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1.
Blood Purif ; 52(4): 323-331, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36889302

RESUMO

INTRODUCTION: Cardiovascular (CV) events are the major cause of morbidity and mortality associated with blood pressure (BP) in hemodialysis (HD) patients. BP varies significantly during HD treatment, and the dramatic variation in BP is a well-recognized risk factor for increased mortality. The development of an intelligent system capable of predicting BP profiles for real-time monitoring is important. Our aim was to build a web-based system to predict changes in systolic BP (SBP) during HD. METHODS: In this study, dialysis equipment connected to the Vital Info Portal gateway collected HD parameters that were linked to demographic data stored in the hospital information system. There were 3 types of patients: training, test, and new. A multiple linear regression model was built using the training group with SBP change as the dependent variable and dialysis parameters as the independent variables. We tested the model's performance on test and new patient groups using coverage rates with different thresholds. The model's performance was visualized using a web-based interactive system. RESULTS: A total of 542,424 BP records were used for model building. The accuracy was greater than 80% in the prediction error range of 15%, and 20 mm Hg of true SBP in the test and new patient groups for the model of SBP changes suggested the good performance of our prediction model. In the analysis of absolute SBP values (5, 10, 15, 20, and 25 mm Hg), the accuracy of the SBP prediction increased as the threshold value increased. DISCUSSION: This databae supported our prediction model in reducing the frequency of intradialytic SBP variability, which may help in clinical decision-making when a new patient receives HD treatment. Further investigations are needed to determine whether the introduction of the intelligent SBP prediction system decreases the incidence of CV events in HD patients.


Assuntos
Big Data , Diálise Renal , Humanos , Pressão Sanguínea , Diálise Renal/efeitos adversos , Fatores de Risco , Análise Multivariada
2.
Int J Mol Sci ; 24(13)2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37446114

RESUMO

Circulating uremic toxin indoxyl sulfate (IS), endothelial cell (EC) dysfunction, and decreased nitric oxide (NO) bioavailability are found in chronic kidney disease patients. NO nitrosylates/denitrosylates a specific protein's cysteine residue(s), forming S-nitrosothios (SNOs), and the decreased NO bioavailability could interfere with NO-mediated signaling events. We were interested in investigating the underlying mechanism(s) of the reduced NO and how it would regulate the S-nitrosylation of tissue transglutaminase (TG2) and its substrates on glycolytic, redox and inflammatory responses in normal and IS-induced EC injury. TG2, a therapeutic target for fibrosis, has a Ca2+-dependent transamidase (TGase) that is modulated by S-nitrosylation. We found IS increased oxidative stress, reduced NADPH and GSH levels, and uncoupled eNOS to generate NO. Immunoblot analysis demonstrated the upregulation of an angiotensin-converting enzyme (ACE) and significant downregulation of the beneficial ACE2 isoform that could contribute to oxidative stress in IS-induced injury. An in situ TGase assay demonstrated IS-activated TG2/TGase aminylated eNOS, NFkB, IkBα, PKM2, G6PD, GAPDH, and fibronectin (FN), leading to caspases activation. Except for FN, TGase substrates were all differentially S-nitrosylated either with or without IS but were denitrosylated in the presence of a specific, irreversible TG2/TGase inhibitor ZDON, suggesting ZDON-bound TG2 was not effectively transnitrosylating to TG2/TGase substrates. The data suggest novel roles of TG2 in the aminylation of its substrates and could also potentially function as a Cys-to-Cys S-nitrosylase to exert NO's bioactivity to its substrates and modulate glycolysis, redox, and inflammation in normal and IS-induced EC injury.


Assuntos
Indicã , Proteína 2 Glutamina gama-Glutamiltransferase , Humanos , Células Endoteliais , Estresse Oxidativo , Glicólise , Sulfatos
3.
Int J Mol Sci ; 25(1)2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38203500

RESUMO

Diabetic nephropathy (DN) is a crucial metabolic health problem. The renin-angiotensin system (RAS) is well known to play an important role in DN. Abnormal RAS activity can cause the over-accumulation of angiotensin II (Ang II). Angiotensin-converting enzyme inhibitor (ACEI) administration has been proposed as a therapy, but previous studies have also indicated that chymase, the enzyme that hydrolyzes angiotensin I to Ang II in an ACE-independent pathway, may play an important role in the progression of DN. Therefore, this study established a model of severe DN progression in a db/db and ACE2 KO mouse model (db and ACE2 double-gene-knockout mice) to explore the roles of RAS factors in DNA and changes in their activity after short-term (only 4 weeks) feeding of a high-fat diet (HFD) to 8-week-old mice. The results indicate that FD-fed db/db and ACE2 KO mice fed an HFD represent a good model for investigating the role of RAS in DN. An HFD promotes the activation of MAPK, including p-JNK and p-p38, as well as the RAS signaling pathway, leading to renal damage in mice. Blocking Ang II/AT1R could alleviate the progression of DN after administration of ACEI or chymase inhibitor (CI). Both ACE and chymase are highly involved in Ang II generation in HFD-induced DN; therefore, ACEI and CI are potential treatments for DN.


Assuntos
Diabetes Mellitus , Nefropatias Diabéticas , Hormônios Peptídicos , Animais , Camundongos , Angiotensina II , Enzima de Conversão de Angiotensina 2/genética , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Antivirais , Quimases/genética , Nefropatias Diabéticas/genética , Dieta Hiperlipídica , Modelos Animais de Doenças , Camundongos Knockout , Sistema Renina-Angiotensina , Serina Proteases
4.
J Biomed Sci ; 28(1): 73, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34724959

RESUMO

BACKGROUND: Renal erythropoietin (EPO)-producing (REP) cells produce EPO through hypoxia-inducible factor (HIF) 2α-activated gene transcription. Insufficient EPO production leads to anemia in patients with chronic kidney disease. Although recombinant EPO is effective to improve anemia, no reliable REP cell lines limit further progress of research and development of novel treatment. METHODS: We screened Epo mRNA expression in mouse fibroblast cell lines. Small interfering RNA specific for HIF1α or HIF2α was transfected to study Epo expression in C3H10T1/2 cells. The effect of transforming growth factor-ß1 (TGF-ß1) on HIF-EPO axis was studied in C3H10T1/2 cells and mice. RESULTS: Similar to mouse REP pericytes, C3H10T1/2 cells differentiated to α-smooth muscle actin+ myofibroblasts after exposure to TGF-ß1. Specific HIF knockdown demonstrated the role of HIF2α in hypoxia-induced Epo expression. Sustained TGF-ß1 exposure increased neither DNA methyltransferase nor methylation of Epas1 and Epo genes. However, TGF-ß1 repressed HIF2α-encoding Epas1 promptly through activating activin receptor-like kinase-5 (ALK5), thereby decreasing Epo induction by hypoxia and prolyl hydroxylase domain inhibitor roxadustat. In mice with pro-fibrotic injury induced by ureteral obstruction, upregulation of Tgfb1 was accompanied with downregulation of Epas1 and Epo in injured kidneys and myofibroblasts, which were reversed by ALK5 inhibitor SB431542. CONCLUSION: C3H10T1/2 cells possessed the property of HIF2α-dependent Epo expression in REP pericytes. TGF-ß1 induced not only the transition to myofibroblasts but also a repressive effect on Epas1-Epo axis in C3H10T1/2 cells. The repressive effect of TGF-ß1 on Epas1-Epo axis was confirmed in REP pericytes in vivo. Inhibition of TGF-ß1-ALK5 signaling might provide a novel treatment to rescue EPO expression in REP pericytes of injured kidney.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Eritropoetina/genética , Fator de Crescimento Transformador beta1/genética , Células 3T3 , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Eritropoetina/metabolismo , Fibroblastos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fator de Crescimento Transformador beta1/metabolismo
5.
World J Surg ; 44(3): 795-802, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31659413

RESUMO

BACKGROUND: Hungry bone syndrome is characterized by prolonged and severe hypocalcemia following parathyroidectomy. Previously, we reported that preoperative alkaline phosphatase is a major factor predicting prolonged hospital stay. Nonetheless, some patients with low alkaline phosphatase levels presented with hungry bone syndrome, suggesting that additional factors may play a role. METHODS: From September 2010 to December 2017, consecutive dialysis patients who underwent parathyroidectomy for secondary hyperparathyroidism were analyzed. Length of hospital stay was used as a surrogate marker for postoperative bone hunger. RESULTS: A total of 260 patients were included in the study. The median postoperative hospital stay was 3 days, and 69 (27%) patients had a stay longer than 3 days. Multivariate logistic regression analysis revealed that alkaline phosphatase (odds ratio [OR] = 1.005), osteocalcin (OR = 1.001), and subtotal parathyroidectomy (OR = 0.061) were associated with prolonged hospital stay. Multivariate linear regression analysis indicated that age (ß = - 0.170), alkaline phosphatase (ß = 0.430), and osteocalcin (ß = 0.166) were correlated with the length of stay. After surgery, the median osteocalcin level increased from 264 to 478 ng/mL (P < 0.001). CONCLUSIONS: Alkaline phosphatase is the main predictor of hungry bone syndrome after parathyroidectomy, and preoperative osteocalcin is an additional independent predictor. Patients with a high osteocalcin level may prone to have a higher demand for calcium supplementation.


Assuntos
Hiperparatireoidismo Secundário/cirurgia , Hipocalcemia/etiologia , Osteocalcina/sangue , Paratireoidectomia/efeitos adversos , Adulto , Fosfatase Alcalina/sangue , Feminino , Humanos , Hiperparatireoidismo Secundário/sangue , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Diálise Renal
6.
Int J Mol Sci ; 21(4)2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32070049

RESUMO

Indoxyl sulphate (IS) and p-cresyl sulphate (PCS) are two protein bound uraemic toxins accumulated in chronic kidney disease (CKD) and associated with adverse outcomes. The purpose of this study isto evaluate the effect of the new activated charcoal, CharXgen, on renal function protection and lowering serum uraemic toxins in CKD animal model. The physical character of CharXgen was analyzed before and after activation procedure by Scanning Electron Microscope (SEM) and X-ray diffractometer (XRD). The effect of CharXgen on biochemistry and lowering uremic toxins was evaluated by in vitro binding assay and CKD animal model. CharXgen have high interior surface area analyzed by SEM and XRD and have been produced from local bamboo after an activation process. CharXgen was able to effectively absorb IS, p-cresol and phosphate in an in vitro gastrointestinal tract simulation study. The animal study showed that CharXgen did not cause intestine blackening. Serum albuminand liver function did not change after feeding with CharXgen. Moreover, renal function was improved in CKD rats fed with CharXgen as compared to the CKD group, and there were no significant differences in the CKD and the CKD + AST-120 groups. Serum IS and PCS were higher in the CKD group and lower in rats treated with CharXgen and AST-120. In rats treated with CharXgen, Fibroblast growth factor 23 was significantly decreased as compared to the CKD group. This change cannot be found in rats fed with AST-120.It indicates that CharXgen is a new safe and non-toxic activated charcoal having potential in attenuating renal function deterioration and lowering protein-bound uraemic toxins. Whether the introduction of this new charcoal could further have renal protection in CKD patients will need to be investigated further.


Assuntos
Carvão Vegetal/farmacologia , Insuficiência Renal Crônica/tratamento farmacológico , Sasa/química , Toxinas Biológicas/sangue , Uremia/tratamento farmacológico , Alginatos/química , Alginatos/farmacologia , Animais , Carbono/farmacologia , Linhagem Celular , Cresóis/farmacologia , Modelos Animais de Doenças , Humanos , Indicã/farmacologia , Microscopia Eletrônica de Varredura , Microesferas , Óxidos/farmacologia , Ratos , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/patologia , Ésteres do Ácido Sulfúrico/farmacologia , Uremia/sangue , Uremia/complicações , Uremia/patologia
7.
J Surg Res ; 224: 169-175, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29506836

RESUMO

BACKGROUND: Systemic inflammation has been implicated in complications and heightened mortality of patients with secondary hyperparathyroidism. The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are widely available surrogate markers of inflammation. This study sought to delineate the changes in NLR and PLR after parathyroidectomy. METHODS: A total of 213 patients undergoing initial parathyroidectomy from 2010 to 2015 for secondary hyperparathyroidism were identified from a prospectively maintained clinical database. Among 183 patients free of persistent or recurrent disease, follow-up NLR and PLR were available for analysis in 85 patients. RESULTS: In the whole study population, the baseline NLR was positively correlated with male sex, total white blood cell count, height, serum phosphorus, and calcium-phosphorus product levels. The baseline PLR was positively correlated with platelet count, serum phosphorus, and calcium-phosphorus product levels and negatively associated with patient age. Postoperative parathyroid hormone levels were positively correlated with NLR and PLR at follow-up. For patients who had successful parathyroidectomy, there was a decrease in NLR (P = 0.0006), PLR (P = 0.0003), and platelet count (P = 0.033), whereas hemoglobin significantly increased (P = 0.0002) after surgery. Those with persistent or recurrent hyperparathyroidism had no change in NLR, PLR, hemoglobin, total white blood cell, or platelet count. CONCLUSIONS: Successful parathyroidectomy is associated with a decrease in NLR and PLR. The modulatory effects of parathyroidectomy on systemic inflammation may partially explain the benefits of surgery in secondary hyperparathyroidism.


Assuntos
Plaquetas , Hiperparatireoidismo Secundário/cirurgia , Linfócitos , Neutrófilos , Paratireoidectomia , Feminino , Humanos , Hiperparatireoidismo Secundário/sangue , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Recidiva
8.
Kidney Blood Press Res ; 43(5): 1636-1645, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30380558

RESUMO

BACKGROUND/AIMS: Fabry disease (FD), a rare x-lined genetic disorder is a cause of renal deterioration. The phenotype of FD is highly variable and nonspecific, and correct diagnosis has always been delayed. We aimed to explore the prevalence and clinical presentation of FD in this high-risk male population in a Northern Taiwan medical center. METHODS: This is the first study to survey the incidence of FD in this high-risk population through the platform of a chronic kidney disease (CKD) education program in Asia. A total of 1,012 male patients with unknown CKD causes were screened using an assay of alpha-galactosidase A activity (α-Gal A) by dried blood spots (DBS). A final GLA gene analysis was also done for those with low enzyme activity. RESULTS: We identified two new patients with classic FD and four patients with late-onset FD. One novel GLA mutation with c.413 G>A was found in one classic FD patient (index 5). The prevalence of FD is about 0.59 % (6 in 1,012) in the high-risk population group with CKD. The clinical symptoms of FD patients are nonspecific except in those with various degrees of renal failure. Those patients' correct diagnosis was delayed, taking years and even decades. Three patients received enzyme replacement therapy and one started regular hemodialysis due to persistent renal function deterioration. Another two patients were found from family screening through a new index. In addition, a false negative result occurred in one patient who was proved to have FD by his kidney pathology as determined by this screening. CONCLUSION: FD is not such as rare a disease and its prevalence is greater in this high-risk male population. Clinicians need to be aware that FD should be included in the differential diagnosis in CKD with unknown etiology.


Assuntos
Doença de Fabry/diagnóstico , Falência Renal Crônica/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Doença de Fabry/epidemiologia , Humanos , Isoenzimas/sangue , Isoenzimas/genética , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Prevalência , Proteínas Recombinantes/sangue , Proteínas Recombinantes/genética , Insuficiência Renal Crônica , Taiwan , Adulto Jovem , alfa-Galactosidase/sangue , alfa-Galactosidase/genética
9.
J Formos Med Assoc ; 117(11): 955-963, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29655605

RESUMO

Anemia is a common complication and contributes to increased morbidity and mortality in chronic kidney disease (CKD) patients. Whereas there has been a significant improvement of understanding the underlying mechanism of erythropoiesis, the treatment of renal anemia is still restricted to erythropoietin (EPO)-stimulating agents. The purpose of this article is to review the physiology of erythropoiesis, functional role of EPO and underlying molecular and cellular basis that regulate EPO production. Regulation of EPO production is at mRNA level. When anemia or hypoxia occurs, transcriptional factor, hypoxia-inducible factor (HIF), binds to EPO 5' hypoxic response element and EPO gene transcription increases. The renal EPO is mainly produced by pericytes. In CKD, pericytes transdifferentiate to myofibroblasts, and subsequently the ability of EPO production decreases, leading to renal anemia. Recent experimental and clinical studies show the promising efficacy of prolyl hydroxylase inhibitors in renal anemia through increasing EPO production by stabilizing HIF. Recent advances on epigenetics create a new field to study EPO gene expression at chromatin level. We will discuss the role of demethylating agent on restoring EPO expression, providing a novel approach to the treatment of renal anemia.


Assuntos
Anemia/genética , Eritropoese , Eritropoetina/fisiologia , Miofibroblastos/metabolismo , Insuficiência Renal Crônica/complicações , Anemia/tratamento farmacológico , Anemia/etiologia , Animais , Eritropoetina/genética , Regulação da Expressão Gênica , Humanos , Fator 1 Induzível por Hipóxia/metabolismo , Pericitos/metabolismo
10.
J Formos Med Assoc ; 117(10): 888-893, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29941330

RESUMO

BACKGROUND: Intradialytic hypotension (IDH) is a serious complication and a major risk factor of increased mortality during hemodialysis (HD). However, predicting the occurrence of intradialytic blood pressure (BP) fluctuations clinically is difficult. This study aimed to develop an intelligent system with capability of predicting IDH. METHODS: In developing and training the prediction models in the intelligent system, we used a database of 653 HD outpatients who underwent 55,516 HD treatment sessions, resulting in 285,705 valid BP records. We built models to predict IDH at the next BP check by applying time-dependent logistic regression analyses. RESULTS: Our results showed the sensitivity of 86% and specificity of 81% for both nadir systolic BP (SBP) of <90 mmHg and <100 mmHg, suggesting good performance of our prediction models. We obtained similar results in validating via test data and data of newly enrolled patients (new-patient data), which is important for simulating prospective situations wherein dialysis staff are unfamiliar with new patients. This compensates for the retrospective nature of the BP records used in our study. CONCLUSION: The use of this validated intelligent system can identify patients who are at risk of IDH in advance, which may facilitate well-timed personalized management and intervention.


Assuntos
Monitores de Pressão Arterial , Hipotensão/diagnóstico , Diálise Renal/efeitos adversos , Idoso , Pressão Sanguínea , Bases de Dados Factuais , Feminino , Humanos , Hipotensão/etiologia , Hipotensão/fisiopatologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC , Estudos Retrospectivos , Fatores de Risco , Taiwan
11.
Kidney Blood Press Res ; 41(6): 1025-1036, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28006782

RESUMO

BACKGROUND/AIMS: Indoxyl sulfate (IS) is a protein-bound uremic toxin that accumulates in patients with chronic kidney disease (CKD). We explored the effect of IS on human early endothelial progenitor cells (EPCs) and analyzed the correlation between serum IS levels and parameters of vascular function, including endothelial function in a CKD-based cohort. METHODS: A cross-sectional study with 128 stable CKD patients was conducted. Flow-mediated dilation (FMD), pulse wave velocity (PWV), ankle brachial index, serum IS and other biochemical parameters were measured and analyzed. In parallel, the activity of early EPCs was also evaluated after exposure to IS. RESULTS: In human EPCs, a concentration-dependent inhibitory effect of IS on chemotactic motility and colony formation was observed. Additionally, serum IS levels were significantly correlated with CKD stages. The total IS (T-IS) and free IS (F-IS) were strongly associated with age, hypertension, cardiovascular disease, blood pressure, PWV, blood urea nitrogen, creatine and phosphate but negatively correlated with FMD, the estimated glomerular filtration rate (eGFR), hemoglobin, hematocrit, and calcium. A multivariate linear regression analysis also showed that FMD was significantly associated with IS after adjusting for other confounding factors. CONCLUSIONS: In humans, IS impairs early EPCs and was strongly correlated with vascular dysfunction. Thus, we speculate that this adverse effect of IS may partly result from the inhibition of early EPCs.


Assuntos
Células Progenitoras Endoteliais/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Indicã/efeitos adversos , Insuficiência Renal Crônica/patologia , Idoso , Células Cultivadas , Estudos Transversais , Técnicas de Diagnóstico Cardiovascular , Células Progenitoras Endoteliais/citologia , Endotélio Vascular/efeitos dos fármacos , Feminino , Humanos , Indicã/sangue , Masculino , Pessoa de Meia-Idade
12.
Nephrology (Carlton) ; 21(9): 758-64, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27546777

RESUMO

AIM: Acute kidney injury (AKI) carries an increasing incidence rate worldwide and increases the risk of developing end-stage renal disease (ESRD) as well as the medical expenses during the post-AKI course. The Taiwan Consortium for Acute Kidney Injury and Renal Diseases (CAKs) has thus launched a nationwide epidemiology and prognosis of dialysis-requiring acute kidney injury (NEP-AKI-D) study, which prospectively enrols critically ill patients with AKI. Through thoroughly evaluating the risk and prognostic factors of AKI, we hope to lower the incidence of AKI and ESRD from the perspective of AKI-ESRD interaction. METHODS: The CAKs includes 30 hospitals which distribute widely through the four geographical regions (north, middle, south, and east) of Taiwan, and have a 1:1 ratio of medical centres to regional hospitals in each region. The NEP-AKI-D study enrols intensive care unit-based AKI patients who receive dialysis in the four seasonal sampled months (October 2014, along with January, April, and July 2015) in the included hospitals. The collected data include demographic information, pertaining laboratory results, dialysis settings and patient outcomes. The data are uploaded in a centre website and will be audited by on-site principal investigators, computer logic gates, and the CAKs staffs. The outcomes of interest are in-hospital mortality, dialysis-dependency and readmission rate within 90 days after discharge. CONCLUSION: The NEP-AKI-D study enrols a large number of representative AKI patients throughout Taiwan. The results of the current study are expected to provide more insight into the risk and prognostic factors of AKI and further attenuated further chronic kidney disease transition.


Assuntos
Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/terapia , Projetos de Pesquisa Epidemiológica , Diálise Renal , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/mortalidade , Estado Terminal , Bases de Dados Factuais , Progressão da Doença , Mortalidade Hospitalar , Humanos , Incidência , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/epidemiologia , Falência Renal Crônica/terapia , Readmissão do Paciente , Estudos Prospectivos , Fatores de Risco , Taiwan/epidemiologia , Fatores de Tempo , Resultado do Tratamento
13.
J Xray Sci Technol ; 24(6): 875-892, 2016 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-27612051

RESUMO

The purpose of this study was to develop an ultrasound image tracking algorithm (UITA) for extracting the exact displacement of internal organs caused by respiratory motion. The program can track organ displacements in real time, and analyze the displacement signals associated with organ displacements via a respiration compensating system (RCS). The ultrasound imaging system is noninvasive and has a high spatial resolution and a high frame rate (around 32 frames/s), which reduces the radiation doses that patients receive during computed tomography and X-ray observations. This allows for the continuous noninvasive observation and compensation of organ displacements simultaneously during a radiation therapy session.This study designed a UITA for tracking the motion of a specific target, such as the human diaphragm. Simulated diaphragm motion driven by a respiration simulation system was observed with an ultrasound imaging system, and then the induced diaphragm displacements were calculated by our proposed UITA. These signals were used to adjust the gain of the RCS so that the amplitudes of the compensation signals were close to the target movements. The inclination angle of the ultrasound probe with respect to the surface of the abdomen affects the results of ultrasound image displacement tracking. Therefore, the displacement of the phantom was verified by a LINAC with different inclination-angle settings of the ultrasound probe. The experimental results indicate that the best inclination angle of the ultrasound probe is 40 degrees, since this results in the target displacement of the ultrasound images being close to the actual target motion. The displacement signals of the tracking phantom and the opposing displacement signals created by the RCS were compared to assess the positioning accuracy of our proposed ultrasound image tracking technique combined with the RCS.When the ultrasound probe was inclined by 40 degrees in simulated respiration experiments using sine waves, the correlation between the target displacement on the ultrasound images and the actual target displacement was around 97%, and all of the compensation rates exceeded 94% after activating the RCS. Furthermore, the diaphragm movements on the ultrasound images of three patients could be captured by our image tracking technique. The test results show that our algorithm could achieve precise point locking and tracking functions on the diaphragm. This study has demonstrated the feasibility of the proposed ultrasound image tracking technique combined with the RCS for compensating for organ displacements caused by respiratory motion.This study has shown that the proposed ultrasound image tracking technique combined with the RCS can provide real-time compensation of respiratory motion during radiation therapy, without increasing the overall treatment time. In addition, the system has modest space requirements and is easy to operate.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Movimento/fisiologia , Respiração , Ultrassonografia/métodos , Adulto , Algoritmos , Diafragma/diagnóstico por imagem , Desenho de Equipamento , Humanos , Masculino , Imagens de Fantasmas , Tomografia Computadorizada por Raios X , Adulto Jovem
14.
Kidney Blood Press Res ; 40(2): 121-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25833743

RESUMO

BACKGROUND/AIMS: Advanced glycation end products (AGEs) are pro-inflammatory and pro-oxidative compounds that play a critical role in endothelial dysfunction and atherosclerosis. Protein-bound uremic toxins, indoxyl sulfate (IS) and p-cresyl sulfate (PCS), inhibit endothelial function. We explored the association of IS and PCS with AGEs in a hemodialysis (HD) cohort. METHODS: This study was a cross-sectional study that recruited 129 stable patients on maintenance HD in a single medical center from July 1 to July 15, 2011. Serum levels of total and free IS, PCS and AGEs were measured concurrently. General laboratory results and patient background were also investigated. RESULTS: Serum levels of AGEs were associated with total IS (r = 2.7, p < 0.01) but not total PCS (r = 0.01, NS), free IS (r = 0.11, NS) or free PCS (r = 0.04, NS) using Pearson's analysis. Multiple linear regression analysis showed that total IS was significantly related to AGEs (ß = 0.296, p < 0.01), free IS (ß = 0.502, p < 0.01) and creatinine (ß = 0.294, p < 0.01). Serum AGEs levels were also independently correlated with diabetes status (ß = 0.250, p = 0.01) and total IS (ß = 0.341, p < 0.01) concentrations after adjusting for other confounding variables. Moreover, patients with diabetes had higher serum AGEs levels than patients without diabetes (p < 0.01). CONCLUSIONS: These findings suggest that serum levels of total IS were associated with AGEs levels, which may participate in the process of atherosclerosis.


Assuntos
Cresóis/sangue , Produtos Finais de Glicação Avançada/metabolismo , Indicã/sangue , Diálise Renal , Ésteres do Ácido Sulfúrico/sangue , Idoso , Biomarcadores , Creatinina/sangue , Estudos Transversais , Nefropatias Diabéticas/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Insuficiência Renal Crônica/etiologia , Insuficiência Renal Crônica/terapia , Insuficiência Renal Crônica/urina , Resultado do Tratamento
15.
World J Surg ; 38(11): 2838-44, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25002247

RESUMO

BACKGROUND: Aluminum overload and accumulation in tissues may lead to skeletal, hematological, and neurological toxicity. The aim of this study was to assess the effects of serum aluminum levels on presentations, postoperative recovery, and symptom improvement in patients undergoing parathyroidectomy for secondary hyperparathyroidism. METHODS: From 2008 to 2013, all patients with end-stage renal disease undergoing initial parathyroidectomy were included in the study. Serum aluminum level was measured preoperatively and/or within 1 week after surgery. Preoperative and postoperative biochemical profile and symptoms were compared between the low and high aluminum groups. RESULTS: A total of 176 patients were included in the study. Of these, 38 (22 %) patients had serum aluminum levels higher than 20 µg/L. A higher percentage of patients in the high aluminum group were on peritoneal dialysis than in the low aluminum group (24 vs. 4 %, p = 0.001). Both groups had similar bone mineral density and changes in biochemical profiles. The preoperative parathyroidectomy assessment of symptoms (PAS) score was not associated with serum aluminum levels (p = 0.349), whereas the postoperative PAS score showed positive association (p = 0.005). There was a negative association between serum aluminum levels and the improvement of total PAS scores (p = 0.001). The high aluminum group had more residual symptoms in three aspects: bone pain (p = 0.038), difficulty getting out of a chair or car (p = 0.045), and pruritus (p = 0.041). CONCLUSIONS: A high serum aluminum level was associated with reduced symptom improvement in patients undergoing parathyroidectomy for secondary hyperparathyroidism.


Assuntos
Alumínio/sangue , Hiperparatireoidismo Secundário/sangue , Hiperparatireoidismo Secundário/cirurgia , Adulto , Idoso , Densidade Óssea , Feminino , Humanos , Hiperparatireoidismo Secundário/etiologia , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Dor Musculoesquelética/sangue , Dor Musculoesquelética/etiologia , Paratireoidectomia , Diálise Peritoneal , Período Pós-Operatório , Prurido/sangue , Prurido/etiologia , Índice de Gravidade de Doença
16.
Ren Fail ; 36(6): 889-94, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24601755

RESUMO

The prognosis of critically ill patients with cirrhosis is poor. Our aim was to identify an objective variable that can improve the prognostic value of the Model of End-Stage Liver Disease (MELD) score in patients who have cirrhosis and are admitted to the intensive care unit (ICU). This retrospective cohort study included 177 patients who had liver cirrhosis and were admitted to the ICU. Data pertaining to arterial blood gas-related parameters and other variables were obtained on the day of ICU admission. The overall ICU mortality rate was 36.2%. The bicarbonate (HCO3) level was found to be an independent predictor of ICU mortality (odds ratio, 2.3; 95% confidence interval [CI], 1.0-4.8; p = 0.038). A new equation was constructed (MELD-Bicarbonate) by replacing total bilirubin by HCO3 in the original MELD score. The area under the receiver operating characteristic curve for predicting ICU mortality was 0.76 (95% CI, 0.69-0.84) for the MELD-Bicarbonate equation, 0.73 (95% CI, 0.65-0.81) for the MELD score, and 0.71 (95% CI, 0.63-0.80) for the Acute Physiology and Chronic Health Evaluation II score. Bicarbonate level assessment, as an objective and reproducible laboratory test, has significant predictive value in critically ill patients with cirrhosis. In contrast, the predictive value of total bilirubin is not as prominent in this setting. The MELD-Bicarbonate equation, which included three variables (international normalized ratio, creatinine level, and HCO3 level), showed better prognostic value than the original MELD score in critically ill patients with cirrhosis.


Assuntos
Bicarbonatos/sangue , Indicadores Básicos de Saúde , Unidades de Terapia Intensiva/estatística & dados numéricos , Cirrose Hepática/mortalidade , Índice de Gravidade de Doença , Biomarcadores/sangue , Feminino , Humanos , Cirrose Hepática/sangue , Cirrose Hepática/diagnóstico , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Prognóstico , Análise de Regressão , Estudos Retrospectivos , Taiwan/epidemiologia
18.
Kidney Res Clin Pract ; 43(4): 393-405, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38934040

RESUMO

Traditional acute kidney injury (AKI) classifications, which are centered around semi-anatomical lines, can no longer capture the complexity of AKI. By employing strategies to identify predictive and prognostic enrichment targets, experts could gain a deeper comprehension of AKI's pathophysiology, allowing for the development of treatment-specific targets and enhancing individualized care. Subphenotyping, which is enriched with AKI biomarkers, holds insights into distinct risk profiles and tailored treatment strategies that redefine AKI and contribute to improved clinical management. The utilization of biomarkers such as N-acetyl-ß-D-glucosaminidase, tissue inhibitor of metalloprotease-2·insulin-like growth factor-binding protein 7, kidney injury molecule-1, and liver fatty acid-binding protein garnered significant attention as a means to predict subclinical AKI. Novel biomarkers offer promise in predicting persistent AKI, with urinary motif chemokine ligand 14 displaying significant sensitivity and specificity. Furthermore, they serve as predictive markers for weaning patients from acute dialysis and offer valuable insights into distinct AKI subgroups. The proposed management of AKI, which is encapsulated in a structured flowchart, bridges the gap between research and clinical practice. It streamlines the utilization of biomarkers and subphenotyping, promising a future in which AKI is swiftly identified and managed with unprecedented precision. Incorporating kidney biomarkers into strategies for early AKI detection and the initiation of AKI care bundles has proven to be more effective than using care bundles without these novel biomarkers. This comprehensive approach represents a significant stride toward precision medicine, enabling the identification of high-risk subphenotypes in patients with AKI.

19.
Biomedicines ; 11(5)2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37238983

RESUMO

Studies have demonstrated that a low-protein diet supplemented with ketoanalogs (KAs) could significantly retard progression of renal function in patients with chronic kidney disease (CKD) stages 3-5. However, its effects on endothelial function and serum levels of protein-bound uremic toxins remain elusive. Therefore, this study explored whether a low-protein diet (LPD) supplemented with KAs affects kidney function, endothelial function, and serum uremic toxin levels in a CKD-based cohort. In this retrospective cohort, we enrolled 22 stable CKD stage 3b-4 patients on LPD (0.6-0.8 g/day). Patients were categorized into control (LPD only) and study groups (LPD + KAs 6 tab/day). Serum biochemistry, total/free indoxyl sulfate (TIS/FIS), total/free p-cresyl sulfate (TPCS/FPCS), and flow-mediated dilation (FMD) were measured before and after 6 months of KA supplementation. Before the trial, there were no significant differences in kidney function, FMD, or uremic toxin levels between the control and study groups. When compared with the control group, the paired t-test showed a significant decrease in TIS and FIS (all p < 0.05) and a significant increase in FMD, eGFR, and bicarbonate (all p < 0.05). In multivariate regression analysis, an increase in FMD (p < 0.001) and a decrease in FPCS (p = 0.012) and TIS (p < 0.001) remained persistent findings when adjusted for age, systolic blood pressure (SBP), sodium, albumin, and diastolic blood pressure (DBP). LPD supplemented with KAs significantly preserves kidney function and provides additional benefits on endothelial function and protein-bound uremic toxins in patients with CKD.

20.
Ann Acad Med Singap ; 52(8): 398-410, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-38920171

RESUMO

Introduction: Chronic kidney disease (CKD) is a condition defined as a persistent change in kidney structure or function, or both, that compromises human health. Environmental exposure to heavy metals (e.g. cadmium, lead, arsenic and mercury) is common, and high exposure levels are known to cause nephrotoxicity. Micronutrients such as selenium and zinc are positively associated with better kidney function and renal outcomes. This study determined the associations between CKD and heavy metal exposures measured in blood or urine within a community-dwelling population, and assessed whether and how selenium and zinc modified the associations. Method: Data were extracted from 4 cycles of the US National Health and Nutrition Examination Survey (NHANES) database (2011-2012, 2013-2014, 2015-2016 and 2017-2018). Results: Univariate analysis showed that higher quartiles of plasma lead and cadmium concentration were more likely associated with CKD than the lowest quartile, and along with folate, were linked to greater odds of CKD. Conversely, as plasma selenium and serum zinc increased, the odds of CKD decreased. Multivariate analysis had similar results after adjusting for relevant confounders. Higher plasma cadmium quartiles were associated with higher odds of CKD. Associations between higher quartiles of plasma selenium and serum zinc were significantly associated with lower odds of CKD. Conclusion: Elevated blood levels of heavy metals increase CKD, whereas elevated concentrations of plasma selenium and serum zinc decrease CKD. A high serum zinc concentration appears to interact with low-toxicity heavy metals to reduce CKD risk. This study suggests that increased selenium and zinc in the body along with avoidance of heavy metal exposures could protect against CKD.


Assuntos
Cádmio , Metais Pesados , Inquéritos Nutricionais , Insuficiência Renal Crônica , Selênio , Zinco , Humanos , Selênio/sangue , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/induzido quimicamente , Insuficiência Renal Crônica/etiologia , Zinco/sangue , Feminino , Masculino , Pessoa de Meia-Idade , Cádmio/sangue , Cádmio/efeitos adversos , Metais Pesados/sangue , Metais Pesados/efeitos adversos , Adulto , Chumbo/sangue , Exposição Ambiental/efeitos adversos , Estados Unidos/epidemiologia , Idoso , Mercúrio/sangue
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