Hippocampectomy disrupts auditory trace fear conditioning and contextual fear conditioning in the rat

The hippocampus is believed to be an important structure for learning tasks that require temporal processing of information. The trace classical conditioning paradigm requires temporal processing because the conditioned stimulus (CS) and the unconditioned stimulus (US) are temporally separated by an empty trace interval. The present study sought to determine whether the hippocampus was necessary for rats to perform a classical trace fear conditioning task in which each of 10 trials consisted of an auditory tone CS (15-s duration) followed by an empty 30-s trace interval and then a fear-producing floor-shock US (0.5-s duration). Several weeks prior to training, animals were anesthetized and given aspiration lesions of the neocortex (NEO; n = 6), hippocampus and overlying neocortex (HIPP; n = 7), or no lesions at all (control; n = 6). Approximately 24 h after trace conditioning, NEO and control animals showed a significant decrease in movement to a CS-alone presentation that was indicative of a conditioned fear response. Animals in the HIPP group did not show conditioned fear responses to the CS alone, nor did a pseudoconditioning group (n = 7) that was trained with unpaired CSs and USs. Furthermore, all groups except the HIPP group showed conditioned fear responses to the original context in which they received shock USs. One week later, HIPP, NEO, and control animals received delay fear-conditioning trials with no trace interval separating the CS and US. Six of seven HIPP animals could perform the delay version, but none could perform the trace version. This result suggests that the trace fear task is a reliable and useful model for examining the neural mechanisms of hippocampally dependent learning. Hippocampus 1998;8:638–646. © 1998 Wiley-Liss, Inc.     

Pan-Asian Consensus on Calcium Hydroxyapatite for Skin Biostimulation,Contouring, and Combination Treatments

BackgroundSeveral usage guidelines for calcium hydroxylapatite (CaHA), a dermal filler material, exist for non-Asian patients, making it necessary to determine whether their findings and consensuses are applicable to Asian patients who have distinct anatomies, cultural preferences, and aesthetic requests.ObjectiveWe sought to develop a Pan-Asian consensus on CaHA use in skin biostimulation, contouring, and combination treatments for face and body indications.MethodsA survey on CaHA usage for contouring and biostimulation indications in Asian patients was conducted, followed by discussions to establish consensus statements and topics for examination.ResultsSeveral aspects of facial shaping and contouring or skin biostimulation with CaHA were agreed on, including that dilution is not a key consideration, that microfocused ultrasound with visualisation precedes CaHA in same day or session treatments, and that cannulas should be used. Among the many agreements on interventions in specific facial and body areas, there were also disagreements due to the diverse Asian patient presentations, requests, and access to tools or products; for example, CaHA should be placed in the interfascial layer for temple contouring, CaHA should not be injected directly into the infraorbital area for safety, and diluted CaHA should be injected subdermally for nonfacial or whole-face biostimulation and contouring.ConclusionOur disagreements highlight the diversity of Asian facial morphotypes and desired aesthetic outcomes and underscore the need for customized aesthetic strategies to accommodate the heterogeneity of Asian anatomies, cultural preferences, and aesthetic ideals. Establishing consensus statements on critical aspects of Asian patient considerations, efficacy and safety, is crucial. This document provides strategic guidance on the use of classic, diluted CaHA for biostimulation or undiluted Radiesse^®(+) (Merz Pharma GmbH & Co. KGaA, Frankfurt, Germany) for lifting and contouring to ensure consistent CaHA delivery for successful patient outcomes.     

Electrochemically dealloyed nanoporous Fe40Ni20Co20P15C5 metallic glass for efficient and stable electrocatalytic hydrogen and oxygen generation

The anion exchange membrane (AEM) in fuel cells requires new, stable, and improved electrocatalysts for large scale commercial production of hydrogen fuel for efficient energy conversion. Fe₄₀Ni₂₀Co₂₀P₁₅C₅, a novel metallic glass ribbon, was prepared by arc melting and melt spinning method. The metallic glass was evaluated as an efficient electrocatalyst in water-splitting reactions, namely hydrogen evolution reaction under acidic and alkaline conditions. In addition, oxygen evolution reaction in alkaline medium was also evaluated. In 0.5 M H₂SO₄, the metallic glass ribbons, after electrochemical dealloying, needed an overpotential of 128 mV for hydrogen evolution reaction, while in 1 M KOH they needed an overpotential of 236 mV for hydrogen evolution. For the oxygen evolution reaction, the overpotential was 278 mV. The electrochemical dealloying procedure significantly reduced the overpotential, and the overpotential remained constant over 20 hours of test conditions under acidic and alkaline conditions. The improved electrocatalytic activity was explained based on the metastable nature of metallic glass and the synergistic effect of metal hydroxo species and phosphates. Based on the excellent properties and free-standing nature of these metallic glass ribbons in electrolyte medium, we propose the current metallic glass for commercial, industrial electrocatalytic applications.

The anion exchange membrane (AEM) in fuel cells requires new, stable, and improved electrocatalysts for large scale commercial production of hydrogen fuel for efficient energy conversion.     

Enhanced electrical and thermal properties of semi-conductive PANI-CNCs with surface modified CNCs

Cellulose nanocrystals (CNCs) are the most commonly used natural polymers for biomaterial synthesis. However, their low dispersibility, conductivity, and poor compatibility with the hydrophobic matrix hinder their potential applications. Therefore, we grafted sulfate half-ester and carboxylic functional groups onto CNC surfaces (S-CNC and C-CNC) to overcome these shortcomings. The effect of the dopants, surfactant ratios, and properties of CNCs on the thermal stability, conductivity, and surface morphology of polyaniline (PANI)-doped CNC nanocomposites were investigated through emulsion and in situ polymerization. The higher electrical conductivity and well-dispersed morphology of SCNC–PANI₃₀ (1.1 × 10⁻² S cm⁻¹) but lower thermal stability than that of CCNC–PANI₃₀ (T₀: 189 °C) nanocomposites are highly related to dispersibility of S-CNCs. However, after 4-dodecylbenzenesulfonic acid (DBSA) was added, the conductivity and thermal stability of SCNC/PANI increased up to 2.5 × 10⁻¹ S cm⁻¹ and 192 °C with almost no particle aggregation because of the increase in charge dispersion. The proposed biodegradable, renewable, and surface-modified S-CNC and C-CNC can be used in high-thermal-stability applications such as food packaging, optical films, reinforcement fillers, flexible semiconductors, and electromagnetic materials.

Biodegradable surface-modified CNCs were synthesized found high dispersibility and flexibility. Polyaniline-doped CNCs nanocomposites were exhibited high conductivity and thermal stability that may be promising for flexible semiconductors.     

Managerial stress,job satisfaction and health in Taiwan

This study tested an integrative work stress model using data from a heterogeneous sample of Taiwanese managers. Results indicated that these managers were under considerable work stress and were at risk of mental and physical ill‐health. Internal control was related to higher job satisfaction and was beneficial to mental health; however, its interaction with work stress was detrimental to psychological well‐being. A specific facet of Type A behaviour pattern was also related to poorer physical health. These results were discussed with an emic emphasis, taking account of some distinctive characteristics of the Chinese culture. Copyright © 1999 John Wiley & Sons, Ltd.     

Cyclooxygenase-2, player or spectator in cyclooxygenase-2 inhibitor-induced apoptosis in prostate cancer cells

BACKGROUND: The antitumor activity of cyclooxygenase-2 (COX-2) inhibitors is thought to involve COX-2 enzyme inhibition and apoptosis induction, but it is unclear whether COX-2 inhibition is required for apoptosis. Different COX-2 inhibitors have similar IC(50) values (concentration for 50% inhibition) for COX-2 inhibition but differ considerably in their abilities to induce apoptosis, suggesting the involvement of a COX-2-independent pathway in apoptosis. To test this hypothesis, we investigated the effect of COX-2 depletion on apoptosis and performed a structure-activity analysis of the COX-2 inhibitor celecoxib in the androgen-independent prostate cancer cell line PC-3. METHODS: Tetracycline-inducible (Tet-On) COX-2 antisense clones were isolated to assess the effect of COX-2 expression on cell viability and sensitivity to apoptosis induced by COX-2 inhibitors. Untreated Tet-On clones differentially expressed COX-2, and doxycycline-treated clones were depleted of COX-2. We synthesized and characterized various celecoxib derivatives with various COX-2 inhibitory activities and determined their apoptotic activity in PC-3 cells. Apoptosis was assessed with four tests. RESULTS: In contrast to the effect of COX-2 inhibitors, which induced apoptosis, COX-2 depletion did not induce cell death. Susceptibility to COX-2 inhibitor-induced apoptosis was independent of the level of COX-2 expression. Structure-activity analysis found no correlation between apoptosis induction and COX-2 inhibition. Some celecoxib derivatives that lacked COX-2 inhibitory activity facilitated apoptosis and vice versa. Moreover, celecoxib and apoptosis-active celecoxib derivatives mediated cell death by inhibiting the same pathway. CONCLUSION: We have dissociated the apoptosis-inducing activity from the COX-2 inhibitory activity by structural modifications of the COX-2 inhibitor celecoxib. This separation of activities may provide a molecular basis for the development of new classes of apoptosis-inducing agents.     

Retrospective study of erlotinib in patients with advanced squamous lung cancer

Background: The effective targeted therapy for lung squamous cell carcinoma (SCC) is needed. The epidermal growth factor receptor (EGFR) mutation rate is low in lung SCC. The aim of this study was to evaluate the status of erlotinib treatment and EGFR mutation in lung SCC patients.Methods: We retrospectively enrolled lung cancer patients with SCC histology and history of erlotinib treatment. The primary objective was to assess overall response rate (ORR) and disease control rate (DCR) and the secondary objective was to assess progression-free survival (PFS) and overall survival (OS). EGFR mutations were assessed in parts of patients using both direct sequencing and protein nucleic acid-locked nucleic acid polymerase chain reaction (PNA-LNA PCR) clamp methods.Results: In total, 92 patients were analyzed (75 men and 17 women, median age 69 years, and 74 current or former smokers). Sixteen patients achieved partial response and 9 had stable disease. The ORR was 17.4% and the DCR was 27.2%. The PFS and OS were longer in patients with disease control than with progressive disease (PFS 7.8 versus 1.3 months and OS 20.7 versus 2.7 months, both p < 0.0001). The 1-year survival rate was 21.7%. In 27 patients with adequate specimens for molecular analysis (including 4 PR and 4 SD), two (7.4%) had EGFR complex mutations. One patient experienced response to erlotinib and the other did not.Conclusions: A significant proportion of lung SCC patients would derive a clinical benefit from erlotinib treatment. The relatively higher response rate than the EGFR mutation rate in present study needs further evaluation.     

Anticancer chemosensitivity profile of freshly separated human pancreatic cancer cells assessed by DNA synthesis inhibition assay

The chemosensitivity of 49 freshly separated human pancreatic cancers to seven kinds of anticancer agents were assessed by a DNA synthesis (³H-thymidine incorporation) inhibition assay. DNA synthesis is higher in involved lymph nodes (n=7), malignant effusion (n=15), liver metastasis (n=7), primary cancer (n=15), and skin metastasis (n=5). Chemosensitivity assay demonstrates that etoposide, 4-epirubicin, carboquone, and 5-fluorouracil are more effective than cisplatin, mitomycin-C, and Adriamycin. In general, metastatic lesions of pancreatic cancer tend to show higher chemosensitivity than primary lesions. Pathological analysis demonstrates that small primary pancreatic cancers tend to be more responsive than large primary cancers, and primary pancreatic cancers with no regional lymph node involvement also tend to be more responsive than those with nodal involvement. No significant differences are seen in terms of tumor spread, vascular involvement, sex of patient, and histological type. When chemosensitivity assay is not available, the results of the present study may be beneficial to choose the regimens. © 1994 Wiley-Liss, Inc.