Biomedical subjects

B Boateng

Publications and source records attributed to B Boateng.

4 recordsLinked to original sources

PubMed1995

[Multiple keratoacanthomas (Witten-Zak type) in prurigo simplex subacuta].

We report on the case of a 51-year-old female patient who had been suffering from multiple itching nodules for 3 years. Some of these lesions were classified clinically and histologically as keratoacanthomas (KA), whereas the multiple smaller nodules were found on histological examination to be either early stage KA or lesions of prurigo simplex subacuta. In two KA, HPV subtype 2 was identified by in situ hybridization. Treatment with etretinate resulted in remission of the fully developed KA and reduced the occurrence of new ones. The outbreak of multiple KA in our patient resembled a rare subtype described by Witten and Zak. Postclinical follow-up for 28 months to date has revealed that the KA arise from the subacute prurigo lesions. This mode of prurigo-dependent KA development has not previously been reported.

Biopsy↗

PubMed1995

[Disordered cutaneous microcirculation in diabetic neuropathic foot ulcer. Is modification by retrograde transvenous perfusion therapy possible?].

Due to the high risk of amputation they involve, diabetic neuropathic plantar ulcers (DNPU) must be regarded as a late manifestation/complication of diabetes mellitus. The suspected cause of these ulcers--disturbed cutaneous microcirculation--was studied by simultaneously measuring laser-Doppler flux (LDF) and cutaneous oxygen tension (pCUO2) in 14 patients with DNPU at three differently affected sites (dorsal forefoot, ulcer edge, lower leg). Dynamic tests (arterial occlusion, local hyperthermia) as a measure of vascular reactivity showed significantly reduced pCUO2 parameters coinciding with elevated LDF values. This reflects a shift of blood flow from the nutritive capillaries towards deeper vessels. Abolition of normal vasoconstriction in the arteriovenous shunt vessels by diabetic polyneuropathy is the assumed cause of increased AV perfusion, with a consequent rise in LDF values. In a subgroup of the above patients (n = 7) undergoing daily intravenous retrograde perfusion therapy (RVP) over 10 days several basic and dynamic microcirculatory functions were studied before and after this treatment. This subgroup showed on the forefoot and the lower leg a remarkable improvement of the microcirculatory parameters investigated, suggesting a better oxygen supply to the tissues after RVP therapy.

Adult↗

PubMed1995

[Dynamic function tests for detection of physiologic and pathophysiologic reactions in cutaneous microcirculation].

Functional tests simulating local stresses are especially suitable for the evaluation of physiological and pathophysiological patterns in the cutaneous microcirculation, particularly if combined with non-invasive methods such as laser-Doppler fluxmetry and oxygen tension measurements. Arterial occlusion (3 min) and local heating (up to 42 degrees C) are appropriate as stimuli to simulate specific local demands on the cutaneous perfusion similar to those produced by pressure, myokinesis, heat, and inflammation. When the current microcirculatory status is described the initial values (LDF and pO2) and their time-courses during each functional test can be used to determine the so-called post-stimulatory parameters. These-- corresponding to physiological equivalents--allow statements on the vascular reactivity towards hypoxia and ischaemia. Furthermore, dynamic performance parameters can easily be derived from the poststimulatory values. They describe the capacity of cutaneous microcirculation with regard to perfusion reserves and ischaemic tolerance in local stress situations in an appropriate manner. As an example of the usefulness of functional tests for cutaneous microcirculation, the physiological and pathophysiological patterns found in systemic sclerosis are described.

Blood Flow Velocity↗

PubMed1993

[Cutaneous microcirculation in pretibial necrobiosis lipoidica. Comparative laser Doppler flowmetry and oxygen partial pressure determinations in patients and healthy probands].

Necrobiosis lipoidica (NL) is a chronic, skin disease usually localized pretibially and often associated with diabetes mellitus. Primary vascular disturbances are considered pathogenetic for NL. In order to determine microcirculatory alterations in "idiopathic" NL linked with neither arterial hypertension nor diabetes mellitus, we performed simultaneous measurements of laser-Doppler flux (LDF) and oxygen tension (pcuO2) in 10 non-diabetic patients with NL and in 10 age- and sex-matched healthy volunteers. We examined the centre of the pretibial NL plaque, its border and the non-affected skin of the proximal lower leg at probe temperatures of 36 degrees C (flux) and 37 degrees C (pcuO2). Corresponding sites and temperatures were chosen for the controls. In addition, the degrees of hyperaemia caused by arterial occlusion (3 min) and during local heating (42 degrees C) were continuously measured. The initial pcuO2 values were found to be lowered, in contrast to increased fluxes within and around the NL lesions. In addition, responses of both flux and pcuO2 to the hyperaemic stimuli were weaker than in the corresponding skin of the healthy controls. Only minor differences from controls or none at all were found in clinically unaffected lower leg skin of the patients. Our results indicate a local alteration of microcirculation in patients with "idiopathic" NL that occurs independently of diabetes.

Adult↗