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- Bis(β-lactosyl)-fullerene as novel class of glycolipids useful for the detection and the decontamination of biological toxins of the Ricinus communis family. [JOURNAL ARTICLE]
- Beilstein J Org Chem 2014.:1504-1512.
Glycosyl-fullerenes were first used as decontaminants against ricin, a lactose recognition proteotoxin in the Ricinus communis family. A fullerene glycoconjugate carrying two lactose units was synthesized by a [3 + 2] cycloaddition reaction between C60 and the azide group in 6-azidohexyl β-lactoside per-O-acetate. A colloidal aqueous solution with brown color was prepared from deprotected bis(lactosyl)-C60 and was found stable for more than 6 months keeping its red color. Upon mixing with an aqueous solution of Ricinus communis agglutinin (RCA120), the colloidal solution soon caused precipitations, while becoming colorless and transparent. In contrast, a solution of concanavalin A (Con A) caused no apparent change, indicating that the precipitation was caused specifically by carbohydrate-protein interactions. This notable phenomenon was quantified by means of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the results were discussed in terms of detection and decontamination of the deadly biological toxin in the Ricinus communis family.
- Identification of sialylated glycoproteins in doxorubicin-treated hepatoma cells with glycoproteomic analyses. [JOURNAL ARTICLE]
- J Proteome Res 2014 Aug 26.
Sialylation is one of the most important types of glycosylation involved in carcinogenesis and establishment of cancer stemness. We previously showed that increased sialylation is a characteristic glycan change in cancer stem cells (CSCs) from hepatocellular carcinoma. However, the identities of glycoproteins targeted for sialylation remain unknown. In the present study, we identified glycoproteins targeted for sialylation in doxorubicin (DXR)-treated hepatocarcinoma cell line, Huh7, using glycoproteomic analyses. Since CSCs constitute a small subset of cells within carcinoma cell lines, it is difficult to identify sialylated proteins using general glycoproteomic strategies. It is known that treatment with anti-cancer drug can condense CSCs, we used DXR to concentrate CSCs. In DXR-treated Huh7 cells, isobaric tag for relative and absolute quantitation (iTRAQ) analysis identified 17 sialylated glycoproteins. Most of the identified glycoproteins were cancer-associated proteins. Furthermore, two proteins of approximately 70 kDa were detected using Sambucus sieboldoana agglutinin (SSA) blot analysis and identified as beta-galactosidase and alpha-2-HS-glycoprotein (fetuin-A) by SSA precipitation followed by liquid chromatography-tandem mass spectrometry analyses. Sialylation levels of fetuin-A were increased in DXR-treated Huh7 cell lysates. These changes in sialylation of glycoproteins might be involved in the establishment of cancer stemness.
- Two jacalin-related lectins from seeds of the African breadfruit (Treculia africana L.). [JOURNAL ARTICLE]
- Biosci Biotechnol Biochem 2014 Aug 26.:1-9.
Two jacalin-related lectins (JRLs) were purified by mannose-agarose and melibiose-agarose from seeds of Treculia africana. One is galactose-recognizing JRL (gJRL), named T. africana agglutinin-G (TAA-G), and another one is mannose-recognizing JRL (mJRL), TAA-M. The yields of the two lectins from the seed flour were approximately 7.0 mg/g for gJRL and 7.2 mg/g for mJRL. The primary structure of TAA-G was determined by protein sequencing of lysyl endopeptic peptides and chymotryptic peptides. The sequence identity of TAA-G to other gJRLs was around 70%. Two-residue insertion was found around the sugar-binding sites, compared with the sequences of other gJRLs. Crystallographic studies on other gJRLs have shown that the primary sugar-binding site of gJRLs can accommodate Gal, GalNAc, and GalNAc residue of T-antigen (Galβ1-3GalNAcα-). However, hemagglutination inhibition and glycan array showed that TAA-G did not recognize GalNAc itself and T-antigen. TAA-G preferred melibiose and core 3 O-glycan.
- Sero-prevalence of brucellosis in occupationally exposed human beings of Himachal Pradesh (India). [Journal Article]
- J Commun Dis 2012 Jun; 44(2):91-5.
The chief objective of respective study was to investigate the seroprevalence of brucellosis among occupationally exposed human beings in Himachal Pradesh. A total of 165 serum samples that were obtained from human beings from various regions of the state were screened through a battery of serological tests which included RBPT, STAT, 2-MET, dot-ELISA and indirect-ELISA. 165 of human sera samples included 42 from veterinarians, 40 shepherds, 35 livestock owners, 20 workers at veterinary hospitals/clinics, 16 abattoir workers and 12 veterinary pharmacists. The overall seroprevalence of brucellosis among occupationally exposed human beings was observed to be 6.66% showing highest in abattoir workers (18.75%) followed by pharmacists (8.33%), veterinarians (7.14%), and livestock owners (5.71%) and shepherds (5.00%). In humans it is prevalent as an occult infection or under diagnosed disease, especially; in case of abattoir workers the highest seropositivity for brucella agglutinins was observed. Indirect-ELISA and Dot-ELISA proved best in the diagnosis of brucellosis.
- Multifunctional targeting daunorubicin plus quinacrine liposomes, modified by wheat germ agglutinin and tamoxifen, for treating brain glioma and glioma stem cells. [JOURNAL ARTICLE]
- Oncotarget 2014 Aug 15; 5(15):6497-6511.
Most anticancer drugs are not able to cross the blood-brain barrier (BBB) effectively while surgery and radiation therapy cannot eradicate brain glioma cells and glioma stem cells (GSCs), hence resulting in poor prognosis with high recurrence rates. In the present study, a kind of multifunctional targeting daunorubicin plus quinacrine liposomes was developed for treating brain glioma and GSCs. Evaluations were performed on in-vitro BBB model, murine glioma cells, GSCs, and GSCs bearing mice. Results showed that the multifunctional targeting daunorubicin plus quinacrine liposomes exhibited evident capabilities in crossing the BBB, in killing glioma cells and GSCs and in diminishing brain glioma in mice. Action mechanism studies indicated that the enhanced efficacy of the multifunctional targeting drugs-loaded liposomes could be due to the following aspects: evading the rapid elimination from blood circulation; crossing the BBB effectively; improving drug uptake by glioma cells and GSCs; down-regulating the overexpressed ABC transporters; inducing apoptosis of GSCs via up-regulating apoptotic receptor/ligand (Fas/Fasl), activating apoptotic enzymes (caspases 8, 9 and 3), activating pro-apoptotic proteins (Bax and Bok), activating tumor suppressor protein (P53) and suppressing anti-apoptotic proteins (Bcl-2 and Mcl-1). In conclusion, the multifunctional targeting daunorubicin plus quinacrine liposomes could be used as a potential therapy for treating brain glioma and GSCs.
- Complement activation by salivary agglutinin is secretor status dependent. [JOURNAL ARTICLE]
- Biol Chem 2014 Jul 24.
Abstract After mucosal damage or gingival inflammation, complement proteins leak into the oral cavity and mix with salivary proteins such as salivary agglutinin (SAG/gp-340/DMBT1). This protein is encoded by the gene Deleted in Malignant Brain Tumors 1 (DMBT1), and it aggregates bacteria, viruses and fungi, and activates the lectin pathway of the complement system. In the lectin pathway, carbohydrate structures on pathogens or altered self cells are recognized. SAG is highly glycosylated, partly on the basis of the donor's blood group status. Whereas secretors express Lewis b, Lewis y, and antigens from the ABO-blood group system on SAG, non-secretors do not. Through MBL binding and C4 deposition assays, we aimed to identify the chemical structures on SAG which are responsible for complement activation. The complement-activating properties of SAG were completely abolished by oxidation of its carbohydrate moiety. SAG-mediated activation of complement was also inhibited in the presence of saccharides such as fucose and Lewis b carbohydrates, and also after pretreatment with the fucose-binding lectin, Anguilla anguilla agglutinin. Complement activation was significantly (p<0.01) higher in secretors than in non-secretors. Our results suggest that fucose-rich oligosaccharide sidechains, such as Lewis b antigens, are involved in the activation of complement by SAG.
- Cell cycle-dependent O-GlcNAc modification of tobacco histones and their interaction with the tobacco lectin. [JOURNAL ARTICLE]
- Plant Physiol Biochem 2014 Aug 6.:151-158.
The Nicotiana tabacum agglutinin or Nictaba is a nucleocytoplasmic lectin that is expressed in tobacco after the plants have been exposed to jasmonate treatment or insect herbivory. Nictaba specifically recognizes GlcNAc residues. Recently, it was shown that Nictaba is interacting in vitro with the core histone proteins from calf thymus. Assuming that plant histones - similar to their animal counterparts - undergo O-GlcNAcylation, this interaction presumably occurs through binding of the lectin to the O-GlcNAc modification present on the histones. Hereupon, the question was raised whether this modification also occurs in plants and if it is cell cycle dependent. To this end, histones were purified from tobacco BY-2 suspension cells and the presence of O-GlcNAc modifications was checked. Concomitantly, O-GlcNAcylation of histone proteins was studied. Our data show that similar to animal histones plant histones are modified by O-GlcNAc in a cell cycle-dependent fashion. In addition, the interaction between Nictaba and tobacco histones was confirmed using lectin chromatography and far Western blot analysis. Collectively these findings suggest that Nictaba can act as a modulator of gene transcription through its interaction with core histones.
- Rituximab in the treatment of autoimmune haemolytic anaemia. [JOURNAL ARTICLE]
- Br J Clin Pharmacol 2014 Aug 19.
Rituximab is a B-cell depleting monoclonal antibody that is gaining popularity as an effective therapy for many autoimmune cytopenias. This article systematically evaluates its therapeutic efficacy in the treatment of different types of autoimmune haemolytic anaemia. We conclude that there is sufficient evidence to recommend it as a second line therapy for warm autoimmune haemolytic anaemia (wAIHA) either as monotherapy or combined therapy. Evidence from a single randomized controlled trial suggests that it may also be more efficacious as first-line therapy in combination with steroids than steroids alone. A fewer number of studies have assessed its role in cold autoimmune haemolytic anaemia (cAIHA) and cold agglutinin disease (CAD) with success rates varying from 45-66%. In the absence of alternative definitive therapy, rituximab should be considered for patients with symptomatic CAD and significant haemolysis. Case reports of its efficacy in mixed autoimmune haemolytic anaemias are available but evidence from case series or larger cohorts are nonexistent.
- Paradoxical findings in direct antiglobulin test and classification of agglutinating autoantibodies using eluates and monospecific anti-human globulin sera. [JOURNAL ARTICLE]
- Vox Sang 2014 Aug 7.
Agglutinating autoantibodies are rarely the cause of autoimmune haemolytic anaemia (AIHA) of warm type. These antibodies can be difficult to classify, and serological testing may result in confusion. Here, we describe the occurrence of paradoxical results in direct antiglobulin test (DAT) and a simple technique for the characterization of such antibodies.Seven patients with AIHA were included in this study. Serological testing was performed using standard techniques. Classification of autoantibodies was performed by preincubation of the eluates from patients' red blood cells (RBCs) with monospecific anti-human globulin sera (mAHG).Strong autoagglutination of patients' RBCs was observed in six of seven cases, with the identification of panagglutinating serum antibodies in three patients. Initially, cold agglutinins with high thermal amplitude were suggested in four patients, and IgM warm autoantibodies were suggested in the remaining three patients. However, inhibition of the eluates revealed autoantibodies of IgA class in two patients, of IgM class in three other cases and of IgG class in two patients. The results of DAT were confusing due to paradoxical effects of mAHG and/or strong autoagglutination.Strongly agglutinating autoantibodies can be a source of confusion and can be classified by inhibition experiments using eluates and monospecific antibodies.
- Evaluation of glycophenotype in prostatic neoplasm by chemiluminescent assay. [Journal Article]
- Int J Clin Exp Pathol 2014; 7(7):3800-8.
This work aimed to evaluate the glycophenotype in normal prostate, bening prostatic hyperplasia (BPH) and prostatic adenocarcinoma (PCa) tissues by a chemiluminescent method. Concanavalin A (Con A), Ulex europaeus agglutinin (UEA-I) and Peanut agglutinin (PNA) lectins were conjugated to acridinium ester (lectins-AE). These conjugates remained capable to recognize their specific carbohydrates. Tissue samples were incubated with lectins-AE. The chemiluminescence of the tissue-lectin-AE complex was expressed in relative light units (RLU). Transformed tissues (0.25 cm(2) by 8 µm of thickness) showed statistical significant lower α-D-glucose/mannose (BPH: 226,931 ± 17,436; PCa: 239,520 ± 12,398) and Gal-β(1-3)-GalNAc (BPH: 28,754 ± 2,157; PCa: 16,728 ± 1,204) expression than normal tissues (367,566 ± 48,550 and 409,289 ± 22,336, respectively). However, higher α-L-fucose expression was observed in PCa (251,118 ± 14,193) in relation to normal (200,979 ± 21,318) and BHP (169,758 ± 10,264) tissues. It was observed an expressive decreasing of the values of RLU by inhibition of the interaction between tissues and lectins-AE using their specific carbohydrates. The relationship between RLU and tissue area showed a linear correlation for all lectin-AE in both transformed tissues. These results indicated that the used method is an efficient tool for specific, sensitive and quantitative analyses of prostatic glycophenotype.