bluuebunny/crossref_metadata_2025 huggingface dataset:
Conservation and Divergence in Cellulosome Architecture between Two Strains ofRuminococcus flavefaciens
Authors: Jindou Sadanari , Borovok Ilya , Rincon Marco T. , Flint Harry J. , Antonopoulos Dionysios A. , Berg Margret E. , White Bryan A. , Bayer Edward A. , Lamed Raphael
Published: November 2006

A 17-kb scaffoldin gene cluster inRuminococcus flavefaciensstrain FD-1 was compared with the homologous segment published for strain 17. Although the general design of the cluster is identical in the two strains, significant differences in the modular architecture of the scaffoldin proteins were discovered, implying strain-specific divergence in cellulosome organization.
Interplay between human papilloma virus infection andp53gene alterations in head and neck squamous cell carcinoma of an Indian patient population
Authors: Mitra S , Banerjee S , Misra C , Singh R K , Roy A , Sengupta A , Panda C K , Roychoudhury S
Published: November 2006

Aim:To investigate the complex interplay between human papilloma virus (HPV) infection andp53gene alteration in 92 head and neck squamous cell carcinoma (HNSCC) and 28 leukoplakia samples from eastern India.

Methods:DNA isolated from the patient samples was subjected to HPV detection, loss of heterozygosity (LOH) analysis of the chromosome 17p region harbouringp53, genotyping at thep53codon 72 locus and sequencing of the entirep53gene to identify somatic mutations. Codon 72 heterozygotes carrying thep53mutation were further cloned and resequenced to identify the allele harbouring the mutation.

Results:HPV positivity in the HNSCC samples was 69%; 21% of the HNSCC were found to harbourp53mutations in the coding region of the gene. The absence of thep53mutation in HPV positive tumours was statistically significant compared to the HPV negative tumours (p = 0.01), but the same did not hold true forp53LOH (p = 1.0). Among the germlinep53codon 72 heterozygotes, the Pro allele was preferentially lost (p = 0.02) while the Arg allele was mutated in the majority of cases. The risk of HPV mediated tumourigenesis increased with the increase in number of Arg alleles at the codon 72 locus.

Conclusion:It is proposed that genetic and epigenetic alteration ofp53follow distinct pathways during the development of HNSCC from normal epithelium via dysplasia. Thep53mutation and HPV mediated p53 inactivation possibly constitute two independent pathways of tumourigenesis.
Lymphatic vascular density and lymphangiogenesis during tumour progression of carcinoma ex pleomorphic adenoma
Authors: Soares A B , Ponchio L , Juliano P B , de Araújo V C , Altemani A
Published: November 2006

Aims:To assess lymphatic vascular density (LVD) and lymph vessel endothelial proliferation in a series of carcinoma ex pleomorphic adenoma (CXPA) that represents the tumour in the different carcinogenesis phases and tumour progression.

Methods:In 8 cases of early CXPA (intracapsular and minimally invasive tumours), 8 of advanced CXPA (widely invasive tumours) and 10 of pleomorphic adenoma (PA) without malignant transformation, lymphatic vessels and proliferating cells were detected using the antibodies D2-40 and Ki-67 respectively.

Results:Comparing early tumours with advanced ones, LVD was not significantly different at the tumour margin. In contrast, regarding intratumoural lymphatics, PA without malignant transformation and early CXPA contained rare, if any, lymph vessels, whereas in widely invasive carcinomas they were more numerous. However, neither intratumoural nor peritumoural LVD were increased in comparison to adjacent normal salivary gland tissue. In no case did dual immunohistochemistry using D2-40 and the cell proliferation marker Ki-67 reveal the existence of proliferating lymphatics. Carcinomatous emboli were found in peritumoural as well as in intratumoural lymphatics only in advanced CXPA without myoepithelial differentiation.

Conclusion:In CXPA, the lymphatic network is mainly composed of pre-existing lymphatics which are rare in tumours that have not infiltrated outside the confines of the original PA. In the widely invasive CXPA, intratumoural as well as peritumoural lymphatics are a conduit for carcinoma cells, but in carcinomas with myoepithelial differentiation, the neoplastic cells seem to have a lower invasion capacity.
S-BAND BRILLOUIN/ERBIUM FIBER LASER FOR DWDM APPLICATION
Authors: HARUN SULAIMAN WADI , SAN CHENG XIAU , AHMAD HARITH
Published: November 2006

A multi-wavelength Brillouin erbium fiber laser (BEFL) which operates in a short wavelength band (S-Band) is demonstrated using a depressed cladding erbium-doped fiber (EDF). Two 80/20 couplers were used in the system for internal feedback of generated stokes signal in order to produce cascaded Brillouin stokes for multi-wavelength operation. It generates an optical wavelength comb with spacing of approximately 0.084 m. A stable output laser of up to 7 lines was obtained with a Brillouin pump of 3.5 mW, a 980 nm pump laser of 200 mW and an EDF length of 20 m. The BEFL has the potential to be used in the future dense wavelength division multiplexing (DWDM) communication system.
Phosphorylation of SIMPL modulates RelA-associated NF-κB-dependent transcription
Authors: Luo Yong , Kwon Hyung-Joo , Montano Sherwin , Georgiadis Millie , Goebl Mark G. , Harrington Maureen A.
Published: November 2006

Epidemiological data have implicated perturbations in the regulation of NF-κB activity to diseases that affect a large number of Americans today. Specifically, chronic activation of genes involved in the inflammatory response is associated with the progression of and complications in diabetes, arthritis, atherosclerosis, and cancer. Insight into the mechanisms governing the regulation of NF-κB transcriptional activity will provide the molecular link between NF-κB and these pathological states. SIMPL (signaling molecule that associates with mouse Pelle-like kinase) is a component of a signaling pathway through which tumor necrosis factor-α (TNF-α) induces NF-κB-controlled gene transcription. SIMPL interacts with the nuclear pool of the NF-κB subunit, p65, in a TNF-α-dependent manner to enhance p65-dependent gene transcription. How SIMPL activity is regulated is unknown. Under basal as well as TNF-α-stimulated conditions, SIMPL phosphopeptides were identified. SIMPL mutants lacking sites that are phosphorylated under basal conditions diminished p65 transactivation activity but had no effect on SIMPL nuclear localization. SIMPL mutants lacking sites of TNF-α-enhanced phosphorylation impaired nuclear localization and prevented TNF-α-induced p65 transactivation activity. Together, these studies reveal that phosphorylation of the SIMPL protein plays a critical role in SIMPL regulation by affecting both SIMPL subcellular localization and the p65 coactivator function of SIMPL.
Endogenous cholecystokinin reduces food intake and increases Fos-like immunoreactivity in the dorsal vagal complex but not in the myenteric plexus by CCK1 receptor in the adult rat
Authors: Sullivan Cherese N. , Raboin Shannon J. , Gulley Stephen , Sinzobahamvya Ntwenzi T. , Green Gary M. , Reeve Joseph R. , Sayegh Ayman I.
Published: November 2006

We hypothesized that endogenous CCK reduces food intake by activating the dorsal vagal complex (DVC) and the myenteric neurons of the gut. To test this hypothesis, adult rats were given camostat mesilate; a nonnutrient releaser of endogenous CCK, by orogastric gavage, and Fos-like immunoreactivity (Fos-LI) was quantified in the DVC and the myenteric plexus. The results for endogenous CCK were compared with those for exogenous CCK-8. Exogenous CCK-8 reduced food intake and stimulated Fos-LI in the DVC and in myenteric neurons of the duodenum and jejunum. In comparison, endogenous CCK reduced food intake and increased DVC Fos-LI but did not increase Fos-LI in the myenteric plexus. Similar to CCK-8, devazepide, a specific CCK1 receptor antagonist, and not L365,260, a specific CCK2 receptor antagonist, attenuated the reduction of food intake by camostat. In addition, Fos-LI in the DVC in response to both exogenous CCK-8 and camostat administration was significantly attenuated by vagotomy, as well as by blocking CCK1 receptors. These results demonstrate for the first time that reduction of food intake in adult rats by endogenous CCK released by a nonnutrient mechanism requires CCK1 receptors, the vagus nerve, and activation of the DVC, but not the myenteric plexus.
A Simple Depletion Model of the Readily Releasable Pool of Synaptic Vesicles Cannot Account for Paired-Pulse Depression
Authors: Sullivan Jane M.
Published: November 2006

Paired-pulse depression (PPD) is a form of short-term plasticity that plays a central role in processing of synaptic activity and is manifest as a decrease in the size of the response to the second of two closely timed stimuli. Despite mounting evidence to the contrary, PPD is still commonly thought to reflect depletion of the pool of synaptic vesicles available for release in response to the second stimulus. Here it is shown that PPD cannot be accounted for by depletion at excitatory synapses made by hippocampal neurons because PPD is unaffected by changes in the fraction of the readily releasable pool (RRP) released by the first of a pair of pulses.
Asymptotic behavior of a class of nonlinear difference equations
Authors: Stevic Stevo
Published: November 2006

Motivated by some results of L. Berg (2002),
in this paper we find the second member in the asymptotic
development of some of the positive solutions of a class of difference equations
of second and third orders. The main result in this paper partially
solves an open problem by S. Stević (2003), and it is applied to some classes of mathematical biology models,
for example, generalized Beverton‐Holt stock recruitment model, flour
beetle population model, mosquito population equations, and discrete delay
logistic difference equation.
Nonlinear elliptic problems with the method of finite volumes
Authors: Khattri Sanjay Kumar
Published: November 2006

We present a finite volume discretization of the nonlinear
elliptic problems. The discretization results in a nonlinear
algebraic system of equations. A Newton‐Krylov algorithm is also
presented for solving the system of nonlinear algebraic
equations. Numerically solving nonlinear partial differential
equations consists of discretizing the nonlinear partial
differential equation and then solving the formed nonlinear
system of equations. We demonstrate the convergence of the
discretization scheme and also the convergence of the Newton
solver through a variety of practical numerical examples.
On a similarity solution of MHD boundary layer flow over a moving vertical cylinder
Authors: Amkadni Maryem , Azzouzi Adnane
Published: November 2006

The steady flow of an incompressible electrically conducting
fluid over a semi‐infinite moving vertical cylinder in the
presence of a uniform transverse magnetic field is analyzed. The
partial differential equations governing the flow are reduced to
an ordinary differential equation, using the self‐similarity
transformation. The analysis deals with the existence of an exact
solution to the boundary value problem by a shooting method.
Prospects for Cervical Cancer Prevention by Human Papillomavirus Vaccination
Authors: Schiller John T. , Lowy Douglas R.
Published: November 2006

Recent clinical trials in young women have shown that subunit vaccines based on human papillomavirus (HPV) 16 and HPV18 L1 virus-like particles are ∼100% effective in short-term prevention of persistent cervical infection and of cervical dysplasia by these major oncogenic types. These remarkable efficacy results, together with an excellent safety profile in thousands of vaccinated women, have led to the HPV prophylactic vaccine from one manufacturer having now been licensed for commercial use and the expectation that the vaccine from a second manufacturer will be approved in the near future. These vaccines seem to have great potential for reducing cervical cancer deaths and treatments to remove premalignant cervical lesions. However, before their public health effect can be fully estimated, several issues must be addressed. These include duration of protection, degree of cross-protection against nonvaccine types, efficacy in men, and vaccine availability to economically disadvantaged women. (Cancer Res 2006; 66(21): 10229-32)
Ephrin-A1 Facilitates Mammary Tumor Metastasis through an Angiogenesis-Dependent Mechanism Mediated by EphA Receptor and Vascular Endothelial Growth Factor in Mice
Authors: Brantley-Sieders Dana M. , Fang Wei Bin , Hwang Yoonha , Hicks Donna , Chen Jin
Published: November 2006

Ephrin-A1, the prototypic ligand for EphA receptor tyrosine kinases, is overexpressed in vascularized tumors relative to normal tissue. Moreover, ephrin-A1-Fc fusion proteins induce endothelial cell sprouting, migration, and assembly in vitro, and s.c. vascular remodeling in vivo. Based on these data, we hypothesized that native, membrane-bound ephrin-A1 regulates tumor angiogenesis and progression. We tested this hypothesis using a transplantable mouse mammary tumor model. Small interfering RNA–mediated ephrin-A1 knockdown in metastatic mammary tumor cells significantly diminishes lung metastasis without affecting tumor volume, invasion, intravasation, or lung colonization upon i.v. injection in vivo. Ephrin-A1 knockdown reduced tumor-induced endothelial cell migration in vitro and microvascular density in vivo. Conversely, overexpression of ephrin-A1 in nonmetastatic mammary tumor cells elevated microvascular density and vascular recruitment. Overexpression of ephrin-A1 elevated wild-type but not EphA2-deficient endothelial cell migration toward tumor cells, suggesting that activation of EphA2 on endothelial cells is one mechanism by which ephrin-A1 regulates angiogenesis. Furthermore, ephrin-A1 knockdown diminished, whereas overexpression of ephrin-A1 elevated, vascular endothelial growth factor (VEGF) levels in tumor cell–conditioned medium, suggesting that ephrin-A1–mediated modulation of the VEGF pathway is another mechanism by which membrane-tethered ephrin-A1 regulates angiogenic responses from initially distant host endothelium. These data suggest that ephrin-A1 is a proangiogenic signal, regulating VEGF expression and facilitating angiogenesis-dependent metastatic spread. (Cancer Res 2006; 66(21): 10315-24)
Receptor-Mediated DNA-Targeted Photoimmunotherapy
Authors: Karagiannis Tom C. , Lobachevsky Pavel N. , Leung Brenda K.Y. , White Jonathan M. , Martin Roger F.
Published: November 2006

We show the efficacy of a therapeutic strategy that combines the potency of a DNA-binding photosensitizer, UVASens, with the tumor-targeting potential of receptor-mediated endocytosis. The photosensitizer is an iodinated bibenzimidazole, which, when bound in the minor groove of DNA and excited by UVA irradiation, induces cytotoxic lesions attributed to a radical species resulting from photodehalogenation. Although reminiscent of photochemotherapy using psoralens and UVA irradiation, an established treatment modality in dermatology particularly for the treatment of psoriasis and cutaneous T-cell lymphoma, a critical difference is the extreme photopotency of the iodinated bibenzimidazole, ∼1,000-fold that of psoralens. This feature prompted consideration of combination with the specificity of receptor-mediated targeting. Using two in vitro model systems, we show the UVA cytotoxicity of iodo ligand/protein conjugates, implying binding of the conjugate to cell receptors, internalization, and degradation of the conjugate-receptor complex, with release and translocation of the ligand to nuclear DNA. For ligand-transferrin conjugates, phototoxicity was inhibited by coincubation with excess native transferrin. Receptor-mediated UVA-induced cytotoxicity was also shown with the iodo ligand conjugate of an anti-human epidermal growth factor receptor monoclonal antibody, exemplifying the potential application of the strategy to other cancer-specific targets to thus improve the specificity of phototherapy of superficial lesions and for extracorporeal treatments. (Cancer Res 2006; 66(21): 10548-52)
Eradication of Tumor Colonization and Invasion by a B Cell–Specific Immunotoxin in a Murine Model for Human Primary Intraocular Lymphoma
Authors: Li Zhuqing , Mahesh Sankaranarayana P. , Shen De Fen , Liu Baoying , Siu Willie O. , Hwang Frank S. , Wang Qing-Chen , Chan Chi-Chao , Pastan Ira , Nussenblatt Robert B.
Published: November 2006

Human primary intraocular lymphoma (PIOL) is predominantly a B cell–originated malignant disease with no appropriate animal models and effective therapies available. This study aimed to establish a mouse model to closely mimic human B-cell PIOL and to test the therapeutic potential of a recently developed immunotoxin targeting human B-cell lymphomas. Human B-cell lymphoma cells were intravitreally injected into severe combined immunodeficient mice. The resemblance of this tumor model to human PIOL was examined by fundoscopy, histopathology, immunohistochemistry, and evaluated for molecular markers. The therapeutic effectiveness of immunotoxin HA22 was tested by injecting the drug intravitreally. Results showed that the murine model resembles human PIOL closely. Pathologic examination revealed that the tumor cells initially colonized on the retinal surface, followed by infiltrating through the retinal layers, expanding preferentially in the subretinal space, and eventually penetrating through the retinal pigment epithelium into the choroid. Several putative molecular markers for human PIOL were expressed in vivo in this model. Tumor metastasis into the central nervous system was also observed. A single intravitreal injection of immunotoxin HA22 after the establishment of the PIOL resulted in complete regression of the tumor. This is the first report of a murine model that closely mimics human B-cell PIOL. This model may be a valuable tool in understanding the molecular pathogenesis of human PIOL and for the evaluation of new therapeutic approaches. The results of B cell–specific immunotoxin therapy may have clinical implications in treating human PIOL. (Cancer Res 2006; 66(21): 10586-93)
Aromatase Destabilizer: Novel Action of Exemestane, a Food and Drug Administration–Approved Aromatase Inhibitor
Authors: Wang Xin , Chen Shiuan
Published: November 2006

Using Western blot as the major technique, we studied the effects of the three Food and Drug Administration (FDA)–approved aromatase inhibitors (AI) on aromatase protein stability in the aromatase-overexpressing breast cancer cell line MCF-7aro. We have found that exemestane treatment significantly reduces aromatase protein level. Exemestane induces aromatase degradation in a dose-responsive manner (25-200 nmol/L), and the effect can be seen in as early as 2 hours. Metabolic labeling with S35-methionine was used to determine the half-life (t1/2) of aromatase protein. In the presence of 200 nmol/L exemestane, the t1/2 of aromatase was reduced to 12.5 hours from 28.2 hours in the untreated cells. Furthermore, exemestane-induced aromatase degradation can be completely blocked by 10 μmol/L MG132, indicating that the degradation is mediated by proteasome. We also examined the effect of exemestane on aromatase mRNA level using real-time reverse transcription-PCR. No significant changes in mRNA level were detected after 8 hours of treatment with exemestane (200 nmol/L). This is the first report on the evaluation of three FDA-approved AIs on the stability of the aromatase protein. We have found that exemestane, different from letrozole and anastrozole, can destabilize the aromatase protein. (Cancer Res 2006; 66(21): 10281-6)
Retinoblastoma Pathway Defects Show Differential Ability to Activate the Constitutive DNA Damage Response in Human Tumorigenesis
Authors: Tort Frederic , Bartkova Jirina , Sehested Maxwell , Ørntoft Torben , Lukas Jiri , Bartek Jiri
Published: November 2006

Loss of G1-S control and aberrations of the p16Ink4a-cyclin D1/cyclin-dependent kinase (CDK) 4(6)-pRb-E2F-cyclin E/CDK2 pathway are common in human cancer. Previous studies showed that oncogene-induced aberrant proliferation, such as on cyclin E overexpression, causes DNA damage and checkpoint activation. Here, we show that, in a series of human colorectal adenomas, those with deregulation of cyclin D1 and/or p16Ink4a showed little evidence of constitutive DNA damage response (DDR), contrary to cyclin E-overexpressing higher-grade cases. These observations were consistent with diverse cell culture models with differential defects of retinoblastoma pathway components, as overexpression of cyclin D1 or lack of p16Ink4a, either alone or combined, did not elicit detectable DDR. In contrast, inactivation of pRb, the key component of the pathway, activated the DDR in cultured human or mouse cells, analogous to elevated cyclin E. These results highlight differential effect of diverse oncogenic events on driving the ‘cancer cell cycles’ and their ability to deregulate the replication-driving CDK2 kinase and to alarm the DDR as a potential anticancer barrier in accordance with their hierarchical positions along the retinoblastoma pathway. Our data provide new insights into oncogene-evoked DDR in human tumorigenesis, with potential implications for individualized management of tumors with elevated cyclin D1 versus cyclin E, due to their distinct clinical variables and biological behavior. (Cancer Res 2006; 66(21): 10258-63)
Expression of Wnt-5a Is Correlated with Aggressiveness of Gastric Cancer by Stimulating Cell Migration and Invasion
Authors: Kurayoshi Manabu , Oue Naohide , Yamamoto Hideki , Kishida Michiko , Inoue Atsuko , Asahara Toshimasa , Yasui Wataru , Kikuchi Akira
Published: November 2006

Wnt-5a is a representative ligand that activates a β-catenin-independent pathway in the Wnt signaling. Although abnormal activation of β-catenin-dependent pathway is often observed in human cancer, the relationship between β-catenin-independent pathway and tumorigenesis is not clear. We sought to clarify how Wnt-5a is involved in aggressiveness of gastric cancer. Abnormal expression of Wnt-5a was observed in 71 of 237 gastric cancer cases by means of immunohistochemistry. The positivity of Wnt-5a expression was correlated with advanced stages and poor prognosis of gastric cancer. Wnt-5a had the abilities to stimulate cell migration and invasion in gastric cancer cells. Wnt-5a activated focal adhesion kinase and small GTP-binding protein Rac, both of which are known to play a role in cell migration. Cell migration, membrane ruffling, and turnover of paxillin were suppressed in Wnt-5a knockdown cells. Furthermore, anti-Wnt-5a antibody suppressed gastric cancer cell migration. These results suggest that Wnt-5a stimulates cell migration by regulating focal adhesion complexes and that Wnt-5a is not only a prognostic factor but also a good therapeutic target for gastric cancer. (Cancer Res 2006; 66(21): 10439-48)
Low Dietary Folate Initiates Intestinal Tumors in Mice, with Altered Expression of G2-M Checkpoint Regulators Polo-Like Kinase 1 and Cell Division Cycle 25c
Authors: Knock Erin , Deng Liyuan , Wu Qing , Leclerc Daniel , Wang Xiao-ling , Rozen Rima
Published: November 2006

Clinical reports have suggested that low dietary folate increases risk for colorectal cancer. Animal studies for investigation of folate and tumorigenesis have used carcinogen induction or mice with germ-line mutations. We have developed a new spontaneous tumor model in which mice, with or without a null allele in a key folate-metabolizing enzyme, methylenetetrahydrofolate reductase (Mthfr), develop intestinal tumors due to low dietary folate alone. On folate-deficient diets, 12.5% of Mthfr+/+ mice and 28.1% of Mthfr+/− mice developed tumors; mice on control diets were negative. Dietary and genotype effects on tumor development were significant. To investigate mechanisms of folate-dependent tumorigenesis, we examined levels of DNA damage and gene expression of two genes involved in DNA damage response and G2-M checkpoint regulation, polo-like kinase 1 (Plk1) and cell division cycle 25c (Cdc25c). Folate deficiency increased DNA damage and decreased expression of both genes (assessed by quantitative reverse transcription-PCR and immunofluorescence) in normal intestine compared with levels in mice on control diets. An immunofluorescence assay for CDC25c activity (phosphorylated CDC2) also found CDC25c activity to be decreased in folate-deficient normal intestine. In tumors, however, Plk1 and Cdc25c mRNA were found to be higher (11- and 3-fold, respectively) compared with normal intestine from folate-deficient mice; immunofluorescence studies of PLK1, CDC25c, and phosphorylated CDC2 supported these findings. Our data suggest that folate deficiency can initiate tumor development, that Mthfr mutation can enhance this phenomenon, and that altered expression of Plk1 and Cdc25c may contribute to folate-dependent intestinal tumorigenesis. (Cancer Res 2006; 66(21): 10349-56)
Mapping a Sex Hormone–Sensitive Gene Determining Female Resistance to Liver Carcinogenesis in a Congenic F344.BN-Hcs4 Rat
Authors: De Miglio Maria R. , Virdis Patrizia , Calvisi Diego F. , Frau Maddalena , Muroni Maria R. , Simile Maria M. , Daino Lucia , Careddu Giovanni M. , Sanna-Passino Eraldo , Pascale Rosa M. , Feo Francesco
Published: November 2006

Hepatocellular carcinoma (HCC) is prevalent in human and rodent males. Hepatocarcinogenesis is controlled by various genes in susceptible F344 and resistant Brown Norway (BN) rats. B alleles at Hcs4 locus, on RNO16, control neoplastic nodule volume. We constructed the F344.BN-Hcs4 recombinant congenic strain (RCS) by introgressing a 4.41-cM portion of Hcs4 from BN strain in an isogenic F344 background. Preneoplastic and neoplastic lesions were induced by the “resistant hepatocyte” protocol. Eight weeks after initiation, lesion volume and positivity for proliferating cell nuclear antigen (PCNA) were much higher in lesions of F344 than BN rats of both sexes. These variables were lower in females than in males. Lesion volume and PCNA values of male RCS were similar to those of F344 rats, but in females corresponded to those of BN females. Carcinomatous nodules and HCC developed at 32 and 60 weeks, respectively, in male F344 and congenics and, rarely, in F344 females. BN and congenic females developed only eosinophilic/clear cells nodules. Gonadectomy of congenic males, followed by β-estradiol administration, caused a decrease in Ar expression, an increase in Er-α expression, and development of preneoplastic lesions comparable to those from BN females. Administration of testosterone to gonadectomized females led to Ar increase and development of preneoplastic lesions as in F344 males. This indicates a role of homozygous B alleles at Hcs4 in the determination of phenotypic patterns of female RCS and presence at Hcs4 locus of a high penetrance gene(s), activated by estrogens and inhibited/unaffected by testosterone, conferring resistance to females in which the B alleles provide higher resistance. (Cancer Res 2006; 66(21): 10384-90)
Increased Susceptibility to Diet-Induced Obesity in Histamine-Deficient Mice
Authors: Jørgensen Emilie A. , Vogelsang Thomas W. , Knigge Ulrich , Watanabe Takeshi , Warberg Jørgen , Kjaer Andreas
Published: November 2006

Background and Aim: The neurotransmitter histamine is involved in the regulation of appetite and in the development of age-related obesity in mice. Furthermore, histamine is a mediator of the anorexigenic action of leptin. The aim of the present study was to investigate a possible role of histamine in the development of high-fat diet (HFD)-induced obesity. Methods: Histamine-deficient histidine decarboxylase knock-out (HDC-KO) mice and C57BL/6J wild-type (WT) mice were given either a standard diet (STD) or HFD for 8 weeks. Body weight, 24-hour caloric intake, epididymal adipose tissue size, plasma leptin concentration and quantitative expression of leptin receptor (Ob-R) mRNA were measured. Results: Both HDC-KO and WT mice fed an HFD for 8 weeks increased their body weight significantly more than STD-fed mice. A significant difference in body weight gain between HDC-KO mice fed an HFD or an STD was seen after 2 weeks, whereas a significant difference in body weight gain was first observed after 5 weeks in WT mice. After 8 weeks 24-hour caloric intake was significantly lower in HFD- than in STD-fed WT mice. In HDC-KO mice no difference in caloric intake was observed between HFD- and STD-fed mice. After 8 weeks epididymal adipose tissue size and plasma leptin concentration had increased significantly in HFD-fed WT and HDC-KO mice compared to their STD-fed controls. Epididymal adipose tissue size was higher in HDC-KO than WT mice, both in STD- and HFD-fed mice. A significant decrease in Ob-R mRNA in HFD-fed HDC-KO mice compared to STD-fed HDC-KO mice was observed, while no such difference was observed in WT mice. Conclusion: Based on our results, we conclude that histamine plays a role in the development of HFD-induced obesity.
Isolation and Characterization of Rat Pituitary Endothelial Cells
Authors: Chaturvedi Kirti , Sarkar Dipak K.
Published: November 2006

Most previous studies that determined the effect of estradiol on angiogenesis used endothelial cells from nonpituitary sources. Because pituitary tumor tissue receives its blood supply via portal and arterial circulation, it is important to use pituitary-derived endothelial cells in studying pituitary angiogenesis. We have developed a magnetic separation technique to isolate endothelial cells from pituitary tissues and have characterized these cells in primary cultures. Endothelial cells of the pituitary showed the existence of endothelial cell marker, CD31, and of von Willebrand factor protein. These cells in cultures also showed immunoreactivity of estrogen receptors alpha and beta. The angiogenic factors, vascular endothelial growth factor and basic fibroblast growth factor, significantly increased proliferation and migration of the pituitary-derived endothelial cells in primary cultures. These results suggest that a magnetic separation technique can be used for enrichment of pituitary-derived endothelial cells for determination of cellular mechanisms governing the vascularization in the pituitary.
Progestin Concentrations Are Increased following Paced Mating in Midbrain, Hippocampus, Diencephalon, and Cortex of Rats in Behavioral Estrus, but Only in Midbrain of Diestrous Rats
Authors: Frye Cheryl A. , Rhodes Madeline E.
Published: November 2006

Background: The progesterone (P4) metabolite, 5α-pregnan-3α-ol-20-one (3α,5α-THP), acts in the midbrain ventral tegmental area (VTA) to modulate the intensity and duration of lordosis. 3α,5α-THP can also have anti-anxiety and anti-stress effects in part through actions in the hippocampus. Separate reports indicate that manipulating 3α,5α-THP levels in the VTA or hippocampus respectively can influence lordosis and affective behavior. 3α,5α-THP levels can also be altered by behavioral experiences, such as mating or swim stress. Whether endogenous levels of 3α,5α-THP modulate and/or are increased in response to affective and/or reproductively-relevant behaviors was investigated. Methods: In Experiment 1, rats in behavioral estrus or diestrus were individually tested sequentially in the open field, elevated plus maze, partner preference, social interaction, and paced mating tasks and levels of 17β-estradiol (E2), P4, dihydroprogesterone (DHP), and 3α,5α-THP in serum, midbrain, hippocampus, diencephalon, and cortex were examined. In Experiments 2 and 3, rats in behavioral estrus or diestrus, were individually tested in the battery indicated above, with, or without, paced mating and tissues were collected immediately after testing for later assessment of endocrine measures. Results: In Experiment 1, behavioral estrous, compared to diestrous, rats demonstrated more exploratory, anti-anxiety, social, and reproductive behaviors, and had higher levels of E2 and progestins in serum, midbrain, hippocampus, diencephalon, and cortex. In Experiment 2, in midbrain and hippocampus, levels of 3α,5α-THP and its precursor DHP were increased among rats in behavioral estrus that were mated. In diencephalon, and cortex, DHP levels were increased by mating. In Experiment 3, in midbrain, levels of 3α,5α-THP and its precursor DHP were increased among diestrous rats that were tested in the behavioral battery with mating as compared to those tested in the behavioral battery without mating. Conclusions: Increased levels of 3α,5α-THP in behavioral estrus versus diestrous rats are associated with enhanced exploratory, anti-anxiety, social, and reproductive behaviors. Rats in behavioral estrus that are mated have further increases in 3α,5α-THP and/or DHP levels in midbrain, hippocampus, diencephalon, and cortex than do non-mated rats in behavioral estrus, whereas diestrous rats only show 3α,5α-THP increases in midbrain in response to behavioral testing that included mating.
Glucocorticoid Regulation of GLT-1 Glutamate Transporter Isoform Expression in the Rat Hippocampus
Authors: Autry Anita E. , Grillo Claudia A. , Piroli Gerardo G. , Rothstein Jeffrey D. , McEwen Bruce S. , Reagan Lawrence P.
Published: November 2006

Background: In the rat hippocampus, the predominate glutamate transporters are GLT-1 and its recently identified isoform, GLT-1b. Chronic restraint stress increases GLT-1b expression throughout the hippocampus while more selectively increasing GLT-1 expression in the CA3 region. These studies suggest that GLT-1b expression is regulated by stress levels of glucocorticoids (GCs) and GLT-1 expression is regulated by stress-induced increases in extracellular glutamate levels in the CA3 region. Methods: In order to differentiate between the actions of GCs and glutamate, we examined GLT-1 isoform expression in adrenalectomized (ADX) rats and rats exposed to stress levels of GCs. Results: ADX rats revealed no significant differences in GLT-1b mRNA or protein levels compared to sham-operated controls or ADX rats given GC replacement. However, rats exposed to stress levels of GCs exhibited increases in GLT-1b protein expression in the CA3 region and the dentate gyrus. GLT-1 mRNA expression was increased by ADX, increases that were inhibited by GC replacement. Similarly, stress levels of GCs increased GLT-1 protein expression throughout the hippocampus. Conclusions: Taken together, these data indicate that GLT-1b protein expression is regulated by stress levels of GCs while the regulation of GLT-1 mRNA and protein expression provides another example of the biphasic actions of GCs in the central nervous system.
An Integrative Approach to Teaching the Undergraduate Geography Course Aboriginal Peoples of the United States and Canada
Authors: Gordon Jeffrey J.
Published: November 2006

Many Canadian and American academics teach about Aboriginal peoples within their own countries. However, students are left with an inaccurate and incomplete understanding if they learn only about Aboriginal peoples in the United States without including overlapping cultures in Canada and vice versa. Differences and similarities between Canadian and U.S. relationships with Aboriginal peoples need delineation. The retirement of a faculty member who taught Geography 337: American Indian led to a major course restructuring. Issues of geography, terminology, semantics, perceptions, politics, and pedagogy all factored into a shift to incorporate Canadian content. The resulting course transformation included a name change to Aboriginal Peoples of the United States and Canada, a revised course description, and corresponding revisions to course content and approach. These necessary modifications were instituted to reflect a more accurate northern North American reality.
Social work education’s cultural hegemony
Authors: Askeland Gurid Aga , Payne Malcolm
Published: November 2006

English

Globalization presses social work education towards post-colonial oppression of local cultures by dominant cultures, deepening economic difference and dependency. Diverse, local cultures and languages may be lost in internationalized social work education. Social work educational structures must combat cultural hegemony, allowing cultural translation of materials from dominant cultures and languages.

French

En matière d'enseignement du travail social, la mondialisation accentue l'oppression post-coloniale des cultures locales par les cultures dominantes, accroissant ainsi les différences économiques et la dépendance. L'internationalisation de l'enseignement du service social risque d'effacer les langues et la diversité des cultures locales. Les structures d'enseignement du travail social doivent combattre l'hégémonie culturelle en assurant que les contenus véhiculés entre les cultures dominantes et les cultures locales soient adaptés.

Spanish

La globalización empuja a la educación del trabajo social hacia una opresión post-colonial de culturas locales, opresión ejercida por las culturas dominantes, de modo que las diferencias económicas y situación de dependencia se ahonda aun más. Es posible que en la educación internacionalizada del trabajo social se pierdan las diversas culturas locales y las lenguas. Las estructuras educativas del trabajo social deben combatir la hegemonía cultural, permitiendo la traducción cultural de los materiales provenientes de culturas y lenguas dominantes.
Using Foucault’s concept of power to analyze school discipline and draw implications for school social work service in Hong Kong
Authors: To Siu-ming
Published: November 2006

English

This article incorporates Foucault's conception of power to study how power relations exist in school discipline and contribute to the constitution of Hong Kong students' and teachers' subjectivities. It is argued that such an analysis of a significant aspect of the school social work profession can help practitioners enhance their reflexivity and promote empowering practices.

French

Cette étude s'appuie sur la conception du pouvoir de Foucault pour analyser les relations de pouvoir existant dans la discipline scolaire et leur impact sur la subjectivité des professeurs et des étudiants de Hong Kong. Cette thèse soutient qu'une telle analyse du travail social scolaire peut aider les praticiens à ameliorer leur réflexivité et à promouvoir des pratiques responsabilisantes.

Spanish

Este artículo incorpora la concepción de poder de Foucault para estudiar cómo las relaciones de poder están presentes en la disciplina escolar y contribuyen a la constitución de las subjetividades de estudiantes y maestros en Hong Kong. Se argumenta que un análisis de este tipo puede ayudar a los practicantes de la profesión del trabajo social a aumentar su reflexividad y promover el fortalecimiento de las prácticas.
Ethics in Nanotechnology: Starting From Scratch?
Authors: Ebbesen Mette , Andersen Svend , Besenbacher Flemming
Published: November 2006

Research in nanotechnology has advanced rapidly in recent years. Several researchers, however, warn that there is a paucity of research on the ethical, legal, and social implications of nanotechnology, and they caution that ethical reflections on nanotechnology lag behind this fast developing science. In this article, the authors question this conclusion, pointing out that the predicted concrete ethical issues related to the area of nanotechnology are rather similar to those related to the area of biotechnology and biology that have been considered by ethicists since the 1970s. Hence, a knowledge base has already been acquired from ethical reflections on biotechnology and biology, which may be a good starting point and foundation for a discussion of ethical reflections on nanotechnology. The authors argue that a promising approach is the use of basic ethical principles as a method to analyze ethical issues of nanotechnology.
Characterization of Stress Distribution and Thermal Expansion Behavior for M40J/AG-80 Composites Experienced Vacuum Thermo-cycling
Authors: Yu Gao , Shang-Li Dong , Song He , De-Zhuang Yang , Zhi-Jun Li
Published: November 2006

The characterization of stress distribution and thermal expansion/contraction distortion is performed for a unidirectional M40J/AG-80 epoxy composite, which experienced vacuum thermo-cycling in a temperature interval of −180 to 140°C under 10-5 Pa. The finite element analysis, using MSC.Marc 2001 software shows that vacuum thermo-cycling leads to stress concentration appearing at the interface layer, providing a stress condition to form debonding. The transverse expansion/contraction distortion changes linearly with temperature for both samples before and after thermo-cycling, while the longitudinal contraction shows a nonlinear behavior after the thermo-cycling. The variation in longitudinal contraction distortion can be attributed to the interface debonding.
Acute amitraz intoxication: retrospective analysis of 45 cases
Authors: Demirel Y , Yilmaz A , Gursoy S , Kaygusuz K , Mimaroglu C
Published: November 2006

Objective: To present special clinical and laboratory features of 45 cases (44 adult cases) who were intoxicated through oral route. Design: Retrospective study. Setting: Intensive care unit (ICU) of a university hospital. Patients: Forty-five patients admitted to the ICU of Cumhuriyet University Hospital. Results: Forty-five patients between 4 and 97 years of age were evaluated. Intoxication was the result of a suicide attempt in 67% of cases and accidental in 33% of cases. Unconsciousness, nausea and vomiting were the common initial symptoms. The major clinical findings in the ICU were bradycardia, myosis, hypothermia, hyperglycemia, hypotension, coma and respiratory depression. Blood glucose level was increased in 64% of cases. No problem was noted in the patient or the fetus in a pregnant, 27-year-old patient, who was intoxicated with 10 mL of 12.5% amitraz. The length of stay in the ICU was between 2 and 15 days. None of the patients died. All patients were discharged without neurological sequela. Conclusion: The prognosis of amitraz intoxications through oral route is benign and results in complete healing; however, we suggest that these cases should be well monitored and followed-up in ICUs.
Study of a functional polymorphism in thep53 gene in systemic lupus erythematosus: lack of replication in a Spanish population
Authors: Sánchez E , Sabio J M , Callejas J L , de Ramón E , de Haro M , Jiménez-Alonso J , Ortego-Centeno N , Sánchez-Román J , González-Gay M A , López-Nevot M A , González-Escribano M F , Martín J
Published: November 2006

The aim of this study was to assess the possible association between the p53 suppressor gene codon 72 polymorphism and systemic lupus erythematosus (SLE). Our study population consisted of 513 SLE patients and 567 healthy controls. All the individuals were of Spanish Caucasian origin. Genotyping of the p53 codon 72 polymorphism was performed by allele-specific PCR. No statistically significant differences were observed between SLE patients and healthy controls when p53 codon 72 genotype and allele frequencies were compared. In addition, no evidence for association with clinical subfeatures of SLE was found. In conclusion, the p53 codon 72 polymorphism associated with SLE in a Korean population does not appear to play a major role in the susceptibility or severity of SLE in the Spanish population.
Fostering International Student Exchanges for Science Students
Authors: Guest David , Livett Michelle , Stone Nick
Published: November 2006

This article outlines an ongoing initiative that was also part of the “Navigating Other Cultures” project at the University of Melbourne. It seeks to address the underrepresentation of science students from this university in international exchange programs. It includes a brief literature review that highlights the intrinsically international nature of science, the need for more internationally competent graduates, and benefits of international experiences for students. Two surveys were designed and administered. The first was intended to gain essential information about the reasons that so few science students choose to undertake international exchange programs. The second asked science faculty staff to provide information about the nature and perceived value of their own international experiences. The findings of both surveys are used to propose future strategies to foster greater participation in international exchanges by science students.
Internationalising the Student Learning Experience: Possible Indicators
Authors: Stone Nick
Published: November 2006

The following lists offer indicators with which a tertiary institution may choose to audit, review, and develop opportunities to internationalise student learning experiences. They are classified under the headings: Staff and Student Attributes, International Relations, Curriculum Design and Content, and Curriculum Delivery. Although they do not constitute an exhaustive inventory of possibilities to internationalise, they have proven useful in a range of academic professional activities at this university and hopefully will do so elsewhere.
Globalisation and International Higher Education: Contested Positionings
Authors: Dixon Mary
Published: November 2006

This article stems from recent policy research involving participants in an international higher education program. Story lines of the program from Thai and Australian policy makers and policy actors are interpreted from a poststructural stance. Through the multiple and shifting positionings of the participants, agency and identity within this globalised space is constructed and reconstructed. The study contributes constructions of the relationship between globalisation and international higher education previously obscured by the apparent domination of the neoliberal discourse. Possibilities for international higher education as constructive of globalisation are encountered in these policy readings.
The Creation of Trust Through Interaction and Exchange
Authors: Nugent Paul D. , Abolafia Mitchel Y.
Published: November 2006

Scholars generally agree that highly effective organizations require the cultivation of personal relationships that are high in trust. However, although most conceptualizations of relational trust stress the roles of intention and choice, few explain how these are socially constructed in discrete interactions. To this end, the authors introduce the concept of consideration. Consideration entails a mode of interaction in which (a) a resource is bestowed to a recipient, (b) under a context of choice, (c) involving little sacrifice on the part of the giver, and (d) implying that the recipient’s situation is present in the giver’s thoughts and feelings. Consideration was observed to be central to trust formation and maintenance in a large defense company. Collegial relationships high in trust are characterized by the consistent application of consideration where there are perceived opportunities. These findings have useful implications for management, network theory, social capital, economic sociology, and friendship in the workplace.