Characterization of a shiitake mutant strain producing ballshaped fruiting bodies

Growth characteristics of a spontaneous mutant of shiitake Lentinula edodes (Berk.) Pegler were studied. The mutant was first detected as a result of changes in the growth habit of the normal strain in the liquid medium. Abundant formation of aerial hyphae was distinctive. In sawdust logs the mutant strain produced abnormal basidiocarps, lacking stipe, gill and spore formation.
Growth rates of the normal and the mutant strain were compared in two liquid media: malt-yeast extract and Leatham's medium. The increase in dry weight of the mutant's mycelium was much higher than that of the wild type in both media, which indicated better adaptation to liquid culture. In the sawdust, however, growth of the mutant was slower than that of the normal strain. The mutant's intracellular protein content was lower than that of the normal strain. The pH of the liquid cultures differed: the wild type decreased the pH during growth, while the mutant increased the pH. Comparison of the protein and esterase isoenzyme profiles of the vegetative hyphae of both strains indicated profound differences. One protein (pI 6.5, 39 kDa), which in earlier studies has been found to be typical of L. edodes species, was absent from the mutant's profile. Differences in the esterase profile were also clear.     

血管生长异常与流产的关系研究进展

微血管密度异常、血管生长因子(VEGF、PDGF等)及其受体表达异常通过一系列级联反应导致血管异常生长的结果。众多因子均和血管形成有关,在妊娠过程中对胎盘的血管发育有着重要的作用,导致滋养细胞的表型转换障碍、血管结构发育不良、血管生成受阻、血管数目减少,引起胎盘血管重铸障碍,胎儿胎盘单位灌注不足发生流产。研究表明许多自然流产的发生与胎盘组织中血管增生平衡和胎儿血液供应不足有密切关系,从而认为血管生长异常是导致流产的又一重要因素。随着研究的深入进展血管的异常生长与流产的关系是有确定关系的,对于血管生长异常所致的流产,抑制血管各种血管因子的形成、阻止其与受体结合,从而抑制血管的异常生长最终达到克服流产的发展,无异于把幸福带给更多的家庭,不仅是妇产科发展的里程碑,更是人类医学发展史上光辉的一笔。     

Notch signaling and Notch signaling modifiers

Originally discovered nearly a century ago, the Notch signaling pathway is critical for virtually all developmental programs and modulates an astounding variety of pathogenic processes. The DSL (Delta, Serrate, LAG-2 family) proteins have long been considered canonical activators of the core Notch pathway. More recently, a wide and expanding network of non-canonical extracellular factors has also been shown to modulate Notch signaling, conferring newly appreciated complexity to this evolutionarily conserved signal transduction system. Here, I review current concepts in Notch signaling, with a focus on work from the last decade elucidating novel extracellular proteins that up- or down-regulate signal potency.     

宫腔镜联合B超诊断异常子宫出血124例临床分析

目的：探讨宫腔镜联合B超在诊治异常子宫出血的临床价值。方法：对124例异常子宫出血的病例进行回顾性分析,所有患者作B超及宫腔镜检查,宫腔内切除物或刮出物均送病理检查。结果：124例患者经病理检查确诊为子宫内膜息肉84例（67．7％）,合并宫颈息肉10例;子宫内膜增生症16例（12．9％）,其中单纯性增生12例,复杂性增生4例;子宫内膜不典型增生1例（0．8％）;子宫粘膜下肌瘤12例（9．7％）;子宫内膜样腺癌6例（4．8％）;子宫内膜炎3例（2．4％）;胚物残留2例（1．6％）。结论：宫腔镜联合B超检查是诊断异常子宫出血最好的方法.     

促进人工饲养实验猕猴心理康乐

目的促进实验猕猴心理康乐,既能减少动物异常行为的发生、获得可靠的科学数据,同时也是实现这一珍贵非人灵长类实验动物福利的重要内容。实验猕猴社会化集群、环境优化、婴猴饲养方式是影响动物心理康乐几个较大的因素,本文对其研究进展进行了综述,对推进我国灵长类实验动物福利具有积极作用。     

Regulation of karyotype stability in tobacco tissue cultures of normal and tumorous genotypes

Summary Callus cultures of Nicotiana glauca, N. langsdorffii and of their tumor-forming hybrid plants contained a high frequency of cells with irregular chromosome numbers and chromosome aberrations (hypo-, hyper-, polyploid, aneuploid cells; bridges, polytene, broken, fragmented chromosomes, megachromosomes, etc.). Meristematic cells of shoot tips regenerated from the same cultures contained only regular chromosome numbers with normal chromosome structures. Variability in chromosome numbers is a consequence of abnormal mitoses. The data suggest genome segregation in the cultures. Cytological instability appears to be independent of genome segregation composition, genotype, tumorous condition, hormonal requirement and level of ploidy. The karyotype stability of the cultures is only dependent on the degree of organization of tissues and is regulated by factors involved in the control mechanisms of organizational processes.     

Hip circumduction is not a compensation for reduced knee flexion angle during gait

It has long been held that hip abduction compensates for reduced swing-phase knee flexion angle, especially in those after stroke. However, there are other compensatory motions such as pelvic obliquity (hip hiking) that could also be used to facilitate foot clearance with greater energy efficiency. Our previous work suggested that hip abduction may not be a compensation for reduced knee flexion after stroke. Previous study applied robotic knee flexion assistance in people with post-stroke Stiff-Knee Gait (SKG) during pre-swing, finding increased abduction despite improved knee flexion and toe clearance. Thus, our hypothesis was that hip abduction is not a compensation for reduced knee flexion. We simulated the kinematics of post-stroke SKG on unimpaired individuals with three factors: a knee orthosis to reduce knee flexion, an ankle-foot orthosis commonly worn by those post-stroke, and matching gait speeds. We compared spatiotemporal measures and kinematics between experimental factors within healthy controls and with a previously recorded cohort of people with post-stroke SKG. We focused on frontal plane motions of hip and pelvis as possible compensatory mechanisms. We observed that regardless of gait speed, knee flexion restriction increased pelvic obliquity (2.8°, p < 0.01) compared to unrestricted walking (1.5°, p < 0.01), but similar to post-stroke SKG (3.4°). However, those with post-stroke SKG had greater hip abduction (8.2°) compared to unimpaired individuals with restricted knee flexion (4.2°, p < 0.05). These results show that pelvic obliquity, not hip abduction, compensates for reduced knee flexion angle. Thus, other factors, possibly neural, facilitate exaggerated hip abduction observed in post-stroke SKG.     

继代十七年的玉米花粉胚性细胞系的异常核和异常分裂观察

对继代17年的玉米花粉胚性细胞系核形态和细胞分裂情况进行了观察分析,结果表明:随着继代培养时间的延长,异形核细胞比率增加,异形核类型和异常分裂增多。分析认为异形核和异常分裂现象出现和增多是导致胚性细胞系分化率降低、异形分化和非整倍体细胞产生的主要原因。并提出来自玉米农家种“八趟白”的部分胚性细胞系能长期保持倍性稳定和胚胎发生并再生,与不断挑选和继代培养中不加2,4-D有关。     

Cadmium-induced abnormality in strains of Euglena gracilis: morphological alteration and its prevention by zinc and cyanocobalamin

Euglena gracilis is susceptible to cadmium (Cd) at high concentrations. There are no comparative data on cytotoxicity or abnormality of CdCl₂ to E. gracilis Z and its achlorophyllous mutant SMZ. The present study examined the cytotoxicity of CdCl₂ under continual exposure at levels ranging from sub-ppm to ppm, and assessed the effects of zinc (Zn) or cyanocobalamin (VB₁₂) supplementation on the suppression of Cd-induced abnormal cell proliferation and hypertrophy. With Zn levels restricted to 1 ppm [as Zn⁺⁺], cell growth of both E. gracilis strains was reduced in proportion to Cd concentration. More abnormal cells (hypertrophied, V-shape and starfish-shape) were observed in both strains at sub-ppm levels of Cd. ZnSO₄ supplementation from 2 to 63 ppm significantly suppressed the incidence of Cd-induced abnormality. However, a significant increase in abnormal cells was observed following Zn supplementation at levels of 125 and 250 ppm, which produced remarkable differences in cell morphology. The incidence of abnormal cells varied with supplemented VB₁₂ levels ranging from 4 to 250 ppb in both E. gracilis strains.     

Development of Abnormal Plantlets and Their Normalization During Cotton Tissue Culture

There was a high frequency in the occurrence of abnormal plantlets during cotton (Gossypium hirsutum L. ) tissue culture. Their patterns, ways of development and effected factors, and the technique of their normalization were studied. Based on their morphologic characters, they could be classified into ten kinds, viz. growing point-abnormal plantlets, cotyledon-, hypocotyl-, united-, fasciculated-, single-leaf-, albino-, vitreous-, browning-, and callus forming plantlets. The growing point- and the cotyledon-abnormal plantlets, which were more commonly seen and were affected by multiple factors, are mainly influenced by the kind of explants, the medium composition, the method and time of culture. The abnormal plantlets could either developed from abnormal embryos or transformed from normal plantlets. Under suitable culture condition reversion of abnormality to normal was possible, however such normalization varied with different genotypes and media. The authors point out the interaction of external regulation and intrinsic developmental mechanism as the main factor causing the accurrence of abnormal plantlet and also discuss the technical procedures of reducing the occurrence frequency of such abnormal plantlets which greatly impact cotton tissue culture.