Morphologically Changed Research Articles

Effects of ion beam irradiation on the regeneration and morphology of Ficus thunbergii Maxim

Shoot explants cut from aseptically grown Ficus thunbergii plants were irradiated with 12 C 5� , 12 C 6� and 4 He 2� ion beams of 10 to 200 Gray (Gy). After irradiation, the explants were allowed to regenerate. The regeneration frequency (RF), or percent explants bearing regenerated shoots to the total number of explants irradiated, decreased in a dose- dependent manner. Morphological changes in leaves and stems were observed in regenerants. The morphological change frequency (MF), or percent regenerants bearing morphologically changed shoots to the total number of regenerants peaked at 15 to 25% at the dose of each ion beam that gave an RF of about 80% (except for 4 He 2� ). A negative correlation was observed between the linear energy transfer (LET) and ion beam dose both in RF and MF. The present results strongly suggest that ion beam irradiation can induce mutations in the genome of F. thu nbergii.

Induction of Morphologically Changed Petals from Mutagen-treated Apical Buds of Rose and Plant Regeneration from Varied Petal-derived Calli.

The apical buds of lateral branches asexually multiplied by cutting were treated with some chemical mutagens, and the growth and differentiation or morphological changes of the mutagen-treated buds were traced in developed flowers. As a result, the variations in size, shape, color and number of petals were detected most frequently in the flowers that were developed from apical buds treated with N-methyl-N'-nitro-N-nitrosoguanidine at 100μg ml-1. The variant petals were cultured on MS medium supplemented with NAA and BAP for in vitro isolation and multiplication of morphologically altered rose plants. Embryogenic calli were obtained via adventitious roots induced from the petals and successfully differentiated to intact plants. Consequently, the regenerated plants produced the varied flower different from that originally used for tissue culture. Thus, the present study suggested that our approach would provide an effective method for easily and rapidly inducing variations in flowers of rose and for in vitro multiplication of their regenerants.

Morphological changes of retinal pigment epithelial and glial cells at the site of experimental retinal holes

To investigate morphological changes of retinal pigment epithelial (RPE) cells and glial cells in the immediate and early phases of restoration at the site of experimental retinal holes. We made 0.2-disc-diameter retinal holes with a vitreous cutter in albino rabbit eyes. To assess very early changes of RPE cells, the eyes were enucleated at 0,1,3, and 5 h postoperatively and observed by scanning electron microscopy (SEM). At 1,5, and 7 days after surgery, eyes were enucleated and prepared in thin and ultra-thin sections for observation by light and transmission electron microscopy (TEM). SEM showed the surface of the RPE cells lifting a few hours after surgery at the site of the retinal holes. The tissue filling the retinal hole was amorphous and homogeneous, as viewed by light microscopy. TEM revealed that this tissue consisted of glial cell processes containing many organelles. In addition, the cytoplasm of the cells was relatively dark, while the surface of the filling tissue continued smoothly to the internal limiting membrane. These findings suggested that these cell processes were parts of Müller cells. RPE cells and glial cells assembling at the site of the retinal hole may play an important role in retinal hole closure in this experimental model. In addition, RPE cells were morphologically changed in an immediate phase of restoration.

Effects of vinblastine on cell membrane fluidity and the growth of SA-1 tumor in mice

Cell membranes can be targets of some anti-cancer drugs. Therefore, the purpose of this study was to determine whether vinblastine (VLB) can also affect the tumor cell membrane. On the in vivo SA-1 tumor model, alteration of cell membrane fluidity (measured by electron paramagnetic resonance, EPR), cytotoxicity and morphological changes of the SA-1 tumor cells after VLB treatment were studied. The cytotoxic effect of VLB was biphasic, with an initial fast increase in cytotoxicity followed by a plateau. The surviving cells had increased membrane fluidity and were morphologically changed. The dose-response curve of VLB on membrane fluidity was also biphasic with an initial fast increase in membrane fluidity followed by a plateau. Since dose-response curves of VLB cytotoxicity and its effect on membrane fluidity were similar, there was a high correlation between both effects. The effect of VLB on membrane fluidity was the most pronounced at 24 h and 48 h after treatment. The results of this study indicate that VLB affects cell membrane by increasing the membrane fluidity of SA-1 tumor cells in vivo in a dose- and time-dependent manner. Therefore, this finding may be beneficially implemented also in priming cells for other cytotoxic drugs and for appropriate timing of drug sequence in combined schedules.

Effects of vitamin D3 and related compounds on angiotensin converting enzyme activity of endothelial cells and on release of plasminogen activator from them.

Subculture of bovine endothelial cells with 33 μm vitamin D3 or 25-(OH)-D3 for 48 h caused marked morphological change. Angiotensin converting enzyme (ACE) activity of the morphologically changed cells was decreased to approximately one-third and plasminogen activator (PA) activity released from them increased approximately 12-fold as compared to the control cells. Fibrin autography revealed both urokinase-type (53kDa) and tissue-type (80kDa) PAs in the culture medium of the cells treated with vitamin D3 Neither 1, 25-(OH) 2-D3 nor 24, 25-(OH) 2-D3 had any effect on PA activity released from the cells, while ACE activity of the cells was decreased by the treatment with these dihydroxylated vitamins. Provitamin D3 or cholesterol had no effect on PA or ACE activities of endothelial cells.

Morphological changes in trichostrongylid eggs after treatment with fenbendazole

The influence of daily doses of 0.05–0.1 mg fenbendazole/kg body weight on egg development was tested in twenty-seven lambs artificially infected with Haemonchus contortus plus Trichostrongylus colubriformis or Ostertagia circumcincta, as well as in two additional sheep naturally infected with Nematodirus spp. Atypical eggs were detected before a reduction in the number of eggs. Atypical eggs had blastomeres of different sizes and shapes; knot-like, crater-like or bubble-like. In isolated cases eggs with atypical first larvae were recognizable. Morphologically changed eggs occurred in the reproductive organs of female O. circumcincta worms. None, or only a very small number of third stage larvae, could be cultured from the faeces of treated sheep.

三叉神経節に関する実験的研究

Pulp exposure and application of arsenious acid were experimentally made in the mandibular first molars of rats and histo-pathological investigations were made of their respective effect on the trigeminal ganglion cells and of the changes in the nerve fibers of the pulp in the two experiments. The results were as follows : 1. In the exposed-pulp group, necrosis occurred in the pulp surface layer on the first day after pulp exposure and progressed with time thereafter. The necrosed tisuses extended nearly to the apical foramen on the 14th day after pulp exposure. Thereafter, formation of abscess in the apical periodontium was observed. 2. With the development of the foregoing necrosed tissues, the nerve fibers of the pulp gradually repeated degeneration and resolution and disappeared. 3. In the exposed-pulp group, ganglion cells indicative of displacement of the nuclei and disappearance and irregularity of Nissle substance were observed in the trigeminal ganglion in the operated side. Quantitative observations showed an increase with time in the proportion of the ganglion cells until the 14th day after pulp exposure and a decreasing tendency thereafter. 4. In the arsenious acid application group, destruction of the pulpal blood vessels and disturbance of the circulation were recognized from the first day after application. Although no significant changes in the pulp cells were observed at this time, the pulp tissues were found destroyed with time. 5. In the arsenious acid application group, collapsed images of the nerve fibers were recognized as early as on the first day after application. In the chronolngical findings also, nearly all the pulpal nerve fibers were found destroyed. 6. In the arsenious acid application group also, ganglion cells indicative of the similar findings as those observed in the exposed-pulp group were recognized in the trigeminal ganglion in the operated side. Quantitatively, the proportion of the ganglion cells increased on the 3rd and/or the 7th day after application and decreased thereafter. 7. Morphological changes in the trigeminal ganglion cells occurred relatively early in the arsenious acid application group and about a week later in the exposed-pulp group. 8. On the basis of the observation results of the nerve fibers in the experiment site and the trigeminal ganglion cells, the quantitative changes on the prefixed days of the trigeminal ganglion cells which were morphologically changed approximately correspond with the changes in the nerve fibers in the experiment site.

Senescent human diploid cells (WI-38): Attempted induction of proliferation by infection with SV40 and by fusion with irradiated continuous cell lines

When proliferating WI-38 cells (phase II and early phase III) were infected with the Simian papovavirus SV40, or fused with lethally irradiated cells of the continuous line VA13 (containing the SV40 genome), they underwent morphological changes, showed accelerated proliferation and subsequently ceased proliferation (crisis). Senescent WI-38 cells maintained for weeks after the termination of proliferation (late phase III), however, showed neither accelerated proliferation, nor morphological changes by infection or by fusion. Proliferating WI-38 cells fused with lethally irradiated cells of several continuous cell lines, such as HeLa, did not produce continuously proliferating cell lineages. Genes responsible for the morphological changes do not appear to be responsible for the property of continuous proliferation. The crisis of morphologically changed cells appears to be equivalent to the senescent state (late phase III) of normal human diploid cells.

Cytological studies of the effect on cancerous pleuro peritoneal fluid by cancer chemotherapy

The purpose of this subject is the correlation between the clinical effect and the cancer cell damage of the anticancer drugs injected into the pleural and peritoneal cavity of the patients.Anticancer drugs, such as MMC and Endoxan, were directly injected into the pleural and perito neal cavity of 17 patients with cancerous pleuritis or peritonitis more than three times.The cells in pleuroperitoneal fluid were compared to the clinical effect. The injections of the anticancer drugs were clinically effective in five cases. The number of cancer cells per volume unit decreased remarkably in four of them, though the other case didn't reveal a noticeable change of cell count. However, in five of 12 cases clinically ine ffective, the number of cancer cells per volume unit decreased as in the effective cases. But no remarkable decrease of cell count was observed in the other 7 cases.In most cases of the group whose cancer cell count decreased, the cell number began to drop after giving small doses of anticancer drugs.The morphological changes of the cancer cells, by anticancer drug infusion, are mostly changes of nuclear chromatin pattern, especially nuclear pycnosis and vacuolation of the cytoplasma.In four of the five cases of the clinically effective group, more than half of cancer cells revealed morpholo gical damages by anticancer drug. In 12 cases of the clinically ineffective group, there were five cases with noticeable morphological cell changes (more than half of the cancer cells), five cases with poor cell changes (less than 20% of the cancer cells) and two cases that showed moderate cell changes.On the relationship between the clinical findings and the increase and decrease of lymphocytes by anticancer drugs infusion, three of the five cases of the clinically effective group revealed increases of lymphocytes though the other two didn't show prominent changes of lymphocytes. In 12 of the clinically noneffective cases, there were no noticeable changes of lymphocytes except for one case.Moreover, five clinically effective cases showed decreases of the number of cancer cells per volume unit, and an increase of morphologically changed cancer cells and an increase of lymphocytes was observed in three of them.In more than half of 12 cases, no notable changes were observed in number of cancer cells, and the ratio of the morphologically stable cancer cells to damaged ones was not influenced. However, some cases showed similar findings to the cells of the effective cases, in the decrease of the number of cancer cells, and the increase of the damaged cancer cells and lymphocytes. In these cases, we would have expected greater improvement of the clinical condition of the patients, if their condition had permitted us to administer a larger dose of the anticancer drugs.