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Diogo dos Santos Miron

Bio: Diogo dos Santos Miron is an academic researcher from University of Caxias do Sul. The author has contributed to research in topics: Solubility & HEPA. The author has an hindex of 4, co-authored 5 publications receiving 48 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the authors evaluated the solubility of the HPMC and PVA blend compared to isolated polymers in solutions with a pH of biological fluids (6 and 1.2).
Abstract: Received: September 22, 2010; Revised: April 28, 2011Polymers are often used to coat tablets for controlled drug release. The purpose of this study is to evaluate the solubility of the HPMC and PVA blend compared to isolated polymers in solutions with a pH of biological fluids (6 and 1.2) and the dissolution of capsules obtained using theophylline granules produced with the HPMC/PVA 25/75 blend as a matrix and as coating. HPMC is completely solubilized in the medium that simulates the pH of the stomach and intestine, and PVA is the polymer that allows controlling the solubility of the blend in the medium, with a differents pH. The dissolution time was monitored by UV absorbance with maximum theophylline at 269 nm. The theophylline was released immediately in the granules, and in the capsules 78.4% after 30 minutes and 97.4%, after 120 minutes. Thus, PVA can potentially control the drug solubilization, contributing to obtaining modified release systems.

23 citations

Journal ArticleDOI
01 Sep 2013-Mycoses
TL;DR: Fungal contamination of the indoor air may influence the frequency of AI in ICU patients, and environmental factors have a direct influence on fungal spore concentration in the air in ICUs, as well as air filtration systems in air conditioners.
Abstract: Summary Invasive aspergillosis (IA) seems to be an emerging condition in intensive care units (ICUs). However, little attention has been given to the role of environmental factors that could increase the risk for IA in the ICU. The objective of this study was to determine the concentration of airborne fungi in three Brazilian ICUs, in an attempt to correlate fungal burden with the frequency of Aspergillus spp isolation from clinical samples of patients hospitalised in these units. During a 1-year period we quantitatively evaluated the presence of fungi in the air of three ICUs in Porto Alegre, Brazil. The quantity of fungi was correlated with environmental factors. Only one of the ICUs studied showed equal concentrations of Aspergillus conidia in the indoor air, in comparison with the outdoor environment. All cases of Aspergillus colonisation and IA cases observed during the study occurred in that particular ICU. Environmental factors have a direct influence on fungal spore concentration in the air in ICUs, as well as air filtration systems in air conditioners. Fungal contamination of the indoor air may influence the frequency of AI in ICU patients.

13 citations

Journal ArticleDOI
TL;DR: It is demonstrated that the incubation of plates at 35-40°C facilitates growth of Aspergillus section Fumigati, the most important pathogenic mold in humans.

8 citations

Journal ArticleDOI
TL;DR: Air samples were collected in two haematopoietic stem cell transplantation units, in which distinct air-control systems were in place, and rooms in both hospitals showed similar concentrations of potentially pathogenic fungi.
Abstract: Invasive fungal diseases have emerged as important causes of morbidity and mortality in haematological patients. In this study air samples were collected in two haematopoietic stem cell transplantation (HSCT) units, in which distinct air-control systems were in place. In hospital 1 no high-efficiency particulate air (HEPA) filter was available whereas in hospital 2 HSCT rooms were equipped with HEPA filters, with positive air pressure in relation to the corridor. A total of 117 samples from rooms, toilets and corridors were obtained during December 2009 to January 2011, using a six-stage Andersen sampler. In both hospitals, the concentration of potentially pathogenic fungi in the air was reduced in patients' rooms compared to corridors (P < 0·0001). Despite the presence of a HEPA filter in hospital 2, rooms in both hospitals showed similar concentrations of potentially pathogenic fungi (P = 0·714). These findings may be explained by the implementation of additional protective measures in hospital 1, emphasizing the importance of such measures in protected environments.

5 citations

Journal ArticleDOI
TL;DR: The method developed is effective to analyze tibolone in capsules, being able to be used in quality control laboratory routine, and the validation parameters evaluated were specificity, linearity, precision, accuracy, detection and quantification limits and robustness.
Abstract: Tibolone is a synthetic steroid used for prevention of bone loss and treatment of menopause symptoms. This article describes the development and validation of an analytical method to quantify tibolone in capsules using high performance liquid chromatography with UV detection. After chromatography conditions are established the validation parameters evaluated were specificity, linearity, precision, accuracy, detection and quantification limits and robustness. The method developed is effective to analyze tibolone in capsules, being able to be used in quality control laboratory routine.

2 citations


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Journal ArticleDOI
TL;DR: Echinocandins remain a major component of treatment of invasive candidiasis and new triazoles are the best alternative for prophylaxis and therapy of invasive aspergillosis, but an increase in intrinsically resistant fungi and emergence of secondary resistance as a result of drug-induced selection pressure are of major concern.
Abstract: Summary Critically ill patients and patients with haematological cancer are HIV-negative populations at high risk of invasive fungal infections. In intensive-care units, candidaemia and intra-abdominal candidiasis predominate, but aspergillosis has emerged as a lethal, under-recognised cause of pneumonia. In patients with haematological malignancies or who have undergone stem-cell transplantations, pulmonary disease due to aspergillus and other mould diseases predominate. In this Series paper, we provide an update on risk assessment, new diagnostic strategies, and therapeutic approaches. New concepts have emerged for use of risk prediction rules and an evidence base now exists for inclusion of biomarkers (eg, galactomannan, 1,3-β-D-glucan, and PCR assays for Aspergillus spp) into early diagnostic and therapeutic strategies. Imaging techniques remain helpful for early diagnosis of pulmonary mould diseases, with PET techniques offering potential improvements in diagnostic specificity and evaluation of clinical response. Echinocandins and triazoles have been validated extensively for prophylaxis, empirical therapy, and targeted therapy, but an increase in intrinsically resistant fungi and emergence of secondary resistance as a result of drug-induced selection pressure are of major concern. Echinocandins remain a major component of treatment of invasive candidiasis and new triazoles are the best alternative for prophylaxis and therapy of invasive aspergillosis.

119 citations

Journal ArticleDOI
TL;DR: The clinical studies described in this research agenda should provide a template and set priorities for the clinical investigations that need to be performed over the next decade and their expected outcomes with regard to Candida and Aspergillus infections in non-neutropenic patients in the ICU setting.
Abstract: To describe concisely the current standards of care, major recent advances, common beliefs that have been contradicted by recent trials, areas of uncertainty, and clinical studies that need to be performed over the next decade and their expected outcomes with regard to Candida and Aspergillus infections in non-neutropenic patients in the ICU setting. A systematic review of the medical literature taking account of national and international guidelines and expert opinion. Severe invasive fungal infections (IFIs) are becoming increasingly frequent in critically ill patients. Approximately 80% of IFIs are due to Candida spp. and 0.3–19% to Aspergillus spp. Recent observations emphasize the necessity of building a worldwide sentinel network to monitor the emergence of new fungal species and changes in susceptibility. Robust data on the attributable mortality are essential for the design of clinical studies with mortality endpoints. Although early antifungal therapy for Candida has been recommended in patients with risk factors, sepsis of unknown cause, and positive Candida serum biomarkers [β-1 → 3-d-glucan (BDG) and Candida albicans germ tube antibody (CAGTA)], its usefulness and influence on outcome need to be confirmed. Future studies may specifically address the optimal diagnostic and therapeutic strategies for patients with abdominal candidiasis. Better knowledge of the pharmacokinetics of antifungal molecules and tissue penetration is a key issue for intensivists. Regarding invasive aspergillosis, further investigation is needed to determine its incidence in the ICU, its relationship with influenza outbreaks, the clinical impact of rapid diagnosis, and the significance of combination treatment. Fundamental questions regarding IFI have to be addressed over the next decade. The clinical studies described in this research agenda should provide a template and set priorities for the clinical investigations that need to be performed.

117 citations

Journal ArticleDOI
TL;DR: Operating sophisticated mechanical ventilation systems in hospitals contributes to improved indoor air quality within hospitals, which assists in reducing the risk of airborne transmission of HAI.

101 citations

Journal ArticleDOI
TL;DR: In this article, deproteinized natural rubber latex (DNRL) was used to investigate the properties of films after it was blended with various adhesive polymers: hydroxypropylmethyl cellulose (HPMC), methyl cellulose, SCMC, poly(vinyl alcohol) (PVA), poloxamer 407, and sodium alginate.
Abstract: This work aimed first to prepare deproteinized natural rubber latex (DNRL) and investigate the properties of films after it was blended with various adhesive polymers: hydroxypropylmethyl cellulose (HPMC), methyl cellulose (MC), sodium carboxymethyl cellulose (SCMC), poly(vinyl alcohol) (PVA), poloxamer 407, and sodium alginate. The second aim was to identify the films that would be the best for medical and pharmaceutical applications. Dibutyl phthalate (DBP), diethyl phthalate, dibutyl sebacate, triethyl citrate, and glycerin (GLY) were used as plasticizers to improve the elasticity and adhesiveness of the novel materials. DNRL was prepared by proteolytic alcalase enzyme treatment, followed by centrifugation. The DNRL was virtually free of protein, produced no significant reaction in the rabbit skin irritation test, and formed a good elastic film, but it had low skin adhesive properties. Blending DNRL with several polymers produced better films with different elastic and adhesive properties. Moisture upt...

76 citations

Journal ArticleDOI
TL;DR: A high level of suspicion in critically ill patients presenting with Aspergillus-positive respiratory tract cultures or nonresolving pulmonary infection may lead to earlier IPA diagnosis, and Dosage individualization may decrease treatment discontinuation and improve clinical efficacy.
Abstract: PURPOSE OF REVIEW: Apparently immunocompetent critically ill patients represent an increasing population at risk for invasive pulmonary aspergillosis (IPA). The current review gives an update on the epidemiology, diagnosis, and management of IPA in the ICU. RECENT FINDINGS: Patients without apparent severe immunosuppression (e.g. chronic obstructive pulmonary disease, decompensated liver disease, etc.) represent the majority of ICU IPA cases. IPA diagnosis is problematic and the true incidence of IPA is difficult to be estimated because of the nonspecific clinical presentation. A user-friendly clinical diagnostic algorithm for IPA is valuable, particularly through a high negative predictive value. IPA carries a poor prognosis and has an important impact on hospital costs. Timely diagnosis and prompt administration of appropriate treatment may improve the outcomes. Intravenous voriconazole is the recommended primary IPA treatment, but liposomal amphotericin B also has clinical utility. Voriconazole presents bioavailability and toxicity issues, and drug level monitoring is advocated. Caspofungin or antifungal combinations are recommended as salvage therapy. SUMMARY: A high level of suspicion in critically ill patients presenting with Aspergillus-positive respiratory tract cultures or nonresolving pulmonary infection may lead to earlier IPA diagnosis. Dosage individualization may decrease treatment discontinuation and improve clinical efficacy.

65 citations