Comparative studies on the inhibitory effects of interferon on various strains of herpes simplex viruses in vitro

The sensitivities to human leukocyte interferon of 10 strains of Herpes simplex virus (HSV) type 1 and 3 strains of type 2 were compared. All the strains were sensitive to interferon, although their sensitivities were less than that of vesicular stomatitis virus (VSV). There was no significant difference in the sensitivities to interferon of HSV type 1 and type-2 or among different strains of a given type of HSV. Nor was there any difference between the sensitivities of 5-iodo-2'-deoxyuridine (IDU)-sensitive and resistant strains isolated from the same patients. These results suggest that interferon should be useful in therapy of HSV infection.     

Effects of anions on ADP-stimulated aggregation of bovine blood platelets

ADP-stimulated aggregation of bovine blood platelets was observed in media containing isotonic potassium salts of various monovalent anions. The aggregation depended on the anion in the medium, the order of aggregation being Cl^?, Br^?>I^?>SCN^?, $\text{ClO}{}_4{}^{\mathrm{?}}$. After 30-min incubation, the extent of aggregation of platelets in Cl^? or Br^? medium was little changed, whereas, that in SCN^? or $\text{ClO}{}_4{}^{\mathrm{?}}$ medium was remarkably decreased. This anion dependency of aggregation may be due to change in the membrane potential.     

Sexual difference and organ specificity of the effect of estradiol on carbonic anhydrase and Mg(2+)-HCO3(-)-ATPase activities isolated from duodenal mucosa and kidney cortex of male and female rats: preliminary study with crude enzyme samples.

Effects of the s.c. administration of various doses of estradiol propionate (E.P.; 25-500 micrograms/kg) on the activities of carbonic anhydrase (CA), Mg(2+)-dependent ATPase and Mg(2+)-dependent, HCO3(-)-stimulated ATPase (Mg(2+)-HCO3(-)-ATPase) in rat duodenal mucosa and kidney cortex, and on body weight, organ weight and serum concentrations of testosterone and estradiol-17 beta, were examined in adult male, female, testectomized and ovariectomized rats. In normal male rats, activities of cytosol CA and brush border Mg(2+)-HCO3(-)-ATPase in the kidney were increased in a dose-dependent manner and reached 1.6- and 2-fold of controls, respectively, after consecutive administration (daily for 7 days) of 500 micrograms E.P. with no changes in either enzyme activities in duodenal mucosa. The positive correlations (P less than 0.01) were observed by linear regression analysis between serum concentration of estradiol-17 beta and kidney cytosol CA or kidney brush border Mg(2+)-HCO3(-)-ATPase activities. In normal female rats, activities of cytosol CA and brush border Mg(2+)-HCO3(-)-ATPase in the duodenal mucosa, and brush border Mg(2+)-HCO3(-)-ATPase activity in the kidney were increased by E.P. administration (100 and 500 micrograms/kg, daily for 7 days), however, kidney cytosol CA activity did not change by any dosage. Behavior of a part of both enzymes to E.P. in testectomized rats was altered almost in the same way to that observed in normal female rats and vice versa in ovariectomized rats. Body weight was decreased, in general, by consecutive administration of E.P. in a dose-dependent manner, and kidney weight was increased by E.P. in both male and female rats.     

A Novel Glial Growth Inhibitory Factor, Gliostatin, Derived from Neurofibroma

Neurofibroma tissue was investigated for the presence of glial growth modulators that would suppress the proliferation of glial cells. A novel endogenous polypeptide inhibitor of proliferation and DNA synthesis in glial cells, gliostatin, was purified from the extracts of neurofibroma by a procedure comprising dye and anion-exchange column chromatography, and HPLC. A monoclonal antibody raised against partially purified gliostatin showed no cross-reactivity with known cytokines, but adsorbed the growth inhibitory activity of gliostatin and immunochemically visualized the putative gliostatin bands on western blot analyses. Although the product showed an apparent M(r) of 100,000 accompanied by an inhibitory activity on gel filtration column chromatography, it migrated at a lower apparent M(r) of 50,000 under the reducing conditions on western blotting, indicating that a homodimeric structure of native gliostatin consisted of 50-kDa subcomponents. Gliostatin was a potent growth inhibitor acting at nanomolar concentrations against all glial tumor cells and glia maturation factor-stimulated astroblasts, but not neuronal cells.     

Putative inositol 1,4,5-trisphosphate binding proteins in rat brain cytosol.

In previous works, we synthesized a series of inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) analogs, with a substituent on the second carbon of the inositol ring. Using these analogs, the Ins(1,4,5)P3 affinity media were also synthesized (Hirata, M., Watanabe, Y., Ishimatsu, T., Yanaga, F., Koga, T., and Ozaki, S. (1990) Biochem. Biophys. Res. Commun. 168, 379-386). When the cytosol fraction from the rat brain was applied to an Ins(1,4,5)P3 affinity column, an eluate with a 2 M NaCl solution was found to have remarkable Ins(1,4,5)P3-binding activity. The active fraction was further fractionated with gel filtration chromatography, and two proteins with an apparent molecular mass of 130 or 85 kDa were found to be Ins(1,4,5)P3-binding proteins but with no Ins(1,4,5)P3 metabolizing activities. Partial amino acid sequences determined after proteolysis and reversed-phase chromatography revealed that the protein with an apparent molecular mass of 85 kDa is the delta-isozyme of phospholipase C and that of 130 kDa has no sequence the same as the Ins(1,4,5)P3-recognizing proteins hitherto examined. Ins(1,4,5)P3 at concentrations greater than 1 microM strongly inhibited 85-kDa phospholipase C delta activity, without changing its dependence on the concentrations of free Ca2+ and H+. Among inositol phosphates examined, Ins(3,4,5,6)P4 inhibited the binding of [3H]Ins(1,4,5)P3 to the 130-kDa protein at much the same concentrations as seen with Ins(1,4,5)P3. This report seems to be the first evidence for the presence of soluble Ins(1,4,5)P3-binding proteins in the rat brain, one of which is the delta isozyme of phospholipase C.     

Evaluation of platelet calcium ion mobilization by the use of various divalent ions.

Divalent ion mobilization in human platelets was evaluated with Fura-2 fluorescence changes induced by Ca2+, Sr2+, Ba2+ and Mn2+. Extracellular Ca2+, Sr2+ and Ba2+ all entered thrombin-stimulated platelets. These divalent ions were also able to refill the intracellular Ca2+ storage sites which had been depleted of Ca2+ by ionomycin treatment, and were released from the storage sites upon thrombin stimulation. However, only the refilling of the storage sites with Ca2+ and Sr2+, but not with Ba2+, were capable of suppressing the opening state of Ca2+ channels assessed with Mn2+ influx. Efflux of intracellularly accumulated divalent ions was observed with Ca2+ and Sr2+ but not with Ba2+. These findings indicate that there are subtle differences in the Ca(2+)-binding domains of the various systems involved in Ca2+ mobilization in platelets, some of which discriminate Ba2+ while accepting Sr2+.     

Improved culture conditions for somatic embryogenesis from Asparagus officinalis L. using an aseptic ventilative filter

Summary Calli were induced from the crown of seedlings or lateral bud of young spears of Asparagus officinalis L. on Linsmaier and Skoog's (LS) solid-medium supplemented with 5 M 2,4-dichlorophenoxyacetic acid (2,4-D). Embryogenic callus was selected from induced calli and proliferated in LS liquid medium supplemented with 5 M 2,4-D. Non-vitrified somatic embryos were formed and efficiently developed into club-shaped embryos in LS hormone-free medium with 1 % gelrite in a culture vessel capped with an aseptic ventilative filter. Non-vitrified club-shaped embryos developed into normal plants when transferred to half-strength LS medium without hormones, and 0.8 % agar. Carbon dioxide concentration and moisture content inside the culture vessels were measured, and their effect on embryo development is discussed.     

Molecular cloning and nucleotide sequencing of the gene for E. coli cAMP receptor protein.

The crp gene of E. coli, which codes for cAMP receptor protein (CRP), has been cloned in the plasmid pBR322 on the basis of a genetic complementation. One of the recombinant plasmids, pHA1, was shown to direct the synthesis of CRP in a cell-free system. The location of the crp gene was determined by constructing subclones carrying various portions of pHA1. The nucleotide sequence of the crp gene has been determined. The coding region consists of 627 base pairs (bp), which specify a protein of 209 amino acids. The predicted amino acid sequence from the DNA sequence is consistent with the amino acid sequence partially known and the amino acid composition of CRP. After the coding region, there is a G-C rich inverted repeat sequence followed by a run of Ts, which could be a terminator of the crp gene. A possible promoter sequence was found about 180 bp upstream from the initiation codon and was shown to act as a promoter in vitro and in vivo. There are two dyad symmetry regions in a 167 bp leader sequence.     

Pulse sequences generated by a degenerate analog neuron model

The response characteristics of an electronic neuron model proposed by the authors are investigated. Periodic stimulating pulse sequences with a fixed frequency are applied to the analog neuron model and the response pulse sequences are studied. In the degenerate case, the state transition of the neuron model during one period of the stimulating pulse sequence is described by a first order piecewise linear difference equation with a jump. It is shown that the periodic response pulse sequences of the neuron model belong to a special class of pulse sequences generated by a simple algorithm, and that the relation between the pulse width (or amplitude) of the stimulating pulse and the firing rate of the neuron model takes the form of an extended Cantor function.