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Objective To: observe CT and MRI features of endometrial stromal sarcoma (ESS). Methods: Plain and enhanced imaging data, including CT (n=5) and MRI (n=6) of 11 patients with ESS confirmed by postoperative pathology were analyzed retrospectively. Results: There were 9 cases of singe low-grade ESS and 2 cases of single undifferentiated sarcoma. The lesions located in the uterine cavity in 7 cases, in the myometrium in 4 cases, manifested as circular masses in 8 cases and as irregular masses in 3 cases. The mean maximum diameter of lesions was (9.18±1.36)cm. The boundaries of lesions were clear in 4 cases and unclear in 7 cases. Based on CT and MRI findings, there were 4 patients with solid masses, 6 patients with solid-cystic masses and 1 case with cystic mass. Solid component of lesions manifested as iso- or hypo-attenuation compared with myometrium on plain CT images in 5 patients, including 4 cases with nonuniform density lesions and 1 case with uniform density lesion. MRI showed signal reducing on ADC images in 6 patients. Among them, lesions in 5 cases manifested as iso- or hypo-signal on T1WI, hyper-signal or slightly high signal on T2WI, and slightly high signal on DWI, lesion in another case (cystic mass) manifested as hyper-signal on T1WI, high signal on T2WI and high signal in central area of lesion on DWI. Incremental and continuous enhancement were found in 10 cases, while no enhancement was found in the rest one case (cystic mass). Cystic and necrosis changes were found in 8 cases, and invasions of deep layer myometrium were found in 6 cases. Some of the patients had complications, including adenomyosis in 2 cases, uterine fibroid in 5 cases, pelvic effusion in 5 cases, intrauterine hemorrhage in 1 case and salpingian dropsy in 2 cases. Conclusion: ESS has characteristic CT and MRI findings, which can provide useful references for diagnosis.
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Objective:To explore MRI findings and clinical characteristics of adnexal torsion (AT) in pregnancy. Methods: Clinical and MRI data of 14 patients in pregnancy with pathologically confirmed AT were retrospectively analyzed. Results: There were 2 cases of primary AT and 12 cases of secondary AT (5 with ovarian cyst, 4 with ovarian teratoma, 2 with hydrosalpinx and 1 with tubal mesothelial cyst). AT occurred on the right side in 5 cases and on the left in 9 cases, with torsion angles ranged from 180° to 1 720°. MRI showed that except for 3 cases of solitary AT, ovarian enlargement occurred in 11 cases. Mass in pelvic or abdominal cavity was found in 12 cases, including 8 cystic masses and 4 cystic solid masses. The torsional pedicle next to the masses presented typical "beak sign" in 6 cases, while 1 case showed whirlpool sign, all showed mixed high signal in DWI. Adnexal hemorrhage was noticed in 6 cases and pelvic effusion in 8 cases. The pregnancy outcome was 6 full-term healthy fetuses and 8 preterm infants. Conclusion: MRI findings of AT in pregnancy have certain characteristics, which are helpful to diagnosis of AT combined with clinical manifestations.
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Some single-use medical devices are reprocessed and reused in some countries in the world, but the regulatory approach is different, and in some countries it isn't regulated yet. In this article, the regulatory status quo of single-use medical devices is reviewed. The regulatory development, important regulatory documents and regulatory approaches of single-use medical device reprocessing in the United States, Germany and the UK are introduced. And how to perform scientific risk assessment and effective risk control is discussed. The information is useful to establish China-specific regulations, and to develop relevant standards, guidelines or specifications and the risk control strategies.
Subject(s)
China , Equipment Reuse , Equipment Safety , Equipment and Supplies , Risk Assessment , United StatesABSTRACT
The reuse of high-cost single-use medical devices (SUD) is permitted in many countries, such as the United States, Germany and the United Kingdom, but strict regulatory requirements must be met. In addition to regulatory policies and regulations, such as market access mode and special requirements on Good Manufacture Practice (GMP), there are strict technical requirements on the potential risk control and quality assurance system. Therefore, effective risk assessment and risk control technology are the keys to ensure effective quality control and safe use of SUDs. In this article, based on analyzing the technological requirements of the national regulatory on SUDs in the United States, Germany and Britain, and combined with the review from latest relevant literature, to discuss the strategies of how to carry out scientific risk assessment. Some risk control technologies on the reuse of SUDs are introduced, which will provide support for the further study on risk control strategies and regulatory decisions for the reuse of SUDs in China.
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A rapid, sensitive and simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of clevidipine butyrate and its primary metabolite clevidipine acid in dog blood. After one-step protein precipitation with methanol, the chromatographic separation was carried out on an Ecosil C18 column (150 mm x 4.6 mm, 5 µm) with a gradient mobile phase consisting of methanol and 5 mmol · L(-1) ammonium formate. A chromatographic total run time of 13.0 min was achieved. The quantitation analysis was performed using multiple reaction monitoring (MRM) at the specific ion transitions of m/z 454.1 [M-H]- --> m/z 234.1 for clevidipine butyrate, m/z 354.0 [M-H]- --> m/z 208.0 for clevidipine acid and m/z 256.1 [M-H]- --> m/z 227.1 for elofesalamide (internal standard, IS) in the negative ion mode with electrospray ionization (ESI) source. The linear calibration curves for clevidipine butyrate and clevidipine acid were obtained in the concentration ranges of 0.5-100 ng · mL and 1-200 ng · mL(-1), separately. The lower limit of quantification of clevidipine butyrate and clevidipine acid were 0.5 ng · mL(-1) and 1 ng · mL(-1). The intra and inter-assay precisions were all below 12.9%, the accuracies were all in standard ranges. Stability testing indicated that clevidipine butyrate and clevidipine acid in dog blood with the addition of denaturant methanol was stable under various processing and/or handling conditions. The validated method has been successfully applied to a pharmacokinetic study of clevidipine butyrate injection to 8 healthy Beagle dogs following intravenous infusion at a flow rate of 5 mg · h(-1) for 0.5 h.