277 research outputs found

    Collagen Framework of the Volar Plate of Human Proximal Interphalangeal Joint

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    The functional roles of the three-dimensional fibrillar ultrastructure of the proximal interphalangeal joint volar plates of human fingers were studied by light microscopy and scanning electron microscopy. The results revealed that the volar plate consists of three layers of fibers. The first layer forms an intracavity wall with two parts, the proximal &#34;membranous portion&#34;, and the distal &#34;meniscoid protrusion&#34; that is separated from the middle phalangeal base by a &#34;recess&#34;. The second layer contains the &#34;check ligament&#34;, which lies parallel to the fibers of the tendon, anchors tightly into the middle phalangeal base, and protects the joint from hyperextension. The third layer connects to the fibers from the accessory ligament and ligamentous tendon sheath of the A3 pulley, perpendicularly crosses the fibers of the tendon, becomes the periosteum of the middle phalangeal base, and functions as a hanging support for the volar plate and as a gliding floor for the flexor tendon.</p

    Clinicopathological Analysis of de Quervain's Disease

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    Excised extensor retinacula of the first compartment and tenosynovium from 35 patients (6 men and 29 women) with de Quervain's disease were examined by light and electron microscopy to investigate the pathogenic mechanism. The patients, aged from 22-78 years, averaging 50 years, comprised the study group. Two hundred and thirty-two specimens from cadavers of 95 men and 75 women were macroscopically examined as the control. In the study group, the extensor retinaculum and tenosynovium were macroscopically thickened, and were histologically classified into 4 groups based on presence or absence of septum, and the location of retinacular thickening. Morphologically, the thickening of the tenosynovium and retinaculum was due to fibrosis in every layer, although fibroses were seen mainly in the middle layer. The ratios of proliferation of fibroblasts, myxoid changes and/or hyaline degeneration, and vascular proliferation were varied between layers. Minimal round cell infiltration was found in the retinaculum as well as in the tenosynovium. The results also indicate that the Iwahara-Nozue test can be used to accurately predict relatively greater thickening of the retinaculum on the extensor pollicis brevis side. Based on clinicopathological analyses, it appears that de Quervain's disease is induced not only by extrinsic factors such as superficial friction but also by intrinsic factors.</p

    Evaluation of calibration factor of OSLD toward eye lens exposure dose measurement of medical staff during IVR

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    The eye lens is a sensitive organ of which an x‐ray exposure dose should be managed during interventional radiology (IVR). In the actual situations, the eye lens is exposed to scattered x‐rays; they have different from the standard x‐ray energies which are used for general dose calibration of the dosimeter. To perform precise dose measurement, the energy dependence of the dosimeter should be properly accounted for when calibrating the dosimeter. The vendor supplies a calibration factor using 80‐kV diagnostic x‐rays under a free‐air condition. However, whether it is possible to use this calibration factor to evaluate the air kerma during the evaluation of the eye lens dose is unclear. In this paper, we aim to precisely determine calibration factors, and also examine the possible application of using a vendor‐supplied calibration factor. First, the x‐ray spectrum at the eye lens position during fluoroscopy was measured with a CdTe x‐ray spectrometer. We mimicked transfemoral cardiac catheterization using a human‐type phantom. Second, we evaluated the doses and calibration factors at three dosimetric points: front and back of protective goggles, and the front of the head (eye lens position). We used the measured x‐ray spectrum to determine the incident photon distribution in the eye lens regions, and x‐ray spectra corresponding to the dosimetric points around the eye lens were estimated using Monte Carlo simulation. Although the calibration factors varied with dosimetric positions, we found that the factors obtained were similar to the vendor‐supplied calibration factor. Furthermore, based on the experiment, we propose a practical way to calibrate an OSL dosimeter in an actual clinical situation. A person evaluating doses can use a vendor‐supplied calibration factor without any corrections for energy dependences, only when they add a systematic uncertainty of 5%. This evidence will strongly support actual exposure dose measurement during a clinical study

    Computer simulation analysis of fracture dislocation of the proximal interphalangeal joint using the finite element method.

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    Stress is a proximal interphalangeal (PIP) joint model was analyzed by the two-dimensional and three-dimensional finite element methods (FEM) to study the onset mechanisms of the middle phalangeal base fracture. The structural shapes were obtained from sagittally sectioned specimens of the PIP joint for making FEM models. In those models, four different material properties were given corresponding to cortical bone, subchondral bone, cancellous bone and cartilage. Loading conditions were determined by estimating the amount and position of axial pressure added to the middle phalanx. A general finite element program (MARC) was used for computer simulation analysis. The results of the fracture experiments compared with the clinical manifestation of the fractures justify the applicability of the computer simulation models using FEM analysis. The stress distribution changed as the angle of the PIP joint changed. Concentrated stress was found on the volar side of the middle phalangeal base in the hyperextension position, and was found on the dorsal side in the flexion position. In the neutral position, the stress was found on both sides. Axial stress on the middle phalanx causes three different types of fractures (volar, dorsal and both) depending upon the angle of the PIP joint. These results demonstrate that the type of PIP joint fracture dislocation depends on the angle of the joint at the time of injury. The finite element method is one of the most useful methods for analyzing the onset mechanism of fractures.</p

    The Usefulness of C-arm CBCT-guided Abscess Drainage with A Flat-panel Detector

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    Herein we report our experience with a C-arm cone beam computed tomography (CBCT)-guided abscess drainage procedure. We retrospectively examined the medical records and imaging results of patients whose abscesses were drained between 2005 and 2010 employing this system. We analyzed the technical success rate and incidence of procedure-related complications. Percutaneous abscess drainage using C-arm CBCT was performed using a flat-panel detector digital subtraction angiography (DSA) system on 104 lesions in 97 patients (55 men, 42 women) with a mean age of 64.7 (30-88) years. The drainage procedure was performed twice in 6 patients and 3 times in 2 patients, and 6 patients received 2 or more punctures at the same time. The technical success rate with this procedure was 98.1% (102 of 104 lesions). Placement of the drainage tube was abandoned in 2 patients due to difficulty in inserting a wire into the abscess cavity in 1 case and difficulty looping the wire in the other. The incidence of procedure-related complications was 3.85% (4 of 104 lesions). Our retrospective study and review of the relevant literature revealed that the C-arm CBCT-guided abscess drainage procedure examined was generally safe for patient use, showed a high technical success rate and low incidence of procedure-related complications, and was useful for abscesses that were inaccessible using other instruments. Although C-arm CBCT has limited contrast resolution, this disadvantage is easily overcome by comparing images with those obtained using other modalities

    Expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and its related extracellular matrix degrading enzymes in the endometrium during estrous cycle and early gestation in cattle

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    <p>Abstract</p> <p>Background</p> <p>Extracellular matrix metalloproteinase inducer (EMMPRIN) regulates several biological functions involving the modulation of cell behaviors via cell-cell and cell-matrix interactions. According to its diverse functions, we hypothesized that EMMPRIN may play an important role in endometrial remodeling and establishment of pregnancy in cow.</p> <p>Methods</p> <p>In this study, endometrial tissues from the cyclic cows during before ovulation, after ovulation and middle of estrous cycle; and pregnant endometrial tissues from Day 19 to 35 of gestation have been used. Expression of mRNA was analyzed by RT-PCR, qPCR and in situ hybridization whereas protein expression by immunohistochemistry and western blot analysis.</p> <p>Results</p> <p>EMMPRIN mRNA was expressed in both cyclic and pregnant endometrium and significantly higher in the endometrium at Day 35 of gestation than the cyclic endometrium. In Western blot analysis, an approximately 65 kDa band was detected in the endometrium, and approximately 51 kDa in the cultured bovine epithelial cells and BT-1 cells, respectively. Both in situ hybridization and immunohistochemistry data showed that EMMPRIN was primarily expressed in luminal and glandular epithelium with strong staining on Day 19 conceptus. At Day 19 of gestation, expression of EMMPRIN mRNA on luminal epithelium was decreased than that observed at middle of estrous cycle, however, on Day 30 of gestation, slightly increased expression was found at the site of placentation. Expression of matrix metalloproteinase-2 (MMP-2) and MMP-14 mRNA were mainly detected in stroma and their expression also decreased at Day 19 of gestation however it was also expressed at the site of placentation at Day 30 of gestation as observed for EMMPRIN. Expression of MMP-1 or -9 mRNA was very low and was below the detection limit in the cyclic and pregnant endometrium.</p> <p>Conclusion</p> <p>EMMPRIN from the luminal epithelium may regulate the expression of stromal MMP-2 and -14 suggesting its crucial role in adhesion and fusion of embryo to luminal epithelium by directly itself through physiological tissues remodeling and developmental process, and/or stimulating MMPs to compensate endometrial functions.</p

    Relationship between the cAMP levels in leukocytes and the cytokine balance in patients surviving gram negative bacterial pneumonia

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    Lipopolysaccharide-stimulated leukocytes secrete proinflammatory cytokines including tumor necrosis factor-α and interleukin-12. Over-activation of host defense systems may result in severe tissue damage and requires regulation. Granulocyte colony-stimulating factor and interleukin-10 are candidate cytokines for inducing tolerance to lipopolysaccharide re-stimulation. We compared cytokines secreted by lipopolysaccharide-stimulated blood cells from patients who had survived gram negative bacterial pneumonia (Pseudomonas aeruginosa, Escherichia coli or Proteus mirabilis, n = 26) and age-matched healthy volunteers (n = 18). Interleukin-12p70 and tumor necrosis factor-α expression was significantly lower in patients (p = 0.0039 and p<0.001) compared to healthy controls, while granulocyte colony-stimulating factor production was markedly higher in patients (p<0.001). Levels of interleukin-10 were comparable. Granulocyte colony-stimulating factor expression was inversely correlated with interleukin-12p70 (R = −0.71, p<0.001) and tumor necrosis factor-α (R = −0.64, p<0.001) expression; interleukin-10 showed no significant correlation. In unstimulated leukocytes from patients, cAMP levels were significantly raised (p = 0.020) and were correlated inversely with interleukin-12p70 levels (R = −0.81, p<0.001) and directly with granulocyte colony-stimulating factor (R = 0.72, p = 0.0020), matrix metalloproteinase-9 (R = 0.67, p = 0.0067) and interleukin-10 (R = 0.54, p = 0.039) levels. Our results demonstrate that granulocyte colony-stimulating factor production by lipopolysaccharide-stimulated leukocytes is a useful indicator of tolerance induction in surviving pneumonia patients and that measuring cAMP in freshly isolated leukocytes may also be clinically significant
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