RESUMO
The emergence of carbon dots (C-dots) has aroused increasing attention owing to their excellent chemical and physical properties, such as favorable biocompatibility and an outstanding fluorescence (FL) property. Most reported C-dots show blue emission, which hinders their applications in the biomedical field due to the strong FL background of biosamples. Therefore, strategies for the achievement of long-wavelength fluorescent C-dots are urgently needed. Herein, red emissive biocompatible C-dots were prepared from polythiophene (PTh) through chemical cutting by nitric acid. Various methods were utilized to shed light on the luminescence mechanism of the C-dots. The results demonstrated that FL emission of the prepared C-dots was mainly dominated by sp2 domains. The C-dots were well-applied in in vitro imaging. This work prepared red fluorescent C-dots from the perspective of the structure of C-dots, which would benefit the regulation of the FL of C-dots.
Assuntos
Carbono , Ácido Nítrico , Polímeros , Tiofenos , Carbono/administração & dosagem , Carbono/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Fluorescência , Humanos , Microscopia Eletrônica de Varredura , Ácido Nítrico/administração & dosagem , Ácido Nítrico/química , Polímeros/administração & dosagem , Polímeros/química , Espectrometria de Fluorescência , Tiofenos/administração & dosagem , Tiofenos/químicaRESUMO
The treatment of cutaneous viral warts caused by human papillomavirus (HPV) infection is often subject to local recurrence and a long clinical and treatment course. Our aim was to analyze real-life data on the treatment of difficult-to-treat warts from a multicenter postmarketing surveillance assessment on the efficacy, tolerability, and safety of a commercially available nitric-zinc complex solution (NZCS). Dermatologists from 14 Italian centers completed a questionnaire about their clinical experience on treatment of "difficult-to-treat" warts, which included warts in the plantar, periungual, anogenital and aesthetically sensitive areas. The questionnaire was designed to obtain detailed information on wart treatment and compare NZCS efficacy with previous treatments. Of 106 questionnaires returned, 83 reported NZCS use; 67 had previous treatments (23 cryotherapy, 2 electrocoagulation, 12 other topical application, and 30 combined treatment, such as laser, cryotherapy, and/or electrocoagulation). NZCS had superior efficacy to that of previous treatments (p < .0001), resulting in 84.1% with a full or partial clearance (vs. 44.8% for previous treatments), and had better local tolerability (p < .0001). NZCS showed better efficacy and tolerability than other previous wart treatments.
Assuntos
Ácido Nítrico/administração & dosagem , Infecções por Papillomavirus/tratamento farmacológico , Verrugas/tratamento farmacológico , Zinco/administração & dosagem , Administração Cutânea , Adolescente , Adulto , Criança , Fármacos Dermatológicos/administração & dosagem , Fármacos Dermatológicos/efeitos adversos , Feminino , Humanos , Itália , Masculino , Ácido Nítrico/efeitos adversos , Vigilância de Produtos Comercializados , Inquéritos e Questionários , Resultado do Tratamento , Verrugas/virologia , Adulto Jovem , Zinco/efeitos adversosRESUMO
PURPOSE: Bronchiolitis obliterans (BO) is a highly debilitative and fatal syndrome associated with a series of severe lower airway disorders. The pathogenesis of BO is complicated and not entirely understood. An appropriate animal model of BO may aid research into its pathogenesis. Here, we establish a mouse model of BO to provide insight into this disease. MATERIALS AND METHODS: 6-8 week old BABL/c mice were exposed to 5% nitric acid (NA) aerosol through a nebulizer for 3 hours, and controls were exposed to distilled water instead. Symptoms, airway resistance and pathological process were observed dynamically. The levels of matrix metalloproteinase-2 (MMP-2), MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1), 8-isoprostane and myeloperoxidase (MPO) in lung tissue and bronchoalveolar lavage fluids (BLAF) were determined by ELISA on day 3, 7, 14, 28 and 56 after the aerosol nebulization. RESULTS: Typical BO lesions were observed in NA nebulized mice characterized histologically by initial necrotizing bronchiolitis and final airway fibrosis at day 28 after the aerosol nebulization. NA nebulized mice also exhibited labored breathing and significantly increased airway resistance. Expression of MMP-2, MMP-9, TIMP-1, 8-isoprostane and MPO were significantly elevated in NA nebulized mice in different time frame. CONCLUSION: A murine BO model was established by NA aerosol inhalation. It provides an easy, economic, and reproducible mice model for BO research.
Assuntos
Bronquiolite Obliterante/induzido quimicamente , Modelos Animais de Doenças , Ácido Nítrico/toxicidade , Aerossóis/administração & dosagem , Animais , Bronquiolite Obliterante/metabolismo , Dinoprosta/análogos & derivados , Dinoprosta/metabolismo , Inalação , Metaloendopeptidases/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Ácido Nítrico/administração & dosagem , Peroxidase/metabolismo , Reprodutibilidade dos Testes , Fatores de Tempo , Inibidor Tecidual de Metaloproteinase-1/metabolismoRESUMO
In this proof of concept study, 50 lesions from 15 patients with multiple seborrheic keratoses (SKs) were treated with a novel aqueous solution containing nitric acid, zinc and copper salts, and organic acids (acetic, lactic, and oxalic acid). Treatment consisted in the application of an amount of the solution sufficient to obtain a whitening/yellowish reaction. Application of the nitric-zinc solution was performed every other week until clinical and dermoscopic clearance or crust formation, for a maximum of 4 applications. Efficacy evaluation was performed at 8 weeks (T1) and 6 months (T2). All subjects, who reported no or minimal discomfort during and after the application of the solution, completed the study. At T1, a complete clinical and dermoscopic resolution was observed in 37 lesions after an average of 3 applications/lesion (range 2-4). A partial response, with minimal persistent residual spots, was detected in the remaining 13 lesions. All patients with complete clearance showed no relapses at a 6-month follow-up (T2). The positive preliminary results indicate that this novel solution may represent a promising alternative option for SKs especially in patients not keen or eligible to undergo invasive tissue-destructive procedures.
Assuntos
Fármacos Dermatológicos/administração & dosagem , Dermoscopia/métodos , Ceratose Seborreica/tratamento farmacológico , Administração Cutânea , Ácidos Carboxílicos/administração & dosagem , Cobre/administração & dosagem , Feminino , Seguimentos , Humanos , Ceratose Seborreica/patologia , Masculino , Pessoa de Meia-Idade , Ácido Nítrico/administração & dosagem , Estudo de Prova de Conceito , Fatores de Tempo , Resultado do Tratamento , Zinco/administração & dosagemRESUMO
Although garlic oil and nitrate can effectively suppress ruminal methane (CH4 ) production in vitro, the application of these compounds is associated with suppressed total volatile fatty acid (VFA) concentration. On the other hand, the effectiveness of fumarate as a ruminal CH4 mitigating agent is variable but its application increases total VFA concentration. We therefore hypothesized that the different characteristics of the compounds can compensate for the shortcomings of the other. The objective of this study was to develop an optimal blend of garlic oil, nitrate and fumarate that can suppress in vitro ruminal CH4 without affecting total VFA concentration. Three ruminal in vitro fermentation experiments were carried out. The first one, a one factor at a time experiment was employed to investigate the effective concentration of each of the compounds on CH4 and VFA production by ruminal bacteria. We then applied the fractional factorial design and response surface methodology in the second experiment to determine optimal concentrations of the compounds in the blend. The optimal blending of garlic oil, fumarate and nitrate was determined to be 50 mg/l, 15 mm and 20 mm, respectively. This simulated optimal blend was verified in a 48 h in vitro batch fermentation experiment. The blend achieved the intended goal of suppressing CH4 whilst maintaining total VFA concentration. The blend and nitrate suppressed archaea populations (p < 0.001) but did not affect the total microbial population (p = 0.945). The observed results could be explained by additive effects of the agents making up the blend. Supplementing a high concentrate diet with the blend can significantly decrease ruminal CH4 and maintain total VFAin vitro. These findings however, need to be verified in vivo using the optimized ratio of combining the three methane inhibitors as a guide.
Assuntos
Compostos Alílicos/farmacologia , Bactérias/efeitos dos fármacos , Fumaratos/farmacologia , Ácido Nítrico/farmacologia , Rúmen/microbiologia , Sulfetos/farmacologia , Compostos Alílicos/administração & dosagem , Animais , Bactérias/classificação , Bactérias/metabolismo , Fermentação , Fumaratos/administração & dosagem , Ácido Nítrico/administração & dosagem , Sulfetos/administração & dosagemRESUMO
AIM: Treatment of plantar and periungueal warts (so called "difficult-to-treat" warts, DTW) and external genital warts (EGW) remains unsatisfactory. Medical or invasive procedures are partially effective and/or painful. Furthermore recurrences rates after treatments are still a relevant problem for all the available therapies. Nitric-zinc complex is a solution for topical application containing nitric acid, zinc, copper and organic acids able to induce a caustic effect of the wart trough mummification and proteins denaturation/coagulation action. Nitric-zinc complex has been shown to be an effective and well tolerated treatment of common warts. METHODS: We evaluated in a prospective open label 4-centre trial, the efficacy and local tolerability of nitric-zinc complex in the treatment of EGW and DTW. A total of 37 immunocompetent subjects (20 men and 17 women; mean age: 45 years) with single or multiple lesions, were enrolled, after their informed consent. A total of 30 subjects had EGW, 2 subjects had plantar warts, 2 warts of the hand and 3 periungueal lesions. Nitric-zinc aqueous solution was applied topically using a 30 mL capillary tube over the lesions until a whitening/yellowish reaction appeared. A second (or more, if needed) application was performed at two-week interval until a complete clinical cure rate was observed. Primary outcome of the study was the clinical evaluation with picture documentation of the evolution of lesions classified as total cure, partial disappearance or no effect. Topical tolerability was evaluated through patient's reported adverse events. RESULTS: All subjects completed the study. A complete cure of lesions was observed in 31 subjects (90%) after one and up to four applications. Three patients with EGW (8%) showed a partial disappearance of lesions and one (2%) subject was no responder to four nitric-zinc complex applications. The product was well tolerated. No serious adverse events were observed or recorded. CONCLUSION: Nitric-zinc complex topical solution has shown to be an effective and well tolerated treatment of EGW and "difficult-to-treat" warts with a 90% of subjects with a total cure after one or up to four applications. A total or partial response was observed in 99% of the subjects. Nitric-zinc complex could be considered an easy-to-use effective treatment strategy of "difficult-to-treat" warts and external genital warts. Additional studies comparing nitric-zinc complex to other strategies are warranted.
Assuntos
Fármacos Dermatológicos/uso terapêutico , Verrugas/tratamento farmacológico , Administração Tópica , Adulto , Condiloma Acuminado/tratamento farmacológico , Fármacos Dermatológicos/administração & dosagem , Fármacos Dermatológicos/efeitos adversos , Feminino , Dermatoses do Pé/tratamento farmacológico , Doenças dos Genitais Femininos/tratamento farmacológico , Doenças dos Genitais Masculinos/tratamento farmacológico , Dermatoses da Mão/tratamento farmacológico , Humanos , Imunocompetência , Masculino , Pessoa de Meia-Idade , Ácido Nítrico/administração & dosagem , Ácido Nítrico/efeitos adversos , Ácido Nítrico/uso terapêutico , Estudos Prospectivos , Soluções , Resultado do Tratamento , Zinco/administração & dosagem , Zinco/efeitos adversos , Zinco/uso terapêuticoRESUMO
The aim of this article is to present the decalcification process dynamic of mineralized tissue in dogs, teeth and jaw, comparing the traditional decalcification method, immersion, and microwave, immersion followed by irradiation using a domestic microwave oven, accompanying the liberation of calcium through spectrophotometer of atomic absorption. It was used as decalcified agent, EDTA solution or nitric acid. The results showed that with the use of nitric acid (5 percent), after 15 days, the irradiated fragments could be processed for histological analysis, otherwise the tooth not irradiated need to be submerged for 65 days. The EDTA decalcified action was slower than the nitric acid. The histological observations of the irradiated samples showed an excellent preservation of the morphological characteristics, independently of the decalcified agent used.
El objetivo de este artículo fue presentar, un método de descalcificación dinámico de tejido mineralizado de perros, dientes y mandíbula, comparando el método de descalcificación tradicional e irradiación en horno de microondas, analizando la liberación de calcio en espectro fotómetro de absorción atómica. Usamos como agente descalcificante, solución de EDTA y acido nítrico. Los resultados mostraron que los fragmentos descalcificados con ácido nítrico después de 15 días, ya podían ser preparados para análisis histológico, el diente al ser irradiado tardó 65 días para ser descalcificado. El EDTA descalcificó lentamente, en relación al ácido nítrico. Las observaciones histológicas de las muestras irradiadas mostraron una excelente preservación de las características morfológicas independiente del agente descacificador usado.
Assuntos
Animais , Cães , Ácido Nítrico/administração & dosagem , Técnica de Desmineralização Óssea/métodos , Micro-OndasRESUMO
Two patients presented with potentially fatal pulmonary oedema after accidental exposure to nitric and hydrofluoric acid fumes during electroplating. Despite aggressive respiratory support, one succumbed to respiratory failure 3.5h after inhalation. The other patient also rapidly progressed to respiratory failure. Extracorporeal life support (ECLS) was started 5h after exposure at the ED. During ECLS, hypoxia improved, but pulmonary oedema shown by chest radiography became aggravated. N-Acetyl cysteine and calcium gluconate were given i.v. on the first day of admission and nebulised for 48 h after exposure. Pulmonary secretions were significantly reduced 24 h after the nebulising therapy began. Ultimately, the patient was discharged without serious pulmonary or neurological complications after 28 days of hospitalisation. In this case, early ECLS, nebulised antioxidant and antidote were available to treat potentially fatal pulmonary oedema after exposure to nitric and hydrofluoric acid fumes.
Assuntos
Substâncias Explosivas/efeitos adversos , Oxigenação por Membrana Extracorpórea/métodos , Ácido Fluorídrico/efeitos adversos , Ácido Nítrico/efeitos adversos , Edema Pulmonar/induzido quimicamente , Edema Pulmonar/terapia , Adulto , Poluentes Ocupacionais do Ar/efeitos adversos , Galvanoplastia , Substâncias Explosivas/administração & dosagem , Evolução Fatal , Humanos , Ácido Fluorídrico/administração & dosagem , Masculino , Ácido Nítrico/administração & dosagem , Exposição Ocupacional/efeitos adversosRESUMO
Immune cell airway infiltration and the bronchovascular remodeling process have shown to be promising in the understanding of bronchiolitis obliterans (BO) pathogenesis. In this study we sought to validate the importance of immune cells, whether diffusely distributed or forming lymphoid follicles, collagen density, and vascular factors. Eight weeks after a single nitric acid (NA) nasal instillation, lung changes were characterized by lumen distortion, epithelial layer folding, reduction or total obliteration of terminal bronchiole (TB) lumen, and wall thickness increase. The morphologic changes in the TB and TA (terminal artery) lumen coincide with the measurement difference in the three groups. The TB diameter and lumen were significantly decreased in BO when compared with non-BO lungs (0.76 +/- 0.05 microm vs. 0.81 +/- 0.05 microm and 12,286.13 +/- 378.83 microm vs. 18,182.27 +/- 5,593.98 microm, p = 0.05 and p = 0.01, respectively). Equally significant was the increase in TB thickness in BO when compared with the non-BO group (201.72 +/- 35.75 microm vs. 149.75 +/- 40.61 microm, p = 0.007). The morphologic changes in immune cells seen in TB, TA, and bronchus-associated lymphoid tissue (BALT) also coincide with the quantification differences observed in the three groups. We concluded that immune cell infiltration and collagen/vascular remodeling are related to the spectrum of histologic changes in a BO nasal-induced model in mice and may be an appropriate target for prospective studies of human bronchiolitis.
Assuntos
Brônquios/efeitos dos fármacos , Brônquios/imunologia , Bronquiolite Obliterante/imunologia , Modelos Animais de Doenças , Ácido Nítrico/administração & dosagem , Administração Intranasal , Animais , Linfócitos B/imunologia , Brônquios/irrigação sanguínea , Brônquios/fisiologia , Bronquiolite Obliterante/patologia , Colágeno/fisiologia , Feminino , Imuno-Histoquímica , Instilação de Medicamentos , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Neutrófilos/imunologia , Linfócitos T/imunologiaRESUMO
BACKGROUND: We aimed to determine the local and systemic effects of widely available household cleaners, namely 45% nitric acid (NHO(3)), and 18% hydrochloric acid (HCl), in a rat model. METHODS: This prospective, experimental, placebo-controlled trial was carried out in the Animal Research Laboratory of Akdeniz University hospital. Commonly available solution of 45% NHO(3) and 18% HCl were tested against normal saline. Each solution was administrated orally to groups consisting of ten rats. The metabolic changes were determined by measuring the pH and calcium (Ca) levels before and after the administration of solutions. In addition, the pathological changes and mortality rates were determined for each group. RESULTS: There was a statistically significant increase in the post-ingestion (30 minutes later) Ca levels and a decrease in the post-ingestion pH levels after the administration of test solution in the NHO(3) (p=0.006 for Ca increase, p=0.001 for pH decrease) and HCl (p=0.007 for Ca increase, p=0.023 for pH decrease) groups. There was also a statistically significant difference between groups for Ca increase (p=0.000) and pH decrease (p=0.006). In post hoc analysis, the difference between the groups was found to be originated from the placebo group. In the pathological evaluation of esophagus and stomach, there was a statistically significant difference between groups (p=0.009 (E) and p=0.016 (S)) and the difference was found to be originated from the control group (p=0.543 (E), p=0.244 (S) for NHO(3) and HCl). The 30-minute mortality rates were 0,2 in the NHO(3) group, 0,6 in the HCl group and 0 in the control group. CONCLUSION: Serious metabolic and mild local pathological changes can occur after the ingestion of household NHO3 and HCl solutions. Further studies should be performed to elucidate the causes of death following oral ingestion of these compounds and appropriate public health warnings should be taken.
Assuntos
Queimaduras Químicas/patologia , Esôfago/efeitos dos fármacos , Ácido Clorídrico/toxicidade , Ácido Nítrico/toxicidade , Estômago/efeitos dos fármacos , Administração Oral , Animais , Cálcio/sangue , Modelos Animais de Doenças , Esôfago/patologia , Ácido Clorídrico/administração & dosagem , Concentração de Íons de Hidrogênio , Ácido Nítrico/administração & dosagem , Ratos , Ratos Wistar , Estômago/patologiaRESUMO
BACKGROUND: Childhood bronchiolitis obliterans (CBO) is an infrequent but severe disease, characterized by persistent obstructive respiratory symptoms after an acute episode of bronchiolitis. Its etiology is mostly postviral, especially in developing countries. Pathologically, CBO is characterized as constrictive-type BO. The pathogenesis of this disease is poorly understood and there is no specific treatment. Animal models could help to better understand the sequence of events culminating in bronchiolar obliteration and serve as basis for experimental therapeutic research. OBJECTIVES: In this study, we adapted the nitric acid (NA) technique to develop a suitable model to study CBO in rats. METHODS: We have intratracheally instilled 0.5% NA or saline and studied the histological lesions on days 2, 7, 14 and 30. NA-instilled animals developed a sequence of bronchiolar lesions that included necrotizing bronchiolitis, proliferative (PROL) bronchiolar lesions and constrictive (CONS) bronchiolar lesions with bronchiectasis, mucostasis and macrophagic accumulation. RESULTS: The frequency of PROL lesions decreased and that of the CONS lesions increased, with a statistically significant difference at the sacrifice days, except for day 7 (PROL vs. CONS lesions day 2: p = 0.001; PROL vs. CONS lesions day 7: p = 0.38; PROL vs. CONS lesions day 14: p < 0.001; PROL vs. CONS lesions day 30: p < 0.001). CONCLUSIONS: We conclude that this model presents histological similarities with the histological picture of CBO, being suitable for further developmental and therapeutic experimental research in this field.
Assuntos
Brônquios/patologia , Bronquiolite Obliterante/fisiopatologia , Modelos Animais de Doenças , Ratos Wistar , Animais , Criança , Feminino , Humanos , Masculino , Ácido Nítrico/administração & dosagem , RatosRESUMO
Research has shown that mandibular premolars have the highest rate of orthodontic bracket bond failure. Bond strength is thought to depend on the quality and quantity of enamel etch produced by the acid. Phosphoric acid is the most commonly used acid for etching before bonding. Nitric acid is also commercially available for etching enamel; however, it has not been studied specifically for etching in orthodontic bonding. This ex vivo study compared the enamel etch patterns achieved on the orthodontic bonding area of extracted mandibular premolars treated with 37% wt/wt phosphoric acid and 2.5% wt/wt nitric acid applied for 15, 30, or 60 seconds. The etch patterns were viewed with a scanning electron microscope and assessed with a 5-point etch scale. Statistical analysis showed that increasing the duration of acid application (irrespective of acid type) significantly increased the amount of better quality etch. Phosphoric acid at 37% concentration was more effective at producing a good-quality etch than was nitric acid at 2.5% for all 3 application times. The quantity of good-quality etch produced by phosphoric acid at 37% was time specific, with 15 seconds being significantly less effective than 30 or 60 seconds. However, 60 seconds was not significantly better than 30. Comparing the upper half of the orthodontic bonding area with the lower half showed no statistically significant differences for either acid type or length of application (P >.005). These findings support the use of 37% wt/wt phosphoric acid and indicate an optimum application time of 30 seconds.
Assuntos
Condicionamento Ácido do Dente/métodos , Esmalte Dentário/efeitos dos fármacos , Ácido Nítrico/administração & dosagem , Ácidos Fosfóricos/administração & dosagem , Adolescente , Análise de Variância , Dente Pré-Molar/efeitos dos fármacos , Dente Pré-Molar/ultraestrutura , Criança , Colagem Dentária , Esmalte Dentário/ultraestrutura , Feminino , Humanos , Modelos Lineares , Masculino , Mandíbula , Microscopia Eletrônica de Varredura , Braquetes Ortodônticos , Reprodutibilidade dos Testes , Estatística como Assunto , Estresse Mecânico , Fatores de TempoRESUMO
During nitric oxide (NO) inhalation therapy, NO combines with deoxyhemoglobin to form nitrosyl hemoglobin (HbNO). We used electron spin resonance (ESR) spectroscopy to measure HbNO in arterial and mixed venous blood of normoxic and hypoxic sheep during NO inhalation. Our aim was to quantitatively measure HbNO levels in the blood during NO inhalation, because large amounts of HbNO reduce the oxygen capacity of blood, particularly in hypoxia. Another aim was to investigate the transfer of exogenous NO to the alpha-heme iron of hemoglobin. Thirteen sheep were anesthetized with pentobarbital sodium, and 60 parts per million (ppm) NO were administered for 1 h in the presence of normoxia and hypoxia. Two-way analysis of variance revealed that the HbNO level was dependent on the oxygen level (normoxia vs. hypoxia) and NO inhalation, and there was a significant negative correlation between the HbNO level and arterial O2 saturation (SaO2). Although the HbNO level increased during NO inhalation in hypoxia, the HbNO level at SaO2 > 60% was < 11 mumol/l monomer hemoglobin (0.11% of total 10 mmol/l monomer hemoglobin). The peak of the HbNO ESR spectrum in arterial blood is located in almost the same position in mixed venous blood with an asymmetric HbNO signal, indicating that the NO in beta-heme HbNO molecules had been transferred to alpha-heme molecules. The three-line hyperfine structure of HbNO on ESR spectra was distinct in venous blood in hypoxia during NO inhalation, indicating pentacoordinate alpha-NO heme formation in hypoxic blood. In conclusion, the amount of HbNO during 60 ppm NO inhalation did not considerably reduce the oxygen capacity of the blood even in the presence of hypoxia, and the NO of HbNO was transferred to the alpha-heme iron of hemoglobin, forming pentacoordinate alpha-NO heme in mixed venous blood in hypoxia.
Assuntos
Hemodinâmica/efeitos dos fármacos , Hemoglobinas/metabolismo , Hipóxia/sangue , Ácido Nítrico/farmacologia , Ácido Nítrico/farmacocinética , Administração por Inalação , Análise de Variância , Animais , Pressão Sanguínea/efeitos dos fármacos , Dióxido de Carbono/sangue , Débito Cardíaco/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Hemodinâmica/fisiologia , Ácido Nítrico/administração & dosagem , Oxigênio/sangue , Pressão Parcial , Valores de Referência , Ovinos , Fatores de Tempo , Resistência Vascular/efeitos dos fármacosRESUMO
We report a case of acute inhalation injury of nitric acid in a 56-year old white male. The patient presented conscious and dyspnoic at the emergency department after cleaning a copper chandelier with nitric acid. He had to be intubated 2 h after admission and mechanically ventilated because of fulminant respiratory insufficiency. As all sources of mechanical ventilation failed, extracorporeal membrane oxygenation had to be established 7 h after admission. With the additional use of surfactant and low dose inhalation therapy with nitric oxide (NO), the patient could be stabilised for 3 days and lung function improved temporarily. Despite all efforts the patient died at the fourth day from refactory respiratory failure. Pathologic examination revealed massive pulmonary edema without signs of inflammation. Thus, nitric acid inhalation induced pulmonary edema appears to be a most severe situation in which even most modern therapeutic interventions fail. As, in respect of recent literature and our case no promising therapy for nitric acid inhalation pulmonary edema is available, our efforts have to be directed towards prevention of nitric acid exposure.
Assuntos
Produtos Biológicos , Ácido Nítrico/intoxicação , Fosfolipídeos , Edema Pulmonar/induzido quimicamente , Acidentes Domésticos , Administração por Inalação , Oxigenação por Membrana Extracorpórea , Evolução Fatal , Humanos , Masculino , Pessoa de Meia-Idade , Ácido Nítrico/administração & dosagem , Óxido Nítrico/uso terapêutico , Edema Pulmonar/terapia , Surfactantes Pulmonares/uso terapêutico , Respiração ArtificialRESUMO
The ability of urban oxidant and acid air pollutants to induce heat shock proteins (HSPs) in the mammalian lung is not known. Such proteins are known to be correlated with environmental stress and pathophysiological conditions. In this study, stress-inducible HSP 70 was assessed by slot-blotting in rat lungs (N=10 per group) following inhalation exposures for 4 h per day, 3 days per week for 40 weeks to the following pollutants: (a) purified air;(b) 0.15 ppm ozone (O3);(c)50 micrograms/m3 nitric acid (HNO3); or(d) a combination of both 0.15 ppm O3 and 50 micrograms/m3 HNO3. At 24 h following the last exposure, samples from the right apical lobe of the lung were obtained for either slot-blotting or gel electrophoretic separation, subsequent protein immunoblotting, and chemiluminescence detection of HSP 70 levels. Experiments demonstrate that stress-inducible HSP 70 was present constitutively in the control lungs and was separable from the constitutive form of HSP 70. Slot-blotting analysis demonstrate that the O3 and HNO3 exposures alone produced significant elevations of HSP70. Specifically, either O3 or HNO3 alone significantly elevated lung stress-inducible HSP 70 levels by 277% and 221% respectively, above control levels. The group exposed to combined O3 and HNO3 showed a 177% elevation in lung stress-inducible HSP 70 that was significantly greater that the group inhaling purified air, but this effect was less than the effects of either pollutant component alone. Moreover, all exposure groups were significantly different from one another. These results indicate that stress-inducible HSP 70 in the rat lung is highly elevated after chronic inhalation exposures to both O3 and HNO3 when administered either alone or in combination within the range of urban ambient concentrations.
Assuntos
Poluentes Atmosféricos/toxicidade , Proteínas de Choque Térmico HSP70/biossíntese , Pulmão/metabolismo , Ácido Nítrico/toxicidade , Oxidantes Fotoquímicos/toxicidade , Ozônio/toxicidade , Administração por Inalação , Animais , Eletroforese em Gel de Poliacrilamida , Proteínas de Choque Térmico HSP72 , Proteínas de Choque Térmico/análise , Proteínas de Choque Térmico/isolamento & purificação , Imunoensaio , Pulmão/química , Pulmão/efeitos dos fármacos , Masculino , Ácido Nítrico/administração & dosagem , Oxidantes Fotoquímicos/administração & dosagem , Ozônio/administração & dosagem , Ratos , Ratos Endogâmicos F344RESUMO
This in-vitro study evaluated the effectiveness of six different enamel treatment procedures for bonding a dental sealant. Sixty extracted human molar teeth were separated into the following enamel treatment groups (10 teeth each): group 1 (control)-etched with 37% phosphoric acid; group 2-air polished (air abraded) with 45 microns particles of sodium bicarbonate; group 3-air abraded with 50 microns aluminum oxide particles; group 4-etched with 2.5% nitric acid; group 5-air abraded with sodium bicarbonate particles and etched with 37% phosphoric acid; and group 6-air abraded with 50-microns aluminum oxide particles and etched with 37% phosphoric acid. The enamel treatment procedures were accomplished on intact mesial or distal surfaces. Following the enamel treatment, a sealant was bonded to the surfaces using a plastic matrix technique. After 24 hr of water storage at 37 degrees C, the specimens were debonded using an Instron machine. The mean shear bond strengths (MPa) were as follows: group 1-9.19 +/- 1.34 MPa; group 2-2.03 +/- 1.67 MPa; group 3-1.50 +/- 0.93 MPa; group 4-4.99 +/- 1.26 MPa; group 5-11.61 +/- 4.51; and group 6-11.14 +/- 1.70 MPa. Statistical analysis using a one-way ANOVA and Scheffe F-test revealed no significant difference (P > 0.05) among groups 1,5, and 6. However, there was a significant difference (P < 0.05) between groups 1,5, and 6 and the other three groups (2,3, and 4). In conclusion, 37% phosphoric acid treatment of intact enamel, or a combination of air abrasion with sodium bicarbonate or aluminum oxide followed by phosphoric acid, provides significantly higher bond strengths of a sealant material than enamel conditioning with 2.5% nitric acid or air abrasion with sodium bicarbonate or aluminum oxide.
Assuntos
Colagem Dentária/métodos , Esmalte Dentário/ultraestrutura , Selantes de Fossas e Fissuras/química , Condicionamento Ácido do Dente/métodos , Ar , Óxido de Alumínio/administração & dosagem , Análise de Variância , Descolagem Dentária , Análise do Estresse Dentário/instrumentação , Humanos , Ácido Nítrico/administração & dosagem , Ácidos Fosfóricos/administração & dosagem , Plásticos , Bicarbonato de Sódio/administração & dosagem , Estresse Mecânico , ÁguaRESUMO
Both peak flow decrements in children at summer camps and increased hospital admissions for asthma have been associated with summer "acid haze," which is composed of ozone and various acidic species. The objective of this study was to investigate the pulmonary effects of acid summer haze in a controlled laboratory setting. Twenty-eight adolescent subjects with allergic asthma, exercise-induced bronchospasm, and a positive response to a standardized methacholine challenge enrolled in the study; 22 completed the study. Each subject inhaled one of four test atmospheres by mouthpiece on two consecutive days. The order of exposure to the four test atmospheres was assigned via a random protocol: air, oxidants (0.12 parts per million [ppm]* ozone plus 0.30 ppm nitrogen dioxide), oxidants plus sulfuric acid at 70 micrograms/m3 of air, or oxidants plus 0.05 ppm nitric acid. Exposure to each of the different atmospheres was separated by at least one week. The exposures were carried out during alternating 15-minute periods of rest and moderate exercise for a total exposure period of 90 minutes per day. Pulmonary function was measured before and after exposure on both test days and again on the third day as a follow-up measurement. A postexposure methacholine challenge was performed on Day 3. Low methacholine concentrations were chosen for the postexposure challenge to avoid provoking a response. The protocol was designed to detect subtle changes in airway reactivity. The statistical significance of the pulmonary function values was tested using paired t tests. First, we compared the difference between baseline and postexposure measurements after air exposure on Day 1 with the differences between baseline and postexposure measurements after Day 1 exposure to each of the other three atmospheres. Second, we compared the difference between baseline and postexposure measurements after the Day 2 air exposure with the differences between baseline and postexposure measurements after the Day 2 exposure to each of the pollutant atmospheres. Third, we compared the difference between baseline measurements on Day 1 of each exposure atmosphere with measurements after exposure to the same atmosphere on Day 2 to detect delayed effects. No changes in any of the pulmonary function parameters were statistically significant when compared with changes after clean air exposure. Six subjects left the study because of uncomfortable symptoms associated with the exposures. These all occurred after exposure to pollutant atmospheres and not after exposure to clean air.(ABSTRACT TRUNCATED AT 400 WORDS)