Toxicity of argemone oil: Effect on hsp70expression and tissue damage in transgenic Drosophila melanogaster(hsp70-lacZ) Bg 9

The effect of argemone oil on hsp70expression and tissue damage was investigated by studying β-galactosidase activity, Western blotting and hybridization, and trypan blue staining in the larval tissues of transgenic Drosophila melanogaster(hsp70-lacZ)Bg ⁹. Different concentrations of argemone oil were mixed with food and third-instar larvae were allowed to feed on them for different time intervals (2, 4, 24, and 48 h). Argemone oil was found to induce hsp70even in the lowest concentration of the adulterant while maximum tissue damage was observed in the higher two treatment groups. Malpighian tubules and midgut tissue reflected maximum damage as evidenced by both high β-galactosidase activity and trypan blue staining in these tissues. A prior temperature shock treatment to the larvae was enough to protect the larvae from argemone oil-induced tissue damage as evidenced by little or no trypan blue staining. The present study suggests the cytotoxic potential of argemone oil and further strengthens the evidence for the use of hsp70as a biomarker in risk assessment. This revised version was published online in August 2006 with corrections to the Cover Date.     

蜡状芽孢杆菌S458-1对水产养殖系统中水质调节的作用

【目的】水产养殖过程中蜡状芽孢杆菌(Bacillus cereus)作为益生菌被广泛应用。本研究旨在深入了解分离于养殖水体中的一株蜡状芽孢杆菌S458-1对养殖水体以及养殖对象的影响,以期为菌株S458-1在水产养殖生产上的应用提供理论依据。【方法】根据控制变量法,各试验组鲫鱼养殖模式设置相同温度、盐度、溶氧和pH,利用分光光度法测定水体的水化学指标;利用试剂盒法测定鲫鱼的血清生理生化指标。【结果】添加菌株S458-1处理组(终浓度分别为10~6、10~7、10~8CFU/mL)与对照组(未加S458-1菌)相比:水体活性磷浓度显著性增加(P0.05);同时具有把NH_4~+-N和NO_2~–-N转化为NO_3~–-N的趋势,但无显著性差异(P0.05);养殖鲫鱼血清检测结果显示谷草转氨酶(GOT)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)以及丙二醛(MDA)含量均显著降低(P0.05)。【结论】蜡状芽孢杆菌S458-1具有脱氮解磷、调节水质的作用,并可增强养殖对象的生理健康状态,可作为益生菌应用于水产养殖中,具有较高的应用价值。     

Quantitative analysis of cytoplasmic actin gene promoter and nuclear polyhedrosis virus immediate-early promoter activities in various tissues of silkworm Bombyx mori using recombinant Autographa californica nuclear polyhedrosis virus as vector

Cassettes harboring luciferase reporter driven by Bombyx mori cytoplasmic actin gene promoter (A3) (671 bp) and B. mori nuclear polyhedrosis virus immediate-early promoter (IE-1) (580 bp) were transferred to the bacmid AcΔEGT to generate the recombinant Autographa californica nuclear polyhedrosis viruses, AcNPVA3Luc and AcNPVIELuc, respectively. Recombinant baculoviruses were injected into the hemocoele of newly ecdysed 5th instar larvae. The activities of the A3 and IE-1 promoters in various tissues were measured by luciferase activity assay and normalized by the copy number of recombinant virus. Results showed that the activity of the A3 promoter was approximately 10-fold higher than the IE-1 promoter. The promoter activities of A3 and IE-1 were highest in the silk gland, followed by fat body, middle gut, Malpighian tubule, and hemocyte. In silk gland, activity of the two promoters was highest in posterior silk gland, followed by middle and anterior silk glands. The difference in promoter activities reflects the growth speed of tissue in silkworm larvae. The activity of the A3 promoter remained unchanged and was not inhibited significantly by viral factors at least 3–4 d post injection of rAcNPV.     

Characterizing and modeling hydrogen sulfide production in anaerobic digestion of livestock manure,agro-industrial wastes,and wastewater sludge

Hydrogen sulfide (H₂S) is the most undesirable inorganic gas in biogas from anaerobic digestion (AD). However, H₂S production in AD is complex and understanding of its processes is still limited. This study performed six controlled batch anaerobic co-digestion experiments to investigate H₂S production. Materials were obtained from four field anaerobic digester systems and co-digestion feedstocks from agroindustry. An additional precipitation experiment was conducted to further examine H₂S production dynamics. Digesters containing highly soluble, carbohydrate-based wastes had a high H₂S final specific production (FSP) value. Additionally, the FSP values were negatively correlated with the initial Fe(II):S ratios in the digester liquid of the batch tests. The precipitation experiment indicated that iron sulfide precipitation was preferred in the presence of an anaerobic community. The H₂S production as a time series was successfully modeled using a generalized additive model (R² > 0.82). This study revealed that sulfate, phosphorus, and iron concentrations are important predictors and potential inhibitors of H₂S production in AD. Further examination of real-time H₂S modeling in AD is warranted.     

Tissue microenvironment and the genetic control of hair pigment patterns in mice

This study was conducted to assess microenvironmental variability within integumental tissue of genetically identical mice with respect to a specific cellular response: cyclic synthesis of yellow and black pigment by hair bulb melanocytes. Crosses were performed within and between inbred strains of mice that were isogenic with the exception of a single gene substitution at the agouti locus. Agouti locus genes included the A^vy, A^w, A, a^td, a^t, a^x, a^m, and a alleles. The pigment patterns of dorsal, flank, and ventral hairs of the first and third hair generations and of hairs growing in special integumentary areas such as the pinna, tail, and hind foot were studied. It was found that the amount of yellow pigment synthesized by hair bulb melanocytes within genetically identical mice is both agedependent and conditioned by the integumentary environment. Furthermore, the special integumentary regions produce hairs with a variety of pigment patterns in which the distribution and relative amounts of black and yellow pigments do not necessarily conform to dominance relationships expected among agouti locus alleles as judged by their effects on the pigmentation of the dorsal pelage. We conclude that within genetically uniform integumental tissues, microenvironmental differences occur and are reflected as alterations in the metabolic pattern of differentiated cells.     

Thrombin attenuation is neuroprotective in the injured rat optic nerve

The functional loss that often follows injury of the mammalian CNS has been attributed not only to the immediate neural loss, but also to secondary neuronal degeneration caused by toxic biochemical mediators in the environment of the injured nerve. We report here that a high thrombin content, produced as a result of injury-induced activation of prothrombin, appears to be an important mediator of secondary damage. Measurement of post-traumatic neuronal survival in vivo revealed that post-traumatic local application of the thrombin inhibitor N-alpha-(2-naphthylsulphonylglycyl)-4-(D,L)-amidinophenylalanine piperidide acetate in the rat optic nerve subjected to mild partial crush injury left twice as many retinal ganglion cells with functioning axons as in controls. Thus, by readjusting thrombin activity, thereby possibly obtaining a moderate post-traumatic increase and thus gaining the benefit of thrombin without its toxic effects, it may be possible to create an environment that is more favourable for post-traumatic survival.     

Adherence of Agrobacterium tumefaciens to the cells of immature wheat embryos

Agrobacterium attached to wheat embryos in vitro. This attachment was plasmid independent, and occurred on both wounded and unwounded cell surfaces. The pattern of attachment clearly demonstrated that bacterial attachment to cereal cells follows the same trends observed for dicotyledonous plants. During the inoculation period the bacterial cells attach to the plant cell walls either with lateral or polar orientation. Wounding (mechanical or enzymatic) preferentially promoted adherence of the bacteria at the wound site, however, attachment was not wound dependent.     

Fabrication of endothelialized tube in collagen gel as starting point for self-developing capillary-like network to construct three-dimensional organs in vitro

A possible strategy for creating three-dimensional (3D) tissue-engineered organs in vitro with similar volumes to the primary organs is to develop a capillary network throughout the constructs to provide sufficient oxygenation and nutrition to the cells composing them. Here, we propose a novel approach for the creation of a capillary-like network in vitro, based on the spontaneous tube-forming activity of vascular endothelial cells (ECs) in collagen gel. We fabricated a linear tube of 500 microm in diameter, the inner surface of which was filled with bovine carotid artery vascular endothelial cells (BECs), in type I collagen gel as a starting point for the formation of a capillary-like network. The BECs exposed to a medium containing vascular endothelial growth factor (VEGF) migrated into the ambient gel around the tube. After 2 weeks of VEGF exposure, the distance of the migration into the ambient gel in the radial direction of the tube reached approximately 800 microm. Cross-sections of capillary-like structures composed of the migrating BECs, with a lumen-like interior space, were observed in slices of the gel around the tube stained with hematoxylin-eosin (H&E). These results demonstrate that this approach using a pre-established tube, which is composed of ECs, as a starting point for a self-developing capillary-like network is potentially useful for constructing 3D organs in vitro.     

In vitro propagation and subsequent nodulation of the actinorhizal Hippophae rhamnoides L.

Micropropagation of the actinorhizal plant Hippophae rhamnoides L. (sea-buckthorn) was achieved on Murashige and Skoog (MS) medium supplemented with 1 M of benzylaminopurine (BA). A multiplication frequency of three to five shoots per explant was observed after 28 days. Rooting of these shoots was achieved in a medium containing 1/4 strength MS without growth regulators. The rooted plants were transferred to Turface R artificial substrate and inoculated with pure cultures of two Frankia strains. These plantlets subsequently developed nodules which fixed nitrogen.     

Cell division study in ‘pollen mother cells’ and ‘pollen grains’ of in vivo and ex vitro plants in Drimiopsis botryoides

The various normal and abnormal stages of meiosis and pollen mitosis of Drimiopsis botryoides are described, and a comparison between naturally propagated in vivo and tissue culture derived ex vitro plants in respect to their cytological behaviour presented. We also describe the floral morphology and investigate the relationship between the floral developmental stages and the progression of microgametogenesis. In total, 33 bivalents are observed in diakinesis, which indicate the diploid number 2n = 66 and this number is cross-checked by a haploid set of n = 33 chromosomes in pollen mitosis. Only 6.8% and 4.9% meiotic abnormalities were recorded on in vivo and ex vitro plants, respectively, which led to the formation of non-viable pollen. Finally, the microspores have to develop into tri-cellular male gametophyte. Only 0.2% pollen grains are found with a micro-nucleus. Though the higher pollen viability was recorded on both in vivo (89.3 ± 4.1%) and ex vitro (92.1 ± 4.6%) plants, but surprisingly the pollen germination rate is extremely low with 13.6 ± 1.74% and 21.3 ± 1.55%, respectively. The present study obviously enriches the cytological database of D. botryoides and may help future research on androgenesis and genetic improvement.