Nickel Induces Pyroptosis via the Nrf2/NLRP3 Pathway in Kidney of Mice

Nickel (Ni) is considered a toxic metal, and excessive exposure can cause kidney damage. This study was designed to explore whether nickel chloride (NiCl2) can induce cell pyroptosis and its possible mechanism. Here, we found that NiCl2 treatment could reduce the kidney index and result in kidney damage. Meanwhile, NiCl2 could obviously induce renal pyroptosis, which was characterized by an increase in IL-18, IL-1β, NLRP3, and GSDMD expression. Furthermore, NiCl2 induced pyroptosis through the Nrf2/NLRP3 pathway which featured down-regulated protein and mRNA expression levels of Nrf2 and up-regulated protein and mRNA expression levels of Caspase-1, NLRP3, and GSDMD. In summary, excessive Ni exposure can induce renal cell pyroptosis, ultimately leading to kidney tissue damage and hindering normal development, and its possible mechanism may be due to the inhibition of the Nrf2 pathway.

A high-density and high-confinement tokamak plasma regime for fusion energy

The tokamak approach, utilizing a toroidal magnetic field configuration to confine a hot plasma, is one of the most promising designs for developing reactors that can exploit nuclear fusion to generate electrical energy1,2. To reach the goal of an economical reactor, most tokamak reactor designs3-10 simultaneously require reaching a plasma line-averaged density above an empirical limit-the so-called Greenwald density11-and attaining an energy confinement quality better than the standard high-confinement mode12,13. However, such an operating regime has never been verified in experiments. In addition, a long-standing challenge in the high-confinement mode has been the compatibility between a high-performance core and avoiding large, transient edge perturbations that can cause very high heat loads on the plasma-facing-components in tokamaks. Here we report the demonstration of stable tokamak plasmas with a line-averaged density approximately 20% above the Greenwald density and an energy confinement quality of approximately 50% better than the standard high-confinement mode, which was realized by taking advantage of the enhanced suppression of turbulent transport granted by high density-gradients in the high-poloidal-beta scenario14,15. Furthermore, our experimental results show an integration of very low edge transient perturbations with the high normalized density and confinement core. The operating regime we report supports some critical requirements in many fusion reactor designs all over the world and opens a potential avenue to an operating point for producing economically attractive fusion energy.

Experimental Validation of a Kinetic Ballooning Mode in High-Performance High-Bootstrap Current Fraction Fusion Plasmas

We report the observation of a set of coherent high frequency electromagnetic fluctuations that leads to a turbulence induced self-regulating phenomenon in the DIII-D high bootstrap current fraction plasma. The fluctuations have frequency of 130-220  kHz, the poloidal wavelength and phase velocity are 16-30  m^{-1} and ∼30  km/s, respectively, in the outboard midplane with the estimated toroidal mode number n∼5-9. The fluctuations are located in the internal transport barrier (ITB) region at large radius and are experimentally validated to be kinetic ballooning modes (KBM). Quasilinear estimation predicts the KBM to be able to drive experimental particle flux and non-negligible thermal flux, suggesting its significant role in regulating the ITB saturation.

Yiguanjian decoction inhibits macrophage M1 polarization and attenuates hepatic fibrosis induced by CCl4/2-AAF

CONTEXT

Our previous studies indicated that Yiguanjian decoction (YGJ) has an anti-hepatic-fibrosis effect and could regulate macrophage status.

OBJECTIVE

To elucidate the mechanism of YGJ in regulating macrophages.

MATERIALS AND METHODS

Liver cirrhosis was induced by CCl₄ for 12 weeks combined with 2-acetylaminofluorene (2-AAF) for the last 4 weeks in male Wistar rats. YGJ (3.56 mg/kg) orally administered in the last 4 weeks, and SORA (1 mg/kg) as control. In vitro, RAW264.7 cells were treated with lipopolysaccharides (LPSs) to induce macrophage polarization to the M1 phenotype, and they were co-cultured with WB-F344 cells and allocated to M group, YGJ group (2 μg/mL) and WIF-1 group (1 μg/mL) with untreated cells as control. The differentiation direction of WB-F344 cell line was observed in the presence or absence of YGJ. Pathology, fibrosis-related cytokines, macrophage polarization-related components, and Wnt signalling pathway components were detected.

RESULTS

In vivo, the expression levels of α-SMA, Col (1), OV6, SOX9, EpCAM and M1 macrophage-related components (STAT1, IRF3, IRF5, IRF8, SOCS3) significantly decreased in the YGJ group compared with those in the 2-AAF/CCl₄ group (p < 0.01 or 0.05). In vitro, the expression levels of M1 macrophage-related components, including STAT1, NF-κB, IRF3, IRF5, and SOCS3, in RAW264.7 cells decreased significantly in the YGJ group compared with those in the M group (p < 0.05 or p < 0.01). The expression levels of Wnt3A, FZD5, LRP-5/-6, and β-catenin significantly increased in the YGJ group compared with those in the M group (p < 0.05 or p < 0.01). In addition, the expression levels of Wnt-4/-5A/-5B, and FZD2 significantly decreased in the YGJ group compared with those in the M group (p < 0.05 or p < 0.01).

CONCLUSION

This study suggests that the anti-cirrhosis effect of YGJ is associated with its ability to inhibit macrophage M1-polarization, which provides a scientific basis for the clinical application of YGJ.

Multiscale Chirping Modes Driven by Thermal Ions in a Plasma with Reactor-Relevant Ion Temperature

A thermal ion driven bursting instability with rapid frequency chirping, considered as an Alfvénic ion temperature gradient mode, has been observed in plasmas having reactor-relevant temperature in the DIII-D tokamak. The modes are excited over a wide spatial range from macroscopic device size to microturbulence size and the perturbation energy propagates across multiple spatial scales. The radial mode structure is able to expand from local to global in ∼0.1  ms and it causes magnetic topology changes in the plasma edge, which can lead to a minor disruption event. Since the mode is typically observed in the high ion temperature ≳10  keV and high-β plasma regime, the manifestation of the mode in future reactors should be studied with development of mitigation strategies, if needed. This is the first observation of destabilization of the Alfvén continuum caused by the compressibility of ions with reactor-relevant ion temperature.

LncRNA ROR1-AS1 promotes colon cancer cell proliferation by suppressing the expression of DUSP5/CDKN1A

OBJECTIVE

The purpose of this study was to explore the possible role of ROR1-AS1 in the pathogenesis of colon cancer and the underlying mechanism.

PATIENTS AND METHODS

The expression levels of ROR1-AS1 in 75 colon cancer tissue samples and adjacent ones, as well as in cell lines were examined by quantitative Polymerase Chain Reaction (qPCR). Then, ROR1-AS1 overexpression plasmid and siRNA were transfected into colon cancer cells using liposome method. After that, Cell Counting Kit-8 (CCK-8) and plate colony formation assays were conducted to analyze cell proliferation, while flow cytometry was applied for the analysis of cell cycle and apoptosis. At last, the mechanism of action of ROR1-AS1 was further explored by nuclear separation, RNA binding protein immunoprecipitation (RIP) and chromatin immunoprecipitation (CHIP) assays.

RESULTS

ROR1-AS1 level in colon cancer tissues was remarkably higher than that in normal tissues, and the expression in tumors of stage III and IV was remarkably higher than those of stage I and II. Meanwhile, tumors with diameters more than 5 cm had a higher ROR1-AS1 expression than those less than 5 cm. After transfection with ROR1-AS1 overexpression plasmid, the cell proliferation ability was enhanced, the G0/G1 phase time of cell cycle was shortened, and the apoptosis was suppressed. However, the opposite result was observed after ROR1-AS1 was downregulated. Furthermore, RIP showed that ROR1-AS1 can bind to enhancer of zeste homolog 2 (EZH2) and inhibit the expression of DUSP5, and thus be engaged in the proliferation and apoptosis of colon cancer cells.

CONCLUSIONS

ROR1-AS1 is highly expressed either in colon cancer tissues or in cell lines, which is able to enhance cell proliferation, accelerate cell cycle, and inhibit cell apoptosis. The mechanism of ROR1-AS1 to participate in the development of colon cancer may be the downregulation of DUSP5 via combination with EZH2.

Isolation and characterization of ergosterol from Monascus anka for anti-lipid peroxidation properties

Unbalanced lipid peroxidation damages the human body, and is associated with the formation of tumors, infections, inflammations, autoimmune diseases, and cardiovascular and cerebrovascular diseases. However, food and drugs that contain anti-lipid peroxidation active substances, can help to protect against these negative health impacts. We observed lipid peroxidation inhibition in the metabolites of fermented Monascus anka, in media with Dendrobium nobile Lindl. The anti-lipid peroxidation ability of the extracts was strongest in ethyl acetate, so this was selected for further purifications. A crystal with strong antioxidant properties was obtained by column chromatography. Based on its spectroscopic analysis by Electron Bombardment Ion Source and Mass Spectrometry (EI-MS), ¹H-Nuclear Magnetic Resonance (¹H-NMR), and ¹³C-Nuclear Magnetic Resonance (¹³C-NMR), the isolated crystal was identified as ergosterol. The inhibition rates of the lipid peroxide due to the ergosterol were 57.42%, at 2μg/mL in vitro. Simultaneously, the survival rates of the damaged cells treated with 0.3mmol/L H₂O₂ were significantly improved with the ergosterol, up to 43.88% (200μg/mL) and 46.64% (400μg/mL), compared to 36.47% for the injured cells. The survival rate of the cells was 78.32% (400μg/mL), with ergosterol as a prevention. Cell injury can increase the level of intracellular ROS, but its levels in the damaged cells were reduced after the ergosterol treatments, and the reduction increased with the increasing concentrations. A 400μg/mL concentration resulted in the lowest fluorescence intensity; 33421.11 AU below the normal level. Ergosterol significantly reduced the ROS levels, to reduce the cell damage. Ergosterol from Monascus anka was thus found to have strong anti-lipid peroxidation and antioxidant capabilities, and the ability to protect and repair damaged cells. It may consequently serve as a potential natural antioxidant and will play an important role in human anti-lipid peroxide.

Hepatic stem cell Numb gene is a potential target of Huang Qi Decoction against cholestatic liver fibrosis

Numb is a negative regulator of Notch signal pathway. Previous study has demonstrated that Notch signal pathway activation is required for hepatic progenitor cell (HPC) differentiating into cholangiocytes in cholestatic liver fibrosis (CLF), and Huang Qi Decoction (HQD) could prevent CLF through inhibition of the Notch signal pathway. However, the role of Numb in HQD against CLF is yet unclear. Thus, CLF rats transplanted into rat bone marrow-derived mesenchymal stem cells with knocked down Numb gene (BMSC^Numb-KD) were treated with HQD. Simultaneously, Numb gene knockdown was also performed in WB-F344 cell line and then treated with refined HQD in vitro. In vivo study revealed that liver fibrosis was inhibited by HQD plus BMSC^Numb-KD treatment, while Hyp content in liver tissue, the gene and protein expression of α-SMA, gene expression of Col I, TNF-α, and TGF-β1 were increased compared to that in HQD group. Furthermore, Notch signal pathway was inhibited by HQD plus BMSC^Numb-KD, while the protein expression of Numb was decreased and RBP-Jκ and Hes1 was increased compared to that in HQD group. In vitro, HQD reduced the differentiation of WB-F344 cells into cholangiocyte phenotype, while this effect was attenuated after Numb-knockdown. This study highlights that the absence of hepatic stem cell Numb gene decreases effect of HQD against CLF, which give rise the conclusion that Numb might be a potential target for HQD against CLF.

LINC01605 promotes the proliferation of laryngeal squamous cell carcinoma through targeting miR-493-3p

OBJECTIVE

The purpose of this study was to elucidate the potential influence of LINC01605 on the progression of laryngeal squamous cell carcinoma (LSCC) and the underlying mechanism.

PATIENTS AND METHODS

LINC01605 and microRNA-493-3p (miR-493-3p) levels in normal laryngeal tissues, LSCC tissues, and paired paracancerous tissues were detected. Regulatory effects of LINC01605 on proliferative ability and apoptosis in HEp-2 and AMC-HN-8 cells were assessed. Besides, the interaction between LINC01605 and miR-493-3p was evaluated by Dual-Luciferase reporter gene assay and Spearman's rank correlation analysis. Finally, rescue experiments were conducted to clarify the role of LINC01605/miR-493-3p axis in the progression of LSCC.

RESULTS

LINC01605 was upregulated and miR-493-3p was downregulated in LSCC tissues. Knockdown of LINC01605 inhibited proliferative ability, and stimulated apoptosis in HEp-2 and AMC-HN-8 cells. Moreover, LINC01605 directly bound to miR-493-3p, and the former negatively regulated the level of the latter. In addition, miR-493-3p was able to reverse the regulatory effect of LINC01605 on proliferative ability in LSCC.

CONCLUSIONS

LINC01605 is upregulated in LSCC tissues, and it promotes the malignant progression of LSCC via targeting miR-493-3p.

Role of Microtearing Turbulence in DIII-D High Bootstrap Current Fraction Plasmas

We report on the first direct comparisons of microtearing turbulence simulations to experimental measurements in a representative high bootstrap current fraction (f_{BS}) plasma. Previous studies of high f_{BS} plasmas carried out in DIII-D with large radius internal transport barriers (ITBs) have found that, while the ion energy transport is accurately reproduced by neoclassical theory, the electron transport remains anomalous and not well described by existing quasilinear transport models. A key feature of these plasmas is the large value of the normalized pressure gradient, which is shown to completely stabilize conventional drift-wave and kinetic ballooning mode instabilities in the ITB, but destabilizes the microtearing mode. Nonlinear gyrokinetic simulations of the ITB region performed with the cgyro code demonstrate that the microtearing modes are robustly unstable and capable of driving electron energy transport levels comparable to experimental levels for input parameters consistent with the experimental measurements. These simulations uniformly predict that the microtearing mode fluctuation and flux spectra extend to significantly shorter wavelengths than the range of linear instability, representing significantly different nonlinear dynamics and saturation mechanisms than conventional drift-wave turbulence, which is also consistent with the fundamental tearing nature of the instability. The predicted transport levels are found to be most sensitive to the magnetic shear, rather than the temperature gradients more typically identified as driving turbulent plasma transport.

Breast cancer Ki67 expression prediction by DCE-MRI radiomics features

AIM

To investigate whether quantitative radiomics features extracted from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) are associated with Ki67 expression of breast cancer.

MATERIALS AND METHODS

This institutional review board-approved retrospective study comprised 377 Chinese women who were diagnosed with invasive breast cancer in 2015. This cohort included 53 low-Ki67 expression (Ki67 proliferation index less than 14%) and 324 cases with high-Ki67 expression (Ki67 proliferation index more than 14%). A binary-classification of low-versus high- Ki67 expression was performed. A set of 56 quantitative radiomics features, including morphological, greyscale statistic, and texture features, were extracted from the segmented lesion area. Three machine learning classification methods, including naive Bayes, k-nearest neighbour and support vector machine, were employed for the classification and the least absolute shrink age and selection operator (LASSO) method was used to select most predictive features set for the classifiers. Classification performance was evaluated by the area under receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity.

RESULES

The model that used naive Bayes classification method achieved the best performance than the other two methods, yielding 0.773 AUC, 0.757 accuracy, 0.777 sensitivity and 0.769 specificity. Three most predictive features, i.e., contrast, entropy and line likeness, were selected by the LASSO method and showed a statistical significance (p<0.05) in the classification.

CONCLUSION

The present study showed that quantitative radiomics imaging features of breast tumour extracted from DCE-MRI are associated with breast cancer Ki67 expression. Future larger studies are needed in order to further evaluate the findings.

The effects of a sodium-glucose cotransporter 2 inhibitor on diabetic nephropathy and serum oxidized low-density lipoprotein levels

OBJECTIVE

To investigate the effect of an SGLT-2 inhibitor on diabetic nephropathy and serum oxidized low-density lipoprotein (ox-LDL) levels.

PATIENTS AND METHODS

We randomly divided 126 patients with diabetic nephropathy into the treatment group and control group. The 63 patients in the treatment group received an SGLT-2 inhibitor in addition to routine insulin therapy, while the control group received only insulin to control blood glucose. All laboratory indexes were recorded before and after treatment with the SGLT-2 inhibitor. The prognosis of patients was followed-up. Simultaneously, 63 healthy and BMI-matched in-patients were selected as the healthy control group. Peripheral blood samples were collected from all groups, and the levels of ROS were measured by ELISA.

RESULTS

Renal function indexes such as urinary protein, creatinine, blood urea nitrogen, and glomerular filtration rate (GFR) were significantly higher with SGLT-2 inhibitor treatment compared with the control group (p<0.05). The fasting blood glucose level was not significantly increased before or after treatment (p>0.05). The levels of ROS in peripheral blood were significantly lower in the treatment group than in the control group (p<0.05). Observation at the 1-year follow-up showed that the average GFR was significantly higher in the treatment group than in the control group. Furthermore, the proportion of patients with stage 1-3 chronic kidney disease was significantly higher in the treatment group than in the control group (p<0.05).

CONCLUSIONS

The SGLT-2 inhibitor had a good therapeutic effect on renal function in patients with diabetic nephropathy, without having effects on fasting blood glucose. Additionally, it significantly delayed the progression of nephropathy. It is therefore worth clinical promotion.

A novel role for the Krüppel-like factor 14 on macrophage inflammatory response and atherosclerosis development

Genome-wide association studies have shown that Krüppel-like factor 14 (KLF14) is associated with both Type 2 diabetes mellitus and lipid metabolism. However, its role in chronic inflammatory responses and the pathogenesis of atherosclerosis remains unknown. The present study was designed to investigate both in vivo and in vitro the impact of KLF14 on chronic inflammatory responses and atherosclerosis. ApoE KO mice, a well-established animal model of atherosclerosis, had higher expressions of KLF14 in aorta tissues than that in C57BL/6 J mice when fed the high-fat diet (HFD) or standard chow diet. Adenovirus-mediated KLF14 knockdown markedly reduced the circulating levels of proinflammatory cytokines and the formation of atherosclerotic lesions in HFD-fed ApoE KO mice. In the in vitro study, KLF14 overexpression in the RAW264.7 macrophages significantly increased the expressions of inflammatory cytokines, total cholesterol (TC), cholesteryl ester (CE), and the ratio of CE to TC in the cells treated with acetylated low-density lipoproteins (AcLDL). Conversely, KLF14 knockdown remarkably attenuated AcLDL-induced increase in TC, CE, and the ratio of CE to TC as well as the expressions of inflammatory cytokines. Furthermore, up-regulation or down-regulation of KLF14 markedly elevated or inhibited the phosphorylation levels of p38 MAPK and ERK1/2 in AcLDL-stimulated RAW264.7 macrophages, respectively. Importantly, treatment with p38 MAPK or ERK1/2 inhibitor nullified the effects of KLF14 on inflammatory cytokine expressions in the cells. These data demonstrate an important role for KLF14 expression in atherosclerotic lesion formation.

High resolution polarimeter-interferometer system for fast equilibrium dynamics and MHD instability studies on Joint-TEXT tokamak (invited)

A high-performance Faraday-effect polarimeter-interferometer system has been developed for the J-TEXT tokamak. This system has time response up to 1 μs, phase resolution < 0.1° and minimum spatial resolution ∼15 mm. High resolution permits investigation of fast equilibrium dynamics as well as magnetic and density perturbations associated with intrinsic Magneto-Hydro-Dynamic (MHD) instabilities and external coil-induced Resonant Magnetic Perturbations (RMP). The 3-wave technique, in which the line-integrated Faraday angle and electron density are measured simultaneously by three laser beams with specific polarizations and frequency offsets, is used. In order to achieve optimum resolution, three frequency-stabilized HCOOH lasers (694 GHz, >35 mW per cavity) and sensitive Planar Schottky Diode mixers are used, providing stable intermediate-frequency signals (0.5-3 MHz) with S/N > 50. The collinear R- and L-wave probe beams, which propagate through the plasma poloidal cross section (a = 0.25-0.27 m) vertically, are expanded using parabolic mirrors to cover the entire plasma column. Sources of systematic errors, e.g., stemming from mechanical vibration, beam non-collinearity, and beam polarization distortion are individually examined and minimized to ensure measurement accuracy. Simultaneous density and Faraday measurements have been successfully achieved for 14 chords. Based on measurements, temporal evolution of safety factor profile, current density profile, and electron density profile are resolved. Core magnetic and density perturbations associated with MHD tearing instabilities are clearly detected. Effects of non-axisymmetric 3D RMP in ohmically heated plasmas are directly observed by polarimetry for the first time.

Equilibrium reconstruction based on core magnetic measurement and its applications on equilibrium transition in Joint-TEXT tokamak

Evaluation and reconstruction of plasma equilibrium, especially to resolve the safety factor profile, is imperative for advanced tokamak operation and physics study. Based on core magnetic measurement by the high resolution laser polarimeter-interferometer system (POLARIS), the equilibrium of Joint-TEXT (J-TEXT) plasma is reconstructed and profiles of safety factor, current density, and electron density are, therefore, obtained with high accuracy and temporal resolution. The equilibrium reconstruction procedure determines the equilibrium flux surfaces essentially from the data of POLARIS. Refraction of laser probe beam, a major error source of the reconstruction, has been considered and corrected, which leads to improvement of accuracy more than 10%. The error of reconstruction has been systematically assessed with consideration of realistic diagnostic performance and scrape-off layer region of plasma, and its accuracy has been verified. Fast equilibrium transitions both within a single sawtooth cycle and during the penetration of resonant magnetic perturbation have been investigated.

Laparoscopic colorectomy for colorectal cancer: retrospective analysis of 889 patients in a single center

Laparoscopic colectomy has been reported as an alternative for treatment of colorectal cancer. However, its long-term efficacy and safety remain obscure. The purpose here was to review our experience with laparoscopic colectomy in 899 patients between June 2001 and December 2008. Of them, 43 patients were converted to open surgery and 846 accepted laparoscopic colorectomy successfully. Among these 846 patients, 790 patients underwent radical resection and 56 patients underwent palliative resection. Only 1 patient died from perioperative pulmonary infection; thus the mortality was 0.12% (1/846). The morbidity of perioperative complications was 18.20% (154/846): intraoperative complication rate was 4.49% (38/846) and the most common intraoperative complication was subcutaneous emphysema and hypercapnia (1.65%, 14/846); postoperative complication rate was 13.71% (116/846) and the most common postoperative complication was ileus (4.37%, 37/846). The overall followed-up rate was 86.41% (731/846, 680 for radical operations and 51 palliative operations). Postoperative deaths happened to 139 patients, including 112 after radical operation and 27 after palliative resection. Of these 112 patients, 97 deaths were cancer-related (14.26%, 97/680) and 15 deaths were non-cancer-related. There were 10 patients encountered local recurrence (1.47%, 10/680) and 105 for metastasis (15.44%, 105/680) after radical operation. Forty-two patients are still alive with tumor. Overall survival rate was 80.98% (592/731), 3-year disease-free survival (DFS) rate after radical operation was 78.0%, and 3-year DFS rate after radical operation for stage I, stage II, and stage III was 89.0%, 85.0%, and 65.0%, respectively. In conclusion, laparoscopic colorectal resection is a feasible and safe technology for colorectal cancer.

Large-area organic distributed feedback laser fabricated by nanoreplica molding and horizontal dipping

The fabrication of visible wavelength vertically emitting distributed feedback (DFB) lasers with a subwavelength grating fabricated by a replica molding process and an active polymer layer printed by a horizontal dipping process is reported. The combined techniques enable the organic DFB laser to be uniformly fabricated over large surface areas upon a flexible plastic substrate, with an approach that is compatible with roll-based manufacturing. Using a fixed grating period and depth, DFB laser output wavelength is controlled over a 35 nm range through manipulation of the waveguide layer thickness, which is controlled by the speed of the horizontal dipping process. We also demonstrate that the active area of the structure may be photolithographically patterned to create dense arrays of discrete DFB lasers.

Multiple logistic regression analysis of risk factors for carcinogenesis of oral submucous fibrosis in mainland China

Oral submucous fibrosis (OSF), a chronic progressive disorder, is regarded as the premalignant lesion of oral squamous cell carcinoma (OSCC). Its distribution is associated with chewing betel quid (BQ). The objective of the present study was to investigate risk factors for the carcinogenesis of OSF in mainland China. A case-control study was performed in 42 patients with OSCC that originated from OSF and 40 OSF controls. Epidemiological data and information related to risk factors were collected using a short structured questionnaire. Odd ratios (OR) and 95% confidence intervals (CI) were derived from logistic regression analysis. In multivariate analysis, only age, duration of BQ chewing, duration of cigarette smoking, and OSF accompanied by oral leukoplakia or oral lichen planus were associated with significantly increased risk for the malignant transformation of OSF. These findings contribute to current knowledge on the prevention of carcinogenesis of OSF in mainland China.

FDTD Simulation of Nonlinear Ultrasonic Pulse Propagation in ESWL

The extracorporeal shock wave lithotripsy (ESWL) has come into wide use due to its non-invasive advantage. However, as for the shock wave propagation in human body in relation to practical lithotripsy, there are a few studies on numerical simulation based on models conforming to practical situations. In this paper we report a numerical method of finite difference time domain (FDTD) for analyzing ultrasonic pulse nonlinear propagation in human body tissues and demonstrated it through an experiment of Reichenberger's ESWL in water.

[New method of lymph node tracing in gastrectomy for advanced gastric carcinoma]

OBJECTIVE

To develop a new method of lymph node tracing in gastrectomy for advanced gastric carcinoma (AGC).

METHODS

Forty-six patients with gastric angle carcinoma with metastasis in the third group lymph nodes underwent radical operation. During the operation methylene blue was injected inside or around the border of the metastatic third group lymph nodes. The secondary sentinel lymph nodes (SSLNs) that were the nearest to the third group lymph nodes were searched in 5 approximately 10 minutes, and the SSLNs discovered were resected to undergo HE staining and immunohistochemistry.

RESULTS

SSLNs were found in 38 patients with a positive rate of 82.6% by methylene blue staining. Pathological examination found SSLNs in 30 cases with a positive rate of 78.9%. Totally 68 SSLNs were found in the 38 patients. The numbers of methylene blue positive SSLN in the groups 7, 5, 4, 6, 9, and 8 were 40, 9, 7, 5, 4, and 3 respectively. Pathology and histochemistry found 31, 9, 5, 4, 2, and 1 SSLNs in the groups 7, 5, 4, 6, 9, and 8 with the positive rates of 77.5%, 100%, 71.4%, 80.0%, 50.0%, and 33.3% respectively. There were no significant correlation between the size and degree of differentiation of tumor and the positive rate of SSLN.

CONCLUSION

The technique of SSLN tracing expands the application range of SLN tracing and provides a new thinking for study of lymph node in gastric carcinoma in different stages.

Pulsed Rayleigh wave scattered at a surface crack

This paper investigates Rayleigh wave interaction with machined slots on flat aluminium blocks to simulate surface breaking cracks. Using a finite element method, Rayleigh wave scattering by narrow slots of varied depth ranging from 0.5 mm to 20 mm is calculated. Pulsed wideband Rayleigh waves with a centre frequency of 590 kHz and -6 dB bandwidth of 520 kHz is considered. Reflection and transmission coefficients are calculated and compare well with the published literature. We and other workers have reported enhancement of the measured amplitude or particle velocity of an apparent Rayleigh wave close to a surface defect. In this paper, it is found that the predicted enhancement of in-plane components of particle velocities close to a crack is significantly higher than that of the out-of-plane components of particle velocities which appears to be mainly due to the mode-converted surface skimming longitudinal wave from the crack that has mainly in-plane components near the sample surface. The enhancement of the in-plane particle velocity will be observed regardless of the type of in-plane sensitive ultrasonic detector used. The explanation of the discrepancy of the reflection and transmission coefficients obtained by pulsed and narrow band or pseudo continuous Rayleigh waves is discussed. The later-arriving Rayleigh waves from reverberation along the inside of the crack surface are observed, as has been previously reported by other workers, and this may also be used to gauge slot depth.

Depth gauging of defects using low frequency wideband Rayleigh waves

In non-destructive testing for cracks it is not sufficient to simply detect the presence of a defect, but it is essential to have an accurate measure of the depth. Accurate calibration of the techniques used to gauge defect size is therefore necessary. Recent progress in the field of non-contact ultrasonic testing has led to the development of a practically viable system for generating and detecting wideband Rayleigh waves on electrically conducting or magnetic samples using electro-magnetic acoustic transducers (EMATs). This system has been used to gauge the depth and position of surface breaking defects, and has many applications including metal billet testing and detecting and sizing gauge corner cracking in rails. In this paper we report experiments calibrating the response of EMATs when a defect is present between the generator and receiver, using a calibration sample with slots machined perpendicular to the surface to simulate surface breaking cracks. The depth of the defect can be gauged in the time domain and frequency domain, with an accurate 'fingerprint' of the position given by an enhancement of the signal when the receiver is close to the defect. The best choice of EMAT design for different applications is discussed, as is the best position for the receive EMAT to avoid areas of interference between the Rayleigh wave and bulk waves diffracted from the crack tip.

[Studies on sexual dysfunction in male patients with chronic renal insufficiency]

OBJECTIVES

To investigate the prevalence, main manifestation and related factors of sexual dysfunction in male patients with chronic renal insufficiency (CRI).

METHODS

A cross-section study was conducted by six hospitals in Sichuan Province. The prevalence and severity of sexual dysfunction were assessed by SCASF microsoft among patients with chronic renal disease. Logistic regression was used to examine and test the association between sexual dysfunction and other medical conditions.

RESULTS

The prevalence of sexual dysfunction was wider in patients with CRI than in those without. The main manifestations in male patients were decreased libido, erectile dysfunction and premature ejaculation. Stratified analysis in uremia showed that the prevalence and severity of sexual dysfunction were similar between patients on haemodialysis(HD) and those on peritoneal dialysis(PD). The patients receiving no replacement treatment suffered more decreased libido and performance anxiety than dialyzed patients (HD and PD) and transplantation patients(Tx). The patients receiving no replacement treatment and dialysis suffered more erectile dysfunction than Tx men. A multivariable analysis demonstrated that the duration, creatinine clearance(Ccr), parathyroid hormone (PTH), albumin(Alb) were not associated with sexual dysfunction. The use of beta-blocker, anemia and depression were risky factors for decreased libido, and increasing age was a risky factor for erectile dysfunction. The use of angiotensin-converting-enzyme inhibitor(ACEI)/angiotention receptor antagonist (ARB) and recombinant human erythropoietin(r-HuEpo) were protective factors for erectile dysfunction.

CONCLUSIONS

The main manifestations of sexual dysfunction in male patients with CRI are decreased libido, erectile dysfunction and premature ejaculation. The replacement therapy, especially transplantation, can decrease the prevalence or severity of sexual dysfunction. The genesis of sexual dysfunction is multifactorial, including age, physiological factors, psychological factors and medical conditions.

Gbetagamma affinity for bovine rhodopsin is determined by the carboxyl-terminal sequences of the gamma subunit

Two native betagamma dimers, beta(1)gamma(1) and beta(1)gamma(2), display very different affinities for receptors. Since these gamma subunits differ in both primary structure and isoprenoid modification, we examined the relative contributions of each to Gbetagamma interaction with receptors. We constructed baculoviruses encoding gamma(1) and gamma(2) subunits with altered CAAX (where A is an aliphatic amino acid) motifs to direct alternate or no prenylation of the gamma chains and a set of gamma(1) and gamma(2) chimeras with the gamma(2) CAAX motif at the carboxyl terminus. All the gamma constructs coexpressed with beta(1) in Sf9 cells yielded beta(1)gamma dimers, which were purified to near homogeneity, and their affinities for receptors and Galpha were quantitatively determined. Whereas alteration of the isoprenoid of gamma(1) from farnesyl to geranylgeranyl and of gamma(2) from geranylgeranyl to farnesyl had no impact on the affinities of beta(1)gamma dimers for Galpha(t), the non-prenylated beta(1)gamma(2) dimer had significantly diminished affinity. Altered prenylation resulted in a <2-fold decrease in affinity of the beta(1)gamma(2) dimer for rhodopsin and a <3-fold change for the beta(1)gamma(1) dimer. In each case with identical isoprenylation, the beta(1)gamma(2) dimer displayed significantly greater affinity for rhodopsin compared with the beta(1)gamma(1) dimer. Furthermore, dimers containing chimeric Ggamma chains with identical geranylgeranyl modification displayed rhodopsin affinities largely determined by the carboxyl-terminal one-third of the protein. These results indicate that isoprenoid modification of the Ggamma subunit is essential for binding to both Galpha and receptors. The isoprenoid type influences the binding affinity for receptors, but not for Galpha. Finally, the primary structure of the Ggamma subunit provides a major contribution to receptor binding of Gbetagamma, with the carboxyl-terminal sequence conferring receptor selectivity.

Independent and synergistic interaction of retinal G-protein subunits with bovine rhodopsin measured by surface plasmon resonance

We have used surface plasmon resonance (SPR) measurements for the kinetic analysis of G-protein-receptor interaction monitored in real time. Functionally active rhodopsin was immobilized on an SPR surface, with full retention of biochemical specific activity for catalysis of nucleotide exchange on the retinal G-protein alpha subunit, via binding to immobilized concanavalin A. The binding interactions of bovine retinal alpha(t) and beta(1)gamma(1) subunits with rhodopsin measured by SPR were profoundly synergistic. Synergistic binding of the retinal G-protein subunits to rhodopsin was not observed for guanosine 5'-[gamma-thio]triphosphate-bound Galpha(t), nor was binding observed with squid retinal Galpha(q), which is not activated by bovine rhodopsin. The binding affinity (336+/-171 nM; mean value+/-S.D.) of retinal betagamma for rhodopsin in the presence of retinal alpha subunit measured by SPR confirmed the apparent affinity of 254 nM determined previously by nucleotide exchange assays. Binding of beta(1)gamma(1), beta(1)gamma(2), and beta(1)gamma(8-olf) dimers to rhodopsin, independently of the alpha subunit, was readily observable by SPR. Further, these dimers, differing only in their gamma subunit compositions, displayed markedly distinct binding affinities and kinetics. The beta(1)gamma(2) dimer bound with a kinetically determined K(d) of 13+/-3 nM, a value nearly identical with the biochemically determined K(1/2) of 10 nM. The physiologically appropriate beta(1)gamma(1) displayed rapid association and dissociation kinetics, whereas the other beta(1)gamma dimers dissociated at a rate less than 1/100 as fast. Thus rhodopsin interaction with its native signalling partners is both rapid and transient, whereas the interaction of rhodopsin with heterologous Gbetagamma dimers is markedly prolonged. These results suggest that the duration of a G-protein-coupled receptor signalling event is an intrinsic property of the G-protein coupling partners; in particular, the betagamma dimer.

Two amino acids in the sixth transmembrane segment of the mouse gastrin-releasing peptide receptor are important for receptor activation

The gastrin-releasing peptide receptor (GRP-R) is a G protein-coupled receptor that mediates a variety of cellular responses, including cell growth and modulation of neuronal activity by activation of heterotrimeric GTP-binding proteins in the Gq family. To understand the regulation of GRP-R signaling we have substituted alanine for each of 10 amino acid residues within the transmembrane (TM) helices of the GRP-R predicted to project into the binding pocket of the receptor and analyzed the importance of each of these residues for receptor function. Two mutations showed selective loss of either agonist (Y285A) or antagonist (F313A) affinity for the GRP-R. In addition, we identified two amino acid residues, Phe(270) and Asn(281), in the sixth TM segment, which are important for receptor-G protein interaction. In a competition-binding assay with an antagonist radioligand, bombesin showed a 20- to 100-fold decreased affinity for the N281A and F270A mutant GRP-R compared with wild-type GRP-R. The saturation-binding isotherms are best fit by a two-state model, indicating that the receptors are in either a low-affinity (K(D2)) or a high-affinity (K(D1)) state. The ratio of the two affinities (K(D2)/K(D1)) was significantly increased for both mutants compared with wild-type GRP-R, whereas the fraction of mutant receptors in the high-affinity state (R(1)) was decreased. GDP/guanosine-5'-O-(3-thio)triphosphate exchange catalyzed by the N281A mutant was lower than that observed for the wild-type GRP-R. However, for both mutants, bombesin was still able to stimulate 1,4,5-inositol triphosphate in transfected cells albeit with reduced activity. We conclude that these two TM residues are important for receptor-G protein coupling, and postulate that each mutation may affect GRP-R conformational change to the high-affinity, G protein-coupled state.

Phosphorylation uncouples the gastrin-releasing peptide receptor from G(q)

Previous work on the desensitization of G protein-coupled receptors has focused on the role of arrestin binding following receptor phosphorylation. We have examined the hypothesis that phosphorylation alone contributes to desensitization. In this study we demonstrate that for the G(q)-coupled gastrin-releasing peptide receptor (GRP-R), phosphorylation by GRK2 to a stoichiometry of approximately 1 mol PO(4)/mol GRP-R is sufficient in the absence of arrestin to reduce the rate of receptor catalyzed G protein activation by approximately 80%. Furthermore, GRP-Rs exposed in vivo to agonist are rapidly phosphorylated to a similar stoichiometry and are desensitized to a similar degree. Finally, the molecular mechanism for both in vitro GRK2-induced and in vivo agonist-induced desensitization is primarily a decrease in the maximum velocity (V(max)) for the catalysis of guanine nucleotide exchange by the GRP-R rather than a change in the affinity of the receptor for the alpha(q) or betagamma subunits. Based on these results, we suggest that, for some G protein-coupled receptors, phosphorylation has a role in desensitization that is independent of arrestin.

[Construction of expressing vector for phage display scFv and a mouse unspecified antibody library]

The display of antibody gene library on the surface of E. coli filamentous phage offers a new method of obtaining antibodies against specific antigens. In the paper, it is reported that a phagemid for phage display antibody, named after pFUW80, characterized expressing scFv either secretly or stickily. With a series of designed PCR primers, heavy-chain and light-chain variable region genes of mice antibodies were amplified and a mouse unspecified single-chain antibody library with the size of 1.2 x 10(6) clones was constructed. From this library, phage was selected out against antigen human IgG and detected by ELISA and partial sequence analysis. These primary results established the foundation for future research using this system.

The bombesin receptor subtypes have distinct G protein specificities

We used an in situ reconstitution assay to examine the receptor coupling to purified G protein alpha subunits by the bombesin receptor family, including gastrin-releasing peptide receptor (GRP-R), neuromedin B receptor (NMB-R), and bombesin receptor subtype 3 (BRS-3). Cells expressing GRP-R or NMB-R catalyzed the activation of squid retinal Galphaq and mouse Galphaq but not bovine retinal Galphat or bovine brain Galphai/o. The GRP-R- and NMB-R-catalyzed activations of Galphaq were dependent upon and enhanced by different betagamma dimers in the same rank order as follows: bovine brain betagamma > beta1gamma2 >> beta1gamma1. Despite these qualitative similarities, GRP-R and NMB-R had distinct kinetic properties in receptor-G protein coupling. GRP-R had higher affinities for bovine brain betagamma, beta1gamma1, and beta1gamma2 and squid retinal Galphaq. In addition, GRP-R showed higher catalytic activity on squid Galphaq. Like GRP-R and NMB-R, BRS-3 did not catalyze GTPgammaS binding to Galphai/o or Galphat. However, BRS-3 showed little, if any, coupling with squid Galphaq but clearly activated mouse Galphaq. GRP-R and NMB-R catalyzed GTPgammaS binding to both squid and mouse Galphaq, with GRP-R activating squid Galphaq more effectively, and NMB-R also showed slight preference for squid Galphaq. These studies reveal that the structurally similar bombesin receptor subtypes, in particular BRS-3, possess distinct coupling preferences among members of the Galphaq family.

[Clinic analysis of surgical treatment for benign parotid tumour 55 cases]

OBJECTIVE

To investigate the relationship between 3 kinds of surgical methods and the postoperative recurrence and complication of patients with the benign parotid tumours.

METHOD

The records of benign parotid tumours cases (55 patients), who were treated in 1987-1997 at our hospital, were retrospectively analysed. The operative methods as follows: local excision (20 patients), superficial parotidectomy (28 patients), total parotidectomy (7 patients), facial nerve was anatomied during operation for 35 patients.

RESULT

The rate of tumour recurrence, partial facial nerve paralysis, parotid gland fistula and Frey's syndroms after operation were 14.6% (8/55), 14.6% (8/55), 7.3% (4/55) and 7.3% (4/55) respectively.

CONCLUSION

The operation of superficial parotidectomy or total parotidectomy should be perfromed for benign parotid tumour cases, facial nerve should be anatomied during operation, for reducing tumour recurrence and facial nerve paralysis.

[Morphologic characteristics of dental cuticle on teeth affected by diabetic periodontitis]

OBJECTIVE

To determine the nature of the dental cuticle found on teeth with diabetic periodontitis.

METHODS

Thirteen permanent teeth which were extracted from three diabetic patients with periodontitis were studied, with the control group of 16 healthy teeth extracted for orthodontical reasons, then all the teeth were decalcified with 5% nitric acid, stained with HE, and examinated by using light microscope.

RESULTS

A layer of thick coat, dental cuticle, covered the root surface of the teeth with diabetic periodontitis, and the cuticle which presented regular laminar structure extended from the cementoenamel junction to the apical portion with different thickness from 40 to 80 microns, but no such similar cuticle structure was found on the healthy teeth of the control group.

CONCLUSION

There is abnormal cuticle structure on the teeth of diabetic patients with periodontitis.

[The preventing function of garlic on experimental oral precancer and its effect on natural killer cells, T-lymphocytes and interleukin-2]

In order to study the effect and mechanism of garlic on preventing oral precancer, we divided randomly 32 Wistar rats into two groups. The garlic group was painted with garlic solution on the hard palatal mucosae. The control group was applied with distilled water that is equal in quantity. Then, chemical carinogen 4-nitroquinoline 1-oxide (4NQO) was painted on the same sites for both groups, three times weekly. Eight rats were randomly killed in the 10th, 13th week. The hard palatal mucosae were examined with light microscope. Meanwhile, lymphocytes were isolated from the rat spleens. The activation of natural killer (NK) cells and T-lymphocytes, and level of interleukin-2 were determined by radioimmunoassay. The results revealed that garlic effectively prevented oral precancer induced by 4NQO. This effect may be related to the following factors that garlic can improve the activation of NK cells, the function of T-lymphocytes, and the level of IL-2.

[A study of anaerobic infection in maxillofacial region]

To analyse the anaerobic infection of maxillofacial surgery and estimate the efficacy of antianaerobic therapy, 45 patients were divided into two groups, tinidazole group and metronidazole group. Bacterial culture was positive before treating in all cases. There were Bacillus Melaniogenicus, Veillonella, Peptococcus and Peptostreptococus, etc. There was excellent efficacy in the treatment of maxillofacial anaerobic infection by tinidazole intravenously. After treatment, the result of bacterial examination was negative. The healing rate was 96.4% in 28 cases which used tinidazol, but 82.4% in control group which used metronidazole. The value of white blood cell and the function of liver and kidney pro- and post-treatment were not significantly different (P < 0.05) by comparision.

Myosin light chain kinase: expression in neurons and upregulation during axon regeneration

Myosin light-chain kinase (MLCK) regulates actin-myosin II interactions in nonskeletal muscle cells, and the use of specific pharmacological inhibitors has implicated MLCK in retinal growth cone motility and neurite outgrowth. To further establish the existence and functions of MLCK in neurons, we isolated cDNAs encoding two forms of goldfish MLCK that were differentially expressed in the brain and gut and we sequenced the form most abundantly expressed in the brain (GFMLCK1). In situ hybridization with a cRNA probe specific to GFMLCK1 revealed widespread expression in CNS neurons, including tectal periventricular neurons and cerebellar and medullary neurons. After optic nerve crush, expression was markedly increased in the retinal ganglion cells. Expression peaked during the phase of axonal outgrowth, which, when taken together with our previous pharmacological studies, further supports a role for MLCK in growth cone motility.

[Surgical treatment of unilateral alveolar cleft]

In this study, 16 cases of unilateral alveolar cleft with cleft lip and palate were repaired with autografts of cancellous bone (13 cases) or hydroxyapatite (3 cases). The grafts were covered by reflected mucoperiosteal flaps and a mucosal flap from the upper lip. Twelve of the thirteen cases were followed up for 1-5 years. Nine of whom using cancellous bone had bony continuity of the maxilla and 7 cases erupted permanent maxillary canines within the area of autografts. None of the 3 cases using hydroxyapatite erupted a canine tooth. The results showed that autograft was better than hydroxyapatite in terms of maxillary canine eruption.

Changes in distribution of labile zinc in mouse spermatozoa during maturation in the epididymis assessed by the fluorophore Zinquin

The Zn(II)-specific fluorophore Zinquin was used to determine the regional distribution of free or loosely-bound Zn(II) in mouse spermatozoa. Spermatozoa from the testes exhibited bright fluorescence over the entire head; those from the caput epididymides generally fluoresced more brightly in the post-acrosomal region; and spermatozoa from the caudae epididymides fluoresced less brightly, with foci of fluorescence over the sperm head which were lost after extraction with Triton X-100 and hence appeared to be membrane-associated. Treatment of cauda sperm with sodium dodecyl sulfate resulted in a bright uniform Zinquin fluorescence in the heads, similar to that observed in caput sperm, indicating that the two types of sperm have similar amounts of head Zn(II) but that the availability of Zn(II) for binding Zinquin is different. By contrast, the intensity of tail fluorescence was similar in spermatozoa from different regions of the male reproductive tract and was largely unaffected by Triton X-100 extraction, consistent with an intracellular location. Similar differences were observed between caput sperm and cauda sperm in the rat. It is concluded that visualization and measurement of free or loosely-bound Zn(II) in subcellular compartments of spermatozoa should facilitate investigation of the role of this metal in the development and function of spermatozoa and abnormalities that might accompany infertility and Zn(II) deficiency.

Kinase requirement for retinal growth cone motility

Since cytoplasmic Ca2+ levels are reported to regulate neurite elongation, we tested whether calcium-activated kinases might be necessary for growth cone motility and neurite elongation in explant cultures of goldfish retina. Kinase inhibitors and activators were locally applied by micropipette to retinal growth cones and the responses were observed via phase-contrast videomicroscopy. In some cases, growth rates were also quantified over several hours after general application in the medium. The selective inhibitors of protein kinase C, calphostin C (0.1-1 microM) and chelerythrin (up to 50 microM), caused no obvious changes in growth cones or neurite elongation, and activators of PKC (phorbols, arachidonic acid, and diacylglycerol) also were generally without effects, although phorbols slowed the growth rate. Inhibitors of protein kinase A and tyrosine kinases also produced no obvious effects. The calmodulin antagonists, calmidazolium (0.1 microM), trifluoperazine (100 microM), and CGS9343B (50 microM), however, caused a reversible growth cone arrest with loss of filopodia and lamellipodia. The growth cone became a club-shaped swelling which sometimes moved a short distance back the shaft, leaving evacuated filaments at points of strong filopodial attachments. A similar reversible growth cone arrest occurred with the general kinase inhibitors: H7 at 200 but not at 100 microM, and staurosporine at 100 but not 10 nM, suggesting possible involvement of a calmodulin-dependent kinase (camK) rather than PKC. The selective inhibitor of camKII, KN-62 (tested up to 50 microM), produced no effects, but the specific myosin light-chain kinase (MLCK) inhibitors ML-7 (3-5 microM) and ML-9 (5-10 microM) reversibly reproduced the effect, suggesting that MLCK rather than camKII is necessary for growth cone motility. The MLCK inhibitors' effects both on growth cone morphology and on F-actin filaments (rhodamine-phalloidin staining) were similar to those caused by cytochalasin D (5 microM), and are discussed in light of findings that inhibiting MLCK disrupts actin filaments in astrocytes and fibroblasts.