In vitro 3-dimensional tumor model for radiosensitivity of HPV positive OSCC cell lines

The incidence of oropharyngeal squamous cell carcinoma (OSCC) is increasing due to the rising prevalence of human papillomavirus (HPV) positive OSCC. HPV positive OSCC is associated with better outcomes than HPV negative OSCC. Our aim was to explore the possibility that this favorable prognosis is due to the enhanced radiosensitivity of HPV positive OSCC. HPV positive OSCC cell lines were generated from the primary OSCCs of 2 patients, and corresponding HPV positive cell lines generated from nodal metastases following xenografting in nude mice. Monolayer and 3 dimensional (3D) culture techniques were used to compare the radiosensitivity of HPV positive lines with that of 2 HPV negative OSCC lines. Clonogenic and protein assays were used to measure survival post radiation. Radiation induced cell cycle changes were studied using flow cytometry. In both monolayer and 3D culture, HPV positive cells exhibited a heterogeneous appearance whereas HPV negative cells tended to be homogeneous. After irradiation, HPV positive cells had a lower survival in clonogenic assays and lower total protein levels in 3D cultures than HPV negative cells. Irradiated HPV positive cells showed a high proportion of cells in G1/S phase, increased apoptosis, an increased proliferation rate, and an inability to form 3D tumor clumps. In conclusion, HPV positive OSCC cells are more radiosensitive than HPV negative OSCC cells in vitro, supporting a more radiosensitive nature of HPV positive OSCC.     

Human Antibody Fragments Specific for the Epidermal Growth Factor Receptor Selected from Large Non-immunised Phage Display Libraries

Antibodies to EGFR have been shown to display anti-tumour effects mediated in part by inhibition of cellular proliferation and angiogenesis, and by enhancement of apoptosis. Humanised antibodies are preferred for clinical use to reduce complications with HAMA and HAHA responses frequently seen with murine and chimaeric antibodies. We have used depletion and subtractive selection strategies on cells expressing the EGFR to sample two large antibody fragment phage display libraries for the presence of human antibodies which are specific for the EGFR. Four Fab fragments and six scFv fragments were identified, with affinities of up to 2.2 nM as determined by BIAcore analysis using global fitting of the binding curves to obtain the individual rate constants (k_a and k_d). This overall approach offers a generic screening method for the identification of growth factor specific antibodies and antibody fragments from large expression libraries and has potential for the rapid development of new therapeutic and diagnostic reagents.     

Low-Dose Daily Subcutaneous Interleukin-2 in Combination with Highly Active Antiretroviral Therapy in HIV + Patients: A Randomized Controlled Trial

Abstract

Purpose: Previous studies with intermittent interleukin-2 (IL-2) therapy using intermediate and high levels of IL-2 have demonstrated significant increases in the CD4 + T cell count in HIV-infected patients. Intermittent regimens are amenable to outpatient use, but severe adverse events are frequently experienced with intermediate- and high-dose levels of IL-2. Therefore in this study, the effect of daily, subcutaneous low-dose IL-2 therapy on safety and immunological endpoints was investigated to determine whether immunological benefit could be achieved without toxicity in HIV-infected patients also receiving highly active antiretroviral therapy (HAART). Method: A total of 115 patients were enrolled in the trial. Fifty-six asymptomatic HIV-infected patients who had CD4 + T cell counts less than 300 cells/μL at screening and a stable HIV viral load received low-dose IL-2 (1.2 million IU [MIU]/m 2 beginning dose) once daily in conjunction with HAART (IL-2 group). Fifty-nine patients received HAART alone (control group). Results: A dramatic effect of IL-2 on the natural killer (NK) cell population was observed with mean increases of 156 cells/μL in the IL-2 group compared to 19.93 cells/μL in the control group (p < .001). Additionally, IL-2-treated patients experienced a statistically significant increase in the mean percentage of CD4 + T cells (3.52% increase) when compared to control patients (1.33% increase) (p < .001). The expanded CD4 + T cell population was primarily of the naive phenotype, with mean increases of 4.53% for the IL-2 group and 0.31% for the control group (p < .001 for between-group difference). In addition, a higher proportion of IL-2-treated patients (67%) compared to control patients (33%) achieved increases of greater than 50% in the CD4+ T cell count (p = .08). Adverse events of grade 3 or grade 4 toxicity were infrequent in the current study and were substantially lower by comparison to those in studies of intermittent dose IL-2 therapy. Also, negligible changes in the HIV viral load from baseline to final measurement were observed in both groups. A trend toward a reduced number of modifications of antiretroviral therapy was apparent in the IL-2 group when compared to control patients. Conclusion: Daily, low-dose subcutaneous IL-2 therapy in conjunction with HAART is safe and well tolerated and is effective in expanding lymphocyte cell types including NK cells and naive T cells in individuals who have <300 CD4+ T cells.     

5-AZA抑制肝癌细胞BEL7402代谢方式转换

目的研究去甲基化药物5-AZA对miR-34a和miR-34c在肝癌细胞中表达的影响及其抑制肝癌细胞糖酵解的分子机制。方法用real-time PCR法检测肝癌细胞系中miR-34a/c的表达以及糖酵解途径关键酶的表达;在肝癌细胞中过表达miR-34a、miR-34c或用5-AZA处理肝癌细胞,用乳酸检测试剂盒、葡萄糖检测试剂盒分析miR-34a/c及5-AZA对肝癌细胞BEL7402糖酵解的影响;设计拯救实验研究5-AZA、miR-34a/c与肝癌细胞糖酵解调控的关系。结果 5-AZA可以诱导BEL7402肝癌细胞内源性miR-34a、miR-34c的表达上调(P0.01);过表达miR-34a/c可以抑制糖酵解关键酶LDH-A的表达(P0.05);LDH-A是miR-34a/c的潜在靶基因;敲低miR-34a/c的表达可以降低5-AZA对肝癌细胞BEL7302糖酵解途径的抑制作用。结论 5-AZA通过诱导miR-34a/c表达上调,发挥抑制肝癌细胞代谢方式转换的功能。     

From political to personal violence: Links between conflict and non-partner physical violence in post-conflict Liberia

ABSTRACT

War and interpersonal violence together account for a large burden on global health. Yet very few studies look at the relationship between these types of aggression. Non-partner physical violence (NPPV) is an often-understudied form of gender-based violence (GBV). This analysis draws on two datasets from one conflict-affected country, Liberia, to evaluate the impact of conflict on NPPV post-conflict. The Armed Conflict Location and Event Dataset (ACLED) measures the intensity of the conflict in Liberia from 1999-2003, while the Demographic and Heath Survey (DHS) data measure women's experiences with violence four years post-conflict. Almost half of women surveyed (45%) indicated that they experienced any kind of NPPV, highlighting the widespread nature of this issue. A multilevel modelling approach was used to account for the nesting of individuals within districts. Women living in districts that experienced conflict events in four or five years were almost three times as likely (aOR 2.93, p?<?.001) to experience past-year NPPV compared to individuals living in no conflict districts. Findings from this study suggest women residing in a conflict event-affected district may be at heightened risk of increased violence even years after peace is declared.     

The Calculation of Radiation Dose from Distributed Sources of Tritium

Summary

Formulae derived by Rossi and Ellis (1950) for the calculation of radiation dose from distributed sources of beta-emitters have been made applicable to the case of tritium by a consideration of the appropriate value for the effective absorption coefficient employed in these expressions. An example is given of their application to the calculation of dose to a cell from tritium incorporated in the nucleus.     

Metabolism of deltamethrin and cis- and trans-permethrin by rat and human liver microsomes,liver cytosol and plasma preparations

1. The metabolism of deltamethrin (DLM), cis-permethrin (CPM) and trans-permethrin (TPM) was studied in liver microsomes, liver cytosol and plasma from male Sprague–Dawley rats aged 15, 21 and 90 days and from adult humans.

2. DLM and CPM were metabolised by rat hepatic microsomal cytochrome P450 (CYP) enzymes and to a lesser extent by microsomal and cytosolic carboxylesterase (CES) enzymes, whereas TPM was metabolised to a greater extent by CES enzymes.

3. In human liver, DLM and TPM were mainly metabolised by CES enzymes, whereas CPM was metabolised by CYP and CES enzymes.

4. The metabolism of pyrethroids by cytosolic CES enzymes contributes to the overall hepatic clearance of these compounds.

5. DLM, CPM and TPM were metabolised by rat, but not human, plasma CES enzymes.

6. This study demonstrates that the ability of male rats to metabolise DLM, CPM and TPM by hepatic CYP and CES enzymes and plasma CES enzymes increases with age. In all instances, apparent intrinsic clearance values were lower in 15 than in 90?day old rats. As pyrethroid-induced neurotoxicity is due to the parent compound, these results suggest that DLM, CPM and TPM may be more neurotoxic to juvenile than to adult rats.