Changes in quality of Phellinus gilvus mushroom by different drying methods

This study was conducted to investigate the changes in characteristics of the Phellinus gilvus mushroom as influenced by drying methods after harvest. The lowest weight loss rate of P. gilvus mushroom was 75.8% with drying in the shade and 80% by dryer (60°C). The size loss rate of pileus was 19.3% of that in a hot air dryer (60°C). The hardness of dried material context using a hot air dryer (60°C) was the lowest (20 kg/cm²), and that by a dry oven (60°C) was the highest (457 kg/m²). For ΔE value, 4.9 of context and 2.6 of tubes using drying in the shade (20°C) were found to be the lowest. The survival rate of sarcoma 180 treated with P. gilvus dried in the sun was the lowest (51.8%), and this was considered the most effective method for antitumor activity against sarcoma 180.     

Regulation of magnesium-inhibited cation current by actin cytoskeleton rearrangement

Magnesium-inhibited, non-selective cation current (I(MIC)) is activated by depletion of intracellular Mg(2+) and ATP. I(MIC) transports various divalent cations including Mg(2+) and Ca(2+), and is involved in cell viability. We investigated the effect of actin dynamics on I(MIC). Formation of a stable cortical actin network by calyculin A inhibited the activation of I(MIC), while the actin depolymerizing reagent, cytochalasin D, reversed the inhibition. Induction of a dense cortical actin layer by transfecting the constitutively active form of RhoA also inhibited the activation of I(MIC). These results suggest that the activation of I(MIC) may be dynamically regulated by actin cytoskeleton rearrangement.     

Possible involvement of Class III phosphatidylinositol-3-kinase in meiotic progression of porcine oocytes beyond germinal vesicle stage

Phosphatidylinositol-3-kinases (PI3Ks) play pivotal roles in meiotic progression of oocytes from metaphase I to metaphase II stage. Using a Class III-specific inhibitor of PI3K, 3-methyladenine (3MA), this study shows that Class III PI3K may be essential for meiotic progression of porcine oocytes beyond germinal vesicle (GV) stage. Treatment of immature porcine oocytes with 3MA for 22-42 h arrested them at the GV stage, irrespective of the presence or absence of cumulus cells. Furthermore, a significantly high proportion (60.9 ± 13.8%) of 3MA-treated oocytes acquired a nucleolus completely surrounded by a rim of highly condensed chromatin (GV-II stage). The GV-arresting effect of 3MA was, however, completely reversible upon their further culture in the absence of 3MA for 22 h. When cumulus-oophorus-complexes (COCs), arrested at the GV stage for 22 h by 3MA, were further cultured for 22 h in the absence of 3MA, 96.1 ± 1.5% of oocytes reached the MII stage at 42 h of IVM and did not differ from non-treated control oocytes with respect to their ability to fertilize, cleave and form blastocyst (P > 0.05) upon in vitro fertilization (IVF) or parthenogenetic activation (PA). These data suggest that 3MA efficiently blocks and synchronizes the meiotic progression of porcine oocytes at the GV stage without affecting their ooplasmic maturation in terms of post-fertilization/activation in vitro embryonic development. Our data also provide indirect evidence for the likely participation of Class III PI3K in meiotic maturation of porcine oocyte beyond the GV stage.     

The C-terminal domain of PLD2 participates in degradation of protein kinase CKII β subunit in human colorectal carcinoma cells

Elevated phospholipase D (PLD) expression prevents cell cycle arrest and apoptosis. However, the roles of PLD isoforms in cell proliferation and apoptosis are incompletely understood. Here, we investigated the physiological significance of the interaction between PLD2 and protein kinase CKII (CKII) in HCT116 human colorectal carcinoma cells. PLD2 interacted with the CKIIβ subunit in HCT116 cells. The C-terminal domain (residues 578-933) of PLD2 and the N-terminal domain of CKIIβ were necessary for interaction between the two proteins. PLD2 relocalized CKIIβ to the plasma membrane area. Overexpression of PLD2 reduced CKIIβ protein level, whereas knockdown of PLD2 led to an increase in CKIIβ expression. PLD2-induced CKIIβ reduction was mediated by ubiquitin-dependent degradation. The C-terminal domain of PLD2 was sufficient for CKIIβ degradation as the catalytic activity of PLD2 was not required. Taken together, the results indicate that the C-terminal domain of PLD2 can regulate CKII by accelerating CKIIβ degradation in HCT116 cells.     

Association of glutathione S-transferase gene polymorphisms (GSTM1 and GSTT1) of vitiligo in Korean population

Vitiligo is an acquired pigmentary disorder of the skin involving melanocyte dysfunction. It has been reported that melanocyte impairment could be related to increased oxidative stress. The glutathione S-transferases (GSTs) are group of polymorphic enzymes that are important in protection against oxidative stress. To find the relationship between GSTM1 and GSTT1 polymorphisms with vitiligo susceptibility, GSTM1 and GSTT1 (homozygous deletion vs. non-deleted) polymorphisms between vitiligo patients (n=310) and healthy controls (n=549) were analyzed. We observed significant association in null alleles of the GSTM1 (P<0.001, OR=2.048, 95% CI=1.529-2.743). GSTM1 null type was also statistically different between two vitiligo subtypes and controls (Focal P<0.001, OR=2.224, 95% CI=1.499-3.298; Generalized P=0.001, OR=1.974, 95% CI=1.342-2.904). However, no significant association in GSTT1 (P=0.869, OR=1.024, 95% CI=0.775-1.353) was observed with vitiligo. In combined analysis of GSTM1 and GSTT1, both null type and GSTM1/GSTT1 (null/present) group showed significant differences between controls and vitiligo patients. These results suggest that GSTM1 null type might be associated with vitiligo susceptibility in Korean population.     

Low Left Atrial Compliance Contributes to the Clinical Recurrence of Atrial Fibrillation after Catheter Ablation in Patients with Structurally and Functionally Normal Heart

Stiff left atrial (LA) syndrome was initially reported in post-cardiac surgery patients and known to be associated with low LA compliance. We investigated the physiological and clinical implications of LA compliance by estimating LA pulse pressure (LApp) among patients with atrial fibrillation (AF) and structurally and functionally normal heart. Among 1038 consecutive patients with LA pressure measurements before AF ablation, we included 334 patients with structurally and functionally normal heart (81.7% male, 54.1±10.6 years, 77.0% paroxysmal AF) after excluding those with hypertension, diabetes, and previous ablation or cardiac surgery. We measured LApp (peak-nadir LA pressure) at the beginning of the ablation procedure and compared the values with clinical parameters and the AF recurrence rate.AF patients with normal heart were younger and more frequently male and had paroxysmal AF, a lower body mass index, and a lower LApp compared to others (all p<0.05).Based on the median value, the low LA compliance group (LApp≥13mmHg) had a smaller LA volume index and lower LA voltage (all p<0.05) compared to the high LA compliance group. During a mean follow-up of 16.7±11.8 months, low LA compliance was independently associated with two fold-higher risk of clinical AF recurrence (HR:2.202; 95%CI:1.077–4.503; p = 0.031).Low LA compliance, as determined by an elevated LApp, was associated with a smaller LA volume index and lower LA voltage and independently associated with higher clinical recurrence after catheter ablation in AF patients with structurally and functionally normal heart.     

Perilla frutescens Leaf Extract Attenuates Vascular Dementia-Associated Memory Deficits,Neuronal Damages,and Microglial Activation

Vascular dementia (VaD) is characterized by a time-dependent memory deficit and essentially combined with evidence of neuroinflammation. Thus, polyphenol-rich natural plants, which possess anti-inflammatory properties, have received much scientific attention. This study investigated whether Perilla frutescens leaf extract (PFL) exerts therapeutic efficacy against VaD. Sprague Dawley rats were divided into five groups: SO, sham-operated and vehicle treatment; OP, operated and vehicle treatment; PFL-L, operated and low-dose (30 mg/kg) PFL treatment; PFL-M, operated and medium-dose (60 mg/kg) PFL treatment; and PFL-H, operated and high-dose (90 mg/kg) PFL treatment. Two-vessel occlusion and hypovolemia (2VO/H) were employed as a surgical model of VaD, and PFL was given orally perioperatively for 23 days. The rats underwent the Y-maze, Barnes maze, and passive avoidance tests and their brains were subjected to histologic studies. The OP group showed VaD-associated memory deficits, hippocampal neuronal death, and microglial activation; however, the PFL-treated groups showed significant attenuations in all of the above parameters. Using lipopolysaccharide (LPS)-stimulated BV-2 cells, a murine microglial cell line, we measured PFL-mediated changes on the production of nitric oxide (NO), TNF-α, and IL-6, and the activities of their upstream MAP kinases (MAPKs)/NFκB/inducible NO synthase (iNOS). The LPS-induced upregulations of NO, TNF-α, and IL-6 production and MAPKs/NFκB/iNOS activities were globally and significantly reversed by 12-h pretreatment of PFL. This suggests that PFL can counteract VaD-associated structural and functional deterioration through the attenuation of neuroinflammation.     

Bovine and feline gastrin cDNA sequences and the amino acid and nucleotide sequence homologies among mammalian species.

The complete nucleotide sequences of cDNAs encoding bovine and feline preprogastrins have been cloned from the antral mucosa mRNA. The gastrin mRNA of each animal encodes a preprogastrin of 104 amino acids consisting of a signal peptide, a prosegment of 37 amino acids, and a gastrin 34 sequence, followed by a glycine (the amide donor). The cleavage following a pair of lysine residues yields gastrin 17. We found that pairs of arginine residues flanking gastrin 34, the typical processing site sequence of all other preprogastrins and many peptide hormones, were arginines in the bovine preprogastrin, but the first basic amino acid pair had changed to Arg-Trp (57-58 residues) instead of Arg-Arg in the feline preprogastrin. Comparison of these amino acid and nucleotide sequences with published mammalian sequences showed extensive homology in the coding (63 to 73% amino acid identity) and in the untranslated regions (67 to 89% identity). Prosequence, the most variable region, shows greater amino acid difference between bovine and human preprogastrin (54% identity), and between bovine and rat preprogastrin (54% identity) than between other species (62 to 82% identity).