Studies on the relationship between ploidy level,morphology, the concentration of some phytohormones and the nicotine concentration of haploid and doubled haploid tobacco (Nicotiana tabacum L.) and NICA plants

As compared to doubled haploid plants of the same origin, haploid tobacco plants are characterized by narrow leaves and in these leaves the endogenous concentration of gibberellins was considerably higher than in doubled haploids. This higher GA activity is almost entirely due to elevated levels of polar gibberellins. The same leaf shape as in haploids could be induced by GA₃ sprays to doubled haploids. A similar leaf shape was also observed on tissue culture derived so called NICA plants displaying the morphology of tobacco plants as described by Dudits et al. (1987) from whom the plant material was obtained as a gift. Here, in the leaves of a special strain with narrow lamina again a much higher gibberellin activity was detected than in the leaves of plants of the original tobacco strain. Histochemical determination of the relative DNA content indicated that leaves of NICA were chimaeras containing 1C cells besides cells with higher C values. Obviously, haploidy is somehow related to the endogenous gibberellin activity in tobacco plant material with consequences on the morphological appearance of 1n plants. Comparing some haploid and doubled haploid strains in tissue culture and pot and field experiments in several years apparently the genotype of the plant material is more significant for nicotine concentration than the ploidy level.Abbreviations DW dry weight - FW fresh weight - LSI leaf shape index     

Paleoecologic,temporal, and spatial analysis of early Silurian Reefs of the Chicotte Formation,Anticosti Island,Quebec, Canada

Summary Reefs of the Lower Silurian Chicotte Formation are the largest and most faunally diverse known on Anticosti Island, Quebec. They reach up to 25 m in thickness and 250 m in diameter and are present predominantly at two intervals, forming a lower and upper reef cluster. Remnants of bioherms are represented on the present-day wave-cut terrace as 60 to 100 m diameter, subcircular erosional depressions known as Philip structures or as outcrop. The bioherms were relatively low structures, with approximately 3 to 5 m maximum synoptic relief, some of which developed on hardgrounds and possible paleokarst surfaces of crinoidal wackestone and packstone. Dominant skeletal framework builders and sediment producers within all of the reefs are laminar to low domical stromatoporoids, colonial cerioid and fasciculate rugose corals, colonial tabulate corals, and cryptostome bryozoans. Vertical zonation of reef biota is evident within well-exposed reefs of the lower reef cluster. Three to four stages are recognizable:1) a low-diversity tabulate coral-dominatedpioneering community including large tabulate coral colonies (halysitids and favositids), and few stromatoporoids (clathrodictyids, ecclimadictyids), fasciculate rugosans, large generally monotypic stalked crinoids, and shelly benthos (brachiopods, few ostracodes and trilobites);2) an intermediate- to high-diversity, mixed tabulate coral-stromatoporoid-dominatedreef-core community;3) a slightly lower diversity stromatoporoid-tabulate coral-dominatedclimax community with laminar coenitids and alveolitids; and,4) in a few localities, a capping, low-diversity tabulatecoral-dominated (alveolitid and coenitid), and stromatoporoid-bearing community comprising laminar forms. Amelioration of Early Silurian climates, following Late Ordovician glaciation, allowed gradual reestablishment of extensive shallow-water reef growth, by mainly new and increasingly diverse genera and species of metazoans. Reef development within the Chicotte Formation coincided with global, widespread development of latest Llandovery and earliest Wenlock reefs in subtropical to tropical areas. Chicotte reefs have broad characteristics, in terms of overall biotic composition, vertical successions recognized, and paleogeographic setting, similar to those of equivalent and slightly younger age from intracratonic settings in Baltica (Gotland, Sweden and Estonia) and central and northern Laurentia (Midcontinent, U.S.A.; Hudson Bay, Canada; and North Greenland, Denmark).     

Host-plant effects on Parasyrphus melanderi (Diptera: Syrphidae) feeding on a willow leaf beetle Chrysomela aeneicollis (Coleoptera: Chrysomelidae)

Abstract.

• 1 Generalist predators are repelled by chrysomelid (Chrysomela spp., Phratora vitellinue L.) larval defensive secretions that are obtained from salicin in their host plants. But little is known about the effect of these secretions on specialist predators.
• 2 In this study, we describe the feeding behaviour of a fly, Parasyrphus melanderi Curran (Diptera: Syrphidae), which feeds on Chrysomela aeneicollis Schaeffer (Coleoptera: Chrysomelidae). Parasyrphus melanderi lays its eggs on C.aeneicollis egg clutches, and its larvae consume C.aeneicollis eggs and larvae.
• 3 Chrysomela aeneicollis hatching rates were significantly lower (20%) on clutches with fly eggs than on clutches without them (40%). Half of the clutches with one fly egg had survival rates below 5%, and when two fly eggs were present (four clutches), the entire clutch was consumed.
• 4 In nature, P.melanderi eggs were 3 times more abundant on a salicylaterich willow species S.orestera Schneider, than on the medium-salicylate S.geyeriana Anderss. (1.8 v 0.6 eggs per clutch). On 18% of the S.orestera clones, all the beetle clutches contained fly eggs. In laboratory-choice tests, P.melanderi larvae fed equally rapidly on C.aeneicollis larvae that were chemically defended (feeding on S.orestera) as on larvae that produced no secretion (feeding on the salicylate-poor S.lutea Nutt.). This predator does not appear to be deterred by C.aeneicollis's defensive secretion. We discuss the implications of specialist predators on determining host suitability to herbivorous insects.

     

益肾化瘀汤对糖尿病肾病大鼠肾功能及外周血腺苷脱氨酶表达的影响

摘要 目的：研究益肾化瘀汤对糖尿病肾病（diabetic kidney disease, DKD）大鼠肾功能及外周血腺苷脱氨酶（adenosine deaminase, ADA）表达的影响。方法：将30只大鼠随机分为空白组、模型组和治疗组,每组10只。模型组和治疗组均建立DKD模型,治疗组给予益肾化瘀汤治疗30 d。分别于给药后的第1 d、第10 d、第20 d和第30 d检测各组大鼠的血糖水平、肾功能指标和血清ADA的表达水平,HE染色观察肾组织病理学变化。结果：模型组大鼠出现多饮多尿体重减轻的糖尿病症状,治疗组在给予益肾化瘀汤后上述症状均有所好转。模型组和治疗组的空腹血糖值（fasting blood glucose,FBG）水平均显著高于空白组（P＜0.05）,自第10 d开始治疗组大鼠FBG水平显著低于模型组（P＜0.05）。模型组和治疗组大鼠血清肌酐（serum creatinine, SCr）和血尿素氮（blood urea nitrogen, BUN）的表达水平显著高于空白组（P＜0.05）,自第10 d开始治疗组大鼠的Scr和BUN显著低于模型组（P＜0.05）。模型组和治疗组大鼠血清ADA的表达水平显著高于空白组（P＜0.05）,自第10 d开始治疗组大鼠ADA的表达显著低于模型组（P＜0.05）。结论：益肾化瘀汤可显著改善DKD大鼠的血糖水平、肾功能及血清ADA表达水平,具有一定的临床应用价值。     

改良眼底激光光凝合康柏西普治疗增殖性糖尿病视网膜病变的效果及对视力水平、黄斑区血流密度的影响

摘要 目的：探究改良眼底激光光凝联合康柏西普治疗增殖性糖尿病视网膜病变（PDR）的效果及对视力水平、黄斑区血流密度的影响。方法：回顾性分析2019.06-2022.06于我院接受改良眼底激光光凝治疗的62例（124眼）PDR患者临床资料,纳入对照组,回顾性分析同期于我院接受改良眼底激光光凝联合康柏西普治疗的62例（124眼）PDR患者临床资料,纳入试验组。比较治疗前和治疗后3个月两组患者视力水平[最佳矫正视力（BCVA）、视野指数（VFI）、视野平均缺损（MD）]、视网膜中央动脉血流动力学[峰值血流速度（PSV）、平均血流速度（MV）、搏动指数（PI）、阻力指数（RI）]、黄斑区血流密度[浅层毛细血管丛（SCP）、深层毛细血管丛（DCP）]、生活质量[低视力者生存质量量表（CLVQOL）]差异,记录3个月内两组患者并发症（黄斑水肿、高眼压、视网膜出血）发生情况。结果：治疗后3个月,两组患者BCVA、PSV、MV、SCP、DCP、CLVQOL较治疗前升高,试验组高于对照组（P均<0.05）;而VFI、MD、PI、RI水平降低,试验组低于对照组（P均<0.05）;两组患者术后并发症无显著性差异（P>0.05）。结论：改良眼底激光光凝治疗联合康柏西普治疗可增强PDR患者视力功能,改善患者视网膜中央动脉血流动力学及黄斑区血流密度,提高生活质量。     

Fungal spore swelling and germination are restricted by the macrophage phagolysosome

Many species of medically important fungi are prolific in the formation of asexual spores. Spores undergo a process of active swelling and cell wall remodelling before a germ tube is formed and filamentous growth ensues. Highly elongated germ tubes are known to be difficult to phagocytose and pose particular challenges for immune phagocytes. However, the significance of the earliest stages of spore germination during immune cell interactions has not been investigated and yet this is likely to be important for defence against sporogenous fungal pathogens. We show here that macrophages restrict the early phases of the spore germination process of Aspergillus fumigatus and Mucor circinelloides including the initial phase of spore swelling, spore germination and early polarised growth. Macrophages are therefore adept at retarding germination as well as subsequent vegetative growth which is likely to be critical for immune surveillance and protection against sporulating fungi.     

常见水稻病虫害胁迫对转cry1C基因抗虫水稻Bt蛋白表达量的影响

【目的】明确转Bt基因抗虫水稻在病虫害胁迫下对Bt蛋白表达量的影响。【方法】以Bt水稻T1C-19(表达Cry1C蛋白)为研究对象,探究褐飞虱、白叶枯病等6种水稻常见病虫害胁迫下其体内Bt蛋白的表达量变化。【结果】褐飞虱取食引起T1C-19水稻叶片中Bt蛋白含量降低,而黑尾叶蝉取食显著降低了T1C-19水稻叶鞘中的Bt蛋白含量,白叶枯病侵染导致Bt水稻叶鞘中的Bt蛋白含量显著上升。二化螟、水稻普通矮缩病、稻瘟病的胁迫对转基因水稻T1C-19叶片和叶鞘中的Bt蛋白含量均无显著影响。【结论】病虫害胁迫因种类不同对Bt水稻中Bt蛋白表达量的影响有所不同。这将为Bt水稻的抗虫效果评价提供数据基础,同时为Bt水稻病虫害综合治理提供科学依据。     

Ecdysteroid and juvenile hormone changes in Bombyx mori eggs, related to the initiation of diapause

We describe a method for the routine determination of changes in juvenile hormone levels in insect eggs. The hormones are first converted into their diol derivatives, then they are purified from other lipids and separated by high-performance liquid chromatography (HPLC). The radioimmunoassay of the fractions was then determined. The method permits the simultaneous assay of ecdysteroids, and it was used for determining the hormonal changes in Bombyx eggs during the pre-diapause development. Our major finding is that the hormonal content of eggs dramatically increased prior to the initiation of diapause. This hormonal rise included ecdysone, 20-OH-ecdysone and 3 juvenile hormones. The HPLC retention time of the latter corresponded to JH₁ JH₂ and JH₃. Subsequently, the embryos entered diapause and the hormonal content of eggs was reduced to traces of ecdysteroids. These dramatic changes in juvenile hormone levels during early embryogenesis raise a number of issues which are developed in the discussion.     

Immunodiagnosis of parasitic zoonoses: purification of Toxocara canis antigens by affinity chromatography

A method of affinity chromatography developed for the purification of species-specific antigens from Toxocara canis adult worms is described. Immunochemical analyses by polyacrylamide gel electrophoresis, immunoelectrophoresis and immunodiffusion showed that ‘pure’ antigen contained fewer but more specific proteins than ‘crude’ antigen. Purified antigens and parasite sections from four parasite species (Toxocara canis, Dirofilaria immitis, Angiostrongylus cantonensis and Ascaris lumbricoides) were used in immunofluorescence tests to measure serum antibody levels in animals with natural or experimental T. canis infections and people with zoonotic toxocariasis. ‘Pure’ antigen showed higher specificity and sensitivity than ‘crude’ antigen in serological testing.     

E-rosette receptors induced by phytohemagglutinin on human K cells expressing T-cell surface antigens.

Killer cells (K cells) enriched from human blood mononuclear cells which mediate antibody-dependent cellular cytotoxicity (ADCC) were examined for surface markers. Sixty-seven percent of the E-rosette-negative, sIg-negative cells reacted with anti-T cell serum (AMT) previously shown to react with immunochemically defined T-cell antigens. Phytohemagglutinin induced 25% of K cells to express an E-rosette receptor. When these induced cells were isolated, greater than 98% reacted with AMT and 17% expressed the Fc receptor for IgG. Furthermore, they retained their functional capacity in ADCC. These findings demonstrate that an E-rosette receptor can be induced on human K cells. The data suggest the K-cell fraction included a population of thymus-dependent lymphocytes which can function as effector cells in ADCC.