First finding of urease-positive thermophilic strains of Campylobacter in river water in the Far East, namely, in Japan and their phenotypic and genotypic characterization

Two strains of urease-positive thermophilic Campylobacter (UPTC), CF89–12 and CF89–14, which were identified as UPTC by biochemical characterization, were found for the first time in river water in the Far East, namely, in Japan. The biochemical characteristics were identical to those of strains described previously by Bolton and colleagues. Furthermore, these two strains were positive for arylsulphatase. Consequently, it was demonstrated that UPTC may possibly be differentiated phenotypically from Campylobacter lari by the arylsulphatase test, as well as urease and nalidixic acid tests. Analysis by pulsed-field gel electrophoresis (PFGE) after digestion with Apa I, Sal I and Sma I, which were found to produce distributions of DNA fragments to be suitable for analysis of the genomic DNA from the thermophilic Campylobacter , respectively, demonstrated that these three restriction enzymes produced distributions of a relatively limited number of genomic DNA fragments and also demonstrated that the PFGE profiles obtained with the three restriction enzymes were indistinguishable between the two strains, respectively. The PFGE analysis and conventional fixed-field agarose gel electrophoresis suggested that the both genomes were approximately 1862 kb in length. Even though the two isolates of UPTC were isolated from water in different rivers in Japan, the results suggested that a single strain. as opposed to two distinct strains, was isolated. PFGE profiles after digestion with Sal I and Sma I, respectively, were also demonstrated to be distinctly different among strains isolated in Japan and previously in Europe. This is the first example of the isolation of UPTC from natural sources in countries other than those in Europe.     

Cryopreservation of wild mouse spermatozoa

Spermatozoa of wild mice from China, Czechoslovakia, Denmark, India, Japan and Switzerland were frozen and stored at -196 degrees C. After thawing, intact oocytes were inseminated in vitro with relatively high motility frozen-thawed mouse spermatozoa from Czechoslovakia, Denmark and India, while oocytes with a partially dissected zona were inseminated with low motility frozen-thawed spermatozoa from China, Japan and Switzerland. Embryos developing to the 2-cell stage from oocytes fertilized with frozen-thawed spermatozoa were transferred to the oviducts of female recipients on the first day of pseudopregnancy (day when a vaginal plug was confirmed). Successful embryo development to the 2-cell stage was 46 to 67%. Offspring resulted from 17 to 51% of these transferred 2-cell embryos.     

Light-Induced CREB Phosphorylation and Gene Expression in Rat Retinal Cells

Abstract: The signal pathway for light-induced expression of c- fos and the neuropeptide somatostatin (SS) in rat retinal cells was investigated. Flashing light induced c- fos and SS mRNA in the inner nuclear layer and the ganglion cell layer. As both c- fos and SS genes have a cyclic AMP response element (CRE) in their promoters, CRE-binding protein (CREB) phosphorylation in retinal cells was examined with a phospho-CREB-specific antibody. Both flashing light and administration of the L-type Ca²⁺ channel activator Bay K 8644 induced phosphorylation of CREB in the nuclei of the amacrine cells and the ganglion cells where c- fos /SS mRNAs were expressed. These cells could be double-stained with anti-calmodulin kinase II (anti-CaM kinase II) monoclonal antibody and phospho-CREB-specific polyclonal antiserum after Bay K 8644 administration, indicating the colocalization of phosphorylated CREB at Ser¹³³ and CaM kinase II in the neural retina.     

Two-step regulation of ecdysone-inducible late puffs in salivary glands of Drosophila melanogaster

Our previous study showed that some ecdysone-inducible late puffs could also be induced by a mild detergent (digitonin) in Drosophila salivary glands. However, they could only be induced at the stage immediately prior to when developmentally programmed puffing occurred, suggesting that these late puff loci were under two-step regulation. Using an in vitro culture of salivary glands, we have examined whether ecdysone or the protein products of early puff genes participate in either of the two steps of late puff regulation. This study has revealed that (i) the acquisition of digitonin-responsiveness (the first step) could be induced in vitro by incubating salivary glands with ecdysone; (ii) the first step could also be induced by protein synthesis inhibition even in the absence of ecdysone; (iii) the second step required both ecdysone and protein synthesis unless treated with digitonin; and (iv) the first step, rather than the second step, determines the timing of normal puff formation in the loci. These results suggest that, during normal development, ecdysone controls both steps by activating two types of early genes; the first type, whose function can be mimicked by cycloheximide, renders the loci responsive to digitonin and the second type, whose function can be mimicked by digitonin, activates the loci to form puffs.     

Regional Taste Sensitivity to NaCl: Relationship to Subject Age, Tongue Locus and Area of Stimulation

Using a signal detection procedure and a microprocessor-controlledgustometer, sensitivity to three concentrations of NaCl (0.01,0.1 and 1.0 M) was measured on the tongue tip, and on a region3.0 cm posterior to the tongue tip in 12 young (20–29years of age) and 12 elderly (70–79 years of age) subjects.Stimulus duration was 2 s; the sizes of the tongue areas stimulatedwere 12.5, 25 and 50 mm². On average, the young subjects weremore sensitive to NaCl on the tongue tip than on the more posteriorstimulation site and exhibited, at both tongue loci, an increasein detection performance as stimulus concentration increased.The elderly subjects, on the other hand, performed at chancelevel at both tongue loci for all three stimulus sizes and concentrationstested. No sex differences were observed. In the young subjects,the mean R-index increased monotonically as a function of stimulussize for the two highest NaCl concentrations at both tongueloci. A hyperbolic function provided the best fit to these dataat the tongue tip, and an exponential function at the more posteriortongue region, implying a different pattern of spatial summationat these two sites. Overall, this study demonstrates that markedage-related changes in regional taste sensitivity to NaCl arepresent in elderly persons. Chem. Senses 20: 283–290,1995.     

Photomicrobial electrode for selective determination of sulphide

Summary A photomicrobial electrode, which uses the photosynthetic bacteria Chromatium sp. in conjunction with a hydrogen electrode, was developed for the determination of sulphide. The response time of the photomicrobial electrode was 5–10 min. A linear relationship was obtained between the current of the electrode and the sodium sulphide concentration below 3.5 mM. The minimum detectable concentration of sodium sulphide was 0.4 mM. Selectivity of the sensor is satisfactory. A good agreement was obtained between the photomicrobial electrode and the ethylene blue method (correlation coefficient: 0.90).     

Efflux of gamma-aminobutyric acid from and appearance of free arachidonic acid inside synaptosomes

When synaptosomes were depolarized in the presence of Ca2+, or when Ca2+ was added to synaptosomes pretreated with Ca2+ ionophore (A23187), free arachidonic acid was clearly increased within synaptosomes, and at the same time an efflux of gamma-aminobutyric acid from synaptosomes was observed. Moreover, when synaptosomes labelled with [14C]arachidonic acid were depolarized in the presence of Ca2+, there was a significant decrease in the radioactivity of the fatty acid of phosphatidylinositol and phosphatidylcholine. Exogenously added arachidonic acid, but not other fatty acids, stimulated the efflux of gamma-aminobutyric acid in the absence of Ca2+. These observations suggest that the release of arachidonic acid from phospholipids is an intrinsic part of the biochemical mechanism that modulates the gamma-aminobutyric acid efflux.     

Some Properties of the Arginine Decarboxylase in Vicia faba Leaves

Growth of Vicia faba seedlings is accompanied by a rapid increasein arginine decarboxylase (EC 4.1.1.19 [EC] ) in the leaves and epicotyl.Increased enzyme activity was observed under saline conditionsin the presence of NaCl and with osmotic stress by mannitol.The partially purified enzyme (about 86-fold) readily decarboxylatedL-arginine, while D-arginine, L-homoarginine, L-ornithine andL-lysine were decarboxylated very slowly, and L-citrulline andL-glutamic acid were not decarboxylated. The K_m value was 5.8?10^–4M for L-arginine. The optimal pH and temperature for activitywere 8.5 and 45?C, respectively. p-Chloromercuribenzoate andN-ethylmaleimide were effective inhibitors of the enzyme. Inhibitionby spermidine, putrescine and agmatine suggested a possiblefeed-back mechanism in the pathway of polyamine biosynthesis. (Received October 11, 1983; Accepted February 24, 1984)     

Biosynthesis of glycogen in Neurospora crassa. Existence of a glucoproteic intermediate in the initiation process.

A soluble enzyme preparation (20,000 X g supernatant fraction), prepared from the mycelia of wild-type Neurospora crassa, was capable of transferring [14C]glucose from UDP-[14C]glucose into both trichloroacetic acid (TCA)-soluble and TCA-insoluble macromolecule products in the absence of added primer. These reactions did not require either high concentrations of salts or any other chemical reagents. Two labeled products were formed; one was a glycogen-like polysaccharide and the other was a glycoprotein with glucosyl chains bound to protein through an acid-labile bond. After mild treatment of the glucoprotein with acid, the product liberated from the protein behaved as a mixture of malto-oligosaccharides and alpha-1,4-glucan with branches. The carbohydrate moiety of the glucoprotein seemed to be released upon prolonged incubation with the enzyme preparation. The glucan thus liberated from the glucoprotein may serve as a primer for the glycogen synthase. The results obtained are therefore suggestive of the existence of a glucoproteic intermediate in the initiation of glycogen biosynthesis.     

Isolation and some properties of nontoxigenic derivatives of a strain of Clostridium tetani.

Nontoxigenic derivatives of a toxigenic strain of Clostridium tetani were isolated gy treatment with acridine orange, N-methyl-N'-nitro-soguanidine, rifampicin or ultraviolet light. The frequency of appearance fo non-toxigenic derivatives on these treatments was 0.8 to 3.2 per cent. The nontoxigenic derivatives peoduced all the same extracellular antigenic and protein components as the toxigenic parent strain, except the toxin and materials cross-reacting with the toxin. The nontoxigenic strains, like the toxigenic parent strain, were lyzed by trratment with mitomycin C. Bacteriophage was detected in the lysates of all the nontoxigenic derivatives produced with mitomycin C, and this bacteriophage was morphologically indistinguishable from that obtained from the toxigenic parent strain. The genetic factor controlling tetanus toxin production is discussed.