Crystal structures of the human Dysferlin inner DysF domain

Background: Mutations in dysferlin, the first protein linked with the cell membrane repair mechanism, causes a group of muscular dystrophies called dysferlinopathies. Dysferlin is a type two-anchored membrane protein, with a single C terminal trans-membrane helix, and most of the protein lying in cytoplasm. Dysferlin contains several C2 domains and two DysF domains which are nested one inside the other. Many pathogenic point mutations fall in the DysF domain region. Results: We describe the crystal structure of the human dysferlin inner DysF domain with a resolution of 1.9 Angstroms. Most of the pathogenic mutations are part of aromatic/arginine stacks that hold the domain in a folded conformation. The high resolution of the structure show that these interactions are a mixture of parallel ring/guanadinium stacking, perpendicular H bond stacking and aliphatic chain packing. Conclusions: The high resolution structure of the Dysferlin DysF domain gives a template on which to interpret in detail the pathogenic mutations that lead to disease

Pemanfaatan Pektin Yang Diisolasi Dari Kulit Dan Buah Salak (Salacca Edulis Reinw) Dalam Uji in Vivo Penurunan Kadar Kolesterol Dan Glukosa Darah Pada Tikus Jantan Galur Wistar

Pektin merupakan polimer yang terdapat dalam dinding sel tumbuhan dan dapat ditemukan dalam berbagai jenis tanaman pangan. Pektin pada tanaman banyak terdapat pada kulit dan daging buahnya. Pektin memiliki manfaat yang banyak, terutama di bidang kesehatan. Penelitian ini merupakan penelitian pendahuluan untuk mendapatkan pektin dari kulit dan daging buah salak pondoh (Salacca edulis Reinw.), yang keberadaannya berlimpah di Kabupaten Sleman, serta untuk mengetahui aktivitas penurunan kadar glukosa dan kolesterol dalam uji in vivo. Dilakukan 2 cara untuk mendapatkan pektin dari kulit dan daging buah salak, yaitu dengan soxhletasi dan perebusan. Untuk metode soxhletasi digunakan kondisi pH 2,5-3, dengan suhu 90°C. Sedangkan untuk metode perebusan, digunakan kondisi pH 1,5 dengan suhu 80°C. Tikus dibagi menjadi 3 kelompok untuk masing-masing uji penurunan kadar glukosa dan uji penurunan kadar kolesterol. Kelompok I kontrol normal hanya diberikan diet normal, kelompok II kontrol negatif hanya diberikan diet tinggi gula pada kelompok uji penurunan glukosa atau diet tinggi lemak pada kelompok uji penurunan kadar kolesterol, dan kelompok III perlakuan pektin 1,8g/kg BB beserta diet tinggi gula atau diet tinggi lemak. Kadar glukosa dan kolesterol dalam darah diukur pada akhir perlakuan. Kemudian data yang diperoleh dianalisis

Intrahistiocytic Storage of Clofazimine Crystals in a Cat

A 13-year-old castrated male Maine coon cat with a 5-year history of atypical mycobacteriosis was euthanized and submitted for necropsy. The cat had been kept in clinical remission since diagnosis using a combination of the antimycobacterial drug clofazimine and additional multimodal antimicrobial therapy. Grossly, tissues were diffusely discolored red-brown to yellow. Histologically, the myocardial interstitum was expanded by numerous, often multinucleated cells, which were distended by uniformly shaped acicular cytoplasmic spaces. These cells were immunopositive for CD18 and immunonegative for desmin, suggesting a histiocytic rather than muscular origin. Macrophages in other tissues contained similar acicular spaces. Ultrastructurally, the spaces were surrounded by 2 lipid membranes, resembling an autophagosome. Based on the clinical history and histologic, immunohistochemical, and ultrastructural data, we diagnosed clofazimine crystal storage. To our knowledge, this is the first report of clofazimine storage in a cat or within myocardial interstitial macrophages

Obstructive sleep apnea and electrocardiographic P-wave morphology.

INTRODUCTION: Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder with important cardiovascular implications. Left atrial abnormality can be identified by electrocardiographic P-wave morphology and is considered an important risk for atrial fibrillation (AF) and stroke, both of which have been associated with OSA. We hypothesized that severity of OSA would be associated with more abnormal electrocardiographic P-wave morphology as indicated by P-wave terminal force in V METHODS: Patients who underwent clinically indicated polysomnography and had 12-lead ECG were identified through medical record review. Logistic regression was used to determine the associations between the measures of OSA severity (apnea hypopnea index [AHI] and mean nocturnal oxygen [O RESULTS: A total of 261 patients (mean age: 57 years old, male: 52%) were included in the study. Multivariate analysis showed that AHI was associated with abnormal PTFV CONCLUSION: In a sleep clinic cohort, there was significant association between OSA severity and ECG-defined left atrial abnormality

Exploration of Perceived Psychosocial Benefits of Senior Companion Program Participation Among Urban-Dwelling, Low-Income Older Adult Women Volunteers

Background: As the older adult population increases, it is imperative to increase older adults' opportunities for social involvement, thus maintaining their important roles and contributions to society. While there are known health-related benefits of volunteerism among older adults, a dearth of information exists on the perceived benefits of volunteerism among low-income and ethnic minority older adults. Purpose: To understand the perceived psychosocial benefits of volunteering in the Senior Companion Program and to present findings of focus groups conducted with urban-dwelling, low-income older adult women volunteers. Design and Methods: Inductive content analysis and the Dedoose qualitative data analysis software were used for analyzing data obtained from 59 older adult women Senior Companions who participated in nine focus groups. Results: Content analyses of the focus group transcripts identified four major themes: (1) Reducing social isolation; (2) Improving quality of life; (3) Finding purpose and meaning; and (4) Increasing understanding of aging. The majority of our participants (81%) were African American women, with a mean age of 70 years. Approximately 83.1% had completed high school and 62.7% lived below the poverty line. Discussion and Implications: Findings provided data rich in descriptions of positive psychosocial outcomes, finding meaning and purpose, and a better understanding of aging in urban-dwelling, low-income older women volunteers. The findings also provide support for the need for policies and programs that promote civic engagement in this population

A Cold Atom Radio-Frequency Magnetometer

We propose and demonstrate a radio-frequency atomic magnetometer with sub-Doppler laser cooled rubidium-87. With a simple and compact design, our system demonstrates a sensitivity of 330 pT/ √ Hz in an unshielded environment, thus matching or surpassing previously reported cold atoms designs. By merging the multiple uses and robustness of radio-frequency atomic magnetometers with the detailed control of laser cooling, our cold atom radio-frequency magnetometer has the potential to move applications of atomic magnetometry to high spatial resolution. Direct impact in metrology for applied sciences, materials characterization, and nanotechnology can be anticipated

Structural Evidence for the Dopamine-First Mechanism of Norcoclaurine Synthase

Norcoclaurine synthase (NCS) is a Pictet-Spenglerase that catalyzes the first key step in plant benzylisoquinoline alkaloid metabolism, a compound family that includes bioactive natural products such as morphine. The enzyme has also shown great potential as a biocatalyst for the formation of chiral isoquinolines. Here we present new high-resolution X-ray crystallography data describing Thalictrum flavum NCS bound to a mechanism-inspired ligand. The structure supports two key features of the NCS "dopamine-first" mechanism: the binding of dopamine catechol to Lys-122 and the position of the carbonyl substrate binding site at the active site entrance. The catalytically vital residue Glu-110 occupies a previously unobserved ligand-bound conformation that may be catalytically significant. The potential roles of inhibitory binding and alternative amino acid conformations in the mechanism have also been revealed. This work significantly advances our understanding of the NCS mechanism and will aid future efforts to engineer the substrate scope and catalytic properties of this useful biocatalyst

Epidemiology, patterns of care, and mortality for patients with acute respiratory distress syndrome in intensive care units in 50 countries

IMPORTANCE: Limited information exists about the epidemiology, recognition, management, and outcomes of patients with the acute respiratory distress syndrome (ARDS). OBJECTIVES: To evaluate intensive care unit (ICU) incidence and outcome of ARDS and to assess clinician recognition, ventilation management, and use of adjuncts-for example prone positioning-in routine clinical practice for patients fulfilling the ARDS Berlin Definition. DESIGN, SETTING, AND PARTICIPANTS:The Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG SAFE) was an international, multicenter, prospective cohort study of patients undergoing invasive or noninvasive ventilation, conducted during 4 consecutive weeks in the winter of 2014 in a convenience sample of 459 ICUs from 50 countries across 5 continents. EXPOSURES:Acute respiratory distress syndrome. MAIN OUTCOMES AND MEASURES: The primary outcome was ICU incidence of ARDS. Secondary outcomes included assessment of clinician recognition of ARDS, the application of ventilatory management, the use of adjunctive interventions in routine clinical practice, and clinical outcomes from ARDS. RESULTS: Of 29,144 patients admitted to participating ICUs, 3022 (10.4%) fulfilled ARDS criteria. Of these, 2377 patients developed ARDS in the first 48 hours and whose respiratory failure was managed with invasive mechanical ventilation. The period prevalence of mild ARDS was 30.0% (95% CI, 28.2%-31.9%); of moderate ARDS, 46.6% (95% CI, 44.5%-48.6%); and of severe ARDS, 23.4% (95% CI, 21.7%-25.2%). ARDS represented 0.42 cases per ICU bed over 4 weeks and represented 10.4% (95% CI, 10.0%-10.7%) of ICU admissions and 23.4% of patients requiring mechanical ventilation. Clinical recognition of ARDS ranged from 51.3% (95% CI, 47.5%-55.0%) in mild to 78.5% (95% CI, 74.8%-81.8%) in severe ARDS. Less than two-thirds of patients with ARDS received a tidal volume 8 of mL/kg or less of predicted body weight. Plateau pressure was measured in 40.1% (95% CI, 38.2-42.1), whereas 82.6% (95% CI, 81.0%-84.1%) received a positive end-expository pressure (PEEP) of less than 12 cm H2O. Prone positioning was used in 16.3% (95% CI, 13.7%-19.2%) of patients with severe ARDS. Clinician recognition of ARDS was associated with higher PEEP, greater use of neuromuscular blockade, and prone positioning. Hospital mortality was 34.9% (95% CI, 31.4%-38.5%) for those with mild, 40.3% (95% CI, 37.4%-43.3%) for those with moderate, and 46.1% (95% CI, 41.9%-50.4%) for those with severe ARDS. CONCLUSIONS AND RELEVANCE: Among ICUs in 50 countries, the period prevalence of ARDS was 10.4% of ICU admissions. This syndrome appeared to be underrecognized and undertreated and associated with a high mortality rate. These findings indicate the potential for improvement in the management of patients with ARDS

Single step syntheses of (1 S)-aryltetrahydroisoquinolines by norcoclaurine synthases

The 1-aryl-tetrahydroisoquinoline (1-aryl-THIQ) moiety is found in many biologically active molecules. Single enantiomer chemical syntheses are challenging and although some biocatalytic routes have been reported, the substrate scope is limited to certain structural motifs. The enzyme norcoclaurine synthase (NCS), involved in plant alkaloid biosynthesis, has been shown to perform stereoselective Pictet–Spengler reactions between dopamine and several carbonyl substrates. Here, benzaldehydes are explored as substrates and found to be accepted by both wild-type and mutant constructs of NCS. In particular, the variant M97V gives a range of (1 S)-aryl-THIQs in high yields (48–99%) and e.e.s (79–95%). A cocrystallised structure of the M97V variant with an active site reaction intermediate analogue is also obtained with the ligand in a pre-cyclisation conformation, consistent with (1 S)-THIQs formation. Selected THIQs are then used with catechol O-methyltransferases with exceptional regioselectivity. This work demonstrates valuable biocatalytic approaches to a range of (1 S)-THIQ

Argyrin B a non-competitive inhibitor of the human immunoproteasome exhibiting preference for β1i

Inhibitors of the proteasome have found broad therapeutic applications however, they show severe toxicity due to the abundance of proteasomes in healthy cells. In contrast, inhibitors of the immunoproteasome, which is upregulated during disease states, are less toxic and have increased therapeutic potential including against autoimmune disorders. In this project, we report argyrin B, a natural product cyclic peptide to be a reversible, non-competitive inhibitor of the immunoproteasome. Argyrin B showed selective inhibition of the β5i and β1i sites of the immunoproteasome over the β5c and β1c sites of the constitutive proteasome with nearly 20-fold selective inhibition of β1i over the homologous β1c. Molecular modelling attributes the β1i over β1c selectivity to the small hydrophobic S1 pocket of β1i and β5i over β5c to site-specific amino acid variations that enable additional bonding interactions and stabilization of the binding conformation. These findings facilitate the design of immunoproteasome selective and reversible inhibitors that may have a greater therapeutic potential and lower toxicity