Genetically engineered probiotic E. coli Nissle to consume amino acids associated with orphan metabolic diseases

Orphan metabolic diseases are rare genetic defects that interfere with metabolism due to ineffective or missing enzymes. Two of them, Phenylketonuria (PKU) and Maple Syrup Urine Disease (MSUD) are defined by accumulation of amino acids to toxic levels due to defective metabolism of protein break down products. PKU is caused by a defect in the gene encoding phenylalanine hydroxylase (PAH). MSUD is caused by a defect in a multi-enzyme complex found in mitochondria called branched chain ɑ-ketoacid dehydrogenase “BCKDH”. Without the activity of these enzymes, the amino acid phenylalanine (Phe) in the case of PKU or the branched-chain amino acids leucine (Leu), isoleucine and valine for MSUD build up to neurotoxic levels in the blood and brain, leading to neurological deficits. Current treatment options focus on dietary protein restriction, are insufficient and, unfortunately, can lead to a failure to thrive. Lifelong compliance with a prescription diet is also a concern. We have genetically engineered Nissle, a probiotic strain of E. coli, to reduce serum phenylalanine and leucine levels in patients with PKU or MSUD; preclinical data supporting the activity of these strains are described. Please click Additional Files below to see the full abstract

Engineering and manufacturing of probiotic E. Coli to treat metabolic disorder

The fields of synthetic biology and microbiome research developed greatly over the last decade. The convergence of those two disciplines is now enabling the development of new therapeutic strategies, using engineered microbes that operate from within the gut as living medicines. Inborn errors of metabolism represent candidate diseases for these therapeutics, particularly those disorders where a toxic metabolite causing a syndrome is also present in the intestinal lumen. Phenylketonuria (PKU), a rare inherited disease caused by a defect in phenylalanine hydroxylase (PAH) activity, is one such disease and is characterized by the accumulation of systemic phenylalanine (Phe) that can lead to severe neurological deficits unless patients are placed on a strict low-Phe diet. As an alternative treatment, Escherichia coli Nissle (EcN), a well-characterized probiotic, was genetically modified to efficiently import and degrade Phe (SYNB1618). The coupled expression of a Phe transporter with a Phe ammonia lyase (PAL) allows rapid conversion of Phe into trans-cinnamic acid (TCA) in vitro, which is then further metabolized by the host to hippuric acid (HA) and excreted in the urine. Experiments conducted in the enu2-/- PKU mouse model showed that the oral administration of SYNB1618 is able to significantly reduce blood Phe levels triggered by subcutaneous Phe injection. Decreases in circulating Phe levels were associated with proportional increases in urinary HA, confirming that Phe metabolism was caused by the engineered pathway in SYNB1618. Subsequent studies have shown that SYNB1618 is similarly operative in a non-human primate model, providing a translational link to inform future human clinical studies. Consistent with preclinical studies, recent Phase 1/2a clinical data demonstrate that oral administration of SYNB1618 resulted in significant dose-dependent production of biomarkers specifically associated with SYNB1618 activity, demonstrating proof-of-mechanism of this cell therapy

Antibiotic-induced Severe Neutropenia with Multidrug-Dependent Antineutrophil Antibodies Developed in A Child with Streptococcus pneumoniae Infection

Drug-induced neutropenia (DIN), particularly that in which antibiotic-dependent antineutrophil antibodies have been detected, is a rare disorder. We report the case of a child with pneumococcal pneumonia, who experienced severe neutropenia during various antibiotic treatments. We detected 4 kinds (cefotaxim, augmentin, vancomycin, and tobramycin) of antibiotic-dependent antineutrophil antibodies by using the mixed passive hemagglutination assay (MPHA) technique with this child

Engineering of probiotic E.coli to treat metabolic disorders

The fields of synthetic biology and microbiome research developed greatly over the last decade. The convergence of those two disciplines is now enabling the development of new therapeutic strategies, using engineered microbes that operate from within the gut as living medicines. Inborn errors of metabolism represent candidate diseases for these therapeutics, particularly those disorders where a toxic metabolite causing a syndrome is also present in the intestinal lumen. Phenylketonuria (PKU), a rare inherited disease caused by a defect in phenylalanine hydroxylase (PAH) activity, is one such disease and is characterized by the accumulation of systemic phenylalanine (Phe) that can lead to severe neurological deficits unless patients are placed on a strict low-Phe diet. As an alternative treatment, Escherichia coli Nissle (EcN), a well-characterized probiotic, was genetically modified to efficiently import and degrade Phe (SYN-PKU). The coupled expression of a Phe transporter with a Phe ammonia lyase (PAL) allows rapid conversion of Phe into trans-cinnamic acid (TCA) in vitro, which is then further metabolized by the host to hippuric acid (HA) and excreted in the urine. Experiments conducted in the enu2-/- PKU mouse model showed that the oral administration of SYN-PKU is able to significantly reduce blood Phe levels triggered by subcutaneous Phe injection. Decreases in circulating Phe levels were associated with proportional increases in urinary HA, confirming that Phe metabolism was caused by the engineered pathway in SYN-PKU. Subsequent studies have shown that SYN-PKU is similarly operative in a non-human primate model, providing a translational link to inform future human clinical studies. In addition to SYN-PKU, a second EcN strain was genetically engineered to rapidly import and degrade branched-chain amino acids (BCAAs) for the treatment of maple syrup urine disease (SYN-MSUD). MSUD, similar to PKU, is a rare genetic disorder caused by a defect in branched-chain ketoacid dehydrogenase activity leading to the toxic accumulation of BCAAs, particularly leucine, and their ketoacid derivatives. The controlled expression in SYN-MSUD of two BCAA transporters, a leucine dehydrogenase, a ketoacid decarboxylase and an alcohol dehydrogenase, result in the efficient degradation of BCAAs into branched-chain alcohols. In a mouse model of MSUD, the oral delivery of SYN-MSUD suppressed the increase in blood BCAAs level induced by a high-protein challenge and prevented the associated moribund phenotype, as measured by locomotor activity. In conclusion, the therapeutic effects observed with SYN-PKU and SYN-MSUD in pre-clinical studies support the further evaluation of engineered microbes as promising approaches for serious inborn errors of metabolism

Epidemiology of Knee and Hip Arthroplasty: A Systematic Review§

We present a systematic review of epidemiologic studies of Total Knee Arthroplasty (TKA) and Total Hip Arthroplasty (THA). The studies summarized in this systematic review provide us with estimates of arthroplasty utilization rates, underlying disease frequency and its trends and differences in utilization rates by age, gender and ethnicity among other factors. Among these, many studies are registry-based that assessed utilization rates using data from major orthopedic centers that may provide some understanding of underlying diagnosis and possibly time-trends. Several studies are population-based cross-sectional, which provide estimates of prevalence of TKA and THA. Population-based cohort studies included in this review provide the best estimates of incidence and utilization rates, time-trends and differences in these rates by important patient characteristics (age, gender, ethnicity and others). This article reviews the current published literature in the area and highlights the main findings

Using Intervention Mapping to develop an occupational advice intervention to aid return to work following hip and knee replacement in the United Kingdom

Background There are increasing numbers of total hip replacements (THR) and total knee replacements (TKR) being performed in patients of working age. Providing patients undergoing TKR and THR with return to work advice might facilitate return to work. The aim of this paper is to report on the process used to systematically develop an occupational advice intervention to be delivered in hospital for those undergoing arthroplasty. Methods The six-step Intervention Mapping (IM) approach to development, implementation and evaluation of a theory and evidence-based interventions was followed. This paper reports on the development of the intervention covered by steps 1 to 4 of the IM process. Steps 1-3 gathered data on current practice and barriers to change using a mixed methods approach (cohort study of patients undergoing THR or TKR, stakeholder interviews, survey of practice, evidence synthesis) and provided a theoretical framework for intervention development. Step 4 used information from steps 1-3 in combination with a Delphi consensus process to develop the intervention and the associated tools and materials to facilitate its delivery. Results The final intervention identified included a number of core principles including: early patient identification; delivery of key information to patients and their employers; assessment and support by a member of the orthopaedic team; procedures for escalation based on patient need; mechanisms to support communication; and training and support for the clinical teams delivering care. A total of 13 patient and 20 staff performance objectives as delivery requirements, supported by a range of tools, roles and training resources. The intervention addressed outcomes based at the individual and interpersonal levels of the ecological model. Conclusions Following the IM approach resulted in a structured and justified occupational intervention for delivery in secondary care for patients undergoing total hip and knee replacement. The feasibility of the intervention will subsequently be tested alongside further investigation to establish its effectiveness and cost-effectiveness. Key Words Intervention Mapping Return to Work Occupational advice Arthroplasty Hip Kne

Asteroseismology and Interferometry

Asteroseismology provides us with a unique opportunity to improve our understanding of stellar structure and evolution. Recent developments, including the first systematic studies of solar-like pulsators, have boosted the impact of this field of research within Astrophysics and have led to a significant increase in the size of the research community. In the present paper we start by reviewing the basic observational and theoretical properties of classical and solar-like pulsators and present results from some of the most recent and outstanding studies of these stars. We centre our review on those classes of pulsators for which interferometric studies are expected to provide a significant input. We discuss current limitations to asteroseismic studies, including difficulties in mode identification and in the accurate determination of global parameters of pulsating stars, and, after a brief review of those aspects of interferometry that are most relevant in this context, anticipate how interferometric observations may contribute to overcome these limitations. Moreover, we present results of recent pilot studies of pulsating stars involving both asteroseismic and interferometric constraints and look into the future, summarizing ongoing efforts concerning the development of future instruments and satellite missions which are expected to have an impact in this field of research.Comment: Version as published in The Astronomy and Astrophysics Review, Volume 14, Issue 3-4, pp. 217-36

Nano-carrier based drug delivery systems for sustained antimicrobial agent release from orthopaedic cementous material

Total joint replacement (TJR), such as hip and knee replacement, is a popular procedure worldwide. Prosthetic joint infections (PJI) after this procedure have been widely reported, where treatment of such infections is complex with high cost and prolonged hospital stay. In cemented arthroplasties, the use of antibiotic loaded bone cement (ALBC) is a standard practice for the prophylaxis and treatment of PJI. Recently, the development of bacterial resistance by pathogenic microorganisms against most commonly used antibiotics increased the interest in alternative approaches for antimicrobial delivery systems such as nanotechnology. This review summarizes the efforts made to improve the antimicrobial properties of PMMA bone cements using nanotechnology based antibiotic and non-antibiotic delivery systems to overcome drawbacks of ALBC in the prophylaxis and treatment of PJIs after hip and knee replacement