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Objective To develop a high performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS） method for the determination of the content of 4-fluoromethamphetamine （4-FMA） in rat plasma, and to provide a methodological basis for the study of the toxicokinetics of 4-FMA in rats. Methods Rat plasma samples were added into internal standard methamphetamine （MA）. Its proteins were precipitated with methanol and then separated with Poroshell 120 EC-C18 chromatographic column. A 0.1% formic acid aqueous solution and a 0.1% formic acid acetonitrile solution were used as the mobile phase at the flow rate of 0.4 mL/min. Electrospray ionization source was used for detection in the multiple reaction monitoring （MRM） mode. Results The linear relationship was good when the mass concentration of 4-FMA in plasma samples was in the range of 5-1 000 ng/mL （r>0.999）. The limit of detection （LOD） was 3 ng/mL and the limit of quantification （LOQ） was 5 ng/mL. The accuracy was expressed as relative error （RE）, and in the range of ±5%, the intra-day precision and inter-day precision （relative standard deviation, RSD） less than 9%, and the extraction recovery rate was more than 90%. The analysis and detection of plasma samples were completed within 2.5 min. Conclusion This study developed a HPLC-MS/MS method for the determination of 4-FMA in rat plasma samples. This method is accurate, rapid, simple and sensitive and can be applied to the study of toxicokinetics of 4-FMA.

Background: Immune checkpoint inhibitors (ICIs) have significantly changed the current approach to cancer treatment. Although the use of ICIs has become the standard of care for advanced melanoma, reports of ICI use among Asian populations with melanoma are limited. Therefore, we conducted this retrospective study to assess the efficacy and safety of ICI use in Taiwanese patients.Patients: Patients with histologically confirmed melanoma treated with ICIs at Linkou Chang Gung Memorial Hospital from January 2014 to July 2019 were retrospectively reviewed. Univariant and multivariant analyses were performed to identify possible prognostic factors.Results: Among 80 patients, 45 were treatment-naïve (56.3%), and 35 received prior systemic drugs other than ICIs. Regarding treatment regimens, patients were treated with ipilimumab (n = 9), nivolumab (n = 33), pembrolizumab (n = 16), or combination drugs (n = 22). Nine patients achieved either a complete (n = 2) or partial (n = 7) response and 13 patients were stable, with a resulting response rate of 11.3% and disease control rate of 27.5%. As of the last follow-up in January 2020, patients treated with combination drugs had longer median progression-free survival (PFS) of 5.6 (95% confidence interval [CI]: 1.6–9.6) months than nivolumab (2.9 months, 95% CI: 1.9–3.9 months), pembrolizumab (3.2 months, 95% CI: 2.6–3.8 months), and ipilimumab (2.6 months, 95% CI: 2.4–2.8 months; p = 0.011). No significant differences in overall survival (OS) among the four regimens (p = 0.891) were noted. In the multivariate analysis, combination treatment, disease control, and performance ≤ 1 were independent prognostic factors for PFS. Liver metastases and no disease control were independent unfavorable prognostic factors for OS. The most common factor was skin toxicity (45%), followed by endocrine toxicity (18.8%). Patients undergoing combination treatment experienced more frequent and serious adverse events than patients undergoing monotherapy.Conclusion: ICIs demonstrated efficacy and safety in Taiwanese patients with melanoma. Combination treatment showed the greatest efficacy, but this was also accompanied by greater toxicity among the four regimens. In addition, we identified important prognostic factors, such as liver metastases, performance status, and tumor response, for both PFS and OS. These findings could provide physicians with more information to justify clinical outcomes observed in Asian patients with advanced melanoma.

Wetlands store one third of global soil organic carbon (SOC) and are strongly affected by artificial drainage. The impact of drainage-induced water-table decline on carbon cycling in different wetlands, particularly microbial transformation processes, remains unclear. To address this knowledge gap, we collected soil samples from two typical wetlands of China (a nutrient-poor bog located in Dajiuhu and a nutrient-rich fen in Hongyuan) and conducted an incubation experiment with the addition of 13C-labeled glucose to analyze the effects of short- and long-term drainage on SOC decomposition, extracellular enzyme activity, microbial carbon use efficiency (CUE), and microbial carbon accumulation efficiency (CAE). The results showed that both short- and long-term drainage significantly increased SOC decomposition rates in both wetlands (from 1.47 µg C ⋅ g-1 ⋅ h-1 in submerged soils to 2.47 µg C ⋅ g-1 ⋅ h-1 in drained soils), microbial biomass carbon derived from glucose (from 0.21 mg C ⋅ g-1 to 1.00 mg C ⋅ g-1) and CAE (from 0.29 to 0.73), but did not alter CUE (ranging from 0.34 to 0.86). Long-term drainage increased α-glucosidase activity in the Dajiuhu wetland and decreased β-glucosidase and phenol oxidase activities in the Hongyuan wetland. In conclusion' drainage enhanced the 'microbial carbon pump' and its efficiency in wetlands mainly via increasing microbial intracellular metabolism (including respiration), but also accelerated SOC decomposition. [ABSTRACT FROM AUTHOR]

Objective: Genomic biomarkers predicting immune checkpoint inhibitor (ICI) treatment outcomes for Asian metastatic melanoma have been rarely reported. This study presents data on next‐generation sequencing (NGS) and tumour microenvironment biomarkers in 33 cases. Methods: Thirty‐three patients with advanced melanoma, who underwent ICI treatment at the Chang Gung Memorial Hospital in Taiwan, were recruited. The study evaluated clinical outcomes, including response rate, disease control rate, progression‐free survival (PFS) rate and overall survival (OS) rate. Archived tissue samples from 33 cases were subjected to NGS by ACTOnco, and ACTTME was employed in 25 cases. Results: The most prevalent driver mutations were BRAF mutations (24.2%), followed by NRAS (15.2%), KIT (12.1%), KRAS (9.1%) and NF1 (9.1%) mutations. Acral/mucosal melanomas exhibited distinct mutation patterns compared to non‐acral melanomas. Tumour mutational burden estimated using ACTOnco was not associated with ICI efficacy. Notably, genetic alterations in the p53 pathway (CDKNA2 loss, MDM2 gain/amplification and TP53 mutation) accounted for 36.4% and were significantly associated with unfavourable PFS (median PFS 2.7 months vs. 3.9 months, P = 0.0394). Moreover, 26 genes were identified as differentially expressed genes that were upregulated in patients with clinical benefits compared to those without benefits. Four genes, GZMH, GZMK, AIM2 and CTLA4, were found to be associated with both PFS and OS. Conclusion: Genetic alterations in the p53 pathway may be critical in Asian patients with melanoma undergoing ICI treatment. Further investigation is required to explore this mechanism and validate these findings. [ABSTRACT FROM AUTHOR]

Background: The time schedules for response evaluation of epidermal growth factor receptor-tyrosine kinase Inhibitor (EGFR-TKI) in non-small cell lung cancer (NSCLC) patients are still ill-defined. Methods: Stage IIIB/IV patients with histologically proven NSCLC were enrolled in this study if the tumor cells bore EGFR mutations other than T790M. Eligible patients were treated with either 250 mg of gefitinib or 150 mg of erlotinib once daily. The early response rate [computed tomography (CT) scan on Day 14], definitive response rate determined on Day 56, progression-free survival (PFS), overall survival (OS), and toxicity profile were assessed prospectively. Results: Thirty-nine patients were enrolled in this study. A total of 29 patients (29/39, 74.4%) achieved partial response (PR). Twenty-one patients (21/39, 53.8%) had early radiological response on Day 14. The early radiological response rate in patients with PR was 72.4% (21/29). Only eight patients without a PR on early CT still ended with PR. Among the 29 patients with PR, the PFS (8.1 months) and OS (18.3 months) of the 21 patients with early CT response were shorter than those of the 8 patients without early CT response (11.9 and 24.0 months for PFS and OS, respectively). But the survival differences were statistically non-significant. Conclusions: A very high percentage (72.4%, 21/29) of NSCLC patients with EGFR mutations with PR demonstrates early radiological response to EGFR-TKIs, which would advocate early radiological examination for EGFR-TKI therapy in NSCLC patients.

Climate projection requires an accurate understanding for soil organic carbon (SOC) decomposition and its response to warming. An emergent view considers that environmental constraints rather than chemical structure alone control SOC turnover and its temperature sensitivity (i.e., Q10), but direct long‐term evidence is lacking. Here, using compound‐specific radiocarbon analysis of soil profiles along a 3300‐km grassland transect, we provide direct evidence for the rapid turnover of lignin‐derived phenols compared with slower‐cycling molecular components of SOC (i.e., long‐chain lipids and black carbon). Furthermore, in contrast to the slow‐cycling components whose turnover is strongly modulated by mineral association and exhibits low Q10, lignin turnover is mainly regulated by temperature and has a high Q10. Such contrasts resemble those between fast‐cycling (i.e., light) and mineral‐associated slow‐cycling fractions from globally distributed soils. Collectively, our results suggest that warming may greatly accelerate the decomposition of lignin, especially in soils with relatively weak mineral associations. [ABSTRACT FROM AUTHOR]