Changing green leaf volatile biosynthesis in plants: an approach for improving plant resistance against both herbivores and pathogens

Green leaf volatiles (GLVs) are commonly emitted by green plants, and their production is drastically enhanced when they are under biotic stress. To clarify the ecological function of naturally emitted GLVs, we studied the response of Arabidopsis, whose GLV biosynthesis had been modified, when subjected to herbivory or a pathogenic infection. There was a significant increase in GLV production after herbivory by cabbage white butterfly larvae and pathogen (gray mold) infection in hydroperoxide lyase (HPL) sense Arabidopsis compared with WT controls. The HPL sense modification resulted in the plant being more attractive to the parasitic wasp Cotesia glomerata, leading to higher mortality of the herbivores. The HPL sense modification also resulted in greater inhibition of growth of the fungus. By contrast, HPL antisense Arabidopsis produced fewer GLVs, attracted fewer parasitoids, and was more susceptible to the pathogens than the WT control. These data show that (i) one of the ecological functions of GLV biosynthesis related to resistance against both herbivores and pathogens, and (ii) the genetic modification of GLV biosynthesis could be a unique approach for improving plant resistance against such biotic stresses.     

Antibody to hepatitis B core antigen is associated with the development of hepatocellular carcinoma in hepatitis C virus-infected persons: a 12-year prospective study

Several studies have reported that antibody to hepatitis B core antigen (anti-HBc) positivity may influence the development of hepatocellular carcinoma (HCC) in chronic hepatitis C patients, but the evidence is still not conclusive. In this study, we examined whether the presence of anti-HBc positive was associated with the development of HCC in hepatitis C virus (HCV)-infected subjects among the residents in an HCV hyperepidemic area who were followed up for 12 years. In an HCV hyperendemic area (positive rate of anti-HCV: 23.4%), 509 residents were examined by health screening in 1990. After 12 years of follow-up, we evaluated the risk factors for HCC. The incidence of HCC was compared between anti-HBc positive and anti-HBc negative subjects after 12 years of prospective observation. Univariate and multivariate analyses were conducted to determine risk factors for the development of HCC. The incidence of HCC was significantly higher in the anti-HBc positive group (13 subjects) than in the anti-HBc negative group (0 subjects) (P=0.012). Multivariate analysis identified positivity for anti-HBc and HCV RNA, history of icterus, and female gender as independent determinants of the development of HCC. Our findings provide clear evidence in a prospective study that presence of anti-HBc, that is, past hepatitis B virus (HBV) infection, is a risk factor for the development of HCC in HCV-infected people.     

Robust HIV-specific immune responses were induced by DNA vaccine prime followed by attenuated recombinant vaccinia virus (LC16m8 strain) boost

Recombinant vaccinia virus-based vaccine combined with DNA vaccine has produced a protective immune response against HIV infection in non-human primates. In this study, we explored the immunogenicity of a recombinant vaccinia virus (LC16m8 strain), which has been used in children without severe side effects. The vaccinia virus expressing an HIV(89.6)env gene (vLC-Env) alone or combined with a DNA vaccine expressing the HIV(89.6)env gene (pCAG-Env) was characterized in BALB/c mice. Vaccination of vLC-Env induced much higher HIV-specific humoral and cell-mediated immune responses than that of pCAG-Env. Priming with pCAG-Env further enhanced vLC-Env induced immune responses, especially cell-mediated immune response. Moreover, efficient expression of Env protein was achieved following infection of bone marrow dendritic cells by vLC-Env in vitro. Administration of vLC-Env-infected dendritic cells to mice generated a high cell-mediated immune response. These results demonstrate that priming with pCAG-Env and boosting with vLC-Env represents a logical candidate for vaccination against HIV infection.     

Heterogeneity of posterior limbic perfusion in very early Alzheimer's disease

PURPOSE: This study was designed to quantify the heterogeneity of cerebral perfusion on SPECT images in elderly controls and Alzheimer's disease (AD) patients in mild stage using a three-dimensional fractal analysis (3D-FA). MATERIAL AND METHOD: Seventy-five patients with possible and probable AD based on the NINCDS/ADRDA criteria, and thirty-one elderly controls underwent 99mTc-HMPAO SPECT scanning. Dementia severity was assessed using the clinical dementia rating (CDR). Patients with CDR scores of 0.5 (n=33) were classified as "very early" and those with CDR 1 (n=42) as "early". We delineated the SPECT images using 2 cutoffs (35% and 50% cutoffs of the maximal voxel radioactivity) and measured the number of voxels in the areas included by the contours obtained with each cutoff level. The fractal dimension (FD) was calculated by relating the logarithms of cutoff level and the number of voxels. Posterior limbic images were reconstructed at 30 degrees positive to the coronal plane, and posterior limbic FD was calculated. RESULT: Posterior limbic FD for early AD, very early AD, and control groups were 1.03+/-0.16, 1.02+/-0.17, and 0.87+/-0.14 (P=0.001 versus early AD group, P=0.001 versus very early AD). Use of the posterior limbic FD and the ratio of posterior limbic FD to total FD separated very early AD patients from controls with a sensitivity of 76% and a specificity of 81%. CONCLUSION: 3D-FA indicated significant differences in the heterogeneity of CBF distribution between patients with AD in mild stage and elderly controls. Posterior limbic FD may be useful for easily and objectively distinguishing patients with very early AD from aging people.     

Defect of toll-like receptor 9-mediated activation in NC/Nga mouse macrophages

Toll-like receptors (TLRs) control activation of adaptive immune responses by antigen-presenting cells (APCs). In this study, we examined TLR9-mediated activation in NC/Nga mice, an animal model for human atopic dermatitis. NC/Nga mouse macrophages produced significantly less TNF-alpha than did BALB/c mouse macrophages in response to CpG oligonucleotide (ODN). In addition to defective TLR9-mediated TNF-alpha production, phosphorylation of ERK1,2 and p38 was rapidly diminished after 60 min of CpG ODN stimulation, whereas phosphorylation of these molecules was sustained until 60 min in BALB/c mice. Furthermore, phosphorylation of c-Jun N-terminal kinase (JNK) was not observed in NC/Nga mouse macrophages. In contrast, B cells and dendritic cells (DCs) from NC/Nga mice showed normal responses to CpG ODN stimulation. The expression level of TLR9 in NC/Nga mouse macrophages was significantly lower than that in BALB/c mouse macrophages, whereas levels of TLR9 expression in B cells and DCs in NC/Nga mice were the same as those in BALB/c mice. These results suggest that defective TLR9-mediated activation in NC/Nga mouse macrophages contributes to the reduction of TLR9 expression levels.     

Screening for vaginal shedding of cytomegalovirus in healthy pregnant women using real-time PCR: correlation of CMV in the vagina and adverse outcome of pregnancy

The impact of cytomegalovirus (CMV) infection of the genital tract during pregnancy on adverse pregnancy outcomes is not understood fully. A real-time PCR assay was used to determine vaginal shedding of CMV in 993 healthy pregnant Japanese women and the results were compared with the outcome of pregnancy. CMV DNA was detected in 76 (7.7%) of the women. The outcome of pregnancy could be determined finally in 848 women, of whom 60 (7.1%) were CMV positive. The carriers of CMV had an increased miscarriage rate (RR 6.96, 95% CI 2.04-23.84, P < 0.01). These findings suggest that latent genital tract CMV infection predisposes to adverse pregnancy outcomes.     

Hormetic and anti-radiation effects of tropolone-related compounds

We have previously investigated a total of 173 azulene-, tropolone- and azulenequinone-related compounds for their tumor-specificity and anti-inflammatory activity. In this study, we selected six compounds that showed tumor-specific cytotoxicity (referred to as group I compounds) and five compounds that inhibited nitric oxide production by activated macrophages (referred to as group II compounds) to investigate their possible hormetic and anti-radiation effects. We have established three oral normal cell type, human gingival fibroblast HGF-1, pulp cell HPC-1 and periodontal ligament fibroblast HPLF-1, from extracted teeth and periodontal tissue. These normal cells expressed p53 protein, regardless of the growth stage (either at growing or near confluent phase), more than oral squamous cell carcinoma cell line (HSC-2). Group I compounds slightly stimulated the growth of HPL-1 cells only at restricted durations and concentrations, but did not affect that of HGF-1 and HPC-1 cells, suggesting the minor hormetic effects displayed by these compounds. We established a new evaluation system for UV-induced cellular damage using an intact HSC-2 cell system in which sodium ascorbate (vitamin C) and gallic acid, but not N-acetyl-l-cysteine nor catalase, exerted protective effects. Three group I compounds and two group II compounds significantly protected the cells from UV-induced injury, suggesting their possible anti-UV effect.     

Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents --special references to bacteria isolated between April 2008 and March 2009

Bacteria isolated from infections in abdominal surgery during the period from April 2008 to March 2009 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 712 strains including 18 strains of Candida spp. were isolated from 173 (80.5%) of 215 patients with surgical infections. Three hundred and sixty-six strains were isolated from primary infections, and 346 strains were isolated from postoperative infections. From primary infections, anaerobic Gram-negative bacteria were predominant, followed by aerobic Gram-negative bacteria, while from postoperative infections aerobic Gram-positive bacteria were predominant, followed by anaerobic Gram-negative bacteria. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus spp. was highest, followed by Streptococcus spp., and Staphylococcus spp. in this order, from primary infections, while Enterococcus spp. was highest, followed by Staphylococcus spp. from postoperative infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa, in this order, and from postoperative infections, P aeruginosa was most predominantly isolated, followed by E. coli, Enterobacter cloacae, and K. pneumoniae. Among anaerobic Gram-positive bacteria, the isolation rate of Eggerthella lenta was the highest from primary infections, followed by Parvimonas micra, Streptococcus constellatus and Gemella morbillorum, and from postoperative infections, E. lenta was most predominantly isolated. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis was the highest from primary infections, followed by Bacteroides thetaiotaomicron, Bacteroides ovatus and Bilophila wadsworthia, and from postoperative infections, B. fragilis was most predominantly isolated, followed by B. thetaiotaomicron, B. wadsworthia and B. ovatus, in this order. In this series, we noticed no vancomycin-resistant methicillin-resistant S. aureus, and Enterococcus spp., nor multidrug-resistant P aeruginosa. We should carefully follow up B. wadsworthia which was resistant to various antibiotics, and also Bacteroides spp. which was resistant to many beta-lactam antibiotics.