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The paper discusses the problem of detecting emission sources in a low buildings area using unmanned aerial vehicles. The problem was analyzed, and methods of solving it were presented. Various data acquisition scenarios and their impact on the feasibility of the task were analyzed. A method for detecting smoke objects over buildings using stationary video sequences acquired with a drone in hover with the camera in the nadir position is proposed. The method uses differential frame information from stabilized video sequences and the YOLOv7 classifier. A convolutional network classifier was used to detect the roofs of buildings, using a custom training set adapted to the type of data used. Such a solution, although quite effective, is not very practical for the end user, but it enables the automatic generation of a comprehensive training set for classifiers based on deep neural networks. The effectiveness of such a solution was tested for the latest version of the YOLOv7 classifier. The tests proved the effectiveness of the described method, both for single images and video sequences. In addition, the obtained classifier correctly recognizes objects for sequences that do not meet some of the initial assumptions, such as the angle of the camera capturing the image.
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Most modern color digital cameras are equipped with a single image sensor with a color filter array (CFA). One of the most important stages of preprocessing is noise reduction. Most research related to this topic ignores the problem associated with the actual color image acquisition process and assumes that we are processing the image in the sRGB space. In the presented paper, the real process of developing raw images obtained from the CFA sensor was analyzed. As part of the work, a diverse database of test images in the form of a digital negative and its reference version was prepared. The main problem posed in the work was the location of the denoising and demosaicing algorithms in the entire raw image processing pipeline. For this purpose, all stages of processing the digital negative are reproduced. The process of noise generation in the image sensors was also simulated, parameterizing it with ISO sensitivity for a specific CMOS sensor. In this work, we tested commonly used algorithms based on the idea of non-local means, such as NLM or BM3D, in combination with various techniques of interpolation of CFA sensor data. Our experiments have shown that the use of noise reduction methods directly on the raw sensor data, improves the final result only in the case of highly disturbed images, which corresponds to the process of image acquisition in difficult lighting conditions.
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The agricultural use of peatlands, the stabilization of the substrate for building or road construction or for increasing the capacity of soil to support heavy machinery for industrial activities (peat and petroleum extraction), harvesting to provide peat for energy, and the growing media and initiation of chemical processes must be preceded by drainage. As a consequence of drainage, peat underwent an irreversible conversion into moorsh (secondary transformation of the peat). The object of the study was to investigate comparatively the organic matter composition and molecular structure of humic acids (HAs) in the raised bog, fen, and peat-moorsh soils developed in various compositions of botanical cover, peat-forming species, and oxic and anoxic conditions as a result of the oscillation of ground water during drainage as well as to evaluate the vulnerability of soil organic matter (SOM) to decomposition. Drainage was shown to be the principal factor causing the various chemical compositions and physicochemical properties of HAs. Large and significant differences in chemical composition of peat and the properties of HAs were found to be related to the degree of decomposition. The HAs from drained peatlands were less chemically mature. In contrast, the HAs from fen and raised bog were found to be more mature than that of the corresponding drained peatlands. The above findings showed the distinguishable structure of HAs within the soil profile created by the plant residue biodegradation and formed in both oxic and anoxic conditions. The analytical methods of thermal analysis together with the optical densities and paramagnetic behaviour are suitable and effective tools for studying structure-property relationships characterizing the origin and formation process of HAs in various environmental conditions.
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Água Subterrânea/química , Substâncias Húmicas/análise , Solo/química , Agricultura , Áreas AlagadasRESUMO
UNLABELLED: Neutrophil gelatinase-associated lipocalin (NGAL) is one of the most extensively examined biological markers for early prediction of acute kidney injury, but there is a lack of data on normal NGAL values in healthy term-born infants. This encouraged us to established serum and urine levels using samples collected from 38 girls and 50 boys, born at a median age of 39 weeks, during the first 48 hours after birth. CONCLUSION: Our findings showed that urine NGAL, but not serum levels, were significantly higher in girls than in boys.
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Recém-Nascido/urina , Lipocalina-2/urina , Caracteres Sexuais , Feminino , Humanos , Recém-Nascido/sangue , Lipocalina-2/sangue , Masculino , Estudos ProspectivosRESUMO
Introduction: Chronic kidney disease and end-stage renal disease have been found to be caused by diabetes. More recently, the renal tubulointerstitium has been increasingly assumed to play a role in the pathogenesis of diabetic nephropathy with prolonged exposure to a variety of metabolic and haemodynamic injuring factors associated with sustained hyperglycaemia as contributing factors. This study aimed to investigate whether maternal diabetes could be the factor affecting kidney function in a newborn with the use of neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) - biomarkers of renal injury. Material and methods: The study included 138 full-term newborns: 50 newborns from diabetic pregnancies and 88 healthy newborns. The concentrations of NGAL and KIM-1 were determined in urine in the first or the second day of life with a commercially available ELISA kit. Results: Considerably higher urine level of NGAL (25.7 (11.8-40.8)) and NGAL/cr. (29.1 (19.1-47.4)) in babies from diabetic pregnancies has been found when compared to the reference group (16.74 (9.9-27.5)) and (21.9 (14.6-29.8)) (p = 0.01, p < 0.01) respectively. We also found a significantly higher urine level of NGAL (27.8 (13.6-44.2)), NGAL/cr. (31.9 (17.6-57.4)), and KIM-1/cr. (2.6 (1.6-5.5)) in babies of diabetic mothers treated with insulin when compared to the reference group (16.7 (9.9-27.5)), (21.9 (14.6-29.8)), (1.9 (0.8-3.2)), (p = 0.01, p = 0.02, p = 0.02), respectively. Conclusions: Based on the results of this study, we indicate for the first time that maternal diabetes mellitus during pregnancy may be considered as the cause of tubular kidney damage in newborns.
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Calcification of vessels reduces their elasticity, affecting hemodynamic parameters of the cardiovascular system. The development of arterial hypertension, cardiac hypertrophy, ischemic heart disease or peripheral arterial disease significantly increases mortality in patients over 60 years of age. Stage of advancement and the extent of accumulation of calcium deposits in vessel walls are key risk factors of ischemic events. Vascular calcification is an active and complex process that involves numerous mechanisms responsible for calcium depositions in arterial walls. They lead to increase in arterial stiffness and in pulse wave velocity, which in turn increases cardiovascular disease morbidity and mortality. In-depth study and thorough understanding of vascular calcification mechanisms may be crucial for establishing an effective vasculoprotective therapy. The aim of this study was to present a comprehensive survey of current state-of-the-art research into the impact of metabolic and hormonal disorders on development of vascular calcification. Due to strong resemblance to the processes occurring in bone tissue, drugs used for osteoporosis treatment (calcitriol, estradiol, bisphosphonates) may interfere with the processes occurring in the vessel wall. On the other hand, drugs used to treat cardiovascular problems (statins, angiotensin convertase inhibitors, warfarin, heparins) may have an effect on bone tissue metabolism. Efforts to optimally control calcium and phosphate concentrations are also beneficial for patients with end-stage renal disease, for whom vessel calcification remains a major problem.
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Aterosclerose/fisiopatologia , Calciofilaxia/fisiopatologia , Doenças Cardiovasculares/fisiopatologia , Valvas Cardíacas/fisiopatologia , Doenças Metabólicas/complicações , Modelos Biológicos , Osteoporose/tratamento farmacológico , Calcificação Vascular/fisiopatologia , Aterosclerose/etiologia , Calciofilaxia/etiologia , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/etiologia , Hormônios Esteroides Gonadais/metabolismo , Valvas Cardíacas/metabolismo , Humanos , Osteoporose/metabolismo , Cloridrato de Raloxifeno/farmacologia , Calcificação Vascular/etiologiaRESUMO
The protective effect of erythropoietin (Epo) is based on its ability to reduce oxidation and to stabilize the cells. The aim of the study was to evaluate the influence of Epo on malonyl dialdehyde (MDA), intercellular adhesion molecule-1 (ICAM-1) (CD54) and platelet-endothelial cell adhesion molecule-1 (PECAM-1) (CD31) levels on human umbilical vein endothelial cells (HUVECs) stimulated by tumour necrosis factor-α (TNF-α). HUVECs were incubated with Epo (10-40 IU ml⻹) or TNF-α (10-40 ng ml⻹) alone or preincubated with Epo (20 IU ml⻹) and subsequently stimulated with TNF-α (10-40 ng ml⻹). MDA concentrations were measured using the high-performance liquid chromatography, whereas ICAM-1 and PECAM-1 expressions were evaluated by flow cytometry. Incubation with Epo resulted in a decrease in MDA and the increased expressions of ICAM-1 and PECAM-1. Exposure to TNF-α reflected an increase in MDA, ICAM-1 and PECAM-1 levels. These changes were inhibited by preincubation with Epo. The cytoprotective activity proven in this study points to new applications and therapeutic possibilities for Epo.
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Eritropoetina/farmacologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Crioprotetores/farmacologia , Citometria de Fluxo , Humanos , Malondialdeído/análise , Oxirredução , Estresse Oxidativo , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Cytokine and growth factor--erythropoietin (EPO)--apart from it's hematopoietic function is now considered to be a cytoprotective agent in a variety of vascular diseases, nervous system disorders and metabolic impairments. Recent work has elucidated that erythropoietin controls a variety of signal transduction pathways involving Janus-tyrosine kinase 2, protein kinase B, signal transducer and activator of transcription, Wnt proteins, forkhead transcription factors, caspases, and nuclear factor kappaB. Further investigations of cellular pathways controlled by erythropoietin can be the base for therapeutic applicability of this cytokine throughout the body.
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Citoproteção/fisiologia , Eritropoetina/metabolismo , Animais , Humanos , Janus Quinase 2/metabolismo , Doenças Metabólicas/metabolismo , Doenças do Sistema Nervoso/metabolismo , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia , TYK2 Quinase/metabolismo , Doenças Vasculares/metabolismoRESUMO
Increased investment in perinatal health in developing countries has improved the survival of preterm newborns, but their significant multiorgan immaturity is associated with short and long-term adverse consequences. Cathepsin B, as a protease with angiogenic properties, may be related to the process of nephrogenesis. A total of 88 neonates (60 premature children, 28 healthy term children) were included in this prospective study. We collected urine samples on the first or second day of life. In order to determine the concentration of cathepsin B in the urine, the commercially available enzyme immunoassay was used. The urinary concentrations of cathepsin B normalized with the urinary concentrations of creatinine (cathepsin B/Cr.) in newborns born at 30-34, 35-36, and 37-41 (the control group) weeks of pregnancy were (median, Q1-Q3) 4.00 (2.82-5.12), 3.07 (1.95-3.90), and 2.51 (2.00-3.48) ng/mg Cr, respectively. Statistically significant differences were found between the group of newborns born at 30-34 weeks of pregnancy and the control group (p < 0.01), and between early and late preterm babies (PTB) (p < 0.05). The group of children born at 35-36 weeks of pregnancy and the control group did not differ significantly. This result suggests that the elevated urinary cathepsin B/Cr. level may be the result of the kidneys' immaturity in preterm newborns.
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There is a lack of a good marker for early kidney injury in premature newborns. In recent publications, netrin-1 seems to be a promising biomarker of kidney damage in different pathological states. The study aimed to measure the urinary level of netrin-1 depending on gestational age. A prospective study involved 88 newborns (I-60 premature newborns, II-28 healthy term newborns). Additionally, premature babies were divided for 2 groups: IA-28 babies born between 30-34 weeks of gestation and IB-32 born at 35-36 weeks. The median urinary concentration of netrin-1 was: IA-(median, Q1-Q3) 63.65 (56.57-79.92) pg/dL, IB-61.90 (58.84-67.17) pg/dL, and II-60.37 (53.77-68.75) pg/dL, respectively. However urinary netrin-1 normalized by urinary concentration of creatinine were IA-547.9 (360.2-687.5) ng/mg cr., IB-163.64 (119.15-295.96) ng/mg cr., and II-81.37 (56.84-138.58) ng/mg cr., respectively and differ significantly between the examined groups (p = 0.00). The netrin-1/creatinine ratio is increased in premature babies. Further studies examining the potential factors influencing kidney function are necessary to confirm its potential value in the diagnosis of subclinical kidney damage in premature newborns.
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INTRODUCTION: Monitoring of renal function in acute kidney injury in the pediatric population is complicated by the lack of age-related reference values of new biomarkers. Urinary netrin-1 is a new marker to demonstrate early kidney damage. Netrin-1 has a molecular mass of 72 kDa. It is therefore unlikely that it is filtered by the glomerulus under normal conditions. However, netrin-1 is highly induced after acute and chronic kidney injury and excreted in urine in humans. The aim of the study was to determine the normal concentrations of urinary netrin-1 in healthy full-term newborns. MATERIAL AND METHODS: The study included 88 healthy full-term neonates (51 boys and 37 girls) born from normal, uncomplicated pregnancies. The concentration of netrin-1 was determined in urine obtained on the first or second day of life with a commercially available ELISA kit. RESULTS: The urinary concentration of netrin-1 in newborns was independent of gender and time of urine collection. We found a negative correlation between both the urinary netrin-1 concentration and urinary netrin-1 concentration after normalization for urinary creatinine and the birth weight. CONCLUSIONS: This is the first study showing the urinary netrin-1 concentration in healthy full-term newborns. Future investigation is needed to confirm its potential role as a marker of kidney function in this age group.
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This work describes a novel approach for the analysis of 11 phenolic compounds (naringenin, hesperetin, kaempferol, quercetin, epicatechin, epicatechin gallate, epigallocatechin gallate, genistein, daidzein, caffeic acid, gallic acid) in human milk. Clean-up of the sample and extraction of 11 analytes from milk was performed by dispersive liquid-liquid microextraction (DLLME). Under the optimal conditions, the extraction recoveries of 11 analytes were in a range from 94.3% to 108%. For determination of phenolic compounds in extracts, LC-ESI-MS/MS method was used. The calibration curves showed linearity in the concentration ranges from 0.01 to 1500 ng mL-1 and the limits of detection were in a range from 0.18 ng L-1 to 74 ng mL-1. The repeatability and intermediate precision expressed as the relative standard deviations were below 7.6% and 9.9%, respectively. The DLLME-LC-ESI-MS/MS method was successfully applied to the determination of phenolic compounds present in breast milk.
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Cromatografia Líquida/métodos , Microextração em Fase Líquida/métodos , Leite Humano/química , Fenóis/análise , Espectrometria de Massas em Tandem/métodos , Calibragem , Feminino , Análise de Alimentos/métodos , Humanos , PolôniaRESUMO
Thrombocytopenia in small for gestational age (SGA) newborns may be due to placental vascular pathology, fetal consumptive coagulopathy and platelet destruction, local imbalance of thromboxane A2 causing placental vasoconstriction and platelet aggregation. Thrombopoiesis in SGA newborns is poorly recognized. In 61 SGA newborns we evaluated thrombocytopoiesis in relation to gender and the rate maturity expressed as <5th percentile and <10th percentile. Female newborns demonstrated higher thrombopoietin (TPO) level at 92.06 pg/ml than male newborns at 79.81 pg/ml. Newborns less developed <5th percentile, showed increased TPO level of 92.0 pg/ml in comparison to <10th percentile of 78.0 pg/ml. This observation is more pronounced in female newborns. Contrary to our expectations we did not find any statistically significant differences in the percentage of reticulated platelets (PLRET) and platelets count in relation to gender and <5th percentile or <10th percentile. We can postulate intrauterine hypoxia is responsible for the increase of erythropoietin and impairment of thrombopoiesis in SGA newborns.
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Recém-Nascido Pequeno para a Idade Gestacional/sangue , Trombopoese/fisiologia , Plaquetas/citologia , Plaquetas/metabolismo , Feminino , Humanos , Recém-Nascido , Masculino , Trombopoetina/metabolismoRESUMO
The aim of this study was to investigate the influence of epigallocatechin-3-gallate (EGCG), theaflavins (TFs) and black tea extract (BTE) on oxidative stress formation as well as on antioxidant system of human vein endothelial cells (HUVEC). HUVEC were incubated for 0,5 h with 100 mM tert-butyl hydroperoxide (t-BHP) for oxidative stress formation. The influence of EGCG, TFs, and BTE on oxidative stress and antioxidant system parameters was investigated by the pre-incubation for 2 h with 50 mg/mL of each compound. Half hour exposure to t-BHP caused statistically significant decrease in GSH-Px activity and in the content of GSH, vitamin A, vitamin E as well as tryptophan. Moreover, pretreatment of cells with t-BHP caused statistically significant increase in activities of Cu,Zn-SOD, GSSG-R and in the level of MDA and dityrosine. Pretreated with t-BHP endothelial cells, subjected to EGCG, TFs and black tea extract, are partially protected against oxidative activity of t-BHP causing statistically significant increase in GSH-Px activity, GSH and tryptophan level and decrease in MDA and dityrosine level in comparison with HUVEC pretreated with t-BHP group. These results indicate the beneficial effect of tea polyphenolic compounds on HUVEC antioxidant abilities and, in consequence, their protective effect in cell components.
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Células Endoteliais/efeitos dos fármacos , Flavonoides/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Fenóis/farmacologia , Biflavonoides/farmacologia , Catequina/análogos & derivados , Catequina/farmacologia , Células Cultivadas , Células Endoteliais/metabolismo , Humanos , Malondialdeído/análise , Polifenóis , Superóxido Dismutase/metabolismo , terc-Butil Hidroperóxido/farmacologiaRESUMO
Cytoprotection can be defined as the ability to protect cells against wide variety of damaging agents. A series of recent studies indicate that many substances participate in this process. It has been proved that different mechanisms as inhibition of oxidative stress or apoptosis mediate in cytoprotection. However, a number of mechanisms responsible for this extremely compound process remain still unknown. In this revew we discuss the scientific evidence documenting cytoprotective agents and pathways of their activity.
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Citoproteção , Substâncias Protetoras/farmacologia , Animais , Apoptose/efeitos dos fármacos , Humanos , Estresse Oxidativo/efeitos dos fármacosRESUMO
BACKGROUND: Acute Kidney Injury (AKI) is a sudden decrease in kidney function. In the early period, the highest percentage of AKI occurs among newborns hospitalized in the neonatal intensive care units, especially premature neonates. The prognosis of AKI depends on the type and severity of the cause of an injury, the accuracy and the time of diagnosis and treatment. The concentration of serum creatinine is still the main diagnostic test, although it changes in the course of AKI later than glomerular filtration rate GFR. In addition, the reliability of the determination of creatinine level is limited because it depends on many factors. New studies have presented other, more useful laboratory markers of renal function that can be measured in serum and/or in urine. OBJECTIVE: The aim of the work was to present the latest data about tubular and glomerular biomarkers of acute kidney injury in newborns. METHODS: We undertook a structured search of bibliographic databases for peer-reviewed research literature by using focused review topics. According to the conceptual framework, the main idea of research literature has been summarized and presented in this study. RESULTS: The concentrations of some novel biomarkers are higher in serum and/or urine of term and preterm newborns with AKI, especially in the course of perinatal asphyxia. CONCLUSION: In this systematic review of the literature, we have highlighted the usefulness of biomarkers in predicting tubular and/or glomerular injury in newborns. However, novel biomarkers need to prove their clinical applicability, accuracy, and cost-effectiveness prior to their implementation in clinical practice.
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Injúria Renal Aguda/metabolismo , Glomérulos Renais/metabolismo , Túbulos Renais/metabolismo , Animais , Biomarcadores/metabolismo , Humanos , Recém-NascidoRESUMO
BACKGROUND: Intrauterine growth restriction (IUGR) is a poorly understood complication of pregnancy. It may be associated with various diseases in adulthood, such as hypertension, cardiovascular disease, insulin resistance, and end-stage renal disease. OBJECTIVES: The aim of this study was to check whether IUGR affects the function of renal tubules, as assessed by the tubular damage markers neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule 1 (KIM-1). METHODS: The study included 126 term neonates. Thirty-eight newborns were the result of pregnancies complicated by IUGR. Eighty-eight healthy newborns were the result of normal pregnancies with no prenatal or perinatal complications. The concentrations of urinary NGAL and KIM-1 were determined with a commercially available ELISA kit and were normalized for urinary creatinine (Cr) concentration. RESULTS: We found a significantly higher urinary concentration of NGAL and NGAL/Cr ratio in newborns from pregnancies complicated by IUGR when compared to the reference group. We found that female gender was associated with a higher concentration of urinary NGAL and also urinary NGAL/Cr. CONCLUSIONS: This is the first work that demonstrates that urinary NGAL concentration and urinary NGAL/Cr are significantly higher in infants that are small for gestational age than in appropriate-for-gestational-age infants. This might indicate subclinical kidney damage in newborns with IUGR.
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Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/urina , Retardo do Crescimento Fetal/urina , Lipocalina-2/urina , Injúria Renal Aguda/etiologia , Biomarcadores/urina , Estudos de Casos e Controles , Creatinina/urina , Feminino , Receptor Celular 1 do Vírus da Hepatite A/análise , Humanos , Recém-Nascido , Falência Renal Crônica , MasculinoRESUMO
BACKGROUND: Serum aspartate, alanine aminotransferases (AST, ALT), and plasma carnitine are all indirect biomarkers of alcohol abuse. Carnitine transfers long-chain fatty acids from cytoplasm to mitochondria for ß-oxidation. The aim of the study was to determine the relationship between daily alcohol intake, time of alcohol dependence, plasma carnitine, and serum aminotransferases. PATIENTS: We studied 26 men who were addicted for 2-30 years, consuming ethanol from 75 to 700 g/day (alcoholic group), as well as 17 healthy men (control group). RESULTS: In alcoholics, compared to the controls, we found: a significant increase in serum: AST (p = 0.0014), ALT (p = 0.0071), AST/ALT ratio (p < 0.000); significantly lower plasma free carnitine (FC) (p = 0.0316) and total carnitine (TC) (p = 0.0349); and a significant negative correlation between FC (r = -0.6200; R2 = 0.3844; p = 0.0007), TC (r = -0.4365; R2 = 0.1905; p = 0.0258), and time of alcohol dependence, suggesting carnitine as an indirect marker of alcohol abuse. We did not find any significant correlation between FC, TC, and levels of alcohol or aminotransferase activity. CONCLUSION: In the alcoholic group, there was an increase in serum activity of AST, ALT, and AST/ALT ratio that confirms liver injury. In addition, we found low plasma FC and TC, which may indicate damage to mitochondrial ß-oxidation caused by alcohol metabolites. The significantly higher plasma FC and TC in patients consuming the most, compared to patients consuming smaller doses of alcohol, may be caused by a lower carnitine demand of injured liver cells, decreased urinary carnitine excretion by impaired renal tubules, and leakage of carnitine into the blood from damaged muscles by the higher quantities of alcohol. The negative correlation between carnitine concentration and time of alcohol dependence may suggest the potential use of carnitine for treatment of alcohol abuse.
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Alanina Transaminase/sangue , Alcoolismo/sangue , Aspartato Aminotransferases/sangue , Carnitina/sangue , Etanol/farmacologia , Adulto , Biomarcadores/sangue , Estudos de Casos e Controles , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de TempoRESUMO
Hemostasis in preterm newborns is characterized by low reserve functional capacity with special reference to the presence of such risk factors as asphyxia or infection. Platelets play vitally important role in hemostasis. Expression of CD62P is a marker of stimulated or activated blood platelets. The study involved a group of 16 preterm newborns, five girls and 11 boys. DAKO QIFIKIT was applied to calculate the number of these antigens. The mean CD 62P expression was found to be 23,792 per platelet. Correlation was found between antigen density and gestational age r = 0.954, p = 0.01. Evident deficit of P-selectin on the surface of platelets in preterm newborns may be at least in part responsible for platelet dysfunction, with special reference to interaction between circulating leukocytes and combating infection.
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Plaquetas/metabolismo , Selectina-P/metabolismo , Anticorpos Monoclonais/metabolismo , Feminino , Citometria de Fluxo , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Masculino , GravidezRESUMO
OBJECTIVE: Does formation of platelet-derived microparticles correspond to platelet activation? METHODS: The study was performed in 51 preterm newborns, 25 girls and 26 boys. The control group consisted of 55 term newborns, 25 girls and 30 boys. Blood samples were collected from the umbilical artery. The percentage of platelet-derived microparticles and platelet count were determined using flow cytometric analysis based on the CD61-positive antigen. RESULTS: The percentage of platelet-derived microparticles was higher in preterm newborns (5.46) in comparison to term newborns (4.22, p < 0.01). We found 4.61% of platelet-derived microparticles in preterm female newborns and 6.28% in preterm boys (p < 0.0070). The platelet count was 256 x 10(3) microl in girls and 238 x 10(3) microl in boys. Female healthy term newborns presented higher values of platelet-derived microparticles (4.4%) than male newborns (4.07%, p = 0.4725, table 1). The platelet count in girls was found to be 308 x 10(3) microl and in boys 270 x 10(3) microl. CONCLUSIONS: Higher percentage of platelet-derived microparticles in preterm newborns may provide a compensatory mechanism for the hemostatic system.