Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

During December 1993-September 1995, the Bureau of Food and Drug Safety, Texas Department of Health (TDH), received approximately 500 reports of adverse events in persons who consumed dietary supplement products containing ephedrine and associated alkaloids (pseudoephedrine, norephedrine, and N-methyl ephedrine). This total included reports by individuals and reports identified by the Bureau of Epidemiology, TDH, in a review of records from the six centers of the Texas Poison Center Network. Reported adverse events ranged in severity from tremor and headache to death in eight ephedrine users and included reports of stroke, myocardial infarction, chest pain, seizures, insomnia, nausea and vomiting, fatigue, and dizziness. Seven of the eight reported fatalities were attributed to myocardial infarction or cerebrovascular accident. This report describes three patients in which the recommended dosage for the dietary supplements reportedly was not exceeded, summarizes results from ongoing investigations, and underscores the potential health risks associated with the use of products containing ephedrine.
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PMID:Adverse events associated with ephedrine-containing products--Texas, December 1993-September 1995. 877 3

Oxidative stress is defined as a disturbance in the prooxidant-antioxidant balance in favor of the former and has been suggested to be a relevant factor in aging as well as in different pathological conditions, such as heart attack, diabetes, and cancer. Ubiquinol is very sensitive against oxygen radicals and gives ubiquinone as an oxidation product. Therefore, the ratio of ubiquinol to ubiquinone should be a good marker of oxidative stress because of its definition. A method for the simultaneous detection of ubiquinol-10 and ubiquinone-10 in human plasma is described. Heparinized human plasma was mixed with 5 volumes of methanol and 10 volumes of hexane. After vigorous shaking and centrifugation, the hexane phase (5 microliters) was injected immediately and directly on to reverse-phase HPLC equipped with an on-line reduction column and an electrochemical detector in order to avoid the oxidation of ubiquinol to ubiquinone. It was found that the ratio of ubiquinol-10 to ubiquinone-10 was about 95/5 in human plasma from healthy donors. A significant increase in the oxidized form (ubiquinone-10) content was observed in plasmas of patients with hepatitis, cirrhosis, and hepatoma when compared with normal subjects, suggesting increased oxidative stress in these patients.
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PMID:Plasma ratio of ubiquinol and ubiquinone as a marker of oxidative stress. 926 9

Beta-adrenoceptors are members of a large family of hormone and neurotransmitter receptors that initiate their biological function by coupling to GTP-binding regulatory proteins. beta-Adrenoceptors can be subdivided into two main subgroups, designated beta1 and beta2. Atypical beta-adrenoceptors or beta3-adrenoceptors, which are present on adipocytes, have been demonstrated pharmacologically. Their function in adipose tissue is currently being investigated. Beta2-adrenoceptor agonists have played a key role in the treatment of asthma for some 30 years, being used for the relief and prophylaxis of symptoms. There is, however, no evidence that tolerance to the bronchodilator or anti-bronchoconstrictor effects of these drugs is responsible for the deleterious effects reported with the regular use of bronchodilators. In neuropsychiatry, beta-adrenoceptor antagonists have been used for the treatment of acute stress reactions and generalised anxiety, essential tremor and prophylaxis of migraine. In general, they are effective in anxiety disorders if the somatic symptoms are not extreme. For prophylactic treatment of migraine, beta-adrenoceptor antagonists such as propranolol, metoprolol, nadolol and atenolol are the drugs of first choice. In cardiology, beta-adrenoceptor antagonists are an important class for the treatment of high blood pressure, arrhythmias and angina pectoris, and for prevention of myocardial infarction. With chronic treatment, they reduce mortality in hypertension and prolong survival in patients with coronary heart disease.
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PMID:Current therapeutic uses and potential of beta-adrenoceptor agonists and antagonists. 955 98

A 59-year-old woman suffered from prolonged hypotension with myocardial infarction. Sixteen days after the episode, she showed bradykinesia, gait disturbance, and postural tremor. MRI revealed low signa intensities in the bilateral caudate nuclei and putamen on the T1-weighted image and high signal intensities on the T2-weighted image. PET with 18F-FDG revealed a severe decrease in glucose metabolism in bilateral basal ganglia. It is concluded that prolonged hypotension may induce localized delayed anoxic lesions in basal ganglia.
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PMID:Neuroimaging on delayed postanoxic encephalopathy with lesions localized in basal ganglia. 955 30

Selection of beta-adrenergic blockers for formulary addition can be a difficult task, especially with the increasing availability of new beta-blockers, as well as the numerous differences in pharmacodynamic and pharmacokinetic properties of currently available agents. Nevertheless, appropriate evaluation of the important characteristics of beta-blockers should allow selection of the most cost-effective agents for formulary addition. Most importantly, differences in efficacy, product formulation and cost should be carefully considered when making formulary decisions. Notably, evidence from clinical trials indicates differences in efficacy among beta-blockers for post-myocardial infarction prophylaxis, situational anxiety, essential tremor, thyrotoxicosis, migraine prophylaxis and prevention of bleeding associated with oesophageal varices. For many clinical situations, it is also important to select an effective agent that is available in both an oral and intravenous formulation, especially for cardioprotection after acute myocardial infarction and for use in supraventricular arrhythmias. In addition, availability of sustained release products and generic formulations should be considered for their potential to increase compliance and decrease cost, respectively. Comparative drug costs, as well as costs associated with decreased compliance, should also be carefully evaluated. Differences in beta-receptor selectivity, duration of action and presence of intrinsic sympathomimetic activity (ISA) are also important considerations in the selection of beta-blockers for formulary consideration. Although degree of selectivity is relative, beta 1-selective agents may be less likely to induce bronchospasm in patients with chronic obstructive pulmonary disease (COPD) and may be less likely to affect glucose homeostasis in patients with diabetes mellitus. Duration of action of a beta-blocker is an important consideration for evaluation of efficacy throughout the recommended dosage interval. In addition, beta-blockers with a long duration of action can often be administered once or twice daily, potentially leading to increased compliance and thereby improved effectiveness and economic efficiency. The presence of ISA is an important consideration because certain beta-blockers with ISA may be less effective than those without ISA for certain indications. Factors considered to be less important when making formulary decisions of choice of beta-blockers include the route of elimination, lipophilicity and presence of membrane stabilising activity.
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PMID:Formulary considerations in selection of beta-blockers. 1015 Jan 54

Beta-adrenergic-blocking drugs (BABs) have a firm place in the therapy of cardiovascular conditions including angina and hypertension. Although all BABs are competitive inhibitors of beta-receptors, they may differ in their additional pharmacodynamics, i.e., beta1-(cardio)selectivity, partial agonistic activity (PAA), and pharmacokinetic properties. Understanding these additional properties would allow the physician to choose the more appropriate agent for some patients or for specific situations. beta1-Selective BABs may be of potential importance in patients with obstructive airway disease, peripheral vascular disease, and hyperlipidemia and in diabetic patients receiving antidiabetic drugs. These BABs may better control the increased blood pressure in response to hypoglycemia, exercise, or cigarette smoking. Nonselective BABs may be preferably used to decrease epinephrine-induced hypokalemia or to prevent myocardial infarction, and in certain circumstances (i.e., migraine, anxiety, thyrotoxicosis or essential tremor). BABs with PAA may theoretically cause a lesser degree of cardiodepression (reduction of heart rate at rest, cardiac output, and AV conduction), bronchospasm, and peripheral vasoconstriction and minor effects on plasma lipids. Withdrawal syndrome may be absent after BABs with PAA. The pharmacokinetic properties of the BABs such as absorption, bioavailability, elimination half-life, liver metabolization, interindividual variability, as well as pharmacological interactions depend on their hydrophilic/lipophilic ratio. The development of new BABs continues. It has been possible to incorporate into a drug molecule combinations of PAA, preferred beta1-blockade, and beta2-agonist activity. Even if these new agents cause less adverse effects (e.g., vasoconstriction, bronchospasm), their clinical significance remains to be established.
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PMID:Optimization of beta-blockers' pharmacology. 1152 10

Pheochromocytomas classically present with paroxysms of hypertension and adrenergic symptoms including headaches, palpitations, tremor, and anxiety. However, these tumors can be clinically silent and occasionally present only when catecholamine release is up-regulated by exogenous stimuli. In addition, the clinical presentation of pheochromocytoma can mimic a number of more common medical conditions, including migraine headaches, cardiac arrhythmias, and myocardial infarction, making diagnosis difficult. In this report, we present the case of a young woman who, while receiving oral corticosteroid therapy for presumed migraine headaches, suffered a myocardial infarction and ultimately hemorrhaged into a previously undiagnosed pheochromocytoma. Our patient exhibited severe, labile hypertension after the administration of iv beta-blockade for presumed myocardial ischemia, raising our initial clinical suspicion for pheochromocytoma. In this paper we review some of the key clinical issues related to this complex case, including steroid-induced stimulation of catecholamine synthesis and release, the role of pheochromocytoma in myocardial ischemia and electrocardiographic changes, and the rare complication of tumor hemorrhage. We then briefly review the essential diagnostic and management strategies for this rare but potentially lethal tumor, with specific emphasis on pheochromocytoma-related cardiovascular emergencies and the surgical management of tumor hemorrhage.
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PMID:Hemorrhagic pheochromocytoma associated with systemic corticosteroid therapy and presenting as myocardial infarction with severe hypertension. 1591 34

Asthma and chronic obstructive pulmonary disease (COPD) are common disorders that are associated with increasing morbidity and mortality in older people. Bronchodilators are used widely in patients with these conditions, but even when used in inhaled form can have systemic as well as local effects. Older people experience more adverse drug effects because of pharmacodynamic and pharmacokinetic changes and particularly drug-drug and drug-disease interactions. Cardiovascular disease is common in older people and beta-adrenoceptor agonists (beta-agonists) have inotropic and chronotropic effects that can increase arrhythmias and cardiomyopathy. They can also worsen or induce myocardial ischaemia and cause electrolyte disturbances that contribute to arrhythmias. Tremor is a well known distressing adverse effect of beta-agonist administration. Long-term beta-agonist use can be associated with tolerance, poor disease control, sudden life-threatening exacerbations and asthma-related deaths. Functional beta2-adrenoceptors are present in osteoblasts, and chronic use of beta-agonists has been implicated in osteoporosis. Inhaled anticholinergics are usually well tolerated but may cause dry mouth, which can be troublesome in older people. Pupillary dilatation, blurred vision and acute glaucoma can occur from escape of droplets from loosely fitting nebulizer masks. Although ECG changes have not been seen in randomized controlled trials of long-acting inhaled anticholinergics, supraventricular tachycardias have been observed in a 5-year randomized controlled trial of ipratropium bromide. Paradoxical bronchoconstriction can occur with inhaled anticholinergics as well as with beta-agonists, but tolerance has not been reported with anticholinergics. Anticholinergic drugs also cause central effects, most notably impairment of cognitive function, and these effects have been noted with inhaled agents. Use of theophylline is limited by its adverse effects, which range from commonly occurring gastrointestinal symptoms to palpitations, arrhythmias and reports of myocardial infarction. Seizures have been reported, but are rare. Theophylline is metabolized primarily by the liver, and commonly interacts with other medications. Its concentration in plasma should be monitored closely, especially in older people. Although many clinical trials have been conducted on bronchodilators in obstructive airways disease, the results of these clinical trials need to be interpreted with caution as older people are often under-represented and subjects with co-morbidities actively excluded from these trials.
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PMID:Potential adverse effects of bronchodilators in the treatment of airways obstruction in older people: recommendations for prescribing. 1844 5

The baroreceptor reflex buffers autonomic changes by decreasing sympathetic activity and increasing vagal activity in response to blood pressure elevations, and by the reverse actions when the blood pressure falls. Because of the many bidirectional interactions of pain and autonomic function, we investigated the effect of painful nerve injury by spinal nerve ligation (SNL) on heart rate (HR), blood pressure (BP) and their regulation by the baroreceptor reflex. Rats receiving SNL were separated into either a hyperalgesic group that developed sustained lifting, shaking and grooming of the foot after plantar punctate nociceptive stimulation by pin touch or a group of animals that failed to show this hyperalgesic behavior after SNL. SNL produced no effect on resting BP recorded telemetrically in unrestrained rats compared to control rats receiving either skin incision or sham SNL. However, two tests of baroreceptor gain showed depression only in animals that developed sustained hyperalgesia after SNL. The animals that failed to develop hyperalgesia after SNL were found to have elevations in HR both before and for the first 4 days after SNL, and HR variability analysis gave indications of decreased vagal control of resting HR and elevated sympatho-vagal balance at these same time intervals. In human patients, other research has shown that blunted baroreceptor reflex sensitivity predicts poor outcome during conditions such as hypertension, congestive heart failure, myocardial infarction, and stroke. If baroreceptor reflex suppression is also found in human subjects during chronic neuropathic pain, this may adversely affect survival.
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PMID:Baroreceptor reflex is suppressed in rats that develop hyperalgesia behavior after nerve injury. 1972 45

Myocardial infarction (MI), is commonly known as a heart attack, occurs when the blood supply to the portion of the heart is blocked causing some heart cells to die. This information is depicted in the elevated ST wave, increased Q wave amplitude and inverted T wave of the electrocardiogram (ECG) signal. ECG signals are prone to noise during acquisition due to electrode movement, muscle tremor, power line interference and baseline wander. Hence, it becomes difficult to decipher the information about the cardiac state from the morphological changes in the ECG signal. These signals can be analyzed using different signal processing techniques. In this work, we have used multiresolution properties of wavelet transformation because it is suitable tool for interpretation of subtle changes in the ECG signal. We have analyzed the normal and MI ECG signals. ECG signal is decomposed into various resolution levels using the discrete wavelet transform (DWT) method. The entropy in the wavelet domain is computed and the energy-entropy characteristics are compared for 2282 normal and 718 MI beats. Our proposed method is able to detect the normal and MI ECG beat with more than 95% accuracy.
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PMID:Analysis of myocardial infarction using discrete wavelet transform. 2070 9


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