BACKGROUND: Carboxymethyl chitosan is a water-soluble derivate modified from chitosan, with various biological activities. It is a good ligand of metal ion and can integrate Ca~(2+) to prepare a novel biological material. OBJECTIVE: To explore a method for preparing carboxymethyl chitosan calcium (CCC) and analyze its properties and structure. METHODS: CCC was produced by carboxymethyl ohitosan reacting with solution of calcium chloride. The solubility, carboxymethylation degree, rotational viscosity, and calcium content of CCC were determined, and infrared and ultraviolet spectral analyses were performed.RESULTS AND CONCLUSION: The calcium content of CCC was approximately 15%. Compared with carboxymethyl chitosan, infrared spectrum and ultraviolet spectrum of CCC were changed. The prepared CCC is a new calcium compound through property and structural analysis.

Objective To observe the effect of carboxymethyl chitosan calcium(CCC) on the concentration of lead,calcium,and liver antioxidative capacity in lead poisoned mice.Methods mice were randomly divided into 6 groups.Three test groups were treated with CCC at three doses.The lead poisoned mice model was established by giving water containing lead acetate,and then CCC was administered to mice once a day.After 30 days,the mice were killed and the content of lead in blood,liver,brain and femur were determined by atomic absorption spectrophotometer,and antioxidative capacity in liver was measured using assay kit.Results CCC could reduce the contents of lead in blood,brain,liver and femur significantly,decrease the level of maleicdialdehyde(MDA),increase activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and total antioxidative capacity(T-AOC) in liver markedly. Conclusion CCC can promote the excretion of lead,increase the content of calcium in femur and antioxidative capacity in lead poisened mice.

Essential tremor (ET) is a common dyskinesia disease characterized by tremor. ET is clinically heterogeneous. In addition to the motor symptoms with tremor as the main manifestation, it also includes non-motor symptoms such as neuropsychiatric symptoms (anxiety, depression), personality changes, sleep disorders, etc. Among them, anxiety and depression are the most common, and gradually worsen as the disease progresses, causing adverse effects on the quality of life of patients. Therefore, the early clinical full text of looking for ET psychiatric symptoms seems to have no content of the evaluation scale and is irrelevant. It is suggested that removing biomarkers plays an important role in the diagnosis and treatment of ET patients. Genome-Wide Association Studies (GWAS) describes the SLC1A2 gene associated with ET, and the EAAT2 or GLT1 encoded by this gene is associated with the anxiety and depression phenotypes of ET patients in non-motor symptoms. Up to now, the pathogenesis of ET patients is not clear, but many reports confirm that genetic factors play an important role in the pathogenesis of ET. Among them, SLC1A2 is expected to become a biomarker of the neuropsychiatric phenotype of the disease, providing a basis for clinical workers to take corresponding intervention measures in time. This article reviews SLC1A2 gene and essential tremor.

Parkinson′s disease (PD) is the second most common neurodegenerative disease in middle-aged and elderly people. In addition to motor symptoms, PD also has many non motor symptoms, such as dysosmia, constipation, cognitive impairment, etc. Among them, dysosmia is a common non motor symptom of early Parkinson′s disease. Research has confirmed that olfactory dysfunction (OD) can appear before the typical clinical symptoms of PD, which is of great significance to the diagnosis and treatment of diseases. However, at present, the pathogenesis of OD is still unclear, and the inspection methods have not been unified, and there is no complete cure. This article reviews the latest research progress of dysosmia in Parkinson′s disease.

Objective To observe the influence of different energy windows of the medium-energy general-purpose(MEGP)collimator on image quality,so as to optimize the energy window of yttrium-90(90Y)bremsstrahlung SPECT imaging.Methods 90Y bremsstrahlung spectrum was acquired,and the sensitivity,percentage of the source counts in useful field of view(S/FOV%)and signal-to-background ratio(S/B)of 90Y bremsstrahlung SPECT imaging at MEGP under different energy windows were compared.Results The energy spectrum of 90Y bremsstrahlung was a continuous curve,with the peak of 76.2 keV with MEGP collimator.The images obtained with MEGP collimator were clear,and no significant differences of S/FOV%nor S/B was found between 10%and 20%window width groups(both P＞0.05),but the sensitivities of the latter was higher than the former(P＜0.05).The sensitivity of 70-90 keV images was relatively high,while the S/FOV%and S/B had decreased.The S/FOV%and S/B of images ranging from 40-60 keV were high,but the sensitivity was low.Images acquired with 100 keV±20%showed fairly high sensitivity,S/FOV%and S/B,which was 69.73%,0.62 and 1.64,respectively.Conclusion When performing 90Y bremsstrahlung SPECT with MEGP collimator,the image quality at 20%window width was better than at 10%window width,and 100 keV±20%showed fairly high sensitivity and not significantly decreased S/FOV%and S/B.