RESUMO
Recent findings indicate that the microbiome may have significant impact on the development of lung cancer by its effects on inflammation, dysbiosis or genome damage. The aim of this study was to compare the sputum microbiome of lung cancer (LC) patients with the chromosomal aberration (CA) and micronuclei (MN) frequency in peripheral blood lymphocytes. In the study, the taxonomic composition of the sputum microbiome of 66 men with untreated LC were compared with 62 control subjects with respect to CA and MN frequency and centromere fluorescence in situ hybridisation analysis. Results showed a significant increase in CA (4.11 ± 2.48% versus 2.08 ± 1.18%) and MN (1.53 ± 0.67% versus 0.87 ± 0.49%) frequencies, respectively, in LC patients as compared to control subjects. The higher frequency of centromeric positive MN of LC patients was mainly due to aneuploidy. A significant increase in Streptococcus, Bacillus, Gemella and Haemophilus in LC patients was detected, in comparison to the control subjects while 18 bacterial genera were significantly reduced, which indicates a decrease in the beta diversity in the microbiome of LC patients. Although, the CA frequency in LC patients is significantly associated with an increased presence of the genera Bacteroides, Lachnoanaerobaculum, Porphyromonas, Mycoplasma and Fusobacterium in their sputum, and a decrease for the genus Granulicatella after application of false discovery rate correction, significance was not any more present. The decrease of MN frequency of LC patients is significantly associated with an increase in Megasphaera genera and Selenomonas bovis. In conclusion, a significant difference in beta diversity of microbiome between LC and control subjects and association between the sputum microbiome composition and genome damage of LC patients was detected, thus supporting previous studies suggesting an etiological connection between the airway microbiome and LC.
Assuntos
Dano ao DNA , Neoplasias Pulmonares/microbiologia , Linfócitos , Microbiota , Sistema Respiratório/microbiologia , Adulto , Idoso , Aneuploidia , Biodiversidade , Centrômero/genética , Aberrações Cromossômicas/estatística & dados numéricos , DNA Bacteriano , Disbiose/microbiologia , Humanos , Inflamação/microbiologia , Masculino , Micronúcleos com Defeito Cromossômico/estatística & dados numéricos , Pessoa de Meia-Idade , RNA Ribossômico 16S , Escarro/microbiologiaRESUMO
Susceptibility to environmental stressors has been described for fetal and early childhood development. However, the possible susceptibility of the prepubertal period, characterized by the orchestration of the organism towards sexual maturation and adulthood has been poorly investigated and exposure data are scarce. In the current study levels of cadmium (Cd), cotinine and creatinine in urine were analyzed in a subsample 216 children from 12 European countries within the DEMOCOPHES project. The children were divided into six age-sex groups: boys (6-8 years, 9-10 years and 11 years old), and girls (6-7 years, 8-9 years, 10-11 years). The number of subjects per group was between 23 and 53. The cut off values were set at 0.1 µg/L for Cd, and 0.8 µg/L for cotinine defined according to the highest limit of quantification. The levels of Cd and cotinine were adjusted for creatinine level. In the total subsample group, the median level of Cd was 0.180 µg/L (range 0.10-0.69 µg/L), and for cotinine the median wet weight value was 1.50 µg/L (range 0.80-39.91 µg/L). There was no significant difference in creatinine and cotinine levels between genders and age groups. There was a significant correlation between levels of cadmium and creatinine in all children of both genders. This shows that even at such low levels the possible effect of cadmium on kidney function was present and measurable. An increase in Cd levels was evident with age. Cadmium levels were significantly different between 6-7 year old girls, 11 year old boys and 10-11 year old girls. As there was a balanced distribution in the number of subjects from countries included in the study, bias due to data clustering was not probable. The impact of low Cd levels on kidney function and gender differences in Cd levels needs further investigation.
Assuntos
Envelhecimento/urina , Cádmio/urina , Cotinina/urina , Monitoramento Ambiental/métodos , Caracteres Sexuais , Biomarcadores/urina , Criança , Creatinina/urina , Europa (Continente) , Feminino , Humanos , Masculino , Puberdade/urinaRESUMO
Diet has long been known to modify physiology during development and adulthood. However, due to a growing number of manufactured contaminants and additives over the last few decades, diet has increasingly become a source of exposure to chemicals that has been associated with adverse health risks. Sources of food contaminants include the environment, crops treated with agrochemicals, inappropriate storage (e.g., mycotoxins) and migration of xenobiotics from food packaging and food production equipment. Hence, consumers are exposed to a mixture of xenobiotics, some of which are endocrine disruptors (EDs). The complex interactions between immune function and brain development and their orchestration by steroid hormones are insufficiently understood in human populations, and little is known about the impact on immune-brain interactions by transplacental fetal exposure to EDs via maternal diet. To help to identify the key data gaps, this paper aims to present (a) how transplacental EDs modify immune system and brain development, and (b) how these mechanisms may correlate with diseases such as autism and disturbances of lateral brain development. Attention is given to disturbances of the subplate, a transient structure of crucial significance in brain development. Additionally, we describe cutting edge approaches to investigate the developmental neurotoxicity of EDs, such as the application of artificial intelligence and comprehensive modelling. In the future, highly complex investigations will be performed using virtual brain models constructed using sophisticated multi-physics/multi-scale modelling strategies based on patient and synthetic data, which will enable a greater understanding of healthy or disturbed brain development.
Assuntos
Disruptores Endócrinos , Gravidez , Feminino , Humanos , Disruptores Endócrinos/toxicidade , Inteligência Artificial , Mães , Dieta , Troca Materno-FetalRESUMO
An increase in the incidence of breast cancer in women aged<40 years has been reported in recent years. Increased incidence could be partly explained by subtle detection biases, but the role of other risk factors cannot be ruled out. The purpose of the present study was to investigate the changes in temporal trends in breast cancer incidence in European women aged 20-39 years at diagnosis. Age specific breast cancer incidence rates for 17 European Cancer Registries were retrieved for the calendar period 1995-2006. Cancer registries data were pooled to reduce annual fluctuations present in single registries and increase incidence rates stability. Regression models were fitted to the data assuming that the number of cancer cases followed the Poisson distribution. Mean annual changes in the incidence rate (AIC) across the considered time window were calculated. The AIC estimated from all European registries was 1.032 (95% CI=1.019-1.045) and 1.014 (95% CI=1.010-1.018) in women aged 20-29 and 30-39 years old at diagnosis, respectively. The major change was detected among women aged 25-29 years at diagnosis: AIC=1.033 (95% CI=1.020-1.046). The upward trend was not affected when registries with high or low AIC were removed from the analysis (sensitivity analysis). Our findings support the presence of an increase in the incidence of breast cancer in European women in their 20s and 30s during the decade 1995-2006. The interpretation of the observed increase is not straightforward since a number of factors may have affected our results. The estimated annual increase in breast cancer incidence may result in a burden of the disease that is important in terms of public health and deserves further investigation of possible risk factors.
Assuntos
Neoplasias da Mama/epidemiologia , Adulto , Neoplasias da Mama/diagnóstico , Europa (Continente)/epidemiologia , Feminino , Humanos , Incidência , Funções Verossimilhança , Distribuição de Poisson , Análise de Regressão , Sensibilidade e Especificidade , Adulto JovemRESUMO
Male infertility, a condition that has during the last decade raised significant concern, is a diagnostically demanding and socially sensitive topic. The number of unsolved issues on infertility etiology, especially potential environmental causes, in couples demonstrates the need for further investigations into infertility biomarkers. Semen parameters are often insufficient for reliable profiling of male infertility. Thus, this study aims to evaluate for the first time seminal plasma N-glycosylation as a biomarker of environmental exposure in semen samples from 82 normozoospermic men and 84 men with abnormal semen parameters and compare it with genome damage measured by DNA fragmentation. We obtained information about chronic exposure to environmental factors from the self-reported questionnaire, and determined sperm DNA fragmentation by sperm chromatin dispersion, while N-glycans were characterized with liquid chromatography-mass spectrometry (LC-MS). Based on previously published results, ten N-glycans were selected. Results show that the selected seminal plasma N-glycans were significantly associated with smoking, exposure to pesticides, air pollution, agents emitted during photocopying, alcohol consumption, and obesity. Some N-glycans showed a simultaneous association with DNA fragmentation, semen parameters, and environmental stressors. These subgroups of N-glycans are new potential candidates for biomonitoring of exposure to different environmental factors in men with semen abnormalities.
Assuntos
Infertilidade Masculina , Praguicidas , Biomarcadores/análise , Cromatina , Fragmentação do DNA , Exposição Ambiental/efeitos adversos , Humanos , Infertilidade Masculina/genética , Masculino , Praguicidas/análise , Polissacarídeos/análise , Sêmen/química , Análise do Sêmen , Motilidade dos Espermatozoides , EspermatozoidesRESUMO
Large investments by pharmaceutical companies in the development of new antineoplastic drugs have not been resulting in adequate advances of new therapies. Despite the introduction of new methods, technologies, translational medicine and bioinformatics, the usage of collected knowledge is unsatisfactory. In this paper, using examples of pancreatic ductal adenocarcinoma (PaC) and castrate-resistant prostate cancer (CRPC), we proposed a concept showing that, in order to improve applicability of current knowledge in oncology, the re-clustering of clinical and scientific data is crucial. Such an approach, based on systems oncology, would include bridging of data on biomarkers and pathways between different cancer types. Proposed concept would introduce a new matrix, which enables combining of already approved therapies between cancer types. Paper provides a (a) detailed analysis of similarities in mechanisms of etiology and progression between PaC and CRPC, (b) diabetes as common hallmark of both cancer types and (c) knowledge gaps and directions of future investigations. Proposed horizontal and vertical matrix in cancer profiling has potency to improve current antineoplastic therapy efficacy. Systems biology map using Systems Biology Graphical Notation Language is used for summarizing complex interactions and similarities of mechanisms in biology of PaC and CRPC.
Assuntos
Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/análise , Redes Reguladoras de Genes , Terapia de Alvo Molecular , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Humanos , Masculino , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Neoplasias de Próstata Resistentes à Castração/metabolismo , Neoplasias de Próstata Resistentes à Castração/patologia , Transdução de SinaisRESUMO
During the last decade, our knowledge of the mechanisms by which children respond to exposures to physical and chemical agents present in the environment, has significantly increased. Results of recent projects and programmes focused on children's health underline a specific vulnerability of children to environmental genotoxicants. Environmental research on children predominantly investigates the health effects of air pollution while effects from radiation exposure deserve more attention. The main sources of knowledge on genome damage of children exposed to radiation are studies performed after the Chernobyl nuclear plant accident in 1986. The present review presents and discusses data collected from papers analyzing genome damage in children environmentally exposed to ionizing radiation. Overall, the evidence from the studies conducted following the Chernobyl accident, nuclear tests, environmental radiation pollution and indoor accidental contamination reveals consistently increased chromosome aberration and micronuclei frequency in exposed than in referent children. Future research in this area should be focused on studies providing information on: (a) effects on children caused by low doses of radiation; (b) effects on children from combined exposure to low doses of radiation and chemical agents from food, water and air; and (c) specific effects from exposure during early childhood (radioisotopes from water, radon in homes). Special consideration should also be given to a possible impact of a radiochemical environment to the development of an adaptive response for genomic damage. Interactive databases should be developed to provide integration of cytogenetic data, childhood cancer registry data and information on environmental contamination. The overall aim is to introduce timely and efficient preventive measures, by means of a better knowledge of the early and delayed health effects in children resulting from radiation exposure.
Assuntos
Aberrações Cromossômicas/efeitos da radiação , Dano ao DNA , Exposição Ambiental/efeitos adversos , Radiação Ionizante , Acidente Nuclear de Chernobyl , Criança , Relação Dose-Resposta à Radiação , Humanos , Liberação Nociva de RadioativosRESUMO
The living environment is a multilevel physical and chemical xenobiotic complex with potentially mutagenic effects and health risks. In addition to inorganic exposures, all terrestrial and aquatic living forms interact with microbiota as selectively established communities of bacteria, viruses and fungi. Along these lines, the human organism should then be considered a "meta-organism" with complex dynamics of interaction between the environment and microbiome. Bacterial communities within the microbiome, bacteriome, by its mass, symbiotic or competitive position and composition are in a fragile balance with the host organisms and have a crucial impact on their homeostasis. Bacteriome taxonomic composition is modulated by age, sex and host genetic profile and may be changed by adverse environmental exposures and life style factors such as diet or drug intake. A changed and/or misbalanced bacteriome has genotoxic potential with significant impact on the pathogenesis of acute, chronic and neoplastic diseases in the host organism. Bacteria may produce genotoxins, express a variety of pathways in which they generate free radicals or affect DNA repair causing genome damage, cell cycle arrest and apoptosis, modulate immune response and launch carcinogenesis in the host organism. Future investigations should focus on the interplay between exposure to xenobiotics and bacteriome composition, immunomodulation caused by misbalanced bacteriome, impact of the environment on bacteriome composition in children and its lifelong effect on health risks.
Assuntos
Microbiota/genética , Microbiota/fisiologia , Mutagênicos/toxicidade , Animais , Toxinas Bacterianas/genética , Toxinas Bacterianas/toxicidade , Dano ao DNA , Escherichia coli/genética , Escherichia coli/patogenicidade , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/fisiologia , Humanos , Mutação , Neoplasias/etiologia , Neoplasias/genética , Neoplasias/microbiologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/patogenicidade , Salmonella typhi/genética , Salmonella typhi/patogenicidadeRESUMO
Recent publications have highlighted a greater utility of routine blood tests in patients with various cancers than previously assumed. It appears that the neutrophil-to-lymphocyte ratio (NLR) may be a good predictive biomarker for overall survival (OS) and disease-free survival (DFS). Preoperative and postoperative NLR data for patients with head and neck cancers have yet to be established. The aim of this study was to evaluate the preoperative and postoperative NLR in 182 patients with head and neck squamous cell carcinoma and to determine the association of NLR with OS and DFS. The statistical analysis of OS and DFS and their predictors was performed using Kaplan-Meier survival analysis and multivariate Cox proportional hazards regression analysis, with factors including age, sex, alcohol and tobacco use, tumour location, treatment after surgery, and lymphocyte and neutrophil counts. Longer OS was significantly associated with not consuming alcohol, preoperative neutrophil and lymphocyte counts, preoperative NLR, and the difference between the preoperative and postoperative NLR (P=0.016). Longer DFS was significantly associated with not consuming alcohol, preoperative neutrophil and lymphocyte counts, postoperative NLR, and the difference between preoperative and postoperative NLR (P=0.028).
Assuntos
Neutrófilos , Carcinoma de Células Escamosas de Cabeça e Pescoço/sangue , Carcinoma de Células Escamosas de Cabeça e Pescoço/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Feminino , Humanos , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Análise de Sobrevida , Resultado do TratamentoRESUMO
Biological responses to carcinogens from environmental exposure during adulthood are modulated over years or decades. Conversely, during transplacental exposure, the effects on the human foetus change within weeks, intertwining with developmental mechanisms: even short periods of transplacental exposure may be imprinted in the organism for a lifetime. The pathways leading to childhood and juvenile cancers, such as leukaemias, neuroblastoma/brain tumours, hepatoblastoma, and Willm's tumour involve prenatally-induced genomic, epigenomic and/or non-genomic effects caused by xenobiotics. Pregnant women most often live in complex environmental settings that cause transplacental exposure of the foetus to xenobiotic mixtures. Mother-child biomonitoring should integrate the analysis of chemicals/radiation present in the living and workplace environment with relevant risk modulators related to life style. The interdisciplinary approach for transplacental cancer risk assessment in high-pressure areas should be based on an integrated model for mother-child exposure estimation via profiling the exposure level by water quality analysis, usage of emission grids, and land use maps.
Assuntos
Carcinógenos Ambientais/toxicidade , Troca Materno-Fetal , Neoplasias/etiologia , Efeitos Tardios da Exposição Pré-Natal , Poluentes Atmosféricos/toxicidade , Criança , Feminino , Contaminação de Alimentos , Humanos , Praguicidas/toxicidade , Gravidez , Radiação Ionizante , Risco , Caracteres Sexuais , Poluentes da Água/toxicidadeRESUMO
Previous studies have suggested that the frequency of chromosomal aberrations (CAs), but not of sister chromatid exchanges (SCEs), predicts cancer risk. We have further examined this relationship in European cohorts comprising altogether almost 22,000 subjects, in the framework of a European collaborative project (CancerRiskBiomarkers). The present paper gives an overview of some of the results of the project, especially as regards CAs and SCEs. The results confirm that a high level of CAs is associated with an increased risk of cancer and indicate that this association does not depend on the time between CA analysis and cancer detection, i.e., is obviously not explained by undetected cancer. The present evidence indicates that both chromatid-type and chromosome-type CAs predict cancer, even though some data suggest that chromosome-type CAs may have a more pronounced predictive value than chromatid-type CAs. CA frequency appears to predict cancers at various sites, although there seems to be a particular association with gastrointestinal cancers. SCE frequency does not appear to have cancer predictive value, at least partly due to uncontrollable technical variation. A number of genetic polymorphisms of xenobiotic metabolism, DNA repair, and folate metabolism affect the level of CAs and might collectively contribute to the cancer predictivity of CAs. Other factors that may influence the association between CAs and cancer include, e.g., exposure to genotoxic carcinogens and internal generation of genotoxic species. Although the association between CA level and cancer is seen at the group level, an association probably also exists for the individual, although it is not known if an individual approach could be feasible. However, group level evidence should be enough to support the use of CA analysis as a tool in screening programs and prevention policies in occupational and environmental health.
Assuntos
Aberrações Cromossômicas , Neoplasias/epidemiologia , Neoplasias/genética , Troca de Cromátide Irmã , Estudos de Coortes , Europa (Continente) , Marcadores Genéticos , Humanos , Neoplasias/metabolismo , Polimorfismo Genético , Medição de Risco , Xenobióticos/metabolismoRESUMO
DNA methylation is an important mechanism for regulation of gene expression during vertebrate development. 5-azacytidine is used as an experimental tool for demethylation. In this work, a single dose of 5-azacytidine (5 mg/kg body weight) was administered to rats at different stages of development. After 5-azacytidine administration on the first or third day of pregnancy, no changes were detected. After administration on the fourth day of pregnancy or later, a reduction in growth was observed. After treatment on day five and on any other day till day eleven of pregnancy, no living fetuses were found. Of those treated on day twelve, 24% of fetuses survived, but forelimb and hindlimb malformations were present. Administered on day thirteen, 5-azacytidine did not interfere with survival, but malformations were still present. From day fourteen on, 5-azacytidine caused no gross external malformations. Placentas were also influenced by 5-azacytidine. They were significantly smaller and histological evaluation showed the labyrinthine part to be severely reduced. In contrast, trophoblast giant cells were more abundant than in controls.
Assuntos
Azacitidina/toxicidade , Metilação de DNA/efeitos dos fármacos , Embrião de Mamíferos/efeitos dos fármacos , Placenta/efeitos dos fármacos , Anormalidades Induzidas por Medicamentos/etiologia , Anormalidades Induzidas por Medicamentos/metabolismo , Animais , Embrião de Mamíferos/patologia , Feminino , Idade Gestacional , Placenta/patologia , Gravidez , Ratos , Ratos Endogâmicos F344RESUMO
The small magnocellular group located within the rostrolateral extension of the basal forebrain was named and described as the nucleus subputaminalis in the human and chimpanzee brain by Ayala. Analysis of cytoarchitectonic and cytochemical characteristics of this cell group has been largely disregarded in both classical and more current studies. We examined the nucleus subputaminalis in 33 neurologically normal subjects (ranging from 15 weeks of gestation to 71 years-of-age) by using Nissl staining, choline acetyltransferase immunohistochemistry, acetyl cholinesterase histochemistry and nerve growth factor receptor immunocytochemistry. In addition, we applied reduced nicotinamide adenine dinucleotide phosphate-diaphorase histochemistry and calbindin-D28k immunocytochemistry in three neurologically normal subjects. At the most rostrolateral levels we describe the previously poorly characterized component of the lateral (periputaminal) subdivision of the subputaminal nucleus, which may be human specific since it is not described in non-human primates. Moreover, we find the human subputaminal nucleus best developed at the anterointermediate level, which is the part of the basal nucleus that is usually much smaller or missing in monkeys. The location of subputaminal cholinergic neurons within the frontal lobe, the ascension of their fibers through the external capsule towards the inferior frontal gyrus, the larger size of the subputaminal nucleus on the left side at the most rostral and anterointermediate levels and the most protracted development among all magnocellular aggregations within the basal forebrain strongly suggest that they may be connected with the cortical speech area. These findings give rise to many hypotheses about the possible role of the subputaminal nucleus in various neurodegenerative, neurological and psychiatric disorders, particularly Alzheimer's disease and primary progressive aphasia. Therefore, future studies on the basal forebrain should more carefully investigate this part of the basal nucleus.
Assuntos
Doença de Alzheimer/fisiopatologia , Fala/fisiologia , Substância Inominada/citologia , Substância Inominada/fisiologia , Adolescente , Adulto , Idoso , Afasia/fisiopatologia , Núcleo Arqueado do Hipotálamo/citologia , Calbindina 1 , Calbindinas , Criança , Pré-Escolar , Colina O-Acetiltransferase/análise , Fibras Colinérgicas/química , Fibras Colinérgicas/enzimologia , Feminino , Feto/química , Feto/enzimologia , Humanos , Recém-Nascido , Masculino , Corpos Mamilares/citologia , Pessoa de Meia-Idade , NADPH Desidrogenase/análise , Proteínas do Tecido Nervoso/análise , Quiasma Óptico/citologia , Receptores de Fator de Crescimento Neural/fisiologia , Proteína G de Ligação ao Cálcio S100/análiseRESUMO
The application of ionizing radiation in industry for nondestructive testing entails a specific framework of working conditions that include field work, facilities with different radioactive sources, maintenance thereof without halting production, use of nonionizing radiation, and exposure to chemical agents. The present study gives an estimation of recent genome damage in two groups of subjects using chromosome aberration assay and micronucleus assay. The first group was exposed to (192)Ir and the second was simultaneously exposed to (192)Ir and ultrasound. The results show that both groups had higher values of chromosome aberrations and micronucleus frequency than controls. The group of examinees exposed both to (192)Ir and ultrasound had significantly more chromatid breaks, acentric fragments, and dicentric chromosomes, and had a significantly higher frequency of micronuclei than subjects exposed to (192)Ir only. The study suggests that the detected differences in the genome damage may be attributed to the action of ultrasound. This study confirms the dosimetry data for ionizing radiation, which indicate that the methods used in industrial radiography and the usage of nonionizing radiation entail an increased health risk. In the absence of personal dosimeters for nonionizing radiation and chemical agents, biomonitoring provides reliable parameters for estimation of genome damage and may lead to improvements in working conditions and radiation safety programs.
Assuntos
Aberrações Cromossômicas , Dano ao DNA/efeitos da radiação , Testes para Micronúcleos , Exposição Ocupacional , Ultrassom/efeitos adversos , Adulto , Humanos , Radioisótopos de Irídio , Masculino , Distribuição de Poisson , Radiação Ionizante , Fumar , Fatores de TempoRESUMO
Micronucleus (MN) expression in peripheral blood lymphocytes is well established as a standard method for monitoring chromosome damage in human populations. The first results of an analysis of pooled data from laboratories using the cytokinesis-block micronucleus (CBMN) assay and participating in the HUMN (HUman MicroNucleus project) international collaborative study are presented. The effects of laboratory protocol, scoring criteria, and host factors on baseline micronucleated binucleate cell (MNC) frequency are evaluated, and a reference range of "normal" values against which future studies may be compared is provided. Primary data from historical records were submitted by 25 laboratories distributed in 16 countries. This resulted in a database of nearly 7000 subjects. Potentially significant differences were present in the methods used by participating laboratories, such as in the type of culture medium, the concentration of cytochalasin-B, the percentage of fetal calf serum, and in the culture method. Differences in criteria for scoring micronuclei were also evident. The overall median MNC frequency in nonexposed (i.e., normal) subjects was 6.5 per thousand and the interquartile range was between 3 and 12 per thousand. An increase in MNC frequency with age was evident in all but two laboratories. The effect of gender, although not so evident in all databases, was also present, with females having a 19% higher level of MNC frequency (95% confidence interval: 14-24%). Statistical analyses were performed using random-effects models for correlated data. Our best model, which included exposure to genotoxic factors, host factors, methods, and scoring criteria, explained 75% of the total variance, with the largest contribution attributable to laboratory methods.
Assuntos
Bases de Dados Factuais , Linfócitos/patologia , Programas de Rastreamento/normas , Testes para Micronúcleos/normas , Adolescente , Adulto , Distribuição por Idade , Fatores Etários , Artefatos , Divisão Celular/genética , Criança , Interpretação Estatística de Dados , Bases de Dados Factuais/estatística & dados numéricos , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Programas de Rastreamento/estatística & dados numéricos , Testes para Micronúcleos/métodos , Testes para Micronúcleos/estatística & dados numéricos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Projetos de Pesquisa/normas , Distribuição por Sexo , Fatores Sexuais , Inquéritos e QuestionáriosRESUMO
The earliest somatostatin-immunoreactive (SS-Ir) perikarya of the human fetal frontal cortex appear in the transient subplate zone at 22 weeks of gestation. Around 32 weeks of gestation there is an increase in the number of SS-Ir neurons at the interface between the subplate zone and the cortical plate. The newborn-cortex shows decline in the overall number of SS-Ir neurons parallel to the appearance of SS-Ir neurons in the superficial layers. In conclusion, the subplate neurons are the source of the earliest peptidergic activity in the cortex. Furthermore, the distribution and density of peptidergic neurons undergo significant reorganization during the perinatal development.
Assuntos
Córtex Cerebral/crescimento & desenvolvimento , Neurônios/metabolismo , Somatostatina/metabolismo , Córtex Cerebral/citologia , Córtex Cerebral/imunologia , Feminino , Feto/metabolismo , Idade Gestacional , Humanos , Neurônios/imunologia , Fenótipo , Gravidez , Somatostatina/imunologiaRESUMO
The mutagenic effects of vinyl chloride monomer in man were studied in the lymphocyte culture with 3 methods: the chromosome aberration assay, the micronucleus assay and the sister-chromatid exchange method. Compared with control, values obtained by these tests are increased in workers occupationally exposed to vinyl chloride. In relation to non-smokers, smokers exposed to vinyl chloride show significant increases in sister-chromatid exchange frequencies. The problem of correlating the results of the chromosome aberration assay with micronucleus and sister-chromatid exchange frequencies is discussed.
Assuntos
Mutagênicos , Cloreto de Vinil/toxicidade , Adulto , Aberrações Cromossômicas , Humanos , Linfócitos/efeitos dos fármacos , Masculino , Micronúcleos com Defeito Cromossômico/efeitos dos fármacos , Pessoa de Meia-Idade , Exposição Ocupacional , Troca de Cromátide Irmã/efeitos dos fármacos , Fumar/genéticaRESUMO
A group of 67 workers occupationally exposed to VCM was examined for the presence and distribution of breaks along the chromosomal length. Breaks induced by VCM are not randomly distributed as had been expected in a normal population. According to our results there exist highly sensitive and highly resistant locations along the chromosomes to the actions of VCM. The link between the highly sensitive segments of chromosomes, fragile sites and the activation of oncogenes is discussed.
Assuntos
Cromossomos/efeitos dos fármacos , Cloreto de Vinil/toxicidade , Compostos de Vinila/toxicidade , Células Cultivadas , Distribuição de Qui-Quadrado , Exposição Ambiental , Humanos , Linfócitos/efeitos dos fármacos , Linfócitos/ultraestruturaRESUMO
Human whole-blood samples were exposed to continuous microwave radiation, frequency 7.7 GHz, power density 0.5, 10 and 30 mW/cm2 for 10, 30 and 60 min. A correlation between specific chromosomal aberrations and the incidence of micronuclei after in vitro exposure was observed. In all experimental conditions, the frequency of all types of chromosomal aberrations was significantly higher than in the control samples. In the irradiated samples the presence of dicentric and ring chromosomes was established. The incidence of micronuclei was also higher in the exposed samples. The results of the structural chromosome aberration test and of the micronucleus test were comparatively analyzed. The values obtained showed a positive correlation between micronuclei and specific chromosomal aberrations (acentric fragments and dicentric chromosomes). The results of the study indicate that microwave radiation causes changes in the genome of somatic human cells and that the applied tests are equally sensitive for the detection of the genotoxicity of microwaves.
Assuntos
Aberrações Cromossômicas , Linfócitos/efeitos da radiação , Micronúcleos com Defeito Cromossômico/efeitos da radiação , Micro-Ondas , Células Cultivadas , Relação Dose-Resposta à Radiação , Humanos , Cariotipagem , Testes para MicronúcleosRESUMO
Cytogenetic analysis was carried out in 41 workers prior to and following regular maintenance work in a nuclear power plant. Although film dosimetry did not show the maximal annual permitted dose in any of the examined subjects, cytogenetic analysis carried out following the work detected dicentric chromosomes in peripheral blood lymphocytes of 20 workers. According to our findings smoking habits and previous exposure to ionizing radiation had no effect on the increased number of chromosomal aberrations.