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 19 recordsLinked to original sources
PubMed1985

The morphology of redox-dye-treated HbH-containing red cells: differences between cells treated with brilliant cresyl blue, methylene blue and new methylene blue.

The ultrastructure of redox-dye-treated HbH-containing red cells has been shown to be dependent on the nature of the redox dye used. Brilliant cresyl blue causes the formation of a large number of small inclusions which are invariably attached to the inner surface of the red cell membrane. Methylene blue and new methylene blue cause the formation of a much smaller number of larger inclusions only some of which appear to be membrane-bound. These ultrastructural differences are reflected in marked differences in the light microscope appearances of the supravitally-stained cells.

Adult↗
PubMed1993

Novel actions of methylene blue.

Methylene blue has been frequently used as an inhibitor of soluble guanylyl cyclase. We found that endothelium-dependent relaxations of isolated blood vessels were considerably more sensitive to inhibition by methylene blue than relaxation induced by direct activators of soluble guanylyl cyclase. Similar data were obtained in the presence of superoxide dismutase, indicating that the diverse potencies of methylene blue were not due to superoxide-induced inactivation of nitric oxide (NO). Subsequent experiments revealed that methylene blue is an inhibitor of purified NO synthase. Conversion of L-arginine to L-citrulline was inhibited by the dye in a concentration-dependent fashion with half-maximal effects observed at 5.3 microM and 9.2 microM in the absence and presence of superoxide dismutase, respectively. Purified soluble guanylyl cyclase, however, was far less sensitive to methylene blue. When the enzyme was maximally stimulated with S-nitroso-glutathione, cyclic guanosine monophosphate, (cGMP) formation was reduced by 50% at approximately 60 microM methylene blue; 1 mM produced maximal inhibitions of about 70%. Our data indicate that methylene blue is only a poor inhibitor of soluble guanylyl cyclase. The dye seems to act primarily via inhibition of NO synthase, with enzyme-bound heme being a possible target in its inhibitory action.

Amino Acid Oxidoreductases↗
PubMed1993

Inhibition of nitric oxide synthesis by methylene blue.

Methylene blue appears to inhibit nitric oxide-stimulated soluble guanylyl cyclase and has been widely used for inhibition of cGMP-mediated processes. We report here that endothelium-dependent relaxation of isolated blood vessels and NO synthase-dependent cGMP formation in cultured endothelial cells were both markedly more sensitive to inhibition by methylene blue than effects induced by direct activation of soluble guanylyl cyclase. These discrepancies were also observed when superoxide dismutase (SOD) was present to protect NO from inactivation by superoxide anion. Subsequent experiments showed that formation of L-citrulline by purified NO synthase was completely inhibited by 30 microM methylene blue (IC50 = 5.3 and 9.2 microM in the absence and presence of SOD, respectively), whereas guanylyl cyclase stimulated by S-nitrosoglutathione was far less sensitive to the drug (50% inhibition at approximately 60 microM, and maximal inhibition of 72% at 1 mM methylene blue). Experimental evidence indicated that oxidation of NADPH, tetrahydrobiopterin or reduced flavins does not account for the inhibitory effects of methylene blue. Our data suggest that methylene blue acts as a direct inhibitor of NO synthase and is a much less specific and potent inhibitor of guanylyl cyclase than hitherto assumed.

Amino Acid Oxidoreductases↗
PubMed1978

Preservation of erythrocytes using metabolic regulators and mutrients. V. Inosine and methylene blue.

Methylene blue and inosine have been shown to stimulate glycolytic metabolism in the erythrocytes, increasing the concentration of 2.3-diphosphoglycerate (2,3-DPG), which is necessary for hemoglobin function, by regulating oxidative metabolism and providing a five-carbon nutrient for glycolysis, respectively. However, a recent study suggested that the methylene blue effect was dependent on the presence of inosine. This study was designed to establish, if possible, the existence of a methylene blue effect and to confirm the usefulness of inosine. The optimal concentration of inosine for increasing 2,3-DPG synthesis in a CPD-adenine preservative is confirmed to be 10--15 mM. Concentrations of 2,3-DPG were maintained in the erythrocytes at normal or higher levels for 21 days of storage with 10 or 15 mM inosine, whether the methylene blue was present or not. However, when methylene blue was present, 2,3-DPG concentrations were significantly better maintained.

Adenine↗
PubMed1986

In vitro oxidation of uric acid in serum by methylene blue.

Methylene blue oxidizes uric acid to allantoin in vitro, analogous to the reaction between uric acid and phosphotungstate, although the rate is considerably slower. The reaction requires oxygen and produces hydrogen peroxide. As little as 10 micromol of methylene blue per liter in a serum sample will produce a measurable difference in the apparent uric acid concentration within 4 h at room temperature. Methylene blue may be administered for various medical reasons. If uric acid is to be measured in such sera, the procedure should be performed within 30 min, whatever method of analysis is used.

Aerobiosis↗
PubMedDate not supplied

Methylene blue.

Methylene blue finds its major utilization in toxicology in the treatment of methemoglobinemia at a dose of 1 to 2 mg/kg intravenously. By interacting with methemoglobin and the erythrocyte's enzyme systems to reduce back to hemoglobin, methylene blue is a generally safe drug with dose-related hemolytic effects. People with G-6-PD deficiency, along with patients exposed to aniline dyes and dapsone, may present with special risks in the treatment of methemoglobinemia.

Dose-Response Relationship, Drug↗
PubMed1980

Inhibition of thiamine transport in baker's yeast by methylene blue.

Methylene blue was found to inhibit thiamine transport competitively (Ki = 0.63 microM) in baker's yeast. The dye was also effective in abolishing the growth inhibition of Saccharomyces cerevisiae by pyrithiamine which is known to be taken up by a common transport system for thiamine in yeast cells. A possible mechanism for the inhibition by methylene blue of the thiamine transport system in baker's yeast is discussed.

Biological Transport↗
PubMed2005

A comparison of the adverse reactions associated with isosulfan blue versus methylene blue dye in sentinel lymph node biopsy for breast cancer.

BACKGROUND: Sentinel lymph node biopsy (SLNB) is an established means of staging the axilla in patients with breast cancer. Recently, methylene blue dye has been shown to be an efficacious and cost-effective alternative to isosulfan blue. With the increasing popularity of SLNB, the potential complications of isosulfan blue use must be appreciated. METHODS: A literature search for English language articles available on MEDLINE from 1985 to November 2002 using the search terms allergy, allergic reaction, anaphylactic reactions, anaphylaxis, blue dye, breast cancer, isosulfan blue, methylene blue, and sentinel lymph node biopsy identified 24 reports. CONCLUSIONS: The use of isosulfan blue due for SLNB is associated with a significant number of allergic reactions, some of which are life-threatening. Because methylene blue dye has been shown to be equally effective and does not pose a serious risk of serious allergic reactions, it offers an improved technique above isosulfan blue dye for SLNB.

Axilla↗
PubMed1987

An autoantibody with potent antithrombin activity whose action could be inhibited by toluidine blue or methylene blue.

A 41-year-old man with posthepatic liver cirrhosis and bleeding tendency was found to have a circulating anticoagulant with potent antithrombin activity. The thrombin time of the patient's purified fibrinogen was normal. This anticoagulant was residing in the patient's IgG fraction, and his IgG fraction could prolong the thrombin time of purified fibrinogen, suggesting that this circulating anticoagulant was an antibody. No heparin was detected in the patient's plasma. However, the antithrombin activity of this anticoagulant could be neutralized by toluidine blue or methylene blue ex vivo.

Adult↗
PubMed1987

The effect of toluidine blue and methylene blue in immunochemical reactions in vitro.

Our observation that the effect of a patient's autoantibody with a potent antithrombin activity could be inhibited by toluidine blue and methylene blue led us to investigate the effect of these dyes in several immunochemical reactions in vitro. Both dyes reduced the titer or prevented the detection of IgG-specific single- and double-stranded DNA-binding antibodies and rheumatoid factors but did not reduce the titer of antinuclear factor and had no effect on detection of microsomal and thyroglobulin antibodies. These dyes did not aggregate or precipitate the immunoglobulins and their inhibitory effect in serum could be removed by dialysis of serum. The possible mechanism of action of these dyes in immunochemical reactions is discussed.

Antibodies, Antinuclear↗
PubMed2003

The effect of methylene blue photoinactivation and methylene blue removal on the quality of fresh-frozen plasma.

BACKGROUND: T: he effects of using fresh or frozen-thawed plasma, WBC reduction of plasma before freezing, and the use of two different methylene blue (MB) removal filters on the quality of MB-treated plasma were compared. STUDY DESIGN AND METHODS: In a paired study (n = 11/arm) plasma was frozen within 8 hours of collection, thawed, MB photoinactivated, and then filtered using one of two MB removal filters. Fresh plasma (n = 16) and plasma WBC reduced before freezing (n = 19) were MB inactivated. RESULTS: Freeze-thawing resulted in loss of activity of FXII and VWF of 0.06 and 0.04 units per mL, respectively, but no significant loss of activity of factors II through XI or fibrinogen. Further loss of activity occurred after MB treatment: FII (0.07 IU/mL), FV (0.11 U/mL), FVII (0.08 IU/mL), FVIII (0.28 IU/mL), F IX (0.12 IU/mL), FX (0.16 IU/mL), FXI (0.28 U/mL), FXII (0.15 U/mL), VWF antigen (0.05 IU/mL), VWF activity (0.06 U/mL), and fibrinogen (0.79 g/L). Losses due to this step were significantly (5-10%) lower in fresh plasma compared to frozen-thawed plasma. Neither MB removal filter resulted in significant loss of activity of any factor studied. CONCLUSION: MB removal, by either of the available filters, has little impact on the coagulation factor content of plasma, but freezing of plasma before MB treatment results in a small additional loss.

Blood Coagulation↗
PubMed1997

Comparison of methylene blue and methylene violet for photoinactivation of intracellular and extracellular virus in red cell suspensions.

Previous studies with methylene blue (MB) in red cell suspensions have demonstrated that extracellular, but not intracellular, virus can be readily photoinactivated. To test if the resistance of intracellular virus to inactivation is related to the permanent positive charge of the phenothiazine, a series of uncharged phenothiazine dyes, methylene violet (MV), monodemethylated MV and didemethylated MV, were studied. Values of the sensitivity of intracellular relative to extracellular vesicular stomatitis virus (VSV) inactivation for the three dyes (D10 extracellular/D10 intracellular) in buffer were 1.0, 0.60 and 0.33, respectively. In contrast, intracellular virus was resistant to inactivation with MB, with a D10 extracellular/D10 intracellular of 0.05 in buffer. Because virucidal activity of MV was inhibited by the presence of plasma, the red cells (30% hematocrit) were repeatedly washed prior to photoinactivation and storage. Under conditions where MB and MV inactivated approximately 5 log10 of extracellular VSV, intracellular VSV was inactivated by more than 4 log10 with MV compared to 0.88 log10 with MB. These phototreatment conditions did not significantly affect red cell morphology, extracellular pH, ATP or 2,3-diphosphoglycerol levels during 42 days of 1-6 degrees C storage. There was enhanced potassium efflux and hemolysis over values obtained from untreated control; the extent of change from controls was comparable for each phototreatment. These results indicate that the uncharged phenothiazine dye, MV, can inactivate both intracellular and extracellular virus yet exhibit similar in vitro red cell storage properties as MB phototreatment.

Blood-Borne Pathogens↗
PubMed2005

The influence of methylene blue light treatment and methylene blue removal filter on fibrinogen activity states and fibrin polymerisation indices.

BACKGROUND/OBJECTIVE: Methylene blue light treatment (MBLT) is efficient in inactivating viruses in plasma. However, it may cause alterations in clotting factors, especially fibrinogen (Fg). The true mechanism of such a selective alteration is poorly understood, The effects of MBLT and MB removal filters (MBRF) on Fg concentration, functional activity and fibrin polymerisation were studied. DESIGN: Apheresis plasma collected by Haemonetic MCS Plus (n=10) was split into two equal aliquots. Both were leukofiltered and virally inactivated in a standardized fashion, using Theraflex MB-Plasma Photodynamic viral inactivation Macopharma method. One of the pair was subsequently processed, using Blueflex MBRF to remove residual MB and its by-products. Control plasma samples were obtained after filtration but before MBLT. Samples were also obtained after MBLT and MBRF. All samples were analyzed for the Fg activity, Fg antigen, thrombin clotting time (TT), and alterations fibrin polymerisation indices. RESULTS: After MBLT, mean Fg concentration increased slightly (2%) whereas functional activity decreased by 31%, as compared to control samples. Mean TT prolonged by 6s after MBLT, with no further changes after MBRF. A similar trend was observed using RT. Both thrombin and reptilase triggered fibrin polymerisation were delayed and the polymerisation curves slopes were decreased slightly, with concomitant changes in fibrin opacity in samples from MBLT and MBRF as compared to control. Comparison is made for the first time with a similar changes observed in dysfibrinogenemia. CONCLUSION: MBLT resulted in about 30% decrease in Fg activity but a slight modification in fibrin polymerisation indices, with no additional alteration subsequent to MBRF. These in vitro changes are similar to those seen in plasma from patients with dysfibrinogenemia, which are usually without clinical significance.

Blood Preservation↗
PubMed1989

Methaemoglobin production and reduction by methylene blue and the interaction of methylene blue with sodium nitrite in vivo.

Methylene blue, at high concentrations, interferes with the estimation of methaemoglobin using the IL 282 CO-oximeter: the dye does not interfere with the method of Evelyn & Malloy for determination of methaemoglobin. In beagle bitches methylene blue causes both methaemoglobinogenesis and methaemoglobin reduction, the effect of the former being to delay the decline of methaemoglobin levels, when methylene blue is used to reverse the methaemoglobinaemia produced by sodium nitrite.

Animals↗