Lymphocyte activation by a polysaccharide fraction separated from hot water extracts of Angelica acutiloba Kitagawa.

The action of a polysaccharide fraction obtained from hot water extracts of Angelica acutiloba Kitagawa, termed as Angelica immunostimulating polysaccharide (AIP) fraction, on murine lymphocytes participating in antibody responses was investigated. When AIP fraction was injected concomitantly into mice immunized with antigens, immunoglobulin M (IgM) and IgG antibody responses against sheep erythrocytes (SRBC) increased significantly, but IgM response against T-independent antigens such as trinitrophenylated lipopolysaccharide (TNP-LPS) and TNP-Ficoll did not augment. Murine B lymphocytes were polyclonally activated in vitro and in vivo by AIP fraction to differentiate into antibody-forming cells as functionally matured cells.

Alteration of lipid peroxide and endogenous antioxidant contents in retina of streptozotocin-induced diabetic rats: effect of vitamin A administration.

Possible involvement of lipid peroxide (LPO) in the occurrence of diabetic retinal lesion was investigated using streptozotocin-induced diabetic rats. Young male Wistar rats weighing 100-150 g were made diabetic by daily intraperitoneal injection of 30 mg/kg streptozotocin (STZ) for 5 days. Five weeks after the termination of STZ-treatment, when animals maintained typical hyperglycemia, the tissue level of LPO, estimated by the thiobarbituric acid method in the presence of 0.

Immunopotentiator separated from hot water extract of the seed of Benincasa cerifera Savi (Tohgashi).

The separation and properties of a new immuno-potentiator, Benincasa cerifera mitogen (BCM) fraction, were investigated. BCM fraction was separated from hot water extract of the seed of Benincasa cerifera Savi (Tohgashi) by gel filtration using Sepharose 4B. BCM fraction is a heteropolymer consisting of uronic acid, neutral sugars, protein, and phosphorus.

Mitogenic and polyclonal B cell activation activities of synthetic lipid A analogues.

The activation of murine B cells and macrophages by synthetic lipid A analogues, solubilized with triethylamine and complexed with bovine serum albumin, were investigated in vitro. The analogues used are nonphosphorylated, C-1 or C-4' monophosphorylated and C-1,4' diphosphorylated derivatives of beta-1,6-linked D-glucosamine disaccharide possessing both ester- and amide-bound fatty acid substituents. They were divided into 4 groups, A, B, C and D in terms of the fatty acid substitution.

Activation of peritoneal macrophages by berberine-type alkaloids in terms of induction of cytostatic activity.

The antitumour alkaloids, berberine and coralyne were investigated in terms of their ability to induce chemiluminescent responses and cytostatic activity in macrophages against tumour cells in vitro. Berberine hydrochloride and sulfate, and coralyne chloride, which had no direct tumoristatic activities at a concentration of less than 0.15 micrograms/ml, activated macrophages to inhibit the incorporation of tritiated thymidine into EL4 leukemic cells.

Cell cycle requisite for vesicular stomatitis virus replication in T lymphocytes activated with concanavalin A.

The relationship between the development of virus plaque forming cells (V-PFC) and the blastogenic response of T cells activated with concanavalin A (Con A) was investigated in connection with the cell cycle using a modified virus plaque assay (VPA) which facilitated the quantitative detection of T lymphoblasts with low susceptibility to infection by vesicular stomatitis virus (vsv). The generation of V-PFC markedly decreased when DNA synthesis inhibitors such as thymidine, hydroxyurea and cytosine arabinoside (Ara C) were added to spleen cell cultures stimulated with Con A, while the addition of a mitotic inhibitor, Colcemid, to the cultures caused only partial reduction of V-PFC development. These results indicate that the S to G2 phases of the first cell cycle are essential for vsv-replication or V-PFC development in Con A activated T cells.

Activation of distinct T cell subsets involved in IgM antibody response of mice by pertussis toxin from Bordetella pertussis strain Maeno.

T cell activation mechanisms in the spleen induced by pertussis toxin (PT) were investigated. The degree of T cell activation was judged from results of helper activity assessed by measuring the in vitro antitrinitrophenyl (TNP) IgM antibody response. When mice were injected intraperitoneally with 4 X 10(5) sheep erythrocytes (SRBC) and concomitantly given an intravenous injection with 10 micrograms of PT 4 days previously, significant generation of nonspecific helper T cells was observed unless primed T cells were stimulated in vitro with TNP-SRBC.

High frequency detection of different T-cell subsets in mice by a modified virus plaque assay.

Different T-cell subsets participating in immune responses were detected at a high frequency by a modified virus plaque assay (VPA). By using the modified VPA, different activated T-cell subsets generated in primary immune responses, helper and suppressor T cells participating in antibody formation, and effector T cells involved in the delayed-type hypersensitivity (DTH) reaction were enumerated directly without in vitro antigen stimulation. The frequency of detection in immune systems used was 7.

Taurine biosynthesis in frog retina: effects of light and dark adaptations.

The retinal uptake and metabolism of cysteine, a precursor for taurine biosynthesis, were analysed using the bull frog. The [14C] cysteine uptake into isolated retina had some specific properties: It was rather temperature independent, required Na ions, was inhibited by ouabain but not by dinitrophenol, and exhibited saturation kinetics composed of two components. When retinal homogenate was incubated with 12-30 microM of L-[U-14C]cysteine, the accumulation of labeled alanine, cysteine sulfinic acid (CSA), cysteic acid (CA), hypotaurine, and taurine was detected.

Inhibition of macrophage function by 2-chloroadenosine.

The inhibitory action of 2-chloroadenosine (2-CA) on murine macrophages was investigated by means of concanavalin A (Con A)-induced T-cell proliferative response and of in vitro antibody response to sheep red blood cells (SRBC). The viability of peritoneal exudate cells (PEC) markedly decreased when treated with 0.1 mM 2-CA at 37 degrees C for 2 hr before cell cultures.

A modulating role of mercurials-sensitive sulfhydryl groups in synaptic GABA receptor binding.

The specific binding of GABA (?-aminobutyric acid) agonist (3)H-muscimol, to synaptic membranes from the rat brain showed a significant increase, when the membranous preparations were treated with a low concentration (10(?4)-10(?5)M) of mercurial sulfhydryl reagents such as p-chloromercuribenzoate and mercuric chloride. This activation in GABA receptor binding was bicuculline-sensitive, and was partially restored by subsequent treatments with 10 mM cysteine, penicillamine, or mercaptoethanol. Scatchard analysis of the binding revealed that this activation was due to the increase in the affinity of both high and low affinity bindings sites but not in the B(max) values.

Characterization of guanylate cyclase in frog retina using nitrosoguanidine and superoxide dismutase.

Guanylate cyclase in the membrane fraction of rod outer segments (ROS-membrane) from the frog retina showed an extremely high activity but had no responsiveness to NaN(3) (+catalase), nitrosoguanidine or superoxide dismutase. These compounds, however, markedly activated the enzyme in a soluble fraction from the retina. Although the activation of the soluble guanylate cyclase by superoxide dismutase was completely repressed by KCN, diethyldithiocarbamate and hemoglobin, these drugs had no effect on the basal enzyme activity in ROS-membrane.

Alteration of GABA system in frog retina following short light and dark adaptations - a quantitative comparison with retinal taurine.

Effect of short light and dark adaptations on retinal GABA and taurine was studied using bull frog (Rana catesbiana). The retinal GABA was increased significantly in light-adapted state, and this increase was accompanied by the increases of L-glutamate decarboxylase (GAD) activity and [3H]-GABA release. The activation of retinal GABA-transaminase succinic semialdehyde dehydrogenase (GABA-T:SSADH) was also observed after a lag period of several hours.

Process of cap formation of messenger RNA by vaccinia virus particles carrying an organized enzymes system.

Vaccinia virus mRNAs carry the cap structure m7G5'pppAm- or m7G5'pppGm- at the 5'-terminus, which is synthesized by a series of RNA polymerase and capping enzymes contained in the virus particle. The process of the cap formation at the 5'-terminus of mRNA was studied using an in vitro system under similar conditions to those of vaccinia virus multiplication in its host cell. After adding a methyl-group donor, methyl-3H-S-adenosylmethionine, the oligonucleotides, which were the de novo synthesized 5'-terminal part of mRNA, were isolated from the RNA-synthesizing virion at appropriate time intervals, and were analysed.

Alteration of metabolism of retinal taurine following prolonged light and dark adaptation: a quantitative comparison with gamma-aminobutyric acid (GABA).

Alteration of metabolism of taurine in prolonged light- and dark-adapted frog retinae were studied in comparison with that of gamma-aminobutyric acid (GABA) and the following results were obtained. (1) Statistically significant alterations in retinal taurine, an increase in dark-adapted, and a decrease in light-adapted states, respectively, occurred when frogs were adapted continuously to light or dark for more than 3 weeks. Under the same experimental conditions, no alteration in retinal GABA was noted.

Methylation of 5'-5' confronting dinucleotides by vaccinia associated enzyme system.

Methylation of a series of the 5'-5' confronting dinucleotides containing various number of phosphates was examined by the use of virion enzyme system of vaccinia virus. Methylation was absolutely dependent on the number of interposed phosphate groups between 5'-5' confronting dinucleotides, showing maximum efficiency in the 3 phosphate compound corresponding to the blocked 5'-terminus (cap) of an eukaryotic mRNA. Methylation, if any, occurred only at the 7-position of guanine residue, but not at the 2' position of ribose moiety.