Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Methylene Blue”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1999

Potentiometric sensor for methylene blue based on methylene blue-silicotungstate ion association and its pharmaceutical applications.

A methylene blue (MB) poly(vinyl chloride) membrane sensor based on MB-silicotungstate (SLT) ion association as electroactive material was described. The linear response covered the range 1 x 10(-3)-1 x 10(-6) mol x dm(-3) MB solution, with a slope 52.0+/-0.8 mV decade(-1) (pH range 3.0-10.0). The detection limit was 7.65 x 10(-7) mol x dm(-3). The electrode showed stability, good reproducibility and fast response. Interferences from common inorganic cations, some organic base were negligible. These characteristics of the electrode enabled it to be used successfully for the determination of MB in injection. There was a good agreement for the results of MB content in injection between potentiometric method and USP standard procedure.

Calibration↗
PubMed2000

Microsporidia and Candida spores: their discrimination by Calcofluor, trichrome-blue and methylene-blue combination staining.

Faeces of immunocompromised patients are often contaminated with the chitin-containing spores of microsporidia and Candida, which exclude the use of the chitin-specific fluorescent brightener Calcofluor white M2R for the identification of microsporidian spores. We developed a combination staining of Calcofluor white M2R with modified trichrome-blue staining and subsequent methylene-blue incubation which permits discrimination between these two types of spores. As a basis for diagnosis, a difference in the fluorescence pattern (365-440 nm) is combined with a difference in the light microscopic staining pattern. Under fluorescence conditions microsporidia spores have a spotted, brilliant white Calcofluor fluorescence and can easily be identified, while Candida spores show a reddish purple colour. Under the light microscope microsporidian spores show a light red colour with nonstained vacuole spots or strips in contrast to the yeast spores with their red-brown colour. This combination technique offers a highly specific means for the diagnosis of microsporidia spores in faeces.

Animals↗
PubMed2002

Hematological effects in F344 rats and B6C3F1 mice during the 13-week gavage toxicity study of methylene blue trihydrate.

Methylene blue trihydrate is used widely as a dye and therapeutic agent. Methylene blue was administered by gavage to 30 animals/sex/dose group in a 0.5% aqueous methylcellulose suspension at doses of 0, 25, 50, 100, and 200 mg/kg. Blood samples from 10 animals/sex/dose group were collected at the end of study weeks 1, 6, and 13. Methylene blue treatment resulted in methemoglobin formation and oxidative damage to red blood cells, leading to a regenerative anemia and a variety of tissue and biochemical changes secondary to erythrocyte injury. An early change was a dose-related increase in methemoglobin, where the response of rats and mice was similar in magnitude. Mice appeared to be more sensitive than rats to the formation of Heinz bodies and the development of anemia that was characterized by a decrease in hemoglobin, hematocrit, and erythrocyte count. Splenomegaly was apparent in all treated mice and in the 100 mg/kg (males only) and 200 mg/kg rats at necropsy. There was a dose-related increase in absolute and relative spleen weight for both species. Microscopic examination revealed increased splenic hematopoiesis in all mice treatment groups and in rats at the 50 mg/kg dose level and above. Splenic congestion and bone marrow hyperplasia were also observed in these rat-dose groups. Mice at the higher doses showed hematopoiesis in the liver and accumulation of hemosiderin in Kupffer cells. These gross and microscopic findings are consistent with the development of hemolytic anemia. A dose-related increase in the reticulocyte count during study weeks 6 and 13 suggested a compensatory response to anemia.

Anemia↗
PubMed1996

Relaxation response to the rat stomach fundus to methylene blue.

When methylene blue (10(-4) M) was applied to the rat stomach fundus precontracted with 10(-6) M serotonin in the presence of 10(-6)M atropine and 10(-6) M guanethidine, slowly developing relaxation was induced. Methylene blue (10(-4) M) increased cyclic AMP but not cyclic GMP levels in the stomach fundus. These results suggest that methylene blue may relax the rat stomach fundus through cyclic AMP formation.

Animals↗
PubMed2000

Toluidine blue O and methylene blue as endothelial redox probes in the intact lung.

There is increasing evidence that the redox activities of the pulmonary endothelial surface may have important implications for the function of both lungs and blood. Because of the inherent complexity of intact organs, it can be difficult to study these activities in situ. Given the availability of appropriate indicator probes, the multiple-indicator dilution (MID) method is one approach for dealing with some aspects of this complexity. Therefore, the objectives of the present study were to 1) evaluate the potential utility of two thiazine redox indicators, methylene blue (MB) and toluidine blue O (TBO), as MID electron acceptor probes for in situ pulmonary endothelium and 2) develop a mathematical model of the pulmonary disposition of these indicators as a tool for quantifying their reduction on passage through the lungs. Experiments were carried out using isolated rabbit lungs perfused with physiological salt solution with or without plasma albumin over a range of flow rates. A large fraction of the injected TBO disappeared from the perfusate on passage through the lungs. The reduction of its oxidized, strongly polar, relatively hydrophilic blue form to its colorless, highly lipophilic reduced form was revealed by the presence of the reduced form in the venous effluent when plasma albumin was included in the perfusate. MB was also lost from the perfusate, but the fraction was considerably smaller than for TBO. A distributed-in-space-and-time model was developed to estimate the reduction rate parameter, which was approximately 29 and 1.0 ml/s for TBO and MB, respectively, and almost flow rate independent for both indicators. The results suggest the utility particularly of TBO as an electron acceptor probe for MID studies of in situ pulmonary endothelium and of the model for quantitative evaluation of the data.

Animals↗
PubMedDate not supplied

[The cytobacteriological coloring substance BF (methylene blue and basic fuchsin)].

The Authors have set up a cytobacteriological colouring matter for the reading of the figured elements of liquor, urine, exudats, and trasudats. The colouring solution is steady, it colours and fixes at the same time and is composed by blue methylene and basic fuchsine. There is abready a combination of both colouring matters in WAYSON'S formula for the bipolar colouring matter of the Pasteurella pestis and in PICK'S and Jacobson's formula to point out the intercellular neisserie.

Humans↗
PubMed1975

Photodynamic inactivation of herpesvirus hominins by methylene blue (38524).

Methylene blue, in a concentraion of 10-5M was virostatic in the presence of light but not in the dark for 31 of 37 strains of fresh isolates of herpesvirus hominis. Resistance to the dye developed during treatment. This photodynamic pattern was almost identical to that of neutral red which produced an identical effect. This was not ture for proflavine which was active in the dark in many instances. Cross insensitivity between proflavine and methylene blue was not observed.

Coloring Agents↗
PubMed1996

Pulmonary edema following intrauterine methylene blue injection.

Methylene blue is a commonly used dye in diagnostic procedures such as fistula detection, delineation of body tissues during surgery and for checking the patency of fallopian tubes. Many such dyes interfere with accurate measurement of oxygen saturation by a pulse oximeter. We report here a case in which methylene blue hot only interfered with pulse oximetery but also caused pulmonary edema in an ASA grade 1 patient.

Absorption↗
PubMed1982

Intraoperative identification of parathyroid glands: appraisal of methylene blue staining.

Methylene blue administered intravenously in a dose of 5 mg/kg of body weight was employed as an aid to the intraoperative identification of parathyroid glands in 90 patients undergoing surgery for hyperparathyroidism. Staining occurred in 95 percent of adenomas and 86 percent of hyperplastic glands. Normal and suppressed glands stained in 71 and 70 percent of cases, respectively. There were no adverse side effects from the technique. We conclude that preoperative intravenous infusion of methylene blue is a valuable technique that facilitates identification of parathyroid tissue at operation.

Humans↗
PubMed1998

The measurement of bioreductive capacity of tumor cells using methylene blue.

PURPOSE: Methylene blue (MB) can be used as an intracellular electron acceptor. The purpose of this study was to demonstrate the usefulness of MB for the determination of total bioreductive capacity of cell suspensions. METHODS AND MATERIALS: We measured oxygen consumption by Clark electrode and pentose cycle activity by release of 14CO2 from 1-14C-glucose. RESULTS: Methylene blue catalyzes the reaction of intracellular reductants NADPH, NADH, and reduced glutathione (GSH) with oxygen, causing the production of hydrogen peroxide. The reaction rate correlates with the negative charge of molecule (NADPH(-4) > NADH(-2) > GSH(-1)), suggesting that reaction with positively charged oxidized MB is the limiting step of the reaction. In a cellular system MB causes the electron flow from cellular endogenous substrates to oxygen. It is activated by the disruption of the NADP+/NADPH ratio due to several processes. These are direct oxidation of NADPH and GSH, the GSH peroxidase catalyzed reaction of GSH with H2O2, followed by NADPH oxidation by oxidized glutathione (GSSG). This results in increased cellular oxygen consumption and stimulation of the oxidative limb of pentose cycle (PC) in the presence of MB. The cellular effect of MB differs from other electron accepting drugs. Diamide and tert-butylhydroperoxide act as direct oxidants, while MB is an electron carrier to oxygen. Accordingly, MB shows the highest effect on PC activation and oxygen consumption. CONCLUSIONS: Our results indicate that MB may be used for the determination of the total bioreductive capacity of the cells, measured by oxygen consumption and PC activation.

Carbon Dioxide↗
PubMed2003

Urinary discoloration after rectal instillation of methylene blue dye.

Methylene blue is a vital dye that is used in the treatment of methaemoglobinaemia. It is also used to delineate tissues to facilitate identification during surgery. Discoloration of the urine is known after oral and intravenous administration of the dye. We have used it routinely to detect the presence of defects after colorectal anastomosis. However, there have not been any previous reports of urinary discoloration after brief rectal instillation of the dye. We report a case of self-limiting urinary discoloration after anterior resection with colorectal anastomosis.

Adenocarcinoma↗
PubMed1989

[Antitumor effect of methylene blue in vivo].

Methylene blue can inhibit the growth of Ehrlich ascitic tumor, L1210 leukemia and P388 leukemia in mice. The average life span of the treated animals was obviously longer than that of the controls. Methylene blue was superior to 5-Fu in the treatment of L1210 leukemia of mice and two thirds of the mice with P388 leukemia were healthy and survived for more than 60 days after administrated different doses of methylene blue. When adriamycin was given simultaneously with methylene blue to mice, the acute toxic effect of adriamycin was decreased and the survival time prolonged. Methylene blue is a highly ionized and a rapidly eliminated drug which can combine well with tissues at higher concentration maintained for several hours and can easily pass through the blood-brain barrier.

Animals↗
PubMed1976

Photooxidation of methionine with immobilized methylene blue as photooxidizer.

Methylene blue immobilized on porous glass beads was used to catalyze the photooxidation of methionine alone and the methionine residues of lysozyme. A solution of 2 mM methionine in 50% acetic acid was oxidized to methionine sulfoxide in the presence of immobilized methylene blue after 6 h of photooxidation at 37 degrees C. Selective photooxidation of the methionyl residues in lysozyme was achieved after 26 h of reaction in 84% acetic acid at 4 degrees C. The specific activity of lysozyme exposed to light in the presence of methylene blue decreased by 94%, while that of a lysozyme solution in the presence of methylene blue not exposed to light decreased by 21%. The lysozyme solution exposed to light but not containing the methylene blue beads lost 33% of its specific activity after the same period of photooxidation. It was shown that the decrease in enzyme activity was not caused by adsorption of the enzyme onto the beads.

Hydrogen-Ion Concentration↗