Hands-Free Image Capture,Data Tagging and Transfer Using Google Glass: A Pilot Study for Improved Wound Care Management

Chronic wounds, including pressure ulcers, compromise the health of 6.5 million Americans and pose an annual estimated burden of $25 billion to the U.S. health care system. When treating chronic wounds, clinicians must use meticulous documentation to determine wound severity and to monitor healing progress over time. Yet, current wound documentation practices using digital photography are often cumbersome and labor intensive. The process of transferring photos into Electronic Medical Records (EMRs) requires many steps and can take several days. Newer smartphone and tablet-based solutions, such as Epic Haiku, have reduced EMR upload time. However, issues still exist involving patient positioning, image-capture technique, and patient identification. In this paper, we present the development and assessment of the SnapCap System for chronic wound photography. Through leveraging the sensor capabilities of Google Glass, SnapCap enables hands-free digital image capture, and the tagging and transfer of images to a patient’s EMR. In a pilot study with wound care nurses at Stanford Hospital (n=16), we (i) examined feature preferences for hands-free digital image capture and documentation, and (ii) compared SnapCap to the state of the art in digital wound care photography, the Epic Haiku application. We used the Wilcoxon Signed-ranks test to evaluate differences in mean ranks between preference options. Preferred hands-free navigation features include barcode scanning for patient identification, Z(15) = -3.873, p < 0.001, r = 0.71, and double-blinking to take photographs, Z(13) = -3.606, p < 0.001, r = 0.71. In the comparison between SnapCap and Epic Haiku, the SnapCap System was preferred for sterile image-capture technique, Z(16) = -3.873, p < 0.001, r = 0.68. Responses were divided with respect to image quality and overall ease of use. The study’s results have contributed to the future implementation of new features aimed at enhancing mobile hands-free digital photography for chronic wound care.     

The orexin-1 receptor antagonist SB-334867 attenuates anxiety in rats exposed to cat odor but not the elevated plus maze: An investigation of Trial 1 and Trial 2 effects

The orexins are hypothalamic neuropeptides most well known for their roles in regulating feeding and sleeping behaviors. Recent findings suggest that orexin-A may also modulate anxiety, although how and when the orexin system is involved remains unclear. To address this, we investigated the dose-dependent effects of the orexin-1 receptor antagonist SB-334867 in two rodent models of anxiety: the cat odor avoidance model and the elevated plus maze. In both models we tested the effects of SB-334867 when anxiety is novel (Trial 1) and familiar (Trial 2). In the first experiment, Wistar rats were treated with vehicle or SB-334867 (5, 10 or 20 mg/kg, i.p.) prior to their first or second exposure to cat odor. During Trial 1, rats treated with 10 mg/kg of SB-334867 approached the cat odor stimulus more than vehicle-treated rats. During Trial 2 the effects were more marked, with 10 mg/kg of SB-334867 increasing approach times, increasing the number of times rats exited the hide box to engage in exploratory behavior, and decreasing overall hide times. In addition, the 20 mg/kg dose decreased general activity during Trial 2. In the second experiment, the effects of SB-334867 (10 and 20 mg/kg) were tested in the elevated plus maze. There were no significant differences produced by drug treatment during either Trial 1 or Trial 2. Results suggest that SB-334867 decreases anxiety induced by some, but not all, stressors.     

A colourful youth: ontogenetic colour change is habitat specific in the invasive Nile perch

External body colour is an important trait contributing to phenotypic diversity and individual fitness in fish species. In this study, we use a combination of experimental techniques and field observations to examine patterns of colour divergence in the introduced Nile perch population of Lake Nabugabo, Uganda. We aim to determine whether the proportion of black–brown body colouration of Nile perch differs over a number of size classes, across ecologically distinct wetland edge and forest edge habitats, and whether these differences are the result of rapid (physiological) or ontogenetic (morphological) colour change. We found substantial colour differences in Nile perch between habitats, but trends were not consistent across size classes. Small Nile perch (<15 cm SL) from wetland edge habitats had darker skin pigmentation than those from forest edge; however, no significant colour differences existed between medium (15–40 cm SL) and large (>40 cm SL) Nile perch. Inter-habitat differences in colour in the small size class, and shifts in colour from juvenile to adult appear to be the result of morphological colour change associated with distinct ontogenetic shifts in resource use.     

Fluorescence Resonance Energy Transfer Analysis of Merlin Conformational Changes

Neurofibromatosis type 2 is an inherited autosomal disorder caused by biallelic inactivation of the NF2 tumor suppressor gene. The NF2 gene encodes a 70-kDa protein, merlin, which is a member of the ezrin-radixin-moesin (ERM) family. ERM proteins are believed to be regulated by a transition between a closed conformation, formed by binding of their N-terminal FERM domain and C-terminal tail domain (CTD), and an open conformation, in which the two domains do not interact. Previous work suggests that the tumor suppressor function of merlin is similarly regulated and that only the closed form is active. Therefore, understanding the mechanisms that control its conformation is crucial. We have developed a series of probes that measures merlin conformation by fluorescence resonance energy transfer, both as purified protein and in live cells. Using these tools, we find that merlin exists predominately as a monomer in a stable, closed conformation that is mediated by the central α-helical domain. The contribution from the FERM-CTD interaction to the closed conformation appears to be less important. Upon phosphorylation or interaction with an effector protein, merlin undergoes a subtle conformational change, suggesting a novel mechanism that modulates the interaction between the FERM domain and the CTD.Neurofibromatosis type 2 is an inherited autosomal disorder that is characterized by bilateral schwannomas of the eighth cranial nerve. The tumor suppressor gene responsible for this disorder, NF2, was cloned in 1993 (45). Biallelic inactivation of the NF2 gene is also seen in spontaneous schwannoma, meningioma, and malignant mesothelioma (22). In mouse models, deletion of the Nf2 gene is embryonic lethal, indicating an essential role for NF2 in development (24). Heterozygous mice develop a variety of aggressive metastatic tumors that have lost the wild-type allele (23). Targeted deletion of the Nf2 gene in Schwann cells leads to schwannoma formation (7). In vitro, Nf2-null cells grow to significantly higher densities (31), suggesting that contact inhibition of growth is impaired in these cells and that mediation of growth arrest at high cell density may be the basis for the tumor suppressor function of the NF2 gene. In normal fibroblasts, merlin is inactive as a growth suppressor in subconfluent cells, becoming activated as they approach confluence, thereby effecting contact inhibition of growth (26).The NF2 gene encodes a 70-kDa protein called merlin (for moesin, ezrin, radixin-like protein), which shares significant homology with members of the ezrin-radixin-moesin (ERM) branch of the Band 4.1 superfamily (45). The domain structure of merlin, also shared with other ERM proteins, consists of an N-terminal FERM domain, followed by a central α-helical region (CH) and a C-terminal tail domain (CTD). The merlin FERM domain has relatively high sequence similarity with other ERM family members, a 60 to 70% identity over the first 300 amino acids. The CH domain and the CTD show much lower identity (28 to 36%); however, the α-helical character of the CH domain is preserved, as is the heptad repeat pattern typical of α-helices that form coiled coils (46).The critical point of regulation of all the ERM proteins is a high-affinity intramolecular interaction between the C-terminal domain and the FERM domain (4) (Fig. ​(Fig.1).1). The FERM domain folds into a three-lobed cloverleaf structure that acts as a multifaceted docking site for protein binding partners (16, 39). The CTD, consisting of four major and two minor helices and a beta sheet, binds to the FERM domain by extending across the face of the F2 and F3 lobes (32). This intramolecular head-to-tail binding results in a “closed” conformation, with the C-terminal domain covering much of the surface of the FERM domain (32, 44). For ezrin, radixin and moesin, the CTD functions as a mask, blocking access of effector molecules, such as the cell surface receptors CD44 and ICAM2 and adaptor molecules, like EBP50/NHERF, to sites on the surface of the FERM domain (11, 25, 44). The interaction between the CTD and FERM domain is regulated by phosphatidyl inositol-(4,5)-bisphosphate (PIP₂) binding to the FERM domain and by phosphorylation of a critical residue in the CTD (3, 6, 10, 49). This residue, threonine 567 in ezrin, is conserved throughout the ERM family (21). Phosphorylation introduces a negative charge and a bulky side group that effectively reduces the affinity of the interaction, releasing the CTD from the FERM domain and causing a transition to an open conformation. Low-angle rotary shadowing electron microscopy (13) and biochemical studies (12) of purified radixin suggest that in the open conformation it is an extended filamentous structure with globular N and C termini that is greater than 240 Å in length. Signal transduction systems, such as the epidermal growth factor and Rho A pathways, induce phosphorylation of ERM proteins at the conserved C-terminal threonine via a number of kinases, including Rho kinase and protein kinase Cα (21, 28). Thus, conformational regulation of ERM proteins can be a point of integration of ERM activity with signal transduction pathways. The overall concept of ERM regulation, then, is centered upon a transition between an inactive, closed conformation that is mediated by the FERM-CTD interaction and an active, open conformation that is regulated by phosphorylation. In these two states, ERM proteins likely interact with different sets of binding partners, resulting in distinct functional outcomes.Open in a separate windowFIG. 1.ERM tertiary structure as represented by the crystal structure of full-length Sf-moesin (20), but with the merlin amino acid sequence substituted for Sf-moesin. Approximate boundary amino acid residues for all domains appear at the top of the figure. Each domain is assigned a different color. The ERM structure consists of an N-terminal FERM domain folded into three lobes, F1, F2, and F3. This is followed by a central α-helical domain containing three subhelices (αA, αB, and αC) and a CTD with four short helices. An ERM protein is thought to have an open conformation, an extended structure with the FERM domain and the CTD separated by the α-helical domain, that is more than 240 Å long. In the closed conformation, the α-helical domain bends at the αA-αB junction and again at the αB-αC junction, causing the CTD to be positioned over F2 and F3 of the FERM domain. More than half of the surface of the FERM domain is masked by interaction with the CTD, αA, and parts of αB and αC.Like the classical ERMs, merlin is also thought to be regulated by changes in conformation. The FERM domain and the CTD of merlin interact with each other, albeit at a lower level of affinity than the ezrin FERM domain and the CTD (29). There are important differences, however, between merlin and the other ERM proteins. First, phosphorylation of the conserved C-tail threonine T576 has not been reported to occur in mammalian merlin, and nonphosphorylatable and phosphomimetic substitutions at this site have no effect on merlin activity (42). Instead, merlin is phosphorylated at serine 518 in the CTD, a target of the p21-activated kinase PAK and protein kinase A (1, 18, 47). The growth-suppressive function of merlin is activated by dephosphorylation of S518 by the phosphatase PP1δ in a density-dependent manner (14). Second, it was reported in a study using FERM domain and CTD truncates of merlin that only cotransfection of both the N-and C-terminal halves resulted in growth suppression (38). Together, these observations suggested a model of inactive, phosphorylated merlin in an open conformation that, upon cell-to-cell contact, is dephosphorylated and transitions to a closed, growth suppressive conformation.The existing model for conformational regulation described above is inferred from indirect data and assays that generally measure the interaction of isolated FERM and CTD truncates rather than full-length molecules (9, 29, 38). It has been impossible to test directly because tools have not been available to specifically assay for either the open or the closed form of merlin. Therefore, we have developed a series of probes that measures merlin conformation by fluorescence resonance energy transfer (FRET), both as purified protein and in live cells. Using these tools, we show that merlin exists predominately as a monomer in a stable, largely closed conformation. Additionally, we find that the closed conformation is largely mediated by the central α-helical domain; the contribution of the FERM-CTD interaction appears to be less significant than previously thought. Finally, we find that phosphorylation and protein interaction cause unexpectedly small changes in merlin conformation. We propose a new and more refined model for merlin regulation, in which merlin function is regulated by specific but subtle conformational changes that modulate the interaction between the FERM domain and the CTD.     

Identification, characterization, and expression of a unique secretory lipase from the human pathogen Leishmania donovani

Lipases have been implicated to be of importance in the life cycle development, virulence, and transmission of a variety of parasitic organisms. Potential functions include the acquisition of host resources for energy metabolism and as simple building blocks for the synthesis of complex parasite lipids important for membrane remodeling and structural purposes. Using a molecular approach, we identified and characterized the structure of an LdLip3-lipase gene from the primitive trypanosomatid pathogen of humans, Leishmania donovani. The LdLip3 encodes a ~33 kDa protein, with a well-conserved substrate-binding and catalytic domains characteristic of members of the serine lipase-protein family. Further, we showed that LdLip3 mRNA is constitutively expressed by both the insect vector (i.e., promastigote) and mammalian (i.e., amastigote) life cycle developmental forms of this protozoan parasite. Moreover, a homologous episomal expression system was used to express an HA epitope-tagged LdLip3 chimeric construct (LdLip3::HA) in these parasites. Expression of the LdLip3 chimera was verified in these transfectants by Western blots and indirect immuno-fluorescence analyses. Results of coupled immuno-affinity purification and enzyme activity experiments demonstrated that the LdLip3::HA chimeric protein was secreted/released by transfected L. donovani parasites and that it possessed functional lipase enzyme activity. Taken together these observations suggest that this novel secretory lipase might play essential role(s) in the survival, growth, and development of this important group of human pathogens.     

The quaternary structure of pyruvate kinase type 1 from Escherichia coli at low nanomolar concentrations

Pyruvate kinase (PK) is the key control point of glycolysis—the biochemical pathway central to energy metabolism and the production of precursors used in biosynthesis. PK type 1 from Escherichia coli (Ec-PK1) is activated by both fructose-1,6-bisphosphate (FBP) and its substrate, phosphoenol pyruvate (PEP). To date, it has not been possible to determine whether the enzyme is tetrameric at the low concentrations (i.e. low nM range) used to study the steady-state kinetics, or assess whether its allosteric effectors alter the oligomeric state of the enzyme at these concentrations. Employing the new technique of analytical ultracentrifugation with fluorescence detection we have, for the first time, shown that the K_D^4–2 for Ec-PK1 is in the subnanomolar range, well below the concentrations used in kinetic studies. In addition, we show that, unlike some other PK isoenzymes, the modulation of oligomeric state by the allosteric effectors FBP and PEP does not occur at a concentration of 10 nM or above.     

Color signal information content and the eye of the beholder: a case study in the rhesus macaque

Animal coloration has provided many classical examples of both natural and sexual selection. Methods to study color signals range from human assessment to models of receiver vision, with objective measurements commonly involving spectrometry or digital photography. However, signal assessment by a receiver is not objective but linked to receiver perception. Here, we use standardized digital photographs of female rhesus macaque (Macaca mulatta) face and hindquarter regions, combined with estimates of the timing of the female fertile phase, to assess how color varies with respect to this timing. We compare objective color measures (camera sensor responses) with models of rhesus vision (retinal receptor stimulation and visual discriminability). Due to differences in spectral separation between camera sensors and rhesus receptors, camera measures overestimated color variation and underestimated luminance variation compared with rhesus macaques. Consequently, objective digital camera measurements can produce statistically significant relationships that are probably undetectable to rhesus macaques, and hence biologically irrelevant, while missing variation in the measure that may be relevant. Discrimination modeling provided results that were most meaningful (as they were directly related to receiver perception) and were easiest to relate to underlying physiology. Further, this gave new insight into the function of such signals, revealing perceptually salient signal luminance changes outside of the fertile phase that could potentially enhance paternity confusion. Our study demonstrates how, even for species with similar visual systems to humans, models of vision may provide more accurate and meaningful information on the form and function of visual signals than objective color measures do.     

In vitro assessment of the antimicrobial activity of new N-acyl-thiourea derivatives

The qualitative screening of the susceptibility spectra of different microbial strains to the newly synthesized substances complexes was performed by adapted disk diffusion techniques, while the quantitative assay of the minimal inhibitory concentration (M.I.C., microg/cm3) value was based on liquid medium serial microdilutions. The compounds were solubilized in dimethylsulfoxide (DMSO). The in vitro biological screening effects were tested against a microbial inoculum of approximately 1.5 x 10(8) UFC/cm3, corresponding to 0.5 McFarland standard density, obtained from Gram positive (Staphylococcus aureus, Bacillus subtilis), Gram negative bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) and fungal strains (Candida albicans). In order to investigate the influence of the subinhibitory concentration of the tested substances on the expression of different virulence features, the strains were incubated overnight in the presence of the newly synthesized thiourea derivatives (vol:vol) and different virulence features were investigated, i.e: adherence capacity to the cellular substrate represented by HeLa cells and to inert substrata quantified by slime test and soluble enzymatic virulence factors (haemolysins and other pore-forming toxins, proteases activity, DN-ase and siderophores production). The cytotoxicity was assessed microscopically, by observing the effect of the tested compounds on the cellular substratum integrity.     

Bidirectional plasticity gated by hyperpolarization controls the gain of postsynaptic firing responses at central vestibular nerve synapses

Linking synaptic plasticity with behavioral learning requires understanding how synaptic efficacy influences postsynaptic firing in neurons whose role in behavior is understood. Here, we examine plasticity at a candidate site of motor learning: vestibular nerve synapses onto neurons that mediate reflexive movements. Pairing nerve activity with changes in postsynaptic voltage induced bidirectional synaptic plasticity in vestibular nucleus projection neurons: long-term potentiation relied on calcium-permeable AMPA receptors and postsynaptic hyperpolarization, whereas long-term depression relied on NMDA receptors and postsynaptic depolarization. Remarkably, both forms of plasticity uniformly scaled synaptic currents evoked by pulse trains, and these changes in synaptic efficacy were translated into linear increases or decreases in postsynaptic firing responses. Synapses onto local inhibitory neurons were also plastic but expressed only long-term depression. Bidirectional, linear gain control of vestibular nerve synapses onto projection neurons provides a plausible mechanism for motor learning underlying adaptation of vestibular reflexes.     

Carboxymethylated cyclodextrins and their complexes with Pr(III) and Yb(III) as water‐soluble chiral NMR solvating agents for cationic compounds

Cyclodextrins that are indiscriminately carboxymethylated at the 2‐, 3‐, and 6‐positions are used as chiral NMR solvating agents for cationic substrates with phenyl, naphthyl, pyridyl, indoline, and indole rings. Enantiodifferentiation with the α‐, β‐, and γ‐cyclodextrin derivatives is compared. The carboxymethylated derivatives are almost always more effective as chiral NMR solvating agents for cationic substrates than native cyclodextrins. The most effective carboxymethylated cyclodextrin varies for different substrates, and at times even different resonances of the substrate. Addition of paramagnetic praseodymium(III) or ytterbium(III) to mixtures of the carboxymethylated cyclodextrin and substrate often causes enhancements in enantiomeric discrimination and facilitates measurements of enantiomeric purity. The lanthanide ion bonds to the carboxymethyl groups and causes perturbations in the chemical shifts in the NMR spectra of substrate molecules in the cyclodextrin cavity. Chirality, 2010. © 2009 Wiley‐Liss, Inc.