Comparison of the structural characteristics of chromosome VI in Saccharomyces sensu stricto: the divergence, species-dependent features and uniqueness of saké yeasts

Previous studies have revealed that chromosome VI of saké yeasts is much larger than that of the other strains of Saccharomyces cerevisiae. Southern analysis using segments of chromosome VI of a laboratory strain as probes suggested that the nucleotide sequence of a major portion of this chromosome is conserved, but considerable diversity was found in the distal parts in the other strains. Physical maps also indicated that differences in length of chromosome VI were mainly due to differences in its ends. NotI was found to generate 9 kb and/or 16 kb fragments from the left telomere of chromosome VI in most saké yeasts, but no fragment in the case of AB972. SfiI produced one or two 30-50 kb fragments from the right end of this chromosome in all saké yeasts tested, but produced a 20 kb fragment in the case of AB972. All S. cerevisiae strains not employed in saké brewing were the same as AB972 in these respects. S. paradoxus had one NotI site in chromosome VI, while S. bayanus had two, one of which is possibly common to both species. The SfiI site mentioned above was present in chromosome VI of all species, while that of S. bayanus and S. paradoxus each had a second site distinct from the other. Chromosome VI of S. pastorianus was not distinguishable from that of S. bayanus.     

Emergence of a unique O3:K6 clone of Vibrio parahaemolyticus in Calcutta, India, and isolation of strains from the same clonal group from Southeast Asian travelers arriving in Japan

Active surveillance of Vibrio parahaemolyticus infection among hospitalized patients in Calcutta, India, was initiated in January 1994. The incidence of cases of V. parahaemolyticus infection suddenly increased in February 1996 and has remained high since then. One hundred thirty-four strains of V. parahaemolyticus isolated from January 1994 to August 1996 were examined for serovar, the presence of the thermostable direct hemolysin gene (tdh) and tdh-related hemolysin genes (trh1 and trh2), production of urease, and antibiogram. Strains of the O3:K6 serovar appeared for the first time in February 1996. The O3:K6 serovar strains accounted for 50 to 80% of the strains isolated during the high-incidence period (February to August 1996). All of the serovar O3:K6 strains carried the tdh gene but not the trh genes and did not produce urease. All of the isolates except two were sensitive to all of the antibiotics tested. These and the results of analysis by an arbitrarily primed PCR method indicated that the O3:K6 serovar strains belong to a unique clone. When the O3:K6 serovar strains, isolated from travelers arriving in Japan from Southeast Asian countries, were compared by the arbitrarily primed PCR method, the strains isolated between 1982 and 1993 were distinct from Calcutta O3:K6 while the strains isolated in 1995 and 1996 were indistinguishable from the Calcutta O3:K6 strains. The results suggest that this unique O3:K6 clone may have become prevalent not only in Calcutta but also in Southeast Asian countries very recently. Not only the O3:K6 strains but also the non-O3:K6, tdh-bearing strains isolated in 1996 produced thermostable direct hemolysin at high levels, and thus the level of hemolysin produced does not appear to have influenced the high incidence of serovar O3:K6 strains.     

Induction of the 2B9 antigen/dipeptidyl peptidase IV/CD26 on human natural killer cells by IL-2, IL-12 or IL-15

Activation of human natural killer (NK) cells involves sequential events including cytokine production and induction of cell surface molecules, resulting in the enhancement of cytolytic activity. To delineate the activation process of NK cells, we generated murine monoclonal antibodies (mAbs) against YT, a human large granular lymphocyte/natural killer (LGL/NK) cell line. Among the mAbs reactive with YT cells, one mAb, termed 2B9, was noted because of the lack of reactivity with most of the human T- and B-cell lines tested. In fresh peripheral blood mononuclear cells (PBMC), however, the majority of cells expressing this antigen (Ag) were T cells but not CD16+ nor CD56+ NK cells. Since YT cells showed an activated phenotype expressing interleukin-2 (IL-2) receptor alpha chain, we examined whether 2B9 Ag could be induced on normal human peripheral blood NK cells by cytokines known to activate NK cells. The 2B9 Ag was induced on NK cells by IL-2, IL-12 or IL-15 while no induction was observed by interferon-gamma (IFN-gamma). Biochemical analysis showed that anti-2B9 mAb recognized a 115 kDa molecule in YT cells. A cDNA clone encoding the 2B9 Ag was isolated from a cDNA expression library of YT cells and its sequence was identical to CD26 cDNA although it was not of full length. Transient expression of the 2B9 cDNA on COS-7 cells revealed that this cDNA encodes the antigenic epitope(s) recognized by anti-2B9 mAb as well as Ta1, an anti-CD26 mAb. These results showed that the 2B9 Ag is identical to CD26, and demonstrated that CD26 is an activation antigen on CD16+ CD56+ NK cells inducible by IL-2, IL-12 or IL-15.     

Excitatory mechanism of veratridine on slowly adapting pulmonary stretch receptors in anesthetized rabbits

The excitatory effects of veratridine on slowly adapting pulmonary stretch receptors (SARs) were studied before and after administration of ouabain (a Na+-K+ ATPase inhibitor) in anesthetized, artificially ventilated rabbits after vagus nerve section. Administration of veratridine (40 microg/kg) stimulated SAR activity but did not significantly alter tracheal pressure. Administration of ouabain (50 microg/kg) initially stimulated SAR activity during both inflation and deflation, but after 20 min, two different types of SAR responses were observed; one became silent at the peak, of inflation only, and the other maintained excitatory activity during both inflation and deflation phases. Veratridine usually inhibited SAR activity in ouabain-treated animals, irrespective of the difference of ouabain effects. These results suggest that veratridine-induced stimulation of SARs is closely related to the change in the Na+ ion gradient, which is regulated by Na+ pump activity.     

Chemical kindling induced by pentylenetetrazol changes cholecystokinin mRNA and peptide levels in rat frontal cortex

Kindling model is useful to study the mechanism of learning and memory. Cholecystokinin (CCK) mRNA and CCK-like immunoreactivity (CCK-LI) levels in the hippocampus and frontal cortex of chemically kindled rats were determined at different time points. In the frontal cortex, chronic treatment with pentylenetetrazol (PTZ) (40 mg/kg per day for 8 days) increased CCK mRNA level at 7 days, and decreased CCK-LI level at 2 and 7 days after the last injection. However, neither CCK mRNA nor CCK-LI levels in the hippocampus changed. These results suggest that PTZ-induced kindling increases CCK mRNA expression and CCK-LI release in the frontal cortex.     

Postsurgical oral administration of uracil and tegafur inhibits progression of micrometastasis of human breast cancer cells in nude mice

We recently established a metastasis model in nude mice using the MKL-4 cell line, a contransfectant of the MCF-7 human breast cancer cell line with fgf-4 and lacZ in which micrometastases in several organs can be quantitatively observed. First, to develop a new postsurgical metastasis model, we investigated the timing of occurrence of micrometastasis and the influence of tumor removal on the progression of micrometastasis in this model. Micrometastases into lymph nodes and lungs were detected 3 weeks after the cell injections. Tumor removal 3 weeks after the injections significantly enhanced the progression of micrometastasis into lymph nodes and bone. Second, to study the effect of a mixed compound, UFT (a molar ratio of uracil:tegafur of 4:1), which has been widely used in the postsurgical adjuvant setting in Japan, 15 or 20 mg/kg UFT were administered p.o. for 4 weeks to tumor-bearing mice or to mice in which transplanted tumors were resected 3 weeks after the injections. Either dose of UFT significantly inhibited the tumor growth as well as the progression of micrometastasis into lymph nodes, lungs, liver, and brain. In addition, enhanced progression of micrometastasis in all explored organs by the tumor removal was significantly inhibited by the administration of either dose of UFT. In conclusion, this new postsurgical metastasis model may be useful for evaluating the efficacy of agents used in the postoperative adjuvant setting. UFT may be an effective drug for inhibiting the progression of micrometastasis after surgery.     

Monitoring system for the totally implantable ventricular assist system by use of sensors for virtual reality

The aim of this study was to compare the clinical efficacy and safety of low dose cyproterone acetate-estrogen combination (Diane) and the 5 alpha-reductase inhibitor finasteride in the treatment of hirsutism. Fourty-two women with hirsutism were included in the study. Twenty-one patients treated with cyproterone acetate (CPA) 2 mg and ethinyl estradiol (E) 35 micrograms daily on days 5-25 of the menstrual cycle, 21 with finasteride 5 mg daily. Hirsutism score, hormone levels, multiscreen blood chemistry and side effects were evaluated at three-monthly intervals for 9 months. A significant decrease in hirsutism score as compared to baseline was observed after 9 months with either CPA + E (Diane) (mean +/- SE, 15.81 +/- 1.19 vs 8.38 +/- 1.21) or finasteride treatment (17.81 +/- 1.05 vs 10.86 +/- 0.91) (p < 0.0005). The reductions in hirsutism scores (mean% +/- SE) were 14.23 +/- 2.29 vs 19.77 +/- 2.22 (p < 0.05) at 3, 40.23 +/- 4.58 vs 29.49 +/- 2.69 (p < 0.02) at 6 and 50.99 +/- 4.13 vs 39.87 +/- 3.30 (p < 0.02) at 9 months in CPA + E and finasteride groups, respectively. No significant changes were observed in hormone levels during finasteride treatment. Serum free testosterone significantly decreased at the third month of treatment, and remained suppressed for the duration of treatment in CPA + E group. DHEAS levels also decreased significantly after 6 and 9 months of therapy with CPA + E. SHBG significantly increased during CPA + E treatment. We conclude that both drugs are effective and well tolerated, but CPA + E appears to be more effective than 5 alpha-reductase inhibitor finasteride in long-term treatment of hirsute women. Diane is also a cost-effective drug.     

Role of nitric oxide in pathogenesis of gastric mucosal damage induced by compound 48/80 in rats

We examined the effects of various nitric oxide synthase (NOS) inhibitors on development of gastric lesions induced by compound 48/80 (48/80) in rats and investigated the roles of NO and inducible NOS (iNOS) in inflammatory gastric responses. Animals were given 48/80 (1 mg/kg, i.p.) once daily for 4 days, and the stomachs were examined for lesions 24 h after the final administration. NOS inhibitors such as L-NAME, L-NMMA, aminoguanidine or dexamethasone were administered for 4 days during 48/80 treatment. The repeated administration of 48/80 caused damage in the stomach with severe edema in the submucosa. These lesions induced by 48/80 were dose-dependently prevented by concurrent administration of L-NAME. The protective effect of L-NAME on 48/80-induced gastric lesions was mimicked by L-NMMA, aminoguanidine as well as dexamethasone, and significantly antagonized by co-administration of L-arginine but not by D-arginine. Acid secretion was slightly decreased after 48/80 treatment, but was significantly augmented by the combined administration of L-NAME with 48/80. The mucosal MPO activity, TBA reactants and vascular permeability in the stomach were all increased after 48/80 treatment, but these changes were also significantly mitigated by co-administration of L-NAME. The Ca(2+)-independent NOS activity in the mucosa was increased four times during 48/80 treatment, and this change was also inhibited by dexamethasone. These results suggest that: 1) the repeated administration of 48/80 induced inflammatory gastric lesions in the rat stomach; 2) the pathogenic mechanism of these lesions involves endogenous NO produced by iNOS, in addition to oxyradical formation; and 3) the deleterious role of NO during 48/80 treatment may be accounted for by a cytotoxic action of peroxynitrite, which is formed in the presence of NO and superoxide radicals.     

A cross-validation of the European Organization for Research and Treatment of Cancer QLQ-C30 (EORTC QLQ-C30) for Japanese with lung cancer

The EORTC QLQ-C30 was developed in English-speaking cultures. To determine if this instrument could cross a broad cultural divide and be used in Japan, the cross-cultural validity of its Japanese version was estimated. In evaluating psychometric testing, internal consistency by Cronbach's alpha, item-discrimination by multitrait scaling analysis, and validity analysis with ECOG performance score (PS) and Karnofsky Performance Status Scale (KPS) were performed. The QLQ-C30 (version 1.0) was given to 105 patients with lung cancer. Although the response rate was low in patients with PS 4, the questionnaire was well accepted by patients with PS 0-3. The Japanese QLQ-C30 has a weak scale of role functioning in terms of item discriminative validity. It also has a weak scale of cognitive functioning in items of discriminative validity and internal consistency. However, known-groups comparison showed the expected clinical validity with PS for all the scales except for financial impact, and longitudinally clinical validity with KPS was shown in scales of cognitive functioning, fatigue, and nausea and vomiting. Multitrait scaling analysis showed that the predicted scales constituting quality of life (QOL) in the English-speaking culture were extracted from the Japanese QLQ-C30, and found to be valid in Japan, indicating its possible usefulness as an instrument that is universally applicable across cultures.     

Mutational analysis of the N-ras gene in acute lymphoblastic leukemia: a study of 125 Japanese pediatric cases

Many antibiotic resistance mutations arise in pathogenic bacteria that harbor plasmids (R-plasmids). Resistance to third generation cephalosporins, for instance, largely occurs by one or more point mutations in plasmid bla genes that expand the resistance spectrum of beta-lactamases. Here I review relevant evidence underlying the worldwide emergence of extended spectrum beta-lactamases (ESBLs). The conclusion reached is that the origin of these resistance-conferring mutations cannot be explained by a series of single point mutation and selection events. Instead, highly advantageous stochastic processes might exist that generate alterations in the sequence or the conformation of particular regions in chromosomal or plasmid genomes such as bla, i.e., recombination or mutation. Several explanations for the origin of ESBLs are reviewed but direct experimental evidence to support or to invalidate them is still lacking. The cellular conditions under which ESBLs arise are unknown; however, involvement of nutritional stresses inside natural animal hosts and of plasmid conjugal functions appear likely.