[Spatial distribution characteristics analysis on multidrug-resistant tuberculosis cases in Zhejiang province, 2010-2012]

OBJECTIVE

To analyze the spatial distribution characteristics of multidrug-resistant (MDR) tuberculosis (TB) cases in Zhejiang province in 2010-2012.

METHODS

Data on MDR-TB cases in Zhejiang province were collected and linked to the digital map at the county and district levels. ArcGIS 10.0 software was used for spatial analysis.

RESULTS

RESULTS from the spatial autocorrelation analysis showed that spatial aggregation appeared in MDR-TB distribution during 2010-2012 while local Moran's I spatial autocorrelation analysis identified several "high incidence regions" (Wuxing, Deqing, Yuhang, Gongshu, Jianggan, Xiaoshan, Yuecheng, Shaoxing Shengzhou, Changshan, Kecheng), and "low incidence region" (Haishu). Through Getis-Ord General G spatial autocorrelation analysis, 18 "positive hotspots" (Wuxing, Nanxun, Deqing, Yuhang, Shangcheng, Xiacheng, Gongshu, Jianggan, Binjiang Xiaoshan Xihu, Haining, Yuecheng, Shaoxing, Zhuji, Shengzhou, Kecheng and Suichang) and 11 "negative hotspots" (Nanhu, Haiyan, Cixi, Dinghai, Zhenhai, Jiangbei, Jiangdong, Beilun, Yinzhou, Fenghua, and Yueqing) were identified.

CONCLUSIONS

Spatial analysis on MDR-TB incidence implied the spatial aggregation in Zhejiang province. Data showed that the hotspots with high population density and human movement were under progressive expansion.

[Body mass index and the risk of lung cancer incidence in smokers: a prospective cohort study]

OBJECTIVE

To investigate the effect of baseline body mass index (BMI) on the risk of lung cancer incidence in male smokers.

METHODS

All the male employees and retirees of the Kailuan Group were recruited in the Chinese Kailuan Male Cohort Study, and they had been experienced routine physical examinations every two years since May, 2006. Up to 31st December 2011, a total of 3 rounds physical examinations had been completed. A total of 42 718 male smokers candidates from the Chinese Kailuan Male Cohort Study were enrolled in the present study. The date of entering this study was defined as that of taking first check-up, and the date of end-of-observation was defined as that of cancer diagnosis, death or end of follow-up (31 December 2011). Information on demographics, lifestyle such as smoking, alcohol consumption, anthropometries such as height and weight, as well as the information of newly-diagnosed cancer cases, were collected at the baseline investigation. Multivariable Cox proportional hazards regression models were used to investigate the association between levels of the baseline BMI and risk of lung cancer.

RESULTS

Of the 42 718 male smokers, there were 181 998.09 person-years of follow-up, taking 4.26 years of average follow-up period. During follow-up, 234 new lung cancer cases were identified among the 42 718 male smokers and the crude incidence density was 128.57/100 000. After the factors adjustment for age, education level, alcohol consumption, physical activity, work environment and cumulative smoking levels (pack-years), compared with subjects of normal BMI group, hazard ratio and 95% confidence intervals of lung cancer for subjects of underweight, overweight, and obesity were 1.63 (0.79-3.37), 0.79 (0.57-1.09) and 0.50 (0.27-0.91), respectively. After the facotors adjustment for age, education level, alcohol consumption, physical activity, work environment and cumulative smoking levels (pack-years), compared with subjects of normal BMI, hazard ratio and 95% confidence intervals of lung cancer for subjects of obesity among subjects who aged 50 years or above, smoked more than 20 pack-years, and exercised less than 4 times per week were 0.33 (0.15-0.71), 0.27 (0.10-0.75), and 0.44 (0.20-0.96), respectively. Obesity subjects who worked above the well had decreased risk of lung cancer (HR=0.38, 95% CI: 0.15-0.96) compared with normal BMI ones who worked above the well.

CONCLUSION

BMI was negatively correlated with the risk of lung cancer in male smokers. As for male smokers, one of the most effective approaches to prevent and control the lung cancer has been shown to quit smoking and keep fit.

[Long term result of arytenoidectomy with CO₂ laser for dyspnoea in iatrogenic bilateral vocal fold paralysis patients]

Objective:To investigate the optimal time of tracheotomy/arytenoidectomy and the improvement of dyspnoea, dysphonia and dysphagia after arytenoidectomy with CO₂ laser in iatrogenic bilateral vocal folds paralysis patients. Method:Thirty patients [29 females, 56 (49-60) years, one male, 49 years] with bilateral vocal cords paralysis resulted from neck surgery were retrospectively analyzed by case archived information and following-up questionnaire. The data included patients' dysponea time, degree and duration from tracheotomy/arytenoidectomy to neck surgery. Twenty sixty patients required unilateral partial/total arytenoidectomy. The results of treatment were evaluated by questionnaire including dyspnoea, dysphonia and dysphagia. Result:All patients whose bilateral vocal paralysis were resulted from thyroid gland surgery. Dysponea occurred immediately after thyroidectomy surgery in 14 cases (46.7%), and 2 years later after thyroidectomy in 13 cases (43.3%), 8 years later in 3 cases (10.0%). There was one (3.3%) patient without tracheotomy. The duration of tracheotomy/arytenoidectomy to neck surgery was significantly correlated with duration of tracheotomy/arytenoidectomy to dyspnoea appearance (r=0.879, P<0.05), not correlated with duration of thyroid surgery to dyspnoea appearance. There is significantly negative correlation between degree of dyspnoea and duration of tracheotomy/arytenoidectomy to neck surgery (r=0.452, P<0.05). Twenty six patients appeared dyspnoea and underwent CO₂ laser arytenoidectomy after thyoidectomy 0.5-23 years. Five patients did unilateral total arytenoidectomy and 21 patients did unilateral partial arytenoidectomy. After 12-96 months following up, dyspnoea improved in 24 patients, no improved in 2 patients. Dysphonia improved and remained in 17 patients, being worse mildly in 8 patients and obviously in one patient. Dysphagia improved and remained in 24 patients, being worse in 2 patients. There was no difference between total and partial arytenoidectomy in dyspnoea, dysphonia and dysphagia. Conclusion:The morbidity of dyspnoea was correlated with time after neck surgery. It was rarely necessary to take tracheotomy immediately in bilateral vocal fords paralysis patients after neck surgery. The severer degree of dyspnoea led to shorter duration between neck surgery and tracheotomy/arytenoidectomy. There was obvious improvement after arytenoidectomy in dyspnoea, no significant change in dysphonia and dysphagia. The effect of total arytenoidectomy on bilateral vocal paralysis was similar to partial arytenoidectomy.

[Influencing factors of orthostatism brachial-ankle pulse wave velocity and ankle brachial index in the elderly]

OBJECTIVE

To investigate the distribution and influencing factors of orthostatism brachial-ankle pulse wave velocity(baPWV) and ankle brachial index(ABI) in the elderly.

METHODS

Participants were selected with random sampling from ≥60 years old retired workers, who underwent 2010 to 2011 health check-up in the Tangshan Kailuan Hospital, Kailuan Linxi Hospital, Kailuan Zhaogezhuang Hospital. Multivariate linear regression analysis was used to analyze the influencing factors of orthostatism and supine baPWV and ABI in the elderly.

RESULTS

(1) A total of 2 464 participants were included, and 1 601 participants (1 065 males(66.5%) and (67.5±6.1) years old) with integral data were analyzed. Orthostatism baPWV was (3 885.4±1 503.5)cm/s and Supine baPWV was (1 761.2±371.4)cm/s.Orthostatism ABI was 1.54±0.21 and supine ABI was 1.10±0.12. Orthostatism baPWV increased with increasing age, while orthostatism ABI decreased with aging(trend test, both P<0.01)in <65, 65-69, 70-74, and ≥75 years old participants.(2) Multiple linear regression analysis showed that the age(β=0.19, P<0.01), lower limbs orthostatism systolic blood pressure(β=0.18, P<0.01), lower limbs supine systolic blood pressure (β=0.14, P<0.01), orthostatism heart rate (β=0.30, P<0.01), supine heart rate (β=0.23, P<0.01), body mass index (β=-0.18, P<0.01) were associated with orthostatism baPWV, and female(β=-0.055, P=0.01), upper limb orthostatism systolic blood pressure (β=-0.834, P<0.01), lower limbs orthostatism systolic blood pressure (β=0.708, P<0.01), lower limbs supine systolic blood pressure (β=0.099, P<0.01) and fasting blood glucose(β=-0.085, P<0.01) were associated with orthostatism ABI.

CONCLUSIONS

Orthostatism baPWV and ABI were significantly higher than those of supine's. Age, lower limbs orthostatism and supine systolic blood pressure, orthostatism and supine heart rate, body mass index were associated with orthostatism baPWV. Female, upper limb orthostatism systolic blood pressure, lower limbs orthostatism, supine systolic blood pressure and fasting blood glucose were associated with orthostatism ABI in the elderly.

Loading-rate-independent delay of catastrophic avalanches in a bulk metallic glass

The plastic flow of bulk metallic glasses (BMGs) is characterized by intermittent bursts of avalanches, and this trend results in disastrous failures of BMGs. In the present work, a double-side-notched BMG specimen is designed, which exhibits chaotic plastic flows consisting of several catastrophic avalanches under the applied loading. The disastrous shear avalanches have, then, been delayed by forming a stable plastic-flow stage in the specimens with tailored distances between the bottoms of the notches, where the distribution of a complex stress field is acquired. Differing from the conventional compressive testing results, such a delaying process is independent of loading rate. The statistical analysis shows that in the specimens with delayed catastrophic failures, the plastic flow can evolve to a critical dynamics, making the catastrophic failure more predictable than the ones with chaotic plastic flows. The findings are of significance in understanding the plastic-flow mechanisms in BMGs and controlling the avalanches in relating solids.

The mediating role of Internet addiction in depression, social anxiety, and psychosocial well-being among adolescents in six Asian countries: a structural equation modelling approach

OBJECTIVES

This study examines the associations of Internet addiction with social anxiety, depression, and psychosocial well-being among Asian adolescents. A self-medication model conceptualizing Internet addiction as a mediating role in relating depression and social anxiety to negative psychosocial well-being was tested.

STUDY DESIGN

A cross-sectional survey.

METHODS

In the Asian Adolescent Risk Behavior Survey (AARBS), 5366 adolescents aged 12-18 years from six Asian countries (China, Hong Kong, Japan, South Korea, Malaysia, and Philippines) completed a questionnaire with items of the Internet Addiction Test (IAT), Social Anxiety Scale for Adolescents (SAS-A), Center for Epidemiological Studies Depression Scale (CESD), Self-Rated Health of the Nation Outcome Scales for Children and Adolescents (HoNOSCA-SR) in the 2012-2013 school year. Structural equation modelling was used to examine the mediating role of Internet addiction in depression, social anxiety, and subjective psychosocial well-being.

RESULTS

Significant differences on the scores of IAT, SAS-A, CESD, and HoNOSCA-SR across the six countries were found. The proposed self-medication model of Internet addiction received satisfactory goodness-of-fit with data of all countries. After the path from social anxiety to Internet addiction had been discarded in the revised model, there was a significant improvement of the goodness-of-fit in the models for Japan, South Korea, and the Philippines.

CONCLUSIONS

Depression and social anxiety reciprocally influenced, whereas depression associated with poorer psychosocial well-being directly and indirectly through Internet addiction in all six countries. Internet addiction mediated the association between social anxiety and poor psychosocial well-being in China, Hong Kong, and Malaysia.

Development of biodegradable Zn-1X binary alloys with nutrient alloying elements Mg, Ca and Sr

Biodegradable metals have attracted considerable attentions in recent years. Besides the early launched biodegradable Mg and Fe metals, Zn, an essential element with osteogenic potential of human body, is regarded and studied as a new kind of potential biodegradable metal quite recently. Unfortunately, pure Zn is soft, brittle and has low mechanical strength in the practice, which needs further improvement in order to meet the clinical requirements. On the other hand, the widely used industrial Zn-based alloys usually contain biotoxic elements (for instance, ZA series contain toxic Al elements up to 40 wt.%), which subsequently bring up biosafety concerns. In the present work, novel Zn-1X binary alloys, with the addition of nutrition elements Mg, Ca and Sr were designed (cast, rolled and extruded Zn-1Mg, Zn-1Ca and Zn-1Sr). Their microstructure and mechanical property, degradation and in vitro and in vivo biocompatibility were studied systematically. The results demonstrated that the Zn-1X (Mg, Ca and Sr) alloys have profoundly modified the mechanical properties and biocompatibility of pure Zn. Zn-1X (Mg, Ca and Sr) alloys showed great potential for use in a new generation of biodegradable implants, opening up a new avenue in the area of biodegradable metals.

Myeloid-Derived Suppressor Cells as an Immune Parameter in Patients with Concurrent Sunitinib and Stereotactic Body Radiotherapy

PURPOSE

The clinical effects of sunitinib on human myeloid-derived suppressor cell (MDSC) subsets and correlation of the T-cell-mediated immune responses and clinical outcomes in patients with oligometastases treated by stereotactic body radiotherapy (SBRT) have been evaluated.

EXPERIMENTAL DESIGN

The numbers of granulocytic and monocytic MDSC subsets, effector T cells, and regulatory T cells in the peripheral blood were evaluated pre- and post-sunitinib treatment and concurrent with SBRT. Correlations between MDSC, Treg, and T-cell responses and clinical outcomes were analyzed.

RESULTS

Patients with oligometastases of various cancer types had elevated granulocytic MDSC and certain subsets of monocytic MDSC population. Sunitinib treatment resulted in a significant reduction in monocytic MDSC, phosphorylated STAT3, and arginase levels in monocytic MDSC (CD33(+)CD14(+)CD16(+)), and an increase in T-cell proliferative activity in cancer patients. Interestingly, the effects of sunitinib on reducing the accumulation and immune-suppressive function of MDSC were significantly correlated with Treg reduction, in responders but not in nonresponding patients. SBRT synergized the therapeutic effects of sunitinib, especially as related to decreased numbers of monocytic MDSC, Treg, and B cells, and augmented Tbet expression in primary CD4 and CD8 T cells. These effects were not observed in patients receiving radiation therapy alone. Most interestingly, the responders, defined by sunitinib-mediated reduction in CD33(+)CD11b(+) myeloid cell populations, tend to exhibit improved progression-free survival and cause-specific survival.

CONCLUSIONS

Sunitinib treatment increased the efficacy of SBRT in patients with oligometastases by reversing MDSC and Treg-mediated immune suppression and may enhance cancer immune therapy to prevent tumor recurrence post-SBRT.

YM155 down-regulates survivin and XIAP, modulates autophagy and induces autophagy-dependent DNA damage in breast cancer cells

BACKGROUND AND PURPOSE

The aim of this study was to determine the potency and molecular mechanism of action of YM155, a first-in-class survivin inhibitor that is currently under phase I/II clinical investigations, in various drug-resistant breast cancers including the oestrogen receptor positive (ER(+) ) tamoxifen-resistant breast cancer and the caspase-3-deficient breast cancer.

EXPERIMENTAL APPROACH

The potency of YM155 in SK-BR-3, MDA-MB-231, MCF7 and its tamoxifen-resistant sublines, TamR6, TamR7, TamR8, TamC3 and TamC6, were determined by MTT assay. Western blot analysis, flow cytometric analysis, reverse transcription-PCR, fluorescent microscopy and comet assay were used to determine the molecular mechanism of action of YM155 in different breast cancer cell lines.

KEY RESULTS

YM155 was equally potent towards the parental ER(+) /caspase-3-deficient MCF7 breast cancer cells and its tamoxifen-resistant sublines in vitro. The ER(-) /HER2(+) SK-BR-3 breast cancer cells and the triple-negative/caspase-3-expressing metastatic aggressive MDA-MB-231 breast cancer cells were also sensitive to YM155 with IC50 values in the low nanomolar range. Targeting survivin by YM155 modulated autophagy, induced autophagy-dependent caspase-7 activation and autophagy-dependent DNA damage in breast cancer cells. Interestingly, YM155 also induced XIAP degradation and the degradation of XIAP might play an important role in YM155-induced autophagy in breast cancer cells.

CONCLUSIONS AND IMPLICATIONS

YM155 is a potent survivin inhibitor that has potential for the management of various breast cancer subtypes regardless of the expression of ER, HER2 and caspase-3. Importantly, this study provides new insights into YM155's molecular mechanism of action and therapeutic potential in the treatment of tamoxifen-resistant breast cancer.

Immune cells: more than simple carriers for systemic delivery of oncolytic viruses

Oncolytic virotherapy on its own has numerous drawbacks, including an inability of the virus to actively target tumor cells and systemic toxicities at the high doses necessary to effectively treat tumors. Addition of immune cell-based carriers of oncolytic viruses holds promise as a technique in which oncolytic virus can be delivered directly to tumors in smaller and less toxic doses. Interestingly, the cell carriers themselves have also demonstrated antitumor effects, which can be augmented further by tailoring the appropriate oncolytic virus to the appropriate cell type. This review discusses the multiple factors that go into devising an effective, cell-based delivery system for oncolytic viruses.

Immunizations with hepatitis B viral antigens and a TLR7/8 agonist adjuvant induce antigen-specific immune responses in HBV-transgenic mice

Background

The capacity of toll-like receptor (TLR) 7/8 agonist-conjugated hepatitis B virus (HBV) proteins (HBV-Ag) to overcome established hepatitis B surface antigen (HBsAg)-specific immune tolerance was explored.

Methods

A TLR7/8 agonist, CL097, was conjugated with alum-absorbed HBsAg and hepatitis B core antigen (HBcAg), as confirmed by ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF MS). Mice from two independently generated HBV-transgenic (HBV-Tg) colonies, C57BL/6J-TgN (AlblHBV) 44Bri/J mice and C57BL/6-HBV-1.3 genome-eq mice, were immunized with CL097-conjugated HBV-Ag every 2 weeks, four times.

Results

After immunization, 8/11 (72.7%) of the AlblHBV mice and 10/13 (76.9%) of the HBV-1.3 genome-eq mice generated serum detectable antibodies against HBsAg (anti-HBs). HBsAg-specific interferon gamma (IFN-γ)-producing CD4⁺ and CD8⁺ T-cells were detected in splenocytes from these mice. Naїve normal mice receiving splenocytes from the mice immunized with CL097-conjugated HBV-Ag generated immediate recall immune responses, e.g., the mice that received CD4⁺CD25⁺-depleted splenocytes generated anti-HBs on day 3 after HBsAg challenge while those receiving cells from sham-immunized mice did not.

Conclusions

Immunization with CL097-conjugated HBV-Ag reversed immune tolerance in HBV-Tg mice and induced antigen-specific immune responses. TLR7/8 agonists appear to be potent adjuvants for the induction of antigen-specific Th1 responses in an immune tolerant state.

Conduction control at ferroic domain walls via external stimuli

Intriguing functionalities at nano-sized domain walls have recently spawned a new paradigm for developing novel nanoelectronics due to versatile characteristics. In this study, we explore a new scenario to modulate the local conduction of ferroic domain walls. Three controlling parameters, i.e., external electrical field, magnetic field and light, are introduced to the 90° domain walls (90° DWs) of BiFeO₃. Electrical modulation is realized by electrical transport, where the mobility of 90° DWs can be altered by gating voltage. We further use the ferromagnetic/antiferromagnetic coupling to reveal the inherent magnetism at the DWs. With an established magnetic nature, magnetotransport has been conducted to introduce magnetic controlling parameter, where a giant positive magnetoresistance change can be observed up to 200%. In addition, light modulated conduction, a core factor for multifunctional applications, is successfully demonstrated (current enhancement by a factor of 2 with 11 W white lamp). These results offer new insights to discover the tunability of domain wall nanoelectronics.

Circulating chemerin levels are increased in first-degree relatives of type 2 diabetic patients

BACKGROUND

Chemerin is an important risk factor of insulin resistance and metabolic syndrome. The aim of this study was to explore the potential role of chemerin in the early stage of diabetes development.

METHODS

63 control subjects without any family history of diabetes and with normal glucose tolerance (NGT) and 74 healthy, first-degree relatives (FDRs) of type 2 diabetic patients were recruited in the study. All subjects underwent a 75 g oral glucose tolerance (OGTT) test after having fasted overnight. Plasma glucose, insulin, total cholesterol, HDL cholesterol, triglycerides, chemerin, and adiponectin were measured.

RESULTS

FDR subjects had higher BMI, WHR, waist, fasting plasma glucose, fasting insulin, TG, UA, HOMA-IR, LDL-C, and lower HDL- C levels than control subjects (p < 0.05). The FDRs group had significantly lower adiponectin levels while chemerin was higher. Plasma chemerin levels were independently correlated with HOMA-IR, FINS, TG, FPG, and adiponectin level. Multiple stepwise regression analysis showed that HOMA-IR and TG were independent risk factors that influenced circulating chemerin levels.

CONCLUSIONS

These findings showed a significant increase of chemerin levels in FDR subjects which suggested that chemerin may be involved in the development and progression of insulin resistance.

A balance between BCR and inhibitory receptor signaling controls plasma cell differentiation by maintaining optimal Ets1 levels (BA2P.120)

Signaling through the B cell receptor (BCR) can drive B cell activation and contribute to B cell differentiation into antibody-secreting plasma cells. The positive BCR activation signal is counterbalanced by a number of membrane-localized inhibitory receptors that limit B cell activation and plasma cell differentiation. Deficiencies in these negative signaling pathways may cause autoantibody generation and autoimmune disease in both animal models and human patients. We have previously shown that the transcription factor Ets1 can restrain B cell differentiation into plasma cells. Here, we tested the roles of the BCR and inhibitory receptors in controlling the expression of Ets1 in B cells. We found that Ets1 is down regulated in B cells by BCR or TLR signaling through a pathway dependent on PI3 kinase, Btk, IKK2 and JNK. Deficiencies in inhibitory pathways, such as a loss of the tyrosine kinase Lyn, the phosphatase SHP1 or membrane receptors CD22 or Siglec-G, result in enhanced BCR signaling and decreased Ets1 expression. Restoring Ets1 expression in Lyn- or SHP1-deficient B cells inhibits their enhanced plasma cell differentiation. Our findings suggest that the maintenance of Ets1 expression is an important function of the inhibitory Lyn -- CD22/SiglecG -- SHP1 pathway in B cells.

Control of trichloroethylene plume migration using a biobarrier system: a field-scale study

The objective of this field-scale study was to evaluate the effectiveness of controlling trichloroethylene (TCE) plume migration using the polycolloid substrate (PS) biobarrier. The developed PS (containing soybean oil, lactate and surfactants) could release substrate to enhance the TCE dechlorination. In this study, a biobarrier comprising PS injection wells was installed. Injection wells were installed at 5-m intervals, and approximately 15 L of PS was injected into each well. Results show that TCE concentrations in the injection wells dropped from an average of 87 μg/L to below 1 μg/L after 35 days of PS injection. The total organic carbon concentrations in the injection wells increased from an average of 2.1-543 mg/L after 30 days of PS injection. The dissolved oxygen (DO) concentrations and oxidation-reduction potential (ORP) values dropped from an average of 1.6 mg/L to below 0.1 mg/L and from 124 mv to -14 mv after 20 days of injection, respectively. The DO and ORP remained in anaerobic conditions during the remaining 100 days of the operational period. TCE degradation by-products were observed in groundwater samples during the operational period. This reveals that the addition of PS could effectively enhance the reductive dechlorinating of TCE.

Basic fibroblast growth factor upregulates expression of growth hormone gene through extracellular signal-regulated kinase 1/2 in GH4 cells

Basic fibroblast growth factor (bFGF) is reported to not only play multifunctions in pituitary differentiation and tumor formation, stimulating cell differentiation or proliferation, also stimulate pituitary to secret prolactin, growth hormone (GH) and thyroid stimulating hormone, although obvious effect on growth hormone only responded to high-dose bFGF. Since it is well documented that both bFGF and GH correlate closely to tumorigenesis, development and metastasis, so it is necessary to reveal the relationship between the cytokines. In the present report we investigated the effect of bFGF on transcription level of GH gene in GH4 rat pituitary cells as well as the regulatory mechanism with real-time reverse transcription polymerase chain reaction and western blotting. We observed a significant expressional increase of GH gene in GH4 cells stimulated by bFGF, meanwhile phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) was also found in the cells. Further investigation unveiled that PD98059, a specific inhibitor of ERK1/2 signaling pathway markedly impaired the transcriptional increment of GH gene induced by bFGF in the pituitary cells, which indicates that bFGF upregulates GH gene expression through ERK1/2 signaling pathway in GH4 cells. Results may be helpful to elaborate roles of the two cytokines on tumor (Fig. 3, Ref. 25).

Development of a slow polycolloid-releasing substrate (SPRS) biobarrier to remediate TCE-contaminated aquifers

In this study, an in situ slow polycolloid-releasing substrate (SPRS) biobarrier system was developed to continuously provide biodegradable substrates for the enhancement of trichloroethylene (TCE) reductive dechlorination. The produced SPRS contained vegetable oil (used as a slow-released substrate), cane molasses [used as an early-stage (fast-degradable) substrate], and surfactants [Simple Green (SG) and soya lecithin (SL)]. An emulsification study was performed to evaluate the globule droplet size and stability of SPRS. The distribution and migration of the SPRS were evaluated in a column experiment, and an anaerobic microcosm study was performed to assess the capability of SPRS to serve as a slow and long-term carbon-releasing substrate for TCE dechlorination. The results show that a stable oil-in-water (W/O, 50/50) emulsion (SPRS) with uniformly small droplets (D₁₀, 0.93 μm) has been produced, continuously supplying primary substrates. The emulsion containing the surfactant mixture (with 72 mg/L SL and 71 mg/L SG) had a small absolute value of the zeta potential, which reduced the inter-particle repulsion, leading the emulsion droplets to adhere to one another after collision. The addition of SPRS creates anaerobic conditions and leads to a more complete and thorough removal of TCE through biodegradation and sorption mechanisms.

Myeloid-derived suppressor cells as a Trojan horse: A cellular vehicle for the delivery of oncolytic viruses

We have recently demonstrated that oncolytic vesicular stomatitis viruses can be efficiently and selectively delivered to neoplastic lesions by myeloid-derived suppressor cells (MDSCs). Importantly, the loading of viruses onto MDSCs inhibited their immunosuppressive properties and endowed them with immunostimulatory and tumoricidal functions. Our study demonstrates the potential use of MDSCs as a Trojan horse for the tumor-targeted delivery of various anticancer therapeutics.

Abstract 56: Macrophage Reverse Cholesterol Transport in Mice Relies on The Lymphatic Vasculature

Reverse cholesterol transport (RCT) refers to mobilization of cholesterol on HDL particles (HDL-C) from extravascular tissues to plasma, ultimately for fecal excretion. Little is known about how HDL-C leaves peripheral tissues to reach plasma. We first used two models of disrupted lymphatic drainage from skin -one surgical and the other genetic- to quantitatively track RCT following injection of [3H]cholesterol-loaded macrophages upstream of blocked or absent lymphatic vessels. Macrophage RCT was markedly impaired in both models, even at sites with a leaky vasculature. Inhibited RCT was downstream of cholesterol efflux from macrophages, since macrophage efflux of a fluorescent cholesterol analogue (BODIPY-cholesterol) was not altered by impaired lymphatic drainage. We next addressed whether RCT was mediated by lymphatic vessels from the aortic wall by loading the aorta of donor atherosclerotic apoE-/- mice with [2H]6-labeled cholesterol and surgically transplanting these aortas into recipient apoE-/- mice that were treated with anti-VEGFR3 mAb to block lymphatic regrowth or with control mAb to allow such regrowth. [2H]-Cholesterol was retained in aortas of anti-VEGFR3 treated mice. Thus, the lymphatic vessel route is critical for RCT from multiple tissues, including the aortic wall. Therefore, supporting lymphatic transport function may facilitate cholesterol clearance in therapies aimed at reversing atherosclerosis.

Myeloid-derived suppressor cells as a vehicle for tumor-specific oncolytic viral therapy

One of the several impediments to effective oncolytic virus therapy of cancer remains a lack of tumor-specific targeting. Myeloid-derived suppressor cells (MDSC) are immature myeloid cells induced by tumor factors in tumor-bearing hosts. The biodistribution kinetics of MDSC and other immune cell types in a murine hepatic colon cancer model was investigated through the use of tracking markers and MRI. MDSCs were superior to other immune cell types in preferential migration to tumors in comparison with other tissues. On the basis of this observation, we engineered a strain of vesicular stomatitis virus (VSV), an oncolytic rhabdovirus that bound MDSCs and used them as a delivery vehicle. Improving VSV-binding efficiency to MDSCs extended the long-term survival of mice bearing metastatic colon tumors compared with systemic administration of wild-type VSV alone. Survival was further extended by multiple injections of the engineered virus without significant toxicity. Notably, direct tumor killing was accentuated by promoting MDSC differentiation towards the classically activated M1-like phenotype. Our results offer a preclinical proof-of-concept for using MDSCs to facilitate and enhance the tumor-killing activity of tumor-targeted oncolytic therapeutics.

Polarization and reprogramming of myeloid-derived suppressor cells

Myeloid-derived suppressor cells (MDSC) have recently emerged as one of the central regulators of the immune system. In recent years, interest in understanding MDSC biology and applying MDSC for therapeutic purpose has exploded exponentially. Despite recent progress in MDSC biology, the mechanisms underlying MDSC development from expansion and activation to polarization in different diseases remain poorly understood. More recent studies have demonstrated that two MDSC subsets, M (monocytic)-MDSC and G (granulocytic)-MDSC, are able to polarize from a classically activated phenotype (M1) to an alternatively activated one (M2), or vice versa, in tumor-bearing mice. This phenotypic polarization affects MDSC function and disease progression. In this article, we summarize and discuss polarization, mechanism and therapeutic potential of MDSC. An emphasis is placed on the emerging concept of reprogramming MDSC polarization as a therapeutic strategy.

Lymphatic vasculature mediates macrophage reverse cholesterol transport in mice

Reverse cholesterol transport (RCT) refers to the mobilization of cholesterol on HDL particles (HDL-C) from extravascular tissues to plasma, ultimately for fecal excretion. Little is known about how HDL-C leaves peripheral tissues to reach plasma. We first used 2 models of disrupted lymphatic drainage from skin--1 surgical and the other genetic--to quantitatively track RCT following injection of [3H]-cholesterol-loaded macrophages upstream of blocked or absent lymphatic vessels. Macrophage RCT was markedly impaired in both models, even at sites with a leaky vasculature. Inhibited RCT was downstream of cholesterol efflux from macrophages, since macrophage efflux of a fluorescent cholesterol analog (BODIPY-cholesterol) was not altered by impaired lymphatic drainage. We next addressed whether RCT was mediated by lymphatic vessels from the aortic wall by loading the aortae of donor atherosclerotic Apoe-deficient mice with [2H]6-labeled cholesterol and surgically transplanting these aortae into recipient Apoe-deficient mice that were treated with anti-VEGFR3 antibody to block lymphatic regrowth or with control antibody to allow such regrowth. [2H]-Cholesterol was retained in aortae of anti-VEGFR3-treated mice. Thus, the lymphatic vessel route is critical for RCT from multiple tissues, including the aortic wall. These results suggest that supporting lymphatic transport function may facilitate cholesterol clearance in therapies aimed at reversing atherosclerosis.

Myostatin downregulates the expression of basic fibroblast growth factor gene in HeLa cells

Basic fibroblast growth factor (bFGF or FGF-2), a potent tumorigenic cytokine, improves cells proliferation and angiogenesis in tumor and also plays vital roles in tumor growth, metastasis as well as prognosis. Screening and application of effective cytokines against bFGF tumorigenic activity would be helpful to oncologic therapy. Myostatin, a member of transforming growth factor β superfamily, recently showed an antitumor activity and was reported to induce HeLa cells apoptosis through mitochondrion pathway. The above data raised our assumption that expression level of endogenous bFGF gene may be suppressed by exogenous myostatin in myostatin-treated HeLa cells. To test the hypothesis, myostatin was employed to stimulate HeLa cells and expressional level of endogenous bFGF gene in HeLa cells was detected with real-time RT-PCR and ELISA. Results of the suppressed expression level of bFGF gene in Hela cells implied that myostatin may be regarded as an effective cytokine against bFGF to treat certain cancers (Fig. 3, Ref. 26).