Regulação da Septina 9 na síndrome do desconforto respiratório agudo associado à malária / The role of Septin 9 in regulating vascular permeability in malarial respiratory distress syndrome

A malária é um problema mundial de saúde, com 249 milhões de casos de infecção, ocasionando 608 mil mortes no ano de 2022. Causada pelo gênero Plasmodium, são cinco principais espécies causadoras da malária no ser humano, o Plasmodium malariae, Plasmodium ovale, Plasmodium knowlesi, Plasmodium vivax e Plasmodium falciparum sendo os dois últimos responsáveis pelo maior número de casos clínicos e mortes ao redor do mundo, transmitida pelo mosquito fêmea do gênero Anopheles durante o repasto sanguíneo. Sabe-se ainda que eritrócitos infectados por Plasmodium berghei ANKA causam alteração no citoesqueleto de actina, consequentemente levando a hiperpermeabiliade da barreira endotelial. Em experimentos in vitro, a imunofluorescência, foi observada alteração do citoesqueleto de actina em células estimuladas com eritrócitos parasitados por PbA (EP), em contrapartida, aquelas não estimuladas (NE) e estimuladas com eritrócitos não parasitados por PbA (EnP), não mostraram alterações no mesmo. Nos experimentos in vivo, ao observar dados coletados, sendo estes respiratórios (penh e frequência respiratória) e parasitemia coletados no 7º DPI, foi observado um mesmo padrão entre o experimento 1 e o experimento 2. Os animais infectados com 106 de eritrócitos infectados, foram alocados em dois grupos, sendo eles hiperparasitemia (HP) ou síndrome do desconforto respiratório agudo-associado a malária (SDRA/SDRA-MA) e comparados àqueles não infectados (NI). Os animais NI, não apresentam parasitemia, em contrapartida, os animais SDRA, tem maior parasitemia que os HP, visto que estes têm aumento em sua parasitemia após o 12º DPI, e assim seguem aumentando gradativamente até levar os animais a óbito.O penh tem o mesmo padrão que a parasitemia, os NI com penh mais baixa que os HPs e os SDRA, sendo dentre estes, o grupo SDRA o mais elevado. A frequência respiratória, por sua vez se apresenta mais elevada no grupo NI, sendo o grupo SDRAmenor que o HP, um achado tido como normal, visto que os pulmões de animais com SDRA sofrem maior dano que os HPs. Apesar de não apresentar um valor significativo, as imagens de gel SDS-PAGE (WB) mostram maior concentração da Septina 9 nos animais com SDRA em comparação com os HPs e com os NIs. O mesmo é observado na qRT-PCR, mesmo sem significância estatística, o valor mostrado nos gráficos temmaior concentração nos SDRA. Assim, a Septina 9 está presente nas CEPP, e, mesmo sem significância estatística, da mesma forma que está presente nas amostras de tecido pulmonar utilizadas no WB e qT-PCR. É hipotetizado ainda que esta proteína pode ser ativada e assim sofrer alteração em sua localização intracelular

Malaria is a global health problem, with 249 million cases of infection, causing 608 thousand deaths in the year 2022. Caused by the genus Plasmodium, there are five main species that cause malaria in humans, Plasmodium malariae, Plasmodium ovale, Plasmodium knowlesi, Plasmodium vivax and Plasmodium falciparum, the last two being responsible for the largest number of clinical cases and deaths around the world, transmitted by the female mosquito of the genus Anopheles during blood meal. It is also known that erythrocytes infected by Plasmodium berghei ANKA (PbA) cause changes in the actin cytoskeleton, consequently leading to hyperpermeability of the endothelial barrier. In in vitro experiments, immunofluorescence, changes in the actin cytoskeleton were observed in cells stimulated with erythrocytes parasitized by PbA (EP), in contrast, those not stimulated (NE) and stimulated with erythrocytes not parasitized by PbA (EnP), did not show changes the same. In the in vivo experiments, when observing collected data, these being respiratory (penh and respiratory frequency) and parasitemia collected on the 7th DPI, the same pattern was observed between experiment 1 and experiment 2. Animals infected with 106 infected erythrocytes were allocated into two groups, namely hyperparasitemia (HP) or malaria-associated acute respiratory distress syndrome (ARDS/ARDS-MA) and compared to those not infected (NI). NI animals do not present parasitemia, on the other hand, ARDS animals have greater parasitemia than HP animals, as the latter have an increase in their parasitemia after the 12th DPI, and thus continue to gradually increase until the animals die. the same pattern as parasitemia, NI with lower penh than HPs and ARDS, among these, the ARDS group being the highest. The respiratory rate, in turn, is higher in the NI group, with the ARDS group being lower than the HP, a finding considered normal, given that the lungs of animals with ARDS suffer greater damage than the HPs. Despite not showing a significant value, SDS-PAGE (WB) gel images show a higher concentration of Septin 9 in animals with ARDS compared to HPs and NIs. The same is observed in qRT-PCR, even without statistical significance, the value shown in the graphs has a higher concentration in ARDS. Thus, Septin 9 is present in CEPP, and, even without statistical significance, in the same way that it is present in lung tissue samples used in WB and qT-PCR. It is also hypothesized that this protein can be activated and thus undergo changes in its intracellular location

A microfluidic device for assessment of E-selectin-mediated neutrophil recruitment to inflamed endothelium and prediction of therapeutic response in sickle cell disease.

Neutrophil recruitment to the inflamed endothelium is a multistep process and is of utmost importance in the development of the hallmark vaso-occlusive crisis in sickle cell disease (SCD). However, there lacks a standardized, clinically feasible approach for assessing neutrophil recruitment to the inflamed endothelium for individualized risk stratification and therapeutic response prediction in SCD. Here, we describe a microfluidic device functionalized with E-selectin, a critical endothelial receptor for the neutrophil recruitment process, as a strategy to assess neutrophil binding under physiologic flow in normoxia and clinically relevant hypoxia in SCD. We show that hypoxia significantly enhances neutrophil binding to E-selectin and promotes the formation of neutrophil-platelet aggregates. Moreover, we identified two distinct patient populations: a more severe clinical phenotype with elevated lactate dehydrogenase levels and absolute reticulocyte counts but lowered fetal hemoglobin levels associated with constitutively less neutrophil binding to E-selectin. Mechanistically, we demonstrate that the extent of neutrophil activation correlates with membrane L-selectin shedding, resulting in the loss of ligand interaction sites with E-selectin. We also show that inhibition of E-selectin significantly reduces leukocyte recruitment to activated endothelial cells. Our findings add mechanistic insight into neutrophil-endothelial interactions under hypoxia and provide a clinically feasible means for assessing neutrophil binding to E-selectin using clinical whole blood samples, which can help guide therapeutic decisions for SCD patients.

Clinical assessment of endothelial function in convalescent COVID-19 patients: a meta-analysis with meta-regressions.

BACKGROUND: Endothelial dysfunction has been proposed to play a key role in the pathogenesis of coronavirus disease 2019 (COVID-19) and its post-acute sequelae. Flow-mediated dilation (FMD) is recognized as an accurate clinical method to assess endothelial function. Thus, we performed a meta-analysis of the studies evaluating FMD in convalescent COVID-19 patients and controls with no history of COVID-19. METHODS: A systematic literature search was conducted in the main scientific databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Using the random effects method, differences between cases and controls were expressed as mean difference (MD) with 95% confidence intervals (95% CI). The protocol was registered on PROSPERO with reference number CRD42021289684. RESULTS: Twelve studies were included in the final analysis. A total of 644 convalescent COVID-19 patients showed significantly lower FMD values as compared to 662 controls (MD: -2.31%; 95% CI: -3.19, -1.44; p < 0.0001). Similar results were obtained in the sensitivity analysis of the studies that involved participants in either group with no cardiovascular risk factors or history of coronary artery disease (MD: -1.73%; 95% CI: -3.04, -0.41; p = 0.010). Interestingly, when considering studies separately based on enrolment within or after 3 months of symptom onset, results were further confirmed in both short- (MD: -2.20%; 95% CI: -3.35, -1.05; p < 0.0001) and long-term follow-up (MD: -2.53%; 95% CI: -4.19, -0.86; p = 0.003). Meta-regression models showed that an increasing prevalence of post-acute sequelae of COVID-19 was linked to a higher difference in FMD between cases and controls (Z-score: -2.09; p = 0.037). CONCLUSIONS: Impaired endothelial function can be documented in convalescent COVID-19 patients, especially when residual clinical manifestations persist. Targeting endothelial dysfunction through pharmacological and rehabilitation strategies may represent an attractive therapeutic option.Key messagesThe mechanisms underlying the post-acute sequelae of coronavirus disease 2019 (COVID-19) have not been fully elucidated.Impaired endothelial function can be documented in convalescent COVID-19 patients for up to 1 year after infection, especially when residual clinical manifestations persist.Targeting endothelial dysfunction may represent an attractive therapeutic option in the post-acute phase of COVID-19.

In Vitro Assessment of Poly-N-Vinylpyrrolidone/Acrylic Acid Nanoparticles Biocompatibility in a Microvascular Endothelium Model.

An amphiphilic copolymer of N-vinyl-2-pyrrolidone and acrylic acid-namely, p(VP-AA)-OD6000 (p(VP-AA))-was synthesized to prepare p(VP-AA) nanoparticles (NPs). Furthermore, the copolymer was linked with CFSE, and the so-prepared nanoparticles were loaded with the DiI dye to form D nanoparticles (DNPs). In this study, as demonstrated by immunofluorescence microscopy, immunofluorescence, and confocal microscopy, DNPs were readily taken up by human microvascular endothelial cells (HMEC-1) cells in a concentration-dependent manner. Upon uptake, both the CFSE dye (green stain) and the DiI dye (red stain) were localized to the cytoplasm of treated cells. Treatment with p(VP-AA) did not affect the viability of normal and challenged with LPS, HMEC-1 cells at 0.010 mg/mL and induced a dose-dependent decrease of these cells' viability at the higher concentrations of 0.033 and 0.066 mg/mL (p ≤ 0.01; p ≤ 0.001, respectively). Furthermore, we focused on the potential immunological activation of HMEC-1 endothelial cells upon p(VP-AA) NPs treatment by assessing the expression of adhesion molecules (E-Selectin, ICAM-1, and V-CAM). NPs treatments at concentrations utilized (p = NS) did not affect individual adhesion molecules' expression. p(VP-AA) NPs do not activate the endothelium and do not affect its viability at pharmacologically relevant concentrations.

Global endothelial function assessment using pulse wave analysis in hypercholesterolemia

To compare global endothelial function assessed by pulse wave analysis (PWA) using the ratio of endothelium dependent vasodilatation (EDV) to endothelium independent vasodilatation (EIV) in patients with hypercholesterolemia and controls. 92 subjects [46 hypercholesterolemics, 46 controls] were studied at standardized conditions. Baseline augmentation index (AIx) was assessed followed by the administration of 0.5 mg sublingual nitroglycerine, an endothelium independent vasodilator. AIx was assessed and the maximum change in AIx after nitroglycerine was recorded as EIV. After a washout period of 30 minutes, 400 µg of inhaled salbutamol, an endothelium dependent vasodilator was administered. AIx was assessed again and the maximum change in AIx after salbutamol was recorded as EDV. Global endothelial function was calculated as EDV:EIV ratio. EDV and EIV in patients with hypercholesterolemia compared to controls were 2.97 ± 3.95 and 6.65 ± 3.80 (p<0.001); and 13.41 ± 4.57 and 15.88 ± 4.78 (p=0.01) respectively. EDV:EIV ratio was significantly reduced in patients with hypercholesterolemia compared to controls; 0.21 ± 0.38 and 0.44 ± 0.24 (p<0.001) respectively. EDV:EIV ratio was significantly reduced in patients with hypercholesterolemia compared to controls. PWA is a potential clinical tool to assess global endothelial function in patients with hypercholesterole

Functional assessment of two variants of unknown significance in TEK by endothelium-specific expression in zebrafish embryos.

Vascular malformations are most often caused by somatic mutations of the PI3K/mTOR and the RAS signaling pathways, which can be identified in the affected tissue. Venous malformations (VMs) commonly harbor PIK3CA and TEK mutations, whereas arteriovenous malformations (AVMs) are usually caused by BRAF, RAS or MAP2K1 mutations. Correct identification of the underlying mutation is of increasing importance, since targeted treatments are becoming more and more relevant, especially in patients with extensive vascular malformations. However, variants of unknown significance (VUSs) are often identified and their pathogenicity and response to targeted therapy cannot be precisely predicted. Here, we show that zebrafish embryos can be used to rapidly assess the pathogenicity of novel VUSs in TEK, encoding for the receptor TIE2, present on endothelial cells of VMs. Endothelium-specific overexpression of TEK mutations leads to robust induction of VMs, whereas MAP2K1 mutations cause AVMs in our zebrafish model. TEK mutations are often found as double mutations in cis; using our model, we show that double mutations have an additive effect in inducing VMs compared with the respective single variants. The clinically established mTOR-inhibitor sirolimus (rapamycin) efficiently abrogates the development of VMs in this zebrafish model. In summary, endothelium-specific overexpression of patient-derived TEK variants in the zebrafish model allows assessment of their pathogenic significance as well as testing of candidate drugs in a personalized and mutation-specific approach.

Assessment of tissue perfusion and vascular function in mice by scanning laser Doppler perfusion imaging.

Post-occlusive reactive hyperemia (PORH) is a key feature of physiological vasomotion to appropriately match the supply/demand ratio of tissues. This adaptive mechanism is severely disturbed in endothelial dysfunction with a reduced flow-mediated dilation (FMD). Reduced PORH and FMD are powerful prognostic risk factors in cardiovascular diseases. While these parameters are frequently determined in human beings, comparable methods applicable to mouse models are sparse. We aimed to evaluate the applicability and accuracy of scanning laser Doppler perfusion imaging (LDPI) to measure PORH in the mouse hindlimb. Changes in mean perfusion in response to vasoactive drugs and PORH (assessed by scanning LDPI) were compared with changes in diameter and blood flow in the femoral artery, as assessed by high-resolution ultrasound. We found that the measured LDPI signal significantly correlated with changes of inflow into the femoral artery. Vasodilation induced by administration of nitroglycerine and acetylcholine increased vessel diameter, blood flow and mean perfusion, while vasoconstriction following administration of epinephrine decreased all three parameters. PORH was induced by temporal occlusion of the femoral artery with an external cuff. During occlusion, mean perfusion decreased to a condition of zero-perfusion and release of the cuff induced an immediate increase in blood flow that was followed by femoral artery dilation driving PORH/perfusion. Surgical removal of the femoral artery decreased mean perfusion to a zero-perfusion level and fully abolished PORH. Importantly, the measurement of the PORH response by scanning LDPI is highly reproducible as determined by repeated measurements and intra/interobserver variation analysis. Last, we found that the PORH response was dependent on nitric oxide synthase and cyclooxygenase and declined with age. Thus, we here provide novel and robust non-invasive methods to serially measure tissue perfusion at baseline and during physiological and pharmacological modulation of vasomotor tone in the hindlimb of mice. The application of these LDPI scanning and ultrasound-based methods may be useful for testing the effects of drugs affecting vasomotor function or future elucidation of mechanisms leading to vasomotor dysfunction in mice in vivo.

Assessment of intima-media thickness of the carotid artery and intraluminal diameter of the brachial artery as cardiovascular risk markers in Brazilian adolescents with overweight or obesity.

Background The intima-media thickness of the carotid artery (cIMT) and endothelial dysfunction are associated with cardiovascular (CV) disease. Objectives To evaluate the correlation between cIMT, brachial intraluminal diameter and flow-mediated vasodilation on the reactive hyperemia phase in adolescents with obesity with predictors of CV risk. Methods Seventy-three pubertal patients with overweight or obesity were evaluated (45 girls) with a mean (standard deviation [SD]) age of 12.9 (2.5) years. Patients underwent anthropometric measurements and had the lipid profile, oral glucose tolerance test (oGTT) and serum intercellular adhesion molecule-1 (sICAM-1) levels analyzed. The ratios of the waist circumference (WC)/height (WHtR) and triglycerides (TG)/high-density lipoprotein cholesterol (HDL-C), homeostatic model assessment of insulin resistance (HOMA-IR), the Matsuda index and insulin area under the curve (AUC) were calculated. All patients were evaluated for cIMT and arterial blood flow velocity of the brachial artery. Results 75.3% of the patients had high cIMT values. We found a positive correlation between WHtR and cIMT (r = 0.233; p = 0.050). There was a positive correlation between sICAM-1 and insulin AUC (r = 0.323; p = 0.012) and WHtR (r = 0.258; p = 0.047). Patients with abnormal arterial dilation had higher sICAM-1 values (p = 0.02) despite having smaller WHtR (p = 0.046). Conclusions These adolescents with obesity had high cIMT values. Insulin resistance was associated with sICAM-1. Endothelial dysfunction was positively correlated with sICAM-1. There is no consensus about what the best laboratorial approach to evaluate insulin resistance in adolescents is, and the cutoff values of each method are arbitrary. So, as we saw earlier, the association between anthropometric data (WHtR) and ultrasound findings could be useful to evaluate the CV risk of these adolescents with obesity, because of its practical, direct and low-cost value.

[Bulbar capillaroscopy and plethysmography for assessment of blood microcirculation and endothelium properties in type 1 diabetes]. / Bul'barnaia kapilliaroskopiia i pletizmografiia v otsenke mikrotsirkuliatsii krovi i svoistv éndoteliia pri sakharnom diabete 1-go tipa.

PURPOSE: To evaluate the properties of the microvasculature of bulbar conjunctiva and to assess the function of endothelium of the main arteries in type 1 diabetes mellitus (T1DM). MATERIAL AND METHODS: The study included 35 patients with T1DM and initial nonproliferative diabetic retinopathy (NPDR). The control group consisted of 30 subjects. In addition to standard ophthalmic examination, all participants underwent digital bulbar capillaroscopy (DBC), pulse wave velocity (PWV) test, and plethysmography for assessment of endothelium function. RESULTS: According to DBC, in comparison to the control group, diabetic patients with even initial NPDR had disturbances of blood microcirculation manifested as increased average venous vessel width (p=0.04), reduced arterial capillary blood flow (p=0.02), increased blood sludging (p=0.001), and increased duration of blood stasis (p=0.03). Evaluation of vessel endothelium in T1DM patients with NPDR showed increased PWV (p=0.03). CONCLUSION: Diabetic patients with NPDR showed marked changes of capillary blood flow alongside signs of endothelial dysfunction. The most significant change was increased venous vessel width.

Uroflowmetry alterations in patients with autosomal dominant polycystic kidney disease.

OBJECTIVE: Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a heterogeneous inherited disease characterized by renal and extrarenal manifestations with progressive fluid-filled cyst development leading to end-stage renal disease. Our aim was to evaluate the prevalence of obstructive urological disease in ADPKD patients and possible associations with endothelial dysfunction, nutritional, metabolic and inflammatory markers. PATIENTS AND METHODS: The study included ADPKD patients and control group, who carried out uroflowmetry, an assessment of renal function, metabolic and nutritional parameters and an evaluation of endothelial dysfunction and atherosclerotic markers, such as Renal Resistive Index (RRI), Intima-Media Thickness (IMT) and Flow-Mediated Dilation (FMD). RESULTS: We enrolled 37 ADPKD patients (20 males with 51.0 ± 14.3 years) and 34 control group (18 males with 60.7 ± 14.4 years). We showed a significant reduction in Max Flow Rate (Qmax) (p ≤ 0.001), age (p = 0.006), FMD (p = 0.023) and Voiding Volume (p = 0.053), in addition to a significant increase in Voiding Time and Diastolic Blood Pressure (p ≤ 0.001, p = 0.049; respectively) in ADPKD patients with respect to control group. Moreover, we found a negative correlation between Qmax and creatinine (r= -0.44, p = 0.007), RRI (r= -0.49, p ≤0.001) and intact Parathyroid Hormone (r = -0.329, p = 0.046), while we found a positive correlation between Qmax and MDRD (r = 0.327, p = 0.048) and between Voiding Time and serum uric acid (r= 0.34, p = 0.039) in ADPKD patients with respect to control group. CONCLUSIONS: In our study, we showed an elevated prevalence of urological functional diseases in ADPKD patients; therefore, we suggest to include uroflowmetry in the assessment of these patients, considering the non-invasiveness, repeatability and low cost of the exam. An early intervention could slow down the progression of renal damage and an early screening of the main cardiovascular risk factors could reduce the high morbidity and mortality in ADPKD patients.

Brachial Artery Wall Stiffness Assessment by Shear Wave Elastography: A Promising New Diagnostic Tool for Endothelial Dysfunction Detection.

OBJECTIVES: This study was designed to measure the changes in brachial artery wall stiffness by shear wave elastography (SWE) and evaluate the accuracy of SWE changes for detection of endothelial dysfunction. METHODS: Sixty-five consecutive participants (19 patients with atherosclerosis proven by coronary angiography, 16 healthy young adults, 15 patients with cardiovascular risk factors, and 15 healthy older adults between 50 and 60 years) were prospectively included in this study. They were examined in the same week by SWE, and flow-mediated dilatation was evaluated for each patient. RESULTS: The mean flow-mediated dilatation values ± 2 SDs after forearm occlusion were 8.54% ± 1.4% in healthy young adults, 7.61% ± 1.4% in healthy older adults, 5.83% ± 0.7% in patients with risk factors (P < .001), and 3.81% ± 2.4% in patients with atherosclerosis (P < .001, with respect to the risk factor group). There was a significant decrease in stiffness measurements in parallel with the increase in flow-mediated dilatation: 19.9% ± 6.3% in healthy young adults, 16.3% ± 5.1% in healthy older adults, 9.8% ± 5.4% in patients with risk factors (P < .05 with respect to the group with no risk factors), and 7.8% ± 6.4% in patients with atherosclerosis (P < .001 with respect to the healthy older adults). CONCLUSIONS: Shear wave elastography in combination with flow-mediated dilatation could be a promising, widely available noninvasive diagnostic tool for detecting endothelial dysfunction.

Clinical assessment of endothelial function in patients with chronic obstructive pulmonary disease: a systematic review with meta-analysis.

Patients with chronic obstructive pulmonary disease (COPD) have an increased cardiovascular morbidity and mortality. Flow-mediated (FMD) and nitrate-mediated dilatation (NMD) are considered non-invasive methods to assess endothelial function and surrogate markers of subclinical atherosclerosis. We performed a systematic review with meta-analysis and meta-regression to evaluate the impact of COPD on FMD and NMD. Studies were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases. The random-effect method was used to take into account the variability among included studies. A total of eight studies were included in the final analysis, eight with data on FMD (334 COPD patients) and two on NMD (104 COPD patients). Compared to controls, COPD patients show a significantly lower FMD (MD -3.15%; 95% CI -4.89, -1.40; P < 0.001) and NMD (MD -3.53%; 95% CI -7.04, -0.02; P = 0.049). Sensitivity analyses substantially confirms the results. Meta-regression models show that a more severe degree of airway obstruction is associated with a more severe FMD impairment in COPD patients than in controls. Regression analyses confirm that the association between COPD and endothelial dysfunction is independent of baseline smoking status and most traditional cardiovascular risk factors. In conclusion, COPD is significantly and independently associated with endothelial dysfunction. These findings may be useful to plan adequate cardiovascular prevention strategies in this clinical setting, with particular regard to patients with a more severe disease.

Assessment of Basilar Artery Reactivity in Stroke and Subarachnoid Hemorrhage Using Wire Myograph.

Blood flow regulation of normal cerebral arteries is a critical and important factor to supply the brain tissue with nutrients and oxygen. Stroke insult results in a disruption or reduction in cerebral arteries' blood flow with subsequent brain tissue damage. Hemorrhagic stroke is one type of stroke and accounts for about 13 % of all of stroke insults. In this type of stroke, the cerebral artery breaks open and causes bleeding in or surrounding the brain. Subsequently, this bleeding causes blood vessels to constrict in a process called vasospasm, in which the vessels narrow and impede the blood flow to brain tissue. Hemorrhagic stroke is the major cause of prolonged constriction of cerebral arteries. This leads to partial brain damage and sometimes death in patients with aneurysmal subarachnoid hemorrhage. Among the key delicate techniques to assess small blood vessel functionality is the wire myograph, which can be utilized in several cerebral injury models including stroke. The wire myograph is a device that provides information about the reactivity, stiffness, and elasticity of small blood vessels under isometric conditions. In this book chapter, we describe the techniques involved in wire myography assessment and the different measures and parameters recorded; we describe the utility of this technique in evaluating the effects of subarachnoid hemorrhage on basilar artery sensitivity to different agonists.

Nailfold capillaroscopy assessment of microcirculation abnormalities and endothelial dysfunction in children with primary or secondary Raynaud syndrome.

Raynaud syndrome (RS) manifests as episodes of transient spasms of peripheral blood vessels, most often in response to cold. The reason of that symptom (primary RS (pRS)) usually cannot be found but may be accompanied by some autoimmune diseases (secondary RS (sRS)). In this study, we assessed microcapillary status and serum concentrations of chosen cytokines, adhesive molecules, and nitric oxide (NO) in patients with pRS and sRS in comparison with healthy children. Eighty-six patients with RS were enrolled into the study, including 52 with pRS and 34 with sRS. The control group consisted of 29 healthy children. A decrease in myorelaxative and anticoagulant abilities was observed, with simultaneous prevalence of vasopressor substances and procoagulative activity. Therefore, several important factors such as endothelin-1 (ET-1), E-selectin (E-sel), interleukin-18 (IL-18), and nitrogen oxide (NO) were also analyzed. Two types of capillaroscopy status were determined: normal and microangiopathic. There was a significant relationship between presence of microangiopathy and higher serum ET-1 (p = 0.018) and E-sel (p = 0.021) levels. Similarly, we have found a correlation between presence of ANA and higher ET-1 (p = 0.005), but not E-sel (p = 0.241). In patients with pRS, we found significant relationship between ANA and higher ET-1 (p = 0.008). No such relations were observed in sRS patients. Our data indicates that external factor-induced vasoconstrictive effects dominated in pRS, whereas in sRS in the course of connective tissue diseases, it was accompanied by coexistent vasodilation due to endothelial dysfunction. The latter phenomenon is at least partially dependent on insufficient NO release.

Non-invasive endothelial function assessment using digital reactive hyperaemia correlates with three-dimensional intravascular ultrasound and virtual histology-derived plaque volume and plaque phenotype.

BACKGROUND AND AIM: To study relationships between endothelial dysfunction (ED) and coronary atherosclerosis derived from intravascular ultrasound (IVUS) and virtual histology (VH). METHODS: Endothelial dysfunction was examined by EndoPAT system (Itamar Medical) in 56 patients who underwent IVUS and VH (Volcano corp.). Reactive hyperaemia index (RHI) < 2 was used for definition of ED. IVUS sequences were divided into 5 mm-long non-overlapping and adjacent vessel segments. Plaque phenotype was determined for each frame and 5 mm vessel segment was labeled according to highest frame score (from 0 for "no lesion" to 5 for "thin cap fibroatheroma; TCFA"). RESULTS: IVUS-VH data were collected from 41 patients suitable for three-dimensional analysis. Patients with ED exhibited larger plaque burden than those without ED (0.46 ± 0.08 vs. 0.39 ± 0.07, p = 0.014), smaller lumen area (8.59 ± 2.19 vs. 11.90 ± 3.50, p = 0.016), higher plaque risk score (2.82 ± 1.18 vs. 1.84 ± 0.90, p = 0.012), and higher number of TCFA frames (0.36 ± 0.22 vs. 0.22 ± 0.16, p = 0.038). Relative amounts of fibrous tissue correlated positively with RHI (p = 0.034, r = 0.33). The numbers of fibroatheromas and calcified plaques correlated with RHI inversely (r = -0.34, p = 0.031 and r = -0.32, p = 0.044, respectively). CONCLUSIONS: Endothelial dysfunction correlates with severity and phenotype of coronary lesions and can contribute to non-invasive detection of individuals with higher risk of cardiovascular events.

Assessment of endothelial function by flow-mediated dilation in diabetic patients: effects of physical exercise

The endothelium is now recognized as an endocrine organ that acts to maintain vascular homeostasis regulating the vascular tone and structure. The endothelial cells synthetize a variety of mediators among them, the main agent is the nitric oxide (NO), a potent vasodilator. NO exerts its protective role preventing leukocyte adhesion and migration, expression of adhesion molecules, platelet aggregation, cell proliferation, and promoting the relaxation of smooth muscle cells. On the other hand, endothelial dysfunction present in many chronic diseases such as atherosclerosis, coronary artery disease, peripheral artery disease, hypertension and diabetes mellitus, is characterized by reduced NO bioavailability. Thus, a few decades ago, measurement of endothelial function has emerged as valuable tool that provides insights in the pathophysiological mechanisms, opportunity to identify early disease and cardiovascular risk, preventing future events or avoiding the progression of the disease. Diabetic patients, particularly, have been a target to apply this technique, mainly because this condition has been related with an impairment of endothelium-dependent dilation and it is believed that the endothelium dysfunction is the basis of diabetes complications such as coronary artery disease and accelerated atherosclerosis. In addition, cardiovascular complications represent the leading cause of morbidity and death in diabetes mellitus. Besides pharmacological therapy, lifestyle modifications have been recommended by specific organizations as a strategy to improve the endothelial function or even prevent the development of diabetes. The aim of this mini eview is to give an update about the importance of endothelium, most common non-invasive technique to evaluate its function, and to summarize some mechanisms involved in endothelial dysfunction and the beneficial effects of exercise in diabetes mellitus.

Invasive assessment of the coronary microcirculation in the catheter laboratory.

Historically much of our understanding of the coronary circulation has been centered towards the epicardial vessels. However, recent work has highlighted the importance of the coronary microcirculation across a broad spectrum of clinical conditions in influencing patient outcomes. Therefore an ability to measure microvascular function is most valuable. While evaluation of the epicardial coronary circulation is widely understood, interrogation of the coronary microcirculation is more complex. Many methods are available to assess the integrity of the microcirculation in the catheter laboratory. This review will discuss the physiology of the coronary microcirculation and evaluate the utility of available invasive techniques.

Novel coronary heart disease risk factors at 60-64 years and life course socioeconomic position: the 1946 British birth cohort.

Social disadvantage across the life course is associated with a greater risk of coronary heart disease (CHD) and with established CHD risk factors, but less is known about whether novel CHD risk factors show the same patterns. The Medical Research Council National Survey of Health and Development was used to investigate associations between occupational socioeconomic position during childhood, early adulthood and middle age and markers of inflammation (C-reactive protein, interleukin-6), endothelial function (E-selectin, tissue-plasminogen activator), adipocyte function (leptin, adiponectin) and pancreatic beta cell function (proinsulin) measured at 60-64 years. Life course models representing sensitive periods, accumulation of risk and social mobility were compared with a saturated model to ascertain the nature of the relationship between social class across the life course and each of these novel CHD risk factors. For interleukin-6 and leptin, low childhood socioeconomic position alone was associated with high risk factor levels at 60-64 years, while for C-reactive protein and proinsulin, cumulative effects of low socioeconomic position in both childhood and early adulthood were associated with higher (adverse) risk factor levels at 60-64 years. No associations were observed between socioeconomic position at any life period with either endothelial marker or adiponectin. Associations for C-reactive protein, interleukin-6, leptin and proinsulin were reduced considerably by adjustment for body mass index and, to a lesser extent, cigarette smoking. In conclusion, socioeconomic position in early life is an important determinant of several novel CHD risk factors. Body mass index may be an important mediator of these relationships.