Dual actions of the antioxidant chlorophyllin,a glutathione transferase P1-1 inhibitor,in tumorigenesis and tumor progression

Glutathione (GSH) and enzymes related to this antioxidant molecule are often overexpressed in tumor cells and may contribute to drug resistance. Blockade of glutathione transferases (GSTs) has been proposed to potentiate the efficacy of chemotherapeutic drugs in cancer. The aim of this study was to evaluate the effect of chlorophyllin that has antioxidant properties, and also interferes with the activity of GST P1-1, on breast cancers in vitro and in vivo. The in vivo studies were conducted using an N-methyl- N-nitrosourea (MNU)-induced chemical carcinogenesis model in laboratory rats. DNA damage, GST activity, and GSH levels were determined in liver and tumor tissues. Treatment with chlorophyllin increased the GSH levels in the liver and significantly decreased DNA damage in the blood, liver, and tumor tissues. Even though tumorigenesis was delayed in rats receiving chlorophyllin before MNU injections, once the tumors emerged, the progression of tumor appeared to be faster than in the animals that received the carcinogen only. Out of nine breast cell lines, GST P1-1 expression was detected in MCF-12A, MDA-MB-231, and HCC38. Concomitant incubation with chlorophyllin and docetaxel did not significantly affect cell proliferation and viability. Chlorophyllin displayed genoprotective effects that initially delayed tumorigenesis. However, once the tumors were established, it may act as a promoter that facilitates tumor growth, potentially by a mechanism independent of cell proliferation and viability. Our results underline the pros and cons of antioxidant treatment in cancer, even if it has a capacity to inhibit GST P1-1.     

A comparison of complication rates in large and small inferior pedicle reduction mammaplasty

The main objective of this retrospective study was to determine whether the rates of complications are higher in large reductions (> or =1000 g per breast) as compared with smaller reductions (< or =999 g per breast) using the inferior pedicle technique. A retrospective chart review of 133 consecutive patients operated on between October of 2000 and March of 2002 was undertaken. Complication data were recorded and analyzed on a per-breast basis. Two hundred sixteen breasts had reductions of 999 g or less, whereas 50 breasts had reductions of 1000 g or more. The overall mean follow-up period was 152 days (range, 20 to 522 days). There were no statistically significant differences in the rates of nipple necrosis, hematoma formation, seroma, delayed healing, culture-positive wound infection, fat necrosis, cyst formation, nipple sensation, or hypertrophic scarring between the large and small reductions. However, the rate of wound dehiscence was significantly lower in the smaller reduction group. The rates of wound dehiscence and hypertrophic scarring were also significantly lower in patients who had received at least 5 days of postoperative antibiotics. A statistically significant difference was also reported for clinical wound infection (p < 0.0005). Body mass index had no statistically significant effect on the rate of nipple necrosis, hematoma formation, fat necrosis, cyst formation, nipple sensation, or hypertrophic scarring. However, body mass index had a statistically significant effect on delayed healing, wound dehiscence, and culture-positive wound infection. A higher mean body mass index predicted a delayed healing, wound dehiscence, and infection. The inferior pedicle technique is a safe method of breast reduction regardless of degree of parenchymal resection. However, the use of postoperative antibiotics for at least 5 days is recommended to reduce rates of wound dehiscence and improve postoperative scarring.     

The Effect of 3′,4′-Dihydroxyflavonol on Lipid Peroxidation in Rats with Cerebral Ischemia Reperfusion Injury

Neurochemical Research - The aim of present study was to determine the effect of 3′,4′-dihydroxyflavonol (DiOHF) on lipid peroxidation in experimental brain ischemia–reperfusion...     

Dynamic co‐culture metabolic models reveal the fermentation dynamics,metabolic capacities and interplays of cheese starter cultures

In this study, we have investigated the cheese starter culture as a microbial community through a question: can the metabolic behaviour of a co‐culture be explained by the characterized individual organism that constituted the co‐culture? To address this question, the dairy‐origin lactic acid bacteria Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis, Streptococcus thermophilus and Leuconostoc mesenteroides, commonly used in cheese starter cultures, were grown in pure and four different co‐cultures. We used a dynamic metabolic modelling approach based on the integration of the genome‐scale metabolic networks of the involved organisms to simulate the co‐cultures. The strain‐specific kinetic parameters of dynamic models were estimated using the pure culture experiments and they were subsequently applied to co‐culture models. Biomass, carbon source, lactic acid and most of the amino acid concentration profiles simulated by the co‐culture models fit closely to the experimental results and the co‐culture models explained the mechanisms behind the dynamic microbial abundance. We then applied the co‐culture models to estimate further information on the co‐cultures that could not be obtained by the experimental method used. This includes estimation of the profile of various metabolites in the co‐culture medium such as flavour compounds produced and the individual organism level metabolic exchange flux profiles, which revealed the potential metabolic interactions between organisms in the co‐cultures.     

Cutting edge: dissociation between autoimmune response and clinical disease after vaccination with dendritic cells

Autoimmunity represents a caveat to the use of dendritic cells (DCs) as adjuvant for human vaccines. We derived DCs from normal BALB/c mice or from mice prone to autoimmunity (NZB x NZW) F(1). We allowed DCs to phagocytose apoptotic thymocytes and vaccinated syngeneic animals. All mice developed anti-nuclear and anti-dsDNA Abs. Autoantibodies in normal mice were transient, without clinical or histological features of autoimmunity or tissue involvement. In contrast, autoimmunity was maintained in susceptible mice, which underwent renal failure and precociously died. The data suggest that DC vaccination consistently triggers autoimmune responses. However, clinical autoimmunity develops in susceptible subjects only.     

Comparative analysis of the effects of chitosan and common plant growth regulators on <Emphasis Type="Italic">in vitro</Emphasis> propagation of <Emphasis Type="Italic">Ipomoea purpurea</Emphasis> (L.) Roth from nodal explants

This study aimed to evaluate the effects of partially N-acetylated chitosans with a degree of acetylation (DA) of 10% on in vitro propagation of an ornamental plant, Ipomoea purpurea, by emphasizing the importance of the degree of polymerization (DP) on in vitro plant development. The effects of either a chitosan oligomer mixture with a DP between 2 and 15 (5.0, 10.0, and 20.0 mg L^?1) or chitosan polymer with a DP of 70 were compared with commonly used cytokinins [6-benzylaminopurine (BAP) and kinetin (KIN) at 0.5, 1.0, 2.0, and 4.0 mg L^?1] and auxins [indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) at 0.25, 0.5, 1.0, and 2.0 mg L^?1]. The nodal explants used in this study were taken from donor plants obtained by germination of the seeds. The results indicated that all chitosan treatments had positive effects on the shoot induction, but only the oligomer mixture at 5 mg L^?1 gave the best results for mean shoot number, shoot length, and leaf number, compared to the other treatments and control. Also, all chitosan treatments increased mean number of roots and triggered adventitious root induction. However, root elongation was decreased in the presence of chitosan in the medium. The root elongation-inhibitory effects of chitosan become clearer in the presence of oligomer mixture. In general, chitosan had similar effects with tested cytokinins rather than auxins. The results of this study suggested that the application of chitosan oligomers—rather than polymers—can be an eco-friendly and effective alternative to synthetic cytokinins in horticulture.     

The expression of fragile X chromosomes in members of the same family at different times of examination

Summary Three brothers with fragile X chromosomes were repeatedly examined using the same culture and preparation techniques. It was observed that a given individual showed a very constant frequency of fragile sites at his X chromosomes, whereas large differences in the the fragile X counts occurred between the three brothers.     

Effect of cold adaptation on total enzyme activities of L cells

Using cytochemical methods, the authors tested enzymatic reactions in L-As and L-C3 cells. They found that esterase activity in particular, but also several other enzyme activities, were higher in L-C3 cells than in L-As cells. This furnished further evidence of the raised metabolic activity of the cold-resistant cell subline L-C3 compared with the L-As line.