Evaluation of Genetic Diversity of Wild Rice (Oryza rufipogon Griff.) in Myanmar using Simple Sequence Repeats (SSRs)

As a part of an in situ survey of wild rice (Oryza rufipogon Griff.) in Myanmar (Burma), 16 strains of wild rice were collected, and analyzed for allelic diversity over 74 loci with simple sequence repeat (SSR) markers to obtain a basic information for their conservation. Three each of indica and japonica cultivars were added for a comparison. In the six cultivars and 16 strains of wild rice, three to 15 alleles were detected per locus with an average of 7.9. The wild rice revealed a large number of unique alleles throughout their chromosomes with much wider ranges of variation than those detected in the six cultivars of O. sativa L.. The alleles found in the wild rice were classified into those specific to wild rice, common to wild rice and cultivars, and those similar to indica or japonica cultivars. According to the classification, the genotype of each of the 16 strains of wild rice was schematically depicted. The genetic variation among individual strains within a collection site was larger than the variation among the collection sites.     

CTLA-4 control over Foxp3+ regulatory T cell function

Naturally occurring Foxp3+CD4+ regulatory T cells (Tregs) are essential for maintaining immunological self-tolerance and immune homeostasis. Here, we show that a specific deficiency of cytotoxic T lymphocyte antigen 4 (CTLA-4) in Tregs results in spontaneous development of systemic lymphoproliferation, fatal T cell-mediated autoimmune disease, and hyperproduction of immunoglobulin E in mice, and it also produces potent tumor immunity. Treg-specific CTLA-4 deficiency impairs in vivo and in vitro suppressive function of Tregs-in particular, Treg-mediated down-regulation of CD80 and CD86 expression on dendritic cells. Thus, natural Tregs may critically require CTLA-4 to suppress immune responses by affecting the potency of antigen-presenting cells to activate other T cells.     

Endocannabinoid hydrolysis generates brain prostaglandins that promote neuroinflammation

Phospholipase A(2)(PLA(2)) enzymes are considered the primary source of arachidonic acid for cyclooxygenase (COX)-mediated biosynthesis of prostaglandins. Here, we show that a distinct pathway exists in brain, where monoacylglycerol lipase (MAGL) hydrolyzes the endocannabinoid 2-arachidonoylglycerol to generate a major arachidonate precursor pool for neuroinflammatory prostaglandins. MAGL-disrupted animals show neuroprotection in a parkinsonian mouse model. These animals are spared the hemorrhaging caused by COX inhibitors in the gut, where prostaglandins are instead regulated by cytosolic PLA(2). These findings identify MAGL as a distinct metabolic node that couples endocannabinoid to prostaglandin signaling networks in the nervous system and suggest that inhibition of this enzyme may be a new and potentially safer way to suppress the proinflammatory cascades that underlie neurodegenerative disorders.     

Gastric cancer originating from bone marrow-derived cells

Epithelial cancers are believed to originate from transformation of tissue stem cells. However, bone marrow-derived cells (BMDCs), which are frequently recruited to sites of tissue injury and inflammation, might also represent a potential source of malignancy. We show that although acute injury, acute inflammation, or transient parietal cell loss within the stomach do not lead to BMDC recruitment, chronic infection of C57BL/6 mice with Helicobacter, a known carcinogen, induces repopulation of the stomach with BMDCs. Subsequently, these cells progress through metaplasia and dysplasia to intraepithelial cancer. These findings suggest that epithelial cancers can originate from marrow-derived sources and thus have broad implications for the multistep model of cancer progression.     

Studies on haemophilus infection in swine I. Application of the latex agglutination test to the diagnosis of Haemophilus pleuropneumoniae (H. Parahaemolyticus) infection

A latex agglutination test was evaluated as a method for the detection and titration of antibodies against swine Haemophilus infection and it was found that the test is applicable to the etiologic diagnosis of Haemophilus infection in swine. In swine infected experimentally with H. pleuropneumoniae (H. parahaemolyticus), the micromethod of agglutination using latex particles coated with antigens of H. pleuropneumoniae was found to be comparable agar-gel immunodiffusion and complement-fixation tests, which have previously been used for the etiologic diagnosis of the disease. Antibody titers determined by the latex agglutination test corrlated well with those determined by the other serological tests. The latex agglutination test tended to detect antibodies earlier than any of the other tests. By the latex agglutination test, weak cross-reactions were observed among different serotypes of H. pleuropneumoniae, whereas no cross-reaction was demonstrated between H, pleurophneumoniae and H. parasuis. The latex agglutination test was found to be simple and useful for the serological survey of swine Haemophilus infection, especially when dealing with a large number of samples.     

The effect of radiation on the viability and migratory ability of second-stage larvae of Toxocara canis in mice

Larval counts were made on mice 2 days after oral inoculation with X-ray (0-320 Krad) or of gamma ray (0-6 Mrad) irradiated eggs containing second-stage Toxocara canis larvae. The majority of the larvae irradiated with 0-40 Krad were recovered from the liver and lungs, while most of the larvae irradiated with 80 or 160 Krad remained in the digestive tract, mainly in the stomach and the proximal half of the small intestine. Only a small number of the 320 Krad irradiated larvae was recovered from the mice. No significant difference was observed in the viability of irradiated larvae incubated in vitro up to 13 days after irradiation. However, a substantial percentage of the 160 and 320 Krad-irradiated larvae hatched during that period. Very few larvae were recovered from the digestive tract of mice inoculated with eggs irradiated with 0.5 Mrad, and only one and four larvae were recovered from the liver and lungs of a mouse. No visceral larval migration was observed in mice inoculated with 1 Mrad-irradiated eggs. The minimum lethal radiation dose for second-stage T. canis larvae in eggs is proposed to be 1 Mrad.     

Watercore in Japanese pear. III. Changes in the activities of some enzymes relating to the degradation of cell walls and the accumulation of sugar

The relationship between cellular breakdown and the activities of some cell-wall degrading enzymes (endocellulase, exocellulase, polygalacturonase, pectin methylesterase and β-galactosidase) was investigated in the watercored tissue of Japanese pear fruit, Pyrus serotina Rehder var. ‘Culta’ Rehder, cultivar ‘93-3’. In watercored tissue at an early stage, endocellulase activity, especially neutral form, was higher than that in healthy tissue. As the symptom of the watercore developed, polygalacturonase and β-galactosidase activities in the watercored tissue increased compared with those in healthy tissue. This indicated that in tissues at an early stage of watercore, these cell-wall degrading enzymes were activated, and operative in the breakdown of the cell wall. However, exocellulase and pectin methylesterase were not activated in the watercored tissue. The breakdown of cellular tissue was also supported by the fact that the DNA and protein contents decreased in the watercored tissue. Invertase activity decreased in the watercored tissue, compared with healthy tissue, and it was suggested that its decrease could be one of the causes of sucrose accumulation in the watercored tissue.