Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:6.2.1.1 (ACS)
78,556 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Total thyroxine (TT4), tracer uptake, thyroid-stimulating hormone (TSH), and free T4 (FT4) testing was examined in the ACS 180, Abbott IMx, and Stratus II systems. TSH sensitivity studies demonstrated that the ACS and IMx are second-generation assays; the Stratus showed between first- and second-generation performance. Except for one control below the detection limit, TSH imprecision was 3-10%. TSH accuracy was adequate for all systems. TT4 imprecision was 4-7%, except for the lowest control with the Stratus (18%). TT4 method agreement showed bias of about 20% between the systems. TT4 accuracy was compromised at the low end for the Stratus II, but was satisfactory otherwise. FT4 imprecision was 20% for the Stratus, < 5% for the IMx and 6% for the ACS. Uptake assays showed imprecision of 5-10%. The laboratory diagnosis indicated by each system's FT4 and calculated FT4 Index results were compared to determine diagnostic accuracy. In routine specimens, different clinical classifications were observed for 25% of specimens with the ACS, 19% with the Stratus, and 7% with the IMx; in the altered protein group, the Stratus showed 9% discordant results, the ACS showed 3%, and the IMx 0%. Of the three systems examined here, the Abbott IMx system showed the best overall performance.
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PMID:Thyroid function testing evaluated on three immunoassay systems. 760 25

Prostate cancer represents an increasing public health burden that may be controlled by early detection interventions. Several studies using transrectal ultrasound (TRUS), prostate-specific antigen (PSA), and digital rectal examination (DRE) in men without known prostate disease have been reported. Recent studies are reviewed, and recent preliminary results of the American Cancer Society-National Prostate Cancer Detection Project (ACS-NPCDP) are presented. Results show that the rate of early prostate cancer detection can be increased by coordinated use of TRUS, PSA, and DRE. The ACS-NPCDP data indicate that the positive predictive value of recommendations to biopsy is improved when based on a combination of studies. Examination by TRUS alone is least specific and least cost-effective, whereas the combination of PSA and DRE is less costly and more specific with equal sensitivity to cancer. Additional data are needed to determine if prostate cancer death rates will be altered by early detection interventions. Physicians and patients need to be informed of the possible risks and benefits of early detection interventions.
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PMID:The status of prostate cancer early detection. 768 18

Estrogen biosynthesis is catalyzed by a microsomal enzyme, aromatase cytochrome P450 (P450arom; the product of the CYP19 gene). The human CYP19 gene comprises nine coding exons, II-X. Additionally, tissue-specific expression is determined by the use of tissue-specific promoters, which give rise to P450arom transcripts with unique 5'-noncoding sequences. In placenta, P450arom transcripts contain one of two 5'-untranslated exons, I.1 or I.2, while ovarian transcripts instead contain sequence consistent with the use of a promoter, PII, which is proximal to the start of translation. To characterize transcripts present in adipose tissue and adipose stromal cells (ASC) in culture, cDNA libraries were constructed by the RACE (rapid amplification of cDNA ends) procedure. Four P450arom transcripts with unique 5' termini were identified, leading to the characterization of two unique 5'-untranslated exons of the CYP19 gene, I.3 and I.4. Whereas I.3-specific sequence is expressed in adipose tissue as well as in ACS maintained under all culture conditions, I.4-specific sequence is apparently present only in breast adipose tissue, and ACS stimulated with glucocorticoids. On the other hand, PII-specific sequence is present only in cells stimulated with cAMP analogues and is absent from cells stimulated with glucocorticoids. We conclude that CYP19 gene expression in human adipose tissue likely utilizes two novel promoters and, furthermore, that alternative promoter usage in cultured ASC is a function of the hormonal environment in which the cells are maintained.
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PMID:Tissue-specific and hormonally controlled alternative promoters regulate aromatase cytochrome P450 gene expression in human adipose tissue. 769 33

Traumatic vertebral artery injuries are relatively rare. Until recently, insufficient neurodiagnostic technology and a lack of normative data for the population of USAF aviators prevented recommending flying waivers following such vascular injuries. We report the case of an aviator who experienced a traumatic right vertebral artery occlusion with distal embolization. Timely access to a state-of-the-art neurodiagnostic evaluation, which included time-of-flight magnetic resonance angiography (MRA), and standard contrast angiography, provided anatomic imaging at the time of injury and during the recuperative period. Sophisticated neurologic testing protocols at the Armstrong Laboratory's Aeromedical Clinical Sciences Division, Brooks Air Force Base, TX, assessed in-depth this individual's functional status. Consult Service evaluators then compared his performance data with current data in the Head Injury Study in Aviators (HISA) data base. MRA, in comparison with standard contrast angiography, demonstrated anatomic stability of his vascular and neurologic lesions. He demonstrated a functional capacity consistent with normal neurologic functioning in aviators which permitted recommending an occupational (flying) waiver. This case exemplified application of sophisticated ACS neurologic testing protocols to aeromedical evaluations and the use of MRA technology as a vascular screening tool during medical followup.
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PMID:Traumatic vertebral artery occlusion in an aviator: case report and update on diagnostic technologies. 769 57

Pretreatment of human serum with 5-sulfosalicylic acid (SSA) as used in the Abbott TDx digoxin assay produces deglycosylated congeners of digoxin (DIG) and of endogenous digoxin-like immunoreactive factor (DLIF). Using high-performance liquid chromatography analysis, we observed differences in the degree and pattern of DIG breakdown products among five patients. The aglycone digoxigenin was the major product in several samples. Smaller amounts of the bis- and mono-digitoxosides and unidentified products less polar than DIG were sometimes present. Treatment of DLIF-containing plasma with SSA produced similar patterns of DLIF-breakdown products. Incubation of normal plasma containing DIG with SSA for up to 30 min caused little change in measured DIG by TDx and radioimmunoassay (RIA) but decreased to 50% in the ACS DIG assay. These results are consistent with the near 100% cross-reactivities of deglycosylated DIG congeners in the TDx and RIA assays compared to their lower cross-reactivities in the ACS assay. We conclude that the breakdown of DIG and DLIF during treatment of serum with SSA may compromise the accuracy of TDx DIG assays and may explain discrepancies observed in other studies between digoxin immunoassays. This study underscores the importance of understanding the effects of pretreatment strategies used for analytes measured by immunoassay.
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PMID:Treatment of human serum with sulfosalicylic acid structurally alters digoxin and endogenous digoxin-like immunoreactive factor. 772 77

Separation of the ammonium sulfate precipitated protein fraction of mouse ascitic fluid, containing the specific immunoglobulin (pI 6.7-6.8; molecular weight 180000), from ammonium sulfate was investigated by means of non-traditional dialysis, based on the difference in diffusion rates of small and large molecules through porous membranes. The experiments were carried out in spiral membrane modules equipped with a Neosepta (AM-2 or ACS-SB) anion exchange membrane and a microfiltration membrane (Synpore or Sartorius). To enhance the driving force for penetration of ammonium sulfate and low-molecular-weight components from solution of ascitic protein fraction into water, a counterpressure was imposed on the side of microfiltration membrane. The flow rate, counterpressure and the pore sizes of microfiltration membranes had a significant effect on the separation process, as expected. The type of the anion exchange membrane had only a small effect. This process makes it possible to desalt the immunoglobulin fraction with high purity and yield in a few hours instead of 5 days.
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PMID:Separation of specific immunoglobulin. 1. Desalination using a membrane system. 776 50

Immunoreactive digoxin-like activity was found in the Chinese medicine, KYUSHIN tablet, taken popularly in Japan without prescription. The antibodies used in the assays of digoxin reacted with Ch'an-su, the major effective component of KYUSHIN, which contained cardiotonic steroids with a chemical structure similar to that of digoxin. One tablet of KYUSHIN had digoxin-like immunoreactivity equivalent to 1.9 micrograms. (TDx analyzer), 1.5 micrograms (Du Pont aca analyzer) and 72 micrograms digoxin (Enzymun-Test, Boehringer). These different equivalencies may be attributed to differences in cross-reactivity of the antibody used in the immunoassays. Two healthy volunteers took two KYUSHIN tablets three times a day, a typical dose, and digoxin-like immunoreactivity reached almost 0.4 microgram/l in 0.5 day. Recently, a competitive digoxin chemiluminescent immunoassay has been developed by Ciba Corning ACS 180. The assay utilizes an acridinium-ester labelled mouse monoclonal digoxin antibody as the tracer. In the extracted solution of KYUSHIN and serum after administration of two tablets, the digoxin-like immunoreactivity value on the Ciba Corning ACS 180 digoxin assay was < 0.10 microgram/l (off-range low). Therapeutic drug monitoring should be interpreted carefully in patients taking Chinese medicines, many of which contain the Ch'an-su component.
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PMID:[Digoxin concentration in blood]. 788 63

The relationship between the time course of inverted T-waves during the acute phase and infarct size and left ventricular (LV) function was studied in 46 patients (mean age: 57.3 +/- 9.7 years) with reperfused first anterior wall acute myocardial infarction (MI). All patients had coronary reflow within 6 hrs after the onset of MI and were without subsequent reocclusion for at least 14 days. The T-wave inverted progressively and rapidly with maximum depth between 26 and 60 hrs (mean time: 37.1 +/- 12.4 hrs). A significant correlation was found between the maximum T-wave depth (T-peak) in all patients and peak CPK, left ventricular ejection fraction (LVEF), regional wall motion, % abnormally contracting segment (%ACS), end-diastolic and end-systolic volume indices (EDVI,ESVI) at day 14 after the onset of MI (p < 0.05). T-wave inversion within 24 hrs after onset of MI was observed in 43 patients (93%). There were significant correlations between the depth of T-wave inversion occurring in patients 24 hrs after onset of MI (T24) and peak CPK, LVEF, regional wall motion, % ACS, EDVI, and ESVI at day 14 (p < 0.05). The sensitivity and specificity for patients with EDVI > 87.0 ml/m2 at day 14 increased by more than 20% over normal values, predicted by a T24 of 3.0 mm or less, were 94% and 93%, respectively. The sensitivity and specificity for patients with EF < 40% at day 14 predicted by a T24 of 3.0 mm or less, were 90% and 75%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Clinical significance of inverted T-waves during the acute phase of myocardial infarction in patients with myocardial reperfusion]. 789 9

Acetyl CoA synthetase (ACS; EC 6.2.1.1) was studied in the mosquito, Aedes togoi, by a novel assay which coupled the acetyl-CoA generated to p-aminosalicylic acid (ASA). The N-acetylated product was determined by an HPLC-fluorimetric procedure. High ACS activity was observed in the newly-pupated pupae of both sexes and in the adult male mosquito whose activity was five times that of the female. Acetyl CoA-dependent N-acetyltransferase (NAT; EC 2.3.1.5) activity toward serotonin (5HT) was also studied using HPLC-electrochemical detection (HPLC-ECD). A progressive increase in the 5HT-NAT activity was observed from the fourth-instar larvae to the adult mosquito with the latter showing 6-fold higher activity in the head compared to the abdomen-thorax region. Kinetic studies on the pupal enzyme extracts showed that the apparent Km values for 5HT and acetyl CoA were 63 and 66 microM respectively. Tryptamine inhibited 5HT-NAT non-competitively with a Ki value of 8 microM.
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PMID:Acetyl CoA generation and N-acetylation of serotonin (5HT) in the mosquito, Aedes togoi. 791 72

Our objective was to identify commercially available digoxin immunoassays whose cross-reactivity with digoxin metabolites paralleled the pharmacological activity of the metabolites. We measured the immunoreactivity of digoxigenin bis- and monodigitoxosides, digoxigenin, and dihydrodigoxin in four immunoassays and compared the immunoactivities with pharmacological activities from studies involving whole-animal and receptor (Na,K-ATPase)-based assays. Correlation coefficients for comparisons of immunoassay reactivity and human heart receptor reactivities were: ACS, 0.96; TDx, 0.60; Stratus, 0.57; and Magic, 0.42. Comparison with other biological assays showed a similar trend. The major difference in metabolite cross-reactivities among the immunoassays was that of digoxigenin (ACS, 0.7%; TDx, 103%; Stratus, 108%; Magic, 153%), which has approximately 10% bioactivity relative to digoxin. Measured recovery of mixtures of digoxin and metabolites confirmed these findings. We conclude that the monoclonal antibody in the ACS digoxin assay closely mimics Na,K-ATPase in detecting digoxin and its metabolites. This finding provides a basis for developing therapeutic drug monitoring immunoassays capable of approximating the true pharmacological activity of a mixture of drug metabolites.
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PMID:Digoxin immunoassay with cross-reactivity of digoxin metabolites proportional to their biological activity. 792 62


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