Sigma-Aldrich

Methylene Blue; Methylene blue is used to stain blood films/smears used in cytology and to stain RNA or DNA for viewing under the microscope or on hybridization membranes.

Methylene Blue for microscopy, concentrate according to Ehrlich, concentrated, aqueous solution 61-73-4

for microscopy, concentrate according to Ehrlich, concentrated, aqueous solution

Methylene Blue solution for microscopy, concentrate according to Ehrlich, concentrated, aqueous solution

Methylene Blue solution

Real-time fluorescence image-guided oncologic surgery

Interferon-gamma is a crucial activator of early host immune defense against Mycobacterium ulcerans infection in mice

Antimicrobial Photodynamic Therapy (APDT) Action Based on Nanostructured Photosensitizers

CLEC9A modulates macrophage-mediated neutrophil recruitment in response to heat-killed Mycobacterium tuberculosis H37Ra

Pathogen reduction technology treatment of platelets, plasma and whole blood using riboflavin and UV light

Reprogramming human amniotic fluid stem cells to functional pluripotency by manipulation of culture conditions

Despite recent developments in preoperative breast cancer imaging, intraoperative localization of tumor tissue can be challenging, resulting in tumor-positive resection margins during breast conserving surgery. Based on certain physicochemical similarities between Technetium((99m)Tc)-sestamibi (MIBI), an SPECT radiodiagnostic with a sensitivity of 83-90% to detect breast cancer preoperatively, and the near-infrared (NIR) fluorophore Methylene Blue (MB), we hypothesized that MB might detect breast cancer intraoperatively using NIR fluorescence imaging. Twenty-four patients with breast cancer, planned for surgical resection, were included. Patients were divided in 2 administration groups, which differed with respect to the timing of MB administration. N = 12 patients per group were administered 1.0 mg/kg MB intravenously either immediately or 3 h before surgery. The mini-FLARE imaging system was used to identify the NIR fluorescent signal during surgery and on post-resected specimens transferred to the pathology department. Results were confirmed by NIR fluorescence microscopy. 20/24 (83%) of breast tumors (carcinoma in N = 21 and ductal carcinoma in situ in N = 3) were identified in the resected specimen using NIR fluorescence imaging. Patients with non-detectable tumors were significantly older. No significant relation to receptor status or tumor grade was seen. Overall tumor-to-background ratio (TBR) was 2.4 ± 0.8. There was no significant difference between TBR and background signal between administration groups. In 2/4 patients with positive resection margins, breast cancer tissue identified in the wound bed during surgery would have changed surgical management. Histology confirmed the concordance of fluorescence signal and tumor tissue. This feasibility study demonstrated an overall breast cancer identification rate using MB of 83%, with real-time intraoperative guidance having the potential to alter patient management.

Real-time intraoperative detection of breast cancer using near-infrared fluorescence imaging and Methylene Blue.

With the debate over extent of lymphadenectomy in endometrial cancer, sentinel lymph node (SLN) mapping may provide a focused approach to evaluate the most relevant lymph nodes (LN) while minimizing the complications. We evaluated SLN mapping using filtered technetium(99), indocyanine green (ICG), and blue dye. Prospective evaluation of 100 patients who underwent SLN mapping by using submucosal and deep stromal cervical injections of technetium(99), ICG, and blue dye as part of the staging for endometrial cancer. 286 SLNs were mapped (2.9 per patient) in 92% of patients. The bilateral detection rate was 76%. ICG had a significantly higher SLN detection rate than blue dye in both overall (87% vs 71%, respectively; p=0.005) and bilateral (65% vs 43%, respectively; p=0.002) detection, but similar SLN detection rates compared to technetium(99) in both overall (87% vs 88%, respectively; p=0.83) and bilateral (65% vs 71%, respectively; p=0.36) detection. In eight cases, the SLN was in the para-aortic area and in 14 cases in the pre-sacral, hypogastric vein, or parametrial area. In nine cases, the SLN was positive for metastasis, and in seven cases the SLN was the only positive node. One SLN was falsely negative. No complications or anaphylactic reactions occurred. Intra-operative SLN mapping using cervical injection is feasible in patients with endometrial cancer and yields adequate detection rates. It allows mapping of SLNs in areas (pre-sacral, hypogastric vein, parametrial) not routinely sampled. Given the poorer performance of blue dye, surgeons may omit its use if a combination of ICG and technetium(99) is used.

Comparing indocyanine green, technetium, and blue dye for sentinel lymph node mapping in endometrial cancer.

Some members of the family Enterobacteriaceae ferment sugars via the mixed-acid fermentation pathway. This yields large amounts of acids, causing strong and sometimes even lethal acidification of the environment. Other family members employ the 2,3-butanediol fermentation pathway, which generates comparatively less acidic and more neutral end products, such as acetoin and 2,3-butanediol. In this work, we equipped Escherichia coli MG1655 with the budAB operon, encoding the acetoin pathway, from Serratia plymuthica RVH1 and investigated how this affected the ability of E. coli to cope with acid stress during growth. Acetoin fermentation prevented lethal medium acidification by E. coli in lysogeny broth (LB) supplemented with glucose. It also supported growth and higher stationary-phase cell densities in acidified LB broth with glucose (pH 4.10 to 4.50) and in tomato juice (pH 4.40 to 5.00) and reduced the minimal pH at which growth could be initiated. On the other hand, the acetoin-producing strain was outcompeted by the nonproducer in a mixed-culture experiment at low pH, suggesting a fitness cost associated with acetoin production. Finally, we showed that acetoin production profoundly changes the appearance of E. coli on several diagnostic culture media. Natural E. coli strains that have laterally acquired budAB genes may therefore have escaped detection thus far. This study demonstrates the potential importance of acetoin fermentation in the ecology of E. coli in the food chain and contributes to a better understanding of the microbiological stability and safety of acidic foods.

Acetoin synthesis acquisition favors Escherichia coli growth at low pH.

Riboflavin, also known as vitamin B2, is transported across the biological membrane into various organs by transport systems. Riboflavin transporter RFVT3 is expressed in the small intestine and has been suggested to localize in the apical membranes of the intestinal epithelial cells. In this study, we investigated the functional involvement of RFVT3 in riboflavin absorption using intestinal epithelial T84 cells and mouse small intestine. T84 cells expressed RFVT3 and conserved unidirectional riboflavin transport corresponding to intestinal absorption. Apical [(3)H]riboflavin uptake was pH-dependent in T84 cells. This uptake was not affected by Na(+) depletion at apical pH 6.0, although it was significantly decreased at apical pH 7.4. The [(3)H]riboflavin uptake from the apical side of T84 cells was prominently inhibited by the RFVT3 selective inhibitor methylene blue and significantly decreased by transfection of RFVT3-small-interfering RNA. In the gastrointestinal tract, RFVT3 was expressed in the jejunum and ileum. Mouse jejunal and ileal permeabilities of [(3)H]riboflavin were measured by the in situ closed-loop method and were significantly reduced by methylene blue. These results strongly suggest that RFVT3 would functionally be involved in riboflavin absorption in the apical membranes of intestinal epithelial cells.

Functional involvement of RFVT3/SLC52A3 in intestinal riboflavin absorption.

Methylene blue inhibits the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway, decreasing vasodilation and increasing responsiveness to vasopressors. It is reported to improve haemodynamics in distributive shock from various causes including septicaemia and post-cardiac surgery. Reports of use in overdose are limited. We describe the use of methylene blue to treat a case of refractory distributive shock following a mixed drug poisoning. A 41-year-old male presented following reported ingestion of 18 g extended-release quetiapine, 10 g controlled-release carbamazepine, 240 mg fluoxetine, 35 g enteric-coated sodium valproate and 375 mg oxazepam. He was comatose and intubated on presentation. Progressive hypotension developed. Echocardiogram revealed a hyperdynamic left ventricle, suggesting distributive shock. The patient remained hypotensive despite intravenous fluid boluses, escalating vasopressor infusions. Arterial blood gas revealed metabolic acidaemia and high lactate. Methylene blue was administered as loading-dose of 1.5 mg/kg and continuous infusion (1.5 mg/kg/h for 12 h, then 0.75 mg/kg/h for 12 h) resulting in rapid improvement in haemodynamic parameters and weaning of vasopressors. Serum quetiapine concentration was 18600 ng/mL (30-160 ng/mL), collected at the time of peak toxicity. Severe quetiapine poisoning produces hypotension primarily from alpha-adrenoreceptor antagonism. Methylene blue may have utility in the treatment of distributive shock resulting from poisoning refractory to standard vasopressor therapy.

Methylene blue used in the treatment of refractory shock resulting from drug poisoning.

Podoplanin (PDPN) is a unique transmembrane receptor that promotes tumor cell motility. Indeed, PDPN may serve as a chemotherapeutic target for primary and metastatic cancer cells, particularly oral squamous cell carcinoma (OSCC) cells that cause most oral cancers. Here, we studied how a monoclonal antibody (NZ-1) and lectin (MASL) that target PDPN affect human OSCC cell motility and viability. Both reagents inhibited the migration of PDPN expressing OSCC cells at nanomolar concentrations before inhibiting cell viability at micromolar concentrations. In addition, both reagents induced mitochondrial membrane permeability transition to kill OSCC cells that express PDPN by caspase independent nonapoptotic necrosis. Furthermore, MASL displayed a surprisingly robust ability to target PDPN on OSCC cells within minutes of exposure, and significantly inhibited human OSCC dissemination in zebrafish embryos. Moreover, we report that human OSCC cells formed tumors that expressed PDPN in mice, and induced PDPN expression in infiltrating host murine cancer associated fibroblasts. Taken together, these data suggest that antibodies and lectins may be utilized to combat OSCC and other cancers that express PDPN.

Antibody and lectin target podoplanin to inhibit oral squamous carcinoma cell migration and viability by distinct mechanisms.

Human pluripotent stem cells (hPSCs) tend to acquire genomic aberrations in culture, the most common of which is trisomy of chromosome 12. Here we dissect the cellular and molecular implications of this trisomy in hPSCs. Global gene expression analyses reveal that trisomy 12 profoundly affects the gene expression profile of hPSCs, inducing a transcriptional programme similar to that of germ cell tumours. Comparison of proliferation, differentiation and apoptosis between diploid and aneuploid hPSCs shows that trisomy 12 significantly increases the proliferation rate of hPSCs, mainly as a consequence of increased replication. Furthermore, trisomy 12 increases the tumorigenicity of hPSCs in vivo, inducing transcriptionally distinct teratomas from which pluripotent cells can be recovered. Last, a chemical screen of 89 anticancer drugs discovers that trisomy 12 raises the sensitivity of hPSCs to several replication inhibitors. Together, these findings demonstrate the extensive effect of trisomy 12 and highlight its perils for successful hPSC applications.

Aneuploidy induces profound changes in gene expression, proliferation and tumorigenicity of human pluripotent stem cells.

Teleost fishes retain populations of adult stem/progenitor cells within multiple primary sensory processing structures of the mature brain. Though it has commonly been thought that their ability to give rise to adult-born neurons is mainly associated with continuous growth throughout life, whether a relationship exists between the processing function of these structures and the addition of new neurons remains unexplored. We investigated the ultrastructural organisation and modality-specific neurogenic plasticity of niches located in chemosensory (olfactory bulb, vagal lobe) and visual processing (periventricular grey zone, torus longitudinalis) structures of the adult zebrafish (Danio rerio) brain. Transmission electron microscopy showed that the cytoarchitecture of sensory niches includes many of the same cellular morphologies described in forebrain niches. We demonstrate that cells with a radial-glial phenotype are present in chemosensory niches, while the niche of the caudal tectum contains putative neuroepithelial-like cells instead. This was supported by immunohistochemical evidence showing an absence of glial markers, including glial fibrillary acidic protein, glutamine synthetase, and S100β in the tectum. By exposing animals to sensory assays we further illustrate that stem/progenitor cells and their neuronal progeny within sensory structures respond to modality-specific stimulation at distinct stages in the process of adult neurogenesis - chemosensory niches at the level of neuronal survival and visual niches in the size of the stem/progenitor population. Our data suggest that the adult brain has the capacity for sensory-specific modulation of adult neurogenesis and that this property may be associated with the type of stem cell present in the niche.

Sensory-specific modulation of adult neurogenesis in sensory structures is associated with the type of stem cell present in the neurogenic niche of the zebrafish brain.

The purpose of this study was to evaluate the use of synthetic bone graft material as a filling material at the mandibular symphysis donor site of autologous bone in children. A blinded patient group comprised 20 patients with unilateral (UCLP) or bilateral (BCLP) cleft of lip and palate, all with an indication for alveolar cleft repair. The study took the form of a prospective randomized clinical trial. We used lateral cephalograms for the measurement of the symphyseal donor area defect both peroperatively and at 12 months postoperatively. The data obtained were digitalized and the treatment outcome expressed in numbers. Comparisons with a previous study were made. Histology of biopsies and CT scans were used for visualising bone formation. This study demonstrates that the micro-structured, resorbable calcium phosphate ceramic provides good regeneration properties for the repair of a critical size bony defect in children. One year postoperatively, the measurements taken from lateral cephalograms show that there is scarcely any visible residual defect. Histological investigations of the bone biopsies show solid, induced bone formation and almost complete resorption of the micro-structured calcium phosphate. The findings of this study (novel in children) indicate that micro-structured resorbable calcium phosphate is an excellent alternative to autologous bone. The digital findings showed a restored donor site defect significantly indicating the efficacy (i.e., osteoconductivity and resorbability) of this bone substitute. The biopsy histology demonstrated the overall presence of newly formed vital bone and the resorption of the bone substitute. Its use for grafting the alveolar cleft is currently researched and it may become the new standard. As co-morbidity and prolonged operation time at the donor operation site are inherent to the alveolar cleft repair procedure, the use of the described bone substitute is winning progress.

Micro-structured calcium phosphate ceramic for donor site repair after harvesting chin bone for grafting alveolar clefts in children.

The three oncogenes, ErbB receptors, Ras proteins and nucleolin may contribute to malignant transformation. Previously, we demonstrated that nucleolin could bind both Ras protein and ErbB receptors. We also showed that the crosstalk between the three proteins facilitates anchorage independent growth and tumor growth in nude mice, and that inhibition of this interaction in prostate and colon cancer cells reduces tumorigenicity. In the present study, we show that treatment with Ras and nucleolin inhibitors reduces the oncogenic effect induced by ErbB1 receptor in U87-MG cells. This combined treatment enhances cell death, reduces cell proliferation and cell migration. Moreover, we demonstrate a pivotal role of nucleolin in ErbB1 activation by its ligand. Nucleolin inhibitor prevents EGF-induced receptor activation and its downstream signaling followed by reduced proliferation. Furthermore, inhibition of Ras by Salirasib (FTS), mainly reduces cell viability and motility. The combined treatment, which targets both Ras and nucleolin, additively reduces tumorigenicity both in vitro and in vivo. These results suggest that targeting both nucleolin and Ras may represent an additional opportunity for inhibiting cancers, including glioblastoma, that are driven by these oncogenes.

Interfering with the interaction between ErbB1, nucleolin and Ras as a potential treatment for glioblastoma.

Epstein-Barr virus (EBV) is tightly associated with certain human cancers, but there is as yet no specific treatment against EBV-related diseases. The EBV-encoded EBNA1 protein is essential to maintain viral episomes and for viral persistence. As such, EBNA1 is expressed in all EBV-infected cells, and is highly antigenic. All infected individuals, including individuals with cancer, have CD8(+) T cells directed towards EBNA1 epitopes, yet the immune system fails to detect and destroy cells harboring the virus. EBV immune evasion depends on the capacity of the Gly-Ala repeat (GAr) domain of EBNA1 to inhibit the translation of its own mRNA in cis, thereby limiting the production of EBNA1-derived antigenic peptides presented by the major histocompatibility complex (MHC) class I pathway. Here we establish a yeast-based assay for monitoring GAr-dependent inhibition of translation. Using this assay we identify doxorubicin (DXR) as a compound that specifically interferes with the GAr effect on translation in yeast. DXR targets the topoisomerase-II-DNA complexes and thereby causes genomic damage. We show, however, that the genotoxic effect of DXR and various analogs thereof is uncoupled from the effect on GAr-mediated translation control. This is further supported by the observation that etoposide and teniposide, representing another class of topoisomerase-II-DNA targeting drugs, have no effect on GAr-mediated translation control. DXR and active analogs stimulate, in a GAr-dependent manner, EBNA1 expression in mammalian cells and overcome GAr-dependent restriction of MHC class I antigen presentation. These results validate our approach as an effective high-throughput screening assay to identify drugs that interfere with EBV immune evasion and, thus, constitute candidates for treating EBV-related diseases, in particular EBV-associated cancers.

A yeast-based assay identifies drugs that interfere with immune evasion of the Epstein-Barr virus.

The Michael hydratase - alcohol dehydrogenase (MhyADH) from Alicycliphilus denitrificans was previously identified as a bi-functional enzyme performing a hydration of α,β-unsaturated ketones and subsequent oxidation of the formed alcohols. The investigations of the bi-functionality were based on a spectrophotometric assay and an activity staining in a native gel of the dehydrogenase. New insights in the recently discovered organocatalytic Michael addition of water led to the conclusion that the previously performed experiments to identify MhyADH as a bi-functional enzyme and their results need to be reconsidered and the reliability of the methodology used needs to be critically evaluated.

Michael hydratase alcohol dehydrogenase or just alcohol dehydrogenase?

In the context of skeletal tissue development and repair, endochondral ossification has inspired a new approach to regenerate bone tissue in vivo using a cartilage intermediate as an osteoinductive template. The aim of this study was to investigate the behavior of mesenchymal stem cells (MSCs) in regard to in vitro cartilage formation and in vivo bone regeneration when combined with different three-dimensional (3D) scaffold materials, i.e., hydroxyapatite/tricalcium phosphate (HA/TCP) composite block, polyurethane (PU) foam, poly(lactic-co-glycolic acid)/poly(ε-caprolactone) electrospun fibers (PLGA/PCL) and collagen I gel. To this end, rat MSCs were seeded on these scaffolds and chondrogenically differentiated in vitro for 4 weeks followed by in vivo subcutaneous implantation for 8 weeks. Nonetheless, the quality and maturity of in vivo ectopic bone formation appeared to be scaffold/material-dependent. Eight weeks of implantation was not sufficient to ossify the entire PLGA/PCL constructs, albeit a comprehensive remodeling of the cartilage had occurred. For HA/TCP, PU and collagen I scaffolds, more mature bone formation with rich vascularity and marrow stroma development could be observed. These data suggest that chondrogenic priming of MSCs in the presence of different scaffold materials allows the establishment of reliable templates for generating functional endochondral bone tissue in vivo without using osteoinductive growth factors. The morphology and maturity of bone formation.

Performance of different three-dimensional scaffolds for in vivo endochondral bone generation.

The use of three-dimensional (3D) cultures may induce cardiac progenitor cells to synthesize their own extracellular matrix (ECM) and sarcomeric proteins to initiate cardiac differentiation. 3D cultures grown on synthetic scaffolds may favour the implantation and survival of stem cells for cell therapy when pharmacological therapies are not efficient in curing cardiovascular diseases and when organ transplantation remains the only treatment able to rescue the patient's life. Silk fibroin-based scaffolds may be used to increase cell affinity to biomaterials and may be chemically modified to improve cell adhesion. In the present study, porous, partially orientated and electrospun nanometric nets were used. Cardiac progenitor cells isolated from adult rats were seeded by capillarity in the 3D structures and cultured inside inserts for 21 days. Under this condition, the cells expressed a high level of sarcomeric and cardiac proteins and synthesized a great quantity of ECM. In particular, partially orientated scaffolds induced the synthesis of titin, which is a fundamental protein in sarcomere assembly.

Methylene Blue solution

for microscopy, concentrate according to Ehrlich, concentrated, aqueous solution

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Artículos con revisión científica externa.

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Methylene Blue solution

for microscopy, concentrate according to Ehrlich, concentrated, aqueous solution

Propiedades

Nivel de calidad

grado

formulario

calidad

caducidad

concentración

densidad

εmax

application(s)

temp. de almacenamiento

SMILES string

InChI

InChI key

Categorías relacionadas

Descripción

Descripción general

Aplicación

Información de seguridad

Código de clase de almacenamiento

WGK

Punto de inflamabilidad F

Punto de inflamabilidad C

Equipo de protección personal

Documentación

Certificado de Análisis

Certificado de origen

Más documentos

Presupuestos y pedidos

Artículos con revisión científica externa.

Servicio técnico

ε_max