bluuebunny/crossref_metadata_2025 huggingface dataset:
Brain systems for baroreflex suppression during stress in humans
Authors: Gianaros Peter J. , Onyewuenyi Ikechukwu C. , Sheu Lei K. , Christie Israel C. , Critchley Hugo D.
Published: May 2011

The arterial baroreflex is a key mechanism for the homeostatic control of blood pressure (BP). In animals and humans, psychological stressors suppress the capacity of the arterial baroreflex to control short‐term fluctuations in BP, reflected by reduced baroreflex sensitivity (BRS). While animal studies have characterized the brain systems that link stressor processing to BRS suppression, comparable human studies are lacking. Here, we measured beat‐to‐beat BP and heart rate (HR) in 97 adults who performed a multisource interference task that evoked changes in spontaneous BRS, which were quantified by a validated sequence method. The same 97 participants also performed the task during functional magnetic resonance imaging (fMRI) of brain activity. Across participants, task performance (i) increased BP and HR and (ii) reduced BRS. Analyses of fMRI data further demonstrated that a greater task‐evoked reduction in BRS covaried with greater activity in brain systems important for central autonomic and cardiovascular control, particularly the cingulate cortex, insula, amygdala, and midbrain periaqueductal gray (PAG). Moreover, task performance increased the functional connectivity of a discrete area of the anterior insula with both the cingulate cortex and amygdala. In parallel, this same insula area showed increased task‐evoked functional connectivity with midbrain PAG and pons. These novel findings provide human evidence for the brain systems presumptively involved in suppressing baroreflex functionality, with relevance for understanding the neurobiological mechanisms of stressor‐related cardiovascular reactivity and associated risk for essential hypertension and atherosclerotic heart disease. Hum Brain Mapp, 2011. © 2011 Wiley‐Liss, Inc.
Branched-chain amino acids as pharmacological nutrients in chronic liver disease
Authors: Kawaguchi Takumi , Izumi Namiki , Charlton Michael R. , Sata Michio
Published: May 2011

Branched-chain amino acids (BCAAs) are a group of essential amino acids comprising valine, leucine, and isoleucine. A low ratio of plasma BCAAs to aromatic amino acids is a physiological hallmark of liver cirrhosis, and BCAA supplementation was originally devised with the intention of normalizing amino acid profiles and nutritional status. However, recent studies on BCAAs have revealed that, in addition to their role as protein constituents, they may have a role as pharmacological nutrients for patients with chronic liver disease. Large-scale, multicenter, randomized, double-blinded, controlled trials on BCAA supplementation have been performed in Italy and Japan, and results demonstrate that BCAA supplementation improves not only nutritional status, but also prognosis and quality of life in patients with liver cirrhosis. Moreover, accumulating experimental evidence suggests that the favorable effects of BCAA supplementation on prognosis may be supported by unforeseen pharmacological actions of BCAAs. This review summarizes the possible effects of BCAAs on albumin synthesis and insulin resistance from clinical and basic viewpoints. We also review the newly discovered clinical impact of BCAAs on hepatocellular carcinoma and the prognosis and quality of life of patients with liver cirrhosis. (HEPATOLOGY 2011;)
Obesity is an independent risk factor for clinical decompensation in patients with cirrhosis
Authors: Berzigotti Annalisa , Garcia-Tsao Guadalupe , Bosch Jaime , Grace Norman D. , Burroughs Andrew K. , Morillas Rosa , Escorsell Angels , Garcia-Pagan Juan Carlos , Patch David , Matloff Daniel S. , Groszmann Roberto J.
Published: May 2011

Obesity is associated with an aggressive course in chronic viral hepatitis; however, its impact in the development of clinical decompensation (CD) in patients with established cirrhosis is uncertain. We evaluated the role of obesity, in relationship to other recognized predictors, in the development of CD in patients with compensated cirrhosis. The study population, a subset of patients included in a randomized trial of beta-blockers in the prevention of varices in whom data on body mass index (BMI) was available, consisted of 161 patients with compensated cirrhosis. Laboratory tests and portal pressure (assessed by the hepatic venous pressure gradient or HVPG) were assessed on inclusion. Patients were followed until CD (ascites, hepatic encephalopathy, or variceal hemorrhage), or until September 2002. Altogether, 29% had a normal BMI, 40% were overweight, and 30% were obese. In a median follow-up of 59 months, CD occurred in 48/161 (30%) patients with an increasingly higher rate according to BMI group (15% in those with normal BMI; 31% in overweight; 43% in obese patients,

P

= 0.011). The actuarial probability of developing CD was significantly higher in the abnormal BMI groups (

P

= 0.022). In a multivariate model that included parameters previously identified as being predictive of CD (HVPG, albumin, Mayo endstage liver disease score), etiology, and treatment group, BMI (hazard ration 1.06; 95% confidence interval 1.01-1.12),

P

= 0.02] was an independent predictor of decompensation, together with HVPG and albumin.

Conclusion

: Obesity has a deleterious effect on the natural history of compensated cirrhosis of all etiologies, independent of portal pressure and liver function. Weight reduction may be a valuable therapeutic measure in this patient population. (Hepatology 2011;)
Complementary vascular and matrix regulatory pathways underlie the beneficial mechanism of action of sorafenib in liver fibrosis
Authors: Thabut Dominique , Routray Chittaranjan , Lomberk Gwen , Shergill Uday , Glaser Kevin , Huebert Robert , Patel Leena , Masyuk Tetyana , Blechacz Boris , Vercnocke Andrew , Ritman Erik , Ehman Richard , Urrutia Raul , Shah Vijay
Published: May 2011

Paracrine signaling between hepatic stellate cells (HSCs) and liver endothelial cells (LECs) modulates fibrogenesis, angiogenesis, and portal hypertension. However, mechanisms regulating these processes are not fully defined. Sorafenib is a receptor tyrosine kinase inhibitor that blocks growth factor signaling in tumor cells but also displays important and not yet fully characterized effects on liver nonparenchymal cells including HSCs and LECs. The aim of this study was to test the hypothesis that sorafenib influences paracrine signaling between HSCs and LECs and thereby regulates matrix and vascular changes associated with chronic liver injury. Complementary magnetic resonance elastography, micro–computed tomography, and histochemical analyses indicate that sorafenib attenuates the changes in both matrix and vascular compartments that occur in response to bile duct ligation–induced liver injury in rats. Cell biology studies demonstrate that sorafenib markedly reduces cell–cell apposition and junctional complexes, thus reducing the proximity typically observed between these sinusoidal barrier cells. At the molecular level, sorafenib down-regulates angiopoietin-1 and fibronectin, both released by HSCs in a manner dependent on the transcription factor Kruppel-like factor 6, suggesting that this pathway underlies both matrix and vascular changes associated with chronic liver disease.

Conclusion:

Collectively, the results of this study demonstrate that sorafenib inhibits both matrix restructuring and vascular remodeling that accompany chronic liver diseases and characterize cell and molecular mechanisms underlying this effect. These data may help to refine future therapies for advanced gastrointestinal and liver diseases characterized by abundant fibrosis and neovascularization. (Hepatology 2011;)
Chemical tags: Applications in live cell fluorescence imaging
Authors: Wombacher Richard , Cornish Virginia W.
Published: May 2011

Technologies to visualize cellular structures and dynamics enable cell biologists to gain insight into complex biological processes. Currently, fluorescent proteins are used routinely to investigate the behavior of proteins in live cells. Chemical biology techniques for selective labeling of proteins with fluorescent labels have become an attractive alternative to fluorescent protein labeling. In the last ten years the progress in the development of chemical tagging methods have been substantial offering a broad palette of applications for live cell fluorescent microscopy. Several methods for protein labeling have been established, using protein tags, peptide tags and enzyme mediated tagging. This review focuses on the different strategies to achieve the attachment of fluorophores to proteins in live cells and cast light on the advantages and disadvantages of each individual method. Selected experiments in which chemical tags have been successfully applied to live cell imaging will be discussed and evaluated. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diabetic retinopathy and signaling mechanism for activation of matrix metalloproteinase‐9
Authors: Mohammad Ghulam , Kowluru Renu A.
Published: May 2011

In the pathogenesis of diabetic retinopathy, H‐Ras (a small molecular weight G‐protein) and matrix metalloproteinase‐9 (MMP9) act as pro‐apoptotic, accelerating the apoptosis of retinal capillary cells, a phenomenon that predicts its development and the activation of MMP9 is under the control of H‐Ras. The goal of this study is to elucidate the cellular mechanism by which H‐Ras activates MMP9 culminating in the development of diabetic retinopathy. Using isolated retinal endothelial cells, the effect of regulation of H‐Ras downstream signaling cascade, Raf‐1, MEK, and ERK, was investigated on glucose‐induced activation of MMP9. In vitro results were confirmed in the retina obtained from diabetic mice manipulated for MMP9 gene, and also in the retinal microvasculature obtained from human donors with diabetic retinopathy. Regulation of Raf‐1/MEK/ERK by their specific siRNAs and pharmacologic inhibitors prevented glucose‐induced activation of MMP9 in retinal endothelial cells. In MMP9‐KO mice, diabetes had no effect on retinal MMP9 activation, and H‐Ras/Raf‐1/MEK signaling cascade remained normal. Similarly, donors with diabetic retinopathy had increased MMP9 activity in their retinal microvessels, the site of histopathology associated with diabetic retinopathy, and this was accompanied by activated H‐Ras signaling pathway (Raf‐1/ERK). Collectively, these results suggest that Ras/Raf‐1/MEK/ERK cascade has an important role in the activation of retinal MMP9 resulting in the apoptosis of its capillary cells. Understanding the upstream mechanism responsible for the activation of MMP9 should help identify novel molecular targets for future pharmacological interventions to inhibit the development/progression of diabetic retinopathy. J. Cell. Physiol. 227: 1052–1061, 2012. © 2011 Wiley Periodicals, Inc.
MicroRNAs in the midst of myeloid signal transduction
Authors: Stoffers Sara L. , Meyer Sara E. , Grimes H. Leighton
Published: May 2011

MicroRNA (miRNA) play important roles in the development and physiological function of hematopoietic stem/progenitor and mature cell lineages. In addition, deregulated miRNA expression and subsequent gene expression changes are associated with hematologic diseases including myelodysplastic syndromes and acute myeloid leukemia. This review focuses on myelopoiesis as a model to highlight the involvement of miRNA in the regulation of normal and malignant cellular signaling pathways. By incorporating miRNA regulation into well‐established myeloid signal transduction pathways, we hope to shed light on targetable factors both upstream and downstream of miRNA signaling. These pathway‐specific miRNA functions suggest scenarios wherein miRNA‐based therapeutics may be beneficial either alone or in combination with current therapies. J. Cell. Physiol. 227: 525–533, 2012. © 2011 Wiley Periodicals, Inc.
HIV‐1 Nef perturbs the function, structure, and signaling of the Golgi through the Src Kinase Hck
Authors: Hiyoshi Masateru , Takahashi‐Makise Naoko , Yoshidomi Yuka , Chutiwitoonchai Nopporn , Chihara Takashi , Okada Masato , Nakamura Nobuhiro , Okada Seiji , Suzu Shinya
Published: May 2011

The interaction between HIV‐1 Nef and the Src kinase Hck in macrophages has been shown to accelerate the progression to AIDS. We previously showed that Nef disturbed the N‐glycosylation/trafficking of Fms, a cytokine receptor essential for maintaining macrophages in an anti‐inflammatory state, in an Hck‐dependent manner. Here, we show the underlying molecular mechanism of this effect. Using various Hck isoforms and their mutants and Golgi‐targeting Hck mutants, we confirmed that Hck activation at the Golgi causes the Nef‐induced Fms N‐glycosylation defect. Importantly, we found that both the co‐expression of Nef and Hck and the expression of a Golgi‐targeted active Hck mutant caused alterations in the distribution of GM130, a Golgi protein that was shown to be required for efficient protein glycosylation. Moreover, the activation of Hck at the Golgi caused strong serine phosphorylation of the GM130‐interacting Golgi structural protein GRASP65, which is known to induce Golgi cisternal unstacking. Using pharmacological inhibitors, we also found that the activation of Hck at the Golgi followed by the activation of the MAP kinase ERK‐GRASP65 cascade is involved in the Fms N‐glycosylation defect. These results suggest that Nef perturbs the structure and signaling of the Golgi by activating Hck at the Golgi, and thereby, induces the N‐glycosylation/trafficking defect of Fms, which is in line with the idea that Src family kinases are crucial Golgi regulators. J. Cell. Physiol. 227: 1090–1097, 2012. © 2011 Wiley Periodicals, Inc.
Stromal cell‐derived factor‐1/CXC receptor 4 and β1 integrin interaction regulates urokinase‐type plasminogen activator expression in human colorectal cancer cells
Authors: Huang Wen‐Shih , Chin Chih‐Chien , Chen Cheng‐Nan , Kuo Yi‐Hung , Chen Te‐Chuan , Yu Hong‐Ren , Tung Shui‐Yi , Shen Chien‐Heng , Hsieh Yung‐Yu , Guo Su‐Er , Shi Chung‐Sheng , Liu Ta‐Ju , Kuo Hsing‐Chun
Published: May 2011

The stromal cell‐derived factor‐1 (SDF‐1)/CXC receptor 4 (CXCR4) axis has been shown to play a role in colorectal cancer progression. In addition, the protease urokinase‐type plasminogen activator (uPA) is an important factor in tumor cell invasion and metastasis. However, the mechanism by which SDF‐1 mediates uPA expression in human colorectal cancer cells remains unknown. We investigated the molecular mechanism governing the interaction between SDF‐1 stimulation and uPA expression in three human colon cancer cell lines (DLD‐1, SW48, and COLO 205). We found that SDF‐1 stimulation led to an increase in the expression and secretion of uPA in these cells. Experiments involving specific inhibitors and small interfering RNA demonstrated that the activation of p38 mitogen‐activated protein kinase (MAPK) and phosphatidylinositol 3‐kinase (PI3K)/Akt pathways are critical for SDF‐1‐induced uPA expression. Analysis of transcription factor binding using ELISA and chromatin immunoprecipitation assays revealed that SDF‐1 increased Sp1‐ and AP‐1‐DNA‐binding activities in DLD‐1 cells. Inhibition of Sp1 and AP‐1 activation blocked the SDF‐1‐induced expression and activity of the uPA promoter. The effect of SDF‐1 on DLD‐1 signaling and uPA expression was mediated by the CXCR4/β1 integrin axis. In summary, our findings elucidate the mechanisms of SDF‐1/CXCR4 downstream signaling and provide insights into the function of SDF‐1 in colon cancer cells. J. Cell. Physiol. 227: 1114–1122, 2012. © 2011 Wiley Periodicals, Inc.
Role of lipoxin A4 in the cell‐to‐cell interaction between all‐trans retinoic acid‐treated acute promyelocytic leukemic cells and alveolar macrophages
Authors: Tsai Wen‐Hui , Shih Chung‐Hung , Wu Hung‐Yi , Chien Hong‐Yu , Chiang Yee‐Chen , Lai Shu‐Lien , Hsu Shau‐Chieh , Kou Yu Ru , Hsu Hui‐Chi
Published: May 2011

Differentiation therapy with all‐trans retinoic acid (ATRA) has been used successfully to treat acute promyelocytic leukemia (APL), but such treatment also causes differentiation syndrome (DS) by inducing APL cell infiltration into alveolar spaces. The mechanism underlying the clearance of infiltrated APL cells has not been investigated in detail. Lipoxin A4 (LXA4) is an important anti‐inflammatory mediator during the resolution of inflammation. In this study, the role of LXA4 in the cell–cell interaction between alveolar macrophages (AMϕ; NR8383 cells) and APL NB4 cells was investigated and found that conditioned medium (CM) harvested from ATRA‐treated NR8383 (ATRA‐NR8383) cells was able to induce the transmigration of ATRA‐NB4 cells. However, the pro‐migratory activity of CM was attenuated progressively when ATRA‐NR8383 cells were co‐cultured with increased cell dosages of apoptotic NB4 cells. A significantly higher amount of LXA4 was released into the CM by ATRA‐NR8383 cells when they were co‐cultured with apoptotic ATRA‐NB4 cells. Expression of a receptor for LXA4 (ALX/FPR2) was enhanced in both ATRA‐NB4 cells and ATRA‐NR8383 cells. Exogenous LXA4 treatment was able to inhibit the transmigration of ATRA‐NB4 cells and induce the phagocytic clearance of apoptotic cells by ATRA‐NR8383 cells. The anti‐migratory activity of exogenous LXA4 was attenuated by pre‐treating ATRA‐NB4 cells with an ALX/FPR2 inhibitor. We conclude that AMϕ‐derived LXA4 plays an important role in the interaction between AMϕ and APL cells and that this contributes to clearance of apoptotic APL cells. J. Cell. Physiol. 227: 1123–1129, 2012. © 2011 Wiley Periodicals, Inc.
Free fatty acids induce transglutaminase 2‐dependent apoptosis in hepatocytes via ER stress‐stimulated PERK pathways
Authors: Kuo Ting‐Fang , Tatsukawa Hideki , Matsuura Tomokazu , Nagatsuma Keisuke , Hirose Shigehisa , Kojima Soichi
Published: May 2011

Non‐alcoholic steatohepatitis (NASH), a progressive form of fatty liver, shares histological similarities with alcoholic steatohepatitis (ASH), including accumulated fat, hepatic apoptosis, and fibrous tissues in the liver, but the molecular mechanisms responsible for hepatic apoptosis remain unclear. We previously reported that transglutaminase 2 (TG2), induced in the nuclei of ethanol‐treated hepatocytes, crosslinks and inactivates the transcription factor Sp1, leading to hepatic apoptosis. In this study, we investigated whether a similar change is involved in NASH, and if so, how TG2 and crosslinked Sp1 (CLSp1) are induced. Elevated nuclear TG2 and CLSp1 formation was demonstrated in NASH patients, as well as increased activation of apoptosis inducing factor (AIF) and release of cytochrome c. In Hc human normal hepatocytes treated with free fatty acids (FFAs), biochemical analyses revealed that ethanol and FFAs provoked fat accumulation, endoplasmic reticulum (ER) stress, increased nuclear factor kappa B (NFκB), and nuclear TG2. Salubrinal, a selective inhibitor of the ER stress‐induced pancreatic ER kinase (PERK) signaling pathway, inhibited NFκB activation, nuclear TG2 expression, and apoptosis only if it was induced by FFAs, but not by ethanol. These results suggest that FFAs could increase ER stress and lead to nuclear NFκB activation and TG2 induction through PERK‐dependent pathways, resulting in TG2‐mediated apoptosis accompanying crosslinking and inactivation of Sp1, activation of AIF, and release of cytochrome c. J. Cell. Physiol. 227: 1130–1137, 2012. © 2011 Wiley Periodicals, Inc.
Role of senescent fibroblasts on alkali‐induced corneal neovascularization
Authors: Zhou Qingjun , Yang Lingling , Qu Mingli , Wang Yao , Chen Peng , Wang Yiqiang , Shi Weiyun
Published: May 2011

Cellular senescence acts as a potent regulator of tumor suppression and fibrosis limitation; however, its contribution and crosstalk with neovascularization during normal wound healing has not been examined. Here, we explored the role of senescent fibroblasts on neovascularization with a mouse model of alkali‐induced corneal wound healing. Senescent cells accumulated in corneal stroma from day 7 to 27 after alkali burn and peaked on day 14, which was consistent with the development of corneal neovascularization (CNV). In vitro and in vivo assays confirmed that the senescent cells were derived primarily from activated corneal fibroblasts. Furthermore, senescent corneal fibroblasts exhibited enhanced synthesis and secretion of extracellular matrix‐degrading enzymes (matrix metalloproteinases 2, 3, and 14 and tissue‐ and urokinase‐type plasminogen activators) and angiogenic factors (vascular endothelial growth factor) and decreased expression of anti‐angiogenic factors (pigment epithelium‐derived factor and thrombospondins), which supported the proliferation, migration, and promotion of tube formation of vascular endothelial cells. Intrastromal injection of premature senescent fibroblasts induced CNV earlier than that of normal fibroblasts, while matrix metalloproteinase inhibitors blocked the early onset of senescent cell‐induced CNV. Therefore, senescent fibroblasts promoted the alkali‐induced CNV partially via the enhanced secretion of matrix metalloproteases. J. Cell. Physiol. 227: 1148–1156, 2012. © 2011 Wiley Periodicals, Inc.
Human nuclear clusterin mediates apoptosis by interacting with Bcl‐XL through C‐terminal coiled coil domain
Authors: Kim Nayoung , Yoo Jae Cheal , Han Jae Yoon , Hwang Eun Mi , Kim Yoon Sook , Jeong Eun Young , Sun Choong‐Hyun , Yi Gwan‐Su , Roh Gu Seob , Kim Hyun Joon , Kang Sang Soo , Cho Gyeong Jae , Park Jae‐Yong , Choi Wan Sung
Published: May 2011

Clusterin (CLU), a glycoprotein, is involved in apoptosis, producing two alternatively spliced isoforms in various cell types. The pro‐apoptotic CLU appears to be a nuclear isoform (nuclear clusterin; nCLU), and the secretory CLU (sCLU) is thought to be anti‐apoptotic. The detailed molecular mechanism of nCLU as a pro‐apoptotic molecule has not yet been clear. In the current study, overexpressed nCLU induced apoptosis in human kidney cells. Biochemical studies revealed that nCLU sequestered Bcl‐XL via a putative BH3 motif in the C‐terminal coiled coil (CC2) domain, releasing Bax, and promoted apoptosis accompanied by activation of caspase‐3 and cytochrome c release. These results suggest a novel mechanism of apoptosis mediated by nCLU as a pro‐apoptotic molecule. J. Cell. Physiol. 227: 1157–1167, 2012. © 2011 Wiley Periodicals, Inc.
Sorptive sequestration of 2‐chlorophenol by zeolitic materials derived from bagasse fly ash
Authors: Shah Bhavna , Tailor Ritesh , Shah Ajay
Published: May 2011

BACKGROUND: Water pollution by toxic organic compounds is of great concern and increasingly there are demands for effective sorbents to remove them. Bagasse fly ash, a sugar industry solid waste with disposal problems, was utilized as a source for the synthesis of zeolitic material. The efficiency of virgin and synthesized material was examined for the sorption of 2‐chlorophenol.

RESULTS: Zeolitic materials have been synthesized by alkaline hydrothermal and fusion methods. Zeolite P and Analcime were the major components of the zeolitic material. These materials were characterized by XRF, PXRD, FTIR and SEM and were found to have improved morphology with new crystalline phases. Batch sorption experiments for the removal of 2‐chlorophenol by virgin and zeolitic materials were carried out to evaluate isotherm capacities and kinetics of sorption processes. The Langmuir isotherm better fits the equilibrium data which concur with physical sorption. Kinetic studies showed better correlation coefficients for pseudo‐second‐order and intraparticle diffusion model, confirming that the sorption rate was controlled by film diffusion followed by pore diffusion. Desorption studies were performed to regenerate the activity of the spent sorbents. The practical utility of sorbents was tested by column study.

CONCLUSION: Bagasse fly ash, readily available at very low cost was successfully converted into zeolitic material. The synthesized zeolitic material showed enhanced capacities for the sorption of 2‐chlorophenol and can be utilized as a low cost sorbent for treatment of phenolic waste‐water. Copyright © 2011 Society of Chemical Industry
Electrochemical synthesis of dimethyl carbonate from methanol, CO2 and propylene oxide in an ionic liquid
Authors: Yan Cuihong , Lu Bin , Wang Xiaoguang , Zhao Jingxiang , Cai Qinghai
Published: May 2011

BACKGROUND: Dimethyl carbonate (DMC) can be used effectively as an environmentally benign substitute for highly toxic phosgene and dimethyl sulfate in carbonylation and methylation, as well as a promising octane booster owing to its high oxygen content. Two‐step transesterification from epoxide, methanol, and CO2 is widely used in the bulk production of DMC. However, major disadvantages of this process are high energy consumption, and high investment and production costs. A one pot synthesis of DMC from carbon dioxide, methanol, and epoxide was, therefore, developed. But the yields of DMC are below 70% due to the thermodynamic limitation.

RESULTS: Electrochemical synthesis of DMC was conducted with platinum electrodes from methanol, CO2 and propylene oxide in an ionic liquid was conducted. The bmimBr (1‐butyl‐3‐methylimidazolium bromide)‐methanol‐propylene oxide system with CO2 bubbling allows DMC to be effectively synthesized and a high yield (75.5%) was achieved.

CONCLUSION: In this electrolysis, redox reactions of substrates, CO2, methanol, and propylene oxide, on Pt electrodes were carried out, producing the activated particles, CH3O−, CH3OH+, CO2− and PO−, resulting in the effective synthesis of DMC with a 75.5% yield in an ionic liquid (bmimBr). Finally, a mechanism for this synthesis reaction was proposed, which is very different from those reported in the literature. Copyright © 2011 Society of Chemical Industry
Recovery of nickel from spent catalysts using ultrasonication‐assisted leaching
Authors: Oza Rachit , Shah Nikhil , Patel Sanjay
Published: May 2011

BACKGROUND: Solid catalysts containing metals or metal oxides play a key role in the chemical process industries to produce valuable products and fuels and consequently are left as solid wastes after a certain period of use. Disposal of these spent catalysts requires compliance with stringent environmental regulations because of their hazardous nature and content of toxic chemicals. Therefore recovery of the metals by various methods has been explored. In the present study recovery of nickel from spent nickel catalysts using ultrasonication‐assisted leaching has been investigated.

RESULT: The effect on nickel recovery of acid concentration, temperature, solid to liquid (S:L) ratio, and time of digestion were studied in detail and optimized for the ultrasonication route. The results obtained are compared with the chelation route and conventional acid leaching technique. Using ultrasonication‐assisted leaching 95% extraction of nickel was achieved at 90 °C, 40% nitric acid concentration and S:L ratio 1:10 (g:mL) in 50 min from the spent nickel–alumina catalysts.

CONCLUSION: Using an ultrasonication technique 95% recovery of nickel was significantly faster (50 min) than the chelation route (7 h), while with conventional acid leaching a maximum of 93% nickel recovery was obtained in 9 h. Compared with conventional acid leaching the purity of leached nickel salts was good and they could be recycled for the preparation of fresh catalysts after removing Al impurities. Copyright © 2011 Society of Chemical Industry
Digital image inpainting and microscopy imaging
Authors: Stanciu Stefan G. , Hristu Radu , Stanciu George A.
Published: May 2011

A considerable amount of image processing techniques known as inpainting techniques have been recently developed aiming to provide solutions for filling in missing or damaged regions in a digital image. Typical such techniques reconstruct a defined area by using information from its neighborhood, for example, by completing inside the missing region the isophote lines arriving at its boundaries. In this article, we show that inpainting techniques have considerable potential usefulness in microscopy imaging, even though experimenting and using them in this domain has been almost entirely neglected up until now. In this purpose, we experiment the “curvature‐preserving” partial differential equations as a solution to inpainting regions in images collected by several optical and scanning probe microscopy techniques. The results achieved are presented along with a discussion on typical problematic scenarios of microscopy imaging for which this type of techniques can provide a viable solution. Microsc. Res. Tech., 2011. © 2011 Wiley Periodicals, Inc.
Effects of fluoride or nanohydroxiapatite on roughness and gloss of bleached teeth
Authors: Pedreira De Freitas Ana Carolina , Botta Sérgio Brossi , Teixeira Fernanda De Sá , Salvadori Maria Cecília Barbosa Silveira , Garone‐Netto Narciso
Published: May 2011

Objectives:

The aim of this study was to describe roughness and gloss alterations of enamel after treatment with 38% hydrogen peroxide (HP) and after polishing with 2% neutral sodium fluoride (SF) or a dental tooth paste containing nanohydroxiapatite particles (nHA) using power spectral density (PSD) description, roughness parameters (Ra, RMS, and Z range) and gloss analysis.

Methods:

An atomic force microscope (AFM) and a spectrophotometer were used to analyze eighteen specimens of upper incisors. After initial analyses, all specimens were bleached with 38% HP for 135 min. The specimens were analyzed after bleaching. Nine specimens were polished with SF (Group Fluor) and the other nine specimens were polished with nHA (Group nHA), then all specimens were analyzed after polishing. Roughness and gloss were analyzed with ANOVA and Tukey's t‐test.

Results:

No statistical difference was found for Ra and RMS among initial, after bleaching and after polishing in both groups. For Z range, Group nHA showed a significant decrease after polishing. Bleaching with 38% HP did not increase the PSD in the spatial frequency of the visible light spectrum range in both groups. After polishing, nHA group showed a decrease in PSD for all morphological wavelengths. Gloss did not show statistical difference after bleaching in both groups. Gloss showed significant increase after polishing with nHA.

Significance:

bleaching treatment with 38% HP didn't alter enamel surface roughness or gloss. PSD analyses were very suitable to identifying the morphological changes on the surfaces. Microsc. Res. Tech., 2011. © 2011 Wiley Periodicals, Inc.
Ultrastructure of submandibular salivary glands of mouse: TEM and HRSEM observations
Authors: Pícoli Lara Cristina , Dias Fernando José , Issa João Paulo Mardegan , Ogawa Koichi , Ciena Adriano , Iyomasa Mamie Mizusaki , Lopes Ruberval Armando , Watanabe Ii‐Sei
Published: May 2011

The fine structure of submandibular glands of mouse were analyzed using light microscopy (LM), high resolution scanning electron microscopy (HRSEM), and transmission electron microscopy (TEM) methods. For LM, the specimens were embedded in Spurr resin, stained by toluidin blue solutions. For TEM, the tissues of submandibular salivary glands were fixed with modified Karnovsky solution and postfixed with osmium tetroxide. For HRSEM, the tissues were fixed with 2% osmium tetroxide solution in 1/15M sodium phosphate buffer (pH 7.4). The samples were immersed successively in dymethylsulphoxide and freeze cracked. The maceration was made in diluted osmium tetroxide for 24–48 h. The samples were examined by high resolution scanning electron microscopy. The intracellular components of acinar and ductal cells revealed clearly the Golgi apparatus, rough endoplasmic reticulum, secretory granules, and mitochondria. The end bulbs of Golgi lamellae and flattened cisterns of rough endoplasmic reticulum showed the luminal surface. A few mitochondria were identified intermingling between the rough endoplasmic reticulum and the mitochondriales cristae in three‐dimensional HRSEM images. Secretory granules were numerous and presented different sizes. Small granules of ribosomes were attached on cistern surface, measuring 20–25 nm in diameter. Numerous arranged microvilli were found on the luminal surface of secretory canaliculus. The contact surfaces of acinar cells revealed complicated interdigitations by cytoplasmic processes. The mitochondria of duct cells were disposed vertically and surrounded by basal infoldings of plasma membranes. Basement membrane showed a spongy‐like structure having an irregular surface with various strands and meshes of fine collagen fibrils. Microsc. Res. Tech., 2011. © 2011 Wiley Periodicals, Inc.
3d surface profiling and high resolution imaging for refining the florin rings and epicuticular wax crystals of Pinus koraiensis needles
Authors: KIM Ki Woo , Lee Sang‐Tae , Bae Sang‐Won , KIM Pan‐Gi
Published: May 2011

3D surface profiling and high resolution imaging were performed to refine the Florin rings and epicuticular wax crystals of Pinus koraiensis needles. Needles were collected from four‐year‐old seedlings and air‐dried for surface observations. Field emission scanning electron microscopy revealed that stomata were found on the abaxial (lower) surface of needles. Measured as ca. 40 μm long, they were largely elliptical or oval‐shaped. Epicuticular wax crystals were present in the epistomatal chambers as well as on the surrounding epidermis. Rodlets were prevalently found on the stomatal bands and furrows as well as within the epistomatal chambers. The presence of wax tubules was ascertained by the distinct terminal openings at their ends. The occurrence of wax ridges was evident on the epidermis near the saw‐tooth margins (nonstomatal areas). No distinct wax ridges were detected on the dewaxed needles. Raised Florin rings were distinct on the stomata. White light scanning interferometry showed that the diameter and width of stomata were ca. 44.02 ± 3.33 μm and 32.10 ± 3.30 μm, respectively. Measured from the neighboring epidermis to the stomatal aperture, the mean height of the stoma reached ca. 6.23 ± 1.28 μm. Focus variation metrology allowed measuring the mean elevation angle of the stoma, reaching ca. 41.41 ± 11.25°. This is the first report on a novel approach to the establishment of quantitative criteria of Florin ring classification by nontactile 3D surface profiling beyond the previous qualitative descriptions of Florin rings of coniferous species. Microsc. Res. Tech., 2011. © 2011 Wiley Periodicals, Inc.
Galactosides in glycoconjugates of Xenopus laevis testis shown by lectin histochemistry
Authors: Valbuena Galder , Alonso Edurne , Madrid Juan Francisco , DíAz‐Flores Lucio , SáEz Francisco José
Published: May 2011

The implication of galactosides and other glycoconjugates on spermatogenesis has been previously reported. Glycans show such a complex structure that it makes them very difficult to analyze. Lectin histochemistry is a helpful tool for the study of glycan composition. Lectin histochemistry can be combined with deglycosylation pretreatments to explore the glycan type to which carbohydrates are linked. The aim of the present work was the localization of galactose (Gal)‐containing glycoconjugates in the testis of Xenopus laevis, a species widely used in cell, molecular and developmental biology. Gal specific lectins BPL, PNA, BSI‐B4, MAA‐I, and RCA‐I, were used in combination with deglycosylation procedures. Except for BPL, all the lectins were reactive for several testicular tissues. Some of the lectins showed a different reactivity depending on the stage of spermatogenic development, suggesting that cell glycoconjugates are modified during spermatogenesis. The surface of primary spermatocytes was strongly labeled with lectins from peanut (PNA) and castor bean (RCA‐I), which agrees with the presence of galactosyl‐glycolipids reported in the cell membrane of mammalian spermatocytes. The acrosome was unexpectedly negative to all the lectins tested, whereas the acrosome of mammals and other amphibians has shown a high expression of glycoconjugates, including galactosides. The results obtained after deglycosylation by β‐elimination or incubation with PNGase F, which respectively remove O‐ and N‐linked oligosaccharides, allowed us to elucidate the nature of the labeled glycans. The strong expression of galactosides at the cell surface of spermatocytes and spermatids suggests the involvement of these glycans in cell adhesion mechanisms during spermatogenesis. Microsc. Res. Tech., 2011. © 2011 Wiley‐Liss, Inc.
Improved method of preparation of supported planar lipid bilayers as artificial membranes for antigen presentation
Authors: Ma Zhengyu , Janmey Paul A. , Sharp Kim A. , Finkel Terri H.
Published: May 2011

T cell activation is the result of direct cell‐cell contact between T cells and antigen presenting cells (APCs), and of interactions between membrane‐bound ligands and receptors at the contact interface, the “immunological synapse.” Model APCs based upon supported fluid lipid bilayers have been used to dissect these complex molecular interactions and to facilitate real‐time microscopic observations. Nearly all studies have used liposome fusion‐based methods to make supported bilayers, and the biophysical properties of these membranes were not characterized in detail. Here, using both Langmuir‐Blodgett and liposome fusion techniques, we explored five different methods of lipid bilayer preparation on glass, mica, or dextran cushion substrates and characterized the stability, homogeneity, and fluidity of the bilayers with fluorescence microscopy and fluorescence recovery after photobleaching (FRAP). Most combinations of techniques and substrates led to unsatisfactory results, notably, a lack of homogeneity for liposome fusion on glass, low stability of bilayers on mica, and loss of fluidity of dextran‐cushioned bilayers in solutions containing protein. To overcome these deficits, we developed a technique that combines liposome fusion on glass and thermally enhanced bilayer expansion. The newly expanded pristine bilayer showed high degrees of stability, homogeneity, and fluidity. MHC and ICAM‐1 molecules anchored on the bilayer diffused freely and stimulated T cell calcium flux and adhesion, respectively. Microsc. Res. Tech., 2011. © 2011 Wiley Periodicals, Inc.
Ketamine effects on the urogenital system—changes in the urinary bladder and sperm motility
Authors: Tan Sijie , Chan W.M. , Wai Maria S.M. , Hui Lawrence K.K. , Hui Vivian W.K. , James Anthony E. , Yeung L.Y. , Yew D.T.
Published: May 2011

Different doses of ketamine (10 mg/kg, 20 mg/kg, 30 mg/kg, 40 mg/kg, 50 mg/kg, and 60 mg/kg) were injected i.p. (I.P.), respectively, to male ICR mice to determine the optimal dosage for chronic administration. At and above 40 mg/kg I.P. injection, mice had almost no hindlimb movement during swimming test. Subsequently, 30 mg/kg was used as the dose for the study in the toxicity of long‐term ketamine administration on urinary bladder and sperm motility. The treatment group were subdivided into two (n = 10 each group); one received daily ketamine treatment i.p. for 3 months and another group for 6 months. Corresponding number of mice in control groups (n = 5 each group) received saline injection instead of ketamine. Terminal dUTP nick and labeling (TUNEL) study and Sirius red staining were carried out on the sectioned slides of the urinary bladders to study the degree of apoptosis in both epithelium and muscular layers of the urinary bladder and the relative thickness of the muscular layers in this organ was also computed. Apoptosis in the bladder epithelium was observed initially in the 3‐month ketamine treated mice and the number of apoptotic cells was significantly different (P < 0.05) between the 3‐month and 6‐month ketamine treated mice and the control. The relative thickness of muscular layers in the bladder wall also decreased significantly (P < 0.05) when the 6‐month treated mice and the control were compared. Sirius red staining revealed increase of collagen in the urinary bladder of the treated mice, most evidently 6 months after ketamine treatment. In addition, the sperm motility was studied and there was a statistically significant difference between the control and ketamine treated groups in the percentages of sperms which were motile (P < 0.05). This suggested that the chronic administration of ketamine affected the genital system as well. Microsc. Res. Tech., 2011. © 2011 Wiley Periodicals, Inc.
Reactivity of ketene dithiolates toward alkyl bromides
Authors: Padmavathi Venkatapuram , Reddy Guda Dinneswara , Reddy Gali Sudhakar , Mahesh Konda , Padmaja Adivireddy
Published: May 2011

The reactivity of barbituric/thiobarbituric ketene dithiolates with bromoacetic ester and phenacyl bromide is studied. J. Heterocyclic Chem., (2011).
Friedländer synthesis of poly‐substituted quinolines in the presence of triethylammonium hydrogen sulfate [Et3NH][HSO4] as a highly efficient, and cost effective acidic ionic liquid catalyst
Authors: Kermani Esmat Tavakolinejad , Khabazzadeh Hojatollah , Jazinizadeh Tayebeh
Published: May 2011

A rapid and an efficient method for the preparation of a variety of substituted quinolines has been developed through the reactions of o‐aminoarylketones with carbonyl compounds containing a reactive α‐methylene moiety in the presence of molten [Et3NH][HSO4] under solvent‐free conditions in high yields. J. Heterocyclic Chem., (2011).
4‐(Azulen‐1‐yl) six‐membered heteroaromatics substituted with thiophen‐2‐yl or furan‐2‐yl moieties in 2 and 6 positions
Authors: Razus Alexandru C. , Birzan Liviu , Cristea Mihaela , Tecuceanu Victorita , Hanganu Anamaria , Enache Cristian
Published: May 2011

Pyranylium perchlorates with azulen‐1‐yl moiety in 4‐position and thiophen‐2‐yl or furan‐2‐yl in 2 and 6‐positions were obtained by the substitution of 4‐chloro corresponding salts with azulenes. The pyranylium salts are used as starting materials for the synthesis of pyridine and pyridinium salts. The products were characterized and for pyridines pKa was spectroscopically determined. Several attempts were made for pyridine complexation with metal cations as Hg2+ or Ag+. J. Heterocyclic Chem., (2011).
Microfinance services, poverty and artisanal mineworkers in Africa: In search of measures for empowering vulnerable groups
Authors: Spiegel Samuel J.
Published: May 2011

This article combines a review of the importance of artisanal mining to the livelihoods of poor and vulnerable rural populations in Africa with critical reflections on the scope for supporting such livelihoods through microfinance services. Drawing on interviews with mining communities, lending institutions and policymakers, the study examines constraints in accessing formal and informal financial services and argues for a more flexible, context‐specific and goal‐oriented institutional approach to supporting mineworkers. It gives particular attention to the potential roles of group lending and saving schemes adapted from the Grameen Bank model, public subsidies for credit and equipment hire purchase loans as components of an integrated programme of support and technical training. The cases examined illustrate why governments, international donors, private sector institutions and researchers should expand the discussion of microfinance objectives and services beyond conventional commercial approaches in order to explicitly address development concerns related to social marginalisation and capacity‐strengthening among vulnerable groups. Copyright © 2011 John Wiley & Sons, Ltd.
Human papillomavirus 16 variants from Zambian women with normal pap smears
Authors: Lei Yan Jun , Makhaola Kgomotso , Pittayakhajonwut Daraporn , Wood Charles , Angeletti Peter C.
Published: May 2011

Human papillomavirus (HPV) type 16 is the most prevalent high‐risk viral genotype associated with cervical cancer. Six distinct phylogenetic clusters of HPVs have been identified and are distributed differently across five continents. HPV16 DNA was extracted from cervico‐lavage samples from women with normal pap smears. The LCR regions were amplified in triplicate, cloned, sequenced, and analyzed from a total of 11 recovered HPV16 positive samples [Ng'andwe et al. (2007): BMC Infect Dis 7:77] were analyzed for sequence variation. The HPV16 LCR variants were assessed for promoter activity by use of a luciferase reporter gene. Six novel HPV16 variants with nucleotide exchanges in the LCR region were identified. Five clones were classified as European group HPV16 variants and one as an African group variant. Two of these variants had relatively lower promoter activity, 30% of that of the wild‐type strain. The decreased promoter activity of some HPV16 variants may decrease expression of viral oncogenes and may be linked with the development, phenotype and severity of the cervical lesions in women infected with these across HPV16 variants. J. Med. Virol. 83:1230–1237, 2011. © 2011 Wiley‐Liss, Inc.
Detection of G3P[3] and G3P[9] rotavirus strains in American Indian children with evidence of gene reassortment between human and animal rotaviruses
Authors: Grant Lindsay , Esona Mathew , Gentsch Jon , Watt James , Reid Raymond , Weatherholtz Robert , Santosham Mathuram , Parashar Umesh , O'Brien Katherine
Published: May 2011

The distribution and evolution of human rotavirus strains is important for vaccine development and effectiveness. In settings where rotavirus vaccine coverage is high, vaccine pressure could select for replacement of common strains (similar to those included in rotavirus vaccines) with uncommon strains, some of which could be generated by reassortment between human and animal rotaviruses. Between 2002 and 2004, a phase‐III rotavirus vaccine clinical trial was conducted among American Indian children of the Navajo and White Mountain Apache tribes, which are known to be at high risk for rotavirus diarrhea. We evaluated the rotavirus strains collected from study participants who received placebo during the trial to determine the distribution of rotavirus genotypes and to detect emerging strains that contribute to disease and could influence rotavirus vaccine effectiveness. Three uncommon strains of human rotavirus, two G3P[3] and one G3P[9] strains were detected in stools of children aged 3 to 6 months of age. Segments of all 11 rotavirus genes were sequenced and genotyped by comparison of cognate gene fragments with reference strains. The G3P[3] strains had similar genotypes to each other and to reference dog and cat strains. The G3P[9] strain had similar genotypes to cow, cat and dog reference strains. Genetic analyses of these three strains support the known diversity generating mechanisms of rotavirus. J. Med. Virol. 83:1288–1299, 2011. © 2011 Wiley‐Liss, Inc.
Chemokine receptor expression on dendritic cells is normal in HIV‐infected patients with a stable response to art, but chemokine levels remain elevated
Authors: Lee Silvia , Fernandez Sonia , French Martyn , Price Patricia
Published: May 2011

The development of strategies to optimize T‐cell responses in previously immunodeficient HIV patients with a stable virological response to ART requires an understanding of the factors that affect responsiveness. Chemokines direct the migration of dendritic cells (DC) to non‐lymphoid tissues infected by secondary pathogens and to lymph nodes where they prime T‐cells. Quantitation of mRNA is a sensitive technique enabling assessment of chemokine receptors by CD14+ monocytes, myeloid (m)DCs, plasmacytoid (p)DCs, and M‐DC8+ cells. MDC8+ cells invariably expressed less CCR2, CCR5, and CXCR4 than the other cells, but expression of CCR2, CCR5, CCR6, CCR7, CXCR3, and CXCR4 was similar in patients and healthy controls. However plasma levels of CXCL10, CCL5, and CCL2 remained higher in patients than controls. Overall, it appears that chemokine directed migration of DC may not limit immune responses in these patients. J. Med. Virol. 83:1128–1133, 2011. © 2011 Wiley‐Liss, Inc.