Methylene Blue

A thorough understanding of the mechanisms of R-, C-and G-banding will come only from studies of the binding of Giemsa dyes to isolated and characterized preparations of heterochromatin and euchromatin. Since such studies require an exact knowledge of the optical characteristics of Giemsa, the spectral adsorption curves and extinction coefficients of Giemsa and its component dyes at various concentrations in the presence and absence of DNA were determined. — Although Giemsa is a complex mixture of thiazin dyes plus eosin; methylene blue, and azure A, B or C alone gave good banding. Thionin, with no methyl groups, gave poor or no banding. Eosin was not a necessary component for banding. — The most striking characteristic of the thiazin dyes is that they are strongly metachromatic, i.e., their adsorption spectra and extinction coefficients change as the concentration of the dye increases or as they bind to positively charged compounds (chromotropes). These changes, especially for methylene blue, are described in detail and allow a distinction between concentration dependent binding to DNA by intercalation and binding by side stacking.

In order to develop efficient photocatalytic TiO2 films and membranes for application in water and wastewater treatment and reuse systems, there is a great need to tailor-design the structural properties of TiO2 material and enhance its photocatalytic activity. Through a ...

We present a study on whether and to what extent subcellular localization may compete favorably with photosensitization efficiency with respect to the overall efficiency of photoinduced cell death. We have compared the efficiency with which two cationic photosensitizers, namely methylene blue (MB) and crystal violet (CV), induce the photoinduced death of human cervical adenocarcinoma (HeLa) cells. Whereas MB is well known to generate singlet oxygen and related triplet excited species with high quantum yields in a variety of biological and chemical environments (i.e., acting as a typical type II photosensitizer), the highly mitochondria-specific CV produces triplet species and singlet oxygen with low yields, acting mostly via the classical type I mechanism (e.g., via free radicals). The findings described here indicate that the presumably more phototoxic type II photosensitizer (MB) does not lead to higher degrees of cell death compared to the type I (CV) photosensitizer. In fact, CV kills cells with the same efficiency as MB, generating at least 10 times fewer photoinduced reactive species. Therefore, subcellular localization is indeed more important than photochemical reactivity in terms of overall cell killing, with mitochondrial localization representing a highly desirable property for the development of more specific/efficient photosensitizers for photodynamic therapy applications.

Vasoplegic syndrome is a form of vasodilatory shock that occurs frequently in patients who undergo cardiac surgery requiring cardiopulmonary bypass (CBP). Treatment often demands high doses of vasopressors over sustained periods for hypotension that can be refractory to standard vasoactive medications. Furthermore, the development of vasoplegia greatly contributes to morbidity and mortality following cardiac surgery. Methylene blue (MB) has become a popular therapy for cardiac vasoplegia despite a paucity of prospective data to direct its use. Therefore, the aim of this study was to review available data regarding mechanisms, dosing strategies, and side effects of MB, with a focus on its applications for vasoplegia in cardiac surgery.

Renal transplantation is associated with frequent gastrointestinal complications. Intestinal metaplasia is a feature of atrophic gastritis whereas the diagnosis of Barrett's esophagus is based on histological demonstration of specialized metaplasia. Both conditions are associated with increased risk of adenocarcinoma. The aim of the present study was to assess whether magnification endoscopy improves the diagnostic accuracy of intestinal metaplasia in stomach and in esophagus. In this non-randomized, feasibility study thirty one (12 women and 19 men) renal transplant recipients, with a mean age of 44.0 years were evaluated for the presence of intestinal metaplasia. Standard esophagogastroscopy with methylene blue staining was followed by magnification endoscopy. The presence of gastritis and intestinal metaplasia was classified according to modified updated Sydney classification. Of 31 patients, 16 patients had endoscopic and histopathological evidence of gastric intestinal meta...

The cellulose acetate-polystyrene or CA-PS composite membrane from pineapple peel waste for methylene blue removal has been conducted. The steps were nata de pina preparation, cellulose acetylation process, preparation, and characterization of CA-PS composite membrane. The CA-PS composite membrane was characterized using Fourier Transform Infrared (FT-IR), Scanning Electron Microscopy (SEM), tensile and strain examination, respectively. The as-synthesized CA-PS composite membrane has the characteristic of rejection ability was about 29.96% with the pore size, membrane modulus, stress and strain were 1.9 μm, 12.48 MPa, 31.91 MPa, and 2.55, respectively. In this research, CA-PS composite membrane from pineapple peel waste was successfully removed the methylene blue dye even needs improvement to enhance its capability in rejection efficiency as same as membrane characteristics.

The purpose of this study was to compare the sealing ability of the temporary restorative materials Cavit-G, Ketac Molar Easymix, and IRM with a new light-curing temporary material, Clip, using a methylene blue dye penetration test. Endodontic access preparations were prepared in 48 intact extracted human premolars. The teeth were divided into 6 groups, including positive and negative control groups. After access preparation, cotton pellets were placed in the pulp chamber so that the space remaining for the restoration was 4 mm. After thermal cycling for 500 cycles (5 degrees C-55 degrees C), the teeth were immersed in 2% methylene blue solution at neutral (pH = 7.0) in an incubator for leakage assessment. The teeth were sectioned, and the greatest depth of dye penetration was recorded. Marginal leakage was evaluated with a stereomicroscope. Positive control sections exhibited complete dye penetration, and negative controls had none. In the experimental groups, the differences in th...

The aim of this study was to evaluate the influence of caries-detecting dyes on the microleakage of adhesive materials. Sixty cubic class V cavities were prepared on buccal and lingual surfaces of 30 human third molars. Coronal margins were located in enamel and gingival margins in cementum. The teeth were randomly divided into six groups of ten restorations each. Cavities were restored with an adhesive system (Single Bond, 3M ESPE, St. Paul, Minn., USA), a compomer (F2000, 3M ESPE), or a composite resin (Z100, 3M ESPE) according to the manufacturer's directions. Acid red dye (Seek, Ultradent, South Jordan, Ut., USA) and basic fuchsin dye (Vide Cárie, Inodon, Porto Alegre, Brazil) were tested. Control groups were prepared without the use of dyes. After 7 days of storage in distilled water, the restorations were polished and the teeth were subjected to thermal cycling followed by immersion in 2% methylene blue. The teeth were sectioned, and microleakage scores were evaluated under magnification (40×). Data were submitted to statistical analysis using the nonparametric Kruskal-Wallis test. A statistically significant difference (PF2000) but not in enamel. Control and experimental groups using dyes showed similar results. It was concluded that dyes for caries detection did not increase microleakage of the adhesive materials tested.

Activated carbon prepared from non-wood forest product waste (rattan sawdust) has been utilized as the adsorbent for the removal of meth-ylene blue dye from an aqueous solution. The experimental data were analyzed by the Langmuir and Freundlich models of adsorption. Equilibrium data fitted well with the Langmuir model with maximum monolayer adsorption capacity of 294.14 mg/g. The dimensionless factor, R L revealed the favorable nature of the isotherm of the dyeeactivated carbon system. The rates of adsorption were found to conform to the pseudo-second-order kinetics with good correlation. The kinetic parameters of this best-fit model were calculated and the results are discussed.