Experiential ownership and body ownership are different phenomena.

Body ownership concerns what it is like to feel a body part or a full body as mine, and has become a prominent area of study. We propose that there is a closely related type of bodily self-consciousness largely neglected by researchers-experiential ownership. It refers to the sense that I am the one who is having a conscious experience. Are body ownership and experiential ownership actually the same phenomenon or are they genuinely different? In our experiments, the participant watched a rubber hand or someone else's body from the first-person perspective and was touched either synchronously or asynchronously. The main findings: (1) The sense of body ownership was hindered in the asynchronous conditions of both the body-part and the full-body experiments. However, a strong sense of experiential ownership was observed in those conditions. (2) We found the opposite when the participants' responses were measured after tactile stimulations had ceased for 5 s. In the synchronous conditions of another set of body-part and full-body experiments, only experiential ownership was blocked but not body ownership. These results demonstrate for the first time the double dissociation between body ownership and experiential ownership. Experiential ownership is indeed a distinct type of bodily self-consciousness.

A Long Neglected Damper in the El Niño--Typhoon Relationship: a 'Gaia-Like' Process.

Proposed in the early 1970's, the Gaia hypothesis suggests that our planet earth has a self-regulating ability to maintain a stable condition for life. Tropical cyclone (TC) is one of the earth's most hazardous disasters; it is intriguing to explore whether 'Gaia-like' processes may exist in nature to regulate TC activities. El Niño can shift the forming position of the Western Pacific typhoons away from land. This shift enables typhoons to travel longer distances over ocean and is known to be a positive process to promote TCs to achieve higher intensity. What is neglected, however, is that there co-exists a negative process. Here we show that during El Niño, typhoons intensify over region undergoing strong ocean subsurface shoaling where upper ocean heat content can drop by 20-50%. This 'worsen' ocean pre-condition can effectively reduce ocean's energy supply for typhoon intensification during typhoon-ocean interaction. We find this an elegant, 'Gaia-like' process demonstrating nature's self-regulating ability. Though during El Niño, typhoons can take advantage of the longer travelling distance over ocean to achieve higher intensity, nature is also providing a damper to partially cancel this positive impact. Without the damper, the situation could be even worse.

RNA aptamers generated against oligomeric Abeta40 recognize common amyloid aptatopes with low specificity but high sensitivity.

Aptamers are useful molecular recognition tools in research, diagnostics, and therapy. Despite promising results in other fields, aptamer use has remained scarce in amyloid research, including Alzheimer's disease (AD). AD is a progressive neurodegenerative disease believed to be caused by neurotoxic amyloid beta-protein (Abeta) oligomers. Abeta oligomers therefore are an attractive target for development of diagnostic and therapeutic reagents. We used covalently-stabilized oligomers of the 40-residue form of Abeta (Abeta40) for aptamer selection. Despite gradually increasing the stringency of selection conditions, the selected aptamers did not recognize Abeta40 oligomers but reacted with fibrils of Abeta40, Abeta42, and several other amyloidogenic proteins. Aptamer reactivity with amyloid fibrils showed some degree of protein-sequence dependency. Significant fibril binding also was found for the naïve library and could not be eliminated by counter-selection using Abeta40 fibrils, suggesting that aptamer binding to amyloid fibrils was RNA-sequence-independent. Aptamer binding depended on fibrillogenesis and showed a lag phase. Interestingly, aptamers detected fibril formation with > or =15-fold higher sensitivity than thioflavin T (ThT), revealing substantial beta-sheet and fibril formation undetected by ThT. The data suggest that under physiologic conditions, aptamers for oligomeric forms of amyloidogenic proteins cannot be selected due to high, non-specific affinity of oligonucleotides for amyloid fibrils. Nevertheless, the high sensitivity, whereby aptamers detect beta-sheet formation, suggests that they can serve as superior amyloid recognition tools.

[Association between hypertensive left ventricular hypertrophy and cardiovascular events in adult Beijing residents: a cohort study].

OBJECTIVE: To analyze the impact of hypertensive left ventricular hypertrophy (LVH) on cardiovascular events (CVD) in adult Beijing residents. METHODS: CVD risk factor survey was conducted in 7023 Beijing residents aged 25 - 64 by a stratified-random sample design from 1984 to 1993 in three years interval. CVD events were followed up and the association of the hypertensive LVH and risk of CVD and total death was analyzed by multivariable Cox Regression Model. All subjects were followed up to December 2004. RESULTS: There were 211 non hypertensive LVH patients in the cohort and were excluded from the study. (1) There were 2240 hypertensive patients among 6812 subjects on baseline. The total prevalence of LVH was 11.8% (16.1% in male and 7.5% in female). (2) Compared to the group with normal blood pressure and without left ventricular hypertrophy, subjects with hypertensive LVH had significantly higher risk for acute coronary, acute stroke, total CVD and total death rate. The relative risks (RR) were 4.92 (95% CI: 2.3, 10.7), 4.2 (95% CI: 2.6, 7.0), 4.1 (95% CI: 2.6, 6.3) and 3.3 (95% CI: 2.0, 5.3), respectively. (3) Compared to the group with hypertension and without LVH, the group with hypertensive LVH had also significantly higher risk for acute stroke, total CVD and total death rate. The RR were 1.8 (95% CI: 1.1, 2.8), 1.7 (95% CI: 1.2, 2.3) and 1.7 (95% CI: 1.1, 2.7), respectively. (4) The population attribute risks (PAR) of hypertensive LVH to the incidents of acute CHD, acute stroke, total CVD and total death were 13.0%, 11.0%, 10.4% and 7.9%, respectively. CONCLUSIONS: Hypertensive left ventricular hypertrophy was an independent risk factor for long term risk of cardiovascular events and death.

Aptamer-based endocytosis of a lysosomal enzyme.

Enzyme replacement therapy for lysosomal storage diseases is currently based on endocytosis of lysosomal enzymes via the mannose or mannose 6-phosphate receptors. We are developing a technology for endocytosis of lysosomal enzymes that depends on generic, chemically conjugated reagents. These reagents are aptamers (single-stranded nucleic acid molecules) selected to bind to the extracellular domain of the mouse transferrin receptor. After selection, an RNA aptamer and a DNA aptamer were modified with biotin and linked to dye-labeled streptavidin for detection by confocal microscopy. Aptamer-streptavidin conjugates showed saturable uptake into mouse fibroblasts (Ltk(-) cells), which could be inhibited by an excess of free aptamer but not by tRNA, calf thymus DNA, or transferrin. The RNA aptamer-streptavidin conjugate was mouse-specific, as human cells (293T) did not take it up unless first transfected with the mouse transferrin receptor. Some streptavidin separated from the recycling pathway of transferrin and colocalized with lysosomes. After characterization in the model system, the DNA aptamer was conjugated to a lysosomal enzyme, alpha-l-iduronidase, from which mannose 6-phosphate had been removed. The aptamer had been modified by attachment of terminal glycerol for oxidation by periodate and reaction of the resulting aldehyde with amino groups on the protein. Dephospho-alpha-L-iduronidase-aptamer conjugate was taken up in saturable manner by alpha-L-iduronidase-deficient mouse fibroblasts, with half-maximal uptake estimated as 1.6 nM. Endocytosed enzyme-aptamer conjugate corrected glycosaminoglycan accumulation, indicating that it reached lysosomes and was functional in those organelles. Both uptake and correction were inhibited by unconjugated aptamer, confirming the role of the aptamer in receptor-mediated endocytosis.

Inhibition of heregulin signaling by an aptamer that preferentially binds to the oligomeric form of human epidermal growth factor receptor-3.

Human epidermal growth factor receptor-3 (HER3) is a member of the type I receptor tyrosine kinase family. Several members of this family are overexpressed in various carcinomas. Specifically, HER2 is found to be overexpressed in 20-30% of breast cancers. In contrast to epidermal growth factor receptor or HER2, the kinasedeficient HER3 self-associates readily at low nanomolar concentrations and in the absence of its ligands, various isoforms of heregulin (hrg). Binding of hrg disrupts HER3 oligomerization and leads to the formation of signaling-competent heterodimers, preferentially with HER2. Elevated levels of HER3 contribute to increased drug resistance observed in HER2-overexpressing cells. We have used the SELEX (systematic evolution of ligands by exponential enrichment) methodology to select RNA aptamers against the oligomeric state of the extracellular domains of HER3 (HER3ECD, monomeric molecular mass 82,000 Da). One of the aptamers, A30, binds with high affinity to a limited number of binding sites in the oligomeric state of HER3ECD. Binding of A30 and hrg are not competitive. Instead, the disruption of HER3 oligomers by hrg results in an approximately 10-fold increase in total binding sites, but the newly created binding sites are of lower affinity. High-affinity binding of A30 inhibits hrg-dependent tyrosine phosphorylation of HER2 and the hrg-induced growth response of MCF7 cells. As an example of an aptamer against a large macromolecular protein complex, A30 can serve as a tool for the analysis of receptor interactions and may serve as a lead compound for the development of inhibitors against overexpressed receptor tyrosine kinases in carcinomas.

Transcription inhibition using modified pentanucleotides.

Inhibition of gene expression was recently achieved by targeting the transcriptionally competent open complex using relatively short, pentameric modified oligonucleotides at approximately 60 microM. Corroborative affinity cleavage experiments using the copper complex of a phenanthroline conjugate provided the impetus to synthesize additional analogues containing substituents at the 2'-position of uridine in a derivative of 5'-GUGGA (-4 to +1), with the purpose of inhibiting transcription at lower concentrations. Conjugates of 5'-GUGGA modified at the 2'-position of uridine were convergently synthesized using a recently reported method. Seven analogues based upon the 5'-GUGGA scaffold were tested for their ability to inhibit transcription of the lac UV-5 operon. The conjugate containing a tethered pyrene showed 70% inhibition at 20 microM, and modest inhibition at as low as 5 microM. This is a significant improvement over previously tested pentanucleotides and provides direction for the preparation of a next generation of inhibitors.

Shifts of T4/T8 T lymphocytes from BAL fluid and peripheral blood by clinical grade in patients with pulmonary tuberculosis.

OBJECTIVES: We investigated the shifts of T4/T8 lymphocytes from BAL fluid (BALF) and peripheral blood by the clinical grade of pulmonary tuberculosis (TB), which is determined by factors such as extent of pulmonary involvement, fever, and loss of body weight. MATERIALS AND METHODS: In order to explore these questions, BALF was collected from 45 patients presenting with active pulmonary TB and 14 healthy control subjects. The percentages for T-lymphocyte subpopulations, including CD4(+), CD8(+), and CD3(+) T cells, were measured using two-color flow cytometry. RESULTS: A higher percentage of CD3(+)CD4(+) T lymphocytes, with a relatively lower percentage of CD3(+)CD8(+) T lymphocytes, was revealed for the patients with a higher grade of pulmonary TB, compared to patients with a lower grade of pulmonary TB, resulting in an increased BALF C4(+)/CD8(+) ratio. By contrast, a higher percentage of CD3(+)CD8(+) T lymphocytes with a relatively low percentage of CD3(+)CD4(+) T lymphocytes was demonstrated for these patients with a higher grade of pulmonary TB, resulting in a decreased peripheral blood CD4(+)/CD8(+) ratio. CONCLUSIONS: Our findings suggest that compartmentalization of the CD4(+) T lymphocytes in the infected lungs may occur for patients with higher grades of pulmonary TB.

Site-specific DNA cleavage of synthetic NarL sites by an engineered Escherichia coli NarL protein-1,10-phenanthroline cleaving agent.

The NarL response regulatory protein of Escherichia coli has been engineered by covalent modification with 1,10-phenanthroline (OP) to create a set of site-specific DNA-cleaving agents. This was accomplished by introducing single cysteine amino acid replacements at selected locations within the carboxy-terminal DNA-binding domain in or nearby the helix 8 to helix 9 region of the NarL protein using site-directed mutagenesis. Of 18 modified NarL-OP proteins made, 13 retained the ability to bind DNA as evidenced by gel mobility assays, whereas 10 of the 1,10-phenanthroline-modified proteins also exhibited specific cleavage activity for a synthetic NarL recognition sequence. These DNA-cleaving agents were divided into two groups based on the location of the cleavage sites. The first class set cleaved the DNA nearby the center of a synthetic 7-2-7 sequence composed of two NarL heptamer sites separated by a 2-bp spacer element. The second class cut the DNA at the periphery of the 7-2-7 sequence. The cleavage data are consistent with the ability of two NarL monomers to recognize and bind to the DNA in a head-to-head orientation. A second set of DNA-cleaving agents was constructed using the carboxy-terminal domain of NarL called NarL(C). Similar cleavage patterns were observed whether full-length NarL or NarL(C) was used. The availability of 1,10-phenanthroline-modified NarL and NarL(C) proteins opens up the possibility to explore the position, orientation, and number of NarL recognition sites at E. coli promoters predicted to contain multiple and complex arrangements of NarL-binding sites.