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PubMed2003

Hypertrophy of vascularized bone isograft in rats treated with cyclosporine A.

The aim of this study was to investigate the effects of cyclosporine A (CsA) on vascularized tibio-fibula isograft between 12-week-old male Lewis rats. After transplantation, 45 rats were randomly allocated to one of the following 7 treatment groups: (1) 4-week vehicle (n = 5), (2) 4-week CsA (n = 5), (3) 8-week vehicle (n = 10), (4) 8-week CsA (n = 10), (5) 4-week CsA followed by 4-week vehicle (n = 5), (6) 16-week vehicle (n = 5), or (7) 4-week CsA followed by 12-week vehicle (n = 5). In soft X-ray and micro-computed tomography examination, hypertrophic change of the grafted bones was apparent in the 4- and 8-week CsA groups. Mineral apposition rate and bone formation rate of the grafted bones in the 4-week CsA group were markedly higher than those in the 4-week vehicle group. In the 4- and 8-week CsA groups, however, bone mineral density (BMD) of the grafted bones was lower and strength of the reconstructed bones was weaker than the 4- and 8-week vehicle groups. Urinary deoxypyridinoline (DPD) level was higher in the 4- and 8-week CsA groups than in the 4- and 8-week vehicle groups. The group of 4-week CsA followed by 4-week vehicle had a level of urinary DPD equal to the 8-week vehicle group, but their BMD of the grafted bones was lower and strength of the reconstructed bones was weaker than the 8-week vehicle group. By contrast, the group of 4-week CsA followed by 12-week vehicle had BMD of the grafted bones and strength of the reconstructed bones similar to the 16-week vehicle group. These findings demonstrate that short-term CsA treatment induces hypertrophic change of vascularized bone graft with high-turnover bone loss, and strength of the reconstructed bone is gradually restored after the cessation of CsA treatment.

Amino Acids↗

PubMed2000

Fluorine-18 fluorodeoxyglucose PET in infectious bone diseases: results of histologically confirmed cases.

The aim of this study was to evaluate the clinical use of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in acute and chronic osteomyelitis and inflammatory spondylitis. The study population comprised 21 patients suspected of having acute or chronic osteomyelitis or inflammatory spondylitis. Fifteen of these patients subsequently underwent surgery. FDG-PET results were correlated with histopathological findings. The remaining six patients, who underwent conservative therapy, were excluded from any further evaluation due to the lack of histopathological data. The histopathological findings revealed osteomyelitis or inflammatory spondylitis in all 15 patients: seven patients had acute osteomyelitis and eight patients had chronic osteomyelitis or inflammatory spondylitis. FDG-PET yielded 15 true-positive results. The tracer uptake correlated with the histopathological findings in each case. Bone scintigraphy performed in 11 patients yielded ten true-positive results and one false-negative result. Follow-up carried out on two patients revealed normal or clearly reduced tracer uptake, which correlated with a normalisation of clinical data. In early postoperative follow-up it was impossible to differentiate between postsurgical reactive changes and further infection using FDG-PET. It is concluded that acute and chronic osteomyelitis of the peripheral as well as the central skeleton can be detected using FDG-PET. Osteomyelitis can be differentiated from soft tissue infection surrounding the bone. Unlike computed tomography and magnetic resonance imaging, FDG-PET is not affected by metal implants used for fixing fractures. FDG-PET demonstrated promising initial results with respect to treatment monitoring. Nevertheless, in the early postoperative phase FDG-PET seems to be of limited value owing to unspecific tracer uptake.

Adult↗

PubMed2005

Modeling initial strain distribution in soft tissues with application to arteries.

A general theory for computing and identifying the stress field in a residually stressed tissue is presented in this paper. The theory is based on the assumption that a stress free state is obtained by letting each point deform independently of its adjacent points. This local unloading represents an initial strain, and can be described by a tangent map. When experimental data is at hand in a specific situation, the initial strain field may be identified by stating a nonlinear minimization problem where this data is fitted to its corresponding model response. To illustrate the potential of such a method for identifying initial strain fields, the application to an in vivo pressure-radius measurement for a human aorta is presented. The result shows that the initial strain is inconsistent with the strain obtained with the opening-angle-method. This indicates that the opening-angle-method has a too restrictive residual strain parameterization, in this case.

Algorithms↗

PubMed1984

A soft-tissue cephalometric analysis and its use in orthodontic treatment planning. Part II.

To summarize, the soft-tissue profile can vary in many ways and still be in balance and harmony. There is a wide range of acceptability regarding soft-tissue chin position in the profile. Both the lips and the chin should line up near the H line, but we need to look at the upper lip from a different perspective or in its relation to a line perpendicular to the Frankfort plane and tangent to the vermilion border to be certain that we are planning the best possible lip support for the case at hand. The H angle, allowing a few degrees for soft-tissue thickness variability, must increase as the basic skeletal convexity increases, and as the convexity increases, the lower incisors will need to be left farther forward than in a straight or concave skeletal profile. A thick integumental covering in the chin area can also effectively align the lower facial profile where lower incisors are farther forward than we are accustomed to seeing them. This principle can also be applied by surgically moving the bony chin forward until the three key soft-tissue points line up. Because there are wide variations in skeletal convexity, standardizing the position of the lower incisor to its apical base support as measured in the Frankfort mandibular incisor angle fails to recognize that upper incisors can be retracted too far, leaving a "streamlined" upper lip which is not esthetically pleasing. Locating the lower incisor in relation to the expected point A to pogonion line is somewhat better but still fails to recognize the wide range of variability in the thickness of the lips and soft-tissue chin. We must also guard against "dishing" those cases having good facial balance with quite normal skeletal convexity and only 5 mm or 6 mm of lower arch length discrepancy. Finally, it is completely practical as a treatment-planning procedure to approach the proposed orthodontic changes from a soft-tissue analysis perspective, making changes only to the point where the best possible soft-tissue profile is established, and then compute the tooth movement necessary to develop ideal profile relationships. The visualized treatment objective, or VTO, is the vehicle that I use to accomplish this.

Adult↗

PubMed1989

An evaluation of the changes in soft-tissue profile form induced by orthodontic therapy.

In view of the growing concensus that traditional cephalometric appraisals yield data of dubious scientific value, the changes in soft-tissue profile forms were evaluated by an alternative technique. This involved dividing the soft-tissue profile form into a series of triangular finite elements spanning homologous datum points. With the use of techniques derived from continuum mechanics, the changes in soft-tissue profile form were evaluated by computing the degree of distortion in each triangle after treatment (target element) compared with the triangle before treatment (reference element) in terms of specific size and shape parameters. In a comparison of samples of patients with Class I and II malocclusion, varying patterns of facial profile change were noted, depending on the parameters analyzed. The results, therefore, showed that although such techniques offer rigorous cephalometric potential, further investigation is required to identify more appropriate datum points.

Cephalometry↗

PubMed1993

The significance of pulmonary nodules detected on CT staging for lung cancer.

Small pulmonary nodules of soft tissue density are often found during computed tomography for the staging of lung cancer, but CT cannot reliably distinguish benign from malignant uncalcified pulmonary nodules. The purpose of this study was to assess the significance of pulmonary nodules discovered on staging CT. 551 patients with lung cancer who had a staging CT and who were considered operable were studied. Eighty-eight patients (16%) were found to have small non-calcified pulmonary nodules. Adequate follow-up was possible in 25 patients who had a total of 36 nodules. Twenty-five nodules (70%) were subsequently confirmed to be benign, four (11%) were malignant and the nature of seven (19%) could not be determined. The high prevalence of benign nodules in this population should be taken into account when staging lung cancer.

Aged↗

PubMed2000

Internal orbital fractures in the pediatric age group: characterization and management.

OBJECTIVE: To evaluate the specific characteristics and management of internal orbital fractures in the pediatric population. DESIGN: Retrospective observational case series. PARTICIPANTS: Thirty-four pediatric patients between the ages of 1 and 18 years with internal orbital ("blowout") fractures. METHODS: Records of pediatric patients presenting with internal orbital fractures over a 5-year period were reviewed, including detailed preoperative and postoperative evaluations, surgical management, and medical management. MAIN OUTCOME MEASURES: Ocular motility restriction, enophthalmos, nausea and vomiting, and postoperative complications. RESULTS: Floor fractures were by far the most common fracture type (71%). Eleven of 34 patients required surgical intervention for ocular motility restriction. Eight were trapdoor-type fractures with soft-tissue incarceration; five had nausea and vomiting. Early surgical intervention (<2 weeks) resulted in a more complete return of ocular motility compared with the late intervention group. CONCLUSIONS: Trapdoor-type fractures, usually involving the orbital floor, are common in the pediatric age group. These fractures may be small with minimal soft-tissue incarceration, making the findings on computed tomography scans quite subtle at times. Marked motility restriction and nausea/vomiting should alert the physician to the possibility of a trapdoor-type fracture and the need for prompt surgical intervention.

Adolescent↗

PubMed2002

Sclerosing extramedullary hematopoietic tumor.

A 73-year-old woman presented with abdominal pain, weakness, and weight loss. Pertinent medical history included myelofibrosis, severe anemia, and lumpectomy for breast cancer. Computed tomography showed marked splenomegaly and numerous soft tissue masses in the mesentery. Excisional biopsy of the mass showed an encapsulated tumor with yellow-tan nodular growth pattern. Microscopically, the tumor was characterized by the presence of bizarre giant cells in background of prominent dense fibrous stroma. The atypical giant cells were positive for FVIII antibody staining. Many other cells were positive for CD43 antibody staining, indicating that the tumor was hematopoietic in nature, so-called sclerosing extramedullary hematopoietic tumor. Extramedullary hematopoiesis is a common phenomenon associated with severe anemia of any cause. When associated with myelofibrosis, however, it has different morphology from extramedullary hematopoiesis of the other causes. The significance of recognizing sclerosing extramedullary hematopoietic tumor is that it is often mistaken for sarcomas and other malignant neoplasms, especially when the clinical history is unknown.

Aged↗

PubMedDate not supplied

Chondrosarcoma of the distal phalanx of the second toe: a case report.

Although chondrosarcoma is a relatively common malignant bone lesion, these lesions rarely affect the foot. This article presents the case of a 32-year-old woman with a chondrosarcoma in the distal phalanx of the right second toe. Radiography and computed tomography showed cortical disruption and soft-tissue expansion. Histologically, the tumor was classified as grade 2 chondrosarcoma according to the American Joint Committee of Cancer pathologic staging system. Amputation at the distal half of the second proximal phalanx was performed to obtain clear surgical margins. A literature review and discussion of salient diagnostic and treatment issues is included.

Adult↗

PubMed2002

Nasopharyngeal polyps in cats.

Nasopharyngeal polyps are non-neoplastic, inflammatory growths that arise from the middle ear or the eustachian tube and extend into the pharynx. The exact etiology of nasopharyngeal polyps is unclear; proposed etiologies include a response to chronic upper respiratory tract infection, chronic otitis media, ascending infection from the nasopharynx, or a congenital origin. Clinical signs usually relate to obstruction of the nasopharynx, with Horner's syndrome and head tilt being consistent with otitis media and otitis interna, respectively. Diagnostic tools include digital or visual examination above the soft palate, flexible fiberoptic caudal rhinoscopy, radiography, computed tomography, and magnetic resonance imaging. Ventral bulla osteotomy combined with traction removal of the polyp is the recommended treatment, although traction only followed by prednisolone therapy can be considered in some cases, especially when there is no evidence of otitis media.

Animals↗

PubMed1992

[The solitary pulmonary histoplasmoma].

A 63-year-old man who grows orchids as a hobby, fell ill with weakness and pain in his hips and legs 2 months after his latest trip to South America (Ecuador). The WBC count was 9900/microliters with unremarkable differential count while blood sedimentation rate was raised to 60/100 mm. The chest X-ray demonstrated in the right upper lobe a well-circumscribed coin lesion (3 cm diameter) of soft-tissue density, uncalcified and without cavitation. Computed tomography in addition revealed an enlarged lymph-node at the lower hilar pole, but no mediastinal lymphoma. Bronchoscopy demonstrated narrowing of a subsegmental ostium of the 6th segment on the right. An attempt at transbronchial biopsy failed. As a peripheral bronchial carcinoma was suspected, a posterolateral thoracotomy was performed (4 months after the trip to Ecuador). Rapid histological examination was negative for tumour and the lesion was therefore enucleated. Histologically (Grocott silver staining) a histoplasmoma was diagnosed. Several serum samples were positive for precipitating (M-band) and complement-binding antibodies (titre 12 days preoperatively was 1:16). The postoperative course was without complication. No anti-histoplasma antibodies were demonstrable 1 year postoperatively.

Antibodies, Fungal↗

PubMed2006

Effect of using an echogenic catheter for ultrasound-guided embryo transfer in an IVF programme: a prospective, randomized, controlled study.

BACKGROUND: Recent evidence showed that ultrasound-guided embryo transfer significantly increases successful implantation compared to the clinical touch method. It has been postulated that new echodense catheters which are more readily detectable by ultrasound may refine transfer techniques even more, thus improving IVF outcome. METHODS: A prospective, randomized, controlled trial comparing IVF outcome for women undergoing embryo transfer under ultrasound guidance by a single healthcare provider with random assignment according to a computer-generated randomization table to either standard soft Wallace catheter (standard catheter group, n=95) or the new echogenic soft Wallace catheter (echogenic catheter group, n=98). RESULTS: The use of the echodense catheter facilitated catheter identification under ultrasound, and thus the duration of the embryo transfer procedure since the loaded catheter was handed to the physician and up to embryo discharge was significantly shorter in the echogenic catheter group as compared with the standard catheter group. There were 39 and 53 clinical pregnancies in the standard catheter (41%) and echogenic catheter (54.1%) groups, respectively. This was not statistically significant (P=0.08) according to the OR (0.6) and CIs (0.33-1.04). However, twin pregnancy rate was significantly increased (P<0.01) with the use of the new catheter which was the underlying source for obtaining significant increase in implantation rate in this group (37.1%) as compared with the standard catheter group (23.2%). CONCLUSION: This pilot study suggests that the use of the echogenic Wallace catheter simplifies ultrasound-guided embryo transfer but not definite benefit in terms of pregnancy rates was obtained. In contrast, the use of the new catheter was associated with a significant increase in the number of twin pregnancies.

Adult↗

PubMed2000

Langerhans histiocytosis of temporal bone: role of magnetic resonance imaging.

Langerhans cell histiocytosis (LCH) may involve nearly every organ of the body. In children, head and neck involvement has been reported in as many as 82% of patients. Sites of head and neck involvement include skull, temporal bone, orbit, mandible, maxilla and cervical nodes. In addition, patients may have coexisting central nervous system (CNS) involvement adjacent to, or remote from, osseous lesions. Magnetic resonance imaging (MRI) of the temporal bone in patients with LCH is ideal for evaluating the extracranial extent of the soft-tissue mass and is complementary to computed tomography (CT) in the assessment of osseous erosion. MRI is superb in the evaluation of intracranial extension, usually into the middle cranial fossa, and of patency of adjacent vascular structures. It is the imaging modality of choice to evaluate patients with suspected CNS involvement of LCH, which includes lesions of the infundibulum, cerebrum, cerebellum, and extra-axial spaces.

Adult↗

PubMedDate not supplied

CT and MR findings in parameningeal leukaemic masses.

This study presents the clinical and imaging findings in seven patients with parameningeal leukaemic masses: four adults with granulocytic sarcoma and three children with soft tissue masses from acute lymphoblastic leukaemia. Computed tomography and magnetic resonance imaging were helpful in detecting these masses and in showing their extent. Magnetic resonance was particularly valuable in demonstrating abnormal bone marrow in the adult patients with granulocytic sarcoma. Computed tomography was valuable in demonstrating leukaemic relapse in the children when examination of CSF or bone marrow showed no evidence of leukaemia.

Adult↗

PubMed2004

Herniation of a calcified cervical disc into the foramen transversarium in an 8-year-old child.

STUDY DESIGN: Herniation of a calcified C3-C4 disc into the left foramen transversarium in a child is reported. OBJECTIVE: To discuss the natural history and management of a calcified disc herniation into the foramen transversarium. SUMMARY OF BACKGROUND DATA: Cervical disc calcification in children usually follows a benign course. Herniation of the calcified disc into the spinal canal has already been described. However, herniation into the foramen transversarium has never been reported. METHODS: An 8-year-old girl presented with progressive neck pain and torticollis. Her neurologic examination was normal. She was treated using a head halter traction, analgesics, and muscle relaxants for 3 days, followed by the use of a soft cervical collar for 2 weeks. RESULTS: Computed tomography scan showed a calcified C3-C4 disc with herniation into the C3 left foramen transversarium. Her symptoms subsided and she rapidly regained full range of motion of her neck after 3 days of conservative treatment. Magnetic resonance angiography done after 2 months did not show any residual compression of the left vertebral artery. After 3 months, the herniation had completely disappeared, whereas only a small central calcification remained in the C3-C4 disc space. CONCLUSION: The natural history of cervical disc calcification is usually benign. A computed tomography scan can be performed for patients in whom a calcified disc herniation is suspected on the plain films. In this case of herniation into the foramen transversarium, magnetic resonance angiography was useful to evaluate the integrity of the vertebral arteries. Spontaneous resolution of the herniated disc and return to normal function can be expected with conservative treatment.

Calcinosis↗

PubMedDate not supplied

Orbital desmoid tumor in a pediatric patient.

A 3-year-old girl with desmoid tumor of the right orbit initially presented with a 4-month history of unilateral ptosis and was subsequentially found to have fullness of the right upper eyelid. Computed tomography of the orbit revealed a soft tissue density in the superolateral quadrant of the right orbit. Histopathology from a biopsy revealed a desmoid tumor with positive margins. The patient subsequently underwent compete excision of the tumor and is presently doing well.

Biomarkers, Tumor↗

PubMed2005

Update on eustachian tube dysfunction and the patulous eustachian tube.

PURPOSE OF REVIEW: The purpose of this review is to summarize the recent knowledge on eustachian tube dysfunction and the patulous eustachian tube. RECENT FINDINGS: A clinically useful test for eustachian tube function is still lacking. Narrowing of the isthmus alone was demonstrated to be an insufficient cause of otitis media. Inflammatory mediators identified within the eustachian tube and middle ear cells were causally linked with otitis media with effusion. Increasing evidence was found that allergic disease and reflux may be two of the most important contributors of tubal inflammation causing otitis media with effusion. The adenoid size and proximity to the torus tubaris may also be important in considering which patients with persistent otitis media with effusion may benefit from adenoidectomy. Computed tomography scan has documented loss of soft tissue within the cartilaginous eustachian tube in patients with patulous eustachian tubes. An endoscopic approach to seal the tubal lumen has been found to be effective in relieving patulous symptoms. SUMMARY: These studies suggest that allergic rhinitis and gastroesophageal reflux should be investigated in patients with eustachian tube dysfunction. Adenoidectomy should also be considered in patients who have adenoids that obstruct the torus tubaris. Patients with a patulous eustachian tube may benefit from an endoscopic closure. Further research is needed to identify a clinically useful test for eustachian tube dysfunction.

Ear Diseases↗

PubMed2000

Elastic constants from microscopic strain fluctuations

Fluctuations of the instantaneous local Lagrangian strain epsilon(ij)(r,t), measured with respect to a static "reference" lattice, are used to obtain accurate estimates of the elastic constants of model solids from atomistic computer simulations. The measured strains are systematically coarse-grained by averaging them within subsystems (of size L(b)) of a system (of total size L) in the canonical ensemble. Using a simple finite size scaling theory we predict the behavior of the fluctuations as a function of L(b)/L and extract elastic constants of the system in the thermodynamic limit at nonzero temperature. Our method is simple to implement, efficient, and general enough to be able to handle a wide class of model systems, including those with singular potentials without any essential modification. We illustrate the technique by computing isothermal elastic constants of "hard" and "soft" disk triangular solids in two dimensions from Monte Carlo and molecular dynamics simulations. We compare our results with those from earlier simulations and theory.

Journal Article↗