Logistic regression analysis of myxoid sarcomas: A cytologic study

The objective of this study was to identify key diagnostic cytologic criteria for the most common myxoid sarcomas studied by fine-needle aspiration cytology. We reviewed 27 myxoid malignant fibrous histiocytomas, 8 chordomas, 16 chondrosarcomas, and 12 myxoid liposarcomas in which both cytologic specimens and final histopathologic diagnoses were available. All specimens were coded as to the presence or absence of the following variables: high cellularity, low cellularity, tissue fragments, epithelial fragments, pale/ loose ground substance, dense ground substance, chondroid fragments, large amount of myxoid material, small amount of myxoid material, capillary vessel networks, pleomorphism, binucleate cells, multinucleate cells, physaliphorous cells, cells in lacunae, signet ring cells, lipoblasts, fibroblast-like cells, histiocyte-like cells, stellate cells, long filamentous cells, short spindle cells, osteoclastic giant cells, nuclei with pointed ends, nuclei with cigar-shaped ends, fish-hook nuclei, round/ ovoid nuclei, naked nuclei, large nucleoli, small nucleoli, mitotic figures, abnormal mitotic figures, intracytoplasmic hemosiderin deposits, background cells, fat, cytoplasmic vacuoles, and pleomorphic giant cells. A logistic regression analysis was performed to identify the variables predictive of myxoid malignant fibrous histiocytoma, chordoma, myxoid chondrosarcoma, and myxoid liposarcoma. The statistical analysis selected pleomorphic giant cells and the presence of fibroblast-like cells as most predictive of malignant fibrous histiocytoma, physaliphorous cells as most closely associated with chordoma, chondroid fragments as most predictive of chondrosarcoma, and lipoblasts as most predictive of liposarcoma. While myxoid lesions have many overlapping cytologic features, key criteria including the presence of lipoblasts, physaliphorous cells, chondroid fragments, and pleomorphic giant cells are useful in subclassifying these neoplasms. Diagn. Cytopathol. 1998;19:355–360. © 1998 Wiley-Liss, Inc.     

Congenital chordoma of the skin in a lamb (first report)

Chordoma is a rare tumor in human beings and animals that originates from mesoderm-derived notochord. Although many cases of chordoma have been reported in human, dog, cat, rat, mink, and ferret, no report has been previously described in ruminants. This case report describes the clinical and histopathological findings of a congenital chordoma located in the occipital skin area of a 6-day-old, male, Iranian fat-tailed lamb. Histopathologic examination showed non-encapsulated tumor within the deep dermis. The neoplastic tissue consisted of physaliphorous cells with a fine fibrovascular stroma. The physaliphorous cells were immunoreactive with antibodies against vimentin, pancytokeratin, and S100 protein. Therefore, chordoma was diagnosed. To the best of the authors’ knowledge, this is the first case of chordoma in ruminants in the veterinary literature.     

Cervical chondroid chordoma in a Shetland sheep dog

A spayed female Shetland sheep dog aged 12 years was presented for examination with ataxia and hindlimb paralysis. Extradural spinal cord compression was found at the level of vertebrae C6-C7 by radiography and myelocomputed tomography. A jelly-like mass (0.6 x 1.3 cm) was removed surgically. Histopathological findings were characterized by proliferation of vacuolated polygonal cells (physaliphorous cells) in a mucinous matrix and the presence of chondroid tissue shown immunohistochemically to express S-100. The physaliphorous cells were immunolabelled strongly for vimentin and S-100, and weakly for cytokeratin. A diagnosis of canine cervical chondroid chordoma was made. This is considered to be the first report of a chondroid chordoma originating from the cervical region of the spine in the dog.     

Cytopathological dilemma of anaplastic sacral chordoma with radiological and histological corroboration

Chordoma is a relatively rare locally invasive and potentially malignant tumor of fetal notochord origin, affecting the axial skeleton. Cytopathological diagnosis of chordoma is favored by the presence of characteristic physaliphorous cells, bearing abundant foamy cytoplasm dispersed in a myxoid matrix. Anaplastic chordoma or dedifferentiated chordoma, an even rarer variant, can cause a diagnostic confusion with chondrosarcoma from the cytopathological point of view, with similar chondromyxoid matrix and atypical cells. Hence, chordoma bearing anaplastic features needs to be identified and should be distinguished from chondrosarcoma on aspiration cytopathology. We present a case of anaplastic sacral chordoma in a man 59 years of age, causing extensive destruction of sacrum and invading the paravertebral tissues as evidenced by radiology. Fine needle aspiration cytopathology revealed few large pleomorphic hyperchromatic cells, admixed with characteristic physaliphorous cells and myxoid matrix. The cytopathological diagnosis has been confirmed by histopathology and immunohistochemistry. Since anaplastic chordoma bears an unfavorable prognosis, it should be suspected on preoperative aspiration cytopathology. Clinicoradiological correlation along with histopathological and immunohistochemical confirmation is necessary subsequently.     

Cellular composition of atherosclerotic and uninvolved human aortic subendothelial intima. Light-microscopic study of dissociated aortic cells.

Alcoholic-alkaline dissociation was used in the study of cellular composition of human aorta. Cells were isolated from an uninvolved intima and intima with different types of atherosclerotic lesions: fatty infiltration, fatty streak, and atherosclerotic plaque. In the isolated suspension we evaluated the ratio of four previously described morphologic forms of cells: stellate, elongated, elongated with side processes, and flat cells of irregular shape. It was demonstrated that the quota of stellate cells in an atherosclerotic lesion considerably exceeds that of the normal intima. For elongated cells the opposite is true. The other two cell forms are represented in the uninvolved and atherosclerotic intima in approximately equal proportions. Alteration of the ratio of different morphologic forms occurs because of the fact that the number of cells belonging to different morphologic forms increases disproportionately in the lesion zone. Specifically, the number of stellate cells is increased much more substantially, compared with elongated cells.     

Intimal cells and atherosclerosis. Relationship between the number of intimal cells and major manifestations of atherosclerosis in the human aorta.

The subendothelial intima of human aorta is populated by cells of various shapes. Round and ovoid cells which are lymphocyte- and monocyte-like hematogenous cells account for less than 5% of the cell population. The bulk of the intimal population (over 95%) is made up of cells that can be described as elongated, stellate, elongated with side processes, and irregularly shaped. To identify these morphologic forms, the authors have used target electron microscopy. It has been established that elongated cells devoid of side processes possess all the ultrastructural features of differentiated smooth muscle cells: a developed contractile apparatus in the form of microfilament bundles with dense bodies occupying most of the cytoplasm, basal membrane surrounding the whole of the cell, and micropinocytotic vesicles along the plasma membrane. The other morphologic forms have an ultra-structure that allows us to identify them as so-called modified smooth muscle cells. They differ from the typical smooth muscle cells in that they have fewer contractile structures and a more developed biosynthetic apparatus. Some of stellate and irregular shaped cells are utterly devoid of contractile structures. To quantitate the number of cells of different morphologic forms, the authors used alcoholic-alkaline dissociation of prefixed intima. It was established that the intimal population is multiplied at the site of an atherosclerotic lesion, the number of stellate cells being increased much more substantially, compared with other morphologic cell forms. It was found that an increase in the number of stellate cells is related to such sequelae of atherosclerosis in aorta as intimal thickening, deposition of lipids, and an increased amount of collagen. There was a high positive correlation between the alteration in the stellate cell number occurring in the intima and the above-mentioned parameters (correlation coefficients were 0.732, 0.800 and 0.953, respectively). The correlations between these indexes and the total number of intimal cells or the number of cells belonging to each of the other morphologic forms were not so high. A multivariate analysis gave similar results. Thus, it may be suggested that stellate cells are the principal cell type involved in the disease. This report discusses the origin of stellate and other intimal cells and their role in atherogenesis.     

Apoptotic body engulfment by a human stellate cell line is profibrogenic

Hepatocyte apoptosis and stellate cell activation are both features of chronic liver diseases, but a relationship between these events has not been explored. In macrophages, engulfment of apoptotic bodies induces expression of transforming growth factor-beta (TGF-beta), a profibrogenic cytokine. We examined whether a similar response occurs in stellate cells. Fluorescently labeled hepatocyte apoptotic bodies were added to cultures of primary and immortalized human stellate cells. Stellate cells, but not hepatocytes, readily engulfed apoptotic bodies in a time-dependent manner as assessed by confocal microscopy. The activation of primary and immortalized human stellate cells after incubation with apoptotic bodies, as well as their fibrogenic activity, was indicated by an increase in alpha-smooth muscle actin (primary cells), TGF-beta1, and collagen alpha1(I) mRNA (primary and immortalized cells). The profibrogenic response was dependent upon apoptotic body engulfment, because nocodazole, a microtubule-inhibiting agent, blocked both the engulfment and the increase of TGF-beta1 and collagen alpha1(I) mRNA. As described in primary rodent stellate cells, up-regulation of collagen alpha1(I) mRNA was inhibited by a PI-3K inhibitor (LY294002) and a p38 mitogen-activated protein kinase inhibitor (SB203580) in LX-1 cells. In conclusion, these data support a model in which engulfment of hepatocyte apoptotic bodies by stellate cells leads to a fibrogenic response by eliciting a kinase-signaling pathway.     

垂体腺瘤中垂体激素与S-100蛋白免疫组化双重染色观察

目的：探讨滤泡星状细胞在垂体腺瘤分类中的意义及滤泡星状细胞与内分泌细胞之间的关系。方法：应用免疫组化双重染色方法,对４２ 例人重体腺瘤的垂体激素与 Ｓ１００ 蛋白表达进行对照观察。结果：垂体腺瘤组织中的滤泡星状细胞有两种情况,一种为腺瘤组织中可见散在分布的滤泡星状细胞,并可见１ 个瘤细胞既有 Ｓ１００ 蛋白表达,又含激素分泌颗粒;另一种为滤泡星状细胞构成了腺瘤的一种主要的细胞成分。结论：滤泡星状细胞与内分泌细胞的功能密切相关,可能在调整内分泌细胞的产生和激素释放方面起一定的作用;滤泡星状细胞腺瘤应作为垂体无功能腺瘤的一个单独类型。     

The fine structure of two types of stellate cells in the anterior division of the anteroventral cochlear nucleus of the cat

The stellate cells in the anterior division of the anteroventral cochlear nucleus of the cat were studied with the electron microscope. Although only one type of stellate cell has been identified at the light-microscopic level, two types can be recognized in electron micrographs. Both can be distinguished from the bushy cells that are also present in the anterior division, since they lack the nuclear cap of granular endoplasmic reticulum characteristic of the bushy cells. The somas of the type I stellate cells receive very few synaptic contacts, but the number of synaptic terminals increases markedly along the proximal dendrites. In contrast, both the soma and proximal dendrites of the type II stellate cells receive numerous synaptic contacts. Both neuronal types receive synaptic endings that contain large, spherical vesicles and that disappear after cochlear ablation. Both types of stellate cells are also contacted by synaptic terminals with small vesicles similar to those that contact bushy cells. In addition, the type II stellate cells receive a type of synaptic ending unlike those previously described. This is a relatively large terminal, containing large, flattened or disk-shaped vesicles, and forming slightly asymmetric synaptic complexes with the postsynaptic cell. These terminals as well as those with small synaptic vesicles survive cochlear ablation. The sources of the non-cochlear terminals are not known.The results indicate that the anterior division of the anteroventral cochlear nucleus of the cat contains at least three types of large neurons, each of which receives synaptic input from the cochlea as well as from other sources. The organization of the synaptic endings on the surface of each type is different. Since distinctive arrangements of cochlear and non-cochlear synaptic terminals could result in different response patterns to acoustic stimuli, each of these neuronal types may correspond to a different type of single unit, defined physiologically.     

Hepatic angiomyolipoma and hepatic stellate cells share a similar gene expression profile

BACKGROUND AND AIMS: Angiomyolipomas (AMLs) of the liver are rare neoplasms composed of large epithelioid cells with intermixed fat and blood vessels. Hepatic AMLs have no clear normal-cell counterpart in the liver. However, AMLs and stellate cells both are positive for neural crest-derived markers including HMB-45 antigen. METHODS: To further explore the similarities between hepatic AMLs and stellate cells, gene expression of a hepatic AML was studied by cDNA microarray. Real-time polymerase chain reaction was used to confirm gene expression. Hepatic stellate cells can be quiescent, activated, or have a myofibroblastic phenotype depending on their state of activation. Expression of known markers of activated stellate cells was compared between the AML, activated primary mouse stellate cells, and stellate cell lines with activated and myofibroblastic phenotypes. Next, 5 novel genes from the AML were selected because they were not previously known to be markers of stellate cells and mRNA expression measured in the activated mouse stellate cells and in myofibroblastic stellate cell lines. Finally, expression levels of 10 novel genes were determined in 5 cirrhotic and 5 noncirrhotic human livers. RESULTS: Overexpression of known markers of activated stellate cells including transforming growth factor beta (TGF- beta ), smooth muscle actin, and collagen was found in the hepatic AML. Three of 5 novel markers that were identified in the AML, RRAD (Ras-related associated with diabetes), CTSK (cathepsin K), and NIBAN were also found to be overexpressed in activated stellate cells compared with quiescent or myofibroblastic stellate cells. In addition, 9 of 10 novel genes overexpressed in AML were also overexpressed in cirrhotic human livers versus noncirrhotic livers. CONCLUSIONS: Hepatic AMLs share a similar gene expression profile and may differentiate toward activated stellate cells.     

Role of macrophages and stellate cells in the pathogenesis of veno-occlusive disease: an electron microscopic case study

Veno-occlusive disease (VOD) is an entity described as a triad of pathologic findings including ascites, tender hepatomegaly, and elevated liver enzymes. The prognosis of patients suffering from VOD is highly variable, ranging from slow resolution to the need for liver transplant. The histopathology of VOD has been described by light and electron microscopy. However, the pathogenesis of VOD is still largely unclear. In the present case study, we report the significant findings in a case of pediatric VOD following chemotherapy. We studied the liver biopsy by light and electron microscopes. In addition to previous reported findings of occlusion of the central vein with endothelial cell damage, proliferation and activation of stellate cells, and collagen deposition in the central vein wall, there were prominent activated macrophages within the lumen and wall of central veins. The following mechanism of VOD was proposed: Tissue damage activates monocytes through monocyte chemoattractant protein-1. The secretory macrophages release TGF-beta, which promotes proliferation of stellate cells to cause collagenous thickening of the central vein. The activated stellate cells produce collagen. The normal drainage of the Space of Disse and sinusoids draining into the central vein are blocked by the fibrosis. This leads to extravasated RBCs trapped within the thickened central vein wall and impaction of RBCs in the sinusoids.     

Storage of lipid droplets in and production of extracellular matrix by hepatic stellate cells (vitamin A-storing cells) in Long-Evans cinnamon-like colored (LEC) rats

LEC rats spontaneously develop hepatocellular carcinoma with cholangiofibrosis after chronic hepatitis, but the mechanism of development of the hepatic injury is not clear. To investigate the role of hepatic stellate cells in induction or suppression of hepatic fibrosis, we morphologically examined the liver of LEC rats. Accumulation of copper was analyzed by the Danscher-Timm's sulfide-silver method. Histopathological changes were evaluated by hematoxylin and eosin staining, and by Masson's trichrome method. Activated stellate cells were identified by immunostaining method for alpha-smooth muscle actin. Cytological alterations of the stellate cells were investigated by transmission electron microscopy. To evaluate the lipid content in the stellate cells, we analyzed the area of lipid droplets of the cells by morphometric analysis. Also for evaluation of the changes in the number of stellate cells, the numbers of nucleated stellate cells and parenchymal cells were counted and statistically analyzed. Hepatic parenchymal cells showed excessive accumulation of copper at 5 weeks of age. Submassive necrosis was observed at 19 weeks of age. The liver of LEC rats 1.5 years of age showed cholangiofibrosis and subcellular injury of hepatic parenchymal cells. However, no diffuse hepatic fibrosis was observed in the liver, and hepatic stellate cells around the regions of cholangiofibrosis were negative for alpha-smooth muscle actin. The area of lipid droplets of a stellate cell in the liver of LEC rats was 1.6 to 1.8 times as large as that of normal Wistar rats. The hepatic stellate cells did not participate in the accumulation of collagen fibers around themselves when the cells contained a large amount of vitamin A-lipid droplets, even though the development of hepatic lesions was in progress. Our present data are consistent with our previous hypothesis that there is an antagonistic relationship between the storage of vitamin A and the production of collagen in stellate cells.     

The ultrastructure of the stellate cell in the rabbit pars distalis,

Stellate cells in the rabbit pars distalis have been studied electron microscopically from birth to adulthood. During this period the stellate cells are found in abundance throughout the pars distalis and are the only consistently agranular cells observed in the pars distalis parenchyma. Identifying features of stellate cells are fine cytoplasmic filaments and farreaching cytoplasmic processes. The cytoplasmic processes ramify between adjacent parenchymal cells and are connected to other stellate cells by desmosomes. The stellate cells, linked to one another by desmosomes, thus constitute a meshwork within which the granulated parenchymal cells reside. Processes of stellate cells are also found interposed between the parenchymal basal lamina and the granulated parenchymal cells. The cytoplasmic filaments are distributed throughout the cytoplasm and extend into the fine processes. The filaments do not appear to have any particular orientation to the plasma membrane. Compared to granulated cell types, the cytoplasmic organization of stellate cells is not complex. Mitochondria, smooth and granular endoplasmic reticulum, Golgi membranes, ribosomes, dense bodies and lipid droplets are distributed throughout the cytoplasm, but not in great numbers. Nuclear chromatin is uniformly distributed. A nucleolus may or may not be evident. The ultrastructural features of the stellate cells are in many respects unchanged from birth to adulthood. An exception is in one-to-two-day-old neonates when in some stellate cells the quantity of cytoplasmic filaments appears increased and there is hyperplasia of the endoplasmic reticulum and Golgi membranes. A similar hyperplasia of these stellate cell organelles can be produced experimentally in adult rabbits by administration of Metopirone. Though the morphological evidence supports a structural or metabolically supportive function for the stellate cell, an additional role as the possible source of adrenocorticotrophic hormone is also discussed.     

Storage of lipid droplets in and production of extracellular matrix by hepatic stellate cells (vitamin A‐storing cells) in Long‐Evans cinnamon‐like colored (LEC) rats

LEC rats spontaneously develop hepatocellular carcinoma with cholangiofibrosis after chronic hepatitis, but the mechanism of development of the hepatic injury is not clear. To investigate the role of hepatic stellate cells in induction or suppression of hepatic fibrosis, we morphologically examined the liver of LEC rats. Accumulation of copper was analyzed by the Danscher‐Timm's sulfide‐silver method. Histopathological changes were evaluated by hematoxylin and eosin staining, and by Masson's trichrome method. Activated stellate cells were identified by immunostaining method for α‐smooth muscle actin. Cytological alterations of the stellate cells were investigated by transmission electron microscopy. To evaluate the lipid content in the stellate cells, we analyzed the area of lipid droplets of the cells by morphometric analysis. Also for evaluation of the changes in the number of stellate cells, the numbers of nucleated stellate cells and parenchymal cells were counted and statistically analyzed. Hepatic parenchymal cells showed excessive accumulation of copper at 5 weeks of age. Submassive necrosis was observed at 19 weeks of age. The liver of LEC rats 1.5 years of age showed cholangiofibrosis and subcellular injury of hepatic parenchymal cells. However, no diffuse hepatic fibrosis was observed in the liver, and hepatic stellate cells around the regions of cholangiofibrosis were negative for α‐smooth muscle actin. The area of lipid droplets of a stellate cell in the liver of LEC rats was 1.6 to 1.8 times as large as that of normal Wistar rats. The hepatic stellate cells did not participate in the accumulation of collagen fibers around themselves when the cells contained a large amount of vitamin A‐lipid droplets, even though the development of hepatic lesions was in progress. Our present data are consistent with our previous hypothesis that there is an antagonistic relationship between the storage of vitamin A and the production of collagen in stellate cells. Anat Rec 258:338–348, 2000. © 2000 Wiley‐Liss, Inc.     

An improved method for the purification of stellate cells from rat liver with Dichloromethylene Diphosphate (CL2MDP)

Hepatic perisinusoidal cell population consists of hepatic stellate cells, Kupffer cells, endothelial cells, and Pit cells. These cells are isolated by enzymic digestion and purified by density gradient centrifugation. With isolation of stellate cells, conventional method is unable to eliminate the contamination of Kupffer cells because the densities of these two cells are similar. We report here an improved method for isolation of highly purified hepatic stellate cells, using dichloromethylene diphosphate (CL2MDP), which has selective cytotoxicity of Kupffer cells. Three days after the single intravenous administration of liposome-encapsulated CL2MDP, the Kupffer cells disappeared almost completely from the liver. Following Percoll density gradient centrifugation, the purity of the hepatic stellate cells exceeded 98% without any contamination of the Kupffer cells. Kupffer cells are reported to affect the physiological functions of stellate cells. The availability of highly purified stellate cells will facilitate the investigation of their functions in primary culture.     

Ion channels in spinal cord astrocytes in vitro. II. Biophysical and pharmacological analysis of two Na+ current types.

1. Na+ currents expressed in astrocytes cultured from spinal cord were studied by whole cell patch-clamp recording. Two subtypes of astrocytes, pancake and stellate cells, were morphologically differentiated and showed expression of Na+ channels at densities that are unusually high for glial cells (2-8 channels/microns2) and comparable to cultured neurons. 2. Na+ currents in stellate and pancake astrocytes were comparable to neuronal Na+ currents with regard to Na(+)-current activation (tau m) and inactivation (tau h) time constants, which were equally fast in both astrocyte types. However, they differed with respect to voltage dependence of activation, and current-voltage (I-V) curves were approximately 10 mV more positive in stellate cells (-11.1 +/- 5.6 mV, mean +/- SD) than in pancake cells (19.7 +/- 4.5 mV). Steady-state activation (m infinity curves) was 16 mV more negative in pancake (mean V1/2 = -48.8 mV) than in stellate cells (mean V1/2 = -32.7 mV). 3. Steady-state inactivation (h infinity curves) of Na+ currents was distinctly different in the two astrocyte types. In stellate astrocytes h infinity curves had midpoints close to -65 mV (-64.6 +/- 6.5 mV), similar to most cultured neurons. In pancake astrocytes h infinity-curves were approximately 25 mV more negative, with midpoints close to -85 mV (84.5 +/- 9.5 mV). 4. The two forms of Na+ currents were additionally distinguishable by their sensitivity to tetrodotoxin (TTX). Na+ currents in stellate astrocytes were highly TTX sensitive [half-maximal inhibition (Kd) = 5.7 nM] whereas Na+ currents in pancake astrocytes were relatively TTX resistant, requiring 100- to 1,000-fold higher concentrations for blockage (Kd = 1,007 nM). 5. Na+ currents were fit by the Hodgkin-Huxley (HH) model. In pancake astrocytes, as in squid gigant axons, Na(+)-current kinetics could be well described with an m3h model, whereas in stellate astrocytes Na+ currents were better described with higher-order power terms for activation (m). On average, best fits were obtained using an m4h model. 6. Pancake astrocytes were capable of generating action-potential (AP)-like responses under current clamp whereas stellate astrocytes were not. The h infinity curve for APs shows that membrane potentials more negative than -70 mV are required to allow these responses to occur.(ABSTRACT TRUNCATED AT 400 WORDS)     

Immunohistochemical analysis of development of desmin-positive hepatic stellate cells in mouse liver

Development of desmin-positive hepatic stellate cells was studied in mice using double immunofluorescent techniques and in vitro cultures with special attention given to their cell lineages. Several studies recently reported on the presence of cells that are immunologically reactive with both antidesmin and anticytokeratin antibodies in young fetal rat livers, and suggested the possibility that these cells give rise to hepatocytes and hepatic stellate cells. At early stages of mouse liver development, stellate cells with desmin-positive filaments were scattered in the liver parenchyma. However, the stellate cells definitely differed from hepatoblasts and hepatocytes in terms of their morphology and expression of desmin and hepatoblast and hepatocyte-specific E-cadherin in the liver. Fetal hepatoblasts and hepatocytes did not react with antidesmin antibodies, nor did desmin-positive stellate cells express E-cadherin in vivo and in vitro. Thus it is likely that desmin-positive stellate cells and hepatoblasts belong to different cell lineages. In the fetal liver, the desmin-positive stellate cells surrounded blood vessels, and extended their processes to haematopoietic cells and megakaryocytes. Many, but not all, hepatoblasts and hepatocytes were observed to be associated with the stellate cells. At fetal stages, cellular processes positive for desmin in the stellate cells were also thick compared with those in the adult liver, in which desmin-positive stellate cells lay in Disse's space and were closely associated with all hepatocytes. These developmental changes in the geography of desmin-positive cells in the liver parenchyma and their morphology may be associated with their maturation and interactions with other cell types.     

Morphology of identified entorhinal neurons projecting to the hippocampus. A light microscopical study combining retrograde tracing and intracellular injection

Cells of origin of the entorhinohippocampal pathway were retrogradely labeled by injection of Fast Blue into the ipsilateral hippocampus. The cells, which were located in layers I, II and III of the lateral entorhinal cortex, were then intracellularly injected with Lucifer Yellow to reveal their complete morphology. We could thus establish that among the hippocampally projecting entorhinal cells there are pyramidal and pyramid-like cells, spiny stellate cells of various shapes, sparsely spinous horizontal and multipolar cells. The involvement of horizontal and multipolar neurons in projections has not previously been recognized although all of these cell types have already been described in Golgi studies.

The results indicate that the organization of the perforant path is more complex than has been assumed. Finally, they are at variance with the classical concept which subdivides cortical neurons into projection neurons (pyramidal and spiny stellate) and interneurons (non-pyramidal, local circuit neurons).     

转化生长因子β1刺激改良培养小鼠原代肝星状细胞的活化

背景：肝星状细胞是肝内分泌细胞外基质的关键细胞类型,因此在肝纤维化研究中很重要。 目的：实验改良了肝星状细胞原代培养方法,获得充足的细胞量,用转化生长因子β1刺激活化,研究致纤维化的相关因子表达情况。 方法：氯胺酮麻醉小鼠后采用门静脉穿刺原位灌注肝脏的方法分离肝脏,采用密度梯度离心获得肝星状细胞,利用形态学、免疫荧光染色等方法对原代肝星状细胞进行鉴定;将培养24 h肝星状细胞用质量浓度10 μg/L转化生长因子β1刺激48 h,同时设PBS组进行对比。 结果与结论：通过原位灌注肝脏并且酶消化的方法可以成功获得小鼠原代肝星状细胞,并且锥虫蓝染色活率为(97.2±0.8)%,免疫荧光染色纯度为(90.4±1.2)%,细胞计数总量约2.5×106/只。实时荧光定量聚合酶链式反应检测显示,与PBS组比较,转化生长因子β1刺激组的肝星状细胞平滑肌肌动蛋白α、Ⅰ型胶原蛋白、转化生长因子β受体1、转化生长因子β受体2 mRNA表达水平明显升高(P < 0.05)。结果证实,实验采用的改良的培养方法可更高效高质量的获得原代肝星状细胞,转化生长因子β1刺激可导致肝星状细胞活化,分泌致纤维化因子。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程      

Activated hepatic stellate cells in liver cirrhosis. A morphologic and morphometrical study

Hepatic stellate cells have been considered the most important cell-type involved in hepatic fibrogenesis. Proliferation and differentiation of hepatic stellate cells into myofibroblast-like cells has been related to the development of liver fibrosis. The alpha-actin expressed by hepatic stellate cells was considered a marker of their activation to myofibroblast-like cell. The aim of this study is to evaluate the changes in morphology, distribution, percentage and alpha-smooth muscle actin expression of hepatic stellate cells in normal and cirrhotic livers, and to correlate activated hepatic stellate cells with the progression of fibrosis. Human liver biopsies (n=121) were divided in five groups: 1) normal livers (controls); 2) cirrhosis post-HCV hepatitis; 3) cirrhosis post-HBV hepatitis; 4) non viral related cirrhosis; 5) recurrent HCV hepatitis after orthotopic liver transplantation. Samples immunostained with anti alpha-smooth muscle actin antibody by immunoperoxidase method were semi-quantitatively evaluated. Liver fibrosis was quantified by computer image analysis on specimens stained with Masson's trichrome. In normal adult livers stellate cells were very rarely stained for alpha-smooth muscle actin. In cirrhotic livers, a strongly enhanced percentage of stellate cells expressing alpha-smooth muscle actin was detected in cirrhotic fragments with respect to the control group, with a significant correlation between alpha-smooth muscle actin positive stellate cells and the volume fraction of fibrosis. Moreover, liver biopsies of recurrent hepatitis revealed an increased number of activated stellate cells compared to normal livers, and intermediate volume fraction of fibrosis. These results confirmed that a direct correlation existed between activated stellate cells and the progression of fibrosis. Alpha-smooth muscle actin confirmed to be a reliable marker of hepatic stellate cells activation also in precocious stages of the disease.