Fluorescent analysis of alpha-keto acids in serum and urine by high-performance liquid chromatography

A selective procedure using synthetic substrates for determination of exo-1,4,-beta-glucanases in a mixture of exoglucanases , endoglucanases , and beta-glucosidases is formulated. The heterobiosides , p- nithrophenyl -beta-D- cellobioside ( pNPC ) or p-nitrophenyl-beta-D-lactoside ( pNPL ), were used as selective substrates for the measurement of exoglucanase activity. The exoglucanases (especially cellobiohydrolases , which split off cellobiose units from the nonreducing end of the cellulose chain) specifically act on the agluconic bond (between p-nitrophenyl and the disaccharide moiety) and not on the holosidic bond (between the two glucose units of cellobiose). The interfering effect of beta-glucosidase, which acts on both agluconic and holosidic bonds, is overcome by the addition of D-glucono-1,5-delta-lactone, a specific inhibitor of beta-glucosidases. The interference of endoglucanases , which also act on both agluconic and holosidic bonds, can be compensated for by prior standardization of the assay procedure with a purified endoglucanase from the studied mixture of cellulases.     

Analysis of water in Autonomous Biological Systems (ABS) samples.

Several soluble components, peptidase and amino acids, and carbon isotopic ratio in the water retrieved from flight experiments of Autonomous Biological Systems (ABS) as well as ground control samples are analyzed to interpret the condition, dynamics, material balance of the ABS ecosystems. Organic carbons in flight samples were found to be more abundant compared with the control ones, which suggested the uniform ecosystems in low gravity might easily dissolve more soluble components. The Mir-1997 flight sample showed higher C/N ratio probably because of the dissolution of carbon-rich plant materials.     

Differentiation of Langerhans Cells from Interdigitating Cells Using CD1a and S-100 Protein Antibodies

The present study shows that Langerhans cells can be differentiated from Interdigitating cells at the light microscopic level. Superficial lymph nodes and skin taken from necropsies and the lymph nodes of dermatopathic lymphadenopathy (DPL) were used for this experiment. Sections of lymph node and skin were embedded using the acetone, methyl benzoate and xylene (AMeX) method and dendritic cells were immunostained with anti S-100 protein antibody (S-100, and OKT-6 (CD1a) using the restaining method. Langerhans cells in the skin were positive for both CD1a and S-100. Dendritic cells positive for both CD1a and S-100, and dendritic cells positive for S-100, but not for CD1a were observed in superficial lymph nodes. In normal superficial lymph nodes, there were more interdigitating cells than Langerhans cells. The majority of the dendritic cells in the DPL were Langerhans cells. We conclude that the S-100 and CD1a positive cells are Langerhans cells, and the S-100 positive-CD1a negative cells are interdigitating cells.     

Chloroplast DNA phylogeography of Fagus crenata (Fagaceae) in Japan

 CpDNA variation in Japanese beech, Fagus crenata (Fagaceae), was studied in 45 populations distributed throughout the species' range. Two cpDNA regions were sequenced: the non-coding region between the trnL (UAA) 5′exon and trnF (GAA), and the trnK region (including matK). Thirteen distinct cpDNA haplotypes were recognized and each haplotype was found to be geographically structured. Two major clades (I and II+III) were revealed in phylogenetic analyses among the haplotypes using F. sylvatica as an outgroup. The haplotypes of Clade I were distributed mainly along the Japan Sea side of the Japanese Archipelago, while those of Clade II+III occurred chiefly along the Pacific Ocean side. Consequently, the distribution of the two major cpDNA clades suggests that there were two migration routes in the history of F. crenata; one along the Japan Sea and the other along the Pacific Ocean side of the Japanese Islands. Received March 19, 2001 Accepted November 22, 2001     

Depolarization-Induced Increase in Surface Binding and Internalization of 125I-Nerve Growth Factor by PC 12 Pheochromocytoma Cells

The binding and internalization of 125I-nerve growth factor (NGF) by PC12 pheochromocytoma cells was studied as a function of extracellular potassium concentration. Both surface-bound and internalized fractions of 125I-NGF associated with the cells under depolarizing conditions (50 mM K+) increased to 144 +/- 28% (average +/- SEM, six different cell preparations) and to 176 +/- 12% (n = 6), respectively, of those observed at 6.0 mM K+. Scatchard-type analysis of the data indicates increased sites for the binding and internalization of iodinated NGF by the cells. Similar enhancement was observed for cells treated with NGF as well. This voltage-dependent phenomenon was reversible, and also observed in the presence of veratridine. Moreover, withdrawal of extracellular Ca2+ abolished high K+-induced modulation of 125I-NGF binding and internalization, indicating that this effect may be mediated by Ca2+.     

Modulation of brain progestin and glucocorticoid receptors by unsaturated fatty acid and phospholipid

In an attempt to learn how nonsteroidal factors modulate brain progestin and glucocorticoid receptors, the effects of saturated and unsaturated fatty acids, and phosphatidylinositol on the binding of [3H]R5020 or [3H]dexamethasone, determined by sucrose density gradient and gel filtration on LH20, were examined in the cerebral cortical cytosol from 10-day-old female rats which contain a considerable amount of progestin and glucocorticoid receptors. Unsaturated fatty acids such as oleic (C18:1), arachidonic (C20:4) and docosahexaenoic acid (C22:4) depressed the [3H]R5020 or [3H]dexamethasone binding in increasing order, but saturated fatty acids had no effect. Arachidonic and docosahexaenoic acids, which were strong inhibitors, lowered the binding dose dependently. The fatty acid inhibition on brain progestin and glucocorticoid receptors was thus a function of acid dose and degree of acid unsaturation. Interestingly, prostaglandin D2 did not show any effect. Among phospholipids tested the inhibitory effect of phosphatidylinositol on the [3H]R5020 binding was evident, but no significant effect was found with phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine or sphingomyelin. The phosphatidylinositol inhibition was dose dependent. Analysis on kinetics and Scatchard plot have revealed the noncompetitive type of inhibition by arachidonic acid and phosphatidylinositol. From these results it is suggested that the unsaturated nonestrified fatty acid, arachidonic acid, and phosphoinositides modulate the brain progestin and, possibly, glucocorticoid receptors through their binding at sites different from steroid binding sites on the respective receptor molecules.     

A low-temperature-sensitive intermediate state between S2 and S3 in photosynthetic water oxidation deduced by means of thermoluminescence measurements

The temperature dependence of S-state transitions in Photosystem II was measured by means of thermoluminescence using two different protocols for low-temperature flash excitation: protocol A, “last flash at low temperature”, and protocol B, “all flashes at low temperature”. Comparison of the temperature-dependence curves obtained by these two protocols revealed a marked difference particular for the three-flash experiments. The difference was attributed to the formation of a low-temperature sensitive precursor state between S₂ and S₃. The state is formed by two flash illumination given at −5 to −50°C, spontaneously transforms to normal S₃ on dark warming, and is not converted to S₀ by the 3rd flash. The precursor state was tentatively assigned to an S₃ in which H⁺ release is not completed.     

Stereoselective total synthesis of ceramide Di-, Tri- and tetrahexosides of wheat flour

The first total synthesis of glycosphingolipids isolated from wheat flour has been achieved in a regio- and stereo-controlled manner.Abbreviations THF tetrahydrofuran - DMF dimethylformamide Part 53 in the series Synthetic Studies on Cell Surface Glycans     

Membrane viscosity of lymphocytes and influence of phytohemagglutinin

The membrane viscosity of peripheral blood lymphocytes (PBLs) of equine, bovine and canine was measured by the use of time-resolved fluorescence depolarization technique with 1, 6-diphenyl-1,3,5-hexatriene (DPH). The viscosity values were 0.55, 0.59 and 0.50 poise for equine, bovine and canine PBLs, respectively. These values were compared with steady-state anisotropies and order parameters measured from electron spin resonance (ESR) of 5-doxyl stearic acid. Both values were increased with increase of viscosity. The fluid property of the membranes stimulated with phytohemagglutinin-P (PHA) was measured with steady-state fluorescence anisotropy and ESR. Little change of membrane fluidity was recognized with both methods during the stimulation with PHA. It appears that PHA activation process for these lymphocytes does not included large increase of the membrane fluidity which significantly accelerate the diffusion velocity of receptors in the plasma membrane.