Identification of early risk factors for anti-citrullinated-protein-antibody positive rheumatoid arthritis-a prospective cohort study.

OBJECTIVE: Individuals positive for anti-cyclic-peptide-antibodies (anti-CCP) and musculoskeletal complaints (MSK-C) are at risk for developing rheumatoid arthritis (RA). In this study we aimed to investigate factors involved in arthritis progression. METHODS: Anti-CCP2-positive individuals with MSK-C referred to a rheumatologist were recruited. Individuals lacked arthritis at clinical and ultrasound examination and were followed for ≥three years or until clinical arthritis diagnosis. Blood samples from inclusion were analyzed for; nine anti-citrullinated-protein-antibody (ACPA) reactivities (citrullinated α-1-enolase, fibrinogen, filaggrin, histone, vimentin and tenascin peptides); 92 inflammation-associated proteins; and HLA-shared epitope alleles. Cox regression was applied to the data to identify independent predictors in a model. RESULTS: 267 individuals were included with median follow up of 49 months (IQR: 22-60). 101 (38%) developed arthritis after median 14 months (IQR: 6-27). The analysis identified that presence of at least one ACPA reactivity (HR 8.0, 95% CI 2.9-22), ultrasound detected tenosynovitis (HR 3.4, 95% CI 2.0-6.0), IL6 levels (HR 1.5, 95% CI 1.2-1.8) and IL15-Rα levels (HR 0.6, 95% CI 0.4-0.9) are significant independent predictors for arthritis progression in a prediction model (Harrell's C 0.76 [SE 0.02], AUC 0.82 [95% CI 0.76-0.89], cross-validated AUC 0.70 [95% CI 0.56-0.85]). CONCLUSION: We propose a high-Risk-RA phase characterized by presence of ACPA reactivity, tenosynovitis, IL6, and IL15-Rα and suggest that these factors need to be further investigated for their biological effects and clinical values, to identify individuals at particular low risk and high risk for arthritis progression.

Impaired Fibrinolysis in the Antiphospholipid Syndrome.

The pathogenesis of the antiphospholipid syndrome (APS) is complex and involves the persistent presence of antiphospholipid antibodies (aPL) in the bloodstream causing a prothrombotic condition. aPL induce excessive activation of the endothelium, monocytes, and platelets in consort with aberrations in hemostasis/clotting, fibrinolytic system, and complement activation. Impaired fibrinolysis has been found in APS patients with thrombotic as well as obstetric manifestations. Increased levels of plasminogen activator inhibitor-1 and thrombin-activatable fibrinolysis inhibitor, together with the presence of aPL against annexin-2, tissue-type plasminogen activator, and plasminogen contribute to the compromised fibrinolytic activity in these patients. Furthermore, unfavorably altered fibrin morphology, less amenable to fibrinolysis, has been proposed as a novel prothrombotic mechanism in APS. This review aims to summarize the present knowledge of the mechanisms involved in impaired fibrinolysis in APS patients. We also present a case from clinical practice as an illustration of fibrinolysis impairment in APS patients from a real-life setting.

The Silence Speaks, but We Do Not Listen: Synonymous c.1824C>T Gene Variant in the Last Exon of the Prothrombin Gene as a New Prothrombotic Risk Factor.

BACKGROUND: Thrombosis is a major global disease burden with almost 60% of cases related to underlying heredity and most cases still idiopathic. Synonymous single nucleotide polymorphisms (sSNPs) are considered silent and phenotypically neutral. Our previous study revealed a novel synonymous FII c.1824C>T variant as a potential risk factor for pregnancy loss, but it has not yet been associated with thrombotic diseases. METHODS: To determine the frequency of the FII c.1824C>T variant we have sequenced patients' DNA. Prothrombin RNA expression was measured by quantitative PCR. Functional analyses included routine hemostasis tests, western blotting and ELISA to determine prothrombin levels in plasma, and global hemostasis assays for thrombin and fibrin generation in carriers of the FII c.1824C>T variant. Scanning electron microscopy was used to examine the structure of fibrin clots. RESULTS: Frequency of the FII c.1824C>T variant was significantly increased in patients with venous thromboembolism and cerebrovascular insult. Examination in vitro demonstrated increased expression of prothrombin mRNA in FII c.1824T transfected cells. Our ex vivo study of FII c.1824C>T carriers showed that the presence of this variant was associated with hyperprothrombinemia, hypofibrinolysis, and formation of densely packed fibrin clots resistant to fibrinolysis. CONCLUSION: Our data indicate that FII c.1824C>T, although a synonymous variant, leads to the development of a prothrombotic phenotype and could represent a new prothrombotic risk factor. As a silent variant, FII c.1824C>T would probably be overlooked during genetic screening, and our results show that it could not be detected in routine laboratory tests.

Pancreatic Polypeptide-Secreting Tumour of the Proximal Pancreas (PPoma)-Ultra Rare Pancreatic Tumour: Clinically Malign, Histologically Benign.

Background and objectives: Here we report a rare case of a pancreatic polypeptide-secreting tumour (PPoma) discovered by accident during an autopsy. These PPomas occur in less than 2% of all pancreatic neoplasms and are almost exclusively silent, i.e., they are non-functional. Symptoms arising from PPoma are due to its compression of surrounding tissue. Materials and methods: The autopsy was performed on a 68-year-old male diagnosed with multiple endocrine neoplasm type 1 (MEN1) due to the patient's sudden death. Results: A solitary, densely fibrotic, pink-brown tumour, 18 mm in size tumorous mass, was localised in the head of the pancreas. Microscopically, the tumour had a glandular structure with a tubuloacinar arrangement of the cells. Immunohistochemically, we detected strong PP (pancreatic polypeptide) intracytoplasmic activity and negative glucagon activity. The PPoma was located in the head of the pancreas, likely resulting in the obstruction of the main pancreatic and common bile duct. Conclusions: To the best of our knowledge, this is the first report suggesting the association of PPomas with MEN1. Also, the PPoma could be the cause of acute hemorrhagic pancreatitis due to its location.

The expression of microvesicles in the blood of patients with Graves' disease and its relationship to treatment.

OBJECTIVE: Graves' disease (GD) is an autoimmune disease characterized by the presence of circulating autoantibodies against thyroid-stimulating hormone (TSH) receptor. Despite extensive research, the pathogenic mechanisms remain unclear. Immune responses associated with the disease may lead to cell activation/apoptosis and the release of microvesicles (MVs) into the circulation. MVs can display biological activities which may aggravate GD further. We studied immune mechanisms in GD by investigating the numbers and phenotype of circulating MVs in patients before and after antithyroid therapy with thiamazole. PATIENTS AND MEASUREMENTS: Samples were obtained from 15 patients with GD in the acute phase of hyperthyroidism and following 17-26 months treatment and 14 healthy controls. MVs from platelets, endothelial cells and monocytes exposing inflammation/activation markers (P-selectin, CD40 ligand, E-selectin and HMGB1) and MVs containing nuclear molecules were measured with flow cytometry. RESULTS: Patients had elevated baseline values of MVs (P < 0·001 for all types of MVs), while the levels decreased during thiamazole treatment (P < 0·05 for all types of MVs). The majority of MV populations remained, however, significantly higher in patients after treatment compared to levels in controls. CONCLUSIONS: GD patients have elevated levels of MVs that carry molecules with potential biological activities. MVs are significantly reduced after antithyroid treatment with thiamazole but still higher compared to levels in healthy controls. Assessment of MV levels and pattern may therefore provide additional information on underlying immune disturbances not obtained by measurements of hormone levels alone.

Precision touch DNA sampling on plastic bag knots for improved profiling of packer and holder contributions.

In forensic DNA analysis, evidence sampling stands as a pivotal step setting the ground for the quality of the forensic profiling. The collection of touch DNA from objects, when guidelines are scarce or absent, is usually governed by ad hoc decisions based on the available case circumstances. In our laboratory, in the context of illicit drug-related crimes, similar objects are frequently encountered, offering an opportunity for the standardization of evidence treatment. This study aims to develop an effective method for sampling touch DNA from knots on plastic bags. We examine both the exposed and hidden areas of knots, considering the latter as "protected" zones less likely to accumulate biological material during subsequent handling. The study contrasts a single sample method (whole knot surface sampling, Method 1) with dual-sample methods that separate exterior (exposed) and interior (hidden) surfaces of the knot. Notably, our study consistently reveals higher DNA yields from exterior surfaces of the knots as opposed to interior samples. Importantly, our findings demonstrate that utilizing a single sample may produce DNA profiles that are not interpretable, while employing a dual-sample approach may allow for the differentiation between the genetic contributions of the person who tied the knot, the packer, from the person who held the package, the holder. We have refined the dual-sample method to reduce holder DNA in the interior sample while maintaining it on the exterior, also allowing the packer's DNA to be detected on both surfaces. We explore four dual-sample collection methods. Method 2 involves taking the first sample from the exterior and the second from the interior of an untied knot. Method 3 visually differentiates between the original exposed and hidden surfaces for precise sampling. Method 4 employs tools to open the knot for interior sampling. Method 5 uses Diamond dye to highlight cell-free DNA on both surfaces before sampling. In conclusion, this study not only clarifies the complex dynamics of touch DNA transfer and collection on plastic bag knots, but also offers insights into standardizing evidence collection in similar cases.

Extracellular vesicles in plasma and cerebrospinal fluid in patients with COVID-19 and neurological symptoms.

INTRODUCTION: Increased levels of extracellular vesicles (EVs) are associated with haemostatic disturbances in various clinical settings. However, their role in COVID-19 patients is still not fully clear. In the present study we investigated EVs in plasma from patients with COVID-19 and neurological symptoms in relation to the activation of coagulation. METHODS: Nineteen COVID-19 patients with neurological symptoms and twenty-three aged-matched healthy individuals were included. Global coagulation assays were performed and levels of EVs were determined by flow-cytometry in plasma and cerebrospinal fluid (CSF). RESULTS: A procoagulant state characterized by significantly increased overall coagulation- (OCP) and overall haemostatic potential (OHP), diminished overall fibrinolytic potential (OFP) together with a denser fibrin structure was found in patients with COVID-19. Flow cytometry revealed elevated levels of plasma circulating EVs derived from neutrophils (MPO+) and platelets (CD61+), as well as EVs expressing phosphatidylserine (PS+) and complement component C5b-9 (TCC+) in patients with COVID-19 compared with controls. The concentrations of PS+, CD61+ and TCC+ EVs were positively correlated with OCP and OHP in COVID-19 patients. Moreover, we identified CD61+, MPO+ and endothelial cell-derived EVs, as well as EVs exposing PS and TCC in the CSF of patients suffering from neurological symptoms during COVID-19. CONCLUSION: The unique finding in this study was the presence of EVs in the CSF of COVID-19 patients with neurologic manifestations as well as higher expression of complement protein on circulating plasma EVs. EVs may indicate blood-brain barrier damage during SARS-COV-2 infection.

Development of QSAR model based on Monte Carlo optimization for predicting GABAA receptor binding of newly emerging benzodiazepines.

Benzodiazepines and their derivatives belong to a category of new psychoactive substances that have been introduced into the continually expanding illicit market. However, there is a notable absence of available pharmacological data for these substances. To gain a deeper understanding of their pharmacology, we employed the Monte Carlo optimization conformation-independent method as a tool for developing QSAR models. These models were built using optimal molecular descriptors derived from both SMILES notation and molecular graph representations. The resulting QSAR model demonstrated robustness and a high degree of predictability, proving to be very reliable. Moreover, we were able to identify specific molecular fragments that exerted both positive and negative effects on binding activity. This discovery paves the way for the swift prediction of binding activity for emerging benzodiazepines, offering a faster and more cost-effective alternative to traditional in vitro/in vivo analyses.

Augmented thrombin formation is related to circulating levels of extracellular vesicles exposing tissue factor and citrullinated histone-3 in anti-neutrophil cytoplasmic antibody-associated vasculitides.

Objectives: To study circulating myeloperoxidase (MPO)-positive extracellular vesicles (MPO+EVs) exposing citrullinated histone-3 (H3Cit), tissue factor (TF), and plasminogen (Plg) in association to thrombin generation in patients with anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV). Methods: We have involved well-characterized patients with AAV together with population-based controls. Flow cytometry was used to assess the levels of MPO+EVs in citrated plasma. MPO+EVs were phenotyped by anti-MPO-antibodies together with anti-CD142 (anti-TF), anti-H3Cit, and anti-Plg antibodies. A modified Calibrated Automated Thrombogram (CAT) assay was utilized to measure thrombin generation in plasma initiated by EVs-enriched pellets. The activity of AAV was evaluated with the Birmingham Vasculitis Activity Score (BVAS). Results: This study comprised 46 AAV patients, 23 in the active stage of the disease and 23 in remission, as well as 23 age- and sex matched population-based controls. Augmented levels of all investigated MPO+ EVs were found in active AAV patients in comparison to the subgroup of patients in remission and controls. Thrombin generation, measured by endogenous thrombin potential (ETP) and peak of thrombin formation, was higher in plasma when triggered by EVs-enriched pellet from AAV patients. ETP and peak were associated with the levels of MPO+TF+ and MPO+H3Cit+ EVs. Additionally, MPO+TF+ EVs correlated with the disease activity evaluated with BVAS. Conclusion: Augmented thrombin generation is found in AAV patients regardless of disease activity and is associated with higher exposure of TF and H3Cit on MPO+EVs. This may contribute to the increased risk of thrombosis seen in AAV patients.

Hypoplastic arteries of the cerebral arterial ring in the blind spot of computed tomography angiography.

BACKGROUND: Some variations of the cerebral arterial circle (CAC) are associated with an increased risk for the development of various pathological conditions. This paper aimed to determine the prevalence of hypoplastic arteries of CAC and to emphasize the limited possibility of their visualization by computed tomography angiography (CTA). MATERIALS AND METHODS: The research was performed on 400 adult cadavers by macro- and microdissection of the cerebral arteries. Each case was photographed and the diameter of the arteries was measured digitally, by analyzing photographs of the bases of the brain in the ImageJ program. RESULTS: The largest prevalence of artery diameter <1mm (<0.6mm) in CAC had the posterior communicating artery (PCoA). PCoA on the left side was hypoplastic in 44.9% (11.4%) of cases, while the same artery on the right side was hypoplastic in 44.3% (6.6%) of cases. The posterior cerebral artery was hypoplastic on the left side in 3% (0.6%) and on the right side in 4.2% (0.6%) of cases. The anterior cerebral artery had a hypoplastic caliber only on the right side in 2.4% (0.6%) of the cases, while the internal carotid arteries did not have a diameter <1mm in any case. The anterior communicating artery showed the greatest variability in morphology. Studies on CTA describe the occurrence of aplasia in a statistically significantly higher percentage, and the occurrence of hypoplastic arteries in a statistically significantly lower percentage compared to studies on cadavers. CONCLUSIONS: Due to significant differences between cadaveric and radiological studies, it is necessary to analyze their results regarding arterial hypoplasia and aplasia separately. A diameter of less than 1 mm has been suggested as a criterion for arterial hypoplasia.

Impaired Fibrinolysis Is Linked With Digital Vasculopathy and Onset of New Digital Ulcers in Systemic Sclerosis.

OBJECTIVE: To assess thrombin generation, fibrin formation, and structure together with the fibrinolytic status in patients with systemic sclerosis (SSc) in relation to the occurrence of digital ulcers (DUs) during the course of disease. METHODS: We studied variables of endothelial dysfunction, thrombin generation, overall hemostatic potential, and fibrin clot turbidity in plasma from 58 patients with SSc (39 with DU history and 19 DU-naïve) and 46 matched healthy controls (HCs). Fibrin structure was visualized using scanning electron microscopy (SEM). Finally, 39 patients with a history of DUs were followed for 1.5 years and the predictive value of all investigated markers for new DU onset was explored. RESULTS: Significantly enhanced endogenous thrombin potential (ETP) and prolonged clot lysis time (CLT) were found in patients with DUs compared to HCs. CLT was prolonged in patients with DUs compared to those without, showing good validity in identifying DUs with an area under the curve of 0.7 (95% CI 0.6-0.8). The levels of ETP and intercellular adhesion molecule 1 were independently associated with CLT. Over the follow-up period, 20 patients developed new DUs. CLT was prolonged (P < 0.001) in patients with new DU episodes, especially those with recurrent DUs. Regression analysis showed that the Raynaud phenomenon visual analog scale and CLT were predictors of new DUs (OR 1.1, 95% CI 1.0-1.1 and OR 1.2, 95% CI 1.1-1.3, respectively). SEM confirmed denser fibrin clots in patients with new DUs. CONCLUSION: Our results suggest that impaired fibrinolysis might have an emerging role in underlying digital vasculopathy and its progression in SSc.

Fatal Acute Hemorrhagic Encephalomyelitis and Antiphospholipid Antibodies following SARS-CoV-2 Vaccination: A Case Report.

Acute hemorrhagic encephalomyelitis (AHEM) is a rare hyperacute form of acute disseminated encephalomyelitis (ADEM). The disease is characterized by fulminant inflammation and demyelination in the brain and spinal cord and is often preceded by an infection or vaccination. This case report presents a 53-year-old male with rheumatoid arthritis and ongoing treatment with methotrexate and etanercept who developed fatal AHEM following the second dose of the COVID-19 vaccine. The disease course was complicated by multiorgan thromboembolic disease and the presence of high/moderate levels of cardiolipin IgG antibodies and anti-beta-2 glycoprotein 1 IgG antibodies suggesting a possible antiphospholipid syndrome. Treatment with immunosuppressive therapies failed to improve the course. The report comprises comprehensive clinical, neuroimaging, and neuropathological findings. The case highlights diagnostic challenges in a patient with several preceding risk factors, including autoimmune disease, immunotherapy, and vaccination, with possible pathophysiological implications. The temporal association with the COVID-19 vaccination may suggest possible causality although evidence cannot be ascertained. Reporting possible adverse events following COVID-19 vaccination is important to identify at-risk populations and to accomplish control of the current pandemic.

Increased Expression of Extracellular Vesicles Is Associated With the Procoagulant State in Patients With Established Rheumatoid Arthritis.

This study sought to identify different subpopulations of extracellular vesicles (EVs) in plasma from female patients with established rheumatoid arthritis (RA) in relation to the activation of coagulation and fibrin formation in these patients. Forty women were included in the study, 20 patients and 20 age-matched healthy controls. The mean disease duration in patients was 13.0 (5.0-25.0) years, with medium to high disease activity despite ongoing treatment with low-dose prednisolone and methotrexate. There were no differences between the investigated groups regarding the presence of traditional cardiovascular risk factors. The concentration of phosphatidylserine-positive (PS+) EVs; platelet (CD42a+), leucocyte (CD45+), monocyte (CD14+), and endothelial (CD144+)-derived EVs; and EVs-expressing tissue factor (CD142+), P-selectin (CD62P+), and E-selectin (CD62E+) were determined by flow cytometry analysis. Overall hemostasis potential (OHP) was assessed to follow the hemostatic disturbances, including the parameters for overall coagulation potential (OCP) and overall fibrinolytic potential (OFP). Fibrin clot turbidity was measured together with clot lysis time, and scanning electron microscopy was performed. Increased concentrations of PS+, CD42a+, CD142+, CD45+, CD14+, and CD62P+ EVs were found in plasma from patients with RA compared to healthy controls, and the concentrations of PS+, CD42a+, CD14+, and CD62P+ EVs were positively correlated with the inflammatory parameters in RA patients. Positive correlations were also found between the levels of PS+ and CD42a+ EVs and OCP as well as between the levels of PS+, CD42a+, and CD62P+EVs and OHP. The levels of PS+, CD42a+, CD14+, CD62P+, and CD62E+ EVs were negatively correlated with OFP. Elevated levels of circulating EVs of different cell origins were found in patients with established RA, in relation to the inflammatory burden and coagulation activation in the disease.

The Influence of Menopause and Inflammation on Redox Status and Bone Mineral Density in Patients with Rheumatoid Arthritis.

Although oxidative stress is considered to be one of the key pathogenic factors in rheumatoid arthritis (RA), there is insufficient knowledge regarding the impact of menopause on redox status in this population. Thus, this study is aimed at assessing the influence of menopause within healthy women and within RA patients as well as the impact of RA in premenopausal and postmenopausal women on redox status, with special reference to bone mineral density (BMD). A total of 90 women were included in the study, 42 with RA and 48 age-matched healthy controls. They were divided into subgroups according to the presence of menopause. Following oxidative stress parameters were measured spectrophotometrically: index of lipid peroxidation (measured as TBARS), nitrites (NO2 -), superoxide anion radical (O2 -), hydrogen peroxide (H2O2), superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH). BMD was assessed by using a dual-energy X-ray absorptiometry scanner. Comorbidities and drug history were recorded. The levels of H2O2 and TBARS were elevated in patients with RA, while NO2 - and O2 - increased in healthy women, both in premenopausal and postmenopausal groups. SOD activity decreased in postmenopausal RA patients. BMD was reduced in postmenopausal RA women. There was a correlation between NO2 - and O2 - with Health Assessment Questionnaire (HAQ) index in RA patients. Given that postmenopausal state was associated with elevated oxidative stress within healthy women and that menopausal state did not affect redox homeostasis within RA patients, but the redox homeostasis was altered in both RA groups compared to healthy women, it can be presumed that impaired redox status in RA occurred due to presence of the disease, irrespective of age. Moreover, menopause attenuates BMD reduction in women with RA. These results may indicate the need for therapeutic use of antioxidants in the form of supplements in women with RA, regardless of age.

Phosphatidylserine Exposing Extracellular Vesicles in Pre-eclamptic Patients.

Background: Pre-eclampsia (P-EC) is associated with systemic inflammation, endothelial dysfunction and hypercoagulability. The role of extracellular vesicles (EVs) in coagulation disturbances affecting the development and severity of P-EC remains elusive. We aimed to evaluate the concentration of EVs expressing phosphatidylserine (PS) and specific markers in relation to the thrombin and fibrin formation as well as fibrin clot properties, in pregnant women with P-EC in comparison to healthy pregnant women of similar gestational age. Methods: Blood samples of 30 pregnant women diagnosed with P-EC were collected on the morning following admission to hospital and after delivery (mean duration 5 days). The concentration of the PS-exposing EVs (PS+ EVs) from platelets (CD42a+, endothelial cells (CD62E+), and PS+ EVs expressing tissue factor (TF) and vascular cell adhesion molecule 1 (VCAM-1) were measured by flow cytometry. Further phenotyping of EVs also included expression of PlGF. Markers of maternal haemostasis were correlated with EVs concentration in plasma. Results: Preeclamptic pregnancy was associated with significantly higher plasma levels of PS+ CD42a+ EVs and PS+ VCAM-1+ EVs in comparison with normotensive pregnancy. P-EC patients after delivery had markedly elevated concentration of PS+ CD42a+ EVs, CD62E+ EVs, TF+ EVs, and VCAM-1+ EVs compared to those before delivery. Inverse correlation was observed between EVs concentrations (PS+, PS+ TF+, and PlGF+) and parameters of overall haemostatic potential (OHP) and fibrin formation, while PS+ VCAM-1+ EVs directly correlated with FVIII activity in plasma. Conclusion: Increased levels of PS+ EVs subpopulations in P-EC and their association with global haemostatic parameters, as well as with fibrin clot properties may suggest EVs involvement in intravascular fibrin deposition leading to subsequent microcirculation disorders.

The Complex Relationship between C4b-Binding Protein, Warfarin, and Antiphospholipid Antibodies.

BACKGROUND: Low levels of total C4b-binding protein (C4BPt), a circulating inhibitor of the classical/lectin complement pathways, were observed in patients with antiphospholipid antibodies (aPLs) and during warfarin treatment. OBJECTIVES: To investigate the associations between aPL and C4BPt in patients with persistently positive (++) aPL, with/without clinical manifestations and systemic lupus erythematosus (SLE), and in controls. Furthermore, we explored the impact of anticoagulation on C4BPt and in relation to complement activation. METHODS: In a cross-sectional design we investigated defined subgroups: primary (p) antiphospholipid syndrome (APS, N = 67), aPL++ individuals without clinical manifestations (aPL carriers, N = 15), SLE-aPL++ (N = 118, among them, secondary [s] APS, N = 56), aPL negative (-) SLE (SLE-aPL-, N = 291), and 322 controls. Clinical characteristics, including treatment, were tabulated. C4BPt was determined with a magnetic bead method. Complement proteins (C1q, C2, C3, C4, C3a, C3dg, sC5b-9, factor I [FI]) were measured. A mediation analysis was performed to decompose the total effect of aPL++ on C4BPt into the direct and indirect effects of aPL++ through warfarin. RESULTS: Overall, C4BPt is 20% decreased in aPL++ patients, regardless of SLE, APS, clinical manifestations, and aPL profile. C4BPt levels associate positively with complement proteins C1q, C2, C3, and C4, and negatively with complement activation product C3dg. In the SLE group, warfarin treatment contributes to approximately half of the C4BPt reduction (9%) CONCLUSION: Both aPLs and warfarin are associated with C4BPt reduction. Complement activation in aPL++ patients may partly be explained by impaired inhibition through depressed C4BPt levels. Further studies are needed to understand the clinical implications.

The overall hemostasis potential: a laboratory tool for the investigation of global hemostasis.

A simple and rapid global haemostatic assay for determination of the overall hemostasis potential (OHP) in plasma represents a new approach in detecting alterations in the delicate balance between coagulation and fibrinolysis. The assay is based on repeated spectrophotometric registration of the fibrin-aggregation curve in platelet-poor plasma containing small amounts of exogenous thrombin, tissue-type plasminogen activator, and calcium. The overall coagulation potential and overall fibrinolytic potential are supplementary parameters of OHP, providing details of underlying changes in coagulation and/or fibrinolysis. The OHP assay was evaluated in connection with hypercoagulation in normal pregnancy, preeclampsia, some thrombophilias, coronary heart disease, diabetes, stroke, and vascular surgery as well as with hypocoagulability, especially in patients with hemophilia A or B. Preliminary results also indicate the possible usefulness of the assay in monitoring anticoagulant treatments. Large prospective clinical trials are needed before the method can be recommended for routine clinical application.

An excess vessel in the posterior part of the human cerebral arterial circle (CAC): a case series.

BACKGROUND: As a continuation of the previous findings in human fetuses, accidental finding of an accessory vascular component in the posterior part of CAC of human adult cadavers inspired the authors to present and compare its posterior part configuration. CASE PRESENTATION: Examination was carried out on brains of 48 human adult cadavers, routinely dissected at the Institute of Forensic Medicine. The aberrant vessel in the posterior part of four CACs was discovered.Vascular components of the posterior segment of CAC or of the whole CAC were described and photographed. A comparison between fetal and adult cases was also presented. CONCLUSIONS: Based on the fact that the age of the four presented cases ranged from 73 to 84 and based on the causes of their death, we concluded that the angioarchitecture of the posterior part of the CAC is a consequence of the embryonic or primitive arterial stabilization and interaction with normal adult vessels.

Ultrastructural changes in the liver of intravenous heroin addicts.

The ultrastructural research has a decisive role in gathering the knowledge on the liver's response to the influence of some drugs. The aim of the study was to perform an ultrastructural analysis of the liver in chronic intravenous heroin addicts.The study involved the autopsy conducted on 40 bodies of intravenous heroin addicts and 10 control autopsies. The liver tissue was fixed in glutaraldehyde and moulded with epon for investigation purposes of ultrastructural changes. The analysis was performed using the method of transmission electron microscopy.In the group of intravenous heroin addicts, the liver autopsy samples showed degenerative vesicular and fat changes, chronic active and persistent hepatitis, cirrhosis, reduction in the amount of glycogen in hepatocytes, as well as the Kupffer cell's dominant hypertrophy. Various changes occur in organelles, plasma membrane of hepatocytes and biliary channels as well as in the nucleus. The most important ultrastructural findings include: hyperplasia and hypertrophy of the smooth endoplasmic reticulum, which is histologically proven vesicular degeneration of hepatocyte occurring as a result of the increased synthesis of enzymes of smooth endoplasmic reticulum due to chronic intravenous heroin intake, and the presence of continuous basal membrane followed by transformation of the sinusoids into capillaries (in the cases of chronic active hepatitis and cirrhosis) which leads to a disorder of microcirculation and further progress of cirrhosis.

Synergistic Effect of Bypassing Agents and Sequence Identical Analogue of Emicizumab and Fibrin Clot Structure in the In Vitro Model of Hemophilia A.

Development of inhibitors to factor VIII (FVIII) occurs in approximately 30% of severe hemophilia A (HA) patients. These patients are treated with bypassing agents (activated prothrombin complex concentrate [aPCC] and recombinant activated FVII-rFVIIa). Recently, a bispecific FIX/FIXa- and FX/FXa-directed antibody (emicizumab) has been approved for the treatment of HA patients with inhibitors. However, the data from clinical studies imply that coadministration of emicizumab and bypassing agents, especially aPCC, could have a thrombotic effect. This study was aimed to address the question of potential hypercoagulability of emicizumab and bypassing agents' coadministration, we have investigated fibrin clot formation and structure in the in vitro model of severe HA after adding sequence-identical analogue (SIA) of emicizumab and bypassing agents. Combined overall hemostasis potential (OHP) and fibrin clot turbidity assay was performed in FVIII-deficient plasma after addition of different concentrations of SIA, rFVIIa, and aPCC. Pooled normal plasma was used as control. The fibrin clots were analyzed by scanning electron microscopy (SEM). OHP and turbidity parameters improved with the addition of aPCC, while therapeutic concentrations of rFVIIa did not show substantial improvement. SIA alone and in combination with rFVIIa or low aPCC concentration improved OHP and turbidity parameters and stabilized fibrin network, while in combination with higher concentrations of aPCC expressed hypercoagulable pattern and generated denser clots. Our in vitro model suggests that combination of SIA and aPCC could potentially be prothrombotic, due to hypercoagulable changes in fibrin clot turbidity and morphology. Additionally, combination of SIA and rFVIIa leads to the formation of stable clots similar to normal fibrin clots.