Complex genetic, photothermal, and photoacoustic analysis of nanoparticle-plant interactions

Understanding the nature of interactions between engineered nanomaterials and plants is crucial in comprehending the impact of nanotechnology on the environment and agriculture with a focus on toxicity concerns, plant disease treatment, and genetic engineering. To date, little progress has been made in studying nanoparticle-plant interactions at single nanoparticle and genetic levels. Here, we introduce an advanced platform integrating genetic, Raman, photothermal, and photoacoustic methods. Using this approach, we discovered that multiwall carbon nanotubes induce previously unknown changes in gene expression in tomato leaves and roots, particularly, up-regulation of the stress-related genes, including those induced by pathogens and the water-channel LeAqp2 gene. A nano-bubble amplified photothermal/photoacoustic imaging, spectroscopy, and burning technique demonstrated the detection of multiwall carbon nanotubes in roots, leaves, and fruits down to the single nanoparticle and cell level. Thus, our integrated platform allows the study of nanoparticles' impact on plants with higher sensitivity and specificity, compared to existing assays.     

Customized Planning of Augmentation Mammaplasty with Silicon Implants Using Three-Dimensional Optical Body Scans and Biomechanical Modeling of Soft Tissue Outcome

The aesthetic results of augmentation mammaplasty are essentially determined by the size and the shape of the implant as well as its position on the chest. To achieve successful aesthetic results, customized surgery planning based on a reliable visual concept of the prospective surgery outcome and quantitative methods for assessment of three-dimensional (3D) breast shape could be of considerable additional value. This report evaluates a novel method for customized planning and quantitative optimization of breast augmentation based on 3D optical body scanning of the patient’s breast and computational modeling of soft tissue mechanics. This method allows a 3D photo-realistic appearance of postsurgery breasts to be simulated for different surgical scenarios. It also allows the result of a virtual simulation to be implemented using measurements derived from a computationally predicted breast model. A series of clinical studies are presented that demonstrate the feasibility and accuracy of the proposed approach for customized 3D planning of breast augmentation, including direct comparison between simulated and postsurgery results. Our experimental results show that for 89% of the breast surface, the average difference between the simulated and postsurgery breast models amounts to less than 1 mm. The presented method for customized planning of augmentation mammaplasty enables realistic prediction and quantitative optimization of postsurgery breast appearance. Based on individual 3D data and physical modeling, the described approach enables more accurate and reliable predictions of surgery outcomes than conventionally used photos of prior patients, drawings, or ad hoc data manipulation. Moreover, it provides precise quantitative data for bridging the gap between virtual simulation and real surgery.     

Ablation of paroxysmal and persistent atrial fibrillation: 1-year follow-up through continuous subcutaneous monitoring

Ablation of Paroxysmal and Persistent Atrial Fibrillation . Background: The aim of this prospective observational study was to identify responders to ablation through continuous subcutaneous monitoring for 1 year after ablation in patients with paroxysmal atrial fibrillation (PAF) or persistent AF (PersAF). Method: Patients with symptomatic drug refractory AF were enrolled. Real‐time three‐dimensional (3D) left atrium maps were reconstructed by using a nonfluoroscopic navigation system (CARTO, Biosense‐Webster Inc., Diamond Bar, CA, USA). The ipsilateral left and right pulmonary veins (PVs) were encircled in 1 lesion line by circumferential PV isolation. All patients were implanted with Reveal XT (Medtronic Inc.) for continuous AF monitoring and data collected every month during the 12‐month follow‐up. Results: We enrolled 129 patients (56 ± 9 years, 102 males), all of whom were followed‐up for 12 months after the last ablation procedure: 58 (45%) had a history of PersAF. After only 1 ablation procedure, 76 (59%) of the 129 patients were AF‐free at 12‐month: 48 out of 71 (68%) in the PAF group and 28 out of 58 (48%) in the PersAF group. After 1 or more ablation procedures, 94 (73%) of the 129 patients were AF‐free 12 months after the last procedure: 57 out of 71 (80%) in the PAF group and 37 out of 58 (64%) in the PersAF group. Conclusion: Ablation is highly effective in treating AF, as assessed through detailed 1‐year continuous monitoring: success rate is higher in PAF than in PersAF patients. The use of subcutaneous monitors is a valuable means of identifying responders and nonresponders, and can potentially guide antiarrhythmic and antithrombotic therapies. (J Cardiovasc Electrophysiol, Vol. 22, pp. 369‐375)     

Neurocognitive characterizations of Russian heroin addicts without a significant history of other drug use

Research on the neurocognitive characteristics of heroin addiction is sparse and studies that do exist include polydrug abusers; thus, they are unable to distinguish neurocognitive effects of heroin from those of other drugs. To identify neurocognitive correlates specific to heroin addiction, the present study was conducted in St. Petersburg, Russia where individuals typically abuse and/or become addicted to only one substance, generally alcohol or heroin. Heroin addicts were recruited from an inpatient treatment facility in St. Petersburg. Three comparison groups included alcoholics, addicts who used both alcohol and heroin, and non-abusers. Psychiatric, background, and drug history evaluations were administered after detoxification to screen for exclusion criteria and characterize the sample. Executive Cognitive Functions (ECF) that largely activate areas of the prefrontal cortex and its circuitry measured include complex visual pattern recognition (Paired Associates Learning), working memory (Delayed Matching to Sample), problem solving (Stockings of Cambridge), executive decision making (Cambridge Decision Making Task), cognitive flexibility (Stroop Color-Word Task) and response shifting (Stop Change Task). In many respects, the heroin addicts were similar to alcohol and alcohol+heroin dependent groups in neurocognitive deficits relative to controls. The primary finding was that heroin addicts exhibited significantly more disadvantageous decision making and longer deliberation times while making risky decisions than the other groups. Because the nature and degree of recovery from drug abuse are likely a function of the type or pattern of neurocognitive impairment, differential drug effects must be considered.     

Extracellular GC-rich DNA activates TLR9- and NF-kB-dependent signaling pathways in human adipose-derived mesenchymal stem cells (haMSCs)

INTRODUCTION: The content of GC-rich ribosomal repeats (rDNA) in cell-free DNA (cfDNA) of patients with various diseases is several times higher as compared with genomic DNA (gDNA) and cfDNA of healthy donors. rDNA may act as Toll-like receptor 9 (TLR9) ligands and affect human adipose-derived mesenchymal stem cells (haMSCs). Here we explore effects of human cfDNAs and model rDNA fragments on cultured haMSCs. AREAS COVERED: Both cfDNAs and cloned rDNA stimulate expression of TLR9 (qRT-PCR). Treatment with cloned rDNA leads to an increase in the number of TLR9(+) cells (FACS), expression levels for both TLR9 and Myd88, the translocation of nuclear factor-kappa B to the nuclei and up-regulation of TNFα and IL-10 cytokines (ELISA). As shown by an analysis of γH2AX-foci and MTT test, the preconditioning of haMSCs with cloned rDNA fragment increases the resistance of these cells to irradiation at 2Gy, while the treatments with control gDNA did not stimulate either TLR9- or NF-kB-dependent signaling pathways. EXPERT OPINION: GC-rich sequences present in cfDNA stimulate endogenous stems cells when body is exposed to adverse conditions. GC-rich fragments of human DNA may be used for preconditioning of therapeutic MSCs aiming at an increase in their survival in the ailing body.     

Norepinephrine enables the induction of associative long-term potentiation at thalamo-amygdala synapses

Emotional arousal, linked to a surge of norepinephrine (NE) in the amygdala, leads to creation of stronger and longer-lasting memories. However, little is known about the synaptic mechanisms of such modulatory NE influences. Long-term potentiation (LTP) in auditory inputs to the lateral nucleus of the amygdala was recently linked to the acquisition of fear memory. Therefore we explored whether LTP induction at thalamo-amygdala projections, conveying the acoustic conditioned stimulus information to the amygdala during fear conditioning, is under adrenergic control. Using whole-cell recordings from amygdala slices, we show that NE suppresses GABAergic inhibition of projection neurons in the lateral amygdala and enables the induction of LTP at thalamo-amygdala synapses under conditions of intact GABA(A) receptor-mediated inhibition. Our data indicate that the NE effects on the efficacy of inhibition could result from a decrease in excitability of local circuit interneurons, without direct effects of NE on release machinery of the GABA-containing vesicles or the size of single-quanta postsynaptic GABA(A) receptor-mediated responses. Thus, adrenergic modulation of local interneurons may contribute to the formation of fear memory by gating LTP in the conditioned stimulus pathways.