Melatonin mediates reactive oxygen species homeostasis via SlCV to regulate leaf senescence in tomato plants.

Melatonin (MT) functions in removing reactive oxygen species (ROS) and delaying plant senescence, thereby acting as an antioxidant; however, the molecular mechanism underlying the specific action of MT is unclear. Herein, we used the mutant plants carrying the MT decomposition gene melatonin 3-hydroxylase (M3H) in tomato to elucidate the specific mechanism of action of MT. SlM3H-OE accelerated senescence by decreasing the content of endogenous MT in plants. SlM3H is a senescence-related gene that positively regulates aging. MT inhibited the expression of the senescence-related gene SlCV to scavenge ROS, induced stable chloroplast structure, and delayed leaf senescence. Simultaneously, MT weakened the interaction between SlCV and SlPsbO/SlCAT3, reduced ROS production in photosystem II, and promoted ROS elimination. In conclusion, MT regulates ROS homeostasis and delays leaf aging in tomato plants through SlCV expression modulation.

Incidental gallbladder carcinoma diagnosed during or after laparoscopic cholecystectomy.

BACKGROUND: Gallbladder carcinoma (GC) is a highly lethal neoplasm. With the increase of cholecystectomies since the wide acceptance of laparoscopic cholecystectomy (LC), the incidental diagnosis of gallbladder carcinoma is more frequent. The aim of the present study was to report our experience with GC diagnosed during or after the performance of LC. METHODS: A total of 10,466 LCs were carried out from January 1999 to December 2007 in our hospital. Records of patients with incidental carcinoma were collected and analyzed retrospectively. RESULTS: Of all the patients, 20 (0.19%) were histopathologically diagnosed as having a GC. There were 4 men and 16 women; the median age in this group was 65.7 years (range: 37-81 years).The depth of cancer invasion was: pTis (4 cases), pT1a (2 cases), pT1b (2 cases), pT2 (6 cases), pT3 (4 cases), and pT4 (2 cases). The sensitivity and specificity of intraoperatively frozen section examination were 83.3 and 100%, respectively. Patients with in situ, pT1a and pT1b tumors underwent LC only, and there were no recurrences. The survival rate between patients with GC diagnosed during or after LC showed no difference; it was dependent on the depth of cancer invasion. CONCLUSIONS: The survival with incidental GC is related to stage, and it validates that a carefully performed LC is adequate treatment for carcinoma in situ, and stage 1a and b cancer. A frozen section examination was helpful but did not provide a definitive diagnosis. Meticulous techniques during LC, including retrieval of the gallbladder in a retrieval bag, may prevent port-site recurrence and intraperitoneal dissemination.