Abstract：
BACKGROUND:Formation of deposits of the insoluble amyloid beta-peptide is believed to be causally related with neurodegeneration in Alzheimer disease (AD). The beta-peptide originates from a larger amyloid precursor protein (APP) by the action of proteolytic enzymes. The first proteolytic event leading to amyloid formation is the cleavage of APP by the membrane-bound aspartyl protease BACE-1, also known as memapsin-2. Inhibition of BACE-1 is thought to be a therapeutic approach to AD. Measuring BACE-1 activity in biological samples would be useful to elucidate the mechanism of AD and for development of AD drugs. METHODS:We developed a sensitive and specific activity assay for BACE-1. The assay is based on a genetically engineered proenzyme that is specifically activated by BACE-1. The resulting active enzyme is measured with a chromogenic substrate. The use of 2 coupled reactions produces a detection limit as low as 0.4 pmol/L. RESULTS:The assay detected BACE-1 activity in extracts of human brain tissue as well as, unexpectedly, in human cerebrospinal fluid (CSF). Gel electrophoresis and Western blotting identified the BACE-1 present in CSF as a truncated soluble form of the originally membrane-bound BACE-1. CONCLUSION:Detection of the soluble form of BACE-1 in CSF, a relatively easily accessible biological fluid, may be useful for monitoring the effects of drug candidates in vivo and may have diagnostic or prognostic applications.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Verheijen JH,Huisman LG,van Lent N,Neumann U,Paganetti P,Hack CE,Bouwman F,Lindeman J,Bollen EL,Hanemaaijer Rdoi
10.1373/clinchem.2006.066720subject
Has Abstractpub_date
2006-06-01 00:00:00pages
1168-74issue
6eissn
0009-9147issn
1530-8561pii
clinchem.2006.066720journal_volume
52pub_type
杂志文章abstract：:We report a procedure for determining fecal long-chain fatty acids (LCFA), triglycerides, and cholesterol after detergent extraction with 10 mL/L Triton X-100, 6 mL/L Brij 30, and 0.1 mol/L HCl in isotonic saline by enzymatic analysis of the extraction supernates. Mean recoveries of calibrators ranged from 105% to 117...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-12-01 00:00:00
abstract：:To correct the results of a radioimmunoassay for beta-thyrotropin (TSH) subunit by eliminating the proportion ascribable to intact TSH, we have devised a method that experimentally reproduces the conditions under which the interference develops. Beta-TSH subunit was assayed in several preparations containing known con...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-05-01 00:00:00
abstract：:We describe a simple method for evaluating thyroxine-binding globulin capacity and concentration from a single 1-cm blood spot on filter-paper used in a screening program for neonatal hypothyroidism. This method permits prompt diagnosis of about 90% of the infants with thyroxine-binding globulin deficiency in our abno...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-03-01 00:00:00
abstract：:We describe a rapid and simple insulin RIA in which proinsulin and conversion intermediates do not interfere. Three monoclonal antibodies (S1, S2, and S53) were selected for their specificity (directed, respectively, against the B10 region, the junction between A chain and C-peptide, and the junction between B chain a...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-07-01 00:00:00
abstract：:We evaluated the Kallestad "Quanticoat" cortisol RIA for direct (no extraction) measurement of urinary free cortisol, which requires no solvent extraction. An analytical-recovery study showed a linear regression of y (measured) = 0.65x (added) + 37.5 micrograms/L (Sy.x = 21.4 micrograms/L, r = 0.978, n = 48). Recovery...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-01-01 00:00:00
abstract：:Liquid scintillation counting of 3H-labeled whole-blood samples is severely impaired owing to quenching by blood pigments. In this study, dry oxidation and chemical solubilization followed by decolorization were the two general methods used to eliminate color quenching. Three blood volumes were examined: 0.25, 0.50, a...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-04-01 00:00:00
abstract：:We evaluated superoxide dismutase (EC 1.15.1.1) and glutathione peroxidase (EC 1.11.1.9) activities in the erythrocytes of lead-exposed and nonexposed workers from distinct industries localized in the State of São Paulo, Brazil. Concentrations of either lead or protoporphyrin IX, or both, in blood were used to indicat...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-10-01 00:00:00
abstract：:We used a modification of the polymerase chain reaction (PCR), involving two pairs of oligonucleotide primers, to detect a mutation in the low-density lipoprotein (LDL) receptor gene, commonly occurring among patients with familial hypercholesterolemia (FH) in Finland. This mutation, called FH-Helsinki, involves a lar...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-06-01 00:00:00
abstract：:gamma-Aminobutyric acid (GABA), an inhibitory neurotransmitter that serves about one-third of brain neurons, is involved in the development of depression and in the treatment of depression and mania with pharmacological therapy. Brain activity of GABA may be conveniently measured in plasma, and changes in plasma conce...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1994-02-01 00:00:00
abstract：BACKGROUND:The alteration of the bone microenvironment as a consequence of skeletal metastases is poorly understood. The aim of this study was to search for patterns of bone markers in relation to primary tumor type, bone pain, and number of sites involved in patients with bone metastases. METHODS:We studied 323 patie...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：
更新日期：1999-08-01 00:00:00
abstract：:We detected the presence of creatine kinase (EC 2.7.3.2) MB isoenzyme (CK-MB) in serum by using an immunoinhibition technique to inactivate the creatine kinase isoenzyme of muscle origin (CK-MM). The GEMSAEC centrifugal analyzer is ideally suited for this procedure because it rapidly mixes reagents and has a throughpu...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-04-01 00:00:00
abstract：:We developed a new colorimetric method, DNA enzyme immunoassay (DEIA), for detecting specific hybrids of complementary nucleic acids and applied it to the detection of hepatitis B virus (HBV) DNA amplified from serum samples by means of the polymerase chain reaction (PCR) technique. The method is based on the ability ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1991-03-01 00:00:00
abstract：:Zinc protoporphyrin is the predominent fluorescent porphyrin accumulating in erythrocytes as a result of chronic lead absorption or iron-deficiency anemia. Although diagnostic concentrations or thresholds for it in erythrocytes have been inferred, normal adult averages have not been established. We quantitatively asse...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-09-01 00:00:00
abstract：:A study was undertaken to assess the short-term (intrapregnancy) and long-term (interpregnancy) variability of the 1-h 50-g oral glucose challenge test (GCT). Two groups of pregnant women had GCTs in consecutive pregnancies, 1 (n = 77) and 2 (n = 43) years apart. Their results were compared with published results for ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-02-01 00:00:00
abstract：:We describe a gas-chromatographic method for measuring chlorpromazine and its metabolites chlorpromazine sulfoxide, mono-N-desmethylchlorpromazine, and di-N-desmethylchlorpromazine at therapeutic concentrations in human serum, with use of a nitrogen detector. The compounds are extracted from serum at pH 10.5 into hexa...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-07-01 00:00:00
abstract：:Agarose column chromatography has been used to separate plasma lipoproteins into very-low-density lipoproteins (VLDL), low-density lipoproteins (LDL) and high-density lipoproteins (HDL). Applied to the diagnosis of primary type III hyperlipoproteinemia, the procedure is capable of demonstrating three characteristic an...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-12-01 00:00:00
abstract：:We report an easy, rapid method for quantifying bone isoenzyme of alkaline phosphatase (EC 3.1.3.1., ALP) in serum. The original method described by Rosalki and Ying Foo (Clin Chem 1984;30:1182-6) was somewhat simplified. In contrast to their results, we found that bone ALP is precipitated quantitatively by wheat-germ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-10-01 00:00:00
abstract：:Currently, we can make the following generalizations about the major long-term complications of diabetes. First, they occur commonly after 10 to 15 years of diabetes. Second, the complications of renal and retinal disease, but not of atherogenic and neurological disease, appear to be related to the severity of hypergl...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章,评审
doi：
更新日期：1986-10-01 00:00:00
abstract：:Use of an 125I radioimmunoassay involving antiserum coupled to magnetizable cellulose, after prednisolone-21-phosphate interference is removed by dichloromethane extraction at pH 7.4 and endogenous glucocorticoid interference is removed by selective chemical derivatization with Girard's Reagent T [(carboxymethyl)trime...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-07-01 00:00:00
abstract：:We describe microplate methods for measurement of human urinary albumin (HUA) by competitive enzyme-linked immunosorbant assay (ELISA) and creatinine with a modified commercial enzymatic kit. Incorporation of substrate mixing into the competitive ELISA changes the dynamic absorbance-concentration response, greatly sim...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-07-01 00:00:00
abstract：BACKGROUND:Increased concentrations of cell-free DNA have been found in several disorders and have been interpreted as evidence of increased rates of cell death or turnover. Evidence from in vitro and animal experiments suggests that DNA may play a role in the pathogenesis of rheumatoid arthritis (RA). METHODS:We meas...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.084509
更新日期：2007-09-01 00:00:00
abstract：:Nitric oxide is too short-lived to measure in vivo, but its production can be estimated by measuring its stable oxidation products, nitrites and nitrates, in serum. Renal elimination of these ions has been demonstrated, but the effect of renal function on their concentrations in serum is currently unknown. We evaluate...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-03-01 00:00:00
abstract：:The diagnosis of thyroid disease now often can be achieved reliably by measuring thyrotropin (TSH) alone. Thyroxine (T4), triiodothyronine, and other analytes are only needed if TSH and the accompanying clinical condition are discordant. We describe here work that confirms the age independence of TSH in both inpatient...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-11-01 00:00:00
abstract：:Extensive data implicate cholesterol in the atherosclerotic process responsible for coronary disease. Of the atherosclerotic disease outcomes, serum cholesterol is most strongly related to coronary disease. A significant relationship of serum cholesterol to all clinical manifestations of coronary heart disease has bee...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1988-01-01 00:00:00
abstract：:Purified arylsulfatase A (EC 3.1.6.1) from human urine was radioiodinated under conditions that caused no significant loss of antigenic activity. We used this labeled arylsulfatase A (specific radioactivity 4-7.5 Ci/g) together with nonlabeled enzyme and rabbit antiserum produced against homogeneous enzyme to develop ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-03-01 00:00:00
abstract：:We describe a new method for quantitatively measuring substances of clinical interest by high-performance liquid affinity chromatography (HPLAC). As a model system we selected analysis for transferrin in human serum with immobilized antibodies in a high-performance liquid chromatographic system. SelectiSpher-10 Activa...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-10-01 00:00:00
abstract：:This enzyme immunoassay detects adenosine deaminase binding protein (ABP), a glycoprotein that is shed from the brush border of the proximal tubule in kidney damage. Two monoclonal antibodies, URO-4 and URO-4a, each react with different epitopes on ABP and are used as the "sandwich" pair of antibodies. A linear standa...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-05-01 00:00:00
abstract：:A method is described for separating antibody-bound from free fractions in ligand assays by column affinity chromatography, and its application to radioimmunoassay of choriomammotropin. In the method, 70 x 10 mm (i.d.) polypropylene columns containing about 150 mg of immunosorbent (goat anti-rabbit gamma-globulins cov...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-06-01 00:00:00
abstract：:Histograms of the results of quantitative clinical laboratory analyses are usually broadly skewed because some of the patients have normal values with respect to the analyte being measured while values for others are below or above normal. We describe a technique for calculating the maximum possible number of individu...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-04-01 00:00:00
abstract：BACKGROUND:Buprenorphine is under investigation as a pharmacotherapeutic agent for treating opioid dependence in pregnant women. We hypothesized that there would be a relationship between the cumulative maternal dose of buprenorphine during pregnancy and the concentration of buprenorphine and norbuprenorphine in matern...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：10.1373/clinchem.2007.091413
更新日期：2007-12-01 00:00:00
