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981.
982.
983.
C-Type Virus Released from Cultured Human Rhabdomyosarcoma Cells 总被引:44,自引:0,他引:44
R. M. McALLISTER M. NICOLSON M. B. GARDNER R. W. RONGEY S. RASHEED P. S. SARMA R. J. HUEBNER M. HATANAKA S. OROSZLAN R. V. GILDEN A. KABIGTING L. VERNON 《Nature: New biology》1972,235(53):3-6
RD-114 virus, released from human rhabdomyosarcoma cells, has all the characteristics of a mammalian C-type virus. Immunological tests indicate that it differs from all known C-type viruses and is the most likely candidate for a human C-type virus yet described. 相似文献
984.
985.
C57BL/6 nude beige mice (B6 nubq; no T cell, no NK activity) were used as recipients for the adoptive transfer of thymocytes from B6 gld mice (generalized lymphoproliferative disease) which are a model of systemic lupus erythematous. The [gld----nubg] chimeras showed several similarities with gld control mice including the T cell disorders (lymphoproliferation and Con A-response deficiency of splenocytes) and B cell disorders (hyperglobulinemia and elevated anti-single-stranded DNA antibody titers). This suggests that the gld lymphoproliferative disorder has a thymic origin (and does not result from an abnormally extrathymic T cell development) and that the gld T cells have an essential role for the emergence of the disorders of both the T and B cells. 相似文献
986.
Populations of the Australian sleepy lizard, Tiliqua rugosa, near Mt. Mary, South Australia carry natural infestations of two tick species Aponomma hydrosauri and Amblyomma limbatum. In field experiments at two sites, 18 km apart, lizards with experimentally increased tick loads had smaller home ranges,
moved shorter distances in a day, and were found basking more but moving less often than lizards from which ticks were experimentally
removed. The results were consistent for adult lizards in two years, and for sub-adults in a third year. Laboratory trials
showed that juvenile lizards that had tick infestations had lower sprint speeds than uninfested siblings, and that adults
with tick infestations had less endurance than those that were uninfested. The results contrast with those of a previous survey
that showed that lizards with high tick loads had greater body size and remained longer at a site, but indicate that there
may be a balance, for lizards, between the fitness advantages in occupying habitats with high-quality resources, and the costs
from parasites that also prefer those habitats.
Received: 02 March 1999 / Accepted: 07 October 1999 相似文献
987.
G. F. Katekak 《Biologia Plantarum》1985,27(2-3):92-99
The chemical and stereochemical properties of phytotropins are described in terms of a receptor model, based on their ability
to bind to a receptor isolated from maize coleoptiles. Their root gravitropic properties are correlated with their ability
to bind to the receptor. It is suggested that their ability to inhibit auxin transport, without more, may not be enough to
explain their physiological effects. 相似文献
988.
Prostaglandin (PG) stimulates female spawning behavior in goldfish and in some other teleosts in which female reproductive behaviors consist of postovulatory oviposition acts. This study examined the effects of PG on female sexual behavior in a teleost fish, Cichlasoma bimaculatum, in which female reproductive behaviors involve both preovulatory courtship and substrate cleaning behaviors, and post-ovulatory oviposition behavior. In females of established pairs, PGF2 alpha injection (5 micrograms, im) at any stage of the spawning cycle, or in the parental phase, rapidly induced substrate cleaning which soon merged into oviposition behavior (without egg release). These results support a role for PG in oviposition behavior of Cichlasoma. However, indomethacin (1 mg, ip), a PG synthesis inhibitor, did not block oviposition in ovulated females which had begun to spawn. Indomethacin may not have lowered PG levels sufficiently. Alternatively, as shown by J.J. Polder (1971, Neth. J. Zool. 21, 265), oviposition behavior may be induced or maintained by other factors associated with the spawning situation. 相似文献
989.
990.