Phosphoinositide-specific phospholipase C (PLC) plays a pivotal role in the signal transduction of various cellular responses. However, although it is undeniably important that modulators of PLC activity be identified, no direct PLC activity modulator has been identified until now. In this study, by screening more than 10,000 different compounds in human neutrophils, we identified a compound that strongly enhances superoxide-generating activity, which is well known to be PLC-dependent. The active compound 2,4,6-trimethyl-N-(meta-3-trifluoromethylphenyl)-benzenesulfonamide (m-3M3FBS) stimulated a transient intracellular calcium concentration ([Ca 2ϩ ] i ) increase in neutrophils. Moreover, m-3M3FBS stimulated the formation of inositol phosphates in U937 cells, indicating that it stimulates PLC activity. The compound showed no cell-type specificity in terms of [Ca 2ϩ ] i increase in the various cell lines including leukocytes, fibroblasts, and neuronal cells. We also ruled out the possible involvement of heterotrimeric G proteins in m-3M3FBS-stimulated signaling by confirming the following: 1) pertussis toxin does not inhibit m-3M3FBS-induced [Ca 2ϩ ] i increase; 2) m-3M3FBS does not stimulate cyclic AMP generation; and 3) the inhibition of G q by the regulator of G proteinsignaling 2 does not affect the m-3M3FBS-induced [Ca 2ϩ ] i increase. We also observed that m-3M3FBS stimulated PLC activity in vitro. The purified isoforms of PLC that were tested (i.e., 2, 3, ␥1, ␥2, and ␦1) were activated by m-3M3FBS and showed no isoform specificity. Taken together, these results demonstrate that m-3M3FBS modulates neutrophil functions by directly activating PLC. Because m-3M3FBS is the first compound known to directly activate PLC, it should prove useful in the study of the basic molecular mechanisms of PLC activation and PLC-mediated cell signaling.
Clinicopathological features associated with young gastric cancer include upper location, linitis plastica, histopathologically diffuse type, and unresectability.
Background Several studies have shown that the neutrophil to lymphocyte ratio (NLR) in peripheral blood is a prognostic factor of various cancers. However, there is limited information on the clinical and prognostic significance of NLR in patients with metastatic advanced gastric cancer (AGC). Therefore, we examined whether the NLR can be used as a prognostic marker for predicting chemotherapeutic response and survival outcomes in metastatic AGC patients who are receiving palliative chemotherapy. Method A total of 268 patients diagnosed with metastatic AGC were enrolled. NLR was calculated from complete blood cell count taken before the first chemotherapy treatment. Patients were divided into two groups according to the median value of NLR: a high NLR group and a low NLR group. Result The median follow-up period was 340 days (range 72-1796 days) and median NLR was 3.06 (range 0.18-18.16). The high NLR group (NLR [3.0) contained 138 patients and the low NLR group (NLR B3.0) contained 130 patients. Low NLR group patients had a significantly higher chemotherapeutic disease control rate (90.0 % vs. 80.4; P = 0.028), and longer progression-free survival (PFS) and overall survival (OS) than the high NLR group patients (186 vs. 146 days; P = 0.001; 414 vs. 280 days; P \ 0.001, respectively). In multivariate analysis, NLR showed a significant association with PFS (HR 1.478; 95 % CI 1.154-1.892; P = 0.002) and OS (HR 1.569; 95 % CI 1.227-2.006; P \ 0.001). Conclusion Pretreatment NLR is a useful prognostic marker in patients with metastatic AGC who are undergoing palliative chemotherapy.
Introduction The eradication rates for Helicobacter pylori have decreased in Korea although the prevalence of this bacterium has also decreased. Antibiotic resistance is likely to be a crucial factor in H. pylori eradication success, and we therefore mapped these resistance patterns nationwide in Korea. Materials and Methods Five hundred and ninety adult subjects were prospectively enrolled from 2017 to 2018 from 15 centers across six geographic areas of Korea. A total of 580 biopsy tissues had been sampled from these patients during an upper endoscopy and were frozen at −80°C and delivered to a central laboratory. The agar dilution method was used to determine the minimum inhibitory concentration of amoxicillin, clarithromycin, metronidazole, tetracycline, ciprofloxacin, and levofloxacin for each H. pylori isolate. Results The culture success rate was 60.2% (349/580). Resistance rates against clarithromycin, metronidazole, amoxicillin, tetracycline, levofloxacin, and ciprofloxacin were 17.8%, 29.5%, 9.5%, 0%, 37.0%, and 37.0%, respectively. The geographic distribution of metronidazole and quinolone resistance was highly variable. Some subjects had multiple H. pylori strains in the antrum and body of the stomach and showed a heterogeneous resistance profile between these anatomic areas. The H. pylori multidrug resistance (MDR) rate was 25.2% (88/349) among amoxicillin, clarithromycin, metronidazole, tetracycline, and quinolone and 11.2% (39/349) among four of these major antibiotics except for quinolone. The Seoul and Chungcheong areas showed a relatively lower MDR rate. Conclusion The antibiotic resistance of H. pylori differs by drug and geographic area in Korea. Detailed nationwide antibiotic resistance mapping is needed to develop an effective H. pylori eradication strategy.
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