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1.  Genetic variation in the GSTM3 promoter confer risk and prognosis of renal cell carcinoma by reducing gene expression 
Tan, X | Wang, Y | Han, Y | Chang, W | Su, T | Hou, J | Xu, D | Yu, Y | Ma, W | Thompson, T C | Cao, G
British Journal of Cancer  2013;109(12):3105-3115.
Glutathione S-transferase mu 3 (GSTM3) has been proven to be downregulated in renal cell carcinoma (RCC). We aimed to characterise the role of GSTM3 and its genetic predisposition on the occurrence and postoperative prognosis of RCC.
The effect of GSTM3 on RCC aggressiveness was examined using transfection and silencing methods. Glutathione S-transferase mu 3 expression in renal tissues was examined by immunohistochemistry. The associations of rs1332018 (A-63C) and rs7483 (V224I) polymorphisms with RCC risk were examined using 400 RCC patients and 802 healthy controls. The factors contributing to postoperative disease-specific survival of RCC patients were evaluated using the Cox proportional hazard model.
Glutathione S-transferase mu 3 silencing increased the invasion and anchorage-independent growth of RCC cell lines. rs1332018 (AC+CC vs AA), which correlated with low expression of GSTM3 in kidney, was associated with RCC risk (odds ratio, 1.446; 95% confidence interval (CI), 1.111–1.882). rs1332018 variants and low GSTM3 expression significantly predicted unfavourable postoperative survivals of RCC patients (P<0.05). rs1332018 variants independently predicted a poor prognosis (hazard ratio, 2.119; 95% CI, 1.043–4.307).
Glutathione S-transferase mu 3 may function as a tumour suppressor in RCC. rs1332018 genetic variants predispose the host to downregulating GSTM3 expression in kidney, facilitate carcinogenesis, and predict an unfavourable postoperative prognosis of RCC.
PMCID: PMC3859948  PMID: 24157827
renal cell carcinoma; GSTM3; polymorphism; risk; prognosis
2.  Angle-resolved Photoemission Spectroscopy Study on the Surface States of the Correlated Topological Insulator YbB6 
Scientific Reports  2014;4:5999.
YbB6 is recently predicted to be a moderately correlated topological insulator, which provides a playground to explore the interplay between correlation and topological properties. With angle-resolved photoemission spectroscopy, we directly observed almost linearly dispersive bands around the time-reversal invariant momenta and with negligible kz dependence, consistent with odd number of surface states crossing the Fermi level in a Z2 topological insulator. Circular dichroism photoemission spectra suggest that these in-gap states possess chirality of orbital angular momentum, which is related to the chiral spin texture, further indicative of their topological nature. The observed insulating gap of YbB6 is about 100 meV, larger than that found by theoretical calculations. Our results present strong evidence that YbB6 is a correlated topological insulator and provide a foundation for further studies of this promising material.
PMCID: PMC4126005  PMID: 25102781
3.  Telomerase reverse transcriptase inhibition stimulates cyclooxygenase 2 expression in cancer cells and synergizes with celecoxib to exert anti-cancer effects 
British Journal of Cancer  2013;108(11):2272-2280.
Telomerase and telomerase reverse transcriptase (hTERT) confer cancer cells sustained proliferation and survival potentials. Targeting telomerase or hTERT is a novel anti-cancer strategy. However, telomerase/hTERT inhibition alone has minimal clinical efficacy. We explored the relationship between hTERT and cyclooxygenase 2 (COX2) and evaluated synergistic anti-cancer effects of targeting both hTERT and COX2.
hTERT was depleted in gastric and cervical cancer cells using small interfering RNA (siRNA) and analysed for COX2 expression using quantitative PCR and immunoblotting. Viable cells and apoptotic cells in gastric cancer cells treated with hTERT siRNA or/and the COX2 inhibitor celecoxib were measured using Trypen blue exclusion and flow cytometry. The in vivo anti-cancer effect of hTERT depletion or/and celecoxib was evaluated using mouse xenograft models.
Knocking down hTERT expression in cancer cells led to robust increases in mRNA and protein levels of COX2. The COX2 promoter activity increased substantially in hTERT-depleted cells. hTERT depletion led to the activation of p38 mitogen-activated protein kinase responsible for the stimulation of COX2 gene transcription. hTERT depletion or celecoxib alone did not affect cancer cell survival, whereas their combination synergistically killed them both in vitro and in vivo.
hTERT induces COX2 expression and simultaneously targeting hTERT and COX2 synergistically kills cancer cells.
PMCID: PMC3681031  PMID: 23681187
COX2; celecoxib; hTERT; telomerase
4.  Data Mining Nursing Care Plans of End of Life Patients: A Study to Improve Healthcare Decision Making 
Pain management of end of life patients (EOL) (n=596 episodes) is examined using statistical and data mining processes of the HANDS database of care plans coded with NANDA-I, NOC, and NIC (NNN) terminologies. HANDS episode data (episode =care plans updated at every handoff on a patient while staying on a hospital unit) were gathered in 8 units located in 4 different health care facilities (total episodes = 40,747; EOL episodes = 1,425) over two years. Results show the multiple discoveries such as EOL patients with hospital stays (< 72 hrs.) are less likely (p<0.005) to meet the pain relief goals compared to EOL patients with longer hospital stays. The study demonstrates a major benefit of systematically integrating NNN into electronic health records.
PMCID: PMC3641782  PMID: 23413930
Data mining; plan of care; electronic health record; end of life hospital care; pain
5.  Targeted therapy via oral administration of attenuated Salmonella expression plasmid-vectored Stat3-shRNA cures orthotopically transplanted mouse HCC 
Cancer gene therapy  2012;19(6):393-401.
The development of RNA interference-based cancer gene therapies has been delayed due to the lack of effective tumor-targeting delivery systems. Attenuated Salmonella enterica serovar Typhimurium (S. Typhimurium) has a natural tropism for solid tumors. We report here the use of attenuated S. Typhimurium as a vector to deliver shRNA directly into tumor cells. Constitutively activated signal transducer and activator of transcription 3 (Stat3) is a key transcription factor involved in both hepatocellular carcinoma (HCC) growth and metastasis. In this study, attenuated S. Typhimurium was capable of delivering shRNA-expressing vectors to the targeted cancer cells and inducing RNA interference in vivo. More importantly, a single oral dose of attenuated S. Typhimurium carrying shRNA-expressing vectors targeting Stat3 induced remarkably delayed and reduced HCC (in 70% of mice). Cancer in these cured mice did not recur over 2 years following treatment. These data demonstrated that RNA interference combined with Salmonella as a delivery system may offer a novel clinical approach for cancer gene therapy.
PMCID: PMC3891655  PMID: 22555509
HCC; immune response; RNA interference; Stat3
6.  Understanding strong magnetostriction in Fe100−xGax alloys 
Scientific Reports  2013;3:3521.
Magnetostriction of ferromagnetic materials describes the change of their shape or dimension in response to the reorientation of magnetization under the influence of external magnetic field. Fe100−xGax binary alloys (Galfenol) have large magnetostriction and excellent ductility; and they are very promising rare-earth free materials for applications in sensors, actuators, energy-harvesters and spintronic devices. Here we report results of large-scale ab initio molecular dynamics (AIMD) simulations for Galfenol, especially regarding the mechanism that leads to the sudden drop of tetragonal magnetostriction at x ~ 19, a long-standing puzzle for the community. Based on rigid band analysis, we propose possible ways to further optimize the performance of Galfenol for device applications. For example, we found that the substitution of a small amount of Cu for Ga (1.6%) in certain configuration may double the magnetostriction of Galfenol.
PMCID: PMC3865486  PMID: 24343479
7.  Recoil effects of a motional scatterer on single-photon scattering in one dimension 
Scientific Reports  2013;3:3144.
The scattering of a single photon with sufficiently high energy can cause a recoil of a motional scatterer. We study its backaction on the photon's coherent transport in one dimension by modeling the motional scatterer as a two-level system, which is trapped in a harmonic potential. While the reflection spectrum is of a single peak in the Lamb-Dicke limit, multi-peaks due to phonon excitations can be observed in the reflection spectrum as the trap becomes looser or the mass of the two-level system becomes smaller.
PMCID: PMC3826102  PMID: 24220217
8.  Activation of TLR4 signaling promotes gastric cancer progression by inducing mitochondrial ROS production 
Yuan, X | Zhou, Y | Wang, W | Li, J | Xie, G | Zhao, Y | Xu, D | Shen, L
Cell Death & Disease  2013;4(9):e794-.
Chronic infection, such as Helicobacter pylori infection, has been associated with the development of gastric cancer (GC). Pathogen-associated molecular patterns can trigger inflammatory responses via Toll-like receptors (TLRs) in GC. Here we showed that Toll-like receptor 4 (TLR4) was highly expressed in GC cells and was associated with the aggressiveness of GC. The binding of lipopolysaccharide (LPS) to TLR4 on GC cells enhanced proliferation without affecting apoptosis. Higher level of reactive oxygen species (ROS) was induced after activation of TLR4 signaling in GC. Using oxidase inhibitors and antioxidants, we found that mitochondrial ROS (mROS) was major source of TLR4-stimulated ROS generation. This elevated mROS production can be inhibited by diphenylene iodonium (DPI), and the blocking of the mROS production rather than ROS neutralization resulted in cell cycle arrest and the loss of mitochondrial potential, which were plausible reason for decreased cell viability. Furthermore, the increased mROS owing to TLR4 signaling resulted in the activation of Akt phosphorylation and NF-κB p65 nuclear translocation. Altogether, these results reveal a novel pathway linking innate immune signaling to GC cell proliferation, implicate mROS as an important component of cell survival signals and further establish mitochondria as hubs for GC therapies.
PMCID: PMC3789192  PMID: 24030146
TLR4; gastric cancer; mitochondrial ROS; progression
9.  Long-term lithium treatment in bipolar disorder is associated with longer leukocyte telomeres 
Translational Psychiatry  2013;3(5):e261-.
Telomere shortening is a hallmark of aging and has been associated with oxidative stress, inflammation and chronic somatic, as well as psychiatric disorders, including schizophrenia and depression. Additionally, antidepressants have been found to protect against telomere shortening. However, pharmacological telomere studies are lacking in bipolar disorder (BD). Therefore, the objective of this study was to explore telomere length (TL) in patients with BD in the context of lithium treatment. We determined TL by quantitative real-time PCR using peripheral blood leukocytes. Participants were outpatients diagnosed with BD type 1 or 2 (n=256) and healthy controls (n=139). Retrospective case–control and case–case study designs were applied. Lithium response (LiR) was scored using the Alda-Scale. Lithium-treated BD patients overall, as well as those on lithium monotherapy, had 35% longer telomeres compared with controls (P<0.0005, partial η2=0.13). TL correlated positively with lithium treatment duration of >30 months (P=0.031, R2=0.13) and was negatively associated with increasing number of depressive episodes (P<0.007). BD patients responding well to lithium treatment had longer telomeres than those not responding well. This is the first study to report a positive effect of long-term lithium treatment on TL. Importantly, longer TL was also associated with a better LiR in BD patients. These data suggest that lithium exerts a protective effect against telomere shortening especially when therapeutically efficacious. We hypothesize that induction of telomerase activity may be involved in LiR in BD.
PMCID: PMC3669924  PMID: 23695236
Alda-Scale; biomarker; lithium response; number of episodes; rapid cycling; telomerase
10.  Therapeutic Hypothermia for Neonatal Encephalopathy Results in Improved Microstructure and Metabolism in the Deep Gray Nuclei 
Therapeutic hypothermia has reduced morbidity and mortality and is associated with a lower burden of lesions on conventional imaging in NE. However, its effects on brain microstructure and metabolism have not been fully characterized. We hypothesized that therapeutic hypothermia improves measures of brain microstructure and metabolism.
Forty-one neonates with moderate/severe NE (29 treated with hypothermia, 12 nontreated) and 12 healthy neonates underwent MR imaging, DTI, and 1H-MR spectroscopy. MR imaging scans were scored by the predominant pattern of brain injury: normal, watershed, and BG/thalamus. ADC, FA, Lac:NAA, and NAA:Cho values from bilateral BG and thalamus ROIs were averaged. T test and linear regression analysis were used to determine the association between hypothermia and MR imaging quantitative measures.
Conventional MR imaging findings were normal in 41% of treated neonates; all nontreated neonates had brain injury. Values of MR imaging metrics were closer to normal in treated neonates compared with nontreated neonates: ADC was 63% higher in the BG and 116% higher in the thalamus (both P < .05), and Lac:NAA was 76% lower (P = .04) in the BG. Treated neonates with normal MR imaging findings had normal 1H-MR spectroscopy metabolites, and ADC was higher by 35% in the thalamus (P = .03) compared with healthy neonates.
Therapeutic hypothermia may reduce disturbances of brain metabolism and preserve its microstructure in the setting of NE, possibly by minimizing cytotoxic edema and cell death. Long-term follow-up studies are required to determine whether early post-treatment DTI and 1H-MR spectroscopy will be useful biomarkers of treatment response.
PMCID: PMC3473161  PMID: 22595900
11.  Mechanical and Biochemical Characterization of Cartilage Explants in Serum-Free Culture 
Journal of Biomechanics  2008;41(6):1153-1159.
Allografts of articular cartilage are both used clinically for tissue-transplantation procedures and experimentally as model systems to study the physiological behavior of chondrocytes in their native extracellular matrix. Long-term maintenance of allograft tissue is challenging. Chemical mediators in poorly defined culture media can stimulate cells to quickly degrade their surrounding extracellular matrix. This is particularly true of juvenile cartilage which is generally more responsive to chemical stimuli than mature tissue. By carefully modulating the culture media however it may be possible to preserve allograft tissue over the long-term while maintaining its original mechanical and biochemical properties. In this study juvenile bovine cartilage explants (both chondral and osteochondral) were cultured in both chemically defined medium and serum-supplemented medium for up to 6 weeks. The mechanical properties and biochemical content of explants cultured in chemically-defined medium were enhanced after 2 weeks in culture and thereafter remained stable with no loss of cell viability. In contrast, the mechanical properties of explants in serum-supplemented medium were degraded by (~70%) along with a concurrent loss of biochemical content (30~40% GAG). These results suggest that long-term maintenance of allografts can be extended significantly by the use of a chemically-defined medium.
PMCID: PMC3387278  PMID: 18374344
12.  Monitoring non-invasive cardiac output and stroke volume during experimental human hypovolaemia and resuscitation 
Multiple methods for non-invasive measurement of cardiac output (CO) and stroke volume (SV) exist. Their comparative capabilities are not clearly established.
Healthy human subjects (n=21) underwent central hypovolaemia through progressive lower body negative pressure (LBNP) until the onset of presyncope, followed by termination of LBNP, to simulate complete resuscitation. Measurement methods were electrical bioimpedance (EBI) of the thorax and three measurements of CO and SV derived from the arterial blood pressure (ABP) waveform: the Modelflow (MF) method, the long-time interval (LTI) method, and pulse pressure (PP). We computed areas under receiver-operating characteristic curves (ROC AUCs) for the investigational metrics, to determine how well they discriminated between every combination of LBNP levels.
LTI and EBI yielded similar reductions in SV during progressive hypovolaemia and resuscitation (correlation coefficient 0.83) with ROC AUCs for distinguishing major LBNP (−60 mm Hg) vs resuscitation (0 mm Hg) of 0.98 and 0.99, respectively. MF yielded very similar reductions and ROC AUCs during progressive hypovolaemia, but after resuscitation, MF-CO did not return to baseline, yielding lower ROC AUCs (ΔROC AUC range, −0.18 to −0.26, P<0.01). PP declined during hypovolaemia but tended to be an inferior indicator of specific LBNP levels, and PP did not recover during resuscitation, yielding lower ROC curves (P<0.01).
LTI, EBI, and MF were able to track progressive hypovolaemia. PP decreased during hypovolaemia but its magnitude of reduction underestimated reductions in SV. PP and MF were inferior for the identification of resuscitation.
PMCID: PMC3000628  PMID: 21051492
arterial pressure, measurement; blood, loss; cardiovascular system, responses; equipment, finapres; monitoring, cardiopulmonary
13.  Hippocampal CA1 apical neuropil atrophy in mild Alzheimer disease visualized with 7-T MRI(Podcast) 
Neurology  2010;75(15):1381-1387.
In Alzheimer disease (AD), mounting evidence points to a greater role for synaptic loss than neuronal loss. Supporting this notion, multiple postmortem studies have demonstrated that the hippocampal CA1 apical neuropil is one of the earliest sites of pathology, exhibiting tau aggregates and then atrophy before there is substantial loss of the CA1 pyramidal neurons themselves. In this cross-sectional study, we tested whether tissue loss in the CA1 apical neuropil layer can be observed in vivo in patients with mild AD.
We performed ultra-high-field 7-T MRI on subjects with mild AD (n = 14) and age-matched normal controls (n = 16). With a 2-dimensional T2*-weighted gradient-recalled echo sequence that was easily tolerated by subjects, we obtained cross-sectional slices of the hippocampus at an in-plane resolution of 195 μm.
On images revealing the anatomic landmarks of hippocampal subfields and strata, we observed thinning of the CA1 apical neuropil in subjects with mild AD compared to controls. By contrast, the 2 groups exhibited no difference in the thickness of the CA1 cell body layer or of the entire CA1 subfield. Hippocampal volume, measured on a conventional T1-weighted sequence obtained at 3T, also did not differentiate these patients with mild AD from controls.
CA1 apical neuropil atrophy is apparent in patients with mild AD. With its superior spatial resolution, 7-T MRI permits in vivo analysis of a very focal, early site of AD pathology.
= Alzheimer disease;
= Clinical Dementia Rating;
= dentate gyrus;
= gradient-recalled echo;
= normal control;
= Pittsburgh Compound B;
= stratum pyramidale;
= stratum radiatum and stratum lacunosum-moleculare;
= total intracranial volume.
PMCID: PMC3013485  PMID: 20938031
14.  P53 in human melanoma fails to regulate target genes associated with apoptosis and the cell cycle and may contribute to proliferation 
BMC Cancer  2011;11:203.
Metastatic melanoma represents a major clinical problem. Its incidence continues to rise in western countries and there are currently no curative treatments. While mutation of the P53 tumour suppressor gene is a common feature of many types of cancer, mutational inactivation of P53 in melanoma is uncommon; however, its function often appears abnormal.
In this study whole genome bead arrays were used to examine the transcript expression of P53 target genes in extracts from 82 melanoma metastases and 6 melanoma cell lines, to provide a global assessment of aberrant P53 function. The expression of these genes was also examined in extracts derived from diploid human melanocytes and fibroblasts.
The results indicated that P53 target transcripts involved in apoptosis were under-expressed in melanoma metastases and melanoma cell lines, while those involved in the cell cycle were over-expressed in melanoma cell lines. There was little difference in the transcript expression of P53 target genes between cell lines with null/mutant P53 compared to those with wild-type P53, suggesting that altered expression in melanoma was not related to P53 status. Similarly, down-regulation of P53 by short-hairpin RNA (shRNA) had limited effect on P53 target gene expression in melanoma cells, whereas there were a large number of P53 target genes whose mRNA expression was significantly altered by P53 inhibition in melanocytes. Analysis of whole genome gene expression profiles indicated that the ability of P53 to regulate genes involved in the cell cycle was significantly reduced in melanoma cells. Moreover, inhibition of P53 in melanocytes induced changes in gene expression profiles that were characteristic of melanoma cells and resulted in increased proliferation. Conversely, knockdown of P53 in melanoma cells resulted in decreased proliferation.
These results indicate that P53 target genes involved in apoptosis and cell cycle regulation are aberrantly expressed in melanoma and that this aberrant functional activity of P53 may contribute to the proliferation of melanoma.
PMCID: PMC3120805  PMID: 21615965
15.  Chinese Ischemic Stroke Subclassification 
Accurate classification of stroke has significant impact on patient care and conduction of stroke clinical trials. The current systems such as TOAST, SSS-TOAST, Korean TOAST, and A–S–C–O have limitations. With the advent of new imaging technology, there is a need to have a more accurate stroke subclassification system. Chinese ischemic stroke subclassification (CISS) system is a new two step system aims at the etiology and then underlying mechanism of a stroke. The first step classify stroke into five categories: large artery atherosclerosis (LAA), including atherosclerosis of aortic arch and intra-/extracranial large arteries, cardiogenic stroke, penetrating artery disease, other etiology, and undetermined etiology. The second step is to further classify the underlying mechanism of ischemic stroke from the intracranial and extracranial LAA into the parent artery (plaque or thrombosis) occluding penetrating artery, artery-to-artery embolism, hypoperfusion/impaired emboli clearance, and multiple mechanisms. Although clinical validation of CISS is being planned, CISS is an innovative system that offers much more detailed information on the pathophysiology of a stroke.
PMCID: PMC3052771  PMID: 21427797
ischemic stroke; subclassification; etiology; mechanism; Chinese
16.  Global In-silico identification of General and Kinase-Specific Phosphorylation Sites 
Journal of Biomolecular Techniques : JBT  2010;21(3 Suppl):S21-S22.
Reversible protein phosphorylation is one of the most pervasive posttranslational modifications, regulating diverse cellular processes in various organisms. High-throughput experimental studies using mass spectrometry have identified thousands of phosphorylation sites, primarily from eukaryotes. However, the vast majority of phosphorylation sites remain undiscovered, even in well-studied systems. Since mass spectrometry-based experimental approaches for identifying phosphorylation events are costly, time consuming, and are biased towards abundant proteins and proteotypic peptides, in silico prediction of phosphorylation sites is an attractive alternative for whole proteome annotation. Due to various limitations, current phosphorylation-site prediction tools were not well-designed for comprehensive assessment of proteomes. Here, we present a novel software tool, MUSite, specifically designed for large-scale prediction of both general and kinase-specific phosphorylation sites. We collected high confidence phosphoproteomics data from multiple organisms and used these to train prediction models by a comprehensive machine learning approach. Application of MUSite on proteomes of Homo sapiens, Mus musculus, Drosophila melanogaster, Caenorhabditis elegans, Saccharomyces cerevisiae, and Arabidopsis thaliana yielded tens of thousands of phosphorylation-site predictions with high stringency. Cross-validation tests show that MUSite significantly outperforms existing tools for predicting general phosphorylation sites and is at least comparable to those for predicting kinase-specific phosphorylation sites. Furthermore, MUSite provides several other unique functionalities such as customized model training and continuous stringency selection by users. With the user-friendly graphical user interface, MUSite provides a useful bioinformatics tool to biologists for predicting phosphorylation sites en masse and training prediction models from custom phosphorylation data. In addition, with its easily-extensible open-source application programming interface (API), MUSite is aimed at being an open platform for community-based development of machine-learning based phosphorylation-site prediction applications. MUSite is available at
PMCID: PMC2918177
17.  IL-33 protects mice from sepsis by inhibiting TLR4 signaling 
Critical Care  2009;13(Suppl 4):P43.
PMCID: PMC2776216
18.  Effects of long term Tai Chi practice and jogging exercise on muscle strength and endurance in older people 
To investigate the influence of regular Tai Chi (TC) practice and jogging on muscle strength and endurance in the lower extremities of older people.
Twenty one long term older TC practitioners were compared with 18 regular older joggers and 22 sedentary counterparts. Maximum concentric strength of knee flexors and extensors was tested at angular velocities of 30°/s and 120°/s. Ankle dorsiflexors and plantar flexors were tested at 30°/s and the dynamic endurance of the knee flexors and extensors was assessed at a speed of 180°/s.
The differences in the muscle strength of the knee joint amongst the three experimental groups were significant at the higher velocity. The strengths of knee extensors and flexors in the control group were significantly lower than those in the jogging group and marginally lower than those in the TC group. For the ankle joint, the subjects in both the TC and jogging groups generated more torque in their ankle dorsiflexors. In addition, the muscle endurance of knee extensors was more pronounced in TC practitioners than in controls.
Regular older TC practitioners and joggers showed better scores than the sedentary controls on most muscle strength and endurance measures. However, the magnitude of the exercise effects on muscles might depend on the characteristics of different types of exercise.
PMCID: PMC2491912  PMID: 16371491
jogging; muscle strength; older people; Tai Chi
19.  Toll-like receptor 2 signalling and inflammation 
Annals of the Rheumatic Diseases  2005;64(Suppl 4):iv104-iv105.
PMCID: PMC1766907  PMID: 16239376
20.  The effector caspases drICE and dcp-1 have partially overlapping functions in the apoptotic pathway in Drosophila 
Cell death and differentiation  2006;13(10):1697-1706.
Caspases are essential components of the apoptotic machinery in both vertebrates and invertebrates. Here, we report the isolation of a mutant allele of the Drosophila effector caspase drICE as a strong suppressor of hid- (head involution defective-) induced apoptosis. This mutant was used to determine the apoptotic role of drICE. Our data are consistent with an important function of drICE for developmental and irradiation-induced cell death. Epistatic analysis suggests that drICE acts genetically downstream of Drosophila inhibitor of apoptosis protein 1 (Diap1). However, although cell death is significantly reduced in drICE mutants in all assays, it is not completely blocked. A double-mutant analysis between drICE and death caspase-1 (dcp-1), another effector caspase, reveals that some cells (type I) strictly require drICE for apoptosis, whereas other cells (type II) require either drICE or dcp-1. Thus, these data demonstrate a barely appreciated complexity in the apoptotic pathway, and are consistent with current models about effector caspase regulation in both vertebrates and invertebrates.
PMCID: PMC2519037  PMID: 16645642
DrICE; Dcp-1; Drosophila; programmed cell death; Diap1; Dronc
21.  ARK, the Apaf-1 related killer in Drosophila, requires diverse domains for its apoptotic activity 
Cell death and differentiation  2006;14(1):92-102.
In mammals and Drosophila, apoptotic caspases are under positive control of the CED-4-like proteins Apaf-1 and ARK, respectively. In an EMS-mutagenesis screen, we isolated 33 ark mutants as recessive suppressors of hid-induced apoptosis. The ark mutants are loss-of-function alleles characterized by reduced developmental apoptosis. Using the phenotypic series of these alleles, we identified helical domain I in the nucleotide oligomerization domain as critical for ARK's apoptotic activity. Interestingly, the WD40 region may also have an unanticipated positive requirement for the apoptotic activity of ARK. Considering structural information, we discuss the roles of these domains for assembly and activity of the ARK apoptosome, and propose that the WD40 region is anti-apoptotic in the absence of apoptotic signals, and pro-apoptotic in the presence of such signals. Furthermore, a defined null allele reveals that ark is required for most, but not all apoptosis suggesting the existence of an ARK-independent apoptotic pathway.
PMCID: PMC2502064  PMID: 16645639
ARK; Drosophila; WD40; apoptosis; Apaf-1
22.  A toll for T cell costimulation 
Annals of the Rheumatic Diseases  2004;63(Suppl 2):ii76-ii78.
PMCID: PMC1766781  PMID: 15479878
23.  Nucleostemin mRNA is expressed in both normal and malignant renal tissues 
Fan, Y | Liu, Z | Zhao, S | Lou, F | Nilsson, S | Ekman, P | Xu, D | Fang, X
British Journal of Cancer  2006;94(11):1658-1662.
Nucleostemin (NS), a p53-binding protein, has been shown essential for stem and cancer cell proliferation and implicated in oncogenesis. To explore potential contributions of NS to the development of clear cell renal cell carcinomas (ccRCCs), we determined NS expression in ccRCC cell lines, and in paired normal and malignant renal tissues from 31 patients with ccRCC. Nucleostemin mRNA and/or protein expression was observed in all four cell lines and 27 of 31 (87%) tumour specimens. Surprisingly, 16 of 31 (52%) adjacent normal renal samples also expressed NS mRNA and its levels in four of them were comparable with those in paired tumour tissues. Three of the patients had detectable NS mRNA in their normal renal tissues whereas lacked its expression in the matched tumours. Compared to the oncogene c-MYC expression in these same samples, NS expression showed a much less specificity for ccRCC. We further demonstrated that NS mRNA expression was closely associated with cellular proliferation in normal fibroblasts or T lymphocytes and renal cell carcinoma cell lines. Collectively, NS expression widely occurs in normal and malignant renal tissues, and is likely a proliferation marker rather than a unique regulator of cell proliferation and survival in stem and cancer cells.
PMCID: PMC2361296  PMID: 16670719
nucleostemin; RCC; renal tissues; c-MYC
24.  Effect of tai chi exercise on proprioception of ankle and knee joints in old people 
Xu, D | Hong, Y | Li, J | Chan, K
Objectives: To assess if tai chi, a traditional Chinese form of exercise, could improve proprioception in old people and if the effects of tai chi on proprioception are more evident than other exercise forms in the elderly.
Methods: By detecting the threshold of passive movement, ankle and knee joint kinaesthesis was measured in 21 elderly long term tai chi practitioners (TC group), 20 elderly long term swimmers/runners (S/R group), and 27 elderly sedentary controls (control group).
Results: Ankle joint kinaesthesis differed significantly among the three groups (p = 0.001). Subjects in the TC group could detect a significantly smaller amount of motion than those in the S/R group (p = 0.022) and control group (p = 0.001). No significant difference was found between the S/R group and the control group (p = 0.701). The threshold for detection of passive motion was significantly different in knee extension and flexion. For knee flexion, the TC group showed a significantly lower mean threshold for detection of passive motion than the control group (p = 0.026). There were no significant differences between the S/R group and control group (p = 0.312), or between the TC group and S/R group (p = 0.533). For knee extension, no significant difference was noted among the three groups (p = 0.597).
Conclusions: The elderly people who regularly practiced tai chi not only showed better proprioception at the ankle and knee joints than sedentary controls, but also better ankle kinaesthesis than swimmers/runners. The large benefits of tai chi exercise on proprioception may result in the maintenance of balance control in older people.
PMCID: PMC1724726  PMID: 14751946
25.  Aplastic anaemia associated with parvovirus B19 infection 
Qian, X | Zhang, G | Jiao, X | Zheng, Y | Cao, Y | Xu, D | Chen, C
Archives of Disease in Childhood  2002;87(5):436-437.
PMCID: PMC1763065  PMID: 12390927

Results 1-25 (43)