The Long Elusive IgM Fc Receptor,FcμR

IgM exists as both a monomer on the surface of B cells and a pentamer secreted by plasma cells. Both pre-immune “natural” and antigen-induced “immune” IgM antibodies are important for protective immunity and for immune regulation of autoimmune processes by recognizing pathogens and self-antigens. Effector proteins interacting with the Fc portion of IgM, such as complement and complement receptors, have thus far been proposed but fail to fully account for the IgM-mediated protection and regulation. A major reason for this deficit in our understanding of IgM function seems to be lack of data on a long elusive Fc receptor for IgM (FcμR). We have recently identified a bona fide FcμR in both humans and mice. In this article we briefly review what we have learned so far about FcμR.     

A novel method to estimate changes in stress-induced salivary α-amylase using heart rate variability and respiratory rate,as measured in a non-contact manner using a single radar attached to the back of a chair

The authors have developed a non-contact system which estimates changes in salivary α-amylase (sAA ratio) induced by stress. Before and after stressful sound exposure, a single 24?GHz compact radar which is attached to the back of a chair measures the low frequency (LF) component of heart rate variability and respiratory rate, α-amylase in the subjects’ buccal secretions was measured by using an α-amylase assay kit. Using multiple regression analysis, sAA ratio was estimated using stress-induced LF change (LF ratio) and stress-induced respiratory rate change (respiratory rate ratio). Twelve healthy subjects were tested (12 males, 22?±?2 years), who were exposed to audio stimuli with a composite tone of 2120?Hz and 2130?Hz sine waves at a sound pressure level of 95?dB after a silent period through a headphone. The result showed that sAA ratio estimated using multiple regression analysis significantly correlated with measured sAA ratio (R?=?0.76, p?相似文献   

Intraductal dissemination of papillary adenocarcinoma of the ampulla of Vater in the pancreatic duct

It has been speculated that intraductal dissemination, via the pancreatic duct, bile duct, or mammary duct, is a unique form of cancer cell spread. However, clinical evidence to confirm this form of dissemination has been lacking. Here we report a case of papillary adenocarcinoma of the ampulla of Vater in which retrograde dissemination to the pancreatic duct was strongly suggested. A 79‐year‐old woman underwent pancreatoduodenectomy for a 22 mm microinvasive papillary adenocarcinoma of the ampulla. Multiple carcinomas in situ were found in the pancreatic duct distant from the ampulla. Seven months later, she underwent a second operation for a recurrent papillary adenocarcinoma at the pancreato‐jejunal anastomosis showing exophytic and expansive growth into the jejunal lumen that connected to an intraductal adenocarcinoma in the pancreatic body. None of these tumors showed invasive growth, or vascular or neural invasion, being separate from each other but sharing identical histological, immunohistochemical, and molecular features; papillary growth, a pancreatobiliary phenotype, the same pattern of genomic loss of heterozygosity, and no mutation of the KRAS, TP53, and GNAS genes. These results imply that this papillary adenocarcinoma of the ampulla of Vater had disseminated to the pancreatic duct in a retrograde manner and recurred in the remnant pancreas.     

The behavior of ligament cells cultured on elastin and collagen scaffolds

The ruptured anterior cruciate ligament (ACL) does not heal spontaneously. Therefore, the development of new healing techniques employing tissue engineering is vital. One of the aspects related to tissue-engineered artificial ligaments is the type of cell to be used for the artificial ligament. In this study, ligament cells from the ACL and periodontal ligament (PDL) were evaluated. In addition, we prepared highly oriented extracellular matrix (ECM) fiber scaffolds that mimicked the structure of the ligament and examined the cellular responses to these scaffolds. Elastin-A and collagen were used as the ECM proteins. Although the cells from the PDL (PDL fibroblasts [PDLFs]) showed approximately 2.1-fold higher expression of alkaline phosphatase (ALP; marker of osteogenic differentiation) than the ACL cells, the expression of ligament-related genes (for type I collagen, type III collagen, and tenomodulin) did not differ between PDLFs and ACL cells. Furthermore, the cellular responses (expression pattern of ligament-related genes and ALP activity) to the ECM were similar between ACL cells and PDLFs. In particular, elastin-A upregulated ALP and downregulated tenomodulin (TeM; a ligament marker) in ligament cells. In contrast, collagen maintained TeM expression in ligament cells. These results suggest that elastin-A promotes the osteogenic differentiation of ligament cells and that collagen maintains the phenotype of ligament cells.     

Electromagnetic interference of implantable cardiac devices from a shoulder massage machine

Shoulder massage machines have two pads that are driven by solenoid coils to perform a per cussive massage on the shoulders. There have been concerns that such machines might create electromagnetic interference (EMI) in implantable cardiac devices because of the time-varying magnetic fields produced by the alternating current in the solenoid coils. The objective of this study was to investigate the potential EMI from one such shoulder massage machine on implantable cardiac devices. We measured the distribution profile of the magnetic field intensity around the massage machine. Furthermore, we performed an inhibition test and an asynchronous test on an implantable cardiac pacemaker using the standardized Irnich human body model. We examined the events on an implantable cardioverter–defibrillator (ICD) using a pacemaker programmer while the massage machine was in operation. The magnetic field distribution profile exhibited a peak intensity of 212 (A/m) in one of the solenoid coils. The maximal interference distance between the massage machine and the implantable cardiac pacemaker was 28 cm. Ventricular fibrillation was induced when the massage machine was brought near the electrode of the ICD and touched the Irnich human body model. It is necessary to provide a “don’t use” warning on the box or the exterior of the massage machines or in the user manuals and to caution patients with implanted pacemakers about the dangers and appropriate usage of massage machines.     

Selective expansion of donor‐derived regulatory T cells after allogeneic bone marrow transplantation in a patient with IPEX syndrome

IPEX syndrome is a rare and fatal disorder caused by absence of regulatory T cells (Tregs) due to congenital mutations in the Forkhead box protein 3 gene. Here, we report a patient with IPEX syndrome treated with RIC followed by allogeneic BMT from an HLA‐matched sibling donor. We could achieve engraftment and regimen‐related toxicity was well tolerated. Although the patient was in mixed chimera and the ratio of donor cells in whole peripheral blood remained relatively low, selective and sustained expansion of Tregs determined as CD4+CD25+Foxp3+ cells was observed. Improvement in clinical symptoms was correlated with expansion of donor‐derived Tregs and disappearance of anti‐villin autoantibody, which was involved in the pathogenesis of gastrointestinal symptoms in IPEX syndrome. This clinical observation suggests that donor‐derived Tregs have selective growth advantage in patients with IPEX syndrome even in mixed chimera after allogeneic BMT and contribute to the control of clinical symptoms caused by the defect of Tregs.     

Assessment of Interleukin‐6 Receptor Inhibition Therapy on Periodontal Condition in Patients With Rheumatoid Arthritis and Chronic Periodontitis

Background: Overproduction of interleukin (IL)‐6 may play a pathologic role in rheumatoid arthritis (RA) and chronic periodontitis (CP). The present study assesses IL‐6 receptor (IL‐6R) inhibition therapy on the periodontal condition of patients with RA and CP. Methods: The study participants were 28 patients with RA and CP during treatment with IL‐6R inhibitor, and 27 patients with RA and CP during treatment without IL‐6R inhibitor. Periodontal and rheumatologic parameters and serum levels of cytokine and inflammatory markers and immunoglobulin G against periodontopathic bacteria were examined after medication with IL‐6R inhibitor for 20.3 months on average (T1) and again 8 weeks later (T2). Results: No differences were observed between the groups in any parameter values at T1, except for serum IL‐6 levels. The anti–IL‐6R group showed a significantly greater decrease in gingival index, bleeding on probing (BOP), probing depth (PD), clinical attachment level (CAL), and serum levels of IL‐6 and matrix metalloproteinase (MMP)‐3 from T1 to T2 than the control group (P <0.05). A significant correlation was found between changes in serum anticyclic citrullinated peptide levels and those in PD and CAL in the anti–IL‐6R group (P <0.05), whereas both groups exhibited a significant association between changes in serum MMP‐3 levels and those in BOP (P <0.05). Conclusion: Changes in periodontal and serum parameter values were different between the patients with RA and CP during treatment with and without IL‐6R inhibitor.     

Effects of the Implant Design on Peri‐Implant Bone Stress and Abutment Micromovement: Three‐Dimensional Finite Element Analysis of Original Computer‐Aided Design Models

Background: Occlusal overloading causes peri‐implant bone resorption. Previous studies examined stress distribution in alveolar bone around commercial implants using three‐dimensional (3D) finite element analysis. However, the commercial implants contained some different designs. The purpose of this study is to reveal the effect of the target design on peri‐implant bone stress and abutment micromovement. Methods: Six 3D implant models were created for different implant–abutment joints: 1) internal joint model (IM); 2) external joint model (EM); 3) straight abutment (SA) shape; 4) tapered abutment (TA) shapes; 5) platform switching (PS) in the IM; and 6) modified TA neck design (reverse conical neck [RN]). A static load of 100 N was applied to the basal ridge surface of the abutment at a 45‐degree oblique angle to the long axis of the implant. Both stress distribution in peri‐implant bone and abutment micromovement in the SA and TA models were analyzed. Results: Compressive stress concentrated on labial cortical bone and tensile stress on the palatal side in the EM and on the labial side in the IM. There was no difference in maximum principal stress distribution for SA and TA models. Tensile stress concentration was not apparent on labial cortical bone in the PS model (versus IM). Maximum principal stress concentrated more on peri‐implant bone in the RN than in the TA model. The TA model exhibited less abutment micromovement than the SA model. Conclusion: This study reveals the effects of the design of specific components on peri‐implant bone stress and abutment displacement after implant‐supported single restoration in the anterior maxilla.