Expression and clinical significance of SHP2 in gastric cancer

OBJECTIVES

To investigate the expression and clinical significance of the protein tyrosine phosphatase, nonreceptor type 11 (PTPN11 or SHP2) gene, which encodes Src homology 2 domain-containing phosphatase (SHP-2) in gastric cancer.

METHODS

SHP2 expression was detected by immunohistochemical staining and real-time quantitative reverse transcription-polymerase chain reaction in tissue samples of normal gastric mucosa and different grades of gastric cancer. Correlation between SHP2 expression and standard clinico pathological parameters was analysed.

RESULTS

Immunohistochemical staining revealed significantly higher rates of SHP2 expression in gastric cancer tissues (72.5%) versus normal gastric mucosa (21.9%). SHP-2 mRNA levels were also significantly higher in gastric cancer tissues versus normal gastric mucosa. SHP2 expression correlated significantly with tumour differentiation, clinical classification and lymph node metastases, but was independent of sex and age.

CONCLUSIONS

SHP-2 is upregulated in gastric cancer and may be related to the development of gastric cancer. SHP-2 may be a potential prognostic marker of, or a therapeutic target for, gastric cancer.

Unilateral deep brain stimulation of the right globus pallidus internus in patients with Tourette's syndrome: two cases with outcomes after 1 year and a brief review of the literature

Tourette's syndrome is a complex neuropsychiatric disorder, characterized by tics. Bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) has been considered to be an effective treatment for refractory Tourette's syndrome. Postoperative outcomes are described after 12 months' follow-up in a 41-year-old male patient and a 22-year-old male patient with Tourette's syndrome, both of whom underwent unilateral electrode implantations into the right GPi for DBS. These patients were diagnosed with Tourette's syndrome in childhood and, despite long-term therapy with a range of antipsychotic medications, continued to experience disabling tics in adulthood. Improvements in tic severity of 58.5% and 53.1% were observed at 12 months in the older and younger patient, respectively; improvements were determined by the Yale Global Tic Severity Scale. Both patients also experienced reductions in tic frequency and reported improvements in their health-related quality of life. Improvements in tics were similar to previous reports involving patients who underwent bilateral GPi DBS. These cases suggest that unilateral DBS of the right GPi is effective and might be a viable surgical choice for some patients with Tourette's syndrome.

Obstetric outcome of ethnic Turkish women in London: a retrospective case-control study

There is concern that the maternal mortality in ethnic minority women is significantly greater than that of Caucasian British women. The objective of this study was to compare the demographic and obstetric outcomes between these two groups. Data were collected retrospectively over a 2-year period from 148 index and 148 control cases. The study group had statistically similar maternal age, labour duration, blood loss and mode of delivery compared with Caucasian British women (p > 0.05). A total of 68% of Turkish women spoke little or no English; were more likely to be non-smokers and also more likely to be married to unemployed spouses (p = 0.0001). This is the first study comparing obstetric outcomes of immigrant Turkish women with their Caucasian British counterparts. There was no significant difference in maternal or fetal outcomes, which could be attributed to the 'healthy migrant' theory, coupled with increased vigilance in ethnic minority pregnancies.

Effector biology of plant-associated organisms: concepts and perspectives

Every plant is closely associated with a variety of living organisms. Therefore, deciphering how plants interact with mutualistic and parasitic organisms is essential for a comprehensive understanding of the biology of plants. The field of plant-biotic interactions has recently coalesced around an integrated model. Major classes of molecular players both from plants and their associated organisms have been revealed. These include cell surface and intracellular immune receptors of plants as well as apoplastic and host-cell-translocated (cytoplasmic) effectors of the invading organism. This article focuses on effectors, molecules secreted by plant-associated organisms that alter plant processes. Effectors have emerged as a central class of molecules in our integrated view of plant-microbe interactions. Their study has significantly contributed to advancing our knowledge of plant hormones, plant development, plant receptors, and epigenetics. Many pathogen effectors are extraordinary examples of biological innovation; they include some of the most remarkable proteins known to function inside plant cells. Here, we review some of the key concepts that have emerged from the study of the effectors of plant-associated organisms. In particular, we focus on how effectors function in plant tissues and discuss future perspectives in the field of effector biology.

Regulation of ATG6/Beclin-1 homologs by abiotic stresses and hormones in rice (Oryza sativa L.)

Autophagy, a complex and conserved mechanism, serving as a defense response in all eukaryotic organisms, is regulated by several proteins, among which ATG proteins are the most important due to their involvement in autophagosome formation. ATG6/Beclin-1 proteins, reported to be essential for autophagosome formation and assigned as a conserved domain, were subjected to database searches. We found three homologs in the rice (Oryza sativa) genome. A phylogeny tree was constructed to establish their across species relationship, which divided them into three distinct groups; two for plants, i.e., monocots and dicots, and one for animals. Evolutionary study of this family by critical amino acid conservation analysis revealed significant functional divergence. The finding of important stress-related cis-acting elements in the promoter region of rice ATG6 genes demonstrated their involvement in abiotic stress responses. Furthermore, expression profiling of rice ATG6 genes based on microarray data, as well as by semi-quantitative RT-PCR showed differential expression when subjected to different stresses suggesting the involvement of OsATG6 genes in abiotic stresses (heat, cold and drought) and hormone (abscisic acid) responses. Analysis of co-expressed genes showed that most of them annotated to DNA repair pathways and proteolysis, etc. Collectively, these results suggest the involvement of OsATG6 genes in different stresses, and provide a basis for further functional studies to investigate the biological mechanism of action of these genes under abiotic stresses.

Detection of hydrazine, methylhydrazine, and isoniazid by capillary electrophoresis with a palladium-modified microdisk array electrode

A palladium particle-modified carbon fiber microdisk array electrode was designed and employed in capillary electrophoresis for the simultaneous detection of hydrazine, methylhydrazine, and isoniazid. The Pd-modified microdisk electrode had high catalytic ability for hydrazines and exhibited good reproducibility and stability. The response for hydrazine was linear over 3 orders of magnitude with a correlation coefficient of 0.993. The detection limits for hydrazine, methylhydrazine, and isoniazid were 1.2, 2.1, and 6.2 pg, respectively.

Clinical controlled comparison between lobectomy and segmental resection for patients over 70 years of age with clinical stage I non-small cell lung cancer

AIMS

The standard surgical procedure for elderly (≥ 70 years) patients with clinical stage I non-small cell lung cancer (NSCLC) was investigated.

METHODS

A non-randomized prospective controlled study was conducted to compare lobectomy with segmental resection for the treatment of elderly clinical stage I lung cancer patients under different pulmonary function. Perioperative indicators including time and volume of thoracic drainage, incidence of postoperative complications, locoregional recurrence rates, and 1, 3, and 5-year survival rates were analyzed.

RESULTS

A total of 184 patients were included in the study. Patients were classified into two groups according to pulmonary function: group 1 included 64 patients who had poor pulmonary function, with a forced expiratory volume in 1 s (FEV(1)) of less than 1.5 L, whereas group 2 consisted of 120 patients with an FEV(1) ≥ 1.5 L. The patients in group 1 had a longer postoperative mechanical ventilation time and a higher incidence rate of respiratory associated complications than those in group 2 (21.9 vs. 8.35%, p = 0.009). The local recurrence and long-term survival rates were not significantly different between lobectomy and segmental resection. Among the patients who underwent segmental resection, those who had regional lymph node dissection showed a higher 3-year and 5-year survival rate than those undergoing selected lymph node resection (77.8 vs. 51.7%, p = 0.042; 55.6 vs. 27.6%, p = 0.034), but this was not significant in lobectomy.

CONCLUSIONS

Segmental resection combined with regional lymph node resection could be the best choice for elderly clinical stage I NSCLC patients with FEV(1) < 1.5 L.

Changes in Spontaneous Dorsal Horn Potentials after Dorsal Root Entry Zone Lesioning in Patients with Pain after Brachial Plexus Avulsion

OBJECTIVES: This study investigated spontaneous dorsal horn potentials in patients with pain after brachial plexus avulsion and determined the effect of dorsal root entry zone (DREZ) lesioning on these potentials and on pain levels. METHODS: Electrospinography (ESG) recordings were undertaken in seven patients using a noninvasive electrocorticography strip electrode. Measurements were taken from the DREZ on the intact side of the spinal cord before lesioning of the injured DREZ and from the injured DREZ before and after lesioning. RESULTS: DREZ lesioning had a significant positive effect on pain at 12 months postoperatively. At 15.0 Hz, the mean ESG power from the injured DREZ before lesioning was significantly higher than that from the intact DREZ. In addition, the mean ESG power from the injured DREZ after successful DREZ lesioning was significantly lower than that from the intact DREZ and that from the injured DREZ before lesioning. CONCLUSIONS: The ESG power from the injured DREZ increases in patients with pain after brachial plexus avulsion compared with that of the intact DREZ; this increase is reduced by successful DREZ lesioning.

MTSS1, a novel target of DNA methyltransferase 3B, functions as a tumor suppressor in hepatocellular carcinoma

DNA methyltransferase 3B (DNMT3B) mediates gene silencing via epigenetic mechanisms during hepatocellular carcinoma (HCC) progression. We aimed to identify novel targets of DNMT3B and their potential regulatory mechanisms in HCC. Metastasis suppressor 1 (MTSS1) was one of the DNMT3B targets and selected for further study. DNMT3B overexpression was detected in 81.25% of clinical HCC specimens and was negatively associated with MTSS1 in HCC cells and clinical samples. The underlying mechanism by which DNMT3B silences MTSS1 was studied using a combination of methylation-specific polymerase chain reaction (PCR) and bisulfite genome sequencing, chromatin immunoprecipitation-PCR and luciferase reporter assays. We found that the MTSS1 promoter region was sparsely methylated, and the methylation inhibitors failed to abolish DNMT3B-mediated MTSS1 silencing. DNMT3B protein bound directly to the 5'-flanking region (-865/-645) of the MTSS1 gene to inhibit its transcription. The functional role of MTSS1 was investigated using in vitro and in vivo tumorigenicity assays. As a result, MTSS1 exerted tumor suppressor effects and arrested cells in the G2/M phase, but not the G1/S phase of the cell cycle when it was depleted or overexpressed in HCC cells. Taken together, MTSS1, a novel target of DNMT3B, is repressed by DNMT3B via a DNA methylation-independent mechanism. MTSS1 was further characterized as a novel tumor suppressor gene in HCC. These findings highlight how DNMT3B regulates MTSS1, and such data may be useful for the development of new treatment options for HCC.

Sulphoraphane inhibited the expressions of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 through MyD88-dependent toll-like receptor-4 pathway in cultured endothelial cells

BACKGROUND AND AIMS

Chronic inflammation plays pivotal roles in both cancer and cardiovascular diseases. A large body of evidence suggests that high intake of cruciferous vegetables is closely related with low risk of these disorders. However, the underlying mechanisms of protection are not fully understood. The aim of this study is to test the protective effects of an isothiocyanate sulphoraphane on inflammatory injury and related regulation pathways in cultured endothelial cells.

METHODS AND RESULTS

The expressions of adhesion molecules were determined by TaqMan real-time polymerase chain reaction (PCR) and Western blot analysis. Nuclear factor-kappa B (NF-кB) translocation was detected by immunofluorescent hybridisation. Other proteins were measured by Western blot analysis. The results demonstrated that sulphoraphane significantly suppresses the expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 stimulated by lipopolysaccharide (LPS) both at the transcriptional and translational levels. In addition, sulphoraphane inhibited the translocation of NF-кB into the nucleus. Sulphoraphane decreased the phosphorylation of extra-cellular signal-regulated kinase (ERK), Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), while further blockade and activation using individually specific agents confirm that p38 MAPK and JNK are mainly involved. Interestingly, sulphoraphane down-regulated Toll-like receptor (TLR)-4, a receptor of LPS located on the membrane. In addition, MyD88, an effector downstream TLR-4 signal pathway was subsequently attenuated.

CONCLUSION

Taken all together, adhesion molecules are confirmed to be the novel targets of sulphoraphane in preventing inflammatory insult to endothelial cells. Sulphoraphane suppressed TLR-4 followed by MyD88 and downstream factors such as p38 MAPK and JNK, ultimately blocking NF-кB translocation and the subsequent expression of adhesion molecules. These data suggested a novel inflammatory pathway mediated by sulphoraphane.

Microarray analysis of gene expression changes in the brains of NR2B-induced memory-enhanced mice

Glutamate N-methyl-D-aspartate (NMDA) receptors play a pivotal role in different forms of memory. The dysfunction of NMDA receptors contributes to the pathology of central nervous system (CNS) disorders. To further investigate the role of the NMDA receptors in brain processes, we analyzed and compared the gene expression profiles in the hippocampus of NR2B overexpression-induced memory-enhanced mice (Tg mice) with those of their wild-type littermates. Results reveal that 249 genes, which are mainly involved in neurotransmission, signal transduction, cytoskeletal structure, hormone activity, and transcription, were significantly affected in Tg mice. Interestingly, the intracellular calcium channel proteins ryanodine receptor (RyR) 1 and 3, as well as functionally related proteins such as the histidine-rich calcium-binding protein and triadin 2, were upregulated. The Homer-1c protein was also increased in Tg mice and formed a complex with the RyR protein in the mouse brain, suggesting that Homer-1c is an important modulator in both intracellular calcium signaling and overall neuronal signaling by simultaneously interacting with the NMDA receptors and RyR. Western blot and real-time PCR results show that the expression of phospho-CREB, c-fos, and the immediate-early genes Egr2 and Egr4 were also upregulated in Tg mice. The current study demonstrates that a chronic increase in the activation of NMDA receptors affected the expression of a large number of genes and may provide important clues for a better understanding of the molecular mechanism of NMDA receptor-modulated learning and memory, as well as of CNS disorders.

Bisphenol A induces a rapid activation of Erk1/2 through GPR30 in human breast cancer cells

Bisphenol A (BPA) has been considered as an endocrine disruptor due to its ability to interact with estrogen receptors (ERs). While G protein-coupled receptor 30 (GPR30) is a novel estrogen receptor, its role in BPA-induced activation of Erk1/2 remains unknown. Human breast cancer cell lines, MCF-7, MDA-MB-231 and SKBR3, were used as experimental models to discriminate between ERs-dependent, putative ERs-independent and/or GPR30-associated effects. BPA induced a rapid activation of Erk1/2 in both ERα/β-positive and negative breast cancer cells, and this effect was not blocked with an ER antagonist, ICI 182,780. A small interfering RNA assay revealed that the expression of GPR30 was necessary for BPA-induced activation of Erk1/2 and transcriptional regulation of c-fos. In addition, BPA regulates the expression of c-fos likely through an AP1-mediated pathway. As a conclusion, GPR30 plays an important role in the BPA-induced activation of Erk1/2 in a manner distinguishable from that in ERα-mediated signaling.

Contribution of hydrodynamic characteristics on the performance of an aerobic biofilm conical fluidized bed

The performance of a conical fluidized bed (TFB) bioreactor, including the biofilm thickness, microbial space density, microbial cell matrix and its efficiency for COD degradation at a bed expansion ratio of 14 to 90%, was studied and compared with a cylindrical fluidized bed (CFB) bioreactor. The hydrodynamic characteristics of the TFB, especially the internal-circulation of bioparticles associated with its unique tapered geometry of the bed, created a much more uniform axial distribution of the bioparticles, leading to the formation of thinner and more compacted biofilms in the TFB compared to that in the CFB. The thinner biofilm in the TFB tended to be stable and possessed more than 6 times of microbial population density compared to the CFB. As a result, thinner biofilms in the TFB contributed to a higher COD removal efficiency, which remained at over 95% at operated expansion ratios, about 15 to 25% higher than that in the CFB.

The reduced and altered activities of PAX5 are linked to the protein-protein interaction motif (coiled-coil domain) of the PAX5-PML fusion protein in t(9;15)-associated acute lymphocytic leukemia

The paired box domain of PAX5 was reported to fuse with the sequence of promyelocytic leukemia (PML) to produce PAX5-PML chimeric protein in two patients with B-cell acute lymphoblastic leukemia. In the present studies, we found, by gel shift assays, that PAX5-PML bound to a panel of PAX5-consensus sequence acts as a homodimer with reduction of its DNA-binding affinities in comparison with wild-type PAX5. In transient transfection assays using 293T and HeLa cells, and retrovirus transduction of murine hematopoietic stem/progenitor cells together with quantitative real-time polymerase chain reaction analysis, PAX5-PML inhibited wild-type PAX5 target gene transcriptional activity. Studies comparing PAX5-PML with PAX5-PML(ΔCC) demonstrated that the coiled-coil (CC) protein interaction domain located within the PML moiety was required for PAX5-PML homodimer complex formation and partial transcriptional repression of genes controlled by PAX5. Fluorescent microscopic examination of transiently expressed YFP-tagged proteins in HeLa and 293T cells demonstrated that YFP-PAX5-PML and YFP-PAX5-PML(ΔCC) exhibited a diffuse granular pattern within the nucleus, similar to PAX5 but not PML. By fluorescent recovery after photobleach (FRAP), we have shown that PAX5-PML fusion protein has reduced intranuclear mobility compared with wild-type PAX5. Furthermore, the dimerization domain (CC) of PML was responsible for the reduced intranuclear mobility of PAX5-PML. These results indicate that the CC domain of PAX5-PML is important for each of the known activities of PAX5-PML fusion proteins.

The role of fibroblast Tiam1 in tumor cell invasion and metastasis

The co-evolution of tumors and their microenvironment involves bidirectional communication between tumor cells and tumor-associated stroma. Various cell types are present in tumor-associated stroma, of which fibroblasts are the most abundant. The Rac exchange factor Tiam1 is implicated in multiple signaling pathways in epithelial tumor cells and lack of Tiam1 in tumor cells retards tumor growth in Tiam1 knock-out mouse models. Conversely, tumors arising in Tiam1 knock-out mice have increased invasiveness. We have investigated the role of Tiam1 in tumor-associated fibroblasts as a modulator of tumor cell invasion and metastasis, using retroviral delivery of short hairpin RNA to suppress Tiam1 levels in three different experimental models. In spheroid co-culture of mammary epithelial cells and fibroblasts, Tiam1 silencing in fibroblasts led to increased epithelial cell outgrowth into matrix. In tissue-engineered human skin, Tiam1 silencing in dermal fibroblasts led to increased invasiveness of epidermal keratinocytes with premalignant features. In a model of human breast cancer in mice, co-implantation of mammary fibroblasts inhibited tumor invasion and metastasis, which was reversed by Tiam1 silencing in co-injected fibroblasts. These results suggest that stromal Tiam1 may play a role in modulating the effects of the tumor microenvironment on malignant cell invasion and metastasis. This suggests a set of pathways for further investigation, with implications for future therapeutic targets.

Tonotopic changes in GABA receptor expression in guinea pig inferior colliculus after partial unilateral hearing loss

Immunohistochemistry was used to investigate the topographic distribution of the alpha1 subunit of the GABA receptor (GABRA1) in guinea pig inferior colliculus after treatments that caused a unilateral loss of peripheral neural sensitivity in the high-frequency regions of the cochlea. Both forms of treatment (direct mechanical lesion of the cochlea and acoustic overstimulation) resulted in a significant decrease in GABRA1 labeling in regions of the contralateral inferior colliculus in which high-frequency sound stimuli are represented. This localized region of reduced inhibitory receptor expression corresponds to the region in which hyperactivity of inferior colliculus neurons has been shown to develop after such treatments. The results strengthen the notion of a causal link between reduced GABRA1 expression and neural hyperactivity in central auditory nuclei and provide a possible mechanism for the development of phantom auditory sensations, or tinnitus.

Abatement efficiency and controlling strategy of a cylindrical and a conical fluidized bed flocculator

The aggregation efficiency of colloidal kaolin particles by the turbulence caused by random movement of silica gel beads in a cylindrical (CFB) and an 8 degrees conical fluidized bed (TFB) was studied in this paper, focusing on the control strategies of these novel processes. The abatement efficiencies as a function of the Camp number, velocity gradient (G) and flocculation time (T) were exploited. In general, the abatement efficiency tended to be improved with the increase of Camp number (in the study range of this work: Camp number lower than 8058 and 5639 in CFB and TFB, respectively). However, the efficiency was relatively low and sensitive to the Camp number as G was more than 186 s⁻¹ in CFB and 178 s⁻¹ in TFB, respectively. Whereas, increasing flocculation time clearly contributed to the improvement of the abatement efficiency, which is considered to be an effective strategy to enhance the treatment ability. Velocity gradient and flocculation time could be controlled by means of superficial liquid velocity and properties of packing particles. It should be noted that the backmixing in the TFB caused formed flocs to break and thus lower abatement efficiencies were found in the TFB than those in the CFB.

Scanning sonar of rolling porpoises during prey capture dives

Dolphins and porpoises have excellent biosonar ability, which they use for navigation, ranging and foraging. However, the role of biosonar in free-ranging small cetaceans has not been fully investigated. The biosonar behaviour and body movements of 15 free-ranging finless porpoises (Neophocaena phocaenoides) were observed using electronic tags attached to the animals. The porpoises often rotated their bodies more than 60 deg., on average, around the body axis in a dive bout. This behaviour occupied 31% of the dive duration during 186 h of effective observation time. Rolling dives were associated with extensive searching effort, and 23% of the rolling dive time was phonated, almost twice the phonation ratio of upright dives. Porpoises used short inter-click interval sonar 4.3 times more frequently during rolling dives than during upright dives. Sudden speed drops, which indicated that an individual turned around, occurred 4.5 times more frequently during rolling dives than during upright dives. Together, these data suggest that the porpoises searched extensively for targets and rolled their bodies to enlarge the search area by changing the narrow beam axis of the biosonar. Once a possible target was detected, porpoises frequently produced short-range sonar sounds. Continuous searching for prey and frequent capture trials appeared to occur during rolling dives of finless porpoises. In contrast, head movements ranging ±2 cm, which can also change the beam axis, were regularly observed during both dives. Head movements might assist in instant assessment of the arbitrary direction by changing the beam axis rather than prey searching and pursuit.

Evidence for internal structures of spiral turbulence

We present several observations into spiral turbulence in a Taylor-Couette geometry gained through a three-dimensional direct numerical simulation. Conditionally averaged flow statistics show the persistence of an azimuthal gradient of the mean flow across both the turbulent and laminar spirals, and distinct distribution features of the turbulent intensity. The data provide a physical picture qualitatively different from the existing model of spiral turbulence. Certain aspects of the spiral pattern are observed to bear similarities to the stationary laminar-turbulent pattern in plane Couette flow.

In vitro sequence-dependent interaction between paclitaxel and gefitinib in human lung cancer cell lines

e22025

Background: Cytotoxicity chemotherapy has been standard first line treatment for advanced NSCLC. Clinical trials comparing first line EGFR TKI therapy over cytotoxicity chemotherapy are under investigation in phase III trials. The aim of this study is to test the hypothesis that paclitaxel followed by gefitinib would be superior to the opposite order in EGFR TKI resistant cell lines because of cell signaling pathway and cell cycle interaction. Methods: we have used EGFR-TKI resistant human lung cancer cell lines A549, H1975 and H1650 as an in vitro model for defining the differential effects of opposite sequence of combination of cytotoxic drug and anti- EGFR agents on cell growth, signaling pathway, cell cycle distribution and induction of apoptosis. Results: Paclitaxel 24 hours followed by gefitinib 72 hours in A549, H1975 and H1650 cells produced synergistic effects, while the reverse sequence produced antagonistic effects. Exposure to paclitaxel resulted in an increased pEGFR and pAKT level, this increase of phosphorylation can be inhibited by the following gefitinib exposure, while the reverse sequence resulted in no change in EGFR and AKT phosphorylation. We confirmed that gefitinib arrested the cells in G1, paclitaxel arrested cells in S phase. The sequence of paclitaxel followed by gefitinib cause cells arrested in G1, while the reverse sequence cause cells arrested in S and G2 phase. Conclusions: These findings suggest that the sequence of paclitaxel followed by gefitinib may be superior to the reverse sequence in gefitinib resistant NSCLC, and support the investigation of these sequential treatment in the clinical setting. This work was supported by the grants from the National Natural Science Foundation of China (No. 30772531).

No significant financial relationships to disclose.

Kinetic analysis of experimental rabbit tumour and inflammation model with 18F-FDG PET/CT

Non-specific accumulation of 18F-FDG by both tumour and inflammatory lesions can make diagnostic analysis difficult. Our aim was to explore the difference in 18F-FDG uptake kinetics between tumour and inflammatory cells. To this end, we investigated VX2 tumour lesions and inflammatory lesions in rabbits.

METHODS

Six rabbits with VX2 tumour cells transplanted into one forelimb muscle and inflammatory lesions induced by turpentine oil in the contralateral forelimb were scanned for 60 minutes post 18F-FDG injection. Imaging data was analyzed with the standard 2-tissue-compartment model. Parameters, VB, Ki, K1, k2, k3, k4, were compared between tumour and inflammatory lesions. SUV and dual time scan methods were also compared in the experiment.

RESULTS

Time activity curves of VX2 tumour lesions showed a characteristic pattern of gradually increasing 18F-FDG uptake up to 60 min, whereas, 18F-FDG uptake in inflammatory lesions increased more slowly than in tumours. Parameters estimated from the uptake process showed that forward transport constant, K1, and influx constant, Ki, values in VX2 tumour lesions (0.186 +/- 0.053 and 0.048 +/- 0.014, respectively) was significantly higher than that in inflammatory lesions (0.129 +/- 0.024 and 0.022 +/- 0.007, respectively) (p < 0.05). In contrast, mean values of VB, k2, k3 and k4 derived from VX2 tumours were not significantly different from that of inflammatory lesions. SUVs at 60 minutes post 18F-FDG injection were also significantly higher in the VX2 tumor lesions than in the inflammatory lesions. Retention index (RI) was not significantly different between VX2 tumours and inflammatory lesions (1.134 +/- 0.076 vs. 1.060 +/- 0.058, p > 0.05).

CONCLUSION

Different kinetic parameters (Ki, K1, k3) exist between inflammatory and tumour lesions.

Partial dissociation of molecular and behavioral measures of song habituation in adult zebra finches

Initial playback of recorded birdsong triggers a number of responses in zebra finches, including overt listening behavior and ERK pathway-dependent activation of zenk gene transcription in the auditory lobule of the forebrain. Repetition of one song stimulus leads to persistent habituation of these responses, as measured by subsequent presentations 1 day later. In this study, we examined the causal relationships between behavioral and molecular (ERK/zenk) habituation. In a within-subject comparison, we found a strong correlation with the level of prior training for both responses (duration of behavioral listening and magnitude of zenk expression), but little correlation between these responses for birds within the same treatment group. We then tested the hypothesis that ERK/zenk activation during training is necessary for the development of habituation measured 1 day later. Cannula-directed infusion of a pharmacological inhibitor of ERK activation (U0126) immediately before training blocked the development of habituation of the zenk gene response. However, measurement of the effect on behavioral habituation was confounded because birds that were infused with a non-active drug analogue (U0124) showed a decreased response 1 day later, even to novel songs. We conclude that the behavioral response to song stimulation is strongly influenced by factors other than song familiarity, whereas the zenk response in the forebrain may be a more accurate indicator of actual experience hearing a particular song.

Estimation of the detection probability for Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis) with a passive acoustic method

Yangtze finless porpoises were surveyed by using simultaneous visual and acoustical methods from 6 November to 13 December 2006. Two research vessels towed stereo acoustic data loggers, which were used to store the intensity and sound source direction of the high frequency sonar signals produced by finless porpoises at detection ranges up to 300 m on each side of the vessel. Simple stereo beam forming allowed the separation of distinct biosonar sound source, which enabled us to count the number of vocalizing porpoises. Acoustically, 204 porpoises were detected from one vessel and 199 from the other vessel in the same section of the Yangtze River. Visually, 163 and 162 porpoises were detected from two vessels within 300 m of the vessel track. The calculated detection probability using acoustic method was approximately twice that for visual detection for each vessel. The difference in detection probabilities between the two methods was caused by the large number of single individuals that were missed by visual observers. However, the sizes of large groups were underestimated by using the acoustic methods. Acoustic and visual observations complemented each other in the accurate detection of porpoises. The use of simple, relatively inexpensive acoustic monitoring systems should enhance population surveys of free-ranging, echolocating odontocetes.

Elimination of vortex streets in bluff-body flows

We present an effective technique for suppressing the vortex-induced vibrations of bluff bodies by eliminating the von Kármán street formed in their wake. Specifically, we find that small amounts of combined windward suction and leeward blowing around the body modify the wake instability and lead to suppression of the fluctuating lift force. Three-dimensional simulations and stability analysis are employed to quantify our findings for the flow past fixed and flexibly mounted circular cylinders.

Association of misconceptions about HIV transmission and discriminatory attitudes in rural China

This study examined HIV-related knowledge and attitudes among 524 randomly selected adult residents from 12 rural Chinese communities where HIV infection among plasma donors has been reported. Most participants were familiar with the main routes of HIV transmission but had substantial misconceptions about risk of HIV transmission through casual social contacts. Higher score of misconception and being older and married independently predicted stronger discriminatory attitude. Intervention programs with focus on eliminating misconceptions about HIV transmission may reduce stigma.

Herringbone streaks in Taylor-Couette turbulence

We study near-wall streaks that form herringbonelike patterns in Taylor-Couette turbulence and in counter-rotating Taylor-Couette turbulence through three-dimensional direct numerical simulations. The orientation, axial distribution, onset, and tilting angle of these streaks are characterized.

Resonant vibrations of bluff bodies cause multivortex shedding and high frequency forces

A flexibly mounted circular cylinder in cross-flow, with natural frequencies in the inline and transverse directions having a ratio close to 2:1, exhibits drastic changes in the vortex structures in its wake, the frequency content of the fluid forces, and the orbital shape of its resulting motions. Stable multivortex patterns form in the cylinder wake, associated with large high-frequency force components.

Physical and functional interaction of Runt-related protein 1 with hypoxia-inducible factor-1alpha

Angiogenesis and hematopoiesis are closely linked and interactive with each other, but few studies were given to identify possible links between angiogenesis-promoting proteins and hematopoiesis-related transcription factors. Here we investigated the potential relationship of oxygen-sensitive alpha-subunit of angiogenesis-related hypoxia-inducible factor-1alpha (HIF-1alpha) with Runt-related protein 1 (Runx1, also known as acute myeloid leukemia-1, AML-1), an important hematopoietic transcription factor. The results demonstrated that Runx1 and HIF-1alpha proteins directly interacted with each other to a degree, in which Runt homology domain of Runx1 was mainly involved. Leukemia-related abnormal Runx1 fusion protein AML1-ETO, which fuses the N-terminal 177 amino acid residues of the Runx1 protein in frame to ETO (eight-twenty-one) protein, also interacted with HIF-1alpha protein with greater ability than Runx1 itself. More intriguingly, Runx1 overexpression inhibited DNA-binding and transcriptional activity of HIF-1 protein with reduced expression of HIF-1-targeted genes such as vascular endothelial growth factor, while silence of Runx1 expression by specific small interfering RNA significantly increased transcriptional activity of HIF-1 protein, suggesting that Runx1 inhibited transcription-dependent function of HIF-1. Vice versa, HIF-1alpha increased DNA-binding ability and transcriptional activity of Runx1 protein. All these data would shed new insight to understanding Runx1 and HIF-1alpha-related hematopoietic cell differentiation and angiogenesis.

Increased calcium deposits and decreased Ca2+-ATPase in right ventricular myocardium of ascitic broiler chickens

Right ventricular hypertrophy and failure is an important step in the development of ascites syndrome (AS) in broiler chickens. Cytoplasmic calcium concentration is a major regulator of cardiac contractile function and various physiological processes in cardiac muscle cells. The purpose of this study was to measure the right ventricular pressure and investigate the precise ultrastructural location of Ca(2+) and Ca(2+)-ATPase in the right ventricular myocardium of chickens with AS induced by low ambient temperature. The results showed that the right ventricular diastolic pressure of ascitic broilers was significantly higher than that of control broilers (P < 0.01), and the maximum change ratio of right intraventricular pressure (RV +/- dp/dt(max)) of ascitic broilers was significantly lower than that of the controls (P < 0.01). Extensively increased calcium deposits were observed in the right ventricular myocardium of ascitic broilers, whereas in the age-matched control broilers, calcium deposits were much less. The Ca(2+)-ATPase reactive products were obviously found on the sarcoplasmic reticulum and mitochondrial membrane of the control right ventricular myocardium, but rarely observed in the ascitic broilers. The data suggest that in ascitic broilers there is the right ventricular diastolic dysfunction, in which the overload of intracellular calcium and the decreased Ca(2+)-ATPase activity might be the important factors.

Electric field induced collapse of the charge-ordered phase in manganites

The colossal electroresistance in manganites accompanies the insulator-to-metal phase transition induced by the electric field. A phenomenological phase transition model is proposed to study this electric field induced collapse of the charge-ordered phase. The hysteresis of the phase transition is well explained using the effective medium approximation. The volume fraction of the metallic region at the metal-to-insulator transition point is estimated as 30%.

B7-H1 expression is upregulated in peripheral blood CD14+ monocytes of patients with chronic hepatitis B virus infection, which correlates with higher serum IL-10 levels

Chronicity in hepatitis B virus (HBV) infection is maintained by increased type 2 T-helper cell response, possibly because of increased interleukin-10 (IL-10) productions. B7-H1 can negatively regulate T-cell responses via its receptor, programmed death 1. Ligation of B7-H1 to T-cells can result in the preferential secretion of IL-10. In this study, we investigated whether there was an upregulated expression of B7-H1 in peripheral blood mononuclear cells in patients chronically infected by HBV and further explored the correlation between B7-H1 expression and serum interleukin 2, interferon-gamma, IL-10, HBeAg, alanine aminotransferase (ALT) levels and viral load. Fifty-five patients with chronic HBV infection and 20 healthy controls (HCs) were enrolled in the present study. The results showed that in patients with chronic hepatitis B CD14+ monocytes but not CD3+ and CD19+ cells had a significantly increased expression of B7-H1 compared with HCs, which positively correlates with serum IL-10 levels and the presence of HBeAg and negatively correlates with serum ALT levels. In conclusion, chronic HBV patients harbour an increased B7-H1 expression in CD14+ monocytes compared with controls, which may be responsible for the increased serum IL-10 levels. This might be an important way by which HBV evades an adequate immune response, leading to viral persistence and disease chronicity.

Mycophenolic Acid Upregulates B7-DC Expression on Dendritic Cells, Which Is Associated With Impaired Allostimulatory Capacity of Dendritic Cells

In addition to its effects on lymphocytes, mycophenolic acid (MPA) may inhibit the allostimulatory capacity of dendritic cells (DC) via unknown mechanisms. B7-H1 and B7-DC surface markers on DC negatively regulate T-cell responses via the receptor PD-1. In this study, we sought to investigate whether B7-H1 and B7-DC are responsible for the inhibitory functions of MPA on DC. Mouse bone marrow-derived DC were cultured with recombinant granulocyte macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4 in the presence or absence of MPA (0.01 micromol and 0.1 micromol). The DC phenotype was assessed by flow cytometry, their immunostimulatory capacity measured by mixed lymphocyte reaction (MLR), and cytokine production by ELISA. The results showed that MPA not only inhibited the expression of major histocompatibility complex (MHC) class II and costimulatory molecules CD80 and CD86 but upregulated B7-DC expression on mature DC induced by LPS. These findings were associated with a reduced allostimulatory ability and an altered cytokine secretion pattern of DC. Thus, we suggest that MPA upregulates B7-DC expression during DC maturation induced by LPS in vitro, an effect that may be responsible for MPA-mediated inhibitory effects on the allostimulatory capacity of DC.

Aberrant termination triggers nonsense-mediated mRNA decay

NMD (nonsense-mediated mRNA decay) is a cellular quality-control mechanism in which an otherwise stable mRNA is destabilized by the presence of a premature termination codon. We have defined the set of endogenous NMD substrates, demonstrated that they are available for NMD at every round of translation, and showed that premature termination and normal termination are not equivalent biochemical events. Premature termination is aberrant, and its NMD-stimulating defects can be reversed by the presence of tethered poly(A)-binding protein (Pab1p) or tethered eRF3 (eukaryotic release factor 3) (Sup35p). Thus NMD appears to be triggered by a ribosome's failure to terminate adjacent to a properly configured 3'-UTR (untranslated region), an event that may promote binding of the UPF/NMD factors to stimulate mRNA decapping.

Decreased intranuclear mobility of acute myeloid leukemia 1-containing fusion proteins is accompanied by reduced mobility and compartmentalization of core binding factor beta

Acute myeloid leukemia 1 (AML1) gene on chromosome 21 is involved in several chromosomal translocations, including t(8;21) and t(16;21), that produce chimeric fusion proteins AML1-eight twenty-one (ETO) and AML-myeloid transforming gene chromosome 16 (MTG16), which contribute to leukemogenesis. The molecular basis for the leukemogenic effects of these fusion proteins is incompletely understood. Using gel-shift assay, we showed that AML1-ETO and AML1-MTG16 bound to a series of AML1 consensus DNA-binding sites with different affinities. Using fluorescence recovery after photobleaching (FRAP), we demonstrated that a fusion of AML1 with ETO or MTG16 exhibits reduced intranuclear mobility compared with wild-type AML1 or either fusion partner. The dimerization domain (nervy homology region 2) of ETO is responsible for the reduced mobility of AML1-ETO. Dual FRAP studies revealed that CBFbeta colocalized with AML1-ETO within the nucleus, resulting in reduced mobility of CBFbeta. Therefore, AML1 fusion proteins may interfere with normal AML1 function due to aberrant nuclear dynamics, which leads to spatial and temporal sequestration of CBFbeta and perhaps other coregulators critical for myeloid differentiation.

Morphological alteration and biological properties of hepatocytes not related to tumorigenesis following transfection with HCV core protein

The hepatitis C virus (HCV) core protein is supposed to play a critical role in HCV-mediated human liver disease with its capabilities to regulate the growth rate of hepatocytes and to partially contribute to the pathogenesis of hepatocellular carcinoma in association with cellular oncogenes. In this study, to analyse the possible pathological mechanism of the HCV core protein, human primary embryo hepatocytes transfected with HCV core were monitored by immunofluorescence, reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot. The morphological changes and biological properties of the transfected hepatocytes were also studied. The results showed that the HCV core gene integrated in the cellular genome and the protein expressed in the transfected hepatocyte, could be detected following serial passage at both the mRNA and protein level. The proliferation assays indicated that hepatocytes transfected with the HCV core gene alone did not exhibit any tumorigenic tendency. Meanwhile, the morphological alterations of these cells demonstrated obvious changes in size, and large vacuolar degeneration. In conclusion, the hepatocytes transfected with the HCV core gene revealed that the core protein expressed induced pathological changes of degeneration, probably related indirectly to tumorigenicity.

Identification of a novel human sand family protein in human fibroblasts induced by herpes simplex virus 1 binding

Studies on interaction between Herpes simplex virus 1 (HSV-1) and human fibroblasts KMB-17 have demonstrated that HSV-1 binding to the cell surface could induce a specific gene response. In this study, the HSV-1 stimulation-related gene 1 (HSRG1), a new so far unknown gene function of cellular response induced by a specific stimulation with HSV-1, was cloned from the cDNA library established from mRNA of early gene response of KMB-17 cells. The gene product consisted of 547 amino acids and had a significant homology, in six eukaryotic species. On the basis of its structure it was identified as a member of the SAND protein family. The HSRG1 protein was fused with glutathione S-transferase (GST) and expressed in Escherichia coli DHPalpha strain under the control of T7 promoter. An antibody to HSRG1 raised in mice was used to detect expression of the HSRG1 protein in KMB-17 cells stimulated by HSV-1 by an immunoprecipitation assay. It was found that the HSRG1 protein was induced in these cells by HSV-1 at high level.