1.A finite element analysis of six-segment classification of femur intertrochanteric fracture
Zhenyuan CHEN ; Kainan LI ; Zhixi ZHANG
Chinese Journal of Orthopaedic Trauma 2015;17(5):433-437
Objective To explore the mechanism of six-segment classification of femur intertrochanteric fracture in a three-dimensional finite element model of upper thigh-bone and its clinical relevance.Methods The left upper thigh-bone of a normal male volunteer of 60 years old was scanned using 64-slice CT.After the images were stored in the format of JPG,they were input into photoshop 7.0 for three-dimensional creation.The three-dimensional images were used to make a three-dimensional finite element model of upper thigh-bone using software Super 93.The model consisted of 764 nodes and 531 units (including 306 compact bone units and 225 cancellous bone units).In this model,the stress distribution at the trochanter during human tumbling was analyzed by imitating adduction,abduction,adduction-intemal rotation and abduction-external rotation of the hip,as well as intense muscular contraction of gluteus medius,piriformis and iliopsoas during adduction-internal rotation of the hip.Results Analysis of stress nephogram showed that the stress was distributed mainly at the exterior cortical bone and spread to the inter-trochanteric part in simple hip adduction (two-part fracture) and distributed mainly at the interior cortical bone and spread to the inter-trochanteric part in simple hip abduction (two-part fracture).In adduction-internal rotation or abduction-external rotation of the hip,the stress was focused on the anterior and posterior walls of the greater trochanter and trochanteric part and spread to the exterior and interior cortical bone and the inter-trochanteric part (three-or four-part fracture).During intense muscular contraction of gluteus medius,piriformis and iliopsoas during adduction-internal rotation of the hip,the stress was focused on the anterior and posterior walls of the greater trochanter,lesser trochanter and trochanteric part and spread to the exterior and interior cortical bone and the inter-trochanteric part (five-or six-part fracture).Conclusions The six-segment classification of femur intertrochanteric fracture explains complex stress distributions after human falling.When combined with three-dimensional CT reconstruction,it is more intuitive than other classifications so that it can provide more definite surgical advice for different types of fracture.
2.Enhancing accumulation of indole alkaloids in Catharanthus roseus leaves
Xiusheng ZHANG ; Rongtao ZHANG ; Lili NIE ; Yuhai GUO ; Zhixi ZHAI
Chinese Traditional and Herbal Drugs 1994;0(02):-
Objective To study the effect of three kinds of reagent: ethrel, Aspirin, tryptophan on the accumulation of medicinal component in Catharanthus roseus leaves. Methods To treat these potplants of C. roseus in green house with the three reagents in different concentrations, respectively. Then, two days later, the contents of catharanthine and vinblastine in leaves were determined by RP-HPLC. Results The three reagents can obviously improve the accumulation of indole alkaloids, including catharanthine and vinblastine in C. roseus leaves. Their optimum treatment concentration was finally comfirmed. Conclusion These three kinds of reagent apparently promote the accumulation of total indole alkoloids in the leaves of C. roseus.
3.Relationship Between Melatonin Hypo-secretion and Kidney-yin Deficiency Syndrome During Prepubescence
Jian WANG ; Qun CHEN ; Wei ZHANG ; Zhixi CHEN
Journal of Guangzhou University of Traditional Chinese Medicine 2004;0(05):-
[Objective] To explore the relationship between neuroendocrine changes caused by melatonin (MT) hypo-secretion and kidney-in deficiency syvndrome during prepubescence. [Methods] Thirty SD rats after ablactation were randomly divided into normalgroup (group. A), model group (group B) and herbal medicine group (group C, treated with kidney-yin-nourishing ande(?)ficiency-fire-clearing herbs). Rats in groups B and C were exposed to light continuously for 30 days and simultaneously groupC was given kidney-yin-nourishing and deficiency-fire-clearing herbal medicine (13.3 g?kg-1?d-1, qd) for 30 days . After treatment, blood samples were collected at 0:00-2:00 o'clock to observe the changes of blood MT, testosterone (T), epinephrine (E) and norepinephrine (NE) levels. [Results] Body weight and blood MT level decreased, and T, NE and E levels increased in group A (P
4.Study on viability of Cistanche deserticola seeds
Qingliang CHEN ; Xiusheng ZHANG ; Yuhai GUO ; Zhixi ZHAI ; Chongjun YANG ; Hualei WANG
Chinese Traditional and Herbal Drugs 1994;0(09):-
Objective To improve the 2,3,5-triphenyl tetrazolium chloride (TTC) solution method for measuring the viability of Cistanche deserticola seeds and investigate the change in viability during storage at 5 ℃. Methods The effect of the testa,TTC concentration,sodium hypochlorite concentration (NaClO),and staining time were studied,and seed viability during storage at 5 ℃ was measured with the improved method. Results Seeds were kept for 48 h in 0.5% TTC solution at 40 ℃,and then for 2 h in 0.2% NaClO solution;Seed viability was measured under a stereomicroscope. Storing seeds of C. deserticola for 1 to 2 years at 5 ℃ had no significant effects on their viability. However,the percentage of seeds with high viability was increased with the extension of the storage time at 5 ℃. Conclusion A convenient and rapid method for measuring the viability of C. deserticola seeds is developed. Storing C. deserticola seeds at 5 ℃ could improve their viability
5.EST-based Analysis of Gene Expression in the Porcine Brain
Zhang BING ; Jin WU ; Zeng YANWU ; Su ZHIXI ; Hu SONGNIAN ; Yu JUN
Genomics, Proteomics & Bioinformatics 2004;2(4):237-244
Since pig is an important livestock species worldwide, its gene expression has been investigated intensively, but rarely in brain. In order to study gene expression profiles in the pig central nervous system, we sequenced and analyzed 43,122 highquality 5′ end expressed sequence tags (ESTs) from porcine cerebellum, cortex cerebrum, and brain stem cDNA libraries, involving several different prenatal and postnatal developmental stages. The initial ESTs were assembled into 16,101 clusters and compared to protein and nucleic acid databases in GenBank. Of these sequences, 30.6% clusters matched protein databases and represented function known sequences; 75.1% had significant hits to nucleic acid databases and partial represented known function; 73.3% matched known porcine ESTs; and 21.5% had no matches to any known sequences in GenBank. We used the categories defined by the Gene Ontology to survey gene expression in the porcine brain.
6.The effects of gait training with a gait orthosis on the neurogenic bladder after spinal cord injury
Dan TANG ; Guoxian PEI ; Xinghua YANG ; Siwen LIU ; Hao LIU ; Zhixi SHI ; Xiaoqian DENG ; Jun WANG ; Zhijie ZHANG ; Kuicheng LI
Chinese Journal of Physical Medicine and Rehabilitation 2010;32(8):606-608
Objective To explore the effects of gait training with an alternative gait orthosis (AGO) on the neurogenic bladders of patients with spinal cord injury (SCI). Method Twelve patients with complete SCI at the thoracic and lumbar level were trained for 8 weeks on motor and bladder function. After that, specific gait training with an AGO was given for another 8 weeks. American Spinal Injury Association ( ASIA ) sensation and motor function assessments were done before and after the gait training with the AGO, and bladder capacity, residual urine and urine flow rates were also assessed. Results Compared with pre-treatment there was no significant difference in average ASIA senzsation and motor scores after training, but the maximum rate of urine flow, average urine volume and single urination had significantly increased and residual urine volume had significantly decreased. Conclusions Therapeutic gait training with an AGO can improve bladder function after SCI.
7.Optimization of bacterial cellulose fermentation medium and observation of bacterial cellulose ultra-micro-structure.
Ruiqin WU ; Shuangkui DU ; Zhixi LI ; Xiaohui XING ; Dongyan SHAO ; Yanli FAN ; Bo LI ; Xueliang ZHANG ; Lijun BU
Chinese Journal of Biotechnology 2008;24(6):1068-1074
In order to improve the yield of bacterial cellulose (BC), the fermentation medium of BC-producing strain J2 (Gluconobacter) was optimized, and BC ultra-micro-structure was observed. Initially, Plackett-Burman design was employed to evaluate eight variables which were relevant to BC production. Three statistically significant parameters including yeast extract, ZnSO4, ethanol were selected and other 5 variables were not significant (P > 0.05). The optimized levels of three variables were defined by Box-Behnken design and response surface methodology (RSM). BC ultra-micro-structure was observed by scanning electron microscope (SEM) with cotton cellulose as comparison. The results indicated that the BC yield under the optimum fermentation medium was 11.52 g/100 mL, which was as 1.35 times as that under the original fermentation medium. The SEM photos manifested that bacterial cellulose ribbon, with a diameter less than 0.1 microm, was less than cotton cellulose ribbon. The bacteria inside the cellulose net were eliminated after the NaOH treatment.
Cell Culture Techniques
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Cellulose
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biosynthesis
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ultrastructure
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Culture Media
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chemistry
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Fermentation
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Gluconobacter
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cytology
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metabolism
8.Recent advances in research on chelators as metallo-β-lactamase inhibitors
Zhixi ZHU ; Jielin ZHANG ; Yijun CHEN
Journal of China Pharmaceutical University 2022;53(4):410-422
The major reason for the resistance of Gram-negative bacteria to β-lactam antibiotics is the expression of β-lactamases.Metallo-β-lactamases (MBL) hydrolyze almost all types of β-lactam antibiotics including carbapenems, posing a challenge to global public health. Developing MBL inhibitors is an important method to treat the infections caused by resistant bacteria. As an important type of MBL inhibitors, chelating agents can inhibit MBL by chelating, stripping, and binding Zn2+ in the active center of MBL.This review summarizes recent publications on chelators as MBL inhibitors, discussing their chemical structures, inhibitory potency, synergistic effects with antibiotics, selectivity and mechanism of action, including EDTA and related compounds, aspergillomarasmine A (AMA) and its derivatives, NOTA and related compounds, pyridine carboxylic acid and pyridine methylamine compounds, aiming to provide reference for future development of potent, selective and safe clinical MBL inhibitors.
9.Comparison of different regimens in isoprenaline-induced chronic heart failure models
Yuquan TAN ; Junyu ZHANG ; Meng YANG ; Fei WANG ; Senjie ZHONG ; Lin LI ; Zhixi HU
Acta Laboratorium Animalis Scientia Sinica 2024;32(2):161-167
Objective To compare animal models of chronic heart failure(CHF)prepared by three different protocols,to establish a stable,reliable,and reproducible mouse model of CHF.Methods Twenty-five male C57BL/6J mice were divided randomly into four groups:a blank group,model A group(MA group),model B group(MB group),and model C group(MC group).The model groups adopted different preparation protocols for continuous injection of isoprenaline.The MA group and MB group were dose-decreasing models:MA group:subcutaneous injection of 10 mg/kg on day 1,5 mg/kg on day 2,2.5 mg/(kg·d)on days 3~30,total 30 days;and MB group:subcutaneous injection of 20 mg/kg on day 1,10 mg/kg on day 2,5 mg/(kg·d)on days 3~14,total 14 days.The MC group used a constant dose of intraperitoneal injection of 7.5 mg/(kg·d)for 28 days.The day after the final injection,the survival and model-formation rates for each group of mice were calculated.Cardiac function was measured by cardiac ultrasound and serum levels of N-terminal pro B-type natriuretic peptide,interleukin-6,and tumor necrosis factor-α were measured.Results CHF was successfully induced in all the model groups after all injections at the end of the fourth week.However,comprehensive test result showed that the MC model was the most stable.Conclusions An isoprenaline-induced mouse model of CHF using constant intraperitoneal injection of 7.5 mg/(kg·d)for 28 days may be the most suitable model for subsequent research on traditional Chinese medicine.
10.Development of a nomogram prediction model based on 3D quantitative parameters for mediastinal lymph node metastases in clinical stage ⅠA lung adenocarcinoma
Zhixi LI ; Yongjun PAN ; Zhikang YE ; Yingjun ZHOU ; Guoneng CHEN ; Zhichao ZUO ; Wei ZHANG
Journal of Practical Radiology 2023;39(12):1936-1940
Objective To develop a nomogram based on pulmonary nodules preoperative CT signs and 3D quantitative parameters for predicting mediastinal lymph node metastases in patients with clinical stage ⅠA lung adenocarcinoma.Methods The imaging data of 164 patients who underwent preoperative CT scan and systematic lymph node dissection were analyzed retrospectively.Commercially available AI software was used to extract 3D quantitative parameters of pulmonary nodules automatically,and CT signs of pulmonary nodules were analyzed.Logistic regression was used to explore the role of these parameters in predicting pathological nodal involvement.A nomogram prediction model was established,then discrimination and calibration of the model were evaluated.Results Among 164 enrolled patients,19(11.6%)were tested positive for mediastinal lymph node metastases at pathology review.The nomogram incorporated spiculation,lobulation,the largest cross-sectional area,and carcinoembryonic antigen(CEA).The model showed great discrimination and calibration,with a C-index of 0.942[95%confidence interval(CI)0.923-0.961].The predicted value of the model fitted well with the actual observed value on the calibration curve.Conclusion The nomogram prediction model based on preoperative CT signs,3D quantitative parameters,and CEA can estimate the probability of mediastinal lymph node metastases in clinical stage ⅠA lung adenocarcinoma.This model may help with clinical decision-making and individualized evaluation.