Enhancement of adipogenesis induction by conditioned media obtained from cancer cells.

White adipose tissue is a multifunctional endocrine organ that synthesizes and secretes cytokine-like proteins termed adipokines. In the present study, the effects of cancer-derived medium on adipogenesis were examined. We prepared conditioned media from cancer cell lines, and cultured preadipocytes in the conditioned media. After 10 days of culture, intracellular lipid droplet accumulation was measured. We observed that the conditioned media significantly induced adipogenesis or enhanced the adipogenesis induced by adipogenesis inducers. Although we could not define the factors, these undefined factors derived from cancer cells may induce adipogenesis, and the resulting adipogenesis may affect cancer development.

Formation of 8-hydroxy-2'-deoxyguanosine in the DNA of cultured human keratinocytes by clinically used doses of narrowband and broadband ultraviolet B and psoralen plus ultraviolet A.

Psoralen plus ultraviolet A (PUVA) and narrowband ultraviolet B (UVB) are widely used in skin disease phototherapy. Recently, the efficacy of UVB therapy has been greatly improved by narrowband UVB, compared to conventional broadband UVB. The objectives of the current study were to evaluate the influence of UVB-induced and PUVA-induced oxidative stress on cultured keratinocytes. We analyzed 8-hydroxy-2'-deoxyguanosine (8-OH-dG) in human keratinocytes (HaCaT cell line) using a high-performance liquid chromatography system equipped with an electrochemical detector. Non-irradiated human keratinocytes contained a baseline of 1.48 +/- 0.22 (mean +/- SD) 8-OH-dG per 10(6) deoxyguanosine (dG) residues in cellular DNA, which increased linearly with higher doses of UVB. When their abilities to induce 8-OH-dG were compared to each other, based on the minimal erythemal and therapeutically used doses, by irradiating them with broadband UVB at 100 mJ/cm(2), the amount of 8-OH-dG increased to 3.42 +/- 0.46 residues per 10(6) dG, while a narrowband UVB treatment at 1000 mJ/cm(2), with biological effects comparable to those elicited by 100 mJ/cm(2) broadband UVB, increased it to 2.06 +/- 0.31 residues per 10(6) dG. PUVA treatment, with 100 ng/mL 8-methoxypsoralen and 5000 mJ/cm(2) UVA, increased the 8-OH-dG level to 4.52 +/- 0.42 residues per 10(6) dG. When HaCaT cells treated with 2000 mJ/cm(2) narrowband UVB were cultured and the amount of 8-OH-dG was monitored in the living cells, 65.6% of the residues were repaired 24 h after treatment. Our study provides a warning that widely used narrowband UVB and PUVA induce cellular oxidative DNA damage at the therapeutically used doses, although to a lesser degree than broadband UVB with the same clinically effective dose.

Analysis of 8-hydroxyguanine (8-OH-Gua) released from DNA by the formamidopyrimidine DNA glycosylase (Fpg) protein: a reliable method to estimate cellular oxidative stress.

To improve the analyses of a form of oxidative DNA damage, 8-hydroxyguanine (8-OH-Gua), we treated isolated DNA with formamidopyrimidine DNA glycosylase (Fpg) and analyzed the released 8-OH-Gua by using a high-performance liquid chromatography system equipped with an electrochemical detector (HPLC-ECD). The human lung carcinoma cells (A549) and human keratinocyte (HaCaT) were irradiated with gamma-rays. After the isolated DNA was treated with the Fpg protein, we analyzed the released 8-OH-Gua by using an HPLC-ECD. With this method, the background level of 8-OH-Gua in DNA from human lung carcinoma cells was determined to be 3.4 residues per 10(7) guanine (Gua). A similar background level of 8-OH-Gua (3.1 residues per 10(7) Gua) was also detected in human keratinocyte DNA with this method. These background 8-OH-Gua levels in cellular DNA are comparable to that obtained previously by an analysis of 8-OH-dGMP after nuclease P1 digestion of cellular DNA (4.3 residues per 10(7) dCMP). A dose-dependent increase of 8-OH-Gua (0.17/10(7) Gua/Gy) was observed after cells were irradiated with gamma-rays. Twenty hours after gamma-irradiation with 60 Gy, 75% of the 8-OH-Gua produced in keratinocyte DNA was repaired. With our new analysis method, it is possible to detect the small changes in the 8-OH-Gua levels in cellular DNA induced by various environmental factors.

Detection of a mouse OGG1 fragment during caspase-dependent apoptosis: oxidative DNA damage and apoptosis.

We investigated the expression of mouse 8-oxoguanine DNA glycosylase 1 (mOGG1) in mouse non-parenchymal hepatocytes (NCTC) during etoposide- or mitomycin C (MMC)-induced apoptosis. We observed mOGG1 fragmentation in apoptotic cells. The apoptosis accompanying the fragmentation of mOGG1 was caspase-dependent. The mOGG1 fragment existed in both the cytoplasm and nucleus of the etoposide-treated NCTC, indicating that the mOGG1 fragment could be transferred into the nucleus. In addition, 8-hydroxyguanine (8-OH-Gua, 7,8-dihydro-8-oxoguanine) accumulated in the DNA of NCTC treated with etoposide, suggesting that the mOGG1 fragment might not function as a normal repair enzyme in etoposide-treated NCTC. Although we have not clarified in detail the mechanism and the significance of the mOGG1 fragmentation, further study of the fragmentation of DNA repair enzymes might provide insights into the relationship between oxidative DNA damage and apoptosis.

[Four cases of non-clostridial gas gangrene with diabetes mellitus].

We report four cases of non-clostridial gas gangrene. All cases were associated with diabetes mellitus as the underlying disease. Case 1: a 60-year-old male developed an ulcerative lesion on the dorsum of his left foot. Peptostreptococcus asaccharolyticus, Citrobacter freundii and Staphyrococcus epidermidis were identified in culture from odoriferous pus. Case 2: a 81-year-old female developed a lesion on her vulva spreading to the right lower abdomen. Bacteroides bivius, Peptostreptococcus asaccharolyticus and Streptococcus faecalis were identified in culture of the odoriferous pus. Case 3: a 80-year-old male developed a swollen area with ulcer on the right foot. Bacteroides fragiris, Enterococcus faecalis, Proteus mirabilis, Enterococcus avium and Enterococcus faecalis were identified by culture. Case 4: a 52-year-old female developed swelling of her left groin. Enterococcus faecalis and Streptococcus anginosus were identified in culture from the odoriferous pus. In all patients, a radiological examination revealed the presence of subcutaneous gas in the lesion. Prognosis of non-clostridial gas gangrene is usually poor. These four patients, however, all survived. Once an infectious sign is seen in the diabetic patient, it is important to discover a gas figure by using the radiological examination (plain film or computed tomography). Earlier diagnosis and debridement are the most important for a better prognosis. Because workers with diabetes mellitus are now increasing in number, occupational physicians should always keep in mind that a serious infectious disease like non-clostridial gas gangrene can develop even from minor accidental trauma, and they should control the working environment in the workplace where accidents often happen.