• The Korean Journal of Pesticide Science
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• v.6 no.1
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• pp.16-24
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• 2002

Research trends in the measurement of foliar uptake of pesticides and the recently proposed action mechanism of the surfactant-induced uptake of pesticides were reviewed with the related reports and studies. Major techniques used in those fields are bioassay, radiotracer techniques with leaves or cuticular membrane. Recently, a new method using Congo Red as a tracer was proposed. The limiting factor in the pesticides uptake into leaves is the waxy layer which consists of the epicuticular and cuticular wax. Physico-chemical parameters such as molar volume, water solubility and partition coefficient of pesticides have limited influences on the pesticide uptake into leaves. Polydisperse ethoxylated fatty alcohol surfactants are well known as the good activator for many pesticides. It is now generally agreed that uptake activation is not related to the intrinsic surface active properties of surfactants such as surface activity, solvent property, humectancy and critical micelle concentration. Recent studies using ESR-spectroscopy revealed that the surfactants have an unspecific plasticising effect on the molecular structure of the wax and cuticular matrix, leading to increased mobilities of pesticides. Penetration of surfactants into waxy layer altered the pesticide mobility in wax and the partition coefficient of pesticide, and then the pesticides penetration into leaves was enhanced temporally. The enhancing effect of surfactant could be significantly different depending on the carbon number of aliphatic moiety and the number of ethoxy group in polyoxyethylene chain of surfactants. It is suggested that the rate of penetration of surfactants should have a significant relationship with the rate of penetration of pesticides.

• Journal of agriculture & life science
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• v.44 no.4
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• pp.45-55
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• 2010

In this study, the acetylcholinesterase (AChE) inhibition and neuronal cell protective effects of water, 100% methanol and dichlromethane extracts from garlic were investigated. We found that dichloromethane extract of garlic resulted in a dose-dependent manner on AChE inhibition ($IC_{50}$: $36.1{\mu}g/mL$). In cell viability assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide (MTT), cell viabilities of water, 100% methanol and dichlromethane extracts were lower (almost under 40%) than amyloid ${\beta}$ protein ($A{\beta}$)-induced neurotoxicity. Because $A{\beta}$ is also known to increase neuronal cell membrane breakdown, neuronal apoptosis was further confirmed by lactate dehydrogenase (LDH) and neutral red uptake (NRU) assay. Water extract presented relative protection against $A{\beta}$-induced membrane damage in LDH assay. However all garlic extracts showed significant problem with decrease of cell viability in NRU assay, especially at dichloromethan extract. To determine active compounds in column fractions (98:2 fraction) from dichloromethane extract which showed significant AChE inhibitory effect, we performed HPLC and LC-MS analysis. It was supposed that garlic may contain allyl methyl disulfide, diallyl monosulfide, and diallyl disulfide as active compounds.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.2
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• pp.233-239
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• 2017

Intracellular calcium ($Ca^{2+}$) oscillation is an initial event in digestive enzyme secretion of pancreatic acinar cells. Reactive oxygen species are known to be associated with a variety of oxidative stress-induced cellular disorders including pancreatitis. In this study, we investigated the effect of hydrogen peroxide ($H_2O_2$) on intracellular $Ca^{2+}$ accumulation in mouse pancreatic acinar cells. Perfusion of $H_2O_2$ at $300{\mu}M$ resulted in additional elevation of intracellular $Ca^{2+}$ levels and termination of oscillatory $Ca^{2+}$ signals induced by carbamylcholine (CCh) in the presence of normal extracellular $Ca^{2+}$. Antioxidants, catalase or DTT, completely prevented $H_2O_2$-induced additional $Ca^{2+}$ increase and termination of $Ca^{2+}$ oscillation. In $Ca^{2+}$-free medium, $H_2O_2$ still enhanced CCh-induced intracellular $Ca^{2+}$ levels and thapsigargin (TG) mimicked $H_2O_2$-induced cytosolic $Ca^{2+}$ increase. Furthermore, $H_2O_2$-induced elevation of intracellular $Ca^{2+}$ levels was abolished under sarco/endoplasmic reticulum $Ca^{2+}$ ATPase-inactivated condition by TG pretreatment with CCh. $H_2O_2$ at $300{\mu}M$ failed to affect store-operated $Ca^{2+}$ entry or $Ca^{2+}$ extrusion through plasma membrane. Additionally, ruthenium red, a mitochondrial $Ca^{2+}$ uniporter blocker, failed to attenuate $H_2O_2$-induced intracellular $Ca^{2+}$ elevation. These results provide evidence that excessive generation of $H_2O_2$ in pathological conditions could accumulate intracellular $Ca^{2+}$ by attenuating refilling of internal $Ca^{2+}$ stores rather than by inhibiting $Ca^{2+}$ extrusion to extracellular fluid or enhancing $Ca^{2+}$ mobilization from extracellular medium in mouse pancreatic acinar cells.

• Journal of Periodontal and Implant Science
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• v.29 no.1
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• pp.233-249
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• 1999

Primary fixation is one of the most important factor in establishing adequate osseointegration between implant and bone. To evaluate the initial healing response of bone around implants without primary bone contact, this study was designed to create considerable space between implant and bone in 5 mongrel dogs, about 1-year old. After 3 holes of 6.0mm in diameter were prepared at the femur neck of the dogs, commercially pure titanium thread type implants(STERI-$OSS^{(R)}$), 8mm in length and 3.8mm, 5.0mm and 6.0mm in diameter, were inserted. Implants were supported by only nonresorbable membrane($Teflon^{(R)}$), and the penetration of upper soft tissue into the gap was inhibited by it. The each implant was positioned in the center of the drilled hole. 9 implants with different diameters were inserted in 3 dogs for histologic observation, and 12 were inserted in 2 dogs for mobility test and removal torque test.Fluorescent dyes were injected in order of Doxycycline, Alizarin Red S, and Calcein at intervals of 2 weeks. At 4-, 8-, and 12-week after placement, 3 dogs were sacrificed for histologic observation, and at 8- and 12-week after placement, 2 dogs were sacrificed for mobility test using $Periotest^{(R)}$ (Simens AG, Bensheim, Germany) and torque test using Autograph AGS-1000D $series^{(R)}$(Japan). The result were as follows: 1. The wider the gap between bone and implant was, the less bone maturity was, and the later osseointegration was occurred. Trabecular direction of new bone around implant was changed from parallel to perpendicular to the implant, and the gap was filled with new bone, over time. 2. There was a decreasing tendency over time in the mobility of all implants, but the wider gap between bone and implant was, the smaller decrease of the mobility was. 3. There was a increasing tendency over time in the removal torque gauge of all implants, and the wider gap was, the smaller increase of the removal torque gauge was. The results suggest that osseointegration in case of implant without primary bone contact may be obtained by guided bone regeneration technique with prolonged healing period, but the time of second surgery should be considered carefully.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.1
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• pp.64-80
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• 1998

The risk of cross-contamination in dental clinic is very high. Those who are engaged in dental clinic are exposed to various microorganisms in saliva and blood of patient. Potential possibility of cross-contamination of patient to patient, patient to dentist, dentist to laboratory technician always exist, which is important in the view of public health. It is well known that microorganisms may cause cross-contamination by suck-back of microorganisms into the water supply line or air supply line of dental unit and sprayed back into the next patient's oral cavity. The majority of microorganisms coming from dental unit are water microorganisms from the main water supply which have colonized the tube within the units and multiplied in the relatively warm and stagnant conditions. The purpose of this study is to measure the extent of microbial contamination of dental unit and ultrasonic scaler, to evaluate that dental unit water supply is suitable for drinking water, and to assess the effect of flushing on reduction of microbial contamination of dental unit and ultrasonic scaler. In the first experiment, water samples(50ml) from 20 dental units and 10 ultrasonic scalers in Seoul National Univ. Hosp. were tested for the presence of coliform. The samples were filtered by membrane filtration technique.(Microfil system, Millipore Co. U. S. A.) The filter was then placed onto MacConkey agar plate and the plates with filter on it were incubated aerobically at $37^{\circ}C$ for 5 days. The colors and shapes of colonies were examined if those were coliform. To verify the presence of coliform, the colonies were inoculated into phenol red lactose broth and incubated aerobically at $37^{\circ}C$ for 2 days. The fomation of gas was observed. In the second experiment, water samples from 20 handpieces, 10 ultrasonic scalers and 30 A/W syringes after 0, 2, 4, 6 min. flushing respectively were taken. $200{\mu}l$ water samples were spreaded on Brain Heart Infusion agar plate and the plates were incubated aerobically at $37^{\circ}C$ for 5 days. The number of colony was counted. The results obtained were summarized as follows 1. The water from dental unit and ultrasonic scaler was not suitable for drinking water. 2. No coliform was founded in dental unit and ultrasonic scaler water supply. 3. The number of colony of dental unit and ultrasonic scaler was highest in the group of o min. flushing(p<0.05). 4. There was no statistically significant difference in the extent of microbial contamination among handpiece, ultrasonic scaler and A/W syringe (p>0.05). 5. The number of colony was lowest in the group of 4 min. flushing, but there was no statistically significant difference among 2, 4, 6 min. flushing groups.(p>0.05) 6. It is recommended to flush dental unit water line for 4 min. after use on each patient.

• Journal of Periodontal and Implant Science
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• v.29 no.2
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• pp.415-433
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• 1999

Implant stability is the key to long-term successful outcome for osseointegrated implants. To evaluate the initial healing response of bone around HA-coated implants without primary bone contact. 21 HA-coated thread type implants(STERI-OSS?) were placed in the femurs of 5 mongrel dogs, about 1-year old. Implants, 8 mm in length and 3.8mm(experimental 1group), 5.0mm(experimental 2group) and 6.0mm(control group) in diameter, were inserted after 3 holes of 6.0mm in diameter and 10mm in depth were prepared in the surgical sites each dog. Implants were supported by only nonresorbable membrane($Teflon^{(R)}$), in order to prevent the ingrowth of upper soft tissue into the gap between bone and implant, and to maintain each implant to be positioned in the center of the drilled hole. 9 implants with different diameters were inserted in 3 dogs for histologic observation, and 12 implants were inserted in 2 dogs for mobility test and removal torque test. Fluorescent dyes were injected for the observation of new bone formation in order of $Terramycin^{(R)}$, Arizarin $Red^{(R)}$, and $Calcein^{(R)}$ at an interval of 2 weeks. 3 dogs were sacrificed for histologic observation at 4, 8, and 12-week after placement. Light microscopy and confocal laser scanning microscopy were used to qualitatively characterize the bone around HA-coated implant. 2 dogs were sacrificed for mobility test($Periotest^{(R)}$, Simens AG, Bensheim, Germany) and removal torque test($Autograph^{(R)}$ AGS-1000D series, Japan) at 8 and 12-week after placement The results were as follows: 1. Histologic observation showed that osseointegration occurred to both control and experimental groups as time lapse, but delayed bone healing was revealed in 3.8mm group (experimental 1group), compared to contrtol group and 5.0mm group (experimental 2group). 2. The mobility test showed that the experimental groups had no distinguishable movement during experimental periods of 8 and 12-week, and there was no difference in mobility depending on the gap between bone and implant, and time lapse. 3. The removal torque forces were increased depended on the gaps decreasing between bone and implant, and time lapse. The results suggest that HA-coated implant without primary bone contact, based on guided bone regeneration could obtain its stability in all experimental groups as time lapse, but bone healing was delayed in experimental group of 3.8mm. And the results suggested that studies on correlationship between mobility test and removal torque test for implant stability would be necessary.

• Korean Journal of Food Science and Technology
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• v.43 no.2
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• pp.206-212
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• 2011

Makgeolli is Korean traditional alcoholic beverage that has historically been brewed. In this study, we analyzed the profile of organic acids in makgeolli and also evaluated its physiological characteristics. Makgeolli contained excess lactic acid, which is produced by lactic acid bacteria (LAB). Anti-obesity effects of makgeolli were investigated in 3T3-L1 preadipocytes. Compared to the negative control, makgeolli inhibited the differentiation of preadipocyte as quantified by Oil red O dye. In particular, $100{\mu}g/mL$ makgeolli reduced 40 to 70% of differentiation. To evaluate the anti-angiogenic and anti-inflammatory effects of makgeolli, we performed chorioallantoic membrane assay and measured nitric oxide production from lipopolysaccharide-induced RAW264.7 cells. Most makgeolli interrupted the formation of neo-vasculature and significantly inhibited NO production in a dose-dependent manner. Taken together, these findings suggest that commercial makgeolli has inhibitory activities against adipogenesis, neo-vascularization, and inflammation, and also they are influenced by second metabolites from nuruk microflora containing fungi and LAB.

• Journal of Nutrition and Health
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• v.9 no.4
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• pp.19-27
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• 1976

Perilla (frutescens) seed oil, which is widely used as a source of vegetable oil in Korea, contains a strikingly large amount (58.4% of total fatty acids) of polyunsaturated linolenic acid (18 : 3) which is one of the essential fatty acids. Our hypothesis was that vitamin E contained in this oil would not be enough to prevent peroxidation of this polyunsaturated oil. A comparative study was carried out using rats and chicks devided into seven groups with various diet combinations emphasizing fat sources for the period of four weeks. The level of fat in each diet was 15% and animals were fed ad libitum. Various diet combinations were as follows; perilla seed oil and sesame seed oil with and without vitamin E supplementation, tallow as a saturated fat source and perilla seed hull group (10% at the expense of carbohydrate). The fat constituents of control group were consisted of 50% vegetable oil and 50% animal fat. A few important findings are as follows: 1. Rats fed perilla seed oil lost their hair focally around the neck and suffered from a bad skin lesion at the same place. In chicks, yellow pigmentation both of feather and of skin was clearly observed only in groups fed perilla seed oil with or without vitamin E supplementation. The basis of biochemical mechanisms of this phenomena remains as an important research interest. 2. The mean value for hematocrit was significantly lower for the chicks fed perilla seed oil than for those fed control diet. This result seems to be attributable to the effect on the red cell membrane known as peroxidation-hemolysis of vitamin E deficiency. 3. The serum cholesterol level was higher for the rats fed perilla seed oil than for those fed control diet, whereas in chicks the group fed perilla seed oil showed lower value than the control group indicating that different animal species could vary in their responses to the same diet. 4. In pathological examinations, the sign of hepatic fibrosis was seen in the perilla seed hull group and it was noticeable that the level of hepatic RNA was significantly increased in the rat recovering from vitamin E deficiency. It is hoped that more detailed studies on perilla seed oil and hulls will soon be carried out in many aspects especially i) at various levels of fat in the diet, ii) in relation to dietary selenium level and iii) to find an optimum level of dietary essential fatty acids in terms of P/S ratio using various animal species. In the mean time, the public should be informed to preserve this particular oil with care to minimize fatty acid oxidation and should be discouraged from overconsuming this oil. This study was supported by UB (United Board) Research Grant (Graduate School, Yonsei University, Seoul, Korea)

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.148-152
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• 2000

To provide basic information on the integumentary system of the blenny, Pholis nebulosa, ultrastructures of epidermal and dermal layer were examined by means of the light and transmission electron microscope. The skin of the blenny consisted of epidermal and dermal layer. Epidermal layer consisted of supporting cell and unicellular gland. The supporting cells were classified into superficial cell, intermediated cell and basal cell, and the gland cells were classified into mucous secretory cell and club cell. The cytoplasm of supporting cells was divided into cortex and medullar part. In the cortex and medullar part, microfilaments and cell organelles were well developed, respectively. Superficial cell of epidermal layer was cuboidal and contained nucleus of horseshoe shape. Intermediated cell had a nucleus of irregular form and the electron density was higher than the other supporting cells, Basal cell was columnar, but nucleus was situated in the upper cytoplasm. Cell organelles of the basal cell were poor than the other supporting cells, but membrane interdigitations were well developed. The cytoplasm of mucous secretory cell had a well-developed ovoid secretory granules, which reacted to red with AB-PAS reaction. The club cell had a we31-developed round secretory granules and endoplasmic reticulum. figment cells were classified into two type. The one contained pigment granules of electron dense, and the other contained reflecting platelets. The cytoplasm of fibrocyte had n well developed rough endoplasmic reticulum.

• Journal of Nutrition and Health
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• v.41 no.5
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• pp.428-438
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• 2008

Choline is important for normal membrane function, acetylcholine synthesis and methyl group metabolism. In this study, 185 food items customarily eaten by Koreans were selected from the data of the 2001 Korean National Health and Nutrition Survey and analyzed on the total choline content of the foods using enzymatic method of choline oxidase. Foods with high choline concentration (mg/100 g) were listed in sequence of quail egg (476.04 mg), dried squid (452.42 mg), beef liver (427.16 mg), pork liver (424.92 mg), tuna canned in oil (414.44 mg), boiled and dried anchovy (381.30 mg), dried Alaskan pollack (378.88 mg), chicken egg (309.88 mg), chicken liver (259.38 mg), soybean (238.62 mg), French bread with garlic (193.18 mg) and barley (183.73 mg). From this result, it is shown that dried fishes, prepared fishes, livers, eggs, pulses and cereals might be categorized as high choline food. Citron tea and green tea showed low choline content below 1 mg. Vegetables and fruits were also categorized into low choline food. No choline was detected in red pepper powder, beer, soju, soybean oil and corn oil out of foods analyzed in this study. Further study is required for analytic procedure of the foods of which results are inconsistent with USDA's data such as rice and wheat flour.