Chemokine platelet factor 4 accelerates peripheral nerve regeneration by regulating Schwann cell activation and axon elongation

Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and found that expression of platelet factor 4 was markedly up-regulated after sciatic nerve injury.Platelet factor is an important molecule in cell apoptosis,diffe rentiation,survival,and proliferation.Further,polymerase chain reaction and immunohistochemical staining confirmed the change in platelet factor 4 in the sciatic nerve at different time points after injury.Enzyme-linked immunosorbent assay confirmed that platelet factor 4 was secreted by Schwann cells.We also found that silencing platelet factor 4 decreased the proliferation and migration of primary cultured Schwann cells,while exogenously applied platelet factor 4 stimulated Schwann cell prolife ration and migration and neuronal axon growth.Furthermore,knocking out platelet factor 4 inhibited the prolife ration of Schwann cells in injured rat sciatic nerve.These findings suggest that Schwann cell-secreted platelet factor 4 may facilitate peripheral nerve repair and regeneration by regulating Schwann cell activation and axon growth.Thus,platelet factor 4 may be a potential therapeutic target for traumatic peripheral nerve injury.

Clinical significance of platelet mononuclear cell aggregates in patients with sepsis and acute respiratory distress syndrome

BACKGROUND The diagnosis of sepsis combined with acute respiratory distress syndrome(ARDS)has increased owing to the enhanced awareness among medical profes-sionals and the continuous development of modern medical technologies,while early diagnosis of ARDS still lacks specific biomarkers.One of the main patho-genic mechanisms of sepsis-associated ARDS involves the actions of various pathological injuries and inflammatory factors,such as platelet and white blood cells activation,leading to an increase of surface adhesion molecules.These adhesion molecules further form platelet-white blood cell aggregates,including platelet-mononuclear cell aggregates(PMAs).PMAs has been identified as one of the markers of platelet activation,here we hypothesize that PMAs might play a potential biomarker for the early diagnosis of this complication.METHODS We selected 72 hospitalized patients diagnosed with sepsis as the study population between March 2019 and March 2022.Among them,30 patients with sepsis and ARDS formed the study group,while 42 sepsis patients without ARDS comprised the control group.After diagnosis,venous blood samples were imme-diately collected from all patients.Flow cytometry was employed to analyze the expression of PMAs,platelet neutrophil aggregates(PNAs),and platelet aggregates(PLyAs)in the serum.Additionally,the Acute Physiology and Chronic Health Evaluation(APACHE)II score was calculated for each patient,and receiver operating characteristic curves were generated to assess diagnostic value.RESULTS The study found that the levels of PNAs and PLyAs in the serum of the study group were higher than those in the control group,but the difference was not statistically significant(P>0.05).However,the expression of PMAs in the serum of the study group was significantly upregulated(P<0.05)and positively correlated with the APACHE II score(r=0.671,P<0.05).When using PMAs as a diagnostic indicator,the area under the curve value was 0.957,indicating a high diagnostic value(P<0.05).Furthermore,the optimal cutoff value was 8.418%,with a diagnostic sensitivity of 0.819 and specificity of 0.947.CONCLUSION In summary,the serum levels of PMAs significantly increase in patients with sepsis and ARDS.Therefore,serum PMAs have the potential to become a new biomarker for clinically diagnosing sepsis complicated by ARDS.

Case of Refractory Thrombocytopenia in Pregnancy Associated with May-Heglin Anomaly after Repeated Platelet Transfusions

May-Heglin Anomaly is an autosomal dominant disorder characterized by macrothrombocytopenia with a platelet function that is usually preserved. Platelets play an essential role in hemostasis. During pregnancy, a woman is susceptible to complications, including postpartum hemorrhage. Monitoring patients’ hemostatic functions and observing the patient’s clinical picture to maintain patient safety is paramount, while avoiding unnecessary therapeutic measures. This case report presents a rare instance of May-Heglin Anomaly (MHA) in a 35-year-old pregnant patient, with refractory thrombocytopenia despite receiving multiple platelet transfusions. Initially referred to as gravida 5 para 4 with severe thrombocytopenia at 28 weeks gestation, throughout her pregnancy, she was closely monitored and received over 40 units of platelets, which failed to increase her platelet count significantly. She delivered a healthy baby via vaginal delivery at 38 weeks, with her platelet count still critically low. This report highlights the challenges of managing MHA in pregnancy, the inefficacy of standard thrombocytopenia treatments such as platelet transfusion in MHA patients, and the importance of tailored management strategies to ensure maternal and fetal safety.

Kelp Fucoidans Facilitate Vascular Recanalization via Inhibiting Excessive Activation of Platelet in Deep Venous Thrombosis Model of Mouse

This study was carried out explore the mechanism underlying the inhibition of platelet activation by kelp fucoidans in deep venous thrombosis(DVT)mouse.In the control and sham mice,the walls of deep vein were regular and smooth with intact intima,myometrium and adventitia.The blood vessel was wrapped with the tissue and there was no thrombosis in the lumen.In the DVT model,the wall was uneven with thicken intima,myometrium and adventitia.After treated with fucoidans LF1 and LF2,the thrombus was dissolved and the blood vessel was recanalized.Compared with the control group,the ROS content,ET-1 and VWF content and the expression of PKC-βand NF-κB in the model were significantly higher(P<0.05);these levels were significantly reduced following treatments with LF2 and LF1.Compared with H_(2)O_(2)treated-HUVECs,combined LF1 and LF2 treatment resulted in significant decrease in the expression of PKC-β,NF-κB,VWF and TM protein(P<0.05).It is clear that LF1 and LF2 reduces DVT-induced ET-1,VWF and TM expressions and production of ROS,thus inhibiting the activation of PKC-β/NF-κB signal pathway and the activation of coagulation system and ultimately reducing the formation of venous thrombus.

Aspirin suppresses hepatocellular carcinoma progression by inhibiting platelet activity

BACKGROUND Hepatocellular carcinoma(HCC)is the most common malignant liver disease in the world.Platelets(PLTs)are known to play a key role in the maintenance of liver homeostasis and the pathophysiological processes of a variety of liver diseases.Aspirin is the most classic antiplatelet agent.However,the molecular mechanism of platelet action and whether aspirin can affect HCC progression by inhibiting platelet activity need further study.AIM To explore the impact of the antiplatelet effect of aspirin on the development of HCC.METHODS Platelet-rich plasma,platelet plasma,pure platelet,and platelet lysate were prepared,and a coculture model of PLTs and HCC cells was established.CCK-8 analysis,apoptosis analysis,Transwell analysis,and real-time polymerase chain reaction(RT-PCR)were used to analyze the effects of PLTs on the growth,metastasis,and inflammatory microenvironment of HCC.RT-PCR and Western blot were used to detect the effects of platelet activation on tumor-related signaling pathways.Aspirin was used to block the activation and aggregation of PLTs both in vitro and in vivo,and the effect of PLTs on the progression of HCC RESULTS PLTs significantly promoted the growth,invasion,epithelial-mesenchymal transition,and formation of an inflammatory microenvironment in HCC cells.Activated PLTs promoted HCC progression by activating the mitogenactivated protein kinase/protein kinase B/signal transducer and activator of transcription three(MAPK/AKT/STAT3)signaling axis.Additionally,aspirin inhibited HCC progression in vitro and in vivo by inhibiting platelet activation.CONCLUSION PLTs play an important role in the pathogenesis of HCC,and aspirin can affect HCC progression by inhibiting platelet activity.These results suggest that antiplatelet therapy has promising application prospects in the treatment and combined treatment of HCC.

Inverse relationship between platelet Akt activity and hippocampal atrophy:A pilot case-control study in patients with diabetes mellitus

BACKGROUND Akt plays diverse roles in humans.It is involved in the pathogenesis of type 2 diabetes mellitus(T2DM),which is caused by insulin resistance.Akt also plays a vital role in human platelet activation.Furthermore,the hippocampus is closely associated with memory and learning,and a decrease in hippocampal volume is reportedly associated with an insulin-resistant phenotype in T2DM patients without dementia.AIM To investigate the relationship between Akt phosphorylation in unstimulated platelets and the hippocampal volume in T2DM patients.METHODS Platelet-rich plasma(PRP)was prepared from the venous blood of patients with T2DM or age-matched controls.The pellet lysate of the centrifuged PRP was subjected to western blotting to analyse the phosphorylation of Akt,p38 mitogen-activated protein(MAP)kinase and glyceraldehyde 3-phosphate dehydrogenase(GAPDH).Phosphorylation levels were quantified by densitometric analysis.Hippocampal volume was analysed using a voxel-based specific regional analysis system for Alzheimer’s disease on magnetic resonance imaging,which proposes the Z-score as a parameter that reflects hippocampal volume.RESULTS The levels of phosphorylated Akt corrected with phosphorylated p38 MAP kinase were inversely correlated with the Z-scores in the T2DM subjects,whereas the levels of phosphorylated Akt corrected with GAPDH were not.However,this relationship was not observed in the control patients.CONCLUSION These results suggest that an inverse relationship may exist between platelet Akt activation and hippocampal atrophy in T2DM patients.Our findings provide insight into the molecular mechanisms underlying T2DM hippocampal atrophy.

Platelet indices as predictors of poor glucoregulation in type 2 diabetes mellitus adults at Bishoftu General Hospital,Ethiopia

BACKGROUND Diabetes is a chronic metabolic syndrome that has become a global public health problem with significant morbidity and mortality.It is a pro-inflammatory and pro-thrombotic condition characterized by increased platelet activation and alterations in platelet indices.However,the use of platelet indices as predictors of poor glucoregulation has not been fully evaluated in this context,and evidence for their role as predictors of poor glycemic status in diabetic patients is limited.AIM To evaluate platelet indices and determine their prognostic significance in relation to inadequate glucoregulation among individuals diagnosed with type 2 diabetes at Bishoftu General Hospital in Ethiopia,from June 15 to August 12,2022.METHODS A comparative cross-sectional study was conducted in 261 participants including 174 individuals with type 2 diabetes mellitus(T2DM)and 87 non-diabetic controls.The systematic random sampling technique was used to select participants.Data were collected using structured questionnaires,physical measurements,checklists,and laboratory tests.Platelet parameters and fasting blood glucose levels were determined from blood samples using Sysmex-XN550 and CobasC311 analyzers,respectively.The hematology analyzer output was checked and participants were also screened for malaria parasites using a prepared blood smear.Collected data were entered into Epi-data version 3.1 and exported to SPSS version 25 for analysis.Theχ^(2) test,Mann-Whitney U test,Kruskal-Wallis test,post hoc test,Spearman correlation,and receiver operating characteristic curve were used for analysis.A P value<0.05 was considered statistically significant.RESULTS The results of our study indicate that diabetic patients have significantly higher levels of platelet distribution width(PDW),mean platelet volume(MPV),platelet large cell ratio(PLCR),and plateletcrit(PCT)compared to healthy individuals(P<0.001).Furthermore,these indices were found to be significantly elevated in individuals with poor glycemic control in T2DM compared to those with good glycemic control and healthy controls.We also observed significant correlations between these indices and various anthropometric and clinical variables.Our findings suggest that PDW,with a cut-off value of 15.75 fL and an area under the curve(AUC)of 0.803,MPV,with a cut-off value of 12.25 fL and an AUC of 0.774,PLCR,with a cut-off value of 36.3%and an AUC of 0.775,and PCT,with a cut-off value of 0.24%and an AUC of 0.761,can serve as predictors of poor glycemic control in patients with diabetes mellitus.CONCLUSION The observed correlation between diabetic patients and a significant increase in platelet indices has highlighted their potential as predictors of poor glycemic control in diabetes.Therefore,regular screening and profiling of platelet indices is recommended as part of the follow-up process for individuals with diabetes mellitus.

Intra-articular interventions in osteoarthritis:Navigating the landscape of hyaluronic acid,mesenchymal stem cells,and plateletrich plasma

Osteoarthritis(OA)poses a substantial burden on patients,leading to pain,functional decline,and reduced quality of life.While conventional treatments focus on symptom management,disease-modifying interventions are yet to be established.This review explores the efficacy of intra-articular interventions,particularly hyaluronic acid(HA),mesenchymal stem cells(MSCs),and platelet-rich plasma(PRP),in the context of OA management.HA injections,with diverse formulations like Hylan G-F20,sodium hyaluronate,and hyaluronan,present varying outcomes,necessitating a nuanced understanding of their effectiveness and timing.MSC therapy,derived from adipose tissue,umbilical cord,or bone marrow,shows promising results in clinical improvement,with adipose-derived MSCs demonstrating efficacy in maintaining benefits over 6 mo.Conversely,bone-marrow-derived MSCs show limited effectiveness,highlighting the need for sourcespecific considerations.PRP has emerged as a superior option for long-term pain reduction and quality of life improvement,with leukocyte-poor formulations and a critical platelet count of 10 billion demonstrating optimal results.This comprehensive analysis underscores the potential of intra-articular interventions in OA management,emphasizing the need for personalized and evidence-based approaches to enhance treatment efficacy and patient outcomes.

Platelet counts to spleen diameter ratio:A promising noninvasive tool for predicting esophageal varices in cirrhosis patients

BACKGROUND Liver cirrhosis is the end stage of progressive liver fibrosis as a consequence of chronic liver inflammation,wherein the standard hepatic architecture is replaced by regenerative hepatic nodules,which eventually lead to liver failure.Cirrhosis without any symptoms is referred to as compensated cirrhosis.Complications such as ascites,variceal bleeding,and hepatic encephalopathy indicate the onset of decompensated cirrhosis.Gastroesophageal varices are the hallmark of clini-cally significant portal hypertension.AIM To determine the accuracy of the platelet count-to-spleen diameter(PC/SD)ratio to evaluate esophageal varices(EV)in patients with cirrhosis.METHODS This retrospective observational study was conducted at Tikur Anbessa Specia-lized Hospital and Adera Medical Center from January 1,2019,to December 30,2023.Data were collected via chart review and direct patient interviews using structured questionnaires.The data were exported to the SPSS software version 26 for analysis and clearance.A receiver operating characteristic curve was plotted for splenic diameter,platelet count,and PC/SD ratio to obtain sensitivity,speci-ficity,positive predictive value,negative predictive value,positive likelihood ratio,and negative likelihood ratio.RESULTS Of the 140 participants,67%were men.Hepatitis B(38%)was the most common cause of cirrhosis,followed by cryptogenic cirrhosis(28%)and hepatitis C(16%).Approximately 83.6%of the participants had endoscopic evidence of EV,whereas 51.1%had gastric varices.Decompensated cirrhosis and PC were associated with the presence of EV with adjusted odds ratios of 12.63(95%CI:3.16-67.58,P=0.001)and 0.14(95%CI:0.037-0.52,P=0.004),respectively.A PC/SD ratio<1119 had a sensitivity of 86.32%and specificity of 70%with area under the curve of 0.835(95%CI:0.736-0.934,P<0.001).CONCLUSION A PC/SD ratio<1119 predicts EV in patients with cirrhosis.It is a valuable,noninvasive tool for EV risk assess-ment in resource-limited settings.

Red cell distribution width/platelet ratio estimates the 3-year risk of decompensation in Metabolic Dysfunction-Associated Steatotic Liver Disease-induced cirrhosis

BACKGROUND For compensated advanced chronic liver disease(cACLD)patients,the first decompensation represents a dramatically worsening prognostic event.Based on the first decompensation event(DE),the transition to decompensated advanced chronic liver disease(dACLD)can occur through two modalities referred to as acute decompensation(AD)and non-AD(NAD),respectively.Clinically Significant Portal Hypertension(CSPH)is considered the strongest predictor of decompensation in these patients.However,due to its invasiveness and costs,CSPH is almost never evaluated in clinical practice.Therefore,recognizing noninvasively predicting tools still have more appeal across healthcare systems.The red cell distribution width to platelet ratio(RPR)has been reported to be an indicator of hepatic fibrosis in Metabolic Dysfunction-Associated Steatotic Liver Disease(MASLD).However,its predictive role for the decompensation has never been explored.AIM In this observational study,we investigated the clinical usage of RPR in predicting DEs in MASLD-related cACLD patients.METHODS Fourty controls and 150 MASLD-cACLD patients were consecutively enrolled and followed up(FUP)semiannually for 3 years.At baseline,biochemical,clinical,and Liver Stiffness Measurement(LSM),Child-Pugh(CP),Model for End-Stage Liver Disease(MELD),aspartate aminotransferase/platelet count ratio index(APRI),Fibrosis-4(FIB-4),Albumin-Bilirubin(ALBI),ALBI-FIB-4,and RPR were collected.During FUP,DEs(timing and modaities)were recorded.CSPH was assessed at the baseline and on DE occurrence according to the available Clinical Practice Guidelines.RESULTS Of 150 MASLD-related cACLD patients,43(28.6%)progressed to dACLD at a median time of 28.9 months(29 NAD and 14 AD).Baseline RPR values were significantly higher in cACLD in comparison to controls,as well as MELD,CP,APRI,FIB-4,ALBI,ALBI-FIB-4,and LSM in dACLD-progressing compared to cACLD individuals[all P<0.0001,except for FIB-4(P:0.007)and ALBI(P:0.011)].Receiving operator curve analysis revealed RPR>0.472 and>0.894 as the best cut-offs in the prediction respectively of 3-year first DE,as well as its superiority compared to the other non-invasive tools examined.RPR(P:0.02)and the presence of baseline-CSPH(P:0.04)were significantly and independently associated with the DE.Patients presenting baseline-CSPH and RPR>0.472 showed higher risk of decompensation(P:0.0023).CONCLUSION Altogether these findings suggest the RPR as a valid and potentially applicable non-invasive tool in the prediction of timing and modalities of decompensation in MASLD-related cACLD patients.

Salivary C-reactive protein and mean platelet volume as possible diagnostic markers for late-onset neonatal pneumonia

BACKGROUND Neonatal sepsis,a formidable threat to newborns,is a leading cause of neonatal mortality,with late-onset sepsis manifesting after 72 hours post-birth being particularly concerning.Pneumonia,a prevalent sepsis presentation,poses a significant risk,especially during the neonatal phase when lung defenses are compromised.Accurate diagnosis of pneumonia is imperative for timely and effective interventions.Saliva,a minimally invasive diagnostic medium,holds great promise for evaluating infections,especially in infants.AIM To investigate the potential of serum C-reactive protein(CRP),salivary CRP(sCRP),and mean platelet volume(MPV)as diagnostic markers for late-onset neonatal pneumonia(LONP).METHODS Eighty full-term neonates were systematically examined,considering anthropometric measurements,clinical manifestations,radiology findings,and essential biomarkers,including serum CRP,sCRP,and MPV.RESULTS The study reveals noteworthy distinctions in serum CRP levels,MPV,and the serum CRP/MPV ratio between neonates with LONP and healthy controls.MPV exhibited a robust discriminatory ability[area under the curve(AUC)=0.87]with high sensitivity and specificity at a cutoff value of>8.8.Correlations between serum CRP,sCRP,and MPV were also identified.Notably,sCRP demonstrated excellent predictive value for serum CRP levels(AUC=0.89),underscoring its potential as a diagnostic tool.CONCLUSION This study underscores the diagnostic promise of salivary and serum biomarkers,specifically MPV and CRP,in identifying and predicting LONP among neonates.These findings advocate for further research to validate their clinical utility in larger neonatal cohorts.

Combining Serum Procalcitonin Level,Thromboelastography,and Platelet Count to Predict Short-term Development of Septic Shock in Intensive Care Unit

Objective Despite the recent advances in diagnosis and treatment,sepsis continues to lead to high morbidity and mortality.Early diagnosis and prompt treatment are essential to save lives.However,most biomarkers can only help to diagnose sepsis,but cannot predict the development of septic shock in high-risk patients.The present study determined whether the combined measurement of procalcitonin(PCT),thromboelastography(TEG)and platelet(PLT)count can predict the development of septic shock.Methods A retrospective study was conducted on 175 septic patients who were admitted to the intensive care unit between January 2017 and February 2021.These patients were divided into two groups:73 patients who developed septic shock were assigned to the septic shock group,while the remaining 102 patients were assigned to the sepsis group.Then,the demographic,clinical and laboratory data were recorded,and the predictive values of PCT,TEG and PLT count for the development of septic shock were analyzed.Results Compared to the sepsis group,the septic shock group had statistically lower PLT count and TEG measurements in the R value,K value,αangle,maximum amplitude,and coagulation index,but had longer prothrombin time(DT),longer activated partial thromboplastin time(APTT),and higher PCT levels.Furthermore,the Sequential Organ Failure Assessment(SOFA)score was higher in the septic shock group.The multivariate logistic regression analysis revealed that PCT,TEG and PLT count were associated with the development of septic shock.The area under the curve analysis revealed that the combined measurement of PCT,TEG and PLT count can be used to predict the development of septic shock with higher accuracy,when compared to individual measurements.Conclusion The combined measurement of PCT,TEG and PLT count is a novel approach to predict the development of septic shock in high-risk patients.

Blood coagulation factors and platelet response to drug-induced hepatitis and hepatosis in rats

Background:Knowing the variability of blood coagulation responses to liver damage of different origins can provide a key to curing liver tissues or to mitigating treatment side effects.The aim of the present work was to compare the changes in the main components of hemostasis under experimental drug-induced hepatosis and hepatitis in rats.Methods:We modeled diclofenac-induced hepatitis and tetracycline-induced hepa-tosis.Hemostasis response was gauged by measuring fibrinogen,factor X,protein C(PC),and prothrombin in plasma.The decarboxylated form of prothrombin was de-tected by measuring prothrombin index and ecamulin index.Platelet reactivity was studied using aggregometry.Results:Both hepatitis and hepatosis decreased the synthesis of fibrinogen,factor X,and prothrombin.However,protein carboxylation was not disrupted in hepatosis but was much impaired in hepatitis.PC decreased in both models as a consequence of its consumption possibly during inflammatory response.Platelet aggregation rate was lower in hepatosis but higher in hepatitis.Conclusions:Our findings imply the need for a thorough monitoring of the hemostasis system in liver diseases to avoid possible thrombotic complications.Its state indicates the disorder's rate and character.

Platelet rich fibrin is not a barrier membrane!Or is it?

Platelet-rich fibrin(PRF)is widely used in dentistry and other fields of medicine,and its use has become popular in dental implantology.In several published studies,PRF has been used as a barrier membrane.A barrier membrane is a sheet of a certain material that acts as a biological and mechanical barrier against the invasion of cells that are not involved in bone formation,such as epithelial cells.Among the basic requirements of a'barrier membrane,occlusivity,stiffness,and space maintenance are the criteria that PRF primarily lacks;therefore,it does not fall under the category of barrier membranes.However,there is evidence that PRF membranes are useful in significantly improving wound healing.Does the PRF membrane act as a barrier?Should we think of adding or subtracting some points from the ideal requirements of a barrier membrane,or should we coin a new term or concept for PRF that will incorporate some features of a barrier membrane and be a combination of tissue engineering and biotechnology?This review is aimed at answering the basic question of whether the PRF membrane should be considered a barrier membrane or whether it is something more beyond the boundaries of a barrier membrane.

Hemoglobin, albumin, lymphocyte, and platelet score as a predictor of prognosis in metastatic gastric cancer

BACKGROUND The hemoglobin,albumin,lymphocyte,and platelet(HALP)score,derived from a composite evaluation of markers reflecting the tumor-inflammation relationship and nutritional status,has been substantiated as a noteworthy prognostic determinant for diverse malignancies.AIM To investigate how the HALP score relates to prognosis in patients with metastatic gastric cancer.METHODS The cutoff values for the HALP score,neutrophil/lymphocyte ratio,and platelet/lymphocyte ratio were determined using receiver operating characteristic analysis.Low HALP scores were defined as those less than 24.79 and high HALP scores as those greater than 24.79.RESULTS The study cohort comprised 147 patients and 110 of them(74.8%)were male.The patients'median age was 63(22-89)years.The median overall survival was significantly superior in the patients with high HALP scores than in those with low HALP scores(10.4 mo vs 7.5 mo,respectively;P<0.001)CONCLUSION The HALP score was found to be a prognostic factor in patients with metastatic gastric cancer.

Platelet factor 4 induces bone loss by inhibiting the integrinα5-FAK-ERK pathway

Background:The effect of platelet factor 4(PF4)on bone marrow mesenchymal stem cells(BMMSCs)and osteoporosis is poorly understood.Therefore,this study aimed to evaluate the effects of PF4-triggered bone destruction in mice and determine the underlying mechanism.Methods:First,in vitro cell proliferation and cell cycle of BMMSCs were assessed using a CCK8 assay and flow cytometry,respectively.Osteogenic differentiation was confirmed using staining and quantification of alkaline phosphatase and Alizarin Red S.Next,an osteoporotic mouse model was established by performing bilateral ovariectomy(OVX).Furthermore,the PF4 concentrations were obtained using enzymelinked immunosorbent assay.The bone microarchitecture of the femur was evaluated using microCT and histological analyses.Finally,the key regulators of osteogenesis and pathways were investigated using quantitative real-time polymerase chain reaction and Western blotting.Results:Human PF4 widely and moderately decreased the cell proliferation and osteogenic differentiation ability of BMMSCs.Furthermore,the levels of PF4 in the serum and bone marrow were generally increased,whereas bone microarchitecture deteriorated due to OVX.Moreover,in vivo mouse PF4 supplementation triggered bone deterioration of the femur.In addition,several key regulators of osteogenesis were downregulated,and the integrinα5-focal adhesion kinase-extracellular signalregulated kinase(ITGA5-FAK-ERK)pathway was inhibited due to PF4 supplementation.Conclusions:PF4 may be attributed to OVX-i nduced bone loss triggered by the suppression of bone formation in vivo and alleviate BMMSC osteogenic differentiation by inhibiting the ITGA5-FAK-ERK pathway.

First platelet transfusion refractoriness in a patient with acute myelocytic leukemia: A case report

BACKGROUND Platelet transfusion is of great significance in the treatment of thrombocytopenia caused by myelosuppression during intensive chemotherapy in patients with acute leukemia.In recent years,with platelet transfusion increasing,ineffective platelet transfusion has become increasingly prominent.Generally speaking,platelet antibodies can be produced after repeated transfusion,thus rendering subsequent platelet transfusion ineffective.We report a case of first platelet transfusion refractoriness(PTR)in a patient with acute myelocytic leukemia(AML).Due to the rarity of such cases in clinical practice,there have been no relevant case reports so far.CASE SUMMARY A 51-year-old female patient attended the hospital due to throat pain and abnormal blood cells for 4 d.Her diagnosis was acute myelocytic leukemia[M2 type Fms related receptor tyrosine kinase 3,Isocitrate Dehydrogenase 1,Nucleophosmin 1,Neuroblastoma RAS viral oncogene homolog(+)high-risk group].She was treated with"IA"(IDA 10 mg day 1-3 and Ara-C 0.2 g day 1-5)chemotherapy.When her condition improved,the patient was discharged from the hospital,instructed to take medicine as prescribed by the doctor after discharge,and returned to the hospital for further chemotherapy on time.CONCLUSION We report a rare case of first platelet transfusion failure in a patient with AML during induction chemotherapy,which may be related to the production of platelet antibodies induced by antibiotics and excessive tumor load.This also suggests that we should consider the influence of antibiotics when the rare situation of first platelet transfusion failure occurs in patients with AML.When platelet antibodies are produced,immunoglobulins can be used to block antibodies,thereby reducing platelet destruction.For patients with PTR,both immune and non-immune factors need to be considered and combined in clinical practice along with individualized treatment to effectively solve the problem.

Clinical Evaluation of Platelet Rich Growth Factors (PRGFS) in Treatment of Temporomandibular Joint Disc Displacement—Study Report

Objective: The aim of the study was to evaluate the effect of platelet rich growth factors (PRGFs) in treatment of temporomandibular joint disc displacement. Materials and Methods: The study subjects included 8 females having bilateral anterior disc displacement with reduction and 1 female having bilateral anterior disc displacement without reduction with the age range between 20 - 35 years. The process of obtaining PRGFs was carried out following the Anitua Technique. Results: Clinical parameters of Interincisal distance, Lateral excursion of mandible using digital caliper in millimeters and Visual Analogue Scale (VAS 0/10) for pain intensity score were used. All of these parameters were running through the intervals of two, four, and eight weeks till the end of the follow-up period at twenty-six weeks (six months). The participated patients showed the clinical improvement in the different clinical statuses such as interincisal distance;lateral excursion of mandible and Pain Score. Conclusion: the study reported early efficacy of PRGFs after the arthrocentesis of the joint in treatment of TMJ disc displacement, and according to our results, the injection of PRGFs could be a possible alternative treatment for patients who did not respond to standard treatment.

Platelets Play an Integral Role in Body Heat Production and Maintenance: A Newly Proposed Function

In platelets, most of the ADP is stored in dense granules and released into extracellular space through exocytosis as a signaling molecule upon platelet activation. Glycolysis and the TCA cycle consume considerable amounts of ADP;however, limiting quantities of available ADP to make ATP through OXPHOS result in failure of ATP production and release of energy as heat into the surroundings. Thus, body heat may be a potential product of circulating platelets. Furthermore, the incomplete OXPHOS process causes the production of ROS that leads to earlier platelet death resulting in shorter life span. In the future, this new function may have a wide variety of clinical applications.

Effects of platelets on characteristics of lymphocytes cultured in vitro and optimization of adoptive immunotherapy

T lymphocytes,the main participants of cellular immunity,can express a variety of surface molecules and form different lymphocyte subsets under the induction of different factors to play the functions of immune regulation and immune killing.Studies have shown that platelets play a crucial role in maintaining the stable differentiation of lymphocytes and the balance in immunomodulation.Therefore,it is necessary to study the effect of platelets on lymphocytes in vitro to better understand the role of platelets in the immune system and broaden the application of adoptive immunotherapy.Methods:Cell counting and microscopic observation were used to detect the effect of activated platelets on lymphocyte proliferation in vitro;Flow cytometry was used to detect whether changes in platelet activity affect the proportion of lymphocyte subpopulations in vitro,and to detect differences in the expression of granzyme B;lactate dehydrogenase assay(LDH)was used to determine the difference in lymphocyte killing activity caused by platelet activity in vitro.Results:This was the first to promote lymphocyte proliferation through the expression or release of certain molecules in vitro,demonstrating that platelet activation is one of the key factors.Secondly,activated platelets or inactivated platelets promoted lymphocyte subset differentiation by enhancing the proportion of CD3+CD8+T lymphocytes(CTL cells)but had a slight effect on the proportion of CD3+CD4+T(Th cells)and CD4+CD25+T lymphocytes(Treg cells).Then,it was found that either activated platelets or inactivated platelets down-regulated the proportion of natural killer(NK)T lymphocytes,while activated platelets significantly enhance the proportion of NK lymphocytes.Therefore,by further detecting the killing activity of PBMCs treated with platelets,it was found that activated platelets promoted the extensive anti-tumor activity of lymphocytes and significantly increased the expression of granzyme B.Conclusion:Our results suggest that activated platelets promote lymphocyte proliferation,optimize lymphocyte subpopulation ratio,and promote cytotoxic effect of lymphocytes in vitro,which may provide a new strategy for optimizing the adoptive immunotherapy culture system and improving its efficacy.