太平洋日本沿岸斑点原海豚的年龄鉴定与生长

本文利用改良的石蜡包埋切片染色技术,对太平洋日本沿岸收集到的286头斑点原海豚(Stenella attenuata)的牙齿标本进行了年龄鉴定,定义了斑点原海豚的牙齿质和牙骨质生长层组(GLGs)。从年龄和生长的角度对斑点原海豚的一些种群生物学特征进行了分析,并推算了部分种群参数。斑点原海豚在约18龄时,牙齿质停止生长,牙髓腔封闭。牙齿质中计数到的GLGs最多为18层,牙骨质中计数到的最多为42层。斑点原海豚的年龄与生长在一定范围内遵循一定的幂函数关系。5—6龄以前,斑点原海豚生长迅速,雌雄生长无明显差异。8—14龄之间,雄性的生长快于雌性。雌性约17龄时达到饱和体长191cm,雄性约22龄达到饱和体长201cm[动物学报51(3)：476-485,2005]。     

SPECIES-SPECIFIC ADHESION OF SPERMATOZOA TO THE SURFACE OF FIXED EGGS IN SEA URCHINS

When the spermatozoa of sea urchins are added to eggs which have been fixed with glutaraldehyde and washed thoroughly, the spermatozoa swarm around the eggs and adhere to the egg surface. The mode of sperm adhesion to the fixed egg is assumed, on the evidence of electron-microscopical studies, to be the same as that of adhesion to the intact egg at the initial stage of normal fertilization. The spermatozoa and fixed eggs of five species of sea urchins were combined and heterologous crosses were studied. Species-specific adhesion of sperm to fixed eggs was clearly demonstrated. There is a direct relationship between the cross-fertilization of living gametes and the binding capacity of spermatozoa and fixed eggs in so far as the employed five species are concerned.     

中国的石叶技术

在旧石器时代晚期,中国北方的地域性石器工业之中也有石叶技术。最典型的实例是山西峙峪的,其特征是:1)制作技术简单;2)生产小型—中型石叶;3)石料的材料较好;4)在技术体系当中的作用较低。根据这些特征的有无,可以将中国北部的石叶技术划分为许家窑以前的阶段、许家窑阶段(10—3.5万年前)、峙峪—小南海阶段(3.5—1.7万年前)这样3个阶段。本文主张这3个阶段分别相当于欧亚大陆西部的旧石器时代早、中、晚期。     

Pigmented Human Skin Equivalent: New Method of Reconstitution by Grafting an Epithelial Sheet Onto a Non-Contractile Dermal Equivalent

We have established a new protocol for reconstituting a pigmented human skin equivalent (PSE) and have evaluated its functional responses to environmental stimulus, UVB. The PSE is reconstituted by grafting an epithelial sheet consisting of keratinocytes and melanocytes onto a porous non-contractile dermal equivalent populated with mitotically and metabolically active fibroblasts. i) The PSE has a multilayered, well-differentiated epidermis with cuboidal basal cells and highly organised dermis with newly synthesised extracellular matrix components. ii) Ki67-positive proliferating keratinocytes (18.1 ± 7.4%) were detected on the basal layer of the epidermis. iii) Melanocytes located exclusively within the basal layer were detected by monoclonal antibody against tyrosinase-related protein (TRP-1). iv) After exposure to UVB (100 mJ/cm² per day) for 7 consecutive days, the intensity of TRP-1 staining was increased in the PSE, showing their functional state, whereas the number of melanocytes was not changed. This non-contractile and functioning new PSE is potentially useful as a model for studying the role of melanocyte-keratinocyte-fibroblast interactions in photoprotection of the skin in more complex cutaneous microenvironment than monolayer culture, and for developing in vitro disease models and therapeutic protocols with genetically altered cells both in epidermis and dermis.     

Allosteric Properties of Acetylcholinesterase

SEVERAL reports^1–3 have suggested that cholinergic ligands bind to acetylcholinesterase at sites distinct from the active centre. Changeux et al.⁴ demonstrated that acetylcholine binds to non-catalytic sites as well as to the active centre of the enzyme. Atropine arid 1-hyoscyamine have also been shown to interact with the enzyme at a region distinct from the active site^{5, 6}. We have therefore investigated whether acetylcholine and atropine are bound to the same site and whether this site is related to the acetylcholine receptor.