• Korean Journal of Environmental Biology
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• v.17 no.3
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• pp.285-292
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• 1999

Di-(2-ethylhexyl) phthalate (DEHP) is a plasticizer known as one of endocrine disruptors. The present study was carried out to investigate the alterations of function and ultrastructure in rat testes after oral intubation of DEHP in dosages of 1g/kg/day, 2 g/kg/day or 3 g/kg/day in 0.5 ml of corn oil for 15 days. DEHP reduced the growth of body and testes, inhibited apermatogenesis and induced structural changes on various cell types of the rat testis. Leydig cells, Sertoli cells and the developing germ cells seemed to be impaired their differentiations in terms of the structural changes of cell organelles. The increase of heterochromatin in amount were common features in all 3 cell types. In addition, the Leydig cells were characterized by the swelling of smooth endoplasmic reticulum and perinuclear space, the increases in number and size of Iysosomes. The Sertoli cells became irregular in nuclear envelope and the number of Iysosomes and vacuoles seemed to be increased. There were some indications of necrosis of the germ cells, such as vacuolized nucleus and segregated nucleolus. And also, DEHP lowered the level of testosterone in experimental rat serum. DEHP suppressed apermatogenesis decreasing developing germ cells and these effects of DEHP on the rat testis were dose dependent. The detrimental effect of DEHP on apermatogenesis and ultrastructure of rat testes seems to be derived from the decreased level of testosterone by Leydig cells, followed by the abnomalities of Sertoli cells and the germ cells.

• Korean Journal of Environmental Biology
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• v.17 no.2
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• pp.129-138
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• 1999

Chlorinated aromatic compounds are one of the largest groups of environmental pollutants as a result of world-wide distribution by using them as herbicides, insecticides, fungicides, solvents, hydraulic and heat transfer fluids, plasticizers, and intermediates for chemical synthesis. Because of their toxicity, persistence, and bioaccumulation, the compounds contaminated ubiquitously in the biosphere has attracted public concerns in terms of serious influences to wild lives and a human being, such as carcinogenicity, mutagenicity, and disturbance in endocrine systems. The biological recalcitrance of the compounds is caused by the number, type, and position of the chlorine substituents as well as by their aromatic structures. In general, the carbon-halogen bonds increase the recalcitrance by increasing electronegativity of the substituent, so that the dechlorination of the compounds is focused as an important mechanism for biodegradation of chlorinated aromatics, along with the cleavage of aromatic rings. The removal of the chlorine substituents has been known as a key step for degradation of chlorinated aromatic compounds under aerobic condition. This can occur as an initial step via oxygenolytic, reductive, and hydrolytic mechanisms. The studies on the biochemistry and genetics about microbial dechlorination give us the potential informations for microbial degradation of xenobiotics contaminated in natural microcosms. Such investigations might provide biotechnological approaches to solve the environmental contamination, such as designing effective bioremediation systems using genetically engineered microorganisms.

• Applied Microscopy
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• v.29 no.3
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• pp.353-362
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• 1999

Di-(2-ethylhexyl) phthalate (DEHP) is a plasticize. known as one of endocrine disruptors. The present study was carried out to investigate the ultrastructural changes of prepubertal rat testis after oral administration of DEHP in dosages of 1 g/kg, 3 g/kg or 5g/kg in 0.5 ml of corn oil daily for a week. This study revealed the DEHP inhibited the development of seminiferous tubules and induced structural changes on various cell types of the rat testis. Leydig cells, Sertoli cells and the developing germ cells seemed to be impaired their differentiations in terms of the structural changes of cell organelles. The increase of heterochromatin in amount were common features in all 3 cell types. In addition, the Leydig cells were characterized by the increases in number and size of lysosomes and the scantiness of smooth endoplasmic reticulum. The Sertoli cells became irregular in nuclear envelope and the cytoplasm decreased, but the number of lysosomes and vacuoles seemed to be increased. There were some indications of necrosis of the germ cells, such as vacuolized nucleus and segregated nucleolus. These detrimental effects of DEHP on the rat testis were dose dependent and suppressed spermatogenesis decreasing developing germ cells in number and appearances. The effect of DEHP on ultrastructure of rat testis, as its known physiological functions, seems come from the decreased level of testosterone by Leydig cells, followed by the abnomalities of Sertoli cells and the germ cells.

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.103-112
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• 2011

Aquatic contamination by organic pollutants has been a suspected reason for rapid decrease of amphibian populations whose embryonic and larval stages are in an aquatic environment. Amphibian embryos can be a useful model to study the ecoctoxicologial impacts of aquatic pollutants. The obtained toxicological data are useful references for the management of aquatic pollutants in public health because amphibia share many developmental events with terrestrial vertebrates including humans. Safety guidelines for the toxicological effects of aquatic contaminants of chemicals identified as hazardous should be addressed at multiple endpoints. Alkylphenols have been widely-used in agricultural, industrial, and household activities; they contaminate and can persist in aquatic environments. Exposure to alkylphenols results in endocrine disruption in aquatic animals. In this review, we summarize the developmental toxicities of alkylphenols in amphibian embryos and larva according to the exposure route, chemical concentration, duration of exposure, and affected developmental stage together with mechanisms of toxicity and typical patterns of developmental abnormality. The merits of amphibian embryos as a toxicity test model for mid- to long-term exposure to aquatic pollutants are discussed proposed.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.266-271
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• 2007

Bisphenol A (BPA) has been widely used as a monomer for production of epoxy resins and polycarbonate plastics. The annual production of BPA exceeds 640,000 metric tons in worldwide. BPA, a suspected phenolic endocrine disrupter, is moderately soluble and frequently detected in industrial wastewater. To date, HPLC and GC has been used for BPA analysis. However, HPLC and GC-analysis need high operation lost, experts, and an elaborate pre-treatment of samples, and is difficult to apply on-time and mass analysis. Therefore, simple, mass and rapid detection of BPA in environments is necessary. In the present study, spectrophotometric method of BPA quantification was developed. Based on blue-color product formation with BPA and ferric chloride/ferricyanide under the optimized conditions, the standard curve was acquired $({\lambda}_{750}=0.061\;BPA\;[{\mu}M]+0.07155,\;R^2=0.992)$. Using an established method, the BPA contents in the soil extract, and different water samples and living products, including disposable syringe, cup and plastic tube, were analyzed. The results suggested that the method is useful for BPA determination from different massive samples. Since the BPA metabolites, nontoxic 4-hydroxyacetophenone or 4-hydroxybenzaldehyde, did not form blue-color product, this method is also useful to screen a microorganism for BPA bioremediation.

• Journal of Oral Medicine and Pain
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• v.42 no.1
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• pp.1-7
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• 2017

Purpose: The aims of this study were to evaluate the clinical characteristics and polysomnographic results of patients visited the Seoul National University Dental Hospital (SNUDH) and to suggest guidelines for the management of sleep disordered-breathing patients in a dental clinic. Methods: Five hundred sixty-two patients who visited the Snoring and Sleep Apnea Clinic of SNUDH were evaluated for clinical characteristics including associated comorbidities, age, gender, body mass index (BMI), neck circumference, and daytime sleepiness and among them 217 patients were performed nocturnal polysomnography for evaluating respiratory disturbance index, apnea-hypopnea index (AHI), oxygen saturation levels, and sleep stages. The associations among clinical characteristics, sleep parameters, and positional and rapid eye movement (REM) dependencies of the patients were analyzed. Results: The most common co-morbidities of the patients were cardiovascular (30.2%), endocrine (10.8%), and respiratory diseases (7.9%). Age (${\beta}=0.394$), total AHI (${\beta}=0.223$), and lowest $O_2$ saturation levels (${\beta}=0.205$) were significantly associated with the number of co-morbidities in patients with obstructive sleep apnea (OSA). Mean $O_2$ saturation was not significantly associated with number of co-morbidities. Non-positional OSA patients had higher BMI, longer neck circumferences, more severe AHI values, and lower mean and lowest $O_2$ saturation levels compared to positional OSA patients. Not-REM-related patients were older and had more severe AHI values compared to REM-related patients. Not-REM-related patients have longer duration of stage I sleep and shorter stage II, III, and REM sleep than REM-related patients. There were no significant differences in each sleep stage between positional and non-positional patients. Neck circumference, positional dependency, REM dependency, and percentage of supine position were significantly associated with severity of OSA. Conclusions: Age, total AHI, and lowest $O_2$ saturation level were significantly associated with the number of co-morbidities in patients with OSA. Neck circumference, positional dependency, REM dependency, and percentage of supine position were significantly associated with severity of OSA.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.1
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• pp.85-92
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• 2000

Common dental procedures(dental extraction & minor operation) are potentially stress-inducing in many patients, especially medically compromised patients. The body's response to dental stress involves the cardiovascular system(an increase in cardiovascular workload), the respiratory organ and the endocrine system(change in metabolism). To minimize the stress to the medical risk patient, the stress reduction protocol was established. The obtained contents were as follows: (1) Recognize the patient's degree of medical risk (2) Complete medical consultation before dental therapy (3) Schedule the patient's appointment in the morning (4) Monitor and record preoperative and postoperative vital signs (5) Use psychosedation during therapy (6) Use adequate pain control during therapy (7) Short length of appointment : do not exceed the patient's limits of tolerance (8) Follow up with postoperative pain/anxiety control (9) Telephone the higher medical risk patient later on the same day that treatment was given Though the stress reduction protocol above was applied to the dental extraction in medically compromised patients with the advanced infected teeth, the final responsibility for the complications(syncope, bleeding & infection, etc.) in a patient rests with the dentist who ultimately treats him. For the prevention of postextraction complications & poor prognosis, the authors treated the advanced infected teeth with the pulp extirpation, opening drainage through the canal and complete occlusal reduction. The final extraction and wound closure were then done after $1{\sim}2$ weeks. The final prognosis was comfortable without common complications.

• The Korean Journal of Nuclear Medicine
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• v.29 no.3
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• pp.319-327
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• 1995

$^{131}I$-metaiodobenzylguanidine(MIBG) has been used for the diagnosis and treatment of neural crest tumors. We report our experience with this agent in 8 patients[1 multiple endocrine neoplasia(MEN) type IIb; 2 malignant pheochromocytoma; 5 medullary thyroid carcinoma(MTC)]. The therapeutic procedure consisted of 30-200 mCi of $^{131}I-MIBG$ administered by slow I.V. infusion, given at 3-6 months intervals. Commutative activity ranged from 150 mCi to 410 mCi, in 1 to 4 courses. $^{131}I-MIBG$ therapy resulted in significant disease free interval in 1 malignant pheochromocytoma(no measurable lesion) after surgery; complete hormonal and tumoral response in 2 MTC(1 MEN IIb): stable disease in 1 recurred pheochromocytoma(MEN IIb): stable disease but symptomatic improvement in 1 MTC, progressive disease in 1 malignant pheochromocytoma and 2 MTC. The patients who showed progression appeared to have large inoperable tumors or postoperative remnant tumors.

• Journal of Ginseng Research
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• v.30 no.1
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• pp.8-14
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• 2006

This study was carried out to investigate the protective effect of crude saponin from red ginseng efflux (RGE-CS) on biochemical parameters in male rats acutely exposed to 2,3,7,8-tetrachlorodibenzo-$\rho$-dioxin (TCDD). Forty male rats ($200{\pm}20g$) were divided into 4 groups. Normal control group (NC) received vehicle and saline; only TCDD-treated group (TT) received TCDD ($5{\mu}g/kg$, single dose) intrperitoneally; RGE-CS 20 received 20 mg/kg of crude saponin i.p. for 4 weeks from 1 week before TCDD-exposure; RGE-CS 40 also received 40 mg/kg of crude saponin i.p. for 4 weeks from 1 week before TCDD-exposure. Body weight of TT group was significantly decreased after TCDD-exposure. However, body weight of crude saponin groups increased throughout the experimental period, although the increasing rate was slower than that of NC group. Decrease in body weight was not observed during the experimental period in RGE-CS 40. Increases in triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), AST, ALT and $Fe^{2+}$ levels by TCDD intoxication were significantly attenuated by the RGE-CS treatment. Decrease in glucose, amylase, lactate dehydrogenase (LDH) and creatinine kinase (CK) by TCDD also were inhibited by the RGE-CS. These results suggest that saponin from red-ginseng efflux might be a useful protective agent against TCDD, an endocrine disrupter.

• The Journal of Korean Physical Therapy
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• v.17 no.3
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• pp.329-338
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• 2005

The determination of peripheral nerve conduction velocity is an important part to electrodiagnosis. Its value as neurophysiologic investigative procedure has been known for many years but normal value of digital nerve was not reported in Korea. To evaluate of digital nerve conduction velocity of median nerve for obtain clinically useful reference value and compare difference in each fingers. 71 normal volunteers(age, 19-65 years; 142 hands) examined who has no history of peripheral neuropathy, diabetic mellitus, chronic renal failure, endocrine disorders, anti-cancer medicine, anti-tubercle medicine, alcoholism, trauma, radiculopathy. Nicolet Viking II was use for detected conduction velocity and amplitude of digital nerves in median nerve. Data analysis was performed using SPSS. Descriptive analysis was used for obtain mean and standard deviation, ANOVA was used to compare each fingers and independent t-test was used to compare between Rt and Lt side also compare between different in genders. Conduction velocity of the right thumb was 49.77m/sec, index finger was 56.80m/sec, middle finger was 56.15m/sec and ring finger was 53.38m/sec. The left thumb was 50.48m/sec, index finger was 56.76m/sec, middle finger was 55.99m/sec and ring finger was 53.23m/sec. Amplitude of the right thumb was $64.30{\mu}V$, index finger was $73.95{\mu}V$, middle finger was $77.97{\mu}V$ and ring finger was $43.92{\mu}V$. The left thumb was $74.21{\mu}V$, index finger was $85.72{\mu}V$, middle finger was $88.06{\mu}V$ and ring finger was $47.28{\mu}V$. There were significantly difference between thumb, index, middle and ring fingers(p<.01) but there were no statistically difference between conduction velocity and amplitude of index and middle fingers(p>.01). The conduction velocity of index finger are faster than other fingers and amplitude of middle finger are greater than other fingers. The present results revealed that electodiagnosis can easily perform in index and middle finger for digital nerve of median nerve study.