Superoxide radical- and peroxynitrite-scavenging activity of anthocyanins; structure-activity relationship and their synergism

Antioxidant activities of 15 purified bilberry anthocyanins together with pelargonidin 3-O-beta-D-glucopyranoside and 4'-O-methyl delphinidin 3-O-beta-D-glucopyranoside (MDp 3-glc), the major metabolite of delphinidin 3-O-beta-D-glucopyranoside (Dp 3-glc), were evaluated in order to study the structure-antioxidant activity relationship and any synergism among them in the mixture. Both aglycone structure and the attached sugar moiety affected the O*2- and ONOO- -scavenging activities, although the effect of the attached sugar moiety was smaller than that of the aglycone structure. The potency of activity toward the superoxide radical was in the following order: delphinidin > petunidin > malvidin =approximately cyanidin>(+)-catechin > peonidin > pelargonidin. The activity toward ONOO- was: delphinidin > cyanidin =approximately petunidin > malvidin =approximately (+)-catechin > peonidin > pelargonidin. It was confirmed that methylation of 4'-OH markedly reduced the antioxidant activity of anthocyanin. Further, it was revealed that synergism occurred in both - and ONOO- -scavenging activities among the anthocyanins in the mixture.     

A new class of pentapeptide KISS1 receptor agonists with hypothalamic–pituitary–gonadal axis activation

The kisspeptin (Kp, Kp-54, metastin)/KISS1R system plays crucial roles in regulating the secretion of gonadotropin-releasing hormone. Continuous administration of nonapeptide Kp analogs caused plasma testosterone depletion, whereas bolus administration caused strong plasma testosterone elevation in male rats. To develop a new class of small peptide drugs, we focused on stepwise N-terminal truncation of Kp analogs and discovered potent pentapeptide analogs. Benzoyl-Phe-azaGly-Leu-Arg(Me)-Trp-NH₂ (16) exhibited high agonist activity for KISS1R and excellent metabolic stability in rat serum. A single injection of a 4-pyridyl analog (19) at the N-terminus of 16 into male Sprague Dawley rats caused a robust increase in plasma luteinizing hormone levels, but unlike continuous administration of nonapeptide Kp analogs, continuous administration of 19 maintained moderate testosterone levels in rats. These results indicated that small peptide drugs can be successfully developed for treating sex hormone deficiency.     

Polygonum sachalinense alters the balance between capacities of regeneration and carboxylation of ribulose‐1,5‐bisphosphate in response to growth CO2 increment but not the nitrogen allocation within the photosynthetic apparatus

The limiting step of photosynthesis changes depending on CO₂ concentration and, in theory, photosynthetic nitrogen use efficiency at a respective CO₂ concentration is maximized if nitrogen is redistributed from non‐limiting to limiting processes. It has been shown that some plants increase the capacity of ribulose‐1,5‐bisphoshate (RuBP) regeneration (evaluated as J_max) relative to the RuBP carboxylation capacity (evaluated as V_cmax) at elevated CO₂, which is in accord with the theory. However, there is no study that tests whether this change is accompanied by redistribution of nitrogen in the photosynthetic apparatus. We raised a perennial plant, Polygonum sachalinense, at two nutrient availabilities under two CO₂ concentrations. The J_max to V_cmax ratio significantly changed with CO₂ increment but the nitrogen allocation among the photosynthetic apparatus did not respond to growth CO₂. Enzymes involved in RuBP regeneration might be more activated at elevated CO₂, leading to the higher J_max to V_cmax ratio. Our result suggests that nitrogen partitioning is not responsive to elevated CO₂ even in species that alters the balance between RuBP regeneration and carboxylation. Nitrogen partitioning seems to be conservative against changes in growth CO₂ concentration.     

An alteration in the lateral geniculate nucleus of experimental glaucoma monkeys: in vivo positron emission tomography imaging of glial activation

We examined lateral geniculate nucleus (LGN) degeneration as an indicator for possible diagnosis of glaucoma in experimental glaucoma monkeys using positron emission tomography (PET). Chronic intraocular pressure (IOP) elevation was induced by laser trabeculoplasty in the left eyes of 5 cynomolgus monkeys. Glial cell activation was detected by PET imaging with [(11)C]PK11195, a PET ligand for peripheral-type benzodiazepine receptor (PBR), before and at 4 weeks after laser treatment (moderate glaucoma stage). At mild, moderate, and advanced experimental glaucoma stages (classified by histological changes based on the extent of axonal loss), brains were stained with cresyl violet, or antibodies against PBR, Iba-1 (a microglial marker), and GFAP (an activated astrocyte marker). In laser-treated eyes, IOP was persistently elevated throughout all observation periods. PET imaging showed increased [(11)C]PK11195 binding potential in the bilateral LGN at 4 weeks after laser treatment; the increase in the ipsilateral LGN was statistically significant (P<0.05, n = 4). Immunostaining showed bilateral activations of microglia and astrocytes in LGN layers receiving input from the laser-treated eye. PBR-positive cells were observed in LGN layers receiving input from laser-treated eye at all experimental glaucoma stages including the mild glaucoma stage and their localization coincided with Iba-1 positive microglia and GFAP-positive astrocytes. These data suggest that glial activation occurs in the LGN at a mild glaucoma stage, and that the LGN degeneration could be detected by a PET imaging with [(11)C]PK11195 during the moderate experimental glaucoma stage after unilateral ocular hypertension. Therefore, activated glial markers such as PBR in the LGN may be useful in noninvasive molecular imaging for diagnosis of glaucoma.     

Determining an effective sampling method for eDNA metabarcoding: a case study for fish biodiversity monitoring in a small,natural river

Limnology - In recent years, biodiversity loss has become one of the most serious environmental issues worldwide, especially in aquatic ecosystems. To avoid diversity loss, it is necessary to...     

Immune gene therapy of experimental mouse brain tumor with adenovirus-mediated gene transfer of murine interleukin-4

 We examined the antitumor activity of replication-deficient adenoviral vectors carrying the murine interleukin-4 (IL-4) gene (AdCIL4) using a syngeneic brain tumor model in mice. Mice implanted with malignant astrocytoma cells infected with AdCIL4 survived significantly longer than those in the control groups. Immunocytochemical analysis of the tumors showed that AdCIL4 caused the strong up-regulation of MHC class II antigen expression by the tumor cells and macrophages, and consequent infiltration by CD8⁺ T lymphocytes. This study demonstrates the efficacy of IL-4 gene transfection mediated by adenoviral vectors for intracerebral tumor and characterizes the immunoreaction caused by AdCIL4. Received: 27 August 1999 / Accepted: 12 November 1999     

Promoters of Rice Seed Storage Protein Genes Direct Endosperm-Specific Gene Expression in Transgenic Rice

The promoters of genes encoding rice seed storage proteins (glutelin,prolamin, globulin and albumin) were analyzed for their abilityto direct rß-gIucuronidase (GUS) gene expression intransgenic rice plants. All promoters tested could direct endosperm-specificexpression of the GUS reporter gene irrespective of variableactivities and patterns in the endosperm. (Received February 27, 1998; Accepted May 16, 1998)