118 research outputs found

    The simian immunodeficiency virus Δnef vaccine, after application to the tonsils of rhesus macaques, replicates primarily within CD4+ T cells and elicits a local perforin-positive CD8+ T-cell response

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    Deletion of the nef gene from simian immunodeficiency virus (SIV) strain SIVmac239 yields a virus that undergoes attenuated growth in rhesus macaques and offers substantial protection against a subsequent challenge with some SIV wild-type viruses. We used a recently described model to identify sites in which the SIVΔnef vaccine strain replicates and elicits immunity in vivo. A high dose of SIVΔnef was applied to the palatine and lingual tonsils, where it replicated vigorously in this portal of entry at 7 days. Within 2 weeks, the virus had spread and was replicating actively in axillary lymph nodes, primarily in extrafollicular T-cell-rich regions but also in germinal centers. At this time, large numbers of perforin-positive cells, both CD8+ T cells and CD3-negative presumptive natural killer cells, were found in the tonsil and axillary lymph nodes. The number of infected cells and perforin-positive cells then fell. When autopsy studies were carried out at 26 weeks, only 1 to 3 cells hybridized for viral RNA per section of lymphoid tissue. Nevertheless, infected cells were detected chronically in most lymphoid organs, where the titers of infectious virus could exceed by a log or more the titers in blood. Immunocytochemical labeling at the early active stages of infection showed that cells expressing SIVΔnef RNA were CD4+ T lymphocytes. A majority of infected cells were not in the active cell cycle, since 60 to 70% of the RNA-positive cells in tissue sections lacked the Ki-67 cell cycle antigen, and both Ki-67-positive and -negative cells had similar grain counts for viral RNA. Macrophages and dendritic cells, identified with a panel of monoclonal antibodies to these cells, were rarely infected. We conclude that the attenuated growth and protection observed with the SIVΔnef vaccine strain does not require that the virus shift its characteristic site of replication, the CD4+ T lymphocyte. In fact, this immunodeficiency virus can replicate actively in CD4+ T cells prior to being contained by the host, at least in part by a strong killer cell response that is generated acutely in the infected lymph nodes

    Agenda praktijkgericht onderzoek health:Topsector Life Sciences & Health

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    De Regiegroep van de topsector Life Sciences & Health wil een impuls geven aan initiatieven die praktijkgericht onderzoek op het gebied van Health betreffen. De redenen hiervoor zijn de relatief bescheiden positie van Health vergeleken bij de Life Sciences in de eerdere agendering onder de topsector en de verwachting dat praktijkgericht onderzoek door hogescholen een substantiële bijdrage kan leveren aan de doelstellingen onder het topsectorenbeleid. Daarom is opdracht gegeven tot het opstellen van een agenda voor praktijkgericht onderzoek “Health”. Deze agenda moet leiden tot samenwerking met een solide economische component tussen hogescholen, eventuele andere kennisinstellingen en publieke en private partijen uit de beroepspraktijk. De Agenda Praktijkgericht Onderzoek Health is ingedeeld in vier overkoepelende thema’s (A - D) waarop het onderzoek van hogescholen zich zou moeten richten. Binnen elk thema zijn onderwerpen benoemd die op basis van deze verkenning prioriteit verdienen

    A critical appraisal of the potential benefit of post-operative structured follow-up after resection for biliary tract cancer

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    BACKGROUND: There is currently no evidence to support structured use of imaging or biomarkers during follow-up of patients after curative resection of biliary tract cancer (BTC). Besides, the influence of early detection of recurrence and subsequent start of palliative chemotherapy on overall survival remains unknown. The aim of this study is to describe and compare the results of two follow-up strategies. METHODS: This retrospective multicenter cohort study compared patients from the Amsterdam UMC undergoing pragmatic clinical follow-up, to patients from the observational cohort of the BILCAP study undergoing structured follow-up. Primary outcome was overall survival. RESULTS: A total of 315 patients were included n=91 pragmatic, n=224 structured follow-up). At median follow-up of 56.9 months, 189 (60%) patients were diagnosed with recurrence. After recurrence, more patients received palliative (chemo) therapy in the structured group (43% vs 75%, P<0.001). Median overall survival was lower in the pragmatic group (27.7 vs 39.1 months, P=0.003). Median overall survival of patients who actually received chemotherapy was comparable (27.2 vs 27.7 months, P=0.574). CONCLUSION: This study describes the results of two follow-up strategies. Although these groups are biased, it is noted that after pragmatic follow-up fewer patients received palliative chemotherapy but that those who actually received chemotherapy had similar overall survival compared to patients undergoing structured follow-up

    Agenda praktijkgericht onderzoek health:Topsector Life Sciences &amp; Health

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    Robotic Versus Open Hepatic Arterial Infusion Pump Placement for Unresectable Intrahepatic Cholangiocarcinoma

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    Background: Hepatic arterial infusion pump (HAIP) chemotherapy is an effective treatment for patients with unresectable intrahepatic cholangiocarcinoma (iCCA). HAIP chemotherapy requires a catheter inserted in the gastroduodenal artery and a subcutaneous pump. The catheter can be placed using an open or robotic approach. Objective: This study aimed to compare perioperative outcomes of robotic versus open HAIP placement in patients with unresectable iCCA. Methods: We analyzed patients with unresectable iCCA included in the PUMP-II trial from January 2020 to September 2022 undergoing robotic or open HAIP placement at Amsterdam UMC, Erasmus MC, and UMC Utrecht. The primary outcome was time to functional recovery (TTFR). Results: In total, 22 robotic and 28 open HAIP placements were performed. The median TTFR was 2 days after robotic placement versus 5 days after open HAIP placement (p &lt; 0.001). One patient (4.5%) in the robotic group underwent a conversion to open because of a large bulky tumor leaning on the hilum immobilizing the liver. Postoperative complications were similar—36% (8/22) after robotic placement versus 39% (11/28) after open placement (p = 1.000). The median length of hospital stay was shorter in the robotic group—3 versus 5 days (p &lt; 0.001). All 22 robotic patients initiated HAIP chemotherapy post-surgery, i.e. 93% (26/28) in the open group (p = 0.497). The median time to start HAIP chemotherapy was 14 versus 18 days (p = 0.153). Conclusion: Robotic HAIP placement in patients with unresectable iCCA is a safe and effective procedure and is associated with a significantly shorter TTFR and hospital stay than open HAIP placement.</p

    Robotic Versus Open Hepatic Arterial Infusion Pump Placement for Unresectable Intrahepatic Cholangiocarcinoma

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    Background: Hepatic arterial infusion pump (HAIP) chemotherapy is an effective treatment for patients with unresectable intrahepatic cholangiocarcinoma (iCCA). HAIP chemotherapy requires a catheter inserted in the gastroduodenal artery and a subcutaneous pump. The catheter can be placed using an open or robotic approach. Objective: This study aimed to compare perioperative outcomes of robotic versus open HAIP placement in patients with unresectable iCCA. Methods: We analyzed patients with unresectable iCCA included in the PUMP-II trial from January 2020 to September 2022 undergoing robotic or open HAIP placement at Amsterdam UMC, Erasmus MC, and UMC Utrecht. The primary outcome was time to functional recovery (TTFR). Results: In total, 22 robotic and 28 open HAIP placements were performed. The median TTFR was 2 days after robotic placement versus 5 days after open HAIP placement (p &lt; 0.001). One patient (4.5%) in the robotic group underwent a conversion to open because of a large bulky tumor leaning on the hilum immobilizing the liver. Postoperative complications were similar—36% (8/22) after robotic placement versus 39% (11/28) after open placement (p = 1.000). The median length of hospital stay was shorter in the robotic group—3 versus 5 days (p &lt; 0.001). All 22 robotic patients initiated HAIP chemotherapy post-surgery, i.e. 93% (26/28) in the open group (p = 0.497). The median time to start HAIP chemotherapy was 14 versus 18 days (p = 0.153). Conclusion: Robotic HAIP placement in patients with unresectable iCCA is a safe and effective procedure and is associated with a significantly shorter TTFR and hospital stay than open HAIP placement.</p

    Peroxicretion: a novel secretion pathway in the eukaryotic cell

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    Background: Enzyme production in microbial cells has been limited to secreted enzymes or intracellular enzymes followed by expensive down stream processing. Extracellular enzymes consists mainly of hydrolases while intracellular enzymes exhibit a much broader diversity. If these intracellular enzymes could be secreted by the cell the potential of industrial applications of enzymes would be enlarged. Therefore a novel secretion pathway for intracellular proteins was developed, using peroxisomes as secretion vesicles. Results: Peroxisomes were decorated with a Golgi derived v-SNARE using a peroxisomal membrane protein as an anchor. This allowed the peroxisomes to fuse with the plasma membrane. Intracellular proteins were transported into the peroxisomes by adding a peroxisomal import signal (SKL tag). The proteins which were imported in the peroxisomes, were released into the extracellular space through this artificial secretion pathway which was designated peroxicretion. This concept was supported by electron microscopy studies. Conclusion: Our results demonstrate that it is possible to reroute the intracellular trafficking of vesicles by changing the localisation of SNARE molecules, this approach can be used in in vivo biological studies to clarify the different control mechanisms regulating intracellular membrane trafficking. In addition we demonstrate peroxicretion of a diverse set of intracellular proteins. Therefore, we anticipate that the concept of peroxicretion may revolutionize the production of intracellular proteins from fungi and other microbial cells, as well as from mammalian cells.

    Robotic Versus Open Hepatic Arterial Infusion Pump Placement for Unresectable Intrahepatic Cholangiocarcinoma

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    BACKGROUND: Hepatic arterial infusion pump (HAIP) chemotherapy is an effective treatment for patients with unresectable intrahepatic cholangiocarcinoma (iCCA). HAIP chemotherapy requires a catheter inserted in the gastroduodenal artery and a subcutaneous pump. The catheter can be placed using an open or robotic approach. OBJECTIVE: This study aimed to compare perioperative outcomes of robotic versus open HAIP placement in patients with unresectable iCCA. METHODS: We analyzed patients with unresectable iCCA included in the PUMP-II trial from January 2020 to September 2022 undergoing robotic or open HAIP placement at Amsterdam UMC, Erasmus MC, and UMC Utrecht. The primary outcome was time to functional recovery (TTFR). RESULTS: In total, 22 robotic and 28 open HAIP placements were performed. The median TTFR was 2 days after robotic placement versus 5 days after open HAIP placement (p < 0.001). One patient (4.5%) in the robotic group underwent a conversion to open because of a large bulky tumor leaning on the hilum immobilizing the liver. Postoperative complications were similar-36% (8/22) after robotic placement versus 39% (11/28) after open placement (p = 1.000). The median length of hospital stay was shorter in the robotic group-3 versus 5 days (p < 0.001). All 22 robotic patients initiated HAIP chemotherapy post-surgery, i.e. 93% (26/28) in the open group (p = 0.497). The median time to start HAIP chemotherapy was 14 versus 18 days (p = 0.153). CONCLUSION: Robotic HAIP placement in patients with unresectable iCCA is a safe and effective procedure and is associated with a significantly shorter TTFR and hospital stay than open HAIP placement
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