Effects of oolong tea on metabolism of plasma fat in mice under restraint stress

We investigated the effects of oolong tea on the basic metabolism of plasma lipids in mice under restraint stress. When a lipid emulsion (Intralipid 20%; a lipid emulsion containing 20% soybean oil) was injected intravenously into mice, the restraint stress prolonged the half-life (T 1/2) of elimination for plasma triglyceride (TG) from 28.7 to 55.5 min. The elimination rate per minute was 48.2% in stressed mice with the rate in starved control mice as 100%. Therefore, TG metabolism was disrupted by the stress, and the use of TG as an energy source decreased. We found that the metabolism of lipids significantly response to the restrained stress in the present study. Plasma TG was 515.9 +/- 29.9mg/dl 35min after Intralipid administration in control stressed mice, 478.7 +/- 26.7 mg/dl in the stressed group given caffeine 100 mg/kg of body weight, and 418.3 +/- 18.4 mg/dl in the stressed group given 1,000 mg/kg oolong tea, an improvement by 7.2% and 18.9%, respectively, with the value for the untreated control group. The intake of oolong tea alleviated the stress-induced decrease in the rate of blood lipid metabolism; this effect may have arisen from some non-specific stress-relieving property of the tea or from acceleration of lipid metabolism by properties of polyphenols, etc. in tea. Oolong tea had anti-stress effects on plasma TG metabolism, and the effects did not depend on caffeine.     

Structure,function and DNA composition of Saccharomyces cerevisiae chromatin loops

Recent localization of cohesin association regions along the yeast chromatin fibre suggests that compositional variability of DNA in yeast is related to the function and organization of the chromosomal loops. The bases of the loops, where the chromatin fibre is attached to the chromosomal axis, are AT-rich, bind cohesin, and are flanked by genes transcribed convergently. The hotspots of meiotic recombination are mainly found in the GC-rich parts of the loops, ‘external’ with respect to the chromosomal axis, frequently in the vicinity of the promoters of divergently transcribed genes. There are two possible reasons why the regions of the hotspots of recombination were enriched in GC content during evolution. One is a biased repair of recombination intermediates, and the second is a selective advantage due to an increased chromatin accessibility, which may have the carriers of GC-enriched alleles over the carriers of AT-rich alleles.     

Processing of N-glycans of two yellow lupin phosphohydrolases during seed maturation and dormancy

Acid phosphatase (AP) and diphosphonucleoside phosphatase/phosphodiesterase (PPD1) were purified from yellow lupin (Lupinus luteus L.) immature green seeds (40 days after blooming), dry seeds (40 days later) and dry seeds stored for 160 days. Both enzymes are known to differ in the type of N-glycosylation: the first has an N-glycosylation pattern typical for a vacuolar protein, while the second enzyme has a pattern typical for an extracellular or membrane-bound protein. N-Glycans were released from each of the enzyme preparations, fluorescence labeled, separated and identified by HPLC (GlycoSep N and GlycoSep H columns). Changes in the level of each N-glycan during seed maturation and dormancy were compared. The results show that N-glycan processing in the case of AP and PPD1-two proteins residing in the same plant organ, but possibly in different compartments-is not synchronized and performed not only in metabolically active maturing seeds, but also in metabolically inactive dormant seeds.     

Regulation and protection of mitochondrial physiology by sirtuins

The link between sirtuin activity and mitochondrial biology has recently emerged as an important field. This conserved family of NAD(+)-dependent deacetylase proteins has been described to be particularly involved in metabolism and longevity. Recent studies on protein acetylation have uncovered a high number of acetylated mitochondrial proteins indicating that acetylation/deacetylation processes may be important not only for the regulation of mitochondrial homeostasis but also for metabolic dysfunction in the context of various diseases such as metabolic syndrome/diabetes and cancer. The functional involvement of sirtuins as sensors of the redox/nutritional state of mitochondria and their role in mitochondrial protection against stress are hereby described, suggesting that pharmacological manipulation of sirtuins is a viable strategy against several pathologies.     

Contribution of STAT4 gene single-nucleotide polymorphism to systemic lupus erythematosus in the Polish population

The STAT4 has been found to be a susceptible gene in the development of systemic lupus erythematosus (SLE) in various populations. There are evident population differences in the context of clinical manifestations of SLE, therefore we investigated the prevalence of the STAT4 G > C (rs7582694) polymorphism in patients with SLE (n = 253) and controls (n = 521) in a sample of the Polish population. We found that patients with the STAT4 C/G and CC genotypes exhibited a 1.583-fold increased risk of SLE incidence (95 % CI = 1.168-2.145, p = 0.003), with OR for the C/C versus C/G and G/G genotypes was 1.967 (95 % CI = 1.152-3.358, p = 0.0119). The OR for the STAT4 C allele frequency showed a 1.539-fold increased risk of SLE (95 % CI = 1.209-1.959, p = 0.0004). We also observed an increased frequency of STAT4 C/C and C/G genotypes in SLE patients with renal symptoms OR = 2.259 (1.365-3.738, p = 0.0014), (p (corr) = 0.0238) and in SLE patients with neurologic manifestations OR = 2.867 (1.467-5.604, p = 0.0016), (p (corr) = 0.0272). Moreover, we found a contribution of STAT4 C/C and C/G genotypes to the presence of the anti-snRNP Ab OR = 3.237 (1.667-6.288, p = 0.0003), (p (corr) = 0.0051) and the presence of the anti-Scl-70 Ab OR = 2.665 (1.380-5.147, p = 0.0028), (p (corr) = 0.0476). Our studies confirmed an association of the STAT4 C (rs7582694) variant with the development of SLE and occurrence of some clinical manifestations of the disease.     

Ecosystem state shifts during long‐term development of an Amazonian peatland

The most carbon (C)‐dense ecosystems of Amazonia are areas characterized by the presence of peatlands. However, Amazonian peatland ecosystems are poorly understood and are threatened by human activities. Here, we present an investigation into long‐term ecohydrological controls on C accumulation in an Amazonian peat dome. This site is the oldest peatland yet discovered in Amazonia (peat initiation ca. 8.9 ka BP), and developed in three stages: (i) peat initiated in an abandoned river channel with open water and aquatic plants; (ii) inundated forest swamp; and (iii) raised peat dome (since ca. 3.9 ka BP). Local burning occurred at least three times in the past 4,500 years. Two phases of particularly rapid C accumulation (ca. 6.6–6.1 and ca. 4.9–3.9 ka BP), potentially resulting from increased net primary productivity, were seemingly driven by drier conditions associated with widespread drought events. The association of drought phases with major ecosystem state shifts (open water wetland–forest swamp–peat dome) suggests a potential climatic control on the developmental trajectory of this tropical peatland. A third drought phase centred on ca. 1.8–1.1 ka BP led to markedly reduced C accumulation and potentially a hiatus during the peat dome stage. Our results suggest that future droughts may lead to phases of rapid C accumulation in some inundated tropical peat swamps, although this can lead ultimately to a shift to ombrotrophy and a subsequent return to slower C accumulation. Conversely, in ombrotrophic peat domes, droughts may lead to reduced C accumulation or even net loss of peat. Increased surface wetness at our site in recent decades may reflect a shift towards a wetter climate in western Amazonia. Amazonian peatlands represent important carbon stores and habitats, and are important archives of past climatic and ecological information. They should form key foci for conservation efforts.     

Studies on the anti-hepatitis C virus activity of newly synthesized tropolone derivatives: Identification of NS3 helicase inhibitors that specifically inhibit subgenomic HCV replication

We synthesized new tropolone derivatives substituted with cyclic amines: piperidine, piperazine or pyrrolidine. The most active anti-helicase compound (IC₅₀ = 3.4 μM), 3,5,7-tri[(4′-methylpiperazin-1′-yl)methyl]tropolone (2), inhibited RNA replication by 50% at 46.9 μM (EC₅₀) and exhibited the lowest cytotoxicity (CC₅₀) >1 mM resulting in a selectivity index (SI = CC₅₀/EC₅₀) >21. The most efficient replication inhibitor, 3,5,7-tri[(4′-methylpiperidin-1′-yl)methyl]tropolone (6), inhibited RNA replication with an EC₅₀ of 32.0 μM and a SI value of 17.4, whereas 3,5,7-tri[(3′-methylpiperidin-1′-yl)methyl]tropolone (7) exhibited a slightly lower activity with an EC₅₀ of 35.6 μM and a SI of 9.8.     

The effect of three novel thromboxane A2 receptor antagonists (S-1452, AA-2414 and ONO-3708) on the increase in pulmonary pressure caused by Forssman anaphylaxis in guinea-pigs.

The effects were studied of three novel thromboxane A2 (TXA2) receptor antagonists (S-1452, AA-2414 and ONO-3708) on the increase in pulmonary pressure caused by Forssman anaphylaxis in guinea-pigs. Three TXA2 antagonists at doses of between 1 and 10 mg/kg administered orally 1 h before the challenge clearly inhibited the pulmonary pressure increase. At a dose of 10 mg/kg, all three antagonists inhibited the pulmonary pressure increase caused by leukotriene D4 (LTD4) and U-46619, but not that caused by histamine. The decrease in peripheral platelet counts caused by Forssman anaphylaxis was also clearly inhibited by the three TXA2 antagonists. However, the decreased peripheral leukocyte counts were unaffected by the three agents. The decrease in serum complement activity (CH50) was inhibited by S-1452 and AA-2414 at a dose of 10 mg/kg. In bronchoalveolar lavage fluid (BALF), significant increases in eosinophils and neutrophils were observed after Forssman anaphylaxis. Three TXA2 antagonists at a dose of 10 mg/kg (except for AA-2414 on eosinophils) did not affect the changes of leukocyte counts in BALF. Moreover, increases in the TXB2 and 6-keto-PGF1 alpha levels of the BALF brought about by Forssman anaphylaxis were unaffected by the three TXA2 receptor antagonists. Histamine and LTD4 were not changed in the BALF after Forssman anaphylaxis. These results indicate the efficacy of TXA2 receptor antagonists on the increase in pulmonary pressure caused by Forssman anaphylaxis in guinea-pigs by direct antagonism to released TXA2.     

Solid phase synthesis of peptide hydroxamic acids on poly(ethylene glycol)‐based support

A novel resin designed for solid‐phase synthesis of peptide hydroxamic acids (PHA) combining the trityl linker with poly(ethylene glycol)‐based support, ChemMatrix® type, is described. The synthesis of PHA can be performed according to a standard protocol, providing products in excellent purity and reasonable yields. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd.