4. Application of microwave mutagenesis in microorganism breeding for medicinal source strain improvement
Journal of International Pharmaceutical Research 2010;37(6):426-434
Microwave mutagenesis has become a new physical mutation technique by non-ionizing electromagnetic radiation, which has been used in the breeding of crops, plants and microorganisms, and has revealed bright future development in its application in the microorganism breeding for medicinal source strain improvement for providing high productivity or diverse bioactive mutants. This article reviews bioeffects of microwave, possible mechanisms of microwave mutagenesis, methods of microwave mutation technique together with main factors probably affecting microwave mutagenesis, and research advances in the application of microwave mutagenesis in microorganism breeding for medicinal source strain improvement. Meanwhile, the present research status, advantage and disadvantage, and prospect of this technique are also discussed focusing on its application in the microorganism breeding for medicinal source strain improvement.
5. Alteration of secondary metabolism of inactive actinomycete strain by magnetic nanoparticle-aided microwave mutagenesis
Journal of International Pharmaceutical Research 2010;37(6):456-460
Objective: To investigate a new method for altering the secondary metabolism of inactive actinomycete strain by magnetic nanoparticle-aided microwave mutagenesis to obtain antitumor mutants. Methods: HLF-43, a marine-derived actinomycete strain without antitumor activity with the inhibition rate of 3.9% at the 1000 μg/ml sample concentration on K562 cells, was used as the initial strain in the present study. The spore suspension of HLF-43 was exposed to the microwave radiation (the frequency 2450 MHz, the power 464 W)under the presence of Fe3O4 magnetic nanoparticles, then spread on neomycin-containing plates and the neomycin-resistant (neo) mutants were selected during incubation at 28°C for 4-14 days. The initial strain HLF-43 and its neo mutants were fermented to obtain fermentation samples and the antitumor neo mutants were obtained by the test of antitumor activity for these samples at 100 μg/ml. The antitumor activity was assayed by the MTT method using K562 cells. Results: A new method has been created for altering the secondary metabolism of actinomycete strain by magnetic nanoparticle-aided microwave mutagenesis. By the method coupled with the neo mutant selection, a total of 80 neo mutants were obtained from the inactive-initial strain HLF-43 and 28 of them were antitumor mutants with the inhibition rates over 20% at the 100 μg/ml sample concentration on the K562 cells. The antitumor mutants could be obtained at quite high frequency of 35% (28/80). Conclusion: Compared with the microwave mutagenesis without the aid of Fe3O4 magnetic nanoparticles, the Fe3O4 magnetic nanoparticle-aided microwave mutagenesis is more favorable to obtain the neo mutants resistant to higher concentration of neomycin and to obtain the antitumor neo mutants at higher frequency.
6.Progresses on Biosynthesis of Long Chain Polyunsaturated Fatty Acids in Plant
China Biotechnology 2006;0(12):-
There is immense interest in the long-chain polyunsaturated fatty acids(LC-PUFAs) on account of their health-beneficial properties.There has been considerable interest in the production of LC-PUFAs in transgenic plants to provide a cheap,sustainable and clean source of these fatty acids.Several main LC-PUFAs,their roles and metabolic pathway in plant are introducedbriefly,progresses on biosynthesis of LC-PUFAs in transgenic plant are reviewed,and strategies for improving the yields of LC-PUFAs in plant are also discussed.
7.Advances in Application Studies of FAD2 on Biosynthesis of Industrial Fatty Acids
China Biotechnology 2006;0(05):-
Many unusual fatty acids present in the seed oils of non-food plants are modified at the ?12 position either by the addition of epoxy or hydroxy groups or by the formation of triple (acetylenic) bonds or conjugated double bonds. The introduction of these functionalities into C18 fatty acids is catalyzed by a family of divergent forms of the fatty-acid ?12-desaturase (FAD2) enzyme. Genes encoding these enzymes have now been cloned from a variety of organisms and expressed in transgenic oilseeds. However,the accumulation of the intended fatty acids in transgenic plants has been relatively disappointing,and the mechanisms of these unusual fatty acids biosynthesis and transferring from phosphatidylcholine into storage triacylglycerols still need to be elucidated.
8.The Acting Mechanisms of Statins and Their Application in the Prevention and Treatment of Stroke
Ding-Ming SUN ; Zhi-Jun ZHANG ;
International Journal of Cerebrovascular Diseases 2006;0(10):-
Stroke is one of the most important causes of disability throughout the world.Epide- miological and clinical studies have demonstrated that statins significantly decrease the incidence of ischemic stroke.In addition to lipid-lowering effect,statins may also have a number of other acting mechanisms that are not dependent on reducing cholesterol levels.Moreover,statins inhibit cerebral vasospasm caused by subarachnoid hemorrhage.For most of the individuals,the safety and tolerability of statins are well.
9.Application of two-dimensional speckle tracking on long-term prognosis of patients with acute infarcted myocardial
Jun WANG ; Jun ZHANG ; Zhi GUO ; Haoran DI
Clinical Medicine of China 2014;30(12):1281-1284
Objective To assess the effect of two-dimensional speckle tracking imaging (STI) on prognosis of patients with acute infarcted myocardial(AMI).Methods Eighty patients with AMI and 30 healthy subjects were selected as our subjects.Among the AMI patients,there was 30 cases were emergency percutaneous coronary intervention (PCI),25 cases were selective PCI group and 25 cases with conservative.All were performed a 4-6 months following up after discharge from hospital.Left ventricular ejection fraction(LVEF) was measured by Simpson's.Rotation were measured in the left ventricular basal and apical short-axis views using STI.LV Peak twist (Ptw),apical Peak rotation (PAR),the basal Peak rotation (PBR),twist at aortic valve closure(AVC tw),twist at mitral valve opening(MVO tw),untwisting rate (Untw R),and half time of untwisting (HTU) were calculated.And the correlation between Ptw and LVEF was analyzed.Results Compared with the control group,the value of Ptw,PAR,AVC tw and MVO tw were significantly decreased in myocardial infarction group(F =22.481,12.899,18.923 ;P < 0.05).Ptw,PAR in emergency PCI group at following up periods were (18.61 ± 8.08) ° and (12.16 ± 6.98) °,higher than that in hospital periods ((13.76 ± 6.31) °,(7.03 ±5.76)°).Ptw,PAR in selecting PCI group were (19.5 ±7.73)° and (13.4 ±7.02)°,higher than that in hospital periods((15.25 ± 6.83) °,(9.69 ±.6.72) ° ; t =-2.607,-3.104,-2.079,-1.955 ; P < 0.05).Significant correlation was found between Ptw and LVEF (r =0.527,P < 0.05).Conclusion Left ventricular twist can be measured using STI.LV rotation can be the quantitative index to evaluate the systolic function of LV.STI can be the new method to guide clinic diagnosis and therapy.
10.Diagnosis and treatment of tumor-associated gastrocolic fistula: a report of 4 cases
Jun CAI ; Jie YIN ; Zhi ZHENG ; Kangli WANG ; Zhongtao ZHANG
International Journal of Surgery 2014;41(8):540-544,封3
Objective To explore the diagnosis and treatment of tumor associated gastrocolic fistula (GCF).Methods The records of the 4 patients with GCF between August 2008 to February 2014 were retrospectively analyzed.Three female and one male patients,those whose average age were 61 years,have been pathologically diagnosed postoperatively as gastrocolic fistula caused by malignant diseases.The main clinical symptoms were diarrhea (3 cases),fecal vomitus (3 cases),weight loss (4 cases),and abdominal pain (4 cases).Positive diagnostic tests for GCF included gastroscope (3 cases),colonoscope (1 case),barium enema (1 case),upper gastrointestinal contrast (2 cases).Results En-bloc resection of the involved gastrocolic region have been performed for all,2 patients underwent radical gastrectomy and colon resection and 2 patients were taken on palliative procedure.Pathology indicated adenocarcinoma all,Immunohistochemical detection for CK20,CDX-2 were applied for identifying the originations of tumors.Delayed gastric emptying and DIC occurred in one patient who died in 3 months after the operation,anastomotic leakages were found in 2 cases.The survival patients were all discharged and taken capecitabine combined with Oxaliplatin for chemotherapy.Conclusions Endaoscopy and gastrointestinal imaging are main evidences for diagnosis of GCF.En-bloc resection of the involved gastrocolic region were recommended,enterostomy was safer than entero-anastomosis in one stage procedure.The originations of tumors may be identifying according to the pathological characteristic and CDX-2,CK20 staining.Adjuvant chemotherapy should be applied.