The notion that dental amalgam is a potential source of mercury exposure remains a controversial issue. However, there are few epidemiological analyses that have addressed whether this occurs in children. We aimed in our current study to identify the relationship between dental amalgam filling surfaces and the blood mercury levels in a cohort of 711 South Korean children aged between 8-9 years. Oral examinations were conducted to detect the number of amalgam filling surfaces on the teeth of these individuals. Blood samples were also taken from these children to assess the levels of mercury accumulation in the body. The amalgam filling surfaces were classified into four groups based on their number: 0 (n = 368), 1-5 (n = 219), 6-10 (n = 89), and 11+ (n = 35). The blood mercury levels in the children with more than 10 amalgam surfaces was 0.47 μg/L higher on average than those with no amalgam surfaces after adjusting for the frequency of fish or seafood consumption, age, and gender (P < 0.05). We found from our data that a higher number of dental amalgam fillings correlated with a higher blood mercury level in Korean children. Further studies are needed to investigate whether these elevated mercury levels exert neurotoxic or nephrotoxic effects.

A new cultivar "KNR10-1" of Pleurotus eryngii was developed by the method of mono-mono crossing between monokaryotic strains derived from KNR2594 and KNR2610, respectively. The optimum temperature of mycelial growth was 25℃ and that of fruiting body development was 15 - 16℃. The period of harvesting including primordia formation of "KNR10-1" was one day faster than that of control strain KNR2312. The color of pileus and stipe surface was neutral-brown and pure white, respectively. The shape of pileus was dome and has the teeth of a comb. The yield was 90±12.9g/850cc plastic bottle. The fruit body has a longer shelf life than control strain KNR2312 at 4℃. Analysis of the genetic characteristics of the new commercial strain "KNR10-1" showed a different profile as that of the control strain KNR2312 when RAPD (Random Amplified Polymorphic DNA) primers were used. This new variety of King Oyster mushroom is characterized by the improved storability after harvesting.

Harmonized actions of ovarian estrogen (E2) and progesterone (P4) regulate cell proliferation and differentiation in the uterus with a spatiotemporal manner. Imbalance between the actions and levels of two major regulators often lead to infertility and gynecological diseases, such as endometriosis and endometrial cancer. While numerous works have shown that reduced expression and/or deletion of uterine factors associated with P4 signaling could disturb uterine physiology, local factor(s) to mediate E2 actions has not been extensively studied yet. Here we demonstrate that early growth response 1 (Egr1), a transcription factor which is rapidly induced in the uterus by E2, is required to maintain coordinated actions of E2 and P4 for uterine receptivity for embryo implantation. Given exogenous gonadotrophins to overcome LHβ deficiency in the pituitary of Egr1(－/－) mice, ovulation, fertilization and embryo development normally occurred in these mice. However, they showed complete failure of embryo implantation with reduced uterine responses to artificial decidualization stimuli. While serum levels of E2 and P4 in Egr1(－/－) mice were comparable, genes regulated by E2 and/or P4 in uterine epithelial cells (ECs) were aberrantly expressed on day 4 of pregnancy. Impaired P4 signaling along with absence of PR in ECs caused hypersensitive E2 responses shown as enhanced expression of E2-responsive genes such Muc1 and Ltf as well as reduced levels of P4-dependent genes, such as Ihh and Areg, in ECs of Egr1(－/－) mice. This is consistent with persistent proliferation in ECs and severely impaired proliferation in stromal cells (SCs) in Egr1(－/－) mice treated with E2+P4. Furthermore, primary co-culture of Egr1(－/－) ECs with Egr1(+/+) SCs and vice versa supported a notion that Egr1 itself is required for proper responses to two major regulators, E2 and P4, in both uterine cell compartments. Collectively, our results show that E2-induced Egr1 participates in P4-dependent modulation on E2 activities in the uterus by regulating a spectrum of genes essential for uterine receptivity and embryo implantation.

DGCR8 is a RNA-binding protein working with DROSHA to produce pre-microRNA in the nucleus, while DICER does not only mature microRNA but also endogenous siRNAs in the cytoplasm. Here, we have produced Dgcr8 conditional knock-out mice using progesterone receptor (PR)-Cre (Dgcr8flox/flox; PRcre/+ mice, Dgcr8d/d) and demonstrated that canonical microRNAs dependent of DROSHA-DGCR8 complex are required for uterine development as well as female fertility in mice. Adult Dgcr8d/d females did not undergo regular reproductive cycle and produce any pups when housed with fertile males, whereas administration of exogenous gonadotropins induced normal ovulation with corpus luteal formation in these mice. Ovulated oocytes from Dgcr8d/d mice had comparable fertilization potentials and were normally developed to the blastocyst after fertilization as compared to those in control Dgcr8f/f mice. Interestingly, PR-Cre-dependent Dgcr8 deletion showed aberrant infiltration of acute inflammatory immune cells to female reproductive organs only when Dgcr8d/d mice were mated with male mice. With respect to uterine development, gross morphology, histology, and weight of Dgcr8d/d uterus were similar to those of control at 3-week-old age. However, multiple uterine abnormalities were noticeable at 4-week-old age when PR expression is significantly increased, and these deformities became severe onwards. Gland formation and myometrial layers were significantly reduced, and stromal cell compartment did not expand and became atrophic during uterine development in these mice. These results were consistent with aberrantly reduced cell proliferation in stromal cell compartments of Dgcr8d/d mice. Collectively, our results suggest that DGCR8 dependent-canonical microRNAs are essential for development and physiology of the uterus with respect to morphogenesis, proper immune modulation, reproductive cycle, and steroid hormone responsiveness in mice.

The objective of this study was determined to evaluate α-amylase, α-glucosidase, pancreatic lipase inhibition in vitro and DPPH radical scavenging activity of the several Korean resources plants. The α-amylase inhibitory activity of Salicornia herbacea, Erythronium japonicum (flower) and Phragmites communis (root) in water extract showed relatively high 62.8%, 66.5% and 69.3%, respectively. The α-amylase inhibitory activity of Citrus junos (pericarp) and Cornus officinalis in methanol extract was found to have an effect with 32.8% in Citrus junos (pericarp) and 60.9% in Cornus officinalis. Corylopsis coreana in both water and methanol extract had the highest α-glucosidase inhibitory activity of 81.7% and 89.5%, while the extract of Portulaca oleracea, Ficus carica and Citrus junos was not measured α-glucosidase inhibitory activity at given experiment concentration. Depending on the extraction solvent and the plant species, it was observed that there was a significant difference in α-glucosidase inhibitory activity. The pancreatic lipase inhibitory activity showed relatively higher in the methanol extract than water extract except pericarp of Citrus junos. The DPPH radical scavenging activity of selected plants was much difference between measured plant species, and showed that the increase was proportional to the concentration. These results suggested that selected plants had the potent biological activity on carbohydrate, lipid Inhibitory activity and antioxidant activity, therefore these plant resources could be a good materials to develop medicinal preparations, nutraceuticals or health functional foods for diabetes or obesity.

The antioxidant potential and enzyme activities in Salicornia herbacea, Corylopsis coreana, Erythronium japonicum, Phragmites communis, Momordica Charantia, Nelumbo nucifera, Salvia plebeia, Portulaca oleracea, Ficus carica, Citrus junos and Cornus officinalis were determined. Their antioxidant activities were measured using DPPH radical scavenging and nitrite scavenging activity. Enzyme activities in investigated plants were evaluated as superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX). The DPPH scavenging rate from 100 to 2500 mgL-1 was the highest in the flower of Corylopsis coreana. However, it was not detected in most of the samples at concentration below 100 mgL-1. The nitrite scavenging activity according to each kind of resource plants was significantly higher in the stem of Corylopsis coreana and leaf of Nelumbo nucifera. The root extract of Erythronium japonicum had the highest SOD enzyme activity of 94.0% while leaf of Salvia plebeia showed the lowest SOD enzyme activity of 30.4%. The activity of CAT and APX showed higher values in the stem of Corylopsis coreana, root of Erythronium japonicum and root of Phragmites communis in comparison with other plants. The activity of POD showed significantly high values in stem of Corylopsis coreana, Momordica Charantia and pericarp of Citrus junos extracts. The antioxidant enzyme activities differ significantly in different plants. In conclusion, we showed that Corylopsis coreana, Erythronium japonicum Cornus officinalis, and Momordica Charantia had the potent biological activities. Therefore, these plant resources showing antioxidant activity could be good materials for development of source of functional healthy food.

Ethanol treatment during the brain growth spurt period has been known to induce the death of Purkinje cells. The underlying molecular mechanisms and the role of reactive oxygen species (ROS) in triggering ethanol-induced Purkinje cell death are, however, largely unresolved. We undertook TUNEL staining, western blotting assay and immunohistochemistry for the cleaved forms of caspase-3 and -9, with calbindin D28K double immunostaining to identify apoptotic Purkinje cells. The possibility of ROS-induced Purkinje cell death was immunohistochemically determined by using anti-8-hydroxy-2'deoxyguanosine (8-OHdG), a specific cellular marker for oxidative damage. The results show that Purkinje cell death of PD 5 rat cerebellum following ethanol administration is mediated by the activation of caspase-3 and -9. However, unexpectedly, TUNEL staining did not reveal any positive Purkinje cells while there were some TUNEL-positive cells in the internal and external granular layer. 8-OHdG was detected in the Purkinje cell layers at 8 h, peaked at 12-24 h, but not at 30 h post-ethanol treatment. No 8-0HdG immunoreactive cells were detected in the internal and external granular layer. The lobule specific 8-OHdG staining patterns following ethanol exposure are consistent with that of ethanol-induced Purkinje cell loss. Thus, we suggest that ethanol-induced Purkinje cell death may not occur by the classical apoptotic pathway and oxidative damage is involved in ethanol-induced Purkinje cell death in the developing cerebellum.