Localization and relaxation of singlet exciton formation in conjugated polymers under photoexcitation.

This paper employs a molecular dynamics approach to uncover the time profile of exciton formation, which can be divided into two stages: localization of electron-hole pairs and relaxation process (nuclear and electronic). Under photoexcitation, an electron-hole pair is formed by an electronic transition, and the pair in turn becomes localized through the electron-lattice interaction, which triggers the total energy to shift violently and oscillate. The oscillation during the first 40 fs induces the excitation to step into the second stage, i.

Lactate dehydrogenase 5 expression in melanoma increases with disease progression and is associated with expression of Bcl-XL and Mcl-1, but not Bcl-2 proteins.

The serum level of lactate dehydrogenase (LDH) is an important predictor of prognosis and treatment response in melanoma patients. It is unknown whether the expression of LDH-5 in tissue sections also has prognostic significance and whether it is related to the expression of the anti-apoptotic proteins, Bcl-2, Bcl-XL and Mcl-1, and endoplasmic reticulum stress protein glucose-regulated protein 78 (GRP78). Identification of an association between LDH-5 expression and anti-apoptotic proteins may have important therapeutic implications for melanoma patients.

Role and prognostic significance of tumor necrosis factor-related apoptosis-inducing ligand death receptor DR5 in nonsmall-cell lung cancer and precursor lesions.

Background: The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptor, DR5, mediates proapoptotic signals and is implicated in the pathogenesis of many neoplasms including nonsmall-cell lung cancer (NSCLC).

Methods: In this study, immunohistochemical expression of DR5 was examined in 146 cases of stage I and II NSCLC as well as neoplastic precursor lesions and regional lymph node metastases using tissue microarrays.

Results: High DR5 expression was observed in 67.

Mcl-1, Bcl-XL and Stat3 expression are associated with progression of melanoma whereas Bcl-2, AP-2 and MITF levels decrease during progression of melanoma.

Members of the Bcl-2 family of antiapoptotic proteins (Bcl-2, Bcl-XL and Mcl-1) are key regulators of apoptosis. The purpose of the present study was to examine and better define the role of Bcl-2, Bcl-XL and Mcl-1 in the progression of melanoma. Immunohistochemical staining for Bcl-2, Bcl-XL and Mcl-1 was performed on paraffin sections of 100 cases of benign nevi, primary melanoma and metastatic melanoma.

Progression in melanoma is associated with decreased expression of death receptors for tumor necrosis factor-related apoptosis-inducing ligand.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in melanoma by interaction with death receptors TRAIL-R1 (DR4) or TRAIL-R2 (DR5) on melanoma cells or resists apoptosis by interaction with decoy receptors TRAIL-R3 (DcR1) or TRAIL-R4 (DcR2). Studies on cell lines suggest that there is a wide variation in TRAIL death receptor expression; however, their expression on excised human melanoma is not well documented. In view of this, we studied death receptor expression on melanomas using monoclonal antibodies specific for these receptors.

The role of cell cycle regulatory proteins in the pathogenesis of melanoma.

The transformation of melanocytes to melanoma cells is characterised by abnormal proliferation resulting from alterations in cell cycle regulatory mechanisms. This occurs through alterations in the two major cell cycle regulatory pathways, the retinoblastoma (Rb) and p53 tumour suppressor pathways. This review summarises the current knowledge of alterations in these two pathways at G1/S transition and specifically the role of the key cell cycle regulatory proteins pRb, p16INK4a (p16), cyclin D1, p27Kip1 (p27), p53 and p21Waf1/Cip1 (p21) in the pathogenesis of melanoma.

[Nle4-D-Phe7]-alpha-melanocyte-stimulating hormone significantly increased pigmentation and decreased UV damage in fair-skinned Caucasian volunteers.

Epidermal melanin reduces some effects of UV radiation, the major cause of skin cancer. To examine whether induced melanin can provide protection from sunburn injury, 65 subjects completed a trial with the potent synthetic melanotropin, [Nle4-D-Phe7]-alpha-melanocyte-stimulating hormone ([Nle4-D-Phe7]-alpha-MSH) delivered by subcutaneous injection into the abdomen at 0.16 mg/kg for three 10-day cycles over 3 months.

Combined naevus: a benign lesion frequently misdiagnosed both clinically and pathologically as melanoma.

Background: Combined naevi are characterised pathologically by the presence of two or more different types of melanocytic naevi in a single lesion. They are prone to clinical and pathological misdiagnosis as melanoma. Misdiagnosis may result in inappropriate treatment, patient anxiety and medicolegal consequences.