Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

One of several factors suspected in the development of lateral epicondylitis, often referred to as tennis elbow, is the impact-induced vibration of the racket-and-arm system at ball contact. Using two miniature accelerometers at the wrist and the elbow of 24 tennis players, the effects of 23 different tennis racket constructions were evaluated in a simulated backhand stroke situation. The influences of body weight, skill level, and tennis racket construction onto the magnitude of vibrations at wrist and elbow were investigated. Amplitudes, integrals, and fourier components were used to characterize arm vibration. More than fourfold reductions in acceleration amplitude and integral were found between wrist and elbow. Off-center as compared with center ball impacts resulted in approximately three times increased acceleration values. Between subjects, body weight as well as skill level were found to influence arm vibration. Compared with proficient players, a group of less skilled subjects demonstrated increased vibration loads on the arm. Between different racket constructions, almost threefold differences in acceleration values could be observed. Increased racket head size as well as a higher resonance frequency of the racket were found to reduce arm vibration. The vibration at the arm after ball impact showed a strong inverse relationship (r = -0.88) with the resonance frequency of tennis rackets.
 ...
PMID:Transfer of tennis racket vibrations onto the human forearm. 143 61

The plasminogen-plasmin enzyme system and its therapeutic manipulation provide the substrate for an assessment of the clinical use of thrombolytic agents. Proven effective in acute MI and its complications, such agents have other potential applications--e.g., in stroke or pulmonary embolism--and are being investigated in those contexts.
Hosp Pract (Off Ed) 1992 Jun 15
PMID:Thrombolytic therapy: a state of the art review. 152 55

Atrial fibrillation has been found to be a significant risk factor for stroke independent of the contribution this common arrhythmia makes via its previously established stroke risk factors. Results of four recent trials in patients with nonrheumatic atrial fibrillation show that warfarin anticoagulant therapy can substantially reduce the risk of stroke without major bleeding complications.
Hosp Pract (Off Ed) 1991 Nov 15
PMID:Atrial fibrillation: new findings about an old nemesis. 154 49

A new training device derived from the MAD-system (system to measure active drag, Hollander et al. (8], providing fixed push off points in the water for swimming, the front crawl is described. The effects of training on this device (called POP from fixed Push Off Point) are determined by comparing the increase in performance of a training group (n = 11) to a control group (n = 11). The control group continued the normal training program. During ten weeks the training group followed the same program, but three times per week sprints performed on the POP were substituted for normal free swimming sprints. Despite the fact that training time and volume were equal, the training group showed a significantly greater improvement in force (from 91 to 94 N, 3.3%), velocity (from 1.75 to 1.81 m.s-1, 3.4%) and power (from 160 to 172 W, 7%) as measured on the MAD-system, and an increase in distance per stroke in free swimming. The training group showed a significant improvement in race times for 50 m (from 27.2 to 26.6 s), 100 m (from 59.3 to 57.4 s) and 200 m (from 129.6 to 127.3 s). It is concluded that the POP is a specific training device especially suitable for increasing maximal power output during swimming.
 ...
PMID:Effects of specific high resistance training in the water on competitive swimmers. 237 82

Tachycardia has been shown to be an important response involved in the maintenance of cardiac output during orthostasis at high altitude. This study was undertaken to determine if tachycardia, mediated by beta-adrenergic sympathetic stimulation, actually represents an essential response. Twelve young, healthy male subjects were administered either 80 mg propranolol (n = 6) or placebo (n = 6), t.i.d. at sea level and for 3 days (d) prior to and during the first 15 d of a 19-d altitude sojourn (On Treatment). Individuals were randomly assigned to each group. Upright tilt tests were performed at sea level and at high altitude during days 2, 7, and 15 On Treatment. Subjects were also tilt-tested at sea level and on day 19 of the altitude exposure without placebo or propranolol administration (Off Treatment). Heart rate, stroke volume, calf blood flow, and blood pressure were obtained during supine rest and after 12 min of 60 degrees tilt. We found no differences between groups in any of the circulatory measurements at sea level and altitude while Off Treatment. During the On Treatment phases at sea level and altitude, propranolol caused reductions in heart rate and blood pressure values in each position (p less than 0.05). Supine and upright cardiac output, however, were found not altered due to compensatory increases in stroke volume (p less than 0.05). We concluded that tachycardia, both at rest and during upright tilt at high altitude is important, but not essential to maintain cardiac output.
 ...
PMID:Propranolol and the compensatory circulatory responses to orthostasis at high altitude. 281 94

Changes in potassium levels clearly have hemodynamic significance. In mechanistic terms, they affect the transmembrane potential of vascular smooth muscle cells. They also influence the levels and activity of pressor hormones and of intracellular messengers involved in vasoconstriction. Furthermore, they alter the body's handling of sodium. As the net result, perhaps, of these phenomena, chronic supplementation of dietary potassium is associated with a small but appreciable decline in blood pressure. In humans, the effect, which could be predicted epidemiologically, has been demonstrated in studies of potassium administration in hypertensive patients. In experimental animals, the effect is most pronounced in salt-sensitive models of hypertension. The studies done to date do not permit firm recommendations about modification of dietary potassium content for hypertensive patients. However, in certain clinical settings, potassium repletion even for mildly depressed levels is vitally important, and in other circumstances, excess potassium clearly is dangerous. Still, indications are emerging that potassium may be valuable in preventing renal damage and stroke, quite apart from any effect on hypertension itself. Continued investigation will be of great value in the effort to arrive at a firm understanding of the precise roles that potassium may play in the treatment of hypertension or the prevention of its sequelae.
Hosp Pract (Off Ed) 1988 Dec 15
PMID:Potassium: weighing the evidence for supplementation. 314 7

Initial toxicological safety evaluations of the insect repellent N,N-diethyl-m-toluamide (DEET) indicated a potential hypotensive effect. The current study was initiated in order to pursue this aspect of DEET toxicity and to elucidate potential mechanisms for this response. Sublethal intraperitoneal injections of DEET in anesthetized rats were found to decrease mean blood pressure and heart rate in a dose-related fashion. Doses ranged from 56 to 225 mg/kg. Dogs treated with 225 mg/kg of DEET exhibited a similar hypotension and bradycardia. Cardiac output was also significantly reduced but stroke volume and total peripheral resistance were not altered. Lead II ECG changes included small increases in P-R and Q-T intervals. In a series of pharmacological studies in rats, DEET was found to decrease the hypotension and bradycardia associated with acetylcholine injection; epinephrine, norepinephrine, and histamine responses were not altered. Atropine pretreatment reduced but did not eliminate the hypotensive effects of DEET.
 ...
PMID:Some cardiovascular effects of the insect repellent N,N-diethyl-m-toluamide (DEET). 317 73

This paper describes a driving assessment and training program that is primarily for patients discharged from the hospital and who may be experiencing residual impairment from some form of brain damage. Assessment is carried out by an occupational therapist and consists of several off-road tests (vision, reaction timing, computerized preview tracking test, general medical/psychological appraisal), and an on-road test. More than 300 patients have been seen since the program's inception in 1977, and trends indicated by their assessment results are: twice as many male as female referrals; a low fail rate among nonbrain-involved patients; diagnosis as a poor predictor of outcome; no significant difference between fail rates of right and left stroke patients; significant difference in average tracking task performance between the Pass, Borderline, and Fail assessment groups. Off-road testing complements, rather than replaces, on-road testing. Thirty-eight of the 300 patients were given special training, and 15 of these were unable to reach an acceptable level. This reflects a difficulty in predicting the outcome of unlicensed patients with severe disabilities.
 ...
PMID:Assessment and training of brain-damaged drivers. 665 Jun 48

The effect of dopamine (Dp) and dobutamine (Db) on myocardial and systemic blood flow (BF) distribution was compared in dogs being weaned from cardiopulmonary bypass (CPB) after 20 min of normothermic global myocardial ischemia. Drug infusions (10 mcg/kg/min) were begun and BF was measured (radiolabeled microspheres) prior to weaning and 60 min off CPB. On CPB: Pump flows, by design, were similar (100 ml/kg/min) in Dp, Db, and saline control (NS) dogs. Dp and Db significantly (p less than 0.05) increased myocardial BF. Dp did not alter renal, visceral, and skeletal muscle BF and only increased BF to the cervical spinal cord and medulla. Db, however, significantly reduced renal (-49%), splenci (-58%), pancreatic (-27%), and colonic (-47%) BF but increased perfusion in essentially all of the central nervous system. Off CPB: Cardiac output during Dp and Db infusions was significantly greater than NS dogs (107 +/- 7 vs 152 +/- 12 vs 82 +/- 10 ml/kg/min resp.); the greater increase for Db resulting from a larger stroke volume. Dp and Db significantly increased myocardial BF. Dp increased splenic (+77%), gastric (+139%), and gallbladder (+125%) BF but had no effect on renal, hepatic, skeletal muscle, and intestinal BF. Db infusion maintained renal BF similar to NS and elevated BF to most visceral organs. The results of this study show that the myocardium responded to inotropic stimulation despite the previous ischemic insult but the BF changes varied among regional vascular beds with Dp and Db infusions during and following CPB. Of the 2 drugs, Db showed the greater inotropic response off CPB, a similar increase in myocardial perfusion and greater visceral organ bloodflow.
 ...
PMID:Effects of dopamine and dobutamine on the myocardial and systemic circulation during and following cardiopulmonary bypass in dogs. 715 62

The short-term haemodynamic effects of terminating dopamine and/or a combination of noradrenaline and nitroglycerin infusions were studied in 21 patients in acute respiratory failure. Patients were studied during treatment and 10 min after infusions were stopped. Off treatment, stroke index and cardiac index decreased significantly from 40.2 to 36.9 ml m-2 (P < 0.02) and from 3.80 to 3.42 litres m-2 (P < 0.02), respectively. Cardiac filling pressures decreased significantly and systemic vascular resistance increased, when infusions were stopped. As to heart rate, mean arterial pressure, mean pulmonary arterial pressure, right and left ventricular ejection fraction there were no significant changes between the data obtained during and off treatment. Although the haemodynamic status was significantly better during treatment with dopamine and/or noradrenaline-nitroglycerin in some respects, the overall beneficial effects of inotropic support were much less than anticipated.
 ...
PMID:The effects of dopamine and noradrenaline on cardiovascular function in patients with acute respiratory failure. 817 29


1 2 3 4 5 6 7 8 Next >>