Human ovarian tissue from cortex surrounding benign cysts: a model to study ovarian tissue cryopreservation

BACKGROUND: The scarcity of human ovarian tissue is a major problem in developing research on ovarian cryopreservation. We were interested in ovarian cortex surrounding benign ovarian cysts harvested during their requisite operations. METHODS: Ovarian tissue was collected from 25 women (mean age = 27.7 +/- 1.0 SEM) and frozen in serum-free cryoprotective medium. Histological and viability analysis were performed on fresh and frozen-thawed slices of tissue. RESULTS: Dermoid (n = 7), endometriosis (n = 13) and serous (n = 5) cysts were observed. Follicular densities (expressed per mm3) in ovarian cortex surrounding dermoid cysts were higher than in endometriosis and serous cysts for both histological (median of follicular densities: 13.04, 0.31 and 0.89 respectively) and viability analysis (2.93, 0.05 and 0.71 respectively). Freezing-thawing did not result in gross abnormality of follicle population either in number or morphology (80% of follicles preserved a normal pattern). However, a slight decrease of the density of living follicles (expressed per mm2) was reported. CONCLUSIONS: Ovarian cortex surrounding ovarian cysts, especially dermoid cysts, could be considered a source of ovarian tissue for future research. In our study, the cryopreservation procedure resulted in high follicular survival assessed by both histological and viability analysis. Nevertheless, further studies of in vivo and in vitro follicular maturation are needed to strengthen this model.     

Conjugation of 1-naphthol in human gastric epithelial cells.

The biotransformation of xenobiotics is essential to the maintenance of the body's integrity. Mucosal biotransformation has been well documented in the small and large intestine of animals and humans but whether the gastric mucosa plays a role in detoxifying ingested compounds remains largely unknown. The conjugation of the model phenolic compounds, 1-naphthol, by human gastric epithelial cells was assessed in vitro. Freshly isolated and cultured epithelial cells were prepared from surgical specimens obtained from patients undergoing total gastrectomy for cancer. Cell preparations were incubated with 1- 14C-naphthol over 1 hour and the glucuronide and sulphate conjugates formed were separated by thin-layer chromatography. Conjugation of 1-naphthol was observed with both freshly isolated and cultured cells. In freshly isolated cells, the 1 hour turnover of 1 microM 1-naphthol to its glucuronide and sulphate conjugates averaged 19% and 10% respectively. At higher 1-naphthol concentrations, both types of conjugate were formed at about the same rate, up to saturation (apparent Vmax = 0.07 nmol/mg protein/minute, and apparent Km = 40 microM). In cultured cells, the 1 hour turnover of 1 microM 1-naphthol to its glucuronide and sulphate conjugates averaged 35% and 8% respectively. These results suggest that the human gastric mucosa is a detoxifying organ, and that its role with regard to chemical carcinogenesis and drug first pass metabolism deserves further assessment.     

Both GnRH agonist and continuous oral progestin treatments reduce the expression of the tyrosine kinase receptor B and mu-opioid receptor in deep infiltrating endometriosis

BACKGROUND: Deep infiltrating endometriosis (DIE) is commonly associated with severe pain. The pain can be managed successfully with GnRH agonists or continuous progestins. The precise molecular mechanism by which DIE causes pain or why hormonal treatment is effective, however, remains unclear. We recently identified three potential candidate genes that might be involved in DIE pain pathways: tyrosine kinase receptor B (TrKB), mu-opioid receptor (MOR) and serotonin transporter (5HTT). We hypothesized that if these three genes were involved in DIE-associated pain, their expression levels would probably be modulated by GnRH agonist or progestin. In this study, we compared mRNA expression levels of TrKB, MOR and 5HTT in DIE among patients pre-operatively treated with GnRH agonist, progestin or without pre-operative medical treatments. METHODS: The expression levels of TrKB, MOR and 5HTT mRNA in DIE were determined using laser capture microdissection and real-time RT-PCR techniques. RESULTS: The expression levels of TrKB in epithelial cells and MOR in stromal cells from DIE were significantly decreased in patients with pre-operative GnRH agonist or progestin. There was no significant difference in 5HTT expression levels among untreated, GnRH agonist- and progestin-treated patients. CONCLUSION: The expression levels of TrKB and MOR genes in DIE appeared to be modulated by GnRH agonist or progestin. However, the functional roles of TrKB and MOR in DIE remain to be clarified.     

Solutions entérales semi-élémentaires : pour quels patients de réanimation ?

The main features of semi-elemental enteral diets consist in their specific nitrogen fraction, made of a protein hydrolysate containing di- and tripeptides, which represent the main forms of nitrogen absorption by gastrointestinal tract. Indications focus on acute situations of malnutrition accompanied by reduced capacities of digestion and absorption. Many experimental studies support the interest of semielemental diets. However, clinical studies have been conducted mostly on small groups of patients (single centre studies in the intensive care unit) and have compared semi-elemental diets with polymeric diets, which differ most often not only by the molecular form of nitrogen supply, but also by the amino acid profile, nitrogen concentration, and other nutrients profiles (e.g. lipids, vitamins). Studies with formulas containing almost di-and tripeptides reported no metabolic benefits, because of fast kinetics regarding amino acids absorption, leading to a dramatic increase in liver oxidation, without beneficial effect on protein synthesis. This issue resulted in the development of semi-elemental enteral formula with different peptide profiles, allowing oral use (better palatability) and a drop in manufacturing costs. These formulae improve some parameters of the protein balance. However, clinical use of semi-elemental formula remains limited, in relation to the absence of documented benefits on clinical outcome including morbidity, mortality, and length of hospital stay, also because recent clinical studies are scarce. Currently accepted indications for semi-elemental diets in intensive care patients include post-operative nutritional support after digestive surgery (mainly after small bowel resection), acute pancreatitis, and adaptive phase of intestinal transplantation. Semi-elemental formula may also be used in other patients as second-line diets in case of documented intolerance to polymeric formula.