Clinicopathologic risk factors for distant metastases from head and neck squamous cell carcinomas

AIMS

The aim of this study is to investigate the clinicopathologic risk factors associated with distant metastases (DMs) from head and neck squamous cell carcinomas (HNSCCs).

METHODS

Between February 1990 and February 2000, a retrospective analysis of 391 HNSCC patients was performed. The frequency and the clinicopathologic risk factors for DM were evaluated by using univariate chi(2) tests and multiple stepwise logistic regression models. Statistical analysis of overall survival was performed by using Kaplan-Meier method.

RESULTS

44 patients (11.3%) developed DM in clinic. In a univariate analysis, clinical N stage, primary tumor site, level of tumor invasion, pathologic N stage and number of levels with pathologic lymph node were found to be significantly associated with the risk of DM. In a multivariate analysis, the most significant risk factors were number of levels with pathologic lymph node, level of tumor invasion, and primary tumor site. Kaplan-Meier analysis showed that overall survival rates of 44 patients with DMs in clinic were 56.8% at 1 year, 9.1% at 3 years, and 6.8% at 5 years, respectively.

CONCLUSIONS

The number of levels with pathologic lymph node, the site of primary tumor and the level of tumor invasion are decisive risk factors in determining the development of DM in head and neck SCC patients. Patients with multilevel nodal involvement in neck, with laryngeal and hypopharyngeal carcinomas, and patients with primary tumor invasion into muscular, bone or cartilage have the highest risk of developing DM.

Increased expression of erythropoietin receptor in 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine-induced Parkinsonian model

Erythropoietin (EPO), known for its role in erythroid differentiation, has been suggested to have a direct protective role against a variety of neurotoxic insults. In the present study, we investigated the expression of EPO receptor (EPOR) and the number of EPOR-positive cells in three encephalic regions (ventral mesencephalon, striatum, cortex) following lesion induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). C57BL/6 mice underwent intraperitoneal injection of MPTP at 24 h intervals for 5 days, and their brains were examined 1, 2, 4, 7, 14 or 21 days after the last injection. Western blot and immunohistochemistry analysis revealed that EPOR was dramatically up-regulated in the ventral mesencephalon, 4 days after MPTP insult until the day 21. In contrast, there was a baseline level of EPOR in the striatum and cortex. At subsequent time points after MPTP injury, the levels of EPOR in the two regions were not statistically different compared with those in normal animals. These results suggest that the regional specific up-regulation of EPOR at an early stage after MPTP stimulus may represent a pro-survival mechanism against neurotoxin injury in Parkinsonian model.

Adaptive response in embryogenesis: vi. Comparative microarray analysis of gene expressions in mouse fetuses

PURPOSE

Exposure of sublethal doses of ionizing radiation can induce protective mechanisms against a subsequent higher dose irradiation. This phenomenon, called radiation-induced adaptive response (AR), has been described in a wide range of biological models. We previously demonstrated the existence of AR in mice during late organogenesis. In this study, we investigated molecular mechanisms underlying AR in this model.

MATERIALS AND METHODS

Using DNA microarrays, we performed a global analysis of transcriptome regulations in adapted and non-adapted cells collected from whole mouse fetuses, after in utero exposure to priming irradiation.

RESULTS

We identified AR-specific gene modulations. Our results suggested the involvement of signal transduction and Tumor protein (p53)-related pathways in the induction of AR.

CONCLUSIONS

Our results are in agreement with previous investigations showing that AR could be dependant on p53 activity. The observed gene modulations may also have possible consequences for subsequent developmental process of the fetus. This is the first report of AR-specific modulations at the molecular level in utero, which could serve as a basis for subsequent studies aimed at understanding AR in this model and possible long-term effects.

Differential regulation of collagen types I and III expression in cardiac fibroblasts by AGEs through TRB3/MAPK signaling pathway

Advanced glycation end products (AGEs) play an important role in collagen deposition in diabetic cardiomyopathy. TRB3, a mammalian homolog of Drosophila tribbles, functions to increase glucose intolerance and regulates cell proliferation. We demonstrated that AGEs induce collagen type I expression but inhibit collagen type III expression, accompanied by increased TRB3 expression. Furthermore, the collagen type I induced byAGEs was down-regulated after inhibition of ERK and p38-MAPK, the collagen type III reduced by AGEs was up-regulated after inhibition of ERK. The expression of collagen types I and III regulated by AGEs through MAPK was partly reversed after treatment with TRB3 siRNA. It suggests that the TRB3/MAPK signaling pathway participates in the regulation of collagen types I and III by AGEs and may provide new therapeutic strategies for diabetic cardiomyopathy.

The effects of the spatial influence function on orthotropic femur remodelling

The morphology and internal structure of bone are modulated by the mechanical stimulus. The osteocytes can sense the stimulus signals from the adjacent regions and respond to them through bone growth or bone absorption. This mechanism can be modelled as the spatial influence function (SIF) in bone adaptation algorithm. In this paper, the remodelling process was simulated in human femurs using an adaptation algorithm with and without SIF, and the trabecular bone was assumed to be orthotropic. A different influence radius and weighting factor were adopted to study the effects of the SIF on the bone density distribution and trabecular alignment. The results have shown that the mean density and L—T ratio (the ratio of longitudinal modulus to transverse modulus) had an excellent linear relationship with the weighting factor when the influence radius was small. The characteristics of density distribution and L—T ratio accorded with the actual observation or measurement when a small weighting factor was used. The large influence radius and weighting factor led to unrealistic results. In contrast, the SIF hardly affected the trabecular alignment, as the mean variation angles of principal axes were less than 1.0 degree for any influence radius and weighting factor

CHIP promotes Runx2 degradation and negatively regulates osteoblast differentiation

Runx2, an essential transactivator for osteoblast differentiation, is tightly regulated at both the transcriptional and posttranslational levels. In this paper, we report that CHIP (C terminus of Hsc70-interacting protein)/STUB1 regulates Runx2 protein stability via a ubiquitination-degradation mechanism. CHIP interacts with Runx2 in vitro and in vivo. In the presence of increased Runx2 protein levels, CHIP expression decreases, whereas the expression of other E3 ligases involved in Runx2 degradation, such as Smurf1 or WWP1, remains constant or increases during osteoblast differentiation. Depletion of CHIP results in the stabilization of Runx2, enhances Runx2-mediated transcriptional activation, and promotes osteoblast differentiation in primary calvarial cells. In contrast, CHIP overexpression in preosteoblasts causes Runx2 degradation, inhibits osteoblast differentiation, and instead enhances adipogenesis. Our data suggest that negative regulation of the Runx2 protein by CHIP is critical in the commitment of precursor cells to differentiate into the osteoblast lineage.

[A method to evaluate femoral bone mass in rats with CT numbers]

To develop a method of evaluating bone mass with CT numbers (Hounsfield unit, HU), volumetric mean of CT numbers (HUm) was defined to describe bone mass for the study of bone loss caused by microgravity. Ten femurs in the tail-suspended rats experiment were scanned by CT scanner. And the RUm of the intact, proximal, middle and distal femurs were obtained from these CT data. Then regressive analysis was performed between HUm and bone mineral density (BMD) measured by DXA in those regions. When HU threshold is equal to 400, the correlation between BMD and HUm of the intact femur is the best in all cases (R = 0.887, P <0.001), and the correlation between BMD and HUm of the proximal femur (R = 0.833, P <0.01) is better than those of the middle femur (R=0.683, P<0.05) and distal femur (R = 0.744, P<0.05). Volumetric mean of CT numbers has a good linear relationship with BMD; it can accurately describe bone mass and can be used to evaluate the results of the tail-suspended rats experiment.

Intense beam production of highly charged heavy ions by the superconducting electron cyclotron resonance ion source SECRAL

There has been increasing demand to provide higher beam intensity and high enough beam energy for heavy ion accelerator and some other applications, which has driven electron cyclotron resonance (ECR) ion source to produce higher charge state ions with higher beam intensity. One of development trends for highly charged ECR ion source is to build new generation ECR sources by utilization of superconducting magnet technology. SECRAL (superconducting ECR ion source with advanced design in Lanzhou) was successfully built to produce intense beams of highly charged ion for Heavy Ion Research Facility in Lanzhou (HIRFL). The ion source has been optimized to be operated at 28 GHz for its maximum performance. The superconducting magnet confinement configuration of the ion source consists of three axial solenoid coils and six sextupole coils with a cold iron structure as field booster and clamping. An innovative design of SECRAL is that the three axial solenoid coils are located inside of the sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. For 28 GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6 T at injection, 2.2 T at extraction, and a radial sextupole field of 2.0 T at plasma chamber wall. During the commissioning phase at 18 GHz with a stainless steel chamber, tests with various gases and some metals have been conducted with microwave power less than 3.5 kW by two 18 GHz rf generators. It demonstrates the performance is very promising. Some record ion beam intensities have been produced, for instance, 810 e microA of O(7+), 505 e microA of Xe(20+), 306 e microA of Xe(27+), and so on. The effect of the magnetic field configuration on the ion source performance has been studied experimentally. SECRAL has been put into operation to provide highly charged ion beams for HIRFL facility since May 2007.

Experimental study of hot electrons in LECR2M plasma

In order to investigate the hot electron component in electron cyclotron resonance (ECR) plasmas, the volume bremsstrahlung spectra in the x-ray photon energy range were measured with a high-purity germanium detector on Lanzhou ECR Ion Source No. 2 Modified (LECR2M). A collimation system similar to Bernhardi's was used to focus at the central part of the plasma. The ion source was operated under various source conditions with argon; sometimes oxygen was added to enhance high charge state ion beam intensities. The spectral temperature of hot electrons T(spe) was derived from the measured bremsstrahlung spectra. The evolution of the deduced temperature of hot electrons T(spe) with the ion source parameters, such as the rf frequency, power, and the magnetic confinement configuration, was investigated.

An electron cyclotron resonance ion source based low energy ion beam platform

To satisfy the requirements of surface and atomic physics study in the field of low energy multiple charge state ion incident experiments, a low energy (10 eV/q-20 keV/q) ion beam platform is under design at IMP. A simple test bench has been set up to test the ion beam deceleration systems. Considering virtues such as structure simplicity, easy handling, compactness, cost saving, etc., an all-permanent magnet ECRIS LAPECR1 [Lanzhou all-permanent magnet electron cyclotron resonance (ECR) ion source No. 1] working at 14.5 GHz has been adopted to produce intense medium and low charge state ion beams. LAPECR1 source has already been ignited. Some intense low charge state ion beams have been produced on it, but the first test also reveals that many problems are existing on the ion beam transmission line. The ion beam transmission mismatches result in the depressed performance of LAPECR1, which will be discussed in this paper. To obtain ultralow energy ion beam, after being analyzed by a double-focusing analyzer magnet, the selected ion beam will be further decelerated by two afocal deceleration lens systems, which is still under design. This design has taken into consideration both ions slowing down and also ion beam focusing. In this paper, the conceptual design of deceleration system will be discussed.

36-segmented high magnetic field hexapole magnets for electron cyclotron resonance ion source

Two high magnetic field hexapoles for electron cyclotron resonance ion source (ECRIS) have successfully fabricated to provide sufficient radial magnetic confinement to the ECR plasma. The highest magnetic field at the inner pole tip of one of the magnets exceeds 1.5 T, with the inner diameter (i.d.)=74 mm. The other hexapole magnet provides more than 1.35 T magnetic field at the inner pole tip, and the i.d. is 84 mm. In this article, we discuss the necessity to have a good radial magnetic field confinement and the importance of a Halbach hexapole to a high performance ECRIS. The way to design a high magnetic field Halbach structure hexapole and one possible solution to the self-demagnetization problem are both discussed. Based on the above discussions, two high magnetic field hexapoles have been fabricated to be utilized on two high performance ECRISs in Lanzhou. The preliminary results obtained from the two ECR ion sources are given.

Transcriptional feedback and definition of the circadian pacemaker in Drosophila and animals

The modern era of Drosophila circadian rhythms began with the landmark Benzer and Konopka paper and its definition of the period gene. The recombinant DNA revolution then led to the cloning and sequencing of this gene. This work did not result in a coherent view of circadian rhythm biochemistry, but experiments eventually gave rise to a transcription-centric view of circadian rhythm generation. Although these circadian transcription-translation feedback loops are still important, their contribution to core timekeeping is under challenge. Indeed, kinases and posttranslational regulation may be more important, based in part on recent in vitro work from cyanobacteria. In addition, kinase mutants or suspected kinase substrate mutants have unusually large period effects in Drosophila. This chapter discusses our recent experiments, which indicate that circadian transcription does indeed contribute to period determination in this system. We propose that cyanobacteria and animal clocks reflect two independent origins of circadian rhythms.

Differential effects of drug-induced ascorbic acid release in the striatum and nucleus accumbens of freely moving rats

Previous studies have shown that striatum and nucleus accumbens (NAc) are two different structures in mediating addictive drug-induced ascorbic acid (AA) release. In order to further characterize the different effects of drugs-induced AA release in the striatum and NAc, in the present study, we investigated the effect of ethanol, morphine, methamphetamine, nicotine-induced AA release in these two nuclei using microdialysis coupled to high performance liquid chromatography with electrochemical detection (HPLC-ECD). All drugs were continuously perfused directly into the striatum or NAc. This study showed that local intrastriatal or intra-accumbensal perfusion of ethanol (500 microM) could increase AA release to 280, 260% in the striatum and NAc, respectively. Intra-striatal infusion of morphine (1 mM), methamphetamine (250 microM) or nicotine (500 microM), reduce striatal AA release to 48, 50, 45%, respectively. While given intra-accumbensally, morphine (1 mM), methamphetamine (250 microM) or nicotine (500 microM) increase AA release to 165, 160, 160%, respectively. These results suggested that different presynaptic or postsynaptic mechanisms might be involved in addictive drug-induced AA release in the striatum and NAc.

Applications and limitations of ADM 1 in municipal wastewater solids treatment

The ADM 1 model has been implemented in a steady-state whole wastewater plant simulator. The ADM 1 model has been in use with good success for approximately 2 years on a wide range of wastewater treatment facilities. However, a number of modifications were necessary to allow it to be used in the context of municipal wastewater treatment. It was found that the model's use was greatly simplified if used in conjunction with a larger plant simulator to assist in the feed fractionation. It was also found that a better fit to actual operating data was achieved if some of the slowly biodegradable particulate fraction was partitioned into ADM particulate fractions other than the composite fraction. Another significant limitation of the model is in the absence of phosphorus modeling. The ADM model needs to have phosphorus handling for all the relevant fractions, and needs to include the handling of inorganic reactions such as struvite precipitation and metal phosphate/metal hydroxide precipitation. Activity effects on chemical equilibria are significant when considering phosphorus. Also of importance in wastewater treatment is the fate of sulfur compounds. This includes the generation of H2S in the digester gas and the fate of the sulfur species in the digested sludge (as a predictor of odour-generating potential).

Decreased expression of peroxisome proliferator-activated receptor γ in endotoxin-induced acute lung injury

Peroxisome proliferator-activated receptor-gamma (PPAR- gamma), a member of the nuclear hormone receptor superfamily of ligand-activated transcription factors, possesses anti-inflammatory properties. The purpose of the present study was to investigate the profile of PPAR-gamma expression in the lung and to explore its functional significance in lipopolysaccharide (LPS)-induced acute lung injury. Thirty male Wistar rats were randomly assigned to one of the following five groups: saline control group and different LPS groups (2 h, 4 h, 6 h and 8 h after LPS 6 mg/kg i.v.). At predefined time points, blood samples were collected to measure plasma level of tumor necrosis factor (TNF)-alpha and lungs were removed to assay histopathological changes, wet-to-dry weight (W/D) ratio, myeloperoxidase (MPO) activity and TNF-alpha level. Expression of PPAR-gamma and activation of nuclear factor (NF)-kapaB p65 in lung tissues were also examined in each group. LPS injection resulted in marked lung damage and elevated levels of W/D ratio and MPO activity in the lung. Increased levels of TNF-alpha were also observed in the plasma and lung. These inflammatory events were associated with reduced expression of PPAR-gamma protein and with activation of NF-kapaB in the lung. Our data suggest that decreased expression of PPAR-gamma protein in lungs may contribute to the ongoing pulmonary inflammation and tissue injury in endotoxemia.

Decreased expression of peroxisome proliferator-activated receptor gamma in endotoxin-induced acute lung injury

Peroxisome proliferator-activated receptor-gamma (PPAR- gamma), a member of the nuclear hormone receptor superfamily of ligand-activated transcription factors, possesses anti-inflammatory properties. The purpose of the present study was to investigate the profile of PPAR-gamma expression in the lung and to explore its functional significance in lipopolysaccharide (LPS)-induced acute lung injury. Thirty male Wistar rats were randomly assigned to one of the following five groups: saline control group and different LPS groups (2 h, 4 h, 6 h and 8 h after LPS 6 mg/kg i.v.). At predefined time points, blood samples were collected to measure plasma level of tumor necrosis factor (TNF)-alpha and lungs were removed to assay histopathological changes, wet-to-dry weight (W/D) ratio, myeloperoxidase (MPO) activity and TNF-alpha level. Expression of PPAR-gamma and activation of nuclear factor (NF)-kapaB p65 in lung tissues were also examined in each group. LPS injection resulted in marked lung damage and elevated levels of W/D ratio and MPO activity in the lung. Increased levels of TNF-alpha were also observed in the plasma and lung. These inflammatory events were associated with reduced expression of PPAR-gamma protein and with activation of NF-kapaB in the lung. Our data suggest that decreased expression of PPAR-gamma protein in lungs may contribute to the ongoing pulmonary inflammation and tissue injury in endotoxemia.

CHIP Controls the Sensitivity of Transforming Growth Factor-β Signaling by Modulating the Basal Level of Smad3 through Ubiquitin-mediated Degradation

Transforming growth factor-beta (TGF-beta) signaling is critical in a variety of biological processes such as cell proliferation, differentiation, and apoptosis. TGF-beta signaling is mediated by a group of proteins including TGF-beta receptors and Smads. It is known that different cells can exhibit different sensitivities to TGF-beta. Several molecular mechanisms, such as the differential expression of the receptor levels, have been suggested as contributing to these differences. Here, we report evidence for a novel mechanism of regulating TGF-beta sensitivity that depends on the role of CHIP (carboxyl terminus of Hsc70-interacting protein) in regulating the basal level of Smad3 via the ubiquitin-dependent degradation pathway. First, using a luciferase assay we found that overexpression of CHIP inhibited TGF-beta signaling, whereas silencing CHIP expression by small interfering RNAs led to increased TGF-beta signaling sensitivity. Second, based on the results of cell proliferation assays and JunB expression, we found that TGF-beta signaling could be abolished by stably overexpressing CHIP. Third, in those cell lines with stably expressed CHIP, we observed that the Smad3 protein level was dramatically decreased. Finally, we demonstrated that CHIP served as a U-box dependent E3 ligase that can directly mediate ubiquitination and degradation of Smad3 and that this action of CHIP was independent of TGF-beta signaling. Taken together, these findings suggest that CHIP can modulate the sensitivity of the TGF-beta signaling by controlling the basal level of Smad3 through ubiquitin-mediated degradation.