[Efficacy comparison between laparoscopy and open surgery in the treatment of gastric gastrointestinal stromal tumors larger than 2 cm using multicenter propensity score matching method]

Objective: To compare the efficacy between laparoscopy and open surgery for gastric gastrointestinal stromal tumor (GIST) larger than 2 cm. Methods: A multicenter retrospective cohort study was performed. Inclusion criteria: long diameter of primary gastric GIST > 2 cm; undergoing laparoscopy or open surgery; diagnosis confirmed by postoperative pathology without distant metastasis; without preoperative targeted therapy. Clinicopathological data of 857 gastric GIST patients, including 320 in PLA General Hospital, 284 in Shanghai Renji Hospital, 175 in Wuhan Union Hospital and 78 in Tianjin Cancer Hospital, from January 2010 to May 2017 were retrospectively collected. There were 418 males and 439 females, mainly aged between 50 and 70 years old. Among 857 patients, 413 were in the laparoscopy group and 444 in the open group. The nearest neighbor matching of propensity score matching method was conducted with 1:1 matching based on tumor location and size between laparoscopy and open group to obtain samples of covariate equilibrium, and the caliper value was 0.04. The t test, χ(2) test and Wilcoxon rank test were used to compare short-term efficacy, and the Kaplan-Meier curve and log rank test were applied to compare long-term outcomes between the two groups. Results: After propensity score matching, laparoscopy group and open group both enrolled 293 cases. The baseline data, including age, gender, tumor location, tumor long diameter, NIH classification, etc. were not significantly different between the two groups (all P>0.05). Compared with the open group, the laparoscopy group had less intraoperative blood loss [<100 ml: 2.9% (155/293) vs. 36.2% (106/293), Z=-12.857, P<0.001], shorter time to postoperative feeding [(4.0±0.2) days vs. (5.3±0.9) days, t=1.505, P=0.003] and to the removal of drainage tube [(4.8±1.0) days vs. (6.5±1.0) days, t=1.847, P=0.008], and shorter postoperative hospital stay [(8.6±0.3) days vs. (10.5±0.3) days, t=4.235, P<0.001]. Subgroups analysis according to anatomical location: (1) Gastric cardia and pylorus: there were no statistically significant differences in perioperative parameters between the two groups (all P>0.05). (2) Stomach base: feeding time after surgery [(4.0±0.2) days vs. (4.5±0.2) days, t=0.512, P=0.038], drainage tube removal time [(5.1±0.4) days vs. (6.4±0.6) days, t=0.517, P=0.044], postoperative hospital stay [(8.0±0.5) days vs. (11.1±0.9) days, t=0.500, P=0.002] were all significantly shorter in the laparoscopy group as compared to the open group, while the differences in other perioperative parameters were not statistically significant (all P>0.05). (3) Lesser curvature of the stomach: the laparoscopy group had less intraoperative blood loss [<100 ml ratio: 58.1% (43/74) vs. 33.7% (25/74), Z=7.632, P=0.034], shorter gastric tube removal time [(2.7±0.2) days vs. (3.2±0.3) days, t=0.503, P=0.007], earlier postoperative passage of gas [(2.8±0.1) days vs. (3.4±0.2) days, t=0.532, P=0.030], earlier postoperative feeding [(3.6±0.2) days vs. (4.3±0.2) days, t=0.508, P=0.020], shorter drainage tube removal time [(4.2±0.4) days vs. (5.7±0.5) days, t=0.508, P=0.020] and postoperative hospital stay [(8.3±0.6) days vs. (10.7±0.3) days, t=0.502, P=0.006] as compared to the open group. (4) Great curvature of the stomach: the laparoscopy group presented less intraoperative blood loss [<100 ml ratio: 52.7% (39/74) vs. 36.5% (27/74), Z=7.681, P=0.032], earlier gastric tube removal [(2.6±0.2) days vs. (3.6±0.2) days, t=0.501, P=0.001], earlier postoperative passage of gas [(2.7±0.2) days vs. (3.4±0.2) days, t=0.501, P=0.016], earlier postoperative feeding [(3.6±0.2) days vs. (4.7±0.2) days, t=0.500, P=0.001], shorter drainage tube removal time [(4.0±0.5) days to (5.9±0.4) days, t=0.508, P=0.002] and postoperative hospital stay [(7.5±0.3) days to (9.5±0.1) days, t=0.500, P=0.001] than the open group. Subgroup analysis according to tumor size: (1) Tumor long diameter 2.0-5.0 cm: the laparoscopy group had earlier passage of gas [(2.9±0.1) days vs. (3.5±0.1) days, t=0.500, P=0.001], earlier postoperative feeding [(4.5±0.1) days vs. (5.0±0.2) days, t=0.501, P=0.013], shorter drainage tube removal time [(4.8±0.3) days vs. (6.0±0.3) days, t=0.511, P=0.008] and postoperative hospital stay [(8.1±0.4) days to (10.1±0.3) days, t=0.513, P=0.001] than the open group. (2) Tumor long diameter 5.1-10.0 cm: in the laparoscopic group, postoperative feeding time [(4.0±0.2) days vs. (4.7±0.2) days, t=0.506, P=0.015], drainage tube removal time [(4.6±0.4) days vs. (6.4±0.5)) days, t=0.501, P=0.004], postoperative hospital stay [(8.2±0.3) days vs. (10.9±0.6) days, t=0.500, P=0.001] were all shorter than those in the open group. No intraoperative and postoperative complications were observed in each group. The 5-year recurrence-free survival rates of the laparoscopy group and the open group were 95.4% and 91.6%, respectively (P=0.734), and the 5-year overall survival rates were 93.8% and 90.8% (P=0.691), respectively, and the differences were not statistically significant. Conclusions: In experienced medical centers, laparoscopic surgery for gastric GIST larger than 2 cm is safe and feasible, and can achieve comparable efficacy with open surgery. For gastric GISTs which do not locate in the greater curvature and the anterior wall of the stomach, and whose long diameter is ≤5 cm, laparoscopic surgery does not increase the risk of recurrence and metastasis, and can accelerate postoperative recovery.

Development of EST-SSR and TRAP markers from transcriptome sequencing data of the mango

Mango is one of the most commercially important fruit crops in tropical and subtropical regions. To increase the efficiency of breeding strategies, two EST-derived marker systems were developed in the present study using information from the mango fruit transcriptome. Using simple sequence repeats, 218 of 230 primer pairs showed stable amplification for 7 mango genotypes with amplicons ranging from 84 to 160 bp; 93 of the primer pairs yielded polymorphic products. The proportion of polymorphic bands ranged from 16.67 to 100%, with a mean of 55.64%. In contrast, 86 primer pairs exhibited good amplification with clear bands for target region amplification polymorphism analysis, and a total of 66 primer combinations were polymorphic. These two novel sets of EST-derived markers will be of use in future studies of genetic diversity, genetic map construction, and marker-assisted selection in mango.

A novel alpha subunit in rat brain GABAA receptors

Two cDNAs (alpha 1 and alpha 4) from rat brain cDNA libraries encode isoforms of the alpha subunit of the GABA/benzodiazepine receptor, which differ at 30% of their amino acid residues. Northern blot analysis and in situ hybridization histochemistry show that alpha 1 and alpha 4 mRNAs have distinct sizes and distinct regional and cellular distributions in rat brain: both mRNAs are found in the cortex and hippocampus; however, only the alpha 1 mRNA is detected in the cerebellum. We injected RNA transcribed from alpha 1 and alpha 4 cDNAs into Xenopus oocytes, together with an RNA for a rat beta subunit. We obtained GABA-dependent inward currents that were reversibly blocked by picrotoxin. Picrotoxin alone, applied to oocytes producing the alpha and beta polypeptides, elicited an outward current. We suggest that these polypeptides together produce GABA-gated ion channels that can also open spontaneously.