Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.1.6 (CAD)
 4,420 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Extrachromosomal elements are common early intermediates of gene amplification in vivo and in cell culture. The time at which several extrachromosomal elements replicate was compared with that of the corresponding amplified or unamplified chromosomal sequences. The replication timing analysis employed a retroactive synchrony method in which fluorescence-activated cell sorting was used to obtain cells at different stages of the cell cycle. Extrachromosomally amplified Syrian hamster CAD genes (CAD is an acronym for the single gene which encodes the trifunctional protein which catalyzes the first three steps of uridine biosynthesis) replicated in a narrow window of early S-phase which was approximately the same as that of chromosomally amplified CAD genes. Similarly, extrachromosomally amplified mouse adenosine deaminase genes replicated at a discrete time in early S-phase which approximated the replication time of the unamplified adenosine deaminase gene. In contrast, the multicopy extrachromosomal Epstein-Barr virus genome replicated within a narrow window in late S-phase in latently infected human Rajii cells. The data indicate that localization within a chromosome is not required for the maintenance of replication timing control.
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PMID:Replication timing control can be maintained in extrachromosomally amplified genes. 167 57

Despite methodological differences in the limited number of studies reviewed, it appears that cardiovascular responses at rest and during exercise in the cold differ between patients with CAD and healthy subjects (Figures 1 and 2). This difference remains, even when attempting to control for investigation time and conditions. Typical exercise time reported for patients with CAD exercising in the cold is 4 to 8 minutes, where HR and SBP are generally the same or higher. Data corresponding to a similar time frame (5-15 minutes) in healthy subjects show HR to be lower or no different, whereas SBP was similar in both studies. Logically, healthy subject's RPP values would be similar or lower in the cold, which may be a teleological development to conserve myocardial oxygen uptake in the face of elevated sympathetic stimulation during cold exposure. The lower HR would offset the cold-induced hypertension and also help to preserve cardiac output. In healthy subjects, cardiac output is similar in the cold despite a higher stroke volume (SV) due to the lower HR. However, the similar cardiac output reported by Epstein and colleagues in patients with CAD, both at rest and during exercise at 15 degrees C, was obtained by increases in SV and HR. A blunted peripheral vasoconstriction response in older subjects could lead to reduced central blood volume with a corresponding decrease in venous return and SV. An inability to maintain an appropriate SV in the cold by patients with CAD may be responsible for the elevated HR to maintain cardiac output. However, in healthy subjects, SV appears to have a triphasic response.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A review of heart rate and blood pressure responses in the cold in healthy subjects and coronary artery disease patients. 852 83