Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
1.
Small ; 20(2): e2306020, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37661358

RESUMO

To date, all-inorganic lead halide perovskite quantum dots have emerged as promising materials for photonic, optoelectronic devices, and biological applications, especially in solar cells, raising numerous concerns about their biosafety. Most of the studies related to the toxicity of perovskite quantum dots (PeQDs) have focused on the potential risks of hybrid perovskites by using zebrafish or human cells. So far, the neurotoxic effects and fundamental mechanisms of PeQDs remain unknown. Herein, a comprehensive methodology is designed to investigate the neurotoxicity of PeQDs by using Caenorhabditis elegans as a model organism. The results show that the accumulation of PeQDs mainly focuses on the alimentary system and head region. Acute exposure to PeQDs results in a decrease in locomotor behaviors and pharyngeal pumping, whereas chronic exposure to PeQDs causes brood decline and shortens lifespan. In addition, some abnormal issues occur in the uterus during reproduction assays, such as vulva protrusion, impaired eggs left in the vulva, and egg hatching inside the mother. Excessive reactive oxygen species formation is also observed. The neurotoxicity of PeQDs is explained by gene expression. This study provides a complete insight into the neurotoxicity of PeQD and encourages the development of novel nontoxic PeQDs.


Assuntos
Compostos Inorgânicos , Nanopartículas , Óxidos , Titânio , Humanos , Feminino , Animais , Caenorhabditis elegans , Peixe-Zebra , Compostos de Cálcio/toxicidade , Nanopartículas/toxicidade
2.
Angew Chem Int Ed Engl ; 60(13): 6955-6959, 2021 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-33624929

RESUMO

Light-harvesting and conversion ability is important to promote plant growth, and especially when resources are limited. A near-infrared (NIR) nanophosphor embedded with mesoporous silica nanoparticles (MSN), ZnGa2 O4 :Cr3+ ,Sn4+ (ZGOCS), was developed and its optical properties were harnessed to enhance the photosynthetic ability of Brassica rapa spp. chinensis. The broad excitation of ZGOCS from the ultraviolet to the visible region allowed the conversion of extra light into near-infrared light (650-800 nm) and thus promoted the dual photosystem via the Emerson effect. ZGOCS@MSN was spherical with a size of 65±10 nm and good dispersion. A light conversion ability of up to 75 % under different wavelengths was achieved. Moreover, the electron transfer rate of photosynthesis increased by 100 % with a suitable ZGOCS@MSN concentration. Plant and animal models were used to explore the effects of the nanophosphor. ZGOCS@MSN distribution was tracked by monitoring its NIR emission in plant and animal tissues, demonstrating that this nanophosphor can be potentially utilized in plant growth.


Assuntos
Complexos de Proteínas Captadores de Luz/metabolismo , Nanopartículas/metabolismo , Dióxido de Silício/metabolismo , Animais , Raios Infravermelhos , Complexos de Proteínas Captadores de Luz/química , Camundongos , Nanopartículas/química , Tamanho da Partícula , Plantas/efeitos dos fármacos , Plantas/metabolismo , Porosidade , Dióxido de Silício/química , Propriedades de Superfície
3.
Ann Clin Microbiol Antimicrob ; 16(1): 52, 2017 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-28738848

RESUMO

BACKGROUND: We assessed the influence of current cefepime minimal inhibitory concentration (MIC) breakpoints and the maximal cefepime dose on treatment outcomes in patients with bacteremia caused by cefepime-susceptible Pseudomonas aeruginosa. METHODS: Adult patients hospitalized between July 2010 and June 2014 with a positive blood culture for cefepime-susceptible P. aeruginosa and receipt of cefepime as the primary therapy throughout the course were reviewed. Cefepime Etest® MICs and clinical outcomes for P. aeruginosa bacteremia were reviewed to identify the MIC breakpoint influencing treatment outcomes. RESULTS: Of the 90 patients enrolled, 49 (54.4%) were male (mean age = 66.8 years). The mean Acute Physiology and Chronic Health Evaluation II score was 22.01. Sixty patients (66.7%) received a maximal cefepime dose, and the 30-day crude mortality rate was 36.7%. MIC90 of cefepime for P. aeruginosa was 8 mg/L. The cumulative survival rate at 30 days revealed that a lower cefepime MIC (<4 mg/L) for P. aeruginosa was associated with a higher survival rate than a higher MIC (≥4 mg/L) (72.6% vs. 23.5%, p < 0.0001). A cefepime MIC of ≥4 mg/L and age were independent risk factors for mortality, whereas the maximal cefepime dose was the independent protective factor. The use of a maximal cefepime dose did not improve the outcomes of patients with P. aeruginosa bacteremia at a MIC of ≥4 mg/L. CONCLUSIONS: A cefepime MIC of 4 mg/L may predict an unfavorable outcome among patients with serious infections caused by P. aeruginosa, even the MICs still within the CLSI susceptibility breakpoint.


Assuntos
Antibacterianos/administração & dosagem , Bacteriemia/tratamento farmacológico , Cefalosporinas/administração & dosagem , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Adulto , Idoso , Idoso de 80 Anos ou mais , Bacteriemia/microbiologia , Cefepima , Relação Dose-Resposta a Droga , Feminino , Hospitais/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/fisiologia , Estudos Retrospectivos , Resultado do Tratamento
4.
J Chin Med Assoc ; 86(1): 122-130, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36306391

RESUMO

BACKGROUND: The World Health Organization reported that cardiovascular disease is the most common cause of death worldwide. On average, one person dies of heart disease every 26 min worldwide. Deep learning approaches are characterized by the appropriate combination of abnormal features based on numerous annotated images. The constructed convolutional neural network (CNN) model can identify normal states of reversible and irreversible myocardial defects and alert physicians for further diagnosis. METHODS: Cadmium zinc telluride single-photon emission computed tomography myocardial perfusion resting-state images were collected at Chang Gung Memorial Hospital, Kaohsiung Medical Center, Kaohsiung, Taiwan, and were analyzed with a deep learning convolutional neural network to classify myocardial perfusion images for coronary heart diseases. RESULTS: In these grey-scale images, the heart blood flow distribution was the most crucial feature. The deep learning technique of You Only Look Once was used to determine the myocardial defect area and crop the images. After surrounding noise had been eliminated, a three-dimensional CNN model was used to identify patients with coronary heart diseases. The prediction area under the curve, accuracy, sensitivity, and specificity was 90.97, 87.08, 86.49, and 87.41%, respectively. CONCLUSION: Our prototype system can considerably reduce the time required for image interpretation and improve the quality of medical care. It can assist clinical experts by offering accurate coronary heart disease diagnosis in practice.


Assuntos
Doença da Artéria Coronariana , Aprendizado Profundo , Isquemia Miocárdica , Imagem de Perfusão do Miocárdio , Humanos , Imagem de Perfusão do Miocárdio/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Isquemia Miocárdica/diagnóstico por imagem , Coração
5.
ACS Appl Mater Interfaces ; 15(27): 32589-32596, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37364173

RESUMO

The rapid change in population, environment, and climate is accompanied by the food crisis. As a new type of farming, indoor agriculture opens the possibility of addressing this crisis in the future. In this study, a phosphor-converted light-emitting diode (pc-LED), as energy-saving lighting for indoor agriculture, was used to evaluate the response and effect on the growth of Lactuca sativa. Red phosphors, SrLiAl3N4:Eu2+ (SLA) and CaAlSiN3:Eu2+ (CASN), were characterized and analyzed with crystal structure, morphology, and optical properties. Eu2+-doped phosphors provided the red emission of around 650 nm which is highly matched with the absorption of chlorophyll. Under the same luminescence intensity, broader emission of CASN pc-LED demonstrated a 100% increase of photosynthetically active photon flux density and 130% promotion of plant weight than the SLA pc-LED, which reflected the positive result of the carbon fixation. The chlorophyll and nitrate responses have also revealed the effect of broader red light on indoor agriculture.

6.
Nanoscale ; 15(38): 15558-15572, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37721121

RESUMO

Single-atom nanozymes (SANs) are the latest trend in biomaterials research and promote the application of single atoms in biological fields and the realization of protein catalysis in vivo with inorganic nanoparticles. Carbon quantum dots (CDs) have excellent biocompatibility and fluorescence properties as a substrate carrying a single atom. It is difficult to break through pure-phase single-atom materials with quantum dots as carriers. In addition, there is currently no related research in the single-atom field in the context of oral cancer, especially head and neck squamous cell carcinoma. This research developed a lipid surface-coated nanozyme combined with CDs, single-atomic gold, and modified lipid ligands (DSPE-PEG) with transferrin (Tf) to treat oral squamous cell carcinoma. The study results have demonstrated that surface-modified single-atom carbon quantum dots (m-SACDs) exhibit excellent therapeutic effects and enable in situ image tracking for diagnosing and treating head and neck squamous carcinoma (HNSCC).


Assuntos
Carcinoma de Células Escamosas , Neoplasias Bucais , Fotoquimioterapia , Humanos , Carcinoma de Células Escamosas/patologia , Neoplasias Bucais/tratamento farmacológico , Carbono/química , Estresse Oxidativo , Lipídeos/química
7.
Pharmaceutics ; 14(2)2022 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-35214188

RESUMO

The most common malignant tumor of the brain is glioblastoma multiforme (GBM) in adults. Many patients die shortly after diagnosis, and only 6% of patients survive more than 5 years. Moreover, the current average survival of malignant brain tumors is only about 15 months, and the recurrence rate within 2 years is almost 100%. Brain diseases are complicated to treat. The reason for this is that drugs are challenging to deliver to the brain because there is a blood-brain barrier (BBB) protection mechanism in the brain, which only allows water, oxygen, and blood sugar to enter the brain through blood vessels. Other chemicals cannot enter the brain due to their large size or are considered harmful substances. As a result, the efficacy of drugs for treating brain diseases is only about 30%, which cannot satisfy treatment expectations. Therefore, researchers have designed many types of nanoparticles and nanocomposites to fight against the most common malignant tumors in the brain, and they have been successful in animal experiments. This review will discuss the application of various nanocomposites in diagnosing and treating GBM. The topics include (1) the efficient and long-term tracking of brain images (magnetic resonance imaging, MRI, and near-infrared light (NIR)); (2) breaking through BBB for drug delivery; and (3) natural and chemical drugs equipped with nanomaterials. These multifunctional nanoparticles can overcome current difficulties and achieve progressive GBM treatment and diagnosis results.

8.
Nanoscale ; 14(19): 7123-7136, 2022 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-35353112

RESUMO

Research in the field of nano-optics is advancing by leaps and bounds, among which near-infrared (NIR) light optics have attracted much attention. NIR light has a longer wavelength than visible light, such that it can avoid shielding caused by biological tissues. This advantage has driven its importance and practicality in human treatment applications and has attracted significant attention from researchers in academia and industry. In the broad spectrum of infrared light wavelengths, the most noticeable ones are the NIR biological window I of 700-900 nm and window II of 1000-1700 nm. Luminescent materials can effectively cover the NIR biological window with different doping strategies. These doped elements are mostly transition elements with multielectron orbitals. Several nanomaterials based on narrow-spectrum lanthanides have been developed to correspond to biological applications of different wavelengths. However, this review explicitly introduces the absorption and reflection/luminescence interactions between NIR light and biological tissues independently. Unlike the adjustment of the wavelength of the lanthanide series, this review analyzes the NIR optical properties of the fourth-period element ions in transition elements (such as Cr3+ and Ni2+). These elements have a broadband wavelength of NIR light emission and higher quantum efficiency, corresponding to the absorption and emission spectrum and photobiological absorption of different NIR windows for therapeutic diagnosis. Finally, this review lists and explores other broadband NIR phosphors and has tried to discover the possibility of non-invasive precision medicine in the future.


Assuntos
Elementos da Série dos Lantanídeos , Elementos de Transição , Humanos , Raios Infravermelhos , Luminescência , Medicina de Precisão
9.
Sci Rep ; 10(1): 17374, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33060702

RESUMO

Acute lower respiratory infection is the leading cause of child death in developing countries. Current strategies to reduce this problem include early detection and appropriate treatment. Better diagnostic and therapeutic strategies are still needed in poor countries. Artificial-intelligence chest X-ray scheme has the potential to become a screening tool for lower respiratory infection in child. Artificial-intelligence chest X-ray schemes for children are rare and limited to a single lung disease. We need a powerful system as a diagnostic tool for most common lung diseases in children. To address this, we present a computer-aided diagnostic scheme for the chest X-ray images of several common pulmonary diseases of children, including bronchiolitis/bronchitis, bronchopneumonia/interstitial pneumonitis, lobar pneumonia, and pneumothorax. The study consists of two main approaches: first, we trained a model based on YOLOv3 architecture for cropping the appropriate location of the lung field automatically. Second, we compared three different methods for multi-classification, included the one-versus-one scheme, the one-versus-all scheme and training a classifier model based on convolutional neural network. Our model demonstrated a good distinguishing ability for these common lung problems in children. Among the three methods, the one-versus-one scheme has the best performance. We could detect whether a chest X-ray image is abnormal with 92.47% accuracy and bronchiolitis/bronchitis, bronchopneumonia, lobar pneumonia, pneumothorax, or normal with 71.94%, 72.19%, 85.42%, 85.71%, and 80.00% accuracy, respectively. In conclusion, we provide a computer-aided diagnostic scheme by deep learning for common pulmonary diseases in children. This scheme is mostly useful as a screening for normal versus most of lower respiratory problems in children. It can also help review the chest X-ray images interpreted by clinicians and may remind possible negligence. This system can be a good diagnostic assistance under limited medical resources.


Assuntos
Aprendizado Profundo , Pneumopatias/diagnóstico por imagem , Radiografia Torácica , Criança , Diagnóstico por Computador , Diagnóstico Diferencial , Humanos , Sensibilidade e Especificidade
10.
J Microbiol Immunol Infect ; 53(2): 191-208, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32169531

RESUMO

Clostridioides difficile infection (CDI) is a major enteric disease associated with antibiotic use and a leading cause of hospital-acquired infections worldwide. This is the first guideline for treatment of CDI in Taiwan, aiming to optimize medical care for patients with CDI. The target audience of this document includes all healthcare personnel who are involved in the medical care of patients with CDI. The 2018 Guidelines Recommendations for Evidence-based Antimicrobial agents use in Taiwan (GREAT) working group was formed, comprising of infectious disease specialists from 13 medical centers in Taiwan, to review the evidence and draft recommendations using the grading of recommendations assessment, development, and evaluation (GRADE) methodology. A nationwide expert panel reviewed the recommendations during a consensus meeting in March 2019. The recommendation is endorsed by the Infectious Diseases Society of Taiwan (IDST). This guideline describes the epidemiology and risk factors of CDI, and provides recommendations for treatment of CDI in both adults and children. Recommendations for treatment of the first episode of CDI, first recurrence, second and subsequent recurrences of CDI, severe CDI, fulminant CDI, and pediatric CDI are provided.


Assuntos
Antibacterianos/uso terapêutico , Infecções por Clostridium/tratamento farmacológico , Guias como Assunto , Adulto , Criança , Clostridioides difficile/efeitos dos fármacos , Infecções por Clostridium/epidemiologia , Infecção Hospitalar/epidemiologia , Bases de Dados Factuais , Diarreia/tratamento farmacológico , Diarreia/microbiologia , Humanos , Fatores de Risco , Taiwan/epidemiologia
11.
Front Mol Biosci ; 6: 54, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31355208

RESUMO

Prions in eukaryotes have been linked to diseases, evolutionary capacitance, large-scale genetic control, and long-term memory formation. Prion formation and propagation have been studied extensively in the budding yeast Saccharomyces cerevisiae. Here, we have analysed the conservation of sequence and of prion-like composition for prion-forming proteins and for other prion-like proteins from S. cerevisiae, across three evolutionary levels. We discover that prion-like status is well-conserved for about half the set of prion-formers at the Saccharomycetes level, and that prion-forming domains evolve more quickly as sequences than other prion-like domains do. Such increased mutation rates may be linked to the acquisition of functional roles for prion-forming domains during the evolutionary epoch of Saccharomycetes. Domain scores for prion-like composition in S. cerevisiae are strongly correlated with scores for such composition weighted evolutionarily over the dozens of fungal species examined, indicating conservation of such prion-like status. Examples of notable prion-like proteins that are highly conserved both in sequence and prion-like composition are discussed.

12.
Am J Chin Med ; 47(6): 1271-1287, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31488035

RESUMO

Dendritic cells (DCs) play a critical role in initiating immune responses; however, DCs also induce Th2-related allergic sensitivities. Thus, DCs become a target for therapeutic design in allergic diseases. In this study, we aim to investigate the anti-allergic effect of pure compounds from a medicinal mushroom Antrodia cinnamomea (Ac) on DC-induced allergic responses. We identified a benzenoid compound 4,7-dimethoxy-5-methyl-l,3-benzodioxole (DMB) which may modulate Th2 polarization in bone marrow-derived DCs (BMDCs) and in a murine food allergy model. DMB effectively reduced the Th2 adjuvant cholera toxin (CT)-induced BMDC maturation and cytokine production. In studying the mechanism, DMB blocked the molecular processes involved in Th2 induction, including cAMP activation, IL-33 production, and IRF4/Tim4 upregulation, in CT-activated BMDCs. Furthermore, DMB treatment attenuated the symptoms, clinical scores, and Th2 responses of CT-induced ovalbumin (OVA)-specific food allergy in mice at sensitization stage. These results indicated that DMB could suppress DC function for Th2 polarization and mitigate allergic responses. Thus, DMB may have potential to be a novel agent for preventing or treating food allergy.


Assuntos
Antialérgicos , Antrodia/química , Benzodioxóis/farmacologia , Benzodioxóis/uso terapêutico , Células Dendríticas/imunologia , Hipersensibilidade Alimentar/tratamento farmacológico , Hipersensibilidade/tratamento farmacológico , Fitoterapia , Células Th2/imunologia , Animais , Células Cultivadas , Citocinas/metabolismo , Modelos Animais de Doenças , Hipersensibilidade Alimentar/imunologia , Hipersensibilidade Alimentar/prevenção & controle , Camundongos Endogâmicos BALB C , Ovalbumina/imunologia
13.
J Hazard Mater ; 154(1-3): 73-8, 2008 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-18006225

RESUMO

In the work, the beer brewery waste has been shown to be a low-cost adsorbent for the removal of basic dye from the aqueous solution as compared to its precursor (i.e., diatomite) based on its physical and chemical characterizations including surface area, pore volume, scanning electron microscopy (SEM), and non-mineral elemental analyses. The pore properties of this waste were significantly larger than those of its raw material, reflecting that the trapped organic matrices contained in the waste probably provided additional adsorption sites and/or adsorption area. The results of preliminary adsorption kinetics showed that the diatomite waste could be directly used as a potential adsorbent for removal of methylene blue on the basis of its adsorption-biosorption mechanisms. The adsorption parameters thus obtained from the pseudo-second-order model were in accordance with their pore properties. From the results of adsorption isotherm at 298 K and the applicability examinations in treating industrial wastewater containing basic dye, it was further found that the adsorption capacities of diatomite waste were superior to those of diatomite, which were also in good agreement with their corresponding physical properties. From the results mentioned above, it is feasible to utilize the food-processing waste for removing dye from the industrial dying wastewater.


Assuntos
Cerveja , Corantes/química , Terra de Diatomáceas/química , Azul de Metileno/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Indústria Alimentícia , Resíduos Industriais , Cinética
14.
Medicine (Baltimore) ; 97(50): e13607, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30558035

RESUMO

The accuracy of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for identifying viridans group streptococcus (VGS) was improving. However, the clinical impact of identifying VGS had not been well recognized. Our study had comprehensively studied the clinical manifestations and outcome of VGS blood stream infection by using MALDI-TOF MS for identification.This retrospective study enrolled 312 adult patients with a monomicrobial blood culture positive for VGS. Blood culture was examined through MALDI-TOF MS.The most common VGS species were the Streptococcus anginosus group (38.8%) and Streptococcus mitis group (22.8%). Most species showed resistance to erythromycin (35.6%), followed by clindamycin (25.3%) and penicillin (12.5%). Skin and soft tissue infection and biliary tract infection were significantly related to S. anginosus group bacteremia (P = .001 and P = .005, respectively). S. mitis group bacteremia was related to infective endocarditis and bacteremia with febrile neutropenia (P = .005 and P < .001, respectively). Infective endocarditis was also more likely associated with S. sanguinis group bacteremia (P = .009). S. anginosus group had less resistance rate to ampicillin, erythromycin, clindamycin, and ceftriaxone (P = .019, <.001, .001, and .046, respectively). A more staying in intensive care unit, underlying solid organ malignancy, and a shorter treatment duration were independent risk factors for 30-day mortality. This study comprehensively evaluated different VGS group and their clinical manifestations, infection sources, concomitant diseases, treatments, and outcomes. Categorizing VGS into different groups by MALDI-TOF MS could help clinical physicians well understand their clinical presentations.


Assuntos
Bacteriemia/etiologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Estreptococos Viridans/patogenicidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Bacteriemia/epidemiologia , Bacteriemia/mortalidade , Hemocultura/métodos , Hemocultura/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/estatística & dados numéricos , Infecções Estreptocócicas/complicações , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/mortalidade , Taiwan/epidemiologia , Estreptococos Viridans/crescimento & desenvolvimento
15.
J Hazard Mater ; 147(3): 1056-62, 2007 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-17363150

RESUMO

The adsorption of cationic dye (i.e., methylene blue) onto acid-activated andesite in aqueous solution was studied in a batch system with respect to its kinetics as a function of agitation speed, initial adsorbate concentration, pH, and adsorbent mass. It was found that the resulting acid-activated adsorbent possessed a mesoporous structure with BET surface areas at around 60m(2)/g. The surface characterization of acid-activated andesite was also performed using the zeta-potential measurements, indicating that the charge sign on the surface of the andesite should be negative in a wide pH range (i.e., 3-11). Furthermore, a simplified kinetic model, pseudo-second-order, was tested to investigate the adsorption behaviors of methylene blue onto the clay samples treated under different process conditions. It was found that the adsorption process could be well described with the model. The adsorption capacity parameter of the model obtained in the present work was significantly in line with the process parameters.


Assuntos
Silicatos de Alumínio/química , Corantes/química , Resíduos Industriais , Azul de Metileno/química , Quartzo/química , Poluentes Químicos da Água/química , Adsorção , Argila , Concentração de Íons de Hidrogênio , Cinética , Soluções , Fatores de Tempo
16.
J Microbiol Immunol Infect ; 50(5): 677-683, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26188977

RESUMO

BACKGROUND/PURPOSE: Carbapenem-resistant Pseudomonas aeruginosa infections have been a challenge and issue in hospital settings. However, the clinical impact of P. aeruginosa blood isolates resistant only to carbapenems has never been discussed previously. METHODS: To assess the risk factors and clinical significance of bacteremia caused by carbapenem resistance only P. aeruginosa (CROPA), a 6-year retrospective case-control study was conducted. The CROPA strains were defined as isolates susceptible to ciprofloxacin, antipseudomonal penicillins and cephalosporins, and aminoglycosides but resistant to one antipseudomonal carbapenem (imipenem or meropenem) or both. The controls were selected among patients with bacteremia due to P. aeruginosa susceptible to all above classes of antipseudomonal antibiotics, which was defined as all-susceptible P. aeruginosa. RESULTS: Twenty-five patients had at least one blood culture positive for CROPA, and 50 controls had all-susceptible P. aeruginosa bacteremia. CROPA bacteremia had a high 30-day mortality rate (72.0%), as compared to 26.0% for the controls (p < 0.001). Through multivariate analysis, carbapenem exposure was the only risk factor for developing CROPA bacteremia (p = 0.002). A comparison between the surviving and deceased patients with CROPA bacteremia showed that nine (50%) of those who died, but none of the survivors, received carbapenems as the initial empirical therapy (p = 0.027). CONCLUSION: Carbapenem exposure was associated with emergence of CROPA infections. Repeated carbapenem use in such patients might increase rates of inappropriate initial empirical treatment and mortality. Prudent carbapenem use is important to reduce the emergence of CROPA.


Assuntos
Antibacterianos/farmacologia , Bacteriemia/tratamento farmacológico , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Carbapenêmicos/farmacologia , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Adulto , Idoso , Aminoglicosídeos/farmacologia , Bacteriemia/microbiologia , Bacteriemia/mortalidade , Hemocultura , Enterobacteriáceas Resistentes a Carbapenêmicos/patogenicidade , Estudos de Casos e Controles , Cefalosporinas/farmacologia , Ciprofloxacina/farmacologia , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/microbiologia , Feminino , Hospitais , Humanos , Imipenem/farmacologia , Masculino , Meropeném , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Mortalidade , Análise Multivariada , Razão de Chances , Penicilinas/farmacologia , Infecções por Pseudomonas/sangue , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/mortalidade , Pseudomonas aeruginosa/isolamento & purificação , Pseudomonas aeruginosa/patogenicidade , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Taiwan , Tienamicinas/farmacologia
17.
J Colloid Interface Sci ; 299(2): 513-9, 2006 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-16631189

RESUMO

The adsorption behavior of bisphenol-A, which is a hydrophobic organic compound and also listed as one of endocrine disrupting chemicals, from aqueous solution onto hydrophobic zeolite at 25 degrees C have been studied using a batch adsorption process in terms of a pseudo-second-order equation and three common isotherms (i.e., the Langmuir, Freundlich, and Redlich-Peterson). The pore properties of the Y-type zeolite have been determined using N2 adsorption-desorption isotherms, indicating that it is a supermicroporous adsorbent associated with a lower percentage of mesopores. Based on the kinetic model the effects of particle size, initial bisphenol-A concentration, initial solution pH, and adsorbent dosage on the adsorption rate constant and equilibrium capacity have been estimated, showing that the adsorption process could be simulated well by the simplified kinetic model. From the data on the equilibrium adsorption capacities obtained by fitting the pseudo-second-order model, the adsorption isotherm could be better described by the three-parameter Redlich-Peterson model than by the two-parameter models (i.e., the Langmuir and Freundlich).


Assuntos
Poluentes Ocupacionais do Ar , Fenóis , Zeolitas , Adsorção , Compostos Benzidrílicos , Poluição Ambiental , Cinética , Soluções , Propriedades de Superfície , Água
18.
J Hazard Mater ; 134(1-3): 169-75, 2006 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-16343748

RESUMO

The adsorption behaviors of bisphenol-A, which has been listed as one of endocrine disrupting chemicals, from aqueous solution onto four minerals including andesite, diatomaceous earth, titanium dioxide, and activated bleaching earth, and two activated carbons with coconut-based and coal-based virgins were examined in this work. Based on the adsorption results at the specified conditions, the adsorption capacities of activated carbons are significantly larger than those of mineral adsorbents, implying that the former is effective for removal of the highly hydrophobic adsorbate from the aqueous solution because of its high surface area and low surface polarity. The adsorption capacities of bisphenol-A onto these mineral adsorbents with different pore properties are almost similar in magnitude mainly due to the weakly electrostatic interaction between the mineral surface with negative charge and the target adsorbate with hydrophobic nature. Further, a simplified kinetic model, pseudo-second-order, was tested to investigate the adsorption behaviors of bisphenol-A onto the two common activated carbons at different solution conditions. It was found that the adsorption process could be well described with the pseudo-second-order model. The kinetic parameters of the model obtained in the present work are in line with the pore properties of the two adsorbents.


Assuntos
Carbono/química , Minerais/química , Fenóis/química , Adsorção , Compostos Benzidrílicos , Concentração de Íons de Hidrogênio , Cinética , Modelos Químicos , Estrutura Molecular , Soluções , Temperatura
19.
Medicine (Baltimore) ; 95(19): e3390, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27175638

RESUMO

Tularemia is a zoonotic infection seen primarily in the Northern Hemisphere. It is caused by the bacteria Francisella tularensis. Although the ulceroglandular form of the disease is the more common manifestation of infection, F tularensis is known to cause pneumonia. F tularensis has two predominant subspecies, namely subsp. tularensis (type A) and subsp. holarctica (type B). Type B tularemia is considered to be much less virulent than type A and barely caused lethal disease and pneumonia.We reported a case with a 68-year-old man immune-compromised patient diagnosed with bacteremic pneumonia engendered by type B tularemia with initial presentation of high fever, pneumonia with pleural effusion; the diagnosis was performed using 16S rRNA gene sequence analysis. The patient's fever, pneumonia, and pleural effusion were resolved with appropriate antibiotics for tularemia. This case involving severe bacteremic pneumonia in an immune-compromised patient is rare.This case suggests that low virulence F tularensis should be included in the differential diagnoses of bacteremic pneumonia for endemic tularemia.


Assuntos
Bacteriemia/microbiologia , Febre/microbiologia , Francisella tularensis/patogenicidade , Pneumonia Bacteriana/microbiologia , Tularemia/complicações , Idoso , Humanos , Masculino , Tularemia/microbiologia , Virulência
20.
J Microbiol Immunol Infect ; 48(2): 175-82, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24064286

RESUMO

BACKGROUND: To identify the clinical characteristics and risk factors for mortality of patients with cefepime-resistant Pseudomonas aeruginosa (FRPa) bacteremia. METHODS: This retrospective study analyzed adult patients with FRPa bacteremia hospitalized between January 2006 and December 2011. RESULTS: Seventy eight patients (46 male, 32 female; mean age: 72.2 ± 14.1 years) were included. Of them, 46 (59.0%) had ventilator use and 45 (57.7%) had intensive care unit stay. All the bacteremia episodes were health-care associated or hospital acquired, and 55.1% of FRPa blood isolates were multidrug resistant. The sources of bacteremia were identified in 42 patients (53.8%), with pneumonia being the most common one (28/42; 66.7%). The mean interval between admission and the sample date of the first FRPa-positive blood culture was 45.8 ± 52.6 days. The mean Pittsburgh bacteremia score was 5.0 ± 3.4. The 15-day and 30-day mortality rates were 50.0% and 65.4%, respectively. Patients (41; 52.6%) on appropriate antibiotic therapy within 72 hours of the first FRPa-positive blood culture had a higher 30-day survival rate than those without (48.8% vs. 18.9%, p = 0.011 by log-rank test). Multivariate analyses revealed that a higher Pittsburgh bacteremia score was an independent risk factor for either 15-day (p = 0.002) or 30-day mortality (p = 0.010), and appropriate antibiotic therapy within 72 hours was an independent protecting factor for either 15-day (p = 0.049) or 30-day mortality (p = 0.017). CONCLUSION: FRPa bacteremia had a high mortality rate. The disease severity and appropriate antimicrobial therapy within 72 hours of positive blood culture were related to the patients' outcome.


Assuntos
Antibacterianos/farmacologia , Bacteriemia/mortalidade , Cefalosporinas/farmacologia , Infecções por Pseudomonas/mortalidade , Pseudomonas aeruginosa/efeitos dos fármacos , Resistência beta-Lactâmica , Adulto , Idoso , Idoso de 80 Anos ou mais , Bacteriemia/microbiologia , Bacteriemia/patologia , Cefepima , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/patologia , Pseudomonas aeruginosa/isolamento & purificação , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Análise de Sobrevida
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA