Enhancing classical swine fever virus identification: the advantages of Field-LAMP testing

Classical swine fever virus (CSFV) identification has witnessed significant advancements with the development of rapid reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assays. However, conventional RT-LAMP assays for CSFV diagnosis are hindered by a laborious RNA extraction step. Moreover, the need for thermal incubators and expensive micropipettes has limited their application in field settings. Addressing these challenges, our study presents a groundbreaking solution-an electro-free and point-of-care (POC) tool known as the field-LAMP assay-for the rapid clinical detection of CSFV. By eliminating the RNA extraction requirement, advancing the colorimetric read-out and lyophilized reaction reagents, our field-LAMP assay streamlines the diagnostic process, saving valuable time and effort. This novel approach also overcomes the dependency on electric-dependent thermal incubators and expensive micropipettes, making it practical and accessible for use in the field. The successful development of the field-LAMP assay marks a significant milestone in CSFV detection. This electro-free and POC tool offers several advantages, including its ability to deliver rapid results without compromising accuracy, facilitating prompt response and containment measures.

Migration of Hydride, Methyl, and Chloride Ligands between Al and M in (PAlP)M Pincer Complexes (M = Rh or Ir)

Protolysis of AlMe3 or AlBui3 with 2-diisopropylphosphinopyrrole (1) yields molecules containing two flanking phosphines and a central Al-Me (2-Me), Al-iBu (2-iBu), or Al-H (2-H) unit. The reactions of 2-Me with [L2MCl]2 (L = cyclooctene or 1/2 1,5-cyclooctadiene and M = Rh or Ir) in the presence of pyridine produces PAlClP pincer complexes (3-Rh and 3-Ir) with Al-Cl and M-Me bonds. The analogous reaction of a mixture of 2-iBu and 2-H with [L2MCl]2 and pyridine resulted in the formation of analogous Rh-H (4-Rh) and Ir-H (4-Ir) complexes. Treatment of 3-Rh with NaBEt3H produced compound 5-Rh with an Al-Me and a Rh-H bond; the analogous reaction of 3-Ir did not result in a clean product. 4-Ir accepted an equivalent of H2 to produce 6-Ir with two terminal Ir-H bonds and one bridging Al-H-Ir moiety, whereas 4-Rh did not react with H2. The density functional theoretical treatment is in accord with this finding, highlights the likely mechanism for the H2 addition, and supports the bonding picture in 6-Ir arising from NMR and X-ray diffraction (XRD) observations. Spectroscopic data and XRD studies are consistent with distorted square-pyramidal structures (about Rh or Ir) for compounds 3-5, with an alane occupying the apical position. Complexes 3 and 4 possess some of the shortest known Rh-Al or Ir-Al distances.

Biomedical doctoral students' research practices when facing dilemmas: two vignette-based randomized control trials

Our aim was to describe the research practices of doctoral students facing a dilemma to research integrity and to assess the impact of inappropriate research environments, i.e. exposure to (a) a post-doctoral researcher who committed a Detrimental Research Practice (DRP) in a similar situation and (b) a supervisor who did not oppose the DRP. We conducted two 2-arm, parallel-group randomized controlled trials. We created 10 vignettes describing a realistic dilemma with two alternative courses of action (good practice versus DRP). 630 PhD students were randomized through an online system to a vignette (a) with (n = 151) or without (n = 164) exposure to a post-doctoral researcher; (b) with (n = 155) or without (n = 160) exposure to a supervisor. The primary outcome was a score from - 5 to + 5, where positive scores indicated the choice of DRP and negative scores indicated good practice. Overall, 37% of unexposed participants chose to commit DRP with important variation across vignettes (minimum 10%; maximum 66%). The mean difference [95%CI] was 0.17 [- 0.65 to 0.99;], p = 0.65 when exposed to the post-doctoral researcher, and 0.79 [- 0.38; 1.94], p = 0.16, when exposed to the supervisor. In conclusion, we did not find evidence of an impact of postdoctoral researchers and supervisors on student research practices.Trial registration: NCT04263805, NCT04263506 (registration date 11 February 2020).

Brachial Plexus Nerve Injuries and Disorders

Multimodality imaging of the brachial plexus is essential to accurately localize the lesion and characterize the pathology and site of injury. A combination of computed tomography (CT), ultrasound, and MR imaging is useful along with clinical and nerve conduction studies. Ultrasound and MR imaging in combination are effective to accurately localize the pathology in most of the cases. Accurate reporting of the pathology with dedicated MR imaging protocols in conjunction with Doppler ultrasound and dynamic imaging provides practical and useful information to help the referring physicians and surgeons to optimize medical or surgical treatment regimens.

Individual-level permethrin exposure biomarkers in U.S. army soldiers: comparison of two treatment formulations for military uniforms

BACKGROUND

Evidence suggests that wearing permethrin-treated military uniforms is not associated with current adverse health conditions. However, exposure through this route results in permethrin biomarker concentrations considerably higher than those in the U.S.

POPULATION

The U.S. Army is exploring different methods of uniform treatment that reduce exposure while maintaining effective protection from insect vector-borne diseases.

OBJECTIVE

To compare permethrin exposure when wearing two types of permethrin-treated military uniforms.

METHODS

Eight male soldiers participated in a 32-day crossover design study to compare permethrin exposure when wearing the current Army uniform (CurrU) and a uniform with a new applied fabric treatment (NewU). Each soldier wore the uniforms for designated 8 h/day time periods over 3 consecutive days separated by a 'wash-out' week of no exposure. Permethrin exposure was assessed from the urinary concentrations of 3-phenoxybenzoic acid (3-PBA) and of the sum of cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (∑DCCA). Estimated dose was determined based on ∑DCCA concentrations.

RESULTS

Permethrin exposure biomarkers were 21% (3-PBA, p = 0.025) and 35% (∑DCCA, p < 0.001) lower when wearing the NewU compared to the CurrU; the dose was 33% lower (p = 0.05).

SIGNIFICANCE

Findings suggest the new treatment reduces human permethrin exposure biomarkers resulting from wearing-treated military uniforms.

Distinct modes of Si-H binding to Rh in complexes of a phosphine-diarylamido-silane (SiNP) pincer ligand

Syntheses of Rh complexes of the phosphine-amido-silane SiNP ligand are reported. The reaction of the parent (SiNP)H ligand (4) with 0.5 equiv. [(COE)RhCl]₂ (COE = cis-cyclooctene) in the presence of NaN(SiME₃)₂ resulted in the formation of (SiNP)Rh(COE) (5). Compound 5 was converted to a series of (SiNP)Rh(P(OR)₃) complexes 6-10 (R = Ph, ⁱPr, ⁿBu, Et, or Me) by treatment with the corresponding phosphite. NMR and XRD structural data, as well as the DFT computational analysis indicate that compounds 5-10 are divided into two structural Types (A and B), differing in the nature of the interaction of the Si-H bond of the SiNP ligand with Rh.

The perceptions of social media users of digital detox apps considering personality traits

The purpose of this study was to investigate the perceptions of users about using digital detox applications and to display relationships among personality traits and technology-related variables. This study was designed using survey approach and employed Generalized Structured Component Analysis (GSCA). As such, 11 hypotheses were constructed and tested. The study recruited 263 participants who utilize detox applications to avoid social media distractions. Data were collected through Google Form and analyzed using GSCA Pro 1.1 to better understand whether the proposed conceptual model fits the data. The results of the study indicated that behavioral intention predicted usage behavior significantly; performance expectancy, effort expectancy, and social influence positively affected behavioral intention; in turn, agreeableness and extroversion positively influenced performance expectancy, and extroversion affected effort expectancy; finally, neuroticism had a statistically significant and negatively associated with effort expectancy of using social media detox apps. The significant exceptions were that facilitating conditions were not predictive of behavioral intention, openness to experience did not influence performance expectancy, and conscientiousness was not linked to effort expectancy. The proposed conceptual model explained 56.68% of the amount of variation, indicating that instructors, policy makers and software designers should consider personal factors for preparing practical intervention approaches to mitigate learning issues related to social media distraction.

Increasing sample diversity in psychiatric genetics - Introducing a new cohort of patients with schizophrenia and controls from Vietnam - Results from a pilot study

OBJECTIVES

Genome-Wide Association Studies (GWAS) of Schizophrenia (SCZ) have provided new biological insights; however, most cohorts are of European ancestry. As a result, derived polygenic risk scores (PRS) show decreased predictive power when applied to populations of different ancestries. We aimed to assess the feasibility of a large-scale data collection in Hanoi, Vietnam, contribute to international efforts to diversify ancestry in SCZ genetic research and examine the transferability of SCZ-PRS to individuals of Vietnamese Kinh ancestry.

METHODS

In a pilot study, 368 individuals (including 190 SCZ cases) were recruited at the Hanoi Medical University's associated psychiatric hospitals and outpatient facilities. Data collection included sociodemographic data, baseline clinical data, clinical interviews assessing symptom severity and genome-wide SNP genotyping. SCZ-PRS were generated using different training data sets: (i) European, (ii) East-Asian and (iii) trans-ancestry GWAS summary statistics from the latest SCZ GWAS meta-analysis.

RESULTS

SCZ-PRS significantly predicted case status in Vietnamese individuals using mixed-ancestry (R² liability = 4.9%, p = 6.83 × 10^-8), East-Asian (R² liability = 4.5%, p = 2.73 × 10^-7) and European (R² liability = 3.8%, p = 1.79 × 10^-6) discovery samples.

DISCUSSION

Our results corroborate previous findings of reduced PRS predictive power across populations, highlighting the importance of ancestral diversity in GWA studies.

Evaluation of Undiagnosed HIV Estimates Computed from the CD4 Depletion Model in a Rural, Medium-low HIV Prevalence State

The CD4 depletion model estimates diagnosis delays by approximating infection date from CD4 T-cell count at diagnosis, and back-calculation can compute the proportion of undiagnosed PLWHA. The model assumes the immigration of PLWHA to the U.S. is negligible and counts as a transmission event, which may be impractical outside high prevalence states. Duration of U.S. residency among foreign-born PLWHA and diagnosis delays were compared. The impact on estimates of undiagnosed PLWHA was tested through simulation with different proportions of foreign-born people assumed to have acquired HIV abroad. In 67% of foreign-born people, the mean (SD) years of delay (9.9 (6.3)) exceeded the duration of U.S. residency (2.0 (1.9)). Additionally, inaccuracies in the estimates for proportions of undiagnosed PLWHA were pronounced when foreign-born people who acquired HIV abroad comprised 30% of diagnoses. The CD4 model inadvertently misclassified some diagnoses as in-state transmission events. Consequently, simulated results demonstrated inaccuracies and unstable calculations.

Insula cortex gates the interplay of action observation and preparation for controlled imitation

Perceiving, anticipating and responding to the actions of another person are fundamentally entwined processes such that seeing another's movement can prompt automatic imitation, as in social mimicry and contagious yawning. Yet the direct-matching of others' movements is not always appropriate, so this tendency must be controlled. This necessitates the hierarchical integration of the systems for action mirroring with domain-general control networks. Here we use functional magnetic resonance imaging (fMRI) and computational modelling to examine the top-down and context-dependent modulation of mirror representations and their influence on motor planning. Participants performed actions that either intentionally or incidentally imitated, or counter-imitated, an observed action. Analyses of these fMRI data revealed a region in the mid-occipital gyrus (MOG) where activity differed between imitation versus counter-imitation in a manner that depended on whether this was intentional or incidental. To identify broader cortical network mechanisms underlying this interaction between intention and imitativeness, we used dynamic causal modelling to pose specific hypotheses which embody assumptions about inter-areal interactions and contextual modulations. These models each incorporated four regions - medial temporal V5 (early motion perception), MOG (action-observation), supplementary motor area (action planning), and anterior insula (executive control) - but differ in their interactions and hierarchical structure. The best model of our data afforded a crucial role for the anterior insula, gating the interaction of supplementary motor area and MOG activity. This provides a novel brain network-based account of task-dependent control over the integration of motor planning and mirror systems, with mirror responses suppressed for intentional counter-imitation.

Feasibility, safety and long term outcomes of complex left main bifurcation treatment using the nano inverted t stenting: a multicentre registry

Background

The role of double stenting techniques in distal bifurcation left main (LM) disease has gaining interest over the latest years.

Purpose

We present the 3-year multicentre registry outcomes of dual stenting using ultra-thin strut stents and the Nano Inverted-T (NIT) technique in complex unprotected true LM bifurcation disease.

Methods

We analysed the procedural and medical data of consecutive patients enrolled between 1st January 2014 and 1st December 2019 in a multicentre registry for complex LM bifurcation disease treated with the double stenting technique called NIT due contraindications and/or refusal to surgical treatment. Target lesion failure (TLF) was defined as the composite of cardiovascular death, target-vessel MI (TVMI) and clinically driven target lesion revascularization (TLR).

Results

Among two hundred-ninety-five patients (138 males, mean age 70.3±12.8 years), post-operative success was achieved in 100% of cases. Contrast volume, procedural time, and radiation exposure were 139.2±23.4 ml, 15.3±4.9 min, and 1080±1034 cGy/m2 (Figure), respectively. At a mean follow-up of 39.5±0.6 months TLF rate was 6.1% (n=18) while TLR and cardiovascular mortality rates were 3.0 (n=9) and 2.6% (n=8), respectively. Clinically driven angiographic follow-up was available in 26.4% of patients at a mean time from the procedure of 7.5±0.4 months. Clinically restenosis rate was 3.3%.

Conclusions

Revascularization of complex LM bifurcation disease using the NIT double stenting technique resulted feasible and safe with a low incidence of TLF, excellent survival rate and no stent thrombosis. Figure 1.The NIT technique is based on the use of ultra-thin strut (≤80 micron) stents and double stenting starting with side branch stenting frst. The side branch stent is precisely positioned with one possibly only strut protruding into the main vessel which is balloon crushed before the implantation of the main branch stenting. The Proximal optimization technique (POT)–snuggle kissing–POT sequence is mandatory to ensure the coverage of the side branch ostium by both side branch and main branch stents. Snuggle kissing was performed placing the LCX balloon with the proximal marker at the middle rather than at the proximal marker of the LM-LAD balloon, in order to minimize the elliptical deformation of the LM stent.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Narratives of Undergraduate Research, Mentorship, and Teaching at UCLA

This work describes select narratives pertaining to undergraduate teaching and mentorship at UCLA Chemistry and Biochemistry by Alex Spokoyny and his junior colleagues. Specifically, we discuss how individual undergraduate researchers contributed and jump-started multiple research themes since the conception of our research laboratory. This work also describes several recent innovations in the inorganic and general chemistry courses taught by Spokoyny at UCLA with a focus of nurturing appreciation for research and creative process in sciences including the use of social media platforms.

Intracranial-EEG evidence for medial temporal pole driving amygdala activity induced by multi-modal emotional stimuli

The temporal pole (TP) is an associative cortical region required for complex cognitive functions such as social and emotional cognition. However, mapping the TP with functional magnetic resonance imaging is technically challenging and thus understanding its interaction with other key emotional circuitry, such as the amygdala, remains elusive. We exploited the unique advantages of stereo-electroencephalography (sEEG) to assess the responses of the TP and the amygdala during the perception of emotionally salient stimuli of pictures, music and movies. These stimuli consistently elicited high gamma responses (70-140 Hz) in both the TP and the amygdala, accompanied by functional connectivity in the low frequency range (2-12 Hz). Computational analyses suggested that the TP drove this effect in the theta frequency range, modulated by the emotional valence of the stimuli. Notably, cross-frequency analysis indicated the phase of theta oscillations in the TP modulated the amplitude of high gamma activity in the amygdala. These results were reproducible across three types of sensory inputs including naturalistic stimuli. Our results suggest that multimodal emotional stimuli induce a hierarchical influence of the TP over the amygdala.

New species and new genus of Pseudohaploporinae (Digenea): Pseudohaploporus pusitestis sp. n. and Parahaploporus elegantus n. g., sp. n. (Digenea: Pseudohaploporinae) from Vietnamese mullet fish

Two new species of Pseudohaploporinae, Pseudohaploporus pusitestis sp. n. and Parahaploporus elegantus n. g., sp. n., are described from intestines of the Vietnamese mullet fish Moolgarda seheli and Osteomugil cunnesius, respectively. Pseudohaploporus pusitestis sp. n. differs from two known Pseudohaploporus species, P. vietnamensis and P. planiliza, by the absence of a diverticulate hermaphroditic duct and muscular sphincters at the proximal end of the hermaphroditic sac. Metrically, P. pusitestis sp. n. is close to P. vietnamensis and differs from this species and from P. planilizum by lower maximum sizes of most parameters. Parahaploporus elegantus n. g., sp. differs from representatives of Pseudohaploporus by the presence of a single testis and the armament of hermaphroditic duct and is morphologically close to trematodes of the genus Haploporus. However, P. elegantus n. g differs from all known Haploporus species from mugilids of the Indo-West Pacific by the structure of the armament of the hermaphroditic duct and also by size of body, organs and eggs. The validity of designating two new species and a new genus of trematodes is supported by ITS and 28S rDNA sequence data. Phylogenetic reconstructions showed that the new trematodes belong to the Pseudohaploporinae, which formed a well-supported cluster within the monophyletic Haploporidae.

Learners’ Technological Acceptance of VR Content Development: A Sequential 3-Part Use Case Study of Diverse Post-Secondary Students

Web-based virtual reality (VR) development tools are in ubiquitous use by software developers, and now, university (undergraduate) students, to move beyond using, to creating new and energizing VR content. Web-based VR (WebVR), among other libraries and frameworks, have risen as a low-cost platform for users to create rich and intuitive VR content and applications. However, the success of WebVR as an instructional tool relies on post-secondary students technological acceptance (TA), the intersectionality of a user’s perceived utility (PU) and perceived ease of use (PEOU, or convenience) with said technological tool. Yet, there is a dearth of exploratory studies of students’ experiences with the AR/VR development technologies to infer their TA. To ascertain the viability of WebVR tools for software engineering undergraduates in the classroom, this paper presents a 3-case contextual investigation of 38 undergraduate students tasked with creating VR content. In each use case, students were provided increasing freedom in their VR content development parameters. Results indicated that students demonstrated elements of technological acceptance in their selection of webVR and other platforms, and not only successfully creating rich and robust VR content (PU), but also executing these projects in a short period (PEOU). Other positive externalities observed were students exhibitions of soft skills (e.g. creativity, critical thinking) and different modes of demonstrating coding knowledge, which suggest further study. Discussed are the lessons learned from the WebVR and VR/AR interventions and recommendations for WebVR instruction. This work may be helpful for both learners and teachers using VR/AR in selecting, designing, and developing coursework materials, tools, and libraries.

Decorin age-related variations in the distribution of pig extracellular matrix meniscus

Menisci act like shock absorbers and transmit load across the tibiofemoral joint by increasing congruency during movements or body weight load. This leads to decreasing the resultant stress on the articular cartilages. The meniscus has a dense extracellular matrix (ECM) composed of water, different types of collagens, and proteoglycans, such as decorin, aggrecan and biglycan. Decorin (DCN) regulates collagen fibrillogenesis acting on collagen fibrils diameter and fibrils orientation to achieve the proper assembly of its network. This work investigates the spatial disposition of this fundamental protein in pig meniscus' matrix by immunohistochemistry and western blot analysis. DCN shows an increasing trend, moving from neonatal to adult pig menisci. Adult meniscus, in porcine species, is the only one that could be considered fully mature and functional, and, even if an increasing trend is seen, no precise phenotypical switch points are seen in the age stages considered in this study.

Effective connectivity of the anterior hippocampus predicts recollection confidence during natural memory retrieval

Human interactions with the world are influenced by memories of recent events. This effect, often triggered by perceptual cues, occurs naturally and without conscious effort. However, the neuroscience of involuntary memory in a dynamic milieu has received much less attention than the mechanisms of voluntary retrieval with deliberate purpose. Here, we investigate the neural processes driven by naturalistic cues that relate to, and presumably trigger the retrieval of recent experiences. Viewing the continuation of recently viewed clips evokes greater bilateral activation in anterior hippocampus, precuneus and angular gyrus than naïve clips. While these regions manifest reciprocal connectivity, continued viewing specifically modulates the effective connectivity from the anterior hippocampus to the precuneus. The strength of this modulation predicts participants' confidence in later voluntary recall of news details. Our study reveals network mechanisms of dynamic, involuntary memory retrieval and its relevance to metacognition in a rich context resembling everyday life.

Characterization of different in vitro culture conditions to induce a fibro-chondrogenic differentiation of swine adipose-derived stem cells

Meniscus repair is still a challenge for orthopaedic surgeons as this tissue has a scarce healing potential due to the limited vascularization and to the lack of progenitor cells. Lately, several tissue engineering strategies combining cells and scaffolds have been developed. Adipose-derived stem cells (ASCs) represent a novel cell source for meniscus repair as they are easy to harvest, and they possess an intrinsic chondrogenic potential. The aim of our study was to analyze and compare the chondrogenic differentiation of swine ASCs cultured in vitro with different supplemented media. We isolated ASCs from swine adipose tissue and we placed in pellet cultures supplemented with either Bone Morphogenetic Protein (BMP)-2 and Transforming Growth Factor (TGF)-β3 or with Bone Morphogenetic Protein (BMP)-7 and Transforming Growth Factor (TGF)-β1. Samples were analyzed after 7, 14 or 21 days of culture by biochemical, histological and gene expression analysis. Our preliminary results show that BMP-2 and TGF-β3 are stronger inducers of chondrogenesis.

Animal models for cartilage repair

Cartilage lesions still represent an unsolved problem: despite the efforts of the basic and translational research, the regeneration of this tissue is far from being reached (1-3). Articular cartilage lesions can be divided in two main groups: superficial or partial defects and full-thickness defects (4, 5). Partial lesions are not able to self-heal because multipotent cells from the bone marrow cannot reach the area leading to a progressive degeneration of the tissue (6). Conversely, full-thickness injuries possess greater chances to heal because subchondral bone involvement allows for the migration of mesenchymal cells, which fill the damaged area (7, 8). However, healing occurs through the formation of a fibrocartilaginous tissue, which has different biomechanical and biological properties (9). Native hyaline cartilage has indeed specific biomechanical properties, which confer resistance to compressive and shear stresses; the reparative fibrocartilaginous tissue lacks these abilities, therefore, the surrounding healthy cartilage progressively degenerates. In the past years, several therapeutic strategies have been developed to restore the damaged cartilage, bone marrow stimulation (chondroabrasion, drilling, micro- or nano-fractures) and more recently, tissue engineering approaches (10-14). Some of these latter procedures have already been applied in clinical practice such as matrix-induced autologous chondrocyte implantation (MACI) (15) or osteochondral scaffold implantation (16). Generally, tissue engineering approaches are based on the combination of three main elements: cells (i.e. primary chondrocytes or multipotent mesenchymal cells), biocompatible scaffolds (i.e. polymers, composites, ceramics) and signaling molecules (i.e. growth factors). Moreover, several culture conditions (i.e. static or dynamic cultures) and biomechanical stimuli can be applied during the in vitro culture to promote tissue maturation (17-19). However, an in vivo culture is mandatory to validate a new engineered construct as the in vitro phase lacks the essential in vivo environmental stimuli and because the in vivo culture allows for the testing of the biocompatibility and safety of a new material (18, 19). Moreover, preclinical animal models are crucial to understand the molecular mechanisms of cartilage lesions favoring the development of new regenerative strategies (20, 21). in vivo studies on animal models should focus on the analysis of the cellular component, analyzing the maintenance of the cellular phenotype and the tumorigenicity; on the evaluation of the biocompatibility, toxicity and degradation of the biomaterial and on the assessment of the engineered construct. In this manuscript, we will review the most common preclinical animal models, which are used to understand cartilage biology and therefore to develop new tissue engineering strategies. We will focus on both small and large animal models highlighting their peculiarities, advantages and drawbacks.

Validity, reliability, and responsiveness to change of the "Osteoporosis and You" knowledge scale

We studied the Osteoporosis and You knowledge scale in 7749 participants enrolled in a clinical trial. Results confirmed its psychometric properties in a diverse audience. Baseline scores were associated with better recall of bone mineral density test results at follow-up; however, the scale was not responsive to knowledge change.

INTRODUCTION

The goal of this study was to confirm the measurement properties of the Osteoporosis and You (O&Y) knowledge scale using classic test theory methods in the 7749 men and women participating in the Patient Activation After DXA Result Notification (PAADRN) randomized controlled trial. We hypothesized a simple factor structure that would reflect the four-factor model previously published.

METHODS

We conducted psychometric analyses which included item analysis, internal consistency reliability, construct validity using exploratory and confirmatory factor analysis (EFA and CFA), comparing knowledge levels across pre-specified groups, and responsiveness to change.

RESULTS

PAADRN participants were predominantly college educated, White females with low bone density, and a moderate level of 10-year fracture risk. EFA revealed four domains closely matching those in two previous reports. While overall scale reliability was minimally acceptable at 0.68, the reliabilities of the domain subscales were unacceptably low (0.59, 0.64, 0.45, and 0.36 for the Biological, Lifestyle, Consequences, and Prevention and Treatment subscales). CFA revealed the data fit the hypothesized model reasonably well with the items loading on their expected latent variable. The scale was not responsive to change, but although not significant, improved knowledge indicated better DXA result recall at 12 and 52 weeks.

CONCLUSIONS

In the PAADRN population, the O&Y knowledge scale had psychometric properties similar to those previously reported. Over 12 and 52 weeks, participants did not demonstrate significant changes in knowledge, but those with higher knowledge at baseline were more likely to accurately recall their baseline DXA result.

Improving the Test-Retest Reliability of Resting State fMRI by Removing the Impact of Sleep

Resting state functional magnetic resonance imaging (rs-fMRI) provides a powerful tool to examine large-scale neural networks in the human brain and their disturbances in neuropsychiatric disorders. Thanks to its low demand and high tolerance, resting state paradigms can be easily acquired from clinical population. However, due to the unconstrained nature, resting state paradigm is associated with excessive head movement and proneness to sleep. Consequently, the test-retest reliability of rs-fMRI measures is moderate at best, falling short of widespread use in the clinic. Here, we characterized the effect of sleep on the test-retest reliability of rs-fMRI. Using measures of heart rate variability (HRV) derived from simultaneous electrocardiogram (ECG) recording, we identified portions of fMRI data when subjects were more alert or sleepy, and examined their effects on the test-retest reliability of functional connectivity measures. When volumes of sleep were excluded, the reliability of rs-fMRI is significantly improved, and the improvement appears to be general across brain networks. The amount of improvement is robust with the removal of as much as 60% volumes of sleepiness. Therefore, test-retest reliability of rs-fMRI is affected by sleep and could be improved by excluding volumes of sleepiness as indexed by HRV. Our results suggest a novel and practical method to improve test-retest reliability of rs-fMRI measures.

Relationship of galectin-3 with obesity, IL-6, and CRP in women

PURPOSE

To evaluate the association of galectin-3 (Gal3) with obesity and inflammatory status in a cohort of metabolically healthy, predominantly African-American women with varying cardiovascular disease (CVD) risk as determined by CRP levels.

METHODS

We assessed the association between BMI and serum levels of Gal3, IL-6, CRP, and adiponectin in metabolically healthy women (N = 97) to determine the overall association between Gal3, obesity, and inflammation in groups at different CVD risk.

RESULTS

Obese women had significantly higher serum Gal3 compared to non-obese participants (P = 0.0016), although Gal3 levels were comparable among different classes of obesity. BMI (R ² = 0.1406, P = 0.0013), IL-6 (R ² = 0.0689, P = 0.035), and CRP (R ² = 0.0468, P = 0.0419), but not adiponectin, positively predicted the variance of Gal3 levels in the total study population. However, the predicting effect of BMI (R ² = 0.2923, P = 0.0125) and inflammation (R ² = 0.3138, P = 0.038) on Gal3 was only present in women at low/moderate risk of CVD (CRP ≤ 3 µg/mL).

CONCLUSIONS

Gal3 is positively correlated with obesity and inflammation in women, while the presence of elevated CVD risk may disturb the strength of Gal3 as a biomarker of inflammation.

Blue Phosphorescent Zwitterionic Iridium(III) Complexes Featuring Weakly Coordinating nido-Carborane-Based Ligands

We report the development of a new class of phosphorescent zwitterionic bis(heteroleptic) Ir(III) compounds containing pyridyl ligands with weakly coordinating nido-carboranyl substituents. Treatment of phenylpyridine-based Ir(III) precursors with C-substituted ortho-carboranylpyridines in 2-ethoxyethanol results in a facile carborane deboronation and the formation of robust and highly luminescent metal complexes. The resulting nido-carboranyl fragments associate with the cationic Ir(III) center through primarily electrostatic interactions. These compounds phosphoresce at blue wavelengths (450-470 nm) both in a poly(methyl methacrylate) (PMMA) matrix and in solution at 77 K. These complexes display structural stability at temperatures beyond 300 °C and quantum yields greater than 40%. Importantly, the observed quantum yields correspond to a dramatic 10-fold enhancement over the previously reported Ir(III) congeners featuring carboranyl-containing ligands in which the boron cluster is covalently attached to the metal. Ultimately, this work suggests that the use of a ligand framework containing a weakly coordinating anionic component can provide a new avenue for designing efficient Ir(III)-based phosphorescent emitters.

A hierarchy of timescales explains distinct effects of local inhibition of primary visual cortex and frontal eye fields

Within the primate visual system, areas at lower levels of the cortical hierarchy process basic visual features, whereas those at higher levels, such as the frontal eye fields (FEF), are thought to modulate sensory processes via feedback connections. Despite these functional exchanges during perception, there is little shared activity between early and late visual regions at rest. How interactions emerge between regions encompassing distinct levels of the visual hierarchy remains unknown. Here we combined neuroimaging, non-invasive cortical stimulation and computational modelling to characterize changes in functional interactions across widespread neural networks before and after local inhibition of primary visual cortex or FEF. We found that stimulation of early visual cortex selectively increased feedforward interactions with FEF and extrastriate visual areas, whereas identical stimulation of the FEF decreased feedback interactions with early visual areas. Computational modelling suggests that these opposing effects reflect a fast-slow timescale hierarchy from sensory to association areas.

DOI:http://dx.doi.org/10.7554/eLife.15252.001

In humans, the parts of the brain involved in vision are organized into distinct regions that are arranged into a hierarchy. Each of these regions contains neurons that are specialized for a particular role, such as responding to shape, color or motion. To actually ‘see’ an object, these different regions must communicate with each other and exchange information via connections between lower and higher levels of the hierarchy. However, it remains unclear how these connections work.

A brain region called the primary visual cortex is the lowest level of the visual cortical hierarchy as it is the first area to receive information from the eye. This region then passes information to higher regions in the hierarchy including the frontal eye fields (FEF), which help to control visual attention and eye movements. In turn, the FEF is thought to provide ‘feedback’ to the primary visual cortex.

Cocchi et al. examined how the FEF and primary visual cortex communicate with the rest of the brain by temporarily inhibiting the activity of these regions in human volunteers. The experiments show that inhibiting the primary visual cortex increased communication between this region and higher level visual areas. On the other hand, inhibiting the FEF reduced communication between this region and lower visual areas.

Computer simulations revealed that inhibiting particular brain regions alters communication between visual regions by changing the timing of local neural activity. In the simulations, inhibiting the primary visual cortex slows down neural activity in that region, leading to better communication with higher regions, which already operate on slower timescales. By contrast, inhibition of the FEF reduces its influence on lower visual regions by increasing the difference in timescales of neural activity between these regions.

The next step is to determine whether similar mechanisms regulate changes in the activity of neural networks outside of the visual system.

DOI:http://dx.doi.org/10.7554/eLife.15252.002

Surface Dipole Control of Liquid Crystal Alignment

Detailed understanding and control of the intermolecular forces that govern molecular assembly are necessary to engineer structure and function at the nanoscale. Liquid crystal (LC) assembly is exceptionally sensitive to surface properties, capable of transducing nanoscale intermolecular interactions into a macroscopic optical readout. Self-assembled monolayers (SAMs) modify surface interactions and are known to influence LC alignment. Here, we exploit the different dipole magnitudes and orientations of carboranethiol and -dithiol positional isomers to deconvolve the influence of SAM-LC dipolar coupling from variations in molecular geometry, tilt, and order. Director orientations and anchoring energies are measured for LC cells employing various carboranethiol and -dithiol isomer alignment layers. The normal component of the molecular dipole in the SAM, toward or away from the underlying substrate, was found to determine the in-plane LC director orientation relative to the anisotropy axis of the surface. By using LC alignment as a probe of interaction strength, we elucidate the role of dipolar coupling of molecular monolayers to their environment in determining molecular orientations. We apply this understanding to advance the engineering of molecular interactions at the nanoscale.

Distinct neurobiological signatures of brain connectivity in depression subtypes during natural viewing of emotionally salient films

BACKGROUND

Establishing an evidence-based diagnostic system informed by the biological (dys)function of the nervous system is a major priority in psychiatry. This objective, however, is often challenged by difficulties in identifying homogeneous clinical populations. Melancholia, a biological and endogenous subtype for major depressive disorder, presents a canonical test case in the search of biological nosology.

METHOD

We employed a unique combination of naturalistic functional magnetic resonance imaging (fMRI) paradigms - resting state and free viewing of emotionally salient films - to search for neurobiological signatures of depression subtypes. fMRI data were acquired from 57 participants; 17 patients with melancholia, 17 patients with (non-melancholic) major depression and 23 matched healthy controls.

RESULTS

Patients with melancholia showed a prominent loss of functional connectivity in hub regions [including ventral medial prefrontal cortex, anterior cingulate cortex (ACC) and superior temporal gyrus] during natural viewing, and in the posterior cingulate cortex while at rest. Of note, the default mode network showed diminished reactivity to external stimuli in melancholia, which correlated with the severity of anhedonia. Intriguingly, the subgenual ACC, a potential target for treating depression with deep brain stimulation (DBS), showed divergent changes between the two depression subtypes, with increased connectivity in the non-melancholic and decreased connectivity in the melancholic subsets.

CONCLUSION

These findings reveal neurobiological changes specific to depression subtypes during ecologically valid behavioural conditions, underscoring the critical need to respect differing neurobiological processes underpinning depressive subtypes.

Scene unseen: Disrupted neuronal adaptation in melancholia during emotional film viewing

Impairments in attention and concentration are distinctive features of melancholic depression, and may diminish the ability to shift focus away from internal dysphoric states. Disrupted brain networks may underlie the inability to effectively disengage from interoceptive signals in this disorder. This study investigates changes in effective connectivity between cortical systems supporting attention, interoception, and perception in those with melancholic depression when shifting attention from rest to viewing dynamic film stimuli. We hypothesised that those with melancholia would show impaired attentional shifting from rest to emotional film viewing, captured in neuronal states that differed little across conditions. Functional magnetic resonance imaging (fMRI) data were acquired from 48 participants (16 melancholic depressed, 16 non-melancholic depressed, and 16 healthy controls) at rest and whilst viewing emotionally salient movies. Using independent component analysis, we identified 8 cortical modes (default mode, executive control, left/right frontoparietal attention, left/right insula, visual and auditory) and studied their dynamics using dynamic causal modelling. Engagement with dynamic emotional material diminished in melancholia and was associated with network-wide increases in effective connectivity. Melancholia was also characterised by an increase in effective connectivity amongst cortical regions involved in attention and interoception when shifting from rest to negative film viewing, with the converse pattern in control participants. The observed involvement of attention- and insula-based cortical systems highlights a potential neurobiological mechanism for disrupted attentional resource allocation, particularly in switching between interoceptive and exteroceptive signals, in melancholia.

Out-of-sync: disrupted neural activity in emotional circuitry during film viewing in melancholic depression

While a rich body of research in controlled experiments has established changes in the neural circuitry of emotion in major depressive disorders, little is known as to how such alterations might translate into complex, naturalistic settings--namely involving dynamic multimodal stimuli with rich contexts, such as those provided by films. Neuroimaging paradigms employing dynamic natural stimuli alleviate the anxiety often associated with complex tasks and eschew the need for laboratory-style abstractions, hence providing an ecologically valid means of elucidating neural underpinnings of neuropsychiatric disorders. To probe the neurobiological signature of refined depression subtypes, we acquired functional neuroimaging data in patients with the melancholic subtype of major depressive disorder during free viewing of emotionally salient films. We found a marked disengagement of ventromedial prefrontal cortex during natural viewing of a film with negative emotional valence in patients with melancholia. This effect significantly correlated with depression severity. Such changes occurred on the background of diminished consistency of neural activity in visual and auditory sensory networks, as well as higher-order networks involved in emotion and attention, including bilateral intraparietal sulcus and right anterior insula. These findings may reflect a failure to re-allocate resources and diminished reactivity to external emotional stimuli in melancholia.

Role of nitrification in the biodegradation of selected artificial sweetening agents in biological wastewater treatment process

The biodegradation of the six artificial sweetening agents including acesulfame (ACE), aspartame (ASP), cyclamate (CYC), neohesperidindihydrochalcone (NHDC), saccharin (SAC), and sucralose (SUC) by nitrifying activated sludge was first examined. Experimental results showed that ASP and NHDC were the most easily degradable compounds even in the control tests. CYC and SAC were efficiently biodegraded by the nitrifying activated sludge, whereas ACE and SUC were poorly removed. However, the biodegradation efficiencies of the ASs were increased with the increase in initial ammonium concentrations in the bioreactors. The association between nitrification and co-metabolic degradation was investigated and a linear relationship between nitrification rate and co-metabolic biodegradation rate was observed for the target artificial sweeteners (ASs). The contribution of heterotrophic microorganisms and autotrophic ammonia oxidizers in biodegradation of the ASs was elucidated, of which autotrophic ammonia oxidizers played an important role in the biodegradation of the ASs, particularly with regards to ACE and SUC.

Safety of EEG-fMRI recordings in newborn infants at 3T: a study using a baby-size phantom

OBJECTIVE

We aimed to study EEG electrode temperatures during MRI recordings using a neonatal-size phantom to establish the safety of neonatal EEG-MRI.

METHODS

We constructed a phantom set-up for co-registration of EEG and MRI measurements with newborn size configurations. The set-up consisted of a spherical glass phantom fitted with a customised MRI-compatible 64-channel EEG cap and EEG amplifier. Temperatures were recorded during and after five different scanning sequences (two T2∗ sensitised BOLD fMRI, one T1-weighted and two T2-weighted spin echo) in five electrode locations using a thermistor that was integrated into the electrode housing. A temperature increase >4°C was defined a priori as the safety limit.

RESULTS

During fMRI and T1 sequences, none of the electrodes showed meaningful temperature changes. Only one MRI sequence (T2 with Max turbo factor 25; SAR 89%) caused temperature increase in one electrode (Fpz; +4.1°C) that slightly exceeded our predefined safety limit, while the conventional T2 sequence was within safety limits (up to +1.7°C).

CONCLUSIONS

Co-registration of EEG and fMRI can be considered safe in babies with respect to electrode heating, which is the primary safety concern.

SIGNIFICANCE

The present findings open up a possibility to commence studies where EEG and MRI/fMRI are co-registered in human babies. Such studies hold significant promise of a better understanding of the early development of brain function and neurovascular coupling.

The superior temporal sulcus and the N170 during face processing: single trial analysis of concurrent EEG-fMRI

Face-selective neural signals have been reliably identified using both EEG and fMRI studies. These consist of the N170 component, a neural response peaking approximately 170ms after a face is presented, and face-selective activations in the fusiform face area (FFA), the occipital face area (OFA), and the superior temporal sulcus (STS). As most neuroimaging studies examine these face-selective processes separately, the relationship between the N170 neural response and activation in the fusiform gyrus is still debated. In this study, we concurrently measured EEG and fMRI responses to upright faces, inverted faces, and objects to examine this association. We introduce a method for single-trial estimation of N170 amplitudes and correlation of the trial-by-trial variation in N170 neural responses with fMRI BOLD responses. For upright faces, BOLD responses in the right STS were negatively correlated with N170 amplitudes, showing greater activation on trials in which N170 amplitudes were larger (more negative). For inverted faces, a medial region of the fusiform gyrus (mFG) was positively correlated with N170 amplitudes, showing greater activation on trials in which N170 amplitudes were smaller (less negative). This result points to the STS as a crucial region for generating the N170 associated with face perception, and suggests that the mFG is additionally recruited for processing inverted faces, particularly on trials in which N170 is small. Despite the different time resolution of fMRI and EEG signals, our single-trial estimation and EEG-fMRI correlation method can reveal associations between activation in face-selective brain regions and neural processes at 170ms associated with face perception.

Fusing concurrent EEG-fMRI with dynamic causal modeling: application to effective connectivity during face perception

Despite the wealth of research on face perception, the interactions between core regions in the face-sensitive network of the visual cortex are not well understood. In particular, the link between neural activity in face-sensitive brain regions measured by fMRI and EEG markers of face-selective processing in the N170 component is not well established. In this study, we used dynamic causal modeling (DCM) as a data fusion approach to integrate concurrently acquired EEG and fMRI data during the perception of upright compared with inverted faces. Data features derived from single-trial EEG variability were used as contextual modulators on fMRI-derived estimates of effective connectivity between key regions of the face perception network. The overall construction of our model space was highly constrained by the effects of task and ERP parameters on our fMRI data. Bayesian model selection suggested that the occipital face area (OFA) acted as a central gatekeeper directing visual information to the superior temporal sulcus (STS), the fusiform face area (FFA), and to a medial region of the fusiform gyrus (mFG). The connection from the OFA to the STS was strengthened on trials in which N170 amplitudes to upright faces were large. In contrast, the connection from the OFA to the mFG, an area known to be involved in object processing, was enhanced for inverted faces particularly on trials in which N170 amplitudes were small. Our results suggest that trial-by-trial variation in neural activity at around 170 ms, reflected in the N170 component, reflects the relative engagement of the OFA to STS/FFA network over the OFA to mFG object processing network for face perception. Importantly, the DCMs predicted the observed data significantly better by including the modulators derived from the N170, highlighting the value of incorporating EEG-derived information to explain interactions between regions as a multi-modal data fusion method for combined EEG-fMRI.

Measurement of numicro and nue events in an off-axis horn-focused neutrino beam

We report the first observation of off-axis neutrino interactions in the MiniBooNE detector from the NuMI beam line at Fermilab. The MiniBooNE detector is located 745 m from the NuMI production target, at 110 mrad angle (6.3 degrees) with respect to the NuMI beam axis. Samples of charged-current quasielastic numicro and nue interactions are analyzed and found to be in agreement with expectation. This provides a direct verification of the expected pion and kaon contributions to the neutrino flux and validates the modeling of the NuMI off-axis beam.

Unexplained excess of electronlike events from a 1-GeV neutrino beam

The MiniBooNE Collaboration observes unexplained electronlike events in the reconstructed neutrino energy range from 200 to 475 MeV. With 6.46x10;{20} protons on target, 544 electronlike events are observed in this energy range, compared to an expectation of 415.2+/-43.4 events, corresponding to an excess of 128.8+/-20.4+/-38.3 events. The shape of the excess in several kinematic variables is consistent with being due to either nu_{e} and nu[over ]_{e} charged-current scattering or nu_{mu} neutral-current scattering with a photon in the final state. No significant excess of events is observed in the reconstructed neutrino energy range from 475 to 1250 MeV, where 408 events are observed compared to an expectation of 385.9+/-35.7 events.

Klippel-Feil syndrome and supra-aortic arch anomaly: a case report

Patients with Klippel-Feil syndrome have an increased incidence of supra-aortic arch anomalies. The present report presents the case of a patient who, during evaluation of his carotid arteries for nonspecific symptoms, was found to have an anomaly of the supra-aortic branches and Klippel-Feil syndrome.

Stage-specific effects of the osmolarity of a culture medium on the development of parthenogenetic diploids in the pig

The objective of this study was to investigate the effects of osmolarity of culture media on the development of porcine parthenogenetic diploids. Oocyte-cumulus-granulosa cell complexes were collected from ovaries and then in vitro-cultured for 48 h. The mature oocytes were subjected to a single electro-stimulation (El-St; 100 micros, 1500 V/cm), treated with 5.0 microg/ml Cytochalasin B for 4h and then cultured under various conditions as described below. In Experiment 1, the diploids were cultured for 168 h after El-St in modified Whitten's medium with 256 mOsmol (mWM256), mKRB with 309 mOsmol, and mWM with 309 mOsmol (mWM309), in which the osmolarity was adjusted by addition of NaCl or mannitol, or by reduction of distilled water. In Experiment 2, the diploids were cultured in the five media used in Experiment 1 for the first 48 h, and then in mWM256 until 168 h after El-St. In Experiment 3, the diploids were cultured for the first 48 h in mWM with osmolarity adjusted from 256 to 330 mOsmol by addition of NaCl for the first 48 h and then in mWM256 until 168 h after El-St. In Experiment 4, the diploids were cultured in mWM with 290 mOsmol (mWM290) for the first period of 24, 48, or 72 h, and then in mWM256 until 168 h after El-St. In Experiment 5, after diploids were cultured in mWM290 for the first 48 h, the obtained 4-cell diploids were transferred to mWM with osmolarity adjusted from 200 to 310 mOsmol by addition of NaCl, then cultured until 168 h after El-St. All media were supplemented with 0.5mg/ml hyaluronic acid and 4.0mg/ml bovine serum albumin. The results obtained in Experiments 1-5 indicate that the osmolarity of a medium, but not the Na(+)/K(+) ratio, exerts effects on the development of diploids to the blastocyst stage. The change of osmolarity of the culture media after the 4-cell stage increased the rate of expanded blastocyst formation in porcine diploids. The optimal osmolarities of culture medium for the first 48 h after El-St (before the 4-cell stage) were 290 and 280-320 mOsmol, and those for the later period (after the 4-cell stage) were 256 and 220-270 mOsmol, respectively.

Mapping of genes controlling aluminum tolerance in rice: comparison of different genetic backgrounds

Aluminum toxicity is the main factor limiting the productivity of crop plants in acid soils, particularly in the tropics and subtropics. In this study, a doubled-haploid population derived from the rice ( Oryza sativa L.) breeding lines CT9993 and IR62266 was used to map genes controlling Al tolerance. A genetic linkage map consisting of 280 DNA markers (RFLP, AFLP and SSR) was constructed to determine the position and nature of quantitative trait loci (QTLs) affecting Al tolerance. Three characters - control root length (CRL), Al-stressed root length (SRL) and root length ratio (RR) - were evaluated for the DH lines and the parents at the seedling stage in nutrient solution. A total of 20 QTLs controlling root growth under Al stress and control conditions were detected and distributed over 10 of the 12 rice chromosomes, reflecting multigenic control of these traits. The two QTLs of largest effect, qALRR-1-1 and qALRR-8 for root length ratio (a measurement of Al tolerance) were localized on chromosomes 1 and 8, respectively. Three other QTLs in addition to qALRR-8 were apparently unique in the CT9993 x IR62266 mapping population, which may explain the high level of Al tolerance in CT9993. Comparative mapping identified a conserved genomic region on chromosome 1 associated with Al tolerance across three rice genetic backgrounds. This region provides an important starting point for isolating genes responsible for different mechanisms of aluminum tolerance and understanding the genetic nature of this trait in rice and other cereals.

Truncated equine LH beta and asparagine(56)-deglycosylated equine LH alpha combine to produce a potent FSH antagonist

Hybrid hormone preparations were prepared by combining intact and Asn(56)-deglycosylated (N(56)dg) equine (e) LH or FSH alpha subunit preparations with truncated, des(121-149)eLH beta (eLH beta t), immunopurified, intact eLH beta or equine chorionic gonadotropin beta (eCG beta) preparations, and eFSH beta. The LH receptor-binding potencies of N(56)dg-eLH alpha:eLH beta t and N(56)dg-eFSH alpha:eLH beta t hybrids were equivalent to that of eLH; however, both N(56)dg-alpha preparations were only 3-4% as active as eLH in the rat testis Leydig cell bioassay. In the granulosa cell FSH bioassay, eLH alpha:eLH beta t stimulated progesterone synthesis and induced aromatase activity, while N(56)dg-eLH alpha:eLH beta t was completely inactive at doses up to 5 microg. N(56)dg-eLH alpha:eLH beta t inhibited progesterone production and aromatase induction elicited by 0.3 ng eFSH or 2 ng human (h) FSH. The inhibitory activities of N(56)dg-eLH alpha:eLH beta and N(56)dg-eCG alpha:eLH beta t were only 10% that of N(56)dg-eLH alpha:eLH beta t. N(56)dg-eLH alpha:eCG beta did not inhibit progesterone synthesis stimulated by eFSH at all and appeared to further stimulate aromatase induction at the highest dose tested. Preincubation of N(56)dg-eLH alpha:eLH beta and N(56)dg-eLH alpha:eLH beta t for 72 h at 37 C resulted in no loss of FSH receptor-binding activity. Preincubation resulted in 50% loss of receptor-binding activity by the eFSH preparation due to subunit dissociation, while 88% of N(56)dg-eLH alpha:eFSH beta activity was lost following 72 h, 37 C preincubation. While alpha Asn(56) oligosaccharide had no effect on eLH beta hybrid stability, it did contribute to the stability of the eFSH heterodimer.

A receptor-mediated mechanism of nicotine toxicity in oral keratinocytes

Smoking and smokeless tobacco cause morbidity that originates from the epithelium lining of the skin and upper digestive tract. Oral keratinocytes (OKC) express nicotinic acetylcholine receptors (nAChRs) that bind nicotine (Nic). We studied the mechanism of the receptor-mediated toxicity of tobacco products on OKC. Preincubation of normal human OKC with Nic altered the ligand-binding kinetics of their nAChRs, suggesting that the nAChRs underwent structural changes. This hypothesis was confirmed by the finding that exposure of OKC to Nic causes transcriptional and translational changes. Through RT-PCR and immunoblotting, we found a 1.5- to 2.9-fold increase in the mRNA and protein levels of alpha3, alpha5, alpha7, beta2, and beta4 nAChR subunits. Exposure of OKC to Nic also changed the mRNA and protein levels of the cell cycle and cell differentiation markers Ki-67, PCNA, p21, cyclin D1, p53, filaggrin, loricrin, and cytokeratins 1 and 10. The nicotinic antagonist mecamylamine prevented these changes, which indicates that the Nic-induced changes in the expression of both the nAChR and the cell cycle and cell differentiation genes resulted from pharmacologic stimulation of nAChRs with Nic. To establish the relevance of these findings to the pathobiologic effects of tobacco products in vivo, we studied the above parameters in the oral tissue of rats and mice after their exposure for 3 weeks to environmental cigarette smoke or drinking water containing equivalent concentrations of Nic that are pathophysiologically relevant. The changes of the nAChRs and the cell cycle and cell differentiation genes were similar to those found in vitro. The results of indirect immunofluorescence assay of tissue specimens validated these findings. Thus, some pathobiologic effects of tobacco products in oral tissues may stem from Nic-induced alterations of the structure and function of keratinocyte nAChRs responsible for the physiologic regulation of the cell cycle by the cytotransmitter acetylcholine.

7SK small nuclear RNA binds to and inhibits the activity of CDK9/cyclin T complexes

The transcription of eukaryotic protein-coding genes involves complex regulation of RNA polymerase (Pol) II activity in response to physiological conditions and developmental cues. One element of this regulation involves phosphorylation of the carboxy-terminal domain (CTD) of the largest polymerase subunit by a transcription elongation factor, P-TEFb, which comprises the kinase CDK9 and cyclin T1 or T2 (ref. 1). Here we report that in human HeLa cells more than half of the P-TEFb is sequestered in larger complexes that also contain 7SK RNA, an abundant, small nuclear RNA (snRNA) of hitherto unknown function. P-TEFb and 7SK associate in a specific and reversible manner. In contrast to the smaller P-TEFb complexes, which have a high kinase activity, the larger 7SK/P-TEFb complexes show very weak kinase activity. Inhibition of cellular transcription by chemical agents or ultraviolet irradiation trigger the complete disruption of the P-TEFb/7SK complex, and enhance CDK9 activity. The transcription-dependent interaction of P-TEFb with 7SK may therefore contribute to an important feedback loop modulating the activity of RNA Pol II.

Chronic stavudine exposure induces hepatic mitochondrial toxicity in adult Erythrocebus patas monkeys

OBJECTIVES

To understand the mitochondrial mechanisms underlying the lactic acidosis and hepatic steatosis seen in some HIV-1-infected individuals after long-term stavudine (d4T) exposure, we have explored mitochondrial integrity in adult monkeys (Erythrocebus patas) given a daily human equivalent dose of d4T for 78 days.

STUDY DESIGN/METHODS

Three Erythrocebus patas (patas) monkeys were given 3 mg d4T orally twice daily (total 6 mg d4T), or approximately 1.2 mg d4T/kg body weight per day, for 78 days and compared with 3 unexposed animals. Blood taken from controls and from treated monkeys before and after drug exposure was subjected to a complete clinical chemistry profile. Liver and skeletal muscles were examined for oxidative phosphorylation enzyme specific activities, mitochondrial deoxyribonucleic acid (mtDNA) quantity by slot blot, and mtDNA integrity by Southern blot.

RESULTS

Clinical chemistry assays demonstrated few significant differences; however, one d4T-exposed monkey had a serum lactate of 8.1 mmol/L after 78 days of oral d4T ingestion. Specific activities of oxidative phosphorylation Complexes I, II, and IV were significantly altered in both livers and skeletal muscles from the d4T-exposed animals, compared with the controls (p < or = 0.05). Significant depletion of mitochondrial DNA was observed in livers of drug-exposed monkeys, but not in skeletal muscle (p < or = 0.05). Further examination of liver DNA by Southern blot confirmed hepatic mtDNA depletion in drug exposed animals.

CONCLUSIONS

The data suggest that direct examination of the liver may be required to elucidate clinical d4T-induced hepatotoxicity related to mitochondrial damage.

Immunological aspects of microglia: relevance to Alzheimer's disease

Alzheimer's disease (AD) is a progressive dementing neurologic illness, and the most frequent cause of dementia in the elderly. Neuritic plaques are one of the main neuropathological findings in AD, and the major protein component is the beta-amyloid protein (A beta). Another striking feature of neuritic plaques is the presence of activated microglia, cytokines, and complement components, suggestive of "inflammatory foci" within AD brain. In this review, we will examine the mechanisms by which microglia become activated in AD, emphasizing the role in the A beta protein and proinflammatory cytokines. As well, pathways for suppression of microglial activation by immunosuppressive cytokines will be described. Inflammation mediated by activated microglia is an important component of AD pathophysiology, and strategies to control this response could provide new therapeutic approaches for the treatment of AD.

Esophageal cancer prevention in zinc-deficient rats: rapid induction of apoptosis by replenishing zinc

BACKGROUND

Nutritional zinc deficiency in rats increases esophageal cell proliferation and the incidence of N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumors. Replenishing zinc with a zinc-sufficient diet reduces these effects in zinc-deficient (ZD) rats. We investigated whether apoptosis was involved in the reduction of NMBA-induced esophageal tumors when ZD rats consumed a zinc-sufficient diet.

METHODS

Weanling rats were fed a ZD diet (zinc at 3-4 ppm) for 5 weeks to establish esophageal cell proliferation, then treated once with NMBA (2 mg/kg body weight), and divided into the following five groups (47-100 per group). One ZD group was fed the ZD diet, and four zinc-replenished (ZR) groups, ZR(1), ZR(24), ZR(72), and ZR(432), were fed a zinc-sufficient diet (zinc at 74-75 ppm) beginning 1, 24, 72, and 432 hours, respectively, after NMBA treatment. From 24 hours to 2 weeks after beginning a zinc-sufficient diet, esophagi from all ZR groups were analyzed for apoptosis and cell proliferation; ZD esophagi were the controls. Tumor incidence was determined 15 weeks after zinc replenishment. All statistical tests were two-sided.

RESULTS

Zinc replenishment initiated shortly after NMBA treatment effectively reduced esophageal tumorigenesis; 8% (three of 37) of ZR(1), 14% (five of 37) of ZR(24), 19% (five of 26) of ZR(72), and 48% (19 of 40) of ZR(432) rats developed esophageal tumors compared with 93% (14 of 15) of ZD animals (all P<.001). Importantly, 24 and 30 hours after zinc replenishment, esophagi had numerous apoptotic cells (% apoptotic cells: 0 hour = 2.9%, 95% confidence interval [CI] = 2.5% to 3.3%; 24 hours = 9.4%, 95% CI = 8.2% to 10.6%), and the expression of the proapoptotic Bax protein doubled. Within 48 hours, the ZR(1) epithelium was three to five cell layers thick compared with 10-20 layers before zinc replenishment.

CONCLUSIONS

Zinc replenishment of NMBA-treated ZD rats rapidly induces apoptosis in esophageal epithelial cells and thereby substantially reduces the development of esophageal cancer.

Characterization of human FSH isoforms reveals a nonglycosylated beta-subunit in addition to the conventional glycosylated beta-subunit

Human FSH consists of a mixture of isoforms that can be separated on the basis of differences in negative charge conferred by variations in the numbers of sialic acid residues that terminate oligosaccharide branches. Western analysis of human FSH isoforms separated by chromatofocusing revealed the presence of two human FSHbeta isoforms that differed in size. A low mol wt human FSHbeta isoform was associated with all FSH isoform fractions. A high mol wt human FSHbeta isoform was associated with the more acidic fractions and increased in relative abundance as the pI decreased. Characterization of representative human FSHbeta isoforms by mass spectrometry and automated Edman degradation revealed a low mol wt isoform that was not glycosylated. A high mol wt isoform was N-glycosylated at Asn residues 7 and 24. These results indicate that pituitary human FSH consists of two classes of molecules: those that possess a nonglycosylated beta-subunit and those that possess a glycosylated beta-subunit. Glycoprotein hormones are known to be elliptical molecules, and the beta-subunit oligosaccharides project outward from the short diameter, thereby increasing it. It is interesting to speculate that this change in shape might affect ultrafiltration rates, leading to differences in delivery rates to target tissues and elimination by filtration in the kidney.