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1.
2.
Investigations were made of the growth ofNelumbo nucifera, an aquatic higher plant, in a natural stand in Lake Kasumigaura. A rise of 1.0 m in the water level after a typhoon in August
1986 caused a subsequent decrease in biomass ofN. nucifera from the maximum of 291 g d.w. m−2 in July to a minimum of 75 g d.w. m−2. The biomass recovered thereafter in shallower regions. The underground biomass in October tended to increase toward the
shore. The total leaf area index (LAI) is the sum of LAI of floating leaves and emergent leaves. The maximum total LAI was
1.3 and 2.8 m2 m−2 in 1986 and 1987, respectively. LAI of floating leaves did not exceed 1 m2 m−2. The elongation rates of the petiole of floating and emergent leaves just after unrolling were 2.6 and 3.4 cm day−1, respectively. The sudden rise in water level (25 cm day−1) after the typhoon in August 1986 caused drowning and subsequent decomposition of the mature leaves. Only the young leaves
were able to elongate, allowing their laminae to reach the water surface. The fluctuation in water level, characterized by
the amplitude and duration of flooding and the time of flooding in the life cycle, is an important factor determining the
growth and survival ofN. nucifera in Lake Kasumigaura. 相似文献
3.
Yoshinori Nio MD Takahiro Shiraishi Michihiko Tsubono Hideki Morimoto Chen-Chiu Tseng Kazuya Kawabata Yoshikazu Masai Manabu Fukumoto Takayoshi Tobe 《Biotherapy》1992,4(2):81-86
The present study was designed to evaluate the effects of a recombinant human G-CSF (rhG-CSF) and a mutein G-CSF(KW-2228) on leucopenia and tumor growth in mice treated with 5-fluorouracil (5-FU). In normal mice, the number of leucocytes (white blood cell, WBC) reached the peak 12 hours after a single injection of either type of G-CSF and decreased to the normal level after 24 hours. Daily administration induced a continuous increase in the WBC count, however, administrations at intervals did not. Meth-A fibrosarcoma was subcutaneously inoculated into the backs of syngeneic BALB/c mice. The mice were treated with 5-FU alone or with G-CSFs. Chemotherapy with 5-FU alone resulted in leucopenia and an insignificant inhibition of tumor growth. The conjunctive administration of G-CSFs with 5-FU resulted in a significantly augmented inhibition of tumor growth, and leukopenia was not seen. This augmenting effect was more prominent with KW-2228.These results suggest that in 5-FU chemotherapy G-CSFs may be beneficial in restoring the number of leucocytes from leucopenic state and in augmenting the tumor inhibitory effect. Furthermore, KW-2228 may be more beneficial than the natural type rhG-CSF. 相似文献
4.
A comparative study on immunosuppressive effects of cyclosporin A and FK 506 on peripheral blood lymphocytes in dogs 总被引:1,自引:0,他引:1
Kyoichi Takaori Yoshinori Nio Kazutomo Inoue Thein Tun Manaba Fukumoto Tohru Hashida Masato Yasuhara Ryohei Hori Takayoshi Tobe 《Biotherapy》1992,4(2):129-137
Immunosuppressive effects of cyclosporin A (CsA) and FK 506 (FK) on peripheral blood lymphocytes were studied in dogs in respect to mixed lymphocyte reaction, proliferative responses to recombinant interleukin-2 (rIL-2), phytohemagglutinin (PHA) and concanavalin-A (Con-A); phenotypes of OKIa1, CD3, CD8 and surface IgM; cytotoxic activity against xenogeneic tumor cells. CsA (2.0 or 5.0 mg/kg, intravenously) or FK (0.16 mg/kg, intramuscularly) was given to mongrel dogs every morning for serial 21 days. The blood concentrations of CsA, measured as trough levels by fluorescence polarization method, ranged from 37 to 350 ng/ml in dogs administered at 2.0 mg/kg and from 170 to 894 ng/ml in dogs administered at 5.0 mg/kg during treatment, respectively. In dogs treated with FK at a dose of 0.16 mg/kg, the drug concentrations in the plasma during treatment ranged from 0.16 to 1.8 ng/ml. Mixed lymphocyte reaction and proliferative responses to rIL-2, PHA and Con-A, which were declined by CsA, were not affected by FK. In contrast, the proportion of OKIa1+ cells was not affected by CsA, whereas FK decreased the proportion of OKIa1+ cells progressively during the course of treatment. Cytotoxic activity was suppressed by both CsA and FK. These results possibly indicate that CsA and FK exert their immunosuppressive effects via different mechanisms. 相似文献
5.
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
6.
Hemodynamic effects of atrial natriuretic hormone 总被引:1,自引:0,他引:1
B L Pegram N C Trippodo T Natsume M B Kardon E D Frohlich F E Cole A A MacPhee 《Federation proceedings》1986,45(9):2382-2386
The atrial natriuretic hormone (ANH) alters cardiovascular function independent of changes in body fluid volume. Most investigators agree that ANH decreases mean arterial pressure (MAP). However, although some investigators have observed a decrease in total peripheral resistance in association with the decrease in MAP, a more frequent observation has been decreased cardiac output (CO). The mechanism whereby ANH decreases CO is unknown, but does not appear to be the result of direct myocardial depression, reductions in intravascular or cardiopulmonary volumes, or venodilation. Alterations in skeletal muscle and splanchnic blood flow have been reported by some but not all investigators. Although increases in renal blood flow have been reported, they are transitory and have not been consistently observed by all researchers. The cardiovascular effects of ANH appear to be influenced not only by the dose, but also by the cardiovascular control mechanisms that operate at the time of ANH administration. Non-renin-dependent hypertensive models exhibit a decrease in MAP associated with decreased CO, whereas in renin-dependent animals this hypotension is associated with a decrease in total peripheral resistance. 相似文献
7.
Norimichi Kan Takashi Okino Masaki Nakanishi Kohei Satoh Kazuhisa Ohgaki Takayoshi Tobe 《Cancer immunology, immunotherapy : CII》1989,28(4):260-266
Summary The synergistic antitumor effect of interleukin-2(IL-2)-cultured tumor-bearer spleen cells (cultured lymphocytes) and immune fresh spleen cells was examined. Tumor-bearer cultured lymphocytes were obtained by culturing BALB/c spleen cells from syngeneic MOPC104E-tumor-bearing mice for 11 days with crude IL-2 and a soluble tumor extract. These cultured lymphocytes had weak antitumor activity when transferred i.p. into tumor-bearing mice that had been inoculated i.p. with 105 tumor cells 5 days previously. Immune fresh spleen cells, obtained from mice in complete remission after the treatment with cyclophosphamide, also had weak antitumor activity when transferred at the same schedule. The cultured cells and the fresh cells, mixed together before transfer, significantly augmented the therapeutic effect. At least 1×107 tumor-bearer cultured lymphocytes and 4×107 immune cells were needed for the synergistic effect. A tumor-specific combination was needed for both cultured and fresh cells. The effective subpopulation of tumor-bearer cultured lymphocytes was a cytotoxic one from an Lyt2+ precursor, and that of the immune fresh spleen cells was noncytotoxic, Lytl+ and Lyt2+ T-cells.A similar synergistic effect was also observed during in vitro coculture of tumor-bearer and immune cells. Cytotoxicity, as assessed by the 51Cr-release test, of tumor-bearer IL-2-cultured lymphocytes was maintained most effectively after 3 or 4 days of culture without IL-2 when the lymphocytes were cocultured with immune fresh spleen cells and tumor cells. 相似文献
8.
When two separated Chara internodal cells were kept in contactover a length of 14 mm or more in moist air, an action potentialof one cell could be transmitted to the other cell in about40% of cases (ephaptic transmission). The action potential ofthe former cell was sometimes eliminated transiently when anew action potential was elicited in the latter cell. The newaction potential reactivated the former cell. The conductionvelocity of the action potential was reduced from 0.30?0.11cm/s (mean?SD) to 0.15?0.05 cm/s by ephaptic transmission ofthe action potential. Substitution of an artificial pond waterfor moist air or contact over a shorter length (4 mm insteadof 14 mm or more) between the two cells reduced the couplingratio, the ratio of the change in membrane potential of onecell to that of the other cell, and no transmission was observed.After ephaptic transmission, the action potentials of the twocells were conducted at almost the same velocity along the cells.The velocity was increased to 0.68?0.06 cm/s by simultaneousconduction of the action potentials in the two adjacent cells.When the simultaneously conducted action potentials reachedthe node of one cell, at the point at which another cell madecontact, they were able very frequently to trigger a new actionpotential in the adjoining cell. (Received September 28, 1989; Accepted April 5, 1990) 相似文献
9.
Nodal cells of Chara braunii were exposed to artificial pondwater (APW) for a month or more, with removal of larger surroundingcells. The membrane resistance, resting potential, amplitudeof the action potential, and threshold voltage measured fromthe resting level were examined. Exposure to APW had markedeffects on membrane properties. (Received April 2, 0990; Accepted August 24, 1990) 相似文献
10.
Takayoshi Yoshida Hiroshi Watari 《European journal of applied physiology and occupational physiology》1994,69(6):465-473
To investigate the splitting of the inorganic phosphate (Pi) peak during exercise and recovery, a time-resolved 31phosphorus nuclear magnetic resonance spectroscopy (31P-MRS) technique was used. Seven healthy young sedentary male subjects performed knee flexion exercise in the prone position inside a 2.1-T magnet, with the surface coil for 31P-MRS being placed on the biceps femoris muscle. After a 1-min warm-up without loading, the exercise intensity was increased by 0.41 W at 15-s intervals until exhaustion, followed by a 5-min recovery period. The 31P-MRS were recorded every 5 s during the rest-exercise-recovery sequence. Computer-aided contour analysis and pixel imaging of the Pi and phosphocreatine peaks were performed. Five of the seven subjects showed two distinct Pi peaks during exercise, suggesting two different pH distributions in exercising muscle (high pH and low pH region). In these five subjects, the high-pH increased rapidly just after the onset of exercise, while the low-pH peak increased gradually approximately 60 s after the onset of exercise. During recovery, the disappearance of the high-pH peak was more rapid than that of the low-pH peak. These findings suggest that our method 31P-MRS provides a simple approach for studying the kinetics of the Pi peak and intramuscular pH during exercise and recovery. 相似文献