bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensitivity of cells to apoptosis induced by iron deprivation can be reversibly changed by iron availability
Authors: Koc M. , Nad’ová Z. , Kovář J. 
Published: November 2006

Abstract.  We tested the effect of iron deprivation on cell death induction in human Raji cells pre‐adapted to differing availability of extracellular iron. Iron deprivation was achieved by incubation in a defined iron‐free medium. Original Raji cells have previously been adapted to long‐term culture in a defined medium with 5 µg/ml of iron‐saturated human transferrin as a source of iron. Raji/lowFe cells were derived from original Raji cells by subsequent adaptation to culture in the medium with 50 µm ferric citrate as a source of iron. Raji/lowFe‐re cells were derived from Raji/lowFe cells by re‐adaptation to the transferrin‐containing (5 µg/ml) medium. Iron deprivation induced cell death in both Raji cells and Raji/lowFe‐re cells; that is, cells pre‐adapted to a near optimum source of extracellular iron (5 µg/ml of transferrin). However, Raji/lowFe cells preadapted to a limited source of extracellular iron (50 µm ferric citrate) became resistant to the induction of cell death by iron deprivation. We demonstrated that cell death induction by iron deprivation in Raji cells correlates with the activation of executioner caspase‐3 and the cleavage of caspase‐3 substrate, poly‐ADP ribose polymerase. Two other executioner caspases, caspase‐7 and caspase‐6, were not activated. Taken together, we suggest that in human Raji cells, iron deprivation induces apoptotic cell death related to caspase‐3 activation. However, the sensitivity of the cells to death induction by iron deprivation can be reversibly changed by extracellular iron availability. The cells pre‐adapted to a limited source of extracellular iron became resistant.
γ‐Tocotrienol inhibits ErbB3‐dependent PI3K/Akt mitogenic signalling in neoplastic mammary epithelial cells
Authors: Samant G. V. , Sylvester P. W. 
Published: November 2006

Abstract.  The antiproliferative effects of γ‐tocotrienol are associated with suppression in epidermal growth factor (EGF)‐dependent phosphatidylinositol‐3‐kinase (PI3K)/PI3K‐dependent kinase‐1 (PDK‐1)/Akt mitogenic signalling in neoplastic mammary epithelial cells. Studies were conducted to investigate the direct effects of γ‐tocotrienol treatment on specific components within the PI3K/PDK‐1/Akt mitogenic pathway. +SA cells were grown in culture and maintained in serum‐free media containing 10 ng/ml EGF as a mitogen. Treatment with 0–8 µmγ‐tocotrienol resulted in a dose‐responsive decrease in the +SA cell growth and a corresponding decrease in phospho‐Akt (active) levels. However, γ‐tocotrienol treatment had no direct inhibitory effect on Akt or PI3K enzymatic activity, suggesting that the inhibitory effects of γ‐tocotrienol occur upstream of PI3K, possibly at the level of the EGF‐receptor (ErbB1). Additional studies were conducted to determine the effects of γ‐tocotrienol on ErbB receptor activation. Results showed that γ‐tocotrienol treatment had little or no effect on ErbB1 or ErbB2 receptor tyrosine phosphorylation, a prerequisite for substrate interaction and signal transduction, but did cause a significant and progressive decrease in the ErbB3 tyrosine phosphorylation. Because ErbB1 or ErbB2 receptors form heterodimers with the ErbB3 receptor, and ErbB3 heterodimers have been shown to be the most potent activators of PI3K, these findings strongly suggest that the antiproliferative effects of γ‐tocotrienol in neoplastic +SA mouse mammary epithelial cells are mediated by a suppression in ErbB3‐receptor tyrosine phosphorylation and subsequent reduction in PI3K/PDK‐1/Akt mitogenic signalling.
Present Status of Rinderpest Diseases in Pakistan
Authors: Matin M. A. , Rafi M. A. 
Published: November 2006

SummaryAll animal diseases have the potential to affect human lives adversely by reducing the quantity and/or quality of food (meat, milk, etc.), secondary livestock products (hides, skins and fibres) and animal power (traction and transport). The importance of the livestock sector is growing more rapidly than any other agricultural sector in Pakistan. In the past, livestock production in Pakistan has been affected because of transboundary animal diseases like rinderpest, foot and mouth disease and peste des petits ruminants disease, posing a serious threat to the livestock industry in Pakistan. The continuing persistence of rinderpest has been of grave concern for the entire region including Pakistan. The export of livestock products managed to retain its growth with relaxation of restrictions imposed by the Gulf states in the year 2001 only. Pakistan has been provisionally declared a rinderpest free country in 2003, as a result of a vigorous eradication programme.
Effects of hydrogen charge on microscopic fatigue behaviour of annealed carbon steels
Authors: UYAMA H. , NAKASHIMA M. , MORISHIGE K. , MINE Y. , MURAKAMI Y. 
Published: November 2006

ABSTRACTThe effects of hydrogen charge on cyclic stress–strain properties, slip band morphology and crack behaviour of annealed medium carbon steels (JIS‐S45C) were studied. The total strain range of the stress–strain hysteresis loop in the hydrogen‐charged specimen was smaller than that in the uncharged specimen. Localized slip bands were observed in the hydrogen‐charged specimen, while the slip bands were widely and uniformly distributed in the uncharged specimen. It is presumed that the decrease in the total strain range of the hysteresis loop is due to the slip localization caused by the hydrogen charge and cyclic loading. The sites of fatigue crack initiation were mostly at grain boundaries in the uncharged specimen. The sites of crack initiation in the hydrogen‐charged specimen were not only at grain boundaries but also at slip bands inside ferrite grains. These results imply that hydrogen enhances dislocation mobility along slip bands and results in slip localization. These slip bands then attract hydrogen. This mechanism of hydrogen–slip band interaction may play an important role in the hydrogen‐influenced metal fatigue.
The Relationship Between the Recognition of Facial Expressions and Self‐Reported Anger in People with Intellectual Disabilities
Authors: Woodcock Kate A. , Rose John 
Published: November 2006

Background  This study aims to examine the relationship between how individuals with intellectual disabilities report their own levels of anger, and the ability of those individuals to recognize emotions. It was hypothesized that increased expression of anger would be linked to lower ability to recognize facial emotional expressions and increased tendency to interpret facial expressions in a hostile or negative manner. It was also hypothesized increased levels of anger may lead to the altered perception of a particular emotion.Method  A cross‐sectional survey design was used. Thirty participants completed a test of facial emotion recognition (FER), and a self‐report anger inventory (Benson & Ivins 1992) as part of a structured interview.Results  Individuals with higher self‐reported anger did not show significantly reduced performance in FER, or interpret facial expressions in a more hostile manner compared with individuals with less self‐reported anger. However, they were less accurate in recognizing neutral facial emotions.Conclusions  It is tentatively suggested that individuals with high levels of anger may be likely to perceive emotional content in a neutral facial expression because of their high levels of emotional arousal.
Microvascular growth of 7,12‐dimethylbenz(α)anthracene‐induced adenocarcinomas in rats: histology and scanning electron microscopy of resin casts
Authors: Ninomiya H. , Inomata T. , Yoshida S. 
Published: November 2006

AbstractVascular changes at various stages of growth of 7,12‐dimethylbenz(α)anthracene (DMBA)‐induced mammary adenocarcinomas in 22 female Sprague‐Dawley rats were investigated using histology, immunohistochemistry and scanning electron microscopy (SEM) of corrosion casts. In the early stage of tumour growth, capillaries within the neoplasms were thin, with 8–10 μm diameter, and characterized by rows of vascular sprouts representing extensive neovascularization and formation of a high‐density capillary plexus. In the intermediate stage of tumour growth, the growing tumour was multi‐nodular and tumour cells were arranged in a tubulopapillary pattern. Capillaries formed spheroid vascular capsules and were characterized by dilation, to a diameter of 10–80 μm, and blind ends. In the late stage of tumour growth, a remarkable reduction in the number of vascular endothelial growth factor‐positive cells and Ki‐67‐stained nuclei was demonstrated. The tunica media of nutritive arteries displayed a tendency to atrophy. Many arteriovenous anastomoses between the major arteries and the veins were found in regions just before their entry into the tumour. The central regions of the tumour were degenerative and necrotic, and vasculature was confined to surface regions of the tumour, forming a basket‐like configuration around the avascular central regions. Resin leakages representing haemorrhage or oedema and distortions such as flattening, break‐off and strangulations of capillaries were frequently observed, all of which are known as late tumour signs. We concluded that these microvascular alterations might change the homogeneity of tumour perfusion and contribute to necrosis in central portions of the tumour.
Left Out: Trust and Social Capital Among Migrant Seasonal Farmworkers*
Authors: Chávez Maria L. , Wampler Brian , Burkhart Ross E. 
Published: November 2006

Objectives. We analyze the levels of trust and social capital among an understudied group: migrant seasonal farmworkers (MSFW). MSFWs of today are likely to become the “Hispanics” of tomorrow, which means that understanding what affects the development of social capital of this group is critical to understanding how these individuals are incorporated—or not—into the U.S. polity.Methods. We utilize logistic regression analysis and ordered logit analysis to analyze a data set of 555 MSFWs and comments from four focus groups in Idaho.Results. We find that MSFWs have lower levels of generalized trust than do Hispanics nationally. We also find that MSFWs have low levels of trust toward whites and Mexican Americans.Conclusions. We argue that an ethnic community's subgroups must be incorporated into our analysis of social capital, especially when these individuals are likely to become U.S. permanent residents or citizens.
Cholesterol-Depleting Statin Drugs Protect Postmitotically Differentiated Human Neurons against Ethanol- and Human Immunodeficiency Virus Type 1-Induced Oxidative Stress In Vitro
Authors: Acheampong Edward , Parveen Zahida , Mengistu Aschalew , Ngoubilly Noel , Wigdahl Brian , Lossinsky Albert S. , Pomerantz Roger J. , Mukhtar Muhammad 
Published: November 2006

ABSTRACTThe majority of human immunodeficiency virus type 1 (HIV-1)-infected individuals are either alcoholics or prone to alcoholism. Upon ingestion, alcohol is easily distributed into the various compartments of the body, particularly the brain, by crossing through the blood-brain barrier. Both HIV-1 and alcohol induce oxidative stress, which is considered a precursor for cytotoxic responses. Several reports have suggested that statins exert antioxidant as well as anti-inflammatory pleiotropic effects, besides their inherent cholesterol-depleting potentials. In our studies, postmitotically differentiated neurons were cocultured with HIV-1-infected monocytes, T cells, or their cellular supernatants in the presence of physiological concentrations of alcohol for 72 h. Parallel cultures were pretreated with statins (atorvastatin and simvastatin) with the appropriate controls, i.e., postmitotically differentiated neurons cocultured with uninfected cells and similar cultures treated with alcohol. The oxidative stress responses in the presence/absence of alcohol in these cultures were determined by the production of the well-characterized oxidative stress markers, 8-isoprostane-F2-α, total nitrates as an indicator for various isoforms of nitric oxide synthase activity, and heat shock protein 70 (Hsp70). An in vitro culture of postmitotically differentiated neurons with HIV-1-infected monocytes or T cells as well as supernatants from these cells enhanced the release of 8-isoprostane-F2-α in the conditioned medium six- to sevenfold (monocytes) and four- to fivefold (T cells). It was also observed that coculturing of HIV-1-infected primary monocytes over a time period of 72 h significantly elevated the release of Hsp70 compared with that of uninfected controls. Cellular supernatants of HIV-1-infected monocytes or T cells slightly increased Hsp70 levels compared to neurons cultured with uninfected monocytes or T-cell supernatants (controls). Ethanol (EtOH) presence further elevated Hsp70 in both infected and uninfected cultures. The amount of total nitrates was significantly elevated in the coculture system when both infected cells and EtOH were present. Surprisingly, pretreatment of postmitotic neurons with clinically available inhibitors of HMG-coenzyme A reductase (statins) inhibited HIV-1-induced release of stress/toxicity-associated parameters, i.e., Hsp70, isoprostanes, and total nitrates from HIV-1-infected cells. The results of this study provide new insights into HIV-1 neuropathogenesis aimed at the development of future HIV-1 therapeutics to eradicate viral reservoirs from the brain.
Structure-Based Identification of a Major Neutralizing Site in an Adenovirus Hexon
Authors: Pichla-Gollon Susan L. , Drinker Mark , Zhou Xiangyang , Xue Feng , Rux John J. , Gao Guang-Ping , Wilson James M. , Ertl Hildegund C. J. , Burnett Roger M. , Bergelson Jeffrey M. 
Published: November 2006

ABSTRACTVirus-specific neutralizing antibodies present an obstacle to the effective use of adenovirus vectors for gene therapy and vaccination. The specific sites recognized by neutralizing antibodies have not been identified for any adenovirus, but they have been proposed to reside within the hexon, in small regions of the molecule that are exposed on the capsid surface and possess sequences that vary among serotypes. We have mapped the epitopes recognized by a panel of seven hexon-specific monoclonal antibodies that neutralize the chimpanzee adenovirus 68 (AdC68). Surface plasmon resonance experiments revealed that the antibodies compete for a single hexon binding site, and experiments with synthetic peptides indicated that this site resides within just one small surface loop. Mutations within this loop (but not in other surface loops) permitted virus to escape neutralization by all seven monoclonal antibodies and to resist neutralization by polyclonal antisera obtained from animals immunized against AdC68. These results indicate that a single small surface loop defines a major neutralization site for AdC68 hexon.
Selective Restriction of Nef-Defective Human Immunodeficiency Virus Type 1 by a Proteasome-Dependent Mechanism
Authors: Qi Mingli , Aiken Christopher 
Published: November 2006

ABSTRACT
The Nef protein enhances human immunodeficiency virus type 1 (HIV-1) infectivity by facilitating an early postentry step in the virus life cycle. We report here that the addition of MG132 or lactacystin, each a specific inhibitor of cellular proteasome activity, preferentially enhances cellular permissiveness to infection by Nef-defective versus wild-type HIV-1. Pseudotyping by the glycoprotein of vesicular stomatitis virus rendered Nef-defective HIV-1 particles minimally responsive to the enhancing effects of proteasome inhibitors. These results suggest that Nef enhances the infectivity of HIV-1 particles by reducing their susceptibility to proteasomal degradation in target cells.
LKB1 Is Recruited to the p21/WAF1 Promoter by p53 to Mediate Transcriptional Activation
Authors: Zeng Ping-Yao , Berger Shelley L. 
Published: November 2006

Abstract
The tumor suppressor LKB1 is an evolutionarily conserved serine/threonine kinase. In humans, LKB1 can be inactivated either by germ-line mutations resulting in Peutz-Jeghers syndrome or by somatic mutations causing predisposition to multiple sporadic cancers. LKB1 has wide-ranging functions involved in tumor suppression and cell homeostasis, including establishing cell polarity, setting energy metabolic balance (via phosphorylation of AMP-dependent kinase), regulating the cell cycle, and promoting apoptosis. LKB1 function was previously linked to the tumor suppressor p53 and shown to activate the p53 target gene p21/WAF1. In this study, we further investigated LKB1 activation of the p21/WAF1 gene and addressed whether LKB1 is directly involved at the gene promoter. We find that, consistent with previous studies, LKB1 stabilizes p53 in vivo, correlating with activation of p21/WAF1. We show that LKB1 physically associates with p53 in the nucleus and directly or indirectly phosphorylates p53 Ser15 (previously shown to be phosphorylated by AMP-dependent kinase) and p53 Ser392. Further, these two p53 residues are required for LKB1-dependent cell cycle G1 arrest. Chromatin immunoprecipitation analyses show that LKB1 is recruited directly to the p21/WAF1 promoter, as well as to other p53 activated promoters, in a p53-dependent fashion. Finally, a genetic fusion of LKB1 to defective p53, deleted for its activation domains, promotes activation of p21/WAF1. These results indicate that LKB1 has a direct role in activation of p21/WAF1 gene. (Cancer Res 2006; 66(22): 10701-8)
Osteoclasts Direct Bystander Killing of Bone Cancer
Authors: Ramnaraine Margaret L. , Mathews Wendy E. , Donohue James M. , Lynch Christine M. , Goblirsch Michael J. , Clohisy Denis R. 
Published: November 2006

Abstract
Primary and metastatic bone cancers are difficult to eradicate and novel approaches are needed to improve treatment and extend life. As bone cancer grows, osteoclasts, the principal bone-resorbing cells of the body, are recruited to and activated at sites of cancer. In this investigation, we determined if osteoclast lineage cells could function as a cell-based gene delivery system to bone cancers. We used the cytosine deaminase (CD) 5-fluorocytosine (5-FC) enzyme/prodrug system and studied bone marrow and bones from transgenic mice expressing a novel CD gene regulated by the osteoclast tartrate-resistant acid phosphatase (TRAP) gene promoter (Tg/NCD). DsRed2-labeled 2472 sarcoma cells were placed in Tg/NCD osteoclastogenic cultures and treated with 5-FC. 5-FC treatment resulted in profound bystander killing (90%; P &lt; 0.05). The effect of 5-FC treatment on osteoclast lineage cells was most dramatic when administered at the beginning of the 7-day cultures, suggesting that mature osteoclasts are less sensitive to 5-FC. Evaluation of osteoclast-directed bystander killing in vivo revealed dramatic killing of bone cancer with only a modest effect on osteoclast number. Specifically, 5-FC treatment of tumor-bearing Tg/NCD mice or Tg/NCD bone marrow transplanted C3H mice (Tg/NCD-C3H) resulted in 92% and 44% reductions in tumor area, respectively (P &lt; 0.05). Eight of ten 5-FC-treated Tg/NCD mice had complete bone tumor killing and five of six 5-FC-treated Tg/NCD-C3H mice had reduced tumor compared with controls. In addition, Tg/NCD osteoclasts were resistant to 5-FC treatment in vivo, a very important feature, as it identifies osteoclasts as an ideal CD gene delivery system. (Cancer Res 2006; 66(22): 10929-35)
In vivo Activity of the Cleaved Form of Soluble Urokinase Receptor: A New Hematopoietic Stem/Progenitor Cell Mobilizer
Authors: Selleri Carmine , Montuori Nunzia , Ricci Patrizia , Visconte Valeria , Baiano Antonio , Carriero Maria Vincenza , Rotoli Bruno , Rossi Guido , Ragno Pia 
Published: November 2006

Abstract
Cleaved forms of soluble urokinase receptor (c-suPAR) have been detected in body fluids from patients affected by various tumors. We recently reported increased c-suPAR levels in sera of healthy donors during granulocyte colony-stimulating factor (G-CSF)–induced mobilization of CD34+ hematopoietic stem cells (HSC). In vitro, c-suPAR or its derived chemotactic peptide (uPAR84-95) stimulated migration of human CD34+ HSCs and inactivated CXCR4, the chemokine receptor primarily responsible for HSC retention in bone marrow. These results suggested that c-suPAR could potentially contribute to regulate HSC trafficking from and to bone marrow. Therefore, we investigated uPAR84-95 effects on mobilization of mouse CD34+ hematopoietic stem/progenitor cells (HSC/HPC). We first showed that uPAR84-95 stimulated in vitro dose-dependent migration of mouse CD34+ M1 leukemia cells and inactivated murine CXCR4. uPAR84-95 capability to induce mouse HSC/HPC release from bone marrow and migration into the circulation was then investigated in vivo. uPAR84-95 i.p. administration induced rapid leukocytosis, which was associated with an increase in peripheral blood CD34+ HSCs/HPCs. In vitro colony assays confirmed that uPAR84-95 mobilized hematopoietic progenitors, showing an absolute increase in circulating colony-forming cells. uPAR84-95 mobilizing activity was comparable to that of G-CSF; however, neither synergistic nor additive effect was observed in combining the two molecules. These findings show for the first time in vivo biological effects of c-suPAR. Its capability to mobilize HSCs suggests potential clinical applications in HSC transplantation. (Cancer Res 2006; 66(22): 10885-90)
Chemiphoresis of montmorillonite particles
Authors: Helmy A. K. , Natale I. M. , Mandolesi M. E. , Santamaria R. M. 
Published: November 2006

AbstractThe chemiphoresis of montmorillonite saturated with Na, K, Li or Ca was studied in a system where corrosive dissolution of Al, Fe, Zn or Cu metal plates took place in the presence of HF and H2O2. The deposition of the clay as well as metal dissolution were found to be a function of indicating that the electrochemical reaction is controlled principally by diffusion of the reacting species to the metal-liquid interface. The deposition increased with clay concentration and was lower for Ca-clay than for Na-, K- or Li-clay. It is shown that chemiphoresis alone does not provide sufficient data for the calculation of particle mobility and that other types of measurement are necessary. A relationship between particle deposition and electrical conductivity was developed, and examined experimentally with satisfactory results.