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1.
Immunity ; 50(3): 707-722.e6, 2019 03 19.
Article in English | MEDLINE | ID: mdl-30824323

ABSTRACT

Type 2 lymphocytes promote both physiologic tissue remodeling and allergic pathology, yet their physical tissue niches are poorly described. Here, we used quantitative imaging to define the tissue niches of group 2 innate lymphoid cells (ILC2s), which are critical instigators of type 2 immunity. We identified a dominant adventitial niche around lung bronchi and larger vessels in multiple tissues, where ILC2s localized with subsets of dendritic and regulatory T cells. However, ILC2s were most intimately associated with adventitial stromal cells (ASCs), a mesenchymal fibroblast-like subset that expresses interleukin-33 (IL-33) and thymic stromal lymphopoietin (TSLP). In vitro, ASCs produced TSLP that supported ILC2 accumulation and activation. ILC2s and IL-13 drove reciprocal ASC expansion and IL-33 expression. During helminth infection, ASC depletion impaired lung ILC2 and Th2 cell accumulation and function, which are in part dependent on ASC-derived IL-33. These data indicate that adventitial niches are conserved sites where ASCs regulate type 2 lymphocyte expansion and function.


Subject(s)
Immunity, Innate/immunology , Lymphocytes/immunology , Stromal Cells/immunology , Animals , Bronchi/immunology , Cytokines/immunology , Interleukin-13/immunology , Interleukin-33/immunology , Mice , T-Lymphocytes, Regulatory/immunology , Th2 Cells/immunology , Thymic Stromal Lymphopoietin
2.
J Neurosci ; 43(14): 2579-2596, 2023 04 05.
Article in English | MEDLINE | ID: mdl-36859308

ABSTRACT

Many social animals can recognize other individuals by their vocalizations. This requires a memory system capable of mapping incoming acoustic signals to one of many known individuals. Using the zebra finch, a social songbird that uses songs and distance calls to communicate individual identity (Elie and Theunissen, 2018), we tested the role of two cortical-like brain regions in a vocal recognition task. We found that the rostral region of the Cadomedial Nidopallium (NCM), a secondary auditory region of the avian pallium, was necessary for maintaining auditory memories for conspecific vocalizations in both male and female birds, whereas HVC (used as a proper name), a premotor areas that gates auditory input into the vocal motor and song learning pathways in male birds (Roberts and Mooney, 2013), was not. Both NCM and HVC have previously been implicated for processing the tutor song in the context of song learning (Sakata and Yazaki-Sugiyama, 2020). Our results suggest that NCM might not only store songs as templates for future vocal imitation but also songs and calls for perceptual discrimination of vocalizers in both male and female birds. NCM could therefore operate as a site for auditory memories for vocalizations used in various facets of communication. We also observed that new auditory memories could be acquired without intact HVC or NCM but that for these new memories NCM lesions caused deficits in either memory capacity or auditory discrimination. These results suggest that the high-capacity memory functions of the avian pallial auditory system depend on NCM.SIGNIFICANCE STATEMENT Many aspects of vocal communication require the formation of auditory memories. Voice recognition, for example, requires a memory for vocalizers to identify acoustical features. In both birds and primates, the locus and neural correlates of these high-level memories remain poorly described. Previous work suggests that this memory formation is mediated by high-level sensory areas, not traditional memory areas such as the hippocampus. Using lesion experiments, we show that one secondary auditory brain region in songbirds that had previously been implicated in storing song memories for vocal imitation is also implicated in storing vocal memories for individual recognition. The role of the neural circuits in this region in interpreting the meaning of communication calls should be investigated in the future.


Subject(s)
Finches , Vocalization, Animal , Animals , Male , Female , Acoustic Stimulation , Learning , Brain , Auditory Perception
3.
Hum Brain Mapp ; 45(10): e26768, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-38949537

ABSTRACT

Structural neuroimaging data have been used to compute an estimate of the biological age of the brain (brain-age) which has been associated with other biologically and behaviorally meaningful measures of brain development and aging. The ongoing research interest in brain-age has highlighted the need for robust and publicly available brain-age models pre-trained on data from large samples of healthy individuals. To address this need we have previously released a developmental brain-age model. Here we expand this work to develop, empirically validate, and disseminate a pre-trained brain-age model to cover most of the human lifespan. To achieve this, we selected the best-performing model after systematically examining the impact of seven site harmonization strategies, age range, and sample size on brain-age prediction in a discovery sample of brain morphometric measures from 35,683 healthy individuals (age range: 5-90 years; 53.59% female). The pre-trained models were tested for cross-dataset generalizability in an independent sample comprising 2101 healthy individuals (age range: 8-80 years; 55.35% female) and for longitudinal consistency in a further sample comprising 377 healthy individuals (age range: 9-25 years; 49.87% female). This empirical examination yielded the following findings: (1) the accuracy of age prediction from morphometry data was higher when no site harmonization was applied; (2) dividing the discovery sample into two age-bins (5-40 and 40-90 years) provided a better balance between model accuracy and explained age variance than other alternatives; (3) model accuracy for brain-age prediction plateaued at a sample size exceeding 1600 participants. These findings have been incorporated into CentileBrain (https://centilebrain.org/#/brainAGE2), an open-science, web-based platform for individualized neuroimaging metrics.


Subject(s)
Aging , Brain , Magnetic Resonance Imaging , Humans , Adolescent , Female , Aged , Adult , Child , Young Adult , Male , Brain/diagnostic imaging , Brain/anatomy & histology , Brain/growth & development , Aged, 80 and over , Child, Preschool , Middle Aged , Aging/physiology , Magnetic Resonance Imaging/methods , Neuroimaging/methods , Neuroimaging/standards , Sample Size
4.
Proc Natl Acad Sci U S A ; 118(37)2021 09 14.
Article in English | MEDLINE | ID: mdl-34493660

ABSTRACT

Skeletal muscle possesses remarkable regenerative ability because of the resident muscle stem cells (MuSCs). A prominent feature of quiescent MuSCs is a high content of heterochromatin. However, little is known about the mechanisms by which heterochromatin is maintained in MuSCs. By comparing gene-expression profiles from quiescent and activated MuSCs, we found that the mammalian Hairless (Hr) gene is expressed in quiescent MuSCs and rapidly down-regulated upon MuSC activation. Using a mouse model in which Hr can be specifically ablated in MuSCs, we demonstrate that Hr expression is critical for MuSC function and muscle regeneration. In MuSCs, loss of Hr results in reduced trimethylated Histone 3 Lysine 9 (H3K9me3) levels, reduced heterochromatin, increased susceptibility to genotoxic stress, and the accumulation of DNA damage. Deletion of Hr leads to an acceleration of the age-related decline in MuSC numbers. We have also demonstrated that despite the fact that Hr is homologous to a family of histone demethylases and binds to di- and trimethylated H3K9, the expression of Hr does not lead to H3K9 demethylation. In contrast, we show that the expression of Hr leads to the inhibition of the H3K9 demethylase Jmjd1a and an increase in H3K9 methylation. Taking these data together, our study has established that Hr is a H3K9 demethylase antagonist specifically expressed in quiescent MuSCs.


Subject(s)
Gene Silencing , Heterochromatin , Histone Demethylases/antagonists & inhibitors , Muscle, Skeletal/physiology , Stem Cells/physiology , Transcription Factors/metabolism , Animals , Histones/genetics , Histones/metabolism , Methylation , Mice , Mice, Hairless , Muscle, Skeletal/cytology , Stem Cells/cytology , Transcription Factors/genetics
5.
Pediatr Dermatol ; 40(3): 483-488, 2023.
Article in English | MEDLINE | ID: mdl-36851854

ABSTRACT

Atopic dermatitis (AD) is a common and chronic inflammatory skin disease that can adversely affect quality of life and carry significant burdens on physical, emotional, and social health. Recent evidence suggests that AD may also impair cognition, including attention and memory. In a pilot study of six children with AD, we administered a comprehensive battery of assessments to evaluate cognition and behavior and found that this approach was feasible and practical, which will enable the conduct of future larger-scale studies to characterize the impact of AD on cognitive function.


Subject(s)
Dermatitis, Atopic , Humans , Child , Dermatitis, Atopic/complications , Dermatitis, Atopic/psychology , Quality of Life , Pilot Projects , Physical Examination , Cognition
7.
Development ; 144(13): 2517-2528, 2017 07 01.
Article in English | MEDLINE | ID: mdl-28576768

ABSTRACT

The tear-producing lacrimal gland is a tubular organ that protects and lubricates the ocular surface. The lacrimal gland possesses many features that make it an excellent model in which to investigate tubulogenesis, but the cell types and lineage relationships that drive lacrimal gland formation are unclear. Using single-cell sequencing and other molecular tools, we reveal novel cell identities and epithelial lineage dynamics that underlie lacrimal gland development. We show that the lacrimal gland from its earliest developmental stages is composed of multiple subpopulations of immune, epithelial and mesenchymal cell lineages. The epithelial lineage exhibits the most substantial cellular changes, transitioning through a series of unique transcriptional states to become terminally differentiated acinar, ductal and myoepithelial cells. Furthermore, lineage tracing in postnatal and adult glands provides the first direct evidence of unipotent KRT5+ epithelial cells in the lacrimal gland. Finally, we show conservation of developmental markers between the developing mouse and human lacrimal gland, supporting the use of mice to understand human development. Together, our data reveal crucial features of lacrimal gland development that have broad implications for understanding epithelial organogenesis.


Subject(s)
Cell Lineage , Epithelial Cells/cytology , Lacrimal Apparatus/cytology , Lacrimal Apparatus/embryology , Acinar Cells/cytology , Acinar Cells/metabolism , Animals , Biomarkers/metabolism , Epithelial Cells/metabolism , Female , Gene Expression Profiling , Gene Expression Regulation, Developmental , Humans , Mice , Phenotype , Sequence Analysis, RNA , Single-Cell Analysis , Stem Cells/cytology , Stem Cells/metabolism
8.
Brain Behav Immun ; 87: 465-472, 2020 07.
Article in English | MEDLINE | ID: mdl-32001343

ABSTRACT

We hypothesized that elevations of microparticles (MPs) would occur with morphine administration to mice. Repetitive dosing to induce anti-nociceptive tolerance increases blood-borne MPs by 8-fold, and by 10-fold in deep cervical lymph nodes draining brain glymphatics. MPs express proteins specific to cells including neutrophils, microglia, astrocytes, neurons and oligodendrocytes. Interleukin (IL)-1ß content of MPs increases 68-fold. IL-1ß antagonist administration diminishes blood-borne and cervical lymph node MPs, and abrogates tolerance induction. Intravenous polyethylene glycol Telomer B, a surfactant that lyses MPs, and intraperitoneal methylnaltrexone also inhibit MPs elevations and tolerance. Critically, neutropenic mice do not develop anti-nociceptive tolerance, elevations of blood-borne or cervical node MPs. Immunohistochemical evidence for microglial activation by morphine does not correlated with the MPs response pattern. Neutrophil-derived MPs appear to be required for morphine-induced anti-nociceptive tolerance. Further, patients entering treatment for opioid use disorder exhibit similar MPs elevations as do tolerant mice.


Subject(s)
Cell-Derived Microparticles , Morphine , Analgesics, Opioid/pharmacology , Animals , Brain , Drug Tolerance , Humans , Immune Tolerance , Mice
9.
Appl Environ Microbiol ; 85(19)2019 10 01.
Article in English | MEDLINE | ID: mdl-31350318

ABSTRACT

Differentiating between contamination and the genuine presence of 16S rRNA genes in gestational tissue samples is the gold standard for supporting the in utero colonization hypothesis. During gestation, the fetus undergoes significant physiological changes that may be directly affected by maternal colonization of key bacterial genera. In this study, lab benches, necropsy tables, and air ducts were swabbed at the same time as clinical sampling. The relative and absolute abundance of bacteria present in sheep samples was determined by culture-independent and culture-dependent means. Of 14 healthy pregnant ewes, there was no evidence of any bacteria in the fetal liver, spleen, or brain cortex using culture-independent techniques despite evidence of the presence of bacteria in various locations of the necropsy room used for 11 of these 14 sheep. Of the 336 bacterial genera found in the room swabs, only 12 (5%) were also found in the saliva and vaginal swabs among the three ewes for which bacteria were detected. These 12 taxa represent 1.32% of the relative abundance and approximately 393 16S rRNA copies/swab in these three ewes. Using careful necropsy protocols, bacterial contamination of sheep tissues was avoided. Contamination of saliva and vaginal samples was limited to less than 2% of the bacterial population.IMPORTANCE Recent evidence for a gestational microbiome suggests that active transfer between mother and fetus in utero is possible, and, therefore, actions must be taken to clarify the presence versus absence of these organisms in their respected sources. The value of this study is the differentiation between bacterial DNA identified in the necropsy rooms of animals and bacterial DNA whose origin is purely clinical in nature. We do not know the extent to which microorganisms traverse maternal tissues and infiltrate fetal circulation, so measures taken to control for contamination during sample processing are vital for addressing these concerns.


Subject(s)
Autopsy/instrumentation , Bacteria/isolation & purification , Equipment Contamination , Microbiota , Animals , Bacteria/classification , Colony Count, Microbial , DNA, Bacterial/genetics , Female , Fetus/microbiology , Pregnancy , Pregnancy, Animal , RNA, Ribosomal, 16S/genetics , Saliva/microbiology , Sheep , Vagina/microbiology
10.
BMC Neurol ; 19(1): 140, 2019 Jun 24.
Article in English | MEDLINE | ID: mdl-31234791

ABSTRACT

BACKGROUND: Body weight supported treadmill training (BWSTT) is a frequently used approach for restoring the ability to walk after spinal cord injury (SCI). However, the duration of BWSTT is usually limited by fatigue of the therapists and patients. Robotic-assisted body weight supported treadmill training (RABWSTT) was developed to tackle the aforesaid limitation. Currently, limited randomized controlled trials are available to investigate its effectiveness, especially on cardiopulmonary function. The aim of this two-arm, parallel-group randomized controlled trial is to examine the feasibility of adapting an EMG-biofeedback system for assist-as-needed RABWSTT and its effects on walking and cardiopulmonary function in people with SCI. METHODS: Sixteen incomplete SCI subjects were recruited and randomly allocated into an intervention group or control group. The intervention group received 30 min of RABWSTT with EMG biofeedback system over the vastus lateralis muscle to enhance active participation. Dose equivalent passive lower limbs mobilization exercise was provided to subjects in the control group. RESULTS: Significant time-group interaction was found in the Walking Index for Spinal Cord Injury version II (WISCI II) (p = 0.020), Spinal Cord Independence Measure version III (SCIM III) mobility sub-score (p < 0.001), bilateral symmetry (p = 0.048), maximal oxygen consumption (p = 0.014) and peak expiratory flow rate (p = 0.048). Wilcoxon signed-rank test showed that the intervention group had significant improvement in the above-mentioned outcomes after the intervention except WISCI II, which also yielded marginal significance level. CONCLUSION: The present study demonstrated that the use of EMG-biofeedback RABWSTT enhanced the walking performance for SCI subjects and improve cardiopulmonary function. Positive outcomes reflect that RABSTT training may be able to enhance their physical fitness. TRIAL REGISTRATION: The study protocol was approved by the Research Ethics Committee (Kowloon Central/ Kowloon East), Hospital Authority on 6 December 2013, and the Human Subjects Ethics Sub-committee of The Hong Kong Polytechnic University on 15 May 2013, with reference numbers KC/KC-13-0181/ER-2 and HSEARS20130510002 respectively. The study was registered in ClinicalTrials.gov on 20 November 2013, with reference number NCT01989806 .).


Subject(s)
Biofeedback, Psychology , Cardiorespiratory Fitness , Electromyography/methods , Robotics/instrumentation , Spinal Cord Injuries/physiopathology , Spinal Cord Injuries/rehabilitation , Walking/physiology , Adolescent , Adult , Body Weight , Exercise Test/methods , Female , Humans , Male , Middle Aged , Oxygen Consumption , Physical Therapy Modalities/instrumentation
11.
Int J Hyperthermia ; 36(1): 986-992, 2019.
Article in English | MEDLINE | ID: mdl-31544546

ABSTRACT

Background: Treatment for locally recurrent breast cancer poses a significant challenge because the benefits in local control must be weighed against the increased risk of side effects of the treatment. Frequently, patients have been heavily pre-treated with radiation and several types of chemotherapy. Moreover, they often present with large volumes of bulky disease, further complicating management. Hyperthermia can be used to improve the efficacy of radiation, particularly in the setting of recurrent disease. Methods: We reviewed our clinical and dosimetric experience of breast cancer patients who received hyperthermia and radiation for recurrent breast cancer from 2011 to 2017. Thirty-six patients were treated with hyperthermia and radiation. Median follow-up was 11 months. Thirty patients (83.3%) received prior radiotherapy. The most commonly used radiation fraction scheme was 32 Gy in 8 fractions. The median radiation dose at the time of recurrence was 35.5 Gy (range 20-64 Gy). Mild temperature hyperthermia was delivered two times per week. Results: The median repeat radiation volume was 574 cc (range 11-3620 cc). Electrons, conventional photons, and IMRT radiation techniques were used. IMRT was used for large and complex treatment volumes and showed acceptable doses to organs at risk. The overall response rate was 61.1%. Complete response was observed in 17 patients (47.2%), partial response in 5 patients (13.9%), stable disease in 11 patients (30.6%), and progressive disease in 3 patients (8.3%). Twenty-six patients experienced acute grade 1 and 2 toxicities, primarily pain and erythema; and 26 experienced long-term grade 1 and 2 toxicities, mainly hyperpigmentation and lymphedema. Three patients developed new ulcerations that healed with conservative management. One patient developed pulmonary fibrosis resulting in mild dyspnea on exertion. Conclusion: Hyperthermia and radiation provide good local control with a favorable side effect profile. Thermoradiotherapy may be offered to patients with recurrent breast cancer, including those with extensive volumes of disease.


Subject(s)
Breast Neoplasms/radiotherapy , Hyperthermia, Induced/methods , Radiometry/methods , Breast Neoplasms/pathology , Female , Humans , Neoplasm Recurrence, Local , Radiotherapy Dosage
12.
Nucleic Acids Res ; 45(17): 10178-10189, 2017 Sep 29.
Article in English | MEDLINE | ID: mdl-28973453

ABSTRACT

Clamp loaders load ring-shaped sliding clamps onto DNA where the clamps serve as processivity factors for DNA polymerases. In the first stage of clamp loading, clamp loaders bind and stabilize clamps in an open conformation, and in the second stage, clamp loaders place the open clamps around DNA so that the clamps encircle DNA. Here, the mechanism of the initial clamp opening stage is investigated. Mutations were introduced into the Escherichia coli ß-sliding clamp that destabilize the dimer interface to determine whether the formation of an open clamp loader-clamp complex is dependent on spontaneous clamp opening events. In other work, we showed that mutation of a positively charged Arg residue at the ß-dimer interface and high NaCl concentrations destabilize the clamp, but neither facilitates the formation of an open clamp loader-clamp complex in experiments presented here. Clamp opening reactions could be fit to a minimal three-step 'bind-open-lock' model in which the clamp loader binds a closed clamp, the clamp opens, and subsequent conformational rearrangements 'lock' the clamp loader-clamp complex in a stable open conformation. Our results support a model in which the E. coli clamp loader actively opens the ß-sliding clamp.


Subject(s)
Bacterial Proteins/metabolism , DNA Polymerase III/metabolism , DNA Replication , DNA, Bacterial/metabolism , Escherichia coli Proteins/metabolism , Adenosine Triphosphate/metabolism , Amino Acid Substitution , Bacterial Proteins/chemistry , DNA Polymerase III/chemistry , DNA, Bacterial/genetics , Dimerization , Escherichia coli/genetics , Escherichia coli/metabolism , Escherichia coli Proteins/chemistry , Kinetics , Models, Chemical , Models, Molecular , Mutation, Missense , Protein Binding , Protein Conformation , Protein Stability , Protein Subunits , Sodium Chloride/pharmacology , Structure-Activity Relationship
13.
J Infect Dis ; 218(suppl_5): S612-S626, 2018 11 22.
Article in English | MEDLINE | ID: mdl-29860496

ABSTRACT

Background: For most classes of drugs, rapid development of therapeutics to treat emerging infections is challenged by the timelines needed to identify compounds with the desired efficacy, safety, and pharmacokinetic profiles. Fully human monoclonal antibodies (mAbs) provide an attractive method to overcome many of these hurdles to rapidly produce therapeutics for emerging diseases. Methods: In this study, we deployed a platform to generate, test, and develop fully human antibodies to Zaire ebolavirus. We obtained specific anti-Ebola virus (EBOV) antibodies by immunizing VelocImmune mice that use human immunoglobulin variable regions in their humoral responses. Results: Of the antibody clones isolated, 3 were selected as best at neutralizing EBOV and triggering FcγRIIIa. Binding studies and negative-stain electron microscopy revealed that the 3 selected antibodies bind to non-overlapping epitopes, including a potentially new protective epitope not targeted by other antibody-based treatments. When combined, a single dose of a cocktail of the 3 antibodies protected nonhuman primates (NHPs) from EBOV disease even after disease symptoms were apparent. Conclusions: This antibody cocktail provides complementary mechanisms of actions, incorporates novel specificities, and demonstrates high-level postexposure protection from lethal EBOV disease in NHPs. It is now undergoing testing in normal healthy volunteers in preparation for potential use in future Ebola epidemics.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/therapeutic use , Hemorrhagic Fever, Ebola/drug therapy , Animals , Antibodies, Monoclonal/isolation & purification , Glycoproteins/immunology , Guinea Pigs , HEK293 Cells , Humans , Macaca mulatta , Male , Mice
14.
J Biol Chem ; 292(44): 18312-18324, 2017 11 03.
Article in English | MEDLINE | ID: mdl-28972154

ABSTRACT

Microparticles are lipid bilayer-enclosed vesicles produced by cells under oxidative stress. MP production is elevated in patients with diabetes, but the underlying cellular mechanisms are poorly understood. We hypothesized that raising glucose above the physiological level of 5.5 mm would stimulate leukocytes to produce MPs and activate the nucleotide-binding domain, leucine-rich repeat pyrin domain-containing 3 (NLRP3) inflammasome. We found that when incubated in buffer with up to 20 mm glucose, human and murine neutrophils, but not monocytes, generate progressively more MPs with high interleukin (IL)-1ß content. Enhanced MP production required generation of reactive chemical species by mitochondria, NADPH oxidase, and type 2 nitric-oxide synthase (NOS-2) and resulted in S-nitrosylation of actin. Depleting cells of capon (C-terminal PDZ ligand of neuronal nitric-oxide synthase protein), apoptosis-associated speck-like protein containing C-terminal caspase recruitment domain (ASC), or pro-IL-1ß prevented the hyperglycemia-induced enhancement of reactive species production, MP generation, and IL-1ß synthesis. Additional components required for these responses included inositol 1,3,5-triphosphate receptors, PKC, and enhancement of filamentous-actin turnover. Numerous proteins become localized to short filamentous actin in response to S-nitrosylation, including vasodilator-stimulated phosphoprotein, focal adhesion kinase, the membrane phospholipid translocation enzymes flippase and floppase, capon, NLRP3, and ASC. We conclude that an interdependent oxidative stress response to hyperglycemia perturbs neutrophil cytoskeletal stability leading to MP production and IL-1ß synthesis.


Subject(s)
Cell-Derived Microparticles/metabolism , Cytoskeleton/metabolism , Hyperglycemia/metabolism , Inflammasomes/metabolism , Neutrophil Activation , Neutrophils/metabolism , Oxidative Stress , Actins/metabolism , Adaptor Proteins, Signal Transducing/antagonists & inhibitors , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Animals , Cell-Derived Microparticles/immunology , Cell-Derived Microparticles/pathology , Cytoskeleton/immunology , Cytoskeleton/pathology , Humans , Hyperglycemia/immunology , Hyperglycemia/pathology , Inflammasomes/immunology , Interleukin-1beta/antagonists & inhibitors , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Mice, Inbred C57BL , Mice, Knockout , Monocytes/immunology , Monocytes/metabolism , Monocytes/pathology , NADPH Oxidases/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Neutrophils/immunology , Neutrophils/pathology , Nitric Oxide Synthase Type II/genetics , Nitric Oxide Synthase Type II/metabolism , Protein Processing, Post-Translational , Protein Stability , RNA Interference
17.
Soft Matter ; 13(13): 2437-2447, 2017 Mar 29.
Article in English | MEDLINE | ID: mdl-28239709

ABSTRACT

The present study demonstrates the ability of excess, weakly amphiphilic n-alkanethiols (n = 4, 12, 18) and solvent composition to tune through a wide range of large-scale, macroscopic architectures formed by alkanethiol-capped Au nanoparticles (NPs). Both the alkanethiols and NPs are significantly hydrophobic species and compete for surface area at an air-water interface. When solutions of the two species are spread on a large (50 cm2) water surface in a Teflon well, a thin film forms and exhibits co-existing macroscopic regions with various distinct NP self-assembled architectures, namely a close packed monolayer, a network phase characterized by micron-sized pores (micropores) surrounded by quasi-linear bundles of nanoparticles, and finally aggregates. We hypothesize that the co-existence of various NP architectures results from fast, non-uniform evaporation across the large water surface. When solutions are instead deposited on a smaller (5 cm2) water surface contained within a Teflon ring to control the water surface curvature and the evaporation rate is slowed, we show for the first time that NPs form macroscopically uniform self-assemblies whose architectures can be tuned from monolayers → monolayers with micropores → extended micropore/NP bundle networks by varying excess alkanethiol concentration and solvent composition. We propose that competition between NPs and excess alkanethiols for water surface area, and alkanethiol self-assembly as well as solvent dewetting play important roles in the formation of the network phase, and discuss a potential mechanism for its formation.

18.
Arch Phys Med Rehabil ; 98(11): 2320-2331.e12, 2017 11.
Article in English | MEDLINE | ID: mdl-28645768

ABSTRACT

OBJECTIVE: To investigate the effects of robot-assisted training on the recovery of people with spinal cord injury (SCI). DATA SOURCES: Randomized controlled trials (RCTs) or quasi-RCTs involving people with SCI that compared robot-assisted upper limbs or lower limbs training with a control of other treatment approach or no treatment. We included studies involving people with complete or incomplete SCIs. STUDY SELECTION: We searched MEDLINE, CINAHL, Cochrane Central Register of Controlled Trials (Cochrane Library), and Embase to August 2016. Bibliographies of relevant articles on the effect of body-weight-supported treadmill training on subjects with SCI were screened to avoid missing relevant articles from the search of databases. DATA EXTRACTION: All kinds of objective assessments concerning physical ability, mobility, and/or functional ability were included. Assessments could be clinical tests (ie, 6-minute walk test, FIM) or laboratory tests (ie, gait analysis). Subjective outcome measures were excluded from this review. DATA SYNTHESIS: Eleven RCT studies involving 443 subjects were included in the study. Meta-analysis was performed on the included studies. Walking independence (3.73; 95% confidence interval [CI], -4.92 to -2.53; P<.00001; I2=38%) and endurance (53.32m; 95% CI, -73.15 to -33.48; P<.00001; I2=0%) were found to have better improvement in robot-assisted training groups. Lower limb robot-assisted training was also found to be as effective as other types of body-weight-supported training. There is a lack of upper limb robot-assisted training studies; therefore, performing a meta-analysis was not possible. CONCLUSIONS: Robot-assisted training is an adjunct therapy for physical and functional recovery for patients with SCI. Future high-quality studies are warranted to investigate the effects of robot-assisted training on functional and cardiopulmonary recovery of patients with SCI.


Subject(s)
Physical Therapy Modalities , Robotics , Spinal Cord Injuries/rehabilitation , Activities of Daily Living , Humans , Lower Extremity/physiopathology , Randomized Controlled Trials as Topic , Recovery of Function , Upper Extremity/physiopathology
19.
J Biol Chem ; 290(28): 17474-84, 2015 Jul 10.
Article in English | MEDLINE | ID: mdl-26032418

ABSTRACT

This investigation explored the mechanism for inhibition of ß2 integrin adhesion molecules when neutrophils are exposed to nitric oxide ((•)NO). Roles for specific proteins were elucidated using chemical inhibitors, depletion with small inhibitory RNA, and cells from knock-out mice. Optimal inhibition occurs with exposures to a (•)NO flux of ∼ 28 nmol/min for 2 min or more, which sets up an autocatalytic cascade triggered by activating type 2 nitric-oxide synthase (NOS-2) and NADPH oxidase (NOX). Integrin inhibition does not occur with neutrophils exposed to a NOX inhibitor (Nox2ds), a NOS-2 inhibitor (1400 W), or with cells from mice lacking NOS-2 or the gp91(phox) component of NOX. Reactive species cause S-nitrosylation of cytosolic actin that enhances actin polymerization. Protein cross-linking and actin filament formation assays indicate that increased polymerization occurs because of associations involving vasodilator-stimulated phosphoprotein, focal adhesion kinase, and protein-disulfide isomerase in proximity to actin filaments. These effects were inhibited in cells exposed to ultraviolet light which photo-reverses S-nitrosylated cysteine residues and by co-incubations with cytochalasin D. The autocatalytic cycle can be arrested by protein kinase G activated with 8-bromo-cyclic GMP and by a high (•)NO flux (∼ 112 nmol/min) that inactivates NOX.


Subject(s)
CD18 Antigens/metabolism , Neutrophils/metabolism , Nitric Oxide/metabolism , Actins/metabolism , Animals , Cell Adhesion , Cyclic GMP/analogs & derivatives , Cyclic GMP/pharmacology , Guanylate Cyclase/antagonists & inhibitors , Guanylate Cyclase/genetics , Guanylate Cyclase/metabolism , Humans , Hydrazines/pharmacology , Membrane Glycoproteins/deficiency , Membrane Glycoproteins/genetics , Membrane Glycoproteins/metabolism , Mice , Mice, Knockout , NADPH Oxidase 2 , NADPH Oxidases/deficiency , NADPH Oxidases/genetics , NADPH Oxidases/metabolism , Neutrophils/drug effects , Nitric Oxide Synthase Type II/deficiency , Nitric Oxide Synthase Type II/genetics , Nitric Oxide Synthase Type II/metabolism , RNA, Small Interfering/genetics
20.
Ecotoxicol Environ Saf ; 134P1: 213-225, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27639196

ABSTRACT

The potential adverse health effects of mercury from amalgam and bisphenol A (BPA) from composite resin have been significant concerns. It is unclear whether dental restorative materials significantly contribute to mercury or BPA levels. The purpose of this study is to use NHANES data including 14,703 subjects (2003-2004: n=7514; 2011-2012: n=7189) to examine the association between Dental Surface Restorations (DSR) and blood total mercury (THg), inorganic mercury (IHg), methyl mercury (MeHg) and urinary BPA through the stratification of covariates and multivariate analysis. Subjects were divided into three groups based on the number of dental surface restorations (DSRs, 0, 1-8, >8). Blood THg and IHg in 2003-2004 were significantly higher in the subjects with DSR (geometric mean of 0.48, 0.69 and 1.17µg/l for THg; 0.32, 0.33 and 0.39µg/l for IHg with DSR 0, 1-8 and >8). Similarly, increases of THg, IHg and MeHg were also observed in 2013-2014 (geometric mean of 0.51, 0.69 and 0.99µg/l for THg; 0.40, 0.49 and 0.66µg/l for MeHg; 0.20, 0.22 and 0.29µg/l for IHg with DSR 0, 1-8 and >8). Linear regression model analysis revealed blood THg and IHg in 2003-2004 and THg, IHg and MeHg in 2011-2012 were quantitatively associated with the number of DSRs. A dramatic decrease in urinary BPA from 2003 to 2004-2011-2012 was observed, but no significant increase with DSRs in either period of study. In conclusion, significant increases in blood THg, IHg, and MeHg in the subjects with DSRs are confirmed in a nationally representative population, a critical step in assessing the potential risk of adverse effects from dental restorative materials, but no association between dental fillings and urinary BPA was found.

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