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Topical steroids are used for the treatment of primary atopic dermatitis (AD); however, their associated risk of serious complications is great due to the presence of vulnerable lesions in young children with AD. Topical calcineurin inhibitors (TCIs) are steroid-free, anti-inflammatory agents used for topical AD therapy. However, their use is prohibited in infants <2 years of age because of their carcinogenic potential. We conducted a randomized, double-blind trial to evaluate the efficacy of TCIs as a secondary AD treatment for children <2 years of age by comparing 1% pimecrolimus cream with 0.05% desonide cream. We performed urinary metabolomics to predict long-term side effects. The 1% pimecrolimus cream displayed similar efficacy and exceptional safety compared with the 0.05% desonide cream. Metabolomics-based long-term toxicity tests effectively predicted long-term side effects using short-term clinical models. This applicable method for the functional interpretation of metabolomics data sets the foundation for future studies involving the prediction of the toxicity and systemic reactions caused by long-term medication administration.

Here we report a new and efficient synthetic method for reduced graphene oxide using visible-light and plasmonic nanoparticles at room temperature. The r-GO prepared using visible light showed excellent fluorescence quenching properties and target detection capabilities.

The design, synthesis and control of plasmonic nanostructures, especially with ultrasmall plasmonically coupled nanogap (∼1 nm or smaller), are of significant interest and importance in chemistry, nanoscience, materials science, optics and nanobiotechnology. Here, we studied and established the thiolated DNA-based synthetic principles and methods in forming and controlling Au core-nanogap-Au shell structures [Au-nanobridged nanogap particles (Au-NNPs)] with various interior nanogap and Au shell structures. We found that differences in the binding affinities and modes among four different bases to Au core, DNA sequence, DNA grafting density and chemical reagents alter Au shell growth mechanism and interior nanogap-forming process on thiolated DNA-modified Au core. Importantly, poly A or poly C sequence creates a wider interior nanogap with a smoother Au shell, while poly T sequence results in a narrower interstitial interior gap with rougher Au shell, and on the basis of the electromagnetic field calculation and experimental results, we unraveled the relationships between the width of the interior plasmonic nanogap, Au shell structure, electromagnetic field and surface-enhanced Raman scattering. These principles and findings shown in this paper offer the fundamental basis for the thiolated DNA-based chemistry in forming and controlling metal nanostructures with ∼1 nm plasmonic gap and insight in the optical properties of the plasmonic NNPs, and these plasmonic nanogap structures are useful as strong and controllable optical signal-generating nanoprobes.

With the depletion of global fish stocks, caused by high demand and effective fishing techniques, alternative sources for long chain omega-3 fatty acids are required for human nutrition and aquaculture feeds. Recent research has focused on land-based cultivation of microalgae, the primary producers of omega-3 fatty acids in the marine food web. The effect of salinity on fatty acids and related gene expression was studied in the model marine microalga, Tetraselmis sp. M8. Correlations were found for specific fatty acid biosynthesis and gene expression according to salinity and the growth phase. Low salinity was found to increase the conversion of C18:4 stearidonic acid (SDA) to C20:4 eicosatetraenoic acid (ETA), correlating with increased transcript abundance of the Δ-6-elongase-encoding gene in salinities of 5 and 10 ppt compared to higher salinity levels. The expression of the gene encoding β-ketoacyl-coenzyme was also found to increase at lower salinities during the nutrient deprivation phase (Day 4), but decreased with further nutrient stress. Nutrient deprivation also triggered fatty acids synthesis at all salinities, and C20:5 eicosapentaenoic acid (EPA) increased relative to total fatty acids, with nutrient starvation achieving a maximum of 7% EPA at Day 6 at a salinity of 40 ppt.

Objectives: The aim of this study was to investigate factors associated with sleep disorders in male firefighters working in a metropolitan city in South Korea., Methods: Self-administered questionnaires including the Nordic Musculoskeletal Questionnaire, Korean Occupational Stress Scale-Short Form, Psychosocial Well-Being Index-Short Form, Pittsburg Sleep Quality Index, and Beck-Depression Inventory-2 as well as surveys collecting socio-demographic characteristics and work-related factors were given to 730 male firefighters. After exclusion for missing data, 657 male firefighters were included, and logistic regression analysis adjusted for the work-related factors, psychosocial factors, and general risk factors were used to assess the relationship between sleep disorders and associated factors., Results: The prevalence of sleep disorders was 48.7%. Shift work (adjusted OR 1.58, 95% CI = 1.02-2.45), musculoskeletal symptoms (adjusted OR 2.89, 95% CI = 2.02-4.14), and depression (adjusted OR 7.04 95% CI = 4.03-12.30) were associated with sleep disorders., Conclusions: Musculoskeletal symptoms, shift work, and depression are associated with sleep disorders. Integrated health management is needed to promote good sleep quality among firefighters.

Chemical profiles of medicinal plants could be dissimilar depending on the cultivation environments, which may influence their therapeutic efficacy. Accordingly, the regional origin of the medicinal plants should be authenticated for correct evaluation of their medicinal and market values. Metabolomics has been found very useful for discriminating the origin of many plants. Choosing the adequate analytical tool can be an essential procedure because different chemical profiles with different detection ranges will be produced according to the choice. In this study, four analytical tools, Fourier transform near‑infrared spectroscopy (FT-NIR), 1H-nuclear magnetic resonance spectroscopy (1H‑NMR), liquid chromatography-mass spectrometry (LC-MS), and gas chromatography-mass spectroscopy (GC-MS) were applied in parallel to the same samples of two popular medicinal plants (Gastrodia elata and Rehmannia glutinosa) cultivated either in Korea or China. The classification abilities of four discriminant models for each plant were evaluated based on the misclassification rate and Q2 obtained from principal component analysis (PCA) and orthogonal projection to latent structures-discriminant analysis (OPLS‑DA), respectively. 1H-NMR and LC-MS, which were the best techniques for G. elata and R. glutinosa, respectively, were generally preferable for origin discrimination over the others. Reasoned by integrating all the results, 1H-NMR is the most prominent technique for discriminating the origins of two plants. Nonetheless, this study suggests that preliminary screening is essential to determine the most suitable analytical tool and statistical method, which will ensure the dependability of metabolomics-based discrimination.

Mesenchymal stem cells (MSCs) have been used in a wide range of research and clinical studies because MSCs do not have any ethical issues and have the advantage of low carcinogenicity due to their limited proliferation. However, because only a small number of MSCs can be obtained from the bone marrow, ex vivo amplification is inevitably required. For that reason, this study was conducted to acquire the metabolic information to examine and control the changes in the activities and differentiation potency of MSCs during the ex vivo culture process. Endogenous metabolites of human bone-marrow-derived clonal MSCs (hcMSCs) during cellular senescence were profiled by ultraperformance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/QTOFMS). To select significant metabolites, we used the linear mixed effects model having fixed effects for batch and time (passage) and random effects for metabolites, determining the mean using a t test and the standard deviation using an F test. We used structural analysis with representative standards and spectrum patterns with different collision energies to distinctly identify eight metabolites with altered expression during senescence as types of lysophosphatidylcholine (LPC) and lysophosphatidylethanolamine (LPE), such as LPC 16:0 and LPE 22:4. The present study revealed changes in endogenous metabolites and mechanisms due to senescence.

We report plasmonic gold nanoshells and nanorods coated with reduced graphene oxide that produce an enhanced photothermal effect when stimulated by near-infrared (NIR) light. Electrostatic interactions between nanosized graphene oxide and gold nanoparticles followed by in situ chemical reduction generated reduced graphene oxide-coated nanoparticles; the coating was demonstrated using Raman and HR-TEM. Reduced graphene oxide-coated gold nanoparticles showed enhanced photothermal effect compared to noncoated or nonreduced graphene oxide-coated gold nanoparticles. Reduced graphene oxide-coated gold nanoparticles killed cells more rapidly than did noncoated or nonreduced graphene oxide-coated gold nanoparticles.

Objectives: To compare the risk factors, clinical characteristics, microbiological profile, and treatment outcomes of polymicrobial versus monomicrobial keratitis., Methods: In this retrospective comparative case series, eyes with polymicrobial and monomicrobial keratitis were identified from microbiological records at a tertiary academic referral center, from January 2002 to December 2010. Only culture positive cases were included. Eyes with infectious keratitis involving two or more pathogens were included in the polymicrobial group, whereas eyes infected solely by Pseudomonas aeruginosa were included in the monomicrobial group. Various parameters including demographics, risk factors, clinical and microbiological characteristics, and treatment outcomes were analyzed., Results: Twenty-one eyes each with polymicrobial and monomicrobial keratitis were included in this study. The mean age of polymicrobial patients was significantly higher than monomicrobials. Use of contact lens was the commonest predisposing factor in both groups. Systemic (23.8%) and multiple (33.3%) risk factors were involved in eyes with polymicrobial keratitis only. The mean size of corneal infiltrates and mean duration for resolvement of infection were significantly greater in the polymicrobial group. Medical treatment was successful only in 80.9% eyes with polymicrobial keratitis, whereas all monomicrobial keratitis patients responded to it. A total of 44 organisms belonging to 18 species (bacteria = 13, fungi = 5) were isolated from the polymicrobial group. P. aeruginosa and Candida albicans were the most frequently isolated bacteria (n = 12) and fungi (n = 5), respectively. In the polymicrobial group, gram-negative organisms were most sensitive to gentamicin (87.8%), followed by ciprofloxacin (78.7%), whereas gram-positive organisms were 100% sensitive to ciprofloxacin and cefazolin., Conclusions: A high index of suspicion of polymicrobial keratitis should be made in patients with multiple and systemic risk factors. Contact lens usage was the most common risk factor in both groups. Size of corneal infiltrate is a fairly reliable indicator for suspecting polymicrobial keratitis. Prolonged course of the disease and decreased antibiotic sensitivity were the other notable features of polymicrobial keratitis.

Reactive oxygen and nitrogen species (ROS and RNS) are continuously produced in the cellular systems and are controlled by several antioxidant mechanisms. Here, we developed a straightforward, sensitive, and quantitative assay for the colorimetric and spectroscopic detection of various ROS and RNS such as H2O2, ·OH, (-)OCl, NO·, and O2(-) using glutathione-modified gold nanoparticles (GSH-AuNPs). A basic principle here is that the GSHs on the AuNP surface can be readily detached via the formation of glutathione disulfides upon the addition of ROS and RNS, and destabilized particles can aggregate to generate the plasmonic couplings between plasmonic AuNPs that trigger the red shift in UV-vis spectrum and solution color change. For nonradical species such as H2O2, this process can be more efficiently achieved by converting them into radical species via the Fenton reaction. Using this strategy, we were able to rapidly and quantitatively distinguish among cancerous and normal cells based on ROS and RNS production.

Objective: To report an unusual case of keratitis in a cosmetic contact lens wearer caused by two rare organisms., Method: Case report., Results: A 14-year-old cosmetic contact lens user presented with a paracentral corneal ulcer in her right eye. The cosmetic lenses were bought online. The cultures from corneal scrapings and contact lenses demonstrated heavy growth of Chryseobacterium meningosepticum and Delftia acidovorans. The treatment with topical ciprofloxacin and fortified gentamicin was effective, and the infection resolved with corneal scar after 5 weeks., Conclusion: Use of cosmetic contact lenses and buying them online is a fairly common practice among teenagers. This can lead to serious eye infection as in this case. To our knowledge, this is the first report of contact lens-related keratitis simultaneously involving these two rare organisms.

We extensively study the relationships between single-molecule surface-enhanced Raman scattering (SMSERS) intensity, enhancement factor (EF) distribution over many particles, interparticle distance, particle size/shape/composition and excitation laser wavelength using the single-particle AFM-correlated Raman measurement method and theoretical calculations. Two different single-DNA-tethered Au-Ag core-shell nanodumbbell (GSND) designs with an engineerable nanogap were used in this study: the GSND-I with various interparticle nanogaps from ∼4.8 nm to <1 nm or with no gap and the GSND-II with the fixed interparticle gap size and varying particle size from a 23-30 nm pair to a 50-60 nm pair. From the GSND-I, we learned that synthesizing a <1 nm gap is a key to obtain strong SMSERS signals with a narrow EF value distribution. Importantly, in the case of the GSND-I with <1 nm interparticle gap, an EF value of as high as 5.9 × 10(13) (average value = 1.8 × 10(13)) was obtained and the EF values of analyzed particles were narrowly distributed between 1.9 × 10(12) and 5.9 × 10(13). In the case of the GSND-II probes, a combination of >50 nm Au cores and 514.5 nm laser wavelength that matches well with Ag shell generated stronger SMSERS signals with a more narrow EF distribution than <50 nm Au cores with 514.5 nm laser or the GSND-II structures with 632.8 nm laser. Our results show the usefulness and flexibility of these GSND structures in studying and obtaining SMSERS structures with a narrow distribution of high EF values and that the GSNDs with < 1 nm are promising SERS probes with highly sensitive and quantitative detection capability when optimally designed.

Omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) provide significant health benefits and this has led to an increased consumption as dietary supplements. Omega-3 fatty acids EPA and DHA are found in animals, transgenic plants, fungi and many microorganisms but are typically extracted from fatty fish, putting additional pressures on global fish stocks. As primary producers, many marine microalgae are rich in EPA (C20:5) and DHA (C22:6) and present a promising source of omega-3 fatty acids. Several heterotrophic microalgae have been used as biofactories for omega-3 fatty acids commercially, but a strong interest in autotrophic microalgae has emerged in recent years as microalgae are being developed as biofuel crops. This paper provides an overview of microalgal biotechnology and production platforms for the development of omega-3 fatty acids EPA and DHA. It refers to implications in current biotechnological uses of microalgae as aquaculture feed and future biofuel crops and explores potential applications of metabolic engineering and selective breeding to accumulate large amounts of omega-3 fatty acids in autotrophic microalgae.

Microalgae have been widely reported as a promising source of biofuels, mainly based on their high areal productivity of biomass and lipids as triacylglycerides and the possibility for cultivation on non-arable land. The isolation and selection of suitable strains that are robust and display high growth and lipid accumulation rates is an important prerequisite for their successful cultivation as a bioenergy source, a process that can be compared to the initial selection and domestication of agricultural crops. We developed standard protocols for the isolation and cultivation for a range of marine and brackish microalgae. By comparing growth rates and lipid productivity, we assessed the potential of subtropical coastal and brackish microalgae for the production of biodiesel and other oil-based bioproducts. This study identified Nannochloropsis sp., Dunaniella salina and new isolates of Chlorella sp. and Tetraselmis sp. as suitable candidates for a multiple-product algae crop. We conclude that subtropical coastal microalgae display a variety of fatty acid profiles that offer a wide scope for several oil-based bioproducts, including biodiesel and omega-3 fatty acids. A biorefinery approach for microalgae would make economical production more feasible but challenges remain for efficient harvesting and extraction processes for some species.

Aim: To report the outcome at 5-year follow-up of a defined series of patients with primary periocular basal cell carcinoma treated by cryotherapy using a nitrous oxide probe., Methods: A prospective, non-comparative, interventional case series. One hundred primary periocular basal cell carcinomas were treated with a double freeze-thaw cycle nitrous oxide contact cryotherapy probe. Inclusion criteria were clinically well-defined primary periocular basal cell carcinomas with maximum diameter of 8 mm. The main outcome measure was histologically proven recurrence rate at 5-year follow-up., Results: Kaplan-Meier survival analysis showed a 5-year recurrence rate of 8%. Cox regression analysis revealed no correlation between tumour site, tumour size, cryotherapy freeze time and recurrence (p=0.60, p=0.86 and p=0.71, respectively). Thirty-six per cent of patients were lost to follow-up at 5 years following treatment., Conclusion: The results of this series suggest that nitrous oxide probe cryotherapy for primary periocular basal cell carcinomas up to 8 mm diameter has a recurrence rate of ∼8%. Cryotherapy has certain advantages over surgical removal of tumours of this size in the periocular region, but careful follow-up is advisable.

An ideal surface-enhanced Raman scattering (SERS) nanostructure for sensing and imaging applications should induce a high signal enhancement, generate a reproducible and uniform response, and should be easy to synthesize. Many SERS-active nanostructures have been investigated, but they suffer from poor reproducibility of the SERS-active sites, and the wide distribution of their enhancement factor values results in an unquantifiable SERS signal. Here, we show that DNA on gold nanoparticles facilitates the formation of well-defined gold nanobridged nanogap particles (Au-NNP) that generate a highly stable and reproducible SERS signal. The uniform and hollow gap (∼1 nm) between the gold core and gold shell can be precisely loaded with a quantifiable amount of Raman dyes. SERS signals generated by Au-NNPs showed a linear dependence on probe concentration (R(2) > 0.98) and were sensitive down to 10 fM concentrations. Single-particle nano-Raman mapping analysis revealed that >90% of Au-NNPs had enhancement factors greater than 1.0 × 10(8), which is sufficient for single-molecule detection, and the values were narrowly distributed between 1.0 × 10(8) and 5.0 × 10(9).

A gold nanoparticle-based colorimetric antibody structure and activity evaluation method is developed without using complicated and expensive instrumentation. In this assay, a minimum number of antibodies to stabilize nanoparticles are conjugated to gold nanoparticles to prepare minimally stable nanoparticle probes, and the addition of salt rapidly induced particle aggregation and a color change of the solution from red to blue (25-min assay time). It is found that the solution color change is affected by the degree of structural denaturation of antibodies, and the conformational change of antibodies affects the modification of antibodies to nanoparticles and particle stability. Importantly, the colorimetric method can be applied to different types of antibodies (IgG, IgA, and IgM) and it shows comparable or better structural sensitivity than conventional circular dichroism spectroscopy. Moreover, immunoassay results show that these structural changes of antibodies are highly correlated with their antigen-binding activities. Rapid particle aggregation and high structural sensitivity are achieved in this assay because particles are modified with a minimum number of antibodies to stabilize particles in solution. This nanoparticle-based colorimetric method could be useful in evaluating the structural and activity changes of an array of antibodies in an easy, rapid, and sensitive manner., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Changes in the serotonergic nervous system after the intracerebroventricular (i.c.v.) administration of ethylcholine aziridinium (AF64A, 3 nmol/each ventricle) were studied in rats. Two weeks after the infusion of AF64A, the levels of 5-HT and 5-HIAA in microdialysed cerebrospinal fluid (CSF), the levels of total 5-HT and 5-HIAA, the density of serotonin uptake sites and the activities of tryptophan hydroxylase (TPH) and monoamine oxidase (MAO) in various brain regions were determined. After AF64A administration, the concentrations of 5-HT in lateral ventricle were increased and the levels of 5-HIAA were decreased. However, the hippocampal levels of total 5-HT were decreased without changes in the levels of 5-HIAA and the hippocampal turnover rates of 5-HT increased. Also, the density of uptake sites of serotonin ([(3)H]citalopram binding sites) was decreased in the various brain. The activities of TPH were increased in striatum and frontal cortex and the activity of MAO was also increased in striatum. These results indicate that AF64A induces an increase in serotonergic neuronal activity and decreased densities of 5-HT uptake sites which may affect the change in the other parameters of serotonergic neuronal activities. Furthermore, these results suggest that the impaired cholinergic neuronal activity induces the alteration in the serotonergic nervous activities.

Surface-enhanced Raman scattering (SERS)-based signal amplification and detection methods using plasmonic nanostructures have been widely investigated for imaging and sensing applications. However, SERS-based molecule detection strategies have not been practically useful because there is no straightforward method to synthesize and characterize highly sensitive SERS-active nanostructures with sufficiently high yield and efficiency, which results in an extremely low cross-section area in Raman sensing. Here, we report a high-yield synthetic method for SERS-active gold-silver core-shell nanodumbbells, where the gap between two nanoparticles and the Raman-dye position and environment can be engineered on the nanoscale. Atomic-force-microscope-correlated nano-Raman measurements of individual dumbbell structures demonstrate that Raman signals can be repeatedly detected from single-DNA-tethered nanodumbbells. These programmed nanostructure fabrication and single-DNA detection strategies open avenues for the high-yield synthesis of optically active smart nanoparticles and structurally reproducible nanostructure-based single-molecule detection and bioassays.

Here, we synthesized highly stable DNA-embedded Au/Ag core-shell nanoparticles (NPs) by a straightforward silver-staining of DNA-modified Au nanoparticles (AuNPs); unlike conventional DNA-surface modified NPs that present particle stability issues, DNA-embedded core-shell NPs offer an extraordinary stability with nanoscale controllability of silver shell thickness; these DNA-embedded core-shell NPs show excellent biorecognition properties and Ag shell-thickness-based optical properties, distinctively different from those of a mixture of AuNPs and AgNPs or Ag/Au alloy nanoparticles.

Dramatic progress has been made over the recent decade in the applications of metallic nanoparticles in the field of biomolecule detection. The useful physical and chemical properties (e.g., availability of various synthetic methods of size- and shape-controlled nanoparticles, size- and shape-dependent optical properties, availability of various surface chemistries and biocompatibility) of metallic nanoparticles have brought development to the ultrasensitive detection of biomolecules at the attomolar level and this sensitivity enables the diagnosis of otherwise undetectable biomarkers of many fatal diseases, including Alzheimer's disease. Furthermore, coupled with the strong physical properties and biocompatible nature of gold nanoparticles in in vivo conditions, the scope of applications for these particles have been broadened into the field of in vivo imaging, such as X-ray contrasting agents, and also cellular tracking. Here, we review synthetic methods and optical properties of metallic nanoparticles and their use in ultrasensitive, in vitro and in vivo biodiagnostic methods.

We investigated the structure and electronic properties of unidirectional Pt(2)Si nanowires (NWs) grown on a Si(100)-2 degrees off surface. We found that Pt(2)Si NWs were formed along the step edges of the Si(100)-2 degrees off surface with c(4x6) reconstructions that occurred on the terraces of Si(100) using scanning tunneling microscopy and the structure of formed NWs was found to be Pt(2)Si by core-level photoemission spectroscopy. Moreover, we confirmed that the electronic band structures of the NWs along the NW direction are different from those perpendicular to the NWs and the surface state induced by the Pt(2)Si NWs was observed with a small density of state using the angle-resolved photoemission spectra.

We have studied the adsorption and decomposition of thiophene (C4H4S) on Ge(100) using scanning tunneling microscopy (STM), high-resolution core-level photoemission spectroscopy (HRPES), and density functional theory (DFT) calculation. Analysis of S 2p core-level spectra reveals three adsorption geometries, which we assign to a Ge-S dative bonding state, a [4 + 2] cycloaddition bonding state, and a decomposed bonding state (desulfurization reaction product). Furthermore, we found that the number ratio of the three adsorption geometries depended on the molecular coverage and the annealing temperature. At low coverages, the kinetically favorable dative bonding state is initially formed at room temperature. As the molecular coverage increases, thermodynamically stable [4 + 2] cycloaddition reaction products are additionally produced. In addition, we found that as the surface temperature increased, the [4 + 2] cycloaddition reaction product either possibly desorbed as molecular thiophene or decomposed to form a metallocycle-like species (C4H4Ge2) and a sulfide (Ge2S). We systematically elucidate the changes in the bonding states of adsorbed thiophene on Ge(100) according to the thiophene coverage and annealing temperature.

The adsorption of thiophene on Ge(100) has been studied using scanning tunneling microscopy (STM), high-resolution core-level photoemission spectroscopy (HRPES), and density functional theory (DFT) calculations. Until now, thiophene is known to react with the Ge(100) dimer through a [4 + 2] cycloaddition reaction at room temperature, similar to the case of thiophene on Si(100). However, we found that thiophene has two adsorption geometries on Ge(100) at room temperature, such as a kinetically favorable Ge-S dative bonding configuration and a thermodynamically stable [4 + 2] cycloaddition adduct. Moreover, our STM results show that under 0.25 ML thiophene molecules preferentially produce one-dimensional molecular chain structures on Ge(100) via the Ge-S dative bonding configuration.

Self-assembled monolayers (SAMs) of octanethiol and benzeneethanethiol were deposited on clean Pt(111) surfaces in ultrahigh vacuum (UHV). Highly resolved images of these SAMs produced by an in situ scanning tunneling microscope (STM) showed that both systems organize into a super-structure mosaic of domains of locally ordered, closely packed molecules. Analysis of the STM images indicated a (square root 3 x square root 3)R30 degrees unit cell for the octanethiol SAMs and a 4(square root 3 x square root 3)R30 degrees periodicity based on 2 x 2 basic molecular packing for the benzeneethanethiol SAMs under the coverage conditions investigated. SAMs on Pt(111) exhibited differences in molecular packing and a lower density of disordered regions than SAMs on Au(111). Electron transport measurements were performed using scanning tunneling spectroscopy. Benzeneethanethiol/Pt(111) junctions exhibited a higher conductance than octanethiol/Pt(111) junctions.

Background: The commercially available formulation of amlodipine is conjugated with besylate salt to increase water solubility. Recently, a new amlodipine salt formulation has been developed in which the free base of amlodipine is conjugated with a chemically different salt, adipate., Objective: The goal of this study was to compare the antihypertensive effect and tolerability of amlodipine adipate with those of amlodipine besylate in patients with mild to moderate hypertension., Methods: This was a multicenter, randomized, doubleblind, parallel-group study in which patients received 8 weeks of treatment with either amlodipine adipate or amlodipine besylate. The primary efficacy variable was noninferiority of the difference in mean changes from baseline in trough diastolic blood pressure (DBP) after 8 weeks of treatment. Secondary efficacy variables included mean changes in DBP, systolic blood pressure (SBP), and response rate (defined as the proportion of patients whose DBP was <90 mm Hg or whose DBP had decreased from baseline by > or =10 mm Hg). The incidence of adverse events (AEs) was also assessed., Results: Two hundred eleven patients were randomly assigned to receive amlodipine adipate (n = 106) or amlodipine besylate (n = 105). Study patients were primarily female (54.5%), with a mean (SD) age of 52.2 (9.6) years and a mean body weight of 67.1 (10.2) kg; there were no between-group differences in demographic profiles. After 4 weeks of randomized treatment, 58 (27.5%) patients (29 [27.4%] amlodipine adipate, 29 [27.6%] amlodipine besylate) had not achieved a mean DBP <90 mm Hg, and their dose was doubled. Mean DBP changes at 8 weeks were -15.2 (7.3) mm Hg in the amlodipine adipate group and -14.2 (7.4) mm Hg in the amlodipine besylate group (P = NS). Because the 95% CI for the difference in mean DBP changes between groups (-0.53 to 2.55) was within the prespecified lower limit (-4 mm Hg), amlodipine adipate was considered noninferior to amlodipine besylate. Mean SBP changes were -24.9 (12.1) mm Hg in the amlodipine adipate group and -22.0 (14.7) mm Hg in the amlodipine besylate group (P = NS). The response rates were 92.0% for amlodipine adipate and 95.4% for amlodipine besylate (P = NS). The overall incidence of clinical AEs was 20.8% in the amlodipine adipate group and 25.7% in the amlodipine besylate group (P = NS). Drug-related clinical AEs occurred in 5.7% and 12.4% of patients in the respective treatment groups (P = NS). Serum uric acid levels decreased significantly from base-line in both groups (P < 0.001)., Conclusions: Eight weeks of treatment with amlodipine adipate produced significant reductions from baseline in blood pressure in these patients with mild to moderate hypertension. The efficacy of amlodipine adipate was not inferior to that of amlodipine besylate. Tolerability was comparable between the 2 treatment groups.

Dehydroevodiamine has been reported to have neuroprotective and antiamnesic effects. This study examined the effects of dehydroevodiamine on glutamate release and uptake in cultured cerebellar cells. Chronic dehydroevodiamine exposure decreased the viability of granule cells. The basal and N-methyl-D-aspartate (NMDA)-induced release of glutamate from granule cells were decreased (26 and 14%) by dehydroevodiamine. The NMDA-induced release of glutamate was concentration-dependently inhibited in the granule cells. The basal and NMDA-induced releases of glutamate in chronically dehydroevodiamine-preexposed granule cells were unaffected by dehydroevodiamine. Glutamate uptake in the glial cells incubated without and with cAMP was inhibited (31% and 8%, respectively) by dehydroevodiamine. In the chronically dehydroevodiamine-preexposed glial cells, glutamate uptake was increased (8%) in the cAMP-coexposed glial cells by dehydroevodiamine but was unaffected in the naive cells. In addition, dehydroevodiamine potentiated (from 20% to 34%) the inhibition of L-pyrollidine-2,4-dicarboxylic acid (PDC) on glutamate uptake in naive glial cells, but this inhibition was reduced (from 41% to 26%) in cAMP-coexposed glial cells. These results suggest that dehydroevodiamine inhibits glutamate uptake and release. Furthermore, the results suggest that the characteristics of glutamate release and uptake in granule and glial cells may be altered by chronic exposure to dehydroevodiamine.

2-Bromobenzaldehydes react with arylhydrazines in toluene at 100 [degree]C in the presence of a catalytic amount of a palladium catalyst and phosphorus chelating ligands such as 1,1[prime or minute]-bis(diphenylphosphino)ferrocene and 1,3-bis(diphenylphosphino)propane along with NaO-t-Bu to afford 1-aryl-1H-indazoles in good yields.

Cultured cerebellar astrocytes were exposed to nicotine with or without dibutyryl cAMP (dBcAMP) for 2 to 10 days in situ in order to determine the effects of nicotine exposure on glutamate uptake in differently conditioned astrocytes. After acute nicotine exposure, glutamate uptake was lower and higher in the naive and the preconditioned astrocytes, respectively. After subacute nicotine exposure, the inhibitory effect of L-trans-pyrollidine-2,4-dicarboxylic acid (PDC) on the glutamate uptake in the naive and the conditioned cells was decreased and increased, and the IC50's for PDC were higher and lower, respectively. In addition, glutamine synthetase activity after subacute nicotine exposure was lower in the naive and higher in the conditioned astrocytes; the change in Na+/K+ ATPase activity was the opposite to that in glutamine synthetase activity. These results suggest that nicotine modulates the characteristics of glial glutamate transporters and glutamine synthetase activity in astrocytes. Furthermore, nicotine might differently affect the state of glial cells during development.

Rats were given nicotine (25 ppm) in their drinking water at the start of their mating period in order to study the expressions of glutamate transporter subtypes in cerebellar astrocytes following the chronic exposure of nicotine after mating. After the offspring were delivered, each group was divided into two subgroups. One group, the control group, was given distilled water only and the other group, the experimental group, was given distilled water containing nicotine. The cerebellar astrocytes were prepared from 7 day-old pups at each group. Ten days after the cells were cultured, the expression of the glutamate transporter subtypes (GLAST and GLT-1) was determined using immunochemistry and immunoblotting. During the continuous treatments, the developmental expression patterns of the GLAST and GLT-1 in the cerebellum were also determined from 2, 4 and 8 week-old rats. The expression levels of GLAST in cultured astrocytes of both the pre- or post-natally exposed groups were higher than those of the control group. However, these expression levels of the continuously exposed group were lower than those of the control group. Compared to those of the control group, the GLT-1 expression levels of all the nicotine-treated groups were higher, particularly in the continuously treated group. According to the results from the immochemistry procedure, the cerebellar GLAST and GLT-1 expression levels of all nicotine-treated groups were lower than those of the control group at each age. However, the immunoblotting procedure showed that the cerebellar GLT-1 expression levels of all the nicotine-treated groups were higher than those of the control group, except for the rats that were continuously exposed for 8 weeks using immunoblotting. These results suggest that the expression of the glial GLAST and GLT-1 are altered differently depending on the initial exposure time and the particular period of nicotine exposure. In addition, nicotine exposure during gestation has persistent effects on glial cells.

Ketamine, a dissociative anaesthetic in use since 1970, produces prominent psychoactive effects in humans. Its non-medical use has raised concerns in many countries, including Singapore. This paper narrates the psychedelic and psychotic effects of ketamine in two ketamine dependent patients who have presented to the psychiatric service. These effects were dose-related and comprised multimodal hallucinatory experiences, a sense of slowing, paranoid ideation and enhancement of sexual, musical and sensory enjoyment. In both ketamine users the psychotic symptoms resolved quickly with symptom-targeted treatment. However, breaking the ongoing addiction cycle seemed more difficult. The neuro-pharmacological mechanisms of these phenomena are largely due to its complex multi-receptors actions, notably through the excitatory amino acids through mainly the N-methy-D-aspartate (NMDA) receptors. The detection of ketamine abuse requires a high index of suspicion and needs to be considered when there is an acute presentation with multi-modal hallucinations and psychosis.

Risperidone is an atypical anti-psychotic medication with both 5HT2 receptor and D2 dopamine receptor antagonism. Its use has been reported to be generally safe with very few gastro-intestinal (GI) adverse or side effects. In this paper, we describe a case of megacolon associated with the use of risperidone. A 44-year-old man suffering from schizophrenia was treated with risperidone and developed gross abdominal distension after twenty-five days. Abdominal X-ray and colonoscopy showed megacolon. He improved following a surgical decompression and a reduction of risperidone dosage. We discuss the neuro-electro-physiological mechanisms of gastro-intestinal motility and conclude that the risperidone-associated megacolon may be dose-related and that there should be a heightened awareness of such possible GI complication when using risperidone.

Cerebellar granule and glial cells were cultured from 7 day-old rat pups after pre- and post-natal nicotine treatment. Ten days later, the basal release of glutamate in the granule cells prepared from the pre- and post-natally nicotine-exposed pups was higher and lower than the controls, respectively. The N-methyl-D-aspartate-induced release of glutamate was higher in the granule cells of post-natal nicotine exposed rats. However, the nicotine-induced glutamate release was either unchanged or was lower in the granule cells of all nicotine-treated pups. The basal glutamate uptake was higher in the glial cells from those exposed pre-natally and lower in the continuously nicotine-exposed pups. The sensitivities of L-trans-pyrrolidine-2,4-dicarboxylic acid on glutamate uptake were higher in all nicotine treated groups. There was a higher number of specific [3H]dizocilpine binding sites in the pre- or continuously nicotine-exposed group. These results suggest that the cerebellar cell properties are altered after perinatal nicotine exposure and that the development of an excitatory amino acid system might be affected differently depending on the nicotine exposure time.

Three types of learning and memory tests (Morris water maze, active and passive avoidance) were performed in rats following intracerebroventricular infusion of ethylcholine aziridium (AF64A). In Morris water maze, AF64A-treated rats showed the delayed latencies to find the platform from 6th day after the infusion. In pretrained rats, AF64A caused the significant delay of latency at 7th day, but not 8th day. In the active avoidance for the pre-trained rats, the escape latency was significantly delayed in AF64A-treatment. The percentages of avoidance in AF64A-treated rats were less increased than those in the control. Especially, the percentage of no response in the AF64A-treated rats was markedly increased in the first half trials. In the passive avoidance, AF64A-treated rats shortened the latency 1.5 h after the electronic shock, but not 24 h. AF64A also caused the pretrained rats to shorten the latency 7th day after the infusion, but not 8th day. These results indicate that AF64A might impair the learning and memory. However, these results indicate that the disturbed memory by AF64A might rapidly recover after the first retrain. Furthermore, these results suggest that AF64A may be a useful agent for the animal model of learning for spatial cognition.

Vascular endothelial growth factor (VEGF) is an angiogenic stimulator which functions through two endothelial specific tyrosine kinase receptors, Flt-1 and Flk-1. In this work, we show that an 11-amino acid peptide derived from the second immunoglobulin-like domain of Flt-1 functions as an angiogenic inhibitor in chick chorioallantoic membrane and inhibited VEGF-induced vascular permeability in Miles' assay without binding to VEGF directly. Circular dichroism and nuclear magnetic resonance analyses indicate that this peptide forms a stable extended structure in solution, presumably beta-sheet structure and is most likely existing as a dimer. Our results suggest that this small peptide functions as an angiogenic inhibitor by inhibiting VEGF function through a non-VEGF binding mechanism.

Cerebellar granule and glial cells prepared from 7 day-old rat pups were used to investigate the effects of sub-acute nicotine exposure on the glutamatergic nervous system. These cells were exposed to nicotine in various concentrations for 2 to 10 days in situ. Nicotine-exposure did not result in any changes in cerebellar granule and glial cell viability at concentrations of up to 500 microM. In cerebellar granule cells, the basal extracellular levels of glutamate, aspartate and glycine were enhanced in the nicotine-exposed granule cells. In addition, the responses of N-methyl-D-aspartate (NMDA)-induced glutamate release were enhanced at low NMDA concentrations in the nicotine-exposed granule cells. However, this decreased at higher NMDA concentrations. The glutaminase activity was increased after nicotine exposure. In cerebellar glial cells, glutamate uptake in the nicotine-exposed glial cells were either increased at low nicotine exposure levels or decreased at higher levels. The inhibition of glutamate uptake by L-trans-pyrollidine-2,4-dicarboxylic acid (PDC) was lower in glial cells exposed to 50 microM nicotine. Glutamine synthetase activity was lower in glial cells exposed to 100 or 500 microM of nicotine. These results indicate that the properties of cerebellar granule and glial cells may alter after subacute nicotine exposure. Furthermore, they suggest that nicotine exposure during development may modulate glutamatergic nervous activity.

The NMDA receptor non-competitive antagonist, [3H]MK-801, was used as a ligand for an autoradiographic study to determine the effects of lead on NMDA receptor in rat brain. Adult male rats were given lead acetate, 100 mg/kg, or sodium acetate, 36 mg/kg (control), by i.p. for 7 days. Lead levels were detected in blood (41.1 micrograms/dl) and brain (16.7-29.4 micrograms/g). Concentrations of lead in various brain regions did not differ. [3H]MK-801 binding was heterogeneous throughout the brain with the following order of binding densities: hippocampal formation > cortex > caudate-putamen > thalamus > brainstem. Lead exposure caused a decrease in [3H]MK-801 binding to NMDA receptors in the hippocampal formation including CA2 stratum radiatum, CA3 stratum radiatum and presubiculum, and in the agranular insular, cingulate, entorhinal, orbital, parietal and perirhinal areas of cerebral cortex. In another experiment, female rats were exposed pre- and post-natally from the 4th +/- 1 post conception day with 1,000 ppm lead in their drinking water. This treatment continued after weaning. No effects of lead on [3H]MK-801 binding were found at postnatal day (PM) 28. However, lead caused a significant increase in [3H]MK-801 binding in the hippocampus including CA1 and CA2, and in the occipital and temporal cortical areas at PN 56 and at PN 112. Increases in [3H]MK-801 binding were also found in entorhinal cortex and dentate gyrus at PN 112. The hippocampal formation is a critical neural structure for learning and memory processes, whereas cortical and subcortical regions are involved in the modulation of complex behavioral processes. NMDA receptors have been shown to play a key role in synaptic plasticity underlying learning and memory. Therefore, lead-induced alterations of ligand binding to NMDA receptors in the hippocampal formation and cortical areas may play a role in lead-induced neurotoxicity.

Changes in the release and uptake of glutamate in cerebellar granule and glial cells of offspring of lead-exposed mothers were determined. In cultured cerebellar granule cells exposed to lead for 5 days, glutamate release was less influenced upon N-methyl-D-aspartate (NMDA) stimulation than that in the control. Although the NMDA-stimulated release of glutamate in cerebellar granule cells prepared from lead-exposed first generation pups was not different from that of the control group, the S-nitroso-N-acetylpenicillamine (SNAP)-stimulated release of glutamate in cerebellar granule cells obtained from lead-treated pups was less elevated than that in the control. Furthermore, in cerebellar granule cells obtained from lead-exposed second generations pups, glutamate release did not respond to both NMDA and SNAP stimulation. In cerebellar glial cells exposed to lead, the basal glutamate uptake was not changed. However, the L-trans-pyrollidine-2,4-dicarboxylic acid (PDC)-blocking effects was significantly reduced. In glial cells obtained from lead-exposed pups, the glutamate uptake was also less blocked by PDC than that in the control. Further decreases in PDC-blocking effects were observed in cerebellar glial cells obtained from lead-treated second generation pups compared to those from the control group. These results indicate that lead exposure induces the changes in the sensitivities of the glutamate release and uptake transporter. In addition, these results suggest that lead exposure might affect the intracellular signalling pathway and transmission in glutamatergic nervous system.

To determine changes in response to N-methyl-D-aspartate (NMDA) and kainic acid (KA) in cerebellar granule cells of offspring of lead-exposed mothers, pregnant rats received 0.25% lead acetate in their drinking water 2 days after mating. The control animals were given sodium acetate (0.125%) in their drinking water. The cerebellar granule cells were cultured from 8-day old pups. Changes in the levels of cytosolic Ca++ and cGMP and the release of glutamic acid were measured using fura-2 spectrofluorometer, radio-immunoassay, and HPLC, respectively. Increases in cytosolic Ca++ in response to 50 microM of NMDA and KA were less responsive (77%) in the lead exposed group as compared to that of the control group. However, the maximum responses to KA were not different. The NMDA- and KA-stimulated release of glutamate from cerebellar granule cells prepared from lead-exposed pups were also significantly reduced. While the NMDA-induced elevation of cGMP was not affected in the lead-exposed pups, the normal KA-induced increases in cGMP level in cerebellar granule cells of lead-exposed pups was not observed. The specific binding of [3H]MK-801 was significantly lower in cerebellar granule cells of the lead-exposed pups. These results indicate that lead exposure to the mother affects excitatory amino acid systems during the development of the offspring.

We used the NMDA receptor non-competitive antagonist, [3H]MK-801, as a ligand for an autoradiographic study to determine the effects of lead on NMDA receptor in the rat brain. Adult male rats were administered lead acetate, 100 mg/kg, or sodium acetate, 36 mg/kg (control), by i.p. for 7 days. High lead levels were detected in blood (41.1 microg/dl) and in brain (16.7-29.4 microg/g). Concentrations of lead in brain regions were not significantly different. The [3H]MK-801 binding was heterogeneously distributed throughout the rat brain with the following order of binding densities: hippocampal formation > cortex > caudate-putamen > thalamus > brainstem. Lead exposure produced a significant decrease in [3H]MK-801 binding to the NMDA receptor in the hippocampal formation including CA2 stratum radiatum, CA3 stratum radiatum, hilus dentate gyrus and presubiculum, and in the cerebral cortex including agranular insular, cingulate, entorhinal, orbital, parietal and perirhinal areas. The hippocampal formation is known as a critical neural structure for learning and memory processes, whereas, cortical and subcortical regions have been demonstrated to be involved in the modulation of complex behavioral processes. The NMDA receptor has been demonstrated to play a key role in synaptic plasticity underlying learning and memory. Lead-induced alterations of NMDA receptors in the hippocampal formation and cortical areas may play a role in lead-induced neurotoxicity.

Changes in glutamatergic nervous activities following intracerebroventricular (icv) administration of ethylcholine aziridinium (AF64A) were studied in rats. The levels of total glutamate, those of glutamate in cerebrospinal fluid (CSF) and in extracellular fluid (ECF) of striatum, the activities of glutamine synthetase (GS), glutaminase and glutamate dehydrogenase (GDH) and the specific binding sites of [(3)H]MK801 in striatum, hippocampus and frontal cortex were assessed a week after the infusion of AF64A (3 nmol) into lateral ventricle. The levels of total glutamate were significantly decreased in striatum, hippocampus and frontal cortex after AF64A treatment. Although the levels of glutamate in CSF weren't changed after AF64A treatment, the levels of glutamate in ECF of striatum were significantly decreased (62.6%). GS activities in striatum were significantly decreased. But, glutaminase activities in striatum were significantly increased. However, the activities of GS and glutaminase in frontal cortex and hippocampus weren't changed. Although GDH activities in frontal cortex were significantly decreased, those in striatum and hippocampus weren't altered. The striatal densities of [(3)H]MK 801 binding sites were increased without changes in its affinity. Also, the specific binding sites of [(3)H]MK801 were increased in frontal cortex but not in hippocampus. These results indicate that the glutamatergic nervous activities were altered with the infusion of AF64A into lateral ventricle. Furthermore, it suggest that the decreased levels of glutamate after AF64A treatment may affect the change in the other parameters of glutamatergic neuronal activities.

The authors present the first human case of Clinostomum pharyngitis in Taegu, Korea. The patient was a 56-year old male who visited an otolaryngology clinic due to foreign body sensation and pain of the pharyngeal region for 3-4 days. He used to eat raw fresh-water fish. Otolaryngological examinations revealed a living worm adhered to the right posterior pharyngeal wall. The worm removed was identified as C. complanatum after morphological observations. It is likely that more attention should be paid to eating raw fresh-water fish in Korea with regards to Clinostomum pharyngitis.

A new technique of image acquisition for quantitative receptor autoradiography and in situ hybridization histochemistry was developed using storage phosphor screen imaging. This method was at least 4-5 times faster than conventional film densitometry. Two of the advantages of the phosphor screen method are high sensitivity and wide linear range of response. Other aspects of this method were compared with those of conventional densitometry. Use of storage phosphor screen imaging will allow greatly increased speed of pharmacological screening procedures that utilize quantitative autoradiography.

The behavioral response, dopamine metabolism, and characteristics of dopamine subtypes after developing the hyperglycemia were studied in the striata of rats. In animals developed hyperglycemia, the on-set and duration of cataleptic behavior responded to SCH 23390 injection was delayed and shortened, respectively. However, the cataleptic responses to spiperone occurred significantly earlier in on-set and prolonged in duration. Dopamine metabolites, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), were significantly reduced in the striata of hyperglycemic rats. However, level of DA was significantly increased. It is noted that the ratios of DOPAC and HVA to DA were decreased, suggesting decreased turnover of DA. The affinity of striatal D-1 receptors was significantly increased without changes in the number of binding sites, while the maximum binding number of D-2 receptors was significantly increased without affecting its affinity in the diabetic rats. These results indicate that the dopaminergic activity in the striata was altered in hyperglycemic rats. Furthermore, it suggests that the upregulation of dopamine receptors might be due to the decreased dopamine metabolism.

Effects of bicuculline in vitro, and acute and chronic treatment of a subconvulsive dose of bicuculline on [3H]SR 95531 binding to discrete regions of rat brains were studied in Sprague-Dawley rats. Scatchard analysis of the binding isotherms exhibited two populations of binding sites for [3H]SR 95531 in frontal cortex, cerebellum, striatum and substantia nigra. The apparent KD for high-affinity sites was significantly increased in the frontal cortex and cerebellum in the presence of bicuculline (1 microM) with no change in Bmax. In contrast, the apparent affinity for low-affinity sites was not altered in the presence of bicuculline in these regions, whereas the Bmax was significantly decreased in the cerebellum. Following acute (2 mg/kg, i.p.) or chronic (2 mg/kg, i.p. for 10 days) bicuculline treatment, [3H]SR 95531 binding was also investigated in various regions of brains. The acute bicuculline treatment did not affect the [3H]SR 95531 binding in any of the regions studied. In contrast, apparent affinity for [3H]SR 95531 was significantly decreased in low-affinity sites of all regions studied in rats treated chronically with bicuculline. The Bmax values of high and low-affinity sites were significantly increased in the cerebellum with no change in the frontal cortex, striatum and substantia nigra. The present study demonstrates that chronic bicuculline treatment decreases apparent affinity of [3H]SR 95531 binding whereas the treatment increases apparent affinity of [3H]muscimol binding (1) in various brain regions. The results indicate that significant increase in Bmax of [3H]SR 95531 and [3H]muscimol binding in the cerebellum may be due to true up-regulation of GABA binding sites, involving increased de novo synthesis of receptor protein.(ABSTRACT TRUNCATED AT 250 WORDS)

The protective effects of simultaneous and continuous administration of physostigmine and trihexyphenidyl against soman-induced toxicity were studied in guinea pigs. Not only did trihexyphenidyl reduce physostigmine-induced toxicity when it was administered continuously to the animals along with physostigmine, the combination afforded greater protection from soman lethality than did either agent administered alone. The combination pretreatment also gave better protection against soman-induced body weight loss and decreased water consumption and attenuated the down-regulation of cholinergic receptors which occurred when physostigmine alone was used. The onsets of other soman-induced toxicity signs were delayed significantly by the combination pretreatment regimen. These results suggest that simultaneous administration of the combination of physostigmine and trihexyphenidyl may be more useful than physostigmine alone as prophylaxis against soman poisoning.

The characteristics of dopamine uptake after acute and subacute cocaine administration were determined in striata from WKY and SHR. In acutely-treated (40 mg/kg, s.c.) rats, significant increases in the Vmax of dopamine uptake were observed 30 min after the cocaine injection in both strains, without changes in Km values. The in vitro IC50 for cocaine was significantly decreased at 30 min in WKY and at 2 h in SHR. However, the in vitro IC50 for GBR-12909 was significantly increased at 30 min and at 2 h in both strains following cocaine administration. In both strains, the density (Bmax) of the [3H]GBR-12935 binding site was significantly increased at 30 min and at 2 h with no changes in Kd. In subacutely-treated (20 mg/kg, twice daily for 3 or 7 days) rats, a significant increase in the Km for dopamine uptake was observed in 7 day treated SHR. The in vitro IC50 for GBR-12909 was significantly increased in 3 day treated WKY. The results suggest that cocaine administration alters dopamine uptake and characteristics of dopamine uptake sites in the rat brain.

The characteristics of D-1 and D-2 dopamine receptors after acute and subacute cocaine administration were determined in striata and nuclei accumbens from WKY and SHR. In striata from acutely treated rats, significant increases in D-2 receptor density were observed at 30 min, 2 or 24 h following cocaine injection in both strains without changes in affinities. The density of D-1 receptors was significantly decreased 30 min after the injection in WKY, but not in SHR. In striata from subacutely treated rats, the density of D-1 receptors was significantly increased in 3- and 7-day treated WKY, but not in SHR. The affinities of both binding sites remained unchanged. In nuclei accumbens, the change in both D-1 and D-2 receptors after cocaine administration were similar to those observed in the striatum. The results suggest that cocaine administration alters dopamine receptor binding characteristics. Furthermore, D-1 and D-2 dopamine receptors appear to be differently regulated.

Effects of acute and subacute cocaine administration on dopamine (DA) and its metabolites in striata and nucleus accumbens of nine week-old Wistar-Kyoto and spontaneously hypertensive rats were studied. Levels of DA,3,4-dihydroxphenylacetic acid (DOPAC) and homovanillic acid (HVA) were determined by HPLC-EC. There were no differences in DA levels in striata and nucleus accumbens between control WKY and SHR. Levels of DA in two brain regions were unaffected in groups treated acutely with cocaine. Both strains showed a significant increase in striatal HVA 2 hr after cocaine injection. Seven day treatment declined DA levels in striatum of WKY and in nucleus accumbens of SHR. However, only WKY treated subacutely with cocaine showed significantly increased HVA either with or without changes in DOPAC in nucleus accumbens and striatum, respectively. Increased DOPAC/DA and HVA/DA ratios appeared only in striatum of WKY and in nucleus accumbens of SHR following subacute treatment. These results suggest that subacute cocaine administration affects DA levels in striata and nucleus accumbens differently between WKY and SHR.

Rats were treated with diisopropylfluorophosphate (DFP) acutely or daily for 14 days. The involvement of various presynaptic and postsynaptic functions of the cholinergic system in the development of tolerance to DFP was studied. Receptor density and affinity of both muscarinic and nicotinic receptors, high-affinity choline uptake, and [K+]-evoked release of acetylcholine (ACh) by atropine were not changed after acute administration of 2 mg/kg DFP. Both muscarinic and nicotinic receptors were down-regulated to the same extent (40-50%) after subacute administration of DFP (1 mg/kg) without changes in their affinities. Binding sites of muscarinic receptors were maximally decreased after 7 days of DFP administration. Thereafter, they remained constant throughout 14 days of administration. One hour after the last injection of 2 mg/kg DFP to subacutely treated rats, the maximum velocity of high-affinity choline uptake was significantly decreased in the striatum (33%) and hippocampus (53%) without changes in Km values. Twenty-four hours after the last injection of DFP, only a higher dose of DFP (2 mg/kg) significantly inhibited choline uptake. Potassium-evoked release of ACh by slices of striatum was not different between acutely and subacutely treated rats. However, the release of ACh by slices of striatum and hippocampus was significantly increased by atropine in subacutely treated rats. It is suggested that along with the down-regulation of the postsynaptic receptors, subsensitivity of presynaptic functions of the cholinergic synapse also develops during subacute administration of DFP.