Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0037315 (sleep apnea)
 8,000 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This paper examines the feasibility of accurate state classification of autonomic nervous activity (ANA) based on the power spectral pattern of the heart rate fluctuations (HRFs). Some attempts have been made to utilize artificial neural networks (ANNs) to classify HRFs for clinical diagnoses such as ischemic cardiomyopathy, arrhythmia or sleep apnea. To establish the firm bases for making such clinical diagnoses, it may be important to examine the classification accuracy for the data in physiologically well defined conditions by e.g. application of autonomic blocking agents. In this paper the three layered perceptron has been trained by the heart rate data in variety of ANS states yielded by the application of Atropine and Propranolol to 14 healthy male subjects. Six state (control, atropine and propranolol for each of the spine and upright posture) classification based on power spectrum showed average sensitivity of 67.2% and specificity 91.2%. Four state (control, atropine, propranolol and double block for either spine or upright posture) resulted in the average classification sensitivity of 75.7% and specificity 95.5%. The paper revealed that entropy bandwidth and indices originated from characteristic oscillations of blood pressure change improve the classification accuracy.
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PMID:State classification of heart rate variability by an artificial neural network in frequency domain. 2109 42

The multidrug efflux pump P-glycoprotein (Pgp) is upregulated in cardiomyocytes following chronic ischemia from infarction and hypoxia caused by sleep apnea. This report summarizes the molecular dynamic studies performed on eight cardiovascular drugs to determine their corresponding binding sites on mouse Pgp. Selected Pgp transport ligands include: Amiodarone, Bepridil, Diltiazem, Dipyridamole, Nicardipine, Nifedipine, Propranolol, and Quinidine. Extensive molecular dynamic equilibration simulations were performed to determine drug docking interactions. Distinct binding sites were not observed, but rather a binding belt was seen with multiple residues playing a role in each studied drug's stable docking. Three key drug-protein interactions were identified: hydrogen bonding, hydrophobic packing, and the formation of a "cage" of aromatic residues around the drug. After drug stabilization, water molecules were observed to leak into the binding belt and condense around the drug. Water influx into the binding domain of Pgp may play a role in catalytic transition and drug expulsion. The cytoplasmic recruitment theory was also tested, and the drugs were observed to interact with conserved loops of residues with a strong affinity. A free energy change of astronomical value is required to recruit the drug from the cytoplasm to the binding belt within the transmembrane domain of Pgp.
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PMID:Characterizing the binding interactions between P-glycoprotein and eight known cardiovascular transport substrates. 2572 81