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Biomedical subjects

D E Bee

Publications and source records attributed to D E Bee.

At least 37 records · Page 2Linked to original sources

Extended clinical trial and evaluation of glucose determination with the Eastman Kodak Ektachem GLU/BUN Analyzer.

We followed the "abbreviated precision protocol" of the National Committee for Clinical Laboratory Standards for the evaluation of precision, accuracy, and carryover in analyses for glucose with the "Ektachem." We analyzed 760 clinical samples by this technique, by the FDA Proposed Class Standard glucose reference method, and with the Beckman System I GLU/BUN Analyzer. Precision and accuracy were estimated for 500, 1000, 1200, 1500, and 3000 mg/L glucose concentrations in 100, 30, or 20 microL of serum or plasma. Potential interference of 19 compounds was evaluated. Random error (1.965 X SD) was 22, 30, 34, 40, and 88 mg/L. Systematic error was 8, 1.5, -2, -5, and -27 mg/L. Total analytical error was 30, 32, 36, 46, and 110 mg/L for analysis of 100 microL of serum at the above-stated glucose concentrations. The greatest interference (-39 mg/L) in the glucose (at 1200 mg/L) determination was caused by L-ascorbate (40 mg/L). Glucose concentrations as determined with the Ektachem were found to be linearly related to the expected concentration up to at least 5660 mg/L. Carryover was not statistically significant.

Blood Chemical Analysis↗

Extended clinical trial and evaluation of urea nitrogen determination with the Ektachem GLU/BUN analyzer.

We followed the "abbreviated precision protocol" of the National Committee for Clinical Laboratory Standards for the evaluation of precision, accuracy, and carryover in analysis for urea nitrogen with the multilayer film analysis system ("Ektachem"). We analyzed 456 clinical samples with this instrument, by the manual urease/glucose dehydrogenase method, and with the Beckman System I GLU/BUN Analyzer. Precision and accuracy were estimated for 50, 220, 270, and 500 mg/L urea nitrogen concentrations in 100, 30, or 20 microL of serum. Potential interference of 15 compounds was evaluated. Random error (defined as 1.965 X SD) was 7, 10, 12, and 18 mg/L. Systematic error was 3, 4, 5, and 15 mg/L. Total analytical error was 11, 14, 17, and 34 mg/L for analysis of 100 microL of serum at the above-stated urea nitrogen concentrations. The greatest interference (6 mg/L) was caused by ethanol (300 mg/L) and by hemoglobin (500 mg/L) in the urea nitrogen (at 260 mg/L) determination. Urea nitrogen concentration, as determined with the Ektachem was linearly related to the expected concentration, at least up to 1187 mg/L. Carryover was not statistically significant.

Autoanalysis↗

Analysis of methods to construct nomograms in uroflow studies.

A Monte Carlo simulation study to compare the effect of population form on three methods of nomogram construction was performed by taking 2000 random samples of size 5, 20, 50, 100, and 200 from populations with known percentiles. The 10th percentile was estimated by each of the three construction procedures. The three procedures compared were the upper 95 per cent nonparametric tolerance limit technique, the usual percentile approach, and a method which assumes a Gaussian (normal) distribution. Tenth percentile nomograms, classified by volume voided, were calculated by each of the three procedures for maximum flow rate determinations from 356 normal males of ages 1 to 12 years with body surface areas less than 1.1 m2. Nomograms of the three methods are validated with evaluations from two other groups of male children consisting of known abnormals with radiologically proven urethral obstructions and known normals who had repeated at home uroflow rates. The nonparametric tolerance limit approach gives conservative estimates and is superior in all cases from the standpoint of reducing false-negative results.

Child↗

Porcine malignant hyperthermia--failure of dantrolene dose response to diagnose susceptibility (halothane effect).

Dantrolene, a skeletal muscle relaxant, has been proven prophylactic and therapeutic for malignant hyperthermia (MH) in swine. This study examined the feasibility of using a dantrolene dose response as measured by indirectly evoked foretoe twitch depression as a means to safely discriminate MH susceptibility in swine. The effect of halothane on the dantrolene response was quantified. Subjects were five Poland China malignant hyperthermia susceptible (MHS) and five Hampshire malignant hyperthermia resistant (MHR) swine. Dantrolene dose response was determined twice in each anaesthetized subject, once with thiopentone and subsequently with thiopentone and halothane. Dantrolene in incremental doses, 0.15 mg.kg-1, was given to a cumulative dose of 2--3 mg.kg-1. Under thiopentone anaesthesia, the dantrolene dose responses were similar in MHS and MHR animals. The presence of halothane augmented dantrolene twitch depression in MHS but not MHR animals when compared to their response under thiopentone. Under halothane, the MHS animals had significantly augmented dantrolene response compared to MHR pigs, but three MHS animals had developed the MH syndrome prior to receiving dantrolene. We conclude that dantrolene muscle relaxant dose response cannot be used as a diagnostic test for MHS in swine. Halothane augments dantrolene twitch depression in MHS swine.

Animals↗

Parameters of gas urethral pressure profiles: part II.

Parameters of the carbon dioxide urethral pressure profilometry were examined in detail previously for reproducibility within subjects. In the current study we have extended that analysis to determine the relationship of these parameters between patient subgroups. Mean values for non-spina bifida male subjects showed the same pattern of increase across age groups, regardless of the measured parameter. These increases were significant for continence and functional lengths but not for closure pressure. Male subjects with spina bifida showed mixed responses across age but age was not a statistically significant factor for any of the 3 parameters. Female subjects were quite uniform in the mean values across age for continence and functional lengths regardless of diagnosis. Mean values for female subjects were not uniform for closure pressure and tended to decrease with age in contrast to continence and functional lengths. The parameter continence length has a between subject standard deviation that is relatively stable across age, sex and pathology, and may be used for a basis of comparison. However, standard deviations for functional length is least variable in most subgroups of sex, age and diagnosis.

Adolescent↗

Catecholamine-induced hyperglycemia in dogs: independence from alterations in pancreatic hormone release.

Although isoproterenol is a very effective hyperglycemic agent in dogs, other species such as rats, baboons and man are resistant to this effect. In each of these species catecholamines exert pronounced effects on insulin and glucagon release from the pancreas. In man, baboons, and rats catecholamine-induced alterations in pancreatic hormone release indirectly influence the hyperglycemic response to these amines: glucagon release supports and insulin release limits hyperglycemic responses. In contrast, the present study demonstrates that in dogs catecholamine-induced hyperglycemic responses are relatively independent of concurrent alterations in pancreatic hormone release. In dogs isoproterenol produces hyperglycemia equal to or greater than responses to epinephrine despite large increases in insulin release produced by isoproterenol. Moreover, catecholamine-induced hyperglycemia is not significantly altered when insulin and glucagon release are blocked with somatostatin.

Animals↗

Factors influencing access to primary health care via school health services.

The school health and community primary health care contacts were studied for a group of elementary school children who have sociodemographic characteristics often associated with poor access to primary health services. The school system is engaged in a demonstration project that attempts to link the home with community and school services. Visits to the school health room accounted for 85% of all contacts. A visit rate of 1.13 visits/child/year occurred at primary care sites. Ethnicity is the single most important predictor of use of school health services, followed by family status and number of visits for primary health care in the community. In contrast, use of community primary care facilities is best predicted by socioeconomic status (SES), family status, and sex. The patterns of care received by the population were characterized. Children whose care was initiated, referred, or facilitated by the school were designated as receiving "interactive" care, which occurred mostly among minority and lower SES children. The data suggest that the school provides access to preventive health care for all children and facilitates care for segments of the population that usually have difficulty achieving access to the health care system.

Child↗

The impact of severely damaged cells in cytogenetic research.

In a large multilaboratory cytogenetic study of interlaboratory variations using 4 dose levels of triethylenemelamine and a control, a severely damaged cell was operationally defined as a cell which contained at least 10 aberrations of any type. A review of this study suggested that the use of this definition introduced a bias in the measurement and interpretation of results for the other cytogenetic categories studied. As a result, the original severely damaged cells were carefully reanalyzed to investigate the characteristics of this bias and to seek procedures to minimize or eliminate it. Results characterize this bias and demonstrate that when a severely damaged cell is defined as one containing at least 20 aberrations and those aberrations in the remaining non-severely damaged cells are classified by specific type, the bias is significantly reduced and chromosome analysis can be improved as a test system.

Chromosome Aberrations↗

Parameters of gas urethral pressure profiles: Part I.

Carbon dioxide urethral pressure profiles were analyzed under the same conditions for 113 spina bifida and 87 non-spina bifida patients categorized by sex and age. Either duplicate or triplicate measurements were obtained from each patient for parameters of continence length, closure pressure and functional length. The degree of reproducibility of each parameter varied depending on age, sex and diagnosis. Except for 1 age-sex category closure pressure exhibited the smallest degree of relative variation for spina bifida patients. Results for non-spina bifida patients were mixed in that the measurement of no one parameter resulted in a uniformly smallest degree of relative variation. Reproducibility based on within patient variability generally was least for the continence length.

Adolescent↗

Temperature perturbation studies of sarcoplasmic reticulum from malignant hyperthermia pig muscle.

The effects of varying temperatures from 25 degrees to 37 degrees C on calcium binding characteristics of sarcoplasmic reticulum from malignant hyperthermia-susceptible (MHS) and control pig muscle were examined. Two groups of MHS pigs were included: those with high susceptibility to malignant hyperthermia (MHS group) and a cross-bred, less susceptible group (MHX). At 25 degrees C, calcium binding was lower for MHS than for controls and MHX. As temperature was increased by 2 degrees C jumps, calcium binding decreased in all sarcoplasmic reticulum fractions. At 35 degrees C a sharp decrease in calcium binding occurred in the MHS and MHX fractions. The sharp decrease in calcium binding at 35 degrees C differentiated the MHS and MHX fractions from controls. The initial velocity (Vi) for calcium binding was lower in MHS fractions between 25 degrees and 35 degrees C when compared with MHX and controls. All fractions had increased Vi values as temperature increased from 25 degrees to 35 degrees C. From 35 degrees to 39 degrees Vi for controls increased markedly. In contrast, Vi for the MHX fraction decreased as temperature exceeded 35 degrees C. These temperature effects on calcium binding characteristics of sarcoplasmic reticulum from MHS and MHX muscle may be indicative of a membrane transition that impairs calcium binding.

Animals↗

Glucosuria: accuracy and precision of laboratory diagnosis by dip stick analysis.

Two urine dip-stick assays for glucose were studied and compared to a quantitative hexokinase procedure. We determined sensitivity, specificity, predictive value of "normal" and "abnormal" dip stick results, assay efficiency, technologist precision, and method association. Precision was poor. Attempts to estimate urine glucose concentration with the dip sticks frequently produced gross inaccuracies. We believe the dip stick glucose assay should be considered qualitative only; as a qualitative test, the dip sticks are fairly efficient at distinguishing glucose concentrations of less than 0.3 g/L from concentrations greater than 0.3 g/L.

Clinical Laboratory Techniques↗

Hemoglobinuria and hematuria: accuracy and precision of laboratory diagnosis.

Five methods of assessing blood in urine were studied and compared: sedimentation count, hemacytometry, "Clini-lab" reagent strip and "N-Multistix" and "ChemStrip-8" dipsticks. The minimum sensitivity of two commercially available urine dip-stick procedures for blood was established. The study includes method association, assay variation among and within technologists, accuracy, precision, and sensitivity. Our results demonstrate generally poor association between results by the dip-stick procedures and the hemacytometer or sedimentation count. Results by the last two procedures also showed very poor association with each other.

Clinical Laboratory Techniques↗