scholarly journals Quantitative nephelometric assay for determining myoglobin evaluated

1990 ◽  
Vol 36 (9) ◽  
pp. 1675-1678 ◽  
Author(s):  
J R Delanghe ◽  
J P Chapelle ◽  
S C Vanderschueren
Keyword(s):  
Reliable Method ◽  
High Dose ◽  
Rheumatoid Factors ◽  
Test Results ◽  
Multiple Forms ◽  
Hook Effect ◽  
Tissue Extracts ◽  
The Mean ◽  
Serum Myoglobin

Abstract A recently introduced automated nephelometric immunoassay involving shell/core particles for determination of myoglobin (Behringwerke) was evaluated with the BNA Nephelometer. Method precision was good: the intra-assay CV varied between 1.5% and 6.1%; with daily calibration, the interassay CV ranged between 1.5% and 7.5%. For usual sample dilutions, the assay response varied linearly with myoglobin concentrations up to 23.1 nmol/L. After automatic dilution by the instrument, concentrations up to 2310 nmol/L could be measured without high-dose "hook" effect. Further manual dilution allowed measurement of myoglobin concentrations up to 26,000 nmol/L. Calibration was stable for at least seven days. We detected no significant interferences from hemoglobin, haptoglobin, bilirubin, iodine-containing contrast media, and rheumatoid factors. Treating lipemic samples with Lipoclean (Behringwerke) decreased test results. Simultaneously drawn serum and plasma samples from the same subject showed no consistent differences in myoglobin concentrations. The mean reference myoglobin concentration was 1.380 (SD 0.82) nmol/L for men and 0.878 (SD 0.45) nmol/L for women. In patients with renal insufficiency, serum creatinine values were moderately related to serum myoglobin values (r = 0.465). Although a commercial radioimmunoassay (Byk-Sangtec) and the nephelometric assay intercorrelated well (r = 0.929), values obtained by nephelometry were significantly lower (P less than 0.05). By both assays, results for heart and skeletal muscle tissue extracts showed no correlation, a finding that suggests the existence of multiple forms of myoglobin in human tissues. We conclude that immunonephelometry is a rapid, practical, and reliable method for measuring myoglobin in serum.

Rapid determination of serum myoglobin with a routine chemistry analyzer

1993 ◽  
Vol 39 (4) ◽  
pp. 653-658 ◽  
Author(s):  
A J Bakker ◽  
D A Boymans ◽  
D Dijkstra ◽  
J P Gorgels ◽  
R Lerk
Keyword(s):  
Predictive Value ◽  
Rapid Determination ◽  
Reference Interval ◽  
High Dose ◽  
Reference Limit ◽  
Hook Effect ◽  
Upper Limit ◽  
Upper Reference Limit ◽  
Serum Myoglobin

Abstract A turbidimetric immunoassay system (Turbitime system, Behringwerke AG) allows rapid determination of myoglobin in serum. We adapted the reagents for this myoglobin assay (Turbiquant myoglobin) for use with a Hitachi 717 analyzer. No high-dose hook effect was observed up to 15,000 micrograms/L. Interassay CVs were 4.6% (mean = 72.0 micrograms/L; n = 9) and 2.5% (mean = 365.6 micrograms/L; n = 11). The calibration curve was stable for at least 1 month. Hemolysis did not interfere, and turbidity from lipemia interfered only when absorbance exceeded 2.0 A. Results of this method (y) correlated well with those by the Turbitime method (y = 1.256x - 44.1 micrograms/L; n = 91; r = 0.991) and by a commercially available radioimmunoassay (Byk-Sangtec; y = 0.739x - 42.2 micrograms/L; n = 94; r = 0.991). The upper limit (95th percentile) of the reference interval for myoglobin was estimated at 57.9 micrograms/L. The positive predictive value for results of myoglobin at admission was 89% with this upper reference limit and 99% with 100 micrograms/L, whereas the negative predictive value was about 60% for both limits.

One Step Closer towards a Reliable Tinnitus Pitch-Match Frequency Determination Using Repetitive Recursive Matching

2020 ◽  
Vol 25 (4) ◽  
pp. 190-199 ◽  
Author(s):  
Daniela Korth ◽  
Andreas Wollbrink ◽  
Robert Wunderlich ◽  
Daniela Ivansic ◽  
Orlando Guntinas-Lichius ◽  
...  
Keyword(s):  
Internal Consistency ◽  
Choice Test ◽  
Test Results ◽  
Outlier Identification ◽  
Excellent Internal Consistency ◽  
One Step ◽  
Matching Procedure ◽  
The Mean ◽  
Very High

Introduction: The determination of the tinnitus pitch-match (PM) frequency is not straightforward but an important audiological assessment recommended for clinical and research purposes. We evaluated repetitive recursive matching using an iPod-based matching procedure as a method to estimate a patient’s PM frequency without audiometric equipment. Methods: One hundred and seventeen patients with chronic tonal tinnitus (uni- and bilateral tinnitus) measured their tinnitus in 10 sessions using a self-administered automated iPod-based procedure comprising a recursive 2 interval forced-choice test. Results: Mean SD of the PM frequency of all participants across sessions was 0.41 octaves. The internal consistency measured by Cronbach’s α was very high (0.8–>0.95). As an example, 7 PMs obtained excellent internal consistency (α = 0.93). The exclusion of the first and/or second session led to more definite PMs with a decreased SD. Outliers were identified by PMs departing 2 SDs (i.e., 0.94 octaves) from the mean variability (n = 5). Conclusion: Repetitive recursive matching together with recommendations for the exclusion of initial and redundant sessions as well as outlier identification and treatment can enable a reliable estimation of the PM frequency.

Recovery-test or immunoradiometric measurement of anti-thyroglobulinautoantibodies

2001 ◽  
Vol 40 (05) ◽  
pp. 155-163 ◽  
Author(s):  
G. Wunderlich ◽  
U. Liepach ◽  
R. Koch ◽  
J. Bredow ◽  
W.-G. Franke ◽  
...  
Keyword(s):  
Nuclear Medicine ◽  
Tumor Recurrence ◽  
High Dose ◽  
Immunoradiometric Assay ◽  
Clinical Value ◽  
Recovery Test ◽  
Metastatic Recurrence ◽  
Hook Effect

SummaryThe determination of thyroglobulin (Tg) in the follow-up of differentiated thyroid carcinomas (DTC), is routinely used in nuclear medicine, although some problems, like a disturbed recovery-test (RT) or autoantibodies to thyroglobulin (TgAb), are well known. But it is a controversial issue in literature, whether the determination of TgAb should be performed beside or instead of the RT. Objective: The study compares the clinical value of the determination of both TgAb and RT with sensitive assays. Methods: 356 patients (pts) were investigated. The results were compared to the concentration of Tg in the sera of the pts. 288 pts stayed tumor-free, the remaining 68 pts showed a recurrence (local and/or metastatic) of their DTC. We measured Tg (with RT) using an immunoradiometric assay (Tg-IRMA; SELco® Tg; Fa. Medipan Diagnostica GmbH) and TgAb using a direct assay (CentAK® anti-Tg; also from Fa. Medipan). Results: The prevalence of TgAb, and of disturbed RT respectively, in the whole population of DTC-pts was 7,6%, in the subgroup of tumor-free pts 6,6%, and in the remaining pts with tumor-recurrence 11,8%, respectively 2,0%, 1,7% and 2,9%. In a significantly higher percentage of pts with local/metastatic recurrence, both a positive TgAb (p <0,001) and a disturbed RT (p <0,05) were found. 7/68 pts with tumor-recurrence but Tg <1 ng/ml showed positive TgAb, only 2/7 had a disturbed RT. In this group, no patient with Tg >1 ng/ ml demonstrated either positive TgAb or disturbed RT (p <0,001 and p <0,05). Conclusion: The determination of TgAb in the follow-up of DTC is necessary, because it supports a suspicion to tumor-recurrence in pts with negative Tg. Also the RT is of great value because of a possibly High dose hook-effect.

Automated determination of human choriogonadotropin by use of microparticle capture analysis

1990 ◽  
Vol 36 (3) ◽  
pp. 554-556 ◽  
Author(s):  
D S Trundle ◽  
P P Chou ◽  
A Raymond
Keyword(s):  
Enzyme Immunoassay ◽  
Dynamic Range ◽  
High Dose ◽  
Hook Effect ◽  
Human Choriogonadotropin ◽  
Microparticle Enzyme Immunoassay ◽  
Automated Determination

Abstract We evaluated a new microparticle enzyme immunoassay (MEIA) for human choriogonadotropin (hCG) in serum. This hCG assay is fully automated for the Abbott "IMx System," which has a dynamic range extending to 100,000 int. units/L. We tested 321 patients' sera, with hCG values ranging between 0 and 196,000 int. units/L by both the IMx hCG (y) and the Hybritech Tandem-E hCG (x) assays. Results correlated well (r = 0.972, slope = 0.87, y-intercept = 0.7). The IMx hCG assay is sensitive (0.21 int. units/L) and precise (CVs 2.4-8.7% for various hCG concentrations). No carryover to subsequent specimens was observed when specimens with values up to 10(6) int. units/L were tested, nor was any high-dose "hook" effect noted. The IMx hCG assay, which is specific for intact hCG molecules, is rapid (one to six samples in 17 min) and is a valid automated alternative to enzymatic and radioisotopic methodologies.

Importance of simultaneous determination of coproporphyrin and hemoglobin in contaminated amniotic fluid.

1986 ◽  
Vol 32 (5) ◽  
pp. 877-878 ◽  
Author(s):  
J Francoual ◽  
A Lindenbaum ◽  
C Benattar ◽  
M Dehan ◽  
H Cohen ◽  
...  
Keyword(s):  
Amniotic Fluid ◽  
Simultaneous Determination ◽  
Biochemical Analysis ◽  
Reliable Method ◽  
Visual Examination ◽  
Mean Values ◽  
The Mean ◽  
Comparison Of The Results

Abstract To detect the presence of meconium and blood, we determined coproporphyrin and hemoglobin in 78 amniotic fluid samples, classified according to their visual aspect as clear (n = 45) or meconium-stained (n = 33). Among the 33 samples visually judged as meconial, a comparison of the results of their biochemical analysis with the mean values for clear amniotic fluids showed that only five of the 33 were contaminated solely with meconium. Seven others were exclusively bloody, and 19 were meconial and bloody. In two, the contaminant was neither meconium nor blood. Evidently, when the fluid is brownish, simple visual examination does not suffice for distinguishing meconium from old blood or other pigments. We propose a simple, rapid, and reliable method for simultaneously measuring contamination with meconium or blood.

scholarly journals Investigation of the unfused cross cylinder test as an alternative method for the determination of spherical distance refraction end points

2020 ◽  
Vol 79 (1) ◽  
Author(s):  
Nkalebetja T. Makgaba ◽  
Solani D. Mathebula
Keyword(s):  
Adult Population ◽  
Test Results ◽  
End Points ◽  
Room Illumination ◽  
End Point ◽  
Cylinder Test ◽  
Significant Difference ◽  
Young Adult Population ◽  
The Mean

Background: The duochrome test is commonly used to refine the final sphere in refraction at different stages of a subjective refraction. The unfused cross cylinder test is mainly used to determine the near reading addition with a combination of astigmatic lenses.Aim: To investigate if the unfused cross cylinder test can be adapted for distance in finding the spherical end point for distance prescription.Setting: The study was conducted at an Optometry Clinic, University of Limpopo, South Africa.Methods: Fifty-one non-presbyopic subjects aged between 18 and 25 years were examined. The duochrome and unfused cross cylinder examinations were performed monocularly under normal (bright) and dim room illumination.Results: There was no significant difference in the spherical end point determined with either the duochrome or unfused cross cylinder tests (p ≥ 0.05). The mean spherical end points as determined with the duochrome test were −0.09 ± 0.39 diopre sphere (DS) (range: −0.20 to 0.12 dioptres [D]) in bright room illumination and −0.05 ± 0.38 DS (range: −0.16 D to 0.05 D) in dim illumination. The mean spherical end points for the unfused cross cylinder tests were −0.29 ± 0.39 DS (range: −0.18 D to 0.40 D) and −0.32 ± 0.43 DS (range: –0.44 D to –0.19 D) in room dim illuminations, respectively.Conclusion: The unfused cross cylinder test results as performed in this study may provide an accurate measurement of the spherical end point in a young adult population. We recommend the unfused cross cylinder test to be used in normal (bright) room illumination as an alternative to the duochrome test in the determination of distance refractive error.

scholarly journals Anthropogenetic variability in the groups of homo- and heterosexually oriented individuals

Genetika ◽  
2015 ◽  
Vol 47 (2) ◽  
pp. 765-776
Author(s):  
Suzana Cvjeticanin
Keyword(s):  
Genetic Variability ◽  
Population Genetic ◽  
Control Group ◽  
Population Genetic Study ◽  
Test Results ◽  
Mean Values ◽  
Significant Difference ◽  
The Mean ◽  
Distribution Type

This population-genetic study compares morphophysiological and genetic variability in a group of homosexually oriented individuals from Serbia (N=96) with control group of heterosexual individuals (N=96) using a test of determination of homozygously recessive characteristics in humans (HRC-test). Results of our study revealed a statistically significant difference in the mean values of genetic homozygosity (control group 5.0+0.2 ; homosexuals 3.4 +0.1 HRCs, out of 20 observed characteristics) the differences in the distribution type, as well as in the variances of presence of specific combinations of such traits. These results suggest a complex polygenic difference between two observed systems. There is no difference in the degree of genetic homozygosity between the genders in each tested group of individuals. However, both homosexually oriented females and males have significantly lower mean values of HRCs compared to female and male heterosexuals.

Patterns of lactate dehydrogenase isoenzymes 1 and 2 in serum of patients performing an exercise test.

1989 ◽  
Vol 35 (2) ◽  
pp. 301-303 ◽  
Author(s):  
Z Rotenberg ◽  
I Weinberger ◽  
A Sagie ◽  
J Fuchs ◽  
E Davidson ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Exercise Test ◽  
Test Results ◽  
Normal Range ◽  
St Depression ◽  
Negative Results ◽  
Ratio Determination ◽  
The Mean ◽  
Lactate Dehydrogenase Isoenzymes

Abstract Values for total lactate dehydrogenase (LD, EC 1.1.1.27) activity and LD isoenzymes were determined in serum from 56 patients and 40 healthy subjects before and 24, 48, and 72 h after they performed an exercise test. The mean (for all four times) total LD activity concentration and proportion of LD-2 were within the normal range for all 96 subjects. Mean LD-1 values for serum, although within the normal range in all subjects, were significantly higher in patients with positive exercise test results than in subjects with negative results: 75 (SD 12) U/L in 35 patients with ST depression greater than 2 mm; 63 (SD 14) U/L in 16 patients with ST depression of 1-2 mm; 43 (SD 11) U/L in subjects with negative test results, by 48 h after the test. The LD 1:2 ratio was also markedly higher in the group of patients with positive test exercise results, especially in those with ST depression greater than 2 mm (1.02, SD 0.06), compared with those subjects with negative results (0.60, SD 0.04). A similar trend was also found 24 and 72 h after the exercise test. We conclude that exercise-myocardial ischemia may lead to an increased LD 1:2 ratio in serum, and demonstrate a correlation between the degree of ischemia and the LD 1:2 ratio. Determination of the LD 1:2 ratio, even in the presence of normal total LD activity, may assist in the clinical evaluation of patients performing an exercise test.

Determination of Resistance to Abrasive Wear. X. Investigation of the Durability of a Bonded Abrasive Wheel on the Du Pont Machine

1949 ◽  
Vol 22 (1) ◽  
pp. 264-268 ◽  
Author(s):  
R. G. Newton ◽  
J. R. Scott
Keyword(s):  
Abrasive Wear ◽  
Test Results ◽  
Volume Loss ◽  
Abrasive Wheel ◽  
Abrasive Particles ◽  
Significant Difference ◽  
Statistical Planning ◽  
The Mean ◽  
Test Result

Abstract The results reported here entirely confirm those of Lambourn, who found that marked deterioration occurred with all the types of abrasive wheel which he used. In the present investigation on a bonded wheel, it was concluded that the wheel was appreciably less abrasive after each period of. 50 hours' wear, while Lambourn concluded that one side of a wheel can be used for a period of two months when subjected to 40 hours of wear per week. Lambourn also concluded that the deterioration is caused by smoothing or disintegration of the abrasive particles and not by clogging with rubber dust, and points out that variation in abrasive wear can be compensated by daily tests on samples of a standard compound. He also states that a grain coarser than 24 should not be used, since the abrasion is too rapid. Since the standard emery papers vary among themselves, and the bonded abrasive wheel deteriorates when it is used, it is evident that attention should be paid to the statistical planning of these tests, so that these factors can be reduced or eliminated. The coefficient of variation of a test result, i.e., the mean of three 10-minute runs, each on duplicate specimens, (six individual readings) as normally measured, seems to be independent of the type of abrasive employed (emery papers or bonded disc) and the uncertainty of the result is about ±5 per cent when measured on the basis of volume loss per hour and about ±3.5 per cent when determined as the volume loss/H.P.-hr. Test results will therefore be required to differ by about 7 and about 5 per cent, respectively, for a significant difference to be demonstrated.

scholarly journals Sex and side determination of human hip bone by metric parameters of its posterior border

2013 ◽  
Vol 02 (01) ◽  
pp. 016-021
Author(s):  
Sarita R Margam ◽  
Megha A Doshi ◽  
Surekha D Jadhav ◽  
Raosaheb J Patil ◽  
Manoj P Ambali
Keyword(s):  
Sex Determination ◽  
Ischial Tuberosity ◽  
Test Results ◽  
Posterior Border ◽  
Bone Material ◽  
Significant Difference ◽  
The Mean ◽  
Two Parameters ◽  
Superior Border

Abstract Background: Identification of sex from skeletal remains is of medico-legal and anthropological importance for forensic experts, anthropologists and anatomists. Hip bone is considered as an ideal bone for sex determination as it provides the highest accuracy levels for sex determination. Aims: To determine the sex and side of the human hip bones by using different metric parameters of posterior border of hip bone. Material and methods: In present study, 200 (100 males and 100 females) dried adult human hip bones of known sex were collected. Two parameters were studied and statistically analysed by paired and unpaired 't' test. Results: In males, distance from the posterior superior iliac spine to the superior border of ischial tuberosity was the discriminant criteria to sex the hip bones while in females, it was distance between the posterior inferior iliac spine (PITS) to ischial tuberosity (IT). Statistically significant difference between the mean related to side were seen in both the variables. Conclusion: These two parameters can be used for sexual dimorphism as well as side determination of human hip bones or its fragments.

Sign in / Sign up

Export Citation Format

Share Document