Management of Laparoscopic Adjustable Gastric Band Erosion: A Case Report.

Gastric banding was one of the first operations to gain popularity within the field of bariatric surgery. This case details one patient's presentation and subsequent management of gastric band erosion with the hope of guiding other physicians and supporting the decreased use of gastric banding. The patient, a 61-year-old Caucasian female, presented to the bariatric clinic complaining of a multiyear history of epigastric pain and acid reflux, which was refractory to treatment with proton pump inhibitors. She had a history of laparoscopic adjustable gastric band (LAGB) placement in 2007. She was initially successful in achieving weight loss and maintained regular band adjustments but was lost to follow-up and regained a body mass index (BMI) of 41.59 kg/m2. Evaluation with upper gastrointestinal (GI) endoscopy was recommended and performed. This revealed a LAGB in its entirety with tubing within the gastric fundus. Removal with dual endoscopy and abdominal laparoscopy was recommended and scheduled. During attempts to remove the band using an endoscopic snare, significant difficulty was encountered. Ultimately, an endoscopic rat-tooth grasper was used to lyse the band and tubing into four sections for complete removal. The subcutaneous port of the band was successfully removed laparoscopically, and the patient was discharged from the operating room. She reported limited pain in the postoperative suite but was lost to follow-up regarding long-term symptom relief. This report describes the presentation and management of one patient's experience with a known complication of LAGB-band erosion. This complication necessitated two additional procedures with anesthesia and placed the patient at increased risk for esophageal perforation, complications related to sedation, and the development of abdominal adhesions. Her case aims to support the decreasing prevalence of LAGBs within bariatric surgery and hopes to guide other physicians challenged with the management of similar cases.

Whole-Milk Dairy Foods: Biological Mechanisms Underlying Beneficial Effects on Risk Markers for Cardiometabolic Health.

Lifestyle modifications that include adherence to healthy dietary patterns that are low in saturated fat have been associated with reduced risk for cardiovascular disease, the leading cause of death globally. Whole-milk dairy foods, including milk, cheese, and yogurt, are leading sources of saturated fat in the diet. Dietary guidelines around the world recommend the consumption of low-fat and fat-free dairy foods to obtain overall healthy dietary patterns that help meet nutrient recommendations while keeping within recommended calorie and saturated fat limitations. A body of observational and clinical evidence indicates, however, that whole-milk dairy food consumption, despite saturated fat content, does not increase the risk for cardiovascular disease. This review describes the proposed biological mechanisms underlying inverse associations between whole-milk dairy food consumption and risk markers for cardiometabolic health, such as altered lipid digestion, absorption, and metabolism; influence on the gut microflora; and regulation of oxidative stress and inflammatory responses. The dairy food matrix, a term used to describe how the macronutrients and micronutrients and other bioactive components of dairy foods are differentially packaged and compartmentalized among fluid milk, cheese, and yogurt, may dictate how each affects cardiovascular risk. Current evidence indicates consideration of dairy foods as complex food matrices, rather than delivery systems for isolated nutrients, such as saturated fatty acids, is warranted.

Sensitivity and binding kinetics of an ultra-sensitive chemiluminescent enzyme-linked immunosorbent assay at arrays of antibodies.

We have characterized the sensitivity and kinetics of a multiplex immunoassay system based on detection of chemiluminescence (CL) at arrays of antibodies. This enzyme-linked immunosorbent assay (ELISA) was based on the spotting of different antibodies in a circular pattern at the bottom of a well of a microtiter plate. Sandwich immunocomplexes within each spot were labeled with horse radish peroxidase, and CL was generated locally to each spot in the array from turnover of luminol substrate. CL from the arrays across the plate was collected in single images; long exposure times were used to maximize sensitivity, and short exposure times were used to extend the dynamic range at higher signals. Image analysis was used to determine the intensity of light from each spot in the array, and intensity was converted to concentration of protein via comparison to a calibration curve. To determine the intrinsic sensitivity of the CL ELISA array, streptavidin horseradish peroxidase (SA-HRP) was captured on an array spotted with biotinylated detection antibodies. The limit of detection (LOD) of SA-HRP was 105 aM, or 3200 enzymes per 50 µL. A single-plex assay for prostate specific antigen (PSA) was developed that had an LOD of 79 aM when the microtiter plate was shaken orbitally, comparable to the most sensitive immunoassays reported to date. Normalization of CL signals in the PSA assay to signal per molecule of SA-HRP showed that the efficiency of the shaken assay was ~40%. When the plates were not shaken, the efficiency was ~4.5%, i.e., ~9-fold lower than when shaken. To better understand the theoretical basis of the sensitivity of these assays, we developed COMSOL numerical models of the binding kinetics at the array for plates that were shaken orbitally and those not shaken. Experimental data from the orbitally shaken PSA assay were best modeled by inertial mixing in a three-layer system that included a 8-µm-thick concentration boundary layer. Experimental data from the unshaken PSA assay were well modeled by diffusion-limited kinetics. A single-plex assay for IL-10 was developed with an LOD of 69 aM or 1.5 fg/mL, and used to measure this cytokine in plasma and serum of 10 healthy individuals. A 5-plex assay for IL-5, IL-6, IL-10, IL-22, and TNF-α was developed with LODs of 56 aM, 237 aM, 69 aM, 88 aM, and 373 aM, respectively. The assay was used to measure these 5 cytokines in the plasma and serum of the same individuals. The correlation in concentration of IL-10 measured in single-plex and multiplex assays was good (r2 = 0.89; bias = 14.5%). The factors that result in the high sensitivity of CL ELISA arrays-mostly high signal to noise ratio of extended chemiluminescent imaging-are discussed. This multiplex CL ELISA could be used for sensitive profiling of multiple proteins for in vitro diagnostics and biomarker detection in the development of therapeutics.

Dietary Fat and Risk for Type 2 Diabetes: a Review of Recent Research.

PURPOSE OF REVIEW: It is estimated that over 400 million people worldwide are living with diabetes. Excess adiposity is the strongest risk factor for non-insulin-dependent diabetes, type 2. Lifestyle interventions have demonstrated that diet plays a critical role in preventing the onset of type 2 diabetes. Dietary fat is not only a source of energy and nutrients, but also bioactive fatty acids. The purpose of this review was to examine data from recent prospective cohort studies and dietary interventions to determine if there are benefits to fat consumption on diabetes risk. RECENT FINDINGS: The consumption of fish and marine n-3 fatty acids among Asian populations and regular-fat dairy foods and trans-palmitoleic acid (trans-16, n-7) among Western populations may be associated with reduced risk for type 2 diabetes. Whereas some dietary fat may contribute to reduced diabetes risk, lifestyle recommendations to balance calories with physical activity are prudent at this time.

Cell Labeling with Magneto-Endosymbionts and the Dissection of the Subcellular Location, Fate, and Host Cell Interactions.

PURPOSE: The purposes of this study are to characterize magneto-endosymbiont (ME) labeling of mammalian cells and to discern the subcellular fate of these living contrast agents. MEs are novel magnetic resonance imaging (MRI) contrast agents that are being used for cell tracking studies. Understanding the fate of MEs in host cells is valuable for designing in vivo cell tracking experiments. PROCEDURES: The ME's surface epitopes, contrast-producing paramagnetic magnetosomal iron, and genome were studied using immunocytochemistry (ICC), Fe and MRI contrast measurements, and quantitative polymerase chain reaction (qPCR), respectively. These assays, coupled with other common assays, enabled validation of ME cell labeling and dissection of ME subcellular processing. RESULTS: The assays mentioned above provide qualitative and quantitative assessments of cell labeling, the subcellular localization and the fate of MEs. ICC results, with an ME-specific antibody, qualitatively shows homogenous labeling with MEs. The ferrozine assay shows that MEs have an average of 7 fg Fe/ME, ∼30 % of which contributes to MRI contrast and ME-labeled MDA-MB-231 (MDA-231) cells generally have 2.4 pg Fe/cell, implying ∼350 MEs/cell. Adjusting the concentration of Fe in the ME growth media reduces the concentration of non-MRI contrast-producing Fe. Results from the qPCR assay, which quantifies ME genomes in labeled cells, shows that processing of MEs begins within 24 h in MDA-231 cells. ICC results suggest this intracellular digestion of MEs occurs by the lysosomal degradation pathway. MEs coated with listeriolysin O (LLO) are able to escape the primary phagosome, but subsequently co-localize with LC3, an autophagy-associated molecule, and are processed for digestion. In embryos, where autophagy is transiently suppressed, MEs show an increased capacity for survival and even replication. Finally, transmission electron microscopy (TEM) of ME-labeled MDA-231 cells confirms that the magnetosomes (the MRI contrast-producing particles) remain intact and enable in vivo cell tracking. CONCLUSIONS: MEs are used to label mammalian cells for the purpose of cell tracking in vivo, with MRI. Various assays described herein (ICC, ferrozine, and qPCR) allow qualitative and quantitative assessments of labeling efficiency and provide a detailed understanding of subcellular processing of MEs. In some cell types, MEs are digested, but the MRI-producing particles remain. Coating with LLO allows MEs to escape the primary phagosome, enhances retention slightly, and confirms that MEs are ultimately processed by autophagy. Numerous intracellular bacteria and all endosymbiotically derived organelles have evolved molecular mechanisms to avoid intracellular clearance, and identification of the specific processes involved in ME clearance provides a framework on which to develop MEs with enhanced retention in mammalian cells.

Characterization of Magneto-Endosymbionts as MRI Cell Labeling and Tracking Agents.

PURPOSE: Magneto-endosymbionts (MEs) show promise as living magnetic resonance imaging (MRI) contrast agents for in vivo cell tracking. Here we characterize the biomedical imaging properties of ME contrast agents, in vitro and in vivo. PROCEDURES: By adapting and engineering magnetotactic bacteria to the intracellular niche, we are creating magneto-endosymbionts (MEs) that offer advantages relative to passive iron-based contrast agents (superparamagnetic iron oxides, SPIOs) for cell tracking. This work presents a biomedical imaging characterization of MEs including: MRI transverse relaxivity (r 2) for MEs and ME-labeled cells (compared to a commercially available iron oxide nanoparticle); microscopic validation of labeling efficiency and subcellular locations; and in vivo imaging of a MDA-MB-231BR (231BR) human breast cancer cells in a mouse brain. RESULTS: At 7T, r 2 relaxivity of bare MEs was higher (250 s-1 mM-1) than that of conventional SPIO (178 s-1 mM-1). Optimized in vitro loading of MEs into 231BR cells yielded 1-4 pg iron/cell (compared to 5-10 pg iron/cell for conventional SPIO). r 2 relaxivity dropped by a factor of ~3 upon loading into cells, and was on the same order of magnitude for ME-loaded cells compared to SPIO-loaded cells. In vivo, ME-labeled cells exhibited strong MR contrast, allowing as few as 100 cells to be detected in mice using an optimized 3D SPGR gradient-echo sequence. CONCLUSIONS: Our results demonstrate the potential of magneto-endosymbionts as living MR contrast agents. They have r 2 relaxivity values comparable to traditional iron oxide nanoparticle contrast agents, and provide strong MR contrast when loaded into cells and implanted in tissue.

Regular-Fat Dairy and Human Health: A Synopsis of Symposia Presented in Europe and North America (2014-2015).

In recent history, some dietary recommendations have treated dairy fat as an unnecessary source of calories and saturated fat in the human diet. These assumptions, however, have recently been brought into question by current research on regular fat dairy products and human health. In an effort to disseminate, explore and discuss the state of the science on the relationship between regular fat dairy products and health, symposia were programmed by dairy industry organizations in Europe and North America at The Eurofed Lipids Congress (2014) in France, The Dairy Nutrition Annual Symposium (2014) in Canada, The American Society for Nutrition Annual Meeting held in conjunction with Experimental Biology (2015) in the United States, and The Federation of European Nutrition Societies (2015) in Germany. This synopsis of these symposia describes the complexity of dairy fat and the effects regular-fat dairy foods have on human health. The emerging scientific evidence indicates that the consumption of regular fat dairy foods is not associated with an increased risk of cardiovascular disease and inversely associated with weight gain and the risk of obesity. Dairy foods, including regular-fat milk, cheese and yogurt, can be important components of an overall healthy dietary pattern. Systematic examination of the effects of dietary patterns that include regular-fat milk, cheese and yogurt on human health is warranted.

Novel MRI Contrast Agent from Magnetotactic Bacteria Enables In Vivo Tracking of iPSC-derived Cardiomyocytes.

Therapeutic delivery of human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iCMs) represents a novel clinical approach to regenerate the injured myocardium. However, methods for robust and accurate in vivo monitoring of the iCMs are still lacking. Although superparamagnetic iron oxide nanoparticles (SPIOs) are recognized as a promising tool for in vivo tracking of stem cells using magnetic resonance imaging (MRI), their signal persists in the heart even weeks after the disappearance of the injected cells. This limitation highlights the inability of SPIOs to distinguish stem cell viability. In order to overcome this shortcoming, we demonstrate the use of a living contrast agent, magneto-endosymbionts (MEs) derived from magnetotactic bacteria for the labeling of iCMs. The ME-labeled iCMs were injected into the infarcted area of murine heart and probed by MRI and bioluminescence imaging (BLI). Our findings demonstrate that the MEs are robust and effective biological contrast agents to track iCMs in an in vivo murine model. We show that the MEs clear within one week of cell death whereas the SPIOs remain over 2 weeks after cell death. These findings will accelerate the clinical translation of in vivo MRI monitoring of transplanted stem cell at high spatial resolution and sensitivity.

Emission spectra of bioluminescent reporters and interaction with mammalian tissue determine the sensitivity of detection in vivo.

In vivo bioluminescence imaging depends on light emitted by luciferases in the body overcoming the effect of tissue attenuation. Understanding this relationship is essential for detection and quantification of signal. We have studied four codon optimized luciferases with different emission spectra, including enzymes from firefly (FLuc), click beetle (CBGr68, CBRed) and Renilla reniformins (hRLuc). At 25 degrees C, the in vitro lambda(max) of these reporters are 578, 543, 615, and 480 nm, respectively; at body temperature, 37 degrees C, the brightness increases and the firefly enzyme demonstrates a 34-nm spectral red shift. Spectral shifts and attenuation due to tissue effects were evaluated using a series of 20-nm bandpass filters and a cooled charge-coupled device (CCD) camera. Attenuation increased and the spectra of emitted light was red shifted for signals originating from deeper within the body relative to superficial origins. The tissue attenuation of signals from CBGr68 and hRLuc was greater than from those of Fluc and CBRed. To further probe tissue effects, broad spectral emitters were created through gene fusions between CBGr68 and CBRed. These resulted in enzymes with broader emission spectra, featuring two peaks whose intensities are differentially affected by temperature and tissue depth. These spectral measurement data allow for improved understanding of how these reporters can be used in vivo and what they can reveal about biological processes in living subjects.

Insights and perspectives on dietary modifications to reduce the risk of cardiovascular disease.

This article summarizes presentations from "Insights and Perspectives on Dietary Modifications to Reduce the Risk of Cardiovascular Disease," a symposium held at the ASN Annual Meeting and Scientific Sessions in conjunction with Experimental Biology 2014 in San Diego, CA on 26 April 2014. Presenters reviewed historic and current evidence on the relation between diet and cardiovascular disease (CVD) to identify gaps in knowledge, discuss the promises and pitfalls of macronutrient replacement strategies in the diet, and suggest various options for issuing dietary guidance aimed at reducing the burden of CVD morbidity and mortality. Observational studies and clinical trials indicate that overall diet quality have a marked impact on health benefits, which is shifting the emphasis on recommending healthful dietary patterns to focusing only on single nutrients or foods.

Non-invasive detection of a small number of bioluminescent cancer cells in vivo.

Early detection of tumors can significantly improve the outcome of tumor treatment. One of the most frequently asked questions in cancer imaging is how many cells can be detected non-invasively in a live animal. Although many factors limit such detection, increasing the light emission from cells is one of the most effective ways of overcoming these limitations. Here, we describe development and utilization of a lentiviral vector containing enhanced firefly luciferase (luc2) gene. The resulting single cell clones of the mouse mammary gland tumor (4T1-luc2) showed stable light emission in the range of 10,000 photons/sec/cell. In some cases individual 4T1-luc2 cells inserted under the skin of a nu/nu mouse could be detected non-invasively using a cooled CCD camera in some cases. In addition, we showed that only few cells are needed to develop tumors in these mice and tumor progression can be monitored right after the cells are implanted. Significantly higher luciferase activity in these cells allowed us to detect micrometastases in both, syngeneic Balb/c and nu/nu mice.