X-band and S-band EPR detection of nitric oxide in murine endotoxaemia using spin trapping by ferro-di(N-(dithiocarboxy)sarcosine)

Ammonium salt of N-(dithiocarboxy)sarcosine (DTCS) chelated to ferrous salt was tested as an NO-metric spin trap at room temperature for ex vivo measurement of (.)NO production in murine endotoxaemia. In a chemically defined in vitro model system EPR triplet signals of NO-Fe(DTCS)(2) were observed for as long as 3 hours, only if samples were reduced with sodium dithionite. This procedure was not necessary for the ex vivo detection of (.)NO in endotoxaemic liver homogenates at X-band or in the whole intact organs at S-band, whereas only a weak signal was observed in endotoxaemic lung. These results suggest that in endotoxaemia not only high level of (.)NO, but also the redox properties of liver and lung might determine the formation of complexes of (.)NO with a spin trap. Nevertheless, both S- and X-band EPR spectroscopy is suitable for (.)NO-metry at room temperature using Fe(DTCS)(2) as the spin trapping agent. In particular, S-band EPR spectroscopy enables the detection of (.)NO production in a whole organ, such as murine liver.     

Dibenzocyclooctadiene-type lignans from Magnolia pyramidata

Eight dibenzocyclooctadiene-type lignans, pyramidatin A-H, were isolated from the leaves of Magnolia pyramidata. Their structures were established by spectral methods, mainly 2D NMR spectroscopic techniques, which involved combined applications of COSY, DEPT. 1H, 13C correlations, COLOC, INAPT and long-range inverse 1H, 13C NMR correlations. The molecular structures of pyramidatin A and B were determined by single crystal X-ray diffraction. The absolute configurations of all eight lignans were derived from CD spectral correlations with structurally related dibenzocyclooctadienes of known absolute configuration.     

Evolution of the Selfing Syndrome in Arabis alpina (Brassicaceae)

Introduction

The transition from cross-fertilisation (outcrossing) to self-fertilisation (selfing) frequently coincides with changes towards a floral morphology that optimises self-pollination, the selfing syndrome. Population genetic studies have reported the existence of both outcrossing and selfing populations in Arabis alpina (Brassicaceae), which is an emerging model species for studying the molecular basis of perenniality and local adaptation. It is unknown whether its selfing populations have evolved a selfing syndrome.

Methods

Using macro-photography, microscopy and automated cell counting, we compared floral syndromes (size, herkogamy, pollen and ovule numbers) between three outcrossing populations from the Apuan Alps and three selfing populations from the Western and Central Alps (Maritime Alps and Dolomites). In addition, we genotyped the plants for 12 microsatellite loci to confirm previous measures of diversity and inbreeding coefficients based on allozymes, and performed Bayesian clustering.

Results and Discussion

Plants from the three selfing populations had markedly smaller flowers, less herkogamy and lower pollen production than plants from the three outcrossing populations, whereas pistil length and ovule number have remained constant. Compared to allozymes, microsatellite variation was higher, but revealed similar patterns of low diversity and high Fis in selfing populations. Bayesian clustering revealed two clusters. The first cluster contained the three outcrossing populations from the Apuan Alps, the second contained the three selfing populations from the Maritime Alps and Dolomites.

Conclusion

We conclude that in comparison to three outcrossing populations, three populations with high selfing rates are characterised by a flower morphology that is closer to the selfing syndrome. The presence of outcrossing and selfing floral syndromes within a single species will facilitate unravelling the genetic basis of the selfing syndrome, and addressing which selective forces drive its evolution.     

云南常见牛肝菌属真菌中汞含量及食用安全评价

汞(Hg)是危害人类健康的主要重金属元素之一,多数食用菌对Hg有很强的富集能力,测定食用菌中Hg含量,并对其进行食用安全性评价具有重要意义。采用冷原子吸收直接测汞仪系统测定85份云南常见牛肝菌属真菌菌盖、菌柄中总Hg含量;以同一牛肝菌子实体菌盖与菌柄总Hg含量比(Q(C/S))分析牛肝菌属真菌对Hg的富集特征;根据联合国粮农组织和世界卫生组织(FAO/WHO)现行每周Hg允许摄入量(provisional tolerable weekly intake,PTWI)标准和中国GB 2762—2012规定的食用菌中Hg限量标准评价样品的食用安全性。结果表明,菌盖和菌柄中总Hg含量分别在0.13~22.00、0.20~8.40 mg·kg-1DW,不同产地、种类及不同采集年份的样品中总Hg含量存在明显差异;同一牛肝菌菌盖、菌柄总Hg含量比(Q(C/S))在0.28~4.08,92%的样品Q(C/S)1,表明多数样品中菌盖对Hg的富集能力强于菌柄。根据GB 2762—2012规定的食用菌及其制品中总Hg含量限量标准(≤0.1 mg·kg-1),发现所有测试样品的总Hg含量均超标;根据PTWI标准,假设成年人(60 kg)每周食用300 g新鲜牛肝菌,则多数样品Hg摄入量低于允许摄入量,无安全风险,而少数样品Hg摄入量高于允许摄入量,食用有一定的潜在风险。同时,牛肝菌总Hg含量与种类、产地、采集时间等因素密切相关,采食及安全评价需综合考虑这些因素。     

Biogenic and Risk Elements in Wines from the Slovak Market with the Estimation of Consumer Exposure

Wine consumption delivers macroelements and microelements necessary for the proper metabolism. On the other hand, wine can be an important source of toxic metals. The aim of this study was to estimate the concentrations of Ca, Cd, Cu, Fe, Hg, Mg, Ni, Pb, and Zn in the Slovak and non-Slovak wines. The concentration of metals was evaluated with respect to the type, the alcohol content, and the age of Slovak wine. The general scheme of concentrations found was as follows Ca > Mg > Fe > Zn > Pb > Cd > Ni > Cu > Hg. The type of wine and the alcohol content do not have a significant impact on metal concentrations. Also, the age of wine has no influence on the mean concentration of metals, except for Zn. Metal concentrations in Slovak and non-Slovak wines indicate similar contents of metals, except for Ni. The contribution to both dietary reference values (DRVs) and provisional tolerable weekly intake (PTWI) evaluations in the Slovak wine suggested low dietary exposure to Ca, Cu, Fe, Mg, Ni, Zn, Cd, Hg, and Pb, respectively. However, we do not suggest that the consumption of all Slovak wines is healthy. The maximum Pb concentrations in Slovak wines exceed the maximum permitted level proposed by the European Commission. This might be proved by the results of the margin of the exposure (MOE) value evaluation in the samples containing the maximum Pb concentrations, showing a high risk of CKD and SBP in high and extreme consumption groups.     

The crystal structure of 6-epi-desacetyllaurenobiolide,a germacra-1(10),4-diene-12,8α-olide from Montanoa grandiflora

A chloroform extract of Montanoa grandiflora afforded a novel 6β-hydroxy-germacradien-8,12-olide. Its structure was shown to be 6-epi-desacetyllaurenobiolide by spectral studies, chemical transformations and single crystal X-ray diffraction. The X-ray data demonstrate that the ten-membered ring exists in the crystal in the highly unusual [₁₅D⁵,₁D¹⁴] conformation, in which the methyl group at C-4 is α-oriented and the methyl group at C-10 is β-oriented. The two double bonds are approximately parallel rather than crossed.     

Demonstration of Kynurenine Aminotransferases I and II and Characterization of Kynurenic Acid Synthesis in Oligodendrocyte Cell Line (OLN-93)

In the present study we demonstrate for the first time that both kynurenine aminotransferase (KAT) isoforms I and II are present in the permanent immature rat oligodendrocytes cell line (OLN-93). Moreover, we provide evidence that OLN-93 cells are able to synthesize kynurenic acid (KYNA) from exogenously added l-kynurenine and we characterize its regulation by extrinsic factors. KYNA production in OLN-93 cells was depressed in the presence of aminotransferase inhibitor, aminooxyacetic acid and was not affected by depolarizing agents such as 50 mM K⁺ and 4-aminopyridine. Glutamate agonists, l-glutamate and d,l-homocysteine significantly decreased KYNA production. Selective agonist of ionotropic glutamate receptors Amino-2,3-dihydro-5-methyl-3-oxo-4-isoxazolepropionic acid (AMPA) lowered KYNA production in OLN-93 cell line, whereas N-methyl-d-aspartate (NMDA) had no influence on KYNA production. Furthermore, KYNA synthesis in OLN-93 cells was decreased in a concentration-dependent manner by amino acids transported by l-system, l-leucine, l-cysteine and l-tryptophan. The role of KYNA synthesis in oligodendrocytes needs further investigation.     

Reduction of image artifacts in mice by bladder flushing with a novel double-lumen urethral catheter

In electron paramagnetic resonance imaging (EPRI), the accumulation of contrast agent in the bladder can create a very large source of signal, often far greater than that of the organ of interest. Mouse model images have become increasingly important in preclinical testing. To minimize bladder accumulation on mouse images, we developed a novel, minimally invasive, MRI/EPRI-friendly procedure for flushing a female mouse bladder. It is also applicable to other imaging techniques, for example, PET, SPECT, etc., where contrast agent accumulation in the bladder is also undesirable. A double-lumen urethral catheter was developed, using a standard IV catheter with a silicone tube extension, having a polyethylene tube threaded into the IV catheter. Flushing of the bladder provides a substantial reduction in artifacts, as shown in images of tumors in mice.     

Low endotoxic activity of lipopolysaccharides isolated from Bradyrhizobium, Mesorhizobium, and Azospirillum strains

The endotoxic activities of lipopolysaccharides (LPS) isolated from different strains of rhizobia and rhizobacteria (Bradyrhizobium, Mesorhizobium, and Azospirillum) were compared to those of Salmonella enterica sv. Typhimurium LPS. The biological activity of all the examined preparations, measured as Limulus lysate gelation, production of tumor necrosis factor (TNF), interleukin-1β (IL-1β), and interleukin-6 (IL-6), and nitrogen oxide (NO) induction in human myelomonocytic cells (line THP-1), was considerably lower than that of the reference enterobacterial endotoxin. Among the rhizobial lipopolysaccharides, the activities of Mesorhizobium huakuii and Azospirillum lipoferum LPSs were higher than those of the LPS preparations from five strains of Bradyrhizobium. The weak endotoxic activity of the examined preparations was correlated with differences in lipid A structure compared to Salmonella.     

Pharmacological profile of the "triple" monoamine neurotransmitter uptake inhibitor, DOV 102,677

1. The molecular and behavioral pharmacology of DOV 102,677 is characterized. 2. This characterization was performed using radioligand binding and neurotransmitter uptake assays targeting the monoamine neurotransmitter receptors. In addition, the effects of DOV 102,677 on extracellular neurotransmitter levels were investigated using in vivo microdialysis. Finally, the effects of DOV 102,677 in the forced swim test, locomotor function, and response to prepulse inhibition was investigated.3. DOV 102,677 is a novel, "triple" uptake inhibitor that suppresses [(3)H]dopamine (DA), [(3)H]norepinephrine (NE) and [(3)H]serotonin (5-HT) uptake by recombinant human transporters with IC(50) values of 129, 103 and 133 nM, respectively. Radioligand binding to the dopamine (DAT), norepinephrine (NET), and serotonin (SERT) transporters is inhibited with k (i) values of 222, 1030, and 740 nM, respectively. DOV 102,677 (20 mg/kg IP) increased extracellular levels of DA and 5-HT in the prefrontal cortex to 320 and 280% above baseline 100 min after administration. DA levels were stably increased for the duration (240 min) of the study, but serotonin levels declined to baseline by 200 min after administration. NE levels increased linearly to a maximum of 348% at 240 min post-dosing. Consistent with these increases in NE levels, the density of beta-adrenoceptors was selectively decreased in the cortex of rats treated with DOV 102,677 (20 mg/kg per day, PO, 35 days). 4. DOV 102,677 dose-dependently reduced the amount of time spent immobile by rats in the forced swim test, a model predictive of antidepressant activity, with a minimum effective dose (MED) of 20 mg/kg and a maximal efficacy comparable to imipramine. This decrease in immobility time did not appear to result from increased motor activity. Further, DOV 102,677 was as effective as methylphenidate in reducing the amplitude of the startle response in juvenile mice, without notably altering motor activity. 5. In summary, DOV 102,677 is an orally active, "balanced" inhibitor of DAT, NET and SERT with therapeutic versatility in treating neuropsychiatric disorders beyond depression.