Effects of amino acids and derivatives of cyclic adenosine 3′, 5′-monophosphate on the production of three exoenzymes by Staphylococcus, simulans biovar staphylolyticus

The extracellular protease, endopeptidase, and hexosaminidase produced by $\text{Staphylococcus}\text{,}\text{simulans}\text{biovar}\text{staphylolyticus}$ were neither induced nor repressed by amino acids but required a tryptic digest of casein for their production. Catabolite repression of exoenzyme production by glucose was not affected by exogenous cyclic adenosine 3′, 5′-monophosphate but was partially relieved by di- or monobutyryl derivatives of this compound.     

酸敏感离子通道与脑梗死

急性脑梗死约占全部脑卒中的70%,病死率和致残率高,且极易复发。但目前针对急性脑梗死在时间窗内溶栓、抗凝等治疗手段不能从根本上切实有效地修复受损脑组织,且伴有出血等风险。寻找脑梗死形成发展的原因并予以治疗迫在眉睫。酸中毒是引起缺血性脑损伤的重要机制。大量实验研究表明,酸中毒能加重神经元的缺血性损伤,且其梗死面积与酸中毒的程度直接相关。但缺血产生的酸中毒如何引起神经元损伤的确切机制尚不明确。最近研究发现酸中毒能激活一种在中枢及周围神经中广泛存在的膜通道,即酸敏感离子通道,它对Ca2+通透,能引起细胞内Ca2+超载,同时能激活胞内酶引起细胞内蛋白质、脂类及核酸的降解,加重缺血后脑损伤。本文就酸敏感离子通道1a与脑梗死做一综述。     

HYBRIDIZATION OF PANUS TIGRINUS AND LENTODIUM SQUAMULOSUM

Crosses between monokaryotic isolates of two strains of Lentodium squamulosum and one strain of Panus tigrinus showed complete intercompatibility. Hybrid fruits from crosses between monokaryotic isolates of L. squamulosum and P. tigrinus were uniformly like the P. tigrinus parent. Though both isolates of L. squamulosum showed considerable variability in form, merging toward P. tigrinus, L. squamulosum could always be distinguished from P. tigrinus from hand sections of the hymenophore. The significance of these results as they bear on the problem of inter-relationships between hymenomycetes and gasteromycetes is discussed. L. squamulosum is recognized as variety squamulosus of P. tigrinus.