The ultrastructural changes of mitochondria in the ovarian oocytes from Graafian follicles, the ovulated tubal ova, and the various stages of preimplantation rabbit embryos have been observed with an electron microscope. From the ovarian oocytes to the 4-cell stage, mitochondria showed oval and round forms with a few cristae arranged concentrically and peripherally at the inner membrane. In 8-cell and 16-cell stages, mitochondria tended to change their forms to be elongated, and their sizes, and the outer membrane of the mitochondria had a tendency to become rough and irregular although there were few changes in the inner structure. In morula, some mitochondria began to show several transverse cristae proceeding into the matrix. Mitochondria rapidly increased in number at the late blastocyst stage. Matrix of mitochondria with transverse cristae found in the morula and in blastocyst stages was less dense than that of the earlier stages. The authors believe that the morphological changes of mitochondria during early embryonal development indicate the level of enzymatic activity at which this organelle is engaged in energy metabolism.
Animal ; Cell Membrane/ultrastructure ; Embryo/ultrastructure* ; Embryo Implantation ; Female ; Microscopy, Electron ; Mitochondria/ultrastructure* ; Organoids/ultrastructure ; Ovum/ultrastructure ; Rabbits

This study was performed to investigate the sequential changes of the retinal tissue in tissue culture condition. The human sensory retinal tissues were cultured for up to 2 weeks and 4 weeks, respectively. The initial changes showed the separation of the intercellular space and the consequent widening of the intercellular space with prolapse of cytoplasmic processes into the widened intercellular space. The internal limiting membrane was also separated from the inner retina, which led to the prolapse of the cytoplasm of the Muller cell. The growth of the Muller cell was most prominent during the 4-weeks' tissue culture period. These findings suggest that the Muller cell might contribute to the formation of cellular membrane in case of the defect of the internal limiting membrane in several pathologic conditions.
Adult ; Cell Membrane/ultrastructure ; Cells, Cultured ; Humans ; Male ; Middle Aged ; Neuroglia/*ultrastructure ; Retina/*ultrastructure

OBJECTIVEIt is well known that glioma stem cells-progenitors (GSCP) proliferate indefinitely and hardly differentiate in vitro, however, the reasons remain unknown. The aim of this study was to explore the ultrastructural basis of GSCP.

METHODSGSCP, kept by our laboratory, were collected, embedded, and cut into ultrathin sections and observed under the transmission electron microscope.

RESULTSA single GSCP usually had relatively well developed mitochondria, Golgi apparatuses, ribosomes, and undeveloped rough endoplasmic reticulum, but seldom lysosomes and no typical autophagosomes were found, and the nuclear-cytoplasmic ratio was high. The nuclei frequently contained huge amounts of euchromatin and a small quantity of heterochromatin, and in most nuclei there were only one nucleolus, however, two or more nucleoli were also common. Typical apoptotic cells could hardly be found in tumor-spheres, and between neighboring cells in tumor-spheres there were incompletely developed desmosomes or intermediate junction.

CONCLUSIONThe ultrastructural features of glioma stem cells-progenitors showed that BTSCP were very primitive and the lack of autophagy and the underdevelopment of some other cellular organelles are probably the reasons for the differential inhibition of GSCPs.

Brain Neoplasms ; ultrastructure ; Cell Line, Tumor ; Cell Membrane ; ultrastructure ; Cell Nucleus ; ultrastructure ; Chromatin ; ultrastructure ; Cytoplasm ; ultrastructure ; Glioma ; ultrastructure ; Humans ; Intercellular Junctions ; ultrastructure ; Microscopy, Electron, Transmission ; Mitochondria ; ultrastructure ; Neoplastic Stem Cells ; ultrastructure

In these years, the electrical technology is widely applied in the study of biomedical engineering. Using electroporation therapy (EPT) to treat tumor is associated with biomedical engineering, electrical new technology, computer technology and microelectronic technology, which is a new marginal subject. Many experts have studied the mechanism and clinical treatment of the cell membrane electroporation phenomenon under electrical fields. These researches have shown that the membrane electroporation can stimulate the transport and intake of various drugs, which improves the tumoricidal effect of these drugs. The researchers have also been exploring the phenomenon that irreversible electrical breakdown (IREB) of cell membrane under high electrical fields and steep pulses leads to the death of tumor.
Cell Membrane ; ultrastructure ; Electrochemotherapy ; Humans ; Neoplasms ; drug therapy ; Research ; trends

OBJECTIVE: To observe changes on cell membrane in blood cells after they were been electrified. METHODS: Blood were electrified for 5, 10, 20, 30 s, 1 min respectively, and Scanning electron microscope was used to detect the changes on their cell membranes. RESULTS: Pores were detected both on electrified erythrocytes and leukocytes with round or ellipse shapes. The erythrocytes often have one or more pores while the leukocytes often have more pores looked like cribble. The rates of perforated cells were increased with the prolonging time of electrification, 5 s with 6% and 1 min increased to 40%. CONCLUSIONS Alternating current can cause the cell perforating, and the rates of perforated cell were increased with the prolonging time of electrification.
Adult ; Blood Cell Count ; Cell Membrane/ultrastructure* ; Cell Membrane Permeability ; Electroporation/methods* ; Erythrocytes/ultrastructure* ; Female ; Humans ; In Vitro Techniques ; Leukocytes/ultrastructure* ; Male ; Microscopy, Electron, Scanning ; Middle Aged ; Young Adult

OBJECTIVETo investigate damages to the quality of boar sperm frozen in 5 ml straws, pellet and 0.25 ml straws as well as the ultrastructural changes of frozen boar sperm in 5 ml straws.

METHODSWe compared 3 different freezing packages of 5 ml straws, pellet and 0.25 ml straws to determine their effects on frozen boar semen, and observed the morphological and ultrastructural changes of the boar sperm in the 5 ml straws using scanning electron microscopy.

RESULTSIn the 5 ml straws, the vitality and motility of the boar sperm after freezing were not significantly different from those in the other two formulations, the normal apical ridge (NAR) was 52.65%, higher than in the pellet but not significantly different from that in the 0.25 ml straws, and the sperm membranes were mostly bubbly, some locally broken, which indicated the damage induced by freezing and thawing.

CONCLUSIONAt the present time, boar semen frozen in 5 ml straws were not significantly different from those frozen in 0.25 ml straws. The existing freezing-thawing method may cause certain damage to the quality and ultrastructure of boar sperm, and therefore needs to be further improved.

Acrosome ; ultrastructure ; Animals ; Cell Membrane ; ultrastructure ; Cryopreservation ; methods ; Male ; Microscopy, Electron, Scanning ; Semen Preservation ; methods ; Spermatozoa ; ultrastructure ; Swine

Atomic force microscopy (AFM) is an emerging technique for a variety of uses involving the analysis of cells. AFM is widely applied to obtain information about both cellular structural and subcellular events. In particular, a variety of investigations into membrane proteins and microfilaments were performed with AFM. Here, we introduce applications of AFM to molecular imaging of membrane proteins, and various approaches for observation and identification of intracellular microfilaments at the molecular level. These approaches can contribute to many applications of AFM in cell imaging.
Cell Membrane/ultrastructure ; Membrane Proteins/*physiology ; Microfilaments/*physiology ; *Microscopy, Atomic Force ; Molecular Imaging/*methods

A sub-microsecond pulse generation applied for electroporation effects of tumor cell is presented in this paper. The principle of the generator is that the expected pulse waveform is intercepted from the RC discharge curve by controlling the on-off states of two IGBT modules with a synchronous controller. Experimental tests indicate that the generator can produce adjustable pulse waveform parameters with 0.5-3.5kV amplitude, 300-800 ns pulse duration, 1-400Hz repetition frequency rate, and it is suitable for the study of the electroporation effect experiments.
Animals ; Cell Line, Tumor ; Cell Membrane ; Electricity ; Electroporation ; instrumentation ; methods ; Equipment Design ; Microtechnology ; instrumentation ; Neoplasms ; ultrastructure

OBJECTIVETo observe the changes of L929 cell membrane with atomic force microscope (AFM) after infrasound exposure and to explore the mechanisms of effect of infrasound on cell membrane.

METHODSAfter primary culture, the L929 cells were exposed to infrasound with intensity output of 130 dB and frequency of 16 Hz 2 hours each day for 3 days. The subsequent changes in the membrane of the control cells and the cells exposed to the infrasound were determined by nano-scale scanning with AFM.

RESULTSAfter infrasound exposure, the normal prominence of the membrane became short and the dent became shallow in the 7.5 microm x 7.5 microm and 4.0 microm x 4.0 microm photographs. The prominence appeared as cobblestones. The surface of the membrane became smooth.

CONCLUSIONThe membrane structure of the L929 cells can be changed by infrasound exposure with intensity of 130 dB and frequency of 16 Hz. The change might be one of the characteristics of effect of infrasound on cell membrane.

Animals ; Cell Membrane ; radiation effects ; ultrastructure ; Cells, Cultured ; Fibroblasts ; radiation effects ; ultrastructure ; Mice ; Microscopy, Atomic Force ; Sound ; adverse effects

Though there is ongoing public concern on potential hazards and risk of electromagnetic radiation, the bioeffects mechanism of electromagnetic fields remains obscure. Heart is one of the organs susceptive to electromagnetic fields (EMF). This study was designed to assess the influence of high power pulse microwave and electromagnetic pulse irradiation on cardiomyocytes, to explore the critical mechanism of electromagnetic fields, and to explain the regular course of injury caused by exposure to pulse EMF. Cultured cardiomyocytes were irradiated by high power pulse microwave and electromagnetic pulse first, then a series of apparatus including atom force microscope, laser scanning confocal microscope and flow cytometer were used to examine the changes of cell membrane conformation, structure and function. After irradiation, the cardiomyocytes pulsated slower or stop, the cells conformation was abnormal, the cells viability declined, and the percentage of apoptosis and necrosis increased significantly (P< 0.01). The cell membrane had pores unequal in size, and lost its penetration character. The concentration of Na+, K+, Ca2+, Cl-, Mg2+, Ca2+ and P3+ in cell culture medium increased significantly (P< 0.01). and the concentration of Ca2+ in cells ([Ca2+]i) decreased significantly (P<0.01). The results indicated that cardiomyocytes are susceptible to non-ionizing radiation. Pulse electromagnetic field can induce cardiomyocytes electroporation, and can do great damage to cells conformation, structure and function. Electroporation is one of the most critical mechanisms to explain the athermal effects of electromagnetic radiation.
Animals ; Animals, Newborn ; Cell Membrane ; ultrastructure ; Cell Membrane Permeability ; radiation effects ; Cells, Cultured ; Electromagnetic Fields ; adverse effects ; Electroporation ; Mice ; Microwaves ; adverse effects ; Myocytes, Cardiac ; cytology ; radiation effects ; ultrastructure