• 제목/요약/키워드: Ultrastructural

검색결과 772건 처리시간 0.033초

Biochemical and Ultrastructural Trends in Proteolysis of the $\beta$-subunit of 7S Protein in the Cotyledons During Germination of Soybean Seeds

  • Krishnan, Hari B.
    • 한국작물학회지
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    • 제47권2호
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    • pp.85-94
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    • 2002
  • Antibodies raised against the purified p-subunit of $\beta$-conglycinin were used in immunohistochemical studies to monitor the pattern of $\beta$-conglycinin mobilization in the cotyledons during soybean [Glycine max (L.) Merr.] seed germination. Western blot analysis revealed that the break down of the $\beta$-subunit of $\beta$-conglycinin commenced as early as 2 days after seed imbibition (DAI). Concurrent with the degradation of the $\beta$-subunit of $\beta$-conglycinin, accumulation of 48, 28, and 26 kD proteolytic intermediates was observed from 2 to 6 DAI. Western blot analysis also revealed that the acidic subunit of glycinin was mobilized earlier than the basic subunit. The basic glycinin subunit was subjected to proteolysis within 2 DAI resulting in the appearance of an intermediate product approximately 2 kD smaller than the native basic glycinin subunit. In contrast to the major seed storage proteins, lipoxygenase was subjected to limited proteolysis and was detected even after 8 DAI. The first sign of $\beta$-conglycinin breakdown was observed near the vascular strands and proceeded from the vascular strands towards the epidermis. Protein A-gold localization studies using thin sections of soybean cotyledons and antibodies raised against the $\beta$-subunit of $\beta$-conglycinin revealed intense labeling over protein bodies. A pronounced decrease in the protein A-gold labeling intensity over protein bodies was observed at later stages of seed germination. The protein bodies, which were converted into a large central vacuole by 8 DAI, contained very little 7S protein as evidenced by sparse protein A-gold labeling in the vacuoles.

人工培養液에서 培養된 牛精子의 形態的 變化 (Morphological Changes of Bovine Epididymal Spermatozoa Incubated In Chemical Defined Medium)

  • 고대환;윤산현;엄기붕;이경광;정길생
    • 한국가축번식학회지
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    • 제15권1호
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    • pp.33-39
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    • 1991
  • 본 試驗은 caffeine을 함유한 人工 培養液에서 培養한 牛精巢上體 精子의 形態的 變化를 透過 電子顯微鏡으로 관찰하였다. 電子顯微鏡에서 관찰한 결과 채취 직후의 無培養 精子는 대부분(79.8%)에서 구조상의 變化없이 원형 그대로의 原形質膜을 유지하고 있었으나 5 mM의 caffeine을 함유한 BO培養液에 3시간 培養한 精子는 尖體의 구조상 4가지 形態로 분류되었다. 즉 無反應, 胞狀化, 尖體離脫 및 退行으로서 각각 29.4%, 45.6%, 17.8% 및 7.2%였다. 이러한 결과는 精子膜의 胞狀化가 정상적인 尖體反應이며 尖體離脫 精子는 死滅精子라는 것과 caffeine이 牛精巢上體 精子의 尖體反應을 誘起시킬 수 있다는 것을 示唆하고 있다.

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Role of Gap Junctions in the Endothelium-Dependent Hyperpolarization of Vascular Smooth Muscle Cells

  • Yamamoto, Yoshimichi;Klemm, Megan F.;Hashitani, Hikaru;Lang, Richard J.;Soji, Tsuyoshi;Suzuki, Hikaru
    • The Korean Journal of Physiology and Pharmacology
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    • 제5권1호
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    • pp.1-8
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    • 2001
  • Hyperpolarization of arterial smooth muscle by acetylcholine is considered to be produced by the release of an unidentified chemical substance, an endothelium-derived hyperpolarizing factor (EDHF). Several chemicals have been proposed as the candidate for EDHF. However, none of them fulfil completely the nature and property of EDHF. Ultrastructural observation with electron microscope reveals that in some arteries, gap junctions are formed between endothelial and smooth muscle cells. In small arterioles, injection of gap junction permeable dyes into an endothelial cell results in a distribution of the dye to surrounding cells including smooth muscle cells. These observations allow the speculation that myoendothelial gap junctions may have a functional significance. Simultaneous measurement of the electrical responses in both endothelial and smooth muscle cells using the double patch clamp method demonstrates that these two cell types are indeed electrically coupled, indicating that they behave as a functional syncytium. The EDHF-induced hyperpolarization is produced by an activation of $Ca^{2+}-sensitive\;K^+-channels$ that are inhibited by charybdotoxin and apamin. Agonists that release EDHF increase $[Ca^{2+}]_i$ in endothelial cells but not in smooth muscle cells. Inhibition of gap junctions with chemical agents abolishes the agonist-induced hyperpolarization in smooth muscle cells but not in endothelial cells. All these observations can be explained if EDHF is an electrotonic signal propagating from endothelium to smooth muscle cells through gap junctions.

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Oxygen/Glucose Deprivation and Reperfusion Cause Modifications of Postsynaptic Morphology and Activity in the CA3 Area of Organotypic Hippocampal Slice Cultures

  • Jung, Yeon Joo;Suh, Eun Cheng;Lee, Kyung Eun
    • The Korean Journal of Physiology and Pharmacology
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    • 제16권6호
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    • pp.423-429
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    • 2012
  • Brain ischemia leads to overstimulation of N-methyl-D-aspartate (NMDA) receptors, referred as excitotoxicity, which mediates neuronal cell death. However, less attention has been paid to changes in synaptic activity and morphology that could have an important impact on cell function and survival following ischemic insult. In this study, we investigated the effects of reperfusion after oxygen/glucose deprivation (OGD) not only upon neuronal cell death, but also on ultrastructural and biochemical characteristics of postsynaptic density (PSD) protein, in the stratum lucidum of the CA3 area in organotypic hippocampal slice cultures. After OGD/reperfusion, neurons were found to be damaged; the organelles such as mitochondria, endoplasmic reticulum, dendrites, and synaptic terminals were swollen; and the PSD became thicker and irregular. Ethanolic phosphotungstic acid staining showed that the density of PSD was significantly decreased, and the thickness and length of the PSD were significantly increased in the OGD/reperfusion group compared to the control. The levels of PSD proteins, including PSD-95, NMDA receptor 1, NMDA receptor 2B, and calcium/calmodulin-dependent protein kinase II, were significantly decreased following OGD/reperfusion. These results suggest that OGD/reperfusion induces significant modifications to PSDs in the CA3 area of organotypic hippocampal slice cultures, both morphologically and biochemically, and this may contribute to neuronal cell death and synaptic dysfunction after OGD/reperfusion.

Alterations in Growth and Morphology of Ganoderma lucidum and Volvariella volvaceae in Response to Nanoparticle Supplementation

  • Singh, Swarnjeet;Kuca, Kamil;Kalia, Anu
    • Mycobiology
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    • 제48권5호
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    • pp.383-391
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    • 2020
  • Use of nanoparticles (NPs) in several commercial products has led to emergence of novel contaminants of air, soil and water bodies. The NPs may exhibit greater ecotoxicity due to nano-scale dependent properties over their bulk counterparts. The present investigation explores the effect of in vitro supplementation of TiO2, silica and silver NPs on radial growth and ultrastructural changes in the hyphae and spores of two mushroom genera, Ganoderma lucidum and Volvariella volvaceae. A concentration dependent decrease in radial growth on NP amended potato dextrose agar medium was recorded. However, in comparison to control, there was decrease in radial diameter on supplementation with TiO2 NPs while an increase was recorded for silica and silver NPs amendments as compared to their bulk salts at same concentrations after 48 h of incubation. Optical microscopy studies showed decrease in the number of spores while increase in spore diameter and thinning of hyphal diameter on NPs supplementation. Scanning electron microscopy analysis of fungal growth showed presence of deflated and oblong spores in two fruiting strains of Ganoderma while Volvariella exhibited decreased sporulation. Further, hyphal thinning and branching was recorded in response to NP amendments in both the test mushrooms. Enhancement of protein content was observed on NP compared to bulk supplementation for all cultures, concentrations and hours of incubation except for TiO2 NPs. Likewise, bulk and NP supplementations (at 100 mg L-1) resulted in enhanced laccase activity with occurrence of laccase specific protein bands on SDS-PAGE analysis.

고압맥동전류 자극이 흰쥐의 탈신경근 섬유 형태에 미치는 영향 (Effects of High Voltage Pulsed Galvanic Stimulation on Skeletal Muscle in Rats)

  • 박환진
    • The Journal of Korean Physical Therapy
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    • 제14권2호
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    • pp.145-152
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    • 2002
  • 고압맥동전류가 탈신경근의 형태에 미치는 영향을 알아보기 위하여 조직화학적 방법과 투과전자현미경적 관찰을 하였다. 웅성 흰쥐를 정상군, 탈신경군으로 각각 8마리씩 나누어 2주와 4주 후에 희생시켜 실험한 결과 다음과 같은 결과를 얻었다. 1. 조직화학적으로 형태를 관찰 한 결과 대조 1주군부터 근속과 근섬유사이에 염증세포가 관찰되고 핵이 근섬유속에 위치하는 것도 자주 관찰되었다. 2. 대조군도 비슷한 양상을 보였으나 4주군은 근괴사와 염증세포가 더욱 증가하였다. 3. 당원 1주군에서 실험군, 대조군 모두 정상근과 비슷한 양상을 보이나 4주군에서는 섬유를 구별할 수 없는 형태로 관찰되었다. 4. NADH-TR반응에서 적색섬유가 2주군에서 약간 증가하였고 그 후로는 구별이 불가능하였다. 5. 미세구조적으로 양쪽군 모두 근섬유가 굽어있고 mitochondria의 파괴로 인한 공포가 많이 관찰되었으나 전기자극 2주군에서는 일부에서 mitochondria증가를 관찰 하였다.

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대동맥 차단시 저온 산소화 심정지액이 심근보호에 미치는 영향 (An Experimental Study on the Effect of Hypothermic Oxygenated Cardioplegic Solution on Myocardial Protection during Prolonged Aortic Cross-clamping)

  • 왕영필;이홍균
    • Journal of Chest Surgery
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    • 제18권4호
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    • pp.759-770
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    • 1985
  • This study was experimentally undertaken to evaluate the effect of hypothermic oxygenated cardioplegic solution on myocardial protection during prolonged aortic cross clamping under cardiopulmonary bypass. Dogs were divided into two groups control group [received hypothermic unoxygenated cardioplegic solution] and experimental group [received hypothermic oxygenated cardioplegic solution]. Coronary sinus effluent was obtained at once and 30, 60, 90 minutes after cross-clamping for the determination of pH, PCO2,PO2 and lactate level during the infusion of cardioplegic solution and myocardial biopsies were obtained after cessation of 90 minutes of aortic cross-clamping. The results obtained were as follows: 1. There was no significant differences in the pH and PCO2 between the oxygenated and unoxygenated cardioplegic solution but the PO2 of the oxygenated solution was 4 times greater than unoxygenated solution, and also the oxygenated solution had a significantly greater oxygen content [2.020.05 ml 02/min] and had much more oxygen delivery than unoxygenated solution. 2. The myocardial oxygen consumption and the myocardial oxygen extraction in oxygenated group were 1.63 ml 02/100 ml and 67.32% respectively, which was greater than those in unoxygenated group. 3. Regarding to pH and PCO2 of coronary sinus effluent, there was no significant differences between two groups in early period of infusion of cardioplegic solution, but the pH shifted to acidosis from 60 minutes, PCO2 increased from 90 minutes of aortic cross-clamping, and PO2 markedly decreased from 90 minutes of aortic cross-clamping in unoxygenated group. 4. The lactate concentration of coronary sinus effluent revealed relatively normal in both groups, but showed slight increase up to 27.54.56 mg/100 ml at 90 minutes of aortic cross-clamping in unoxygenated group. 5. On electron microscopic study, the ultrastructural integrity of myocardial cells in oxygenated group was well preserved within 90 minutes. Slight swelling and deformity of mitochondria, interfibrillar widening, and disarrangement of myofibrils were observed at 90 minutes after aortic cross-clamping in unoxygenated group. From these results, the use of hypothermic oxygenated cardioplegic solution seemed to be effective and better method for the preservation of ischemic myocardium during the prolonged aortic cross-clamping.

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편측신절제 흰쥐에서 Cyclosporin A-유발 신독성에 대한 Verapamil의 효과 (Effects of Verapamil on Cyclosporin A-induced Nephrotoxicity in Uninephrectomized Rat)

  • 강주섭;고현철;이창호;신인철
    • Biomolecules & Therapeutics
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    • 제6권2호
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    • pp.130-138
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    • 1998
  • In this study, the effect of verapamil (VER) on cyclosporin A (CsA)-induced nephrotoxicity was investigated in uninephrectomized rats. Male Wistar rats were administered CsA (50 mg/kg/day, p.o.) or VER (0.5 mg/kg/day, i.p.) with CsA (50 mg/kg/day, p.o.) for 20 days. The urinary N-acetyl-$\beta$-D-glucosaminidase (NAG) activity along with BUN, serum creatinine, creatinine clearance (CLcr), body weight, and 24 hr-urine output were measured and histopathologic changes of kidney were evaluated by light and electron microscopy. The results obtained from this study can be summarized as follows: While NAG activity, BUN and serum creatinine was progressively increased and CLcr significantly decreased in CsA group, VER almost signifi-cantly (p<0.05) suppressed and normalized CsA-induced changes in VER+CSA group. While urine output increased until 12th days and thereafter progressively decreased in CsA group, it gradually increased in control and VER+CSA group. While body weight progressively made a gain in control and VER+CSA groups, it significantly (p<0.05) lost in CsA group. On light microscopy, the glomerular hyperemia and proximal convoluted tubular (PCT) dilatation, focal tubular cell vacuolation and necrosis were clearly evident in CsA group, but, were not seen in other groups. Ultrastructural studies revealed thickened glomerular endothelium and basal lamina of capillary, irregular shaped pedicels of podocytes, indistinct slit pores and narrowed bowman's space. The large oval vacuoles with dense debris and phagosome were distributed in apical zone and deformed microvilli and mitochondria were seen in the PCT cell of CsA group. But, glomeruli and PCT cell were relatively preserved in normal apperance in other groups. In conclusion, it is suggested that verapamil has a protective effect on cyclosporine-induced nephrotoxicity in uninephrectomized rats.

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A Novel Homozygous LIPA Mutation in a Korean Child with Lysosomal Acid Lipase Deficiency

  • Kim, Kwang Yeon;Kim, Ju Whi;Lee, Kyung Jae;Park, Eunhyang;Kang, Gyeong Hoon;Choi, Young Hun;Kim, Woo Sun;Ko, Jung Min;Moon, Jin Soo;Ko, Jae Sung
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제20권4호
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    • pp.263-267
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    • 2017
  • Patients with lysosomal acid lipase (LAL) deficiency and glycogen storage disease (GSD) demonstrated hepatomegaly and dyslipidemia. In our case, a 6-year-old boy presented with hepatosplenomegaly. At 3 years of age, GSD had been diagnosed by liver biopsy at another hospital. He showed elevated serum liver enzymes and dyslipidemia. Liver biopsy revealed diffuse microvesicular fatty changes in hepatocytes, septal fibrosis and foamy macrophages. Ultrastructural examination demonstrated numerous lysosomes that contained lipid material and intracytoplasmic cholesterol clefts. A dried blood spot test revealed markedly decreased activity of LAL. LIPA gene sequencing identified the presence of a novel homozygous mutation (p.Thr177Ile). The patient's elevated liver enzymes and dyslipidemia improved with enzyme replacement therapy. This is the first report of a Korean child with LAL deficiency, and our findings suggest that this condition should be considered in the differential diagnosis of children with hepatosplenomegaly and dyslipidemia.

Polyphasic delimitation of a filamentous marine genus, Capillus gen. nov. (Cyanobacteria, Oscillatoriaceae) with the description of two Brazilian species

  • Caires, Taiara A.;Lyra, Goia de M.;Hentschke, Guilherme S.;da Silva, Aaron Matheus S.;de Araujo, Valter L.;Sant'Anna, Celia L.;Nunes, Jose Marcos de C.
    • ALGAE
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    • 제33권4호
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    • pp.291-304
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    • 2018
  • Lyngbya C. Agardh ex Gomont is a nonheterocytous cyanobacterial genus whose evolutionary history is still poorly known. The traditionally defined Lyngbya has been demonstrated to be polyphyletic, including at least five distinct clades, some of which have been proposed as new genera. Intraspecific diversity is also clearly underestimated in Lyngbya due to the lack of unique morphological characters to differentiate species. In this study, we describe the new genus Capillus T. A. Caires, C. L. Sant'Anna et J. M. C. Nunes from benthic marine environments, including two new Brazilian species (here described as C. salinus T. A. Caires, C. L. Sant'Anna et J. M. C. Nunes, and C. tropicalis T. A. Caires, C. L. Sant'Anna et J. M. C. Nunes), and two species yet to be described, one of them from India (Capillus sp. 2.1), and the other from United States of America, based on strain PCC 7419. Capillus species presented cross-wise diagonal fragmentation, assisted or not by necridic cells, which has not been previously mentioned for Lyngbya. Ultrastructural analyses showed that C. salinus and C. tropicalis have numerous gas vesicles, which are rarely described for benthic marine species. The new genus formed a well-supported clade, and the D1-D1' and Box B secondary structures of internal transcribed spacer also supported the proposal of its new species. These findings help to clarify the diversity of species in the Lyngbya complex and the taxonomy of the group, and highlight the need of further floristic surveys in tropical coastal environments, which remain poorly studied.