牡丹笠圆盾蚧生物学特性的研究     

萧蓉萍  司马朝 《河南农业大学学报》1992,26(1):44-47

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体外盐酸处理与PIN对酯酶A4活性影响的关系   总被引：2，自引：0，他引：2  

徐世清  司马杨虎  郑必平  虞晓华  甲斐英则  徐俊良 《蚕业科学》1999,25(3):149-153

从家蚕Ｃ１０８ 品种产下后２ｄ 的滞育性卵纯化酯酶Ａ４ 及其活性抑制多肽ＰＩＮ，体外调查了盐酸处理与ＰＩＮ 对酯酶Ａ４ 的ＡＴＰａｓｅ 活性影响的关系。结果表明：盐酸处理不仅迅速消除了ＰＩＮ 对酯酶Ａ４ 的ＡＴＰａｓｅ 活性抑制作用；盐酸处理使蚕卵酯酶Ａ４ 的ＡＴＰａｓｅ 活性峰提早出现的时间还反映了蚕卵的滞育发育时间。  相似文献   

盐酸刺激量对家蚕卵酯酶A4活性的影响及其与蚕卵活化的关系   总被引：5，自引：0，他引：5  

徐世清  陈息林  司马杨虎  郑必平  虞晓华  甲斐英则  徐俊良 《蚕业科学》2000,26(1):20-26

将产卵后 2 4～ 96h( 2 5℃ )的蚕卵 ,用相同或最佳盐酸刺激量 (浸酸后点青最快、点青卵率最高 )浸酸处理 ,卵龄越大 ,蚕卵点青越迟。蚕卵的点青时间在一定范围内随盐酸刺激量增大而提前 ,超过这一范围 ,则随刺激量增大而延迟。卵龄增大 ,蚕卵酯酶A4和ATPase特征性活性峰出现时间延迟 ;蚕卵经盐酸处理 ,该时间明显提前。产卵后 96h盐酸处理蚕卵 ,酯酶A4的活性峰出现时间随盐酸刺激量增大而提前。随着浸酸卵龄和盐酸刺激量的改变 ,蚕卵酯酶A4的活性峰出现时间与蚕卵点青时间发生一致的变化。盐酸刺激量能够影响蚕卵的活化 (或滞育发育期 )和发育速度。酯酶A4的ATPase活性变化能够反映盐酸处理蚕卵的滞育程度及所使用的盐酸刺激量  相似文献   

家蚕不受精卵发生的几个生化因素   总被引：2，自引：0，他引：2  

司马杨虎  钟生泉  林健荣 《蚕业科学》2000,26(2):71-74

不同蚕品种的不受精卵率与熟蚕血液蛋白含量呈显著的负相关 ( -0 690 3 )。前蛹期 3 2℃高温处理对家蚕蛹血液蛋白含量和过氧化氢酶活性以及不受精卵的发生均有一定影响 ,表现为随高温时间的延长 ,不受精卵增加 ,蛹血液蛋白含量减少 ,过氧化氢酶活性减弱 ,不受精卵率与蛹血液蛋白含量和过氧化氢酶活性呈较明显的负相关关系  相似文献   

The type III effector PthG of <Emphasis Type="Italic">Pantoea agglomerans</Emphasis> pv. <Emphasis Type="Italic">gypsophilae</Emphasis> modifies host plant responses to auxin,cytokinin and light     

Dan M. Weinthal  Sara Yablonski  Sima Singer  Isaac Barash  Shulamit Manulis-Sasson  Victor Gaba 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(3):289-302

Pantoea agglomerans pvs. gypsophilae and betae are related gall-forming bacteria. While P. agglomerans pv. beta initiates gall formation on both beet and gypsophila, the gypsophila pathovar causes gall formation only on gypsophila. PthG is a type III effector determining host range of these pathogens, initiating the hypersensitivity response in beet, but is a virulence factor in gypsophila. The role of PthG and its mode of action in pathogenicity remain unclear. Transgenic Nicotiana tabacum plants expressing pthG were created. PthG over-expression was often lethal, and surviving pthG-bearing lines showed morphological and developmental abnormalities such as leaf deformation and abnormal vascular branching, dwarf stature, loss of apical dominance, seedling apical meristem loss, rapid germination, reduced fertility, plants which cease growth for several weeks later producing a new lateral shoot, and loss of endophyte resistance (bearing unusual saprophyte populations). Some transformants required light for seed germination and showed rapid seedling greening. In in vitro assays PthG expression modified responses to auxin and cytokinin, inhibiting root and shoot production but not callus formation. In vitro differentiation responses to light were modified by PthG expression. This effector may interfere in the plant auxin signalling pathways resulting in higher observed auxin and ethylene levels, and subsequent blockage of root and shoot development. Apparently PthG tunes the host response to high hormone levels, changing the developmental response. Since shoot and root development are delayed, we hypothesize that callus/gall formation is supported by this activity. However, interference by PthG with hormone and light signalling does not explain all the responses observed in pthG-bearing lines.  相似文献   

The Effect of Human Platelet-Rich Plasma on Adipose-Derived Stem Cell Proliferation and Osteogenic Differentiation     

Sima Tavakolinejad  Mohsen Khosravi  Baratali Mashkani  Alireza Ebrahimzadeh Bideskan  Nasser Sanjar Mossavi  Seyyed Mohammad Reza Parizadeh  Daryoush Hamidi Alamdari 《Iranian Biomedical Journal》2014,18(3):151-157

Background: The cultured mesenchymal stem cells (MSC) have been used in many clinical trials; however, there are still some concerns about the cultural conditions. One concern is related to the use of FBS as a widely used xenogeneic supplement in the culture system. Human platelet-rich plasma (hPRP) is a candidate replacement for FBS. In this study, the effect of hPRP on MSC proliferation and osteogenic differentiation has been evaluated. Methods: Human adipose-derived stem cells (hADSC) were expanded. Cells from the third passage were characterized by flow cytometric analysis and used for in vitro experiments. Resazurin and alizarin red stains were used for cell proliferation and osteogenic differentiation assays, respectively. Results: Treatment with hPRP resulted in a statistically significant increase in cell proliferation compare to the negative control group (P<0.001). Cell proliferation in the 15% hPRP group was also significantly higher than that in the 10% hPRP group (P<0.05). Additionally, it caused less osteogenic differentiation of the hADSC compared to the FBS (P<0.001), but in comparison to negative control, it caused acceptable mineralization (P<0.001). Conclusion: These findings indicate that hPRP not only improves the proliferation but also it can be a suitable substitution in osteogenic differentiation for clinical purposes. However, the clinical application value of hPRP still needs more investigation. Key Words: Platelet-Rich Plasma, Adipose tissue, Stem Cells, Cell differentiation, Cell proliferation  相似文献   

The effect of hypovolemia due to hemorrhage on the minimum alveolar concentration of isoflurane in the dog     

Mattson SF  Kerr CL  Dyson DH  Mirakhur KK 《Veterinary anaesthesia and analgesia》2006,33(5):296-301

OBJECTIVE: To determine the effect of hypovolemia on the minimum alveolar concentration (MAC) of isoflurane in the dog. STUDY DESIGN: Randomized, cross-over trial. ANIMAL POPULATION: Six healthy intact mixed breed female dogs weighing 18.2-29.0 kg. METHODS: Dogs were randomly assigned to determine the MAC of isoflurane in a normovolemic or hypovolemic state with a minimum of 18 days between trials. On both occasions, anesthesia was initially induced and maintained for 40 minutes with isoflurane delivered in oxygen while vascular catheters were placed in the cephalic vein and dorsal metatarsal artery. In dogs assigned to the hypovolemic group, 30 mL kg(-1) of blood was removed at 1 mL kg(-1) minute(-1) from the arterial catheter. All dogs were allowed to recover from anesthesia. Thirty minutes after the discontinuation of isoflurane, anesthesia was re-induced with isoflurane in oxygen delivered by face mask. The tracheas were intubated, and connected to an anesthetic machine with a Bain anesthetic circuit. Mechanical ventilation was instituted at a rate of 10 breaths minute(-1) with the tidal volume set to deliver 10-15 mL kg(-1). Airway gases were monitored continuously and tidal volume was adjusted to maintain an end-tidal carbon dioxide level of 35-40 mmHg (4.67-5.33 kPa). Body temperature was maintained at 37-38 degrees C (98.6-100.4 degrees F). The MAC determination was performed using an electrical stimulus applied to the toe web and MAC was defined as the mean value of end-tidal isoflurane between the concentrations at which a purposeful movement did and did not occur in response to the electrical stimulus. The MAC values were compared between groups using a Student's t-test. RESULTS: The MAC of isoflurane was significantly less in hypovolemic dogs (0.97 +/- 0.03%) compared with normovolemic dogs (1.15 +/- 0.02%) (p < 0.0079). CONCLUSIONS AND CLINICAL RELEVANCE: The MAC of isoflurane is reduced in dogs with hypovolemia resulting from hemorrhage. Veterinarians should be prepared to deliver a lower percentage of isoflurane to maintain anesthesia in hypovolemic dogs during diagnostic and therapeutic procedures.  相似文献   

Genotype-Dependent Differential Responses of Three Forage Species to Calcium Supplement in Saline Conditions     

Nayer Azam Khosh Kholgh Sima  Hossein Askari  Hossein H. Mirzaei  Mohammad Pessarakli 《Journal of plant nutrition》2013,36(4):579-597

Salt toxicity comprises of osmotic and ionic components both of which can severely affect root and shoot growth. In many crop species, supplemental calcium (Ca) reduces the inhibition of growth typical of exposure to salt stress. The objective of this study was to compare whole plant growth and physiological responses to interactive effect of salinity and Ca level on three forage species [African millet (AM), tall wheat grass (TW), and perennial ryegrass (PR)] differing in tolerance to sodium chloride (NaCl) salinity. Plants were grown under glasshouse condition and supplied with nutrient solution containing 0, 100, and 250 mM NaCl supplemented with 0.5, 5, or 10 mM calcium chloride (CaCl₂). Plant growth, ionic concentration, water relations, and solute (proline and glycinebetaine) concentrations of the plants were determined two weeks after the salinity treatments. At 100 mM NaCl, there was a moderate reduction in dry matter (DM) production of all three species. A drastic decrease in DM occurred at 250 mM NaCl. Supplemental Ca reduced the adverse effects of salinity on all three species. The TW showed higher shoot and root growth in 100 and 250 mM NaCl than AM and PR. It also showed the highest DM at 5 and 10 mM Ca supplement. The shoot and root DM of TW increased by about 45 and 15%, respectively compared to the control. Chemical analysis indicated that in TW, Ca restricted both uptake and transport of sodium (Na) from root to shoot. It also increased Ca and potassium (K) concentrations in both organs. The transport of K and Ca from root to shoot of AM and PR were decreased by NaCl, but were restored with increasing Ca in the medium. The opposite occurred for Na. In PR, more K uptake was observed in shoot at 250 mM NaCl with 10 mM Ca supplement. The sap osmotic potential (Ψ_S) was the highest in TW at 10 mM Ca in the presence of 250 mM NaCl. Contribution of various solutes to the difference in Ψ_S among the species from the control and 250 mM salt treatment differed greatly. Supplemental Ca induced decline in the leaf Ψ_S of TW which was predominately due to K, glycinebetaine, Na and proline accumulation. Addition of 10 mM Ca to the growth medium maintained a low Na and a high K level. Accumulation of glycinebetaine and proline in leaf contributed the NaCl tolerance of TW. The presented results suggest that supplement Ca, not only improved ionic relations but also induced plant ability in production of compatible solutes (glycinebetaine and proline) and osmotic adjustment. Accordingly, genotype dependent capacity could be found using supplemental Ca.  相似文献