Alcohol use disorders, nicotine dependence, and co-occurring mood and anxiety disorders in the United States and South Korea-a cross-national comparison.

BACKGROUND: The strong comorbidity between substance use disorders (SUDs) and mood and anxiety disorders has been well documented. In view of lack of research findings addressing the co-occurrence of SUDs and mood and anxiety disorders, this study examined the pattern of comorbidity of alcohol use disorders (AUDs) and nicotine dependence (ND) between 2 culturally diverse countries, the United States and South Korea. METHODS: Using the nationally representative samples of the U.S. and Korean general populations, we directly compared rates and comorbidity patterns of AUDs, ND, and mood and anxiety disorders between the 2 countries. We further examined the rates and the comorbidity pattern among individuals with AUDs who sought treatment in the last 12 months. Twelve-month prevalence rates were derived to estimate country differentials, and odds ratios (ORs) and 95% confidence intervals were estimated to measure the strength of comorbid associations while adjusting for all sociodemographic characteristics in multivariate logistic models specific to each country. RESULTS: The 12-month prevalence rates of AUDs, ND, and any mood disorder and any anxiety disorder were 9.7, 14.4, 9.5, and 11.9% among Americans, whereas the corresponding rates were 7.1, 6.6, 2.0, and 5.2% among Koreans. These rates were significantly greater (except for any AUD) among Americans than among their Korean counterparts. With respect to comorbidity, both countries showed comparable patterns that the prevalence rates of mood and anxiety disorders were consistently the highest among persons with alcohol dependence (AD). Also, a disparate pattern was observed in Korea that the prevalence rates of mood and anxiety disorders were generally lower among individuals with ND than among those with alcohol abuse and AD. Furthermore, despite significantly greater prevalence of AD in Korea (5.1%) than in the United States (4.4%), alcohol-dependent Americans were 4 times (OR = 3.93) more likely to seek treatment compared to their Korean counterparts. CONCLUSIONS: Our results indicated that the prevalence of AD in Korea was substantially greater than that in both Western and other Asian countries, suggesting a maladaptive pattern of alcohol use in Korea, which is different from the general use pattern of other East Asian countries. The low rate of treatment utilization among Koreans might be attributable to perceived social stigma toward SUDs or mental health problems despite the fact that the Korean government offers national health insurance.

Electrochemical characteristics of ultramicro-dimensioned SIROF electrodes for neural stimulation and recording.

OBJECTIVE: With ever increasing applications of neural recording and stimulation, the necessity for developing neural interfaces with higher selectivity and lower invasiveness is inevitable. Reducing the electrode size is one approach to achieving such goals. In this study, we investigated the effect of electrode geometric surface area (GSA), from 20 µm2 to 1960 µm2, on the electrochemical impedance and charge-injection properties of sputtered iridium oxide (SIROF) coated electrodes in response to current-pulsing typical of neural stimulation. These data were used to assess the electrochemical properties of ultra-small SIROF electrodes (GSA < 200 µm2) for stimulation and recording applications. APPROACH: SIROF charge storage capacities (CSC), impedance, and charge-injection characteristics during current-pulsing of planar, circular electrodes were evaluated in an inorganic model of interstitial fluid (model-ISF). MAIN RESULTS: SIROF electrodes as small as 20 µm2 could provide 1.3 nC/phase (200 µs pulse width, 0.6 V versus Ag|AgCl interpulse bias) of charge during current pulsing. The 1 kHz impedance of all electrodes used in this study were below 1 MΩ, which is suitable for neural recording. SIGNIFICANCE: Ultra-small SIROF electrodes are capable of charge injection in buffered saline at levels above some reported thresholds for neural stimulation with microelectrodes.

Ionic cellulose-stabilized gold nanoparticles and their application in the catalytic reduction of 4-nitrophenol.

A novel strategy for the synthesis of highly stable gold nanoparticles (GNPs) was designed by reducing HAuCl4 with NaBH4 in an aqueous solution of water-soluble ionic cellulose composed of dimethylimidazolium cations and phosphite-bound cellulose anions. NMR and UV-Vis analysis along with the measurement of the zeta potential suggest that the exceptionally high stability of GNPs originates from the strong interaction of GNPs with the phosphite groups of the ionic cellulose. The thus prepared GNPs exhibit excellent catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol, a model hydrogenation reaction.

Isolevuglandins as a gauge of lipid peroxidation in human tumors.

The cellular production of free radicals or reactive oxygen species (ROS) can lead to protein, lipid or DNA modifications and tumor formation. The cellular lipids undergo structural changes through the actions of enzymes (e.g. cyclooxygenases) or free radicals to form a class of compounds called Isolevuglandins (IsoLGs). The recruitment and continued exposure of tissue to ROS and IsoLGs causes increased cell proliferation, mutagenesis, loss of normal cell function and angiogenesis. The elevated concentration of ROS in cancerous tissues suggests that these mediators play an important role in cancer development. We hypothesized that tumors with elevated ROS levels would similarly possess an increased concentration of IsoLGs when compared with normal tissue. Using D11, an ScFv recombinant antibody specific for IsoLGs, we utilized immunohistochemistry to visualize the presence of IsoLG in human tumors compared to normal adjacent tissue (NAT) to the same tumor. We found that IsoLG concentrations were elevated in human breast, colon, kidney, liver, lung, pancreatic and tongue tumor cells when compared to NAT and believe that IsoLGs can be used as a gauge indicative of lipid peroxidation in tumors.

Cavities of alpha(1)-antitrypsin that play structural and functional roles.

The native form of inhibitory serine protease inhibitors (serpins) is strained, which is critical for their inhibitory activity. Previous studies on stabilizing mutations of alpha(1)-antitrypsin, a prototype of serpins, indicated that cavities provide a structural basis for the native strain of the molecule. We have systematically mapped the cavities of alpha(1)-antitrypsin that play such structural and functional roles by designing cavity-filling mutations at residues that line the walls of the cavities. Results show that energetically unfavorable cavities are distributed throughout the alpha(1)-antitrypsin molecule, and the cavity-filling mutations stabilized the native conformation at 8 out of 10 target sites. The stabilization effect of the individual cavity-filling mutations of alpha(1)-antitrypsin varied (0.2-1.9 kcal/mol for each additional methylene group) and appeared to depend largely on the structural flexibility of the cavity environment. Cavity-filling mutations that decreased inhibitory activity of alpha(1)-antitrypsin were localized in the loop regions that interact with beta-sheet A distal from the reactive center loop. The results are consistent with the notion that beta-sheet A and the structure around it mobilize when alpha(1)-antitrypsin forms a complex with a target protease.

The human PTFgamma/SNAP43 gene: structure, chromosomal location, and identification of a VNTR in 5'-UTR.

PTF/SNAPc is a multisubunit complex which specifically recognizes the PSEs of small nuclear RNA genes and activates transcription by RNA polymerase II or III. Here we describe the isolation and characterization of genomic clones encoding the human PTFgamma/SNAP43 gene. The gene spans approximately 29 kilobases, and is composed of 9 exons and 8 introns. A major transcription initiation site was identified at the position 58 base pairs upstream of the AUG translation initiator codon on primer extension analysis with HeLa mRNA. The 5' flanking region lacks a typical TATA box but contains many putative binding sites for various transcription factors, such as Sp1, Oct1, NF1, AP1, E2F, and USF. Immediately downstream of the transcription start site, we found a VNTR of a 17-bp sequence rich in (G+C). Four different alleles with two to five copies of the tandem repeat were identified in 10 individuals examined, indicating a high degree of variation at the PTFgamma/SNAP43 locus. In addition, the PTFgamma/SNAP43 gene was mapped to human chromosome 14q22 by fluorescence in situ hybridization.

Total synthesis of the immunosuppressant FR901483 via an amidoacrolein cycloaddition.

[reaction: see text]. The total synthesis of the potent immunosuppressant FR901483 is described. In a key step, the intermolecular Diels-Alder cycloaddition of an amidoacrolein with 2-(triisopropylsilyloxy)-1,3-butadiene produced the desired 3-cyclohexene-1-carboxaldehyde. This compound was subjected to basic followed by acidic conditions which effected two sequential aldol cyclizations to deliver the tricyclic ring system of the natural product, suitably functionalized for completion of the total synthesis.

Time-lapse, single cell based confocal imaging analysis of caspase activation and phosphatidylserine flipping during cellular apoptosis.

Apoptosis is an important phenomenon for investigating the efficacy of anti-cancer drug candidates. The conventional assays for cellular apoptosis, such as enzyme-linked immunosorbent assay, absorbance monitoring for the activity of caspase, and flow cytometric assay, have focused only on biochemical events. We investigated the staurosporine (STS)-induced apoptosis of the murine macrophage RAW-264.7 cell using a cell based bioimaging technique. Using time-lapse confocal microscopy, we monitored caspase-3 activation during apoptosis by imaging the translocation of green fluorescent protein from the cytosol to the nuclei. Five hours after 1 µM STS treatment, caspase-3 was observed to be activated and membrane blebbing was observed simultaneously. Also, the loss of phosphatidylserine (PS) asymmetry in the phospholipid bilayer of plasma membrane during early apoptosis was monitored by imaging annexin-V labeled with fluorescein isocyanate binding to the externalized PS at various concentrations of STS. Moreover, disintegration of the plasma membrane during late apoptosis was confirmed using a nuclear dye, propidium iodide. The single cell based bioimaging data agreed well with those of the biochemical assays for caspase activation and morphological observation for membrane integrity.

Isolation and characterization of a novel oxygenase that catalyzes the first step of n-alkane oxidation in Acinetobacter sp. strain M-1.

In the Finnerty pathway for n-alkane, oxidation in Acinetobacter sp., n-alkanes are postulated to be attacked by a dioxygenase and the product, n-alkyl hydroperoxide, is further metabolized to the corresponding aldehyde via the peroxy acid [W. R. Finnerty, P. 184-188, in A. H. Applewhite (ed.), Proceedings of the World Conference on Biotechnology for the Fats and Oil Industry, 1988]. However, no biochemical evidence regarding the first-step reaction is available. In this study, we found a novel n-alkane-oxidizing enzyme that requires only molecular oxygen, i.e., not NAD(P)H, in our isolate, Acinetobacter sp. strain M-1, and purified it to apparent homogeneity by gel electrophoresis. The purified enzyme is a homodimeric protein with a molecular mass of 134 kDa, contains 1 mol of flavin adenine dinucleotide per mol of subunit, and requires CU2+ for its activity. The enzyme uses n-alkanes ranging in length from 10 to 30 carbon atoms and is also active toward n-alkenes (C12 to C20) and some aromatic compounds with substituted alkyl groups but not toward a branched alkane, alcohol, or aldehyde. Transient accumulation of n-alkyl hydroperoxide was detected in the course of the reaction, and no oxygen radical scavengers affected the enzyme activity. From these properties, the enzyme is most probably a dioxygenase that catalyzes the introduction of two atoms of oxygen to the substrate, leading to the formation of the corresponding n-alkyl hydroperoxide. The enzymatic evidence strongly supports the existence of an n-alkane oxidation pathway, which is initiated by a dioxygenase reaction, in Acinetobacter spp.

Enzyme-assisted asymmetric total synthesis of (-)-podophyllotoxin and (-)-picropodophyllin.

Described is the first catalytic, asymmetric synthesis of (-)-podophyllotoxin and its C(2)-epimer, (-)-picropodophyllin. Asymmetry is achieved via the enzymatic desymmetrization of advanced meso diacetate 20, through PPL-mediated ester hydrolysis. A second key feature of the synthesis is the strategically late introduction of the highly oxygenated natural ring E through an arylcopper species. The successful implementation of this approach augers well for the introduction of other functionalized rings E for future SAR work. The synthesis begins from piperonal, which is fashioned into isobenzofuran (IBF) precursor 14 in three steps (bromination, acetalization, and halogen-metal exchange/hydroxymethylation). Interestingly, treatment of 14 with HOAc in commerical dimethyl maleate (contains 5% dimethyl fumarate) leads to a nearly equimolar mixture of fumarate- (15) and maleate-IBF Diels-Alder adducts (16 and 17), indicating that IBF 11 reacts about 15 times faster with dimethyl fumarate than with dimethyl maleate. With scrupulously pure dimethyl maleate a 2.8:1 endo:exo mixture of maleate DA adducts is still obtained. On the other hand, the desired meso diester 16 is obtained pure and in nearly quantitative yield by employing neat dimethyl acetylene dicarboxylate as the dienophile, followed by catalytic hydrogenation. Reduction (LiAlH(4)) of 16 provides meso diol 19, which is then treated with Ac(2)O, BzCl, and PhCH(2)COCl to provide the corresponding meso diesters, 20-22. Screening of these meso benzoxabicyclo[2.2.1]heptyl substrate candidates across a battery of acyl transfer enzymes leads to an optimized match of diacetate 20 with PPL. Even on 10-20 g scales, asymmetry is efficiently introduced here, yielding the key chiral intermediate, monoacetate 25 (66% isolated yield, 83% corrected yield, 95% ee). Protecting group manipulation and oxidation (Swern) provide aldehyde 27b, which undergoes efficient retro-Michael ring opening to produce dihydronaphthalene 30, in which the C(3) and C(4) stereocenters are properly set. Following several unsuccessful approaches to the intramolecular delivery of ring E (via Claisen rearrangement, Heck-type cyclization, or radical cyclization), a highly diastereoselective, intermolecular conjugate addition of the arylcopper reagent derived from (3,4,5-trimethoxy)phenylmagnesium bromide and CuCN to acyl oxazolidinone 50 was developed (85% yield, only the required alpha-stereochemistry at C(1) is observed). The conjugate addition product is converted to (-)-picropodophyllin in two steps (lactonization, SEM deprotection) or to (-)-podophyllotoxin, in three steps, through the introduction of a C(2)-epimerization step, under Kende conditions, prior to the final conjugate addition.

Use of microorganism-immobilized polyurethane foams to absorb and degrade oil on water surface.

Highly oil-absorbent polyurethane foam (PUF) materials were obtained by polymerizing polyether polyol mixture and carbodiimide-modified D-methyl diisocyanate in a weight ratio of 10:2. The foam materials were prepared to contain inorganic nutrients (slow-release fertilizer; SRF) and oil-degrading yeast cells, Yarrowia lipolytica 180, to be applied for removal of oil films on surface waters through absorption and biodegradation after oil spills. PUFs absorbed 7-9 times their own weight of Arabian light crude oil and the oil absorbency appeared to improve as the ratio of surface area to foam weight increased. PUFs showed excellent floatability which was maintained for more than 6 months in sea water, and less than 5% of the absorbed oil was released when the foams were left on water for more than 10 days. For immobilization of yeast cells into PUFs, various immobilization techniques were tested to compare their oil degrading ability and the maintenance thereof. All immobilized cells showed oil degrading abilities as good as those of free cells immediately after the preparation of PUFs, however, the activity of chitin-immobilized cells remained at a high level for the longest period of preservation. The high efficiency of oil absorption and oil degradation by PUF-immobilized yeast cells suggested that PUF-immobilized cells have a high potential as a bioremediation technique for the treatment of oil films on surface waters.

Distribution of the native strain in human alpha 1-antitrypsin and its association with protease inhibitor function.

Serine protease inhibitors (serpins) are metastable in their native state. This strain, which is released upon binding to target proteases, is essential for the inhibitory activity of serpins. To understand the structural basis of the native strain, we previously characterized stabilizing mutations of alpha(1)-antitrypsin, a prototypical inhibitory serpin, in regions such as the hydrophobic core. The present study evaluates the effects of single point mutations throughout the molecule on stability and protease inhibitory activity. We identified stabilizing mutations in most secondary structures, suggesting that the native strain is distributed throughout the molecule. Examination of the substitution patterns and the structures of the mutation sites revealed surface hydrophobic pockets as a component of the native strain in alpha(1)-antitrypsin, in addition to the previously identified unusual interactions such as side chain overpacking and cavities. Interestingly, many of the stabilizing substitutions did not affect the inhibitory activity significantly. Those that affected the activity were confined in the regions that are mobilized during the complex formation with a target enzyme. The results of our study should be useful for designing proteins with strain and for regulating the stability and functions of serpins.

Single electron transfer by an extracellular laccase from the white-rot fungus Pleurotus ostreatus.

Two different bands with laccase activity were obtained after nondenaturing PAGE of the culture filtrate of Pleurotus ostreatus. Immunoblot analysis revealed that antisera raised against laccase I were not reactive to laccase II. Laccase I, which exhibited faster mobility on nondenaturing polyacrylamide gel, was purified 42.9-fold with an overall yield of 10.8%. Gel filtration and SDS-PAGE revealed that laccase I is a single polypeptide with a molecular mass of approximately 64 kDa. Laccase I contained 12.5% carbohydrate by weight and 3.9 mol copper (mol protein)-1. The absorption spectrum of laccase I showed a type 1 signal at 605 nm and EPR spectra showed that the parameters of the type 1 and type 2 Cu signals were g parallel = 2.197 and A parallel = 0.009 cm-1, and g parallel = 2.263 and A parallel = 0.0176 cm-1, respectively. The data obtained from the pH profiles suggested that two ionization groups, whose pKa values were 5.60-5.70 and 6.70-6.85, may play an important role in the active site of laccase I as the ligand of copper metal. The optimal pH and temperature for the activity of laccase I were 6.0-6.5 and 30-35 degrees C, respectively. The enzyme had affinity for various lignin-related phenolic compounds: the Km values for ferulic acid and syringic acid were 48 and 89 microM, respectively. EPR spectroscopic study of the action of laccase I on 3,5-dimethoxy-5-hydroxyacetophenone indicated that this enzyme catalyses single electron transfer with the formation of the phenoxy radical as an intermediate.