Shear-dependent platelet aggregation size

Nonsurgical bleeding is the most frequent complication of left ventricular assist device (LVAD) support. Supraphysiologic shear rates generated in LVAD causes impaired platelet aggregation, which increases the risk of bleeding. The effect of shear rate on the formation size of platelet aggregates has never been reported experimentally, although platelet aggregation size can be considered to be directly relevant to bleeding complications. Therefore, this study investigated the impact of shear rate and exposure time on the formation size of platelet aggregates, which is vital in predicting bleeding in patients with an LVAD. Human platelet-poor plasma (containing von Willebrand factor, vWF) and fluorochrome-labeled platelets were subjected to a range of shear rates (0-10 000 s⁻¹) for 0, 5, 10, and 15 minutes using a custom-built blood-shearing device. Formed sizes of platelet aggregates under a range of shear-controlled environment were visualized and measured using microscopy. The loss of high molecular weight (HMW) vWF multimers was quantified using gel electrophoresis and immunoblotting. An inhibition study was also performed to investigate the reduction in platelet aggregation size and HMW vWF multimers caused by either mechanical shear or enzymatic (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13—ADAMTS13, the von Willebrand factor protease) mechanism under low and high shear conditions (360 and 10 000 s⁻¹). We found that the average size of platelet aggregates formed under physiological shear rates of 360-3000 s⁻¹ (200-300 μm²) was significantly larger compared to those sheared at >6000 s⁻¹ (50-100 μm²). Furthermore, HMW vWF multimers were reduced with increased shear rates. The inhibition study revealed that the reduction in platelet aggregation size and HWM vWF multimers were mainly associated with ADAMTS13. In conclusion, the threshold of shear rate must not exceed >6000 s⁻¹ in order to maintain the optimal size of platelet aggregates to “plug off” the injury site and stop bleeding.     

Early-onset sarcoidosis and CARD15 mutations with constitutive nuclear factor-kappaB activation: common genetic etiology with Blau syndrome

Early-onset sarcoidosis (EOS) and inheritable Blau syndrome (BS) share characteristic clinical features of juvenile-onset systemic granulomatosis syndrome that mainly affects skin, joints, and eyes. However, no direct evidence has been shown for the possible common origin of these 2 diseases. Recent discovery of CARD15 mutations in BS families encouraged us to investigate similar CARD15 mutations in EOS patients. Among 10 EOS cases retrospectively collected in Japan, heterozygous missense mutations were found in 9 cases; 4 showed a 1000C>T (R334W in amino acid change) that has been reported in BS, 4 showed novel 1487A>T (H496L), 1538T>C (M513T), 1813A>C (T605P), and 2010C>A (N670K), and 1 case showed double 1146C>G (D382E)/1834G>A (A612T) mutations on different alleles. All 6 of these variants of CARD15 showed increased basal nuclear factor (NF)-kappaB activity. These findings indicate that the majority of EOS and BS cases share the common genetic etiology of CARD15 mutations that cause constitutive NF-kappaB activation.     

Immunological responses in acute low-tone sensorineural hearing loss and Ménière's disease

OBJECTIVE: The autoimmune response appears to play an important role in some types of acute sensorineural hearing loss. Endolymphatic hydrops associated with fluctuating hearing loss has also been suggested to be caused by an immunological mechanism. Acute low-tone hearing loss (ALHL) associated with Ménière's disease (MD) is characterized by fluctuating hearing loss, and its etiology is thought to involve endolymphatic hydrops. The aim of this study was to attempt to determine the etiology of ALHL in MD. MATERIAL AND METHODS: A flow cytometer was used to analyze intracellular cytokine levels in peripheral blood from 19 patients with ALHL and 26 patients with MD and the data compared to those obtained from age- and gender-matched healthy volunteers. RESULTS: The patients with ALHL showed significantly increased levels of Th1 subsets (interferon-gamma-producing helper T cells) as compared to those in normal controls. The levels of Th2 (IL-4-producing helper T cells) subsets did not differ from those in the control group and thus Th1 predominated in ALHL patients. The patients with MD showed significantly increased natural killer cell activity but no Th1 dominance. These patients had no obvious systemic or local disease except in the inner ear. CONCLUSION: An abnormality of the Th1/Th2 balance in ALHL and increased natural killer cell activity in MD are thought to relate to inner ear disorder. These results are consistent with the possibility that the etiology of ALHL and MD involves an immune response.     

New Approach to Eliminate HLA Class I Antigens from Platelet Surface without Cell Damage: Acid Treatment at pH 3.0

A new method was studied for eliminating HLA class I antigens from the surface of platelets without damaging the cells. Platelets were exposed to an acid solution (pH 3.0) to eliminate the antigenicity of HLA class I antigens. The reduction in antigenicities of HLA class I common antigen and individual HLA class I antigens by acid treatment was marked. Patients' sera which contained multispecific HLA antibodies reacted with PBS-treated platelets, but not with acid-treated platelets. No changes were observed in the antigenicities of glycoprotein Ib or glycoprotein IIb/IIIa. The viability of acid-treated platelets was 83%. Ultrastructural investigations revealed no significant difference between the PBS-treated platelets and acid-treated platelets. The platelet function studies showed that the aggregation of acid-treated platelets induced by various agonists was only slightly reduced compared with PBS-treated platelets. We propose that acid-treated platelets are promising for clinical use in patients refractory to platelet transfusions and may be superior to chloroquine-treated platelets for analysis of the specificity of antiplatelet antibodies.     

Comparative analysis of clinical outcomes after allogeneic bone marrow transplantation versus peripheral blood stem cell transplantation from a related donor in Japanese patients

A reduced incidence of graft versus host disease (GvHD) has been documented among Japanese allogeneic bone marrow transplantation (BMT) patients, as the Japanese are genetically more homogeneous than western populations. To clarify whether this ethnic difference affects the results of allogeneic peripheral blood stem cell transplantation (PBSCT), we conducted a nationwide survey to compare clinical outcomes of allogeneic PBSCT (n = 214) and BMT (n = 295) from a human leucocyte antigen-identical-related donor in Japanese patients. The cumulative incidence of grades II-IV acute GvHD was 37.4% for PBSCT and 32.0% for BMT. The cumulative incidence of extensive chronic GvHD at 1 year was significantly higher after PBSCT than BMT (42% vs. 27%; P < 0.01). The organ involvement patterns of GvHD were different between the two groups. By multivariate analyses, the incidence of chronic GvHD was significantly increased in PBSCT, whereas the stem cell source did not affect the incidence of acute GvHD, transplant-related mortality, relapse or survival. We concluded that Japanese PBSCT patients have an increased risk of chronic GvHD compared with BMT patients, but the incidence of acute GvHD was still lower than in western populations. Thus, the choice of haematopoietic stem cell source should be considered based on data for individual ethnic populations.     

Long‐term persistent fetomaternal hemorrhage

It is not clear that how long the affected fetuses can tolerate fetomaternal hemorrhage (FMH). Incidental serial measurements of the fetal peak systolic velocity of the middle cerebral artery and the retrospective analysis of stocked blood available incidentally indicated that our patient had suffered from FMH for at least 2 weeks prior to delivery.     

Impact of reflux esophagitis on the esophageal function before and after laparoscopic fundoplication

Background

High-resolution manometry (HRM), which is breakthrough testing equipment to evaluate esophageal motor function, was developed in Europe and United State and has garnered attention. Moreover, multichannel intraluminal impedance pH (MII-pH) testing has allowed us to grasp all liquid/gas reflux including not only acid but also non-acid reflux. We examined the impact of the presence of reflux esophagitis (RE) on esophageal motor function before and after laparoscopic fundoplication.

Materials and methods

The subjects included 100 patients (male: 63 patients, mean age: 54.1?±?15.8) among 145 patients who underwent laparoscopic fundoplication for GERD associated diseases during a 4-year period from October 2012 to September 2016, excluding 6 patients who underwent further surgery, 32 patients on whom HRM was not performed, 3 patients who had technical errors during testing, and 4 patients for whom the status of RE was unknown. Regarding HRM, Mano Scan from Given Imaging Ltd. was used, and for the analysis, Mano View version 3.0 from the same company was used, after which data was calculated based on the Chicago Classification advocated by Pandolfino et al. Moreover, for the MII-pH testing, Sleuth manufactured by Sandhill Scientific. Inc. was used and automatic analysis was conducted by a computer. Postoperative assessments were conducted 3 months following surgery for all. Data was described in the median value and inter-quartile range, with a statistically significant difference defined as p?<?0.05 by Chi square, Mann–Whitney, and Wilcoxon tests.

Results

RE+?group (Los Angeles classification A:B:C:D?=?7:9:16:12 patients) included 44 patients (44%), of older age compared to the RE? group (62 vs. 50 years, p?=?0.012) and a higher Body Mass Index value (24.0 vs. 22.5, p?=?0.045); however, no differences were observed in terms of gender and duration of symptoms. In the preoperative findings on MII-pH, the RE+?group demonstrated significantly longer acid reflux time (4.7 vs. 1.3%, p?=?0.005), while in the HRM findings, the RE? group demonstrated a significantly longer abdominal esophagus (0 vs. 0.4 cm, p?=?0.049) and maintained esophageal body motor function (DCI: 1054 vs. 1407 mmHg s cm, p?=?0.021, Intact peristalsis ratio: 90 vs. 100%, p?=?0.037). As to the comparison of the treatment effect before and after laparoscopic fundoplication (Toupet fundoplication for all), significant improvements were observed in both groups in various parameters regarding reflux including acid reflux time, total number of liquid reflux episodes and total number of reflux episodes. Moreover, for both groups, the total length of the lower esophageal sphincter (LES) (RE+?group: 2.7 vs. 3.2 cm, p?=?0.001, RE? group: 3.0 vs. 3.4 cm, p?=?0.003) and the total length of the abdominal esophagus (RE+?group: 0 vs. 1.6 cm, p?<?0.001, RE? group: 0 vs. 1.8 cm, p?=?0.001) were significantly extended following surgery; however, no change was observed in DCI before and after surgery.

Conclusions

Regardless of the presence of RE, cardiac function and LES function were improved following laparoscopic Toupet fundoplication, but no changes were observed in esophageal body motor function.