Qualitative and Quantitative Analysis of Five Indoles or Indazole Amide Synthetic Cannabinoids in Suspected E-Cigarette Oil by GC-MS.

OBJECTIVES: To establish the GC-MS qualitative and quantitative analysis methods for the synthetic cannabinoids, its main matrix and additives in suspicious electronic cigarette (e-cigarette) oil samples. METHODS: The e-cigarette oil samples were analyzed by GC-MS after diluted with methanol. Synthetic cannabinoids, its main matrix and additives in e-cigarette oil samples were qualitatively analyzed by the characteristic fragment ions and retention time. The synthetic cannabinoids were quantitatively analyzed by using the selective ion monitoring mode. RESULTS: The linear range of each compound in GC-MS quantitative method was 0.025-1 mg/mL, the matrix recovery rate was 94%-103%, the intra-day precision relative standard deviations (RSD) was less than 2.5%, and inter-day precision RSD was less than 4.0%. Five indoles or indazole amide synthetic cannabinoids were detected in 25 e-cigarette samples. The main matrixes of e-cigarette samples were propylene glycol and glycerol. Additives such as N,2,3-trimethyl-2-isopropyl butanamide (WS-23), glycerol triacetate and nicotine were detected in some samples. The content range of synthetic cannabinoids in 25 e-cigarette samples was 0.05%-2.74%. CONCLUSIONS: The GC-MS method for synthesizing cannabinoid, matrix and additive in e-cigarette oil samples has good selectivity, high resolution, low detection limit, and can be used for simultaneous qualitative and quantitative analysis of multiple components; The explored fragment ion fragmentation mechanism of the electron bombardment ion source of indole or indoxamide compounds helps to identify such substances or other compounds with similar structures in cases.

Study on the metabolic process of synthetic cannabinoids 4F-MDMB-BINACA and 4F-MDMB-BICA in human liver microsome and zebrafish model via UHPLC-QE Orbitrap MS.

In order to address the increasing abuse of synthetic cannabinoids, on July 1, 2021, China listed the whole category of synthetic cannabinoids in the Supplementary Catalog for the Control of Non-medicinal Narcotic Drugs and Psychotropic Substances. Because synthetic cannabinoids metabolize rapidly, techniques are urgently needed to identify the phase I metabolites of new synthetic cannabinoids, as well as the symbol metabolites, which can be used for detection in real cases. In this study, we used pooled human liver microsome (pHLM) and zebrafish combined with ultra-high-performance liquid chromatography (UHPLC) Q Exactive Orbitrap MS to identify the phase I metabolites of two new synthetic cannabinoids 4F-MDMB-BICA and 4F-MDMB-BINACA in vitro and in vivo, respectively. We studied the toxicokinetics of 4F-MDMB-BICA and 4F-MDMB-BINACA by sampling from a pHLM incubation system at different time points to study the change in metabolites over time. We detected a total of 14 metabolites of 4F-MDMB-BINACA and 16 metabolites of 4F-MDMB-BICA in this study. Metabolites of 4F-MDMB-BICA were detected in vitro for the first time. One metabolite of 4F-MDMB-BINACA, M05, was discovered for the first time. Based on the toxicokinetics results, we recommend three metabolites (M03, M11, M12) of 4F-MDMB-BINACA and three metabolites (M10, M12, M14) of 4F-MDMB-BICA as their symbol metabolites. The results showed that these two structurally similar synthetic cannabinoids 4F-MDMB-BINACA and 4F-MDMB-BICA had similar metabolic processes, as well as similar structures of their main symbol metabolites.

Risk Factors for and Clinical Outcomes of Polymicrobial Acinetobacter baumannii Bloodstream Infections.

Background: Although the clinical features of Acinetobacter baumannii bloodstream infection are well described, the specific clinical characteristics of polymicrobial Acinetobacter baumannii bloodstream infection have been rarely reported. The objective of this study was to examine the risk factors for and clinical outcomes of polymicrobial Acinetobacter baumannii bloodstream infection. Methods: A retrospective observational study was performed from January 2013 to December 2018 in a tertiary hospital. All patients with Acinetobacter baumannii bloodstream infection were enrolled, and the data were collected from the electronic medical records. Results: A total of 594 patients were included, 21% (126/594) of whom had polymicrobial infection. The most common copathogen was Klebsiella pneumoniae (20.81%), followed by Pseudomonas aeruginosa (16.78%) and Enterococcus faecium (12.08%). Compared with monomicrobial Acinetobacter baumannii bloodstream infection, polymicrobial Acinetobacter baumannii bloodstream infection mostly originated from the skin and soft tissue (28.6% vs. 10.5%, p < 0.001). Multivariate analysis revealed that burn injury was independently associated with polymicrobial Acinetobacter baumannii bloodstream infection (adjusted odds ratio, 3.569; 95% confidence interval, 1.954-6.516). Patients with polymicrobial Acinetobacter baumannii bloodstream infection were more likely to have a longer hospital length of stay [40 (21, 68) vs. 27 (16, 45), p < 0.001] and more hospitalization days after bloodstream infection than those with monomicrobial Acinetobacter baumannii bloodstream infection [22 (8, 50) vs. 13 (4, 28), p < 0.001]. However, no significant difference in mortality was observed between the two groups. Conclusions: Approximately one-fifth of Acinetobacter baumannii bloodstream infections were polymicrobial in this cohort. The main sources were skin and soft tissue infections, and burn injury was the only independent risk factor. Although mortality did not differ between the groups, considering the limitations of the study, further studies are required to assess the impact of polymicrobial (vs. monomicrobial) Acinetobacter baumannii bloodstream infection on outcomes.

Expression of CDK13 Was Associated with Prognosis and Expression of HIF-1α and beclin1 in Breast Cancer Patients.

OBJECTIVE: To investigate role and clinical significance of CDK13 in breast cancer patients. METHODS: A total of 189 cases of breast cancer were enrolled during March 2013 to March 2015. Immunohistochemistry (IHC) was used for measurement of CDK13, HIF-1α and beclin1. Clinical characteristics of age, BMI, TNM stage, pathological types, and tumor diameter, were recorded. Patients' 5-year overall survival and recurrence were followed up. All patients were followed up for 5 years or to the last follow-up. RESULTS: The expression levels of CDK13 and HIF-1αin breast cancer tissues were up-regulated and beclin1 was down-regulated than in the paracancerous non-tumor tissues. CDK13 was positively correlated with HIF-1α and negatively correlated with beclin1 in breast cancer tissues. The patients with higher expression of CDK13 showed significantly higher rates of TNM III-IV, higher rates of lymph node metastasis, distant metastasis and larger tumor size. The mortality and recurrence rates were higher in high expression CDK13 patients than in low CDK13 expression patients, however with no significant difference. K-M curve showed patients with higher CDK13 showed lower 5-year overall survival and lower disease-free survival time, however with no significant difference. CONCLUSION: CDK13 was overexpressed in breast cancer tissues, and patients with higher CDK13 had poorer clinical outcomes. Further studies are still needed to reveal the clinical significance of CDK13 in breast cancer.

Clinical Characteristics, Risk Factors, and Outcomes of Patients with Polymicrobial Klebsiella pneumoniae Bloodstream Infections.

BACKGROUND: Polymicrobial Klebsiella pneumoniae bloodstream infection (KP-BSI) has been reported to account for more than 10% of all KP-BSI, but few studies have characterized polymicrobial KP-BSI. Our study investigated the clinical characteristics, risk factors, and outcomes of polymicrobial KP-BSI by comparing with monomicrobial KP-BSI. METHODS: We conducted a single-center retrospective cohort study of patients with KP-BSI from 1 January 2013 to 31 December 2018 and collected the clinical data by reviewing electronic medical records. RESULTS: Of the 818 patients with KP-BSI recruited, 13.9% (114/818) were polymicrobial KP-BSI. The severity of illness in polymicrobial and monomicrobial KP-BSI was similar, while the rate of resistance to carbapenems was obviously higher in polymicrobial KP-BSI (78.1% vs. 65.6%, p = 0.009). On multivariate analysis, hospitalization in burn ward (odds ratio (OR) 6.13, 95% confidence interval (CI) 2.00-18.76, p = 0.001) and intensive care unit (OR 2.39, 95% CI 1.05-5.43, p = 0.038) was independently associated with polymicrobial KP-BSI. Gram-negative bacteria accounted for the highest proportion (68.9%) among copathogens of polymicrobial KP-BSI, whereas gram-positive bacteria (22.9%) and Candida (8.2%) ranked the second and the third, respectively, with Acinetobacter baumannii being the most common (23.0%). Patients with polymicrobial KP-BSI had longer hospital days after BSI onset and total hospital days than patients with monomicrobial KP-BSI (median (interquartile range (IQR)), 19 (5, 39) vs. 12 (6, 25), 37 (21, 67) vs. 29 (16, 53), respectively, p < 0.05). The mortality did not differ between polymicrobial KP-BSI and monomicrobial KP-BSI (all p > 0.05). CONCLUSIONS: It was observed that polymicrobial KP-BSI accounted for a significant proportion among all KP-BSI in the current study. Hospitalization in burn ward and intensive care unit was an independent risk factor for the development of polymicrobial KP-BSI. The patients with polymicrobial KP-BSI had a higher rate of carbapenem-resistant K. pneumoniae and might have poor outcomes compared to monomicrobial KP-BSI.

The identification and analytical characterization of 2,2'-difluorofentanyl.

New psychoactive substances (NPS) have expanded their distribution and become widely available in the global market in recent years. The illicit use of fentanyl and its analogs has become an important worldwide concern linked to their high potency and risk of fatal overdose. This study describes the analytical characterization of a new fentanyl derivative N-(1-(2-fluorophenethyl)-4-piperidinyl)-N-(2-fluorophenyl)propionamide (2,2'-difluorofentanyl). Identification was based on ultra-high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UHPLC-QTOF-MS), gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. To our knowledge, this study is the first to report on analytical data for this compound. The most abundant fragment ion in the electrospray ionization (ESI) mass spectrum under collision-induced dissociation (CID) mode was formed by the cleavage between the piperidine ring and the N-phenyl-amide moiety of the protonated molecule. Two diagnostic ions in the electron ionization (EI) mass spectrum were formed by the loss of a tropylium ion (M-91), and by the degradation of the piperidine ring and dissociate of the COC2 H5 moiety altogether, respectively.

Identification and analytical characterization of six synthetic cannabinoids NNL-3, 5F-NPB-22-7N, 5F-AKB-48-7N, 5F-EDMB-PINACA, EMB-FUBINACA, and EG-018.

Clinical and forensic toxicology laboratories are continuously confronted by analytical challenges when dealing with the new psychoactive substances phenomenon. The number of synthetic cannabinoids, the chemical diversity, and the speed of emergence make this group of compounds particularly challenging in terms of detection, monitoring, and responding. Three indazole 7N positional isomer synthetic cannabinoids, two ethyl 2-amino-3-methylbutanoate-type synthetic cannabinoids, and one 9H-carbazole substituted synthetic cannabinoid were identified in seized materials. These six synthetic cannabinoid derivatives included: 1H-benzo[d] [1,2,3]triazol-1-yl 1-(5-fluoropentyl)-1H-pyrrolo[2,3-b]pyridine-3-carboxylate (NNL-3, 1), quinolin-8-yl 1-(5-fluoropentyl)-1H-pyrrolo[2,3-b]pyridine-3-carboxylate (5F-NPB-22-7N, 2), N-((1 s,3 s)-adamantan-1-yl)-1-(5-fluoropentyl)-1H-pyrrolo[2,3-b]pyridine-3-carboxamide (5F-AKB-48-7N, 3), ethyl 2-(1-(5-fluoropentyl)-1H-indazole-3-carboxamido)-3,3-dimethylbutanoate (5F-EDMB-PINACA, 4), ethyl 2-(1-(4-fluorobenzyl)-1H-indazole-3-carboxamido)-3-methylbutanoate (EMB-FUBINACA, 5), and naphthalen-1-yl(9-pentyl-9H-carbazol-3-yl)methanone (EG-018, 6). The identification was based on ultra-high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UHPLC-QTOF-MS), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance spectroscopy (NMR). The analytical characterization of these six synthetic cannabinoids was described, so as to assist forensic laboratories in identifying these compounds or other substances with similar structure in their case work. To our knowledge, no analytical data about the compounds 1-5 have appeared until now, making this the first report on these compounds. The GC-MS data of 6 has been reported, but this study added the LC-MS, NMR, and Fourier transform infrared (FTIR), data to render the analytical data collection process more complete. Copyright © 2017 John Wiley & Sons, Ltd.

Identification of five substituted phenethylamine derivatives 5-MAPDB, 5-AEDB, MDMA methylene homolog, 6-Br-MDMA, and 5-APB-NBOMe.

This paper reports analytical properties of five substituted phenethylamine derivatives seized from a clandestine laboratory. These five derivatives include 5-(2-methylaminopropyl)-2,3-dihydrobenzofuran (5-MAPDB, 1), 5-(2-aminoethyl)-2,3-dihydrobenzofuran (5-AEDB, 2), N,2-dimethyl-3-(3,4-methylenedioxyphenyl)propan-1-amine (MDMA methylene homolog, 3), 6-bromo-3,4-methylenedioxymethamphetamine (6-Br-MDMA, 4), and 1-(benzofuran-5-yl)-N-(2-methoxybenzyl)propan-2-amine (5-APB-NBOMe, 5). These compounds were identified by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance spectroscopy (NMR). No analytical properties about compounds 1-4 have appeared until now, making this the first report on these compounds. Copyright © 2016 John Wiley & Sons, Ltd.

Identification of three cannabimimetic indazole and pyrazole derivatives, APINACA 2H-indazole analogue, AMPPPCA, and 5F-AMPPPCA.

This paper reports analytical properties of three cannabimimetic indazole and pyrazole derivatives seized from a clandestine laboratory. These three new synthetic cannabinoids include N-(1-adamantyl)-2-pentyl-2H-indazole-3-carboxamide (APINACA 2H-indazole analogue, 1), N-(1-adamantyl)-4-methyl-1-pentyl-5-phenyl-1H-pyrazole-3-carboxamide (AMPPPCA, 2), and N-(1-adamantyl)-1-(5-fluoropentyl)-4-methyl-5-phenyl-1H-pyrazole-3-carboxamide (5F-AMPPPCA, 3). These compounds were identified by liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QTOF-MS), gas chromatography-time-of-flight-mass spectrometry (GC-TOF-MS), and nuclear magnetic resonance (NMR) spectroscopy. No analytical properties and pharmacological activities about compounds 1-3 have appeared until now, making this the first report on these compounds. Copyright © 2016 John Wiley & Sons, Ltd.

Identification of five pyrrolidinyl substituted cathinones and the collision-induced dissociation of electrospray-generated pyrrolidinyl substituted cathinones.

This article reports on the analytical properties of five pyrrolidinyl substituted cathinones: α-pyrrolidinononaphenone (α-PNP, 1), 4-chloro-α-pyrrolidinopropiophenone (4-Cl-α-PPP, 2), 4-chloro-α-pyrrolidinovalerophenone (4-Cl-α-PVP, 3), 5-dihydrobenzofuranpyrovalerone (5-DBFPV, 4), and 2-(pyrrolidin-1-yl)-1-(5,6,7,8-tetrahydronaphthalen-2-yl)hexan-1-one (ß-THNPH, 5). These identifications were based on liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QTOF-MS), gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR). To our knowledge, no analytical data about α-PNP, 4-Cl-α-PPP, 4-Cl-α-PVP, and ß-THNPH have appeared until now, making this the first report on these compounds. Moreover, in order to study the collision-induced dissociation (CID) characteristic fragmentation routes of pyrrolidinyl substituted cathinones, a total number of 13 pyrrolidinyl substituted cathinones were selected and discussed. The major fragmentation pathways under CID mode are produced, leading to the formation of characteristic ions. Product ions of [M-C4 H9 N]+ and Cn H2n N+ indicate the presence of pyrrolidinyl substitution. Characteristic fragments are also produced via the cleavages of the CH-N(CH2 )4 bond and the CO-CHN bond. Copyright © 2016 John Wiley & Sons, Ltd.

Identification and analytical characterization of four synthetic cathinone derivatives iso-4-BMC, ß-TH-naphyrone, mexedrone, and 4-MDMC.

New psychoactive substances (NPS) have gained much popularity on the global market over the last number of years. The synthetic cathinone family is one of the most prominent groups and this paper reports on the analytical properties of four synthetic cathinone derivatives: (1) 1-(4-bromophenyl)-1-(methylamino)propan-2-one (iso-4-BMC or iso-brephedrone), (2) 2-(pyrrolidin-1-yl)-1-(5,6,7,8-tetrahydronaphthalen-2-yl)pentan-1-one (ß-TH-naphyrone), (3) 3-methoxy-2-(methylamino)-1-(4-methylphenyl)propan-1-one (mexedrone), and (4) 2-(dimethylamino)-1-(4-methylphenyl)propan-1-one (4-MDMC). These identifications were based on liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QTOF-MS), gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectroscopy. To our knowledge, no chemical or pharmacological data about compounds 1-3 have appeared until now, making this the first report on these compounds. The Raman and GC-MS data of 4 have been reported, but this study added the LC-MS and NMR data for additional characterization. Copyright © 2016 John Wiley & Sons, Ltd.

Identification and analytical characterization of nine synthetic cathinone derivatives N-ethylhexedrone, 4-Cl-pentedrone, 4-Cl-α-EAPP, propylone, N-ethylnorpentylone, 6-MeO-bk-MDMA, α-PiHP, 4-Cl-α-PHP, and 4-F-α-PHP.

Clinical and forensic toxicology laboratories are continuously confronted by analytical challenges when dealing with the new psychoactive substances (NPS) phenomenon. In this study, the analytical characterization of nine synthetic cathinones is described: 2-(ethylamino)-1-phenylhexan-1-one (N-ethylhexedrone 1), 1-(4-chlorophenyl)-2-(methylamino)pentan-1-one (4-Cl-pentedrone 2), 1-(4-chlorophenyl)-2-(ethylamino)pentan-1-one (4-Cl-α-EAPP 3), 1-(3,4-methylenedioxyphenyl)-2-propylaminopropan-1-one (propylone 4), 1-(3,4-methylenedioxyphenyl)-2-ethylaminopentan-1-one (N-ethylnorpentylone 5), 1-(6-methoxy-3,4-methylenedioxyphenyl)-2-methylaminopropan-1-one (6-MeO-bk-MDMA 6), 4-methyl-1-phenyl-2-(pyrrolidin-1-yl)pentan-1-one (α-PiHP 7), 1-(4-chlorophenyl)-2-(pyrrolidin-1-yl)hexan-1-one (4-Cl-α-PHP 8), and 1-(4-fluorophenyl)-2-(pyrrolidin-1-yl)hexan-1-one (4-F-α-PHP 9). The identification was based on ultra-high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UHPLC-QTOF-MS), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) spectroscopy. The mass-spectral fragmentations of these compounds following collision-induced dissociation (CID) and electron ionization (EI) were studied to assist forensic laboratories in identifying these compounds or other substances with similar structure in their case work. To our knowledge, no analytical data about the compounds 1-4, 7, and 8 have appeared until now, making this the first report on these compounds. The GC-MS data of 5, 6 and 9 has been reported, but this study added the LC-MS, Fourier Transform Infrared (FTIR) and NMR data for additional characterization. Copyright © 2016 John Wiley & Sons, Ltd.

Identification and analytical characterization of four synthetic cannabinoids ADB-BICA, NNL-1, NNL-2, and PPA(N)-2201.

Since the first appearance as psychotropic drugs in illegal markets in 2008, the spread of synthetic cannabinoids is becoming a serious problem in many countries. This paper reports on the analytical properties and structure elucidation of four cannabimimetic derivatives in seized material: 1-benzyl-N-(1-carbamoyl-2,2-dimethylpropan-1-yl)-1H-indole-3-carboxamide (ADB-BICA, 1), N-(1-carbamoylpropan-1-yl)-1-(5-fluoropentyl)-1H-pyrrolo[2,3-b]pyridine-3-carboxamide (NNL-1, 2), (4-benzylpiperazin-1-yl)(1-(5-fluoropentyl)-1H-indol-3-yl)methanone (NNL-2, 3), and N-(1-carbamoyl-2-phenylethyl)-1-(5-fluoropentyl)-1H-indazole-3-carboxamide (PPA(N)-2201, 4). The identifications were based on liquid chromatography-quadrupole-time-of-flight-mass spectrometry (LC-QTOF-MS), gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance (NMR) spectroscopy. No chemical or pharmacological data about compounds 1-3 have appeared until now, making this the first report on these compounds. The GC-MS data of 4 has been reported, but this study added the LC-MS, FT-IR, and NMR data for additional characterization. Copyright © 2016 John Wiley & Sons, Ltd.

Four types of cannabimimetic indazole and indole derivatives, ADB-BINACA, AB-FUBICA, ADB-FUBICA, and AB-BICA, identified as new psychoactive substances.

We identified four cannabimimetic indazole and indole derivatives in new illegal psychoactive substances seized from a clandestine laboratory in China. These four derivatives included N-(1-amino-3,3-dimethyl-1-oxobutan-2-yl)-1-benzyl-1H-indazole-3-carboxamide (ADB-BINACA, 1), N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-(4-fluorobenzyl)-1H-indole-3-carboxamide (AB-FUBICA, 2), N-(1-amino-3,3-dimethyl-1-oxobutan-2-yl)-1-(4-fluorobenzyl)-1H-indole-3-carboxamide (ADB-FUBICA, 3), and N-(1-amino-3-methyl-1-oxobutan-2-yl)-1-benzyl-1H-indole-3-carboxamide (AB-BICA, 4). These compounds were identified by liquid chromatography-high-resolution mass spectrometry, gas chromatography-mass spectrometry, and nuclear magnetic resonance spectroscopy. No chemical or pharmacological data about compound 4 has appeared until now, making this the first report on this compound. Compounds 1, 2, and 3 have previously been reported to have a high affinity for cannabinoid CB1 and CB2 receptors, but this is the first report of their presence in illegal products.

[Longitudinal analysis of technical efficiency of voluntary counseling and testing of HIV in China].

OBJECTIVE: To longitudinally analyze the unit costs and technical efficiency of human immunodeficiency virus (HIV) voluntary counseling and testing in China. METHODS: Unit costs were calculated by the province and period using longitudinal data from 7 provinces covered by Global Fund China AIDS Program Round 3, and then technical efficiency and Malmquist indices were measured with an approach to data envelopment analysis. RESULTS: The unit costs for HIV voluntary counseling and testing changed dramatically over a 3(+)-year period, decreasing from 165.97 Yuan (mean) to 53.41 Yuan, with an accumulative unit cost of 67.19 Yuan, and its technical efficiency was averaging between 0.44 and 0.63. CONCLUSION: The time series of unit costs for HIV voluntary counseling and testing formed a U-shape curve with an inflection point before which unit costs dramatically dropped and another inflection point beyond which unit costs went up. These findings can inform program managers of the changing unit costs when extending or expanding HIV prevention efforts.

Rhodamine thiospirolactone. Highly selective and sensitive reversible sensing of Hg(II).

A novel rhodamine thiospirolactone chemosensor was found to develop prominent absorbance and fluorescence enhancements in the presence of Hg(2+) in aqueous solution and this was suggested to result from the thiospiro ring opening induced by Hg(2+) binding.

Switching the recognition preference of rhodamine B spirolactam by replacing one atom: design of rhodamine B thiohydrazide for recognition of Hg(II) in aqueous solution.

A new chemosensor based on rhodamine B thiohydrazide is described. Chemosensor B was found to show a reversible dual chromo- and fluorogenic response toward Hg2+ in aqueous solution in a highly selective and sensitive manner. This was suggested to result from the coordination of Hg2+ at the N, S binding sites in B to open its spiro ring.

The effect of folic acid on the development of stomach and other gastrointestinal cancers.

OBJECTIVE: To evaluate the roles of folic acid and beta-carotene in the chemoprevention of gastric and other gastrointestinal (GI) cancers. METHODS: In a randomized, double-blind, placebo-controlled trial, a total of 216 patients with atrophic gastritis were randomly assigned to one of the four groups: (1) folate (FA, 20 mg per day plus vitamin B(12) 1 mg, intramuscularly, per month for one year, then 20 mg two times a week plus 1 mg per three months for the next year); (2) natural beta-carotene (N-betaC, 30 mg per day for first year, then 30 mg two times a week for the next); (3) synthetic beta-carotene (S-betaC, administered as in N-betaC); and (4) placebo. Follow-ups continued from 1994 to 2001. RESULTS: A total of 7 new cases of gastrointestinal cancers were diagnosed with 3 stomach, 1 colon and 1 esophageal cancers occurring in the placebo group; 1 stomach cancer in both of the N-betaC and S-betaC groups, and no cancer occurring in FA group. In terms of GI cancers, there was a significant reduction in the FA group, compared with the placebo group (P = 0.04). A similar trend was observed in both N-betaC and S-betaC groups (P = 0.07 - 0.08). Taken together, the three intervention groups displayed a highly significant decrease in occurrence (P = 0.004, vs placebo), and a lower risk for GI cancers (OR = 0.12; 95% confidence interval, 0.03 - 0.51). For development of gastric cancer, any one of the three active-treated groups did not reach statistically significant reduction. The FA group showed obvious improvement of the gastric mucosal lesions with more patients displaying lesions reversed or stable atrophy and inflammation (P = 0.04), reversed intestinal metaplasia (P = 0.06) at the end of follow-up, and reversed displasia (P = 0.017) at 12 months. Two cases of false jaundice were found in beta-carotene groups with no influence on administration, and no side-effects were reported in FA group. CONCLUSIONS: This trial revealed the interventional effect of folic acid on the development of GI cancers, a similar effect of beta-carotene was also detected. Also, folic acid may be of use to treat atrophic gastritis by preventing or reversing the precancerous lesions.