Biomedical subjects

H M Häfner

Publications and source records attributed to H M Häfner.

9 recordsLinked to original sources

PubMed2003

Systemic scleroderma patients have improved skin perfusion after the transdermal application of PGE1 ethyl ester.

BACKGROUND: Patients with systemic scleroderma exhibit a noticeable slowing of blood cell velocities or even stasis in the capillaries of the skin. In this study the effects of transdermally applied prostaglandin PGE1 ethyl ester on nutritive cutaneous perfusion and on Raynaud's symptoms were investigated. PATIENTS AND METHODS: 24 patients with systemic scleroderma were treated transdermally over a period of 14 days with prostaglandin E1 ethyl ester patches. The response of blood cell velocity in the nailfold capillaries to cold exposure was tested in 20 patients, and all of the patients recorded the number of Raynaud's episodes in a journal over a period of two weeks. RESULTS: After the transdermal application of prostaglandin E1 ethyl ester there was an increase in blood cell velocity in the nutritive capillaries of systemic scleroderma patients (increase from 0.35 +/- 0.14 mm/s to 0.47 +/- 0.11 mm/s, (p < 0.05)). At the same time there was a decrease in the number of Raynaud's episodes (2.9 +/- 2.4 per day to 2.6 +/- 2.0 per day (p < 0.05)). CONCLUSION: The transdermal application of prostaglandin E1 ethyl ester was shown to have a favourable effect on nutritive blood flow in the capillaries of the skin in systemic scleroderma patients.

Administration, Cutaneous↗

PubMed2003

Interface pressure under a ready made compression stocking developed for the treatment of venous ulcers over a period of six weeks.

BACKGROUND: The most important component in the treatment of venous ulcers is compression therapy. The function of compression therapy is the pressure exterted on the extrafascial and intrafascial venous system. Therefore the interface pressure of specially designed compressions stockings for the treatment of venous ulcers are in the focus of interest. PATIENTS AND METHODS: We examined 20 patients (6 men and 14 women) with chronic venous insufficiency in CEAP stages CS0-4EPAS1-3PR). Interface pressure was measured under the Venotrain Ulcertec over an observation period of six weeks with piezoresistance sensors at four different sites on the lower leg and with the patient in different body positions. RESULTS: Resting pressure supine at the ankle corresponded to compression class III and was constant over the period of six weeks (mean difference 2.8 SD 15.3 mmHg, p = 0.49). Working pressure explained as the quotient of maximum pressure during tiptoing/resting pressure in standing position was initially at the ankle 1.70 SD 0.44 and after 6 weeks 1.44 SD 0.29 (mean difference 0.27 SD 0.42, p < 0.03). CONCLUSIONS: The compression stocking maintained a therapeutically effective pressure profile over a period of six weeks. Working interface pressure was comparable to that of short-stretch compression bandages applied by an experienced bandager immediately after application.

Adult↗

PubMed2002

Is subungual melanoma related to trauma?

Subungual melanomas represent approximately 20% in dark-skinned and oriental populations compared to about 2% of cutaneous melanomas in white populations. UV exposure seems to be an important risk factor for cutaneous melanoma. However, UV radiation is unlikely to penetrate the nail plate. Another pathogenetic factor of subungual melanoma will be discussed. 406 subungual melanomas of the hands (n = 240) and feet (n = 166) of 74 patients from the melanoma registry of the Department of Dermatology, University of Tübingen, and of 332 patients from the literature were evaluated. The hypothesis of a uniform distribution of the occurrence of subungual melanoma on the fingers and toes had to be rejected (p < 0.001 using the chi(2)(4,0.95) test). There was a considerable predominance of subungual melanoma localized on the thumb (58% of all fingers) and the hallux (86% of all toes). Many patients report direct trauma related to the onset of subungual melanoma. This might be explained by coincidence, increased attention to a dark area under the nail, traumatic bleeding of a subclinical subungual melanoma or mutation of melanocytes during trauma-induced proliferation. Squamous cell carcinoma is known to occur in sites of chronic trauma. Trauma could be an etiologic factor in subungual melanoma as well.

Ethnicity↗

PubMed2001

[Medical compression therapy].

In order to evaluate the correlation between the pressure exerted by compression stockings and a resulting improvement in venous hemodynamics, we carried out an open, randomized, prospective study on 22 patients (11 women and 11 men with an average age of 55.1 [10.3]) with chronic venous insufficiency (CVI) in the clinical stages C1-4, Ep, AS, Ap, PR. Dynamic strain gauge plethysmography was used to measure the acute effect on venous hemodynamics of 9 different compression stockings in compression class 2 (A-D). At the same time when venous function parameters were monitored, we also measured the pressure exerted by the compression stockings during rest and exercise. With all compression stockings the average resting pressure fulfilled in reclined patients the specifications for compression class 2 (25-35 mmHg at the ankle, CEN). The compression stockings lengthened venous refill time t0 in a statistically significant degree. The improvement in venous function was correlated with the ratios of maximal working pressure to resting pressure while standing (r = 0.97, p < 0.001). Compression stockings belonging to the same compression class vary in their acute effect on venous hemodynamics. The efficiency of the different therapeutic compression stockings was largely dependent on the amount of fabric stretch, which can be characterized in vivo with the ratio of maximum exerted pressure during movement to that while standing still. A knowledge of the hemodynamic effectivity of the various compression stockings allows the optimal stocking selection for each patient and his individual clinical situation.

Adult↗

PubMed2000

[Compression stocking in treatment of ulcus cruris. An efficient alternative to bandages].

BACKGROUND AND OBJECTIVE: The aim of the study was to measure the pressure exerted on the skin with application of the specially designed UlcerCare compression stocking for treatment of chronic venous leg ulcers and simultaneously to objectify the improvement in venous function. PATIENTS/METHODS: Twenty patients with chronic venous insufficiency according to the CEAP Classification C1-4 EP AS, A14, AP, PR were examined. Static exerted pressure was measured while standing and the dynamic equivalent was measured during 10 repetitions of tip-toe exercise. The patients were wearing the standard stocking JOBST Medical LegWear UlcerCare (Beiersdorf AG, Hamburg, Germany). As a control for the effectiveness of the therapy on venous hemodynamics, the lower leg volume, calculated using optoelectronically-measured lower leg circumference and venous reflux, determined by strain gauge plethysmographically-measured venous refill time, were used. RESULTS: Use of the compression stocking system UlcerCare resulted in a decreased lower leg volume. This decrease was on average 5.3%, corresponding to 106 +/- 78 ml (p < 0.001). The calf and forefoot venous function parameters also improved. The venous refill time improved from 27.2 +/- 15.2 s to 45.0 +/- 27.4 s at the forefoot (p < 0.003) and from 10.5 +/- 4.5 s to 19.4 +/- 10.9 s at the calf (p < 0.002). The exerted pressure at the ankle while standing was 46.2 +/- 24.2 mmHg (resting pressure) and 48.5 +/- 27.2 mmHg during repetitive tip-toe exercises (mean exercise pressure). At the calf, the exerted pressure while standing was 40.7 +/- 26.9 mmHg (resting pressure) and during the repetitive tip-toe exercises it was 42.1 +/- 29.5 mmHg (mean exercise pressure). CONCLUSIONS: The exerted pressure of the UlcerCare compression stocking is equivalent to that of a class 3 medical compression stocking. This newly developed stocking diminishes venous reflux and reduces leg edema. These objectified effects suggest that the UlcerCare stocking is effective as compression therapy for venous ulcers.

Bandages↗

PubMed2000

[FOITS (fast optical in vivo topometry of human skin): new approaches to 3-D surface structures of human skin].

FOITS (Fast Optical In-vivo Topometry of human Skin) is a new technique for the three-dimensional analysis of the microstructures of the skin. Based on the surface roughness standards used in the metal-working industry, it uses computer-assisted strip analysis to process information gathered from high-speed, non-contact scanning. It is possible to visualise the mathematical data in 3D form. So far, surface relief parameters have had to be acquired indirectly by first making silicone casts of the skin and then digitalising them with image analysis, mechanical scanners or, more recent, laser profilometry and confocal microscopy. We selected the roughness parameters Ra, Rz and Rmax (DIN defined) and "positive" and "negative" volume to describe the skin surface. In 40 healthy volunteers we were able to define significant intra-individual differences in these roughness parameters, which were correlated with the location of the area of skin being scanned (p < 0.05). When healthy areas of skin were compared with areas of chronic eczema in 10 patients with neurodermatitis the differences in the above-mentioned roughness parameters were just as striking (p < 0.05). In patients with chronic atopic eczema there was a statistically significant correlation between changes in the parameters "positive" and "negative" volume, and the smoothing of the skin seen after 14 days of treatment with standard ointments (p < 0.02). Apart from its industrial uses, we see potential applications for FOITS in the investigation of quantitative and qualitative aspects of aging processes, physiological and pathological processes in the skin, and the effect of topical preparations applied to the skin.

Adolescent↗

PubMed2000

[A new optoelectronic measuring device for assessment of leg circumference in comparison with manual measurement].

For compression treatment to be effective in patients with chronic venous insufficiency, it is vital that leg circumference be measured accurately. If compression stockings are custom fit and appropriate for the medical indications, patient compliance will be high. Exact measurements of circumference and length are prerequisites for a good fit. The aim of the present study was to compare an opto-electronic device for the contact-free measurement of calf circumference with the conventional manual method using a tape measure. We investigated the differences between the results obtained with the two methods, and also their reproducibility. Circumferences were measured at defined heights on an anatomically shaped non-yielding leg model and on the leg of a healthy volunteer by 10 different experimenters both with the tape measure and with the opto-electronic device. The calf circumferences measured manually with the tape measure varied significantly more than those measured opto-electronically, both in the leg model and in the leg of the volunteer. A systematic error in the opto-electronic method appears unlikely, since the manual measurements on the leg model were both larger and smaller than those obtained with the opto-electronic device. Reproducibility was exceptionally high with the opto-electronic device (standard deviation 0.11-0.42 cm). The opto-electronic method yields rapid accurate measurements of circumference with excellent intra- and inter-operator reproducibility.

Anthropometry↗

PubMed2000

Microcirculatory dysfunction in chronic venous insufficiency (CVI).

The elevated ambulatory pressure in the peripheral venous system of chronic venous insufficiency (CVI) patients manifests itself not only in the form of disturbed macrocirculation but also and particularly in microangiopathic changes. For this reason, it is closely correlated with trophic disorders of the skin and can ultimately lead to ulceration. Using microcirculation research techniques, we are able to provide clear evidence of a typical microangiopathy in chronic venous insufficiency. Fifty CVI in Widmer stages I, II, and III were examined with fluorescence video microscopy, intravital video capillaroscopy, transcutaneous oxygen partial pressure measurement, TcpO2 and laser Doppler flowmetry. The effects of compression therapy with individually fitted compression stockings on capillary morphology were studied over a period of 4 weeks in 20 CVI patients in Widmer stages I and II. The capillary pressure was measured during simulated muscle contraction using a servo-null micropressure system. We periodically drew blood from the dorsalis pedis vein and a brachial vein of 11 healthy test persons and 8 patients with stage III CVI during experimental venous hypertension in order to evaluate the expression pattern of leukocyte adhesion molecules involved in inflammation: LFA-1 (CD11a), Mac-1 (CD11b), p150,95 (CD11c), CD18, VLA-4 (CD49d), and L-selectin (CD62L). In the same patients, we used immunohistochemical methods to examine clinically unaffected skin and the skin near an ulcer, focusing on the adhesion molecules ICAM-1, VCAM-1, and E-selectin. The microangiopathic changes observed with worsening clinical symptoms include a decrease in the number of capillaries, glomerulus-like changes in capillary morphology, a drop in the oxygen content (tcpO2) of the skin, increased permeability of the capillaries to low-molecular-weight substances, increased laser Doppler flux reflecting elevated subcutaneous flow, and diminished vascular reserve. These microangiopathic changes worsen in linear proportion to the clinical severity of chronic venous insufficiency. In patients with venous ulcerations, the baseline expression of LFA-1 and VLA-4 on lymphocytes, Mac-1 expression on the myeloid cell line, and L-selectin expression on all three cell lines was not significantly different form that in healthy controls. During orthostatic stress, there was a significant reduction in the expression of L-selectin in blood cells collected at foot level in the controls (p=0.002), but not in the patients. Clinical improvement by compression therapy was accompanied by an increase in the number of nutritive capillaries, while the diameter of the capillaries and the dermal papillae was reduced. When ulcers healed in a short period (<6 weeks), we observed a concomitant increase in the number of capillaries (p<0.05). Microangiopathy appears before tropic disorders of the skin develop. Even trophically normal skin areas may have dilated nutritive capillaries, an early sign of disturbed skin perfusion. These changes represent a plausible explanation for the development and to recurrency tendency of venous ulcers. The reduced expression of lymphocytic L-selectin in healthy controls during the orthostatic stress test may be an indication that the cells are activated by venous stasis. Clinically effective therapeutic measures improve the impaired microcirculation of the skin in the ankle area.

Bandages↗

PubMed1997

[Dynamic in vivo skin pressure measurement in quality control of compression stockings].

The well-documented positive effect of compression stocking therapy on the venous macro- and microhemodynamics of the legs can only be attained if the stockings fit well. In order to determine the effective pressure exerted by compression stockings, we usually deleted in US journals. One can get this out of journal and author's address have developed a new measuring method based on piezoresistant microprobes and a microprocessor unit. With our 2-mm-thick, 5-mm diameter probe, the pressure between the compression stocking and skin can be measured at any location desired. A temporal resolution of 50 Hz makes it possible to carry out dynamic measurements while the patient is walking or performing exercises on tiptoes. Here we present 4 typical cases out of a total of over 80 which we have evaluated. We have decided empirically that the pressure exerted by a class-2 compression stocking on the skin at the height of the ankles (b-position) should not exceed 70 mm Hg while resting and a peak of 110 mm Hg while exercising on tiptoes. At the middle of the calf (c-position) these values should not exceed 60 mm Hg at rest and 80 mm Hg on tiptoes. The pressure should decrease from the distal to proximal direction in order to produce a drainage gradient. We have found empirically that a pressure gradient of 30-40% from the b to the c measurement is favorable. Too high a proximal pressure or too high a pressure on a part of the lower leg causes pain and swelling. Too low a pressure, on the other hand, does not produce the desired vascular effect and alleviation of symptoms. Although dynamic pressure measurements take about 20-30 minutes per leg, they markedly improve patient compliance with compression therapy.

Adult↗