Active Targeting Using HER‐2‐Affibody‐Conjugated Nanoparticles Enabled Sensitive and Specific Imaging of Orthotopic HER‐2 Positive Ovarian Tumors

Despite advances in cancer diagnosis and treatment, ovarian cancer remains one of the most fatal cancer types. The development of targeted nanoparticle imaging probes and therapeutics offers promising approaches for early detection and effective treatment of ovarian cancer. In this study, HER‐2 targeted magnetic iron oxide nanoparticles (IONPs) are developed by conjugating a high affinity and small size HER‐2 affibody that is labeled with a unique near infrared dye (NIR‐830) to the nanoparticles. Using a clinically relevant orthotopic human ovarian tumor xenograft model, it is shown that HER‐2 targeted IONPs are selectively delivered into both primary and disseminated ovarian tumors, enabling non‐invasive optical and MR imaging of the tumors as small as 1 mm in the peritoneal cavity. It is determined that HER‐2 targeted delivery of the IONPs is essential for specific and sensitive imaging of the HER‐2 positive tumor since we are unable to detect the imaging signal in the tumors following systemic delivery of non‐targeted IONPs into the mice bearing HER‐2 positive SKOV3 tumors. Furthermore, imaging signals and the IONPs are not detected in HER‐2 low expressing OVCAR3 tumors after systemic delivery of HER‐2 targeted‐IONPs. Since HER‐2 is expressed in a high percentage of ovarian cancers, the HER‐2 targeted dual imaging modality IONPs have potential for the development of novel targeted imaging and therapeutic nanoparticles for ovarian cancer detection, targeted drug delivery, and image‐guided therapy and surgery.     

Following the biocatalytic activities of glucose oxidase by electrochemically cross-linked enzyme-Pt nanoparticles composite electrodes

An integrated platinum nanoparticles (NPs)/glucose oxidase (GOx) composite film associated with a Au electrode is used to follow the biocatalytic activities of the enzyme. The film is assembled on a Au electrode by the electropolymerization of thioaniline-functionalized Pt NPs and thioaniline-modified GOx. The resulting enzyme/Pt NPs-functionalized electrode stimulates the O 2 oxidation of glucose to gluconic acid and H 2O 2. The modified electrode is then implemented to follow the activity of the enzyme by the electrochemical monitoring of the generated H 2O 2. The effect of the composition of the Pt NPs/GOx cross-linked nanostructures and the optimal conditions for the preparation of the electrodes are discussed.     

Dielectric and impedance study of lead-free ceramic: (Na<Subscript>0.5</Subscript>Bi<Subscript>0.5</Subscript>)ZrO<Subscript>3</Subscript>

Polycrystalline sample of (Na_0.5Bi_0.5)ZrO₃ was prepared using a high-temperature solid-state reaction technique. XRD analysis indicated the formation of a single-phase orthorhombic structure. Dielectric study revealed the diffuse phase transition at 425 °C. AC impedance plots were used as tools to analyse the electrical behaviour of the sample as a function of frequency at different temperatures. The ac impedance studies revealed the presence of grain boundary effect at and above 350 °C. Complex impedance analysis indicated non-Debye type dielectric relaxation and negative temperature coefficient of resistance (NTCR) character of (Na_0.5Bi_0.5)ZrO₃. AC conductivity data were used to evaluate the density of states at Fermi level and activation energy of the compound. DC electrical and thermal conductivities of grain and grain boundary have been assessed.     

Impairment in shifting attention in autistic and cerebellar patients.

Magnetic resonance imaging (MRI) and autopsy evidence of early maldevelopment of cerebellar vermis and hemispheres in autism raises the question of how cerebellar maldevelopment contributes to the cognitive and social deficits characteristic of autism. Compared with 18 normal controls, 8 autistic patients (mean age 13.9 yrs) and 6 patients (mean age 8.6 yrs) with acquired cerebellar lesions were similarly impaired in a task requiring rapid and accurate shifts of attention between auditory and visual stimuli. Neurophysiologic and behavioral evidence rules out motor dysfunction as the cause of this deficit. These findings are consistent with the proposal that in autism cerebellar maldevelopment may contribute to an inability to execute rapid attention shifts, which in turn undermines social and cognitive development. Findings support the proposal that the human cerebellum is involved in the coordination of rapid attention shifts in a fashion analogous to its role in the coordination of movement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Vacuum evaporation of KCl-NaCl salts: Part II. vaporization-rate model and experimental results

A model based on the Hertz-Langmuir relation is used to describe how evaporation rates of the binary KCl-NaCl system change with time. The effective evaporation coefficient (α), which is a ratio of the actual evaporation rate to the theoretical maximum, was obtained for the KCl-NaCl system using this model. In the temperature range of 640 °C to 760 °C, the effective evaporation coefficient ranges from ～0.4 to 0.1 for evaporation experiments conducted at 0.13 Pa. At temperatures below the melting point, the lower evaporation coefficients are suggested to result from the more complex path that a molecule needs to follow before escaping to the gas phase. At the higher liquid temperatures, the decreasing evaporation coefficients result from a combination of the increasing vaporflow resistances and the heat-transfer effects at the evaporation surface and the condensate layer. The microanalysis of the condensate verified that composition of the condensate changes with time, consistent with the model calculation. The microstructural examination revealed that the vaporate may have condensed as a single solution phase, which upon cooling forms fine lamellar structures of the equilibrium KCl and NaCl phases. In conclusion, the optimum design of the evaporation process and equipment must take the mass and heat transfer factors and equipment materials issues into consideration.     

Dissociative states in eating disorders: An empirical Rorschach study.

The study explores the DSM-IV-TR classification of eating disorders that is constituted of four subtypes, two of them defined as anorexia (restricting and binge eating/purging) and two as bulimia (purging and non-purging). This classification is based on body weight as the distinguishing criterion. However, psychoanalytic thinking substantially distinguishes between restricting anorexia and the other three subtypes, all of them involving binge eating. Accordingly, binge eating patients are assumed to present different personality characteristics and different dynamics including dissociation proneness as a core component of the disturbance. The dissociative component of binge eating is examined by using the Rorschach Reality-Fantasy Scale (RFS; Tibon, Handelzalts, & Weinberger, 2005) and other Rorschach measures in a sample of 61 female adolescent inpatients diagnosed with eating disorders. This sample was divided into two groups by using the criterion of whether or not the symptoms involve binge eating behavior. The results support the view that dissociation between reality and fantasy is an important facet of binge eating disorders. A case study that demonstrates the utility of the RFS is presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The development of bilingual children's early spelling in English.

By using an extended version of R. Treiman, M. Cassar, and A. Zukowski's (1994) flaps spelling task (wa_er, is it t or d in water?), the authors investigated the metalinguistic awareness of 6-year-old bilingual children from 3 different language backgrounds (LBs): English-LB (English-L1, Mandarin-L2), Chinese-LB (Mandarin-L1, English L2), and Malay-LB (Bahasa Malaysia-L1, English-L2). Treiman et al. found that unilingual English-speaking children's performance was poorer on flapped words than on control words and better on /d/ flaps than on /t/ flaps, suggesting phonology is salient even for beginners. The data for bilinguals revealed predictable group differences in the use of orthographic and phonological awareness for early spellings, even though the children were all attending the same English-medium kindergarten. Possible educational implications for linguistic minority children are briefly discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessment of a mechanism for reactive inhibition of carboxypeptidase A with QM/MM methods

The mechanism for inhibition of carboxypeptidase A (CPA) by the two enantiomers of a reactive inhibitor, N-(2-chloroethyl)-N-methylphenylalanine, has been investigated using computational methods. Quantum mechanical and molecular mechanical (QM/MM) methods have been employed to find likely enzyme binding conformations by comparison with the observed rates of inactivation of the enzyme. The study has shown that the enzyme active site appears to be flexible enough to allow the nucleophilic deactivation reactions of both the (R) and (S) forms of a model of the inhibitor to be catalysed by the Zn(II) cofactor of CPA.