DPPA4 modulates chromatin structure via association with DNA and core histone H3 in mouse embryonic stem cells

Developmental pluripotency associated 4 (DPPA4) is one of the uncharacterized genes that is highly expressed in embryonic stem (ES) cells. DPPA4 is associated with active chromatin and involved in the pluripotency of mouse ES cells. However, the biological function of DPPA4 remains poorly understood. In this study, we performed fluorescence recovery after photobleaching (FRAP) analysis to examine the dynamics of DPPA4 in ES cells. FRAP analysis showed that the mobility of DPPA4 is similar to that of histone H1. In addition, biochemical analysis with purified proteins and immunoprecipitation analysis showed that DPPA4 directly binds to both DNA and core histone H3. The analysis using truncated proteins indicated that DPPA4 is associated with DNA via the N‐terminal region and histone H3 via the C‐terminal region. In vitro assembled chromatin showed resistance to micrococcal nuclease (MNase) digestion in the presence of DPPA4. Moreover, MNase assay and FRAP analysis with the truncated proteins implies that DPPA4 binding to both DNA and histone H3 is necessary for the chromatin structure resistant to MNase and for the proper localization of DPPA4 in ES cell nuclei. These results suggest that DPPA4 modulates the chromatin structure in association with DNA and histone H3 in ES cells.     

Enhanced antitumor effect of anti‐tissue factor antibody‐conjugated epirubicin‐incorporating micelles in xenograft models

For the creation of a successful antibody–drug conjugate (ADC), both scientific and clinical evidence has indicated that highly toxic anticancer agents (ACA) should be conjugated to a monoclonal antibody (mAb) to administer a reasonable amount of ADC to patients without compromising the affinity of the mAb. For ordinary ACA, the conjugation of a mAb to ACA‐loaded micellar nanoparticles is clinically applicable. Tissue factor (TF) is often overexpressed in various cancer cells and tumor vascular endothelium. Accordingly, anti‐TF‐NC‐6300, consisting of epirubicin‐incorporating micelles (NC‐6300) conjugated with the F(ab')₂ of anti‐TF mAb was developed. The in vitro and in vivo efficacy and pharmacokinetics of anti‐TF‐NC‐6300 were compared to NC‐6300 using two human pancreatic cancer cell lines, BxPC3 (high TF expression) and SUIT2 (low TF expression), and a gastric cancer cell line, 44As3 (high TF expression). The intracellular uptake of epirubicin was faster and greater in BxPC3 cells treated with anti‐TF‐NC‐6300, compared with NC‐6300. Anti‐TF‐NC‐6300 showed a superior antitumor activity in BxPC3 and 44As3 xenografts, compared with NC‐6300, while the activities of both micelles were similar in the SUIT2 xenograft. A higher tumor accumulation of anti‐TF‐NC‐6300 compared to NC‐6300 was seen, regardless of the TF expression levels. However, anti‐TF‐NC‐6300 appeared to be localized to the tumor cells with high TF expression. These results indicated that the enhanced antitumor effect of anti‐TF‐NC6300 may be independent of the tumor accumulation but may depend on the selective intratumor localization and the preferential internalization of anti‐TF‐NC‐6300 into high TF tumor cells.     

A New Non-Invasive Continuous Cardiac Output Trend Solely Utilizing Routine Cardiovascular Monitors

Objective. Three of the us developed a new non-invasive continuous cardiac output (CCO) measurement method utilizing routine clinical monitors based on the pulse-contour analysis combined with pulse wave transit time (PWTT). Using pulmonary artery catheter (CCOpa), we compared this estimated CCO (esCO) with the thermodilution CCO early after cardiac surgery, and tested whether the esCO method has potential of being an alternative measure of CCO. Methods. Thirty-six patients without continued arrhythmias were studied. esCO was computed using electrocardiogram (ECG) monitor, arterial pressure monitor and pulse-oximetry system. Both sets of data (esCO and CCOpa), by averaging the results of the preceding 10 min, were compared at 30-min intervals throughout the 15.8± 3.3 h (S.D.) of study. Bland–Altman plots and correlation analysis were used for statistical comparison. Results. A total of 981 paired sets of data (89.9%) among 1093 measurements were compared in the absence of displacement of either pulse-oximetry or ECG probes and/or inaccurate detection of R wave. The difference between esCO and CCOpa results was −0.06 ± 0.82 L/min (S.D.), and there was a linear correlation between them (r = 0.80, p < 0.0001). The difference between them was 0.00± 0.48 L/min at the first 1 h, which remained unchanged throughout 20 h after the start of measurement. Conclusions. The results demonstrate that esCO has a close correlation with the CCOpa, even though the two methods are not interchangeable. The results suggest that esCO method has potential of being an alternative non-invasive cardiac output trend, unless there are apparent arrhythmias.     

A case of fluminant myocarditis with fetal pulmonary edema even after introduction of bi-ventricular assist devices

A 15-year-old man developed cardiopulmonary dysfunction 4 days after flu-like symptom, and was transfered to our hospital and diagnosed as a fulminant myocarditis (FM). Intraaortic ballon pumping (IABP) and percutaneous cardiopulmonary support (PCPS) were immediately initiated. However, cardiac function did not recover until 7 days after admission to the ICU, and bilateral ventricular assist devices (BiVAD) were introduced with extracorporeal membrane oxygenation (ECMO). Right ventricular assist device (RVAD) with ECMO was established by right atrial blood withdrawal and pulmonary arterial blood supply using centrifugal pump. After operation of BiVAD, to main LVAD flow, frequent blood-and-fluids volume loading and increase in RVAD flow were necessary due to postoperative bleeding and massive foamy sputum. However, even after hemostasis had been established, the pulmonary edema continued and it was difficult to maintain LVAD flow because of endless transudation from the lungs. Eventually, he developed MOF and passed away 9 days after the admission to ICU. As in cases of end-stage dilated cardiomyopathy, outflow of RVAD into the left atrium instead of the pulmonary artery was demonstrated effective in avoiding trans-pulmonary leakage, and outflow of RVAD into the left atrium may be beneficial to patients with FM who need BiVAD but suffered severe pulmonary edema.     

Novel autoantibodies against 7SL RNA in patients with polymyositis/dermatomyositis

OBJECTIVE: Autoantibodies against signal recognition particle (SRP) are detected in patients with polymyositis/dermatomyositis (PM/DM). The SRP consists of 7SL RNA and 6 protein components. We examined autoantibodies against deproteinized 7SL RNA in PM/DM patients with anti-SRP antibodies and evaluated the association of anti-7SL RNA antibodies with PM/DM clinically and serologically. METHODS: Sera from 10 Japanese and 22 North American PM/DM patients with anti-SRP antibodies were tested for the presence of anti-7SL RNA antibodies, using the sera to immunoprecipitate deproteinized RNA extracts derived from HeLa cells. RESULTS: The immunoprecipitation analysis indicated that 5 Japanese (50%) and one North American (5%) patient with anti-SRP antibodies had novel autoantibodies against deproteinized 7SL RNA. The frequency of anti-7SL RNA antibodies was significantly higher in Japanese than North American patients (p = 0.006). The presence of anti-7SL RNA antibodies appeared to be associated with DM (2 patients) and finger swelling (2 PM patients). The seasonal onset of the disease was different (p = 0.008) for Japanese PM/DM patients with anti-7SL RNA antibodies, who developed the disease between October and January (mean month November; p = 0.01) from that of patients without these antibodies, who developed it between June and August (mean month July; p = 0.01). CONCLUSION: Novel autoantibodies against 7SL RNA were identified in patients with PM/DM, and the presence of these antibodies was correlated to ethnic background, clinical features, and season of disease onset. These findings indicated that autoantibodies against 7SL RNA are a novel serological marker for a subset of PM/DM cases.     

Coexistence of nodular regenerative hyperplasia of the liver and pulmonary arterial hypertension in patients with connective tissue diseases: report of three cases and review of the literature

Nodular regenerative hyperplasia of the liver (NRH) is known to be a rare condition in patients with connective tissue diseases (CTD). In this report, we document three patients with CTD who had both NRH and pulmonary hypertension (PH). All three patients developed PH during their course and thereafter developed NRH. The clinical course of these patients suggests that circulatory disturbance caused by PH might be a trigger for NRH.