Influence of environmental conditions on accumulated polyhydroxybutyrate in municipal activated sludge

Poly(3-hydroxybutyrate) (PHB) was accumulated in full-scale municipal waste activated sludge at pilot scale. After accumulation, the fate of the PHB-rich biomass was evaluated over two weeks as a function of initial pH (5.5, 7.0 and 10), and incubation temperature (25, 37 and 55°C), with or without aeration. PHB became consumed under aerobic conditions as expected with first order rate constants in the range of 0.19 to 0.55 d^-1. Under anaerobic conditions, up to 63 percent of the PHB became consumed within the first day (initial pH 7, 55°C). Subsequently, with continued anaerobic conditions, the polymer content remained stable in the biomass. Degradation rates were lower for acidic anaerobic incubation conditions at a lower temperature (25°C). Polymer thermal properties were measured in the dried PHB-rich biomass and for the polymer recovered by solvent extraction using dimethyl carbonate. PHB quality changes in dried biomass, indicated by differences in polymer melt enthalpy, correlated to differences in the extent of PHB extractability. Differences in the expressed PHB-in-biomass melt enthalpy that correlated to the polymer extractability suggested that yields of polymer recovery by extraction can be influenced by the state or quality of the polymer generated during downstream processing. Different post-accumulation process biomass management environments were found to influence the polymer quality and can also influence the extraction of non-polymer biomass. An acidic post-accumulation environment resulted in higher melt enthalpies in the biomass and, consequently, higher extraction efficiencies. Overall, acidic environmental conditions were found to be favourable for preserving both quantity and quality after PHB accumulation in activated sludge.

Yogurt Supplementation Attenuates Insulin Resistance in Obese Mice by Reducing Metabolic Endotoxemia and Inflammation

BACKGROUND

Inflammation is an underlying mechanism for the development of obesity-related health complications. Yogurt consumption inhibits obesity-associated inflammation, but the tissue-specific mechanisms have not been adequately described.

OBJECTIVES

We aimed to determine the tissue-specific responses by which yogurt supplementation inhibits inflammation.

METHODS

C57BL/6 male mice (5 wk old) were fed a Teklad Global 14% Protein Rodent Maintenance diet as a control or a high-fat diet (60% calories from fat) to induce obesity for 11 wk, followed by feeding a Western diet (WD; 43% carbohydrate and 42% fat) or WD supplemented with 5.6% lyophilized yogurt powder for 3 wk to test for the impact of yogurt supplementation. Markers of metabolic endotoxemia and inflammation were assessed in plasma and tissues. Cecal and fecal microbiota were profiled by 16S rRNA sequencing.

RESULTS

In obese mice, relative to the WD control group, yogurt supplementation attenuated HOMA-IR by 57% (P = 0.020), plasma TNF-α by 31% (P < 0.05) and colonic IFN-γ by 46% (P = 0.0034), which were accompanied by a 40% reduction in plasma LPS binding protein (LBP) (P = 0.0019) and 45% less colonic Lbp expression (P = 0.037), as well as alteration in the beta diversity of cecal microbiota (P = 0.0090) and relative abundance of certain cecal microbes (e.g., Lachnospiraceae Dorea longicatena with P = 0.049). There were no differences in the LBP, Lbp, and Cd14 levels in the liver and small intestine between obese mice with and without yogurt supplementation (P > 0.05).

CONCLUSIONS

Yogurt consumption inhibits obesity-induced inflammation in mice by modulating colonic endotoxin detoxification, changing the gut microbiota, and improving glucose metabolism. This work helps to establish the underlying mechanisms by which yogurt consumption affects markers of metabolic and immune health.

Neuroprotective Effects of IVIG against Alzheimer' s Disease via Regulation of Antigen Processing and Presentation by MHC Class I Molecules in 3xTg-AD Mice

BACKGROUND

The results of clinical trials for Alzheimer's disease (AD) patients treated with Intravenous immunoglobulin (IVIG) revealed inconsistency in efficacy.

OBJECTIVE

To explore the neuroprotective effects and possible mechanisms of different IVIG in 3xTg-AD mice.

METHODS

3-month-old 3xTg-AD mice were administered intraperitoneally with different IVIG (A/B/C) for 3 months and then the therapeutic effects were observed and tested at 9 months of age. The bioavailability of IVIG and Aβ40/42 concentrations in parietotemporal cortex was measured by ELISA. Behavioral tests were performed to examine cognitive functions. Immunohistochemistry was utilized to examine the deposition of Aβ, the phosphorylation of tau, the levels of GFAP and Iba-1 in the hippocampus. Proteomics, Luminex assay and parallel reaction monitoring were performed to identify and verify the proteins that showed a marked change in the hippocampus.

RESULTS

IVIG-C was more effective than IVIG-A and IVIG-B in counteracting cognitive deficits, ameliorating Aβ deposits and tau phosphorylation, attenuating the activation of microglia and astrocytes in the hippocampus and inhibiting the secretion of pro-inflammatory factors. IVIG-C affected innate immunity and suppressed the activation of antigen processing and presentation by MHC class I molecule (APP-MHC-I).

CONCLUSION

The efficacy of different IVIG on AD was significantly different, and only IVIG-C has been confirmed to possess significant neuroprotective effects, which are related to the inhibition of APP-MHC-I. IVIG may be a potential therapeutic for AD but further research is needed to evaluate the functional of IVIG before clinical trials of AD treatment.

Yogurt Supplementation Attenuated Insulin Resistance in Obese Mice by Reducing Systemic Markers of Metabolic Endotoxemia and Inflammation

Objectives

To understand the mechanisms by which yogurt attenuates insulin resistance and chronic inflammation in a diet-induced obesity model.

Methods

C57BL6 mice were fed either a chow diet (C) or a high-fat diet (HFD) (F) for 11 weeks to induce obesity. Mice were then randomized to receive either a western diet (WD) (CC or FC) or a yogurt-supplemented WD (CY or FY) for 3 weeks to evaluate the impact of yogurt consumption on markers of energy metabolism, metabolic endotoxemia, chronic inflammation, and the gut microbiota. Biological samples were collected at necropsy (Week 14): Plasma samples were used to assess glucose by colorimetric method, insulin and lipopolysaccharide-binding protein (LBP) levels by ELISA kits, and cytokine levels by a Meso Scale Discovery biomarker assay kit. Cecal samples were used to assess the microbiota by 16S rRNA sequencing.

Results

Female mice showed a mild increase in Homeostatic Model Assessment for Insulin Resistance (HOMA-IR; calculated from plasma glucose and insulin levels) in response to HFD. Among male mice, however, compared to CC and CY, FC had significantly higher HOMA-IR (p &lt; 0.05 for comparisons between CC-FC & CY-FC by ANOVA, followed by Tukey HSD as the post-hoc test), accompanied by significantly elevated plasma LBP, TNF-α, IL-10, and leptin levels (p &lt; 0.05 by ANOVA & Tukey HSD), as well as higher relative abundance of cecal bacteria, Dorea longicatena (p &lt; 0.05 by likelihood-ratio test), which was associated with elevated risks for metabolic syndrome and diabetes. In contrast, FY significantly attenuated HOMA-IR and plasma LBP, IL-10, TNF-α, and leptin levels compared to FC (p &lt; 0.05 by ANOVA & Tukey HSD). Also, beta-diversity of cecal microbiota from FY was significantly different from the rest of three groups (p &lt; 0.01 by Analysis of similarities), and the relative abundance of Dorea longicatena was significantly attenuated in FY than in FC (p &lt; 0.05 by likelihood-ratio test).

Conclusions

Yogurt supplementation attenuated HFD-induced insulin resistance while modulating the gut microbiota, markers of metabolic endotoxemia, and systemic inflammation. This study helps explain the specific mechanisms by which yogurt consumption modulates inflammation in obesity.

Funding Sources

National Dairy Council, University of Wisconsin Dairy Innovation Hub.

Faba bean protein: A promising plant-based emulsifier for improving physical and oxidative stabilities of oil-in-water emulsions

Faba bean is a protein-rich, sustainable, but understudied legume. Faba bean protein isolates (FBPIs) can serve as promising emulsifiers. This review aims to summarize the research on FBPIs as emulsifiers and various modification methods to improve the emulsifying functionalities. The emulsifying activities of FBPIs depend on several physiochemical characteristics (e.g. solubility, surface hydrophobicity, surface charge, interfacial activity). Physical modifications, especially via linking FBPIs electrostatically to polysaccharides can effectively increase the interfacial layer thickness/compactness and maintain the interfacial protein adsorption. Chemical modifications of FBPIs (e.g. acetylation and Maillard reaction) could improve the interfacial activity and affect the droplet-size distribution. Enzymatic modifications, usually either via hydrolysis or cross-linking, help to optimize the molecular size, solubility, and surface hydrophobicity of FBPIs. It is critical to consider the lipid/protein oxidative stability and physical stability when optimizing the emulsifying functionality of FBPIs. With suitable modifications, FBPI can serve as a promising emulsifier in food production.

Identifying a novel 5-gene signature predicting clinical outcomes in acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) is the most common type of acute leukemia and biologically heterogeneous diseases with poor prognosis. Thus, we aimed to identify prognostic markers to effectively predict the prognosis of AML patients and eventually guide treatment.

METHODS

Prognosis-associated genes were determined by Kaplan-Meier and multivariate analyses using the expression and clinical data of 173 AML patients from The Cancer Genome Atlas database and validated in an independent Oregon Health and Science University dataset. A prognostic risk score was computed based on a linear combination of 5-gene expression levels using the regression coefficients derived from the multivariate logistic regression model. The classification of AML was established by unsupervised hierarchical clustering of CALCRL, DOCK1, PLA2G4A, FCHO2 and LRCH4 expression levels.

RESULTS

High FCHO2 and LRCH4 expression was related to decreased mortality. While high CALCRL, DOCK1, PLA2G4A expression was associated with increased mortality. The risk score was predictive of increased mortality rate in AML patients. Hierarchical clustering analysis of the five genes discovered three clusters of AML patients. The cluster1 AML patients were associated with lower cytogenetics risk than cluster2 or 3 patients, and better prognosis than cluster3 patients (P values < 0.05 for all cases, fisher exact test or log-rank test).

CONCLUSION

The gene panel comprising CALCRL, DOCK1, PLA2G4A, FCHO2 and LRCH4 as well as the risk score may offer novel prognostic biomarkers and classification of AML patients to significantly improve outcome prediction.

Low-Fat Yogurt Consumption Modulates Insulin in Obese Mice

Objectives

The objective of this study was to determine how low-fat yogurt consumption affects obese mice fed on standardized western diet.

Methods

C57BL6 mice were acclimatized for 2 weeks prior to experiments. Mice were fed either a chow diet (C, Teklad global 2014C) or a standard high-fat diet (F, TD.06414, 60.3% kcal from fat) for 11 weeks to induce increased fat mass and obesity. Then, the mice were further randomized to receive either a typical western diet (FC and CC, TD.07201) or a yogurt-supplemented diets (FY and CY, 5.6% lyophilized yogurt) for 3 weeks to test how yogurt consumption inhibits markers of obesity. Body weight and food intake were recorded weekly. Adipose tissues and liver weights were also measured. Fasting plasma (for 4 hours) was collected to determine glucose and insulin level.

Results

After 11 weeks, the mean body weights of mice fed with C and F diets were 27.0 ± 0.7 and 37.4 ± 1.6 g, respectively (P &lt; 0.05). Consumption of the western diet rapidly induced weight gain in the chow-fed mice over the subsequent 3 weeks relative to obese mice due to increased food intake. Thus, at week 14, the groups had similar mean body weights ranging from 32.6 to 41.5 g. In mice initially fed with chow diet, yogurt intake reduced food consumption to levels intermediate to the CC and FY/CY groups. For the liver weight, no significant difference was found between FC and FY group. Retroperitoneal adipose tissue was increased by 62% in FC group compared to CC group (P &lt; 0.001), and yogurt did not affect tissue weights in either group. Fasting glucose levels were not significantly different between FC and FY. FC had increased fasting insulin at 2.49 ± 1.99 µg/L compared to CC (P &lt; 0.01), and was normalized by yogurt supplementation to 1.44 ± 1.14 µg/L in FY (P &lt; 0.05). Likewise, the HOMA-IR index was significantly increased in FC compared to CY (P &lt; 0.05), but not in FY.

Conclusions

Yogurt did not prevent the rapid weight gain in mice induced by a Western diet. In obese mice, yogurt effectively inhibited fasting hyperinsulemia as part of a Western diet.

Funding Sources

Supported by National Dairy Council.

Flavonoids and gut health

Flavonoids are dietary non-nutrient bioactives with antioxidant and anti-inflammatory properties. Fruits, vegetables, nuts, legumes, and tea are rich in flavonoids. After consumption, flavonoids are extensively metabolized by the gut microbiota and host tissues. Flavonoid metabolism exhibits extensive variation between individuals. It is plausible that inter-individual differences in flavonoid metabolism impact the immune system. Pre-clinical studies have characterized direct and indirect mechanisms by which flavonoids modulate intestinal immune function. This includes modulation of T cell differentiation, alteration of gut microbiota, and modulation of cytokines. Defining the importance of these mechanisms to human chronic disease will improve dietary recommendations for the anti-inflammatory uses of flavonoids.

A common antimicrobial additive increases colonic inflammation and colitis-associated colon tumorigenesis in mice

Triclosan (TCS) is a high-volume chemical used as an antimicrobial ingredient in more than 2000 consumer products, such as toothpaste, cosmetics, kitchenware, and toys. We report that brief exposure to TCS, at relatively low doses, causes low-grade colonic inflammation, increases colitis, and exacerbates colitis-associated colon cancer in mice. Exposure to TCS alters gut microbiota in mice, and its proinflammatory effect is attenuated in germ-free mice. In addition, TCS treatment increases activation of Toll-like receptor 4 (TLR4) signaling in vivo and fails to promote colitis in Tlr4^-/- mice. Together, our results demonstrate that this widely used antimicrobial ingredient could have adverse effects on colonic inflammation and associated colon tumorigenesis through modulation of the gut microbiota and TLR4 signaling. Together, these results highlight the need to reassess the effects of TCS on human health and potentially update policies regulating the use of this widely used antimicrobial.

Dietary Prevention of Colitis by Aronia Berry is Mediated Through Increased Th17 and Treg

SCOPE

Increased fruit consumption is associated with reduced risk of colitis. It has been investigated whether the anti-colitic effects of the polyphenol-rich aronia berry (Aronia mitschurinii 'Viking') are mediated through Th17 and Treg.

METHODS AND RESULTS

Colitis is induced in recombinase activating gene-1 deficient mice injected with syngeneic CD4⁺ CD62L⁺ naïve T cells. Mice consume either 4.5% w/w aronia-berry-supplemented or a control diet concurrent with T cell transfer. The extent of colitis and immunocyte populations are evaluated at weeks 3 to 7 after transfer. Aronia consumption prevents colitic wasting and reduces colon weight/length ratios relative to the control diet at weeks 5 and 7. Compared to the control diet, aronia feeding increases Treg in mesenteric lymph node at all colitis stages. Treg and regulatory Th17 subpopulations (IL-17A⁺ IL-10⁺ and IL-17A⁺ IL-22⁺ ) are increased in lamina propria and spleen at week 5 in aronia-fed mice. Aronia feeding also decreases total CD4⁺ cells but increases colonic Tregs. The ability of aronia to modulate colonic cytokines is associated with functional T cell IL-10 and increased diversity of microbiota.

CONCLUSIONS

Aronia berry consumption inhibits adoptive transfer colitis by increasing Treg and regulatory Th17 cells. Dietary modulation of T cells is dynamic and precedes colitic wasting.

Has_circ_0008274 promotes cell proliferation and invasion involving AMPK/mTOR signaling pathway in papillary thyroid carcinoma

OBJECTIVE

Circular RNAs (circRNAs) have been known as important regulators in tumorigenesis. Whether circRNAs are involved in papillary thyroid carcinoma (PTC) requires to be determined. In the present study, we aimed to investigate the expression and function of has_circ_0008274 in PTC.

PATIENTS AND METHODS

Tissue expression of has_circ_0008274 was evaluated in Gene Expression Omnibus datasets (GSE93522). Real-time PCR assays were used to detect the expression of has_circ_0008274 in human PTC tissues and cell lines. The correlation of has_circ_0008274 expression with clinicopathological factors was statistically analyzed. The MTT assay, colony formation assay, transwell assays were performed to analyze and compare cell viability and invasion. Western blot analysis was used to quantify the expression of AMPK/mTOR signaling pathway proteins.

RESULTS

We found that has_circ_0008274 was significantly upregulated in PTC tissues, and the level of has_circ_0008274 was negatively associated with TNM stage and lymph node metastasis. Loss-of-function assay indicated that knockdown of has_circ_0008274 suppressed PTC cells proliferation and invasion in vitro. Mechanistically, has_circ_0008274 could inhibit the activation of AMPK/mTOR signaling pathway, which was demonstrated by measuring the expression levels of p-AMPK and p-mTOR.

CONCLUSIONS

These results demonstrate that increased has_circ_0008274 expression modulates has_circ_0008274 to enhance PTC cells proliferation and invasion. Has_circ_0008274/ AMPK/mTOR axis may be a novel therapeutic candidate target in PTC treatment.

Yogurt inhibits intestinal barrier dysfunction in Caco-2 cells by increasing tight junctions

Chronic inflammation disrupts intestinal barrier function and may contribute to the pathology of obesity and other diseases. The goal of this study was to determine the mechanism by which yogurt improves intestinal barrier function. Caco-2 cells were differentiated on Transwell inserts and used as a model of intestinal barrier permeability. Transepithelial electrical resistance (TEER) and flux of 4 kDa fluorescein isothiocyanate-dextran (FD) and lucifer yellow (LY) were used as indicators of monolayer integrity and paracellular permeability. Immunofluorescence microscopy and real time quantitative polymerase chain were used to assess the localization and expression of tight junction proteins known to regulate intestinal permeability. Differentiated cells were treated with a vehicle control (C), inflammatory stimulus (I) (interleukin-1β, tumor necrosis factor-α, interferon-γ, and lipopolysaccharide), or I and 0.03 g mL^-1 yogurt (IY). After 48 h, I reduced Caco-2 TEER by 46%, while IY reduced TEER by only 27% (P < 0.0001). FD and LY flux reflected TEER measurements, with IY having significantly lower permeability than I (P < 0.05). Yogurt also improved localization of occludin and zona occludens protein 1 (ZO-1) at tight junctions of differentiated Caco-2 cells. IY increased Caco-2 claudin-1, ZO-1, and occludin mRNA relative to I (P < 0.05). In a simulated digestion, the barrier-improving bioactivity of yogurt was maintained through the gastric phase, but was reduced to the level of I after intestinal digestion (P < 0.05). Therefore, yogurt improved inflammation-disrupted intestinal barrier function in a Caco-2 model by increasing tight junctions, but the beneficial effect on barrier function was reduced at latter stages of digestion.

Premeal Low-Fat Yogurt Consumption Reduces Postprandial Inflammation and Markers of Endotoxin Exposure in Healthy Premenopausal Women in a Randomized Controlled Trial

Background

Metabolic endotoxemia is associated with obesity and contributes to postprandial inflammation.

Objective

We aimed to determine if low-fat yogurt consumption prevents postprandial inflammation and dysmetabolism in healthy women by inhibiting biomarkers of metabolic endotoxemia.

Methods

Premenopausal women defined as obese and nonobese [body mass index (BMI, in kg/m2) 30-40 and 18.5-27, respectively, n = 120] were randomly assigned to consume 339 g of low-fat yogurt (YN, yogurt nonobese; YO, yogurt obese) or 324 g of soy pudding (CN, control nonobese; CO, control obese) for 9 wk (n = 30/group). The intervention foods each supplied 330 kcal with 3 g fat, 66 g carbohydrate, and 4-6 g protein. At weeks 0 and 9, participants ingested 226 g of yogurt or 216 g of soy pudding before a meal providing 56-60 g fat, 82 g carbohydrate, and 28-30 g protein. Plasma soluble CD14 (sCD14), lipopolysaccharide-binding protein (LBP), LPS activity, interleukin-6 (IL-6), glucose, triglyceride, and insulin were measured hourly for 4 h to assess differences in postprandial responses between groups by 2-factor ANOVA.

Results

Premeal yogurt consumption prevented the postprandial decrease in sCD14 net incremental area under the curve (net iAUC) by 72% in obese individuals at week 0 (P = 0.0323). YN and YO had ≥40% lower net iAUC of LBP-to-sCD14 ratio and plasma IL-6 concentration than CN and CO, respectively (P < 0.05). CO had postprandial hyperglycemia which was not evident in YO; in contrast YN had 57% less postprandial hypoglycemia than did CN (P-interaction = 0.0013). After 9 wk of yogurt consumption, ΔAUC of LBP-to-sCD14 ratios of YO and YN were less than half of those of the control groups (P = 0.0093).

Conclusion

Yogurt consumption improved postprandial metabolism and biomarkers of metabolic endotoxemia in healthy premenopausal women. Premeal yogurt consumption is a feasible strategy to inhibit postprandial dysmetabolism and thus may reduce cardiometabolic risk. This trial was registered at clinicaltrials.gov as NCT01686204.

Fast anaerobic sludge granulation at elevated salinity

It is commonly accepted that high salt concentrations negatively affect microbial activity in biological wastewater treatment reactors such as upflow anaerobic sludge blanket (UASB) reactors. Microbial aggregation in such reactors is equally important. It is well documented that anaerobic granules, when exposed to high salinity become weak and disintegrate, causing wash-out, operational problems and decreasing process performance. In this research, the possibility of microbial granule formation from dispersed biomass was investigated at salinity levels of 5 and 20 g Na⁺/L. High removal efficiencies of soluble influent organics were achieved at both salinity levels and this was accompanied by fast and robust formation of microbial granules. The process was found to be stable for the entire operational period of 217 days. As far as we know this is the first time it has been demonstrated that stable granule formation is possible at a salinity level as high as 20 g Na⁺/L. Methanosaeta was identified as the dominant methanogen at both salinity levels. Streptococcus spp. and bacteria belonging to the family Lachnospiraceae were identified as the dominant microbial population at 5 and 20 and g Na⁺/L, respectively.

L-Tetrahydropalmatine Induces Apoptosis in EU-4 Leukemia Cells by Down-Regulating X-Linked Inhibitor of Apoptosis Protein and Increases the Sensitivity Towards Doxorubicin

BACKGROUND

L-Tetrahydropalmatine (L-THP) is a tetra-hydro protoberberine isoquinoline alkaloid. The phyto-compounds bearing isoquinoline alkaloids have been reported to show a potential effect against a number of human cancers cell lines including leukemia. We hypothesized that L-THP, being an isoquinoline alkaloid, could be a potential molecule against acute lymphoblastic leukemia (ALL), in this study, we evaluate L-THP against p53 deficient leukemia EU-4 cell lines in vitro.

METHODS

For the study, p53 null leukemia EU-4 cells were used and treated with LTHP. The extent of apoptosis and viability of cells were determined. Expression of apoptosis related proteins such as XIAP and MDM2 was done by western blot and PCR studies. The expression of MDM2 and XIAP was knocked down by small interfering RNA (siRNA).

RESULTS

Outcomes of the study suggested that L-THP caused p53-indipendent apoptosis mediated by XIAP in EU-4 cells. The treatment of L-THP caused a decrease in the levels of XIAP protein with increasing dose and time. L-THP caused down-regulation of XIAP protein via inhibiting the expression of MDM2 and involving proteasomedependent pathway. Also, the outcomes of experiments suggested increased sensitivity of leukemia cells towards doxorubicin due to the inhibition of XIAP by L-THP or by siRNA.

CONCLUSION

Findings of the study confirm that L-THP resulted in p53 independent apoptosis via down-regulating XIAP protein by inhibiting MDM2 associated with proteasome-dependent pathway and increased sensitivity of EU-4 cells against doxorubicin. L-THP caused activation of caspase and resulted in apoptosis, L-THP may be a novel molecule for inducing apoptosis specifically in p53 null leukemia EU-4 cells.

Integrated Microfluidic Aptasensor for Mass Spectrometric Detection of Vasopressin in Human Plasma Ultrafiltrate

We present a microfluidic aptamer-based biosensor for detection of low-molecular-weight biomarkers in patient samples. Using a microfluidic device that integrates aptamer-based specific analyte extraction, isocratic elution, and detection by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, we demonstrate rapid, sensitive and label-free detection of arginine vasopressin (AVP) in human plasma ultrafiltrate. AVP molecules in complex matrices are specifically captured by an aptamer that is immobilized on microbeads via affinity binding in a microchamber. After the removal of unbound, contaminating molecules through washing, aptamer-AVP complexes are thermally disrupted via on-chip temperature control. Released AVP molecules are eluted with purified water and transferred to a separate microchamber, and deposited onto a single spot on a MALDI plate via repeated, piezoelectrically actuated ejection, which enriches AVP molecules over the spot area. This integrated on-chip sample processing enables the quantitative detection of low-abundance AVP by MALDI-TOF mass spectrometry in a rapid and label-free manner. Our experimental results show the detection of AVP in human plasma ultrafiltrate as low as physiologically relevant picomolar concentrations via aptamer-based selective preconcentration, demonstrating the potential of our approach as a rapid (~ 1hr), sensitive clinical AVP assay.

α-Tocopherol supplementation reduces 5-nitro-γ-tocopherol accumulation by decreasing γ-tocopherol in young adult smokers

γ-Tocopherol (γ-T) scavenges reactive nitrogen species (RNS) to form 5-NO2-γ-T (NGT). However, α-T supplementation decreases circulating γ-T, which could limit its RNS scavenging activities. We hypothesized that α-T supplementation would mitigate NGT accumulation by impairing γ-T status. Healthy smokers (21 ± 1 y, n = 11) and non-smokers (21 ± 2 y, n = 10) ingested 75 mg/d each of RRR- and all-rac-α-tocopheryl acetate for 6 d. Plasma α-T, γ-T, γ-carboxyethyl hydroxychromanol (CEHC), NGT, and nitrate/nitrite were measured prior to supplementation (Pre), the morning after 6 consecutive evenings of supplementation (Post 1), and on the mornings of d 6 (Post 6) and d 14 (Post 14) during the post-supplementation period. α-T supplementation increased plasma α-T, and decreased γ-T, in both groups and these returned to Pre concentrations on Post 6 regardless of smoking status. Plasma γ-CEHC increased after the first dose of supplementation in both groups, suggesting that α-T supplementation decreased plasma γ-T in part by increasing its metabolism. Plasma NGT and nitrate/nitrite concentrations at Pre were greater in smokers, indicating greater nitrative stress due to cigarette smoking. Plasma NGT concentration was lowered only in smokers on Post 1 and Post 6 and was restored to Pre levels on Post 14. Plasma nitrate/nitrite tended (P = 0.07) to increase post-supplementation only in smokers, supporting decreases in RNS scavenging by γ-T. Plasma NGT concentration was more strongly correlated (P < 0.05) with γ-T in smokers (R = 0.83) compared with non-smokers (R = 0.50), supporting that α-T-mediated decreases in γ-T reduces NGT formation. These data indicate that α-T supplementation limits γ-T scavenging of RNS in smokers by decreasing γ-T availability.

Greater γ-tocopherol status during acute smoking abstinence with nicotine replacement therapy improved vascular endothelial function by decreasing 8-iso-15(S)-prostaglandin F2α

Nicotine replacement therapy (NRT) improves the long-term success rate of smoking cessation, but induces oxidative stress and inflammatory responses that may delay the restoration of vascular endothelial function (VEF). No studies have examined co-therapy of NRT-assisted smoking abstinence with γ-tocopherol (γ-T), a vitamin E form with antioxidant and anti-inflammatory activities, on improvements in VEF. In a randomized, double-blind, placebo-controlled study, healthy smokers (25 ± 1 y old; mean ± SEM) received NRT and abstained from smoking for 24 h with placebo (n = 12) or oral administration of γ-T-rich mixture of tocopherols (γ-TmT; n = 11) that provided 500 mg γ-T. Brachial artery flow-mediated dilation (FMD), and biomarkers of nitric oxide metabolism, antioxidant status, inflammation, and lipid peroxidation [8-iso-prostaglandin F2α stereoisomers (8-iso-15(R)-PGF2α and 8-iso-15(S)-PGF2α)] were measured prior to and after 24 h of smoking abstinence. Smoking abstinence with NRT regardless of γ-TmT similarly decreased urinary naphthol (P < 0.05) without affecting plasma cotinine. γ-TmT increased plasma γ-T by 4-times and the urinary metabolite of γ-T, γ-carboxyethyl-chromanol, by three times. Smoking abstinence with γ-TmT, but not smoking abstinence alone, increased FMD without affecting plasma nitrate/nitrite or the ratio of asymmetric dimethylarginine/arginine. Urinary 8-iso-15(S)-PGF2α decreased only in those receiving γ-TmT and was inversely correlated to FMD (R = -0.43, P < 0.05). Circulating markers of inflammation were unaffected by smoking abstinence or γ-TmT. Short-term NRT-assisted smoking abstinence with γ-TmT, but not NRT-assisted smoking abstinence alone, improved VEF by decreasing 8-iso-15(S)-PGF2α, a vasoconstrictor that was otherwise unaffected by NRT-assisted smoking abstinence.

γ-Tocopherol-rich supplementation additively improves vascular endothelial function during smoking cessation

Oxidative stress and inflammation persist years after smoking cessation thereby limiting the restoration of vascular endothelial function (VEF). Although short-term smoking cessation improves VEF, no studies have examined co-therapy of antioxidants in combination with smoking cessation to improve VEF. We hypothesized that improvements in γ-tocopherol (γ-T) status during smoking cessation would improve VEF beyond that from smoking cessation alone by decreasing oxidative stress and proinflammatory responses. A randomized, double-blind, placebo-controlled study was conducted in otherwise healthy smokers (22 ± 1 years; mean ± SEM) who quit smoking for 7 days with placebo (n=14) or γ-T-rich supplementation (n=16; 500 mg γ-T/day). Brachial artery flow-mediated dilation (FMD), cotinine, and biomarkers of antioxidant status, oxidative stress, and inflammation were measured before and after 7 days of smoking cessation. Smoking cessation regardless of supplementation similarly decreased plasma cotinine, whereas γ-T-rich supplementation increased plasma γ-T by seven times and its urinary metabolite γ-carboxyethyl hydroxychroman by nine times (P<0.05). Smoking cessation with γ-T-rich supplementation increased FMD responses by 1.3% (P<0.05) beyond smoking cessation alone (4.1 ± 0.6% vs 2.8 ± 0.3%; mean ± SEM). Although plasma malondialdehyde decreased similarly in both groups (P<0.05), plasma oxidized LDL and urinary F2-isoprostanes were unaffected by smoking cessation or γ-T-rich supplementation. Plasma TNF-α and myeloperoxidase decreased (P<0.05) only in those receiving γ-T-rich supplements and these were inversely related to FMD (P<0.05; R=-0.46 and -0.37, respectively). These findings demonstrate that short-term γ-T-rich supplementation in combination with smoking cessation improved VEF beyond that from smoking cessation alone in young smokers, probably by decreasing the proinflammatory mediators TNF-α and myeloperoxidase.

Low-fat milk ingestion prevents postprandial hyperglycemia-mediated impairments in vascular endothelial function in obese individuals with metabolic syndrome

Greater intakes of low-fat dairy foods are associated with a lower risk of cardiovascular disease. The objective of this study was to examine whether acute low-fat milk ingestion would limit postprandial impairments in vascular endothelial function by limiting oxidative stress responses that decrease nitric oxide (NO) bioavailability. A randomized, double-blind, cross-over study was conducted in adults with metabolic syndrome (MetS) who ingested low-fat milk (475 mL) or an isocaloric volume of rice milk after an overnight fast. Brachial artery flow-mediated dilation (FMD), plasma glucose, malondialdehyde (MDA), arginine (ARG), and asymmetric dimethylarginine (ADMA) were assessed at 30-min intervals during the 3-h postprandial period. Participants' (n = 19) postprandial FMD responses were unaffected by low-fat milk but transiently decreased (P < 0.01) from 6.2 ± 0.8% (mean ± SEM) at baseline to 3.3 ± 0.7% at 30 min and 3.9 ± 0.6% at 60 min following rice milk consumption. Glucose and MDA increased to a greater extent in the rice milk trial (P < 0.001). The MDA area under the 3 h postprandial curve (AUC0-3 h) was correlated with glucose AUC0-3 h (r = 0.75; P < 0.01) and inversely related to FMD AUC0-3 h (r = -0.59; P < 0.01). ARG decreased following rice milk and increased with low-fat milk, whereas only rice milk increased ADMA:ARG. The ADMA:ARG AUC0-3 h was correlated with MDA AUC0-3 h (r = 0.55) and was inversely related to FMD AUC0-3 h (r = -0.52) (P < 0.05). These findings suggest that low-fat milk maintains vascular endothelial function in individuals with MetS by limiting postprandial hyperglycemia that otherwise increases lipid peroxidation and reduces NO bioavailability. This trial was registered at clinicaltrials.gov as NCT01411293.

Acute glutathione depletion induces hepatic methylglyoxal accumulation by impairing its detoxification to d-lactate

Methylglyoxal (MGO) is a dicarbonyl that reacts with amino acids and nucleic acids to form advanced glycation endproducts, which may contribute to diabetes and its cardiovascular complications. MGO detoxification through the glyoxalase (GLO) pathway is glutathione (GSH)-dependent, but no studies have investigated whether acute depletion of GSH regulates MGO accumulation in vivo. We therefore administered a single intraperitoneal injection of the specific GSH biosynthesis inhibitor l-buthionine-( RS)-sulfoximine (BSO; 4 mmol/kg) or phosphate-buffered saline vehicle to six-week-old Sprague Dawley rats ( n = 48) prior to sacrificing at 0, 6, 12 and 48 h ( n = 6/time point/treatment). BSO had no effect ( P > 0.05) on adipose or plasma MGO at any specific time points following treatment. In contrast, hepatic GSH was 68–71% lower ( P < 0.05) at 6–12 h following BSO, and MGO was 27% higher at 12 h. At 12 h, hepatic d-lactate was 13% lower and GLO activity was 52% lower following BSO, which was fully restored by the exogenous addition of GSH. Hepatic GSH was inversely related to hepatic MGO ( r = −0.81; P < 0.01) and positively correlated with hepatic GLO activity ( r = 0.72; P < 0.01), whereas hepatic GLO activity was positively correlated with hepatic d-lactate ( r = 0.63; P < 0.05). BSO had no effect on hepatic malondialdehyde or vitamin E. These findings demonstrate that GSH depletion in vivo increases hepatic MGO accumulation by impairing its GSH-dependent, GLO-mediated detoxification to d-lactate independent of oxidative stress.

Anti-HLA class II antibodies in kidney retransplant patients

The relevance of anti-HLA class II antibodies for kidney graft survival is still controversial. In part, this can be attributed to difficulties to detect and differentiate anti-HLA class II antibodies. Anti-HLA class II IgG antibody screening was performed by enzyme-linked immunosorbent assay. Subsequently, all anti-HLA class II-positive sera were subjected to the determination and specification using color-coded microspheres coated with purified HLA antigens. In a cohort of 934 patients awaiting kidney transplantation, 41 sera (4.4%) were positive for IgG anti-HLA class II antibodies. The presence was confirmed in 90.2% sera by retesting. Subsequently, all anti-HLA class II-positive patients (n = 27) who in the past had undergone a kidney transplantation with an HLA-DR and/or -DQ-mismatched graft were selected. In 25 of 27 sera (92.6%), the alloantibody specificities corresponded to the known previous transplant mismatches on a broad antigen level. In 20 of 27 sera (74.1%), anticlass I antibodies were detected as well. Anti-HLA-DP antibodies were seen in 24 of the 27 sera of this cohort. In the majority of the cases, the reactivities with different DPB1 alleles could be explained by involvement of a single, specific DPB1 epitope. Donor-specific anti-HLA-DR and -DQ antibodies were seen in the majority of cases with graft failure following HLA class II alloantigen exposure in prior kidney transplantations. In addition, HLA-DP may serve as a transplantation antigen in kidney transplantation, leading to a humoral response.

Assembly of alternating polycation and DNA multilayer films by electrostatic layer-by-layer adsorption

The assembly of alternating DNA and positively charged poly(dimethyldiallylammonium chloride) (PDDA) multilayer films by electrostatic layer-by-layer adsorption has been studied. The real-time surface plasmon resonance (BIAcore) technique was used to characterize and monitor the formation of multilayer films in solution in real time continuously. Electrochemical impedance spectroscopy (EIS) and UV-vis absorbance measurements were also used to study the film assembly, and linear film growth was observed. All the results indicate that the uniform multilayer can be obtained on the poly(ethylenimine)- (PEI-) coated substrate surface. The kinetics of the adsorption of DNA on PDDA surface was also studied by the real-time BIAcore technique; the observed rate constant was calculated using a Langmuir model (k(obs) = (1.28 +/- 0.08) x 10(-2) s(-1).

Acute and subacute toxicity and efficacy of S-nitrosylated captopril, an ACE inhibitor possessing nitric oxide activities

The toxicity and efficacy of S-nitrosocaptopril (CapNO), a novel vasodilator possessing the capacities of both a nitric oxide donor and an angiotensin converting enzyme (ACE) inhibitor, were examined in rodents. In single-dose acute toxicity studies in ICR mice, the median lethal dose (LD(50)) for CapNO was 674+/-94 mg/kg (iv) and 2078+/-100 mg/kg (po), whereas for oral captopril was 4286+/-173 mg/kg. S-nitrosoglutathione, containing the same S-nitroso moiety as CapNO, showed an LD(50) equal to CapNO when the values were expressed by the mol/kg. The cause of acute death by the high doses of CapNO was lethal hypotension. In the subacute toxicity studies, oral CapNO was well tolerated in normotensive and hypertensive rats at doses up to 500 mg/kg/day for 3 months, except for considerable reductions in food consumption and growth rate observed in the 500 mg/kg/day group. Serum chemistry and hematology tests performed in the subacute toxicity studies revealed no adverse effects of oral CapNO except for a significant decrease in cholesterol levels in hypertensive SHR rat. At autopsy, no histopathological changes in major organs were observed over the subacute period. Administration of a therapeutic dose of CapNO (iv, 250 microg/kg which produced 25% decreases in blood pressure) revealed no changes in the hematological parameters. Subchronic treatment of SHR and SS/Jr rats with oral CapNO (50 mg/kg/day) significantly reduced mean arterial pressure to the normotensive level. Considering the absence of adverse effects of CapNO in the subchronic toxicity study, CapNO appears to be a safe drug for further clinical trials, but particular caution must be taken because it can cause hypotension when overdosed.

Ion-induced rectification of nanoparticle quantized capacitance charging in aqueous solutions

Ion-induced rectification of nanoparticle quantized capacitance charging was studied using nanoparticle self-assembled monolayers in aqueous solutions in the presence of some unique electrolyte ions. The rectified charging features were interpreted on the basis of a Randles equivalent circuit where the binding of hydrophobic electrolyte ions to surface-confined particle molecules led to the manipulation of the electrode interfacial capacitance. It was found that the rectification effects were directly related to the ion hydrophobicity, manifested by the cathodic (anodic) shift of the onset potential with anions (cations) of increasing hydrophobicity Additionally, the voltammetric responses evolved from those similar to conventional molecular diodes to those of quantized charging rectifiers with increasing anion hydrophobicity. Electron-transfer kinetics evaluated by using various electrochemical methods yielded a rate constant within the range of 10-100 s(-1) which decreased with increasing length of the alkyl spacers with a coupling coefficient (beta) within the range of 0.8-0.9. Comparisons with conventional electroactive functional moieties were also discussed.

Amplification of antigen-antibody interactions based on biotin labeled protein-streptavidin network complex using impedance spectroscopy

Antibody was covalently immobilized by amine coupling method to gold surfaces modified with a self-assembled monolayer of thioctic acid. The electrochemical measurements of cyclic voltammetry and impedance spectroscopy showed that the hexacyanoferrate redox reactions on the gold surface were blocked due to the procedures of self-assembly of thioctic acid and antibody immobilization. The binding of a specific antigen to antibody recognition layer could be detected by measurements of the impedance change. A new amplification strategy was introduced for improving the sensitivity of impedance measurements using biotin labeled protein-streptavidin network complex. This amplification strategy is based on the construction of a molecular complex between streptavidin and biotin labeled protein. This complex can be formed in a cross-linking network of molecules so that the amplification of response signal will be realized due to the big molecular size of complex. The results show that this amplification strategy causes dramatic improvement of the detection sensitivity of hIgG and has good correlation for detection of hIgG in the range of 2-10 microg/ml.

The stability of cytokeratin 18 in human liver cells during colchicine-induced microtubule disruption

The cytoskeleton plays important roles in cell function and is therefore implicated in the pathogenesis of many human liver diseases, including malignant tumors. The stability of cytokeratin proteins during tumor transformation in human hepatocellular carcinoma has been studied with a molecular approach previously. The results demonstrate that the cytokeratin is modulated in human hepatocellular carcinoma. Besides this, three low molecular weight cytokeratin molecules (named HCC CK) are found. This indicates that these HCC CKs have undergone modulation from the human hepatocyte cytokeratin 18. We also checked the cytokeratin profile of the human hepatoma cell line PLC/PRF/5 with the same methods to ensure the HCC CK molecules are produced by modulation but not protein degradation. The stability of cytokeratin molecules was studied by a different approach. The cytokeratin compositions of human liver cells (Chang cell line) were analysed under the effects of microtubule-disrupting drug (colchicine) by SDS-PAGE, Western blot, immunoprecipitation using a commercially available monoclonal anti-cytokeratin 18 antibody and immunofluorescent staining. Within 1 h of treatment, the microtubule began to collapse and the filamentous structure was shortening. The microtubule had almost collapsed and became fragmented to form a lattice-like network after 24 h of treatment. The cytokeratin was modulated after long-term (24 h) treatment of colchicine, and the molecular weight became 14 kD and the antigenicity was lost. The stability of cytokeratin molecules was related to the intact microtubule network, after disruption of the microtubule the cytokeratin would be modulated. The intact microtubule network was a stabilizing factor of cytokeratin 18 in human liver cells.

Enhanced surface plasmon resonance immunosensing using a streptavidin-biotinylated protein complex

In this paper, we present a novel strategy for improving the sensitivity of surface plasmon resonance immunosensing using a streptavidin-biotinylated protein complex. This amplification strategy is based on the construction of a molecular complex between streptavidin and biotin labeled protein. The complex can be formed in a cross-linking network of molecules so that the amplification of the response signal will be realized due to the big molecular size of the complex. The results show that the amplification strategy causes a dramatic improvement of the detection sensitivity. hIgG protein could be detected in the range of 0.005-10 micrograms ml-1.

Flow cytometric detection of HLA antibodies using a spectrum of microbeads

We describe here the use of HLA antigen coated beads for specificity and class determination of HLA antibodies by flow cytometry. The HLA specificity of antibodies was determined by use of beads containing eight levels of fluorescence. HLA antigens isolated from eight cultured cells were coated onto these beads so that each bead was the equivalent of one cell. By using four sets of eight beads, an equivalent of 32 cells could be examined in four test tubes. A total of 76 class I and 25 class II specificities could be determined by the 32 class I bead-panel and 32 class II bead-panel used, respectively. We noted no cross-reactivity of reactions between class I and II. The sensitivity of the test was shown to be higher than that of the standard cytotoxicity by dilution experiments and detection of additional cross-reacting antigens. By use of these coated beads, we achieved improved standardized detection of HLA antibodies. Antigen-coated beads have several advantages over the use of spleens or lymphocytes. (a) A highly selected panel of antigens can be routinely used. (b) Class I and class II antibodies can be readily distinguished from each other, even when they are present as mixtures in one serum. (c) Non-HLA antibodies are not detected because the beads do not have any other antigens than HLA on them. (d) The quantity of antigens coated on beads is more uniform than that found in cells from different individuals. (e) Beads are more convenient for storage and daily use.

Simultaneous HLA Class I and Class II antibodies screening with flow cytometry

A flow cytometric method of simultaneously screening both HLA Class I and Class II panel reactive antibodies (PRA) was developed using a pool of 30 different Class I and 30 different Class II microbeads coated with purified HLA antigens. The antibodies in the serum that react specifically to the coated HLA antigens are detected by using a FITC-conjugated antibody against human IgG. Percent PRA can be determined by the percentage of microbeads that react positively to the serum. There is no cross-reactivity between the Class I and Class II microbeads. A mixture of Class I and Class II microbeads can be distinguished by their different fluorescent properties on the flow cytometry analysis. Thus, both Class I and Class II PRA can be detected from a single tube reaction.

A simultaneous negative and positive selection method that can detect chimerism at a frequency of 1 per 10,000 by flow cytometry

A three-color flow cytometric method with a simultaneous negative and positive selection (SNAPS) approach has been developed to detect blood chimerism using a FITC-conjugated recipient-specific HLA monoclonal antibody, a biotinylated donor-specific HLA monoclonal antibody and Cy5-PE-conjugated streptavidin and a PE-conjugated CD3 monoclonal antibody. Detection of simulated blood chimerism at a frequency of 0.01% was achieved by SNAPS. In contrast, by one-color flow cytometry methods, chimerism can be detected at only about 3-4% with the same donor-specific HLA monoclonal antibody. The percentages of donor CD3 cells detected by SNAPS are proportional to the percentages of donor CD3 cells counted. SNAPS method provides a fast, sensitive and reliable way to analyze trace amounts of donor cells in a recipient's blood.

Cloning of a transcriptionally active human TATA binding factor

Transcription factor IID (TFIID) binds to the TATA box promoter element and regulates the expression of most eukaryotic genes transcribed by RNA polymerase II. Complementary DNA (cDNA) encoding a human TFIID protein has been cloned. The human TFIID polypeptide has 339 amino acids and a molecular size of 37,745 daltons. The carboxyl-terminal 181 amino acids of the human TFIID protein shares 80% identity with the TFIID protein from Saccharomyces cerevisiae. The amino terminus contains an unusual repeat of 38 consecutive glutamine residues and an X-Thr-Pro repeat. Expression of DNA in reticulocyte lysates or in Escherichia coli yielded a protein that was competent for both DNA binding and transcription activation.

Yeast TATA-box transcription factor gene

The first step in the transcription of most protein-encoding genes in eukaryotes is the binding of a transcription factor to the TATA-box promoter element. This TATA-box transcription factor was purified from extracts of the yeast Saccharomyces cerevisiae by using reconstitution of in vitro transcription reactions as an assay. The activity copurified with a protein whose sodium dodecyl sulfate/polyacrylamide gel mobility is 25 kDa. The sequence of the amino-terminal 21 residues of this protein was determined by sequential Edman degradation. A yeast genomic library was screened with mixed oligonucleotides encoding six residues of the protein sequence. The yeast TATA-box factor gene was cloned, and DNA sequencing revealed a 720-base-pair open reading frame encoding a 27,016-Da protein. The identity of the clone was confirmed by expressing the gene in Escherichia coli and detecting TATA-box factor DNA binding and transcriptional activities in extracts of the recombinant E. coli. The TATA-box factor gene was mapped to chromosome five of S. cerevisiae. RNA blot hybridization and nuclease S1 analysis indicated that the major TATA-box factor mRNA is 1.3 kilobases, including an unusually long 5' untranslated region of 188 +/- 5 nucleotides. Homology searches showed a region of distant similarity to the calcium-binding structures of calpains, a structure that has a conformation similar to the helix-turn-helix motif of DNA binding proteins.