OBJECTIVE:To study the effects of combined use of cefoperazone/sulbactam(CFS),meropenem(MRP)with le-vofloxacin (LVX) on mutant prevention concentration for Acinetobacter baumannii so as to provide a experimental foundation for preventing bacterial drug resistance. METHODS:In the test,there were groups of single use of CFS,MRP and LVX,and groups of combined use of CFS+LVX and MRP+LVX. Double dilution agar method was used to respectively detect minimal inhibitory con-centration (MIC) for standard Acinetobacter baumannii strains ATCC 19606 and 36 clinically isolated strains in all groups,and then the index of fraction inhibitory concentration(FIC)was calculated. Agar dilution method on plates was employed to detect mu-tant prevention concentration (MPC) for Acinetobacter baumannii in all groups,and then corresponding selection index (SI) was calculated. RESULTS:After combined use of CFS or MRP with LVX,synergistic effect accounted for 55%(20/36)and 50%(18/36). For standard strain ATCC 19606,after combined use of CFS+LVX and MRP+LVX,MPC reduced from 32.0 and 4.0 mg/L to 1.8 and 0.8 mg/L;For 36 clinically isolated strains,after combined use of CFS+LVX and MRP+LVX,MPC reduced from 8.0-32.0 and 1.0-2.0 mg/L to 0.25-1.0 and 0.25-0.5 mg/L. SI were all obviously reduced after combination. CONCLUSIONS:The combina-tion of CFS or MRP with LVX can reduce MPC for Acinetobacter baumannii more significantly than the single use,and narrow mu-tant selection window.

Objective To evaluate the effects of different loading occasions of orthodontic force on the stability of miniscrew as an anchorage.Methods The titanium miniscrews were respectively implanted into canine and posterior region of both upper and lower jaws of 3 crossbred dogs.The implants were immediately loaded with 200 g orthodontic force or loaded after 2 weeks of implantation.The dogs were sacrificed after 8 weeks.The samples including the microscrew implant and its around bone tissue were extracted,fixed and X-ray photographed.Then the specimens were decalcified,embedded,sectioned and stained with HE and GOMORI.The sections were examined under light microscope.Results The stability of miniscrew in posterior region of jaws was higher than that in canine region in X-ray photograph.There was more bone trabecular formation between miniscrew and jaw bone in non-immediately loaded group than those in immediately loaded group with HE and GOMORI.Conclusion The non-immediately loaded implant as an anchorage can afford more stability than the immediately loaded implant.

Objective To investigate the accuracy of predicting middle cerebral artery infaction with contin -ue electroencephalograph .Methods 40 cases with middle cerebral artery infaction were divided into malignant groups(14) and binigan groups(26).They were all with continued beside electroencephalograph within 24 hours after admission.Results Abnormal CEEG rate in malignant groups [85.71%(12/14)]was significantly higher than that in binigan groups[65.38%(17/26)](χ2 =10.405,P=0.001).In malignant groups,severe abnormal CEEG was seen in 4 cases developed coma at the second day of admission ,moderate abnormal CEEG was found in 6 cases,slight abnormal CEEG was detected in 2 cases,normal CEEG was detected in 2 cases.Conclusion Early CEEG has a cer-tain value for predicting middle cerebral artery infaction .

Objective To investigate the protective effect of Ambroxol against experimental lung ischemia reperfusion (I/R) injury in a situ hilar clamp model.Method Left lung of rat was rendered and ischemic for 90 minutes,and reperfused for up to 2 hours,as the model.Twenty-four SD rats were randomly divided into 3 groups with 8 rats each group:control group,I/R group,I/R and Ambroxol treatment group (AMB group).Rats of AMB group received Ambroxol (25 mg/kg) Intraabdominally 30 minutes before ischemia and intravenously 5 minutes before reperfusion.After 2 hours of reperfusion,blood-gas analysis,the serum level of IL-1?,IL-8 and TNF-?from carotid artery were delected.The wet/dry ratio of lung,the activity of erythrocuprein (SOD),the content of malonaldehyde (MDA) and the activity of myeloperoxidase (MPO) were determined and pathematology changes were observed in the left lung tissue.Differences within the groups were analysed using two-sample t-test. Results After 2 hours of repeffusion,there were no significant changes of artery partial pressure of oxygen (PO_2) and partial pressure of carbon dioxide (PCO_2) among three groups.The wet/dry ratio of lung,the activity of MPO (U/g) and the content of MDA (nmol/mgprot) of I/R group were (5.3?0.5),(1.30?0.26) and (0.66?0.16),significantly higher than those of the control group (P

Objective To investigate the feasibility and safety of percutaneous interstitial implantation of ~(125)I seeds into the pancreas of pig under CT-guidance. Methods Twelve healthy pigs were equally divided into 6 groups.~(125)I seed implantation into the pancreatic tail under CT-guidance was performed in pigs of study groups (group A-E), while ghost seeds that contained no radioactive materials were used in the control group (group F). Imaging examination and laboratory tests, including serum amylase, hepatic and renal functions, were conducted before and 1, 7, 15, 21, 30, 60 days after the procedure. Every two pigs (group A-E) were sacrificed each time at 15, 30, 45, 60, and 75 days after treatment, and specimens of pancreas, duodenum, liver, kidney, etc. were collected and sent for pathologic examination. Results The ~(125)I seeds were successfully implanted in all pigs. During the follow-up period, no severe complications occurred. Imaging and pathologic studies demonstrated that in study groups necrosis of pancreatic tissue appeared around the implanted ~(125)I seeds in 15 days, the necrosis area increased significantly in 45 and 60 days, and in 75 days the necrosis size remained quite the same as seen in 60 days. No necrosis was found in the control group (group F) 60 days after treatment. No serious complications, such as effusions, hemorrhage or necrosis of the adjacent duodenum, stomach, liver or kidney, occurred 75 days after the treatment. Conclusion Percutaneous interstitial implantation of ~(125)I seeds into the pig's pancreas under CT-guidance is safe and feasible.

Objective To compare the therapeutic effects of CT-guided ~(125)I seed implantation with simple Gemcitabine chemotherapy for the treatment of unresectable pancreatic carcinoma. Methods Forty-six untreated patients with unresectable advanced pancreatic carcinoma were randomly divided into two groups: group A (n = 22), treated with ~(125)I seed implantation and group B (n = 24), treated with intravenous chemotherapy using Gemcitabine only. The clinical benefit response (CBR), objective tumor response (OTR), safety and the improvement of living quality were evaluated and analyzed. Results Three months after the treatment, the OTR rate of group A and group B was 45.5% and 8.33% respectively (P < 0.05). The CBR rate of group A and group B was 47.1% and 25% respectively (P < 0.05). No significant difference in PFS between group A and group B (P > 0.05). And also, the incidence of hematological toxicity and complication between two groups were of no significant difference. Conclusion For the treatment of advanced unresectable pancreatic carcinoma, both simple Gemcitabine chemotherapy and ~(125)I seed implantation are able to obtain a moderate objective response, although ~(125)I seed implantation seems to be more effective than Gemcitabine in improving the living quality and survival rate.

the incidence of the complication.

OBJECTIVETo examine the protective effect of Ginkgo biloba leaf extract (GbE) on learning and memory deficit induced by aluminum chloride (AlCl(3)), and explore its mechanisms.

METHODSThe rat models with learning and memory deficit were induced by administering via gastrogavage and drinking of AlCl(3) solution. And the model rats were treated with GbE at the dose of 50, 100, 200 mg/kg every day for 2 months accompanied with drinking of AlCl(3) solution, respectively. Their abilities of spatial learning and memory were tested by Morris water maze, and the acetylcholinesterase (AChE) activity in serum was assayed with chemical method, the AChE expression in hippocampus was observed by immunohistochemistry assay, and then quantitative analysis was done by BI 2000 image analysis system.

RESULTSLearning and memory deficit of rats could be induced by AlCl(3) solution (P < 0.01), and AChE expressions in rats hippocampus were increased (P < 0.01); GbE ameliorated learning and memory deficit and reduced AChE expression in rats hippocampus in a dose-dependent manner, while GbE significantly increased serum AChE activity at the dose of 200 mg/kg each day (P < 0.05).

CONCLUSIONGbE can ameliorate learning and memory deficit induced by AlCl(3), which may be due to its inhibition of the AChE expression in hippocampus.

Acetylcholinesterase ; metabolism ; Aluminum Compounds ; toxicity ; Animals ; Chlorides ; toxicity ; Dose-Response Relationship, Drug ; Ginkgo biloba ; Hippocampus ; enzymology ; Immunohistochemistry ; Male ; Maze Learning ; drug effects ; Memory Disorders ; chemically induced ; prevention & control ; Neuroprotective Agents ; therapeutic use ; Phytotherapy ; Plant Extracts ; therapeutic use ; Plant Leaves ; Plant Structures ; Rats ; Rats, Wistar ; Reaction Time

Objective To observe the migration ability of different quantity of BMSCs labled with Resovist after transplanted in rat models with Parkinson disease (PD) with 1.5T MR scanner and micro-47 coil, in order to determine the optimal transplanted dosage of BMSCs and observation time in vivo. Methods Forty PD rats were randomly assigned to 5 groups (each n=8) including 1×10~5 BMSCs group, 1.5×10~5 BMSCs group, 2×10~5 BMSCs group, 2.5×10~5 BMSCs group and control group. FFE-T2WI were obtained immediately and 1 week, 4 weeks, 8 weeks after transplantation to measure and compare the volume of hypointense areas of different groups in different time with 1.5T and 47 mm inner diameter micro-coil. At the meantime, rotational behavior was assessed in each group. After MR scanning, the rats were executed and prepared for immunohistochemistry staining at 12 weeks after transplantation. Results Only the extent of the dark region became wider 4 weeks after transplantation in 2×10~5 BMSCs group (P=0.005). The therapeutic efficacy in 2×10~5 BMSCs group was the best confirmed by behaviour studies (P=0.02). Conclusion For the treatment of PD and evaluation of the migratory ability of BMSCs, the optimal transplanted dosage of BMSCs is 2×10~5, while the best observation time is 4 weeks after transplantation.

Natural products are important sources of drug discovery. However, the traditional methods of extraction and isolation, as well as chemical synthesis for obtaining natural products are associated with issues such as operational complexity, high costs, low efficiency, and environmental pollution. Constructing microbial cell factories through synthetic biology methods to produce medicinal natural products has the advantages of high efficiency, low cost, and environmental protection. Nevertheless, the scope and yield improvement of the products are limited by the limitations of enzymes in microbial cell factories. Protein engineering is considered one of the most effective approaches to overcome these limitations. This article introduces commonly used methods of protein engineering technology and summarizes its specific applications in improving enzyme performance, modifying the enzymatic environment, and promoting the development of synthetic biology tools in the field of pharmaceutical natural product synthesis. Furthermore, it analyzes the current bottlenecks and challenges in protein engineering and looks forward to its future application prospects, offering insights for the development and practical use of protein engineering technology.