Studies on the arrangement of glucocorticoid receptors in the plasma membrane of S-49 lymphoma cells.

The presence of glucocorticoid receptors is required for glucocorticoid-mediated lymphocytolysis to take place. However, the explicit mechanism of involvement of this receptor continues to be debated. We have recently presented evidence that this response is mediated by a specialized form of the glucocorticoid receptor that resides in the plasma membrane (mGR). Using sequential cell separation techniques ("immunopanning," fluorescent cell sorting, and soft agar cloning), a resultant population of membrane receptor-enriched cells have remained stable and provided material for further analysis. The mGR patching and capping phenomenon originally observed with fluoresceinated monoclonal antibody techniques was verified here with electron micrographic analysis using colloidal gold-conjugated antibody. Using 3H-labeled monoclonal antibody, a radioimmunoassay for membrane receptors was developed. Trypsin treatment removed the membrane receptor antigenic site from the surface of cells. Peptide mapping of receptor purified from plasma membranes reveals several trypsin and alpha-chymotrypsin cleavage sites. Larger fragments resulted from cleavage of the membrane receptor of cells enriched for mGR versus those found in cells depleted of the membrane form, although most of the resulting fragments are shared by the two forms. Confirmation of previous studies correlating membrane receptor with the mechanism of glucocorticoid sensitivity is now extended to include elimination of the lymphocytolysis effect in membrane receptor-stripped (trypsinized) S-49 cells.     

Species identification of <Emphasis Type="Italic">Ixodes granulatus</Emphasis> (Acari: Ixodidae) based on internal transcribed spacer 2 (ITS2) sequences

To investigate the genetic specificity of Ixodes granulatus ticks collected from Taiwan, the genetic identities and phylogenetic relationships were analyzed by comparing the sequences of the internal transcribed spacer 2 (ITS2) region obtained from 27 strains of ticks representing twelve species of Ixodes. Five major clades can be easily distinguished by neighbour-joining analysis and were congruent by maximum-parsimony method. All these I. granulatus ticks collected from Taiwan and Japan were genetically affiliated to a monophyletic group with highly homogeneous sequences (95.8–99.5% similarity), and can be discriminated from other species and subgenera of Ixodes ticks with a sequence divergence ranging from 13.6% to 62.9%. Moreover, interspecific analysis revealed that four distinct lineages are evident between Ixodes ticks, and all these I. granulatus ticks collected from Taiwan and Japan belong to the same lineage. Our results provide the first investigation on the genetic specificity of I. granulatus ticks, and demonstrate that all these I. granulatus ticks represent a unique lineage distinct from other species and subgenera of Ixodes ticks. The feasibility of ITS2-based genetic analysis for species-specific identification of I. granulatus ticks around East Asia was highly anticipated.     

Novel exploitation of a nuclear function by influenza virus: the cellular SF2/ASF splicing factor controls the amount of the essential viral M2 ion channel protein in infected cells.

We show that a cellular nuclear protein, the SR splicing factor SF2/ASF, controls the level of production of an essential influenza virus protein, the M2 ion channel protein. The M2 mRNA that encodes the ion channel protein is produced by alternative splicing of another viral mRNA, M1 mRNA. The production of M2 mRNA is controlled in two ways. First, a distal (stronger) 5' splice site in M1 mRNA is blocked by the complex of viral polymerase proteins synthesized during infection, allowing the cellular splicing machinery to switch to the proximal (weaker) M2 5' splice site. Second, utilization of the weak M2 5' splice site requires its activation by the cellular SF2/ASF protein. This activation is mediated by the binding of the SF2/ASF protein to a purine-rich splicing enhancer sequence that is located in the 3' exon of M1 mRNA. We demonstrate that activation of the M2 5' splice site is controlled by the SF2/ASF protein in vivo during influenza virus infection. Utilizing four cell lines that differ in their levels of production of the SF2/ASF protein, we show that during virus infection of these cell lines both M2 mRNA and the M2 ion channel protein are produced in amounts that are proportional to the different expression levels of the SF2/ASF protein.     

Prolonged Cerebral Circulation Time Is the Best Parameter for Predicting Vasospasm during Initial CT Perfusion in Subarachnoid Hemorrhagic Patients

Purpose

We sought to imitate angiographic cerebral circulation time (CCT) and create a similar index from baseline CT perfusion (CTP) to better predict vasospasm in patients with subarachnoid hemorrhage (SAH).

Methods

Forty-one SAH patients with available DSA and CTP were retrospectively included. The vasospasm group was comprised of patients with deterioration in conscious functioning and newly developed luminal narrowing; remaining cases were classified as the control group. The angiography CCT (XA-CCT) was defined as the difference in TTP (time to peak) between the selected arterial ROIs and the superior sagittal sinus (SSS). Four arterial ROIs were selected to generate four corresponding XA-CCTs: the right and left anterior cerebral arteries (XA-CCT_RA2 and XA-CCT_LA2) and right- and left-middle cerebral arteries (XA-CCT_RM2 and XA-CCT_LM2). The CCTs from CTP (CT-CCT) were defined as the differences in TTP from the corresponding arterial ROIs and the SSS. Correlations of the different CCTs were calculated and diagnostic accuracy in predicting vasospasm was evaluated.

Results

Intra-class correlations ranged from 0.96 to 0.98. The correlations of XA-CCT_RA2, XA-CCT_RM2, XA-CCT_LA2, and XA-CCT_LM2 with the corresponding CT-CCTs were 0.64, 0.65, 0.53, and 0.68, respectively. All CCTs were significantly prolonged in the vasospasm group (5.8–6.4 s) except for XA-CCT_LA2. CT-CCT_A2 of 5.62 was the optimal cut-off value for detecting vasospasm with a sensitivity of 84.2% and specificity 82.4%

Conclusion

CT-CCTs can be used to interpret cerebral flow without deconvolution algorithms, and outperform both MTT and TTP in predicting vasospasm risk. This finding may help facilitate management of patients with SAH.     

A HIF-1 target, ATIA, protects cells from apoptosis by modulating the mitochondrial thioredoxin, TRX2

The regulation of apoptosis is critical for controlling tissue homeostasis and preventing tumor formation and growth. Reactive oxygen species (ROS) generation plays a key role in such regulation. Here, we describe a HIF-1 target, Vasn/ATIA (anti-TNFα-induced apoptosis), which protects cells against TNFα- and hypoxia-induced apoptosis. Through the generation of ATIA knockout mice, we show that ATIA protects cells from apoptosis through regulating the function of the mitochondrial antioxidant, thioredoxin-2, and ROS generation. ATIA is highly expressed in human glioblastoma, and ATIA knockdown in glioblastoma cells renders them sensitive to hypoxia-induced apoptosis. Therefore, ATIA is not only a HIF-1 target that regulates mitochondrial redox pathways but also a potentially diagnostic marker and therapeutic target in human glioblastoma.     

On the nomenclature of Chinese drug “Cangzhu”

This paper is the documentation of specimens and literature reffered to Atractylodes lancea (Thunb.) DC. etc. As a result, it is found that, in taxonomy of the genus Atractylodes, what represcents by four long-established names, i. e. Atractylodes lancea (Thunb.) DC., A. ovata (Thunb.) DC., A. chinensis (Bunge) Koidz. and A. lyrata Sieb. et Zucc., in fact, is the one and same species. According to the law of priority in nomenclature, the first name should be given to Chinese drug “Cangzhu”, while theother three names have to be treated as its synonyms.     

Synthesis of the spin-labeled derivative of an ether-linked phospholipid possessing high antineoplastic activity.

We report here the complete synthesis of the spin-labeled derivative of an antitumor ether phospholipid, 1-O-octadecyl-2-O-(4'-doxylpentyl)-rac-glycerol-3-phosphocholine. This also represents the first time that the synthesis of a nitroxide spin-labeled diether phospholipid is described. In vitro experiments showed that at micromolar concentrations, this new analog is readily incorporated into the plasma membranes of human HL60 and mouse E8/AK.D1 leukemic cells, and subsequently kills the cells. The availability of this new probe should permit the electron spin resonance spectroscopic approach to investigate ways by which anti-tumor ether phospholipids selectively destroy the tumor cells.