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M Colonna

Publications and source records attributed to M Colonna.

At least 19 recordsLinked to original sources
PubMed2003

Thyroid cancers in France and the Chernobyl accident: risk assessment and recommendations for improving epidemiological knowledge.

From 1975 to 1995, the incidence of thyroid cancer in the French population increased by a factor of 5.2 in men and 2.7 in women, thereby raising public concerns about its association with the nuclear accident at Chernobyl. A study performed at the request of French health authorities sought to quantify the potential risk of thyroid cancer associated with the Chernobyl fallout in France in order to determine if this risk could be observed through an epidemiological approach. The study focused on the most exposed population: those living in eastern France and younger than 15 y at the time of the Chernobyl nuclear power plant accident (26 April 1986). The number of spontaneous thyroid cancers in this population was predicted from French cancer registry data, and the thyroid doses were estimated from all available data about contamination in France. Associated risks were calculated with different risk models, all based on a linear no-threshold dose-effect relationship. Under this hypothesis, from 1.3 to 22 excess thyroid cancer cases were predicted for the 1991-2000 period, compared with the 212 spontaneous cases (0.5 to 10.5%) predicted, and from 11.2 to 55.2 excess cases were predicted for 1991-2015, compared with the 1,342 spontaneous cases (0.8 to 4.1%) predicted. These risk calculations indicate that the Chernobyl fallout cannot explain the entire increase in thyroid cancers in France, and that it is improbable that an epidemiological study could demonstrate such an excess. The surveillance of thyroid cancers in France should be enhanced.

Adolescent↗
PubMed2003

Cancer incidence and mortality in France over the period 1978-2000.

BACKGROUND: Monitoring cancer incidence and mortality time trends is essential for cancer research and health-care planning. French cancer registries do not cover the entire population and do not provide a representative sample of the national population. Our study aimed at estimating national cancer incidence and mortality trends over the longest period available. METHODS: Incidence and mortality data were collected over the period 1978-1997. Twenty-seven cancer sites were selected and age, sex and site specific incidence and mortality rates were estimated for each year from 1978 up to 2000. Observed incidence and mortality data in the population covered by cancer registries were modelled using age-cohort methods. An estimation of the incidence/mortality ratio was obtained from these models and applied to the mortality rates predicted from an age-cohort model for the entire French population. The person-years of observation were calculated cohort-wise from census data provided by the national institute of statistics RESULTS: Cancer incidence increased by 63% throughout the study period, from 170,000 new cases in 1980 to 278,000 in 2000. This evolution was due to demographic changes but also to an increase in the risk of cancer which was estimated to more than 35% during the same period. In men, this change is largely explain by the increase of prostate cancer incidence. Among women, the increase was dominated by the continuing increase in breast cancer incidence. Large increases were also seen for non-Hodgkin lymphoma, melanoma, and thyroid cancer in both genders and for lung cancer in women. Cancer mortality increased by 20% from 125,000 deaths in 1980 to 150,000 in 2000. This increase is less than that predicted from changes in demographic factors and corresponds in fact to a decrease in the risk of death estimated to about 8%, slightly greater for women than for men. This decrease is associated with a decreasing incidence for stomach cancers for both sexes, alcohol-related cancer for men and cervical cancer for women. Colo-rectal cancer decreasing mortality contributes to this improvement despite an incidence increase. CONCLUSION: Between 1980 and 2000, the study showed a large change in the cancer burden both quantitatively and qualitatively. Decrease in exposure, earlier diagnosis and therapeutic improvement explained part of this change, but overall the distribution of cancer cases shifted toward a distribution including less aggressive cancers. A striking divergence between incidence and mortality trends is observed for a great number of cancers. Prostate cancer shares with breast cancer the same pattern of a severe increasing incidence and a stable mortality. This points to important changes in medical practice and needs further analysis. The trend of lung cancer mortality among women should be emphasised since the situation will inevitably worsen in the coming years. It is already the third cause of cancer death among women.

Age Distribution↗
PubMed2002

Mechanical and chemical spinodal instabilities in finite quantum systems.

Self-consistent quantum approaches are used to study the instabilities of finite nuclear systems. The frequencies of multipole density fluctuations are determined as a function of dilution and temperature for several isotopes. The spinodal region of the phase diagrams is determined, and it appears that instabilities are reduced by finite size effects. The role of surface and volume instabilities is discussed. It is indicated that the important chemical effects associated with mechanical disruption may lead to isospin fractionation.

Journal Article↗
PubMed2002

Tolerization of dendritic cells by T(S) cells: the crucial role of inhibitory receptors ILT3 and ILT4.

Immunoglobulin-like transcript 3 (ILT3) and ILT4 belong to a family of inhibitory receptors expressed by human monocytes and dendritic cells. We show here that CD8+CD28(-) alloantigen-specific T suppressor (TS) cells induce the up-regulation of ILT3 and ILT4 on monocytes and dendritic cells, rendering these antigen-presenting cells (APCs) tolerogenic. Tolerogenic APCs show reduced expression of costimulatory molecules and induce antigen-specific unresponsiveness in CD4+ T helper cells. Studies of human heart transplant recipients showed that rejection-free patients have circulating TS cells, which induce the up-regulation of ILT3 and ILT4 in donor APCs. These findings demonstrate an important mechanism of immune regulation.

Antigen-Presenting Cells↗
PubMed2002

Contacts with animals and humans as risk factors for adult brain tumours. An international case-control study.

While numerous studies have addressed the possible role of farming and related exposures as risk factors for brain tumours in adults, few of them have examined the potential effect of exposure to farm animals or pets. In an international multicentre case-control study, we investigated whether residence on a farm, contact with animals, or working in occupations with a high degree of potential contact with animals or humans were associated with brain tumours. Using a common questionnaire, 1177 cases of glioma, 330 with meningioma and 2478 controls from eight centres were interviewed about the exposures and, in particular, about their contacts with nine species of animals: dairy cattle, beef cattle, pigs, horses, sheep, goats, poultry, dogs and cats. Living or working on a farm was not a risk factor, for either glioma or meningioma. Except in some centres, there was no relationship between having contacts with farm animals or pets and the risk of brain tumour, for either type of tumour or either sex. In relation to seven industrial groups involving frequent human and/or animal contacts, no association was apparent for either glioma or meningioma. In relation to 25 occupational groups with potential frequent contact with humans and/or animals, for glioma there was a reduced risk for biological technicians (Odds Ratio (OR)/=0, P=0.01), and general farm workers (OR=0.66, 95% Confidence Interval (CI): 0.5-0.9). For meningioma, there was an increased risk for cooks (OR=2.0; CI: 1.2-3.4). With some exceptions, these results indicate no association between either the type of brain tumour and contacts with animals, or with occupations that include a high level of contact with animals or a high level of contact with humans.

Adult↗
PubMed2002

Incidence of thyroid cancer in adults recorded by French cancer registries (1978-1997).

This article analyses time trends and geographical variations of thyroid cancer by histological type. Incidence data were provided by 8 French cancer registries over the period 1978-1997, with 3853 adult cases reported. To assess the effects of age, period, cohort and area on incidence, log-linear Poisson regression models were used. Thyroid cancer increased exponentially from the cohort born in 1925. This increase was essentially due to papillary cancer, which increased by 6.2% per year in men and 8.1% per year in women over the entire period (1978-1997). In women, the recent trends were significantly different between the studied geographical areas. The analysis shows that the increase in thyroid cancer, essentially of the papillary type, is not recent. It may be attributed to a possible screening effect or to an increase in the number of "incidentally" discovered cases linked to the use of modern diagnostic tools.

Adenoma↗
PubMed2002

Measuring cancer prevalence in Europe: the EUROPREVAL project.

Cancer prevalence is the proportion of individuals in a population who at some stage during their lifetime have been diagnosed with cancer, irrespective of the date of diagnosis. Cancer prevalence statistics have generally been provided by a limited number of well established cancer registries that have been in existence for several decades. The advent of systematic follow-up of life status of incident cases and the availability of new statistical methodologies, now makes it possible for registries established during the 1970s or 1980s to provide prevalence data. The main problems encountered in the estimation of prevalence are the inclusion of: (i) cases lost to follow-up; (ii) cases known only from their death certificate; (iii) cases diagnosed before the start of registration; and (iv) the treatment of multiple tumours and migrations. The main aim of this paper was to review these problems and discuss, through the experience gained with EUROPREVAL, how they can be overcome. A method is presented for the calculation of prevalence of all cancers combined in the populations covered by the 45 cancer registries participating in EUROPREVAL. Prevalence of cancer is estimated to be 2% on average, with the highest values (3%) in Sweden and the lowest in Eastern Europe, with a minimum of approximately 1% in Poland.

Adolescent↗
PubMed2002

A comparative analysis of cancer prevalence in cancer registry areas of France, Italy and Spain.

A comparative analysis of cancer prevalence in France, Spain and Italy is presented as part of the EUROPREVAL project. The three countries are culturally and sociologically relatively homogeneous compared with Europe as a whole. However, in all three countries, the cancer registries (CRs) providing the data for prevalence calculation cover only small fractions of the populations, and have been operating for relatively short periods. This leads to problems of representativity and to prevalence underestimates as surviving cases diagnosed before operation of the CR are not recorded. Partial prevalences obtained directly from CR data were therefore corrected using a completeness index obtained by modelling to provide estimates of the complete prevalence. For CRs operating for only 5 years, only approximately half the prevalence was observed. Thus, due to the rather recent start of most of southern European CRs, the role of correction is very important. The prevalence of all cancers was highest in Italy for women and in France for men, while lowest in Spain. Differences in the age structures of the populations were the major cause of these discrepancies and after age adjustment only the prevalence of stomach cancer remained highest in Italy, although differences in incidence also contributed to the prevalence differences. Survival varied little between the three countries and differences in incidence are more important determinants of prevalence. Prevalence of cancer in the elderly represents an increasing load for the community, particularly for France, Italy and Spain due to the ageing population in these countries. Elderly patients with cancer frequently suffer from problems of co-morbidity and disability factors, thus placing a burden on the local medical system where this proportion is high. Prevalent cases diagnosed 1-5 years before the prevalence date formed approximately one-third of the total prevalence, with higher proportions for melanoma, and prostate cancer in males and breast and colorectal cancer in females, and lower proportions for uterine cancer. This subset of the prevalent population consists of those probably on intensive follow-up, or being treated for cancer recurrence or sequelae to primary therapy.

Adult↗
PubMed2002

[Estimate of regional prevalence of colorectal cancer in France].

BACKGROUND: Colorectal cancer prevalence is an important determinant of the health demand that completes information provided by cancer incidence. Current estimations established from data for the years 1985 and 1995 can be used to establish a precise description of changing healthcare needs for colorectal cancer. METHOD: Prevalence estimates method were based on incidence data computed on the regional scale by the FRANCIM network and mortality data provided by INSERM. We used the relationship that exists between the net risk of cancer, the net risk of dying of the given cancer and the age-specific prevalence of cancer. RESULTS: In 1995, the prevalence of patients who had a diagnosis of colorectal cancer amounted to 200 000 persons. The estimated number of prevalent cases was never lower than 3500 in any region and in 7 regions this number was higher than 10 000. From 1985 to 1995, there has been an increase of 35% in the prevalence rates. CONCLUSION: The evaluation of the number of persons who have had a diagnosis of colorectal cancer provides knowledge for health care planning. Such information on the regional scale is very useful for the health organisation (SROS). This geographical level induces difficulties not encountered at the national level.

Colorectal Neoplasms↗
PubMed2002

[How to choose in practice a model to describe the geographic variation of cancer incidence? Example of gastrointestinal cancers from Côte-d'Or].

BACKGROUNDS: In epidemiology, standardized Incidence Ratio (SIR) can have large variance and it is then difficult to distinguish random fluctuations from real spatial variations when describing spatial variations in the rate of cancer. In this context, hierarchical model produce smoothed relative risks estimations helpful for solving this problem. The main advantage of these methods is to combine information of each geographical area with that obtained from prior assumption on the similarity between geographical sub-units. Nevertheless different assumptions produce different geographical maps of incidence of cancer, and the purpose of the present study was the development of a strategy to choose the most satisfactory description of the incidence of digestive cancer in a French department. METHODS: The strategy to choose the most satisfactory geographical map depends on the following criteria: variability between geographical sub-units, auto-correlation, and variability within geographical sub-unit. These criteria have been estimated from observed data for each site of cancer. RESULTS: This strategy was applied to digestive tract cancers diagnosed between 1976 and 1997 in the department of Côte-d'Or, France. High-risk areas were often detected in the urban zone of the department, but without autocorrelation in most cases. CONCLUSION: This strategy permitted to describe cancers in very small areas, avoiding to a large extent the danger of focusing on falsely positive high-risk areas.

Algorithms↗
PubMed2001

BDCA-2, a novel plasmacytoid dendritic cell-specific type II C-type lectin, mediates antigen capture and is a potent inhibitor of interferon alpha/beta induction.

Plasmacytoid dendritic cells are present in lymphoid and nonlymphoid tissue and contribute substantially to both innate and adaptive immunity. Recently, we have described several monoclonal antibodies that recognize a plasmacytoid dendritic cell-specific antigen, which we have termed BDCA-2. Molecular cloning of BDCA-2 revealed that BDCA-2 is a novel type II C-type lectin, which shows 50.7% sequence identity at the amino acid level to its putative murine ortholog, the murine dendritic cell-associated C-type lectin 2. Anti-BDCA-2 monoclonal antibodies are rapidly internalized and efficiently presented to T cells, indicating that BDCA-2 could play a role in ligand internalization and presentation. Furthermore, ligation of BDCA-2 potently suppresses induction of interferon alpha/beta production in plasmacytoid dendritic cells, presumably by a mechanism dependent on calcium mobilization and protein-tyrosine phosphorylation by src-family protein-tyrosine kinases. Inasmuch as production of interferon alpha/beta by plasmacytoid dendritic cells is considered to be a major pathophysiological factor in systemic lupus erythematosus, triggering of BDCA-2 should be evaluated as therapeutic strategy for blocking production of interferon alpha/beta in systemic lupus erythematosus patients.

Amino Acid Sequence↗
PubMed2001

The activatory receptor 2B4 is expressed in vivo by human CD8+ effector alpha beta T cells.

The membrane receptor 2B4 is a CD2 family member that is involved in lymphocyte activation. A fraction of human CD8+ alphabeta T cells up-regulate 2B4 in vivo, and here we demonstrate that this correlates with the acquisition of effector cell properties such as granzyme B and perforin expression, rapid IFN-gamma production, and down-regulation of the lymph node homing chemokine receptor CCR7. In PBLs from healthy donors, cytomegalovirus-specific effector T cells were 2B4 positive, whereas naive melanoma Ag (Melan-A/melanoma Ag recognized by T cells-1)-specific T cells were 2B4 negative. In melanoma patients, Melan-A-specific T cells up-regulated 2B4 in parallel with in vivo differentiation. This occurred in PBLs after vaccination with Melan-A peptides and in tumor-infiltrated lymph nodes, likely through disease-associated activation of Melan-A-specific T cells. Thus, 2B4 expression correlates with CD8+ T cell differentiation in vivo.

Antigens, CD↗
PubMed2001

Activation of NK cell-mediated cytotoxicity by a SAP-independent receptor of the CD2 family.

Some CD2 family receptors stimulate NK cell-mediated cytotoxicity through a signaling pathway, which is dependent on the recruitment of an adapter protein called SLAM-associated protein (SAP). In this work we identify a novel leukocyte cell surface receptor of the CD2 family called CD2-like receptor activating cytotoxic cells (CRACC). CRACC is expressed on cytotoxic lymphocytes, activated B cells, and mature dendritic cells, and activates NK cell-mediated cytotoxicity. Remarkably, although CRACC displays cytoplasmic motifs similar to those recruiting SAP, CRACC-mediated cytotoxicity occurs in the absence of SAP and requires activation of extracellular signal-regulated kinases-1/2. Thus, CRACC is a unique CD2-like receptor which mediates NK cell activation through a SAP-independent extracellular signal-regulated kinase-mediated pathway.

Amino Acid Sequence↗
PubMed2001

A DAP12-mediated pathway regulates expression of CC chemokine receptor 7 and maturation of human dendritic cells.

Gene targeting of the adaptor molecule DAP12 in mice caused abnormal distribution and impaired antigen presentation capacity of dendritic cells (DCs). However, the DAP12-associated receptors expressed on DCs and their functions have not been identified yet. Here we show that the triggering receptor expressed on myeloid cells-2 (TREM-2) is a cell surface receptor on human monocyte-derived DCs, which is associated with DAP12. TREM-2/DAP12 promotes upregulation of CC chemokine receptor 7, partial DC maturation, and DC survival through activation of protein tyrosine kinases and extracellular signal-regulated kinase. In contrast to Toll-like receptor-mediated signaling, TREM2/DAP12 stimulation is independent of nuclear factor-kappaB and p38 stress-activated protein kinase. This novel DC activation pathway may regulate DC homeostasis and amplify DC responses to pathogens, explaining the phenotype observed in DAP12-deficient mice.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Strong enhancement of extremely energetic proton production in central heavy ion collisions at intermediate energy.

The energetic proton emission has been investigated as a function of the reaction centrality for the system (58)Ni + (58)Ni at 30A MeV. Extremely energetic protons (E(NN)(p) > or = 130 MeV) were measured and their multiplicity is found to increase almost quadratically with the number of participant nucleons, thus indicating the onset of a mechanism beyond one- and two-body dynamics.

Journal Article↗
PubMed2001

A cohort study of workers exposed to chloroprene in the department of Isère, France.

A cohort study that comprised 533 men was carried out to evaluate the risk of cancer incidence among workers exposed to chloroprene between 1966 and 1997 in a production plant in Isère (France). The risk of cancer was evaluated for the period 1979-1997 from data recorded by the cancer registry in the department of Isère. Standardised incidence ratios (SIR) were calculated using the whole population of the department as reference. An excess of risk of all malignant neoplasms in the cohort was shown (SIR, 1.26; CI, 0.88-1.77). This excess concerned cancers of the lung (SIR, 1.84; CI, 0.84-3.49) and of the head and neck (SIR, 1.89; CI, 0.87-3.59). Where lung cancer was concerned, there was an increase in risk depending on the length of exposure. This relationship was inverse for the head and neck. The excess of risk of lung cancer was the highest in people not exposed or only slightly exposed. For head and neck cancer, this excess was the highest in people with medium exposure. Our results did not confirm the excess of risk of liver cancer discovered during other cohort studies aiming to evaluate the role of chloroprene. The variations in the excess of the risk of cancer of the lung, head and neck were hardly compatible with a professional risk factor.

Carcinogens↗
PubMed2001

Nuclear fragmentation: sampling the instabilities of binary systems.

We derive stability conditions of asymmetric nuclear matter (ANM) and discuss the relation to mechanical and chemical instabilities of general two-component systems. We show that the chemical instability may appear as an instability of the system against isoscalarlike rather than isovectorlike fluctuations if the interaction between the two constituent species has an attractive character as in the case of ANM. This leads to a new kind of liquid-gas phase transition, of interest for fragmentation experiments with radioactive beams.

Journal Article↗