Validity of the iHealth-BP7 and Withings-BP800 Self Measurement Blood Pressure Monitor

PURPOSE: The purpose of this study is to validate the iHealth-BP7 and Withings-BP800 monitors according to the European Society of Hypertension (ESH) International Protocol revision 2010. METHODS: Data from 11 participants (31.6 ± 2.2 years) were initially examined according to the ESH International Protocol for the validation of BP measuring devices. Participants were asked to sit and relax for 10-15 mins with legs uncrossed, and back supported prior to the test. In all participants, sequential left arm measurements were performed by two trained observers using a mercury sphygmomanometer and one supervisor using the device. Collected data were screened according to the ESH protocol RESULTS: The mean differences between the monitor and sphygmomanometer readings were -0.55±3.75 (SBP) and 0.54±3.62 (DBP) for iHealth-BP7 and 3.18±4.37 (SBP) and - 0.35±5.42 (DBP) for Withings-BP800. The iHealth-BP7 monitor passed all of the modified requirements, however the WithingsBP800 did not meet the last phase of the modified protocol. CONCLUSION: The iHealth-BP7 monitor is recommended as a valid home BP monitoring device, however the Withings-BP800 fails to meet the ESH criteria in this study potentially due to the small sample size. Since the ESH protocol requires 33 subjects, further study with additional participants is warranted to determine validation of both devices

Ionic Tuning of Cobaltites at the Nanoscale

Control of materials through custom design of ionic distributions represents a powerful new approach to develop future technologies ranging from spintronic logic and memory devices to energy storage. Perovskites have shown particular promise for ionic devices due to their high ion mobility and sensitivity to chemical stoichiometry. In this work, we demonstrate a solid-state approach to control of ionic distributions in (La,Sr)CoO$_{3}$ thin films. Depositing a Gd capping layer on the perovskite film, oxygen is controllably extracted from the structure, up-to 0.5 O/u.c. throughout the entire 36 nm thickness. Commensurate with the oxygen extraction, the Co valence state and saturation magnetization show a smooth continuous variation. In contrast, magnetoresistance measurements show no-change in the magnetic anisotropy and a rapid increase in the resistivity over the same range of oxygen stoichiometry. These results suggest significant phase separation, with metallic ferromagnetic regions and oxygen-deficient, insulating, non-ferromagnetic regions, forming percolated networks. Indeed, X-ray diffraction identifies oxygen-vacancy ordering, including transformation to a brownmillerite crystal structure. The unexpected transformation to the brownmillerite phase at ambient temperature is further confirmed by high-resolution scanning transmission electron microscopy which shows significant structural - and correspondingly chemical - phase separation. This work demonstrates room-temperature ionic control of magnetism, electrical resistivity, and crystalline structure in a 36 nm thick film, presenting new opportunities for ionic devices that leverage multiple material functionalities

Mutational Analysis of the Nitrogenase Carbon Monoxide Protective Protein CowN Reveals That a Conserved C‑Terminal Glutamic Acid Residue Is Necessary for Its Activity

Nitrogenase is the only enzyme that catalyzes the reduction of nitrogen gas into ammonia. Nitrogenase is tightly inhibited by the environmental gas carbon monoxide (CO). Many nitrogen fixing bacteria protect nitrogenase from CO inhibition using the protective protein CowN. This work demonstrates that a conserved glutamic acid residue near the C-terminus of Gluconacetobacter diazotrophicus CowN is necessary for its function. Mutation of the glutamic acid residue abolishes both CowN’s protection against CO inhibition and the ability of CowN to bind to nitrogenase. In contrast, a conserved C-terminal cysteine residue is not important for CO protection by CowN. Overall, this work uncovers structural features in CowN that are required for its function and provides new insights into its nitrogenase binding and CO protection mechanism

Cellular Milieu Imparts Distinct Pathological α-Synuclein Strains in α-Synucleinopathies

Introduction: In Lewy body diseases-including Parkinson\u27s disease, without or with dementia, dementia with Lewy bodies, and Alzheimer\u27s disease with Lewy body co-pathology -α-synuclein (α-Syn) aggregates in neurons as Lewy bodies and Lewy neurites. By contrast, in multiple system atrophy α-Syn accumulates mainly in oligodendrocytes as glial cytoplasmic inclusions (GCIs) Objective: Our objective was to determine the conformational and biological profiles of a-Syn strains. Methods: The following methods were used to collect and analyze data: Recombinant α-Syn purification and in vitro fibrillization. Preparation of sarkosyl-insoluble fractions from disease and control brains. Sandwich ELISA. Cell cultures. Stereotaxic injection of sarkosyl-insoluble fraction of pathological α-Syn and α-Syn PFFs. Immunohistochemistry. Purification and depletion of α-Syn from the sarkosyl-insoluble fraction by immunoprecipitation. Results: GCI-α-Syn forms structures that are more compact and it is about 1,000-fold more potent than LB-α-Syn in seeding α-Syn aggregation, consistent with the highly aggressive nature of multiple system atrophy. We found that oligodendrocytes but not neurons transform misfolded α-Syn into a GCI-like strain. Moreover, GCI-α-Syn maintains its high seeding activity when propagated in neurons. Thus, α-Syn strains are determined by both misfolded seeds and intracellular environments. Discussion: Here we report that pathological α-Syn in GCIs and Lewy bodies (GCI-α-Syn and LB- α-Syn, respectively) is conformationally and biologically distinct. Furthermore, we showed that distinct α-Syn strains had no cell type preference in seeding a-Syn pathology and are generated by different intracellular milieu

In vivo effects of interferon-Γ and anti-interferon-Γ antibody on the experimentally induced lichenoid tissue reaction

We investigated the in vivo effect of recombinant interferon-Γ (IFN-Γ) and tumour necrosis factor Α (TNF-Α) treatment of mice on the development of the delayed-type hypersensitivity (DTH) reaction and lichenoid tissue reaction (LTR) following the local injection of cloned autoreactive T cells. Both the DTH reaction and the LTR were significantly enhanced by pre-treatment with IFN-Γ, but not with TNF-Ã. Induction of class II MHC antigens on keratinocytes was not essential for the enhancement by IFN-Γ. Administration of anti-IFN-Γ antibody reduced the DTH reaction and LTR, although complete inhibition was not observed with our treatment regimen. The ability of IFN-Γ to increase the number of the cloned T cells invading the epidermis in vivo , is in keeping with our previous observation that IFN-Γ treatment of cultured keratinocytes markedly increased the adherence reaction between T cells and keratinocytes in vitro.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74579/1/j.1365-2133.1988.tb03202.x.pd

A correlative and quantitative imaging approach enabling characterization of primary cell-cell communication: Case of human CD4+ T cell-macrophage immunological synapses

Cell-to-cell communication engages signaling and spatiotemporal reorganization events driven by highly context-dependent and dynamic intercellular interactions, which are difficult to capture within heterogeneous primary cell cultures. Here, we present a straightforward correlative imaging approach utilizing commonly available instrumentation to sample large numbers of cell-cell interaction events, allowing qualitative and quantitative characterization of rare functioning cell-conjugates based on calcium signals. We applied this approach to examine a previously uncharacterized immunological synapse, investigating autologous human blood CD4+ T cells and monocyte-derived macrophages (MDMs) forming functional conjugates in vitro. Populations of signaling conjugates were visualized, tracked and analyzed by combining live imaging, calcium recording and multivariate statistical analysis. Correlative immunofluorescence was added to quantify endogenous molecular recruitments at the cell-cell junction. By analyzing a large number of rare conjugates, we were able to define calcium signatures associated with different states of CD4+ T cell-MDM interactions. Quantitative image analysis of immunostained conjugates detected the propensity of endogenous T cell surface markers and intracellular organelles to polarize towards cell-cell junctions with high and sustained calcium signaling profiles, hence defining immunological synapses. Overall, we developed a broadly applicable approach enabling detailed single cell- and population-based investigations of rare cell-cell communication events with primary cells

Ligand-Receptor Interactions

The formation and dissociation of specific noncovalent interactions between a variety of macromolecules play a crucial role in the function of biological systems. During the last few years, three main lines of research led to a dramatic improvement of our understanding of these important phenomena. First, combination of genetic engineering and X ray cristallography made available a simultaneous knowledg of the precise structure and affinity of series or related ligand-receptor systems differing by a few well-defined atoms. Second, improvement of computer power and simulation techniques allowed extended exploration of the interaction of realistic macromolecules. Third, simultaneous development of a variety of techniques based on atomic force microscopy, hydrodynamic flow, biomembrane probes, optical tweezers, magnetic fields or flexible transducers yielded direct experimental information of the behavior of single ligand receptor bonds. At the same time, investigation of well defined cellular models raised the interest of biologists to the kinetic and mechanical properties of cell membrane receptors. The aim of this review is to give a description of these advances that benefitted from a largely multidisciplinar approach

Natural Killer Cell Signal Integration Balances Synapse Symmetry and Migration

Imaging immune surveillance by natural killer (NK) cells has revealed that integration of activating and inhibitory signals determines whether or not NK cells stop to kill the target cell or retain a migratory configuration

T-Cell Artificial Focal Triggering Tools: Linking Surface Interactions with Cell Response

T-cell activation is a key event in the immune system, involving the interaction of several receptor ligand pairs in a complex intercellular contact that forms between T-cell and antigen-presenting cells. Molecular components implicated in contact formation have been identified, but the mechanism of activation and the link between molecular interactions and cell response remain poorly understood due to the complexity and dynamics exhibited by whole cell-cell conjugates. Here we demonstrate that simplified model colloids grafted so as to target appropriate cell receptors can be efficiently used to explore the relationship of receptor engagement to the T-cell response. Using immortalized Jurkat T cells, we monitored both binding and activation events, as seen by changes in the intracellular calcium concentration. Our experimental strategy used flow cytometry analysis to follow the short time scale cell response in populations of thousands of cells. We targeted both T-cell receptor CD3 (TCR/CD3) and leukocyte-function-associated antigen (LFA-1) alone or in combination. We showed that specific engagement of TCR/CD3 with a single particle induced a transient calcium signal, confirming previous results and validating our approach. By decreasing anti-CD3 particle density, we showed that contact nucleation was the most crucial and determining step in the cell-particle interaction under dynamic conditions, due to shear stress produced by hydrodynamic flow. Introduction of LFA-1 adhesion molecule ligands at the surface of the particle overcame this limitation and elucidated the low TCR/CD3 ligand density regime. Despite their simplicity, model colloids induced relevant biological responses which consistently echoed whole cell behavior. We thus concluded that this biophysical approach provides useful tools for investigating initial events in T-cell activation, and should enable the design of intelligent artificial systems for adoptive immunotherapy