bluuebunny/crossref_metadata_2025 huggingface dataset:
A stem cell marker-expressing subset of enteroendocrine cells resides at the crypt base in the small intestine
Authors: Sei Yoshitatsu , Lu Xinping , Liou Alice , Zhao Xilin , Wank Stephen A.
Published: November 2010

The spatial orientation of the enteroendocrine cells along the crypt-villus axis is closely associated with their differentiation in the intestine. Here we studied this relationship using primary duodenal crypts and an ex vivo organoid system established from cholecystokinin-green fluorescent protein (CCK-GFP) transgenic mice. In the primary duodenal crypts, GFP+ cells were found not only in the upper crypt but also at the crypt base, where the stem cells reside. Many GFP+ cells below +4 position were positive for the putative intestinal stem cell markers, leucine-rich repeat-containing G protein-coupled receptor 5, CD133, and doublecortin and CaM kinase-like-1, and also for the neuroendocrine transcription factor neurogenin 3. However, these cells were neither stem nor transient amplifying precursor cells because they were negative for both Ki-67 and phospho-Histone H3 and positive for the mature endocrine marker chromogranin A. Furthermore, these cells expressed multiple endocrine hormones. Tracking of GFP+ cells in the organoids from CCK-GFP mice indicated that GFP+ cells were first observed around the +4 position, some of which localized to the crypt base later in the culture period. These results suggest that a subset of enteroendocrine cells migrates down to the crypt base or stays localized at the crypt base, where they express stem and postmitotic endocrine markers. Further investigation of the function of this subset may provide novel insights into the genesis and development of enteroendocrine cells as well as enteroendocrine tumorigenesis.
Modelflow underestimates cardiac output in heat-stressed individuals
Authors: Shibasaki Manabu , Wilson Thad E. , Bundgaard-Nielsen Morten , Seifert Thomas , Secher Niels H. , Crandall Craig G.
Published: November 2010

An estimation of cardiac output can be obtained from arterial pressure waveforms using the Modelflow method. However, whether the assumptions associated with Modelflow calculations are accurate during whole body heating is unknown. This project tested the hypothesis that cardiac output obtained via Modelflow accurately tracks thermodilution-derived cardiac outputs during whole body heat stress. Acute changes of cardiac output were accomplished via lower-body negative pressure (LBNP) during normothermic and heat-stressed conditions. In nine healthy normotensive subjects, arterial pressure was measured via brachial artery cannulation and the volume-clamp method of the Finometer. Cardiac output was estimated from both pressure waveforms using the Modeflow method. In normothermic conditions, cardiac outputs estimated via Modelflow (arterial cannulation: 6.1 ± 1.0 l/min; Finometer 6.3 ± 1.3 l/min) were similar with cardiac outputs measured by thermodilution (6.4 ± 0.8 l/min). The subsequent reduction in cardiac output during LBNP was also similar among these methods. Whole body heat stress elevated internal temperature from 36.6 ± 0.3 to 37.8 ± 0.4°C and increased cardiac output from 6.4 ± 0.8 to 10.9 ± 2.0 l/min when evaluated with thermodilution ( P < 0.001). However, the increase in cardiac output estimated from the Modelflow method for both arterial cannulation (2.3 ± 1.1 l/min) and Finometer (1.5 ± 1.2 l/min) was attenuated compared with thermodilution (4.5 ± 1.4 l/min, both P < 0.01). Finally, the reduction in cardiac output during LBNP while heat stressed was significantly attenuated for both Modelflow methods (cannulation: −1.8 ± 1.2 l/min, Finometer: −1.5 ± 0.9 l/min) compared with thermodilution (−3.8 ± 1.19 l/min). These results demonstrate that the Modelflow method, regardless of Finometer or direct arterial waveforms, underestimates cardiac output during heat stress and during subsequent reductions in cardiac output via LBNP.
Differential expression of Na+-Cl−cotransporter and Na+-K+-Cl−cotransporter 2 in the distal nephrons of euryhaline and seawater pufferfishes
Authors: Kato Akira , Muro Takayuki , Kimura Yuuri , Li Shanshan , Islam Zinia , Ogoshi Maho , Doi Hiroyuki , Hirose Shigehisa
Published: November 2010

The process of NaCl reabsorption in the distal nephron allows freshwater fishes to excrete hypotonic urine and seawater fishes to excrete urine containing high concentrations of divalent ions; the relevant transporters, however, have not yet been identified. In the mammalian distal nephron, NaCl absorption is mediated by Na+-K+-Cl−cotransporter 2 (NKCC2, Slc12a1) in the thick ascending limb, Na+-Cl−cotransporter (NCC, Slc12a3) in the distal convoluted tubule, and epithelial sodium channel (ENaC) in the collecting duct. In this study, we compared the expression profiles of these proteins in the kidneys of euryhaline and seawater pufferfishes. Mining the fugu genome identified one NKCC2 gene and one NCC gene, but no ENaC gene. RT-PCR and in situ hybridization analyses demonstrated that NKCC2 was highly expressed in the distal tubules and NCC was highly expressed in the collecting ducts of euryhaline pufferfish (mefugu, Takifugu obscurus ). On the other hand, the kidney of seawater pufferfish (torafugu, Takifugu rubripes ), which lacked distal tubules, expressed very low levels of NCC, and, in the collecting ducts, high levels of NKCC2. Acclimation of mefugu to seawater resulted in a 2.7× decrease in NCC expression, whereas NKCC2 expression was not markedly affected. Additionally, internalization of NCC from the apical surface of the collecting ducts was observed. These results suggest that NaCl reabsorption in the distal nephron of the fish kidney is mediated by NCC and NKCC2 in freshwater and by NKCC2 in seawater.
Nuclear membrane receptors for ET-1 in cardiovascular function
Authors: Bkaily Ghassan , Avedanian Levon , Al-Khoury Johny , Provost Chantale , Nader Moni , D'Orléans-Juste Pedro , Jacques Danielle
Published: November 2010

Plasma membrane endothelin type A (ETA) receptors are internalized and recycled to the plasma membrane, whereas endothelin type B (ETB) receptors undergo degradation and subsequent nuclear translocation. Recent studies show that G protein-coupled receptors (GPCRs) and ion transporters are also present and functional at the nuclear membranes of many cell types. Similarly to other GPCRs, ETAand ETBare present at both the plasma and nuclear membranes of several cardiovascular cell types, including human cardiac, vascular smooth muscle, endocardial endothelial, and vascular endothelial cells. The distribution and density of ETARs in the cytosol (including the cell membrane) and the nucleus (including the nuclear membranes) differ between these cell types. However, the localization and density of ET-1 and ETBreceptors are similar in these cell types. The extracellular ET-1-induced increase in cytosolic ([Ca]c) and nuclear ([Ca]n) free Ca2+is associated with an increase of cytosolic and nuclear reactive oxygen species. The extracellular ET-1-induced increase of [Ca]cand [Ca]nas well as intracellular ET-1-induced increase of [Ca]nare cell-type dependent. The type of ET-1 receptor mediating the extracellular ET-1-induced increase of [Ca]cand [Ca]ndepends on the cell type. However, the cytosolic ET-1-induced increase of [Ca]ndoes not depend on cell type. In conclusion, nuclear membranes' ET-1 receptors may play an important role in overall ET-1 action. These nuclear membrane ET-1 receptors could be targets for a new generation of antagonists.
Epithelial-to-mesenchymal transition in cyst lining epithelial cells in an orthologous PCK rat model of autosomal-recessive polycystic kidney disease
Authors: Togawa Hiroko , Nakanishi Koichi , Mukaiyama Hironobu , Hama Taketsugu , Shima Yuko , Sako Mayumi , Miyajima Masayasu , Nozu Kandai , Nishii Kazuhiro , Nagao Shizuko , Takahashi Hisahide , Iijima Kazumoto , Yoshikawa Norishige
Published: November 2010

In polycystic kidney disease (PKD), cyst lining cells show polarity abnormalities. Recent studies have demonstrated loss of cell contact in cyst cells, suggesting induction of epithelial-to-mesenchymal transition (EMT). Recently, EMT has been implicated in the pathogenesis of PKD. To explore further evidence of EMT in PKD, we examined age- and segment-specific expression of adhesion molecules and mesenchymal markers in PCK rats, an orthologous model of human autosomal-recessive PKD. Kidneys from 5 male PCK and 5 control rats each at 0 days, 1, 3, 10, and 14 wk, and 4 mo of age were serially sectioned and stained with segment-specific markers and antibodies against E-cadherin, Snail1, β-catenin, and N-cadherin. mRNAs for E-cadherin and Snail1 were quantified by real-time PCR. Vimentin, fibronectin, and α-smooth muscle actin (α-SMA) expressions were assessed as mesenchymal markers. E-cadherin expression pattern was correlated with the disease pathology in that tubule segments showing the highest expression in control had much severer cyst formation in PCK rats. In PCK rats, E-cadherin and β-catenin in cystic tubules was attenuated and localized to lateral areas of cell-cell contact, whereas nuclear expression of Snail1 increased in parallel with cyst enlargement. Some epithelial cells in large cysts derived from these segments, especially in adjacent fibrotic areas, showed positive immunoreactivity for vimentin and fibronectin. In conclusion, these findings suggest that epithelial cells in cysts acquire mesenchymal features in response to cyst enlargement and participate in progressive renal fibrosis. Our study clarified the nephron segment-specific cyst profile related to EMT in PCK rats. EMT may play a key role in polycystic kidney disease.
Cellular mechanisms underlying nitric oxide-induced vasodilation of descending vasa recta
Authors: Edwards Aurélie , Cao Chunhua , Pallone Thomas L.
Published: November 2010

It has been observed that vasoactivity of explanted descending vasa recta (DVR) is modulated by intrinsic nitric oxide (NO) and superoxide (O2−) production (Cao C, Edwards A, Sendeski M, Lee-Kwon W, Cui L, Cai CY, Patzak A, Pallone TL. Am J Physiol Renal Physiol 299: F1056–F1064, 2010). To elucidate the cellular mechanisms by which NO, O2−and hydrogen peroxide (H2O2) modulate DVR pericyte cytosolic Ca2+concentration ([Ca]cyt) and vasoactivity, we expanded our mathematical model of Ca2+signaling in pericytes. We incorporated simulations of the pathways that translate an increase in [Ca]cytto the activation of myosin light chain (MLC) kinase and cell contraction, as well as the kinetics of NO and reactive oxygen species formation and their effects on [Ca]cytand MLC phosphorylation. The model reproduced experimentally observed trends of DVR vasoactivity that accompany exposure to Nω-nitro-l-arginine methyl ester, 8-Br-cGMP, Tempol, and H2O2. Our results suggest that under resting conditions, NO-induced activation of cGMP maintains low levels of [Ca]cytand MLC phosphorylation to minimize basal tone. This results from stimulation of Ca2+uptake from the cytosol into the SR via SERCA pumps, Ca2+efflux into the extracellular space via plasma membrane Ca2+pumps, and MLC phosphatase (MLCP) activity. We predict that basal concentrations of O2−and H2O2have negligible effects on Ca2+signaling and MLC phosphorylation. At concentrations above 1 nM, O2−is predicted to modulate [Cacyt] and MCLP activity mostly by reducing NO bioavailability. The DVR vasoconstriction that is induced by high concentrations of H2O2can be explained by H2O2-mediated downregulation of MLCP and SERCA activity. We conclude that intrinsic generation of NO by the DVR wall may be sufficient to inhibit vasoconstriction by maintaining suppression of MLC phosphorylation.
Graded Reductions in Oxygenation Evoke Graded Reconfiguration of the Isolated Respiratory Network
Authors: Hill Andrew A. , Garcia Alfredo J. , Zanella Sebastien , Upadhyaya Ridhdhi , Ramirez Jan Marino
Published: November 2010

Neurons depend on aerobic metabolism, yet are very sensitive to oxidative stress and, as a consequence, typically operate in a low O2environment. The balance between blood flow and metabolic activity, both of which can vary spatially and dynamically, suggests that local O2availability markedly influences network output. Yet the understanding of the underlying O2-sensing mechanisms is limited. Are network responses regulated by discrete O2-sensing mechanisms or, rather, are they the consequence of inherent O2sensitivities of mechanisms that generate the network activity? We hypothesized that a broad range of O2tensions progressively modulates network activity of the pre-Bötzinger complex (preBötC), a neuronal network critical to the central control of breathing. Rhythmogenesis was measured from the preBötC in transverse neonatal mouse brain stem slices that were exposed to graded reductions in O2between 0 and 95% O2, producing tissue oxygenation values ranging from 20 ± 18 (mean ± SE) to 440 ± 56 Torr at the slice surface, respectively. The response of the preBötC to graded changes in O2is progressive for some metrics and abrupt for others, suggesting that different aspects of the respiratory network have different sensitivities to O2.
Neuronal Sodium Leak Channel Is Responsible for the Detection of Sodium in the Rat Median Preoptic Nucleus
Authors: Tremblay Christina , Berret Emmanuelle , Henry Mélaine , Nehmé Benjamin , Nadeau Louis , Mouginot Didier
Published: November 2010

Sodium (Na+) ions are of primary importance for hydromineral and cardiovascular homeostasis, and the level of Na+ in the body fluid compartments [plasma and cerebrospinal fluid (CSF)] is precisely monitored in the hypothalamus. Glial cells seem to play a critical role in the mechanism of Na+ detection. However, the precise role of neurons in the detection of extracellular Na+ concentration ([Na+]out) remains unclear. Here we demonstrate that neurons of the median preoptic nucleus (MnPO), a structure in close contact with the CSF, are specific Na+ sensors. Electrophysiological recordings were performed on dissociated rat MnPO neurons under isotonic [Na+] (100 mM NaCl) with local application of hypernatriuric (150, 180 mM NaCl) or hyponatriuric (50 mM NaCl) external solution. The hyper- and hyponatriuric conditions triggered an in- and an outward current, respectively. The reversal potential of the current matched the equilibrium potential of Na+, indicating that a change in [Na+]out modified the influx of Na+ in the MnPO neurons. The conductance of the Na+ current was not affected by either the membrane potential or the [Na+]out. Moreover, the channel was highly selective for lithium over guanidinium. Together, these data identified the channel as a Na+ leak channel. A high correlation between the electrophysiological recordings and immunofluorescent labeling for the NaX channel in dissociated MnPO neurons strongly supports this channel as a candidate for the Na+ leak channel responsible for the Na+-sensing ability of rat MnPO neurons. The absence of NaX labeling and of a specific current evoked by a change in [Na+]out in mouse MnPO neurons suggests species specificity in the hypothalamus structures participating in central Na+ detection.
Regression-Based Identification of Behavior-Encoding Neurons During Large-Scale Optical Imaging of Neural Activity at Cellular Resolution
Authors: Miri Andrew , Daie Kayvon , Burdine Rebecca D. , Aksay Emre , Tank David W.
Published: November 2010

The advent of methods for optical imaging of large-scale neural activity at cellular resolution in behaving animals presents the problem of identifying behavior-encoding cells within the resulting image time series. Rapid and precise identification of cells with particular neural encoding would facilitate targeted activity measurements and perturbations useful in characterizing the operating principles of neural circuits. Here we report a regression-based approach to semiautomatically identify neurons that is based on the correlation of fluorescence time series with quantitative measurements of behavior. The approach is illustrated with a novel preparation allowing synchronous eye tracking and two-photon laser scanning fluorescence imaging of calcium changes in populations of hindbrain neurons during spontaneous eye movement in the larval zebrafish. Putative velocity-to-position oculomotor integrator neurons were identified that showed a broad spatial distribution and diversity of encoding. Optical identification of integrator neurons was confirmed with targeted loose-patch electrical recording and laser ablation. The general regression-based approach we demonstrate should be widely applicable to calcium imaging time series in behaving animals.
Synaptic Interactions Underlying Synchronized Inhibition in the Basal Amygdala: Evidence for Existence of Two Types of Projection Cells
Authors: Popescu Andrei T. , Paré Denis
Published: November 2010

The basal amygdala (BA) plays a key role in mediating the facilitating effects of emotions on memory. Recent findings indicate that this function depends on the ability of BA neurons to generate coherent oscillatory activity, facilitating synaptic plasticity in target neurons. However, the mechanisms allowing BA neurons to synchronize their activity remain poorly understood. Here, we aimed to shed light on this question, focusing on a slow periodic inhibitory oscillation previously observed in the BA in vitro. Paired patch recordings showed that these large inhibitory postsynaptic potentials (IPSPs) occur almost synchronously in BA projection neurons, that they were typically not preceded by excitatory postsynaptic potentials (EPSPs), and that they had little or no correlate in neighboring amygdala nuclei or cortical fields. The initial phase of the IPSPs was associated with an increase in membrane potential fluctuations at 50–100 Hz. In keeping with this, the IPSPs seen in projection cells were correlated with repetitive firing at 50–100 Hz in presumed interneurons and they could be abolished by picrotoxin. However, the IPSPs were also sensitive to 6-cyano-7-nitroquinoxaline-2,3-dione, implying that they arose from the interplay between glutamatergic and GABAergic BA neurons. In support of this idea, we identified a small subset of projection cells (15%), positively identified as such by retrograde labeling from BA projection sites, that began firing shortly before the IPSP onset and presumably drove interneuronal firing. These results add to a rapidly growing body of data indicating that the BA contains at least two distinct types of projection cells that vary in their relation with interneurons and extra-amygdala targets.
Presynaptic CB1 Receptors Regulate Synaptic Plasticity at Cerebellar Parallel Fiber Synapses
Authors: Carey Megan R. , Myoga Michael H. , McDaniels Kimberly R. , Marsicano Giovanni , Lutz Beat , Mackie Ken , Regehr Wade G.
Published: November 2010

Endocannabinoids are potent regulators of synaptic strength. They are generally thought to modify neurotransmitter release through retrograde activation of presynaptic type 1 cannabinoid receptors (CB1Rs). In the cerebellar cortex, CB1Rs regulate several forms of synaptic plasticity at synapses onto Purkinje cells, including presynaptically expressed short-term plasticity and, somewhat paradoxically, a postsynaptic form of long-term depression (LTD). Here we have generated mice in which CB1Rs were selectively eliminated from cerebellar granule cells, whose axons form parallel fibers. We find that in these mice, endocannabinoid-dependent short-term plasticity is eliminated at parallel fiber, but not inhibitory interneuron, synapses onto Purkinje cells. Further, parallel fiber LTD is not observed in these mice, indicating that presynaptic CB1Rs regulate long-term plasticity at this synapse.
BRCA2 and Nucleophosmin Coregulate Centrosome Amplification and Form a Complex with the Rho Effector Kinase ROCK2
Authors: Wang Hui-Feng , Takenaka Katsuya , Nakanishi Akira , Miki Yoshio
Published: November 2010

BRCA2 germline mutations account for the majority of heredity breast and ovarian cancer. Besides its role in DNA damage repair, BRCA2 also plays an important role in cytokinesis, transcription regulation, and cancer cell proliferation. Recently, we reported that BRCA2 localizes to centrosomes as well as nuclei and the dysfunction of BRCA2 in a centrosome causes abnormalities in cell division. Here, we identified a nucleolar phosphoprotein, nucleophosmin (NPM), as a novel BRCA2-associated protein. We also detected the binding of BRCA2 to ROCK2, an effector of Rho small GTPase. Because it is known that ROCK2 binds to NPM at centrosomes, these 3 proteins may form a complex. NPM-binding region was within amino acids 639–1,000 of BRCA2. Exogenous expression of this BRCA2 region resulted in aberrant centrosome amplification and a high frequency of multinucleated cells. Our results suggested that a complex consisting of BRCA2, NPM, and ROCK2 maintains the numerical integrity of centrosomes and accurate cell division and that dysfunction of this regulation might be involved in the tumorigenesis of breast cancer. Cancer Res; 71(1); 68–77. ©2011 AACR.
Risk of Infection-Related Cancers after the Loss of a Child: A Follow-up Study in Sweden
Authors: Fang Fang , Fall Katja , Sparén Pär , Adami Hans-Olov , Valdimarsdóttir Heiddis B. , Lambe Mats , Valdimarsdóttir Unnur
Published: November 2010

It is unknown whether severe emotional stress due to loss of a child influences the risk of cancers susceptible to immune modulation such as infection-related cancers. We conducted a historic cohort study in 1990 to 2004 on the basis of the Swedish Multi-Generation Register including 4,687,073 parents. Death of a child was identified through the Causes of Death Register. Poisson regression was used to derive the relative risks (RR) and 95% confidence intervals (CI) of infection-related cancers, comparing the incidence rates of parents who lost a child with those who never lost a child. A total of 101,306 parents (2%) had lost a child during follow-up, among whom 1,608 subsequently developed infection-related cancers. After adjustment for age, sex, calendar year, educational level, and civil status, the overall RR of 14 cancers studied was 1.07 (95% CI: 1.02–1.12). Parents who lost a child were particularly at a higher risk for cancers potentially associated with human papilloma virus (HPV) infection such as cervical cancer (RR: 1.46; 95% CI: 1.17–1.80). Higher RRs for most cancers were obtained within 5 years after child loss and excess risk for liver and stomach cancers was confined to that period. No association was observed for lymphoma and nonmelanoma skin cancer at any time point after child loss. Although potential confounding by unmeasured factors cannot be ruled out, our findings lend support to the hypothesis that severe life stressors, such as child loss, may raise the risk for several, chiefly HPV-related, cancers. Cancer Res; 71(1); 116–22. ©2011 AACR.
A Randomized Clinical Trial of the Effects of Supplemental Calcium and Vitamin D3 on Markers of Their Metabolism in Normal Mucosa of Colorectal Adenoma Patients
Authors: Ahearn Thomas U. , McCullough Marjorie L. , Flanders W. Dana , Long Qi , Sidelnikov Eduard , Fedirko Veronika , Daniel Carrie R. , Rutherford Robin E. , Shaukat Aasma , Bostick Roberd M.
Published: November 2010

In cancer cell lines and rodent models, calcium and vitamin D favorably modulate cell proliferation, differentiation, and apoptosis in colonic epithelia. These effects may be modulated by local expression of the calcium receptor (CaR), the vitamin D receptor (VDR), and the P450 cytochromes, CYP27B1 and CYP24A1; however, they have yet to be investigated in humans. To address this gap, we conducted a randomized, double-blinded, placebo-controlled 2 × 2 factorial clinical trial. Patients with at least one pathology-confirmed colorectal adenoma were treated with 2 g/d elemental calcium and/or 800 IU/d vitamin D3 versus placebo over 6 months (n = 92; 23 per group). CaR, VDR, CYP27B1, and CYP24A1 expression and distribution in biopsies of normal appearing rectal mucosa were detected by standardized, automated immunohistochemistry and quantified by image analysis. In the calcium-supplemented group, CaR expression increased 27% (P = 0.03) and CYP24A1 expression decreased 21% (P = 0.79). In the vitamin D3-supplemented group, CaR expression increased 39% (P = 0.01) and CYP27B1 expression increased 159% (P = 0.06). In patients supplemented with both calcium and vitamin D3, VDR expression increased 19% (P = 0.13) and CaR expression increased 24% (P = 0.05). These results provide mechanistic support for further investigation of calcium and vitamin D3 as chemopreventive agents against colorectal neoplasms, and CaR, VDR, CYP27B1, and CYP24A1 as modifiable, preneoplastic risk biomarkers for colorectal neoplasms. Cancer Res; 71(2); 413–23. ©2010 AACR.
Cancer Cells Cut Homophilic Cell Adhesion Molecules and Run
Authors: Craig Sonya E.L. , Brady-Kalnay Susann M.
Published: November 2010

The term contact inhibition (CI) encompasses the cellular changes that result in cessation of cell migration and of proliferation due to signals transduced when one cell comes into physical contact with another cell. Cancer cells, however, do not contact inhibit. A molecular understanding of the loss of CI in cancer cells is important for understanding tumor progression. In this Perspective, we propose that the loss of CI observed in cancer cells is the result of extracellular proteolysis of transmembrane cell–cell cell adhesion molecules (CAM) in the tumor microenvironment. Proteolysis of homophilic cell–cell CAMs results in a shed extracellular fragment and released cytoplasmic fragment(s) that disrupts adhesion and induces signals that promote proliferation and/or migration. The importance of this observation in tumor progression is supported by the presence of the shed extracellular fragments of homophilic cell–cell CAMs in serum and tumor tissue of cancer patients suggesting that instead of acting as tumor suppressors, the shed CAM extracellular and cytoplasmic fragments actually function as oncogenes. The study of cell–cell CAM cleavage will provide important and novel means of diagnosing, imaging, and treating tumor progression. Cancer Res; 71(2); 303–9. ©2010 AACR.
TGF-β-RI Kinase Inhibitor SD-208 Reduces the Development and Progression of Melanoma Bone Metastases
Authors: Mohammad Khalid S. , Javelaud Delphine , Fournier Pierrick G. J. , Niewolna Maria , McKenna C. Ryan , Peng Xiang H. , Duong Vu , Dunn Lauren K. , Mauviel Alain , Guise Theresa A.
Published: November 2010

Melanoma often metastasizes to bone where it is exposed to high concentrations of TGF-β. Constitutive Smad signaling occurs in human melanoma. Because TGF-β promotes metastases to bone by several types of solid tumors including breast cancer, we hypothesized that pharmacologic blockade of the TGF-β signaling pathway may interfere with the capacity of melanoma cells to metastasize to bone. In this study, we tested the effect of a small molecule inhibitor of TGF-β receptor I kinase (TβRI), SD-208, on various parameters affecting the development and progression of melanoma, both in vitro and in a mouse model of human melanoma bone metastasis. In melanoma cell lines, SD-208 blocked TGF-β induction of Smad3 phosphorylation, Smad3/4-specific transcription, Matrigel invasion and expression of the TGF-β target genes PTHrP, IL-11, CTGF, and RUNX2. To assess effects of SD-208 on melanoma development and metastasis, nude mice were inoculated with 1205Lu melanoma cells into the left cardiac ventricle and drug was administered by oral gavage on prevention or treatment protocols. SD-208 (60 mg/kg/d), started 2days before tumor inoculation prevented the development of osteolytic bone metastases compared with vehicle. In mice with established bone metastases, the size of osteolytic lesions was significantly reduced after 4weeks treatment with SD-208 compared with vehicle-treated mice. Our results demonstrate that therapeutic targeting of TGF-β may prevent the development of melanoma bone metastases and decrease the progression of established osteolytic lesions. Cancer Res; 71(1); 175–84. ©2010 AACR.
Characterization of Tumor-Suppressive Function of SOX6 in Human Esophageal Squamous Cell Carcinoma
Authors: Qin Yan-Ru , Tang Hong , Xie Fajun , Liu Haibo , Zhu Yinghui , Ai Jiaoyu , Chen Leilei , Li Yan , Kwong Dora L. , Fu Li , Guan Xin-Yuan
Published: November 2010

Purpose: By using cDNA microarray analysis, we identified a transcriptional factor, SOX6, was frequently downregulated in esophageal squamous cell carcinoma (ESCC). The aim of this study is to investigate the role of SOX6 in human esophageal cancer development, and to examine the prevalence and clinical significance of SOX6 downregulation in ESCC.

Experimental Design: Expressions of SOX6 mRNA in 50 ESCCs and SOX6 protein in 300 ESCCs were investigated by semiquantitative RT-PCR and immunohistochemistry, respectively. The tumor-suppressive function of SOX6 was characterized by cell growth, foci formation, wound-healing and cell invasive assays, and tumor xenograft experiment. Western blot analysis was applied to detect protein expression levels.

Results: SOX6 was frequently downregulated in primary ESCCs in both mRNA level (29/50, 58%) and protein level (149/219, 68.0%), which was significantly associated with the poor differentiation (P = 0.029), lymph node metastases (P = 0.014), advanced TNM stage (P = 0.000), and disease-specific survival (P < 0.001). Multivariate analysis indicated that the downregulation of SOX6 (P = 0.000) was a significant independent prognostic factors for ESCC. Functional studies showed that SOX6 was able to suppress both in vitro and in vivo tumorigenic ability of ESCC cells. The tumor-suppressive mechanism of SOX6 was associated with its role in G1/S cell-cycle arrest by upregulating expressions of p53 and p21WAF1/CIP1 and downregulating expressions of cyclin D1/CDK4, cyclin A, and β-catenin.

Conclusions: We provided the first evidence that SOX6 is a novel tumor-suppressor gene in ESCC development and is a potential prognostic marker in ESCC. Clin Cancer Res; 17(1); 46–55. ©2010 AACR.
Melanoma Chemoprevention in Skin Reconstructs and Mouse Xenografts Using Isoselenocyanate-4
Authors: Nguyen Natalie , Sharma Arati , Nguyen Nhung , Sharma Arun K. , Desai Dhimant , Huh Sung Jin , Amin Shantu , Meyers Craig , Robertson Gavin P.
Published: November 2010

Melanoma incidence and mortality rates continue to increase despite the use of sunscreen as well as screening programs for early surgical excision of premalignant lesions. The steady increase in melanoma incidence suggests that additional preventive approaches are needed to augment these existing strategies. One unexplored area involves targeting genes whose deregulation promotes disease development to prevent melanoma. The Akt3 signaling pathway is one key signaling cascade that plays a central role by deregulating apoptosis to promote development of approximately 70% of melanomas. Isoselenocyanate-4 (ISC-4), derived from isothiocyanates by increasing the alkyl chain length and replacing sulfur with selenium, has been developed to target this important signaling pathway in melanomas; however, its chemopreventive potential is unknown. In this study, the chemopreventive efficacy of topical ISC-4 was evaluated in a laboratory-generated human skin melanoma model containing early melanocytic lesion or advanced stage melanoma cell lines and in animals containing invasive xenografted human melanoma. Repeated topical application of ISC-4 reduced tumor cell expansion in the skin model by 80% to 90% and decreased tumor development in animals by approximately 80%. Histologic examination of ISC-4-treated skin showed no obvious damage to skin cells or skin morphology, and treated animals did not exhibit markers indicative of major organ-related toxicity. Mechanistically, ISC-4 prevented melanoma by decreasing Akt3 signaling that lead to a 3-fold increase in apoptosis rates. Thus, topical ISC-4 can delay or slow down melanocytic lesion or melanoma development in preclinical models and could impact melanoma incidence rates if similar results are observed in humans. Cancer Prev Res; 4(2); 248–58. ©2010 AACR.
In vitro Activity of Dalbavancin against Staphylococci Isolated in Istanbul, Turkey
Authors: Aktas Gulseren , Derbentli Sengul
Published: November 2010

Background: Staphylococci are a major cause of both community- and hospital-acquired infections. Dalbavancin is a new bactericidal second-generation lipoglycopeptide antibiotic to use in the treatment of multidrug-resistant staphylococcal infections. It is important to determine its activity against staphylococci isolated in Turkey. Dalbavancin has not yet been used in antimicrobial therapy in our country. Method: Dalbavancin was tested against a total of 453 staphylococcal strains by using the reference broth microdilution method. Organisms tested included: methicillin-resistant Staphylococcus aureus (MRSA; 237 strains), methicillin-susceptible S. aureus (MSSA; 144 strains) and methicillin- resistant coagulase-negative staphylococci (MR-CoNS; 72 strains). Results: MIC50 and MIC90 values of dalbavancin against MRSA, MSSA and MR-CoNS were found as ≤0.008 and 0.25 mg/l; 0.016 and 0.125 mg/l; and 0.016 and 0.5 mg/l, respectively. The overall distribution of dalbavancin MIC values ranged from ≤0.008 to 2 mg/l. If the interpretive breakpoint MIC value is ≤1 mg/l, the susceptibility rates of MRSA, MSSA and MR-CoNS strains were determined as 99.6, 100 and 98.6%, respectively. Conclusion: The MIC results for dalbavancin have demonstrated a good activity against both methicillin-sensitive and -resistant staphylococci isolated from hospitalized patients.
Phase I Study of S-1 plus Nedaplatin in Patients with Advanced/Recurrent Head and Neck Cancer
Authors: Kogashiwa Yasunao , Yamauchi Kohichi , Nagafuji Hiroshi , Matsuda Takehiro , Tsubosaka Toshihito , Karaho Takehiro , Maruyama Takeshi , Kohno Naoyuki
Published: November 2010

Background: Cisplatin plus fluorouracil is widely used for the treatment of head and neck cancer. However, the cisplatin plus fluorouracil regimen necessitates hospitalization. Therefore, we planned to develop a new regimen that can be administered on an outpatient basis and performed a phase I study of S-1 + nedaplatin. Methods: S-1 was given orally at a fixed dose for 14 days, and nedaplatin was administered intravenously on day 8 of S-1 administration. The dose of nedaplatin was increased in 10-mg/m2 steps to find the maximum tolerated dose, depending on the appearance of dose-limiting toxicities. Results: A total of 14 patients were registered. The maximum tolerated dose of nedaplatin was determined to be 90 mg/m2. The main toxicities were neutropenia and thrombocytopenia. The response rate was 57.1%. Conclusion: The recommended dose of nedaplatin for a phase II study was determined to be 80 mg/m2. We concluded that our regimen was well tolerated and that the response rate was acceptable.
Postantibiotic Effects of Tigecycline, Colistin Sulfate, and Levofloxacin Alone or Tigecycline-Colistin Sulfate and Tigecycline-Levofloxacin Combinations against Acinetobacter baumannii
Authors: Özbek Berna , Şentürk Aylin
Published: November 2010

Background: Colistin sulfate and levofloxacin, alone and in combination with tigecycline, were investigated for their in vitro activities and postantibiotic effects (PAEs) on6 meropenem-resistant Acinetobacter baumannii. Methods: The in vitro activities of colistin sulfate and levofloxacin in combination with tigecycline were determined using a microbroth checkerboard technique. The results were interpreted based on the fractional inhibitory concentration index. To determine the PAEs, A. baumannii strains in the logarithmic phase of growth were exposed for 1 h to antibiotics, alone and in combination. Recovery periods of test cultures were evaluated using viable counting after centrifugation. Results: One synergistic interaction was observed for each of the tigecycline-colistin sulfate and tigecycline-levofloxacin combinations. Colistin sulfate produced a strong PAE ranging from 2.50 to 7.0 h in a concentration-dependent manner. PAEs were induced by levofloxacin (ranging from 0.35 to 2.45 h) and tigecycline (ranging from 0.05 to 1.40 h). In combination, tigecycline slightly changed the PAE of colistin sulfate and levofloxacin against the studied strains. Conclusion: This study’s findings could have important implications for the timing of doses during antimicrobial therapy with tigecycline, colistin sulfate, and levofloxacin alone and in combination.
Transdermal Estradiol and Testosterone Transfer in Man: Existence, Models, and Strategies for Prevention
Authors: Busse K.L. , Maibach H.I.
Published: November 2010

Background: Transdermal hormone application allows delivery of a clinically relevant hormone dose often with fewer systemic side effects than oral formulations. However, transdermal hormone transfer from a dosed individual to naïve interpersonal contact occurs and may cause significant hormone imbalance and adverse effects. Methods: We reviewed PubMed, Medline, and Scopus articles from the years 1950 to 2010 for articles related to transdermal hormone transfer in the setting of in vivo and in vitro human and animal models. We used the following key words: transfer, transdermal, absorption, cutaneous, hormone, estradiol, and testosterone. Unpublished trials were reviewed on the US Food and Drug Administration (FDA) website for product approval. Results: Data reflecting in vivo transfer of transdermal estradiol and testosterone in man is available from case reports, clinical trials, and FDA product information. While results clearly show that transfer can occur, methods for measuring the effect are not standardized and are thus difficult to compare among positive and negative studies. No in vitro human studies or animal models have been developed to specifically examine transfer potential of transdermal estradiol or testosterone. Conclusion: It is necessary to consider the mechanism behind transdermal hormone transfer and consider ways to enhance clinical benefits to the dosed individual while minimizing transfer to a naïve interpersonal contact. A detailed discussion of trial comparisons and future optimization methods may help enhance our understanding of the potential for transdermal hormone transfer and encourage development of newer formulations and/or application methods to minimize its occurrence.
Epigenetic Control of Estrogen Receptor Expression and Tumor Suppressor Genes Is Modulated by Bioactive Food Compounds
Authors: Berner Carolin , Aumüller Eva , Gnauck Anne , Nestelberger Manuela , Just A. , Haslberger Alexander G.
Published: November 2010

Background: The tumor suppressor genes p15INK4b and p16INK4a as well as the estrogen receptor-α (ESR1) gene are abnormally methylated and expressed in colon cancer. The cancer-preventative abilities of several bioactive food components have been linked to their estrogenic and epigenetic activities. Methods: The effect of folic acid, zebularine, resveratrol, genistein and epigallocatechin-3-gallate (EGCG) on tumor cell growth, promoter methylation of ESR1, p15INK4b and p16INK4a and gene expression of ESR1 and ESR2 was analyzed in Caco-2 cells. Gene expression was measured using real-time PCR, and promoter CpG methylation was assessed using bisulfite conversion and methylation-specific PCR. Results: After exposure to a high concentration of folic acid (20 µmol/l), enhanced cancer cell growth and concomitant increased methylation of the ESR1 (3.6-fold), p16INK4a and p15INK4b promoters was observed. A lower concentration of folic acid (2 µmol/l) decreased cell growth. The phytoestrogens genistein and resveratrol enhanced expression of ESR1 (genistein 200 µmol/l: 2.1-fold; resveratrol 50 µmol/l: 6.3-fold) and ESR2 (2.6- and 3.6-fold, respectively). Genistein and resveratrol treatment increased promoter methylation of ESR1 (genistein 200 µmol/l: 2.9-fold; resveratrol 50 µmol/l: 1.4-fold). For p16INK4a, increased methylation was found after exposure to 10 µmol/l resveratrol, but for p15INK4b, decreased methylation was found. Both components showed growth-inhibitory activities. For EGCG, growth inhibition at 100 µmol/l and suppressed promoter methylation of tumor suppressor genes (p16INK4a: 0.9-fold; p15INK4b: 0.6-fold) was seen. Conclusions: Our results show that these food compounds regulate ESR and tumor suppressor gene expression by multiple mechanisms including epigenetic processes. An improved understanding of these epigenetic effects could therefore support specific dietary concepts of epigenetic cancer prevention and intervention.
Hypocupremia-Related Myeloneuropathy following Gastrojejunal Bypass Surgery
Authors: Choi Eric H. , Strum Williamson
Published: November 2010

Gastrojejunal bypass surgery may be complicated by nutritional deficiencies, including trace elements. Copper, which is absorbed in the duodenum and proximal jejunum, is poorly absorbed when a significant portion of the proximal small intestine is bypassed. However, despite this theoretical risk of hypocupremia in the gastrojejunal bypass patient, reports of symptomatic copper deficiency are very rare, and even then the deficiency is often potentiated by an accelerant, such as concomitant zinc ingestion. We report a case of hypocupremia resulting in hematologic abnormalities and myeloneuropathy after gastrojejunal bypass surgery for morbid obesity. It stresses the importance of recognizing nutritional deficiencies, particularly copper deficiency, because of the possible and serious sequelae of bone marrow suppression and myeloneuropathy. The early recognition and treatment of the symptoms of hypocupremia is emphasized to avoid these long-term sequelae. With the rapidly growing number of patients undergoing gastrojejunal bypass surgery for morbid obesity, the index of suspicion for hypocupremia must be heightened.
Noise and the Evolution of Neural Network Modularity
Authors: Høverstad Boye Annfelt
Published: November 2010

We study the selective advantage of modularity in artificially evolved networks. Modularity abounds in complex systems in the real world. However, experimental evidence for the selective advantage of network modularity has been elusive unless it has been supported or mandated by the genetic representation. The evolutionary origin of modularity is thus still debated: whether networks are modular because of the process that created them, or the process has evolved to produce modular networks. It is commonly argued that network modularity is beneficial under noisy conditions, but experimental support for this is still very limited. In this article, we evolve nonlinear artificial neural network classifiers for a binary classification task with a modular structure. When noise is added to the edge weights of the networks, modular network topologies evolve, even without representational support.
Artificial Cybernetic Living Individuals Based on SupraMolecular-Level Organization as Dispersed Individuals
Authors: Korzeniewski Bernard
Published: November 2010

One of the most characteristic features of spontaneously originating biological systems is that their most fundamental structure and especially functioning is based on molecular-level organization. This property is particularly important when natural living individuals composed of organic compounds of carbon are compared with (hypothetical) artificial living individuals based on metals, plastic, glass, silicon, and so on, whose most basic structural and functional units appear at the supramolecular level. The cybernetic definition of a living individual I proposed previously is used in the present work. I argue that artificial, supramolecular living individuals existing self-dependently in the environment of some distant planet must have the form of dispersed individuals composed of several separate subindividuals that are integrated functionally, but not structurally. These subindividuals would be analogous to such modules of human technical civilization as machines, robots, steelworks, chemical plants, electronic factories, power stations, and mines. Such dispersed individuals would resemble colonies of social insects and moles, which are also composed of separate subindividuals (particular insects and moles) carrying out different specialized functions.
Twenty-ninth Annual Erasmus Birthday Lecture: Long and Useless: The Polemic between Erasmus and Béda
Authors: Rabbie Edwin
Published: November 2010

This essay investigates the background and printing history of the five works written between 1526 and 1529 that constitute Erasmus' polemic against the Parisian theologian Noël de Bède (Béda). Taken together, these polemical works are more voluminous than any others against his Roman Catholic adversaries. Unlike most of these other apologetic undertakings, moreover, this one concerns not Erasmus' edition of the New Testament but his Paraphrases.
The Lincoln Declaration on Drought Indices: Universal Meteorological Drought Index Recommended
Authors: Hayes Michael , Svoboda Mark , Wall Nicole , Widhalm Melissa
Published: November 2010

No Abstract available.
Estimating Drought Conditions for Regions with Limited Precipitation Data
Authors: Rhee Jinyoung , Carbone Gregory J.
Published: November 2010

Three closely related issues that affect drought estimation in regions with limited precipitation data are addressed by investigating methods for filling missing daily precipitation data, handling short-term records, and deriving drought information for unsampled locations. The analysis yields three general conclusions: 1) it is better to conduct spatial interpolation prior to calculating drought index values, 2) using weather stations with moderate lengths of records (usually at least 10 years) improves the spatial–temporal characterization of drought, and 3) alternative precipitation sources of the National Weather Service multisensor precipitation rainfall estimates and the Tropical Rainfall Measuring Mission (TRMM) satellite monthly rainfall product (3B43) do not outperform spatially interpolated daily precipitation data in most regions, except in the western United States where the TRMM-based precipitation data work better than the spatially interpolated values for drought monitoring.