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Biomedical subjects

B Griefahn

Publications and source records attributed to B Griefahn.

At least 37 records · Page 2Linked to original sources
PubMed1995

Maximal physical work performance with European standard based fire-protective clothing system and equipment in relation to individual characteristics.

Every fire fighter needs to wear fire-protective clothing and a self-contained breathing apparatus (SCBA) several times a year while carrying out various fire-fighting and rescue operations in hazardous work environments. The aim of the present study was to quantify the effects of a multilayer turnout suit designed to fulfil European standard EN 469 used over standardized (Nordic) clothing and with SCBA (total mass 25.9 kg) on maximal physical work performance, and to evaluate the relationship between individual characteristics and power output with the fire-protective clothing system and SCBA. The subjects were 12 healthy firemen aged 26-46 years. The range of their body mass, body fat and maximal oxygen consumption was 69-101 kg, 10-20% and 2.70-5.86 l.min-1, respectively. The maximal tests without (control) and with the fire-protective clothing system and SCBA were carried out on a treadmill in a thermoneutral environment. When compared to the control test, the decrease in the maximal power output in terms of maximal working time and walking speed averaged 25% (P < 0.001) varying from 18% to 34% with the fire-protective clothing system and SCBA. At maximum, no significant differences were found in pulmonary ventilation, absolute oxygen consumption, the respiratory exchange ratio, heart rate, systolic blood pressure, the rate-pressure product, mechanical efficiency, and the rating of perceived exertion between the tests with and without the fire-protective clothing system and SCBA. The reduction of the power output was related to the extra mass of the fire protective clothing and SCBA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Serum prolactin concentration and hypothalamic-pituitary hormone release in CF-children.

Some experimental data from animals suggest that prolactin (PROL) is involved in sweat production and modulates the chloride concentration of sweat. We determined the serum PROL level by RIA in 38 CF-patients (age: 3-24 years) and 48 patients with bronchial asthma (age: 2-18 years) and found no concentration differences between the two groups each taken as a whole; the TSH level was increased in CF (p less than 0.05). Separate analysis showed a significantly higher PROL level in CF-females and in CF-children (male and female) under 12 years old (p less than 0.05). To assess the hypothalamic-pituitary system we performed the metoclopramide test (by Cerucal) on 30 children suffering from CF (n = 10), bronchial asthma (n = 10) or pyelonephritis (n = 10) for PROL, LH, FSH, TSH and HGH. The hormone release was normal for all kinds checked in all groups of patients. Hence it follows that the neurohormonal system of prolactin is normal in CF-patients and the increased serum PROL and TSH concentrations in CF should be seen as a regulatory phenomenon but not as a mechanism associated with the basic defect of the CF-disease.

Adolescent↗
PubMed1988

[Social medicine in the curriculum of universities of West Germany. Recommendations for developing topics and organization].

At German universities and colleges social and community medicine is mainly taught by lecturers from various medical fields. Accordingly a great variety of topics are presented and different focuses are set. Thus orientation becomes more difficult for the students. The present paper was elaborated by experienced lecturers. It contains proposals for the organization of the lessons. With regard to the topics a list of priorities is presented and criteria for the qualification of the lecturers are formulated.

Curriculum↗
PubMed1986

A critical load for nocturnal high-density road traffic noise.

Eighteen female and 18 male students (21-30 years) slept in the lab during 12 consecutive nights each, where a high-density road traffic noise was played back with four intensities. EEG and EOG were recorded continuously throughout the nights. In the morning the subjects assessed their sleep and completed a reaction time test. The following conclusions were made: Performance was not affected by noise. REM sleep decreased abruptly as soon as the sound pressure level exceeded 44 dBA. With increasing noise, sleep was assessed as increasingly worse. Noise-induced sleep disturbances were not related to sex. The equivalent sound pressure level measured for high-density road traffic seems to be a valuable predictor for subjective sleep disturbances as long as the maximum levels do not exceed it by more than 8-10 dBA. On the basis of the assessment of sleep and supported by the abrupt decrease of REM sleep, an equivalent noise level of 40 dBA indoors was defined as a critical load, above which nocturnal noise cannot be tolerated any longer.

Adult↗
PubMed1985

[The effect of acetylsalicylic acid on the transmural potential difference of gastric mucosa of infants, adolescents and adults].

The transmural electric potential difference (PD) of the gastric mucosa was investigated in children, teen-agers, and adults. Acetylsalicylic acid, a well known barrier breaker, causes in adults a characteristic decrease of the gastric PD. This effect in teen-agers is considerably weaker than in adults, while in children there is no significant decrease of the potential difference after local acetylsalicylic acid application.

Adolescent↗
PubMed1980

[Pathogenic significance of the elongated basilaris artery].

The following phenomena are discussed as pathogenetic sequelae of an elongated and deformed A. basilaris: 1. Mechanical cerebral nerve disorders and complex infratentorial vascular syndromes. 2. Impressions of the bottom of the third ventricle by the terminal basilar or stenosing of the aquaeduct by its backward angulation. 3. Induction of an active hydrocephalus. 4. Displacement of the elongated basilar by an anterior herniation in the tentorial slot. 5. Complex conditions of a hydrocephalus development from an elevation of the a. basilaris, disorders of the dynamics of the spinal fluid and a relative stenosis of the aquaeductus. The term megadolichobasilar is reserved for the arteriosclerotically elongated and deformed basilar. One should speak of a basilar deformation in case of a distinct elevation of the terminal basilar artery in relation to the dorsum sellae level without a vascular deformation.

Adult↗
PubMed1978

EEG-responses caused by environmental noise during sleep their relationships to exogenic and endogenic influences.

At a certain level of intensity acoustical stimuli occurring during the night lead to sleep disorders. Whereas presumed after-effects (decrease of performance, functional and organic diseases) can as yet not be related to noise, it is evident that the primary effects which can be recorded immediately after stimulus onset are caused by noise. Because of the small number of experimental trials carried out in different investigations, the results of each single paper can only be tentative. Therefore--concerning awakening reactions and less than a change of at least one sleep stage--the data from publications of comparable method and evaluation have been summarised. With these data all calculations have been repeated. The results and influence of several exogenic and endogenic factos are demonstrated. Becuase of the different methods used only 10 out of 60 publications have been used. In spite of this restriction of data, at least as far as trends are concerned, they appear to be consistent; numerical results should at this stage only be regarded as tentative.

Electroencephalography↗
PubMed1977

[Evaluation of changes in pulse rate caused by stimuli (author's transl)].

Short acoustical stimuli induce a biphasic reaction in pulse rate. After an initial increase in frequency, pulse rate decreases below the value calculated before stimulation. This decrease is followed by a slow increase towards the baseline value. As described by other authors the maximum occurs at the 4th heart beat after onset of stimuli. It could be pointed out that the occurrence of the maximum is related to the pulse rate measured before the stimuli. The higher this rate, the "later" the maximum occurs if it is expressed in beats after stimulation. A new mode of evaluation which is independent of pulse rate pointed out that the time between stimulus and maximum is constant. It is proposed to use the evaluation described here in order to allow a most exact location of the extreme values. For experiments with very small variability of pulse rate the evaluation used till now will be sufficient, but only if the mean pulse rate and it's standard deviation before stimulation is mentioned.

Acoustic Stimulation↗