Simultaneous determination of human plasma protein binding of bioactive favonoids in Polygonum orientale by equilibrium dialysis combined with UPLC–MS/MS

A simple and selective ultra performance liquid chromatography--electrospray ionization tandem mass spectrometry （UPLC-ESI-MS/MS） assay was developed for the determination of the human plasma protein binding of four bioactive ftavonoids （such as orientin and vitexin） in Polygonum orientale. Protein precipitation was used for sample preparation. Equilibrium dialysis technique was applied to determine the plasma protein binding under physiological conditions. The separation was achieved through a Waters C i s column with a mobile phase composed of 0.1% formic acid in acetonitrile and 0.1% aqueous formic acid using step gradient elution at a flow rate of 0.35 mL/min. A Waters ACQUITYTM TQD system was operated under the multiple reaction monitoring （MRM） mode of positive electrospray ionization. All of the recovery, precision, accuracy and stability of the method met the requirements. Good correlations （r 〉 0.99） of the four compounds were found, which suggested that these compounds can be simultaneously determined with acceptable accuracy. Results showed that the plasma protein bindings of the four bioactive flavonoids were in the range of 74-89% over the six concentrations studied. The binding parameters containing protein binding affinity, protein binding dissociation constant, and protein binding site were studied. The maximum ability to bind with protein was also determined in the assay in order to understand the drug-protein binding of each compound better.

Comparative proteomic analysis of plasma proteins in patients with age-related macular degeneration

AIM:To find the significant altered proteins in agerelated macular degeneration(AMD)patients as potential biomarkers of AMD.METHODS:A comparative analysis of the protein pattern of AMD patients versus healthy controls was performed by means of proteomic analysis using twodimensional gel electrophoresis followed by protein identification with MALDI TOF/TOF mass spectrometry.RESULTS:We identified 28 proteins that were significantly altered with clinical relevance in AMD patients.These proteins were involved in a wide range of biological functions including immune responses,growth cytokines,cell fate determination,wound healing,metabolism,and anti-oxidance.CONCLUSION:These results demonstrate the capacity of proteomic analysis of AMD patient plasma.In addition to the utility of this approach for biomarker discovery,identification of alterations in endogenous proteins in the plasma of AMD patient could improve our understanding of the disease pathogenesis.

Study on the correlation and predictive value of serum pregnancyassociated plasma protein A, triglyceride and serum 25-hydroxyvitamin D levels with gestational diabetes mellitus

BACKGROUND Gestational diabetes mellitus(GDM)is a concern due to its rapid increase in incidence in recent years.AIM To investigate the correlation and predictive value of serum pregnancyassociated plasma protein A(PAPP-A),triglyceride(TG),and 25-hydroxyvitamin D[25-(OH)D]with GDM in early pregnancy.METHODS A total of 99 patients in early pregnancy admitted to Peking University International Hospital from November 2015 to September 2017 were included,and underwent a fasting glucose test and oral glucose tolerance test screening at 24-28 wk of pregnancy.Of these cases with GDM,51 were assigned to group A and the remaining 48 cases without GDM were enrolled in group B.Serum PAPP-A,TG and 25-(OH)D in the two groups were compared and their correlation with blood sugar was analyzed.In addition,their diagnostic value in GDM was determined using receiver operating characteristic(ROC)curve analysis.RESULTS Group A had markedly lower serum PAPP-A and 25-(OH)D levels and a significantly higher serum TG level than group B,with statistical significance(P<0.05).Furthermore,Pearson analysis identified that PAPP-A and 25-(OH)D levels were negatively correlated with fasting blood glucose(FBG)levels(r=-0.605,P<0.001),(r=-0.597,P<0.001),while TG and FBG levels were positively correlated(r=0.628,P<0.001).The sensitivity,specificity,area under the curve(AUC)and optimal cut-off value of serum PAPP-A level in the diagnosis of GDM were 72.55%,82.35%,0.861 and 16.340,respectively,while the sensitivity of TG in diagnosing GDM was 86.27%,the specificity was 66.67%,the AUC was 0.813,with an optimal cut-off value of 1.796.The corresponding sensitivity,specificity,AUC and optimal cut-off value of serum 25-(OH)D were 64.71%,70.59%,0.721 and 23.140,respectively.Moreover,multivariate logistic regression analysis revealed that FBG,vascular endothelial growth factor,Flt-1,serum PAPP-A,TG,and 25-(OH)D were related risk factors leading to GDM in patients.CONCLUSION Serum PAPP-A,TG,and 25-(OH)D levels are all correlated with blood glucose changes in GDM,and are independent factors affecting the occurrence of GDM and have certain value in the diagnosis of GDM.

Genetic relationship between serum pregnancy-associated plasma protein-A gene polymorphism and ischemic cerebrovascular disease in a Northern Han Chinese population

The present study recruited 193 patients with ischemic cerebrovascular disease from Inpatient and Outpatient Departments at the Affiliated Hospital of Qingdao University Medical College, China from August 2008 to May 2010, as well as 120 healthy volunteers from the Medical Examination Center at the Affiliated Hospital of Qingdao University Medical College, China, who served as controls for this study. Patients and control subjects were from the Han population in northern China. Enzyme- linked immunosorbent assay analysis revealed increased levels of serum pregnancy-associated plasma protein-A （PAPP-A） in ischemic cerebrovascular disease patients compared with healthy controls. In addition, the patients exhibited greater frequency of genotype CC and C alleles in a missense A/C （Tyr/Ser） polymorphism （dbSNP： rs7020782） of exon 14 in the PAPP-A gene. Multiple-factor logistic regression analysis on correction of age, gender, history of smoking, hypertension, diabetes mellitus, hypercholesteremia, and ischemic stroke family history showed that the risk for ischemic cerebrovascular disease in the population without the A allele at the A/C genetic locus in exon 14 of the PAPP-A was 2-folds greater than the population expressing the A allele. These experimental findings suggested that ischemic cerebrovascular disease correlated with the C allele in exon 14 of PAPP-A. In addition, the A allele is likely a protective gene; individuals carrying the A allele were less prone to ischemic cerebrovascular disease compared with individuals without the A allele.

Human plasma protein binding of water soluble flavonoids extracted from citrus peels

The human plasma protein binding of water soluble flavonoids in the peels of five spices of citrus fruits was studied by ultrafiltration combined with HPLC.The flavonoids were extracted separately by hot and cold water,and higher total flavonoid contents were detected in the former extracts than the latter ones.All the extracts show significant scavenging abilities to both ABTS and DPPH free radicals,which indicates the health benefits of the water extracts of citrus fruits peels.For DPPH radical,the IC50values of hot extract follow as Navel orange(NO)≈Mandarin orange(MO)< Lemon(LE)< Lo tangerine(LO)< Pomelo(PO),while the rank is NO< PO<LE≈MO<LO for ABTS radical.The HPLC results reveal that the kinds and contents of the flavonoids detected in the extracts are different among the species.MO extract has the most neohesperidin dihydrochalcone of 118.76 μmol/L and quercetrin of 211.81 μmol/L of which are much more than the rest extracts.Pomelo extract has the most plentiful flavonoids of naringin with a concentration of 303.28 μmol/L.The high contents of myricetrin and dihydromyricetin which both are potent free radical scavengers may explain the highest free radical scavenging activity of the NO extract.The plasma binding rates decrease with the increasing concentrations of flavonoids,and the flavonoids having plenty hydroxyl groups on both A ring and B ring of the molecular skeleton have relative higher plasma binding rates.In addition,the plasma binding rates of flavonoids with saturated C3-C4 bond decrease significantly with the increasing concentrations.

Plasma protein oxidation and total antioxidant power in premenstrual syndrome

Objective:To explore whether oxidative stress has any role in premenstrual syndrome(PMS). Methods:Female volunteers suffering from PMS,in the age group of 20-24 years were compared to their asymptomatic normomennorhoeic counterparts in follicular phase and late luteal phase for ferric reducing antioxidant power of plasma(FRAP),plasma protein thiols(PPT) and protein carbonyls(PPC) levels.Results:There was no significant change in FRAP and PPC levels in controls and PMS groups but PPT decreased significantly in luteal phase of PMS(P【 0.05) when compared to follicular phase.Conclusions:Estrogen and progesterone,might be responsible for a healthy antioxidant profile in PMS.However,a marked decrease in PPT in luteal phase of PMS group may be due to pro-oxidant nature of estrogen-active in this phase of PMS leading to consumption of the sacrificial antioxidant-protein thiol.

Characteristics,formation mechanism and stability of high internal phase emulsions stabilized by porcine plasma protein (PPP) / carrageenan (CG) hybrid particles

High internal phase emulsions (HIPEs) stabilized by nanoparticles based on biomacromolecules are challenging issues in recent decade.Herein,a newly developed HIPE was investigated by using heat-denatured porcine plasma protein (PPP) nanoparticles at pH 6.5 as emulsifier,and its emulsifying stability could be significantly enhanced by compounding carrageenan (CG).In the miscible system,PPP and CG formed hybrid particles through non-covalent interaction,and the sizes and zeta-potentials of the particles increased significantly along with addition of CG (from 0 to 0.7%,w/v),reached up to about 3.6 μm and −53 mV at 0.5% (w/v),respectively.CG weakened the ability of PPP to lower interfacial tension of oil/water (O/W),but increased the apparent viscosity of the system.The results from CLSM,rheology and stability experiments indicated a significant increasing trend of the HIPEs stability and solid-like characteristics along with addition of CG.Compared with the controls including bovine serum albumin (BSA),BSA-CG and CG alone,PPP-CG hybrid particles had good performance in fabricating and stabilizing the HIPEs.The work revealed the novel function of PPP as emulsifier of HIPEs and so offered the theoretical direction for application of PPP as a mass by-product,as well as an excellent HIPEs system for food,medicine and cosmetics fields.

Application of a UPLC–MS/MS method to the protein binding study of TM-2 in rat, human and beagle dog plasma

TM-2 known as a potential antitumor drug is a novel semi-synthetic taxane derivative. As drug-protein interactions contribute to insights into pharmacokinetic and pharmacodynamic properties, we eluci- dated the binding of TM-2 to plasma protein. In this study, a simple, rapid and reliable method was developed and validated employing equilibrium dialysis for the separation of bound and unbound drugs and ultra-performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） for the quantitation. Protein binding reached equilibrium within 24 h of incubation at 37 ℃. After liquid-liquid extraction with methyl tert-butyl ether, the samples were separated on Thermo Syncronis UPLC C18 （2.1 mm× 50 mm, 1.7 μm）, and acquisition of mass spectrometric data was performed in multiple re- action monitoring （MRM） mode via positive electrospray ionization. The assay was linear over the concentration rang of 5-2000 nglmL The intra- and inter-day precisions were 0.1%-14.8%, and the accuracy was from -6.4% to Z0%. This assay has been successfully applied to a protein binding study of TM-2 in rat, human and beagle dog plasma. TM-2 showed high protein binding of 81.4% ± 6.5% （rat）, 87.9% ± 3.6% （human） and 79.4% ± 4.0% （beagle dog）. The results revealed that there was an insignificant difference among the three species.

Changes of pregnancy-associated plasma protein-A in patients with acute coronary syndrome

The term vulnerable patient has been proposed to define subjects susceptible to an acutecoronary syndrome （ACS） or sudden cardiac death based on plaque characteristics, blood abnormalities, or myocardial vulnerability. 1 It will be important in the future to identify both vulnerable patients and vulnerable plaques. Atherosclerotic arteries obtained at autopsy from patients who died suddenly of cardiac causes indicate that pregnancyassociated plasma protein-A （ PAPP-A ） was abundantly expressed in plaque cells and in the extracellular matrix of ruptured and eroded unstable plaques, but not in stable plaques. Here we examined circulating PAPP-A levels in patients with ACS in order to evaluate its potential use in identifying vulnerable patients.

Protective,controlled-release and embedding mechanism of porcine plasma protein cold-set gel on quercetin:An effective carrier of hydrophobic compounds

Protection and embedding of hydrophobic bioactive compounds using protein hydrogels are emerging focus during the latest decade.In present study,we fabricated the porcine plasma protein(PPP)cold-set gel by microbial transglutaminase(MTGase)and glucono-δ-lactone(GDL)as coupling precursors.As a result,the embedding,protection and controlled-release effect of the gel on vulnerable hydrophobic bioactive components(quercetin(Que)as representative)with proposed molecular mechanisms were investigated in detail.The results showed that high concentration of Que(5 mmol/L)could be loaded with PPP cold-set gel and embedding efficiency(EE)was over 98%.Compared with free Que,the embedded one exhibited significantly higher thermostability,photochemical stability and storage stability(P<0.05).In addition,the gel loaded with 5 mmol L^(−1) of Que had higher swelling potency under gastric(low pH)media and controlled release performance following simulated intestinal digestive pathway.Water holding capacity(WHC)implied that free water molecules played less role in the retention ability of Que in fabricated gel network.Spectral-assisted structural characterization proved that Que was efficiently embedded mainly by generating PPP-Que complex through hydrogen bond and van der Waals force,and the binding site was mainly near Trp residue.This work gave novel insight into the potential use of PPP cold-set gel as an excellent carrier towards protection and selective delivery of vulnerable small hydrophobic nutraceutical compounds.

Proso Millet Protein Elevates Plasma Level of High-Density Lipoprotein:A New Food Function of Proso Millet

We examined the effects of dietary proso-millet protein on plasma levels of high-density lipoprotein (HDL) cholesterol in different rats from animals reported in our previous studies. The results showed also, in this animal, that the ingestion of the millet protein elevates plasma levels of HDL-cholesterol like our earlier works. Taking into account the anti-atherogenic function of HDL, therefore, the millet protein would be useful as a new food ingredient which has the function that regulates cholesterol metabolism

Generation and Identification of Monoclonal Antibody Against Porcine Adipocyte Plasma Membrane Proteins

Production of monoclonal antibody against porcine adipocyte plasma membrane proteins to explore a new way of controlling body fat deposition and improving carcass quality is discussed in this article. Membrane proteins of pig adipocyte plasma membrane proteins were extracted with the help of sucrose density gradient centrifugation, and two kinds of proteins were obtained. The monoclonal antibody （designated 3B2 and 3F3） of IgG1 and IgG2b subclass against adipocyte membrane proteins were produced by immunization, with adipocyte membrane proteins as an antigen, and its titer was 1：105 detected by enzyme-linked immunoadsorbent assay （ELISA）. The cell strains were identified by analyzing the number of chromosomes, the heat stability, the acid and alkali, the types and subtypes of immnoglobulin, and its peculiarities and affinities. Through identification, the chromosome number of hybridoma cell strains was from 80 to 100 and the strains formed good hybridomas colonies. The strains＇ affinity constants were 4.63 × 10^9 and 3.75 × 10^9 （mol L^-1）-1, respectively. At the same time, the McAb secreted was stable to environmental factors, such as, temperature, acid, alkali and so on. The monoclonal antibodies had been obtained and their specificity to porcine adipocyte plasma membrane proteins had been identified.

Water relations and an expression analysis of plasma membrane intrinsic proteins in sensitive and tolerant rice during chilling and recovery

寒心的损害的症状是在射击的水赤字的开发，源于水运输和蒸发的不平衡。在这个工作，二个米饭变化(Oryza sativa L。var。Wasetoitsu 和 Somewake ) 幼苗是在 7 度 C 的 chilled，在 28 度 C 由恢复列在后面。基于生长显型和电解质漏测试， Somewake 被显示是一个寒心容忍的变化，和 Wasetoitsu 寒心敏感的。寒心的压力显著地减少了叶子，积聚的蒸发和渗透的根的相对的水内容(RWC ) 在两个变化的水力的电导率(Lp ) 。但是当回到了 28 度 C 时， Somewake 的水关系平衡更好恢复了。所有 11 血浆膜的 mRNA 表示侧面内在的蛋白质(果仁) ， aquaporins 的亚群，被有 TaqMan 次要的林子文件夹(MGB ) 的 -PCR 探查的即时反向的抄写(RT ) 随后决定源于米饭 var。Nipponbare 在寒心的处理和恢复期间。大多数 PIP 基因在低温度是下面调整的，并且在温暖的温度恢复了。在 Somewake 和 Wasetoitsu 的一些果仁的相对表示在平行减少了在期间寒心。然而在恢复期间， OsPIP1 的相对表示； 1， OsPIP2； 1， OsPIP2； 7 在射击和 OsPIP1； 1， OsPIP2； 1 比 Wasetoitsu 在 Somewake 在根是显著地更高的。这在在寒心的条件以后重建水平衡支持果仁的角色。我们讨论 aquaporin 果仁亚科的成员在植物起的多样化的作用寒心的忍耐取决于 aquaporin isoforms，植物织物和寒心的持续时间的阶段。

Plasma graft of poly(ethylene glycol) methyl ether methacrylate (PEGMA) on RGP lens surface for reducing protein adsorption

Poly（ethylene glycol） methyl ether methacrylate（PEGMA） was grafted on fluorosilicone acrylate rigid gas permissible contact lens surface by means of argon plasma induced polymerization to improve surface hydrophilicity and reduce protein adsorption.The surface properties were characterized by contact angle measurement,x-ray photoelectron spectroscopy（XPS） and atomic force microscopy respectively.The surface protein adsorption was evaluated by lysozyme solution immersion and XPS analysis.The results indicated that a thin layer of PEGMA was successfully grafted.The surface hydrophilicity was bettered and surface free energy increased.The lysozyme adsorption on the lens surface was reduced greatly.

Plasma and wound fluid levels of eight proangiogenic proteins are elevated after colorectal resection

BACKGROUND Colorectal resection is associated with 3-5 wk long elevations in the plasma levels of at least 11 proangiogenic proteins that may stimulate tumor angiogenesis postsurgery.The increases during the first week after surgery may be related to the acute inflammatory response;the cause(s)of the week 2-5 increases is unknown.The wounds are a possible source because of the important role that angiogenesis plays in the healing process.The main hypothesis of the study is that wound fluid levels of the proteins studied will be elevated well beyond plasma levels which,in turn,are elevated from preoperative baseline levels.AIM To determine plasma and wound fluid levels of 8 proangiogenic proteins after colorectal resection for cancer and benign pathology.METHODS Blood and wound fluid samples were taken simultaneously on postoperative(postop)day 1,3,and later time points until wound drain removal in 35 colorectal cancer patients and 31 benign disease patients undergoing colorectal resection in whom closed wound drains had been placed in either the pelvis or the subcutaneous space of the abdominal incision.Postop plasma levels were compared to preop plasma and postop wound fluid levels(separate analyses for cancer and benign groups).RESULTS Sixty-six colorectal disease patients were studied(35 cancer,31 benign pathology).Most patients underwent minimally invasive surgery(open surgery in 11%of cancer and 6%of benign patients).The majority in the cancer group had rectal resections while in the benign group sigmoid or right colectomy predominated.Plasma levels of all 8 proteins were significantly elevated from baseline (P<0.05) at all post-operative time points in the cancer group and at 90% of time points(29/32) in the benign group.Wound levels of all 8 proteins were 3-106 times higher (P<0.05) than plasma levels at 87-90 percent of postop time points;of note,wound levels were more than 10 times higher at 47-50% of time points.CONCLUSION Plasma protein levels were elevated for 3 weeks after surgery;wound fluid levels were much greater than corresponding blood levels.Healing wounds may be the source of the plasma increases.

Comparison of protein concentrations in serum versus plasma from Alzheimer’s patients

Background: There is great interest in developing blood-based biomarkers for Alzheimer’s disease (AD);however, there is no consensus as to what blood fraction is most appropriate for analyzing particular markers. The current study provides empirical evidence regarding how blood-based proteins vary depending on whether they are assayed in serum or plasma. Methods: Weanalyzed concentrations of 100 proteins in matched samples of serum and plasma from 39 Caucasian AD participants from the Texas Alzheimer’s Research and Care Consortium bymultiplex immunoassay. Results: Concentrations of 40 proteins were highly correlated (r2≥ 0.75) between plasma and serum while the remaining proteins were moderately to weakly correlated (r2< 0.75). Discussion: Whether plasma vs. serum is assayed can have a large impact on the observed concentration of some proteins, including several proteins that are of great interest to AD pathophysiology. The current findings may explain the significant discrepancies often times reported in the AD biomarker field.

Heparin-binding proteins from boar seminal plasma affecting the release of prostaglandins and interleukin-6 by porcine endometrial and cervical cells and bovine endometrial cells

The objectives of this study were to explore whether heparin-binding proteins, separated by fast protein liquid chromatography from boar seminal plasma influence the release of prostaglandins F2α, (PGF2α), E2 (PGE2) and interleukin-6 (IL-6) by porcine endometrial and cervical cells and even bovine endometrial cells. In Experiment I, we showed that release of PGF2α by endometrial epithelial, endometrial stromal and cervical stromal cells to the medium was inhibited (p α (TNFα) stimulated release of IL-6 by endometrial and cervical stromal cells after 24 h incubation, but in the presence of heparin-binding proteins, this stimulation was attenuated. Release of PGF2α by cryopreserved (Experiment II) and primary (Experiment III) cervical stromal cells was significantly inhibited after 3 h incubation with 66 - 95.4 μg of heparin- binding proteins. A significant inhibition of PGE2 release by cryopreserved and primary cervical stromal cells was already achieved after incubation with 16.5 - 23.9 μg of heparin-binding proteins. The release of IL-6 by cryopreserved cells was stimulated after 3 h incubation with heparin- binding proteins in a dose dependent manner in contrast to the release of IL-6 by freshly isolated cervical stromal cells. We also found (Experiment IV) that porcine heparin-binding seminal plasma proteins inhibited release of PGF2α and stimulated release of IL-6 by bovine endometrial epithelial cells. In conclusion, a group of heparin-binding proteins separated by fast protein liquid chromatography from boar seminal plasma inhibit PGF2α, PGE2 and stimulate IL-6 release by porcine endometrial and cervical cells and even by bovine endometrial cells. Thus, these proteins have a similar effect as the entire seminal plasma.

Secondary Structure Changes and Thermal Stability of Plasma Membrane Proteins of Wheat Roots in Heat Stress

The wheat roots membrane separates the cell from the environment around it and encloses the cell contents. The pro-tein secondary structure and thermal stability of the plasma membrane of wheat root have been characterized in D2O buffer from 20°C to 90°C by Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Quantitative analysis of the amide I band (1700 - 1600 cm–1) showed that the plasma membrane proteins contains 41% α-helix, 16% β-sheet, 18% turn, and 25% disorder structures at 20°C. At elevated temperatures from 25°C up to 90°C, the α-helix and the β-sheet structure unfold into turns and the disorder structure, with a major conformational transition occurring at 50°C. There is a rapid decline in H+-ATPase activity of plasma membrane from 35°C to 55°C and it remain very low level H+-ATPase activity of PM from 55°C to 90°C. Therefore the protein conformational transition was one of reasons of loses H+-ATPase activity of plasma membrane.

Comparison of the level of thrombus precursor protein in blood plasma between patients with acute cerebral infarction and healthy persons at different time

BACKGROUND： Thrombus precursor protein （TpP） is the index of thrombus activity level, and it is also early referencing index in detecting thrombus diseases. OBJECTIVE： To dynamically observe the changes of TpP level in blood plasma of patients with acute cerebral infarction at different time after onset, and to compare the differences of plasma TpP level between patients with acute cerebral infarction and healthy persons who received health examination. DESIGN： Controlled observation SETTING： Department of Neurology, Affiliated Hospital of Xuzhou Medical College PARTICIPANTS： Totally 58 patients with acute cerebral infarction who received the treatment in the Department of Neurology, Affiliated Hospital of Xuzhou Medical College between September 2004 and March 2005 were recruited in this study. They all met the diagnostic criteria revised by the 4^th National Conference of Cerebrovascular Disorders in 1995 and were diagnosed by clinical and skull CT and （or） MRI examinations. The patients included 33 male and 25 female aged from 36 to 87 years. Time to onset 〈 6 hours, 6 to 11 hours, 12 to 23 hours, 24 to 48 hours and 〉 48 hours were found in 10,11,14,10 and 13 patients respectively. Another 51 persons who homeochronously received the health body examination in our hospital were recruited, including 34 male and 17 female, aged 38 to 85 years, serving as control group. Patients with cardio-cerebrovascualr diseases or liver and kidney diseases were excluded. All the involved subjects were informed of the detected items. METHODS： About 4 mL venous blood was respectively taken from patients admitted to the hospital within 6 hours, 6 toll hours, 12 to 23 hours, 24 to 48 hours and more then 48 hours after onset, and healthy persons when receiving health examination. The level of TpP in blood plasma was measured with enzymelinked immunosorbent assay. MAIN OUTCOME MEASURES： ① Comparison of the level of plasma TpP between patients and controls;② Comparison of the level of plasma TpP of patients with acute cerebral infarction at different time after onset. RESULTS： Totally 58 patients with acute cerebral infarction and 51 persons who received health examination participated in the result analysis. ①Comparison of plasma TpP level between patients and controls： The plasma TpP level of patients with acute cerebral infarction was significantly higher than that of control group [（16.12±3.28）vs （5.38±1.36） mg/L, t= 20.993, P〈 0.01 ]. ② Comparison of plasma TpP level of patients with acute cerebral infarction at different time after onset： The level of plasma TpP was （12.06±3.06） mg/L within 6 hours, （15.11±3.42） mg/L at 6 to 11 hours, （20.63±4.05） mg/L at 12 to 23 hours, （16.15±3.50） mg/L at 24 to 48 hours and （11.88±3.11） mg/L at more than 48 hours after onset. It increased from the 6^th hour, reached the peak at the 12^th to 23^rd hours, maintained at very high level at the 48= hour and then gradually decreased and recovered to the level within 6 hours after onset. The level of plasma TpP of patients with acute cerebral infarction was signiticantly higher at the 12^th to 23^rd hours after onset and the 24^th to 48^th hours after onset than within 6 hours after onset （t = 13.385, P 〈 0.05）. CONCLUSION： ①The level of plasma TpP of patients with acute cerebral infarction is significantly higher than that of persons who received health examination.② Plasma TpP levels of patients with acute cerebral infarction change in wave manner at the different time after onset.

Effects of dietary protein/energy ratio on growth performance,carcass trait,meat quality,and plasma metabolites in pigs of different genotypes

Background： The protein/energy ratio is important for the production performance and utilization of available feed resources by animals. Increased protein consumption by mammals leads to elevated feed costs and increased nitrogen release into the environment. This study aimed to evaluate the effects of dietary protein/energy ratio on the growth performance, carcass traits, meat quality, and plasma metabolites of pigs of different genotypes. Methods： Bama mini-pigs and Landrace pigs were randomly assigned to two dietary treatment groups （Chinese conventional diet with low protein/energy ratio or National Research Council diet with high protein/energy ratio; n = 24 per treatment） in a 2 x 2 factorial arrangement. Blood and muscle samples were collected at the end of the nursery, growing, and finishing phases. Results： We observed significant interactions （P 〈 0.05） between breed and diet for total fat percentage, intramuscular fat （IMF） content, protein content in biceps femoris （BF） muscle, and plasma urea nitrogen （UN） concentration in the nursery phase; for average daily gain （ADG）, average daily feed intake （ADFI）, dry matter, IMF content in psoas major （PM） muscle, and plasma total protein and albumin concentrations in the growing phase; and for drip loss and plasma UN concentration in the finishing phase. Breed influenced （P 〈 0.05） growth performance, carcass traits, and meat quality, but not plasma metabolites. Throughout the trial, Landrace pigs showed significantly higher （P 〈 0.0_5） ADG, ADFI, dressing percentage, lean mass rate, and loin-eye area than did Bama mini-pigs, but significantly lower （P 〈 0.0.5） feed/gain ratio, fat percentage, backfat thickness, and IMF content. Dietary protein/energy ratio influenced the pH value, chemical composition of BF and PM muscles, and plasma activities of glutamic-pyruvic transaminase and gamma-glutamyl transpeptidase, and plasma concentration of UN. Conclusions： Compared with Landrace pigs, Bama mini-pigs showed slower growth and lower carcass performance, but had better meat quality. Moreover, unlike Landrace pigs, the dietary protein/energy ratio did not affect the growth performance of Bama mini-pigs. These results suggest that, in swine production, low dietary protein/energy ratio may be useful for reducing feed costs and minimizing the adverse effects of ammonia release into the environment.