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3.
J Infect Dis ; 227(8): 1002-1006, 2023 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-36200239

RESUMO

Serological testing of Singaporeans who received childhood smallpox vaccination found anti-vaccinia IgG binding and neutralizing activity indicating long-term humoral immunity. There was correlation between IgG and neutralizing titers indicating IgG could be used as a surrogate marker for humoral immunity. In 2019, Singapore experienced a case of imported monkeypox. As with smallpox, disease can be prevented through vaccination, which was mandatory for Singaporean infants until 1981. However, the degree of residual immunity in older vaccinated Singaporeans remains unknown. Sera from individuals born 1946-1984 were therefore tested and those born prior to 1981 were found to have higher anti-vaccinia IgG and neutralizing activity titers. This suggests that protective humoral immunity remains, which could reduce disease severity in an orthopoxvirus outbreak. Correlation between IgG and neutralizing titers was observed indicating that serology could be used as a surrogate marker for immunity.


Assuntos
Vacina Antivariólica , Varíola , Vacínia , Vírus da Varíola , Lactente , Humanos , Criança , Idoso , Imunidade Humoral , Varíola/prevenção & controle , Vaccinia virus , Vacinação , Imunoglobulina G , Anticorpos Antivirais
4.
Biol Psychiatry Glob Open Sci ; 2(2): 147-152, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36325161

RESUMO

Background: Structural magnetic resonance imaging studies in individuals at clinical high risk (CHR) for psychosis have yielded conflicting results. Methods: The aims of this study were to compare intracranial and structural brain volumes and variability of CHR individuals with those of healthy control (HC) subjects and to investigate brain volume differences and variability in CHR subjects with and without transition to psychosis. The PubMed and Embase databases were searched for relevant studies published before June 1, 2020. Results: A total of 34 studies were deemed eligible, which included baseline data of 2111 CHR and 1472 HC participants. In addition, data were included for 401 CHR subjects who subsequently transitioned to psychosis and 1023 nontransitioned CHR participants. Whole-brain and left, right, and bilateral hippocampal volume were significantly smaller in CHR subjects than in HC subjects. Cerebrospinal fluid and lateral ventricle volumes were significantly larger in CHR subjects than in HC subjects. Variability was not significantly different in CHR subjects compared with HC subjects. CHR individuals with and without subsequent transition to psychosis did not show significant differences in any of the volumetric assessments or in variability. Conclusions: This meta-analysis demonstrates reduced whole-brain and hippocampal volumes and increased cerebrospinal fluid and lateral ventricle volumes in CHR individuals. However, no significant differences were observed in any of the volumetric assessments between CHR individuals with and without subsequent transition to psychosis. These findings suggest that although structural brain alterations are present before the onset of the disorder, they may not significantly contribute to the identification of CHR individuals at the highest risk for the development of psychosis.

5.
Infect Dis Ther ; 11(5): 1999-2015, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36058990

RESUMO

INTRODUCTION: AOD01 is a novel, fully human immunoglobulin (Ig) G1 neutralizing monoclonal antibody that was developed as a therapeutic against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). This first-in-human study assessed safety, tolerability, pharmacokinetics (PK), and pharmacodynamics of AOD01 in healthy volunteers. METHODS: Intravenous doses of AOD01 were evaluated in escalating cohorts [four single-dose cohorts (2, 5, 10, and 20 mg/kg) and one two-dose cohort (two doses of 20 mg/kg, 24 h apart)]. RESULTS: Twenty-three subjects were randomized to receive AOD01 or a placebo in blinded fashion. A total of 34 treatment-emergent adverse events (TEAEs) were reported; all were mild in severity. Related events (headache and diarrhea) were reported in one subject each. No event of infusion reactions, serious adverse event (SAE), or discontinuation due to AE were reported. The changes in laboratory parameters, vital signs, and electrocardiograms were minimal. Dose-related exposure was seen from doses 2 to 20 mg/kg as confirmed by Cmax and AUC0-tlast. The median Tmax was 1.5-3 h. Clearance was dose independent. Study results revealed long half-lives (163-465 h). Antidrug antibodies (ADA) to AOD01 were not detected among subjects, except in one subject of the two-dose cohort on day 92. Sustained ex vivo neutralization of SARS-CoV-2 was recorded until day 29 with single doses from 2 to 20 mg/kg and until day 43 with two doses of 20 mg/kg. CONCLUSIONS: AOD01 was safe and well tolerated, demonstrated dose-related PK, non-immunogenic status, and sustained ex vivo neutralization of SARS-CoV-2 after single intravenous dose ranging from 2 to 20 mg/kg and two doses of 20 mg/kg and show good potential for treatment of SARS-CoV-2 infection. (Health Sciences Authority identifier number CTA2000119).

6.
ACS Nano ; 16(9): 15141-15154, 2022 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-35977379

RESUMO

Nanomedicine-based and unmodified drug interventions to address COVID-19 have evolved over the course of the pandemic as more information is gleaned and virus variants continue to emerge. For example, some early therapies (e.g., antibodies) have experienced markedly decreased efficacy. Due to a growing concern of future drug resistant variants, current drug development strategies are seeking to find effective drug combinations. In this study, we used IDentif.AI, an artificial intelligence-derived platform, to investigate the drug-drug and drug-dose interaction space of six promising experimental or currently deployed therapies at various concentrations: EIDD-1931, YH-53, nirmatrelvir, AT-511, favipiravir, and auranofin. The drugs were tested in vitro against a live B.1.1.529 (Omicron) virus first in monotherapy and then in 50 strategic combinations designed to interrogate the interaction space of 729 possible combinations. Key findings and interactions were then further explored and validated in an additional experimental round using an expanded concentration range. Overall, we found that few of the tested drugs showed moderate efficacy as monotherapies in the actionable concentration range, but combinatorial drug testing revealed significant dose-dependent drug-drug interactions, specifically between EIDD-1931 and YH-53, as well as nirmatrelvir and YH-53. Checkerboard validation analysis confirmed these synergistic interactions and also identified an interaction between EIDD-1931 and favipiravir in an expanded range. Based on the platform nature of IDentif.AI, these findings may support further explorations of the dose-dependent drug interactions between different drug classes in further pre-clinical and clinical trials as possible combinatorial therapies consisting of unmodified and nanomedicine-enabled drugs, to combat current and future COVID-19 strains and other emerging pathogens.


Assuntos
Tratamento Farmacológico da COVID-19 , SARS-CoV-2 , Amidas , Inteligência Artificial , Auranofina , Guanosina Monofosfato/análogos & derivados , Humanos , Fosforamidas , Pirazinas
7.
Am J Health Syst Pharm ; 79(6): 460-466, 2022 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-34636394

RESUMO

PURPOSE: As the pharmacist's role expands, particularly in primary care practice settings, there is an opportunity for expansion of pharmacy technician duties to aid in administrative and clinical tasks that do not require the pharmacist's professional judgment. Identifying, defining, and expanding the roles of pharmacy technicians has been deemed a key part of the pharmacy practice model. These roles have been shown to enhance pharmacist efficiency and patient outreach; however, examples of the various innovative activities performed by technicians in the primary care setting are lacking in the literature. METHODS: The duties of primary care pharmacy technicians were compiled and defined in 2 different healthcare systems. The role of the technician was separately implemented at each institution, and study designs and protocols were individually created and executed. One institution utilized a 4-round consensus-building process to systematically refine and codify tasks for a dictionary of duties. The second institution utilized a free-text survey, task documentation data in the electronic medical record, and a telephone discussion with the technicians. RESULTS: Despite a lack of methods- and data-sharing between the 2 institutions, similar tasks were identified, including conducting patient outreach, assisting with medication affordability and access, providing patient education, managing referrals, and scheduling appointments. Differences in technician involvement were noted in areas such as prior authorization, care coordination meetings, and quality improvement projects. CONCLUSION: Pharmacy technicians are a helpful, yet underutilized, resource in the primary care setting. Further exploration of technician roles is needed to determine the financial and clinical impact of expanding these roles.


Assuntos
Farmácias , Farmácia , Humanos , Farmacêuticos , Técnicos em Farmácia , Atenção Primária à Saúde , Papel Profissional
8.
PLoS One ; 16(6): e0253487, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34161386

RESUMO

Although SARS-CoV-2-neutralizing antibodies are promising therapeutics against COVID-19, little is known about their mechanism(s) of action or effective dosing windows. We report the generation and development of SC31, a potent SARS-CoV-2 neutralizing antibody, isolated from a convalescent patient. Antibody-mediated neutralization occurs via an epitope within the receptor-binding domain of the SARS-CoV-2 Spike protein. SC31 exhibited potent anti-SARS-CoV-2 activities in multiple animal models. In SARS-CoV-2 infected K18-human ACE2 transgenic mice, treatment with SC31 greatly reduced viral loads and attenuated pro-inflammatory responses linked to the severity of COVID-19. Importantly, a comparison of the efficacies of SC31 and its Fc-null LALA variant revealed that the optimal therapeutic efficacy of SC31 requires Fc-mediated effector functions that promote IFNγ-driven anti-viral immune responses, in addition to its neutralization ability. A dose-dependent efficacy of SC31 was observed down to 5mg/kg when administered before viral-induced lung inflammatory responses. In addition, antibody-dependent enhancement was not observed even when infected mice were treated with SC31 at sub-therapeutic doses. In SARS-CoV-2-infected hamsters, SC31 treatment significantly prevented weight loss, reduced viral loads, and attenuated the histopathology of the lungs. In rhesus macaques, the therapeutic potential of SC31 was evidenced through the reduction of viral loads in both upper and lower respiratory tracts to undetectable levels. Together, the results of our preclinical studies demonstrated the therapeutic efficacy of SC31 in three different models and its potential as a COVID-19 therapeutic candidate.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/farmacologia , COVID-19/terapia , SARS-CoV-2/imunologia , Enzima de Conversão de Angiotensina 2/genética , Animais , Anticorpos Neutralizantes/metabolismo , COVID-19/imunologia , COVID-19/virologia , Quimiocinas/sangue , Quimiocinas/genética , Chlorocebus aethiops , Convalescença , Cricetinae , Citocinas/sangue , Citocinas/genética , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Humanos , Fragmentos Fc das Imunoglobulinas/imunologia , Imunoglobulina G/imunologia , Imunoglobulina G/isolamento & purificação , Macaca mulatta , Masculino , Camundongos Transgênicos , Glicoproteína da Espícula de Coronavírus/metabolismo , Células Vero , Carga Viral
9.
Bioeng Transl Med ; 6(1): e10196, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33532594

RESUMO

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to multiple drug repurposing clinical trials that have yielded largely uncertain outcomes. To overcome this challenge, we used IDentif.AI, a platform that pairs experimental validation with artificial intelligence (AI) and digital drug development to rapidly pinpoint unpredictable drug interactions and optimize infectious disease combination therapy design with clinically relevant dosages. IDentif.AI was paired with a 12-drug candidate therapy set representing over 530,000 drug combinations against the SARS-CoV-2 live virus collected from a patient sample. IDentif.AI pinpointed the optimal combination as remdesivir, ritonavir, and lopinavir, which was experimentally validated to mediate a 6.5-fold enhanced efficacy over remdesivir alone. Additionally, it showed hydroxychloroquine and azithromycin to be relatively ineffective. The study was completed within 2 weeks, with a three-order of magnitude reduction in the number of tests needed. IDentif.AI independently mirrored clinical trial outcomes to date without any data from these trials. The robustness of this digital drug development approach paired with in vitro experimentation and AI-driven optimization suggests that IDentif.AI may be clinically actionable toward current and future outbreaks.

10.
J Affect Disord Rep ; 4: 100102, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33558866

RESUMO

Background COVID-19 has seriously affected physical and mental health world-wide,both due to spreading of the virus and due to the socially restrictive measures most governments have enforced. Increased anxiety, stress and depressive symptoms have been widely reported in the general population. The current study investigated the effects of COVID and the restrictive measures in the Netherlands on stress, anxiety and loneliness in patients with a pre-existing psychiatric disorder. Methods 189 patients with a pre-existing psychiatric disorder treated at the University Medical Center Utrecht (UMCU) provided consent to participate in an electronically provided survey. Questionnaires on anxiety, depressive symptoms, worry, stress and general health were completed by 148 participants. Results All patients reported heightened distress as well as the presence of depressive symptoms and loneliness during the initial phase of the restrictive measures. Patients could be divided into two major subgroups with either psychotic disorder (n = 71) and affective disorder (n = 86). Patients with affective disorders were more affected by the outbreak and accompanying socially restrictive measures than patients with psychotic disorders. Conclusions Our findings indicate negative mental health effects of the global COVID-19 pandemic and the restrictive measures in a particularly vulnerable population, with differential effects on diagnostic groups.

11.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-355107

RESUMO

SARS-CoV-2-neutralizing antibodies are promising therapeutics for COVID-19. However, little is known about the mechanisms of action of these antibodies or their effective dosing windows. We report the discovery and development of SC31, a potent SARS-CoV-2 neutralizing IgG1 antibody, originally isolated from a convalescent patient at day 27 after the onset of symptoms. Neutralization occurs via a binding epitope that maps within the ACE2 interface of the SARS-CoV-2 Spike protein, conserved across all common circulating SARS-CoV-2 mutants. In SARS-CoV-2 infected K18-human ACE2 transgenic mice, SC31 demonstrated potent survival benefit by dramatically reducing viral load concomitant with attenuated pro-inflammatory responses linked to severe systemic disease, such as IL-6. Comparison with a Fc-null LALA variant of SC31 demonstrated that optimal therapeutic efficacy of SC31 requires intact Fc-mediated effector functions that can further induce an IFN{gamma}-driven anti-viral immune response. Dose-dependent efficacy for SC31 was observed down to 5mg/kg when dosed before the activation of lung inflammatory responses. Importantly, despite Fc{gamma}R binding, no evidence of antibody dependent enhancement was observed with the Fc-competent SC31 even at sub-therapeutic doses. Therapeutic efficacy was confirmed in SARS-CoV-2-infected hamsters, where SC31 again significantly reduced viral load, decreased lung lesions and inhibited progression to severe disease manifestations. This study underlines the potential for significant COVID-19 patient benefit for the SC31 antibody that justifies rapid advancement to the clinic, as well as highlighting the importance of appropriate mechanistic and functional studies during development. One Sentence SummaryAnti-SARS-CoV-2 IgG1 antibody SC31 controls infection in vivo by blocking SP:ACE2 binding and triggering a Fc-mediated anti-viral response.

12.
J Phys Chem Lett ; 11(21): 8937-8943, 2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-32902297

RESUMO

Paradoxically, a very broad diffraction background, named the bell-shaped-component (BSC), has been established as a feature of graphene growth. Recent diffraction studies as a function of electron energy have shown that the BSC is not related to scattering interference. Here, additional experiments are carried out as a function of temperature over the range in which single-layer graphene (SLG) grows. Quantitative fitting of the profiles shows that the BSC follows the increase of the Gr(10) spot, proving directly that the BSC indicates high-quality graphene. Additional metal deposition experiments provide more information about the BSC. The BSC is insensitive to metal deposition, and it increases with metal intercalation, because a more uniform interface forms between graphene and SiC. These experiments support the conclusion that the BSC originates from electron confinement within SLG, and surprisingly, it is an excellent measure of graphene uniformity.

13.
J Med Chem ; 63(21): 12156-12170, 2020 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-32633947

RESUMO

Lipophilicity has a dominant effect on many parameters that determine unbound drug exposure as well as drug potency. Despite this, analysis of a large body of drug data indicates lipophilicity has no consistent directional impact on dose. This can be rationalized based on the interplay of the effects of lipophilicity on individual parameter values in pharmacokinetic equations. We believe this undermines the effectiveness of strategies that target specific ranges for drug parameters for which lipophilicity plays such a dominant role. As a result, our research organization no longer leverages the common approach of screening for low intrinsic clearance in vitro to target high unbound exposure in vivo. Instead, we advocate for approaches less biased to lipophilicity through optimization of key parameter ratios controlling dose. We believe this improves efficiency in drug discovery by enabling exploration of broad physicochemical space.


Assuntos
Preparações Farmacêuticas/metabolismo , Bibliotecas de Moléculas Pequenas/química , Área Sob a Curva , Proteínas Sanguíneas/química , Proteínas Sanguíneas/metabolismo , Desenho de Fármacos , Meia-Vida , Humanos , Interações Hidrofóbicas e Hidrofílicas , Preparações Farmacêuticas/química , Ligação Proteica , Curva ROC , Bibliotecas de Moléculas Pequenas/metabolismo , Bibliotecas de Moléculas Pequenas/farmacocinética
14.
J Neuropathol Exp Neurol ; 79(6): 626-640, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32417932

RESUMO

Choroid plexus (CP) may aid brain development and repair by secreting growth factors and neurotrophins for CSF streaming to ventricular and subventricular zones. Disrupted ventricular/subventricular zone progenitors and stem cells lead to CNS maldevelopment. Exploring models, we organ cultured the CP and transplanted fresh CP into a lateral ventricle of postnatal hydrocephalic (hyHTx) and nonhydrocephalic (nHTx) rats. After 60 days in vitro, the cultured choroid ependyma formed spherical rings with beating cilia. Cultured CP expressed endocytotic caveolin 1 and apical aquaporin 1 and absorbed horseradish peroxidase from medium. Transthyretin secretory protein was secreted by organ-cultured CP into medium throughout 60 days in vitro. Fresh CP, surviving at 1 week after lateral ventricle implantation of nHTx or hyHTx did not block CSF flow. Avascular 1-week transplants in vivo expressed caveolin 1, aquaporin 1, and transthyretin, indicating that grafted CP may secrete trophic proteins but not CSF. Our findings encourage further exploration on CP organ culture and grafting for translational strategies. Because transplanted CP, though not producing CSF, may secrete beneficial molecules for developing brain injured by hydrocephalus, we propose that upon CP removal in hydrocephalus surgery, the fractionated tissue could be transplanted back (ventricular autograft).


Assuntos
Plexo Corióideo , Hidrocefalia/cirurgia , Ventrículos Laterais/cirurgia , Enxerto Vascular/métodos , Animais , Modelos Animais de Doenças , Técnicas de Cultura de Órgãos , Ratos , Resultado do Tratamento
15.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-20088104

RESUMO

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease 2019 (COVID-19) has led to the rapid initiation of urgently needed clinical trials of repurposed drug combinations and monotherapies. These regimens were primarily relying on mechanism-of-action based selection of drugs, many of which have yielded positive in vitro but largely negative clinical outcomes. To overcome this challenge, we report the use of IDentif.AI, a platform that rapidly optimizes infectious disease (ID) combination therapy design using artificial intelligence (AI). In this study, IDentif.AI was implemented on a 12-drug candidate therapy search set representing over 530,000 possible drug combinations. IDentif.AI demonstrated that the optimal combination therapy against SARS-CoV-2 was comprised of remdesivir, ritonavir, and lopinavir, which mediated a 6.5-fold improvement in efficacy over remdesivir alone. Additionally, IDentif.AI showed hydroxychloroquine and azithromycin to be relatively ineffective. The identification of a clinically actionable optimal drug combination was completed within two weeks, with a 3-order of magnitude reduction in the number of tests typically needed. IDentif.AI analysis was also able to independently confirm clinical trial outcomes to date without requiring any data from these trials. The robustness of the IDentif.AI platform suggests that it may be applicable towards rapid development of optimal drug regimens to address current and future outbreaks.

16.
Cell Tissue Res ; 381(1): 141-161, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32065263

RESUMO

Foetal onset hydrocephalus is a disease starting early in embryonic life; in many cases it results from a cell junction pathology of neural stem (NSC) and neural progenitor (NPC) cells forming the ventricular zone (VZ) and sub-ventricular zone (SVZ) of the developing brain. This pathology results in disassembling of VZ and loss of NSC/NPC, a phenomenon known as VZ disruption. At the cerebral aqueduct, VZ disruption triggers hydrocephalus while in the telencephalon, it results in abnormal neurogenesis. This may explain why derivative surgery does not cure hydrocephalus. NSC grafting appears as a therapeutic opportunity. The present investigation was designed to find out whether this is a likely possibility. HTx rats develop hereditary hydrocephalus; 30-40% of newborns are hydrocephalic (hyHTx) while their littermates are not (nHTx). NSC/NPC from the VZ/SVZ of nHTx rats were cultured into neurospheres that were then grafted into a lateral ventricle of 1-, 2- or 7-day-old hyHTx. Once in the cerebrospinal fluid, neurospheres disassembled and the freed NSC homed at the areas of VZ disruption. A population of homed cells generated new multiciliated ependyma at the sites where the ependyma was missing due to the inherited pathology. Another population of NSC homed at the disrupted VZ differentiated into ßIII-tubulin+ spherical cells likely corresponding to neuroblasts that progressed into the parenchyma. The final fate of these cells could not be established due to the protocol used to label the grafted cells. The functional outcomes of NSC grafting in hydrocephalus remain open. The present study establishes an experimental paradigm of NSC/NPC therapy of foetal onset hydrocephalus, at the etiologic level that needs to be further explored with more analytical methodologies.


Assuntos
Hidrocefalia/terapia , Células-Tronco Neurais/transplante , Animais , Diferenciação Celular , Proliferação de Células , Neurogênese , Ratos
17.
Nat Ecol Evol ; 4(1): 46-49, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31844192

RESUMO

A global goal of no net loss of natural ecosystems or better has recently been proposed, but such a goal would require equitable translation to country-level contributions. Given the wide variation in ecosystem depletion, these could vary from net gain (for countries where restoration is needed), to managed net loss (in rare circumstances where natural ecosystems remain extensive and human development imperative is greatest). National contributions and international support for implementation also must consider non-area targets (for example, for threatened species) and socioeconomic factors such as the capacity to conserve and the imperative for human development.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Animais , Espécies em Perigo de Extinção , Humanos
18.
Nanoscale ; 11(30): 14434-14445, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31334737

RESUMO

Epitaxial graphene on SiC provides both an excellent source of high-quality graphene as well as an architecture to support its application. Although single-layer graphene on Si-face SiC has garnered extensive interest, many-layer graphene produced on C-face SiC could be significantly more robust for enabling applications. Little is known, however, about the structural properties related to the growth evolution at the buried interface for thick many-layer graphene. Using complementary X-ray scattering and neutron reflectivity as well as electron microscopy, we demonstrate that thick many-layer epitaxial graphene exhibits two vastly different length-scales of the buried interface roughness as a consequence of the Si sublimation that produces the graphene. Over long lateral length-scales the roughness is extremely large (hundreds of Å) and it varies proportionally to the number of graphene layers. In contrast, over much shorter lateral length-scales we observe an atomically abrupt interface with SiC terraces. Graphene near the buried interface exhibits a slightly expanded interlayer spacing (∼1%) and fluctuations of this spacing, indicating a tendency for disorder near the growth front. Nevertheless, Dirac cones are observed from the graphene while its domain size routinely reaches micron length-scales, indicating the persistence of high-quality graphene beginning just a short distance away from the buried interface. Discovering and reconciling the different length-scales of roughness by reflectivity was complicated by strong diffuse scattering and we provide a detailed discussion of how these difficulties were resolved. The insight from this analysis will be useful for other highly rough interfaces among broad classes of thin-film materials.

19.
Nat Commun ; 10(1): 893, 2019 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-30792391

RESUMO

Our understanding of the conformational and electrostatic determinants that underlie targeting of human leukocyte antigens (HLA) by anti-HLA alloantibodies is principally based upon in silico modelling. Here we provide a biochemical/biophysical and functional characterization of a human monoclonal alloantibody specific for a common HLA type, HLA-A*11:01. We present a 2.4 Å resolution map of the binding interface of this antibody on HLA-A*11:01 and compare the structural determinants with those utilized by T-cell receptor (TCR), killer-cell immunoglobulin-like receptor (KIR) and CD8 on the same molecule. These data provide a mechanistic insight into the paratope-epitope relationship between an alloantibody and its target HLA molecule in a biological context where other immune receptors are concomitantly engaged. This has important implications for our interpretation of serologic binding patterns of anti-HLA antibodies in sensitized individuals and thus, for the biology of human alloresponses.


Assuntos
Antígeno HLA-A11/química , Antígeno HLA-A11/metabolismo , Isoanticorpos/química , Isoanticorpos/metabolismo , Sequência de Aminoácidos , Anticorpos Monoclonais/química , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/metabolismo , Especificidade de Anticorpos , Complexo Antígeno-Anticorpo/química , Complexo Antígeno-Anticorpo/genética , Complexo Antígeno-Anticorpo/metabolismo , Sítios de Ligação de Anticorpos/genética , Cristalografia por Raios X , Epitopos/química , Epitopos/genética , Epitopos/metabolismo , Antígeno HLA-A11/genética , Humanos , Imunoglobulina G/química , Imunoglobulina G/genética , Imunoglobulina G/metabolismo , Isoanticorpos/genética , Modelos Moleculares , Biblioteca de Peptídeos , Conformação Proteica
20.
J Environ Qual ; 48(1): 117-126, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30640359

RESUMO

The site-specific nature of P fate and transport in drained areas exemplifies the need for additional data to guide implementation of conservation practices at the catchment scale. Total P (TP), dissolved reactive P (DRP), and total suspended solids (TSS) were monitored at five sites-two streams, two tile outlets, and a grassed waterway-in three agricultural subwatersheds (221.2-822.5 ha) draining to Black Hawk Lake in western Iowa. Median TP concentrations ranged from 0.034 to 1.490 and 0.008 to 0.055 mg P L for event and baseflow samples, respectively. The majority of P and TSS export occurred during precipitation events and high-flow conditions with greater than 75% of DRP, 66% of TP, and 59% of TSS export occurring during the top 25% of flows from all sites. In one subwatershed, a single event (annual recurrence interval < 1 yr) was responsible for 46.6, 84.0, and 81.0% of the annual export of TP, DRP, and TSS, respectively, indicating that frequent, small storms have the potential to result in extreme losses. Isolated monitoring of surface and drainage transport pathways indicated significant P and TSS losses occurring through drainage; over the 2-yr study period, the drainage pathway was responsible for 69.8, 59.2, and 82.6% of the cumulative TP, DRP, and TSS export, respectively. Finally, the results provided evidence that particulate P losses in drainage were greater than dissolved P losses. Understanding relationships between flow, precipitation, transport pathway, and P fraction at the catchment scale is needed for effective conservation practice implementation.


Assuntos
Agricultura , Fósforo , Iowa , Lagos , Poaceae
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