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

1. Electrophysiological techniques have been employed to examine the nature of the response observed in the ectodermal slow-conduction system (SSI) when dissolved food substances contact the column of Tealia felina. The response seems to consist entirely of sensory activity which may continue for periods of many minutes, provided that the stimulatory chemicals remain contacting the column. 2. The interval between each evoked pulse gradually increases as the sensory response progresses. This does not result from fatigue in the conduction system but involves a genuine process of sensory adaptation. This may occur over a period of several minutes, which is much longer than comparable adaptation in higher animals. 3. Physiological evidence suggests that the chemoreceptors involved are dispersed throughout the column ectoderm and are absent from the pedal disc, oral disc, tentacles and pharynx. 4. The basic role of the SSI in coordinating behavioural activity in sea anemones is reviewed. It is concluded that it functions primarily as a single, diffuse-conducting unit responsible for transmitting frequency-coded sensory information from ectodermal chemoreceptors to ectodermal (and perhaps endodermal) effectors.
 ...
PMID:An electrophysiological analysis of chemoreception in the sea anemone Tealia felina. 0 Apr 49

1. The SS 1 fatigues in response to repetitive electrical stimulation. This fatigue is manifested by an increased conduction delay and a decreased SS 1 pulse amplitude. 2. Continued repetitive stimulation leads to the failure of the system. Recovery may take many seconds. Narrow strips of column fail more rapidly than wide strips. 3. The increased conduction delay is explained in terms of a decrease in the population of spiking cells. 4. A computer model is described and analysed. It suggests that conduction between electrically coupled ectoderm cells could be the basis for the SS1. The SS 1 may have properties not so far experimentally demonstrated; for example, under certain conditions it could behave as a local system.
 ...
PMID:The transmission of impulses in the ectodermal slow conduction system of the sea anemone Calliactis parasitica (Couch). 0 57

Stripped duodenal mucosa of rabbits was mounted in Ussing chambers containing a Ringer solution gassed with 100% O2. The disappearance of acid or alkali from the mucosal solution of short-circuited tissue was measured with a pH stat while the serosal pH was kept at 7.4. The duodenum rapidly disposed of both acid and alkali; neither property was altered by gassing with N2 while iodoacetate was in the perfusing solutions. Prevention of release of CO2 from the mucosal chamber obliterated the early rapid phase of acid disposal by the mucosa while a similar maneuver in the serosal chamber increased the appearance of serosal acid without altering the rate of acid disposal. Gut sacs of rabbit duodenum in vitro and in vivo showed a positive correlation between acid disposal and the rate of luminal CO2 production. While acid disposal progressively decreased with time for the in vitro gut sacs, the in vivo gut sac showed no fatigue in this respect. Luminal acidification in the Ussing chamber was associated with a profound reduction in short-circuit current (Isc), partially reversible by elevation of the mucosal pH but not by luminal glucose. Our data suggest that acid disposal occurs in part by intraluminal neutralization and in part by diffusion into the mucosa.
 ...
PMID:Mechanisms of disposal of acid and alkali in rabbit duodenum. 0 19

A multiplicative and additive formula has been developed for assisting in the development of schedules for airline pilots and flight engineers. The formula is based on freshness/tiredness data derived from aircrews on world flights. It should materially assist those who develop the schedules to avoid, where possible, finalizing those crew patterns that would impose a severe physiologic load on cockpit personnel. The objective of the application of the formula is to assure that crew members retain adequate "physiologic reserve" in the course of flying various segments of a pattern. This enables them to absorb the stresses of schedule delays or disruptions, as well as unforeseen operational problems and flight emergencies.
 ...
PMID:Physiological index as an aid in developing airline pilot scheduling patterns. 0 54

Muscle biopsies taken from the musculus quadriceps femoris of man were analysed for pH, ATP, ADP, AMP, creatine phosphate, creatine, lactate and pyruvate. Biopsies were taken at rest, after circulatory occlusion and after isometric contraction. Muscle pH decreased from 7.09 at rest to 6.56 after isometric exercise to fatigue. Decrease in muscle pH was linearly related to accumulation of lactate plus pyruvate. An increase of 22mumol of lactate plus pyruvate per g of muscle resulted in a fall of 0.5pH unit. The apparent equilibrium constant of the creatine kinase reaction (apparent K(CK)) increased after isometric contraction and a linear relationship between log(apparent K(CK)) and muscle pH was obtained. The low content of creatine phosphate in muscle after contraction as analysed from needle-biopsy samples is believed to be a consequence of an altered equilibrium state of the creatine kinase reaction. This in turn is attributed mainly to a change in intracellular pH.
 ...
PMID:Creatine kinase equilibrium and lactate content compared with muscle pH in tissue samples obtained after isometric exercise. 0 60

A blood uric acid analysis has been effected on 193 Iranians of the intellectual group aged from 25 to 60, of which the normal average rate for 99 women and 94 men of a normal state are (47.5 +/- 2.73) and (53.62 +/- 2.73) respectively. After having controlled the uricemia of these subjects during a period of three years in the three states of healthiness, fatigue or physical strains and sickness, we have been able to note that during physical fatigue and intellectual strains the uricemia presents an augmentation notable as in the case of the sicknesses. Taking into consideration the hyperuricemia resulting from fatigue and strains, it may be noteworthy to be taken into consideration by the clinical laboratories and the physicians as well.
 ...
PMID:[Physical and mental fatigue of probable hyperuricemia origin]. 0 23

It appears that green absorptive lenses are highly desirable for the purposes of shielding the eyes against light radiation from molten metal during the casting and soldering procedures. The dental laboratory technicians have experienced no after-images, less eye fatigue, and no adverse symptoms when using these lenses, as were reported previously. The lenses not only effectively protect the eyes from the injurious light wavelengths, but they also provide for enough normal (as well as individually corrected) vision to accomplish any procedure necessary in the dental laboratory. We propose that the green absorptive lenses, with individual corrections if needed, be considered for dental laboratory technicians during dental laboratory procedures when needed, such as during casting and soldering, to protect their eyes from light radiation.
 ...
PMID:Eye protection from light radiation. 0 39

The composition and structure were studied in the cast and in the solder of bridges which had failed clinically. Both materials were gold alloys but with different contents of Pt, Ag and Zn. The metallographic investigation revealed defects mostly in the solder, situated in the subsurface layer. SEM studied of the fracture surface revealed large porosites and a structure of dense parallel lines--striations--, indicating that the material had failed from fatigue. The materials in the fractured bridges were identified by micro-probe measurements. It was stated that cast material and solder material used together, were of different composition.
 ...
PMID:Microstructure of the solder-casting zone in bridges of dental gold alloys. 1 May 39

In the light of three case histories, other personal observations and the literature, the clinical and electroencephalographical differences between absences in the limited sense and continuous LENNOX petit-mal state are described and the problems of the latter discussed. As a rule, petit-mal state is diagnosed as such in young people or adults, and practically never before the 10th year of life. In about two thirds of cases, its clinical symptomatology consists of a twilight condition lasting some hours to a few days, coupled with inertia and apathy. The remaining third of the patients usually experience milder disturbances, e.g. in the form of concentration difficulties, tiredness, and (more rarely) severe forms including lethargy. The EEG correlate of a petit-mal state is made up of continuous bilaterally synchronous, frontally marked (less frequently with exclusively frontal localization), usually irregular spike waves or poly-spike waves, which frequently occur in only rudimentary forms and register a frequency of 2 1/2-4 c/sec. For the treatment of petit-mal state, benzodiazepines and in particular clonazepam (Rivotril) (1-2 mg i.v.) are recommended. During the interval condition the same therapy as with an absence epilepsy, e.g. succinimides or dipropylacetate (Depakine) is administered. Anti-grand-mal remedies, especially hydantoins, may trigger petit-mal status.
 ...
PMID:[The petit-mal-status]. 1 55

The purposes of this study were: (1) to test the usefulness of intensive design in detecting the effects of an established antianxiety agent in a single patient studied for a period as brief as 8 weeks and (2) to explore the usefulness of combining intensive and extensive designs by jointly analyzing the results from several similarly treated patients. Fifteen primarily anxious, psychoneurotic patients aged 21-50 and scoring 17 or more on the Taylor Manifest Anxiety Scale were admitted to the study; and 11 completed the full treatment program. Medications were diazepam 5 mg t.i.d. and a matching placebo, administered under double-blind conditions. Patients were treated for 8 weeks, divided into 42-week blocks. In each block, the patient received diazepam 1 week and placebo the other, with the order in each block determined at random. The patient came weekly for evaluation, including, self-ratings on the Hopkins Symptom Checklist (SCL), global status, global change; reports of occupational and social function; resting pulse; reaction time; psychiatrist's ratings on the Hamilton Anxiety Scale, global status and global change. The patient also reported daily his mood on the Profile of Mood States (POMS). Mean deviations from the general trend for post-diazepam and postplacebo scores on each criterion were compared within patients. Diazepam-placebo differences on each criterion were analyzed between patients. Criteria that clearly recorded the anti-anxiety effect of diazepam as compared to placebo included the Hamilton Anxiety Scale, the psychiatrist's global status and global change ratings, the SCL Anxiety and Somatization Scales, and the POMS Anxiety Scale. Other criteria that showed a reliable diazepam effect included SCL Depression (decrease), POMS Vigor (increase), POMS Fatigue (decrease), SCL Anger (increase), and reaction time (increase). The most sensitive criteria distinguished diazepam from placebo even when results were considered only from the first 6 patients during their first 4 weeks of treatment- a total of 24 patient weeks of treatment. The factors contributing to the sensitivity of this design were investigated and discussed.
 ...
PMID:Intensive design in evaluating anxiolytic agents. 1 97


1 2 3 4 5 6 7 8 9 10 Next >>