930 resultados para Pulmonary toxicity


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The new Swiss Chronic Obstructive Pulmonary Disease (COPD) Guidelines are based on a previous version, which was published 10 years ago. The Swiss Respiratory Society felt the need to update the previous document due to new knowledge and novel therapeutic developments about this prevalent and important disease. The recommendations and statements are based on the available literature, on other national guidelines and, in particular, on the GOLD (Global Initiative for Chronic Obstructive Lung Disease) report. Our aim is to advise pulmonary physicians, general practitioners and other health care workers on the early detection and diagnosis, prevention, best symptomatic control, and avoidance of COPD as well as its complications and deterioration.

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BACKGROUND: This study is a single-institution validation of video-assisted thoracoscopic (VATS) resection of a small solitary pulmonary nodule (SPN) previously localized by a CT-guided hook-wire system in a consecutive series of 45 patients. METHODS: The records of all patients undergoing VATS resection for SPN preoperatively localized by CT-guided a hook-wire system from January 2002 to December 2004 were assessed with respect to failure to localize the lesion by the hook-wire system, conversion thoracotomy rate, duration of operation, postoperative complications, and histology of SPN. RESULTS: Forty-five patients underwent 49 VATS resections, with simultaneous bilateral SPN resection performed in 4. Preoperative CT-guided hook-wire localization failed in two patients (4%). Conversion thoracotomy was necessary in two patients (4%) because it was not possible to resect the lesion by a VATS approach. The average operative time was 50 min. Postoperative complications occurred in 3 patients (6%), one hemothorax and two pneumonia. The mean hospital stay was 5 days (range: 2-18 days). Histological assessment revealed inflammatory disease in 17 patients (38%), metastasis in 17 (38%), non-small-cell lung cancer (NSCLC) in 4 (9%), lymphoma in 3 (6%), interstitial fibrosis in 2 (4%), histiocytoma in one (2%), and hamartoma in one (2%). CONCLUSIONS: Histological analysis of resected SPN revealed unexpected malignant disease in more than 50% of the patients indicating that histological clarification of SPN seems warranted. Video-assisted thoracoscopic resection of SPN previously localized by a CT-guided hook-wire system is related to a low conversion thoracotomy rate, a short operation time, and few postoperative complications, and it is well suited for the clarification of SPN.

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Acacia mangium and Mimosa caesalpiniaefolia are fast-growing woody fabaceous species that might be suitable for phytoremediation of arsenic (As)-contaminated sites. To date, few studies on their tolerance to As toxicity have been published. Therefore, this study assessed As toxicity symptoms in A. mangium and M. caesalpiniaefolia seedlings under As stress in a greenhouse. Seedlings of Acacia mangium and M. caesalpiniaefolia were grown for 120 d in an Oxisol-sand mixture with 0, 50, 100, 200, and 400 mg kg-1 As, in four replications in four randomized blocks. The plants were assessed for visible toxicity symptoms, dry matter production, shoot/root ratio, root anatomy and As uptake. Analyses of variance and regression showed that the growth of A. mangium and M. caesalpiniaefolia was severely hindered by As, with a reduction in dry matter production of more than 80 % at the highest As rate. The root/shoot ratio increased with increasing As rates. At a rate of 400 mg kg-1 As, whitish chlorosis appeared on Mimosa caesalpiniaefolia seedlings. The root anatomy of both species was altered, resulting in cell collapse, death of root buds and accumulation of phenolic compounds. Arsenic concentration was several times greater in roots than in shoots, with more than 150 and 350 mg kg-1 in M. caesalpiniaefolia and A. mangium roots, respectively. These species could be suitable for phytostabilization of As-contaminated sites, but growth-stimulating measures should be used.

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To study the toxicity of nanoparticles under relevant conditions, it is important to reproducibly disperse nanoparticles in biological media in in vitro and in vivo studies. Here, single-walled nanotubes (SWNTs) and double-walled nanotubes (DWNTs) were physicochemically and biologically characterized when dispersed in phosphate-buffered saline (PBS) and bovine serum albumin (BSA). BSA-SWNT/DWNT interaction resulted in a reduction of aggregation and an increase in particle stabilization. Based on the protein sequence coverage and protein binding results, DWNTs exhibited higher protein binding than SWNTs. SWNT and DWNT suspensions in the presence of BSA increased interleukin-6 (IL-6) levels and reduced tumor necrosis factor-alpha (TNF-α) levels in A549 cells as compared to corresponding samples in the absence of BSA. We next determined the effects of SWNTs and DWNTs on pulmonary protein modification using bronchoalveolar lavage fluid (BALF) as a surrogate collected form BALB/c mice. The BALF proteins bound to SWNTs (13 proteins) and DWNTs (11 proteins), suggesting that these proteins were associated with blood coagulation pathways. Lastly, we demonstrated the importance of physicochemical and biological alterations of SWNTs and DWNTs when dispersed in biological media, since protein binding may result in the misinterpretation of in vitro results and the activation of protein-regulated biological responses.

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Thirty percent of patients suffering from malignant disease will develop pulmonary metastases. Effective chemotherapy is lacking for many of these tumors. Many studies suggest survival benefit in selected patients when pulmonary metastasectomy allows complete resection. Several operative approach may be offered in order to achieve complete resection and maximal lung sparring. Pre-operative workup must assess the control of the primary tumor and the possibility of performing complete resection. Minimally invasive approaches may offer better quality life and equivalent oncologic outcomes than open approach.

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Endogenous nitric oxide (NO) mediates pulmonary vasodilatation at birth, but inhaled NO fails to reduce pulmonary vascular resistance (PVR) in newborns with congenital diaphragmatic hernia (CDH). This study was designed to investigate the effects of ventilation, and the nature of its endogenous mediator, in fetal lambs with experimental CDH. Investigations at 138 days of gestation showed that ventilation markedly decreased PVR. Inhibition of NO synthesis reduced ventilation-induced pulmonary vasodilatation in vivo and increased in vitro isometric tension of vascular rings. Ventilation therefore reduces PVR at birth in lambs with CDH, and endogenous NO seems to contribute to this reduction.

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BACKGROUND: Adverse events in utero may predispose to cardiovascular disease in adulthood. The underlying mechanisms are unknown. During preeclampsia, vasculotoxic factors are released into the maternal circulation by the diseased placenta. We speculated that these factors pass the placental barrier and leave a defect in the circulation of the offspring that predisposes to a pathological response later in life. The hypoxia associated with high-altitude exposure is expected to facilitate the detection of this problem. METHODS AND RESULTS: We assessed pulmonary artery pressure (by Doppler echocardiography) and flow-mediated dilation of the brachial artery in 48 offspring of women with preeclampsia and 90 offspring of women with normal pregnancies born and permanently living at the same high-altitude location (3600 m). Pulmonary artery pressure was roughly 30% higher (mean+/-SD, 32.1+/-5.6 versus 25.3+/-4.7 mm Hg; P<0.001) and flow-mediated dilation was 30% smaller (6.3+/-1.2% versus 8.3+/-1.4%; P<0.0001) in offspring of mothers with preeclampsia than in control subjects. A strong inverse relationship existed between flow-mediated dilation and pulmonary artery pressure (r=-0.61, P<0.001). The vascular dysfunction was related to preeclampsia itself because siblings of offspring of mothers with preeclampsia who were born after a normal pregnancy had normal vascular function. Augmented oxidative stress may represent an underlying mechanism because thiobarbituric acid-reactive substances plasma concentration was increased in offspring of mothers with preeclampsia. CONCLUSIONS: Preeclampsia leaves a persistent defect in the systemic and the pulmonary circulation of the offspring. This defect predisposes to exaggerated hypoxic pulmonary hypertension already during childhood and may contribute to premature cardiovascular disease in the systemic circulation later in life.

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AIM: The aim of this study was to determine the presence of the neuronal nitric oxide synthase (nNOS) in near full-term lambs with congenital diaphragmatic hernia (CDH) and its role in the modulation of pulmonary vascular basal tone. METHODS: We surgically created diaphragmatic hernia on the 85th day of gestation. On the 135th, catheters were used to measure pulmonary pressure and blood flow. We tested the effects of 7-nitroindazole (7-NINA), a specific nNOS antagonist and of N-nitro-L-arginine (L-NNA), a nonspecific nitric oxide synthase antagonist. In vitro, we tested the effects of the same drugs on isolated pulmonary vessels. The presence of nNOS protein in the lungs was detected by Western blot analysis. RESULTS: Neither 7-NINA nor L-NNA modified pulmonary vascular basal tone in vivo. After L-NNA injection, acetylcholine (ACh) did not decrease significantly pulmonary vascular resistance (PVR). In vitro, L-NNA increased the cholinergic contractile-response elicited by electric field stimulation (EFS) of vascular rings from lambs with diaphragmatic hernia. CONCLUSION: We conclude that nNOS protein is present in the lungs and pulmonary artery of near full-term lamb fetuses with diaphragmatic hernia, but that it does not contribute to the reduction of pulmonary vascular tone at birth

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Rapport de synthèse : Plusieurs études suggèrent que les populations vivant en haute altitude sont mieux protégées contre l'hypertension pulmonaire hypoxique que celles originaires de la plaine. Cependant, les mécanismes sous jacents ne sont pas bien compris. Chez les Tibétains, la synthèse augmentée par le système respiratoire de monoxyde d'azote (NO) atténue l'hypertension pulmonaire hypoxique. Il a été spéculé que ce mécanisme pourrait représenter un mode généralisé d'adaptation à la haute altitude, mais il n'existe pas de preuve directe qui consume cette hypothèse. Nous avons donc mesuré la pression artérielle pulmonaire (par échocardiographie Doppler) ainsi que la concentration du NO dans l'air exhalé chez 34 Boliviens en bonne santé, nés et ayant toujours vécus en haute altitude (3600 m) et chez 34 Caucasiens apparentés pour l'âge et le sexe, nés en basse altitude mais vivant depuis de nombreuses années à cette même haute altitude (3600 mètres). La pression artérielle pulmonaire (24.3±5.9 vs. 24.7±4.9 mm Hg) et le NO exhalé (19.2±7.2 vs. 22.5±9.5 ppb) étaient similaires chez les Boliviens et les Caucasiens. Il n'y avait aucune corrélation entre la pression artérielle pulmonaire et le NO respiratoire dans les deux groupes. Ces résultats ne fournissent donc aucune évidence que les Boliviens nés en haute altitude sont mieux protégés contre l'hypertension pulmonaire hypoxique que les Caucasiens nés à basse altitude. Cela suggère que l'atténuation de l'hypertension pulmonaire par une synthèse accrue de NO respiratoire ne représente pas un mode universel d'adaptation des populations à la haute altitude. Abstract : There is evidence that high altitude populations may be better protected from hypoxic pulmonary hypertension than low altitude natives, but the underlying mechanism is incompletely understood. In Tibetans, increased pulmonary respiratory NO synthesis attenuates hypoxic pulmonary hypertension. It has been speculated that this mechanism may represent a generalized high altitude adaptation pattern, but direct evidence for this speculation is lacking. We therefore measured systolic pulmonary-artery pressure (Doppler echocardiography) and exhaled nitric oxide (NO) in 34 healthy, middle-aged Bolivian high altitude natives and in 34 age- and sex-matched, well-acclimatized Caucasian low altitude natives living at high altitude (3600 m). The mean ± SD systolic right ventricular to right arterial pressure gradient (24.3 ± 5.9 vs. 24.7 ± 4.9 mmHg) and exhaled NO (19.2 ± 7.2 vs. 22.5 ± 9.5 ppb) were similar in Bolivians and Caucasians. There was no relationship between ,pulmonary-artery pressure and respiratory NO in the two groups. These findings provide no evidence that Bolivian high altitude natives are better protected from hypoxic pulmonary hypertension than Caucasian low altitude natives and suggest that attenuation of pulmonary hypertension by increased respiratory NO synthesis may not represent a universal adaptation pattern in highaltitude populations.

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BACKGROUND: Chronic mountain sickness (CMS) is an important public health problem and is characterized by exaggerated hypoxemia, erythrocytosis, and pulmonary hypertension. While pulmonary hypertension is a leading cause of morbidity and mortality in patients with CMS, it is relatively mild and its underlying mechanisms are not known. We speculated that during mild exercise associated with daily activities, pulmonary hypertension in CMS is much more pronounced. METHODS: We estimated pulmonary artery pressure by using echocardiography at rest and during mild bicycle exercise at 50 W in 30 male patients with CMS and 32 age-matched, healthy control subjects who were born and living at an altitude of 3,600 m. RESULTS: The modest, albeit significant difference of the systolic right-ventricular-to-right-atrial pressure gradient between patients with CMS and controls at rest (30.3 +/- 8.0 vs 25.4 +/- 4.5 mm Hg, P 5 .002) became more than three times larger during mild bicycle exercise (56.4 +/- 19.0 vs 39.8 +/- 8.0 mm Hg, P < .001). CONCLUSIONS: Measurements of pulmonary artery pressure at rest greatly underestimate pulmonary artery pressure during daily activity in patients with CMS. The marked pulmonary hypertension during mild exercise associated with daily activity may explain why this problem is a leading cause of morbidity and mortality in patients with CMS.

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Arsenic is a metalloid highly toxic to plants and animals, causing reduced plant growth and various health problems for humans and animals. Silicon, however, has excelled in alleviating stress caused by toxic elements in plants. The aim of this study was to investigate the effects of Si in alleviating As stress in maize plants grown in a nutrient solution and evaluate the potential of the spectral emission parameters and the red fluorescence (Fr) and far-red fluorescence (FFr) ratio obtained in analysis of chlorophyll fluorescence in determination of this interaction. An experiment was carried out in a nutrient solution containing a toxic rate of As (68 μmol L-1) and six increasing rates of Si (0, 0.25, 0.5, 1.0, 1.5, and 2.0 mmol L-1). Dry matter production and concentrations of As, Si, and photosynthetic pigments were then evaluated. Chlorophyll fluorescence was also measured throughout plant growth. Si has positive effects in alleviating As stress in maize plants, evidenced by the increase in photosynthetic pigments. Silicon application resulted in higher As levels in plant tissue; therefore, using Si for soil phytoremediation may be a promising choice. Chlorophyll fluorescence analysis proved to be a sensitive tool, and it can be successfully used in the study of the ameliorating effects of Si in plant protection, with the Fr/FFr ratio as the variable recommended for identification of temporal changes in plants.

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The role of Pseudomonas aeruginosa isolated in sputum cultures from adults with obstructive chronic pulmonary disease (COPD) is not well known. However, this pathogen has many factors of virulence and is responsible for several clinical manifestations in this setting. Isolation of a new strain of Pseudomonas is associated with a significant risk of exacerbation of the COPD and its prevalence depends on the severity of the COPD. The role of Pseudomonas among patients with COPD apart from exacerbations is less clear, but it could be responsible for an ignition for the airways and progression for the disease. Currently, the relevance of a prophylactic antibiotic therapy has not yet been demonstrated in COPD holders of Pseudomonas.

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Sweet syndrome is a non infectious febrile disease with a neutrophilic infiltrate of dermis. Extracutaneous involvement can occur. We report two cases of Sweet syndrome with cutaneous and pulmonary involvement and give a short review of the literature of pulmonary involvement in Sweet syndrome.