bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prenatal Screening for Inborn Errors of Metabolism
Authors: Ellis R. B. 
Published: February 2014

The problems likely to be encountered and the limitations of present methods of pre-natal diagnosis of inborn errors of metabolism by assay of the deficient enzyme activity is emphasised. Particular attention is given to the problems of testing the correct enzyme deficiency, choosing the most appropriate foetal sample, and of minimising the effects of maternal contamination. For those disorders which are recessively inherited, the feasibility of mass screening for the detection of marriages between carriers is considered as a means whereby all foetuses at risk for a given condition may be recognised.
Comparative Study of Thyroxine Assays Employing Kit Radio-Ligand Reagents
Authors: Watson D. , Lees S. 
Published: February 2014

A comparative study of some ‘kit’ radiometric procedures for the determination of thyroxine in serum is reported. Four manufacturers' competitive-binding reagents and methods—three incorporating prior extraction and one employing column elution—are examined. Considerable discrepancies exist between the manufacturers' ‘standards’ which, in the main, account for the differences in results obtained by the different methods. Other deficiencies include susceptibility to metal ion interference, variation (up to 8%) in thyroxine extraction and non-specific, i.e. ‘mimic T-4’, measurement. Radio-ligand reagent ‘kits’ need to be critically assessed before being used routinely. Separation of hypo-and hyperthyroid from euthyroid patients is achieved as well with some competitive protein-binding T-4 methods as with serum PBI.
Contamination from Syringes and Blood Container Pots in Trace Element Analysis
Authors: Taylor A. , Marks V. 
Published: February 2014

Syringes, blood container pots and test tubes have been investigated to determine whether they act as sources of contaminants during trace element analyses. Urine containers were investigated to decide which materials do not absorb mercury from dilute solutions. No copper and little magnesium contamination was found. Zinc contamination was unpredictable. Very large amounts of zinc leached from the rubber end cap of the piston of disposable, plastic sterile syringes. The B.S.I. Standards for disposable syringes were shown to be unacceptable for heavy metals.
Steroid Excretion by an Infant with an Unusual Salt-Losing Syndrome: A Gas Chromatographic–Mass Spectrometric Study
Authors: Shackleton C. H. L. , Snodgrass G. H. A. I. 
Published: February 2014

The excretion of steroids by an infant with pseudohypoaldosteronism is reported. The patient presented with symptoms of hyperkalaemia and hyponatraemia, and was maintained for a period on a high salt intake and mineralocorticoids. However, he collapsed on the 48th day of life and could not be resuscitated. The urinary steroids were identified by combined gas chromatography–mass spectrometry and quantitation was achieved by gas chromatography. The following steroids were identified: tetrahydroaldosterone, tetrahydrocortisone, α- and β-cortolone, 1 β-hydroxytetrahydrocortisone, 1 β-hydroxycortolone, tetrahydrocorticosterone (THB), tetrahydro-11-dehydrocorticosterone (THA), 3α, 20α, 21-trihydroxy-5β-pregnan-ll-one, 5-pregnene-3β, 16α, 20α, 21-tetrol, and 5-androstene-3β, 16αa, 17β-tiiol. The patient evidently secreted an excess of aldosterone so the disorder was probably due to a form of renal-tubule unresponsiveness to this hormone. Some of the urinary steroids normally excreted in large amounts during infancy (16α-hydroxy DHA, 16-oxo-androstenediol, and 16α-hydroxypregnenolone) were not detected in the urine samples, and it is suggested that the precursor of these steroids (pregnenolone) was being fully utilised in the synthesis of aldosterone and cortisol.
A Comparative Study of Manual Methods for Serum Triglyceride Estimation
Authors: Goldfinhc M. E. , Prudhoe K. 
Published: February 2014

A comparison is made of the accuracy, precision, and convenience of two manual serum triglyceride methodologies based on solid phase adsorption and liquid phase partition procedures. Both methods are accurate but the precision and convenience of the latter is far superior. The use of home made reagents reduces the cost of both substantially below that of any commercial alternative, including the popular enzymatic methods.
An Evaluation of the Greiner Selective Analyzer and its Role in the Clinical Laboratory
Authors: Skinner Andrew G. , Wilding Peter 
Published: February 2014

The Greiner Selective Analyzer (GSA II) was evaluated over a period of six months. The evaluation assessed the reliability, accuracy, and precision of the analyser for six determinations. The methods evaluated were for glucose, urea, creatinine, total protein, total bilirubin, and alkaline phosphatase. Comparison of results was also made with those obtained for the same specimens using the Technicon SMA 12/60 Analyzer. Correlation and comparison of results indicate that the Greiner Selective Analyzer performed better for three of the methods but worse for serum creatinine determination. The role of the analyser as a routine tool in the clinical laboratory was also evaluated during analyses of approximately 900 patient specimens. Other features evaluated were analytical range of the six methods under study, the economics of operation, temperature control, and electrical and mechanical safety.
Hypocalcaemia: Differential Diagnosis and Investigation
Authors: Paterson C. R. 
Published: February 2014

Hypocalcaemia accounts for many of the telephone inquiries made to the Department of Biochemical Medicine in Dundee. About half of these cases can be explained by hypoalbuminaemia; the causes of “true” hypocalcaemia are given in Table 1. Chronic renal failure is probably the most frequent cause of hypocalcaemia in Britain. In the world as a whole it is likely that vitamin D deficiency, causing rickets in children and osteomalacia in adults, is the commonest cause of hypocalcaemia.
Different Phenotypes for Phenylalanine Hydroxylase Deficiency
Authors: Güttler F. , Hansen G. 
Published: February 2014

Abnormalities related to the hydroxylation of phenylalanine to tyrosine are classified into three phenotypes based on the amount of dietary phenylalanine tolerated to keep serum phenylalanine within therapeutic levels, i.e., 180–425 μmol/l (3–7 mg/100 ml): (1) Classical phenylketonuria (PKU) tolerating approximately 17% of a normal intake of phenylalanine or approximately 0.12 mmol per kg body weight; (2) mild PKU with a tolerance some 50% higher; and (3) persistent hyperphenylalaninaemia (HPA) with serum phenylalanine values within therapeutic levels on a daily intake of geqslant 0.7 mmol phenylalanine per kg body weight. Oral phenylalanine loading was performed on 100 heterozygotes for these abnormalities and 33 normal homozygotes. The slope of the rise in serum tyrosine multiplied by the maximum serum tyrosine concentration over the maximum phenylalanine concentration was the most powerful discriminant (D/_s, 3.54; overlapping 2.4%). Three heterozygous phenotypes were distinguished by this discriminant, and a significant correlation was observed between the phenotypic combination of the parents and the phenotype of their affected child. In particular, parents of children with classical PKU were clearly distinguished from heterozygotes for the other two abnormalities.
An Investigation into the Immunochemical Properties of the Isoenzymes of Human Alkaline Phosphatase
Authors: Abdullah J. Sh. , Gowland E. 
Published: February 2014

A study was carried out to investigate the immunochemical properties of the alkaline phosphatases present in liver, placenta, intestine, and kidney. Butanol extracts of the tissues were examined by antigen-antibody crossed electrophoresis, and the immunoprecipitates formed by the enzymes were identified by use of a specific stain for alkaline phosphatase. The results obtained revealed three immuno-chemical types of alkaline phosphatase, designated L, P, and PI respectively. The distribution of these enzymes among the tissues examined was as follows: type L was the only enzyme detected in liver extract and type P the only one detected in placental extract. The extracts of intestine and kidney both contained two isoenzymes, one of which was type L and the other type PI.
Determination of Caffeine, Theophylline and Theobromine in Serum and Saliva Using High-Performance Liquid Chromatography
Authors: Scott N R , Chakraborty J , Marks V 
Published: February 2014

A method is described for the measurement of theobromine, theophylline and caffeine in serum and saliva by high-performance liquid chromatography (HPLC). A chloroform/isopropanol extract (85:15, v/v) is evaporated to dryness and chromatographed on a 100 times 4·5 mm id Hypersil octadecylsilane column with UV detection at 280 nm. Theobromine, theophylline, caffeine and the internal standard proxyphylline are satisfactorily resolved with an elution system of acetonitrile/tetrahydrofuran/50 mm acetate buffer, pH 4·0, (4:1:95, v/v). No interference is observed from the presence of xanthine metabolites or any of a number of common drugs examined. A good correlation was observed between the concentrations of caffeine in serum and in saliva suggesting that salivary measurements may be useful for the study of caffeine pharmacokinetics in man. Caffeine levels determined by the HPLC procedure described here agreed well with those obtained by a radioimmunoassay method. The method is also suitable for determining the xanthine content of beverages by direct injection of diluted samples.
Changes in Serum Ferritin and other ‘Acute Phase’ Proteins following Major Surgery
Authors: Rubin Caroline , Wood P J , Archer T , Rowe D J F 
Published: February 2014

We have measured ferritin concentrations in healthy women, and ferritin, C-reactive protein, iron and total iron-binding capacity in patients undergoing hysterectomy or major gastrointestinal surgery. Pre-operative serum ferritin concentrations in patients awaiting hysterectomy were significantly lower than those for patients awaiting gastrointestinal surgery and also lower than those for healthy women of similar age. Healthy women aged between 51 and 60 years had significantly higher ferritin levels than women aged 35–50 years. All patients studied showed large increases in serum ferritin and C-reactive protein concentrations after surgery and approximately similar decreases in iron and in total iron-binding capacity.
Circannual and Within-Individual Variation of Thyroid Function Tests in Normal Subjects
Authors: Harrop J S , Ashwell K , Hopton M R 
Published: February 2014

Blood was taken from normal subjects at monthly intervals over a period of one year for subsequent determination of serum thyroid hormone concentrations. Thyroid-stimulating hormone (TSH) responses to TSH-releasing hormone were performed at 3-monthly intervals. This study provided data on within-individual variation and on seasonally-related changes of these thyroid function tests. The results showed that, within an individual, thyroid hormone concentrations are maintained within narrow limits. For both thyroxine and triiodothyronine the component contribution of within-individual variation to the population-based variation (the latter also termed the ‘reference interval’, or colloquially the ‘normal range’) was small. This high degree of individuality implies that rigorous comparison of thyroid hormone results against a population-based ‘normal range’ can be potentially misleading. Despite the limited within-individual variation, seasonally-related changes in thryoid hormone concentrations were apparent, with higher thyroxine and triiodothyronine values seen in winter months. A tendency to a greater TSH response to TSH-releasing hormone was also noted at this time. Conceivably these changes could reflect a centrally-mediated response of the hypothalamic—pituitary—thyroid axis to environmental temperature.
Isotope Dilution Analysis Using Chromatographic Separation of Isotopic Forms of the Compound to be Measured
Authors: Pratt J J 
Published: February 2014

Using progesterone, testosterone, androstenedione, 11-oxoprogesterone and 11β-hydroxyprogesterone as models, a new form of isotope dilution assay has been developed. A known mass of deuterium-labelled steroid is added to the serum sample. High-performance liquid chromatography is used to separate endogenous steroid from its deuterium-labelled form. After separation, the two forms of the analyte are quantitated using conventional methods: radioimmunoassay, enzyme-linked immunoassay and, where the concentrations are high enough, ultraviolet light absorption. The ratio of the amounts of the two forms of the analyte is used to calculate the amount of unlabelled material in the original sample. The assay principle is quite general. A variety of high resolution methods are available to separate isotopic analogues of the same compound. A number of detection methods can be used to quantitate the separated isotopic forms. Extension of this principle to other fields of interest in bio-medicine is discussed briefly.
Performance and Clinical Utility of a Commercially Available ‘C-terminal’ PTH Assay
Authors: Ingle A R , Bailey J E , Matthews H L , Harrop J S 
Published: February 2014

The performance and clinical utility of a ‘C-terminal’ parathyroid hormone (PTH) radioimmunoassay (Dac-Cel, Wellcome Diagnostics) is described. Parathyroid hormone, as measured by the Dac-Cel method, is stable in whole blood samples for at least 24 h. 84% of patients with hypercalcaemia due to primary hyperparathyroidism have values above the upper limit seen in normocalcaemic subjects (0·5 μg/L), with detectable serum PTH demonstrable in the remaining 16%. In patients with hypocalcaemia due to hypoparathyroidism serum PTH was undetectable in 73% and ‘inappropriately’ low in the remainder. In 50% of patients with malignancy-associated hypercalcaemia serum PTH was undetectable, but was above 0·5 μg/L in 13%. Increased PTH concentrations were invariably found in patients with renal failure. The Dac-Cel method is a reliable and robust technique for measurement of PTH and in conjunction with determination of calcium facilitates the diagnosis of primary parathyroid disorders. Caution is required in the interpretation of PTH measurements in patients with renal failure; the significance of detectable PTH in some patients with malignancy-associated hypercalcaemia is not clear.
Does the Measurement of Serum Fructosamine Accurately Reflect Levels of Glycated Albumin in Insulin-Dependent Diabetes?
Authors: Winocour P H , Bhatnagar D , Reed P , Dhar H 
Published: February 2014

We have measured serum glycated albumin (GSA) by affinity chromatography and immunoturbidimetry, and serum fructosamine using a Cobas FARA analyser in blood samples from 37 type I diabetics and 21 healthy controls. Random blood glucose and glycated haemoglobin levels were also measured. Glycated haemoglobin (HbA1) correlated with glycated albumin and fructosamine in the diabetic group. A less clear relationship was found between glycated albumin and fructosamine. HbA1, GSA and fructosamine correlated poorly with random blood glucose levels. These data indicate that serum fructosamine levels do not accurately reflect those of glycated albumin, as has recently been suggested, in type I insulin-dependent diabetics where glycaemic control fluctuates more than in type II diabetics. It is postulated that the two methods reflect varying glycaemic levels to a different degree, thereby accounting for the disparity.
Short-Term Effect of a 75 g Oral Glucose Load on Glycohaemoglobin Levels
Authors: Forrest Richard D , Jackson Caroline A , Gould Barry J , Casburn-Budd Marianne , Taylor Julie E , Yudkin John S 
Published: February 2014

Two hundred and twenty-three subjects out of a total of 347 with various degrees of glucose tolerance were recalled after a screening survey for diabetes. They were a randomly selected sample of people over the age of 40 and they underwent a formal 75 g glucose tolerance test in order to assess the effect of a glucose load on glycohaemoglobin levels measured by four different assay methods. Oral glucose loading was found to affect glycohaemoglobin levels only when these were measured by an agar-gel electrophoretic method that did not remove the labile aldimine-linked Schiff base fraction. The increase in glycohaemoglobin during the glucose tolerance test as estimated by this method was proportional to the 2 h blood glucose level. Glycohaemoglobin levels measured by agar-gel electrophoresis with elimination of the Schiff base, by affinity chromatography and by iso-electric focussing, were not affected by a 75 g oral glucose load. We conclude that blood samples for glycohaemoglobin assay may be collected at any time of the day, without regard to the subject's previous food intake, provided an assay method is used that removed the aldimine-linked labile fraction.
HbA1 in the Diagnosis of Factitious Remission of Diabetes
Authors: Krentz A J , Hale P J , Albutt E C , Nattrass M 
Published: February 2014

A case of factitious remission of type I diabetes in an adolescent girl is reported. The clue to diagnosis came from an inconsistency between clinic blood glucose levels and the corresponding values of glycosylated haemoglobin. Investigations of 24 h hormone and metabolite profiles demonstrated discrepancies between insulin dose, endogenous insulin production and free insulin levels which provided confirmatory evidence of surreptitious self-administration of insulin by the patient.
The Relationship between Theophylline, Caffeine and Heart Rate in Neonates
Authors: Nadkarni S , Hay A W M , Faye S , Congdon P J 
Published: February 2014

Plasma theophylline and caffeine levels were measured in neonates receiving aminophylline for apnoea. Significant levels of caffeine were present in neonates with high plasma theophylline levels and particularly in those children who had been on theophylline for 6 days, or more. Caffeine levels in plasma decreased slowly compared to theophylline. Tachycardia did not occur in any infants even at theophylline values greater than 20 mg/L. For theophylline concentrations above 10 mg/L there was no relationship between heart rate and drug level. Heart rate alone cannot be used to predict toxic drug levels, and high drug levels will not necessarily cause tachycardia.
Erythrocyte and Plasma Magnesium Status in Nigerians with Diabetes Mellitus
Authors: Olukoga A O , Erasmus R T , Adewoye H O 
Published: February 2014

Erythrocyte and fasting plasma magnesium were assayed by a dyebinding colorimetric method using the metallochromic dye, Calmagite, in 51 diabetic Nigerians and 25 controls. Erythrocyte magnesium concentrations were similar in the diabetics and the controls. Fasting plasma magnesium concentrations were significantly lower only in insulin-treated diabetics as compared to controls. No significant correlations were observed between fasting plasma glucose concentrations and either plasma or erythrocyte magnesium concentrations in the diabetic groups. Also, no significant correlation was found between erythrocyte magnesium and plasma magnesium concentrations. However, erythrocyte magnesium concentrations were directly related to age while plasma magnesium concentrations were directly related to duration of diabetes in all diabetics. Erythrocyte and plasma magnesium concentrations were not significantly affected by sex and degree of plasma glucose control. These results suggest that insulin-treated black African diabetics may develop hypomagnesaemia which is not associated with depletion of the erythrocyte content of magnesium.
Effect of Body Mass and other Factors on Serum Liver Enzyme Levels in Men Attending for Well Population Screening
Authors: Robinson D , Whitehead T P 
Published: February 2014

Alcohol abuse is usually regarded as the most likely cause of elevated serum liver enzyme values in those attending for well population screening, but we have found increased body weight to be an important contributing factor. We have measured serum levels of alanine amino-transferase (ALT), aspartate aminotransferase (AST) and γ-glutamyl transferase (GGT) in approximately 21 000 men attending for routine health screening, and related these to behavioural factors such as alcohol consumption, cigarette smoking, exercise level and obesity. The levels of all three enzymes were positively correlated with levels of alcohol consumption. Decreasing levels of physical activity were associated with increases in mean ALT and GGT levels. Cigarette smoking showed only a weak effect on ALT and AST, which became non-significant after multivariate statistical analysis, but increasing consumption of cigarettes was associated with increased mean levels of GGT. In contrast, all three enzymes showed marked increases in mean levels with increasing body mass index (BMI). The effect of obesity was particularly important in the case of ALT: the prevalence of increased ALT values in obese subjects (BMI ≥ 31 kg/m2) was more than eight times that in those with normal weight (BMI ≤ 25 kg/m2), even after allowing for the confounding effect of alcohol consumption. This study is concerned solely with male subjects, but we hope to extend the analysis to females in the near future.
A Capillary Column Gas-Chromatographic Method for the Identification of Drugs of Abuse in Urine Samples
Authors: Caldwell R , Challenger H 
Published: February 2014

This paper describes the application of capillary column gas liquid chromatography (GLC) to the analysis of urine samples for drugs of abuse. A simple basic extraction into butylacetate is followed by temperature programmed analysis from 90°C to 310°C to provide a comprehensive screen for basic drugs, Retention data are presented for approximately 300 compounds. The use of capillary column GLC is compared with packed column methods used previously in this laboratory. The reproducibility of retention data and sensitivity of this analysis for several commonly encountered drugs are presented.
Distribution of Haemoglobin in Patients Presenting to Their General Practitioner, and its Correlation with Serum Ferritin
Authors: Challand G S , Michaeloudis Androulla , Watfa Rodeina R , Coles S J , Macklin J L 
Published: February 2014

We have conducted a survey in the United Kingdom in order to evaluate the prevalence of anaemia and of iron deficiency in elderly male and female patients and in female patients of child-bearing age presenting to their general practitioner. Although haemoglobin values were approximately normally distributed, there was evidence of a bimodal distribution of serum ferritin values, particularly in elderly men. A correlation between serum ferritin and haemoglobin values was found to exist, both in the elderly and in younger women. The overall prevalence of anaemia in the study population was 14·3%, although it was higher for elderly men (20·1%) than either elderly women (13·7%) or women of child-bearing age (11·9%). Iron deficiency associated with anaemia was more common in elderly men (45·2% of those anaemic) than elderly women (28·6%) or women of child-bearing age (25·6%). This survey indicates that the prevalence of anaemia among certain groups of high risk patients presenting for consultation to their general practitioner is about 1 in 7, although the prevalence is as high as 1 in 5 in elderly men.