Stress platelets in normal individuals and patients with idiopathic thrombocytopenic purpura.

To test the hypothesis that stress platelets (SPs) described by Tong et al. in rats may be a parameter of young platelets in humans, we examined and characterized SPs in normal individuals and in patients with idiopathic thrombocytopenic purpura (ITP). Our results indicated that SPs comprise about 1.2% of the circulating platelets in normal individuals and 2.6% in ITP patients. The configuration of SPs as well as of various irregular forms of circulating platelets was found to be supported by synergism of both the platelet microfilaments and microtubules. SPs showed some segmentation, the degree of which was similar in normal individuals and ITP patients, and they underwent further segmentation during in vitro incubation, mainly promoted by microtubules, so that they sometimes appeared like discoid platelets in a chain. These observations suggest a new mode of production of discoid platelets in the circulation. Thus, identification and enumeration of SPs may be useful for evaluating thrombocytopoiesis in humans.     

Inter-annual variation in the response of leaf-out onset to soil moisture increase in a teak plantation in northern Thailand

To understand the impact of inter-annual climate change on vegetation-atmosphere mass and energy exchanges, it has become necessary to explore changes in leaf-out onset in response to climatic fluctuations. We examined the response of leaf-out and transpiration onset dates to soil moisture in a teak plantation in northern Thailand based on a 12-year leaf area index and sap flow measurements. The date of leaf-out and transpiration onset varied between years by up to 40 days, and depended on the initial date when the relative extractable water in a soil layer of 0–0.6 m (Θ) was greater than 0.2 being consistent with our previous results. Our new finding is that the delay in leaf-out and transpiration onset relative to the initial date when Θ?>?0.2 increases linearly as the initial date on which Θ?>?0.2 becomes earlier. The delay spans about 20 days in years when Θ?>?0.2 occurs in March (the late dry season)—much earlier than usual because of heavy pre-monsoon rainfalls—while there is little delay in years when Θ?>?0.2 occurs in May. This delay indicates the influence of additional factors on leaf-out onset, which controls the delay in the response of leaf-out to soil moisture increase. The results increased our knowledge about the pattern and extent of the changes in leaf phenology that occur in response to the inter-annual climate variation in tropical regions, where, in particular, such research is needed.     

Endogenous thiol protease inhibitor from rat liver

A thiol protease inhibitor was purified from rat liver by a rapid procedure involving heat treatment of the post-lysosomal fraction, affinity chromatography on papain-Sepharose 4B and Sephadex G-75. The purified inhibitor appeared homogeneous on sodium dodecyl sulfate electrophoresis. The inhibitor had a molecular weight of about 11,500 and consisted of three forms (pI 4.9, 5.2 and 5.6). The preparation inhibited thiol proteases, such as papain, cathepsin H, cathepsin B and cathepsin L, but not serine proteases (trypsin, chymotrypsin, mast cell protease and cathepsin A) or cathepsin D.     

Grouping of isolates in AG 2 ofRhizoctonia solani by total cellular fatty acid analysis

Total-cellular fatty acid compositions of 34 isolates ofRhizoctonia solani belonging to intraspecific groups (ISGs) of anastomosis group (AG) 2, i.e., AG 2-1, AG 2-2 IIIB (mat rush), AG 2-2 IV (sugar beet), AG 2-2 LP (turfgrass), and AG 2–3 (soybean), were compared. The major fatty acids identified were palmitic, stearic, and oleic acids. Principal component analysis based on the percentage composition of total cellular fatty acids revealed consistently low variability among isolates of a single ISG of AG 2. Average linkage cluster analysis showed that isolates obtained from turfgrass representing a newly proposed group, AG 2-2 LP, were differentiated from other AG 2 ISGs. Isolates of another newly proposed group AG 2–3, from diseased soybean were also closely related to AG 2-1 and AG 2-2 IIIB but distinguishable from the AG 2-1 and AG 2-2 LP isolates by the average linkage cluster analysis. These results suggested that the percentage composition of total-cellular fatty acids is a distinct characteristic for the five ISGs belonging to AG 2, and fatty acid analysis is useful for the differentiation and characterization of these ISGs of AG 2 inR. solani.