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. Purpose: To explore the effect of glucosamine (GlcN) on transforming growth factor (TGF)-β signalling and several processes involved in proliferative vitreoretinopathy (PVR). Methods: We evaluated the surface levels of TGF-β receptor and its binding of TGF-β in ARPE-19 cells. Release of cytokines and collagen, and expression of signalling intermediates were quantified. Migration was qualitatively and quantitatively examined. The morphology of cells undergoing PVR in vitro and in a mouse PVR model was observed. Results: Glucosamine reduced the surface levels of TGF-β receptor and the ability of ARPE-19 cells to bind TGF-β. In ARPE-19 cells, TGF-β1 plus epidermal growth factor (EGF) or TGF-β2 increased the expression of alpha-smooth muscle actin (α-SMA) and decreased the expression of zona occludens protein (ZO-1). Transforming growth factor-(β2) also caused the release of platelet-derived growth factor (PDGF), connective tissue growth factor (CTGF) and type 1 collagen and increased the phosphorylation of SMAD2 and SMAD3. Platelet-derived growth factor and CTGF stimulated cell migration, and TGF-β2 stimulated wound closure, contraction of collagen and changes in cell morphology. Conclusions: Treatment with GlcN counteracted all of these effects, and its administration in the mouse model reduced the morphologic appearance of PVR. Glucosamine could inhibit the TGF-β signalling pathway in retinal pigment epithelium cells and several of the downstream events associated with epithelial-mesenchymal transition and PVR. [ABSTRACT FROM AUTHOR]

Human induced pluripotent stem cells (hiPSCs) provide new possibilities for regenerative therapies. In order for this potential to be achieved, it is critical to efficiently monitor the differentiation of these hiPSCs into specific lineages. Here, we describe a lentiviral reporter vector sensitive to specific microRNAs (miRNA) to show that a single vector bearing multiple miRNA target sequences conjugated to different reporters can be used to monitor hiPSC formation and subsequent differentiation from human fetal fibroblasts (HFFs). The reporter vector encodes EGFP conjugated to the targets of human embryonic stem cell (hESC) specific miRNAs (miR-302a and miR-302d) and mCherry conjugated to the targets of differentiated cells specific miRNAs (miR-142-3p, miR-155, and miR-223). The vector was used to track reprogramming of HFF to iPSC. HFFs co-transduced with this reporter vector and vectors encoding 4 reprogramming factors (OCT4, SOX2, KLF4 and cMYC) were mostly positive for EGFP (67%) at an early stage of hiPSC formation. EGFP expression gradually disappeared and mCherry expression increased indicating less miRNAs specific to differentiated cells and expression of miRNAs specific to hESCs. Upon differentiation of the hiPSC into embryoid bodies, a large fraction of these hiPSCs regained EGFP expression and some of those cells became single positive for EGFP. Further differentiation into neural lineages showed distinct structures demarcated by either EGFP or mCherry expression. These findings demonstrate that a miRNA dependent reporter vector can be a useful tool to monitor living cells during reprogramming of hiPSC and subsequent differentiation to lineage specific cells. [ABSTRACT FROM AUTHOR]

Steady-state absorption and emission and femtosecond time-resolved emission spectroscopy of two benzylidene malononitriles, 2-[4-(dimethylamino)benzylidene])malononitrile (DMN) and julolidinemalononitrile (JDMN), are reported in a variety of room-temperature solvents. Solvatochromic shifts of these molecules are consistent with dielectric continuum descriptions and an S1−S0dipole moment change of 8.5 D. Time-resolved spectra show modest dynamic Stokes shifts of ∼1000 cm−1occurring independently of fluorescence decay, which takes place in 0.5−5 ps in most room-temperature solvents. Absorption transition moments and fluorescence decay times are used to determine radiative rate constants: krad= 0.32 ± 0.02 ns−1in DMN and 0.28 ± 0.02 ns−1in JDMN, assumed to be independent of solvent. Quantum yield data together with these radiative rates provide the reaction rate constants krxnassociated with the internal conversion process of these molecules in 33 representative solvents at 298 K and in several solvents as functions of temperature. Reaction rates of JDMN are systematically lower than those of DMN by a factor of 2.0. Values of krxnin series of homologous solvents or in a single solvent at different temperatures are correlated to solvent viscosity η and temperature Tin the manner krxn/T∝ η−pwith exponents 0.2 ≤ p≤ 0.8. Solvent polarity appears to influence these reactions such that for a given viscosity reaction in high polarity solvents is significantly slower than in nonpolar solvents. However, this conclusion is predicated on the assumption that reactive friction is identical in solvents of the same viscosity, which is unlikely to be quantitatively correct. The observed reaction rates and their solvent dependence are discussed in terms of isomerization about the CC bond occurring on a shelf-like potential. [ABSTRACT FROM AUTHOR]

We recently developed a novel targeting Sindbis virus envelope pseudotyped lentiviral vector, 2.2ZZ, which acquires specific transduction capacity by antibody conjugation and binding with specific antigens on the surface of targeted cells. Here we characterize the virological properties of this vector by examining its targeting to CD4 antigen. Our results show that entry is dependent on CD4 cell surface density and occurs via the clathrin-mediated endocytic pathway. These findings provide insight into the mechanism of infection by a new viral vector with combined properties of Sindbis virus and lentiviruses and infectivity conferred by monoclonal antibody-ligand interactions. [ABSTRACT FROM AUTHOR]

AbstractIt is well recognized that brain death starts to occur just 4–6 min after cardiac arrest, and few attempts at resuscitation succeed after 10 min of severe cerebral ischemia and anoxia. We sought to determine the therapeutic window of selective cerebral profound hypothermia of primates following severe cerebral ischemia in primates. Fourteen rhesus monkeys with severe cerebral ischemia were divided into four groups: normothermia (n = 3); profound hypothermia I (n = 4), with cooling initiated 10 min after ischemia; profound hypothermia II (n = 4), with cooling initiated 15 min after ischemia; and profound hypothermia III (n = 3), with cooling initiated 20 min after ischemia. Severe cerebral ischemia was induced by clamping both the internal and external carotid arteries, as well as the internal and external jugular veins. Profound cerebral hypothermia (15.8° ± 0.9°C) was achieved and maintained for 60 min, and the animals were then re-warmed gradually. All four animals in hypothermia group I survived without any neurological deficits. Only 1 animal survived and 3 animals died in hypothermia group II. All 4 animals died in both hypothermia group III and the normothermia group. Neurological functions were normal in all surviving animals, and MRI scans showed no cerebral infarction in these animals. Microscopic examination showed no injured neurons in the hippocampus and cerebral cortex of the surviving animals, and showed that the heart, lung, liver, and kidneys were normal in these animals. Our data indicate that post-ischemic profound cerebral hypothermia provided significant cerebral protection with no systemic complications, and that the effective therapeutic window is more than 10 min, but less than 15 min, after severe cerebral ischemia. [ABSTRACT FROM AUTHOR]

Abstract: The use of organoborane intermediates for radiohalogenations is briefly reviewed. The synthesis of an iodine-123 labeled curcumin derivative using a newly developed radio-iodination technique is reported. [Copyright &y& Elsevier]

Abstract: To develop a small molecule-based tracer for in vivo apoptosis imaging, dansylhydrazone (DFNSH) was synthesized in 93% yield in less than 30min. The biological evaluation showed that DFNSH selectively binds to paclitaxel-induced apoptotic cancer cells. The high magnification fluorescent images demonstrate that DFNSH is localized within the cytoplasm of cells that bound Alexa® 488 labeled annexin V on the plasma membrane. [18F]-DFNSH ([18F]-3) was synthesized and isolated in 50–60% radiochemical yields, based on [K/K222]18F, with a synthesis time of 50min (EOB). The straightforward preparation of fluorine-18 labeled 3 makes it a promising tracer for PET imaging of apoptosis. [Copyright &y& Elsevier]

1. In previous work, phytoplankton regulation in freshwater lakes has been associated with many factors. Among these, the ratio of total nitrogen to total phosphorus (TN : TP) has been widely proposed as an index to identify whether phytoplankton are N- or P-limited. From another point of view, it has been suggested that planktivorous fish can be used to control phytoplankton. 2. Large-scale investigations of phytoplankton biomass [measured as chlorophyll a, (chl- a)] were carried out in 45 mid-lower Yangtze shallow lakes to test hypotheses concerning nutrient limitation (assessed with TN : TP ratios) and phytoplankton control by planktivorous fish. 3. Regression analyses indicated that TP was the primary regulating factor and TN the second regulating factor for both annual and summer phytoplankton chl- a. In separate nutrient–chl- a regression analyses for lakes of different TN : TP ratios, TP was also superior to TN in predicting chl- a at all particular TN : TP ranges and over the entire TN : TP spectrum. Further analyses found that chl- a : TP was not influenced by TN : TP, while chl- a : TN was positively and highly correlated to TP : TN. 4. Based on these results, and others in the literature, we argue that the TN : TP ratio is inappropriate as an index to identify limiting nutrients. It is almost impossible to specify a ‘cut-off’ TN : TP ratio to identify a limiting nutrient for a multi-species community because optimal N : P ratios vary greatly among phytoplankton species. 5. Lakes with yields of planktivorous fish (silver and bighead carp, the species native to China) >100 kg ha−1 had significantly higher chl- a and lower Secchi depth than those with yields <100 kg ha−1. TP–chl- a and TP–Secchi depth relationships are not significantly different between lakes with yields >100 kg ha−1 or <100 kg ha−1. These results indicate that the fish failed to decrease chl- a yield or enhance ZSD. Therefore, silver carp and bighead carp are not recommended as a biotic agent for phytoplankton control in lake management if the goal is to control the entire phytoplankton and to enhance water quality. [ABSTRACT FROM AUTHOR]

A boron trihalide mediated alkyne-aldehyde coupling reaction leading to stereodefined 1,3,5-triaryl-l,5- dihalo-1,4-pentadienes is described. The study led to the discovery of a direct substitution of hydroxyl groups by stereodefined alkenyl moieties using alkenylboron dihalides. During the investigation, it was also discovered that, at low temperatures, the reaction of BCI3 with alkynes produces monovinylboron dichioride rather than the reported divinylboron chloride. A modified reaction mechanism for the boron trichloride mediated alkyne-aldehyde coupling reaction is now proposed. The reaction temperature and mode of addition have been found to have dramatic affects on the stereochemistry of the diene products. [ABSTRACT FROM AUTHOR]

In this study, the problem of a planar blast wave in a duct with a sudden expansion is considered. An incident blast wave that contains two shock waves is arranged so that one pair of vortex rings induced by the first shock wave interacts with the second shock wave of the blast wave and with the reflected shock associated with the first shock wave. A high-resolution Euler/Navier-Stokes soiver using a fifth-order weighted essentially nonoscillation scheme is employed to investigate the problem. After the Euler/Navier-Stokes solver is validated to be reasonably accurate, the flow fields induced by the shock/vortex interactions are investigated by computational shadowgraph and computational schlieren techniques. It is found that the trajectories formed by major ring-vortex centers may be different case by case, depending on the arrival time sequence of the second shock wave and the reflected shock wave. In particular, a third vortex ring may be developed, causing the trajectory's turn at some critical time in viscous-flow models. Because of viscous dissipation, consequently stronger vortex-ring strength predicted by the inviscid-flow model than that for the viscous-flow model can result in 14-32% lower pressures at the major ring-vortex centers in the inviscid flow compared with the turbulent flow during the time interval investigated for case A, and 20-32% for case B, and 21-38% for case C. Because of the boundary layer development along the duct wall after the sudden expansion, the reflection type of the first shock wave is changed from a regular reflection in the inviscid-flow case to a single Mach reflection that directly affects the arrival time of the reflected shock wave at the sharp corner. Moreover, the mechanism of the vortex ring formation based on the inviscid-flow model is analyzed. It is found that the term due to the dilation effect also plays a more important role in vorticity generation than the baroclinic term. [ABSTRACT FROM AUTHOR]

BACKGROUND: Because metallothionein (MT) is a metal-binding protein that protects against metal intoxication, it could be a biomarker for individual sensitivity to metal toxicity. OBJECTIVE: We assessed the use of bloodborne MT transcript as a reflection of tissue MT levels and examined the potential role of MT in arsenic toxicity in an environmentally exposed human population. METHOD: Rodents were treated with zinc or nonmetallic MT inducers for 4 days, and the blood and tissues were collected for MT transcript analysis by real-time reverse transcriptase--polymerase chain reaction and MT protein determination by the cadmium--hemoglobin assay. Blood and buccal cell samples were collected from arsenicosis patients and healthy subjects residing in Guizhou, China, and total RNA was isolated for MT transcript analysis. RESULTS: There was a positive correlation between blood MT-1 and MT-2 transcripts and corresponding hepatic or renal MT transcript levels in rats and mice. Furthermore, there was a positive correlation between blood MT-1 and MT-2 transcript and tissue MT protein levels in these animals. A positive correlation also occurred between human blood MT and buccal cell MT transcript levels. MT-1A and MT-2A were the major isoform transcripts in human blood and buccal cells, and significantly lower MT levels were seen in arsenicosis patients compared with healthy subjects. CONCLUSIONS: Blood MT transcript appears to be a useful biomarker of tissue MT levels. Arsenicosis patients in Guizhou show significantly lower MT transcript levels in blood, which may have predisposed this population to arsenic intoxication. [ABSTRACT FROM AUTHOR]

Aim: Through a preliminary test on a novel protein containing an HIV1-TAT domain and a SH3 domain of oncoprotein P210BCR-ABL (we named it after PTD-BCR/ABL SH3), we found that this protein shows inhibition activity of hepatocarcinoma cell HepG-2. The purpose of the present study is to explore the biological behavior of PTD-BCR/ABL SH3 fusion protein in hepatocarcinoma cells in vitro and in vivo. Methods: HepG-2 cells were cocultured with the fusion protein for the indicated time and studied in vitro by immunocytochemistry staining to demonstrate the localization of the protein, light and electron microscope observation in morphology research, MTT assay to draw a growth curve and to analyze inhibition ratio, DNA ladder and TUNEL staining to study apoptosis. Nude mice bearing HepG-2 tumors were used to test the antitumor activity of the fusion protein. Results: PTD-BCR/ABL SH3 fusion protein successfully entered into HepG-2 cells and localized in the nucleus. The protein had shown high cytotoxity through inducing HepG-2 cells to apoptosis, and in vivo. The growth speed of tumors in the treatment group was distinctly slower than those in the control group, and the survival time of mice in the treatment group was longer than those in the control group. The growth of the tumors had been inhibited in the treatment group, while other tissues, such as heart, liver, lung and kidney displayed normal morphology. Conclusion: PTD-BCR/ABL SH3 fusion protein displays significant inhibitory activity of inducing hepatocarcinoma HepG-2 cells to apoptosis in vitro. It also showed therapeutic effects in vivo. [ABSTRACT FROM AUTHOR]

MicroRNAs are small noncoding RNA molecules that control expression of target genes. Our previous studies show that mir-21 is overexpressed in tumor tissues compared with the matched normal tissues. Moreover, suppression of mir-21 by antisense oligonucleotides inhibits tumor cell growth both in vitro and in vivo. However, it remains largely unclear as to how mir-21 affects tumor growth, because our understanding of mir-21 targets is limited. In this study, we performed two-dimensional differentiation in-gel electrophoresis of tumors treated with anti-mir-21 and identified the tumor suppressor tropomyosin 1 (TPM1) as a potential mir-21 target. In agreement with this, there is a putative mir-21 binding site at the 3′-untranslated region (3′-UTR) of TPM1 variants V1 and V5. Thus, we cloned the 3′-UTR of TPM1 into a luciferase reporter and found that although mir-21 down-regulated the luciferase activity, anti-mir-21 up-regulated it. Moreover, deletion of the mir-21 binding site abolished the effect of mir-21 on the luciferase activity, suggesting that this mir-21 binding site is critical. Western blot with the cloned TPM1-V1 plus the 3′-UTR indicated that TPM1 protein level was also regulated by mir-21, whereas real-time quantitative reverse transcription-PCR revealed no difference at the mRNA level, suggesting translational regulation. Finally, overexpression of TPM1 in breast cancer MCF-7 cells suppressed anchor- age-independent growth. Thus, down-regulation of TPM1 by mir-21 may explain, at least in part, why suppression of mir-21 can inhibit tumor growth, further supporting the notion that mir-21 functions as an oncogene. [ABSTRACT FROM AUTHOR]

A new unusual pigment with a novel carbon framework named selaginellin (1) was isolated from the acetone extract of Selaginella sinensis, and its methoxy derivative (1a) was synthesized. Both selaginellin 1 and la are racemic com- pounds. The structure of selaginellin 1 was established as (R,S)-4-[(4′-hydroxy-4-(hydroxymethyl)-3-((4-hydroxyphenyl)ethynyl)biphenyl-2-yl)(4-hydroxyphenyl)methylenel-2,5-cyclohexadien-1-one and la as (R,S)-4-[(4′-methoxy-4-(methoxymethyl)-3-((4-methoxyphenyl)ethynyl)biphenyl-2-yl)(4-methoxyphenyl)methylenel-2,5-cyclohexadien-1-one by the analysis of one- and two-dimensional NMR data, HR-ESIMS, El-MS. IR, UV, CD, and single-crystal X-ray experiments, and the mechanism of their color change according to different pH values and fluorescent properties was studied. [ABSTRACT FROM AUTHOR]

Recent progress has been made on the role of oncoproteins c-Ski and related SnoN in the control of cellular transformation. c-Ski/SnoN potently repress transforming growth factor-α (TGF-β) antiproliferative signaling through physical interaction with signal transducers called Smads. Overexpression of c-Ski/SnoN also induces skeletal muscle differentiation, but how c-Ski/SnoN function in myogenesis is largely unknown. During our investigation on the role of sumoylation in TGF-β signaling, we inadvertently found that SnoN is modified by small ubiquitin-like modifier-1 (SUMO-1). Here, we biochemically characterize SnoN sumoylation in detail and report the physiological function of the modification. Sumoylation occurs primarily at lysine 50 (Lys-50). PIAS1 and PIASx proteins physically interact with SnoN to stimulate its sumoylation, thus serving as SUMO-protein isopeptide ligases (E3) for SnoN sumoylation. SnoN sumoylation does not alter its metabolic stability or its ability to repress TGF-β signaling. Notably, loss of sumoylation in the Lys-50 site (via a Lys-to-Arg point mutation) potently activates muscle-specific gene expression and enhances myotube formation. Our study suggests a novel role for SUMO modification in the regulation of myogenic differentiation. [ABSTRACT FROM AUTHOR]

The exact mechanism underlying regional cerebral hypoperfusion in the early phase of Alzheimer's disease (AD) is not understood. We have shown in isolated porcine cerebral arteries that stimulation of sympathetic α7-nicotinic acetylcholine receptors (α7-nAChRs) causes release of nitric oxide in parasympathetic nitrergic nerves and vasodilation. We therefore examined if β-amyloid peptides (Aβs), which play a key role in pathogenesis of AD, blocked sympathetic α7-nAChRs leading to reduced neurogenic nitrergic dilation in isolated porcine basilar arteries, using in vitro tissue bath, calcium image, and patch clamping techniques. The results indicated that Aβ1−40, but not Aβ40−1, blocked relaxation of endothelium-denuded basilar arterial rings induced by nicotine (100 μmol/L) and choline (1 mmol/L) without affecting that induced by sodium nitroprusside or isoproterenol. In cultured superior cervical ganglion (SCG) cells, Aβ1−40, but not Aβ40−1, blocked choline- and nicotine-induced calcium influx and inward currents. The Aβ blockade of the nitrergic vasodilation and inward currents, but not that of calcium influx, was prevented by acute pretreatment with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors mevastatin and lovastatin. These results suggest that Aβ1−40 blocks cerebral perivascular sympathetic α7-nAChRs, resulting in the attenuation of cerebral nitrergic neurogenic vasodilation. This effect of Aβ may be responsible in part for cerebral hypoperfusion occurred in the early phase of the AD, which may be prevented by statins most likely because of their effects independent of cholesterol lowering. Statins may offer an alternative strategy in the prevention and treatment of AD.Journal of Cerebral Blood Flow & Metabolism (2005) 25, 1573–1585. doi:10.1038/sj.jcbfm.9600232; published online 28 September 2005 [ABSTRACT FROM AUTHOR]

The problem of planar reflected-shock/spiral-vortex interactions near an open-ended duct is considered. The reflected shock is formed after exiting the duct and impinging on a vertical wall that is located downstream of the duct. Two cases associated with the shock diffraction around the duct exit are investigated for understanding the detailed flow structure and acoustic waves due to the reflected shock/spiral-vortex interaction. One is a 90-deg diffraction; the other is a 180-deg diffraction. An Euler solver with a high-resolution scheme of weighted essential nonoscillation is used to study these complicated flow problems. The Euler solver is validated to be reasonably accurate by comparing the computed solution with experimental data. For the study of reflected-shock/spiral-vortex interactions, the techniques of computational shadowgraph, computational schlieren image, and computational interferometry are used. Detailed flow structures of reflected shock/vortex interactions are reported for different incident shock Mach numbers. An interesting result of stagnant reflected shock waves downstream of the duct is found for an incident shock Mach number equal to or greater than 1.4. For the incident shock Mach number below this critical value, the reflected shock Rt will eventually enter the duct. The mechanism for the formation of acoustic waves generated by reflected-shock/vortex interactions is analyzed. [ABSTRACT FROM AUTHOR]

A novel boronated aminocyclobutanecarboxylic acid (1) was synthesized for potential use in boron neutron capture therapy. Starting from the readily available 3-(bromomethyl)cyclobutanone ketal (4), several synthetic routes to I were evaluated. After several unsuccessful attempts with traditional synthetic methods, a novel synthetic strategy to generate the new boronated cyclic amino acid was developed. The tolerance of the hydantoin group to the selenoxide elimination reaction conditions in the preparation of alkenyl compound 7 proved to be the key step in the new strategy. [ABSTRACT FROM AUTHOR]

The tumor suppressor, Smad4/DPC4, is a common signal transducer in transforming growth factor-β (TGF-β) signaling. In this study, we demonstrated that the protein inhibitor of activated STAT1 (PIAS1) regulates the signaling potential of Smad4 through a sumoylation-dependent mechanism. PIAS1 was shown to be an E3 ligase for Smad4 sumoylation in vitro and in vivo. PIAS1 physically interacted with Smad4 in a TGF-β-inducible manner. A minimal SUMO E3 ligase domain and Smad4binding domain were defined on PIAS1 protein. The RING finger domain of PIAS1 was essential for its E3 ligase function. Although PIAS1 enhanced the Smad4dependent transcriptional activation of TGF-β signaling, a mutant lacking the RING domain inhibited the sumoylation of Smad4 in a dominant negative manner and, as a result, abolished the transcriptional response of TGF-β. These data demonstrate that PIAS1 protein positively modulates TGF-β responses as a SUMO E3 ligase for Smad4. [ABSTRACT FROM AUTHOR]

We have previously shown that transactivation-proficient hepatitis virus B X protein (HBx) protects Hep 3B cells from transforming growth factor-β (TGF-β)-induced apoptosis via activation of the phosphatidylinosiroi 3-kinase (PI 3-kinase)/Akt signaling pathway. This work further investigated how HBx activates PI 3-kinase. Src activity was elevated in Hep 3B cells following expression of transactivation-proficient HBx or HBxGFP fusion proteins. The Src family kinase inhibitor PP2 and C-terminal Src kinase (Csk) both alleviated HBx-mediated PI 3-kinase activation and protection from TGF-β-induced apoptosis. Therefore, HBx actirated a survival signal by linking Src to PI 3-kinase. Systemic subcellular fractionation and membrane flotation assays indicated that ∼1.5% of ectopically expressed HBxGFP was associated with periplasmic membrane where Src was located. However, neither nucleustargeted nor periplasmic membrane-targeted HBxGFP was able to upregulate Src activity or to augment PI 3-kinase survival signaling pathway. [ABSTRACT FROM AUTHOR]

Tumor suppressor Smad4/DPC4 is a central intracellular signal transducer for transforming growth factor-β (TGF-β) signaling. We recently reported that transcriptional potential of Smad4 was regulated by SUMOylation in transfected HeLa cells (1), but the precise mechanism and function of Smad4 SUMOylation in TGF-β signaling remain to be elucidated. Here, we describe the regulation of TGF-β signaling by SUMOylation through the control of Smad4 metabolic stability and subcellular localization. We found that SUMO-1 overexpression strongly increases Smad4 levels, while inhibition of SUMOylation by small interfering RNA (siRNA)-mediated knockdown of the E2 enzyme Ubc9 reduces endogenous Smad4 levels. Concomitantly, SUMO-1 overexpression enhances and Ubc9 knockdown reduces levels of intranuclear Smad4, growth inhibitory response, as well as transcriptional responses to TGF-β. Comparison of wild type and mutant forms of Smad4 for SUMOylation, ubiquitination, and half-life allows the conclusion that SUMO-1 modification serves to protect Smad4 from ubiquitin-dependent degradation and consequently enhances the growth inhibitory and transcriptional responses of Smad4. [ABSTRACT FROM AUTHOR]

The effects of polyamines (spermine or spermidine) and DFMO (an ornithine decarboxylase inhibitor) on the infection of LM (tk−) cells by pseudorabies virus (PRV) were investigated. Results from radioactive methionine labeling showed that the synthesis of viral proteins was not affected; however, the expression of a distinctive cellular protein (∼27 kDa) was induced after the treatment of spermine or spermidine. Using plaque assay, we found that the plaque formation of PRV was not affected by these three reagents either. Furthermore, the effects of these drugs on the transcription of PRV immediate-early gene (IE) promoter were examined by CAT assay, and results showed weak stimulation of transcription by these drugs. Taken together, our results demonstrated that lytic infection of PRV was not influenced by addition of exogenous polyamines or depletion of endogenous polyamines; this conclusion was similar to earlier studies by using herpes simplex virus. [Copyright &y& Elsevier]

Investigates the activation of transforming growth factor-beta (TGF-beta) signaling through the involvement of small ubiquitin-like modifier-1 modification of tumor suppressor Smad4/DPC4. Association between the MH1 domain of Smad4 with a carrier protein conjugating enzyme; Observation on the mutation ability of lysine residues in altering conjugation; Enhancement of TGF-beta-induced transcription process.

Interleukin-6 (IL-6) has received particular attention in the pathogenesis of cervical cancer, although the underlying mechanism remains elusive. This study revealed that IL-6 promotes in vivo tumor growth of human cervical cancer C33A cells, but does not substantially alter their in vitro growth kinetics. The in vivo angiogenic assays showed that IL-6 increases angiogenic activity in human cervical cancer cells, an effect that is specifically associated with upregulation of vascular endothelial growth factor (VEGF). Also, using anti-VEGF antibody to block VEGF function significantly inhibited IL-6-mediated angiogenesis and tumor growth in nude mice, strongly supporting the critical role of VEGF in the IL-6-mediated cervical tumorigenesis. Accordingly, the signaling pathway downstream of IL-6/IL-6R responsible for the regulation of VEGF was investigated. Notably, pharmacological inhibition of PI3-K or MAPK failed to inhibit IL-6-mediated transcriptional upregulation of VEGF. Meanwhile, blocking STAT3 pathway with dominant-negative mutant STAT3D effectively abolished IL-6-induced VEGF mRNA. In transient transfections, a luciferase reporter construct containing the full-length 1.5-kb VEGF promoter or a 1.2-kb fragment lacking the known hypoxic-response element also exhibited the same degree of response to IL-6. Additionally, transient transfection of STAT3D downregulated the 1.2-kb VEGF promoter luciferase reporter stimulated by IL-6. Based on the above phenomenon combined with the concomitant increased tumor expression of IL-6 and VEGF in cervical cancer tissues, we conclude that IL-6 may promote cervical tumorigenesis by activating VEGF-mediated angiogenesis via a STAT3 pathway.Oncogene (2003) 22, 1517-1527. doi:10.1038/sj.onc.1206226 [ABSTRACT FROM AUTHOR]

Tuberoside M ( 1 ), isolated from the seeds of Allium tuberosum , shows a significant inhibitory effect on the growth of the human promyelocytic leukemia cell line (HL-60) with IC 50 value of 6.8 μg/ml. On the basis of spectral data and chemical reaction, its structure was established as (25 S )-5β-spirostane-1β,3β-diol 3- O -α- l -rhamnopyranosyl-(1→4)-β- d -glucopyranoside. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the chronic toxicity of a mixture of chlorinated alkanes and alkenes (CA) consisting of chloroform, 1,1-dichloroethane, 1,1-dichloroethylene, 1,1,1-trichloroethane, trichloroethylene, and tetrachloroethylene. These chlorinated organic solvents were present in the underground water near an electronic appliances manufactory in Taoyuan, Taiwan. Male and female weanling ICR mice were treated with low-, medium-, and high-dose CA mixtures in drinking water for 16 and 18 mo, respectively. A significant number of male mice treated with the high-dose CA mixture developed tail alopecia and deformation, which was not prominent in CA-treated female mice. Medium- and high-dose CA mixtures induced marginal increases of liver and lung weights, blood urea nitrogen, and serum creatinine levels in male mice. In female mice, the high-dose CA mixture increased liver, kidney, and uterus and ovary total weights, without affecting serum biochemistry parameters. CA mixtures had no effects on the total glutathione content or the level of glutathione S-transferase activity in the livers and kid neys of male and female mice. Treatments with CA mixtures produced a trend of increasing frequency of hepatocelluar neoplasms in male mice, compared to male and female controls and CA-treated female mice. The high-dose CA mixture induced a significantly higher incidence of mammary adenocarcinoma in female mice. The calculated odds ratios of mammary adenocarcinoma in female mice induced by low-, medium-, and high-dose CA mixtures were 1.14, 1.37, and 3.53 times that of the controls, respectively. The low-dose CA mixture induced a higher incidence of cysts and inflammation in and around the ovaries. This study has demonstrated that the CA mixture is a potential carcinogen to male and female mice. These animal toxicology data may be important in assessing the health effects of individuals exposed to the CA mixture. [ABSTRACT FROM AUTHOR]

Interleukin-6 (IL-6), a multifunctional cytokine, has recently been implicated in human cervical cancer, though the mechanism remains elusive. This study demonstrates that the anti-apoptotic protein Mcl-1 and IL-6 was concomitantly expressed in human cervical cancer tissues and cell lines, but not in normal cervix tissues. Upon IL-6 treatment, Mcl-1, but not other Bcl-2 family members, was rapidly up-regulated peaking at 4–8 h in human cervical cancer C33A cells. Supporting this observation, using anti-IL-6 or anti-IL-6 receptor antibody to interrupt the IL-6 autocrine loop in SiHa cells significantly reduced cellular level of Mcl-1. This study hypothesizes that the expression of Mcl-1 in cervical cancer cells is regulated by IL-6. The matter of which signaling pathways transduced by IL-6 is responsible for the Mcl-1 up-regulation is further investigated herein. Blocking the STAT3 or MAPK pathway with dominant-negative mutant STAT3F or the MEK inhibitor PD98059 failed to inhibit IL-6-mediated Mcl-1 expression. Meanwhile, the IL-6-induced Mcl-1 up-regulation was effectively abolished by treatment with PI 3-K inhibitors, LY294002. Additionally, overexpression of dominant-negative (dn) Akt in C33A cells could inhibit the IL-6-induced increase of Mcl-1. Finally, overexpression of IL-6 in C33A cells caused a markable resistance to apoptosis induced by doxorubicin or cisplatin. Transient transfection of IL-6-overexpressed cells with a mcl-1 antisense vector, leading to the attenuation of their apoptosis-resistant activity. In conclusion, the data herein suggest that IL-6 regulated the mcl-1 expression via a PI 3-K/Akt-dependent pathway that may facilitate the oncogenesis of human cervical cancer by modulating the apoptosis threshold. Oncogene (2001) 20, 5799–5809. [ABSTRACT FROM AUTHOR]

Studies the blast-wave interaction problem using both inviscid- and viscous-flow models. Initial conditions considered; Sketch of an initial blast-wave interaction with a flat plate; Blast-wave propagation in a free field.

Interleukin-6 (IL-6) is a pleitrophic cytokine that not only regulates growth and differentiation of many cell types, but also induces production of acute phase proteins (AAP) in hepatocytes. Our previous works have demonstrated that both PI 3-K/Akt and STAT3 pathways were concomitantly activated and cooperatively mediated the anti-apoptotic effect of IL-6. This investigation reports that IL-6 protected cells against apoptosis induced by a variety of agents including, TGF-β, UV and retinoic acid (RA) in Hep3B cells, suggesting that IL-6 is a fundamental determinant of hepatic cell survival. Mcl-1, but not other Bcl-2 family members, was rapidly up-regulated by IL-6, with a peak (approximately 3–4-fold) appearing at 4 h. Transient transfection of cells with a mcl-1 antisense vector, resulting in a 50–60% reduction of the anti-apoptotic effect of IL-6, indicating that Mcl-1 is a downstream effector of IL-6. Which signaling pathway transduced by IL-6 responsible for the Mcl-1 up-regulation was further investigated. In Hep3B cells, the JAK/STAT3, ERK, and PI 3-K/Akt pathways were activated by IL-6 stimulation. Blocking JAK/STAT3 activation with a dominant-negative mutant STAT3F or a JAK inhibitor AG490 could not influence IL-6-mediated Mcl-1 up-regulation. Similarly, PD98059 treatment, a MEK specific inhibitor, also failed to inhibit Mcl-1 expression. However, the IL-6-induced Mcl-1 up-regulation was effectively attenuated in the presence of PI 3-K inhibitors, LY294002 and wortmannin. Expression of dominant-negative Akt, but not Etk, could abrogate the IL-6-induced increase of Mcl-1. In conclusion, our results suggest that the anti-apoptotic effect of IL-6 is mediated, at least in part, by Mcl-1 expression and that is mainly through the PI 3-K/ Akt-dependent pathway. Oncogene (2001) 20, 677–685. [ABSTRACT FROM AUTHOR]

The healing of diabetic foot ulcers (DFUs) stalled in inflammation stage due to overabundance of inflammatory macrophages and the dysregulated M1/M2 macrophages in the lesion. Restoring the balance of M1/M2 macrophages plays a critical role in orchestrating the healing process of DFUs. By recognizing the therapeutic potential in M1/M2-macrophage-regulation for DFUs, we aim to evaluate the efficacy and safety of ON101, a topical new drug with M1/M2-macrophage-regulating mechanism versus a hydrocolloid dressing in an international, multicenter, randomized, controlled, evaluator-blind phase 3 study in 21 clinical/medical centers across the US, China, and Taiwan by following Guidance for Industry Chronic Cutaneous Ulcer and Burn Wounds — Developing Products for Treatment. 236 eligible patients with post-debrided DFU(s) between 1 - 25 cm2, present for ≥4 weeks and Wagner Grade 1 or 2, were randomized 1:1 to receive ON101 or comparator for up to 16 weeks followed by a 12-week follow-up. Baseline demography and medical history between the two groups were well balanced. The incidence of complete healing as the primary endpoint in full analysis set was 60.7% by ON101 and 35.1% by the comparator during the treatment period (p=0.0001). Time to complete ulcer healing as the secondary endpoint was noted faster in the ON101 group (p=0.002). No significant changes or differences between the two treatment groups in hematology, biochemistry (including HbA1c and fasting glucose), or vital signs. Related treatment of emergent adverse events was reported in 7 patients (5.7%) in the ON101 group and 5 (4.4%) from the comparator group. None of the serious adverse events was related to ON101 while there was a case of osteomyelitis reported to be related to the comparator. ON101, recently approved by Taiwan Food and Drug Administration, was shown with clinically significant efficacy and well-tolerated safety profile in DFUs which provides not only a new prospect in DFU management but a differentiated approach towards active-healing. Disclosure: M. Kuo: Employee; Self; Oneness Biotech Co., Ltd. [ABSTRACT FROM AUTHOR]

A combinative iron(III) chloride/sodium iodide system was found to be very efficient for the iododemetallation of both organotrifluoroborates and tributyl(aryl)stannanes. A variety of functional groups tolerate the mild reaction conditions. [ABSTRACT FROM AUTHOR]

Background: Visual–perceptual defects in children can negatively affect their ability to perform activities of daily living. Conventional rehabilitation training for correcting visual–perceptual defects has limited training patterns and limited interactivity, which makes motivation difficult to sustain. Objective: We aimed to develop and evaluate an interactive digital game system for correcting visual–perceptual defects and evaluate its effectiveness. Methods: Participants were children aged 5 to 10 years with a diagnosis of visual–perceptual defect associated with a developmental disability. The children were randomized into a digital game group who received the traditional course of rehabilitation combined with an interactive digital game intervention (n=12) and a standard rehabilitation group (n=11) who only received the traditional course of rehabilitation. Each group underwent rehabilitation once a week for 4 weeks. Overall improvement in Test of Visual Perceptual Skills 3rd edition (TVPS-3) score and overall improvement in performance in the interactive digital game were evaluated. Parents and therapists were asked to complete a satisfaction questionnaire. Results: After 4 weeks, the TVPS-3 score had significantly increased (P=.002) in the digital game group (pre: mean 41.67, SD 13.88; post: 61.50, SD 21.64). In the standard rehabilitation group, the TVPS-3 score also increased, but the increase was not statistically significant (P=.58). Additionally, TVPS-3 score increases were significantly larger for the digital game group compared with those for the standard rehabilitation group (P=.005). Moreover, both parents and therapists were highly satisfied with the system. All 5 themes of satisfaction had mean scores higher than 4 in a 5-point scale questionnaire (mean 4.30, SD 0.56). Conclusions: The system has potential applications for improving visual–perceptual function in children undergoing medical rehabilitation for developmental disability [ABSTRACT FROM AUTHOR]

Poly (ADP-ribose) polymerase (PARP), a nuclear enzyme responsible for DNA strand breaks, has been recently suggested to be crucial for apoptosis induced by a number chemotherapeutic drugs. In this study, we demonstrated that the PARP activity could be evidently elevated with a peak at 6 h when HL-60 cells were treated with a new anticancer drug GL331. Coincident with the peak of PARP activity, an apparent DNA fragmentation and apoptotic morphology were observed in cells treated with GL331. The subsequent apoptotic DNA fragmentation induced by GL331 could be completely blocked by transfecting cells with anti-sense PARP retroviral vector or by treating cells with PARP inhibitor, 3-aminobenzamide (3-AB). This blocking effect thus suggests that activation of PARP was critically involved in GL331-induced apoptosis. The fact that Bcl-2 has been found to antagonize cell death induced by a wide variety of agents, accounts for why we examined whether if Bcl-2 could antagonize GL331 effects. Interestingly, ectopic overexpression of Bcl-2 in either HL-60 or U937 cells caused in resistance towards GL331-elicited DNA fragmentation and cytotoxic effect. Additionally, Bcl-2 also attenuated the poly(ADP-ribosyl)ation of PARP itself as well as Histone H1 at the early period of drug treatment. However, Bcl-2 did not influence the extent of DNA strand breaks induced by GL331 in either control or Bcl-2-overexpressing cells. In addition, analysis of basal PARP activity in control and several Bcl-2 overexpressing clones revealed that Bcl-2 down-regulated PARP activity under the condition without DNA damages. Above findings suggest that poly(ADP-ribosyl)ation of nuclear targets is important for apoptosis induced by DNA-reactive anticancer drugs. [ABSTRACT FROM AUTHOR]

Brain injury often caused irreversible loss of neural tissue and resulted in serious neurological disability. Owing to the extreme complexity of the brain, it is still challenging to regenerate the brain tissue from injury and restore its normal function. Growth factors are critical signaling molecules that promote endogenous neural stem/progenitor cells (NSPCs) proliferation, migration and differentiation, resulting in functional brain recovery from injury. However, the labile nature of growth factor motivated us to develop advanced growth factor delivery strategies to precisely control over its release profile in vivo. In this review, we will discuss growth factor delivery via biomaterials for brain regeneration after injury. This review begins with an overview of some major forms of brain injury. The characteristic properties of growth factors are described to provide a biological basis for their use in the brain regeneration. The specific biomaterials that generally used for delivering growth factor to treat brain injury are also detailed summarized. In particular, we focus on an engineering strategy that promote endogenous repair by creating growth factor concentration gradients in vivo. The last part of the review introduces current challenges and perspectives for growth factor delivery via biomaterials. [ABSTRACT FROM AUTHOR]

Abstract: Dialkynylboron chlorides couple smoothly with aryl aldehydes at room temperature to afford 1,4-dialkynes in good to excellent yields. Dialkynylboron halides act simultaneously as Lewis acid and reactant in this coupling reaction. [Copyright &y& Elsevier]

Abstract: In the presence of iron trichloride, the hydrolysis of potassium organotrifluoroborates occurs smoothly at room temperature to afford the corresponding organoboronic acids in good to excellent yields. The hydrolysis is effective for aryltrifluoroborates as well as alkenyl- and alkyl-trifluoroborates. [Copyright &y& Elsevier]

Abstract: New boron-based methods for deoxygenating benzylic alcohols via the corresponding alkoxides are reported. [Copyright &y& Elsevier]

Silicon nitride ceramics were prepared by spark plasma sintering (SPS) at temperatures of 1450°–1600°C for 3–12 min, using α-Si3N4 powders as raw materials and MgSiN2 as sintering additives. Almost full density of the sample was achieved after sintering at 1450°C for 6 min, while there was about 80 wt%α-Si3N4 phase left in the sintered material. α-Si3N4 was completely transformed to β-Si3N4 after sintering at 1500°C for 12 min. The thermal conductivity of sintered materials increased with increasing sintering temperature or holding time. Thermal conductivity of 100 W·(m·K)−1 was achieved after sintering at 1600°C for 12 min. The results imply that SPS is an effective and fast method to fabricate β-Si3N4 ceramics with high thermal conductivity when appropriate additives are used. [ABSTRACT FROM AUTHOR]

Alkoxide C−O bond cleavage occurs readily at room temperature in the presence of titanium(IV) halide. Capture of the resultant carbocation by alkynes provides an efficient route to trisubstituted (E)-alkenyl halides with high stereoselectivity. [ABSTRACT FROM AUTHOR]

An alternate reaction mechanism for the boron tribromide mediated deprotection of aryl propargyl ethers based on the isolation of a key boron-containing byproduct is proposed. On the basis of the new mechanistic insight, we discovered that HBBr2·SMe2 can also be used for cleaving aryl propargyl ethers. [ABSTRACT FROM AUTHOR]

The reaction of aryl aldehydes with allylsilanes in the presence of boron trihalides produces haloallylated products. Mechanistic details are presented. [ABSTRACT FROM AUTHOR]

Iron trichloride was found to cleave carbon−oxygen bonds in a variety of lithium alkoxides at room temperature. Other Lewis acids were also found to cleave the alkoxides. Acid-sensitive groups are tolerated under the reported reaction conditions. [ABSTRACT FROM AUTHOR]

Abstract: A novel boronated aminocyclobutanecarboxylic acid was synthesized in 10 steps for potential use in neutron capture therapy. The molecule was modeled after the unnatural amino acid 1-aminocyclobutanecarboxylic acid, which has shown high uptake in brain tumors. [Copyright &y& Elsevier]

An efficient synthesis of a dicyclobutylideneethane derivative was achieved using a palladium-catalyzed reaction of a substituted (bromomethylene)cyclobutane with bis(pinacolato)diboron. The reaction mechanism was investigated in detail. The Suzuki cross-coupling reaction of a (bromomethylene)cyclobutane with arylboronic acid was also achieved. [Copyright &y& Elsevier]

An efficient route to 3-(hydroxymethyl)cyclobutanone acetals via a [2+2] cycloaddition reaction is reported. The dramatic effect of different diol acetals on benzyl deprotection is discussed. Efficient synthesis of two synthetically useful intermediates, 3-methylenecyclobutanone acetal and 3-(bromomethyl)cyclobutanone, are provided. [Copyright &y& Elsevier]

Introduces a convenient approach to 4-substituted 2(5H)-furanones. Effects of solvent and base on the coupling of trans-pentylcyclopropylboronic acid with beta-tetronic acid triflate; Account on the coupling reaction of boronic acids with beta-tetronic acid triflate; Properties of compounds containing 2(5H)-furanone moiety.

Accurate analysis of targeted sentiment in online course reviews helps in understanding emotional changes of learners and improving the course quality. In this paper, we propose a fine-tuned bidirectional encoder representation from transformers (BERT) model for targeted sentiment analysis of course reviews. Specifically, it consists of two parts: binding corporate rules — conditional random field (BCR-CRF) target extraction model and a binding corporate rules — double attention (BCR-DA) target sentiment analysis model. Firstly, based on a large-scale Chinese review corpus, intra-domain unsupervised training of a BERT pre-trained model (BCR) is performed. Then, a Conditional Random Field (CRF) layer is introduced to add grammatical constraints to the output sequence of the semantic representation layer in the BCR model. Finally, a BCR-DA model containing double attention layers is constructed to express the sentiment polarity of the course review targets in a classified manner. Experiments are performed on Chinese online course review datasets of China MOOC. The experimental results show that the F1 score of the BCR-CRF model reaches above 92%, and the accuracy of the BCR-DA model reaches above 72%. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to demonstrate that the augmented reality computer-assisted spine surgery (ARCASS) system is clinically feasible for percutaneous vertebroplasty (PVP).Methods: This prospective case-control study included the patients undergoing PVP under the assistance of the ARCASS system between July 1, 2013, and October 31, 2014. The control group was the age- and gender-matched patients who underwent standard PVP and met the same eligible criteria as the case group. Primary outcome was the frequency of fluoroscopy. Secondary outcomes were the accuracy of bony entry point and operative time.Results: Eighteen patients were included in this study: 9 patients with 11 levels of lesions in the ARCASS group and 9 patients with 10 levels of lesions in the control group. Compared with the control group, the ARCASS group had significantly less frequency of fluoroscopy (6 vs. 18, P < 0.001) and shorter operative time (78 vs. 205 s, P < 0.001) during the process of entry point identification and local anesthesia, which started from the registration of skin entry point at lesion site to the end of bony entry point identification. Regarding accuracy, the ARCASS group had significant greater proportion of 'good' entry point than the control group on lateral views (81.8% vs. 30.0%, P = 0.028) and anteroposterior views (72.7% vs. 20.0%, P = 0.020).Conclusion: This study revealed that the ARCASS system was clinically feasible for PVP. The guidance of ARCASS system provided more accurate bony entry point with reduced operative time and unnecessary radiation exposure. [ABSTRACT FROM AUTHOR]

We describe high-level ab initio calculations on the BH2, HBF, HBCl and HBBr radicals. Molecular structure, vibrational frequencies and potential energy curves of the ground state and the first excited state, which are two Renner–Teller components for a2Π state at linearity, are studied using the basis sets aug-cc-pVTZ and icMRCI+Q technique. On the basis of the potential energy curves, a reliable potential energy barrier to dissociation HB+X (X=F, Cl, Br) fragments and to linearity are given. The ab initio results will add some understanding on the spectrum and the photo-dissociation dynamics of the series of radicals. [ABSTRACT FROM AUTHOR]

The article reports that alcoholic liver disease (ALD), induced by long-term heavy alcohol consumption, encompasses a progressive clinical-histological spectrum of liver injuries from simple fatty liver to alcoholic hepatitis, hepatic fibrosis and cirrhosis. It notes that hepatitis virus infection exerts a synergistic effect on alcohol-induced liver injury. It adds that ALD could both accelerate the development and progression of liver diseases.