Atmospheric oxidation capacity and secondary pollutant formation potentials based on photochemical loss of VOCs in a megacity of the Sichuan Basin, China.

Volatile organic compounds (VOCs) are significant precursors to photochemical pollution. However, reactive VOC species are easily oxidized during transportation, resulting in a systematic underestimate of the measured concentrations. To address this, we applied an improved calculation method to correct the measured VOC concentrations into photochemical initial concentrations (PICs) in Chengdu, a megacity in the Sichuan Basin, China, which is highly vulnerable to complex pollution. In this study, 56 VOC species on the Photochemical Assessment Monitor Station (PAMS) target list were quantitatively monitored throughout all four seasons. Comparing to directly measured values, photochemically initialized total mixing ratios of VOCs increased by 18.6 % in general. The photochemical loss percentages of alkenes and aromatics were prominent in summer (68.6 %, 28.7 %) and spring (65.9 %, 24.7 %), respectively. Furthermore, we examined contributions of VOCs to atmospheric oxidation capacity (AOC) depending on PICs and found that maximum daily total AOC showed a surge in spring and summer. Besides hydroxyl radicals, daytime O3 in spring and late-afternoon nitrate radicals in summer were essential for AOC with PICs. As expected, alkenes and aromatics dominated PIC-based ozone formation potentials (OFPs). Furthermore, contribution of alkenes to secondary organic aerosol formation potentials reached 15.5 % and 7.6 % in spring and summer, respectively. Using positive matrix factorization model, we identified five VOC sources including vehicular exhaust, industrial emissions, solvent usage, biogenic sources, and liquefied petroleum gas/natural gas use. Based on PICs, biogenic sources were significantly underestimated in spring and summer. Meanwhile, m,p-xylene from solvent usage and isoprene from biogenic sources were the primary contributors to OFPs. Consequently, these results emphasize the significance of photochemically oxidized VOC concentrations, especially for reactive species in typical seasons.

Primary sources of HONO vary during the daytime: Insights based on a field campaign.

Nitrous acid (HONO) is an established precursor of hydroxyl (OH) radical and has significant impacts on the formation of PM2.5 and O3. Despite extensive research on HONO observation in recent years, knowledge regarding its sources and sinks in urban areas remains inadequate. In this study, we monitored the atmospheric concentrations of HONO and related pollutants, including gaseous nitric acid and particulate nitrate, simultaneously at a supersite in downtown Chengdu, a megacity in southwestern China during spring, when was chosen due to its tolerance for both PM2.5 and O3 pollution. Furthermore, we employed the random forest model to fill the missing data of HONO, which exhibited good predictive performance (R2 = 0.96, RMSE = 0.36 ppbv). During this campaign, the average mixing ratio of HONO was measured to be 1.0 ± 0.7 ppbv. Notably, during periods of high O3 and PM2.5 concentrations, the mixing ratio of HONO was >50 % higher compared to the clean period. We developed a comprehensive parameterization scheme for the HONO budget, and it performed well in simulating diurnal variations of HONO. Based on the HONO budget analysis, we identified different mechanisms that dominate HONO formation at different times of the day. Vehicle emissions and NO2 heterogeneous conversions were found to be the primary sources of HONO during nighttime (21.0 %, 30.2 %, respectively, from 18:00 to 7:00 the next day). In the morning (7:00-12:00), NO2 heterogeneous conversions and the reaction of NO with OH became the main sources (35.0 %, 32.2 %, respectively). However, in the afternoon (12:00-18:00), the heterogeneous photolysis of HNO3 on PM2.5 was identified as the most substantial source of HONO (contributing 52.5 %). This study highlights the significant variations in primary HONO sources throughout the day.

Levo-tetrahydropalmatine inhibits α4ß2 nicotinic receptor response to nicotine in cultured SH-EP1 cells.

Nicotine, a major component of tobacco, is highly addictive and acts on nicotinic acetylcholine receptors (nAChRs) to stimulate reward-associated circuits in the brain. It is well known that nAChRs play critical roles in mediating nicotine reward and addiction. Current FDA-approved medications for smoking cessation are the antidepressant bupropion and the nicotinic partial agonist varenicline, yet both are limited by adverse side effects and moderate efficacy. Thus, development of more efficacious medications with fewer side effects for nicotine addiction and smoking cessation is urgently needed. l-Tetrahydropalmatine (l-THP) is an active ingredient of the Chinese medicinal herb Corydalis ambigua that possesses rich neuropharmacological actions on dopamine (DA) receptors in the mesocorticolimbic dopaminergic reward pathway. L-THP has been explored as anti-addiction treatments for drug abuse including nicotine. However, the targets and mechanisms of l-THP-caused anti-nicotine effects are largely unknown. In this study we address this question by elucidating the effects of l-THP on human neuronal nAChRs using patch-clamp recordings. Human neuronal α4ß2-nAChRs were heterologously expressed in SH-EP1 human epithelial cells. Bath application of nicotine (0.1-100 µM) induced inward currents, co-application of l-THP (3 µM) inhibited nicotine-induced currents in the transfected cells. L-THP-caused inhibition was concentration-dependent (the EC50 values for inhibiting the peak and steady-state current were 18 and 2.1 µM, respectively) and non-competitive. Kinetic analysis of the whole-cell currents showed that l-THP slowed rising time and accelerated decay time constants. L-THP specifically modulated α4ß2-nAChRs, as it did not affect α7-nAChRs or α1*-nAChRs (muscle type). Interestingly, two putative α4ß2-nAChR isoforms, namely sazetidine A-activated, high-sensitive one (α42ß23-nAChR) and cytisine-activated, low-sensitive one (α43ß22-nAChR) were pharmacologically separated, and the low-sensitive one was more susceptible to l-THP inhibition than the high-sensitive one. In conclusion, we demonstrate that l-THP blocks neuronal α4ß2-nAChR function, which may underlie its inhibition on nicotine addiction.

A facile and universal method to achieve liposomal remote loading of non-ionizable drugs with outstanding safety profiles and therapeutic effect

Liposomes have made remarkable achievements as drug delivery vehicles in the clinic. Liposomal products mostly benefited from remote drug loading techniques that succeeded in amphipathic and/or ionizable drugs, but seemed impracticable for nonionizable and poorly water-soluble therapeutic agents, thereby impeding extensive promising drugs to hitchhike liposomal vehicles for disease therapy. In this study, a series of weak acid drug derivatives were designed by a simplistic one step synthesis, which could be remotely loaded into liposomes by pH gradient method. Cabazitaxel (CTX) weak acid derivatives were selected to evaluate regarding its safety profiles, pharmacodynamics, and pharmacokinetics. CTX weak acid derivative liposomes were superior to Jevtana® in terms of safety profiles, including systemic toxicity, hematological toxicity, and potential central nerve toxicity. Specifically, it was demonstrated that liposomes had capacity to weaken potential toxicity of CTX on cortex and hippocampus neurons. Significant advantages of CTX weak acid derivative-loaded liposomes were achieved in prostate cancer and metastatic cancer therapy resulting from higher safety and elevated tolerated doses.

MicroRNA­28 promotes the proliferation of non­small­cell lung cancer cells by targeting PTEN.

Non-small-cell lung cancer (NSCLC) is the fundamental form of lung cancer and the leading cause of cancer­related mortality in humans. Numerous studies have identified a role for microRNAs (miRs) in cell proliferation, invasion and metastasis in numerous types of cancer, including lung cancer. In the present study, the functional roles and molecular mechanisms of miR­28 in NSCLC tumorigenesis were investigated. Reverse transcription­quantitative PCR (RT­qPCR) was used to measure miR­28 expression levels in NSCLC tumor tissues and cell lines. A dual­luciferase assay was performed to observe the direct interaction between miR­28 and PTEN in A549 cells. Furthermore, the effect of miR­28 on the mRNA and protein expression levels of PTEN was examined by RT­qPCR and western blotting, respectively. A Cell Counting kit­8 assay was performed to identify the relationship between the miR­28/PTEN axis and tumor cell proliferation using cells infected with lentivirus (LV)­anti­miR­28 or LV­anti­miR­28 + short hairpin RNA­PTEN. miR­28 expression was upregulated in NSCLC tumor tissues and cell lines compared with the control groups. PTEN was identified as the downstream gene of miR­28 in NSCLC and was negatively regulated by miR­28. In addition, miR­28 knockdown suppressed the proliferation of A549 and H292 cells. Cells infected with LV­anti­miR­28 + short hairpin RNA­PTEN promoted tumor cell proliferation in A549 and H292 cells compared with cells infected with LV­anti­miR­28. Taken together, the present study suggested that miR­28 might serve as the promoter in the development of NSCLC by targeting PTEN. Therefore, the miR­28/PTEN axis may serve as a potential diagnostic and therapeutic target for NSCLC.

The MicroRNA hsa-let-7g Promotes Proliferation and Inhibits Apoptosis in Lung Cancer by Targeting HOXB1.

PURPOSE: The goal of this study was to explore the effects of hsa-let-7g on cell proliferation and apoptosis, and elucidate its role in lung cancer development. MATERIALS AND METHODS: The expression levels of has-let-7g and HOXB1 in tissues and cells were measured by qRT-PCR. An inhibitor of hsa-let-7g or one targeting a control messenger RNA were transfected into A549 and H1944 lung cancer cells, and the effects of hsa-let-7g dysregulation on cell viability and apoptosis were analyzed using CCK-8 and apoptosis detection assays. HOXB1 was confirmed as the target gene of hsa-let-7g, based on luciferase reporter assay results. The relationship between hsa-let-7g and HOXB1 was confirmed by co-transfection of inhibitors of hsa-let-7g and HOXB1 followed by Western blot, CCK-8, and apoptosis detection assays. RESULTS: We observed high expression of hsa-let-7g in lung cancer tissues compared to the corresponding normal tissues, and generally higher expression of hsa-let-7g in patients with advanced tumor classification. The results of CCK-8 and apoptosis detection experiments showed that the inhibition of hsa-let-7g significantly inhibited proliferation of A549 and H1944 cells, but also promoted apoptosis. HOXB1 is a specific target of hsa-let-7g, and downregulation of HOXB1 in lung cancer cells reversed the suppressive effects caused by knocking down hsa-let-7g. CONCLUSION: These data collectively suggest that the expression of hsa-let-7g inhibits lung cancer cells apoptosis and promotes proliferation by down-regulating HOXB1. The results from this study demonstrate the potential of hsa-let-7g/HOXB1 axis as a therapeutic target for the treatment of lung cancer.

Cocaine potently blocks neuronal α3ß4 nicotinic acetylcholine receptors in SH-SY5Y cells.

Cocaine is one of the most abused illicit drugs worldwide. It is well known that the dopamine (DA) transporter is its major target; but cocaine also acts on other targets including nicotinic acetylcholine receptors (nAChRs). In this study, we investigated the effects of cocaine on a special subtype of neuronal nAChR, α3ß4-nAChR expressed in native SH-SY5Y cells. α3ß4-nAChR-mediated currents were recorded using whole-cell recordings. Drugs were applied using a computer-controlled U-tube drug perfusion system. We showed that bath application of nicotine induced inward currents in a concentration-dependent manner with an EC50 value of 20 µM. Pre-treatment with cocaine concentration-dependently inhibited nicotine-induced current with an IC50 of 1.5 µM. Kinetic analysis showed that cocaine accelerated α3ß4-nAChR desensitization, which caused a reduction of the amplitude of nicotine-induced currents. Co-application of nicotine and cocaine (1.5 µM) depressed the maximum response on the nicotine concentration-response curve without changing the EC50 value, suggesting a non-competitive mechanism. The cocaine-induced inhibition of nicotine response exhibited both voltage- and use-dependence, suggesting an open-channel blocking mechanism. Furthermore, intracellular application of GDP-ßS (via recording electrode) did not affect cocaine-induced inhibition, suggesting that cocaine did not alter receptor internalization. Moreover, intracellular application of cocaine (30 µM) failed to alter the nicotine response. Finally, cocaine (1.5 µM) was unable to inhibit the nicotine-induced inward current in heterologous expressed α6/α3ß2ß3-nAChRs and α4ß2-nAChRs expressed in human SH-EP1 cells. Collectively, our results suggest that cocaine is a potent blocker for native α3ß4-nAChRs expressed in SH-SY5Y cells.

A case of atypical cholesterol side chain defect possibly caused by CYP11A1 heterozygous mutation / 中华内分泌代谢杂志

This paper reports a case of atypical cholesterol side chain enzyme deficiency caused possibly by CYP11A1p.A359V heterozygous mutation. The patient was diagnosed as congenital adrenal hyperplasia because he was born with gonadal dysplasia and there were manifestations of salt losing and pigment changing, combined with high level of plasma ACTH. Further genetic screening revealed CYP11A1p.A359V heterozygous mutations in patients with a final diagnosis of cholesterol side chain enzyme deficiency which was treated effectively to glucocorticoid.

Pharmacological and functional comparisons of α6/α3ß2ß3-nAChRs and α4ß2-nAChRs heterologously expressed in the human epithelial SH-EP1 cell line.

Neuronal nicotinic acetylcholine receptors containing α6 subunits (α6*-nAChRs) show highly restricted distribution in midbrain neurons associated with pleasure, reward, and mood control, suggesting an important impact of α6*-nAChRs in modulating mesolimbic functions. However, the function and pharmacology of α6*-nAChRs remain poorly understood because of the lack of selective agonists for α6*-nAChRs and the challenging heterologous expression of functional α6*-nAChRs in mammalian cell lines. In particular, the α6 subunit is commonly co-expressed with α4*-nAChRs in the midbrain, which masks α6*-nAChR (without α4) function and pharmacology. In this study, we systematically profiled the pharmacology and function of α6*-nAChRs and compared these properties with those of α4ß2 nAChRs expressed in the same cell line. Heterologously expressed human α6/α3 chimeric subunits (α6 N-terminal domain joined with α3 trans-membrane domains and intracellular loops) with ß2 and ß3 subunits in the human SH-EP1 cell line (α6*-nAChRs) were used. Patch-clamp whole-cell recordings were performed to measure these receptor-mediated currents. Functionally, the heterologously expressed α6*-nAChRs exhibited excellent function and showed distinct nicotine-induced current responses, such as kinetics, inward rectification and recovery from desensitization, compared with α4ß2-nAChRs. Pharmacologically, α6*-nAChR was highly sensitive to the α6 subunit-selective antagonist α-conotoxin MII but had lower sensitivity to mecamylamine and dihydro-ß-erythroidine. Nicotine and acetylcholine were found to be full agonists for α6*-nAChRs, whereas epibatidine and cytisine were determined to be partial agonists. Heterologously expressed α6*-nAChRs exhibited pharmacology and function distinct from those of α4ß2-nAChRs, suggesting that α6*-nAChRs may mediate different cholinergic signals. Our α6*-nAChR expression system can be used as an excellent cell model for future investigations of α6*-nAChR function and pharmacology.

Hippocampal synaptic and neural network deficits in young mice carrying the human APOE4 gene.

INTRODUCTION: Apolipoprotein E4 (APOE4) is a major genetic risk factor for late-onset sporadic Alzheimer disease. Emerging evidence demonstrates a hippocampus-associated learning and memory deficit in aged APOE4 human carriers and also in aged mice carrying human APOE4 gene. This suggests that either exogenous APOE4 or endogenous APOE4 alters the cognitive profile and hippocampal structure and function. However, little is known regarding how Apoe4 modulates hippocampal dendritic morphology, synaptic function, and neural network activity in young mice. AIM: In this study, we compared hippocampal dendritic and spine morphology and synaptic function of young (4 months) mice with transgenic expression of the human APOE4 and APOE3 genes. METHODS: Hippocampal dendritic and spine morphology and synaptic function were assessed by neuronal imaging and electrophysiological approaches. RESULTS: Morphology results showed that shortened dendritic length and reduced spine density occurred at hippocampal CA1 neurons in Apoe4 mice compared to Apoe3 mice. Electrophysiological results demonstrated that in the hippocampal CA3-CA1 synapses of young Apoe4 mice, basic synaptic transmission, and paired-pulse facilitation were enhanced but long-term potentiation and carbachol-induced hippocampal theta oscillations were impaired compared to young Apoe3 mice. However, both Apoe genotypes responded similarly to persistent stimulations (4, 10, and 40 Hz for 4 seconds). CONCLUSION: Our results suggest significant alterations in hippocampal dendritic structure and synaptic function in Apoe4 mice, even at an early age.

Genetic variation of long non-coding RNA TINCR contribute to the susceptibility and progression of colorectal cancer.

Colorectal cancer (CRC) accounts for the leading causes of cancer-related morbidity and mortality. However, a large part of heritable factors are warranted to be explored. Long non-coding RNAs (lncRNAs) serve critical roles in cancer development and progression. Herein, we explored effect of genetic variants of Tissue differentiation-inducing non-protein coding RNA (TINCR), a key lncRNA required for somatic tissue differentiation and tumor progression, on risk and progression of CRC. Three tagSNPs, including rs2288947, rs8105637, and rs12610531, were evaluated in in a two-stage, case-control study. Two SNPs, rs2288947 and rs8105637, were significantly associated with susceptibility of CRC in both stages. When pooled together, the allele G was significantly associated with 23% decreased risk of CRC (OR=0.77; 95% CI=0.67-0.88; P value = 1.2×10-4)for SNP rs2288947. While for SNP rs8105637, the allele A was significantly associated with 22% increased risk of CRC (OR=1.22; 95% CI=1.09-1.37; P value = 6.2×10-4). The two SNPs were also statistically associated with occurrence of lymph node metastasis of CRC. The carriers of allele G are less likely to get lymph node metastasis (OR=0.77; 95% CI=0.63-0.94; P value = 0.011) for rs2288947, and the carriers of allele A are more likely to get lymph node metastasis (OR=1.22; 95% CI=1.03-1.43; P value = 0.019) for rs8105637. These results suggest that lncRNA TINCR polymorphisms may be implicated in the development and progression of CRC.

Advances in the relationship between peritoneal microenvironment and peritoneal me-tastasis in colorectal cancer / 中国肿瘤临床

Peritoneal metastasis is very common in colorectal cancer and often indicates bad prognosis. The peritoneum, which con-tains an abundant supply of blood and specific types of resident and migrating cells, lines the surface of the abdominal wall and covers the abdominal organs. The combination of cells, extracellular matrix, and local unique physicochemical composition of the abdominal cavity provide a complex and relatively stable peritoneal microenvironment. The cells in this environment can be induced by cancer cells to be involved in tumor growth, invasion, and peritoneal metastasis. This review summarizes the major cellular components in-volved in the peritoneal microenvironment.

Advances in the relationship between peritoneal microenvironment and peritoneal me-tastasis in colorectal cancer / 中国肿瘤临床

Peritoneal metastasis is very common in colorectal cancer and often indicates bad prognosis. The peritoneum, which con-tains an abundant supply of blood and specific types of resident and migrating cells, lines the surface of the abdominal wall and covers the abdominal organs. The combination of cells, extracellular matrix, and local unique physicochemical composition of the abdominal cavity provide a complex and relatively stable peritoneal microenvironment. The cells in this environment can be induced by cancer cells to be involved in tumor growth, invasion, and peritoneal metastasis. This review summarizes the major cellular components in-volved in the peritoneal microenvironment.

LncRNA GAS5 contributes to lymphatic metastasis in colorectal cancer.

Colorectal cancer (CRC) ranks the third most common type of cancer worldwide. However, the detailed molecular mechanisms underlying these processes are poorly understood. Recent studies have shown that lncRNAs play important roles in carcinogenesis and progression of CRC. The lncRNA growth arrest special 5 (GAS5), was previously identified to be down-regulated and functions as a tumor suppressor gene in many kinds of cancers. In current two-stage, case-control study, we systematically evaluated the potential role of lncRNA GAS5 and its genetic variation rs145204276 in the development and metastasis process of CRC in a Chinese population. We found the allele del of rs145204276 was significantly associated with 21% decreased risk of CRC (OR=0.79; 95% CI=0.70-0.89; P value = 5.21×10-5). Compared with the genotype ins/ins, both the genotype ins/del (OR=0.78; 95% CI=0.68-0.91) and del/del (OR=0.64; 95% CI=0.49-0.84) showed decreased susceptibility. For both in colon and rectum cancers, the associations kept statistically significant (OR=O.78 and 0.80, while P value = 4.56×10-4, and 3.80×10-3, respectively). The results also showed that the carriers of allele del are less likely to get lymph node metastasis (OR=0.80; 95% CI=0.68-0.95; P value = 0.010). Taken together, our findings provided strong evidence for the hypothesis that GAS5 rs145204276 were significantly associated with the susceptibility and progression of CRC.

MicroRNA-103 promotes tumor growth and metastasis in colorectal cancer by directly targeting LATS2.

Colorectal cancer (CRC) has become the third most common cancer worldwide and leads to a high mortality rate. Although colorectal cancer has been studied widely, the underlying molecular mechanism remains unclear. Increasing evidence shows that the abnormal expression of microRNAs (miRNAs) is involved in tumorigenesis. Previous studies have reported that miRNA-103 (miR-103) is dysregulated in CRC; however, the expression, function and mechanism of miR-103 in CRC are not well known. The present study showed that miR-103 was overexpressed in the primary tumor tissues of patients with CRC and was significantly associated with a more aggressive phenotype of CRC in patients. Survival rate analysis demonstrated that CRC patients with high miR-103 expression had a poorer overall survival compared with CRC patients with low miR-103 expression. In CRC cell lines, miR-103 inhibition significantly decreased the proliferation, invasion and migration of the cells in vitro. Furthermore, miR-103 repressed large tumor suppressor kinase 2 (LATS2) expression by directly binding to the LATS2-3'-untranslated region, and an inverse correlation was identified between the expression of miR-103 and LATS2 messenger RNA in primary CRC tissues. In addition, the restoration of LATS2 led to suppressed proliferation, invasion and migration of CRC cells. In vivo, miR-103 promotes tumor growth in nude mice. In summary, miR-103 performs a critical role in the promotion of the invasive and metastatic capacities of CRC, possibly by directly targeting LATS2. This miRNA may be involved in the development and progression of CRC.

Preparation and characterization of ceria-zirconia composite for enrichment and identification of phosphopeptides.

Ceria-zirconia composites at different molar ratios were synthesized. Several methods were used to characterize these composites, including X-ray photoelectron spectroscopy, surface area and surface acid-base property detection. A one-step method for isolation and identification of phosphopeptides from peptide mixture was created using these ceria-zirconia composites. Using tryptic digest of standard phosphorylated protein, we have shown that these enrichment and dephosphorylation activities are effective. The adsorption capacity and catalytic property of ceria-zirconia composites at different molar ratios and calcinated temperatures were studied. In combination with MALDI-TOF-based peptide mass finger printing technique, we have established a method to utilize the enrichment/dephosphorylation dual properties of these ceria-zirconia composites for the analysis of phosphoprotein in nonfat milk successfully.

The use of liquid phase deposition prepared phosphonate grafted silica nanoparticle-deposited capillaries in the enrichment of phosphopeptides.

In our current work, we describe how open tubular-immobilized metal-ion affinity chromatography (OT-IMAC) capillary columns connected to a solid phase microextraction (in-tube SPME) device can be used for the enrichment of phosphopeptides. A phosphonate modified silica nanoparticle (NP)-deposited capillary was prepared by liquid phase deposition (LPD), and used for the immobilization of Fe(3+), Zr(4+) or Ti(4+). The enrichment capacities of three different OT-IMAC capillary columns were compared by using tryptically digested alpha-casein as sample. The improved extraction efficiency in our technique was demonstrated by comparing to a directly modified capillary, and a comparison of phosphopeptide extraction from simple and complex samples was tested for both modes. Our results show that the NP-IMAC-Zr(4+) capillary column can be used to selectively isolate phosphopeptides from real samples, and can enrich for beta-casein phosphopeptides from concentrations as low as 1.7x10(-9) M.

Rapid determination of Delta9-Tetrahydrocannabinol in saliva by polymer monolith microextraction combined with gas chromatography-mass spectrometry.

A method was developed for the determination of Delta(9)-Tetrahydrocannabinol (THC) in saliva by polymer monolith microextraction (PMME) combined with gas chromatography-mass spectrometry. The poly(methacrylic acid-co-ethylene glycol dimethacrylate) (p(MAA-co-EGDMA)) monolithic capillary column was selected as the extraction medium of PMME, which showed high extraction capacity towards THC in saliva. To reach optimum PMME extraction performance, several PMME parameters were investigated, including matrix pH, flow rate for extraction, sampling volume and elution solvent. Under the optimal conditions, good extraction efficiency was obtained with no matrix interference in the process of extraction and the subsequent GC-MS analysis. In the selected-ion monitoring (SIM) mode, the limit of detection (LOD) for THC was 0.68 ng/mL. The linearity range of the method was 3-300 ng/mL. Excellent reproducibility of the method was exhibited by intra- and inter-day precisions, yielding the relative standard deviations (R.S.D.s) less than 12%; recoveries higher than 89%. The proposed method was proved to be rapid, sensitive, and competently applied to the determination of THC in saliva samples.