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1.
bioRxiv ; 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38464319

RESUMO

Pompe disease (PD) is a progressive myopathy caused by the aberrant accumulation of glycogen in skeletal and cardiac muscle resulting from the deficiency of the enzyme acid alpha-glucosidase (GAA). Administration of recombinant human GAA as enzyme replacement therapy (ERT) works well in alleviating the cardiac manifestations of PD but loses sustained benefit in ameliorating the skeletal muscle pathology. The limited efficacy of ERT in skeletal muscle is partially attributable to its inability to curb the accumulation of new glycogen produced by the muscle enzyme glycogen synthase 1 (GYS1). Substrate reduction therapies aimed at knocking down GYS1 expression represent a promising avenue to improve Pompe myopathy. However, finding specific inhibitors for GYS1 is challenging given the presence of the highly homologous GYS2 in the liver. Antisense oligonucleotides (ASOs) are chemically modified oligomers that hybridize to their complementary target RNA to induce their degradation with exquisite specificity. In the present study, we show that ASO-mediated Gys1 knockdown in the Gaa -/- mouse model of PD led to a robust reduction in glycogen accumulation in skeletal and cardiac muscle. In addition, combining Gys1 ASO with ERT further reduced glycogen content in muscle, eliminated autophagic buildup and lysosomal dysfunction, and improved motor function in Gaa -/- mice. Our results provide a strong foundation for further validation of the use of Gys1 ASO, alone or in combination with ERT, as a therapy for PD. We propose that early administration of Gys1 ASO in combination with ERT may be the key to preventative treatment options in PD.

2.
Commun Biol ; 6(1): 215, 2023 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-36823213

RESUMO

Considerable efforts have been made to characterize active enhancer elements, which can be annotated by accessible chromatin and H3 lysine 27 acetylation (H3K27ac). However, apart from poised enhancers that are observed in early stages of development and putative silencers, the functional significance of cis-regulatory elements lacking H3K27ac is poorly understood. Here we show that macroH2A histone variants mark a subset of enhancers in normal and cancer cells, which we coined 'macro-Bound Enhancers', that modulate enhancer activity. We find macroH2A variants localized at enhancer elements that are devoid of H3K27ac in a cell type-specific manner, indicating a role for macroH2A at inactive enhancers to maintain cell identity. In following, reactivation of macro-bound enhancers is associated with oncogenic programs in breast cancer and their repressive role is correlated with the activity of macroH2A2 as a negative regulator of BRD4 chromatin occupancy. Finally, through single cell epigenomic profiling of normal mammary stem cells derived from mice, we show that macroH2A deficiency facilitates increased activity of transcription factors associated with stem cell activity.


Assuntos
Proteínas Nucleares , Fatores de Transcrição , Camundongos , Animais , Proteínas Nucleares/metabolismo , Fatores de Transcrição/genética , Reprogramação Celular/genética , Elementos Facilitadores Genéticos , Cromatina/genética
3.
Adv Hematol ; 2022: 7992927, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36164495

RESUMO

Background: Convalescent plasma obtained from individuals who have recovered from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contains neutralizing antibodies to the virus and has been frequently used as a treatment in hospitalized patients with severe COVID-19. Methods: We conducted a retrospective, observational cohort study involving 96 hospitalized patients with severe COVID-19 who were allocated in a 1 : 1 ratio to having received either high antibody concentration convalescent plasma or low antibody concentration convalescent plasma. Quantitative measurements of IgG to the receptor-binding domain (RBD), the S1 subunit of the spike protein, and the SARS-CoV-2 nucleocapsid (N) protein were determined from donor plasma samples. The primary outcome was all-cause mortality within 30 days following convalescent plasma administration in regard to each of the three antibody domains. Results: Within the nucleocapsid antibody domain, death occurred in 22.2% of patients in the low antibody concentration group versus 23.5% in the high antibody concentration group (p=0.88). Within the RBD antibody domain, death occurred in 22.9% of patients in both the low and the high antibody concentration groups (p=1.0). Within the S1 subunit antibody domain, death occurred in 27.1% of patients in the low antibody concentration group versus 18.8% in the high antibody concentration group (p=0.33). Conclusions: No significant differences were observed between low and high concentration convalescent plasma in regard to overall mortality at 30 days, hospital length of stay, number of ventilator days, and subsequent receipt of invasive mechanical ventilation in patients who were previously not receiving mechanical ventilation. Trial Registration. This study was not associated with a clinical trial due to the retrospective nature of study design.

4.
J Neurosci ; 2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35623885

RESUMO

Zn2+ is an important contributor to ischemic brain injury and recent studies support the hypothesis that mitochondria are key sites of its injurious effects. In murine hippocampal slices (both sexes) subjected to oxygen glucose deprivation (OGD), we found that Zn2+ accumulation and its entry into mitochondria precedes and contributes to the induction of acute neuronal death. In addition, if the ischemic episode is short (and sublethal), there is ongoing Zn2+ accumulation in CA1 mitochondria after OGD that may contribute to their delayed dysfunction. Using this slice model of sublethal OGD, we have now examined Zn2+ contributions to the progression of changes evoked by OGD and occurring over 4-5 hours. We detected progressive mitochondrial depolarization occurring from ∼ 2 hours after ischemia, a large increase in spontaneous synaptic activity between 2-3 hours, and mitochondrial swelling and fragmentation at 4 hours. Blockade of the primary route for Zn2+ entry, the mitochondrial Ca2+ uniporter (MCU; with ruthenium red, RR) or Zn2+ chelation shortly after OGD withdrawal substantially attenuated the mitochondrial depolarization and the changes in synaptic activity. RR also largely reversed the mitochondrial swelling. Finally, using an in vivo rat (male) asphyxial cardiac arrest (CA) model of transient global ischemia, we found that ∼8 min asphyxia induces considerable injury of CA1 neurons 4 hours later that is associated with strong Zn2+ accumulation within many damaged mitochondria. These effects were substantially attenuated by infusion of RR upon reperfusion. Our findings highlight mitochondrial Zn2+ accumulation after ischemia as a possible target for neuroprotective therapy.SIGNIFICANCE STATEMENT:Brain ischemia is a leading cause of mortality and long-term disability that still lacks effective treatment. After transient ischemia delayed death of neurons occurs in vulnerable brain regions. There is a critical need to understand mechanisms of this delayed neurodegeneration which can be targeted for neuroprotection. We found progressive and long-lasting mitochondrial Zn2+ accumulation to occur in highly vulnerable CA1 neurons after ischemia. Here we demonstrate that this Zn2+ accumulation contributes strongly to deleterious events occurring after ischemia including mitochondrial dysfunction, swelling and structural changes. We suggest that this mitochondrial Zn2+ entry may constitute a promising target for development of therapeutic interventions to be delivered after termination of an episode of transient global ischemia.

5.
PLoS One ; 17(3): e0257930, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35259162

RESUMO

The novel coronavirus, SARS-CoV-2 that causes COVID-19 has resulted in the death of nearly 4 million people within the last 18 months. While preventive vaccination, and monoclonal antibody therapies have been rapidly developed and deployed, early in the pandemic the use of COVID-19 convalescent plasma (CCP) was a common means of passive immunization with a theoretical risk of antibody-dependent enhancement (ADE) of viral infection. Though vaccines elicit a strong and protective immune response and transfusion of CCP with high titers of neutralization activity are correlated with better clinical outcomes, the question of whether antibodies in CCP can enhance infection of SARS-CoV-2 has not been directly addressed. In this study, we analyzed for and observed passive transfer of neutralization activity with CCP transfusion. Furthermore, to specifically understand if antibodies against the spike protein (S) enhance infection, we measured the anti-S IgG, IgA, and IgM responses and adapted retroviral-pseudotypes to measure virus neutralization with target cells expressing the ACE2 virus receptor and the Fc alpha receptor (FcαR) or Fc gamma receptor IIA (FcγRIIA). Whereas neutralizing activity of CCP correlated best with higher titers of anti-S IgG antibodies, the neutralizing titer was not affected when Fc receptors were present on target cells. These observations support the absence of antibody-dependent enhancement of infection (ADE) by IgG and IgA isotypes found in CCP. The results presented, therefore, not only supports the therapeutic use of currently available antibody-based treatment, including the continuation of CCP transfusion strategies, but also the use of various vaccine platforms in a prophylactic approach.


Assuntos
COVID-19/terapia , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/metabolismo , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/uso terapêutico , COVID-19/virologia , Feminino , Células HEK293 , Humanos , Imunização Passiva , Imunoglobulina A/sangue , Imunoglobulina A/uso terapêutico , Imunoglobulina G/sangue , Imunoglobulina G/uso terapêutico , Masculino , Pessoa de Meia-Idade , Testes de Neutralização , Receptores de IgG/genética , Receptores de IgG/metabolismo , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/metabolismo , Adulto Jovem , Soroterapia para COVID-19
6.
J Transl Med ; 20(1): 21, 2022 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-34998409

RESUMO

BACKGROUND: Pathogenic gain of function variants in Valosin-containing protein (VCP) cause a unique disease characterized by inclusion body myopathy with early-onset Paget disease of bone and frontotemporal dementia (also known as Multisystem proteinopathy (MSP)). Previous studies in drosophila models of VCP disease indicate treatment with VCP inhibitors mitigates disease pathology. Earlier-generation VCP inhibitors display off-target effects and relatively low therapeutic potency. New generation of VCP inhibitors needs to be evaluated in a mouse model of VCP disease. In this study, we tested the safety and efficacy of a novel and potent VCP inhibitor, CB-5083 using VCP patient-derived myoblast cells and an animal model of VCP disease. METHODS: First, we analyzed the effect of CB-5083 in patient-derived myoblasts on the typical disease autophagy and TDP-43 profile by Western blot. Next, we determined the maximum tolerated dosage of CB-5083 in mice and treated the 2-month-old VCPR155H/R155H mice for 5 months with 15 mg/kg CB-5083. We analyzed motor function monthly by Rotarod; and we assessed the end-point blood toxicology, and the muscle and brain pathology, including autophagy and TDP-43 profile, using Western blot and immunohistochemistry. We also treated 12-month-old VCPR155H/+ mice for 6 months and performed similar analysis. Finally, we assessed the potential side effects of CB-5083 on retinal function, using electroretinography in chronically treated VCPR155H/155H mice. RESULTS: In vitro analyses using patient-derived myoblasts confirmed that CB-5083 can modulate expression of the proteins in the autophagy pathways. We found that chronic CB-5083 treatment is well tolerated in the homozygous mice harboring patient-specific VCP variant, R155H, and can ameliorate the muscle pathology characteristic of the disease. VCP-associated pathology biomarkers, such as elevated TDP-43 and p62 levels, were significantly reduced. Finally, to address the potential adverse effect of CB-5083 on visual function observed in a previous oncology clinical trial, we analyzed retinal function in mice treated with moderate doses of CB-5083 for 5 months and documented the absence of permanent ocular toxicity. CONCLUSIONS: Altogether, these findings suggest that long-term use of CB-5083 by moderate doses is safe and can improve VCP disease-associated muscle pathology. Our results provide translationally relevant evidence that VCP inhibitors could be beneficial in the treatment of VCP disease.


Assuntos
Doenças Musculares , Animais , Humanos , Corpos de Inclusão/metabolismo , Indóis , Camundongos , Músculos/metabolismo , Doenças Musculares/etiologia , Doenças Musculares/metabolismo , Mutação , Pirimidinas , Proteína com Valosina/metabolismo
7.
bioRxiv ; 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34545365

RESUMO

The novel coronavirus SARS-CoV2, which causes COVID-19, has resulted in the death of nearly 4 million people within the last 18 months. While preventive vaccination and monoclonal antibody therapies have been rapidly developed and deployed, early in the pandemic the use of COVID-19 convalescent plasma (CCP) was a common means of passive immunization, with the theoretical risk of antibody-dependent enhancement (ADE) of viral infection remaining undetermined. Though vaccines elicit a strong and protective immune response, and transfusion of CCP with high titers of neutralization activity are correlated with better clinical outcomes, the question of whether antibodies in CCP can enhance infection of SARS-CoV2 has not been directly addressed. In this study, we analyzed for and observed passive transfer of neutralization activity with CCP transfusion. Furthermore, to specifically understand if antibodies against the spike protein (S) enhance infection, we measured the anti-S IgG, IgA, and IgM responses and adapted retroviral-pseudotypes to measure virus neutralization with target cells expressing the ACE2 virus receptor and the Fc alpha receptor (FcαR) or Fc gamma receptor IIA (FcγRIIA). Whereas neutralizing activity of CCP correlated best with higher titers of anti-S IgG antibodies, the neutralizing titer was not affected when Fc receptors were present on target cells. These observations support the absence of antibody-dependent enhancement of infection (ADE) by IgG and IgA isotypes found in CCP. The results presented, therefore, support the clinical use of currently available antibody-based treatment including the continued study of CCP transfusion strategies.

8.
Biomedicines ; 9(5)2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33946782

RESUMO

Zinc is a highly abundant cation in the brain, essential for cellular functions, including transcription, enzymatic activity, and cell signaling. However, zinc can also trigger injurious cascades in neurons, contributing to the pathology of neurodegenerative diseases. Mitochondria, critical for meeting the high energy demands of the central nervous system (CNS), are a principal target of the deleterious actions of zinc. An increasing body of work suggests that intracellular zinc can, under certain circumstances, contribute to neuronal damage by inhibiting mitochondrial energy processes, including dissipation of the mitochondrial membrane potential (MMP), leading to ATP depletion. Additional consequences of zinc-mediated mitochondrial damage include reactive oxygen species (ROS) generation, mitochondrial permeability transition, and excitotoxic calcium deregulation. Zinc can also induce mitochondrial fission, resulting in mitochondrial fragmentation, as well as inhibition of mitochondrial motility. Here, we review the known mechanisms responsible for the deleterious actions of zinc on the organelle, within the context of neuronal injury associated with neurodegenerative processes. Elucidating the critical contributions of zinc-induced mitochondrial defects to neurotoxicity and neurodegeneration may provide insight into novel therapeutic targets in the clinical setting.

9.
medRxiv ; 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33688667

RESUMO

BACKGROUND: The novel coronavirus, SARS-CoV2 that causes COVID-19 has resulted in the death of more than 2.31 million people within the last year and yet no cure exists. Whereas passive immunization with COVID-19 convalescent plasma (CCP) provides a safe and viable option, selection of optimal units for therapy and lack of clear therapeutic benefit from transfusion remain as barriers to the use of CCP. STUDY DESIGN AND METHODS: To identify plasma that is expected to benefit recipients, we measured anti-SARS-CoV2 antibody levels using clinically available serological assays and correlated with the neutralizing activity of CCP from donors. Neutralizing titer of plasma samples was measured by assaying infectivity of SARS-CoV-2 spike protein pseudotyped retrovirus particles in the presence of dilutions of plasma samples. We also used this assay to identify evidence of passive transfusion of neutralizing activity in CCP recipients. RESULTS: Viral neutralization and anti-spike protein antibodies in 109 samples from 87 plasma donors were highly varied but modestly correlated with each other. Recipients who died of COVID-19 were found to have been transfused with units with lower anti-spike antibody levels and neutralizing activity. Passive transfer of neutralization activity was documented in 62% of antibody naive plasma recipients. CONCLUSIONS: Since viral neutralization is the goal of CCP transfusion, our observations not only support the use of anti-spike SARS-CoV2 serology tests to identify beneficial CCP units, but also support the therapeutic value of convalescent plasma with high titers of anti-spike antibodies.

11.
Clin Infect Dis ; 72(6): 1051-1054, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-32539111

RESUMO

A kidney transplant patient without known tick exposure developed encephalitis 3 weeks after transplantation. During the transplant hospitalization, the patient had received a blood transfusion from an asymptomatic donor later discovered to have been infected with Powassan virus. Here, we describe a probable instance of transfusion-transmitted Powassan virus infection.


Assuntos
Vírus da Encefalite Transmitidos por Carrapatos , Encefalite Transmitida por Carrapatos , Encefalite , Transplante de Rim , Viroses , Animais , Transfusão de Sangue , Encefalite/diagnóstico , Encefalite/etiologia , Encefalite Transmitida por Carrapatos/diagnóstico , Humanos , Transplante de Rim/efeitos adversos
12.
Exp Neurol ; 325: 113161, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31881218

RESUMO

Excitotoxic Ca2+ accumulation contributes to ischemic neurodegeneration, and Ca2+ can enter the mitochondria through the mitochondrial calcium uniporter (MCU) to promote mitochondrial dysfunction. Yet, Ca2+-targeted therapies have met limited success. A growing body of evidence has highlighted the underappreciated importance of Zn2+, which also accumulates in neurons after ischemia and can induce mitochondrial dysfunction and cell death. While studies have indicated that Zn2+ can also enter the mitochondria through the MCU, the specificity of the pore's role in Zn2+-triggered injury is still debated. Present studies use recently available MCU knockout mice to examine how the deletion of this channel impacts deleterious effects of cytosolic Zn2+ loading. In cultured cortical neurons from MCU knockout mice, we find significantly reduced mitochondrial Zn2+ accumulation. Correspondingly, these neurons were protected from both acute and delayed Zn2+-triggered mitochondrial dysfunction, including mitochondrial reactive oxygen species generation, depolarization, swelling and inhibition of respiration. Furthermore, when toxic extramitochondrial effects of Ca2+ entry were moderated, both cultured neurons (exposed to Zn2+) and CA1 neurons of hippocampal slices (subjected to prolonged oxygen glucose deprivation to model ischemia) from MCU knockout mice displayed decreased neurodegeneration. Finally, to examine the therapeutic applicability of these findings, we added an MCU blocker after toxic Zn2+ exposure in wildtype neurons (to induce post-insult MCU blockade). This significantly attenuated the delayed evolution of both mitochondrial dysfunction and neurotoxicity. These data-combining both genetic and pharmacologic tools-support the hypothesis that Zn2+ entry through the MCU is a critical contributor to ischemic neurodegeneration that could be targeted for neuroprotection.


Assuntos
Canais de Cálcio/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Degeneração Neural/metabolismo , Neurônios/metabolismo , Zinco/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Maleato de Dizocilpina/farmacologia , Camundongos , Camundongos Knockout , Mitocôndrias/efeitos dos fármacos , Degeneração Neural/patologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Fármacos Neuroprotetores/farmacologia
13.
Gigascience ; 8(8)2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31363753

RESUMO

Trap-based surveillance strategies are widely used for monitoring of invasive insect species, aiming to detect newly arrived exotic taxa as well as track the population levels of established or endemic pests. Where these surveillance traps have low specificity and capture non-target endemic species in excess of the target pests, the need for extensive specimen sorting and identification creates a major diagnostic bottleneck. While the recent development of standardized molecular diagnostics has partly alleviated this requirement, the single specimen per reaction nature of these methods does not readily scale to the sheer number of insects trapped in surveillance programmes. Consequently, target lists are often restricted to a few high-priority pests, allowing unanticipated species to avoid detection and potentially establish populations. DNA metabarcoding has recently emerged as a method for conducting simultaneous, multi-species identification of complex mixed communities and may lend itself ideally to rapid diagnostics of bulk insect trap samples. Moreover, the high-throughput nature of recent sequencing platforms could enable the multiplexing of hundreds of diverse trap samples on a single flow cell, thereby providing the means to dramatically scale up insect surveillance in terms of both the quantity of traps that can be processed concurrently and number of pest species that can be targeted. In this review of the metabarcoding literature, we explore how DNA metabarcoding could be tailored to the detection of invasive insects in a surveillance context and highlight the unique technical and regulatory challenges that must be considered when implementing high-throughput sequencing technologies into sensitive diagnostic applications.


Assuntos
Código de Barras de DNA Taxonômico , Genoma de Inseto , Sequenciamento de Nucleotídeos em Larga Escala , Insetos/classificação , Insetos/genética , Animais , Biodiversidade , Biologia Computacional/métodos , Código de Barras de DNA Taxonômico/métodos , Bases de Dados Genéticas , Marcadores Genéticos , Sequenciamento de Nucleotídeos em Larga Escala/métodos
14.
J Neuropathol Exp Neurol ; 78(7): 655-664, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31150090

RESUMO

Mitochondrial Zn2+ accumulation, particularly in CA1 neurons, occurs after ischemia and likely contributes to mitochondrial dysfunction and subsequent neurodegeneration. However, the relationship between mitochondrial Zn2+ accumulation and their disruption has not been examined at the ultrastructural level in vivo. We employed a cardiac arrest model of transient global ischemia (TGI), combined with Timm's sulfide silver labeling, which inserts electron dense metallic silver granules at sites of labile Zn2+ accumulation, and used transmission electron microscopy (TEM) to examine subcellular loci of the Zn2+ accumulation. In line with prior studies, TGI-induced damage to CA1 was far greater than to CA3 pyramidal neurons, and was substantially progressive in the hours after reperfusion (being significantly greater after 4- than 1-hour recovery). Intriguingly, TEM examination of Timm's-stained sections revealed substantial Zn2+ accumulation in many postischemic CA1 mitochondria, which was strongly correlated with their swelling and disruption. Furthermore, paralleling the evolution of neuronal injury, both the number of mitochondria containing Zn2+ and the degree of their disruption were far greater at 4- than 1-hour recovery. These data provide the first direct characterization of Zn2+ accumulation in CA1 mitochondria after in vivo TGI, and support the idea that targeting these events could yield therapeutic benefits.


Assuntos
Região CA1 Hipocampal/metabolismo , Ataque Isquêmico Transitório/metabolismo , Mitocôndrias/metabolismo , Células Piramidais/metabolismo , Zinco/metabolismo , Animais , Região CA1 Hipocampal/citologia , Região CA1 Hipocampal/patologia , Região CA3 Hipocampal/citologia , Região CA3 Hipocampal/metabolismo , Região CA3 Hipocampal/patologia , Morte Celular , Ataque Isquêmico Transitório/patologia , Masculino , Mitocôndrias/patologia , Mitocôndrias/ultraestrutura , Dilatação Mitocondrial , Ratos , Ratos Wistar
15.
Neuroscientist ; 25(2): 126-138, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-29742958

RESUMO

Ischemic stroke is a major cause of death and disabilities worldwide, and it has been long hoped that improved understanding of relevant injury mechanisms would yield targeted neuroprotective therapies. While Ca2+ overload during ischemia-induced glutamate excitotoxicity has been identified as a major contributor, failures of glutamate targeted therapies to achieve desired clinical efficacy have dampened early hopes for the development of new treatments. However, additional studies examining possible contributions of Zn2+, a highly prevalent cation in the brain, have provided new insights that may help to rekindle the enthusiasm. In this review, we discuss both old and new findings yielding clues as to sources of the Zn2+ that accumulates in many forebrain neurons after ischemia, and mechanisms through which it mediates injury. Specifically, we highlight the growing evidence of important Zn2+ effects on mitochondria in promoting neuronal injury. A key focus has been to examine Zn2+ contributions to the degeneration of highly susceptible hippocampal pyramidal neurons. Recent studies provide evidence of differences in sources of Zn2+ and its interactions with mitochondria in CA1 versus CA3 neurons that may pertain to their differential vulnerabilities in disease. We propose that Zn2+-induced mitochondrial dysfunction is a critical and potentially targetable early event in the ischemic neuronal injury cascade, providing opportunities for the development of novel neuroprotective strategies to be delivered after transient ischemia.


Assuntos
Isquemia Encefálica/metabolismo , Hipocampo/lesões , Hipocampo/metabolismo , Mitocôndrias/metabolismo , Acidente Vascular Cerebral/metabolismo , Zinco/metabolismo , Animais , Apoptose , Isquemia Encefálica/complicações , Cálcio/metabolismo , Humanos , Células Piramidais/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Acidente Vascular Cerebral/complicações
16.
J Clin Apher ; 34(4): 499-502, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30592528

RESUMO

We report the impact of measuring the hematocrit (HCT) of blood prime units (BPUs) on postprocedure patient HCT values in a small child with transverse myelitis undergoing therapeutic plasma exchange (TPE). Initially, the BPU HCT values were not measured, according to our apheresis policy of using our blood center's estimated HCT value. This approach resulted in unexpected increasing elevations of our patient's post-TPE HCT after the first two TPE procedures. Subsequent measurement of the BPU HCT prior to use stabilized the patient's post-TPE HCT. To our knowledge, this is the first case report describing the impact of using the measured BPU HCT vs the estimated HCT for very small children undergoing therapeutic apheresis. Our standard operating procedure for very small children has been updated after this patient's case to include measurements of the HCT values of BPUs for children who weigh 10 kg or less.


Assuntos
Hematócrito , Pediatria/métodos , Troca Plasmática/métodos , Peso Corporal , Criança , Humanos , Mielite Transversa/terapia
17.
Transfusion ; 58(8): 1965-1972, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30198607

RESUMO

BACKGROUND: A prior practice survey revealed variations in the management of patients with sickle cell disease (SCD) and stressed the need for comprehensive guidelines. Here we discuss: 1) common indications for red blood cell exchange (RCE), 2) options for access, 3) how to prepare the red blood cells (RBCs) to be used for RCE, 4) target hemoglobin (Hb) and/or hematocrit (Hct) and HbS level, 5) RBC depletion/RCE, and 6) some complications that may ensue. STUDY DESIGN AND METHODS: Fifteen physicians actively practicing apheresis from 14 institutions representing different areas within the United States discussed how they manage RCE for patients with SCD. RESULTS: Simple transfusion is recommended to treat symptomatic anemia with Hb level of less than 9 g/dL. RCE is indicated to prevent or treat complications arising from the presence of HbS. The most important goals are reduction of HbS while also preventing hyperviscosity. The usual goals are a target HbS level of not more than 30% and Hct level of less than 30%. CONCLUSION: Although a consensus as to protocol details may not be possible, there are areas of agreement in the management of these patients, for example, that it is optimal to avoid hyperviscosity and iron overload, that a target Hb S level in the range of 30% is generally desirable, and that RCE as an acute treatment for pain crisis in the absence of other acute or chronic conditions is ordinarily discouraged.


Assuntos
Anemia Falciforme/terapia , Transfusão de Eritrócitos/métodos , Viscosidade Sanguínea , Gerenciamento Clínico , Hemoglobina Falciforme/análise , Humanos , Sobrecarga de Ferro/prevenção & controle , Estados Unidos
18.
Exp Neurol ; 302: 181-195, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29355498

RESUMO

Excitotoxic Zn2+ and Ca2+ accumulation contributes to neuronal injury after ischemia or prolonged seizures. Synaptically released Zn2+ can enter postsynaptic neurons via routes including voltage sensitive Ca2+ channels (VSCC), and, more rapidly, through Ca2+ permeable AMPA channels. There are also intracellular Zn2+ binding proteins which can either buffer neuronal Zn2+ influx or release bound Zn2+ into the cytosol during pathologic conditions. Studies in culture highlight mitochondria as possible targets of Zn2+; cytosolic Zn2+ can enter mitochondria and induce effects including loss of mitochondrial membrane potential (ΔΨm), mitochondrial swelling, and reactive oxygen species (ROS) generation. While brief (5 min) neuronal depolarization (to activate VSCC) in the presence of 300 µM Zn2+ causes substantial delayed neurodegeneration, it only mildly impacts acute mitochondrial function, raising questions as to contributions of Zn2+-induced mitochondrial dysfunction to neuronal injury. Using brief high (90 mM) K+/Zn2+ exposures to mimic neuronal depolarization and extracellular Zn2+ accumulation as may accompany ischemia in vivo, we examined effects of disrupted cytosolic Zn2+ buffering and/or the presence of Ca2+, and made several observations: 1. Mild disruption of cytosolic Zn2+ buffering-while having little effects alone-markedly enhanced mitochondrial Zn2+ accumulation and dysfunction (including loss of ∆Ψm, ROS generation, swelling and respiratory inhibition) caused by relatively low (10-50 µM) Zn2+ with high K+. 2. The presence of Ca2+ during the Zn2+ exposure decreased cytosolic and mitochondrial Zn2+ accumulation, but markedly exacerbated the consequent dysfunction. 3. Paralleling effects on mitochondria, disruption of buffering and presence of Ca2+ enhanced Zn2+-induced neurodegeneration. 4. Zn2+ chelation after the high K+/Zn2+ exposure attenuated both ROS production and neurodegeneration, supporting the potential utility of delayed interventions. Taken together, these data lend credence to the idea that in pathologic states that impair cytosolic Zn2+ buffering, slow uptake of Zn2+ along with Ca2+ into neurons via VSCC can disrupt the mitochondria and induce neurodegeneration.


Assuntos
Cálcio/metabolismo , Citosol/metabolismo , Mitocôndrias/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Zinco/metabolismo , Animais , Carbonil Cianeto p-Trifluormetoxifenil Hidrazona/farmacologia , Morte Celular/efeitos dos fármacos , Células Cultivadas , Córtex Cerebral/citologia , Citosol/efeitos dos fármacos , Embrião de Mamíferos , Potencial da Membrana Mitocondrial/fisiologia , Camundongos , Camundongos Endogâmicos ICR , N-Metilaspartato/farmacologia , Neurônios/efeitos dos fármacos , Oligonucleotídeos/farmacologia , Potássio/farmacologia , Ionóforos de Próton/farmacologia , Piridinas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Zinco/farmacologia
19.
Sensors (Basel) ; 18(1)2018 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-29342101

RESUMO

Recent advances in remote sensed imagery and geospatial image processing using unmanned aerial vehicles (UAVs) have enabled the rapid and ongoing development of monitoring tools for crop management and the detection/surveillance of insect pests. This paper describes a (UAV) remote sensing-based methodology to increase the efficiency of existing surveillance practices (human inspectors and insect traps) for detecting pest infestations (e.g., grape phylloxera in vineyards). The methodology uses a UAV integrated with advanced digital hyperspectral, multispectral, and RGB sensors. We implemented the methodology for the development of a predictive model for phylloxera detection. In this method, we explore the combination of airborne RGB, multispectral, and hyperspectral imagery with ground-based data at two separate time periods and under different levels of phylloxera infestation. We describe the technology used-the sensors, the UAV, and the flight operations-the processing workflow of the datasets from each imagery type, and the methods for combining multiple airborne with ground-based datasets. Finally, we present relevant results of correlation between the different processed datasets. The objective of this research is to develop a novel methodology for collecting, processing, analising and integrating multispectral, hyperspectral, ground and spatial data to remote sense different variables in different applications, such as, in this case, plant pest surveillance. The development of such methodology would provide researchers, agronomists, and UAV practitioners reliable data collection protocols and methods to achieve faster processing techniques and integrate multiple sources of data in diverse remote sensing applications.

20.
J Clin Apher ; 33(3): 371-379, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29071747

RESUMO

We surveyed multiple apheresis centers represented by the authors for their clinical approach to the management of anticoagulation issues during therapeutic plasma exchange (TPE). We present the results of their practices and a review of the pertinent literature. As plasma is removed during TPE, replacement with all or partial non-plasma-containing fluids (eg, 5% albumin) may lead to significant changes in hemostasis. These changes are amplified in patients who are receiving anticoagulation. We discuss various anticoagulants as well as the monitoring and adjustment of anticoagulation before, during, and after TPE. No single guideline can be applied, but rather, patients must be monitored individually, taking into account their often complex clinical conditions and medication profiles.


Assuntos
Anticoagulantes/uso terapêutico , Troca Plasmática/métodos , Gerenciamento Clínico , Monitoramento de Medicamentos/métodos , Humanos , Troca Plasmática/efeitos adversos
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