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At least 1,189 records · Page 66Linked to original sources
PubMed1999

Factors associated with tumor volume and primary metastases in Ewing tumors: results from the (EI)CESS studies.

BACKGROUND: Tumor volumes of more than 100 ml and the presence of primary metastases have been identified as determinants of poor prognosis in patients with Ewing tumors. We sought to assess the prevalence of critical tumor size and primary metastases in a large national sample of patients at the time of first diagnosis and to identify factors that are associated with their occurrence. PATIENTS: The present report is based on data of 945 German patients who were enrolled into the (EI)CESS therapy studies between 1980 and 1997. It is assumed that registration of German patients with Ewing tumors under the age of 15 years was almost complete since around 1985. Diagnoses of primary tumors were ascertained exclusively by biopsies. Analyses were restricted to patients with Ewing tumors of bone due to the few occurrences in soft tissues. METHODS: Tumor volume data as assessed by radiography, computed tomography or nuclear magnetic imaging were available for 821 patients. The diagnosis of primary metastases was based on thoracic computed tomography or on whole body bone scans in 936 patients. Suspicious lesions had to be confirmed by bone marrow biopsies. We explored how year of first diagnosis, age at first diagnosis, sex, histological subtype and site of the primary tumor related to tumor size and presence of metastases by univariate and multivariate statistical techniques. RESULTS: Sixty-eight percent of the patients (n = 559) had a volume above 100 ml with smaller tumors being more common in childhood than in late adolescence and early adulthood. Extensive volumes were observed in almost 90% of the tumors located in femur and pelvis while they were less common in other sites (P < 0.001). On average, 26% of all patients presented with clinically apparent primary metastases. The detection rate of metastases was markedly higher in patients diagnosed after 1991 (P < 0.001). Primary metastases were also significantly more common for tumors originating in the pelvis and for peripheral neuroectodermal tumors (PNET; P < 0.01). Tumors greater than 100 ml were positively associated with metastatic disease (P < 0.001). Multivariate analyses, which included simultaneously all univariate predictors in a logistic regression model, indicated that most of the observed associations were essentially unconfounded. The adjusted odds ratios (OR) for the presence of tumor volumes > or = 100 ml were OR = 1.5 per age rise of 10 years, and OR = 5.8 for pelvis and OR = 7.1 for femur as primary tumor site (all P < 0.001). The presence of metastases was significantly associated with the year of diagnosis (OR = 1.9, after 1991 vs. before 1986), pelvis as site of the primary tumor (OR = 1.8), a PNET (OR = 1.5), and tumor size > or = 100 ml (OR = 1.6). CONCLUSIONS: In conclusion, we find that the prevalence of established factors for an unfavorable prognosis is disturbingly high among patients diagnosed with Ewing tumors. Recent progress in imaging techniques seems to account for much of the rise in the detection rate of metastases after 1991. We identify age and, in particular pelvic and femoral site as the major determinants of local tumor extension. Occurrence of primary metastases is independently related to tumor size, pelvic site, and PNET.

Adolescent↗
PubMed1997

Oculopalatal myoclonus: eye movement studies, MRI findings and the difficulty of treatment.

Two cases of oculopalatal myoclonus with bilateral horizontal gaze palsies are presented. The abnormal vertical eye movements developed several months after brain stem haemorrhage. Eye movement measurements showed rhythmical vertical eye movements at similar rates (2.3 Hz and 2.4 Hz), unaffected by attempts to fixate, converge or gaze in any direction. T2-weighted MRI scans showed bilateral enlargement of the inferior olivary nuclei in both cases, which confirms the expected pathology previously demonstrated on autopsy. Both patients had severe oscillopsia and an attempt was made to improve this by bilateral disinsertion of the vertical rectus muscles. The pendular eye movements continued but were greatly reduced, in one case enough to relieve the oscillopsia. However, after 6 months retrobulbar botulinum toxin was required to continue to provide relief from the oscillopsia. Other treatment options, including pharmacological agents, are discussed.

Aged↗
PubMed2004

[Use of vacuum therapy during defect coverage of the upper extremity with microsurgically grafted arterialized venous flaps].

Arterialized venous soft tissue flaps are defined as tissue portions usually harvested from the anterior and distal third of the forearm over a venous pathway to be transplanted to another recipient area. Basically, they are composed of skin, subcutaneous tissue, and subdermal venous plexus. At the recipient site flaps are perfused by a nourishing artery while the other veins are connected to one or more regional veins. The retrograde blood perfusion often results in edema, temporary epidermolysis, or even some degree of skin necrosis that disappear during subsequent treatment. To circumvent these drawbacks grafting of arterialized flaps was combined with local application of vacuum to overcome the venous initial stasis, resulting in improved healing and survival of these flaps.

Adult↗
PubMed2004

[Salvage of exposed alloplastic materials in irradiated wounds - a case report].

BACKGROUND: Modern multimodal concepts of complex reconstructions and advanced wound management enlarge strategies for surgical oncological therapies. One of the mainstays of classical surgical therapy in case of exposed alloplastic materials in irradiated wounds was to remove the foreign body due to the risk of infection. This loss of integrity and function of the contaminated host bed was to allow wound healing and closure. METHOD: We report the management of a 56-year-old female patient who developed a lyomyosarcoma at her left shoulder girdle 8 years after radiation of the left thorax because of breast cancer. After radical tumor resection and exarticulation of her left arm in the shoulder joint a necrosis of the soft tissue envelope developed, leading to an exposed alloplastic mesh. Staged debridement and continuous application of negative pressure was performed three times. Ultimate plastic coverage was performed by means of a pectoralis myocutaneous island flap from the other breast. RESULTS: After staged debridement and repeated vacuum application excellent wound cleaning, neovascularisation, wound contraction and formation of granulation tissue within the previously irradiated tissue zone was observed. Until fourteen months postoperative wound coverage remained stable and no signs of infection were observed. DISCUSSION: By means of negative pressure therapy even in radiated wounds excellent wound cleaning and sufficient formation of granulation tissue can be achieved. In some cases negative pressure therapy together with staged debridement allows reintegration of exposed and therefore potentially contaminated alloplastic meshes into new formed granulation tissue in radiated wounds respectively radiation ulcers. Thus leading to the possibility of ultimate plastic coverage.

Breast Neoplasms↗
PubMed2004

[The V.A.C. system (vacuum assisted closure) as bridging between primary osteosynthesis in conjunction with functional reconstructed of soft tissue--open fractures type 2 and type 3].

Open fractures are complex injuries affecting the integrity of bones and adjacent soft tissue. The therapeutic goals in dealing with open fractures should consist of primary osteosynthesis in conjunction with functional reconstruction of soft tissue. In a period over 2 years, 26 patients were treated with extensive trauma in an interdisciplinary approach. These patients suffered from open fractures type 2 and 3. All patients were treated by primary osteosynthesis, and temporary wound closure with V.A.C.-system. Definitive wound closure was achieved by day 31 after injury. In contrast to a review of the pertinent literature we report the successful free tissue transfer in 21 patients during the critical period between 72 hours and several months preceded by the use of V.A.C.-system for the temporary coverage of open wounds.

Adult↗
PubMed2005

Head-and-neck IMRT treatments assessed with a Monte Carlo dose calculation engine.

IMRT is frequently used in the head-and-neck region, which contains materials of widely differing densities (soft tissue, bone, air-cavities). Conventional methods of dose computation for these complex, inhomogeneous IMRT cases involve significant approximations. In the present work, a methodology for the development, commissioning and implementation of a Monte Carlo (MC) dose calculation engine for intensity modulated radiotherapy (MC-IMRT) is proposed which can be used by radiotherapy centres interested in developing MC-IMRT capabilities for research or clinical evaluations. The method proposes three levels for developing, commissioning and maintaining a MC-IMRT dose calculation engine: (a) development of a MC model of the linear accelerator, (b) validation of MC model for IMRT and (c) periodic quality assurance (QA) of the MC-IMRT system. The first step, level (a), in developing an MC-IMRT system is to build a model of the linac that correctly predicts standard open field measurements for percentage depth-dose and off-axis ratios. Validation of MC-IMRT, level (b), can be performed in a rando phantom and in a homogeneous water equivalent phantom. Ultimately, periodic quality assurance of the MC-IMRT system is needed to verify the MC-IMRT dose calculation system, level (c). Once the MC-IMRT dose calculation system is commissioned it can be applied to more complex clinical IMRT treatments. The MC-IMRT system implemented at the Royal Marsden Hospital was used for IMRT calculations for a patient undergoing treatment for primary disease with nodal involvement in the head-and-neck region (primary treated to 65 Gy and nodes to 54 Gy), while sparing the spinal cord, brain stem and parotid glands. Preliminary MC results predict a decrease of approximately 1-2 Gy in the median dose of both the primary tumour and nodal volumes (compared with both pencil beam and collapsed cone). This is possibly due to the large air-cavity (the larynx of the patient) situated in the centre of the primary PTV and the approximations present in the dose calculation.

Algorithms↗
PubMed1991

Neurological features of cranial vault lymphomas: report of two cases.

Two patients who had focal neurological deficits as the initial manifestation of a malignant non-Hodgkin's lymphoma involving the skull are described. Soft-tissue masses and variable bone destruction were the predominant computed tomographic findings, and magnetic resonance imaging studies revealed meningeal involvement in one case and sinus thrombosis in the other. Malignant non-Hodgkin's lymphomas initially appearing in the skull are rare, but these lesions should be considered in patients with a palpable scalp mass who have focal neurological signs.

Adult↗
PubMed2003

Effective interactions between inclusions in complex fluids driven out of equilibrium.

The concept of fluctuation-induced effective interactions is extended to systems driven out of equilibrium. We compute the forces experienced by macroscopic objects immersed in a soft material driven by external shaking sources. We show that, in contrast with equilibrium Casimir forces induced by thermal fluctuations, their sign, range, and amplitude depend on specifics of the shaking and can thus be tuned. We also comment on the dispersion of these shaking-induced forces, and discuss their potential application to phase ordering in soft materials.

Journal Article↗
PubMed2001

The effect of interocclusal appliances on temporomandibular joints as assessed by 3D reconstruction of MRI scans.

Magnetic resonance imaging (MRI) enables simultaneous visualization of hard and soft tissues. The aims of the present study were to computer generate three-dimensional (3D) images, reconstructed from MRI scans of normal temporomandibular joints (TMJ), to assess the relative positions of the disc, condyle and articular surface of the temporal bone and to study the effect of two mandibular group function interocclusal appliances (IOAs). Bilateral MRI scans of 2 mm slice thickness were generated for the TMJs of 12 asymptomatic subjects with the image acquisition coils orientated in a corrected oblique sagittal plane. MRI scans were generated for all subjects with 3 mm interincisal distance IOAs, while a subgroup (n = 4) was also scanned with a 5 mm interincisal IOA in situ. An average of 10 slices through each TMJ were generated for the closed mouth and IOA positions. Three-dimensional reconstruction was performed on a 486 IBM compatible computer using a suite of nine programs not commercially available. Three-dimensional images allowed visualization of composite images of joint relationships. Subjective assessment indicated that joint relations in 3D were more informative than multiple separate 2D MRI scans. With the 3 mm IOA in situ, the disc was positioned posteriorly and superiorly to the condyle in three of 12 cases. In four of 12 cases the condyle, and in two of 12 cases both the disc and condyle, were positioned anteriorly and inferiorly. With the 5 mm IOA changes in condyle/disc and condyle/fossa relationships were more variable. It was concluded that 3D images of TMJs enabled the assessment of the positional changes of the condyle/disc and condyle/fossa relationships as altered by IOAs. However, the role of IOAs on the internal arrangements within the TMJ remains variable and is deserving of further study.

Adult↗
PubMed1991

Anticipatory velar lowering: a coproduction account.

Feature spreading and coproduction models make fundamentally different assumptions about the nature and organization of speech motor control, and yet each model is supported by some, but not all, of the existing empirical data. This has led some researchers to conclude that speakers probably use alternative strategies at different times. This study suggests that the identification of coarticulatory influences requires the concurrent identification of intrinsic articulatory characteristics of the segment. Moreover, the evidence for feature spreading or variable coarticulation strategies derives from the misidentification of such intrinsic characteristics as context effects. This velar coarticulation study used a controlled comparison between CVnN and CVnC minimal pairs, where C is an oral consonant, Vn is any number of vowels, and N is a nasal consonant. Vocalic string duration was manipulated by varying the number of segments and speech rate, allowing us to alter the time between the onsets of vocalic and subsequent consonantal gestures. Velar lowering occurred in CVn sequences, whether or not a nasal consonant followed, and similar vocalic gestures were observed across minimally contrastive environments with and without the nasal consonant. Moreover, velar lowering for the nasal consonant began in close temporal proximity to the nasal murmur. These results strongly support the coproduction model and provide insight into previously conflicting reports.

Humans↗
PubMed1994

Thymolipoma: analysis of 27 cases.

PURPOSE: To characterize the radiologic features of thymolipoma. MATERIALS AND METHODS: Twenty-seven cases of thymolipoma were reviewed. Clinical, radiologic, and pathologic findings were noted. RESULTS: The masses occurred in 15 male and 12 female patients (mean age, 26.7 years). All 27 tumors were in the anterior mediastinum; 22 were in the anterior inferior mediastinum. On frontal radiographs, 12 tumors simulated cardiomegaly. On lateral radiographs, 12 tumors draped over the ipsilateral hemidiaphragm, simulating diaphragmatic elevation. Computed tomographic scans (n = 11) demonstrated a mixture of fat and soft-tissue attenuation in 10 tumors corresponding to adipose and thymic elements found at microscopy. Magnetic resonance images (n = 2) demonstrated fat and soft-tissue signal intensity characteristics. Both types of studies showed a connection between tumor and thymus. CONCLUSION: Thymolipomas are anterior mediastinal masses that may conform to the shape of adjacent structures. The diagnosis is supported by imaging studies that demonstrate fat and soft tissue within the tumor.

Adipose Tissue↗
PubMed2006

Progress in sinonasal imaging.

Imaging of sinonasal structures has evolved from standard radiographs to the much more complicated and informative techniques used today. The plain radiograph was useful when the surgical techniques practiced were primarily aimed at the maxillary and frontal sinuses. With a better understanding of the mucociliary clearance of the nasal cavity and the paranasal sinuses, the surgical technique was shifted to the ethmoid sinuses and became more focal, thus needing a better understanding and display of the intricate morphology of the nasal cavity and paranasal sinuses. Polytomography was a step above plain radiographs and was first used in the display of the regional anatomy for the development of functional endoscopic sinus surgery. Polytomography was quickly replaced by computed tomography, as this imaging technique provides a much more detailed view of the sinonasal architecture than does polytomography. Magnetic resonance imaging has also shown usefulness in imaging this morphological area, as it provides better soft tissue resolution, but it does not allow good visualization of bony structures. Newer computer systems with software capable of reconstructing the digitized information into a 3-dimensional display further enhance our understanding of the regional morphology and afford an improved means of correlating the imaging and endoscopic information. Furthermore, stereotactic navigation systems allow surgeons the ability to visualize the endoscope-instrument tip position, as instruments are actively being used during surgery, on the computed tomographic and/or magnetic resonance images. There is a persistent trend toward reducing the size of the imaging equipment to render it more mobile (computed tomography) and adapt it for operating room use.

Chronic Disease↗
PubMed1997

Osteoclasts are present in gp130-deficient mice.

Interleukin (IL)-6, IL-11, leukemia inhibitory factor, and oncostatin M similarly induce osteoclast formation in cocultures of osteoblastic cells and bone marrow cells. These cytokines share a common signal transducer, gp130, which forms a receptor complex with the specific receptor for each cytokine. To investigate the role of gp130 in osteoclast development, we examined bone tissues in gp130-deficient and wild-type newborn mice of the ICR background. Soft x-ray radiographs and microfocus x-ray computed tomographs revealed that bone marrow cavities were present in tibiae and radii of both wild-type and gp130-deficient mice. Microfocus x-ray computed tomography and histological examination demonstrated a decrease in the amount of trabeculae at the metaphysial region in tibiae and radii of the gp130-deficient mice compared with the wild-type mice. The number ofosteoclasts in gp130-deficient mice was about double that in the wild-type mice. There were no apparent differences in the distributions of alkaline phosphatase-positive osteoblasts and the osteoid surface on the trabecular bone at the metaphysial region between the wild-type and gp130-deficient mice. The volume of mineralized trabecular bones was also decreased at mandibulae, accompanied by the increased number of osteoclasts in gp130-deficient mice compared with the wild-type and heterozygous mice. These results suggest that the formation of osteoclasts is not solely dependent on gp130 signaling, at least during fetal development. The osteoclastic bone resorption in gp130-deficient mice may be caused by the functional redundancy of bone-resorbing hormones and cytokines other than those of the IL-6 family.

Animals↗
PubMed2004

Unilateral levator claviculae muscle mimicking cervical lymph node enlargement in a patient with ameloblastoma.

We present a case of a 24-year-old man with an ameloblastoma of the mandible, in whom a soft tissue lesion was noted at pre-operative axial computed tomography (CT). This was demonstrated to be a unilateral levator claviculae muscle following multiplanar reformation. The levator claviculae is a relatively uncommon and little reported normal variant. It is of particular importance in head and neck carcinoma where it may be confused radiologically with lymphadenopathy and lead to inappropriate management.

Adult↗
PubMed1978

Radiologic soft tissue shadows in the pelvis: another look.

In patients with adequate amounts of intramuscular fat, the normal contours of the muscles of the pelvic floor and side-walls may be visualized on plain radiographs. Knowledge of the relationships of these muscles to surrounding structures has been facilitated by computed tomography. Obliteration of the medial margin of the psoas muscle with an attendant soft tissue mass implies pathology in the region of the medial chain of external iliac lymph nodes; similarly, obliteration of the obturator internus shadow suggests internal iliac adenopathy. Nonnodal masses in these regions can cause similar radiographic abnormalities. The normal shadow of the piriformis muscle may simulate external iliac adenopathy. Pitfalls which may lead to overinterpretation are discussed.

Adipose Tissue↗