Audit of severe acute morbidity in hypertensive pregnancies in a developing country.

The aim of this study was to establish a population-based incidence of severe acute maternal morbidity (SAMM) in hypertensive pregnancies and to assess if substandard care was unique to cases of SAMM and mortality or whether it was apparent in uncomplicated pregnancies as well. The population-based incidence of hypertension was 12%. Using defined criteria for SAMM, the incidence of SAMM was 3/1000 deliveries. The MMR was 42/100000 deliveries, i.e. SAMM is seven times greater than the mortality. Substandard care was similar in cases of SAMM and mortality and uncomplicated hypertensive patients. Audit of SAMM is informative, can be conducted more frequently, and in small sample population groups. It also allows interviews of patients, hence problems of inefficient documentation is obviated.     

Identification of Human Sperm Antigen Recognized by Serum of an Immunoinfertile Woman: A Candidate for Immunocontraception

PROBLEM: It has been well documented that antisperm antibodies can be causative factors of infertility. In this study we have identified an antigen on human sperm surface using serum of an immunoinfertile woman; it is thus a candidate for immunocontraception. METHOD: Thirty-three women of reproductive age who were infertile were screened for presence of antisperm antibodies by indirect immunofluorescence and agglutination assay. The serum of one such woman, SU-4, reacted with her husband's as well as normal donor sperm and recognized a band of apparent molecular weight of 71-kDa on Western blot. Anti-71 -kDa antiserum was raised in rabbit by eluting 71 -kDa protein and was characterized by agglutination test, immunofluorescence assay, transmission electron microscopy, flow cytometry, and sperm-egg interaction in mouse system. RESULTS: Interestingly, sera raised in rabbit against 71-kDa antigen, was identified by immunoinfertile serum of SU-4, revealed similar results of localization of human acrosome. Anti-71-kDa antibodies showed cross-reactivity with other species of sperm, demonstrated inhibition of sperm attachment to oocytes in an in vitro mouse system, and revealed surface binding of human live sperm by flow cytometry. Transmission electron microscopy documented the presence of 71-kDa antigen in the acrosomal compartment. CONCLUSION: This study has put in evidence an antigen of apparent molecular weight of 71-kDa in all donor sperm tested in this study. The presence of this antigen on the sperm of several species will enable us to determine the efficacy of this antigen in controlling fertility in vivo in both rodents and primates. This antigen may be a candidate for immunocontraception.     

Allogeneic Transplantation for Relapsed Waldenström Macroglobulinemia and Lymphoplasmacytic Lymphoma

Waldenström macroglobulinemia/lymphoplasmacytic lymphoma (WM/LPL) is characterized by lymphoplasmacytic proliferation, lymph node and spleen enlargement, bone marrow involvement, and IgM production. Treatment varies based on the extent and biology of disease. In some patients, the use of allogeneic hematopoietic cell transplantation (alloHCT) may have curative potential. We evaluated long-term outcomes of 144 patients who received adult alloHCT for WM/LPL. Data were obtained from the Center for International Blood and Marrow Transplant Research database (2001 to 2013). Patients received myeloablative(n?=?67) or reduced-intensity conditioning (RIC; n?=?67). Median age at alloHCT was 53 years, and median time from diagnosis to transplantation was 41 months. Thirteen percent (n?=?18) failed prior autologous HCT. About half (n?=?82, 57%) had chemosensitive disease at the time of transplantation, whereas 22% had progressive disease. Rates of progression-free survival, overall survival, relapse, and nonrelapse mortality at 5 years were 46%, 52%, 24%, and 30%, respectively. Patients with chemosensitive disease and better pretransplant disease status experienced significantly superior overall survival. There were no significant differences in progression-free survival based on conditioning (myeloablative, 50%, versus RIC, 41%) or graft source. Conditioning intensity did not impact treatment-related mortality or relapse. The most common causes of death were primary disease and graft-versus-host disease (GVHD). AlloHCT yielded durable survival in select patients with WM/LPL. Strategies to reduce mortality from GVHD and post-transplant relapse are necessary to improve this approach.     

CD8 T-cell recognition of acquired alloantigen promotes acute allograft rejection

Adaptive CD8 T-cell immunity is the principal arm of the cellular alloimmune response, but its development requires help. This can be provided by CD4 T cells that recognize alloantigen “indirectly,” as self-restricted allopeptide, but this process remains unexplained, because the target epitopes for CD4 and CD8 T-cell recognition are “unlinked” on different cells (recipient and donor antigen presenting cells (APCs), respectively). Here, we test the hypothesis that the presentation of intact and processed MHC class I alloantigen by recipient dendritic cells (DCs) (the “semidirect” pathway) allows linked help to be delivered by indirect-pathway CD4 T cells for generating destructive cytotoxic CD8 T-cell alloresponses. We show that CD8 T-cell–mediated rejection of murine heart allografts that lack hematopoietic APCs requires host secondary lymphoid tissue (SLT). SLT is necessary because within it, recipient dendritic cells can acquire MHC from graft parenchymal cells and simultaneously present it as intact protein to alloreactive CD8 T cells and as processed peptide alloantigen for recognition by indirect-pathway CD4 T cells. This enables delivery of essential help for generating cytotoxic CD8 T-cell responses that cause rapid allograft rejection. In demonstrating the functional relevance of the semidirect pathway to transplant rejection, our findings provide a solution to a long-standing conundrum as to why SLT is required for CD8 T-cell allorecognition of graft parenchymal cells and suggest a mechanism by which indirect-pathway CD4 T cells provide help for generating effector cytotoxic CD8 T-cell alloresponses at late time points after transplantation.Cytotoxic CD8 T-cell responses directed against MHC class I alloantigens are one of the principal mediators of acute allograft rejection (1, 2). Exceptionally, at very high precursor frequency, cytotoxic CD8 T cells can effect graft rejection autonomously (3), but generally, differentiation of naïve CD8 T cells to fully functional cytotoxic effector cells capable of mediating acute allograft rejection requires help from activated CD4 T cells. How such help is delivered remains unclear. Studies of conventional CD8 T-cell responses against nontransplant antigens have demonstrated that CD4 T-cell help does not involve cognate cell-surface interaction between the helper CD4 T cell and cytotoxic CD8 T cell, but that instead, help is delivered to an intermediary antigen presenting cell (APC), which is then licensed to prime CD8 T cells (4–6). A critical requirement for such help is the expression of both the CD4 and CD8 T-cell epitopes on the same APC, and an analogous three-cell cluster model (Fig. 1A) in transplantation is only possible if help for CD8 T cells is provided by CD4 T cells that recognize intact MHC class II alloantigen on the surface of donor APCs, via the so-called “direct pathway” (7). Murine studies have confirmed that restricting CD4 T-cell help to the direct pathway generates strong cytotoxic CD8 T-cell alloresponses that effect rapid allograft rejection (8).Open in a separate windowFig. 1.Possible mechanisms for provision of CD4 T-cell help to alloreactive CD8 T cells. Analogous to provision of CD4 T-cell help for cytotoxic CD8 T-cell responses against nominal protein antigen, simultaneous linked direct-pathway allorecognition of MHC class I and class II alloantigen on donor antigen presenting cells (APCs) by cytotoxic CD8 and helper CD4 T cells, respectively, is considered the dominant helper mechanism (A). Nevertheless, indirect-pathway CD4 T cells that recognize self-restricted alloantigen following internalization and processing by recipient APCs can also provide help; an unlinked four-cell cluster model has been proposed (B). Provision of linked help by indirect pathway CD4 T cells may be achieved by a three-cell cluster model in which the recipient APC simultaneously presents intact and processed MHC class I alloantigen to, respectively, the cytotoxic CD8 T-cell and helper CD4 T-cell (C).The indirect pathway of allorecognition, whereby CD4 T cells recognize processed alloantigen as self-restricted allopeptide (7, 9), is now viewed as being at least as important as the direct pathway for initiating and mediating allograft rejection. This importance partly reflects the unique ability of indirect-pathway CD4 T cells to act as helper T cells for generating sophisticated alloantibody responses (10), but it is now also clear that effective cytotoxic CD8 T-cell responses can be generated when CD4 T-cell help is restricted exclusively to the indirect pathway (11). This observation is surprising, because the delivery of indirect-pathway T-cell help is only readily explained by postulating the unlikely formation of a cumbersome four-cell cluster, comprising CD4 and CD8 T lymphocytes and both recipient and donor APC (Fig. 1B), a cluster in which there are no apparent cell surface ligands to enable physical linkage between the donor APC/recipient CD8 T-cell couplet and the recipient APC/CD4 T-cell couplet. This scenario raises concerns of potentially uncontrolled CD8 T-cell alloimmunity, because such “unlinked” help could in principle be provided by concurrent exposure to any unrelated antigen.The appreciation that many types of cells, but particularly dendritic cells (DCs), can capture (“trogocytose”) membrane fragments from other cells (12, 13) has prompted the proposal that cytotoxic CD8 T-cell alloimmunity may be initiated by a “semidirect” pathway, whereby intact donor MHC class I alloantigen is recognized after its acquisition onto the surface of recipient DCs. In support, murine studies have detailed in vivo capture of membrane alloantigen by host cells (14, 15). This phenomenon provides a possible mechanism by which the same recipient APC as represents intact MHC class I alloantigen could simultaneously present processed allopeptide for recognition by indirect-pathway CD4 T cells. This scenario would enable formation of a linked three-cell cluster (Fig. 1C) that obviates many of the concerns associated with the above four-cell cluster model. However, although we have recently demonstrated simultaneous presentation of intact and processed alloantigen by recipient DCs following heart transplantation (16), the contribution of trogocytosis of alloantigen to graft rejection has yet to be clarified. To have functional relevance, presentation of intact donor alloantigen by recipient APCs must, at least in certain circumstances, be more effective for triggering cytotoxic alloimmunity than conventional encounter on donor APCs, and this has not been shown. Addressing this key concern is challenging, because it requires development of an experimental model in which CD8 T-cell allorecognition of target MHC class I alloantigen is limited to the surface of recipient, but not donor APCs. One way this scenario could perhaps be achieved is by resolving the paradox created by the seminal observations that CD8 T cells can still effect allograft rejection when target MHC class I alloantigen is expressed by graft parenchyma only (17), but that rejection of vascularized allografts does not occur in the absence of secondary lymphoid tissue (SLT) (18). Why SLT is necessary for CD8 T-cell allorecognition of graft parenchymal cells has not been explained, but one elegant and compelling solution is that alloreactive CD8 T-cell activation occurs in lymphoid tissue because shed, intact MHC class I alloantigen is only presented by recipient APCs at these sites.Here, we show that rejection of heart allografts in mice lacking hematopoietic APCs is mediated by alloreactive CD8 T cells, and that the participation of CD8 T-cells is dependent upon the acquisition and presentation of intact MHC class I alloantigen by recipient DCs within host SLT. We further demonstrate that representation of intact alloantigen enables the delivery of essential help from indirect-pathway CD4 T cells. These findings provide strong functional support for the provision of indirect-pathway CD4 T-cell help to alloreactive CD8 T cells via a “linked” three-cell cluster model.     

Emergency Department Patient Burden from an Electronic Dance Music Festival

Background

Electronic dance music (EDM) festivals are increasingly common and psychoactive substance use is prevalent. Although prehospital care can obviate the transfer of many attendees to health care facilities (HCFs), little is known regarding the emergency department (ED) burden of patients presenting from EDM festivals.

The sensitivity and specificity of a red blood cell agglutination D-dimer assay for venous thromboembolism when performed on venous blood.

BACKGROUND: Studies evaluating the accuracy of the SimpliRED D-dimer assay for venous thromboembolism (VTE) have used a capillary fingerstick blood sample, which requires the test to be performed immediately at the bedside. Initial studies showed a sensitivity for VTE of 90% to 95% when the assay was performed by a finite number of experienced health care workers. However, because of the test's subjectivity, misinterpretation of the result is possible when performed by inexperienced staff. Recent reports by other investigators indicated a low sensitivity of this assay for VTE and noted a reduction in sensitivity (84%) for pulmonary embolism. OBJECTIVE: To determine the sensitivity and specificity of the D-dimer test performed in the laboratory by experienced technologists on venous whole-blood samples in routine collection tubes. If D-dimer testing results accurately detect VTE when performed in this manner, concerns about the sensitivity of this assay would be solved. METHODS: One hundred forty-eight consecutive patients with suspected VTE underwent D-dimer testing at the bedside using a fingerstick sample and venous blood collected into a plain tube. Venous blood was also collected into tubes containing tri-potassium EDTA, sodium citrate, or a combination of lithium and heparin for D-dimer testing in the laboratory. In addition, the EDTA tube was refrigerated overnight at 4 degrees C for retesting at approximately 24 hours. The presence or absence of VTE was determined by means of objective results of testing and a 3-month follow-up. RESULTS: Thirty-four subjects (23%) had confirmed VTE (25 with deep vein thrombosis; 9 with pulmonary embolism). All laboratory venous blood D-dimer results showed sensitivities of 97%, specificities of 61% to 64%, and negative predictive values of 99%, compared with 88%, 71%, and 95%, respectively, when the results were obtained by means of fingerstick at the bedside. CONCLUSIONS: The SimpliRED D-dimer assay performed in the laboratory on venous blood, collected into any of 3 routine laboratory tubes, is sensitive and moderately specific for VTE. Based on this study, immediate bedside testing (particularly by inexperienced personnel) under suboptimal conditions is unnecessary. Furthermore, the high sensitivity of refrigerated EDTA samples allows specimens to be stored or transported (on ice at 4 degrees C) for testing for 24 hours after collection.     

Management of severe bupropion poisoning with intravenous lipid emulsion

Background: Bupropion toxicity is characterized by central nervous system and cardiovascular toxicity. Intravenous lipid emulsion (ILE) has been suggested as a treatment by some for the treatment of refractory bupropion toxicity. This recommendation is based largely on published case reports and cases presented at scientific meetings. The objective of this study is to characterize the outcomes of patients with suspected bupropion toxicity in which ILE was administered and the indications for its use.

Methods: Electronic records from one regional poison center were searched for intentional bupropion ingestions from 1 January 2009 through 31 December 2015. Cases in which ILE was administered or death was listed as the outcome were further analyzed.

Results: There were 1274 cases of suspected bupropion ingestion reported during the study period with 14 reported deaths. Nine cases of ILE administration were identified. Of these, four patients expired and five survived. One of the survivors had neurologic sequelae necessitating placement in a long-term care facility. Patient complications after ILE administration were common and included continued hypotension in 7 cases, recurrent seizures in 3 patients, ARDS in two patients, and renal failure in one patient.

Conclusions: The high mortality and complication rate after ILE in this study sample does not reflect the positive outcome benefit seen in previous published case reports. Further characterization of the efficacy and complications of ILE in bupropion toxicity is needed.     

Synthesis and spectroscopic studies of functionalized graphene quantum dots with diverse fluorescence characteristics

In this research, we report a facile method for synthesizing a series of carboxyl functionalized graphene quantum dots (GQDs) using graphite flakes (300 meshes) as raw material. These highly luminescent GQDs emitted blue, light blue, green, yellow, and red light (400–700 nm intensity peaks) under ultraviolet irradiation conditions, while exhibiting quantum yields in the range of 50–70%. The products were comprehensively characterized using ultraviolet-visible, photoluminescence, infrared, Raman, and dynamic light scattering spectroscopies. The GQDs were found to remain highly stable against photobleaching when stored over a prolonged period of more than three months. The proposed method for the synthesis of high quality, multicolor GQDs can be utilized to extend the application of these nanoparticles to molecular biotechnology and bioengineering; for example, the immobilization of cancer markers on their surface. As such, carboxylic acid groups present on the surface of these GQDs help create complexes for in vivo sensing applications.

In this research, we report a facile method for synthesizing a series of carboxyl functionalized graphene quantum dots (GQDs) using graphite flakes (300 meshes) as raw material.