Metabolic shifts

A reduction of HED uptake in patients with moderate heart failure is a predictor of poor outcome, a finding consistent with SPECT MIBG studies [137]. HED PET imaging demonstrates reinnervation of the transplanted heart [138] paralleling recovery of primarily fatty acids metabolism after an initial metabolic shift from fatty acids to glucose utilization associated with myocardial denervation [139]. 

During Fasting and Starvation, Metabolism Shifts to Provide Fuel for the Brain... 

Physical therapists and occupational therapists may help reinforce the importance of patient compliance during pharmacologic management of diabetes mellitus. Therapists can question whether patients have been taking their medications on a routine basis. Regular administration of insulin is essential in preventing a metabolic shift toward ketone body production and subsequent ketoacidosis, especially in patients with type 1 diabetes. In addition, therapists can help explain that adequate control of blood glucose not only prevents acute metabolic problems but also seems to decrease the incidence of the neurovascular complications. 

Studies of the respiratory quotient or respiratory exchange ratio (RER) indicate a metabolic shift in CR rats depending on food availability, while there is little change in AL rats [21,42]. Figure 7 illustrates daily variations of RER with dietary regimen. Analysis of the food composition indicates an expected average value of RER of 0.89. RER in AL rats is 0.89 0.02 over a 24-hour period and is relatively more constant than that in CR rats, indicating that AL rats metabolize a constant ratio of carbohydrate and lipid over 24 hours [21, 42]. In contrast, CR animals metabolize more carbohydrate... 

It is tempting to speculate if metabolic shifts and shifts in the physiological state of the culture can be more precisely monitored with the electronic nose. Physiologically important odorant metabolites in antibiotic strains such as geosmin and oxolone have been analyzed with conventional methods in the fermentation off-gas [38]. Recently, responses from electronic noses have been possible to relate to plasmid copy number [39]. Other types of intracellular shifts, such as viral infection, inclusion body formation or increase in mRNA level, could challenge the capacity of electronic noses. 

The activities of intracellular enzymes give an indication of the activity of certain metabolic pathways. They are classically assayed by performing their specific reactions in vitro, using the conversion of natural or artificial substrates and often some additional detection reaction. The sample preparation procedure involves cell harvesting and preparation of cell extracts. A well-studied example is the metabolic shift in Clostridium acetobutylicum from acid to solvent production, the so-called solvent shift. Andersch et al. [48] studied the activities of 10 different enzymes involved in this shift, in batch cultivations where the shift is self-induced by the products formed, and under continuous culture conditions with an externally induced shift. 

The plentiful supply of fat causes a metabolic shift from primarily burning carbs to primarily burning fats. Insulin levels remains low (which increases GH release). Increased dietary fat is also linked to increased testosterone levels. 

Girbal, L., Croux, C., Vasconcelos, I., and Soucaille, P. (1995) Regulation of metabolic shifts in Clostridium acetobutylicum ATCC 824. FEMS Microbiol. Rev., 17, 287-297. 

G. (1978) A better cell line for making hybridomas secreting specific antibodies. Nature, 276, 269 -270. Niklas, )., Schrader, E., Sandig, V., Noll, T. et al. (2011) Quantitative characterization of metabolism and metabolic shifts during growth of the new human cell line AGEl.HN using time resolved metabolic flux analysis. Bioprocess. Biosyst. Eng, 34, 533-545. 

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