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N Q Hanson

Publications and source records attributed to N Q Hanson.

33 records · Page 2Linked to original sources
PubMed1994

Determination of a T/G polymorphism at nucleotide 3206 of the apolipoprotein C III gene by amplification refractory mutation system.

We used the amplification refractory mutation system (ARMS)--a polymerase-chain-reaction-based method--to determine the 3206 T-to-G polymorphism on exon 4 of the apolipoprotein (apo) C III gene. Apo C III is an inhibitor of the enzyme lipoprotein lipase (EC 3.1.1.34). Previous studies have demonstrated that a polymorphism at nucleotide 3175 on exon 4 of this gene is associated with hypertriglyceridemia. We studied 45 hypertriglyceridemic and 46 age-matched controls for the 3206 T-to-G polymorphism. The results showed a significant difference in the distribution of the genotypes with respect to this allele between the hypertriglyceridemic and control individuals. We also determined the presence of the SacI site at nucleotide 3175 in these same individuals and found no significant difference in SacI genotypes between the two groups. This study reaffirms the usefulness of ARMS as a simple, reliable method for detecting mutations and polymorphisms in clinical and epidemiological studies.

Adult↗
PubMed1992

Prevalence of nonclassical congenital adrenal hyperplasia among women self-referred for electrolytic treatment of hirsutism.

Nonclassical congenital adrenal hyperplasia (NCCAH) is well recognized among women who seek medical attention for hirsutism. However, the prevalence of this disorder among women self-referred for electrolytic treatment of hirsutism is unknown. We hypothesized that the prevalence of NCCAH among women attending an electrolysis clinic might be high. By measuring the morning salivary 17-hydroxyprogesterone (17-OHP) as a screening test for NCCAH in 46 women in the follicular phase of their menstrual cycle, we identified 12 subjects with a high basal salivary 17-OHP. Eleven agreed to have a 60-minute Cosyntropin-stimulation test, as did an additional 6 of 9 women with normal basal salivary 17-OHP, but with a particularly high hirsutism score. One of the women with high basal salivary 17-OHP had a 60-minute Cosyntropin response, which was diagnostic of NCCAH. She was of the Ashkenazi Jewish decent, a group previously reported to have a high prevalence of NCCAH. A second woman with high salivary 17-OPH had a Cosyntropin-stimulation response consistent with heterozygosity for 21-hydroxylase deficiency. None of the Cosyntropin-stimulation responses in those chosen for a high hirsutism score were diagnostic. Thus, 1 of 46 (2.2%) of the women who entered our study had unrecognized NCCAH, a prevalence only about 2-fold greater than that reported in the general population. Therefore, we recommend that electrolysis clinics advise clients from ethnic groups known to have a high frequency of NCCAH of the advisability of having a formal medical evaluation for NCCAH.

17-alpha-Hydroxyprogesterone↗
PubMed1987

Immunonephelometry of apolipoprotein B with a centrifugal analyzer.

We developed an automated immunonephelometric assay for the measurement of apolipoprotein B (apo B) with a light-scattering microcentrifugal analyzer. Pretreating specimens with a dilute solution of Tween 20 or triglyceride lipase decreased the nephelometric response of apo B. Polyethylene glycol is included in the reaction mixture, and the reaction is complete within 4 min. The method is precise (CV = 6.5%, mean = 0.68 g/L) and the standard curve is linear to an apo B concentration of 2.8 g/L. Lipemia does not interfere with the method if grossly lipemic specimens are centrifuged to remove chylomicrons.

Apolipoproteins B↗
PubMed1986

Nephelometric assay of apolipoprotein A-I with a centrifugal analyzer.

We developed an automated immunonephelometric assay for quantification of human apolipoprotein A-I (apo A-I) with a fluorescence light-scattering microcentrifugal analyzer. The presence of polyethylene glycol and Tween 20 in the reaction mixture ensures maximum exposure of the antigenic sites of the apoprotein so that immune complex formation occurs more rapidly (reaction is complete within 2 min) and to a greater extent. Lipemia and hemolysis do not interfere with the measurement of apo A-I. The method requires only 10 microL of specimen and is fast and easy to perform. Results vary linearly with apo A-I concentrations to 2.5 g/L. Assay precision (CV) was 3.1% for a specimen with an apo A-I concentration of 1.45 g/L, and the lower limit of detection was 0.15 g/L. Values for a candidate Reference Material agree well with those reported in an international survey (Clin Chem 1985;30:223-8).

Antigen-Antibody Complex↗
PubMed1983

Effect of protein on the determination of total bile acids in serum.

We measured total serum bile acids on a fluorescence-light-scattering micro centrifugal analyzer by the direct enzymatic method with 3 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.50) and with resazurin as a fluorogenic electron acceptor. We found that serum protein has an inhibitory effect on the measurement of bile acids, but this effect was eliminated by adding bovine serum albumin to the reaction mixture in a final protein concentration (12.2 g/L) that was high compared with that contributed by a normal serum specimen. The assay is a sensitive method that reaches equilibrium in 5 min. The method is microscale (5 microL of sample, 150 microL of working reagent), is easy to perform, and is accurate (analytical recovery = 104.1%) and precise (CV = 11.1 and 5.7% on specimens with bile acid concentrations of 7.6 and 35.4 mumol/L, respectively). Normal values are 1-12 and less than 9 mumol/L on nonfasting and fasting individuals, respectively. Pure 3 alpha-hydroxysteroid dehydrogenase must be used: we found several enzyme preparations that gave falsely high values for bile acid.

3-Hydroxysteroid Dehydrogenases↗
PubMed1983

Enzyme inactivation in serum before determination of total bile acids.

Endogenous NADH-generating enzymes must be inactivated before total serum bile acids can be measured accurately by the direct enzymic method. To do this, we pretreat the sera with NaOH, in a final concentration of 0.1 mol/L. Consequently, lactate dehydrogenase activity at least as high as 30 000 U/L is destroyed, obviating blank determinations. Values for bile acid in serum, so obtained, agree with values obtained after pretreatment with heat, an alkali-methanol solution, or sodium pyruvate, but our pretreatment has the advantages of ease, speed, economy, and negligible blank values.

Bile Acids and Salts↗
PubMed1979

alpha-Amylase activity by the Beckman reaction system and suppression by pyruvate.

We evaluated the new Beckman Enzymatic Amyalse-DS Method with maltotetraose as substrate. Our findings indicate that the method is approximately twice as sensitive as the old method involving soluble starch [Clin. Chem. 24, 762 (1978)]. The new method also shows a linear rate of reaction, in contrast to the curvilinear rate previously observed with the old method. The Km with maltotetraose is 0.77 g/L, or about twice that with soluble starch (0.42 g/L). The method correlates well with the Phadebas alpha-amylase method (r = 0.974 and 0.991 on 84 serum and 52 urine specimens, respectively). Of 43 specimens with high concentrations of pyruvate we examined for interference with alpha-amylase activity, only six showed interference when maltotetraose was the substrate. (With both Beckman methods the reaction of pyruvate with NADH produced lactate and NAD+ in the presence of lactate dehydrogenase as contaminant.) Pyruvate interference decreased with increases in (a) the alpha-amylase activity of the specimen, (b) the amount of NADH initially present in the maltotetraose reagent, and (c) the length of time the reconstituted maltotetroase reagent was allowed to stand before being used.

Adolescent↗
PubMed1977

Serial serum creatine phosphokinase MB isoenzyme activity after myocardial infarction. Studies in the baboon and man.

Serum CPK-MB iosenzyme activity was measured serially after mercury embolization of the left circumflex coronary artery in five baboons and after clinical acute myocardial infarction (AMI) in 20 patients. The calculated amount of enzyme released into the baboons' circulation (CPK-MBR) correlated well (r = 0.991) with the amount of MB isoenzyme depleted from the myocardium (CPK-MBD) when a previously determined decay constant (Kd) was used, but not when Kd was calculated from individual curves or when CPK-MM values were used. In clinical AMI, CPK-MMR averaged 97% (0 to 350%) greater than CPK-MBR, probably because of release of MM isoenzyme from nonmyocardial sources. The mean Kd for CPK-MB in patients (0.0012 min-1) was significantly (P less than 0.01) lower than that obtained in the baboon following bolus injections (0.0018 min-1), probably reflecting delayed myocardial release of enzyme. Therefore, in both experimental and clinical AMI, serial samples for CPK-MB activity, but not total or CPK-MM activity, could provide an accurate index of myocardial enzyme depletion.

Animals↗
PubMed1976

Creatine kinase isoenzymes in baboon tissues and organs.

We determined the activity of the isoenzymes of creatine kinase in homogenates of fresh tissues from six baboons. Twenty-six tissues were removed from each baboon and the isoenzymes in them were separated by chromatography on diethylaminoethyl-Sephadex A-50. Total activity was greatest in skeletal muscle (2600 U/g wet weight) followed by myocardium (800 U/g), brain (180 U/g), and the bladder and tissues of the gastrointestinal tract (about 100 U/g). Ten tissues had total activities of less than 20 U/g: trachea, lung, kidney, thyroid, gall bladder, liver, spleen, pancreas, common bile duct, and adrenal. Skeletal muscle contained only the MM isoenzyme; myocardium contained 81% MM isoenzyme, 18% MB isoenzyme, and 1% BB isoenzyme. Except for thyroid and pancreas, all other tissues contained mainly the BB isoenzyme. Tissues of the gastrointestinal tract contained significant (7 to 17%) MB isoenzyme activity.

Animals↗
PubMed1975

Electrophoresis on cellulose acetate and chromatography on DEAE-sephadex A-50 compared in the estimation of creatine kinase isoenzymes.

We have compared two methods for separating the isoenzymes of creatine kinase in serum and measuring their activity: chromatography on diethylaminoethyl-Sephadex A-50, with both continuous and discontinuous gradient elution, and electrophoresis on cellulose acetate. Results by continuous and discontinuous gradient elution correlated well both for tissue extracts and sera. Electrophoresis on cellulose acetate is evidently less sensitive than the chromatographic method for detecting and measuring low activities of the isoenzyme designated MB. We describe how the isoenzymes may be separated by discontinuous gradient elution from microcolumns of the Sephadex and their activity rapidly quantitated by the Rosalki method [J. Lab. Clin. Med. 69, 696 (1967)], with a centrifugal analyzer.

Animals↗