• 한국발생생물학회지:발생과생식
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• 제20권3호
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• pp.267-274
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• 2016

Cichlid fish species exhibit characteristic sexual behaviors according to not only reproductive stages but also social status. In a reproductive season, Astatotilapia burtoni males compete for females and a small number of dominant winners finally obtain the chance of spermiation. In addition to the characteristic behaviors, the dominant males have relatively bigger gonadotropin-releasing hormone 1 (GnRH1) neurons in the preoptic area (POA) of brain compared to those of subordinate males. Although the stimulatory effect of GnRH1 in vertebrate reproduction is well established, little is known about the triggering signal pathway to control GnRH1 neurons and GnRH1-mediated sexual behavior. In the present study, we evaluated the potential effect of TOR inhibitor rapamycin in relation to the cichlid male behaviors and GnRH1 neuron. After 14 h and 26 h of intraventricular injection of rapamycin, behavior patterns of chasing and courtship display did not show significant changes between rapamycin- and DMSO-injected males. Behaviors of spawning site entry increased in rapamycin-injected fish at 26 h post-injection than at 14 h post-injection significantly (P<0.05). Meanwhile, there was a tendency that GnRH1 neurons' soma size in the POA shrank by rapamycin injection, whereas the testes did not show notable changes. Taken together, these results suggest the possible role of TOR signal on GnRH1-mediated sexual behavior in cichlid dominant males, although further biological characterization of the TOR signaling pathway will be required to clarify this matter.

• Parasites, Hosts and Diseases
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• 제22권1호
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• pp.66-71
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• 1984

만손열두조충(Spirometra erinacei)의 성충에 의한 인체감염 2예가 투약후 충체를 수집함으로써 확인되었다. 환자는 강원도 산간지방에 거주하는 24세 및 21세 남자로 복통 및 상복부 통증이 있다고 하였으며 대변에서는 크기 $53-59{\times}37-42{\mu}m$의 조충류 충란이 발견되었다. 치료를 위해 atabrine 500mg과 하제를 투여한 바 3~4시간후 설사편으로부터 조충류 편절이 다수 수집되었다. 수집된 충체는 광선형 여관, 융구(vaginal opening)가 음경낭(cirrus sac)으로부터 분리되어 개구된 점, 저정낭(seminal vesicle)이 음경낭내로 포합된 점, 편절의 이음새부위에도 고환이 분포하는 점, 충란이 길고 한쪽 끝이 뾰족한 경향이 있으며 비대칭형인 점 등으로 Spirometra erinacei(Rudolphi, 1819)로 동정하였다. 환자는 모두 뱀을 날로 먹은 경험이 있으며 따라서 뱀이 감염원이었을 것으로 추측된다.

• 한국수산과학회지
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• 제13권4호
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• pp.173-178
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• 1980

1980년 1월부터 동반 10월까지 군산 근교 미면 내초도에서 채집한 백합Meretrix lusoria, 바지락 Tapes japonica, 맞조개 Seten strictus을 조사하여 흡충류의 유충인 Bacciger harengulae의 cercaria의 높은 기생율을 보았다. 이 cercaria는 S자형으로 활발히 운동한다. 꼬리에는 양쪽에 27쌍의 강모(seta)을 가지며, 1개의 강모(setae)는 6개의 가락(조)으로 되어 있다. 체내에는 구흡반, 맹장, 흡복반과 2개의 정소가 뚜렷히 보이고, 큰 V자형의 관상 배설낭내에는 작고 큰 과립이 충만되고, 염세포식은 2[(3+3)+(3+3)]=24이다. 현재까지 보고된 유사한 ceraria를 비교하니 Cercaria pectinata와 같았다. 제2중간숙주를 거쳐 결숙주에 성충을 얻었으므로, Bacciger harengulae의 cercaria라 동정하였다. 내초도에서 채집한 패류중 맛조개, 바지락, 백합의 순으로 이 기생법의 기생률이 높았으나, 이들 조개류는 모두 2-3년생인큰 것이 많이 기생되어 있었다.

• Parasites, Hosts and Diseases
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• 제51권2호
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• pp.191-196
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• 2013

The echinostome metacercariae encysted in Cipangopaludina sp. snails that were purchased from a market in Vientiane Municipality, Lao PDR, were identified as Echinostoma macrorchis (Digenea: Echinostomatidae) through recovery of adult flukes after experimental infection to rats and a cat. The metacercariae were round, $113-128(121){\times}113-125(120){\mu}m$, having a thick cyst wall, a head collar armed with collar spines, and excretory granules. The adult flukes recovered from the rats and cat at day 14 and 30 post-infection, respectively, were elongated, ventrally curved, and $3.9-6.3{\times}0.7-1.1mm$ in size. The head collar was distinct, bearing 43-45 collar spines with 5 angle spines on each side. Two testes were large (as the name implies), tandem, and slightly constricted at the middle, with irregular margins. Eggs were operculated, ovoid to elliptical, and $88-95{\times}56-60{\mu}m$. In scanning electron microscopy, the head collar was prominent, with 43-45 collar spines. Scale-like tegumental spines were densely distributed on the ventral surface between the oral and ventral suckers. Sensory papillae were distributed mainly on the tegument around the 2 suckers. It is confirmed that E. macrorchis is distributed in Lao PDR using Cipangopaludina sp. snails as the second intermediate host.

• Applied Microscopy
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• 제41권3호
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• pp.179-188
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• 2011

성숙한 2년산 미꾸라지(Misgurnus mizolepis) 친어로부터 3배체를 유도하여 이들 3배체의 정자형성과정에 따른 생식세포의 미세구조를 조사하여 2배체 숫컷과 비교하였다. 3배체 숫컷의 정자형성과정과 세포학적 미세구조는 2배체와 유사한 특징을 나타내었다. 정자변태과정이 일어나는 시기에 3배체의 정소 소엽내 Sertoli cell은 세포질 내 다수의 미토콘드리아 로제트, 소포체, 그리고 소량의 지방적 등을 함유하는 등 높은 활성을 나타내었다. 3배체 숫컷의 정소에서 일부 성숙한 정자들이 식별되었다. 변태를 완료한 3배체의 정자는 두부, 중편 그리고 미부축사로 구성되어 2배체 정자와 같은 anacrosomal aquasperm으로 나타났으나 생식세포 발달단계별 핵의 크기가 2배체보다 크고, 정자를 구성하는 cytoplasmic cannal의 직경이 크며 cytoplasmic collar의길이가 길고 미부축사의 직경이 굵고 두 개 이상의 미부축사를 가지는 등 비정상적인 구조를 나타내었다.

• Clinical and Experimental Pediatrics
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• 제54권3호
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• pp.137-140
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• 2011

Testicular adrenal rest tumors (TARTs) are considered to be formed from aberrant adrenal tissue that has become hyperplastic because of elevated adrenocorticotropic hormone (ACTH) in male patients with congenital adrenal hyperplasia (CAH). A 6-year-old boy presented with testicular enlargement and pubic hair. He was diagnosed with CAH complicated by precocious puberty. However, he was not followed-up. At the age of 17, he visited the outpatient clinic because of testicular enlargement and short stature. His right and left testicles were $10{\times}6$ cm and $7.5{\times}4.5$ cm, respectively. His height was 155.1 cm (standard deviation score (SDS), -2.90). The diagnosis of CAH due to 21 hydroxylase deficiency was confirmed by mutation analysis of CYP21A2. Histological examination of the testes showed large, polygonal, eosinophilic cells with round nuclei and prominent nucleoli, which were suggestive of TARTs. He was treated with dexamethasone for 3 weeks and tumors regressed. Subsequently, dexamethasone was replaced by prednisolone and $9{\alpha}$-fludrocortisone; thereafter, the reduced testis size has been maintained.

• 한국세라믹학회지
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• 제56권3호
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• pp.211-232
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• 2019

Porous ceramics are promising materials for a number of functional and structural applications that include thermal insulation, filters, bio-scaffolds for tissue engineering, and preforms for composite fabrication. These applications take advantage of the special characteristics of porous ceramics, such as low thermal mass, low thermal conductivity, high surface area, controlled permeability, and low density. In this review, we emphasize the direct foaming method, a simple and versatile approach that allows the fabrication of porous ceramics with tailored microstructure, along with distinctive properties. The wet foam stability is achieved under the controlled addition of amphiphiles to the colloidal suspension, which induce in situ hydrophobization, allowing the wet foam to resist coarsening and Ostwald ripening upon drying and sintering. Different components, like contact angle, adsorption free energy, air content, bubble size, and Laplace pressure, play vital roles in the stabilization of the particle stabilized wet foam to the porous ceramics. The mechanical behavior of the load-displacements curves of sintered samples was investigated using Herzian indentations testes. From the collected results, we found that microporous structures with pore sizes from 30 ㎛ to 570 ㎛ and the porosity within the range from 70% to 85%.

• 수산해양기술연구
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• 제54권4호
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• pp.279-286
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• 2018

The objective of this study was to quantitatively evaluate the influence of the netting hanging ratio on fishing performance of gillnet. A total of six tests was carried out using three kinds of gillnets with different horizontal hanging ratios (0.3, 0.5 and 0.7) on the basis commercial gillnet of mesh size of 60 mm used in Yeosu Dolsan. As a result of the test fishing operation, catches of the net with hanging ratio 0.3 and the shortest float length was 1.34 times larger than the net with hanging ratio 0.7. The caught species in experimental testes was lager in the net with hanging ratio 0.3 than the net with hanging ratio 0.7. The catch rate per unit area (CPUE) is on the silver croaker with the largest catches in tests as follows. The net with hanging ratio 0.3 net was $89.45g/m^2$, hanging ratio 0.5 net was $41.63g/m^2$, and hanging ratio 0.7 net was $24.50g/m^2$. The net with hanging ratio 0.3 (float line length of 45 m) exhibited the largest CPUE value.

• Parasites, Hosts and Diseases
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• 제59권3호
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• pp.303-309
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• 2021

In this study, we intended to describe an unrecorded species of heterophyid trematode recovered from the small intestine of a Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. A total of 13 small flukes were collected from a deceased Korean raccoon dog which was found in Chuncheon-si, Gangwon-do, Korea in May 2017. The trematode body were covered with many small spines, rectangular, broader than long, 807-1,103 ㎛ long and 1,270-1,550 ㎛ wide. Oral sucker in the anterior end slightly smaller than acetabulum. Pharynx muscular and well developed. Esophagus relatively long and sigmoid. Acetabulum small and located at median in anterior 2/5 portion. Ceca bifurcated at the anterior of genital pore and acetabulum and terminated at testis level. Testes larger, deeply lobed and located at the near of posterior end of body. Ovary small, triangular and located at the slight left of median and the anterior of left testis. Vitelline follicles dendritic and extend from the middle level of esophagus to the posterior portion of body. Eggs embryonated, operculated, small and 33-35×15-16 ㎛ in size. Based on the morphological characteristics, the small heterophyid flukes recovered from the small intestines of Korean raccoon dog, N. procyonoides koreensis, were identified as Euryhelmis squamula (Digenea: Heterophyidae). Accordingly, this species of heterophyid flukes is to be a new trematode fauna in Korea by this study.

• Clinical and Experimental Reproductive Medicine
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• 제49권1호
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• pp.9-15
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• 2022

The angiotensin-converting enzyme 2 receptor (ACE2) appears to be widely expressed in cells in the testes, predominantly in spermatogonia, Sertoli cells, and Leydig cells, and its co-expression with transmembrane protease serine 2 (TMPRSS2) is essential for the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). For this reason, the male reproductive system could be considered a potential target for SARS-CoV-2, as well as a possible reservoir of infection. However, to date, there is very little evidence about the presence of SARS-CoV-2 in semen and testicular samples. The aim of this paper was to review the current evidence regarding the impact of SARS-CoV-2 on male fertility and sexual health, with a particular focus on reproductive hormones, the presence of the virus in seminal fluid and testis, and its impact on fertility parameters. We found very limited evidence reporting the presence of SARS-CoV-2 in semen and testicular samples, and the impact of SARS-CoV-2 on reproductive hormones and fertility parameters is unclear. The quality of the examined studies was poor due to the small sample size and several selection biases, precluding definitive conclusions. Hence, future well-designed prospective studies are needed to assess the real impact of SARS-CoV-2 on male reproductive function.