Plasmid-mediated Kluyvera-like arnBCADTEF operon confers colistin (hetero)resistance to Escherichia coli.

The use of colistin as a last resort antimicrobial is compromised by the emergence of resistant enterobacteria with acquired determinants like mcr genes, mutations that activate the PmrAB system and by still unknown mechanisms. This work analyzed 74 E. coli isolates from healthy swine, turkey or bovine, characterizing their colistin resistance determinants. The mcr-1 gene, detected in 69 isolates, was the main determinant found among which 45% were carried by highly mobile plasmids, followed by four strains lacking previously known resistance determinants or two with mcr-4 (one in addition to mcr-1), whose phenotypes were not transferred by conjugation. Although a fraction of isolates carrying mcr-1 or mcr-4 genes also presented missense polymorphisms in pmrA or pmrB, constitutive activation of PmrAB was not detected, in contrast to strains with mutations that confer colistin resistance. The expression of mcr genes negatively controls the transcription of the arnBCADTEF operon itself, a down-regulation that was also observed in the four isolates lacking known resistance determinants, three of them sharing the same macrorestriction and plasmid profiles. Genomic sequencing of one of these strains, isolated from a bovine in 2015, revealed a IncFII plasmid of 62.1 Kb encoding an extra copy of the arnBCADTEF operon closely related to Kluyvera ascorbata homologs. This element, called pArnT1, was cured by ethidium bromide and the cells lost resistance to colistin in parallel. Furthermore, a susceptible E. coli strain acquired heteroresistance after transformation with pArnT1 or pBAD24 carrying the Kluyvera-like arnBCADTEF operon, revealing it as a new colistin resistance determinant.

Inheritance of Yield Components and Morphological Traits in Avocado cv. Hass From "Criollo" "Elite Trees" via Half-Sib Seedling Rootstocks.

Grafting induces precocity and maintains clonal integrity in fruit tree crops. However, the complex rootstock × scion interaction often precludes understanding how the tree phenotype is shaped, limiting the potential to select optimum rootstocks. Therefore, it is necessary to assess (1) how seedling progenies inherit trait variation from elite 'plus trees', and (2) whether such family superiority may be transferred after grafting to the clonal scion. To bridge this gap, we quantified additive genetic parameters (i.e., narrow sense heritability-h 2, and genetic-estimated breeding values-GEBVs) across landraces, "criollo", "plus trees" of the super-food fruit tree crop avocado (Persea americana Mill.), and their open-pollinated (OP) half-sib seedling families. Specifically, we used a genomic best linear unbiased prediction (G-BLUP) model to merge phenotypic characterization of 17 morpho-agronomic traits with genetic screening of 13 highly polymorphic SSR markers in a diverse panel of 104 avocado "criollo" "plus trees." Estimated additive genetic parameters were validated at a 5-year-old common garden trial (i.e., provenance test), in which 22 OP half-sib seedlings from 82 elite "plus trees" served as rootstocks for the cv. Hass clone. Heritability (h 2) scores in the "criollo" "plus trees" ranged from 0.28 to 0.51. The highest h 2 values were observed for ribbed petiole and adaxial veins with 0.47 (CI 95%0.2-0.8) and 0.51 (CI 0.2-0.8), respectively. The h 2 scores for the agronomic traits ranged from 0.34 (CI 0.2-0.6) to 0.39 (CI 0.2-0.6) for seed weight, fruit weight, and total volume, respectively. When inspecting yield variation across 5-year-old grafted avocado cv. Hass trees with elite OP half-sib seedling rootstocks, the traits total number of fruits and fruits' weight, respectively, exhibited h 2 scores of 0.36 (± 0.23) and 0.11 (± 0.09). Our results indicate that elite "criollo" "plus trees" may serve as promissory donors of seedling rootstocks for avocado cv. Hass orchards due to the inheritance of their outstanding trait values. This reinforces the feasibility to leverage natural variation from "plus trees" via OP half-sib seedling rootstock families. By jointly estimating half-sib family effects and rootstock-mediated heritability, this study promises boosting seedling rootstock breeding programs, while better discerning the consequences of grafting in fruit tree crops.

Impact of the Covid-19 epidemic on a US sample of patients with myasthenia gravis.

Introduction: The Covid-19 pandemic has devastated the world and demonstrated the inadequacy of health care in the United States. To assess its impact, the Rare Disease Clinical Research Network conducted a survey to assess the pandemic on the rare disease community of patients, including those with myasthenia gravis (MG). Methods: A cross-sectional survey was designed to target people or their care givers who live in the United States, have a rare disease, and are under 90 years of age. Respondents logged onto a dedicated web page and completed the survey online, which requested demographic, disease-specific, drug treatment, and symptom information as well as assessment of Covid-19 impact on them. The survey was open from May 2020 to December 2020. Results: Five hundred ninety-four with self-reported myasthenia gravis completed the survey, which was the largest number of respondents. Sixty percent of respondents were women with a mean age of 60 years. Eighty-nine percent identified as White. Respondents did not appreciate a worsening of symptoms after the pandemic. Only 7 respondents reported the diagnosis of Covid-19 but 11% indicated they had difficulty accessing care at the time of the survey. Discussion and Conclusion: Patients with MG complained of worse access to medical care during the early months of the pandemic, including challenges in diagnosis of suspected Covid-19 infection. A major limitation of the survey is its inability to access minority populations. Nevertheless, the results of the Rare Disease Clinical Research Network (RCDRN) survey of patients with MG provide clear evidence that the pandemic has demonstrated the deficiencies in US healthcare.

Impact of Covid-19 Pandemic on Patients with Myasthenia Gravis Deeper understanding of the consequences of the Covid-19 pandemic on people with rare diseases is critically important in order to enhance health care in the future. The Rare Disease Clinical Research Network (RDCRN) performed a web-based survey of individuals with rare diseases in the first year of the pandemic utilizing questions to assess the impact of the pandemic on their symptoms, access to healthcare, and medication use. Five hundred and ninety-four respondents reported having myasthenia gravis (MG). The average age was 60 years and 60% were women. Nearly ninety percent were White. A large minority indicated difficulty accessing health care and nearly a third used telemedicine. Only seven respondents indicated a diagnosis of Covid-19 but many more had symptoms consistent with infection. Overall, there was no increase in symptoms of MG after the beginning of the pandemic. The pandemic has demonstrated the deficiencies in US healthcare, and these are appreciated in the results of the RCDRN survey of patients with MG. The RDCRN will continue to survey the rare disease community to understand the ongoing impact of the Covid-19 pandemic.

Retraction notice to "Proof of concept efficacy study of intranasal stabilized isoamyl nitrite (SIAN) in Rhesus monkeys against acute cyanide poisoning" [Regul. Toxicol. Pharmacol. 123 (2021) 104927].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editors-in-Chief as the authors were unable to provide documentation of approval for the interinstitutional assurance/vertebrate animal section of the paper by the relevant authority, Public Health Service (PHS) Office of Laboratory Animal Welfare (OLAW) in the time that was provided.

RETRACTED: Proof of concept efficacy study of intranasal stabilized isoamyl nitrite (SIAN) in rhesus monkeys against acute cyanide poisoning.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editors-in-Chief as the authors were unable to provide documentation of approval for the interinstitutional assurance /vertebrate animal section of the paper by the relevant authority, Public Health Service (PHS) Office of Laboratory Animal Welfare (OLAW) in the time that was provided.

Síndrome MELAS en pediatría. Reporte de caso / MELAS Syndrome in pediatrics. Case report

Resumen Introducción. El síndrome de encefalopatía mitocondrial, acidosis láctica y episodios similares a un accidente cerebrovascular (MELAS, por su sigla en inglés) es una de las enfermedades mitocondriales más frecuentes. Estas patologías se caracterizan por ser hereditarias, multisistémicas y progresivas, y por causar un compromiso predominantemente neurológico que provoca discapacidad y mortalidad, por lo que el diagnóstico temprano y la consejería genética son de gran importancia para mejorar el pronóstico de estos pacientes. Presentación del caso. Paciente femenina de cinco años quien fue llevada a consulta al servicio de pediatría por convulsión y ataxia, y en quien se evidenció retraso psicomotor. Aunque los estudios de neuroimagen fueron normales, se observó hiperlactatemia. Se encontró una relación lactato/piruvato >20, por lo que se sospechó enfermedad mitocondrial. Seis meses después, la paciente presentó deterioro neurológico progresivo caracterizado por alteración de la consciencia, mioclonías y hemiparesia. Se realizó tomografía axial computarizada de cráneo y resonancia magnética por espectroscopia que permitieron identificar una lesión isquémica occipital y aumento del lactato cerebral, respectivamente. Para confirmar el diagnóstico de síndrome MELAS, se solicitó estudio de ADN mitocondrial, en el que se observó la mutación m.3243A>G en el gen MT-TL1. La paciente tuvo un rápido deterioro, presentando una involución de las capacidades adquiridas, falleciendo a los cuatro años del inicio de los signos clínicos. Conclusión. Las enfermedades mitocondriales deben ser consideradas en pacientes con antecedentes de epilepsia y otras alteraciones neurológicas como ataxia e involución del neurodesarrollo.

Abstract Introduction: MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke) syndrome is the most common mitochondrial disease. These diseases are hereditary, multi-systemic and progressive, and lead to a predominant neurological involvement that causes disability and death, so early diagnosis and genetic counseling are of great importance for improving the prognosis of these patients. Case presentation: Five-year-old female patient who was taken to the pediatrics service of the hospital due to epileptic seizure, psychomotor retardation and ataxia. Although in the first medical consultation her neuroimaging studies were normal, hyperlactatemia was identified. In addition, a lactate to pyruvate ratio >20 was observed, so a mitochondrial disease was suspected. Six months later, the patient showed progressive deterioration of her health condition. A cranial CT scan and a magnetic resonance spectroscopy allowed the identification of an ischemic lesion in the occipital lobe and increased cerebral lactate levels, respectively. In order to confirm the MELAS syndrome diagnosis, a mitochondrial DNA study was requested, in which the m.3243A>G mutation was found. Unfortunately, the patient had a rapid deterioration of her health condition, showing a regression of her acquired functions, and died four years after the onset of the clinical signs. Conclusion: Mitochondrial diseases diagnosis should always be considered in patients with a history of epilepsy and other neurological disorders such as ataxia and neurodevelopmental regression.

Towards a Treatment for Gulf War Illness: A Consensus Docking Approach.

INTRODUCTION: Gulf War Illness (GWI) currently has no known cure and affects soldiers deployed during the Persian Gulf War. It is thought to originate from exposure to neurotoxicants combined with battlefield stress, and previous research indicates that treatment first involves inhibition of interleukin-2 and tumor necrosis factor alpha, followed by the glucocorticoid receptor. However, the off-target effects of pharmaceuticals hinder development of a drug treatment therapy. MATERIALS AND METHODS: AutoDock 4.2, AutoDock Vina, and Schrodinger's Glide were used to perform consensus docking, a computational technique where pharmaceuticals are screened against targets using multiple scoring algorithms to obtain consistent binding affinities. FDA approved pharmaceuticals were docked against the above-mentioned immune and stress targets to determine a drug therapy for GWI. Additionally, the androgen and estrogen targets were screened to avoid pharmaceuticals with off-target interactions. RESULTS: While suramin bound to both immune targets with high affinity, top binders of the hormonal and glucocorticoid targets were non-specific towards their respective proteins, possibly due to high structure similarity between these proteins. CONCLUSIONS: Development of a drug treatment therapy for GWI is threatened by the tight interplay between the immune and hormonal systems, often leading to drug interactions. Increasing knowledge of these interactions can lead to break-through therapies.

From parallel to partnership.

PURPOSE: In the USA, there has recently been an unprecedented convergence of complementary/alternative medicine (CAM) with mainstream biomedical care. This confluence may lead to a deeply rooted philosophical conflict. This qualitative study works to identify factors that health-care leaders can use, which will build a pathway to greater integrative practice between medical doctors and CAM practitioners - from parallel existence to partnership - by examining the tensions between biomedical medicine and naturopathic medicine. The purpose of this study is to offer short-term suggestions for partnership and long-term recommendations for better understanding. DESIGN/METHODOLOGY/APPROACH: An original qualitative study using semi-structured with CAM practitioners and biomedical practitioners. FINDINGS: Areas of conflict that are preventing synergy are identified and a pathway for health-care leaders to follow to create greater integration and partnerships is suggested. RESEARCH LIMITATIONS/IMPLICATIONS: This is a qualitative and exploratory study that has significant limitations on generalizability. PRACTICAL IMPLICATIONS: This study suggest steps that both types of health-care practitioners can take to increase their success at working together on an individual level, a group level, an organizational level and on an industry-wide basis, as well as provide a specific pathway to create greater integrative practice for health-care leaders. SOCIAL IMPLICATIONS: The results indicate that stronger partnerships between different types of medical practitioners increase patient choice, patient satisfaction and outcomes. ORIGINALITY/VALUE: Increasing interested in CAM modalities is driving more contact between CAM practitioners and biomedical practitioners. This contact is best established in partnership between practitioners rather than in parallel. This original research outlines the sources of conflict and provides recommendations for encouraging greater synergy.

Using a Consensus Docking Approach to Predict Adverse Drug Reactions in Combination Drug Therapies for Gulf War Illness.

Gulf War Illness (GWI) is a chronic multisymptom illness characterized by fatigue, musculoskeletal pain, and gastrointestinal and cognitive dysfunction believed to stem from chemical exposures during the 1990⁻1991 Persian Gulf War. There are currently no treatments; however, previous studies have predicted a putative multi-intervention treatment composed of inhibiting Th1 immune cytokines followed by inhibition of the glucocorticoid receptor (GCR) to treat GWI. These predictions suggest the use of specific monoclonal antibodies or suramin to target interleukin-2 and tumor necrosis factor α , followed by mifepristone to inhibit the GCR. In addition to this putative treatment strategy, there exist a variety of medications that target GWI symptomatology. As pharmaceuticals are promiscuous molecules, binding to multiple sites beyond their intended targets, leading to off-target interactions, it is key to ensure that none of these medications interfere with the proposed treatment avenue. Here, we used the drug docking programs AutoDock 4.2, AutoDock Vina, and Schrödinger's Glide to assess the potential off-target immune and hormone interactions of 43 FDA-approved drugs commonly used to treat GWI symptoms in order to determine their putative polypharmacology and minimize adverse drug effects in a combined pharmaceutical treatment. Several of these FDA-approved drugs were predicted to be novel binders of immune and hormonal targets, suggesting caution for their use in the proposed GWI treatment strategy symptoms.

The polyphenol resveratrol promotes skeletal growth in mice through a sirtuin 1-bone morphogenic protein 2 longevity axis.

BACKGROUND AND PURPOSE: The polyphenol resveratrol (RSV) exists in high quantities in certain foods (e.g. grapes and nuts). However, the capacity of RSV to confer physiological health benefits and a biological mechanism through which this might occur remains unclear. EXPERIMENTAL APPROACH: Aged, RSV-treated (300 mg·kg-1 ·day-1 ) and genetically modified [endothelial NOS (eNOS-/- )] female mice were assessed using histomorphometric and µCT analysis. Alongside in vivo analysis, molecular siRNA knockdown and pharmacological manipulation of eNOS, BMP2 and sirtuin 1 (SIRT1) and functional cellular assays in an osteoblast cell line panel, explored the mechanism through which RSV might impact overall bone volume. KEY RESULTS: RSV promoted osteoblast activity and bone growth in vivo. RSV dose-dependently and simultaneously increased alkaline phosphatase (ALP) and eNOS levels. Similarly, NO-donor treatment increased ALP, runt homology transcription factor 2, BMP2 and stimulated bone formation, whilst eNOS-deficient mice displayed a bone loss phenotype. Moreover, RSV-induced increase in ALP and BMP2 expression was blocked in eNOS-/- osteoblasts and by BMP-inhibitor noggin. The longevity-linked SIRT1 enzyme was positively regulated by RSV and SIRT1 deletion reduced eNOS, BMP2 and ALP. Like eNOS deletion, loss of SIRT1 blocked RSV-induced osteoblast activity; however, SIRT1 levels remained unchanged in eNOS-/- mice, indicating RSV activation of SIRT1 stimulates BMP2 release via eNOS. This signalling axis is supported by decreased SIRT1, eNOS and BMP2 confirmed in old versus young bone. CONCLUSIONS AND IMPLICATIONS: These findings suggest a new mechanism of action in bone remodelling and the ageing skeleton, where RSV positively impacts bone homeostasis via SIRT1 activation of BMP2.

Absceso renal en pediatría: reporte de 2 casos / Kidney abscess in pediatrics: 2 case reports / Abscesso renal em pediatria: relato de dois casos

Resumen Introducción. Los abscesos renales tras una infección urinaria en pediatría no son frecuentes. Reporte de los casos. Se trata de dos niñas con infección urinaria, de 13 y 8 meses, que desarrollan abscesos renales. En ambas, después de un uroanálisis sugestivo de infección urinaria, se inicia manejo empírico con amikacina. El reporte del urocultivo muestra crecimiento de Escherichia coli (E. coli) >100 000 UFC/ml, sensible a dicho antibiótico, con ecografía renal inicial normal en el primer caso y en el segundo con nefromegalia derecha. A pesar del manejo antibiótico persistió la fiebre por más de tres días, por lo que se sospecha una complicación supurada. En el primer caso, la ecografía renal de control refleja imágenes sugestivas de absceso renal, pero en el segundo, a pesar de ecografías seriadas, solo se reportó la nefromegalia, que llevó realizar una tomografía abdominal con contraste para confirmar el diagnóstico. El antibiótico inicial, a pesar de la sensibilidad in vitro, no fue capaz de controlar la formación de abscesos renales. En el primer caso, el proceso infeccioso se controló utilizando amikacina y ceftriaxona, pero en el segundo fue necesario meropenem y amikacina. En ningún momento se alteró la función renal. Es de anotar lo infrecuente que es el absceso renal en niños en nuestra institución, ya que no se ha encontrado ningún caso en varios años. Conclusiones. El absceso renal en pediatría no es frecuente, se desarrolla principalmente tras una infección urinaria. Son necesarios una alta sospecha y un adecuado diagnóstico para orientar su manejo, ya sea solo médico o asociado a drenaje quirúrgico.

Summary Introduction: Renal abscesses are not common in pediatrics after urinary tract infections. Case reports: The two cases involve two 8 and a 13 month old girls with urinary tract infections, who also develop renal abscesses. In both cases, after a urinalysis shows signs of urinary tract infections, empirical management with amikacin is initiated. The uroculture report shows a growth of Escherichia coli (E. coli) >100,000 CFU/ml, sensitive to the given antibiotic, with a normal initial renal ultrasound in the first case and right nephromegaly in the second case. Despite the antibiotic treatment, the fever persisted for more than three days, which is why a suppurative complication is suspected. In the first case, the renal ultrasound from the control suggests the presence of a renal abscess, but in the second case, despite serial ultrasounds, only nephromegaly was reported; therefore, an abdominal tomography with contrast was performed in order to confirm the diagnosis. The initial antibiotic, despite in vitro sensitivity, was not able to control the formation of renal abscesses. In the first case, the infectious process was controlled using amikacin and ceftriaxone, but in the second case, meropenem and amikacin were necessary. At no point in time did the renal function change. It is important to note how infrequent renal abscesses in children are in our institution, given that there have not been any reported cases for several years. Conclusions: Renal abscesses in pediatrics are not frequent; they develop mainly after a urinary tract infection. A high level of suspicion along with an adequate diagnosis is needed in order to guide its management, be it only medical or associated with surgical drainage.

Resumo Introdução. Os abscessos renais após uma infeção urinária em pediatria não são frequentes. Relatório dos casos. Trata-se de duas meninas com infeção urinária, de 13 e 8 meses, que desenvolvem abscessos renais. Em ambas, após uma análise de urina sugestiva de infeção urinária, se inicia manejo empírico com amika-cina. O relatório da cultura de urina mostra crescimento de Escherichia coli (E. coli) >100 000 UFC/ml, sensível a este antibiótico, com ultrassonografia renal inicial normal no primeiro caso e no segundo com nefromegalia direita. Apesar do manejo antibiótico persistiu a febre por mais de três dias, motivo de suspeita de uma complicação supurada. No primeiro caso, a ecografia renal de controle reflete imagens sugestivas de abscesso renal, mas no segundo, apesar de ultrassonografias seriadas, só foi reportada a nefromegalia, que levou a realizar uma tomografia abdominal com contraste para confirmar o diagnóstico. O antibiótico inicial, apesar da sensibilidade in vitro, não foi capaz de controlar a formação de abscessos renais. No primeiro caso, o processo infecioso foi controlado utilizando amikacina e ceftriaxona, mas no segundo foi necessário meropenem e amikacina. Em nenhum momento foi alterada a função renal. Vale anotar que o abscesso renal em crianças em nossa instituição é pouco frequente, já que não há registro de caso algum em vários anos. Conclusões. O abscesso renal em pediatria não é frequente, se desenvolve principalmente após uma infeção urinaria. É necessário uma alta suspeita e um adequado diagnóstico para orientar seu tratamento, seja somente médico ou associado à drenagem cirúrgica.

The ω-3 fatty acid α-linolenic acid extends Caenorhabditis elegans lifespan via NHR-49/PPARα and oxidation to oxylipins.

The dietary intake of ω-3 polyunsaturated fatty acids has been linked to a reduction in the incidence of aging-associated disease including cardiovascular disease and stroke. Additionally, long-lived Caenorhabditis elegans glp-1 germ line-less mutant animals show a number of changes in lipid metabolism including the increased production of the ω-3 fatty acid, α-linolenic acid (ALA). Here, we show that the treatment of C. elegans with ALA produces a dose-dependent increase in lifespan. The increased longevity of the glp-1 mutant animals is known to be dependent on both the NHR-49/PPARα and SKN-1/Nrf2 transcription factors, although the mechanisms involved are incompletely understood. We find that ALA treatment increased the lifespan of wild-type worms and that these effects required both of these transcription factors. Specifically, NHR-49 was activated by ALA to promote the expression of genes involved in the ß-oxidation of lipids, whereas SKN-1 is not directly activated by ALA, but instead, the exposure of ALA to air results in the oxidation of ALA to a group of compounds termed oxylipins. At least one of the oxylipins activates SKN-1 and enhances the increased longevity resulting from ALA treatment. The results show that ω-3 fatty acids inhibit aging and that these effects could reflect the combined effects of the ω-3 fatty acid and the oxylipin metabolites. The benefits of ω-3 fatty acid consumption on human health may similarly involve the production of oxylipins, and differences in oxylipin conversion could account for at least part of the variability found between observational vs. interventional clinical trials.

Local application of a proteasome inhibitor enhances fracture healing in rats.

The ubiquitin/proteasome system plays an important role in regulating the activity of osteoblast precursor cells. Proteasome inhibitors (PSIs) have been shown to stimulate the differentiation of osteoblast precursor cells and to promote bone formation. This raises the possibility that PSIs might be useful for enhancing fracture healing. In this study, we examined the effect of the local administration of PSI on fracture repair in rats. The effects of treatment on the healing of a fractured femur were assessed based on radiographs, micro-computed tomography (µCT) analysis, biomechanical testing, and histological analysis. PSI enhanced osteogenic differentiation in bone marrow- and periosteum-derived mesenchymal progenitor cells in vitro. Moreover, the local administration of PSI in vivo promoted fracture healing in rats, as demonstrated by an increased fracture callus volume in radiographs at 2 weeks post-fracture, and improved radiographic scores. By week 4, PSI treatment had enhanced biomechanical strength and mineral density in the callus as assessed using bending tests, and µCT, respectively. Histological sections demonstrated that PSI treatment accelerated endochondral ossification during the early stages of fracture repair. Although further investigations are necessary to assess its clinical use, the local administration of PSIs might be a novel, and effective therapeutic approach for fracture repair.

A targeted approach for evaluating preclinical activity of botanical extracts for support of bone health.

Using a sequential in vitro/in vivo approach, we tested the ability of botanical extracts to influence biomarkers associated with bone resorption and bone formation. Pomegranate fruit and grape seed extracts were found to exhibit anti-resorptive activity by inhibiting receptor activator of nuclear factor-κB ligand (RANKL) expression in MG-63 cells and to reduce IL-1ß-stimulated calvarial (45)Ca loss. A combination of pomegranate fruit and grape seed extracts were shown to be effective at inhibiting bone loss in ovariectomised rats as demonstrated by standard histomorphometry, biomechanical and bone mineral density measurements. Quercetin and licorice extract exhibited bone formation activity as measured by bone morphogenetic protein-2 (BMP-2) promoter activation, increased expression of BMP-2 mRNA and protein levels, and promotion of bone growth in cultured mouse calvariae. A combination of quercetin and licorice extract demonstrated a potential for increasing bone mineral density in an intact female rat model as compared with controls. The results from this sequential in vitro/in vivo research model yielded botanical extract formulas that demonstrate significant potential benefits for bone health.

Local injection of lovastatin in biodegradable polyurethane scaffolds enhances bone regeneration in a critical-sized segmental defect in rat femora.

Statins, a class of naturally-occurring compounds that inhibit HMG-CoA reductase, are known to increase endogenous bone morphogenetic protein-2 (BMP-2) expression. Local administration of statins has been shown to stimulate fracture repair in in vivo animal experiments. However, the ability of statins to heal more challenging critical-sized defects at the mid-diaphyseal region in long bones has not been investigated. In this study, we examined the potential of injectable lovastatin microparticles combined with biodegradable polyurethane (PUR) scaffolds in preclinical animal models: metaphyseal small plug defects and diaphyseal segmental bone defects in rat femora. Sustained release of lovastatin from the lovastatin microparticles was achieved over 14 days. The released lovastatin was bioactive, as evidenced by its ability to stimulate BMP-2 gene expression in osteoblastic cells. Micro-computed tomography (CT) and histological examinations showed that lovastatin microparticles, injected into PUR scaffolds implanted in femoral plug defects, enhanced new bone formation. Furthermore, bi-weekly multiple injections of lovastatin microparticles into PUR scaffolds implanted in critical-sized femoral segmental defects resulted in increased new bone formation compared to the vehicle control. In addition, bridging of the defect with newly formed bone was observed in four of nine defects in the lovastatin microparticle treatment group, whereas none of the defects in the vehicle group showed bridging. These observations suggest that local delivery of lovastatin combined with PUR scaffold can be an effective approach for treatment of orthopaedic bone defects and that multiple injections of lovastatin may be useful for large defects.

Synergistic effect of exercise and statins on femoral strength in rats.

It is now widely recognized that in order to optimize bone health in the later years, bone healthy behaviors should begin at a young age and continue throughout life. Prescribed orally to lower lipid levels in adults of all ages, statins have also been shown to stimulate bone formation in vitro by promoting bone morphogenic protein-2 (BMP-2) activity and to stimulate bone formation in vivo. Weight bearing exercise is well known to stimulate bone formation through a mechanism whereby mechanical loading is 'sensed' by the mechano-sensors leading to a cascade of events involving the activation of osteoblasts. For individuals with high cholesterol levels, both of these interventions are recommended throughout adult life. Since statins and exercise stimulate bone formation via different mechanisms, we hypothesized that exercise in combination with oral simvastatin synergistically increases bone mineral density and strength. Mature adult female, Sprague Dawley rats were divided into 4 groups: control (n=9), statin only (n=8), exercise only (n=11), and statin plus exercise (n=11). Simvastatin was given to the two groups at a dose of 10 mg/kg/day in standard rat chow for the entire 5 week period. All rats ate the same mass of food. The two exercise groups ran on a treadmill with progressively greater speeds and time, ending on week 5 at 30 m/min for 60 min. After 5 weeks, rats were euthanized, and excised femurs were scanned for areal bone mineral density (BMD) and tested by three point bending to obtain the following performance measures: maximum force (strength), stiffness, and work-to-fracture. Only the group treated with statins and exercise showed a positive effect on the biomechanical performance of the femurs. Compared to controls, this group had increased maximum force, stiffness, moment of inertia, and BMD. Linear regression analysis revealed that the increased performance was related to increased BMD. We conclude that the combination of oral statins and appropriate exercise increases bone strength better than either individual treatment and may provide optimal protection against osteoporosis.

Approaches to treating NF1 tibial pseudarthrosis: consensus from the Children's Tumor Foundation NF1 Bone Abnormalities Consortium.

BACKGROUND: Neurofibromatosis 1 (NF1) is an autosomal dominant disorder with various skeletal abnormalities occurring as part of a complex phenotype. Tibial dysplasia, which typically presents as anterolateral bowing of the leg with subsequent fracture and nonunion (pseudarthrosis), is a serious but infrequent osseous manifestation of NF1. Over the past several years, results from clinical and experimental studies have advanced our knowledge of the role of NF1 in bone. On the basis of current knowledge, we propose a number of concepts to consider as a theoretical approach to the optimal management of tibial pseudarthrosis. METHODS: A literature review for both clinical treatment and preclinical models for tibial dysplasia in NF1 was performed. Concepts were discussed and developed by experts who participated in the Children's Tumor Foundation sponsored International Bone Abnormalities Consortium meeting in 2011. RESULTS: Concepts for a theoretical approach to treating tibial pseudarthrosis include: bone fixation appropriate to achieve stability in any given case; debridement of the "fibrous pseudarthrosis tissue" between the bone segments associated with the pseudarthrosis; creating a healthy vascular bed for bone repair; promoting osteogenesis; controlling overactive bone resorption (catabolism); prevention of recurrence of the "fibrous pseudarthrosis tissue"; and achievement of long-term bone health to prevent recurrence. CONCLUSIONS: Clinical trials are needed to assess effectiveness of the wide variation of surgical and pharmacologic approaches currently in practice for the treatment of tibial pseudarthrosis in NF1. LEVEL OF EVIDENCE: Level V, expert opinion.

Characterization of synthesized NANO-encapsulated drug for bone loss on hind limb suspension rat model by NMR and micro-CT.

A formulation of nano-encapsulated enantiomer of (+) promethazine with desired release rate has been synthesized for establish a localized drug delivery system. It was tested on a hind limb suspension (HLS) disuse rat model, and by using a non-destructive Nuclear Magnetic Resonance (NMR) relaxation technique, and micro computed tomography (Micro-CT) analysis technique to qualitatively evaluate the effectiveness of the new bone formations as well as to compare the current commercial anti-bone loss drug Alendeonate. Our studies suggest that nano-encapsulated (+) promethazine in controlled release formulations conjugating bone-targeting functional groups are effective in promoting bone growth in a disuse rat model.

Design and assessment of a wrapped cylindrical Ca-P AZ31 Mg alloy for critical-size ulna defect repair.

Recently, magnesium has been investigated as a promising bioresorbable orthopedic biomaterial. Its mechanical properties are very similar to natural bone, making it appropriate for load-bearing orthopedic fracture repair applications. However, significant hurdles remain regarding the design of practical implants and methods to control degradation and enhance biocompatibility. Although attempts have been made to hinder magnesium's rapid corrosion via alloying and coating, these studies have used solid monoliths. In an effort to reduce the amount of alloy used for implantation in a shape that mimics cortical bone shape, this study used a thin sheet of Mg AZ31 which was rolled into hollow cylindrical scaffolds. The scaffold was coated with different amounts of Ca-P; this implant demonstrated slowed corrosion in simulated body fluid (SBF) as well as enhanced biocompatibility for mesenchymal stem cells (MSC). In vivo implantation of magnesium alloy scaffold adjacent to the rat femur showed significant biointegration with further deposition of complex Mg-Ca phosphates/carbonates typical of natural bone. Finally, the implant was placed in a critical-size ulna defect in live rabbits, which lead to radiographic union and partial restoration of biomechanical strength in the defect. This study demonstrated that a thin sheet of coated Mg alloy that was spirally wrapped wound be a promising orthopedic biomaterial for bone repair.

Mechanisms underlying the bioindicator notion: spatial association between individual sexual performance and community diversity.

The bioindicator notion is an appealing concept that has received more support in applied than in basic ecology, mostly due to the difficulty in deriving general ecological rules applicable to all target organisms. However, recognizing the mechanisms that determine the association between a particular species and the well-being of many other species is important for understanding the functioning of ecosystems and the relationship among different biological levels. We examined here the processes at the individual level that cause an association between species performance and biodiversity value, by analyzing attributes that can be studied in a variety of animals with sexual reproduction, namely breeding site selection and condition-dependent sexual signals. Our study model was the Capercaillie, an indicator of forest functioning and diversity, and the associated bird community, used here as a surrogate of broader forest biodiversity. At a regional scale Capercaillie occurrence was not associated with the most diverse forest patches, but at the scale of male spring territories the sexual display grounds (arenas) were located in the oldest and less disturbed forest portions, which also hosted the richest local bird communities. Social mechanisms and conspecific cueing likely concurred with habitat-driven processes in determining the long-term persistence of traditional display grounds, which were appealing to many other species because of their structural composition. Characteristics of male vocal display that honestly advertize male quality (low frequencies and rapid song rates) were significantly correlated with high diversity values, resulting in a spatial association between individual and community performances. Costly or risky activities such as reproductive or social behaviors, which more than other attributes match gradients in habitat quality, are therefore contributing to functionally connect individuals with ecosystem health.