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  • IAA  (3)
  • Osteoporosis  (2)
  • Springer  (5)
  • Public Library of Science (PLoS)
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  • Springer  (5)
  • Public Library of Science (PLoS)
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  • 1
    ISSN: 1432-0827
    Keywords: Diabetes mellitus ; Amylin ; Osteoporosis ; Bone mineral metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Amylin is normally secreted in a regulated fashion by the pancreatic β-cells in parallel with insulin and has been reported to have bone-conserving properties. Type I diabetes mellitus results in a low-turnover osteopenia in the presence of decreased amylin, which is in contrast to type II diabetes where less bone loss, in the presence of high amylin levels, occurs. We investigated the effects of amylin on bone mineral metabolism in normal and dibetic (streptozotocin-induced) rats, in order to ascertain whether amylin would modify the streptozotocin-induced diabetic osteopenia. Tenweek-old male Sprague-Dawley rats were randomized as follows: group A (n=18) received normal saline; group B (n=18) received amylin; group C, diabetic rats (n=23), received normal saline; and group D, diabetic rats (n=23), received amylin. Amylin (100 pmol/100 g b. w.) was administered by a daily subcutaneus injection. Double calceinlabeled tibiae were removed for histomorphometric analysis followed sacrifice on day 19. Results showed no difference in blood ionized calcium between groups. Blood glucose remained above 600 mg/dl in the diabetic animals and was not affected by the administration of amylin. Serum osteocalcin, insulin-like growth factor-1 (IGF-1), parathyroid hormone (PTH), and 1,25 dihydroxyvitamin D [1,25(OH)2D] were significantly lower in the diabetic rats compared with control group A by day 19. Amylin produced higher levels of serum osteocalcin in group B on day 9 (P〈0.05) compared with controls but returned to control values (group A) by day 19; no such change occurred in the diabetic group. Amylin administration did not influence IGF-1, 1,25(OH)2D or PTH levels compared with the untreated animals. Analysis of the bone histomorphometry showed a low-turnover osteopenia in the diabetic animals. Amylin administration resulted in a significant increase in bone volume in the normal rats, group B (P〈0.05), but was unable to significantly alter this parameter in the diabetic animals. In conclusion, amylin has a beneficial effect on the bone metabolism of the rat in vivo by increasing bone volume. It is, however, unable to overcome the osteopenia caused by streptozotocin-induced diabetes mellitus at the doses used in this study.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 55 (1994), S. 243-248 
    ISSN: 1432-0827
    Keywords: Osteoporosis ; Bone density ; Longitudinal studies ; Statistical models ; Decision models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract We calculated how long to wait before repeating bone mineral density (BMD) measurements to reassess fracture risk. Correlation results from serial measurements of 495 postmenopausal Japanese-American women were used to estimate 95% confidence intervals (CI) for future BMD. After 7 years of follow-up, BMD correlations with the initial measurement ranged between 0.81 and 0.94, depending on age group and measurement site. In this analysis, the period between measurements was defined as the time required for the lower 95% CI to fall below the BMD value corresponding to doubling of fracture risk. Progressive bone loss causes fracture risk to double after 10 years, on average. However, the 95% CIs indicate that a second BMD measurement will detect risk doubling after only 2 or 3 years for some women. For untreated, early postmenopausal women, the period between measurements was approximately 2–5 years for the radius and 4–6 years for the calcaneus, depending on the initial BMD level. The period was approximately 1 year longer for women age 60 and older. Treatments that halve the bone loss rate would increase the period by 1–3 years. In the absence of a second measurement of BMD, the CI will continue to expand with time, corresponding to a wider range in risk between individuals, and a greater proportion of women will be at increased fracture risk. Obtaining a second BMD measurement pinpoints the patient's status within the precision of the measurement. We conclude that repeated BMD measurements will provide a more accurate estimate of fracture risk than a single, baseline measurement.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Plant growth regulation 8 (1989), S. 215-223 
    ISSN: 1573-5087
    Keywords: IAA ; IBA ; conjugated IBA ; rooting ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Indole-3-butyric acid (IBA) was identified by thin layer chromatography, gas-liquid chromatography and gas chromatography-mass spectrometry in kernels and leaves of corn (Zea mays) var. Hazera 224. Free and ester conjugated IBA were present in dry and germinating corn kernels and leaves. This is the first report of IBA in a monocotyledonous plant and, as far as we know, the first evidence for the presence of conjugated IBA.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Plant growth regulation 11 (1992), S. 357-362 
    ISSN: 1573-5087
    Keywords: Citrus ; conjugation ; ethylene ; IAA ; IBA ; polar transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Transport and metabolism of radiolabeled indole-3-butyric acid (IBA) were studied in midrib sections of Cleopatra mandarin (Citrus reticulata Blanco) and compared to that of indole-3-acetic acid (IAA). Exogenous IBA was metabolized by the midribs to a polar compound, probably an ester conjugate. Ethylene pretreatment of the midribs reduced their capacity to metabolize IBA by ca. 70% as compared to air pretreatment. IBA transport capacity in the leaf midribs was ca. two times greater in the basipetal direction than the acropetal. The basipetal transport capacity of 3H-IBA was lower than that of 14C-IAA (ca. 24% and 39% of the uptake, respectively). While ethylene treatment reduced basipetal transport of IAA by ca. 70% it did not affect the transport of IBA. Most of the transported label was found as free IBA, but the reduction of IBA conjugation by ethylene treatment did not affect the transport capacity.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Plant growth regulation 17 (1995), S. 127-132 
    ISSN: 1573-5087
    Keywords: anaerobic methanogenic thermophilic digestion ; auxin ; biogas ; IAA ; IBA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A large amount of solid waste remains after the production of instant coffee. This waste has to be moved to dumps, where it poses a threat of environmental pollution. Treatment of this waste by anaerobic methanogenic thermophilic digestion produced, besides biogas, a digested slurry which was used as a growth medium for horticulture, and proved to be a suitable and economical substitute for peat moss. Biological tests with mung bean cuttings and Grevillea plantlets showed promotional effects on rooting of the slurry and its sieved fraction extract, washed with water (Capul). Green coffee beans, instant coffee waste, its anaerobically-digested slurry and Capul were extracted by various methods and the extracts were analyzed by TLC, HPLC and GC/MS. Examinations showed clearly the presence of IAA and IBA in free and bound forms in all the substrates. The values of free and bound IAA were calculated by use of an internal standard and GC/MS. The amount of conjugated IAA was found to be much higher than that of free IAA, in both the coffee beans and instant coffee waste (11.1 vs 2.7 nmol g−1, respectively). In the digested slurry and Capul, however, most of the IAA was present as the free form and was approximately 23.5–33.0 nmol g−1, which is almost ten times more than in the waste, and almost twice the total amount of IAA in coffee beans. It is postulated that the high levels of free IAA in the digested instant coffee waste are a result of catabolism of tryptophan by anaerobic bacteria.
    Type of Medium: Electronic Resource
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