Gene/Protein
Disease
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Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
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Target Concepts:
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Query: UMLS:C0020672 (
hypothermia
)
17,327
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
To examine the role of the early changes occurring in the liver within the first hours after a partial hepatectomy and in an attempt to demonstrate the involvement of subsequent regulatory mechanisms, the size of the remnant liver was modified at various times and by different surgical techniques. Male Wistar rats were submitted to a two-thirds "temporary partial hepatectomy" produced by a 3-h occlusion of the pedicle of the anterior lobes protected by local
hypothermia
. Various indexes of cell proliferation ([3H]thymidine uptake and 5-bromo-2'-deoxyuridine and proliferating cell nuclear antigen labeling) were not increased despite a
c-myc
expression as high as that observed after a two-thirds partial hepatectomy. The temporary partial hepatectomy and a sham operation induced modifications of the hepatocytes, allowing rapid DNA synthesis after a subsequent two-thirds partial hepatectomy. After this initial nonspecific response, the extent of the regenerative response is determined according to the size of the liver mass present approximately from the 10th to the 18th hour after the initial stimulus. For instance, when a one-third partial hepatectomy was converted into a two-thirds partial hepatectomy at the 10th hour, the DNA synthesis at the 24th hour reached the value observed after a straightforward two-thirds partial hepatectomy. Inversely, the regenerative response was significantly reduced when additional liver lobes were connected to neck vessels between the 14th and the 18th hour after a two-thirds partial hepatectomy. In conclusion, the actual liver mass present during the period corresponding to mid- to late G1 appears to control the magnitude of the proliferative response, which is not the simple consequence of the early changes following a partial hepatectomy.
...
PMID:Control of rate and extent of the proliferative response after partial hepatectomy. 935 34
The order Caprimulgiformes comprises five bird families adapted to nocturnal activity. The order has been regarded as monophyletic, but recent evidence suggests that swifts and hummingbirds (Apodiformes) belong within it. To explore the group's phylogeny, we obtained more than 2000 bp of DNA sequence from the cytochrome b and
c-myc
genes for 35 taxa, representing all major lineages and outgroups. Non-coding sequences of the
c-myc
gene were unsaturated, readily alignable and contained numerous informative insertions and deletions (indels), signalling broad utility for higher level phylogenetics. A 12 bp insertion in
c-myc
links Apodiformes with owlet-nightjars, confirming paraphyly of the traditional Caprimulgiformes. However, even this rare genomic change is homoplasious when all birds are considered. Monophyly of each of the five traditional families was strongly confirmed, but relationships among families were poorly resolved. The tree structure argues against family status for Eurostopodus and Batrachostomus, which should be retained in Caprimulgidae and Podargidae, respectively. The genus Caprimulgus and both subfamilies of Caprimulgidae appear to be polyphyletic. The phylogeny elucidates the evolution of adaptive traits such as nocturnality and
hypothermia
, but whether nocturnality evolved once or multiple times is an open question.
...
PMID:A molecular phylogenetic survey of caprimulgiform nightbirds illustrates the utility of non-coding sequences. 2003 91