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1.
Am J Transplant ; 13(10): 2722-9, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24007361

RESUMO

Primary graft failure and chronic lung allograft dysfunction (CLAD) limit lung transplant long-term outcomes. Various lung diseases have been correlated with surfactant protein (SP) expression and polymorphisms. We sought to investigate the role of SP expression in lung allografts prior to implantation, in relation to posttransplant outcomes. The expression of SP-(A, B, C, D) mRNA was assayed in 42 allografts. Posttransplant assessments include pulmonary function tests, bronchoscopy, broncho-alveolar lavage fluid (BALF) and biopsies to determine allograft rejection. BALF was assayed for SP-A, SP-D in addition to cytokines IL-8, IL-12 and IL-2. The diagnosis of CLAD was evaluated 6 months after transplantation. Lung allografts with low SP-A mRNA expression prior to implantation reduced survival (Log-rank p < 0.0001). No association was noted for the other SPs. Allografts with low SP-A mRNA had greater IL-2 (p = 0.03) and IL-12 (p < 0.0001) in the BALF and a greater incidence of rejection episodes (p = 0.003). Levels of SP-A mRNA expression were associated with the SP-A2 polymorphisms (p = 0.015). Specifically, genotype 1A1A(0) was associated with lower SP-A mRNA expression (p < 0.05). Lung allografts with low levels of SP-A mRNA expression are associated with reduced survival. Lung allograft SP-A mRNA expression appears to be associated with SP-A gene polymorphisms.


Assuntos
Rejeição de Enxerto/genética , Pneumopatias/cirurgia , Transplante de Pulmão , Polimorfismo Genético/genética , Proteína A Associada a Surfactante Pulmonar/genética , Adulto , Idoso , Aloenxertos , Líquido da Lavagem Broncoalveolar , Citocinas/genética , Feminino , Seguimentos , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Prognóstico , Estudos Prospectivos , Proteína D Associada a Surfactante Pulmonar/genética , RNA Mensageiro/genética , Estudos Retrospectivos , Taxa de Sobrevida
2.
Transpl Infect Dis ; 12(6): 551-4, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20553438

RESUMO

Cystic fibrosis (CF) lung transplant recipients infected with Burkholderia cenocepacia have a worse survival rate after lung transplantation than those who are not infected with this organism. The decreased survival is predominantly due to recurrent B. cenocepacia infection, with the majority of affected recipients succumbing within 3 months after transplant. B. cepacia complex (BCC) sepsis is one of the defining criteria for cepacia syndrome, an almost universally fatal necrotizing pneumonic illness. We report 2 CF patients who were long-term survivors of B. cenocepacia sepsis after lung transplantation. The aim of this report is to demonstrate that, although survival of B. cenocepacia sepsis after lung transplantation is extremely uncommon, with aggressive multidisciplinary management, long-term survival remains a realistic objective.


Assuntos
Infecções por Burkholderia/mortalidade , Complexo Burkholderia cepacia/isolamento & purificação , Fibrose Cística/complicações , Fibrose Cística/mortalidade , Transplante de Pulmão/efeitos adversos , Sepse/mortalidade , Adulto , Antibacterianos/uso terapêutico , Infecções por Burkholderia/microbiologia , Infecções por Burkholderia/cirurgia , Complexo Burkholderia cepacia/classificação , Complexo Burkholderia cepacia/efeitos dos fármacos , Fibrose Cística/tratamento farmacológico , Fibrose Cística/cirurgia , Empiema Pleural/microbiologia , Empiema Pleural/cirurgia , Feminino , Humanos , Pulmão/cirurgia , Abscesso Pulmonar/microbiologia , Abscesso Pulmonar/cirurgia , Transplante de Pulmão/mortalidade , Masculino , Sepse/tratamento farmacológico , Sepse/microbiologia , Sepse/cirurgia , Taxa de Sobrevida , Sobreviventes , Adulto Jovem
3.
Biochim Biophys Acta ; 1275(1-2): 96-100, 1996 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-8688454

RESUMO

We recently demonstrated that the gamma subunit in soluble F1-ATPase from Escherichia coli rotates relative to surrounding beta subunits during catalytic turnover (Duncan et al. (1995) Proc. Natl. Acad. Sci. USA 92, 10964-10968). Here, we extend our studies to the more physiologically relevant membrane-bound F0F1 complex. It is shown that beta D380C-F1, containing a beta-gamma intersubunit disulfide bond, can bind to F1-depleted membranes and can restore coupled membrane activities upon reduction of the disulfide. Using a dissociation/reconstitution approach with crosslinked beta D380C-F1, beta subunits containing an N-terminal Flag epitope (beta flag) were incorporated into the two non-crosslinked beta positions and the hybrid F1 was reconstituted with membrane-bound F0. Following reduction and ATP hydrolysis, reoxidation resulted in a significant amount of crosslinking of beta flag to the gamma subunit. This demonstrates that gamma rotates within F1 during catalytic turnover by membrane-bound F0-F1. Furthermore, the rotation of gamma is functionally coupled to F0, since preincubation with DCCD to modify F0 blocked rotation.


Assuntos
Trifosfato de Adenosina/metabolismo , ATPases Translocadoras de Prótons/química , Sequência de Aminoácidos , Sequência de Bases , Membrana Celular/enzimologia , Hidrólise , Dados de Sequência Molecular , ATPases Translocadoras de Prótons/metabolismo , Rotação
4.
J Clin Oncol ; 2(10): 1165-9, 1984 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-6387057

RESUMO

Peripheral eosinophilia is a rare but recognized accompaniment of malignant disease. Two unusual cases, one with a histiocytic lymphoma and the other with cervical carcinoma, are described. In the first patient, pulmonary infiltrates developed at the height of the eosinophilia and in the second, the peripheral eosinophilia heralded the onset of disseminated disease. Tumor-associated peripheral eosinophilia is reviewed, and it is concluded that peripheral eosinophilia associated with a malignant setting is a marker of extensive disease and is thus associated with a poor prognosis.


Assuntos
Carcinoma de Células Escamosas/complicações , Eosinofilia/etiologia , Linfoma Difuso de Grandes Células B/complicações , Neoplasias/complicações , Neoplasias do Colo do Útero/complicações , Adulto , Carcinoma de Células Escamosas/sangue , Fatores Quimiotáticos de Eosinófilos/metabolismo , Feminino , Humanos , Pneumopatias/patologia , Linfonodos/patologia , Linfoma/complicações , Linfoma Difuso de Grandes Células B/sangue , Masculino , Prognóstico , Radioterapia/efeitos adversos , Neoplasias do Colo do Útero/sangue
5.
Medicine (Baltimore) ; 66(5): 327-40, 1987 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3306259

RESUMO

In a retrospective review of 116 consecutive allogeneic bone marrow transplants (BMT), severe obstructive airways disease was identified in 11 patients. Lung pathology demonstrated bronchiolitis in 9 patients and physiologic studies showed small-airways disease consistent with bronchiolitis in the other 2. None of the 5 patients with associated infection survived, while 3 of the 6 patients without an identified pathogen stabilized or improved. Analysis of the 11 cases presented and all 25 cases reported in the literature (1982 to 1985) supports the conclusion that graft-versus-host disease is a major risk factor for bronchiolitis in BMT recipients. Among the proposed mechanisms for the development of bronchiolitis after allogeneic BMT, the 2 most likely are graft-versus-host disease directly causing bronchiolitis, and increased immunosuppressive therapy given for graft-versus-host disease predisposing to viral bronchiolitis. The available evidence would suggest that it is prudent to obtain serial pulmonary function tests even in asymptomatic patients post-BMT, and particularly in those with chronic graft-versus-host disease, in the hope that early detection will allow for early intervention that will arrest or reverse the progression of the obstructive airways disease.


Assuntos
Transplante de Medula Óssea , Bronquiolite Viral/etiologia , Doença Enxerto-Hospedeiro/mortalidade , Adolescente , Adulto , Anemia Aplástica/terapia , Bronquiolite Viral/mortalidade , Bronquiolite Viral/patologia , Feminino , Doença Enxerto-Hospedeiro/patologia , Humanos , Leucemia/terapia , Pneumopatias/etiologia , Pneumopatias/mortalidade , Pneumopatias/patologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Prognóstico
6.
Am J Surg Pathol ; 11(12): 965-71, 1987 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3318513

RESUMO

In a retrospective analysis (July 1979 to March 1984) of 120 allogeneic adult bone marrow transplant recipients, we identified seven patients with small-airway disease for whom no microbiologic agent was detected. Six had pulmonary function studies demonstrating air flow obstruction. Five of the seven patients had an open-lung biopsy showing pathologic changes within small airways; these varied from early bronchiolar wall damage to bronchiolitis obliterans. The inflammatory cell infiltrate was peribronchiolar, and consisted of polymorphonuclear leukocytes and lymphocytes in varying proportions. Three of the seven patients recovered following increased immunosuppressive therapy; the other four died. Because all seven patients had acute and chronic graft-versus-host disease, in the absence of any identifiable pathogen, we postulate that small-airway damage represents one of the facets of graft-versus host-disease. An additional analysis of 26 patients with respiratory symptomatology and available histologic material supports the hypothesis that small-airway disease in bone marrow transplant patients represents a risk factor for the subsequent development of respiratory opportunistic infections.


Assuntos
Transplante de Medula Óssea , Brônquios/patologia , Doença Enxerto-Hospedeiro/patologia , Doenças Respiratórias/fisiopatologia , Humanos , Infecções Oportunistas/fisiopatologia , Testes de Função Respiratória , Doenças Respiratórias/patologia , Estudos Retrospectivos , Fatores de Risco
7.
Transplantation ; 72(11): 1783-6, 2001 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11740388

RESUMO

BACKGROUND: Posttransplant lymphoproliferative disease (PTLD) is now a widely recognized complication of lung transplantation. In the current study, we present our experience with PTLD over a 15-year period, which includes the incidence rates in 242 lung allografts and the relative risk of developing PTLD in 146 patients with known pretransplantation Epstein-Barr virus (EBV) status. METHODS: Inpatient and outpatient charts of 300 consecutive lung transplant recipients between 1984 and 1999 were retrospectively reviewed. RESULTS: Twelve cases of PTLD were observed for a total incidence rate of 5.0%. Ten of these patients had pretransplantation EBV testing, and the consequent increase in relative risk for patients who were EBV negative was 6.8-fold. The mean time between organ transplantation and tissue diagnosis of PTLD was 17.6 months. Total 1-year survival rate from the time of diagnosis for the cohort was 58%, whereas 2-year survival rate was 50%. Median survival for the six patients who died was 4.5 months. CONCLUSIONS: These data suggest that although EBV seronegativity does carry a 6.8-fold increase in the relative risk of developing PTLD, long-term survival despite the development of PTLD can be achieved, and thus EBV seronegativity by itself should not be considered a contraindication to lung transplantation.


Assuntos
Reações Antígeno-Anticorpo , Herpesvirus Humano 4/imunologia , Transplante de Pulmão/efeitos adversos , Transtornos Linfoproliferativos/etiologia , Adolescente , Adulto , Estudos de Coortes , Feminino , Humanos , Incidência , Transtornos Linfoproliferativos/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida , Fatores de Tempo
8.
Environ Health Perspect ; 79: 283-90, 1989 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2785032

RESUMO

A rural population in southwestern Alberta, Canada, living downwind from natural gas refineries, has expressed concerns about an excess of adverse health outcomes over the last 25 years. This has escalated to the point of causing a prominent sociopolitical controversy within the province. As part of a large field epidemiologic study undertaken during the summer of 1985 to investigate possible health effects, a residential cohort study was carried out to study cancer incidence. The cohort was defined as all those individuals who resided in the area in 1970. A total of 30,175 person-years of risk within Alberta were experienced by this cohort from 1970 to 1984. The incident cancers during this period were enumerated by computerized record linkage with the Alberta Cancer Registry. Age- and sex-standardized incidence ratios, based on expected rates from three prespecified demographically similar, nonmetropolitan Southern Alberta populations, were 1.05, 1.09, and 1.03, respectively, none of which was significantly different from unity. Although they do not address the issue of etiologic association, these data can provide considerable reassurance to a community that was convinced it had experienced an epidemic of cancer.


Assuntos
Chuva Ácida/efeitos adversos , Poluentes Atmosféricos/efeitos adversos , Sulfeto de Hidrogênio/efeitos adversos , Neoplasias/induzido quimicamente , População Rural , Adulto , Idoso , Alberta , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Neoplasias Cutâneas/induzido quimicamente
9.
Chest ; 117(2): 476-81, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10669693

RESUMO

STUDY OBJECTIVE: Osteoporosis is a well-recognized complication of lung transplantation that may significantly impair the quality of life of transplant recipients. We performed a prospective study of bone mineral density (BMD) before and after transplantation to determine the degree of bone mass loss associated with lung transplantation Patients and design: We conducted a prospective study of BMD in 28 patients with various end-stage respiratory diseases pretransplantation and 6 to 12 months posttransplantation. The BMD of the lumbar spine (LS) and femoral neck (FN) were measured. All 28 patients were treated only with vitamin D and calcium supplementation posttransplant. The primary endpoint was the percentage change in BMD. The secondary endpoint was the incidence of fractures posttransplant. A univariate analysis was conducted to determine the various risk factors associated with bone mass loss pretransplant and posttransplant. RESULTS: Prior to transplantation, moderate to severe bone disease was evident. The mean (+/- SD) pretransplant T score (the number of SDs from the peak bone mass) and Z score (the number of SDs from the age-matched mean) for the LS were -1.72 +/- 1.37 and -1.44 +/- 1.31, respectively. The mean pretransplant T score and Z score for the FN were -2.65 +/- 1.01 and -1.5 +/- 1.43, respectively. Within 6 to 12 months posttransplant, the mean BMD for the LS decreased by 4.76% (p < 0.001), while the mean BMD for the FN decreased by 5.3% (p < 0.001). Five of the 28 patients (18%) suffered osteoporotic fractures posttransplant, while no fractures were documented pretransplant. The cumulative steroid dose posttransplant was associated with a drop in BMD for the LS and FN (r = 0.39, p = 0.039 and r = 0.63, p < 0.001, respectively), while a negative association was found between cumulative steroid use pretransplant and baseline LS and FN T scores (r = -0.4, p = 0. 02 and r = -0.43, p = 0.023, respectively). CONCLUSION: Within 6 to 12 months after lung transplantation, there is a significant decrease in BMD at both the LS and FN levels (approximately 5%) despite vitamin D and calcium supplementation. This drop in BMD is associated with a relatively high incidence of osteoporotic fractures posttransplant.


Assuntos
Densidade Óssea/fisiologia , Transplante de Pulmão/fisiologia , Osteoporose/fisiopatologia , Complicações Pós-Operatórias/fisiopatologia , Absorciometria de Fóton , Adulto , Idoso , Osso e Ossos/fisiopatologia , Feminino , Seguimentos , Fraturas Espontâneas/diagnóstico , Fraturas Espontâneas/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/diagnóstico , Complicações Pós-Operatórias/diagnóstico , Estudos Prospectivos , Fatores de Risco
10.
Chest ; 92(2): 303-9, 1987 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3301221

RESUMO

In a retrospective review of 21 bone marrow transplantation procedures (BMT), we identified ten episodes of acute pulmonary edema coinciding with significant weight gain in the second week after BMT. When we prospectively observed nine consecutive BMT recipients, six patients developed acute pulmonary edema associated with significant (p less than 0.05) weight gain and an increase in echocardiographically determined left ventricular end diastolic diameter. These findings led to a prospective prophylactic intervention study of 30 consecutive BMT patients. Prophylactic intervention consisting of reduced fluid volume of parenteral alimentation, and diuretic therapy was instituted at any clinical sign of fluid overload. No episode of pulmonary edema occurred. The dramatic difference--acute pulmonary edema occurred in 16/30 untreated vs 0/30 treated cases--suggests that this post-BMT complication is critically related to fluid balance and can be prevented by careful clinical examination, close monitoring of weight change, avoidance of fluid overload and the appropriate use of diuretic therapy.


Assuntos
Transplante de Medula Óssea , Edema Pulmonar/prevenção & controle , Adulto , Peso Corporal , Diuréticos/uso terapêutico , Ecocardiografia , Feminino , Hidratação , Humanos , Masculino , Estudos Prospectivos , Edema Pulmonar/etiologia , Estudos Retrospectivos , Fatores de Tempo , Equilíbrio Hidroeletrolítico
11.
Int J Epidemiol ; 23(5): 1091-8, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7860161

RESUMO

BACKGROUND: In the summer of 1985, the McGill Epidemiology Rapid Response Unit undertook a study comparing two areas exposed to emissions of 'sour gas' refineries to an unexposed area. One operational objective of the project was the identification and survey of all the people who had lived in the study area but had since moved (outmigrants). METHODS: We estimated the number of outmigrants (people who had ever lived in the area during the period 1957 to 1985) to be 3363 by using information obtained from our cross-sectional survey and from population statistics for the area of interest. Ten different methods combined lead to the identification of approximately 87% of all the outmigrants who left the study area during that period. We used vital statistics to identify the outmigrants who had died and mailed questionnaires to obtain the necessary information from the others. RESULTS: We confirmed the vital status of approximately 46% of them (1532/3363). The results from the outmigrant survey showed that they were younger than area residents, that they experienced lower rates of heart disease and hypertension and that they had moved for health reasons in only 1.3% of the cases. These findings were similar across comparison areas. CONCLUSION: We concluded that there was no effect due to migration bias on the cross-sectional study results. This evidence considerably strengthened the conclusions regarding the effects of exposure, a benefit that largely justified the cost of identifying and surveying the outmigrants.


Assuntos
Viés , Métodos Epidemiológicos , Migrantes , Adolescente , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Morbidade , Inquéritos e Questionários , Estatísticas Vitais
12.
J Heart Lung Transplant ; 20(3): 288-96, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11257554

RESUMO

BACKGROUND: It is well documented that malnourished and/or obese surgical patients have increased morbidity and mortality post-operatively. Only a few studies investigating the effect of nutritional status on mortality are available pertaining to the transplant population. Since limited data are available on the nutritional status and its effects on mortality in the lung transplant population, we sought to ascertain whether there is an association between mortality and preoperative nutritional status. METHODS: We examined mortality during the first 3 months after transplantation. Patients were grouped by body mass index (BMI) categories as < 17 kg/m(2), 17 to < 20 kg/m(2), 20 to 25 kg/m(2) (reference group), > 25 to 27 kg/m(2), and > 27 kg/m(2). Additional risk factors retrieved from the pre-transplant records included age, gender, diagnosis, energy requirements, protein requirements, protein and caloric intake, and weight history. Logistic regression for univariate and multivariate analysis for mortality used recipient age, gender, disease category, pre-transplant cytomegalovirus (CMV) serology, transplant type (single or bilateral), and donor age, gender, and CMV serology. RESULTS: The likelihood estimates or odds ratios (ORs) of the risk of death within 90 days of lung transplantation for the BMI categories compared to the reference group were 3.7 for BMI < 17 kg/m(2) (p = 0.085), 1.6 for BMI < 17 to 20 kg/m(2) (p = 0.455), 3.5 for BMI > 25 to 27 kg/m(2) (p = 0.069), and 5.0 for BMI > 27 kg/m(2) (p = 0.003). CONCLUSIONS: In patients with a pre-transplant BMI < 17 kg/m(2) or > 25 kg/m(2) the risk of dying within 90 days post-transplant was increased. In patients with a pre-transplant BMI of > 27 kg/m(2) the risk was significantly higher in than the reference group.


Assuntos
Índice de Massa Corporal , Transplante de Pulmão/mortalidade , Estado Nutricional , Adulto , Causas de Morte , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Fatores de Risco
13.
Clin Chest Med ; 11(2): 323-32, 1990 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2189666

RESUMO

Pulmonary complications are a common cause of morbidity and mortality after bone marrow transplantation. Some of these complications are infectious and related to the degree of ongoing immunosuppression, and thus vary with the posttransplant marrow reconstitution and the need for continued immunomodulating drugs. Noninfectious complications are related to previous chemotherapy, the transplantation protocol and conditioning regimen, and, in allogeneic transplants, the presence of graft-versus-host disease. The various complications are classified based on their timing after the transplant procedure. A diagnostic and therapeutic approach is outlined and the prognosis is discussed.


Assuntos
Transplante de Medula Óssea/efeitos adversos , Pneumopatias/etiologia , Transplante de Medula Óssea/imunologia , Doença Enxerto-Hospedeiro/etiologia , Humanos , Tolerância Imunológica , Pneumopatias/diagnóstico , Pneumopatias/tratamento farmacológico , Infecções Oportunistas/etiologia , Complicações Pós-Operatórias/etiologia
14.
J Thorac Imaging ; 2(4): 4-14, 1987 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3316684

RESUMO

Pulmonary tumor embolism is a common finding at autopsy but is generally perceived as a difficult diagnosis to make ante mortem. After a retrospective review of 164 reported cases of pulmonary tumor embolism, we identified a typical profile of clinical, laboratory, and imaging features that may permit confident clinical diagnosis in most patients with this condition. The clinical features include a documented or suspected underlying malignancy, acute to subacute onset of dyspnea, and signs of cor pulmonale. Supportive laboratory features are hypoxemia or increased alveolar-arterial oxygen gradient, and invasive or noninvasive evidence of pulmonary artery hypertension. Typical imaging findings are normal chest radiographs; multiple, subsegmental, peripheral perfusion defects on ventilation-perfusion lung scans; and delayed filling with or without subsegmental filling defects but without a thrombus on pulmonary angiogram. Radiolabeled monoclonal antibody imaging and pulmonary microvascular cytology sampling techniques are promising diagnostic tests for early diagnosis of pulmonary tumor embolism.


Assuntos
Neoplasias Pulmonares , Células Neoplásicas Circulantes , Adulto , Anticorpos Monoclonais , Diagnóstico por Imagem , Feminino , Hemodinâmica , Humanos , Pulmão/irrigação sanguínea , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/fisiopatologia , Masculino , Microcirculação , Pessoa de Meia-Idade
15.
Can J Public Health ; 81(2): 107-13, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2331647

RESUMO

Concerns about excesses in a wide array of adverse health outcomes have been expressed for over 25 years by a rural population in southwestern Alberta, living downwind from natural gas refineries. Among these has been the perception that deaths have occurred more frequently than ought to have been expected. As part of a large field epidemiologic study undertaken during the summer of 1985 to investigate possible health effects in this area, a residential cohort study was carried out to study mortality. The cohort was defined as all those individuals who resided in the area in 1970. A total of 30,175 person-years of risk within Alberta were experienced by this cohort during 1970-84. The deaths during this period were enumerated by resident reports and by manual record linkage with the death records of the Alberta Bureau of Vital Statistics. Age- and sex-standardized mortality ratios, based on expected rates from 2 pre-specified demographically similar, non-metropolitan Southern Alberta populations, were 0.88 and 0.84 respectively, neither of which was significantly different from unity. These data cannot address the question of etiology but they can do much to allay the anxieties of a community convinced it had experienced an epidemic of death.


Assuntos
Exposição Ambiental , Combustíveis Fósseis , Indústrias , Mortalidade , Características de Residência , Adulto , Idoso , Alberta , Causas de Morte , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , População Rural
20.
Rev Sci Instrum ; 80(7): 074501, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19655969

RESUMO

We discuss the design, operation, and performance of a vacuum setup constructed for use in zero (or reduced) gravity conditions to initiate collisions of fragile millimeter-sized particles at low velocity and temperature. Such particles are typically found in many astronomical settings and in regions of planet formation. The instrument has participated in four parabolic flight campaigns to date, operating for a total of 2.4 h in reduced-gravity conditions and successfully recording over 300 separate collisions of loosely packed dust aggregates and ice samples. The imparted particle velocities achieved range from 0.03 to 0.28 m s(-1) and a high-speed, high-resolution camera captures the events at 107 frames/s from two viewing angles separated by either 48.8 degrees or 60.0 degrees. The particles can be stored inside the experiment vacuum chamber at temperatures of 80-300 K for several uninterrupted hours using a built-in thermal accumulation system. The copper structure allows cooling down to cryogenic temperatures before commencement of the experiments. Throughout the parabolic flight campaigns, add-ons and modifications have been made, illustrating the instrument flexibility in the study of small particle collisions.


Assuntos
Temperatura Baixa , Aceleradores de Partículas/instrumentação , Ausência de Peso , Desenho Assistido por Computador , Cobre , Poeira , Desenho de Equipamento , Gelo , Movimento (Física) , Vácuo
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