Structural studies on HCN oligomers

Summary NMR spectral studies on the HCN oligomers suggest the presence of carboxamide and urea groupings. The release of CO₂, H₂O, HCN, CH₃CN, HCONH₂ and pyridine on pyrolysis is consistent with the presence of these groupings as well as carboxylic acid groups. No basic primary amine groupings could be detected with fluorescamine. Hydrazinolysis of the HCN oligomers releases 10% of the amino acids normally released by acid hydrolysis. The oligomers give a positive biuret test but this is not due to the presence of peptide bonds. There is no conclusive evidence for the presence of peptide bonds in the HCN oligomers. No diglycine was detected on partial hydrolysis of the HCN oligomers at pH 8.5 suggesting that HCN oligomers were not a source of prebiotic peptides.Chemical Evolution 38. For the previous papers see Ferris JP, Rao RV, Newton TA (1979). J Org Chem 44:4378–4381, 4381–4385; Ferris JP, Edelson EH, Mount NM, Sullivan AE (1979) J Mol Evol 13:317–330     

Single tester triple test cross analysis in spring wheat

Summary Two experiments, each including the same 30 homozygous varieties of spring wheat plus one separate tester variety, were conducted in order to detect epistasis and to test and estimate the additive and dominance components of genetic variation for five quantitative traits: final plant height, spike length, number of spikelets per spike, 100-kernel weight and grain yield per plant. Epistasis played a significant role in the control of 100-kernel weight and yield per plant. There was a gratifyingly good agreement between the two independent methods (2¯B₁i — ¯f_1i — ¯P_i and 2¯B_ci — ¯F_1i) used to test the presence of epistasis. In both experiments, there was a remarkably uniform high dominance ratio for most of the traits studied indicating that this test cross design is equally sensitive to both additive and dominance genetic variation.     

Fluoxetine, 17-β estradiol or folic acid combined with intra-lateral septal infusions of neuropeptide Y produced antidepressant-like actions in ovariectomized rats forced to swim

Folic acid is antidepressant, either alone or combined with several antidepressant drugs. However, the antidepressant-like actions of folic acid combined with intra-lateral septal (LSN) infusions of neuropeptide Y (NPY) in the forced swimming test (FST) have not been tested before. Thus, systemic injections of fluoxetine (20.0 mg/kg, P < 0.05; s.c.) or 17-β estradiol (10.0 μg/rat, P < 0.05; s.c.) or oral administrations of folic acid (50.0 mg/kg, P < 0.05; 75.0 mg/kg, P < 0.05) or NPY intra-LSN (3.0 μg, P < 0.05; 3.5 μg, P < 0.05) reduced immobility of ovariectomized Wistar rats. Subthreshold doses of: folic acid (25.0 mg/kg) or 17-β estradiol (5.0 μg/rat, P < 0.05) or fluoxetine (15.0 mg/kg, P < 0.05; s.c.) combined with subthreshold doses of NPY (2.5 μg/rat, P < 0.05; intra-LSN) and these combinations produced antidepressant-like actions; which were canceled by BIBP 3226 (a NPY-Y1 receptor antagonist). It is concluded that folic acid produced antidepressant-like effects probably through the participation of the NPY Y1 receptors found in the lateral septal nuclei.     

Comparison of RFFIT tests with different standard sera and testing procedures

The World Health Organization (WHO) standard assay for determining antibody level is the rapid fluorescent focus inhibition test (RFFIT) and is used to determine the degree of immunity after vaccinatio...     

Xanthone C-glycosides isomers purified from Dryopteris ramosa (Hope) C. Chr. with bactericidal and cytotoxic prospects

Xanthones C-glycosides are plants secondary metabolites with diverse biological activities. Among the C-glycoside xanthones, the mangiferin (MF) is of widespread occurrence in plants while isomangiferin (IsoMF) is not very common. For the present study mangiferin (MF) and isomangiferin (IsoMF) were isolated from Dryopteris ramosa. The antibacterial potential of MF and IsoMF was evaluated by using agar well diffusion method while cytotoxic properties of MF and IsoMF were assessed by brine shrimp lethality test (BSLT). The antibacterial potential of MF and IsoMF increases in dose dependent manner. The minimum inhibitory concentration (MIC) indicated strong antibacterial potential of MF against Salmonella setubal (125 µg/mL) and Bacillus subtilis (125 µg/mL) while MF showed weak antibacterial potential against Escherichia coli (500 µg/mL). On the other hand the IsoMF showed better antibacterial potential against all the tested strain including Escherichia coli (MIC = 250 µg/mL). The MF and IsoMF showed poor cytotoxicity towards Brine shrimp nauplii as indicated by their LD₅₀ (969.77 ± 0.67 and 768.92 ± 0.81 µg/mL respectively). The present study has highlighted the antibacterial potential of MF and IsoMF. Further evaluation of these two isomeric compounds may prove to be the future remedies for various bacterial infections and other human ailments.     

建立膜抗原荧光抗体试验评价北京株冻干水痘疫苗免疫效果

为了建立用于水痘疫苗接种后血清中特异性抗体检测的膜抗原荧光抗体(FAMA)法,并对接种水痘疫苗后儿童血清中水痘特异性抗体进行检测,评价北京株水痘疫苗的免疫效果。以水痘带状疱疹病毒(VZV)感染细胞作为抗原制备成固定抗原玻片,以异硫氰酸荧光素(FITC)标记的羊抗人IgG作为二抗建立FAMA法,并对该法的敏感性、特异性进行验证。运用此法对不同剂量北京株水痘疫苗接种后儿童血清中特异性抗体进行检测,分析儿童血清中水痘特异性抗体水平以及免后抗体阳转率,并与Oka株水痘疫苗进行比较。结果显示,FAMA法敏感性可达0.0196IU/ml,特异性好。应用此法检测300名观察者免前免后双份血清样本中抗VZVIgG,易感者中北京株水痘疫苗原苗(39810PFU/0.5ml)、2000PFU/0.5ml、500PFU/0.5ml接种组儿童血清免后抗体阳转率分别为100%、98.77%、85.42%,抗体几何平均滴度(GMT)分别为36.4、34.3、18.6,原苗与2000PFU间的抗体阳转率和GMT均无显著性差异(P>0.05),但原苗与500PFU、2000PFU与500PFU间的抗体阳转率和GMT均有显著性差异(P<0.05)。对照国产、进口Oka株水痘疫苗接种后抗体阳转率分别为95.35%、96.97%,抗体GMT分别为13.3、16.0,不同剂量北京株疫苗抗体阳转率与国产、进口Oka株疫苗相比,差别无显著性(P>0.05),但北京株疫苗原?