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In addition to the patient's history and a thorough clinical investigation, magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ) has been introduced to complete the findings for the diagnosis of internal derangement of the TMJ. However, 'dynamic information' is desirable to help us to understand the mechanism of internal derangement. This information is given for example by electronic axiography recording systems. The lack of any ability to assess joint function dynamically in MRI is a point of criticism. Using a computer-driven pseudodynamic MRI system (CINE mode) 'dynamic information' should be now available. In this investigation 21 patients with TMJ disorders were examined using both conventional static MRI and CINE mode. For the diagnosis of an anterior displaced disc with or without reduction in 18 cases (86%) it was only necessary to consider two static MRIs: a closed mouth position and a maximal open mouth position. Comparison showed there was no advantage in using CINE mode. Contrast and resolution of the static MRIs were shown to be better and so additional findings such as joint effusion and disc deformation could be diagnosed on static MRIs with greater certainty. Only in three (14%) cases was the dynamic information from CINE mode useful for the diagnosis of the displacement of the disc.  相似文献   
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The documented trophic actions of the neurotrophins brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4/5 (NT-4/5) upon ventral mesencephalic dopamine neurons in vitro and in vivo are presumed to be mediated through interactions with their high-affinity receptors TrkB (for BDNF and NT-4/5) and TrkC (for NT-3). Although both neurotrophin receptor mRNAs have been detected within the rat ventral midbrain, their specific association with mesencephalic dopaminergic cell bodies remains to be elucidated. The present study was performed to determine the precise organization of trkB and trkC mRNAs within rat ventral midbrain and to discern whether the neurotrophin receptor mRNAs are expressed specifically by dopaminergic neurons. In situ hybridization with isotopically labeled cRNA probes showed that trkB and trkC mRNAs were expressed in all mesencephalic dopamine cell groups, including all subdivisions of the substantia nigra and ventral tegmental area, and in the retrorubral field, rostral and caudal linear raphe nuclei, interfascicular nucleus, and supramammillary region. Combined isotopic/nonisotopic double-labeling in situ hybridization demonstrated that virtually all of the tyrosine hydroxylase (the catecholamine biosynthetic enzyme) mRNA-containing neurons in the ventral midbrain also expressed trkB or trkC mRNAs. Additional perikarya within these regions expressed the neurotrophin receptor mRNAs but were not dopaminergic. The present results demonstrate that essentially all mesencephalic dopaminergic neurons synthesize the neurotrophin receptors TrkB and TrkC and thus exhibit the capacity to respond directly to BDNF and NT-3 in the adult midbrain in vivo. Moreover, because BDNF and NT-3 are produced locally by subpopulations of the dopaminergic cells, the present data support the notion that the neurotrophins can influence the dopaminergic neurons through autocrine or paracrine mechanisms.  相似文献   
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In its tissue-specific function as a collagen receptor of chondrocytes, cartilage annexin V (anchorin CII) occupies a key position in the organization of the cell-extracellular matrix (ECM) junction for the tissue. The general role of annexin V (Anx V) in other tissues suggests involvement in cellular secretory processes and in regulation of apoptosis. Immunohistochemical analysis of Anx V in growth plate cartilage, confirmed by in situ hybridization, suggests that Anx V is prominently expressed and forms a major constituent of growth plate chondrocytes. Anx V epitopes are also located in the pericellular matrix of hypertrophic cartilage. In adult articular cartilage the expression is downregulated, with the highest levels of immunostaining found in the upper third of the articular cartilage layers and almost no antigen found in the deep layers. Osteoarthritic (OA) cartilage is characterized by a significant upregulation of message and protein throughout the entire depth of the tissue, an accumulation of cytoplasmic annexin V epitopes, and a release of epitopes into the pericellular and interterritorial matrix, in part co-localized with granular structures. Therefore, Anx V expression and tissue distribution may serve as a histological marker for metabolic alterations and for changes in the cellular phenotype associated with OA.  相似文献   
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The metabolism of the reproductive and developmental toxicant bis(2-methoxyethyl)ether (diglyme) was studied in isolated rat hepatocytes and in the intact rat. Male Sprague-Dawley rats (190-220 g) were used in both studies. Hepatocytes, isolated by a two-step in situ collagenase perfusion of the liver, were cultured as monolayers and incubated with [14C]diglyme at 1, 10, 30, and 50 microM for up to 48 h. For the in vivo study, rats were given single oral doses of [14C]diglyme at 5.1 mmol/kg body wt, and urine was collected for up to 96 h. Radioactive compounds in the culture medium or in the urine were separated by high performance liquid chromatography and quantified with an in-line radioactivity monitor. Metabolites were identified by comparison of their chromatographic retention times and their mass spectra with those of authentic compounds. The principal metabolite from hepatocytes and in the urine was (2-methoxyethoxy)acetic acid (MEAA). This metabolite accounted for approximately 36% of the radioactivity in the 48-h culture medium and about 67% of the administered dose in the 48-h urine. Other prominent metabolites common to both systems included 2-(2-methoxyethoxy)ethanol, methoxyacetic acid (MAA), 2-methoxyethanol, and diglycolic acid. The diglyme metabolite profiles from urine and from hepatocytes were qualitatively similar, demonstrating that, in the rat, hepatocytes serve as a good model system for predicting the urinary metabolites of diglyme. Moreover, MEAA was shown to be the metabolite best suited for use as a short-term biological marker of exposure to diglyme.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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