Efficacy and safety of RD2 Ver.02, a whole blood clot therapy, coupled with a minimally invasive procedure in pilonidal sinus: a phase II study.

BACKGROUND: PNS is caused by an infection in the sacrococcygeal area triggered by hair particle accumulation in skin tunnels, resulting in infection. Surgical options range from simple excision to complex flap constructions. Primary wound healing failure and recurrence rates contribute to the burden of PNS. RD2 Ver.02, a novel autologous whole-blood clot product, demonstrated safety and efficacy in treating complex cutaneous wounds and was investigated for the management of PNS. METHODS: A Phase II open-label, pilot, single-arm prospective study was conducted from May 2021 to May 2023 (Ethics Committee approval #7952-20). Patients with PNS underwent a minimally invasive trephine procedure under local anesthesia followed by RD2 Ver.02 instillation into the cavity. Primary healing was assessed at 3, 6, and 12 months. Secondary outcomes included the collection of adverse events. RESULTS: Overall, 51 patients participated in the study. At 3 months, 42/51 healed (82.4%), 7/51 (13.7%) were granulating but not completely healed, and 2/51 (3.9%) failed to heal. At 6 and 12 months, 46/51 (90.2%) and 42/51 (82.4%) achieved complete healing, respectively. At 6 months, two PNSs recurred after initial healing and an additional four instances of PNS recurrence observed in 12 months, so a total of recurrence in six patients (11.8%). There were five adverse events (AEs) with no severe adverse events. CONCLUSION: RD2 Ver.02 is a safe and effective treatment of PNS when coupled with a minimally invasive trephine PNS procedure. Further comparative studies are needed to fully assess the role of this novel therapy for PNS.

Compare efficacy and safety of autologous blood clot injection with C-clamp vascular closure device in treatment of iatrogenic pseudoaneurysm after femoral artery puncture.

INTRODUCTION: Iatrogenic femoral artery pseudoaneurysm (FAP) is a complication following femoral artery puncture, with an incidence rate of 0.2%-5.5% post-cardiac catheterization procedures. Management typically involves observation or interventional treatments such as ultrasound-guided compression (UGC) or ultrasound-guided thrombin injections. This study compares the efficacy and safety of ultrasound-guided autologous blood clot injection (UGCI) with C-clamp vascular closure device-assisted UGC in treating FAP. MATERIALS AND METHODS: Conducted at a high-volume training and research center, this prospective study enrolled patients with iatrogenic FAP post-femoral artery puncture. Patients were randomized into two treatments: UGC with a C-clamp device or UGCI. Primary endpoints were thrombosis induction within 24 h, average procedure time, and length of hospital stay (LOS). RESULTS: The study included 105 patients with 51 undergoing UGCI and 54 undergoing UGC. UGCI achieved a primary success rate of 96% versus 63% for UGC. The mean procedure duration for UGCI was significantly shorter (22 min) compared with UGC (49 min, p ⩽ 0.0001). LOS was also reduced in the UGCI group (1.5 days) compared to the UGC group (4.5 days). Complication rates were low for both procedures, with one deep vein thrombosis and one infection observed in the UGC group. CONCLUSION: UGCI demonstrated to be a safe, efficient, and faster alternative for treating iatrogenic FAPs with a higher success rate, reduced LOS, and similar low complication rates compared to UGC. This study suggests that UGCI could be considered a preferred method for the management of FAP post-femoral artery catheterization.

Mesoporous silica thin film as effective coating for enhancing osteogenesis through selective protein adsorption and blood clotting.

The role of blood clots in tissue repair has been identified for a long time; however, its participation in the integration between implants and host tissues has attracted attention only in recent years. In this work, a mesoporous silica thin film (MSTF) with either vertical or parallel orientation was deposited on titania nanotubes surface, resulting in superhydrophilic nanoporous surfaces. A proteomic analysis of blood plasma adsorption revealed that the MSTF coating could significantly increase the abundance of acidic proteins and the adsorption of coagulation factors (XII and XI), with the help of cations (Na+, Ca2+) binding. As a result, both the activation of platelets and the formation of blood clots were significantly enhanced on the MSTF surface with more condensed fibrin networks. The two classical growth factors of platelets-derived growth factors-AB and transformed growth factors-ßwere enriched in blood clots from the MSTF surface, which accounted for robust osteogenesis bothin vitroandin vivo. This study demonstrates that MSTF may be a promising coating to enhance osteogenesis by modulating blood clot formation.

Dynamic Perviousness Has Predictive Value for Clot Fibrin Content in Acute Ischemic Stroke.

Dynamic perviousness is a novel imaging biomarker, with clot density measurements at multiple timepoints to allow longer contrast to thrombus interaction. We investigated the correlations between dynamic perviousness and clot composition in the setting of acute ischemic stroke. Thirty-nine patients with large vessel occlusion (LVO) undergoing mechanical thrombectomy (MT) were analyzed. Patients received a three-phase CT imaging pre-thrombectomy and histopathological analysis of retrieved clots. Clot densities for every phase and change in densities between phases were calculated, leading to four patterns of dynamic perviousness: no contrast uptake, early contrast uptake with and without washout and late uptake. Clots were categorized into three groups based on dominant histologic composition: red blood cell (RBC)-rich, fibrin/platelet-rich and mixed. Clot composition was correlated with dynamic perviousness using the Kruskal-Wallis test and Pearson's correlation analysis. The dynamic perviousness categories showed a significant difference between fibrin-rich clots when compared to RBC-rich plus mixed groups. The uptake without washout category had significantly fewer fibrin clots compared to the uptake with washout (p = 0.036), and nearly significantly fewer fibrin clots when compared to the no uptake category (p = 0.057). Contrast uptake with different patterns of contrast washout showed significant differences of the likelihood for fibrin-rich clots.

Using clotted, pelleted blood samples for direct molecular detection of Bartonella spp. in small mammal wildlife surveillance studies.

OBJECTIVE: Bartonella are emerging bacterial zoonotic pathogens. Utilization of clotted blood samples for surveillance of these bacteria in wildlife has begun to supersede the use of tissues; however, the efficacy of these samples has not been fully investigated. Our objective was to compare the efficacy of spleen and blood samples for DNA extraction and direct detection of Bartonella spp. via qPCR. In addition, we present a protocol for improved DNA extraction from clotted, pelleted (i.e., centrifuged) blood samples obtained from wild small mammals. RESULTS: DNA concentrations from kit-extracted blood clot samples were low and A260/A280 absorbance ratios indicated high impurity. Kit-based DNA extraction of spleen samples was efficient and produced ample DNA concentrations of good quality. We developed an in-house extraction method for the blood clots which resulted in apposite DNA quality when compared to spleen samples extracted via MagMAX DNA Ultra 2.0 kit. We detected Bartonella in 9/30 (30.0%) kit-extracted spleen DNA samples and 11/30 (36.7%) in-house-extracted blood clot samples using PCR. Our results suggest that kit-based methods may be less suitable for DNA extraction from blood clots, and that blood clot samples may be superior to tissues for Bartonella detection.

Optimizing inferior vena cava filter design: A computational fluid dynamics study on strut configuration for enhanced hemodynamic performance and thrombosis reduction.

Background and objective: Inferior vena cava filters have been shown to be effective in preventing deep vein thrombosis and its secondary complication, pulmonary embolism, thereby reducing the high mortality rate. Although inferior vena cava filters have evolved, specific complications like inferior vena cava thrombosis-induced deep vein thrombosis worsening and recurrent pulmonary embolism continue to pose challenges. This study analyzes the effects of geometric parameter variations of inferior vena cava filters, which have a significant impact on the thrombus formation inside the filter, the capture, dissolution, and hemodynamic flow of thrombus, as well as the shear stress on the filter and vascular wall. Methods: This study used computational fluid dynamic simulations with the carreau model to investigate the impact of varying inferior vena cava filter design parameters (number of struts, strut arm length, and tilt angle) on hemodynamics. Results: Recirculation and stagnation areas due to flow velocity and pressure, along with wall shear stress values, were identified as key factors. It is important to find a balance between wall shear stress high enough to aid thrombolysis and low enough to prevent platelet activation. The results of this paper show that the risk of platelet activation and thrombus filtration may be lowest when the wall shear stress of the filter ranges from 0 to 4 [Pa], minimizing stress concentration within the filter. Conclusion: 16 arm struts with a length of 20 mm and a tilt angle of 0° provide the best balance between thrombus capture and minimization of hemodynamic disturbance. This configuration minimizes the size of the stagnation and recirculation zones while maintaining sufficient wall shear stress for thrombus dissolution.

Advancing Thrombosis Research: A Novel Device for Measuring Clot Permeability.

Thromboembolism, a global leading cause of mortality, needs accurate risk assessment for effective prophylaxis and treatment. Current stratification methods fall short in predicting thrombotic events, emphasizing the need for a deeper understanding of clot properties. Fibrin clot permeability, a crucial parameter in hypercoagulable states, impacts clot structure and resistance to lysis. Current clot permeability measurement limitations propel the need for standardized methods. Prior findings underscore the importance of clot permeability in various thrombotic conditions but call for improvements and more precise, repeatable, and standardized methods. Addressing these challenges, our study presents an upgraded, portable, and cost-effective system for measuring blood clot permeability, which utilizes a pressure-based approach that adheres to Darcy's law. By enhancing precision and sensitivity in discerning clot characteristics, this innovation provides a valuable tool for assessing thrombotic risk and associated pathological conditions. In this paper, the authors present a device that is able to automatically perform the permeability measurements on plasma or fibrinogen in vitro-induced clots on specific holders (filters). The proposed device has been tailored to distinguish clot permeability, with high precision and sensitivity, between healthy subjects and high cardiovascular-risk patients. The precise measure of clot permeability represents an excellent indicator of thrombotic risk, thus allowing the clinician, also on the basis of other anamnestic and laboratory data, to attribute a risk score to the subject. The proposed instrument was characterized by performing permeability measurements in plasma and purified fibrinogen clots derived from 17 Behcet patients and 15 sex- and age-matched controls. As expected, our results clearly indicate a significant difference in plasma clot permeability in Behcet patients with respect to controls (0.0533 ± 0.0199 d vs. 0.0976 ± 0.0160 d, p < 0.001). This difference was confirmed in the patient's vs. control fibrin clots (0.0487 ± 0.0170 d vs. 0.1167 ± 0.0487 d, p < 0.001). In conclusion, our study demonstrates the feasibility, efficacy, portability, and cost-effectiveness of a novel device for measuring clot permeability, allowing healthcare providers to better stratify thrombotic risk and tailor interventions, thereby improving patient outcomes and reducing healthcare costs, which could significantly improve the management of thromboembolic diseases.

Ischemic Stroke Outcome Predicted by Serum Albumin Levels.

OBJECTIVE AND AIM:  This research aims to assess the predictive importance of serum albumin levels in individuals who have recently experienced an acute ischemic stroke and to establish a correlation between these two variables. MATERIALS AND METHODS: A prospective hospital-based investigation with 50 participants was conducted after receiving ethical approval from Sunshine Hospital, Hyderabad, India. Patients older than 18 years old who had radiological or clinical evidence of having suffered an acute ischemic stroke were considered for participation in the research. RESULTS:  Albumin levels in the blood are typically about 3.6 g/dL. One patient between the ages of 46 and 55 had low serum albumin levels. Many people in both groups had albumin levels of about 4.4. Serum albumin concentration was measured using the modified Rankin Scale (mRS). After one week and three months, 32 patients had mRS values of less than three, whereas 16 had mRS values of greater than three-one; the individual presented with an mRS value over 3, as well as a blood albumin level below 3.5. The p-value ended up being 0.428. No link could be supported by the statistical evidence identified. P = 0.249 indicated no association between serum albumin and National Institutes of Health Stroke Scale (NIHSS) scores. According to the findings of this inquiry, there is no correlation between the amounts of albumin in the blood and the NIHSS scores. CONCLUSION: This study did not find a correlation between higher blood albumin levels and a worse outcome after an ischemic stroke. It contradicts the corpus of current knowledge.

Aortic thrombosis and acute kidney injury due to atherosclerosis in a dog.

OBJECTIVE: Atherosclerosis is a chronic lipid-driven inflammatory disease of the arterial wall. Due to its cardiovascular ischemic complications, it is one of the most common causes of death in people. However, atherosclerosis is seldomly reported in dogs. ANIMAL: A 10-year-old male mixed-breed dog. CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES: Severe acute kidney injury associated with thrombosis of the abdominal aorta. TREATMENT AND OUTCOME: Treatment included renal replacement therapy, antithrombotic therapy, and supportive care. However, the dog developed neurological and respiratory complications and was euthanized due to worsening kidney function and lack of improvement of the thrombosis. Postmortem examination confirmed the presence of aortic thromboembolism and renal infarcts. Histology revealed severe chronic-active atherosclerosis of the distal aorta and renal arteries. CLINICAL RELEVANCE: Aortic thrombosis is uncommon in dogs, and it is often associated with underlying conditions such as protein-losing nephropathy, endocrine disorders, cardiac disease, or hypercoagulability. In this case, no specific underlying cause was identified and atherosclerosis was considered the primary cause of the thrombosis.

Contribution of Red Blood Cells and Platelets to Blood Clot Computed Tomography Imaging and Compressive Mechanical Characteristics.

Thrombus computed tomography (CT) imaging characteristics may correspond with thrombus mechanical properties and thus predict thrombectomy success. The impact of red blood cell (RBC) content on these properties (imaging and mechanics) has been widely studied. However, the additional effect of platelets has not been considered. The objective of the current study was to examine the individual and combined effects of blood clot RBC and platelet content on resultant CT imaging and mechanical characteristics. Human blood clot analogues were prepared from a combination of preselected RBC volumes and platelet concentrations to decouple their contributions. The resulting clot RBC content (%) and platelet content (%) were determined using Martius Scarlet Blue and CD42b staining, respectively. Non-contrast and contrast-enhanced CT (NCCT and CECT) scans were performed to measure the clot densities. CECT density increase was taken as a proxy for clinical perviousness. Unconfined compressive mechanics were analysed by performing 10 cycles of 80% strain. RBC content is the major determinant of clot NCCT density. However, additional consideration of the platelet content improves the association. CECT density increase is influenced by clot platelet and not RBC content. Platelet content is the dominant component driving clot stiffness, especially at high strains. Both RBC and platelet content contribute to the clot's viscoelastic and plastic compressive properties. The current in vitro results suggest that CT density is reflective of RBC content and subsequent clot viscoelasticity and plasticity, and that perviousness reflects the clot's platelet content and subsequent stiffness. However, these indications should be confirmed in a clinical stroke cohort.

Nerve Reconstruction Using ActiGraft Blood Clot in Rabbit Acute Peripheral Injury Model: Preliminary Study.

This preliminary study aimed to investigate an ActiGraft blood clot implant (RedDress Ltd., Pardes-Hanna, Israel) attempting to treat and induce the regeneration of a completely injured peripheral nerve with a massive loss defect. The tibial portion of the sciatic nerve in 11 rabbits was transected, and a 25 mm nerve gap was reconnected using a collagen tube. A comparison was performed between the treatment group (eight rabbits; reconnection using a tube filled with ActiGraft blood clot) and the control group (three rabbits; gap reconnection using an empty tube). The post-operative follow-up period lasted 18 weeks and included electrophysiological and histochemical assessments. The pathological severity score was high in the tube cross sections of the control group (1.33) compared to the ActiGraft blood clot treatment group (0.63). Morphometric analysis showed a higher percentage of the positive myelin basic protein (MBP) stained area in the ActiGraft blood clot group (19.57%) versus the control group (3.67%). These differences were not statistically significant due to the small group sizes and the large intra-group variability. The results of this preliminary study suggest that the application of an ActiGraft blood clot (into the collagen tube) can enable nerve recovery. However, a future study using a larger animal group is required to achieve objective statistical results.

Evaluation of DNA extracted from residual blood clots after serological testing.

DNA quality is of paramount importance for molecular biology research. This study aimed to assess the DNA extracted from residual blood clots after serological testing, focusing on the impact of blood clot segments, extraction kits, temporary storage durations (TSDs), and thawing methods on DNA quality. We divided the residual blood clot column (BCC) from healthy donors into three segments and utilized two different extraction kits. The BCCs were subjected to four TSDs at 4°C (7 days, 10 days, 1 month, and 2 months) and three thawing methods (4°C, room temperature, and 37°C). We found that the TIANamp Blood Clot DNA Kit yielded consistently high-quality DNA from each segment with stable A260/280 and A260/230 ratios. The DNA yield showed a strong positive correlation with leukocyte concentration, and a satisfactory median DNA yield of 28.79 µg/g BCC was obtained across all segments. DNA integrity, as measured by the DNA integrity number and DNA fragment peak size, decreased with increasing TSD at 4°C, with a notable decrease after 10 days of storage. Thawing at 37°C resulted in the lowest DNA fragment peak size. In conclusion, BCC could be an ideal DNA source with satisfactory yield and purity. A prolonged TSD at 4°C leads to an obvious decrease in DNA integrity, and thawing the frozen BCC at 37°C decreases DNA fragment sizes. To maintain DNA integrity, BCCs should be cryopreserved as soon as possible after short TSDs at 4°C and thawed at 4°C.

Contribution of staphylococcal virulence factors in the pathogenesis of thrombosis.

Staphylococci are responsible for many infections in humans, starting with skin and soft tissue infections and finishing with invasive diseases such as endocarditis, sepsis and pneumonia, which lead to high mortality. Patients with sepsis often demonstrate activated clotting pathways, decreased levels of anticoagulants, decreased fibrinolysis, activated endothelial surfaces and activated platelets. This results in disseminated intravascular coagulation and formation of a microthrombus, which can lead to a multiorgan failure. This review describes various staphylococcal virulence factors that contribute to vascular thrombosis, including deep vein thrombosis in infected patients. The article presents mechanisms of action of different factors released by bacteria in various host defense lines, which in turn can lead to formation of blood clots in the vessels.

Detection of Blood Clots Using a Whole Stent as an Active Implantable Biosensor.

Many cardiovascular problems stem from blockages that form within the vasculature and often treatment includes fitting a stent through percutaneous coronary intervention. This offers a minimally invasive therapy but re-occlusion through restenosis or thrombosis formation often occurs post-deployment. Research is ongoing into the creation of smart stents that can detect the occurrence of further problems. In this study, it is shown that selectively metalizing a non-conductive stent can create a set of electrodes that are capable of detecting a build-up of material around the stent. The associated increase in electrical impedance across the electrodes is measured, testing the stent with blood clot to mimic thrombosis. It is shown that the device is capable of sensing different amounts of occlusion. The stent can reproducibly sense the presence of clot showing a 16% +/-3% increase in impedance which is sufficient to reliably detect the clot when surrounded by explanted aorta (one sample t-test, p = 0.009, n = 9). It is demonstrated that this approach can be extended beyond the 3D printed prototypes by showing that it can be applied to a commercially available stent and it is believed that it can be further utilized by other types of medical implants.

Microfabricated Nitinol Stent Retrievers with a Micro-Patterned Surface.

Stent retrievers are medical devices that are designed to physically remove blood clots from within the blood vessels of the brain. This paper focuses on microfabricated nitinol (nickel-titanium alloy) stent retrievers, which feature micro-patterns on their surface to enhance the effectiveness of mechanical thrombectomy. A thick film of nitinol, which was 20 µm in thickness, was sputtered onto a substrate with a micro-patterned surface, using electroplated copper as the sacrificial layer. The nitinol film was released from the substrate and then thermally treated while folded into a cylindrical shape. In vitro experiments with pig blood clots demonstrated that the micro-patterns on the surface improved the efficacy of blood clot retrieval.

Numerical study of ultra-large von Willebrand factor multimers in coagulopathy.

An excessive von Willebrand factor (VWF) secretion, coupled with a moderate to severe deficiency of ADAMTS13 activity, serves as a linking mechanism between inflammation to thrombosis. The former facilitates platelet adhesion to the vessel wall and the latter is required to cleave VWF multimers. As a result, the ultra-large VWF (UL-VWF) multimers released by Weibel-Palade bodies remain uncleaved. In this study, using a computational model based on first principles, we quantitatively show how the uncleaved UL-VWF multimers interact with the blood cells to initiate microthrombosis. We observed that platelets first adhere to unfolded and stretched uncleaved UL-VWF multimers anchored to the microvessel wall. By the end of this initial adhesion phase, the UL-VWF multimers and platelets make a mesh-like trap in which the red blood cells increasingly accumulate to initiate a gradually growing microthrombosis. Although high-shear rate and blood flow velocity are required to activate platelets and unfold the UL-VWFs, during the initial adhesion phase, the blood velocity drastically drops after thrombosis, and as a result, the wall shear stress is elevated near UL-VWF roots, and the pressure drops up to 6 times of the healthy condition. As the time passes, these trends progressively continue until the microthrombosis fully develops and the effective size of the microthrombosis and these flow quantities remain almost constant. Our findings quantitatively demonstrate the potential role of UL-VWF in coagulopathy.

Case report: Total obstruction of the left main bronchus by a blood clot leads to pneumonectomy in a pregnant woman.

Introduction and importance: Airway obstruction resulting from blood clot formation is observed across various clinical scenarios and is often preceded by hemoptysis. This condition can significantly compromise respiratory function, potentially leading to life-threatening ventilatory distress. Case presentation: In this report, the authors present a case of acute airway obstruction associated with hemoptysis in an 18-week pregnant woman admitted to the emergency department for acute respiratory distress. Clinical and radiographic evidence strongly suggested the presence of an endobronchial blood clot causing focal airway obstruction. Diagnosis was confirmed through direct endoscopic evaluation. Clinical discussion: Initial attempts to remove the obstructing clot from the airway involved lavage, aspiration, and forceps extraction by using a bronchoscope. In cases in which these measures proved ineffective, other management strategies include rigid bronchoscopy, embolization, and surgical resection. Conclusion: Central airway obstruction is a critical condition caused by numerous factors such as tumours or blood clots. Treatment focuses on securing the airway, ensuring breathing, and using tools such as bronchoscopy for diagnosis and treatment. Surgery is considered a last resort when other methods are ineffective.

Effect of EDTA Activation on Blood Clot Structure in Regenerative Endodontics: A Scanning Electron Microscopy Study.

INTRODUCTION: EDTA plays a crucial role in regenerative endodontic therapy (RET) because of its significant biological effects. However, EDTA is also recognized as the preferred anticoagulant for hematologic tests. Thus, this study aimed to assess the influence of different EDTA activation techniques on the morphology of blood clots after conditioning the root canal dentin. METHODS: Forty extracted human teeth were prepared to simulate immature teeth and divided into the following 5 groups: (1) saline solution (negative control), (2) EDTA 17% + saline solution (CNI), (3) CNI + ultrasonic activation, (4) CNI + Easy clean activation, and (5) CNI + XP-endo Finisher activation. After irrigation, the roots were cleaved, and the root canals were filled with human blood to clot formation. The morphology and density of erythrocytes, platelets, and the fibrin network were observed using a scanning electron microscope. The fibrin network density was classified using a 4-point scale. Data were analyzed using the Friedman test and the Kruskal-Wallis test with Bonferroni adjustment (α = 5%). RESULTS: All groups exhibited consistent blood clot morphology characterized by a high density of erythrocytes, platelets, and white blood cells throughout the entire length of the root canal. The negative control group showed statistically significant high scores of fibrin density compared with the CNI group in all root thirds (P < .05). However, there was no statistical difference in the scores for the fibrin network density between the groups irrigated with EDTA with and without activation (P > .05). CONCLUSIONS: EDTA may impair the fibrin network formation compared with the saline group. However, EDTA activation did not significantly change the effects on the blood clot in contact with the conditioned intraradicular dentin.

Fast screening using attenuated total reflectance- fourier transform infrared (ATR-FTIR) spectroscopy of patients based on D-dimer threshold value.

Attenuated Total Reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy is an emerging technology in the medical field. Blood D-dimer was initially studied as a marker of the activation of coagulation and fibrinolysis. It is mainly used as a potential diagnosis screening test for pulmonary embolism or deep vein thrombosis but was recently associated with COVID-19 severity. This study aimed to evaluate the use of ATR-FTIR spectroscopy with machine learning to classify plasma D-dimer concentrations. The plasma ATR-FTIR spectra from 100 patients were studied through principal component analysis (PCA) and two supervised approaches: genetic algorithm with linear discriminant analysis (GA-LDA) and partial least squares with linear discriminant (PLS-DA). The spectra were truncated to the fingerprint region (1800-1000 cm-1). The GA-LDA method effectively classified patients according to D-dimer cutoff (≤0.5 µg/mL and >0.5 µg/mL) with 87.5 % specificity and 100 % sensitivity on the training set, and 85.7 % specificity, and 95.6 % sensitivity on the test set. Thus, we demonstrate that ATR-FTIR spectroscopy might be an important additional tool for classifying patients according to D-dimer values. ATR-FTIR spectral analyses associated with clinical evidence can contribute to a faster and more accurate medical diagnosis, reduce patient morbidity, and save resources and demand for professionals.

The Effect of Blood Clots on the Quality of RNA Extracted from PAXgene Blood RNA Tubes.

Background: PAXgene® Blood RNA tubes are routinely used in clinical research and molecular biology applications to preserve the stability of RNA in whole blood. However, in practice, blood clots are occasionally observed after blood collection and are often ignored. Currently, there are few studies on whether blood clots affect the quality of RNA extracted from these tubes. Materials and Methods: Fifteen pairs of non-clot and clot PAXgene Blood RNA tube samples (n = 30) were collected to form two matched groups from 15 patients. According to the maximum diameter (d) of the blood clot observed visually at the time of sample reception, the clot groups were divided into a small-clot group (0 cm < d < 0.5 cm) and a large-clot group (d ≥ 0.5 cm). RNA was extracted by the PAXgene Blood RNA Kit. To analyze the quality of RNA, its yield and purity were assessed by spectrophotometry, and integrity was measured by microfluidic electrophoresis. An A260/280 ratio between 1.8 and 2.2 indicated purified RNA, and RNA integrity number (RIN) values ≥7.0 were considered to represent qualified integrity. Results: The median yields of RNA from the non-clot and clot groups were 3.84 (2.80-6.38) µg and 4.87 (2.77-8.30) µg, respectively. The median A260/280 ratios were 2.08 (2.06-2.09) and 2.09 (2.07-2.11), whereas the median A260/230 ratios were 1.77 (1.31-1.91) and 1.67 (1.21-1.94) in the two groups. In addition, the median RINs were 8.20 (8.00-8.40) and 7.20 (6.60-7.70), respectively. There were no significant differences in RNA yields, A260/280, or A260/230 between the two groups. However, the RIN value of the clot group was significantly lower compared with the non-clot group (p < 0.05), with RIN ≥7.0 found in all non-clot samples and 60% of clot samples (p < 0.05). Furthermore, in the clot groups, the small-clot samples had higher RIN values than large-clot samples (8.25 [7.75-8.75] vs. 6.90 [6.60-7.30], p < 0.001). Conclusions: The formation of large blood clots in PAXgene Blood RNA tubes will reduce the integrity of extracted RNA.