ABSTRACT
With the emergence and rapid spreading of NDM-1 and existence of clinically relevant VIM-1 and IMP-1, discovery of pan inhibitors targeting metallo-beta-lactamases (MBLs) became critical in our battle against bacterial infection. Concurrent with our fragment and high-throughput screenings, we performed a knowledge-based search of known metallo-beta-lactamase inhibitors (MBLIs) to identify starting points for early engagement of medicinal chemistry. A class of compounds exemplified by 11, discovered earlier as B. fragilis metallo-beta-lactamase inhibitors, was selected for in silico virtual screening. From these efforts, compound 12 was identified with activity against NDM-1 only. Initial exploration on metal binding design followed by structure-guided optimization led to the discovery of a series of compounds represented by 23 with a pan MBL inhibition profile. In in vivo studies, compound 23 in combination with imipenem (IPM) robustly lowered the bacterial burden in a murine infection model and became the lead for the invention of MBLI clinical candidates.
Subject(s)
Bacterial Infections , beta-Lactamase Inhibitors , Animals , Mice , beta-Lactamase Inhibitors/pharmacology , beta-Lactamase Inhibitors/therapeutic use , beta-Lactamase Inhibitors/chemistry , Imipenem/pharmacology , Imipenem/therapeutic use , beta-Lactamases/metabolism , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/chemistry , Microbial Sensitivity TestsABSTRACT
Coagulation Factor XII (FXII) plays a critical role in thrombosis. What is unclear is the level of enzyme occupancy of FXIIa that is needed for efficacy and the impact of FXIIa inhibition on cerebral embolism. A selective activated FXII (FXIIa) inhibitor, recombinant human albumin-tagged mutant Infestin-4 (rHA-Mut-inf), was generated to address these questions. rHA-Mut-inf displayed potency comparable to the original wild-type HA-Infestin-4 (human FXIIa inhibition constant = 0.07 and 0.12 nM, respectively), with markedly improved selectivity against Factor Xa (FXa) and plasmin. rHA-Mut-inf binds FXIIa, but not FXII zymogen, and competitively inhibits FXIIa protease activity. Its mode of action is hence akin to typical small-molecule inhibitors. Plasma shift and aPTT studies with rHA-Mut-inf demonstrated that calculated enzyme occupancy for FXIIa in achieving a putative aPTT doubling target in human, nonhuman primate, and rabbit is more than 99.0%. The effects of rHA-Mut-inf in carotid arterial thrombosis and microembolic signal (MES) in middle cerebral artery were assessed simultaneously in rabbits. Dose-dependent inhibition was observed for both arterial thrombosis and MES. The ED50 of thrombus formation was 0.17 mg/kg i.v. rHA-Mut-inf for the integrated blood flow and 0.16 mg/kg for thrombus weight; the ED50 for MES was 0.06 mg/kg. Ex vivo aPTT tracked with efficacy. In summary, our findings demonstrated that very high enzyme occupancy will be required for FXIIa active site inhibitors, highlighting the high potency and exquisite selectivity necessary for achieving efficacy in humans. Our MES studies suggest that targeting FXIIa may offer a promising strategy for stroke prevention associated with thromboembolic events.
Subject(s)
Blood Coagulation , Factor XIIa/antagonists & inhibitors , Insect Proteins/pharmacology , Intracranial Embolism , Intracranial Thrombosis , Recombinant Fusion Proteins/pharmacology , Serum Albumin/pharmacology , Animals , Anticoagulants/pharmacology , Blood Coagulation/drug effects , Blood Coagulation/physiology , Fibrinolytic Agents/pharmacology , Intracranial Embolism/blood , Intracranial Embolism/drug therapy , Intracranial Thrombosis/blood , Intracranial Thrombosis/drug therapy , Models, Animal , Rabbits , Serum Albumin, HumanABSTRACT
Factor XI (FXI) is an integral component of the intrinsic pathway of the coagulation cascade and plays a critical role in thrombus formation. Because its role in the pathogenesis of cerebral microembolic signals (MES) is unclear, this study used a potent and selective small molecule inhibitor of FXIa, compound 1, to assess the effect of FXI blockade in our recently established preclinical model of cerebral MES induced by FeCl3 injury of the carotid artery in male New Zealand White rabbits. Ascending doses of compound 1 were evaluated simultaneously for both carotid arterial thrombosis by a Doppler flowmeter and MES in the middle cerebral artery by a transcranial Doppler. Plasma drug exposure and pharmacodynamic responses to compound 1 treatment were also assessed. The effective dose for 50% inhibition (ED50) of thrombus formation was 0.003 mg/kg/h compound 1, i.v. for the integrated blood flow, 0.004 mg/kg/h for reduction in thrombus weight, and 0.106 mg/kg/h for prevention of MES. The highest dose, 3 mg/kg/h compound 1, achieved complete inhibition in both thrombus formation and MES. In addition, we assessed the potential bleeding liability of compound 1 (5 mg/kg/h, i.v., >1250-fold ED50 levels in arterial thrombosis) in rabbits using a cuticle bleeding model, and observed about 2-fold (not statistically significant) prolongation in bleeding time. Our study demonstrates that compound 1 produced a robust and dose-dependent inhibition of both arterial thrombosis and MES, suggesting that FXIa blockade may represent a novel therapeutic strategy for the reduction in MES in patients at risk for ischemic stroke.
Subject(s)
Anticoagulants/pharmacology , Blood Coagulation/drug effects , Carotid Artery Thrombosis , Factor XIa/antagonists & inhibitors , Intracranial Embolism , Animals , Blood Coagulation/physiology , Carotid Artery Thrombosis/blood , Carotid Artery Thrombosis/complications , Carotid Artery Thrombosis/diagnostic imaging , Carotid Artery Thrombosis/drug therapy , Disease Models, Animal , Drug Design , Injections, Intravenous , Intracranial Embolism/blood , Intracranial Embolism/diagnostic imaging , Intracranial Embolism/etiology , Intracranial Embolism/prevention & control , Male , Rabbits , Ultrasonography, Doppler, Transcranial/methodsABSTRACT
The back squat is a well-researched and widely used exercise to enhance fundamental movement competency that creates a foundation for optimal mechanical strategies during a broad range of activities. The primary commentary introduced the Back Squat Assessment (BSA): a criterion based assessment of the back squat that delineates 30 potentially observable functional deficits. This follow-up commentary provides a targeted system of training cues and exercises to supplement the BSA to guide corrective intervention. We propose a criterion driven approach to corrective exercise that can support practitioners in their goal to help individuals achieve movement competency in the back squat.
ABSTRACT
Fundamental movement competency is essential for participation in physical activity and for mitigating the risk of injury, which are both key elements of health throughout life. The squat movement pattern is arguably one of the most primal and critical fundamental movements necessary to improve sport performance, to reduce injury risk and to support lifelong physical activity. Based on current evidence, this first (1 of 2) report deconstructs the technical performance of the back squat as a foundation training exercise and presents a novel dynamic screening tool that incorporates identification techniques for functional deficits that limit squat performance and injury resilience. The follow-up report will outline targeted corrective methodology for each of the functional deficits presented in the assessment tool.
ABSTRACT
El manuscrito actual es la traducción del Posicionamiento sobre el Entrenamiento de Fuerza para Jóvenes: el Consenso Internacional de 2014. El consenso original es a su vez una adaptación del posicionamiento de la United Kingdom Strength and Conditioning Association. Ha sido revisado y respaldado por organizaciones profesionales relevantes en los campos de la medicina del deporte, la ciencia de la actividad física y la pediatría. Los autores de este articulo fueron seleccionados entre los campos de la ciencia del ejercicio pediátrico, la medicina pediátrica, la educación física, la preparación física y la medicina del deporte. El manuscrito fue publicado originalmente en el British Journal of Sports Medicine y representa el documento final ratificado oficialmente a nivel ejecutivo por cada organización que lo respalda. Para enlazar con la versión original del manuscrito en ingles diríjanse a: http://bjsm.bmj.com/content/early/2013/09/20/bjsports-2013-092952.full
The current manuscript is a translation of the Position statement on youth resistance training: the 2014 International Consensus. The original manuscript was adapted from the oficial position statement of the UK Strength and Conditioning Association on youth resistance training. It was subsequently reviewed and endorsed by leading professional organisations within the fields of sports medicine, exercise science and paediatrics. The authorship team for this article was selected from the fields of paediatric exercise science, paediatric medicine, physical education, strength and conditioning and sports medicine
Subject(s)
Humans , Muscle Strength/physiology , Weight Lifting/physiology , Physical Education and Training/standards , Athletic Injuries/prevention & controlABSTRACT
The current manuscript has been adapted from the official position statement of the UK Strength and Conditioning Association on youth resistance training. It has subsequently been reviewed and endorsed by leading professional organisations within the fields of sports medicine, exercise science and paediatrics. The authorship team for this article was selected from the fields of paediatric exercise science, paediatric medicine, physical education, strength and conditioning and sports medicine.
Subject(s)
Exercise/physiology , Resistance Training/methods , Adolescent , Athletic Injuries/prevention & control , Bone Development/physiology , Child , Female , Humans , Male , Mental Health , Muscle Strength/physiology , Practice Guidelines as Topic , Psychomotor Performance/physiology , Weight Lifting/physiologyABSTRACT
THE PROBLEM: The decline and disinterest in regular physical activity among contemporary youth have created an immediate need to identify and treat these youngsters before they become resistant to our interventions. KEY POINTS: Exercise-deficit disorder is a term used to describe a condition characterized by reduced levels of physical activity that are inconsistent with current public health recommendations. Pediatric physical therapists are in an enviable position to identify and treat exercise-deficit disorder in youth, regardless of body size or physical ability. RECOMMENDATION: If pediatric physical therapists want to become advocates for children's health and wellness, there is a need to address limitations in the physical therapist professional curriculum, educate families on the benefits of wellness programming, and initiate preventive strategies that identify youth who are inactive, promote daily physical activity, and encourage healthy lifestyle choices.
Subject(s)
Adolescent Behavior , Child Behavior , Health Promotion/methods , Physical Therapy Modalities , Sedentary Behavior , Adolescent , Child , Child Welfare , Exercise , Humans , Motor ActivityABSTRACT
Lecithin:cholesterol acyltransferase (LCAT) is the key circulating enzyme responsible for high-density lipoprotein (HDL) cholesterol esterification, HDL maturation, and potentially reverse cholesterol transport. To further explore LCAT's mechanism of action on lipoprotein metabolism, we employed adeno-associated viral vector (AAV) serotype 8 to achieve long-term (32-week) high level expression of human LCAT in hCETP;Ldlr(+/-) mice, and characterized the lipid profiles in detail. The mice had a marked increase in HDL cholesterol, HDL particle size, and significant reduction in low-density lipoprotein (LDL) cholesterol, plasma triglycerides, and plasma apoB. Plasma LCAT activity significantly increased with humanized substrate specificity. HDL cholesteryl esters increased in a fashion that fits human LCAT specificity. HDL phosphatidylcholines trended toward decrease, with no change observed for HDL lysophosphatidylcholines. Triglycerides reduction appeared to reside in all lipoprotein particles (very low-density lipoprotein (VLDL), LDL, and HDL), with HDL triglycerides composition highly reflective of VLDL, suggesting that changes in HDL triglycerides were primarily driven by the altered triglycerides metabolism in VLDL. In summary, in this human-like model for lipoprotein metabolism, AAV8-mediated overexpression of human LCAT resulted in profound changes in plasma lipid profiles. Detailed lipid analyses in the lipoprotein particles suggest that LCAT's beneficial effect on lipid metabolism includes not only enhanced HDL cholesterol esterification but also improved metabolism of apoB-containing particles and triglycerides. Our findings thus shed new light on LCAT's mechanism of action and lend support to its therapeutic potential in treating dyslipidemia.
Subject(s)
Cholesterol Ester Transfer Proteins/metabolism , Dependovirus/genetics , Dyslipidemias/therapy , Gene Transfer Techniques , Genetic Therapy , Genetic Vectors , Lipids/blood , Phosphatidylcholine-Sterol O-Acyltransferase/genetics , Receptors, LDL/deficiency , Animals , Cholesterol Ester Transfer Proteins/genetics , Disease Models, Animal , Dyslipidemias/enzymology , Dyslipidemias/genetics , Humans , Liver/enzymology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Particle Size , Phosphatidylcholine-Sterol O-Acyltransferase/metabolism , Receptors, LDL/genetics , Time FactorsABSTRACT
As more children and adolescents participate in sports and conditioning activities (sometimes without consideration for cumulative workload), it is important to establish age-appropriate training guidelines that may reduce the risk of sports-related injury and enhance athletic performance. The purpose of this article is to review the scientific evidence on youth strength and conditioning and to provide age-appropriate recommendations for integrating different strength and conditioning activities into a well-designed program that is safe, effective, and enjoyable. Integrative training is defined as a program or plan that incorporates general and specific strength and conditioning activities that enhance both health- and skill-related components of physical fitness. The cornerstone of integrative training is age-appropriate education and instruction by qualified professionals who understand the physical and psychosocial uniqueness of children and adolescents.
Subject(s)
Athletic Injuries/prevention & control , Athletic Performance/physiology , Muscle Strength/physiology , Physical Education and Training/methods , Physical Fitness , Adolescent , Child , Humans , Physical Education and Training/standardsABSTRACT
This article provide evidences to outline a novel theory used to define the mechanisms related to increased risk of ACL injury in female athletes. In addition, this discussion will include theoretical constructs for the description of the mechanisms that lead to increased risk. Finally, a clinical application section will outline novel neuromuscular training techniques designed to target deficits that underlie the proposed mechanism of increased risk of knee injury in female athletes.
Subject(s)
Abdominal Muscles/physiology , Hip/physiology , Knee Injuries/prevention & control , Physical Education and Training/methods , Biomechanical Phenomena , Female , Humans , Knee Injuries/physiopathology , Muscle Contraction/physiology , Muscle Strength/physiology , Range of Motion, Articular/physiology , Risk FactorsABSTRACT
A series of heteroaryl-substituted bis-trifluoromethyl carbinols were prepared and evaluated as malonyl-CoA decarboxylase (MCD) inhibitors. Some thiazole-based derivatives showed potent in vitro MCD inhibitory activities and significantly increased glucose oxidation rates in isolated working rat hearts.
Subject(s)
Carboxy-Lyases/antagonists & inhibitors , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Heterocyclic Compounds/chemistry , Methanol/chemical synthesis , Methanol/pharmacology , Animals , Drug Evaluation, Preclinical , Enzyme Activation/drug effects , Enzyme Inhibitors/chemistry , Glucose/chemistry , Glucose/metabolism , Heart/drug effects , In Vitro Techniques , Methanol/analogs & derivatives , Molecular Structure , Oxidation-Reduction , Rats , Stereoisomerism , Structure-Activity RelationshipABSTRACT
The purpose of this study was to determine whether or not a relationship existed between upper-body power and class level among female club gymnasts. Sixty female gymnasts between the ages of 10 and 11 and between class levels 5 and 8 participated in the study. The distance of a medicine-ball throw was used to measure upper-body power. Three types of throws--overhead forward throw, overhead backward throw, and chest pass--were performed with a 6-lb rubber medicine ball. The mean distances of 2 trails were calculated and categorized into age group and class level. An analysis of variance design was used to determine the relationship between mean throw distances and throw type, age, and class level. No significant differences were found between mean throw distances and throw type, age, or class level. The results of this study show no relationship between upper-body power of female gymnasts and throw type, age, and class level.
Subject(s)
Arm/physiology , Gymnastics/physiology , Muscle, Skeletal/physiology , Analysis of Variance , Biomechanical Phenomena , Child , Female , Gymnastics/classification , Humans , Pilot ProjectsABSTRACT
The recombinant human malonyl-CoA decarboxylase (hMCD) was overexpressed in Escherichia coli with and without the first 39 N-terminal amino acids via a cleavable MBP-fusion construct. Proteolytic digestion using genenase I to remove the MBP-fusion tag was optimized for both the full length and truncated hMCD. The apo-hMCD enzymes were solubilized and purified to homogeneity. Steady-state kinetic characterization showed similar kinetic parameters for the MBP-fused and apo-hMCD enzymes with an apparent Km value of approximately 330-520 microM and a turnover rate kcat of 13-28s(-1). For the apo-hMCD enzymes, the N-terminal truncated hMCD was well tolerated over a broad pH range (pH 4-10); whereas the full-length hMCD appeared to be stable only at pH >/= 8.5. Our results showed that the N-terminal region of hMCD has no effect on the catalytic activity of the enzyme but plays a role in the folding process and conformation stability of hMCD.