Assessment of New Relation for the Elastic Compliance of a Film-Substrate System

A new closed-form relation for the elastic compliance of a film-substrate system indented by a flat cylindrical punch is presented. The relation is an extension of the work of Gao at al. [1] modified to increase the applicable range of modulus mismatch between the film and substrate. The accuracy of the relation is assessed by comparison to finite element simulations, other approximate numerical solutions, and nanoindentation experiments performed on a fluorinated silicate glass (FSG) film on a silicon substrate. The benefits and limitations of the relation are discussed.

Effect of exercise training intensity on murine T-regulatory cells and vaccination response

To understand the underlying mechanism(s) for the effect of exercise at different intensities on T cell and DNA vaccination responses, we treated mice in a training protocol with regular moderate-intensity exercise (MIE) or prolonged, exhaustive high-intensity exercise (HIE). After 6 weeks of training, splenocytes were isolated to evaluate cytokine expression and T-regulatory (Treg) cell proportion by RT-PCR and FACS, respectively. Another set of mice that completed the same training protocol were used to determine DNA vaccination responses. These mice were immunized three times with HBV DNA vaccine at 2-week intervals and euthanized on day 14 after the last immunization. Serum and splenocytes were isolated to determine humoral and cell-mediated immunity (CMI). Results showed that HIE increased anti-inflammatory cytokine expression and CD4(+) CD25(+) Treg cell proportion. Further, HIE decreased IFN-γ expression, T-lymphocyte proliferation, and antigen-specic cytotoxic response in HBV DNA vaccine-immunized mice. MIE did not change anti-inflammatory cytokine expression or CD4(+) CD25(+) Treg cell proportion but increased pro-inflammatory cytokine expression and augmented antigen-specific CMI. Thus, MIE lower the risk of cancer and infectious illness through enhancing the pro-inflammatory responses. By contrast, HIE might increase the risk of common infections, such as upper respiratory tract infection, due to an up-regulation of CD4(+) CD25(+) Treg cells and anti-inflammatory responses.

Phase II study of fixed-dose-rate infusion of gemcitabine and UFT combination chemotherapy in patients with advanced bile duct cancer: Daegu Gyeoungbuk Oncology Group

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Background: This phase II study evaluated efficacy of fixed dose rate (FDR) infusion of gemcitabine (10mg/m2/min) and UFT combination in chemo-naïve patients with advanced bile duct cancer.

Methods: This was an open-label, single-arm, multicenter, phase II study with a Simon two-stage minimax design. Patients received the FDR gemcitabine 1,000mg/m2 for 3 consecutive weeks and UFT 400 mg/m2 on days 1-21. The cycle was repeated every 28 days. The primary end point was Response Evaluation Criteria in Solid Tumors (RECIST) -defined objective response rate. Secondary end points included clinical benefit response (CBR), safety, progression-free survival (PFS), and overall survival (OS). Clinical characteristics including four single nucleotide polymorphisms in DNA repair genes (RecQ1, RAD54L, XRCC1, ATM) were evaluated whether these influence the overall survival.

Results: Between December 2006 and February 2008, fifty-one patients were enrolled, with a median age of 58 years. The majority of patients (76%) had intra-hepatic disease. Fourteen patients (27%) had a RECIST investigator-assessed, partial response (PR); disease control rate (PR + stable disease) was 55%. CBR was 14% among 37 evaluable patients. Hematologic toxicity was main grade 3 or 4 treatment-related adverse events. Median PFS was 4.0 months (95% CI, 2.9 to 5.1 months). Median OS was 7.0 months (95% CI, 3.5 to 10.5 months). Intrahepatic disease, poor performance, and, XRCC1 R194W C/C type were predictive markers of poor overall survival.

Conclusions: FDR gemcitabine and UFT demonstrated apparent activity in patients with advanced bile duct cancer. However, this activity did not translate to prolong survival. The location of disease, performance status, and, polymorphic variants of DNA repair genes may affect clinical outcome of patients with advanced bile duct cancer.

No significant financial relationships to disclose.

Lessons for New Classes of Inorganic/Organic Composites from the Spicules and Skeleton of the Sea Sponge Euplectella aspergillum

Studies have been carried out on the structures and mechanical characteristics of an unusual family of sea sponges under the classification of Hexactinellida, genus Euplectella. The sponge spicules have been of interest to materials scientists because of their potentially important optical, coupled with mechanical, properties. The structures of the class Hexactinellida are characterized by a concentric ring appearance in the cross-section, which is a composite of hydrated silica, coupled with silicatein as a thin layer at the ring interfaces. The mechanical behavior and the toughness of the spicules have been examined with the aid of a special fiber testing method, coupled with scanning electrom microscopy (SEM) observations. It appears that there may be common mechanisms underlying toughness in rigid natural composites with high ratios of mineral/organic phase. In addition, novel pressurization tests of a portion of the sponge skeleton have provided information about the resilience of the skeleton, which resembles a selfsupporting glass winding of a cylindrical composite structure.

On the Feasibility of Verification of 3D Dosimetry Near Brachytherapy Sources Using PRESAGE/Optical-CT

PURPOSE: The feasibility of using the PRESAGE/Optical-CT system for 3D dosimetry verification around a brachytherapy source is investigated. METHOD AND MATERIALS: Brachytherapy dose distributions were obtained by irradiation of cylindrical PRESAGE volumes 6cm in diameter by 8cm height with a GammaMed 12i Ir-192 HDR unit (Varian Medical Systems). A narrow channel on the central axis was created by setting a steel catheter in the Presage during manufacture, enabling measurements close to the source (~3mm). RESULTS: Comparison of dose line profiles shows good agreement between PRESAGE and verified calculated dose calculation, in both high and low dose regions. CONCLUSION: The PRESAGE/Optical-CT shows good potential in verification of 3D dose distributions around brachytherapy sources.

Model-based aberration correction in a closed-loop wavefront-sensor-less adaptive optics system

In many scientific and medical applications, such as laser systems and microscopes, wavefront-sensor-less (WFSless) adaptive optics (AO) systems are used to improve the laser beam quality or the image resolution by correcting the wavefront aberration in the optical path. The lack of direct wavefront measurement in WFSless AO systems imposes a challenge to achieve efficient aberration correction. This paper presents an aberration correction approach for WFSlss AO systems based on the model of the WFSless AO system and a small number of intensity measurements, where the model is identified from the input-output data of the WFSless AO system by black-box identification. This approach is validated in an experimental setup with 20 static aberrations having Kolmogorov spatial distributions. By correcting N=9 Zernike modes (N is the number of aberration modes), an intensity improvement from 49% of the maximum value to 89% has been achieved in average based on N+5=14 intensity measurements. With the worst initial intensity, an improvement from 17% of the maximum value to 86% has been achieved based on N+4=13 intensity measurements.

Concomitant increases in spectrum and level of drug resistance in Mycobacterium tuberculosis isolates

OBJECTIVE

To determine the drug resistance spectrum and resistance levels of extensively drug-resistant (XDR-) and multidrug-resistant tuberculosis (MDR-TB) and TB resistant to either rifampicin (RMP, R) or isoniazid (INH, H; R/H-DR).

DESIGN

Of 142 drug-resistant clinical isolates examined, 13 were XDR-TB, 66 were MDR-TB and 63 were R/H-DR. The drug resistance spectrum was tested by the absolute two-concentration method. Minimum inhibitory concentrations (MICs) were determined for the strains by agar dilution method on Löwenstein-Jensen slants.

RESULTS

The drug resistance spectrum of XDR-TB, MDR-TB and R/H-DR TB isolates ranged from 4 to 9, 2 to 6 and 1 to 5 drugs, respectively. Over half of all XDR-TB (53.8%), MDR-TB (66.7%) and R/H-DR (54.0%) isolates were resistant to two other anti-tuberculosis drugs; 38.5% of XDR-TB, 24.2% of MDR-TB and 28.6% of R/H-DR TB isolates were resistant to ≥ 3 additional anti-tuberculosis drugs in addition to those originally defined, demonstrating that the MIC values and the proportions of strains with higher MICs followed a trend of XDR-TB > MDR-TB > R/H-DR for INH, RMP, ofloxacin and ethambutol.

CONCLUSION

XDR-TB, MDR-TB and R/H-DR TB isolates exhibited both increasingly broader resistance spectra and a higher percentage of strains with high MICs to more frequently resistant drugs, which might be related to patterns of TB chemotherapy.

Carbon monoxide releasing molecule-3 inhibits concurrent tumor necrosis factor-α- and interleukin-1β-induced expression of adhesion molecules on human gingival fibroblasts

BACKGROUND AND OBJECTIVE

Carbon monoxide releasing molecule-3 (CORM-3) is a newly reported compound that has shown anti-inflammatory effects in a number of cells. In this study, we aimed to investigate the influence of CORM-3 on concurrent tumor necrosis factor-α (TNF-α)- and interleukin (IL)-1β-induced expression of adhesion molecules on human gingival fibroblasts (HGF).

MATERIAL AND METHODS

HGF were cultured from the explants of normal gingival tissues. Cells were costimulated with TNF-α and IL-1β in the presence or absence of CORM-3 for different periods of time. The expression of adhesion molecules, nuclear factor-kappaB (NF-κB) and phosphorylated p38 was studied using western blotting. RT-PCR was applied to check the expression of the adhesion molecules at the mRNA level. The activity of NF-κB was analysed using a reporter gene assay.

RESULTS

CORM-3 inhibited the up-regulation of intercellular adhesion molecule 1, vascular cell adhesion molecule 1 and endothelial leukocyte adhesion molecule in HGF after costimulation with TNF-α and IL-1β, which resulted in the decreased adhesion of peripheral blood mononuclear cells to these cells. Sustained activation of the NF-κB pathway by costimulation with TNF-α and IL-1β was suppressed by CORM-3, which was reflected by a reduced NF-κB response element-dependent luciferase activity and decreased nuclear NF-κB-p65 expression. CORM-3 inhibited MAPK p38 phosphorylation in response to stimulation with proinflammatory cytokines.

CONCLUSION

The results of this study bode well for the application of CORM-3 as an anti-inflammatory agent to inhibit NF-κB activity and to suppress the expression of adhesion molecules on HGF, which suggests a promising potential for CORM-3 in the treatment of inflammatory periodontal disease.

Optimal pulmonary artery perfusion mode and perfusion pressure during cardiopulmonary bypass

AIM

Reducing lung injury during cardiopulmonary bypass (CPB) is important for patients' recovery. The present study was designed to evaluate the effects of pulmonary artery perfusion pressure on the extent of lung injury during CPB in an animal model.

METHODS

Twenty healthy mongrel dogs were randomly divided into four groups, including a control group and three perfusion groups designed to simulate clinical cardiopulmonary bypass-induced lung injury. During pulmonary ischemia and cardiopulmonary bypass, protective perfusions were performed using different perfusion pressures (15-20, 25-30, and 40-45 mmHg), while animals in the control group were not perfused. After pulmonary reperfusion, the changes in pulmonary function and tissue histopathology were determined.

RESULTS

Compared with the control group, lung compliance, oxygenation and vascular resistance after reperfusion were significantly improved in both low- and moderate-pressure groups. The malonaldehyde concentration, neutrophil sequestration ratio, and expression of ICAM-1 were also decreased significantly in the two groups. However, there were no significant differences in any of these parameters between the control group and the high-pressure group. Histopathological examination demonstrated that there were obvious inflammatory cell infiltration and tissue damage in the control and high-pressure groups, which was prevented in the low- and moderate-pressure groups.

CONCLUSION

The perfusion pressure is an important factor that determines the extent of lung protection, and the use of pressures below 30 mmHg is optimal, with the safest and most effective range being 15-20 mmHg.