Search PubMed⌕ Search

Biomedical subjects

J F Fennis

Publications and source records attributed to J F Fennis.

51 records · Page 3Linked to original sources
PubMed1980

Reliability of the cardiac output measurement with the indirect Fick-principle for CO2 during exercise.

Cardiac output measurements were performed during 50 exercise tests in 16 normal subjects employing the indirect Fick principle for CO2. During sub-maximal steady state exercise the plateau CO2 tension (PplatCO2) was estimated with a rebreathing procedure. The mixed venous CO2 tension (PvCO2) was calculated by subtracting the alveolocapillary CO2 tension difference from the PplatCO2. Compared with data from the literature the most valid calculation of the cardiac output was obtained by using the PvCO2. Cardiac output values, calculated via the PplatCO2 turned out to be too low. The reproducibility was tested by repitition of 18 exercise tests at least after 5 days. The relative standard error of a single observation was 4.1% for the cardiac output, which was found to be as good as that of invasive measurements.

Adult↗
PubMed1979

Influence of selective and non-selective beta-adrenoreceptor blockade on the haemodynamic effect of adrenaline during combined antihypertensive drug therapy.

1. Haemodynamic effects of adrenaline were studied in 27 hypertensive patients, succesively during treatment with propranol and metoprolol. In 12 patients beta-adrenoreceptor blockade was combined with diuretics and in 15 patients the blockade was combined with vasodilators. 2. During propranolol adrenaline caused a marked pressor effect: there was a considerable rise in systolic as well as in diastolic blood pressure and a marked fall in heart rate. During metoprolol there was only a slight rise in blood pressure and an increase in heart rate. 3. Forearm blood flow was decreased by adrenaline during propranolol and was increased during metoprolol. Calculated vascular resistance showed opposite changes. 4. Results were essentially the same when beta-adrenoreceptor blockade was combined with diuretics or with vasodilators and did not differ from previous results obtained in patients treated by blockade alone. 5. If adrenaline infusion can be considered as a model for acute stress, our results seem to favour a selective beta 1-adrenoreceptor blocking agent over a non-selective one, even when the blocker is combined with a diuretic or a vasodilator.

Adult↗
PubMed1979

Effects of propranolol and metoprolol on haemodynamic and respiratory indices and on perceived exertion during exercise in hypertensive patients.

A double-blind cross-over trial of the non-selective beta-blocker propranolol and the beta1-selective blocker metoprolol was carried out in 8 hypertensive patients. At the end of each 4-week period of treatment haemodynamic and respiratory indices and perceived exertion were studied during moderate exercise. Both beta-blockers resulted in reduced heart rate, cardiac output, and blood pressure, whereas the stroke volume increased. Total peripheral resistance did not change. During exercise the expiratory peak flow rate equally increased in every period. However, the peak flow rate at rest, as well as during exercise, was reduced by propranolol, while metoprolol had no such influence. Neither of the beta-blockers changed O2 consumption, CO2 production, tidal volume, or respiratory rate. Moreover, they did not influence perceived exertion. These results suggest that the arteriolar and bronchiolar beta2-receptors do not play a major role in the alteration of circulation and ventilation during exercise. As far as their practical use as antihypertensive agents is concerned, this study shows no advantage in the use of either of these beta-blockers.

Adult↗
PubMed1977

[Gastro-intestinal bleeding and vascular calcification in pseudoxanthoma elasticum (author's transl)].

Pseudoxanthoma elasticum is an hereditary disease of elastic fibres affecting the skin, eyes and the cardio-vascular system. The radiologist should be familiar with this disease; the vascular changes can lead to bleeding from the gastrointestinal tract, which can be elucidated angiographically. There may also be circulatory disturbances in the extremities associated with early and pronounced calcification of the media and intima.

Angiography↗
PubMedDate not supplied

Physical activity in chronic fatigue syndrome: assessment and its role in fatigue.

This paper describes the assessment of physical activity in chronic fatigue syndrome (CFS) and investigated the following questions: Do patients with CFS have low levels of physical activity; is there a relationship between actual level of physical activity and fatigue; can self-report measures adequately assess actual level of physical activity; what is the role of cognitions with respect to physical activity; and are results with respect to physical activity specific to CFS? Three different types of activity measures were used: self-report questionnaires, a 12-day self-observation list, and a motion-sensing device (Actometer) which was used as a reference for actual activity level. Fifty-one patients with CFS, 50 fatigued patients with multiple sclerosis (MS), and 53 healthy subjects participated in this study. Although none of the self-report questionnaires showed high correlations with the Actometer, questionnaires that require simple ratings of specified activities were related to the Actometer and can be used as acceptable substitutes, in contrast to instruments that require general subjective interpretations of activity that had low or non-significant correlations with the Actometer. Actometer results showed that CFS patients and MS patients had similar activity levels and both groups were significantly less active than healthy subjects. Compared to MS patients, CFS patients were more likely to indicate that they had been less active than other persons they knew. Activities which patients expected to result in higher fatigue levels were less frequently performed. Patients with CFS had significantly higher scores on this measure than MS patients and healthy subjects. Low levels of physical activity were related to severe fatigue in CFS but not in MS. In conclusion, although CFS patients have similar low activity levels than MS patients, there are also important differences between both groups: in CFS cognitive factors are more prominently involved in producing the low activity levels than in MS and in CFS patients activity level is related to fatigue but not in MS.

Adult↗
PubMedDate not supplied

Cognitive-behavioral group therapy for irritable bowel syndrome: effects and long-term follow-up.

Little is known about the effectiveness of cognitive behavioral treatment for patients with irritable bowel syndrome on a group basis. Previous studies have used only small samples, and studies with long term follow-up are lacking. The arm of the present study was to investigate: a) the effectiveness of a cognitive-behavioral group treatment compared with a waiting list control condition in alleviating abdominal complaints and b) the long term effectiveness of cognitive-behavioral group treatment. In study 1, we performed a controlled study with 25 patients in the group treatment condition and 20 patients in the waiting list control condition. Treatment consisted of eight 2-hour group sessions over a period of 3 months. In study 2, all patients were treated and followed up for an average of 2.25 years (range 6 months-4 years) after the completion of the group treatment. The abdominal complaints of the patients who underwent treatment were found to improve significantly more than the complaints of the patients awaiting treatment. Moreover, in agreement with the purpose of the therapy, the number of successful coping strategies was found to increase more and patients' avoidance behavior was found to decrease more in the treatment group than in the waiting list control group. The positive changes appeared to persist during follow-up. Cognitive-behavioral group treatment is effective in alleviating irritable bowel syndrome, in stimulating coping strategies, and in reducing avoidance behavior. At long term follow-up, the abdominal complaints, the number of successful coping strategies, and the avoidance behavior were still improved compared with the pretreatment assessment.

Abdominal Pain↗