Diversity and Distribution of Rice Blast (Pyricularia oryzae Cavara) Races in Bangladesh.

The pathogenicity of 331 blast isolates (Pyricularia oryzae Cavara) collected from different regions and ecosystems for rice cultivation in Bangladesh was evaluated by compatibility on 23 differential varieties (DV), each harboring a single blast resistance gene, and susceptible 'Lijiangxintuanheigu' (LTH). A wide variation in virulence was found among the isolates, and 267 races were classified using a new designation system. Virulence of blast isolates against DV carrying the resistance genes Pia, Pib, Pit, Pik-s, Piz-t, Pi12(t), Pi19(t), and Pi20(t), as well as avirulence against those carrying Pish, Pi9, Pita-2, and Pita, was distributed widely in Bangladesh. Cluster analysis of the compatibility data on the DV initially classified the isolates into groups I and II. The virulence spectra of the two groups differed mainly according to the reactions of the DV to Pii, Pi3, Pi5(t), Pik-m, Pi1, Pik-h, Pik, Pik-p, and Pi7(t). Group I isolates were distributed mainly in rainfed lowlands, whereas group II isolates were found mainly in irrigated lowlands; however, there were no critical differences in geographic distribution of the blast isolates. In total, 26 isolates, which could be used to identify the 23 resistance genes of the DV on the basis of their reaction patterns, were selected as a set of standard differential blast isolates. To our knowledge, this is the first clear demonstration of the diversity and differentiation of blast races in Bangladesh. This information will be used to develop a durable blast protection system in that country.

Diversity and Distribution of Rice Blast (Pyricularia oryzae Cavara) Races in Japan.

In total, 310 rice blast (Pyricularia oryzae Cavara) isolates from Japan showed wide variation in virulence. Virulence on rice (Oryza sativa L.) differential varieties (DV) harboring resistance genes Pish, Pia, Pii, Pi3, Pi5(t), Pik-s, and Pi19(t) ranged from 82.9 to 100.0%. In contrast, virulence on DV possessing Pib, Pit, Pik-m, Pi1, Pik-h, Pik, Pik-p, Pi7(t), Pi9(t), Piz, Piz-5, Piz-t, Pita-2, Pita, Pi12(t), and Pi20(t) ranged from 0 to 21.6%. Cluster analysis using the reaction patterns of the DV classified isolates into three groups: I, virulent to Pik, Pik-h, Pik-p, Pik-m, Pi1, and Pi7(t); IIa, avirulent to the preceding 6 genes and virulent to Pia, Pii, Pi3, and Pi5(t); and IIb, avirulent to all 10 genes. Group I was limited to northern Japan and group IIb to central Japan, while group IIa was distributed throughout Japan. We estimate that group IIa represents the original population and that groups I and IIb arose from it through minor changes in pathogenicity. We classified these isolates into 123 races by a new designation system and conclude that the rice blast races in Japan are less diverse than previously thought.

Partial response of angiosarcoma of the scalp to sorafenib: association with decreased expression of vascular endothelial growth factors and their receptors.

The prognosis of angiosarcoma remains very poor, even with combined, multimodal therapy. We report a case with partial response of angiosarcoma of the scalp to sorafenib, which is a new oral, molecular, targeted, multiple-kinase inhibitor. In addition, we confirmed, using immunohistochemistry, that sorafenib suppressed the expression of vascular endothelial growth factors and their receptors on the angiosarcoma tumour cells, and decreased cell numbers by inhibiting cellular proliferation.

D1-receptor dependent synaptic potentiation in the basal ganglia of quail chicks.

Properties of local synapses were analyzed in lobus parolfactorius (LPO; avian homologue of caudate-nucleus) of quail chicks by using slice preparations in vitro. Field-potential extracellular and whole-cell intracellular recordings revealed excitatory synaptic inputs converging from dorsal and ventral regions within LPO. With exogenous dopamine (100 microM) in the perfusate, synchronized conditioning stimulation induced biased changes in the dorsal and the ventral inputs; potentiation in the dorsal input and depression in the ventral input in average. On the other hand, de-synchronized conditioning failed to induce such biased changes, although the differences were not statistically significant. SCH-23390 (3 microM) blocked the dorsal potentiation, while AP-5 (100 microM) tended to block both of these changes. The plastic nature may underlie the memory formation in appetitive/aversive learning tasks.

The role of basal ganglia in reinforcement learning and imprinting in domestic chicks.

Effects of bilateral kainate lesions of telencephalic basal ganglia (lobus parolfactorius, LPO) were examined in domestic chicks. In the imprinting paradigm, where chicks learned to selectively approach a moving object without any explicitly associated reward, both the pre- and post-training lesions were without effects. On the other hand, in the water-reinforced pecking task, pre-training lesions of LPO severely impaired immediate reinforcement as well as formation of the association memory. However, post-training LPO lesions did not cause amnesia, and chicks selectively pecked at the reinforced color. The LPO could thus be involved specifically in the evaluation of present rewards and the instantaneous reinforcement of pecking, but not in the execution of selective behavior based on a memorized color cue.

Reward-related neuronal activities in basal ganglia of domestic chicks.

We aimed to reveal what is coded in the basal ganglia of domestic chicks. In the water-reinforced 'go' task, chicks learned to peck selectively at a colored bead in order to obtain a drop of water. Out of 38 units obtained, seven showed excitatory activities specifically during the reward period. In the food-reinforced go/no-go task, chicks learned to discriminate two colors to obtain mash food after a delay period. They also learned to ignore another color, which was not associated with a reward. Out of 27 units obtained, four showed excitatory activities during the cue period, specifically when a food reward was anticipated. LPO neurons may code qualities of the obtained rewards, and also chick's anticipation of the forthcoming rewards.

Effect of fatty acids on phase behavior of hydrated dipalmitoylphosphatidylcholine bilayer: saturated versus unsaturated fatty acids.

The effect of some fatty acids on the phase behavior of hydrated dipalmitoylphosphatidylcholine (DPPC) bilayer was investigated with special interest in possible difference between saturated and unsaturated fatty acids. The phase behavior of hydrated DPPC bilayer was followed by a differential scanning calorimetry and a Fourier transform infrared spectroscopy. The addition of palmitic acid (PA) increased the bilayer phase transition temperature with the increase of the PA content in the mixture. In addition, DPPC molecules in gel phase bilayer became more rigid in the presence of PA compared with those in the absence of PA. This effect of PA on the phase behavior of hydrated DPPC bilayer is common to other saturated fatty acids, stearic acid, myristic acid, and also to unsaturated fatty acid with trans double bond, elaidic acid. Contrary to these fatty acids, oleic acid (OA), the unsaturated fatty acid with cis double bond in the acyl chain, exhibited quite different behavior. The effect of OA on the bilayer phase transition temperature was rather small, although a slight decrease in the temperature was appreciable. Furthermore, the IR spectral results demonstrated that the perturbing effect of OA on the gel phase bilayer of DPPC was quite small. These results mean that OA does not disturb the hydrated DPPC bilayer significantly.

Predisposed visual memory of shapes in quail chicks.

Newly hatched chicks will spontaneously peck at conspicuous objects in their field of view, and soon learn to distinguish between edible food particles and unpleasant tasting objects. To examine whether the selective pecking is based on the ability to memorize shapes, we analyzed pecking behavior of 1- to 2-days-old quail chicks (Coturnix japonica) by using ball- and triangle-shaped beads both painted in green. Repeated presentation of dry bead (either ball or triangle) resulted in a progressively fewer number of pecks (habituation). When chicks were tested by triangle after repeated presentation of ball, chicks showed a significant increase in the number of pecks at the triangle (dishabituation). On the other hand, when tested by ball after a series of triangle presentations, pecking frequency did not increase (no dishabituation). Chicks thus distinguished the triangle as a novel object after being habituated to ball, but did not respond to the ball after triangle. A similar asymmetry was found in one-trial passive avoidance task. Chicks were pre-trained by water-coated (neutral) triangle and then trained by methylanthranilate-coated (aversive) ball. In this case, most chicks learned to avoid the ball, and half of these successful learners pecked at the triangle; they distinguished triangle from ball. When chicks were pre-trained by neutral ball and trained by aversive triangle, on the other hand, most chicks did not distinguish the ball from triangle, and showed a generalized avoidance for both beads. Chicks may be innately predisposed to memorize a limited category of shapes such as ball, and associate them with selective avoidance.

Accurate visual memory of colors in controlling the pecking behavior of quail chicks.

Animals are predisposed to memorize specific features of objects they encounter, and to link them with behavioral outputs in a selective manner. In this study, we examined whether chicks memorize objects by colors, and how they exploit the memorized color cues for selective pecking in 1- to 2-days-old quail chicks (Coturnix japonica). Ball-shaped beads painted in green (G), yellowish green (YG) and the intermediate color (YGG) were used. Repetitive presentation of a bead (interval: 4.5 min) resulted in gradually fewer pecks (habituation). Subsequent presentation of a different color caused proportionately more pecks (dishabituation); e.g., after habituation to the G bead, the YG bead caused a stronger dishabituation than the YGG bead did. The dishabituation appeared symmetric; e.g., the YG bead caused as strong dishabituation after the G-habituation, as was caused by the G bead after the YG-habituation. Number of pecks could thus reveal the memory-based color perception in chicks. Similar discrimination of beads by memorized color cues was found after one-trial passive avoidance training, where chicks learned to avoid a bitter-tasting object without any differential pre-training experiences. However, proportion of the chicks that discriminated between different colors became progressively smaller at test 15 min, 1 hr, and 24 hr post-training. On the other hand, proportion of chicks that distinguished beads by non-color cues remained unchanged. Chicks may primarily form an accurate memory of colors, but gradually change the link between the color memory and the pecking behavior.

Structure and transcriptional control of the flagellar master operon of Salmonella typhimurium.

The flhD and flhC genes constitute the flagellar master operon whose products are required for expression of all the remaining flagellar operons in Salmonella typhimurium. Here we report the molecular structure and in vivo and in vitro expression of the flhD operon. Nucleotide sequence analysis revealed that the upstream region of this operon contains the consensus sequence for the cAMP-CRP binding site. Primer extension analysis demonstrated six possible transcription start sites for this operon. They include CRP-dependent and CRP-repressible transcription start sites. The CRP-dependent transcription start site is located 203 bp upstream of the initiation codon of the flhD gene and preceded by the consensus sequences of the -10 and -35 regions of the sigma 70-dependent promoter. The putative cAMP-CRP binding site is located centered 70 bp upstream of this start site. The CRP-repressible transcription start site is located within this putative cAMP-CRP binding site. These two start sites were confirmed by in vitro transcription experiments using sigma 70-RNA polymerase with or without cAMP-CRP.

EBI1/CCR7 is a new member of dendritic cell chemokine receptor that is up-regulated upon maturation.

Dendritic cells (DC) that are stimulated with inflammatory mediators can maturate and migrate from nonlymphoid tissues to lymphoid organs to initiate T cell-mediated immune responses. This migratory step is closely related to the maturation of the DC. In an attempt to identify chemokine receptors that might influence migration and are selectively expressed in mature DC, we have discovered that the chemokine receptor, EBI1/CCR7, is strikingly up-regulated upon maturation in three distinct culture systems: 1) mouse bone marrow-derived DC, 2) mouse epidermal Langerhans cells, and 3) human monocyte-derived DC. The EBI1/CCR7 expressed in mature DC is functional because ELC/MIP-3beta, recently identified as a ligand of EBI1/CCR7, induces a rise in intracellular free calcium concentrations and directional migration of human monocyte-derived mature DC (HLA-DRhigh, CD1a(low), CD14-, CD25+, CD83+, and CD86high) in a dose-dependent manner, but not of immature DC (HLA-DRlow, CD1a(high), CD14-, CD25-, CD83-, and CD86-). In contrast, macrophage inflammatory protein-1alpha (MIP-1alpha), monocyte chemotactic protein-3 (MCP-3), and RANTES are active on immature DC but not on mature DC. Thus, it seems likely that MIP-1alpha, MCP-3, and RANTES can mediate the migration of immature DC located in peripheral sites, whereas ELC/MIP-3beta can direct the migration of Ag-carrying DC from peripheral inflammatory sites, where DC are stimulated to up-regulate the expression of EBI1/CCR7, to lymphoid organs. It is postulated that different chemokines and chemokine receptors are involved in DC migration in vivo, depending on the maturation state of DC.

Distinct mechanisms for expression of Fos-like immunoreactivity and synaptic potentiation in telencephalic hyperstriatum of the quail chick.

In the intermediate and medial hyperstriatum ventrale (IMHV), a telencephalic region essentially involved in the initial processes of early learning tasks in poultry chicks, induction of an immediate early gene c-fos correlates significantly with the degree of learning (K.V. Anokhin, R. Mileusnic, I.Y. Shamakina, S.P.R. Rose, Effects of early experience on c-fos gene expression in the chick forebrain, Brain Res. 544 (1991) 101-107; B.J. McCabe, G. Horn, Learning-related changes in Fos-like immunoreactivity in the chick forebrain after imprinting, Proc. Natl. Acad. Sci. USA 91 (1994) 11417-11421). In slices of IMHV in vitro, on the other hand, tetanic stimulation at a low frequency induces a potentiation of synaptic responses (P.M. Bradley, B.D. Burns, A.C. Webb, Potentiation of synaptic responses in slices from the chick forebrain, Proc. R. Soc. Lond. B. 243 (1991) 19-24; T. Matsushima, K. Aoki, Potentiation and depotentiation of DNQX-sensitive fast excitatory synaptic transmission in telencephalon of the quail chick, Neurosci. Lett. 185 (1995) 179-182). In this study, we have examined a possible causal link between these two forms of activity-dependent processes, c-fos expression and synaptic potentiation. C-fos was visualized immunohistochemically using antibody raised against the Fos-protein, and potentiation was evaluated on the basis of field potential responses to local electrical stimulation. Tetanic stimulation (5 Hz x 300 pulses) was required for potentiation, but not for c-fos expression. Conversely, a negative correlation appeared between them, and slices with relatively high density of Fos-like immunoreactive cells around the stimulation site failed to show potentiation. Furthermore, drugs similarly effective in blocking potentiation (such as AP5 (NMDA receptor antagonist) and bicuculline (GABA(A) receptor antagonist)) had different effects on the c-fos induction. While AP5 had minor, if any, effects on c-fos expression, bicuculline enhanced it selectively around the site of stimulation. Our results suggest that these two processes are basically distinct, and could represent different aspects in the formation of memory traces in IMHV.

Molecular analysis of the inheritance of the S-5 locus, conferring wide compatibility in Indica/Japonica hybrids of rice (O. sativa L.).

RFLP analysis was conducted on a population derived from a three-way cross to determine the location of the hybrid sterility locus, S-5, in relation to mapped molecular markers and to identify markers that would be useful for selection in breeding. S-5 is of interest to rice breeders because it is associated with spikelet sterility of F1 hybrids in Indica/Japonica crosses. Identification of an S-5 allele which confers fertility in Indica/Japonica hybrids when introgressed into either the Indica or the Japonica parent has been reported. Varieties carrying this S-5 (n) allele are known as "wide compatibility varieties (WCV)". Our data suggests that RFLP marker RG213 on chromosome 6 is closely linked to the S-5 locus and can be efficiently used to identify wide compatibility (WC) lines. RG213 is a single-copy genomic clone that detects three bands of different molecular weights in DNA from Japonica ('Akihikari') and Indica ('IR36') varieties and WC line ('Nekken 2'). We demonstrate that the three alleles detected by this marker could be used to trace the inheritance of the "wide compatible" phenotype in breeders' material.

Cloning of the mouse cDNA encoding DNA topoisomerase I and chromosomal location of the gene.

The mouse cDNA encoding DNA topoisomerase I (TopoI) was cloned and the nucleotide sequence of 3512 bp was determined. The cDNA clone contained an open reading frame encoding a protein of 767 amino acids (aa), which is 2 aa longer than its human counterpart. Overall aa sequence homology between the mouse and human, and between the mouse and yeast (Saccharomyces cerevisiae) sequences was 96% and 42%, respectively. The mouse TopI gene was mapped at position 54.5 on chromosome 2 from linkage analyses of a three-point cross test with Geg, Ada, and a as marker genes.

Segregation distortion via male gametes in hybrids between Indica and Japonica or wide-compatibility varieties of rice (Oryza sativa L).

One or two marker genes on each of chromosomes 3, 4, 6, 7, 8, 11 and 12 of the 12 rice chromosomes were tested for segregation distortion in indica-japonica hybrids. Marker genes on chromosomes 3, 7, 8, 11 and 12 showed clear segregation distortion. This distortion was not related to the proportion of normal pollen. The germinability of the pollen was less than 10% in the hybrids, although 45-55% of the pollen grains appeared to be morphologically normal. The frequent occurrence of segregation distortion and the low germinability of the pollen grains suggested that a large portion of the pollen produced by the Indica-Japonica hybrids was not functional. The fact that the segregation distortion of the same marker may be positive or negative depending on the cross combination suggested the existence of multiple alleles, including distortion-neutral alleles. The latter mitigate pollen sterility in certain hybrid combinations.

Exacerbation of indomethacin-induced gastric ulceration by systemically administered GABA in rats: possible involvement of peripheral GABA receptors.

Effects of systemically administered gamma-aminobutyric acid (GABA) on indomethacin-induced gastric ulceration were studied in rats. Orally administered GABA significantly exacerbated the ulceration in a dose-dependent manner, although GABA per se had no ulcerogenic activity. The exacerbation was restored by GABA receptor antagonists, bicuculline methiodide, picrotoxin and pentylenetetrazol. Pretreatment with atropine sulfate antagonized the exacerbating effect of GABA on indomethacin-induced ulceration. 3-Amino-1-propanesulfonic acid, but not glycine, taurine or beta-alanine, mimicked the effect of GABA on the ulceration, which was inhibited by picrotoxin. Muscimol and (-)-baclofen could not potentiate the ulceration. However, sodium pentobarbital and diazepam caused synergistic exacerbation of the ulcer when combined with GABA. Since it is known that systemically administered GABA can not penetrate into the brain, these results suggest that systemically administered GABA may stimulate the cholinergic transmission mediating the activation of peripheral GABA receptors, resulting in the exacerbation of indomethacin-induced ulceration.

[Improved high performance liquid chromatography determination of hippuric acid and methylhippuric acid isomers in urine].

A study was made on the effect of detection wavelength and separation mode of HPLC on determination of urinary hippuric acid (HA) and three isomers of methylhippuric acid (MHA). The interference of other constituents of urine in the determination was effectively decreased by detection at a short wavelength of 227.6 nm. Meta and para MHAs were separated by the addition of beta-cyclodextrine to the mobile phase. Four metabolites were successfully separated from other components of urine by the combination of ODS-silica packed-column and mobile phase (method F). The detection limits were found to be 50 and 5 mg/l for HA and MHAs, respectively. MHAs could not be detected in the non-exposed subjects. Average levels (+/- SD) of HA in non-exposed males and females were 272.2 (+/- 210.8) and 393.0 (+/- 269.8) mg/l, respectively. The urinary levels of HA in females were significantly higher than those in males.

Comparison of the effects of urinary flow on adjusted and non-adjusted excretion of heavy metals and organic substances in 'healthy' men.

The effect of variation in urinary flow rate (ml urine min-1, UF) on adjusted and non-adjusted urinary excretion of metals and organic substances was examined in ten 'healthy' men. The effect of UF was found to be eliminated when urinary concentrations of lead (Pb), hippuric acid (HA), delta-aminolevulinic acid (ALA) and coproporphyrin (CP) were adjusted to urinary specific gravity and to UF. Similarly, the effect of UF on inorganic mercury (Hg) was eliminated when the concentration was adjusted to timed excretion and to UF. The effect on zinc (Zn) and copper (Cu) was eliminated when adjusted to urinary creatinine (Cn) and to UF. The difference in the effect of UF on the adjusted urinary excretion was explained by the effect of UF on timed excretion of substance, which was ranked in the following order: Pb, HA, total urinary solutes, ALA and CP; Zn; Cu; Cn; and Hg. It was concluded that 'UF-adjusted concentration' is applicable to measurement of all substances in urine as a method of minimizing UF effects, while the other three adjustment methods have only limited uses.

Accumulation of germanium in the tissues of a long-term user of germanium preparation died of acute renal failure.

Acute renal failure developed in a patient accompanied by systemic manifestations such as myopathy and skin rash. The patient, a middle aged house wife, had been taking 600 mg of germanium (Ge) preparation daily for 18 months as an elixir. The main component of the preparation was GeO2 and some organic compound was also present. Histological study of the kidney post mortem showed foamy cell transformation of glomerular epithelia, degeneration of tubular epithelia with red blood cell casts and urate crystals, and a mild proliferation of mesangial matrix. Analysis of the tissue content of Ge, prompted by her history, revealed an increased accumulation of the metal. As compared to a non-user died of liver cirrhosis, the concentration of the metal was higher particularly in the spleen (183X), thyroid gland (175X), psoas muscle (93X), jejunum (76X), and renal cortex (69X). So far, neither accumulation of Ge in humal tissue nor systemic toxicity of the Ge in human has been reported. The relevance of massive accumulation of Ge to the renal failure as well as to other systemic manifestations the patient presented remains to be clarified.