Multiple species of ornithine decarboxylase in rat tissues: Effects of dexamethasone

Several species of ornithine decarboxylase were separated by chromatography of rat thymus and kidney extracts on DEAE-Sepharose CL-6B. One major and one minor species were absent from thymus of rats two hours after hormone treatment but otherwise, the elution profile was identical to thymus from control animals. The elution patterns of ODC activity in kidneys of rats treated 2.5 or 5 hours before sacrifice with dexamethasone differ from that of control kidney and from each other. Enzyme from kidneys early after hormone treatment is eluted earlier than enzyme from control tissue, while at 5 hours, the enzyme is eluted much later than in the control. This suggests that the hormone-induced activity is subsequently modified.     

PET-CT在非完全实性肺结节中的应用价值

肺癌在中国恶性肿瘤的发病率位居第一,随着低剂量薄层CT在肺癌筛查中的广泛应用,临床发现更多表现为非完全实性结节的肺腺癌,目前众多研究使CT影像学特征和肺腺癌病理的关系得到更进一步的认知,虽然CT能对部分非完全实性结节做出定性和定位诊断,但仍有部分非完全实性结节诊断困难,PET-CT结合了病灶的代谢信息和精确的定位信息,从而提高对肺部结节诊断的敏感性、特异性、准确性,综合多个文献PET-CT在非完全实性结节中的诊断分期价值较CT无明显提升,却在评估预后和制定合适手术方案上可以起到一定的作用,本文就PET-CT在SSN中的应用价值进行阐述。     

Intraspecific cross-protection in mice immunized with irradiated Schistosoma mansoni cercariae

Several laboratory-maintained strains of Schistosoma mansoni were tested for their relative immunogenicity or susceptibility to anti-schistosome immunity in irradiated cercaria-immunized mice. A total of 11 strains and substrains were used; 7 were of Puerto Rican origin, 3 from Brazil, and 1 from Egypt. Mice were immunized by percutaneous exposure to 50-krad-irradiated cercariae. Immunity was assessed following challenge with cercariae of the homologous or a heterologous strain. The results showed that the choice of either the challenge or immunizing strains was not critical in the development of significant levels of protection. Extensive degrees of cross-protection developed in all intrastrain combinations tested.     

The genetic variation of compatibility in Biomphalaria glabrata and Schistosoma mansoni

Interactions between different Biomphalaria glabrata stocks and Schistosoma mansoni strains were studied. A series of inbred stocks of B. glabrata were characterized as to genetic variations in susceptibility at different ages to a series of different S. mansoni strains. A series of inbred strains of S. mansoni were characterized as to genetic variations in infectivity for B. glabrata stocks at different ages. Also described is a process of selection for substrains from a single S. mansoni isolate that differ genetically in snail infectivity.