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排序方式: 共有2643条查询结果,搜索用时 31 毫秒
1.
David Simon Koray Tascilar Sara Unbehend Sara Bayat Andreas Berlin Anna-Maria Liphardt Timo Meinderink Juergen Rech Axel J Hueber Georg Schett Arnd Kleyer 《Journal of bone and mineral research》2020,35(9):1695-1702
The impact of primary hand osteoarthritis (HOA) on bone mass, microstructure, and biomechanics in the affected skeletal regions is largely unknown. HOA patients and healthy controls (HCs) underwent high-resolution peripheral quantitative computed tomography (HR-pQCT). We measured total, trabecular, and cortical volumetric bone mineral densities (vBMDs), microstructural attributes, and performed micro–finite element analysis for bone strength. Failure load and scaled multivariate outcome matrices from distal radius and second metacarpal (MCP2) head measurements were analyzed using multiple linear regression adjusting for age, sex, and functional status and reported as adjusted Z-score differences for total and direct effects. A total of 105 subjects were included (76 HC: 46 women, 30 men; 29 HOA: 23 women, six men). After adjustment, HOA was associated with significant changes in the multivariate outcome matrix from the MCP2 head (p < .001) (explained by an increase in cortical vBMD (Δz = 1.07, p = .02) and reduction in the trabecular vBMD (Δz = −0.07, p = .09). Distal radius analysis did not show an overall effect of HOA; however, there was a gender-study group interaction (p = .044) explained by reduced trabecular vBMD in males (Δz = −1.23, p = .02). HOA was associated with lower failure load (−514 N; 95%CI, −1018 to −9; p = 0.05) apparent in males after adjustment for functional status. HOA is associated with reduced trabecular and increased cortical vBMD in the MCP2 head and a reduction in radial trabecular vBMD and bone strength in males. Further investigations of gender-specific changes of bone architecture in HOA are warranted. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research. 相似文献
2.
To overcome specific absorption rate (SAR) limitations of spin-echo-based MR imaging techniques, especially at (ultra) high fields, rapid acquisition relaxation enhancement/TSE (turbo spin echo)/fast spin echo sequences in combination with constant or variable low flip angles such as hyperechoes and TRAPS (hyperTSE) have been introduced. Due to the multiple spin echo and stimulated echo pathways involved in the signal formation, the contrast behavior of such sequences depends on both T2 and T1 relaxation times. In this work, constant and various variable flip angle sequences were analyzed in a volunteer study. It is demonstrated that a single effective echo time parameter TE(eff) can be calculated that accurately describes the overall T2 weighted image contrast. TE(eff) can be determined by means of the extended phase graph concept and is practically independent of field strength. Using the described formalism, the contrast of any TSE sequence can be predicted. HyperTSE sequences are demonstrated to show a robust and well-defined T2 contrast allowing clinical routine MRI to be performed with SAR reductions of typically at least 70%. 相似文献
3.
Matthias Guckenberger MD Juergen Meyer Juergen Wilbert Kurt Baier Otto Sauer Michael Flentje 《Strahlentherapie und Onkologie》2007,183(6):307-313
PURPOSE: To evaluate the precision of image-guided radiotherapy (IGRT) using cone-beam computed tomography (CB-CT) for volume imaging and a robotic couch for correcting setup errors in six degrees of freedom. PATIENTS AND METHODS: 47 consecutive patients with 372 fractions were classified according to whether a patient fixation device was used (pat(fix): n = 28) or not (pat(non-fix): n = 19). Prior to treatment a CB-CT was acquired and translational and rotational setup errors were corrected online without an action level using a robotic couch (HexaPOD). A second CB-CT was acquired after the correction process and after treatment in 134 and 238 fractions, respectively. RESULTS: In 17 fractions (4.6%) rotational errors > 3 degrees exceeded the motion range of the HexaPOD. Errors (3D vector) after the correction process were significantly smaller for pat(fix) compared to pat(non-fix) (p < 0.001): 0.9 mm +/- 0.5 mm and 1.6 mm +/- 0.8 mm, respectively. For pat(non-fix) the correction of rotational errors resulted in displacements of the patients on the angled couch of 0.6 mm/1 degree. Intrafractional motion further decreased precision in pat(non-fix) but not in pat(fix). CONCLUSION: Very high precision in cranial and extracranial treatment of immobilized patients was demonstrated. Without application of adequate immobilization the correction of rotational errors and intrafractional patient motion significantly decreased the accuracy of the online correction protocol. 相似文献
4.
To support blood supply in the growing field of cancer surgery and to avoid transfusion induced immunomodulation caused by the allogeneic barrier and by blood storage leasions we use intraoperative blood salvage with blood irradiation. This method is safe as it provides efficient elimination of contaminating cancer cells, and as it does not compromise the quality of RBC. According to our experience with more than 700 procedures the combination of blood salvage with blood irradiation also is very effective in saving blood resources. With this autologous, fresh, washed RBC a blood product of excellent quality is available for optimal hemotherapy in cancer patients. 相似文献
5.
Philipp Schlatter Heike Gutmann Juergen Drewe 《European journal of pharmaceutical sciences》2006,28(1-2):141-154
BACKGROUND: Kidney proximal tubular cells play a major role in the transport of endogenous and exogenous compounds. A multitude of different transporters are expressed starting with multidrug ABC transporters (e.g. abcb1, abcc1-6), slc22a6-8 (organic anion transporters) and slc22a1-3 (organic cation transporters). For transport studies of renal drug transport, cell lines like MDCK and LLC-PK1 are often used to overexpress and study one or two transporters, such as abcb1 or abcc1-6. However, the use is limited since under physiological conditions xenobiotics are transported through different transporters at the same time. Therefore, a primary in vitro model expressing functionally different transporters simultaneously, as it is the case in vivo, would be of great benefit. METHODS: Primary proximal tubular cells were isolated from porcine kidney. Cells were cultured under selective culturing conditions leading to specific growth of primary proximal tubular cells. Expression of important proximal transporters was checked at mRNA level with RT-PCR, at protein level with immunocytochemistry and functionally by transport and uptake assays. RESULTS: A model of primary proximal tubular cells was established expressing the most important transporters: abcb1, abcc1, abcc2, slc22a8, slco1a2, slc15a1, slc5a2 and slc4a4. In freshly isolated cells, slc22a1 and slc22a6 were expressed, but were down-regulated in culture. Abcb1, abcc1, abcc2 and slc4a4 were detected at protein level with immunostaining. Functional activity was confirmed for abcb1, abcc1/2, slc22a8, slc15a1/2 and slc5a1/2. The tightness of the monolayers of this model was better than in previously established in vitro models. CONCLUSION: This primary cell culture model might be an interesting tool to investigate proximal tubular transport and to predict toxicity and drug interactions since it expresses functionally several transporters simultaneously. 相似文献
6.
7.
Dr. Juergen Pauletzki MD Joseph Holl MD Michael Sackmann MD Michael Neubrand MD Ulrich Klueppelberg MD Tilman Sauerbruch MD Gustav Paumgartner MD 《Digestive diseases and sciences》1995,40(8):1775-1781
To determine the rate and characteristics of gallstone recurrence after direct contact dissolution with methyltert-butyl ether, 60 consecutive patients were followed for up to 4.5 years (median 2.2 years) after complete disappearance of all stone residues and debris and cessation of adjuvant bile acid therapy. Initial gallstones had been multiple in all but four patients. Twenty-eight of the 60 patients developed recurrent gallstones. The cumulative risk of gallstone recurrence (actuarial analysis) was 23±6%, 34±7%, 55±8%, and 70±9% at one, two, three, and four years, respectively. The recurrent stones were usually multiple and small (6±4 mm). Gallstone recurrence was associated with recurrent biliary pain in two patients, one of whom developed acute cholecystitis. Recurrent stones were cleared completely by bile acid medication with or without shock-wave lithotripsy in 61±15% of patients at one year (actuarial analysis). In conclusion, gallstone recurrence after successful contact dissolution of multiple stones with methyltert-butyl ether has to be expected in a high percentage of patients. Most patients, however, remain free of biliary pain during long-term follow-up. 相似文献
8.
An enforced infection control policy in a laboratory will reduce occupational exposure to blood-borne pathogens and other infectious diseases and protect the dental laboratory personnel from exposure to infective disease. An outline of a workable laboratory infection control policy based on "Occupational Exposure to Bloodborne Pathogens" requirements is presented. 相似文献
9.
Increasing evidence has implicated that insulin-like growth factors (IGFs), polypeptides structurally related to proinsulin, are involved in the function and development of the immune system. To probe the relevance of IGF binding protein 2 (IGFBP-2) in T-cell activation and proliferation, we studied the role of IGFBP-2 in anti-CD3 monoclonal antibody (mAb)-activated peripheral blood mononuclear cells (PBMCs). Secretion of IGF-I, IGF-II, and IGFBP-2 by PBMCs from healthy adult donors was determined by radioimmunoassays (RIAs). The PBMC proliferative response after stimulation with anti-CD3 mAb and exposure to increasing concentrations of IGF-I, IGF-II, IGFBP-2, and anti-IGFBP-2 were determined by bromodeoxyuridine enzyme-linked immunosorbent assay. Observations were tested for significance by paired t-tests. We demonstrate an increase in IGFBP-2 secretion associated with both activation of PBMC by anti-CD3 mAb and increasing cell density. Incubation with exogenous IGFBP-2 increased the proliferation of PBMCs, whereas anti-IGFBP-2 had an antiproliferative effect on PBMCs that was reversed by simultaneous exposure to IGFBP-2. The stimulatory activity of IGFBP-2 (1-10 ng/ml) on anti-CD3 mAb-activated PBMCs was similar to that of IGF-I and IGF-II (1-100 ng/ml), with the mean increase in PBMC proliferative response ranging between 150% and 160% for IGFBP-2 (p = 0.03), 150% and 170% for IGF-I (p < 0.01), 133%-161% for IGF-II (p < 0.01), and 157% and 175% for IGF-I + IGF-II (p < 0.01). Thus, our data strongly suggest a role for IGFBP-2 as a local growth factor contributing to the proliferation and activation of mononuclear cells. 相似文献
10.
Automated extraction of genomic DNA from medically important yeast species and filamentous fungi by using the MagNA Pure LC system 总被引:5,自引:0,他引:5
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Loeffler J Schmidt K Hebart H Schumacher U Einsele H 《Journal of clinical microbiology》2002,40(6):2240-2243
A fully automated assay was established for the extraction of DNA from clinically important fungi by using the MagNA Pure LC instrument. The test was evaluated by DNA isolation from 23 species of yeast and filamentous fungi and by extractions (n = 28) of serially diluted Aspergillus fumigatus conidia (10(5) to 0 CFU/ml). Additionally, DNA from 67 clinical specimens was extracted and compared to the manual protocol. The detection limit of the MagNA Pure LC assay of 10 CFU corresponded to the sensitivity when DNA was extracted manually; in 9 of 28 runs, we could achieve a higher sensitivity of 1 CFU/ml blood, which was found to be significant (p 相似文献