Effect of different dietary protein levels and amino acids supplementation patterns on growth performance, carcass characteristics and nitrogen excretion in growing-finishing pigs

Background:This study was conducted to determine the effects of different dietary protein levels and amino acids supplementation patterns in low protein diets on the growth performance,carcass characteristics and nitrogen excretion in growing-finishing pigs.Forty-two barrows(25.00±0.39 kg)were randomly assigned to 7 diets.Diet 1:the high crude protein diet with balanced for 10 essential amino acids(EAAs).Diet 2:the medium crude protein diet with 2%(approx)decreased protein level of Diet 1 and balanced 10 EAAs.Diet 3:the low crude protein diet with 4%decreased protein level of Diet 1 and balanced 10 EAAs.The protein levels of Diet 4,5,6 and 7 were the same as that of Diet 3.Diet 4 was only balanced for lysine(Lys),methionine(Met),threonine(Thr)and tryptophan(Trp);Diet 5 and 6 were further supplemented with extra isoleucine(Ile)or valine(Val),respectively;Diet 7 was further supplemented with extra Ile+Val.Results:Over the 112 days trial,the reduction of dietary protein by 2%or 4%with balanced10 EAAs significantly decreased nitrogen excretion(P<0.05),but had no effects on growth performance and carcass characteristics(P>0.05).In low protein diet,Val supplementation significantly increased body weight gain at 25–50 kg phase(P<0.05),while Ile supplementation at 75–100 kg phase and 100–125 kg phase significantly reduced the ratio of feed to gain(P<0.05).No effect of different dietary protein levels and amino acids supplementation patterns in low protein diets on carcass characteristics was observed(P>0.05).The total N excretion of pigs supplemented with only Lys,Met,Thr and Trp was numerically higher than that of pigs fed with extra Ile,or Val,or Ile+Val diets.Conclusion:In low protein diet,Val is more required than Ile in the early growing phage(25–50 kg),while Ile becomes more required in the late growing and finishing phage(75–125 kg).

60岁以上乳腺癌的乳腺X线影像学表现及病灶微钙化与年龄的相关性研究

目的:比较年龄60岁以上老年乳腺癌与60岁以下非老年乳腺癌患者的乳腺X线影像学表现并分析病灶微钙化阳性率与年龄的相关性。方法:回顾性分析2012年6月至2013年4月天津医科大学肿瘤医院1959例经病理确诊的乳腺癌患者的乳腺X线影像学资料,以60岁为界分为老年组(n=512)和非老年组(n=1447)并进行统计学分析。结果:老年组和非老年组中高密度肿块的患者分别占73.0%(330/452)和46.0%(464/1008),等/低密度肿块的患者分别占27.0%(122/452)和54.0%(544/1008),两组比较差异具有统计学意义(P<0.05)。老年组和非老年组中病灶微钙化阳性率分别为34.8%(178/512)和41.7%(603/1447),两组比较差异具有统计学意义(P<0.05)。1959例患者根据年龄<30岁、30~39岁、40~49岁、50~59岁、60~69岁和年龄≥70岁进行分组,病灶微钙化阳性率分别占58.8%(10/17)、42.8%(74/173)、41.0%(259/632)、41.6%(260/625)、38.2%(137/359)和26.8%(41/153),随着年龄增长病灶微钙化阳性率整体呈下降趋势,差异具有统计学意义(P=0.008)。结论:老年组与非老年组乳腺X线影像学表现中的肿块密度及病灶微钙化阳性率不同,病灶微钙化阳性率呈随年龄增长而降低的趋势。

Identification of a senescence-related protease in coriander leaves

Senescence-related protease may play an important role in leaf senescence. By improved SDS-Gela-tin-PAGE assay, a 63 ku senescence-related protease (63 SRP) in coriander leaves was identified. Activity of 63 SRP was increased in parallel to the advance of coriander leaf senescence, and inhibited by treating the leaf with gibberellic acid, and enhanced by ethylene treatment. The 63 SRP was suggested to be a serine protease based on the fact that its activity was inhibited by the protease inhibitor PMSF. The optimal temperature for the activity of the 70 ku protease was 50°C. The maximal activity was observed at pH 6-9, some activity could be observed on the gel slices incubated at pH 5 or 11. The 63 SRP was partly purified by the way of ammonium sulfate precipitation and then gel slicing after gel elec-trophoresis.

Rapid identification and isolation of neuraminidase inhibitors from mockstrawberry(Duchesnea indica Andr.) based on ligand fishing combined with HR-ESI-Q-TOF-MS

Neuraminidase inhibitors(NAIs)are the mainstay antiviral drugs against influenza infection.In this study,a ligand fishing protocol was developed to screen NAIs using neuraminidase immobilized magnetic beads(NA-MB).After verifying the feasibility of NA-MB with an artificial mixture including NA inhibitors and non-inhibitors,the developed ligand fishing protocol was applied to screen NAIs from the crude extracts of Duchesnea indica Andr.Twenty-four NA binding compounds were identified from the normal butanol(n-BuOH)extract of D.indica as potential NAIs by high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry(HPLC-Q-TOF-MS)assisted with Compound Structure Identification(CSI):FingerID,including 12 ellagitannins,4 brevifolin derivatives,3 ellagic acid derivatives,and 4 flavonoids.Among them,9 compounds were isolated and tested for in vitro NA inhibitory activities against NA from Clostridium perfringens,and from oseltamivir sensitive and resistant influenza A virus strains.The results indicate that compound B23 has the NA inhibitory activities in both the oseltamivir sensitive and resistant viral NA,with half maximal inhibitory concentration(IC50)values of 197.9 and 125.4μmol/L,respectively.Moreover,B23 can obviously reduce the replication of oseltamivir sensitive and resistant viruses in Madin-Darby canine kidney(MDCK)cells at the concentrations of 40 and 200μmol/L.

Dietary protein levels and amino acid supplementation patterns alter the composition and functions of colonic microbiota in pigs

Different dietary nitrogen(N) patterns may have different effects on gut microbiota.To investigate the effects of different crude protein(CP) levels or essential amino acids(EAA) supplementation patterns on the structure and functions of colonic microbiota,42 barrows(25±0.39 kg) were randomly assigned to 7 dietary treatments including:diet 1,a high CP diet with balanced 10 EAA;diet 2,a medium CP diet with approximately 2% decreased CP level from diet 1 and balanced 10 EAA;diets 3,4,5,6 and 7,low CP diets with 4% decreased CP level from diet 1.Specifically,diet 3 was only balanced for Lys,Met,Thr and Trp;diets 4,5 and 6 were further supplemented with IIe,Val and IIe+Val on the basis of diet 3,respectively;and diet 7 was balanced for 10 EAA.Results over a 110-d trial showed that reducing the CP level by 2% or4% dramatically decreased N intake and excretion(P <0.05) in the presence of balanced 10 EAA,which was not observed when altering the EAA supplementation patterns in low CP diet(-4%).With balanced10 EAA,2% reduction in dietary CP significantly reduced Firmicutes-to-Bacteroidetes(F:B) ratio and significantly elevated the abundance of Prevotellaceae NK3 B31(P <0.05);whereas 4% reduction evidently increased the abundances of Proteobacteria,Succinivibrio and Lachnospiraceae XPB1014(P <0.05).Among the 5 low CP diets(-4%),supplementation with Ile,or Val+Ile,or balanced 10 EAA increased F:B ratio and the abundance of Proteobacteria.In addition,the predicted functions revealed that different CP levels and EAA balanced patterns dramatically altered the mRNA expression profiles of N-metabolizing genes,the "N and energy metabolism" pathways or the metabolism of some small substances,such as amino acids(AA) and vitamins.Our findings suggested that reducing the dietary CP levels by 2% to 4% with balancing 10 EAA,or only further supplementation with Ile or Val+Ile to a low protein diet(-4%) reduced the N contents entering the hindgut to various degrees,altered the abundances of N-metabolizing bacteria,and improved the abilities of N utilization.