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Notes: In the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), inappropriately elevated secretion of vasopressin can result in a reduction of antidiuretic efficacy: a phenomenon known as ‘vasopressin escape’. We compared experimental SIADH with 1-deamino-8-d-arginine vasopressin (dDAVP)-excess rats, where both groups received continuous subcutaneous administration of dDAVP by osmotic minipump but the SIADH rats also received a liquid diet that induced hyponatraemia. The SIADH rats, but not the dDAVP excess rats, showed a marked attenuation of urinary concentrating ability. Vasopressin V2 receptor binding capacity and mRNA expression were similar between the two groups, but the SIADH rats showed a diminished up-regulation of aquaporin-2 (AQP-2) mRNA and protein expression. These findings indicate the presence of tonicity-response regions in the AQP-2 promoter gene, and that either hypervolemia or hypotonicity may attenuate the postreceptor signalling of vasopressin in renal collecting duct cells in SIADH rats.

Notes: Changes in leaf water relations under water stress were examined. In experiment 1, water stress was imposed by withholding irrigation to potted seedlings of deciduous oak, Quercus crispula and Q. serrata. Changes in the pressure–volume (P–V) curve in mature leaves were followed. The leaf water potential at turgor loss (Ψl,tlp) significantly decreased after 13 d of drought treatment. The bulk elastic modulus (ɛ) significantly decreased, which contributed to the maintenance of cell turgor together with the decrease in osmotic potential. In experiment 2, water stress was imposed by notching a branch of a Q. serrata tree. After the notching, the daily minimum leaf water potential (Ψl) decreased, and a significant decrease in Ψl,tlp was observed 15 d after notching. The osmotic potential at water saturation (Ψπ,sat) did not decrease significantly until 25 d after notching whereas, ɛ had already decreased significantly within 15 d after notching and increased promptly after substantial precipitation. It was confirmed that ɛ of mature leaves decreased reversibly in water stress. This response of ɛ was more rapid than that of the osmotic potential and, thus, effectively maintained cell turgor when water stress was suddenly imposed on the leaves.

Notes: Background  Anti-cancer effects of cyclooxygenase (COX)-2 inhibitors have been reported, but not fully investigated in skin and oral diseases. 5-aminolaevulinic acid (ALA)-based photodynamic therapy (PDT) for treating those patients with skin and oral lesions is a highly sophisticated procedure, but the incidence of disease recurrence after treatment is rather significant.Objective  To confirm that COX-2 could be a molecular target in adjunctive therapy to ALA-based PDT, we investigated (i) COX-2 expression in various skin and oral diseases, and (ii) the inhibitory effects on cellular growth of COX-2 selective inhibitor (nimesulide), ALA-based PDT and their combination on human oral squamous cell carcinoma (SCC) cell lines.Methods  A total of 129 biopsy samples from the skin and oral mucosal lesions were tested immunohistochemically for COX-2 expression. Then the in vitro effects of nimesulide, ALA-based PDT, and their combination were determined on two SCC cell lines, HSC-2 and HSC-4. Three different methods (MTT assay, double-staining for annexin V and propidium iodide, caspase-3/CPP32 fluorometric protease assay) were applied for evaluation of their inhibitory effects on these two cell lines.Results  Among the skin diseases, a considerable number of COX-2 high expressers were found in actinic keratosis (15 of 25, 60%), Bowen's disease (13 of 17, 76%) and extramammary Paget's disease (15 of 15, 100%). In contrast, only one of 33 (3%) basal cell carcinoma tumours was a COX-2 high expresser. Among the oral mucosal biopsies, the proportion of COX-2 high expressers increased gradually from hyperplasia (one of six, 17%) through mild dysplasia (five of eight, 63%) and moderate dysplasia (20 of 23, 87%) to severe dysplasia (two of two, 100%). Nimesulide had an inhibitory effect in vitro on HSC-2 (proven to be a COX-2 high expresser), but not on HSC-4 (a COX-2 non-expresser). While ALA-based PDT showed an inhibitory effect on both HSC-2 and HSC-4, most importantly the combination of nimesulide and ALA-based PDT demonstrated a significant synergistic effect on the cellular growth inhibition of only HSC-2, but not of HSC-4.Conclusions  Our study strongly suggests that COX-2 can be one of the molecular targets in treating various skin and oral diseases. The results from our in vitro experiments also prompt us to develop a new protocol with a combination of COX-2 selective inhibitor and ALA-based PDT for more effective treatment of those diseases.

Notes: : Proteolysis of soy protein isolates (SPI) was investigated by using pepsin with a pH of 1.5 to 4.0 at 37°C and papain at a temperature of 37°C to 80°C with pH 7.0. The glycinin fraction in native SPI was selectively hydrolyzed by pepsin in the pH 1.5 to 2.5 range. On the other hand, the p-conglycinin fraction in native SPI was selectively hydrolyzed by papain at 70°C. This selective proteolysis would be significantly correlated with the denaturation of glycinin and β-conglycinin in SPI. A protocol for preparing hydrolysates selectively enriched with glycinin or β-conglycinin was proposed.