Magnetite nanoparticles as a kinetically favorable source of iron to enhance GBM response to chemoradiosensitization with pharmacological ascorbate

Ferumoxytol (FMX) is an FDA-approved magnetite (Fe3O4) nanoparticle used to treat iron deficiency anemia that can also be used as an MR imaging agent in patients that can't receive gadolinium. Pharmacological ascorbate (P-AscH-; IV delivery; plasma levels ≈ 20 mM) has shown promise as an adjuvant to standard of care chemo-radiotherapy in glioblastoma (GBM). Since ascorbate toxicity mediated by H2O2 is enhanced by Fe redox cycling, the current study determined if ascorbate catalyzed the release of ferrous iron (Fe2+) from FMX for enhancing GBM responses to chemo-radiotherapy. Ascorbate interacted with Fe3O4 in FMX to produce redox-active Fe2+ while simultaneously generating increased H2O2 fluxes, that selectively enhanced GBM cell killing (relative to normal human astrocytes) as opposed to a more catalytically active Fe complex (EDTA-Fe3+) in an H2O2 - dependent manner. In vivo, FMX was able to improve GBM xenograft tumor control when combined with pharmacological ascorbate and chemoradiation in U251 tumors that were unresponsive to pharmacological ascorbate therapy. These data support the hypothesis that FMX combined with P-AscH- represents a novel combined modality therapeutic approach to enhance cancer cell selective chemoradiosentization in the management of glioblastoma.

Blebbistatin-Loaded Poly(d,l-lactide-co-glycolide) Particles For Treating Arthrofibrosis

Joint immobility is a debilitating complication of articular trauma that is characterized by thickening and stiffening of the joint capsule and the formation of fibrotic lesions inside joints. Capsule release surgery can temporarily restore mobility, but contraction often recurs due to the contractile activities of fibroblasts, which exert tension on the capsule ECM via nonmuscle myosin II. Based on these findings we hypothesized that blebbistatin, a drug that reversibly inhibits the activity of this protein, would relax ECM tension imposed by fibroblasts and reduce fibrosis. In this study, we characterized the effectiveness of blebbistatin as an anticontractile treatment. Given that sustained suppression of contractile activity may be required to achieve capsule release and reduce fibrosis, we compared the effects on fibroblast-mediated collagen ECM displacement of blebbistatin-loaded poly(lactide-co-gylcolide) (PLGA) particles versus bolus blebbistatin dosing. Time-lapse imaging of fluorescent microspheres embedded in collagen gels confirmed that PLGA/blebbistatin inhibited force generation and reduced both gel displacement and rate of displacement. In addition, collagen production at 10 days was significantly reduced. Taken together, these data indicate that blebbistatin-loaded PLGA particles can be used to inhibit fibroblast force-generation and reduce collagen production and lay the foundation for optimization of drug delivery technology for treating arthrofibrosis.

Hepatocellular carcinoma in Yemeni patients: a single centre experience over an 8-year period

We carried out a retrospective study of all patients admitted to Al-Thawra Teaching Hospital in Sana'a with hepatocellular carcinoma to study the disease profile in Yemeni patients and identify possible risk factors. During the 8-year study period, January 2001-December 2008, 251 patients were admitted with confirmed hepatocellular carcinoma. From hospital records we collected data on demographic characteristics, clinical manifestations, histological characters, viral markers, treatment and outcome. Around 75% of the patients were males. Age range was 26-75 years, mean 53.5 (SD 13.9) years. Most patients were farmers (73.7%) and had a history of chemical contact. Chronic hepatitis B virus infection (48.2%) and hepatitis C virus infection (38.2%) were the most frequently identified risk factors. Qat chewing and smoking were not statistically significant risk factors. Right lobe involvement was seen in 109 (43.4%) patients and 154 (61.4%) presented with multiple lesions. We found 187 (74.0%) patients had cirrhotic liver associated with hepatocellular carcinoma. Overall mortality rate within 6 months of admission to hospital was 24.3%.

Tumor immunotherapy using adenovirus vaccines in combination with intratumoral doses of CpG ODN

The combination of viral vaccination with intratumoral (IT) administration of CpG ODNs is yet to be investigated as an immunotherapeutic treatment for solid tumors. Here, we show that such a treatment regime can benefit survival of tumor-challenged mice. C57BL/6 mice bearing ovalbumin (OVA)-expressing EG.7 thymoma tumors were therapeutically vaccinated with adenovirus type 5 encoding OVA (Ad5-OVA), and the tumors subsequently injected with the immunostimulatory TLR9 agonist, CpG-B ODN 1826 (CpG), 4, 7, 10, and 13 days later. This therapeutic combination resulted in enhanced mean survival times that were more than 3.5× longer than naïve mice, and greater than 40% of mice were cured and capable of resisting subsequent tumor challenge. This suggests that an adaptive immune response was generated. Both Ad5-OVA and Ad5-OVA + CpG IT treatments led to significantly increased levels of H-2 K(b)-OVA-specific CD8+ lymphocytes in the peripheral blood and intratumorally. Lymphocyte depletion studies performed in vivo implicated both NK cells and CD8+ lymphocytes as co-contributors to the therapeutic effect. Analysis of tumor infiltrating lymphocytes (TILs) on day 12 post-tumor challenge revealed that mice treated with Ad5-OVA + CpG IT possessed a significantly reduced percentage of regulatory T lymphocytes (Tregs) within the CD4+ lymphocyte population, compared with TILs isolated from mice treated with Ad5-OVA only. In addition, the proportion of CD8+ TILs that were OVA-specific was reproducibly higher in the mice treated with Ad5-OVA + CpG IT compared with other treatment groups. These findings highlight the therapeutic potential of combining intratumoral CpG and vaccination with virus encoding tumor antigen.

Prevalence of HCV among Yemeni patients with non-Hodgkin's lymphoma at AI-Thawra teaching hospital

BACKGROUND

Epidemiological studies in different parts of the world have revealed controversial results on the association between HCV infection and Non-Hodgkin's lymphomas. This discrepancy suggests that HCV lymphotropism and its effect on host lymphocytes may be influenced by regional and racial factors as well as by viral genomic variations.

OBJECTIVES

To determine the prevalence of HCV infection in Yemeni patients with NHLs diagnosed and treated in our hospital and to evaluate the association between the two diseases.

METHODS

All consecutive patients with NHL treated in our Haematology/Oncology Unit between January 2005 and January 2007 were screened for anti- HCV antibodies by enzyme immunoassay. The prevalence of HCV infection in patients with NHLs was compared to that in a non-lymphomatous control group consisted of all patients checked for HCV infection with several acute medical conditions in the same hospital who were coming from different parts of the country.

RESULTS

A total of 192 patients with NHLs were tested for anti-HCV antibodies. One hundred seventeen patients (60.94%) were males and 75 patients (39.06%) were females. The mean age of the patients was 41.30+/-19.15 SD and range between 5-80 years. Twenty-nine (15.1%) of the 192 patients were found positive for HCV infection. Twenty-one (17.6%) of 29 positive patients were male and only 8 (10.7%) patients were female. The mostly involved age group was 41-60 representing 24.6%. A total of 20329 patients from different departments were investigated for anti-HCV antibodies and used as a control. Of the 12274 control (60.4%) were males and 8055 (39.6%) were females. A total of 814 (4%) controls were found positive for HCV antibodies. Of the positive controls, 529 (4.3%) were males and 285 (3.5%) were females. The association between HCV infection and NHLs was assessed using logistic regression models. There was a significant association of HCV with NHLs, the unadjusted OR [4.27, 95% CI 2.86-6.37] which differ slightly by gender in males the OR [4.86, 95% CI 3.01 - 7.85] and in female the OR [3.26, 95%CI 1.55- 6.84]. For separate NHL subtypes, the numbers of HCV infected cases were limited. Nonetheless, positive associations were noted for indolent type [OR=4.49, 95% CI 1.87-10.78] and for aggressive type as well [OR=4.2195% CI 2.69-6.59]. The prevalence of HCV antibodies in cases and controls was more frequent in males and in the age group above 40 years.

CONCLUSION

In conclusion the results of the present study indicate a higher prevalence of HCV infection among Yemeni patients with NHL than among persons in the control group. Therefore our study demonstrates an association between HCV infection and NHLs. HCV infection may play a role in causing NHLs.

Synthesis and characterisation of a degradable poly(lactic acid)-poly(ethylene glycol) copolymer with biotinylated end groups

Poly(lactic acid)-poly(ethylene glycol)-biotin (PLA-PEG-biotin) is a degradable polymer with protein resistant properties that can undergo rapid surface engineering in aqueous media to create biomimetic surfaces. Surface engineering of this polymer is dependent on biomolecular interactions between the biotin end group and the protein avidin. Given the vigorous conditions of synthesis, it is essential that the manufacture of the polymer does not alter the biotin structure or its molecular recognition. Equally, it is important that the incorporation of biotin does not adversely affect the physicochemical properties of the polymer. (1)H NMR provides evidence of biotin attachment and structural integrity. (1)H NMR, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC) analysis shows there is no significant effect on bulk properties induced by the biotin end group. Surface plasmon resonance (SPR) and fluorescent spectroscopy studies using the 2-(4'-hydroxyazobenzene) benzoic acid (HABA)/avidin complex show that the biotin moieties binding capabilities are not impaired by the synthesis.

Interactions of 3T3 fibroblasts and endothelial cells with defined pore features

The colonization of biodegradable polymer scaffolds with cell populations has been established as the foundation for the engineering of a number of tissues, including cartilage, liver, and bone. Within these scaffolds, the cells encounter a porous environment in which they must migrate across the convoluted polymer surface to generate a homogenous cell distribution. Predicting the interactions between cells and pores is important if scaffold characteristics are to be optimized. Therefore, we investigated the behavior of two model cell types over a range of defined pore features. These pore features range from 5 to 90 microm in diameter and have been fabricated by photolithographic techniques. Quantitatively, the behavior of the cells is dependent on three factors: 1) percentage cell coverage of the surface; 2) pore size; and 3) cell type. Fibroblast cells displayed a co-operative pattern of cell spreading in which pores with diameters greater than the cell dimensions were bridged by groups of cells using their neighbors as supports. Endothelial cells were unable to use neighbors as support structures and failed to bridge pores greater than the cell diameter.