333 research outputs found
Antibacterial evaluation of synthetic thiazole compounds in vitro and in vivo in a methicillin-resistant staphylococcus aureus (MRSA) skin infection mouse model
The emergence of community-associated methicillin-resistant Staphylococcus aureus (MRSA), including strains resistant to current antibiotics, has contributed to an increase in the number of skin infections reported in humans in recent years. New therapeutic options are needed to counter this public health challenge. The aim of the present study was to examine the potential of thiazole compounds synthesized by our research group to be used topically to treat MRSA skin and wound infections. The broth microdilution method confirmed that the lead thiazole compound and four analogues are capable of inhibiting MRSA growth at concentrations as low as 1.3 μg/mL. Additionally, three compounds exhibited a synergistic relationship when combined with the topical antibiotic mupirocin against MRSA in vitro via the checkerboard assay. Thus the thiazole compounds have potential to be used alone or in combination with mupirocin against MRSA. When tested against human keratinocytes, four derivatives of the lead compound demonstrated an improved toxicity profile (were found to be non-toxic up to a concentration of 20 μg/mL). Utilizing a murine skin infection model, we confirmed that the lead compound and three analogues exhibited potent antimicrobial activity in vivo, with similar capability as the antibiotic mupirocin, as they reduced the burden of MRSA present in skin wounds by more than 90%. Taken altogether, the present study provides important evidence that these thiazole compounds warrant further investigation for development as novel topical antimicrobials to treat MRSA skin infections. © 2015 Mohammad et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Recommended from our members
Urinary Tubular Injury Biomarkers Are Associated With ESRD and Death in the REGARDS Study.
IntroductionUrinary neutrophil gelatinase-associated lipocalin (uNGAL) and urinary kidney injury molecule-1 (uKIM-1) are established markers of subclinical acute kidney injury. In persons with reduced estimated glomerular filtration rate (eGFR) and albuminuria who are at high risk for end-stage renal disease (ESRD) and death, the associations of these urinary markers with incident ESRD or death is an area of active investigation.MethodsAmong 1472 black and white participants from the REasons for Geographic and Racial Differences in Stroke (REGARDS) study with eGFR ≤60 ml/min per 1.73 m2 (Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI] cystatin, 2012) and albumin-to-creatinine ratio (ACR) ≥30 mg/g, we evaluated the associations of baseline uNGAL and uKIM-1 with progression to ESRD and all-cause death. Cox models were sequentially adjusted for urinary creatinine, traditional risk factors, C-reactive protein, ACR, and eGFR.ResultsThere were 257 ESRD events and 819 deaths over a median follow-up of 5.7 and 6.5 years, respectively. In demographic adjusted models, higher levels of uNGAL were associated with increased risk of ESRD and death, but these associations were attenuated in fully adjusted models including baseline eGFR for both ESRD (hazard ratio [HR] = 1.06 per doubling, 95% confidence interval [CI] 0.98-1.14) and death (HR = 1.04, 95% CI = 1.00-1.08). Higher levels of uKIM-1 were associated with increased risk of ESRD and death in demographic-adjusted models, and although attenuated in fully adjusted models, remained statistically significant for both ESRD (HR = 1.24 per doubling, 95% CI = 1.08-1.42) and death (HR = 1.10, 95% CI =1.03-1.19).ConclusionIn this cohort of high-risk patients with baseline eGFR ≤60 ml/min per 1.73 m2 and albuminuria, renal tubular injury is associated with higher mortality and progression to ESRD. Further studies are necessary to investigate the mechanism underlying this increased risk
Inhibition of Vascular Endothelial Growth Factor Manipulates Follicles in Beef Females
Vascular Endothelial Growth Factor (VEGF) is produced by cells surrounding the egg in the follicle. If VEGF is inhibited, ovulation does not occur. Understanding how VEGF regulates follicle development may allow for manipulation of estrous cycles. In previous studies in our laboratory, blocking the actions of VEGF decreased activation of early stage follicles in neonatal rat ovary cultures. Therefore, we hypothesized inhibition of VEGF actions would also inhibit follicle activation in bovine ovarian cortical cultures. Inhibition of VEGF did inhibit follicle progression, thus regulation of VEGF may be a way to manipulate follicle development and more accurately time ovulation
Inhibition of Vascular Endothelial Growth Factor Manipulates Follicles in Beef Females
Vascular Endothelial Growth Factor (VEGF) is produced by cells surrounding the egg in the follicle. If VEGF is inhibited, ovulation does not occur. Understanding how VEGF regulates follicle development may allow for manipulation of estrous cycles. In previous studies in our laboratory, blocking the actions of VEGF decreased activation of early stage follicles in neonatal rat ovary cultures. Therefore, we hypothesized inhibition of VEGF actions would also inhibit follicle activation in bovine ovarian cortical cultures. Inhibition of VEGF did inhibit follicle progression, thus regulation of VEGF may be a way to manipulate follicle development and more accurately time ovulation
Synthesis of Triphenylethylene Bisphenols as Aromatase Inhibitors that Also Modulate Estrogen Receptors
A series of triphenylethylene bisphenol analogues of the selective estrogen receptor modulator (SERM) tamoxifen were synthesized and evaluated for their abilities to inhibit aromatase, bind to estrogen receptor α (ER-α) and estrogen receptor β (ER-β), and antagonize the activity of β-estradiol in MCF-7 human breast cancer cells. The long-range goal has been to create dual aromatase inhibitor (AI)/selective estrogen receptor modulators (SERMs). The hypothesis is that in normal tissue the estrogenic SERM activity of a dual AI/SERM could attenuate the undesired effects stemming from global estrogen depletion caused by the AI activity of a dual AI/SERM, while in breast cancer tissue the antiestrogenic SERM activity of a dual AI/SERM could act synergistically with AI activity to enhance the antiproliferative effect. The potent aromatase inhibitory activities and high ER-α and ER-β binding affinities of several of the resulting analogues, together with the facts that they antagonize β-estradiol in a functional assay in MCF-7 human breast cancer cells and they have no E/Z isomers, support their further development in order to obtain dual AI/SERM agents for breast cancer treatment
A new Suzuki synthesis of triphenylethylenes that inhibit aromatase and bind to estrogen receptors α and β
The design and synthesis of dual aromatase inhibitors/selective estrogen receptor modulators (AI/SERMs) is an attractive strategy for the discovery of new breast cancer therapeutic agents. Previous efforts led to the preparation of norendoxifen (4) derivatives with dual aromatase inhibitory activity and estrogen receptor binding activity. In the present study, some of the structural features of the potent AI letrozole were incorporated into the lead compound (norendoxifen) to afford a series of new dual AI/SERM agents based on a symmetrical diphenylmethylene substructure that eliminates the problem of E,Z isomerization encountered with norendoxifen-based AI/SERMs. Compound 12d had good aromatase inhibitory activity (IC50 = 62.2 nM) while also exhibiting good binding activity to both ER-α (EC50 = 72.1 nM) and ER-β (EC50 = 70.8 nM). In addition, a new synthesis was devised for the preparation of norendoxifen and its analogues through a bis-Suzuki coupling strategy.
Venous thromboembolism research priorities: A scientific statement from the American Heart Association and the International Society on Thrombosis and Haemostasis
Venous thromboembolism (VTE) is a major cause of morbidity and mortality. The impact of the Surgeon General’s Call to Action in 2008 has been lower than expected given the public health impact of this disease. This scientific statement highlights future research priorities in VTE, developed by experts and a crowdsourcing survey across 16 scientific organizations. At the fundamental research level (T0), researchers need to identify pathobiologic causative mechanisms for the 50% of patients with unprovoked VTE and better understand mechanisms that differentiate hemostasis from thrombosis. At the human level (T1), new methods for diagnosing, treating, and preventing VTE will allow tailoring of diagnostic and therapeutic approaches to individuals. At the patient level (T2), research efforts are required to understand how foundational evidence impacts care of patients (eg, biomarkers). New treatments, such as catheter‐based therapies, require further testing to identify which patients are most likely to experience benefit. At the practice level (T3), translating evidence into practice remains challenging. Areas of overuse and underuse will require evidence‐based tools to improve care delivery. At the community and population level (T4), public awareness campaigns need thorough impact assessment. Large population‐based cohort studies can elucidate the biologic and environmental underpinings of VTE and its complications. To achieve these goals, funding agencies and training programs must support a new generation of scientists and clinicians who work in multidisciplinary teams to solve the pressing public health problem of VTE.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156163/2/rth212373_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156163/1/rth212373.pd
Poisson structures for reduced non-holonomic systems
Borisov, Mamaev and Kilin have recently found certain Poisson structures with
respect to which the reduced and rescaled systems of certain non-holonomic
problems, involving rolling bodies without slipping, become Hamiltonian, the
Hamiltonian function being the reduced energy. We study further the algebraic
origin of these Poisson structures, showing that they are of rank two and
therefore the mentioned rescaling is not necessary. We show that they are
determined, up to a non-vanishing factor function, by the existence of a system
of first-order differential equations providing two integrals of motion. We
generalize the form of that Poisson structures and extend their domain of
definition. We apply the theory to the rolling disk, the Routh's sphere, the
ball rolling on a surface of revolution, and its special case of a ball rolling
inside a cylinder.Comment: 22 page
PHYSIOLOGY AND ENDOCRINOLOGY SYMPOSIUM: How single nucleotide polymorphism chips will advance our knowledge of factors controlling puberty and aid in selecting replacement beef females
The promise of genomic selection is accurate prediction of the genetic potential of animals from their genotypes. Simple DNA tests might replace low-accuracy predictions for expensive or lowly heritable measures of puberty and fertility based on performance and pedigree. Knowing with some certainty which DNA variants (e.g., SNP) affect puberty and fertility is the best way to fulfill the promise. Several SNP from the BovineSNP50 assay have tentatively been associated with reproductive traits including age at puberty, antral follicle count, and pregnancy observed on different sets of heifers. However, sample sizes are too small and SNP density is too sparse to definitively determine genomic regions harboring causal variants affecting reproductive success. Additionally, associations between individual SNP and similar phenotypes are inconsistent across data sets, and genomic predictions do not appear to be globally applicable to cattle of different breeds. Discrepancies may be a result of different QTL segregating in the sampled populations, differences in linkage disequilibrium (LD) patterns such that the same SNP are not correlated with the same QTL, and spurious correlations with phenotype. Several approaches can be used independently or in combination to improve detection of genomic factors affecting heifer puberty and fertility. Larger samples and denser SNP will increase power to detect real associations with SNP having more consistent LD with underlying QTL. Meta- analysis combining results from different studies can also be used to effectively increase sample size. High-density genotyping with heifers pooled by pregnancy status or early and late puberty can be a cost-effective means to sample large numbers. Networks of genes, implicated by associations with multiple traits correlated with puberty and fertility, could provide insight into the complex nature of these traits, especially if corroborated by functional annotation, established gene interaction pathways, and transcript expression. Example analyses are provided to demonstrate how integrating information about gene function and regulation with statistical associations from whole-genome SNP genotyping assays might enhance knowledge of genomic mechanisms affecting puberty and fertility, enabling reliable DNA tests to guide heifer selection decisions
Multiple uncontrolled conditions and blood pressure medication intensification: an observational study
Abstract Background Multiple uncontrolled medical conditions may act as competing demands for clinical decision making. We hypothesized that multiple uncontrolled cardiovascular risk factors would decrease blood pressure (BP) medication intensification among uncontrolled hypertensive patients. Methods We observed 946 encounters at two VA primary care clinics from May through August 2006. After each encounter, clinicians recorded BP medication intensification (BP medication was added or titrated). Demographic, clinical, and laboratory information were collected from the medical record. We examined BP medication intensification by presence and control of diabetes and/or hyperlipidemia. 'Uncontrolled' was defined as hemoglobin A1c ≥ for diabetes, BP ≥ 140/90 mmHg (≥ 130/80 mmHg if diabetes present) for hypertension, and low density lipoprotein cholesterol (LDL-c) ≥ 130 mg/dl (≥ 100 mg/dl if diabetes present) for hyperlipidemia. Hierarchical regression models accounted for patient clustering and adjusted medication intensification for age, systolic BP, and number of medications. Results Among 387 patients with uncontrolled hypertension, 51.4% had diabetes (25.3% were uncontrolled) and 73.4% had hyperlipidemia (22.7% were uncontrolled). The BP medication intensification rate was 34.9% overall, but higher in individuals with uncontrolled diabetes and uncontrolled hyperlipidemia: 52.8% overall and 70.6% if systolic BP ≥ 10 mmHg above goal. Intensification rates were lowest if diabetes or hyperlipidemia were controlled, lower than if diabetes or hyperlipidemia were not present. Multivariable adjustment yielded similar results. Conclusions The presence of uncontrolled diabetes and hyperlipidemia was associated with more guideline-concordant hypertension care, particularly if BP was far from goal. Efforts to understand and improve BP medication intensification in patients with controlled diabetes and/or hyperlipidemia are warranted.http://deepblue.lib.umich.edu/bitstream/2027.42/78266/1/1748-5908-5-55.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78266/2/1748-5908-5-55.pdfPeer Reviewe
- …