Research Progress on Risk Factors and Intervention Measures for Prolonged Thrombocytopenia after Allogeneic Hematopoietic Stem Cell Transplantation --Review / 中国实验血液学杂志

Prolonged thrombocytopenia (PT) is a common complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT), with an incidence of about 5%-37%, which is closely related to the poor prognosis of patients. Previous studies have shown that transplantation type, CD34+ cell number, pretreatment regimen, acute graft-versus-host disease, virus infection, pre-transplantation serum ferritin level and donor specific antibodies can affect platelet implantation after transplantation. Identifying the risk factors of PT is helpful to early identify high-risk patients and take targeted preventive measures according to different risk factors to reduce the incidence of PT, reduce the risk of bleeding and improve the prognosis of patients. This article reviews the latest research progress of risk factors and intervention measures related to PT after allo-HSCT, in order to provide reference for the prevention and treatment of PT after transplantation.

Regulation of Mitochondria on Platelet Apoptosis and Activation / 中国实验血液学杂志

OBJECTIVE@#To explore the regulation of mitochondria on platelet apoptosis and activation, and the relationship between platelet apoptosis and activation.@*METHODS@#Platelets were isolated from peripheral venous blood of healthy volunteers. Cyclosporin A (CsA), which has a protective effect on the function of platelet mitochondria, BAPTA, which can chelate calcium ions across membranes in platelets, and NAC, an antioxidant that reduces the level of intracellular reactive oxygen species, were selected for coincubation with washed platelets, respectively. By flow cytometry, platelet aggregator was used to detect the changes of platelet mitochondrial function and platelet activation indexes after different interventions.@*RESULTS@#H89, staurosporine, and A23187 led to platelet mitochondrial abnormalities, while CsA could effectively reverse the decline of platelet mitochondrial membrane potential caused by them. Antioxidant NAC could reverse platelet mitochondrial damage correspondingly, and completely reverse platelet shrinkage and phosphatidylserine eversion induced by H89. BAPTA, prostaglandin E1, acetylsalicylic acid and other inhibitors could not reverse the decline of platelet mitochondrial membrane potential.@*CONCLUSION@#Mitochondrial function plays an important role in platelet apoptosis and activation. Abnormal mitochondrial function causes the imbalance of reduction/oxidation state in platelets, which leads to platelet apoptosis. Platelet apoptosis and activation are independent signal processes.

Study on Platelet Adhesion and Aggregation Induced by Gradient Shear Stress Using Microfluidic Chip Technology / 中国实验血液学杂志

OBJECTIVE@#To study the effect of gradient shear stress on platelet aggregation by microfluidic chip Technology.@*METHODS@#Microfluidic chip was used to simulate 80% fixed stenotic microchannel, and the hydrodynamic behavior of the stenotic microchannel model was analyzed by the finite element analysis module of sollidwork software. Microfluidic chip was used to analyze the adhesion and aggregation behavior of platelets in patients with different diseases, and flow cytometry was used to detect expression of the platelet activation marker CD62p. Aspirin, Tirofiban and protocatechuic acid were used to treat the blood, and the adhesion and aggregation of platelets were observed by fluorescence microscope.@*RESULTS@#The gradient fluid shear rate produced by the stenosis model of microfluidic chip could induce platelet aggregation, and the degree of platelet adhesion and aggregation increased with the increase of shear rate within a certain range of shear rate. The effect of platelet aggregation in patients with arterial thrombotic diseases were significantly higher than normal group (P<0.05), and the effect of platelet aggregation in patients with myelodysplastic disease was lower than normal group (P<0.05).@*CONCLUSION@#The microfluidic chip analysis technology can accurately analyze and evaluate the platelet adhesion and aggregation effects of various thrombotic diseases unde the environment of the shear rate, and is helpful for auxiliary diagnosis of clinical thrombotic diseases.

The Effect of Ena/VASP Family on the Expression of GPIb-IX Complex in Human Megakaryoblastic Leukemia Dami Cells / 中国实验血液学杂志

OBJECTIVE@#To explore the effects of Ena/VASP gene family on the expression of glycoprotein (GP) Ib-IX complex in human megakaryoblastic leukemia Dami cells.@*METHODS@#SiRNAs targeting Ena/VASP gene family were designed and synthesized to interfere Enah, EVL and VASP gene expression. When the siRNAs were transfected into Dami cells by using LipofectamineTM 2000 for 48 h, the expression of GPIb-IX complex was detected by quantitative real-time PCR, Western blot and flow cytometry.@*RESULTS@#We successfully established siVASP , siEVL and si Enah Dami cell lines. And it was found that the expression of GPIb-IX complex had no evident reduction in siEVL or siVASP Dami cells at both mRNA and protein level, while the total protein and membrane protein of GPIb-IX complex were obviously reduced when Enah was knocked down.@*CONCLUSION@#Enah could affect the expression of GPIb-IX complex in human megakaryoblastic leukemia Dami cells, but the underlying mechanism still needs to be further explored.

Molecular polymorphism Analysis on CD36 Deficiency among Platelet Blood Donors in Shenzhen / 中国实验血液学杂志

OBJECTIVE@#To analyze the molecular polymorphisms of CD36 among 58 blood donors with CD36 deficiency and compare with CD36 positive controls.@*METHODS@#A total of 58 donors with CD36 deficiency during a screening conducted in the laboratory from September 2019 to December 2020 were enrolled as the test group, including 39 males and 19 females, while 120 platelet donors with CD36 positive were randomly selected as the controls, including 76 males and 44 females. All of the subjects were Han nationality. The PCR-SBT method was used to detect coding region of CD36 gene, and molecular mutations were compared with those CD36 positive controls.@*RESULTS@#Among the 58 donors with CD36 deficiency, mutations appears in 32 individuals. The detection rate for type I was 71.43% (5/7), and type II was 51.92% (27/52), while among the 120 controls, mutations appears in 12 donors (10%). In the CD36 antigen-deficient donors, 16 variations were found, in which 329-330 del AC with the highest frequency accounted for 20.69%, followed by 1228-1239 del ATTGTGCCTATT(15.52%) and 1156 C>T(10.34%). Two variations, 198-205 del GATCTTTG and 220 C>T, led to premature termination of translation; four mutations, 329-330 del AC, 560 ins T, 1011-1049 39bp dupl and 1343-1344 ins TCTT, caused translation frame shift; 1228-1239 del ATTGTGCCTATT led to deletion of four amino acids (Ile-Val-Pro-Ile) at sites 410-413 of the peptide chain. The 1140 T>A and 1275 G>A were synonymous mutations, and the other 7 mutations resulted in the substitution of single nucleotide. The platelet expression in the donors of CD36 positive with 329-330 del AC or 1228-1239 del ATTGTGCCTATT mutation (heterozygote) was lower than those CD36 positive individuals without mutations (homozygote).@*CONCLUSION@#Multiple gene mutations in the CD36 coding region may cause CD36 deficiency, and the heterozygous individuals with mutations may lead to CD36 antigen reduction or deletion. Mutation is not detected in 44.83% of CD36 deficient individuals, there may be some other reasons for the CD36 antigen deficiency.

Analysis of Differential Proteins Related to Platelet Activation in Patients with Essential Thrombocythemia Based on Label-Free Quantitative Technology / 中国实验血液学杂志

OBJECTIVE@#To analysis the specific protein markers of essential thrombocythemia (ET) based on proteomics technology, to explore and verify the differential protein related to platelet activation.@*METHODS@#Blood samples were obtained from ET patients and healthy people and a certain protein mass spectrometry was detected using label-free quantitative technology. The proteins relative abundance increased or down-regulated by 1.3 times in the disease group compared with the control group, and the protein abundance in the two groups t test P＜0.05 were defined as differential proteins. Bioinformatics analysis of the differential proteins was performed using GO and KEGG. The difference in the average protein abundance between the two groups was analyzed by t test and P＜0.05 was considered statistically significant. Differential proteins were selected for verification by parallel reaction monitoring (PRM) technology.@*RESULTS@#A total of 140 differential proteins were found, of which 72 were up-regulated and 68 were down-regulated. KEGG enrichment showed that the differential protein expression was related to the platelet activation pathway. The differential proteins related to platelet activation were GPV, COL1A2, GP1bα, COL1A1 and GPVI. Among them, the expressions of GPV, GP1bα and GPVI were up-regulated, and the expressions of COL1A2 and COL1A1 were down-regulated. PRM verification of COL1A1, GP1bα, GPVI and GPV was consistent with LFP proteomics testing.@*CONCLUSION@#Differential proteins in ET patients are related to platelet activation pathway activation.Differential proteins such as GPV, GPVI, COL1A1 and GP1bα can be used as new targets related to ET platelet activation.

Sequencing and Proteomic Analysis of Exosomes from Apheresis Platelets in Different Storage Periods / 中国实验血液学杂志

OBJECTIVE@#To investigate the changes of gene sequencing and proteomics of apheresis platelet (AP) exosomes in different storage periods and predict the function of AP exosomes in different storage periods.@*METHODS@#Platelets at different storage periods of 0 day (D0), 3 day (D3) and 5 day (D5) were collected, exosomes were extracted with Gradient centrifugation; gene sequencing and proteomic analysis were used to analyze the exosomes, and biological functions of platelet exosomes were analyzed and predicted by bioinformatics. Liquid mass spectrometry (LMS) was used to detect the changes and function prediction of exosomes proteins. The small RNA sequencing library was prepared, and the constructed library was sequenced and bioinformatics technology was used for data analysis.@*RESULTS@#AP exosome iTRAQ protein analysis showed that AP exosomes stored in D3 with 55 up-regulated proteins and 94 down-regulated proteins (P<0.05, FC<0.83 or FC>1.2), while AP exosomes stored in D5 with 292 up-regulated proteins and 53 down-regulated proteins (P<0.05, FC<0.83 or FC>1.2) as compared with D0. KEGG pathway analysis showed that the proteins were mainly involved in transport and metabolism, immune system, cancer, membrane transport and other processes. There were statistically significant differences between AP exosome miRNAs in different storage days (P<0.01). The number of miRNA up-regulated and down-regulated was 374 and 255 as compared with the number of platelet exosomes miRNA stored in D3 and D0, while that was 297 and 242 in D5 and D0, and 252 and 327 in D5 and D3, respectively. The target genes of differential platelet exosome miRNAs were analyzed by GO enrichment. Target genes of differential miRNA were mainly involved in membrane composition, mainly played molecular functions binding to proteins, and participated in biological processes of transcriptional regulation.@*CONCLUSION@#The exosome differential proteins and miRNAs in D5 are significantly different from those in the D0 of APs, and they are involved in various biological processes.

Índices neutrófilo/linfocito, plaqueta/linfocito e inmunidad/inflamación sistémica en pacientes con neumonía por COVID-19 / Neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and systemic immune-inflammation index in patients with COVID-19-associated pneumonia

Resumen Introducción: Existen índices hematológicos que correlacionan la severidad y predicen la mortalidad, principalmente en estados sépticos y de inflamación. Objetivo: Correlacionar los índices neutrófilo/linfocito (INL), plaqueta/linfocito (IPL) e inmunidad/inflamación sistémica (IIIS) con la severidad de COVID-19. Método: Estudio descriptivo, analítico y retrospectivo de pacientes con neumonía por COVID-19, en quienes se analizaron INL, IPL e IIIS. Resultados: Se incluyeron 100 pacientes, 54 hombres y 46 mujeres, con una media de 49.4 ± 19.3 años. Las medias de INL, IPL e IIIS fueron 10.7 ± 10.9, 290.1 ± 229.2 y 2.6 ± 3.4 × 109, respectivamente. En 54 %, la neumonía fue leve y en 46 %, grave. En cuanto a los desenlaces hospitalarios, 75 % egresó por mejoría y 25 % falleció. Las medias de INL, IPL e IIIS de los pacientes que fallecieron versus las de los pacientes que mejoraron fueron 20.4 ± 16.9 versus 7.5 ± 4.9 (p = 0.001), 417.1 ± 379.7 versus 247.7 ± 127.4 (p = 0.038) y 4.8 ± 6.1 versus 1.9 ± 1.2 × 109 (p = 0.030), respectivamente. Conclusión: Los índices hematológicos en pacientes con neumonía por COVID-19 pueden ser empleados como predictores de severidad y pronóstico.

Abstract Introduction: There are hematological parameters that correlate severity and predict mortality mainly in septic and inflammatory states. Objective: To correlate the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and systemic immune-inflammation index (SII) with COVID-19 severity. Method: Descriptive, analytical, retrospective study of patients with COVID-19 pneumonia, in which NLR, PLR and SII were analyzed. Results: One-hundred patients were included, 54 men and 46 women, with a mean age of 49.4 ± 19.3 years. NLR, PLR and SII means were 10.7 ± 10.9, 290.1 ± 229.2, and 2.6 ± 3.4 × 109, respectively. In 54 %, pneumonia was mild, and in 46 %, severe. Regarding hospital outcomes, 75 % were discharged due to improvement and 25 % died. NLR, PLR and SII means of the patients who died versus the patients who improved were 20.4 ± 16.9 versus 7.5 ± 4.9 (p = 0.001), 417.1 ± 379.7 versus 247.7 ± 127.4 (p = 0.038) and 4.8 ± 6.1 versus 1.9 ± 1.2 × 109 (p = 0.030), respectively. Conclusion: Hematological parameters can be used in patients with COVID-19-associated pneumonia as predictors of severity and prognosis.

High Residual Platelet Reactivity during Aspirin Therapy in Patients with Non-St Segment Elevation Acute Coronary Syndrome: Comparison Between Initial and Late Phases / Alta Atividade Plaquetária Residual em Resposta ao Ácido Acetilsalicílico na Síndrome Coronariana Aguda Sem Supra de ST: Comparação entre as Fases Aguda e Tardia

Abstract Background: High platelet reactivity (HPR) during therapy with acetylsalicylic acid (ASA) is a poor prognostic factor in acute coronary syndromes (ACS). The prevalence of HPR during ACS is greater than that reported in stable diseases. However, it is unclear whether this prevalence of HPR is a transient phenomenon or a characteristic of this high-risk population. Objective: The main objective is to compare the effects of ASA on platelet function in the initial and late phases of ACS in a single population. Secondary objectives are: correlation between the tests between themselves and the relationship between the tests and the variation of the inflammatory markers (C-reactive protein and interleukin-6). Methods: Seventy patients with non-ST segment elevation (NSTE) ACS in use of 100-200 mg of ASA per day for at least 7 days were prospectively studied. Platelet function was assessed in the first 48 hours and subsequently after 3 months using four methods: VerifyNow™ (VFN), whole blood platelet aggregation (WBPA) with arachidonic acid (AA) and collagen as agonists, and platelet function analyzer (PFA). The level of statistical significance considered was < 0.05. Results: According to the more specific methods (WBPA with AA and VFN), the incidence of HPR was significantly higher in the early phase than in the late phase: WBPA with AA: 31% versus 13%, p = 0.015; VFN: 32% versus 16%, p = 0.049. The other methods tested, which were less specific for ASA, did not show significant differences between phases. The correlation between the methods was weak or moderate (r ranging from 0.3 to 0.5, p < 0.05), and there were no significant associations between HPR and inflammatory markers. Conclusion: The prevalence of HPR during AAS therapy, assessed by specific methods for cyclooxygenase 1 (COX-1), is higher during the acute phase than in the late phase of NSTE ACS.

Resumo Fundamento: A alta atividade plaquetária (AAP) durante a terapia com ácido acetilsalicílico (AAS) é fator de mau prognóstico nas síndromes coronarianas agudas (SCA). A prevalência de AAP durante a SCA é maior do que a relatada na doença estável. No entanto, não está claro se esta prevalência de AAP é um fenômeno transitório ou característica dessa população de alto risco. Objetivo: O objetivo principal é comparar, em uma mesma população, os efeitos do AAS sobre a função plaquetária nas fases inicial e tardia da SCA. Os objetivos secundários são: correlação entre os testes entre si e a relação entre os testes e a variação dos marcadores inflamatórios (proteína C reativa e interleucina-6). Métodos: Foram estudados prospectivamente 70 pacientes com SCA sem elevação de ST (SCSST) em uso de 100 a 200 mg de AAS por dia por pelo menos 7 dias. A função plaquetária foi avaliada nas primeiras 48 horas e 3 meses após por quatro métodos: VerifyNow™ (VFN), agregometria de sangue total (AST) com ácido araquidônico (AA) e colágeno como agonistas, e analisador de função plaquetária (PFA). O nível de significância estatístico considerado foi < 0,05. Resultados: A média de idade foi de 65 ±9,7 anos e 54% da população eram do sexo feminino. De acordo com os métodos mais específicos (AST com AA e VFN), a incidência de AAP foi significativamente maior na fase inicial, em relação à tardia: AST com AA 31% versus 13%, p = 0,015; VFN 32% versus 16%, p = 0,049. Os outros métodos testados, menos específicos para o AAS, não mostraram diferenças significativas entre as fases. A correlação entre os métodos foi fraca ou moderada (r variando de 0,3 a 0,5, p < 0,05), e não houve associações significativas entre AAP e marcadores inflamatórios. Conclusão: A prevalência de AAP durante a terapia com AAS, avaliada por métodos específicos para cicloxigenase 1 (COX-1), é maior durante a fase aguda do que na tardia da SCASST.

Efecto del 27- hidroxicolesterol en la acción antiplaquetaria de estradiol en mujeres postmenopáusicas / 27- Hydroxycholesterol reverses estradiol induced inhibition of platelet aggregation in postmenopausal women

Background: The decline of estrogen levels increases cardiovascular risk in women. Platelets express estrogen receptors and 17β-estradiol- (E2) can produce a protective effect on thrombus formation. The hydroxylation of cholesterol generates several sterols and 27-hydroxycholesterol (27HC) predominates in circulation. Aim: To evaluate the effect of 27HC as an endogenous antagonist of the anti-aggregating properties of E2 in platelets of postmenopausal women. Material and Methods: Platelet function of postmenopausal women was evaluated ex-vivo. Platelets pre-incubated with 27HC in the presence or absence of E2, were stimulated with collagen. Aggregation was evaluated using turbidimetry using a Chrono-log aggregometer. Results: Collagen-stimulated platelet aggregation was significantly inhibited by E2. The inhibitory effect of E2 on collagen-stimulated platelet aggregation was significantly reversed in the presence of 27HC. Conclusions: The suppressive effect of E2 on platelet aggregation is inhibited by 27HC, which could contribute to increase cardiovascular risk in postmenopausal women.

Cell Therapy for Wound Healing

In covering wounds, efforts should include utilization of the safest and least invasive methods with goals of achieving optimal functional and cosmetic outcome. The recent development of advanced wound healing technology has triggered the use of cells to improve wound healing conditions. The purpose of this review is to provide information on clinically available cell-based treatment options for healing of acute and chronic wounds. Compared with a variety of conventional methods, such as skin grafts and local flaps, the cell therapy technique is simple, less time-consuming, and reduces the surgical burden for patients in the repair of acute wounds. Cell therapy has also been developed for chronic wound healing. By transplanting cells with an excellent wound healing capacity profile to chronic wounds, in which wound healing cannot be achieved successfully, attempts are made to convert the wound bed into the environment where maximum wound healing can be achieved. Fibroblasts, keratinocytes, adipose-derived stromal vascular fraction cells, bone marrow stem cells, and platelets have been used for wound healing in clinical practice. Some formulations are commercially available. To establish the cell therapy as a standard treatment, however, further research is needed.

Implication of Early Lymphocyte Recovery after Allogeneic Hematopoietic Stem Cell Transplantation in Children with Leukemia

PURPOSE: The repopulating lymphocytes after allogeneic hematopoietic stem cell transplantation have an important role not only on the prevention of serious infections in the early transplantation period, but also on the killing of residual leukemic cells by graft-versus-leukemia effect. The aim of this study was to analyze the impact of lymphocyte recovery after allogeneic stem cell transplantation in children with hematologic malignancies. MATERIALS AND METHODS: We evaluated 69 children transplanted for acute lymphoblastic leukemia (ALL) (n=34), acute myeloid leukemia (AML) (n=26), chronic leukemia (n=7) and juvenile myelomonocytic leukemia (n=2) between 1996 and 2008 at the Chonnam National University Hospital, Korea. The patients were grouped based on absolute lymphocyte counts (ALC) or =500/microL at D+21 and D+30 after transplant. RESULTS: Patients with a High ALC at D+21 and D+30 had a faster neutrophil and platelet engraftment. The High at D+30 group had a better 5 year overall survival (71% vs. 53%, p=0.043) and event-free survival (72% vs. 53%, p=0.065) than the Low at D+30 group. The incidence of grade II-IV acute and chronic graft-versus-host disease (GVHD), and relapse rate did not differ by the ALC counts. However, the Low at D+30 group had a significantly increased risk for transplant-related mortality (p=0.019). The univariate analysis showed that the factors associated with decreased survival were a Low ALC at D+30, patients with high risk ALL, and grade II-IV aGVHD in patients with ALL and AML. CONCLUSION: Early posttransplant serial lymphocyte measurement would be a simple but useful method for predicting transplant outcomes.

Flow Cytometric Human Leukocyte Antigen-B27 Typing with Stored Samples for Batch Testing

BACKGROUND: Flow cytometry (FC) HLA-B27 typing is still used extensively for the diagnosis of spondyloarthropathies. If patient blood samples are stored for a prolonged duration, this testing can be performed in a batch manner, and in-house cellular controls could easily be procured. In this study, we investigated various methods of storing patient blood samples. METHODS: We compared four storage methods: three methods of analyzing lymphocytes (whole blood stored at room temperature, frozen mononuclear cells, and frozen white blood cells [WBCs] after lysing red blood cells [RBCs]), and one method using frozen platelets (FPLT). We used three ratios associated with mean fluorescence intensities (MFI) for HLAB27 assignment: the B27 MFI ratio (sample/control) for HLA-B27 fluorescein-5-isothiocyanate (FITC); the B7 MFI ratio for HLA-B7 phycoerythrin (PE); and the ratio of these two ratios, B7/B27 ratio. RESULTS: Comparing the B27 MFI ratios of each storage method for the HLA-B27+ samples and the B7/B27 ratios for the HLA-B7+ samples revealed that FPLT was the best of the four methods. FPLT had a sensitivity of 100% and a specificity of 99.3% for HLA-B27 assignment in DNA-typed samples (N=164) when the two criteria, namely, B27 MFI ratio >4.0 and B7/B27 ratio <1.5, were used. CONCLUSIONS: The FPLT method was found to offer a simple, economical, and accurate method of FC HLA-B27 typing by using stored patient samples. If stored samples are used, this method has the potential to replace the standard FC typing method when used in combination with a complementary DNA-based method.

Flow Cytometric Human Leukocyte Antigen-B27 Typing with Stored Samples for Batch Testing

BACKGROUND: Flow cytometry (FC) HLA-B27 typing is still used extensively for the diagnosis of spondyloarthropathies. If patient blood samples are stored for a prolonged duration, this testing can be performed in a batch manner, and in-house cellular controls could easily be procured. In this study, we investigated various methods of storing patient blood samples. METHODS: We compared four storage methods: three methods of analyzing lymphocytes (whole blood stored at room temperature, frozen mononuclear cells, and frozen white blood cells [WBCs] after lysing red blood cells [RBCs]), and one method using frozen platelets (FPLT). We used three ratios associated with mean fluorescence intensities (MFI) for HLAB27 assignment: the B27 MFI ratio (sample/control) for HLA-B27 fluorescein-5-isothiocyanate (FITC); the B7 MFI ratio for HLA-B7 phycoerythrin (PE); and the ratio of these two ratios, B7/B27 ratio. RESULTS: Comparing the B27 MFI ratios of each storage method for the HLA-B27+ samples and the B7/B27 ratios for the HLA-B7+ samples revealed that FPLT was the best of the four methods. FPLT had a sensitivity of 100% and a specificity of 99.3% for HLA-B27 assignment in DNA-typed samples (N=164) when the two criteria, namely, B27 MFI ratio >4.0 and B7/B27 ratio <1.5, were used. CONCLUSIONS: The FPLT method was found to offer a simple, economical, and accurate method of FC HLA-B27 typing by using stored patient samples. If stored samples are used, this method has the potential to replace the standard FC typing method when used in combination with a complementary DNA-based method.

Efeitos do tratamento periodontal não-cirúrgico na via L-arginina-óxido nítrico e no estresse oxidativo em plaquetas / Effects of nonsurgical periodontal treatment on L-arginine-nitric oxide pathway and oxidant status in platelets

Estudos publicados nas duas últimas décadas sugerem um aumento do risco de doença cardiovascular (DCV) em pacientes com periodontite, mas os mecanismos fisiopatológicos dessa associação ainda não estão completamente esclarecidos. Uma vez que foi demonstrado aumento da ativação plaquetária e do estresse oxidativo na periodontite, o objetivo do presente estudo foi investigar a via L-arginina-óxido nítrico (NO)- guanosina monofosfato cíclica (GMPc) e parâmetros de estresse oxidativo em plaquetas de pacientes com periodontite, bem como avaliar o efeito do tratamento periodontal não-cirúrgico nessas variáveis. Um total de 10 pacientes sem periodontite (periodontalmente saudáveis ou com gengivite) e 10 pacientes com periodontite participaram do estudo. A avaliação clínica, laboratorial e experimental foi realizada no início do estudo e 90 dias após realização da terapia periodontal básica (grupo periodontite). A avaliação clínica periodontal incluiu registros de: profundidade de bolsa à sondagem (PBS), nível de inserção (NIC), percentual de placa e percentual de sangramento à sondagem. Os seguintes experimentos foram realizados: influxo de L-arginina; atividade e expressão das enzimas óxido nítrico sintase e da arginase; expressão das enzimas guanilato ciclase solúvel e fosfodiesterase 5; determinação dos níveis intraplaquetários de GMPc; agregação plaquetária; avaliação do estresse oxidativo (atividade oxidante total, atividade das enzimas antioxidantes catalase e da superóxido dismutase - SOD); medição dos níveis de proteína C reativa (CRP) e de fibrinogênio. Os resultados obtidos no início do estudo demonstraram ativação do influxo de L-arginina em plaquetas via sistema y+L nos pacientes com periodontite, bem como concentrações intraplaquetárias de GMPc diminuídas e aumento sistêmico da CRP. Após o tratamento periodontal, observou-se redução do percentual de sítios com PBS ≥ 6 mm, NIC 4-5 mm e NIC ≥ 6 mm, aumento nos níveis de GMPc, para níveis ...

Studies published over the last two decades have suggested an increase of cardiovascular disease (CVD) risk on periodontitis patients, but the physiopathological mechanisms involved in this association are not yet clear. Since it has been demonstrated an enhancement on both platelet activation and oxidative stress on periodontitis patients, the aim of this study was to investigate the L-arginine-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway on platelets from periodontitis patients, and the effect of non-surgical periodontal treatment in these variables. A total of 10 patients without periodontitis (periodontal healthy controls or gingivitis patients) and 10 periodontitis patients were included in this study. The clinical, laboratorial, and experimental evaluations were performed at the beginning of the study and 90 days after the basic periodontal therapy (periodontitis group). The clinical periodontal evaluation included the measurements of probing pocket depth (PPD), clinical attachment level (CAL), plaque percentage, and percentage of bleeding on probing. The following experiments were performed: L-arginine influx; nitric oxide synthase and arginase enzymes activity and expression; expression of guanylate cyclase and phosphodiesterase-5 enzymes; measurement of intraplatelet cGMP levels; platelet aggregation; oxidative stress evaluation (total oxidant activity and activity of both antioxidant enzymes catalase and superoxide dismutase – SOD); measurement of C reactive protein (CRP) and fibrinogen. The initial results demonstrated an activation of L-arginine influx in platelets from periodontitis patients via y+L system, reduced intraplatelet cGMP levels and increased CRP. After periodontal treatment, it was observed reduction on percentage of sites with PPD ≥ 6 mm, CAL 4-5 mm and CAL ≥ 6 mm, enhancement on cGMP levels, to levels comparables to patients without periodontitis, accompanied by a higher activity of both antioxidant ...(AU)

A via L-arginina-óxido nítrico, estresse oxidativo e ciclo da uéia na obesidade / L-arginine-nitric oxide pathway, oxidative stress and urea cycle in obesity

A obesidade é um distúrbio metabólico de etiologia multifatorial e elevada prevalência no Brasil, que pode ser definida por um índice de massa corporal (peso em quilogramas dividido pela altura em metros ao quadrado) maior ou igual a 30 kg/m2, e que está associada de forma independente a um elevado risco de morbidade e mortalidade cardiovascular devido aos eventos aterotrombóticos. O óxido nítrico (NO), uma pequena molécula gasosa, é produzido através da conversão do aminoácido catiônico L-arginina em L-citrulina e NO em uma reação catalisada por uma família de enzimas denominadas NO-sintases (NOS), e funciona como um protetor cardiovascular modulando por exemplo o relaxamento do músculo liso vascular e a função plaquetária. O objetivo desta tese foi avaliar a via L-arginina-NO, bem como investigar a função plaquetária, o estresse oxidativo, e a atividade da arginase em pacientes com obesidade. O transporte de L-arginina, a produção de guanosina monofosfato cíclica (GMPc), a atividade e a expressão das isoformas da NOS (iNOS e eNOS), a atividade da arginase, o estresse oxidativo (produção de espécies reativas de oxigênio – EROs; atividade da superóxido dismutase – SOD; e atividade da catalase), bem como a função plaquetária foram medidos nas plaquetas dos pacientes com obesidade. Nas hemácias, foram medidos o transporte de L-arginina e a atividade da NOS e da arginase. Os níveis de aminoácidos e de marcadores inflamatórios (fibrinogênio e proteína C reativa) também foram medidos sistemicamente. Os resultados demonstram que o influxo de L-arginina via sistema y+L, a atividade da NOS e a produção de GMPc estão diminuídos nas plaquetas dos pacientes obesos em relação aos controles saudáveis, enquanto que não houve diferença na atividade da arginase. Além disso, a expressão das isoformas da NOS bem como a agregação plaquetária em plaquetas de pacientes com obesidade mostrou-se aumentada em relação aos controles. Nas hemácias destes pacientes, observou-se...

Obesity is a metabolic disorder of multifactorial etiology and high prevalence in Brazil, which can be defined as a body mass index (weight in kilograms divided by height in square meters) greater than or equal to 30 kg/m2, and that is independently associated with a high risk of cardiovascular morbidity and mortality due to atherothrombotic events. Nitric oxide (NO), a small gaseous molecule, is produced through the conversion of the cationic amino acid L-arginine to L-citrulline and NO in a reaction catalyzed by a family of enzymes called NO synthases (NOS) and it acts as a cardiovascular protector modulating, for example, the relaxation of vascular smooth muscle and the platelet function. The aim of this thesis was to assess the L-arginine-NO pathway, as well as to investigate platelet function, oxidative stress, and the arginase activity in patients with obesity. The L-arginine transport, the production of cyclic guanosine monophosphate (cGMP), the activity and expression of NOS isoforms (eNOS and iNOS), the arginase activity, oxidative stress (production of reactive oxygen species - ROS; superoxide dismutase activity - SOD, and catalase activity), and platelet function were evaluated in platelets from patients with obesity. In erythrocytes, the L-arginine transport and the activity of NOS and arginase were investigated. Systemic levels of amino acids and inflammatory markers (fibrinogen and C-reactive protein) were also investigated. The results demonstrated that L-arginine influx via y+L system, NOS activity, and cGMP levels were decreased in platelets from obese subjects compared to healthy controls, whereas no difference was observed in arginase activity. In addition, the expression of NOS isoforms and platelet aggregation in platelets from patients with obesity was increased in relation to controls. In erythrocytes from these patients, there were a higher influx of L-arginine via y+ and y+L system, and NOS activity, and no difference in arginase...

Efeitos do tratamento periodontal não-cirúrgico na via L-arginina-óxido nítrico e no estresse oxidativo em plaquetas / Effects of nonsurgical periodontal treatment on L-arginine-nitric oxide pathway and oxidant status in platelets

Estudos publicados nas duas últimas décadas sugerem um aumento do risco de doença cardiovascular (DCV) em pacientes com periodontite, mas os mecanismos fisiopatológicos dessa associação ainda não estão completamente esclarecidos. Uma vez que foi demonstrado aumento da ativação plaquetária e do estresse oxidativo na periodontite, o objetivo do presente estudo foi investigar a via L-arginina-óxido nítrico (NO)- guanosina monofosfato cíclica (GMPc) e parâmetros de estresse oxidativo em plaquetas de pacientes com periodontite, bem como avaliar o efeito do tratamento periodontal não-cirúrgico nessas variáveis. Um total de 10 pacientes sem periodontite (periodontalmente saudáveis ou com gengivite) e 10 pacientes com periodontite participaram do estudo. A avaliação clínica, laboratorial e experimental foi realizada no início do estudo e 90 dias após realização da terapia periodontal básica (grupo periodontite). A avaliação clínica periodontal incluiu registros de: profundidade de bolsa à sondagem (PBS), nível de inserção (NIC), percentual de placa e percentual de sangramento à sondagem. Os seguintes experimentos foram realizados: influxo de L-arginina; atividade e expressão das enzimas óxido nítrico sintase e da arginase; expressão das enzimas guanilato ciclase solúvel e fosfodiesterase 5; determinação dos níveis intraplaquetários de GMPc; agregação plaquetária; avaliação do estresse oxidativo (atividade oxidante total, atividade das enzimas antioxidantes catalase e da superóxido dismutase - SOD); medição dos níveis de proteína C reativa (CRP) e de fibrinogênio. Os resultados obtidos no início do estudo demonstraram ativação do influxo de L-arginina em plaquetas via sistema y+L nos pacientes com periodontite, bem como concentrações intraplaquetárias de GMPc diminuídas e aumento sistêmico da CRP. Após o tratamento periodontal, observou-se redução do percentual de sítios com PBS ≥ 6 mm, NIC 4-5 mm e NIC ≥ 6 mm, aumento nos níveis de GMPc, para níveis ...

Studies published over the last two decades have suggested an increase of cardiovascular disease (CVD) risk on periodontitis patients, but the physiopathological mechanisms involved in this association are not yet clear. Since it has been demonstrated an enhancement on both platelet activation and oxidative stress on periodontitis patients, the aim of this study was to investigate the L-arginine-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway on platelets from periodontitis patients, and the effect of non-surgical periodontal treatment in these variables. A total of 10 patients without periodontitis (periodontal healthy controls or gingivitis patients) and 10 periodontitis patients were included in this study. The clinical, laboratorial, and experimental evaluations were performed at the beginning of the study and 90 days after the basic periodontal therapy (periodontitis group). The clinical periodontal evaluation included the measurements of probing pocket depth (PPD), clinical attachment level (CAL), plaque percentage, and percentage of bleeding on probing. The following experiments were performed: L-arginine influx; nitric oxide synthase and arginase enzymes activity and expression; expression of guanylate cyclase and phosphodiesterase-5 enzymes; measurement of intraplatelet cGMP levels; platelet aggregation; oxidative stress evaluation (total oxidant activity and activity of both antioxidant enzymes catalase and superoxide dismutase – SOD); measurement of C reactive protein (CRP) and fibrinogen. The initial results demonstrated an activation of L-arginine influx in platelets from periodontitis patients via y+L system, reduced intraplatelet cGMP levels and increased CRP. After periodontal treatment, it was observed reduction on percentage of sites with PPD ≥ 6 mm, CAL 4-5 mm and CAL ≥ 6 mm, enhancement on cGMP levels, to levels comparables to patients without periodontitis, accompanied by a higher activity of both antioxidant ...

Mecanismos moleculares e celulares envolvidos na modulação da via L-arginina-óxido nítrico em hipertensão e insuficiência renal crônica / Molecular and cellular mechanisms involved in modulation of L-arginine-nitric oxide in hypertension and chronic renal failure

A Insuficiência renal crônica (IRC) e a hipertensão arterial sistêmica (HAS) são patologias com alta morbidade e mortalidade, consumindo grandes verbas de saúde pública. A disfunção endotelial presente tanto na IRC, como na hipertensão, contribui para a manutenção de elevada resistência periférica, favorecendo complicações como a aterosclerose. Esta disfunção endotelial é parte de um estado pró-trombótico, levando à ocorrência de eventos cardiovasculares, principal causa de morte nestas patologias. O óxido nítrico (NO) tem um papel importante na modulação da atividade plaquetária. Anormalidades na síntese e/ou inativação do NO são descritas tanto na insuficiência renal crônica como na hipertensão. Estudos prévios demonstraram uma redução do influxo de L-arginina em eritrócitos e plaquetas de pacientes hipertensos e em um modelo animal de hipertensão. Além disso, em IRC, nosso grupo mostrou uma ativação da via L-arginina-NO em plaquetas. O objetivo dessa tese é avaliar a via L-arginina-NO na HAS e em diferentes estágios de IRC, bem como investigar o ciclo da uréia, e a presença de marcadores de estresse nesses pacientes. De acordo com o presente estudo pôde-se verificar que não houve alteração na síntese de NO em eritrócitos na hipertensão, todavia ocorre uma ativação do ciclo da uréia, que pode ser dada pelo aumento do influxo de L-arginina eritrocitário previamente demonstrado. Não foi demonstrada diferença significativa na peroxidação lipídica sistêmica, em plaquetas ou eritrócitos na HAS. Em plaquetas, no entanto, houve uma redução da atividade da NO sintase (NOS), que não foi acompanhada por alteração da expressão das isoformas da NOS, da arginase, da fosfodiesterase 5 (PDE5) ou da guanilato ciclase (GC) solúvel. Essa redução na síntese de NO em plaquetas pode ser explicada por um menor influxo de L-arginina que está presente na hipertensão. Os eritrócitos de pacientes renais crônicos em hemodiálise mostraram um maior influxo de L-arginina...

Chronic renal failure (CRF) and essential hypertension (EH) are diseases associated with high rates of morbidity and mortality, consuming huge amounts of money from the public health system. The endothelial dysfunction existent in both diseases, CRF and EH, contributes to the maintenance of the high peripheral resistance, and contribute to circulatory complications such as atherosclerosis. This endothelial dysfunction is part of a pro-thrombotic state, leading to cardiovascular events, which are the major cause of death in these disorders. Nitric oxide (NO) plays an important role in the modulation of platelet function. Abnormalities of NO synthesis or inactivation are described in CRF and EH. It was previously reported an inhibition of L-arginine transport in erythrocytes of hypertensive patients and in an animal model of hypertension. Moreover, we have also demonstrated an activation of L-arginine-NO pathway in platelets taken from uraemic patients. The aim of the present thesis is to investigate L-arginine-NO pathway in arterial hypertension and in different stages of chronic renal failure. It will also be evaluated urea cycle and the presence of oxidative stress markers in these patients. According to the present study it was not detected any alteration in erythrocytes NO synthesis in hypertension, however, there was an activation of urea cycle, which could be explained by an increase in L-arginine influx. The present study has not demonstrated significative difference in markers of lipid peroxidation in the serum, platelets or erythrocytes in hypertension. In platelets however, there was an inhibition of NO synthase (NOS) activity without any alterations of NOS isoforms, arginase, phosphodiesterase 5 (PDE5) or soluble guanylyl cyclase (sGC) expression. This reduction of NO synthesis may be explained by a lower influx of L-arginine that is present on hypertension. Erythrocytes from chronic renal failure patients under haemodyalysis...