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211.
212.
Kyozo Takahashi 《Cell and tissue research》1967,83(1):70-75
Summary Somatic spine synapses modified with postsynaptic electron opaque materials were found in the axo-somatic ciliary ganglion synapse of the chick.A part of the postsynaptic cell body protrudes into the presynaptic calyciform ending as a somatic spine with about 1 in length and 0.15 in diameter, and forms the so-called synaptic complex with presynaptic process. Moreover, conspicuous electron opaque materials can be seen in the central axis of the spine, except for its end portion. Sometimes, these opaque materials are seen as arrayed dots.The morphological characteristics of the somatic spine synapses in this study are quite similar to that found in the habenula and interpeduncular nuclei of the cat (Milhaud and Pappas, 1966). the biological significance of which is obscure at present.This work was supported in part by grant from the Education Ministry of Japan. 相似文献
213.
Joint transfer of genetic markers in Bacillus subtilis 总被引:7,自引:2,他引:5
I Takahashi 《Journal of bacteriology》1966,91(1):101-105
Takahashi, I. (McMaster University, Hamilton, Ontario, Canada). Joint transfer of genetic markers in Bacillus subtilis. J. Bacteriol. 91:101-105. 1966.-To compare the processes of genetic incorporation in transduction and transformation in Bacillus subtilis, several groups of linked markers were selected and the degree of linkage was determined by the two means of genetic exchange. Bacteriophage PBS 1 was used in transduction experiments. In all cases, frequencies of joint transfer, as expressed by the cotransfer index or by percentage of joint transfer, were higher in transduction than in transformation. With a pair of closely linked markers, the frequency of joint transduction was only slightly higher than that of joint transformation. On the other hand, a considerably higher degree of linkage was obtained by transduction when loosely linked markers were examined. It appears that the size of donor chromosome transferred by transducing phage particles is much larger than that incorporated by recipient cells in transformation. It is suggested that transduction in B. subtilis may be a useful tool in extending further the linkage groups established by the transformation technique. 相似文献
214.
Y. Ohtsuki T. Yamaguchi H. Sonobe K. Takahashi K. Hayashi A. Takenaka H. Hashimoto K. Kuwabara T. Miyamoto N. Terao 《Biotechnic & histochemistry》1989,64(2):55-59
A new simplified method has been devised for staining aluminum and has been tested in paraffin sections of bone from 60 patients who have undergone hemodialysis. Iliac crest bone fragments were fixed in 20% phosphate-buffered formalin for less than a day and demineralized at room temperature in 10% phosphate-buffered formalin containing 5% formic acid for only 2 to 3 hr. Four-micron paraffin sections, accompanied by positive controls, were stained with Maloney's aluminum stain, the Berlin blue reaction for iron, dylon or Congo red for amyloid and von Kossa's reaction for calcium. Aluminum and iron were demonstrated particularly at the mineralizing front of bony tissues; aluminum in 52 cases, iron in 45. Dylon staining also gave positive results in 52 cases. It is important in determining whether aluminum deposition is present that the von Kossa reaction remains positive even after demineralization. This method may be more useful for demonstrating aluminum in bony tissues than the complicated and time-consuming resin-embedding method currently used. 相似文献
215.
216.
217.
K Osanai K Takahashi S Sato K Iwabuchi K Ohtake M Sata S Yasui 《Journal of applied physiology》1991,70(3):1300-1308
We investigated whether alveolar surface force increased and participated in the lung pressure-volume relationship in bleomycin-induced pulmonary fibrosis in hamsters and, if so, whether lung surfactant was hampered in the lungs. On the air-filled pressure-volume curve, decreases of lung volume from control level were significantly higher at 3-8 cmH2O pressure on day 10 than on day 30. Because the change of lung tissue elasticity evaluated from the saline-filled pressure-volume curve was equal for the 2 days, the higher decrease of air volume on day 10 was due primarily to contribution of alveolar surface force. Pressure differences between deflation limbs of air-filled and saline-filled pressure-volume curves, which represented net alveolar surface force, were significantly higher at any lung volume between 50 and 90% total lung capacity on day 10, but almost no significance was observed on day 30. Phospholipid concentration in bronchoalveolar lavage fluid significantly decreased on day 10 but had improved by day 30. Analysis of phospholipid species in purified lung surfactant showed decreased fractions of disaturated phosphatidylcholine and phosphatidylglycerol on day 10. Surface-active properties of the surfactant, measured by a modified Wilhelmy balance, were remarkably hampered on day 10, but most of them had improved by day 30. We consider that the quantitative and functional abnormalities of lung surfactant have a part in the aggravation of lung mechanics in the acute phase of pulmonary fibrosis. 相似文献
218.
Survival of cultured cells and somatic embryos of Asparagus officinalis cryopreserved by vitrification 总被引:2,自引:0,他引:2
Cultured cells and somatic embryos derived from the mesophyll tissue of asparagus (Asparagus officinalis L.) were cryopreserved by vitrification. The vitrification solution (PVS) contains (w/v) 22% glycerol, 15% ethylene glycol, 15% propylene glycol and 7% DMSO in Murashige-Skoog medium enriched with 0.5M sorbitol. After initial cryoprotection with sorbitol supplemented MS medium containing 12% ethylene glycol, cells or embryos were exposed stepwise to 85% PVS at 0°C. They were loaded into 0.5 ml transparent straws, and were then plunged directly into liquid nitrogen. After rapid warming, PVS was removed and diluted stepwise. The highest survivals of vitrified cells and embryos were about 65 and 50%, respectively. Surviving embryos developed into plantlets.Abbreviations DMSO
dimetyl sulfoxide
- PVS
vitrification solution
- LN
liquid nitrogen
- DSC
differential scanning calorimeter
- MS
Murashige-Skoog salt medium
- NAA
naphthalene acetic acid
- BA
6-benzyladenine 相似文献
219.
Masamichi Takahashi 《Journal of plant research》1989,102(2):219-234
Development of the echinate pollen grains inFarfugium (Compositae: Senecioneae) has been studied by a combination of transmission electron microscopy and field emission scanning
electron microscopy with a freeze fractured method. The inner surface of the callose wall surrounding each microspore does
not possess an echinate pattern before primexine deposition begins. The primexine formation coincides with the initiation
of spines. The freeze fractured primexine shows probacula which form transverse rods. The developing exine has an inner spongy
substructure. The endexine is formed by the accumulation of the electron dense lamellae with white lines after the dissolution
of the callose wall. In the present study, it is confirmed that the developmental process of pollen formation revealed in
the field emission scanning electron microscope is consistent with the results obtained using the transmission electron microscope. 相似文献
220.
T. Tsuto H. L. Obata-Tsuto N. Iwai T. Takahashi Y. Ibata 《Histochemistry and cell biology》1989,93(1):1-8
Summary The fine structure of neuronal perikarya and processes containing VIP-like immunoreactive material in the colon of patients with Hirschsprung's disease was investigated by immunoelectron microscopy. No VIP-like immunoreactive terminals were found in Auerbach's plexus of the ganglionic segment. However, VIP-like immunoreactive preterminal axons were frequently found to make synaptic contact with both immunoreactive and non-immunoreactive elements within Meissner's plexus. Therefore, the function of the VIP neurons in Auerbach's plexus seems to differ from that in Meissner's plexus. In the oligoganglionic segment, there were a few VIP-like immunoreactive processes, but no VIP-like immunoreactive synaptic formations. VIP-like immunoreactive processes were rarely encountered in the aganglionic segment. In both the oligo-and aganglionic segments, bowel relaxation is considered to be disturbed due to the lack of synaptic contacts of VIP-like immunoreactive neurons with other neuronal components.This work was supported in part by a grant (no. 57370002) from the Ministry of Education, Science and Culture, Japan 相似文献