Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The most attractive feature of nuclear magnetic resonance spectroscopy (MRS) is the noninvasive and nondestructive measurement of chemical compounds in intact tissues. MRS already has many applications in comparative physiology, usually based on observation of 31P, since levels of phosphorus compounds indicate tissue energy status and are changed during exercise, fatigue, recovery, hypometabolism, anesthesia, hypoxia, hypercapnia, and osmotic and acid stress. Nuclei other than 31P may also be monitored, such as 1H, 13C, 15N, 19F, or 23Na, and applied in biological research. Particularly, 13C-MRS is interesting because it allows the analysis of metabolic pathways in living systems. Applications of MRS in comparative physiology and biochemistry are comprehensively discussed in this review. The main focus is on anaerobic metabolism during hypoxia, ischemia, and exercise. Species as widely different as slime molds, nematodes, frogs, turtles, and ducks have been studied by 31P-MRS. It is not surprising that striking species differences do occur, but many similarities are also observed. Unique is the occurrence of six different phosphagens with different values of Gibbs free energy in polychete worms The presence of a particular phosphagen may be related to the average oxygen tension within the tissues. Phosphagens and their kinases are also discussed in relation to hypercapnia and acid stress. Other topics discussed in this paper are enzyme kinetics, anesthetics, development and growth, parasitism, and the detection of previously unknown compounds.
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PMID:Nuclear magnetic resonance spectroscopy of living systems: applications in comparative physiology. 875 89

The mechanism of prolongation of sleeping (anesthesia) time after phenobarbital (PB) treatment was assessed in mice with ethionine (ET)-induced liver disorders (ET-treated group). The brain gamma-aminobutyric acid (GABA), glutamic acid (GLU), lactic acid (LA), and pyruvic acid (PA) levels were significantly higher in the ET-treated group than the control group. The ET-treated group showed an abnormal neurotransmission and a decrease in energy metabolism. After administration of PB (175 mg/kg, i.p.), sleeping time and the brain GABA, GLU, LA, PA, and PB levels at the awakening point were compared between ET-treated and control groups. Sleeping time in the ET-treated group was two times longer than that in the control group. At the awakening point, the brain GABA and LA levels in the ET-treated and control groups and the PA level in the ET-treated group were significantly lower than those without PB treatment; and the GLU level in the ET-treated group was significantly higher than that without PB treatment. The brain concentrations of PB in both groups remained the same for seven hr after PB treatment. There was no difference in the brain PB concentration between the two groups at the awakening point, although the ET-treated group showed impairment of excretion of PB at 18 hr of PB treatment. In conclusion, awakening is not directly correlated with a decrease in PB in the brain, but rather to changes in the brain GABA, GLU, and other substances, and an inhibition of the neurotransmission and decreased energy metabolism in the brain are considered to be involved in the prolongation of PB-induced sleeping time in the ET-treated mice.
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PMID:Sleeping time after phenobarbital treatment and the brain levels of gamma-aminobutyric acid and phenobarbital at the regaining of righting response point in ethionine-induced liver-disordered mice. 878 Sep 95

Hormonal and metabolic responses to electrically induced dynamic exercise were investigated in eight healthy young men with afferent neural influence from the legs blocked by epidural anesthesia (25 ml of 2% lidocaine) at L3-L4. This caused cutaneous sensory anesthesia below T8-T9 and complete paralysis of the legs. Cycling increased oxygen uptake to 1.90 +/- 0.13 (SE) l/min, and fatigue developed after 22.7 +/- 2.7 min. Compared with voluntary exercise at the same oxygen uptake and heart rate, concentrations of blood and muscle lactate (musculus vastus lateralis) as well as plasma potassium increased more while muscle glycogen decreased more during electrically induced exercise. Hepatic glucose production always rose during exercise. However, during involuntary exercise with sensory blockade, it did not match the rise in peripheral glucose uptake and plasma glucose decreased (P < 0.05). Plasma glycerol increased less in electrically induced vs. voluntary exercise, and free fatty acids and beta-hydroxybutyrate decreased only during electrically induced exercise. Epinephrine, growth hormone, adrenocorticotropic hormone, and cortisol levels were higher during involuntary vs. voluntary exercise (P < 0.05). In conclusion, neural and humoral mechanisms exert redundant control with regard to responses of catecholamines and pituitary hormones (growth hormone and adrenocorticotropic hormone). In contrast, neural input from motor centers and feedback from working muscle are important for glucose production and lipolysis during exercise in humans. Humoral feedback is apparently not sufficient to trigger normal mobilization of extramuscular fuel stores.
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PMID:Hormonal and metabolic responses to electrically induced cycling during epidural anesthesia in humans. 880 25

We examined if patient-controlled analgesia (PCA) with i.v. morphine provided comparable postoperative analgesia after hysterectomy as extradural morphine, without increasing the incidence of side effects. The study (n = 40) was randomized and double-blind. An extradural catheter was inserted before surgery and anaesthesia was standardized. The extradural group received extradural morphine 0.06 mg kg-1 by the end of surgery and a second dose 6 h later. The i.v. group received an i.v. infusion of morphine 0.2 mg kg-1 after surgery. PCA with morphine 0.04 mg kg-1 i.v. was used in both groups. Pain relief (VAS), side effects and cognitive functions were evaluated for 18 h. Plasma samples were obtained for analysis of morphine concentrations. Mean consumption of PCA morphine was 2.4 mg h-1 for the i.v. group and 1 mg h-1 for the extradural group. Despite unlimited access to morphine, the i.v. group had higher VAS scores as the extradural group (P < 0.001). Plasma concentrations of morphine varied 8-10-fold in both groups. In the i.v. group itching, tiredness, blurred vision and vertigo correlated with cumulative consumption of i.v. morphine whereas in the extradural group this correlation existed only for tiredness. Both groups showed reduced ability to perform tests of cognitive function, indicating a central effect of both i.v. and extradural morphine, despite markedly lower plasma morphine concentrations in the extradural group.
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PMID:Extradural morphine gives better pain relief than patient-controlled i.v. morphine after hysterectomy. 905 97

The carpus and metacarpus of 40 horses which were free from lameness and 40 horses with lameness associated with the metacarpophalangeal joint or more distal limb were examined radiographically (Group A). The opacity of the proximal third of the third metacarpal bone was regular, with a uniform trabecular pattern. Osseous cyst-like lesions (OCLLs) were identified in the radial carpal bone (1), the ulnar carpal bone (2), the second carpal bone (15) and the fourth carpal bone (1). Thirty-one of 638 horses (4.8 percent) with forelimb lameness had pain localised to the proximal metacarpal region using local anaesthesia (Group B). All these horses were examined radiographically and an ultrasonographic examination was performed in seven. No definitive diagnosis was reached in 16 horses, seven of which had an OCLL in one of the carpal bones or the second metacarpal bone. One horse had, in addition to a poorly defined lucent area in the second carpal bone, radiographic evidence of degenerative joint disease of the carpometacarpal joint and an hypoechoic lesion in the accessory ligament of the deep digital flexor tendon. One horse had an hypoechoic lesion in the proximal part of the suspensory ligament. Abnormalities of the trabecular structure of the third metacarpal bone were identified in 13 horses. In 11 of these there was a vertically orientated lucent line, usually surrounded by sclerotic bone. These lucent lines may represent fatigue fractures seen end on. In one horse an horizontal lucent line was seen. One of these 13 horses also had a lesion in the proximal part of the suspensory ligament. Ten of the 13 (77 per cent) horses with presumed fractures of the third metacarpal bone recovered completely, whereas only eight of the 16 (50 per cent) horses in which no definitive diagnosis was reached returned to their former function.
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PMID:Some observations on lameness associated with pain in the proximal metacarpal region. 907 62

Between April 1994 and March 1996, 108 thyroidectomies (97 partial or unilateral lobectomies and 11 bilateral lobectomies) and 13 cervical explorations for hyperparathyroidism were performed under hypnosedation (HS) technique combining hypnosis and light conscious sedation. Informed consent was obtained from each patient. None of these patients underwent preoperatively standard susceptibility test score or preparatory hypnotic session. Nevertheless, no patient required conversion to general anesthesia. Operative data and postoperative courses were compared to a well-matched population (n = 70) of patients operated on for thyroid diseases under general anesthesia (GA). Under HS, mortality was zero and surgical management was only complicated by unilateral definitive recurrent laryngeal nerve paralysis in one case (0.8%) and the need for neck reexploration for severe hematoma after parathyroidectomy in another case. Hyperparathyroidism was cured in all cases. The surgeons all reported better operating conditions, estimated by visual analog scale (VAS), for cervicotomy using HS (8.9 +/- 0.6 cm vs 8.0 +/- 1.2 cm in the GA group, p < 0.01). This is probably related to reduced bleeding in the operative field. All the patients reported a very pleasant experience and enjoyed having their surgery performed under HS (VAS of satisfaction: 9.35 +/- 0.99 vs 2.88 cm +/- 2.8 cm in the GA group, p < 0.001). Patients having HS had less postoperative pain (VAS of pain: 2.2 +/- 1.6 cm vs 3.2 +/- 2.0 cm in the GA group, p < 0.01), whereas antalgic consumption was significantly reduced in the HS group compared with the GA group (paracetamol on first postoperative day was, 932 +/- 519 mg vs 1437 +/- 622 mg in the GA group, p < 0.001). Hospital stay was also significantly lower (46.3 h +/- 14.6 vs 74.2 +/- 9.5 h in the GA group, p < 0.001), providing a substantial reduction of the costs of medical care. The postoperative fatigue syndrome and surgical convalescence were significantly improved after HS (VAS of fatigue: 2.05 +/- 2.01 cm vs 4.7 +/- 2.4 cm in the GA group, p < 0.001, hand grip test: 95.5% of preoperative muscular maximum force vs 89.9% in the GA group, p < 0.01). Full return to social or professional activity was usually accomplished after 10.3 +/- 10.2 days in the HS group vs 36 +/- 8 days in the GA group, p < 0.001). From this study, we concluded that HS is a very effective technique for providing relief of intra- and postoperative pain in endocrine surgery. This technique results in high patient satisfaction and better surgical convalescence. This technique therefore can be used in most motivated patients and reduces the socio-economic impact of hospitalization.
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PMID:[Endocrine surgery by hypnosis. From fiction to daily clinical application...]. 908 97

In this double-blind placebo controlled study the preoperative cardiovascular and metabolic effects of intramuscular (i.m.) clonidine and midazolam are assessed. Forty-five ASA Grade I patients (n = 15 per group) undergoing plastic surgical procedures were randomly allocated to receive either placebo, clonidine 4 micrograms kg-1 or midazolam 70 micrograms kg-1. Drugs were administered into the deltoid muscle approximately 90 min prior to the scheduled induction of anaesthesia. The metabolic measurements were performed using an indirect calorimetry device. Heart rate and blood pressure were measured noninvasively. Pre-operative subjective anxiety, dryness of mouth and tiredness were assessed using visual analogue scales (VAS). Clonidine increased subjective tiredness significantly more than placebo. Clonidine also induced moderate decreases in blood pressure and heart rate. Oxygen consumption (VO2), CO2 production and energy expenditure (EE) decreased significantly after clonidine and midazolam. The decrease in VO2 and EE was maximally 11-14% on average from the base-lines after clonidine and midazolam. These effects were of longer duration after clonidine and lasted until the end of the 90 min study period. In conclusion, both clonidine and midazolam are effective as a means of decreasing pre-operative VO2 and EE.
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PMID:Cardiovascular and metabolic responses to clonidine and midazolam premedication. 908 19

This study of cat medial gastrocnemius (MG) muscle and motor unit (MU) properties tests the hypothesis that the normal ranges of MU contractile force, endurance, and speed are directly associated with the amount of neuromuscular activity normally experienced by each MU. We synchronously activated all MUs in the MG muscle with the same activity (20 Hz in a 50% duty cycle) and asked whether conversion of whole muscle contractile properties is associated with loss of the normal heterogeneity in MU properties. Chronically implanted cuff electrodes on the nerve to MG muscle were used for 24-h/day stimulation and for monitoring progressive changes in contractile force, endurance, and speed by periodic recording of maximal isometric twitch and tetanic contractions under halothane anesthesia. Chronic low-frequency stimulation slowed muscle contractions and made them weaker, and increased muscle endurance. The most rapid and least variable response to stimulation was a decline in force output of the muscle and constituent MUs. Fatigue resistance increased more slowly, whereas the increase in time to peak force varied most widely between animals and occurred with a longer time course than either force or endurance. Changes in contractile force, endurance, and speed of the whole MG muscle accurately reflected changes in the properties of the constituent MUs both in extent and time course. Normally there is a 100-fold range in tetanic force and a 10-fold range in fatigue indexes and twitch time to peak force. After chronic stimulation, the range in these properties was significantly reduced and, even in MU samples from single animals, the range was shown to correspond with the slow (type S) MUs of the normal MG. In no case was the range reduced to less than the type S range. The same results were obtained when the same chronic stimulation pattern of 20 Hz/50% duty cycle was imposed on paralyzed muscles after hemisection and unilateral deafferentation. The findings that the properties of MUs still varied within the normal range of type S MUs and were still heterogeneous despite a decline in the variance in any one property indicate that the neuromuscular activity can account only in part for the wide range of muscle properties. It is concluded that the normal range of properties within MU types reflects an intrinsic regulation of properties in the multinucleated muscle fibers.
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PMID:Fast-to-slow conversion following chronic low-frequency activation of medial gastrocnemius muscle in cats. I. Muscle and motor unit properties. 916 78

Patients reporting sensitivity to multiple chemicals at levels usually tolerated by the healthy population were administered standardized questionnaires to evaluate their symptoms and the exposures that aggravated these symptoms. Many patients were referred for medical tests. It is thought that patients with chemical sensitivity have organ abnormalities involving the liver, nervous system (brain, including limbic, peripheral, autonomic), immune system, and porphyrin metabolism, probably reflecting chemical injury to these systems. Laboratory results are not consistent with a psychologic origin of chemical sensitivity. Substantial overlap between chemical sensitivity, fibromyalgia, and chronic fatigue syndrome exists: the latter two conditions often involve chemical sensitivity and may even be the same disorder. Other disorders commonly seen in chemical sensitivity patients include headache (often migraine), chronic fatigue, musculoskeletal aching, chronic respiratory inflammation (rhinitis, sinusitis, laryngitis, asthma), attention deficit, and hyperactivity (affected younger children). Less common disorders include tremor, seizures, and mitral valve prolapse. Patients with these overlapping disorders should be evaluated for chemical sensitivity and excluded from control groups in future research. Agents whose exposures are associated with symptoms and suspected of causing onset of chemical sensitivity with chronic illness include gasoline, kerosene, natural gas, pesticides (especially chlordane and chlorpyrifos), solvents, new carpet and other renovation materials, adhesives/glues, fiberglass, carbonless copy paper, fabric softener, formaldehyde and glutaraldehyde, carpet shampoos (lauryl sulfate) and other cleaning agents, isocyanates, combustion products (poorly vented gas heaters, overheated batteries), and medications (dinitrochlorobenzene for warts, intranasally packed neosynephrine, prolonged antibiotics, and general anesthesia with petrochemicals). Multiple mechanisms of chemical injury that magnify response to exposures in chemically sensitive patients can include neurogenic inflammation (respiratory, gastrointestinal, genitourinary), kindling and time-dependent sensitization (neurologic), impaired porphyrin metabolism (multiple organs), and immune activation.
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PMID:Profile of patients with chemical injury and sensitivity. 916 75

HELLP syndrome in the parturient (hemolysis, elevated liver enzymes, and low platelet count) is associated with poor maternal and fetal outcomes. Maternal mortality has been estimated to be as high as 24%. Patients with HELLP syndrome are also at greater risk of pulmonary edema, adult respiratory distress syndrome, abruptio placentae, disseminated intravascular coagulation, ruptured liver hematomas, and acute renal failure. Perinatal mortality is equally high, ranging from 79 to 367 per 1,000 live births, and neonatal complications correlate with the severity of maternal disease. Many clinicians view HELLP syndrome as an entity of preeclampsia, and because of varied symptomatology, the initial diagnosis may be obscured. Prodromal signs include: (1) weakness and fatigue, (2) nausea and vomiting, (3) right upper quadrant and/or epigastric pain, (4) headache, (5) changes in vision, (6) increased tendency to bleed from minor trauma, (7) jaundice, (8) diarrhea, and (9) shoulder or neck pain. Before delivery, aggressive obstetric management is directed toward stabilization of the affected organ systems, if possible, and timely interruption of the pregnancy in the early phase of the accelerated disease progression. Definitive therapy is delivery. Parturients with HELLP syndrome are often critically ill; their infants are frequently premature and their conditions are compromised. Management criteria should include a multidisciplinary approach in a tertiary care center. Obstetric anesthesia personnel should perform a thorough preanesthetic evaluation and be familiar with the pathophysiologic changes of this syndrome. Determining the anesthetic of choice depends on the patient's condition, fetal well-being, and the urgency of the situation. In the presence of severe coagulopathy, regional anesthesia is contraindicated.
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PMID:HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets) pathophysiology and anesthetic considerations. 922 38


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