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Biomedical subjects

R U Peter

Publications and source records attributed to R U Peter.

At least 55 records · Page 3Linked to original sources
PubMed2000

Cell-type-dependent induction of eotaxin and CCR3 by ionizing radiation.

Eotaxin is an eosinophil-specific C-C chemokine that is implicated in the pathogenesis of eosinophilic inflammatory diseases, such as asthma and atopic dermatitis, by acting specifically on its receptor CCR3. Using RT-PCR analysis, we show that the expression of eotaxin is upregulated upon treatment with ionizing radiation (IR) in human dermal fibroblasts, but not in the bronchial epithelial cell line A549. In contrast, the gene encoding CCR3 is markedly induced in both cell types. None of the genes coding for other CCR3 ligands are significantly induced by IR in these cell types. cDNA array analysis of irradiated versus nonirradiated A549 cells and human dermal fibroblasts confirm and extend these results, and support the observation that regulation of eotaxin/CCR3-induction by IR occurs in a selective and cell-type-dependent manner. They further suggest that the induction of signaling via eotaxin and CCR3 may be an important step leading to eosinophilia in patients with radiation exposure.

Base Sequence↗
PubMed2000

Detection of herpes simplex virus and varicella-zoster virus in clinical swabs: frequent inhibition of PCR as determined by internal controls.

BACKGROUND: PCR-based detection of microorganisms is widely used for diagnostic purposes. Most routine PCR applications do not control for inhibition of PCR, thus leading to false-negative results. METHODS AND RESULTS: One hundred eighteen swab samples obtained from skin and mucosa were investigated for the presence of herpes simplex virus (HSV), varicella-zoster virus (VZV), and the control gene betaglobin by internally controlled PCR with purified and unpurified DNA in parallel. With unpurified DNA, inhibition of PCR was detected in 23% of betaglobin PCRs, 25% of VZV PCRs, and 16% of HSV PCRs versus 3% each for purified DNA. Approximately 20% of the samples with positive results for HSV or VZV had negative or inhibited results using unpurified DNA. CONCLUSION: These results indicate that PCR from clinical swab specimens should be performed exclusively with internal controls because the positive control alone cannot exclude PCR inhibition in individual samples. Purification of DNA will decrease, but not exclude, PCR inhibition.

Conjunctiva↗
PubMed2000

[Sporotrichosis--fixed cutaneous and lymphocutaneous form].

Two patients were infected with sporotrichosis; one had the fixed cutaneous form, the other the lymphocutaneous form. Sporotrichosis schenckii was identified in both with a culture from a tissue biopsy. Both patients were successfully treated with itraconazole, one received 100 mg and the other 200 mg itraconazole daily over a 3 months period.

Adult↗
PubMed2000

[Cutaneous radiation syndrome: clinical features, diagnosis and therapy].

Accidental exposure to ionizing radiation may occur during such catastrophic events as the Chernobyl accident in 1986 or over days to weeks as in Goiania in 1987 and in the military camp during the training of soldiers in Lilo/Georgia in 1997, as well as in medical institutions. The cutaneous symptoms after radiation exposure are based on a combination of inflammatory processes and alteration of cellular proliferation as a result of a specific pattern of transcriptionally activated proinflammatory cytokines and growth factors. They follow a time course consisting of prodromal erythema, latency period, acute stage, chronic stage and late stage. The entire complex is referred to as cutaneous radiation syndrome. The time course depends on several factors such as the radiation dose, radiation quality, individual radiation sensitivity, the extent of contamination and absorption and amount of skin exposed. For the diagnosis of the cutaneous radiation syndrome the following procedures are used: 7.5 MHz to 20 MHz-B-scan sonography, thermography, capillary microscopy, profilometry, nuclear magnetic resonance imaging, bone scintigraphy and histology. Based on the results of experimental and clinical research, today treatment may include topical or systemic corticosteroids, gamma-interferon, pentoxifylline, vitamin E and superoxide dismutase. The treatment depends on the stage of the cutaneous radiation syndrome. Due to the complexity of the clinical manifestations of radiation disease, most patients require interdisciplinary treatment in specialized centres. Dermatologists are essential partners in the life-long follow-up and therapy of such patients.

Adrenal Cortex Hormones↗
PubMed2000

Antiapoptotic bcl-2 and bcl-xL in advanced malignant melanoma.

Apoptosis is an important cofactor in the pathogenesis of a plethora of malignancies. However, little is known about modulation of the expression of bcl gene family in melanocytic tumors. To determine the role of bcl-2, bcl-x and bax in melanocytic tumors we investigated the differential expression of these genes via RT-PCR in tissue samples from human benign nevi, primary melanomas and melanoma metastases in comparison with normal skin. Bcl-2 was strongly expressed in 14/16 metastases (87.5%), whereas only 7/13 primary melanomas (53%), 7/15 nevi (46%) and 7/16 normal tissue samples (43%) showed expression of bcl-2 (P < 0.05). There was a strong indication of a correlation between tumor thickness and bcl-2 expression in nodular malignant melanomas. Expression of bcl-x was found in 16/16 melanoma metastases (100%), 11/13 primary melanomas (84%), 12/15 nevi (80%) and 10/16 normal tissue samples (62%) (P < 0.05). Bcl-xL expression increased from primary melanoma to melanoma metastases, whereas bcl-xS showed a decreasing expression level during melanoma progression. No differences in bax expression were seen between melanoma metastases, primary melanoma, nevi and normal tissue. Immunohistochemical investigations of another 53 tissue samples showed similar results. Our results strongly indicate that bcl-2 and bcl-xL gene expression increases with progression of malignant melanoma. Bcl-2 and bcl-xL expression could reflect an increased malignant potential caused by an inhibition of apoptosis and growth advantage for metastatic melanoma cells.

Apoptosis↗
PubMed2000

Lymph node dissection in cutaneous melanoma: surgical and oncological implications.

The concept of Sentinel Lymph Node Dissection (SLND) has strongly influenced the surgical approach towards primary melanoma in the last decade. Initiated by the disappointing results of elective lymph node dissection (ELND) in this malignancy, the concept of analyzing the first draining lymph node (Sentinel) of a regional basin was developed as a diagnostic means to avoid unnecessary ELND in case of negative SLNs. According to recent standards detection of the SLN should be performed by a triple approach: injection of 90 nm Technetium and patent blue in the periphery of the primary melanoma, and intraoperative tracing of radioactivity with the aid of a hand-held gamma probe. Histopathological examination of alternating series sections of the whole lymph node appears to be the best analytic approach. Molecular biologic procedures such as tyrosinase RT-PCR are time-consuming to perform and produce contradictory results. SLND for cutaneous melanoma is an interdisciplinary diagnostic approach involving surgery, dermatology, pathology, and nuclear medicine. In spite of a variety of published promising results derived from clinical trials ranging from a few dozens to several hundred included patients the diagnostic and prognostic value of SLND remains to be confirmed by ongoing controlled prospective clinical trials. At this stage, SLND can by no means be considered a therapeutic procedure. These aspects have to be kept in mind when informed consent is obtained from patients as well as in the individual determination of the risk-benefit ratio.

Clinical Trials as Topic↗
PubMed2000

Chronic sclerodermic graft-versus-host disease refractory to immunosuppressive treatment responds to UVA1 phototherapy.

Graft-versus-host disease is a frequent complication of allogenic bone marrow transplantation. Approximately 10% of patients suffering from chronic graft-versus-host disease develop sclerodermic graft-versus-host disease of the skin, which often does not respond to conventional immunosuppressive therapy. An alternative to immunosuppressive treatment is photochemotherapy. We describe a patient with chronic sclerodermic graft-versus-host disease who did not respond to a combination therapy of cyclosporine and prednisone and later mycophenolate mofetil plus prednisone. A combination therapy of mycophenolate mofetil (2 g/day) and low-dose UVA(1) therapy (single dose, 20 J/cm(2), 4 times per week over 6 weeks) resulted in striking clinical improvement of sclerodermic graft-versus-host disease.

Adult↗
PubMed2000

The radiation accident in Georgia: clinical appearance and diagnosis of cutaneous radiation syndrome.

BACKGROUND: Eleven male Georgian soldiers were accidentally exposed to radiation by cesium 137 during their training in a military exercise camp in Lilo, Georgia between November 1996 and May 1997. OBJECTIVE: The characteristic sequelae of accidental cutaneous irradiation and available diagnostic methods are described. METHODS: Magnetic resonance imaging (MRI) of radiation ulcers was performed in all patients; thermography was performed in 2. In 7 patients ulcers and white macules were examined with high-frequency 20 MHz sonography; histologic results were obtained from all patients. RESULTS: Predominant lesions were radiation ulcers in 11 patients and white hairless macules in 7. MRI showed ulcers down to the muscles and an increase of signal intensity in the musculature in 9 cases. The corresponding muscle histology demonstrated vasculitis in 7 patients and necrosis in 2. In 2 patients, MRI signal intensity of the musculature was normal. In 3 patients, 20 MHz sonography showed dermal defects; 1 patient had cutaneous fibrosis. Thermography demonstrated hypothermic zones with extended inflammatory zones adjacent to the radiation ulcers in both patients examined. CONCLUSION: High-frequency 20 MHz sonography, MRI, and thermography are useful noninvasive methods for diagnosis of the extent of cutaneous radiation syndrome and for therapy planning.

Adult↗
PubMed2000

Combination phototherapy of psoriasis with narrow-band UVB irradiation and topical tazarotene gel.

BACKGROUND: Narrow-band UVB (311 nm) phototherapy offering an emission spectrum closely conforming to the peak of the action spectrum for clearing psoriasis has significantly improved phototherapy for psoriasis. Because the majority of the commonly used topical therapies in treatment of psoriasis have limitations, a need for new topical agents remains. Tazarotene has been shown to be efficacious in plaque-type psoriasis. Combination of narrow-band UVB with topical agents has been shown to enhance efficacy of both treatment modalities. OBJECTIVE: We attempted to evaluate the efficacy of narrow-band UVB phototherapy in combination with topical tazarotene. METHODS: Ten patients with stable plaque psoriasis were treated with narrow-band UVB. In addition, topical tazarotene 0.05% was applied once daily to one side of the body. The follow-up period was 4 weeks. Efficacy was assessed separately for both body halves by means of a modified Psoriasis Area and Severity Index (PASI). RESULTS: Both treatment modalities notably reduced the PASI scores with values being significantly lower in skin areas treated with narrow-band UVB phototherapy in combination with topical tazarotene. CONCLUSION: The addition of tazarotene to narrow-band UVB phototherapy promotes more effective, faster clearing of psoriasis compared with UVB (311 nm) monotherapy.

Administration, Cutaneous↗
PubMed2000

Assessment of minimal phototoxic dose following 8-methoxypsoralen bath: maximal reaction on average after 5 days.

An essential procedure before starting bath psoralen ultraviolet (UV) A (PUVA) photochemotherapy is the evaluation of the minimal phototoxic dose (MPD), which is traditionally assessed 3 days after irradiation. However, there are no controlled studies supporting the 72 h peak of bath-PUVA erythema. The aim of this study was therefore to determine the exact time course of the erythematous reaction in human skin following bath-PUVA. For this purpose, the skin of 10 volunteers was exposed to 0.5-3.0 J/cm2 UVA directly after a 20-min 8-methoxypsoralen bath (0.5 mg/L, 37 degrees C). At 24, 48, 72, 96, 120 and 144 h (1-6 days) after irradiation, the MPD and the erythema sum score (ESS) were determined in each subject. The results showed a maximal erythematous reaction on average 5 days after irradiation. The mean MPD gradually decreased from day 2 (> 3.0 J/cm2) to day 5 (mean +/- SD 1.15 +/- 0.63 J/cm2) and started to increase at day 6 (mean +/- SD 1.6 +/- 0.52 J/cm2). The mean +/- SD ESS correspondingly increased from day 2 (0 +/- 0) to day 5 (10.5 +/- 3. 7) with a decrease at day 6 (7.5 +/- 3.1) (difference between day 3 and beyond statistically significant at P < 0.05). As our study indicates a maximal erythematous reaction to the bath-PUVA up to 5 days after irradiation, the traditional MPD assessment at 3 days generates a risk of phototoxic side-effects within the phototherapy course by underestimating the phototoxic effect in some patients. These findings contribute towards a more defined understanding of the kinetics of the phototoxic reaction in bath-PUVA therapy.

Adult↗
PubMed2000

Eosinophilic fasciitis treated with psoralen-ultraviolet A bath photochemotherapy.

Eosinophilic fasciitis is a rare disorder which can markedly affect the quality of life in individual patients. So far, no generally accepted and effective treatment modality has been available. Although the precise nature of eosinophilic fasciitis is still unknown, it is often regarded as a variant of localized scleroderma (morphoea). Phototherapy and photochemotherapy have been shown to be effective in the treatment of sclerodermatous skin lesions. We report a patient with eosinophilic fasciitis which was successfully treated with psoralen plus ultraviolet A bath photochemotherapy within 6 months.

Eosinophilia↗
PubMed2000

Trauma and melanoma formation: a true association?

BACKGROUND: Little is known about the role of mechanical trauma in the pathogenesis of malignant melanoma. In individual patients, traumatic events have been discussed as a causative factor for the induction of melanoma and diagnosis of melanoma following trauma may raise medico-legal questions. OBJECTIVES: To evaluate the relationship between traumatic single or recurrent events and melanoma characteristics. METHODS: Retrospective questionnaire in 369 melanoma patients. RESULTS: A large number of patients (337 of 369; 91.3%) denied an association between a possible traumatic event and melanoma formation. Thirty-two of 369 patients (8.7%) considered an association of trauma and melanoma formation likely. Of these 32 patients, 22 patients (13 men, nine women) reported a single event, and 10 patients (four men, six women) a persisting irritation. An irritation of a pre-existing melanocytic naevus was reported by two patients with histologically confirmed melanoma on acquired or congenital naevus. CONCLUSIONS: As most of the patients who mentioned a trauma in this study suffered from acral melanoma, or melanoma located on the extremities, a history of trauma should be expected more frequently at these body sites. A review of epidemiological, clinical and scientific research indicates that there seems to be no evidence for single or persistent traumatic events as a causative factor for melanoma formation.

Adolescent↗
PubMed2000

Calcipotriol vs. tazarotene as combination therapy with narrowband ultraviolet B (311 nm): efficacy in patients with severe psoriasis.

BACKGROUND: Phototherapy has been shown to be one of the most effective treatment modalities for patients with psoriasis. Nevertheless, photocombination therapies capable both of reducing cumulative ultraviolet (UV) doses and of accelerating clearance of skin lesions are important and of high interest. There have been no published studies comparing the effect of narrowband UVB irradiation in combination with topical application of tazarotene vs. calcipotriol. OBJECTIVES: To determine, in a half-side manner, whether a combination of UVB (311 nm) and tazarotene is superior to UVB (311 nm) plus calcipotriol or vice versa. METHODS: Ten patients suffering from widespread symmetrical psoriasis were treated for at least 4 weeks with topical calcipotriol and tazarotene in a half-side distribution. Additionally, the whole body was irradiated with narrowband UVB (311 nm) four times a week. Before treatment and once weekly during therapy a modified Psoriasis Area and Severity Index was estimated for each body half. The total treatment time, number of treatment sessions and cumulative UVB dose necessary for clearance of skin lesions were determined in an observer-blind fashion for each patient. Furthermore, all patients completed a quality of life questionnaire. RESULTS: Clearance of psoriasis was observed after a median of 19 treatment sessions (range 14-28) and a median cumulative UVB dose of 22.98 J cm-2 (range 9.24-58.22) simultaneously for both body halves. On the side treated with topical tazarotene gel, four patients complained of itching and dryness of the skin, and skin irritation was observed in three of them. Six patients preferred the application of tazarotene gel, while four preferred calcipotriol. CONCLUSIONS: Our clinical comparison of narrowband UVB with either topical calcipotriol or topical tazarotene revealed no significant therapeutic difference between both regimens. Although these results need to be confirmed in larger patient groups, we feel that both photocombination therapies can broaden the therapeutic options for moderate to severe psoriasis vulgaris and may reduce the cumulative UVB dose during therapy.

Administration, Topical↗