Objective:To establish a high performance size-exclusion chromatography ( HPSEC) method for the determination of impurities including polymers in latamoxef sodium. Methods:The analysis was performed on a Zenix SEC-150 column(7. 8 mm × 300 mm, 3 μm)with the mobile phase of 0. 005 mol·L-1 phosphate buffer solution [0. 005 mol·L-1 disodium hydrogen phosphate-0. 005 mol·L-1 sodium dihydrogen phosphate (61∶39), pH 7. 0] at a flow rate of 0. 8 ml·min-1. The detection wavelength was set at 254 nm. The column tempretrue was 25℃ and the injection volume was 10μl. Results:The impurities including polymers in latamoxef so-dium were completely separated from latamoxef. The linear range of latamoxef was 0. 98-97. 73 μg·ml-1(r=0. 999 9). The limit of quantitation of latamoxef was 2. 9 ng, and the detection limit was 1. 0 ng. The linear range of the total impurities was 0. 45-2. 8 mg· ml-1(r=0. 999 5). Conclusion: The established method is accurate, rapid and reproducible, and suitable for the determination of impurities including polymers in latamoxef sodium.

Objective To analyze the stroke subtypes and influencing factors in four largest economic regions of China.Methods We analyzed the investigation data of QUEST(Quality Evaluation of Stroke Care and Treatment)study conducted in 2006 which included 62 hospitals in a national scale.According to the concept of four economic regions designed by the Development Research Center of the State Council,we performed the univariate and multivariate analysis for the stroke subtypes and its related risk factors in the different economic regions.Results There were 3362(73.5％)ischemic stroke patients and 1214(26.5％)hemorrhagic stroke patients among the total 4576 first-ever stroke patients.Comparison of stroke subtypes in the four different economic regions was statistically significant(P ＜ 0.001),with a percentage of 80.8％ ischemic stroke patients in the northeastern region,78.9％ in the eastern region,68.3％ in the central region and 67.0％ in the western region.The comparisons of risk factors such as history of hypertension,diabetes,hyperlipidaemia,coronary artery event,atrial fibrillation,and overweight in the four different economic regions were also statistically significant(P ＜0.05).Conclusions The subtypes of first-ever stroke vary in the four largest economic regions with a highest proportion of ischemic stroke in the northeastern region and relatively high proportion of hemorrhagic stroke in the central and western economic regions.There are also discrepancies of stroke risk factors in the different economic regions.

Objective To evaluate whether therapeutic ultrasound, applied alone or with urokinase, may have a thrombolytic effect on blood clots in vitro, and the other factors influencing the urokinase-mediated thrombolysis. Methods Experiments were carried out in an in vitro blood clot model.The blood clots were divided into four groups as physiological solution group(NS), urokinase group(UK),physiological solution plus ultrasound group(NS + US), urokinase group plus ultrasound group(UK + US).After intervention of one hour in static 37 ℃ water bath, each group of blood clots was weighed. After that,the weight loss and thrombolysis rate of the blood clots in each group were calculated. To observe the impact of the age of the blood clots on urokinase-mediated thrombolysis rate, the thrombolysis rate of eight time points 3, 4, 5, 6, 7, 8, 9, 10 hours was tested. The time was determined from the blood drawn from the body to the initiation of thrombolysis test. Results In terms of thrombolysis rate, there was significant difference between UK group and UK + US group(LSD-t 12. 1, P ＜ 0.01), with a thrombolysis rate 29. 3% ±8. 2% and 37. 5% ±7. 9%, respectively. However, the difference of thrombolysis rate between NS group and NS + US group with a thrombolysis rate 13. 4% ±4. 4% and 14. 5% ± 5.4%, respectively,was not statistically significant with a P value of 0. 08(LSD-t 1.8). The age of the blood clots had a negative correlation to the thrombolysis rate to some extent. Conclusion Therapeutic ultrasound has a significant effect on thrombolysis in combination with urokinase rather than used alone. To a certain extent,the thrombolysis rate decreases with the age of blood clot.

Objective The aim of this study was to establish a reasonable protocol for a rat model of ferric chloride-induced carotid arterial thrombosis by ultrasonic continuous evaluation.Methods Twenty SD rats were randomly divided into four groups and then treated with 20％,30％,40％ or 50％ concentrations of FeCl3,respectively.The vascular conditions were evaluated by 14L ultrasonic probe,at 10 mins,15 mins,and 20 mins.We then selected the best group through the examination of the rate of spontaneous reperfusion of blood vessels and the rate of reperfusion after intravenous injection of urokinase.At the end of the experiment,vessels were fixed in 10％ formalin solution and stained with HE.Results After external application of FeCl3 on rat common carotid artery for 20 mins,the artery occlusion rate was 100％,20％,0％ and 0％ in animals receiving 50％,40％,30％ and 20％ FeCl3,respectively.After external application of FeCl3 on rat common carotid artery for 120 mins,the spontaneous revascularization rate was 0％ in 50％ concentration group whereas were 100％ in rest other groups (P＜ 0.001).In 50％ concentration group,the partial recanalization rate was 40％ after intravenous injection of urokinase.HE staining revealed that the thrombus was dense and the lumen was partially recanalized after the urokinase intervention in 50％ concentration group.Conclusion By use of uultrasonic continuous evaluation of ferric chloride-induced thrombosis of rat common carotid artery,we have demonstrated that external application of 50％ ferric chloride solution for 20 mins is effective for the formation of thrombus model,which may be suitable for the studv of thrombolysis.

Objective To explore the diagnostic feasibility of Alzheimer disease (AD) associated CSF biomarker (CSF Aβ42, T-tau, and P-tau181) through establishing the cutoff value and the sensitivity and specificity of each biomarker. Methods Seventeen AD dementia patients were enrolled from Peking university first hospital during 2015 July and 2017 Feb including 5 patients that received PET scan using Pittsburgh compound-B. Forty-nine cognitive normal subjects were also enrolled as controls according to the protocol. The levels of Aβ42, T-tau, P-tau181 and the ratio of Aβ42/T-tau、Aβ42/ P-tau181 from all participants were assessed using the innotest-ELISA methods and cutoff value,sensitivity as well as specificity of each biomarker were determined according to the ROC curve. Results There were significant differences in all biomarkers between the cognitive normal controls group and AD dementia group. The cutoff value of Aβ42, T-tau, P-tau181, Aβ42/T-tau and Aβ42/ P-tau181 were 511 ng/mL, 322 ng/mL, 63 ng/mL, 14.72 and 1.74. The sensitivity were 64.7% in Aβ42, 88.2% in T-tau, 58.8% in P-tau181, 82.35% in Aβ42/T-tau and 76.47% in Aβ42/ P-tau181, respectively. The specificity were 97.05% in Aβ42, 75.5% in T-tau, 93.87% in P-tau181, 95.51 % in Aβ42/T-tau and 93.87% in Aβ42/P-tau181, respectively. Conclusion Alzheimer disease associated biomarkers (CSF Aβ42,T-tau, and P-tau181) can distinguish the cognitive normal subjects from AD dementia patients. The methods are reliable and the sensitivity as well as specificity of each biomarker are good which are close to the values reported in the literatures. Thus, this methodology is worth being promoted in the clinic.

Non-bifurcating cervical carotid artery(NBCCA)is a very rare anatomical variation of the cervical carotid artery,which may be related to the abnormal development of internal carotid artery(ICA)and external carotid artery in embryonic period.Neither carotid bulb nor a true carotid bifurcation can be observed on the ultrasound of carotid artery while a"stump-like"change was showed at the expected bifurcation level of carotid artery on DSA.Few cases has been reported in China and abroad so far.This article reported a middle-aged male with a history of hypertension and type 2 diabetes and was admitted to the hospital due to dizziness for one month.The left NBCCA accompanied with severe stenosis of the right ICA was confirmed by cerebral angiography.The patient received the right ICA stent implantation surgery as well as antihypertensive and glucose-control treatment and was discharged as his symptoms improved.Clinical data of this case and related literatures were reviewed,in order to improve clinicians'especially imaging diagnostic physicians'understanding on NBCCA to avoid misdiagnosis and related complications.

Hypereosinophilia (HE) is a kind of hematology disorder affecting multiple organs. Multiple studies demonstrated that HE was correlated with ischemic stroke, and it could be a rare and reversible cause for ischemic stroke. Therefore, more and more concerns have been concentrated by neurologists in recent years. Based on the research data, the definition, typical characteristics, possible mechanism, diagnosis and treatment principles of HE related ischemic stroke were summarized systematically, in order to provide possible personalized treatment strategies for this disease.

Objective:To study positive rates and typing of oligoclonal bands (OCB) in patients with neurological disorders, and to reveal the clinical significance and applicational value of OCB test.Methods:A retrospective analysis was performed on the detection results of 3 217 patients with neurological disorders who undertook both serum and cerebrospinal fluid OCBs in the First Hospital of Peking University from January 2012 to August 2022. According to the final diagnosis, the patients were divided into 13 groups including multiple sclerosis (479 cases), neuromyelitis optica spectrum disorders (935 cases), autoimmune encephalitis (192 cases), viral encephalitis (94 cases), nervous system complication after HSCT (232 cases), Guillain-Barré syndrome (644 cases), chronic inflammatory demyelinating polyneuropathy (157 cases), etc. Cerebrospinal fluid and serum OCBs were detected using isoelectric focusing electrophoresis combining immunofixation, then classified into Ⅰ-Ⅴ types according to the morphology. Consequently, positive rates and types were analyzed for each group. χ2 test was used for comparison between groups. Results:The positive rates of cerebrospinal fluid OCB in multiple sclerosis, nervous system complication after hematopoietic stem cell transplantation (HSCT), autoimmune encephalitis, viral encephalitis, neuromyelitis optica spectrum disorders, Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy were respectively 66.8% (320/479), 48.7% (113/232), 46.4%(89/192), 19.1% (18/94), 17.6% (165/935), 9.9% (64/644), 5.1% (8/157). For patients with multiple sclerosis, neuromyelitis optica spectrum disorders, viral encephalitis, and autoimmune encephalitis, Type Ⅱ bands took the majority of cerebrospinal fluid OCB-positive cases with the rates of 94.1% (301/320), 78.7% (70/89), 77.8% (14/18), and 77.6% (128/165) respectively, indicating intrathecal IgG synthesis; for patients with nervous system complication after HSCT, Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy, type Ⅳ bands took the majority of cerebrospinal fluid OCB-positive cases with the rates of 94.7% (107/113), 82.8% (53/64) and 100% (8/8), indicating no obvious intrathecal IgG synthesis. The positive rates of cerebrospinal fluid oligoclonal bands were significantly different among all groups (χ 2=1 268.31, P<0.001). Conclusion:The positive rates of cerebrospinal fluid oligoclonal bands are different among different neurological disorders, in which the positive rate of cerebrospinal fluid OCB is higher with type Ⅱ bands as the majority type in multiple sclerosis, which indicates that the detection and typing of cerebrospinal fluid OCB are helpful for the diagnosis of various neurological diseases, especially for multiple sclerosis.