An assessment of dioxin exposure across gestation and lactation using a PBPK model and new data from Seveso

On July 10, 1976, an explosion at a chemical plant in Seveso, Italy, released up to 30kg of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-the most potent dioxin congener. Twenty years later, the Seveso Women's Health Study (SWHS) initiated a follow-up assessment of a cohort of female Seveso residents. Researchers collected serial blood, measured for TCDD levels, and recorded information about the women's medical history after the explosion. The study's aims were to: 1) modify the human PBPK model for TCDD (Emond et al. 2004; Emond et al. 2005; NCEA-USEPA, 2010) to include repetitive gestation and lactation; 2) simulate TCDD blood concentrations during different life stages including pregnancy and lactation, under different exposure scenarios; and 3) use this PBPK model to compare the influence of gestation and lactation on elimination of TCDD. After optimization of the model, it was assessed using data from the SWHS cohort. The 23 women in Subcohort A, were 4-39years old and in Subcohort B, the 18 women were 3-17years old when the explosion occurred. The model accurately predicted the blood concentrations during the 20years post-exposure, including periods of pregnancy and lactation. The model was also used to analyze the contribution of gestation and lactation to the mother's elimination of TCDD. The results suggest that gestation and lactation do not significantly impact TCDD blood elimination. Future efforts will focus on using additional data to evaluate the PBPK model and improving the mathematical descriptions of lactation and multiple gestations.

Addition of either pioglitazone or a sulfonylurea in type 2 diabetic patients inadequately controlled with metformin alone: impact on cardiovascular events. A randomized controlled trial

BACKGROUND AND AIMS

Metformin is the first-line therapy in type 2 diabetes. In patients inadequately controlled with metformin, the addition of a sulfonylurea or pioglitazone are equally plausible options to improve glycemic control. However, these drugs have profound differences in their mechanism of action, side effects, and impact on cardiovascular risk factors. A formal comparison of these two therapies in terms of cardiovascular morbidity and mortality is lacking. The TOSCA.IT study was designed to explore the effects of adding pioglitazone or a sulfonylurea on cardiovascular events in type 2 diabetic patients inadequately controlled with metformin.

METHODS

Multicentre, randomized, open label, parallel group trial of 48 month duration. Type 2 diabetic subjects, 50-75 years, BMI 20-45 Kg/m(2), on secondary failure to metformin monotherapy will be randomized to add-on a sulfonylurea or pioglitazone. The primary efficacy outcome is a composite endpoint of all-cause mortality, nonfatal myocardial infarction, nonfatal stroke, and unplanned coronary revascularization. Principal secondary outcome is a composite ischemic endpoint of sudden death, fatal and non-fatal myocardial infarction and stroke, endovascular or surgical intervention on the coronary, leg or carotid arteries, major amputations. Side effects, quality of life and economic costs will also be evaluated. Efficacy, safety, tolerability, and study conduct will be monitored by an independent Data Safety Monitoring Board. End points will be adjudicated by an independent external committee.

CONCLUSIONS

TOSCA.IT is the first on-going study investigating the head-to-head comparison of adding a sulfonylurea or pioglitazone to existing metformin treatment in terms of hard cardiovascular outcomes.

REGISTRATION

Clinicaltrials.gov ID NCT00700856.

Health status and plasma dioxin levels in chloracne cases 20 years after the Seveso, Italy accident

BACKGROUND

The Seveso, Italy accident of 1976 exposed a large population to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or simply dioxin). The accident resulted, mostly among children, in one of the largest ever-reported outbreaks of chloracne, the typical skin disorder due to halogenated-hydrocarbon compounds.

OBJECTIVES

Approximately 20 years after the accident, we conducted an epidemiological study in Seveso to investigate (a) the health status of chloracne cases; (b) TCDD-chloracne exposure-response relationship; and (c) factors modifying TCDD toxicity.

METHODS

From 1993 to 1998, we recruited 101 chloracne cases and 211 controls. Trained interviewers administered a structured questionnaire assessing, among other epidemiological variables, information on an extensive list of diseases. During the interview, individual pigmentary characteristics were determined. We measured plasma TCDD levels using high-resolution gas chromatography/mass spectrometry.

RESULTS

Plasma TCDD was still elevated (> 10 ppt) in 78 (26.6%) of the 293 subjects with adequate plasma samples, particularly in females, in subjects who had eaten home-grown animals, and in individuals with older age, higher body mass index and residence near the accident site. After 20 years, health conditions of chloracne cases were similar to those of controls from the Seveso area. Elevated plasma TCDD was associated with chloracne [odds ratio (OR) = 3.7, 95% confidence interval (CI) 1.6-8.8, adjusted for age, sex and residence]. Chloracne risk was higher in subjects younger than 8 years at the accident (OR = 7.4, 95% CI 1.8-30.3) and, contrary to previous hypotheses, did not increase at puberty onset or in teenage years. Subjects with elevated TCDD levels and light hair colour had higher relative odds of chloracne (OR = 9.2, 95% CI 2.6-32.5).

CONCLUSIONS

Dioxin toxicity in chloracne cases was confined to the acute dermatotoxic effects. Chloracne occurrence appeared related to younger age and light hair colour. Age-related dioxin elimination or dilution must be taken into account in interpreting these results.

The prevalence of Molar Incisor Hypomineralisation (MIH) in a group of Italian school children

AIM

This epidemiological study in a group of Italian children was undertaken in order to increase our knowledge of the prevalence of Molar Incisor Hypomineralisation (MIH) in different European countries.

METHOD

A population of school children aged 7.3 - 8.3 years, living in Lissone, Northern Italy, was examined for the presence and severity of MIH.

RESULTS

Of a total of 227 children (113 females), 31 (13.7%) had MIH, the tooth prevalence in the permanent first molars being 5.8%. Fifteen children (6.6%) had demarcated opacities in the incisors with a tooth prevalence of 2.1%. The defects in the molars were mild with the exception of one child who had severe defects.

CONCLUSION

MIH was quite common in this Italian town, and the prevalence figures were near those reported in Scandinavian countries but clearly higher than those from Dresden, Germany.

Contribution of proteomics to the molecular analysis of renal cell carcinoma with an emphasis on manganese superoxide dismutase

Renal cell carcinoma (RCC) originates in the renal cortex. It accounts for 2-3 percent of all cancers occurring in adults and it is characterised by lack of early clinical manifestations, unpredictable outcome, and absence of effective treatment modalities except early surgery. RCC comprises a heterogeneous group of tumours with various molecular and cytogenetic abnormalities and different histological features as cell types and tumour architecture. Molecular genetic and proteomic tools led to the discovery of potential diagnostic prognostic and therapeutic biomarkers of RCC. In this review we discuss recent developments in understanding genotype-phenotype relationships, with attention to manganese superoxide dismutase, a mitochondrial enzyme related to the redox cycle which affects various regulatory functions of cells. The expression of this protein has been evaluated in numerous human tumour types including RCC, and post-translational modifications are being investigated.

Seveso Women's Health Study: does zone of residence predict individual TCDD exposure?

The compound, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), is produced as an unwanted by-product of various chemical reactions and combustion processes, including the manufacture of chlorinated phenols and derivatives. In animals, TCDD exposure is associated with toxic, carcinogenic, developmental, and reproductive effects. In 1976, a chemical plant explosion in Seveso, Italy, exposed the residents in the surrounding community to the highest exposure to TCDD known in humans. Materials from an aerosol cloud of sodium hydroxide, sodium trichlorophenate and TCDD were deposited over an 18.1 km2 area. As evidence of the significant level of TCDD exposure, numerous animals died and 193 cases of chloracne were reported among residents of the area. Initially, the contaminated area was divided into three major exposure Zones (A, B, R) based on the concentration of TCDD in surface soils. To date, the majority of epidemiologic studies conducted in Seveso have used Zone of residence as a proxy measure of exposure. The purpose of the present study is to validate the use of Zone of residence in Seveso as a proxy measure of exposure against individual serum TCDD measurement, and to determine whether questionnaire information can improve the accuracy of the exposure classification. Using data collected from the Seveso Women's Health Study (SWHS), the first comprehensive epidemiologic study of the reproductive health of women in Seveso, we determined that Zone of residence is a good predictor of individual serum TCDD level, explaining 24% of the variance. Using questionnaire information could have improved prediction of individual exposure levels in Seveso, increasing the percent of the variation in serum TCDD levels explained to 42%.

Time trends of major coronary risk factors in a northern Italian population (1986–1994). How remarkable are socioeconomic differences in an industrialized low CHD incidence country?

BACKGROUND

The goals are to estimate time trends (1986-1994) of major coronary risk factors in an industrialized low CHD incidence population and to assess education class (EC) differences in risk factor prevalence and in time trends.

METHODS

Three population surveys were conducted in 1986-1987, 1989-1990 and 1993- 1994 on independent and two-stage age- and gender-stratified random samples (1906 men and 1941 women) of 35-64 year old residents of Brianza, an affluent region of northern Italy. The protocol for data collection, clinical measurements and biochemical determinations adhered to the WHO MONICA manual and underwent repeated quality control assessments. EC were identified according to gender- and 5-year birth-cohort specific tertiles.

RESULTS

In the initial, middle and final surveys 1258, 1259 and 1330 subjects were enrolled, corresponding to participation rates of 70.1%, 70.3% and 74.3%, respectively. Over the 8-year period, in men systolic blood pressure and smoking habits declined, body mass index and serum total cholesterol increased. In women systolic blood pressure showed a constant reduction, total cholesterol and BMI increased and the prevalence of smokers remained stable. Overall inverse associations with EC were found for body mass index, for prevalence of cigarette smokers in men and for systolic blood pressure in women. Decreases in blood pressure were more evident in the lowest EC. Cigarette smoking was on the decline in the higher EC in men. BMI and total cholesterol increased in all EC with the notable exception of the 'low' EC in women.

CONCLUSIONS

Favourable changes of the risk factor profile in the low socio-economic classes may have contributed to reduce CHD rates in this population. Specific policies oriented to lowest socio-economic classes are needed to continue to combat the smoking epidemic.

Environmental exposure to dioxin: the Seveso experience

The toxicity in humans of 2,3,7,8-tetrachlorodibenzo-p-dioxin, a man-made compound and environmental pollutant, is still debated. The industrial accident at Seveso, Italy, in 1976 exposed a large population of both sexes and of all ages to a massive concentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin. Monitoring of soil and measurement of blood samples allowed classification of the exposed population into three categories: A, B and R (high, medium and low exposure, respectively). This article presents data from longitudinal health monitoring of the population, including liver function, immune function, neurological impairment, dermatological effects, reproductive pathology, and mortality.

Heat shock proteins in human cancer

The heat shock proteins (hsp) are ubiquitous molecules induced in cells exposed to sublethal heat shock, present in all living cells, and highly conserved during evolution. Their function is to protect cells from environmental stress damage by binding to partially denatured proteins, dissociating protein aggregates, to regulate the correct folding, and to cooperate in transporting newly synthesized polypeptides to the target organelles. The molecular chaperones are involved in numerous diseases, including cancer, revealing changes of expression. In this review, we mainly describe the relationship of hsp expression with human cancer, and discuss what is known about their post-translational modifications according to malignancies.

Serum dioxin levels in Seveso, Italy, population in 1976

On July 10, 1976, an explosion at a chemical plant near Seveso, Italy, released a mixture of chemicals, including 2,3,7,8-tetrachlorodibenzo-p-dioxin and 2,4,5-trichlorophenol. As a result, several thousand people in the Seveso area may have been exposed to those chemicals. At that time, human exposure assessment was based primarily on soil levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin. Medical examinations of this potentially exposed population and control subjects were begun in 1976 and in some cases continued until 1985. In 1988, we began assessing human exposure in this population by measuring 2,3,7,8-tetrachlorodibenzo-p-dioxin in small volumes of serum specimens remaining from the medical examinations. As expected, we found that the median serum dioxin levels were highest among people who lived closest to the explosion and were progressively lower among groups living farther away. These measurements have allowed us to assess exposure more accurately among individuals in this population and to relate exposure to various health effects. We found that some individuals in the exposed population had among the highest serum dioxin levels ever reported, yet chloracne was the only unequivocal effect found; cancer risks are still being investigated. We also found that other individuals with as high or higher serum dioxin levels did not develop chloracne. We also found that the serum half-life of dioxin in this population was 7-8 years, which agrees with other findings although we do report some differences in the serum half-life of TCDD for women and children. We also observed an increase in the percentage of female newborns to parents who resided in Zone A at the time of the explosion, and we also report on the 1976 serum dioxin levels in people who later developed cancer.

Paternal concentrations of dioxin and sex ratio of offspring

BACKGROUND

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD or dioxin), is commonly considered the most toxic man-made substance. We have previously shown that high serum concentrations of TCDD in parents from Seveso, Italy, were linked to their having a relative increase in the number of female births after the parents exposure to a release of dioxin in 1976. We have continued the study to determine whether the parents' sex and/or age at exposure affected the sex ratio of their children.

METHODS

We measured the TCDD concentrations in serum samples from potentially exposed parents collected in 1976 and 1977, and investigated the sex ratio of their offspring.

FINDINGS

Serum samples were collected from 239 men and 296 women. 346 girls and 328 boys were born to potentially exposed parents between 1977 and 1996, showing an increased probability of female births (lower sex ratio) with increasing TCDD concentrations in the serum samples from the fathers (p=0.008). This effect starts at concentrations less than 20 ng per kg bodyweight. Fathers exposed when they were younger than 19 years of age sired significantly more girls than boys (sex ratio 0.38 [95% CI 0.30-0.47]).

INTERPRETATION

Exposure of men to TCDD is linked to a lowered male/female sex ratio in their offspring, which may persist for years after exposure. The median concentration of dioxin in fathers in this study is similar to doses that induce epididymal impairments in rats and is about 20 times the estimated average concentration of TCDD currently found in human beings in industrialised countries. These observations could have important public-health implications.

Seveso Women's Health Study: a study of the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on reproductive health

Although reproductive effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure have been reported in numerous investigations of animals, studies of this association in humans are limited. In 1976, an explosion in Seveso, Italy exposed the surrounding population to among the highest levels of TCDD recorded in humans. The relatively pure exposure to TCDD and the ability to quantify individual level TCDD exposure from sera collected in 1976 for the Seveso cohort affords a unique opportunity to evaluate the potential dose-response relationship between TCDD exposure and a spectrum of reproductive endpoints. The Seveso Women's Health Study (SWHS) is the first comprehensive study of the reproductive health of a human population exposed to TCDD. The primary objectives of the study are to investigate the relationship of TCDD and the following endpoints: (1) endometriosis; (2) menstrual cycle characteristics; (3) age at menarche; (4) birth outcomes of pregnancies conceived after 1976; (5) time to conception and clinical infertility; and (6) age at menopause. Included in the SWHS cohort are women who were 0-40 yr old in 1976, who have adequate stored sera collected between 1976 and 1980, and who resided in Zones A or B at the time of the accident. All women were interviewed extensively about their reproductive and pregnancy history and had a blood draw. For an eligible subset of women, a pelvic exam and transvaginal ultrasound were conducted and a menstrual diary was completed. More than 95% of the women were located 20 yr after the accident and roughly 80% of the cohort agreed to participate. Data collection was completed in July 1998, serum TCDD analysis of samples for analysis of endometriosis as a nested case-control study was completed in October 1998, and statistical analysis of these data should be completed in early 1999. Serum samples are now being analyzed in order to relate TCDD levels with the remaining reproductive outcomes.

Heat shock proteins in human cancer

The heat shock proteins (hsp) are ubiquitous molecules induced in cells exposed to sublethal heat shock, present in all living cells, and highly conserved during evolution. Their function is to protect cells from environmental stress damage by binding to partially denatured proteins, dissociating protein aggregates, to regulate the correct folding, and to cooperate in transporting newly synthesized polypeptides to the target organelles. The molecular chaperones are involved in numerous diseases, including cancer, revealing changes of expression. In this review, we mainly describe the relationship of hsp expression with human cancer, and discuss what is known about their post-translational modifications according to malignancies.

Human health effects after exposure to 2,3,7,8-TCDD

In 1949, the first descriptions of human exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD)-contaminated chemicals were reported after a trichlorophenol reactor explosion in Nitro, West Virginia, USA. Reported non-cancer health effects included a range of conditions affecting most systems. Additional reports of the health consequences of exposure continued through the remainder of the century. The majority of effects have been reported among highly exposed groups including occupational populations, such as chemical production workers, pesticide applicators, and individuals who handled or were exposed to materials treated with 2,3,7,8-TCDD-contaminated pesticides, and among residents of communities contaminated with tainted waste oil (Missouri, USA) and industrial effluent (Seveso, Italy). For only six exposed populations were biological measurements of 2,3,7,8-TCDD-contaminated collected and used to examine the relationship between non-cancer health effects and exposure. Of the many non-cancer health effects thought to be associated with 2,3,7,8-TCDD exposure, only chloracne, elevations in GGT and triglyceride levels, and alterations in FSH and LH were related to serum 2,3,7,8-TCDD levels. Mortality from cardiovascular diseases also appeared to be elevated among cohorts of exposed chemical workers and Seveso residents. Continued surveillance of the health of exposed populations will be useful in identifying the long-term effects of both high and low 2,3,7,8-TCDD exposure.

Modified expression of plasma glutathione peroxidase and manganese superoxide dismutase in human renal cell carcinoma

Two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) is a powerful tool to separate thousands of polypeptides and to highlight the modification of protein expression in malignant diseases. By applying 2-D PAGE to ten normal human kidney and ten homologous renal cell carcinoma (RCC) tissues, we found two peptides in all ten normal tissues but not in RCCs and, conversely, two peptides were detected in all RCCs but not in normal tissues. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and internal sequence analysis, the two first peptides were identified as two isoforms of plasma glutathione peroxidase (GPxP). The two other peptides isolated in all RCCs but not in normal tissues were identified by N-terminal sequence analysis as multimeric forms of manganese superoxide dismutase (Mn-SOD). No multimeric Mn-SODs and only two monomeric forms were detected in normal tissues. GPxP and Mn-SOD are metallo-enzymes encoded on chromosome 5q32 and on chromosome 6p25, respectively. Their regions are within the locus 5q21-->qter and 6q21-6q27 on which deletions and translocations are described in some cytogenetic studies of RCC transformation. Therefore, our results might suggest a correlation between the modified expression of GPxP and Mn-SOD in tumor tissues and chromosomal modifications, and that the two proteins may be putative markers for diagnosis of RCC.

Modified expression of plasma glutathione peroxidase and manganese superoxide dismutase in human renal cell carcinoma

Two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) is a powerful tool to separate thousands of polypeptides and to highlight the modification of protein expression in malignant diseases. By applying 2-D PAGE to ten normal human kidney and ten homologous renal cell carcinoma (RCC) tissues, we found two peptides in all ten normal tissues but not in RCCs and, conversely, two peptides were detected in all RCCs but not in normal tissues. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and internal sequence analysis, the two first peptides were identified as two isoforms of plasma glutathione peroxidase (GPxP). The two other peptides isolated in all RCCs but not in normal tissues were identified by N-terminal sequence analysis as multimeric forms of manganese superoxide dismutase (Mn-SOD). No multimeric Mn-SODs and only two monomeric forms were detected in normal tissues. GPxP and Mn-SOD are metallo-enzymes encoded on chromosome 5q32 and on chromosome 6p25, respectively. Their regions are within the locus 5q21-->qter and 6q21-6q27 on which deletions and translocations are described in some cytogenetic studies of RCC transformation. Therefore, our results might suggest a correlation between the modified expression of GPxP and Mn-SOD in tumor tissues and chromosomal modifications, and that the two proteins may be putative markers for diagnosis of RCC.

Exposure assessment: serum levels of TCDD in Seveso, Italy

Accurate exposure assessment is an important step in both risk assessment and epidemiologic studies involving potential human exposure to environmental toxicants. Various methods have been used to assess human exposure. These methods include models based on one's temporal and spatial nearness to the source, environmental levels of toxicant, and biological measures. We believe that the latter measure is the "gold standard." In this article we present the serum 2,3,7,8-tetrachlorodibenzo-p-dioxin levels in residents of the contaminated zones in Seveso, Italy, in 1976, and delineate these data by age and gender. Some of these serum levels are among the highest ever reported and thus this population serves as a benchmark for comparison of human exposure and potential adverse health effects. One such potential population is that population consuming potentially contaminated fish.

Controlling persistent organic pollutants-what next?

Within the context of current international initiatives on the control of persistent organic pollutants (POPs), an overview is given of the scientific knowledge relating to POP sources, emissions, transport, fate and effects. At the regional scale, improvements in mass balance models for well-characterised POPs are resulting in an ability to estimate their environmental concentrations with sufficient accuracy to be of help for some regulatory purposes. The relevance of the parameters used to define POPs within these international initiatives is considered with an emphasis on mechanisms for adding new substances to the initial lists. A tiered approach is proposed for screening the large number of untested chemical substances according to their long-range transport potential, persistence and bioaccumulative potential prior to more detailed risk assessments. The importance of testing candidate POPs for chronic toxicity (i.e. for immunotoxicity, endocrine disruption and carcinogenicity) is emphasised as is a need for the further development of relevant SAR (structure activity relationship) models and in vitro and in vivo tests for these effects. Where there is a high level of uncertainty at the risk assessment stage, decision-makers may have to rely on expert judgement and weight-of-evidence, taking into account the precautionary principle and the views of relevant stake-holders. Close co-operation between the various international initiatives on POPs will be required to ensure that assessment criteria and procedures are as compatible as possible.

[Seveso: biological monitoring of dioxin pollution. An example of environmental medicine. Multicentric and interdisciplinary applied research]

In 1976 the population of an area including Seveso (about 30,000) affected by the fallout of a toxic cloud containing 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) started a health monitoring plan which lasted until 1985. Smaller groups were monitored until 1997. The large number of people and the different toxic effects on organs have gathered different discipline experts including informatic. This work has permitted the not easy observation both of minor and bigger effects during two decades.

2,3,7,8-Tetrachlorodibenzo-p-dioxin plasma levels in Seveso 20 years after the accident

In 1976, near Seveso, Italy, an industrial accident caused the release of large quantities of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) into the atmosphere, resulting in the highest levels of the toxicant ever recorded in humans. The contaminated area was divided into three zones (A, B, R) corresponding to decreasing TCDD levels in soil, and cohort including all residents was enumerated. The population of the surrounding noncontaminated area (non-ABR) was chosen as referent population. Two decades after the accident. plasma TCDD levels were measured in 62 subjects randomly sampled from the highest exposed zones (A and B) and 59 subjects from non-ABR, frequency matched for age, gender, and cigarette smoking status. Subjects living in the exposed areas have persistently elevated plasma TCDD levels (range = 1.2-89.9 ppt; geometric mean = 53.2 and 11.0 ppt for Zone A and Zone B, respectively). Levels significantly decrease by distance from the accident site (p = 0.0001), down to general population values (4.9 ppt) in non-ABR, thus validating the original zone classification based on environmental measurements. Women have higher TCDD levels than men in the entire study area (p = 0.0003 in Zone B; p = 0.007 in non-ABR). This gender difference persists after adjustment for location within the zone, consumption of meat derived from locally raised animals, age, body mass index, and smoking. There is no evidence for a gender difference in exposure, so variation in metabolism or elimination due to body fat or hormone-related factors may explain this finding. Elevated TCDD levels in women may contribute to adverse reproductive, developmental, and cancer outcomes.

Plasma apolipoproteins A-I and B in survivors of myocardial infarction and in a control group

The values of apolipoproteins (apo) A-I and B were determined in a population sample of hospital outpatients with a standardized method to verify if the cutpoints calculated in a cross-sectional study in the US are usable with other populations. We also tested the apolipoproteins' ability to discriminate between healthy people and survivors of myocardial infarction. In the studied population the apo A-I value corresponding to the HDL-cholesterol decisional centile is 1.12 g/L for males and 1.17 g/L for females; the apo B value corresponding to the LDL-cholesterol decisional centile is 1.23 g/L for males and 1.14 g/L for females. These values are quite close to the cutpoints proposed for the American population (1.20 g/L for both apolipoproteins). In comparison with the LDL- and HDL-cholesterol decisional concentrations, the cutpoints for apolipoproteins allow a correct classification of a greater percentage of postmyocardial infarction patients (16% higher for apo B and 5% for apo A-I). Standardized assays coupled with a reference database allow a better clinical use of apolipoprotein measurements.

The European Register for Clinical Chemists. (European Communities Confederation of Clinical Chemistry, Working Group on Registration)

To ensure freedom of movement in the European Union, a limited number of professions is regulated by a so-called Sectorial Directive; all other disciplines, including clinical chemistry, fall under a General Directive. However, clinical chemists in the EU wish their specialty to be more specifically regulated; this means that common standards of education, training, experience and compliance with continuing professional developments must be guaranteed. Therefore, the European Communities Confederation of Clinical Chemistry (EC4) is about to implement the European Register for clinical chemists, and has composed a guide to this Register. The document describes the conditions for entry to specialty training, the minimum standards for registration (university education and postgraduate vocational training with a minimum total of eight years), the competencies of those qualifying for registration, and the operation of the register. Registration guarantees professional and managerial competencies; the title conferred is "European Clinical Chemist". EC4 recognises the existing national registers as far as they are based on the minimal requirements as indicated. An EC4 Register Commission (EC4RC) will maintain and control the European Register, supported by National Clinical Chemistry Registration Committees (NCCRC). An NCCRC controls the quality of the education in each country and assesses candidates. An individual (EU citizen or non-EU citizen trained in an EU country) applies privately for the European Register to EC4RC and, where applicable, the application is accompanied by a document from the NCCRC of the country of registration, stating that the applicant has the necessary qualifications. For EU citizens trained outside the EU the final decision is with EC4RC; non-EU citizens not trained in an EU country are not eligible for registration. Registration is renewed once every five years.

Results of a pilot study of endoscopic screening of first degree relatives of colorectal cancer patients in Italy

STUDY OBJECTIVE

Screening recommendations for colorectal cancer include sigmoidoscopy in asymptomatic, average risk persons aged 50 and over and colonoscopy every three to five years in high risk groups. Little is known about the eligible population's compliance with endoscopic screening. This is the first Italian report of an endoscopic screening programme for colorectal cancer patients' relatives.

DESIGN

In 1986, a pilot project for colorectal cancer screening by endoscopy in high risk subjects was started in the Desio (Milan, Italy) public health service region. The results obtained after seven years are described.

SETTING

The names of 536 inhabitants with colorectal cancer diagnosed between January 1975 and December 1984 and their relatives' addresses were obtained from the Regione Lombardia Health System records and from the municipal registry offices respectively.

PARTICIPANTS

From October 1986 to October 1993, 778 first degree relatives aged 20-75 were offered colonoscopy.

MAIN RESULTS

After seven years, 233 (29.9%) had undergone endoscopic examination, mostly up to the splenic flexure. Being > 60 in age at the start of the programme negatively affected the participation (p < 0.05). Two cancers were detected and adenomatous polyps were found in another 24 of those screened (frequencies 0.9% and 10.3% respectively). Male gender (p < 0.05), increasing age in males (p < 0.01), and two or more affected relatives in females (p < 0.01) positively affected the frequency of polyps detection.

CONCLUSION

These results suggest that about 30% of the eligible population would comply at least with sigmoidoscopic screening. The collaboration of family doctors and more widespread public information about the ability to cure colorectal cancer are necessary for better compliance.

Accuracy of cholesterol measurements in Italian clinical laboratories. Joint project GISSI prevention--Italian Society of Clinical Biochemistry. SIBioC GISSI Prevenzione Group

We report the results of an external quality assessment scheme for serum total cholesterol measurement involving about 100 Italian laboratories participating in an epidemiological study of post myocardial infarction. Two frozen human serum pools with Abell-Kendall assigned values are distributed quarterly at the laboratories (up to now seven events occurred); the obtained results are evaluated and discussed. In one exercise (# 5) duplicated measurements were repeated on three different days. Eighty-five to 98% of the laboratories obtained results within the total error limits (+/- 8.9%). But, while precision (calculated on the six replicates of exercise # 5) is good (90% of the laboratories obtained CV < 3%), inaccuracy problems are evident in every event. Indeed the mean bias from the reference method value ranged from 1.54 and 3.49% in the various events.

Renal cell carcinoma and normal kidney protein expression

Renal cell carcinoma (RCC), a human kidney cancer from the proximal tubular epithelium, accounts for about 3% of adult malignancies. Molecular and cytogenetic analysis have highlighted deletions, translocations, or loss of heterozygosity in the 3p21-p26, a putative RCC locus, as well as in 6q, 8p, 9pq, and 14pq. Studies on phenotypic expression of human kidney tissue and on post-translational modifications in RCC have not yet provided a marker for early renal cell carcinoma diagnosis. Current diagnostic methods do not help to detect the tumor before advanced stages. We therefore used two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) to study normal and tumor kidney tissues in ten patients suffering from RCC. A human kidney protein map in the SWISS-2DPAGE database accessible through the ExPASy WWW Molecular Biology Server was established. Of 2789 separated polypeptides, 43 were identified by gel comparison, amino acid analysis, N-terminal sequencing, and/or immunodetection. The comparison between normal and tumor kidney tissues showed four polypeptides to be absent in RCC. One of them was identified as ubiquinol cytochrome c reductase (UQCR), whose locus has elsewhere been tentatively assigned to chromosome 19p12 or chromosome 22. A second polypeptide was identified as mitochondrial NADH-ubiquinone oxido-reductase complex I whose locus is located on chromosome 18p11.2 and chromosome 19q13.3. These result suggest that the lack of UQCR and of mitochondrial NADH-ubiquinone oxidoreductase complex I expression in RCC may be caused by unknown deletions, or by changes in gene transcription or translation. It might indicate that mitochondrial disfunction plays a major role in RCC genesis or evolution.

Trends of smoking habits in northern Italy (1986-1990). The WHO MONICA Project in Area Brianza, Italy. MONICA Area Brianza Research Group

The trends of age-gender specific prevalence of self-reported smoking habits are presented, observed in two population surveys, performed in 1986-87 and 1989-90 in Area Biranza, a northern Italian industrialized district where a WHO MONICA Centre is located. Methods were internationally standardized to obtain comparable data on two independent random samples, each composed of 1,600 subjects, age-sex stratified and extracted from the 25-64 year old residents. A closed question interview was administered to identify smoking condition (smoker, past-smoker, occasional smoker, never smoker), number of cigarettes consumed per day and attained educational level, categorized in compulsory school and post-compulsory school. Serum thiocyanate was measured as a validation index, using a cutpoint of > 100 mumol l-1 to detect false negatives. Trends in smoking prevalence are analyzed taking into account influences of education in the presence of an anti-smoking policy that was started in Italy toward the end of the eighties. Self-reported data, confirmed by serum thiocyanate, show a consistent decline of smokers among males (from 48 to 41%), more evident in younger age groups. In females, smoking prevalence is stable (23-24%), although thiocyanate levels in the whole samples indicate a slight but significant tendency to decrease. Education demonstrates positive influences against smoking, particularly in younger male classes. In females a crossover effect is observable: in the second survey youngest group, education results protective against smoking; the contrary is true in the older groups. Our data, detailing what was initially recognized in previous Italian surveys, may be useful to specify the directions of future preventive actions.

Training and continuous education of clinical laboratory technologists and technicians

The profession of clinical laboratory technologist has undergone profound changes in the last decades and scientific as well as technological advancement will cause further continued evolution. Therefore, adaptability to a rapidly evolving environment and willingness to continuously update knowledge as well as skills seem to be the most important demands confronting technologists. I compare the current training of clinical laboratory technologist in industrialized countries with emerging educational schemes, which include curricula based on national requirements comprising a total of 3-4 years of formal lectures and practical training.

Granulocytic-macrophagic and macrophagic colony stimulating factors elicit colonies of mast cells in mouse bone marrow agar culture. An electron microscope study

Granulocytic-macrophagic colony stimulating factor (GM-CSF) and macrophagic colony stimulating factor (M-CSF or CSF-1) stimulate bone marrow cells of mouse to produce in semisolid agar colonies in which mononuclear cells were reported to be macrophages. We verified in such colonies the ultrastructure of the mononuclear cells which had cytoplasmic granules of the mast cells and lacked lysosomes, therefore we considered them as mast cells. However, the granules content did not reach the degree of condensation typically found in granules of mouse peritoneal mature mast cells. The mast cells of colonies obtained in agar can be mast cells arrested at some point in the maturative process, mast cells of a yet unrecognized type or cells with mast cells ultrastructural features which behave as precursors for cells of myeloid lineage.

Demographic and behavioural correlates of high density lipoprotein cholesterol. An international comparison between northern Italy and the United States

Recently published results of longitudinal follow-up studies conducted in the US have identified high density lipoprotein (HDL)-cholesterol as an independent and strong predictive factor for coronary heart disease (CHD). Some inconsistencies in this association have been found when geographical comparisons were done, which could be explained by hypothesizing differences in population HDL-cholesterol determinants. We carried out a comparative analysis of demographic and behavioural correlates of HDL-cholesterol between Northern Italy and the US, two countries with well-known differences in CHD risk and HDL-cholesterol levels. The study was conducted on representative samples of these two countries (MONICA Project-Area Brianza for Northern Italy and NHANES II for the US) and used comparable methodologies for data collection and statistical analysis. Results indicate that gender, age, body mass, cigarette smoking and alcohol consumption are independently associated with HDL-cholesterol in both populations; physical activity is positively, but not significantly, associated with HDL-cholesterol mean levels, and education achievement is independently associated only in the American sample. The comparison of the magnitude of the multivariate regression coefficients between the two studies suggests similar functional relationships for most of the correlates considered. The small, albeit significant, discrepancies found for body mass and smoking status could be related either to some methodological inconsistencies between the two surveys, or to possible effects of other covariates, not available to be tested in this study, like dietary habits. Moreover, HDL-cholesterol mean level differences between populations could be also due to differences in the prevalence of the examined correlates.

Ambulatory blood pressure normalcy: the PAMELA Study

Although ambulatory blood pressure monitoring is gaining in popularity, it still has important limitations in clinical use, particularly for the definition and diagnosis of hypertension. Various attempts have been made to calculate 'normal' or 'reference' values for ambulatory blood pressure, mostly by 24-h non-invasive monitoring in groups of 'normal' subjects. The most appropriate approach, however, is to compare 24-h ambulatory blood pressure values and casual or clinic blood pressure values in a random sample of a suitably large population. The PAMELA Study has been planned to obtain an epidemiological evaluation of 24-h ambulatory blood pressure values, and its design is described here. In the city of Monza, 2400 subjects aged between 25 and 64 years have been randomly selected according to World Health Organization Monitoring Cardiovascular Diseases (WHO-MONICA) project criteria within sex and age strata. In these subjects, clinic blood pressure, random-zero blood pressure, ambulatory blood pressure (24-h monitoring with SpaceLabs 90207; Redmond, Washington, USA), home blood pressure, electrocardiographic and echocardiographic indices, cardiovascular risk factors and psychological variables are being measured.

Cadralazine versus prazosin as second-step treatment in hypertensive patients on beta-blockers: a randomized multicentre study. The Italian Multicentre Study Group

A randomized multicentre between-patient study comparison has been made of the efficacy and tolerability of cadralazine and prazosin, both administered for 6 weeks to hypertensive patients with a supine diastolic blood pressure (DBP) greater than or equal to 95 mmHg whilst on a beta-adrenoceptor-blocker. The doses of the beta-adrenoceptor-blocker (metoprolol SR 200 mg once daily) and cadralazine (10 mg once daily) were held constant during the study, while prazosin was individually titrated from 0.5 mg to a maximum of 2 mg tds. 108 patients (50 m and 58 f; mean age 54 y) were enrolled in 12 centres. Twelve patients withdrew due to adverse effects or poor efficacy (5 patients on prazosin and 7 on cadralazine). Both treatments induced a similar significant reduction in systolic blood pressure (SBP) and DBP, allowing normalization of BP in 58% of subjects on cadralazine and 55% on prazosin. Heart Rate (hR) increased significantly from 67 to 72 beats.min-1 in those on cadralazine and from 65 to 69 beats.min-1 on prazosin. Body weight was unchanged. Adverse effects were mild and typical of vasodilators, such as headache, flushing and dizziness. Physician evaluation of drug efficacy was not different between drugs, and cadralazine was rated better in terms of tolerability. Thus, in this multicentre study, cadralazine in the fixed dose of 10 mg once daily, as a second-step antihypertensive treatment in patients not satisfactorily controlled by a beta-adrenoceptor-blocker, was as effective and showed a similar side effect profile to prazosin given three times daily.

Serum concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin and test results from selected residents of Seveso, Italy

2,3,7,8-Tetrachlorodibenzo-p-dioxin levels (TCDD) were measured in serum specimens from Seveso, Italy, residents, who were potentially highly exposed to the 1976 explosion, and in controls. The residents were chosen so as to represent those who did and did not develop chloracne. Levels of TCDD as high as 56,000 parts per trillion (ppt) were found in these serum specimens that were collected in 1976. These TCDD levels are the highest ever reported, and yet almost all clinical laboratory tests on these individuals were normal; any abnormal test result was only transitory in nature. These findings are unique in linking clinical histories to TCDD levels following an acute exposure.

Inefficacy of moving average algorithm as principal quality control procedure on Technicon System H6000

Bull's algorithm, in its "revisited" formulation, represents one of the main quality control (QC) procedures in several multichannel automatic hematological analyzers. Its efficacy, however, is reduced in the theoretical event that red blood cells (RBC) and hemoglobin (Hgb) undergo a concomitant analytical drift while mean corpuscular volume (MCV) remains unaffected, so that a null effect is registered on the related erythrocytic indices: mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC). This particular phenomenon has been observed on the Technicon System H6000. Routine daily work was kept in control through the use of commercial controls and fresh blood samples: a reproducible positive drift of two directly measured erythrocytic parameters (RBC and Hgb) and of the calculated hematocrit (Hct) was observed proportional to the time of continuous use of the instrument. The usefulness of Bull's QC scheme was greatly reduced: it failed to detect "out of control" situation in 38%, 15%, and 13% of cases in the monitoring of MCV, MCH, and MCHC, respectively, when compared with the traditional 2 SD limits on QC samples.

A new method for D-glucaric acid excretion measurement that is suitable for automated instruments

Urinary excretion of D-glucaric acid (uGA) is an index of type II hepatic microsomal enzyme induction, indirectly revealing possible organic effects of some drugs and environmental pollutants. However, its determination is often cumbersome. We suggest a new, fast microanalytical method for uGA determination in which beta-glucuronidase (BG; EC 3.2.1.31) activity inhibition produced by uGA-derived 1,4-D-glucarolactone is measured. With use of purified BG, the method is suitable for centrifugal analyzers, allowing assay of greater than 100 samples per day. Moreover, the method measures uGA more accurately than other enzymatic methods based on BG inhibition. The within-day CV ranges from 7.9% to 4.6% (uGA 31.55-121.31 mumol/L); the between-day CV ranges from 11.5% to 5.0% (uGA 26.09-124.10 mumol/L). The detection limit is 6.0 mumol/L. The standard curve is linear from 10 to 200 mumol/L. Mean analytical recovery is 100%. Comparison with the method of Simmons et al. (Clin Chim Acta 1974;51:47-51) gave a correlation of r = 0.978, y = 1.40x-2.81. Reference intervals were established in a healthy population sample of 369 people (165 under 14 y), and uGA, expressed in micromoles per gram of creatinine, was higher in women than in girls or in males.

A new method for D-glucaric acid excretion measurement that is suitable for automated instruments

Urinary excretion of D-glucaric acid (uGA) is an index of type II hepatic microsomal enzyme induction, indirectly revealing possible organic effects of some drugs and environmental pollutants. However, its determination is often cumbersome. We suggest a new, fast microanalytical method for uGA determination in which beta-glucuronidase (BG; EC 3.2.1.31) activity inhibition produced by uGA-derived 1,4-D-glucarolactone is measured. With use of purified BG, the method is suitable for centrifugal analyzers, allowing assay of greater than 100 samples per day. Moreover, the method measures uGA more accurately than other enzymatic methods based on BG inhibition. The within-day CV ranges from 7.9% to 4.6% (uGA 31.55-121.31 mumol/L); the between-day CV ranges from 11.5% to 5.0% (uGA 26.09-124.10 mumol/L). The detection limit is 6.0 mumol/L. The standard curve is linear from 10 to 200 mumol/L. Mean analytical recovery is 100%. Comparison with the method of Simmons et al. (Clin Chim Acta 1974;51:47-51) gave a correlation of r = 0.978, y = 1.40x-2.81. Reference intervals were established in a healthy population sample of 369 people (165 under 14 y), and uGA, expressed in micromoles per gram of creatinine, was higher in women than in girls or in males.

Clinical laboratory manifestations of exposure to dioxin in children. A six-year study of the effects of an environmental disaster near Seveso, Italy

Following a major environmental accident near Seveso, Italy, on July 10, 1976, we attempted to determine if the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) released into the atmosphere had any effect on the liver function and lipid metabolism of exposed children. From July 1976 to June 1982, we analyzed the results of more than 4500 laboratory tests (alanine aminotransferase, aspartate aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, cholesterol, and triglycerides in plasma and delta-aminolevulinic acid in urine) in a population of about 1500 children aged 6 to 10 years at the moment of the accident. The children exposed to the highest concentration of TCDD showed alterations in serum gamma-glutamyltransferase and alanine aminotransferase activity compared with the control group. These differences were restricted to values inside limits set from the lower end of the normal range to slightly above it. The observed abnormalities were slight and disappeared with time.

Colony-stimulating factor produced by murine adrenocortical tumor cells

Conditioned medium obtained from the adrenocortical LAF1 mouse tumor (Y-1) cell cultures was able to stimulate the proliferation and the differentiation of granulocyte-macrophage precursors in the normal murine bone marrow. Colony-stimulating factor (CSF) was spontaneously produced by Y-1 cells also in serum-free cultures. By two cycles of gel chromatography on Sephadex G-150 of concentrated conditioned medium two peaks of colony-stimulating activity were isolated that corresponded to apparent molecular radii of 100,000 and 29,000, respectively. At this step of purification, the two factors gave a similar dose-response curve, showed a remarkable resistance to the heat treatment and pH changes, and were not extracted by ether. Because Y-1 cells resulted in infection by retrovirus, they provide a useful model to investigate the relations between viral coded information and CSF production.

Colony-stimulating activity from the new metastatic TS/A cell line and its high- and low-metastatic clonal derivatives

We investigated the presence of colony-stimulating factor (CSF) in supernatants obtained from TS/A, a new metastatic murine cell line, and from its high-and low-metastatic clonal derivatives (E and F clones, respectively). TS/A cells produced a CSF in vitro that induced proliferation and differentiation of murine monocytic and granulocytic progenitors in agar cultures. In TS/A-bearing mice remarkable splenomegaly, blood granulocytosis and thymus depletion were observed along with a stimulatory activity in serum and a strong proliferative activity both in spleen and in bone marrow populations. Conditioned media from E clones showed an in vitro colony-stimulating activity greater than those of F clones. Mice injected subcutaneously with cells of all clones studied showed granulocytosis, splenomegaly and thymus depletion, although to varying degrees. However, no direct correlation between granulocytosis-splenomegaly and the number of spontaneous lung metastases was observed.