Oral enzyme therapy for maple syrup urine disease (MSUD) suppresses plasma leucine levels in intermediate MSUD mice and healthy nonhuman primates.

Maple syrup urine disease (MSUD) is an inborn error of branched-chain amino acid metabolism affecting several thousand individuals worldwide. MSUD patients have elevated levels of plasma leucine and its metabolic product α-ketoisocaproate (KIC), which can lead to severe neurotoxicity, coma, and death. Patients must maintain a strict diet of protein restriction and medical formula, and periods of noncompliance or illness can lead to acute metabolic decompensation or cumulative neurological impairment. Given the lack of therapeutic options for MSUD patients, we sought to develop an oral enzyme therapy that can degrade leucine within the gastrointestinal tract prior to its systemic absorption and thus enable patients to maintain acceptable plasma leucine levels while broadening their access to natural protein. We identified a highly active leucine decarboxylase enzyme from Planctomycetaceae bacterium and used directed evolution to engineer the enzyme for stability to gastric and intestinal conditions. Following high-throughput screening of over 12 000 enzyme variants over 9 iterative rounds of evolution, we identified a lead variant, LDCv10, which retains activity following simulated gastric or intestinal conditions in vitro. In intermediate MSUD mice or healthy nonhuman primates given a whey protein meal, oral treatment with LDCv10 suppressed the spike in plasma leucine and KIC and reduced the leucine area under the curve in a dose-dependent manner. Reduction in plasma leucine correlated with decreased brain leucine levels following oral LDCv10 treatment. Collectively, these data support further development of LDCv10 as a potential new therapy for MSUD patients.

Global survey-based assessment of lifestyle changes during the COVID-19 pandemic.

Along with the major impact on public health, the COVID-19 outbreak has caused unprecedented concerns ranging from sudden loss of employment to mental stress and anxiety. We implemented a survey-based data collection platform to characterize how the COVID-19 pandemic has affected the socio-economic, physical and mental health conditions of individuals. We focused on three broad areas, namely, changes in social interaction during home confinement, economic impact and their health status. We identified a substantial increase in virtual interaction among individuals, which might be a way to alleviate the sudden unprecedented mental health burden, exacerbated by general awareness about viral infections or other manifestations associated with them. The majority of participants (85%) lived with one or more companions and unemployment issues did not affect 91% of the total survey takers, which was one of the crucial consequences of the pandemic. Nevertheless, measures such as an increased frequency of technology-aided distant social interaction, focus on physical fitness and leisure activities were adopted as coping mechanisms during this period of home isolation. Collectively, these metrics provide a succinct and informative summary of the socio-economic and health impact of the COVID-19 pandemic on the individuals. Findings from our study reflect that continuous surveillance of the psychological consequences for outbreaks should become routine as part of preparedness efforts worldwide. Given the limitations of analyzing the large number of variables, we have made the raw data publicly available on the OMF ME/CFS Data Center server to facilitate further analyses (https://igenomed.stanford.edu/dataset/survey-study-on-lifestyle-changes-during-covid-19-pandemic).

COUNTEN, an AI-Driven Tool for Rapid and Objective Structural Analyses of the Enteric Nervous System.

The enteric nervous system (ENS) consists of an interconnected meshwork of neurons and glia residing within the wall of the gastrointestinal (GI) tract. While healthy GI function is associated with healthy ENS structure, defined by the normal distribution of neurons within ganglia of the ENS, a comprehensive understanding of normal neuronal distribution and ganglionic organization in the ENS is lacking. Current methodologies for manual enumeration of neurons parse only limited tissue regions and are prone to error, subjective bias, and peer-to-peer discordance. There is accordingly a need for robust, and objective tools that can capture and quantify enteric neurons within multiple ganglia over large areas of tissue. Here, we report on the development of an AI-driven tool, COUNTEN (COUNTing Enteric Neurons), which is capable of accurately identifying and enumerating immunolabeled enteric neurons, and objectively clustering them into ganglia. We tested and found that COUNTEN matches trained humans in its accuracy while taking a fraction of the time to complete the analyses. Finally, we use COUNTEN's accuracy and speed to identify and cluster thousands of ileal myenteric neurons into hundreds of ganglia to compute metrics that help define the normal structure of the ileal myenteric plexus. To facilitate reproducible, robust, and objective measures of ENS structure across mouse models, experiments, and institutions, COUNTEN is freely and openly available to all researchers.

Gallbladder motility in children with celiac disease before and after gluten-free diet.

BACKGROUND: Gallbladder (GB) hypomotility has been reported in adults with celiac disease (CD), but there is no literature on GB dysfunction in children with CD. We aimed to study GB motility in children with CD, before and after a gluten-free diet (GFD), using ultrasonography (USG) and technetium-99 labeled mebrofenin hepatobiliary scintigraphy (HBS). METHODS: Children with newly diagnosed CD were enrolled and evaluated for GB ejection fraction (GBEF) using HBS and USG. Those with reduced GBEF on initial HBS were again evaluated after 6 months of strict GFD and the results were compared. RESULTS: Of the 50 children with CD (mean age 9±2.1 years, 54% boys), 16% (n=8) had a low GBEF at baseline (19±13%). These children had a significantly greater delay in diagnosis compared to those with normal GBEF (6.5±2.0 vs. 2.3±1.2 years, P<0.001). A significant improvement in GBEF was noted on HBS post GFD (74±12%1 vs. 9±13%, P<0.001). GBEF also improved significantly as assessed by USG parameters after GFD (P<0.001). The fasting GB volume decreased (5.7±1.4 vs. 10.2±2.6, P=0.002), with a significant improvement in percentage postprandial GB volume change (52±10.5% vs. 24±16.5%, P=0.007) compared to baseline pre-GFD values. Orocecal transit time was also increased in children with reduced GBEF. CONCLUSIONS: GB function is impaired in at least 16% of children with CD at diagnosis and is reversible with GFD. GB dysfunction is significantly associated with a delayed diagnosis and may be a part of general gastrointestinal dysmotility.

A cephalosporin-chemiluminescent conjugate increases beta-lactamase detection sensitivity by four orders of magnitude.

The expression of beta-lactamases in bacteria is a central cause of drug resistance. In this report, we present a beta-lactamase chemiluminescent probe, termed CCP, which can for the first time detect beta-lactamase activity via chemiluminescence and can detect beta lactamase with a sensitivity that is 4-orders of magnitude higher than the commercially available fluorescent lactamase substrate fluorocillin.

Incomplete functional and morphological recovery after acute and acute recurrent pancreatitis in children.

BACKGROUND AND AIM: There is lack of data on functional and morphological recovery after an attack of acute pancreatitis (AP) or acute recurrent pancreatitis (ARP) in children. This study aims to evaluate the functional impairment and morphological changes in the pancreas after recovery. METHODS: All consecutive patients presenting with AP (n = 61) or ARP (n = 35), as per standard diagnostic criteria, were enrolled. After 2 months of pancreatitis, fecal elastase-1 (FE-1) (µg/g) and 2-h oral glucose tolerance test to calculate oral disposition index (DIo ) (mmol/L) (ß-cell function) were performed. Morphological changes were assessed by endoscopic ultrasound and transabdominal ultrasound. Patients with chronic pancreatitis (CP) (n = 27) and healthy children (HC) (n = 26) were included as controls for functional parameters. RESULTS: At a median follow up of 12 (4-44) and 11 (2-108) months, 66.7% and 75.9% (P = 0.57) of AP and ARP demonstrated exocrine insufficiency (FE-1 < 200), respectively. Mean (SD) FE-1 was 183.64 ± 150.94 (AP), 135.70 ± 103.80 (ARP), 46.56 ± 30.20 (CP), and 240.00 ± 181.83 (HC) (P < 0.001; anova) (AP vs CP, ARP vs CP, and CP vs HC; P < 0.001). Prediabetes due to insulin resistance was seen in 16.6% and 22.6% (P = 0.56) of AP and ARP. Median (interquartile range) DIo (mmol/L) was comparable between AP (4.20 [2.36, 8.3]) and HC (5.20 [2.89, 8.68]), but was low in ARP (2.97 [1.80, 5.12]), which was comparable with CP (1.91 [1.20, 2.83]). Endoscopic ultrasound demonstrated morphological changes in 25% and 37% (P = 0.34) of AP and ARP, respectively. CONCLUSION: There was high frequency of biochemical evidence of exocrine insufficiency. ß-Cell function (DIo ) was preserved among AP but was poor in ARP. Nearly one-third showed morphological changes in imaging.

Nitro Sulfonyl Fluorides are a new pharmacophore for the development of antibiotics.

The development of antibiotics against Gram-negative bacteria is a central problem in drug discovery. In this report, we demonstrate that aromatic sulfonyl fluorides with a nitro group in their ortho position have remarkable antibacterial activity and are active against drug-resistant pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA), multidrug resistant Acinetobacter baumannii, and Pseudomonas aeruginosa.

Thiophene bridged hydrocyanine - a new fluorogenic ROS probe.

Hydrocyanines are a class of commonly used reactive oxygen species (ROS) fluorescent imaging probes, which can image ROS in cell culture, organ culture, and in vivo. However, despite their widespread use, hydrocyanines have several drawbacks that limit their effectiveness, such as a high rate of auto-oxidation, a small Stokes shift, and poor water solubility. In addition, the hydrocyanines oxidize into cyanine dyes, which themselves decompose in the presence of ROS, and this further lowers their sensitivity towards detecting ROS. In this report, we present a new hydrocyanine analog, termed as thiophene-bridged hydrocyanine (TBHC), which has its double bonds replaced with a bisthiophene. TBHC is 8.06-fold more stable to auto-oxidation than the hydrocyanine hydro-Cy5 and is significantly better at imaging ROS in cell culture.

Biomaterials and Nanotherapeutics for Enhancing Skin Wound Healing.

Wound healing is an intricate process that requires complex coordination between many cell types and an appropriate extracellular microenvironment. Chronic wounds often suffer from high protease activity, persistent infection, excess inflammation, and hypoxia. While there has been intense investigation to find new methods to improve cutaneous wound care, the management of chronic wounds, burns, and skin wound infection remain challenging clinical problems. Ideally, advanced wound dressings can provide enhanced healing and bridge the gaps in the healing processes that prevent chronic wounds from healing. These technologies have great potential for improving outcomes in patients with poorly healing wounds but face significant barriers in addressing the heterogeneity and clinical complexity of chronic or severe wounds. Active wound dressings aim to enhance the natural healing process and work to counter many aspects that plague poorly healing wounds, including excessive inflammation, ischemia, scarring, and wound infection. This review paper discusses recent advances in the development of biomaterials and nanoparticle therapeutics to enhance wound healing. In particular, this review focuses on the novel cutaneous wound treatments that have undergone significant preclinical development or are currently used in clinical practice.

Syndesome Therapeutics for Enhancing Diabetic Wound Healing.

Chronic wounds represent a major healthcare and economic problem worldwide. Advanced wound dressings that incorporate bioactive compounds have great potential for improving outcomes in patients with chronic wounds but significant challenges in designing treatments that are effective in long-standing, nonhealing wounds. Here, an optimized wound healing gel was developed that delivers syndecan-4 proteoliposomes ("syndesomes") with fibroblast growth factor-2 (FGF-2) to enhance diabetic wound healing. In vitro studies demonstrate that syndesomes markedly increase migration of keratinocytes and fibroblasts isolated from both nondiabetic and diabetic donors. In addition, syndesome treatment leads to increased endocytic processing of FGF-2 that includes enhanced recycling of FGF-2 to the cell surface after uptake. The optimized syndesome formulation was incorporated into an alginate wound dressing and tested in a splinted wound model in diabetic, ob/ob mice. It was found that wounds treated with syndesomes and FGF-2 have markedly enhanced wound closure in comparison to wounds treated with only FGF-2. Moreover, syndesomes have an immunomodulatory effect on wound macrophages, leading to a shift toward the M2 macrophage phenotype and alterations in the wound cytokine profile. Together, these studies show that delivery of exogenous syndecan-4 is an effective method for enhancing wound healing in the long-term diabetic diseased state.

Syndecan-4 enhances PDGF-BB activity in diabetic wound healing.

UNLABELLED: Non-healing ulcers are a common consequence of long-term diabetes and severe peripheral vascular disease. These non-healing wounds are a major source of morbidity in patients with diabetes and place a heavy financial burden on the healthcare system. Growth factor therapies are an attractive strategy for enhancing wound closure in non-healing wounds but have only achieved mixed results in clinical trials. Platelet derived growth factor-BB (PDGF-BB) is the only currently approved growth factor therapy for non-healing wounds. However, PDGF-BB therapy is not effective in many patients and requires high doses that increase the potential for side effects. In this work, we demonstrate that syndecan-4 delivered in a proteoliposomal formulation enhances PDGF-BB activity in diabetic wound healing. In particular, syndecan-4 proteoliposomes enhance the migration of keratinocytes derived from patients with diabetes. In addition, syndecan-4 proteoliposomes sensitize keratinocytes to PDGF-BB stimulation, enhancing the intracellular signaling response to PDGF-BB. We further demonstrated that co-therapy with syndecan-4 proteoliposomes enhanced wound closure in diabetic, hyperlipidemic ob/ob mice. Wounds treated with both syndecan-4 proteoliposomes and PDGF-BB had increased re-epithelization and angiogenesis in comparison to wounds treated with PDGF-BB alone. Moreover, the wounds treated with syndecan-4 proteoliposomes and PDGF-BB also had increased M2 macrophages and reduced M1 macrophages, suggesting syndecan-4 delivery induces immunomodulation within the healing wounds. Together our findings support that syndecan-4 proteoliposomes markedly improve PDGF-BB efficacy for wound healing and may be useful in enhancing treatments for non-healing wounds. STATEMENT OF SIGNIFICANCE: Non-healing wounds are major healthcare issue for patients with diabetes and peripheral vascular disease. Growth factor therapies have potential for healing chronic wounds but have not been effective for many patients. PDGF-BB is currently the only approved growth factor for enhancing wound healing. However, it has not seen widespread adoption due to limited efficacy and high cost. In this work, we have developed an enhancing agent that improves the activity of PDGF-BB in promoting wound healing in animals with diabetes. This co-therapy may be useful in improving the efficacy of PDGFBB and enhance its safety through lowering the dose of growth factor needed to improve wound healing.

Glypican-1 nanoliposomes for potentiating growth factor activity in therapeutic angiogenesis.

Therapeutic angiogenesis is a highly appealing concept for treating tissues that become ischemic due to vascular disease. A major barrier to the clinical translation of angiogenic therapies is that the patients that are in the greatest need of these treatments often have long term disease states and co-morbidities, such as diabetes and obesity, that make them resistant to angiogenic stimuli. In this study, we identified that human patients with type 2 diabetes have reduced levels of glypican-1 in the blood vessels of their skin. The lack of this key co-receptor in the tissue may make the application of exogenous angiogenic growth factors or cell therapies ineffective. We created a novel therapeutic enhancer for growth factor activity consisting of glypican-1 delivered in a nanoliposomal carrier (a "glypisome"). Here, we demonstrate that glypisomes enhance FGF-2 mediated endothelial cell proliferation, migration and tube formation. In addition, glypisomes enhance FGF-2 trafficking by increasing both uptake and endosomal processing. We encapsulated FGF-2 or FGF-2 with glypisomes in alginate beads and used these to deliver localized growth factor therapy in a murine hind limb ischemia model. Co-delivery of glypisomes with FGF-2 markedly increased the recovery of perfusion and vessel formation in ischemic hind limbs of wild type and diabetic mice in comparison to mice treated with FGF-2 alone. Together, our findings support that glypisomes are effective means for enhancing growth factor activity and may improve the response to local angiogenic growth factor therapies for ischemia.

Syndecan-4 Enhances Therapeutic Angiogenesis after Hind Limb Ischemia in Mice with Type 2 Diabetes.

Delivering syndecan-4 with FGF-2 improves the effectiveness of FGF-2 therapy for ischemia in the diabetic disease state. The syndecan-4 proteoliposomes significantly enhance in vitro tubule formation as well as blood perfusion and vessel density in the ischemic hind limbs of diseased ob/ob mice. Syndecan-4 therapy also induces a marked immunomodulation in the tissues, increasing the polarization of macrophages toward the M2 phenotype.

Nanoscale strategies: treatment for peripheral vascular disease and critical limb ischemia.

Peripheral vascular disease (PVD) is one of the most prevalent vascular diseases in the U.S. afflicting an estimated 8 million people. Obstruction of peripheral arteries leads to insufficient nutrients and oxygen supply to extremities, which, if not treated properly, can potentially give rise to a severe condition called critical limb ischemia (CLI). CLI is associated with extremely high morbidities and mortalities. Conventional treatments such as angioplasty, atherectomy, stent implantation and bypass surgery have achieved some success in treating localized macrovascular disease but are limited by their invasiveness. An emerging alternative is the use of growth factor (delivered as genes or proteins) and cell therapy for PVD treatment. By delivering growth factors or cells to the ischemic tissue, one can stimulate the regeneration of functional vasculature network locally, re-perfuse the ischemic tissue, and thus salvage the limb. Here we review recent advance in nanomaterials, and discuss how their application can improve and facilitate growth factor or cell therapies. Specifically, nanoparticles (NPs) can serve as drug carrier and target to ischemic tissues and achieve localized and sustained release of pro-angiogenic proteins. As nonviral vectors, NPs can greatly enhance the transfection of target cells with pro-angiogenic genes with relatively fewer safety concern. Further, NPs may also be used in combination with cell therapy to enhance cell retention, cell survival and secretion of angiogenic factors. Lastly, nano/micro fibrous vascular grafts can be engineered to better mimic the structure and composition of native vessels, and hopefully overcome many complications/limitations associated with conventional synthetic grafts.

The diagnostic criteria for allergic bronchopulmonary aspergillosis in children with poorly controlled asthma need to be re-evaluated.

AIM: The aim of this study was to examine the association between allergic bronchopulmonary aspergillosis (ABPA) and poorly controlled asthma in children and appraise the diagnostic criteria. METHODS: The study included 100 children with poorly controlled asthma. We diagnosed ABPA using the Aspergillus skin test, pulmonary function test, total and specific immunoglobulin E (IgE) to Aspergillus fumigatus, chest radiograph and high-resolution computed tomography. Patients were diagnosed and classified according to the Rosenberg-Patterson criteria for ABPA. The cut-off value for total serum IgE was calculated by receiver operating characteristics curve analysis. RESULTS: Of 100 children with poorly controlled asthma, 26 patients were ABPA positive. There was a significant difference in the forced expiratory volume in 1-sec/forced vital capacity ratio between ABPA positive (0.78 ± 0.14) and negative (0.87 ± 0.15) children (p = 0.008). ABPA positive children were categorised as seropositive, central bronchiectasis and other radiological findings. The receiver operating characteristics curve was constructed, and a value of 1200 IU/mL of total IgE was observed, with 88.5% sensitivity and 70.5% specificity. CONCLUSION: This study showed an association between ABPA and poorly controlled asthma in children and suggests a higher cut-off value of total IgE for the diagnosis of ABPA.

Overcoming disease-induced growth factor resistance in therapeutic angiogenesis using recombinant co-receptors delivered by a liposomal system.

Current treatment options for ischemia include percutaneous interventions, surgical bypass or pharmacological interventions aimed at slowing the progression of vascular disease. Unfortunately, while each of these treatment modalities provides some benefit for patients in the short-term, many patients have resistant or recurrent disease that is poorly managed by these therapies. A highly appealing strategy for treating ischemic disease is to stimulate the revascularization of the tissue to restore blood flow. While many techniques have been explored in this regard, clinically effective angiogenic therapies remain elusive. Here, we hypothesized that the presence of co-morbid disease states inherently alters the ability of the body to respond to angiogenic therapies. Using a mouse model of diabetes and obesity, we examined alterations in the major components for the signaling pathways for FGF-2, VEGF-A and PDGF under normal and high fat dietary conditions. In skeletal muscle, a high fat diet increased levels of growth factor receptors and co-receptors including syndecan-1, syndecan-4 and PDGFR-α in wild-type mice. These increases did not occur in Ob/Ob mice on a high fat diet and there was a significant decrease in protein levels for neuropilin-1 and heparanase in these mice. With the aim of increasing growth factor effectiveness in the context of disease, we examined whether local treatment with alginate gel-delivered FGF-2 and syndecan-4 proteoliposomes could overcome the growth factor resistance in these mice. This treatment enhanced the formation of new blood vessels in Ob/Ob mice by 6 fold in comparison to FGF-2 delivered alone. Our studies support that disease states cause a profound shift in growth factor signaling pathways and that co-receptor-based therapies have potential to overcome growth factor resistance in the context of disease.