determine the relative importance of different metabolites of vitamin D in bone growth and development, weanling male rat pups suckled by vitamin D-deficient mothers were given either calcitriol...Full Text Available
BackgroundHip resurfacing arthroplasty (HRA) is considered a bone-preserving procedure and may eliminate proximal femoral stress shielding and osteolysis. However, in addition to...Full Text Available
Low bone mineral density (BMD) is prevalent in human immunodeficiency virus (HIV)–infected subjects. Initiation of antiretroviral therapy is associated with a 2%–6% decrease...Full Text Available
To assess the effects of increasing the mineral content of parenteral nutrition solutions on the biochemical and radiological indicators of metabolic bone disease of prematurity 27 neonates who required...Full Text Available
This study assessed the feasibility of measuring tiludronate in horses using a minimally invasive bone biopsy technique. Eight horses were treated with intravenous (IV) tiludronate [1 mg/kg bodyweight...Full Text Available
Ewing's sarcoma classically presents as a hot spot on bone scan as a result of increased vascularity of the tumor and new bone formation. Purpose We report and analyze an uncommon pattern of a 'cold' lesion in Ewing's sarcoma on bone scan and its pathophysiologic significance. Case report A 15-year-old boy complaining of thigh pain. CT scan evoked Ewing's sarcoma or osteitis. MRI evoked chronic osteitis. Scintigraphy showed a fairly intense and heterogeneous uptake on the femoral lesion and no abnormal uptake elsewhere. Biopsy showed none pathologic pattern. Three months later, a second biopsy concluded to Ewing's sarcoma. Bone scan showed a larger lesion with peripheral intense uptake centered by enlarged 'cold' area in the left femoral diaphysis and no evident bone metastasis. The patient underwent chemotherapy and surgery. Three months later, bone scan showed ...
BackgroundBacterial constituents, such as Gram-negative derived lipopolysaccharide (LPS), can initiate inflammatory bone loss through induction of host-derived inflammatory...Full Text Available
The symbiotic polychaetes of the genus Osedax living on the bones of whale carcasses have become known as bone-eating worms. It is believed that whale bones are the source of nutrition for those gutless worms and that fatty acids are produced by their symbionts and transferred to the host. However, the symbionts are of the heterotrophic group Oceanospirillales and as such are not able to synthesize organic carbon de novo. Also, they are not housed in close contact to the bone material. We studied the ultrastructure of the integument overlying the symbiont housing trophosome in the ovisac region and the roots region and of the symbiont-free trunk region of Osedax to investigate the hosts possible contribution in feeding for the whole symbiosis. The epidermis differs conspicuously between th...
The bone mineral areal content and the ultimate compressive strength were determined in 109 lumbar vertebrae from 36 subjects. The bone mineral areal content was related to the number, shape, and localization of the Schmorl's nodes detected in the x-rayed and sectioned vertebral bodies. One type of node, irregular in shape and localization, occurred only in the vertebrae with low bone mineral areal content values and thus in vertebrae with relatively low compressive strength. A second type of Schmorl's nodes, regular in shape and localization, did not reflect any general weakness of the vertebral bodies. PMID:6623194
While bone metastases producing photon deficient defects on bone scintigraphy have previously been reported, this finding has not been emphasized for hepatocellular carcinoma (HCC). Furthermore, ''filling-in'' of such photon deficient defects with 67Ga at skeletal sites of metastatic HCC has not been described. In this case report, the combination of a photon deficient defect on bone scintigraphy and avid accumulation of 67Ga in this same area was of value in confirming the diagnosis of metastatic HCC.
The effect of protein malnutrition on the metabolism of collagen in bone was studied in young female albino rats after a single injection of "3H-proline. Both specific and total radioactivities of hydroxyproline in the total collagen of the bone were found to decrease in the protein-deficient animals, indicating decreased rate of collagen synthesis. In the urine the amount of hydroxyproline excreted and total radioactivity of "3H-hydroxyproline were greatly decreased. The results of the present investigation therefore clearly indicate decreased synthesis and catabolism of collagen in bones of protein deficient animals compared to controls. (auth.).
In this study, the influence of Beryllium (Be) content on the fracture behaviour of Al?15%Mg2Si composite was investigated. The results showed an increase in mechanical properties with increasing of Be content. The stress?strain curves of samples showed a same category of serrations reflecting non-uniform deformation. Scanning electron microscopy was employed to examine the crack nucleation and fracture model. The results indicate that Al?15%Mg2Si composite shows different behaviours of crack initiation and fracture for samples with and without Be. Differences observed in the fracture behaviour were attributed to microstructural changes as well as morphological aspects of primary Mg2Si particles.
Natural fractures and in situ stresses commonly dictate subsurface reservoir permeability and permeability anisotropy, as well as the effectiveness of stimulation techniques in low-permeability, natural gas reservoirs. This paper offers an initial prediction for the orientations of the fracture and stress systems in the tight gas reservoirs of the Frontier Formation, in the Green River basin of southwestern Wyoming. It builds on a previous report that addressed fractures and stresses in the western part of the basin and on ideas developed for the rest of the basin, using the principle that thrust faults are capable of affecting the stress magnitudes and orientations in little-deformed strata several hundreds of kilometers in front of a thrust. The prediction of subsurface stresses and natural fracture orientations is an undertaking that requires the willingness to revise models as definitive data are ...
Forty-five patients with recent cervical hip fractures were included in a prospective, clinical, radiographic and sequential scintimetric study. Striking changes in radionuclide uptake over the entire hip region on the fracture side were found during the first 5 postoperative months. Fractures that healed without complications showed the highest relative femoral head uptake at 1 week and a peak value at 6 weeks, followed by a gradual decline at the subsequent examinations. Fractures with complications (redisplacement, nonunion, or late segmental collapse) showed a lower initial uptake and a more gradual increase and only a slight tendency towards increased uptake after 3 months. The accuracy in predicting nonunion with scintimetric examination alone is high both at 1 and at 6 weeks, and the accuracy is almost equally high with combined scintimetric, radiographic, and clinical assessment 3-5 months ...
Zirconia-toughened sialon composites have been fabricated using conventional hot-pressing techniques. The fracture toughness and microstructure were determined for CeO_2- and Y_2O_3-stabilized ZrO_2 additives and also as a function of volume percent ZrO_2. The Yttria system showed a linear increase in fracture toughness with increasing volume fraction zirconia content while the ceria-stabilized system exhibited a peak in fracture toughness at 20 vol% ZrO_2 content. The fracture toughness at 800 C was measured and correlated with the microstructure. High-temperature stability was determined and it was found that the deleterious nitride phases of zirconium could be precluded from the microstructure.
This paper presents a procedure for transferring the CTOD fracture toughness obtained from laboratory specimens to an equivalent CTOD for structural components, taking constraint loss into account. The Weibull stress criterion is applied to correct the CTOD for constraint loss, which leads to an equivalent CTOD ratio, b, defined as b=d/dWP, where d and dWP are CTODs of the standard fracture toughness specimen and the structural component, respectively, at the same level of the Weibull stress. The CTOD ratio b is intended to apply to the fracture assessment of ferritic steel components to stress levels beyond small-scale yielding. Nomographs are given to determine the b-value as a function of the crack type and size in the component, the yield-to-tensile ratio of the material and the Weibul...
In this work, a pre-cracked semi-circular shaped explosive simulant was loaded using a split Hopkinson pressure bar (SHPB). A high-speed camera was used to capture the deformation and fracture process of the specimen in situ. The digital images were processed using the digital image correlation (DIC) method. Next, full displacement and strain fields were obtained. The displacement vector field shows that the specimen fractured under tensile stress action. The strain field can be used to predict the crack propagation. Results show that the method of combined DIC and SHPB is effective to study the dynamic deformation and fracture behavior of explosive simulants. In addition, the specimen was loaded using a drop weight. The fracture toughness of the specimen was preliminary measured.
We conduct the static and dynamic loading fracture experiments on magnesium alloy (AZ31B) under the equitable and inequitable biaxial stress. We process specimens as cross type with cracks. There are different kinds of cracks defined by their crack angles. By using a hydraulic high-speed biaxial experiment machine, we put the equitable and inequitable stresses on the specimen. We analyze results using the caustic method. The experiments reveal a few important results. There is negative correlation between the fracture toughness value and the plate thickness in the magnesium alloy sheet specimen. The fracture toughness value decrease in the case the crack has the angle different from the loading direction. The fracture toughness value decreases significantly under the inequitable biaxial stress. (orig.)
A model is developed to represent mechanical strain, stress-enhanced dissolution, and shear dilation as innately hysteretic and interlinked processes in rough contacting fractures. The model is incorporated into a numerical simulator designed to examine permeability change and thermal exchange in chemically active and deformable fractured reservoirs. A candidate engineered geothermal reservoir system (EGS) is targeted. The mechanistic model is able to distinguish differences between the evolution of fluid transmission characteristics of (1) small scale, closely spaced fractures, and (2) large-scale, more widely spaced fractures. Alternate realizations of fracture frequency and scale, exhibiting identical initial bulk permeability, lead to significantly different conclusions regarding perme...
In a retrospective study of 21 patients, in whom the acetabular fractures were suspected on initial radiographs, we compared and analysed the computed tomographic findings and plain radiographic findings. The results were as follow: 1. In patients with multiple trauma, no further change in position was required during CT examinations. 2. CT showed intraarticular loose bodies, which were invisible on plain radiographs. 3. CT was useful in detecting the fractures of acetabular rims, medial wall of acetabulum, and femoral head. 4. CT permitted better evaluation of shape, extent, and degree of separation of fracture fragments. 5. CT was helpful in detecting the associated fractures and soft tissue injuries. 6. CT also demonstrated the adequacy of reduction, the position of metallic fixation devices, and the presence or absence of remaining intraarticular osseous fragments after surgery.
Ewing's sarcoma and Triton's tumor are two uncommon bone tumors of the skull that have nonspecific clinical and imaging features. However, imaging methods are important in the detection of the lesions during the diagnostic investigation in order to evaluate the extent of the bone lesions, involvement of the soft tissues and brain, and to determine the presence of local recurrence and metastases. The confirmatory diagnosis relies on histological studies and immunohistochemistry. The authors report two cases of patients with these tumors and present the radiological findings. (author)
The results of treatment of 53 cases of pediatric localized Ewing's sarcoma and bone reticulosarcoma were analized. Chemoradiotherapy is a procerdure of choice in bone marrow sarcoma treatment: while overall five-year survival was 28.4#+-#6.2%, it was as high as 64.9% in cases of combined treatment (total focal dose of at least 50 Gy+polychemotherapy). Two cases of osteo- and chondrosarcoma development in exposed bone are described.
Previous investigations have shown that both the early biological response and the mechanical properties of a porous hydroxyapatite bone graft substitute are highly sensitive to its pore structure. The objective of this study was to evaluate whether the pore structure continued to influence bone integration in the medium to long term. Two screened batches of porous hydroxyapatite (PHA) designated as batch A and batch B, with porosities of approximately 60 and 80%, respectively, were selected for this study and implanted for periods of 5, 13, and 26 weeks into the lower femur of New Zealand White rabbits. Histomorphometric analysis of the absolute volume of bone ingrowth within batch A and B implants from 5 to 26 weeks showed that the absolute volume of bone ingrowth was consistently lower in batch A (10-21%), compared to batch B implants (24-31%). However, when the volume of bone ...
Cell therapy is a promising novel option for treatment of cardiovascular disease. Because the role of bone marrow-derived circulating progenitor cells (BM-CPCs) after cell therapy is less clear, we...Full Text Available
We have examined spontaneous secretion of IgE by human rib bone marrow mononuclear cells (MNC). Bone marrow MNC from nine out of 12 rib specimens synthesized and secreted substantial amounts of IgE...Full Text Available
Mutations of ephrin B1 in humans result in craniofrontonasal syndrome. Because little is known of the role and mechanism of action of ephrin B1 in bone, we examined the function of osteoblast-produced...Full Text Available
Parathyroid hormone (PTH) is used clinically in osteoporotic patients to increase bone mass by enhancing bone formation. PTH therapy is not uniformly effective at all skeletal sites and “lifestyle”...Full Text Available
The authors present a case in which primary Ewing's sarcoma of the right petrous pyramid in a 9-year-old girl showed no uptake on a /sup 99m/Tc-pertechnetate nuclide angiogram. Intense uptake was present on a /sup 99m/Tc-polyphosphate bone scan, but a static brain scan was only minimally abnormal. The diagnosis and treatment of Ewing's sarcoma are reviewed.
A bone scan can be negative in Ewing's sarcoma. The bone scan during and after treatment can give prognostic information on the primary tumor site: A persisting hot spot strongly suggests the presence of local malignancy, while a hot spot becomming negative points to local cure of Ewing's sarcoma. (orig.).
Between 25 and 30 percent of total known petroleum reserves are contained within oil-laden fractured reservoirs where the dominant flow path is through the fractures. Economic oil recoveries from fractured reservoirs depend on a better understanding of the flow in fractures and networks of fractures. However, the flow of heavy oil and water, and particularly the flow regime map for two-phase immiscible flow has received less attention in contrast with gas-liquid flow in fractures. This paper discussed the use of flow pattern observations in a Hele-Shaw cell to generate two-phase flow regime maps. The paper investigated the effect of fracture gap and fluid viscosities on flow regimes. A correlation based on different flow and fracture properties was developed to define flow transition conditions between flow regimes. The ...
Identifying stable isotope variation and mineralogical changes in fractured rock may help establish the history of climatic and geomorphological processes that might affect the isolation properties of a waste repository site. This study examines the use of the stable isotope ratios of oxygen ({sup 18}O/{sup 16}O) and carbon ({sup 13}C/{sup 12}C) in authigenic minerals as hydrogeochemical tools tracing low-temperature rock-water interaction in variably-saturated fractured stuff. Isotopic compositions of fracture-filling and rock matrix minerals in the Apache Leap tuff, near Superior, Arizona were concordant with geothermal temperatures and in equilibrium with water isotopically similar to present-day meteoric water and groundwater. Oxygen and carbon isotope ratios of fracture-filling, in unsaturated fractured tuff, displayed an isotopic gradient believed to result from near-surface ...
A central issue to be addressed within the Nevada Nuclear Waste Storage Investigations (NNWSI) is the role which fractures will play as the variably saturated, fractured rock mass surrounding the waste package responds to heating, cooling, and episodic infiltration events. Understanding the role of fractures during such events will, in part, depend on our ability to make geophysical measurements of perturbations in the moisture distribution in the vicinity of fractures. In this study we first examine the details of the perturbation in the moisture distribution in and around a fracture subjected to an episodic infiltration event, and then integrate that behavior over the scale at which moisture measurements are likely to be made during the Engineered Barrier Design Test of the NNWSI project. To model this system we use the TOUGH hydrothermal code and fracture and ...
The objective of this study was to evaluate the role of collagen membrane and Bio-Oss coverage in healing of an onlay graft to the mandible. Twelve adult sheep each received an onlay bone graft (experiment 1), bone graft+Bio-Gide (experiment 2), and bone graft+Bio-Oss/Bio-Gide (experiment 3) on the lateral surface of the mandible. The animals were euthanized at 4, 8, 12 or 16 weeks after surgery, and findings were analysed by routine microscopy and immunohistochemistry for proliferation (Ki67) and apoptotic (Caspase-3) markers. Grafts were fully incorporated in all specimens. Pronounced resorption was observed in experiment 1. Minimal loss of graft volume was seen in experiment 2 specimens without membrane displacement. A remarkable increase in the augmented region of the mandible was obse...
This study evaluated the clinical efficacy of treatment with oral risedronate (17.5?mg once daily) for 8?weeks in 11 Japanese patients with Paget?s disease of bone (PDB). Risedronate suppressed the excessive bone turnover associated with PDB and improved several biochemical markers, including serum alkaline phosphatase (ALP), serum bone-specific ALP (BALP), urinary deoxypyridinoline (DPD), and urinary cross-linked N-telopeptide of type 1 collagen (NTX). These markers began to decrease within about 2?weeks after the initiation of treatment in most patients, and the response persisted for up to 40?weeks after the cessation of treatment. Risedronate reduced pain by week 24 in most patients. According to quantitative bone scintigraphy, the lesion with the highest radioisotope (RI) uptake showe...
Tc-MDP 10mCi was intravenously given preoperatively to 20 patients with primary bone tumors and 1 with a metastatic bone tumor. Preoperative and postoperative scintigraphs of resected tumor and scintigraphs of sliced tumor were compared. Tissue fragments were collected from the sliced tumor, and RI measured to compare concentration rates at different areas. Histological investigations were also done. Localization of Tc-MDP was increased at sites of tumorous bone formation, of reactive bone formation at tumor edges, and of cartilage calcification, with little concentration at tumor cells or necrotic tissue. VX/sub 2/ carcinoma was transplanted into the rabbit tibia, Tc-MDP was intravenously injected when bone destruction was radiologically evident, and investigations were done as in the clinical cases. In experimental bone tumor, increased uptake localization of ...
Bone formation and resorption have been measured in patients with idiopathic osteoporosis by histomorphometry of 7.5-mm trephine biopsies and in the whole body by 85Sr radiotracer methodology and calcium balances. The studies were synchronized and most were preceded by double in vivo tetracycline labeling. Correlations between histological and kinetic bone formation indices were better when better when based on the extent of double tetracycline labels than on measurements of osteoid by visible light microscopy. Correction of the kinetic data for long-term exchange, using 5 months' serial whole body counting of retained 85Sr, improved the fit of the kinetic to the histological data. A statistical analysis of the measurement uncertainties showed that the residual scatter in the best correlations (between exchange-corrected bone formation rates and double-labeled osteoid surface indices) could be attributed to ...
Tumor necrosis factor alpha (TNF-alpha) and interleukin-1 (IL-1) have been shown to stimulate bone resorption in vitro. We have now investigated whether these cytokines also cause a similar action when administered in vivo. This was made possible by the adaptation of a newly developed technique that enables the continual assessment of bone resorption in vivo in mice by measuring urinary excretion of {sup 3}H from ({sup 3}H)tetracycline-prelabeled animals. Experiments using maneuvers known to influence bone resorption, such as a change in dietary calcium or administration of parathyroid hormone or dichloromethylenebisphosphonate, indicate that the technique is reliable and sensitive in mice. Daily intravenous administration of either recombinant human or recombinant murine TNF-alpha, as well as subcutaneous administration of recombinant human IL-1 alpha, were found to stimulate bone resorption in a ...
The ultimate compressive strength and modulus of elasticity of femoral cortical bone from adult geese (Anser anser), were determined by sex and by quadrant by compressing small right circular cylinders which were 2.4 mm in height and 0.8 mm in diameter. The average ultimate compressive strength was 183 +/- 29 MPa. The average modulus of elasticity was 13.2 +/- 3.4 GPa. The bending strength and bending modulus of elasticity were determined by a three point bend test on rectangular prisms which had the approximate dimensions 0.75 mm X 0.75 mm X 25 mm. The average bending strength was 263 +/- 44 MPa while the average bending modulus was 19.6 +/- 3.1 GPa. The calcium content was determined by atomic absorption spectrophotometry and no correlation was found with the mechanical properties. The histology of the cortical bone was examined both quantitatively and qualitatively. A unique type of Haversian bone is described. Goose ...
A new microdensitometry method for quantitative assessment of bone mineral content using Fuji computed radiography (FCR) was developed and the results were compared with those obtained by the conventional film-screen method. Using both methods, X-ray pictures of the 2nd metacarpal bone were taken with a reference aluminum step wedge in nine normal subjects and nine parameters representing the width and density of bone marrow and cortex were calculated in middle of the bone shaft. Interobserver reproducibility assessed for three parameters was significantly higher in the FCR method than the conventional one. The value of {Sigma}GS computed by the FCR method, that is equivalent to the net bone density of the transverse section of the shaft, showed higher correlation with the one obtained by computed tomography in comparison with the conventional method. In our FCR method, moreover, ...
A new microdensitometry method for quantitative assessment of bone mineral content using Fuji computed radiography (FCR) was developed and the results were compared with those obtained by the conventional film-screen method. Using both methods, X-ray pictures of the 2nd metacarpal bone were taken with a reference aluminum step wedge in nine normal subjects and nine parameters representing the width and density of bone marrow and cortex were calculated in middle of the bone shaft. Interobserver reproducibility assessed for three parameters was significantly higher in the FCR method than the conventional one. The value of #SIGMA#GS computed by the FCR method, that is equivalent to the net bone density of the transverse section of the shaft, showed higher correlation with the one obtained by computed tomography in comparison with the conventional method. In our FCR method, moreover, ...
Anatomical specimens and normal persons were studied by gradient echo MR imaging to determine the influence of different echo times (TE) on bone marrow contrast. First of all, six normal persons were studied to determine specific echo times for in-phase and opposed-phase states. Using different sequences bone marrow contrast in isolated femoral bones was determined and compared to results of pathological exams. Red bone marrow had no signal on opposed-phase images; contrast between red and yellow marrow was higher on opposed-phase than on in-phase images. Bone marrow lesions can be expected to be visualised with high signal on opposed-phase images; this technique should be especially suited for MR imaging of bone marrow. (orig.).
The author studied the conditions needed to routinely estimate the radiation dose in chicken bone by repeated re-irradiation and measuring ESR signals. Chicken meat containing bone was {gamma}-irradiated at doses of up to 3kGy, accepted as the commercially used dose. The results show that points in sample preparation and ESR measurement are as follows: Both ends of bone are cut off and central part of compact bone is used for experiment. To obtain accurate ESR spectrum, marrow should be scraped out completely. Sample bone fragments of 1-2mm particle size and ca.100mg are recommended to obtain stable and maximum signal. In practice, by re-irradiating up to 5kGy and extrapolating data of the signal intensity to zero using linear regression analysis, radiation dose is estimated. For example, in one experiment, estimated doses of chicken bones initially irradiated ...
The circulation in microvascularized rib grafts has been compared with that in conventional rib grafts and in those augmented by a direct vascular bundle implantation into the bone grafts. A new experimental model has been designed to correlate vascular perfusion, bone scan patterns, tetracycline labeling, and histological findings in these bone grafts. Posterior microvascularized rib grafts were found to have a circulatory pattern identical to that of the normal rib. Failed microvascularized rib grafts were revascularized more slowly than conventional rib grafts. Vascular bundles implanted into rib grafts remained patent and increased the rate of revascularization. The stripping or preservation of periosteum had no observable effects on the rate or pattern of conventional rib graft revascularization. The circulation in rib grafts was accurately reflected in technetium 99 bone scans, as was the patency ...
Superplasticity can be generally achieved by grain boundary sliding (GBS). The GBS in polycrystalline materials sometimes accompanies with intergranular fracture because of stress concentrations at triple points and/or GB irregularities. To develop the superplastic flow, it is necessary to suppress the intergranular cracking. In the present study, therefore, polycrystalline molybdenum with distinct GB microstructures, such as grain boundary character distribution (GBCD), has been employed to clarify the relationship between fracture behaviour and GB microstructures. Microstructures were analyzed using a FE-SEM/EBSP/OIM system prior to 4-points bending tests at 77K, thereafter, crack propagation was observed. The main results obtained are as follows. Stress fluctuations on stress - strain curves were observed for specimens with random oriented grains, whereas such behaviour rarely occurred for ones with textured grains. Difference in the ...
This case report describes the treatment of a 16-year-old girl who had severe bialveolar protrusion. Patients with bialveolar protrusion are commonly treated with four first premolar extractions and retraction of the anterior teeth. Unfortunately in this patient, the mandibular left second molar had to be extracted because of extensive caries. To create sufficient space for retraction of the anterior teeth, the mandibular left posterior teeth were retracted with the mandibular posterior microimplant (1.2 mm in diameter, 6 mm long) placed into the retromolar area followed by en masse retraction of the mandibular anterior teeth. Microimplants can provide anchorage for obtaining a good facial profile even without premolar extraction in the case of bialveolar protrusion with the absence of the second molar. PMID:17319776
In recent years, slightly acid formulas for cosmetics which remove follicular infundibulum obstruction of the hair follicle, have been devised. Therefore, few acne patients experience a problem with cosmetics use. On the other hand, cosmetics use differs from person to person. Thus, an investigation of actual conditions of cosmetics use was done among acne patients. Compared with healthy people, acne patients used more facial wash products more. It has been understood that treatment and skincare instruction are important for the improvement and prevention of acne. We examined skin physiology function and patient's QOL by using a skin care product for women for two months with skincare instruction from a dermatologist for 31 female patients this time. As a result, it was able to be confirme...
The studied coal bearing series has a parallel origin. The following facial complexes are isolated in its composition: lakes free of vegetation without coal interlayers; overgrown lakes of their margins which are poor in coals; swampy lakes, whose peat beds formed coal layers of shallow or moderate depth; channel sediments without coal layers and swamps from between channel spaces which created thick coal strata of high quality for which, however, a strong changeability in thickness is intrinsic. The coal strata are normally split towards the central parts of the lake basins and river channels. The coal presence of the suite is reduced along the section which is associated with the replacement of the lake swamp conditions of sedimentation by lake river conditions. A paleotectonic analysis established that the distribution of the zones richest in coal was controlled by consedimentational structural elements.
Background: Ecchymosis, oedema, haematoma and pain after SMAS-based facelift surgery are all the direct result of the physical trauma of surgery and subsequent inflammatory response. Hilotherapy is a novel form of cryotherapy that purports to minimise these events through single-use face masks circulating cooled, sterile water. This study was performed to assess the validity of Hilotherapy in this population of patients. Methods: Over 14 weeks fifty consecutive patients were randomised to post-operative facial cooling with Hilotherapy or management with standard dressings alone, while fifteen subsequent, consecutive patients were randomised to cooling of one side of the face but not the other. Assessment of ecchymosis, oedema, haematoma and pain was performed independently by clinical staf...
Abstract The aim was to utilize data from a study of occupational indoor environments to analyze symptoms and physiological signs in relation to the home environment. A medical investigation was performed at the workplace among university staff (n = 173) from four university buildings in Bergen, in March 2004. Tear film break up time (BUT) was measured by two methods. Nasal patency was measured by acoustic rhinometry. Nasal lavage fluid analysis (NAL) included eosinophilic cationic protein (ECP); myeloperoxidase (MPO), lysozyme and albumin. Atopy was assessed by total serum IgE and specific IgE (Phadiatop). Totally 21%, 21%, 18%, 11%, and 27% had weekly ocular, nasal, facial dermal symptoms, headache and tiredness, respectively, 15% had a damp dwelling, and 20% had a cat or dog. Multiple l...
Many studies on multisensory processes have focused on performance in simplified experimental situations, with a single stimulus in each sensory modality. However, these results cannot necessarily be applied to explain our perceptual behavior in natural scenes where various signals exist within one sensory modality. We investigated the role of audio-visual syllable congruency on participants? auditory localization bias or the ventriloquism effect using spoken utterances and two videos of a talking face. Salience of facial movements was also manipulated. Results indicated that more salient visual utterances attracted participants? auditory localization. Congruent pairing of audio-visual utterances elicited greater localization bias than incongruent pairing, while previous studies have repor...
In this paper we focus on appearance features describing the manual component of Sign Language particularly the Local Binary Patterns. We compare the performance of these features with geometric moments describing the trajectory and shape of hands. Since the non-manual component is also very important for sign recognition we localize facial landmarks via Active Shape Model combined with Landmark detector that increases the robustness of model fitting. We test the recognition performance of individual features and their combinations on a database consisting of 11 signers and 23 signs with several repetitions. Local Binary Patterns outperform the geometric moments. When the features are combined we achieve a recognition rate up to 99.75% for signer dependent tests and 57.54% for signer indep...
The authors used studies of local cerebral metabolic rate for glucose (LCMRGlc) to examine development of cerebral organization in 5 days to 1 year old children. A group (n=8) of infants with diverse pediatric disorders allowed investigation of developmental changes in LCMRGlc, while also providing relevant clinical management information. Patients consisted of questionable and definite neonatal seizures, cerebral embolism from cardiac sources, and otherwise normal infants with facial nevi with consideration of Sturge-Weber. Gradual increase in cortical LCMRGlc coincides with suppression of intrinsic subcortical reflexes present in all newborns. Two retarded children (2 years old) showed LCMRGlc developmental patterns of a few days old, which corresponded to their functional and mental status. These studies illustrate great potential of PET to study normal and altered states of human brain development.
IntroductionMost clinical studies on the outcome of apical surgery concentrate on periapical healing based on radiographic and clinical characteristics (signs and symptoms). This study focuses on long-term changes in periodontal parameters after apical surgery. MethodsPeriodontal parameters (ie, probing depth [PD], level of gingival margin [GM], and calculated clinical attachment level [CAL]) were collected at baseline and at 1 and 5 years after apical surgery. Changes in PD, GM, and CAL were calculated over time and were also evaluated in relation to patient-, tooth-, and treatment-related covariables. ResultsOne hundred eighty-six of 242 initially identified teeth could be evaluated. Significant changes in GM and CAL were observed at facial sites during the first year after surgery (mean...
Bimaxillary protrusion is prevalent among Asians and anterior segmental osteotomies are commonly used for its surgical correction. The objective of this study was to evaluate the soft tissue changes resulting from anterior segmental osteotomies. The electronic databases PubMed, Scopus and ISI Web of knowledge were searched for potentially eligible studies using a set of predetermined keywords. Full texts meeting the inclusion criteria were retrieved and their references were manually searched for additional relevant articles. The study details and outcome data of these reports were extracted using spreadsheets for comparison. The methodological quality of each study was assessed. Eleven studies met the inclusion criteria. Lateral cephalometry was used in all studies. A reduction of the lab...
The extended mind thesis (EM) asserts that some cognitive processes are (partially) composed of actions consisting of the manipulation and exploitation of environmental structures. Might some processes at the root of social cognition have a similarly extended structure? In this paper, I argue that social cognition is fundamentally an interactive form of space management-the negotiation and management of "we-space"-and that some of the expressive actions involved in the negotiation and management of we-space (gesture, touch, facial and whole-body expressions) drive basic processes of interpersonal understanding and thus do genuine social-cognitive work. Social interaction is a kind of extended social cognition, driven and at least partially constituted by environmental (non-neural) scaffold...
PurposeThe purpose of this study was to determine the relationship between the changes of soft and hard tissues after modified anterior segmental osteotomy on the maxilla and mandible and to evaluate unintended facial changes using cephalometric and photometric analyses.Materials and MethodsThe subjects included 29 women and 1 man (22 to 50 years of age) who were diagnosed as bialveolar or bimaxillary protrusion and underwent modified anterior segmental osteotomy on the maxilla and mandible. Lateral cephalograms and lateral and frontal photographs taken preoperatively and postoperatively were analyzed.ResultsThere was a significant change in all soft and hard tissue parameters except the labiomental angle. The ratio of upper lip to maxillary incisor retraction was 0.67:1 and the ratio of l...
We have developed a playmate robot system for playing the rock-paper-scissors game with humans. The playmate robot recognizes the hand motions of a human using image processing without attaching any additional units to the human. The playmate robot system consists of three parts: a game management part, a hand motion recognition part, and a robot hand control part. The system functions as follows. (1) Before the game is played, the game management part decides on the motion of the robot hand from amongst rock, paper, and scissors. After the game is played, the robot develops a reaction using speech and facial expressions depending on the result of the game. (2) The hand motion recognition part recognizes the hand motion of the human. It does not use any additional units on the human?s body...
Renal osteodystrophy is a metabolic bone disease and a common complication of end-stage chronic renal failure and maintenance dialysis treatment. In this study, we examined the correlation between quantifying bone scintigraphy and serum biochemical markers in hemodialysis patients. Bone scintigraphy with technetium-99m-hydroxy-methylene-diphosphonate ("9"9"mTc-HMDP) was performed on 28 patients on maintenance hemodialysis. Bone scintigraphy was performed using a standard protocol and was quantified by setting regions of interest (ROIs) over selected regions. The bone-to-soft-tissue ratio (B/ST ratio) at each region was calculated in all patients. The B/ST ratios were then compared with serum biochemical markers. The B/ST ratio for the skull correlated well with serum bone-specific alkaline phosphatase (BAP) (r=0.735, p<0.001), serum deoxypyridinoline (DPD) ...
Today, the use of the arch bars in the treatment of mandibular fractures is common [1]. But it has complications such as damaged teeth, periodontal tissue [2], risk of blood transmitted disease [3] and premature contact with maxillary incisor teeth in anterior deep bite occlusion. Many techniques are used for resolving these problems. In this paper, we describe the technique of using Maxillo-Mandibular Fixation Screws (MMFS) with essig wiring of anterior mandibular teeth in the management of symphyseal fracture of deep bite patients.
Strain rate effects for the high strength, metastable beta-titanium alloy Ti-8Mo-8V-2Fe-3Al are assessed in terms of tensile and fracture toughness behavior. It is shown that as the strain rate increases the yield strength, ultimate tensile strength, and ductility also increase. As a result of the decrease in the amount of intergranular fracture as the strain rate is increased, the dynamic fracture toughness values K/sub Id/ are greater than those obtained under static conditions as given by K/sub Q/.
Two patients with femoral neck fractures, one displaced and one undisplaced, are presented. Preoperative intravital staining with tetracycline and Tc-MDP scintimetry both showed intact femoral head circulation while Tc-MDP-scintimetry 1 week after operation showed pronounced circulatory deficiency. Sr/sup 85/-scintimetry performed at the same time was inconclusive. Segmental collapse was observed radiographically, 8 and 12 months postoperatively. The major vascular injury resulting in avascularity most probably occured during the procedure of osteosynthesis, and Tc-MDP-scintimetry was found suitable for early postoperative recognition of avascular necrosis in both fractures.
Two patients with femoral neck fractures, one displaced and one undisplaced, are presented. Preoperative intravital staining with tetracycline and Tc-MDP scintimetry both showed intact femoral head circulation while Tc-MDP-scintimetry 1 week after operation showed pronounced circulatory deficiency. SR"8"5-scintimetry performed at the same time was inconclusive. Segmental collapse was observed radiographically, 8 and 12 months postoperatively. The major vascular injury resulting in avascularity most probably occured during the procedure of osteosynthesis, and Tc-MDP-scintimetry was found suitable for early postoperative recognition of avascular necrosis in both fractures. (author).
The objectives of this paper are to: quickly outline the extent of the care gap in osteoporosis; define T-2 (knowledge) translation and its relationship to quality improvement; discuss the barriers to best practice in osteoporosis care after a fracture; convey the importance of rigor in design and evaluation of translational interventions by drawing upon examples from the broader literature; describe in some detail a series of post-fracture intervention trials conducted in Alberta, Canada; and make some conclusions specifically about osteoporosis interventions and more generally about T-2 translational research.
BackgroundThe routine removal of orthopaedic fixation devices after fracture healing remains an issue of debate. There are no evidence-based guidelines on this matter, and little...Full Text Available
The effect of helium on the mechanical properties and fracture behaviors of a type 316 austenitic steel is presented. Helium implantation was performed by 30-MeV #alpha#-particle injection on very small, thin specimens, using a cyclotron accelerator. Average helium content in the He-deposited region was 50 to 2000 appm He. These specimens showed the transition of fracture mode from transgranular to intergranular fracture in elevated temperature tests. The transition temperature decreased with increase in the amount of implanted helium. For example, in the case of 2000 appm and 500 appm He implantation, the transition temperatures were between 773 and 873 K and 873 and 973 K, respectively. (orig.).
The tests reported were part of the DOE Geothermal Reservoir Well Stimulation Program. This East Mesa (Imperial Valley, CA) well was successfully stimulated with two fracture treatments, a dendritic fracture and a planar fracture. The natural flow production of the well increased 114 percent, to 197,900 lb/hr. These tests were among the few successful attempts of this program to increase flow from geothermal production wells. The general belief is that these tests worked OK primarily because the formation was sedimentary rock (similar to rock in most oil and gas wells that have been stimulated successfully. Similar tests in geothermal hard rock reservoirs did not work very well. (DJE 2005)
To evaluate injury patterns of facet joints and associated soft tissue injuries in patients with acute traumatic cervical facet joint injuries. From among patients with cervical spine trauma, 27 with facet joint injuries, as seen on CT and MRI, were chosen for this study. CT scans were analyzed with regard to the location of facet joint injury, the presence or absence of facet dislocation or fracture, and other associated fractures. MR images were analyzed with regard to ligament injury, intervertebral disc injury, intervertebral disc herniation, and spinal cord injury. The most common location of facet joint injury was C6-7 level(n=10), followed by C5-6(n=8). Among these 27 patients with facet joint injuries, 12(44%) had bilateral injuries and 15(56%) unilateral injuries. Facet fractures were present in 17 cases(63%) and the fracture of inferior facet was more frequent than superior. Patterns of ...
The fatigue and fracture behavior of hard tissues are topics of considerable interest today. This special group of organic materials comprises the highly mineralized and load-bearing tissues...Full Text Available
Background There is increasing recognition that lower nurse staffing levels are associated with higher morbidity and mortality among medical and surgical patients. The degree to which this applies to elderly patients with hip fractures is unclear. Questions/purposes We conducted a pilot study using administrative data as an initial step in investigating the relationship between nurse staffing levels and in-hospital mortality among elderly patients with hip fractures. Patients and Methods We retrospectively reviewed administrative data for 13,343 patients 65?years or older with a primary diagnosis of hip fracture admitted to 39 Michigan hospitals between 2003 and 2006. We used logistic regression to calculate the change in predicted probability of in-hospital death conferred by differences ...
Osteoporosis is accompanied by predominantly metaphyseal fractures with a delayed and qualitatively reduced healing process. This study addressed the question of whether fracture healing in the context of osteoporosis prophylaxis is improved with estrogen (E) or alendronate (ALN). Thirty-six ovariectomized and 12 sham-operated 12-week-old rats received soy-free (osteoporotic C, sham), E-, or ALN- supplemented diets. After 10?weeks, a metaphyseal tibia osteotomy and standardized T-plate fixation were performed. After a 5-week healing process, the fracture callus was evaluated qualitatively by biomechanical bending test and quantitatively in microradiographic sections. The time course of callus formation was examined using fluorochrome-labeled histological sections. Administration of E impro...
Development drilling from Chevron-operated Platform Hermosa, located on OCS-P 0316 of the Point Arguello field, began on January 30, 1987. To date, seven development wells have been drilled in to the northwest-southeast-trending, doubly plunging anticlinal structure. The results from drilling have confirmed the presence of intense folding and fracturing in the targeted Monterey Formation. Over 700 ft of conventional core were recovered from the B-2 well in the lower Sisquoc and Monterey Formations. Analysis of the core material has yielded important information on lithologic variations and fracture patterns in the productive Monterey Formation. Initial results of core studies, DST data, and wireline studies indicate a correlation between rock type and fracturing. Fracture trends and directional permeability suggested by drill-stem testing may affect future drilling patterns in the field.
ABSTRACT Crack tip opening angle (CTOA) is becoming one of the most accepted methods for characterizing fully plastic fracture. It provides a measure of the resistance to fracture for a material in cases where there is a large degree of stable-tearing crack extension during the fracture process. Our current pipeline research uses the CTOA test as an alternative, or addition, to the CTOD (crack tip opening displacement) and the fracture energy characterization provided by the J-integral approach. A test technique was developed for measurement of CTOA that uses a modified double cantilever beam (MDCB) specimen. A digital camera and image analysis software were used to record the progression of the crack tip and to estimate the CTOA. In this article, CTOA data on crack growth orientations per...
During a high speed road traffic accident, a 26-year-old man suffered multiple fractures of his thoracic vertebrae and bilateral pneumothoraces. The day after admission and commencement of nasogastric...Full Text Available
Experimental results of quasi-static and dynamic fracture of particle-filled polymer composite (PFPCM) "ALTUGLAS EI CH25" with a matrix of polymethylmethacrylate (PMMA) are reported in this paper. PMMA matrix is filled with rubber particles, as result a shock-resistant transparent composite is produced. The main task was to investigate experimentally and theoretically the fracture toughness of this composite under static and dynamic loading. A high-rate loading has been created by impulse magnetic field. Analysis of fracture process and its relation with the load parameters and material microstructure have been established. Application of the original testing method enabled determination of fracture toughness at very short loading times and comparison of the results with material dynamic p...
The dominant fracture parameters used in fracture mechanics analyses of pipelines are related to the asymptotic crack-tip stress and strain fields at the crack tip. This paper reviewed new developments in constraint-sensitive fracture mechanics for the assessment of pipeline girth weld integrity. Constraint theories and experimental studies were evaluated. Constraint models included brittle fracture models and ductile fracture models. Constraint models for brittle fracture are based on weakest link statistics and Weibull distribution. Specifically designed experimental tests are often necessary to derive the damage parameters of ductile fracture models. Experimental test data must then be calibrated with finite element analyses (FEA) to ensure that the correct damage parameters are chosen. The effects of specimen geometry and loading ...
PurposeThis prospective study followed 61 patients who were partially dentulous and considered to have insufficient bone volume for routine implant treatment and consequently underwent sinus inlay bone grafting.Patients and MethodsThe patients were treated with maxillary sinus floor augmentation with particulated autogenous bone from the mandibular ramus/corpus. After a healing period, dental implants (n = 180) were installed.ResultsRadiographic examination revealed average residual vertical bone heights of 6.5 mm in the first premolar region, 3.8 mm in the second premolar region, 3.5 mm in the first molar region, and 2.6 mm in the second molar region. The average implant lengths were 12 mm in the first premolar region and 11 mm in the second premolar, first, and second molar regions. All ...
The number and type of stem cells in spleen and bone marrow of mice were determined after exposure to a single dose of 150 R on day 6, to a single dose of 500 R on day 6 or day 9 or to a fractionated dose of 150 R + 350 R on day 6 and 9. The stem cells were assayed on the basis of colony forming units (CFU) in spleen and of incorporation of iododeoxyuridine in spleen and bone marrow of lethally irradiated host mice. During the first month of life, the number of stem cells in non-irradiated mice increases markedly in bone marrow and slightly in spleen. Irradiation causes a long-lasting depression in stem cells, particularly in bone marrow and affecting preferentially erythropoietic precursor cells. Following a dose of only 150 R, the number of CFU in bone marrow is still below control levels 24 days later. An exposure to 500 R fractionated between day 6 and 9 has a markedly greater ...
Staging bone scans or skeletal surveys were obtained of 97 patients with endometrial carcinoma. Of the 77 patients with Stage I or II disease, no metastases were identified at staging. Three patients in the entire series demonstrated bony metastases; all of these metastases were detectable by radionuclide bone scan and radiographic bone survey. Eighty-nine patients were examined with radionuclide liver/spleen scanning at the time of staging. Four of the 89 initial scans were interpreted as demonstrating hepatocellular disease, and all four patients had abnormal liver function studies. Only one patient demonstrated a possible hepatic metastasis at initial diagnosis. This patient also had abnormal liver function studies. Based on these results, bone surveys and radionuclide bone scans are not indicated as screening procedures in endometrial carcinoma. It is suggested that screening ...
Quantitative bone scans were evaluated in 16 patients with osteoporosis and in a control group of 7 healthy subjects. Along with a detailed biochemical analysis of calcium-phosphorus metabolism and standartized reongenographs, a quantitative dynamic bone scintigraphy was performed according to the method proposed by the authors. The bone-accumulating factor K_b was determined on the base of mathematical analysis of the graph reflecting activity changes in bone tissue unit during the investigation, the blood-elimination factor K_h and kidney-elimination factor K_k. In addition the accumulation index AI (in %) was calculated as a relation between the activity in bone tissue unit, registered in 20 min interval, and the activity in soft tissues for the same time. Whereas the static gamma camera scintigraphy, made 3-4 hrs after injecting of the osteotrope radiopharmaceuticals, showed no ...
Artificial bone cements (BCs) based on poly(methyl methacrylate) (PMMA) powders and methyl methacrylate (MMA) liquid monomer also present in their formulation small amounts of other substances, including a chemical initiator compound and radiopaque agents. Because inadequate mixing of the recipe components during the manufacture of the bone cement may compromise the mechanical properties of the final pieces, new techniques to incorporate the fillers into the BC and their effect upon the mechanical properties of BC pieces were investigated in the present study. PMMA powder composites were produced in situ in the reaction vessel by addition of X-ray contrasts to the reacting MMA mixture. It is shown that this can lead to much better mechanical properties of test pieces, when compared to standard bone cement formulations, because enhanced dispersion of the radiopaque agents can be achieved. Moreover, it is shown that the ...
Radionuclide X-ray fluorescence analysis (XFA) was used in the determination of the contents of metal residues in dosing plates for coin minting. XFA was also used for the determination of the strontium/calcium ratio in bone samples of different animals with the aim to obtain information on the food composition of these animals. It was found that bones of different animals can be distinguished based on the Sr/Ca ratio. No significant differences in the Sr/Ca ratio were observed in human bones of individuals from different social groups. (author). 1 fig., 5 tabs., 4 refs.
Depletion of stratospheric ozone increases irradiance of terrestrial ultraviolet (UV) radiation at short wavelengths, which may be harmful to the human health. To understand quantitatively the risks caused by increasing UV radiation to the Finnish population, the actual UV exposure of the population has to be assessed. It was shown that the snow reflection increases the UV exposure to the face and eyes particularly in the northern Finland. In 1993 exceptionally low ozone levels persisted up to the end of May, which resulted in a theoretical increase in the annual UV dose ranging from 8 % to 13 % in Finland. The maximal increase in the measured erythemally effective dose rate was 34 % on 23 April, when compared with the theoretical normal value. During this study exposure models have been developed. The models have been combined them with Green`s radiation transfer model to estimate annual facial UV doses received by different groups of Finnish population. Also, an ...
The adequacy of the nasopharyngeal airway has been found to be related to craniofacial development. Obstruction of the airway by adenoid tissue, nasal septal deviation or abnormal morphology of the area is associated with characteristic changes in craniofacial morphology such as long anterior face height, facial retrognathism, and a steep inclination of mandibular plane often with a high vaulted palate and crossbite. Some studies have shown the changes to be reversible after adenoidectomy which improves nasal airway patency and a control mechanism for facial growth has been proposed to account for the relationships between airway adequacy, craniofacial morphology and craniocervical postural relationships. It is therefore important to be able to measure nasal respiratory resistance so that the effect of operative procedures in the area such as rapid maxillary expansion (RME) can be determined. Nasal respiratory resistance (NRR) is a measure of ...
The adverse effects of aging of other organs (ovaries at menopause) on the skeleton are well known, but ironically little is known of skeletal aging itself. Evidence indicates that age-related...Full Text Available
Vitamin D is now known to be of physiological importance outside of bone health and calcium homeostasis, and there is mounting evidence that it plays a beneficial role in the prevention and/or treatment...Full Text Available
Measurements of the retention of /sup 47/Ca and of /sup 203/Pb were made following their administration by intravenous injection. Translocation to bone was measured by ..gamma.. counting the feet of subjects. Uptake by bone of /sup 203/Pb was comparatively slow and extrapolation to the whole skeleton indicated that 20% of the dose has been taken up within 20 days. By time, a similar fraction of the dose has been excreted in urine. Uptake by bone of /sup 47/Ca was about 1.5-2 times the amount excreted in urine. Both the uptake by bone, and its excretion in urine, were more rapid than that of /sup 203/Pb due to the greater attachment of the latter to red blood cells. However, the plasma clearance rate for Pb, like that of Sr, was greater than that of Ca.
Bone is a complex, highly structured, mechanically active, three-dimensional (3-D) tissue composed of cellular and matrix elements. We previously published a report on in situ collagen gelation using a rotary 3-D culture system (CG-RC system) for the construction of large tissue specimens. The objective of the current study was to evaluate the feasibility of bone tissue engineering using our CG-RC system. Osteoblasts from the calvaria of newborn Wistar rats were cultured in the CG-RC system for up to 3 wk. The engineered 3-D tissues were implanted into the backs of nude mice and calvarial round bone defects in Wistar rats. Cell metabolic activity, mineralization, and bone-related proteins were measured in vitro in the engineered 3-D tissues. Also, the in vivo histological features of the transplanted, engineered 3-D tissues were evaluated in the animal models. We found that metabolic activity increased ...
Hypophosphatasia is a congenital disease characterized by deficiency of serum and tissue non-specific alkaline phosphatase activity. The disease occurs due to mutations in the liver/bone/kidney alkaline...Full Text Available
Effect of different factors on survival of patients with Ewing sarcoma (20 people), primary bone reticulosarcoma (43) and myeloma (10) of pelvic bones, has been studied. Independently of the method of treatment, the rate of 3-year survival from reticulosarcoma start constituted (31.5+-7.1)%, Ewing sarcoma - (33.0+-10.8)%, myeloma - (36.0+-15.9)%. Index of 5-year survival in case of reticulosarcoma constituted (20.9+-6.4)%, Ewing sarcoma - (23.6+-11.0)%, myeloma - (36.0+-15.9)%. Improvement of delayed results after prophylactic therapy courses is pointed out. Degree of pelvic bone affection is of a very important prognostic value.
Experiments were designed to elucidate whether or not the irradiated bone marrow cells receive any stimulation for the self-replication and differentiation from normal 'stromal' cell colonies in the bone marrow cell culture in vitro. When irradiated or unirradiated bone marrow cells were overlaid on the normal adherent cell colonies, the proliferation of haemopoietic stem cells was supported, the degree of the stimulation depending on the starting cellular concentration. There was, however, no significant changes in the concentration of either CFUs or CFUc regardless of the dose of irradiation on the bone marrow cells overlaid. This was a great contrast to the dose-dependent decrease of CFUs or CFUc within the culture in which both the stem cells and stromal cells were simultaneously irradiated. These results suggest that the balance of self-replication and differentiation of the ...
The results of a histological study of normal osteoid tissue in man, the monkey, the dog, and the rat, using thin microtome sections of plastic-embedded undecalcified bone, are described. Osteoid tissue...Full Text Available
(Materials and Methods) (I) VX/sub 2/ carcinoma was transplanted to the rabbit tibia, sup(99m)Tc-MDP was intravenously injected when bone destruction was radiologically seen. Preoperative scintigraphs, postoperative one of the resected tibia and fibra and scintigraphs of sliced tumor were compared with each other. Tissue fragments were collected from the sliced tumor, and RI was measured to compare concentration rates at different parts together with histological investigations. (II) Tetracycline was given to the rabbit of Experiment (I) to compare with the concentration of sup(99m)Tc-MDP. (III) Microautoradiography method was done on the experimental animals for investigation of the concentration of sup(99m)Tc-MDP. (Results) (I) Localization of sup(99m)Tc-MDP was increased at the sites of tumorous bone formation, of reactive bone formation at tumor edges, and of cartilage calcification, with little concentration at tumor ...
Hypertrophic osteoarthropathy (HOA) characterised by arthralgia, clubbing and periosteal proliferation of long bones, is rarely encountered in children and adolescents. Whereas in adults over 80% of...Full Text Available
Direct radiological measurements of the mineral content of femoral bone were performed in 13 patients on maintenance dialysis. They were found to be sufficiently sensitive to be used for monitoring,...Full Text Available
Ewing's sarcoma is a malignant bone tumor that can occur anywhere in the body, but it is most commonly observed in the long bones of the arms and legs, the pelvis and in the chest. The predominant sites of metastasis include the lung (38%), bone (including the spine; 31%), and the bone marrow (11%). Metastasis of Ewing's sarcoma to the central nervous system (CNS) is relatively rare, and most of the previous reports have demonstrated involvement of the bony calvarium or brain parenchyma. We describe here the imaging findings of dural metastasis of Ewing's sarcoma, and these imaging findings have not been previously reported on in the medical literature. In conclusion, dural metastasis of Ewing's sarcoma is very rare and its imaging characteristics are similar to those of a primary tumor, which mimic the findings of a schwannoma or meningioma. Despite its rarity, secondary Ewing's sarcoma may be included ...
Rheumatoid arthritis (RA) is a debilitating autoimmune disease of global prevalence. The disease is characterized by synovial inflammation leading to cartilage and bone damage. Most of the conventional...Full Text Available
The purpose of this study was to investigate whether hydroxyapatite (HAp) coating could induce polyethylene terephthalate (PET) artificial ligament graft osseointegration in the bone tunnel. Twenty-four New Zealand white rabbits underwent artificial ligament graft transplantation in bilateral proximal tibia tunnels. One limb was implanted with HAp-coated PET graft, and the contralateral limb was implanted with non-HAp-coated PET graft as control. The rabbits were randomly sacrificed at four and eight?weeks after surgery. The loads to failure of the experimental group at eight?weeks were significantly higher than those of the control group (p?=?0.0057). Histologically, application of HAp coating induced new bone formation between graft and bone at eight?weeks compared with the controls. Rea...
Objectives To investigate the feasibility and reproducibility of measurements of nasal bone length using a three-dimensional (3D) ultrasound in the first trimester. Methods In a prospective study, 118 consecutive pregnant women attending for Down syndrome screening at 11-13 + 6 weeks were recruited. They had successful fetal nasal bone measurement by two-dimensional (2D) ultrasound by four operators. Three-dimensional volumes were recorded in the mid-sagittal plane of fetal profile by the fifth operator and examined using multiplanar techniques. Another independent investigator randomly compared his measurements with one of the four operators. Results In the subsequent 3D examination, the nasal bone length could be examined in 94 cases (79.7%). The mean difference between the 2D and 3D mea...
Abstract Mammalian teeth exhibit incremental structures representing successive forming fronts of enamel at varying time scales, including a short daily increment called a cross striation and a long period called a stria of Retzius, the latter of which, in humans, occurs on average every 8-9 days. The number of daily increments between striae is called the repeat interval, which is the same period as that required to form one increment of bone, i.e. the lamella, the fundamental - if not archetypal - unit of bone. Lamellae of known formation time nevertheless vary in width, and thus their measures provide time-calibrated growth rate variability. We measured growth rate variability for as many as 6 years of continuously forming primary incremental lamellar bone from midshaft femur histologic...
In 15 patients (16 hip joints) we found the clinical and radiological signs of BMOS. On T1-weighted MRI images areas of low signal intensity could be observed in the head, neck and the intertrochanteric region of the femur in various extensions. These areas showed a significant increase in signal intensity on the T2-weighted images. Because pain was resistant to conservative therapy all these patients were treated by core decompression of the femoral head in a prospective study. Bone cores were evaluated histologically using undecalcified sections and quantitative microradiography. The existence of intramedullary oedema in exactly the regions exhibiting the MRI pattern of bone marrow oedema was verified histologically; however, bone and marrow changes similar to those of early avascular necrosis (AVN) were also visible. (orig.)
Background: Apheresis is a procedure to selectively obtain blood components. For the collection process citrate is routinely used. It inhibits coagulation by binding to ionized calcium and leads to metabolic alkalosis. Objective: Whether regular apheresis affects bone and mineral metabolism is unknown. The intention of this study was to investigate 1) the acute effects of apheresis on acid-base balance, bone and mineral metabolism and 2) to compare bone mineral density (BMD) at the lumbar spine and hip of donors to matched control subjects. Design: In this open, observational, single-center, cross-sectional study we enrolled 102 regular plasma and thrombocyte donors to pursue objective 1) and compared those to 102 matched controls (CTR) for objective 2). Results: Platelet donation led to s...
The concept of unstable burst fracture has been discussed since over 50 years and this injury has received much attention in the literature as regards its radiological diagnosis and clinical treatment. The purpose of this article is to review the way we use imaging to diagnose the injury and to guide treatment.
We wanted to evaluate the status of self-expandable nitinol stents implanted in the P2 and P3 segments of the popliteal artery in Korean patients. We retrospectively analyzed 189 consecutive patients who underwent endovascular treatment for steno occlusive lesions in the femoropopliteal artery from July 2003 to March 2009, and 18 patients who underwent stent placement in popliteal arterial P2 and P3 segments were finally enrolled. Lesion patency was evaluated by ultrasound or CT angiography, and stent fracture was assessed by plain X-rays at 1, 3, 6 and 12 months and annually thereafter. At the 1-month follow-up, stent fracture (Type 2) was seen in one limb (up to P3, 1 of 18, 6%) and it was identified in seven limbs at the 3-month follow-up (Type 2, Type 3, Type 4) (n = 1: up to P2: n = 6: P3). At the 6-month follow-up, one more fracture (Type 1) (up to P3) was noted. At the 1-year follow-up, there were no additional stent ...
The radiation life time of reactor pressure vessel (RPV) is the most important limiting factor for the term of exploitation of the whole power unit. The main degradation mechanism of RPV metal is the neutron induced embrittlement. Processes of radiation ageing running in RPV metal lead to fracture toughness decrease and to increased probability of brittle fracture of the vessel under thermal shocks. This explains the importance of RPV integrity assessment and rest life time management
Simultaneous bilateral femoral neck fractures are extremely rare and associated with various conditions. Up to now Most cases had correlations with major trauma, repetitive minor trauma, seizure, parathyroid...Full Text Available
Delirium occurs in up to 65% of older hip fracture patients. Developing delirium in hospital has been associated with a variety of adverse outcomes. Trials have shown that multi-component preventive...Full Text Available
In accordance with the Nuclear Regulatory Commission regulation regarding groundwater travel times at geologic repositories, various models of unsaturated flow in fractured tuff have been developed and implemented to assess groundwater travel times at the potential repository at Yucca Mountain, Nevada. Kaplan used one-dimensional models to describe the uncertainty and sensitivity of travel times to various processes at Yucca Mountain. Robey and Arnold et al. used a two-dimensional equivalent continuum model (ECM) with inter- and intra-unit heterogeneity in an attempt to assess fast-flow paths through the unsaturated, fractured tuff at Yucca Mountain (GWTT-94). However, significant flow through the fractures in previous models was not simulated due to the characteristics of the ECM, which requires the matrix to be nearly saturated before flow through the fractures is initiated. In the current study ...
A 2-year follow-up regarding healing complications, such as redisplacement, nonunion, and segmental collapse of the femoral head, was performed in 306 patients operated on for femoral neck fracture and examined with /sup 99m/Technetium-MDP scintimetry within 2 weeks postoperatively. Scintimetric evaluation was performed by selecting regions of interest over the femoral head on the fracture side and the intact side and by comparing the uptake. A femoral head ratio fractured/intact side thus was obtained. Of 199 patients with an intact femoral head uptake (ratio less than or equal to 1.0), 181 showed no signs of healing complications at 2 years, whereas 18 had developed healing complications. Of 107 cases with a deficient femoral-head uptake (ratio < 1.0), 96 had developed healing complications within 2 years from the operation, while 11 cases had no signs of radiographic complications. We conclude that /sup 99m/Tc-MDP ...
A 2-year follow-up regarding healing complications, such as redisplacement, nonunion, and segmental collapse of the femoral head, was performed in 306 patients operated on for femoral neck fracture and examined with "9"9"mTechnetium-MDP scintimetry within 2 weeks postoperatively. Scintimetric evaluation was performed by selecting regions of interest over the femoral head on the fracture side and the intact side and by comparing the uptake. A femoral head ratio fractured/intact side thus was obtained. Of 199 patients with an intact femoral head uptake (ratio #<=# 1.0), 181 showed no signs of healing complications at 2 years, whereas 18 had developed healing complications. Of 107 cases with a deficient femoral-head uptake (ratio < 1.0), 96 had developed healing complications within 2 years from the operation, while 11 cases had no signs of radiographic complications. We conclude that "9"9"mTc-MDP scintimetry performed ...
Fourteen patients with cervical hip fractures were treated with internal fixation using titanium screws. The femoral head vitality was evaluated with "9"9Tc"m-MDP scintigraphy and scintimetry within 2 weeks postoperatively and by serial low field magnetic resonance imaging (MR). Two patients with reduced radionuclide uptake (femoral head ratio =# 1.0), MR revealed a focal decrease of the signal intensity in the femoral head or neck at 2, 3 and 7 months after fracture, respectively. The radiographs in one of these patients were normal at 7 months after fracture. The second one showed signs of necrosis at 16 months and the last one developed delayed/non-union. With a non-ferromagnetic osteosynthesis the healing course after femoral neck fracture can be studied with low field MR equipment without disturbing artifacts. The time period between ischaemia and definite abnormalities on MR may embrace several ...
Three kinds of thin AZ31 wrought magnesium alloys sheets were used in order to investigate the influence of the second phase particles on fracture toughness. From the theoretical model, the ratio of {lambda}{sub p}/d{sub p} would be estimated 5 {proportional_to} 6. On the other hand, from the microstructural observation, average particle spacing on each material was sample A: 13.1 {mu}m, sample B: 14.1, and sample C: 12 {mu}. In addition, average particle size on each sample was sample A: 2.1, sample B: 1.9, and sample C: 2.3 {mu}m. Therefore, the ratio of {lambda}{sub p}/d{sub p} calculated from fracture surface observation would be predicted 6 {proportional_to} 7. In comparison with the result of the prediction by theoretical analysis was in good agreement with the result of fracture toughness observation. It was found that the variation in plane-strain fracture toughness on AZ31 were affected by both ...
Femoral head vitality before, during and at various intervals from the operation was determined by tetracycline labeling and/or _9_9 sp (m)Tc-MDP scintimetry. In a three-year follow-up, healing prognosis could be determined by scintimetry 3 weeks from operation; deficient femoral head vitality predicting healing complications and retained vitality predicting uncomplicated healing. A comparison between pre- and postoperative scintimetry indicated that further impairment of the femoral head vitality could be caused by the operative procedure, and as tetracycline labeling prior to and after fracture reduction in 370 fractures proved equivalent, it was concluded that the procedure of osteosynthesis probably was responsible for capsular vessel injury, using a four-flanged nail. The four-flanged nail was compared with a low-traumatic method of osteosynthesis, two hook-pins, in a prospective randomized 14 month study, and the postoperative femoral ...
Stromal cells from DBA/2 mouse bone marrow have been shown to be susceptible to cytotoxicity induced by several redox-active metabolites of benzene, including hydroquinone (HQ). Treatment with HQ also...Full Text Available
The author reports 10 studies concerning the diagnosis of renal osteodystrophy and extraskeletal calcification in patients on maintenance hemodialysis as well as some aspects of persistent hyperparathyroidism after renal transplantation. The majority of the studies focus on the value of bone scintigraphy with Tc-99m HEDP in the diagnosis of these disorders. (Auth.).
The Wnt signaling pathway is a robust regulator of skeletal homeostasis. Gain-of-function mutations promote high bone mass, whereas loss of Lrp5 or Lrp6 co-receptors decrease bone mass. Similarly, mutations...Full Text Available
A survey to determine the annual genetically significant dose and mean bone-marrow dose to the Australian population from radiological procedures has been undertaken. For diagnostic radiology the following were carried out: determination of the frequency of a procedure; measurement of patient doses using TLD and processing of data and calculation of gonadal and bone-marrow doses.
Cytologic smears obtained by needle aspiration biopsy of lytic bone lesions in 15 patients with histiocytosis X, Ewing's sarcoma and neuroblastoma were reviewed. After conventional staining, histiocytosis X could be diagnosed and differentiated from small cell tumours such as Ewing's sarcoma and neuroblastoma. The need for sampling material for cytochemical and ultrastructural analysis of these small cell tumours by needle aspiration is emphasized. (Auth.).
Rats that inhaled "2"3"9Pu(NO_3)_4 or "2"3"8Pu(NO_3)_4 developed lung tumors and bone tumors. Lung tumors were clearly associated with Pu inhalation (accumulated dose to lung, 1 rad to 5000 rads); bone tumors could not be unequivocally related to the radiation insult.
We performed biomechanical comparison of a xenograft bone plate-screw (XBPS) system for achieving cadaveric lumbar transpedicular stabilization (TS) in dogs. Twenty dogs' cadaveric L2-4 lumbar...Full Text Available
The purpose of this study was to examine the relationship between histomorphometric variables of cancellous bone structure and ultimate compressive strength (UCS) in the second lumbar vertebra (L2) and to determine whether structural variables in the iliac crest are predictive of the same variables and of UCS in L2. At autopsy, 7.5 mm diameter cores were removed from the iliac crest and from L2 of 29 subjects who had died suddenly without bone disease. Cancellous bone volume (BV/TV, %) was significantly lower in L2 than in iliac crest due to lower trabecular number (Tb.N, per mm) and thickness (Tb.Th, microns). There were significant correlations between iliac crest and L2 for BV/TV, Tb.N and trabecular separation (Tb.Sp, microns), but not for Tb.Th. BV/TV was negatively correlated, and Tb.Sp was positively correlated with age at both sites. Tb.Th was not significantly correlated with age in the iliac crest, but a ...
The effect of various forms of treatment of renal osteodystrophy was evaluated in 25 dialysis patients by quantitative bone scintigraphy, using 99m-Tc-HEDP. The results were compared with those of biochemical and bone morphometric studies. The total skeletal activity (TSA) decreased in 5 patients after transplantation, in 11 after parathyroidectomy and in 6 out of 9 treated conservatively, but did not normalize in any of the patients. Bone morphometric evaluation of treatment, which could be performed in 19 of the 20 patients who did not receive a transplant, demonstrated a reduction in the degree of hyperparathyroidism in 17 patients (89 percent). Osteoid excess was reduced in 13 patients (68 percent) but an evident reduction of osteomalacic osteoid, i.e. improvement of osteomalacia, occurred in only 4 patients (21 percent). Changes in the TSA correlated significantly with the changes in the biochemical and histological ...
The effect of various forms of treatment of renal osteodystrophy was evaluated in 25 dialysis patients by quantitative bone scintigraphy, using 99m-Tc-HEDP. The results were compared with those of biochemical and bone morphometric studies. The total skeletal activity (TSA) decreased in 5 patients after transplantation, in 11 after parathyroidectomy and in 6 out of 9 treated conservatively, but did not normalize in any of the patients. Bone morphometric evaluation of treatment, which could be performed in 19 of the 20 patients who did not receive a transplant, demonstrated a reduction in the degree of hyperparathyroidism in 17 patients (89 per cent). Osteoid excess was reduced in 13 patients (68 per cent) but an evident reduction of osteomalacic osteoid, i.e. improvement of osteomalacia, occurred in only 4 patients (21 per cent). Changes in the TSA correlated significantly with the changes in the biochemical and histological ...
Thirty-four patients with prostatic carcinoma were studied with quantitative bone scintigraphy and whole-body counting (WBC) 1 and 24 h after injection of [sup 99m]Tc-MDP before as well as two weeks and two months after orchiectomy. Thirteen of the patients had normal bone scintigrams and WBR at the three different investigations; 21 had skeletal metastases. The latter showed throughout the study higher local gamma camera count rates as well as WBR values than the patiens with normal scintigrams. In these patients a ''flare phenomenon'', with an increase in count rate two weeks after orchiectomy followed by a decrease two months post-operatively, was seen with quantitative bone scintigraphy but not with WBC. However, WBC may be a valuable method indicating the total extent of skeletal metastases in the body, while quantitative bone scintigraphy is more accurate in the ...
Thirty-four patients with prostatic carcinoma were studied with quantitative bone scintigraphy and whole-body counting (WBC) 1 and 24 h after injection of "9"9"mTc-MDP before as well as two weeks and two months after orchiectomy. Thirteen of the patients had normal bone scintigrams and WBR at the three different investigations; 21 had skeletal metastases. The latter showed throughout the study higher local gamma camera count rates as well as WBR values than the patiens with normal scintigrams. In these patients a ''flare phenomenon'', with an increase in count rate two weeks after orchiectomy followed by a decrease two months post-operatively, was seen with quantitative bone scintigraphy but not with WBC. However, WBC may be a valuable method indicating the total extent of skeletal metastases in the body, while quantitative bone scintigraphy is more accurate in the interpretation of individual skeletal ...
Skeletal radiotracer (sup(99m)Tc-HEDP) uptake was quantitated with and without the aid of a computer in 30 chronic dialysis patients with histologic evidence of renal osteodystrophy. Before scintigraphy, elevated soft-tissue activity due to the absence of renal radiotracer excretion was reduced by hemodialysis. The results were compared with those of a normal group and with the results of the biochemical and the bone morphometric studies of these patients. In all patients the radiotracer uptake was elevated, often markedly. In several patients with minimal histologic bone disease, however, soft-tissue activity could not be normalized by hemodialysis although its influence on the quantitative data could be further reduced (but not excluded) by computer evaluation of skeletal radiotracer uptake. Since the latter technique clearly distinguished the majority of the patients from the normals, it appears that computerized quantitative skeletal ...
Skeletal radiotracer (sup(99m)Tc-HEDP) uptake was quantitated with and without the aid of a computer in 30 chronic dialysis patients with histologic evidence of renal osteodystrophy. Before scintigraphy, elevated soft-tissue activity due to the absence of renal radiotracer excretion was reduced by hemodialysis. The results were compared with those of a normal group and with the results of the biochemical and the bone morphometric studies of these patients. In all patients the radiotracer uptake was elevated, often markedly. In several patients with minimal histologic bone disease, however, soft-tissue activity could not be normalized by hemodialysis although its influence on the quantitative data could be further reduced (but not excluded) by computer evaluation of skeletal radiotracer uptake. Since the latter technique clearly distinguished the majority of the patients from the normals, it appears that computerized quantitative skeletal ...
As compared with terrestrial circuits, the communication satellite possesses superior characteristics such as wide area coverage, broadcasting, high capacity, and robustness to disasters. Utilizing the narrow band channel (64 kbps) of the geostationary satellite JCSAT 1 located at the altitude of 36,000 km above the equator, the authors investigated satellite-relayed medical imagings by video signals, with bone scintigraphy as a model. Each bone scintigraphy was taken by a handy-video camera, digitalized and transmitted from faculty of technology located at 25 kilometers apart from our department. Clear bone scintigraphy was obtained via satellite, as seen on the view box. Eight nuclear physicians evaluated 20 cases of bone scintigraphy. ROC (Receiver Operating Characteristic) analysis was performed between the scintigraphies on view box and via satellite by the rating method. The area under the ROC ...
Many otolaryngologists perform septoplasty with or without turbinate surgery and the surgical method relies largely on the surgeon's clinical judgment. This study used computed tomography (CT) of the sinuses of 20 patients to examine the correlation between a unilateral deviated nasal septum and compensatory hypertrophy of the contralateral inferior turbinate to suggest guidelines for septal and turbinate surgery. The thickness of the mucosa and conchal bone, the projection angle of the conchal bone, and the distances between the conchal bone, and lateral nasal line and median line were measured. The volume of the inferior turbinate was measured from the three-dimensional reconstruction. Each measurement was compared with those of the nasal cavity on the contralateral and of normal control subjects. The inferior turbinate on the concave side had a significantly greater volume, including the thickness of medial mucosa and ...
The uptake of sup(99m)Tc-methylenediphosphonate (MDP) in different parts of rat femur was simulated using a local three-space model for tracer transfer. The model consisted of bone blood, bone ECF-space and space for tracer deposition. The measured sup(99m)Tc-MDP concentration in the systemic blood and the local bone blood flow measured by /sup 131/I-macroaggregated albumin microspheres were used as input parameters. The measured blood flow values were 6.3, 3.1 and 15.3 ml/100 g/min for proximal, middle and distal femur, respectively. the model parameters that gave the best fit to measured sup(99m)Tc-MDP uptake curves in computer simulation showed that bone blood flow, volume of ECF-space, permeability surface area product and accretion constant from ECF-space to space for tracer deposition were highest in distal and lowest in middle femur. The values corresponded to peak extraction fractions of 0.38, ...
The uptake of sup(99m)Tc-methylenediphosphonate (MDP) in different parts of rat femur was simulated using a local three-space model for tracer transfer. The model consisted of bone blood, bone ECF-space and space for tracer deposition. The measured sup(99m)Tc-MDP concentration in the systemic blood and the local bone blood flow measured by "1"3"1I-macroaggregated albumin microspheres were used as input parameters. The measured blood flow values were 6.3, 3.1 and 15.3 ml/100 g/min for proximal, middle and distal femur, respectively. the model parameters that gave the best fit to measured sup(99m)Tc-MDP uptake curves in computer simulation showed that bone blood flow, volume of ECF-space, permeability surface area product and accretion constant from ECF-space to space for tracer deposition were highest in distal and lowest in middle femur. The values corresponded to peak extraction fractions of 0.38, ...
The effects of mouse epidermal growth factor (EGF) on bone formation and resorption were examined in male mice. EGF administration (2-200 ng.g-1.day-1 ip for 7 days) induced a dose-dependent rise in plasma EGF levels that remained within physiological range. Histomorphometric analysis of caudal vertebrae showed that EGF (20 and 200 ng.g-1.day-1) reduced the endosteal matrix and mineral appositional rates after 5 days of treatment as measured by double (3H)proline labeling and double tetracycline labeling, respectively. This effect was transitory and was not observed after 7 days of EGF administration. EGF administered for 7 days induced a dose-dependent increase in the periosteal osteoblastic and tetracycline double-labeled surfaces. At high dosage (200 ng.g-1.day-1) EGF administration increased the osteoclastic surface and the number of acid phosphatase-stained osteoclasts, although plasma calcium remained normal. The results show that EGF administration at ...
Dynamic quantitative bone scintigraphy was performed on 31 men with prostatic carcinoma before orchiectomy as well as 2 weeks, 2 and 6 months postoperatively. After injection of technetium methylene diphosphonate Tc 99m ("9"9"mTc-MDP) the count rate was recorded as serial images over the lower thoracic and all the lumbar vertebrae from 1 to 240 min post-injection. Thirteen men had normal bone scintigrams with no changes in "9"9"mTc-MDP content at the four different investigation times. Eighteen men had skeletal metastases. Throughout the study half of the abnormal vertebrae in these patients showed an abnormal count rate after only 6 min post-injection. After 1 h it was possible in almost all abnormal vertebrae to predict abnormal bone uptake. In response to therapy a 'flare phenomenon' with an increase in count rate was seen 2 weeks after orchiectomy followed by a decrease 2 months postoperatively in most of the abnormal ...
In association with excavation of the No. 135 steam producing well in the Onikubi geothermal power plant in Miyagi Prefecture, shapes of production zones and drilling-induced fracture (DIF) were acquired from the borehole televiewer (BHTV) data. The BHTV logging shoots sound waves onto well walls of wells filled with fluid and detects the reflection waves to investigate the state of the well walls. Vertical fracture with opening lengths from 2 to 3 m were found at depths of about 1232 m and 1312 m. Water run-off has occurred at a depth of about 1312 m during the excavation, to which these vertical fractures might have contributed possibly. In depths of about 1232 m and 1312 m, fractures inclining toward north-east direction and south-west direction are predominant. Some fractures in the depth of about 1333 m incline toward east-south-east direction and west-north-west direction. ...
This work covers three distinct aspects of deformation and fracture during indentations. In particular, we develop an approach to verification of nanoindentation induced film fracture in hard film/soft substrate systems; we examine the ability to perform these experiments in harsh environments; we investigate the methods by which the resulting deformation from indentation can be quantified and correlated to computational simulations, and we examine the onset of plasticity during indentation testing. First, nanoindentation was utilized to induce fracture of brittle thin oxide films on compliant substrates. During the indentation, a load is applied and the penetration depth is continuously measured. A sudden discontinuity, indicative of film fracture, was observed upon the loading portion of the load-depth curve. The mechanical properties of thermally grown oxide films on various substrates were ...
In order to achieve micro-wound, intelligence and high efficiency for fracture setting, intelligent setting system for fracture is proposed in accordance with biomechanics and fracture therapy theory. In the comprehensive medical system based on C-shape-arm X-machine, image processing and analysis is the core, programmable logical controller and stepping motor are important driving parts controlling mechanical parts. Six degree of freedom dynamics sensor ensures to control accurately force and moment. On the foundation of analyzing X-ray image peculiarities, method of processing and analysis is put forward, combining time domain with frequency domain. After mining domain knowledge in depth, setting actions is quantized into three non-continuous steps and is parameterized into two angles and one distance aiming at femoral-neck fracture. Objective features are extracted by virtue of three power ...
This paper discusses the use of tracers as a reservoir engineering tool in fractured geothermal reservoirs. The principle concern in injecting cooler spent fluids into a fractured reservoir is that the fluids may move through high permeability channels and return to the production wells after contacting a relatively small volume of rock. As a consequence of this rapid transport, the fluids will be only partially reheated and after a short period time will effectively mine the heat from the limited volume of rock. The production wells will then experience a rapid and premature reduction in thermal output. Tracers can be used to infer the existence of high mobility conduits between injection and production wells and to monitor chemical changes of an injected fluid. Since tracer arrival precedes thermal breakthrough, tracer tests are a very useful forecasting tool.
In allusion to the explosion of a urea reactor took place in a fertilizer plant at Pingyin, Shandong, China, a series of evidence collection and inspection jobs which includes collecting operation condition and parameters, sampling the explosion fracture, reactor body apart from explosion fracture, and leak detection medium and its hangover, etc., had been carried out firstly. Based on these jobs, farther analysis and computation work has been done to the structural and materials characteristics and the operation condition of the urea reactor, including compositions, metallographic phases, tensile properties, impact energy, strain ageing characteristics, and fracture toughness of the urea reactor steels, the compositions of leak detection medium and its hangover in the urea reactor, and ex...
Million-atom molecular-dynamics (MD) simulations are performed to study the structure, mechanical properties, and dynamic fracture in nanophase Si{sub 3}N{sub 4}. The authors find that intercluster regions are highly disordered: 50% of Si atoms in intercluster regions are three-fold coordinated. Elastic moduli of nanophase Si{sub 3}N{sub 4} as a function of grain size and porosity are well described by a multiphase model for heterogeneous materials. The study of fracture in the nanophase Si{sub 3}N{sub 4} reveals that the system can sustain an order-of-magnitude larger external load than crystalline Si{sub 3}N{sub 4}. This is due to branching and pinning of the crack front by nanoscale microstructures.
To represent a heterogeneous unsaturated fractured rock by its homogeneous equivalent, Monte Carlo simulations are used to obtain upscaled (effective) flow properties. In this study, we present a numerical procedure for upscaling the van Genuchten parameters of unsaturated fractured rocks by conducting Monte Carlo simulations of the unsaturated flow in a domain under gravity-dominated regime. The simulation domain can be chosen as the scale of block size in the field-scale modeling. The effective conductivity is computed from the steady-state flux at the lower boundary and plotted as a function of the averaging pressure head or saturation over the domain. The scatter plot is then fitted using van Genuchten model and three parameters, i.e., the saturated conductivity K{sub s}, the air-entry parameter {alpha}, the pore-size distribution parameter n, corresponding to this model are considered as the effective K{sub s}, effective {alpha}, and ...
The electrochemical behaviour and fracture morphology of homogenized and sensitized type SAE 304 stainless steel U bent specimens, in 3% NaCl solution, at pH=2.0 and pH=7.0 both at room temperature and 100"0C was studied. Polarization curves, galvanostatic and potentiostatic experiments were run. It could be observed that high temperature and low pH favour transgranular cracking and longer sensitization times lower fracture time and tend to give rise to intergranular fracture. Light sensitization can produce transgranular cracking even at room temperature, when the homogenized alloy does not present stress-corrosion cracking for the same condition. (Author).
Dense samples of #beta#-sialons (with z from 1 to 4) were pressuressly sintered for different time (15-240 minutes) and at relatively low temperature of 1600 C using single-phase #beta#-sialon powders synthesized by combustion nitridation. The samples were characterized using ultrasonic method for determination of elastic properties (E,G,#mu#). Also, hardness by Knoop and fracture toughness by Vickers indentation microfracture method was estimated. With increasing z number Young's modulus decreases from 293 to 179 GPa. Simultaneously Poisson ratio increases by about 30%. The highest values of hardness and fracture toughness were obtained for sialon with z equal to 1. (orig.).
In the paper results of the investigation on the effect of microstructure on room temperature tensile properties and fracture toughness of two-phase #alpha#+#beta# titanium alloy Ti-6Al-2Mo-2Cr have been presented. Microstructure has been varied by changes in the cooling rate from the solution treatment temperature and aging time and temperature. Mechanical properties examined show dependence on the treatment conditions, especially aging conditions. It has been attributed mainly to the amount and morphology of #alpha# phase obtained after heat treatment. The higher volume fraction of lamellar #alpha# structure, the higher fracture toughness. (author)
The surveillance systems have been widely used in automatic teller machines (ATMs), banks, convenient stores, etc. For example, when a customer uses the ATM, the surveillance systems will record his/her face information. The information will help us understand and trace who withdrew money. However, when criminals use the ATM to withdraw illegal money, they usually block their faces with something (in Taiwan, criminals usually use safety helmets or masks to block their faces). That will degrade the purpose of the surveillance system. In previous work, we already proposed a technology for safety helmet detection. In this paper, we propose a mask detection technology based upon automatic face recognition methods. We use the Gabor filters to generate facial features and utilize geometric analysis algorithms for mask detection. The technology can give an early warning to save-guards when any "customer" or "intruder" blocks his/her face information with a mask. Besides, ...
In this study, we propose a new bioactive bone cement (BBC), composed of natural bone powder (hydroxyapatite; HA), chitosan powder, and the currently available polymethylmethacrylate (PMMA) bone cement, for use in orthopedic surgeries such as vertebroplasty or as bone filler. Three types of BBCs (BBC I, BBC II, and BBC III) were prepared with different composition ratios. In vitro tests and animal studies were performed with the new BBCs, and with a currently available commercial PMMA bone cement. Surface morphology, chemical composition, changes in pH over time, exothermic temperatures, intrusion, and cellular responses were investigated in vitro. Scanning electron microscopy (SEM) and radiological and histological examinations were performed in animal studies. The results showed that the major components of the BBCs were C, O, Ca, P, Cl, Si, S, Ba, and Mg. The pH values of the ...
Quantitative bone scintigraphy was performed in patients with prostatic carcinoma before orchiectomy as well as two weeks, two and six months after operation. The count rate was recorded as serial gamma camera images over the lower thoracic and all lumbar vertebrae from 1 to 240 min and at 24 h after injection of "9"9"Tc"m-MDP. In almost all abnormal vertebrae an increased count rate was observed within one hour after injection. Most of the vertebrae which were considered normal at 4 h after injection, but had an increased 24h/4h ratio developed into abnormal vertebrae later in the study. The patients with normal bone scintigrams showed no change in "9"9Tc"m-MDP uptake during the study. The reproducibility of quantitative bone scintigraphy was found to be #+-# 7% (1 SD). In response to therapy, most of the patients with abnormal bone scintigrams showed an increase in count rate two weeks after operation ...
Urinary acidification, bone metabolism and urinary excretion of calcium and citrate were evaluated in 10 recurrent stone formers with incomplete renal tubular acidosis (iRTA), 10 recurrent stone formers with normal urinary acidification (NUA) and 10 normal controls (NC). Patients with iRTA had lower plasma standard bicarbonate after fasting (P <0.01) and lower urinary excretion of titratable acid (P <0.05) and citrate (P <0.01) compared with NUA patients and NC, and higher urinary excretion of ammonia (P <0.05) compared with NC (P <0.05). Hypercalciuria was found in 6 of 10 patients with iRTA compared with 3 of 10 with NUA, and 0 of 10 NC. The citrate/calcium ratio in urine was significantly reduced in iRTA compared with the value in NUA (P <0.01), and in NUA compared with NC (P <0.05). Biochemical markers of bone formation (serum osteocalcin) and bone resorption (urinary hydroxyproline) were ...
Patients with Ewing's sarcoma who present with a central axis or proximal extremity primary and/or with metastatic disease have a poor prognosis despite aggressive combination chemotherapy and local irradiation. In this high risk group of patients, total body irradiation (TBI) has been proposed as a systemic adjuvant. To aid in the design of a clinical TBI protocol, the authors have studied in the in vitro radiation response of two established cell lines of Ewing's sarcoma and human bone marrow CFUc. The Ewing's lines showed a larger D_0 and anti-n compared to the bone marrow CFU. No repair of potentially lethal radiation damage (PLDR) was found after 4.5 Gy in plateau phase Ewing's sarcoma cells. A theoretical split dose survival curve for both the Ewing's sarcoma lines and human bone marrow CFUc using this TBI schedule shows a significantly lower surviving fraction (10"-"4-10"-"5) for the bone marrow ...
To determine the effects of ammonium chloride (NH4Cl) dosage and swimming exercise training during 4 weeks on bone metabolic turnover in rats, seven-week-old female 24 Wister-Kyoto (WKY) rats were investigated by bone status including bone mineral density (BMD) and biomechanical markers from blood and urine. Twenty-four rats (initial weight: 191.2+/-7.6 g) were randomly divided into four groups: baseline (8 weeks old) control group (n=6, BC), 4-week control group (n=6, Con), 4-week swimming exercise loading group (n=6, Swim) and 4-week chronic NH4Cl dosage group (n=6, Acid). All rats were fed an AIN93M diet (Ca: 0.5%, P: 0.3%), and both Con and Swim groups were pair-fed by feeding volume of the NH4Cl dosage group. The acid group only received 0.25 M NH4Cl distilled water ad libitum. At the end of the experimental period, rats were sacrificed with blood drawn and femur and tibia were removed for analysis of ...
Background. In multiple myeloma 5 different infiltration patterns can be differentiated: 1. Normal appearance of bone marrow, 2. focal involvement, 3. homogeneous diffuse infiltration, 4. combined diffuse and focal infiltration, 5. 'salt-and pepper' pattern with inhomogeneous bone marrow with interposition of fat islands. Methods. For the fast and total acquisition of all patterns a combination of a T1-weighted spin echo sequence and a fat suppression technique is superior. The focal involvement is clearly demonstrated as areas of high signal intensity on e.g. STIR images. Diffuse involvement can be quantified objectively by calculation of the percentage of signal intensity increase after contrast material injection. MRI is superior to X-ray in focal and diffuse involvement. With ultrafast sequences a 'screening' of the whole red bone marrow as for myeloma infiltration is possible. Prognosis. In prognosis studies diffuse ...
A prospective, side-by-side comparison study of two different lasers for the treatment of solar- induced telangiectasia was carried out in 14 patients at the Beckman Laser Institute and Medical Clinic. The argon tunable dye laser (Coherent, Palo Alto, Calif.) was used in the method modified from Orenstein and Nelson to completely treat discrete telangiectasias on one cheek. Specifically, the argon tunable dye laser (ATDL) was set at 0.7 - 0.8 watts, 585 nm wavelength, shutter-pulsed at 0.1 second duration with a spot size of 0.1 mm, and individual vessels were 'traced out' with 4X loupe magnification. Each patient's opposite cheek was then treated in the standard fashion with the flashlamp pulsed dye laser (Candela, Natick, Mass.) using a technique similar to Polla's et al. Specifically, the flashlamp pulsed dye laser (FPDL) was set at 585 nm wavelength, pulsed mode of 450 microseconds pulse duration, spot size of 5 mm, overlapping 10 - 20%, with power densities of 5.5 to 6.5 ...
Purpose: To evaluate a simple method for quantification of focal activity in bone scintigraphy (BS). Material and methods: The gamma camera was calibrated using a phantom. Quantitative bone scintigraphy (QBS) was performed on 11 men recently diagnosed with prostate cancer (PCa), for whom routine BS showed involvement of the skeleton. Following endocrine therapy for 4 to 8 months, a second QBS was performed. Changes in QBS values were then compared to changes in serum levels of prostate-specific antigen (PSA). Results: PSA response indicating regression of PCa was accompanied by a decrease in the QBS value in 8 of the 11 patients. The overall mean error of the QBS values was 15%. conclusion: QBS according to this method is a relatively simple procedure that might contribute to objective evaluation of therapeutic effects in skeletal metastases, although its validity must be tested in a larger clinical material.
Purpose: To evaluate a simple method for quantification of focal activity in bone scintigraphy (BS). Material and methods: The gamma camera was calibrated using a phantom. Quantitative bone scintigraphy (QBS) was performed on 11 men recently diagnosed with prostate cancer (PCa), for whom routine BS showed involvement of the skeleton. Following endocrine therapy for 4 to 8 months, a second QBS was performed. Changes in QBS values were then compared to changes in serum levels of prostate-specific antigen (PSA). Results: PSA response indicating regression of PCa was accompanied by a decrease in the QBS value in 8 of the 11 patients. The overall mean error of the QBS values was 15%. conclusion: QBS according to this method is a relatively simple procedure that might contribute to objective evaluation of therapeutic effects in skeletal metastases, although its validity must be tested in a larger clinical material
A Quantitative Computed Tomography (QCT) method, simplifying the well-known technique proposed by Genant (1982) and applied to a standard third generation whole body CT scanner is described. This technique was applied in the measurement of the trabecular bone which has high sensitivity for metabolic changes. The BMC (Bone Mineral Content) measured in different groups of subjects (healthy postmenopausal patients versus women with postmenopausal osteoporosis) showed a highly significant difference (p<0.001). The precision of repositioning (coefficient of variation 1.8% to 2.3%, obtained in healty male patients) and the good, linear relationship computed from the phantom values, minimize measurement errors. Since this method is quickly applied and involves low-dose radiation-exposure, it could be introduced in the clinical study of metabolic bone diseases.
As to all sinter variations the microradiographic analysis showed that about 86 to 90 % of the implant surface were enclosed split-free with newly formed bone 16 weeks post operationem. A silicat salt addition of the test variation Ap_4_0KS_1_5 and Ap_4_0KS_3_0 did not cause a negative influence on bone regeneration. On the surface of all test implants a double layer was revealed radiologically, consisting of a 30 - 40 #mu#m thick bone near X-ray impermeable area and an X-ray permeable area of maximum 120 #mu#m thickness directed to the nucleus of the implant.
As to all sinter variations the microradiographic analysis showed that about 86 to 90 % of the implant surface were enclosed split-free with newly formed bone 16 weeks post operation. A silicate salt addition of the test variation Ap/sub 40/KS/sub 15/ and Ap/sub 40/KS/sub 30/ did not cause a negative influence on bone regeneration. On the surface of all test implants a double layer was revealed radiologically, consisting of a 30 - 40 ..mu..m thick bone near X-ray impermeable area and an X-ray permeable area of maximum 120 ..mu..m thickness directed to the nucleus of the implant.
The half-value thicknesses, linear and mass attenuation coefficients of biological samples such as bone, muscle, fat and water have been measured at 140, 364 and 662keV ?-ray energies by using the ATOMLABTM-930 medical spectrometer. The ?-rays were obtained from 99mTc, 131I and 137Cs ?-ray point sources. Also theoretical calculations have been performed in order to obtain the half-value thicknesses and, mass and linear attenuation coefficients at photon energies 0.001keV-20MeV for bone, muscle and water samples. The calculated value and the experimental results of this work and the other results in literature are found to be in good agreement.
Between 1964 and 1977, 94 patients with Ewing's sarcoma of bone were treated at the National Cancer Institute. They received 5000 rad to the whole bone and progressively more aggressive chemotherapy protocols. The patients were divided according to site of primary lesion into central, proximal and distal lesions, with 19%, 33% and 57%, respectively, alive and well. The local control rate is high (93%), with good functional results in the distal lesions, and no changes are needed in radiation therapy dose or volume. Control is not as satisfactory for central and proximal lesions and efforts need to be made to increase control at these sites. We are at present attempting to define more accurately the extent of soft tissue disease, increasing the dose to 6000 rad for central lesions, and using a more aggressive chemotherapy program, in the hope of increasing the local control in these more aggressive tumors.
The treatment of acetabular bone defects presents a great challenge in revision total hip arthroplasty (THA). The purpose of this study was to evaluate the clinical and radiological outcome of revision THA using jumbo cups for acetabular reconstruction after applying the bone-grafting technique. We studied 17?patients with acetabular defects ranging from Type 2A to Type 3A according to Paprosky`s classification. According to the AAOS-score twelve patients were classified as Type II and five patients as Type III. Uncemented press-fit cups with an outer diameter larger than 64?mm were used in all cases. Fifteen patients received morselized bone allografts. In eight patients an additional screw fixation was necessary. The mean follow-up period was 82?months (range 33?149). The mean Harris Hip...
Ionizing radiation has been used to treat poultry to remove harmful microorganisms, mainly Salmonella, which contaminates chicken, goose and other fresh and frozen poultry. This microorganism is sensitive to low dose radiation. Thus, irradiating these foods with doses between 1 to 7 kGy results in a large reduction of bacteria. Since it is necessary to determine whether irradiation has occurred and to what extend, this work studied the signal produced by ionizing radiation within the hard crystalline matrix of chicken`s bone to establish a control method. Chicken`s drumsticks were irradiated and bones separated from flesh were lyophilized and milled. ESR spectrum was then obtained. The ESR signal increased linearly with dose over the range 0.25 to 8.0 kGy. Free radicals evaluated during 30 days after irradiation showed stable in this period. (Author).
Background:The manufacturers of oral bisphosphonates (alendronate, risedronate) recommend avoiding use of these drugs in patients with renal impairment. However, many patients who...Full Text Available
Secondary caries and restoration fracture remain the two most common problems in restorative dentistry. Release of fluoride ions (F) could be a substantial benefit because F could enrich neighboring...Full Text Available
PurposeSatisfaction of search (SOS) occurs when an abnormality is missed because another abnormality has been detected. This research studied whether the severity...Full Text Available
To maintain operational readiness, military personnel engage in vigorous physical and training activities that carry risk for injury. A 1-year prospective cohort study, starting April 1996, was conducted at Fort Bragg, North Carolina among 1,965 members of the 82nd Airborne Division to quantify musculoskeletal injuries. Information collected included type of injury, site, circumstances, and resultant limited duty days. These soldiers suffered 508 overuse injuries (including 38 stress fractures), 1,415 traumatic injuries (including 100 fractures), and 101 unclassified injuries. Injury rates were 6.8% per soldier per month for traumatic injury and 2.4% for overuse injury (totaling 1.2 injuries per soldier per year). Injuries resulted in 22,041 limited duty days, averaging 11 days per injury and 13 days per soldier (4.5% of total workdays). Fractures and stress fractures/reactions produced the most days ...
It is well known that composite armors, consisting of glass elements confined with metallic tampers, are extraordinarily effective against shaped charge attack. Early experiments showed that jets fired against glass targets appeared to be bombarded by tiny fragments that destroyed alignment and reduced residual jet penetration. This result was attributed to an elastic rebound effect in which the outward radial motion of the target around the jet periphery was supposed to be arrested by tensile hoop stresses which developed behind the divergent shock front. Glass fragments were then accelerated radially inward and these destabilized the jet. To sustain the large tensile hoop stresses required, the glass must not have been fractured by the initial shock, behind which the stress state is typically well above the Hugoniot elastic limit. Modeling the penetration of a jet into glass requires not only determining the spall strength, i.e., the tensile stress at which ...
The papers contained in this volume provide an overview of recent theoretical and experimental research related to the fracture toughness and fatigue crack growth characteristics of titanium alloys. Topics discussed include room temperature fatigue crack propagation in beta-titanium alloys, fatigue crack growth rate acceleration in alpha+beta Ti alloys, influence of transformed beta microstructures on fatigue crack growth rates in Ti-6Al-4V, and the role of inclusion and pore content on the fracture toughness of powder processed blended elemental Ti-10V-2Fe-3Al. Papers are also presented on fatigue crack growth measurements in an alpha-beta titanium alloy, the effects of thermal processing variation on the properties of Ti-6Al-4V, and the effect of microstructure on ductility and fracture toughness of alpha+beta titanium alloys.
All ceramic fixed partial dentures (FPD)s exhibit enhanced biocompatibility and esthetics as compared to metal-ceramic restorations. However, framework fractures are frequently reported especially when...Full Text Available
With regard to a fracture system in the Hijiori hot dry rock artificial reservoir, an attempt was made on an interpretation which integrates different data. Major factors that characterize development and performance of an artificial reservoir are composed of a fracture system in rocks, which acts as circulating water paths, a heat exchange face and a reservoir space. The system relates not only with crack density distribution, but also with cracks activated by water pressure fracturing, cracks generating acoustic emission (AE), and cracks working as major flow paths, all of which are characterized by having respective behaviors and roles. Characteristics are shown on AE cluster distribution, crack distribution, production zone and estimated stress fields. Mutual relationship among these elements was discussed based on the Coulomb`s theory. The most important paths are characterized by distribution of slippery cracks. ...
Dynamic fracture toughness tests were performed on materials which had been subjected to one of three long-time post weld type stress relief heat treatments: 48 hours at 1000/degree/F (538/degree/C), 24 hours at 1125/degree/F (607/degree/C), and 48 hours at 1125/degree/F (607/degree/C). Linear elastic K/sub Id/ results were obtained at low temperatures while J-integral techniques were utilized to evaluate dynamic fracture toughness over the transition and upper shelf temperature ranges. Tensile, Charpy impact, and drop weight nil-ductility transition tests as well as room temperature, air environment fatigue crack growth rate tests (SA508 Cl 2a only) were also performed. The fracture toughness of both materials exceeded the ASME specified minimum reference toughness K/sub IR/ curve. 17 refs.
Dynamic fracture toughness tests were performed on materials which had been subjected to one of three long-time post weld type stress relief heat treatments: 48 hours at 1000/degree/F (538/degree/C), 24 hours at 1125/degree/F (607/degree/C), and 48 hours at 1125/degree/F (607/degree/C). Linear elastic K/sub Id/ results were obtained at low temperatures while J-integral techniques were utilized to evaluate dynamic fracture toughness over the transition and upper shelf temperature ranges. Tensile, Charpy impact, and drop weight nil-ductility transition tests as well as room temperature, air environment fatigue crack growth rate tests (SA508 Cl 2a only) were also performed. The fracture toughness of both materials exceeded the ASME specified minimum reference toughness K/sub IR/ curve. 17 refs.
Purpose:The risks and benefits of continuing bisphosphonate therapy beyond 5 years in patients with primary osteoporosis have not been well established.Methods:We...Full Text Available
Analyses of the date obtained from the instrumented impact test and of its correlation with static and dynamic J integral values and various tensile properties are made in this study. It is shown that a dynamic bending yield load recorded in the instrumented Charpy V test can be easily converted to a dynamic tensile yield stress using Server's equation. It is also possible to estimate a true fracture strain, COD value, and SZW easily if the load point displacement is recorded. Temperature dependency of Charpy V energy and J integral values is rather well simulated by a curve fitting method. However, a half value transition temperture obtained in that method has no physical meaning. Dynamic J sub(ID) is larger than a static J sub(IC) in the ductile fracture range in this study. This rise is proportional to the yield stress ratio sigmasub(yd)/sigmasub(y)(--1.2-1.3). It is found, therefore, that the following relation exists in the both ...
Analyses of the date obtained from the instrumented impact test and of its correlation with static and dynamic J integral values and various tensile properties are made in this study. It is shown that a dynamic bending yield load recorded in the instrumented Charpy V test can be easily converted to a dynamic tensile yield stress using Server's equation. It is also possible to estimate a true fracture strain, COD value, and SZW easily if the load point displacement is recorded. Temperature dependency of Charpy V energy and J integral values is rather well simulated by a curve fitting method. However, a half value transition temperture obtained in that method has no physical meaning. Dynamic J sub(ID) is larger than a static J sub(IC) in the ductile fracture range in this study. This rise is proportional to the yield stress ratio #sigma#sub(yd)/#sigma#sub(y)(--1.2-1.3). It is found, therefore, that the following relation exists in the both cases; ...
Past elastic-plastic fracture studies for leak-before-break (LBB) assessment of low alloy steel pipings have been focused mostly on the behavior of base metals and their weld metals. In contrast, the heat-affected zone (HAZ) of a welded pipe has not been studied in detail primarily because the size of the HAZ is too small to make specimens for mechanical properties measurements. In this study, microstructural analyses, microhardness tests, tensile tests and J-R tests have been conducted as a function of distance from a fusion line and temperature for HAZ materials of SA106Gr.C low alloy piping steels. For the ferrite-pearlite steels such as SA106Gr.C, the HAZ specimens showed a higher yield strength and fracture toughness compared with those of its base metal. These characteristics, despite of grain coarsening, can be explained by cleaner microstructures of HAZ materials with a finer morphology of carbides compared with pearlitic-ferritic base ...
Lumbar epidural anesthesia is useful in a variety of chronic benign pain syndromes, including lumbar radiculopathy, low back pain syndrome, spinal stenosis, and vertebral compression fractures. Given...Full Text Available
Non-cemented femoral fixation in hip arthroplasty has become the standard of practice in the USA. However, recent literature has brought attention to an increasing incidence of periprosthetic femur...Full Text Available
An 82-year-old female, with left femoral neck fracture was scheduled for left hip hemiarthroplasty, under spinal anaesthesia. She had been suffering from diabetes, hypertension, lung cancer and was...Full Text Available
SiAlONs are ceramics with high potential as biomaterials due to their chemical stability, associated with suitable mechanical properties, such as high fracture toughness and fracture resistance. The objective of this work was to investigate the mechanical properties and the cytotoxicity of these ceramic materials. Three different compositions were prepared, using silicon nitride, aluminum nitride and a rare earth oxide mixture as starting powders, yielding Si_3N_4-SiAlON composites or pure SiAlON ceramics, after hot-pressing at 1750 deg. C, for 30 min. The sintered samples were characterized by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). Furthermore, hardness and fracture toughness were determined using the Vicker's indentation method. The biological compatibility was evaluated by in vitro cytotoxicity tests. Ceramic with elevated hardness, ranging between 17 and 21 GPa, and high ...
Premature removal of the fixator after a lengthening procedure can result in gradual bending or acute fracture of the regenerate. We reviewed the records of 26 patients who underwent 28 limb lengthenings...Full Text Available
This biographical sketch on John R. Moore corresponds to the historic text, The Classic: Cartilaginous-cup Arthroplasty in Ununited Fractures of the Neck of the Femur (1948), available at DOI External Reference Not Shown .
Major factors that contribute to maximized impact resistance of semicrystalline engineering polymers include increased matrix molecular weight, minimal rubber glass-transition temperature, and optimal rubber-particle size, which depends on matrix type. Additional constraints are posed by the limitations of available materials and commercial requirements. Expanding the understanding of impact-modified crystalline engineering polymers will further extend their property ranges and utility. This chapter describes the phenomenology of certain factors, illustrates a new technique to measure rubber particle size, and contrasts the fracture mechanisms of poly(butylene terephthalate), nylon 66, and polyacetal. 49 refs., 24 figs.
Simplified strain-based fracture mechanics equations, established for external surface cracked pipelines subjected to an external bending load, are presented and used in probabilistic assessment of a pipeline girth weld. The model takes into account several parameters, such as variation in crack depth, crack length, internal pressure and material hardening. The critical strain from ductile tearing in the cracked pipeline is found by using the tangency criterion. The reliability problem is solved using first and second order reliability methods for different pipe dimensions and load levels.
Measurements of the humeral cortical thickness demonstrate that generalised osteoporosis in female Bantu commences in the fifth decade and gradually increases until, in the ninth decade, all subjects are osteoporotic. The combined cortical thickness (CCT) of the humerus in young adults is very similar to that found previously in a white London population and the loss of cortex with age is very similar. It is concluded that the known low incidence of femoral neck fracture in Bantu is not due to a lower incidence of generalised osteoporosis but to environmental factors. The chief environmental factor postulated is the greater amount of physical work performed by the Bantu. A more careful mode of walking is suggested as a subsidiary cause. (orig.).
The crack growth behavior and fracture toughness of two laminated metal composites (6090/SiC/25p laminated with 5182 and ultrahigh-carbon steel laminated with brass) have been studied in both ``crack arrester`` and ``crack divider`` orientations. The mechanisms of crack growth were analyzed and extrinsic toughening mechanisms were found to contribute significantly to the toughness. The influence of laminate architecture (layer thickness and component volume function), component material properties and residual stress on these mechanisms and the resulting crack growth resistance are discussed.
We present the case of a 12-year-old girl who presented with a pathological fracture through a benign-appearing osteolytic lesion that was presumed to represent fibrous dysplasia. The fracture healed, and over the next 2.5 years there was further refracturing and healing with progressive osteolysis. A biopsy was performed and revealed Ewing's sarcoma. The disease was locally controlled by neoadjuvant chemotherapy and radiation therapy. The patient is disease free with excellent function 6 years following the discovery of the lesion. We illustrate and discuss the sequence of events. (orig.)
The report summarizes ten years of experience in the analysis and evaluation of ultrasonic testing data measured in turbine and generator rotors. Apart from the information on type, position, size and distribution of flaws, the expert knowledge achieved in an interpretation of ultrasonic signals yields further insight, as e.g.: - Confirmation of assumptions taken as a basis for fracture-mechanical analysis of these flaws with regard to crack initiation and crack growth under low-cycle fatigue conditions (O=0.7-1 Rp 0.2, N<25.000 growth in length); - enhanced information on a correlation of ultrasonic testing data with the real flaw size. (orig.).
The effect of the rare earth element, yttrium, on the mechanical properties of 9Cr-2WVTa low active martensite steel for fusion reactor was studied and the metallurgical behavior of yttrium in the steel was primarily analyzed. The results show that it is easy for yttrium to aggregate and form the blocky yttrium rich inclusions in the steel, which can dissever the continuity of the matrix and produce micro-cracks for fracture. The yttrium rich inclusions were distributed along the rolling direction, which made the fracture surface delaminated in the tensile and impact samples, and reduced the mechanical properties of the steel. (authors)
It is known that in size reduction of the granular structure of ferrite and ferrite-pearlite steels the temperature of the transformation from ductile to brittle condition is lowered. This effect can also be caused by an increase in the dispersity of intragrain and intergrain segregations (sulfides, carbonitrides, and segregations of impurity atoms), which accompanies grain size reduction and promotes initiation and propagation of cracks. In order to clarify the mechanism of fracture of steel in the region of the ductile-brittle transition steel 45 with different grain sizes and pearlite morphologies has been investigated.
The report traces the documented incidences of brittle fracture in composite suspension insulators for use on high voltage transmission lines, and presents the subsequent investigations. It describes the part played by electrical activity, stress corrosion and humidity, and compares similar failures that have taken place in electric traction insulators. It then goes on to review related work on the humidity effects, stress corrosion, fatigue and partial discharges in glass fiber reinforced plastics in general. The final section summarizes the present understanding of the problem and the various measures taken by different manufactures to avoid it in the future. The need for acceptance criteria in this respect is outlined.
Authors obtained T1-weighted MRI images of the femoral head after fracture of the femoral neck and classified the signals into four patterns to investigate the sequential changes of the femoral head. The T1-weighted MRI images obtained initially after femoral neck fracture showed a normal pattern in 10 of the 15 hip joints studied. MRI images obtained subsequently still showed the normal signal pattern in eight of the 10 hip joints which had shown the normal pattern in the first MRI, while two of the 10 joints subsequently showed a band pattern. The joint with the homogeneous pattern in the first MRI subsequently showed a band pattern. Of the three joints with an inhomogeneous pattern in the first MRI, two joints showed a subsequent band pattern, and the other a normal pattern. The joints which showed a band pattern continued to show a similar band pattern. Eventually, all hip joints studied showed a normal or band pattern within six months ...
As part of studies into the siting of a deep repository for nuclear waste, Swedish Nuclear Fuel and Waste Management Company (SKB) has commissioned the Alternative Models Project (AMP). The AMP is a comparison of three alternative modeling approaches for geosphere performance assessment for a single hypothetical site. The hypothetical site, arbitrarily named Aberg is based on parameters from the Aespoe Hard Rock Laboratory in southern Sweden. The Aberg model domain, boundary conditions and canister locations are defined as a common reference case to facilitate comparisons between approaches. This report presents the results of a discrete fracture pathways analysis of the Aberg site, within the context of the SR 97 performance assessment exercise. The Aberg discrete fracture network (DFN) site model is based on consensus Aberg parameters related to the Aespoe HRL site. Discrete fracture pathways are identified from canister ...
Several tight, naturally-fractured, gas-productive formations in the Greater Green River Basin (GGRB) in Wyoming have been exploited using conventional vertical well technology. Typically, hydraulic fracture treatments must be performed in completing these wells to increase gas production rates to economic levels. However, with the maturation of horizontal drilling technology hydraulic fracture treatments may not be the most effective method for improving gas production from these tight reservoirs. Two of the most prolific tight gas reservoirs in the Green River Basin, the Frontier and the Mesaverde, are candidates for the application of horizontal well completion technology. The objective of the proposed project is to apply the DOE`s technical concept to the Second Frontier Formation on the western flank of the Rock Springs Uplift. Previous industry attempts to produce in commercial quantities from the Second Frontier ...
In light water reactors, austenitic stainless steels (SSs) are used extensively as structural alloys in reactor core internal components because of their high strength, ductility, and fracture toughness. However, exposure to high levels of neutron irradiation for extended periods degrades the fracture properties of these steels by changing the material microstructure (e.g., radiation hardening) and microchemistry (e.g., radiation-induced segregation). Experimental data are presented on the fracture toughness and crack growth rates (CGRs) of wrought and cast austenitic SSs, including weld heat-affected-zone materials, that were irradiated to fluence levels as high as {approx} 2x 10{sup 21} n/cm{sup 2} (E > 1 MeV) ({approx} 3 dpa) in a light water reactor at 288-300 C. The results are compared with the data available in the literature. The effects of material composition, irradiation dose, and water chemistry on CGRs ...
(1) To determine the accuracy of computed tomography (CT) in the evaluation of ligament tear and avulsion in patients with tibial plateau fracture. (2) To evaluate whether the presence or severity of fracture gap and articular depression can predict meniscal injury. A fellowship-trained musculoskeletal radiologist retrospectively reviewed knee CT and MRI examinations of 41 consecutive patients presenting to a level 1 trauma center with tibial plateau fractures. Fracture gap, articular depression, ligament tear and footprint avulsions were assessed on CT examinations. The MRI studies were examined for osseous and soft tissue injuries, including meniscal tear, meniscal displacement, ligament tear, and ligament avulsion. CT demonstrated torn ligaments with 80% sensitivity and 98% specificity. Only 2% of ligaments deemed intact on careful CT evaluation had partial or complete tears on MRI. Although the ...
PurposeDutasteride and finasteride are 5α-reductase inhibitors that dramatically decrease serum levels of dihydrotestosterone. Because androgens...Full Text Available
We studied telomeric DNA in leukemic cells as well as in normal T cells, B cells, monocytes, polymorphonuclear leukocytes, and bone marrow hematopoietic progenitor cells. No marked differences were...Full Text Available
The effect of reinforcement in the cross-linked poly(propylene fumarate-co-caprolactone diol) thermoset composites based on Kevlar fibres and hydroxyapatite was studied. Cross-linked poly(propylene...Full Text Available
The main objectives of this study was to determine the bone density for the purposes of i) determining the age of peak bone mass in each study group and ii) quantifying the differences in bone density as functions of age and sex. The results of estimating the age dependence of mineral density for the femoral neck, spine and total body of healthy women and men using DEXA are given. The age changes in concentrations of major minerals and electrolytes found for compact and trabecular bones of healthy male femoral neck with regard for the wet and dry tissue calculations are represented. Information about femoral neck water content depending on the age of healthy men is tabulated. The number of performed observations and analyses is evidently insufficient to make any final decision, however some preliminary conclusions can be drawn. In accordance with DEXA results, BMD maximum for the femoral neck, spine and ...
BackgroundDistraction osteogenesis is the standard treatment for the management of lower limb length discrepancy of more than 3 cm and bone loss secondary to congenital anomalies,...Full Text Available
BackgroundEwing sarcoma (ES) is the second most common bone tumor in children, and survival of those with metastatic ES has not improved. Previous studies have shown...Full Text Available
Bone scintigraphy was performed in 16 men with newly diagnosed prostatic carcinoma before orchiectomy as well as 2 weeks and 2 months after operation. The uptake in the lower thoracic and lumbar vertebrae was registered up to 240 min after injection of /sup 99m/Tc-MDP and was then calculated for each patient and vertebra. The relative standard deviation in measured uptake due to measuring technique was estimated to be +-7%. In eight patients, who had normal bone scintigraphies before orchiectomy, there were no changes in the uptake values after operation. The remaining eight patients had widespread metastatic involvement prior to treatment, six of these patients showed a so-called 'flare phenomenon' in the abnormal vertebrae which means an initial increase in uptake after operation followed by a decreased uptake in response to therapy. One patient had a continuously increased uptake in all the abnormal vertebrae which ...
Bone scintigraphy was performed in 16 men with newly diagnosed prostatic carcinoma before orchiectomy as well as 2 weeks and 2 months after operation. The uptake in the lower thoracic and lumbar vertebrae was registered up to 240 min after injection of "9"9"mTc-MDP and was then calculated for each patient and vertebra. The relative standard deviation in measured uptake due to measuring technique was estimated to be #+-#7%. In eight patients, who had normal bone scintigraphies before orchiectomy, there were no changes in the uptake values after operation. The remaining eight patients had widespread metastatic involvement prior to treatment, six of these patients showed a so-called 'flare phenomenon' in the abnormal vertebrae which means an initial increase in uptake after operation followed by a decreased uptake in response to therapy. One patient had a continuously increased uptake in all the abnormal vertebrae which correlated well with the ...
Quantitative bone scintigraphy was performed in 24 patients with prostatic carcinoma before orchiectomy and up to one to four years after operation. The gamma camera count rate was recorded over the lower thoracic and all lumbar vertebrae 4 h after injection of [sup 99m]Tc-MDP. Twelve patients has normal bone scintigrams throughout the study. They showed from two years after operation a slight increase in count rate values compared with the preoperative values, probability due to hormonal changes after orchiectomy and to age-related alterations in skeletal metabolism. Twelve patients had abnormal bone scintigrams. They showed as a response to treatment the flare phenomenon with an increase in count rate over the abnormal vertebrae when measured two weeks after operation followed by a decrease after two months. The lowest count rate values were obtained between six months and one year after operation. Thereafter the count ...
Quantitative bone scintigraphy was performed in 24 patients with prostatic carcinoma before orchiectomy and up to one to four years after operation. The gamma camera count rate was recorded over the lower thoracic and all lumbar vertebrae 4 h after injection of "9"9"mTc-MDP. Twelve patients has normal bone scintigrams throughout the study. They showed from two years after operation a slight increase in count rate values compared with the preoperative values, probability due to hormonal changes after orchiectomy and to age-related alterations in skeletal metabolism. Twelve patients had abnormal bone scintigrams. They showed as a response to treatment the flare phenomenon with an increase in count rate over the abnormal vertebrae when measured two weeks after operation followed by a decrease after two months. The lowest count rate values were obtained between six months and one year after operation. Thereafter the count rate ...
French ... Orig. Title Scintigraphie osseuse quantifiee chez l'enfant et l'adolescent - repartition selon l'age des taux de fixation de diverses pieces osseuses normales.
The parathyroid hormone receptor (PTHR) is a class B G protein-coupled receptor that plays critical roles in bone and mineral ion metabolism. Ligand binding to the PTHR involves interactions to both...Full Text Available
In this study, we report the physico-chemical and biological properties of a novel biodegradable composite scaffold made of nano-hydroxyapatite and natural derived polymers of chitosan and carboxymethyl...Full Text Available
For diagnosis of loosening or infection after implantation of a single-side or double-side total hip endoprosthesis 59 patients being in pain were investigated by a combination of bone scan (Technetium-99m DPD) and leucocyte scan (Indium-111 labelled leucocytes). The correlation between clinical results and scintigraphic findings revealed: bone scintigraphy detects loosening of prostheses with 95% sensitivity (45/47); bone scintigraphy excludes an instable prosthesis with 89% specificity (3/27). 45% of the loosened prostheses revealed an infection (21/47): leucocyte scintigraphy could detect 17 correct positive. Three leucocyte scans of 53 prostheses without clinical signs of infection were false positive. Therefore, leucocyte scintigraphy had a sensitivity of 91% and a specificity of 94% for detecting infection. Bone scintigraphy can detect loosening of prostheses with 93% accuracy, Indium-111 labelled ...
Successful implementation of bone marrow transplantation for hematopoietic reconstitution is limited by the lack of suitably HLA-matched donors and by the occurrence of graft-versus-host disease that...Full Text Available
Osteoid osteoma of the spine is a relatively rare bone-forming tumor. Pain that is worse at night and relieved by aspirin and muscle contracture are the most characteristic symptoms of spinal osteoid...Full Text Available
IntroductionPrimary tumors of the breast containing bone and cartilage are extremely rare, and an osteogenic sarcoma arising from a cystosarcoma phyllodes is exceptional.Case...Full Text Available
BackgroundThe successful use of zirconia ceramics in orthopedic surgery led to a demand for dental zirconium-based implant systems. Because of its excellent biomechanical characteristics,...Full Text Available
Women experience a decline in estrogen and androgen levels after natural or surgically induced menopause, effects that are associated with a loss of sexual desire and bone mineral density. Studies in...Full Text Available
Adipose tissue is central to the regulation of energy balance. Two functionally different types of fat are present in mammals: white adipose tissue (WAT), the primary site of triglyceride storage,...Full Text Available
Most mechanical forces acting on the skeleton are generated either through impact with the ground (i.e., gravitational loading) or through muscle contractions (i.e., muscle loading). If one...Full Text Available
Forty cases of Ewing's sarcoma of various sites had attended the Department of Radiotherapy at the Wanless Hospital and the Miraj Medical Centre, attached to the Government Medical College, Miraj, Maharashtra, from January, 1970 through December, 1979. There were 28 male patients and 12 female patients in the series with a male to female ratio of 2.3:1. The youngest patient in the series was a female of 6 years of age with the tumour in the scapula and the oldest patient was a 32-year-old male with a lesion in the metacarpal bone. Sixty per cent of the cases were seen in the second decade. The average age of the patients was 13.5 years. The bones of the lower extremities were most commonly involved with the highest number (35 per cent) of the cases occurring in the femur. Involvement of the bones of the right side of the body was almost equal to that of the left side. Swelling over the site of the lesion and pain over the ...
Human bone marrow mesenchymal stem cells (BM-MSC) are multipotent progenitor cells that have transient immunomodulatory properties on Natural Killer (NK) cells, Dendritic Cells (DC), and T cells. This...Full Text Available
The case of an unusual late metastasis of neuroblastoma to the calcaneum, appearing as a sole recurrence 9 years after surgery, is reported. The radiographic features of the osseous lesion were very suggestive of primary bone malignancy, Ewing's sarcoma as the first option, with extraosseous spread to the soft tissues. (orig.).
This prospective study describes and evaluates a surgical approach for 3D reconstruction of the posterior maxilla with autogenous mandibular bone in 16 patients (mean age 51 years). Bone blocks were harvested from the mandible and used as lateral or vertical block grafts (onlay); they were also partially milled and used for sinus elevation (inlay). In 4 cases, anorganic bovine bone was added at the periphery of the blocks. 4 months after grafting, implants were placed in a second operation and loaded after 12 weeks. Lateral and vertical augmentations were measured immediately after grafting and at re-entry for implant placement. Mean lateral augmentation performed was 5.5mm, reduced to 4.3mm (p<0.01) after 4 months' healing. Mean vertical augmentation was 3.2mm, reduced to 2.1mm (p<0.01) a...
Immunotherapy has shown promise in a number of tumor types, but its exact role in sarcoma remains to be defined. Advanced bone and soft tissue sarcomas are challenging diseases to treat with an unmet...Full Text Available
Natural accumulations of skeletal material (death assemblages) have the potential to provide historical data on species diversity and population structure for regions lacking decades of wildlife monitoring,...Full Text Available
Ewing's sarcoma is the second most common malignant bone tumor in children and young adults. It is most prevalent between the ages of 10 and 15 years. There are present two cases of Ewing's sarcoma of the chest wall. The clinical, radiological and pathological features are described and the therapeutic options are discussed. (Author)
This case describes a 10-year-old girl who developed a Ewing's sarcoma in her proximal fibula. The radiologic features mimicked those of a unicameral bone cyst. The presence of pain and the atypical location led to a prompt biopsy and the correct diagnosis. The mechanism of this unusual radiographic presentation is discussed. (orig.)
Several drugs are available for the management of postmenopausal osteoporosis. This may, in daily practice, confuse the clinician. This manuscript offers an evidence-based update of previous treatment...Full Text Available
Hematopoietic stem cells replenish all the cells of the blood throughout the lifetime of an animal. Although thousands of stem cells reside in the bone marrow, only a few contribute to blood production...Full Text Available
Porous Nitinol (PNT) has found vast applications in the medical industry as interbody fusion devices, synthetic bone grafts, etc. However, the tendency of the PNT to corrode is anticipated to...Full Text Available
A suspension of bone marrow cells from femurs of female (CBA . C57B1)F1 mice was exposed to 2450 MHz CW microwaves in a specially designed waveguide exposure system. The temperature of the suspension rose, during exposure to microwaves, from 20/sup 0/C to 45/sup 0/C, and at an interval within 20/sup 0/C to 45/sup 0/C the number of haemopoietic stem cells (CFUs) was determined by the spleen exocolony method. The time of exposure of bone marrow cells to each temperature studied was 20 s. Control suspensions of bone marrow cells were exposed to a water bath temperature. There were no significant effects of the CFUs with the water bath temperature, while after exposure to microwaves the number of spleen colonies was elevated with a nadir at the temperature of 37/sup 0/C. With a microwave-induced increase of the temperature above 41/sup 0/C the number of CFUs in the bone marrow suspension decreased. The ...
Doxorubicin (DOX) is widely used in combination cocktails for treatment of childhood hematological cancers and solid tumors. A major factor limiting DOX usage is DOX-induced cardiotoxicity. However,...Full Text Available
Bone morphogenetic protein (BMP)-4 has a crucial role on primordial germ cells (PGCs) development in vivo which can promote stem cell differentiation to PG-like cells. In this study, we investigated the expression of Mvh as one of the specific genes in primordial germ cells after treatment with different doses of BMP4 on bone mesenchymal stem cells (BMSCs)-derived PGCs. Following isolation of BMSCs from male mouse femur and tibia, cells were cultured in medium for 72?h. Passage 4 murine BMSCs were characterized by CD90, CD105, CD34, and CD45 markers and osteo-adipogenic differentiation. Different doses of BMP4 (0, 0.01, 0.1, 1, 5, 25, 50, and 100?ng/ml) were added to BMSCs for PGCs differentiation during 4-days culture. Viability percent, proliferation rates, and expression of Mvh gene wer...
There has been a major interest in the drug treatment of osteoporosis and an increase in the number of drugs available in most countries. The ideal drug (one which increases or restores bone density...Full Text Available
Ewing sarcoma (ES) is the second most common type of primary bone malignancy in children and young adults. Survival rates for localized ES have improved to upwards of 70% with aggressive chemotherapy...Full Text Available
Objectives To clarify the relationship between bone mineral density (BMD) and body composition in Japanese women aged 18?40?years with low forearm BMD. Methods The subjects were Japanese199 women who had been selected for inclusion in the study based on a low forearm BMD determined at the Annual Women?s Health Examination. The subjects? mean (? standard deviation) age, body height, body weight, and body mass index (BMI) were 33.5 (?4.3) years, 158.1 (?5.1) cm, 49.6 (?5.7) kg, and 19.8 (?2.1), respectively. The BMD of the lumbar spine, total body, and left arm were measured using dual-energy X-ray absorptiometry (DXA). Fat mass (FM), bone-free lean tissue mass (LTM), and body fat percentage (BF%) were measured simultaneously with DXA. Results In the structural equation model, the standardiz...
Ewing's sarcoma is the second most common bone malignancy affecting children and young adults. The prognosis is especially poor in metastatic or relapsed disease. The cell of origin remains elusive,...Full Text Available
Dairy products doubly labeled with 45Ca and 47Ca were used to evaluate an extrinsic labeling procedure for calcium bioavailability determination. Nonfat milk, yogurt, and fresh cheese curd were prepared from caprine milk that was intrinsically labeled with 45Ca. The products were then labeled extrinsically with 47Ca and administered to rats by gavage. The 47Ca to 45Ca ratio in bone and teeth averaged about 1.00 with either milk, yogurt, or CaCl2, but the ratio was about 1.04 when dosed with cheese curd. Ca absorption, determined by whole-body counting of 47Ca, was lower (P less than 0.05) in cheese curd (59%) than in either milk (69%), yogurt (72%), or CaCl2 (72%). Expressed as percent of dose, the absorption of 47Ca was highly correlated with bone 47Ca (r = 0.973) and with bone 45Ca (r = 0.946). Correlation between tibia 47Ca and tibia 45Ca was r = 0.923. For the dairy products tested, our results indicated that extrinsic ...
Ligature-induced periodontitis was monitored for 6 months in eight Macaca mulatta monkeys to examine clinical status, radiographic bone level, and crevicular fluid (CF) levels of prostaglandin E2 (PGE2),...Full Text Available
PurposeThe aim of this study was to evaluate 3.5 years-cumulative survival rate of implants placed on augmented sinus using Osteon, a bone graft material, and to assess the height...Full Text Available
Purpose: To describe CT appearances in patients with unilateral cleft lip and palate (CLP) 20 years after bone graft surgery. Material and Methods: Eighteen consecutive patients with unilateral CLP were examined. All patients had been treated with primary closure, both in infancy and early childhood, supplemented with bone grafting at the age of around 10 years. The CT examination of the upper jaw included a dental CT program. The CT appearances of the cleft side were compared with those of the untreated non-cleft side. Results: Abnormal CT appearances included skew nasal aperture (n=17), nasal septal deviation (n=17), low floor of nasal aperture (n=15) at or towards the cleft side, and deviation of anterior nasal spine towards the non-cleft side (n=18). The posterior part of the bone cleft was visible in all patients, and the dental arch was V-shaped in 8. Conclusion: Although adherence to the present treatment protocol is ...
Purpose: To describe CT appearances in patients with unilateral cleft lip and palate (CLP) 20 years after bone graft surgery. Material and Methods: Eighteen consecutive patients with unilateral CLP were examined. All patients had been treated with primary closure, both in infancy and early childhood, supplemented with bone grafting at the age of around 10 years. The CT examination of the upper jaw included a dental CT program. The CT appearances of the cleft side were compared with those of the untreated non-cleft side. Results: Abnormal CT appearances included skew nasal aperture (n=17), nasal septal deviation (n=17), low floor of nasal aperture (n=15) at or towards the cleft side, and deviation of anterior nasal spine towards the non-cleft side (n=18). The posterior part of the bone cleft was visible in all patients, and the dental arch was V-shaped in 8. Conclusion: Although adherence to the present treatment protocol is ...
Context: Mild primary hyperparathyroidism (PHPT) is characterized by asymptomatic hypercalcemia, most commonly in the absence of classical signs and symptoms. Hence, there is need to characterize...Full Text Available
A goal of our research is to identify biochemical factors that underlie the susceptibility of bone marrow cell populations to benzene metabolites so as to develop a mechanistically based chemoprotective...Full Text Available