QuantiChrom™ β-N-Acetylglucosaminidase Assay Kit
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Application
- β-N-Acetylglucosaminidase activity determination in biological samples.
Key Features
- Fast and sensitive. Linear detection range (20 µL sample): 0.2 to 50 U/L for a 30 minute reaction at 37°C.
- High-throughput. Homogeneous "mix-incubate-measure" type assay. Can be readily automated on HTS liquid handling systems for processing thousands of samples per day.
Method
- OD405nm
Samples
- Urine, serum, plasma, cell lysate, etc.
Species
- All
Size
- 100 tests
Detection Limit
- 0.2 U/L
Shelf Life
- 12 months
More Details
- β-N-Acetylglucosaminidase (NAG) is a lysosomal enzyme involved in a variety of biological processes such as the degradation of glycoproteins and glycolipids, cell proliferation, and signal transduction. NAG is found in many tissues in the body, but due to its high molecular weight, it can not be filtered through the glomerular membrane. For this reason, in the presence of tubular damage or a glomerular lesion, urinary NAG activity increases. Elevated NAG levels in urine are an early indication of renal damage, such as injury due to diabetes mellitus, inflammation, nephritic syndrome, urinary tract infection, and more. Various forms of cancer have been associated with increased levels of NAG in serum. Genetically inherited lipid storage disorders, such as Tay-Sachs and Sandhoff disease, arise from deficiencies of the enzyme. BioAssay Systems non-radioactive, colorimetric NAG assay is based on the cleavage of p-nitrophenol from a synthetic substrate. p-Nitrophenol becomes intensely colored after addition of the stop reagent. The increase in absorbance at 405 nm after addition of the stop reagent is directly proportional to the enzyme activity.
How do I store the kit?
This kit is shipped at room temperature. Upon receiving, please store the substrate at -20°C and the remainder of the kit in the refrigerator (4°C).How do I prepare cell samples for assays?
Collect cells by centrifugation at 2,000 x g for 5 min at 4°C. For adherent cells, do not harvest cells using proteolytic enzymes; rather use a rubber policeman. Homogenize (10-20 passes in a Dounce homogenizer on ice) or sonicate cells (preferably performed in an ice water bath) in an appropriate volume of cold PBS, approximately one million cells per mL. Centrifuge at 14,000 x g for 10 min at 4°C. Remove supernatant for assay. It is prudent to run a pilot test of the sample at different dilutions. Choose a dilution with the readings in the linear range of the standard curve for further assays. Most samples can be stored at -80°C if not assayed immediately.Do I need to use a standard or standard curve with each assay run?
Yes, it is highly recommended.For more detailed product information and questions, please feel free to Contact Us. Or for more general information regarding our assays, please refer to our General Questions.ebiomall.com
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1)提供基本营养物质：氨基酸、维生素、无机物、脂类物质、核酸衍生物等，是细胞生长必须的物质。
2)提供结合蛋白：结合蛋白作用是携带重要地低分子量物质，如白蛋白携带维生素、脂肪、以及激素等，转铁蛋白携带铁。结合蛋白在细胞代谢过程中起重要作用。
3)提供激素和各种生长因子：胰岛素、肾上腺皮质激素(氢化可的松、地塞米松)、类固醇激素(雌二醇、睾酮、孕酮)等。生长因子如成纤维细胞生长因子、表皮生长因子、血小板生长因子等。
4)对培养中的细胞起到某些保护作用：有一些细胞，如内皮细胞、骨髓样细胞可以释放蛋白酶，血清中含有抗蛋白酶成分，起到中和作用。这种作用是偶然发现的，现在则有目的的使用血清来终止胰蛋白酶的消化作用。因为胰蛋白酶已经被广泛用于贴壁细胞的消化传代。血清蛋白形成了血清的粘度，可以保护细胞免受机械损伤，特别是在悬浮培养搅拌时，粘度起到重要作用。血清还含有一些微量元素和离子，他们在代谢解毒中起重要作用，如SeO3,硒等
5)提供促接触和伸展因子使细胞贴壁免受机械损伤。
6)血清中有抗体，这是被称作免疫球蛋白的蛋白质，血清可以抗病毒,增强抵抗力血清属于生物制剂。
谁的答案详细、真实分就给谁...(勿灌水，否则必究之)
Nutrients.2017May10;9(5).
ClinicalSignificanceandPrognosticEffectofSerum25-hydroxyvitaminDConcentrationsinCriticalandSevereHand,FootandMouthDisease.
手足口病危重儿血清25-羟维生素D浓度的临床意义与预后影响
作者党红星，刘成军，李静，程时骄，许峰
摘要
Abstract
目的：探讨血清25羟维生素D[25（OH)D]浓度与手足口病危重症的关系及评估手足口病危重儿血清25-羟维生素D浓度的临床意义与预后影响。
OBJECTIVE:
Toexaminetheassociationofserum25-hydroxyvitaminD[25(OH)D]concentrationswithcriticalandseverehand,footandmouthdisease(HFMD)andassesstheclinicalsignificanceandprognosticeffectof25(OH)DconcentrationsinchildrenwithHFMD.
方法：本研究为前瞻性观察研究。
METHODS:
ThisisaProspectiveobservationalstudy.
将138例手足口病患儿分为普通组（49例）、重症组（52例）和危重组（37例）。另选取同期门诊体检的59例健康儿童作为对照组。
The138childrenwithHFMDweredividedintocommon(49cases),severe(52cases),andcritical(37cases)HFMDgroups.Another59healthychildrenundergoingoutpatientmedicalexaminationsduringthesameperiodwerechosenasthecontrolgroup.
测定所有对象的血清25（OH）D浓度，每组再分为血清25（OH）D正常组（≥30ng/mL）；不足组（20-29.9ng/mL）；缺乏组（低于20ng/mL）。
Serum25(OH)Dconcentrationsweremeasuredinallthesubjects,andeachgroupwassuBDividedbyserum25(OH)Dconcentrationinto25(OH)Dnormal(≥30ng/mL);insufficiency(20-29.9ng/mL),anddeficiency(<20ng/mL)groups.
手足口病危急重症组在入住儿科ICU（PICU）时记录小儿危重病例评分（PCIS）。
Thepediatriccriticalillnessscore(PCIS)wasrecordedforthecriticalandsevereHFMDgroupuponadmissiontothepediatricintensivecareunit(PICU).
监测小儿危重手足口病患者血乳酸（LAC）、血清钙离子（Ca2+）、D-二聚体（DD）、乳酸脱氢酶（LDH）、肌酸激酶同工酶（CK-MB）水平；脑干脑炎、神经源性肺水肿、循环衰竭的发生情况；14天病死率。
ChildrenwithcriticalandsevereHFMDwerealsomonitoredforbloodlactate(LAC),serumcalciumions(Ca++),D-dimer(DD),lactatedehydrogenase(LDH),andcreatinekinase-MB(CK-MB)levels;theincidencesofbrainstemencephalitis,neurogenicpulmonaryedema,andcirculatoryfailure;andthe14-daymortalityrate.
结果：
RESULTS：
各组血清25（OH）D浓度普遍较低。
Serum25(OH)Dconcentrationsweregenerallylowinallgroups.
与对照组（28.1±6.6ng/mL,8%）、普通组（29.5±8.1ng/mL,10%）和重症组（31.9±9.7ng/mL,8%）相比，危重组患者血清25（OH）D平均浓度（20.0±8.4ng/mL）明显较低，血清25（OH）D缺乏比例（18％）明显较高(P＜0.05）。
ThecriticalHFMDgroupshowedasignificantlylowerserum25(OH)Dmeanconcentration(20.0±8.4ng/mL)andahigherproportionofdeficiency(18%)comparedwiththecontrolgroup(28.1±6.6ng/mL,8%),common(29.5±8.1ng/mL,10%)andsevere(31.9±9.7ng/mL,8%)HFMDgroups(p<0.05).
在危重组中，25（OH）D缺乏组比25（OH）D正常组及不足组具有更低的PCIS值（P＜0.05）；而比后两组具有更高LAC、LDH、CK-MB和DD；具有（更高的）脑干脑炎、神经源性肺水肿、循环衰竭发生率及病死率（P＜0.05）。
InthecriticalandsevereHFMDgroups,the25(OH)DdeficiencygrouphadlowerPCISsthanthe25(OH)Dnormalandinsufficiencygroups(p<0.05);andhadhighervaluesthanthelattertwogroupsforLAC,LDH,CK-MBandDD;andtheincidencesofbrainstemencephalitis,neurogenicpulmonaryedema,circulatoryfailure,andmortality(p<0.05).
死亡组较存活组具有显著降低的血清25（OH）D浓度和PCIS（P＜0.05），具有较高的LAC、LDH、CK-MB和DD水平；较高的脑干脑炎、神经源性肺水肿、循环衰竭发病率（P＜0.05）。
Thedeathgroupshowedsignificantlylowerserum25(OH)DconcentrationsandPCISsthanthesurvivalgroup(p<0.05)andhadhigherLAC,LDH,CK-MBandDDlevelsandhigherincidencesofbrainstemencephalitis,neurogenicpulmonaryedema,andcirculatoryfailure(p<0.05).
Logistic回归分析显示，血清25（OH）D浓度是影响重症手足口病患儿病死率的独立因素。
Logisticregressionanalysisrevealedthattheserum25(OH)DconcentrationwasanindependentfactorthatinfluencedmortalityinchildrenwithcriticalandsevereHFMD.
CONCLUSIONS:
结论：
在这项研究中，我们发现，血清25（OH）D浓度在手足口病危重患儿中大幅降低，并与手足口病的严重程度相关。
Inthisstudy,wefindtheserum25(OH)DconcentrationsaresubstantiallyreducedinchildrenwithcriticalandsevereHFMDandareassociatedwiththeseverityofHFMD.
血清25（OH）D浓度对判断重症手足口病进展和预测死亡风险具有临床价值。
Theserum25(OH)DconcentrationsmayhaveclinicalvaluefordeterminingtheprogressionofcriticalHFMDandpredictingtheriskofdeath.
在确定25（OH）D浓度在手足口病诊断的临床价值之前，仍需进一步的证据。
Furtherevidenceisneededbeforeitcanbestatedthat25(OH)DconcentrationshaveclinicalvalueinHMFDdiagnosis.
关键词：
KEYWORDS:
25-hydroxyvitaminD;criticalillness;footandmouthdisease;hand
25羟维生素D；危重病；手足口病
血浆是由抗凝的血液中分离出来的液体,其中含有纤维蛋白原,若向血浆中加入Ca2+,血浆会发生再凝固,因此血浆中不含游离的Ca2+.血清是由凝固的血中分离出来的液体,其中已无纤维蛋白原,但含有游离的Ca2+,若向其中再加入Ca2+,血清也不会再凝固.此外,血浆与血清的另一个区别是：血清中少了很多的凝血因子,以及多了很多的凝血产物.
