Objective To study the genetic toxicity of magnesium sulfate to the root tip cells of Vicia faba. Methods The root tip cells of Vicia faba with 1.5-2 cm root tip were taken as the subjects and were exposed to magnesium sulfate of different concentrations(0.50%-2.00%) for 6 h. In the other test,the cells were treated with 1.5% magnesium sulfate for 2,4,6,8 and 10 hours respectively. The distilled water and potassium dichromate (0.05%) were used as the negative and positive control respectively. The micronucleus and the chromosomal aberration were calculated after 24 hours of culture. Results Compared with the negative control group,0.1%,0.15%,0.175% and 0.2% of magnesium sulfate increased the micronucleus and 0.05%,0.1%,0.15%,0.175%,0.2% of magnesium sulfate increased the chromosomal aberration in Vicia faba root tip cells. Compared with the control group (0 h),both of the micronucleus and the chromosomal aberration of Vicia faba root tip cells increased (P

OBJECTIVE To investigate the distribution and resistance of commonly encountered pathogens,and provide reference of antimicrobial agents.METHODS For the clinical specimens during the last three years,flora identification and bacteriostatic test were operated with Microscan WalkAway-40.RESULTS Gram-negative bacteria were 252,507 and 742 strains,Gram-positive bacteria were 142,166,and 243 strains,fung were 0,26,and 229 strains from 2002 to 2004,respectively,the most commonly encountered Gram-negative bacteria were Escherichia coli,Klebsiella pneumoniae,Pseudomonas aeruginosa,Enterobacter cloacae,and Acinetobacter baumannii;the Gram positive bacteria were Staphylococcus aureus,S.epidermidis,S.haemolyticus,and Enterococcus.CONCLUSIONS It is important for reasonable drug application to know the distribution and resistance of commonly encountered bacteria.

Objective To evaluate the mechanical stability of alternative reconstruction methods after total en bloc spon?dylectomy in the lower lumbar spine. Methods Eight adult fresh cadaveric lumbosacral spines (L1-S1) were adopted. Total en bloc spondylecotmy of the L4 vertebra was performed after intact testing. Four designed reconstruction samples were tested for the range of motion (ROM) of the spine:1) expandable artificial vertebral body and short posterior instrumentation at L3-L5 (SP), 2) ex?pandable artificial vertebral body and short posterior instrumentation with additional anterolateral fixation at L 3-L5 (ASP), 3) ex?pandable artificial vertebral body and multilevel posterior instrumentation at L2-S1 (MP), 4) expandable artificial vertebral body and multilevel posterior instrumentation with additional anterolateral fixation at L2-S1 (AMP). Nondestructive biomechanical test?ing was performed on each construct under loading control. The ROM for each construct was obtained by applying pure moments in flexion, extension, lateral bending, and axial rotation. Results In flexion, extension and lateral bending, the ROM of all the re?constructed constructs significantly decreased compared to the intact. The ROM of specimens with anterolateral fixation was less when compared to the ones without additional fixation. In lateral bending, MP (L:1.87° ± 0.32° , R:1.97° ± 0.33° ), ASP (L:1.89° ± 0.37°, R:2.08°±0.36°) and AMP (L:1.32°±0.29°, R:1.61°±0.33°) provided significantly less ROM than the SP (L:3.14°±0.35°, R:3.44°±0.34°). In axial rotation, the ROM of ASP (L:4.21°±0.58°, R:4.02°±0.59°) and AMP (L:3.56°±0.55°, R:3.52°±0.48°) was significant decreased when compared to the intact state (L: 7.47° ± 1.00° , R:7.57° ± 0.84° ). MP (L:6.33° ± 0.71° , R:5.88° ± 0.62°), ASP and AMP showed significantly less ROM than the short posterior fixation (L:9.28°±1.01°, R:9.48°±0.98°). AMP sig?nificantly decreased the ROM compared to MP. Conclusion After total en bloc spondylectomy of lower lumbar, long segmental fixation provided more stability to the construct than the short one. Compared to posterior fixation, circumferential fixations showed a higher stability. In contrast, multilevel segmental instrumentation with circumferential fixation did not provided more stability than the short constructs.

Based on the approaches of TLC identification, HPLC for assaying managiferin, and of the determination of water, total ash and acid-insoluble ash in 12 samples, collected from southwest of China, the quality standard of Gentiana rhodantha has been established. The results show the reference materia medica and mangiferin can be both well used as reference substances for TLC identification; the mass fractions of mangiferin is 0.7%-4.4% (average 2.8%), water 6.1%-8.6% (average 7.2%), total ash 3.7%-10.8% (average 6.6%) and acid-insoluble ash 0.2%-2.7% (average 1.3%). The recommended standards of quantitative indexes are that the mass fractions of mangiferin is not less than 2.0%, and the water, total ash and acid-insoluble ash are not more than 9.0%, 8.0% and 3.0% respectively.
Chromatography, High Pressure Liquid ; Chromatography, Thin Layer ; Drugs, Chinese Herbal ; analysis ; Gentiana ; chemistry ; Reproducibility of Results

Genome shuffling methods were explored for Bacillus subtilis strain molecular breeding. Recycling protoplast fusion, recycling transformation and recycling universal transduction were used for genome shuffling in B. subtilis. Four strains with different nutrition-deficiency markers were used as initial strains. After five rounds protoplast fusion, transformation or transduction, the descendant with 4 markers had not been detected, and the rate of descendant with 3 markers were 4.53 x 10(-4), 1.64 x 10(-4), 4.47 x 10(-3), respectively. A computer program was made to simulate the recycling fusion process. Based on simulation result and comparing the genome shuffling result of B. subtilis in this experiment and that of Streptomyces coelicolor reported in references, effective genome shuffling needs a high recombination rate of at least between 10(-3) and 10(-2).
Bacillus subtilis ; classification ; genetics ; DNA Shuffling ; Genetic Techniques ; Genome, Bacterial ; genetics ; Protein Engineering ; Transformation, Bacterial

Objective:To construct a three-dimensional imaging model of the pancreatic head based on the embryological fusion plane, and to provide morphological parameters of the pancreatic head for future developments of basic and clinical researches on the pancreas.Methods:Histologic cross-sections of the pancreatic head with its adjacent structures were made from healthy cadavers. Immunohistochemical analysis of pancreatic polypeptide antibody was then performed to verify the existence and location of the embryological fusion plane reported previously. The histologically positioning method of the embryological fusion plane was then applied to the corresponding sections on computed tomography (CT). Based on the results of the above work, volunteers from the Affiliated Changzhou No. 2 People's Hospital of Nanjing Medical University were then used as research objects. A three-dimensional visualization reconstruction software was used to perform CT image-based structures to include the abdominal pancreas, dorsal pancreas head, and embryo fusion surface. Three-dimensional reconstruction of the pancreatic head, and morphological measurements of the relevant structures of the pancreatic head were then made.Results:Immunohistochemical analysis verified the existence and the position of the embryological fusion plane. The histologically positioning method was then successfully applied to the CT sections. The three-dimensional imaging model of the pancreatic head containing the embryological fusion plane, dorsal segment and ventral segment of head were built based on CT images. A total of 35 volunteers were included, including 19 males and 16 females, aged (48.26±8.26) years, and with a BMI of (22.29±1.78) kg/m 2. The morphological results showed that the volume of the pancreatic head, dorsal pancreas and abdominal pancreas were (32.80±8.15) cm 3, (22.21±6.94) cm 3, (10.59±3.87) cm 3, and the area of the embryo fusion surface was (12.46±3.20) cm 2. All volunteers were then grouped according to gender. Statistical analysis showed that there were no significant differences in the total pancreatic head volume, dorsal pancreatic head volume, abdominal pancreatic volume, and embryo fusion area among the groups ( P>0.05). Conclusions:It was feasible and practical to build a three-dimensional imaging model of the pancreatic head based on the embryological fusion plane by using a 3D computer system. This model and its morphological parameters could provide a new tool for research on pancreas.

Objective To investigate the effect of propofol on pyroptosis and A549 cells via the NLRP3/ASC/caspase-1 pathway.Methods Establish a three-dimensional culture model of A549 tumor cells using ultra-low attachment plates,A549 cells were cultured using ultra-low adsorption culture plates to establish a three-dimensional culture model.The CCK-8 method was used to detect the effect of propofol on A549 cell proliferation;the inflammatory factors interleukin(IL)-18,IL-1β,and IL-6 were detected in the A549 lung cancer cell supernatants using enzyme-linked immunosorbent assays;western blotting was used to detect the expression levels of pyrolysis-asso-ciated proteins NLRP3,ASC,caspase-1,GSDMD-N,and IL-1β in A549 lung cancer cells in each group.Results Compared to the blank control group,the survival rate of A549 cells in low,medium,and high concentrations of propofol in each group decreased in turn(P＜0.05);the levels of inflammatory factors IL-18,IL-1β,and IL-6 in the A549 cell supernatant,and scorch related protein NLRP3,ASC,caspase-1,GSDMD-N,and IL-1β increased with the increased propofol concentrations(P＜0.05).Conclusion The three-dimensional culture model of lung cancer A549 cells was successfully established using the ultra-low adsorption culture method.Propofol can promote cell apoptosis and inhibit the pyroptosis of A549 lung cancer cells via activating the NLRP3/ASC/caspase-1 pathway.

Objective:To investigate the efficacy and safety of comprehensive therapy in the treatment of advanced unresectable hepatocellular carcinoma.Methods:Clinical data of 34 patients with primary liver cancer admitted to Peking Union Medical College Hospital from Nov 2018 to Dec 2020 initially evaluated as unresectable were treated firstly by combined therapy and then underwent reevaluation for further management.Results:A total of 34 patients completed the integrative treatment, and no serious adverse events occurred. Among them, 6 patients were evaluated as partial remission, and underwent successful tumor resection, tumors in 7 patients were stable, and 21 patients suffered from disease progression.Conclusion:After comprehensive therapy, unresectable tumors in some patients could reduce and be rendered resection.

Objective:Lung ultrasound (LUS) has been used in the diagnosis of neonatal respiratory distress syndrome(RDS) successfully, but there have been no multicenter prospective studies to verify its reliability or determine how to grade RDS with LUS findings.This study aimed to discuss the necessity and feasibility of using LUS findings to determine RDS grades through a multicenter prospective study.Methods:Every researcher participated in the National Neonatal Lung Ultrasound Training Course and receiving 3-6 months of lung ultrasound system training at the National Neonatal Lung Ultrasound Training Center.Patients between June 2018 and May 2020 who met the RDS ultrasound diagnostic criteria and had full available clinical data were included in this study.The LUS examination was completed immediately after the patients were admitted to the hospital.Some of them also underwent chest X-ray examination.Arterial blood gas analysis was completed immediately before or after the LUS ultrasound examination.RDS grading was performed according to the LUS findings and whether the patient had serious complications.Results:A total of 275 qualifying cases were included in this study, which included 220 premature infants and 55 full-term infants, and the primary RDS occurred in 117 cases (42.5%), and secondary RDS occurred in 158 cases (57.5%). LUS manifestations of RDS patients can be divided into three categories: (1)A ground-glass opacity sign: which could be found among 50 infants when they were admitted to the hospital (that was, at their first LUS examination). Twenty-eight of these infants were considered to have wet lungs and were not sent for special management on admission, but LUS showed typical snowflake-like lung consolidation within 0.5 to 4 hours.Twenty-two of them were given mechanical ventilation with exogenous pulmonary surfactant; Eighteen cases were controlled within 6-12 hours, but the lung lesions became more severe in the other 4 infants (due to severe intrauterine infection). (2)Snowflake-like lung consolidations: the first LUS on admission showed typical snowflake-like lung consolidation involving areas ranging from 1-2 intercostal spaces to 12 lung divisions in 204 cases.Thirty-eight infants among them the lung consolidation only had involvement of 1-2 intercostal spaces at the time of admission; Fifteen of them received invasive respiratory support and recovered within 4-12 hours.Twelve patients received noninvasive respiratory support; Seven of them recovered, while five cases developed severe lung illness.The remaining 11 patients who were not given any form of ventilator support developed severe conditions within 1-4 hours.Thirty of them showed snowflake signs involving 12 lung regions at admission.The remaining 136 patients had lung consolidation degree between the two degree above condition.(3)Snowflake-like sign with complications: Twenty-one patients had severe complications such as pneumothorax, pulmonary hemorrhage or/and persistent pulmonary hypertension of the newborn or large area atelectasis, etc, although snowflake lung consolidation did not involve all lung regions.Conclusion:(1) LUS is reliable and accurate for diagnosing RDS.RDS has the same characteristics on ultrasound for both preterm and full-term infants, both primary and secondary RDS.(2) To facilitate the management of RDS, it is necessary to classify RDS according to the ultrasound findings and the presence of severe complications.(3) Based on the results of this study, it is recommended that RDS can be divided into mild, moderate and severe degrees.The exact standards for grading are as follows: Mild RDS: the early stage of RDS, in which lung consolidation shows as a ground-glass opacity sign on ultrasound; Moderate RDS: lung consolidation shows a snowflake sign on ultrasound, not all of the lung fields are involved; Severe RDS meets one or more of the following criteria: lung consolidation shows as a snowflake sign on ultrasound and all lung regions are involved, or regardless of its degree and extent, lung consolidation has caused serious complications, such as pulmonary hemorrhage, pneumothorax, persistent pulmonary hypertension of the newborn, or/and a large area of pulmonary atelectasis.