Suberythemal ultraviolet B radiation alters the expression of cell cycle-related proteins in the epidermis of human subjects without leading to photoprotection

BACKGROUND

Deregulation of the cell cycle proteins is one of the critical factors leading to cutaneous carcinogenesis.

OBJECTIVES

To monitor the expression of cell cycle proteins in the epidermis of subjects after repeated exposure to ultraviolet (UV) B radiation, and to test for the development of photoprotection by subsequent irradiation with a single erythemal UVB dose.

METHODS

A total of 26 healthy volunteers were divided into four groups: group 1 (n = 9) were given whole-body UVB irradiation for 10 consecutive days with 0.7 minimal erythema dose (MED), group 2 (n = 9) were irradiated as in group 1 followed 24 h later by a single UVB dose of 3 MED on buttock skin, group 3 (n = 4) were irradiated with a UVB dose of 3 MED on buttock skin, and group 4 (n = 4) were not irradiated. Skin biopsies were collected 24 h after the final irradiation and stained for cyclins A, B1, D1, and p16, p18, p21, p27, p53, pRB, Bax and Bcl-2.

RESULTS

The expression of cyclin D1, p18 and p21 was significantly higher in groups 1 and 2 compared with the nonirradiated group 4 controls and, in group 2, the expression of pRB, p53 and Bax was also increased. In group 3, only p53 and Bax proteins were significantly elevated compared with group 4. The expression of cyclin D1, p16, p18, p27, pRB and Bcl-2 was higher in group 2 compared with group 3.

CONCLUSIONS

Suberythemal UVB radiation was sufficient to cause changes in the expression of several epidermal cell cycle proteins. When tested by irradiation with a single erythemal UVB dose following the repeated exposures, no photoprotection against the UV-induced alteration in cell cycle protein expression was apparent.

Repeated low-dose ultraviolet (UV) B exposures of humans induce limited photoprotection against the immune effects of erythemal UVB radiation

BACKGROUND

Exposure of human subjects to ultraviolet (UV) B radiation causes immunosuppression. Most experiments to date have not tested the effects of low daily doses of UVB radiation.

OBJECTIVES

To ascertain whether photoprotection against several UV-induced immune effects might develop following repeated exposure.

METHODS

Groups of approximately 30 healthy individuals were given whole-body UVB irradiation on each of 10 consecutive days with 0.7 minimal erythema dose, or whole-body irradiation as before followed by a single erythemal UVB dose on a small body area, or irradiated only with a single erythemal UVB dose on a small body area, or were not irradiated. They were sensitized with diphenylcyclopropenone (DPCP) 24 h after the final dose, and skin biopsies collected to assess cytokine mRNA expression and the number of cells with thymine dimers and expression cyclooxygenase (COX)-1 and COX-2.

RESULTS

The contact hypersensitivity (CHS) response to DPCP was significantly lower in the three irradiated groups compared with the unirradiated controls, while cutaneous interleukin (IL)-1beta, IL-6, IL-10 and tumour necrosis factor-alpha mRNAs, COX-1 and COX-2 and thymine dimers were all significantly higher. When the single erythemal UVB dose was given following the repeated low exposures, a slight downregulation in cytokine expression and thymine dimer formation was indicated.

CONCLUSIONS

The repeated low doses of UVB protected to a limited extent against the effects of an erythemal UVB dose on cytokine expression and thymine dimer formation, but not on CHS or COX enzymes.

[The case of giant pleomorphic adenoma of the parotid gland with the malignancy features]

The aim of the study was showed the case of patient aged 41 years, treated in the Otolaryngology Department of Military Medical Academy because of giant pleomorphic adenoma of the parotid gland with the malignancy features. After performed of the BAC of tumour, the CT of neck and the scintigraphy of salivary glands the patient qualified for operation. The tumour resected with capsule and the superficial lobe of the left parotid gland, conservating of function of the facial nerve. The histopathologic examination proved the mucoepidermoid carcinoma in the pleomorphic adenoma didn't infiltrate of capsule. After oncologic consultation the patient had not of complementary radiotherapy, because the operation was radical and the carcinoma had a low radiosensitivity. The above mentioned case confirms of the reports, that the pleomorphic adenoma can undergo of malignancy changes, however the gigantic tumour doesn't write off possibility of operating success.

[A case of primary salpinx cancer--diagnostic difficulties]

In this paper the authors presents 55-years old female patient with primary carcinoma of salpinx. The special attention is payed to the possibility of clinical misdiagnosis. The low rate of appearance and not very characteristic symptoms of that type of carcinoma makes final clinical diagnosis almost impossible without intra-or postoperative histopathological study. In presented case, in the first acute appendicitis was recognized and patient was treated surgically. During the operation the large cyst near the right uterine appendages was found and after histopathological examination the primary salpinx carcinoma was revealed. In consequences pan hysterectomy was made with cytostatic all treatment just after the operation. Now, five years has gone and the patient, temporary controlled in dispensary, is still in good condition.