A liquid metal-polydopamine composite for cell culture and electro-stimulation.

Gallium (Ga) is a low melting point metal in the liquid state in the biological environment which presents a unique combination of fluidity, softness, and metallic electrical and thermal properties. In this work, liquid Ga is proposed as a biocompatible electrode material for cell culture by electro-stimulation since the cytotoxicity of Ga is generally considered low and some Ga compounds have been reported to exhibit anti-bacterial and anti-inflammatory activities. Complementarily, polydopamine (PDA) was coated on liquid Ga to increase the attachment capability of cells on the liquid Ga electrode and provide enhanced biocompatibility. The liquid Ga layer could be readily painted at room temperature on a solid inert substrate, followed by the formation of a nanoscale PDA coating layer resulting in a conformable and biocompatible composite electrode. The PDA layer was shown to coordinate with Ga3+, which is sourced from liquid Ga, providing electrical conductivity in the cell culture medium. The PDA-Ga3+ composite acted as a conductive substrate for advanced electro-stimulation for cell culture methods of representative animal fibroblasts. The cell proliferation was observed to increase by ∼143% as compared to a standard glass coverslip at a low potential of 0.1 V of direct coupling stimulation. This novel PDA-Ga3+ composite has potential applications in cell culture and regenerative medicine.

Gut Commensal E. coli Proteins Activate Host Satiety Pathways following Nutrient-Induced Bacterial Growth.

The composition of gut microbiota has been associated with host metabolic phenotypes, but it is not known if gut bacteria may influence host appetite. Here we show that regular nutrient provision stabilizes exponential growth of E. coli, with the stationary phase occurring 20 min after nutrient supply accompanied by bacterial proteome changes, suggesting involvement of bacterial proteins in host satiety. Indeed, intestinal infusions of E. coli stationary phase proteins increased plasma PYY and their intraperitoneal injections suppressed acutely food intake and activated c-Fos in hypothalamic POMC neurons, while their repeated administrations reduced meal size. ClpB, a bacterial protein mimetic of α-MSH, was upregulated in the E. coli stationary phase, was detected in plasma proportional to ClpB DNA in feces, and stimulated firing rate of hypothalamic POMC neurons. Thus, these data show that bacterial proteins produced after nutrient-induced E. coli growth may signal meal termination. Furthermore, continuous exposure to E. coli proteins may influence long-term meal pattern.

The number of preproghrelin mRNA expressing cells is increased in mice with activity-based anorexia.

Plasma levels of ghrelin, an orexigenic peptide, are increased during conditions of chronic starvation, such as in patients with anorexia nervosa. However, it is not known whether such increase can be related to the number of preproghrelin mRNA-expressing cells in the stomach, and if chronic starvation may activate a tentative central ghrelin production. In this work, in situ hybridization technique was used to analyze the presence and number of preproghrelin mRNA-expressing cells in the stomach and the hypothalamus of mice with activity-based anorexia (ABA) induced by the combination of running wheel activity with progressive, during 10 days, feeding-time restriction (FTR) and compared with sedentary FTR, ABA pair-fed (PF) and ad libitum-fed control mice. All food-restricted mice lost more than 20% of body weight. Body weight loss was similar in ABA and PF mice, but it was more pronounced than in FTR mice. Food intake was also lower in ABA than in FTR mice. Preproghrelin mRNA-expressing cells in the stomach were increased proportionally to the body weight loss in all food-restricted groups with the highest number in ABA mice. No preproghrelin mRNA-producing cells were detectable in the hypothalamus of either control or food-restricted mice. Thus, the increased number of gastric preproghrelin mRNA-producing cells during chronic starvation proportionally to the body weight loss and reduced food intake may underlie increased plasma ghrelin. Hyperactivity-induced anorexia appears to further increase the number of preproghrelin mRNA-producing cells in the stomach. No evidence was found for ghrelin expression in the hypothalamus, not even in any of the present experimental models.

Probiotic Lactobacillus acidophilus and L. casei mix sensitize colorectal tumoral cells to 5-fluorouracil-induced apoptosis.

To assess the potential of Lactobacillus acidophilus and Lactobacillus casei strains to increase the apoptosis of a colorectal cancer cell line in the presence of 5-fluorouracil (5-FU), LS513 colorectal cancer cells were treated for 48 h with increasing concentrations of these lactic acid bacteria (LAB) in the presence of 100 mu g/ml of 5-FU. In the presence of 10(8) CFU/ml of live LAB, the apoptotic efficacy of the 5-FU increased by 40%, and the phenomenon was dose dependent. Moreover, irradiation-inactivated LAB caused the same level of induction, whereas microwave-inactivated LAB reduced the apoptotic capacity of the 5-FU. When cells were treated with a combination of live LAB and 5-FU, a faster activation of caspase-3 protein was observed, and the p21 protein seems to be downregulated. These results suggest that live L. acidophilus and L. casei are able to increase the apoptosis-induction capacity of 5-FU. The mechanisms of action are still not elucidated, and more research is needed to understand them. This is the first set of experiments demonstrating that some strains of LAB can enhance the apoptosis-induction capacity of the 5-FU. Based on these results, it is possible to speculate that LAB or probiotics could be used as an adjuvant treatment during anticancer chemotherapy.

[Levator ani syndrome, functional intestinal disorders and articular abnormalities of the pelvis, the place of osteopathic treatment]. / Syndrome des releveurs de l'anus, troubles fonctionnels intestinaux et anomalies articulaires du petit bassin, place du traitement ostéopathique.

OBJECTIVES: Various treatments of the Levator ani syndrome (LVAS) have been proposed. None of them alleviate symptoms in more than 20% of the cases. A new approach combining massages of the coccygeus muscle with physical treatment of frequently associated pelvic joint disorders was assessed. The outcome of the Irritable Bowel Syndrome (IBS) that is frequently associated was also studied. METHODS: One hundred and one patients (76 females and 25 males, mean age: 54 years) with a diagnosis of LVAS were studied prospectively over one year. Massages were given with a patient lying on the left side. Physical treatment of the pelvic joint disorders was given at the end of each massage session. RESULTS: Forty-seven patients (46.5%) suffered both from LVAS and IBS. A mean of less than 2 sessions of treatment was necessary. Sixty-nine per cent of the patients were LVAS-free at 6 months (p<0.0001) and 10% were improved. At 12 months, 62% were still free of symptoms and 10% improved (p=0.37). A comparable trend according to the Rome II criteria was found in the IBS-patient group (53% IBS free initially, 78% at 6 months [p=0.00001], 72% at 12 months [p=1]). There was a significant correlation between the favorable outcome of IBS and the LVAS at 6 and 12 months. All IBS-free patients were LVAS-free at 6 months. CONCLUSION: The LVAS may be cured or alleviated in 72% of the cases at 12 months with one to 2 sessions. This new comprehensive treatment suggests the role of a muscular and osteoligamentary etiology in the LVAS. Since most of IBS benefitted from such treament, it is logical to suspect a mutual pathogeny and to screen for LVAS in all such patients.