Simultaneous analysis of Δ(9)-tetrahydrocannabinol and 11-nor-9-carboxy-tetrahydrocannabinol in hair without different sample preparation and derivatization by gas chromatography-tandem mass spectrometry.

The present study describes a gas chromatography/tandem mass spectrometry-negative ion chemical ionization assay (GC/MS/MS-NCI) for simultaneous analysis of Δ(9)-tetrahydrocannabinol (THC) and 11-nor-9-carboxy-tetrahydrocannabinol (THCCOOH) in hair. Each hair sample, of approximately 20mg, was weighed and the sample was dissolved in 1ml of 1M sodium hydroxide (30min at 85°C) in the presence of THC-d(3) and THCCOOH-d(3). For the analysis of THC, hair samples were extracted with n-hexane:ethyl acetate (9:1) two times; acetic acid and sodium acetate buffer were added for the analysis of THCCOOH, and hair samples were re-extracted with n-hexane:ethyl acetate (9:1) two times.

Development of high-throughput phosphorylation profiling method for identification of Ser/Thr kinase specificity.

Identification of substrate specificity of kinases is crucial to understand the roles of the kinases in cellular signal transduction pathways. Here, we present an approach applicable for the discovery of substrate specificity of Ser/Thr kinases. The method, which is named as the 'high-throughput phosphorylation profiling (HTPP)' method was developed on the basis of a fully randomized one-bead one-compound (OBOC) combinatorial ladder type peptide library and MALDI-TOF MS.

Phenotypes associated with Saccharomyces cerevisiae Hug1 protein, a putative negative regulator of dNTP Levels, reveal similarities and differences with sequence-related Dif1.

Saccharomyces cerevisiae Hugl is a small protein of unknown function that is highly inducible following replication stress and DNA damage. Its deletion suppresses the lethality of deletion of checkpoint kinase Mecl. Although DNA damage responses were largely normal in the HUG1 deletion mutant, we found enhanced resistance towards heat in logarithmic phase.

Oleyl-chitosan nanoparticles based on a dual probe for optical/MR imaging in vivo.

Oleic acid-conjugated chitosan (oleyl-chitosan) is a powerful platform for encapsulating oleic acid-decorated iron oxide nanoparticles (ION), resulting in a good magnetic resonance imaging (MRI) probe. Oleyl-chitosan could self-assemble into core-shell structures in aqueous solution and provide the effective core compartment for loading ION. ION-loaded oleyl-chitosan nanoparticles showed good enhanced MRI sensitivity in a MR scanner.

Different genetic effect of PXK on systemic lupus erythematosus in the Korean population.

PXK was identified as a novel candidate gene for systemic lupus erythematosus (SLE) from genome-wide association studies (GWAS) in Caucasians. But a recent replication study in Hong Kong Chinese reported that PXK was not associated with SLE. The aim of this study was to determine whether PXK is associated with SLE in Koreans.

Evaluation of the therapeutic efficacy of a VEGFR2-blocking antibody using sodium-iodide symporter molecular imaging in a tumor xenograft model.

Purpose: Vascular endothelial growth factor receptor 2-blocking antibody (DC101) has inhibitory effects on tumor growth and angiogenesis in vivo. The human sodium/iodide symporter (hNIS) gene has been shown to be a useful molecular imaging reporter gene. Here, we investigated the evaluation of therapeutic efficacy by molecular imaging in reporter gene transfected tumor xenografts using a gamma imaging system.

Establishment of the measurement uncertainty of 11-nor-D9-tetrahydrocannabinol-9-carboxylic acid in hair.

The quantitative analysis of 11-nor-D(9)-tetrahydrocannabinol-9-carboxylic acid (THCCOOH) in hair requires a sensitive method to detect a low-pg level. Before applying the method to real hair samples, the method was validated; in this study, we examined the uncertainty obtained from around the cut-off level of THCCOOH in hair. We calculated the measurement uncertainty (MU) of THCCOOH in hair as follows: specification of the measurand, identification of parameters using "cause and effect" diagrams, quantification of the uncertainty contributions using three factors, the uncertainty of weighing the hair sample, the uncertainty from calibrators and the calibration curve, and the uncertainty of the method precision.

Simultaneous quantification of opiates and effect of pigmentation on its deposition in hair.

In forensic toxicology, the abuse of various opiate preparations, such as raw opium and heroin, is of interest since the metabolic pathways of these opiates overlap. Although the pharmaco(toxico)kinetics in hair is not clearly understood, melanin is thought to play a key part in the incorporation and distribution of drugs and metabolites in hair. Therefore, in the present study, a simultaneous quantification method for the determination of codeine, morphine, norcodeine, normorphine and 6-acetylmorphine (6-AM) in hair was developed in order to analytically diagnose chronic users of opiates including morphine and codeine preparations, raw opium and heroin.

Synthesis of N₄'-[¹⁸F]fluoroalkylated ciprofloxacin as a potential bacterial infection imaging agent for PET study.

Syntheses and evaluation of fluoroalkylated ciprofloxacin analogues are described. Among these analogues, N₄'-3-fluoropropylciprofloxacin (16) showed the most efficient antibacterial activity against E. coli strains (DH5α and TOP10) and a high binding affinity for DNA gyrase of bacteria.

The dependence of the incorporation of methamphetamine into rat hair on dose, frequency of administration and hair pigmentation.

In this paper, the incorporation of methamphetamine (MA) into rat hair was studied. The main purpose of this study was to investigate whether MA can be detected or positive hair results can be obtained in hair of rats administered a single dose of MA. The relationship between dose and frequency of administration and the concentrations of MA and its metabolite, amphetamine (AP), in rat hair were evaluated and the MA and AP concentrations in white and pigmented hair were compared.

Differentiation of human embryonic stem cells into hematopoietic cells in vitro.

The ability of embryonic stem cells (ES) cells to form cells and tissues from all three germ layers can be exploited to generate cells that can be used to treat diseases. In particular, successful generation of hematopoietic cells from ES cells could provide safer and less immunogenic cells than bone cells, obviating the need for severe host preconditioning when transplanted across major histocompatibility complex barriers. To generate hematopoietic stem cells, protocols utilizing embryoid body (EB)-induced differentiation of human ES (hES) cells have been applied in the authors' laboratory.

Characterization and structure identification of an antimicrobial peptide, hominicin, produced by Staphylococcus hominis MBBL 2-9.

Hominicin, antimicrobial peptide displaying potent activity against Staphylococcus aureus ATCC 25923, methicillin-resistant S. aureus (MRSA) ATCC 11435 and vancomycin-intermediate S. aureus (VISA) CCARM 3501, was purified by chloroform extraction, ion-exchange column chromatography and reverse-phase HPLC from culture supernatant of Staphylococcushominis MBBL 2-9.

Homogeneity and stability of a candidate certified reference material for the determination of methamphetamine and amphetamine in hair.

In the preparation of a reference material (RM) for quality assurance, both homogeneity and stability studies are integral parts. In the present study, both homogeneity and stability of a candidate RM for the determination of methamphetamine and amphetamine in hair were examined by an isotope dilution gas chromatography/mass spectrometry (GC/MS) method, which is not only one of the analytical methods validated in our previous study but also one of the primary methods for the preparation of a certified reference material (CRM). Additionally, homogeneity was monitored using a different method: micropulverized extraction followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), which was fully validated in the previous study.

Surface engineering of quantum dots for in vivo imaging.

The aim of this study was to investigate the effect of gluconic acid (GA) conjugation on the biodistribution of cysteamine-capped quantum dots (amino-QDots) in vivo. Cadmium selenide/zinc sulfide (CdSe/ZnS) was capped with cysteamine through a thiol exchange method, and different amounts of GA were conjugated to the amine groups of cysteamine via the formation of an amide bond. The emission maxima of the synthesized QDots, the amino-QDots and the GA-conjugated amine-QDots (GA-QDots) were located at 720, 600 and 610 nm, respectively.

Synthesis of Tc-99m labeled 1,2,3-triazole-4-yl c-met binding peptide as a potential c-met receptor kinase positive tumor imaging agent.

The mesenchymal-epithelial transition factor (c-Met), which is related to tumor cell growth, angiogenesis and metastases, is known to be overexpressed in several tumor types. In this study, we synthesized technetium-99m labeled 1,2,3-triazole-4-yl c-Met binding peptide (cMBP) derivatives, prepared by solid phase peptide synthesis and the 'click-to-chelate' protocol for the introduction of tricarbonyl technetium-99m, as a potential c-Met receptor kinase positive tumor imaging agent, and evaluated their in vitro c-Met binding affinity, cellular uptake, and stability. The (99m)Tc labeled cMBP derivatives ([(99m)Tc(CO)(3)]12, [(99m)Tc(CO)(3)]13, and [(99m)Tc(CO)(3)]14) were prepared in 85-90% radiochemical yields.

Estimation of the measurement uncertainty by the bottom-up approach for the determination of methamphetamine and amphetamine in urine.

The measurement uncertainty (MU) of methamphetamine (MA) and amphetamine (AP) was estimated in an authentic urine sample with a relatively low concentration of MA and AP using the bottom-up approach. A cause and effect diagram was deduced; the amount of MA or AP in the sample, the volume of the sample, method precision, and sample effect were considered uncertainty sources. The concentrations of MA and AP in the urine sample with their expanded uncertainties were 340.

Distal cholangiocarcinoma with gastric metastasis mimicking early gastric cancer.

We report an unusual case of distal cholangiocarcinoma with gastric metastasis mimicking early gastric cancer. A 67-year-old woman presented with a 4-month history of abdominal pain after eating. Computed tomography showed a malignant tumor of the common bile duct located just above the intrapancreatic segment, and endoscopy revealed a 2-cm, flat, elevated lesion with convergence of the surrounding folds, situated at the gastric angle.

Galactosylated chitosan-g-PEI/DNA complexes-loaded poly(organophosphazene) hydrogel as a hepatocyte targeting gene delivery system.

Hydrogels are widely used in drug delivery systems because they can control the release and thereby enhance the efficiency of locally delivered bioactive molecules such as therapeutic drugs, proteins, or genes. For gene delivery, localized release of plasmid DNA or polymer/DNA complexes can transfect cells and produce sustained protein production. We tested the galactosylated chitosan-graft-polyethylenimine (GC-g-PEI)/DNA complexes-loaded poly(organophosphazene) thermosensitive biodegradable hydrogel as a hepatocyte targeting gene delivery system.

Prostate cancer-targeted imaging using magnetofluorescent polymeric nanoparticles functionalized with bombesin.

Purpose: In this work, the aim was to prepare and characterize a magnetofluorescent polymeric nanoparticle for prostate cancer imaging in vivo.

Methods: Glycol chitosan (GC) was chemically modified with N-acetyl histidine (NAHis) as a hydrophobic moiety, and bombesin (BBN) was conjugated to the hydrophobically modified GC for use in targeting gastric-releasing peptide receptors (GRPR) overexpressed in prostate cancer cells. NAHis-GC conjugates were labeled with the near-infrared (NIR) fluorophore Cy5.

Paenibacillus pini sp. nov., a cellulolytic bacterium isolated from the rhizosphere of pine tree.

Strain S22(T), a novel cellulolytic bacterium was isolated from the rhizosphere of pine trees. This isolate was Gram-reaction positive, motile and rods, and formed terminal or subterminal ellipsoidal spores. S22(T) represented positive activity for catalase, oxidase, esterase (C4), esterase lipase (C8), beta-galactosidase, leucine arylamidase, and hydrolysis of esculin.

Analysis of cannabis in oral fluid specimens by GC-MS with automatic SPE.

Methamphetamine (MA) is the most commonly abused drug in Korea, followed by cannabis. Traditionally, MA analysis is carried out on both urine and hair samples and cannabis analysis in urine samples only. Despite the fact that oral fluid has become increasingly popular as an alternative specimen in the field of driving under the influence of drugs (DUID) and work place drug testing, its application has not been expanded to drug analysis in Korea.

Superparamagnetic iron oxide nanoparticles as a dual imaging probe for targeting hepatocytes in vivo.

Hepatocyte-specific targeting agents are useful for evaluation of the hepatocytic function and the monitoring of disease progress. Superparamagnetic iron oxide nanoparticles (SPION) bearing terminal galactose groups exhibit a high affinity for the asialoglycoprotein receptor on the hepatocyte surface. In this study, we synthesized and characterized the dual probe SPION detectable by both nuclear and MR imaging modality for specifically targeting hepatocytes in vivo.

Paenibacillus pinihumi sp. nov., a cellulolytic bacterium isolated from the rhizosphere of Pinus densiflora.

A novel cellulolytic bacterium, strain S23(T), was isolated from the rhizosphere of the pine trees in Daejeon, Republic of Korea. This isolate was Gram-positive, strictly aerobic, rod-shaped, catalase-negative, oxidase-positive, motile by means of peritrichous flagella, and tested positive for alkaline phosphatase, esterase lipase, leucine arylamidase, alpha-galactosidase, and beta-galactosidase activities. The DNA G+C content was 49.

Cu2+ ion-induced self-assembly of pyrenylquinoline with a pyrenyl excimer formation.

Synthesis of a novel pyrene derivative sensor (1) and its intermolecular binding pattern to Cu(2+) in CH(3)CN were investigated. Upon Cu(2+) binding, the sensor exhibited a strong static excimer emission at 460 nm, along with a weak monomer emission at 388 nm. The excimer emission intensity induced by the Cu(2+) ion declined as the spacer length between the pyrene and quinolinylamide unit increased.