Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
1.
J Infect Dis ; 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37711050

RESUMO

Developing new adjuvants that can effectively induce both humoral and cellular immune responses while broadening the immune response is of great value. In this study, we aimed to develop GM-CSF- or IL-18-expressing single-stranded RNA (ssRNA) adjuvants based on the encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES) and tested their efficacy in combination with ovalbumin (OVA) or inactivated influenza vaccines. Notably, cytokine-expressing RNA adjuvants increased the expression of antigen-presenting cell activation markers. Specifically, GM-CSF-expressing RNA adjuvants increased CD4+T cell responses, while IL-18-expressing RNA adjuvants increased CD8+T cell responses in mice when combined with OVA. In addition, cytokine-expressing RNA adjuvants increased the frequency of polyclonal T cells in combination with the influenza vaccine and reduced the clinical illness scores and weight loss of mice after viral challenge. Collectively, our results suggest that cytokine-expressing RNA adjuvants can be applied to protein-based or inactivated vaccines to increase their efficacy.

2.
Small ; 19(28): e2300526, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37010008

RESUMO

Polymer-based nanocomposites are desirable materials for next-generation dielectric capacitors. 2D dielectric nanosheets have received significant attention as a filler. However, randomly spreading the 2D filler causes residual stresses and agglomerated defect sites in the polymer matrix, which leads to the growth of an electric tree, resulting in a more premature breakdown than expected. Therefore, realizing a well-aligned 2D nanosheet layer with a small amount is a key challenge; it can inhibit the growth of conduction paths without degrading the performance of the material. Here, an ultrathin Sr1.8 Bi0.2 Nb3 O10 (SBNO) nanosheet filler is added as a layer into poly(vinylidene fluoride) (PVDF) films via the Langmuir-Blodgett method. The structural properties, breakdown strength, and energy storage capacity of a PVDF and multilayer PVDF/SBNO/PVDF composites as a function of the thickness-controlled SBNO layer are examined. The seven-layered (only 14 nm) SBNO nanosheets thin film can sufficiently prevent the electrical path in the PVDF/SBNO/PVDF composite and shows a high energy density of 12.8 J cm-3 at 508 MV m-1 , which is significantly higher than that of the bare PVDF film (9.2 J cm-3 at 439 MV m-1 ). At present, this composite has the highest energy density among the polymer-based nanocomposites under the filler of thin thickness.

3.
J Med Virol ; 95(12): e29309, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38100632

RESUMO

The E6 and E7 proteins of specific subtypes of human papillomavirus (HPV), including HPV 16 and 18, are highly associated with cervical cancer as they modulate cell cycle regulation. The aim of this study was to investigate the potential antitumor effects of a messenger RNA-HPV therapeutic vaccine (mHTV) containing nononcogenic E6 and E7 proteins. To achieve this, C57BL/6j mice were injected with the vaccine via both intramuscular and subcutaneous routes, and the resulting effects were evaluated. mHTV immunization markedly induced robust T cell-mediated immune responses and significantly suppressed tumor growth in both subcutaneous and orthotopic tumor-implanted mouse model, with a significant infiltration of immune cells into tumor tissues. Tumor retransplantation at day 62 postprimary vaccination completely halted progression in all mHTV-treated mice. Furthermore, tumor expansion was significantly reduced upon TC-1 transplantation 160 days after the last immunization. Immunization of rhesus monkeys with mHTV elicited promising immune responses. The immunogenicity of mHTV in nonhuman primates provides strong evidence for clinical application against HPV-related cancers in humans. All data suggest that mHTV can be used as both a therapeutic and prophylactic vaccine.


Assuntos
Proteínas Oncogênicas Virais , Infecções por Papillomavirus , Vacinas contra Papillomavirus , Neoplasias do Colo do Útero , Humanos , Feminino , Animais , Camundongos , Papillomavirus Humano , Proteínas Oncogênicas Virais/genética , Infecções por Papillomavirus/prevenção & controle , RNA Mensageiro/genética , Proteínas E7 de Papillomavirus/genética , Camundongos Endogâmicos C57BL , Vacinação/métodos , Imunização , Neoplasias do Colo do Útero/prevenção & controle
4.
Diabetes Obes Metab ; 24(9): 1800-1809, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35581902

RESUMO

AIMS: To compare the efficacy and safety of adding low-dose lobeglitazone (0.25 mg/day) or standard-dose lobeglitazone (0.5 mg/day) to patients with type 2 diabetes mellitus (T2DM) with inadequate glucose control on metformin and dipeptidyl peptidase (DPP4) inhibitor therapy. MATERIALS AND METHODS: In this phase 4, multicentre, double-blind, randomized controlled, non-inferiority trial, patients with T2DM insufficiently controlled by metformin and DPP4 inhibitor combination therapy were randomized to receive either low-dose or standard-dose lobeglitazone. The primary endpoint was non-inferiority of low-dose lobeglitazone in terms of glycaemic control, expressed as the difference in mean glycated haemoglobin levels at week 24 relative to baseline values and compared with standard-dose lobeglitazone, using 0.5% non-inferiority margin. RESULTS: At week 24, the mean glycated haemoglobin levels were 6.87 ± 0.54% and 6.68 ± 0.46% in low-dose and standard-dose lobeglitazone groups, respectively (p = .031). The between-group difference was 0.18% (95% confidence interval 0.017-0.345), showing non-inferiority of the low-dose lobeglitazone. Mean body weight changes were significantly greater in the standard-dose group (1.36 ± 2.23 kg) than in the low-dose group (0.50 ± 1.85 kg) at week 24. The changes in HOMA-IR, lipid profile and liver enzyme levels showed no significant difference between the groups. Overall treatment-emergent adverse events (including weight gain, oedema and hypoglycaemia) occurred more frequently in the standard-dose group. CONCLUSIONS: Adding low-dose lobeglitazone to metformin and DPP4 inhibitor combination resulted in a non-inferior glucose-lowering outcome and fewer adverse events compared with standard-dose lobeglitazone. Therefore, low-dose lobeglitazone might be one option for individualized strategy in patients with T2DM.


Assuntos
Diabetes Mellitus Tipo 2 , Inibidores da Dipeptidil Peptidase IV , Metformina , Glicemia , Diabetes Mellitus Tipo 2/induzido quimicamente , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/efeitos adversos , Dipeptidil Peptidases e Tripeptidil Peptidases/uso terapêutico , Método Duplo-Cego , Quimioterapia Combinada , Glucose/uso terapêutico , Hemoglobinas Glicadas , Humanos , Hipoglicemiantes/efeitos adversos , Metformina/uso terapêutico , Inibidores de Proteases/uso terapêutico , Pirimidinas , Tiazolidinedionas , Resultado do Tratamento
5.
Analyst ; 143(8): 1780-1785, 2018 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-29379912

RESUMO

The development of artificial peroxidases has attracted great interest because of their applications in various fields such as the chemical industry and biosensing. In this study, 2,6-bis[(bis(2-pyridylmethyl)amino)-methyl]-4-methylphenol (H-bpmp) complexes with various transition metal ions have been investigated as artificial peroxidases. Among these metal complexes, the [Mn2(bpmp)]3+ complex showed the highest peroxidase-like activity as determined by a colorimetric assay using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and H2O2. The peroxidase-like activity was inhibited by pyrophosphate (PPi), which blocked the active site of the [Mn2(bpmp)]3+ complex. Based on this phenomenon, the ABTS/H2O2/[Mn2(bpmp)]3+ system could be applied for the detection of PPi, which could be achieved selectively by visual observation with a detection limit of 130 nM. Moreover, the addition of pyrophosphatase (PPase) to the [Mn2(bpmp)]3+ complex blocked by PPi resulted in the recovery of the peroxidase-like activity of the [Mn2(bpmp)]3+ complex due to the hydrolysis of PPi. Hence, the enzyme cascade reaction of the PPase and [Mn2(bpmp)]3+ complex allowed the real-time colorimetric assay of PPase.

6.
Endocr Res ; 43(1): 47-54, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29028177

RESUMO

PURPOSE: Metabolic syndrome increases the risk of cardiovascular disease. Recently glucagon-like peptide 1 (GLP-1) agonists proved to be effective in preventing cardiovascular disease (CVD) in patients with type 2 diabetes. We investigated the association of blood incretin levels with metabolic syndrome in patients with type 2 diabetes. MATERIALS AND METHODS: This is a cross-sectional study involving 334 people with type 2 diabetes. Intact GLP-1 (iGLP-1) and intact glucose-dependent insulinotropic polypeptide (iGIP) levels were measured in a fasted state and 30 min after ingestion of a standard mixed meal. Metabolic syndrome was diagnosed based on the criteria of the International Diabetes Federation. RESULTS: Two hundred twenty-five (69%) of the subjects have metabolic syndrome. The fasting iGLP-1 level was no different between groups. Thirty-min postprandial iGLP-1 was non-significantly lower in the subjects who had metabolic syndrome. Incremental iGLP-1 (ΔiGLP-1, the difference between 30-min postmeal and fasting iGLP-1 levels) was significantly lower in those with metabolic syndrome. There were no significant differences in fasting iGIP, postprandial iGIP, and ΔiGIP between groups. The ΔiGLP-1, but not ΔiGIP levels decreased significantly as the number of metabolic syndrome components increased. In hierarchical logistic regression analysis, the ΔiGLP-1 level was found to be a significant contributor to metabolic syndrome even after adjusting for other covariates. CONCLUSION: Taken together, the iGLP-1 increment in the 30 min after meal ingestion is inversely associated with metabolic syndrome in patients with type 2 diabetes. This suggests that postmeal iGLP-1 increment could be useful in assessing cardiovascular risk in type 2 diabetes.


Assuntos
Doenças Cardiovasculares/sangue , Diabetes Mellitus Tipo 2/sangue , Polipeptídeo Inibidor Gástrico/sangue , Peptídeo 1 Semelhante ao Glucagon/sangue , Incretinas/sangue , Síndrome Metabólica/sangue , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Prandial , Risco
7.
Am J Infect Control ; 52(2): 214-219, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37406965

RESUMO

BACKGROUND: This study analyzed the validity of healthcare-associated infection (HAI) data of the Korean National healthcare-associated Infections Surveillance System. METHODS: The validation process consisted of external (EV) and internal (IV) validation phases. Of the 193 hospitals that participated from July 2016 through June 2017, EV was performed for 10 hospitals that were selected based on the HAI rate percentile. The EV team reviewed 295 medical records for 60 HAIs and 235 non-HAI control patients. IV was performed for both the 10 EV hospitals and 11 other participating hospitals that did not report any HAIs. RESULTS: In the EV, the diagnosis of urinary tract infections had a sensitivity of 72.0% and a specificity of 99.3%. The respective sensitivities of bloodstream infection and pneumonia were 63.2% and 70.6%; the respective specificities were 98.8% and 99.6%. The agreement (ĸ) between the EV and IV for 10 hospitals was 0.754 for urinary tract infections and 0.674 for bloodstream infections (P < .001, respectively). Additionally, IV found additional cases among 11 zero-report hospitals. DISCUSSION: This study demonstrates the need for ongoing validation and continuous training to maintain the accuracy of nationwide surveillance data. CONCLUSIONS: IV should be considered a validation method to supplement EV.


Assuntos
Infecções Relacionadas a Cateter , Doenças Transmissíveis , Infecção Hospitalar , Sepse , Infecções Urinárias , Humanos , Infecção Hospitalar/epidemiologia , Infecções Urinárias/epidemiologia , Sepse/epidemiologia , República da Coreia/epidemiologia , Atenção à Saúde , Infecções Relacionadas a Cateter/epidemiologia
8.
Bioact Mater ; 38: 486-498, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38779592

RESUMO

The rapid development of messenger RNA (mRNA) vaccines formulated with lipid nanoparticles (LNPs) has contributed to control of the COVID-19 pandemic. However, mRNA vaccines have raised concerns about their potential toxicity and clinical safety, including side effects, such as myocarditis, anaphylaxis, and pericarditis. In this study, we investigated the potential of trehalose glycolipids-containing LNP (LNP S050L) to reduce the risks associated with ionizable lipids. Trehalose glycolipids can form hydrogen bonds with polar biomolecules, allowing the formation of a stable LNP structure by replacing half of the ionizable lipids. The efficacy and safety of LNP S050L were evaluated by encapsulating the mRNA encoding the luciferase reporter gene and measuring gene expression and organ toxicity, respectively. Furthermore, mice immunized with an LNP S050L-formulated mRNA vaccine expressing influenza hemagglutinin exhibited a significant reduction in organ toxicity, including in the heart, spleen, and liver, while sustaining gene expression and immune efficiency, compared to conventional LNPs (Con-LNPs). Our findings suggest that LNP S050L, a trehalose glycolipid-based LNP, could facilitate the development of safe mRNA vaccines with improved clinical safety.

9.
J Clin Med ; 12(18)2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37762748

RESUMO

There is a growing interest in the role of glucagon in type 2 diabetes mellitus (T2DM). Glucagon and insulin regulate glucose and lipid metabolism. Metabolic syndrome is an important risk factor for cardiovascular disease in patients with T2DM. We investigated the association between glucagon to insulin ratio and metabolic syndrome in patients with T2DM. This is a cross-sectional study involving 317 people with type 2 diabetes. Glucagon and insulin levels were measured in a fasted state and 30 min after ingesting a standard mixed meal. The Criteria of the International Diabetes Federation defined metabolic syndrome. Two hundred nineteen (69%) of the subjects had metabolic syndrome. The fasting glucagon to insulin ratio was significantly lower in patients with metabolic syndrome (14.0 ± 9.7 vs. 17.3 ± 10.3, p < 0.05). The fasting glucagon to insulin ratio was significantly lowered as the number of metabolic syndrome components increased. In hierarchical logistic regression analysis, the fasting glucagon to insulin ratio significantly contributed to metabolic syndrome even after adjusting for other covariates. The fasting glucagon to insulin ratio is inversely associated with metabolic syndrome in patients with type 2 diabetes. This suggests that glucagon-targeted therapeutics may reduce cardiovascular risk by improving metabolic syndrome.

10.
Free Radic Biol Med ; 208: 384-393, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37659699

RESUMO

Ferroptosis is a novel form of cell death triggered by iron-dependent lipid peroxidation. Recent findings suggest that inhibiting system χc-induces ferroptosis by reducing intracellular cystine levels, and that ferroptosis in renal tubular epithelial cells (RTECs) contributes to acute kidney injury (AKI) and diabetic nephropathy. Moreover, 2-deoxy-d-ribose (dRib) has been shown to inhibit cystine uptake through xCT, the functional unit of system χc-, in ß-cells. This study aimed to investigate if dRib induces ferroptosis in RTECs and identify the underlying mechanisms. dRib treatment reduced cystine uptake and glutathione (GSH) content, and increased intracellular levels of malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), lipid reactive oxygen species (ROS), and cell death in both NRK-52E cells and primary cultured RTECs. However, treatment with inhibitors of ferroptosis, such as deferoxamine (DFO), ferrostatin-1 (Fer-1), and liproxstatin-1 (Lip-1), counteracted the effects of dRib on GSH, MDA, 4-HNE, and lipid ROS levels, as well as cell death. Additionally, 2-mercaptoethanol (2-ME) treatment or xCT gene overexpression protected against dRib-induced changes. Moreover, transmission electron microscopy revealed dRib-induced mitochondrial shrinkage, decrease in cristae number, and outer membrane rupture. Furthermore, dRib treatment upregulated the expression of genes associated with ferroptosis, and downregulated xCT protein expression. The decrease in xCT protein caused by dRib was consistently observed even when treated with the protein synthesis inhibitor cycloheximide. However, treatment with the proteasome inhibitor MG132 reversed the dRib-induced decrease in xCT protein expression. Additionally, dRib increased xCT protein ubiquitination. Overall, dRib induces ferroptosis in RTECs by degrading xCT protein through ubiquitin-proteasome system (UPS), resulting in reduced intracellular cystine uptake. Therefore, targeting the regulation of system χc-through UPS could be a potential therapeutic approach for AKI and diabetic nephropathy.


Assuntos
Injúria Renal Aguda , Nefropatias Diabéticas , Ferroptose , Humanos , Espécies Reativas de Oxigênio/metabolismo , Estresse Oxidativo , Ribose/farmacologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Apoptose , Cistina/metabolismo , Proteólise , Glutationa/metabolismo , Células Epiteliais/metabolismo , Ubiquitinas/metabolismo , Lipídeos
11.
NPJ Vaccines ; 8(1): 84, 2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37271785

RESUMO

In response to the COVID-19 pandemic, different types of vaccines, such as inactive, live-attenuated, messenger RNA (mRNA), and protein subunit, have been developed against SARS-CoV-2. This has unintentionally created a unique scenario where heterologous prime-boost vaccination against a single virus has been administered to a large human population. Here, we aimed to analyze whether the immunization order of vaccine types influences the efficacy of heterologous prime-boost vaccination, especially mRNA and protein-based vaccines. We developed a new mRNA vaccine encoding the hemagglutinin (HA) glycoprotein of the influenza virus using the 3'-UTR and 5'-UTR of muscle cells (mRNA-HA) and tested its efficacy by heterologous immunization with an HA protein vaccine (protein-HA). The results demonstrated higher IgG2a levels and hemagglutination inhibition titers in the mRNA-HA priming/protein-HA boosting (R-P) regimen than those induced by reverse immunization (protein-HA priming/mRNA-HA boosting, P-R). After the viral challenge, the R-P group showed lower virus loads and less inflammation in the lungs than the P-R group did. Transcriptome analysis revealed that the heterologous prime-boost groups had differentially activated immune response pathways, according to the order of immunization. In summary, our results demonstrate that the sequence of vaccination is critical to direct desired immune responses. This study demonstrates the potential of a heterologous vaccination strategy using mRNA and protein vaccine platforms against viral infection.

12.
RSC Adv ; 12(14): 8668-8673, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35424784

RESUMO

Numerous assays based on peroxidase activity have been developed for the detection of analytes due to the various optical peroxidase substrates. However, most substrates are sensitive to light and pH and are over-oxidized in the presence of excess H2O2. In this study, 2-((6-methoxynaphthalen-2-yl)methylene)-1,1-dimethylhydrazine (MNDH), a fluorescent peroxidase substrate prepared from naphthalene-based aldehyde N,N-dimethylhydrazone, was developed. MNDH showed quantitative fluorescence changes with respect to the H2O2 concentration in the presence of horseradish peroxidase (HRP), and the MNDH/HRP assay showed no changes in fluorescence caused by over-oxidation in the presence of excess H2O2. Further, MNDH was thermo- and photostable. Additionally, the assay could be operated over a considerably wide pH range, from acidic to neutral. Moreover, MNDH can be used to detect glucose quantitatively in human serum samples by using an enzyme cascade assay system.

13.
J Clin Med ; 10(11)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34199839

RESUMO

BACKGROUND: We aimed to investigate the changes in glucagon levels in people with diabetes after the ingestion of a mixed meal and the correlations of variation in glucagon levels with incretin and clinico-biochemical characteristics. METHODS: Glucose, C-peptide, glucagon, intact glucagon-like peptide 1 (iGLP-1), and intact glucose-dependent insulinotropic polypeptide (iGIP) were measured in blood samples collected from 317 people with diabetes before and 30 min after the ingestion of a standard mixed meal. The delta (Δ) is the 30-min value minus the basal value. RESULTS: At 30 min after meal ingestion, the glucagon level showed no difference relative to the basal value, whereas glucose, C-peptide, iGLP-1, and iGIP levels showed a significant increase. In univariate analysis, Δglucagon showed not only a strong correlation with HbA1c but also a significant correlation with fasting glucose, Δglucose, and estimated glomerular filtration rate. However, Δglucagon showed no significant correlations with ΔiGLP-1 and ΔiGIP. In the hierarchical multiple regression analysis, HbA1c was the only variable that continued to show the most significant correlation with Δglucagon. CONCLUSIONS: People with diabetes showed no suppression of glucagon secretion after meal ingestion. Patients with poorer glycemic control may show greater increase in postprandial glucagon level, and this does not appear to be mediated by incretin.

14.
Mater Sci Eng C Mater Biol Appl ; 131: 112521, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34857300

RESUMO

Efficient and selective targeting of inflamed tissues/organs is critical for diagnosis and therapy. Although nanomaterials themselves have an intrinsic advantage due to their size for targeting inflammation sites, additional functionalization of the nanomaterials with proper targeting moieties is desired to enhance the targeting efficiency. In this study, we aimed to improve the inflammation targeting characteristics of a pluronic-based nanocarrier, which has advantages as a nanosized delivery cargo for diverse molecules, by conjugating with chitosan and ZnBPMP (two Zn(II) ions chelated 2,6-bis[(bis(2-pyridylmethyl)amino)-methyl]-4-methylphenol) moiety. Specific and significant cellular uptake and interaction between the nanocarrier functionalized with ZnBPMP ligand and chitosan to an apoptosis-induced immune cell line were observed in vitro. An inflammation model in the mouse ear caused by skin hypersensitivity was used to evaluate the effect of functionalization with chitosan and ZnBPMP moiety by comparing with various control groups. Functionalization of the nanocarrier with chitosan greatly enhanced the in vivo circulation time of the nanocarrier, so prolonged targeting ability of the nanocarrier to the inflamed ear was achieved. Additional ZnBPMP functionalization to chitosan-functionalized nanocarrier also resulted in significantly improved initial targeting and further enhancement in the targeting until 5 days to the inflamed ear and the decreased non-specific accumulation of the nanocarrier to the remaining body. Thus, developed nanocarrier has a high potential as a drug delivery carrier as well as a diagnostic agent to the inflammation sites.


Assuntos
Quitosana , Nanopartículas , Animais , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Inflamação/tratamento farmacológico , Camundongos , Poloxâmero
15.
Nanoscale ; 13(8): 4467-4474, 2021 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-33503078

RESUMO

A simple paper-based analytical device (PAD) for the one-pot detection of glucose was developed herein using an artificial peroxidase-functionalized and glucose oxidase (GOx)-loaded pluronic-based nanocarrier (PNC). Mn2BPMP (BPMP; 2,6-bis[(bis(2-pyridylmethyl)amino)-methyl]-4-methylphenolate), an artificial peroxidase, was conjugated to PNC, allowing GOx to be loaded with a very high encapsulation efficiency. In solution, Mn2BPMP-PNC showed higher peroxidase-like catalytic efficiency than did Mn2BPMP at physiological pH. In addition, glucose detection via enzyme cascade reaction between GOx and Mn2BPMP in the GOx loaded-Mn2BPMP-PNC was more sensitive than the simple combination of Mn2BPMP and GOx with excellent selectivity. Subsequently, a PAD was fabricated using a laser printer with an assay substance containing GOx loaded-Mn2BPMP-PNC and peroxidase chromogenic substrate. The prepared Mn2BPMP-PNC-based PAD quantitatively measured glucose in human serum ranging from normal levels to those typical for diabetics as well as in buffer by obtaining RGB (red, green, and blue) color values through smartphone readout or the naked eye. Importantly, the present PNC-based PAD maintained the detection efficiency during storage at room temperature for 6 weeks in contrast to the rapid decrease in detection efficiency obtained for PAD containing Mn2BPMP and GOx without PNC.


Assuntos
Técnicas Biossensoriais , Glucose Oxidase , Glucose , Humanos , Peroxidase , Peroxidases , Smartphone
16.
Free Radic Biol Med ; 153: 17-25, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32305647

RESUMO

Pancreatic ß-cells are vulnerable to oxidative stress, which promotes ß-cell failure in type 2 diabetes. System χc- is a sodium-independent, cystine/glutamate antiporter that mediates the exchange of extracellular l-cystine and intracellular l-glutamate. The import of l-cystine through this transporter is the rate-limiting step in the glutathione (GSH) biosynthesis pathway that plays a significant role in antioxidative defense. Previously, we reported that 2-deoxy-d-ribose (dRib) induces oxidative damage through GSH depletion in pancreatic ß-cells. In the current study, we elucidated the mechanism underlying the oxidative stress-induced ß-cell damage. We measured the intracellular l-[14C]cystine uptake, GSH content, reactive oxygen species (ROS) levels, cytotoxicity, and apoptosis in rat insulinoma cell line, RINm5F. Treatment of dRib decreased the intracellular l-[14C]cystine uptake and GSH content and increased the intracellular ROS levels, cytotoxicity, and apoptosis in a time- and dose-dependent manner. Conversely, 2-mercaptoethanol (2-ME), a cystine uptake enhancer, recovered the dRib-induced decrease in l-[14C]cystine uptake, GSH content, and cell viability in a Na+-independent manner. In the case of isolated islets, dRib dose-dependently decreased the intracellular l-[14C]cystine uptake and cell viability; however, dRib-induced cytotoxicity was completely recovered by adding N-acetyl cysteine (NAC). To confirm that system χc- mediates the oxidative stress-induced ß-cell damage, we overexpressed xCT (the substrate-specific subunit of system χc-) using a lentiviral vector in RINm5F cells. Overexpression of xCT fully recovered the dRib-induced decrease in l-[14C]cystine uptake and GSH content and prevented the dRib-induced increase in ROS levels, cytotoxicity, and apoptosis. The overexpression of xCT showed a protective effect against dRib-induced oxidative damage in RINm5F cells. Our study showed that dRib depletes intracellular GSH content through inhibition of cystine transport via system χc- in ß-cells.


Assuntos
Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Sistema y+ de Transporte de Aminoácidos/genética , Sistema y+ de Transporte de Aminoácidos/metabolismo , Animais , Cistina/metabolismo , Desoxirribose/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Glutationa/metabolismo , Células Secretoras de Insulina/metabolismo , Estresse Oxidativo , Ratos , Ribose/metabolismo
17.
Endocrinol Metab (Seoul) ; 35(2): 290-297, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32615713

RESUMO

BACKGROUND: This study aimed to identify factors that affect fasting hyperglycemia (FHG) and postprandial hyperglycemia (PPG) and their contributions to overall hyperglycemia in Korean patients with type 2 diabetes mellitus (T2DM). METHODS: This was a retrospective study conducted on 194 Korean T2DM patients with 7-point self-monitoring blood glucose (SMBG) profiles plotted in 4 days in 3 consecutive months. We calculated the areas corresponding to FHG and PPG (area under the curve [AUC]FHG and AUCPPG) and contributions (%) in the graph of the 7-point SMBG data. The levels of glycated hemoglobin (HbA1c) were categorized by tertiles, and the contributions of FHG and PPG were compared. RESULTS: The relative contribution of FHG increased (44.7%±5.6%, 58.0%±4.4%, 66.5%±2.8%; PANOVA=0.002, PTREND <0.001), while that of PPG decreased (55.3%±5.5%, 42.0%±4.4%, 33.5%±2.8%; PANOVA=0.002, PTREND <0.001) with the elevated HbA1c. Multivariate analysis showed that HbA1c (ß=0.615, P<0.001), waist circumference (ß=0.216, P=0.042), and triglyceride (ß=0.121, P=0.048) had a significant association with AUCFHG. Only HbA1c (ß=0.231, P=0.002) and age (ß=0.196, P=0.009) was significantly associated with AUCPPG. CONCLUSION: The data suggested that in Korean T2DM patients, FHG predominantly contributed to overall hyperglycemia at higher HbA1c levels, whereas it contributed to PPG at lower HbA1c levels. It is recommended that certain factors, namely age, degree of glycemic control, obesity, or triglyceride levels, should be considered when prescribing medications for T2DM patients.


Assuntos
Biomarcadores/análise , Diabetes Mellitus Tipo 2/fisiopatologia , Jejum , Hiperglicemia/epidemiologia , Período Pós-Prandial , Adulto , Idoso , Idoso de 80 Anos ou mais , Glicemia/análise , Automonitorização da Glicemia/métodos , Feminino , Seguimentos , Hemoglobinas Glicadas/análise , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , República da Coreia/epidemiologia , Estudos Retrospectivos , Adulto Jovem
18.
J Lipid Atheroscler ; 9(1): 162-171, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32821729

RESUMO

OBJECTIVE: Postmenopausal women show a more atherogenic lipid profile and elevated cardiovascular risk compared to premenopausal women. The aim of this study was to investigate the efficacy and safety of high-dose atorvastatin on the improvement of the blood lipid profile of postmenopausal women in Korea. METHODS: This study is a prospective, open-label, single-arm clinical trial that was conducted in 3 teaching hospitals. Postmenopausal women with a moderate-to-high cardiovascular risk, according to guidelines from the Korean Society of Lipid & Atherosclerosis, were enrolled. Participants were administered 20 mg of atorvastatin daily for the first 8 weeks, and if the targeted low-density lipoprotein cholesterol (LDL-C) level was not achieved, the dose was increased to 40 mg for the second 8 weeks. The primary endpoint was percentage change of LDL-C from baseline after 16 weeks of drug administration. RESULTS: Forty-four women were enrolled, 28 of whom (75.6%) had diabetes mellitus. By the end of treatment period (16 weeks) all patients had achieved LDL-C target levels, with 33 (94.2%) of the participants achieving it after only 8 weeks of administration. After 16 weeks, LDL-C decreased by 45.8±16.7% (p<0.001) from the baseline, and total cholesterol (33.2±10.9%; p<0.001), triglyceride (24.2±37.5%; p=0.001), and apolipoprotein B (34.9±15.6%; p<0.001) also significantly decreased. Blood glucose and liver enzyme levels slightly increased, but none of the participants developed serious adverse events that would cause them to prematurely withdraw from the clinical trial. CONCLUSION: 20 and 40 mg atorvastatin was effective and safe for treating dyslipidemia in postmenopausal Korean women with moderate-to-high cardiovascular risk.

19.
ACS Appl Bio Mater ; 3(8): 5126-5135, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-35021689

RESUMO

Enzyme immobilization is very important for diverse enzyme applications. Particularly, there is a growing need for coimmobilization of multiple enzymes for biosensing and synthetic applications. However, it is still challenging to coimmobilize two enzymes with desirable features, including high immobilization yield, retention of enzymatic activity, and low leaching. In this study, we demonstrated that a pluronic-based nanocarrier (PNC) can be an encapsulation platform for immobilization of various single enzymes. Since the PNC is temperature-sensitive, a simple temperature change from 4 to 37 °C led to a substantial size reduction and enzyme encapsulation. All six enzymes tested were encapsulated by the PNC in high yield (∼90%) with the retained enzymatic activity (>95%). The leaching of encapsulated enzymes was very minimal (<0.13% for 2 weeks). Then, we demonstrated that the PNC can efficiently coencapsulate two enzymes, formate dehydrogenase (FDH) and mannitol dehydrogenase (MDH), for a cascade reaction producing d-mannitol. Coencapsulation of FDH and MDH resulted in an over 10-fold increase in d-mannitol production compared to the free mix of FDH and MDH, likely due to the enhanced local concentrations of FDH and MDH inside the PNC.

20.
Front Med (Lausanne) ; 7: 606976, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33392229

RESUMO

Candidemia is an important healthcare-associated infection (HAI) in intensive care units (ICUs). However, limited research has been conducted on candidemia in the Republic of Korea. We aimed to analyze the secular trends in the incidence and distribution of candidemia in ICUs over 12-years using data from the Korean National Healthcare-Associated Infections Surveillance System (KONIS). KONIS was established in 2006 and has performed prospective surveillance of HAIs including bloodstream infections (BSIs) in ICUs. We evaluated the trends in the distribution of causative pathogens and the incidence of candidemia. From 2006 to 2017, 2,248 candidemia cases occurred in 9,184,264 patient-days (PDs). The pooled mean incidence rates of candidemia significantly decreased from 3.05 cases/10,000 PDs in 2006 to 2.5 cases/10,000 PDs in 2017 (P = 0.001). Nevertheless, the proportion of candidemia gradually increased from 15.2% in 2006 to 16.6% in 2017 (P = 0.001). The most frequent causative pathogen of BSIs from 2006 to 2012 was Staphylococcus aureus; however, Candida spp. emerged as the most frequent causative pathogen since 2013. C. albicans (39.9%) was the most common among Candida spp. causing BSIs, followed by Candida tropicalis (20.2%) and Candida parapsilosis (18.2%). The proportion of candidemia caused by C. glabrata significantly increased from 8.9% in 2006 to 17.9% in 2017 (P < 0.001). There was no significant change in the distribution of Candida spp. by year (P = 0.285). The most common source of BSIs was central lines associated BSI (92.5%). There was a significant increase in the proportion of candidemia by year in hospitals with organ transplant wards (from 18.9% in 2006 to 21.1% in 2017, P = 0.003), hospitals with <500 beds (from 2.7% in 2006 to 13.6% in 2017, P < 0.001), and surgical ICUs (from 16.2% in 2006 to 21.7% in 2017, P = 0.003). The proportion of candidemia has increased in Korea, especially in hospitals with <500 beds and surgical ICUs. Thus, appropriate infection control programs are needed.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa