Cyclic AMP regulation of pro-vasoactive intestinal polypeptide/PHM-27 synthesis in human neuroblastoma cells

The mechanism of N6,O2'-dibutyryl adenosine 3':5'-monophosphate (Bt2cAMP) induction of pro-vasoactive intestinal polypeptide (VIP)/PHM-27 biosynthesis was investigated in human neuroblastoma cells in culture. When neuroblastoma cells were grown for 48 h in the presence of 1 mM Bt2cAMP, the synthesis of pro-VIP/PHM-27 was stimulated 11-fold. The amount of prepro-VIP/PHM-27 mRNA determined both by hybridization with cloned prepro-VIP/PHM-27 cDNA and a reticulocyte cell-free translation assay was also increased 11-fold in the Bt2cAMP-induced cells. Transcription of prepro-VIP/PHM-27 mRNA in isolated nuclei was observed in induced cells, but not in uninduced cells. Blot hybridization with prepro-VIP/PHM-27 cDNA of total nuclear RNA isolated from neuroblastoma cells revealed an RNA species corresponding to mature prepro-VIP/PHM-27 mRNA, and the amount of the RNA was markedly increased in the induced cells. The quantity of VIP/PHM-27 gene in the DNA of neuroblastoma cells was analyzed after hydrolysis with a restriction endonuclease, EcoRI. However, VIP/PHM-27 gene was not amplified in the induced cells. These results indicate that Bt2cAMP-induced pro-VIP/PHM-27 synthesis is achieved by enhancing the transcription rate of prepro-VIP/PHM-27 mRNA.

Biologic and biophysical markers of a live varicella vaccine strain (Oka): identification of clinical isolates from vaccine recipients

Possible biologic and biophysical markers of the Oka vaccine strain of varicella-zoster virus (VZV) were explored. The ratio between the infectivity of the vaccine strain in guinea-pig embryo fibroblasts and that in human embryo fibroblasts was consistently higher than the corresponding ratios for wild-type strains; this result seemed to correlate with the passage history of the vaccine strain in guinea-pig embryo fibroblasts. According to profiles of cleavage of digested DNA by various restriction endonucleases, the mobility of one fragment (K) produced by restriction endonuclease Hpa I was unique to the Oka strain. Nine clinical isolates from vaccine recipients (seven with varicella and two with zoster) were examined by both methods (infectivity and cleavage profiles) to determine whether or not these strains were vaccine derived. The laboratory judgments obtained by the two methods were in agreement and were consistent with clinical conclusions concerning five of the strains. Since the test of relative infectivity is simple and convenient, it is suitable for differentiation of the vaccine strain from other wild-type strains; if the results are not conclusive, profiles of cleavage by Hpa I may be helpful in reaching a definite judgment.

[Tumor immunity induced by local radiotherapy]

The tumor-specific immunopotential was obtained by local X-irradiation to tumor under certain condition. This radiation-induced tumor-specific immunity did not effectively manifest in in vivo system due to suppressor cells. Combined effect of radiotherapy and cyclophosphamide, which reduced presuppressor cells, was examined in the murine tumor system. C3H/He mice with transplantable Fibrosarcoma was used. Tumor was locally irradiated by 8MeV Electron beam (LMT-15). Tumors were treated when they grew at 8 +/- 1 mm in size. Tumor growth curve and tumor regrowth time were studied. Suppression of tumor growth was noticed in the combined treatment group of irradiation and cyclophosphamide. Treatment of cyclophosphamide after irradiation was effective to tumor.

A neurochemical study of developmental impairment of the brain caused by the administration of cytosine arabinoside during the fetal or neonatal period of rats

Injection of pregnant rats with cytosine arabinoside (ara-C) (280 mg/kg) on day 15 of gestation caused a significant rise (about two times the control value) in monoamine concentrations (norepinephrine, dopamine, and serotonin) accompanied by a decrease (about 60% of the control) in the brain weight and DNA content in the cerebrum of the offspring at 60 days of age. When neonatal rats were injected with ara-C (30 mg/kg/day) for four consecutive days from the fourth to seventh days after birth, a decrease of DNA content per cerebellum and an elevation of monoamine concentrations in the cerebellum were found. However, the total content of each monoamine per cerebrum or cerebellum showed no difference from the control. These results suggest that monoaminergic neurons may remain intact, with normal monoaminergic synapses compressed into a small brain volume. The neonatal administration of ara-C caused an elevation of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) (EC 3.1.4.37) activity and myelin protein content in the cerebellum, suggesting a relative increase in myelin concentration as a result of hypoplasia of granule cells.

Preliminary crystallographic study of Bowman-Birk protease inhibitor (adzuki bean) and its complex with trypsin

Preliminary crystallographic studies of a Bowman-Birk type protease inhibitor, AB-I, from adzuki beans (Phaseolus angularis) 'Takara,' and its complex with trypsin were carried out. AB-I, MW 9100 with 82 amino acid residues, crystallizes in a trigonal space group, P3121 (or P3221), with the following unit cell dimensions: a = 68.7, c = 99.7 A. The asymmetric unit contains two dimer molecules. Structure analysis at 5 A resolution revealed the rough appearance of the dimer. The complex between AB-I and trypsin also could be crystallized in a tetragonal space group, P41212 (or P43212), with the unit cell dimensions, a = 55.4 and c = 181.5 A, and Z = 8. The crystallinity seems to be much better than that of the crystals of the inhibitor alone. The other type of inhibitor from adzuki bean, AB-IIa, was also crystallized.

Insect fat body phosphorylase kinase is Ca2+-independent and acts even at 0 degrees C

Fat body glycogen phosphorylase in some overwintering insects is known to be activated by cold and, therefore, this enzyme acts as a key enzyme that regulates the production of glycerol or trehalose from glycogen during winter. In this paper we report the mechanism of phosphorylase activation by cold: the major phosphorylase kinase (EC 2.7.1.38) of fat body is bound to glycogen and functions at 0 degrees C, whereas phosphorylase phosphatase does not; thus this may cause a slow but continuous accumulation of the active form of phosphorylase in the cold.