Endothelial ENaC-α Restrains Oxidative Stress in Lung Capillaries in Murine Pneumococcal Pneumonia-associated Acute Lung Injury.

Infection of lung endothelial cells with pneumococci activates the superoxide-generating enzyme NADPH oxidase 2 (NOX2), involving the pneumococcal virulence factor pneumolysin (PLY). Excessive NOX2 activity disturbs capillary barriers, but its global inhibition can impair bactericidal phagocyte activity during pneumococcal pneumonia. Depletion of the α subunit of the epithelial sodium channel (ENaC) in pulmonary endothelial cells increases expression and PMA-induced activity of NOX2. Direct ENaC activation by TIP peptide improves capillary barrier function -measured by electrical cell substrate impedance sensing in endothelial monolayers and by Evans Blue Dye incorporation in mouse lungs- following infection with pneumococci. PLY-induced hyperpermeability in HL-MVEC monolayers is abrogated by both NOX2 inhibitor gp91dstat and TIP peptide. Endothelial NOX2 expression is assessed by increased surface membrane presence of phosphorylated p47phox subunit (Western blotting) in vitro and by co-localization of CD31 and gp91phox in mouse lung slices using DuoLink, whereas NOX2-generated superoxide is measured by chemiluminescence. TIP peptide blunts PMA-induced NOX2 activity in cells expressing ENaC-α, but not in neutrophils, which lack ENaC. Conditional endothelial ENaC-α KO (enENaC-α KO) mice develop increased capillary leak upon i.t. instillation with PLY or pneumococci, compared to wild type (wt) animals. TIP peptide diminishes capillary leak in Sp-infected wt mice, without significantly increasing lung bacterial load. Lung slices from Sp-infected enENaC-α KO mice have a significantly increased endothelial NOX2 expression, as compared to infected CRE mice. In conclusion, endothelial ENaC may represent a novel therapeutic target to reduce NOX2-mediated oxidative stress and capillary leak in ARDS, without impairing host defense.

Growth Mindset Messages from Instructors Improve Academic Performance Among First-Generation College Students.

First-generation (FG) college students (i.e., those for whom neither parent/guardian obtained a bachelor's degree) experience more barriers in college, compared with continuing-generation students. These barriers are compounded by subtle messages from instructors that convey the idea that natural talent is necessary for success in scientific fields. In contrast, growth mindset messages communicate that ability can improve with effort, help-seeking, and using productive study strategies. In a large enrollment introductory biology course, students were randomly assigned to receive email messages from their instructor after the first two exams containing either a growth mindset or control message. The intervention improved grades in the course for everyone, on average, compared with control messages, and were especially beneficial for FG students. This increase in performance was partially mediated by increased activity accessing course materials on the course website. This study provides preliminary evidence that instructors communicating growth mindset messages can support FG students' performance.

Ascending the nucleosome face: recognition and function of structured domains in the histone H2A-H2B dimer.

Research over the past decade has greatly expanded our understanding of the nucleosome's role as a dynamic hub that is specifically recognized by many regulatory proteins involved in transcription, silencing, replication, repair, and chromosome segregation. While many of these nucleosome interactions are mediated by post-translational modifications in the disordered histone tails, it is becoming increasingly apparent that structured regions of the nucleosome, including the histone fold domains, are also recognized by numerous regulatory proteins. This review will focus on the recognition of structured domains in the histone H2A-H2B dimer, including the acidic patch, the H2A docking domain, the H2B α3-αC helices, and the HAR/HBR domains, and will survey the known biological functions of histone residues within these domains. Novel post-translational modifications and trans-histone regulatory pathways involving structured regions of the H2A-H2B dimer will be highlighted, along with the role of intrinsic disorder in the recognition of structured nucleosome regions.

Accumulation of the cyclobutane thymine dimer in defined sequences of free and nucleosomal DNA.

Photochemical cyclobutane dimerization of adjacent thymines generates the major lesion in DNA caused by exposure to sunlight. Not all nucleotide sequences and structures are equally susceptible to this reaction or its potential to create mutations. Photostationary levels of the cyclobutane thymine dimer have now been quantified in homogenous samples of DNA reconstituted into nucleosome core particles to examine the basis for previous observations that such structures could induce a periodicity in dimer yield when libraries of heterogeneous sequences were used. Initial rate studies did not reveal a similar periodicity when a homogenous core particle was analyzed, but this approach examined only formation of this photochemically reversible cyclobutane dimer. Photostationary levels result from competition between dimerization and reversion and, as described in this study, still express none of the periodicity within two alternative core particles that was evident in heterogeneous samples. Such periodicity likely arises from only a limited set of sequences and structural environments that are not present in the homogeneous and well-characterized assemblies available to date.

Probing the effects of DNA-protein interactions on DNA hole transport: the N-terminal histone tails modulate the distribution of oxidative damage and chemical lesions in the nucleosome core particle.

The ability of DNA to transport positive charges, or holes, over long distances is well-established, but the mechanistic details of how this process is influenced by packaging into DNA-protein complexes have not been fully delineated. In eukaryotes, genomic DNA is packaged into chromatin through its association with the core histone octamer to form the nucleosome core particle (NCP), a complex whose structure can be modulated through changes in the local environment and the histone proteins. Because (i) varying the salt concentration and removing the histone tails influence the structure of the NCP in known ways and (ii) previous studies have shown that DNA hole transport (HT) occurs in the nucleosome, we have used our previously described 601 sequence NCPs to test the hypothesis that DNA HT dynamics can be modulated by structural changes in a DNA-protein complex. We show that at low salt concentrations there is a sharp increase in long-range DNA HT efficiency in the NCP as compared to naked DNA. This enhancement of HT can be negated by either removal of the histone tails at low salt concentrations or disruption of the interaction of the packaged DNA and the histone tails by increasing the buffer's ionic strength. Association of the histone tails with 601 DNA at low salt concentrations shifts the guanine damage spectrum to favor lesions like 8-oxoguanine in the NCP, most likely through modulation of the rate of the reaction of the guanine radical cation with oxygen. These experimental results indicate that for most genomic DNA, the influence of DNA-protein interactions on DNA HT will depend strongly on the level of protection of the DNA nucleobases from oxygen. Further, these results suggest that the oxidative damage arising from DNA HT may vary in different genomic regions depending on the presence of either euchromatin or heterochromatin.

The first systematic experimentation in music therapy: the genius of James Leonard Corning.

BACKGROUND: The development of music therapy in the United States prior to 1950 has a fascinating but not well known history. The present study illuminates the music therapy research of James Leonard Corning (1855-1923), a prominent neurologist practicing during the late nineteenth-century in New York City. OBJECTIVE: The purpose of this study was to provide biographical information and description of a series of music therapy experiments conducted by Corning. His 1899 article appearing in the Medical Record: A Weekly Journal of Medicine and Surgery summarized a series of inventive experiments using music to affect emotional states in people with mild behavioral-emotional and sleep disorders. METHODS: Information was analyzed using a set of primary and secondary sources from contemporaneous books, newspapers and journals. These sources provided biographical information and insight into his experimental methods. Recent sources provided a framework to help understand his conclusions from the viewpoint of late nineteenth-century physicians and for current practitioners of music therapy. RESULTS: Findings indicate that Corning's rationale for using music, visual figures and, occasional medication in the treatment of behavioral-emotional disorders was successful in influencing feelings and emotions in a positive way. He believed that during pre-sleep and sleep, cognitive processes became dormant, allowing the penetration of "musical vibrations" into the subconscious eliminating morbid thoughts that plagued his patients. CONCLUSIONS: Understanding Corning's contributions to music therapy will assist contemporary educators and therapists to better understand the impact of early contributions to music therapy by late nineteenth-century practitioners such as Corning.

Recommendations for Effective Integration of Ethics and Responsible Conduct of Research (E/RCR) Education into Course-Based Undergraduate Research Experiences: A Meeting Report.

Advancement of the scientific enterprise relies on individuals conducting research in an ethical and responsible manner. Educating emergent scholars in the principles of ethics/responsible conduct of research (E/RCR) is therefore critical to ensuring such advancement. The recent impetus to include authentic research opportunities as part of the undergraduate curriculum, via course-based undergraduate research experiences (CUREs), has been shown to increase cognitive and noncognitive student outcomes. Because of these important benefits, CUREs are becoming more common and often constitute the first research experience for many students. However, despite the importance of E/RCR in the research process, we know of few efforts to incorporate E/RCR education into CUREs. The Ethics Network for Course-based Opportunities in Undergraduate Research (ENCOUR) was created to address this concern and promote the integration of E/RCR within CUREs in the biological sciences and related disciplines. During the inaugural ENCOUR meeting, a four-pronged approach was used to develop guidelines for the effective integration of E/RCR in CUREs. This approach included: 1) defining appropriate student learning objectives; 2) identifying relevant curriculum; 3) identifying relevant assessments; and 4) defining key aspects of professional development for CURE facilitators. Meeting outcomes, including the aforementioned E/RCR guidelines, are described herein.

Attenuation of DNA charge transport by compaction into a nucleosome core particle.

The nucleosome core particle (NCP) is the fundamental building block of chromatin which compacts approximately 146 bp of DNA around a core histone protein octamer. The effects of NCP packaging on long-range DNA charge transport reactions have not been adequately assessed to date. Here we study DNA hole transport reactions in a 157 bp DNA duplex (AQ-157TG) incorporating multiple repeats of the DNA TG-motif, a strong NCP positioning sequence and a covalently attached Anthraquinone photooxidant. Following a thorough biophysical characterization of the structure of AQ-157TG NCPs by Exonuclease III and hydroxyl radical footprinting, we compared the dynamics of DNA charge transport in ultraviolet-irradiated free and NCP-incorporated AQ-157TG. Compaction into a NCP changes the charge transport dynamics in AQ-157TG drastically. Not only is the overall yield of oxidative lesions decreased in the NCPs, but the preferred sites of oxidative damage change as well. This NCP-dependent attenuation of DNA charge transport is attributed to DNA-protein interactions involving the folded histone core since removal of the histone tails did not perturb the charge transport dynamics in AQ-157TG NCPs.

Promoting Collaborative Classrooms: The Impacts of Interdependent Cooperative Learning on Undergraduate Interactions and Achievement.

Collaboration is an important career skill and vital to student understanding of the social aspects of science, but less is known about relationships among collaborative-learning strategies, classroom climate, and student learning. We sought to increase the collaborative character of introductory undergraduate laboratory classrooms by analyzing a 9-week intervention in 10 classrooms ( n = 251) that participated in cooperative-learning modules (promoting interdependence via a modified jigsaw technique). Students in an additional 10 classrooms ( n = 232) completed the same material in an unstructured format representative of common educational practice. Results showed that, when between-class variance was controlled for, intervention students did not score higher on weekly quizzes, but science interest and prior science experience had a reduced relationship to quiz performance in intervention classrooms. Also, intervention classrooms showed increased collaborative engagement at both whole-class and individual levels (24 students at three time points), but the intervention was only one of several factors found to account for late-intervention classroom collaborative engagement (prosocial behavior and discussion practices). Taken together, findings suggest that integrating interdependence-based tasks may foster collaborative engagement at both small-group and whole-classroom levels, but by itself may not be enough to promote increased student achievement.

Hole transfer energetics in structurally distorted DNA: the nucleosome core particle.

The dynamics of long-range hole transport (HT) through DNA are critically dependent on the relative energies of guanine radical cation states. Electrostatic contacts with protein fragments and changes in the secondary structure of the DNA helix are expected to directly influence the stability of a guanine radical cation. This expectation is especially relevant when considering DNA HT in the eukaryotic nucleus, where DNA is condensed into nucleosome core particles (NCPs), the fundamental building blocks of chromatin. Using quantum-chemical calculations, we consider how the electrostatic interactions between the DNA nucleobases and the surrounding protein and water atoms and the structural changes in DNA arising from compaction into a NCP affect the energetics of hole transfer between guanine sites. We find that structural distortions of DNA can have dramatic consequences for the stability of a guanine radical cation, and therefore, these effects must be taken into account during the modeling of in vivo DNA HT and in the interpretation of experimental findings. When the electrostatic potential arising from the water and basic histone proteins is included we find that DNA-histone contacts, particularly between arginine residues and the DNA minor groove, destabilize the hole state on specific guanine residues. Therefore, contacts between the DNA nucleobases and basic amino acids have the potential to perturb the sites of preferred hole stability in DNA.

Persistent Lobar Atelectasis in a Patient With Chronic Hoarseness.

A 61-year-old woman presented for outpatient evaluation of a 1-week history of fever and upper respiratory symptoms. She denied tobacco use, weight loss, hemoptysis, chronic cough, or recent travel and was in otherwise good health. Her medical history was insignificant except for her chronic hoarseness from a prior laryngeal disease. She denied any worsening hoarseness or any other vocal changes. She did report a positive family history of squamous cell lung cancer in her father.

Genome Sequences of Mycobacteriophages Findley, Hurricane, and TBond007.

We report here the genome sequences of three newly isolated phages that infect Mycobacterium smegmatis mc2155. Phages Findley, Hurricane, and TBond007 were discovered in geographically distinct locations and are related to cluster K mycobacteriophages, with Findley being similar to subcluster K2 phages and Hurricane and TBond007 being similar to subcluster K3 phages.

Prophage-mediated defence against viral attack and viral counter-defence.

Temperate phages are common, and prophages are abundant residents of sequenced bacterial genomes. Mycobacteriophages are viruses that infect mycobacterial hosts including Mycobacterium tuberculosis and Mycobacterium smegmatis, encompass substantial genetic diversity and are commonly temperate. Characterization of ten Cluster N temperate mycobacteriophages revealed at least five distinct prophage-expressed viral defence systems that interfere with the infection of lytic and temperate phages that are either closely related (homotypic defence) or unrelated (heterotypic defence) to the prophage. Target specificity is unpredictable, ranging from a single target phage to one-third of those tested. The defence systems include a single-subunit restriction system, a heterotypic exclusion system and a predicted (p)ppGpp synthetase, which blocks lytic phage growth, promotes bacterial survival and enables efficient lysogeny. The predicted (p)ppGpp synthetase coded by the Phrann prophage defends against phage Tweety infection, but Tweety codes for a tetrapeptide repeat protein, gp54, which acts as a highly effective counter-defence system. Prophage-mediated viral defence offers an efficient mechanism for bacterial success in host-virus dynamics, and counter-defence promotes phage co-evolution.

Pulmonary Cryptococcosis in the Immunocompetent Patient-Many Questions, Some Answers.

Background. There are no prospective data regarding the management of pulmonary cryptococcosis in the immunocompetent patient. Clinical guidelines recommend oral fluconazole for patients with mild to moderate symptoms and amphotericin B plus flucytosine followed by fluconazole for severe disease. It is unclear whether patients who have histological evidence of Cryptococcus neoformans but negative cultures will even respond to drug treatment. We evaluated and managed a patient whose presentation and course raised important questions regarding the significance of negative cultures, antifungal choices, duration of therapy, and resolution of clinical, serologic, and radiographic findings. Methods. In addition to our experience, to answer these questions we reviewed available case reports and case series regarding immunocompetent patients with pulmonary cryptococcosis for the last 55 years using the following definitions: Definite - Clinical and/or radiographic findings of pulmonary infection and respiratory tract isolation of C. neoformans without other suspected etiologies; Probable - Clinical and radiographic findings of pulmonary infection, histopathologic evidence of C. neoformans, and negative fungal cultures with or without a positive cryptococcal polysaccharide antigen. Results. Pulmonary cryptococcosis resolves in most patients with or without specific antifungal therapy. Clinical, radiographic, and serologic resolution is slow and may take years. Conclusions. Persistently positive antigen titers are most common in untreated patients and may remain strongly positive despite complete or partial resolution of disease. Respiratory fungal cultures are often negative and may indicate nonviable organisms.

Ira Maximilian Altshuler: psychiatrist and pioneer music therapist.

The purpose of this study was to examine the life of Ira Maximilian Altshuler, psychiatrist and pioneer music therapist. In 1938, Dr. Altshuler initiated one of the first large-scale music therapy programs for mentally ill persons in the country at Detroit's Eloise Hospital. His innovative programs combined psychoanalytic techniques and music therapy methods specifically designed for use with large groups of clients. He later trained some of the first music therapy interns in the country, including Carol Collins, who served for many years as Professor of Music Therapy at Wayne State University, and Esther Goetz Gilliland, who later became President of NAMT. Dr. Altshuler promoted the practice and profession tirelessly, speaking to numerous audiences over the years and writing 19 articles about music therapy. Altshuler participated in the National Association for Music Therapy (NAMT) organizational meeting held in New York City in 1950. An active member of the organization for many years, he served on the Research Committee and hosted the 1955 national NAMT conference in Detroit. Even after Altshuler's retirement from Eloise Hospital in 1963, he remained active in numerous civic, music, and music therapy activities until his death 5 year later. Ira Altshuler should be remembered along with other music therapists from the time-Willem Van de Wall, Harriet Ayer Seymour and others-who vigorously embraced and advanced the status of the profession.

An unusual cause of massive pleural effusion.

Pleural effusions in ovarian hyperstimulation syndrome, whether transudative or exudative, can occur in up to 30% of cases. This disorder is always reversible but may have various clinical presentations and degrees of severity. Although assessing for risk factors to predict clinical severity is helpful, it is rare for ovarian hyperstimulation syndrome to present as a massive pleural effusion requiring emergent intervention. In this study, such a case is reported.

Stable DNA-protein cross-links are products of DNA charge transport in a nucleosome core particle.

DNA-protein cross-links (DPCs) in nucleosome core particles (NCPs), the fundamental building block of chromatin, arise during times of cellular oxidative stress. These lesions are expected to be detrimental to the cell due to interference with processes like chromatin remodeling, transcription, DNA replication, and epigenetic marking. However, much is still unknown about the mechanisms leading to the formation of DPCs in NCPs, and the exact sites of these lesions in chromatin have not been delineated. During DNA charge transport (CT), an oxidant leads to the formation of a guanine radical cation (G*+) which then becomes mobile and migrates away from the initial site of damage. Since previous studies have established that reactions between a G*+ and some amino acids lead to DPC formation in both DNA-peptide and DNA-protein complexes, we hypothesized that DNA CT could lead to DPC formation within NCPs. To test this hypothesis, we studied DNA CT reactions in NCPs reconstituted with DNA containing (i) the 601 NCP positioning sequence and (ii) 14 bp of a linker DNA with a covalently attached anthraquinone (AQ) photooxidant. Collectively, the results from Western blotting, EMSAs, and DNA footprinting reactions lead to the conclusion that AQ-initiated DNA CT is responsible for DNA-H3 cross-linking in one specific region of these NCPs. Furthermore, these DPCs are stable for days at 37 degrees C, indicating that DNA CT in chromatin can lead to long-lived DNA lesions which the cell must somehow find and excise.

The relA homolog of Mycobacterium smegmatis affects cell appearance, viability, and gene expression.

The modification of metabolic pathways to allow for a dormant lifestyle appears to be an important feature for the survival of pathogenic bacteria within their host. One regulatory mechanism for persistent Mycobacterium tuberculosis infections is the stringent response. In this study, we analyze the stringent response of a nonpathogenic, saprophytic mycobacterial species, Mycobacterium smegmatis. The use of M. smegmatis as a tool for studying the mycobacterial stringent response was demonstrated by measuring the expression of two M. tuberculosis genes, hspX and eis, in M. smegmatis in the presence and absence of rel(Msm). The stringent response plays a role in M. smegmatis cellular and colony formation that is suggestive of changes in the bacterial cell wall structure.

Distance-dependent activation energies for hole injection from protonated 9-amino-6-chloro-2-methoxyacridine into duplex DNA.

The recent investigation of the apparently anomalous attenuation factor (beta > 1.5 A(-1)) for photoinduced hole injection into DNA duplexes modified by protonated 9-amino-6-chloro-2-methoxyacridine (X+) led to the conclusion that in addition to the electronic couplings, the activation energy must also be distance-dependent. In this communication we report the verification of this postulate by direct measurements of the activation energies for a series of (X+)-modified DNA duplexes which sample an appreciable range of donor-acceptor distances (approximately 4-11 A). The resulting changes in thermal activation energy can be explained within the framework of a distance-dependent reorganization energy.