The crystal structure of di-D-fructose anhydride III,produced by inulin D-fructotransferase

Reaction of methyl α-d-glucopyranoside and methyl α-d-mannopyranoside with alkaline hydrogen peroxide and a ferrous salt, at room temperature and below, afforded the corresponding d-glycosiduronic acids. On dehydration, the acids gave the corresponding gamma lactones, with a shift of the pyranoid ring to a furanoid ring. Surprisingly, the glycosidic methyl group was retained during the oxidation reactions and pyranose-furanose interconversions. This retention is rationalized by a mechanism involving formation of a pseudo-acyclic intermediate. Another unexpected reaction was the conversion of slightly moist methyl d-glucopyranosiduronolactone syrup, on standing for 5–6 days at room temperature, into crystalline d-glucofuranurono-6,3-lactone, and of methyl α-d-mannopyranosidurono-6,3-lactone into crystalline d-mannofuranurono-6,3-lactone.     

Accumulation of vanadium during embryogenesis in the vanadium-rich ascidian,Ascidia gemmata

It is a remarkable and previously unrecognized fact that ascidians, which are known to contain high levels of vanadium in their blood cells, begin to accumulate vanadium during embryogenesis. This study revealed that the accumulation starts quite dramatically 2 wk after fertilization, and 2 mo later, the amount of vanadium in larvae is 600,000 times higher than that in the unfertilized egg. These results were obtained by neutron activation analysis, a highly sensitive method for determining levels of vanadium, in theAscidia gemmata, the ascidian that contains the highest known levels of vanadium and accumulates vanadium at 150 mM in its blood cells, a concentration that corresponds to 4,000,000 times the concentration in sea-water.     

Immunocytochemical localization of cathepsins B,H, and L in the rat gastro-duodenal mucosa

Summary Cathepsins B, H, and L are representative cysteine proteinases in lysosomes of a large variety of cells. Previous immunochemical studies indicated the presence of these enzymes also in the gastrointestinal wall. Using specific antisera, the cellular and subcellular distribution of cathepsins B, H, and L in rat gastric (oxyntic and pyloric part) and duodenal mucosa was investigated by light and electron microscopical immunocytochemistry. The subtypes of cathepsins were distributed differently in the cellular constituents of the epithelia: Cathepsin B was localized to lysosomes of all cells except goblet cells. Cathepsin H was found predominantly in gastric parietal cells (lysosomes) and in secretion granules of pyloric gastrin and duodenal cholecystokinin cells. Cathepsin L immunoreactivities were weak and restricted to a minority of cells (gastric mucous cells, enterocytes). Interstitial cells of the lamina propria immunoreactive for cathepsins H and L were identified as macrophages. The present findings suggest a dual function of cathepsins in the gastro-duodenal mucosa. They (1) cleave enzymatically proteins and peptides ingested in lysosomes, and (2) they may be involved in the processing of biologically active peptides (enteric hormones) from their precursor proteins.     

Concentration-dependent inducing activity of activin A

Summary Human recombinant activin A, which is identical with erythroid differentiation factor (EDF), was tested for its mesoderm-inducing activity in concentrations from 0.3–50 ng/ml, using ectoderm of Xenopus late blastula (Stage 9) as the responding tissue. At a low concentration of activin A, blood-like cells, mesenchyme, and coelomic epithelium were induced; at a moderate concentration muscle and neural tissue, and at a high concentration notochord. Activin A thus induced all mesodermal tissues in a dose-dependent manner, such that a low dose induced ventral structures and a high dose induced dorsal structures. Activin may act as an intrinsic inducing molecule responsible for establishing the dorso-ventral axis in early Xenopus development. Offprint requests to: M. Asashima     

Chemical change involved in the oxidative reductive depolymerization of hyaluronic acid

The oxidative reductive depolymerization (ORD) of hyaluronate has been investigated. A solution of hyaluronate (Mr 4.07 x 10(5] in phosphate buffer (pH 7.2) was incubated in the presence of Fe2+ for 24 h at 37 degrees C under an oxygen atmosphere to yield depolymerized hyaluronate (ORD fragments; an average Mr of 2,600). The ORD fragments contain 21 and 24% less hexosamine and uronic acid, respectively, but no olefinic linkage. They were exhaustively digested with chondroitinase AC-II. The resulting oligosaccharides and monosaccharides were separated by gel filtration and ion-exchange chromatography, and their structures were determined by proton and carbon-13 NMR, fast atom bombardment mass spectrometry, and chromatographic techniques combined with chemical modifications. The following structures derived from the reducing ends of the ORD fragments were identified: 4,5-unsaturated GlcA(beta 1----3)-N-acetyl-D-glucosaminic acid (where GlcA- represents glucuronosyl-) (21%), 4,5-unsaturated GlcA(beta 1----3)GlcNAc(beta 1----3)-D-arabo-pentauronic acid (24%), and N-acetyl-D-glucosamine (51%). The following structures derived from the nonreducing ends were identified: L-threo-tetro-dialdosyl-(1----3)GlcNAc (a tentative structure, 8%), N-acetylhyalobiuronic acid (20%), and N-acetyl-D-glucosamine (45%). The results indicate that the ORD reaction of hyaluronate proceeds essentially by random destruction of unit monosaccharides due to oxygen-derived free radicals, followed by secondary hydrolytic cleavage of the resulting unstable glycosidic substituents.     

Organomercurial-volatilizing bacteria in the mercury-polluted sediment of Minamata Bay, Japan.

A total of 4,604 bacterial strains isolated from the sediments of Minamata Bay and nearby low-level-mercury stations (control stations) were screened for the ability to volatilize mercury from inorganic and organic mercurial compounds. The strains that volatilize mercury from several kinds of organomercurials were found only in the sediments of Minamata Bay.     

High-dose zolpidem abuse in a patient with insomnia comorbid with major depressive disorder

Sleep and Biological Rhythms - A 39-year-old married woman was referred to a psychiatry outpatient clinic for treatment of major depressive disorder (MDD). The dose of zolpidem she had been taking...     

EGFR T790M Mutation as a Possible Target for Immunotherapy; Identification of HLA-A*0201-Restricted T Cell Epitopes Derived from the EGFR T790M Mutation

Treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib and erlotinib, has achieved high clinical response rates in patients with non–small cell lung cancers (NSCLCs). However, over time, most tumors develop acquired resistance to EGFR-TKIs, which is associated with the secondary EGFR T790M resistance mutation in about half the cases. Currently there are no effective treatment options for patients with this resistance mutation. Here we identified two novel HLA-A*0201 (A2)-restricted T cell epitopes containing the mutated methionine residue of the EGFR T790M mutation, T790M-5 (MQLMPFGCLL) and T790M-7 (LIMQLMPFGCL), as potential targets for EGFR-TKI-resistant patients. When peripheral blood cells were repeatedly stimulated in vitro with these two peptides and assessed by antigen-specific IFN-γ secretion, T cell lines responsive to T790M-5 and T790M-7 were established in 5 of 6 (83%) and 3 of 6 (50%) healthy donors, respectively. Additionally, the T790M-5- and T790M-7-specific T cell lines displayed an MHC class I-restricted reactivity against NSCLC cell lines expressing both HLA-A2 and the T790M mutation. Interestingly, the NSCLC patients with antigen-specific T cell responses to these epitopes showed a significantly less frequency of EGFR-T790M mutation than those without them [1 of 7 (14%) vs 9 of 15 (60%); chi-squared test, p  =  0.0449], indicating the negative correlation between the immune responses to the EGFR-T790M-derived epitopes and the presence of EGFR-T790M mutation in NSCLC patients. This finding could possibly be explained by the hypothesis that immune responses to the mutated neo-antigens derived from T790M might prevent the emergence of tumor cell variants with the T790M resistance mutation in NSCLC patients during EGFR-TKI treatment. Together, our results suggest that the identified T cell epitopes might provide a novel immunotherapeutic approach for prevention and/or treatment of EGFR-TKI resistance with the secondary EGFR T790M resistance mutation in NSCLC patients.