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Biomedical subjects

R A Neumann

Publications and source records attributed to R A Neumann.

At least 19 recordsLinked to original sources
PubMed1993

Results and tissue healing after copper-vapour laser (at 578 nm) treatment of port wine stains and facial telangiectasias.

Twenty-four patients with port wine stains (PWS), and 33 patients with facial telangiectasias were treated with a copper-vapour laser (CVL) operating at 578 nm. Good to excellent results were obtained in 52% of PWS and 69% of facial telangiectasias. Enzyme histochemistry revealed vessel-selective damage with energy densities up to 12 J/cm2, but a non-specific coagulation necrosis with higher fluences (> or = 15 J/cm2). With vessel-selective fluences only moderate blanching was obtained in two PWS. All other evaluated patients were treated using non-selective energy densities. Tissue healing was comparable with that after argon laser treatment. The theoretically correct wavelength (578 nm) alone appeared to be no guarantee of vessel-selective damage. The laser employed lacked adequate power (only 1.3 W maximum) to transmit sufficient energy into the tissues in a short exposure time. However, the clinical results confirm the value of the CVL in the treatment of superficial cutaneous angiodysplasias.

Adolescent↗
PubMed1992

Comparative histochemistry of port-wine stains after copper vapor laser (578 nm) and argon laser treatment.

The present study compared the histologic changes occurring 15 min after copper vapor laser (CVL; operating at 578 nm) and argon laser (488/514 nm) treatment of port-wine stains (PWS) over a range of energy densities (8-32 J/cm2) with corresponding pulse widths of 50-200 ms. Frozen tissue sections were stained with nitroblue tetrazolium chloride (NBTC). This histochemical method permits an accurate color differentiation between blue-stained viable and unstained thermally damaged cells. At 8, 10, and 12 J/cm2 the argon-laser injury was confined to epidermal cell layers; none to superficial dermal effects were found. Fluences of at least 15 J/cm2 produced a diffuse NBTC-negative coagulation necrosis. Exposure of PWS skin to 8-12 J/cm2 at 578 nm did not alter the integrity of epidermal cells. In the dermis, damage was confined to blood vessels and surrounding collagen, showing a clear demarcation from adjacent viable structures. The maximum penetration depth achieved with these vessel selective energy densities was 0.44 mm. At 15 J/cm2, besides vascular injury, damage to the basal cell layer also occurred. At fluences of 17-20 J/cm2 a diffuse necrosis similar to that induced by the argon laser was found. Vessel selectivity of the 578 nm wave band was achieved with pulse widths from 50-74 ms, exceeding the estimated "ideal" exposure time (0.1-10.0 ms) for a vascular selective laser effect. The NBTC method allowed identification of subtle laser-induced tissue changes providing accurate quantitative data relating to the extent of vascular injury.

Adult↗
PubMed1992

Accurate histochemical definition of argon-laser-induced tissue necrosis.

We present a histochemical method using the redox dye nitro blue tetrazolium chloride (NBTC) for the evaluation of argon-laser-induced tissue damage. By this method viable cells are stained blue, devitalized cells not. Our findings suggest that the NBTC staining method is more appropriate for the accurate definition of the necrosis and cell viability after laser treatment than routine histology.

Hemangioma↗
PubMed1991

Histochemical evaluation of the coagulation depth after argon laser impact on a port-wine stain.

A two-step excisional treatment of a port-wine stain (PWS) on the back of a 43-yr-old female patient was performed. Immediately before the first surgical treatment, two corresponding series of argon laser impacts were performed, each on one PWS half. Different laser parameters with irradiances ranging from 95 to 382 W/cm2 and energy fluences ranging from 19 to 114,6 J/cm2 were used. Laser spots on the first part ot be excised were biopsied 10 min after laser treatment and prepared for histochemical analysis by staining with nitro blue tetrazolium chloride (NBTC). Reduction of this redox dye by nicotinamide adenine dinucleotide diaphorase (NADH-diaphorase) leads on frozen tissue sections to an intense blue precipitate. The activity of NADH-diaphorase subsides immediately upon cell damage. All vital epidermal and dermal cells presented a dense blue granular pigment in their cytoplasm, sparing the nuclei. Laser induced arc-shaped epidermal and dermal necrosis did not stain, showing a clear demarcation from surrounding vital tissue. The depth of the thermal injury ranged from 0.28 to 0.45 mm; it did not correlate with the chosen fluences. With these penetration depths, the vast majority of PWS vessels was affected. Assessment of the remaining part of the PWS 8 months later yielded blanching of all laser-treated areas. With the NBTC method, an accurate definition of laser-induced tissue damage is feasible. It could be shown that the exposure time is the most relevant parameter influencing the penetration depth.

Adult↗
PubMed1991

Porokeratoses: immunohistochemical, light and electron microscopic evaluation.

Punch biopsy specimens of 14 patients with porokeratosis of Mibelli (n = 1), disseminated superficial porokeratosis (n = 6), disseminated superficial actinic porokeratosis (n = 4), porokeratosis plantaris, palmaris et disseminata (n = 2), and punctate porokeratosis (n = 1) were obtained for light and electron microscopy for evaluation of possible differences between these clinical variants. Langerhans cells in close contact with early degenerating keratinocytes could be observed in the epidermis. To study the cellular composition of the epidermal inflammatory infiltrate immunohistochemistry was performed. These studies demonstrated that the predominant cell type in these infiltrates are helper T cells, intermingled with Leu-6+ Langerhans cells. Despite the clinical variation and possible different etiologic or triggering mechanisms, the immunohistochemical and morphologic changes in all types of porokeratosis are the same and seem to represent a uniform reaction pattern.

Adult↗
PubMed1991

Abnormal epidermal changes after argon laser treatment.

A 26-year-old woman with a congenital port-wine stain on the forehead was treated three times at 2-month intervals with an argon laser. Six months after the last treatment, moderate blanching and mild scaling confined to the treated area was observed. A biopsy specimen of the treated area revealed a significant decrease in ectatic vessels. However, epidermal changes similar to those of actinic keratosis with disorganized cell layers and marked cytologic abnormalities were seen. Analysis of peripheral blood lymphocytes for a defect in DNA repair was negative. Multiple, argon laser-induced photothermal effects may be responsible for the changes observed in our case and may lead to premalignant epidermal transformation.

Adult↗
PubMed1991

Enzyme histochemical analysis of cell viability after argon laser-induced coagulation necrosis of the skin.

Reduction of nitroblue tetrazolium chloride, a redox indicator, by nicotinamide adenine dinucleotide diaphorase produces in frozen tissue sections an intense blue cytoplasmic pigment. The activity of this enzyme has been shown to subside immediately upon cell death. Twelve patients with port-wine stains were treated with an argon laser. Frozen tissue sections from biopsy specimens obtained before and 10 minutes, 24 hours, and 48 hours after laser application were processed for nitroblue tetrazolium chloride staining. In normal skin all epidermal and dermal cells displayed dense cytoplasmic blue granular pigment that spared the nuclei. In port-wine stains the laser-induced coagulation necrosis was first seen as an arc-shaped, sharply demarcated, unstained, nitroblue tetrazolium chloride-negative area. Initiation of epidermal repair could be observed in all 48-hour sections. The nitroblue tetrazolium chloride method, when compared with hematoxylin and eosin staining, allowed an easier and more accurate definition of laser injury because of the color difference between damaged and normal tissue.

Adult↗
PubMed1991

Photoelectric quantitative evaluation of argon laser treatment of port wine stains.

Sixty patients with port wine stains were treated with the argon laser and graded visually into four subjective categories for changes in skin colour. For objective quantitative evaluation a photoelectric colorimeter was used. Reproducible definition of the lightness of the lesions into numbers was obtained. Differentials in lightness between normal contralateral skin and the port wine stain before and after treatment were quantified for each individual. The objective evaluation revealed a statistically significant difference between the four categories (P less than 0.05). The best clinical therapeutic effect was found to correlate with only 80-90% blanching. The average lightening obtained was 46.5%. Local heating of port wine stains in 12 patients showed no measurable darkening in the colour of the lesions, whereas the normal contralateral skin reacted with marked reddening. Determination of changes in lightness by photoelectric colorimetry provides an objective, quantitative means to evaluate the effects of laser treatment of port wine stains.

Adolescent↗
PubMed1990

Xanthoma disseminatum with progressive involvement of the central nervous and hepatobiliary systems.

A rapidly progressive disease with multiple organ involvement and symptoms of polyuria and polydipsia developed in a 32-year-old woman, with an initial presentation of xanthoma disseminatum. Within 6 months increasing visual impairment of the right eye developed; a computed tomographic scan revealed multiple cerebral and cerebellar lesions. Progress of her disease resulted in blindness of the right eye, internal hydrocephalus with involvement of both ventricles, and cerebellar ataxia. Ultrasound examination of the abdomen and a subsequent endoscopic retrograde cholangiopancreatographic examination revealed a xanthomatous gallbladder and liver involvement. The gallbladder and liver showed histologic changes compatible with xanthomatosis. The patient died 4 years after the appearance of skin lesions.

Adult↗
PubMed1990

Venous lakes (Bean-Walsh) of the lips--treatment experience with the argon laser and 18 months follow-up.

The intense blue-green light of the argon laser has proven very effective in the treatment of a great variety of vascular skin disorders. Venous lakes (Bean-Walsh) of the lips are blood-filled dome-shaped lesions, their treatment often requiring surgery. Fifty-one patients suffering from this disorder were treated with the argon laser with 1.5-2.0-mm spot size, 0.3-s pulse duration and 1.8-3.0-W power. In most cases treatment was carried out without local anaesthesia. Laser impact was followed immediately by shrinking of the lesions and replacement by a whitish-grey plaque. Excellent cosmetic results were obtained in 90% of the patients. Three patients showed mild scarring. At 18 months follow-up only one patient showed a recurrence. The argon laser appears to be a highly effective non-invasive treatment modality for venous lakes of the lips.

Adult↗
PubMed1990

Argon laser treatment of small keratoacanthomas in difficult locations.

Seventeen patients (mean age, 64.7 years) with solitary keratoacanthomas (KA) located on the face and auricles were treated with the argon laser. All lesions were less than 10 mm in diameter and had been present for 2-10 weeks (mean, 3.8 weeks). The diagnosis was made clinically and was confirmed by histology. The lesions were treated with the argon laser using the continuous exposure technique with a power setting of 4.5 watts (W) and a beam diameter of 1 mm. Complete re-epithelialization occurred within 14-21 days. Excellent treatment results were achieved in 65% of the patients. Thirty-five percent healed with mild scarring. During a follow-up period of 2 years no recurrences were noted. The use of the argon laser for removal of small KAs in difficult locations, which would often require invasive surgery, appears to be an effective additional treatment modality.

Aged↗
PubMed1990

Exacerbation of porokeratosis during etretinate therapy.

Four patients with disseminated superficial porokeratosis (DSP) were treated with the oral aromatic retinoid etretinate. Using the standard dosage of 1 mg/kg/day, 3 patients showed exacerbation of cutaneous lesions 4-6 weeks after initiation of treatment. Because of additional severe generalized itching and discomfort in all patients, treatment had to be discontinued. The clinical exacerbation correlated with a significant increase in the lymphohistiocytic dermal infiltrate beneath the cornoid lamella. In our experience the use of etretinate triggered the exacerbation of porokeratotic lesions with associated side effects showing that their use is not necessarily of benefit as previously reported.

Aged↗
PubMed1989

DNA dot-blot hybridization implicates human papillomavirus type 11-DNA in epithelioma cuniculatum.

Epithelioma cuniculatum is a rare, low-grade squamous cell carcinoma, belonging to the group of verrucous carcinomas. Evidence is presented that suggests that human papilloma virus type-11 may be involved in the pathogenesis of epithelioma cuniculatum. HPV-DNA was detected by dot-blot hybridization with 32P-labelled probe DNA. Plasmids containing HPV-DNA were isolated by the benzoylated naphthoylated DEAE cellulose method (BND-method), an improved procedure for routine detection of HPV-DNA.

Aged↗
PubMed1989

Evidence for spirochetal origin of Sudeck's atrophy (algodystrophy, reflex sympathetic dystrophy).

Four female patients with Sudeck's atrophy (SA) were evaluated at our department. Sera of all patients were investigated for antibodies against Borrelia burgdorferi. In all patients elevated IgG antibody titers and in one patient also elevated IgM titer were found. In one patient structures identical with B. burgdorferi could be detected on histological sections from the skin of the affected limb. Our data and those of other authors suggest that a spirochetal infection can be regarded as an important etiopathogenetic factor in the development of SA.

Adult↗
PubMed1989

Unusual presentation of porokeratosis palmaris, plantaris et disseminata.

Porokeratosis plantaris, palmaris et disseminata is an autosomal dominant genodermatosis characterized by multiple lesions on the palms and soles, and later on other areas, both sun-exposed and non-sun-exposed. We report a 66-year-old man with porokeratosis plantaris, palmaris et disseminata whose disease had an unusual evolution. To our knowledge this is the first case of the disease in which the lesions first appeared on the trunk and extremities and later involved the palms and soles.

Aged↗
PubMed1989

Disseminated superficial actinic porokeratosis: experimental induction and exacerbation of skin lesions.

A 55-year-old woman with disseminated superficial actinic porokeratosis (DSAP) had lesions on sun-exposed skin areas that were exacerbated during the summer months and involuted in winter. This is the third report in which induction and exacerbation of DSAP lesions were achieved by irradiation with artificial ultraviolet light sources. Our data show that UVB plus UVA is more effective in inducing new or exacerbating preexisting skin lesions than either wavelength alone. We believe that testing with the appropriate ultraviolet light sources is a practical means to differentiate between DSAP and disseminated superficial porokeratosis.

Female↗