Purification and properties of an endonuclease endogenous to rat-liver nuclei

An endonuclease endogenous to rat-liver nuclei has been purified by a series of chromatographic procedures and finally by isoelectric focusing (IEF) electrophoresis. The nuclease fraction prepared by the IEF electrophoresis (IEF fraction) showed a pI value of 5.7 and migrated as a single band to a molecular weight position of 46,000 on an SDS-polyacrylamide gel. The activity for single-stranded DNA was enhanced by 10 mM MgCl2 and/or by 5-15 mM MgCl2 in the presence of 2 mM CaCl2 (an optimum pH, 7.0), but was lowered by CaCl2 alone and inhibited strongly by ZnCl2 or MnCl2. The activity for duplex DNA was rather low, although an optimum condition was 10 mM MgCl2. In fact, even under this condition, the activity was about 40% lower than that for single-stranded DNA. Moreover, the IEF fraction formed single-strand nicks much more rapidly than double-strand cuts in pBR322 DNA, and preferentially produced deoxyadenosine 5'-monophosphate termini in the DNA. In addition, RNAase activity was also detected in this fraction.     

Expression of goat alpha-lactalbumin in Escherichia coli and its refolding to biologically active protein

A cDNA encoding the mature region of goat alpha-lactalbumin and the 3'-non-coding region was fused to cDNA of the N-terminal half of porcine adenylate kinase which had been placed under the control of the tac promoter in an expression vector in Escherichia coli. In addition, a methionine codon was inserted between the two cDNAs. When the plasmid carried the full-length 3'-non-coding region, little accumulation of the fused protein was observed. However, the deletion of two-thirds of the 3'-non-coding region produced significant expression of the fused protein in E. coli strain JM105. Since goat alpha-lactalbumin contains no methionine residue, the mature goat alpha-lactalbumin was isolated by CNBr digestion of the fused insoluble protein and refolded using thioredoxin. The homogeneous and biologically active goat alpha-lactalbumin was purified by Ca2+ ion-dependent hydrophobic chromatography.     

A case of sporotrichosis caused by two genetically differentSporothrix schenckii strains

A survey for the natural occurrence of Fusarium mycotoxins, deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEN), in Dutch cereals (totaling 29 samples) harvested in 1984/1985, showed that 90%, 79% and 62% of samples were contaminated with DON, NIV and ZEN, respectively. Average contents (ng/g) in the total of positive samples were 221 (DON), 123 (NIV) and 61 (ZEN). Among the cereals examined, the highest concentrations (ng/g) was 3198 (DON), 1875 (NIV) and 677 (ZEN) in a yellow corn sample for animal feed. The results of this survey show that Dutch cereals were relatively significantly contaminated with Fusarium mycotoxins.     

Ischemic flow threshold for striatal dopamine release in rats

To determine the level of cerebral blood flow reduction which causes striatal dopamine release, extracellular dopamine and cerebral blood flow was simultaneously determined using in vivo brain dialysis and a hydrogen clearance method, respectively, in the striatum of spontaneously hypertensive rats, before and during experimental cerebral ischemia. The ischemic flow threshold for neurotransmitter dopamine release was found to be 20% of the resting value or 8–10 ml/100g/min of cerebral blood flow, being similar to those for energy and membrane failures.     

Regional distribution of DNA and RNA in rat brain: A sensitive determination using high-performance liquid chromatography with electrochemical detection

DNA and RNA contents in 20 brain regions or nuclei of the rat were determined by a highly sensitive method using high-performance liquid chromatography with electrochemical detection. The high DNA and RNA contents were found in the hypothalamic nuclei, especially the median eminence-arcuate nucleus. These results may be available for the preparation of nucleic acids as the regional control.     

Lobeline production by hairy root culture of Lobelia inflata L.

Hairy roots were obtained following inoculation of the stems of Lobelia inflata L. with Agrobacterium rhizogenes strain ATCC 15834. These hairy roots contained agropine and mannopine. In addition, lobeline was detected by HPLC and confirmed by mass spectrometry. Various media were tested for the growth of hairy roots as well as for the content of lobeline in hairy roots. The growth rate of hairy roots cultured in Nitsch and Nitsch's medium was approximately one third of those cultured in other media. The lobeline content of hairy roots (18–54 g/g dry weight) cultured in these media was the same order of magnitude compared with that of roots of L. inflata (24 g/g dry weight) cultivated in pots. The hairy roots cultured in Nitsch and Nitsch's medium were morphologically different from those cultured in other media.Abbreviations MS medium Murashige and Skoog's medium - 1/2 MS medium one-half strength of the standard Murashige and Skoog's medium - B5 medium Gamborg's B5 medium - NN medium Nitsch and Nitsch's medium - FW fresh weight - DW dry weight     

Seed coat morphology and evolution in Celtidaceae and Ulmaceae (Urticales)

The seed coat surface morphology of Celtidaceae and Ulmaceae (Urticales) indicates a significant evolutionary diversity.Celtis, Chaetachme andPteroceltis (Celtidaceae) have a unique sculpturing with many crateriform holes; such holes occasionally sparsely occur in seeds ofAphananthe, Gironniera (Celtidaceae) andPlanera (Ulmaceae), but not in those of the nine remaining genera of the two families. The perforated seed coat further occurs in at least some genera of all other urticalean families. A pattern of its occurrence in families and genera suggest that the perforation represents a common archaic feature of all Urticales, rather than a feature derived many times independently within the order. The seed coat of Celtidaceae and Ulmaceae seems to have lately lost the holes probably by a neotenic evolution: one or more times within Celtidaceae, and one time in an ancestral line leading to all Ulmaceae. The derived reticulate seed coat surface sculpturing, which is shared byGironniera (Celtidaceae) and some Ulmaceae, is probably the result of parallel evolution. On the basis of evidence from seed coat morphology and other sources, close relationships ofLozanella, Parasponia andTrema within Celtidaceae, as well as variously distinct positions ofAmpelocera, Aphananthe andGironniera, are also discussed.     

Antimicrobial activities of polyether compounds of dinoflagellate origins

Twelve polyether compounds originating from dinoflagellates were tested for growth-inhibiting activities againstAspergillus niger, Penicillium funiculosum, Candida rugosa, Escherichia coli, Bacillus megaterium andStaphylococcus aureus by a paper disc method. These polyethers represent six groups of different skeletons and originate from three species;Prorocentrum lima, Dinophysis fortii andGambierdiscus toxicus. Potent antifungal activities were observed with okadaic acid and its two congeners, desulfated yessotoxin, and ciguatoxin but not with okadaic acid esters, prorocentrolide, pectenotoxin-1, yessotoxin, maitotoxin, and desulphated maitotoxin. The antifungal activities and mouse lethalities of the polyethers were markedly affected by slight modification of their structures. Antibacterial potency of the tested compounds was not significant.     

Functional and phenotypic analyses of interleukin 2-activated tumor-infiltrating lymphocytes

The tumor-infiltrating lymphocytes (TILs) were cultured with interleukin 2 (IL-2) to induce the activated killer cells possessing autologous tumor-killing activity, and analysed their cell surface phenotypes and assessed anti-tumor killing activity. Furthermore, the activated TILs were transferred into 7 patients adoptively resulting in complete remission in a patient with pancreatic cancer and partial remission in another patient with gastric cancer.The cytotoxic activities of activated TILs at 3 weeks-incubation was 72 ± 15, 42 ± 26, 27 ± 21 and 25 ± 15% against K562, Daudi, KATO-III and autologous tumor, respectively. The negative selection method, indicated that the killer cells recognizing autologous tumor cells consisted of CD4- or CD8-positive T lymphocytes and CD16- or CD56-positive natural killer cells. The activated TILs could not only lyse cultured tumor cell lines, but also autologous tumor cells.