bluuebunny/crossref_metadata_2025 huggingface dataset:
PNPLA3 is regulated by glucose in human hepatocytes, and its I148M mutant slows down triglyceride hydrolysis
Authors: Perttilä Julia , Huaman-Samanez Carolina , Caron Sandrine , Tanhuanpää Kimmo , Staels Bart , Yki-Järvinen Hannele , Olkkonen Vesa M.
Published: February 2012

Liver fat is increased in carriers of the minor G allele in rs738409 (I148M amino acid substitution) in patatin-like phospholipase domain-containing 3 (PNPLA3)/adiponutrin. We studied transcriptional regulation of PNPLA3 in immortalized human hepatocytes (IHH) and human hepatoma cells (HuH7) and the impact of PNPLA3 I148M mutant on hepatocyte triglyceride metabolism. Studies in IHH showed that silencing of the carbohydrate response element-binding protein (ChREBP) abolished induction of PNPLA3 mRNA by glucose. Glucose-dependent binding of ChREBP to a newly identified carbohydrate response element in the PNPLA3 promoter was demonstrated by chromatin immunoprecipitation. Adenoviral overexpression of mouse ChREBP in IHH failed to induce PNPLA3 mRNA. [3H]acetate or [3H]oleate incorporation with 1-h pulse labeling or 18-h [3H]oleate labeling in HuH7 cells showed no effect of PNPLA3 I148M on triglyceride (TG) synthesis in the absence of free fatty acid (FFA) loading. Increased [3H]oleate accumulation into triglycerides in I148M-expressing cells was observed after 18 h of labeling in the presence of 200 μM FFA-albumin complexes. This was accompanied by increased PNPLA3 protein levels. The rate of hydrolysis of [3H]TG during lipid depletion was decreased significantly by PNPLA3 I148M. Our results suggest that PNPLA3 is regulated in human hepatocytes by glucose via ChREBP. PNPLA3 I148M enhances cellular accumulation of [3H]TG in the presence of excess FFA, which is known to stabilize PNPLA3 protein. These data do not exclude an effect of PNPLA3 I148M on hepatocyte lipogenesis but show that the mutant increases the stability of triglycerides.
Short-term regional meal fat storage in nonobese humans is not a predictor of long-term regional fat gain
Authors: Votruba Susanne B. , Jensen Michael D.
Published: February 2012

Although body fat distribution strongly predicts metabolic health outcomes related to excess weight, little is known about the factors an individual might exhibit that predict a particular fat distribution pattern. We utilized the meal fatty acid tracer-adipose biopsy technique to assess upper and lower body subcutaneous (UBSQ and LBSQ, respectively) meal fat storage in lean volunteers who then were overfed to gain weight. Meal fatty acid storage in UBSQ and LBSQ adipose tissue, as well as daytime substrate oxidation (indirect calorimetry), was measured in 28 nonobese volunteers [ n = 15 men, body mass index = 22.1 ± 2.5 (SD)] before and after an ∼8-wk period of supervised overfeeding (weight gain = 4.6 ± 2.2 kg, fat gain = 3.8 ± 1.7 kg). Meal fat storage (mg/g adipose tissue lipid) in UBSQ ( visit 1: 0.78 ± 0.34 and 1.04 ± 0.71 for women and men, respectively, P = 0.22; visit 2: 0.71 ± 0.24 and 0.90 ± 0.37 for women and men, respectively, P = 0.08) and LBSQ ( visit 1: 0.60 ± 0.23 and 0.48 ± 0.29 for women and men, respectively, P = 0.25; visit 2: 0.62 ± 0.24 and 0.65 ± 0.23 for women and men, respectively, P = 0.67) adipose tissue did not differ between men and women at either visit. Fractional meal fatty acid storage in UBSQ (0.31 ± 0.15) or LBSQ (0.19 ± 0.13) adipose tissue at visit 1 did not predict the percent change in regional body fat in response to overfeeding. These data indicate that meal fat uptake trafficking in the short term (24 h) is not predictive of body fat distribution patterns. In general, UBSQ adipose tissue appears to be a favored depot for meal fat deposition in both sexes, and redistribution of meal fatty acids likely takes place at later time periods.
Bed rest impairs skeletal muscle amino acid transporter expression, mTORC1 signaling, and protein synthesis in response to essential amino acids in older adults
Authors: Drummond Micah J. , Dickinson Jared M. , Fry Christopher S. , Walker Dillon K. , Gundermann David M. , Reidy Paul T. , Timmerman Kyle L. , Markofski Melissa M. , Paddon-Jones Douglas , Rasmussen Blake B. , Volpi Elena
Published: February 2012

Skeletal muscle atrophy during bed rest is attributed, at least in part, to slower basal muscle protein synthesis (MPS). Essential amino acids (EAA) stimulate mammalian target of rapamycin (mTORC1) signaling, amino acid transporter expression, and MPS and are necessary for muscle mass maintenance, but there are no data on the effect of inactivity on this anabolic mechanism. We hypothesized that bed rest decreases muscle mass in older adults by blunting the EAA stimulation of MPS through reduced mTORC1 signaling and amino acid transporter expression in older adults. Six healthy older adults (67 ± 2 yr) participated in a 7-day bed rest study. We used stable isotope tracers, Western blotting, and real-time qPCR to determine the effect of bed rest on MPS, muscle mTORC1 signaling, and amino acid transporter expression and content in the postabsorptive state and after acute EAA ingestion. Bed rest decreased leg lean mass by ∼4% ( P < 0.05) and increased postabsorptive mTOR protein ( P < 0.05) levels while postabsorptive MPS was unchanged ( P > 0.05). Before bed rest acute EAA ingestion increased MPS, mTOR (Ser2448), S6 kinase 1 (Thr389, Thr421/Ser424), and ribosomal protein S6 (Ser240/244) phosphorylation, activating transcription factor 4, L-type amino acid transporter 1 and sodium-coupled amino acid transporter 2 protein content ( P < 0.05). However, bed rest blunted the EAA-induced increase in MPS, mTORC1 signaling, and amino acid transporter protein content. We conclude that bed rest in older adults significantly attenuated the EAA-induced increase in MPS with a mechanism involving reduced mTORC1 signaling and amino acid transporter protein content. Together, our data suggest that a blunted EAA stimulation of MPS may contribute to muscle loss with inactivity in older persons.
Targeted overexpression of OGFr in epithelium of transgenic mice suppresses cell proliferation and impairs full-thickness wound closure
Authors: McLaughlin Patricia J. , Keiper Cara L. , Verderame Michael F. , Zagon Ian S.
Published: February 2012

The opioid growth factor (OGF) and its receptor, OGFr, play a regulatory role in cell proliferation, and maintain homeostasis through a tonically active negative feedback mechanism. To directly evaluate the repercussion of increased OGFr expression and consequent gain-of-function in epithelium, bovine keratin 5 promoter elements were used to direct the expression of OGFr to skin in a tetracycline-regulated manner. Three founder lines overexpressing OGFr (OGFrTG/K5-tTA) were established. Evidence for increased OGFr in the epithelium included a three-fold increase in OGFr binding activity, as well as significant increases in OGFr protein, as monitored by semiquantitative immunohistochemistry. DNA synthesis in target epithelium, including cornea, tongue, and skin of transgenic mice was decreased 41% to 80% from wild-type littermates; the liver, a nonepithelial organ, was not altered. Decreased DNA synthesis in corneal epithelium induced by transgenic expression of OGFr was further reduced by treatment with exogenous OGF but reversed by exposure to the opioid antagonist, naloxone. The number of cell layers in both epidermis and cornea of OGFrTG/K5-tTA animals was reduced nearly 45% from wild-type mice. Full-thickness wounds in mice overexpressing OGFr healed 37% to 75% slower than wild-type littermates. These data demonstrate for the first time that stable genetic amplification of OGFr downregulates homeostatic cell proliferation, as well as pathophysiological processes with respect to wound repair. These mice also can serve as a valuable model to dissect the mechanism of OGF-OGFr action and may be important in understanding the etiology, pathogenesis, and treatment of epithelium-related diseases.
Reduced Klotho expression level in kidney aggravates renal interstitial fibrosis
Authors: Sugiura Hidekazu , Yoshida Takumi , Shiohira Shunji , Kohei Junko , Mitobe Michihiro , Kurosu Hiroshi , Kuro-o Makoto , Nitta Kosaku , Tsuchiya Ken
Published: February 2012

Renal expression of the klotho gene is markedly suppressed in chronic kidney disease (CKD). Since renal fibrosis is the final common pathology of CKD, we tested whether decreased Klotho expression is a cause and/or a result of renal fibrosis in mice and cultured renal cell lines. We induced renal fibrosis by unilateral ureteral obstruction (UUO) in mice with reduced Klotho expression ( kl/+ mice) and compared them with wild-type mice. The UUO kidneys from kl/+ mice expressed significantly higher levels of fibrosis markers such as α-smooth muscle actin (α-SMA), fibronectin, and transforming growth factor-β1(TGF-β1) than those from wild-type mice. In addition, in cultured renal fibroblast cells (NRK49F), the levels of α-SMA and PAI1 expression were significantly suppressed by addition of recombinant Klotho protein to the medium. The similar effects were observed by a TGF-β1receptor inhibitor (ALK5 inhibitor). These observations suggest that low renal Klotho expression enhances TGF-β1activity and is a cause of renal fibrosis. On the other hand, TGF-β1reduced Klotho expression in renal cultured epithelial cells (inner medullary collecting duct and human renal proximal tubular epithelium), suggesting that low renal Klotho expression is a result of renal fibrosis. Taken together, renal fibrosis can trigger a deterioration spiral of Klotho expression, which may be involved in the pathophysiology of CKD progression.
Ginkgolide B inhibits renal cyst development in in vitro and in vivo cyst models
Authors: Zhou Hong , Gao Jinsheng , Zhou Li , Li Xin , Li Weidong , Li Xuejun , Xia Yin , Yang Baoxue
Published: February 2012

Autosomal dominant polycystic kidney disease (ADPKD) is a common inherited disease characterized by massive enlargement of fluid-filled cysts in the kidney. However, there is no effective therapy yet for this disease. To examine whether ginkgolide B, a natural compound, inhibits cyst development, a Madin-Darby canine kidney (MDCK) cyst model, an embryonic kidney cyst model, and a PKD mouse model were used. Interestingly, ginkgolide B significantly inhibited MDCK cyst formation dose dependently, with up to 69% reduction by 2 μM ginkgolide B. Ginkgolide B also significantly inhibited cyst enlargement in the MDCK cyst model, embryonic kidney cyst model, and PKD mouse model. To determine the underlying mechanisms, the effect of ginkgolide B on MDCK cell viability, proliferation, apoptosis, chloride transporter CFTR activity, and intracellular signaling pathways were also studied. Ginkgolide B did not affect cell viability, proliferation, and expression and activity of the chloride transporter CFTR that mediates cyst fluid secretion. Ginkgolide B induced cyst cell differentiation and altered the Ras/MAPK signaling pathway. Taken together, our results demonstrate that ginkgolide B inhibits renal cyst formation and enlargement, suggesting that ginkgolide B might be developed into a novel candidate drug for ADPKD.
Nicorandil as a novel therapy for advanced diabetic nephropathy in the eNOS-deficient mouse
Authors: Tanabe Katsuyuki , Lanaspa Miguel A. , Kitagawa Wataru , Rivard Christopher J. , Miyazaki Makoto , Klawitter Jelena , Schreiner George F. , Saleem Moin A. , Mathieson Peter W. , Makino Hirofumi , Johnson Richard J. , Nakagawa Takahiko
Published: February 2012

Nicorandil is an orally available drug that can act as a nitric oxide donor, an antioxidant, and an ATP-dependent K channel activator. We hypothesized that it may have a beneficial role in treating diabetic nephropathy. We administered nicorandil to a model of advanced diabetic nephropathy (the streptozotocin-induced diabetes in mice lacking endothelial nitric oxide synthase, eNOSKO); controls included diabetic eNOS KO mice without nicorandil and nondiabetic eNOS KO mice treated with either nicorandil or vehicle. Mice were treated for 8 wk. Histology, blood pressure, and renal function were determined. Additional studies involved examining the effects of nicorandil on cultured human podocytes. Here, we found that nicorandil did not affect blood glucose levels, blood pressure, or systemic endothelial function, but significantly reduced proteinuria and glomerular injury (mesangiolysis and glomerulosclerosis). Nicorandil protected against podocyte loss and podocyte oxidative stress. Studies in cultured podocytes showed that nicorandil likely protects against glucose-mediated oxidant stress via the ATP-dependent K channel as opposed to its NO-stimulating effects. In conclusion, nicorandil may be beneficial in diabetic nephropathy by preserving podocyte function. We recommend clinical trials to determine whether nicorandil may benefit diabetic nephropathy or other conditions associated with podocyte dysfunction.
β2-Adrenergic receptor supports prolonged theta tetanus-induced LTP
Authors: Qian Hai , Matt Lucas , Zhang Mingxu , Nguyen Minh , Patriarchi Tommaso , Koval Olha M. , Anderson Mark E. , He Kaiwen , Lee Hey-Kyoung , Hell Johannes W.
Published: February 2012

The widespread noradrenergic innervation in the brain promotes arousal and learning by molecular mechanisms that remain largely undefined. Recent work shows that the β2-adrenergic receptor (β2AR) is linked to the AMPA-type glutamate receptor subunit GluA1 via stargazin and PSD-95 (Joiner ML, Lise MF, Yuen EY, Kam AY, Zhang M, Hall DD, Malik ZA, Qian H, Chen Y, Ulrich JD, Burette AC, Weinberg RJ, Law PY, El-Husseini A, Yan Z, Hell JW. EMBO J 29: 482–495, 2010). We now demonstrate that the β2AR plays a prominent role in long-term potentiation (LTP) induced by a train of 900 stimuli at 5 Hz (prolonged theta-tetanus-LTP, or PTT-LTP) in the hippocampal CA1 region in mice, which requires simultaneous β-adrenergic stimulation. Although PTT-LTP was impaired in hippocampal slices from β1AR and β2AR knockout (KO) mice, only β2AR-selective stimulation with salbutamol supported this PTT-LTP in wild-type (WT) slices, whereas β1AR-selective stimulation with dobutamine (+ prazosin) did not. Furthermore, only the β2AR-selective antagonist ICI-118551 and not the β1AR-selective antagonist CGP-20712 inhibited PTT-LTP and phosphorylation of GluA1 on its PKA site S845 in WT slices. Our analysis of S845A knockin (KI) mice indicates that this phosphorylation is relevant for PTT-LTP. These results identify the β2AR-S845 signaling pathway as a prominent regulator of synaptic plasticity.
Developmental regulation of membrane excitability in rat spinal lamina I projection neurons
Authors: Li Jie , Baccei Mark L.
Published: February 2012

It is now universally recognized that neonates can experience considerable pain. While spinal lamina I neurons projecting to the brain contribute to the generation of hyperalgesia, nothing is known about their electrophysiological properties during early life. Here we have used in vitro whole cell patch-clamp recordings in rat spinal cord slices to determine whether the intrinsic membrane properties of lamina I projection neurons, as well as their synaptic inputs, are developmentally regulated during the early postnatal period. Projection neurons were identified via retrograde transport of DiI injected into the parabrachial nucleus (PB) or periaqueductal gray (PAG) and characterized at postnatal days (P)2–5, P10–12, P19–23, and P30–32. Both spino-PB and spino-PAG neurons demonstrated an age-dependent reduction in spike threshold and duration at room temperature, which was accompanied by a developmental increase in the frequency of miniature excitatory and inhibitory postsynaptic currents. Notably, in both groups, age-dependent changes in the passive membrane properties or rheobase only occurred after the third postnatal week. However, spontaneous activity was significantly more prevalent within the developing spino-PB population and was dominated by an irregular pattern of discharge. In addition, while the instantaneous firing frequency remained unaltered in spino-PB neurons during the first weeks of life, spino-PAG cells fired at a higher rate at P19–23 compared with younger groups, suggesting that the gain of parallel ascending nociceptive pathways may be independently regulated during development. Overall, these results demonstrate that intrinsic membrane excitability is modulated in a cell type-specific manner within developing spinal nociceptive circuits.
Dark-adapted response threshold of OFF ganglion cells is not set by OFF bipolar cells in the mouse retina
Authors: Arman A. Cyrus , Sampath Alapakkam P.
Published: February 2012

The nervous system frequently integrates parallel streams of information to encode a broad range of stimulus strengths. In mammalian retina it is generally believed that signals generated by rod and cone photoreceptors converge onto cone bipolar cells prior to reaching the retinal output, the ganglion cells. Near absolute visual threshold a specialized mammalian retinal circuit, the rod bipolar pathway, pools signals from many rods and converges on depolarizing (AII) amacrine cells. However, whether subsequent signal flow to OFF ganglion cells requires OFF cone bipolar cells near visual threshold remains unclear. Glycinergic synapses between AII amacrine cells and OFF cone bipolar cells are believed to relay subsequently rod-driven signals to OFF ganglion cells. However, AII amacrine cells also make glycinergic synapses directly with OFF ganglion cells. To determine the route for signal flow near visual threshold, we measured the effect of the glycine receptor antagonist strychnine on response threshold in fully dark-adapted retinal cells. As shown previously, we found that response threshold for OFF ganglion cells was elevated by strychnine. Surprisingly, strychnine did not elevate response threshold in any subclass of OFF cone bipolar cell. Instead, in every OFF cone bipolar subclass strychnine suppressed tonic glycinergic inhibition without altering response threshold. Consistent with this lack of influence of strychnine, we found that the dominant input to OFF cone bipolar cells in darkness was excitatory and the response threshold of the excitatory input varied by subclass. Thus, in the dark-adapted mouse retina, the high absolute sensitivity of OFF ganglion cells cannot be explained by signal transmission through OFF cone bipolar cells.
From Citizen Science to Policy Development on the Coral Reefs of Jamaica
Authors: Crabbe M. James C.
Published: February 2012

This paper explores the application of citizen science to help generation of scientific data and capacity-building, and so underpin scientific ideas and policy development in the area of coral reef management, on the coral reefs of Jamaica. From 2000 to 2008, ninety Earthwatch volunteers were trained in coral reef data acquisition and analysis and made over 6,000 measurements on fringing reef sites along the north coast of Jamaica. Their work showed that while recruitment of small corals is returning after the major bleaching event of 2005, larger corals are not necessarily so resilient and so need careful management if the reefs are to survive such major extreme events. These findings were used in the development of an action plan for Jamaican coral reefs, presented to the Jamaican National Environmental Protection Agency. It was agreed that a number of themes and tactics need to be implemented in order to facilitate coral reef conservation in the Caribbean. The use of volunteers and citizen scientists from both developed and developing countries can help in forging links which can assist in data collection and analysis and, ultimately, in ecosystem management and policy development.
Sex- and Age-Related Differences in Bone Microarchitecture in Men Relative to Women Assessed by High-Resolution Peripheral Quantitative Computed Tomography
Authors: Amin Shreyasee , Khosla Sundeep
Published: February 2012

The trabecular and cortical compartments of bone each contributes to bone strength. Until recently, assessment of trabecular and cortical microstructure has required a bone biopsy. Now, trabecular and cortical microstructure of peripheral bone sites can be determined noninvasively using high-resolution peripheral quantitative computed tomography (HR-pQCT). Studies that have used HR-pQCT to evaluate cohorts of both men and women have provided novel insights into the changes in bone microarchitecture that occur with age between the sexes, which may help to explain the lower fracture incidence in older men relative to women. This review will highlight observations from these studies on both the sex- and age-related differences in trabecular and cortical microstructure that may underlie the differences in bone strength, and thereby fracture risk, between men and women.
Fertility Preservation in Girls
Authors: Michaeli Jennia , Weintraub Michael , Gross Eitan , Ginosar Yehuda , Ravitsky Vardit , Eizenman Einat , Mitrani Eduardo , Lebovich Meital , Laufer Neri , Kennedy Stephen , Revel Ariel
Published: February 2012

Children that undergo treatment for cancer are at risk of suffering from subfertility or hormonal dysfunction due to the detrimental effects of radiotherapy and chemotherapeutic agents on the gonads. Cryopreservation of ovarian tissue prior to treatment offers the possibility of restoring gonadal function after resumption of therapy. Effective counseling and management of pediatric patients is crucial for preserving their future reproductive potential. The purpose of this article is to review recent literature and to revise recommendations we made in a 2007 article. Pediatric hemato-oncology, reproductive endocrinology, surgery, anesthesia and bioethics perspectives are discussed and integrated to propose guidelines for offering ovarian cryopreservation to premenarcheal girls with cancer.
Marrow Stromal Cell Infusion Rescues Hematopoiesis in Lethally Irradiated Mice despite Rapid Clearance after Infusion
Authors: Yang Xiaodong , Balakrishnan Ilango , Torok-Storb Beverly , Pillai Manoj M.
Published: February 2012

Marrow stromal cells (MSCs, also termed mesenchymal stem cells) have been proposed as a promising cellular therapy for tissue injury including radiation-induced marrow failure, but evidence for a direct effect is lacking. To assess the effects of MSCs on survival after lethal irradiation, we infused syngeneic MSCs (either as immortalized MSCs clones or primary MSCs) intravenously into wild-type C57/Bl6 mice within 24 hours of lethal total body irradiation (TBI). Mice receiving either of the MSC preparations had significantly improved survival when compared to controls. In vivo imaging, immune histochemistry, and RT-PCR employed to detect MSCs indicated that the infused MSCs were predominantly localized to the lungs and rapidly cleared following infusion. Our results suggest that a single infusion of MSCs can improve survival after otherwise lethal TBI but the effect is not due to a direct interaction with, or contribution to, the damaged marrow by MSCs.
The Existence of Fixed Points for Nonlinear Contractive Maps in Metric Spaces with w‐Distances
Authors: Lakzian Hossein , Lin Ing-Jer
Published: February 2012

Some fixed point theorems for (φ, ψ, p)‐contractive maps and (φ, k, p)‐contractive maps on a complete metric space are proved. Presented fixed point theorems generalize many results existing in the literature.
The “Natural” History of Medically Treated Temporal Lobe Epilepsy: What Can an Evidence-Based Approach Tell Us?
Authors: Josephson Colin Bruce , Pohlmann-Eden Bernhard
Published: February 2012

We systematically reviewed the literature to describe the “natural” history of medically treated temporal lobe epilepsy (TLE). No population-based studies recruiting incident cases of TLE irrespective of age exist. Prospective, population-based studies were limited to those recruiting only childhood-onset TLE or those reporting TLE as a subgroup of cohorts of focal epilepsies. Few studies have been performed in the “MRI era” limiting information on natural history secondary to specific pathologies. Available data suggests that TLE is highly variable, with unpredictable transient remissions and low rates of seizure freedom (30 to 50%). Etiology and failure of first and second drug seem to be the most important predictors for treatment prognosis. The role of initial precipitating injuries remains speculative, as imaging information of related events is either missing or conflicting. Prospective cohorts of new-onset TLE with long-term followup using advanced MRI techniques, timely EEG recordings, and assessments of psychiatric comorbidities are needed.
Systematic Review of Chinese Herbal Medicines for Preventing in-Stent Coronary Restenosis after Percutaneous Coronary Intervention
Authors: Zheng Guo-Hua , Liu Jian-Ping , Wang Nissi S. , Chen Hai-Ying , Chu Jian-Feng
Published: February 2012

Percutaneous coronary intervention (PCI) with stent placement is a standard treatment for coronary artery disease (CAD). In-stent restenosis after PCI remains a challenging clinical problem. In China, Chinese herbal medicines (CHMs) are widely used for preventing restenosis. This paper systematically reviewed the literature on the effectiveness and safety of CHMs in preventing restenosis after PCI in patients with CAD. Electronic databases were searched for randomized controlled trials that compared CHMs plus RWM with the same RWM plus placebo in preventing restenosis after PCI. A total of 52 trials (4905 patients) on 34 CHMs met the inclusion criteria and were analyzed. Ten trials had low risk of bias. Methodological quality of included trials was generally poor. Meta-analysis showed that at the end of at least 3 months’ followup, CHMs plus RWM could significantly reduce restenosis rate, cardiac mortality, recurrence rate of angina, acute myocardial infarction, numbers of repeat PCI, and numbers of coronary artery bypass graft. Reported adverse events included gastrointestinal upset, granulocytopenia, and increased alanine transaminase (ALT). CHMs may help prevent restenosis, thus reducing cardiac mortality after PCI. Caution should be exercised in drawing a definitive conclusion due to the poor methodological quality of the trials reviewed.
Nonlinear Model of Pseudoelastic Shape Memory Alloy Damper Considering Residual Martensite Strain Effect
Authors: Parulekar Y. M. , Reddy G. R.
Published: February 2012

Recently, there has been increasing interest in using superelastic shape memory alloys for applications in seismic resistant-design. Shape memory alloys (SMAs) have a unique property by which they can recover their original shape after experiencing large strains up to 8% either by heating (shape memory effect) or removing stress (pseudoelastic effect). Many simplified shape memory alloy models are suggested in the past literature for capturing the pseudoelastic response of SMAs in passive vibration control of structures. Most of these models do not consider the cyclic effects of SMA's and resulting residual martensite deformation. Therefore, a suitable constitutive model of shape memory alloy damper which represents the nonlinear hysterical dynamic system appropriately is essential. In this paper a multilinear hysteretic model incorporating residual martensite strain effect of pseudoelastic shape memory alloy damper is developed and experimentally validated using SMA wire, based damper device. A sensitivity analysis is done using the proposed model along with three other simplified SMA models. The models are implemented on a steel frame representing an SDOF system and the comparison of seismic response of structure with all the models is made in the numerical study.
Isolation Improvement of a Microstrip Patch Array Antenna for WCDMA Indoor Repeater Applications
Authors: Lee Hongmin , Park Jinwon
Published: February 2012

This paper presents the isolation improvement techniques of a microstrip patch array antenna for the indoor wideband code division multiple access (WCDMA) repeater applications. One approach is to construct the single-feed switchable feed network structure with an MS/NRI coupled-line coupler in order to reduce the mutual coupling level between antennas. Another approach is to insert the soft surface unit cells near the edges of the microstrip patch elements in order to reduce backward radiation waves. In order to further improve the isolation level, the server antenna and donor antenna are installedinorthogonal direction. The fabricated antenna exhibits a gain over 7 dBi and higher isolation level between server and donor antennas below −70 dB at WCDMA band.
Generalized Derivations in Semiprime Gamma Rings
Authors: Dey Kalyan Kumar , Paul Akhil Chandra , Rakhimov Isamiddin S.
Published: February 2012

LetMbe a 2-torsion-free semiprimeΓ-ring satisfying the conditionaαbβc=aβbαcfor alla,b,c∈M,  α,β∈Γ, and letD:M→Mbe an additive mapping such thatD(xαx)=D(x)αx+xαd(x)for allx∈M,  α∈Γand for some derivationdofM. We prove thatDis a generalized derivation.
Rumination as a Mediator of Chronic Stress Effects on Hypertension: A Causal Model
Authors: Gerin William , Zawadzki Matthew J. , Brosschot Jos F. , Thayer Julian F. , Christenfeld Nicholas J. S. , Campbell Tavis S. , Smyth Joshua M.
Published: February 2012

Chronic stress has been linked to hypertension, but the underlying mechanisms remain poorly specified. We suggest that chronic stress poses a risk for hypertension through repeated occurrence of acute stressors (often stemming from the chronic stress context) that cause activation of stress-mediating physiological systems. Previous models have often focused on the magnitude of the acute physiological response as a risk factor; we attempt to extend this to address the issue ofduration of exposure. Key to our model is the notion that these acute stressors can emerge not only in response to stressors present in the environment, but also to mental representations of those (or other) stressors. Consequently, although the experience of any given stressor may be brief, a stressor often results in a constellation of negative cognitions and emotions that form a mental representation of the stressor. Ruminating about this mental representation of the stressful event can cause autonomic activation similar to that observed in response to the original incident, and may occur and persist long after the event itself has ended. Thus, rumination helps explain how chronic stress causes repeated (acute) activation of one’s stress-mediating physiological systems, the effects of which accumulate over time, resulting in hypertension risk.
An Experimental Model for Resistance Exercise in Rodents
Authors: Nicastro Humberto , Zanchi Nelo Eidy , da Luz Claudia Ribeiro , Chaves Daniela Fojo Seixas , Lancha Antonio Herbert
Published: February 2012

This study aimed to develop an equipment and system of resistance exercise (RE), based on squat-type exercise for rodents, with control of training variables. We developed an operant conditioning system composed of sound, light and feeding devices that allowed optimized RE performance by the animal. With this system, it is not necessary to impose fasting or electric shock for the animal to perform the task proposed (muscle contraction). Furthermore, it is possible to perform muscle function testsin vivowithin the context of the exercise proposed and control variables such as intensity, volume (sets and repetitions), and exercise session length, rest interval between sets and repetitions, and concentric strength. Based on the experiments conducted, we demonstrated that the model proposed is able to perform more specific control of other RE variables, especially rest interval between sets and repetitions, and encourages the animal to exercise through short-term energy restriction and “disturbing” stimulus that do not promote alterations in body weight. Therefore, despite experimental limitations, we believe that this RE apparatus is closer to the physiological context observed in humans.
Monotonic Positive Solutions of Nonlocal Boundary Value Problems for a Second‐Order Functional Differential Equation
Authors: El-Sayed A. M. A. , Hamdallah E. M. , El-kadeky Kh. W.
Published: February 2012

We study the existence of at least one monotonic positive solution for the nonlocal boundary value problem of the second‐order functional differential equation x′′(t) = f(t, x(ϕ(t))), t ∈ (0,1), with the nonlocal condition , , where τk ∈ (a, d)⊂(0,1), ηj ∈ (c, e)⊂(0,1), and x0, x1 > 0. As an application the integral and the nonlocal conditions , x′(0) + x(e) − x(c) = x1 will be considered.
A Generalization of Ćirić Quasicontractions
Authors: Karapınar Erdal , Chi Kieu Phuong , Thanh Tran Duc
Published: February 2012

We proved a fixed point theorem for a class of maps that satisfy Ćirić′s contractive condition dependent on another function. We presented an example to show that our result is a real generalization.
Case Report: Recognizing Pneumatosis Intestinalis: A Case of Bowel Ischemia Presenting as Renal Colic
Authors: Corr Peter D.
Published: February 2012

The clinical diagnosis of bowel ischemia is often difficult and the diagnosis can easily be missed unless there is a high index of clinical and radiological suspicion. Bowel ischemia and or infarction must be considered in the differential diagnosis in the older patient with pre-existing coronary artery or generalized vascular disease, cardiac failure, or arrhythmias especially atrial fibrillation and hypertension. An elderly patient with caecal infarction is presented who was initially diagnosed and treated for renal colic.
Antiprotozoal and Antimycobacterial Activities of Pure Compounds fromAristolochia elegansRhizomes
Authors: Jiménez-Arellanes Adelina , León-Díaz Rosalba , Meckes Mariana , Tapia Amparo , Molina-Salinas Gloria María , Luna-Herrera Julieta , Yépez-Mulia Lilián
Published: February 2012

We analyzed the antimycobacterial activity of the hexane extract of rhizomes fromAristolochia elegans. Some compounds of this extract were purified and tested against a group of drug-resistantMycobacterium tuberculosisstrains. We also evaluated their antiprotozoal activities. The hexane extract was active againstM. tuberculosisH37Rv at aMIC=100 μg mL−1; the pure compounds eupomatenoid-1, fargesin, and (8R,8′R,9R)-cubebin were active againstM. tuberculosisH37Rv (MIC = 50 μg mL−1), while fargesin presented activity against three monoresistant strains ofM. tuberculosisH37Rv and a MDR clinical isolate ofM. tuberculosis(MIC<50 μg mL-1). Both the extract and eupomatenoid-1 were very active againstE. histolyticaandG. lamblia(IC50<0.624 μg mL-1); in contrast, fargesin and (8R,8′R,9R)-cubebin were moderately active (IC50<275 μg mL-1). In this context, two compounds responsible for the antimycobacterial presented byA. elegansare fargesin and cubebin, although others may exert this activity also. In addition to the antimycobacterial activity, the hexane extract has important activity againstE. histolyticaandG. lamblia, and eupomatenoid-1 is one of the compounds responsible for the antiparasite activity.
Propeller‐Shaped ZnO Nanostructures Obtained by Chemical Vapor Deposition: Photoluminescence and Photocatalytic Properties
Authors: Wang S. L. , Zhu H. W. , Tang W. H. , Li P. G.
Published: February 2012

Propeller‐shaped and flower‐shaped ZnO nanostructures on Si substrates were prepared by a one‐step chemical vapor deposition technique. The propeller‐shaped ZnO nanostructure consists of a set of axial nanorod (50 nm in tip, 80 nm in root and 1 μm in length), surrounded by radial‐oriented nanoribbons (20–30 nm in thickness and 1.5 μm in length). The morphology of flower‐shaped ZnO nanostructure is similar to that of propeller‐shaped ZnO, except the shape of leaves. These nanorods leaves (30 nm in diameter and 1–1.5 μm in length) are aligned in a radial way and pointed toward a common center. The flower‐shaped ZnO nanostructures show sharper and stronger UV emission at 378 nm than the propeller‐shaped ZnO, indicating a better crystal quality and fewer structural defects in flower‐shaped ZnO. In comparison with flower‐shaped ZnO nanostructures, the propeller‐shaped ZnO nanostructures exhibited a higher photocatalytic property for the photocatalytic degradation of Rhodamine B under UV‐light illumination.
Discrete‐Time Indefinite Stochastic LQ Control via SDP and LMI Methods
Authors: Zhou Shaowei , Zhang Weihai
Published: February 2012

This paper studies a discrete‐time stochastic LQ problem over an infinite time horizon with state‐and control‐dependent noises, whereas the weighting matrices in the cost function are allowed to be indefinite. We mainly use semidefinite programming (SDP) and its duality to treat corresponding problems. Several relations among stability, SDP complementary duality, the existence of the solution to stochastic algebraic Riccati equation (SARE), and the optimality of LQ problem are established. We can test mean square stabilizability and solve SARE via SDP by LMIs method.
Forecasting Crude Oil Price and Stock Price by Jump Stochastic Time Effective Neural Network Model
Authors: Wang Jun , Pan Huopo , Liu Fajiang
Published: February 2012

The interacting impact between the crude oil prices and the stock market indices
in China is investigated in the present paper, and the corresponding statistical
behaviors are also analyzed. The database is based on the crude oil prices of Daqing
and Shengli in the 7‐year period from January 2003 to December 2009 and also
on the indices of SHCI, SZCI, SZPI, and SINOPEC with the same time period. A
jump stochastic time effective neural network model is introduced and applied to
forecast the fluctuations of the time series for the crude oil prices and the stock
indices, and we study the corresponding statistical properties by comparison. The
experiment analysis shows that when the price fluctuation is small, the predictive
values are close to the actual values, and when the price fluctuation is large, the
predictive values deviate from the actual values to some degree. Moreover, the
correlation properties are studied by the detrended fluctuation analysis, and the
results illustrate that there are positive correlations both in the absolute returns of
actual data and predictive data.
Airway Remodelling in Asthma and COPD: Findings, Similarities, and Differences Using Quantitative CT
Authors: Dournes Gaël , Laurent François
Published: February 2012

Airway remodelling is a well-established feature in asthma and chronic obstructive lung disease (COPD), secondary to chronic airway inflammation. The structural changes found on pathological examination of remodelled airway wall have been shown to display similarities but also differences. Computed tomography (CT) is today a remarkable tool to assess airway wall morphologyin vivosince submillimetric acquisitions over the whole lung volume could be obtained allowing 3D evaluation. Recently, CT-derived indices extracted from CT images have been described and are thought to assess airway remodelling. This may help understand the complex mechanism underlying the remodelling process, which is still not fully understood. This paper summarizes the various methods described to quantify airway remodelling in asthma and COPD using CT, and similarities and differences between both diseases will be emphasized.
Cytotoxic and Antifungal Activities of 5-Hydroxyramulosin, a Compound Produced by an Endophytic Fungus Isolated fromCinnamomum mollisimum
Authors: Santiago Carolina , Fitchett Chris , Munro Murray H. G. , Jalil Juriyati , Santhanam Jacinta
Published: February 2012

An endophytic fungus isolated from the plantCinnamomum mollissimumwas investigated for the bioactivity of its metabolites. The fungus, similar to aPhomasp., was cultured in potato dextrose broth for two weeks, followed by extraction with ethyl acetate. The crude extract obtained was fractionated by high-performance liquid chromatography. Both crude extract and fractions were assayed for cytotoxicity against P388 murine leukemic cells and inhibition of bacterial and fungal pathogens. The bioactive extract fraction was purified further and characterized by nuclear magnetic resonance, mass spectral and X-ray crystallography analysis. A polyketide compound, 5-hydroxyramulosin, was identified as the constituent of the bioactive fungal extract fraction. This compound inhibited the fungal pathogenAspergillus niger(IC501.56 μg/mL) and was cytotoxic against murine leukemia cells (IC502.10 μg/mL). 5-Hydroxyramulosin was the major compound produced by the endophytic fungus. This research suggests that fungal endophytes are a good source of bioactive metabolites which have potential applications in medicine.
Evolutionary Implications of Mechanistic Models of TE-Mediated Hybrid Incompatibility
Authors: Castillo Dean M. , Moyle Leonie C.
Published: February 2012

New models of TE repression in plants (specificallyArabidopsis) have suggested specific mechanisms by which TE misregulation in hybrids might result in the expression of hybrid inviability. If true, these models suggest as yet undescribed consequences for (1) mechanistic connections between hybrid problems expressed at different postzygotic stages (e.g., inviability versus sterility), (2) the predicted strength, stage, and direction of isolation between diverging lineages that differ in TE activity, and (3) the association between species attributes that influence TE dynamics (e.g., mode of reproduction, geographical structure) and the rate at which they could accumulate incompatibilities. In this paper, we explore these implications and outline future empirical directions for generating data necessary to evaluate them.
Reliability and External Validity of AMSTAR in Assessing Quality of TCM Systematic Reviews
Authors: Kang Deying , Wu Yuxia , Hu Dan , Hong Qi , Wang Jialiang , Zhang Xin
Published: February 2012

Objective. The aim of this study is to measure the reliability and external validity of AMSTAR by applying it to a sample of TCM systematic reviews.Study Design and Methods. We tested the agreement, reliability, construct validity, and feasibility of AMSTAR through comparisons with OQAQ. Statistical analyses were performed by using SPSS 13.0.Results. A random of sample with 41 TCM systematic reviews was selected from a database. The interrater agreement of the individual items of AMSTAR was moderate with a mean kappa of 0.50 (95% CI: 0.26, 0.73). The ICC for AMSTAR against OQAQ (total score of 9 items, excluding item 10) was 0.87 (95% CI: 0.76, 0.93).Conclusions. Although there is room for improvement on few items, the new tool is reliable, valid, and easy to use for methodological quality assessment of systematic reviews on TCM.
Associations of Sun Exposure with 25-Hydroxyvitamin D and Parathyroid Hormone Levels in a Cohort of Hypertensive Patients: The Graz Endocrine Causes of Hypertension (GECOH) Study
Authors: Pilz Stefan , Kienreich Katharina , Stückler Daniel , Meinitzer Andreas , Tomaschitz Andreas
Published: February 2012

Sunlight-induced vitamin D, synthesis in the skin is the major source of vitamin D, but data on the relationship of sun-related behaviour with vitamin D and parathyroid hormone (PTH) levels are relatively sparse. We evaluated whether habitual sun exposure is associated with 25-hydroxyvitamin D (25[OH]D) and PTH levels and whether there exist seasonal variations. We examined 111 hypertensive patients in Austria (latitude 47° N). Frequent sunbathing at home and outdoor sports were associated with higher 25(OH)D levels (P<0.05for both). Red or blond scalp hair as a child, memory of sunburns, preferring sunbathing, frequent stays on the beach or in open-air pools, and solarium use were associated with lower PTH levels (P<0.05for all). Multiple linear regression analyses including age, sex, and body mass index showed that sun exposure score was significantly associated with 25(OH)D (betacoefficient=0.27;P=0.004) and by trend with PTH (betacoefficient=−0.16;P=0.09). These associations were more prominent in summer in which 25(OH)D levels were significantly higher compared to winter. Translation of these findings into recommendations for the prevention and treatment of vitamin D deficiency remains a challenge for the future.
The Design and Construction of K11: A Novelα-Helical Antimicrobial Peptide
Authors: Jin-Jiang Huang , Jin-Chun Lu , Min Lu , Qing-Shan Huang , Guo-Dong Li
Published: February 2012

Amphipathicα-helical antimicrobial peptides comprise a class of broad-spectrum agents that are used against pathogens. We designed a series of antimicrobial peptides, CP-P (KWKSFIKKLTSKFLHLAKKF) and its derivatives, and determined their minimum inhibitory concentrations (MICs) againstPseudomonas aeruginosa, their minimum hemolytic concentrations (MHCs) for human erythrocytes, and the Therapeutic Index (MHC/MIC ratio). We selected the derivative peptide K11, which had the highest therapeutic index (320) among the tested peptides, to determine the MICs against Gram-positive and Gram-negative bacteria and 22 clinical isolates includingAcinetobacter baumannii, methicillin-resistantStaphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus epidermidis,andKlebsiella pneumonia. K11 exhibited low MICs (less than 10 μg/mL) and broad-spectrum antimicrobial activity, especially against clinically isolated drug-resistant pathogens. Therefore, these results indicate that K11 is a promising candidate antimicrobial peptide for further studies.
AGN Obscuration and the Unified Model
Authors: Bianchi Stefano , Maiolino Roberto , Risaliti Guido
Published: February 2012

Unification Models of Active Galactic Nuclei postulate that all the observed differences between type 1 and type 2 objects are due to orientation effects with respect to the line of sight to the observer. The key ingredient of these models is the obscuring medium, historically envisaged as a toroidal structure on a parsec scale. However, many results obtained in the last few years are clearly showing the need for a more complex geometrical distribution of the absorbing media. In this paper, we review the various pieces of evidence for obscuring media on different scales, from the vicinity of the black hole to the host galaxy, in order to picture an updated unification scenario explaining the complex observed phenomenology. We conclude by mentioning some of the open issues.
Connecting the Lines between Hypogonadism and Atherosclerosis
Authors: Fahed Akl C. , Gholmieh Joanna M. , Azar Sami T.
Published: February 2012

Epidemiological studies show that atherosclerotic cardiovascular disease is a leading cause of morbidity and mortality worldwide and point to gender differences with ageing males being at highest risk. Atherosclerosis is a complex process that has several risk factors and mediators. Hypogonadism is a commonly undiagnosed disease that has been associated with many of the events, and risk factors leading to atherosclerosis. The mechanistic relations between testosterone levels, atherosclerotic events, and risk factors are poorly understood in many instances, but the links are clear. In this paper, we summarize the research journey that explains the link between hypogonadism, each of the atherosclerotic events, and risk factors. We look into the different areas from which lessons could be learned, including epidemiological studies, animal and laboratory experiments, studies on androgen deprivation therapy patients, and studies on testosterone-treated patients. We finish by providing recommendations for the clinician and needs for future research.