RLS adaptive filtering for physiological interference reduction in NIRS brain activity measurement: a Monte Carlo study

The non-invasive measurement of cerebral functional haemodynamics using near-infrared spectroscopy (NIRS) instruments is often affected by physiological interference. The suppression of this interference is crucial for reliable recovery of brain activity measurements because it can significantly affect the signal quality. In this study, we present a recursive least-squares (RLS) algorithm for adaptive filtering to reduce the magnitude of the physiological interference component. To evaluate it, we implemented Monte Carlo simulations based on a five-layer slab model of a human adult head with a multidistance source-detector arrangement, of a short pair and a long pair, for NIRS measurement. We derived measurements by adopting different interoptode distances, which is relevant to the process of optimizing the NIRS probe configuration. Both RLS and least mean squares (LMS) algorithms were used to attempt the removal of physiological interference. The results suggest that the RLS algorithm is more capable of minimizing the effect of physiological interference due to its advantages of faster convergence and smaller mean squared error (MSE). The influence of superficial layer thickness on the performance of the RLS algorithm was also investigated. We found that the near-detector position is an important variable in minimizing the MSE and a short source-detector separation less than 9 mm is robust to superficial layer thickness variation.

Response to the first wave of pandemic (H1N1) 2009: experiences and lessons learnt from China

More than 2 years after the start of pandemic H1N1, the world is fortunate that the impact, to date, has been moderate. An evaluation of the global response to the first wave of the pandemic is still ongoing. The results of an analysis of the situation in China is presented in order to gain a better understanding of the episode; to summarize the experiences in preparedness, control and mitigation of the pandemic; and to identify issues for further consideration and investigation in order to improve the response to possible next waves of the pandemic. China's response shows how a huge challenge can be transformed into an opportunity, and may offer some valuable lessons to face another wave of the pandemic or other potential public health emergencies in the future, not only for China but also for the international community.

Effect of green tea and Tai Chi on bone health in postmenopausal osteopenic women: a 6-month randomized placebo-controlled trial

Postmenopausal women with osteopenia received green tea polyphenols (GTP) supplement and/or Tai Chi exercise for 6 months. Bone turnover biomarkers, calcium metabolism, and muscle strength were measured. This study showed that GTP supplementation and Tai Chi exercise increased bone formation biomarkers and improved bone turnover rate. Tai Chi exercise increased serum parathyroid hormone. GTP supplementation, Tai Chi exercise, and the combination of the two all improved muscle strength in postmenopausal women with osteopenia.

INTRODUCTION

This study evaluated the effect of GTP supplementation and Tai Chi (TC) exercise on serum markers of bone turnover (bone-specific alkaline phosphatase, BAP, and tartrate-resistant acid phosphatase, TRAP), calcium metabolism, and muscle strength in postmenopausal osteopenic women.

METHODS

One hundred and seventy-one postmenopausal osteopenic women were randomly assigned to four groups: (1) placebo (500 mg starch/day), (2) GTP (500 mg GTP/day), (3) placebo + TC (placebo plus TC training at 60 min/session, three sessions/week), and (4) GTP + TC (GTP plus TC training). Overnight fasting blood and urine samples were collected at baseline, 1, 3, and 6 months for biomarker analyses. Muscle strength was evaluated at baseline, 3, and 6 months. One hundred and fifty subjects completed the 6-month study.

RESULTS

Significant increases in BAP level due to GTP intake (at 1 month) and TC (at 3 months) were observed. Significant increases in the change of BAP/TRAP ratio due to GTP (at 3 months) and TC (at 6 months) were also observed. Significant main effect of TC on the elevation in serum parathyroid hormone level was observed at 1 and 3 months. At 6 months, muscle strength significantly improved due to GTP, TC, and GTP + TC interventions. Neither GTP nor TC affected serum TRAP, serum and urinary calcium, and inorganic phosphate.

CONCLUSION

In summary, GTP supplementation and TC exercise increased BAP and improved BAP/TRAP ratio. TC exercise increased serum parathyroid hormone. GTP supplementation, TC exercise, and the combination of the two all improved muscle strength in postmenopausal women with osteopenia.

DNA-PKcs interacts with Aire and regulates the expression of toll-like receptors in RAW264.7 cells

The autoimmune regulator (Aire) is a key mediator of the central tolerance for peripheral tissue self-antigen (PTAs) and is involved in the transcriptional control of many antigens in thymic medullary epithelial cells (mTECs). However, the function of Aire in peripheral lymphoid tissues and haematopoietic cells, particularly in monocytes and macrophages, remains poorly understood. We previously found that the expression of Toll-like receptor (TLR) 1, TLR3 and TLR8 was notably upregulated in pEGFPC1/Aire stably transfected RAW264.7 (GFP-Aire/RAW) cells, while the expressions of other TLRs were not significantly changed. The mechanism by which Aire affects TLR1, TLR3 and TLR8 expression is not clear. Interactions with other proteins, such as DNA-dependent protein kinase (DNA-PK), are crucial for regulating the transcriptional activity of Aire. In this study, we found that Aire and DNA-PK catalytic subunit (DNA-PKcs) were co-located in the nucleus of GFP-Aire/RAW cells, and they interact with each other. Small interfering RNA knock-down of DNA-PKcs in these cells decreased the expression of TLR1, TLR3 and TLR8, but no change was observed in pEGFPC1 stably transfected RAW264.7 (GFP/RAW) cells. We did not observe any change in the expressions of other TLRs after DNA-PKcs knock-down in GFP-Aire/RAW or GFP/RAW cells. A similar observation has been made in pEGFPC1/Aire or pEGFPC1 transiently transfected primary peritoneal macrophages. Using a luciferase activity assay, we found the that the transcriptional activity of TLR1, TLR3 and TLR8 promoters was also decreased after knock-down of DNA-PKcs in GFP-Aire/RAW cells. In conclusion, our results suggest that DNA-PKcs may interact with Aire to promote the expression of TLRs in RAW264.7 cells.

Note: measurement of the runaway electrons in the J-TEXT tokamak

The runaway electrons have been measured by hard x-ray detectors and soft x-ray array in the J-TEXT tokamak. The hard x-ray radiations in the energy ranges of 0.5-5 MeV are measured by two NaI detectors. The flux of lost runaway electrons can be obtained routinely. The soft x-ray array diagnostics are used to monitor the runaway beam generated in disruptions since the soft x-ray is dominated by the interaction between runaway electrons and metallic impurities inside the plasma. With the aid of soft x-ray array, runaway electron beam has been detected directly during the formation of runaway current plateau following the disruptions.

Interleukin-8 induces the endothelial cell migration through the Rac 1/RhoA-p38MAPK pathway

BACKGROUND AND OBJECTIVES

Endothelial cell migration is essential for tumor angiogenesis, and interleukin-8 (IL-8) has been shown to play an important role in tumor growth, angiogenesis, and metastasis. The objective of this study was to investigate the molecular mechanism of IL-8 induced endothelial cell migration in vitro.

MATERIAL AND METHODS

Fluorescence microscope was used to study the distribution of cytoskeleton. The expression of Rac1 and RhoA protein was detected by western blotting. After endothelial cells were transfected by lipofectamine 2000 reagent, the Transwell chamber motility assay was applied to observe the migration of endothelial cells induced by IL-8. The active p38MAPK (mitogen-activated protein kinase) was evaluated by the p38MAPK activation assay.

RESULTS

We demonstrated that IL-8 activated cell migration can be impaired by p38MAPK inhibitor, suggesting the participation of p38MAPK in the cell migration. Our results indicated that p38MAPK signaling is required for membrane ruffles, lamellipodia extensions, and actin stress fibers formation induced by IL-8. Furthermore, p38MAPK inhibitor led to increased Rac1 and RhoA expression in IL-8 treated EA.hy926 cells. In addition, IL-8 induced p38MAPK activation was suppressed by dominant-negative mutant for Rac1 and RhoA.

CONCLUSIONS

Our study demonstrates that IL-8-Rac1/RhoA-p38MAPK signaling pathway plays a vital role in the IL-8-induced endothelial cell migration, and it provides new insight into the molecular mechanisms by which IL-8 contributes to tumor angiogenesis and metastasis.

Changes in histone acetylation during oocyte meiotic maturation in the diabetic mouse

Although there is considerable evidence that diabetes can adversely affect meiosis in mammalian oocytes, acetylation status of oocytes in a diabetic environment remains unclear. The objective was to determine acetylation or deacetylation patterns (based on immunostaining) of H3K9, H3K14, H4K5, H4K8, H4K12, and H4K16 sites at various stages during meiosis in murine oocytes from control and diabetic mice. According to quantitative real time polymerase chain reaction (qPCR), mean ± SEM relative expression of Gcn5 (1.70 ± 0.14 at metaphase [M]I and 1.27 ± 0.01 at MII, respectively), Ep300 (1.74 ± 0.04 at MI and 1.80 ± 0.001 at MII), and Pcaf (2.01 ± 0.03 at MI and 1.41 ± 0.18 at MII) mRNA in oocytes from diabetic mice were higher than those from controls (P < 0.05), whereas there was no difference (P > 0.05) during the germinal vesicle (GV) stage between the two groups (1.23 ± 0.04 for Gcn5, 0.82 ± 0.06 for Ep300, and 0.80 ± 0.07 for Pcaf). Conversely, relative mRNA expression concentrations of Hdac1, Hdac2, Hdac3, Sirt1 and Sirt2 during the germinal vesicle stage were lower in oocytes of diabetic mice (0.24 ± 0.03 for Hdac1, 0.11 ± 0.001 for Hdac2, 0.31 ± 0.03 for Hdac3, 0.28 ± 0.02 for Sirt1, and 0.55 ± 0.02 for Sirt2; P < 0.05). Similarly, the expression concentrations of these genes at the MI stage were lower in oocytes from diabetic mice (0.79 ± 0.12 for Hdac1, 0.72 ± 0.001 for Hdac2, 0.02 ± 0.001 for Sirt1, and 0.84 ± 0.08 for Sirt2; P < 0.05). Their expression concentrations at the MII stage were also lower in oocytes from diabetic mice (0.46 ± 0.03 for Hdac1, 0.93 ± 0.01 for Hdac2, 0.56 ± 0.01 for Hdac3, 0.01 ± 0.002 for Sirt1, and 0.84 ± 0.04 for Sirt2; P < 0.05). At the MI stage, however, there was no difference in the expression of Hdac3 between the two groups of oocytes (0.96 ± 0.03; P > 0.05). Taken together, diabetes altered the intracellular histone modification system, which may have contributed to changes in histone acetylation, and may be involved in the compromised maturation rate of oocytes in diabetic humans.

Subclinical endothelial dysfunction and low-grade inflammation play roles in the development of erectile dysfunction in young men with low risk of coronary heart disease

The purpose of this study is to investigate the possible underlying pathogenesis of erectile dysfunction(ED) in young men with low risk of coronary heart disease and no well-known aetiology. To conduct this study, 122 patients with ED under the age of 40 were enrolled, along with 33 age-matched normal control subjects. The patients with ED had significantly higher levels of systolic blood pressure (SBP), total cholesterol and triglyceride, high sensitivity C-reactive protein (hs-CRP), greater carotid intima-media thickness (CIMT) and Framingham risk score (FRS) than the control group, though all of these values were within the respective normal range. Further, the brachial artery flow- mediated vasodilation (FMD) values were significantly lower in ED patients and correlated positively with the severity of ED (r = 0.714, p < 0.001). When these significant factors were studied in the multivariate logistic regression model, FMD, SBP, hs-CRP and FRS remained the statistical significance. The receiver-operating characteristic (ROC) analysis demonstrated that FMD had a high ability to predict ED in young male with low FRS [area under the curve (AUC) 0.921, p < 0.001]. The cutoff value of FMD <10.25% had sensitivity of 82.8% and specificity of 100% for diagnosis of ED. FRS and hs- CRP were also proven to be predictors of ED (AUC 0.812, p < 0.001; AUC 0.645, p = 0.011, respectively). The results of this study validated that subclinical endothelial dysfunction and low-grade inflammation may be the underlying pathogenesis of ED with no well-known aetiology. Young patients complaining of ED should be screened for cardiovascular risk factors and possible subclinical atherosclerosis. Measurement of FMD, hs-CRP and FRS can improve our ability to predict and treat ED, as well as subclinical cardiovascular disease early for young male.