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At least 379 records · Page 21Linked to original sources
PubMed2004

[Are sleep difficulties in night work a problem for the offshore industry?].

BACKGROUND: Shift work is increasingly used in industry and services; in the Norwegian offshore industry approximately 6750 employees work night shifts. We wanted to look into the implications of night shifts on sleep and circadian rhythm, with particularly focus on the offshore sector. MATERIAL AND METHODS: We conducted literature searches on Medline, covering the period from 1966 to 2003; only eight studies pertaining to the offshore activity in the North Sea with emphasis on sleep and night work were identified. RESULTS: Night shifts on oil platforms were associated with sleeping difficulties. The isolated setting on the installations in the North Sea probably facilitates biological adaptation to night work compared to work onshore. Light therapy has a documented effect for re-adaptation to normal daytime functioning upon returning home. INTERPRETATION: Night work disturbs sleep. The level of functioning during the first night shifts is probably lower than the optimal level of functioning. Only a few studies of adaptation to night work in the offshore industry have been conducted and little research has been done concerning swing shifts in the North Sea. The field is obviously in need of more empirically based knowledge.

Adaptation, Physiological↗
PubMed2006

Interspecies differences of motor units properties in the medial gastrocnemius muscle of cat and rat.

The purpose of the study was to analyze the interspecies differences of motor unit contractile properties in two most frequently studied mammals: cats and rats. A total sample of 166 motor units (79 in cats and 85 in rats) was investigated in the medial gastrocnemius muscle. Considerable differences were found in composition of the studied muscle. In cats, fast fatigable, fast resistant and slow units formed 68, 18 and 14% of the investigated population, whereas in rats 36, 52 and 12%, respectively. The contraction and relaxation times of motor units in the cat muscle were evidently longer than in the rat and the border values for fast/slow motor units division in these species were 44 and 20 ms, respectively. The mean values of twitch and tetanic forces appeared to be 7-8 times lower in rats, for fast, while 2-5 times for slow motor units. Also variability between the strongest and the weakest units within each type revealed differences 10-60 times in cats, whereas only 3.5-14 times in rats. The summation of twitches into tetanus for fast units was comparable in both species, but for S units was evidently more effective in the cat. In fast motor units' tetanic contractions evident interspecies differences concerned sag appearance and profiles of unfused tetani of FF and FR units. Differences in contractile properties described in the study may depend on the size, number and innervation ratio of motor units in the muscle of cat and rat, as well as their biochemical variability. Differences in composition of motor unit types and uneven mechanisms of force development may reflect biological adaptation to variable behaviour of cats and rats.

Animals↗
PubMedDate not supplied

[The practice of intensive care medicine as a stress situation].

A study about the problem of stress in physician who work in intensive care units requires a previous reflection about the stress concept itself. Selye's conception undoubtedly signified a great progress for the comprehension of the processes of biological adaptation, but it seems it can not be easily applied to the psychological and social field. The decrease of psychosomatic diseases during the last world war is one of the many examples that make question the causal relationship between stress and disease. The concept of life event in anglo-saxon psychiatry is also discussed, as well as its attempt to measure the stressor character of these circumstances through a scale of points. The concept of "pathogenic situation" of German psychiatry is proposed in exchange. From this perspective, medicine in general and intensive medicine in particular can be seen as human activities constituting "pathogenic situations" for the ones who exercise them. The corresponding literature allows to establish that medicine generates more pathology in physicians than other professions, but intensive medicine does not seem to be more pathogenic than other specialties. The elements of the "medical act" which could be responsible for the stress or pathogenic situation are studied. Respecting intensive medicine, two are the characteristics which seem to contribute to make it "pathogenic" for those who exercise it: a mistaken vision of death as an "enemy" which has to be fought à outrance, and the "temporality of urgency", proper to an ICU, which makes that the doctor can not give himself time enough for listening to the patient and telling him the adequate word of consolation.

Adaptation, Psychological↗
PubMed1990

[Paradoxes of the treatment of cardiac insufficiency].

The explosion of new techniques and concepts arising from progress in molecular and cellular biology transformed our way of thinking about cardiac failure of mechanical origin in 1990. Cardiac failure indicates the limitations and imperfections of biological adaptation to a change in conditions of cardiac loading. Understanding this process of adaptation, understanding why cardiac hypertrophy of hypertensive origin remains compensated for such a long time, is and should be the basis of treatment. Inotropic therapy is paradoxically, fundamentally deleterious for the myocardial fibres, although, when considering the heart as a whole, reduction in chamber size is beneficial. Vasodilators and diuretics are not an alternative but a complement. Careful analysis of recently published clinical trials invalidates a dogmatic attitude in the debate of inotropic versus vasodilator therapy. Future developments should be based on a rational approach. The treatment of a disease of adaptation would seem to lie in the wide and virgin field of gene therapy or therapies modifying genetic expression or "drug design" based on the know structure of the hypertrophied myocyte.

Adaptation, Physiological↗
PubMed1986

Lactase deficiency and lactose malabsorption. A review.

The results of previous investigations of lactase deficiency and lactose malabsorption are reviewed. It showed that lactase activity and its decline in animals and humans is controlled genetically, but also that its phenotypic expression as lactose malabsorption is influenced by nongenetic factors: adaptation, biological (circadian) rhythmicity, hormones, gastrointestinal functions, and nutritional components can alter the response to lactose intake.

Biological Clocks↗
PubMed1988

[Characteristics of the mechanism of the development of the epidemic process in meningococcal infection in organized collectives].

The specific features of the epidemiology of meningococcal infection in organized groups have been established after comprehensive (epidemiological, microbiological and immunological) studies, evaluated from the viewpoint of the law of the autoregulation of the epidemic process. The studies have revealed the phenomenon of the adaptive biological variability of meningococci with their prolonged reservation due to the transformation of typical bacterial forms of meningococci characterized by strict serogroup specificity and typical fermentative activity into serologically and biochemically undifferentiated forms, capable of prolonged persistence in human populations. The model demonstrating the development of the epidemic process in meningococcal infection in an organized group has been worked out.

Carrier State↗
PubMed1978

Specific adaptation.

In this paper the key to the diagnosis, treatment and prophylaxis of chronic illnesses based on individual susceptibility to foods, drugs, food-drug combinations and environmental chemicals is discussed thoroughly.

Adaptation, Biological↗
PubMed1987

Reduced thermogenesis in muscle and disturbed lipoprotein metabolism in relation to thyroid function in haemodialysis patients.

Muscle thermogenesis, measured by direct calorimetry on resting biopsy samples, was studied in 28 haemodialysis patients and related to thyroid function variables, plasma lipoprotein concentrations and post-heparin lipase activities. The heat production was decreased in about 40% of the patients and significantly correlated with total thyroxine and free thyroxine index. In addition to a slight to moderate hypercholesterolaemia comparable to that found in subclinical hypothyroidism, the patients had also hypertriglyceridaemia in combination with low lipoprotein lipase activity and impaired fat tolerance. The latter abnormalities were related to the lowered muscle heat production values. The pattern of changes may represent a biological adaptation to the systemic illness for conservation of energy.

Adult↗
PubMed1986

Osteotomy of the patella.

Fifteen patients with patellofemoral pain resulting from patellar malalignment had coronal plane osteotomy of the patella. Patients were followed for an average of three years, and all results except one were favorable. The relief of pain was attributed to both the reduction of intraosseous pressure including associated biological adaptations and the mechanical realignment of the patella.

Adolescent↗
PubMed1985

[Ethnic variations of scalp hair].

There has been no polytypical variation in human hairforms for at least the last 10,000 years. In view of the wide variety of hair forms, it must be assumed that biological adaptation has occurred. Several features of the scalp hair, such as form, color, thickness, density, maximal length, tensile strength, etc. are clearly genetically determined. When dealing with diseases of the hair, it may be useful for the dermatologist to distinguish between "hair" and "hair".

Ethnicity↗