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  • Articles  (4)
  • Bone Gla protein  (2)
  • seed dispersal  (2)
  • Springer  (4)
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  • Frontiers Media
  • National Academy of Sciences
  • Biology  (4)
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  • Articles  (4)
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  • Springer  (4)
  • Annual Reviews
  • Frontiers Media
  • National Academy of Sciences
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  • 1
    ISSN: 1432-0827
    Keywords: 22-oxa-1α, 25 Dihydroxyvitamin D3 ; 1,25(OH)2D3 ; Bone histomorphometry ; Bone Gla protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Thein vivo effects of 22-oxa-1α, 25 dihydroxyvitamin D3 (OCT), on bone mineral metabolism were investigated in normal male Sprague-Dawley rats. The rats were administered either vehicle (control), low-dose OCT (25 ng/100 g body weight), or high-dose OCT (250 ng/100 g body wt). High-dose OCT increased serum ionized calcium (P〈0.05) and decreased serum parathyroid hormone (PTH) (P〈0.05) at all time points and increased serum bone Gla protein on days 7 and 28 (P〈0.05) compared with controls. Lowdose OCT decreased serum PTH at all the time points (P〈0.05) compared with controls. Tibial bone histomorphometry showed no significant differences between the two doses of OCT and controls. We found that OCT has minimal direct effects on bone metabolism in normal male rats in contrast to 1,25 dihydroxyvitamin D3. This property may be advantageous in the treatment with OCT of cell-proliferative diseases.
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  • 2
    ISSN: 1432-0827
    Keywords: Rapamycin ; Bone mineral metabolism ; Bone Gla protein ; Immunosuppressants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Immunosuppressants have adverse effects on bone mineral metabolism in animal and human studies, with corticosteroids producing low-turnover osteopenia, and cyclosporin-A (CsA) producing high-turnover osteopenia. Rapamycin (RAPA) is a new immunosuppressant reported to be at least 10 times more potent than CsA, and acts via a different pathway to CsA and the other new immunosuppressant FK506. This study investigated the effects of RAPA on bone mineral metabolism in the rat. Forty-two, 10-week-old, male Sprague Dawley rats were divided into three groups, and treated according to the following protocol: group A (control) received RAPA vehicle by daily gavage for 14 days (n = 12); group B (high dose RAPA) received RAPA 2.5 mg/kg/day by daily gavage for 14 days (n = 15); group C (low dose RAPA) received RAPA 1.25 mg/kg/day by daily gavage for 14 days (n = 15). Rats were weighed and bled on days 0, 7, and 14 for measurement of blood ionized calcium, bone Gla protein (BGP), parathyroid hormone (PTH), and 1,25(OH)2D. Tibial bone histomorphometry was determined on day 14 after double-calcein labeling. Weight gain was similar in the two groups treated with RAPA compared with control animals. High-dose RAPA (group B) transiently depressed serum BGP levels on day 7, with elevated blood ionized calcium levels on day 7, and lowered 1,25(OH)2D levels on day 14. Serum PTH levels were unchanged. Low dose RAPA (group C) did not affect calciotropic hormones. Histomorphometric analyses of tibial metaphyses revealed that parameters of bone formation and resorption were not significantly different in the groups treated with RAPA (group B and C) compared with control animals (group A). Trabecular bone volume (BV/TV) in group B (high-dose RAPA) (15.39 ± 1.01%) and C (low-dose RAPA) (15.38 ±0.57%) was not significantly altered compared with group A (control) (16.42 ± 0.86%). Short-term treatment with RAPA, unlike CsA, does not result in excess resorption and loss of bone volume. The depressed serum 1,25(OH)2D levels seen with high-dose RAPA therapy may adversely effect bone mineral metabolism in the long term.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 16 (1990), S. 2993-3013 
    ISSN: 1573-1561
    Keywords: Ant ; ant-garden ; benzothiazole ; Camponotus ; Hymenoptera ; Formicidae ; chemical mimicry ; epiphyte ; 2-hydroxy-3-methoxybenzene-methanol ; 1-(2-hydroxy-4-methoxyphenyl)ethanone ; 2-hydroxy-6-methyl-benzoic acid ; methyl ester ; 1-(2-hydroxy-6-methylphenyl)ethanone ; 1-(2,4-dihydroxyphenyl)ethanone ; limonene ; 6-methyl-methylsalicylate ; 6-MMS ; seed dispersal ; symbiosis ; tropical forests ; vanillin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A number of volatile compounds occur on the seeds of taxonomically unrelated ant-garden epiphytes in western Amazonia. In field trials in southeastern Peru, we assayed the responses of ant-garden ants (Camponotus femoratus) to these and structurally similar compounds applied to artificial “seeds” made from zeolite molecular sieves. Benzothiazole,2, present on seeds of eight ant-garden epiphytes, repelled ants over the range of concentrations tested, as did 1-(2-hydroxy-6-methylphenyl)ethanone,3, occurring on seeds of six ant-garden epiphytes. 2-Hydroxy-6-methylbenzoic acid, methyl ester (methyl-6-methylsalicylate, 6-MMS),1, found on seeds of at least nine ant-garden epiphytes, was mildly repellent at high concentration, but stimulated excitement, seed handling, and (rarely) seed carrying at lower concentrations. Vanillin,5, a seed compound of four ant-garden epiphytes, and limonene,6, a monoterpene from seeds of three ant-garden epiphytes, both stimulated excitement, alarm, seed handling, and (rarely) seed carrying. Identified from seeds of seven ant-garden epiphytes, 1-(2,4-dihydroxyphenyl)ethanone,4, elicited little or no response. Among 70 compounds tested (mainly aromatic compounds), those found on seeds of ant-garden epiphytes or having structural features in common with such compounds were the most attractive to the ants. Although not present on epiphyte seeds, 2-hydroxy-3-methoxybenzenemethanol,10, consistently stimulated seed transport to the nest in one year, but did so only rarely in subsequent years. Some of the volatile compounds on seeds of ant-garden epiphytes probably play a role in ant attraction to epiphyte seeds, but evidence remains ambiguous. Finally,Ca. femoratus responded to one test compound [1-(2-hydroxy-4-methoxyphenyl)ethanone,60] (absent from epiphyte seeds) by descending from the vegetation to the ground.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 16 (1990), S. 1791-1816 
    ISSN: 1573-1561
    Keywords: Ant ; ant garden ; Hymenoptera ; Formicidae ; Camponotus ; chemical mimicry ; citronellol ; convergent evolution ; epiphyte ; mellein ; methyl 6-methylsalicylate ; Perú ; seed dispersal ; symbiosis ; tropical forest
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In ant gardens of lowland Amazonia, parabiotic ant speciesCamponotus femoratus andCrematogaster cf.limata parabiotica cultivate a taxonomically diverse group of epiphytic plants, whose establishment is restricted to arboreal carton ant nests. Epiphyte seeds are collected by workers ofCa. femoratus, the larger of the two ants, and stored unharmed in brood chambers where they subsequently germinate. Although seeds of some ant-garden epiphytes bear nutritional rewards, previous studies have shown that these rewards are not sufficient to explain the pattern of ant attraction to seeds. Five aromatic compounds occur frequently in and on the seeds of most ant-garden epiphytes and may be chemical cues by which ants recognize propagules of their symbiotic plants. The most widely distributed of these is methyl 6-methylsalicylate [6-MMS]1, previously reported as a major mandibular gland product in relatedCamponotus species and present in trace quantities inCa. femoratus males. (−)-Citronellol6 (previously unreported inCamponotus) was the principal volatile constituent in extracts of male heads, and (−)-mellein7 was present in small quantities. Discovery of 6-MMS inside the mandibular glands of maleCa. femoratus (and its presence in analogous glands of related ants) offers preliminary support for Ule's (1906) hypothesis that seeds attract ants by mimicking ant brood. In addition, the likely fungistatic activity of seed compounds suggests that they could retard microbial pathogens of ants and plants in the organic detritus of nest gardens. While the presence of identical seed compounds in so many unrelated plant lineages might represent a remarkable case of convergent evolution, other interpretations are possible.
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