Automated Determination of Serum Hexosaminidase A by pH Inactivation for Detection of Tay-Sachs Disease Heterozygotes

1974 ◽  
Vol 20 (5) ◽  
pp. 538-543 ◽  
Author(s):  
Abraham Saifer ◽  
Guta Perle
Keyword(s):  
Automated System ◽  
Ashkenazi Jewish Population ◽  
Tay Sachs Disease ◽  
Hexosaminidase A ◽  
Ph Inactivation ◽  
The Mean ◽  
Manual Test ◽  
Normal Adults ◽  
Automated Determination

Abstract We have automated a manual test for detection of heterozygotes of Tay-Sachs disease by assay of hexosaminidase A in serum, based on pH inactivation [Clin. Chim. Acta 43, 417 (1973)]. The same manifold is used both for the total hexosaminidase and pH-inactivation (hexosaminidase B) procedures. Automation expedites mass screening of the Ashkenazi Jewish population for carriers of the Tay-Sachs gene (prevalence rate, 1:30), because 100 or more tests can be performed daily. The mean percentage value and range (±2 SD) of hexosaminidase A for normal adults is 68.6 (58-79) and for carriers is 48.8 (39-59) with the automated pH-inactivation procedure. "Presumed carriers" (<53% hexosaminidase A) and individuals in the uncertain range (53 to 58%) should be retested by using leukocytes, to avoid the effect of certain physical ailments, before being labeled as carriers. The same automated system used for this assay can also be used to detect carriers of at least seven other sphingolipidoses for which artificial fluorogenic substrates are available.

Use of Ten Gram Samples of Corn for Determination of Mycotoxins

1988 ◽  
Vol 71 (1) ◽  
pp. 41-43
Author(s):  
Octave J Francis ◽  
George M Ware ◽  
Allen S Carman ◽  
Gary P Kirschenheuter ◽  
Shia S Kuan
Keyword(s):  
Statistical Tests ◽  
Automated System ◽  
Sample Sizes ◽  
Concentration Variance ◽  
Assay Procedure ◽  
Coefficients Of Variation ◽  
The Mean ◽  
Aflatoxin B ◽  
Test Result

Abstract Data were gathered, during a study on the development of an automated system for the extraction, cleanup, and quantitation of mycotoxins in corn, to determine if it was scientifically sound to reduce the analytical sample size. Five, 10, and 25 g test portions were analyzed and statistically compared with 50 g test portions of the same composites for aflatoxin concentration variance. Statistical tests used to determine whether the 10 and 50 g sample sizes differed significantly showed a satisfactory observed variance ratio (Fobs) of 2.03 for computations of pooled standard deviations; paired f-test values of 0.952, 1.43, and 0.224 were computed for each of the 3 study samples. The results meet acceptable limits, since each sample’s r-test result is less than the published value of the |t|, which is 1.6909 for the test conditions. The null hypothesis is retained since the sample sizes do not give significantly different values for the mean analyte concentration. The percent coefficients of variation (CVs) for all samples tested were within the expected range. In addition, the variance due to sample mixing was evaluated using radioisotopelabeled materials, yielding an acceptable CV of 22.2%. The variance due to the assay procedure was also evaluated and showed an aflatoxin B, recovery of 78.9% and a CV of 11.4%. Results support the original premise that a sufficiently ground and blended sample would produce an analyte variance for a 10 g sample that was statistically comparable with that for a 50 g sample.

Automatic Estimation of Urea Using Urease and Alkaline Phenol

1966 ◽  
Vol 12 (6) ◽  
pp. 360-368 ◽  
Author(s):  
B W Wilson
Keyword(s):  
Diffusion Type ◽  
Manual Method ◽  
Automatic Estimation ◽  
Percentage Difference ◽  
The Mean ◽  
Level Of Significance ◽  
Automated Determination

Abstract A method for the automated determination of urea in plasma and urine, using urease and alkaline phenol, proved to have the advantages of speed and precision when compared with a manual method of the diffusion type. The mean percentage difference between results of the two methods did not differ from zero at the 1% level of significance when examined by the † test.

Automated Determination of Acid Phosphatase

1966 ◽  
Vol 12 (4) ◽  
pp. 226-233 ◽  
Author(s):  
Bernard Klein ◽  
Morris Oklander ◽  
Stanley Morgenstern
Keyword(s):  
Acid Phosphatase ◽  
Human Serum ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Prostatic Acid Phosphatase ◽  
Biological Materials ◽  
Automated System ◽  
Automated Determination ◽  
Serum Acid Phosphatase

Abstract A procedure is presented for the automated determination of acid phosphatase activity in biological materials using the Robot Chemist. Although either phenylphosphate and α-naphthylphosphate may be used as substrate in this analysis, the procedure is described in detail for serum acid phosphatase using α-naphthylphosphate in 0.1 M citrate, pH 5.2, since this substrate is more selective for prostatic acid phosphatase in human serum. Enzymically generated aα- naphthol is determined by the Emerson reaction (alkaline aminoantipyrine and ferricyanide), modified for use with this automated system. Correlations are presented between the results obtained on the Robot Chemist and the identical procedure developed for the AutoAnalyzer.

An Automated p-Nitrophenylphosphate Serum Alkaline Phosphatase Procedure for the AutoAnalyzer

1965 ◽  
Vol 11 (9) ◽  
pp. 876-888 ◽  
Author(s):  
Stanley Morgenstern ◽  
Gerald Kessler ◽  
Joseph Auerbach ◽  
Richard V Flor ◽  
Bernard Klein
Keyword(s):  
Alkaline Phosphatase ◽  
Serum Alkaline Phosphatase ◽  
Reaction Rates ◽  
Small Sample ◽  
Automated System ◽  
Enzyme Action ◽  
Linear Reaction ◽  
Simplified Procedure ◽  
Automated Determination

Abstract A new and simplified procedure for the automated determination of serum alkaline phosphatase uses the AutoAnalyzer. The substrate p-nitrophenylphosphate in 2-amino-2-methyl-1-propanol offers the prime advantage of providing directly its own chromogen, p-nitrophenol, following enzyme action. The procedure also permits use of small sample volumes, provides linear reaction rates, and has a simple manifold design. Correlations are presented between the manual procedure and the automated system.

Enzyme immunoassay of beta-hexosaminidase A and B in serum: carrier detection of GM2-gangliosidoses, and equivalence of enzyme activity and enzyme protein reactivity

1993 ◽  
Vol 39 (7) ◽  
pp. 1412-1415 ◽  
Author(s):  
A Isaksson ◽  
B Hultberg ◽  
P Masson ◽  
E Landels ◽  
A Fensom
Keyword(s):  
Enzyme Activity ◽  
Enzyme Immunoassay ◽  
Sandhoff Disease ◽  
Control Group ◽  
Enzyme Protein ◽  
Tay Sachs Disease ◽  
Hexosaminidase A ◽  
The Mean ◽  
Gm2 Gangliosidoses ◽  
Apparently Healthy

Abstract beta-Hexosaminidase (Hex; EC 3.2.1.52) isoenzymes A and B were analyzed in sera from a control group of 22 apparently healthy subjects, 13 obligate carriers of Tay-Sachs disease (TSD), 10 obligate carriers of Sandhoff disease (SHD), and 4 affected TSD patients by enzyme immunoassay methods based on enzyme activity. No Hex A activity was detected in the sera of patients with TSD. The activities of Hex A in the obligate carriers of TSD and SHD tended to be lower (nonsignificantly) than in the control group. Hex B activities tended to be higher in TSD patients as well as in carriers of TSD, although the mean activities did not significantly differ from the corresponding mean for the control group. However, Hex B activities were decreased in the carriers of SHD in comparison with the other groups. Sera from 900 postmenopausal women, all of age 55 years, were also analyzed for Hex isoenzymes; the results indicated a carrier frequency of about 1 in 200 for both TSD and SHD. We also compared the enzyme immunoassay method based on enzyme activity with one based on the antigenic (enzyme protein) reactivity alone. Because both methods yielded similar information, we conclude that no significant amounts of inactive enzyme protein are present in the circulation.

scholarly journals Late Onset Tay-Sachs Disease in a Non-Jewish Patient: Case Report

2017 ◽  
Vol 63 (4) ◽  
pp. 199-203 ◽  
Author(s):  
Smaranda Maier ◽  
Zoltan Bajko ◽  
Anca Moţăţăianu ◽  
Adina Stoian ◽  
Bianca Şchiopu ◽  
...  
Keyword(s):  
Late Onset ◽  
Muscular Atrophy ◽  
Cerebellar Atrophy ◽  
Lysosomal Storage ◽  
Tay Sachs Disease ◽  
Cerebral Mri ◽  
Extrapyramidal Syndromes ◽  
Hexosaminidase A ◽  
Uncommon Condition

AbstractTay-Sachs disease (TSD) is a rare, inherited, autosomal rececessive lysosomal storage disease. The late-onset form is an uncommon condition among non-Jewish population.We present the case of a 32 years old male patient without Jewish origins, in whom the disease began in adolescence and was initially diagnosed with spinal muscular atrophy. He developed progressively protean neurological symptomatology, including tetraparesis, cerebellar and extrapyramidal syndromes. The diagnosis was based on the cerebral MRI, showing severe cerebellar atrophy and the determination of the Hexosaminidase A activity, revealing low level.In patients showing signs of lower motor neuron involvement, cerebellar and pyramidal signs and marked cerebellar atrophy the late-onset TSD should be suspected, and the first step in establishing the diagnosis should be to determine the serum activity of Hexosaminidase A.

scholarly journals Determination of Glycosylated Haemoglobin in Normal, Newborn and Diabetic Saudi Arabs

1987 ◽  
Vol 24 (3) ◽  
pp. 279-282 ◽  
Author(s):  
A I Alayash ◽  
A Dafallah ◽  
H Al-Husayni ◽  
A K Al-Ali ◽  
A Al-Qourain ◽  
...  
Keyword(s):  
Thiobarbituric Acid ◽  
Mean Value ◽  
Glycosylated Haemoglobin ◽  
Diabetic Patients ◽  
Adult Males ◽  
Glycosylated Haemoglobin Level ◽  
Patients With Diabetes ◽  
The Mean ◽  
Normal Adults

Colorimetric determinations of glycosylated haemoglobin by the thiobarbituric acid method were carried out in normal adults ( n = 142), newly born infants of healthy mothers ( n = 81), and in a group of patients with diabetes mellitus ( n = 124). The glycosylated haemoglobin level in normal adult males was 4·9%, which is close to that reported for other populations. No correlation was found between age and the levels of glycosylated haemoglobin in males over 10 years old. However, the mean value for glycosylated haemoglobin in cord blood was 4·1%, significantly different from that of adults. The range values for glycosylated haemoglobin in diabetic patients was 7–19%. The mean value for glycosylated haemoglobin was 10·9%, similar to that established in other diabetic populations. Results of colorimetric determinations of glycosylated haemoglobin in the Saudi population compare well with other ethnic groups and, therefore, suggest no ethnic differences in glycosylated haemoglobin levels.

Relationships among Urinary Aminoimidazolecarboxamide in Urine and Folate, and Vitamin B12 Concentrations in Serum

1973 ◽  
Vol 19 (9) ◽  
pp. 1049-1052 ◽  
Author(s):  
J W Harrison ◽  
B A Slade ◽  
W Shaw
Keyword(s):  
Vitamin B12 ◽  
Serum Vitamin ◽  
Vitamin B12 Deficiency ◽  
Strong Relationship ◽  
Automated System ◽  
Serum Folate ◽  
B12 Deficiency ◽  
The Mean ◽  
Folate And Vitamin B12

Abstract Urinary aminoimidazolecarboxamide (AIC), serum folate, and serum vitamin B12 values were determined in 84 apparently healthy individuals. An automated system for determination of AIC in urine is described. Despite claims to the contrary, we found no evidence of a strong relationship between elevated (e.g., >1.3 µg/mg of creatinine) AIC excretion as reflected in a casual sample of urine and folate or vitamin B12 deficiency. Urinary AIC values ranged from 0.10 to 5.20 µg/mg of creatinine. The mean for the population examined was 1.36 ± 1.02 µg/mg of creatinine.

A modified radioimmunoassay for 1,25-dihydroxycholecalciferol.

1981 ◽  
Vol 27 (3) ◽  
pp. 458-463 ◽  
Author(s):  
T K Gray ◽  
T McAdoo ◽  
D Pool ◽  
G E Lester ◽  
M E Williams ◽  
...  
Keyword(s):  
Radioligand Binding ◽  
Normal Range ◽  
High Affinity ◽  
Organic Extraction ◽  
The Mean ◽  
The Stability ◽  
Mean Concentration ◽  
Chromatographic Isolation ◽  
Normal Adults

Abstract A radioimmunoassay for 1,25-dihydroxycholecalciferol which did not cross react with 1,25-dihydroxyergocalciferol is described. IgG fractions were prepared from the serum of rabbits that had been immunized with 1,25-dihydroxycholecalciferol-3-hemisuccinate coupled to bovine albumin. Radioligand binding by the IgG fractions was time-, temperature-, and pH-dependent. The IgG fractions had a high affinity for 1,25-dihydroxycholecalciferol but cross reacted with 25-hydroxycholecalciferol and 24,25-dihydroxycholecalciferol. Vitamin D2 metabolites did not cross react in the assay when amounts up to 9 ng per tube were tested. The determination of 1,25-dihydroxycholecalciferol in human serum required an organic extraction and chromatographic isolation of the metabolite. Radioligand binding was influenced by the presence and concentration of the proteins in the phosphate buffer. The mean concentration of 1,25-dihydroxycholecalciferol in serum from normal adults was 56 (SEM 5.7) ng/L. 1,25-Dihydroxycholecalciferol was not detectable in serum from a nephrectomized subject and the concentration in serum was lower than normal in hypoparathyroid patients. Ingestion of 1,25-dihydroxycholecalciferol by nephrectomized or hypoparathyroid patients restored the concentration of 1,25-dihydroxycholecalciferol in serum to the normal range. The stability of the IgG fraction, the relatively short incubation interval, and the ability to measure 1,25-dihydroxycholecalciferol without interference from 1,25-dihydroxyergocalciferol are unique aspects of this radioimmunoassay.

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