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Biomedical subjects

M Ahrens

Publications and source records attributed to M Ahrens.

29 records · Page 2Linked to original sources
PubMed1978

[The effect of an on the job training program -- stairclimbing -- on the physical working capacity of employees (author's transl)].

Following medical screening and physical fitness testing (W170) 52 voltuntary employees in a 31-story administration building were formed into matched pairs and randomly allocated into intervention (stairclimbing) and control (lift) groups. The intervention group was asked to climb at least 25 floors/workday or 125 floors/week. the control group was asked to use only the lift. The intervention time was 10 weeks. The physiological measurements were made before and after the intervention. The number of stairs climbed was recorded daily in a diary. The heart rate was recorded continuously over one workday before and during the interventions. The average quantity of training in the final intervention group (n = 19) was 29.9 floors/workday or 36,790 kpm/week and in the control group 4.6 and 5980 correspondingly. The average training frequency was 4.3 in intervention and 1.4 climbs/workday in the control group. The average number of continuous floors used during climbing was 7.0 in intervention and 3.4 in control group. The average number of minutes on heart rate level of 130-159 beats/min during one workday was 7.8 in intervention and 1.6 in control group. The W170 (W/kg) increased 17.8% and the predicted VO2max (ml/min/kg) 15.1% in intervention group. The difference between the intervention group and the control group was significant (p less than 0.01). It was concluded, that stairclimbing is a suitable on the job physical activity program for middle-aged, untrained men.

Employment↗
PubMed1978

Some observations on ocular manifestation of sickle cell disease.

The ocular manifestations of 76 sickle cell disease patients are reported. Our findings indicate that any type of sickle cell oculopathy may appear in conjunction with any type of hemoglobinopathy and that no single ocular finding is specific to any one type of sickle cell anomaly. Sickle cell oculopathy, particularly retinopathy, is found to be a slowly progressive condition. Treatment of retinal and vitreal neovascularization with photocoagulation seems to be indicated to stop the disease process. Acute retinal vascular occlusion seems to respond favorably to the intravenous administration of low molecular weight dextran and papaverine hydrochloride. Sickle cell patients suffering from retinal detachment do not respond favorably to conventional retinal detachment surgery.

Adult↗
PubMed1977

Effect of heparin modification on its activity in enhancing the inhibition of thrombin by antithrombin III.

Studies were conducted to determine the effect of modifying specific functional groups of heparin on its antithrombin III-enhancing activity. The derivatives employed were heparin methyl ester, heparinylglycine and N-desulfated heparin. The carboxyl-modified derivatives increase the rate of inhibition of thrombin by antithrombin III, although not to the same extent as heparin. N-Desulfated heparin is devoid of any activity. Heparin methyl ester is more potent than heparinylglycine in activating antithrombin III, as exhibited by its immediate effect on the thrombin-fibrinogen reaction. However, heparinylglycine is the more effective of the two, in increasing the rate of thrombin deactivation by antithrombin III. The results indicate that although free carboxyl groups of heparin are not crucial for its binding to antithrombin III, they are important for the combination of the latter with thromobin. In contrast, N-sulfates are critical for the interaction of heparin with antithrombin III.

Animals↗
PubMed1977

[Studies on the success of insemination after various insemination dates in biotechnical puberty induction of young sows].

Different frequencies and periods of insemination were checked with the view to optimising puberty induction to young sows, for which purpose 500 IU PMS/250 IU HCG were injected to 571 animals in seven experiments. Insemination was carried out by deadline, since follicle stimulation was exhibited by almost all animals following the above treatment, while only some of them displayed tolerance. Advantage was taken of the induced oestrus, since its ovulation rates were higher than those associated with subsequent heat cycles, and because a synchronised second oestrus was recordable only from some of those animals which exhibited follicle stimulation in response to puberty induction. The most favourable results in terms of pregnancy and number of embryoes, against the background of the great variability in ovulation onset, were obtained, if insemination was applied 72, 96, and 120 hours after gonadotrophin treatment. From among the variants with two inseminations, good results were obtained from those 96 and 120 hours after PMS/HCG treatment.

Animals↗
PubMed1977

[Studies on various dosages of PMS and HCG in biotechnical puberty induction in young sows].

The PMS and HCG doses by which to induce puberty and successfully use the first induced oestrus were tested in three experimental slaughter series on 197 prepuberal young sows. An injection of 500 International Units of PMS and 250 IU of HCG was found to bear greatest promise. While higher dosages gave higher rates of ovulation and, following insemination, higher numbers of embryos, pregnancy rates as a whole dropped severely. Since a very high percentage of all animals involved exhibited follicle stimulation, following such treatment, while only half of them displayed tolerance, it is strongly suggested to use for all animals deadline-oriented rather than toleranceoriented insemination.

Animals↗
PubMed1977

[The course of ovulation after biotechnical puberty induction in young sows].

Four experimental series were applied to 342 prepuberal young sows to establish ovulation developments. Different periods of time were allowed to elapse between injection and slaughter. Injected were 400 IU PMS/200 IU HCG or 500 IU PMS/250 IU HCG. Onsets of ovulation were found to be highly differentiated and variable. Some of the animals had completed ovulation 72 hours after application of gonadotrophin, whereas in others had not even started 168 hours after such application. In the majority of all sows involved in the experiments ovulation occurred 96--144 hours from application of the gonadotrophis hormone. In other words, fertile semen should be present in the genital tract of sows in that period of time, if the concept of deadlineoriented insemination is followed.

Animals↗
PubMed1976

Free serum histidine levels in patients with rheumatoid arthritis and control subjects following an oral load of free L-histidine.

A dose of 3.7 g of free-L-histidine was administered by mouth to 26 patients with active rheumatoid arthritis and to 29 control subjects. The patients with rheumatoid arthritis had a statistically significant (p=10(-12)) lower pretreatment concentration of free histidine in serum (1.20 mg/100 ml, SE=0.04) than the control subjects (1.90 mg/100 ml, SE=0.06). However, there were no statistically significant differences between rheumatoid and control subjects with respect to the serum histidine concentrations 1 hr, 3 hr, and 4 hr after the ingestion of L-histidine. The changes in the serum histidine concentrations at 1 hr, 3 hr, and 4 hr (compared to the pretest values) were also not significantly different in the patients with rheumatoid arthritis relative to the control subjects. This study suggests that the subnormal free serum histidine concentration of rheumatoid arthritis is not associated with abnormal serum levels of free histidine following an oral load of free histidine.

Administration, Oral↗
PubMed1976

Trabeculectomy in a Black American glaucoma population.

Trabeculectomy was performed on 51 Black patients with uncontrolled glaucoma. The operation was successful in 80 per cent of cases followed-up for an average of 18 months. Success seemed to be independent of whether the superficial scleral flap was or was not sutured, although subconjunctival drainage, as indicated by the appearance of a bleb, seemed to be the predominant mechanism whereby the procedure functioned. The success rate in this series is the highest reported for glaucoma filtering procedures in Black glaucoma populations. Trabeculectomy may now be the operation of choice in uncontrolled glaucoma occurring in Black patients.

Adult↗
PubMed1976

[Attempted suicide in Lübeck 1947-1968, data and tendencies (author's transl)].

Evaluation of 2937 case notes of patients admitted for attempted suicide to the department in Lübeck between 1947 and 1968. This series can be seen as resentative for the Lübeck region. During this period the number of cases has increased about fourfold and has been rising since. Mortality could be reduced to 3% or below. Earlier typical differences between the sexes have since approached each other so that in the end men and women showed the same increase by age during the third decennium. Women were admitted significantly more frequently than men. Drugs, particularly sleeping pills and transquilizers, have greatly increased in suicide attempta. Earlier attempts occurred in 30% of cases. Measured by additional diagnoses, the morbidity of the series lay be 44.8%.

Adolescent↗