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31.
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
32.
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
33.
Assembly and polarized release of Punta Toro virus and effects of brefeldin A. 总被引:11,自引:10,他引:1 下载免费PDF全文
Punta Toro virus (PTV), a member of the sandfly fever group of bunyaviruses, is assembled by budding at intracellular membranes of the Golgi complex. We have examined PTV glycoprotein transport, assembly, and release and the effects of brefeldin A (BFA) on these processes. Both the G1 and G2 proteins were transported out of the endoplasmic reticulum (ER) and retained in the Golgi complex in a stable structure, either during PTV infection or when expressed from a vaccinia virus recombinant. BFA treatment causes a rapid and dramatic change in the distribution of the G1 and G2 proteins, from a Golgi pattern to an ER pattern. The G1 and G2 proteins were found to be modified by medial but not trans Golgi network enzymes, in the presence or absence of BFA. We found that BFA blocks PTV release from cells but does not interfere with the intracellular assembly of infectious virions. Further, the BFA block of virus release is fully reversible, with high levels of virus release occurring upon removal of the inhibitor. It was also found that the release of PTV virions is polarized, occurring exclusively from the basolateral surfaces of the polarized Vero C1008 epithelial cell line. 相似文献
34.
The P gene of human parainfluenza virus type 1 encodes P and C proteins but not a cysteine-rich V protein. 总被引:17,自引:11,他引:6 下载免费PDF全文
Y Matsuoka J Curran T Pelet D Kolakofsky R Ray R W Compans 《Journal of virology》1991,65(6):3406-3410
The nucleotide sequence of the P gene of human parainfluenza virus type 1 (PIV1) was determined from cloned cDNA copies of the mRNA. By analogy with the gene organization of Sendai virus, two open reading frames in the mRNA sense of the gene were identified as coding sequences for the P protein (568 amino acids with an estimated molecular weight of 64,655) and the C protein (204 amino acids with an estimated molecular weight of 24,108). Comparison of the deduced amino acid sequences of the P and C proteins of PIV1 with those of Sendai virus showed a high degree of homology. However, a sequence for the cysteine-rich V protein, which was considered a common feature of other paramyxoviruses, was interrupted by the presence of multiple stop codons. The sequence analysis of three P-gene-specific cDNA clones generated from genomic RNA by polymerase chain reaction and one additional clone generated from mRNA confirmed that the coding sequence for the cysteine-rich region is silent in the PIV1 gene and thus is not translated into protein. Two potential editing sites with the consensus sequence 3'UUYUCCC were found in the PIV1 P gene at positions 564 to 570 and 1430 to 1436. However, examination of the PIV1 mRNA population by a primer extension method indicated that neither of these sites is utilized. These results indicate that the PIV1 P gene has a coding strategy different from those of other paramyxovirus P genes. 相似文献
35.
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
36.
Clastogenicity of 1-nitropyrene, dinitropyrenes, fluorene and mononitrofluorenes in cultured Chinese hamster cells 总被引:3,自引:0,他引:3
The chromosomal aberration test using a Chinese hamster lung cell line (CHL) was carried out on 1-nitropyrene (NP), 3 dinitropyrenes (DNPs), fluorene and 4 mononitrofluorenes with and without metabolic activation (rat S9 mix). The 3 DNPs (1,3-, 1,6- and 1,8-DNP) induced chromosomal aberrations in the absence of S9 mix. The frequencies of cells with aberrations after treatment for 48 h were 43% at 2 micrograms/ml of 1,3-DNP, 55% at 0.1 microgram/ml of 1,6-DNP and 45% at 0.025 microgram/ml of 1,8-DNP, indicating the order of clastogenic potency as 1,8- greater than 1,6- greater than 1,3-DNP. On the other hand, 1-NP, which is known to be a direct-acting mutagen in bacteria, was negative in the chromosomal aberration test without S9 mix, but clearly positive with S9 mix. This effect was dependent on the concentration of the S9 fraction in the reaction mixture. High-pressure liquid chromatography analysis showed that 1-NP was converted by S9 mix to several metabolites, including 1-aminopyrene (AP). The clastogenic activity of 1-AP, however, was equivocal without S9 mix, suggesting that active clastogens other than 1-AP exist. Fluorene induced chromosomal aberrations only in the presence of S9 mix (61.8% at 25 micrograms/ml). 1-, 2-, 3- and 4-nitrofluorene (NF) were more clastogenic in the presence of S9 mix than in the absence of S9 mix, suggesting that NFs were converted to more active clastogens by S9 mix. 相似文献
37.
K Tateishi Y Miura T Madarame T Yoshida K Suzuki N Takeichi H Kobayashi Y Matsuoka S Sato 《Regulatory peptides》1991,35(2):95-101
Levels of cholecystokinin (CCK) immunoreactivity and distribution of CCK immunoreactive cells were studied in the cerebral cortex of LEC (Long Evans Cinnamon) rats with hepatic encephalopathy. CCK immunoreactivity in water extract of cerebral cortex of LEC rats with hepatic encephalopathy (n = 7) was 41.5 +/- 2.6 (mean +/- S.E.M. pmol/g wet wt.) and that of LEC rats without encephalopathy (n = 8) was 67.1 +/- 6.9, the difference being significant (P less than 0.01). CCK immunoreactive cells assessed by immunohistochemistry were also markedly decreased in the cortex of LEC rats with hepatic encephalopathy of stage IV. Thus, CCK reduction was observed in the cerebral cortex of LEC rats with hepatic encephalopathy which are provided as a model for analysis of the pathogenesis of acute hepatic encephalopathy. 相似文献
38.
39.
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
40.
Endothelin: a new inhibitor of renin release 总被引:10,自引:0,他引:10
M Takagi H Matsuoka K Atarashi S Yagi 《Biochemical and biophysical research communications》1988,157(3):1164-1168
Endothelin is a recently-discovered vasoconstrictor peptide which is produced by endothelium and acts on vascular smooth muscle cells. At present its actions on other organs or cells are unknown. We studied the effect of endothelin on renin release in a dynamic superfusion system of dispersed rat juxtaglomerular (JG) cells. Endothelin in concentrations of 10(-11) M or more inhibited renin release dose-dependently and this inhibitory action vanished in the absence of extracellular Ca. It is suggested that endothelin is an inhibitory regulator of renin secretion from JG cells and its action is Ca-dependent. 相似文献