Electron microscopic radioautographic study of RNA synthesis in hepatocyte mitochondria of aging mouse

In order to study the aging changes of intramitochondrial RNA synthesis in mouse hepatocytes, 10 groups of aging mice, each consisting of three individuals (total 30) from fetal day 19 to postnatal month 24 were injected with 3H-uridine, an RNA precursor, sacrificed 1 hour later, and the liver tissues processed for electron microscopic radioautography. On EM radioautograms obtained from each animal the number of mitochondria, the number of labeled mitochondria, and the mitochondrial labeling index labeled with 3H-uridine showing RNA synthesis in each hepatocytes, both mononucleate and binucleate cells, were counted and the averages in respective aging groups were compared. From the results it was demonstrated that the numbers of mitochondria, the numbers of labeled mitochondria, and the labeling indices of intramitochondrial RNA syntheses in both mononucleate and binucleate hepatocytes of mice at various ages increased and decreased according to the age of the animals.     

5-HT 1A and 2A receptor positive cells in the cerebella of mice and human and their decline during aging

This study evaluated the 5-HT1A and 5-HT2A receptor positive cells in the cerebella of mice and human by immunocytochemistry. Mice were of ages 1, 3, and 12 months whereas the human subjects were divided into two groups, a younger 57–78 years old group and an older 82–91 years old group. Both 5-HT1A and 5-HT2A receptor positive cells were observed in the molecular and granular layers of the cerebella of mice and human. Although there was a decline in these positive cells during aging, no regional difference in the positive cells were observed in the anterior, middle, and posterior regions of the cerebella. Microsc. Res. Tech. 2009. © 2009 Wiley-Liss, Inc.     

Tales of tethers and tentacles: golgins in plants

As plant Golgi bodies move through the cell along the actin cytoskeleton, they face the need to maintain their polarized stack structure whilst receiving, processing and distributing protein cargo destined for secretion. Structural proteins, or Golgi matrix proteins, help to hold cisternae together and tethering factors direct cargo carriers to the correct target membranes. This review focuses on golgins, a protein family containing long coiled-coil regions, summarizes their known functions in animal cells and highlights recent findings about plant golgins and their putative roles in the plant secretory pathway.     

Ultrastructural changes in colonic epithelial cells in a rat model of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a global, chronic intractable disease. The functions of drugs and food components have been evaluated in models of IBD induced by 2,4,6‐trinitrobenzene sulfonic acid (TNBS). Here, we used transmission (TEM) and osmium‐maceration scanning (SEM) electron microscopy to evaluate the ultrastructure of colonic epithelial cells in rat models of IBD induced by TNBS. Histological evaluation revealed that the intestinal crypts in the most regions of the IBD‐model colons were deformed and we classified them as having high cell migration rates (HMIG). The remaining regions in the intestinal crypts retained a relatively normal structure and we classified them as having low cell migration rates (LMIG). Osmium‐maceration SEM revealed the mucosal fluid flowing in spaces without secretory granules in crypt goblet cells of both HMIG and LMIG regions, indicating the depletion of goblet cell mucin that is found in patients with IBD. The Golgi apparatus in absorptive cells was stacked and curled in both regions. Osmium‐maceration SEM showed membrane network structures resembling endoplasmic reticulum that were large and expanded in absorptive cells with HMIG rather than with LMIG regions in IBD‐model colons. These findings indicated that endoplasmic reticulum stress is associated with susceptibility to IBD and that the effects of various agents can be evaluated according to endoplasmic reticulum stress revealed by using electron microscopy in models of IBD induced by TNBS.     

The effect of Ginkgo biloba on the cerebellum of aging SAMP mouse--a TUNEL, bcl-2, and fMRI study

EGb 761, an extract from Ginkgo biloba that possesses neuroprotective properties, was fed to a strain of fast aging mice (SAMP-8) beginning at 3 weeks of age until they were sacrificed at 3 months and 11 months, respectively, along with an age-matched control group without herbal feeding. The aim of the study was to determine (1) the status of apoptosis and the status of bcl-2, a molecule involved in the fate of cells following injury, in the cerebella of these mice and (2) to analyze the functional changes as shown by fMRI images. The data indicated that there were no differences in apoptosis between the mice fed with EGb 761 and the control group at the two time points of 3 and 11 months of age. For bcl-2 positive cells, there was a decrease in density only in the cerebella of 11-month-old mice fed with the herbal extract when compared with controls. Functional studies indicated that while no changes were observed in the 3-month-old mice fed with Ginkgo biloba, an expansion of activated sites, possibly related to "synaptic reorganization and pathway alteration," was observed in the 11-month-old mice.     

Ki67 and doublecortin positive cells in the human prefrontal cortices of normal aging and vascular dementia

Immunohistochemical localizing of the proliferation of Ki67 nuclei and doublecortin positive cells were performed in the prefrontal cortex of normal aged and vascular dementia (multiple infarct dementia) patients. Positive Ki67 nuclei and doublecortin positive cells were observed in both groups, with slightly higher density in the prefrontal cortex of vascular dementia. When the Ki67 sites were superimposed with the neuronal specific enolase localizations, only about 5% of the cells was doubly labeled, indicating few proliferating cells were neurons. This percentage did not vary between specimens of normal aging and those of vascular dementia.     

Ultrastructural features of the myotendinous junction of the sternomastoid muscle in Wistar rats: From newborn to aging

The myotendinous junction (MTJ) is a major area for transmitting force from the skeletal muscle system and acts in joint position and stabilization. This study aimed to use transmission electron microscopy to describe the ultrastructural features of the MTJ of the sternomastoid muscle in Wistar rats from newborn to formation during adulthood and possible changes with aging. Ultrastructural features of the MTJ from the newborn group revealed pattern during development with interactions between muscle cells and extracellular matrix elements with thin folds in the sarcolemma and high cellular activity evidenced through numerous oval mitochondria groupings. The adult group had classical morphological features of the MTJ, with folds in the sarcolemma forming long projections called “finger‐like processes” and sarcoplasmic invaginations. Sarcomeres were aligned in series, showing mitochondria near the Z line in groupings between collagen fiber bundles. The old group had altered “finger‐like processes,” thickened in both levels of sarcoplasmic invaginations and in central connections with the lateral junctions. We conclude that the MTJ undergoes intense activity from newborn to its formation during adulthood. With increasing age, changes to the MTJ were observed in the shapes of the invaginations and “finger‐like processes” due to hypoactivity, potentially compromising force transmission and joint stability. Microsc. Res. Tech. 75:1292–1296, 2012. © 2012 Wiley Periodicals, Inc.     

MSCT多期增强扫描在肾脏透明细胞癌中的诊断价值

目的探讨多排螺旋CT(MSCT)多期增强扫描在肾脏透明细胞癌诊断中的规律性,提高对该肿瘤诊断水平。方法回顾性分析2016年1月~2018年6月14例均经手术切除病理证实为肾脏透明细胞癌患者的CT影像资料,所有病例均行MSCT平扫及多期动态增强扫描。结果14例肾脏透明细胞癌形态大多数呈圆形或者类圆形,瘤体最大径范围1.7cm^11.3cm,平均(4.8±1.4)cm,13例CT平扫时肿瘤密度不均匀,呈等低密度,1例呈等密度;12例出现坏死囊变,钙化1例,伴肾盂、肾盏侵犯2例;动态增强扫描可见12例包膜完整,1例均匀性强化,13例不均匀性强化;引入对比剂后皮质期,出现10例病灶强化幅度大于肾皮质,而仅4例低于肾皮质,三期平均CT值分别为110±30Hu,90±15Hu及75±14Hu,其中在实质期出现13例肿瘤强化幅度小于肾实质,仅1例大于肾实质。结论引入对比剂动态增强扫描后,肾脏透明细胞癌在皮质期明显不均匀强化,实质期强化幅度下降显著,呈现出典型的“快进快出”血流动力学强化方式,且肿瘤容易出现坏死、囊变为其特点。     

Anti-fibrotic and anti-inflammatory effect of mesenchymal stromal cell-derived extracellular vesicles in chronic kidney disease

Renal fibrosis and inflammation are common pathological features of chronic kidney disease (CKD). Since currently available treatments can only delay the progression of CKD, the outcome of patients with CKD is still poor. One therapeutic option for the prevention of CKD-related complications could be the use of mesenchymal stromal cells (MSCs), which have shown beneficial effects in tissue fibrosis and regeneration after damage. However, safety issues, such as cellular rejection and carcinogenicity, limit their clinical application. Among the bioactive factors secreted by MSCs, extracellular vesicles (EVs) have shown the same beneficial effect of MSCs, without any notable side effects. This heterogeneous population of membranous nano-sized particles can deliver genetic material and functional proteins to injured cells, prompting tissue regeneration. Here we describe the anti-fibrotic and anti-inflammatory properties of MSC-derived EVs in CKD preclinical models and summarize the potential molecular mechanisms involved in the regulation of renal fibrosis and inflammation.     

ER-Tracker dye and BODIPY-brefeldin A differentiate the endoplasmic reticulum and Golgi bodies from the tubular-vacuole system in living hyphae of Pisolithus tinctorius

Two fluorochromes, ER-Tracker^TM Blue-White DPX dye and the fluorescent brefeldin A (BFA) derivative, BODIPY-BFA, label the endoplasmic reticulum (ER) in hyphal tips of Pisolithus tinctorius and allow its differentiation from the tubular-vacuole system at the light microscope level in living cells. The ER-Tracker dye labels a reticulate network similar in distribution to ER as seen in electron micrographs of freeze-substituted hyphae. BODIPY-BFA stains a thicker axially aligned structure with an expanded region at the apex, which is similar to that seen when hyphae are stained with ER-Tracker dye in the presence of unconjugated BFA. This structure is considered to be ER modified by BFA, a view supported by ultrastructural observations of the effect of BFA on the fungal ER. Both fluorescent probes also stain punctate structures, which are most likely to be Golgi bodies. Neither probe labels the tubular-vacuole system.     

Occurrence of fenestral diaphragms and knots in renal glomerular endothelia of diabetic mutant MafA−/−MafK+ mice as revealed in embedment‐free transmission electron microscopy

Using the advantages (high contrast and transparency and efficient 3D viewing) of embedment‐free section transmission electron microscopy (TEM), the occurrence of numerous fenestral diaphragms was clearly shown in 3D en‐face viewing of the renal glomerular capillary endothelium of severe overt diabetes mellitus mice, which were generally MafA‐deficient and simultaneously MafK‐overexpressed specifically in pancreatic β‐cells. This presents another example of nephritis‐induced diaphragmed fenestrae in the renal glomerular endothelium. In addition, knot‐/umbilicus‐like structures discrete from and larger than the central knots of regular diaphragms of fenestrated endothelium were clearly demonstrated to occur randomly in the renal glomerular endothelial fenestrae of mutant mice and wild ones. The knot‐structures were revealed to be protrusions of underlining basement lamina in conventional TEM by section‐tilting observation. Microsc. Res. Tech. 78:207–212, 2015. © 2015 Wiley Periodicals, Inc.     

Ultrastructural and permeability features of microvessels in the periventricular area of senescence-accelerated mice (SAM)

Brain transfer of intravenously injected horseradish peroxidase (HRP) and the ultrastructural features of the vessels were examined in periventricular areas in senescence-accelerated mice (SAMP8), which show age-related deficits in learning and memory, and senescence-accelerated resistant mice (SAMR1), which do not show age-related deficits. In all mice examined with light microscopy, staining reaction for HRP was seen in the periventricular area adjacent to the medial side of the lateral ventricle. Electron microscopic examination in the periventricular area of young and old mice of both strains showed that the staining reaction for HRP appeared in the vesicular profiles of the endothelial cytoplasm, the cytoplasm of the perivascular cells, the basal lamina, and the adjoining extracellular spaces of the white matter, suggesting an incomplete blood-brain barrier (BBB) in the periventricular white matter. In addition, irregularly thickened endothelial cell cytoplasm, membranous inclusions within the basal lamina, and electron-dense endothelial cell cytoplasm were occasionally seen in aged SAMP8 mice. These findings were not observed in 3-month-old SAMP8 mice and 3- and 13-month-old SAMR1 mice. Perivascular collagen deposits were also frequently seen in aged SAMP8 mice. These findings indicate that the endothelial cells and pericytes in the periventricular white matter in aged SAMP8 mice have an ultrastructure with damaged BBB function. Intravascular substances can easily penetrate the periventricular white matter and the BBB of the vessels in the area can be deteriorated with aging in SAMP8 mice.     

装配式圆磨圆柱形铣刀的设计

提出利用刀体自身圆磨反装设计大直径圆柱形铣刀的方法 ,并推导了装配式圆磨圆柱形铣刀有关参数的设计公式。     

Elemental sulfur upregulated testicular testosterone biosynthesis by associating with altered gut microbiota in mice

Elemental sulfur has been used as a traditional Chinese medicine to treat the late-onset hypogonadism andimpotence without a clarified mechanism for many hundreds of years. In the present study, mice were received sulfuror distilled water for 35 days by daily intragastric gavage at a dose of 250 mg/kg body weight. Then, the serumtestosterone level and genes associated with testicular testosterone biosynthesis (TTB) were detected. The gutmicrobiota was also analyzed by 16S rRNA gene sequencing. Serum testosterone level was significantly increased by291.1% in sulfur-treated mice. The H₂S levels in serum and feces were significantly increased. The expression of genesassociated with TTB including StAR, p450c17, 3β-HSD, and P450scc in testes were significantly upregulated by Sulfurand NaHS, suggesting that sulfur promotes TTB depending on H₂S. In addition, sulfur increased the diversity of gutmicrobiota and the abundance of several bacteria associated with sulfur metabolism, including genus Prevotella, whichmight be positively associated with serum level of testosterone in boys. Five pathways including bile secretion,carotenoid biosynthesis, lipid biosynthesis proteins, propanoate metabolism, and biosynthesis of type II polyketideproducts, were identified to associate with sulfur. Together, our results suggested that sulfur upregulated testiculartestosterone biosynthesis via H₂S, which was associated with alteration of gut microbiota in mice. Our studyhighlights a mechanism for the treatment of late-onset hypogonadism and impotence by sulfur.     

Changes in the amount of kidney pigmented macrophage aggregates throughout the breeding cycle of female Ohrid trout, Salmo letnica Kar. (Teleostei, Salmonidae)

Changes in fish macrophages (Macs) are useful indicators of environmental pressures, but responses due to chemical and nonchemical stresses may be confounded by natural sources of variability. These may include sex and gonadal stage. In this study, we start addressing the following question: is the seasonally dependent ovary stage a factor to consider when using kidney Macs as biomarkers? To tackle this problem, the relative amount of pigmented Macs in kidney (head, trunk, and tail portions) was stereologically estimated in Ohrid trout, and related with the breeding status. The amount of Macs significantly increased from pre vitellogenesis to late vitellogenesis and showed a decreasing trend then after, with lower values noted after spawning in the head (1.9% versus 7.5% versus 2.0%), trunk (1.8% versus 7.5% versus 2.5%), and tail (2.5% versus 6.7% versus 2.9%) kidney. The decrease seen at spawning was significant in head and trunk kidney, and at post spawning it was significant for all kidney portions. The amounts of Macs were positively correlated with the ovary relative weights and plasma estradiol levels. We proved for the first time that fish kidney pigmented Macs can vary in amount during the breeding cycle. Our data, combined with literature, strongly support that the sex‐steroid profile and kidney status‐seasonal remodeling both influence the Macs pool; likely not only in female trout. So, while increases in Macs may warn of ecosystem problems, we show that using kidney Macs for biomonitoring should also take into account seasonally, particularly that related with ovary maturation. Microsc. Res. Tech. 2011. © 2011 Wiley Periodicals, Inc.     

肾功能不全患者超声心动图心肌做功指数水平及意义

目的 探讨肾功能不全患者超声心动图心肌做功指数(Tei指数)水平及意义.方法 选取2016年1月至2018年12月在我院就诊的90例慢性肾功能不全患者(观察组),其中轻中度损害患者51例,重度损害患者39例,同时选取健康志愿者90例作为对照组,比较各组Tei指数等.结果 观察组Tei指数、左心室舒张末期内径(LVEDD...     

圆体成形车刀加工圆锥面时双曲线误差的定量分析

分析了用圆体成形车刀加工圆锥面时产生双曲线误差的原因，并用数学推导方法求出了双曲线误差值的大小和各影响因素之间的关系。     

Ultrastructure of the intercalated body,a novel organelle associated with fluid forming cells in the organ of Corti

The intercalated body is a newly discovered organelle in the inner and outer spiral sulcus cells of the mouse organ of Corti. The organelle was found in the cochleas of 14-day and older intact mice and in organs in culture of corresponding ages. The organelle consists of a stack of interconnected cisternae of endoplasmic reticulum and of membrane bound rodlets that are intercalated between, and run parallel to, the cisternae. The cisternal membranes are predominantly smooth, but some may display ribosomes. Most rodlets are from 1 to 2 μm long, about 0.1 μm wide, and contain electron dense material. Mitochondria are commonly associated with or incorporated into the organelle. Some electron micrographs suggest that the rodlets may originate from modified mitochondria. It is our impression that the formation of the organelle begins with the apposition of cisternae and mitochondria. Cisternal-associated mitochondria appear to constrict, elongate, and lose their inner membranes. In both the intact animal and in culture, the cells of the inner and outer spiral sulci display microvilli, apical junctional complexes, lateral intercellular spaces containing interdigitating cell processes, and appear to be involved in fluid formation. Moreover, in culture, the cells of inner and outer spiral sulci as well as some cells proliferating in the outgrowth zone participate in fluid formation, producing large fluid pockets. All these cells commonly contain intercalated bodies. It is possible that in the intact animal, as in culture, intercalated bodies may play a role in fluid regulation in the immediate vicinity of the hair cells.     

Detection of injected fluorescence-conjugated IgG in living mouse organs using "in vivo cryotechnique" with freeze-substitution

In this experiment, we performed the "in vivo cryotechnique" in tandem with fluorescence microscopy. The fluorescein isothiocyanate (FITC)-conjugated goat anti-rabbit immunoglobulin (IgG) antibody (FITC-IgG) was directly injected into mouse livers or kidneys, which were then frozen in vivo by pouring an isopentane-propane mixture (-193 degrees C) cooled in liquid nitrogen over these living organs. The organs were subsequently freeze-substituted in acetone containing paraformaldehyde at about -80 degrees C, then gradually brought up to a room temperature, infiltrated with 30% sucrose and refrozen. Some well-frozen areas 300-400 mum below the frozen tissue surface were cryocut into several slices. The slices were observed under the fluorescence microscope. By examining the distribution of FITC-IgG in the frozen livers, some aspects of functional blood circulation in the liver, such as the concept of the liver lobule, were reconfirmed. This also confirmed that the blood flow in the liver after the FITC-IgG injection was normal. The subsequent preparation of the specimens with immunohistochemistry, using the tetramethylrhodamine (TRITC)-conjugated anti-mouse IgG antibody, allowed us to visualize the localizations of both the original mouse IgG and the injected goat IgG in the cryosections with different color images. The experimental protocol presented demonstrates the in situ localization of the various proteins labeled with fluorescent probes, and it can, in conjunction with immunohistochemistry, localize proteins in cells and tissues.