Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epidemics of epilepsy, a form of mass hysteria, were known in Eastern and Western cultures in the 17th and 18th centuries. A unique situation in the United States during the 19th centurey was the frontier religious movement, the setting in which the "jerks" occurred. The "falling exercise," "dancing exercise," "barking exercise," "laughing exercise," and the "running exercise" centered around the excitement involved in the religious revival. During some exercises, people saw "visions," and exhibited bizarre behavior and sudden jerking motions. During the summers of 1801-1803 on the Kentucky frontier, some pioneers who attended the religious revival camp meetings had convulsions, hallucinations, tremors, jerks, compulsive dancing and "epileptic trances." Although these have been assumed to be psychological in origin, the epidemiology of the symptoms may correlate with the diagnosis of ergotism. Those affected were usually children and young adults. Symptoms of ergotism include giddiness, fatigue, depression, formications, muscle twitching, tonic spasms, convulsions, delirium, and loss of speech.
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PMID:Ergot, the "jerks," and revivals. 636 76

We evaluated the possible role of prostaglandin E2 (PGE2) in the calcium(Ca++)-mediated damage of skeletal muscle by a calcium ionophore (A23187) that induces excessive Ca++ influx. Twitch and tetanus of rat diaphragms were depressed with either PGE2 or A23187. A23187-induced depression was reduced by PG synthesis inhibitors, aspirin, or indomethacin, though less than that by a protease inhibitor, leupeptin. PGE2-induced depression was also inhibited by leupeptin. Damage of the muscle cell by excessive intracellular free Ca++ may thus be mediated via a PGE2 pathway besides other mechanisms including non-lysosomal, Ca++-activated proteases.
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PMID:Role of prostaglandin E2 in contractile abnormality induced by calcium ionophore, A23187. 641 48

The effects on indirectly elicited muscle twitch amplitude associated with the calcium (slow) channel blocker, verapamil, with or without pancuronium were investigated using isolated bullfrog sciatic nerve-sartorius muscle preparations. Verapamil (2-8 mM) produced a dose-related depression of indirect muscle twitch height (P less than 0.05). Twitch response was depressed 11% below control by the lowest concentration employed and 86% by the highest concentration. Pancuronium (0.07 mM) depressed neuromuscular function 35% below control (P less than 0.05). The combination of 5 mM or 8 mM verapamil with 0.07 mM pancuronium caused significantly greater degrees of depression than either drug alone. Verapamil produced significant depression of twitch height in vitro in relatively high concentrations. The mechanism of action remains unknown. Verapamil possesses pharmacologic properties that may be unrelated to slow (calcium) channel inhibition. The reduction of muscle twitch height caused by verapamil alone (5 mM) could not be antagonized by neostigmine, calcium, or frequent washings.
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PMID:Effects of verapamil on indirect muscle twitch responses. 660 98

Leaves of Kalanchoe daigremontiana, K tubiflora, K fedtschenkoi, K tomentosa, K tomentosa X K beharensis, and 4 cultivars of K blossfeldiana were tested for toxicity to 2-week-old Leghorn chicks. These species were analyzed for percentage of alkaloids, aliphatic nitro compounds, soluble oxalates, and nitrates and were examined qualitatively for cyanogenic glycosides. The solubility of the toxic principle in K daigremontiana was determined. Leaves of K daigremontiana, K tubiflora, and K fedtschenkoi were toxic to chicks at dosage levels of 8 to 12 mg/g of body weight. Toxic signs included depression, muscular incoordination, twitching and spiraling of the neck, tremors, convulsions, paralysis, and death. Kalanchoe tomentosa, K tomentosa X K beharensis, and 4 cultivars of K blossfeldiana were nontoxic at the highest dosage levels tested. Aliphatic nitro compounds and cyanogenic glycosides were not detected in any species. Alkaloids, nitrates, and soluble oxalates were present only in nontoxic concentrations. The toxic principle in K daigremontiana was soluble in 50%, 80%, and 100% ethanol, slightly soluble in water and acetone, and insoluble in benzene, chloroform, and ether.
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PMID:Toxicity of Kalanchoe spp to chicks. 671 83

Because severe muscular weakness was noted in animals receiving verapamil in doses exceeding those used in humans, we studied the effects of verapamil on neuromuscular function and its correlation with myocardial conduction. The flexor carpi radialis and its nerves were surgically exposed in mechanically ventilated dogs during pentobarbital anesthesia. Indirect and direct electrical stimulation was applied and twitch height recorded following the intravenous administration of verapamil. Twenty animals received one of four dose schedules. The results showed a significant dose-related depression of twitch height to indirect stimulation. Twitch height to direct stimulation was reduced only with the highest dose. The onset of depression of indirect stimulation was temporally associated with onset of A-V conduction delay. However, recovery following indirect stimulation lagged behind recovery of the ECG by 30 min. Recovery times of twitch height following indirect stimulation ranged from 60-208 min and also were dose-related. The qualitative similarity of pancuronium and verapamil on indirect twitch height suggests a similar site of action, i.e., the neuromuscular junction. A presynaptic or postsynaptic effect of verapamil could not be discerned in this study. Verapamil may produce an unrecognized source of weakness in the anesthetized patient either alone or through interaction with anesthetic agents or adjuncts.
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PMID:Neuromuscular and electrocardiographic responses to verapamil in dogs. 684 9

Twitch and tetanic contractions of single motor units of the cat peroneus tertius muscle were examined after application of a test allowing their identification as either fast fatigable (f.f.) or fast fatigue-resistant (f.r.) or fast intermediate (f.i.) or slow units as established by Burke, Levine, Tsairis & Zajac (1973). The test was found to leave two kinds of after-effects in f.f., f.r. and f.i. units whereas it did not affect slow units. The first after-effect was an early and brief potentiation of twitch tension occurring in all f.r. and f.i. units and in most f.f. units. The second after-effect, termed 'delayed fatigue', was a prolonged depression of tension output, that developed slowly following the early potentiation in all f.f. and f.i. units and more than half of the f.r. units. One hour after the test, unfused tetanic contractions elicited by 20-40/sec stimulation were deeply depressed in motor units that had been left without stimulation since the end of the test. Recovery took place in 3-5 hr. Motor units affected by delayed fatigue could nevertheless be made to develop nearly normal tension by gradual build-up upon prolonged stimulation at 30-40/sec. Maximal tetanic contractions elicited by 200/sec stimulation were much less depressed during delayed fatigue than unfused tetanic contractions. These observations suggest that contractile mechanism were not impaired by delayed fatigue. Since absence of change in muscle action potential indicated that excitation of muscle fibres was not affected either, delayed fatigue might be due to a temporary failure of excitation-contraction coupling.
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PMID:After-effects of repetitive stimulation at low frequency on fast-contracting motor units of cat muscle. 688 44

Thumb adductor twitch response to train-of-four (2 Hz for 2 seconds) stimulation of the ulnar nerve was used to assess the clinical characteristics of long-term neuromuscular blockade induced with continuous infusion of succinylcholine during balanced (N2O-O2-narcotic-thiopental) anesthesia. Twitch depression of 80 to 90% was maintained for 86 to 365 minutes by continuous infusion of succinylcholine at 86 +/- 5(SEM) micrograms/kg/min. Of 32 patients, 24 developed phase II block, defined as a train-of-four ratio of less than 50%. There was a large degree of individual variability in sensitivity to development of phase II block. This precluded defining a narrow dose range where transition from phase I to phase II occurred. Tachyphylaxis occurred in 25% of patients and was independent of the type of block. Neither dose nor duration of infusion was predictive of spontaneous recovery rate from phase II block. Of 24 patients who developed phase II block, 50% recovered spontaneously at a rate comparable to the recovery rate from a phase I block. The other 50% manifested prolonged recovery of neuromuscular function. After observing spontaneous recovery in these patients for 31 +/- 5(SEM) minutes, successful antagonism of residual phase II block with anticholinesterase agents was achieved.
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PMID:Clinical characteristics of long-term succinylcholine neuromuscular blockade during balanced anesthesia. 718 31

Twitch, tetanus, and contractures induced by potassium ions (K+) or caffeine were investigated on isolated bundles of frog muscles. Using supramaximal stimuli the twitch amplitude amounts to about 50% of the tetanic tension (22 degrees C). Usually the contracture in 190 mM K+ is smaller than the tetanic tension, in 20 mM caffeine the contracture maximum corresponds to the tetanus amplitude. All of the mechanical answers are diminished if the fibres were bathed in solutions containing 2.5 to 10 mM Na-octanoate or 0.5 mM decanoic acid. Twitch and tetanic tensions decrease nearly in the same degree. A sequence of tetanic stimulations in a distance of 2 s induces a depression of the amplitudes. Fatty acids increase this depression and delay restoration between the series. Contractures in 190 mM K+ are diminished by a preceding bath in 10 mM Na-octanoate. Contractures with submaximum concentrations of K+ were decreased by lower concentrations of octanoate. The caffeine induced contractures are delayed by fatty acids, but the maximum tension is not reduced. It is supposed that the mobilisation of calcium ions is alterated by fatty acids. The decreasing effect of fatty acids on the mechanical activity, induced by different ways of the muscles' stimulation suggests that the main action may take place in the process of mechanical coupling, probably during the activation of calcium ions.
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PMID:[Effect of homologous n-alkanoic acids on the function of isolated skeletal muscles. V. Relations between twitch, tetanus and contracture]. 744 6

This study investigates the effects of alkylxanthines on twitch tension generated by electrical stimulation (supramaximal pulses, 0.2 ms duration, 1 Hz) of diaphragm muscle fibres isolated from normal and actively-sensitized guinea-pigs. Caffeine, theophylline and theobromine increased, in a concentration-dependent manner (50-500 microM), twitch tension in normal and sensitized diaphragm. Caffeine (500 microM) enhanced contractility to a greater extent than theophylline or theobromine. Twitch potentiation by caffeine (500 microM) was significantly greater in sensitized diaphragm. Verapamil (0.1-100 microM) did not alter twitch contractions in the absence or presence of alkylxanthines in normal or sensitized strips. Dantrolene (0.01-100 microM) depressed, in a concentration-dependent fashion, twitch contractions of normal and sensitized diaphragm. The inhibitory concentration 50% (expressed as -log IC50) was 6.78 +/- 0.13 in normal tissues and 6.15 +/- 0.11 in sensitized tissues (n = 6 in each group; P < 0.05). Exposure to Ca(2+)-free, EGTA (0.1 mM)-containing medium, depressed twitch contraction of normal diaphragm to a lesser extent than that of sensitized diaphragm. Methylxanthines reversed depression of twitch contractions produced by exposure to dantrolene (5 microM) or a Ca(2+)-free medium. Adenosine (1-1000 microM) was without effect whereas enprofylline (50-500 microM) enhanced diaphragm contractility in normal tissues. This indicates that blockade of adenosine receptors is not involved in the inotropic effect of alkylxanthines in guinea-pig diaphragm. Results from this study suggest that alkylxanthines enhance diaphragm contractility in the guinea-pig by releasing intracellular Ca2+ and promoting extracellular Ca2+ entry through verapamil-insensitive pathways. An alteration of Ca2+ movements and stores may be present in the sensitized diaphragm.
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PMID:Effects of alkylxanthines on contractility of diaphragm fibres isolated from normal and sensitized guinea-pigs. 790 75

The influence of acidosis on adenosine output from the isolated constant-flow-perfused gracilis muscle was studied in anesthetized dogs. Depression of intracellular pH (pHi) by supplementation of the inspired air with 10% CO2-90% O2 increased arterial PCO2 from 34.2 +/- 1.0 to 53.5 +/- 1.9 mmHg, arterial PO2 from 138.3 +/- 3.9 to 256.6 +/- 17.6 mmHg, and venoarterial adenosine concentration from 14 +/- 15 to 47 +/- 19 nM. Twitch contractions of the muscle at 2 Hz increased venoarterial adenosine concentration to 165 +/- 63 and 204 +/- 62 nM in normocapnia and hypercapnia, respectively. Venoarterial lactate concentration increased from 0.42 +/- 0.07 to 0.90 +/- 0.15 mM during normocapnic contractions but remained unchanged during hypercapnic contractions (0.42 +/- 0.11 mM). Depression of pHi by infusion of amiloride and 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid increased venoarterial adenosine concentration from -2 +/- 27 to 124 +/- 48 nM in normocapnia and from 16 +/- 24 to 236 +/- 119 nM in hypercapnia. These results indicate that adenosine output from red oxidative skeletal muscle was stimulated by procedures that depress pHi.
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PMID:Adenosine output from dog gracilis muscle during systemic hypercapnia and/or amiloride-SITS infusion. 794 67


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