Varespladib mitigates acute liver injury via suppression of excessive mitophagy on Naja atra envenomed mice by inhibiting PLA2

Snakebite envenomation often leads to severe visceral injuries, including acute liver injury (ALI). However, the toxicity mechanism remains unclear. Moreover, varespladib can directly inhibit phospholipase A2 (PLA2) in snake venom, but its protective effect on snakebite-induced ALI and the mechanism have not been clarified. Previous studies have shown that snake venom PLA2 leads to neuron cell death via reactive oxygen species (ROS), one of the initial factors related to the mitophagy pathway. The present study group also found that ROS accumulation occurred after Naja atra envenoming. Hematoxylin and eosin (H/E) staining and immunohistochemistry (IHC) were performed to identify the expression of inflammatory factors in the liver tissue, and flow cytometry and immunofluorescence were used to detect ROS levels and mitochondrial function. Immunofluorescence and western blotting were also used for detecting mitophagy pathway-related proteins. The results showed that N. atra bite induced ALI by activating mitophagy and inducing inflammation and that varespladib had a protective effect. Collectively, these results showed the pathological mechanism of ALI caused by N. atra bite and revealed the protective effect of varespladib.

Effect of MTA3 Inhibition of Glutamine Synthetase-Mediated Glutaminolysis on Radiosensitivity of Patients with Esophageal Cancer

PURPOSE/OBJECTIVE(S)

Metastasis-associated protein 3 (MTA3) can serve as a tumor suppressor in many cancer types. However, the role of MTA3 in radiosensitivity of patients with esophageal squamous cell cancer (ESCC) remains unclear. We thus investigated the function of MTA3 in radiosensitivity for ESCC, one of the most common digestive cancers.

MATERIALS/METHODS

The colony formation assay and nude mice xenograft tumor assay were performed to investigate the effect of MTA3 on radiosensitivity in ESCC. Glutamine consumption assay kit and glutamate production assay kit were used to assess the glutaminolysis. Glutaminase (GLS) Activity Assay Kit and Glutamine Synthetase (GS) Activity Assay Kit were used to analyze the activity of specific metabolic enzymes dominate glutaminolysis. The regulatory mechanism of glutaminolysis by MTA3 was confirmed using Chromatin immunoprecipitation assay and Gaussia luciferase assay. The expression levels of MTA3 and GS in ESCC primary tissues were evaluated using immunohistochemistry. Survival curves were plotted with the Kaplan-Meier method and compared by log-rank test.

RESULTS

The colony formation assay showed that MTA3 depletion and overexpression caused significantly higher and lower clonogenic survival after different doses of irradiation (IR), respectively. When these cells were subcutaneously injected into nude mice, the tumors derived from the cells with MTA3 overexpression and MTA3 knockdown were significantly smaller and bigger after IR, respectively. These findings suggest that MTA3 can enhance radiosensitivity in vitro and in vivo. Meanwhile, overexpressed and knockdown MTA3 can repress and expedite glutamine consumption and glutamate production uniformly, respectively. To determine how MTA3 acts on glutaminolysis, the activity of two specific metabolic enzymes dominate this metabolism, GS and GLS, were evaluated. It found that overexpressed and knockdown MTA3 can restrain and enhance the activity of GS, respectively, but have less effect on GLS. Moreover, the decreased radiosensitivity mediated by MTA3 knockdown is significantly increased when treated with GS inhibitor, suggesting that GS plays a crucial role in MTA3-mediated radiosensitivity enhancement. Mechanistically, Chromatin immunoprecipitation assay and Gaussia luciferase assay showed that MTA3 was recruited to the promoter of GS and suppressed GS transcription. However, knockdown of GATA3 abolished MTA3's repressive effect on GS and inhibited the MTA3's occupation on the promoter region of GS. These results collectively demonstrated that, in ESCC cells, MTA3 is recruited by GATA3 to inhibit GS expression, then ultimately represses glutaminolysis and enhances radiosensitivity. Finally, we showed that the ESCC patients in the MTA3low/GShigh group is significantly associated with shorter overall survival.

CONCLUSION

MTA3 is capable of enhancing radiosensitivity through downregulating GS and MTA3low/GShigh might be a potential prognostic factor for ESCC patients.

The Joint Effect of Body Mass Index and Serum Lipid Levels on Incident Dementia among Community-Dwelling Older Adults

OBJECTIVES

This study aimed to explore the joint effect of body mass index (BMI) and serum lipids levels on incident dementia.

METHODS

We prospectively followed up with 1,627 dementia-free community residents aged ≥60 for 5.7 years on average. At baseline, weight, and height were measured, and total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were detected in serum. Demographic characteristics were collected through questionnaires. Dementia was based on consensus diagnosis of neurologists and neuropsychologists using DSM-IV criteria. Additive Cox proportional model was used to assess the exposure-response relationship between BMI and serum lipid levels and dementia risk. Interactions and further classifications of BMI and serum lipid levels were further presented by bivariate surface models and decision-tree models.

RESULTS

The joint effects of TC with BMI, TG with BMI, and LDL-C with BMI on the risk of incident dementia shared a similar pattern, different from their independent exposure-response curves. The joint effect of HDL-C with BMI showed an S-surface but without statistical significance. Participants with TC<5.4 mmol/L and BMI<21 kg/m2 (Hazard Ratio(HR) 1.93, 95% Confidence Interval (CI) 1.05-3.53), TC<5.4 mmol/L and BMI≥21 kg/m2 (HR 1.73, 95% CI 1.09-2.72), and TC≥5.4 mmol/L and BMI<21 kg/m2 (HR 4.02, 95% CI 2.10-7.71) were identified to have the increased risk of incident dementia compared to those with TC≥5.4 mmol/L and BMI≥21 kg/m2. Participants with TG<1.7 mmol/L and BMI<21 kg/m2 had an increased risk of incident dementia compared to those with TG≥1.7 mmol/L and BMI≥21 kg/m2 (HR 1.98, 95%CI 1.17-3.3). Participants with LDL-C≥3.3 mmol/L and BMI<21 kg/m2 were identified to have an increased risk of incident dementia compared to those with LDL-C≥3.3 mmol/L and BMI≥21 kg/m2 (HR 3.33, 95%CI 1.64-6.78).

CONCLUSIONS

Our study showed that low BMI combined with low or high levels of serum lipids may increase the risk of dementia among older adults. This finding suggests the potential impacts of these two metabolic indexes on the risk of dementia.

[Evaluation on applicationof virtual reality technology in dental implant process training]

Objective: To explore the application effect and evaluation of virtual reality technology in oral implant therapy training. Methods: In November 2018, one adult patient (female, 36 years old) with missing right mandibular first molar was treated in the Department of Implantology, School and Hospital of Stomatology, Fujian Medical University. The three-dimensional virtual models of mandible and implant surgery tools were established, and the virtual reality software (Unity 3D 5.5.1) was imported. Combined with the virtual reality head mounted display, a virtual reality training system simulating the dental implant treatment process was independently developed. Ten refresher doctors and 20 graduate students in Department of Implantology, School and Hospital of Stomatology, Fujian Medical University from September 2018 to December 2019 were recruited as the experimental objects (no clinical experience was found). According to the level and seniority of doctors, they were randomly divided into virtual training group and conventional training control group, which made the two groups comparable, with 15 in each group. Subjective scores (including anatomical structure, surgical field of vision, cavity preparation, implant placement and process mastery) were given after the corresponding training in the two groups, and the virtual reality training system was used to test. The mesial and distal direction, buccolingual direction, depth and angle deviation of implants before and after the training were analyzed, and the differences between the two groups were compared. Results: The subjective scores of five dimensions in the virtual training group were significantly higher than those in the conventional training control group (P<0.05). In the virtual training group, the mesial and distal, buccolingual, depth and angle deviation of implants were (0.73±0.33), (0.78±0.41), (0.61±0.32) mm and 6.66°±3.87°. All of them were significantly lower than those in the control group [(0.85±0.32), (1.12±0.38), (0.89±0.24) mm and 9.68°±3.74°] (P<0.05). Conclusions: The self-developed virtual reality system of oral implant has good application effect, good operability and predictability. It can be effectively carried out in implant education and training, and it can strengthen skills of doctors, and is conducive to the practical operation.

[Treatment de-intensification strategies for HPV-driven oropharyngeal cancer: A short review]

The incidence of oropharyngeal cancer induced by human papillomavirus (HPV) infection is steadily increasing in developed countries. These tumors are more chemoradiosensitive and have a better prognosis than HPV-negative one. In addition, they occur in younger and better-off patients with longer life expectancy. Current radiotherapy and chemotherapy protocols are currently being questioned as they may expose HPV-positive patients to excessive treatment and unnecessary toxic effects. Less intensive treatment regimens could possibly achieve similar efficacy with lower toxicity and improved quality of life. The aim of this work was to summarize the knowledge on these tumors and their implications for radiation oncologists. In this update, we will discuss ongoing de-escalation trials and highlight the issues raised by these studies. We will also comment on the results of recently published de-intensification studies. Three main strategies are analyzed in the present article: the de-escalation of the drug associated with radiotherapy, the de-escalation of the radiotherapy dose (in concomitant chemoradiotherapy, after induction chemotherapy, in a postoperative setting) and de-escalation of radiation target volumes. Our findings ultimately indicate that clinicians should not change the management of oropharyngeal cancer patients outside of clinical trials.

[Dynamic detection of surface blood flow in rat heart and its application in real time identification of myocardial infarction model]

Objective: To establish a method for monitoring the surface blood flow in the heart of rats, and to clarify the relationship between the degree of myocardial infarction and the blood perfusion on the surface of the heart, so as to provide a new indicator for the identification of rat myocardial infarction model. Methods: The rats were divided into control group (n=23) and model group (n=107), the rat hearts were scanned by the laser doppler perfusion imager before and after operation respectively, and the data was analyzed to acquire the rate of surface blood flow change of the heart. Myocardial infarction size of model group was detected by NBT. Model group were divided into three subgroups of mild myocardial infarction, moderate myocardial infarction and severe myocardial infarction according to the myocardial infarction size, and an analysis was made on the correlativity between rate of surface blood flow change of the heart and myocardial infarction size. Results: Myocardial infarction size was highly correlated to the rate of surface blood flow change of the heart in model group (r=0.849 6, P<0.000 1). There was no significant correlation between infarction size and heart blood flow in the mild myocardial infarction subgroup (r=-0.133 6, P>0.05), while the correlation in moderate myocardial infarction was significant (r=0.721 7, P<0.000 1), and the highest correlation was shown in severe myocardial infarction subgroup (r=0.910 2, P<0.000 1). Conclusion: The heart surface blood flow has a close relationship with the myocardial infarction size in rat, so the change of heart blood perfusion can beused as an effective reference to establish and identify rat myocardial infarction model.

[Research of the Epworth sleepiness scale based on ruzzy comprehensive evaluation]

Objective:This research explores the effect of Epworth sleepiness scale (ESS) items on domestic patients. Method:Four thousand six hundred and thirty-three suspected OSAHS patients with snoring were selected from respiratory sleep center in the first people's hospital, Yunnan province, between January 2006 and December 2012. These patients filled in the ESS before PSG test. Firstly, these questionnaires were preprocessed, and the null and incorrect ones were deleted. Then, the fuzzy comprehensive evaluation was applied for the value of each item in ESS. Finally, the reliability was compared between before and after the removal of the lowest values.Result:Fuzzy comprehensive evaluation results show that the total value is 1.016, the item value of Sitting and talking to someone and In a car, while stopped for a few minutes in traffic is the lowest, which is 0.131. The result of reliability analysis shows that the value increases 0.2% after the two items being deleted.Conclusion:Some items of ESS are not suitable for Chinese patients, and they need to be deleted or modified to improve the screening efficiency.

[Relationship between reproductive history and preterm births in the last pregnancy, in Shaanxi province]

Objective: To analyze the incidence of preterm delivery among single live neonates and the association between maternal reproductive history and preterm birth. Methods: A questionnaire survey was conducted on reproductive history among women at childbearing age who were selected through multi-stage stratified random sampling method in Shaanxi, during 2010-2013. Samples would include women at childbearing age and in pregnancy or having had definite pregnancy outcomes. Results: A total of 29 608 women at childbearing age with their infants, were studied. The overall incidence of premature delivery among the single live birth neonates under this study, was 2.7% during 2010-2013. Results from the logistic regression model showed that factors as: having had history with preterm delivery (OR=7.99, 95%CI: 5.59-11.43), age of the mothers, older than 35 (OR= 2.03, 95% CI: 1.59-2.59) and with history of birth defects (OR=1.54, 95% CI: 1.01-2.34) were at higher risks for premature delivery in neonates. Intervals on pregnancies between 3-4 years (compared with ≤2 years, OR=0.74, 95% CI: 0.58-0.93), between 5-6 years (compared with ≤2 years, OR=0.66, 95%CI: 0.52-0.82), or> 6 years (compared with ≤2 years, OR=0.48, 95%CI:0.37-0.61) together with numbers of parity as 1 (compared with primiparas, OR=0.80, 95%CI: 0.67-0.95), as ≥2 (compared with primiparas, OR=0.62, 95% CI: 0.39-0.97) etc. were protective factors to preterm delivery. Factors as: history of preterm delivery, mothers age (older than 35 years) and intervals of pregnancy, appeared influential to the age of gestation, under the ordinal polytomous logistic regression analysis. Conclusion: The incidence of preterm births among single live birth neonates in Shaanxi was lower than the average national level. Programs related to health care services prior to conception and during pregnancy, together with increasing the self-care consciousness of childbearing aged women etc, should all be strengthened in order to reduce the occurrence of preterm birth, in Shaanxi province.

A317491 relieved HIV gp120-associated neuropathic pain involved in P2X3 receptor in dorsal root ganglia

Glycoprotein 120 (gp120) is an HIV envelope glycoprotein. Gp120 can directly stimulate the primary sensory afferent neurons and cause hyperalgesia. The P2X₃ receptor in dorsal root ganglia (DRG) is involved in the transmission of pain. In this study, we aimed to explore the role of the P2X₃ receptor in gp120-induced neuropathic pain. Our data showed that mechanical and thermal hyperalgesia in rats treated with gp120 were increased compared to those in the control group. The expression levels of the P2X₃ mRNA and protein in rats treated with gp120 were higher than those in the control group. The P2X₃ antagonist A317491 decreased mechanical hyperalgesia and thermal hyperalgesia and the up-regulated expression levels of P2X₃ mRNA and protein in rats treated with gp120. A317491 decreased ERK1/2 phosphorylation levels in the gp120-treated rat DRG. In addition, P2X₃ agonist α,β-methylene ATP (α,β-meATP)-activated currents in DRG neurons cultured with gp120 were higher than those in control neurons. The inhibitory effect of A317491 on α,βme-ATP-induced currents in DRG neurons from the gp120-treated neurons was larger than that for control neurons. Molecular docking data showed that A317491 may be acted in the gp120 protein to inhibit the gp120 initiated the P2X₃ activation, decrease the sensitizing DRG primary afferents and reduce the signal transmission of neuropathic pain in gp120-treated rats. Therefore, the inhibition of the P2X₃ receptor in rat DRG neurons relieved gp120-induced mechanical hyperalgesia.

[Factors related to the influence on congenital malformation of body surface in Shaanxi province]

Objective: To investigate the influencing factors on congenital malformation of body surface. Methods: Multi-stage stratified random sampling method was adopted. A questionnaire survey was conducted among the childbearing aged women who experienced more than 28 weeks pregnancy or having definite pregnancy outcomes in Shaanxi, during 2010-2013. Results: Results from the logistic regression model showed that factors as: intrahepatic cholestasis of pregnancy (OR=21.76, 95%CI: 4.46-106.25), histories with abnormal pregnancy or reproduction (OR=11.88, 95%CI: 9.14-15.45), having birth defects in the family (OR=6.15, 95%CI: 2.66-14.23), being twins (OR=5.74, 95% CI: 3.34-9.86), being worker (compared with others, OR=2.47, 95% CI: 1.30-4.68) or farmer (compared with others, OR=1.91, 95%CI: 1.14-3.20), less than 4 times of antenatal care (compared with >7, OR=1.84, 95% CI: 1.28-2.64), occupational exposure to related risks during pregnancy (OR=1.74, 95% CI: 1.26-2.42), mother's hometown was from mid-part of Shaanxi (compared with northern Shaanxi, OR=1.65, 95%CI: 1.20-2.28), mother's native residence was from the rural areas (OR=1.75, 95% CI: 1.13-2.71), drug use (OR=1.64, 95% CI: 1.26-2.13) etc. were risk factors for congenital malformation of body surface. Iron supplement during pregnancy (OR=0.46, 95%CI: 0.21-0.99) appeared as protective factor for congenital malformation of body surface. Conclusion: The following factors seemed to be of risk for congenital malformation of body surface, including: mother's native area was from the middle part of Shaanxi and living in rural area, being worker or farmer, histories of abnormal pregnancy and reproduction, history of birth defects in the family, being twins, with antenatal care less than 4 times, occupational exposure to dangerous materials, drug use, intrahepatic cholestasis during pregnancy etc.

[The relevance between obstructive sleep apnea hypopnea syndrome andchronic obstructive pulmonary disease in China: A Meta-analysis]

Objective:To assess the correlation between obstructive sleep apnea hypopnea syndrome(OSAHS) and chronic obstructive pulmonary disease(COPD).Method: Databases such as Chinese Biomedical Literature Database, PubMed, Chinese Academic Journals full-text database, Wanfang Resource Database and Chongqing VIP have been searched to collect literatures about the relationship between OSAHS and COPD. The literature in conference proceedings and certain unpublished articles were also manually retrieved. RCT conformed to the condition was evaluated according to the standards of literature assessment, and the data has been extracted. The RevMan5.3 software was applied to carry out the same Metaanalysis.Result: Totally 19 articles were included, and Metaanalysis reveal that overlap syndrome(OS) patient's apnea hypopnea index is significantly higher than those of OSAHS patients［WMD=7.56, 95%CI（4.19,10.94）, P<0.01］; The LSaO₂ of OS patients is significantly lower than OSAHS patients［WMD=-10.50, 95%CI(-11.58, -6.08),P<0.01］; OS patients' FEV₁/FVC is significantly lower than COPD patients［WMD=4.65,95%CI（1.15,8.15）,P<0.01］.The results revealed that subgroup analysis according to the sample volume, age, body mass index(BMI) and FEV₁/FVC between OS patients and OSAHS patients has heterogeneity, but when analysis with the score of ESS the heterogeneity does not exist. Further, the subgroup analysis according to the sample volume, BMI, AHI,LSaO₂ and the time of Oxygen is lower than 90%(T90) those index between OS patients and COPD patients has heterogeneity, and the heterogeneity does not exist when subgroup is analyses with neck circumference. The funnel schema was nearly symmetry with little bias.Conclusion:The experimental results indicate that OSAHS is significantly related with COPD, and they may be the mutual risk factor for each other..

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.

Microwave dielectric characterisation of 3D-printed BaTiO3/ABS polymer composites

3D printing is used extensively in product prototyping and continues to emerge as a viable option for the direct manufacture of final parts. It is known that dielectric materials with relatively high real permittivity—which are required in important technology sectors such as electronics and communications—may be 3D printed using a variety of techniques. Among these, the fused deposition of polymer composites is particularly straightforward but the range of dielectric permittivities available through commercial feedstock materials is limited. Here we report on the fabrication of a series of composites composed of various loadings of BaTiO₃ microparticles in the polymer acrylonitrile butadiene styrene (ABS), which may be used with a commercial desktop 3D printer to produce printed parts containing user-defined regions with high permittivity. The microwave dielectric properties of printed parts with BaTiO₃ loadings up to 70 wt% were characterised using a 15 GHz split post dielectric resonator and had real relative permittivities in the range 2.6–8.7 and loss tangents in the range 0.005–0.027. Permittivities were reproducible over the entire process, and matched those of bulk unprinted materials, to within ~1%, suggesting that the technique may be employed as a viable manufacturing process for dielectric composites.

Small heat shock proteins and the endoplasmic reticulum: potential attractive therapeutic targets?

The endoplasmic reticulum(ER) is crucial for protein and lipid synthesis, folding and cellular homeostasis. Function impairment of ER would induce ER stress, which might play an important role in many different pathological states. Small heat shock proteins (sHsps) are known to be widely expressed throughout many tissues. SHsps are found to regulate many different pathological and pathophysiological processes and they are supposed to be potential therapeutic targets. Recent studies indicate that multiple sHsps localize to the mammalian and plant ER and sHsps confer protection against ER stress in multiple cellular processes. The mechanisms responsible for the cytoprotective effects of sHsps are related to maintaining ER homeostasis. Improved understanding of sHsps-related cytoprotective action on ER and successful strategies which could specifically target components of ER stress signalling responses amelioration of their toxic effects by sHsps is of great importance in the development of therapeutic approach for the disorders induced by dysfunction of ER.

Manufacture of electrical and magnetic graded and anisotropic materials for novel manipulations of microwaves

Spatial transformations (ST) provide a design framework to generate a required spatial distribution of electrical and magnetic properties of materials to effect manipulations of electromagnetic waves. To obtain the electromagnetic properties required by these designs, the most common materials approach has involved periodic arrays of metal-containing subwavelength elements. While aspects of ST theory have been confirmed using these structures, they are often disadvantaged by narrowband operation, high losses and difficulties in implementation. An all-dielectric approach involves weaker interactions with applied fields, but may offer more flexibility for practical implementation. This paper investigates manufacturing approaches to produce composite materials that may be conveniently arranged spatially, according to ST-based designs. A key aim is to highlight the limitations and possibilities of various manufacturing approaches, to constrain designs to those that may be achievable. The article focuses on polymer-based nano- and microcomposites in which interactions with microwaves are achieved by loading the polymers with high-permittivity and high-permeability particles, and manufacturing approaches based on spray deposition, extrusion, casting and additive manufacture.

Statins in nervous system-associated diseases: angels or devils?

Statins are commonly prescribed lipid-lowering medications that significantly reduce the risk of cardiovascular events. In addition to their ability to lower cholesterol by affecting the rate-limiting step in cholesterol biosynthesis, statins also have anti-inflammatory, immunomodulatory, antioxidant, antiapoptotic, and antiplatelet effects. Because of these pleiotropic abilities, statins may have some beneficial effects on neurologic diseases, including cerebrovascular disease, neurodegenerative disease, multiple sclerosis, and brain tumors. Although statins are a well-tolerated class of drugs, they also have potential adverse effects (AEs). A growing body of evidence indicates that statins may have potential negative effects on nervous system-associated diseases, including myopathies, peripheral neuropathy, intracerebral hemorrhage (ICH), and other diseases of the central nervous system (e.g., cognitive impairment, depression, sleep disorders, nightmare, and headache). Clinicians, especially neurologists, should be aware of the potential risk of neuropathy in patients who take statins.

Effect of moisture, lipids, and select amino acid blocking agents on the formation and stability of metastable radicals in powdered soy proteins

Incremental increases in the moisture content of powdered soy protein products from 4.4% to 13.4% produced an inverse effect on the ability of soy proteins to maintain metastable free radicals. The corresponding reduction in electron paramagnetic resonance signal was not due to dielectric loss in the range of moisture contents examined. Subsequent evaluations of various treatments were conducted after drying soy proteins with molecular sieve to a water activity below 0.085 in order to minimize the influence from variations in moisture. Isolated soy protein (ISP) samples, prepared with "defatted flour" that had been further extracted with chloroform/methanol (2: 1), had a 96% reduction in total lipids compared to the control ISP samples. The initial rate of radical accumulation in the "reduced-lipid" ISP for the first 3 wk was not significantly different from the initial rate of radical increases in the control ISP. After 3 wk, radical accumulation in the "reduced-lipid" ISP continued to increase, but at a rate that was less than the control. These findings indicate that the initial reactions contributing to the formation of metastable radicals in the powdered ISP are not strongly dependent on associated lipids. Blocking sulfhydryl groups during ISP preparation with N-ethylmaleimide did not significantly slow the rate of radical accumulation compared to the control ISP. Blocking arginine residues in ISP samples with phenylglyoxal caused an increased rate of radical accumulation for the first 4 wk.

PRACTICAL APPLICATION

Levels of metastable radicals in powdered soy protein products typically range from 10 to 100 times greater than the free radicals in other food protein sources. This current research examines various compositional and treatment parameters that might be used to minimize the content of free radicals in foods containing soy proteins.

Carbon-centered radicals in isolated soy proteins

Solid-state electron paramagnetic resonance (EPR) spectroscopy of commercial samples of isolated soy proteins (ISP) revealed a symmetrical free-radical signal typical of carbon-centered radicals (g= 2.005) ranging from 2.96 x 10(14) to 6.42 x 10(14) spins/g. The level of free radicals in ISP was 14 times greater than similar radicals in sodium caseinate, 29 times greater than egg albumin, and about 100 times greater levels than casein. Nine soy protein powdered drink mixes contained similar types of free radicals up to 4.10 x 10(15) spins/g of drink mix, or up to 6.4 times greater than the highest free-radical content found in commercial ISP. ISP samples prepared in the laboratory contained trapped radicals similar to the levels in commercial ISP samples. When ISP was hydrated in 2.3 mM sodium erythorbate or 8.3 mM L-cysteine, frozen and dried, the level of trapped free radicals increased by about 17- and 19-fold, respectively. The ESR spectrum of defatted soybean flakes contained overlapping signals from the primary free-radical peak (g= 2.005) and a sextet pattern typical of manganese-II. The manganese signal was reduced in the laboratory ISP and very weak in the commercial ISP.

Wetting, mixing, and phase transitions in Langmuir-Gibbs films

Millimolar bulk concentrations of the surfactant cetyltrimethylammonium bromide (CTAB) induce spreading of alkanes, H(CH(2))(n)H (denoted C(n)) 12< or =n< or =21, on the water surface, which is not otherwise wet by these alkanes. The novel Langmuir-Gibbs film (LGF) formed is a liquidlike monolayer comprising both alkanes and CTAB tails. Upon cooling, an ordering transition occurs, yielding a hexagonally packed, quasi-2D crystal. For 11< or =n< or =17 this surface-frozen LGF is a crystalline monolayer. For 18< or =n< or =21 the LGF is a bilayer with a crystalline, pure-alkane, upper monolayer, and a liquidlike lower monolayer. The phase diagram and film structure were determined by x-ray, ellipsometry, and surface tension measurements. A thermodynamic theory accounts quantitatively for the observations.

Reactivity of hydroxybenzoic acids in the hydrogen-isotope exchange reaction

The hydrogen-isotope exchange reaction (T-for-H exchange reaction) between tritiated water vapor (HTO vapor) and 3-hydroxy-4-methoxybenzoic acid (and it's analog; 4-hydroxy-3-methoxybenzoic acid) were observed at 50 and 70 degrees C in a gas-solid system to reveal the reactivity of a functional group in an aromatic compound having two substituents in the aromatic ring. Further, it was shown that (a) the reactivity of the compounds used in this work follows the Hammett's rule, and (b) the reactivity of trisubstituted aromatic compound could be analyzed by applying the additive property of the Hammett's rule even if the compound contains a substituent at the ortho-position.

A simple route to ultra long SiC nanowires

SiC nanowires are prepared by pyrolysis of hexamethyldisilane (HMDS), at 1200 degrees C in a flowing Ar atmosphere. The length of the nanowires is in millimeter scale. Transmission electron microscopy observations indicate that the diameters of the SiC nanowires are in the range of about 8 to 120 nm, and that most of the nanowires have numerous stacking faults. The formation mechanism of the nanowires is proposed.

Uteroplacental insufficiency affects epigenetic determinants of chromatin structure in brains of neonatal and juvenile IUGR rats

Intrauterine growth retardation (IUGR) increases the risk of neuroendocrine reprogramming. In the rat, IUGR leads to persistent changes in cerebral mRNA levels. This suggests lasting alterations in IUGR cerebral transcriptional regulation, which may result from changes in chromatin structure. Candidate nutritional triggers for these changes include altered cerebral zinc and one-carbon metabolite levels. We hypothesized that IUGR affects cerebral chromatin structure in neonatal and postnatal rat brains. Rats were rendered IUGR by bilateral uterine artery ligation; controls (Con) underwent sham surgery. At day of life 0 (d0), we measured cerebral DNA methylation, histone acetylation, expression of chromatin-affecting enzymes, and cerebral levels of one-carbon metabolites and zinc. At day of life 21 (d21), we measured cerebral DNA methylation and histone acetylation, as well as the caloric content of Con and IUGR rat breast milk. At d0, IUGR significantly decreased genome-wide and CpG island methylation, as well as increased histone 3 lysine 9 (H3/K9) and histone 3 lysine 14 (H3/K14) acetylation in the hippocampus and periventricular white matter, respectively. IUGR also decreased expression of the chromatin-affecting enzymes DNA methyltransferase 1 (DNMT1), methyl-CpG binding protein 2 (MeCP2), and histone deacetylase (HDAC)1 in association with increased cerebral levels of zinc. In d21 female IUGR rats, cerebral CpG DNA methylation remained lower, whereas H3/K9 and H3/K14 hyperacetylation persisted in hippocampus and white matter, respectively. In d21 male rats, IUGR decreased acetylation of H3/K9 and H3/K14 in these respective regions compared with controls. Despite these differences, caloric, fat, and protein content were similar in breast milk from Con and IUGR dams. We conclude that IUGR results in postnatal changes in cerebral chromatin structure and that these changes are sex specific.

Ultra long SiC/SiO2 core-shell nanocables from organic precursor

Ultra long SiC core and SiO2 shell nanocables have been prepared by pyrolysis of poly(dimethyl siloxane) at 1050 degrees C in flowing Argon. The longest nanocable can be up to at least 6 mm. Transmission electron microscopy observations indicate that the diameter of the cores varies from about 3 to 18 nm, and the thickness of the outer sheaths varies from about 6 to 45 nm and that the cores are crystalline and the sheaths are amorphous. The growth of the nanocables may be governed by a chemical vapor solid process. The nanocables exhibit good photoluminescence property.

G beta association and effector interaction selectivities of the divergent G gamma subunit G gamma(13)

G gamma(13) is a divergent member of the G gamma subunit family considered to be a component of the gustducin G-protein heterotrimer involved in bitter and sweet taste reception in taste bud cells. G gamma(13) contains a C-terminal asparagine-proline-tryptophan (NPW) tripeptide, a hallmark of RGS protein G gamma-like (GGL) domains which dimerize exclusively with G beta(5) subunits. In this study, we investigated the functional range of G gamma(13) assembly with G beta subunits using multiple assays of G beta association and G beta gamma effector modulation. G gamma(13) was observed to associate with all five G beta subunits (G beta(1-5)) upon co-translation in vitro, as well as function with all five G beta subunits in the modulation of Kir3.1/3.4 (GIRK1/4) potassium and N-type (alpha(1B)) calcium channels. Multiple G beta/G gamma(13) pairings were also functional in cellular assays of phospholipase C (PLC) beta 2 activation and inhibition of G alpha(q)-stimulated PLC beta 1 activity. However, upon cellular co-expression of G gamma(13) with different G beta subunits, only G beta(1)/G gamma(13), G beta(3)/G gamma(13), and G beta(4)/G gamma(13) pairings were found to form stable dimers detectable by co-immunoprecipitation under high-detergent cell lysis conditions. Collectively, these data indicate that G gamma(13) forms functional G beta gamma dimers with a range of G beta subunits. Coupled with our detection of G gamma(13) mRNA in mouse and human brain and retina, these results imply that this divergent G gamma subunit can act in signal transduction pathways other than that dedicated to taste reception in sensory lingual tissue.

TASK-1 is a highly modulated pH-sensitive 'leak' K(+) channel expressed in brainstem respiratory neurons

Central respiratory chemoreceptors adjust respiratory drive in a homeostatic response to alterations in brain pH and/or P(CO(2)). Multiple brainstem sites are proposed as neural substrates for central chemoreception, but molecular substrates that underlie chemosensitivity in respiratory neurons have not been identified. In rat brainstem neurons expressing transcripts for TASK-1, a two-pore domain K(+) channel, we characterized K(+) currents with kinetic and voltage-dependent properties identical to cloned rat TASK-1 currents. Native currents were sensitive to acid and alkaline shifts in the same physiological pH range as TASK-1 (pK approximately 7.4), and native and cloned pH-sensitive currents were modulated similarly by neurotransmitters and inhalational anesthetics. This pH-sensitive TASK-1 channel is an attractive candidate to mediate chemoreception because it is functionally expressed in respiratory-related neurons, including airway motoneurons and putative chemoreceptor neurons of locus coeruleus (LC). Inhibition of TASK-1 channels by extracellular acidosis can depolarize and increase excitability in those cells, thereby contributing to chemoreceptor function in LC neurons and directly enhancing respiratory motoneuronal output.

Multiplication by eye and by ear for Chinese-speaking and English-speaking adults

English-speaking (n = 32) and Chinese-speaking adults (n = 32) solved single-digit multiplication problems. In one condition, problems were presented as visual digits (e.g., 8 x 9). In the other condition, problems were presented as auditory number words in the participant's first language (e.g., /eit/ /taimz/ /nain/). Chinese-speaking adults made proportionately more operand-intrusion errors (e.g., 4 x 8 = 24) than English-speaking adults. Both groups made more operand-intrusion errors with auditory than with visual presentation. These findings are similar to those found when participants solve problems presented as visual number words (e.g., eight x nine), suggesting that in both cases the activation of phonological codes interferes with processing.