Guest editorial

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Probiotic prophylaxis in patients with predicted severe acute pancreatitis (PROPATRIA): design and rationale of a double-blind, placebo-controlled randomised multicenter trial [ISRCTN38327949]

BACKGROUND: Infectious complications are the major cause of death in acute pancreatitis. Small bowel bacterial overgrowth and subsequent bacterial translocation are held responsible for the vast majority of these infections. Goal of this study is to determine whether selected probiotics are capable of preventing infectious complications without the disadvantages of antibiotic prophylaxis; antibiotic resistance and fungal overgrowth. METHODS/DESIGN: PROPATRIA is a double-blind, placebo-controlled randomised multicenter trial in which 200 patients will be randomly allocated to a multispecies probiotic preparation (Ecologic 641) or placebo. The study is performed in all 8 Dutch University Hospitals and 7 non-University hospitals. The study-product is administered twice daily through a nasojejunal tube for 28 days or until discharge. Patients eligible for randomisation are adult patients with a first onset of predicted severe acute pancreatitis: Imrie criteria 3 or more, CRP 150 mg/L or more, APACHE II score 8 or more. Exclusion criteria are post-ERCP pancreatitis, malignancy, infection/sepsis caused by a second disease, intra-operative diagnosis of pancreatitis and use of probiotics during the study. Administration of the study product is started within 72 hours after onset of abdominal pain. The primary endpoint is the total number of infectious complications. Secondary endpoints are mortality, necrosectomy, antibiotic resistance, hospital stay and adverse events. To demonstrate that probiotic prophylaxis reduces the proportion of patients with infectious complications from 50% to 30%, with alpha 0,05 and power 80%, a total sample size of 200 patients was calculated. CONCLUSION: The PROPATRIA study is aimed to show a reduction in infectious complications due to early enteral use of multispecies probiotics in severe acute pancreatitis

Nel positively regulates the genesis of retinal ganglion cells by promoting their differentiation and survival during development

Peer reviewedPublisher PD

Targeting and Function of the Mitochondrial Fission Factor GDAP1 Are Dependent on Its Tail-Anchor

Proteins controlling mitochondrial dynamics are often targeted to and anchored into the mitochondrial outer membrane (MOM) by their carboxyl-terminal tail-anchor domain (TA). However, it is not known whether the TA modulates protein function. GDAP1 is a mitochondrial fission factor with two neighboring hydrophobic domains each flanked by basic amino acids (aa). Here we define GDAP1 as TA MOM protein. GDAP1 carries a single transmembrane domain (TMD) that is, together with the adjacent basic aa, critical for MOM targeting. The flanking N-terminal region containing the other hydrophobic domain is located in the cytoplasm. TMD sequence, length, and high hydrophobicity do not influence GDAP1 fission function if MOM targeting is maintained. The basic aa bordering the TMD in the cytoplasm, however, are required for both targeting of GDAP1 as part of the TA and GDAP1-mediated fission. Thus, this GDAP1 region contains critical overlapping motifs defining intracellular targeting by the TA concomitant with functional aspects

Early cellular signaling responses to axonal injury

<p>Abstract</p> <p>Background</p> <p>We have used optic nerve injury as a model to study early signaling events in neuronal tissue following axonal injury. Optic nerve injury results in the selective death of retinal ganglion cells (RGCs). The time course of cell death takes place over a period of days with the earliest detection of RGC death at about 48 hr post injury. We hypothesized that in the period immediately following axonal injury, there are changes in the soma that signal surrounding glia and neurons and that start programmed cell death. In the current study, we investigated early changes in cellular signaling and gene expression that occur within the first 6 hrs post optic nerve injury.</p> <p>Results</p> <p>We found evidence of cell to cell signaling within 30 min of axonal injury. We detected differences in phosphoproteins and gene expression within the 6 hrs time period. Activation of TNFα and glutamate receptors, two pathways that can initiate cell death, begins in RGCs within 6 hrs following axonal injury. Differential gene expression at 6 hrs post injury included genes involved in cytokine, neurotrophic factor signaling (Socs3) and apoptosis (Bax).</p> <p>Conclusion</p> <p>We interpret our studies to indicate that both neurons and glia in the retina have been signaled within 30 min after optic nerve injury. The signals are probably initiated by the RGC soma. In addition, signals activating cellular death pathways occur within 6 hrs of injury, which likely lead to RGC degeneration.</p

Maternal Antibody Transmission in Relation to Mother Fluctuating Asymmetry in a Long-Lived Colonial Seabird: The Yellow-Legged Gull Larus michahellis

Female birds transfer antibodies to their offspring via the egg yolk, thus possibly providing passive immunity against infectious diseases to which hatchlings may be exposed, thereby affecting their fitness. It is nonetheless unclear whether the amount of maternal antibodies transmitted into egg yolks varies with female quality and egg laying order. In this paper, we investigated the transfer of maternal antibodies against type A influenza viruses (anti-AIV antibodies) by a long-lived colonial seabird, the yellow-legged gull (Larus michahellis), in relation to fluctuating asymmetry in females, i.e. the random deviation from perfect symmetry in bilaterally symmetric morphological and anatomical traits. In particular, we tested whether females with greater asymmetry transmitted fewer antibodies to their eggs, and whether within-clutch variation in yolk antibodies varied according to the maternal level of fluctuating asymmetry. We found that asymmetric females were in worse physical condition, produced fewer antibodies, and transmitted lower amounts of antibodies to their eggs. We also found that, within a given clutch, yolk antibody level decreased with egg laying order, but this laying order effect was more pronounced in clutches laid by the more asymmetric females. Overall, our results support the hypothesis that maternal quality interacts with egg laying order in determining the amount of maternal antibodies transmitted to the yolks. They also highlight the usefulness of fluctuating asymmetry as a sensitive indicator of female quality and immunocompetence in birds

Diagnostic strategy and timing of intervention in infected necrotizing pancreatitis: an international expert survey and case vignette study

AbstractBackgroundThe optimal diagnostic strategy and timing of intervention in infected necrotizing pancreatitis is subject to debate. We performed a survey on these topics amongst a group of international expert pancreatologists.MethodsAn online survey including case vignettes was sent to 118 international pancreatologists. We evaluated the use and timing of fine needle aspiration (FNA), antibiotics, catheter drainage and (minimally invasive) necrosectomy.ResultsThe response rate was 74% (N = 87). None of the respondents use FNA routinely, 85% selectively and 15% never. Most respondents (87%) use a step-up approach in patients with infected necrosis. Walled-off necrosis (WON) is considered a prerequisite for endoscopic drainage and percutaneous drainage by 66% and 12%, respectively. After diagnosing infected necrosis, 55% routinely postpone invasive interventions, whereas 45% proceed immediately to intervention. Lack of consensus about timing of intervention was apparent on day 14 with proven infected necrosis (58% intervention vs. 42% non-invasive) as well as on day 20 with only clinically suspected infected necrosis (59% intervention vs. 41% non-invasive).DiscussionThe step-up approach is the preferred treatment strategy in infected necrotizing pancreatitis amongst expert pancreatologists. There is no uniformity regarding the use of FNA and timing of intervention in the first 2–3 weeks of infected necrotizing pancreatitis

In Situ Dividing and Phagocytosing Retinal Microglia Express Nestin, Vimentin, and NG2 In Vivo

BACKGROUND: Following injury, microglia become activated with subsets expressing nestin as well as other neural markers. Moreover, cerebral microglia can give rise to neurons in vitro. In a previous study, we analysed the proliferation potential and nestin re-expression of retinal macroglial cells such as astrocytes and Müller cells after optic nerve (ON) lesion. However, we were unable to identify the majority of proliferative nestin(+) cells. Thus, the present study evaluates expression of nestin and other neural markers in quiescent and proliferating microglia in naïve retina and following ON transection in adult rats in vivo. METHODOLOGY/PRINCIPAL FINDINGS: For analysis of cell proliferation and cells fates, rats received BrdU injections. Microglia in retinal sections or isolated cells were characterized using immunofluorescence labeling with markers for microglia (e.g., Iba1, CD11b), cell proliferation, and neural cells (e.g., nestin, vimentin, NG2, GFAP, Doublecortin etc.). Cellular analyses were performed using confocal laser scanning microscopy. In the naïve adult rat retina, about 60% of resting ramified microglia expressed nestin. After ON transection, numbers of nestin(+) microglia peaked to a maximum at 7 days, primarily due to in situ cell proliferation of exclusively nestin(+) microglia. After 8 weeks, microglia numbers re-attained control levels, but 20% were still BrdU(+) and nestin(+), although no further local cell proliferation occurred. In addition, nestin(+) microglia co-expressed vimentin and NG2, but not GFAP or neuronal markers. Fourteen days after injury and following retrograde labeling of retinal ganglion cells (RGCs) with Fluorogold (FG), nestin(+)NG2(+) microglia were positive for the dye indicating an active involvement of a proliferating cell population in phagocytosing apoptotic retinal neurons. CONCLUSIONS/SIGNIFICANCE: The current study provides evidence that in adult rat retina, a specific resident population of microglia expresses proteins of immature neural cells that are involved in injury-induced cell proliferation and phagocytosis while transdifferentiation was not observed

Generation of Novel Bone Forming Cells (Monoosteophils) from the Cathelicidin-Derived Peptide LL-37 Treated Monocytes

Bone generation and maintenance involve osteoblasts, osteoclasts, and osteocytes which originate from unique precursors and rely on key growth factors for differentiation. However, an incomplete understanding of bone forming cells during wound healing has led to an unfilled clinical need such as nonunion of bone fractures. Since circulating monocytes are often recruited to sites of injury and may differentiate into various cell types including osteoclasts, we investigated the possibility that circulating monocytes in the context of tissue injury may also contribute to bone repair. In particular, we hypothesized that LL-37 (produced from hCAP-18, cathelicidin), which recruits circulating monocytes during injury, may play a role in bone repair.Treatment of monocytes from blood with LL-37 for 6 days resulted in their differentiation to large adherent cells. Growth of LL-37-differentiated monocytes on osteologic discs reveals bone-like nodule formation by scanning electron microscopy (SEM). In vivo transplantation studies in NOD/SCID mice show that LL-37-differentiated monocytes form bone-like structures similar to endochondral bone formation. Importantly, LL-37-differentiated monocytes are distinct from conventional monocyte-derived osteoclasts, macrophages, and dendritic cells and do not express markers of the mesenchymal stem cells (MSC) lineage, distinguishing them from the conventional precursors of osteoblasts. Furthermore, LL-37 differentiated monocytes express intracellular proteins of both the osteoblast and osteoclast lineage including osteocalcin (OC), osteonectin (ON), bone sialoprotein II (BSP II), osteopontin (OP), RANK, RANKL, MMP-9, tartrate resistant acid phosphatase (TRAP), and cathepsin K (CK).Blood derived monocytes treated with LL-37 can be differentiated into a novel bone forming cell that functions both in vitro and in vivo. We propose the name monoosteophil to indicate their monocyte derived lineage and their bone forming phenotype. These cells may have wide ranging implications in the clinic including repair of broken bones and treatment of osteoporosis