The Experts below are selected from a list of 156279 Experts worldwide ranked by ideXlab platform
Sd Blacksell - One of the best experts on this subject based on the ideXlab platform.
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laboratory acquired scrub typhus and murine typhus infections the argument for a risk based approach to biosafety requirements for orientia tsutsugamushi and rickettsia typhi laboratory activities
Clinical Infectious Diseases, 2019Co-Authors: Sd Blacksell, Matthew T Robinson, Paul N Newton, Nicholas P J DayAbstract:This study examined the literature on laboratory-acquired infections (LAIs) associated with scrub typhus (Orientia tsutsugamushi) and murine typhus (Rickettsia typhi) research to provide an evidence base for biosafety and biocontainment. Scrub typhus LAIs were documented in 25 individuals, from 1931 to 2000 with 8 (32%) deaths during the preantibiotic era. There were 35 murine typhus LAI reports and no deaths. Results indicated that the highest-risk activities were working with infectious laboratory animals involving significant aerosol exposures, accidental self-inoculation, or bite-related infections. A risk-based biosafety approach for in vitro and in Vivo Culture of O. tsutsugamushi and R. typhi would require that only high-risk activities (animal work or large Culture volumes) be performed in high-containment biosafety level (BSL) 3 laboratories. We argue that relatively low-risk activities including inoculation of cell Cultures or the early stages of in vitro growth using low volumes/low concentrations of infectious materials can be performed safely in BSL-2 laboratories within a biological safety cabinet.
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Laboratory-acquired scrub typhus and murine typhus infections: The argument for risk-based approach to biosafety requirements for Orientia tsutsugamushi and Rickettsia typhi laboratory activities
'Oxford University Press (OUP)', 2018Co-Authors: Sd Blacksell, Mt Robinson, Pn Newton, Day NpjAbstract:This study examined the literature on laboratory-acquired infections (LAIs) associated with scrub typhus (Orientia tsutsugamushi) and murine typhus (Rickettsia typhi) research to provide an evidence base for biosafety and biocontainment. Scrub typhus LAIs were documented in 25 individuals, from 1931-2000 with 8 (32%) deaths during the pre-antibiotic era. There were 35 murine typhus LAI reports and no deaths. Results indicated that highest risk activities were working with infectious laboratory animals involving significant aerosol exposures, accidental self-inoculation or bite related infections. A risk-based biosafety approach for in vitro and in Vivo Culture of O. tsutsugamushi and R. typhi would require only high-risk activities (animal work or large Culture volumes) be performed in high containment BSL3 laboratories. We argue that relatively low risk activities including inoculation of cell Cultures or the early stages of in vitro growth using low volumes/low concentrations of infectious materials can be performed safely in BSL2 laboratories within a biological safety cabinet
Nicholas P J Day - One of the best experts on this subject based on the ideXlab platform.
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laboratory acquired scrub typhus and murine typhus infections the argument for a risk based approach to biosafety requirements for orientia tsutsugamushi and rickettsia typhi laboratory activities
Clinical Infectious Diseases, 2019Co-Authors: Sd Blacksell, Matthew T Robinson, Paul N Newton, Nicholas P J DayAbstract:This study examined the literature on laboratory-acquired infections (LAIs) associated with scrub typhus (Orientia tsutsugamushi) and murine typhus (Rickettsia typhi) research to provide an evidence base for biosafety and biocontainment. Scrub typhus LAIs were documented in 25 individuals, from 1931 to 2000 with 8 (32%) deaths during the preantibiotic era. There were 35 murine typhus LAI reports and no deaths. Results indicated that the highest-risk activities were working with infectious laboratory animals involving significant aerosol exposures, accidental self-inoculation, or bite-related infections. A risk-based biosafety approach for in vitro and in Vivo Culture of O. tsutsugamushi and R. typhi would require that only high-risk activities (animal work or large Culture volumes) be performed in high-containment biosafety level (BSL) 3 laboratories. We argue that relatively low-risk activities including inoculation of cell Cultures or the early stages of in vitro growth using low volumes/low concentrations of infectious materials can be performed safely in BSL-2 laboratories within a biological safety cabinet.
Patrick Haentjens - One of the best experts on this subject based on the ideXlab platform.
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An in Vivo Culture system for human embryos using an encapsulation technology: a pilot study
Human Reproduction, 2009Co-Authors: Christophe Blockeel, P Mock, H. Niemann, Yvan Heyman, Nicolas Bouché, Christine Wrenzycki, Greta Verheyen, Ph. Le Goff, K. Hoffmann, Patrick HaentjensAbstract:BACKGROUND: Animal studies have demonstrated better embryo development in Vivo than in vitro. This pilot study tested the feasibility of using a novel in utero Culture system (IUCS) to obtain normal human fertilization and embryo development. METHODS: The IUCS device comprised a perforated silicone hollow tube. The study included 13 patients (
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an in Vivo Culture system for human embryos using an encapsulation technology a pilot study
Human Reproduction, 2008Co-Authors: Christophe Blockeel, P Mock, Ph Le Goff, Katharina Isabell Hoffmann, H. Niemann, Yvan Heyman, Nicolas Bouché, Christine Wrenzycki, Greta Verheyen, Patrick HaentjensAbstract:background: Animal studies have demonstrated better embryo development in Vivo than in vitro. This pilot study tested the feasibility of using a novel in utero Culture system (IUCS) to obtain normal human fertilization and embryo development. methods: The IUCS device comprised a perforated silicone hollow tube. The study included 13 patients (,36 years) undergoing a first intracytoplasmic sperm injection (ICSI) treatment and 167 metaphase II oocytes in three groups. in Group 1, 1–2 h after ICSI, sibling oocytes were assigned to IUCS or conventional in vitro Culture. The device was retrieved on Day 1, and all zygotes were Cultured in vitro till Day 5. in Group 2, fertilized oocytes were assigned on Day 1, embryos retrieved on Day 3 and all embryos Cultured till Day 5. in Group 3, after Day 0 assignment, embryos were retrieved on Day 3 for blastomere biopsy and fluorescence in situ hybridization (FISH) and Cultured until Day 5. The highest quality blastocysts were transferred on Day 5. results: Fertilization and embryo development were comparable in the in vitro and IUCS arms, with a tendency towards better embryo quality in the IUCS. FISH analysis in Group 3 revealed more normal embryos using the IUCS (P ¼ 0.049). Three clinical pregnancies and live births were obtained: two from the IUCS arm and one from the in vitro arm. conclusions: Our pilot study shows that this new IUCS appears to be feasible and safe, supporting normal fertilization, embryo development and normal chromosomal segregation. Furthermore, live births are possible after the transient presence of a silicone device in the uterus. Clinicaltrials.gov: NCT00480103.
Jason A Burdick - One of the best experts on this subject based on the ideXlab platform.
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influence of three dimensional hyaluronic acid microenvironments on mesenchymal stem cell chondrogenesis
Tissue Engineering Part A, 2009Co-Authors: Cindy Chung, Jason A BurdickAbstract:Mesenchymal stem cells (MSCs) are multipotent progenitor cells whose plasticity and self-renewal capacity have generated significant interest for applications in tissue engineering. The objective of this study was to investigate MSC chondrogenesis in photo-cross-linked hyaluronic acid (HA) hydrogels. Because HA is a native component of cartilage, and MSCs may interact with HA via cell surface receptors, these hydrogels could influence stem cell differentiation. in vitro and in Vivo Cultures of MSC-laden HA hydrogels permitted chondrogenesis, measured by the early gene expression and production of cartilage-specific matrix proteins. For in Vivo Culture, MSCs were encapsulated with and without transforming growth factor beta-3 (TGF-β3) or pre-Cultured for 2 weeks in chondrogenic medium before implantation. Up-regulation of type II collagen, aggrecan, and sox 9 was observed for all groups over MSCs at the time of encapsulation, and the addition of TGF-β3 further enhanced the expression of these genes. To ass...
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influence of three dimensional hyaluronic acid microenvironments on mesenchymal stem cell chondrogenesis
Tissue Engineering Part A, 2009Co-Authors: Cindy K Chung, Jason A BurdickAbstract:Mesenchymal stem cells (MSCs) are multipotent progenitor cells whose plasticity and self-renewal capacity have generated significant interest for applications in tissue engineering. The objective of this study was to investigate MSC chondrogenesis in photo-cross-linked hyaluronic acid (HA) hydrogels. Because HA is a native component of cartilage, and MSCs may interact with HA via cell surface receptors, these hydrogels could influence stem cell differentiation. in vitro and in Vivo Cultures of MSC-laden HA hydrogels permitted chondrogenesis, measured by the early gene expression and production of cartilage-specific matrix proteins. For in Vivo Culture, MSCs were encapsulated with and without transforming growth factor beta-3 (TGF-beta3) or pre-Cultured for 2 weeks in chondrogenic medium before implantation. Up-regulation of type II collagen, aggrecan, and sox 9 was observed for all groups over MSCs at the time of encapsulation, and the addition of TGF-beta3 further enhanced the expression of these genes. To assess the influence of scaffold chemistry on chondrogenesis, HA hydrogels were compared with relatively inert poly(ethylene glycol) (PEG) hydrogels and showed enhanced expression of cartilage-specific markers. Differences between HA and PEG hydrogels in Vivo were most noticeable for MSCs and polymer alone, indicating that hydrogel chemistry influences the commitment of MSCs to undergo chondrogenesis (e.g., approximately 43-fold up-regulation of type II collagen of MSCs in HA over PEG hydrogels). Although this study investigated only early markers of tissue regeneration, these results emphasize the importance of material cues in MSC differentiation microenvironments, potentially through interactions between scaffold materials and cell surface receptors.
Julian Kim - One of the best experts on this subject based on the ideXlab platform.
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Requirement of innate Immunity in Tumor-Bearing Mice Cured by Adoptive Immunotherapy Using Tumor-Draining Lymph Nodes
2020Co-Authors: John B Ammori, Khaled Hamzeh, Hallie Graor, Julian KimAbstract:Background. The purpose of this study was to determine the cellular effectors of both the adoptively transferred cells and the tumor-bearing host that participate in the antitumor response to adoptive immunotherapy using Culture-activated tumor-draining lymph nodes (TDLNs). Methods. TDLNs harvested from mice with 4T1 carcinoma cells were fractionated to derive the L-selectin low subpopulation and activated ex Vivo prior to in vitro cytokine release assays and adoptive transfer into BALB/c mice bearing 3-day established subcutaneous tumors. Tumor-bearing recipients were SCID (lacking T, B, and NK cells), Rag2 deficient (lacking T and B cells), and wild-type BALB/c mice. Results. Culture-activated L-selectin low 4T1 TDLN from BALB/c mice secreted significant levels of interferon-gamma in response to 4T1 but not control tumor cells in vitro. CD4 cells within the adoptively transferred effector cell population contributed significantly to the antitumor effect in Vivo. Culture-activated L-selectin low TDLNs from BALB/c wild-type mice were able to cure Rag2 deficient but not SCID mice bearing 4T1 subcutaneous tumors, suggesting a requirement of NK cells within the innate immune system of the tumor-bearing host during the antitumor response. Conclusions. These results identify the cellular effectors involved in tumor regression following adoptive transfer and demonstrate the requirement for intact innate immunity within the tumor-bearing host
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requirement of innate immunity in tumor bearing mice cured by adoptive immunotherapy using tumor draining lymph nodes
Clinical & Developmental Immunology, 2015Co-Authors: John B Ammori, Khaled Hamzeh, Hallie Graor, Julian KimAbstract:Background. The purpose of this study was to determine the cellular effectors of both the adoptively transferred cells and the tumor-bearing host that participate in the antitumor response to adoptive immunotherapy using Culture-activated tumor-draining lymph nodes (TDLNs). Methods. TDLNs harvested from mice with 4T1 carcinoma cells were fractionated to derive the L- subpopulation and activated ex Vivo prior to in vitro cytokine release assays and adoptive transfer into BALB/c mice bearing 3-day established subcutaneous tumors. Tumor-bearing recipients were SCID (lacking T, B, and NK cells), Rag2 deficient (lacking T and B cells), and wild-type BALB/c mice. Results. Culture-activated L- 4T1 TDLN from BALB/c mice secreted significant levels of interferon-gamma in response to 4T1 but not control tumor cells in vitro. CD4 cells within the adoptively transferred effector cell population contributed significantly to the antitumor effect in Vivo. Culture-activated L- TDLNs from BALB/c wild-type mice were able to cure Rag2 deficient but not SCID mice bearing 4T1 subcutaneous tumors, suggesting a requirement of NK cells within the innate immune system of the tumor-bearing host during the antitumor response. Conclusions. These results identify the cellular effectors involved in tumor regression following adoptive transfer and demonstrate the requirement for intact innate immunity within the tumor-bearing host.
