Occurrence of Gibberella zeae strains that produce both nivalenol and deoxynivalenol.

By single ascospore isolation, several sets of asci containing eight ascospores were isolated from perithecia of Gibberella zeae. Of these sets, seven were investigated for their ability to produce 8-ketotrichothecene mycotoxins on rice grains. Analyses were made with gas chromatography-mass spectrometry and gas chromatography with 63Ni electron capture detection. Of 56 total isolates, 11 produced nivalenol, 4-acetylnivalenol, and deoxynivalenol, 1 produced nivalenol and deoxynivalenol, 7 produced deoxynivalenol and 3-acetyldeoxynivalenol, 19 produced deoxynivalenol and 15-acetyldeoxynivalenol, and 6 produced deoxynivalenol and both 15- and 3-acetyldeoxynivalenol. The remaining 12 isolates produced nivalenol and 4-acetylnivalenol. All isolates of G. zeae that we examined could produce 8-ketotrichothecenes in this investigation. This report is the first to demonstrate the presence of G. zeae isolates producing both nivalenol and deoxynivalenol. In addition, differences in the production between 3-acetyldeoxynivalenol and 15-acetyldeoxynivalenol are discussed in relation to culture conditions.     

Phalloidin-induced accumulation of myosin in rat hepatocytes is caused by suppression of autolysosome formation

Administration of phalloidin in vivo to rats causes marked changes in the distribution of actin and myosin in hepatocytes, which accompanies reduced bile flow. We have found that in hepatocytes treated with phalloidin for 3 and 7 days, cellular myosin content increased about 1.5-fold and 4.7-fold, respectively. In addition, total cell protein content and several marker enzyme activities were also elevated by 30-120% depending on the duration of phalloidin treatment. These observations allow us to speculate that phalloidin somehow elicits inhibition of cellular protein degradation, which results in the increase of these protein levels. To examine this possibility further, we analyzed leupeptin-induced density shift of phagolysosomes. In normal liver, the injection of leupeptin/E64c caused an increase in the density of both heterolysosomes and autolysosomes, due to retarded digestion of sequestered proteins as a result of the inhibition of lysosomal cathepsins. Accumulation, in these denser autolysosomes, of lactic dehydrogenase, pyruvate kinase, aldolase, and myosin was demonstrated by enzyme assays and immunoblot analysis. In the phalloidin-treated liver, the increase in the density of autolysosomes and the accumulation of above cytoplasmic enzymes were markedly inhibited. However, phalloidin did not affect the shift in the density of heterolysosomes. From these data, we concluded that autolysosome formation was specifically hindered in phalloidin-treated rat hepatocytes, which results in the reduction of autophagic protein degradation and eventual increase in intracellular protein levels.     

Identification of storage-protein messenger RNA of the fleshfly Sarcophaga peregrina.

Storage-protein mRNA was found to be abundant in poly(A)-containing RNA extracted from the fat-body of third-instar larvae of Sarcophaga peregrina (fleshfly). This RNA sedimented at the position of 19S on sucrose-density-gradient centrifugation and the product of its translation in vitro was 75K protein (protein of mol.wt. 75 000), which was precipitated specifically with antibody against storage protein. This product was suggested to contain a signal sequence that is missing in mature storage protein. The poly(A)-containing RNA was also found to contain much of another mRNA coding for 25K protein (protein of mol.wt. 25 000), but the function of this protein is unknown.     

Changes in the levels of prostaglandins and thromboxane and their roles in the accumulation of exudate in rat carrageenin-induced pleurisy — a profile analysis using gas chromatography-mass spectrometry —

Injection of γ-carrageenin into t he pleural cavity of rats caused the accumulation of the pleural exudate. When levels of prostaglandins (PGs) and thromboxane (TX) B₂ were quantified by gas chromatography-mass spectrometry as their methyl ester (ME)-dimethyllisopropylsilyl (DMiPS) ether or ME-methoxine-DMiPS ether derivatives, 6-keto-PGF_1α reached the maximum at 1 hr after carrageenin, then PGE₂ and TXB₂ showed peaks at 3 hr and waned off before 9 hr. he PGF_2α level was kept low, but PGD₂, PGE₁ and PGF_1α were not detected. Aspirin (100 mg/kg, i.p.) significantly decreased the PG and TXB₂ levels and suppressed the rate of plasma exudation until 5 hr, but did not at 7 hr, when it was measured by the amount of exuded pontamine sky blue injected intravenously. OKY-025 (300 mg/kg, i.p.), a selective TXA synthetase inhibitor, and tranylcypromine (20 mg/kg, i.p.), a PGI synthetase inhibitor, could not extensively inhibit the accumulation of the exudate. These results suggest that the cyclooxygenase products of arachidonic acid, particularly PGE₂, definitely play an important role in the exudation during the first 5 hr.     

Reaction of some D-glucobioses with 2,2-dimethoxypropane

Laminarabiose, cellobiose, and gentiobiose were acetonated with 2,2-dimethoxy-propane under various conditions. Two isopropylidene acetals in which the reducing D-glucose residue had the furanoid form were obtained from laminarabiose, and two, in which the reducing D-glucose residue formed the acyclic dimethyl acetal, from cellobiose. Gentiobiose gave both types of isopropylidene compound.     

A role of H+ flux in active Ca2+ transport into sarcoplasmic reticulum vesicles. II. H+ ejection during Ca2+ uptake

Proton efflux during Ca2+ transport into sarcoplasmic reticulum vesicles was examined. Although a rapid H+ ejection was observed during the initial phase of Ca2+ uptake and the amount of the liberated H+ was more than that due to hydrolysis of ATP, generation of a pH difference as a result of the H+ efflux could not be detected by direct pH measurement with a pH meter. Alkalinization of the inside of the vesicles during Ca2+ uptake was more precisely examined by flow dialysis assay and a significant uptake of acetate or salicylate into the vesicles was found, suggesting the generation of a small pH difference across the SR membrane. From these results, it was concluded that counter-transport of H+ was operative in Ca2+ uptake but that only a relatively small pH difference was generated as a result of the H+ efflux. The intrinsic buffering capacity of sarcoplasmic reticulum vesicles was measured and a relatively large value (130 nmol H+/pH unit/mg at pH 6.2) was obtained.     

Field test and experimental use of CYBEST model 2 for practical gynecologic mass screening

CYBEST is an automated cytologic screening system for uterine cancer utilizing a pattern-recognition image-analysis system. The prototype was developed in 1972 following fundamental studies of feature extraction, feature evaluation using ambiguity differential functions and segmentation of cell and nuclear images. Model 2 was developed in 1974 with an improved mechanism and function. The parameters employed are nuclear size, nuclear optical density, N/C ratio and nuclear shape. The data of field tests using 220 samples containing three cases of dysplasia, 110 cases of carcinoma and 107 nonmalignant cases were as follows: two false-negative cases (1.8%), 13 false positives (12.1%) and one reject (0.9%). This system was experimentally tested for practical mass population screening with 1,829 cases including 17 atypical cases (four epidermoid carcinomas). The data were as follows: no false-negative cases and 581 false-positive cases (32.1%). Of the latter, 311 cases (17.2%) were pathologic samples, such as severe cervicitis, senile colpitis, Trichomonas infestation, etc., and the remaining 270 cases (14.9%) were within physiologic limits, corresponding to true false-positive samples.     

Inhibitory effects of condiments and herbal drugs on the growth and toxin production of toxigenic fungi

The effects of thirteen kinds of powdered herbal drugs and seven kinds of commercial dry condiments on the growth and toxin production ofAspergillus parasiticus, A. flavus,A. ochraceus, andA. versicolor were observed by introducing these substances into culture media for mycotoxin production.Of the twenty samples tested, cinnamon bark completely inhibited the fungal growth, while the others only inhibited the toxin production.The inhibitors were easily extracted from the samples with solvents such as hot water, chloroform, or ethanol.The extracts from coptis, philodendron bark, mustard, green tea leaves, and zanthoxylum completely inhibited the aflatoxin production ofA. parasiticus, however, they had little or no inhibitory effect againstA. flavus.     

Bacterial oxidation of polyethylene glycol.

The metabolism of polyethylene glycol (PEG) was investigated with a synergistic, mixed culture of Flavobacterium and Pseudomonas species, which are individually unable to utilize PEGs. The PEG dehydrogenase linked with 2,6-dichlorophenolindophenol was found in the particulate fraction of sonic extracts and catalyzed the formation of a 2,4-dinitrophenylhydrazine-positive compound, possibly an an aldehyde. The enzyme has a wide substrate specificity towards PEGs: from diethylene glycol to PEG 20,000 Km values for tetraethylene glycol (TEG), PEG 400, and PEG 6,000 were 11, 1.7, and 15 mM, respectively. The metabolic products formed from TEG by intact cells were isolated and identified by combined gas chromatography-mass spectrometry as triethylene glycol and TEG-monocarboxylic acid plus small amounts of TEG-dicarboxylic acid, diethylene glycol, and ethylene glycol. From these enzymatic and analytical data, the following metabolic pathway was proposed for PEG: HO(CH2CH2O)nCH2CH2OH leads to HO(CH2CH2O)nCH2CHO leads to HO(CH2CH2O)nCH2COOH leads to HO(CH2CH2O)n-1CH2CH2OH.     

Conformational studies of poly-beta-1-naphthylmethyl-L-aspartate.

Poly-β-1-naphthylmethyl-L -aspartate and copolymers of β-1-naphthylmethyl-L -aspartate and γ-benzyl-L -glutamate were prepared. From the results obtained by a study of infrared and circular dichroism spectra, poly-β-1-naphthylmethyl-L -aspartate was found to be a left-handed α-helix both in the solid state and in solution. The fluorescence spectra of these polymers showed excimer emission of the naphthyl chromophores and gave some information about the arrangement of the side-chain chromophores. By optical titration experiments, it was found that an increasing amount of β-1-naphthylmethyl-L -aspartate residues in the copolymers induces a progressive instability of the helical structure.