• Molecular & Cellular Toxicology
• /
• v.3 no.1
• /
• pp.11-18
• /
• 2007

Mechanisms of insecticide resistance found in insects may include three general categories. Modified behavioral mechanisms can let the insects avoid the exposure to toxic compounds. The second category is physiological mechanisms such as altered penetration, rapid excretion, lower rate transportation, or increased storage of insecticides by insects. The third category relies on biochemical mechanisms including the insensitivity of target sites to insecticides and enhanced detoxification rate by several detoxifying mechanisms. Insecticides metabolism usually results in the formation of more water-soluble and therefore more readily eliminated, and generally less toxic products to the host insects rather than the parent compounds. The representative detoxifying enzymes are general esterases and monooxygenases that catalyze the toxic compounds to be more water-soluble forms and then secondary metabolism is followed by conjugation reactions including those catalyzed by glutathione S-transferases (GSTs). However, a change in the resistant species is not easily determined and the levels of mRNAs do not necessarily predict the levels of the corresponding proteins in a cell. As genomics understands the expression of most of the genes in an organism after being stressed by toxic compounds, proteomics can determine the global protein changes in a cell. In this present review, it is suggested that the environmental proteomic application may be a good approach to understand the biochemical mechanisms of insecticide resistance in insects and to predict metabolomic changes leading to physiological changes of the resistant species.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.10 no.1
• /
• pp.47-51
• /
• 2005

The bioelectrochemical reduction of nitrate in the presence of various mediators including methyl viologen and azure A was studied using a 3-electrode voltammetric system. The catalytic potential for the reduction of the mediators was observed in the reactor, which for methyl viologen and azure A were -0.74 V and -0.32 V, respectively, with respect to the potential of Ag/AgCl reference electrode. This potential was then applied to a working electrode to reduce each mediator for enzymatic nitrate reduction. Nitrite, the product of the reaction, was measured to observe the enzymatic nitrate reduction in the reaction media. Methyl viologen was observed as the most efficient mediator among those tested, while azure A showed the highest electron efficiency at the intrinsic reduction potential when the mediated enzyme reactions were carried out with the freely solubilized mediator. The electron transfer of azure A with respect to time was due to the adhesion of azure A to the hydrophilic surface during the reduction. In addition, the use of the adsorbed mediator on conductive activated carbon was proposed to inhibit the change in the electron transfer rate during the reaction by maintaining a constant mediator concentration and active surface area of the electrode. Azure A showed better than nitrite formation than methyl viologen when used with activated carbon.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.5
• /
• pp.484-489
• /
• 2011

This study examined whether N-acetylcysteine (NAC), a glutathione precursor, could attenuate toxic effects of three fish anti-parasitic agents, trichlorfon, hydrogen peroxide ($H_2O_2$) and formalin, all of which are known to exert side effects through free radical production. Common carp Cyprinus carpio were fed with NAC (approx. 50 mg/kg/day) for 3 consecutive days prior to anti-parasite bathing for a 24 hr period. Mortality rates were examined during this 24 hr bathing period, and selected hematological and biochemical parameters were also assessed at the termination of anti-parasite exposure. The mortality rates and plasma glucose elevations caused by all three anti-parasitics were significantly reduced by NAC pretreatment. Trichlorfon, but not $H_2O_2$ or formalin, elevated plasma levels of aspartatetransaminase (AST) and alanine-transaminase (ALT), and these elevations were attenuated by NAC. There was no change in hematocrit values in any treatment. The results provide evidence for the attenuating effects of NAC against toxicity caused by anti-parasite agents that act through free radical-producing properties. The results found in this study also suggest that NAC may be administered to fish to minimize toxicity in fish parasiticide use.

• Advances in Traditional Medicine
• /
• v.10 no.2
• /
• pp.66-78
• /
• 2010

Acute (24 h) and chronic (90 days) oral toxicity studies on the ethanol extract of Trigonella foenumgraecum Leguminosae (L.) seeds were carried out. Acute dosages were 0.5, 1.0 and 3 g/kg while chronic dosage was 100 mg/kg per day of the extract. All morphological, biochemical, haematological and spermatogenic changes, in addition to mortality, body weight changes and any change in vital organs were recorded. Histopathological investigations were done on vital organs. Growth arrest in the treated animals was observed. The treated mice gained no significant weight during chronic treatment while there was a significant gain in body weight of the control group mice. Biochemical studies revealed a significant decrease in blood sugar levels of fenugreek treatment groups while haematological parameters remained comparable to the control. In the treatment, male group there was a significant decrease in weight of testes as compared to the control. There was a marginal weight gain in kidney weight of mice after chronic treatment as compared to the control. Fenugreek chronic treatment caused a highly significant spermatotoxic effects in male mice.

• Korean Journal of Community Nutrition
• /
• v.8 no.4
• /
• pp.574-583
• /
• 2003

The purpose of this study was to investigate the anthropometry, biochemical parameters and electrolytes concentrations of the Total Parenteral Nutrition (TPN) patients according to their nutritional status at the time of admission. Thirty-three patients in the Intensive Care Unit at S University Hospital were the subjects of this study. Their nutritional status was classified as At-risk I (Mild PCM, n = 13), At - risk II (Moderate PCM, n = 9) and At-risk III (Marasmus + kwashiorkor + severe PCM, n = 11) . Anthropometeric, biochemical and dietary assessments were performed. The Patients intake of calories (75.02%) and protein (53.15%) was insufficient compare with Korean RDA requirements. The body weight and the Body Mass Index (BMI) in the At-risk III group were significantly lower than in the other groups. The percentage of body weight loss and change of body weight (kg) were significantly higher than in the other groups. The subjects were malnourished as indicated by nutritional related parameters such as serum total protein, albumin, total lymphocyte count (TLC), hemoglobin and hematocrit. Serum total protein, albumin and TLC levels were lower at the time of admission before TPN administration. But after TPN administration, they increased. The electrolyte concentrations did not show any differences following TPN administration. The nutritional status of the patients could be affect by the duration of TPN administration and the number of days of the patients hospitalization. The patients who require nutritional support need the continuous follow-up care and monitoring by a nutritional support team. (Korean J Community Nutrition 8(4) : 574-583, 2003)

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1995.04a
• /
• pp.96-96
• /
• 1995

It was recognized that lead intoxication reduces thiamine content in the brain of rat and this change produces the alterations of thiamine-related biochemical reactions. In the present study, it was tested whether the changes of myelin composition as well as seizure threshold induced by lead intoxication in rats may be related to these changes of thiamine status and thiamine related biochemical factors. Wistar rats were divided into five groups: Control group, Lead-treated group, Lead plus Thiamine-treated group, Thiamine-deficient group, Pyrithiamine-treated group. Each group was divided into three subgroups: 3, 7 and 16 week old group. Myelin protein and phospholipid, one of the compositions of myelin lipid, were measured in the myelin isolated from rat brain. Threshold of electric shock seizure was tested in each group. The amount of each myelin composition in lead-treated group and thiamine-deficient group was significantly lower than those of all the brains in control group, but recovery by supplementation with thiamine during lead intoxication was occurred only in the cerebellum of 3 week old animal. Thresholds of the electric shock seizure of lead treated group and thiamine deficient group in 3 and 7 week old rats were significantly lower than those of control group, while those of lead plus thiamine treated group were similar to those of control group.

• Applied Chemistry for Engineering
• /
• v.17 no.1
• /
• pp.33-36
• /
• 2006

The kinetics of photopolymerization of urethane-acrylate oligomer which has many applications in photopolymerizable adhesives was analysed to investigate the influence of polymerization temperature and functionality of oligomer using the autocatalytic model. It was revealed that the maximum polymerization rate decreased as the polymerization temperature increased. The reaction rate constant, k, showed little change with the increase in polymerization temperature, while exponents m and n exhibited an increase. These results could be related to the diffusion and mobility restriction of reactive species during the cross-linking reaction. The decrease in photopolymerization rate with increase of temperature was mainly controlled by the reaction order n.

• The Korean Journal of Food And Nutrition
• /
• v.17 no.4
• /
• pp.356-367
• /
• 2004

This study was performed to evaluate the effectiveness of a nutritional education program conducted by public health center in Jinju city for obese women. The subjects of this study consisted of 27 obese women(BMI $\geq$ 25) aged 35∼55 years in Jinju area, and the educational period was 6 weeks. We evaluated the anthropometric parameters and biochemical indices, dietary habits, dietary behaviors, nutritional attitude of obese women before and after the nutritional education. And also daily intake during the educational period were measured. Weight, obesity index, BMT, waist circumferences and hip circumferences of obese women were significantly decreased(p<0.001) after nutritional education, but changes of WHR, systolic blood pressure and diastolic blood pressure were not significant. There were no significant difference in total cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride, LDH and blood glucose level in serum before and after the nutritional education, but the indices tend to decrease after the nutritional education. There was significantly different change of dietary behaviors in 3 items among the dietary behavior after the nutritional education. Their dietary habit, dietary behavior and nutritional attitude scores were significantly improved after the nutritional education. Mean daily energy intakes was low compared with the RDA as 78.88%. The average carbohydrates, protein, fat ratio on the energy intakes was 63 : 17 : 20. The proportion of energy intake from snacks the was 12.91${\pm}$6.15%.

• Current Optics and Photonics
• /
• v.6 no.3
• /
• pp.337-343
• /
• 2022

Microfluidic chips are new devices that can manipulate liquids at the micrometer level, and terahertz (THz) time-domain spectroscopy has good applicability in biochemical detection. The combination of these two technologies can shorten the distance between sample and THz wave, reduce THz wave absorption by water, and more effectively analyze the kinetics of biochemical reactions in aqueous solutions. This study investigates the effects of different external magnetic field intensities on the THz transmission characteristics of deionized water, CuSO₄, CuCl₂, (CH₃COO)₂Cu, Na₂SO₄, NaCl, and CH₃COONa; the THz spectral intensity of the sample solutions decrease with increasing intensity of the applied magnetic field. Analysis shows that the magnetic field leads to a change in the dipole moment of water molecules in water and electrolyte solutions, which enhances not only the hydrogen-bond networking ability of water but also the hydration around ions in electrolyte solutions, increasing the number of hydrogen bonds. Increasing the intensity of this magnetic field further promotes the hydrogen-bond association between water molecules, weakening the THz transmission intensity of the solution.

• BMB Reports
• /
• v.29 no.6
• /
• pp.507-512
• /
• 1996

The NADPH oxidase of phagocytes catalyzes the reduction of oxygen to $O_{2}^{-}$ at the expense of NADPH The enzyme is dormant in resting neutrophils and hecomes activated on stimulation. During activation. $p47^{phox}$ (phagocyte oxidase factor), a cytosolic oxidase subunit, becomes extensively phosphorylated on a number of serines located between S303-S379. Although the biochemical role of phosphorylation is speculative, it has been suggested that phosphorylation could neutralize the strongly cationic C-terminal which may result in the change of conformation of $p47^{phox}$ and subsequent translocation of this protein and other cytosolic components to the membrane. In order to mimic the effect of phosphorylation in terms of neutralizing the positive charges, recombinant $p47^{phox}$ was treated with phenylglyoxal, which removes positive charges of arginine residues. Modification of recombinant $p47^{phox}$ resulted in the activation of oxidase in a cell-free translocation system as well as a conformational change in recombinant $p47^{phox}$ which may be responsible for the activation of the enzyme.