bluuebunny/crossref_metadata_2025 huggingface dataset:
Peptide Vaccine Preparation and Validation with a Bio-Assay
Authors: Schmitt Anita , Bechter Clemens , Yao Junxia , Goetz Marlies , Maccari Birgit , Schauwecker Peter , Wiesneth Markus , Schmitt Michael
Published: April 2020

Introduction: Peptide vaccination constitutes a novel immunotherapeutical approach for the treatment of patients with solid tumors, lymphoma and leukemia. Moreover it might be of use in hematooncological patients for the prevention and therapy of infections like cytomegalovirus (CMV) reactivation due to immunosuppression. To meet good manufacturing practice (GMP) criteria, we introduce here a bio-assay to validate peptide vaccines for peptide content and bio-activity.

Methods: As a paradigm for peptide vaccine preparation the immunogenic CMV peptide (pp65, pos.: 495–503 NLVPMVATV) lyophilisate was resolubilized in dimethyl sulfoxide (DMSO), phosphate buffered saline (PBS) and admixed with Montanide™ (ISA51: incomplete Freund’s adjuvant [IFA]). This mixture freshly prepared, stored at +4°C and cryopreserved at −20°C was subjected to lymphocyte peptide cultures (MLPC) followed by enzyme linked immunospot (ELISPOT) assays and flow cytometry (FACS) as bio-assay.

Results: Addition of different amounts of peptide (10–80 μg) to a MLPC resulted in the generation of interferon (IFN) gamma and granzyme B releasing CD8+ CMV tetramer+ T cells in a dose dependent manner. The combination of FACS and ELISPOT results allowed the definition of the peptide amount in a vaccine preparation. Storage at ±4°C over 24 hrs did not result in a significant change of the immunogenicity of the vaccine, as assessed by ELISPOT and FACS. In contrast, cryopreservation of the vaccine at −20°C resulted in a loss of immunogenicity.

Conclusion: Quantitation of tumor/viral antigen peptides admixed with adjuvants, such as IFA, is feasible through bio-assays as the modified ELISPOT/FACS assay described here, meeting GMP criteria for multi-center trials.
Endothelial Progenitor Cell Marker CD133 Identifies Tumor Endothelium
Authors: Baljevic Muhamed , Shmelkov Sergey V , Nolan Daniel J , Hooper Andrea T , Hormigo Adilia , Iyer Rajiv , Gutin Philip H , Rafii Shahin
Published: April 2020

CD133, a pentaspan surface antigen, is considered a marker of tissue-specific stem cells, including hematopoietic stem cells and endothelial progenitors. We and others have previously shown that CD133 expression is high on endothelial progenitor cells; that it is downregulated during their differentiation and that it is not found on mature endothelium. In addition, CD133+ cells in brain tumors were shown to exhibit features of cancer stem cells. Recent report showed that CD133+ tumor cells are located in perivascular niches in astrocytomas and glioblastomas. It was also demonstrated that in glioblastomas, CD133+ cancer stem cells are tightly associated with tumor vasculature and that signals from endothelial cells are the key factors in self-renewal and proliferation of cancer stem cells. However, the contribution of CD133+ endothelial progenitor cells to tumor angiogenesis remains unknown. We sought to investigate the role of CD133+ cells in human brain tumors and their relation to endothelial progenitor cells and to the mature endothelium. To this end we examined tumor samples resected from patients with glioblastomas. Histological and immunohistochemical analyses revealed that CD133+ cells in these tumors are predominantly endothelial cells as demonstrated by co-staining with CD31 and CD133. We further analyzed a population of endothelial cells using multicolor flow cytometry analysis and we demonstrated that on average 60% of endothelial cells, as defined by the expression of CD31 and VE-cadherin, also express CD133. However, we also found significant heterogeneity between glioblastomas obtained from different patients. Additionally, CD133 was not expressed on CD45−CD31+ subpopulation in meningiomas. Taken together, we demonstrated that high percentage of endothelial cells in glioblastomas expresses CD133, while CD133 could also be found on other cell types within the tumor. Furthermore, our data suggest that tumor vasculature might be enriched with bone marrow derived hemangiogenic progenitors.
Human Bone Marrow Mononuclear Cells, CD34+ Cells and CD133+ Cells Do Not Form Vascular Structures in Vivo
Authors: Josefsen Dag , Kuchler Axel , Wang Mengyu , Haraldsen Guttorm , Kvalheim Gunnar
Published: April 2020

The clinical results of using bone marrow-derived progenitor cells to repair ischemic tissue in coronary disease are controversial since some studies demonstrate improvement of cardiac function, whereas others do not. In these studies both unmanipulated mononuclear bone marrow cells (MNC) and highly enriched stem cells such as CD34+, CD133+ or mesenchymal cells (MSC) were used. In this study we have examined the in vitro and in vivo endothelial progenitor properties of these populations. MNC were obtained from whole BM. CD34+ cells and CD133+ cells were isolated using magnetic bead technology (MACS, Miltenyi). MSC was established from BM, and only second passages from MSC were used. Cytokine profiles of MSC were measured on a Bio-Plex system (BIO-RAD Laboratories). In vitro studies were performed by culturing cells in either complete EGM-2 medium to identify EPC, or in M199 with endothelial growth factors to investigate endothelial differentiation. We observed little or no endothelial differentiation when culturing CD133+ or CD34+ cells in M199 media. Furthermore, we did not observe EPC colony formation of MNC, CD133+ cells, or CD34+ cells cultured in EGM-2 medium. To study the in vivo effect of MNC, CD34+, CD133+ as well as MSC, we adoptively transferred human cells into immunodeficient mice and examined their endothelial potential assessing the formation of blood vessels as readout (Skovseth et al Am J of Pathol 2002, Blood 2005). Human umbilical cord-derived endothelial cells (HUVEC) served as positive controls. MNC only grew as round shaped clustered cells with no signs of vessel formation. Neither CD34+ cells nor CD133+ cells demonstrated signs of endothelial development in vivo. MSCs were found to ex vivo secrete endothelial growth factors, including VEGF, bFGF and EGF. When Matrigel plugs with MSCs were examined, an accumulation of smooth muscle actin-positive cells could be detected, but no vessel like endothelial structures derived from human cells could be found. If these putative smooth muscle cells are differentiated from the MSCs, or are murine host cells attracted to the human MSCs due to the cytokine secretion effects of the MSCs is not clear. Currently, we are exploring if co-cultivation of MSC in combination with MNC, CD133+ cells or CD34+ cells will facilitate endothelial development. In conclusion, our experiments did not show endothelial cell differentiation or vessel formation from human BM-MNC, CD34+ cells or CD133+ cells suggesting that such cells have a limited vasculogenic effect. Our findings with the MSCs are interesting and the mechanism of actions is under further investigation.
Increased Bone Marrow Microvascular Density in Hematologic Malignancies
Authors: Negaard Helene Francisca Stigter , Iversen Nina , Bowitz-Lothe Inger Marie , Sandset Per Morten , Steinsvik Brit , Østenstad Bjørn , Iversen Per Ole
Published: April 2020

Background: Angiogenesis is a potential target for therapy, both in solid tumors and in hematologic malignancies. However, the regulation of angiogenesis is complex, different cancers are inherently heterogeneous, and these drugs target different angiogenic regulators. Therefore, a detailed characterization of angiogenesis in individual cancers is needed.

Materials and methods: The study cohort consisted of 93 consecutive patients with hematologic neoplasia; i.e. acute myeloid leukemia (n=20), chronic lymphatic leukemia (n=14), multiple myeloma (n=11), and non-Hodgkin’s lymphoma (NHL, n=48). We determined the microvessel density (MVD) in bone marrow biopsy specimens by immunohistochemical staining for CD34. In addition, we measured the plasma concentrations of eight putative angiogenesis regulators using Luminex multiplex assay, and the expression in peripheral blood mononuclear cells (PBMNC) of 40 angiogenesisrelated mRNAs using quantitative RT-PCR.

Results: Untreated patients had increased bone marrow MVD (mean 39 microvessels/mm2) compared to healthy subjects (mean 20 microvessels/mm2; p<0.001). In particular, patients with advanced stage disease had increased bone marrow MVD (mean 45 microvessels/mm2) compared to patients with lower stage disease (mean 35 microvessels/mm2, p=0.030). A novel finding was that patients with NHL also had significantly increased bone marrow MVD (mean 38 microvessels/mm2). The patients had increased plasma levels of vascular endothelial growth factor (VEGF; mean 31 vs 19 pg/ml, p<0.001), interleukin (IL)-6 (median 4.6 vs 2.3 pg/ml, p=0.034) and IL-8 (median 7.2 vs 3.9 pg/ml, p=0.001). Plasma levels of fibroblast growth factor 2 (FGF2), tumor necrosis factor α, and angiogenin were not significantly different in patients compared to controls. Pre-treatment plasma levels of VEGF and FGF2 were significantly higher in those who did not achieve complete remission after cancer therapy. Patients with advanced stage disease had significantly higher plasma levels of IL-6 and -8. The mRNA most highly expressed in PBMNC was IL8, which was 15-fold up-regulated. The mRNA expression of VEGFA in PBMNC was strongly correlated to the expressions of hypoxia-inducible factors 1α and 2α (r=0.7 and p<0.001 for both). There were no differences in bone marrow MVD when comparing the different diagnoses. However, the majority of the putative regulators of angiogenesis studied were significantly different between the diagnoses; indicating that bone marrow MVD in hematologic malignancies was differentially regulated.

Conclusions: Our data show that patients with hematologic malignancies have increased bone marrow MVD, supporting the notion that bone marrow angiogenesis plays a role in the pathogenesis and progression of these cancers. VEGF, IL-6 and IL-8 seem to contribute to the malignant phenotype.
Novel Peptides Activate GRP78 Heat Shock Protein Receptor as a New Target for Angiogenesis
Authors: Hardy Bri tta , Raiter Annat
Published: April 2020

Background: Impaired angiogenesis is one of the features of ischemic diseases. For the last decade the most established target for therapeutic angiogenesis has been VEGF and its receptors. However clinical trials to alleviate ischemia have been disappointing indicating the need for new molecules and molecular targets. We have identified a heat shock protein GRP78 on endothelial cell membranes as a novel target for angiogenesis that is independent of VEGF. We have demonstrated that binding to this target by a synthetic 12 amino acid peptide RoY induced therapeutic angiogenesis. A single local administration of the peptide significantly restored blood perfusion in mice post femoral artery excision. Recently, we have also demonstrated that intravenous administration of the peptide to mice with acute myocardial infarction resulted in increased capillary density in the ischemic tissue. Our aim was to study membrane GRP78 as a new target for angiogenesis and to identify its natural ligand.

Results: FACS analysis of endothelial cell cultures demonstrated that membrane GRP78 is increased under hypoxic conditions. In order to identify a natural ligand to GRP78, we used protein data base search. ADAM15, a disintegrin and metalloprotease glycoprotein was found to contain four out of twelve identical amino acids to the synthetic RoY peptide. We have therefore synthesized three peptides from the metalloprotease domain and studied endothelial cell binding, proliferation, migration and tube formation under hypoxia in the presence of these peptides. One of the peptides, termed ADoPep1, exhibited a significant angiogenic activity invitro and restored blood perfusion in a mouse hind limb ischemia model. Histological examinations showed an increase in capillary density, a decrease in GRP78 positive cells and apoptotic cells one week post treatment of ischemic leg with ADoPep1. We demonstrated that ADoPep1 inhibited endothelial cell hypoxia-induced apoptosis but not CoCl2 induced apoptosis. We therefore suggest a possible mechanism of angiogenesis by inhibition of hypoxia-induced apoptosis is manifested through GRP78 receptor induced by ADAM15 derived peptide.

Conclusions: The peptide derived from ADAM15 induces angiogenesis by the activation of membrane GRP78 under hypoxia which may lead to the development of novel therapeutics for ischemic diseases. This study contributes to the search for new molecules that activates a new target for therapeutic angiogenesis in ischemic diseases.
Increased Procalcitonin Levels in End Stage Renal Disease and Chronic Kidney Disease as An Indicator of Inflammatory Activation
Authors: Bansal Vinod , Fareed Daniel , Hoppensteadt Debra , Cunanan Josephine , Fareed Jawed
Published: April 2020

Increased levels of procalcitonin (PCT) and other calcitonin precursors are associated with systemic inflammatory responses in patients with burns, trauma or sepsis. Since end stage renal disease (ESRD) and chronic kidney disease (CKD) represent syndromes involving inflammatory responses, we hypothesized that PCT may also be elevated in patients with these pathologic conditions. Apparently sepsis-free blood plasma samples collected from normal donors (n=100) and patients with ESRD(n=67) and CKD (n=67) were retrospectively analyzed for circulating PCT levels using an immunocolorimetric assay (ILMA PCT,BRAHMS, Berlin Germany). This test utilizes two monoclonal antibodies that are directed to the calcitonin and katacalcin portions of PCT. The capturing antibody is immobilized on the surface of the coated tube and a labeled anti-calcitonin is used as a tracer. Diluted plasma samples incubated and both antibodies react with the PCT to form a sandwich complex. The excess tracer antibody is discarded after incubation. The amount of residual tracer is measured in a luminometer. The intensity of luminescence is proportional to the amount of PCT in the sample. PCT levels in normal individuals were 0.24±0.11 ng/ml, whereas higher levels were measured in CKD(0.81±0.35 ng/ml) and ESRD (0.93±0.36 ng/ml). Although wide ranges in the PCT values were observed, the levels were much higher than normal. These studies suggest that patients with ESRD and CKD may exhibit elevated levels of PCT which may not be due to sepsis. Measurement of PCT in these patients may be useful in the risk stratification and clinical management.
Solid Tumors Target the HSC Niche to Establish Metastatic Footholds in the Marrow
Authors: Shiozawa Yusuke , Pedersen Elisabeth A. , Havens Aaron M. , Jung Younghun , Ziegler Anne M. , Pienta Michael J. , Song Junhui , Wang Jingcheng , Loberg Robert D. , Krebsbach Paul H. , Pienta Kenneth J. , Taichman Russell S
Published: April 2020

Metastasis is the most deadly aspect of many solid tissue cancers. The majority of metastases utilize pathways established to regulate hematopoietic stem cell (HSC) homing to gain access to the marrow. Whether solid tumors target the niche to establish footholds in the marrow is unknown. Using prostate caner (PCa) as a model, we determined if PCa and HSC compete for the HSC niche. To determine if disseminated PCa competes for the niche and prevents HSC engraftment, sham-operated or tumor-implanted NOD/SCID mice (Ly5.1) were transplanted with marrow cells from Ly5.2 donor animals. To preserve the niche, the transplanted animals received no preconditioning. At 16 weeks, greater HSC engraftment was observed in sham-operated group than in the tumor-bearing group as reflected by mature HSC progeny in the peripheral blood (0.7 ± 0.4% vs. 0.2 ± 0.2%, p = 0.022). Multiphoton microscopy revealed that PCa and SLAM receptor isolated HSCs co-localize at the endosteal bone surfaces in vivo and in vitro, further suggesting that PCa compete for the niche. Since osteoblasts (OBs) are vital components of the niche, it was determined if alterations in OB numbers also regulates metastasis. Here, vertebrae from control or conditional osteoblast knockout (Col2.3Δ-TK) mice were transplanted into SCID animals. Following treatment with ganciclovir which ablated the osteoblasts, metastasis to these tissues was evaluated. Fewer disseminated PCa were recovered from the Col2.3Δ-TK transplants than vehicle treated transplants (41.6 ± 23.7% vs. 100.0 ± 69.9%, p = 0.009). If metastases target the niche, then we should be able to mobilize metastases using HSC mobilizing regimes. Here, PCa tumors were established and removed. Later G-CSF was administered, and PCa numbers were determined in the blood. More PCa cells were seen in the blood after G-CSF treatments vs. the vehicle group (616.9 ± 463.0 cells vs. 143.7 ± 159.1 cells, p = 0.025). Part of the mechanism responsible for the mobilization of PCa was an increase in the production of MMP-2 and MMP-9 in the marrow. Finally, we evaluated if soluble factors produced by PCa alter HSCs activities. Animals were treated with either control or PCa conditioned medium for 3 days, and then HSC were harvested. Alterations of many mRNA transcripts involved in HSC self renewal were observed in animals exposed to the PCa conditioned medium. Our findings indicate that PCa and HSCs compete for the osteoblastic HSC niche, and that PCa utilize the same mechanisms as HSCs to gain access and egress from the niche. Taken together, these data provide the first evidence that the HSC niche serves as pre-metastatic niche for solid tumors and plays a central role in bone metastases.
A Prospective Phase II Trial of An L-Asparaginase Containing Regimen in Patients with Refractory or Relapsing Extra Nodal NK/T-Cell Lymphoma
Authors: Jaccard Arnaud , Gachard Nathalie , Coppo Paul , Morschhauser Franck , Galicier Lionel , Ysebaert Loic , Lenain Philippe , Corront Bernadette , Suarez Felipe , Feuillard Jean , Gaulard Philippe , Bordessoule Dominique , Hermine Olivier
Published: April 2020

Extra nodal NK/T-cell lymphoma, nasal type, is an EBV-related highly aggressive disease with a poor outcome, especially when disseminated or recurrent after radiotherapy. L-Asparaginase seems to have a particular efficacy in this disease (Jaccard, 2008, Ann oncol). Nineteen patients with relapsing or refractory extra nodal NK/T-Cell Lymphoma, nasal type, were included in a multicentric prospective phase II trial using the Aspametdex regimen (E coli-L-asparaginase (Kidrolase®) 6000 UI/m2 IM at day 2,4,6,8, methotrexate 3 gr/m2 at day 1 and dexamethasone 40 mg at day 1 to 4 with 3 weeks cycles). Patients below 65 years of age and with a good performance status received 3 cycles and, in case of good response, an intensive treatment with the BEAM regimen and stem cell rescue. Other patients received up to 6 cycles of the Aspametdex protocol. Patients with localized disease received irradiation if not performed before inclusion. The histology was centrally reviewed and EBV viremia was regularly and centrally monitored. The response after 3 cycles was the primary end point. There were 14 men and 4 women (1 patient was excluded after pathologic review), median age was 59.5 (45 to 76), 7 were primary refractory, 11 were in relapse, 6 were in stage IV. Median number of cycles was 3 (1 to 6). Three patients who had an allergic reaction with L-asparaginase received further courses of Erwinia-asparaginase (Erwiniase®) (n= 3). Toxicity related to L-asparaginase was mild, mainly brief leucopenia (n=2), elevation of alanine aminotransferase (n=2) and venous thrombosis (n=1). Response was documented in 17/18 patients, 10 patients were in complete remission (CR) after treatment with L-asparaginase and 5 patients in partial remission. Five patients died of unrelated causes (n=1) or progression of disease (n=4). Thirteen patients are still alive with a median follow-up of 8 months (1 to 29), 5 responding patients progressed at 4, 5, 8, 8 and 22 months after treatment. Six patients are in persistent CR, 2 of these patients had received high dose therapy with autologous stem cell transplant and 1 patient received irradiation after L-asparaginase treatment. These data confirm the excellent activity of L-asparaginase-containing regimens in extranodal NK/T-cell lymphoma. This must be known because of the very poor prognosis of patients with disseminated or relapsing disease with conventional chemotherapy. First-line L-asparaginase combination therapy for extranodal NK/T-cell lymphoma should be tested in prospective trials.
Radiation-Free Anti-CD3-Conditioning Regimen Maintains Tissue Protection Mechanisms and Prevents GVHD: Role of Tissue Expression of B7H1
Authors: Chen Ying , Lin Chia-Lei , Li Nainong , Du Gong , Chen Lieping , Forman Stephen , Zeng Defu
Published: April 2020

We reported that donor CD8+ T cells mediated graft versus leukemia (GVL) activity without causing graft versus host disease (GVHD) in anti-CD3-conditioned recipients, although the same dose of donor CD8+ T cells caused lethal GVHD in recipients conditioned with sublethal total body irradiation (TBI) (J. Immunol. 2007). We recently observed that donor CD8+ T cells from the liver of anti-CD3-conditioned recipients showed a marked reduction in proliferation in response to anti-CD3/CD28 stimulation, as compared to those from TBI-conditioned recipients, indicating that donor CD8+ T cells are tolerized in the tissues of anti-CD3-conditioned recipients. B7H1, a co-inhibitory molecule, is constitutively expressed by hematopoietic cells and expressed by parenchymal cells after IFN-γ induction. B7H1 tolerizes T cells by interaction with its ligand PD-1 on activated T cells. To explore the role of B7H1 in GVHD prevention in anti-CD3-conditioned recipients, donor C57BL/6 CD8+ T cells (20×106) and bone marrow cells (100×106) were transplanted into anti-CD3-conditioned wild-type or B7H1−/− BALB/c recipients. While the wild-type recipients all survived for more than 100 days without signs of GVHD, the B7H1−/− recipients developed severe GVHD with diarrhea, weight-loss, and hair-loss, and 70% of them died 60 days after transplantation. Similarly, while donor CD8+ T and BM cells induced little GVHD in unconditioned Rag-2−/− BALB/c recipients, they induced severe lethal GVHD in B7H1−/− Rag-2−/− BALB/c recipients. Furthermore, donor CD8+ T and BM cells still induced lethal GVHD in unconditioned chimeric B7H1−/−Rag-2−/− recipients reconstituted with B7H1+/+Rag-2−/− BM. In addition, we observed upregulation of B7H1 expression by hepatocytes and intestine epithelial cells of anti-CD3-conditioned BALB/c or unconditioned Rag-2−/− recipients after donor cells infusion, as judged by RT-PCR, flow cytometry analysis, and histoimmunostaining of B7H1. In vivo bioluminescent imagine showed much more severe tissue infiltration of donor T cells in B7H1−/− recipients as compared to B7H1+/+ recipients, and the in vitro proliferation of donor CD8+ T cells from the liver of the former recipients was much more vigorous than that of the latter recipients. These results demonstrate that B7H1 expression by tissue parenchymal cells rather than hematopoietic cells tolerizes infiltrating donor T cells in GVHD target tissues and prevents GVHD; and that the radiation-free anti-CD3-conditioning regimen can maintain this tissue protection mechanism.

(This study is surpported by Marcus Foundation and NIH R01 AI 066008).
Characteristics of Iron Dextran Utilization in Man
Authors: HENDERSON PERRY A. , HILLMAN ROBERT S.
Published: April 2020

The major portion of iron dextran iron becomes available to the erythroid marrow only after uptake and release of ionic iron by the reticuloendothelial system. With large intravenous infusions, (1000-2000 mg.), the rate of removal of the iron dextran complex from plasma is enough to supply the marrow with more than 200 mg. of iron/day. However, in the present studies the observed rate of iron delivery to the erythroid marrow was far below this level. Although iron supply immediately after infusion was sufficient to permit marrow production to rise to 4-6 times normal, this was maintained for less than two weeks. With time, reticuloendothelial iron dextran stores became less available, the serum iron level fell and marrow production was restricted to levels below twice normal. In fact, large infusion doses and prolonged storage may have made a portion of the iron dextran stores completely unavailable. Thus, an iron deficient type of erythropoiesis appeared in some patients while iron dextran stores were still readily visible on examination of marrow stroma.
Immunologic Rebound After Cessation of Long-term Chemotherapy in Acute Leukemia. II. In Vitro Response to Phytohemagglutinin and Antigens By Peripheral Blood and Bone Marrow Lymphocytes
Authors: Green Alexander A. , Borella Luis
Published: April 2020

The in vitro function of peripheral blood and bone marrow lymphocytes from 42 children with acute lymphocytic leukemia (ALL) in remission was evaluated before and after cessation of long-term combination immunosuppressive therapy. Lymphocyte function promptly recovers even after 3 yr of antineoplastic therapy, but the immunologic rebound varies, depending on whether the in vitro responses to phytohemagglutinin or various antigens are used as the index of lymphocyte function. The kinetics of immunologic rebound in three patients who relapsed following cessation of therapy did not differ from patients remaining in remission. In children off therapy there was a different distribution of antigen- and PHA-responsive lymphocytes between the peripheral blood and bone marrow compartments. This study provides further information at a cellular level on the immunologic rebound that follows cessation of long-term combination therapy. It emphasizes the need for controls in trials where immunotherapy is given after chemotherapy. Such controls are necessary before one can establish if the observed responses are due to adjuvants and/or tumor cells or are a reflection of the immunologic rebound that follows cessation of immunosuppressive therapy. The data also provide a baseline for future studies of immune impairment before leukemia relapse and the relationship between immunologic rebound and the duration of long-term leukemia-free survival.
Eosinophilic colitis in a boy with a novel XIAP mutation: a case report
Authors: Tang Jiamei , Zhou Xiaoying , Wang Lan , Hu Guorui , Zheng Bixia , Wang Chunli , Lu Yan , Jin Yu , Guo Hongmei , Liu Zhifeng
Published: April 2020

Background

X-linked inhibitor of apoptosis (XIAP) deficiency is a rare primary immunodeficiency disease characterized by haemophagocytic lymphohistiocytosis, recurrent splenomegaly and inflammatory bowel disease (IBD). The only curative treatment is haematopoietic stem cell transplant (HSCT).

Case presentation

Here, we report the case of a 22-month-old male with a long history of abdominal distension and anaemia. Clinical and laboratory findings were consistent with eosinophilic colitis. To identify the underlying disease, we performed exome sequencing, which showed an unreported frameshift mutation in the XIAP gene.

Conclusion

We present eosinophilic colitis as the initial manifestation of XIAP deficiency for the first time in this article, which expands the mutation spectrum and phenotype of this disease.
Tapping into the maize root microbiome to identify bacteria that promote growth under chilling conditions
Authors: Beirinckx Stien , Viaene Tom , Haegeman Annelies , Debode Jane , Amery Fien , Vandenabeele Steven , Nelissen Hilde , Inzé Dirk , Tito Raul , Raes Jeroen , De Tender Caroline , Goormachtig Sofie
Published: April 2020

Background

When maize (Zea mays L.) is grown in the Northern hemisphere, its development is heavily arrested by chilling temperatures, especially at the juvenile phase. As some endophytes are beneficial for plants under stress conditions, we analyzed the impact of chilling temperatures on the root microbiome and examined whether microbiome-based analysis might help to identify bacterial strains that could promote growth under these temperatures.

Results

We investigated how the maize root microbiome composition changed by means of 16S rRNA gene amplicon sequencing when maize was grown at chilling temperatures in comparison to ambient temperatures by repeatedly cultivating maize in field soil. We identified 12 abundant and enriched bacterial families that colonize maize roots, consisting of bacteria recruited from the soil, whereas seed-derived endophytes were lowly represented. Chilling temperatures modified the root microbiome composition only slightly, but significantly. An enrichment of several chilling-responsive families was detected, of which the Comamonadaceae and the Pseudomonadaceae were the most abundant in the root endosphere of maize grown under chilling conditions, whereas only three were strongly depleted, among which the Streptomycetaceae. Additionally, a collection of bacterial strains isolated from maize roots was established and a selection was screened for growth-promoting effects on juvenile maize grown under chilling temperatures. Two promising strains that promoted maize growth under chilling conditions were identified that belonged to the root endophytic bacterial families, from which the relative abundance remained unchanged by variations in the growth temperature.

Conclusions

Our analyses indicate that chilling temperatures affect the bacterial community composition within the maize root endosphere. We further identified two bacterial strains that boost maize growth under chilling conditions. Their identity revealed that analyzing the chilling-responsive families did not help for their identification. As both strains belong to root endosphere enriched families, visualizing and comparing the bacterial diversity in these communities might still help to identify new PGPR strains. Additionally, a strain does not necessarely need to belong to a high abundant family in the root endosphere to provoke a growth-promoting effect in chilling conditions.
Visual chunking as a strategy for spatial thinking in STEM
Authors: Stieff Mike , Werner Stephanie , DeSutter Dane , Franconeri Steve , Hegarty Mary
Published: April 2020

Working memory capacity is known to predict the performance of novices and experts on a variety of tasks found in STEM (Science, Technology, Engineering, and Mathematics). A common feature of STEM tasks is that they require the problem solver to encode and transform complex spatial information depicted in disciplinary representations that seemingly exceed the known capacity limits of visuospatial working memory. Understanding these limits and how visuospatial information is encoded and transformed differently by STEM learners presents new avenues for addressing the challenges students face while navigating STEM classes and degree programs. Here, we describe two studies that explore student accuracy at detecting color changes in visual stimuli from the discipline of chemistry. We demonstrate that both naive and novice chemistry students’ encoding of visuospatial information is affected by how information is visually structured in “chunks” prevalent across chemistry representations. In both studies we show that students are more accurate at detecting color changes within chemistry-relevant chunks compared to changes that occur outside of them, but performance was not affected by the dimensionality of the structure (2D vs 3D) or the presence of redundancies in the visual representation. These studies support the hypothesis that strategies for chunking the spatial structure of information may be critical tools for transcending otherwise severely limited visuospatial capacity in the absence of expertise.
The Impact of Disuse and High-Fat Overfeeding on Forearm Muscle Amino Acid Metabolism in Humans
Authors: Wall Benjamin T , Cruz Ana M , Otten Britt , Dunlop Mandy V , Fulford Jonathan , Porter Craig , Abdelrahman Doaa Reda , Stephens Francis B , Dirks Marlou L
Published: April 2020

Context

Anabolic resistance is mechanistically implicated in muscle disuse atrophy.

Objective

The objective of this study is to assess whether anabolic resistance is associated with reduced postprandial amino acid uptake or exacerbated by excess lipid availability.

Design, Setting, Participants, and Interventions

Twenty men underwent 7 days of forearm immobilization while consuming a eucaloric (CON; n = 11) or high-fat overfeeding (HFD; n = 9; 50% excess energy as fat) diet (parallel design) within our Nutritional Physiology Research Unit.

Main Outcome Measures

Preimmobilization and postimmobilization we measured forearm muscle cross-sectional area (aCSA), and postabsorptive and postprandial (3-hour postingestion of a liquid, protein-rich, mixed meal) forearm amino acid metabolism using the arterialized venous-deep venous balance method and infusions of L-[ring-2H5]phenylalanine and L-[1-13C]leucine.

Results

Immobilization did not affect forearm muscle aCSA in either group, but tended to reduce postabsorptive phenylalanine (P = .07) and leucine (P = .05) net balances equivalently in CON and HFD. Mixed-meal ingestion switched phenylalanine and leucine net balances from negative to positive (P < .05), an effect blunted by immobilization (P < .05) and to a greater extent in HFD than CON (P < .05). Preimmobilization, meal ingestion increased leucine rates of disappearance (Rd; P < .05), with values peaking at 191% (from 87 ± 38 to 254 ± 60 µmol·min–1·100 mL forearm volume–1) and 183% (from 141 ± 24 to 339 ± 51 µmol·min–1·100 mL–1) above postabsorptive rates in CON and HFD, respectively, with meal-induced increases not evident postimmobilization in either group (P > .05).

Conclusions

Disuse impairs the ability of a protein-rich meal to promote positive muscle amino acid balance, which is aggravated by dietary lipid oversupply. Moreover, disuse reduced postprandial forearm amino acid uptake; however, this is not worsened under high-fat conditions.
Retention and Migration of Rwandan Anesthesiologists: A Qualitative Study
Authors: Skelton Teresa , Irakoze Alain , Bould M. Dylan , Przybylak-Brouillard Antoine , Twagirumugabe Theogene , Livingston Patricia
Published: April 2020

BACKGROUND:

Health care professional migration continues to challenge countries where the lack of surgical and anesthesia specialists results in being unable to address the global burden of surgical disease in their populations. Medical migration is particularly damaging to health care systems that are just beginning to scale up capacity building of human resources for health. Anesthesiologists are scarce in low-resource settings. Defining reasons why anesthesiologists leave their country of training through in-depth interviews may provide guidance to policy makers and academic organizations on how to retain valuable health professionals.

METHODS:

There were 24 anesthesiologists eligible to participate in this qualitative interview study, 15 of whom are currently practicing in Rwanda and 9 had left the country. From the eligible group, interviews were conducted with 13 currently practicing in Rwanda and 2 who had left to practice elsewhere. In-depth interviews of approximately 60 minutes were used to define themes influencing retention and migration among anesthesiologists in Rwanda. Interviews were conducted using a semistructured guide and continued until theoretical sufficiency was reached. Thematic analysis was done by 4 members of the research team using open coding to inductively identify themes.

RESULTS:

Interpretation of results used the framework categorizing themes into push, pull, stick, and stay to describe factors that influence migration, or the potential for migration, of anesthesiologists in Rwanda. While adequate salary is essential to retention of anesthesiologists in Rwanda, other factors such as lack of equipment and medication for safe anesthesia, isolation, and demoralization are strong push factors. Conversely, a rich academic life and optimism for the future encourage anesthesiologists to stay.

CONCLUSIONS:

Our study suggests that better clinical resources and equipment, a more supportive community of practice, and advocacy by mentors and academic partners could encourage more staff anesthesiologists to stay and work in Rwanda.
Blood Utilization and Clinical Outcomes in Extracorporeal Membrane Oxygenation Patients
Authors: Qin Caroline X. , Yesantharao Lekha V. , Merkel Kevin R. , Goswami Dheeraj K. , Garcia Alejandro V. , Whitman Glenn J. R. , Frank Steven M. , Bembea Melania M.
Published: April 2020

BACKGROUND:

Patients requiring extracorporeal membrane oxygenation (ECMO) support are critically ill and have substantial transfusion requirements, which convey both risks and benefits. A retrospective analysis was conducted to assess the association between blood component administration and adverse outcomes in adult, pediatric, and neonatal ECMO patients.

METHODS:

We evaluated 217 ECMO patients at a single center hospitalized between January 2009 and June 2016. Three cohorts (88 adult, 57 pediatric, and 72 neonatal patients) were included for assessment of patient characteristics, blood utilization, and clinical outcomes. Univariable and multivariable analyses were used to assess the association between transfusions and clinical outcomes (primary outcome: mortality and secondary outcomes: morbid events). The analysis included the main exposure of interest (total number of blood component units transfused) and potential confounding variables (age group cohort, case mix index, sex, ECMO mode and duration, and primary ECMO indication).

RESULTS:

After adjustment for confounders, with each additional blood component unit transfused, there was an estimated increase in odds for mortality by 1% (odds ratio [OR] = 1.01; 95% confidence interval [CI], 1.00–1.02; P = .013) and an increase in odds for thrombotic events by 1% (OR = 1.01; 95% CI, 1.00–1.02; P = .007). Mortality was higher in the adult (57 of 88; 64.8%) and pediatric (37 of 57; 64.9%) than in the neonatal cohort (19 of 72; 26.4%) (P < .0001). Median total blood components transfused per day followed a similar pattern for the adult (2.3 units; interquartile range [IQR] = 0.8–7.0), pediatric (2.9 units; IQR = 1.1–10), and neonatal (1.0 units; IQR = 0.7–1.6) cohorts (P < .0001). Over the entire hospitalization, the total median blood components transfused was highest in the neonatal (41 units; IQR = 24–94) and pediatric (41 units; IQR = 17–113) compared to the adult (30 units; IQR = 9–58) cohort (P = .007). There was no significant interaction between total units transfused over the hospital stay and age cohort for mortality (P = .35).

CONCLUSIONS:

Given the association between transfusion and adverse outcomes, effective blood management strategies may be beneficial in ECMO patients.
Health Numeracy and Relative Risk Comprehension in Perioperative Patients and Physicians
Authors: Hayter Ryan R. , Hess Aaron S.
Published: April 2020

BACKGROUND:

Helping patients to understand relative risks is challenging. In discussions with patients, physicians often use numbers to describe hazards, make comparisons, and establish relevance. Patients with a poor understanding of numbers—poor “health numeracy”—also have difficulty making decisions and coping with chronic conditions. Although the importance of “health literacy” in perioperative populations is recognized, health numeracy has not been well studied. Our aim was to compare understanding of numbers, risk, and risk modification between a patient population awaiting surgery under general anesthesia and attending physicians at the same center.

METHODS:

We performed a single-center cross-sectional survey study to compare patients’ and physicians’ health numeracy. The study instrument was based on the Schwartz–Lipkus survey and included 3 simple health numeracy questions and 2 risk reduction questions in the anesthesiology domain. The survey was mailed to patients over the age of 18 scheduled for elective surgery under general anesthesia between June and September 2019, as well as attending physicians at the study center.

RESULTS:

Two hundred thirteen of 502 (42%) patient surveys sent and 268 of 506 (53%) physician surveys sent were returned. Median patient score was 4 of 5, but 32% had a score of ≤3. Patients significantly overestimated their total scores by an average of 0.5 points (estimated [mean ± standard deviation (SD)] = 4.3 ± 1.2 vs actual 3.8 ± 1.3; P < .001). Health numeracy was significantly associated with higher educational level (gamma = 0.351; P < .001) and higher-income level (gamma = 0.397; P < .001). Physicians’ health numeracy was significantly higher than the patients’ (median [interquartile range {IQR}] = 5 [4–5] vs 4 [3–5]; P < .001). There was no significant difference between physicians’ self-estimated and actual total numeracy score (mean ± SD = 4.8 ± 0.6 vs 4.7 ± 0.6; P = .372). Simple health numeracy (questions 1–3) was predictive of correct risk reduction responses (questions 4, 5) for both patients (gamma = 0.586; P < .001) and physicians (gamma = 0.558; P = .006).

CONCLUSIONS:

Patients had poor health numeracy compared to physicians and tended to overrate their abilities. A small proportion of physicians also had poor numeracy. Poor health numeracy was associated with incomprehension of risk modification, suggesting that some patients may not understand treatment efficacy. These disparities suggest a need for further inquiry into how to improve patient comprehension of risk modification.
Novel RF-source-free reconfigurable microwave photonic radar
Authors: Zhang Xiangpeng , Zeng Henan , Yang Jiyao , Yin Ziqiang , Sun Qiang , Li Wangzhe
Published: April 2020

A novel reconfigurable microwave photonic (MWP) radar has been proposed and experimentally demonstrated. At a transmitting end, a microwave signal with a large bandwidth and ultra-low phase noise is generated by a Fourier domain mode locking optoelectronic oscillator. At a receiving end, photonics-based de-chirp processing is implemented by phase-modulating light waves in a dual-drive Mach-Zehnder modulator and mixing the modulated light waves at a photodetector. Without the requirement of external RF sources, the developed photonics-assisted programmable radar is capable of generating and processing microwave signals with adjustable format, bandwidth and central frequency. The proposed radar working from X to Ku band with an instantaneous bandwidth of 2 GHz is demonstrated. The reconfiguration of the radar is theoretically analyzed. The tunability of radar bandwidth and central frequency is investigated. Microwave imaging of a pair of trihedral corner reflectors based on the developed MWP radar is achieved.
Hitless and gridless reconfigurable optical add drop (de)multiplexer based on looped waveguide sidewall Bragg gratings on silicon
Authors: Wang Xiaofei , Yu Hui , Qiu Huiye , Zhang Qiang , Fu Zhilei , Xia Penghui , Chen Bei , Guo Xiaoqing , Wang Yuehai , Jiang Xiaoqing , Yang Jianyi
Published: April 2020

Reconfigurable optical add-drop filters in future intelligent and software controllable wavelength division multiplexing networks should support hitless wavelength switching and gridless bandwidth tuning. The hitless switching implies that the central wavelength of one channel can be shifted without disturbing data transmissions of other channels, while the gridless tuning means that the filter bandwidth can be adjusted continuously. Despite a lot of efforts, very few integrated optical filters simultaneously support the hitless switching of central wavelength and the gridless tuning of bandwidth. In this work, we demonstrate a hitless add-drop filter with gridless bandwidth tunability on the silicon-on-insulator (SOI) platform. The filter comprises the two identical multimode anti-symmetric waveguide Bragg gratings (MASWBG) which are connected to a loop. The phase apodization technique is utilized to weaken the intrinsic sidelobe interference of grating-based devices. By sequentially manipulating central wavelengths of the two MASWBGs with the thermo-optical effect, we can reconfigure the spectral response of the filter gridlessly and hitlessly. Specifically, the central wavelength of the device is shifted by 14.5 nm, while its 3 dB bandwidth is tuned from 0.2 nm to 2.4 nm. The dropping loss and the sidelobe suppression ratio (SLSR) are dependent on the bandwidth selected. Measured variation ranges of dropping loss and SLSR are from -1.2 dB to -2.5 dB and from 12.8 dB to 21.4 dB, respectively. The hitless wavelength switching is verified by a data transmission measurement at a bit rate of 25 Gbps.
Geometric stitching of a HaiYang-1C ultra violet imager with a distorted virtual camera
Authors: Cao Jinshan , Zhang Zhiqi , Jin Shuying , Chang Xueli
Published: April 2020

The HaiYang-1C (HY-1C) ultra violet imager (UVI) consists of five independent cameras with a designed total image swath of approximately 3000 km. In order to obtain a complete seamless image formed by the five sub-images, a feasible geometric stitching method for the HY-1C UVI with a distorted virtual camera is proposed. First, we perform the absolute geometric calibration of camera 3 and the relative geometric calibration of cameras 1, 2, 4, and 5. Then, a distorted virtual camera is assigned. Finally, the five sub-images are stitched together with the distorted virtual camera. Three HY-1C UVI images were tested. The experimental results showed that the georeferencing accuracy of the stitched images was better than 1 pixel. Compared with the conventional stitching method with an undistorted virtual camera, the ground sampling distance differences of the five cameras obtained by the proposed method were reduced from 23%, 37%, 53%, 37%, and 25% to 6%, 6%, 1%, 7%, and 8%, respectively.
Dynamic 3-D shape measurement in an unlimited depth range based on adaptive pixel-by-pixel phase unwrapping
Authors: Duan Minghui , Jin Yi , Chen Huaian , Kan Yan , Zhu Changan , Chen Enhong
Published: April 2020

Pixel-by-pixel phase unwrapping (PPU) has been employed to rapidly achieve three-dimensional (3-D) shape measurement without additional projection patterns. However, the maximum measurement depth range that traditional PPU can handle is within 2π in phase domain; thus PPU fails to measure the dynamic object surface when the object moves in a large depth range. In this paper, we propose a novel adaptive pixel-by-pixel phase unwrapping (APPU), which extends PPU to an unlimited depth range. First, with PPU, temporary phase maps of objects are obtained referring to the absolute phase map of a background plane. Second, we quantify the difference between the image edges of the temporary phase maps and the practical depth edges of dynamic objects. Moreover, according to the degree of the edge difference, the temporary phase maps are categorized into two classes: failed phase maps and relative phase maps. Third, by combining a mobile reference phase map and the edge difference quantization technique, the failed phase maps are correspondently converted into relative phase maps. Finally, the relative phase maps are innovatively transformed into the absolute phase maps using a new shadow-informed depth estimation method (SDEM). The proposed approach is suitable for high-speed 3-D shape measurement without depth limitations or additional projection patterns.