α1-COP modulates plasmodesmata function through sphingolipid enzyme regulation.

Callose, a β-1,3-glucan plant cell wall polymer, regulates symplasmic channel size at plasmodesmata (PD) and plays a crucial role in a variety of plant processes. However, elucidating the molecular mechanism of PD callose homeostasis is limited. We screened and identified an Arabidopsis mutant plant with excessive callose deposition at PD and found that the mutated gene was α1-COP, a member of the coat protein I (COPI) coatomer complex.

The processed C-terminus of AvrRps4 effector suppresses plant immunity via targeting multiple WRKYs.

Pathogens generate and secrete effector proteins to the host plant cells during pathogenesis to promote virulence and colonization. If the plant carries resistance (R) proteins that recognize pathogen effectors, effector-triggered immunity (ETI) is activated, resulting in a robust immune response and hypersensitive response (HR). The bipartite effector AvrRps4 from Pseudomonas syringae pv.

Engineering plant immune circuit: walking to the bright future with a novel toolbox.

Plant pathogens destroy crops and cause severe yield losses, leading to an insufficient food supply to sustain the human population. Apart from relying on natural plant immune systems to combat biological agents or waiting for the appropriate evolutionary steps to occur over time, researchers are currently seeking new breakthrough methods to boost disease resistance in plants through genetic engineering. Here, we summarize the past two decades of research in disease resistance engineering against an assortment of pathogens through modifying the plant immune components (internal and external) with several biotechnological techniques.

Pathogen effectors: What do they do at plasmodesmata?

Plants perceive an assortment of external cues during their life cycle, including abiotic and biotic stressors. Biotic stress from a variety of pathogens, including viruses, oomycetes, fungi, and bacteria, is considered to be a substantial factor hindering plant growth and development. To hijack the host cell's defence machinery, plant pathogens have evolved sophisticated attack strategies mediated by numerous effector proteins.

Nuclear Localization of HopA1 Is Required for Effector-Triggered Immunity.

Plant resistance proteins recognize cognate pathogen avirulence proteins (also named effectors) to implement the innate immune responses called effector-triggered immunity. Previously, we reported that from pv. strain 61 was identified as an gene for .

Near-IR and CP-OCT imaging of suspected occlusal caries lesions.

Introduction: Radiographic methods have poor sensitivity for occlusal lesions and by the time the lesions are radiolucent they have typically progressed deep into the dentin. New more sensitive imaging methods are needed to detect occlusal lesions. In this study, cross-polarization optical coherence tomography (CP-OCT) and near-IR imaging were used to image questionable occlusal lesions (QOC's) that were not visible on radiographs but had been scheduled for restoration on 30 test subjects.

Enamel Thickness Determination by Optical Coherence Tomography: In vitro Validation.

Optical coherence tomography (OCT) has been introduced in dentistry as a nondestructive diagnostic imaging tool that does not utilize ionizing radiation. This study investigated the agreement between polarization-sensitive OCT (PS-OCT), microcomputed tomography (μ-CT), and histology for enamel thickness measurements. Human enamel samples were prepared and evaluated with μ-CT and PS-OCT and then sectioned and observed via digital transversal light microscopy.

Use of an optical clearing agent to enhance the visibility of subsurface structures and lesions from tooth occlusal surfaces.

The purpose of this study is to show that optical clearing agents can be used to increase the visibility of deeply penetrating occlusal lesions that have reached the underlying dentin and spread laterally under the enamel. Previous studies have shown that high refractive index fluids can increase the contrast of caries lesions. Extracted teeth with natural occlusal lesions were imaged with optical coherence tomography (OCT) with and without the addition of a transparent vinyl polysiloxane impression material (VPS) currently used in vivo.

Enhancement of OCT images with vinyl polysiloxane (VPS).

Several studies have shown that optical coherence tomography (OCT) can be used to measure the remaining enamel thickness and detect the location of subsurface lesions hidden under the sound enamel. Moreover studies have shown that high refractive index liquids can be used to improve the visibility of subsurface lesions in OCT images. In this study, we demonstrate that vinyl polysiloxane (VPS) impression materials which are routinely used in dentistry can be used to enhance the detection of dentinal lesions on tooth occlusal surfaces.

Clinical monitoring of smooth surface enamel lesions using CP-OCT during nonsurgical intervention.

Introduction: Studies have shown that cross-polarization optical coherence tomography (CP-OCT) can be used to image the internal structure of carious lesions in vivo. The objective of this study was to show that CP-OCT can be used to monitor changes in the internal structure of early active carious lesions on smooth surfaces during non-surgical intervention with fluoride.

Methods: Lesions on the smooth surfaces of teeth were imaged using CP-OCT on 17 test subjects.

Enhanced detection of dentinal lesions in OCT images using the RKT transformation.

Several studies have shown that optical coherence tomography (OCT) can be used to measure the remaining enamel thickness and detect the location of subsurface lesions hidden under the sound enamel. The purpose of this study was to develop algorithms to enhance the visibility of subsurface structures such as hidden occlusal lesions and the dentinal-enamel junction. Extracted teeth with natural occlusal lesions were imaged with OCT with and without added high index fluids.

Automated assessment of the remineralization of artificial enamel lesions with polarization-sensitive optical coherence tomography.

Accurate measurement of the highly mineralized transparent surface layer that forms on caries lesions is important for diagnosis of the lesion activity because chemical intervention can slow or reverse the caries process via remineralization. Previous in-vitro and in-vivo studies have demonstrated that polarization-sensitive optical coherence tomography (PS-OCT) can nondestructively image the subsurface lesion structure and the highly mineralized transparent surface zone of caries lesions. The purpose of this study was to develop an approach to automatically process 3-dimensional PS-OCT images and to accurately assess the remineralization process in simulated enamel lesions.

Enhancing the detection of hidden occlusal caries lesions with OCT using high index liquids.

In a previous study, we investigated the influence of several high refractive index fluids on the performance of polarization sensitive optical coherence tomography (PS-OCT). That study showed that these liquids can increase the effective imaging depth and lesion contrast. Other and studies have shown that OCT can be used to show whether occlusal lesions have penetrated to the dentinal-enamel junction (DEJ) and spread laterally under the enamel.

Longitudinal monitoring of demineralization peripheral to orthodontic brackets using cross polarization optical coherence tomography.

Objectives: The aim of this study was to test the hypothesis that cross-polarization optical coherence tomography (CP-OCT) can be used to longitudinally monitor demineralization peripheral to orthodontic brackets in an extended clinical study.

Methods: A high-speed CP-OCT system was used to acquire 3D volumetric images of the area at the base of orthodontic brackets over a period of 12 months after placement. The reflectivity was measured at 3-month intervals for 12 months to determine if there was increased demineralization.

Monitoring the Remineralization of Early Simulated Lesions using a pH Cycling Model with CP-OCT.

If caries lesions are detected early enough they can be arrested by chemical intervention and dietary changes without the need for chemical intervention. Optical coherence tomography is ideally suited to monitor the changes that occur in caries lesions as a result of nonsurgical intervention, since OCT can nondestructively image the internal structure of the lesion. One of the most important changes that occurs in a lesion is preferential deposition of mineral in the outer surface zone.

The valosin-containing protein promotes cardiac survival through the inducible isoform of nitric oxide synthase.

Aims: Expression of the heat shock protein 22 (Hsp22) in the heart stimulates cardiac cell survival through activation of the Akt pathway and expression of the inducible nitric oxide (NO) synthase (iNOS), the mediator of ischaemic preconditioning and the most powerful prophylaxis against cardiac cell death. The goal of the present study was to elucidate the downstream effector by which Hsp22 and Akt increase iNOS expression. We tested both in vivo and in vitro the hypothesis that such an effector is the valosin-containing protein (VCP), an Akt substrate, which activates the transcription factor NF-κB, using a transgenic mouse with cardiac-specific over-expression of Hsp22, as well as isolated rat cardiac myocytes.

Investigation of Acid-Etched CO Laser Ablated Enamel Surfaces Using Polarization Sensitive Optical Coherence Tomography.

A carbon dioxide laser operating at the highly absorbed wavelength of 9.3μm with a pulse duration of 10-15μs is ideally suited for caries removal and caries prevention. The enamel thermally modified by the laser has enhanced resistance to acid dissolution.

Nondestructive Monitoring of the Repair of Natural Occlusal Lesions using Cross - Polarization Optical Coherence Tomography.

Previous remineralization studies employing cross polarization sensitive optical coherence tomography (CP-OCT), have been limited to the repair of artificial enamel-like lesions. In this study we attempted to remineralize existing occlusal lesions on extracted teeth. Lesions were imaged before and after exposure to an acidic remineralization regimen and the integrated reflectivity and lesion depth was calculated.

Monitoring tooth demineralization using a cross polarization optical coherence tomographic system with an integrated MEMS scanner.

New methods are needed for the nondestructive measurement of tooth demineralization and remineralization to monitor the progression of incipient caries lesions (tooth decay) for effective nonsurgical intervention and to evaluate the performance of anti-caries treatments such as chemical treatments or laser irradiation. Studies have shown that optical coherence tomography (OCT) has great potential to fulfill this role since it can be used to measure the depth and severity of early lesions with an axial resolution exceeding 10-µm, it is easy to apply and it can be used to image the convoluted topography of tooth occlusal surfaces. In this paper we present early results using a new cross-polarization OCT system introduced by Santec.

Remineralization of Root Caries Monitored Using Cross-Polarization Optical Coherence Tomography.

Previous studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to image caries lesions in dentin, measure nondestructively the severity of dentin demineralization, and determine the efficacy of intervention with anticaries agents including fluoride and lasers. However, those studies were limited to artificial lesions on dentin and roots surfaces. The objective of this study is to determine if a cross polarization OCT system (CP-OCT) can be used to nondestructively measure a reduction in the reflectivity of natural root caries lesions after exposure to a remineralization solution.

Nondestructive monitoring of the repair of enamel artificial lesions by an acidic remineralization model using polarization-sensitive optical coherence tomography.

Objectives: It is difficult to completely remineralize carious lesions because diffusion into the interior of the lesion is inhibited as new mineral is deposited in the outermost layers. In previous remineralization studies employing polarization sensitive optical coherence tomography (PS-OCT), two models of remineralization were employed and in both models there was preferential deposition of mineral in the outer most layer. In this study we attempted to remineralize the entire lesion using an acidic remineralization model and demonstrate that this remineralization can be monitored using PS-OCT.

Non-destructive clinical assessment of occlusal caries lesions using near-IR imaging methods.

Objective: Enamel is highly transparent in the near-IR (NIR) at wavelengths near 1,300 nm, and stains are not visible. The purpose of this study was to use NIR transillumination and optical coherence tomography (OCT) to estimate the severity of caries lesions on occlusal surfaces both in vivo and on extracted teeth.

Methods: Extracted molars with suspected occlusal lesions were examined with OCT and polarization sensitive OCT (PS-OCT), and subsequently sectioned and examined with polarized light microscopy (PLM) and transverse microradiography (TMR).

Repair of Artificial Lesions using an Acidic Remineralization Model Monitored with Cross - Polarization Optical Coherence Tomography.

It is difficult to completely remineralize carious lesions because diffusion into the interior of the lesion is inhibited as new mineral is deposited in the outermost layers. In previous remineralization studies employing polarization sensitive optical coherence tomography (PS-OCT), two models of remineralization were employed and in both models there was preferential deposition of mineral in the outer most layer. In this study we attempted to remineralize the entire lesion using an acidic remineralization model and demonstrate that this remineralization can be monitored using PS-OCT.

In vivo Near-IR Imaging of Occlusal Lesions at 1310-nm.

Several in vitro studies have demonstrated the potential for transillumination imaging and optical coherence tomography operating at 1310-nm for imaging caries lesions on tooth proximal and occlusal surfaces. Recently, we demonstrated that lesions on proximal surfaces could be imaged in vivo using NIR transillumination and that PS-OCT can be used in vivo to measure early demineralization on tooth buccal and occlusal surfaces. In this paper we report the first in vivo measurements using OCT and NIR imaging of occlusal lesions that have been scheduled for restoration.

Nondestructive Assessment of Early Tooth Demineralization Using Cross-Polarization Optical Coherence Tomography.

New methods are needed for the nondestructive measurement of tooth demineralization and remineralization to monitor the progression of incipient caries lesions (tooth decay) for effective nonsurgical intervention and to evaluate the performance of anticaries treatments such as chemical treatments or laser irradiation. Studies have shown that optical coherence tomography (OCT) has great potential to fulfill this role since it can be used to measure the depth and severity of early lesions with an axial resolution exceeding 10 µm, it is easy to apply in vivo and it can be used to image the convoluted topography of tooth occlusal surfaces. In this paper, a review of the use of polarization-sensitive-OCT for the measurement of tooth demineralization is provided along with some recent results regarding improved methods for the detection of caries lesions in the earliest stages of development.