The Determination of Thiamine in Small Amounts of Whole Blood and Serum by a Simplified Thiochrome Method

1965 ◽  
Vol 11 (6) ◽  
pp. 617-623 ◽  
Author(s):  
Than Myint ◽  
Harold B Houser
Keyword(s):  
Whole Blood ◽  
Serum Concentrations ◽  
Serum Samples ◽  
Adsorption Column ◽  
The Mean ◽  
Mean Differences ◽  
Hydrolysis Of ◽  
Sample Dilution ◽  
Low Serum

Abstract This simplified thiochrome method for the determination of thiamine eliminates deproteinization, sample dilution (other than reagent), and purification by adsorption column; pH need not be adjusted as it is automatically controlled. The method depends upon the hydrolysis of whole blood and serum with N HCI, N/10 HCI, and diastase enzyme. Reproducibility was good; the mean differences (± S.D.) between duplicate blood and serum samples were 2.36 ± 2.87 and 1.5 ± 1.70 mµg./ml., respectively. Recovery of added thiamine ranged from 94 to 104% with a mean of 99.5 ± 3.41%. Storage of hydrolysates for 30 days did not change the results, and low serum concentrations could be measured in serum. Whole blood and serum values of thiamine in 44 healthy adults ranged from 11.3 to 47.8 mµg./ml. (mean, 29.3) and from trace amounts to 20.5 mµg./ml. (mean, 10.2), respectively.

scholarly journals Toxicokinetics and correlation of carbamazepine salivary and serum concentrations in acute poisonings

2012 ◽  
Vol 69 (5) ◽  
pp. 389-393 ◽  
Author(s):  
Snezana Djordjevic ◽  
Vesna Kilibarda ◽  
Slavica Vucinic ◽  
Tomislav Stojanovic ◽  
Biljana Antonijevic
Keyword(s):  
High Pressure ◽  
Body Fluid ◽  
Acute Poisoning ◽  
Serum Concentrations ◽  
Therapeutic Application ◽  
Serum Samples ◽  
Individual Variations ◽  
The Mean ◽  
Therapeutic Doses

Background/Aim. Saliva is a body fluid which, like serum, can be used for determination of concentrations of certain drugs, both in pharmacotherapy as well as in acute poisonings. The aim of this study was to determine carbamazepine concentrations in both saliva and serum in acute poisoning in order to show if there is a correlation between the obtained values, as well as to monitor toxicokinetics of carbamazepine in body fluides. Methods. Saliva and serum samples were obtained from 26 patients treated with carbamazepine and 20 patients acutely poisoned by the drug immediately after their admission in the Emergency Toxicology Unit. Determination of salivary and serum carbamazepine concentrations was performed by the validated high pressure liquid chromatographyultraviolet (HPLC-UV) method. Results. A significant correlation of salivary and serum carbamazepine concentrations in both therapeutic application and acute poisoning (r = 0.9481 and 0.9117, respectively) was confirmed. In acute poisonings the mean ratio between salivary and serum concentrations of carbamazepine (0.43) was similar to the mean ratio after its administration in therapeutic doses (0.39), but there were high inter-individual variations in carbamazepine concentrations in the acutely poisoned patients, as a consequence of different ingested doses of the drug. In acute poisoning the halftime of carbamazepine in saliva and serum was 12.57 h and 6.76 h, respectively. Conclusion. Our results suggest a possible use of saliva as an alternative biological material for determination of carbamazepine concentrations in therapeutic application and acute poisoning as well, and a possible extrapolation of the results obtained in saliva to serum concentrations of carbamazepine.

Autoantibodies to Thrombomodulin: Development of an Enzyme Immunoassay and a Survey of their Frequency in Patients with the Lupus Anticoagulant

1992 ◽  
Vol 67 (05) ◽  
pp. 507-509 ◽  
Author(s):  
John Gibson ◽  
Margaret Nelson ◽  
Ross Brown ◽  
Hatem Salem ◽  
Harry Kronenberg
Keyword(s):  
Enzyme Immunoassay ◽  
Lupus Anticoagulant ◽  
Specific Binding ◽  
Technical Problem ◽  
Serum Samples ◽  
Citrate Buffer ◽  
The Mean ◽  
Sample Dilution ◽  
Negative Population ◽  
Serum Components

SummaryIn order to investigate the possibility that autoantibodies to thrombomodulin (TM) may exist in patients with the lupus anticoagulant (LA) and perhaps be implicated in the pathogenesis of recurrent thrombosis seen in such patients, we developed an enzyme-immunoassay to screen serum samples for anti-human TM activity. The major technical problem encountered in developing this assay was to reduce the non-specific binding of serum components from both the LA positive and the negative population. Considerable reduction of non-specific binding was achieved by use of a phosphate/citrate buffer at pH 8.0 and the use of an optimal sample dilution of 1/40. In addition, samples were always tested in parallel in blank wells and results are expressed as an OD ratio. Samples from 113 patients with the LA were assayed and compared to 78 patients referred for LA testing but found to be negative. The mean OD values for the LA positive patients (± SD) was 1.36 (0.44) with a range of 0.78-2.57. This was virtually identical to the values for the LA negative population (1.38 ± 0.40, range 0.76-2.77). The results of this study indicate that there is no evidence for the presence of a significant autoantibody activity to TM in patients with the LA when compared to LA negative patients. If such autoantibodies do exist their frequency must be quite low.

LRF and TRF test during long-term danazol treatment: increase of the LH and FSH responses but decrease of the prolactin and TSH responses

1983 ◽  
Vol 104 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. Leppäluoto ◽  
L. Rönnberg ◽  
P. Ylöstalo
Keyword(s):  
Clinical Symptoms ◽  
Follicular Phase ◽  
Blood Samples ◽  
Hormone Levels ◽  
Coefficients Of Variation ◽  
The Mean ◽  
Thyroid Hormone Levels ◽  
Low Serum

Abstract. Seven patients suffering from severe endometriosis were treated with danazol 200 mg × 3 daily for 6 months. Clinical symptoms were alleviated and menses disappeared in response to the treatment. After cessation of the treatment the menstrual bleedings returned in 1–3 months. Blood samples for determination of gonadotrophins, prolactin (Prl), oestradiol (E2), progesterone, thyroid hormones and thyrotrophin in radioimmunoassays were taken and a combined TRF and LRF test carried out in the follicular phase before treatment, at the 6th month of treatment and after reappearance of the first menses. There were no statistically significant changes in the basal levels of serum FSH, LH or TSH during the danazol treatment. Neither was there any change in episodic secretions of FSH, LH or Prl, as determined by the mean coefficients of variation of the hormone levels in seven consecutive samples taken at 20 min intervals. On the other hand, serum E2, Prl and thyroid hormone levels were significantly decreased in the 6th month of treatment. In the TRF-LRF test the responses of serum FSH and LH were significantly higher and those of serum Prl and TSH significantly lower during danazol treatment than before. Prl responses remained lowered after the treatment. It appears that low serum oestrogen levels, induced by the danazol treatment, sensitize the pituitary gonadotrophs to exogenous LRF, but make the sensitivity of thyrotrophs and lactotrophs lower to exogenous TRF. These results thus indicate that danazol does not make the pituitary gonadotrophs insensitive to LRF, but danazol may rather inhibit the secretion of hypothalamic LRF.

A Versatile Radioimmunoassay for the Determination of Serum Oestriol in Pregnancy

1973 ◽  
Vol 10 (1-6) ◽  
pp. 159-166 ◽  
Author(s):  
J. E. H. Stafford
Keyword(s):  
Normal Pregnancy ◽  
Optimum Conditions ◽  
Random Series ◽  
The Mean ◽  
Hydrolysis Of ◽  
Selection Of ◽  
In Pregnancy

A versatile radioimmunoassay for serum oestriol in pregnancy has been developed which requires 10 μ| of serum (for total) or 50 μ| (for unconjugated). Selection of the optimum conditions for the hydrolysis of serum oestriol conjugates, the isolation of free oestriol, the displacement of tritiated oestriol by cold oestriol and the separation of the free and bound fractions is described. Total oestriol levels doubled between weeks 34 and 38 of normal pregnancy, very little change occurring in the mean level after the 38th week of gestation. In a random series of pregnancy sera there was a significant correlation between total and unconjugated oestriol.

scholarly journals A new approach to the assessment of marginal vitamin A deficiency in children in suburban Guwahati, India: hydrolysis of retinoyl glucuronide to retinoic acid

2008 ◽  
Vol 101 (6) ◽  
pp. 794-797 ◽  
Author(s):  
Pulin C. Sarma ◽  
Bhabesh C. Goswami ◽  
Krishna Gogoi ◽  
Harsha Bhattacharjee ◽  
Arun B. Barua
Keyword(s):  
Retinoic Acid ◽  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Serum Retinol ◽  
Serum Samples ◽  
Group I ◽  
High Prevalence ◽  
Hydrolysis Of ◽  
Β Carotene

The objective of the present study was to determine marginal vitamin A deficiency (VAD) by testing the hydrolysis of retinoyl glucuronide (RAG) to retinoic acid (RA) in children. Previous studies in rats showed that hydrolysis occurred when rats were vitamin A deficient. Children (n 61) aged 3–18 years, were divided into two groups, I and II. Blood was collected from the children in Group I (n 19) who were not dosed with RAG. Children in Group II (n 42) were administered all-trans retinoyl glucuronide (RAG) orally, and blood was collected 4 h after the dose. All serum samples were analysed for retinoids and carotenoids. RA was detected in serum only when serum retinol was < 0·85 μmol/l. Thus, hydrolysis of RAG to RA occurred in children with VAD or marginal VAD. Serum retinol was < 0·35 μmol/l in twenty-one children, 0·35–0·7 μmol/l in twenty-three children, 0·7–0·9 μmol/l in eleven children and >1 μmol/l in six children. Mean serum retinol in sixty-one children was 0·522 (sd 0·315) μmol/l. Mean β-carotene (0·016 (sd 0·015) μmol/l) was far below normal compared to the level of lutein (0·176 (sd 0·10) μmol/l) in sixty-one children. A low β-carotene level might be due to a low intake of carotene but high demand for vitamin A. The RAG hydrolysis test may prove to be a useful approach for the determination of marginal VAD with no clinical or subclinical signs of VAD. High prevalence of VAD amongst certain communities in Assam cannot be ruled out.

Immunoneutralization and immunocytochemical localization of inhibin α subunit during the mid-luteal phase in the stump-tailed macaque

1992 ◽  
Vol 133 (3) ◽  
pp. 341-NP ◽  
Author(s):  
H. M. Fraser ◽  
K. B. Smith ◽  
S. F. Lunn ◽  
G. M. Cowen ◽  
K. Morris ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Treatment Cycle ◽  
Serum Concentrations ◽  
Serum Samples ◽  
Α Subunit ◽  
Late Luteal Phase ◽  
Early Follicular Phase

ABSTRACT The putative endocrine role of inhibin in the control of FSH secretion during the luteal phase in the primate was investigated by immunoneutralization. Antisera against the 1–23 amino acid sequence of the N-terminus of the human inhibin α subunit were raised in a ewe and three macaques. Antisera (10–20 ml) were administered to macaques on day 8/9 of the luteal phase and serum samples collected during the treatment cycle and post-treatment cycle for determination of FSH, oestradiol and progesterone. In addition, localization of inhibin within the macaque ovary at this stage of the luteal phase was investigated using the ovine antiserum. Intense immunostaining was localized within the granulosa-lutein cells of the corpus luteum with absence of staining in the thecalutein cells or other ovarian compartments. Administration of antisera was without significant effect on serum concentrations of FSH when compared with control animals, either during the first 24 h of detailed observation or for the following 10-day period of the late luteal phase and subsequent early follicular phase. These results provide further evidence that the corpus luteum is the major source of inhibin immunoreactivity during the primate menstrual cycle, but fail to support an endocrine role for inhibin in the suppression of FSH secretion. Journal of Endocrinology (1992) 133, 341–347

scholarly journals Evaluation of three methods for hemoglobin measurement in a blood donor setting

1999 ◽  
Vol 117 (3) ◽  
pp. 108-112 ◽  
Author(s):  
Jacob Rosenblit ◽  
Cláudia Regina Abreu ◽  
Leonel Nulman Szterling ◽  
José Mauro Kutner ◽  
Nelson Hamerschlak ◽  
...  
Keyword(s):  
Albert Einstein ◽  
Photometric Method ◽  
Private Institution ◽  
Blood Samples ◽  
Photometric Detection ◽  
Coefficients Of Variation ◽  
The Mean ◽  
Mean Differences ◽  
Good Agreement

CONTEXT: The hemoglobin (Hb) level is the most-used parameter for screening blood donors for the presence of anemia, one of the most-used methods for measuring Hb levels is based on photometric detection of cyanmetahemoglobin, as an alternative to this technology, HemoCue has developed a photometric method based on the determination of azide metahemoglobin. OBJECTIVE: To evaluate the performance of three methods for hemoglobin (Hb) determination in a blood bank setting. DESIGN: Prospective study utilizing blood samples to compare methods for Hb determination. SETTING: Hemotherapy Service of the Hospital Israelita Albert Einstein, a private institution in the tertiary health care system. SAMPLE: Serial blood samples were collected from 259 individuals during the period from March to June 1996. MAIN MEASUREMENTS: Test performances and their comparisons were assessed by the analysis of coefficients of variation (CV), linear regression and mean differences. RESULTS: The CV for the three methods were: Coulter 0.68%, Cobas 0.82% and HemoCue 0.69%. There was no difference between the mean Hb determination for the three methods (p>0.05). The Coulter and Cobas methods showed the best agreement and the HemoCue method gave a lower Hb determination when compared to both the Coulter and Cobas methods. However, pairs of methods involving the HemoCue seem to have narrower limits of agreement (± 0.78 and ± 1.02) than the Coulter and Cobas combination (± 1.13). CONCLUSION: The three methods provide good agreement for hemoglobin determination.

scholarly journals Determination of serum triglycerides by an accurate enzymatic method not affected by free glycerol.

1985 ◽  
Vol 31 (7) ◽  
pp. 1227-1228 ◽  
Author(s):  
D R Sullivan ◽  
Z Kruijswijk ◽  
C E West ◽  
M Kohlmeier ◽  
M B Katan
Keyword(s):  
Free Glycerol ◽  
Glycerol Phosphate ◽  
Serum Samples ◽  
Serum Triglycerides ◽  
Target Values ◽  
The Mean ◽  
Aqueous Detergent ◽  
Subsequent Addition ◽  
Enzymatic Procedure

Abstract In this automated single-run enzymatic procedure for specific determination of triglycerides in serum, free glycerol is removed from the reaction mixture by pre-incubation with glycerol phosphate oxidase and peroxidase. The subsequent addition of lipase and the chromogen, 4-aminoantipyrine, results in the formation of color proportional to the amount of triglycerides in serum. Standards containing triolein in aqueous detergent are used to calibrate the method. For serum pools from the Centers for Disease Control with target values of 0.74, 1.41, and 2.63 mmol/L, the method produced biases of +0.01, -0.05, and 0.00 mmol/L, respectively (mean: -0.01 mmol/L or -0.4%). The mean coefficient of variation was 1.4% within and 2.5% between days; the combined CV, 2.9%. Ninety 6-microL serum samples can be analyzed per hour. The method is more accurate and precise than one based on an NADH-coupled enzyme system with separate addition of lipase.

scholarly journals Analytical evaluation of Kone Microlyte determination of ionized magnesium

1994 ◽  
Vol 40 (1) ◽  
pp. 52-55 ◽  
Author(s):  
H E van Ingen ◽  
H J Huijgen ◽  
W T Kok ◽  
G T Sanders
Keyword(s):  
Limit Of Detection ◽  
Analytical Evaluation ◽  
High Concentration ◽  
Serum Samples ◽  
Ionized Magnesium ◽  
Carrier Liquid ◽  
The Mean ◽  
High Concentration Range ◽  
Induced Changes

Abstract We performed an analytical evaluation of a commercially available instrument for determining ionized magnesium through use of a neutral carrier, liquid-membrane-based ion-selective electrode. Reproducibility (CV 2-4%), linearity (0.30-2.50 mmol/L), lower limit of detection (0.30 mmol/L), and absence of interference from Ca2+ indicate adequate performance for measuring ionized magnesium in plasma or serum samples in the normal to high-concentration range. Sodium in excess of 150 mmol/L caused a negative bias, which can be explained by ionic strength-induced changes in activity coefficients. The use of heparin as an anticoagulant must be restricted to concentrations &lt; 15 units/mL because of the binding of magnesium to heparin. The mean +/- SD concentration of ionized magnesium and its fraction of total magnesium in 76 healthy volunteers were 0.56 +/- 0.05 mmol/L and 0.65 +/- 0.04, respectively.

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