Objective　To study the role of the structural gene variation of hepatitis C virus(HCV) in the chronicity of HCV infection. Methods　Serum samples from four HCV infection acquired during six-month follow up and four patients with chronic hepatitis C type were obtained. A 1-kb fragment containing the 3' half of core ，completed E1 and 5' half of E2/NS1 was amplified by nested reverse transcription polymerase chain reaction (RT-PCR). For each，30 cloned cDNAs were examined by a method that combined heteroduplex analysis (HAD) and a single-stranded conformational polymorphisim (SSCP)assay to optimize selection of clones with unique gel shift patterns (clonotypes )as a measure of the quasispecies complexity. Results　There was obvious difference between the SSCP bands of cloned cDNAs representing core-E1 and E2 region，but more distinct difference between heteroduplex and the homoduplex of clones spanning E2 region which accurately reflected the degree of heterogeneity. Quasispecies complexity was higher in those with persistent viremia than those with acute viremia. Conclusion　HCV persistence is associated with complex quasispecies in viral structural region.

Large artery intracranial occlusive disease is a important and common vascular lesion type.It is closcly associated with the onset and recurrence of ischemic stroke; however,at present there are many inadequacies in the study of its etiology and treatment.This article mainly reviews the understanding process of the large artery intracranial occlusive disease,present research results and problems need to be solved.

OBJECTIVE　To evaluate the availability and safety of a new carbapenem meropenem.METHODS　The randomized study was conducted in 60 patients with respiratory tract infections.They were divided into two groups:meropenem or imipenem/cilastatin.RESULTS　The cure rate,effective rate and bacterial clearance rate for meropenem were 80.0%,93.3%,92.3%,respectively and for those of imipenem/cilastatin were 76.7%,90.0% and 91.3%,respectively.The rate of adverse reactions for both meropenem/cilastatin was 3.3%.CONCLUSION　Meropenem appeared to be a highly effective and safe agent in treatment of respiratory tract infections.Its efficacy and safety are similar to that of imipenem/cilastatin.

Objective: To analyze Chinese elderly health policy documents from 2018 to 2022 based on policy tools, so as to provide insights into improving elderly health policies and promoting healthy aging. Methods: Elderly health policy documents were retrieved from “the magic weapon of Peking University”, the policy document database of the State Council and portal websites of relevant ministries and commissions using keywords “elderly”, “aging” and “elderly health”. The documents were encoded using content analysis and keywords were extracted. A two-dimensional analysis framework was constructed based on Rothwell and Zegveld's classification framework and dimension theory, and the use of policy tools was analyzed. Results: Totally 57 Chinese elderly health policy documents were collected from 2018 to 2022, including 44 notices, 7 opinions, one rule, one regulation, one law, one announcement, one letter and one joint declaration. There were 37 documents (64.91%) issued by National Health Commission and its departments and offices. The high-frequency keywords in the documents included “medical and healthcare institutions”, “elderly health”, “rehabilitation/nursing”, “community/grassroots/rural”, “pilot”, “traditional Chinese medicine”, “propaganda” and “standardization”. There were 413 document codes, and the supply-, environment- and demand-side policy tools accounted for 52.54%, 31.72% and 15.74%, respectively. Public health and medical services (19.61%) and science popularization (7.99%) were the most commonly used supply-side policy tools, law/regulations and administration systems (7.99%) was the most commonly used environment-side policy tools, while pilot/demonstration projects (5.33%) was the most commonly used demand-side policy tools. The external and internal indicators of the system dimensions accounted for 48.18% and 51.82%, and political system (17.19%) and technical system (16.46%) were the two most commonly used external indicators, while service system (35.60%) was the most commonly used internal indicator. Conclusions Chinese elderly health policies focused on supply-side policies from 2018 to 2022, such as public health and medical services. The use of demand-side policy tools is recommended to be increased and the internal composition of supply- and environment-side policy tools are recommended to be optimized.

Diabetes mellitus is an independent risk factor for ischemic stroke. Epidemi-ological studies have shown that intensive glucose control can reduce stroke risks in patients with type 2 diabetes. However, the current prospective clinical trials have failed to validate a definite causal relationship between them. This article reviews the clinical trials about the roles of intensive glucose control in patients with type 2 diabetes in the primary and secondary prevention of stroke.

Hypertension is an indep endent risk factor for stroke.Blood pressure variability is the result of the overall balance of in vivo dynamic regulation of the neuroendocrine system It is one of the essential characters of blood pressure.It is associated with the effects of the sensitivity of baroreceptor,physical activity,diseases and other factors.Blood pressure variability is closely associated with the target organ damage.An increasing number of studies have shown that blood pressure variability plays an important role in the occurrence and prognosis of stroke.It has a profound significance in the prevention and treatment of stroke.

Transient ischemic attack (TIA) is a common acute ischemic cerebrovascular disease.It is a risk warning sign and needs to be evaluated and treated urgently.This article reviews the development history of the definition of TIA and its evolution,and TIA prognostic rating scale in order to conduct a comprehensive evaluation,risk stratification and appropriate treatment in patients with TIA,thereby reducing the risk of stroke after TIA.

Limb rehabilitation is one of the key issues for improving the quality of life in patients with stroke. Studies have demonstrated that the retention and recovery of active movement of hemiplegic limb have predictive value for the prognosis in acute stroke. The responsible lesion sites and rehabilitation training in the acute phase may be an important factor in influencing the recovery of active movement ability of hemiplegie upper limb. However, there is still lack of a large, multi-center study, and further related studies are needed.

Objective To study the correlation between 2007 modified TOAST classification and OCSP classification.Methods Totally 177 patients were classified based on the 2007 modified TOAST and OCSP criteria.Analyze whether there was any correlation between the two typing.Results TACI and LACI had significant deviation on distribution of modified TOAST subtype(P

Vertebral artery hypoplasia is a congenital vessel variation. Its incidence is from 1. 9 to 26. 5% . In recent years, studies have shown that vertebral artery hypoplasia may be a potential risk factor for posterior circulation infarction, especialy when it coexists with other cerebrovascular risk factors. Vertebral artery hypoplasia may also cause regional hypoperfusion and complex neurovascular regulation, and it also has a certaln link with migralne.