Oral subchronic toxicity study and genetic toxicity evaluation of mitoquinone mesylate.

Mitochondrial dysfunction and excessive reactive oxygen species production contributes to the pathophysiology of aging. Coenzyme Q10 is thought to protect mitochondria from oxidative damage; thus, mitoquinone was developed as mitochondria-targeted analogue with similar antioxidant activity. Mitoquinone is the oxidized form of mitoquinol. Mitoquinone/mitoquinol mesylate has been proposed as a food ingredient. As part of the safety analysis, we performed genotoxicity assays and a 39-week toxicity study to determine overall toxicity potential. Mitoquinone mesylate showed no evidence of genotoxic potential in two in vitro assays, bacterial reverse mutation and human lymphocyte chromosome aberration, nor in the in vivo micronucleus test in rats. In the 39-week study in dogs, there were no findings observed, which were considered to represent adverse systemic toxicity; therefore, the high dose level (40 mg/kg/day) was considered the NOAEL. The principal findings in this study were fecal disturbances and vomiting. These findings were considered to be due to a local, possibly irritant effect of the test substance on the gastrointestinal tract and were not considered adverse as there were no impacts on clinical or histopathology. This highest dose exceeds the expected daily human intake more than 100-fold. Data from well-designed clinical trials actively collecting safety endpoints corroborate that 20 mg/day can be safely consumed and is not likely to result in significant gastrointestinal complaints. These results support the conclusion that the use of mitoquinone/mitoquinol mesylate as a food ingredient is safe.

Protracted transmission and persistence of ST80 vancomycin-resistant Enterococcus faecium clonal complex types CT2933, CT2932 and CT1916 in a large Irish hospital: a 39-month WGS study.

BACKGROUND: Vancomycin-resistant Enterococcus faecium (VREfm) are significant nosocomial pathogens. Sequence type (ST)80 vanA-encoding VREfm predominate in Irish hospitals, but their transmission is poorly understood. AIMS: To investigate transmission and persistence of predominant complex type (CT) VREfm in two wards of an Irish hospital (H1) using whole-genome sequencing, and their intra- and inter-hospital dissemination. METHODS: Rectal screening (N=330, September 2019-December 2022) and environmental (N=48, November 2022-December 2022) E. faecium were investigated. Isolate relatedness was assessed by core-genome multilocus sequence typing (cgMLST) and core-genome single nucleotide polymorphism (cgSNP) analysis. Likely transmission chains were identified using SeqTrack (https://graphsnp.fordelab.com/graphsnp) using cgSNP data and recovery location. Well-characterised E. faecium (N=908) from seven Irish hospitals including H1 (June 2017-July 2022) were also investigated. FINDINGS: Conventional MLST assigned isolates to nine STs (ST80, 82%). cgMLST identified three predominant ST80 CTs (CT2933, CT2932 and CT1916) (55% of isolates) of related isolates (≤20 allelic differences). cgSNP analysis differentiated these CTs into multiple distinct closely related genomic clusters (≤10 cgSNPs). Parisimonious network construction identified 55 likely inter- and intra-ward transmissions with epidemiological support between patients ≤30 days involving 73 isolates (≤10 cgSNPs) from seven genomic clusters. Numerous other likely transmissions over longer time periods without evident epidemiological links were identified, suggesting persistence and unidentified reservoirs contribute to dissemination. The three CTs predominated among E. faecium (N=1,286) in seven hospitals, highlighting inter-hospital spread without known epidemiological links. CONCLUSION: This study revealed the long-term intra- and inter-hospital dominance of three major CT ST80 VREfm lineages, widespread transmission and persistence, implicating unidentified reservoirs.

The AusTraits plant dictionary.

Traits with intuitive names, a clear scope and explicit description are essential for all trait databases. The lack of unified, comprehensive, and machine-readable plant trait definitions limits the utility of trait databases, including reanalysis of data from a single database, or analyses that integrate data across multiple databases. Both can only occur if researchers are confident the trait concepts are consistent within and across sources. Here we describe the AusTraits Plant Dictionary (APD), a new data source of terms that extends the trait definitions included in a recent trait database, AusTraits. The development process of the APD included three steps: review and formalisation of the scope of each trait and the accompanying trait description; addition of trait metadata; and publication in both human and machine-readable forms. Trait definitions include keywords, references, and links to related trait concepts in other databases, enabling integration of AusTraits with other sources. The APD will both improve the usability of AusTraits and foster the integration of trait data across global and regional plant trait databases.

miRNA as a Biomarker for the Early Detection of Colorectal Cancer.

MicroRNAs (miRNAs) are short, non-coding RNA segments that can be detected in a variety of clinical samples, including serum, stool, and urine. While miRNAs were initially known for their effect on post-translational gene expression, the last decade of research has shown them to be promising biomarkers for the detection of many types of cancer. This paper explores the use of miRNA detection as a tool for colorectal cancer (CRC) screening. We discuss the current state of miRNA detection, compare it to the existing CRC screening tools, and highlight the advantages and drawbacks of this approach from a clinical and logistical perspective. Our research finds that miRNA-based tests for CRC show great potential, but that widespread clinical adoption will be conditional on future research overcoming key hurdles.

Leaf relative water content at 50% stomatal conductance measured by noninvasive NMR is linked to climate of origin in nine species of eucalypt.

Stomata are the gatekeepers of plant water use and must quickly respond to changes in plant water status to ensure plant survival under fluctuating environmental conditions. The mechanism for their closure is highly sensitive to disturbances in leaf water status, which makes isolating their response to declining water content difficult to characterise and to compare responses among species. Using a small-scale non-destructive nuclear magnetic resonance spectrometer as a leaf water content sensor, we measure the stomatal response to rapid induction of water deficit in the leaves of nine species of eucalypt from contrasting climates. We found a strong linear correlation between relative water content at 50% stomatal conductance (RWCgs50 ) and mean annual temperature at the climate of origin of each species. We also show evidence for stomata to maintain control over water loss well below turgor loss point in species adapted to warmer climates and secondary increases in stomatal conductance despite declining water content. We propose that RWCgs50 is a promising trait to guide future investigations comparing stomatal responses to water deficit. It may provide a useful phenotyping trait to delineate tolerance and adaption to hot temperatures and high leaf-to-air vapour pressure deficits.

Photographs as an essential biodiversity resource: drivers of gaps in the vascular plant photographic record.

The photographic record is increasingly becoming an important biodiversity resource for primary research and conservation monitoring. However, globally, there are important gaps in this record even in relatively well-researched floras. To quantify the gaps in the Australian native vascular plant photographic record, we systematically surveyed 33 sources of well-curated species photographs, assembling a list of species with accessible and verifiable photographs, as well as the species for which this search failed. Of 21 077 Australian native species, 3715 lack a verifiable photograph across our 33 surveyed resources. There are three major geographic hotspots of unphotographed species in Australia, all far from current population centres. Many unphotographed species are small in stature or uncharismatic, and many are also recently described. The large number of recently described species without accessible photographs was surprising. There are longstanding efforts in Australia to organise the plant photographic record, but in the absence of a global consensus to treat photographs as an essential biodiversity resource, this has not become common practice. Many recently described species are small-range endemics and some have special conservation status. Completing the botanical photographic record across the globe will facilitate a virtuous feedback loop of more efficient identification, monitoring and conservation.

Phylodynamic signatures in the emergence of community-associated MRSA.

Community-associated, methicillin-resistant Staphylococcus aureus (MRSA) lineages have emerged in many geographically distinct regions around the world during the past 30 y. Here, we apply consistent phylodynamic methods across multiple community-associated MRSA lineages to describe and contrast their patterns of emergence and dissemination. We generated whole-genome sequencing data for the Australian sequence type (ST) ST93-MRSA-IV from remote communities in Far North Queensland and Papua New Guinea, and the Bengal Bay ST772-MRSA-V clone from metropolitan communities in Pakistan. Increases in the effective reproduction number (Re) and sustained transmission (Re > 1) coincided with spread of progenitor methicillin-susceptible S. aureus (MSSA) in remote northern Australian populations, dissemination of the ST93-MRSA-IV genotype into population centers on the Australian East Coast, and subsequent importation into the highlands of Papua New Guinea and Far North Queensland. Applying the same phylodynamic methods to existing lineage datasets, we identified common signatures of epidemic growth in the emergence and epidemiological trajectory of community-associated S. aureus lineages from America, Asia, Australasia, and Europe. Surges in Re were observed at the divergence of antibiotic-resistant strains, coinciding with their establishment in regional population centers. Epidemic growth was also observed among drug-resistant MSSA clades in Africa and northern Australia. Our data suggest that the emergence of community-associated MRSA in the late 20th century was driven by a combination of antibiotic-resistant genotypes and host epidemiology, leading to abrupt changes in lineage-wide transmission dynamics and sustained transmission in regional population centers.

Genetically diverse mouse platform to xenograft cancer cells.

The lack of genetically diverse preclinical animal models in basic biology and efficacy testing has been cited as a potential cause of failure in clinical trials. We developed and characterized five diverse RAG1 null mouse strains as models that allow xenografts to grow. In these strains, we characterized the growth of breast cancer, leukemia and glioma cell lines. We found a wide range of growth characteristics that were far more dependent on strain than tumor type. For the breast cancer cell line, we characterized the spectrum of xenograft/tumor growth at structural, histological, cellular and molecular levels across each strain, and found that each strain captures unique structural components of the stroma. Furthermore, we showed that the increase in tumor-infiltrating myeloid CD45+ cells and the amount of circulating cytokine IL-6 and chemokine KC (also known as CXCL1) is associated with a higher tumor size in different strains. This resource is available to study established human xenografts, as well as difficult-to-xenograft tumors and growth of hematopoietic stems cells, and to decipher the role of myeloid cells in the development of spontaneous cancers.

Development and validation of monoclonal antibodies specific for Candida albicans Als2, Als9-1, and Als9-2.

Fungal agglutinin-like sequence (Als) cell-surface glycoproteins, best characterized in Candida albicans, mediate adhesive and aggregative interactions with host cells, other microbes, and abiotic surfaces. Monoclonal antibodies (MAbs) specific for each C. albicans Als protein are valuable reagents for gaining insight into Als protein localization and function. This manuscript describes development and validation of MAbs specific for C. albicans Als2, as well as for C. albicans Als9-1 and Als9-2, two protein variants produced from the ALS9 locus. Native C. albicans ALS9 expression levels were not sufficiently high to produce detectable Als9 protein on the wild-type cell surface so MAb validation required production of overexpression strains, each featuring one of the two ALS9 alleles. An anti-Als2 MAb was raised against an N-glycosylated form of the protein immunogen, as well as an Endoglycosidase H-treated immunogen. The MAb raised against the N-glycosylated immunogen proved superior and immunolabeled C. albicans yeast cells and germ tubes, and the surface of Candida dubliniensis and Candida tropicalis yeasts. Als2 was visible on C. albicans yeast cells recovered from a murine model of oral candidiasis, demonstrating Als2 production both in vivo and in vitro. These new MAbs add to the collection of anti-Als MAbs that are powerful tools to better understand the role of Als proteins in C. albicans biology and pathogenesis.

Development and Use of a Monoclonal Antibody Specific for the Candida albicans Cell-Surface Protein Hwp1.

The Candida albicans cell-surface protein Hwp1 functions in adhesion to the host and in biofilm formation. A peptide from the Gln-Pro-rich adhesive domain of Hwp1 was used to raise monoclonal antibody (MAb) 2-E8. MAb 2-E8 specificity for Hwp1 was demonstrated using a hwp1/hwp1 C. albicans isolate and strains that expressed at least one HWP1 allele. Immunofluorescence and atomic force microscopy experiments using MAb 2-E8 confirmed C. albicans germ-tube-specific detection of the Hwp1 protein. MAb 2-E8 also immunolabeled the tips of some Candida dubliniensis germ tubes grown under conditions that maximized HWP1 expression. The phylogeny of HWP1 and closely related genes suggested that the Gln-Pro-rich adhesive domain was unique to C. albicans and C. dubliniensis focusing the utility of MAb 2-E8 on these species. This new reagent can be used to address unanswered questions about Hwp1 and its interactions with other proteins in the context of C. albicans biology and pathogenesis.

ALS1 Deletion Increases the Proportion of Small Cells in a Candida albicans Culture Population: Hypothesizing a Novel Role for Als1.

Candida albicans Als1 is a large cell-surface glycoprotein most often discussed for its role in mediating ligand-binding and aggregative interactions. Relative to a wild-type control, deletion of ALS1 produced a strain that showed delayed germ-tube formation and delayed disease progression in a murine model of disseminated candidiasis. Populations of Δals1/Δals1 cultured cells had a higher proportion of smaller cells compared to wild-type or ALS1 reintegrant control cultures. The goal of this work was to investigate whether this difference in cell-size distributions was responsible for delayed germ-tube formation and delayed disease progression. Flow cytometry was used to select populations of wild-type and Δals1/Δals1 cells with varied cell-size distributions. Delayed germ-tube formation was demonstrated for small cells sorted from a wild-type (ALS1/ALS1) culture population. Large cells sorted from a Δals1/Δals1 culture formed germ tubes as quickly as the wild-type control demonstrating clearly that the Δals1/Δals1 germ-tube formation delays were attributable to cell size. In vivo, smaller-sized cells of the wild-type control showed fewer colony-forming units (cfu) per gram of kidney tissue and less-severe histopathology lesions compared to larger cells of the same strain. The Δals1/Δals1 strain showed reduced cfu/g of kidney tissue and less-severe lesions compared to the wild-type control. However, isolation and testing of the larger cells from the Δals1/Δals1 population increased cfu/g of tissue and showed increased lesion severity compared to the overall mutant cell population. In vivo hypha lengths from the large, sorted Δals1/Δals1 cells were comparable to those for the wild-type control strain. These results demonstrated that a large share of the Δals1/Δals1 in-vivo phenotype was attributable to cell size. Collectively, the data suggest a role for Als1 in C. albicans cell size homeostasis, a novel hypothesis for further exploration.

Genomic analysis of 600 vancomycin-resistant Enterococcus faecium reveals a high prevalence of ST80 and spread of similar vanA regions via IS1216E and plasmid transfer in diverse genetic lineages in Ireland.

BACKGROUND: Vancomycin-resistant Enterococcus faecium (VREfm) cause a wide range of hospital infections. Ireland has had one of the highest invasive VREfm infection rates in Europe over the last decade, yet little is known about Irish VREfm. OBJECTIVES: To investigate the population structure of Irish VREfm, explore diversity by analysing the vanA transposon region and compare Irish, Danish and global isolates. METHODS: E. faecium (n = 648) from five Irish hospitals were investigated, including VREfm [547 rectal screening and 53 bloodstream infection (BSI)] isolates and 48 vancomycin-susceptible (VSEfm) BSI isolates recovered between June 2017 and December 2019. WGS and core-genome MLST (cgMLST) were used to assess population structure. Genetic environments surrounding vanA were resolved by hybrid assembly of short-read (Illumina) and long-read (Oxford Nanopore Technologies) sequences. RESULTS: All isolates belonged to hospital-adapted clade A1 and the majority (435/648) belonged to MLST ST80. The population structure was highly polyclonal; cgMLST segregated 603/648 isolates into 51 clusters containing mixtures of screening and BSI isolates, isolates from different hospitals, and VREfm and VSEfm. Isolates within clusters were closely related (mean average ≤16 allelic differences). The majority (96.5%) of VREfm harboured highly similar vanA regions located on circular or linear plasmids with multiple IS1216E insertions, variable organization of vanA operon genes and 78.6% harboured a truncated tnpA transposase. Comparison of 648 Irish isolates with 846 global E. faecium from 30 countries using cgMLST revealed little overlap. CONCLUSIONS: Irish VREfm are polyclonal, yet harbour a characteristic plasmid-located vanA region with multiple IS1216E insertions that may facilitate spread.

Physician Incentive Compensation Plans in Academic Medical Centers: The Imperative to Prioritize Value.

The emphasis on clinical volume in physician compensation plans has diminished professional vitality in academic medical centers and increased the cost of health care. Physician incentive compensation plans that focus on clinical volume can distort clinical encounters and fail to incorporate the professionalism and intrinsic motivators of clinicians. We assert herein that physician incentive compensation plans should reward clinical value (quality/cost) rather than clinical volume. The recommended change is compelled by the tenets of medical professionalism, the need to cultivate meaning in clinical practice, and the urgent financial and moral imperatives to improve health outcomes and reduce cost. The design of physician incentive compensation plans should incorporate accurate and valid measures of quality and cost, behavioral economic considerations, transparency and equity, prospective assessment of the impact on key outcomes, and flexible elements that encourage innovation and preserve fidelity to unique practice circumstances. Physicians should be recognized in compensation plans for enhancing the value of care, inspiring and educating the future clinical workforce, and improving public health through discovery.

Exploring the evolution and epidemiology of European CC1-MRSA-IV: tracking a multidrug-resistant community-associated meticillin-resistant Staphylococcus aureus clone.

This study investigated the evolution and epidemiology of the community-associated and multidrug-resistant Staphylococcus aureus clone European CC1-MRSA-IV. Whole-genome sequences were obtained for 194 European CC1-MRSA-IV isolates (189 of human and 5 of animal origin) from 12 countries, and 10 meticillin-susceptible precursors (from North-Eastern Romania; all of human origin) of the clone. Phylogenetic analysis was performed using a maximum-likelihood approach, a time-measured phylogeny was reconstructed using Bayesian analysis, and in silico microarray genotyping was performed to identify resistance, virulence-associated and SCCmec (staphylococcal cassette chromosome mec) genes. Isolates were typically sequence type 1 (190/204) and spa type t127 (183/204). Bayesian analysis indicated that European CC1-MRSA-IV emerged in approximately 1995 before undergoing rapid expansion in the late 1990s and 2000s, while spreading throughout Europe and into the Middle East. Phylogenetic analysis revealed an unstructured meticillin-resistant S. aureus (MRSA) population, lacking significant geographical or temporal clusters. The MRSA were genotypically multidrug-resistant, consistently encoded seh, and intermittently (34/194) encoded an undisrupted hlb gene with concomitant absence of the lysogenic phage-encoded genes sak and scn. All MRSA also harboured a characteristic ~5350 nt insertion in SCCmec adjacent to orfX. Detailed demographic data from Denmark showed that there, the clone is typically (25/35) found in the community, and often (10/35) among individuals with links to South-Eastern Europe. This study elucidated the evolution and epidemiology of European CC1-MRSA-IV, which emerged from a meticillin-susceptible lineage prevalent in North-Eastern Romania before disseminating rapidly throughout Europe.

How to Launch and Continually Enhance an Effective Medical Campus Faculty Development Program: Steps for Implementation and Lessons Learned.

PURPOSE: Drawing on the decade of experience of Boston University Medical Campus' Faculty Development Office, this paper reports strategies used to launch and continually improve faculty development programming within an academic health sciences campus. PATIENTS AND METHODS: The authors explain the steps that Boston University Medical Campus took to institute their set of faculty development programs, including an overview of resources on how to periodically conduct needs assessments, engage key institutional stakeholders, design and evaluate an array of programming to meet the needs of a diverse faculty, and institute real-time program modifications. RESULTS: In a step-by-step guide, and by highlighting vital lessons learned, the authors describe a process by which biomedical educators can create and sustain a robust faculty development office within their own institutions. CONCLUSION: This paper identifies steps to launch and improve faculty development program. Faculty development programs should be expanded to support faculty in academic medical centers.

Sylvatic Canine Morbillivirus in Captive Panthera Highlights Viral Promiscuity and the Need for Better Prevention Strategies.

Canine Distemper Virus (CDV) is a multi-host morbillivirus that infects virtually all Carnivora and a few non-human primates. Here we describe a CDV outbreak in an exotic felid rescue center that led to the death of eight felids in the genus Panthera. Similar to domestic dogs and in contrast to previously described CDV cases in Panthera, severe pneumonia was the primary lesion and no viral antigens or CDV-like lesions were detected in the central nervous system. Four tigers succumbed to opportunistic infections. Viral hemagglutinin (H)-gene sequence was up to 99% similar to strains circulating contemporaneously in regional wildlife. CDV lesions in raccoons and skunk were primarily encephalitis. A few affected felids had at least one previous vaccination for CDV, while most felids at the center were vaccinated during the outbreak. Panthera sharing a fence or enclosure with infected conspecifics had significantly higher chances of getting sick or dying, suggesting tiger-tiger spread was more likely than recurrent spillover. Prior vaccination was incomplete and likely not protective. This outbreak highlights the need for further understanding of CDV epidemiology for species conservation and public health.

Screening the nose, throat and the naso-pharynx for methicillin-resistant Staphylococcus aureus: a pilot study.

Patients who carry nasal methicillin-resistant Staphylococcus aureus (MRSA) may also harbour MRSA in the oro-pharyngeal cavity. However, the naso-oro-pharyngeal co-carriage is infrequently assessed. The incidence of concurrent MRSA carriage of the naso-oro-pharynx was ascertained, and the sensitivity of two methods, a throat swab and a phosphate buffered saline (PBS) oral rinse, for MRSA detection was investigated. Among nasal MRSA carriers, 80% harboured MRSA in the oro-pharynx. Among these patients, 15% had MRSA detected in the oro-pharynx and not in the throat. Oro-pharyngeal colonisation represents a significant reservoir to persistence as well as nasal recolonisation. Decolonisation methods effective in reducing oro-pharyngeal MRSA in addition to nasal carriage should be investigated.