Nowdays the application of immunohistochemical techniques and ultrastructuralanalysis and correlation with clinical and biochemical findings have led to a moredetailed functional classification,in which growth hormone...Nowdays the application of immunohistochemical techniques and ultrastructuralanalysis and correlation with clinical and biochemical findings have led to a moredetailed functional classification,in which growth hormone (GH)-producing andprolactin (PRL)-producing adenomas have been shown to comprise more than halfof pituitary adenomaso.Few immunoelectron microscopic studies on GH and PRLadenomas have been made,however,in limited cases so far,though a numberof authors have described the characteristics of pituitary adenomas by conventionalelectron microscopy.In addition to routine electron microscopy,immuno-.electron microscopical technique using protein A-gold probes was applied in展开更多
The localization of three monoclonal antibodies (MAb) against gastric cancer was studied on two human gastric cancer cell lines by immunoelectron microscopic technique. It has shown that the corresponding antigens of ...The localization of three monoclonal antibodies (MAb) against gastric cancer was studied on two human gastric cancer cell lines by immunoelectron microscopic technique. It has shown that the corresponding antigens of MAb 3G9 and 3H11 were distributed on the microvilli (M) and non-microvillus (NM) plasma membrane of target cells, with various M to NM ratios depending on the MAbs and target cells used. However, the corresponding antigens of MAb PD4 was only localized on the surface of round or finger-like bulges of target cells and never on the microvilli and non-microvillous plasma membrane. Since the nature and function of these tumor antigens have not been identified yet, the implication of the different distributions of these antigens remians to be clarifated.展开更多
Uncoupling protein 1 (UCP1) expressed by the brown adipose tissue (BAT) in the mitochondrial crista acts as a homeostatic thermogenerator of eutherians. The evaluation of UCP1 expression in the BAT offers significant ...Uncoupling protein 1 (UCP1) expressed by the brown adipose tissue (BAT) in the mitochondrial crista acts as a homeostatic thermogenerator of eutherians. The evaluation of UCP1 expression in the BAT offers significant scientific insight, especially in studies targeting limited areas such as the periarterial and pericardial regions of small experimental mammals. However, the negligible amount of this adipose tissue would render the general quantitative evaluation of the protein unreliable because of lipid contamination and low protein concentration. To address this problem, we quantitatively evaluated UCP1 expression in the mitochondrion of the mouse interscapular BAT using immunoelectron microscopy and immunohistochemical studies using a combination of primary and secondary antibodies in scheme A (rabbit anti-UCP1 IgG/gold particle-conjugated goat anti-rabbit IgG), B (rabbit IgG/gold particle-conjugated goat anti-rabbit IgG), C (rabbit anti-UCP1 IgG/gold particle-unconjugated goat anti-rabbit IgG), and D (rabbit IgG/gold particle-unconjugated goat anti-rabbit IgG). Scheme A shows the immunopositive reaction of obvious gold particles in the mitochondrial area, whereas other procedures revealed less distinctive reactions. The distinctive gold particle immunoreaction comprised electrical high-density spots with a mean diameter of >5 nm. However, in scheme B, the electrical high-density spots were scattered outside the mitochondrion and were significantly smaller than 4 nm;schemes C and D demonstrated few immunoreactions. Logistic regression analysis between schemes A and B showed that the threshold diameter of the electrical high-density spots measuring >5 nm indicated a true positive immunoreaction to anti-UCP1 antibody specifically in the mitochondrial area. Minor statistical difference was observed in the primary anti-UCP1 antibody between polyclonal IgG and monoclonal antibodies. Therefore, immunoelectron microscopy might be useful for evaluating negligible protein expression in some limited areas, such as UCP1 expression in the BAT of small experimental animals.展开更多
Plaques of amyloid-β(Aβ)and neurofibrillary tangles are the main pathological characteristics of Alzheimer’s disease(AD).However,some older adult people with AD pathological hallmarks can retain cognitive function....Plaques of amyloid-β(Aβ)and neurofibrillary tangles are the main pathological characteristics of Alzheimer’s disease(AD).However,some older adult people with AD pathological hallmarks can retain cognitive function.Unraveling the factors that lead to this cognitive resilience to AD offers promising prospects for identifying new therapeutic targets.Our hypothesis focuses on the contribution of resilience to changes in excitatory synapses at the structural and molecular levels,which may underlie healthy cognitive performance in aged AD animals.Utilizing the Morris Water Maze test,we selected resilient(asymptomatic)and cognitively impaired aged Tg2576 mice.While the enzyme-linked immunosorbent assay showed similar levels of Aβ42 in both experimental groups,western blot analysis revealed differences in tau pathology in the pre-synaptic supernatant fraction.To further investigate the density of synapses in the hippocampus of 16-18 month-old Tg2576 mice,we employed stereological and electron microscopic methods.Our findings indicated a decrease in the density of excitatory synapses in the stratum radiatum of the hippocampal CA1 in cognitively impaired Tg2576 mice compared with age-matched resilient Tg2576 and non-transgenic controls.Intriguingly,through quantitative immunoelectron microscopy in the hippocampus of impaired and resilient Tg2576 transgenic AD mice,we uncovered differences in the subcellular localization of glutamate receptors.Specifically,the density of GluA1,GluA2/3,and mGlu5 in spines and dendritic shafts of CA1 pyramidal cells in impaired Tg2576 mice was significantly reduced compared with age-matched resilient Tg2576 and non-transgenic controls.Notably,the density of GluA2/3 in resilient Tg2576 mice was significantly increased in spines but not in dendritic shafts compared with impaired Tg2576 and non-transgenic mice.These subcellular findings strongly support the hypothesis that dendritic spine plasticity and synaptic machinery in the hippocampus play crucial roles in the mechanisms of cognitive resilience in Tg2576 mice.展开更多
Physarum polycephalum L., a naturally synchronized myxomycophyta, was demonstrated to contain a cyclin B1-like protein by Western blot and immunoelectron microscopy. The content and subcellular location of the protein...Physarum polycephalum L., a naturally synchronized myxomycophyta, was demonstrated to contain a cyclin B1-like protein by Western blot and immunoelectron microscopy. The content and subcellular location of the protein varied during the cell cycle. The cyclin B1-like protein was first detected in the plasmodia of S phase while it did not appear in the nuclei until late G2 phase. The content of the protein in both the plasmodia and nuclei rose gradually onwards, peaked at metaphase and disappeared abruptly at ana-telophase. The protein was found to be distributed in both the cytoplasm and nuclei in late G2 phase and metaphase. In nuclei, the protein was mainly located in the chromosomal and nucleolar areas. The results suggest that the cyclin B1-like protein of P. polycephalum begins to be synthesized at S phase, enters the nuclei at late G2 phase, accumulates in both cytoplasm and nuclei onwards and breaks down at ana-telophase. The results also suggest that the cyclin B1-like protein acts as a cytoplasmic-nuclear protein during certain phases of the cell cycle.展开更多
25 k D蛋白是一种新的与重症肌无力相关的蛋白质。为了检测该蛋白在人体不同组织中的表达并明确其在人骨骼肌中的亚细胞定位。本研究提取和纯化 2 5 k D蛋白 ,免疫小鼠制备了 2 5 k D蛋白的抗体 ;用免疫印迹方法验证了抗体的特异性并检...25 k D蛋白是一种新的与重症肌无力相关的蛋白质。为了检测该蛋白在人体不同组织中的表达并明确其在人骨骼肌中的亚细胞定位。本研究提取和纯化 2 5 k D蛋白 ,免疫小鼠制备了 2 5 k D蛋白的抗体 ;用免疫印迹方法验证了抗体的特异性并检测2 5 k D蛋白在成年人及胎儿 8种不同组织中的表达 ;用免疫组化和免疫电镜方法明确了 2 5 k D蛋白在骨骼肌中的细胞及亚细胞定位。结果显示 ,2 5 k D蛋白抗体只与肌肉匀浆样品中 2 5 k D蛋白特异性反应。在成年人及胎儿 8种不同组织中 ,2 5 k D蛋白只见于骨骼肌。免疫组化可见在肌膜下和横纹上有不均匀的免疫染色 ;免疫电镜显示在肌膜下有电子致密物沉积 ,肌丝中未见有电子致密物沉积。这些结果表明 :2 5 k D蛋白抗体具有很高的特异性 ,2 5 k D蛋白只表达于人骨骼肌中 ,其亚细胞定位在骨骼肌的肌膜下。展开更多
文摘Nowdays the application of immunohistochemical techniques and ultrastructuralanalysis and correlation with clinical and biochemical findings have led to a moredetailed functional classification,in which growth hormone (GH)-producing andprolactin (PRL)-producing adenomas have been shown to comprise more than halfof pituitary adenomaso.Few immunoelectron microscopic studies on GH and PRLadenomas have been made,however,in limited cases so far,though a numberof authors have described the characteristics of pituitary adenomas by conventionalelectron microscopy.In addition to routine electron microscopy,immuno-.electron microscopical technique using protein A-gold probes was applied in
文摘The localization of three monoclonal antibodies (MAb) against gastric cancer was studied on two human gastric cancer cell lines by immunoelectron microscopic technique. It has shown that the corresponding antigens of MAb 3G9 and 3H11 were distributed on the microvilli (M) and non-microvillus (NM) plasma membrane of target cells, with various M to NM ratios depending on the MAbs and target cells used. However, the corresponding antigens of MAb PD4 was only localized on the surface of round or finger-like bulges of target cells and never on the microvilli and non-microvillous plasma membrane. Since the nature and function of these tumor antigens have not been identified yet, the implication of the different distributions of these antigens remians to be clarifated.
文摘Uncoupling protein 1 (UCP1) expressed by the brown adipose tissue (BAT) in the mitochondrial crista acts as a homeostatic thermogenerator of eutherians. The evaluation of UCP1 expression in the BAT offers significant scientific insight, especially in studies targeting limited areas such as the periarterial and pericardial regions of small experimental mammals. However, the negligible amount of this adipose tissue would render the general quantitative evaluation of the protein unreliable because of lipid contamination and low protein concentration. To address this problem, we quantitatively evaluated UCP1 expression in the mitochondrion of the mouse interscapular BAT using immunoelectron microscopy and immunohistochemical studies using a combination of primary and secondary antibodies in scheme A (rabbit anti-UCP1 IgG/gold particle-conjugated goat anti-rabbit IgG), B (rabbit IgG/gold particle-conjugated goat anti-rabbit IgG), C (rabbit anti-UCP1 IgG/gold particle-unconjugated goat anti-rabbit IgG), and D (rabbit IgG/gold particle-unconjugated goat anti-rabbit IgG). Scheme A shows the immunopositive reaction of obvious gold particles in the mitochondrial area, whereas other procedures revealed less distinctive reactions. The distinctive gold particle immunoreaction comprised electrical high-density spots with a mean diameter of >5 nm. However, in scheme B, the electrical high-density spots were scattered outside the mitochondrion and were significantly smaller than 4 nm;schemes C and D demonstrated few immunoreactions. Logistic regression analysis between schemes A and B showed that the threshold diameter of the electrical high-density spots measuring >5 nm indicated a true positive immunoreaction to anti-UCP1 antibody specifically in the mitochondrial area. Minor statistical difference was observed in the primary anti-UCP1 antibody between polyclonal IgG and monoclonal antibodies. Therefore, immunoelectron microscopy might be useful for evaluating negligible protein expression in some limited areas, such as UCP1 expression in the BAT of small experimental animals.
基金supported by grant PID2021-125875OB-I00 funded by MCIN/AEI/10.13039/501100011033 and by"ERDF A way of making Europe"(to RL)supported by a grant from Junta de Comunidades de Castilla-La Mancha (SBPLY/21/180501/000064)+3 种基金Universidad de Castilla-La Mancha (2023-GRIN-34187)(to RL).Grant PID201 9-104921RB-I00/MCI/AEI/10.13039/501100011033 (to AGO)the Foundation for Applied Medical Research,the University of Navarra (Pamplona,Spain)for financial supporthe Asociación de Amigos of the University of Navarra for the grant (to SB)Margarita Salas fellowship from Ministerio de Universidades and Universidad de Castilla-La Mancha (to AMB)
文摘Plaques of amyloid-β(Aβ)and neurofibrillary tangles are the main pathological characteristics of Alzheimer’s disease(AD).However,some older adult people with AD pathological hallmarks can retain cognitive function.Unraveling the factors that lead to this cognitive resilience to AD offers promising prospects for identifying new therapeutic targets.Our hypothesis focuses on the contribution of resilience to changes in excitatory synapses at the structural and molecular levels,which may underlie healthy cognitive performance in aged AD animals.Utilizing the Morris Water Maze test,we selected resilient(asymptomatic)and cognitively impaired aged Tg2576 mice.While the enzyme-linked immunosorbent assay showed similar levels of Aβ42 in both experimental groups,western blot analysis revealed differences in tau pathology in the pre-synaptic supernatant fraction.To further investigate the density of synapses in the hippocampus of 16-18 month-old Tg2576 mice,we employed stereological and electron microscopic methods.Our findings indicated a decrease in the density of excitatory synapses in the stratum radiatum of the hippocampal CA1 in cognitively impaired Tg2576 mice compared with age-matched resilient Tg2576 and non-transgenic controls.Intriguingly,through quantitative immunoelectron microscopy in the hippocampus of impaired and resilient Tg2576 transgenic AD mice,we uncovered differences in the subcellular localization of glutamate receptors.Specifically,the density of GluA1,GluA2/3,and mGlu5 in spines and dendritic shafts of CA1 pyramidal cells in impaired Tg2576 mice was significantly reduced compared with age-matched resilient Tg2576 and non-transgenic controls.Notably,the density of GluA2/3 in resilient Tg2576 mice was significantly increased in spines but not in dendritic shafts compared with impaired Tg2576 and non-transgenic mice.These subcellular findings strongly support the hypothesis that dendritic spine plasticity and synaptic machinery in the hippocampus play crucial roles in the mechanisms of cognitive resilience in Tg2576 mice.
文摘Physarum polycephalum L., a naturally synchronized myxomycophyta, was demonstrated to contain a cyclin B1-like protein by Western blot and immunoelectron microscopy. The content and subcellular location of the protein varied during the cell cycle. The cyclin B1-like protein was first detected in the plasmodia of S phase while it did not appear in the nuclei until late G2 phase. The content of the protein in both the plasmodia and nuclei rose gradually onwards, peaked at metaphase and disappeared abruptly at ana-telophase. The protein was found to be distributed in both the cytoplasm and nuclei in late G2 phase and metaphase. In nuclei, the protein was mainly located in the chromosomal and nucleolar areas. The results suggest that the cyclin B1-like protein of P. polycephalum begins to be synthesized at S phase, enters the nuclei at late G2 phase, accumulates in both cytoplasm and nuclei onwards and breaks down at ana-telophase. The results also suggest that the cyclin B1-like protein acts as a cytoplasmic-nuclear protein during certain phases of the cell cycle.
文摘25 k D蛋白是一种新的与重症肌无力相关的蛋白质。为了检测该蛋白在人体不同组织中的表达并明确其在人骨骼肌中的亚细胞定位。本研究提取和纯化 2 5 k D蛋白 ,免疫小鼠制备了 2 5 k D蛋白的抗体 ;用免疫印迹方法验证了抗体的特异性并检测2 5 k D蛋白在成年人及胎儿 8种不同组织中的表达 ;用免疫组化和免疫电镜方法明确了 2 5 k D蛋白在骨骼肌中的细胞及亚细胞定位。结果显示 ,2 5 k D蛋白抗体只与肌肉匀浆样品中 2 5 k D蛋白特异性反应。在成年人及胎儿 8种不同组织中 ,2 5 k D蛋白只见于骨骼肌。免疫组化可见在肌膜下和横纹上有不均匀的免疫染色 ;免疫电镜显示在肌膜下有电子致密物沉积 ,肌丝中未见有电子致密物沉积。这些结果表明 :2 5 k D蛋白抗体具有很高的特异性 ,2 5 k D蛋白只表达于人骨骼肌中 ,其亚细胞定位在骨骼肌的肌膜下。
