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Biomedical subjects

B Greve

Publications and source records attributed to B Greve.

At least 19 recordsLinked to original sources
PubMed2006

[Laser therapy for vascular lesions].

The use of lasers to treat vascular lesions began in the late 1960s with the introduction of argon laser. More recently pulsed laser and intense pulsed light techniques have further improved results and reduced side effects. Their function is based on the principle of selective photothermolysis. Simultaneous application of cooling methods (contact cooling, cold air, cryogen spray) has become standard procedure for these types of therapy, whose most important indications are port-wine stain, hemangioma, and telangiectasia. A persistent difficulty is their limited penetration, resulting in limited or no effect on deeper dermal layers. New approaches therefore include combinations with bipolar radio frequency or the use of two different laser systems, e.g., dye and Nd:YAG lasers. The different lasers are described along with their effectivity, limitations and indications.

Combined Modality Therapy↗
PubMed2006

Electro-optical synergy (ELOS) technology for nonablative skin rejuvenation: a preliminary prospective study.

BACKGROUND AND OBJECTIVES: In this preliminary prospective study, we evaluated the efficacy and safety of nonablative wrinkle treatment using combined radiofrequency (RF) and optical energy (Polaris). The dual energy technology of Polaris, called ELOS, which stands for electro-optical synergy, uses synchronous pulses of bipolar RF current and pulsed visible light (diode laser) delivered in the same pulse. MATERIALS AND METHODS: Twenty-four subjects with periorbital and perioral wrinkles received six treatments at 4-week intervals with the Polaris WR (Syneron, Inc., Israel, 900 nm, max. RF energy 100 J/cm(3), max. laser energy 50 J/cm(2)). Each treatment consisted of two passes over the treatment area using pulsed optical and RF parameters that were determined by the patient's skin phenotype and distribution of target chromophores. The follow-up period was 3 months after the last treatment. RESULTS: Independent scoring of blinded photographs showed a wrinkle score improvement of at least 1 (0 = no improvement, 1 = medium, 2 = good, 3 = excellent improvement) 3 months after the last of six treatment sessions. There was no difference between periorbital and perioral wrinkle reduction. Fifty-eight per cent (14/24) of the subjects reported a notable wrinkle reduction; 16% noted mild to moderate oedema and erythema lasting for no more than 1 day. Scarring or pigmentary changes were not detected. The average pain score was 0.6 (0 = no pain, 5 = intolerable pain). CONCLUSION: Multiple treatments with the Polaris WR produced objective and subjective reduction of periorbital and perioral wrinkles. The occurrence of side-effects and pain was very low. The clinical effect may be caused by matrix coagulation of the deep dermis by the RF and selective thermolysis of blood vessels with the 900 nm diode laser.

Adult↗
PubMed2004

[Reticulohistiocytoma. Treatment with pulsed-dye laser].

Reticulohistiocytoma is a rare non-Langerhans-cell histiocytosis. On exposed skin areas it is a cosmetic problem and can cause mechanical irritation due to its prominent nature. We successfully treated a histologically confirmed reticulohistiocytoma on the back of a 60 year old woman with a pulsed dye-laser (wavelength 585 nm, pulse 0.45 msec). The lesion regressed significantly after the first treatment (spot size: 7 mm, fluence 7.8 J/cm(2)). After another laser treatment, the lesion completely disappeared. At 28 month follow-up, no recurrence was seen. Permanent side effects were not observed. In our case report the use of the pumped pulsed dye-laser has proven to be an elegant and low risk treatment option for reticulohistiocytoma. The mechanism of action remains unknown.

Female↗
PubMed2004

[Repigmentation of persistent laser-induced hypopigmentation after tattoo ablation with the excimer laser].

Hypopigmented skin developed following tattoo removal with the Q-switched Nd:YAG laser. The hypopigmented area remained unchanged for over 4 years, until the use of the 308-nm xenon-chloride excimer laser induced a significant repigmentation in 40 sessions over 14 months. The excimer laser has the potential to influence the reduced activity of the melanocytes, as demonstrated with electron microscopy.

Adult↗
PubMed2004

[Excimer laser. Treatment of iatrogenic hypopigmentation following skin resurfacing].

As skin resurfacing has become more common, the number of patients developing post-treatment hypopigmentation has increased. No effective treatment for this complication has been developed. Some hypopigmented disorders, including vitiligo, have been treated with the excimer laser. We used the XeCl excimer laser to successfully treat a 78-year-old woman with perioral leukoderma following CO(2) laser skin resurfacing. The repigmentation was stable for at least 16 months. Larger prospective studies of this new therapeutic intervention are recommended to evaluate its efficacy and long-term stability.

Aged↗
PubMed2003

[Medical dermatologic laser therapy. A review].

The medical indications for laser therapy have been somewhat overlooked, perhaps because of the success of cosmetic laser therapy. As a result, many effective medical treatments are not covered by insurance companies. Lasers are helpful in many aspects of dermatologic treatment. Examples include pigmented lesions (Becker nevus), benign tumors (organoid nevi, adenoma sebaceum), dyschromias (traumatic tattoos), inflammatory diseases of the skin and subcutaneous tissue (lupus erythematosus, scars), hypertrichosis, premalignant lesions, and vascular lesions (hemangiomas and malformations). The various disorders which can effectively be treated with lasers are reviewed.

Adenoma↗
PubMed2003

[Diffused traumatic dirt and decorative tattooing. Removal by Q-switched lasers].

BACKGROUND AND OBJECTIVE: Pigment fanning or spread is one complication of decorative tattooing, but is also seen after traumatic tattoos. The reason for this spreading remains unclear. While excision of the diffused pigment was previously considered the treatment of choice, today destruction of the pigment with Q-switched laser systems is the therapy with the highest efficiency and lowest rate of side effects. Therefore areas of pigment spread should be excised only in rare exceptional cases. PATIENTS/METHODS: 4 patients with pigment fanning after permanent make up and traumatic tattooing of the periorbital region were treated with the Q-switched ruby (694 nm) and Q-switched Nd:YAG (1064 nm) lasers. RESULTS: All patients showed a significant (70-80%) clearance of the spread pigment; two had complete clearing. Side effects such as hyper- or hypopigmentation, scarring or ink darkening were not seen. CONCLUSIONS: The Q-switched ruby- and Q-switched Nd:YAG-lasers are a therapeutic modality for pigment fanning with high efficiency and low rate of side effects. Attempts of explanation for pigment spread after tattoos are given, but further histological and electron microscopical investigations are needed to find the pathogenetic mechanism.

Child↗
PubMed2002

[CO(2) and Er:YAG lasers in dermatology and aesthetic surgery].

In the past few years, the spectrum of indications for ablative lasers in dermatology and aesthetic medicine has been expanded due to technological innovations. In the following, technical basics, laser-tissue interactions, indications for the CO(2) and Er:YAG laser and laser treatment management are described. In addition, side effects and reactions associated with the use of these laser systems are listed and compared.

Humans↗
PubMed2002

["Skin rejuvenation" by non-ablative laser and light systems. Literature research and overview].

Currently, ablative laser therapy (with CO2/Er:YAG lasers) and deep chemical peeling are effective and promising methods of skin rejuvenation. The induction of collagen synthesis was observed after peelings with trichloroacetic acid or phenol as well as after treatments with the CO2 laser. In past years, the undesirable side effects and risks of these methods have led to intensified research in the fields of non-ablative facial rejuvenation and subsurfacing by means of ablative laser systems and intense pulsed light systems. The objective is to achieve selective, heat-induced denaturalisation of dermal collagen that leads to subsequent reactive synthesis but does not damage the epidermis. Recently, the results of numerous clinical and histological studies have indicated that these new technologies are successful. After critical review and assessment of current literature, we can say that in terms of their efficacy, non-ablative methods are not a comparable alternative to ablative skin resurfacing.

Female↗
PubMed2002

A novel true volumetric method for the determination of residual leucocytes in blood components.

BACKGROUND AND OBJECTIVES: Accurate determination of residual leucocytes [white blood cells (WBC)] in blood components is of high clinical importance. To date, several labour-intensive, time-consuming or expensive techniques have been used for this purpose. MATERIALS AND METHODS: A method for the determination of residual WBC is described using a novel low-cost flow-cytometric cell counter and analyser (CCA). The DNA in WBC was stained using 4'-6-diamidino-2-phenylindole (DAPI) and WBC were automatically analysed by true volumetric counting of 200-microl samples (prepared from a 20-microl undiluted sample). RESULTS: Dilution experiments over a range of 0.5-50 WBC/microl showed a linearity of r = 0.998. The detection limit of this method was 0.83 WBC/microl of red blood cell concentrate (RCC) and 0.67 WBC/microl of platelet concentrate (PC), with an accuracy of 95.5%. CONCLUSION: Residual WBC (< 1 WBC/microl) can be accurately counted using the CCA within 2 min and at a total cost of less than euro 1 per sample.

Blood Component Transfusion↗
PubMed2002

Mutagenicity of low-filtered 30 kVp X-rays, mammography X-rays and conventional X-rays in cultured mammalian cells.

PURPOSE: To measure the mutagenic effectiveness of low-filtered 30 kVp X-rays, mammography X-rays and conventional (200 kVp) X-rays in mammalian cells. MATERIALS AND METHODS: Two different cell lines and mutation assays were used. Exponentially growing SV40-transformed human fibroblasts were exposed to graded doses of mammography (29 kVp, tungsten anode, 50 microm Rh filter) or conventional X-rays and the frequency of 6-thioguanine-resistent HPRT-deficient mutants was determined. Exponentially growing hamster A(L) cells, which contain a single human chromosome 11 conferring the expression of the human surface protein CD59, were subjected to magnetic cell separation (MACS) in order to remove spontaneous mutants before irradiation with low-filtered 30 kVp (tungsten anode, 0.5 mm Al filter) or conventional X-rays. Fractions of radiation-induced CD59- mutants were quantified by flow-cytometry after immunofluorescence labelling of CD59 proteins. RESULTS: Mammography X-rays were more effective than conventional X-rays at inducing killing of human fibroblasts, whereas 30 kVp X-rays and conventional X-rays were about equally effective at killing Al. cells. Mutant frequencies were linearly related to dose in both mutation assays. An RBE = 2.7 was calculated for the yield of HPRT mutants in human fibroblasts exposed to mammography relative to conventional X-rays and an RBE = 2.4 was obtained for the CD59 mutant frequency in A(L) cells irradiated with low-filtered 30 kVp relative to conventional X-rays. CONCLUSIONS: Both low-filtered 30 kVp and mammography X-rays are mutagenic in mammalian cells in vitro. It is unknown if and how the enhanced mutagenicity of mammography X-rays measured in human cells in vitro translates into breast cancer risk for predisposed women with an enhanced inherited risk for breast cancer. Although the ICRP guidelines attribute the same relative biological effectiveness to all radiations of low LET, including X- and gamma-radiations of all energies for radiobiological protection purposes including the assessment of risks in general terms, they also state that 'for the estimation of the likely consequences of an exposure of a known population, it will sometimes be better to use absorbed dose and specific data relating to the relative biological effectiveness of the radiations concerned and the probability coefficients relating to the exposed population' (ICRP 1991: 32). This latter statement may apply for the population of familial predisposed women. We hope that the presented data on the enhanced mutagenicity of mammography X-rays may stimulate a re-evaluation of the risk assessment of mammography for familial predisposed women. In the meantime, one should be cautious and avoid early and frequent mammography exposure of predisposed women. Alternative examination methods should be applied for these women with an inherited increased risk for breast cancer.

Animals↗
PubMed2002

Mutation induction and neoplastic transformation in human and human-hamster hybrid cells: dependence on photon energy and modulation in the low-dose range.

Mutation induction in the HPRT gene of human fibroblasts after irradiation with mammography-like 29 kVp or 200 kVp x-rays shows radiohypersensitivity for doses smaller than approximately 0.5 Gy. Similarly, mutation induction in the CD 59 gene on human chromosome 11 in A(L) cells shows radiohypersensitivity for doses smaller than approximately 0.5 Gy after exposure to 200 kVp x-rays, but not after irradiation with low-filtered 30 kVp x-rays. The RBE values of 29 and 30 kVp x-rays relative to 200 kVp x-rays are strongly dose dependent. For neoplastic transformation of human hybrid (CGL1) cells after irradiation with 29 or 200 kVp x-rays or 60Co gamma rays a linear-quadratic dose relationship was observed with RBE values of approximately four and eight for mammography relative to 200 kVp x-rays and 60Co gamma rays, respectively.

Animals↗
PubMed2001

Immunoglobulin isotypes reveal a predominant role of type 1 immunity in multiple sclerosis.

IgG, its subclasses and IgE concentrations were measured in cerebrospinal fluid (CSF) and serum of multiple sclerosis (MS) patients and matched controls as surrogate markers for type 1 and type 2 immunity. IgE indices were significantly reduced in MS patients compared to controls. In contrast, IgG1 was elevated in CSF of MS patients and elevated indices indicated intrathecal synthesis. Because isotype switching to IgE and IgG4 is driven by type 2 immunity and occurrence of IgG1 has previously been found in type 1 immunity-dominated diseases, the results underscore a role of type 1 immunity in MS.

Adult↗
PubMed2001

Frequency of CD59 mutations induced in human-hamster hybrid A(L) cells by low-dose X-irradiation.

Determination of the genotoxic effects of ionizing radiation, especially at low-doses, is of great importance for risk assessment, e.g. in radiological diagnostics. The human-hamster hybrid A(L) cell line has been shown previously to be a well-suited in vitro model for the study of mutations induced by various mutagens. The A(L) cells contain a standard set of hamster chromosomes and a single human chromosome 11, which confers the expression of the human cell surface protein CD59. Using CD59 specific antibodies, cells mutated in the CD59 gene can be detected and quantified by the loss of the cell surface marker. In contrast to previous studies, prior to irradiation we removed spontaneous mutants by magnetic cell separation (MACS) which allows analysis of radiation-induced mutation events only. We exposed A(L) cells to 100kV X-rays at 0.1 to 5Gy. The proportions of X-irradiation-induced CD59(-) mutants were quantified by flow cytometry after immunofluorescence labeling. Between 0.2 and 5Gy the yield of CD59 mutants was a linear function of dose. The molecular analysis of individual CD59-negative clones induced after exposure of 1, 3 and 5Gy of X-ray revealed a dose-dependent linear increase of large deletions (>6Mbp), whereas, point mutations could be seen only in spontaneous CD59 mutants or after low-dose exposure (< or =1Gy). We conclude that the modified A(L) assay presented here is appropriate for detection and quantification of non-lethal DNA lesions induced by low-dose ionizing radiation.

Animals↗
PubMed2001

Retrospective clinical comparison of hemangioma treatment by flashlamp-pumped (585 nm) and frequency-doubled Nd:YAG (532 nm) lasers.

BACKGROUND AND OBJECTIVE: Laser therapy using the flashlamp-pumped pulsed dye laser (FPDL), along with contact cryotherapy, has proven to be an effective method with few side effects in the early treatment of superficial hemangiomas in infancy. The long-pulsed frequency-doubled Nd:YAG laser (VersaPulse) is a new kind of laser whose efficacy and safety we examined in direct comparison with the FPDL. STUDY DESIGN/MATERIALS AND METHODS: In a retrospective comparative study, we treated 50 infants with a total of 62 superficial hemangiomas. A total of 29 hemangiomas were treated with the FPDL (wavelength 585 nm, impulse duration 0.3-0.45 msec), 33 with the VersaPulse (wavelength 532 nm, impulse duration 1-50 msec). With an average of 3.0 and 2.6 treatments (FPDL/VersaPulse respectively), a cessation of growth or regressive tendency could be achieved in 93% and 70% of the hemangiomas, respectively. Complete regression occurred in 41% (FPDL) or 30% (VersaPulse). Only in 7% (FPDL) or 18% (VersaPulse) was there progression despite laser therapy. The side effect rates of both laser systems were low. CONCLUSION: The FPDL has proven to be the slightly more effective treatment method in comparison and, therefore, remains the therapy of choice for the initial treatment. If parents wish to pursue further treatment in the regression phase of hemangiomas to optimize the cosmetic appearance, we recommend the VersaPulse due to its low rates of side effects and painfulness.

Female↗
PubMed2001

Circumscripted pigmentations after iron injections-treatment with Q-switched laser systems.

BACKGROUND AND OBJECTIVE: Cutaneous brown discolorations in the area of injection can be a cosmetically bothersome side effect from a parenteral iron treatment, and have not responded to an effective therapy until now. STUDY DESIGN/PATIENTS AND METHODS: We report retrospectively on five patients who were treated with the Q-switched ruby and/or Nd:YAG laser for circumscripted siderosis after intramuscular or intravenous iron injection. RESULTS: The number of required laser treatments was between 3 and 16. The clinical improvement after the first 2-4 sessions was the most impressive, especially after the application of the Nd:YAG laser. Hypopigmentation and scars did not develop. In one case hyperpigmentation appeared. CONCLUSIONS: This study shows that there is an effective method of clearing persistent brown discolorations with few side effects after parenteral iron therapy, using Q-switched laser technology.

Adult↗
PubMed2001

Treating REM syndrome with the pulsed dye laser.

BACKGROUND AND OBJECTIVE: REM syndrome (reticular erythematous mucinosis) is a benign but bothersome skin disease that common occurs in middle age and among women. Local and systemic treatment measures are often associated with a high rate of side effects and relapses are common. We evaluated the pulsed dye laser as an alternative method because of its good efficacy in vascular skin diseases. STUDY DESIGN/MATERIALS AND METHODS: We treated two female patients with REM syndrome using the pulsed dye laser. RESULTS: In both patients the erythematous skin changes were almost completely removed after five and three laser sessions, respectively. Other than transient hypopigmentation, no side effects occurred. In one case there is still no evidence of recurrence 6 years after a trial treatment was conducted. In the same patient, clinical success was histologically confirmed. CONCLUSIONS: This is the first report on the successful treatment of REM syndrome of two female patients with the pulsed dye laser.

Adult↗