COVID-19 and ECMO: the interplay between coagulation and inflammation-a narrative review

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has presently become a rapidly spreading and devastating global pandemic. Veno-venous extracorporeal membrane oxygenation (V-V ECMO) may serve as life-saving rescue therapy for refractory respiratory failure in the setting of acute respiratory compromise such as that induced by SARS-CoV-2. While still little is known on the true efficacy of ECMO in this setting, the natural resemblance of seasonal influenza's characteristics with respect to acute onset, initial symptoms, and some complications prompt to ECMO implantation in most severe, pulmonary decompensated patients. The present review summarizes the evidence on ECMO management of severe ARDS in light of recent COVID-19 pandemic, at the same time focusing on differences and similarities between SARS-CoV-2 and ECMO in terms of hematological and inflammatory interplay when these two settings merge.

Plasma Levels of Protein Z in Ischemic Stroke: A Systematic Review and Meta-Analysis

The association between blood levels of protein Z (PZ) and risk of ischemic stroke remains poorly understood. We aimed to assess this potential relationship through a meta-analysis of case–control studies. PubMed, Scopus, Web of Science Core Collection, and the Cochrane Library were searched from April 1984 to April 2019. We selected case–control studies comparing PZ levels in adult patients with ischemic stroke and controls without ischemic stroke. Six case–control studies, with a total of 1,011 ischemic stroke patients and 1,128 controls, were included. Patients in the acute phase of ischemic stroke showed significantly higher levels of PZ compared with patients in the convalescent phase (standardized mean difference [SMD]: 0.289 mg/L; 95% confidence interval [CI]: 0.010, 0.569; p = 0.043). No significant differences in PZ levels were found between patients and controls in the acute phase (SMD: −0.059 mg/L; 95% CI: −0.570, 0.452; p = 0.821) or in the convalescent phase of ischemic stroke (SMD: −0.341 mg/L; 95% CI: −0.736, 0.055; p = 0.091). Subgroup analysis indicated that older patients (≥ 50 years old) had lower PZ levels than similarly aged controls. In contrast, when the study groups came from the United States and Australia or Europe no significant differences in PZ levels existed between patients and controls. No association between PZ and ischemic stroke was identified in this meta-analysis. The acute phase of ischemic stroke was associated with higher levels of PZ.

Transcatheter aortic valve replacement with Lotus and Sapien 3 prosthetic valves: a systematic review and meta-analysis

Background

Frequent occurrence of paravalvular leak (PVL) after transcatheter aortic valve replacement (TAVR) was the main concern with early-generation devices and focused technological improvements. Current systematic review and meta-analysis sought to compare outcomes of TAVR for severe native valve stenosis with next-generation devices: Lotus and Sapien 3.

Methods

Electronic databases were screened for studies comparing outcomes of TAVR with Lotus and Sapien 3. In a random-effects meta-analysis, the pooled incidence rates of procedural, clinical and functional outcomes according to VARC-2 definitions were assessed.

Results

Eleven observational studies including 2,836 patients (Lotus N=862 vs. Sapien 3 N=1,974) met inclusion criteria. No differences were observed regarding composite endpoints—device success and early safety. Similarly, 30-day mortality, major vascular complications, acute kidney injury and serious bleeding events were similar with both devices. Lotus valve demonstrated 35% reduction of the risk for mild PVL: risk ratio (RR) 0.65, 95% confidence interval (CI): 0.49–0.85, P=0.002; but there were no statistical differences with regard to moderate/severe PVL (RR 0.56, 95% CI: 0.18–1.77, P=0.320). Lotus valves produced significantly higher mean transaortic gradients: mean difference (MD) 0.88 mmHg, 95% CI, 0.24–1.53 mmHg, P=0.007; however, without translation into higher rate of prosthesis-patient mismatch (RR 1.10, 95% CI: 0.82–1.47, P=0.540). As compared to Sapien 3, Lotus device placement was associated with significantly higher rate of permanent pacemaker implantation (RR 2.30, 95% CI: 1.95–2.71, P<0.00001) and cerebrovascular events (RR 1.76, 95% CI: 1.03–2.99, P=0.040).

Conclusions

Lotus valve, as compared with Sapien 3, was associated with lower risk for PVL but higher risk for permanent pacemaker implantation and cerebrovascular events.

Transcatheter Aortic Valve Replacement with Self-Expandable ACURATE neo as Compared to Balloon-Expandable SAPIEN 3 in Patients with Severe Aortic Stenosis: Meta-Analysis of Randomized and Propensity-Matched Studies

Frequent occurrence of paravalvular leak (PVL) after transcatheter aortic valve replacement (TAVR) was the main concern with earlier-generation devices. Current meta-analysis compared outcomes of TAVR with next-generation devices: ACURATE neo and SAPIEN 3. In random-effects meta-analysis, the pooled incidence rates of procedural, clinical and functional outcomes according to VARC-2 definitions were assessed. One randomized controlled trial and five observational studies including 2818 patients (ACURATE neo n = 1256 vs. SAPIEN 3 n = 1562) met inclusion criteria. ACURATE neo was associated with a 3.7-fold increase of moderate-to-severe PVL (RR (risk ratio): 3.70 (2.04-6.70); P < 0.0001), which was indirectly related to higher observed 30-day mortality with ACURATE valve (RR: 1.77 (1.03-3.04); P = 0.04). Major vascular complications, acute kidney injury, periprocedural myocardial infarction, stroke and serious bleeding events were similar between devices. ACURATE neo demonstrated lower transvalvular pressure gradients both at discharge (P < 0.00001) and at 30 days (P < 0.00001), along with lower risk of patient-prosthesis mismatch (RR: 0.29 (0.10-0.87); P = 0.03) and pacemaker implantation (RR: 0.64 (0.50-0.81); P = 0.0002), but no differences were observed regarding composite endpoints early safety and device success. In conclusion, ACURATE neo, as compared with SAPIEN 3, was associated with higher rates of moderate-to-severe PVL, which were indirectly linked with increased observed 30-day all-cause mortality.

Novel Markers for Predicting Type 2 Neurologic Complications of Coronary Artery Bypass Grafting

BACKGROUND

Type 2 neurologic complications of coronary artery bypass grafting (CABG) include postoperative cognitive dysfunction and delirium. Although relevant clinically, they are rarely properly recognized outside of dedicated research setting, as their identification is complex and time-consuming. The aim of this study was to examine the diagnostic potential of 4 novel brain-injury biomarkers for predicting these sequelae at the completion of off-pump CABG.

METHODS

A total of 100 consecutive patients scheduled for elective isolated off-pump CABG were enrolled. Control group of patients without neurological complications (n = 48) was compared separately to study groups diagnosed with postoperative cognitive dysfunction (n = 39) and delirium (n = 26). Serum concentrations of glial fibrillary acidic protein, neuroserpin, phosphorylated axonal neurofilament subunit H, and visinin-like protein 1 were evaluated at baseline, end of surgery, as well as on postoperative day 1 and 7.

RESULTS

Increased end of surgery to baseline ratio of neuroserpin predicted the occurrence of both postoperative cognitive dysfunction (area under the curve = 0.655, 95% confidence interval 0.54-0.77) and delirium (area under curve = 0.643, 95% confidence interval 0.52-0.77). Concentrations of neuroserpin were significantly higher on postoperative day 7 compared with end of surgery and postoperative day 1 in all groups.

CONCLUSIONS

Among novel biochemical markers of brain damage, neuroserpin may be a promising predictor of type 2 neurological complications and may express neuroregeneration after off-pump CABG, whereas glial fibrillary acidic protein, phosphorylated axonal neurofilament subunit H, and visinin-like protein 1 may not be suitable for this clinical setting.

Association of Neutrophil-to-Lymphocyte Ratio and Lymphocyte-to-Monocyte Ratio with Treatment Modalities of Acute Ischaemic Stroke: A Pilot Study

Background and Objectives: Ischaemic stroke (IS) is the leading cause of death and disability worldwide. All stages of cerebral ischaemia, but especially acute phase, are associated with inflammatory response. Recent studies showed that neutrophil-to-lymphocyte ratio (NLR) and lymphocyte-to-monocyte ratio (LMR) may be used to assess inflammation in IS. To test whether there is a relationship between these parameters and type of stroke treatment, we analysed NLR and LMR in IS patients treated with three different modalities. Materials and Methods: The study included 58 adults with acute IS. A total of 28 patients received intravenous thrombolysis. In another 10 patients, the thrombolytic therapy was followed by thrombectomy and 20 patients did not undergo causal treatment. Blood samples were obtained within 24 h of the stroke diagnosis to calculate NLR and LMR. Next, NLR and LMR of the study subgroups were compared. Results: Our study revealed that NLR was significantly higher in patients treated with thrombectomy following thrombolysis, compared to no causal treatment. Statistical analysis demonstrated that patients with high National Institutes of Health Stroke Scale (NIHSS) scores presented higher NLR than in those with low NIHSS scores. Additionally, patients with high-sensitivity C-reactive protein (hs-CRP) ≥ 3 mg/L presented with significantly higher NLR and significantly lower LMR than the group of patients with lower hs-CRP (<3 mg/L). Conclusions: The main finding of this pilot study was that NLR in IS patients treated using thrombectomy following thrombolysis was markedly higher than that in other treatment groups, which was associated with increased severity of the disease in these patients. Therefore, patients with higher NLR may be expected to have more severe stroke. The link between stroke severity and NLR deserves further study.

Female Volleyball Players Are More Prone to Cortisol Anticipatory Stress Response than Sedentary Women

Background and Objectives: Top-level sports performance places heavy physical and psychological demands on elite-level athletes, which can be a source of increased levels of stress. Therefore, high-level volleyball players may present altered cardiovascular and endocrinological stress response during stressful events. Although many previous studies have examined the response to stress on athletes, most of them regarded only males, while the impact of the female menstrual cycle has rarely been taken into account. We aimed to study psychophysiological response to anticipatory stressor through analysis of heart rate, self-reported anxiety level, and salivary cortisol in healthy young female athletes by minimalizing the effect of confounders. Materials and Methods: A total of 55 females (25 members of the best league for female volleyball players in Poland and 30 sedentary-lifestyle control subjects) in the follicular phase of their menstrual cycle were exposed to mental arithmetic tasks as an experimental imitation of the stressor. Volleyball players were significantly taller than sedentary individuals (177.1 ± 3.4 cm vs. 173.3 ± 3.4 cm, respectively, p = 0.034), but did not differ in weight (73.6 ± 5.2 kg vs. 70 ± 4.23 kg, respectively, p = 0.081), body mass index (BMI) (23.5 ± 1.13 vs. 24.1 ± 1.45, respectively, p = 0.060), and age (22 ± 1.11 vs. 23 ± 1.14 years, respectively, p = 0.2). Their stress responses were assessed through self-reported anxiety levels and physiological measurements of salivary cortisol concentrations and heart rate (HR). Results: For HR, significant effects of time (F_(2,120) = 21.34, p < 0.001, η² = 0.26) were found, but not for training status (F_(1,60) = 2.69, p = 0.106, η² = 0.04). For cortisol levels, the analysis showed the main effects of time (F_(3,180) = 11.73, p < 0.001, η² = 0.16) and training status (F_(1,60) = 4.69, p = 0.034, η² = 0.07) and a significant interaction between training status and time (F_(3,180) = 3.07, p = 0.029, η² = 0.05). Post-hoc analyses showed higher cortisol concentrations among volleyball players following the math task (all p < 0.001), as well as higher cortisol concentrations in S2, S3, and S4 compared to S1 in volleyball players (all p < 0.001). We observed also a significant increase in state anxiety in both groups (all p < 0.001), but no differences in state anxiety levels between groups. Conclusion: Female volleyball players may not differ in subjective graduation of stressors; however, exposure to training-based stressors seems to promote cortisol response to the anticipated stressor.

Transcathether aortic valve implantation with the new repositionable self-expandable Medtronic Evolut R vs. CoreValve system: evidence on the benefit of a meta-analytical approach

AIMS

To compare transcatheter aortic valve replacement TAVR with self-expandable first-generation Medtronic CoreValve with new-generation Evolut R devices in patients with aortic stenosis.

METHODS

Multiple databases were screened for all available reports directly or indirectly comparing CoreValve vs Evolut R. Primary endpoint was device success. Procedural, functional and clinical outcomes were assessed as well.

RESULTS

Ten retrospective series including 12 294 pts. were found. Overall device success rate was 95.5% and was statistically higher in the Evolut R treated patients as compared with CoreValve: 96.6 vs. 94.8%, respectively; RR (risk ratio) 95%CIs (confidence intervals): 1.02 (1.00-1.04); P = 0.01. There were no statistical differences with regard to postoperative mean aortic gradients 8.5 +/- 5.3 vs 7.9 +/- 4.6 with Evolut R and CoreValve. Evolut R valve demonstrated nearly 50% reduction of the risk for moderate-to-severe paravalvilar leak 0.55 (0.39-0.79); P = 0.001; 60% statistically significant lower risk of developing myocardial injury 0.40 (0.22-0.72); P = 0.002 and numerical reductions in the risk of acute kidney injury, vascular complications and bleeding. Together with significantly reduced risk of permanent pacemaker implantation (0.80 [0.67-0.96]; P = 0.02) the above benefits were associated with 40% reduction in the risk of 30-day all-cause mortality with Evolut R as compared to CoreValve: 0.60 (0.37-1.00); P = 0.05.

CONCLUSIONS

The use of new-generation Evolut R was associated with improved procedural, functional and clinical outcomes compared with the CoreValve device.

Three-vessel coronary artery disease may predict changes in biochemical brain injury markers after off-pump coronary artery bypass grafting. J Zhejiang Univ Sci B 2019;19:735-738. [PMID: 30178640 PMCID: PMC6137419 DOI: 10.1631/jzus.b1700553]

Neurological injury is a frequent and important complication of coronary artery bypass grafting (CABG). Several risk factors for this type of sequela have been identified, among them aortic arch atherosclerosis. Our previous study indicated that atherosclerotic burden in coronary arteries may likewise predict postoperative neurological complications (Pawliszak et al., 2016b). We assessed the severity of this condition by using the SYNTAX score calculator. However, diagnosing angiographic three-vessel coronary artery disease (3VD) could be an even simpler method of achieving this goal.

Large Extracellular Vesicles: Have We Found the Holy Grail of Inflammation?

The terms microparticles (MPs) and microvesicles (MVs) refer to large extracellular vesicles (EVs) generated from a broad spectrum of cells upon its activation or death by apoptosis. The unique surface antigens of MPs/MVs allow for the identification of their cellular origin as well as its functional characterization. Two basic aspects of MP/MV functions in physiology and pathological conditions are widely considered. Firstly, it has become evident that large EVs have strong procoagulant properties. Secondly, experimental and clinical studies have shown that MPs/MVs play a crucial role in the pathophysiology of inflammation-associated disorders. A cardinal feature of these disorders is an enhanced generation of platelets-, endothelial-, and leukocyte-derived EVs. Nevertheless, anti-inflammatory effects of miscellaneous EV types have also been described, which provided important new insights into the large EV-inflammation axis. Advances in understanding the biology of MPs/MVs have led to the preparation of this review article aimed at discussing the association between large EVs and inflammation, depending on their cellular origin.

Lack of correlation between pollen aperture number and environmental factors in pansies (Viola L., sect. Melanium Ging.) - pollen heteromorphism re-examined

The development of different pollen morphs by one specimen - pollen heteromorphism - occurs in ca. one-third species of the genus Viola. Melanium section species (pansies) stand out in producing the widest range of apertures among Viola species. Aperture number decreases with elevation increase, and faster germination of five-aperturate pollen as compared with three-aperturate has previously been postulated. We re-examined pollen heteromorphism in the context of its viability, and made correlations with elevation (>1500 m a.s.l. versus <1500 m a.s.l.), soil type (metalliferous versus non-metalliferous; MET versus NMET) and chromosome number based on selected study criteria of ca. 20% karyologically and morphologically strongly differentiated but genetically closely related pansies. A total of 79% of analysed species were heteromorphic, forming three- to six-colp or ate pollen per individual flower. Mean aperture number and pollen viability were not affected by soil type (MET versus NMET). Mean aperture number was also not influenced by elevation or species chromosome number. Positive correlations were established between aperture number and pollen viability, negative between pollen viability and elevation (increasing altitude of 100 m decreased pollen viability by 0.4%) and lack of correlation between chromosome number and pollen viability. The varied frequencies of different pollen morphs among species are not under the general pressure of ecological conditions, as previously postulated for the species of Melanium section. Rather, this trait in pansies, similar to other floral characters (e.g. long, curved nectar spur, 'landing platform', posterior petals with nectar guides), is adaptive but dependent on the breeding system (inbreeding versus outbreeding) of the individual species.

Bone morphogenetic protein 6-a possible new player in pathophysiology of heart failure

Derangement of bone morphogenetic protein (BMP) signalling was observed in cardiovascular disorders. The present study assesses the diagnostic and prognostic value of BMP6 plasma concentration in chronic heart failure (CHF). 130 CHF patients and 32 controls participated in the study. BMP6 plasma level was measured at baseline. During 12-month follow-up death and hospitalisation with CHF exacerbation were recorded. BMP6 was significantly increased in CHF patients with highest concentration in most advanced disease. Individuals with pulmonary congestion or peripheral oedema had higher levels of BMP6 than isovolemic patients. BMP6 was not a predictor of all-cause mortality or CHF hospitalisation. BMP6 may be involved in pathophysiology of systolic CHF. BMP6 plasma level is related to the disease severity and signs of exacerbation.

No evidence of contemporary interploidy gene flow between the closely related European woodland violets Viola reichenbachiana and V. riviniana (sect. Viola, Violaceae)

Viola reichenbachiana (2n = 4x = 20) and V. riviniana (2n = 8x = 40) are closely related species widely distributed in Europe, often sharing the same habitat throughout their overlapping ranges. It has been suggested in numerous studies that their high intraspecific morphological variability and plasticity might have been further increased by interspecific hybridisation in contact zones, given the sympatry of the species and the incomplete sterility of their hybrid. The aims of this study were to: (i) confirm that V. reichenbachiana and V. riviniana have one 4x genome in common, and (ii) determine the impact of hybridisation and introgression on genetic variation of these two species in selected European populations. For our study, we used 31 Viola populations from four European countries, which were analysed using AFLP and sequencing of a variable plastid intergenic spacer, trnH-psbA. Our analysis revealed that V. reichenbachiana exhibited larger haplotype diversity, having three species-specific haplotypes versus one in V. riviniana. The relationships among haplotypes suggest transfer of common haplotypes into V. riviniana from both V. reichenbachiana and hypothetically the other, now extinct, parental species. AFLP analysis showed low overall genetic diversity of both species, with V. riviniana showing higher among-population diversity. None of the morphologically designated hybrid populations had additive AFLP polymorphisms that would have indicated recent hybridisation. Also, kinship coefficients between both species did not indicate gene flow. V. riviniana showed significant population subdivision and significant isolation by distance, in contrast to V. reichenbachiana. The results indicate lack of gene flow between species, high influence of selfing on genetic variability, as well as probably only localised introgression toward V. riviniana.

Assessment of the Procoagulant Activity of Microparticles and the Protein Z System in Patients Undergoing Off-Pump Coronary Artery Bypass Surgery

To understand the coagulation changes after off-pump coronary artery bypass (OPCAB) surgery, we evaluated the procoagulant activity of microparticles (MPs) and microparticles exposing tissue factor (MPs-TF), together with the levels of total tissue factor (TF), protein Z (PZ), protein Z-dependent protease inhibitor (ZPI), and factor X (FX) before (first day) and 1 week after surgery (seventh day) in plasma samples from 30 patients. Twenty healthy controls were also included. Compared to the controls, patients scheduled for surgery had significantly higher MPs-TF procoagulant activity and lower TF levels ( P = .0006, P = .02, respectively). In the whole cohort, median procoagulant activity of MPs-TF and median levels of TF and ZPI were significantly lower ( P = .02, P = .0003, and P = .004, respectively), while median levels of PZ and FX were significantly higher ( P = .02 and P = .002, respectively) on the seventh day compared to the first day. Our results suggest that OPCAB surgery has a significant effect on the procoagulant activity of MPs-TF and the PZ system.

Haemostatic factors do not account for worse outcomes from ischaemic stroke in patients with higher C-reactive protein concentrations

Background Although the role of microparticles was recently implicated in stroke pathophysiology, the association between microparticles and inflammation is still not fully understood. The aim of this cohort study of 66 patients was to assess a relation between haemostatic factors, C-reactive protein and clinical outcome of ischaemic stroke. Methods Plasma microparticles procoagulant activity, concentrations of tissue factor-bearing microparticles, tissue factor and tissue factor pathway inhibitor in ischaemic stroke patients were determined with enzyme-linked immunosorbent assays at the time of initial diagnosis, along with serum C-reactive protein concentrations. Patients were divided into two groups depending on their C-reactive protein concentrations (C-reactive protein <3 mg/L; n = 28 vs. C-reactive protein ≥3 mg/L; n = 38). The analysed clinical outcome measures included the National Institutes of Health Stroke Scale and the Barthel Index. Results The two C-reactive protein groups did not differ significantly in terms of microparticles procoagulant activities, tissue factor-bearing microparticles, tissue factor and tissue factor pathway inhibitor concentrations. A significant correlation was observed between tissue factor pathway inhibitor and National Institutes of Health Stroke Scale score at admission ( R = 0.3, P = 0.03). Patients with C-reactive protein ≥3 mg/L presented with significantly higher National Institutes of Health Stroke Scale scores (median, 9.00 vs. 5.50, P = 0.002) and lower Barthel Index scores (median, 20.00 vs. 65.00, P = 0.002) than individuals with C-reactive protein <3 mg/L. The C-reactive protein concentrations correlated positively with National Institutes of Health Stroke Scale scores ( R = 0.3, P = 0.02) and inversely with Barthel Index scores ( R = - 0.4, P = 0.002). Conclusions Altogether, these findings imply that haemostatic parameters (microparticles, tissue factor-bearing microparticles, tissue factor, tissue factor pathway inhibitor) do not account for elevated C-reactive protein concentrations in ischaemic stroke patients.

Assessing Circulating Factor VIIa-Antithrombin Complexes in Acute Ischemic Stroke: A Pilot Study

AIM

The goal of this study was to determine the levels of factor VII (FVII), factor VIIa-antithrombin complexes (FVIIa-AT), total tissue factor (TF), and tissue factor-bearing microparticles (MPs-TF) in patients with acute ischemic stroke. Further, we sought evidence of an association between hemostatic markers, time of blood sampling, type of treatment, and patient outcomes.

METHODS

Venous blood samples were collected from 33 patients on the first day and on the seventh day after stroke diagnosis. Age-matched controls were also included (n = 20). Plasma levels of FVII, FVIIa-AT, total TF, and MPs-TF were measured by enzyme-linked immunosorbent assay. We divided patients into 2 groups: thrombolysis group (n = 13) and nonthrombolysis group (n = 20). Furthermore, evaluation of the National Institutes of Health Stroke Scale and the Barthel Index was performed on the first day and the seventh day.

RESULTS

Patients with ischemic stroke showed significantly lower plasma FVII, FVIIa-AT, and total TF levels than controls (median, 112.25% vs 132.05%, P = .004; 107.97 pmol/L vs 154.94 pmol/L, P < .001; 81.74 pg/mL vs 105.71 pg/mL, P < .001, respectively). In contrast, levels of plasma MPs-TF were significantly higher in patients with stroke compared to healthy controls (1.60 pg/mL vs 0.74 pg/mL, P < .001). Additionally, the thrombolysis group had lower FVII levels on the seventh day compared to the first day (median, 109.80% vs 115.74%, P = .04).

CONCLUSION

Factor VII, FVIIa-AT, and total TF are decreased, while MPs-TF are elevated in patients with ischemic stroke. We observed a slight but significant effect of alteplase on FVII plasma levels.

Hepcidin Levels Are Increased in Patients with Acute Ischemic Stroke: Preliminary Report

BACKGROUND

Our current understanding of iron balance in acute ischemic stroke (AIS) is still limited. The objective of this study was to evaluate levels of iron homeostasis proteins-hepcidin (25-amino acid form) and soluble hemojuvelin (sHJV) together with hepcidin/sHJV ratio (Hepc/sHJV) and soluble transferrin receptor (sTfR) in patients with AIS. In addition, the effect of timing of blood collection, type of stroke treatment, and scores on the National Institutes of Health Stroke Scale were investigated.

METHODS

Participants comprised 31 patients diagnosed with AIS and 20 matched healthy controls. Venous blood samples were drawn on the first day and on the seventh day after stroke onset. Individuals who had experienced a stroke were subdivided according to type of treatment (thrombolysis group, n = 12 versus nonthrombolysis group, n = 19). Plasma hepcidin, sHJV, and sTfR levels were determined by the enzyme-linked immunosorbent assay method.

RESULTS

We found that plasma hepcidin levels were significantly higher in ischemic stroke patients compared with the control group (median, 19.82 versus 12.62 ng/mL, P = .04). Furthermore, levels of hepcidin on the seventh day (1 week after diagnosis) were significantly higher in patients treated with thrombolysis than in patients not treated with thrombolysis (median, 22.16 versus 16.21 ng/mL, P = .04).

CONCLUSIONS

The study provides evidence that AIS is associated with increased hepcidin levels. Stroke treatment may have an influence on hepcidin synthesis.

Tissue-factor-bearing microparticles (MPs-TF) in patients with acute ischaemic stroke: the influence of stroke treatment on MPs-TF generation

BACKGROUND AND PURPOSE

Stroke is an important cause of death and disability throughout the world. Microparticles play a cardinal role in vascular hemostasis. The primary aim of this study was to evaluate the procoagulant activity of microparticles and levels of tissue-factor-bearing microparticles (MPs-TF), tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in patients with acute ischaemic stroke.

METHODS

Seventy-three patients with a diagnosis of acute ischaemic stroke were included. Venous blood samples were drawn on the first day and the seventh day after stroke onset. Plasma microparticles, MPs-TF, TF and TFPI were determined by enzyme-linked immunosorbent assay. Assessment variables were timing of blood collection, type of stroke treatment, presence or absence of diabetes mellitus and hypertension, and scores on the National Institutes of Health Stroke Scale together with scores on the modified Rankin Scale.

RESULTS

Whilst MPs-TF and TFPI levels of stroke subjects were significantly higher (median, 1.63 vs. 0.73 pg/ml; median, 114.26 vs. 78.60 ng/ml, respectively), TF levels in the plasma of stroke patients were significantly lower (median, 82.27 vs. 97.80 pg/ml) than those of healthy individuals. Lower levels of TF were detected in patients with severe stroke in comparison with patients with mild stroke. Moreover, the data also showed that in stroke patients not treated with alteplase the activity of microparticles was significantly higher 1 week after diagnosis in comparison with the activity at the time of diagnosis.

CONCLUSION

Our findings suggest that patients with acute ischaemic stroke have increased generation of MPs-TF. Nevertheless, further studies are needed in order to confirm such inference.

Morphological versus genetic diversity of Viola reichenbachiana and V. riviniana (sect. Viola, Violaceae) from soils differing in heavy metal content

Morphological characters, AFLP markers and flow cytometry were used to investigate the morphological and genetic variability and differentiation of Viola reichenbachiana and V. riviniana in non-metallicolous (NM) and metallicolous (M) populations. The aims were to clarify the taxonomic status of plants occurring in ore-bearing areas, to determine any relationship in V. reichenbachiana and V. riviniana from sites not polluted with heavy metals, and to examine the genetic variability and differentiation of M and NM populations of both species. Multivariate analyses based on morphological characters showed significant differences between V. reichenbachiana and V. riviniana from non-polluted sites, high levels of intra- and inter-population variability, and the occurrence of inter-specific hybrids. Plants from M populations showed hybrid characters but also fell within the range of V. riviniana or V. reichenbachiana. There were no significant differences in relative genome size between plants from polluted areas and V. riviniana from NM populations. Bayesian analysis of population genetic structure based on AFLP markers distinguished two main groups: V. reichenbachiana and V. riviniana together with the M populations. That analysis also revealed the occurrence of populations of inter-specific hybrids from non-polluted areas. Further Bayesian analysis of V. riviniana including NM and M populations separated all the studied M populations from NM populations. We conclude that plants forming the M populations are well adapted to a metal-polluted environment, and could be considered as stabilised introgressive forms resulting from unidirectional (asymmetric) introgression toward V. riviniana.