A red-emitting carborhodamine for monitoring and measuring membrane potential

Biological membrane potentials, or voltages, are a central facet of cellular life. Optical methods to visualize cellular membrane voltages with fluorescent indicators are an attractive complement to traditional electrode-based approaches, since imaging methods can be high throughput, less invasive, and provide more spatial resolution than electrodes. Recently developed fluorescent indicators for voltage largely report changes in membrane voltage by monitoring voltage-dependent fluctuations in fluorescence intensity. However, it would be useful to be able to not only monitor changes but also measure values of membrane potentials. This study discloses a fluorescent indicator which can address both. We describe the synthesis of a sulfonated tetramethyl carborhodamine fluorophore. When this carborhodamine is conjugated with an electron-rich, methoxy (-OMe) containing phenylenevinylene molecular wire, the resulting molecule, CRhOMe, is a voltage-sensitive fluorophore with red/far-red fluorescence. Using CRhOMe, changes in cellular membrane potential can be read out using fluorescence intensity or lifetime. In fluorescence intensity mode, CRhOMe tracks fast-spiking neuronal action potentials (APs) with greater signal-to-noise than state-of-the-art BeRST 1 (another voltage-sensitive fluorophore). CRhOMe can also measure values of membrane potential. The fluorescence lifetime of CRhOMe follows a single exponential decay, substantially improving the quantification of membrane potential values using fluorescence lifetime imaging microscopy (FLIM). The combination of red-shifted excitation and emission, mono-exponential decay, and high voltage sensitivity enable fast FLIM recording of APs in cardiomyocytes. The ability to both monitor and measure membrane potentials with red light using CRhOMe makes it an important approach for studying biological voltages.

Relationship between inflammation and oxidative stress and its effect on multiple sclerosis

INTRODUCTION

This paper highlights the relationship of inflammation and oxidative stress as damage mechanisms of Multiple Sclerosis (MS), considered an inflammatory and autoimmune disease.

DEVELOPMENT

The oxidative stress concept has been defined by an imbalance between oxidants and antioxidants in favor of the oxidants. There is necessary to do physiological functions, like the respiration chain, but in certain conditions, the production of reactive species overpassed the antioxidant systems, which could cause tissue damage. On the other hand, it is well established that inflammation is a complex reaction in the vascularized connective tissue in response to diverse stimuli. However, an unregulated prolonged inflammatory process also can induce tissue damage.

CONCLUSION

Both inflammation and oxidative stress are interrelated since one could promote the other, leading to a toxic feedback system, which contributes to the inflammatory and demyelination process in MS.

Identifying ligands for the PHD1 finger of KDM5A through high-throughput screening

PHD fingers are a type of chromatin reader that primarily recognize chromatin as a function of lysine methylation state. Dysregulated PHD fingers are implicated in various human diseases, including acute myeloid leukemia. Targeting PHD fingers with small molecules is considered challenging as their histone tail binding pockets are often shallow and surface-exposed. The KDM5A PHD1 finger regulates the catalytic activity of KDM5A, an epigenetic enzyme often misregulated in cancers. To identify ligands that disrupt the PHD1-histone peptide interaction, we conducted a high-throughput screen and validated hits by orthogonal methods. We further elucidated structure-activity relationships in two classes of compounds to identify features important for binding. Our investigation offers a starting point for further optimization of small molecule PHD1 ligands.

A red-emitting carborhodamine for monitoring and measuring membrane potential

Biological membrane potentials, or voltages, are a central facet of cellular life. Optical methods to visualize cellular membrane voltages with fluorescent indicators are an attractive complement to traditional electrode-based approaches, since imaging methods can be high throughput, less invasive, and provide more spatial resolution than electrodes. Recently developed fluorescent indicators for voltage largely report changes in membrane voltage by monitoring voltage-dependent fluctuations in fluorescence intensity. However, it would be useful to be able to not only monitor changes, but also measure values of membrane potentials. This study discloses a new fluorescent indicator which can address both. We describe the synthesis of a new sulfonated tetramethyl carborhodamine fluorophore. When this carborhodamine is conjugated with an electron-rich, methoxy (-OMe) containing phenylenevinylene molecular wire, the resulting molecule, CRhOMe, is a voltage-sensitive fluorophore with red/far-red fluorescence. Using CRhOMe, changes in cellular membrane potential can be read out using fluorescence intensity or lifetime. In fluorescence intensity mode, CRhOMe tracks fast-spiking neuronal action potentials with greater signal-to-noise than state-of-the-art BeRST (another voltage-sensitive fluorophore). CRhOMe can also measure values of membrane potential. The fluorescence lifetime of CRhOMe follows a single exponential decay, substantially improving the quantification of membrane potential values using fluorescence lifetime imaging microscopy (FLIM). The combination of red-shifted excitation and emission, mono-exponential decay, and high voltage sensitivity enable fast FLIM recording of action potentials in cardiomyocytes. The ability to both monitor and measure membrane potentials with red light using CRhOMe makes it an important approach for studying biological voltages.

Chemical tools targeting readers of lysine methylation

Reader domains that recognize methylated lysine and arginine residues on histones play a role in the recruitment, stabilization, and regulation of chromatin regulatory proteins. Targeting reader proteins with small molecule and peptidomimetic inhibitors has enabled the elucidation of the structure and function of specific domains and uncovered their role in diseases. Recent progress towards chemical probes that target readers of lysine methylation, including the Royal family and plant homeodomains (PHD), is discussed here. We highlight recently developed covalent cyclic peptide inhibitors of a plant homeodomain. Additionally, inhibitors targeting previously untargeted Tudor domains and chromodomains are discussed.

Multimodal control of dendritic cell functions by nociceptors

It is known that interactions between nociceptors and dendritic cells (DCs) can modulate immune responses in barrier tissues. However, our understanding of the underlying communication frameworks remains rudimentary. Here, we show that nociceptors control DCs in three molecularly distinct ways. First, nociceptors release the calcitonin gene-related peptide that imparts a distinct transcriptional profile on steady-state DCs characterized by expression of pro-interleukin-1β and other genes implicated in DC sentinel functions. Second, nociceptor activation induces contact-dependent calcium fluxes and membrane depolarization in DCs and enhances their production of proinflammatory cytokines when stimulated. Finally, nociceptor-derived chemokine CCL2 contributes to the orchestration of DC-dependent local inflammation and the induction of adaptive responses against skin-acquired antigens. Thus, the combined actions of nociceptor-derived chemokines, neuropeptides, and electrical activity fine-tune DC responses in barrier tissues.

Correlation and validity of imputed PaO2/FiO2 and SpO2/FiO2 in patients with invasive mechanical ventilation at 2600m above sea level

OBJECTIVE

To establish the correlation and validity between PaO2/FiO2 obtained on arterial gases versus noninvasive methods (linear, nonlinear, logarithmic imputation of PaO2/FiO2 and SpO2/FiO2) in patients under mechanical ventilation living at high altitude.

DESIGN

Ambispective descriptive multicenter cohort study.

SETTING

Two intensive care units (ICU) from Colombia at 2600m a.s.l.

PATIENTS OR PARTICIPANTS

Consecutive critically ill patients older than 18 years with at least 24h of mechanical ventilation were included from June 2016 to June 2019.

INTERVENTIONS

None.

VARIABLES

Variables analyzed were demographic, physiological messures, laboratory findings, oxygenation index and clinical condition. Nonlinear, linear and logarithmic imputation formulas were used to calculate PaO2 from SpO2, and at the same time the SpO2/FiO2 by severe hypoxemia diagnosis. The intraclass correlation coefficient, area under the ROC curve, sensitivity, specificity, positive predictive value, negative predictive value, positive and negative likelihood ratio were calculated.

RESULTS

The correlation between PaO2/FiO2 obtained from arterial gases, PaO2/FiO2 derived from one of the proposed methods (linear, non-linear, and logarithmic formula), and SpO2/FiO2 measured by the intraclass correlation coefficient was high (greater than 0.77, p<0.001). The different imputation methods and SpO2/FiO2 have a similar diagnostic performance in patients with severe hypoxemia (PaO2/FiO2 <150). PaO2/FiO2 linear imputation AUC ROC 0,84 (IC 0.81-0.87, p<0.001), PaO2/FiO2 logarithmic imputation AUC ROC 0.84 (IC 0.80-0.87, p<0.001), PaO2/FiO2 non-linear imputation AUC ROC 0.82 (IC 0.79-0.85, p<0.001), SpO2/FiO2 oximetry AUC ROC 0.84 (IC 0.81-0.87, p<0.001).

CONCLUSIONS

At high altitude, the SaO2/FiO2 ratio and the imputed PaO2/FiO2 ratio have similar diagnostic performance in patients with severe hypoxemia ventilated by various pathological conditions.

Covalent labeling of a chromatin reader domain using proximity-reactive cyclic peptides

Chemical probes for chromatin reader proteins are valuable tools for investigating epigenetic regulatory mechanisms and evaluating whether the target of interest holds therapeutic potential. Developing potent inhibitors for the plant homeodomain (PHD) family of methylation readers remains a difficult task due to the charged, shallow and extended nature of the histone binding site that precludes effective engagement of conventional small molecules. Herein, we describe the development of novel proximity-reactive cyclopeptide inhibitors for PHD3—a trimethyllysine reader domain of histone demethylase KDM5A. Guided by the PHD3–histone co-crystal structure, we designed a sidechain-to-sidechain linking strategy to improve peptide proteolytic stability whilst maintaining binding affinity. We have developed an operationally simple solid-phase macrocyclization pathway, capitalizing on the inherent reactivity of the dimethyllysine ε-amino group to generate scaffolds bearing charged tetraalkylammonium functionalities that effectively engage the shallow aromatic ‘groove’ of PHD3. Leveraging a surface-exposed lysine residue on PHD3 adjacent to the ligand binding site, cyclic peptides were rendered covalent through installation of an arylsulfonyl fluoride warhead. The resulting lysine-reactive cyclic peptides demonstrated rapid and efficient labeling of the PHD3 domain in HEK293T lysates, showcasing the feasibility of employing proximity-induced reactivity for covalent labeling of this challenging family of reader domains.

We describe the development of covalent cyclic peptide ligands which target a chromatin methylation reader domain using a proximity-reactive sulfonyl fluoride moiety.

A silicon-rhodamine chemical-genetic hybrid for far red voltage imaging from defined neurons in brain slice

We describe the design, synthesis, and application of voltage-sensitive silicon rhodamines. Based on the Berkeley Red Sensor of Transmembrane potential, or BeRST, scaffold, the new dyes possess an isomeric molecular wire for improved alignment in the plasma membrane and 2′ carboxylic acids for ready functionalization. The new isoBeRST dyes have a voltage sensitivity of 24% ΔF/F per 100 mV. Combined with a flexible polyethyleneglycol (PEG) linker and a chloroalkane HaloTag ligand, isoBeRST dyes enable voltage imaging from genetically defined cells and neurons and provide improved labeling over previous, rhodamine-based hybrid strategies. isoBeRST-Halo hybrid indicators achieve single-trial voltage imaging of membrane potential dynamics from cultured hippocampal neurons or cortical neurons in brain slices. With far-red/near infrared excitation and emission, turn-on response to action potentials, and effective cell labeling in thick tissue, the new isoBeRST-Halo derivatives provide an important complement to voltage imaging in neurobiology.

Small-molecule enzyme hybrids pair a far-red voltage-sensitive fluorophore with a cell-surface expressed HaloTag enzyme via a flexible linker to enable voltage imaging from genetically defined neurons in culture and brain slice.

Correlation and validity of imputed PaO2/FiO2 and SpO2/FiO2 in patients with invasive mechanical ventilation at 2600m above sea level

OBJECTIVE

To establish the correlation and validity between PaO2/FiO2 obtained on arterial gases versus noninvasive methods (linear, nonlinear, logarithmic imputation of PaO2/FiO2 and SpO2/FiO2) in patients under mechanical ventilation living at high altitude.

DESIGN

Ambispective descriptive multicenter cohort study.

SETTING

Two intensive care units (ICU) from Colombia at 2600m a.s.l.

PATIENTS OR PARTICIPANTS

Consecutive critically ill patients older than 18 years with at least 24h of mechanical ventilation were included from June 2016 to June 2019.

INTERVENTIONS

None.

VARIABLES

Variables analyzed were demographic, physiological messures, laboratory findings, oxygenation index and clinical condition. Nonlinear, linear and logarithmic imputation formulas were used to calculate PaO2 from SpO2, and at the same time the SpO2/FiO2 by severe hypoxemia diagnosis. The intraclass correlation coefficient, area under the ROC curve, sensitivity, specificity, positive predictive value, negative predictive value, positive and negative likelihood ratio were calculated.

RESULTS

The correlation between PaO2/FiO2 obtained from arterial gases, PaO2/FiO2 derived from one of the proposed methods (linear, non-linear, and logarithmic formula), and SpO2/FiO2 measured by the intraclass correlation coefficient was high (greater than 0.77, p<0.001). The different imputation methods and SpO2/FiO2 have a similar diagnostic performance in patients with severe hypoxemia (PaO2/FiO2 <150). PaO2/FiO2 linear imputation AUC ROC 0,84 (IC 0.81-0.87, p<0.001), PaO2/FiO2 logarithmic imputation AUC ROC 0.84 (IC 0.80-0.87, p<0.001), PaO2/FiO2 non-linear imputation AUC ROC 0.82 (IC 0.79-0.85, p<0.001), SpO2/FiO2 oximetry AUC ROC 0.84 (IC 0.81-0.87, p<0.001).

CONCLUSIONS

At high altitude, the SaO2/FiO2 ratio and the imputed PaO2/FiO2 ratio have similar diagnostic performance in patients with severe hypoxemia ventilated by various pathological conditions.

A high-affinity, partial antagonist effect of 3,4-diaminopyridine mediates action potential broadening and enhancement of transmitter release at NMJs

3,4-Diaminopyridine (3,4-DAP) increases transmitter release from neuromuscular junctions (NMJs), and low doses of 3,4-DAP (estimated to reach ∼1 μM in serum) are the Food and Drug Administration (FDA)-approved treatment for neuromuscular weakness caused by Lambert–Eaton myasthenic syndrome. Canonically, 3,4-DAP is thought to block voltage-gated potassium (Kv) channels, resulting in prolongation of the presynaptic action potential (AP). However, recent reports have shown that low millimolar concentrations of 3,4-DAP have an off-target agonist effect on the Cav1 subtype (“L-type”) of voltage-gated calcium (Cav) channels and have speculated that this agonist effect might contribute to 3,4-DAP effects on transmitter release at the NMJ. To address 3,4-DAP’s mechanism(s) of action, we first used the patch-clamp electrophysiology to characterize the concentration-dependent block of 3,4-DAP on the predominant presynaptic Kv channel subtypes found at the mammalian NMJ (Kv3.3 and Kv3.4). We identified a previously unreported high-affinity (1–10 μM) partial antagonist effect of 3,4-DAP in addition to the well-known low-affinity (0.1–1 mM) antagonist activity. We also showed that 1.5-μM DAP had no effects on Cav1.2 or Cav2.1 current. Next, we used voltage imaging to show that 1.5- or 100-μM 3,4-DAP broadened the AP waveform in a dose-dependent manner, independent of Cav1 calcium channels. Finally, we demonstrated that 1.5- or 100-μM 3,4-DAP augmented transmitter release in a dose-dependent manner and this effect was also independent of Cav1 channels. From these results, we conclude that low micromolar concentrations of 3,4-DAP act solely on Kv channels to mediate AP broadening and enhance transmitter release at the NMJ.

Bioelectrical domain walls in homogeneous tissues

Electrical signaling in biology is typically associated with action potentials, transient spikes in membrane voltage that return to baseline. Hodgkin-Huxley and related conductance-based models of electrophysiology belong to a more general class of reaction-diffusion equations which could, in principle, support spontaneous emergence of patterns of membrane voltage which are stable in time but structured in space. Here we show theoretically and experimentally that homogeneous or nearly homogeneous tissues can undergo spontaneous spatial symmetry breaking through a purely electrophysiological mechanism, leading to formation of domains with different resting potentials separated by stable bioelectrical domain walls. Transitions from one resting potential to another can occur through long-range migration of these domain walls. We map bioelectrical domain wall motion using all-optical electrophysiology in an engineered cell line and in human induced pluripotent stem cell (iPSC)-derived myoblasts. Bioelectrical domain wall migration may occur during embryonic development and during physiological signaling processes in polarized tissues. These results demonstrate that nominally homogeneous tissues can undergo spontaneous bioelectrical symmetry breaking.

Unveiling contextual realities by microscopically entangling a neutron

The development of qualitatively new measurement capabilities is often a prerequisite for critical scientific and technological advances. Here we introduce an unconventional quantum probe, an entangled neutron beam, where individual neutrons can be entangled in spin, trajectory and energy. The spatial separation of trajectories from nanometers to microns and energy differences from peV to neV will enable investigations of microscopic magnetic correlations in systems with strongly entangled phases, such as those believed to emerge in unconventional superconductors. We develop an interferometer to prove entanglement of these distinguishable properties of the neutron beam by observing clear violations of both Clauser-Horne-Shimony-Holt and Mermin contextuality inequalities in the same experimental setup. Our work opens a pathway to a future of entangled neutron scattering in matter.

Exploring correlations in strongly entangled quantum materials is of interest. Here the authors generate a tunable spin-, trajectory-, and energy-entangled neutron beam using a neutron spin-echo interferometer and show violations of Clauser-Horne-Shimony-Holt and Mermin contextuality inequalities with micron-scale trajectory separation.

[Posttraumatic growth in parents of children and adolescents with cancer]

Cancer can provoke negative psychological reactions. Nevertheless, coping with oncological issues can also result in positive psychological changes that demonstrate the strength of the human being, one of them being posttraumatic growth (PTG). The aim of this narrative review was to examine and analyze studies, published from 2000 to 2018 and available in different data sets, that focus on PTG in parents of children and adolescents with cancer in the pediatric context. Twenty studies were identified, including 2,422 subjects, mainly mothers (n=1,788). PTG was analyzed according to the differences among relatives, outcome and type of oncological disease, and its predictor factors. Fathers and mothers are both capable of developing PTG as a result of their children's disease, mothers being the ones who present higher levels. Compared with other samples like parents of children with type I diabetes or healthy children, or adult patients with osteosarcoma, parents of children with cancer present more PTG. Likewise, factors that influence the development of PTG, such as cultural context, cognitive processing, adjustment to the disease and certain personality traits are observed. The published clinical evidence endorses the existence of PTG in parents of children with cancer. However, it would be necessary to carry out further investigation, particularly subjective and longitudinal studies with larger homogeneous samples, in order to design interventions aimed at promoting PTG and avoid focusing solely on the negative aspects of oncological disease in children.

Synthesis of Sulfonated Carbofluoresceins for Voltage Imaging

We present the design, synthesis, and applications of a new class of voltage-sensitive fluorescent indicators built on a modified carbofluorescein scaffold. Carbofluoresceins are an attractive target for responsive probes because they maintain oxygen substitution patterns at the 3' and 6' positions, similar to fluorescein, while simultaneously possessing excitation and emission profiles red-shifted nearly 50 nm compared to fluorescein. However, the high p K_a of carbofluorescein dyes, coupled with their tendency to cyclize to nonfluorescent configurations, precludes their use in voltage-imaging applications. Here, we overcome the limitations of carbofluoresceins via chlorination to lower the p K_a by 2 units to 5.2 and sulfonation to prevent cyclization to the nonabsorbing form. To achieve this, we devise a synthetic route to halogenated sulfonated carbofluoresceins from readily available, inexpensive starting materials. New, chlorinated sulfone carbofluoresceins have low p K_a values (5.2) and can be incorporated into phenylenevinylene molecular wire scaffolds to create carboVoltage-sensitive fluorophores (carboVF dyes). The best of the new carboVF dyes, carboVF2.1(OMe).Cl, possesses excitation and emission profiles of >560 nm, displays high voltage sensitivity (>30% Δ F/ F per 100 mV), and can be used in the presence of other blue-excited fluorophores such as green fluorescent protein. Because carboVF2.1(OMe).Cl contains a phenolic oxygen, it can be incorporated into fluorogenic labeling strategies. Alkylation with a sterically bulky cyclopropylmethyl-derived acetoxymethyl ether renders carboVF weakly fluorescent; we show that fluorescence can be restored by the action of porcine liver esterase both in vitro and on the surface of living cells and neurons. Together, these results suggest chlorinated sulfone carbofluoresceins can be promising candidates for hybrid chemical-genetic voltage imaging at wavelengths beyond typical fluorescein excitation and emission.

Headache at the emergency room: Etiologies, diagnostic usefulness of the ICHD 3 criteria, red and green flags

INTRODUCTION

Non-traumatic headaches account for 0.5 to 4.5% at the emergency department (ED). Although primary headaches represent the most common causes, the likelihood of ominous etiology has to be considered by clinicians in order to avoid diagnostic and therapeutic pitfalls. Due to the absence of biological or imaging findings to diagnose primary headaches we hypothesize ICHD 3(International Headache criteria 3) criteria as a useful tool at the moment to identify and to establish a difference between those patients who are undergoing primary headaches and those who will need advanced diagnostic strategies.

OBJECTIVES

To determine the usefulness of ICHD 3 criteria to differentiate primary from non-primary headaches at the emergency department (ED).

METHODS

During five weeks all the patients complaining of headache attended at the triage unit at the ED were interviewed, examined and classified as having primary or non-primary headaches by means of ICHD 3 criteria. Those patients with primary headaches were treated according to standard of care protocols and followed up by means of phone call communication after 48 hours to assure satisfactory outcome. Those patients classified as having non-primary headaches (secondary headaches and neuralgias) were admitted for additional diagnostic and therapeutic interventions. Between both groups we compared the prevalence of fulfilled criteria for primary headaches and the proportion of traditional red flags such as age, sleep headache onset, associated symptoms, abnormal neurological exam, sudden onset, and nonresponse to analgesics in addition to previous consultation before this evaluation.

RESULTS

Headache was responsible for 244 (2.3%) out of 10450 admissions at the ED, 77.8% were females. Primary, non-primary (secondary plus neuralgias) and unclassified headaches were 59.4%, 32% and 8.6% respectively. Migraine and cervical myofascial pain were the most frequent etiologies for primary and non-primary causes respectively. Factors associated to non-primary etiologies were immunosuppression (OR: 2.7 IC 95% 2.3-3.3) and age older than 50 (OR: 2.7 IC 95% 2.01-3.62). Abnormal neurological exam, sudden and sleep headache onset were not statistically significant. Factors found to be associated with primary headaches were: fulfilling ICHD 3 criteria (OR: 18.7, IC95% 7.1-48.6), history of migraine (OR: 2.9 IC 95% 2.1-3.9), and history of similar episodes (OR: 2.7 IC 95% 2.3-3.3).

CONCLUSION

This data suggests that fulfilling ICHD 3 criteria could be useful to differentiate primary from non-primary headaches. This observation is also valid for immunosuppression, age older than 50, history of migraine and history of similar episodes.

Impact and safety of open lung biopsy in patients with acute respiratory distress syndrome (ARDS)

INTRODUCTION

Acute respiratory distress syndrome (ARDS) is an inflammatory lung disorder, and its pathological hallmark is diffuse alveolar damage (DAD). Given that open lung biopsy (OLB) can sometimes result in severe side effects, it is rarely performed in patients with ARDS.

AIM

The aims of this study were to describe: (a) the rate of treatment change associated with the histological result; and (b) the incidence of side effects induced by OLB.

DESIGN AND PATIENTS

A retrospective, single-center, descriptive observational study was carried out in Hospital Santa Clara (Bogotá, Colombia) from February 2007 to January 2014.

INCLUSION CRITERIA

Critically ill patients over 18 years of age, undergoing invasive mechanical ventilation, diagnosed with ARDS of unknown etiology, and with OLB performed at the bedside. ARDS was diagnosed according to the Berlin definition. DAD was defined by the presence of a hyaline membrane plus at least one of the following: intra-alveolar edema, alveolar type I cell necrosis, alveolar type II cell (cuboidal cells) proliferation progressively covering the denuded alveolar-capillary membrane, interstitial proliferation of fibroblasts and myofibroblasts, or organizing interstitial fibrosis. The rate of treatment change (RTC) was established according to whether the OLB pathology report resulted in: a) the prescription or discontinuation of an antimicrobial; b) the indication of new procedures; c) medical interconsultation; or d) limitation of therapeutic effort. Patients were followed-up until death or hospital discharge. This study was approved by the Ethics Committee.

RESULTS

A total of 32 OLBs were performed during the study period; 17 were ruled out as they did not involve ARDS, and 15 were considered for further analysis. A histological diagnosis was reached in 14 of the 15 patients (12 DAD, one case of bronchiolitis obliterans organizing pneumonia and one case of Wegener's granulomatosis with alveolar hemorrhage). The RTC rate was 0.73. The most frequent intervention was discontinuation of antimicrobial or corticosteroid treatment. No deaths but four side effects (3 airway leaks and one hemothorax) were associated with the OLB procedure. All were resolved before ICU discharge.

CONCLUSION

The information provided by OLB performed at the bedside in ARDS patients of unknown etiology could be relevant, as it may optimize treatment. The risk associated with OLB seems to be acceptable.

Implementation of an advance directive focus in a Chronic Multi-Organ Rare Disease Clinic

BACKGROUND

Education about an advance directive is frequently not addressed in the outpatient, ambulatory care setting. The objective of this study was to identify patients that do not have an advance directive in a Chronic Multi-Organ Rare Disease Clinic model, and define the role of a social worker in providing advance care planning (ACP).

METHODS

The Chronic Multi-Organ Rare Disease Clinic in-corporates a multi-disciplinary team to provide outpatient care to over 600 patients. A review of advance directives filed in the electronic health record (EHR) prior to hiring a clinic social worker was examined in this high risk population.

RESULTS

A total of 15 patients (2%) of this patient population were identified as having a completed, active advance directive filed with their EHR prior to hiring a clinic social worker. The clinic social worker began ACP discussions and inquiries about the status of patient advance directives with a total of 162 patients during September 2016-April 2017. Of these 162 patients, 14 patients (8.6%) submitted their completed advance directives for filing with their EHR after advanced care discussions were initiated by the clinic social worker. Two patients who completed an advance directive, died during this 7-month time period. Only three patients declined to complete advance directives during this same time period.

CONCLUSIONS

Patient-centered care must incorporate ACP. A clinic social worker is an effective member of a multi-disciplinary team and can incorporate education about advance directives in order to improve health care quality.

Chronic Multiorgan Rare Disease: The Role of the Nurse Practitioner as a Leader of the Healthcare Team

Value in healthcare must focus on accessibility, quality, and affordability. This article describes how a healthcare team provides value by meeting the needs of a rare disease patient and underscores the importance of a chronic multiorgan rare disease home. A nurse practitioner can ensure that barriers to evaluation are removed and communication is prioritized in order to provide accessible and affordable care to a patient with rare disease without jeopardizing quality of care.

Evaluation of a Community-Based Latino Heart Disease Prevention Program in Metropolitan Washington D.C

Cardiovascular disease (CVD) is the leading cause of death for Latinos living in the United States. This population is generally unaware of important lifestyle or behavioral changes that can prevent CVD. The National Heart, Lung, and Blood Institute (NHLBI) in collaboration with a community alliance designed and implemented Salud para su Corazón (Health for Your Heart), a culturally specific, community-based initiative to increase awareness about heart disease risk factors and knowledge about heart disease prevention, and to promote heart-healthy lifestyles. The initiative included messages about smoking cessation; weight loss if overweight; increase in physical activity; and checking blood pressure and cholesterol and treating them if high. Messages were communicated through multiple mass media, interpersonal, and outreach channels. A summative evaluation assessed the impact of the campaign. A pre- and post-campaign survey was conducted in the intervention community to assess whether the messages reached the target audience, and if the initiative had an effect. The sample of respondents included over 300 participants. Results showed that respondents were significantly more aware of risk factors for CVD after the campaign, and had greatly increased their knowledge of ways to prevent heart disease. Current behaviors to prevent cardiovascular disease had not changed at the post campaign measurement. Television, radio, and doctors were the most frequently cited sources of information for learning about the Salud para su Corazón initiative. Furthermore, the specific messages recalled and the source of information cited at post-test were similar to those promoted in the campaign, indicating it was successful in reaching the target audience.

Electrochemical and chemical insertion/deinsertion of magnesium in spinel-type MgMn2O4 and lambda-MnO2 for both aqueous and non-aqueous magnesium-ion batteries

A veritable magnesium-ion battery is described. Magnesium-ion can be reversibly extracted from MgMn₂O₄ and reversibly inserted into lambda-MnO₂.

Composite fermion-boson mapping for fermionic lattice models

We present a mapping of elementary fermion operators onto a quadratic form of composite fermionic and bosonic cluster operators. The mapping is an exact isomorphism as long as the physical constraint of one composite particle per cluster is satisfied. This condition is treated on average in a composite particle mean-field approach, which consists of an ansatz that decouples the composite fermionic and bosonic sectors. The theory is tested on the 1D and 2D Hubbard models. Using a Bogoliubov determinant for the composite fermions and either a coherent or Bogoliubov state for the bosons, we obtain a simple and accurate procedure for treating the Mott insulating phase of the Hubbard model with mean-field computational cost.

Knowledge and behavioral effects in cardiovascular health: Community Health Worker Health Disparities Initiative, 2007-2010

Introduction

Cardiovascular disease is the leading cause of death in the United States, and disparities in cardiovascular health exist among African Americans, American Indians, Hispanics, and Filipinos. The Community Health Worker Health Disparities Initiative of the National Heart, Lung, and Blood Institute (NHLBI) includes culturally tailored curricula taught by community health workers (CHWs) to improve knowledge and heart-healthy behaviors in these racial/ethnic groups.

Methods

We used data from 1,004 community participants in a 10-session curriculum taught by CHWs at 15 sites to evaluate the NHLBI’s health disparities initiative by using a 1-group pretest–posttest design. The curriculum addressed identification and management of cardiovascular disease risk factors. We used linear mixed effects and generalized linear mixed effects models to examine results.

Results

Average participant age was 48; 75% were female, 50% were Hispanic, 35% were African American, 8% were Filipino, and 7% were American Indian. Twenty-three percent reported a history of diabetes, and 37% reported a family history of heart disease. Correct pretest to posttest knowledge scores increased from 48% to 74% for heart healthy knowledge. The percentage of participants at the action or maintenance stage of behavior change increased from 41% to 85%.

Conclusion

Using the CHW model to implement community education with culturally tailored curricula may improve heart health knowledge and behaviors among minorities. Further studies should examine the influence of such programs on clinical risk factors for cardiovascular disease.

The making of expert clinicians: reflective practice

Debriefing is a rigorous reflection process which helps trainees recognize and resolve clinical and behavioral dilemmas raised by a clinical case. This approach emphasizes eliciting trainees'assumptions about the situation and their reasons for performing as they did (mental models). It analyses their impact on actions, to understand if it is necessary to maintain them or construct new ones that may lead to better performance in the future. It blends evidence and theory from education research, the social and cognitive sciences, and experience drawn from conducting and teaching debriefing to clinicians worldwide, on how to improve professional effectiveness through "reflective practice".

Superconductivity in strongly repulsive fermions: the role of kinetic-energy frustration

We discuss a physical mechanism of a non-BCS nature which can stabilize a superconducting state in a strongly repulsive electronic system. By considering the two-dimensional Hubbard model with spatially modulated electron hoppings, we demonstrate how kinetic-energy frustration can lead to robust d-wave superconductivity at arbitrarily large on-site repulsion. This phenomenon should be observable in experiments using fermionic atoms, e.g. 40K, in specially prepared optical lattices.

Unified approach to quantum and classical dualities

We show how classical and quantum dualities, as well as duality relations that appear only in a sector of certain theories (emergent dualities), can be unveiled, and systematically established. Our method relies on the use of morphisms of the bond algebra of a quantum Hamiltonian. Dualities are characterized as unitary mappings implementing such morphisms, whose even powers become symmetries of the quantum problem. Dual variables, which have been guessed in the past, can be derived in our formalism. We obtain new self-dualities for four-dimensional Abelian gauge field theories.

The phase diagram of the Heisenberg antiferromagnet with four-spin interactions

We study the quantum phase diagram of the Heisenberg planar antiferromagnet with a subset of four-spin ring exchange interactions, using the recently proposed hierarchical mean-field approach. By identifying relevant degrees of freedom, we are able to use a single variational ansatz to map the entire phase diagram of the model and uncover the nature of its various phases. It is shown that there exists a transition between a Néel state and a quantum paramagnetic phase, characterized by broken translational invariance. The non-magnetic phase preserves the lattice rotational symmetry, and has a correlated plaquette nature. Our results also suggest that this phase transition can be properly described within the Landau paradigm.

Field-induced orbital antiferromagnetism in mott insulators

We report on a new electromagnetic phenomenon that emerges in Mott insulators. The phenomenon manifests as antiferromagnetic ordering due to orbital electric currents which are spontaneously generated from the coupling between spin currents and an external homogenous magnetic field. This novel spin-charge-current effect provides the mechanism to measure the so-far elusive spin currents by means of unpolarized neutron scattering, nuclear magnetic resonance or muon spectroscopy. We illustrate this mechanism by solving a half-filled Hubbard model on a frustrated ladder.

Local physics of magnetization plateaux in the Shastry-Sutherland model

We address the physical mechanism responsible for the emergence of magnetization plateaux in the Shastry-Sutherland model. By using a hierarchical mean-field approach, we demonstrate that a plateau is stabilized in a certain spin pattern, satisfying local commensurability conditions derived from our formalism. Our results provide evidence in favor of a robust local physics nature of the plateaux states and are in agreement with recent NMR experiments on SrCu2(BO3)2.

[Risk factors associated with the presence of pneumonia in patients with brain injury]

INTRODUCTION

Pneumonia in patients with head trauma occurs commonly; however, few data are available to evaluate the effects of the infection on the prognosis.

OBJECTIVE

The incidence and microbiological findings were described, and the associated risk factors were established with the appearance of pneumonia in patients with severe brain trauma.

MATERIALS AND METHODS

A prospective cohort study was conducted that included 39 patients with severe brain trauma and who required mechanical ventilation; initially, none had pneumonia. These patients were observed during a 24-month period in an attempt to discern the principal risk factors associated with the onset of pneumonia.

RESULTS

Pneumonia occurred in 31 (80%) of the 39 patients, and 28 of these presented early pneumonia. The most frequent germ in patients with pneumonia was Staphylococcus aureus with a percentage of the 42.4%. In the multivariate analysis, the single statistically significant risk factor was the presence of hypotension and vasopressor support with a RR = 27.9 (95% CI = 1.0-749.9, p < 0.05). No significant differences in the days of mechanical ventilation or mortality in both groups. The major mortality-associated risk factor in patients with pneumonia was a low Glasgow score at admittance with an OR = 2.19 (95% CI 1.03 - 4.65), p < 0.05.

CONCLUSIONS

The incidence of pneumonia in patients with severe brain trauma is high; however, its appearance does not affect the prognosis. The single significant risk factor was the presence of hypotension and vasopressor support.

Ferrotoroidic moment as a quantum geometric phase

We present a geometric characterization of the ferrotoroidic moment tau in terms of a set of Abelian Berry phases. We also introduce a fundamental complex quantity z munu, which provides an alternative way to calculate tau and its moments and is derived from the tensor T munu=2 under summation operator jrj muSj nu. This geometric framework defines a natural computational approach for density functional and many-body theories.

Modeling human respiratory impedance in Hispanic asthmatic children

Central (large airway) and peripheral (small airway) dysfunction frequently occur in patients with asthma and chronic obstructive lung disease. Measurement of the respiratory impedance can assist with diagnosis of pathological conditions. The forced Oscillation technique (FOT) superimposes small pressure perturbations at the mouth during tidal breathing of a subject to measure lung mechanical parameters. The Impulse Oscillometry System (IOS) is a commercial instrument that measures forced oscillatory impedance. IOS can be conveniently used in children as it only requires their passive cooperation during pulmonary function testing. Forced oscillatory impedance can be analyzed with respiratory system equivalent electrical circuit models. Models of varying complexity and fidelity have been developed to provide better understanding of respiratory mechanics and enable greater specificity of the diagnosis. Parameter estimates for these models can be used as reference values for detection and diagnosis of different respiratory pathologies. Previous work by our group has evaluated several known respiratory models and a new RIC model (augmented RIC) has emerged which offers advantages over earlier models. It has been shown that one parameter of this new model (representing peripheral airway compliance) is capable of discriminating between normal and asthmatic children. In this paper, we analyzed IOS data from 40 Hispanic asthmatic children and obtained sensitive impulse oscillometric parameters of lung function as well as parameter estimates for the augmented RIC (aRIC) model to distinguish between constricted (asthmatic condition) and non-constricted (non-asthmatic condition) airways with very promising results.

Quantum approach to classical statistical mechanics

We present a new approach to study the thermodynamic properties of d-dimensional classical systems by reducing the problem to the computation of ground state properties of a d-dimensional quantum model. This classical-to-quantum mapping allows us to extend the scope of standard optimization methods by unifying them under a general framework. The quantum annealing method is naturally extended to simulate classical systems at finite temperatures. We derive the rates to assure convergence to the optimal thermodynamic state using the adiabatic theorem of quantum mechanics. For simulated and quantum annealing, we obtain the asymptotic rates of T(t) approximately (pN)/(k(B)logt) and gamma(t) approximately (Nt)(-c/N), for the temperature and magnetic field, respectively. Other annealing strategies are also discussed.

Mechanisms of ischemic stroke in HIV-infected patients

OBJECTIVE

To evaluate the types and mechanisms of stroke in a large population of HIV-infected patients.

METHODS

We reviewed records of consecutive HIV-infected patients with acute stroke admitted to a large metropolitan hospital between 1996 and 2004. Stroke mechanism was defined by consensus between two cerebrovascular neurologists using TOAST classification.

RESULTS

A total of 82 patients were included, 77 with ischemic stroke and 5 with intracerebral hemorrhage. Mean age was 42 years and 89% were African American. Previous diagnosis of HIV infection was documented in 91% and AIDS diagnosis in 80%. Mean CD4 count was 113 cells/mm(3) and 85% had CD4 count <200 cells/mm(3). A total of 61% of patients had received combination antiretroviral treatment (CART). The mechanism of ischemic stroke was large artery atherosclerosis in 12%, cardiac embolism in 18%, small vessel occlusion in 18%, other determined etiology in 23%, and undetermined in 29% (including 19% with incomplete evaluation). Vasculitis was deemed responsible for the stroke in 10 patients (13%) and hypercoagulability in 7 (9%). Protein S deficiency was noted in 10/22 (45%) and anticardiolipin antibodies in 9/31 (29%) tested patients. When comparing patients with large or small vessel disease (atherothrombotic strokes) vs the rest of the population, there were no differences in exposure to CART or CD4 count, but patients with non-atherothrombotic strokes were younger (p = 0.04). Recent cocaine exposure was less common among patients with atherothrombotic strokes (p = 0.02). Strokes were fatal or severely disabling in 35% of cases.

CONCLUSIONS

Stroke mechanisms are variable in HIV-infected patients, with a relatively high incidence of vasculitis and hypercoagulability. In our population of severely immunodepressed patients, exposure to combination antiretroviral treatment did not significantly influence the mechanism of stroke.

[Breeding places and biting activity of Anopheles species in the municipality of Cimitarra, Santander, Colombia]

INTRODUCTION

Forty five percent of malaria cases in the department of Santander, Colombia originate in the municipality of Cimitarra. This locality has reported cases from the rural and urban areas. The population between 15 and 45 years of age is the most affected. Additionally, Cimitarra has registered malaria cases in children under 1 year of age.

OBJECTIVE

To determine the biology and behavioral aspects of Anopheles mosquitoes from Cimitarra to more effectively orient control strategies.

MATERIALS AND METHODS

During October to December/2002 and March/2003, anopheline collections were undertaken. Isofamilies were obtained from 620 wild females.

RESULTS

The following species were found in order of abundance: Anopheles (Nyssorhynchus) triannulatus (Neiva y Pinto 1922), Anopheles (Nyssorhynchus) nuneztovari Gabaldón 1940, Anopheles (Nyssorhynchus) rangeli Gabaldón, Cova-García y López 1940, Anopheles (Anopheles) pseudopunctipennis Theobald 1901, Anopheles (Anopheles) mattogrosensis Lutz y Neiva 1911 and Anopheles (Anopheles) neomaculipalpus Curry 1933. The highest biting rate (0.5) was recorded for An. nuneztovari and An. triannulatus indoors between 20-21 hours. Forty two breeding places were sampled, 81% were fish ponds, 9.5% puddles and 2.3% cement tanks. Eighty seven percent of fish ponds were located near dwellings, being positive for anopheline larvae.

CONCLUSION

This study has shown that in Cimitarra cryptic and sister species of Anopheles genus occur in sympatry, Nyssorhynchus subgenera.