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Biomedical subjects

K O Ash

Publications and source records attributed to K O Ash.

At least 55 records · Page 3Linked to original sources
PubMed1984

A simplified method for simultaneously determining countertransport and cotransport in human erythrocytes.

Both sodium countertransport and sodium-potassium cotransport are altered in erythrocytes from some hypertensive subjects and their relatives. Lithium can substitute for sodium in both of these transport mechanisms; they can then be monitored as sodium-lithium countertransport and lithium-potassium cotransport. Using erythrocytes loaded with lithium, we can determine both transport systems simultaneously by monitoring the rate of lithium efflux into three media: (1) NaCl, (2) MgCl2 and (3) MgCl2 with furosemide. The difference between the effluxes into NaCl and MgCl2 is the sodium-lithium countertransport; the difference between the effluxes into MgCl2 with and without the cotransport inhibitor furosemide is the lithium-potassium cotransport. At the intracellular Li concentrations used in these experiments, lithium-potassium cotransport is a linear function of the Li+ concentration and can be expressed by the equation for a first order reaction. The rate constant can be calculated by dividing the lithium-potassium cotransport by the intracellular lithium concentration and correlates well (r = 0.80, n = 30) with sodium-potassium cotransport measured by Dagher and Garay's method. The simultaneous measurement of countertransport and cotransport requires much less time, effort and material than measuring the two transports separately.

Biological Transport↗
PubMed1984

Genetic analysis of sodium-lithium countertransport in 10 hypertension-prone kindreds.

The rate of sodium-lithium countertransport (SLC flux) across red cell membranes has been reported to be elevated in hypertensive persons and their relatives as compared to normotensive individuals without family histories of hypertension. We have investigated the inheritance of this trait in 434 persons from 10 kindreds. Relatives show positive correlation of SLC flux values, but there is no spouse-spouse correlation. Pedigree analysis favors a model of polygenic inheritance over models of major-gene inheritance. Major-gene index statistics and offspring-between-parent statistics provide similar results. The proportion of total phenotypic variance that is attributable to polygenic differences between persons is estimated at 71%. The SLC flux values of hypertensive persons in this study population are lower than those reported from Boston, but are similar to those reported from Europe. We found a broad overlap of SLC flux values for hypertensive and normotensive persons. We conclude that SLC flux probably is not useful as a preclinical marker for essential hypertension.

Adolescent↗
PubMed1984

The inheritance of high density lipoprotein cholesterol and apolipoproteins A-I and A-II.

A large pedigree was ascertained through cases of early myocardial infarction. High density lipoprotein cholesterol and apolipoproteins A-I and A-II were measured on family members. Likelihood analysis, using the polygenic/major gene mixed model, provided no evidence that major loci play a role in determining the levels of any of the three measurements. Heritability estimates, assuming polygenic inheritance, were 0.59 and 0.26 for HDL-C level and A-II level, respectively. No evidence of genetic transmission of A-I level was found.

Adult↗
PubMed1984

Turbidimetric measurement of total urinary proteins: a revised method.

A turbidimetric method for the determination of total urinary proteins is proposed that uses a specimen blank for each urine. The precipitant, trichloroacetic acid (TCA), is introduced into the blank and the sample in the same amount. The blank is the supernatant of the TCA-treated urine for each specimen. Turbidity is measured by reading the 420-nm absorbance 35 minutes after the TCA addition when the turbidity curves for most urine samples plateau. This improved method was compared with an established procedure that uses water to prepare the blanks and that measures turbidity 5 minutes after the TCA addition. Of the 69 urine specimens that were analyzed by the two methods, the revised procedure yielded higher values (greater than or equal to 150%) for 5 samples, while 21 samples had lower values (less than or equal to 50%). In the latter group, four cases would have been classified erroneously as having significant proteinuria by the established method.

Humans↗
PubMed1984

The relationship of plasma ionized calcium to cardiovascular disease endpoint and family history of hypertension.

Plasma ionized calcium and total calcium were measured on 271 individuals from 34 Utah pedigrees divided into groups defined by the method of pedigree ascertainment: 1) hypertension clusters, 2) early stroke death clusters and 3) clusters of early heart attack deaths. Normotensive individuals were also categorized by family history of hypertension. Members of stroke cluster pedigrees had higher mean plasma ionized Ca2+ than either hypertension pedigrees (p less than 0.05) or coronary artery disease pedigrees which had the lowest concentrations (p less than 0.001). Within the normotensive group, those subjects with a positive family history of hypertension exhibited significantly higher plasma ionized Ca2+ (2.18 +/- 0.10 (S.D.) mEq/l) than individuals without a family history of hypertension (2.12 +/- 0.08 mEq/l, p less than 0.01). In medicated hypertensives, both ionized (p less than 0.05) and total (p less than 0.01) plasma calcium were higher than calcium levels in the normotensive negative family history subjects. Plasma ionized Ca2+ in the adult normotensives (N = 134) had significant age corrected positive correlations with plasma sodium (r = 0.25, p less than 0.01), potassium (r = 0.29, p less than 0.001) and erythrocyte sodium-lithium countertransport values (r = 0.20, p less than 0.05). These findings provide additional evidence that plasma ionized calcium concentrations may be important to help define the heterogeneity of hypertension in adult Americans.

Adult↗
PubMed1984

A microassay for serum dialyzable calcium and magnesium by ion chromatography.

We describe a method for determining dialyzable calcium and dialyzable magnesium in 50-microliter volumes of routinely handled aerobic serum. Calcium and magnesium concentrations were measured by ion chromatography after a 1-min equilibrium dialysis. Day-to-day precision (coefficient of variation, CV) was 3.8% for dialyzable calcium and 4.5% for dialyzable magnesium. Dilution of serum with water 1:1 as well as storage at 4 or -20 degrees C had no significant effects. Reference intervals for dialyzable calcium (58.1-68.1 mg/l) and magnesium (12.3-17.1 mg/l) were determined for 26 healthy adults. Lack of interference and the ability to determine simultaneously several analytes on a single specimen are advantages of the chromatographic method.

Adult↗
PubMed1984

Comparison of serum total calcium, dialyzable calcium, and dialyzable magnesium in well and sick neonates.

We studied the relation of serum total calcium, dialyzable calcium, and dialyzable magnesium in 61 well and sick newborn infants aged 7-76 h. The infants' serum total calcium, dialyzable calcium and magnesium concentrations (ion chromatography method) were studied in comparison with the infant's history and sickness scale. We found that serum total calcium and dialyzable magnesium were lower in sick infants compared to well infants. Both serum total and dialyzable calcium concentrations initially decreased and then increased by about 30 h of age. Serum dialyzable magnesium concentrations increased with our infants' age. Serum total calcium values correlated significantly with the infant's birth weight, gestational age, 1-min Apgar score, respiratory distress, severity of sickness, serum bilirubin and sodium concentrations.

Aging↗
PubMed1984

Creatine kinase and lactate dehydrogenase isoenzymes in serum of patients suffering burns, blunt trauma, or myocardial infarction.

Medical records of 53 burn and trauma patients were reviewed to assess the possibility of myocardial damage. Except for electrophoretically detectable creatine kinase MB isoenzyme, none showed evidence of myocardial injury. Lactate dehydrogenase isoenzyme tests, electrocardiograms, myocardial pyrophosphate scans, clinical course, and results of (two) autopsies were all negative for myocardial necrosis or ischemia. Types of patient, number, mean peak value (U/L) for serum creatine kinase, and ranges of percentage MB isoenzyme were as follows. Burns from direct electrical contact: 28, 16 600, 0-29; electrical flash or other thermal burns: 10, 4340, 0-22; blunt trauma (mostly from automobile accidents): 15, 3430, 0-18; myocardial infarction: 57, 1520, 4-46. Evidently creatine kinase MB isoenzyme is nonspecific in burn and trauma patients and should not be the only test result used to assess myocardial involvement.

Adolescent↗
PubMed1983

The influences of sample distribution and age on reference intervals for adult males.

This investigation was designed to improve reference information and to evaluate the influences of sample distribution and age on the derived reference intervals. Specimens from 127 men were collected after a 12- to 14-hour fast and analyzed by 60 different laboratory procedures. Differences in the reference intervals derived, using three separate statistical methods, appeared to be unimportant clinically, but the percentile method was preferred because it required no assumptions concerning the frequency distribution. Relationships between age and analyte concentrations were examined by linear regression analysis, and the analytes were placed in one of three groups, according to the significance of this relationship: greatest significance (P less than or equal to 0.01), 18 analytes; intermediate significance (0.01 less than or equal to P less than or equal to 0.05), 12 analytes; and least significance (P greater than 0.05), 30 analytes. The age-related changes for each analyte were evaluated according to analytic variation, population dispersion, and clinical relevance. Age-dependent reference intervals for adult males are recommended for albumin, cholesterol, phosphorus, and sedimentation rate.

Adult↗
PubMed1983

Sodium-lithium countertransport in erythrocytes of hypertension prone families in Utah.

Sodium-lithium countertransport was measured in July 1980-December 1982 in 841 persons from 48 Utah families prone to hypertension. Mean countertransport in 54 hypertensive adults (0.32 +/- 0.01 standard error of the mean) was significantly higher than in 511 normotensive adults (0.26 +/- 0.005, p less than 0.001) but with much overlap between the two groups. This difference was observed in both men and women. Only 26% of the subjects with essential hypertension had values above 0.40 (considered "high" by most other published reports). High values were seen in only 2% of 276 youths under age 18 years in contrast to 11% of the normotensive adults (p less than 0.001). Among normotensive adults, countertransport was higher in men than women, and correlated with weight, diastolic blood pressure, and age (all significant at p less than 0.01). None of these findings were seen in youths. In multivariate analyses, only weight continued to be significantly correlated with countertransport. The difference between countertransport levels in hypertensive vs. normotensive adults remained significant even after adjusting for weight. While confirming other reports of higher mean sodium-lithium countertransport in persons with essential hypertension, this study shows much overlap of values between groups and potential confounding effects of weight. When the authors compared their results with studies that show little overlap between hypertensive and normotensive adults, they found that the data for the normotensive adults in this study are similar to those reported in the other studies, but that the hypertensive adults include a larger percentage of individuals with low countertransport values.

Adolescent↗
PubMed1983

Serologic investigation of an outbreak of hepatitis A in a rural day-care center.

We studied an outbreak of hepatitis A in a day-care center in a rural community where less than 7 per cent of the population possessed anti-HAV. Serotesting for IgM specific antibody to hepatitis A virus identified 78 cases in center attendees, staff, and families. Thirty-five per cent of the center children were seropositive. In children under age three anicteric infection was at least 17 times more frequent than icteric infection, but in older children and adults icterus was a predominant manifestation of the disease. Clinical suspicion should be high in any day-care child with nausea, emesis, diarrhea, or arthralgia. The low incidence of icterus in infected children suggested that outbreak reports reaching public health departments are likely to be incomplete and poorly indicative of outbreak magnitude. The high frequency of intrafamilial transmission and anicteric infection appeared to justify administration of immune serum globulin to household contacts of center children under age three when a day-care outbreak is detected.

Antibodies, Viral↗
PubMed1983

The effect of diet on ouabain binding to erythrocytes from obese subjects.

Ouabain binding to erythrocyte membranes is increased in obese subjects. Three study groups are compared: 14 reference subjects, 102 +/- 16% of ideal weight; 9 obese on unrestricted diets, 207 +/- 16% of ideal weight; 11 obese on restricted diets, 202 +/- 35% of ideal weight. A reproducible (CV = 11.3%) ouabain-binding assay is used to measure Na+-K+ ATPase sites in erythrocyte membranes. The number of binding sites per red blood cell for obese subjects on unrestricted diets, 431 +/- 30, is greater than for the reference group, 346 +/- 66 (p less than 0.01), or for obese subjects on restricted diets, 371 +/- 68 (p less than 0.05). These data suggest that caloric intake influences the number of Na+-K+ ATPase sites. Scatchard plots indicate only one type of binding site for ouabain with an affinity constant of about 3 X 10(8) M-1.

Adolescent↗