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1.
Int J Mol Sci ; 23(3)2022 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-35163322

RESUMEN

Acute ischemic stroke is the leading cause of morbidity and mortality worldwide. Recombinant tissue plasminogen activator (rtPA) is the only agent clinically approved by FDA for patients with acute ischemic stroke. However, delayed treatment of rtPA (e.g., more than 3 h after stroke onset) exacerbates ischemic brain damage by causing intracerebral hemorrhage and increasing neurotoxicity. In the present study, we investigated whether the neuroprotant otaplimastat reduced delayed rtPA treatment-evoked neurotoxicity in male Sprague Dawley rats subjected to embolic middle cerebral artery occlusion (eMCAO). Otaplimastat reduced cerebral infarct size and edema and improved neurobehavioral deficits. In particular, otaplimastat markedly reduced intracerebral hemorrhagic transformation and mortality triggered by delayed rtPA treatment, consequently extending the therapeutic time window of rtPA. We further found that ischemia-evoked extracellular matrix metalloproteases (MMPs) expression was closely correlated with cerebral hemorrhagic transformation and brain damage. In ischemic conditions, delayed rtPA treatment further increased brain injury via synergistic expression of MMPs in vascular endothelial cells. In oxygen-glucose-deprived endothelial cells, otaplimastat suppressed the activity rather than protein expression of MMPs by restoring the level of tissue inhibitor of metalloproteinase (TIMP) suppressed in ischemia, and consequently reduced vascular permeation. This paper shows that otaplimastat under clinical trials is a new drug which can inhibit stroke on its own and extend the therapeutic time window of rtPA, especially when administered in combination with rtPA.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Acetamidas , Animales , Isquemia Encefálica/tratamiento farmacológico , Isquemia Encefálica/metabolismo , Hemorragia Cerebral/tratamiento farmacológico , Hemorragia Cerebral/metabolismo , Modelos Animales de Enfermedad , Células Endoteliales/metabolismo , Fibrinolíticos/uso terapéutico , Humanos , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/metabolismo , Masculino , Metaloproteinasas de la Matriz/metabolismo , Quinazolinas/uso terapéutico , Quinazolinonas , Ratas , Ratas Sprague-Dawley , Accidente Cerebrovascular/metabolismo , Terapia Trombolítica , Activador de Tejido Plasminógeno
2.
Ann Neurol ; 87(2): 233-245, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31721277

RESUMEN

OBJECTIVE: Otaplimastat is a neuroprotectant that inhibits matrix metalloprotease pathway, and reduces edema and intracerebral hemorrhage induced by recombinant tissue plasminogen activator (rtPA) in animal stroke models. We aimed to assess the safety and efficacy of otaplimastat in patients receiving rtPA. METHODS: This was a phase 2, 2-part, multicenter trial in stroke patients (19-80 years old) receiving rtPA. Intravenous otaplimastat was administered <30 minutes after rtPA. Stage 1 was a single-arm, open-label safety study in 11 patients. Otaplimastat 80 mg was administered twice daily for 3 days. Stage 2 was a randomized, double-blind, placebo-controlled study involving 69 patients, assigned (1:1:1) to otaplimastat 40 mg, otaplimastat 80 mg, or a placebo. The primary endpoint was the occurrence of parenchymal hematoma (PH) on day 1. Secondary endpoints included serious adverse events (SAEs), mortality, and modified Rankin scale (mRS) distribution at 90 days (clinicaltrials.gov identifier: NCT02787278). RESULTS: No safety issues were encountered in stage 1. The incidence of PH during stage 2 was comparable: 0 of 22 with the placebo, 0 of 22 with otaplimastat 40 mg, and 1 of 21 with the 80 mg dose. No differences in SAEs (13%, 17%, 14%) or death (8.3%, 4.2%, 4.8%) were observed among the 3 groups. Three adverse events (chills, muscle rigidity, hepatotoxicity) were judged to be related to otaplimastat. INTERPRETATION: Intravenous otaplimastat adjunctive therapy in patients receiving rtPA is feasible and generally safe. The functional efficacy of otaplimastat needs to be investigated with further large trials. ANN NEUROL 2020;87:233-245.


Asunto(s)
Acetamidas/uso terapéutico , Isquemia Encefálica/tratamiento farmacológico , Quinazolinonas/uso terapéutico , Accidente Cerebrovascular/tratamiento farmacológico , Acetamidas/efectos adversos , Administración Intravenosa , Adulto , Anciano , Anciano de 80 o más Años , Isquemia Encefálica/complicaciones , Método Doble Ciego , Femenino , Fibrinolíticos/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Fármacos Neuroprotectores/efectos adversos , Fármacos Neuroprotectores/uso terapéutico , Quinazolinonas/efectos adversos , Accidente Cerebrovascular/complicaciones , Activador de Tejido Plasminógeno/uso terapéutico , Resultado del Tratamiento , Adulto Joven
3.
Molecules ; 25(8)2020 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-32294954

RESUMEN

(1S,5R)-4-((E)-3,4-dihydroxy-5-methoxystryryl)-6,6-dimethylbicylco[3.1.1]hept-3-en-2-one (SP-8356) is a novel (1S)-(-)-verbenone derivative that is currently in preclinical development for the treatment of ischemic stroke and atherosclerosis. This report aimed at characterization of the metabolism and pharmacokinetic properties of SP-8356. Following intravenous dose in rats and dogs, plasma concentrations of SP-8356 declined rapidly with high clearance (CL) and short half-life; after oral administration in both species, its plasma levels were below the quantitation limit. Fourteen circulating metabolites, formed by mono-oxygenation, demethylation, glucuronidation, catechol O-methylation, sulfation and oxidation (bioactivation) followed by glutathione (GSH) conjugation, were tentatively identified in both species. Urinary excretion of SP-8356 appeared to be minimal in rats, compared to its metabolites. GSH conjugate of SP-8356 was also formed during incubation with rat liver S9 fraction consistent with oxidative bioactivation; this bioactivation was almost completely inhibited by the cofactors for glucuronidation, sulfation and methylation, indicating that it may be abolished by competing metabolic reactions in the body. The human pharmacokinetics of SP-8356 was predicted to be similar to that of the animals based on the current in vitro metabolic stability results. In summary, rapid phase II metabolism appears to be mainly responsible for its suboptimal pharmacokinetics, such as high CL and low oral absorption. Because of competing metabolic reactions, potential safety risks related to SP-8356 bioactivation may be low.


Asunto(s)
Monoterpenos Bicíclicos/metabolismo , Monoterpenos Bicíclicos/farmacocinética , Hígado/efectos de los fármacos , Administración Intravenosa , Administración Oral , Animales , Monoterpenos Bicíclicos/administración & dosificación , Monoterpenos Bicíclicos/sangre , Cromatografía Líquida de Alta Presión , Perros , Glutatión/metabolismo , Semivida , Humanos , Hígado/metabolismo , Masculino , Tasa de Depuración Metabólica/fisiología , Farmacocinética , Ratas , Ratas Sprague-Dawley
4.
Bioorg Med Chem ; 25(4): 1394-1405, 2017 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-28089588

RESUMEN

Astrocytes play a key role in brain homeostasis, protecting neurons against neurotoxic stimuli such as oxidative stress. Therefore, the neuroprotective therapeutics that enhance astrocytic functionality has been regarded as a promising strategy to reduce brain damage. We previously reported that ciclopirox, a well-known antifungal N-hydroxypyridone compound, protects astrocytes from oxidative stress by enhancing mitochondrial function. Using the N-hydroxypyridone scaffold, we have synthesized a series of cytoprotective derivatives. Mitochondrial activity assay showed that N-hydroxypyridone derivatives with biphenyl group have comparable to better protective effects than ciclopirox in astrocytes exposed to H2O2. N-hydroxypyridone derivatives, especially 11g, inhibited H2O2-induced deterioration of mitochondrial membrane potential and oxygen consumption rate, and significantly improved cell viability of astrocytes. The results indicate that the N-hydroxypyridone motif can provide a novel cytoprotective scaffold for astrocytes via enhancing mitochondrial functionality.


Asunto(s)
Astrocitos/efectos de los fármacos , Descubrimiento de Drogas , Peróxido de Hidrógeno/antagonistas & inhibidores , Mitocondrias/efectos de los fármacos , Piridonas/farmacología , Animales , Muerte Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Peróxido de Hidrógeno/farmacología , Mitocondrias/metabolismo , Estructura Molecular , Piridonas/síntesis química , Piridonas/química , Ratas , Ratas Sprague-Dawley , Relación Estructura-Actividad
5.
J Biol Chem ; 289(32): 22183-95, 2014 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-24973211

RESUMEN

Activated caspases play a central role in the execution of apoptosis by cleaving endogenous substrates. Here, we developed a high throughput screening method to identify novel substrates for caspase-3 in a neuronal cell line. Critical steps in our strategy consist of two-dimensional electrophoresis-based protein separation and in vitro caspase-3 incubation of immobilized proteins to sort out direct substrates. Among 46 putative substrates identified in MN9D neuronal cells, we further evaluated whether caspase-3-mediated cleavage of anamorsin, a recently recognized cell death-defying factor in hematopoiesis, is a general feature of apoptosis. In vitro and cell-based cleavage assays indicated that anamorsin was specifically cleaved by caspase-3 but not by other caspases, generating 25- and 10-kDa fragments. Thus, in apoptosis of neuronal and non-neuronal cells induced by various stimuli including staurosporine, etoposide, or 6-hydroxydopamine, the cleavage of anamorsin was found to be blocked in the presence of caspase inhibitor. Among four tetrapeptide consensus DXXD motifs existing in anamorsin, we mapped a specific cleavage site for caspase-3 at DSVD(209)↓L. Intriguingly, the 25-kDa cleaved fragment of anamorsin was also detected in post-mortem brains of Alzheimer and Parkinson disease patients. Although the RNA interference-mediated knockdown of anamorsin rendered neuronal cells more vulnerable to staurosporine treatment, reintroduction of full-length anamorsin into an anamorsin knock-out stromal cell line made cells resistant to staurosporine-induced caspase activation, indicating the antiapoptotic function of anamorsin. Taken together, our approach seems to be effective to identify novel substrates for caspases and has the potential to provide meaningful insights into newly identified substrates involved in neurodegenerative processes.


Asunto(s)
Caspasa 3/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Degeneración Nerviosa/metabolismo , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/metabolismo , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Animales , Apoptosis/fisiología , Sitios de Unión , Estudios de Casos y Controles , Línea Celular , Células Cultivadas , Femenino , Técnicas de Silenciamiento del Gen , Ensayos Analíticos de Alto Rendimiento , Humanos , Péptidos y Proteínas de Señalización Intracelular/química , Péptidos y Proteínas de Señalización Intracelular/genética , Masculino , Ratones , Persona de Mediana Edad , Datos de Secuencia Molecular , Degeneración Nerviosa/etiología , Degeneración Nerviosa/patología , Neuronas/citología , Neuronas/metabolismo , Enfermedad de Parkinson/metabolismo , Fragmentos de Péptidos/química , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/metabolismo , Especificidad por Sustrato
6.
J Biol Chem ; 288(51): 36717-32, 2013 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-24235151

RESUMEN

Calpains are a family of calcium-dependent cysteine proteases that are ubiquitously expressed in mammals and play critical roles in neuronal death by catalyzing substrate proteolysis. Here, we developed two-dimensional gel electrophoresis-based protease proteomics to identify putative calpain substrates. To accomplish this, cellular lysates from neuronal cells were first separated by pI, and the immobilized sample on a gel strip was incubated with a recombinant calpain and separated by molecular weight. Among 25 altered protein spots that were differentially expressed by at least 2-fold, we confirmed that arsenical pump-driving ATPase, optineurin, and peripherin were cleaved by calpain using in vitro and in vivo cleavage assays. Furthermore, we found that all of these substrates were cleaved in MN9D cells treated with either ionomycin or 1-methyl-4-phenylpyridinium, both of which cause a calcium-mediated calpain activation. Their cleavage was blocked by calcium chelator or calpain inhibitors. In addition, calpain-mediated cleavage of these substrates and its inhibition by calpeptin were confirmed in a middle cerebral artery occlusion model of cerebral ischemia, as well as a stereotaxic brain injection model of Parkinson disease. Transient overexpression of each protein was shown to attenuate 1-methyl-4-phenylpyridinium-induced cell death, indicating that these substrates may confer protection of varying magnitudes against dopaminergic injury. Taken together, the data indicate that our protease proteomic method has the potential to be applicable for identifying proteolytic substrates affected by diverse proteases. Moreover, the results described here will help us decipher the molecular mechanisms underlying the progression of neurodegenerative disorders where protease activation is critically involved.


Asunto(s)
Calpaína/metabolismo , Neuronas Dopaminérgicas/metabolismo , Proteoma/metabolismo , 1-Metil-4-fenilpiridinio/farmacología , Animales , ATPasas Transportadoras de Arsenitos/genética , ATPasas Transportadoras de Arsenitos/metabolismo , Calpaína/antagonistas & inhibidores , Muerte Celular , Línea Celular , Dipéptidos/farmacología , Dipéptidos/uso terapéutico , Neuronas Dopaminérgicas/efectos de los fármacos , Electroforesis en Gel Bidimensional/métodos , Glicina/análogos & derivados , Glicina/farmacología , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/metabolismo , Ionomicina/farmacología , Periferinas/genética , Periferinas/metabolismo , Proteómica/métodos , Ratas , Ratas Sprague-Dawley
7.
Am J Pathol ; 182(3): 928-39, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23414569

RESUMEN

The type 2 cannabinoid receptor (CB2R) was recently shown to mediate neuroprotection in ischemic injury. However, the role of CB2Rs in the central nervous system, especially neuronal and glial CB2Rs in the cortex, remains unclear. We, therefore, investigated anti-ischemic mechanisms of cortical CB2R activation in various ischemic models. In rat cortical neurons/glia mixed cultures, a CB2R agonist, trans-caryophyllene (TC), decreased neuronal injury and mitochondrial depolarization caused by oxygen-glucose deprivation/re-oxygenation (OGD/R); these effects were reversed by the selective CB2R antagonist, AM630, but not by a type 1 cannabinoid receptor antagonist, AM251. Although it lacked free radical scavenging and antioxidant enzyme induction activities, TC reduced OGD/R-evoked mitochondrial dysfunction and intracellular oxidative stress. Western blot analysis demonstrated that TC enhanced phosphorylation of AMP-activated protein kinase (AMPK) and cAMP responsive element-binding protein (CREB), and increased expression of the CREB target gene product, brain-derived neurotrophic factor. However, TC failed to alter the activity of either Akt or extracellular signal-regulated kinase, two major CB2R signaling pathways. Selective AMPK and CREB inhibitors abolished the neuroprotective effects of TC. In rats, post-ischemic treatment with TC decreased cerebral infarct size and edema, and increased phosphorylated CREB and brain-derived neurotrophic factor expression in neurons. All protective effects of TC were reversed by co-administration with AM630. Collectively, these data demonstrate that cortical CB2R activation by TC ameliorates ischemic injury, potentially through modulation of AMPK/CREB signaling, and suggest that cortical CB2Rs might serve as a putative therapeutic target for cerebral ischemia.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Lesiones Encefálicas/enzimología , Lesiones Encefálicas/patología , Isquemia Encefálica/patología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Receptor Cannabinoide CB2/metabolismo , Transducción de Señal , Proteínas Quinasas Activadas por AMP/antagonistas & inhibidores , Animales , Lesiones Encefálicas/tratamiento farmacológico , Isquemia Encefálica/tratamiento farmacológico , Isquemia Encefálica/enzimología , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Catalasa/metabolismo , Muerte Celular/efectos de los fármacos , Corteza Cerebral/patología , Infarto Cerebral/enzimología , Infarto Cerebral/patología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/antagonistas & inhibidores , Depuradores de Radicales Libres/metabolismo , Glucosa/deficiencia , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Oxígeno/farmacología , Fosforilación/efectos de los fármacos , Sesquiterpenos Policíclicos , Ratas , Ratas Sprague-Dawley , Receptor Cannabinoide CB2/agonistas , Sesquiterpenos/farmacología , Sesquiterpenos/uso terapéutico , Transducción de Señal/efectos de los fármacos , Superóxido Dismutasa/metabolismo
8.
Biochem Biophys Res Commun ; 431(3): 484-9, 2013 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-23333396

RESUMEN

Excessive generation of free radicals is regarded as a major detrimental factor in cerebral ischemic insults. Neurons are particularly vulnerable to oxidative stress due to their limited anti-oxidant capacity. As an important source of antioxidants in the brain, astroglia are now thought to be attractive targets for pharmacological interventions to reduce neuronal oxidative stress in ischemic stroke. In the present study, we synthesized a novel antioxidant, the (1S)-(-)-verbenone derivative LMT-335, and investigated its anti-ischemic activities. In rat cortical neuronal/glial co-cultures, LMT-335 significantly reduced oxygen-glucose deprivation (OGD)/reoxygenation (R)-induced neuronal injury. Although it did not inhibit N-methyl-d-aspartate-induced excitotoxicity, LMT-335 significantly reduced OGD/R-evoked intracellular oxidative stress. However, the oxygen radical absorbance capacity assay and 1,1-diphenyl-2-picrylhydrazyl assay showed that the free radical scavenging activities of LMT-335 were lower than those of trolox. Instead, LMT-335 significantly increased the astroglial expression of heme oxygenase-1 (HO-1), a well-known anti-oxidant stress protein, as evidenced by immunocytochemistry and immunoblot analyses. Moreover, a selective HO-1 inhibitor, tin protoporphyrin IX (SnPP), significantly blocked the anti-ischemic effect of LMT-335. The present findings indicate that LMT-335 exerts neuroprotective effects against OGD/R by up-regulation of HO-1 in astroglial cells. Our data suggest that astroglial HO-1 represents a potential therapeutic target for the treatment of ischemic stroke.


Asunto(s)
Astrocitos/enzimología , Compuestos de Bencilideno/farmacología , Corteza Cerebral/efectos de los fármacos , Ciclohexanonas/farmacología , Glucosa/deficiencia , Hemo-Oxigenasa 1/biosíntesis , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Oxígeno/metabolismo , Terpenos/farmacología , Animales , Compuestos de Bencilideno/química , Monoterpenos Bicíclicos , Células Cultivadas , Corteza Cerebral/enzimología , Corteza Cerebral/patología , Ciclohexanonas/química , Neuronas/patología , Ratas , Ratas Sprague-Dawley , Terpenos/química , Regulación hacia Arriba
9.
Bioorg Med Chem Lett ; 23(19): 5421-5, 2013 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-23953190

RESUMEN

A series of novel (1S)-(-)-verbenone derivatives was synthesized bearing a 4-styryl scaffold. The synthesized compounds were tested for their anti-oxidant, anti-excitotoxic, and anti-ischemic activities. These derivatives significantly reduced oxygen-glucose deprivation-induced neuronal injury and N-methyl-D-aspartic acid-evoked excitotoxicity in cortical neurons. Furthermore, compound 3f was identified as a potent anti-ischemic agent in an in vitro ischemic model, potentially due to the inhibition of N-methyl-D-aspartic acid-evoked excitotoxicity and oxidative/nitrosative stress.


Asunto(s)
Antioxidantes , Descubrimiento de Drogas , Neuronas/efectos de los fármacos , Terpenos/química , Animales , Antioxidantes/síntesis química , Antioxidantes/química , Antioxidantes/farmacología , Monoterpenos Bicíclicos , Células Cultivadas , Modelos Animales de Enfermedad , Isquemia/tratamiento farmacológico , N-Metilaspartato/química , Fármacos Neuroprotectores/síntesis química , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/farmacología , Estrés Oxidativo/efectos de los fármacos , Terpenos/síntesis química , Terpenos/farmacología
10.
J Immunol ; 187(3): 1314-21, 2011 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-21709153

RESUMEN

In intracerebral hemorrhage, microglia become rapidly activated and remove the deposited blood and cellular debris. To survive in a harmful hemorrhagic or posthemorrhagic condition, activated microglia must be equipped with appropriate self-defensive mechanism(s) to resist the toxicity of hemin, a component released from damaged RBCs. In the current study, we found that activation of microglia by pretreatment with LPS markedly reduced their vulnerability to hemin toxicity in vitro. Similarly, intracorpus callosum microinjection of LPS prior to hemin treatment reduced the brain tissue damage caused by hemin and increased microglial density in the penumbra in rats. LPS induced the expressions of inducible NO synthase (iNOS) and heme oxygenase (HO)-1, the rate-limiting enzyme in heme degradation in microglia. The preventive effect by LPS was significantly diminished by an iNOS inhibitor, L-N(6)-(1-iminoethyl)lysine, whereas it was mimicked by a NO donor, diethylamine-NONOate, both suggesting the crucial role of NO in the modulation of hemin-induced toxicity in activated microglia. We further found that NO reduced hemin toxicity via inhibition of hemin-induced activation of JNK and p38 MAPK pathways in microglia. Whereas HO-1 expression in LPS-stimulated microglia was markedly blocked by L-N(6)-(1-iminoethyl)lysine, the HO-1 inhibitor, tin protoporphyrin, increased iNOS expression and decreased the susceptibility of LPS-activated microglia to hemin toxicity. The data indicate that the mutual interaction between NO and HO-1 plays a critical role in modulating the adaptive response of activated microglia to hemin toxicity. Better understanding of the survival mechanism of activated microglia may provide a therapeutic strategy to attenuate the devastating intracerebral hemorrhagic injury.


Asunto(s)
Hemina/toxicidad , Proteínas Quinasas JNK Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Microglía/efectos de los fármacos , Microglía/enzimología , Óxido Nítrico/fisiología , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Astrocitos/efectos de los fármacos , Astrocitos/enzimología , Astrocitos/patología , Células Cultivadas , Proteínas Quinasas JNK Activadas por Mitógenos/fisiología , Lipopolisacáridos/administración & dosificación , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/inmunología , Masculino , Microglía/patología , Microinyecciones , Neuronas/efectos de los fármacos , Neuronas/enzimología , Neuronas/patología , Óxido Nítrico/biosíntesis , Ratas , Ratas Sprague-Dawley , Proteínas Quinasas p38 Activadas por Mitógenos/fisiología
11.
Trials ; 24(1): 635, 2023 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-37794489

RESUMEN

BACKGROUND: Repeated COVID-19 waves and corresponding mitigation measures have impacted health systems globally with exceptional challenges. In response to the pandemic, researchers, regulators, and funders rapidly pivoted to COVID-19 research activities. However, many clinical drug studies were not completed, due to often complex and rapidly evolving research conditions. METHODS: We outline our experience of planning and managing a randomised, adaptive, open-label, phase 2 clinical trial to evaluate the safety and efficacy of four repurposed drug regimens versus standard-of-care (SOC) in outpatients with 'mild to moderate' COVID-19 in Johannesburg, South Africa, in the context of a partnership with multiple stakeholders. The study was conducted between 3 September 2020 and 23 August 2021 during changing COVID-19 restrictions, significant morbidity and mortality waves, and allied supply line, economic, and political instability. RESULTS: Our clinical study design was pragmatic, including low-risk patients who were treated open label. There was built-in flexibility, including provision for some sample size adjustment and a range of secondary efficacy outcomes. Barriers to recruitment included the timing of waves, staff shortages due to illness, late presentation of patients, COVID-19 misinformation, and political unrest. Mitigations were the use of community health workers, deployment of mobile clinical units, and simplification of screening. Trial management required a radical reorganisation of logistics and processes to accommodate COVID-19 restrictions. These included the delivery of staff training and monitoring remotely, electronic consent, patient training and support to collect samples and report data at home, and the introduction of tele-medicine. These measures were successful for data collection, safe, and well received by patients. CONCLUSION: Completing a COVID-19 trial in outpatients during the height of the pandemic required multiple innovations in nearly every aspect of clinical trial management, a high commitment level from study staff and patients, and support from study sponsors. Our experience has generated a more robust clinical research infrastructure, building in efficiencies to clinical trial management beyond the pandemic.


Asunto(s)
COVID-19 , Humanos , SARS-CoV-2 , Pacientes Ambulatorios , Sudáfrica/epidemiología , Proyectos de Investigación , Resultado del Tratamiento
12.
Diagnostics (Basel) ; 14(1)2023 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-38201379

RESUMEN

We propose a self-supervised machine learning (ML) algorithm for sequence-type classification of brain MRI using a supervisory signal from DICOM metadata (i.e., a rule-based virtual label). A total of 1787 brain MRI datasets were constructed, including 1531 from hospitals and 256 from multi-center trial datasets. The ground truth (GT) was generated by two experienced image analysts and checked by a radiologist. An ML framework called ImageSort-net was developed using various features related to MRI acquisition parameters and used for training virtual labels and ML algorithms derived from rule-based labeling systems that act as labels for supervised learning. For the performance evaluation of ImageSort-net (MLvirtual), we compare and analyze the performances of models trained with human expert labels (MLhumans), using as a test set blank data that the rule-based labeling system failed to infer from each dataset. The performance of ImageSort-net (MLvirtual) was comparable to that of MLhuman (98.5% and 99%, respectively) in terms of overall accuracy when trained with hospital datasets. When trained with a relatively small multi-center trial dataset, the overall accuracy was relatively lower than that of MLhuman (95.6% and 99.4%, respectively). After integrating the two datasets and re-training them, MLvirtual showed higher accuracy than MLvirtual trained only on multi-center datasets (95.6% and 99.7%, respectively). Additionally, the multi-center dataset inference performances after the re-training of MLvirtual and MLhumans were identical (99.7%). Training of ML algorithms based on rule-based virtual labels achieved high accuracy for sequence-type classification of brain MRI and enabled us to build a sustainable self-learning system.

13.
Am J Pathol ; 179(4): 2042-52, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21854743

RESUMEN

A3 adenosine receptor (A3AR) is recognized as a novel therapeutic target for ischemic injury; however, the mechanism underlying anti-ischemic protection by the A3AR agonist remains unclear. Here, we report that 2-chloro-N(6)-(3-iodobenzyl)-5'-N-methylcarbamoyl-4'-thioadenosine (LJ529), a selective A3AR agonist, reduces inflammatory responses that may contribute to ischemic cerebral injury. Postischemic treatment with LJ529 markedly reduced cerebral ischemic injury caused by 1.5-hour middle cerebral artery occlusion, followed by 24-hour reperfusion in rats. This effect was abolished by the simultaneous administration of the A3AR antagonist MRS1523, but not the A2AAR antagonist SCH58261. LJ529 prevented the infiltration/migration of microglia and monocytes occurring after middle cerebral artery occlusion and reperfusion, and also after injection of lipopolysaccharides into the corpus callosum. The reduced migration of microglia by LJ529 could be related with direct inhibition of chemotaxis and down-regulation of spatiotemporal expression of Rho GTPases (including Rac, Cdc42, and Rho), rather than by biologically relevant inhibition of inflammatory cytokine/chemokine release (eg, IL-1ß, TNF-α, and MCP-1) or by direct inhibition of excitotoxicity/oxidative stress (not affected by LJ529). The present findings indicate that postischemic activation of A3AR and the resultant reduction of inflammatory response should provide a promising therapeutic strategy for the treatment of ischemic stroke.


Asunto(s)
Agonistas del Receptor de Adenosina A3/farmacología , Lesiones Encefálicas/complicaciones , Lesiones Encefálicas/prevención & control , Isquemia Encefálica/patología , Isquemia Encefálica/prevención & control , Movimiento Celular/efectos de los fármacos , Inflamación/patología , Adenosina/análogos & derivados , Adenosina/farmacología , Animales , Infarto Encefálico/complicaciones , Infarto Encefálico/patología , Lesiones Encefálicas/patología , Isquemia Encefálica/complicaciones , Quimiocina CCL2/metabolismo , Glucosa/deficiencia , Inflamación/complicaciones , Interleucina-1beta/metabolismo , Lipopolisacáridos/farmacología , Masculino , Microglía/efectos de los fármacos , Microglía/enzimología , Microglía/metabolismo , Microglía/patología , Monocitos/efectos de los fármacos , Monocitos/patología , N-Metilaspartato/toxicidad , Transporte de Proteínas/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Tionucleósidos/farmacología , Factor de Necrosis Tumoral alfa/metabolismo , Proteínas de Unión al GTP rho/metabolismo
14.
EBioMedicine ; 86: 104322, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36332361

RESUMEN

BACKGROUND: This exploratory study investigated four repurposed anti-infective drug regimens in outpatients with COVID-19. METHODS: This phase 2, single centre, randomised, open-label, clinical trial was conducted in South Africa between 3rd September 2020 and 23rd August 2021. Symptomatic outpatients aged 18-65 years, with RT-PCR confirmed SARS-CoV-2 infection were computer randomised (1:1:1:1:1) to standard-of-care (SOC) with paracetamol, or SOC plus artesunate-amodiaquine (ASAQ), pyronaridine-artesunate (PA), favipiravir plus nitazoxanide (FPV + NTZ), or sofosbuvir-daclatasvir (SOF-DCV). The primary endpoint was the incidence of viral clearance, i.e., the proportion of patients with a negative SARS-CoV-2 RT-PCR on day 7, compared to SOC using a log-binomial model in the modified intention-to-treat (mITT) population. FINDINGS: The mITT population included 186 patients: mean age (SD) 34.9 (10.3) years, body weight 78.2 (17.1) kg. Day 7 SARS-CoV-2 clearance rates (n/N; risk ratio [95% CI]) were: SOC 34.2% (13/38), ASAQ 38.5% (15/39; 0.80 [0.44, 1.47]), PA 30.3% (10/33; 0.69 [0.37, 1.29]), FPV + NTZ 27.0% (10/37; 0.60 [0.31, 1.18]) and SOF-DCV 23.5% (8/34; 0.47 [0.22, 1.00]). Three lower respiratory tract infections occurred (PA 6.1% [2/33]; SOF-DCV 2.9% [1/34]); two required hospitalisation (PA, SOF-DCV). There were no deaths. Adverse events occurred in 55.3% (105/190) of patients, including one serious adverse event (pancytopenia; FPV + NTZ). INTERPRETATION: There was no statistical difference in viral clearance for any regimen compared to SOC. All treatments were well tolerated. FUNDING: Medicines for Malaria Venture, with funding from the UK Foreign, Commonwealth and Development Office, within the Covid-19 Therapeutics Accelerator in partnership with Wellcome, the Bill and Melinda Gates Foundation, and Mastercard.


Asunto(s)
COVID-19 , Humanos , Adulto , SARS-CoV-2 , Pacientes Ambulatorios , Tiazoles , Resultado del Tratamiento
15.
J Ginseng Res ; 44(4): 619-626, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32617042

RESUMEN

BACKGROUND: The effects of diol-ginsenoside fraction (Diol-GF) and triol-ginsenoside fraction (Triol-GF) from Korean Red Ginseng on the development of type 1 diabetes (T1D) were examined in diabetes-prone biobreeding (DP-BB) rats that spontaneously develop T1D through an autoimmune process. METHODS: DP-BB female rats were treated with Diol-GF or Triol-GF daily from the age of 3-4 weeks up to 11-12 weeks (1 mg/g body weight). RESULTS: Diol-GF delayed the onset, and reduced the incidence, of T1D. Islets of Diol-GF-treated DP-BB rats showed significantly lower insulitis and preserved higher plasma and pancreatic insulin levels. Diol-GF failed to change the proportion of lymphocyte subsets such as T cells, natural killer cells, and macrophages in the spleen and blood. Diol-GF had no effect on the ability of DP-BB rat splenocytes to induce diabetes in recipients. Diol-GF and diol-ginsenoside Rb1 significantly decreased tumor necrosis factor α production, whereas diol-ginsenosides Rb1 and Rd decreased interleukin 1ß production in RAW264.7 cells. Furthermore, mixed cytokine- and chemical-induced ß-cell cytotoxicity was greatly inhibited by Diol-GF and diol-ginsenosides Rc and Rd in RIN5mF cells. However, nitric oxide production in RAW264.7 cells was unaffected by diol-ginsenosides. CONCLUSION: Diol-GF, but not Triol-GF, significantly delayed the development of insulitis and T1D in DP-BB rats. The antidiabetogenic action of Diol-GF may result from the decrease in cytokine production and increase in ß-cell resistance to cytokine/free radical-induced cytotoxicity.

16.
Artículo en Inglés | WPRIM | ID: wpr-1043253

RESUMEN

Background@#and Purpose The onset of Huntington’s disease (HD) usually occurs before the age of 50 years, and the median survival time from onset is 15 years. We investigated survival in patients with late-onset HD (LoHD) (age at onset ≥60 years) and the associations of the number of mutant CAG repeats and age at onset (AAO) with survival in patients with HD. @*Methods@#Patients with genetically confirmed HD at six referral centers in South Korea between 2000 and 2020 were analyzed retrospectively. Baseline demographic, clinical, and genetic characteristics and the survival status as at December 2020 were collected. @*Results@#Eighty-seven patients were included, comprising 26 with LoHD (AAO=68.77±5.91 years, mean±standard deviation; 40.54±1.53 mutant CAG repeats) and 61 with common-onset HD (CoHD) (AAO=44.12±8.61 years, 44.72±4.27 mutant CAG repeats). The ages at death were 77.78±7.46 and 53.72±10.86 years in patients with LoHD and CoHD, respectively (p< 0.001). The estimated survival time was 15.21±2.49 years for all HD patients, and 10.74±1.95 and 16.15±2.82 years in patients with LoHD and CoHD, respectively. More mutant CAG repeats and higher AAO were associated with shorter survival (hazard ratio [HR]=1.05, 95% confidence interval [CI]=1.01–1.09, p=0.019; and HR=1.17, 95% CI=1.03–1.31, p=0.013; respectively) for all HD patients. The LoHD group showed no significant factors associated with survival after disease onset, whereas the number of mutant CAG repeats had a significant effect (HR=1.12, 95% CI=1.01–1.23, pp=0.034) in the CoHD group. @*Conclusions@#Survival after disease onset was shorter in patients with LoHD than in those with CoHD. More mutant CAG repeats and higher AAO were associated with shorter survival in patients with HD.

17.
Artículo en Inglés | WPRIM | ID: wpr-1044878

RESUMEN

Objective@#To evaluate the diagnostic performance of susceptibility map-weighted imaging (SMwI) taken in different acquisition planes for discriminating patients with neurodegenerative parkinsonism from those without. @*Materials and Methods@#This retrospective, observational, single-institution study enrolled consecutive patients who visited movement disorder clinics and underwent brain MRI and 18F-FP-CIT PET between September 2021 and December 2021. SMwI images were acquired in both the oblique (perpendicular to the midbrain) and the anterior commissure-posterior commissure (AC-PC) planes. Hyperintensity in the substantia nigra was determined by two neuroradiologists. 18F-FP-CIT PET was used as the reference standard. Inter-rater agreement was assessed using Cohen’s kappa coefficient. The diagnostic performance of SMwI in the two planes was analyzed separately for the right and left substantia nigra. Multivariable logistic regression analysis with generalized estimating equations was applied to compare the diagnostic performance of the two planes. @*Results@#In total, 194 patients were included, of whom 105 and 103 had positive results on 18F-FP-CIT PET in the left and right substantia nigra, respectively. Good inter-rater agreement in the oblique (κ = 0.772/0.658 for left/right) and AC-PC planes (0.730/0.741 for left/right) was confirmed. The pooled sensitivities for two readers were 86.4% (178/206, left) and 83.3% (175/210, right) in the oblique plane and 87.4% (180/206, left) and 87.6% (184/210, right) in the AC-PC plane. The pooled specificities for two readers were 83.5% (152/182, left) and 82.0% (146/178, right) in the oblique plane, and 83.5% (152/182, left) and 86.0% (153/178, right) in the AC-PC plane. There were no significant differences in the diagnostic performance between the two planes (P > 0.05). @*Conclusion@#There are no significant difference in the diagnostic performance of SMwI performed in the oblique and AC-PC plane in discriminating patients with parkinsonism from those without. This finding affirms that each institution may choose the imaging plane for SMwI according to their clinical settings.

18.
Artículo en Inglés | WPRIM | ID: wpr-1043855

RESUMEN

Objective@#This is the first prospective cohort study of Huntington’s disease (HD) in Korea. This study aimed to investigate the caregiver burden in relation to the characteristics of patients and caregivers. @*Methods@#From August 2020 to February 2022, we enrolled patients with HD from 13 university hospitals in Korea. We used the 12-item Zarit Burden Interview (ZBI-12) to evaluate the caregiver burden. We evaluated the clinical associations of the ZBI-12 scores by linear regression analysis and investigated the differences between the low- and high-burden groups. @*Results@#Sixty-five patients with HD and 45 caregivers were enrolled in this cohort study. The average age at onset of motor symptoms was 49.3 ± 12.3 years, with an average cytosine-adenine-guanine (CAG)n of 42.9 ± 4.0 (38–65). The median ZBI-12 score among our caregivers was 17.6 ± 14.2. A higher caregiver burden was associated with a more severe Shoulson–Fahn stage (p = 0.038) of the patients. A higher ZBI-12 score was also associated with lower independence scale (B = -0.154, p = 0.006) and functional capacity (B = -1.082, p = 0.002) scores of patients. The caregiving duration was longer in the high- than in the low-burden group. Caregivers’ demographics, blood relation, and marital and social status did not affect the burden significantly. @*Conclusion@#HD patients’ neurological status exerts an enormous impact on the caregiver burden regardless of the demographic or social status of the caregiver. This study emphasizes the need to establish an optimal support system for families dealing with HD in Korea. A future longitudinal analysis could help us understand how disease progression aggravates the caregiver burden throughout the entire disease course.

19.
Artículo en Inglés | WPRIM | ID: wpr-1043873

RESUMEN

Objective@#The Scales for Outcomes in Parkinson’s Disease–Cognition (SCOPA-Cog) was developed to assess cognition in patients with Parkinson’s disease (PD). In this study, we aimed to evaluate the validity and reliability of the Korean version of the SCOPACog (K-SCOPA-Cog). @*Methods@#We enrolled 129 PD patients with movement disorders from 31 clinics in South Korea. The original version of the SCOPA-Cog was translated into Korean using the translation-retranslation method. The test–retest method with an intraclass correlation coefficient (ICC) and Cronbach’s alpha coefficient were used to assess reliability. Spearman’s rank correlation analysis with the Montreal Cognitive Assessment-Korean version (MOCA-K) and the Korean Mini-Mental State Examination (K-MMSE) were used to assess concurrent validity. @*Results@#The Cronbach’s alpha coefficient was 0.797, and the ICC was 0.887. Spearman’s rank correlation analysis revealed a significant correlation with the K-MMSE and MOCA-K scores (r = 0.546 and r = 0.683, respectively). @*Conclusion@#Our results demonstrate that the K-SCOPA-Cog has good reliability and validity.

20.
Artículo en Inglés | WPRIM | ID: wpr-1001394

RESUMEN

Glucosylceramidase beta 1 (GBA1) variants have attracted enormous attention as the most promising and important genetic candidates for precision medicine in Parkinson’s disease (PD). A substantial correlation between GBA1 genotypes and PD phenotypes could inform the prediction of disease progression and promote the development of a preventive intervention for individuals at a higher risk of a worse disease prognosis. Moreover, the GBA1-regulated pathway provides new perspectives on the pathogenesis of PD, such as dysregulated sphingolipid metabolism, impaired protein quality control, and disrupted endoplasmic reticulum-Golgi trafficking. These perspectives have led to the development of novel disease-modifying therapies for PD targeting the GBA1-regulated pathway by repositioning treatment strategies for Gaucher’s disease. This review summarizes the current hypotheses on a mechanistic link between GBA1 variants and PD and possible therapeutic options for modulating GBA1-regulated pathways in PD patients.

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