Cytoplasmic Striations Research Articles

Tripterygium drug-loaded liposome alleviates renal function by promoting vascularization and inhibiting fibrosis.

Introduction: Tripterygium species have been traditionally used in Chinese medicine for treating various conditions. The aim of the study was to construct a drug-modified renal infarction targeting liposome (rTor-LIP) containing Tripterygium in order to improve the therapeutic effect on renal injury. Methods: rTor-LIP was prepared using the extruder method containing Tripterygium solution. The preparation was characterized by transmission electron microscopy, Marvin laser particle size analyzer, and Western blotting. In vitro experiments were conducted to verify the biocompatibility of rTor-LIP, and in vivo experiments were conducted to verify the therapeutic effect of rTor- LIP on renal injury. Results and discussion: The surface of rTor-LIP was regular and oval. In vitro results showed that after co-incubation with rTor-LIP, endothelial cells did not show significant apoptosis, and there were no significant abnormalities in the mitochondrial metabolism. The in vivo results showed that the morphology of endothelial cells in the rTor-LIP group was uniform and the cytoplasmic striations were clear, but the local striations had disappeared. Thus, rTor-LIP nano-targeted liposomes can effectively target hypoxic kidney tissue, providing a new idea for the treatment of renal infarction.

Role of 5-azacytidine in the differentiation of rat bone marrow mesenchymal stem cells into cardiomyogenic cells

Introduction Increasing attention is being paid to the use of mesenchymal stem cells (MSCs) for treatment of human diseases such as myocardial infarction. Aim To study the differentiation of the bone marrow mesenchymal stem cells (BM-MSCs) into cardiomyogenic cells using 5-azacytidine. Materials and Methods Forty adult male albino rats were used in this study. BM-MSCs were isolated and cultured in a complete Dulbecco's modified Eagle's medium containing 1% antibiotics and 10% fetal bovine serum (the control group). Second passaged cells were treated with 10μmol/l 5-azacytidine for 72h. Then, the medium was removed and kept in a 5-azacytidine-free medium for 4 weeks (the 5-azacytidine-treated group). The adherent cells of both groups were examined using a phase-contrast microscope and a transmission electron microscope. Expressions of cytoskeleton protein desmin and cardiac muscle-specific cardiac troponin T were assessed by immunohistochemistry. Results BM-MSCs of the control group were spindle and star shaped with multiple processes and vesicular nuclei. After adding 5-azacytidine for 1 week, the cells showed multinucleation. On the second week, the cells formed stick-like structures. The cells showed extensive cytoplasmic striations in the third week. Finally, in the fourth week, the cells formed myotube-like structures. Immunohistochemical staining of cells of the 5-azacytidine-treated group revealed a positive immune reaction for desmin and cardiac troponin-T. Ultrastructural examination of the 5-azacytidine-treated group revealed that the cells were elongated with central oval large nuclei. The mitochondria were elongated with well developed cristae. There were abundant free ribosomes and extensive dilated rough endoplasmic reticulum. Myofibrils started to appear in the peripheral part of the cytoplasm and T-tubules appeared. Conclusion MSCs can be differentiated in vitro by 5-azacytidine into cardiomyogenic cells, which are important for repairing infracted myocardium.

Mortes súbitas em bovinos causadas por Amorimia exotropica (Malpighiaceae) no Rio Grande do Sul

Descrevem-se casos de morte súbita em bovinos associados com a ingestão de Amorimia (Mascagnia) exotropica em seis propriedades rurais localizadas na região metropolitana de Porto Alegre e na serra gaúcha. Os bovinos intoxicados foram encontrados mortos sem história de sinais clínicos prévios, ou apresentaram tremores musculares, quedas bruscas, movimentos de pedalagem, opistótono, respiração ofegante e decúbito lateral, quando induzidos ao movimento poucos minutos antes da morte. Registrou-se maior número de casos entre os meses de maio e agosto. Nove bovinos foram necropsiados e os principais achados macroscópicos observados foram mucosa oral levemente cianótica (3/9), hidropericárdio leve a moderado (3/9), petéquias e equimoses no epicárdio (5/9), coágulo no interior do ventrículo esquerdo (4/9), edema pulmonar (5/9) e mucosas vermelhas no abomaso e no intestino delgado (6/9). Histologicamente havia necrose de coagulação no miocárdio (9/9) caracterizada por retração celular, aumento da eosinofilia do citoplasma com perda das estriações, vacúolos intracitoplasmáticos, núcleos em picnose, vacúolos intranucleares com marginalização da cromatina e ocasionais núcleos em cariorrexia e cariólise. No coração, edema intersticial (3/9) e infiltrado inflamatório intersticial predominantemente mononuclear (7/9) também foram observados. Nos rins de três bovinos havia degeneração hidrópico-vacuolar multifocal das células epiteliais dos túbulos contorcidos distais associada com núcleos picnóticos deslocados para periferia da célula.

Vaccine-associated Rhabdomyosarcoma with Spinal Epidural Invasion and Pulmonary Metastasis in a Cat

A 7-year-old, female, domestic medium-haired cat had a recurrent deep dermal mass in the interscapular region after initial surgical removal 3 months earlier. The cat had received a killed rabies vaccine and a five-in-one vaccine in the same area about 2 months prior to the first surgery. The relapsed mass was diagnosed as vaccine-associated sarcoma. The cat was euthanized 2 months later because of hind limb paralysis. At necropsy, multiple, poorly demarcated, nodular masses were seen in the muscles around the shoulders, neck, and thoracic vertebrae. Pulmonary metastasis and spinal epidural invasion at T1-T3 with regional cord compression and malacia were observed. Microscopically, the masses consisted of interwoven bundles of spindle cells with prominent multinucleated giant cell formation. The neoplastic cells stained strongly positive for myoglobin, and moderately but variably positive for vimentin, desmin, and alpha- smooth muscle actin. Phosphotungstic acid-hematoxylin staining revealed cytoplasmic striations in scattered tumor cells. The tumor was considered a vaccine-associated rhabdomyosarcoma.

Ischemic preconditioning triggers tyrosine kinase signaling: a potential role for MAPKAP kinase 2.

Myocardial adaptation to ischemia has been shown to activate protein tyrosine kinase, potentiating activation of phospholipase D, which leads to the stimulation of mitogen-activated protein (MAP) kinases and MAP kinase-activated protein (MAPKAP) kinase 2. The present study sought to further examine the signal transduction pathway for the MAPKAP kinase 2 activation during ischemic adaptation. Isolated perfused rat hearts were adapted to ischemic stress by repeated ischemia and reperfusion. Hearts were pretreated with genistein to block tyrosine kinase, whereas SB-203580 was used to inhibit p38 MAP kinases. Western blot analysis demonstrated that p38 MAP kinase is phosphorylated during ischemic stress adaptation. Phosphorylation of p38 MAP kinase was blocked by genistein, suggesting that activation of p38 MAP kinase during ischemic adaptation is mediated by a tyrosine kinase signaling pathway. MAPKAP kinase 2 was estimated by following in vitro phosphorylation with recombinant human heat shock protein 27 as specific substrate for MAPKAP kinase 2. Again, both genistein and SB-203580 blocked the activation of MAPKAP kinase 2 during myocardial adaptation to ischemia. Immunofluorescence microscopy with anti-p38-antibody revealed that p38 MAP kinase is primarily localized in perinuclear regions. p38 MAP kinase moves to the nucleus after ischemic stress adaptation. After ischemia and reperfusion, cytoplasmic striations in the myocytes become obvious, indicating translocation of p38 MAP kinase from nucleus to cytoplasm. Corroborating these results, myocardial adaptation to ischemia improved the left ventricular functions and reduced myocardial infarction that were reversed by blocking either tyrosine kinase or p38 MAP kinase. These results demonstrate that myocardial adaptation to ischemia triggers a tyrosine kinase-regulated signaling pathway, leading to the translocation and activation of p38 MAP kinase and implicating a role for MAPKAP kinase 2.

ADRENOLEUKODYSTROPHY

The patient was a 27‐year‐old man who developed spastic quadriplegia and cerebral disorders. Initial signs were gait disturbance, spastic paraplegia, and sphincter disturbance; these occurred when he was 21. Upon autopsy, the white matter of the brain and spinal cord showed diffuse demyellnation, and the adrenal glands and right testis were atrophic. Cytoplasmic striations seen by light microscopy and trilamellar inclusions seen by electron microscopy were found in ballooned adrenocortical cells. Trilamellar inclusions were also observed in macrophages of the affected cerebral white matter. Biochemical analysis disclosed a high ratio (0.27) of hexacosanoic acid (C26:0) to docosanoic acid (C22: 0) in cerebrosides and sulfatides of the cerebrum. The histological features as well as the result of biochemical analysis were those of classical adrenoleukodystrophy. However, the time of the onset of clinical signs and the duration of the disease were different in the present case from classical adrenoleukodystrophy. The case presented here was diagnosed as adrenoleu‐komyeloneuropathy, which is a variant of adrenoleukodystrophy.

Histochemical and ultrastructural study of Gaucher cells.

Findings are presented of the histochemical and electron microscopical studies of several bioptic specimens of a juvenile form of Gaucher's disease. The storage was restricted to the macrophages with the exception of occasional hepatocytes in which structures closely resembling the storage tubules were found. The cytoplasmic striations of GC were found to be composed both of lipid and a glycoprotein components which can be easily dissociated from each other by means of either organic solvent extraction or proteolytic digestion. According to the results obtained it is the glycoprotein component which is mainly responsible for the cytoplasmic striations. On the contrary the majority of the tubular storage material of the Krabbe cells was found to be removed with chloroform methanol. Results of the enzyme histochemical study (hydrolases and dehydrogenases) point to the considerably higher overall metabolic activity of GC when compared to the Niemann-Pick storage macrophages.

The ultrastructure of rhabdomyosarcoma.

The ultrastructural features of one embryonal and two pleomorphic rhabdomyosarcomas in adults are described. The presence of thick myofilaments in formations suggesting sarcomeres and a rare arrangement of mitochondria in tandem allow for identification of the spindle cells in embryonal rhabdomyosarcoma as skeletal muscle cells. Aggregates of similar filaments could be detected in cells comprising alveolated areas and those of the pleomorphic rhabdomyosarcomas, although the sarcomere-like arrangement was less conspicuous. Cells of both histologic types contained cytoplasmic rods of electron-dense material and abundant, dilated, coarse, endoplasmic reticulum. The former resembled the bodies found in nemaline myopathy but lacked the internal periodic bands of such structures. Changes in endoplasmic reticulum were most pronounced in cells comprising the pleomorphic rhabdomyosarcomas, and frequently the dilated cisterns contained homogeneous or vacuolated electrondense material. Intranuclear inclusions frequently observed in cells of pleomorphic rhabdomyosarcoma were demonstrated to be portions of entrapped cytoplasm. Electron microscopic examination can support a diagnosis of rhabdomyosarcoma in certain cases of malignant mesenchymal neoplasms which have recognizable diagnostic features except that cytoplasmic striations are not seen. Contrary to the impression given by light microscopy, spindle cells comprising embryonal rhabdomyosarcoma appear better differentiated than those of alveolar or pleomorphic forms.

Embryonal rhabdomyosarcoma of the oral soft tissues

A clinicopathologic study of eleven cases of histologically confirmed embryonal rhabdomyosarcoma of the oral soft tissues is presented. The patients were principally in the younger age groups, and the tumor most often presented as a painless mass. Such symptoms as pain, dysphonia, dysphagia, trismus, and physical debilitation usually were identified with later stages of the disease. The gross specimens exhibited no characteristic feature by which a diagnosis could be made. Although composed of a variety of cell types and patterns, this tumor has certain histologic features related to cell morphology and staining characteristics which allow a positive diagnosis; however, the presence of striations in tumor cells, although helpful in diagnosis, is not to be considered a sine qua non. Six tumors in this series exhibited cytoplasmic striations. The embryonal rhabdomyosarcoma may be markedly radiosensitive, and radiation therapy can be a most effective adjunct to surgical treatment.

PHASE CINEMICROGRAPHIC OBSERVATIONS ON CULTURED CELLS. II. MASS MOVEMENT OF CYTOPLASM IN EUPHORBIA MARGINATA

Mass movement is a form of streaming in which distinct quantities of cytoplasm flow as entities along a transvacuolar strand or cytoplasmic striations of the peripheral cytoplasm. An individual mass can move at variable velocities during a brief period of time or change its direction of flow. Two masses, when moving at different velocities in the same or different directions along a strand, can be observed to collide. This can occur repeatedly, resulting in the formation of a mass of considerable size. Many organelles can be observed to move at velocities differing from that of the mass; some can be observed to change directions during their movement. A mass may represent a dilation of one or more microstreams within the cytoplasm. Folding of the microstreams within a mass may explain the changes in the direction of movement observed for some organelles. Several levels of movement are associated with streaming, including those of the ground plasm, of the organelles, of the transvacuolar strands and of the cytoplasm masses. These, and possibly more subtle aspects of the streaming phenomenon, must be incorporated into any theory of streaming.