Using Monte Carlo simulation to assess variability and uncertainty of tobacco consumption in a city by sewage epidemiology

OBJECTIVE

To use Monte Carlo simulation to assess the uncertainty and variability of tobacco consumption through wastewater analysis in a city.

METHODS

A total of 11 wastewater treatment plants (WWTPs) (serving 2.2 million people; approximately 83% of urban population in Dalian) were selected and sampled. By detection and quantification of principal metabolites of nicotine, cotinine (COT) and trans-3'-hydroxycotinine (OH-COT), in raw wastewater, back calculation of tobacco use in the population of WWTPs can be realised.

RESULTS

COT and OH-COT were detected in the entire set of samples with an average concentration of 2.33 ± 0.30 and 2.76 ± 0.91 µg/L, respectively. The mass load of absorbed NIC during the sampling period ranged from 0.25 to 4.22 mg/day/capita with an average of 1.92 mg/day/capita. Using these data, we estimated that smokers in the sampling area consumed an average of 14.6 cigarettes per day for active smoker. Uncertainty and variability analysis by Monte Carlo simulation were used to refine this estimate: the procedure concluded that smokers in Dalian smoked between 10 and 27 cigarettes per day. This estimate showed good agreement with estimates from epidemiological research.

CONCLUSIONS

Sewage-based epidemiology may be a useful additional tool for the large-scale monitoring of patterns of tobacco use. Probabilistic methods can be used to strengthen the reliability of estimated use generated from wastewater analysis.

[Comparison of jaw thrust and trapezius squeezing test as indicators for laryngeal mask airway insertion in infants and young children]

OBJECTIVE

To compare the effectiveness of the jaw thrust and the trapezius squeezing test(TST) for laryngeal mask airway (LMA) insertion in infants and children under sevoflurane anesthesia.

METHODS

A total of 100 children aged from 6 month to 3 years, American Society of Anesthesiologists(ASA) Ⅰ-Ⅱ and undergoing minor operation were enrolled from January to June 2015 in Tianjin Children's Hospital. The patients were randomly divided into jaw thrusting group (Group J, n=50)and trapezius squeezing group(Group T, n=50). Anesthesia was induced with sevoflurane. When children's eyelash reflex lose, jaw thrust/trapezius squeeze was applied every 15 seconds.It's considered that the depth of anesthesia was not enough, and test reaction was positive if any movements of body, limbs or toes were found at the point of test. Sevoflurane should be keep on inhalation until negative test reaction was appeared. Then LMA was inserted immediately.The time required for the negative test, end-tidal sevoflurane concentrations (ETsev), the index of Narcotrend anesthesia monitor(NT), the occurrence of gross purposeful movements, coughing, gagging, breath-holding, laryngospasm or an SpO2 < 90% during LMA insertion in two groups of patients were observed and recorded. The condition of LMA insertion and the rate of successful insertion were evaluated. The blood pressure(BP), heart rate(HR) and SpO2 were also recorded before and after LMA insertion.

RESULTS

In group J and group T, the time required for the negative test was (2.31±1.03) vs (2.85±0.97)min(t=-2.462, P<0.05), ETsev was(3.25±1.02)% vs (3.81±0.87) %(t=-2.361, P<0.05), the depth of anesthesia NT index was(50.41±5.38) vs (41.32±4.92)(t=3.021, all P<0.05). All of above results were significantly different. The successful rate of the first attempt LMA insertion was 78% vs 100%(χ(2)=12.36 , P<0.01), respectively. The differences had statistical significance. The conditions of LMA insertion in group T were superior to those in group J. The incidences of gross purposeful movements, coughing, gagging, breath-holding and SpO2<90% during LMA insertion in group J were 20%, 16%, 10%, 14% and 8%, which were higher than those in group T (2%, 2%, 0, 2%, 0), the differences were significant(χ(2)=8.27, 5.98, 5.26, 4.89, 4.17, all P<0.05). No significant change in blood pressure, heart rate and SpO2 were found before and after inserting LMA in two groups.

CONCLUSION

The trapezius squeezing test is a superior indicator of adequate condition for LMA insertion compared to the jaw thrust in infants and young children under sevoflurane anesthesia.

Hair follicle transcriptome profiles during the transition from anagen to catagen in Cashmere goat (Capra hircus)

Previous molecular genetic studies of the goat hair life cycle have focused primarily on a limited number of genes and proteins. To identify additional genes that may play important roles in hair follicle cycle regulation, Illumina sequencing technology was used to catalog differential gene expression profiles in the hair growth cycle (anagen to catagen) of goat, comparing the primary hair follicle with the secondary hair follicle. There were 13,769 and 12,240 unigenes assembled from the reads obtained from primary hair follicle and secondary hair follicle, respectively. Genes encoding keratin proteins and keratin-associated proteins were the most highly expressed. A total of 5899 genes were differentially expressed in anagen vs catagen primary hair follicles, with 532 genes up-regulated and 5367 genes down-regulated. A total of 5208 genes were differentially expressed in anagen vs catagen secondary hair follicle, including 545 genes that were up-regulated and 4663 genes that were down-regulated. Numerous hair growth genes are expressed in the goat hair follicle, of which 73 genes showed co-up-regulation in both hair follicles during the anagen stage. Many of these up-regulated genes, such as STC2, VEGFR, and ROR2, are known to be transfactors in the process of cell differentiation and in the cell cycle. The differential gene expression profiles between primary hair follicles and secondary hair follicles obtained provide a foundation for future studies examining the network of gene expression controlling hair growth cycle in Cashmere goat.

Role of VEGF gene polymorphisms in the clinical outcome of non-small cell lung cancer

This report details a study conducted to assess the role of VEGF gene polymorphisms in the prognosis of advanced non-small cell lung carcinoma (NSCLC). Samples obtained from 210 advanced NSCLC patients admitted at the Huaihe Hospital of Henan University between January 2010 and December 2011 were recruited for this study. The VEGF -2578C/A (rs699947), +936C/T (rs3025039), and -634G/C (rs2010963) genotypes were analyzed by polymerase chain reaction-restriction fragment length polymorphism. We discovered, by logistic regression analysis, that the TT genotype of VEGF +936C/T was associated with more complete response + partial response to chemotherapy, compared to the CC genotype (odds ratio (OR) = 4.78, 95% confidence interval (CI) = 1.34-25.85). We also found a correlation between the TT genotype of VEGF +936C/T and lower risk of death from all causes compared to the CC genotype (OR = 0.26, 95%CI = 0.10-0.69), using the Cox proportional hazard model (after adjusting for potential confounding factors). In conclusion, we discovered that the VEGF +936C/T gene polymorphism influences the response to chemotherapy and overall survival of NSCLC patients.

Relationships and redundancies of selected hemodynamic and structural parameters for characterizing virtual treatment of cerebral aneurysms with flow diverter devices

BACKGROUND AND PURPOSE

To quantify the relationship and to demonstrate redundancies between hemodynamic and structural parameters before and after virtual treatment with a flow diverter device (FDD) in cerebral aneurysms.

METHODS

Steady computational fluid dynamics (CFD) simulations were performed for 10 cerebral aneurysms where FDD treatment with the SILK device was simulated by virtually reducing the porosity at the aneurysm ostium. Velocity and pressure values proximal and distal to and at the aneurysm ostium as well as inside the aneurysm were quantified. In addition, dome-to-neck ratios and size ratios were determined. Multiple correlation analysis (MCA) and hierarchical cluster analysis (HCA) were conducted to demonstrate dependencies between both structural and hemodynamic parameters.

RESULTS

Velocities in the aneurysm were reduced by 0.14m/s on average and correlated significantly (p<0.05) with velocity values in the parent artery (average correlation coefficient: 0.70). Pressure changes in the aneurysm correlated significantly with pressure values in the parent artery and aneurysm (average correlation coefficient: 0.87). MCA found statistically significant correlations between velocity values and between pressure values, respectively. HCA sorted velocity parameters, pressure parameters and structural parameters into different hierarchical clusters. HCA of aneurysms based on the parameter values yielded similar results by either including all (n=22) or only non-redundant parameters (n=2, 3 and 4).

CONCLUSION

Hemodynamic and structural parameters before and after virtual FDD treatment show strong inter-correlations. Redundancy of parameters was demonstrated with hierarchical cluster analysis.

Relationship between serum leptin levels and non-small cell lung carcinoma: a meta-analysis

In this study, we analyzed the association between serum leptin levels and non-small cell lung carcinoma (NSCLC). By examining English and Chinese databases, we identified potential relevant studies for statistical analysis. Human-associated case-control studies evaluating the association between serum leptin levels and NSCLC according to the random-effect model were retrieved and extracted data were statistically analyzed. We identified 7 case-control studies evaluating the correlation between serum leptin levels and NSCLC, which included 705 subjects (390 NSCLC patients and 315 healthy participants). Negative associations were investigated between serum leptin levels and NSCLC [standardized mean difference (SMD) = 0.96, 95% confidence interval (CI) = 0.13-1.79, P = 0.023). Ethnicity-stratified analysis revealed there was no elevated leptin serum levels in NSCLC development in both Asians (SMD = 0.34, 95%CI = -0.10-0.79, P = 0.132) and Caucasians (SMD = 1.42, 95%CI = -0.09-2.93, P = 0.064). Sample size-stratified analysis of the association between serum leptin levels and NSCLC were found in studies of small sample size (SMD = 0.73, 95%CI = 0.04-1.41, P = 0.038), but not in studies of large sample size (SMD = 1.24, 95%CI = -0.52-3.01, P = 0.166). In the method-stratified subgroup analysis, serum leptin level was not correlated with NSCLC using a immunoradiometric assay method (SMD = 0.82, 95%CI = -1.38-3.03, P = 0.465). Determining the levels of the blood-based marker leptin may provide predictive information for NSCLC diagnosis.

Cobalt chromium-based biodegradable polymer sirolimus-eluting stent: rationale, evidence and clinical experience

Metallic drug-eluting stents (DES) are the first choice for percutaneous coronary interventional treatment of coronary artery disease at present. Although they have overcome some disadvantages and limitations of plain balloon angioplasty and bare-metal stents, chronic local inflammatory reactions related to permanent polymer existence and poor vascular healing after first generation DES implantation may translate into the increased risk of late and very late stent thrombosis. There have been technological developments in stent design, materials and coatings, including more conformable platform designs, biocompatible or biodegradable polymers and improved kinetics of drug release. The newer generation DES have proven superior to previous DES technology in terms of both safety and efficacy. Accumulating evidence has suggested that DES with cobalt chromium stent platform, modified biodegradable polymer coatings, and rapamycin derivative drugs are associated with improved clinical outcomes. Currently, several new cobalt chromium biodegradable polymer sirolimus-eluting stents have been introduced to clinical practice. This review will describe basic concept and rationale behind the newer cobalt chromium biodegradable polymer sirolimus-eluting stents, systematically present the new clinical experiences with several representative devices.

Importance of CD44 on umbilical cord mesenchymal stem cells for expansion of hematopoietic cells

Human umbilical cord mesenchymal stem cells (hUCMSCs) have important functions on the expansion of hematopoietic stem cells (HSCs) through providing the essential microenvironment for hematopoiesis. In order to test whether CD44 on hUCMSCs could have a key function for the ability of hUCMSCs to expand human HSCs, the soluble anti&mdash;CD44 antibody was added to the co&mdash;cultures of hUCMSCs and cord blood (CB) CD34+ cells, which blocked the ability of hUCMSCs to expand CB CD34+ cells significantly. Long&mdash;term culture initiating cell (LTC&mdash;IC) assay revealed that the ability of multipotent differentiation of CB CD34+ cells co&mdash;cultured with CD44 knockdown hUCMSCs could only retain lasting at most for 5 weeks in vitro. In vivo assay, based on non&mdash;obese diabetic/severe combined immunodeficient disease (NOD/SCID) mice, revealed that the hematopoietic reconstitution potential of CB CD34+ cells co&mdash;cultured with CD44 knockdown hUCMSCs is significantly reduced. The hematopoietic supporting ability of hUCMSCs in vivo and in vitro is reduced upon the knockdown of CD44. CD44 has important functions on the ability of hUCMSCs to expand human HSCs in the cell&mdash; extrinsic control.

[Mechanisms of sorafenib induced NB4 cell apoptosis]

OBJECTIVE

To investigate the effects of sorafenib on human acute promyelocytic leukemia cell NB4 and its mechanism.

METHODS

The human acute promyelocytic leukemia cell NB4 was treated with different concentrations (0, 1.5, 3, 6 and 12 µmol/L) of sorafenib, the proliferation inhibitory rate of NB4 cells was assayed by MTT, the apoptosis of NB4 was determined with flow-cytomatry after treatment; after extraction of total protein, the Western blot was performed to determine the expressions of apoptosis-relatived molecules Caspase-3, Caspase-8 and MCL-1. The mRNA expressions of Caspase-3, Caspase-8 and MCL-1 were determined by RT-PCR.

RESULTS

As compared with the control group, the proliferation of NB4 significantly decreased after treatment with different concentrations of sorafenib. The sorafenib significantly induced the apopotosis of NB4 cells in time- and dose-dependent manners. Furthermore, sorafenib treatment resulted in the obvious increase of the Caspase-3 and Caspase-8 protein and mRNA expressions, and down-regulated the MCL-1 protein and mRNA expressions in NB4 cells.

CONCLUSION

Sorafenib can inhibit proliferation and induce apopotosis of human acute promyelocytic leukemia cell NB4 through the expression of Caspase-3 and Caspase-8, and down-regulation of the expression of MCL-1.

Feasibility of a novel abluminal groove-filled biodegradable polymer sirolimus-eluting stent in patients with complex anatomical and clinical scenarios

AIM

We aimed to investigate the feasibility, initial safety and efficacy of coronary intervention using FIREHAWK®, a novel abluminal groove-filled biodegradable polymer sirolimus-eluting stent (SES), in patients with complex anatomical and clinical scenarios.

METHODS

A total of 57 patients (79 lesions) with complex anatomical and clinical scenarios implanted with the FIREHAWK® SES between March and November 2014 were studied. The primary endpoint was target lesion failure (TLF), a composite endpoint of cardiac death, target vessel-myocardial infarction (TV-MI), and ischemia-driven target lesion revascularization (iTLR). Optical coherence tomography and intravascular ultrasound was performed according to the discretion of operators.

RESULTS

28.1% of patients presented acute myocardial infarction and all patients had at least one of the following anatomical and locational complexity: multi-vessel disease (64.9%), left main disease (24.6%), chronic total occlusion (17.5%), bifurcation (56.1%), and heavily calcified lesions (10.5%). One patients experienced coronary perforation during the procedure and resolved without any additional treatment. Device success was 100%, clinical success was 100%. There was 1 (1.8%) TLF occurred at follow-up of 150 ± 65 days. One patients had non-iTLR. Out of 2 non-Q-wave MI, 1 patient experienced TV-MI, but no death and stent thrombosis were reported. OCT and IVUS imaging showed a high rate of covered struts and low neointimal hyperplasia at follow-up.

CONCLUSION

The study showed the feasibility, initial safety and efficacy of coronary intervention using FIREHAWK® SES for treating patients with complex anatomical and clinical scenarios. The performance of the FIREHAWK® SES in complex patients justifies the conduct of a large, randomized trial.

Inhibitory effects of indirubin derivative PHII-7 on invasion and migration in metastatic cancer

PHII-7, a derivative of indirubin, showed significant anti-cancer activities in vivo and in vitro. We asked whether treating human metastatic cancers and multidrug resistant cancer with PHII-7 would inhibit their invasion and migration. Cell growth was tested by MTT assay and colony formation assay. Apoptosis was examined by flow cytometry. Transwell-based assay and wound healing assay were used to examine cell invasion and migration. Real-time PCR assay and western blot assay were performed to test gene expression on mRNA and protein level, respectively. Firstly, we confirmed that MCF-7/ADR cells showed more invasive and migratory properties compared with MCF-7 cells which were associated with several EMT markers, such as E-cadherin, Slug and vimentin. Secondly, we found that slightly toxic doses of PHII-7 decreased the number of cells that invaded a model epithelial basement membrane and that migrated by switching the molecular signature of the cells from mesenchymal to epithelial. And PHII-7 significantly regulated expression of several epithelial-mesenchymal transition (EMT)-related genes, including E-cadherin, Slug, β-catenin and vimentin. Thirdly, compared with control, PHII-7 inhibited cell proliferation in a time- and dose-dependent manner. Higher doses of PHII-7 also induced apoptosis through activating PARP, caspase-9 and caspase-3. PHII-7 significantly inhibited invasion and migration in both metastatic cancers and multidrug resistant cancer. Our results may provide several data for future application of PHII-7 on drug design and patients treatment.

KEYWORDS

PHII-7, invasion, migration, multidrug resistance, epithelial-mesenchymal transition.

Multidrug resistance gene and its relationship to ulcerative colitis and immune status of ulcerative colitis

We examined the relationship among the multidrug resistance (MDR1) gene product P-glycoprotein (P-gp), ulcerative colitis, and immune status under ulcerative colitis. MDR1 P-gp expression and interleukin-8 levels in ulcerative colitis were determined using immunohistochemistry and a double-antibody sandwich avidin-biotin complex-enzyme-linked immunosorbent assay, respectively. Nitric oxide content and nitric oxide synthase activity in the colonic mucosa were determined using a colorimetric method; CD4(+) and CD25(+) T cell subset percentages in the peripheral blood were determined by flow cytometry. The positive expression rate of P-gp in patients with ulcerative colitis (17.4%) was significantly lower than that in the control group (31.4%). The expression rate decreased to 10.1, 9.2, and 8.3% after 12, 18, and 24 months of treatment, respectively, which were significantly lower than the expression rate before treatment (17.4%). P-gp expression levels during the remission phase and active phase of ulcerative colitis were 15.2 and 17.1%, respectively, which were significantly lower than that in normal controls (31.4%). Compared with P-gp-negative patients, nitric oxide content, nitric oxide synthase activity, and interleukin-8 levels were significantly higher in P-gp-positive patients with moderately active, severely active, early onset, chronic relapsing, chronic persistent, and acute fulminant ulcerative colitis. CD4(+) and CD25(+) T cell subsets were significantly lower in the peripheral blood of patients with severely active and acute fulminant ulcerative colitis than in control subjects. Expression of the multidrug resistance gene and its product P-gp was observed in normal colon tissues and may be closely related to ulcerative colitis.

HDAC6: physiological function and its selective inhibitors for cancer treatment

Acetylation and deacetylation of histones are important in regulating gene expression and play a key role in modification of gene transcription. Specific HDACs isoforms can be regarded as a target for cancer therapy avoiding side-effects, HDAC6 with a unique physiological function and structure has become a hot issue recently. The unique isoform HDAC6 is involved in tumorigenesis, development and metastasis through tubulin, HSP90, invasin and ubiquitin-protein. Here we review the structure elements, biological function, and recent selective inhibitors of HDAC6, and study the structure-activity and structure-selectivity relationship.

Valley-dependent spin polarization in bulk MoS2 with broken inversion symmetry

The valley degree of freedom of electrons is attracting growing interest as a carrier of information in various materials, including graphene, diamond and monolayer transition-metal dichalcogenides. The monolayer transition-metal dichalcogenides are semiconducting and are unique due to the coupling between the spin and valley degrees of freedom originating from the relativistic spin-orbit interaction. Here, we report the direct observation of valley-dependent out-of-plane spin polarization in an archetypal transition-metal dichalcogenide--MoS2--using spin- and angle-resolved photoemission spectroscopy. The result is in fair agreement with a first-principles theoretical prediction. This was made possible by choosing a 3R polytype crystal, which has a non-centrosymmetric structure, rather than the conventional centrosymmetric 2H form. We also confirm robust valley polarization in the 3R form by means of circularly polarized photoluminescence spectroscopy. Non-centrosymmetric transition-metal dichalcogenide crystals may provide a firm basis for the development of magnetic and electric manipulation of spin/valley degrees of freedom.

Angled cavity photonic crystal laser diodes with tilted sidewalls for improving far-field patterns

Angled laser diodes based on the longitudinal photonic band crystal (PBC) waveguide are first proposed and fabricated at a wavelength of 905 nm. Tilted sidewalls are utilized to reflect the light downward, thus enlarging the transverse mode size. In the experiment, continuous wave (CW) output power of 630  mW/facet is achieved, and stable and narrow divergence angles are obtained in the fast and slow axes, simultaneously. The transverse angle is reduced by 44% compared with that of the conventional broad area (BA) laser based on the same wafer, and the lateral angle is only 1.65° with on-axis main-lobe emission. This device shows a promising future for laser emission with ultra-narrow divergence and easy fabrication.

A generic plant RNA isolation method suitable for RNA-Seq and suppression subtractive hybridization

A recently developed revolutionary approach to transcriptomics, RNA-Seq, and suppression subtractive hybridization are powerful tools for gene expression research. However, currently, the difficulty of isolating high-quality RNAs from plant tissues bearing abundant complex polysaccharides, polyphenolics, and secondary metabolites is a serious problem that not only limits the application of these technologies but also hinders studies dealing with RNA in general. We have developed a consistent protocol to prepare highly intact and pure RNAs from tissues of a variety of field-grown plant species, with high yields, in 2 to 3 h. Additionally, this method can be readily applied to mammalian, yeast, and bacterial cells.

Relapse of hyperthyroidism after hemithyroidectomy in concurrent medullary thyroid cancer and Graves' disease

We present a rare case of concurrent medullary thyroid cancer (MTC) and relapse of Graves' disease (GD). A 26-year-old Chinese female suffered from GD for 1 year. Physical examination demonstrated mildly diffuse goiter with a palpable 1.0 cm nodule in the right thyroid lobe and exophthalmos. Before hemithyroidectomy, calcitonin was elevated and thyroglobulin was normal. After surgery, histopathological findings proved coexistence of MTC and GD. 16 months later, GD relapsed and radioactive iodine 131 therapy was given. Meanwhile, postoperative monitoring showed well controlled calcitonin and carcinoembryonic antigen. Our lesson demonstrates although concomitant of MTC and GD is very rare, yet after hemithyroidectomy for the single nodular MTC lesion, remnant thyroid lobe could be the source of GD relapse very soon. More importantly, the relapse of GD and the following radioiodine therapy and radiation exposure could have been prevented if a better therapy plan of total thyroidectomy was adopted in the first place, instead of hemithyroidectomy (Tab. 1, Fig. 2, Ref. 11).

Expression of cytochrome P450 1A1/2 and 3A4 in liver tissues of hepatocellular carcinoma cases and controls from Taiwan and their relationship to hepatitis B virus and aflatoxin B1-and 4-aminobiphenyl-DNA adducts

Cytochrome P450 enzymes play a major role in the metabolism of several of the chemical carcinogens involved in the development of hepatocellular carcinoma (HCC). To investigate by immunohistochemistry interindividual differences in these enzymes, polyclonal antisera and immunoperoxidase staining were used to detect the expression of CYP1A1/2 and 3A4 in 37 surgical control tissues and 105 tumour and adjacent nontumour tissues of HCC cases from Taiwan. There was variability in the expression and staining pattern for both CYP1A1/2 and 3A4 in all tissue types. In tissues from controls, there was no correlation between P450 expression and smoking history or hepatitis B virus antigen status. Since these samples had been previously analysed for the DNA adducts of aflatoxin B1 (AFB1), a dietary mould contaminant, and 4-aminobiphenyl (4-ABP), a component of cigarette smoke, we also investigated the relationship between P450 levels and DNA adducts. 4-ABP-DNA adducts were higher in tissues with elevated levels of CYP1A1/2 (p = 0.02). Overall there was no relationship between CYP1A1/2 or CYP3A4 and AFB1-DNA adducts in control tissues. Staining intensity for CYP1A1/2 and 3A4 followed the order: tumour tissues < control tissues < adjacent non-tumour tissues. CYP1A1/2 levels tended to be lower in tumour and adjacent non-tumour tissues than for CYP3A4. In HCC cases, 4-ABP-DNA adducts were higher in subjects with higher levels of CYP1A1/2, stratified by tissue type, but these differences were not significant. For CYP3A4, in contrast to control tissues, there was a significant association with AFB1-DNA adducts in tumour and adjacent non-tumour tissue of HCC cases. These results suggest that one factor influencing carcinogen-DNA adducts is levels of specific P450 enzymes. However, adduct formation in vivo is a complex processes dependent upon numerous genetic and environmental factors.

Formation of a stable p-n junction in a liquid-gated MoS2 ambipolar transistor

Molybdenum disulfide (MoS2) has gained attention because of its high mobility and circular dichroism. As a crucial step to merge these advantages into a single device, we present a method that electronically controls and locates p-n junctions in liquid-gated ambipolar MoS2 transistors. A bias-independent p-n junction was formed, and it displayed rectifying I-V characteristics. This p-n diode could perform a crucial role in the development of optoelectronic valleytronic devices.

Optimal combination of radiotherapy and endocrine drugs in breast cancer treatment

PURPOSE

Breast cancer is the most common cancer in women. Radiotherapy is considered a standard treatment option after surgery and adjuvant endocrine therapy is also universally used. Tamoxifen and letrozole are the current first-line endocrine therapy drugs. However, information has been scarce about how best to sequence these therapies to maximize their effectiveness and keep toxic effects to a minimum. In this study, we observed the effect of different sequence combination of radiotherapy and endocrine drugs, tamoxifen or letrozole, to get the best treatment sequence.

MATERIALS AND METHODS

The combination effect of radiotherapy and tamoxifen was observed on breast tumour cell line MCF-7, radiotherapy and letrozole on aromatase-expressing breast tumour cell line MCF-7CA. Irradiation was performed with 6Gy, except for doses ranging from 0 to 8Gy for clone formation assay. Tamoxifen or letrozole was added before or after irradiation, respectively. Radiosensitivity was evaluated by clonogenic assay, cell viability by 3-(4,-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay. To explore the potential mechanism, cell apoptosis was determined by DNA-binding dye 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) assay, the change of Bcl-2 and Bax expression was by western blot.

RESULTS

Although no significant statistical difference was observed between different sequence, tamoxifen and letrozole both increased radiosensitivity. Furthermore, the above inhibitory effect was related with apoptosis signaling pathway, especially Bcl-2 and Bax.

CONCLUSION

Taken together, these results suggested that endocrine drugs, such as tamoxifen and letrozole, have potential application with radiotherapy.

First Report on the Occurrence of A2 Mating Type of the Cucurbit Downy Mildew Agent Pseudoperonospora cubensis in China

Pseudoperonospora cubensis is a foliar pathogen of cucurbits. In cucumber, it produces chlorotic, angular lesions with dark sporangia on their under-surface. The distribution of pathotypes and mating types of P. cubensis were investigated in seven provinces in China. Twenty-nine isolates were obtained from Guangdong, Anhui, Hubei, Sichuan, Shandong, Beijing, and Harbin, one to six isolates from each province. They were collected from cucumber during summer 2011, except those from Harbin, which were collected from cucumber in summer 2012. Isolates were tested for pathogenicity and mating type. Pathogenicity was tested by inoculation of detached leaves of: cucumber (Cucumis sativum cvs. Bet-Alpha, SMR18), melon (Cucumis melo reticulatus cv. Ananas-Yokneam), pumpkin (Cucurbita maxima cv. Tripoli), squash (Cucurbita pepo, cv. Beruti), butternut gourd (Cucurbita moschata cv. Waltham), watermelon (Citrullus lanatus, cv. Malali), and sponge gourd (Luffa cylindrica, cultivar unknown). Mating type was determined by oospore production in melon leaf discs inoculated with mixed sporangia of a test isolate and A1 or A2 tester isolates, as recently described (2). The results showed that 22 isolates belonged to pathotype 3, sporulating on cucumber and melon; five isolates belonged to pathotype 6, sporulating on cucumber, melon, pumpkin, squash, and butternut gourd; one isolate belonged to pathotype 5, sporulating on the above five species and watermelon (1), and one isolate was capable of sporulating on the mentioned five species and sponge gourd, herein called pathotype 7. Of the 29 isolates tested, 22 belonged to the A1 mating type, six to the A2 mating type, and one did not produce oospores with either testers. Of the six A2 isolates, two originated from Sichuan, one from Beijing, and three from Harbin. All 22 isolates belonging to pathotype 3 were A1, whereas the other six isolates (four pathotype 6, one pathotype 5, and one pathotype 7) were A2. Crosses made between Chinese isolates belonging to opposite mating types resulted in the formation of abundant oospores in detached melon or cucumber leaves. The results prove that the A2 mating type of P. cubensis occurs in China. This explains the abundant occurrence of oospores of P. cubensis in nature in China (4). The data corroborate with Runge et al. (3), who suggested that the recent changes in the population structure of P. cubensis around the world resulted from the migration of a new genotype of P. cubensis from the Far East to Europe and the U.S.A. In Israel, a new pathotype attacking both Cucumis and Cucurbita appeared in 2002 (1), and A2 mating type first appeared in 2010 (2). References: (1) Y. Cohen et al. Phytoparasitica 31:458, 2003. (2) Y. Cohen and A. E. Rubin. Eur. J. Plant Pathol. 132:577, 2012. (3) F. Runge et al. Eur. J. Plant Pathol. 129:135, 2011. (4) Y. J. Zhang et al. J. Phytopathol. 160:469, 2012.

First Report of Hosta virus X Infecting Hosta Plants in China

Hosta (Hosta spp.) plants showing leaf deformation, puckering, and ink-bleed symptoms were collected in July 2012 from a park at Dongcheng district, Beijing, China. Three out of six samples tested positive for Hosta virus X (HVX) by immunostrip and double-antibody sandwich (DAS)-ELISA with HVX-specific serological reagents from Agdia Inc. (Elkhart, IN, USA). Filamentous viral particles were trapped and observed from the infected hosta leaf sap by immuno-serological electron microscopy (ISEM) (antibodies from Agdia). To confirm HVX infection, three ELISA-positive samples were analyzed by reverse transcription-PCR assay, using virus-specific primers HVXf (5'-ATCCGTTATCTACAGGGGACCAG-3') and HVXr (5'-TAAGTTAGTGGAACGGTTAGCCCGAT-3') that amplified a 1,067-bp fragment including the coat protein (CP) coding region. The CP nucleotide sequence comparisons showed 99% to 100% homology among the three isolates named HVXBJ4, HVXBJ5, and HVXBJ6 (GenBank Accession No. JX535292, JX535293, and JX535294) and with the HVX sequences previously reported in GenBank. HVX has been reported from the United States, Korea, the Netherlands, Poland, France, the Czech Republic, and New Zealand (1,2). To our knowledge, this is the first report of HVX infecting hosta plants in China. As an ornamental and medicinal plant, hosta has been cultivated in China for more than 2,000 years. The presence of HVX in Beijing is a potential threat to the landscape in the city. HVX can be spread by vegetative propagation material or mechanical contact (3). Hence, to cultivate HVX-free hosta and restrict the movement of HVX-infected hosta is vitally important in the future. HVX has become economically important in the world more recently. Globalization of trade in hosta plants has increased the risk of movement of HVX. The national plant protection organization should establish effective quarantine strategy and the growers take proper planting measures to avoid further spreading of this virus. References: (1) S. Currier et al. Plant Dis. 80:1040, 1996. (2) M. H. Park et al. Arch. Virol. 148:2039, 2003. (3) K. H. Ryu et al. Acta Hortic. 722:91, 2006.

Association between CASP-8 gene polymorphisms and cancer risk in some Asian population based on a HuGE review and meta-analysis

Genetic variation in the CASP-8 gene reportedly can increase cancer susceptibility by regulating tumor cell proliferation and apoptosis. Several studies have investigated this possibility; however, the conclusions remain controversial. We made a Human Genome Epidemiology (HuGE) review and did a meta-analysis to explore the association between CASP-8 gene polymorphisms and cancer risk in Asian populations. Based on the inclusion criteria, 12 case-control studies comprising 7720 cancer cases and 9404 healthy controls were retrieved. Meta-analysis results showed that the rs3834129*del allele/carrier were associated with decreased risk of cancer in Asian populations [del allele: odd ratio (OR) = 0.79, 95% confidence interval (95%CI) = 0.75-0.83, P < 0.001; del carrier: OR = 0.77, 95%CI = 0.72-0.82, P < 0.001]. Subgroup analysis showed that the rs3834129*del allele/carrier are protective factors for cancer risk in Chinese populations (del allele: OR = 0.77, 95%CI = 0.73-0.81, P < 0.001; del carrier: OR = 0.75, 95%CI = 0.70-0.80, P < 0.001), but not in Indian and Korean populations. Furthermore, the rs6704688*T allele/carrier, rs3769827*C allele/carrier, rs3769825*C allele/carrier were associated with decreased risk of cancer in Asian populations (all P < 0.05). While the rs7608692*A allele was associated with increased risk of cancer risk in Asian populations (OR = 1.35, 95%CI = 1.02-1.78, P = 0.03). There was also no significant association between rs3769818, rs13030042, rs13030042, rs1045494, rs1045494, rs2823, or rs113686495, and cancer risk in Asian populations (all P > 0.05). This meta-analysis suggests that the rs3834129*del allele/ carrier, rs6704688*T allele/carrier, rs3769827*C allele/carrier, and rs3769825*C allele/carrier might be protective factors for cancer risk in Asian populations, while the rs7608692*A allele might be a risk factor for cancer risk in Asian populations.

Efficient isolation of high-quality RNA from lotus Nelumbo nucifera ssp nucifera tissues

Nelumbo nucifera is widely used as food, as an ornamental, in medicine, and as packing material; it is also reported to have anti-HIV effects and antioxidant capacity. We sought an improved method for extracting high-quality total RNA from different tissues of N. nucifera. Four methods for RNA extraction were assessed for their ability to recover high-quality RNA applicable for evaluation of polyphenol oxidase (PPO) gene expression profiles. The recovery and quality of the RNA obtained from five different tissues by the best CTAB-LiCl method were evaluated through UV light absorbance. Both A(260)/A(280) and A(260)/A(230) absorbance ratios were more than 2.0; the yield ranged from 59.87 to 163.75 μg/g fresh weight. The brightness of the 28S band was approximately twice that of 18S; the latter was also considered as high-quality RNA. The PPO gene fragment (606 bp) was successfully amplified by RT-PCR, demonstrating the integrity of the isolated RNA. The relative expression levels of the PPO gene based on RT-PCR in five tissues of lotus were: rhizome buds (2.66), young leaves (2.42), fresh cut rhizome (2.02), petals (1.80), and petiole (1.65), using housekeeping gene β-actin as an internal control. We concluded that the total RNA isolated by this protocol is of sufficient quality for molecular applications.