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J Wohlrab

Publications and source records attributed to J Wohlrab.

At least 37 records · Page 2Linked to original sources
PubMed2001

The NO release test as a functional reference standard for laser Doppler fluxmetry in cutaneous microangiology.

BACKGROUND/AIMS: The application of one-dimensional laser Doppler fluxmetry (LDF) to clinical research is widespread. Large intra- and interindividual fluctuations in perfusion impede the objective evaluation of studies and hinder a standardised reproducibility. Attempts are made to minimise these biological fluctuations of the measured values by means of functional tests, standardised measuring conditions and large study populations. An intraindividual fixed standard that also facilitates interindividual comparability as a reference parameter would be desirable. METHODS: By applying a nitric oxide (NO) release cream, a maximal vasodilatation is produced in a circumscribed skin area and optically registered by means of LDF. An LDF quotient is defined as a measure of the reproducibility. A total of 123 test subjects with dermatological diseases were measured at intervals of 60 min on the volar underarm on clinically normal skin with and without NO release cream. RESULTS: The LDF quotient of the NO release test represents a stable, readily reproducible individual parameter and is appropriate as a reference standard for resting flux measurements. Therefore, we define an LDF factor that includes the maximal vasodilatation as a specific assessment characteristic and thus allows a more powerful, functionally oriented assessment of the individual measurements. CONCLUSION: The NO release test is appropriate as a reference standard for laser Doppler fluxmetry and realises a high reproducibility of individual measurements.

Humans↗
PubMed2001

Diagnostic impact and sensitivity of skin biopsies in Sneddon's syndrome. A report of 15 cases.

BACKGROUND: Sneddon's syndrome is defined as a combination of idiopathic livedo racemosa generalisata and symptoms of cerebrovascular defect. The disease usually starts with vascular symptoms in the epidermis, with neurological deficits becoming evident later. For this reason, histological examination of skin biopsies and determination of arteriolar occlusion is of particular importance for reliable categorization and early diagnosis. To date, these methods have been considered to be too insensitive. OBJECTIVES: To evaluate the sensitivity of skin biopsies in Sneddon's syndrome. METHODS: We took a total of five deep punch biopsies (4 mm) from different areas of the livedo (three from white and two from red areas) in 15 patients. Present knowledge of the pathogenic relationships and the particular anatomical features of the skin were taken into account. RESULTS: The method had a sensitivity of 27% with one biopsy, 53% with two biopsies and 80% with three biopsies taken from white areas in all cases. CONCLUSIONS: Skin biopsies using the method presented achieved a high sensitivity, suggesting that the diagnosis in clinically suspected cases could be confirmed in the majority of cases with this technique.

Adolescent↗
PubMed2001

Investigation of the penetration behaviour of mycophenolate mofetil from a semisolid formulation into human skin ex-vivo.

Mycophenolate mofetil, the morpholinoethylester of mycophenolic acid, is an immunosuppressant used in combination with ciclosporin (cyclosporin) and corticosteroids to prevent organ rejection after heart and kidney transplantations. The drug seems also to be effective in dermal diseases after systemic administration. However, up to date mycophenolate mofetil can be only systemically administered and this is associated with several side effects such as nausea, leucopenia, sepsis, and diarrhoea. The aim of this study was to develop a topical formulation containing mycophenolate mofetil and to investigate in-vitro release and penetration into human skin ex-vivo. HPLC was applied to quantify mycophenolate mofetil after release studies from semisolid formulations using a dodecanol-collodion membrane as a lipophilic acceptor. Penetration studies with an amphiphilic cream using excised human breast skin were carried out in Franz-type diffusion cells. Mycophenolate mofetil and its active metabolite mycophenolic acid were detected by HPLC-MS after microsectioning in different skin layers. In this study the penetration of mycophenolate mofetil from an amphiphilic cream into excised human skin was shown. Additionally, the enzymatic hydrolysis of penetrated mycophenolate mofetil into mycophenolic acid was proven even under ex-vivo conditions. In-vivo a higher extent of metabolism of mycophenolate mofetil to mycophenolic acid would be expected because of the complete enzyme activity. This topical formulation might be a promising alternative to the usual systemic administration of mycophenolate mofetil in the treatment of skin diseases such as psoriasis.

Adult↗
PubMed2000

[Analysis of serum zinc level in patients with atopic dermatitis, psoriasis vulgaris and in probands with healthy skin].

BACKGROUND AND OBJECTIVE: The significance of zinc in the pathogenesis of different dermatological conditions is controversial. Using our own patient collective, the present study aimed to determine variations in serum zinc levels in patients with atopic dermatitis and psoriasis as compared to levels in the normal population. PATIENTS/METHODS: The serum zinc levels of 97 patients with atopic dermatitis and 88 patients with psoriasis were compared to those in 22 healthy subjects and subjected to statistical analysis. RESULTS: In contrast to the data given in the literature, no statistically significant difference was found between the populations investigated. CONCLUSIONS: Zinc replacement therapy in patients with atopic dermatitis and psoriasis appears to be indicated only in those with a documented zinc deficiency.

Adult↗
PubMed2000

[Ultrasound characterization of burn scars in children].

So far, little is known about the acoustic phenomena of high-frequency sonography for the assessment of healing processes in thermal wounds. However, ex vivo investigations have shown clear age-dependent differences in the rate of sound propagation in thermal scars compared to healthy skin. In order to answer the question of whether measurable acoustic characteristics of burn or scald scars can be classified in a way which corresponds to the clinical severity of the injuries, age of scar or type of treatment, 92 thermal scars, with an average scar age of 3.1 years, in 55 children were investigated with regard to corium thickness and echogenicity. A control group of 25 non-injured children of similar age was studied for comparison. It was shown that measurable echogenicity differences can allow conclusions about clinical severity to be drawn. The comparison of different therapeutic strategies showed no therapeutic effect either for compression or for the application of silicone gel sheets. In contrast, a decrease in scar thickness and a loosening of scar structure could be seen after early application of a sterile, silicone-covered polyamide net bandage. The 20-MHz-Sonography is a suitable non-invasive procedure for the characterisation of burn scars.

Age Factors↗
PubMed2000

Electrophysiological characterization of human keratinocytes using the patch-clamp technique.

The living, not-cornified part of the epidermis consists mainly of keratinocytes. The control mechanisms of proliferation and differentiation are only partly understood. Similarly, the influence of ionic channels of the cell membrane on the proliferation of keratinocytes remains unclear. Preliminary investigations point to a relation between the opening of ionic channels and keratinocyte proliferation. Therefore, voltage clamp experiments were performed to gain further knowledge of the electrophysiological characteristics of human keratinocyte cellular membranes. In-vitro cultured keratinocytes of the cell line HaCaT were characterized by means of the voltage-clamp technique. As measured in the whole-cell configuration, changing the extracellular K+ or Cl--concentration shifted the membrane potential of HaCaT cells. Application of the patch-clamp-technique in the cell-attached and inside-out configuration revealed an ionic channel with a conductance of multiples of 200 pS. The reversal potential of the single channel current was shifted by substituting of intracellular Cl- by aspartate-. Channel openings disappeared after addition of 0.1 mM of the anion channel blocker 4',4' diisothiocyanato-stilbene-2-2' disulfonic acid (DIDS). It is concluded that this channel contributes to the Cl--conductance of the cellular membrane and is a determinant of the membrane potential of human keratinocytes. This channel may represent a target for pharmacological manipulation of the membrane potential and possibly the growth of human keratinocytes in dermatological proliferation disorders.

Cell Division↗
PubMed2000

Granulomatous mycosis fungoides. Report of two cases and review of the literature.

BACKGROUND: Granulomatous mycosis fungoides is an extremely rare type of cutaneous T-cell lymphoma. Two cases are described and checked for clinical, histological and therapeutic differences to other variants of mycosis fungoides. CASE REPORTS: Case 1: a 52-year-old patient with livid plaques covering the whole integument. Histological findings showed granulomas with multinuclear giant cells in addition to a malignant lymphohistiocytic infiltrate (monodonal T-cell receptor (TCR)-gamma rearrangement). Despite various chemotherapeutic regimens, progression to tumour stage was observed. Case 2: an 88-year-old man with plaques and ulcerating tumours on the trunk and head. Histological findings showed malignant T-lymphocyte infiltrate (monoclonal TCR-gamma rearrangement) and granulomas with multinuclear foreign-body giant cells. Complete regression of all lesions was achieved using both local psoralen-ultraviolet A and electron radiotherapy. CONCLUSIONS: The diagnosis of a granulomatous mycosis fungoides depends exclusively on the histological demonstration of granulomas. Distinct clinical characteristics are not present. Apart from granuloma formation, no other noticeable histological features are evident. The presence of granulomas in mycosis fungoides does not have prognostic implications, as cases with aggressive, but also with a prolonged course have been described.

Aged↗
PubMed2000

Acute effect of a dried ethanol-water extract of garlic on the microhaemovascular system of the skin.

In the present study, the acute vasoactive effect of a dried hydrophilic extract of garlic with 600 mg active substance (Alliosan) was investigated in 10 healthy volunteers. Laser-Doppler fluxmetry, video capillary microscopy and transcutaneous partial pressure of oxygen measurements were used for the objective assessment of functional and morphological parameters. An increase in perfusion could be demonstrated by these means. This was based on an increase in erythrocyte flow velocity of up to 2 h duration, which was mainly due to vasodilation in both arterial and venous vessels. A change in transcutaneous partial pressure of oxygen or an influence on sympathetically-mediated vasomotor reflexes could not be demonstrated. Furthermore, there was no evidence of an influence on reactive hyperaemia after controlled hyperthermia. The test substance was shown to increase the cutaneous microperfusion.

Adult↗
PubMed1999

[Ranking of 20 MHz sonography of malignant melanoma and pigmented lesions in routine diagnosis].

PURPOSE: Eleven dermatology clinics from all over Germany took part in our multicenter prospective study with the aim of evaluating 20 MHz sonography in the preoperative diagnosis of malignant melanomas and other pigmented skin tumours. It was to be assessed how effective sonographic measurement of thickness would compare to histology and the clinical palpation of tumour thickness and also the significance of differential diagnosis in sonography of malignant melanomas. METHOD: The prospective multicenter study proceed as follows. To the end of August 1997 264 patients with a primary malignant melanoma and 417 patients with benign skin tumours were examined via 20 MHz sonography. Two different examiners estimated the clinical thickness of the tumour by palpation. The tumour was then excised and examined for postoperative correlation with the histology sections. RESULTS: The final results showed good correlation between the histological and sonographic estimation of tumour thickness (r = 0.97). Estimation of tumour thickness by palpation showed no correlation with the histology (r = 0.59). Most of the benign (44%) and malignant tumours (38.7%) were spindle shaped. There was no significant difference between the benign and malignant tumour groups in relation to the sonographic presented shapes or echo signs. No different diagnosis could be made. CONCLUSION: The technique of high frequency sonography in relation to preoperative diagnosis of malignant melanomas has high priority. In contrast to clinical estimation of tumour thickness, sonography provided a good correlation to histology. The effectiveness of sonography with regard to the valence of the skin tumours is limited and there is no possibility of differentiating between malignant and benign tumours from the morphological face value. Hence, there is a demand for developing a 150 MHz apparatus which will be able to supply evidence regarding the valence of skin tumours.

Diagnostic Tests, Routine↗
PubMed1999

Submammary granular parakeratosis: an acquired punctate hyperkeratosis of exogenic origin.

Granular parakeratosis is a histologic phenomenon that produces a characteristic clinical picture with multiple brownish and hyperkeratotic papules. In all 6 published cases of localized axillary parakeratosis, excessive use of different topical preparations (cream-type products, deodorants that include roll-on and stick types, antiperspirants, shampoos, bath soaps) was reported by the authors. The exact pathogenic causal relationships have not yet been resolved. In the case reported below, we demonstrate for the first time that the macro- and micromorphological entities can also occur in the submammary region.

Adult↗
PubMed1999

[Radiation-induced morphea].

Although the aetiology of morphea often remains unknown, various precipitating causes have been identified. Morphea is a rare development following irradiation. We observed a circumscribed scleroderma 14 years after x-ray-radiotherapy following surgery of breast cancer. Furthermore multiple weeping papules occurred within the radiation area. A relapse of the breast cancer was ruled out by histological examination which displayed a transepidermal elimination of acid mucin. The irradiation had obviously induced different reactions of the dermal fibroblasts (radiodermatitis, morphea, mucin production).

Breast Neoplasms↗
PubMed1998

[Burns from undisclosed acids in a liquid used by temporary workers. A recent problem in occupational medicine caused by a lack of information].

HISTORY: Two temporary labourers, on piece work without sufficient prior instructions, were employed to clean a house facade. During the work, at first limited to 5-10 minutes, they sustained chemical burns from the hydrofluoric and hydrochloric acids contained in the liquid used to clean the stone. Both workers had been left uniformed about the danger or kind of the material being used, because of their short-time employment. They only sought medical help several hours later. ADMISSION FINDINGS: At the areas of contact with the cleansing liquid (hands, lower arms and thighs, in case 1; additionally at first well circumscribed and very painful areas of erythema, developing within a few hours into blisters, in case 2; also erosions in both). INVESTIGATIONS: Chemical burns by hydrofluoric acid were only elucidated as the cause 24 hours after exposure. Repeat tests (ECG, blood gas analysis, electrolyte levels) provided no evidence of deep-seated burns at the contact areas or systemic poisoning. Radiology of the hand was normal. TREATMENT AND COURSE: As there was at first no indicative history, toxic contact dermatitis was suspected and treated topically with Clobetasol-17-propionate. Once the true cause became known treatment consisted of compresses with 10% calcium gluconate solution. All lesions healed completely within 4 and 6 days, respectively. INTERPRETATION: Temporary workers are often insufficiently instructed, despite clear legal regulations. Such lack of informations increases the risk of harm to workers and makes appropriate treatment more difficult.

Administration, Topical↗
PubMedDate not supplied

Cutis marmorata telangiectatica congenita: laser doppler fluxmetry evidence for a functional nervous defect.

We report a 5-month-old infant with cutis marmorata telangiectatica congenita (CMTC) without associated abnormalities and unusual hemicorporal vascular markings. Laser Doppler fluxmetry of the involved skin, carried out for the first time, and the measurement of the transcutaneous partial pressure of oxygen indicate a functional disturbance, which may be the expression of an alpha-adrenergic innervation deficit of the cutaneous terminal blood vessels.

Female↗