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1.
Presented a choice between conspecific males and 2 congeneric males, virgin females ofMelittobia australica andM. digitata chose conspecific males disproportionately more often, whereasM. femorata females distributed themselves evenly among the choices. Empty tubes, provided as the fourth choice in the test apparatus,
were entered much less often than tubes containing live males. Females of all species chose “wrong” males about equally frequently.
These observations suggest that even non-conspecific males possess some degree of attractiveness to virgin females. Chemicals
in the sex pheromone of the males are presumed to be the source of the males' attractancy. The incomplete species specificity
is interpreted in light of the life history of this genus, and it is suggested that specific recognition cues operate primarily
after the sexes come together.
Supported by a grant from Kagoshima Prefecture in Japan under the exchange program of faculty members between Kagoshima University
and the University of Georgia. 相似文献
2.
K Miyazaki F Umenishi K Funahashi N Koshikawa H Yasumitsu M Umeda 《Biochemical and biophysical research communications》1992,185(3):852-859
Progelatinase A was purified as a complex with TIMP-2 from the conditioned medium of a human glioblastoma cell line. The TIMP-2/progelatinase complex was resistant to the activation by p-aminophenylmercuric acetic acid (APMA), and showed less than 10% of the activity of the TIMP-2-free active enzyme. When the complex was incubated with stromelysin in the presence of APMA, the 64-kDa progelatinase was effectively converted to the 57-kDa mature enzyme, increasing its gelatinolytic activity about 8-fold. These results suggest that stromelysin is a natural activator of TIMP-2-bound progelatinase A. 相似文献
3.
Junichi Ishihara Nagahiro Saijo Yasutsuna Sasaki Hidehiko Nakano Akira Ozaki Hidenobu Takahashi Masanori Sakurai Kazuhiko Nakagawa Masaaki Iigo Fumihiko Kanzawa Akio Hoshi Weon Seon Hong James R. Jett Terumi Takahashi 《Cancer immunology, immunotherapy : CII》1987,24(3):185-189
Summary The antitumor effect of recombinant human tumor necrosis factor (rH-TNF) on two clones of rat fibrosarcoma with different metastatic potential to lymph nodes was examined. The colony formation of clone A, which has high metastatic potential, was completely inhibited by continuous exposure to rH-TNF at 50 U/ml. In contrast, colony formation of clone G, which has low metastatic potential, was not inhibited by high concentrations of rH-TNF (10,000 U/ml). The inhibitory effect of rH-TNF on colony formation by clone A was also observed with a 1-h exposure to rH-TNF. This effect was time and concentration dependent, as determined by the colony assay, 3H-thymidine uptake assay, and 51Cr-release assay. 3H-thymidine and 3H-uridine uptake per cell of clone A exposed to rH-TNF was not decreased. This suggests that the mechanisms of the antitumor effect of rH-TNF were not due to inhibition of DNA and RNA synthesis of tumor cells. In vivo growth and lymph node metastases of clone A inoculated i.p. to Donryu strain rats were completely suppressed by 14 consecutive i.p. injections of 105 or 106 U/kg per day of rH-TNF. On the other hand the growth of clone G was not influenced by rH-TNF administration. 相似文献
4.
Chuen-Shang C. Wu Junichi Hasegawa Andrew P. Smith Horace H. Loh Nancy M. Lee Jen Tsi Yang 《Journal of Protein Chemistry》1990,9(1):3-7
Based on circular dichroism (CD) and the sequence-predictive method, the opioid-binding cell adhesion molecule (OBCAM) consisted of one half -sheets and one fourth -helices. This is consistent with significant sequence homology of the protein to several members of the immunoglobulin (Ig) superfamily, particularly cell adhesion molecules, which are rich in -sheets. Hydropathy analysis suggests that hydrophobic and hydrophilic regions were evenly distributed along the sequence, but the NH2- and COOH-termini were hydrophobic. Hydrophobic moments and Fourier-transform amphipathic analyses further suggest that residues 23–30 and 83–93 were amphiphathie -sheets. The overall conformation of OBCAM was unaltered by adding linoleic acid, which is required for opioid ligand binding. 相似文献
5.
Increased expression in vivo and in vitro of foreign genes directed by A-type inclusion body hybrid promoters in recombinant vaccinia viruses.
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S Funahashi S Itamura H Iinuma K Nerome M Sugimoto H Shida 《Journal of virology》1991,65(10):5584-5588
We constructed A-type inclusion body (ATI) hybrid promoters, that is, late ATI promoters followed by tandemly repeated early regions of the promoter for the 7.5-kDa protein (the 7.5-kDa promoter). The repetition of the whole early promoter sequence of the 7.5-kDa gene, including the upstream consensus sequence and initiation region, efficiently increased the early expression of the bacterial chloramphenicol acetyltransferase gene in recombinant vaccinia virus. Recombinant vaccinia virus could express influenza virus hemagglutinin via the hybrid promoter more efficiently, induced higher levels of neutralizing antibody and cytotoxic T lymphocytes, and consequently protected mice more efficiently against challenge with influenza virus than did recombinant vaccinia virus containing the widely used 7.5-kDa promoter. 相似文献
6.
Promotive Effect of C18-Unsaturated Fatty Acids on the Abscission of Bean Petiole Explants 总被引:1,自引:0,他引:1
The abscission-promoting effects of C18-unsaturated fatty acidswere studied in bean (Phaseolus vulgaris L. cv. Masterpiece)petiole explants with the junction between the petiole and thepulvinus in the primary leaves in the light. Linolenic, linoleicand oleic acids promoted the abscission of the explants in thelight. Linolenic acid was the most effective among the compoundstested and its promotive effect was evident without any accompanyingincrease in the production of ethylene from the explants, ascompared with non-treated explants. Linolenic acid is easilyconverted to its hydroperoxide during the incubation with explants,as indicated by the formation of the conjugated diene and thegeneration of ethane. The production of ethylene from the explantstreated with linolenic acid was completely inhibited by theaddition of aminoethoxyvi-nylglycine (AVG), but large amountsof ethane were still generated. The promotive effect of linolenicacid was almost eliminated by the addition of scavengers offree radicals. Hydrogen peroxide and tert-butyl hydroperoxidepromoted abscission in the light. From these results, we concludedthat the abscission-promoting effect of linolenic acid are notmediated by the effect of ethylene but by the effect of itshydroperoxide, while the well-established pathway for the biosynthesisof ethylene from S-adenosylmethionine to ethylene, via 1-aminocyclopropane-l-carboxylicacid (ACC), was apparently operative. (Received May 1, 1991; Accepted July 10, 1991) 相似文献
7.
8.
Summary Spermatozoa from fertile and infertile human ejaculates were observed under the scanning electron microscope. A parallel study of sections was performed by transmission electron microscope.The normal head shows under the scanning electron microscope vesicular elevations in the region of the acrosome and a smooth and rigid appearance corresponding to the postnuclear cap whose occurrence is confirmed under the transmission electron microscope. Immediately anterior to this cap a shallow furrow transverses the head. Duplicated, unusually large or small and deformed heads are found under the scanning electron microscope. Most of these abnormal heads show no surface structure suggesting an acrosome.The neck and middle piece are occasionally, though frequently in abnormal spermatozoa, covered by a cytoplasmic droplet. Otherwise, the mitochondrial sheath is recognized under the scanning electron microscope as a beaded thickening in the middle piece. The lack of mitochondria is manifested by a smooth middle piece thinner than the principal portion. Transmission electron microscopy of sections reveals various types of anomalies in the number of cores, core filaments and mitochondria embedded in the cytoplasmic droplets.Abnormalities in the principal portion of the tail such as duplication, unusual thickness and length are shown under the scanning electron microscope.The investigation indicates that scanning electron microscopy is suited for the clinical as well as cytological examination of human ejaculate spermatozoa. 相似文献
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