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1.
Environ Res ; 133: 388-95, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24948546

ABSTRACT

Several polycyclic aromatic hydrocarbons (PAHs) are known or probable human carcinogens. We evaluated the relationship between PAH exposure and risk of childhood acute lymphoblastic leukemia (ALL) using concentrations in residential dust as an exposure indicator. We conducted a population-based case-control study (251 ALL cases, 306 birth-certificate controls) in Northern and Central California from 2001 to 2007. We collected residential dust using a high volume small surface sampler (HVS3) (n=185 cases, 212 controls) or by sampling from participants' household vacuum cleaners (n=66 cases, 94 controls). We evaluated log-transformed concentrations of 9 individual PAHs, the summed PAHs, and the summed PAHs weighted by their carcinogenic potency (the toxic equivalence). We calculated odds ratios (ORs) and 95% confidence intervals (CI) using logistic regression adjusting for demographic characteristics and duration between diagnosis/reference date and dust collection. Among participants with HVS3 dust, risk of ALL was not associated with increasing concentration of any PAHs based on OR perln(ng/g). Among participants with vacuum dust, we observed positive associations between ALL risk and increasing concentrations of benzo[a]pyrene (OR perln[ng/g]=1.42, 95% CI=0.95, 2.12), dibenzo[a,h]anthracene (OR=1.98, 95% CI=1.11, 3.55), benzo[k]fluoranthene (OR=1.71, 95% CI=0.91, 3.22), indeno[1,2,3-cd]pyrene (OR=1.81, 95% CI=1.04, 3.16), and the toxic equivalence (OR=2.35, 95% CI=1.18, 4.69). The increased ALL risk among participants with vacuum dust suggests that PAH exposure may increase the risk of childhood ALL; however, reasons for the different results based on HVS3 dust samples deserve further study.


Subject(s)
Dust/analysis , Polycyclic Aromatic Hydrocarbons/poisoning , Precursor Cell Lymphoblastic Leukemia-Lymphoma/chemically induced , California/epidemiology , Case-Control Studies , Child , Child, Preschool , Female , Housing , Humans , Infant , Male , Polycyclic Aromatic Hydrocarbons/analysis , Precursor Cell Lymphoblastic Leukemia-Lymphoma/epidemiology
3.
Ann Clin Biochem ; 34 ( Pt 4): 412-21, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9247675

ABSTRACT

This paper reports the development of an enhanced chemiluminescent (ECL) assay for measuring the total antioxidant (AO) capacity of serum, saliva and a fluid collectable from the gum margin called gingival crevicular fluid (GCF). The theory behind the assay is explained, and the optimum conditions for the assay, and for storage of reagents and clinical samples is described. Calibration lines were linear (R > or = 0.99; P < 0.0001) and the within batch coefficient of variations for a water soluble vitamin E analogue (Trolox), serum and saliva samples were < 5%. In saliva and GCF, a characteristic AO response not seen in serum of the same patients, was identified. Total peripheral (serum) and local (saliva) AO capacities (mumol/L Trolox) were investigated in patients with (n = 18) and without (n = 16) adult periodontitis. Serum AO status did not differ between groups. Salivary total AO concentrations were lower in the peridontitis (P) group [175 (53) mumol/L] than in the non-periodontitis (NP) group [254 (110) mumol/L1: P < 0.01], as were saliva:serum AO ratio's [0.37 (0.11) versus 0.5 (0.18): P < 0.01]. Periodontitis patients may have a reduced salivary AO concentration, which could result from, or predispose to, the damaging effects of reactive oxygen species (ROS). The potential for ROS production in the oral and periodontal environment may explain the presence of a specific antioxidant in oral fluids that is not detectable in serum. The ECL assay described provides a rapid, simple and reproducible method of measuring total antioxidant defence in small volumes of biological fluids.


Subject(s)
Antioxidants/analysis , Blood Chemical Analysis , Gingival Crevicular Fluid/chemistry , Luminescent Measurements , Periodontitis/metabolism , Saliva/chemistry , Adult , Calibration , Chromans/analysis , Cryopreservation , Female , Horseradish Peroxidase/metabolism , Humans , Kinetics , Male , Reactive Oxygen Species/metabolism , Vitamin E/analysis
4.
Ann Clin Biochem ; 33 ( Pt 6): 530-5, 1996 Nov.
Article in English | MEDLINE | ID: mdl-8937584

ABSTRACT

The separate and joint effects of cigarette smoking and alcohol consumption on serum activities of the enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) were investigated in 46,775 men attending the BUPA Health Screening Centre in London during the period 1983-1987, after allowing for differences in age, body mass index and exercise level. As expected, all showed a significant positive correlation with alcohol consumption. Cigarette smoking produced a significant increase in GGT activity in all drinking categories bar teetotallers, particularly for those smoking more than 20 cigarettes per day. There were no changes of clinical significance in AST or ALT activities with smoking. We postulate that the combined effects of alcohol and smoking on GGT activity are a result of induction of the enzyme by both alcohol and nicotine. Smoking as well as drinking habits should be taken into account when assessing the significance of an individual's enzyme activities.


Subject(s)
Alanine Transaminase/blood , Alcohol Drinking , Aspartate Aminotransferases/blood , Liver/enzymology , Smoking , gamma-Glutamyltransferase/blood , Adult , Age Factors , Body Mass Index , Humans , Male , Middle Aged
5.
Ann Clin Biochem ; 33 ( Pt 2): 99-106, 1996 Mar.
Article in English | MEDLINE | ID: mdl-8729716

ABSTRACT

The separate and joint effects of cigarette smoking and alcohol consumption on serum concentrations of total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglycerides were investigated in 46 750 men attending the BUPA Health Screening Centre in London during the period 1983-1987, after allowing for differences in age, body mass index and exercise level. Drinking alcohol was found to raise both total cholesterol and HDL-C concentrations, in such a way that HDL-C as a percentage of total cholesterol increased with increasing alcohol consumption. LDL-C concentrations increased with increasing alcohol consumption in non-smokers, but decreased in those smoking over 10 cigarettes per day. Drinking had no significant effect on triglycerides except at high levels of consumption. Smoking raised total cholesterol, LDL-C and triglycerides, but lowered HDL-C concentrations. In particular, smoking even small amounts could negate any protective benefit in HDL-C concentrations gained from moderate consumption of alcohol. Assuming a desirable lipid profile to consist of low total cholesterol, LDL-C and triglycerides and a high HDL-C value, this is best achieved for men by being a non-smoking moderate drinker.


Subject(s)
Alcohol Drinking/blood , Lipids/blood , Smoking/blood , Adult , Age Distribution , Body Mass Index , Cholesterol/blood , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Dose-Response Relationship, Drug , Humans , Male , Mass Screening , Middle Aged , Triglycerides/blood
6.
Clin Lab Haematol ; 17(2): 131-8, 1995 Jun.
Article in English | MEDLINE | ID: mdl-8536415

ABSTRACT

The objective of this study was to quantify the combined dose related effects of cigarette smoking and alcohol consumption on blood haemoglobin concentration, erythrocytes and leucocytes. The subjects consisted of 17,670 males attending for routine health screening, with an average age of 43 years and a range of 16-91 years. The number of cigarettes smoked each day was divided into six categories, and declared alcohol consumption into seven. Of the 42 different combinations of smoking and drinking groups, five were not reported because they contained less than 30 subjects. Haemoglobin concentration was significantly increased in those smoking more than 10 cigarettes per day. Smoking also increased the PCV. Alcohol had no effect on Hb or PCV. The red cell count was reduced by alcohol consumption, with even the lowest consumption producing a significant decrease. Both smoking and drinking raised the MCV in a linear dose relationship. The marked increase in white cell count with smoking was seen even in subjects smoking 10 cigarettes per day or less. It is suggested that social habits such as smoking and drinking should be considered when interpreting blood haematology values. Changes in haematology results could be used to encourage a healthier lifestyle.


Subject(s)
Alcohol Drinking/adverse effects , Erythrocytes/drug effects , Hemoglobins/analysis , Leukocytes/drug effects , Smoking/adverse effects , Adolescent , Adult , Aged , Aged, 80 and over , Dose-Response Relationship, Drug , Erythrocyte Count , Erythrocytes/pathology , Humans , Leukocyte Count , Leukocytes/pathology , Male , Middle Aged
7.
Clin Chem ; 41(1): 32-5, 1995 Jan.
Article in English | MEDLINE | ID: mdl-7813078

ABSTRACT

Aerobic metabolism in biological systems produces reactive oxygen species, and defense against such prooxidants requires antioxidant activity, e.g., predominantly vitamins C and E in serum. Recently, flavonoids (polyphenols occurring widely in plants) have been investigated in vitro for their antioxidant activity; whether they are absorbed after ingestion is not clear. Using a chemiluminescent assay of serum antioxidant capacity (SAOC), we have studied the effects in normal individuals of ingesting red wine, white wine, and high doses of vitamin C. In nine subjects who ingested 300 mL of red wine, the mean SAOC was increased by 18% after 1 h and by 11% at 2 h. The same amount of white wine produced 4% and 7% increases, respectively. The ingestion of 1000 mg (5.7 mmol) of ascorbic acid by four subjects increased their mean SAOC by 22% at 1 h and by 29% at 2 h. An in vitro comparison of red wine, white wine, and various fruit juices showed the high antioxidant capacity of red wine in addition to its ability to increase the antioxidant capacity of serum in vivo. The antioxidant effects of various flavonoids and other polyphenols were also studied.


Subject(s)
Antioxidants , Wine , Adult , Antioxidants/pharmacology , Ascorbic Acid/blood , Ascorbic Acid/pharmacology , Beverages , Female , Flavonoids/pharmacology , Fruit , Humans , Luminescent Measurements , Male , Middle Aged , Phenols/pharmacology , Polymers/pharmacology , Vitamin E/blood
8.
Ann Clin Biochem ; 29 ( Pt 2): 159-61, 1992 Mar.
Article in English | MEDLINE | ID: mdl-1626918

ABSTRACT

We have studied the relationship between serum glucose and urate in 260,699 men and 214,118 women from Sweden, and 140,084 men and 30,653 women from the UK. We found an increase in mean serum urate with increasing glucose concentrations up to 7.0 mmol/L in men and 9.0 mmol/L in women. Thereafter increasing glucose values were accompanied by a statistically significant decrease in urate concentrations. This fall was particularly marked in younger subjects. We believe this may have important implications for the free radical status of diabetics.


Subject(s)
Blood Glucose/analysis , Diabetes Mellitus/blood , Uric Acid/blood , Adult , England , Female , Humans , Male , Middle Aged , Sweden
9.
Clin Chem ; 37(6): 879-81, 1991 Jun.
Article in English | MEDLINE | ID: mdl-2049853

ABSTRACT

Certain diagnostic kits that measure serum urate by the Barham and Trinder principle of enzymic liberation of oxygen and its combination with chromogens can give results for urate in fresh serum that are approximately 20% lower than results from serum stored at ambient temperature for 72 h. In fresh serum, antioxidants compete with chromogen for liberated peroxyl-oxygen. We postulate that during storage the interfering antioxidant substances are destroyed. In some diagnostic kits, L-ascorbate oxidase is added to the reaction, eliminating some but not all of this effect. We discuss defects of several commercially available kits for determination of serum urate and recommend comparing results of these kits with results from the phosphotungstic acid method as a precaution against falsely low results.


Subject(s)
Reagent Kits, Diagnostic , Uric Acid/blood , Blood Preservation , Equipment Failure , Humans
10.
Ann Clin Biochem ; 26 ( Pt 5): 393-400, 1989 Sep.
Article in English | MEDLINE | ID: mdl-2573311

ABSTRACT

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 gamma-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 greater than or equal to 31 kg/m2) was more than eight times that in those with normal weight (BMI less than or equal to 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.


Subject(s)
Alanine Transaminase/blood , Aspartate Aminotransferases/blood , Body Mass Index , Mass Screening , gamma-Glutamyltransferase/blood , Adult , Aged , Alcohol Drinking/physiology , Exercise/physiology , Humans , Male , Middle Aged , Obesity/enzymology , Reference Values , Smoking/blood
11.
Ann Clin Biochem ; 25 ( Pt 5): 560-8, 1988 Sep.
Article in English | MEDLINE | ID: mdl-3232958

ABSTRACT

The establishment and first 7 years' operation of an external quality assessment scheme for clinical chemistry in the Middle East region are described. The scheme utilises specimens distributed previously in the UK, and the performance of participating laboratories is assessed relative to the UK consensus values, taking account of method. Variance Index scoring has been used to quantitate performance, and there has been an improvement in average scores during the operation of the scheme. There are currently 88 participants, though some laboratories which failed to return results regularly were removed from the scheme. The consensus values from the scheme itself have now been validated, and in future the scheme should operate independently.


Subject(s)
Chemistry, Clinical , Laboratories/standards , Blood Chemical Analysis/methods , Humans , Middle East , Quality Control , Saudi Arabia , United Kingdom
12.
Clin Sci (Lond) ; 72(1): 95-102, 1987 Jan.
Article in English | MEDLINE | ID: mdl-3802726

ABSTRACT

An epidemiological study was conducted in the market town of March, Cambridgeshire, to assess the quantitative importance of cooking and table salt to total dietary salt intake by the use of a fused mixture of lithium carbonate and sodium chloride. Men and women aged 20-60 participated in a 12 day study with sequential 24 h urine collections to assess salt sources over a 7 day period. Total salt consumption estimated from urinary chloride excretion amounted to 10.6 +/- 0.55 (SEM) g in 33 men and 7.4 +/- 0.29 (SEM) g in 50 women. The cooking salt eaten was only 0.45 +/- 0.09 (SEM) g in men and women, with men eating more table salt (0.77 g/day) than women (0.46 g/day). Discretionary sources, i.e. cooking and table salt use, contributed only 15% to the total intake. Salt from manufacturing foods and catering in purchased food therefore provided on average 85% of total salt intake. These results are consistent even when an allowance is made for the slightly poorer pouring quality of the lithium-tagged salt. The importance of food as a source of salt was reflected in the significant relationship between the weight of the individual and the amount of salt eaten (for males P less than 0.05 and for females P less than 0.001). Cooking salt consumption did not relate to the amount of salt derived from purchased food nor did table salt use relate to the amount of salt in cooked foods.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Diet , Sodium Chloride/analysis , Adult , Anthropometry , Body Weight , Chlorides/urine , Creatinine/urine , England , Feeding Behavior , Female , Humans , Lithium/urine , Male , Marriage , Middle Aged , Sodium/urine
13.
J Pharm Biomed Anal ; 5(8): 829-33, 1987.
Article in English | MEDLINE | ID: mdl-16867459
14.
Postgrad Med J ; 62(733): 1001-6, 1986 Nov.
Article in English | MEDLINE | ID: mdl-3628142

ABSTRACT

The relationships between serum uric acid, serum glucose and diabetes have been examined in a survey of 7735 middle-aged men drawn at random from general practices in 24 British towns. There was a positive relationship between serum glucose and serum uric acid concentrations up to about 8.0 mmol/l; at higher levels of glucose, serum uric acid decreased. Uric acid levels were significantly reduced in insulin-dependent diabetics and in those on oral hypoglycaemics and also in 'non-diabetics' with casual glucose levels greater than 10 mmol/l. Both uric acid and glucose concentrations were positively related to body mass index; only uric acid was positively related to alcohol intake. Men on antihypertensive treatment had raised levels of uric acid (significant) and glucose (non-significant). The positive relationship between serum uric acid and serum glucose could not be explained by associations with body mass index, alcohol intake, age, social class, gout or treatment for hypertension. It probably reflects the biochemical interaction between serum glucose and purine metabolism, with increased excretion of uric acid during hyperglycaemia and glycosuria.


Subject(s)
Blood Glucose/metabolism , Diabetes Mellitus/blood , Uric Acid/blood , Adult , Alcohol Drinking/physiology , Coronary Disease/blood , Creatinine/blood , Humans , Male , Middle Aged , Risk
15.
Clin Chem ; 32(10): 1884-9, 1986 Oct.
Article in English | MEDLINE | ID: mdl-3757207

ABSTRACT

The operation and results of the United Kingdom External Quality Assessment Scheme for Lead in Blood, which currently has about 140 participants within and outside the U.K. are described. The choice of specimens, scheme design, and scoring of performance are discussed, as is the validity of the consensus values used as a basis for the scoring. There has been a continued improvement in performance as assessed by this program, some of which appears to have been stimulated by the introduction of Variance Index scoring. The relative performance of the methods for assaying lead in blood is also examined.


Subject(s)
Lead/blood , Evaluation Studies as Topic , Humans , Laboratories/standards , Methods , Quality Control , Statistics as Topic
16.
Ann Clin Biochem ; 23 ( Pt 5): 577-84, 1986 Sep.
Article in English | MEDLINE | ID: mdl-3767296

ABSTRACT

The design and results of a UK external quality assessment scheme for six enzymes are described, from 21 surveys over a period of 7 years. Improvements in interlaboratory agreement and the adoption of reliable methods are documented. The potential of enzyme calibration materials in further improving numerical concordance between laboratories using different assay conditions, including temperature, is demonstrated and discussed.


Subject(s)
Enzymes/blood , Laboratories/standards , Humans , Quality Control
17.
J Biolumin Chemilumin ; 1(1): 29-34, 1986 Jun.
Article in English | MEDLINE | ID: mdl-3332547

ABSTRACT

A conventional colorimetric peroxidase end-point (ortho-phenylenediamine substrate), used in an enzyme immunoassay for carcinoembryonic antigen, employing plastic beads as solid support, has been replaced by a much faster (30 seconds versus 30 minutes) enhanced chemiluminescent assay for the peroxidase label. Para-iodophenol was used to enhance the light emission from the peroxidase catalysed chemiluminescent reaction between luminol and hydrogen peroxide. Values for precision and carcinoembryonic antigen concentration obtained with the chemiluminescent and colorimetric versions of the immunoassay on 62 serum specimens were in good agreement.


Subject(s)
Carcinoembryonic Antigen/analysis , Immunoenzyme Techniques , Luminescent Measurements , Carcinoembryonic Antigen/standards , Evaluation Studies as Topic , Humans
18.
Ann Clin Biochem ; 23 ( Pt 3): 317-24, 1986 May.
Article in English | MEDLINE | ID: mdl-3789639

ABSTRACT

The development of a simple enzymatic method for the determination of blood and plasma pyridoxal 5'-phosphate (PLP) using pig heart apo-aspartate transaminase (apo-AST) is described. The technique requires three steps: sample extraction using perchloric acid, a binding step in which PLP in the sample extract is attached to the apo-AST and the enzymatic assay of the reconstituted holo-AST. PLP extracts were analysed with and without a known concentration of added PLP to correct for variation in recovery between different specimens. Procedures are outlined for manual and automatic analysis of the PLP extracts. Using the KONE Clinical Analyser after the extraction step, it is possible to measure enzyme activity in 100 specimens (i.e. 400 tubes) in a 5 h period. Results are shown from 185 healthy women aged 20-45 years, in which plasma PLP concentrations ranged from 5 to 165 nmol/L, and 142 men and 56 women in government service aged 17-64 years, whose plasma PLP ranged from 8 to 169 nmol/L. Values less than 20 nmol/L are believed to indicate vitamin B6 deficiency and the method is able to measure 5 nmol/L.


Subject(s)
Apoenzymes/metabolism , Apoproteins/metabolism , Aspartate Aminotransferases/metabolism , Myocardium/enzymology , Pyridoxal Phosphate/blood , Adolescent , Adult , Animals , Biological Assay , Enzyme Activation/drug effects , Female , Humans , Male , Middle Aged , Pyridoxal Phosphate/pharmacology , Swine
19.
Hum Nutr Clin Nutr ; 40(3): 205-20, 1986 May.
Article in English | MEDLINE | ID: mdl-3087915

ABSTRACT

The effects of combined oral contraceptives containing 30 or 50 micrograms ethinyl oestradiol and 150 micrograms levonorgestrel or a 3-monthly injectable preparation depo-medroxyprogesterone acetate (DMPA) on the vitamin status of low-income group women from two urban centres in India (Bombay and Hyderabad) and one rural centre in Thailand (Chiang Mai) were examined in a follow-up study over a period of 1 year. The magnitude of malnutrition in the study population vis-à-vis a middle-income reference group was assessed by comparing the baseline data on the two groups. Effects of time-related variables such as lactation and season were also examined by a cross-sectional analysis of the baseline data on the study population. In all three centres the majority of the study population suffered from biochemical riboflavin and/or pyridoxine deficiency even before initiating contraception. Lactation appeared to have an effect on the vitamin status, which varied among the different populations. Seasonal effects were seen, but showed inconsistent trends in the three centres. Both the oral contraceptive pills and DMPA tended to increase serum vitamin A and blood folate. The thiamin, riboflavin and pyridoxine status of the women who were already deficient did not deteriorate further with the use of hormonal contraception, as judged by enzyme saturation tests. Some deterioration in the riboflavin status of the normal women of Hyderabad was seen with the use of oral pills. Women who were biochemically deficient prior to the use of oral contraceptives tended to show some improvement in B-vitamin status, over the 1-year period of hormonal contraception.


Subject(s)
Avitaminosis/blood , Contraceptive Agents, Female/pharmacology , Vitamins/blood , Adolescent , Adult , Body Weight , Contraceptive Agents, Female/administration & dosage , Contraceptives, Oral, Combined/pharmacology , Double-Blind Method , Ethinyl Estradiol/administration & dosage , Female , Humans , Lactation , Levonorgestrel , Medroxyprogesterone/pharmacology , Norgestrel/administration & dosage , Pregnancy , Social Class
20.
Br Med J (Clin Res Ed) ; 292(6519): 515-9, 1986 Feb 22.
Article in English | MEDLINE | ID: mdl-3081149

ABSTRACT

The concentration of high density lipoprotein cholesterol (HDL cholesterol) in serum was measured at initial examination in a large prospective study of men aged 40-59 drawn from general practices in 24 British towns. After an average follow up of 4.2 years 193 cases of major ischaemic heart disease had been registered in 7415 men in whom both HDL cholesterol and total cholesterol values had been measured. The mean HDL cholesterol concentration was lower in the men with ischaemic heart disease ("cases") compared with other men, but the difference became small and non-significant after adjustment for age, body mass index, blood pressure, cigarette smoking, and concentration of non-HDL cholesterol. The higher mean concentration of non-HDL cholesterol in "cases" remained highly significant after adjustment for other factors. Men in the highest fifth of non-HDL cholesterol values had over three times the risk of major ischaemic heart disease compared with men in the lowest fifth. Multivariate analysis showed that non-HDL cholesterol was a more powerful predictor of risk than the HDL to total cholesterol ratio. These British findings were compared with six other prospective studies. All the larger studies showed similar results, suggesting that HDL cholesterol is not a major risk factor in the aetiology of ischaemic heart disease.


Subject(s)
Cholesterol, HDL/blood , Coronary Disease/etiology , Adult , Cholesterol/blood , Coronary Disease/blood , Humans , Male , Middle Aged , Prospective Studies , Risk , United Kingdom
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