Therapeutic efficacy of Stephania tetrandra S. Moore for treatment of neovascularization of retinal capillary (retinopathy) in diabetes--in vitro study.

The present study was designed to examine therapeutic efficacy of the root extract of Stephania Tetrandra S. Moore (STMS) (traditional Chinese medicine; Han Fang Ji) for treatment of neovascularization of the retinal capillary (retinopathy) in streptozotocin (STZ)-induced diabetic rats (STZ diabetic rats) in culture. Recently we have established the culture system in which fetal bovine serum (FBS) in Dulbecco modified Eagle medium (DMEM) induced neovascularization of the retinal capillary and choroidal capillary in normal rats in culture. STZ diabetic rats showed more neovascularization of the retinal capillary and choroidal capillary than did normal rats in culture. In this study, the retinal tissue was removed for the posterior ocular region and cultured in DMEM containing FBS. The choroidal tissue of the posterior ocular region was also removed and cultured as an internal reference. Administration of STSM (0.91, 9.1 and 91 microg/ml) significantly suppressed neovascularization of the retinal capillary in both STZ diabetic rats and normal rats in a dose-dependent manner. Similar results were obtained with the choroidal capillary; administration of STSM suppressed neovascularization of the choroidal capillary in both STZ diabetic rats and normal rats. In order to determine the component of STSM inhibiting neovascularization of the retinal capillary, tetrandrine (a major chemical constituent of STSM) was administered and neovascularization of the retinal capillary was examined in culture. The effect of tetrandrine on the choroidal capillary was also examined as an internal reference. Administration of tetrandrine (0.1, 1.0 and 10 microM) suppressed neovascularization of the retinal capillary in both STZ diabetic rats and normal rats in a dose-dependent manner. Similar results were obtained with the choroidal capillary of both STZ diabetic rats and normal rats. We infer, therefore, that STSM has a direct effect on the retinal capillary of posterior ocular region and suppresses neovascularization of retinal capillary in STZ diabetic rats through the activation of tetrandrine. These results suggest that STSM may prevent for delay the progression of retinopathy in diabetic patients.     

Active compounds in Populus nigra L. wilted leaves responsible for attracting Helicoverpa armigera (Hübner) (Lep., Noctuidae) and new agaropectin formulation

Abstract:  The leaf extracts of Populus nigra were collected and identified by steam distillation, air entrainment and gas chromatographic–mass spectrometric analysis. Electroantennograms were recorded from Helicoverpa armigera adults in response to the chemicals identified. Both aromatic compounds and green-leaf volatiles elicited strong responses. Field experiments revealed that the active compounds responsible for attracting H. armigera moths are mainly short-side-chain aromatic alcohols and aldehydes. We, for the first time, used agaropectin as the controlled-release matrix of insect attractants. A five-component lure containing all the aromatics without phenolics, mixed in the proportions as found in the steam distillate of the leaves collected in August, produced the best trap catch. The results showed that the volatiles of wilted leaves of P. nigra can attract H. armigera adults by feeding attraction.     

Pre‐copulation intervals,copulation frequencies,and initial progeny sex ratios in two biotypes of whitefly,Bemisia tabaci

The whitefly Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) is a species complex, and its systematic classification requires controlled crossing experiments among its genetic groups. Accurate information on pre‐copulation intervals, copulation frequencies, and initial frequency of egg fertilization of newly emerged adults is critical for designing procedures for collecting the virgin adults necessary for these experiments. In the literature, considerable variation is reported between B. tabaci populations, with respect to the length of the pre‐copulation interval and the initial frequency of egg fertilization. Here, we used a video‐recording method to observe continuously the copulation behaviour of the Mediterranean/Asia Minor/Africa (B biotype) and the Asia II (ZHJ1 biotype) groups of B. tabaci. We also recorded the initial frequency of egg fertilization, as determined by the sex of the progeny. When adults were caged in female–male pairs on leaves of cotton plants, the earliest copulation events occurred 2–6 h after emergence; at 12 h after emergence 56–84% of the females had copulated at least once, and nearly all (92–100%) had copulated at least once by 36 h after emergence. Both females and males copulated repeatedly. Approximately 80 and 20% of copulation events occurred during the photophase and scotophase, respectively. By 72 h post‐emergence, the females of the B and ZHJ1 biotypes had copulated on average 6.1 and 3.9 times, respectively. When adults were caged in groups on plants 1–13 h after emergence, 30–35% of the eggs deposited during this period were fertilized, and approximately 90% of females were fertilized by the end of the 13 h. Although timing of copulation differed in detail between the two genetic groups, the results demonstrate that B. tabaci adults can start to copulate as early as 2–6 h post‐emergence and the majority of females can become fertilized on the day that they emerge.     

Iron plaque enhances phosphorus uptake by rice (Oryza sativa) growing under varying phosphorus and iron concentrations

Both solution culture and pot experiments were performed to investigate (a) the effects of external Fe (II) concentrations and forms on the formation of iron plaque on the roots of rice (Oryza sativa) and subsequent P adsorption on iron plaque and shoot P concentrations and (b) the effects of soil moisture regimes on the formation of iron plaque and P adsorption on root surfaces and P accumulation in shoots. The results showed that iron plaque was significantly increased with increasing Fe²⁺ concentrations in the solution culture. The amounts of P adsorbed on the iron plaque were increased significantly with external Fe²⁺ concentrations. Although shoot P concentration was not significantly affected by Fe²⁺ treatment after incubation for 2 days, it was significantly increased in the Fe‐treated plants compared with Fe‐deprived ones after incubation for 4 days. Soil culture experiment showed that the formation of iron plaque on root surfaces was promoted by exogenous iron, with greater amount of iron plaque being formed by addition of ferric hydroxide than of ferric oxide. Phosphorus adsorption on iron plaque also increased with the addition of iron oxides, and increasing soil P increased the amounts of P associated with the iron plaque and shoot P concentration. The amounts of iron plaque were almost sixfold higher under flooding condition than under field capacity condition. Plants pretreated under flooding condition generally had higher shoot P concentrations when they were transplanted to solutions with varying P levels, and this was most pronounced in the treatment with highest solution P concentration. The results suggest that iron plaque acts as a nutrient reservoir for phosphorus in the rhizosphere and helps enhance P acquisition by rice.     

Bayesian image processing of data from constrained source distributions—II. valued,uncorrelated and correlated constraints

Bayesian image processing formalisms which incorporatea priori information about valued-uncorrelated and valued-correlated (patterned) source distributions are introduced and the corresponding iterative algorithms are derived using the EM technique. Striking improvement in image processing is demonstrated when applying these algorithms to Poisson and Gaussian randomized data in one-dimensional cases.     

Changing Activity of Glucose-6-Phosphate Dehydrogenase from Pea Chloroplasts during Photosynthetic Induction

Light inactivation of glucose 6-phosphate dehydrogenase is rapid and occurs before photosynthetic O₂ evolution is measureable in intact chloroplasts. Likewise, dark activation is rapid. The major light induced change in the kinetic parameters of glucose 6-phosphate dehydrogenase is in maximal velocity.     

Plant regeneration from cultured immature embryos of Sorghum bicolor (L.) Moench

Summary Immature embryos of 20 sorghum genotypes were cultured on MS 5 medium containing MS mineral salts supplemented with 2,4-D, zeatin, glycine, niacinamide, Ca-pantothenate, L-asparagine, and vitamins. For regeneration, calli were transferred onto the same medium with the exception that IAA was substituted for 2,4-D. In general, immature embryos obtained 9–12 days after pollination resulted in the best redifferentiation. Ability of calli to regenerate varied among genotypes; cultivars C401-1 and C625 had the highest redifferentiation frequencies. Ability to redifferentiate was heritable and acted as a dominant trait. At least two gene pairs were involved. Regenerated R₀ plants were planted in a greenhouse and their selfed (R₁ and R₂) progenies were planted in the field and examined for morphological and cytological variations. The majority of the phenotypic variations noted in R₀ were not transmitted to later generations. However, variants for plant height, degree of fertility, and midrib color persisted in R₁ and R₂ generations. A variation in tallness was attributable to one dominant mutant gene. Short stature and male sterility variants appeared to be consequences of recessive mutant genes controlling those traits. Minor variations in peroxidase banding patterns were found among R₀ plants.This study was supported by a research grant from Kansas Sorghum Commission and by a Research Fellowship to the senior author from the Ministry of Agriculture, Animal Husbandry, and Fisheries, China. Contribution 86-456-J from the Kansas Agricultural Experiment Station     

重楼属两种植物种子及其附属结构的发育

重楼属两种植物(五指莲Paris axialis和滇重楼Paris polyphylla var.yunnanensis)种子发育的过程基本一致。双受精发生于授粉后10—15天。胚乳为沼生目型。种子发育延续的时间约为150—170天。胚胎发育终止于球形或稍有分化的阶段。种子具二层种皮。 二种重楼种子成熟时的外部形态显著不同。五指莲Paris axialis的种子呈浅棕黄色,长椭圆形,部分为绿白色海绵质假种皮所包裹。假种皮由珠柄发育而来,呈楔形。滇重楼Parispolyphylla var.yunnanensis的种子鲜红色,不规则圆形,外种皮肉质多浆。无假种皮。珠柄橙黄色,短而纤细。     

Two integral membrane proteins located in the cis-middle and trans-part of the Golgi system acquire sialylated N-linked carbohydrates and display different turnovers and sensitivity to cAMP-dependent phosphorylation

The localization and chemical characteristics of two Golgi integral membrane proteins (GIMPs) have been studied using monoclonal antibodies. The two proteins are segregated in different parts of the Golgi system and whereas GIMPc(130 kD) is located in the cis and medial cisternae, GIMPt (100 kD) is confined in the trans-most cisterna and trans-tubular network. Both GIMPs are glycoproteins that contain N- and O-linked carbohydrates. The N-linked carbohydrates were exclusively of the complex type. Although excluded from the trans-side of the Golgi system, where sialylation is believed to occur, GIMPc acquires sialic acid in both its N- and O-linked carbohydrates. Sialic acid was also detected in the N-linked carbohydrates of GIMPt. GIMPc is apparently phosphorylated in the luminal domain in vivo. Phosphorylation occurred exclusively on serine and was stimulated by dibutyryl cyclic AMP. GIMPc and GIMPt displayed half-lives of 20 and 9 h, respectively.     

白兰瓜果实输入~(14)C-葡萄糖的转化与蔗糖合成

~(14)C 追踪试验结果表明,白兰瓜幼果中输入的~(14)C-葡萄糖,50%以上转化为稀酸水解和稀酸不水解的结构物质;果实发育后期,输入后48小时,在果肉和种子中分别只有18%和32%的~(14)C 参入结构物质。根据醇溶性糖的纸层析鉴定,幼果薄片渗入的~(14)C-葡萄糖仅转化为果糖,而发育后期果实则更多转化为蔗糖。显然,幼果的代谢模式是使物质和能量导向结构物质的形成;而后期果实生长已基本停止,物质代谢的方向又转向蔗糖合成的轨道上来。蔗糖合成底物试验结果表明,供给幼果不同底物都只有很低的蔗糖合成活性;发育后期果实供给UDPG+F-6-P 底物时可测出较高的蔗糖合成活性,初步推测白兰瓜中蔗糖合成主要是通过蔗糖磷酸酯合成酶来实现的。