Category-based errors and the accessibility of unbiased spatial memories: A retrieval model.

Studies have consistently shown a spatial memory bias such that a target location is remembered toward the prototypical location of the region to which the target belongs, indicating a blending between the target’s specific information and the generic information of its region. The authors investigated whether people retain a veridical representation of a target location after a delay by determining the locus of the blending (during encoding, delay, or retrieval). To examine accessibility to the original target location, they used a recognition task, which is less demanding than the traditional reproduction procedure. The results showed that participants were able to recognize the original position of a target over their own biased recalled position after both a short (1,500 ms) and a longer (5,000 ms) delay. These findings reveal that spatial memories can be undistorted despite distorted recall responses. Results are discussed in terms of J. Huttenlocher, L. V. Hedges, and S. Duncan’s (1991) category adjustment model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Update on Glycosphingolipids Abundance in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most frequent type of primary liver cancer. Low numbers of HCC patients being suitable for liver resection or transplantation and multidrug resistance development during pharmacotherapy leads to high death rates for HCC patients. Understanding the molecular mechanisms of HCC etiology may contribute to the development of novel therapeutic strategies for prevention and treatment of HCC. UDP-glucose ceramide glycosyltransferase (UGCG), a key enzyme in glycosphingolipid metabolism, generates glucosylceramide (GlcCer), which is the precursor for all glycosphingolipids (GSLs). Since UGCG gene expression is altered in 0.8% of HCC tumors, GSLs may play a role in cellular processes in liver cancer cells. Here, we discuss the current literature about GSLs and their abundance in normal liver cells, Gaucher disease and HCC. Furthermore, we review the involvement of UGCG/GlcCer in multidrug resistance development, globosides as a potential prognostic marker for HCC, gangliosides as a potential liver cancer stem cell marker, and the role of sulfatides in tumor metastasis. Only a limited number of molecular mechanisms executed by GSLs in HCC are known, which we summarize here briefly. Overall, the role GSLs play in HCC progression and their ability to serve as biomarkers or prognostic indicators for HCC, requires further investigation.     

Study of the Adsorption Space of Modified Clinoptilolites

Carbon dioxide （CO2） adsorption is an important adsorbent characterization method and a significant industrial process. In separation and recovery technology, the adsorption of the CO2 is important to reduce the concentration of this gas considered as one of the greenhouse gases. Natural zeolites, particularly clinoptilolite, are widely applied as adsorbents. In this regard, in the present research, the structure, composition and morphology of modified with hexafluorosilicate （HFSi） and orthophosphoric acid （H3PO4） clinoptilolites were investigated by characterizations and measurements made with, X-ray diffraction （XRD）, thermogravimetric analysis （TGA）, scanning electron microscopy-energy dispersive X-ray analysis （SEM-EDAX） and gravimetric adsorption. Additionally, the surface Chemistry of the modified clinoptilolites was analyzed by applying diffuse reflectance fourier transform infrared spectrometry （DRIFTS）. Further, the interaction of CO2 within the adsorption space of these modified clinoptilolites and a synthetic ZSM-5 zeolite was studied with the help of adsorption measurements. After all, an appropriate theoretical methodology for the analysis of the XRD and adsorption data was applied. The calculated cell parameters of the tested are similar to those reported for a typical clinoptilolite of： a = 17.662 A, b = 17.911A, c = 7.407 ~ and fl = 116.40 The resolution of the TGA derivative profiles indicated the presence of two steps for water release, one of them represents the loss of majority of the water present in the micropores. This was evidenced as a broad peak centered at about 50℃ for the CSW-HFSi-0.1, but at 100 ℃ for the samples CSW-HFSi-0.4. The SEM micrographs corresponding to the modified clinoptilolites, was evidenced that the CSW zeolite shows secondary particles exhibiting diameters from 3 to 40 μm, formed by primary clinoptilolite crystallites showing a crystallite size, φ = 40 nm. The EDAX elemental analysis it can be demonstrated that the exchange process replaced about 85% of the charge compensating ions. The DRIFT spectra of the modified clinoptilolites, specifically, CSW-HFSi-0.1, show a narrow band at about： 3,740 cm-1 corresponding to terminal silanol groups （Si-OH） and a band 3,600-3,650 cm1 resulting from extra-framework AI-OH. With the precision of the measured micropore volumes related to the excellent fitting of the adsorption data by the D-R isotherm equation, it can be affirm that carbon adsorption took only place in the micropore region. The isosteric heat of adsorption calculated for the modified clinoptilolites was greater than those values reported of ZSM-5 zeolite, particle packing silica, dealuminated Y zeolite （DAY） Cd, Zn and Ni-nitroprussides and Cu-nitroprusside and a Ni-MOF. With the obtained result it can be concluded that the modified clinoptilolites with HFSi showed a quality as adsorbent comparable to commercial synthetic zeolites.     

Synthesis and Study of Multifunctional Cyclodextrin–Deferasirox Hybrids

Metal dyshomeostasis is central to a number of disorders that result from, inter alia, oxidative stress, protein misfolding, and cholesterol dyshomeostasis. In this respect, metal deficiencies are usually readily corrected by treatment with supplements, whereas metal overload can be overcome by the use of metal-selective chelation therapy. Deferasirox, 4-[(3Z,5E)-3,5-bis(6-oxo-1-cyclohexa-2,4-dienylidene)-1,2,4-triazolidin-1-yl]benzoic acid, Exjade, or ICL670, is used clinically to treat hemosiderosis (iron overload), which often results from multiple blood transfusions. Cyclodextrins are cyclic glucose units that are extensively used in the pharmaceutical industry as formulating agents as well as for encapsulating hydrophobic molecules such as in the treatment of Niemann–Pick type C or for hypervitaminosis. We conjugated deferasirox, via an amide coupling reaction, to both 6^A-amino-6^A-deoxy-β-cyclodextrin and 3^A-amino-3^A-deoxy-2^A(S),3^A(S)-β-cyclodextrin, at the upper and lower rim, respectively, creating hybrid molecules with dual properties, capable of both metal chelation and cholesterol encapsulation. Our findings emphasize the importance of the conjugation of β-cyclodextrin with deferasirox to significantly improve the biological properties and to decrease the cytotoxicity of this drug.     

Synthesis of New Water Soluble β-Cyclodextrin@Curcumin Conjugates and In Vitro Safety Evaluation in Primary Cultures of Rat Cortical Neurons

Self-aggregation of Curcumin (Cur) in aqueous biological environment decreases its bioavailability and in vivo therapeutic efficacy, which hampers its clinical use as candidate for reducing risk of neurodegenerative diseases. Here, we focused on the design of new Cur- β-Cyclodextrin nanoconjugates to improve the solubility and reduce cell toxicity of Cur. In this study, we described the synthesis, structural characterization, photophysical properties and neuron cell toxicity of two new water soluble β-CD/Cur nanoconjugates as new strategy for reducing risks of neurodegenerative diseases. Cur was coupled to one or two β-CD molecules via triazole rings using CuAAC click chemistry strategy to yield β-CD@Cur and (β-CD)₂@Cur nanoconjugates, respectively. The synthesized nanoconjugates were found to be able to self-assemble in aqueous condition and form nano-aggregates of an average diameter size of around 35 and 120 nm for β-CD@Cur and (β-CD)₂@Cur, respectively. The photophysical properties, water solubility and cell toxicity on rat embryonic cortical neurons of the designed nanoconjugates were investigated and compared to that of Cur alone. The findings revealed that both new nanoconjugates displayed better water solubility and in vitro biocompatibility than Cur alone, thus making it possible to envisage their use as future nano-systems for the prevention or risk reduction of neurodegenerative diseases.     

Diagnostic agreement between the SCID-II screening questionnaire and the Personality Disorder Examination

Instruments to assess personality disorders offer reliability, but at the cost of large amounts of a skilled clinician's time to make assessments. The Structured Clinical Interview for DSM-III Axis II (SCID-II; Spitzer, Williams, Gibbon, & First, 1990), incorporates a self-report screening questionnaire, reducing the number of items needing evaluation by the interviewer. However, false negative responses may cause clinically important areas to be overlooked. To establish the rate of false negative responses, we compared participant self-report on the SCID-II with Axis II diagnostic assessment done by clinicians using the Personality Disorder Examination (Loranger, Susman, Oldham, & Russakoff, 1987). The false negative rate was low for every diagnosis, supporting validity of following up with clinician questioning only those diagnostic elements endorsed in the self-report. Avoidant and dependent personality disorders were accurately self-reported. This, an efficient assessment instrument for personality disorders might combine self-report of those disorders where self-report is reliable, with clinician assessment where needed.     

Memories out of order: Thought suppression and the disturbance of sequence memory.

Participants in 2 experiments watched a filmed story and then left the lab—with instructions not to think about the film, with instructions to think about the film, or with no instructions. Memories of the film, assessed on participants' return to the lab some 5 hrs later, showed reliable effects of thought suppression on memory for the sequence of events in the film. Participants who suppressed thoughts of the film were less able to retrieve the order of events by several measures than were those in the other groups, even though their retrieval of the events themselves as assessed by recognition, free recall, and cued recall was not generally impaired. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Diagnostic Interview for Borderlines: Psychometric properties and validity.

The Diagnostic Interview for Borderlines (DIB) developed by J. G. Gunderson and J. E. Kolb (1976) performed well in distinguishing 59 patients with Diagnostic and Statistical Manual of Mental Disorders (DSM-III) diagnoses of borderline personality disorder from 31 psychotic inpatients and 50 personality-disordered outpatients (ages 16–55 yrs). However, there was no evidence to support the psychometric rationale for combining the 29 statements used to assess the borderline construct into the 5 area scores (social adaptation, impulse, affects, psychosis, and interpersonal relations) presently utilized in making a DIB borderline diagnosis. Findings do not replicate a previous discriminant function model (Gunderson and Kolb; see record 1979-23763-001) and suggest that further improvements in the construct validity of the DIB will require a clearer delineation of the features of the construct as well as additional studies of the psychometric properties of the present instrument. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental antecedents of taxonomic and thematic strategies at 3 years of age.

Individual differences in children's conceptual strategies at 3 years were predicted by several aspects of children's behavior and language at 13 and 24 months of age. Production of pointing gestures at 13 months and production of nouns and attributive adjectives at 24 months were positively associated with the use of a taxonomic matching strategy at 3 years of age. Alternatively, an early interest in functional-relational play behavior at 13 months and the production of relational terms at 24 months were positively associated with the tendency to use a thematic conceptual strategy at 3 years of age. Individual perceptual-cognitive processing styles are tentatively proposed as a persisting epigenetic mechanism underlying these individual differences across early sensorimotor, language, and conceptual development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)