Study on the characteristics of glycerides and phospholipids in human milk from Tibet.

The unique geographical characteristics and food culture of Tibet can affect the nutrition of human milk lipids. But little has been done in the comparison of the lipids between Tibet and other areas. This study gives in-depth analysis of the species, concentration and composition of lipid subclasses at the molecular level of the Tibetan human milk. There were averagely 132 ± 30 species of lipids, among which triglycerides (TAGs), phosphatidylethanolamine (PE) and sphingomyelin (SM) accounted for 79.78% of the total species number in the Tibetan human milk samples. The contents of TAG, SM, phosphatidylcholine (PC), and PE in the Tibetan human milk were 85.84%, 17.79%, 25.94% and 55.81% of those in the comparative human milk of China, respectively. The contents of TAGs and diglycerides (DAGs) with PUFAs in Tibetan human milk were significantly lower than those in the comparative group. However, the content and percentage of TAGs and DAGs with odd-chain saturated fatty acids were both higher in the Tibetan human milk than those in the comparative human milk. In total, 18 molecular species of lipids were downregulated and 5 ones were upregulated in the Tibetan human milk compared with those in the comparative human milk of China. The profile of lipids in the Tibetan human milk at the molecular level provided the scientific basis for maternal diet and supplemented the Chinese human milk lipids database.

'Blue Route' for combating climate change.

Today's urban water system can be transformed, without big modifications, into a natural and revolutionary "Blue Route" for combating climate change and constructing carbon neutral city, which will lead to self-sustainability of the water sector and supply energy and resources to other sectors.

PD-L1 (Programmed Death Ligand 1) Regulates T-Cell Differentiation to Control Adaptive Venous Remodeling.

OBJECTIVE: Patients with end-stage renal disease depend on hemodialysis for survival. Although arteriovenous fistulae (AVF) are the preferred vascular access for hemodialysis, the primary success rate of AVF is only 30% to 50% within 6 months, showing an urgent need for improvement. PD-L1 (programmed death ligand 1) is a ligand that regulates T-cell activity. Since T cells have an important role during AVF maturation, we hypothesized that PD-L1 regulates T cells to control venous remodeling that occurs during AVF maturation. Approach and results: In the mouse aortocaval fistula model, anti-PD-L1 antibody (200 mg, 3×/wk intraperitoneal) was given to inhibit PD-L1 activity during AVF maturation. Inhibition of PD-L1 increased T-helper type 1 cells and T-helper type 2 cells but reduced regulatory T cells to increase M1-type macrophages and reduce M2-type macrophages; these changes were associated with reduced vascular wall thickening and reduced AVF patency. Inhibition of PD-L1 also inhibited smooth muscle cell proliferation and increased endothelial dysfunction. The effects of anti-PD-L1 antibody on adaptive venous remodeling were diminished in nude mice; however, they were restored after T-cell transfer into nude mice, indicating the effects of anti-PD-L1 antibody on venous remodeling were dependent on T cells. CONCLUSIONS: Regulation of PD-L1 activity may be a potential therapeutic target for clinical translation to improve AVF maturation.

E17241 as a Novel ABCA1 (ATP-Binding Cassette Transporter A1) Upregulator Ameliorates Atherosclerosis in Mice.

[Figure: see text].

Inhibition of T-Cells by Cyclosporine A Reduces Macrophage Accumulation to Regulate Venous Adaptive Remodeling and Increase Arteriovenous Fistula Maturation.

OBJECTIVE: Arteriovenous fistulae (AVF) are the preferred vascular access for hemodialysis, but the primary success rate of AVF remains poor. Successful AVF maturation requires vascular wall thickening and outward remodeling. A key factor determining successful AVF maturation is inflammation that is characterized by accumulation of both T-cells and macrophages. We have previously shown that anti-inflammatory (M2) macrophages are critically important for vascular wall thickening during venous remodeling; therefore, regulation of macrophage accumulation may be an important mechanism promoting AVF maturation. Since CD4+ T-cells such as T-helper type 1 cells, T-helper type 2 cells, and regulatory T-cells can induce macrophage migration, proliferation, and polarization, we hypothesized that CD4+ T-cells regulate macrophage accumulation to promote AVF maturation. Approach and Results: In a mouse aortocaval fistula model, T-cells temporally precede macrophages in the remodeling AVF wall. CsA (cyclosporine A; 5 mg/kg, sq, daily) or vehicle (5% dimethyl sulfoxide) was administered to inhibit T-cell function during venous remodeling. CsA reduced the numbers of T-helper type 1 cells, T-helper type 2, and regulatory T-cells, as well as M1- and M2-macrophage accumulation in the wall of the remodeling fistula; these effects were associated with reduced vascular wall thickening and increased outward remodeling in wild-type mice. However, these effects were eliminated in nude mice, showing that the effects of CsA on macrophage accumulation and adaptive venous remodeling are T-cell-dependent. CONCLUSIONS: T-cells regulate macrophage accumulation in the maturing venous wall to control adaptive remodeling. Regulation of T-cells during AVF maturation may be a strategy that can improve AVF maturation. Graphic Abstract: A graphic abstract is available for this article.

Ecological Transitions in Grouping Benefits Explain the Paradox of Environmental Quality and Sociality.

Both benign and harsh environments promote the evolution of sociality. This paradox-societies occur in environments of such contrasting quality-may be explained by the different types of benefits that individuals receive from grouping: resource defense benefits that derive from group-defended critical resources versus collective action benefits that result from social cooperation among group members. Here, we investigate cooperative behavior in the burying beetle Nicrophorus nepalensis along an elevational gradient where environmental quality (climate and competition) varies with altitude. We show that climate (temperature) and competition (both intra- and interspecific) independently and synergistically influence sociality via different grouping benefits that vary along the gradient. At low elevations where interspecific competition for resources is intense, groups gain from the collective action benefit of increased interspecific competitive ability. In contrast, pairs have higher fitness at intermediate elevations where intraspecific competition for resources is greatest because resource defense is the key grouping benefit. However, groups and pairs have similar fitness at high elevations, suggesting that there is no grouping benefit in such physiologically challenging environments. Our results demonstrate that sociality is favored for different reasons under a range of environmental conditions, perhaps explaining why animal societies occur in environments of such contrasting quality.

Resolving the Paradox of Environmental Quality and Sociality: The Ecological Causes and Consequences of Cooperative Breeding in Two Lineages of Birds.

Cooperatively breeding animals occur in virtually every ecosystem on earth. Comparative and biogeographic studies suggest that both benign and harsh-as well as stable and fluctuating-environments can favor the evolution of cooperative breeding behavior. The fact that cooperative societies occur in environments of such contrasting quality creates a paradox of environmental quality and sociality. The dual benefits framework-which leads to the prediction that the ecological consequences of sociality (e.g., range size) vary depending on the benefits that individuals of each species receive by forming social groups-offers a potential resolution to this paradox. Here we use a case study of two avian lineages, starlings (Sturnidae) and hornbills (Bucerotidae), in which environmental unpredictability appears to have opposite effects on the evolution of cooperation to test the dual benefits framework. Consistent with previous work, harsh and unpredictable environments promote cooperative breeding behavior in starlings, which in turn leads to larger geographic ranges. However, cooperatively breeding hornbills occur in benign and stable environments, but sociality does not influence range size. Our study suggests that the paradox of environmental quality and sociality arises largely because cooperative breeding is an umbrella term encompassing social species that form groups for different reasons. We demonstrate that differentiating among the functional causes of social group formation is critical for developing a predictive framework for understanding the evolution of cooperative breeding behavior.

Z-Score transformation of ADC values: A way to universal cut off between malignant and benign lymph nodes.

PURPOSE: To determine the possibility of a universal cut off value between benign and malignant lymph nodes in patients with tumour by Z-Score transformation method. MATERIALS AND METHODS: Diffusion weighted imaging, ADC measurements of malignant and benign lymph nodes of 6 studies (4 body parts), conducted for 5 times, in two institutions with variable technical details were analyzed in their original value as well as the standardized Z-Score value. The standardized Z-Score value was obtained by subtracting the population mean of the control group from an individual raw score and then dividing the difference by the population standard deviation of the control group. General cut off values were obtained by both Mega-analysis by receiver operator characteristic curve analysis, when data from the 6 studies were combined and Meta-analysis with weighting coefficients and cut off values of the six individual studies. Sensitivity, specificity and accuracy with cut offs from individual studies, meta-analysis and mega-analysis were calculated. Kappa test was performed to assess the consistency of diagnostic test accuracy, between optimized cut offs of individual studies and the proposed universal cut offs obtained from meta-analysis and mega-analysis. RESULTS: The ADC values of benign and malignant lymph nodes are significantly different, but with large overlap across the studies. The overlap can be minimized by Z-Score transformation. The result of ROC analysis of the collective Z-Score transformed ADC values of 6 studies was superior to that of the collective original ADC values (sensitivity: 87.4% versus 67.2%, specificity: 90.5% versus 87.9%, accuracy: 89.6% versus 81.4%). The universal Z-Score cut off from Meta-analysis is also better than the original ADC cut off (sensitivity: 82.8% versus 76.3%, specificity 92.6% versus 62.9%, accuracy 89.6% versus 67.1%). Applied to the individual studies, the universal transformed Z-Score cut offs produced superior consistency with the individual optimal cut offs (individual and meta Z-Score: 0.7228-0.9793; individual and mega Z-Score: 0.7111-0.9169) compared with the universal original ADC cut offs (individual and meta ADC: 0.3030-1.0000; individual and mega ADC 0.3268-0.9618). CONCLUSION: Z-Score transformation could minimize inter-study variations due to heterogeneity of MR systems and sequence parameters, and provide a more consistent universal cut off value between benign and malignant nodes across studies.

Arterial spin labeling and altered cerebral blood flow patterns in the minimally conscious state.

OBJECTIVE: To use arterial spin labeling (ASL) to compare cerebral blood flow (CBF) patterns in minimally conscious state (MCS) patients with those in normal controls in an observational study design. METHODS: Subjects meeting MCS criteria and normal controls were identified. A pseudocontinuous ASL sequence was performed with subjects and controls in the resting awake state. Multiple CBF values for 10 predetermined regions of interest were sampled and average CBF was calculated and compared between controls and subjects. RESULTS: Ten normal controls were identified, with ages ranging from 26 to 54 years. Four subjects met the MCS criteria and received an ASL study, with one patient receiving a second study at a later date. Subjects ranged in age from 19 to 58 years and had traumatic brain injury, stroke, or hypoxic-ischemic encephalopathy. Regional CBF for controls ranged from 21.6 to 57.2 mL/100 g/min, with a pattern of relatively increased blood flow posteriorly including the posterior cingulate, parietal, and occipital cortices. CBF patterns for MCS subjects showed greater variability (from 7.7 to 33.1 mL/100 g/min), demonstrating globally decreased CBF in gray matter compared with that in normal controls, especially in the medial prefrontal and midfrontal regions. In the one subject studied longitudinally, global CBF values increased over time, which correlated with clinical improvement. CONCLUSIONS: We identified globally decreased CBF and a selective reduction of CBF within the medial prefrontal and midfrontal cortical regions as well as gray matter in MCS patients. ASL may serve as an adjunctive method to assess functional reserve in patients recovering from severe brain injuries.

Mutations of human topoisomerase II alpha affecting multidrug resistance and sensitivity.

Two mutations, R450Q and P803S, in the coding region of the human topoisomerase II alpha gene have been identified in the atypical multidrug resistant (at-MDR) cell line, CEM/VM-1, which exhibits resistance to many structurally diverse topoisomerase II-targeting antitumor drugs such as VM-26, doxorubicin, m-AMSA, and mitoxantrone. The R450Q mutation mapped in the ATP utilization domain, while the P803S mutation mapped in the vicinity of the active site tyrosine of human topoisomerase II alpha. However, the roles of these two mutations in conferring multidrug resistance are unclear. To study the roles of these two mutations in conferring multidrug resistance, we have characterized the recombinant human DNA topoisomerase II alpha containing either single or double mutations. We show that both R450Q and P803S mutations confer resistance in the absence of ATP. However, in the presence of ATP, the R450Q, but not the P803S, mutation can confer multidrug resistance. The R450Q enzyme was shown to exhibit impaired ATP utilization both for enzyme catalysis and for its ability to form the circular protein clamp. Interestingly, an unrelated mutation, G437E, which is also located in the same domain as the R450Q mutation, exhibited multidrug hypersensitivity in the absence of ATP. However, in the presence of ATP, the G437E enzyme is only minimally hypersensitive to various topoisomerase II drugs. In contrast to the R450Q enzyme, the G437E enzyme exhibited enhanced ATP utilization for enzyme catalysis. In the aggregate, these results support the notion that the multidrug resistance and sensitivity of these mutant enzymes are due to a specific defect in ATP utilization during enzyme catalysis.

Selective cytotoxicity of topoisomerase-directed protoberberines against glioblastoma cells.

Protoberberines are a new class of organic cations that are dual poisons of topoisomerases I and II. Certain protoberberines exhibit greater in vitro cytotoxicity against cell lines derived from solid tumors than from leukemias. Using a group of seventeen different protoberberine analogs, the structural basis for selective cytotoxicity toward sensitive SF-268 glioblastoma cells as compared with resistant RPMI 8402 lymphoblast cells was explored. The selective cytotoxicity is associated with the presence of an imminium ion and other structural features of protoberberines, and is not shared by drugs such as camptothecin, doxorubicin, vinblastine, and etoposide, which are either equally or more cytotoxic against RPMI 8402 cells than SF-268 cells. The selective cytotoxicity of protoberberines against SF-268 over RPMI 8402 cells is not due to differences in topoisomerase levels or known drug efflux systems such as multidrug resistance (MDR1) and multidrug-resistance protein (MRP). Comparative in vitro studies of the accumulation of coralyne, a fluorescent protoberberine, into sensitive and resistant cells demonstrated a correlation between drug accumulation and selective cytotoxicity. Inhibitors of coralyne uptake included several protoberberine-related compounds. Of these, palmatine, a minimally cytotoxic protoberberine, both inhibited coralyne accumulation and reduced cytotoxicity against SF-268 cells, but not against RPMI 8402 cells. Despite the structural resemblance of protoberberines to catecholamines, our experiments using inhibitors and cells expressing biogenic amine uptake systems have ruled out the involvement of biogenic amine uptake1, uptake2, and vesicular monoamine transport systems. Uptake systems remaining as candidates, supported by preliminary data, include transport via vesicles derived from specialized membrane invaginations and selected carrier-mediated organic amine transport systems.

Differential poisoning of topoisomerases by menogaril and nogalamycin dictated by the minor groove-binding nogalose sugar.

The effect of DNA binding on poisoning of human DNA TOP1 has been studied using a pair of related anthracyclines which differ only by a nogalose sugar ring. We show that the nogalose sugar ring of nogalamycin, which binds to the minor groove of DNA, plays an important role in affecting topoisomerase-specific poisoning. Using purified mammalian topoisomerases, menogaril is shown to poison topoisomerase II but not topoisomerase I. By contrast, nogalamycin poisons topoisomerase I but not topoisomerase II. Consistent with the biochemical studies, CEM/VM-1 cells which express drug-resistant TOP2alpha are cross-resistant to menogaril but not nogalamycin. The mechanism by which nogalamycin poisons topoisomerase I has been studied by analyzing a major topoisomerase I-mediated DNA cleavage site induced by nogalamycin. This site is mapped to a sequence embedded in an AT-rich region with four scattered GC base pairs (bps) (at -10, -6, +2, and +12 positions). GC bps embedded in AT-rich regions are known to be essential for nogalamycin binding. Surprisingly, DNase I footprinting analysis of nogalamycin-DNA complexes has revealed a drug-free region from -2 to +9 encompassing the major cleavage site. Our results suggest that nogalamycin, in contrast to camptothecin, may stimulate TOP1 cleavage by binding to a site(s) distal to the site of cleavage.

Induction of DNA topoisomerase II-mediated DNA cleavage by beta-lapachone and related naphthoquinones.

Recent studies have suggested that 3,4-dihydro-2,2-dimethyl-2H-naphtho[1,2-b]pyran-5,6-dione (beta-lapachone) inhibits DNA topoisomerase I by a mechanism distinct from that of camptothecin. To study the mechanism of action of beta-lapachone, a series of beta-lapachone and related naphthoquinones were synthesized, and their activity against drug-sensitive and -resistant cell lines and purified human DNA topoisomerases as evaluated. Consistent with the previous report, beta-lapachone does not induce topoisomerase I-mediated DNA breaks. However, beta-lapachone and related naphthoquinones, like menadione, induce protein-linked DNA breaks in the presence of purified human DNA topoisomerase IIalpha. Poisoning of topoisomerase IIalpha by beta-lapachone and related naphthoquinones is independent of ATP and involves the formation of reversible cleavable complexes. The structural similarity between menadione, a para-quinone, and beta-lapachone, an ortho-quinone, together with their similar activity in poisoning topoisomerase IIalpha, suggests a common mechanism of action involving chemical reactivity of these quinones. Indeed, both quinones form adducts with mercaptoethanol, and beta-lapachone is 10-fold more reactive. There is an apparent correlation between the rates of the adduct formation with thiols and of the topoisomerase II-poisoning activity of the aforementioned quinones. In preliminary studies, beta-lapachone and related naphthoquinones are found to be cytotoxic against a panel of drug-sensitive and drug-resistant tumor cell lines, including MDR1-overexpressing cell lines, camptothecin-resistant cell lines, and the atypical multidrug-resistant CEM/V-1 cell line.

Human DNA topoisomerase I is encoded by a single-copy gene that maps to chromosome region 20q12-13.2.

cDNA clones of the human TOP1 gene encoding DNA topoisomerase I (EC 5.99.1.2) have been obtained by immunochemical screening of phage lambda libraries expressing human cDNA segments, using rabbit antibodies raised against purified HeLa DNA topoisomerase I. Hybridization patterns between the cloned cDNA sequences and human cellular DNA and cytoplasmic mRNAs indicate that human TOP1 is a single-copy gene. The chromosomal location of the gene has been mapped to the long arm of chromosome 20, in the region q12-13.2, by hybridization of a radioactively labeled TOP1 cDNA probe to human metaphase chromosomes and to a panel of rodent-human somatic hybrids retaining overlapping subsets of human chromosomes.

Cloning and sequencing of cDNA encoding human DNA topoisomerase II and localization of the gene to chromosome region 17q21-22.

Two overlapping cDNA clones encoding human DNA topoisomerase II were identified by two independent methods. In one, a human cDNA library in phage lambda was screened by hybridization with a mixed oligonucleotide probe encoding a stretch of seven amino acids found in yeast and Drosophila DNA topoisomerase II; in the other, a different human cDNA library in a lambda gt11 expression vector was screened for the expression of antigenic determinants that are recognized by rabbit antibodies specific to human DNA topoisomerase II. The entire coding sequences of the human DNA topoisomerase II gene were determined from these and several additional clones, identified through the use of the cloned human TOP2 gene sequences as probes. Hybridization between the cloned sequences and mRNA and genomic DNA indicates that the human enzyme is encoded by a single-copy gene. The location of the gene was mapped to chromosome 17q21-22 by in situ hybridization of a cloned fragment to metaphase chromosomes and by hybridization analysis with a panel of mouse-human hybrid cell lines, each retaining a subset of human chromosomes.