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U Marx

Publications and source records attributed to U Marx.

27 records · Page 2Linked to original sources

Application of a hollow fiber membrane cell culture system in medicine.

The Tecnomouse system is useful for cultivating transformed cell lines producing MAbs or recombinant proteins, but human tumor cells can also be propagated for autologous immunization protocols or research properties. Lymphokine-activated killer cell production and stem cell proliferation seem to be possible. Moreover, primary human cells of lymphoid organs can be successfully kept viable over long periods of time in a three-dimensional, tissue-like culture. Therefore, the bioreactor is a tool for the in vitro modulation of a variety of human organs.

Animals↗

[Long-term registration of arterial blood pressure in sleep with noninvasive methods].

Sleep related breathing disorders and essential hypertension are highly interrelated. Many different studies proved a casual relationship between the two disorders (1,2). In a clinical sleep laboratory diagnostics of hypertension has to be non-invasive. There are two completely different methodologies to record blood pressure noninvasively. Continuous methods using fingerphotoplethysmography can record apnea related cyclical variations of blood pressure beat to beat. Unfortunately the absolute value of the pressure readings is sensitive to the position of the finger sensor. Noncontinuous methods using arm cuff inflation preserve appropriate blood pressure values but these are only spot measures during the night. To make use of these it is necessary to record other sleep and respiration related signals in parallel. Both methods were applied in our sleep laboratory and results are presented.

Blood Pressure↗

Influence of metoprolol and cilazapril on blood pressure and on sleep apnea activity.

Up to 50% of hypertensive men are subject to sleep apnea (SA). With a prevalence in men of up to 10%, SA is a common illness and hypertension (HT) one of its early symptoms. It is important to have available a drug treatment that will effectively control blood pressure (BP) without exacerbating symptoms of SA. Twelve patients with SA and HT were investigated in a double-blind, comparative trial. Patients were randomly allocated to either metoprolol (M) 100 mg daily or cilazapril (C) 2.5 mg daily. Polysomnographic measurements under standardized conditions including intraarterial BP monitoring were taken on two consecutive nights each before and after the 1-week treatment. Values in the M group were (mean +/- 95% CI) systolic BP 161 +/- 2.1 vs. 148 +/- 2.2 mm Hg (p less than 0.01); diastolic BP 98 +/- 1.8 vs. 93 +/- 1.8 mm Hg (p less than 0.01); and HR 73 +/- 1.2 vs 65 +/- 1.1 beats/min (p less than 0.01). Corresponding figures for the C group were systolic BP 140 +/- 2.1 vs. 127 +/- 2.1 mm Hg (p less than 0.01); diastolic BP 95 +/- 1.7 vs. 78 +/- 1.7 mm Hg (p less than 0.01); and HR 82 +/- 1.1 vs. 79 +/- 1.2 beats/min (p less than 0.01). Whereas C reduced both BP and HR in all sleep phases, M produced no changes during REM sleep. SA activity was 45 (range 15-91) vs. 34 (range 2-57) apneas per hour of sleep in the M group and 54 (range 21-84) vs. 40 (range 8-72) apneas per hour in the C group (p less than 0.01). There were no changes in total sleep time or in the proportions of non-REM to REM sleep. Both M and C reduce nocturnal BP in SA patients, but the effect of C is seen in all sleep phases. C has a more favorable effect on the disturbed nocturnal blood pressure of SA patients.

Adult↗

Oxygen consumption and metabolic strain in rowing ergometer exercise.

Oxygen consumption (VO2) when rowing was determined on a mechanically braked rowing ergometer (RE) with an electronic measuring device. VO2 was measured by an open spirometric system. The pneumotachograph valve was fixed to the sliding seat, thus reducing movement artefacts. A multi-stage test was performed, beginning with a work load of 150 W and increasing by 50 W every 2 minutes up to exhaustion. Serum lactate concentrations were determined in a 30 s break between the work stages. 61 examinations of oarsmen performing at maximum power of 5 W X kg-1 or more were analysed VO2 and heart rate (HR) for each working stage were measured and the regression line of VO2 on the work load (P) and an estimation error (Sxy) were calculated: VO2 = 12.5 X P + 415.2 (ml X min-1) (Sxy = +/- 337 ml, r = 0.98) Good reproducibility was found in repeated examinations. Similar spiroergometry was carried out on a bicycle ergometer (BE) with 10 well trained rowers and 6 trained cyclists. VO2 of rowing was about 600 ml X min-1 higher than for bicycling in the submaximal stages for both groups. The VO2max of RE exercise was 2.6% higher than for oarsmen on BE, and the cyclists reached a greater VO2 on BE than the oarsmen. No differences were found between RE and BE exercise heart rate. The net work efficiency when rowing was 19% for both groups, experienced and inexperienced: when cycling it was 25% for cyclists and 23% for oarsmen.

Energy Metabolism↗

Reversal of multidrug resistance by amitriptyline in vitro.

Amitriptyline, a tricyclic antidepressant, was able to reverse the multidrug resistance efflux pump of human colon cancer subline SW 620 and multidrug resistant (mdr) mouse lymphoma cells by decreasing rhodamine 123 efflux. The inhibitory effect of amitriptyline on the efflux pump was dose dependent. An investigation was made of the effects of mouse tumour necrosis factor (TNF) alpha and interferon (IFN) gamma on the efflux pump activity of mdr cells together with amitriptyline compared to the par cells (mdr-). After long-term cytokine pretreatment of mdr cells, the amitriptyline was more effective, due to some synergism between the amitriptyline and TNF-alpha.

ATP Binding Cassette Transporter, Subfamily B, Mem↗