Overlapping and distinct roles of STAT4 and T-bet in the regulation of T cell differentiation and allergic airway inflammation

T-bet and STAT4 play critical roles in helper T cell differentiation, especially for Th1 cells. However, it is still unknown about the relative importance and redundancy of T-bet and STAT4 for Th1 differentiation. It is also unknown about their independent role of T-bet and STAT4 in the regulation of allergic airway inflammation. In this study, we addressed these issues by comparing T-bet-deficient (T-bet(-/-)) mice, STAT4(-/-) mice, and T-bet- and STAT4-double-deficient (T-bet(-/-)STAT4(-/-)) mice on the same genetic background. Th1 differentiation was severely decreased in T-bet(-/-) mice and STAT4(-/-) mice as compared with that in wild-type mice, but Th1 differentiation was still observed in T-bet(-/-) mice and STAT4(-/-) mice. However, Th1 cells were hardly detected in T-bet(-/-)STAT4(-/-) mice. In contrast, the maintenance of Th17 cells was enhanced in T-bet(-/-) mice but was reduced in STAT4(-/-) mice and T-bet(-/-)STAT4(-/-) mice. In vivo, Ag-induced eosinophil and neutrophil recruitment into the airways was enhanced in T-bet(-/-) mice but was attenuated in STAT4(-/-) mice and T-bet(-/-)STAT4(-/-) mice. Ag-induced IL-17 production in the airways was also diminished in STAT4(-/-) mice and T-bet(-/-)STAT4(-/-) mice. These results indicate that STAT4 not only plays an indispensable role in T-bet-independent Th1 differentiation but also is involved in the maintenance of Th17 cells and the enhancement of allergic airway inflammation.     

Expression and tyrosine phosphorylation of Cbl regulates macrophage chemokinetic and chemotactic movement

Primary macrophages isolated from hck(-/-)fgr(-/-) mice display altered morphology and F-actin cytoskeletal structures and reduced migration. The ability of phorbol myristyl acetate (PMA), a protein kinase C activator that has been reported to increase macrophage spreading and carcinoma cell motility, to rescue these hck(-/-)fgr(-/-) defects was tested. Although PMA-treated wild-type and hck(-/-)fgr(-/-) macrophages exhibited a similar flattened, spread phenotype, PMA did not rescue the hck(-/-)fgr(-/-) macrophage migration defect. Instead, both PMA-treated wild type and hck(-/-)fgr(-/-) macrophages were defective in spontaneous and chemotactic migration and tyrosine phosphorylation of the Cbl protooncoprotein was decreased in both. Moreover, c-cbl(-/-) macrophages displayed the same impairment of motility as hck(-/-)fgr(-/-) macrophages and a similar morphology with less polarization and more dorsal ruffling than wild-type macrophages. As Hck and Fgr expression and activity were not decreased in c-cbl(-/-) macrophages, these results suggest that Cbl is likely to be an important downstream mediator of the Src family kinase-regulated macrophage motility pathway.     

Total synthesis of globotriaosyl-E and Z-ceramides and isoglobotriaosyl-E-ceramide

Stereoselective, total synthesis of O-alpha-D-galactopyranosyl-(1----4) -O-beta-D-galactopyranosyl-(1----4)-O-beta-D-glucopyranosyl-(1----1)-N -tetracosanoyl-[2S,3R,4E (and 4Z)]-sphingenine and O-alpha-D -galactopyranosyl-(1----3)-O-beta-D-galactopyranosyl-(1----4)-O-beta-D -glucopyranosyl-(1----1)-N-tetracosanoyl-(2S,3R,4E)-sphin gen ine was achieved by using O-(2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl) -(1----4)-O-(2,3,6-tri-O-acetyl-beta-D-galactopyranosyl)-(1----4)-2,3,6- tri-O-acetyl-alpha-D-glucopyranosyl trichloroacetimidate, O-(2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl) -(1----4)-O-(2,3,6-tri-O-acetyl-beta-D-galactopyranosyl)-(1----4)-2,3,6- tri-O-acetyl-alpha (and beta)-D-glucopyranosyl fluoride, and O-(2,3,4,6-tetra-O-acetyl-alpha-D -galactopyranosyl)-(1----3)-O-(2,3,6-tri-O-acetyl-beta-D-galactopyran osyl)-(1----4)-2,3,6-tri-O-acetyl-alpha-D-glucopyranosyl trichloroacetimidate.     

Benzyladenine and derivatives-their significance and interconversion in plants

Recently benzyladenine has been isolated as a natural cytokinin from a number of plants. The natural occurrence of this cytokinin will change the attitude with which physiologists view this hormone. This review attempts to put into context what is known about this cytokinin and its derivatives and to compare and contrast its metabolism and the function and physiological action of its various metabolites. Nothing is known about the biosynthesis of benzyladenine. Its structure would suggest that its biosynthetic pathway may differ considerably from that of zeatin and iso-pentenyladenine.Abbreviations Ade adenine - Ado adenosine - BA benzyladenine - [9R]BA BA ribonucleoside - [9R-MP]BA BA nucleotide - [9R-DP]BA BA dinucleotide - [9R-TP]BA BA trinucleotide - [3G]BA BA 3 glucoside - [7G]BA BA 7 glucoside - [9G]BA BA 9 glucoside - [9R-G]BA BA 9-ribosylglucoside - [9Ala]BA BA alanine-conjugate - (2OH)BA BA ortho-OH - (2OH)[9R]BA BA ortho-Oh-riboside - KN kinetin - [9R]KN KN ribonucleoside - DHZ dihydrozeatin - Z trans-zeatin - [9R]Z zeatin ribonucleoside - [7G]Z zeatin-7-glucoside - [9G]Z zeatin-9-glucoside - [9Ala]Z zeatin alanine-conjugate - (OG)[9R]Z O-glucoside of zeatin ribonucleoside - [9R-MP]Z zeatin nucleotide - iP iso-pentenyladenine - [9R]iP iP ribonucleoside     

Energy cost of walking and running at extreme uphill and downhill slopes.

The costs of walking (Cw) and running (Cr) were measured on 10 runners on a treadmill inclined between -0.45 to +0.45 at different speeds. The minimum Cw was 1.64 +/- 0.50 J. kg(-1). m(-1) at a 1.0 +/- 0.3 m/s speed on the level. It increased on positive slopes, attained 17.33 +/- 1.11 J. kg(-1). m(-1) at +0.45, and was reduced to 0.81 +/- 0.37 J. kg(-1). m(-1) at -0.10. At steeper slopes, it increased to reach 3.46 +/- 0.95 J. kg(-1). m(-1) at -0.45. Cr was 3.40 +/- 0.24 J. kg(-1). m(-1) on the level, independent of speed. It increased on positive slopes, attained 18.93 +/- 1.74 J. kg(-1). m(-1) at +0.45, and was reduced to 1.73 +/- 0.36 J. kg(-1). m(-1) at -0.20. At steeper slopes, it increased to reach 3.92 +/- 0.81 J. kg(-1). m(-1) at -0.45. The mechanical efficiencies of walking and running above +0.15 and below -0.15 attained those of concentric and eccentric muscular contraction, respectively. The optimum gradients for mountain paths approximated 0.20-0.30 for both gaits. Downhill, Cr was some 40% lower than reported in the literature for sedentary subjects. The estimated maximum running speeds on positive gradients corresponded to those adopted in uphill races; on negative gradients they were well above those attained in downhill competitions.     

Sex and limb-specific ischemic reperfusion and vascular reactivity

With little known regarding sex and limb heterogeneity, we investigated vascular reactivity and ischemic reperfusion (IR) in the upper and lower extremities of 15 healthy men (26 +/- 2 yr) and women (23 +/- 1 yr). Doppler ultrasound was used to evaluate IR and flow-mediated dilation (FMD) after suprasystolic cuff occlusion in both the arm [brachial artery (BA)] and the leg [popliteal artery (PA)]. Cumulative IR [area under the curve (AUC)], normalized for muscle mass, revealed no sex-related differences in either limb (forearm: men 38 +/- 3 and women 44 +/- 4 ml/100 g; lower leg: men 12 +/- 2 and women 14 +/- 2 ml/100 g), while both groups revealed a greater IR per unit of arm muscle mass (AUC) compared with the lower leg (P < 0.05). The BA and PA were smaller in women (BA 0.31 +/- 0.1, PA 0.47 +/- 0.1 cm) than in men (BA 0.41 +/- 0.1, PA 0.6 +/- 0.2 cm). Absolute FMD/shear rate revealed attenuated vascular function in the PA of the women [women 3.3 +/- 0.6, men 5.0 +/- 0.8 (all x10(-6)) cm/s(-1).s] and no sex difference in the BA [women 1.2 +/- 0.2, men 1.6 +/- 0.1 (all x10(-6)) cm/s(-1).s]. In both sexes the PA demonstrated greater vascular reactivity than the BA. Thus vascular reactivity in healthy young people is greater in the legs, regardless of sex, and women have vascular function similar to men in the upper extremities but appear to have poorer vascular function normalized for shear rate in the lower extremities.     

Syntheses and Herbicidai Activities of Phenoxypyrimidines and Phenoxytriazines

Series of phenoxypyrimidines and phenoxytriazines were prepared to be evaluated as herbicides. Among them, 2-(2,6-dichlorophenoxy)-pyrimidine (XV), 2-phenoxy-4,6-dimethyl- pyrimidine (XVII), 2-(3-methyl-4-chlorophenoxy)-4,6-bis(ethylamino)-5-triazine (LIV), 2-(2,4-dichlorophenoxy)-4,6-bis(ethylamino)-s-triazine (LVIII), and 2-(2,6-dichlorophenoxy)-4,6-bis(ethylamino)-s-triazine (LX) showed high pre-emergent herbicidai activity to radish. On the other hand, 2-chloro-4-(2,6-dichlorophenoxy)-6-methylpyrimidine (XXX) revealed high efficiency to millet. Some structure-activity relationship is discussed.     

Glucose and lactate turnover and gluconeogenesis in chronic metabolic acidosis and alkalosis in normal and diabetic dogs

The turnover rate of glucose, the irreversible disposal rate of lactate, and the rate of gluconeogenesis from lactate were calculated by tracer methods in four normal and four alloxan-diabetic dogs under control conditions as well as in chronic, stable metabolic acidosis and alkalosis. Acidosis was produced by feeding dogs 0.8-1 g.kg-1.day-1NH4Cl over 1 week, alkalosis was produced by feeding dogs a chloride-free diet and injections of furosemide. Mean plasma pH in the three states were 7.28 +/- 0.013, 7.40 +/- 0.024, and 7.51 +/- 0.015 in normal dogs, and 7.22 +/- 0.025, 7.42 +/- 0.009, and 7.49 +/- 0.002 in the diabetic dogs. Respective mean plasma bicarbonate levels were 14.6 +/- 0.88, 22.0 +/- 0.80, and 32.4 +/- 1.88 mequiv. in normal dogs, and 12.3 +/- 1.30, 22.6 +/- 0.66, and 35.0 +/- 1.14 mequiv. in diabetic animals. In normal dogs shifts in acid-base balance had no effect on the level of plasma glucose or the turnover rate of glucose. In diabetic dogs plasma glucose level was significantly elevated by alkalosis. Plasma lactate was positively correlated with plasma pH (r = 0.69, p less than 0.01) and was in general higher in diabetic than in normal animals. The increment in concentration was due to a decreased clearance of lactate from the plasma. The irreversible disposal rate was not changed by the acid-base status. Whereas a larger fraction of lactate removed from the plasma appeared in glucose in diabetic animals, this fraction was not changed significantly by shifts in the acid-base status.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of fasting on insulin action and glucose kinetics in lean and obese men and women

The development of insulin resistance in the obese individual could impair the ability to appropriately adjust metabolism to perturbations in energy balance. We investigated a 12- vs. 48-h fast on hepatic glucose production (R(a)), peripheral glucose uptake (R(d)), and skeletal muscle insulin signaling in lean and obese subjects. Healthy lean [n = 14; age = 28.0 +/- 1.4 yr; body mass index (BMI) = 22.8 +/- 0.42] and nondiabetic obese (n = 11; age = 34.6 +/- 2.3 yr; BMI = 36.1 +/- 1.5) subjects were studied following a 12- and 48-h fast during 2 h of rest and a 3-h 40 mUxm(-2)xmin(-1) hyperinsulinemic-euglycemic clamp (HEC). Basal glucose R(a) decreased significantly from the 12- to 48-h fast (lean 1.96 +/- 0.23 to 1.63 +/- 0.15; obese 1.23 +/- 0.07 to 1.07 +/- 0.07 mgxkg(-1)xmin(-1); P = 0.004) and was equally suppressed during the HEC after both fasts. The increase in glucose R(d) during the HEC after the 12-h fast was significantly decreased in lean and obese subjects after the 48-h fast (lean 9.03 +/- 1.17 to 4.16 +/- 0.34, obese 6.10 +/- 0.77 to 3.56 +/- 0.30 mgxkg FFM(-1)xmin(-1); P < 0.001). After the 12- but not the 48-h fast, insulin-stimulated AKT Ser(473) phosphorylation was greater in lean than obese subjects. We conclude that 1) 48 h of fasting produces a marked decline in peripheral insulin action, while suppression of hepatic glucose production is maintained in lean and obese men and women; and 2) the magnitude of this decline is greater in lean vs. obese subjects.     

Involvement of H- and N-Ras isoforms in transforming growth factor-beta1-induced proliferation and in collagen and fibronectin synthesis

Transforming growth factor beta1 (TGF-beta1) has a relevant role in the origin and maintenance of glomerulosclerosis and tubule-interstitial fibrosis. TGF-beta and Ras signaling pathways are closely related: TGF-beta1 overcomes Ras mitogenic effects and Ras counteracts TGF-beta signaling. Tubule-interstitial fibrosis is associated to increases in Ras, Erk, and Akt activation in a renal fibrosis model. We study the role of N- and H-Ras isoforms, and the involvement of the Ras effectors Erk and Akt, in TGF-beta1-mediated extracellular matrix (ECM) synthesis and proliferation, using embrionary fibroblasts from double knockout (KO) mice for H- and N-Ras (H-ras(-/-)/N-ras(-/-)) isoforms and from heterozygote mice (H-ras(+/-)/N-ras(+/-)). ECM synthesis is increased in basal conditions in H-ras(-/-)/N-ras(-/-) fibroblasts, this increase being higher after stimulation with TGF-beta1. TGF-beta1-induced fibroblast proliferation is smaller in H-ras(-/-)/N-ras(-/-) than in H-ras(+/-)/N-ras(+/-) fibroblasts. Erk activation is decreased in H-ras(-/-)/N-ras(-/-) fibroblasts; inhibition of Erk activation reduces fibroblast proliferation. Akt activation is higher in double KO fibroblasts than in heterozygotes; inhibition of Akt activation also inhibits ECM synthesis. We suggest that H- and N-Ras isoforms downregulate ECM synthesis, and mediate proliferation, in part through MEK/Erk activation. PI3K-Akt pathway activation may be involved in the increase in ECM synthesis observed in the absence of H- and N-Ras.     

Distribution and metabolism of ingested NO3- and NO2- in germfree and conventional-flora rats.

Germfree and conventional-flora Sprague-Dawley rats were fed sodium nitrate or sodium nitrite in their drinking water (1,000 microgram/ml), and various organs, tissues, and sections of the intestinal tract were assayed for nitrate (NO3-) and nitrite (NO2-) by a spectrophotometric method. When fed NO3-, germfree rats had chemically detectable levels of NO3- (only) in the stomach, small intestine, cecum, and colon. Conventional-flora rats fed NO3- had both NO3- and NO2- in the stomach, but only NO3- in the small intestine and colon. When fed NO2-, germfree rats had both NO3- and NO2- in the entire gastrointestinal tract. Conventional-flora rats fed NO2- had both ions in the stomach and small intestine, but only NO3- in the large intestine. Conventional-flora rats fed NO3- or NO2- had lower amounts of these ions in the gastrointestinal tract than comparably fed germfree rats. Control (non-NO3- or NO2--fed) germfree and conventional-flora rats had trace amounts of NO3- (only) in their stomachs and bladders. These results, in conjunction with various in vitro studies with intestinal contents, suggest that NO3- or NO2- reduction is a function of the normal bacterial flora, whereas NO2- oxidation is attributable to the mammalian host. In addition, the distribution of these ions after their ingestion appears more widespread in the body than previously thought.     

Synthesis of gossypol atropisomers and derivatives and evaluation of their anti-proliferative and anti-oxidant activity

Gossypol 1, gossypolone 2, and a series of bis 3 and half Schiff's bases 4 of gossypol were synthesised and tested for anti-proliferative and anti-oxidant activity. (-)-Gossypol (-)-1 was the most potent inhibitor of the proliferation of the HPV-16 keratinocyte cell line (using an MTT viability assay) with a GI50 of 4.8 microM. The bis Schiff's base of (-)-gossypol with L-tyrosine ethyl ester (-)-3b was the most potent inhibitor of iron/ascorbate dependent lipid peroxidation (using the thiobarbituric acid test), with an IC50 of 11.7 microM, with (-)-gossypol being the next most potent of the series, with an IC50 of 13.1 microM. The results from these initial assays suggest that gossypol, as either a racemic mixture rac-1, or the individual atropisomers (-)-1 or (+)-1, has potential for the treatment of psoriasis.     

Stereoselective synthesis of 2,3,7-trimethylcyclooctanone and related compounds and determination of their relative and absolute configurations by the MalphaNP acid method

The copper/chiral phosphoramidite (L(1))-catalyzed conjugate addition of dimethylzinc to cycloocta-2,7-dienone 4, followed by the methylation of the intermediate enolate, yielded a single isomer of 7,8-dimethylcyclooct-2-enone (+)-5. Compound (+)-5 was subjected to the second conjugate addition with ent-L(1) giving only one stereoisomer of 2,3,7-trimethylcyclooctanone (+)-6, which was converted to 2,3,7-trimethylcyclooctanol 7. To determine the relative and absolute configurations of these compounds, the (1)H NMR anisotropy method using (S)-(+)-2-methoxy-2-(1-naphthyl)propionic acid {(S)-(+)-MalphaNP acid} 1 was applied. Racemic alcohol (+/-)-7 was esterified with (S)-(+)-MalphaNP acid 1 yielding diastereomeric esters, which were efficiently separated by HPLC on silica gel affording the first-eluted MalphaNP ester (-)-10a and the second-eluted one (-)-10b. The relative and absolute configurations of ester (-)-10a were determined to be (S;1R,2S,3R,7S) by analyzing the (1)H and (13)C NMR spectra of (-)-10a and (-)-10b, especially their HSQC-TOCSY and NOESY spectra, and by applying the MalphaNP anisotropy method. The alcohol 7 formed from (+)-6 was similarly esterified with (S)-(+)-MalphaNP acid 1 yielding an MalphaNP ester, which was identical with (-)-10a, and the relative and absolute configurations of 2,3,7-trimethylcyclooctanone (+)-6 were determined to be (2S,3R,7S).     

Synthesis and biological evaluation of L- and D-configuration 1,3-dioxolane 5-azacytosine and 6-azathymine nucleosides

Novel L- and D-configuration dioxolane 5-azacytosine and 6-azathymine nucleosides have been synthesized and evaluated for biological activity. (-)-(2S,4S)-1-[2-(Hydroxymethyl)-1,3-dioxolan-4-yl]-5-azacytosine (6) showed significant activity against HBV, whereas the D-configuration analogue (14) has been found to exhibit potent anti-HIV activity.     

Lipolysis and lipid oxidation in cirrhosis and after liver transplantation

On the basis of the finding that plasma glycerol concentration is not controlled by clearance in healthy humans, it has been proposed that elevated plasma free fatty acid (FFA) and glycerol concentrations in cirrhotic subjects are caused by accelerated lipolysis. This proposal has not been validated. We infused 10 volunteers, 10 cirrhotic subjects, and 10 patients after orthotopic liver transplantation (OLT) with [1-(13)C]palmitate and [(2)H(5)]glycerol to compare fluxes (R(a)) and FFA oxidation. Cirrhotic subjects had higher plasma palmitate (52%) and glycerol (33%) concentrations than controls. Palmitate R(a) was faster (1.45+/-0.18 vs. 0.85+/-0.17 micromol x kg(-1) x min(-1)) but glycerol R(a) and clearance slower (1.20+/-0.09 vs. 1.90+/-0.24 micromol x kg(-1) x min(-1) and 21.2+/-1.2 vs. 44.7+/- 4.9 ml x kg(-) x h(-1), respectively) than in controls. After OLT, plasma palmitate and glycerol concentrations and palmitate R(a) did not differ, but glycerol R(a) (1.16+/-0.11 micromol x kg(-1) x min(-1)) and clearance (26.7+/-2.4 ml x kg(-1) x h(-1)) were slower than in controls. We conclude that 1) impaired reesterification, not accelerated lipolysis, elevates FFA in cirrhotic subjects; 2) normalized FFA after OLT masks impaired reesterification; and 3) plasma glycerol concentration poorly reflects lipolytic rate in cirrhosis and after OLT.     

Roles of MGMT and MLH1 proteins in alkylation-induced apoptosis and mutagenesis

To examine involvement of mismatch repair system in alkylation-induced apoptosis and mutagenesis, cell lines defective in the Mgmt gene encoding a DNA repair enzyme, O(6)-methylguanine-DNA methyltransferase, and/or the Mlh1 gene encoding a protein involved in mismatch repair were established from gene-targeted mice. Mgmt(-/-) cells are hypersensitive to the killing effect of N-methyl-N-nitrosourea (MNU) and this effect of MNU was overcome by introducing an additional mutation in the Mlh1 gene. Mgmt(-/-)Mlh1(-/-) cells are more resistant to MNU than are wild-type cells. When the human Mgmt cDNA sequence with a strong promoter was introduced, the wild-type cells acquired the same high level of resistance to MNU as that of Mgmt(-/-)Mlh1(-/-) cells. Although no apparent increase in MNU-induced mutant frequency was observed in such methyltransferase-overproducing wild-type cells, mutant frequency of Mgmt(-/-)Mlh1(-/-) cells became 10-fold higher after being treated with MNU. Mgmt(-/-)Mlh1(+/-) cells carrying approximately half the normal level of MLH1 protein showed a normal level of spontaneous mutant frequency, yet were still highly responsive to the mutagenic effect of the alkylating carcinogen. This haploinsufficient character of Mlh1 mutation was also observed in cell survival assays; Mgmt(-/-)Mlh1(+/-) cells were as resistant to MNU as were Mgmt(-/-)Mlh1(-/-) cells. While caspase-3 was induced in Mgmt(-/-)Mlh1(+/+) cells after treatment with MNU, no induction occurred in Mgmt(-/-)Mlh1(+/-) cells or in Mgmt(-/-)Mlh1(-/-) cells. The cellular content of MLH1 protein seems to be critical for determining if damaged cells enter into either a death or mutation-inducing pathway. The haploinsufficient phenotype of Mlh1-heterozygous cells may be explained by competition in heterodimer formation between MLH1 homologues.     

Latimeria chalumnae and its pedigree

Synopsis Latimeria is the product of a long coelacanth lineage, usually viewed as having changed very little. In this paper a classification of better known coelacanth genera is proposed based on a cladistic computer analysis of 56 morphological characters. Biometrical data are then matched with the classification to explore the possibility of identifying subtle change. It is concluded that throughout coelacanth history there have been changes in the structure of the vertebral column involving an overall increase in the number of vertebral elements, and a consequent crowding of these elements within the abdominal region. These changes may be associated with increasing lobation of the second dorsal and anal fins. In the skull, parameters involving the intracranial joint have also changed in such a way that the anterior part of the skull has lengthened in relation to the posterior part and this may be associated with an increase in length of the basicranial muscle.Abbreviations in text figures Ang angular - a.o.r anterior opening of th rostral organ - Art articular - ba.cr.m basicranial muscle - Basi basisphenoid - Boc basioccipital - bpt.pr basipterygoid process - c.p.l cheek pit line - De dentary - Esc extrascapular - eth.sp etmosphenoid - f.e frontoethmoid - Fr frontal - Fr.d descending process of frontal - intr. j intracranial joint - io.s interorbital septum - sc jugal sensory canal - L.e lateral ethmoid - m.Cor modified coronoid - Mm memtomeckelian - m.ot.sc medial branch of otic canal - Op operculum - o.p.l oral pit line - ot,occ otico-occipital - Pa parietal - Pa.d descending process of parietal - Par parasphenoid - pa.s parietal shield - p.Cor principal coronoid - Po postorbital - Pop preoperculum - p.o.r posterior openings of the rostral organ - Pmx premaxilla, Pre-preorbital - Pro prootic - Pro.p posterior process of prootic - Rart retroarticular - Sc.o sclerotic ossicle - So supraorbital - Soc supraoccipital - Sop suboperculum - Sp spiracular - spl splenial - Sq squamosal - Stt supratemporal - Stt.com supratemporal commissure - Stt.d descending process of supratemporal - Par.a.w ascending wing of parasphenoid - Te tectal - X level of vagus exit     

碱提工艺对茶树菇多糖形貌特征和构象及其生物活性的影响

利用传统水提及碱提的方法得到茶树菇粗多糖S-ACP和J-ACP,经CTAB法和Sephadex G-150凝胶层析法对其分离纯化,分别得到S-ACP2-1和S-ACP2-2以及J-ACP2-1和J-ACP2-2两组主要组分,用扫描电子显微镜（SEM）和原子力显微镜（AFM）对多糖的形貌进行表征并测定其体外抗氧化活性和抗肿瘤活性;对多糖S-ACP2-2、J-ACP2-2进行刚果红实验测定及圆二色谱仪（CD）分析。SEM观测结果：S-ACP2-1为较粗的表面光滑的丝状,J-ACP2-1呈较细的有少量碎屑的丝状;S-ACP2-2为较大的片状,J-ACP2-2在大的片状周围有很多细小的碎屑。AFM观测结果：碱液可以使多糖分子部分断裂成小片段。刚果红实验：S-ACP2-2、J-ACP2-2在水溶液中为自由卷曲构型。CD分析：S-ACP2-2的空间构型中有序结构较少,J-ACP2-2在水溶液中为无序构型。对比4种多糖的活性,碱液作用的多糖J-ACP2-2活性高于S-ACP2-2。     

14-3-3 proteins and the response to abiotic and biotic stress

14-3-3 proteins function as regulators of a wide range of target proteins in all eukaryotes by effecting direct protein-protein interactions. Primarily, interactions between 14-3-3 proteins and their targets are mediated by phosphorylation at specific sites on the target protein. Hence, interactions with 14-3-3s are subject to environmental control through signalling pathways which impact on 14-3-3 binding sites. Because 14-3-3 proteins regulate the activities of many proteins involved in signal transduction, there are multiple levels at which 14-3-3 proteins may play roles in stress responses in higher plants. In this article, we review evidence which implicates 14-3-3 proteins in responses to environmental, metabolic and nutritional stresses, as well as in defence responses to wounding and pathogen attack. This evidence includes stress-inducible changes in 14-3-3 gene expression, interactions between 14-3-3 proteins and signalling proteins and interactions between 14-3-3 proteins and proteins with defensive functions.