[Intratympanic dexamethasone vesus post-auricular subperiosteal injection of methylprednisolone treatment for sudden hearing loss]

Objective:To compare the efficacy and side effect between intratympanic dexamethasone and subperiosteal injection of methylprednisolone treatment for sudden hearing loss.Method:One hundred and eight unilateral sudden hearing loss patients were enrolled in this study, randomly divided into A group, which was accepted intratympanic dexamethasone (10 mg/ml) , and B group, which was accepted post-auricular subperiosteal injection of methylprednisolone (40 mg/ml) by every 3 days intotal 5 times. After 3 months follow-up, analysis of the differences of pure tone threshold, tinnitus handicap inventory (THI), dizziness handicap inventory (DHI), blood glucose between pretreatment and postreatment was made. Side effect such as perforation of tympanic membrane, infection of post-auricular skin was also observed.Result:①Both in A and B group, there was no statistical changes in total efficiency and pure tone threshold decrease (P> 0.05), whereas the pure tone threshold statistical change was observed in the low frequency sudden deafness between A and B group (P< 0.05). ②Both in A and B group, there was no statistical changes in THI (P> 0.05), whereas the THI statistical decrease was observed in the high frequency sudden deafness between A and B group (P< 0.05). ③There was no statistical change in THI both in A and B group (P> 0.05). ④Both in A and B group, there was no statistical changes in fasting plasma glucose between pretreatment and postreatment (P> 0.05). ⑤There was no patient who had gotten tympanitis or postauricular infection, although in A group, there were 2 patients had gotten perforation of tympanic membrane, but they all healed after the follow-up.Conclusion:Both topical injection of glucocorticoid can improve pure tone threshold and reduce the score of THI and DHI for sudden hearing loss patients. Intratympanic dexamethasone can reduce more score of THI for high frequency sudden deafness patients whereas subperiosteal injection of methylprednisolone can improve pure tone threshold more for low frequency sudden deafness patients. None of the two administrations elevate blood glucose, but intratympanic dexamethasone have the risk of perforation of tympanic membrane.

Tailoring the optical properties of atomically-thin WS2via ion irradiation

Two-dimensional transition metal dichalcogenides (TMDCs) exhibit excellent optoelectronic properties. However, the large band gaps in many semiconducting TMDCs make optical absorption in the near-infrared (NIR) wavelength regime impossible, which prevents applications of these materials in optical communications. In this work, we demonstrate that Ar⁺ ion irradiation is a powerful post-synthesis technique to tailor the optical properties of the semiconducting tungsten disulfide (WS₂) by creating S-vacancies and thus controlling material stoichiometry. First-principles calculations reveal that the S-vacancies give rise to deep states in the band gap, which determine the NIR optical absorption of the WS₂ monolayer. As the density of the S-vacancies increases, the enhanced NIR linear and saturable absorption of WS₂ is observed, which is explained by the results of first-principles calculations. We further demonstrate that by using the irradiated WS₂ as a saturable absorber in a waveguide system, the passively Q-switched laser operations can be optimized, thus opening new avenues for tailoring the optical response of TMDCs by defect-engineering through ion irradiation.

Maternal pre-gravid cardiometabolic health and infant birthweight: A prospective pre-conception cohort study

BACKGROUND AND AIMS

Both low birthweight and high birthweight have been associated with the development of cardiometabolic disease in adulthood, possibly reflecting the effect of intrauterine fetal programming. As developmental programming can begin before conception, pre-gravid factors that predict birthweight may be relevant in this context. However, little is known about such factors. Thus, we established a pre-conception cohort to identify maternal pre-gravid cardiometabolic determinants of infant birthweight.

METHODS AND RESULTS

In this prospective observational cohort study, 1484 newly-married women in Liuyang, China, underwent baseline (pre-gravid) evaluation and then were followed across a subsequent pregnancy. Pre-gravid cardiometabolic characterization consisted of clinical (anthropometry, blood pressure) and biochemical evaluation (total/LDL/HDL cholesterol, triglycerides, glucose) at median 20 weeks before a singleton pregnancy. Mean birthweight was 3294 ± 444 g, with 173 neonates large-for-gestational-age (LGA) and 110 small-for-gestational-age (SGA). On multiple linear regression analysis, positive determinants of birthweight were maternal age, pre-gravid body mass index (BMI), weight gain in pregnancy, length of gestation, and male infant (all p ≤ 0.0003). On logistic regression analysis, independent predictors of an LGA delivery were maternal age (OR = 1.10 per year, 95%CI 1.03-1.18), pre-gravid BMI (OR = 1.21 per kg/m², 1.07-1.37), and gestational weight gain (OR = 1.10 per kg, 1.06-1.14). The only independent predictor of SGA was gestational weight gain (OR = 0.93 per kg, 0.89-0.97).

CONCLUSION

Maternal weight before and during pregnancy is the predominant cardiometabolic determinant of infant birthweight, rather than pre-gravid blood pressure, glucose or lipid profile.

Population dynamics of hepatitis C virus subtypes in injecting drug users on methadone maintenance treatment in China associated with economic and health reform

The extensive genetic heterogeneity of hepatitis C virus (HCV) requires in-depth understanding of the population dynamics of different viral subtypes for more effective control of epidemic outbreaks. We analysed HCV sequences data from 125 participants in Wuhan, China. These participants were newly infected by subtype 1b (n=13), 3a (n=15), 3b (n=50) and 6a (n=39) while on methadone maintenance treatment (MMT). Bayesian phylogenies and demographic histories were inferred for these subtypes. Participants infected with HCV-1b and 3a were clustered in well-supported monophyletic clades, indicating local subepidemics. Subtypes 3b and 6a strains were intermixed with other Chinese isolates, as well as isolates from other Asian countries, reflecting ongoing across geographic boundary transmissions. Subtypes 1b and 3a declined continuously during the past ten years, consistent with the health and economic reform in China, while subtype 3b showed ongoing exponential growth and 6a was characterized by several epidemic waves, possibly related to the recently growing number of travellers between China and other Asian countries. In conclusion, results of this study suggest that HCV subtype 3b and 6a subepidemics in China are currently not under control, and new epidemic waves may emerge given the rapid increase in international travelling following substantial economic growth.

Body mass index and mortality in lung cancer patients: a systematic review and meta-analysis

Studies examining the relation of body mass index (BMI) and mortality in patients with lung cancer have shown diverse results. We conducted a meta-analysis to investigate the association using all available studies from January 1982 to October 2016. PubMed and EMBASE were searched to identify relevant studies. We calculated the summary hazard ratio (HR) and 95% confidence interval (CI) using random effects model. The dose-response relationship was assessed by random effects meta-regression model. Fifty-five articles from 51 studies involving 3 152 552 subjects (males, 54.8%) were included. The pooled results suggested that on average a high BMI decreased risk of death from lung cancer or all-cause. Each 5 kg/m² increase in BMI had a 12% lower risk of lung cancer-specific mortality (HR=0.88, 95% CI: 0.75-1.02, P=0.09) and a 14% lower risk of all-cause mortality (HR=0.86, 95% CI: 0.77-0.96, P<0.01). When stratifying by ethnicity, each 5 kg/m² increase in BMI was associated with 22% and 28% reduction, respectively, in the risk of lung cancer-specific mortality (P<0.01) and all-cause mortality (P<0.01) in Asians, but no association was found in Westerners (P=0.51 and P=0.53, respectively). In conclusion, lung cancer patients with a higher BMI have a longer survival than those with a lower BMI. Considering the significant heterogeneity between included studies, future studies are needed to confirm these findings.

High-salt diet induces outward remodelling of efferent arterioles in mice with reduced renal mass

AIM

The glomerular filtration rate (GFR) falls progressively in chronic kidney disease (CKD) which is caused by a reduction in the number of functional nephrons. The dysfunctional nephron exhibits a lower glomerular capillary pressure that is induced by an unbalance between afferent and efferent arteriole. Therefore, we tested the hypothesis that oxidative stress induced by CKD differentially impairs the structure or function of efferent vs. afferent arterioles.

METHODS

C57BL/6 mice received sham operations (sham) or 5/6 nephrectomy (RRM) and three months of normal- or high-salt diet or tempol. GFR was assessed from the plasma inulin clearance, arteriolar remodelling from media/lumen area ratio, myogenic responses from changes in luminal diameter with increases in perfusion pressure and passive wall compliance from the wall stress/strain relationships.

RESULTS

Mice with RRM fed a high salt (vs. sham) had a lower GFR (553 ± 25 vs. 758 ± 36 μL min^-1  g^-1 kidney, P < 0.01) and a larger efferent arteriolar diameter (9.6 ± 0.8 vs. 7.4 ± 0.7 μm, P < 0.05) resulting in a lower media/lumen area ratio (1.4 ± 0.1 vs. 2.4 ± 0.2, P < 0.01). These alterations were corrected by tempol. The myogenic responses of efferent arterioles were about one-half that of afferent arterioles and were unaffected by RRM or salt. Passive wall compliance was reduced by high salt in both afferent and efferent arterioles.

CONCLUSION

A reduction in renal mass with a high-salt diet induces oxidative stress that leads to an outward eutrophic remodelling in efferent arterioles and reduced wall compliance in both afferent and efferent arterioles. This may contribute to the lower GFR in this model of CKD.

Abstract P6-07-29: Heterogeneity of PD-L1 expression in primary tumors and paired lymph node metastases of triple negative breast cancer

This abstract was not presented at the symposium.

An integrated analysis identifies STAT4 as a key regulator of ovarian cancer metastasis

Epithelial ovarian cancer (EOC) is one of the most common gynecological cancers, with diagnosis often at a late stage. Metastasis is a major cause of death in patients with EOC, but the underlying molecular mechanisms remain obscure. Here, we utilized an integrated approach to find potential key transcription factors involved in ovarian cancer metastasis and identified STAT4 as a critical player in ovarian cancer metastasis. We found that activated STAT4 was overexpressed in epithelial cells of ovarian cancer and STAT4 overexpression was associated with poor outcome of ovarian cancer patients, which promoted metastasis of ovarian cancer in both in vivo and in vitro. Although STAT4 mediated EOC metastasis via inducing epithelial-to-mesenchymal transition (EMT) of ovarian cancer cells in vivo, STAT4 failed to induce EMT directly in vitro, suggesting that STAT4 might mediate EMT process via cancer-stroma interactions. Further functional analysis revealed that STAT4 overexpression induced normal omental fibroblasts and adipose- and bone marrow-derived mesenchymal stem cells to obtain cancer-associated fibroblasts (CAF)-like features via induction of tumor-derived Wnt7a. Reciprocally, increased production of CAF-induced CXCL12, IL6 and VEGFA within tumor microenvironment could enable peritoneal metastasis of ovarian cancer via induction of EMT program. In summary, our study established a model that STAT4 promotes ovarian cancer metastasis via tumor-derived Wnt7a-induced activation of CAFs.

[Epidemiological analysis of the deaths of malaria in China, 2005-2014]

OBJECTIVE

To explore the epidemiological features of deaths of malaria from 2005 to 2014, so as to provide the evidence for subsequently more effective strategic planning of malaria elimination in China.

METHODS

The data of individual malaria cases (including probable and confirmed cases, population data, geographic distribution, diagnosis and reporting information) were obtained from the National Notifiable Infectious Disease Reporting Information System from 2005 to 2014 and the epidemiological investigation information (including the clinical systems and the imported and indigenous cases) was extracted from Parasite Disease Prevention and Control Information System from 2011 to 2014. All of the data didn't include Hongkong, Macao, Taiwan and foreign cases. The population characteristics, clinical systems, geographic distribution, diagnosis and reporting and sources of infections of deaths were analyzed.

RESULTS

From 2005 to 2014, a total of 228 deaths of malaria were reported, with 203 (89.0%) of P. falciparum malaria, 13 (5.7%) of P. vivax malaria, 1 (0.5%) of P. malariae malaria and 11(4.8%) other cases. The fatality rate of malaria increased since 2010. Among the deaths, 48 (81.4% ) had serious complications, which included cerebral lesion, coma, severe renal and hepatic injuries and hemolysis and so on. In 2005-2010, the geographical distribution of malaria deaths was mainly in Yunnan (78 deaths, 56.1%), Sichuan (13 deaths, 9.4%), Henan (7 deaths, 5.0%), Shandong (6 deaths, 4.3%) and Zhejiang (5 deaths, 3.6%) province. However, since the initiation of malaria elimination program in 2010, the areas with malaria deaths have changed, which mainly distributed in Henan (10 deaths, 11.2%), Sichuan (9 deaths, 10.1%), Shandong (8 deaths, 9.0%), Jiangsu (7 deaths, 7.9%) and Hunan province (7 deaths, 7.9%). Besides there were nine deaths (10.0%) reported in non-endemic areas of malaria (Beijing, Inner Mongolia, Jilin, and Ningxia) in 2011-2014. The median time from illness onset to diagnosis for deaths was 5.5 (P25-P75: 3.0-8.5) d, which was longer than 3.0 (2.0-6.0)d for survivors. Moreover, for deaths, the median P50 (P25-P75)(6.0, 4.0-9.0 d) from illness onset to diagnosis in 2011-2014 was longer than that in 2005-2010 (5.0, 3.0-9.0 d). Among imported deaths, 77 deaths (90.6%) originated from Africa and 8 deaths (9.4%) from Southeast Asia.

CONCLUSION

Although the reported deaths of malaria were stable in 2005-2014, the geographical distribution of malaria deaths changed significantly and the time from illness onset to the diagnosis was longer since 2010. Special attention should be paid to the diagnosis and treatment of imported cases to reduce the fatality at the malaria elimination stage.

Quantitative Glycomics: A Combined Analytical and Bioinformatics Approach

Glycosylation is one of the most common and essential protein modifications. Glycans conjugated to biomolecules modulate the function of such molecules through both direct recognition of glycan structures and indirect mechanisms that involve the control of protein turnover rates, stability, and conformation. The biological attributes of glycans in numerous biological processes and implications in a number of diseases highlight the necessity for comprehensive characterization of protein glycosylation. This chapter reviews cutting-edge methods and tools developed to facilitate quantitative glycomics. This chapter highlights the different methods employed for the release and purification of glycans from biological samples. The most effective labeling methods developed for sensitive quantitative glycomics are also described and discussed. The chromatographic approaches that have been used effectively in glycomics are also highlighted.

Exogenous fibroblast growth factor 9 attenuates cartilage degradation and aggravates osteophyte formation in post-traumatic osteoarthritis

OBJECTIVE

The aim of the present study is to investigate the effects of exogenous fibroblast growth factor (FGF)9 on the progression of post-traumatic osteoarthritis (OA).

DESIGN

The expression of FGF9 in articular cartilage with OA is detected by immunohistochemistry (IHC). The effects of intra-articular exogenous FGF9 injection on post-traumatic OA induced by the destabilization of the medial meniscus (DMM) surgery are evaluated. Cartilage changes and osteophyte formation in knee joints are investigated by histological analysis. Changes in subchondral bone are evaluated by microcomputed tomography (micro-CT). The effect of exogenous FGF9 on an interleukin-1β (IL-1β)-induced ex vivo OA model of human articular cartilage tissues is also evaluated.

RESULTS

FGF9 expression was down-regulated in articular chondrocytes of OA but ectopically induced at sites of osteophyte formation. Intra-articular injection of exogenous FGF9 attenuated articular cartilage degradation in mice after DMM surgery. Exogenous FGF9 suppressed collagen X and MMP13 expressions in OA cartilage, while promoted collagen II expression. Similar results were observed in IL-1β-induced ex vivo OA model. Intra-articular injection of FGF9 had no significant effect on the subchondral bone of knee joints after DMM surgery, but aggravated osteophyte formation. The expressions of SOX9 and collagen II, and cell proliferation were up-regulated at sites of initial osteophyte formation in mice with exogenous FGF9 treatment.

CONCLUSIONS

Intra-articular injection of exogenous FGF9 delays articular cartilage degradation in post-traumatic OA, while aggravates osteophyte formation.

Vitamin D metabolism and regulation in pediatric MSCs

Vitamin D is crucial for mineral homeostasis and contributes to bone metabolism by inducing osteoblast differentiation of marrow stromal cells (MSCs). We recently reported that MSCs from adults demonstrate 1α-hydroxylase activity in vitro and express vitamin D-related genes; this raises a possible autocrine/paracrine role for D activation in pre-osteoblasts. In this studies, we tested the hypotheses that pediatric MSCs have 1α-hydroxylase activity and express vitamin D-related genes. With IRB approval, we isolated MSCs from discarded excess iliac marrow graft from 6 male and 6 female subjects (age 8-12 years) undergoing alveolar cleft repair. 1α-hydroxylation of substrate 25(OH)D₃ was measured by ELISA for 1α,25(OH)₂D. RT-PCR was used for gene expression. Pediatric MSCs showed a range of 1α-hydroxylase activity in vitro. There was constitutive expression of vitamin D receptor (VDR), megalin, d-hydroxylases (CYP27B1, CYP27A1, CYP2R1, and CYP24A1), and estrogen receptor (ER). There was 2.6-fold greater expression of CYP27B1 and 3.5-fold greater expression of CYP24A1 in MSCs from boys compared with girls. There was 2.4-fold greater expression of ERα and 3.2-fold greater expression of megalin in MSCs from boys. In preliminary studies, treatment of female pediatric MSCs with 10nM 17β-estradiol resulted in upregulation of CYP27B1 and CYP24A1, as well as VDR, megalin, ERα, and ERβ. Treatment with 25(OH)D₃ upregulated CYP27B1, VDR, and ERα. Expression and regulation of vitamin D related genes in pediatric hMSCs reinforces an autocrine/paracrine role for vitamin D in hMSCs. Finding striking gender differences in MSCs from children was not seen with MSCs from adults and adds insight to the metabolic environment of bone and presents a research approach for investigating and optimizing pediatric bone health.

FKBP12 enhances sensitivity to chemotherapy-induced cancer cell apoptosis by inhibiting MDM2

The FK506-binding protein 12 (FKBP12) is a cytoplasmic protein and has been reported to possess multiple functions in signaling transduction based on its interaction with different cellular targets. Here, we report that FKBP12 interacts with oncoprotein MDM2 and induces MDM2 degradation. We demonstrate that FKBP12 degrades MDM2 through binding to MDM2 protein, disrupting MDM2/MDM4 interaction and inducing MDM2 self-ubiquitination. The FKBP12-mediated MDM2 degradation was significantly enhanced when the transfected MDM2 was localized in the cytoplasm. The endogenous MDM2, when it was induced by p53 subjecting to DNA-damaging stimuli such as treatment with doxorubicin, was also significantly inhibited by FKBP12. This is due to translocation of p53-induced MDM2 from the nucleus to the cytoplasm, which facilitates interaction with cytoplasmic FKBP12. Furthermore, the enhanced level of MDM2 following p53 activation in nutlin-3 treated cells was also inhibited by FKBP12. The FKBP12-mediated downregulation of MDM2 in response to doxorubicin or nutlin-3 results in continuing and constitutive activation of p53, inhibition of XIAP and sensitization of cancer cells to apoptosis. These results identify a novel function for FKBP12 in downregulating MDM2, which directly enhances sensitivity of cancer cells to chemotherapy and nutlin-3 treatment.

Characterization of Th17 and FoxP3(+) Treg Cells in Paediatric Psoriasis Patients

Psoriasis is one of the most common inflammatory skin conditions affecting both children and adults. Growing evidence indicates that T-helper 17 (Th17) cells and CD4(+) CD25(+) regulatory T (Treg) cells play an important role in the pathogenesis of psoriasis. However, the relationship between Th17 and Treg cells and their dynamic variations in paediatric psoriasis remain unclear. In this study, we found that both Th17 and FoxP3(+) Treg cells and the ratio of Th17 to Treg cell frequency in the peripheral circulation were increased in patients with paediatric psoriasis and were positively correlated with the disease severity. The function of Treg to suppress CD4(+) CD25(-) T cell proliferation and IFN-γ secretion was impaired during the onset of psoriasis. After disease remission, both the Th17 and Treg cell frequencies were decreased, and the suppressive function of the Treg cells was obviously restored. However, neither Treg cells from the disease onset nor those after remission can regulate IL-17 secretion by CD4(+) T cells. These findings will further our understanding of the associations between Th17 and Treg cells in paediatric psoriasis and their influence on disease severity.

Group III mGluR8 negatively modulates TRPA1

Several lines of evidence indicate group III metabotropic glutamate receptors (mGluRs) have systemic anti-hyperalgesic effects. We hypothesized this could occur through modulation of TRP channels on nociceptors. This study used a multifaceted approach to examine the interaction between group III mGluRs (mGluR8) and transient receptor potential ankyrin 1 (TRPA1) on cutaneous nociceptors in rats. Ca²⁺ imaging studies demonstrated co-localization and functional coupling of TRPA1 and mGluR8, since 1μM (S)-3,4-dicarboxyphenylglycine (DCPG) (mGluR8 agonist) significantly reduced Ca²⁺ mobilization produced by 30μM mustard oil (MO), a TRPA1 agonist. Behavioral studies demonstrated that 10mM MO produced mechanical hypersensitivity when topically applied to the hind paw, significantly decreasing paw withdrawal threshold (PWT) from 15g to 6g. However, administration of 30μM DCPG prior to 10mM MO reversed this hypersensitivity such that PWT was not significantly different from baseline. At the single-fiber level, compared to vehicle, 30μM MO significantly increased nociceptor activity and decreased mechanical threshold. However, 30μM DCPG reversed both of these MO-induced effects. Furthermore, DCPG significantly reduced the number of MO-induced mechanically sensitive fibers. Inhibition of protein kinase A (PKA) using Rp-cyclic 3',5'-hydrogen phosphorothioate adenosine triethylammonium salt (RpCAMPS) (PKA inhibitor, 1 and 10μM) significantly reduced MO-induced Ca²⁺ mobilization. Taken together, these results show that group III mGluRs negatively modulate TRPA1 activity on cutaneous nociceptors. Furthermore, it is likely that this modulation occurs intracellularly at the level of the cAMP/PKA pathway. This study demonstrates that group III agonists may be effective in the treatment of mechanical hypersensitivity which can develop as a result of inflammation, nerve injury, chemotherapy and other disease states.

The probability that the largest observation is censored

Suppose n possibly censored survival times are observed under an independent censoring model, in which the observed times are generated as the minimum of independent positive failure and censor random variables. A practical difficulty arises when the largest observation is censored since then the usual non-parametric estimator of the distribution of the survival time is improper. We calculate the probability that this occurs and give necessary and sufficient conditions for this probability to converge to 0 as n →∞. As an application, we show that if this probability is 0, asymptotically, then a consistent estimator for the mean failure time can be found. An almost sure version of the problem is also considered.

Mechanical Strain Promotes Osteogenesis of BMSCs from Ovariectomized Rats via the ERK1/2 but not p38 or JNK-MAPK Signaling Pathways

Osteoporosis has become a world-wide health problem. As a promising intervention, mechanical strain is considered to be an important factor in bone remodeling. However, the underlying mechanisms are still not clarified clearly. In the present study, we aim to investigate the possible mechanism by which mechanical stimulation induces osteogenic differentiation of bone mesenchymal stem cells (BMSCs) from ovariectomized rats (OVX BMSCs). The results demonstrated that intermittent mechanical strain (IMS) promoted osteogenic differentiation of OVX BMSCs by activating Runt-related transcription factor 2 (Runx2). When the extracellular regulated kinase1/2-mitogen activated protein kinases (ERK1/2-MAPK) signaling pathway was blocked, the osteogenenic effects of IMS were diminished; while blocking of the p38-MAPK signaling pathway had little effect on subsequent osteogenic events. In addition, the phosphorylation level of JNK was not affected by IMS. Our results indicated that strain-induced osteogenic differentiation of OVX BMSCs may take effect via ERK1/2-MAPK not p38 or c-Jun N-terminal (JNK)-MAPK signaling pathway. These findings may have implications for physical treatment of osteoporosis in vitro.

Quantification of adherent platelets on polymer-based biomaterials. Comparison of colorimetric and microscopic assessment

BACKGROUND

Platelet adhesion to artificial surfaces is one of the most important indicators for the thrombogenicity of implant materials. Currently, a variety of enzyme activity-based colorimetric assays or microscopy-based techniques are commonly in use to assess this characteristic. Studies about how data of colorimetric assays correlate with the image-based quantification of adherent platelets are scarce. To address this question, the present study compared two colorimetric assays (lactate dehydrogenase (LDH) and acid phosphatase (ACP)) with an image-based quantification of the density of platelets adhering on polymer-based biomaterial surfaces.

MATERIALS AND METHODS

Tri-sodium citrated whole blood was collected from apparently healthy subjects and platelet rich plasma (PRP) was prepared according to a standardized protocol. An in vitro static thrombogenicity test was applied to study platelet adhesion from PRP adjusted to 50,000 platelets per μL on three different polymers: medical grade polytetrafluoroethylene (PTFE), silicone and polyethylene terephthalate (PET). For the direct image-based approach, surface adherent platelets were fixed, fluorescently labelled and microscopically visualized. The image-based determination of platelet densities provided reference values for the comparison with data of the colorimetric assays. Correlation between standard platelet concentrations and ACP/LDH absorbance measurements were analysed to estimate accuracy and association of both parameters. ACP and LDH release from resting and ADP-stimulated platelets was studied to estimate how platelet activation influences colorimetric assay results.

RESULTS

The density of adherent platelets ranged from 15,693 ± 2,487 platelets·mm-2 (PTFE) to 423 ± 99 platelets·mm-2 (silicone) and 4,621 ± 1,427 platelets·mm-2 (PET) and differed significantly between the three polymers (ANOVA: p <  0.05). Correlation coefficients between microscopic and colorimetric determination of platelet densities ranged between r = 0.93 (LDH, p <  0.001) and r = 0.94 (ACP, p <  0.001). ACP absorbance measurements of platelet standards with different concentrations corresponded well to an ideal linear regression, while LDH data either deceeded or exceeded the expected values. The LDH release during ADP-induced platelet activation was significantly higher compared to the release of ACP.

CONCLUSION

For an adjusted platelet concentration of 50,000 platelets·μL-1, both colorimetric assays (ACP and LDH) allowed a similar accurate quantification of the mean platelet density compared to the microscopic evaluation. Better linearity of the assay standards, less variability of the results and a lower influence of platelet activation on the measurements mark the ACP assay as more suitable for the assessment of material surface adherent platelets compared to the LDH assay, particularly, if near physiological platelet concentrations are applied.

Class I HDAC inhibitor mocetinostat induces apoptosis by activation of miR-31 expression and suppression of E2F6

The class I selective inhibitor of the histone deacetylases, mocetinostat, has promising antitumor activities in both preclinical studies and the clinical trials. To understand how mocetinostat induces apoptosis, we examined the effects of mocetinostat on miR-31, a proapoptotic microRNA that was previously found to be epigenetically silenced in prostate cancer. We found that miR-31 was significantly upregulated by mocetinostat in prostate cancer cells. Antiapoptotic protein E2F6, the target of miR-31, was decreased by mocetinostat treatment. When miR-31 was blocked with an inhibitor, the ability of mocetinostat to induce apoptosis was reduced. We further demonstrated that mocetinostat enhanced the activity of docetaxel in apoptosis induction. While siRNA knockdown of E2F6 sensitized cancer cells to mocetinostat-induced apoptosis, overexpression of E2F6 blocked mocetinostat-induced apoptosis. In an orthotopic xenograft model, we demonstrated that mocetinostat activated miR-31, decreased E2F6, induced apoptosis, and significantly reduced prostate cancer growth. Importantly, we found that mocetinostat also increased miR-31 expression, decreased E2F6, and induced apoptosis in the primary prostate cancer stem cells. Thus, activation of miR-31 and downregulation of E2F6 constitute an important mechanism in mocetinostat-induced apoptosis in prostate cancer.