Direct targeting of SUZ12/ROCK2 by miR-200b/c inhibits cholangiocarcinoma tumourigenesis and metastasis

Background:

The multidrug resistance and distant metastasis of cholangiocarcinoma result in high postoperative recurrence and low long-term survival rates. It has been demonstrated that the ectopic expression of miR-200 suppresses the multidrug resistance and metastasis of cancer. However, the expression and function of miR-200 in cholangiocarcinoma has not yet been described.

Methods:

In this study, we identified dysregulated microRNAs (miRNAs, miR) in cholangiocarcinoma tissue by microarray analysis, and subsequent real-time PCR and northern blot analyses validated the expression of candidate miR. We performed functional analyses and investigated the relationship between miR-200b/c expression and the properties of cholangiocarcinoma cells. A dual luciferase assay was applied to examine the effect of miRNAs on the 3′-UTR of target genes, and we demonstrated the function of the target gene by siRNA transfection identifying the downstream pathway via western blotting.

Results:

We found significantly downregulated expression of four miR-200 family members (miR-200a/b/c/429) and then confirmed that ectopic miR-200b/200c inhibits the migration and invasion of cholangiocarcinoma cells both in vitro and in vivo. We found that miR-200b/c influenced the tumourigenesis of cholangiocarcinoma cells including their tumour-initiating capacity, sphere formation, and drug resistance. We further found that miR-200b/c regulated migration and invasion capacities by directly targeting rho-kinase 2 and regulated tumorigenic properties by directly targeting SUZ12 (a subunit of a polycomb repressor complex).

Conclusion:

Our study shows that miR-200b/c has a critical role in the regulation of the tumorigenic and metastatic capacity of cholangiocarcinoma and reveals the probable underlying mechanisms.

A gEUD-based inverse planning technique for HDR prostate brachytherapy: feasibility study

PURPOSE

The purpose of this work was to study the feasibility of a new inverse planning technique based on the generalized equivalent uniform dose for image-guided high dose rate (HDR) prostate cancer brachytherapy in comparison to conventional dose-volume based optimization.

METHODS

The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO (Hybrid Inverse Planning Optimization) is compared with alternative plans, which were produced through inverse planning using the generalized equivalent uniform dose (gEUD). All the common dose-volume indices for the prostate and the organs at risk were considered together with radiobiological measures. The clinical effectiveness of the different dose distributions was investigated by comparing dose volume histogram and gEUD evaluators.

RESULTS

Our results demonstrate the feasibility of gEUD-based inverse planning in HDR brachytherapy implants for prostate. A statistically significant decrease in D10 or/and final gEUD values for the organs at risk (urethra, bladder, and rectum) was found while improving dose homogeneity or dose conformity of the target volume.

CONCLUSIONS

Following the promising results of gEUD-based optimization in intensity modulated radiation therapy treatment optimization, as reported in the literature, the implementation of a similar model in HDR brachytherapy treatment plan optimization is suggested by this study. The potential of improved sparing of organs at risk was shown for various gEUD-based optimization parameter protocols, which indicates the ability of this method to adapt to the user's preferences.

CpG7909 adjuvant enhanced immunogenicity efficacy in mice immunized with ESAT6-Ag85A fusion protein, but does not confer significant protection against Mycobacterium tuberculosis infection

AIMS

This study aimed to investigate the ability of CpG7909 adjuvant to enhance immunogenicity and protective efficacy of a subunit vaccine composed of ESAT6-Ag85A fusion protein (Pe685a) of Mycobacterium tuberculosis.

METHODS AND RESULTS

ELISA was used to detect specific antibody and IFN-γ expression in sera; ELISPOT, to detect IFN-γ expression in splenocytes; MTT assay and FACS, to detect T-lymphocytes proliferation in spleens; and RT-PCR, to detect cytokines expression in lungs of mice after immunization. Bacterial load and histopathological lesions in lungs or spleens of mice challenged with Myco. tuberculosis H37Rv strain were analysed. Compared with incomplete Freund's adjuvant, CpG7909 induced more potent production of Pe685a-specific IgG2a/IgG1 antibody and higher expression of IFN-γ in sera, stimulated more generation of antigen-specific IFN-γ-secreting splenocytes, enhanced frequencies of CD3(+) CD4(+) and CD3(+) CD8(+) T-lymphocytes in spleen and increased transcription of TNF-α, IFN-γ, IL-6 and TLR9 in lung. However, lower bacterial load in lung and less severe lung pathology were not observed in CpG7909 group mice.

CONCLUSIONS

CpG7909 is able to enhance immunological effects of Pe685a subunit vaccine, but does not confer significant protective efficacy against Myco. tuberculosis infection.

SIGNIFICANCE AND IMPACT OF THE STUDY

CpG7909 as an adjuvant of subunit vaccine against Myco. tuberculosis is worthy of further investigation.

Enrichment of epidermal stem cells of rats by Vario magnetic activated cell sorting system

Epidermal stem cells (ESCs) play an important role in skin homeostasis, wound repair, and tumorigensis which have great potential in scientific research and clinical application. So, the efficient isolation of these infrequent stem cells is very important for researchers to solve the problem of low purity and insufficient quantity of stem cells in vitro. The aim of this study was to investigate a method for the enrichment of ESCs by magnetic activated cell sorting system. The isolation strategy was CD71 depletion followed by α6-integrin positive selection. The percentage of α6(bri)CD71(dim) cells in isolated cells was 94.59%. Transmission electron microscopy results revealed that α6(bri) CD71(dim) cells exhibited some typical characteristics like progenitor cells, such as big nucleus, obvious nucleolus, large nuclear-cytoplasm ratio, and few organelles in cytoplasm. When cultured in vitro, the α6(bri)CD71(dim) cells had greater proliferating potential and higher colony-forming ability, and high levels of epidermal stem cell markers were expressed in our positive cells. ESCs have been successfully isolated from neonatal epidermis using Vario MACS and cultured in vitro. This isolation method is simple, fast, and inexpensive, providing an important tool for tissue engineering and cell transplantation studies.

Comparison of prediction equations to estimate glomerular filtration rate in Chinese patients with chronic kidney disease

AIM

We sought to evaluate the applicability of formulae based on serum creatinine (SC) levels in Chinese patients with chronic kidney disease (CKD).

MATERIALS AND METHODS

Three hundred and twenty-seven patients with CKD who had undergone (99m) Tc-DTPA glomerular filtration rate (GFR) estimation were enrolled. The Cockcroft-Gault equation, SC-reciprocal equation, Gate equation, Hull equation, Jelliffe-1973 equation, Jelliffe-1971 equation, Mawer equation, Bjornsson equation, reexpressed 6-variable MDRD equation and reexpressed 4-variable MDRD equation were compared. Using the (99m) Tc-DTPA GFR as the standard GFR (sGFR), the accuracy of estimated GFR was compared with sGFR in various stages of CKD.

RESULTS

Median per cents of the absolute difference ranged from 28.16% to 39.39%, accuracy with a deviation less than 30% ranging from 39.4% to 53.5%, accuracy with a deviation less than 50% ranging from 63.0% to 80.7%. None of the equations had accuracy up to the 70% level with a deviation less than 30% from sGFR. Bland-Altman analysis demonstrated that mean difference ranged from -2.42 to 16.39 mL/min/1.73 m(2), whereas precision ranged from 82.66 to 106.15 mL/min/1.73 m(2). However, the agreement limits of all the equations exceeded the prior acceptable tolerances defined as 60 mL/min/1.73 m(2). Linear regression showed that the slopes of regression line ranged from 0.37 to 0.54 and intercepts ranged from -12.10 to 3.86. When the overall performance as well as bias and accuracy were compared in different stages of CKD, GFR estimated by Jelliffe-1973 equation, Cockcroft-Gault equation and Bjornsson equation showed promising results.

CONCLUSION

When SC was measured by the enzymatic method, GFR estimation equations showed great bias in Chinese CKD patients. At present, the Jelliffe-1973 equation and Cockcroft-Gault equation may be more accurate in the Chinese ethnic group.

Temporal alterations and cellular mechanisms of transmural repolarization during progression of mouse cardiac hypertrophy and failure

AIM

The remodelling of transmural dispersion of repolarization (TDR) in human heart failure (HF) and in different animal models of cardiac hypertrophy or HF remains a controversial topic. We hypothesize that TDR may exhibit temporal alterations, depending on the stage of the disease.

METHODS

We systematically investigated the temporal alterations of TDR during the development of cardiac hypertrophy and HF in the mouse pressure-overload model using electrophysiological and molecular biology techniques.

RESULTS

A progressive prolongation of QT interval and changes in the amplitude of the J wave at 2, 5, 9 and 13 weeks were found in anesthetized aorta-banded mice. Action potential duration (APD) at 90% repolarization (APD90) in subendocardial myocytes of the left ventricular free wall remained unchanged at the hypertrophic stage (2 and 5 weeks), but was significantly prolonged in HF mice at 9 and 13 weeks. However, APD90 in subepicardial myocytes exhibited a significant prolongation at 2 weeks and did not progressively extend from 2 weeks to 13 weeks in banded mice. Thus, non-parallel prolongation of APD in subendocardial and subepicardial myocytes led to a reduction in TDR at hypertrophic stage and an amplification of TDR at HF stage. Further experiments revealed that asynchronous down-regulation of voltage-dependent potassium currents (I(to,f), I(K,slow) and I(ss)) and L-type calcium currents (I(Ca-L)) in subendocardial and subepicardial myocytes may contribute to the dynamic remodelling of transmural APD.

CONCLUSION

The two distinct TDR modes were revealed during the progression of mouse cardiac hypertrophy and failure, indicating that the remodelling of TDR depends on the stage of the disease.

Lef1 contributes to the differentiation of bulge stem cells by nuclear translocation and cross-talk with the Notch signaling pathway

Lymphoid enhancer binding factor-1 (Lef1) is an essential regulatory protein in the Wnt signal pathway, which controls cell growth and differentiation. Investigators in the field of skin biology have confirmed that multipotent bulge stem cells (BSCs) are responsible for hair follicle development and regeneration. However, the role of Lef1 remains poorly understood. In this study, we investigated the pattern of Lef1 expression at different stages of the hair growth cycle. Lef1 was strongly expressed during anagen but attenuated in both catagen- and telogen-phase hair follicles in vivo. When stem cells were induced to differentiate toward a hair fate in a co-culture system, Lef1 was notably up-regulated and accumulated in the nucleus, appearing to activate the target protein c-myc and jagged1. Simultaneously, the Wnt and Notch signaling pathways were co-activated, as confirmed by the increased expression of β-catenin and notch1. Plasmids expressing Lef1 and ΔNLef1, a construct in which the β-catenin-binding domain of Lef1 was deleted, were used to evaluate the effects of Lef1 on stem cell differentiation. Lef1 overexpression promoted bulge stem cell differentiation toward a hair fate, which was accompanied by the subsequent migration of β-catenin into the nucleus, whereas no changes were observed in the control group. Taken together, our results demonstrate that Lef1 plays an important role in bulge stem cell differentiation, promoting β-catenin translocation into the nucleus, activating downstream signaling molecules, eventually causing hair follicle bulge stem cells to adopt the hair fate.

Frequency stabilization of internal-mirror He-Ne lasers by air cooling

Instead of the traditional heating method, the cavity length of an internal-mirror He-Ne laser is controlled by air cooling which is implemented by a mini cooling fan. The responsive property of the cooling fan and the thermal expansion of the internal-mirror laser tube are investigated. According to these investigations, a controlling system is designed to drive the cooling fan controlling the cavity length of the laser. Then the frequency is stabilized by comparing the light intensities of two operating longitudinal modes. The results of beating with an iodine stabilized He-Ne laser show that a relative uncertainty (Δf/f-) of 4.3×10(-9) in 5 months, a frequency fluctuation of <1.4 MHz, and an Allan deviation of 6×10(-11) (τ=10,000 s) in 20 h are obtained.

Human positive coactivator 4 is a potential novel therapeutic target in non-small cell lung cancer

Transcriptional positive coactivator 4 (PC4) is a multifunctional nuclear protein that has important roles in DNA transcription, replication, repair and heterochromatinization. However, the role of PC4 in cancer remains to be clarified. Several studies propose that PC4 may act as a putative tumor suppressor. Here, we demonstrate for the first time that PC4 may represent a potential therapeutic target in non-small cell lung cancer (NSCLC). PC4 protein expression is significantly upregulated in NSCLC carcinoma tissues compared with their adjacent noncancerous counterparts as shown by immunohistochemical staining and western blotting in 104 pairs of formalin-fixed human NSCLC specimens and 6 fresh NSCLC samples. Knockdown of PC4 expression by sequence-specific small interfering RNA (siRNA) in human NSCLC cells (A549, H460 and H358) significantly inhibits the growth of cancer cells by the induction of cell cycle arrest and the increase of cell apoptosis in vitro. Interrupting the PC4 signaling pathway by injection of the PC4 siRNA liposome complex produced an effective regression of pre-established A549 cell xenografts in mice through growth inhibition and increased apoptosis. These results indicated that PC4 could be an attractive new therapeutic target for the treatment of NSCLC.

Cellular stress response in Eca-109 cells inhibits apoptosis during early exposure to isorhamnetin

The flavonol aglycone isorhamnetin shows anti-proliferative activity in a variety of cancer cells. Previous work, from our laboratory showed that isorhamnetin inhibits the proliferation of human esophageal squamous carcinoma Eca-109 cells in vitro, but only after 72 h of exposure. This led us to propose that isorhamnetin exposure induces a cellular stress response that inhibits the antiproliferative and apoptotic effects of the compound during early exposure. To test this hypothesis, the present study examined the effects of isorhamnetin on Eca-109 cells during the first 72 h of exposure. Cell growth was assessed using the trypan blue exclusion assay, and expression of IκBα, NF-κB/p65, NF-κB/p50, phospho-Akt, Bcl-2, COX-2, Mcl-1, Bax, p53 and Id-1 were analyzed by Western blot. During the first 72 h of exposure, NF-κB/p65 and NF-κB/p50 accumulated in nuclei and expression of COX-2, Bcl-2 and Mcl-1 increased. In contrast, expression of IκBα and Bax fell initially but later increased. Expression of phospho-Akt and p53 showed no detectable change during the first 48 h. Pretreatment with the NF-κB inhibitor MG132 before exposure to isorhamnetin blocked the nuclear accumulation of p50 and p65, thereby inhibiting cell proliferation. These results show that during early exposure of Eca-109 cells to isorhamnetin, the NF-κB signaling pathway is activated and COX-2 expression increases, and this increase in expression partially inhibits isorhamnetin-induced apoptosis. Beyond 72 h of exposure, however, the apoptotic effect of isorhamnetin dominates, leading to inhibition of the NF-κB pathway and of cellular proliferation. These results will need to be taken into account when exploring the use of isorhamnetin against cancer in vivo.

Leveraging bimodal kinetics to improve detection specificity

Optical microcavities are high sensitivity transducers able to detect single nanoparticles and molecules. However, the specificity of detection is dependent on the availability of an appropriate targeting moiety with minimal cross-reactivity. In the present work, an alternative approach is shown. Namely, using biotin-functionalized toroidal microcavities, the dissociation constant of biotin to two different streptavidin complexes (free and polystyrene bead) is determined. Based on the difference in affinity and in mass transport, the two complexes are identified from a mixture. By leveraging information in the binding site, improved specificity can be achieved.

Correlation between Thyroid Nodule Calcification Morphology on Ultrasound and Thyroid Carcinoma

OBJECTIVE: This study investigated the detection of thyroid nodule calcifications on ultrasound and their relationship to thyroid carcinoma. METHODS: Microcalcifications (≤ 2 mm) and macrocalcifications (> 2 mm) on preoperative ultrasound examination of thyroid and lymph nodes were compared with postoperative pathological diagnoses in 4186 patients undergoing thyroid surgery. RESULTS: Higher incidences of micro- and macrocalcifications were found in patients with thyroid carcinoma than in those with benign disease. The incidence of malignant disease was significantly higher in patients with microcalcifications than those with macrocalcifications, suggesting that the presence of microcalcifications is a better predictor of malignant thyroid carcinoma than other calcification types. The specificity of microcalcifications for a diagnosis of malignant thyroid carcinoma was 96.5%. Microcalcifications were significantly more frequent in patients aged ≤ 45 years, but there was no difference between genders. The incidence of malignancy was significantly higher in patients with single nodule calcifications than in those with multiple nodule calcifications. Lymph node calcifications were seen in 12 patients, all of whom had papillary carcinoma. CONCLUSIONS: Thyroid microcalcifications are strongly associated with thyroid carcinoma, especially micropapillary carcinoma. When cervical lymph node calcification is present, immediate surgery is required.

Mitochondrial apoptotic pathways: a mechanism for low androgen-induced vascular endothelial injury in male rats

The aim of the study was to investigate the role of mitochondrial apoptotic pathways in vascular endothelial injury in male rats with low androgen. 8 week-old adult male Sprague-Dawley (SD) rats were randomly divided into 3 groups (n=6/each group): control group, castrated group (low androgen), and replacement group (given androgen after castration). After 10 weeks, endothelial structure was observed by general light microscope and transmission electron microscope (TEM) respectively. Isolated mitochondria and mitochondrial membrane potential (MMP) were detected by fluorescence to access mitochondrial function. Chromatin degradation was measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine-biotin nick end labeling (TUNEL) staining method. The mRNA and protein of bcl-2, cytochrome C (Cyt C), caspase-9, and caspase-3 were analyzed for apoptosis. Cell shrinkage and condensed chromatin, less mitochondria and a fall in MMP levels were observed in the castrated group, along with more apoptotic endothelial cells. Bcl-2 level was reduced and the expression of caspase-9, caspase-3 and Cyt C were elevated in the castrated group (p<0.05). But there was no significant difference between the replacement group and the control group (p>0.05). It was concluded that low androgen caused vascular endothelial damage. It may be, at least in part, related with the activating mitochondrial apoptotic pathways.

Window into the complexities of chromosome interactomes

DNA is folded into increasingly complex yet highly mobile structures to organize the chromosomes. In the interphase nucleus, chromosomes or part of the chromosomes encounter one another preferentially at the boundaries between chromosomal territories. Although this situation implies that the preferred chromosomal neighborhood is a key determinant of interactions between chromosomes, what this means in functional terms is currently not well understood. Using the H19 imprinting control region as a window, it has been demonstrated that epigenetic information of the primary chromatin fiber has dual functions. Thus, epigenetic marks not only influence the proximity between chromatin fibers but also transfer epigenetic states between chromatin fibers both in cis and in trans. High-throughput sequence and DNA fluorescence it situ hybridization (FISH) analyses reveal that these features require chromatin movements that are restricted in space and time. The mechanisms involved in the establishment of chromosome interactomes may provide insight of fundamental importance into pivotal regulatory processes in the nucleus, such as the coordination of transcriptional programs and replication timing.

Radiobiological and Dosimetric Analysis of Daily Megavoltage CT Registration on Adaptive Radiotherapy with Helical Tomotherapy

Pre-treatment patient repositioning in highly conformal image-guided radiation therapy modalities is a prerequisite for reducing setup uncertainties. In Helical Tomotherapy (HT) treatment, a megavoltage CT (MVCT) image is usually acquired to evaluate daily changes in the patient's internal anatomy and setup position. This MVCT image is subsequently compared to the kilovoltage CT (kVCT) study that was used for dosimetric planning, by applying a registration process. This study aims at investigating the expected effect of patient setup correction using the Hi-Art tomotherapy system by employing radiobiological measures such as the biologically effective uniform dose ([Formula: see text]) and the complication-free tumor control probability ( P+). A new module of the Tomotherapy software (TomoTherapy, Inc, Madison, WI) called Planned Adaptive is employed in this study. In this process the delivered dose can be calculated by using the sinogram for each delivered fraction and the registered MVCT image set that corresponds to the patient's position and anatomical distribution for that fraction. In this study, patients treated for lung, pancreas and prostate carcinomas are evaluated by this method. For each cancer type, a Helical Tomotherapy plan was developed. In each cancer case, two dose distributions were calculated using the MVCT image sets before and after the patient setup correction. The fractional dose distributions were added and renormalized to the total number of fractions planned. The dosimetric and radiobiological differences of the dose distributions with and without patient setup correction were calculated. By using common statistical measures of the dose distributions and the P+ and [Formula: see text] concepts and plotting the tissue response probabilities vs. [Formula: see text] a more comprehensive comparison was performed based on radiobiological measures. For the lung cancer case, at the clinically prescribed dose levels of the dose distributions, with and without patient setup correction, the complication-free tumor control probabilities, P+ are 48.5% and 48.9% for a [Formula: see text] of 53.3 Gy. The respective total control probabilities, PB are 56.3% and 56.5%, whereas the corresponding total complication probabilities, PI are 7.9% and 7.5%. For the pancreas cancer case, at the prescribed dose levels of the two dose distributions, the P+ values are 53.7% and 45.7% for a [Formula: see text] of 54.7 Gy and 53.8 Gy, respectively. The respective PB values are 53.7% and 45.8%, whereas the corresponding PI values are ~0.0% and 0.1%. For the prostate cancer case, at the prescribed dose levels of the two dose distributions, the P+ values are 10.9% for a [Formula: see text] of 75.2 Gy and 11.9% for a [Formula: see text] of 75.4 Gy, respectively. The respective PB values are 14.5% and 15.3%, whereas the corresponding PI values are 3.6% and 3.4%. Our analysis showed that the very good daily patient setup and dose delivery were very close to the intended ones. With the exception of the pancreas cancer case, the deviations observed between the dose distributions with and without patient setup correction were within ±2% in terms of P+. In the radiobiologically optimized dose distributions, the role of patient setup correction using MVCT images could appear to be more important than in the cases of dosimetrically optimized treatment plans were the individual tissue radiosensitivities are not precisely considered.

A predictive value of hyponatremia for poor outcome and cerebral infarction in high-grade aneurysmal subarachnoid haemorrhage patients

BACKGROUND

The clinical significance of hyponatremia has not been investigated in high-grade aneurysmal subarachnoid haemorrhage (aSAH) patients. Thus, we assessed the predictive value of hyponatremia for poor outcome or cerebral infarction in high grade patients (the World Federation of Neurological Surgeons Scale (WFNS) grade 4 or 5) after aSAH.

METHODS

Patients with WFNS grade 4 or 5 after aSAH were selected into this study between January 2005 and January 2008. In the same period, patients with WFNS grade 1, 2 or 3 after aSAH (low grade) were also chosen into this study. Hyponatremia was determined with serum sodium measurements obtained within 9 days after aSAH. Prognosis of patients was estimated with Glasgow Outcome Scale at 3 months. The relationship between hyponatremia and poor outcome and association of hyponatremia and cerebral infarction were analysed, respectively.

RESULTS

A total of 124 high-grade patients were included in this study. Of those, 78 patients developed hyponatremia. Hyponatremia developed in 32.3% of cases between days 1 and 3 after aSAH, and 30.6% developed hyponatremia after 3 days post-aSAH. Multivariable analysis revealed that hyponatremia was not correlated with poor outcome in high-grade aSAH patients. Furthermore, only late-onset hyponatremia was correlated with cerebral infarction in these patients. Meanwhile, there was no significant correlation between hyponatremia and poor outcome or cerebral infarction in 259 low-grade aSAH patients.

CONCLUSIONS

Hyponatremia does not predict poor outcome in all-grade aSAH patients. However, late-onset hyponatremia in high-grade aSAH patients is associated with cerebral infarction. Therefore, the appropriate management of hyponatremia could be beneficial in those patients.

Comparison of the helical tomotherapy against the multileaf collimator-based intensity-modulated radiotherapy and 3D conformal radiation modalities in lung cancer radiotherapy

OBJECTIVES

The aim of this study was to compare three-dimensional (3D) conformal radiotherapy and the two different forms of IMRT in lung cancer radiotherapy.

METHODS

Cases of four lung cancer patients were investigated by developing a 3D conformal treatment plan, a linac MLC-based step-and-shoot IMRT plan and an HT plan for each case. With the use of the complication-free tumour control probability (P(+)) index and the uniform dose concept as the common prescription point of the plans, the different treatment plans were compared based on radiobiological measures.

RESULTS

The applied plan evaluation method shows the MLC-based IMRT and the HT treatment plans are almost equivalent over the clinically useful dose prescription range; however, the 3D conformal plan inferior. At the optimal dose levels, the 3D conformal treatment plans give an average P(+) of 48.1% for a effective uniform dose to the internal target volume (ITV) of 62.4 Gy, whereas the corresponding MLC-based IMRT treatment plans are more effective by an average ΔP(+) of 27.0% for a Δ effective uniform dose of 16.3 Gy. Similarly, the HT treatment plans are more effective than the 3D-conformal plans by an average ΔP(+) of 23.8% for a Δ effective uniform dose of 11.6 Gy.

CONCLUSION

A radiobiological treatment plan evaluation can provide a closer association of the delivered treatment with the clinical outcome by taking into account the dose-response relations of the irradiated tumours and normal tissues. The use of P - effective uniform dose diagrams can complement the traditional tools of evaluation to compare and effectively evaluate different treatment plans.

Multivariate analysis by Cox proportional hazard model on prognosis of patient with epithelial ovarian cancer

PURPOSE OF INVESTIGATION

To evaluate the influence of various clinicopathological and biochemical factors on the survival of patients with epithelial ovarian cancer (EOC) after radical resection.

METHODS

A retrospective analysis was made for 183 cases of epithelial ovarian cancer treated from January 1997 to January 2001. Six clinicopathological factors, including menopause, histological type, histological grade, lymph node metastasis, FIGO stage and chemotherapy that could possibly influence survival were selected. The expression of COX-2 and VEGF protein as two biochemical factors were detected in EOC tissues using immunohistochemical staining. Independent variables were first analyzed by univariate methods. A multivariate analysis of these variables was performed using the Cox proportional hazard regression model.

RESULTS

The ovarian cumulative survival rate was 48.71% for three years and 30.71% for five years. Univariate analysis of overall survival involving all the patients indentified five factors that were associated with a significant outcome: menopause, histological grade, FIGO stage, COX-2 or VEGF expression level (p < 0.05). The expression of COX-2 was positive in 140 (76.5%) of these 183 cases, but was not associated with menopause, histological type, histological grade, lymph node metastasis or FIGO stage. Median survival time was 24.56 months for the patients with COX-2 positive expression, and 47.52 months for those with COX-2 negative expression (p < 0.05). VEGF protein overexpression was examined in 117 (63.93%) of all 183 cases, and was associated with lymph node metastasis (p <0.05), but not associated with menopause, histological grade, histological type or FIGO stage. The median survival time was 23.36 months for the patients with VEGF detected expression, and 42.09 months for those with no VEGF detected expression (p < 0.05). When the interactive effects of these factors were taken into account, COX-2 expression, FIGO stage, VEGF expression and histological grade were the four most important prognostic factors by multivariate analysis using the Cox proportional hazards model. Risk of death for the patients with COX-2 positive expression was 2.8 times than that with COX-2 negative expression, and for FIGO stage, VEGF expression and histological grade, risk of death was 2.2, 2.1, and 1.84 times, respectively.

CONCLUSION

COX-2 expression, FIGO stage, VEGF expression and histological grade are the most important prognostic factors for EOC after curative resection.

Recombinant Mycobacterium smegmatis expressing an ESAT6-CFP10 fusion protein induces anti-mycobacterial immune responses and protects against Mycobacterium tuberculosis challenge in mice

The currently used vaccine against tuberculosis, Bacille Calmette-Guérin (BCG), has variable efficacy, so new vaccine development is crucial. In this study, we evaluated a recombinant vaccine prepared from non-pathogenic Mycobacterium smegmatis (rMS) that expresses a fusion of early secreted antigenic target 6-kDa antigen (ESAT6) and culture filtrate protein 10 (CFP10). C57BL/6 mice were immunized with the rMS expressing the ESAT6-CFP10 fusion protein (rM.S-e6c10) or with BCG. The mice in the rM.S-e6c10 group had a significantly higher titre of anti-ESAT6-CFP10 antibodies than did animals in the BCG or saline groups. Spleen cells from rM.S-e6c10-immunized mice exhibited a cytotoxic response to ESAT6 and CFP10-expressed target cells, but spleen cells from animals in the other groups did not. Levels of IFN-γ and IL-2 production by purified T cells from spleens were significantly higher in rM.S-e6c10 group than in BCG group. Finally, after M. tuberculosis (MTB)-challenged mice, dramatic reduction in the numbers of MTB colony-forming units (CFUs) in the lungs was observed for the mice immunized with the rMS. The protective efficacy of rM.S-e6c10 and BCG vaccination was similar based on measures of MTB burden and lung pathology. Our data indicate that the recombinant M. smegmatis vaccine expressing the ESAT6-CFP10 fusion protein has potential in clinic application.

Addition of insulin lispro protamine suspension or insulin glargine to oral type 2 diabetes regimens: a randomized trial

AIMS

The addition of basal insulin to existing oral therapy can help patients with type 2 diabetes (T2D) achieve glycaemic targets. This study compares the efficacy and safety of insulin lispro protamine suspension (ILPS) and insulin glargine in insulin-naive patients with T2D and inadequate control on oral antihyperglycaemic medication (OAM).

MATERIALS AND METHODS

An open-label, randomized, multicentre, multinational 24-week study of 471 patients receiving ≥2 OAMs for ≥3 months with a body mass index between 25 and 45 kg/m(2) and HbA1c 7.5-10.0% was conducted. ILPS was injected once or twice daily vs. glargine injected once daily plus prestudy OAMs. Primary objective compared the HbA1c change from baseline.

RESULTS

HbA1c change from baseline to endpoint was similar in both groups [-1.46% (ILPS) and -1.41% (glargine)]. Least-squares mean difference (95% CI) for HbA1c (-0.05 [-0.21, 0.11]%), glycaemic variability (0.06 [-0.06, 0.19] mmol/l) and weight change (-0.01 [-0.61, 0.59] kg) showed non-inferiority (margins of 0.4%, 0.8 mmol/l and 1.5 kg, respectively). Percentages of patients achieving HbA1c <7.0% were 43.8% ILPS and 41.2% glargine. Mean daily insulin dose was 0.39 vs. 0.35 U/kg (p = 0.02) and weight gain was 1.04 vs. 1.07 kg for ILPS vs. glargine (p = 0.98). Overall hypoglycaemia (episodes/patient/year) was similar for ILPS and glargine (24.2 ± 28.8 vs. 23.0 ± 30.9); nocturnal (6.1 ± 10.6 vs. 4.1 ± 9.4, p < 0.001) rates were higher for ILPS. Severe hypoglycaemia was higher for ILPS vs. glargine (n = 9 vs. n = 2; p = 0.04).

CONCLUSIONS

At endpoint, ILPS was non-inferior to glargine in HbA1c change from baseline, but associated with increased risk of hypoglycaemia.

A practical method to detect target failure of a helical tomotherapy unit

PURPOSE

Helical tomotherapy has been in clinical use for several years. One of the issues with a helical tomotherapy unit is the failure of detection of the x-ray target. In this study, we are proposing a method to detect potential failure of the x-ray target.

METHODS

Currently, on-board detector data from a helical tomotherapy unit are collected and sent to TomoTherapy Inc. for comparison with the so-called gold standard for the unit. However, this is sometimes time-consuming. Furthermore, the clinical medical physicists have no access to this comparison procedure. In this study, we developed a practical method to detect target failure based on one of the monthly quality assurance (QA) procedures. The commissioning cross-plane profiles were used as the comparison baseline. Larger EDR2 film (35×43 cm) were set at source-axis distance (SAD) (85 cm) and shot with 1.5 cm solid water as build-up material and 10 cm solid water as backscattering material. Cross-plane profiles obtained from the EDR2 film were compared with the commissioning profiles.

RESULTS

When the cross-plane profiles from monthly QA have 1° degree difference from the commissioning profiles, it is time that the target be changed.

CONCLUSION

This method enables the clinical medical physicists to easily evaluate the target status and to help improving the quality assurance of a helical tomotherapy unit.

Tradeoffs for assuming rigid target motion in Mlc-based real time target tracking radiotherapy: a dosimetric and radiobiological analysis

We report on our assessment of two types of real time target tracking modalities for lung cancer radiotherapy namely (1) single phase propagation (SPP) where motion compensation assumes a rigid target and (2) multi-phase propagation (MPP) where motion compensation considers a deformable target. In a retrospective study involving 4DCT volumes from six (n=6) previously treated lung cancer patients, four-dimensional treatment plans representative of the delivery scenarios were generated per modality and the corresponding dose distributions were derived. The modalities were then evaluated (a) Dosimetrically for target coverage adequacy and normal tissue sparing by computing the mean GTV dose, relative conformity gradient index (CGI), mean lung dose (MLD) and lung V(2)0; (b) Radiobiologically by calculating the biological effective uniform dose (D) for the target and organs at risk (OAR) and the complication free tumor control probability (P(+)). As a reference for the comparative study, we included a 4D Static modality, which was a conventional approach to account for organ motion and involved the use of individualized motion margins. With reference to the 4D Static modality, the average percent decrease in lung V(20) and MLD were respectively (13.1-/+6.9) % and (11.4-/+ 5.6)% for the MPP modality, whereas for the SPP modality they were (9.4-/+6.2) % and (7.2-/+4.7) %. On the other hand, the CGI was observed to improve by 15.3-/+13.2 and 9.6-/+10.0 points for the MPP and SPP modalities, respectively while the mean GTV dose agreed to better than 3% difference across all the modalities. A similar trend was observed in the radiobiological analysis where the P(+) improved on average by (6.7-/+4.9) % and (4.1-/+3.6) % for the MPP and SPP modalities, respectively while the D computed for the OAR decreased on average by (6.2-/+3.6) % and (3.8-/+3.5) % for the MPP and SPP tracking modalities, respectively. The D calculated for the GTV for all the modalities was in agreement to better than 2% difference. In general, respiratory motion induces target displacement and deformation and therefore the complex MPP real time target tracking modality is the preferred. On the other hand, the SPP approach affords simplicity in implementation at the expense of failing to account for target deformation. Radiobiological and dosimetric analyses enabled us to investigate the consequences of failing to compensate for deformation and assess the impact if any on the clinical outcome. While it is not possible to draw any general conclusions on a small patient cohort, our study suggests that the two tracking modalities can lead to comparable clinical outcomes and as expected are advantageous when compared with the static conventional modality.