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Featured researches published by Dong-Hyuk Jeong.


Dna Sequence | 2008

A comprehensive analysis of three Asiatic black bear mitochondrial genomes (subspecies ussuricus, formosanus and mupinensis), with emphasis on the complete mtDNA sequence of Ursus thibetanus ussuricus (Ursidae)

Dae-Sik Hwang; Jang-Seu Ki; Dong-Hyuk Jeong; Bo-Hyun Kim; Bae-Keun Lee; Sang-Hoon Han; Jae-Seong Lee

In the present paper, we describe the mitochondrial genome sequence of the Asiatic black bear (Ursus thibetanus ussuricus) with particular emphasis on the control region (CR), and compared with mitochondrial genomes on molecular relationships among the bears. The mitochondrial genome sequence of U. thibetanus ussuricus was 16,700 bp in size with mostly conserved structures (e.g. 13 protein-coding, two rRNA genes, 22 tRNA genes). The CR consisted of several typical conserved domains such as F, E, D, and C boxes, and a conserved sequence block. Nucleotide sequences and the repeated motifs in the CR were different among the bear species, and their copy numbers were also variable according to populations, even within F1 generations of U. thibetanus ussuricus. Comparative analyses showed that the CR D1 region was highly informative for the discrimination of the bear family. These findings suggest that nucleotide sequences of both repeated motifs and CR D1 in the bear family are good markers for species discriminations.


Journal of Veterinary Medical Science | 2017

Cardiorespiratory dose-response relationship of isoflurane in Cinereous vulture (Aegypius monachus) during spontaneous ventilation

Seong-Hoon Seok; Dong-Hyuk Jeong; Il-Hwa Hong; Hee-Chun Lee; Seong-Chan Yeon

Anesthesia is an inevitably important component of diagnosis and treatments examining the health condition of wild animals. Not only does anesthesia become an essential tool in minimizing stress of the patients and providing an opportunity to deliver accurate and safe procedures, but it also ensures the safety of the medical crew members. This study was conducted to investigate the dose-response cardiorespiratory effects of isoflurane during spontaneous ventilation in ten cinereous vultures. Each bird was administered isoflurane at initial concentration of 1.0, 1.5, 2.0, 2.5 and 3.0 and then an end-tidal isoflurane concentrations (ETiso) of 1.0% for an equilibration period of 15 min in the given order. At the end of the equilibration period, the direct blood pressure (BP), heart rate (HR), respiratory rate (RR) and end tidal CO2 partial pressure (PETCO2) were recorded, and blood gas analysis was performed. Increasing isoflurane concentrations during spontaneous ventilation led to dose-dependent increases in HR and PETCO2, with minimal changes in RR, decreased arterial BP and respiratory acidosis. Overall, isoflurane for anesthesia of spontaneously breathing cinereous vultures is a suitable choice for diagnostic or surgical procedures.


Journal of Veterinary Medical Science | 2017

Cardiorespiratory effects of isoflurane in Asiatic black bears (Ursus thibetanus) anesthetized with intramuscular medetomidine and zolazepam/tiletamine.

Dong-Hyuk Jeong; Jeong-Jin Yang; Seong-Hoon Seok; Dong-Joo Song; Seong-Chan Yeon

The objective of this study was to determine the dose-dependent effects of isoflurane on various cardiovascular parameters and the stable range of isoflurane concentrations in Asiatic black bears (Ursus thibetanus). Seven Asiatic black bears were intramuscularly injected with medetomidine, zolazepam and tiletamine (MZT) to induce anesthesia, and anesthesia was maintained by administering isoflurane in 100% oxygen (4 l/min) without mechanical ventilation. Several cardiovascular parameters were measured at five end-tidal isoflurane concentrations (0.5, 1.0, 1.5, 2.0, and 2.5%). Blood was collected from the femoral artery before administration of isoflurane and after each administration for immediate blood gas analysis. Isoflurane produced dose-dependent increases in heart rate, respiratory rate, minute volume, end-tidal carbon dioxide (CO2) partial pressure and the partial pressure of arterial CO2, and dose-dependent decreases in non-invasive blood pressure and tidal volume. Rectal temperature, oxygenation and acid-base balance were unaffected by isoflurane. All parameters in this study were in a clinically acceptable range at all times. The data show that the combination of MZT and isoflurane is suitable for general anesthesia in Asiatic black bears with spontaneous breathing during prolonged procedures. End-tidal isoflurane concentrations of 0.5 to 2.5% can be used in Asiatic black bears without adverse side effects.


Reproduction in Domestic Animals | 2015

Serial transrectal ultrasonography for monitoring the reproductive activity of the Asiatic black bear (Ursus thibetanus ussuricus).

Hyun Gu Kang; Dong-Hyuk Jeong; Jeong-Jin Yang; Bae-Keun Lee; Kong Jk; Lee Jw; Ill-Hwa Kim

This study evaluated the structural changes in the reproductive tract of Asiatic black bears using serial transrectal ultrasonography. In addition, the ultrasonographic observations were compared with the results of vaginal cytology and hormonal analyses. The collection of blood for hormonal analysis, vaginal cytology and transrectal ultrasonography was performed in two bears (Bears 1 and 2) from June 2011 to August 2013 without mating and in a third bear (Bear 3) from April to December 2012, allowing natural mating. Serial ultrasonographic observations showed cyclic changes in ovarian structures (e.g. emergence of small follicles, growth and ovulation of dominant follicles and corpus luteum (CL) formation) during the reproductive cycles of the three bears. The diameter of the uterine horns remained similar throughout the reproductive cycle in Bears 1 and 2, and it remained similar from April until October, but an enlargement containing foetuses was observed in Bear 3 in December. The ultrasonographic observations were consistent with the data obtained through vaginal cytology and progesterone analysis during the reproductive cycle. An average of 4.0 (±0.4) dominant follicles was observed during the oestrous stage (May-August), during which the superficial cells accounted for >90% of the total vaginal cells. In addition, the detection of an average of 2.6 (±0.2) CL was associated with increased plasma progesterone concentrations (3.0 ± 0.4 ng/ml) between June and December (near hibernation). In conclusion, serial transrectal ultrasonography demonstrated yearly oestrous (ovulation) cycles via follicular dynamics and CL formation on ovaries, accordingly with vaginal cytology and hormonal level in the Asiatic black bear.


Theriogenology | 2018

Characterization and cryopreservation of Amur leopard cats (Prionailurus bengalensis euptilurus) semen collected by urethral catheterization

Dong-Hyuk Jeong; Jeong-Ho Kim; Ki-Jeong Na

The Amur leopard cat (Prionailurus bengalensis euptilurus) is a globally endangered species, and there is thus an urgent need to increase its population. The objectives of this study were to: (1) confirm the utility of urethral catheterization (UC) for semen collection from Amur leopard cats; (2) investigate proper dilution media for fresh semen; and (3) investigate the effectiveness of sperm cryopreservation, including examining the effect of glycerol concentration. Six adult males in captivity (mean weight 5.03 ± 0.44 kg, aged 2-6 years) were included. All study procedures were performed during the breeding season (February to April) over two consecutive years. Semen samples (n = 28) were collected four or five times from each animal (four times for two animals and five times for four animals) by UC under general anaesthesia, and their characteristics (including sperm motility) were evaluated. First, the sperm motility in semen diluted in Hams F-10 or phosphate buffer saline (PBS) was compared. Next, semen diluted with TEST-yolk buffer containing 2%, 4%, or 6% glycerol was frozen in a liquid nitrogen tank, and sperm motility and acrosome integrity were evaluated after thawing. No difference in motility was observed between sperm diluted in Hams F-10 and PBS. The percentages of sperm motility and kinetic values in semen frozen in 2% or 4% glycerol were higher than those in semen stored in 6% glycerol. In conclusion, the UC method for semen collection is recommendable for Amur leopard cats and should be useful for artificial insemination. Although sperm motility decreased after thawing, samples thus preserved may be usable for advanced reproductive techniques, such as intracytoplasmic sperm injection or in-vitro fertilization.


Journal of Wildlife Diseases | 2018

Blood Chemistry Reference Values for Free-Ranging Asiatic Black Bears (Ursus thibetanus) by Season, Age, and Sex

Jeong-Jin Yang; Dong-Hyuk Jeong; Yoon-Kyu Lim

Abstract:  Physiological characteristics, such as blood chemistry values, are valuable for evaluating the health of the animals. To our knowledge, these values have never been reported for the free-ranging Asiatic black bear (Ursus thibetanus; ABB). Thus, 28 blood chemistry values from 50 free-ranging ABBs captured in Jirisan National Park, Republic of Korea, from 2005 to 2016 were evaluated. The aim of this study was to establish blood chemistry reference values for the free-ranging ABBs during both the hibernating and nonhibernating seasons. During hibernation, mean values of creatinine (CRE), total cholesterol, total protein (TP), albumin (ALB), triglycerides, and magnesium were significantly higher than those during nonhibernation; however, mean values of blood urea nitrogen, urea nitrogen to creatinine (U/C) ratio, inorganic phosphorous (IP), aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, lactate dehydrogenase (LDH), high-density lipoprotein cholesterol, and alkaline phosphatase (ALP) were significantly lower. Age differences (young vs. adult) were found in IP, LDH, TP, and ALB values during hibernation and in the U/C ratio, calcium, IP, ALP, creatine kinase myocardial band, CRE, total bilirubin, and uric acid values during nonhibernation. However, there were no sex differences (male vs. female).


Journal of Wildlife Diseases | 2017

Immobilization of Asiatic Black Bears (Ursus thibetanus) with Medetomidine-Zolazepam-Tiletamine in South Korea

Dong-Hyuk Jeong; Jeong-Jin Yang; Seong-Hoon Seok; Byeung-Cheul Song; Seong-Chan Yeon

Abstract The Asiatic black bear (Ursus thibetanus; ABB) is a globally endangered species for which a restoration program has been ongoing in South Korea since 2001. However, there is little information on immobilization protocols for ABBs. We evaluated the use of medetomidine-zolazepam-tiletamine for their immobilization. During 2005–13, we anesthetized 60 ABBs (32 males, 28 females; 7 mo to 12 yr old) with medetomidine 0.03–0.045 mg/kg and zolazepam-tiletamine 1.54–2.3 mg/kg; reversal of anesthesia was done with atipamezole 0.15–0.225 mg/kg administered intravenously alone or intravenously and intramuscularly (50:50). Mean (and SD) for physiologic collected for 373 immobilizations of at least 60 min were: time to sedation, 7.8 (5.4) min; anesthesia induction time, 13.7 (8.1) min; complete recovery time, 14.8 (12.4) min; respiratory rate, 14 (7) breaths/min; heart rate, 51 (16) beats/min; rectal temperature, 37.3 (1.3) C; and hemoglobin oxygen saturation, 88% (6%). Few cardiopulmonary side effects occurred during immobilization and adequate depth of anesthesia was maintained for >60 min without need for supplementation. The dosage and drug combination used was effective for immobilization of ABBs with minimal adverse effects on vital signs and can be recommended in most clinical applications.


Journal of Veterinary Medical Science | 2017

Prediction of arterial blood gas values from venous blood gas values in Asiatic black bears (Ursus thibetanus) anesthetized with intramuscular medetomidine and zolazepam-tiletamine

Dong-Hyuk Jeong; Jeong-Jin Yang; Lyon Lee; Seong-Chan Yeon

The objective of this study was to measure differences between arterial and venous blood gas parameters and to evaluate whether arterial blood gas values can be estimated from venous blood in Asiatic black bears (ABBs). Twelve healthy captive ABBs (8 males and 4 females; 8–16 years; 76.8–220 kg) were included in this study. The bears were immobilized with medetomidine and zolazepam-tiletamine using a dart gun. Arterial and venous samples were collected simultaneously at 5 and 35 min after recumbency (5- and 35-min points). Partial pressure of oxygen (PO2), partial pressure of carbon dioxide (PCO2), pH, bicarbonate (HCO3−), total carbon dioxide (TCO2), oxygen saturation of hemoglobin (SO2) and base excess (BEecf) were analyzed using a portable blood gas analyzer. There was no marked difference in measured and calculated variables over time in both venous and arterial blood except for PO2. However, arterial PO2, SO2 and pH were significantly higher and arterial PCO2, TCO2 and HCO3− were lower than those of venous samples at both 5- and 35-min points. In the regression analysis to estimate arterial values from venous values, PCO2, TCO2, HCO3−, BEecf and pH significantly showed over 0.45 in coefficient of determination value (R2), and there were little differences between actual and predicted arterial values. Although there were limits in venous gas values replaced those of arterial blood, if we could not get the arterial samples, the regression formulas for arterial values from venous blood in this study would be useful clinically, except for PO2 and SO2.


Mitochondrial DNA | 2008

A comprehensive analysis of three Asiatic black bear mitochondrial genomes (subspecies ussuricus, formosanus and mupinensis), with emphasis on the complete mtDNA sequence of Ursus thibetanus ussuricus (Ursidae).

Dae-Sik Hwang; Jang-Seu Ki; Dong-Hyuk Jeong; Kim Bh; Bo-Young Lee; Sung-Hwan Han; Jae-Seong Lee


Journal of Wildlife Management | 2015

Management implications for releasing orphaned, captive-reared bears back to the wild

John J. Beecham; Miguel de Gabriel Hernando; Alexandros A. Karamanlidis; Richard A. Beausoleil; Kelcey Burguess; Dong-Hyuk Jeong; Mathew Binks; Leonardo Bereczky; N. V. K. Ashraf; Kira Skripova; Lisa Rhodin; Janene Auger; Bae-Keun Lee

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Seong-Chan Yeon

Gyeongsang National University

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Seong-Hoon Seok

Gyeongsang National University

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Hee-Chun Lee

Gyeongsang National University

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Se-Jin Park

Gyeongsang National University

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Seung-Yong Lee

Gyeongsang National University

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Il-Hwa Hong

Gyeongsang National University

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