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21.
Effect of RU 486 on luteal function in the early pregnant rat 总被引:1,自引:0,他引:1
T Kawano H Okamura C Tajima K Fukuma H Katabuchi 《Journal of reproduction and fertility》1988,83(1):279-285
A dose of 30 mg RU 486/kg, an antiprogesterone, was administered to pregnant rats on Day 2 (Group 1) or Day 4 (Group 2) of pregnancy. RU 486 significantly changed serum progesterone and oestradiol concentrations and luteal 3 beta-HSD and 20 alpha-HSD activities in Group 1, and implantation was significantly inhibited. The luteal 3 beta-HSD activity in Group 2 rats on Day 6 was significantly (P less than 0.01) lower than the control value (7.5 +/- 0.6 and 10.1 +/- 0.6 mU/mg protein respectively). This decline in the 3 beta-HSD activity was followed by a marked decrease in the serum progesterone concentration, resulting in a significant decrease of the progesterone/oestradiol ratio and implantation was completely inhibited. The 20 alpha-HSD activity, which could not be detected on Day 6 in the control rats, was twice as great in Group 2 than in Group 1 rats (17.5 +/- 1.2 and 7.4 +/- 3.1 mU/mg protein respectively). Ultrastructural examination of corpora lutea of Group 2 rats confirmed luteolysis. These results suggest that RU 486 has a luteolytic effect and its anti-implantation effect is concomitant with luteolysis of the corpora lutea of pregnancy. 相似文献
22.
Akihiro Hara Hiroyuki Hashimoto Hirofumi Morota Hiroshi Harada Hirofumi Uchimiya 《Journal of plant research》1988,101(2):131-140
Tobacco mesophyll protoplasts were treated with plasmids, pCT2 (17.1 kbp) or pCT2T3 (18.3 kbp), which contained a chimeric aminoglycoside phosphotransferase II (APH(3′)II) gene and an intact nopaline synthase gene. Expression of two marker enzymes, APH(3′)II and nopaline synthase, were analyzed in transformed plants. Four out of 16 transformants obtained by pCT2T3 possessed both enzymes. Upon self-pollination, the progeny of one of transformants (T2) segregated to 153∶4 in terms of resistant and susceptible character to kanamycin, suggesting insertion of foreign genes into three independent chromosomes. The kanamycin resistant character in the rest of transformants showed 3∶1 segregation. DNA blot analysis of the T2 transformant and progenies indicated the presence of two marker genes. 相似文献
23.
24.
Summary Cellular differentiation and migration in the fundic glands of adult and larval Xenopus laevis have been examined using bromodeoxyuridine-immunohistochemistry. In the adult fundic gland, cumulative labeling with bromodeoxyuridine revealed a proliferative cell zone between the surface mucous cells and mucous neck cells, in what is referred to as the neck portion of the gland. The labeling-index of mucous neck cells had rapidly increased by week-5. The labeling-index of oxynticopeptic cells showed a more delayed increase until week-7, coincident with the decrease in the labeling of mucous neck cells. In the immature fundic glands of larvae, the labeled proliferating cells were randomly distributed throughout the developing gastric mucosa. During metamorphosis, the labeling-index of immature epithelial cells was highest at stage 63. Following administration of bromodeoxyurdine at this, stage, there was no significant loss of labeled epithelial cells during the metamorphosing period. Furthermore, there was no significant difference in the labeling-indices among the epithelial cells, such as surface mucous cells/generative cells, mucous neck cells, and oxynticopeptic cells, 7 days after administration. Cellular differentiation and migration pathways of epithelial cells in the fundic gland of adult X. laevis and its larvae are discussed. 相似文献
25.
Kiyoshi Takahashi Katsuya Miyatani Hiroyuki Yanai Ho Jong Jeon Kotaro Fujiwara Tadashi Yoshino Kazuhiko Hayashi Tadaatsu Akagi Ken Tsutsui Koichi Mizobuchi 《Virchows Archiv. B, Cell pathology including molecular pathology》1992,62(1):105-113
Monocytic leukemia (MoL) cells were obtained from the peripheral blood of a patient in whom the leukemic cells infiltrating
various lymphoreticular organs exhibited features intermediate between interdigitating reticulum cells (IDC) and ordinary
phagocytic macrophages, whereas the leukemic cells in the peripheral blood were essentially monocytic and lacked such features.
Peripheral blood CD4+ T-cells were established as an interleukin-2-dependent T-cell line. When the MoL cells were exposed
for a few days to conditioned medium from the T-cell line, they extended several dendritic cytoplasmic projections and became
intensely positive for HLA-DR antigen, cytoplasmic S-100β protein, and CD1 antigen. Functionally, the conditioned medium significantly
down-regulated Fc-mediated and Fc-independent phagocytic activities, and the levels of lysosomal enzymes such as lysozyme
and nonspecific esterase in the MoL cells. Moreover, the conditioned medium significantly up-regulated the accessory cell
function of the MoL cells as measured by the primary allogenic mixed leukocyte reaction (MLR). Furthermore, the conditioned
medium significantly down-regulated the expression of CD14 antigen.
Biochemical analysis indicated that the factor responsible for these changes is a protein which is distinct from known human
cytokines and whose molecular weight is approximately 31 kDa. These findings suggest that IDC are closely related the monocytic
lineage and that helper T-cells play an important role in constructing the microenvironment of T-lymphoid tissues which is
necessary for the differentiation and maturation of IDC. 相似文献
26.
Kenji Kato Su-wan Oh Hiroyuki Yamamoto Takayuki Hanazato Ikuko Yasuda Akira Otuki Masayuki Takahashi 《Ecological Research》1992,7(3):267-276
In order to understand the control mechanisms of a large, stable bacterial standing stock, enclosure experiments were conducted
in a eutrophic lake, where both bacterial productivity and grazing pressure were very high. Total bacterial number in the
different enclosures ranged from 1.2 to 2.7×107 cells mL−1 throughout the experiment. The average bacterial cell production rate estimated from a grazer eliminating experiment was
6.3×105 cells mL−1 h−1. Difference in the bacterial cell production rate between shaded and unshaded enclosures was not apparent. Bacteria showed
a reduction in standing stock of only about 25–30% even after the supply of light was cut to 1%. Bacteria in the shaded enclosures
then recovered their production rate in the first 12 days of perturbation. Grazing pressure in the shaded enclosures was not
less than that for the control. Thus, it was considered a control mechanism of bacterial stable standing stock that the bacteria
shifted their organic substrate from extracellular dissolved organic carbon freshly released from phytoplankton to that already
stocked in the water column, though it is not known whether the dominant bacteria were the same. 相似文献
27.
Summary We have isolated Saccharomyces cerevisiae mutants, smp, showing stable maintenance of plasmid pSRI, a Zygosaccharomyces rouxii plasmid. The smp mutants were recessive and were classified into at least three different complementation groups. The three mutants also showed increased stability of YRp plasmids and the mutations are additive for plasmid stability. One mutation, smp1, confers a respiration-deficient (rho
0) phenotype and several Rho– mutants independently isolated by ethidium bromide treatment of the same yeast strain also showed increased stabilities of pSR1 and YRp plasmids. The wild-type S. cerevisiae cells showed a strongly biased distribution of pSR1 molecules as well as YRp plasmids to the mother cells at mitosis, while the smpf mutant did not show this bias. Another mutation, smp3, at a locus linked to ade2 on chromosome XV, confers temperature-sensitive growth. The SMP3 gene encodes a 59.9 kDa hydrophobic protein and disruption of the gene is lethal. 相似文献
28.
Hiroyuki Uno Yumiko Ohno Tsuneo Yamada Kensaku Miyamoto 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1991,169(2):231-239
Summary The responses of neurons in field L in the auditory neostriatum of the mynah bird, Gracula religiosa, were recorded during presentation of intact or manipulated mimic voices. A typical mimic voice konnichiwa elicited responses in most of the neurons. Neurons in the input layer (L2) of field L showed many peaks on peristimulus time histograms while those in other layers (L1 and L3) exhibited only one or two peaks. Several neurons in L1 and L3 responded only to the affricative consonant /t/ in the intact mimic voices. They did not respond to the affricative consonant in the isolated segment or to the one in the playbacked voice in reverse. Forty-five percent of the neurons (33/ 73) decreased in firing rates at the affricative consonant in the isolated segment compared with in the intact voice. Some of these neurons, in which neither the affricative consonant in the isolated segment nor bursts of noise alone elicited responses, exhibited clear phasic responses to /t/ in the case when bursts of noise with particular central frequencies preceded the affricative consonant. The responsiveness of these neurons appears to receive temporal facilitation. These results suggest that these neurons code the temporal relationship of speech sound.Abbreviations
HVc
hyperstriatum ventrale, pars caudale
-
TFN
temporally facilitated neuron
-
TSN
temporally suppressed neuron 相似文献
29.
Temperature effect of the photocyle of sensory rhodopsin (sR) was studied by nanosecond spectroscopy. Though the formation yield of sRM (sR370) was sharply decreased with temperature, those of sRK (sR680) and sRL were insensitive to temperature changes. These results show the existence of the branching process back to sR from sRL. The absorption maxima for sRK and sRL were 595 ± 5 and 555 ± 15 nm, respectively. 相似文献
30.
The interactions of T-cell receptor with self-Ia antigen on non-T cells induced IL-2 production and IL-2 receptors on the cell surface and thus responsiveness to IL-2 of T cells in autologous mixed-lymphocyte reaction (AMLR). Four-day-cultured autologous non-T cells lost their ability to stimulate T cells to produce and respond to IL-2 with concurrent decrease of HLA-DR and HLA-DQ antigen expressed on the cell surface. Culturing of non-T cells with 500 U/ml of recombinant interferon gamma (IFN-gamma) maintained their stimulating ability which was otherwise lost. Treatment of non-T cells with monoclonal anti-HLA-DR or anti-HLA-DQ antibody before mixture with T cells abrogated their ability to induce IL-2 production and IL-2 responsiveness of T cells. The combined data suggested that Ia antigen expressed on non-T cells is modulated by IFN-gamma, which increases the ability of non-T cells to stimulate autologous T cells to produce and respond to IL-2. 相似文献