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排序方式: 共有496条查询结果,搜索用时 15 毫秒
1.
Yicheng Chen Ozan Genc Clare B. Poynton Suchandrima Banerjee Christopher P. Hess Janine M. Lupo 《NMR in biomedicine》2022,35(5):e4666
Quantitative susceptibility mapping (QSM) has the potential for being a biomarker for various diseases because of its ability to measure tissue susceptibility related to iron deposition, myelin, and hemorrhage from the phase signal of a T2*-weighted MRI. Despite its promise as a quantitative marker, QSM is faced with many challenges, including its dependence on preprocessing of the raw phase data, the relatively weak tissue signal, and the inherently ill posed relationship between the magnetic dipole and measured phase. The goal of this study was to evaluate the effects of background field removal and dipole inversion algorithms on noise characteristics, image uniformity, and structural contrast for cerebral microbleed (CMB) quantification at both 3T and 7T. We selected four widely used background phase removal and five dipole field inversion algorithms for QSM and applied them to volunteers and patients with CMBs, who were scanned at two different field strengths, with ground truth QSM reference calculated using multiple orientation scans. 7T MRI provided QSM images with lower noise than did 3T MRI. QSIP and VSHARP + iLSQR achieved the highest white matter homogeneity and vein contrast, with QSIP also providing the highest CMB contrast. Compared with ground truth COSMOS QSM images, overall good correlations between susceptibility values of dipole inversion algorithms and the COSMOS reference were observed in basal ganglia regions, with VSHARP + iLSQR achieving the susceptibility values most similar to COSMOS across all regions. This study can provide guidance for selecting the most appropriate QSM processing pipeline based on the application of interest and scanner field strength. 相似文献
2.
Yasar Pazir Tolga Eroglu Ayse Kose Taha Burak Bulut Cihat Genc Mustafa Kadihasanoglu 《Andrologia》2021,53(9):e14157
In this prospective study, we investigated the impact of SARS-CoV-2 infection on semen parameters in a cohort of men who had recently recovered from COVID-19. A total of 24 men who had recently recovered from mild COVID-19 were included in the study. Their semen parameters were normal before COVID-19 according to the World Health Organization 2010 reference values. Semen samples were collected from these participants in the recovery phases of COVID-19. To determine the effect of SARS-CoV-2 infection on semen parameters, the patients' pre-COVID-19 and post-COVID-19 semen analyses were compared. The mean age of the participants was 34.7 ± 6.4 years. The median interval between the positive nasopharyngeal swab test and obtaining semen samples was 111.5 (158) days. There was no significant difference in semen parameters before and after COVID-19 in terms of semen volume (p = .56), sperm concentration (p = .06), and progressive motility (p = .14). Total motility (p = .01) and total motile sperm count (p = .02) decreased significantly after SARS-CoV-2 infection compared to the pre-infection values. This study demonstrated that sperm motility and total motile sperm count were the semen parameters which showed a significant reduction in cases with a history of mild COVID-19. 相似文献
3.
4.
R. Uygur M. Yagmurca O. A. Alkoc A. Genc A. Songur K. Ucok O. A. Ozen 《Andrologia》2014,46(4):356-369
The aim of this study was to investigate the effects of quercetin and fish n‐3 fatty acids on the changes in testis induced by ethanol. Forty‐five rats divided into five groups, control, ethanol, ethanol+quercetin, ethanol+fish n‐3 fatty acids and ethanol+quercetin+fish n‐3 fatty acids. At the end of 8 weeks, all the rats were sacrificed. Degenerative changes in histopathological analyses, the decreased body weight gain and seminiferous tubule diameters in ethanol group have been observed. TUNEL assay also showed an increase in apoptotic cell number. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH‐Px), xanthine oxidase (XO) and testosterone levels were decreased as well as the levels of malondialdehyde (MDA) and nitric oxide (NO) were increased in ethanol group. Histopathological changes caused by ethanol have been improved by quercetin and fish n‐3 fatty acids. It was also found that protection was provided by increasing SOD, CAT and GSH‐Px activities in groups administered quercetin, fish n‐3 fatty acids and quercetin+fish n‐3 fatty acids, and by decreasing the levels of MDA and NO in groups administered both quercetin and fish n‐3 fatty acids together. These results suggest that quercetin and fish n‐3 fatty acids are beneficial agents to reduce testicular injury induced by ethanol except for testosterone levels. 相似文献
5.
Cisplatin is a chemotherapeutic agent, which is used in the treatment of various solid organ cancers, and its main dose limiting side effect of cisplatin is nephrotoxicity. The aim of this study is to investigate the role of pioglitazone and creatine on cisplatin nephrotoxicity in vitro. Real-time cell analyzer system (RTCA) was used for real-time and time-dependent analysis of the cellular response of HK-2 cells following incubation with cisplatin and combination with creatine or pioglitazone hydrochloride. First, half-maximal inhibitory concentrations (IC50) of cisplatin, creatine and pioglitazone were calculated by RTCA system. Afterwards creatine and pioglitazone was administered with serial dilutions under RTCA system. IC50 dose for cisplatin was 7.69?M?×?10?5 at 24th hour and 3.93?M?×?10?6 at 48th hour. IC50 dose for pioglitazone was 1.61?M?×?10?3 at 24th hour and 2.85?M?×?10?4 at 48th hour. Although cells were treated the dose of 40,225?mM creatine, IC50 dose could not been reached. Neither pioglitazone nor creatine had additional protective effect in any dose. Consequently, beneficial effect of creatine and pioglitazone on cisplatin-induced cell death could not be found. Further studies and clinical trials are needed to evaluate the effect of different doses of these drugs in cisplatin-induced nephrotoxicity. 相似文献
6.
Leyla Guler Murat Tavlasoglu Orhan Yucel Adem Guler Mehmet Ali Sahin Mustafa Kurkluoglu Yusuf Sirin Ayse Eken Mehmet Gamsizkan Mehmet Dakak Sedat Gurkok Onur Genc 《Journal of anesthesia》2014,28(3):347-353
Purpose
Taurine, the major intracellular free amino acid found in high concentrations in mammalian cells, is known to be an endogenous antioxidant and a membrane-stabilizing agent. It was hypothesized that taurine may be effective in reducing ischemia–reperfusion injury after lung transplantation and an experimental study was conducted in a rat model.Methods
The number of Sprague–Dawley rats used in the study was 35. Animals were randomized into five groups of 7 rats each, including control, donor I, donor II, ischemia–reperfusion injury, and treatment groups. All animals were exposed to the same experimental conditions in the preoperative period. Rats were fixed in a supine position after the induction. After the rats were shaved, a left pneumonectomy was performed following sternotomy in control, donor I, and donor II groups. The harvested grafts in donor I and donor II groups were transplanted to the rats of the ischemia–reperfusion group and treatment group, respectively. However, taurine was administered intraperitoneally for 3 days before the harvesting procedure in donor II. All harvested lungs were kept in a Euro-Collins solution at +4 °C for 24 h in a half-inflated manner. After harvesting and transplantation, lungs were sampled for histopathological and biochemical analysis.Results
Malondialdehyde and superoxide dismutase, glutathione peroxidase, and catalase levels were lower in the treatment group than the other groups (p < 0.05). Histopathological findings were better in treatment group than the ischemia–reperfusion group (p < 0.05).Conclusion
It was demonstrated that donor treatment with taurine resulted in preservation of transplanted lung tissue in respect to histopathological and biochemical findings. 相似文献7.
Ozan Ozkaya Hulya Nalcacioglu Demet Tekcan Gurkan Genc Bilge Can Meydan B. Handan Ozdemir M. Kemal Baysal Hasan Tahsin Keceligil 《Pediatric nephrology (Berlin, Germany)》2014,29(7):1283-1287
Background
Dense deposit disease (DDD) (also known as membranoproliferative glomerulonephritis type II) in childhood is a rare glomerulonephritis with frequent progression to end-stage renal disease (ESRD) and a high recurrence after kidney transplantation. The pathophysiologic basis of DDD is associated with the uncontrolled systemic activation of the alternative pathway (AP) of the complement cascade.Case-diagnosis/treatment
A 14-year-old girl presented with edema and nephrotic range proteinuria. Blood tests showed hypoalbuminemia, nephrotic range proteinuria, normal renal function, and a low C3 level. Renal biopsy confirmed the diagnosis of crescentic DDD. Complement analysis revealed strong AP activation (low C3), positive C3 nephritic factor (C3NeF), and a decreased complement factor H (CFH) levels with CFH polymorphisms. Therapy with eculizumab was considered after the failure of corticosteroid and plasmapheresis to modulate the ongoing massive proteinuria and persistence of low serum C3 levels. There was a marked clinical and biochemical response following the administration of eculizumab.Conclusions
Our case emphasizes the efficacy of eculizumab in the management of crescentic DDD in a patient with a normal renal function, in a short follow-up period. Considering previously reported cases, it appears that eculizumab represents a promising new approach which may prevent progression to ESRD in a subset of patients with DDD. 相似文献8.
9.
Nafiye Urganci Merve Usta Derya Kalyoncu Emirzad Demirel 《Indian journal of pediatrics》2014,81(7):675-679