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The alveolar bone is a unique osseous tissue due to the presence of the teeth and the proximity of commensal oral microbes. Commensal microbe effects on alveolar bone homeostasis have been attributed to the oral microbiota, yet the impact of commensal gut microbes is unknown. Study purpose was to elucidate whether commensal gut microbes regulate osteoimmune mechanisms and skeletal homeostasis in alveolar bone. Male C57BL/6T germfree (GF) littermate mice were maintained as GF or monoassociated with segmented filamentous bacteria (SFB), a commensal gut bacterium. SFB has been shown to elicit broad immune response effects, including the induction of T(H)17/IL17A immunity, which impacts the development and homeostasis of host tissues. SFB colonized the gut, but not oral cavity, and increased IL17A levels in the ileum and serum. SFB had catabolic effects on alveolar bone and non-oral skeletal sites, which was attributed to enhanced osteoclastogenesis. The alveolar bone marrow of SFB vs. GF mice had increased dendritic cells, activated helper T-cells, T(H)1 cells, T(H)17 cells, and upregulated Tnf. Primary osteoblast cultures from SFB and GF mice were stimulated with vehicle-control, IL17A, or TNF to elucidate osteoblast-derived signaling factors contributing to the pro-osteoclastic phenotype in SFB mice. Treatment of RAW264.7 osteoclastic cells with supernatants from vehicle-stimulated SFB vs. GF osteoblasts recapitulated the osteoclast phenotype found in vivo. Supernatants from TNF-stimulated osteoblasts normalized RAW264.7 osteoclast endpoints across SFB and GF cultures, which was dependent on the induction of CXCL1 and CCL2. This report reveals that commensal gut microbes have the capacity to regulate osteoimmune processes in alveolar bone. Outcomes from this investigation challenge the current paradigm that alveolar bone health and homeostasis is strictly regulated by oral microbes.

Minimally invasive core needle biopsies for medical diagnoses have become increasingly common for many diseases. Although tissue cores can yield more diagnostic information than fine needle biopsies and cytologic evaluations, there is no rapid assessment at the point-of-care for intact tissue cores that is low-cost and non-destructive to the biopsy. We have developed a proof-of-concept 3D printed millifluidic histopathology lab-on-a-chip device to automatically handle, process, and image fresh core needle biopsies. This device, named CoreView, includes modules for biopsy removal from the acquisition tool, transport, staining and rinsing, imaging, segmentation, and multiplexed storage. Reliable removal from side-cutting needles and bidirectional fluid transport of core needle biopsies of five tissue types has been demonstrated with 0.5 mm positioning accuracy. Automation is aided by a MATLAB-based biopsy tracking algorithm that can detect the location of tissue and air bubbles in the channels of the millifluidic chip. With current and emerging optical imaging technologies, CoreView can be used for a rapid adequacy test at the point-of-care for tissue identification as well as glomeruli counting in renal core needle biopsies.

Periodontitis-mediated alveolar bone loss is caused by dysbiotic shifts in the commensal oral microbiota that upregulate proinflammatory osteoimmune responses. Study purpose was to determine whether antimicrobial-induced disruption of the commensal microbiota has deleterious effects on alveolar bone. We administered an antibiotic cocktail, minocycline, or vehicle-control to sex-matched C57BL/6T mice from age 6- to 12-weeks. Antibiotic cocktail and minocycline had catabolic effects on alveolar bone in specific-pathogen-free mice. We then administered minocycline or vehicle-control to male mice reared under specific-pathogen-free and germ-free conditions, and we subjected minocycline-treated specific-pathogen-free mice to chlorhexidine oral antiseptic rinses. Alveolar bone loss was greater in vehicle-treated specific-pathogen-free vs. germ-free mice, demonstrating that the commensal microbiota drives naturally occurring alveolar bone loss. Minocycline- vs. vehicle-treated germ-free mice had similar alveolar bone loss outcomes, implying that antimicrobial-driven alveolar bone loss is microbiota dependent. Minocycline induced phylum-level shifts in the oral bacteriome and exacerbated naturally occurring alveolar bone loss in specific-pathogen-free mice. Chlorhexidine further disrupted the oral bacteriome and worsened alveolar bone loss in minocycline-treated specific-pathogen-free mice, validating that antimicrobial-induced oral dysbiosis has deleterious effects on alveolar bone. Minocycline enhanced osteoclast size and interface with alveolar bone in specific-pathogen-free mice. Neutrophils and plasmacytoid dendritic cells were upregulated in cervical lymph nodes of minocycline-treated specific-pathogen-free mice. Paralleling the upregulated proinflammatory innate immune cells, minocycline therapy increased T(H)1 and T(H)17 cells that have known pro-osteoclastic actions in alveolar bone. This report reveals that antimicrobial perturbation of the commensal microbiota induces a proinflammatory oral dysbiotic state that exacerbates naturally occurring alveolar bone loss.

Minimally invasive core needle biopsies for medical diagnoses have become increasingly common for many diseases. Although tissue cores can yield more diagnostic information than fine needle biopsies and cytologic evaluation, there is no rapid evaluation at the point-of-care for intact tissue cores that is low-cost and non-destructive to the biopsy. We have developed a proof-of-concept 3D printed millifluidic histopathology lab-on-a-chip device to automatically handle, process, and image fresh core needle biopsies. This device, named CoreView, includes modules for biopsy removal from the acquisition tool, transport, staining and rinsing, imaging, segmentation, and multiplexed storage. Reliable removal from side-cutting needles and bidirectional fluid transport of core needle biopsies from five tissue types has been demonstrated with 0.5-mm positioning accuracy. Automation is aided by a MATLAB-based biopsy tracking algorithm that can detect the location of tissue and air bubbles in the channels of the millifluidic chip. With current and emerging optical imaging technologies, CoreView can be used for a rapid adequacy test at the point-of-care for tissue identification and glomeruli counting from renal core needle biopsies, and has the potential to be used for breast cancer diagnosis, phenotyping, and mapping of enriched tumorous regions for downstream analyses in global health applications.

Clinical detection of premalignant lesions often requires labeling with molecular probes. In the gastrointestinal tract, most cancers originate in epithelial layers which are interrogated using topically-applied probes with conjugated fluorescence dyes. As part of clinical trials using fluorescence peptide probes, we have developed two different instruments that rapidly image the biopsy at the bedside before fixation. These multimodal images (visible light reflectance and near infrared fluorescence) provide verification that the targeted lesion was sampled, and provide feedback to the clinician at the bedside for any follow-up procedure. Performance of these two prototypes are compared for fluorescence sensitivity and multimodal image quality.

Ventilator-associated pneumonia (VAP) is pneumonia that occurs >48hrs after initiation of mechanical ventilation and is a significant cause of morbidity and mortality in patients that are hospitalized in intensive care units (ICU). The risk of developing VAP increases during use, and a diagnosis of VAP has been associated with a substantial cost. There are up to hundreds of thousands of cases in the US per year, costing the healthcare system billions annually. Patients who suffer from VAP frequently require longer ICU stays, higher exposure to antibiotics, and more hospital care at the risk of increased mortality. The SARS-CoV-2 pandemic has further increased the use of antibiotics among patients with COVID19, an indicator of increased VAP prevalence. Before 2020, strides were made to reduce the incidence of VAP through hygienic protocols known as ‘VAP bundles.’ Despite the improvements, VAP continues to be a large problem, with the inoculation of pathogens within the endotracheal tube (ETT) itself. ETTs with built-in subglottic suction devices (SSDETT) allow the removal of subglottic secretions, but this has been adopted heterogeneously. We propose novel optical device designs to be used in combination with SSD-ETTs to reduce colonization and biofilm formation on the inner lumen of ETTs and reduce the incidence of VAP and improve patient care.

Measuring the activity of oral-bacteria in plaque, the sticky biofilm on enamel, can provide the presently lacking oral feedback to patients. We have developed O-pH, optical pH monitor that measures pH in the range of 4-7.5 and tested in vivo on 25 pediatric subjects (10-18 years) with high caries risk, 18 of these subjects had a dental cleaning within last two months and 7 didn’t have a cleaning in over 2 months. The average pH after a sugar rinse from regions of biofilm associated with caries was 5.8 and 0.5 units lower than the biofilm of sound enamel.

Clinical sampling of tissue that is read by a pathologist is currently the gold standard for making a disease diagnosis, but the few minimally invasive techniques available for small duct biopsies have low sensitivity, increasing the likelihood of false negative diagnoses. We propose a novel biopsy device designed to accurately sample tissue in a biliary stricture under fluoroscopy or endoscopic guidance. The device consists of thin blades organized around the circumference of a cylinder that are deployed into a cutting annulus capable of comprehensively sampling tissue from a stricture. A parametric study of the device performance was done using finite element analysis; this includes the blade deployment under combined axial compression and torsion followed by an axial ‘cutting’ step. The clinical feasibility of the device is determined by considering maximum deployment forces, the radial expansion achieved and the cutting stiffness. We find practical parameters for the device operation to be an overall length of 10 mm and a diameter of 3.5 mm for a \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$50~\mu \text{m}$ \end{document} blade thickness, which allow the device to be safely deployed with a force of 10N and achieve an expansion over 3x its original diameter. A model device was fabricated with these parameters and a \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$75~\mu \text{m}$ \end{document} thickness out of a NiTi superalloy and tested to validate the performance. The device showed strong agreement with an equivalent numerical model, reaching a peak force within 2% of that predicted numerically and fully recovering after compression to 20% of its length. Clinical and Translational Impact Statement–This pre-clinical research conceptually demonstrates a novel expandable device to biopsy tissue in narrow strictures during an ERCP procedure. It can greatly improve diagnostic tissue yield compared to existing methods.

Sugar-rich diets and poor dental hygiene promote the formation of a biofilm (plaque) that strongly adheres to the dental enamel surface and fosters the evolution of aciduric bacteria. The acid contributes to demineralization of the exterior tooth enamel, which accelerates after the pH drops below a critical value (∼5.5) for extended time periods resulting in the need for restorative procedures. Preventative techniques to alert the dentist and caries-susceptible patients regarding vulnerability to dental decay require a clinical measure of plaque activity. Therefore, there is a need to evaluate the acid production capability of plaque deposits in the pits and fissures of occlusal and interproximal regions. A ratiometric fluorescence pH-sensing device has been developed using an FDA-approved dye and LED excitation. Fluorescein spectral profiles were collected using a spectrometer and analyzed with a spectral unmixing algorithm for calibration over the pH range of 4.5 to 7. An in vivo pilot study on human subjects was performed using a sucrose rinse to accelerate bacterial metabolism and to measure the time-dependent drop in pH. The optical system is relatively immune to confounding factors such as photobleaching, dye concentration, and variation in excitation intensity associated with earlier dye-based pH measurement techniques.

Tooth decay is one of the most common chronic infectious diseases worldwide. Bacteria from the oral biofilm create a local acidic environment that demineralizes the enamel in the caries disease process. By optically imaging plaque pH in pits and fissures and contacting surfaces of teeth, then medicinal therapies can be accurately applied to prevent or monitor the reversal of caries. To achieve this goal, the fluorescence emission from an aqueous solution of sodium fluorescein was measured using a multimodal scanning fiber endoscope (mmSFE). The 1.6-millimeter diameter mmSFE scans 424nm laser light and collects wide-field reflectance for navigational purposes in grayscale at 30 Hz. Two fluorescence channels centered at 520 and 549 nm are acquired and ratiometric analysis produces a pseudo-color overlay of pH. In vitro measurements calibrate the pH heat maps in the range 4.7 to 7.2 pH (0.2 standard deviation). In vivo measurements of a single case study provides informative images of interproximal biofilm before and after a sugar rinse. Post processing a time series of images provides a method that calculates the average pH changes of oral biofilm, replicating the Stephan Curve. These spatio-temporal records of oral biofilm pH can provide a new method of assessing the risk of tooth decay, guide the application of preventative therapies, and provide a quantitative monitor of overall oral health. The non-contact in vivo optical imaging of pH may be extended to measurements of wound healing, tumor environment, and other food processing surfaces since it relies on low power laser light and a US FDA approved dye.

The commensal gut microbiota critically regulates immunomodulatory processes that influence normal skeletal growth and maturation. However, the influence of specific microbes on commensal gut microbiota osteoimmunoregulatory actions is unknown. We have shown previously that the commensal gut microbiota enhances TH17/IL17A immune response effects in marrow and liver that have procatabolic/antianabolic actions in the skeleton. Segmented filamentous bacteria (SFB), a specific commensal gut bacterium within phylum Firmicutes, potently induces TH17/IL17A‐mediated immunity. The study purpose was to delineate the influence of SFB on commensal gut microbiota immunomodulatory actions regulating normal postpubertal skeletal development. Two murine models were utilized: SFB‐monoassociated mice versus germ‐free (GF) mice and specific‐pathogen‐free (SPF) mice +/− SFB. SFB colonization was validated by 16S rDNA analysis, and SFB‐induced TH17/IL17A immunity was confirmed by upregulation of Il17a in ileum and IL17A in serum. SFB‐colonized mice had an osteopenic trabecular bone phenotype, which was attributed to SFB actions suppressing osteoblastogenesis and enhancing osteoclastogenesis. Intriguingly, SFB‐colonized mice had increased expression of proinflammatory chemokines and acute‐phase reactants in the liver. Lipocalin‐2 (LCN2), an acute‐phase reactant and antimicrobial peptide, was substantially elevated in the liver and serum of SFB‐colonized mice, which supports the notion that SFB regulation of commensal gut microbiota osteoimmunomodulatory actions are mediated in part through a gut–liver–bone axis. Proinflammatory TH17 and TH1 cells were increased in liver‐draining lymph nodes of SFB‐colonized mice, which further substantiates that SFB osteoimmune‐response effects may be mediated through the liver. SFB‐induction of Il17a in the gut and Lcn2 in the liver resulted in increased circulating levels of IL17A and LCN2. Recognizing that IL17A and LCN2 support osteoclastogenesis/suppress osteoblastogenesis, SFB actions impairing postpubertal skeletal development appear to be mediated through immunomodulatory effects in both the gut and liver. This research reveals that specific microbes critically impact commensal gut microbiota immunomodulatory actions regulating normal postpubertal skeletal growth and maturation. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

We have developed a new tool to measure the acid production by plaque oral bacteria. Many species of oral bacteria metabolize sugars in food and produce organic acids that demineralize the dental enamel leading to the formation of cavities. Measuring the acidity level before and after a sugar rinse can indicate the susceptibility of an individual to tooth decay and location of active caries. In a case study on two subjects, a non-contact optics-based pH device was able to track pH before and after a sugar rinse. The fiber optic probe measures acidity level in difficult to access dental locations such as occlusal pits and fissures based on changes in the spectral fluorescence profile of fluorescein (FL) dye. Fiber coupled 420 nm LED excites 200uM aqueous FL solution in the mouth. The fluorescence spectrum in 450-650 nm range is obtained using an adjacent fiber optic cable coupled to a spectrometer. Chemometric analysis of endmember dianion and anion species using least-square fitting is performed to determine the pH of the FL absorbed into the extracellular region of the oral biofilm. Other unwanted noise, like background light and auto-fluorescence in the range of 450-650 nm is removed before calculating biofilm pH. Using this device in a darkened room on two subjects, we were able to measure resting pH (before a sugar rinse) and track time dependent change in pH (after a sugar rinse) in the range of pH 4-7 paving the way for first clinical optical pH measurement in the mouth.

Multimodal endoscopy, with fluorescence labeled peptides specific for multiple biomarkers, is a promising technique to detect early-stage GI tract cancers in vivo. A reproducible bile duct phantom with near infrared (NIR) fluorescent targets is developed for practicing the clinical study protocol and quantitative evaluation of multimodal endoscope performance during biliary duct imaging. Furthermore, this phantom with strictures will be used for testing new fluorescence guided biopsy devices. Materials and Methods: A soft, flexible synthetic human bile duct was fabricated from a paintable silicone rubber. Due to the complex structure of biliary system (such as hepatic ducts, cystic duct, and common bile duct), the template mold for lumen was designed for 3D printing using Polyvinyl Acetate (PVA), which can be later dissolved in water. Cured gelatin patches with different concentrations of fluorescence dyes (Cy5 and IRDye800) were placed onto the mold. Then silicone rubber with pigments to simulate visual appearance was painted in layers. After the silicone curing, the phantom was placed in warm water (40 degreeC) to dissolve PVA. Two different multimodal scanning fiber endoscope systems, RGB reflectance + NIR fluorescence and 3 fluorescence (IRDye800, Cy5, and FITC) + grayscale reflectance, were used to test the phantom. Results: The bile duct phantom is flexible, stable, and repeatable to fabricate with strictures. Clinical study procedures of fluorescence labeling were evaluated quantitatively. The NIR fluorescence targets in the phantom were used to calibrate the imaging system, further develop image-based biomarker quantification.

Undetected caries can lead to painful cavities and surgical restorations. Lack of proper detection tools makes caries prevention dependent on dentist's expertise and presents obstacles in oral health monitoring. To overcome this problem, we have developed a new approach to predict early stages of enamel demineralization caused by oral bacteria. These bacteria metabolize sugars in our food and produce organic acids that lead to cavities. Measuring the acidity level can help predict early stages of tooth decay. pH paper or pH electrodes can be used to monitor acidity, but neither are able to track pH levels in all dental locations. Our device, DpOW, is a noncontact optics-based pH device that uses changes in the spectral fluorescence of FDA allowed fluorescein dye to measure acidity levels in difficult to access dental locations such as occlusal fissures. A prototype has been tested over a wide pH range (7.12 to 3.89) and shown to track the change in pH with 0.94 correlation coefficient.

We present a scanning fiber endoscope (SFE) designed for near-infrared (nir) imaging. The SFE piezo actuator drives a single mode fiber in spiral patterns; meanwhile return fibers collect the reflective light; then signals from detector are mapped onto an image according to the fiber scan trajectory. Many SFE prototypes have been developed based on red/green/blue reflectance, enhanced spectral, fluorescence, optical coherence, and multimodal imaging. These forward-view SFE prototypes have the advantage of miniature size (1-3mm), flexible shaft, video-speed frame rate (10-30Hz), wide field of view (60-100 degree) and good resolution quality. A new SFE prototype is being developed that operates entirely in near-infrared wavelength range, which is expected to have great potential in imaging dental lesions and monitoring therapy. The first nirSFE probe has a diameter of around 3mm, frame rate of 17Hz, 53 degree FOV and spatial resolution of 40um. Although the specific optical fibers made for nir makes the probe stiffer than previous prototypes, the flexible 2m shaft allows for easy orientation. Using this prototype we can achieve reflectance mode imaging and also switch between different wavelengths (1310nm, 1460nm, 1550nm) and light sources (SLD or laser). In the development of this prototype, we encounter several issues: 1) the speckle noise caused by interference of laser beams, 2) uneven illumination and reduced visual field caused by collection fiber distribution and numerical aperture, and 3) specular reflection patterns which can obscure important enamel target detail. We explore solutions to these issues by using multiple detector channels, light sources, and filtering.

Sugar-rich diets and poor dental hygiene promote the formation of a biofilm (plaque) that strongly adheres to the dental enamel surface and fosters the evolution of aciduric bacteria. The acid contributes to demineralization of the exterior tooth enamel, which accelerates after the pH drops below a critical value (∼5.5) for extended time periods resulting in the need for restorative procedures. Preventative techniques to alert the dentist and caries-susceptible patients regarding vulnerability to dental decay require a clinical measure of plaque activity. Therefore, there is a need to evaluate the acid production capability of plaque deposits in the pits and fissures of occlusal and interproximal regions. A ratiometric fluorescence pH-sensing device has been developed using an FDA-approved dye and LED excitation. Fluorescein spectral profiles were collected using a spectrometer and analyzed with a spectral unmixing algorithm for calibration over the pH range of 4.5 to 7. An in vivo pilot study on human subjects was performed using a sucrose rinse to accelerate bacterial metabolism and to measure the time-dependent drop in pH. The optical system is relatively immune to confounding factors such as photobleaching, dye concentration, and variation in excitation intensity associated with earlier dye-based pH measurement techniques.

A method of stimulating neurons in a patient's cochlea. The method uses a plurality of cochlear electrodes, substantially arranged in a linear array within the cochlea and a relatively distant electrode. Charge is injected through a first one of the cochlear electrodes and an opposite charge is injected on either the relatively distant electrode; or a set of adjacent cochlear electrodes, being adjacent to the first one of the cochlear electrodes; or on a combination of the relatively distant electrode and the set of adjacent electrodes; and choosing the electrode or electrodes on which to inject charge in dependency on sound volume to be represented.

In a patient with plasma cell leukemia, associated with pleural effusion, ultrastructural studies of the peripheral blood plasma cells showed an abundance of cytoplasmic fibrils. The nature of fibrils was not clarified, but they were not amyloid fibrils. This finding, coupled with a liaterature review, suggests that the cytoplasmic fibrils in plasma cells may be an additional cytological feature of this rare form of leukemia.