Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 135
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
BMC Pulm Med ; 21(1): 425, 2021 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-34952578

RESUMO

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is a bronchopulmonary disease caused by a complex hypersensitivity to Aspergillus and is usually associated with underlying respiratory diseases such as asthma or cystic fibrosis. Mucus plugging can lead to segmental or lobar atelectasis, but complete lung atelectasis has been exceptionally reported in the literature, making it difficult to diagnose. The diagnosis of ABPA may however be suggested in patients without known predisposing respiratory disorder, even in the absence of other relevant radiographic findings. CASE PRESENTATION: We report five cases of total unilateral lung collapse secondary to ABPA in 70-81-year-old women. Two of them had a past history of ABPA, while total unilateral lung collapse was the first sign of the disease in the other three patients, contributing to the initial misdiagnosis. Flexible bronchoscopy was initially performed to remove mucus plugs from the obstructed airways but was inefficient in four cases. Corticosteroid and/or antifungal treatment was needed. CONCLUSION: ABPA can cause total unilateral lung collapse even in patients without known underlying chronic respiratory disease, making the diagnosis difficult. Flexible bronchoscopy should be considered when lung collapse is associated with respiratory distress but corticosteroids are the mainstay treatment for ABPA.


Assuntos
Aspergilose Broncopulmonar Alérgica/diagnóstico , Atelectasia Pulmonar/etiologia , Idoso , Idoso de 80 Anos ou mais , Aspergilose Broncopulmonar Alérgica/complicações , Feminino , Humanos
2.
Ann Pathol ; 34(1): 51-63, 2014 Feb.
Artigo em Francês | MEDLINE | ID: mdl-24630637

RESUMO

Mesothelioma is a rare disease less than 0.3% of cancers in France, very aggressive and resistant to the majority of conventional therapies. Asbestos exposure is nearly the only recognized cause of mesothelioma in men observed in 80% of case. In 1990, the projections based on mortality predicted a raise of incidence in mesothelioma for the next three decades. Nowadays, the diagnosis of this cancer is based on pathology, but the histological presentation frequently heterogeneous, is responsible for numerous pitfalls and major problems of early detection toward effective therapy. Facing such a diagnostic, epidemiological and medico-legal context, a national and international multidisciplinary network has been progressively set up in order to answer to epidemiological survey, translational or academic research questions. Moreover, in response to the action of the French Cancer Program (action 23.1) a network of pathologists was organized for expert pathological second opinion using a standardized procedure of certification for mesothelioma diagnosis. We describe the network organization and show the results during this last 15years period of time from 1998-2013. These results show the major impact on patient's management, and confirm the interest of this second opinion to provide accuracy of epidemiological data, quality of medico-legal acknowledgement and accuracy of clinical diagnostic for the benefit of patients. We also show the impact of these collaborative efforts for creating a high quality clinicobiological, epidemiological and therapeutic data collection for improvement of the knowledge of this dramatic disease.


Assuntos
Mesotelioma , Neoplasias Pleurais , França , Humanos , Mesotelioma/patologia , Patologia Clínica , Neoplasias Pleurais/patologia , Encaminhamento e Consulta , Sociedades Médicas , Fatores de Tempo
3.
Rev Mal Respir ; 40(6): 469-478, 2023 Jun.
Artigo em Francês | MEDLINE | ID: mdl-37308261

RESUMO

In some cases of interstitial lung disease (ILD), clinical and biological findings associated with CT scan pattern during multidisciplinary discussion (MDD) fail to yield a confident diagnosis. In these cases, histology may be necessary. Transbronchial lung cryobiopsy (TBLC) is a bronchoscopic procedure that has been developed in recent years and currently contributes to diagnostic work-up in patients with ILD. TBLC provides tissue samples for histological analysis with an acceptable risk of complications, consisting mainly in pneumothorax or bleeding. In addition to higher diagnostic yield than conventional forceps biopsies, the procedure shows a better safety profile than surgical biopsies. The indication to perform TBLC is decided during a 1st MDD and during a 2nd MDD, results can provide a diagnostic yield approximating 80%. TBLC appears to be an attractive, minimally invasive technique to be proposed as a first-line procedure in selected patients in experienced centers, while surgical lung biopsy may be considered as a second-line solution.


Assuntos
Doenças Pulmonares Intersticiais , Pneumotórax , Humanos , Biópsia , Técnicas Histológicas , Pulmão
4.
Rev Mal Respir ; 39(7): 626-632, 2022 Sep.
Artigo em Francês | MEDLINE | ID: mdl-35906150

RESUMO

INTRODUCTION: Immune checkpoint inhibitors have revolutionized the management of many cancers and achieved efficacy and durable response for some patients, including those with advanced cancers. However, immunotherapy is associated with side effects caused by the infiltration of immune cells into normal tissues, which can lead to disproportionate dysimmune reactions. While mostly of moderate intensity, these side effects can affect any organ, including the lung, the site of occasionally life-threatening interstitial lung disease. Their presentation can be similar to that of infectious pneumonia (COVID-19). OBSERVATIONS: We report the cases of 3 patients who presented between March and May 2020 with severe pulmonary toxicities secondary to immunotherapy, which led to with an initial hypothesis of SARS-CoV-2 pneumonia. After extensive investigations, the diagnosis of pulmonary toxicity to immunotherapy was given, and the clinical and radiological course following the initiation of corticosteroid therapy was favorable. CONCLUSION: Pulmonary toxicity secondary to immunotherapy remains a rare but potentially life-threatening side effect. The diagnostic approach requires the elimination of several differential diagnoses (infectious process, tumor progression, other etiologies of interstitial lung disease). This adverse event is reversible and evolution after initiation of corticosteroid therapy is usually favorable.


Assuntos
COVID-19 , Neoplasias , Pneumonia , Corticosteroides/uso terapêutico , COVID-19/diagnóstico , Teste para COVID-19 , Diagnóstico Diferencial , Humanos , Neoplasias/terapia , Pneumonia/diagnóstico , SARS-CoV-2
5.
Diagn Interv Imaging ; 101(11): 727-732, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32811758

RESUMO

PURPOSE: The primary objective of this study was to determine the diagnostic accuracy of percutaneous computed tomography (CT)-guided biopsy of persistent pulmonary consolidations. The secondary objective was to determine the complication rate and identify factors affecting diagnostic yield. MATERIALS AND METHODS: Two radiologists retrospectively reviewed 98 percutaneous CT-guided biopsies performed in 93 patients (60 men, 33 women; mean age, 62±14.0 (SD) years; range: 18-88 years) with persistent pulmonary consolidations. Final diagnoses were based on surgical outcomes or 12 months clinical follow-up findings. Biopsy results were compared to the final diagnosis to estimate diagnostic yield. RESULTS: A final diagnosis was obtained for all patients: 51/93 (54.8%) had malignant lesions, 12/93 (12.9%) specific definite benign lesions (including 9 infections, two pneumoconiosis and one lipoid pneumonia) and 30/93 (32.3%) non-specific benign lesions. CT-guided biopsy had an overall diagnostic yield of 60% (59/98) with a correct diagnosis for 50/51 malignant lesions (diagnostic yield of 98% for malignancy) and for 9/47 benign lesions (diagnostic yield of 19% for benign conditions). Major complications occurred in 4/98 (4%) of lung biopsies (four pneumothoraxes requiring chest tube placement). CONCLUSION: Percutaneous CT-guided biopsy is an alternative to endoscopic or surgical biopsy for the diagnosis of persistent consolidation with a low risk of severe complication.


Assuntos
Neoplasias Pulmonares , Biópsia , Biópsia por Agulha , Feminino , Humanos , Biópsia Guiada por Imagem , Pulmão/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
6.
Science ; 158(3797): 110-2, 1967 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-17798644

RESUMO

The small magnetic field strength observed near Mars by Mariner IV suggests that protons from the solar wind may enter the Martian atmosphere and produce ionization in addition to that produced by ultraviolet light and x-rays. It is found that solar protons produce a thin ionized layer at a rate of the order of 3 x 10(3) per cubic centimeter per second at a depth corresponding to the F(1) region in the terrestrial atmosphere. Unless the effective recombinative coefficient is very large (greater than 10(-5) centimeter cubed per second) or unless unusual diffusion effects are present, this layer should have been detected by Mariner IV, and therefore must be present in one of the observed ionized regions. Because of its very compact shape, the subsidiary maximum near 95 kilometers discovered in the Mariner-IV occultation experiment may be the proton ionization peak. If so, the major 120-kilometer maximum is an F(2) layer. Distinction between photon and proton ionization regions can be made by microwave occultation experiments aboard planetary orbiters.

7.
Science ; 173(3995): 417-20, 1971 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-17770442

RESUMO

Amino acids are produced under possible primitive Earth conditions by irradiation of gas mixtures with long-wavelength ultraviolet light, representing the most abundant useful energy source for prebiological organic synthesis. Hydrogen sulfide is the initial photon acceptor in this work; superthermal atomic hydrogen photodissociation products appear to initiate reactions leading to amino acid synthesis with an overall quantum yield on the order of 5X10(-5).

8.
Science ; 250: 415-8, 1990 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-11538073

RESUMO

The surface of Triton is very bright but shows subtle yellow to peach hues which probably arise from the production of colored organic compounds from CH4 + N2 and other simple species. In order to investigate possible relationships between chemical processes and the observed surface distribution of chromophores, we classify the surface units according to color/albedo properties, estimate the rates of production of organic chromophores by the action of ultraviolet light and high-energy charged particles, and compare rates, spectral properties, and expected seasonal redistribution processes to suggest possible origins of the colors seen on Triton's surface.


Assuntos
Química , Cor , Netuno , Atmosfera , Fenômenos Químicos , Meio Ambiente Extraterreno , Metano/análise , Nitrogênio/análise , Fotoquímica
9.
Science ; 189(4204): 722-3, 1975 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-17792541

RESUMO

A brown polymeric material, produced under simulated Jovian conditions, is composed primarily of cyclic octatomic sulfur, although a range of complex organic compounds is also present. The polymeric sulfur, produced from the ultraviolet photolysis of hydrogen sulfide, exhibits its strongest band at 465 reciprocal centimeters, in fair agreement with the frequency of the unidentified Jovian absorber recently announced by Houck et al. Polymeric octatomic sulfur may be an important constituent of the Jovian clouds.

10.
Science ; 177(4043): 52-6, 1972 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-17756316

RESUMO

Solar evolution implies, for contemporary albedos and atmospheric composition, global mean temperatures below the freezing point of seawater less than 2.3 aeons ago, contrary to geologic and paleontological evidence. Ammonia mixing ratios of the order of a few parts per million in the middle Precambrian atmosphere resolve this and other problems. Possible temperature evolutionary tracks for Earth and Mars are described. A runaway greenhouse efect will occur on Earth about 4.5 aeons from now, when clement conditions will prevail on Mars.

11.
Science ; 276(5316): 1217-21, 1997 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-11536805

RESUMO

Atmospheric mixing ratios of approximately 10(-5 +/- 1) for ammonia on the early Earth would have been sufficient, through the resulting greenhouse warming, to counteract the temperature effects of the faint early sun. One argument against such model atmospheres has been the short time scale for ammonia photodissociation by solar ultraviolet light. Here it is shown that ultraviolet absorption by steady-state amounts of high-altitude organic solids produced from methane photolysis may have shielded ammonia sufficiently that ammonia resupply rates were able to maintain surface temperatures above freezing.


Assuntos
Amônia/química , Atmosfera/química , Efeito Estufa , Metano/química , Raios Ultravioleta , Amônia/análise , Dióxido de Carbono/análise , Dióxido de Carbono/química , Planeta Terra , Evolução Planetária , Metano/análise , Metano/efeitos da radiação , Modelos Químicos , Fotólise , Sistema Solar
12.
Science ; 206(4425): 1363-8, 1979 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-17739279

RESUMO

The human species has been altering the environment over large geographic areas since the domestication of fire, plants, and animals. The progression from hunter to farmer to technologist has increased the variety and pace more than the geographic extent of human impact on the environment. A number of regions of the earth have experienced significant climatic changes closely related in time to anthropogenic environmental changes. Plausible physical models suggest a causal connection. The magnitudes of probable anthropogenic global albedo changes over the past millennia (and particularly over the past 25 years) are estimated. The results suggest that humans have made substantial contributions to global climate changes during the past several millennia, and perhaps over the past million years; further such changes are now under way.

13.
Science ; 181(4104): 1045-9, 1973 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-17731265

RESUMO

The equatorial sinuous channels on Mars detected by Mariner 9 point to a past epoch of higher pressures and abundant liquid water. Advective instability of the martian atmosphere permits two stable climates-one close to present conditions, the other at a pressure of the order of 1 bar depending on the quantity of buried volatiles. Variations in the obliquity of Mars, the luminosity of the sun, and the albedo of the polar caps each appear capable of driving the instability between a current ice age and more clement conditions. Obliquity driving alone implies that epochs of much higher and of much lower pressure must have characterized martian history. Climatic change on Mars may have important meteorological, geological, and biological implications.

14.
Science ; 199(4334): 1199-201, 1978 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-17745606

RESUMO

In an earlier paper, Khare and Sagan reported the production of a brownish polymeric material from the near-ultraviolet irradiation of simulated jovian atmospheres with a low hydrogen abundance. Examination of this product indicates that hydrogen sulfide is the initial photon acceptor; the powder resulting after extraction with benzene is 84 percent sulfur, largely S(8). In results reported here, the remaining 16 percent was pyrolyzed and then examined by gas chromatography-mass spectrometry. Pyrolysis at 450 degrees C yielded a series of alkanes, alkenes, C(3)-alkylbenzenes, aromatics, thiophenes, alkylthiophenes, alkylmercaptans, alkyldisulfides, together with the nitrogenous compounds hydrogen cyanide, methyl cyanide, alkylisothiocyanates, acrylonitrile, and allylisothiocyanates. Some of these compounds might be sought on Jupiter and Saturn and their satellites by remote infrared and ultraviolet spectroscopy and directly by entry probes.

15.
Science ; 164(3885): 1273-5, 1969 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-17772565

RESUMO

Lunar gravity data and orbital photography indicate that there is a mascon basin approximately 1000 kilometers in diameter on the farside of the moon and that Mare Marginis is the flooded fraction of a mascon basin approximately 900 kilometers in diameter.

16.
Science ; 249: 366-73, 1990 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-11538074

RESUMO

It has long been speculated that Earth accreted prebiotic organic molecules important for the origins of life from impacts of carbonaceous asteroids and comets during the period of heavy bombardment 4.5 x 10(9) to 3.8 x 10(9) years ago. A comprehensive treatment of comet-asteroid interaction with the atmosphere, surface impact, and resulting organic pyrolysis demonstrates that organics will not survive impacts at velocities greater than about 10 kilometers per second and that even comets and asteroids as small as 100 meters in radius cannot be aerobraked to below this velocity in 1-bar atmospheres. However, for plausible dense (10-bar carbon dioxide) early atmospheres, we find that 4.5 x 10(9) years ago Earth was accreting intact cometary organics at a rate of at least approximately 10(6) to 10(7) kilograms per year, a flux that thereafter declined with a half-life of approximately 10(8) years. These results may be put in context by comparison with terrestrial oceanic and total biomasses, approximately 3 x 10(12) kilograms and approximately 6 x 10(14) kilograms, respectively.


Assuntos
Evolução Biológica , Química Orgânica , Planeta Terra , Sistema Solar , Aminoácidos , Atmosfera , Dióxido de Carbono/análise , Formaldeído , Temperatura Alta , Cianeto de Hidrogênio , Planetas Menores , Fenômenos de Química Orgânica , Origem da Vida
17.
Science ; 222(4630): 1283-92, 1983 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-17773320

RESUMO

The potential global atmospheric and climatic consequences of nuclear war are investigated using models previously developed to study the effects of volcanic eruptions. Although the results are necessarily imprecise due to wide range of possible scenaros and uncertainty in physical parameters, the most probable first-order effects are serious. Significant hemispherical attenuation of the solar radiation flux and subfreezing land temperatures may be caused by fine dust raised in high-yield nuclear surface bursts and by smoke from city and forest fires ignited by airbursts of all yields. For many simulated exchanges of several thousand megatons, in which dust and smoke are generated and encircle the earth within 1 to 2 weeks, average light levels can be reduced to a few percent of ambient and land temperatures can reach -15 degrees to -25 degrees C. The yield threshold for major optical and climatic consequences may be very low: only about 100 megatons detonated over major urban centers can create average hemispheric smoke optical depths greater than 2 for weeks and, even in summer, subfreezing land temperatures for months. In a 5000-megaton war, at northern mid-latitude sites remote from targets, radioactive fallout on time scales of days to weeks can lead to chronic mean doses of up to 50 rads from external whole-body gamma-ray exposure, with a likely equal or greater internal dose from biologically active radionuclides. Large horizontal and vertical temperature gradients caused by absorption of sunlight in smoke and dust clouds may greatly accelerate transport of particles and radioactivity from the Northern Hemisphere to the Southern Hemisphere. When combined with the prompt destruction from nuclear blast, fires, and fallout and the later enhancement of solar ultraviolet radiation due to ozone depletion, long-term exposure to cold, dark, and radioactivity could pose a serious threat to human survivors and to other species.

18.
Science ; 155(3762): 556-8, 1967 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-17737405

RESUMO

Because of the high temperatures prevailing in the lower atmosphere of Venus, its chemistry is dominated by the tendency toward thermodynamic equilibrium. From the atomic composition deduced spectroscopically, the thermodynamic equilibrium composition of the atmosphere of Venus is computed, and the following conclusions drawn. (i) There can be no free carbon, hydrocarbons, formaldehyde, or any other organic molecule present in more than trace amounts. (ii) The original atomic composition of the atmosphere must have included much larger quantities of hydrogen and a carbon/oxygen ratio

19.
Science ; 168(3930): 470-3, 1970 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-5436082

RESUMO

A mixture of gases roughly simulating the primitive terrestrial atmosphere has been subjected to shock heating followed by a rapid thermal quench. Under strictly homogeneous conditions there is a very high efficiency of 5 x 10(10) molecules per erg of shock-injected energy for production of alpha-amino acids. Calculations suggest that rapid quenching bypasses the usual thermochemical barrier. The product of energy flux and efficiency implies the unexpected conclusion that shocks occurring on atmospheric entry of cometary meteors and micrometeorites and from thunder may have been the principal energy sources for pre-biological organic synthesis on the primitive earth.


Assuntos
Aminoácidos/síntese química , Amônia , Metano , Eletricidade , Gases , Pressão , Temperatura
20.
Science ; 247: 166-76, 1990 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-11538069

RESUMO

The latest understanding of nuclear winter is reviewed. Considerable progress has been made in quantifying the production and injection of soot by large-scale fires, the regional and global atmospheric dispersion of the soot, and the resulting physical, environmental, and climatic perturbations. New information has been obtained from laboratory studies, field experiments, and numerical modeling on a variety of scales (plume, mesoscale, and global). For the most likely soot injections from a full-scale nuclear exchange, three-dimensional climate simulations yield midsummer land temperature decreases that average 10 degrees to 20 degrees C in northern mid-latitudes, with local cooling as large as 35 degrees C, and subfreezing summer temperatures in some regions. Anomalous atmospheric circulations caused by solar heating of soot is found to stabilize the upper atmosphere against overturning, thus increasing the soot lifetime, and to accelerate interhemispheric transport, leading to persistent effects in the Southern Hemisphere. Serious new environmental problems associated with soot injection have been identified, including disruption of monsoon precipitation and severe depletion of the stratospheric ozone layer in the Northern Hemisphere. The basic physics of nuclear winter has been reaffirmed through several authoritative international technical assessments and numerous individual scientific investigations. Remaining areas of uncertainty and research priorities are discussed in view of the latest findings.


Assuntos
Clima , Guerra Nuclear , Fumaça , Atmosfera , Planeta Terra , Ozônio/análise , Temperatura
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA