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PubMed2002

Prognostic significance of selected immunohistochemical parameters in patients with invasive breast carcinoma concomitant with ductal carcinoma in situ.

The purpose of the present study was to carry out multivariate analysis of the effect of the expression of estrogen and progesterone receptors, p53, proliferative antigen (Ki67) and c-erbB-2 on 5-year survival in patients with invasive breast carcinoma concomitant with ductal carcinoma in situ. Material for study consisted of tissue specimens obtained from 48 patients undergoing modified Patey's mastectomy between 1991 and 1998. Univariate analysis revealed that the variables significantly affecting survival were tumour size on gross examination and the level of estrogen and progesterone receptors in the cells of invasive ductal carcinoma of the breast (for the level of significance p = 0.05). The Cox regression model revealed that the only independent variable having a significant effect on survival was the level of estrogen receptors in invasive cancer cells.

Adult↗
PubMedDate not supplied

C-reactive-protein and cytokine plasma levels in hemodialysis patients.

BACKGROUND: Markers of an acute phase reaction, such as C-reactive protein (CRP) or interleukin-6 (IL-6), are predictive for cardiovascular morbidity and mortality in normal subjects and in hemodialysis (HD) patients. Le-vels of acute phase proteins (APP) may vary with time even in the absence of an acute illness and this may weaken the relationship between APP and clinical outcome. We investigated the intra- and inter-individual patterns of several inflammatory markers in HD patients. METHODS: Plasma levels of CRP, IL-10, RANTES, TNF-RI, leptin, ferritin and albumin were measured weekly for 12 weeks after the long inter-dialytic interval by ELISA in ten stable HD patients with no clinical signs of infection. RESULTS: Considerable variability was observed. Intra-individual differences were largest for RANTES (coefficient of variation - CV - 80%, followed by CRP (51%), and low for albumin (11%) and ferritin (12%). Inter-individual variability was highest for IL-10 (135%) followed by CRP (88%). CONCLUSIONS: The present data suggest that single point measurements of APP, particularly CRP, may not be sufficient to assess the cardiovascular risk in HD patients. Even in patients with no apparent signs of infection, there is considerable variability in plasma levels of APP and repeated measurements are recommended to identify patients at high cardiovascular risk.

Aged↗
PubMed2002

Development of reference ranges in elite athletes for markers of altered erythropoiesis.

BACKGROUND AND OBJECTIVES: Our previous research developed two statistical models that are useful indicators of current (ON-model) or recently discontinued (OFF-model) recombinant human erythropoietin (rHuEPO) use by athletes. The component variables of the ON-model are hematocrit (Hct), reticulocyte hematocrit (RetHct), serum erythropoietin (EPO), percent macrocytes (%Macro), and soluble transferrin receptor (sTfr), whilst the OFF-model uses only the first three variables. Genetics and training modalities of elite athletes may conceivably produce unusual values for blood parameters related to erythropoiesis. The aims of this study were to develop reference ranges in elite athletes for key hematologic parameters as well as ON- and OFF-models scores, and to evaluate the effect of ethnicity, gender, residence at moderate altitude (approximately 2000 m) and within-individual variation on the variables and model scores. DESIGN AND METHODS: Over a period of three weeks, 413 female and 739 male elite athletes from 12 countries visited laboratories to provide three blood samples for analysis of blood parameters sensitive to erythropoiesis. For each parameter and for the ON- and OFF-model scores, we used mixed modeling to establish the range within which we could be 95% certain that the value for a randomly chosen athlete would fall, taking into account various random effects (variation within and between subjects and laboratories) and fixed effects (means for different levels of ethnicity, age, sport, altitude of residency). We performed similar analyses for changes in the ON- and OFF-model scores between the three visits. RESULTS: Most fixed effects were accompanied by clear-cut, small to moderate differences in several parameters. However, residency at moderate altitude was accompanied by a much higher hematocrit than residency nearer sea level, with the mean (and 95% confidence limits) for the difference being 2.3 (0.9 to 3.7) and 1.8 (0.1 to 3.5) units for males and females, respectively. Males at altitude also demonstrated a moderately higher ON-model score. Otherwise the influence of these effects was small for ON-, OFF- and changes in model scores. INTERPRETATION AND CONCLUSIONS: Assessment of an athlete's blood parameters and ON- and OFF-model scores may need adjustment for training modalities and other characteristics of the subject. Changes in model scores (together with monitoring of urine samples for the presence of rHuEPO) provide a promising approach to detection of rHuEPO abuse, because they are less sensitive to subject characteristics and less variable than raw model scores.

Adolescent↗
PubMed1992

A prognostic role for ceruloplasmin in the diagnosis of indolent and recurrent inflammation.

Ceruloplasmin is increased in infections, inflammatory diseases, and neoplastic diseases and may be scarcely visible to the naked eye because it imparts a faint green color to the serum. This poses an interesting question as to a possible prognostic role for ceruloplasmin in the diagnosis of persistent or recurrent infection. The clinical course of 50 patients with tainted serum was reviewed retrospectively and ceruloplasmin levels correlated with diagnosis and outcome. Group I consisted of 20 healthy controls with normal ceruloplasmin levels: 35.1 +/- 2.0 mg/dL (range 25 to 45 mg/dL). Group II was made up of 23 surgical patients; 10 of these patients had elevated levels of ceruloplasmin, nine of whom had significant infections (64.2 +/- 3.2 mg/dL), and one patient was on estrogen (73.7 mg/dL). Group III consisted of 27 medical patients; 25 of these patients had elevated levels of ceruloplasmin, 20 of whom had infections (54.1 +/- 2.6 mg/dL), and five had malignancies (61.0 +/- 3.0 mg/dL). Ceruloplasmin levels were consistently elevated in all patients with infections relative to controls (P less than .001) with a variable response in other disease states. Therefore, ceruloplasmin may be useful as a serum marker for indolent or recurrent infections.

Biomarkers↗
PubMed2004

Prediction of in-hospital mortality by brain natriuretic peptide levels and other independent variables in acutely ill patients with suspected heart disease.

BACKGROUND: Brain natriuretic peptide (BNP) measurement can detect and assess heart failure. However, compared with traditional clinical parameters, its value for predicting the in-hospital mortality of patients with suspected heart disease has not been reported. STUDY DESIGN: Examination of the ability of 11 continuous and 22 categorical variables, including BNP levels measured at the time of admission, was conducted to predict in-hospital mortality. SETTING: A small, rural Irish hospital. SUBJECTS: Six hundred forty-two consecutive patients with suspected heart disease admitted as acute medical emergencies. RESULTS: Thirty-eight (5.9%) patients died while in hospital. They had significantly higher BNP levels on admission than did patients subsequently discharged alive (763+/-473 pg/mL versus 368+/-412 pg/mL, P<0.0001). Patients who died in hospital were older; had significantly higher white blood cell counts, blood urea, respiratory rates and modified early warning scores; and had significantly lower blood pressure and hemoglobin levels. Five variables were found to be independent predictors of mortality: a systolic blood pressure of 90 mmHg or less; a hemoglobin level of 100 g/L or less; a white blood cell count greater than 13.0 x 10(9)/L being unwell before the current illness; and a BNP level of 700 pg/mL or greater. The presence of three or more of these variables was associated with an in-hospital mortality rate of 39%. CONCLUSIONS: Five independent variables (hypotension, anemia, leukocytosis, prior illness and elevated BNP levels) are comparable predictors of in-hospital mortality in patients with suspected heart disease.

Adolescent↗
PubMed1998

Patterns of radiological progression in early rheumatoid arthritis: results of an 8 year prospective study.

OBJECTIVE: To describe the course of radiological progression in a cohort of 126 patients presenting with early nonerosive rheumatoid arthritis (RA). METHODS: Criteria for recruitment to the study were fulfillment of the 1958 American Rheumatism Association criteria, absence of erosive disease at presentation and duration of symptoms less than 3 years. Radiographs of hands and feet at 0, 1, 2, 5, and 8 years were available on 114 patients and were scored by Sharp's method for erosion (ERO) and joint space narrowing (JSN). Eighty-six patients were typed for the RA susceptibility shared HLA-DR epitope. RESULTS: The feet showed greatest initial radiological progression, but tended to reach an earlier and lower plateau. ERO progressed more rapidly than JSN in the first 2 years, but in parallel thereafter. The relative proportion of ERO:JSN varied, 1:1 for the wrists, 4:1 for the proximal interphalangeal joints. Thirty-eight percent of joints were eroded at 2 years, 63% at 8 years. Four patterns of radiological progression were identified: flat or nonerosive disease in 29 patients, linear in 51, lag in 13, and plateau in 19 (irregular in 2). Changes in the rate of radiological progression were reflected by the time-integrated C-reactive protein over the same period. Rheumatoid factor titer was higher in the progressive groups compared to the flat group (p = 0.01). The RA susceptibility shared HLA-DR epitope was more frequent in the linear compared to the flat group (p = 0.03). CONCLUSION: A large proportion of joints become eroded in the first 2 years of early RA. The subsequent course of radiological progression is highly variable and cannot be easily explained by any single model.

Adolescent↗
PubMed1998

Urinary 2/16 alpha-hydroxyestrone ratio: correlation with serum insulin-like growth factor binding protein-3 and a potential biomarker of breast cancer risk.

Metabolism of estradiol occurs via two mutually exclusive hydroxylative pathways, yielding metabolites of divergent biological properties. 2-hydroxyestrone (2OHE1) is anti-estrogenic while 16 alpha-hydroxyestrone (16 alpha OHE1) is a potent estrogen. The ratio of 2OHE1 to 16 alpha OHE1 (2/16 alpha-OHE1 ratio) represents the net in vivo estrogenic activity. In this study, we sought to determine if the urinary 2/16 alpha-OHE1 ratio could be a predictor of breast cancer risk and the factors which influence this ratio. Variables analysed included age at diagnosis, menopausal status, parity, use of oral contraceptives, body mass index, serum levels of insulin-like growth factor-I (IGF-I), IGF binding proteins (BPs) and the presence of breast cancer. Serum and urine were collected from 65 breast cancer patients and 36 controls after an overnight fast. Urinary estrogen metabolites were measured by enzyme immunoassays while serum levels of IGF-I, BP-1 and BP-3 were determined by immunoradiometric assays. 2OHE1 levels and 2/16 alpha-OHE1 ratios were significantly lower (P < 0.05) while 16 alpha OHE1 levels were higher (P < 0.01) in cancer patients. Multiple linear regression analysis showed that levels of urinary metabolites were influenced by parity and breast carcinoma. 2/16 alpha-OHE1 ratio correlated positively with serum BP-3 level (P = 0.03). By multiple logistic regression, 2/16 alpha-OHE1 ratio was the most significant factor predictive of breast cancer. The odds ratio for women with higher 2/16 alpha-OHE1 ratios was 0.10 (0.03-0.38, 95% confidence interval). In conclusion, the profile of urinary estradiol metabolites was distinctly altered in breast cancer patients. In addition, BP-3 may be a potential mechanism by which estradiol metabolites influence breast cancer progression. As 16 alpha OHE1 has been shown to initiate neoplastic transformation of mammary epithelial cells, the 2/16 alpha-OHE1 ratio may serve as a biomarker of increased risk of breast cancer.

Age Factors↗
PubMed2006

Clinical significance of RCAS1 as a biomarker of uterine cancer.

OBJECTIVES: Expression of RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) is associated with prognosis of various malignancies including uterine cancer. Proteolytic cleavage of RCAS1 at extracellular domains (ectodomain shedding) yields soluble RCAS1. Although RCAS1 can induce apoptosis in normal peripheral lymphocytes, its biologic function in cancer patients is unclear. Here, we evaluated serum RCAS1 concentrations to clarify its biologic activity in uterine cancer. METHODS: Via ELISA, we measured serum RCAS1 concentrations in samples from 54 healthy blood donors and 113 patients-63 with cervical cancer and 50 with endometrial cancer. We also counted the peripheral lymphocyte number. We correlated via statistical means the RCAS1 values with patients' clinicopathologic variables. We assessed inhibition of growth of K562 cells, which express the putative RCAS1 receptor, via WST-1 assay of serum samples to clarify RCAS1's biologic activity. RESULTS: Uterine cancer patients had significantly higher serum RCAS1 concentrations than did healthy blood donors (P<0.05). Patients with adenocarcinoma had significantly higher RCAS1 concentrations than did those with squamous cell carcinoma (P=0.0340). RCAS1 values were also significantly associated with response to treatment (P<0.001). FasL and TNF-alpha serum concentrations were not significantly different for the different groups, however. The WST-1 assay showed that patients' serum induced K562 cell growth inhibition, but this effect partially recovered after immunodepletion of RCAS1. Peripheral lymphocyte number and serum RCAS1 concentration were inversely related (P=0.0310). CONCLUSION: RCAS1 may be a biomarker of uterine cancer because of its potential to predict results of uterine cancer treatment and inhibit growth of immune cells.

Adenocarcinoma↗
PubMed2004

OCT4: A sensitive and specific biomarker for intratubular germ cell neoplasia of the testis.

PURPOSE: OCT4 (POU5F1, OCT3) immunostaining highlights pluripotent cells (embryonal carcinoma and seminoma) in primary testicular germ cell tumors, but its relative usefulness in diagnosing intratubular germ cell neoplasia, unclassified (IGCNU) is not well established. The present study aimed to establish OCT4 as a sensitive and specific maker for IGCNU, a putative precursor for adult germ cell tumors. EXPERIMENTAL DESIGN: We evaluated OCT4 immunostaining in 44 cases of IGCNU from patients who had testicular germ cell tumors. In addition, 27 of the 44 IGCNU sections were also examined with antibodies to placenta-like alkaline phosphatase, the most frequently used immunohistochemical marker for intratubular germ cell neoplasia. Sections from the testes of 10 patients who had undergone orchiectomy for hormonal treatment of prostate cancer and from autopsies of 10 patients without histories of germ cell tumors were also examined for OCT4 immunostaining. The immunoreactivity of the autopsy tissues was determined with vimentin staining, and all were reactive. RESULTS: In all 44 of the cases, antibody to OCT4 marked the nuclei of nearly all of the dysplastic cells of intratubular germ cell neoplasia but not non-neoplastic testicular cells. The staining intensity was strong in every case, and there was little or no background staining. All 20 of the control specimens (10 orchiectomy specimens from prostate cancer patients and 10 testes from autopsies) were completely negative for OCT4. The 27 cases that were stained with antiplacenta-like alkaline phosphatase antibodies showed staining of variable intensity in the areas of intratubular germ cell neoplasia, and there was a high level of background staining artifact. CONCLUSIONS: OCT4 is a sensitive and specific maker for intratubular germ cell neoplasia.

Alkaline Phosphatase↗
PubMed1998

Assessment of subacute mammary inflammation by soluble biomarkers in comparison to somatic cell counts in quarter milk samples from dairy cows.

The usefulness of soluble markers in indirectly differentiating inflamed quarters from healthy quarters of 30 Holstein Friesian cows was tested over a follow-up period of 20 weeks. In comparison to N-acetyl-beta-D-glucosaminidase (NAGase), lactate dehydrogenase (LDH), Na+, K+ and Cl- the somatic cell counts (SCC) were determined in foremilk samples. The soluble parameters were measured by means of an autoanalyzer system (Beckman CX5CE) equipped with solid state ion electrodes. Due to different types of inflammatory reactions it is considered to be advantageous to perform two tests in parallel for assessing the mammary gland status. Cell-damaging processes should best be detected by measuring elevated LDH activity, whereas the impairment of the blood-udder barrier is recorded by the respective elevation of the indicators Na+ and Cl-. Among all variables, SCC included, the soluble parameters showed the least dispersions, whereas those of SCC were the most unfavourable in this respect. Moreover, NAGase/LDH and Na+/Cl- among all variables had the highest correlation coefficients of 0.85 and 0.86, respectively. Threshold values as decision limits are proposed. Additionally, an inter-quarter comparison and evaluation improved the diagnostic value of each indirect mastitis parameter analyzed. By means of discriminant analysis, it is shown that the distribution of inflammation within the udders of this herd was unequal.

Acetylglucosaminidase↗
PubMed2004

Analytical, practical and regulatory issues in prevention studies.

Prevention studies, as distinguished from studies investigating treatments for established disease, present some distinct challenges. Perhaps the most extensive experience with preventive agents is in the area of infectious diseases; vaccines have been extremely effective in preventing many such diseases. Vaccines have been, and continue to be, studied in other disease areas such as certain cancers, but as yet have not achieved success outside of infectious disease prevention. One obvious and important feature of prevention studies is that they enroll healthy individuals; thus such studies require particularly high standards for the safety of those enrolled (and those who might ultimately receive the product being tested). Prevention studies often need to be quite large, as the types of diseases most important to prevent tend to be uncommon. Large studies usually require simplified approaches; to ensure high quality of data on the key variables it may be necessary to compromise on the amount of data collected, frequency of data collection, and other aspects of trial design. The reliability of randomization and blinding may be especially important in these large studies, as bias could easily overwhelm the small effects that are usually sought. Often, biomarkers thought to indicate developing but as yet subclinical disease, will be important to evaluate; whether such markers can serve as primary endpoints in prevention studies has been a contentious issue in many contexts. Studies in older populations, such as those at risk for Alzheimer's Disease, raise challenges such as accounting for competing risks, and considering potential interactions of preventive agents with multiple medications often used by the elderly.

Clinical Trials as Topic↗
PubMed2006

Assessment of analytical reproducibility of 1H NMR spectroscopy based metabonomics for large-scale epidemiological research: the INTERMAP Study.

Large-scale population phenotyping for molecular epidemiological studies is subject to all the usual criteria of analytical chemistry. As part of a major phenotyping investigation we have used high-resolution 1H NMR spectroscopy to characterize 24-h urine specimens obtained from population samples in Aito Town, Japan (n = 259), Chicago, IL (n = 315), and Guangxi, China (n = 278). We have investigated analytical reproducibility, urine specimen storage procedures, interinstrument variability, and split specimen detection. Our data show that the multivariate analytical reproducibility of the NMR screening platform was >98% and that most classification errors were due to urine specimen handling inhomogeneity. Differences in metabolite profiles were then assessed for Aito Town, Chicago, and Guangxi population samples; novel combinations of biomarkers were detected that separated the population samples. These cross-population differences in urinary metabolites could be related to genetic, dietary, and gut microbial factors.

Biomarkers↗
PubMed2006

Autoantibodies, metalloproteinases and bone markers in rheumatoid arthritis patients are unable to predict their responses to infliximab.

OBJECTIVES: To identify biochemical, immunological and bone markers as predictors of rheumatoid arthritis (RA) patients' responses to infliximab. METHODS: A total of 76 patients with active RA (American College of Rheumatology criteria), refractory to disease-modifying anti-rheumatic drugs, including methotrexate, received infliximab (3 mg/kg) infusions at weeks 0, 2, 6, and then every 8 weeks in combination with methotrexate or leflunomide. At week 14, infliximab efficacy was evaluated using disease activity score (DAS)28. A serum sample, collected just before starting infliximab, was tested by ELISA (unless stated otherwise) for the following immunological markers: rheumatoid factor by agglutination and ELISA (IgA, IgG and IgM isotypes); anti-cyclic citrullinated protein; autoantibodies recognizing calpastatin domain I and its 27 C-terminal fragment, glucose-6-phosphate isomerase, alpha-enolase; anti-keratin and anti-perinuclear factor antibodies (immunofluorescence); biochemical markers: C-reactive protein (nephelometry), metalloproteinase-1 and -3, tissue inhibitors of metalloproteinases-1 and -2, antioxidants (vitamins A and E; selenium); bone resorption markers: pyridinoline, deoxypyridinoline, osteoprotegerin, soluble receptor activator of nuclear factor-kappaB ligand, cartilage oligomeric matrix protein. Each parameter's predictive value of the response to infliximab was analysed using Fisher's exact, Mann-Whitney and chi-square tests. Hierarchical clustering was performed with The Institute for Genomic Research (TIGR) multiple experiment viewer software. RESULTS: Good, moderate and non-responder rates were 6.5, 61.8 and 31.5%, respectively. No significant difference was observed between responders and non-responders, regardless of the serum parameters considered. Analysis of dichotomous or continuous variables failed to identify markers predictive of a good or poor response to infliximab. CONCLUSION: The search for soluble markers in RA patients' sera likely to predict response to infliximab because of their involvement in RA pathogenesis seems disappointing. However, because of the limited power to detect smaller differences in biomarkers, the present study is a preliminary exploratory analysis.

Adult↗
PubMed2005

Cytochrome c, a biomarker of apoptosis, is increased in cerebrospinal fluid from infants with inflicted brain injury from child abuse.

Previous studies suggest that delayed neuronal death occurs in patients with inflicted traumatic brain injury (TBI) from child abuse. It is unknown whether the mode of this delayed neuronal death represents apoptosis or necrosis, a distinction that carries therapeutic ramifications. Cytochrome c, an electron transport chain component, can be released from mitochondria under conditions of cellular stress, whereupon it can initiate and serve as a biomarker of apoptosis. To resolve this issue, cytochrome c concentration was determined in 167 ventricular cerebrospinal fluid (CSF) samples from 67 infants and children with TBI (including 15 patients diagnosed with child abuse) by ELISA. Controls included lumbar CSF from 19 infants and children without trauma or meningitis. A multivariate model adjusted for multiple within-subject observations was used to identify clinical variables associated with CSF cytochrome c. Other apoptosis-related proteins were also examined in a subset of TBI patients. Increased CSF cytochrome c was independently associated with inflicted TBI (P=0.0001) and female gender (P=0.04), but not age, Glasgow coma scale score, or survival. Other apoptosis-related proteins including Fas and caspase-1 were increased in CSF after TBI, but did not independently discriminate between accidental and inflicted TBI. These data suggest that apoptosis, as detected by the presence of cytochrome c in CSF, is uniquely prominent among the subset of TBI patients diagnosed with child abuse. The degree of apoptosis after TBI also appears to be gender-dependent. Development of strategies targeting apoptosis after TBI, particularly in victims of child abuse and in girls, appears justified.

Apoptosis↗
PubMed2005

Chemical fingerprinting of petroleum biomarkers using time warping and PCA.

A new method for chemical fingerprinting of petroleum biomakers is described. The method consists of GC-MS analysis, preprocessing of GC-MS chromatograms, and principal component analysis (PCA) of selected regions. The preprocessing consists of baseline removal by derivatization, normalization, and alignment using correlation optimized warping. The method was applied to chromatograms of m/z 217 (tricyclic and tetracyclic steranes) of oil spill samples and source oils. Oil spill samples collected from the coastal environment in the weeks after the Baltic Carrier oil spill were clustered in principal components 1 to 4 with oil samples from the tank of the Baltic Carrier (source oil). The discriminative power of PCA was enhanced by deselecting the most uncertain variables or scaling them according to their uncertainty, using a weighted least squares criterion. The four principal components were interpreted as follows: boiling point range (PC1), clay content (PC2), carbon number distribution of sterols in the source rock (PC3), and thermal maturity of the oil (PC4). In summary, the method allows for analyses of chromatograms using a fast and objective procedure and with more comprehensive data usage compared to other fingerprinting methods.

Accidents↗
PubMed2006

Survival prediction in patients with glioblastoma multiforme by human telomerase genetic variation.

PURPOSE: Glioblastoma multiforme (GBM) is the most common and aggressive glioma with the poorest survival. Use of biomarkers for screening patients with GBM may be used to modify treatments and improve outcomes. The level of human telomerase (hTERT) expression is an independent predictor of outcome of many cancers, and a functional variant of hTERT MNS16A (shorter tandem repeats or short [S] allele) is associated with increased hTERT mRNA expression. We investigated whether hTERT MNS16A variant genotype predicted survival in GBM patients. PATIENTS AND METHODS: We genotyped hTERT MNS16A in 299 GBM patients using polymerase chain reaction and determined hTERT genotype by classifying the DNA band of 243 or 272 base pairs (bp) as S allele and 302 or 333 bp as long (L) allele. We compared overall survival using Kaplan-Meier estimates and equality of survival distributions using the log-rank test, and we computed univariate and multivariate Cox proportional hazards models to estimate the effects of selected variables. RESULTS: Overall survival differed significantly by hTERT MNS16A genotype, with median survivals of 25.1, 14.7, and 14.6 months for the SS, SL, and LL genotypes, respectively. Compared with the SS genotype, the hazard ratios for the SL and LL genotypes were 1.69 and 1.87, respectively, after adjustment for other factors. Multivariate Cox regression analysis showed an independent statistically significant association between the hTERT MNS16A variant genotype and outcome. CONCLUSION: A functional hTERT MNS16A genotype is a potential biomarker for assessment of survival outcome of GBM. Larger studies are needed to verify these findings.

Adult↗
PubMed2001

Oltipraz chemoprevention trial in Qidong, People's Republic of China: results of urine genotoxicity assays as related to smoking habits.

A Phase II chemoprevention trial was carried out in Qidong, Jiangsu Province, People's Republic of China. The recruited subjects, all of whom were positive for serum aflatoxin-albumin adducts, were divided into three treatment arms: placebo; oltipraz ([5-(2-pyrazinyl)-4-methyl-1,2-dithiol-3-thione]) given daily at 125 mg p.o.; and oltipraz given once per week at 500 mg p.o. Besides biomarkers related to aflatoxin B(1) exposure, the genotoxicity of blind-coded urine XAD-2 concentrates was evaluated in 201 subjects on the fifth and seventh week of intervention. Genotoxicity was assessed both in the Ames reversion test in strain YG1024 of Salmonella typhimurium, in the presence of an exogenous metabolic system (S9 mix), with or without beta-glucuronidase, and in a DNA repair test in Escherichia coli. Heating of concentrated urine samples or of cigarette smoke condensates was discovered to result in a significant enhancement of their mutagenicity. It was also found that the mutagenicity of condensates from the most extensively used brands of cigarettes in Qidong was much lower than that of Western cigarette brands. Urine mutagenicity was unrelated to treatment with oltipraz, intervention time, gender, and supplement of S9 mix with beta-glucuronidase. Mutagenicity was significantly but variably higher in cigarette smokers than in nonsmokers, which suggests that the urinary excretion of mutagens in the examined population was not exclusively attributable to smoking. Nevertheless, within smokers (28% of the recruited subjects; 67% of all males), the mutagenic potency was significantly correlated with the self-reported number of cigarettes smoked per day and, even more sharply, with the cotinine concentrations in urines. In conclusion, this study demonstrated the validity of urine mutagenicity assays as a biomarker of tobacco smoke exposure that can be investigated on a relatively large scale in chemoprevention trials and provided evidence that oltipraz treatment had no influence on this parameter in the examined population.

Administration, Oral↗