Efficacy of low-dose rituximab in a refractory acquired factor VIII inhibitor case secondary to pemphigus.

Acquired factor VIII (FVIII) inhibitor induces a bleeding disorder caused by specific antibodies to FVIII. The cause of approximately one fifth of cases can be attributed to autoimmune disorders, such as pemphigus. Here, we describe a case of refractory acquired FVIII inhibitor in a patient with primary pemphigus and its successful treatment with low-dose rituximab. Coagulation studies revealed a prolonged activated partial thromboplastin time, which could not be corrected with the mixing test. At the same time, the FVIII activity level was significantly reduced, and the FVIII inhibitor titer was elevated. A treatment regimen with prednisolone/cyclophosphamide followed by prednisolone/cyclosporine was used. The patient temporarily responded but then became resistant to these medicines. However, subsequent treatment with low-dose rituximab achieved considerable clinical and laboratory improvement in the same patient. Follow-up at 6 months revealed a low level of residual FVIII inhibitor activity with normal coagulation functions. No drug-related side effects were detected. In conclusion, our results indicate that low-dose rituximab might be an effective and safe treatment for patients with acquired FVIII inhibitor.

[Effect of arsenic trioxide and daunorubicin on procoagulant activity of acute promyelocytic leukemia cells].

OBJECTIVE: To explore the effect of arsenic trioxide (ATO) and daunorubicin (DNR) on phosphatidylserine (PS) exposure and related procoagulant activity of acute promyelocytic leukemia (APL) cells. METHODS: Mononuclear cell and neutrophil isolated from whole blood of 12 healthy volunteers were used as control group while APL cells obtained from 12 newly diagnosed APL patients at First Affiliated Hospital, Harbin Medical University from March 2007 to February 2009 were used as experimental group. APL cells were treated with 1 µmol/L ATO and 1 µmol/L DNR for 24 h. PS exposure of APL cells were measured by flow cytometry and confocal microscopy. And the related procoagulant activity was detected by the assays of coagulation time and coagulation factor formation. Lactadherin was used as a probe for PS exposure and anticoagulant on the cells of 12 APL patients. RESULTS: ATO induced a decrease of PS exposure on APL cells by flow cytometry and no staining with lactadherin was observed under confocal microscopy. However, DNR induced the significantly elevated PS exposure and staining green with a rim pattern on membrane of APL cells was obtained. Coagulation time was (180 ± 25) s and (220 ± 41) s before and after treatment with ATO, respectively (P < 0.05). The formation of coagulation factors decreased after treatment with ATO (P < 0.05). While coagulation time was (180 ± 25) s and (80 ± 20) s before and after treatment with DNR, respectively (P < 0.05). The formation of coagulation factors increased after treatment with DNR (all P < 0.05). Lactadherin inhibited the procoagulant activities of DNR-treated APL cells (all P < 0.05). CONCLUSIONS: Procoagulant activity is positively correlated with the exposed PS of APL cells. ATO and DNR inhibited and enhanced procoagulant activity with decreased and increased PS exposure, respectively.

Procoagulant activity and phosphatidylserine of amniotic fluid cells.

Amniotic fluid (AF) may induce disseminated intravascular coagulation (DIC) when it enters maternal circulation by breaching the placental-maternal circulation barrier. The precise mechanism of the procoagulant activity of AF is unclear, but tissue factor (TF) has been proposed to be the main cause. As one constituent of AF, AF cells accumulate and undergo apoptosis continuously. Therefore, we speculate that AF cells have procoagulant activity due to the externalisation of phosphatidylserine (PS). The present study aims to demonstrate that, in addition to TF, the PS that is externalised on AF cells is important for the procoagulant activity of AF. Ten AF samples from parturient women were analysed using lactadherin as the probe for PS. Anti-TF antibody also was used to identify TF and its associated coagulation functions in AF cells. Normal platelets, neutrophils, and lymphocytes were harvested as controls. Confocal microscopy and flow cytometry was used to assess PS expression on AF cells. The procoagulant activity of AF cells was demonstrated by a plasma coagulation assay and further confirmed by factor Xase/prothrombinase assays. PS and TF were present on most AF cells, providing substantial procoagulant activity. Furthermore, factor Xase and prothrombinase assays showed that AF cells substantially enforced the activation of factor X and prothrombin. PS on AF cells is an important procoagulant source for AF. Lactadherin is an ideal anticoagulant for inhibiting the procoagulant activity of AF cells.

Reticulate hybridization of Alpinia (Zingiberaceae) in Taiwan.

Reticulate hybridization is a complicated and creative mechanism in plant evolution that can cause interference in phylogenetic studies. Based on observations of intermediate morphology, low pollen fertility, and overlapping distributions of putative parent species, Yang and Wang (Proceedings of the cross-strait symposium on floristic diversity and conservation. National Museum of Natural Science, Taichung, Taiwan, pp 183-197, 1998) first proposed reticulate hybridization of Alpinia in Taiwan. In the present study, molecular tools were used to explore relationships between four parental species and their homoploidy hybrids, and the impact of hybridization on phylogeny reconstruction. Based on DNA markers, maternal heritance of the chloroplast genome, and additivity of nuclear ribosomal internal transcribed spacer, the present results provide strong support for the hybridization hypothesis. Co-existence of parental ribotypes within hybrids revealed that these hybridization events were current, while reciprocal and introgressive hybridization were inferred from chloroplast DNA data. Furthermore, iterative hybridizations involving more than two parental species may occur in notorious hybrid zones. Ecological, phenological, and physiological evidence provides insight into why such frequent hybridization occurs in Taiwanese Alpinia. In the phylogenetic tree of the Zerumbet clade reconstructed in this study, the chloroplast sequences from one hybrid species were not grouped into a subclade, implying instability caused by hybridization. Failure to find morphological apomorphies and biogeographical patterns in this clade was likely partially due to reticulate hybridization.

Time course of arsenic species in red blood cells of acute promyelocytic leukemia (APL) patients treated with single agent arsenic trioxide.

BACKGROUND: Arsenic trioxide (ATO) is widely applied to treat acute promyelocytic leukemia (APL). To elucidate metabolism and toxicity of arsenic, we analyzed time course of arsenic species in red blood cells (RBCs) of APL patients. METHODS: Nine APL patients received ATO (0.16 mg/kg/day) through 18-h infusion. Blood was collected before daily administration (days 2 to 9), and at different time points on day 8. Inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) were detected by HPLC-ICP-MS. RESULTS: Arsenic species reached Cmax at 18 h on day 8. Arsenicals gradually accumulated during days 2 to 9, whereas their percentages remained almost constant. The general trend in red blood cells (RBCs) was iAs > MMA > DMA. MMA was consistently the predominant methylated arsenic metabolite in RBCs. iAs, MMA, and tAs (tAs = iAs + DMA + MMA) concentrations (P < 0.0001), MMA/DMA ratios (P = 0.0016) and iAs% (P = 0.0013) were higher in RBCs than in plasma. CONCLUSIONS: Time course of arsenic species reveal kinetic characteristic of ATO metabolites in RBCs. Arsenic species accumulated with administration frequency. Arsenic species in RBCs were remarkably different from those in plasma. Time course of arsenic species in RBCs is important in ATO clinical application.

Simvastatin reverses multiple myeloma serum-induced prothrombotic phenotype in endothelial cells via ERK 1/2 signalling pathway.

: The introduction of new agents in multiple myeloma therapy has increased the overall response rate and improved clinical outcomes, but the increased risk of thrombotic complications impairs the quality of life of patient and the optimal thromboprophylaxis remains unknown. Increasing evidence has shown that statins can prevent venous thrombosis. Hence, we investigated the effects of simvastatin on multiple myeloma serum-related haemostatic imbalance in endothelial cells in vitro. The effects of simvastatin on procoagulant and anticoagulant protein expression were assessed on mixed multiple myeloma serum-treated human umbilical vein endothelial cells (HUVECs). The activity of these proteins was measured by thrombin generation and protein C activation assay. Then, the effects of extracellular signal-regulated kinase (ERK) 1/2 on endothelial activation were assessed by western blot and inhibition assay. We found that simvastatin inhibited multiple myeloma serum-induced expression of procoagulant protein tissue factor and phosphatidylserine and generation of thrombin on HUVECs. In contrast, simvastatin increased multiple myeloma serum-inhibited expression of anticoagulant protein endothelial protein C receptor and activation of protein C on HUVECs. Moreover, simvastatin reversed the multiple myeloma serum-induced prothrombotic phenotype, at least in part, via the inhibition of ERK 1/2 activation in endothelial cells. This study supports the beneficial effects of simvastatin on multiple myeloma serum-induced endothelial haemostatic imbalance, which suggests that simvastatin may serve as a new and appropriate antithrombotic approach for multiple myeloma patients.

Arsenic trioxide-based therapy is suitable for patients with psoriasis-associated acute promyelocytic leukemia - A retrospective clinical study.

OBJECTIVE: Many patients with psoriasis have developed acute promyelocytic leukemia (APL) whereas few reports on psoriasis-associated APL were found in the published literature. This study was aimed to study the etiology, clinical characteristics, and prognosis of psoriasis-associated APL and to map a suitable treatment regime for this condition. METHODS: This study retrospectively analyzed the clinical data of 17 patients with psoriasis-associated APL diagnosed and treated in our hospital in the past decade. RESULTS: The 17 patients accounted for 8.3% of the total patients diagnosed with de novo APL during the same period in our hospital. Their clinical characteristics of APL were similar to those of general APL. Four patients had a definite history of taking bimolane. All patients received arsenic trioxide (ATO)-based remission induction and postremission treatment. After induction, 15 patients (88%) achieved hematologic complete remission. With a median follow-up of 27 months, the 3-year estimates of overall survival were 77.2% ± 12.4% and the 3-year estimates of event-free survival were 70.6% ± 13.5%. In addition, the ATO-based remission induction and postremission treatment significantly improved psoriasis symptoms in 83 and 85.7% of patients, respectively. Through the final follow-up, no chronic arsenicosis or secondary malignancy was observed. CONCLUSIONS: Psoriasis patients are at high risk for APL. The increased risk is most likely associated with the genetic background and bimolane treatment. The ATO-based therapy is especially suitable for patients with psoriasis-associated APL. Our study also brings a new treatment option for psoriasis.

Thalidomide and multiple myeloma serum synergistically induce a hemostatic imbalance in endothelial cells in vitro.

BACKGROUND: Thalidomide (Thal) treatment of patients with multiple myeloma (MM) is associated with vascular thrombosis, but the underlying mechanism is unknown. OBJECTIVES: To evaluate the hypothesis that Thal, dexamethasone (Dex) and MM serum perturb the hemostatic balance on human umbilical vein endothelial cells (HUVECs). METHODS: Drugs with or without the serum of MM patients or healthy controls were incubated with HUVECs. Analyses of phosphatidylserine (PS), tissue factor (TF), endothelial protein C receptor (EPCR) and thrombomodulin (TM) were performed using flow cytometry. The production of thrombin and activated protein C (APC) were measured by chromogenic assay. The roles of IL-6 and TNFα in regulating these indicators were also investigated. RESULTS: We found that Thal or Dex alone could not increase TF and PS expression in HUVECs. However, when pretreated with MM serum, their expression was significantly increased by either Thal or Dex. Concurrent changes were also detected in thrombin generation. In contrast, Thal and Dex had a direct inhibitory effect on the expression of EPCR and TM, and this inhibitory effect was especially significant when MM serum was added. The generation of APC paralleled the expression of EPCR and TM. All of the above outcomes were reversed to a variable extent by anti-IL-6R and anti-TNFα antibodies. CONCLUSIONS: These findings suggest Thal may act as a procoagulant by altering the balance between procoagulant and anticoagulant proteins on the surface of HUVECs, thereby contributing to thrombogenesis. MM serum plays a synergistic role in this process.

LINE-1 hypomethylation is associated with the risk of coronary heart disease in Chinese population.

BACKGROUND: Global methylation level in blood leukocyte DNA has been associated with the risk of coronary heart disease (CHD), with inconsistent results in various populations. Similar data are lacking in Chinese population where different genetic, lifestyle and environmental factors may affect DNA methylation and its risk relationship with CHD. OBJECTIVES: To examine whether global methylation is associated with the risk of CHD in Chinese population. METHODS: A total of 334 cases with CHD and 788 healthy controls were included. Global methylation in blood leukocyte DNA was estimated by analyzing LINE-1 repeats using bisulfite pyrosequencing. RESULTS: In an initial analysis restricted to control subjects, LINE-1 level reduced significantly with aging, elevated total cholesterol, and diagnosis of diabetes. In the case-control analysis, reduced LINE-1 methylation was associated with increased risk of CHD; analysis by quartile revealed odds ratios (95%CI) of 0.9 (0.6-1.4), 1.9 (1.3-2.9) and 2.3 (1.6-3.5) for the third, second and first (lowest) quartile (Ptrend < 0.001), respectively, compared to the fourth (highest) quartile. Lower (

Procoagulant activity and cellular origin of microparticles in human amniotic fluid.

INTRODUCTION: Amniotic fluid contains various procoagulant factors involved in intro-vascular amniotic fluid-induced coagulopathies. During the progression of normal pregnancy, microparticles would be shed off from cells and accumulate in amniotic fluid over time. In this study, our aims were to investigate the cellular origin and procoagulant entity of these microparticles. MATERIALS AND METHODS: Twenty amniotic fluid samples from healthy parturient women were collected, and the microparticles were isolated and stained with phycoerythrin-labeled antibodies to CD138, CD41a, CD144 and CD11b to identify their cellular origin. Their phosphatidylserine and tissue factor expression levels were quantified with fluorescein isothiocyanate-labeled annexin V and anti-tissue factor antibody staining. Their procoagulant activity was tested with plasma coagulation assay and factor Xase and prothrombinase assays. RESULTS: Phenotypic analysis showed 36.8% and 33.8% of amniotic fluid microparticles positive for CD138 and CD11b, respectively, indicating their epithelial cell or leukocyte origin. Of these microparticles, 66.3±5.9% expressed phosphatidylserine while 37.4±4.1% expressed tissue factor. In addition, amniotic fluid microparticles could significantly shorten the plasma coagulation time and increase the production of factor Xa and thrombin. Inhibition assays with annexin V and anti-tissue factor antibody confirmed the coagulation effects of amniotic fluid microparticles. CONCLUSION: The microparticles derived from epithelial and leukocytes may be a mechanism of amniotic fluid-induced coagulopathies.

Endothelial cell phagocytosis of senescent neutrophils decreases procoagulant activity.

Abundant senescent neutrophils traverse the vascular compartment and may contribute to pathologic conditions. For example, they become procoagulant when undergoing apoptosis and may contribute to thrombosis or inflammation. Our previous studies demonstrated a dominant clearance pathway in which the neutrophils can be phagocytosed by liver macrophages. The aim of this study was to explore an alternate pathway of neutrophil clearance by endothelial cells. Phagocytosis of the neutrophils by endothelial cells was performed using various experimental approaches includingflow cytometry, confocal microscopy and electron microscopy assays in vitro and in vivo. Procoagulant activity of cultured neutrophils was evaluated by coagulation time, factor Xase and prothrombinase assays. Lactadherin functioned as a novel probe for the detection of phosphatidylserine on apoptotic cells, an opsonin (bridge) between apoptotic cell and phagocyte for promoting phagocytosis, and an efficient anticoagulant for inhibition of factor Xase and thrombin formation. When cultured, purified human neutrophils spontaneously entered apoptosis and developed procoagulant activity that was directly related to the degree of phosphatidylserine exposure. Co-culture of aged neutrophils and endothelial cells resulted in phagocytosis of the neutrophils and prolonged coagulation time. Lactadherin diminished the procoagulant activity and increased the rate of neutrophil clearance. In vivo, neutrophils were sequestered by endothelial cells after blockade of Kupffer cells, a process that was dependent upon both phosphatidylserine exposure and P-selectin expression. Thus, the ability of endothelial cells to clear senescent neutrophils may limit the procoagulant and/or inflammatory impact of these cells.

[Expression and procoagulant activity of phosphatidylserine on the normal blood cells].

OBJECTIVE: To investigate the expression and procoagulant activity of phosphatidylserine (PS) on the normal peripheral blood cells of adults. METHODS: Normal peripheral blood samples were collected from 10 healthy volunteers (5 ml from each volunteer), platelets, neutrophils, lymphocytes and erythrocytes were isolated. The expression and procoagulant activity of PS on normal blood cells were identified by flow cytometry, inhibition test with lactadherin as PS probe and coagulation anticoagulant, respectively. RESULTS: There was PS expression on a few normal blood cells (9.1%, 5.4%, 3.9% and 3.2% in platelets, neutrophils, lymphocytes and erythrocytes, respectively). The PS on these normal blood cells in vitro showed significant procoagulant activity. The plasma recalcification time was shortened by 47%, 36.5%, 25% and 12.5% by platelets, neutrophils, lymphocytes and erythrocytes, respectively; the formation of factor Xa (through both intrinsic and extrinsic pathways) and thrombin was also increased by 13% - 26% by platelets, neutrophils, lymphocytes and erythrocytes, respectively. CONCLUSION: The PS on normal blood cells in vivo may play a crucial role in the coagulation cascade.

Balloon dilatation in management of postoperative airway obstruction due to tracheal bronchus associated with right main bronchial stenosis: emphasizing the role of three-dimensional computed tomography on preoperative evaluation.

Three-dimensional computed tomography (3D-CT) not only allows accurate preoperative delineation of the lesions but also provides precise pathomechanic diagnosis for planning the most effective treatment to avoid respiratory compromise. In a 10-month-old baby girl, who was ventilator-dependent after successful correction of double outlet right ventricle (DORV), flexible fiberoptic bronchoscopy (FFB) revealed the new formation of postoperative airway obstruction over the right main bronchus (RMB) and obstructed right tracheal bronchus (RTB). 3D-CT demonstrated tracheobronchial obstruction (TBO) was caused by the dilated ascending aorta (AAo) and right pulmonary artery (RPA). Sequential treatments including artery pexy of AAo and RPA and balloon dilatation (BD) of the stenotic RTB and RMB had successfully restored the airway patency. The patient was successfully weaned from ventilator 2 days after treatments and has shown no respiratory difficulty thus far. Thus, the impact of preoperative 3D-CT on planning treatment cannot be emphasized.

Hipometilação do LINE-1 está Associada ao Risco de Doença Cardíaca Coronariana na População Chinesa / LINE-1 Hypomethylation is Associated with the Risk of Coronary Heart Disease in Chinese Population

Fundamentos: O nível de metilação global do ADN de leucócitos no sangue tem sido associado ao risco de doença arterial coronariana (DAC), com resultados inconsistentes em diferentes populações. Faltam dados semelhantes da população chinesa, onde diferentes fatores genéticos, de estilo de vida e ambientais podem afetar a metilação do ADN e sua relação com o risco de DCC. Objetivos: Analisar se a metilação global está associada ao risco de doença coronariana na população chinesa. Métodos: Foram incluídos um total de 334 casos de DCC e 788 controles saudáveis. A metilação global do ADN de leucócitos de sangue foi estimada por meio da análise das repetições do LINE-1 usando pirosequenciamento de bissulfito. Resultados: Em uma análise inicial restrita aos controles o nível do LINE-1 diminui significativamente com a idade avançada, colesterol total elevado, e diagnóstico de diabetes. Na análise de caso-controle, a redução da metilação do LINE-1 foi associada ao aumento do risco de DCC, tendo a análise por quartil revelado uma odds ratio (IC 95%) de 0,9 (0,6-1,4), 1,9 (1,3-2,9) e 2,3 (1,6 3.5) para o terceiro, segundo e primeiro (o mais baixo) quartil (P da tendência < 0,001), respectivamente, em comparação com o quarto (o mais alto) quartil. A metilação inferior (< mediana) do LINE-1 esteve associada a 2,2 vezes (IC 95% = 1,7-3,0) o aumento de risco de doença coronariana. As estimativas de risco de DCC menores relacionadas com o LINE-1 tenderam a ser mais fortes entre os indivíduos com maior tercil de homocisteína (P interação = 0,042) e naqueles com diagnóstico de hipertensão arterial (P interação = 0,012). Conclusão: A hipometilação do LINE-1 está ...

Background: Global methylation level in blood leukocyte DNA has been associated with the risk of coronary heart disease (CHD), with inconsistent results in various populations. Similar data are lacking in Chinese population where different genetic, lifestyle and environmental factors may affect DNA methylation and its risk relationship with CHD. Objectives: To examine whether global methylation is associated with the risk of CHD in Chinese population. Methods: A total of 334 cases with CHD and 788 healthy controls were included. Global methylation in blood leukocyte DNA was estimated by analyzing LINE-1 repeats using bisulfite pyrosequencing. Results: In an initial analysis restricted to control subjects, LINE-1 level reduced significantly with aging, elevated total cholesterol, and diagnosis of diabetes. In the case-control analysis, reduced LINE-1 methylation was associated with increased risk of CHD; analysis by quartile revealed odds ratios (95%CI) of 0.9 (0.6-1.4), 1.9 (1.3-2.9) and 2.3 (1.6-3.5) for the third, second and first (lowest) quartile (Ptrend < 0.001), respectively, compared to the fourth (highest) quartile. Lower (<median) LINE-1 methylation was associated with a 2.2-fold (95%CI = 1.7-3.0) increased risk of CHD. The lower LINE-1-related CHD risk estimates tended to be stronger among subjects with the highest tertile of homocysteine (Pinteraction = 0.042) and those with diagnosis of hypertension (Pinteraction = 0.012). Conclusion: LINE-1 hypomethylation is associated with the risk of CHD in Chinese population. Potential CHD risk factors such as older age, elevated total cholesterol, and diagnosis of diabetes may have impact on global DNA methylation, whereby exerting their effect on CHD risk. .