New Methylene Blue Research Articles

Study of adsorption of methylene blue and new methylene blue in liquid–solid interface by slab optical waveguide spectroscopy

A slab optical waveguide (SOWG) has been used for study of adsorption of both methylene blue (MB) and new methylene blue (NMB) in liquid–solid interface. Adsorption characteristics of MB and NMB on both bare SOWG and silanized SOWG by octadecyltrichlorosilane (ODS) were compared. Effect of pH on adsorption on MB and NMB was investigated. Binding rate constant analysis showed that both MB and NMB on bare SOWG demonstrates larger association constants than those on ODS-SOWG. Interactions of MB and NMB on bare SOWG and ODS-SOWG were analyzed by molecular mechanics calculation method. The binding energy change was in the following order: E NMB–bare > E MB–bare > E NMB–ODS > E MB–ODS.

Distribution of new methylene blue injected into the lumbosacral epidural space in cats

ObjectiveTo determine the effects of injection volume and vertebral anatomy on the spread of new methylene blue (NMB) injected into the lumbosacral epidural space in cats. Study designProspective experimental study. Sample populationSixteen cats. MethodsCats were randomly assigned to four groups and received from 0.1 to 0.4 mL kg−1 of 0.12% NMB in 0.9% saline. Injection was made into the lumbosacral epidural space using a dorsal approach with the cats in sternal recumbency. The extent of cranial migration of the dye as indicated by the staining of epidural fat and dura mater was measured. ResultsThe mean ± SD (range) number of stained vertebrae in the 0.3 and 0.4 mL kg−1 groups, were 11.5 ± 1.5 (T7–T11) and 12.4 ± 1.8 (T6–T10), respectively. This was significantly greater than the number in the 0.1 and 0.2 mL kg−1 groups, 4.3 ± 0.6 (L3–L4) and 6.0 ± 0.7 (L1–L2) vertebrae, respectively (p < 0.001). Linear regression analysis showed that the volume injected correlated significantly with the number of stained vertebrae (R2 = 0.83, p < 0.001). In the dorsal and lateral aspect of the spinal cord, NMB solution distributed between epidural fat and dura mater. Migration under the spinal cord occurred along the two longitudinal epidural veins. Conclusions and clinical relevanceThe larger the volume of solution injected into the lumbosacral epidural space in cats, the greater the spread.

Eliminating the effect of epidural fat during dorsolumbar epidural analgesia in cattle

ObjectiveTo compare the distribution of new methylene blue (NMB) solution injected into either the subperiosteal space or under the epidural fat at the first and second lumbar vertebral interspace in cattle. Study designProspective experimental study. Sample populationNine nonpregnant cows. MethodsNeedles were advanced towards the first interlumbar epidural space using a dorsal mid-line approach. Upon confirmation of successful penetration of the ligamentum flavum, group 1 received 5 mL of 0.12% NMB in 0.9% saline. In group 2, the needle was slowly advanced a further 7–10 mm to ensure injection under the epidural fat; the same dose was injected. The extent of cranial and caudal migration of dye, as indicated by staining of epidural fat and the dura mater was measured. ResultsIn group 1 (n = 4), NMB solution migrated only between the periosteum and the epidural fat. There was unilateral distribution in two cows. In contrast, there was no difference between left- and right-sided distribution in group 2 (n = 5), and the NMB solution migrated only between epidural fat and the dura mater. Although the dura mater was not penetrated in any animal of group 2, the dorsal roots were slightly stained and the overlying dura mater was heavily stained in these animals. Conclusions and clinical relevanceVariation in distribution of local anaesthetic solution can probably be overcome by deeper needle penetration of the epidural fat.

Distribution of new methylene blue injected into the caudal epidural space in cattle

To investigate the distribution of solutions injected into the first intercoccygeal epidural space, 24 adult, standing cattle were randomly assigned to 5-, 10- and 20-mL groups and injected with 0.12% new methylene blue (NMB) in 0.9% saline. Ten heifers received 1 mL NMB solution/100 kg of body weight. There was a significant correlation between the injected volume and the number of cranially stained spinal segments in three adult cattle groups (correlation coefficient R 2=0.46; P<0.0001). In three cattle, NMB solution did not distribute more than one spinal segment cranially from the injection site due either to fibrosis of the epidural tissue or to inadvertent intravenous administration into the epidural vein. The study showed that the larger the volume of solution injected, the greater the spread with increased individual variation. The results could form the basis for determining the volume of injection required and for evaluating the pharmacokinetics of anaesthetics used in caudal epidural anaesthesia.

Simultaneous determination of methylene blue and new methylene blue by slab optical waveguide spectroscopy and artificial neural networks

A slab optical waveguide (SOWG) has been used for study of adsorption of both methylene blue (MB) and new methylene blue (NMB) in liquid–solid interface. Adsorption characteristics of MB and NMB on both bare SOWG and silanized SOWG by octadecyltrichlorosilane (ODS) were compared. The simultaneous determinations of both MB and NMB were explored by flow injection SOWG spectrophotometric analysis and artificial neural networks (ANNs) for the first time. Concentrations of MB and NMB were estimated simultaneously with the ANNs. Results obtained with SOWG were compared with those got by conventional UV-visible spectrophotometry.

Carbon ceramic electrodes modified with sub-micron particles of new methylene blue (NMB) intercalated α-zirconium phosphate

New methylene blue-intercalated α-zirconium phosphate (NMBZrP) was synthesized in the presence of n-butylamine and characterized by powder XRD, FTIR, TEM and elemental analysis. Sub-micron particles of NMBZrP in deionized water were apt to deposit onto the surface of graphite powder to yield graphite powder-supported NMBZrP, which was subsequently dispersed into methyltrimethoxysilane-derived gels to fabricate surface-renewable, stable, rigid carbon ceramic electrodes containing new methylene blue. Cyclic voltammetric studies revealed that peak currents of the NMBZrP-modified electrode were surface-confined at low scan rates but diffusion-controlled at high scan rates. In addition, NMBZrP immobilized in a carbon ceramic matrix presented a two-electron, three-proton redox process in acidic aqueous solution in the pH range from 0.52 to 3.95.

Distribution of new methylene blue injected into the dorsolumbar epidural space in cows

Objective To describe the effect of injection volume and anatomy on the spread of new methylene blue (NMB) injected into the epidural space between the first and second lumbar vertebrae in cows.Study Design Prospective experimental study.Sample Population Thirteen nonpregnant cows.Methods Cows were randomly assigned to two groups. Group 1 received 5 mL and Group 2 received 10 mL of 0.12% NMB in 0.9% saline. The injection was made into the first interlumbar epidural space using a dorsal approach. The extent of cranial and caudal migration of the dye, as manifested by the staining of the epidural fat and dura mater, was measured.Results Mean ± SEM number (range) of stained vertebrae was significantly greater in the 10-mL group than in the 5-mL group, 4.4 ± 0.6 (T11 to L5) and 3.0 ± 0.2 (T12 to L3), respectively (p < 0.05). Linear regression analysis showed that the volume was significantly correlated with the number of stained vertebrae (R2 = 0.42, p = 0.016). In the dorsal and lateral aspect of the spinal cord, there were two types of distribution of NMB along the surface of the epidural fat: between the periosteum and epidural fat; and between the epidural fat and dura mater. Migration under the spinal cord occurred along the two longitudinal epidural veins.Conclusions and Clinical Relevance The larger the volume of solution injected into the first interlumbar epidural space, the greater the spread. Intrinsic anatomic factors, such as characteristics of epidural fat and veins, influence the epidural spread of injected solution and, consequently, epidural analgesia.

Estudo comparativo entre citopatologia e histopatologia no diagnóstico de neoplasias caninas

Foi realizado um estudo comparativo entre os diagnósticos citológico e histopatológico em diversas neoplasias de 150 cães, pelas colorações de Wright, May-Grünwald-Giemsa, Novo Azul de Metileno e Papanicolau. Colorações histológicas como Hematoxilina-Eosina, van Gieson, Sudan, Azul de Toluidina e Ácido Periódico de Schiff também foram empregadas. Os dados revelaram uma eficácia de ordem de 85,3% no diagnóstico citopatológico, considerando-se os resultados histopatológicos como corretos. Em 4,0% dos casos somente a origem embrionária das neoplasias foi estabelecida. Em 1,3% das neoplasias apenas o prognóstico foi determinado; o diagnóstico citológico diferiu da histopatologia em 8,1% dos casos. Em dois casos (1,3%) o diagnóstico citológico diferiu do histológico, mas um reexame determinou que o primeiro estava correto, o que elevou a sua eficácia para 86,6%. Entre as técnicas utilizadas, a punção aspirativa por agulha fina foi o melhor método para obter amostras. A citologia não foi adequada para o diagnóstico de neoplasias mamárias, dadas às variações morfológicas em diferentes áreas. A impressão em lâmina não é recomendada para análise de tumores mesenquimais e deve ser substituída pela citologia esfoliativa. O Wright revelou-se o método de coloração mais eficiente. As colorações adaptadas da histopatologia, van Gieson em leiomiomas e leiomiossarcomas, Sudan em lipomas e lipossarcomas, e Ácido Periódico de Schiff e Azul de Toluidina em mastocitomas, foram empregadas com sucesso fornecendo assim maior clareza de detalhes para as diversas neoformações de origem epitelial e mesenquimal.

Multiple Equilibria of Phenothiazine Dyes in Aqueous Cyclodextrin Solutions

The dimerization and inclusion complexation equilibria of six phenothiazine (PN) dyes with cyclodextrins (α-, β-, and γ-CDs) in aqueous media have been studied using absorption and fluorescence spectroscopy. The PN dyes used in this study are thionine (TH), azure A (AZA), methylene blue (MB), toluidine blue (TB), new methylene blue (NMB), and 1,9-dimethylmethylene blue (DMMB). The dimerization constants (KD) of the dyes having two methyl substituents at the phenothiazine ring (NMB and DMMB) are much greater than those of other dyes having unsubstituted rings, and the presence of methyl groups on the amine groups affects little the KD values. The positions of the monomer/dimer equilibria do not change with the presence of α-CD, while the addition of β-CD suppresses and γ-CD enhances the dimerization of the dyes except DMMB. The equilibrium constants for the inclusion complexation of the dye monomers and dimers with CDs are determined from the analysis of the dependence of the absorption spectra of the dye ...

Cephalad distribution of three differing volumes of new methylene blue injected into the epidural space in adult goats.

Epidural anesthesia and analgesia are popular regional anesthetic techniques in many animal species. However, we have not found any reports of studies in animals that have investigated the extent of cephalad migration and level of sensory blockade achieved based only on the volume of drug injected into the epidural space. The purpose of this study was to determine if there is a relationship between the volume (mL/kg) of an injectate injected epidurally and the extent of its cephalad migration within the epidural space. Twelve adult goats were randomly assigned to three treatment groups based on the volume of 0.12% New Methylene Blue (NMB), 0.1, 0.2, or 0.3 mL/kg, injected into the epidural space. The site and speed of injection, animal position, and direction of needle bevel were held constant. All injections were performed at the lumbo-sacral space immediately following euthanasia. At necropsy, the vertebral columns were transected longitudinally. The extent of cephalad migration of dye within the epidural space was easily determined by staining of the dura. Measurements were rounded to the nearest intervertebral space to which the dye had migrated. The individual making assessments was blinded to all treatments. In goats treated with 0.1, 0.2, or 0.3 mL/kg NMB, the number of stained spinal segments was 3.5 +/- 0.6, 6.5 +/- 0.9, and 8.8 +/- 0.6, (mean +/- SEM), respectively. Linear regression performed on the data was significant (P < .05) with R2 = 0.86. There was a strong linear relationship between volume (mL/kg) of epidurally injected NMB and cranial migration, with the larger volumes producing more cephalad spread within the epidural space. These results provide evidence for the volume of epidural injectate needed to produce a desired level of sensory blockade in adult goats.

Adsorptive Complex Wave of Tin(IV) with Some Thiazine Dyes.

Tin(IV) in a medium of sulfuric acid-oxalic acid with some thiazine dyes, e.g. new Methylene Blue (NMB) or Toluidine Blue (TB), at -0.60 V (vs. SCE) produced a highly sensitive adsorptive complex wave. The sensitivity was increased to about 16-times higher than that without those dyes in the above-mentioned medium. The detection limit was 0.8 ng/ml (6.7×10-9 mol/1) Sn(IV). The existing form and the apparent stability constant (k) of these complexes, the reversibility of the electrode process, the character of adsorption and the mechanism of the electrode reaction were investigated, and a series of constants and parameters were calculated. The proposed method was applied to determine trace tin in drinking-water samples and reagents with satisfactory results.