| 1. |
- Szymanski, J. J., et al.
(author)
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MEGA : A search for the decay mu –> e gamma
- 1994
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In: Intersections between particle and nuclear physics. Proceedings, 5th Conference, St. Petersburg, USA, May 31-June 6, 1994. ; , s. 789-792
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Conference paper (peer-reviewed)
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| 2. |
- Fairhall, Keith M, 1951, et al.
(author)
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Effect of food withdrawal and insulin on growth hormone secretion in the guinea pig.
- 1990
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In: Endocrinology. - 0013-7227. ; 127:2, s. 716-23
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Journal article (peer-reviewed)abstract
- The guinea pig is unusual in that its postnatal growth appears to be independent of GH even though its pituitary gland produces a GH molecule. The effects of fasting on the GH secretory pattern and the GH responses to insulin, GH-releasing factor (GRF), and somatostatin (SS) during fasting have now been studied by automatic microsampling of blood in chronically cannulated normal guinea pigs. Withdrawal of food in both male and female guinea pigs changed the GH secretory pattern dramatically. The normal episodic GH secretory pattern [large GH peaks occurring at 3.6 +/- 0.4-h intervals over a low (approximately 0.5-1.5 ng/ml) baseline secretion] was altered to a pattern of more continuous GH output, characterized by a 10-fold elevated baseline secretion (5-15 ng/ml) with no large secretory episodes or troughs. Glucose injections (three injections of 600 mg, iv, at hourly intervals) in fasted guinea pigs lowered their elevated blood GH levels significantly (from 9.1 +/- 1.1 to 6.5 +/- 0.9 ng/ml). Insulin injections (1, 2, or 6 U, iv) inhibited spontaneous GH pulses in normally fed animals, but had little effect on the high continuous GH tone during fasting. The elevated GH secretion in fasted animals could be inhibited by continuous infusion of SS or a single iv injection of a long-acting SS analog. The secretion of GH during fasting could be further increased, either by injections of GRF (two injections of 2 micrograms, iv, 90 min apart), producing peak levels of 102 +/- 16 and 68 +/- 21 ng/ml (above a baseline output of 8.8 +/- 2.2 ng/ml), or by a continuous iv infusion of GRF (12 micrograms/h). Because the GH secretory pattern in the guinea pig is so sensitive to nutrition and insulin, this species may provide an interesting model in which to study selectively the metabolic, as opposed to growth-promoting, actions and regulation of GH.
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| 3. |
- Gabrielsson, Britt, 1957, et al.
(author)
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Growth hormone secretion in the guinea-pig
- 1990
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In: Journal of Endocrinology. - 1479-6805 .- 0022-0795. ; 124:3, s. 371-80
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Journal article (peer-reviewed)abstract
- The guinea-pig is unusual in that it continues to grow at a normal rate after hypophysectomy. Although its pituitary gland appears to contain a GH, this has not been isolated or characterized, and nothing is known about its secretion or physiological control. We have identified guinea-pig GH, established a sensitive heterologous radioimmunoassay and adapted our automatic blood microsampling method to study spontaneous GH secretion in this species. In male guinea-pigs, GH is released in an episodic pattern, reminiscent of the rat. Large multicomponent pulses of GH secretion occur every 3-4 h between periods of low or undetectable GH release, whereas most females showed a more uniform pulsatile pattern with pulses every 1-2 h. GH was released in response to GH-releasing factor (GRF) injections (2, 10 or 20 micrograms [Nle27]-GRF(1-29)NH2) in a dose-dependent fashion, and i.v. infusion of somatostatin (50 micrograms/h) blocked spontaneous GH pulses, eliciting a rebound release (from 2.0 +/- 0.8 (S.E.M.) to 36 +/- 17 micrograms/l 30 min after stopping the infusion). Infusions of a GH-releasing hexapeptide (100 or 400 micrograms/h for 4 h) also released GH. These results provide the first description of the pattern of GH release in the guinea-pig, and suggest that the striking episodic pattern is controlled by the same hypothalamic peptides that regulate GH in other species. Since the guinea-pig grows well in the absence of GH, this species may use GH for its metabolic, rather than growth-promoting actions. The guinea-pig may well prove a useful model, now that methods are available for studying its endogenous GH secretion.
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| 4. |
- Pennell, Roger I., et al.
(author)
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Developmental regulation of a plasma membrane arabinogalactan protein epitope in oilseed rape flowers
- 1991
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In: Plant Cell. - : Oxford University Press (OUP). - 1040-4651 .- 1532-298X. ; 3, s. 1317-1326
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Journal article (peer-reviewed)abstract
- We have identified and characterized the temporal and spatial regulation of a plasma membrane arabinogalactan protein epitope during development of the aerial parts of oilseed rape using the monoclonal antibody JIM8. The JIM8 epitope is expressed by the first cells of the embryo and by certain cells in the sexual organs of flowers. During embryogenesis, the JIM8 epitope ceases to be expressed by the embryo proper but is still found in the suspensor. During differentiation of the stamens and carpels, expression of the JIM8 epitope progresses from one cell type to another, ultimately specifying the endothecium and sperm cells, the nucellar epidermis, synergid cells, and the egg cell. This complex temporal sequence demonstrates rapid turnover of the JIM8 epitope. There is no direct evidence for any cell-inductive process in plant development. However, if cell-cell interactions exist in plants and participate in flower development, the JIM8 epitope may be a marker for one set of them.
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