Forty-eight-week retrospective study of telbivudine and lamivudine treatment in patients with hepatitis B-related cirrhosis

The aim of this study was to evaluate the efficacy and safety of telbivudine 600 mg/day compared with lamivudine 100 mg/day for 48 weeks of treatment in patients with hepatitis B-related cirrhosis. Data were reviewed retrospectively from 165 hepatitis B-related cirrhotic patients (55 compensated patients and 110 decompensated) who received antiviral therapy with telbivudine or lamivudine. Serum alanine aminotransferase (ALT) and hepatitis B virus (HBV) DNA levels, hepatitis B e antigen (HBeAg) loss and seroconversion, histological improvement and various adverse events (AEs) were evaluated. Baseline characteristics were comparable. ALT levels declined but showed no significant difference in treatment with telbivudine or lamivudine (P > 0.05). Reduction in serum HBV DNA levels was evident by week 4 in compensated HBV-related cirrhosis patients (telbivudine, 2.34 log10 copies/mL; lamivudine, 2.07 log10 copies/mL; P = 0.02) and persisted by week 8. Patients administrated with telbivudine had slightly greater HBeAg loss and seroconversion than patients with lamivudine, but the difference was not statistically significant (P > 0.05). Accumulative HBeAg loss was seen at week 48 (25.0% vs 25.0% and 13.3% vs 10.0% for telbivudine vs lamivudine in compensated and decompensated cirrhotic groups, respectively), as well as HBeAg seroconversion (15.0% vs 8.3% and 8.9% vs 6.7%). Mean Knodell Histologic Activity Index scores decreased in both compensated and decompensated cirrhotic patients (3.92 vs 3.64, 3.85 vs 3.73, for telbivudine vs lamivudine). Telbivudine and lamivudine were both well tolerated with minor AEs. The results of this study support telbivudine as an effective therapy for patients with both compensated and decompensated HBV-related cirrhosis.

Inorganic phosphorus fractionation and its translocation dynamics in a low-P soil

The translocation of different inorganic phosphorus (Pi) forms in a low-P soil (Langfang experimental station, Hebei province, China) over time was investigated using P fractionation extraction and a (32)P tracer technique. The L-value and P availability of the soil was assessed using 5 different maize genotype (Zea mays L.) cultivars. The results showed that the different Pi fractions in the soil increased in the order of H(2)SO(4)-extractable P (Ca(10)-P) > Na(3)C(6)H(5)O(7)-Na(2)S(2)O(4)-extractable P (O-P) > NH(4)Ac-extractable P (Ca(8)-P) > NaHCO(3)-extractable P (Ca(2)-P), NH(4)F-extractable P (Al-P), NaOH-Na(2)CO(3)-extractable P (Fe-P), and the content of plant-unavailable P (Ca(10)-P + O-P) was high, up to 79.1%, which might be an important reason for P deficiency in this low-P soil. The (32)P tracer results showed that after the addition of (32)P-Pi to the soil with no P fertilizer applied for 25 d, 29.0% of (32)P was quickly transformed into Ca(2)-P (rapidly available P), and 66.1% of (32)P was transformed into Al-P, Fe-P and Ca(8)-P (slowly available P). Only 5.0% of (32)P was transformed into O-P and Ca(10)-P (plant-unavailable P). Moreover, in the soil with P fertilizer applied, (32)P transformation into Ca(2)-P increased, and the transformation into Ca(8)-P + Fe-P + AL-P and O-P, Ca(10)-P significantly decreased compared to the soil with no P fertilizer applied (p < 0.05). This result suggested a higher rate for water-soluble P transformation to slowly available and plant-unavailable P in P deficient soil than in soil with sufficient P. The results of maize L-value determination showed that different genotype maize cultivars had different soil P-use efficiency and low-P tolerance mechanisms. Low-P tolerant cultivar DSY-32 regulated soil P-use efficiency and plant P content according to exogenous P fertilizer application. However, another low-P tolerant cultivar, DSY-2, used soil P more efficiently, regardless of the application of exogenous P.

CM2 antigen, a potential novel molecule participating in glucuronide transport on rat hepatocyte canalicular membrane

The polarized molecules predominately distributing at hepatocyte canalicular surface play a vital role in disclosing the process of bile formation and etiopathogenisis of cholestatic live diseases. Therefore, it is important to find novel polarized molecules on hepatocyte canalicular membrane. In the present study, canalicular membrane vesicles (CMVs) isolated from rat hepatocyte by density gradient centrifugation were used as immunogens to produce hybridoma and 46 strains of monoclonal antibodies (mAb) against CMVs were obtained. With a series of morphological assay methods, including immunohistochemistry, immunofluorescence and immuno-electron microscope, the antigens recognized by canalicular mAb1 (CM1) and canalicular mAb2 (CM2) were confirmed to predominately distribute at hepatocyte canalicular membrane. Transport activity assay revealed that CM2 could inhibit ATP-dependent E217βG uptake of rat hepatocyte CMVs. Meanwhile, Western blotting analysis showed that the molecular mass of CM2 antigen was approximately 110kDa, which was much less than Mr 180kDa of multidrug resistance-associated protein 2 (MRP2) involved in glucuronide transport. These data indicated that CM2 antigen might be a potential novel molecule participating in glucuronide transport on the hepatocyte canalicular membrane.

Partial loss compensation in dielectric-loaded plasmonic waveguides at near infra-red wavelengths

We report on the fabrication and characterization of straight dielectric-loaded surface plasmon polaritons waveguides doped with lead-sulfide quantum dots as a near infra-red gain medium. A loss compensation of ~33% (an optical gain of ~143 cm⁻¹) was observed in the guided mode. The mode propagation, coupling efficiency and stimulated emission were characterized using leakage radiation microscopy. The guided mode signature was separated using spatial filters in the Fourier plane of the microscope for quantitative measurements of stimulated emission.

P4-01-17: TIMP-1 Over-Expression Confers Resistance of MCF-7 Breast Cancer Cells to Fulvestrant

Background

Endocrine resistance represents a major challenge in the management of estrogen receptor (ER) positive breast cancer. Currently no predictive biomarkers for endocrine resistance in ERpositive breast cancer patients are in clinical use.

In a clinical study, patients with metastatic breast cancer and high levels of serum Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) had less benefit from endocrine therapy than patients with a lower level of serum TIMP-1 [1].

Therefore, we evaluated the association between TIMP-1 and response to endocrine therapy using an in vitro approach.

We have previously presented initial results on TIMP-1 and response to endocrine therapy [2].

Materials and Methods: MCF-7 cells were stably transfected with pcDNA3.1(Hyg)-TIMP-1 plasmid, and a panel of 11 subclones with different expression levels of TIMP-1 was generated. TIMP-1 expression levels were confirmed using enzyme-linked immunosorbent assay (ELISA).

Four subclones with high or low TIMP-1 expression were analyzed for the growth response to estrogen, 4-hydroxytamoxifen and fulvestrant. These four subclones were analyzed for protein expression by western blotting. All subclones were analyzed by whole human genome oligo microarrays 4×44K for determination of gene expression levels. Data were analyzed using the limma R/Bioconductor package. Paired-end Solexa sequencing was applied to selected subclones with high and low TIMP-1 levels to identify transcriptomic changes.

Results: High expression of TIMP-1 was associated with resistance to fulvestrant, whereas growth response to either estrogen or 4-hydroxytamoxifen was independent of TIMP-1 expression levels. High expression of TIMP-1 protein and mRNA was associated with undetectable levels of progesterone receptor (PgR) protein and mRNA whereas ER protein and mRNA levels were unaffected by TIMP-1. To characterize the potential role of TIMP-1 in estrogen signaling we analyzed the expression of reported estrogen-responsive genes and no general change was observed. We identified genes that correlated positively or negatively to TIMP-1 expression. Among the identified genes was PgR, which is a direct target for ER.

Conclusion: Our data suggest that a high expression of TIMP-1 in vitro is associated with resistance to fulvestrant but not to 4-hydroxytamoxifen. Estrogen-regulated genes are not generally affected by changes in TIMP-1 expression levels and therefore TIMP-1 appears to affect endocrine resistance through other mechanisms than globally regulating ER signaling. However, high expression of TIMP-1 is associated with loss of PgR and this may be related to the resistance towards fulvestrant.

References:

[1] Lipton, A et al: Serum TIMP-1 and Response to the Aromatase Inhibitor Letrozole Versus Tamoxifen in Metastatic Breast Cancer. J Clin Oncol; 2008; 26;(16); 2653–8

[2] Effect of TIMP-1 Overexpression on Endocrine Sensitivity of MCF-7 ER-positive Human Breast Cancer Cells In Vitro. Cancer Res; 2009; 69(24 suppl); abstract nr 2029

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-01-17.

A modification of flattening filter free linac for IMRT

PURPOSE

This study investigates the benefits of a modified flattening filter free (FFF) linac over the standard (STD) linac equipped with the flattening filter. Energy and angular spread of the electron beam of the FFF linac were modified. Modification of FFF beam parameters is explored to maximize the monitor unit efficiency and to minimize the head scatter in IMRT delivery for large target volumes or targets lying away from the central axis.

METHODS

The EGSnrc code is used to model FFF and STD linacs and study basic beam properties for both linac types in various beam configurations. Increasing energy of FFF linac results in similar beam attenuation properties and maximized dose rate compared to STD linac. Matching beam attenuation properties allows a more direct exploration of beam flatness of FFF linac in regard to IMRT delivery, especially away from the central axis where the effective dose rate is considerably smaller than the one at the central axis. Flatness of open beam dose profile of FFF linac is improved by increasing the angular spread of the electron beam. The resulting dose rate within the treatment field and outside of the field (peripheral dose) are characterized and compared to the unmodified FFF and STD linacs,

RESULTS

In order to match beam penetration properties, the energy of FFF is adjusted from 6.5 to 8.0 MeV for small to medium field sizes and from 6.5 to 8.5 MeV for larger ones. Dose rate of FFF vs STD linac increased by a factor of 1.9 (6.5 MeV) and 3.4-4.1 (8.0-8.5 MeV). Adjusting the mean angular spread of the electron beam from 0 degrees to 5 degrees-10 degrees resulted in complete flattening of photon beam for field sizes between 10 x 10 cm2 and 15 x 15 cm2 and partial flattening for field sizes from 15 x 15 cm2 to 30 x 30 cm2. Values of angular spread > or =14 degrees are not recommended as they exceed the opening of the primary collimator, affecting the area at the edges of the field. FFF fields of sizes smaller than 6 x 6 cm2 are already flat and beam flattening is not necessary. Overall, the angular spread of 5 degrees-10 degrees is sufficient and can satisfactorily flatten open beam dose profiles even for larger field sizes. Increasing the electron beam angular spread amounts to a slight decrease of dose rate of FFF linac. However, for angular spread, 5 degrees-10 degrees dose rate factor of FFF vs STD is still about 1.6-2.6, depending on the field size (and the adjusted energy). Similarly, in case of peripheral dose, a moderate increase in dose can be observed for angular spread of 5 degrees-10 degrees and for field sizes 10 x 10 cm2 to 30 x 30 cm2. Lastly, beam flatness of not modified FFF linac can be conveniently described by an analytical function representing a ratio of STD vs FFF doses: 1 + b|r|(n).

CONCLUSIONS

A modified FFF beamline with increased energy and electron beam angular spread results in satisfactory flattened beam and high dose rate within the field. Peripheral dose remaining at similar (or smaller) level than that of STD linac for the same delivered dose within the treatment field.

Contactless measurement of critical current of high temperature superconductor tape by magnetic circuit

A method based on the principle of the magnetic circuit is proposed and realized for contactless measurement of critical current (I(c)) of high temperature superconductor tapes. This method has two unique features: first, it eliminates noises caused by mechanical fluctuations and thus makes high speed and high stability measurement possible and second, adapts for both Bi(2)Si(2)Ca(2)Cu(3)O(x) (Bi2223) and YBa(2)Cu(3)O(7-x) (YBCO) tape, which even has a magnetic substrate. Theoretical analysis is given and an apparatus for the reel-to-reel measurement has been constructed, by which continuous inspection of I(c) uniformity of YBCO and Bi2223 tapes measured at different speeds is reported.

Meta-analysis: polymorphisms in TNF-alpha gene promoter and Crohn's disease

BACKGROUND

Tumour necrosis factor alpha (TNF-alpha) is involved in the pathogenesis of Crohn's disease (CD). However, results on the association between the polymorphisms in TNF-alpha promoter and the risk of CD are inconsistent.

AIM

To perform a quantitative synthesis for the genetic polymorphisms in TNF-alpha promoter and CD risk.

METHODS

Databases were searched (up to 2009) and 31 studies were included. Risks of CD associated with the polymorphisms in TNF-alpha promoter were assessed.

RESULTS

Overall, individuals with -1031 TC+CC genotype had a slightly increased risk to develop CD compared with individuals with -1031 TT genotype (OR, 1.32; 95% CI, 1.03-1.70). In the further stratified analysis, we found Asians with the -1031T>C, -863 C>A and -857 C>T variant polymorphisms have almost one and a half CD risk compared with other genotypes (OR, 1.58; 95% CI, 1.16-2.15; OR, 1.55; 95% CI, 1.18-2.02; OR, 1.54; 95% CI, 1.19-1.99 respectively). We did not find -308 G>A variant associated with CD location and disease behaviours in stratified analysis.

CONCLUSIONS

TNF-alpha polymorphisms in the promoter region might be used as a biomarker for CD risk prediction. Larger studies with mixed ethnicity subjects and stratified by clinical and sub clinical characteristics are needed to validate our findings.

Passive magnetic field cancellation device by multiple high-Tc superconducting coils

A passive magnetic field cancellation device (PMFCD) is designed. The PMFCD could automatically cancel the field as an active cancellation system did; however it requires no power sources and feedback systems. The capability of the PMFCD is based on the principle that a closed loop can resist flux variation and keep the flux constant inside. The closed loop in the PMFCD is formed by connecting two pairs of high temperature superconductor Helmholtz coils with different radii in series. More important thing is that the ratio of the radius and the turn number between the coils has to satisfy a number of conditions, with which 100% cancellation can be reached. Theoretical methods to obtain the turn number ratio and radius ratio are the major part of the paper. Numerical simulation was followed, aiming to evaluate field distribution under a cancellation state and correct the theoretical values.

Experimental realization of subwavelength plasmonic slot waveguides on a silicon platform

We report the experimental realization of horizontal plasmonic slot waveguides capable of subdiffraction modal confinement at IR wavelengths. These waveguides have a propagation length of approximately 6 lambda(g) and are monolithically integrated with conventional silicon photonic waveguides on the same silicon-on-insulator platform. Direct coupling of light from the silicon waveguides to the plasmonic waveguides was achieved with an efficiency of 30% using taper-funnel couplers to obtain mode matching between the two waveguide systems.

Association of Collagen Type I α1 (COLIA1) Sp1 Polymorphism with Osteoporotic Fracture in Caucasian Post-menopausal Women: a Meta-analysis

This study was designed to summarize quantitatively the evidence for a relationship between collagen type I α1 (COLIA1) Sp1 polymorphism and osteoporotic fracture risk in Caucasian post-menopausal women. This meta-analysis included 16 studies, which analysed 2294 patients with fractures and 10285 controls. The combined results showed that there was a significant difference in genotype distribution (SS odds ratio [OR] 0.72; Ss OR 1.18; ss OR 1.97) between patients with fractures and controls. When stratifying by the fracture site, it was found that: (i) patients with vertebral fractures had a significantly higher frequency of the Ss genotype and a lower frequency of the SS genotype than controls; and (ii) patients with non-vertebral fractures had a significantly higher frequency of the ss genotype and a lower frequency of the SS genotype than controls. This meta-analysis suggests that the COLIA1 Sp1 polymorphism may be associated with osteoporotic fracture in Caucasian post-menopausal women.