RESUMO
OBJECTIVES: The assessment of pulmonary single-breath diffusing capacity is a frequently performed diagnostic procedure and considered as an important tool in medical surveillance examinations of pulmonary diseases.The aim of this study was to establish reference equations for pulmonary single-breath diffusing capacity parameters in a representative adult-population across a wide age range and to compare the normative values from this sample with previous ones. METHODS: Diffusing capacity measurement was carried out in 3566 participants (1811 males) of a cross-sectional, population-based survey ("Study of Health in Pomerania - SHIP"). RESULTS: Individuals with cardiopulmonary disorders and current smoking habits were excluded, resulting in 1786 healthy individuals (923 males), aged 20â-â84 years. Prediction equations for both sexes were established by quantile regression analyses, taking into consideration the influence of age, height, weight and former smoking. CONCLUSION: The study provides a novel set of prediction equations for pulmonary single-breath diffusing capacity in an adult Caucasian population. The results are comparable to previously reported equations, underline their importance and draw attention to the need for up-to-date reference equations that adequately take into account both the subjects' origin, age, anthropometric characteristics and the equipment used.
Assuntos
Pneumopatias , Capacidade de Difusão Pulmonar , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Fumar , Adulto JovemRESUMO
Idiopathic pulmonary fibrosis (IPF) is a severe and often fatal disease. Diagnosis of IPF requires considerable expertise and experience. Since publication of the international IPF guideline in the year 2011 and Update 2018 several studies and technical advances occurred, which made a new assessment of the diagnostic process mandatory. In view of the antifibrotic drugs which have been approved for the treatment of IPF patients, the goal of this guideline is to foster early, confident and effective diagnosis of IPF. The guideline focusses on the typical clinical setting of an IPF patient and provides tools to exclude known causes of interstitial lung disease including standardised questionnaires, serologic testing and cellular analysis of bronchoalveolar lavage. High resolution computed tomography remains crucial in the diagnostic work-up.âIf it is necessary to obtain specimen for histology transbronchial lung cryobiopsy is the primary approach, while surgical lung biopsy is reserved for patients who are fit for it and in whom bronchoscopic diagnosis did not provide the information needed. Despite considerable progress, IPF remains a diagnosis of exclusion and multidisciplinary discussion remains the golden standard of diagnosis.
Assuntos
Fibrose Pulmonar Idiopática/diagnóstico , Fibrose Pulmonar Idiopática/terapia , Pulmão/diagnóstico por imagem , Guias de Prática Clínica como Assunto , Biópsia , Humanos , Fibrose Pulmonar Idiopática/patologia , Pulmão/patologia , Doenças Pulmonares Intersticiais , Tomografia Computadorizada por Raios XRESUMO
Peak oxygen uptake (VO2peak) is commonly indexed by total body weight (TBW) to determine cardiopulmonary fitness (CPF). This approach may lead to misinterpretation, particularly in obese subjects. We investigated the normalization of VO2peak by different body composition markers. We analyzed combined data of 3848 subjects (1914 women; 49.7%), aged 20-90, from two independent cohorts of the population-based Study of Health in Pomerania (SHIP-2 and SHIP-TREND). VO2peak was assessed by cardiopulmonary exercise testing. Body cell mass (BCM), fat-free mass (FFM), and fat mass (FM) were determined by bioelectrical impedance analysis. The suitability of the different markers as a normalization variable was evaluated by taking into account correlation coefficients (r) and intercept (α-coefficient) values from linear regression models. A combination of high r and low α values was considered as preferable for normalization purposes. BCM was the best normalization variable for VO2peak (r = .72; P ≤ .001; α-coefficient = 63.3 mL/min; 95% confidence interval [CI]: 3.48-123) followed by FFM (r = .63; P ≤ .001; α-coefficient = 19.6 mL/min; 95% CI: -57.9-97.0). On the other hand, a much weaker correlation and a markedly higher intercept were found for TBW (r = .42; P ≤ .001; α-coefficient = 579 mL/min; 95% CI: 483 to 675). Likewise, FM was also identified as a poor normalization variable (r = .10; P ≤ .001; α-coefficient = 2133; 95% CI: 2074-2191). Sex-stratified analyses confirmed the above order for the different normalization variables. Our results suggest that BCM, followed by FFM, might be the most appropriate marker for the normalization of VO2peak when comparing CPF between subjects with different body shape.
Assuntos
Composição Corporal , Peso Corporal , Aptidão Cardiorrespiratória , Consumo de Oxigênio , Adulto , Idoso , Idoso de 80 Anos ou mais , Teste de Esforço , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
This document replaces the DGP recommendations published in 1998 and 2013. Based on recent studies and a consensus conference, the indications, choice and performance of the adequate exercise testing method and its necessary technical and staffing setting are discussed. Detailed recommendations are provided: for blood gas analysis and right heart catheterization during exercise, walk tests, spiroergometry, and stress echocardiography. The correct use of different exercise tests is discussed for specific situations in respiratory medicine: exercise induced asthma, obesity, monitoring of rehabilitation or therapeutical interventions, preoperative risk stratification, and evaluation in occupational medicine.
Assuntos
Teste de Esforço/normas , Guias de Prática Clínica como Assunto , Pneumologia/normas , Testes de Função Respiratória/normas , Espirometria/normas , Alemanha , Humanos , Medicina do TrabalhoRESUMO
The increasing importance of intensive care medicine including mechanical ventilation has been accompanied by the demand of weaning opportunities for patients undergoing prolonged mechanical ventilation. Consequently, specialised clinical institutions, focusing on the weaning from mechanical ventilation, have been established since the 1980âs.The present article illustrates the structural development and results of such a specialised institution at the University Medicine Greifswald, using data of 616 patients collected within the past ten years (2006â-â2015). Across the years, a shift in the underlying disease leading to mechanical ventilation can be found, with rising numbers of patients suffering from pneumonia/sepsis and declining numbers of patients who underwent cardiac surgery in advance. The days with mechanical ventilation outside (pâ=â0.004) and within the investigated institution (pâ=â0.02) are significantly declining. The percentage of successfully weaned patients increased from 62.7â% (2006â-â2010) to 77.3â% (2011â-â2015), pâ<â0.001.âConsecutively, the percentage of patients who remained mechanically ventilated decreased from 16.4â% to 9.6â% (pâ<â0.001) and the share of in-hospital deceased patients significantly declined from 20.9â% to 13.0â% (pâ<â0.001). Furthermore, the one-year-survival after hospital discharge in successful weaned patients was 72 percent. The present data, collected at the University Medicine Greifswald are quite comparable to data of other German institutions that are specialised on weaning from mechanical ventilation.
Assuntos
Unidades Hospitalares/organização & administração , Hospitais Universitários/organização & administração , Unidades de Terapia Intensiva/organização & administração , Assistência de Longa Duração/organização & administração , Pneumonia/terapia , Sepse/terapia , Desmame do Respirador/métodos , Idoso , Feminino , Alemanha , Unidades Hospitalares/tendências , Hospitais Universitários/tendências , Humanos , Unidades de Terapia Intensiva/tendências , Assistência de Longa Duração/tendências , Masculino , Pessoa de Meia-Idade , Pneumonia/mortalidade , Sepse/mortalidade , Taxa de Sobrevida/tendências , Desmame do Respirador/tendênciasRESUMO
Investigating reasons for differing life expectancy and prevalence of cardiovascular risk factors between old and new states of the Federal Republic of Germany an epidemiological study in Western Pomeraniaâ-âthe population-based project Study of Health in Pomerania (SHIP)â-âwas planned.Prevalence and incidence of common risk factors, subclinical disorders and clinical diseases have been assessed since 1997 in five-year intervals. The third follow up (SHIP-3) was assessed between 2014 and 2016. In addition, an independent representative population sample was investigated between 2008â-â2012 (SHIP-TREND). Recently, the first follow up of this cohort has been started (SHIP-TREND-1). This paper reports the methodological approaches for detecting pneumological relevant morbidities in this population-based study. It aims to offer insights for potential cooperation with interested research groups.
Assuntos
Doenças Cardiovasculares/mortalidade , Nível de Saúde , Expectativa de Vida , Pneumopatias/mortalidade , Projetos de Pesquisa , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Alemanha/epidemiologia , Humanos , Pneumopatias/diagnóstico , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Prevalência , Fatores de Risco , Taxa de Sobrevida , Adulto JovemRESUMO
Lower muscle strength in midlife predicts disability and mortality in later life. Blood-borne factors, including growth differentiation factor 11 (GDF11), have been linked to muscle regeneration in animal models. We aimed to identify gene transcripts associated with muscle strength in adults. Meta-analysis of whole blood gene expression (overall 17,534 unique genes measured by microarray) and hand-grip strength in four independent cohorts (n = 7,781, ages: 20-104 yr, weighted mean = 56), adjusted for age, sex, height, weight, and leukocyte subtypes. Separate analyses were performed in subsets (older/younger than 60, men/women). Expression levels of 221 genes were associated with strength after adjustment for cofactors and for multiple statistical testing, including ALAS2 (rate-limiting enzyme in heme synthesis), PRF1 (perforin, a cytotoxic protein associated with inflammation), IGF1R, and IGF2BP2 (both insulin like growth factor related). We identified statistical enrichment for hemoglobin biosynthesis, innate immune activation, and the stress response. Ten genes were associated only in younger individuals, four in men only and one in women only. For example, PIK3R2 (a negative regulator of PI3K/AKT growth pathway) was negatively associated with muscle strength in younger (<60 yr) individuals but not older (≥ 60 yr). We also show that 115 genes (52%) have not previously been linked to muscle in NCBI PubMed abstracts. This first large-scale transcriptome study of muscle strength in human adults confirmed associations with known pathways and provides new evidence for over half of the genes identified. There may be age- and sex-specific gene expression signatures in blood for muscle strength.
Assuntos
Envelhecimento/fisiologia , Coração/fisiologia , Força Muscular/genética , RNA Mensageiro/genética , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Ontologia Genética , Humanos , Joelho/fisiologia , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Reprodutibilidade dos Testes , Caracteres Sexuais , Adulto JovemRESUMO
Vitamin D has an important role in calcium homeostasis and is known to have various health-promoting effects. Moreover, potential interactions between vitamin D and physical activity have been suggested. This study aims to investigate the relationship between 25-hydroxyvitamin D (25(OH)D) and exercise capacity quantified by cardiopulmonary exercise testing (CPET). For this, 1377 participants from the Study of Health in Pomerania (SHIP-1) and 750 participants from the independent SHIP-TREND cohort were investigated. Standardised incremental exercise tests on a cycle ergometer were performed to assess exercise capacity by VO2 at anaerobic threshold, peakVO2, O2 pulse and peak power output. Serum 25(OH)D levels were measured by an automated chemiluminescence immunoassay. In SHIP-1, 25(OH)D levels were positively associated with all considered parameters of cardiopulmonary exercise capacity. Subjects with high 25(OH)D levels (4th quartile) showed an up to 25% higher exercise capacity compared with subjects with low 25(OH)D levels (1st quartile). All associations were replicated in the independent SHIP-TREND cohort and were independent of age, sex, season and other interfering factors. In conclusion, significant positive associations between 25(OH)D and parameters of CPET were detected in two large cohorts of healthy adults.
Assuntos
Vitamina D/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Sistema Cardiovascular/metabolismo , Estudos de Coortes , Estudos Transversais , Exercício Físico , Teste de Esforço , Feminino , Frequência Cardíaca , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Atividade Motora , Análise Multivariada , Consumo de Oxigênio , Sistema Respiratório/metabolismo , Fatores SocioeconômicosRESUMO
Here we study the optimum efficiency of the excitation of maximum quantum (MaxQ) coherence using analytical and numerical methods based on optimal control theory. The theoretical limit of the achievable MaxQ amplitude and the minimum time to achieve this limit are explored for a set of model systems consisting of up to five coupled spins. In addition to arbitrary pulse shapes, two simple pulse sequence families of practical interest are considered in the optimizations. Compared to conventional approaches, substantial gains were found both in terms of the achieved MaxQ amplitude and in pulse sequence durations. For a model system, theoretically predicted gains of a factor of three compared to the conventional pulse sequence were experimentally demonstrated. Motivated by the numerical results, also two novel analytical transfer schemes were found: Compared to conventional approaches based on non-selective pulses and delays, double-quantum coherence in two-spin systems can be created twice as fast using isotropic mixing and hard spin-selective pulses. Also it is proved that in a chain of three weakly coupled spins with the same coupling constants, triple-quantum coherence can be created in a time-optimal fashion using so-called geodesic pulses.
RESUMO
We show to which extent the signal to noise ratio per unit time of a spin 1/2 particle can be maximized. We consider a cyclic repetition of experiments made of a measurement followed by a radio-frequency magnetic field excitation of the system, in the case of unbounded amplitude. In the periodic regime, the objective of the control problem is to design the initial state of the system and the pulse sequence which leads to the best signal to noise performance. We focus on two specific issues relevant in nuclear magnetic resonance, the crusher gradient and the radiation damping cases. Optimal control techniques are used to solve this non-standard control problem. We discuss the optimality of the Ernst angle solution, which is commonly applied in spectroscopic and medical imaging applications. In the radiation damping situation, we show that in some cases, the optimal solution differs from the Ernst one.
RESUMO
Spirometry is a highly standardized method which allows to measure the forced vital capacity (FVC) with high precision and reproducibility. In patients with IPF FVC is directly linked to the disease process which is characterized by scaring of alveoli and shrinkage of the lungs. Consequently, there is ample evidence form clinical studies that the decline of FVC over time is consistently associated with mortality in IPF. As for the first time effective drugs for the treatment of IPF are available it becomes obvious that in studies which could demonstrate that the drug reduces FVC decline, a numerical effect on mortality was also observed, while in one study where a significant effect on FVC decline was missed, there was also no change in mortality. Based on these studies FVC decline is a validated surrogate of mortality in IPF. It is concluded that FVC decline is not only accepted as an endpoint of clinical treatment trials in IPF but is also valid as a patient related outcome parameter which should be considered for the assessment of the efficacy of an IPF drug.
Assuntos
Fibrose Pulmonar Idiopática/diagnóstico , Fibrose Pulmonar Idiopática/mortalidade , Guias de Prática Clínica como Assunto , Espirometria/estatística & dados numéricos , Espirometria/normas , Capacidade Vital , Medicina Baseada em Evidências , Alemanha , Humanos , Incidência , Prognóstico , Reprodutibilidade dos Testes , Medição de Risco/métodos , Sensibilidade e Especificidade , Espirometria/métodos , Taxa de SobrevidaRESUMO
Dyspnea represents one of the most frequent and heterogeneous symptoms. The term dyspnea describes the subjective perception of an inadequate effort to breathe. In general, acute and chronic forms have to be differentiated. Due to its prognostic implications a structured work-up to find the correct diagnosis is of great importance. Depending on the condition of the patient, simple algorithms including biomarkers, an electrocardiogram, echocardiography and other imaging procedures are used when needed. Especially in its acute appearance life-threatening situations, such as myocardial ischemia, heart failure, pulmonary embolism and pneumothorax have to be rapidly and effectively excluded in the differential diagnostics. In contrast, the underlying diseases in chronic dyspnea are bronchial asthma, chronic obstructive airway diseases, heart failure and a combination of obesity and deconditioning in up to 85 % of all cases. The differential diagnosis needs a structured approach including anamnestic and medical technical methods, aiming an efficient differentiation of cardiac and pulmonary causes. As a high number of patients suffer from more than one significant disease, the differential diagnostic assessment needs to be focused on the assessment of the predominant cause of the dyspnea. For this purpose, exercise tests provide helpful algorithms to answer this question.
Assuntos
Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/diagnóstico , Dispneia/diagnóstico , Dispneia/etiologia , Pneumopatias/complicações , Pneumopatias/diagnóstico , Cuidados Críticos/métodos , Diagnóstico Diferencial , Humanos , Avaliação de Sintomas/métodosRESUMO
PURPOSE: For classical Hodgkin lymphoma (HL), migrant studies could elucidate contributions of environmental factors (including Epstein-Barr virus (EBV)) to the lower rates in non-whites. Given the well-described etiologic complexity of HL, this research requires a large, immigrant population, such as California Hispanics. METHODS: With 1988-2004 California Cancer Registry data (2,595 Hispanic, 8,637 white HL cases) and tumor cell EBV status on a subset (218 Hispanics, 656 whites), we calculated ethnicity- and nativity-specific HL incidence rates simultaneously by age, sex, and histologic subtype, and tumor cell EBV prevalence. RESULTS: Compared with white rates, Hispanic HL rates were lower overall (70 %) and for nodular sclerosis HL, particularly among young adults (60-65 % for females). However, they were higher among children (200 %) and older adults, and for mixed cellularity HL. Compared with rates in foreign-born Hispanics, rates in US-born Hispanics were higher among young adults (>threefold in females), lower for children and adults over age 70, and consistently intermediate compared with rates in whites. EBV tumor prevalence was 67, 32, and 23 % among foreign-born Hispanics, US-born Hispanics, and whites, respectively, although with variation by age, sex, and histology. CONCLUSIONS: Findings strongly implicate environmental influences, such as nativity-related sociodemographic differences, on HL occurrence. In addition, lower young adult rates and higher EBV prevalence in US-born Hispanics than in whites raise questions about the duration/extent of environmental change for affecting HL rates and also point to ethnic differences in genetic susceptibility. Lesser variation in mixed cellularity HL rates and greater variation in rates for females across groups suggest less modifiable factors interacting with environmental influences.
Assuntos
Infecções por Vírus Epstein-Barr/epidemiologia , Herpesvirus Humano 4/isolamento & purificação , Hispânico ou Latino/estatística & dados numéricos , Doença de Hodgkin/epidemiologia , Adolescente , Adulto , Idoso , California/epidemiologia , Criança , Pré-Escolar , Infecções por Vírus Epstein-Barr/etnologia , Infecções por Vírus Epstein-Barr/virologia , Feminino , Doença de Hodgkin/etnologia , Doença de Hodgkin/virologia , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Prevalência , Sistema de Registros , Fatores de Risco , População Branca/estatística & dados numéricos , Adulto JovemRESUMO
Hyperpolarization of [1-13C]pyruvate in solution allows real-time measurement of uptake and metabolism using MR spectroscopic methods. After injection and perfusion, pyruvate is taken up by the cells and enzymatically metabolized into downstream metabolites such as lactate, alanine, and bicarbonate. In this work, we present comprehensive methods for the quantification and interpretation of hyperpolarized 13C metabolite signals. First, a time-domain spectral fitting method is described for the decomposition of FID signals into their metabolic constituents. For this purpose, the required chemical shift frequencies are automatically estimated using a matching pursuit algorithm. Second, a time-discretized formulation of the two-site exchange kinetic model is used to quantify metabolite signal dynamics by two characteristic rate constants in the form of (i) an apparent build-up rate (quantifying the build-up of downstream metabolites from the pyruvate substrate) and (ii) an effective decay rate (summarizing signal depletion due to repetitive excitation, T1-relaxation and backward conversion). The presented spectral and kinetic quantification were experimentally verified in vitro and in vivo using hyperpolarized [1-13C]pyruvate. Using temporally resolved IDEAL spiral CSI, spatially resolved apparent rate constant maps are also extracted. In comparison to single metabolite images, apparent build-up rate constant maps provide improved contrast by emphasizing metabolically active tissues (e.g. tumors) and suppression of high perfusion regions with low conversion (e.g. blood vessels). Apparent build-up rate constant mapping provides a novel quantitative image contrast for the characterization of metabolic activity. Its possible implementation as a quantitative standard will be subject to further studies.
Assuntos
Algoritmos , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13/métodos , Piruvatos/análise , Animais , Feminino , Humanos , Cinética , L-Lactato Desidrogenase/metabolismo , Análise dos Mínimos Quadrados , Células MCF-7/química , Neoplasias Mamárias Experimentais/química , Modelos Químicos , Ratos Endogâmicos F344 , Razão Sinal-Ruído , Esferoides Celulares , Suspensões , Fatores de TempoRESUMO
Previous studies indicate that physical performance, being a relevant prognostic parameter for cardiovascular events and mortality, decreases with age. Thus, the maintenance and restoration of physical performance as part of a rehabilitation program is of great interest. In the present study, 35 physically active participants, aged 58â-â78 years, were investigated by cardiopulmonary exercise testing. In comparison to matched participants drawn from an epidemiological study, there was no significant difference in performance g between the two groups. Additionally, oxygen kineticswere incrementally measured in order to evaluate a fairly simple procedure for determining fitness under activities of daily life. Surprisingly, this method did not reveal any clinically relevant association between oxygen kinetics and physical fitness.
Assuntos
Teste de Esforço/estatística & dados numéricos , Consumo de Oxigênio/fisiologia , Condicionamento Físico Humano/estatística & dados numéricos , Aptidão Física/fisiologia , Idoso , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Valores de ReferênciaRESUMO
BACKGROUND: In clinical practice, oxygen saturation as measured by photoplethysmography and arterial oxygen tension as determined by blood gas analysis are the parameters used frequently to estimate the oxygen status of a patient. Additionally, the cardiac output CO and the arterial oxygen content CaO2 are critical for the delivery of oxygen DO2 to organs and tissues. So far, CaO2 reference values published by Mertzlufft and Zander (1984) and Siggaard-Andersen (1990) are widely used. The aim of the present study was to reevaluate previously published results using the results of a population-based study. Furthermore, the impact of smoking on CaO2 will be assessed. PATIENTS AND METHODS: Data of 1018 volunteers from the Study of Health in Pomerania (SHIP) were analyzed. CaO2 was calculated from blood gas analysis of capillary blood obtained from a hyperemised ear lobe. Reference value equations controlled for sex, age and smoking were derived with quantile regression analysis and fractional polynomials. RESULTS: Lower limits of normal (LLN) decline with age. Current smoking has no significant influence on LLN for CaO2. CONCLUSION: Sex, age and smoking-specific normal values can be calculated using the current equations.
Assuntos
Envelhecimento/metabolismo , Artérias/metabolismo , Oximetria/estatística & dados numéricos , Oximetria/normas , Oxigênio/sangue , Fumar/sangue , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Simulação por Computador , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Distribuição por SexoRESUMO
BACKGROUND: The etiology of Hodgkin lymphoma (HL) remains incompletely characterized. Studies of the association between smoking and HL have yielded ambiguous results, possibly due to differences between HL subtypes. PATIENTS AND METHODS: Through the InterLymph Consortium, 12 case-control studies regarding cigarette smoking and HL were identified. Pooled analyses on the association between smoking and HL stratified by tumor histology and Epstein-Barr virus (EBV) status were conducted using random effects models adjusted for confounders. Analyses included 3335 HL cases and 14 278 controls. RESULTS: Overall, 54.5% of cases and 57.4% of controls were ever cigarette smokers. Compared with never smokers, ever smokers had an odds ratio (OR) of HL of 1.10 [95% confidence interval (CI) 1.01-1.21]. This increased risk reflected associations with mixed cellularity cHL (OR = 1.60, 95% CI 1.29-1.99) and EBV-positive cHL (OR = 1.81, 95% CI 1.27-2.56) among current smokers, whereas risk of nodular sclerosis (OR = 1.09, 95% CI 0.90-1.32) and EBV-negative HL (OR = 1.02, 95% CI 0.72-1.44) was not increased. CONCLUSION: These results support the notion of etiologic heterogeneity between HL subtypes, highlighting the need for HL stratification in future studies. Even if not relevant to all subtypes, our study emphasizes that cigarette smoking should be added to the few modifiable HL risk factors identified.
Assuntos
Infecções por Vírus Epstein-Barr/epidemiologia , Doença de Hodgkin/epidemiologia , Fumar/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Infecções por Vírus Epstein-Barr/complicações , Feminino , Herpesvirus Humano 4/isolamento & purificação , Doença de Hodgkin/induzido quimicamente , Humanos , Masculino , Pessoa de Meia-Idade , Risco , Fatores de Risco , Fumar/efeitos adversos , Classe Social , Tabagismo/complicações , Tabagismo/epidemiologia , Adulto JovemRESUMO
Recent large-scale mutagenesis screens have made the zebrafish the first vertebrate organism to allow a forward genetic approach to the discovery of developmental control genes. Mutations can be cloned positionally, or placed on a simple sequence length polymorphism (SSLP) map to match them with mapped candidate genes and expressed sequence tags (ESTs). To facilitate the mapping of candidate genes and to increase the density of markers available for positional cloning, we have created a radiation hybrid (RH) map of the zebrafish genome. This technique is based on somatic cell hybrid lines produced by fusion of lethally irradiated cells of the species of interest with a rodent cell line. Random fragments of the donor chromosomes are integrated into recipient chromosomes or retained as separate minichromosomes. The radiation-induced breakpoints can be used for mapping in a manner analogous to genetic mapping, but at higher resolution and without a need for polymorphism. Genome-wide maps exist for the human, based on three RH panels of different resolutions, as well as for the dog, rat and mouse. For our map of the zebrafish genome, we used an existing RH panel and 1,451 sequence tagged site (STS) markers, including SSLPs, cloned candidate genes and ESTs. Of these, 1,275 (87.9%) have significant linkage to at least one other marker. The fraction of ESTs with significant linkage, which can be used as an estimate of map coverage, is 81.9%. We found the average marker retention frequency to be 18.4%. One cR3000 is equivalent to 61 kb, resulting in a potential resolution of approximately 350 kb.