Dynamic syndromes

Metabolic disorders of muscle include those of glycogen storage, substrate transport and utilization, and electron transport chain and ATP metabolism. Some produce dynamic syndromes with symptoms occurring primarily during exertion, some cause degenerative syndromes, and some produce both. A few are discussed below. 

Myophosphorylase deficiency is the classic example of a carbohydrate-related dynamic syndrome. Affected persons are unable to mobilize glycogen therefore they cannot perform high-intensity work and must rely extensively on lipid metabolism. Several other defects of glycolysis produce similar symptoms. All are characterized by inability to do anaerobic work and to produce lactate during ischemic exercise, which is the basis for the customary screening test for these disorders. Patients are asked to perform maximal hand grip contractions at the rate of one per second for 60 seconds with the forearm circulation... 

Trinucleotide sequences that increase in number (microsateUite instability) can cause disease. The unstable p(CGG) repeat sequence is associated with the fragile X syndrome. Other trinucleotide repeats that undergo dynamic mutation (usually an increase) are associated with Huntington s chorea (CAG), myotonic dystrophy (CTG), spinobulbar muscular atrophy (CAG), and Kennedy s disease (CAG). 

Overall importance of the syndrome-based approach is that it may serve as a promising starting point for the development of indicators for early warning and intervention in the conflict dynamic and may provide the... 

Lande, G., Kyndt, F., Baro, I., Chabannes, D., Boisseau, P., Pony, J.C., Escande, D. and Le Marec, H. (2001) Dynamic analysis of the QT interval in long QT1 syndrome patients with a normal phenotype. European Heart Journal, 22, 410-422. 

For some parameter values the model for the mammalian clock fails to allow entrainment by 24-h LD cycles, regardless of the amplitude of the light-induced change in Per expression. The question arises whether there exists a syndrome corresponding to this mode of dynamic behavior predicted by the model. Indeed there exists such a syndrome, known as the non-24-h sleep-wake syndrome, in which the phase of the sleep-wake pattern continuously varies with respect to the LD cycle that is, the patient free-runs in LD conditions [117]. Disorders of the sleep-wake cycle associated with alterations in the dynamics of the circadian clock belong to the broad class of dynamical diseases [122, 123], although the term syndrome seems more appropriate for some of these conditions. 

Most estimates of diuretic binding to albumin assume that the protein itself is not altered as part of the disease process. In renal failure, however, the number of binding sites on the protein may change, which in turn affects the pharmacokinetics and dynamics of the response to an administered diuretic. Another setting associated with diminished effective diuretic concentrations occurs in nephrotic syndrome. In this disease, protein escaping from the glomerulus into the tubules binds the diuretic within the lumen. The bound drug is unavailable to exert its inhibitory effect on sodium transport. 

Peterson, B.S., and Leckman, J.R (1998) The temporal dynamics of tics in Gilles de la Tourette syndrome. Biol Psychiatry 44 1337-1348. 

Fibrillin microfibrils are widely distributed extracellular matrix assemblies that endow elastic and non elastic connective tissues with long-range elasticity. They direct tropoelastin deposition during elastic fibrillogenesis and form an outer mantle for mature elastic fibers. Microfibril arrays are also abundant in dynamic tissues that do not express elastin, such as the ciliary zonules of the eye. Mutations in fibrillin-1—the principal structural component of microfibrils—cause Marfan syndrome, a heritable disease with severe aortic, ocular, and skeletal defects. Isolated fibrillin-rich microfibrils have a complex 56 nm beads-on-a-string appearance the molecular basis of their assembly and... 

Heeschen C, Hamm CW, MhrovicV etal. N-terminal pro-B-type natriuretic peptide levels for dynamic risk stratification of patients with acute coronary syndromes. Circulation 2004 ... 

Fig. 6. Hypothesis model representing the switching off and on of the FMR1 gene in X-fragile syndrome as a function of DNA structural dynamics...

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