• Applied Microscopy
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• 제28권1호
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• pp.63-71
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• 1998

모샘치아과의 한국고유종인 긴몰개 (Squalidus gracilis majimae)의 정자는 구형의 두부와 짧은 중편 및 긴 편모를 가지고 있으며 그 길이는 $36.6{\mu}m$이었다. 두부에는 다른 경골어류에서와 같이 첨체를 가지고 있지 않으며 핵은 $1.9{\mu}m$의 직경을 가지고 핵막 주변부에는 전자밀도가 낮은 염색질 부위를 포함하고 있었다. 핵와는 다른 잉어류에서와 같이 핵막이 얕게 함입되어 기부중심립만을 포함하고 있어서, 메기류의 기부 및 말단부 중심립을 포함하는 긴 핵와와는 큰 차이를 보여주었다. 두 중심립은 서로 약 $140^{\circ}$의 각도로 배열되어 있었다. 미토콘드리아는 중편세포질에 3층으로 배열되어 있으나 축사를 둘러싸고 있지 않으며 축사와는 세포질관에 의해 분리되어 있었다. 정자의 꼬리에 대한 핵의 위치와 미토콘드리아의 비대칭적 배열은 잉어과 정자의 공통된 특징으로 나타나며, 미토콘드리아가 분포된 중편세포질은 다른 잉어류에서보다 훨씬 풍부하였다. 긴몰개의 정자는 현재까지 밝혀진 잉어과의 정자중에서 세포질관의 길이가 가장 길고, 미토콘드리아의 수도 가장 많이 나타났다. 편모에는 lateral fins가 관찰되지 않았다.

• Journal of Korean Neurosurgical Society
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• 제30권7호
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• pp.831-841
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• 2001

Objective : Somatosensory evoked potentials(SSEPs) have been used widely both experimentally and clinically to monitor the function of central nervous system and peripheral nervous system. Studies of SSEPs have reported the various recording techniques and patterns of SSEP. The previous SSEP studies used scalp recording electrodes, showed mean vector potentials which included relatively constant brainstem potentials(far-field potentials) and unstable thalamocortical pathway potentials(near-field potentials). Even in invasive SSEP recording methods, thalamocortical potentials were variable according to the kinds, depths, and distance of two electrodes. So they were regarded improper method for monitoring of upper level of brainstem. The present study was conducted to investigate the characteristics of somatosensory evoked field potentials(SSEFPs) of the cerebral cortex that evoked by hindlimb stimulation using ball electrode and the pathways of SSEFP by recording the potentials simultaneously in the cortex, VPL nucleus of thalamus, and nucleus gracilis. Methods : In the first experiment, a specially designed recording electrode was inserted into the cerebral cortex perpendicular to the cortical surface in order to recording the constant cortical field potentials and SSEFPs mapped from different areas of somatosensory cortex were analyzed. In the second experiment, SSEPs were recorded in the ipsilateral nucleus gracilis, the contralateral ventroposterolateral thalamic nucleus(VPL), and the cerebral cortex along the conduction pathway of somatosensory information. Results : In the first experiment, we could constantly obtain the SSEFPs in cerebral cortex following the transcutaneous electrical stimulation of the hind limb, and it revealed that the first large positive and following negative waves were largest at the 2mm posterior and 2mm lateral to the bregma in the contralateral somatosensory cortex. The second experiment showed that the SSEPs were conducted by way of posterior column somatosensory pathway and thalamocortical pathway and that specific patterns of the SSEPs were recorded from the nucleus gracilis, VPL, and cerebral cortex. Conclusion : The specially designed recording electrode was found to be very useful in recording the localized SSEFPs and the transcutaneous electrical stimulation using ball electrode was effective in evoking SSEPs. The characteristic shapes, latencies, and conduction velocities of each potentials are expected to be used the fundamental data for the future study of brain functions, including the hydrocephalus model, middle cerebral artery ischemia model, and so forth.

• 한국어병학회지
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• 제30권2호
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• pp.97-105
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• 2017

Parasitic leeches could directly (through causing poor growth, anemia and wound in the fish) and indirectly (by predisposition of the fish to secondary bacterial and fungal infections) affects their hosts. In the present study, fishes that were attacked by leeches in natural and experimental environment were studied. Pathologic samples were obtained from damages at the site of leech bite, as well as kidney and liver of the fish. Histopathological examination revealed numerous lesions at the site of leech bite including tissue demolition, detachment at the site of leech bite in the epidermis of epithelial tissue in the skin, destructed nucleus in epithelial cells of the skin plus necrosis in the damaged skin and weak inflammatory penetration to acute necrotic damages along with piercing dermis layer. Pathologic lesions in the kidney included some changes such as proliferation by increasing glomerular cells and membrane cells in capillary vein of the kidney, blood cell necrosis in kidney with infiltration of white blood cells mainly mononuclear and less polymorphonuclear which are the symptoms of anemia due to blood feeding and sucking by leeches. There was also a chronic kidney infection probably originated from another part of body such as skin. Moreover, leeches caused hemorrhagic anemia due to blood consumption of the hosts, which led to observation of immature red blood cells. Also results showed that diseases induced by leeched in fish could be acute or chronic, which depends on size of fish, species of leech and severity of infection.