Variant-derived SARS-CoV-2 spike protein does not directly cause platelet activation or hypercoagulability.

Thrombosis has been associated with severity and mortality in COVID-19. SARS-CoV-2 infects the host via its spike protein. However, direct effects of spike proteins from SARS-CoV-2 variants on platelet activity and coagulability have not been examined. An ethically approved ex vivo study was performed under a preplanned power analysis. Venous blood was collected from 6 healthy subjects who gave prior written consent. The samples were divided into 5 groups: without spike proteins (group N) and with spike proteins derived from alpha, beta, gamma, and delta SARS-CoV-2 variants (groups A, B, C, and D, respectively). Platelet aggregability, P-selectin expression, platelet-associated complement-1 (PAC-1) binding, platelet count, and mean platelet volume (MPV) were measured in all 5 groups, and thromboelastography (TEG) parameters were measured in groups N and D. The % change in each parameter in groups A to D was calculated relative to the value in group N. Data were analyzed by Friedman test, except for TEG parameters, which were evaluated by Wilcoxon matched pairs test. P < 0.05 was considered significant. This study included 6 participants based on a power analysis. There were no significant differences in platelet aggregability under stimulation with adenosine diphosphate 5 µg/ml, collagen 0.2 or 0.5 µg/ml, and Ser-Phe-Leu-Leu-Arg-Asn-amide trifluoroacetate salt (SFLLRN) 0.5 or 1 µM in groups A-D compared to group N. There were also no significant differences in P-selectin expression and PAC-1 binding under basal conditions or SFLLRN stimulation, and no significant differences in platelet count, MPV and TEG parameters. Platelet hyperactivity and blood hypercoagulability have been reported in COVID-19 patients, but spike proteins at 5 µg/ml from SARS-CoV-2 variants (alpha, beta, gamma, delta) did not directly cause these effects in an ex vivo study. This study was approved by the Ethics Committee of Kyoto University Hospital (R0978-1) on March 06, 2020.

Platelet function of whole blood after short-term cold storage: A prospective in vitro observational study.

BACKGROUND: There is no standardized storage temperature of whole blood for acute normovolemic hemodilution (ANH). STUDY DESIGN AND METHODS: We conducted a prospective observational study to examine the difference in platelet function between short-term whole blood storage at 4 and 22°C. Venous blood (40 ml) was collected from seven healthy subjects who gave prior written consent. The samples were divided into three groups: before storage (group Pre), cold (4°C) storage (group C), and room temperature (22°C) storage (group R). Groups C and R were tested after 6 h of blood storage. Platelet aggregability, platelet factor 4 (PF4), ß-thromboglobulin (ß-TG), P-selectin expression, pH, PO2 , PCO2 , glucose, lactate, blood count, and thromboelastography (TEG) parameters were measured. The percentage change in each parameter in groups C and R was calculated using the value in group Pre as a reference. These data were then compared between groups C and R using a Wilcoxon matched pairs test. p < 0.05 was considered to be statistically significant. RESULTS: Compared with group R, group C showed significantly higher platelet aggregability with adenosine diphosphate (ADP) 2, 4, and 6 µM (all p = 0.016) and collagen 1 µg/ml (p = 0.047) stimulation, and significantly lower PF4 and ß-TG elevation (both p = 0.031), glucose consumption (p = 0.031), and lactate production (p = 0.016). The ADP channel in TEG showed a significant increase in platelet aggregation rate in group C compared to group R. DISCUSSION: Cold storage of whole blood in ANH may provide improved storage conditions for platelets and contribute to improved hemostasis compared to room temperature storage.

The stoichiometric interaction model for mesoscopic MD simulations of liquid-liquid phase separation.

Liquid-liquid phase separation (LLPS) has received considerable attention in recent years for explaining the formation of cellular biomolecular condensates. The fluidity and the complexity of their components make molecular simulation approaches indispensable for gaining structural insights. Domain-resolution mesoscopic model simulations have been explored for cases in which condensates are formed by multivalent proteins with tandem domains. One problem with this approach is that interdomain pairwise interactions cannot regulate the valency of the binding domains. To overcome this problem, we propose a new potential, the stoichiometric interaction (SI) potential. First, we verified that the SI potential maintained the valency of the interacting domains for the test systems. We then examined a well-studied LLPS model system containing tandem repeats of SH3 domains and proline-rich motifs. We found that the SI potential alone cannot reproduce the phase diagram of LLPS quantitatively. We had to combine the SI and a pairwise interaction; the former and the latter represent the specific and nonspecific interactions, respectively. Biomolecular condensates with the mixed SI and pairwise interaction exhibited fluidity, whereas those with the pairwise interaction alone showed no detectable diffusion. We also compared the phase diagrams of the systems containing different numbers of tandem domains with those obtained from the experiments and found quantitative agreement in all but one case.

Anti-Dementia Drug Persistence Following Donepezil Initiation Among Alzheimer's Disease Patients in Japan: LIFE Study.

BACKGROUND: Donepezil is frequently used to treat Alzheimer's disease (AD) symptoms but is associated with early discontinuation. Determining the persistence rates of anti-dementia drug use after donepezil initiation may inform the development and improvement of treatment strategies, but there is little evidence from Japan. OBJECTIVE: To determine anti-dementia drug persistence following donepezil initiation among AD patients in Japan using insurance claims data. METHODS: Insurance claims data for AD patients with newly prescribed donepezil were obtained from 17 municipalities between April 2014 and October 2021. Anti-dementia drug persistence was defined as a gap of ≤60 days between the last donepezil prescription and a subsequent prescription of donepezil, another cholinesterase inhibitor, or memantine. Cox proportional hazards models were used to analyze the association between care needs levels and discontinuation. RESULTS: We analyzed 20,474 AD patients (mean age±standard deviation: 82.2±6.3 years, women: 65.7%). The persistence rates were 89.1% at 30 days, 79.4% at 90 days, 72.6% at 180 days, 64.5% at 360 days, and 58.3% at 540 days after initiation. Among the care needs levels, the hazard ratio (95% confidence interval) for discontinuation was 1.01 (0.94-1.07) for patients with support needs, 1.12 (1.06-1.18) for patients with low long-term care needs, and 1.31 (1.21-1.40) for patients with moderate-to-high long-term care needs relative to independent patients. CONCLUSION: Japanese AD patients demonstrated low anti-dementia drug persistence rates that were similar to those of other countries. Higher long-term care needs were associated with discontinuation. Further measures are needed to improve drug persistence in AD patients.

Agreement between continuous cardiac output measured by the fourth-generation FloTrac/Vigileo system and a pulmonary artery catheter in adult liver transplantation.

In liver transplantation for end-stage liver failure, monitoring of continuous cardiac output (CCO) is used for circulatory management due to hemodynamic instability. CCO is often measured using the minimally invasive FloTrac/Vigileo system (FVS-CCO), instead of a highly invasive pulmonary artery catheter (PAC-CCO). The FVS has improved accuracy due to an updated cardiac output algorithm, but the effect of this change on the accuracy of FVS-CCO in liver transplantation is unclear. In this study, we assessed agreement between fourth-generation FVS-CCO and PAC-CCO in 20 patients aged ≥ 20 years who underwent scheduled or emergency liver transplantation at Kyoto University Hospital from September 2019 to June 2021. Consent was obtained before surgery and data were recorded throughout the surgical period. Pearson correlation coefficient (r), Bland-Altman and 4-quadrant plot analyses were performed on the extracted data. A total of 1517 PAC-CCO vs. FVS-CCO data pairs were obtained. The mean PAC-CCO was 8.73 L/min and the mean systemic vascular resistance was 617.5 dyne·s·cm-5, r was 0.48, bias was 1.62 L/min, the 95% limits of agreement were - 3.04 to 6.27, and the percentage error was 54.36%. These results show that agreement and trending between fourth-generation FVS-CCO and PAC-CCO are low in adult liver transplant recipients.

Effects of whole blood storage in a polyolefin blood bag on platelets for acute normovolemic hemodilution.

Acute normovolemic hemodilution (ANH) is a potential transfusion method for platelets, as well as for red blood cells. However, previous studies have shown that whole blood storage in ANH decreases platelet aggregability by 14.7-76.3% and that this decrease is not recovered by reinfusion. We investigated whether a new whole blood storage method for 6 h using a polyolefin bag, based on the platelet concentrates storage method, would maintain platelet function better than the conventional method using a polyvinyl chloride bag. We demonstrated that storage of whole blood in a polyolefin bag maintained ADP-induced aggregation rates at more than twofold higher than those in a polyvinyl chloride bag, and also significantly suppressed P-selectin expression, a platelet activation marker (ADP-induced aggregation rates: 24.6 ± 5.1% vs. 51.7 ± 11.5%, p = 0.002; P-selectin expression; 50.3 ± 8.4MFI vs. 31.6 ± 9.3MFI, p = 0.018). These results could be attributed to the high gas permeability of polyolefin, which lowered PCO2 and maintained a high pH with or without agitation. There were no significant changes in platelet count and red blood cell parameters due to the storage methods. Our results suggest that ANH using polyolefin bags is advantageous in improving hemostatic function compared to the conventional method.

Rocuronium Has a Suppressive Effect on Platelet Function via the P2Y12 Receptor Pathway In Vitro That Is Not Reversed by Sugammadex.

Rocuronium is an aminosteroid nondepolarizing neuromuscular blocker that is widely used for anesthesia and intensive care. In this study, we investigated the effect of rocuronium on human platelet functions in vitro. The effects of rocuronium on platelet aggregation, P-selectin expression, and cyclic adenosine monophosphate (cAMP) levels in platelets were measured using an aggregometer, an enzyme immunoassay, and flow cytometry, respectively. Rocuronium inhibited ADP-induced platelet aggregation, P-selectin expression and suppression of cAMP production. These effects were not antagonized by equimolar sugammadex, a synthetic γ-cyclodextrin derivative that antagonizes rocuronium-induced muscle relaxation by encapsulating the rocuronium molecule. Morpholine, which constitutes a part of the rocuronium molecule but is not encapsulated by sugammadex, inhibited ADP-induced platelet aggregation. Vecuronium, which has a molecular structure similar to that of rocuronium but does not possess a morpholine ring, had no significant effect on ADP-induced platelet aggregation. These results indicate that rocuronium has a suppressive effect on platelet functions in vitro that is not reversed by sugammadex and suggest that this effect is mediated by blockade of the P2Y12 receptor signaling pathway via the morpholine ring of rocuronium.

Central nervous system infection following allogeneic hematopoietic stem cell transplantation.

OBJECTIVE/BACKGROUND: Here, we described the clinical characteristics and outcomes of central nervous system (CNS) infections occurring after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in a single institution over the previous 6 years. METHODS: Charts of 353 consecutive allogeneic transplant recipients were retrospectively reviewed for CNS infection. RESULTS: A total of 17 cases of CNS infection were identified at a median of 38 days (range, 10-1028 days) after allo-HSCT. Causative pathogens were human herpesvirus-6 (n=6), enterococcus (n=2), staphylococcus (n=2), streptococcus (n=2), varicella zoster virus (n=1), cytomegalovirus (n=1), John Cunningham virus (n=1), adenovirus (n=1), and Toxoplasma gondii (n=1). The cumulative incidence of CNS infection was 4.1% at 1 year and 5.5% at 5 years. CONCLUSION: Multivariate analysis revealed that high-risk disease status was a risk factor for developing CNS infection (p=.02), and that overall survival at 3 years after allo-HSCT was 33% in patients with CNS infection and 53% in those without CNS infection (p=.04).

Steroid Pulse Therapy for Blood Cell Recovery in Allogeneic Hematopoietic Stem Cell Transplantation.

OBJECTIVE: Steroid pulse therapy is used to relieve pancytopenias in our hospital and is effective in some patients. However, it is unclear which patients will benefit from such therapy. Thus, we retrospectively analyzed the clinical features of patients undergoing allogeneic hematopoietic stem cell transplantation who received steroid pulse therapy to facilitate recovery in their blood cell counts. METHODS: Between 2004 and 2012, 24 patients underwent steroid pulse therapy and the medical records of 17 of these evaluable patients (11 men, 6 women) were retrospectively reviewed. Bone marrow smears were assessed to calculate the proportion of hemophagocytic macrophages just prior to receiving pulse therapy. RESULTS: Steroid pulse therapy was started at a median of 15 days after transplantation (range, 10-28 days). The median white blood cell count was 0.02×10(3)/µL (range, 0.01-0.4×10(3)/µL). Eight patients responded to pulse therapy and subsequent engraftment was achieved in all responders. None of the patients who underwent cord blood transplantation responded to the pulse therapy. Among the non-responders, only two patients achieved engraftment and four of nine non-responders died within one month. When evaluating the efficacy of steroid pulse therapy according to the ferritin level and proportion of hemophagocytic macrophages among patients undergoing bone marrow or peripheral blood stem cell transplantation, both values were higher in responders than in non-responders. CONCLUSION: We speculate that responders have a hemophagocytic syndrome which is responsive to steroid pulse therapy. Thus, our results imply that the use of ferritin levels in combination with the proportion of hemophagocytic macrophages may be useful for the early detection of potential hemophagocytic syndrome after hematopoietic stem cell transplantation.

[Postoperative Pain after Hybrid Video-assisted Thoracic Surgery].

BACKGROUND: Hybrid video-assisted thoracic surgery (hybrid VATS), combining television monitoring and direct visualization through mini-thoracotomy, has been established as a secure and minimally invasive operation for lung cancer. This study aimed to determine postoperative pain levels after hybrid VATS in which intraoperative internal intercostal nerve block is performed. We also examined whether additional use of postoperative continuous infusion of fentanyl improves postoperative pain control. METHODS: Data from 131 patients undergoing hybrid VATS were retrospectively analyzed. Thoracoscopic, internal intercostal nerve block was performed at the end of the procedure. Postoperative pain levels after hybrid VATS, and the impact of postoperative continuous infusion of fentanyl on postoperative pain levels and the incidence of postoperative nausea and vomiting (PONV) were examined. RESULTS: 46.6% of patients experienced severe postoperative pain (numerical rating scale 7-10) after hybrid VATS. Postoperative continuous infusion of fentanyl was not associated with reduction in postoperative pain score, but was independently associated with PONV [odds ratio 3.44 (1.52-8.20); P = 0.0027]. CONCLUSIONS: Intraoperative internal intercostal nerve block did not provide sufficient analgesia after hybrid VATS. Additional use of postoperative continuous infusion of fentanyl did not reduce pain score, but increased the incidence of PONV.

Early diagnosis of Lemierre's syndrome based on a medical history and physical findings.

A 37-year-old woman presented with fever and rigor after experiencing respiratory symptoms the previous week that had resolved within a few days. On presentation, her neck was swollen along the right sternocleidomastoid muscle, and chest CT showed pulmonary septic embolisms. Lemierre's syndrome was strongly suspected based on the patient's medical history and physical findings. Further examination revealed venous thrombus, and Fusobacterium necrophorum was later isolated from blood cultures. Antibiotics for anaerobes were administered before a final diagnosis was made, and the patient's symptoms thereafter improved. A rapid diagnosis is essential, since Lemierre's syndrome can be fatal with a diagnostic delay.

[Marked reactive plasmacytosis accompanied by drug eruption in a patient with aplastic anemia].

A 61-year-old woman with aplastic anemia was admitted to our hospital in October 2009 because of fever and abdominal pain. She had been treated with cyclosporin A without showing any effect. On admission, uterine cancer was diagnosed and the left uterine appendages were swollen. She was treated with cefepime for febrile neutropenia without effect, and left-sided adnexitis was diagnosed. After cefepime was changed to meropenem, marked plasmacytosis was observed in the peripheral blood (23%) and bone marrow (79%) with the appearance of skin eruption. Although the plasma cells were morphologically abnormal, the cytoplasmic immunoglobulin light chain deviation was not detected by flow cytometric analysis, and M protein was not found by serum immunoelectrophoresis. She was diagnosed with reactive plasmacytosis and treated with dexamethasone. The drug eruption and plasmacytosis improved soon after starting the treatment. Although reactive plasmacytosis is observed with a variety of conditions, including infection, neoplasms, autoimmune disorders, and hemolytic anemia, it has not been reported to accompany drug eruption. Reactive plasmacytosis is sometimes not possible to distinguish from plasma cell neoplasms on morphology alone and needs to be diagnosed comprehensively by using flow cytometric analysis and immunohistochemical evaluation.

Clinical impact of pre-transplant pulmonary impairment on survival after allogeneic hematopoietic stem cell transplantation.

We retrospectively analyzed the clinical outcomes of patients with pulmonary impairment before undergoing allogeneic hematopoietic stem cell transplantation (HSCT) for the first time. Among 297 evaluable patients who underwent their first HSCT, 23 had restrictive, obstructive or mixed ventilatory impairment (n = 9, 13 and 1, respectively). Males predominated among the patients with pulmonary impairment (p = 0.037) and received a reduced intensity conditioning (RIC) regimen more frequently, although the difference did not reach statistical significance (p = 0.05). Among 23 patients with pulmonary impairment, 9 underwent post-transplant pulmonary function tests and obstructive ventilatory impairment progressed only in 2 patients, both of whom developed bronchiolitis obliterans. Kaplan-Meier estimates of 3-year overall (OS) among patients with and without pulmonary impairment were 57% and 47%, respectively, and those of relapse-free survival (RFS) were 70%, and 68%, respectively, with no significant differences between the groups (OS, p = 0.235; RFS, p = 0.287). The rates of non-relapse mortality also did not significantly differ (p = 0.835). Our results suggest that allogeneic HSCT is safe for patients with pulmonary impairment. The lower frequency of fatal pulmonary complications after HSCT and the RIC regimen might contribute to favorable survival rates.

Successful treatment of cyclosporine-A-resistant cytophagic histiocytic panniculitis with tacrolimus.

A 34-year-old woman with discoid lupus erythematosus and lupus profundus was admitted to our hospital showing signs of a fever, malaise, and abdominal swelling. Diagnosis of cytophagic histiocytic panniculitis (CHP) was made based on lobular panniculitis with a hemophagocytosis. Treatment with high doses of prednisolone combined with cyclosporine A (CsA) was not effective enough. However, after changing CsA to tacrolimus (TAC), CHP improved. Our case demonstrates that TAC may be a novel therapy for CHP.

Neutron gamma ray radiography using a two-color luminescent scintillator.

Neutron and gamma ray radiographs has been obtained using red and green images on a two-color luminescent scintillator using a cooled color CCD camera at the thermal neutron radiography field of JRR-3m.