39 results on '"Hellström, Mats"'
Search Results
2. Large-scale reconstitution of a retina-to-brain pathway in adult rats using gene therapy and bridging grafts: An anatomical and behavioral analysis.
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You, Si-Wei, Hellström, Mats, Pollett, Margaret A., LeVaillant, Chrisna, Moses, Colette, Rigby, Paul J., Penrose, Marissa, Rodger, Jennifer, and Harvey, Alan R.
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NERVE grafting , *CENTRAL nervous system diseases , *RETINAL ganglion cells , *LABORATORY rats , *GENE therapy ,SCIATIC nerve surgery - Abstract
Peripheral nerve (PN) grafts can be used to bridge tissue defects in the CNS. Using a PN-to-optic nerve (ON) graft model, we combined gene therapy with pharmacotherapy to promote the long-distance regeneration of injured adult retinal ganglion cells (RGCs). Autologous sciatic nerve was sutured onto the transected ON and the distal end immediately inserted into contralateral superior colliculus (SC). Control rats received intraocular injections of saline or adeno-associated virus (AAV) encoding GFP. In experimental groups, three bi- cis tronic AAV vectors encoding ciliary neurotrophic factor (CNTF) were injected into different regions of the grafted eye. Each vector encoded a different fluorescent reporter to assess retinotopic order in the regenerate projection. To encourage sprouting/synaptogenesis, after 6 weeks some AAV–CNTF injected rats received an intravitreal injection of recombinant brain-derived neurotrophic factor (rBDNF) or AAV–BDNF. Four months after surgery, cholera toxin B was used to visualize regenerate RGC axons. RGC viability and axonal regrowth into SC were significantly greater in AAV–CNTF groups. In some cases, near the insertion site, regenerate axonal density resembled retinal terminal densities seen in normal SC. Complex arbors were seen in superficial but not deep SC layers and many terminals were immunopositive for presynaptic proteins vGlut2 and SV2. There was improvement in visual function via the grafted eye with significantly greater pupillary constriction in both AAV–CNTF + BDNF groups. In both control and AAV–CNTF + rBDNF groups the extent of light avoidance correlated with the maximal distance of axonal penetration into superficial SC. Despite the robust regrowth of RGC axons back into the SC, axons originating from different parts of the retina were intermixed at the PN graft/host SC interface, indicating that there remained a lack of order in this extensive regenerate projection. [ABSTRACT FROM AUTHOR]
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- 2016
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3. Endothelial cell spheroids as a versatile tool to study angiogenesis in vitro.
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Heiss, Maximilian, Hellström, Mats, Kalén, Mattias, May, Tobias, Weber, Holger, Hecker, Markus, Augustin, Hellmut G., and Korff, Thomas
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Given the need for robust and cost‐efficient in vitro models to study angiogenesis and reproducibly analyze potential pro‐ and antiangiogenic compounds in preclinical studies, we developed a 3‐dimensional in vitro angiogenesis assay that is based on collagen gel‐embedded, size‐defined spheroids generated from cultured human umbilical vein endothelial cells (HUVECs). Despite its wide distribution, limitations, sensitivity, robustness, and improvements, the capacity of this assay for functional screening purposes has not been elucidated thus far. By using time‐lapse video microscopy, we show that tip cells lead the formation of capillary‐like and partially lumenized sprouts originating from the spheroids. Angiogenic sprouting from spheroids generated from 5 different primary cultured human endothelial cell types was induced by physiologic concentrations of vascular endothelial cell growth factor 165. Based on this assay system, we determined the capacity of 880 approved drugs to interfere with or boost angiogenic sprouting, thereby assessing their putative angiogenesis‐related side effects or novel applications. However, although this assay allowed for a rapid and reproducible determination of functional IC50 values of individual compounds, the sprouting results were partially affected by the HUVEC passage number and donor variability. To overcome this limitation, immortalized HUVECs (iHUVECs) showing a more homogenous response in terms of proliferation and sprouting over multiple population doublings were used in the course of this study. Collectively, the spheroid‐based angiogenesis assay provides a sensitive and versatile tool to study the impact of pro‐ and antiangiogenic determinants on multiple steps of the angiogenic cascade. It is compatible with different endothelial cell types and allows use of iHUVECs to improve its overall robustness.—Heiss, M., Hellström, M., Kalén, M., May, T., Weber, H., Hecker, M., Augustin, H. G., Korff, T. Endothelial cell spheroids as a versatile tool to study angiogenesis in vitro. FASEB J. 29, 3076‐3084 (2015). www.fasebj.org [ABSTRACT FROM AUTHOR]
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- 2015
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4. Luminal solutions protect mucosal barrier during extended preservation.
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Oltean, Mihai, Hellström, Mats, Ciuce, Catalin, Zhu, Changlian, and Casselbrant, Anna
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AMINO acid analysis , *POLYETHYLENE glycol , *GLUTAMINE , *MUCOUS membranes , *TIGHT junctions - Abstract
Background Mucosal barrier injury during intestinal preservation (IP) and transplantation favors life-threatening infections. Luminal delivery of solutions containing amino acids or polyethylene glycols (PEGs) may improve preservation results and reduce this injury. We tested if solutions containing glutamine and PEG influence the mucosal injury. Materials and methods Rat intestines were perfused and stored in Viaspan-University of Wisconsin solution. Before IP, a PEG 3350 solution was introduced intraluminally alone (group 1) or supplemented with 40 mmol/L L-glutamine (group 2). Controls underwent vascular flush alone (group 3). Preservation injury was evaluated after 8, 14, and 24 h by histology and goblet cell count. Tight-junction proteins zonula occludens-1, claudin-3, claudin-4, and caveolin-1 were studied by immunofluorescence. Maltase and caspase-3 activity were also analyzed. Results Group 1 showed mild edema at 8 h and mucosal disruption by 24 h; these features were greatly improved in group 2 where continuous mucosa was found after 24 h of IP. Intestines in group 3 did worse at all time points with subepithelial edema (Park/Chiu grade 3) and marked goblet cell depletion; caspase-3 activity was lowest in group 2. Tight-junction proteins varied continuously during IP; zonula occludens-1 expression and colocalization with claudins decreased significantly in group 3 but not in other groups. Claudin-3 was distinctly localized in the membrane, but stained diffuse, cytoplasmic at later time-points. Claudin-4 changed to a cytoplasmic granular pattern. No caveolin-1 colocalization was observed. Conclusions Luminal PEG and glutamine delay epithelial breakdown and preserve several important mucosal features during extended IP. [ABSTRACT FROM AUTHOR]
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- 2015
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5. Cyclic AMP and the regeneration of retinal ganglion cell axons.
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Hellström, Mats and Harvey, Alan R.
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CYCLIC adenylic acid , *RETINAL ganglion cells , *AXONS , *REGENERATION (Biology) , *TISSUE remodeling , *CELLULAR signal transduction , *CYTOKINES - Abstract
In this paper we present a brief review of studies that have reported therapeutic benefits of elevated cAMP on plasticity and regeneration after injury to the central nervous system (CNS). We also provide new data on the cellular mechanisms by which elevation of cyclic adenosine monophosphate (cAMP) promotes cytokine driven regeneration of adult CNS axons, using the visual system as the experimental model. cAMP is a second messenger for many intracellular signalling pathways. Elevation of cAMP in the eye by intravitreal injection of the cell permeant analogue (8-(4-chlorophenylthio)-adenosine-3′,5′-cyclic monophosphate; CPT-cAMP), when added to recombinant ciliary neurotrophic factor (rCNTF), significantly enhances rCNTF-induced regeneration of adult rat retinal ganglion cell (RGC) axons into peripheral nerve (PN) grafted onto transected optic nerve. This effect is mediated to some extent by protein kinase A (PKA) signalling, but CPT-cAMP also acts via PI3K/Akt signalling to reduce suppressor of cytokine signalling protein 3 (SOCS3) activity in RGCs. Another target for cAMP is the exchange protein activated by cAMP (Epac), which can also mediate cAMP-induced axonal growth. Here we describe some novel results and discuss to what extent the pro-regenerative effects of CPT-cAMP on adult RGCs are mediated via Epac as well as via PKA-dependent pathways. We used the established PN–optic nerve graft model and quantified the survival and regenerative growth of adult rat RGCs after intravitreal injection of rCNTF in combination with a selective activator of PKA and/or a specific activator of Epac. Viable RGCs were identified by βIII-tubulin immunohistochemistry and regenerating RGCs retrogradely labelled and quantified after an injection of fluorogold into the distal end of the PN grafts, 4 weeks post-transplantation. The specific agonists of either PKA or Epac were both effective in enhancing the effects of rCNTF on RGC axonal regeneration, but interestingly, injections that combined rCNTF with both agonists were significantly less effective. The results are discussed in relation to previous CPT-cAMP studies on RGCs, and we also consider the need to modulate cAMP levels in order to obtain the most functionally effective regenerative response after CNS trauma. This article is part of a directed issue entitled: Regenerative Medicine: the challenge of translation. [ABSTRACT FROM AUTHOR]
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- 2014
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6. Notch as a hub for signaling in angiogenesis.
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Benedito, Rui and Hellström, Mats
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- 2013
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7. Bioengineering trends in female reproduction: a systematic review.
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Francés-Herrero, Emilio, Lopez, Rosalba, Hellström, Mats, Miguel-Gómez, Lucía de, Herraiz, Sonia, Brännström, Mats, Pellicer, Antonio, Cervelló, Irene, and de Miguel-Gómez, Lucía
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RESEARCH funding , *FEMALE reproductive organs , *BIOMEDICAL engineering , *SYSTEMATIC reviews , *HUMAN reproduction , *ANIMAL experimentation , *FETAL development , *UTERUS - Abstract
Background: To provide the optimal milieu for implantation and fetal development, the female reproductive system must orchestrate uterine dynamics with the appropriate hormones produced by the ovaries. Mature oocytes may be fertilized in the fallopian tubes, and the resulting zygote is transported toward the uterus, where it can implant and continue developing. The cervix acts as a physical barrier to protect the fetus throughout pregnancy, and the vagina acts as a birth canal (involving uterine and cervix mechanisms) and facilitates copulation. Fertility can be compromised by pathologies that affect any of these organs or processes, and therefore, being able to accurately model them or restore their function is of paramount importance in applied and translational research. However, innate differences in human and animal model reproductive tracts, and the static nature of 2D cell/tissue culture techniques, necessitate continued research and development of dynamic and more complex in vitro platforms, ex vivo approaches and in vivo therapies to study and support reproductive biology. To meet this need, bioengineering is propelling the research on female reproduction into a new dimension through a wide range of potential applications and preclinical models, and the burgeoning number and variety of studies makes for a rapidly changing state of the field.Objective and Rationale: This review aims to summarize the mounting evidence on bioengineering strategies, platforms and therapies currently available and under development in the context of female reproductive medicine, in order to further understand female reproductive biology and provide new options for fertility restoration. Specifically, techniques used in, or for, the uterus (endometrium and myometrium), ovary, fallopian tubes, cervix and vagina will be discussed.Search Methods: A systematic search of full-text articles available in PubMed and Embase databases was conducted to identify relevant studies published between January 2000 and September 2021. The search terms included: bioengineering, reproduction, artificial, biomaterial, microfluidic, bioprinting, organoid, hydrogel, scaffold, uterus, endometrium, ovary, fallopian tubes, oviduct, cervix, vagina, endometriosis, adenomyosis, uterine fibroids, chlamydia, Asherman's syndrome, intrauterine adhesions, uterine polyps, polycystic ovary syndrome and primary ovarian insufficiency. Additional studies were identified by manually searching the references of the selected articles and of complementary reviews. Eligibility criteria included original, rigorous and accessible peer-reviewed work, published in English, on female reproductive bioengineering techniques in preclinical (in vitro/in vivo/ex vivo) and/or clinical testing phases.Outcomes: Out of the 10 390 records identified, 312 studies were included for systematic review. Owing to inconsistencies in the study measurements and designs, the findings were assessed qualitatively rather than by meta-analysis. Hydrogels and scaffolds were commonly applied in various bioengineering-related studies of the female reproductive tract. Emerging technologies, such as organoids and bioprinting, offered personalized diagnoses and alternative treatment options, respectively. Promising microfluidic systems combining various bioengineering approaches have also shown translational value.Wider Implications: The complexity of the molecular, endocrine and tissue-level interactions regulating female reproduction present challenges for bioengineering approaches to replace female reproductive organs. However, interdisciplinary work is providing valuable insight into the physicochemical properties necessary for reproductive biological processes to occur. Defining the landscape of reproductive bioengineering technologies currently available and under development for women can provide alternative models for toxicology/drug testing, ex vivo fertility options, clinical therapies and a basis for future organ regeneration studies. [ABSTRACT FROM AUTHOR]- Published
- 2022
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8. VEGF and Notch Signaling.
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Hellström, Mats, Phng, Li-Kun, and Gerhardt, Holger
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- 2007
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9. Dll4 signalling through Notch1 regulates formation of tip cells during angiogenesis.
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Hellström, Mats, Phng, Li-Kun, Hofmann, Jennifer J., Wallgard, Elisabet, Coultas, Leigh, Lindblom, Per, Alva, Jackelyn, Nilsson, Ann-Katrin, Karlsson, Linda, Gaiano, Nicholas, Yoon, Keejung, Rossant, Janet, Iruela-Arispe, M. Luisa, Kalén, Mattias, Gerhardt, Holger, and Betsholtz, Christer
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NOTCH genes , *NEOVASCULARIZATION , *VASCULAR endothelial growth factors , *ALZHEIMER'S disease , *VASCULAR endothelium , *DEVELOPMENTAL cytology - Abstract
In sprouting angiogenesis, specialized endothelial tip cells lead the outgrowth of blood-vessel sprouts towards gradients of vascular endothelial growth factor (VEGF)-A. VEGF-A is also essential for the induction of endothelial tip cells, but it is not known how single tip cells are selected to lead each vessel sprout, and how tip-cell numbers are determined. Here we present evidence that delta-like 4 (Dll4)–Notch1 signalling regulates the formation of appropriate numbers of tip cells to control vessel sprouting and branching in the mouse retina. We show that inhibition of Notch signalling using γ-secretase inhibitors, genetic inactivation of one allele of the endothelial Notch ligand Dll4, or endothelial-specific genetic deletion of Notch1, all promote increased numbers of tip cells. Conversely, activation of Notch by a soluble jagged1 peptide leads to fewer tip cells and vessel branches. Dll4 and reporters of Notch signalling are distributed in a mosaic pattern among endothelial cells of actively sprouting retinal vessels. At this location, Notch1-deleted endothelial cells preferentially assume tip-cell characteristics. Together, our results suggest that Dll4–Notch1 signalling between the endothelial cells within the angiogenic sprout serves to restrict tip-cell formation in response to VEGF, thereby establishing the adequate ratio between tip and stalk cells required for correct sprouting and branching patterns. This model offers an explanation for the dose-dependency and haploinsufficiency of the Dll4 gene, and indicates that modulators of Dll4 or Notch signalling, such as γ-secretase inhibitors developed for Alzheimer’s disease, might find usage as pharmacological regulators of angiogenesis. [ABSTRACT FROM AUTHOR]
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- 2007
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10. Neutropenic complications in the PANTHER phase III study of adjuvant tailored dose-dense chemotherapy in early breast cancer.
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Papakonstantinou, Antroula, Hedayati, Elham, Hellström, Mats, Johansson, Hemming, Gnant, Michael, Steger, Günther, Greil, Richard, Untch, Michael, Moebus, Volker, Loibl, Sibylle, Foukakis, Theodoros, Bergh, Jonas, and Matikas, Alexios
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BREAST tumors , *COMBINED modality therapy , *CONFIDENCE intervals , *DOSE-effect relationship in pharmacology , *FEBRILE neutropenia , *GRANULOCYTE-colony stimulating factor , *FLUOROURACIL , *LEUCOPENIA , *RESEARCH , *SURVIVAL , *TUMOR classification , *DOCETAXEL , *RANDOMIZED controlled trials , *CYCLOPHOSPHAMIDE , *EPIRUBICIN , *ODDS ratio , *DISEASE risk factors - Abstract
Introduction: Myelosuppresion is a common side effect of chemotherapy and granulocyte-colony stimulating factor (G-CSF) is often used to reduce the risk of neutropenic events. The purpose of this exploratory analysis was to investigate neutropenic complications in the phase III PANTHER trial of standard 3-weekly chemotherapy with 5-fluorouracil, epirubicin and cyclophosphamide plus docetaxel (FEC/D) versus bi-weekly tailored dose-dense EC/D adjuvant chemotherapy in breast cancer. Patients and methods: Febrile neutropenia, neutropenic infection and infection grade 3–4 according to CTC AE 3.0, were explored in relation to G-CSF use. Per cycle analysis was performed concerning dose reduction and dose delays in conjunction with G-CSF administration. Results: In the experimental group, 98.9% of patients received primary G-CSF support during EC and 97.4% during docetaxel, compared with 49.7% during FEC and 63.88% during docetaxel in the standard group. Overall, the use of G-CSF was associated with a lower risk for developing neutropenic events (OR 0.44, 95% CI 0.35–0.55, p <.001). Chemotherapy delays due to neutropenia and leukopenia were significantly decreased among patients that received G-CSF (OR 0.098, 95% CI 0.06–0.15 and OR 0.32, 95% CI 0.18–0.58, respectively). Discussion: In conclusion, G-CSF support reduces neutropenic events and permits increased relative dose intensity, which is essential for improved survival outcomes. [ABSTRACT FROM AUTHOR]
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- 2020
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11. Bioengineered uterine tissue supports pregnancy in a rat model.
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Hellström, Mats, Moreno-Moya, Juan M., Bandstein, Sara, Bom, Eva, Akouri, Randa R., Miyazaki, Kaoru, Maruyama, Tetsuo, and Brännström, Mats
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UTERUS , *TISSUE scaffolds , *GREEN fluorescent protein , *MESENCHYMAL stem cells , *DIMETHYL sulfoxide , *LABORATORY rats , *WOUNDS & injuries , *TRANSPLANTATION of organs, tissues, etc. , *RNA metabolism , *STEM cell transplantation , *ANIMAL experimentation , *CELL culture , *CONNECTIVE tissue cells , *CULTURE media (Biology) , *GENES , *GENETIC techniques , *GESTATIONAL age , *PROTEINS , *RATS , *RNA , *TISSUE engineering , *FETAL development , *PHYSIOLOGY - Abstract
Objective: To create a bioengineered uterine patch for uterine repair of a partially defect uterus.Design: Three different decellularized uterine scaffolds were recellularized in vitro with primary uterine cells and green fluorescent protein- (GPF-) labeled bone marrow-derived mesenchymal stem cells (GFP-MSCs). The patches were transplanted in vivo to investigate their tissue adaptation and supporting capacity during pregnancy.Setting: Research laboratory.Animal(s): Female Lewis rats (n = 9) as donors to generate whole-uterus scaffolds using three different protocols (n = 3 per protocol); Sprague Dawley rats (n = 40) for primary uterus cell isolation procedures (n = 10) and for transplantation/pregnancy studies (n = 30); and male Sprague Dawley rats (n = 12) for mating.Intervention(s): Decellularization was achieved by whole-uterus perfusion with buffered or nonbuffered Triton-X100 and dimethyl sulfoxide (DMSO; group P1/P2) or with sodium deoxycholate (group P3). Primary uterine cells and GFP-MSCs were used to develop uterine tissue constructs, which were grafted to uteri with partial tissue defects.Main Outcome Measure(s): Recellularization efficiency and graft quality were analyzed morphologically, immunohistochemically, and by real-time quantitative polymerase chain reaction (PCR). The location and number of fetuses were documented during pregnancy days 16-20.Result(s): Pregnancy and fetal development were normal in groups P1 and P2, with fetal development over patched areas. Group P3 showed significant reduction of fetal numbers, and embryos were not seen in the grafted area. Quantitative PCR and immunohistochemistry revealed uterus-like tissue in the patches, which had been further reconstructed by infiltrating host cells after transplantation.Conclusion(s): Primary uterine cells and MSCs can be used to reconstruct decellularized uterine tissue. The bioengineered patches made from triton-X100+DMSO-generated scaffolds were supportive during pregnancy. These protocols should be explored further to develop suitable grafting material to repair partially defect uteri and possibly to create a complete bioengineered uterus. [ABSTRACT FROM AUTHOR]- Published
- 2016
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12. Radiotherapy—Dose Escalated for Large Volume Primary Tumors—And Cetuximab with or without Induction Chemotherapy for HPV Associated Squamous Cell Carcinoma of the Head and Neck—A Randomized Phase II Trial.
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Mercke, Claes, Wickart-Johansson, Gun, Sjödin, Helena, Farrajota Neves da Silva, Pedro, Alexandersson von Döbeln, Gabriella, Margolin, Gregori, Jonmarker Jaraj, Sara, Carstens, Hanna, Berglund, Anders, Lax, Ingmar, Hellström, Mats, Hammarstedt-Nordenvall, Lalle, and Friesland, Signe
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THERAPEUTIC use of monoclonal antibodies , *THERAPEUTIC use of antineoplastic agents , *RESEARCH , *HEAD & neck cancer , *CANCER relapse , *DOSE-response relationship (Radiation) , *TREATMENT effectiveness , *CHEMORADIOTHERAPY , *RANDOMIZED controlled trials , *PAPILLOMAVIRUS diseases , *RADIATION doses , *RESEARCH funding , *STATISTICAL sampling , *PROGRESSION-free survival , *SALVAGE therapy , *SQUAMOUS cell carcinoma , *INDUCTION chemotherapy , *DISEASE risk factors , *DISEASE complications - Abstract
Simple Summary: Most patients with HPV associated squamous cell carcinoma of the head and neck, treated with chemoradiotherapy, CRT, for cure, and who succumb to their disease, do so because of distant metastases. Even if a local recurrence as first site of treatment failure is rather low in this disease, characterised as being radiosensitive, such failures are still a problem. In this randomized phase II study we aimed to exploit whether induction chemotherapy IC, with two cycles of Taxotere, Cisplatin and 5-FU, TPF, could improve progression -free survival, PFS, by diminishing the rate of distant failures, administered before CRT. To reduce risk of toxicity from cumulated doses of cisplatin, concurrent chemotherapy during RT was given with cetuximab. To improve local control and mitigate the negative impact of a large tumor volume, an escalated RT dose was prescribed for patients with such tumors. PFS was found to be similar in the two study arms. However, even if not statistically significant, there were twice as many patients with distant relapses in the group of patients who had not IC. Overall survival was high and local recurrence as first site of failure was low, in 4.6% of patients and was similar for T1/T2 and locally bulky T3/T4 tumors. An escalated RT dose might have mitigated the negative impact of a large tumor volume but for some patients even this intensified treatment was insufficient. With respect to patients' response to IC, 29% of the patients in this treatment arm could be identified to have no relapse whether locoregional or distant during the time of follow up. These data shed further light on the characteristics of this disease of importance for the planning of future studies. If induction chemotherapy with cisplatin could reliably help to select patients for de-escalated subsequent RT, cetuximab is considered a good candidate to be given concurrently with RT to diminish morbidity from cumulated doses of cisplatin. The role of escalated RT doses for selected patients with bulky T3 and T4 tumors, perhaps primarily for those who do not respond to IC should also be addressed in future studies. The leading cause of death for patients with HPV associated squamous cell carcinoma of the head and neck (SCCHN) after treatment with chemoradiotherapy (CRT) nowadays is peripheral metastasis. This study investigated whether induction chemotherapy (IC) could improve progression free survival (PFS) and impact on relapse pattern after CRT. Methods: Eligible patients in this multicenter, randomized, controlled, phase 2 trial had p16-positive locoregionally advanced SCCHN. Patients were randomized in a 1:1 ratio to either RT with cetuximab (arm B) versus the same regimen preceded by two cycles of taxotere/cisplatin/5-FU (arm A). The RT dose was escalated to 74.8 Gy for large volume primary tumors. Eligibility criteria included patients of 18–75 years, an ECOG performance status 0–1, and adequate organ functions. Results: From January 2011 to February 2016, 152 patients, all with oropharyngeal tumors were enrolled, 77 in arm A and 75 in arm B. Two patients, one in each group, withdrew their consent after randomization, leaving 150 patients for the ITT analysis. PFS at 2 years was 84.2% (95% CI 76.4–92.8) in arm A and 78.4% (95% CI 69.5–88.3) in arm B (HR 1.39, 95% CI 0.69–2.79, p = 0.40). At the time of analysis, there were 26 disease failures, 9 in arm A and 17 in arm B. In arm A, 3 patients had local, 2 regional, and 4 distant relapses as first sites of recurrence, and in arm B, 4, 4, and 9 relapses in corresponding sites. Eight out of 26 patients with disease progression had salvage therapy and 7 were alive NED (no evidence of disease), at 2 years. Locoregional control was 96% in arm A and 97.3% in arm B and OS 93% and 90.5%, respectively. Local failure as first site of recurrence was low, in 4.6% of patients and was similar for T1/T2 and T3/T4 tumors (n.s). Nevertheless, out of 7 patients with primary local failures, 4 were treated with the escalated RT dose. Toxicity was low and similar in the treatment arms. There was one fatal event in arm A where the combined effects of the drugs used in chemotherapy and cetuximab could not be ruled out. Conclusions: PFS, locoregional control and toxicity did not differ between the two arms, OS was high, and there were few local relapses. In arm B, more than twice as many patients had distant metastasis as the first site of relapse compared to arm A. The response to IC was found to define 29% of patients in arm A who did not have a tumor relapse during follow-up. An escalated dose of 74.8 Gy could mitigate the negative impact of large tumor volume but for some patients, even this intensified treatment was insufficient. [ABSTRACT FROM AUTHOR]
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- 2023
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13. A sequential assessment of the preservation injury in porcine intestines.
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Oltean, Mihai, Jiga, Lucian, Hellström, Mats, Söfteland, John, Papurica, Marius, Hoinoiu, Teodora, Ionac, Mihai, and Casselbrant, Anna
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INTESTINE transplantation , *REPERFUSION injury , *SWINE , *SWINE physiology , *EXFOLIATIVE cytology , *TIGHT junctions , *BIOPSY , *WOUNDS & injuries - Abstract
Background Clinical and experimental evidence strongly suggest that ischemia–reperfusion injury after intestinal transplantation has deleterious short- and long-term effects and finding means to reduce ischemia–reperfusion injury is a major research area. The anatomical and physiological similarities between the human and porcine digestive tract favor its use as a preclinical model for translational research. Intriguingly, no systematic appraisal of the development of the intestinal preservation injury in pigs is available. Materials and methods Intestinal procurement was performed in nine pigs using histidine-tryptophan-ketoglutarate solution as preservation fluid. Ileal biopsies were obtained after 8, 14, and 24 h of static cold storage (SCS), and the preservation injury was assessed morphologically (Chiu score) as well as on the molecular level. Tight junction (zonula occludens, claudin-3 and 4, tricellulin, and occludin) and adherens junctions (E-cadherin) proteins were studied using immunofluorescence and Western blot. Results Eight hours of SCS induced minimal mucosal changes (Chiu grade 1) that advanced to significant subepithelial edema (Chiu grade 3) after 24 h; progressive Goblet cell depletion was also noted. Apoptosis (studied by cleaved caspase-3 staining significantly increased after 24 h of SCS. Significant molecular changes with decreasing expression of zonula occludens, tricellulin, and occludin were evident already after 8 h of SCS and continuously worsened. Claudin-3 and Claudin-4 and E-cadherin expression remained relatively unaltered during SCS. Conclusions Important molecular alterations precede histologic changes during SCS of the porcine intestine and may be used as more sensitive injury markers than histologic changes in intestinal ischemia and transplantation. [ABSTRACT FROM AUTHOR]
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- 2017
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14. Mucosal Recovery after Intestinal Transplantation in the Rat: A Sequential Histological and Molecular Assessment.
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Bagge, Jasmine, Padma, Arvind Manikantan, Casselbrant, Anna, Hellström, Mats, and Oltean, Mihai
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INTESTINES , *INTESTINAL ischemia , *TIGHT junctions , *SPRAGUE Dawley rats , *COLD storage - Abstract
Introduction: Intestinal cold ischemia and subsequent reperfusion during transplantation result in various degrees of mucosal injury ranging from mild edema to extensive mucosal loss. Mucosal barrier impairment favors bacterial translocation and fluid loss and raises nutritional challenges. The injured intestine also releases proinflammatory mediators and upregulates various epitopes toward an inflammatory phenotype. We studied the process of mucosal injury and repair during the early period after intestinal transplantation from a histological and molecular standpoint. Materials and Methods: Adult Sprague-Dawley rats were used as donors and recipients. Donor intestines were perfused and stored in saline for 3 h, then transplanted heterotopically using microvascular anastomoses. Intestinal graft segments were obtained after 20 min, 6 h, 12 h, and 24 h after reperfusion. Histology studies (goblet cell count, morphometry), immunofluorescence, and western blot for several tight junction proteins, apoptosis, and inflammation-related proteins were performed. Results: Cold storage led to extensive epithelial detachment, whereas reperfusion resulted in extensive villus loss (about 60% of the initial length), and goblet cell numbers were drastically reduced. Over the first 24 h, gradual morphologic and molecular recovery was noted, although several molecular alterations persisted (increased apoptosis and inflammation, altered expression of several tight junctions). Conclusions: The current data suggest that a near-complete morphologic recovery from a moderate mucosal injury occurs within the first 24 h after intestinal transplantation. However, several molecular alterations persist and need to be considered when designing intestinal transplant experiments and choosing sampling and endpoints. [ABSTRACT FROM AUTHOR]
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- 2023
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15. The microsurgical training programme in Gothenburg, Sweden: early experiences.
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Oltean, Mihai, Sassu, Paolo, Hellström, Mats, Axelsson, Peter, Ewaldsson, Lars, Nilsson, Anders G., and Axelsson, Michael
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MICROSURGERY , *TRAINING , *SURGERY , *LEARNING - Abstract
Objective:Microsurgical techniques are increasingly used in routine surgical practice as well as in biomedical research. The training opportunities at standardised training courses are limited, and no microsurgical training facility orprogrammeexisted in Scandinavia before 2013. Methods:A microsurgery laboratory was set up and two different courses were started, aiming separately at biomedical researchers and surgeons. The course for biomedical researchers teaches basic microsurgical skills such as vessel isolation, cannulation, and arterial microvascular suture under magnification. The more advanced course for surgeons focuses on various techniques of microvascular and nerve anastomosis. Both courses use a combination of theory and practice, with emphasis on the practical part, the course for surgeons also includes clinically relevant information. Results:Twelve 5-day courses using both non-living models and exercises on laboratory animals have been conducted and attended by 49 researchers and 44 surgeons. The organisation and the programme of the training courses as well as ‘The 4E concept’ behind the course (educational curriculum, equipment, ergonomy, and evaluation) are further detailed. Conclusions:We have successfully established the first training laboratory and series of microsurgical training courses in Scandinavia at two different levels. The experience from the first 12 courses shows the need for this type of structured training, and confirms that the microsurgical education curriculums needs to be adapted to participants’ prerequisites and expectations, and various difficulty levels should be considered. [ABSTRACT FROM AUTHOR]
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- 2017
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16. Mesenchymal stem cells establish a pro-regenerative immune milieu after decellularized rat uterus tissue transplantation.
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Sehic, Edina, Thorén, Emy, Gudmundsdottir, Ingigerdur, Oltean, Mihai, Brännström, Mats, and Hellström, Mats
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MESENCHYMAL stem cells , *TRANSPLANTATION of organs, tissues, etc. , *REGENERATION (Biology) , *CYTOTOXIC T cells , *UTERUS , *MACROPHAGES , *TISSUE scaffolds , *T cells - Abstract
Decellularized tissue is generally considered immune privileged after transplantation and is an attractive scaffold type for tissue regeneration, including applications for infertility treatment. However, the immune response following transplantation of decellularized tissue is insufficiently studied, in particular after they have been recellularized with mesenchymal stem cells (MSCs). Therefore, we replaced a large uterus segment with a bioengineered graft developed from decellularized uterus tissue and analyzed the immune response during the first 4 months in acellular or MSCs-recellularized scaffolds in the rat. Immunohistochemistry-stained infiltrating immune cells and plasma levels for 16 cytokines and chemokines were quantified. Results revealed that MSCs created an advantageous microenvironment by increasing anti-inflammatory interleukin 10 levels, and increasing the population of FOXP3+ TRegs and CD163+ M2 macrophages, and by reducing the CD8+ cytotoxic T cell population. Hence, MSCs should be considered an immunotherapeutic cell source with the ability to dictate regeneration success after decellularized tissue transplantation. [ABSTRACT FROM AUTHOR]
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- 2022
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17. Low‐grade diffusely infiltrative tumour (LGDIT), SMARCB1‐mutant: A clinical and histopathological distinct entity showing epigenetic similarity with ATRT‐MYC.
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Hasselblatt, Martin, Thomas, Christian, Federico, Aniello, Bens, Susanne, Hellström, Mats, Casar‐Borota, Olivera, Kordes, Uwe, Neumann, Julia E., Dottermusch, Matthias, Rodriguez, Fausto J., Lo, Andrea C., Cheng, Sylvia, Hendson, Glenda, Hukin, Juliette, Hartmann, Christian, Koch, Arend, Capper, David, Siebert, Reiner, Paulus, Werner, and Nemes, Karolina
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EPIGENETICS , *TUMORS , *HISTOPATHOLOGY , *CYTOTOXIC T cells - Published
- 2022
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18. Seven days ex vivo perfusion of whole ewe ovaries with follicular maturation and oocyte retrieval: towards the development of an alternative fertility preservation method.
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Tsiartas, Panagiotis, Mateoiu, Claudia, Deshmukh, Meghshree, Banerjee, Debashish, Padma, Arvind M., Milenkovic, Milan, Gandolfi, Fulvio, Hellström, Mats, Patrizio, Pasquale, and Akouri, Randa
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FERTILITY preservation , *OOCYTE retrieval , *OVARIAN reserve , *OVARIES , *OVARIAN follicle , *EWES , *PERFUSION - Abstract
Fertility preservation methods for prepubertal women about to undergo gonadotoxic chemo and/or radiation therapy are limited. Therefore, the aim of this study was to investigate the feasibility to develop an alternative fertility preservation method based on an ex vivo perfusion platform for whole ewe ovaries. Thirteen ewe ovaries were divided into two groups (group 1 and 2) that were perfused in a bioreactor for up to 7 days. Group 1 (n = 3) were stimulated with human menopausal gonadotropin (hMG) administered in single daily dose, while group 2 (n = 10) were stimulated continuously for 24 h. The perfused ovaries in group 1 showed no significant differences in follicular density, sub-follicular morphology and oocyte quality after ischaemia and after ex vivo perfusion compared with non-perfused control ovaries. The perfused ovaries in group 2 showed a significant decrease in the follicular reserve and oocyte quality compared with the control group. In total, 16 GV-MI oocytes were retrieved from both groups. This study describes for the first time the ex vivo maintenance of viable follicles of ewe ovaries with oocyte integrity and the retrieval of oocytes after ex vivo hormonal perfusion with two different protocols for up to 7 days. [ABSTRACT FROM AUTHOR]
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- 2022
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19. Mesenchymal stem cells establish a pro-regenerative immune milieu after decellularized rat uterus tissue transplantation.
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Sehic, Edina, Thorén, Emy, Gudmundsdottir, Ingigerdur, Oltean, Mihai, Brännström, Mats, and Hellström, Mats
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MESENCHYMAL stem cells , *TRANSPLANTATION of organs, tissues, etc. , *REGENERATION (Biology) , *CYTOTOXIC T cells , *UTERUS , *TISSUE scaffolds , *MACROPHAGES , *T cells - Abstract
Decellularized tissue is generally considered immune privileged after transplantation and is an attractive scaffold type for tissue regeneration, including applications for infertility treatment. However, the immune response following transplantation of decellularized tissue is insufficiently studied, in particular after they have been recellularized with mesenchymal stem cells (MSCs). Therefore, we replaced a large uterus segment with a bioengineered graft developed from decellularized uterus tissue and analyzed the immune response during the first 4 months in acellular or MSCs-recellularized scaffolds in the rat. Immunohistochemistry-stained infiltrating immune cells and plasma levels for 16 cytokines and chemokines were quantified. Results revealed that MSCs created an advantageous microenvironment by increasing anti-inflammatory interleukin 10 levels, and increasing the population of FOXP3+ TRegs and CD163+ M2 macrophages, and by reducing the CD8+ cytotoxic T cell population. Hence, MSCs should be considered an immunotherapeutic cell source with the ability to dictate regeneration success after decellularized tissue transplantation. [ABSTRACT FROM AUTHOR]
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- 2022
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20. Long-Term Gene Therapy Causes Transgene-Specific Changes in the Morphology of Regenerating Retinal Ganglion Cells.
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Rodger, Jennifer, Drummond, Eleanor S., Hellström, Mats, Robertson, Donald, and Harvey, Alan R.
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GENE therapy , *RETINAL ganglion cells , *NEUROTROPHIC functions , *NERVOUS system injuries , *NEURODEGENERATION , *LABORATORY rats , *GREEN fluorescent protein - Abstract
Recombinant adeno-associated viral (rAAV) vectors can be used to introduce neurotrophic genes into injured CNS neurons, promoting survival and axonal regeneration. Gene therapy holds much promise for the treatment of neurotrauma and neurodegenerative diseases; however, neurotrophic factors are known to alter dendritic architecture, and thus we set out to determine whether such transgenes also change the morphology of transduced neurons. We compared changes in dendritic morphology of regenerating adult rat retinal ganglion cells (RGCs) after long-term transduction with rAAV2 encoding: (i) green fluorescent protein (GFP), or (ii) bi-cistronic vectors encoding GFP and ciliary neurotrophic factor (CNTF), brain-derived neurotrophic factor (BDNF) or growth-associated protein-43 (GAP43). To enhance regeneration, rats received an autologous peripheral nerve graft onto the cut optic nerve of each rAAV2 injected eye. After 5-8 months, RGCs with regenerated axons were retrogradely labeled with fluorogold (FG). Live retinal wholemounts were prepared and GFP positive (transduced) or GFP negative (non-transduced) RGCs injected iontophoretically with 2% lucifer yellow. Dendritic morphology was analyzed using Neurolucida software. Significant changes in dendritic architecture were found, in both transduced and non-transduced populations. Multivariate analysis revealed that transgenic BDNF increased dendritic field area whereas GAP43 increased dendritic complexity. CNTF decreased complexity but only in a subset of RGCs. Sholl analysis showed changes in dendritic branching in rAAV2-BDNF-GFP and rAAV2-CNTF-GFP groups and the proportion of FG positive RGCs with aberrant morphology tripled in these groups compared to controls. RGCs in all transgene groups displayed abnormal stratification. Thus in addition to promoting cell survival and axonal regeneration, vector-mediated expression of neurotrophic factors has measurable, gene-specific effects on the morphology of injured adult neurons. Such changes will likely alter the functional properties of neurons and may need to be considered when designing vector-based protocols for the treatment of neurotrauma and neurodegeneration. [ABSTRACT FROM AUTHOR]
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- 2012
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21. Decellularization and recellularization of the ovary for bioengineering applications; studies in the mouse.
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Alshaikh, Ahmed Baker, Padma, Arvind Manikantan, Dehlin, Matilda, Akouri, Randa, Song, Min Jong, Brännström, Mats, and Hellström, Mats
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SODIUM dodecyl sulfate , *MESENCHYMAL stem cells , *OVARIES , *SCANNING electron microscopes , *FERTILITY preservation - Abstract
Background: Fertility preservation is particularly challenging in young women diagnosed with hematopoietic cancers, as transplantation of cryopreserved ovarian cortex in these women carries the risk for re-introducing cancer cells. Therefore, the construction of a bioengineered ovary that can accommodate isolated small follicles was proposed as an alternative to minimize the risk of malignancy transmission. Various options for viable bioengineered scaffolds have been reported in the literature. Previously, we reported three protocols for producing mouse ovarian scaffolds with the decellularization technique. The present study examined these scaffolds further, specifically with regards to their extracellular composition, biocompatibility and ability to support recellularization with mesenchymal stem cells. Material and methods: Three decellularization protocols based on 0.5% sodium dodecyl sulfate (Protocol 1; P1), or 2% sodium deoxycholate (P2), or a combination of the two detergents (P3) were applied to produce three types of scaffolds. The levels of collagen, elastin and sulfated glycosaminoglycans (sGAGs) were quantified in the remaining extracellular matrix. Detailed immunofluorescence and scanning electron microscopy imaging were conducted to assess the morphology and recellularization efficiency of the constructs after 14 days in vitro utilizing red fluorescent protein-labelled mesenchymal stem cells. Results: All protocols efficiently removed the DNA while the elastin content was not significantly reduced during the procedures. The SDS-protocol (P1) reduced the sGAG and the collagen content more than the SDC-protocol (P2). All scaffolds were biocompatible and recellularization was successful, particularly in several P2-derived scaffolds. The cells were extensively distributed throughout the constructs, with a denser distribution observed towards the ovarian cortex. The cell density was not significantly different (400 to 550 cells/mm2) between scaffold types. However, there was a tendency towards a higher cell density in the SDC-derived constructs. Scanning electron microscope images showed fibrous scaffolds with a dense repopulated surface structure. Conclusions: While there were differences in the key structural macromolecules between protocols, all scaffolds were biocompatible and showed effective recellularization. The results indicate that our SDC-protocol might be better than our SDS-protocol. However, additional studies are necessary to determine their suitability for attachment of small follicles and folliculogenesis. [ABSTRACT FROM AUTHOR]
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- 2020
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22. Efficacy and safety of tailored and dose-dense adjuvant chemotherapy and trastuzumab for resected HER2-positive breast cancer: Results from the phase 3 PANTHER trial.
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Papakonstantinou, Antroula, Matikas, Alexios, Bengtsson, Nils Olof, Malmström, Per, Hedayati, Elham, Steger, Guenther, Untch, Michael, Hübbert, Laila, Johansson, Hemming, Hellström, Mats, Gnant, Michael, Loibl, Sibylle, Greil, Richard, Moebus, Volker, Foukakis, Theodoros, and Bergh, Jonas
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TRASTUZUMAB , *EPIDERMAL growth factor receptors , *ADJUVANT treatment of cancer , *BREAST cancer , *COMBINATION drug therapy , *THERAPEUTIC use of antineoplastic agents , *RESEARCH , *CONFIDENCE intervals , *HEART , *RESEARCH methodology , *CELL receptors , *PROGNOSIS , *EVALUATION research , *MEDICAL cooperation , *FLUOROURACIL , *COMPARATIVE studies , *EPIRUBICIN , *CYCLOPHOSPHAMIDE , *RESEARCH funding , *COMBINED modality therapy , *BREAST tumors , *LONGITUDINAL method - Abstract
Background: Dose-dense (DD) adjuvant chemotherapy improves outcomes in early breast cancer (BC). However, there are no phase 3 randomized data to inform on its combination with trastuzumab for patients with human epidermal growth factor receptor 2 (HER2)-positive disease.Methods: This was a protocol-predefined secondary analysis of the randomized phase 3 Pan-European Tailored Chemotherapy (PANTHER) trial. Women 65 years old or younger with node-positive or high-risk, node-negative BC were randomized 1:1 to either tailored (according to hematologic nadirs) and DD epirubicin and cyclophosphamide followed by docetaxel or standard 5-fluorouracil, epirubicin, and cyclophosphamide plus docetaxel every 3 weeks. Patients with HER2-positive disease received 1 year of adjuvant trastuzumab. The primary endpoint was BC relapse-free survival. In addition, HER2-positive patients and an equal number of HER2-negative patients matched for age, treatment group, and institution who were enrolled at Swedish sites were asked to participate in a predefined study of cardiac safety and underwent echocardiography or multigated acquisition scanning and electrocardiography at the baseline and at 4 and 6 years of follow-up.Results: There were 342 HER2-positive patients; 335 received at least 1 dose of trastuzumab, and 29 patients discontinued trastuzumab prematurely. Relapse-free survival was not statistically significantly in favor of the tailored and DD group (hazard ratio, 0.68; 95% confidence interval, 0.37-1.27; P = .231). Cardiac outcomes after 4 and 6 years of follow-up did not differ significantly between HER2-positive and HER2-negative patients or between the 2 treatment groups.Conclusions: The combination of DD chemotherapy and trastuzumab decreased the relative risk for relapse by 32% in comparison with standard treatment, a statistically nonsignificant difference. Its efficacy and safety merit further evaluation as part of both escalation and de-escalation strategies. [ABSTRACT FROM AUTHOR]- Published
- 2020
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23. Vinflunine/gemcitabine versus carboplatin/gemcitabine as first-line treatment in cisplatin-ineligible patients with advanced urothelial carcinoma: A randomised phase II trial (VINGEM).
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Holmsten, Karin, Jensen, Niels Viggo, Mouritsen, Lene Sonne, Jonsson, Erika, Mellnert, Camilla, Agerbæk, Mads, Nilsson, Cecilia, Moe, Mette, Carus, Andreas, Öfverholm, Elisabeth, Lahdenperä, Outi, Brandberg, Yvonne, Johansson, Hemming, Hellström, Mats, Maase, Hans von der, Pappot, Helle, and Ullén, Anders
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ANTIMETABOLITES , *ANTINEOPLASTIC agents , *CISPLATIN , *CONFIDENCE intervals , *DRUG side effects , *FEBRILE neutropenia , *GASTROINTESTINAL diseases , *NAUSEA , *STATISTICAL sampling , *THROMBOCYTOPENIA , *VOMITING , *RANDOMIZED controlled trials , *TREATMENT effectiveness , *CARBOPLATIN , *CANCER fatigue ,BLADDER tumors - Abstract
The present study (VINGEM) is the first randomised trial comparing vinflunine/gemcitabine (VG) to standard carboplatin/gemcitabine (CG) in patients with advanced urothelial carcinoma (aUC) ineligible for treatment with cisplatin. Patients with aUC, creatinine clearance 30–60 ml/min, performance status ≤1 and no prior chemotherapy for metastatic disease were randomised to the experimental arm (vinflunine 280 or 250 mg/m2 day 1, gemcitabine 1000 mg/m2 days 1 and 8, q21 days) or the control arm (carboplatin AUC 4.5 day 1, gemcitabine 1000 mg/m2 days 1 and 8, q21 days). Primary end-point was progression-free survival (PFS). Sixty-two patients were randomised; a total of 59 patients were treated (29 VG, 30 CG). There was no significant difference in PFS between the treatment arms: median 6.2 months for VG versus 6.3 months for CG (hazard ratio [HR]: 0.75, 95% confidence interval [CI]: 0.44–1.28; P = 0.293). Median overall survival was 12.5 months for VG versus 10.6 months for CG. The overall response rate (ORR) was higher in the VG arm than in the CG arm (63% versus 40%) but was not statistically significant in the intention-to-treat analysis. Furthermore, VG showed a high complete response (CR) rate, 22% versus 3% in CG. In the per-protocol group, both ORR and CR were significantly higher for VG than for CG. The most common adverse events (AEs) were fatigue, haematological toxicities, gastrointestinal disorders and nausea/vomiting. Common grade III/IV AEs were neutropenia (VG 62%, CG 43%), thrombocytopenia (VG 7%, CG 37%) and febrile neutropenia (VG 31%, CG 7%). The combination of VG did not improve PFS compared with standard treatment with CG in patients unfit for cisplatin due to renal impairment. The response rate of VG indicates, however, an active regimen and warrants further studies. NCT02665039. • This was the first trial comparing vinflunine/gemcitabine (VG) vs carboplatin/gemcitabine (CG) in advanced urothelial cancer. • VG showed clinically meaningful efficacy with high overall and complete response rates. • VG did not improve median progression-free survival but was comparable with CG. • VG showed high incidence of neutropenia but with overall feasible side-effects. [ABSTRACT FROM AUTHOR]
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- 2020
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24. The development of an extended normothermic ex vivo reperfusion model of the sheep uterus to evaluate organ quality after cold ischemia in relation to uterus transplantation.
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Padma, Arvind M., Truong, MyLan, Jar‐Allah, Tagrid, Song, Min J., Oltean, Mihai, Brännström, Mats, and Hellström, Mats
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UTERUS , *REPERFUSION , *OXYGEN carriers , *SHEEP , *VASCULAR endothelium - Abstract
Introduction: Uterus transplantation has recently proved that infertility in women with uterine factor infertility can be cured. It is still an experimental procedure with numerous critical details remaining to be established, including tolerance to warm and cold ischemic insults. In preparation for human uterus transplantation trials, most teams use the sheep as a model system for research and team training, since the vasculature and the uterus is of similar size as in the human. We, therefore, aimed to develop an ex vivo sheep uterus reperfusion platform that mimics the reperfusion situation so that initial assessments and comparisons can be performed without the need for costly and labor‐intensive in vivo transplantation experiments. Material and methods: Isolated sheep uteri were perfused with the preservation solution IGL‐1 and were then exposed to cold ischemia for either 4 (n = 6) or 48 hours (n = 7). Uteri were then reperfused for 48 hours under normothermic conditions with an oxygenated recirculating perfusate containing growth factors and synthetic oxygen carriers. Histological and biochemical analysis of the perfusate was conducted to assess reperfusion injury. Results: Quantification of cell density indicated no significant edema in the myometrium or in the endometrium of uteri exposed to 4 hours cold ischemia and then a normothermic ex vivo reperfusion for 48 hours. Only the outer serosa layer and the inner columnar luminal epithelial cells were affected by the reperfusion. However, a much faster and severe reperfusion damage of all uterine layers were evident during the reperfusion experiment following 48 hours of cold ischemia. This was indicated by major accumulation of extracellular fluid, presence of apoptotic‐labeled glandular epithelial layer and vascular endothelium. A significant accumulation of lactate was measured in the perfusate with a subsequent decrease in pH. Conclusions: We developed a novel ex vivo sheep uterus model for prolonged perfusion. This model proved to be able to distinguish reperfusion injury‐related differences associated to organ preservation. The experimental setup is a platform that can be used to conduct further studies on uterine ischemia‐ and reperfusion injury that may lead to improved human uterus transplantation protocols. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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25. Systematic in vitro comparison of decellularization protocols for blood vessels.
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Simsa, Robin, Padma, Arvind Manikantan, Heher, Philipp, Hellström, Mats, Teuschl, Andreas, Jenndahl, Lachmi, Bergh, Niklas, and Fogelstrand, Per
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BLOOD vessels , *SODIUM dodecyl sulfate , *ANIONIC surfactants , *PERFUSION , *EXTRACELLULAR matrix - Abstract
Decellularization of native blood vessels is a promising technology to generate 3D biological scaffolds for vascular grafting. Blood vessel decellularization has been performed in previous studies under various experimental conditions, that complicates comparison and optimization of suitable protocols. The goal of this work was to systematically compare the decellularization and recellularization efficacy of 5 different protocols utilizing the detergents sodium dodecyl sulfate (SDS), sodium deoxycholate (SDC), CHAPS and TritonX-100 together with DNA-removing enzymes on porcine vena cava in a perfusion bioreactor setup. Additionally, we tested the effect of DNase on the extracellular matrix (ECM) properties. We found that all protocols could efficiently decellularize blood vessels. Mechanical strength, collagen preservation and ECM integrity were similar among all tested detergents, yet TritonX protocols required long-term DNase application for complete decellularization. However, TritonX-based protocols showed the greatest recellularization efficacy with HUVECs in vitro. Furthermore, we developed a novel protocol for TritonX which improved recellularization and reduced total process time and ECM stiffness compared to previous protocols. SDS, SDC and CHAPS based protocols had a lower recellularization potential. In conclusion, decellularization of blood vessels can be achieved with all tested reagents, but TritonX treated ECM can be most efficiently recellularized with endothelial cells. [ABSTRACT FROM AUTHOR]
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- 2018
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26. Linking FOXO3, NCOA3, and TCF7L2 to Ras pathway phenotypes through a genome-wide forward genetic screen in human colorectal cancer cells.
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Kundu, Snehangshu, Ali, Muhammad Akhtar, Handin, Niklas, Padhan, Narendra, Larsson, Jimmy, Karoutsou, Maria, Ban, Kenneth, Wiśniewski, Jacek R., Artursson, Per, He, Liqun, Hellström, Mats, and Sjöblom, Tobias
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GENETICS of colon cancer , *RAS oncogenes , *FORKHEAD transcription factors , *MITOGEN-activated protein kinases , *PHOSPHORYLATION , *GENETIC mutation - Abstract
Background: The Ras pathway genes KRAS, BRAF, or ERBBs have somatic mutations in ~ 60% of human colorectal carcinomas. At present, it is unknown whether the remaining cases lack mutations activating the Ras pathway or whether they have acquired mutations in genes hitherto unknown to belong to the pathway. Methods: To address the second possibility and extend the compendium of Ras pathway genes, we used genomewide transposon mutagenesis of two human colorectal cancer cell systems deprived of their activating KRAS or BRAF allele to identify genes enabling growth in low glucose, a Ras pathway phenotype, when targeted. Results: Of the 163 recurrently targeted genes in the two different genetic backgrounds, one-third were known cancer genes and one-fifth had links to the EGFR/Ras/MAPK pathway. When compared to cancer genome sequencing datasets, nine genes also mutated in human colorectal cancers were identified. Among these, stable knockdown of FOXO3, NCOA3, and TCF7L2 restored growth in low glucose but reduced MEK/MAPK phosphorylation, reduced anchorage-independent growth, and modulated expressions of GLUT1 and Ras pathway related proteins. Knockdown of NCOA3 and FOXO3 significantly decreased the sensitivity to cetuximab of KRAS mutant but not wild-type cells. Conclusions: This work establishes a proof-of-concept that human cell-based genome-wide forward genetic screens can assign genes to pathways with clinical importance in human colorectal cancer. [ABSTRACT FROM AUTHOR]
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- 2018
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27. Inhibitory effect of punicalagin on lipopolysaccharide-induced neuroinflammation, oxidative stress and memory impairment via inhibition of nuclear factor-kappaB.
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Kim, Young Eun, Hwang, Chul Ju, Lee, Hee Pom, Kim, Chun Sik, Son, Dong Ju, Ham, Young Wan, Hellström, Mats, Han, Sang-Bae, Kim, Hee Sik, Park, Eun Kyung, and Hong, Jin Tae
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NF-kappa B , *LIPOPOLYSACCHARIDES , *OXIDATIVE stress , *ALZHEIMER'S disease treatment , *ANTI-inflammatory agents , *IN vitro studies - Abstract
Neuroinflammation is significant in the pathogenesis and development of Alzheimer's disease (AD). Previously, we showed lipopolysaccharide (LPS)-induced neuroinflammation caused memory impairment. We investigated the possible preventive effects of punicalagin (PUN), a component of pomegranate, on memory deficiency caused by LPS, along with the fundamental mechanisms. LPS-treated cultured astrocytes and microglial BV-2 cells were investigated for anti -neuroinflammatory effects of PUN. PUN (1.5 mg/kg) ameliorates LPS (250 μg/kg daily 7 times)-induced memory impairment as well as prevents the LPS-induced expression of inflammatory proteins. In in vitro study, we also found that PUN (1 μg/ml) inhibited the LPS-(10, 20 and 50 μM) induced expression of iNOS and Cox-2 as well as the production of ROS, NO, TNF-α and IL-1β. PUN also suppress activation of NF-κB via inhibition of IκB degradation as well as p50 and p65 translocation into the nucleus in LPS treated mouse brain and cultured astrocytes and microglial BV-2 cells. Consistent with the inhibitory effect on neuro inflammation, PUN inhibited LPS-induced Aβ 1-42 generation through down-regulation of APP and BACE1 expression in in vivo and in vitro study. Moreover, PUN directly binds to NF-κB subunit p50 evidenced by a docking model and pull down assay. These results suggest that PUN inhibits LPS-induced memory impairment via anti-inflammatory and anti -amylogenic mechanisms through inhibition of NF-κB activation. [ABSTRACT FROM AUTHOR]
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- 2017
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28. Anti-Inflammatory Effect of Titrated Extract of Centella asiatica in Phthalic Anhydride-Induced Allergic Dermatitis Animal Model.
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Ju Ho Park, Ji Yeon Choi, Dong Ju Son, Eun Kyung Park, Min Jong Song, Hellström, Mats, and Jin Tae Hong
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CENTELLA asiatica , *ANHYDRIDES , *CONTACT dermatitis , *NITRIC-oxide synthases , *CYCLOOXYGENASE 2 , *ENZYME-linked immunosorbent assay - Abstract
Centella asiatica has potent antioxidant and anti-inflammatory properties. However, its anti-dermatitic effect has not yet been reported. In this study, we investigated the anti-dermatitic effects of titrated extract of Centella asiatica (TECA) in a phthalic anhydride (PA)-induced atopic dermatitis (AD) animal model as well as in vitro model. An AD-like lesion was induced by the topical application of five percent PA to the dorsal skin or ear of Hos:HR-1 mouse. After AD induction, 100 μL of 0.2% and 0.4% of TECA (40 μg or 80 μg/cm2) was spread on the dorsum of the ear or back skin three times a week for four weeks. We evaluated dermatitis severity, histopathological changes and changes in protein expression by Western blotting for inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and NF-κB activity, which were determined by electromobility shift assay (EMSA). We also measured TNF-α, IL-1β, IL-6, and IgE concentration in the blood of AD mice by enzyme-linked immunosorbent assay (ELISA). TECA treatment attenuated the development of PA-induced atopic dermatitis. Histological analysis showed that TECA inhibited hyperkeratosis, mast cells and infiltration of inflammatory cells. TECA treatment inhibited expression of iNOS and COX-2, and NF-κB activity as well as the release of TNF-α, IL-1β, IL-6, and IgE. In addition, TECA (1, 2, 5 μg/mL) potently inhibited Lipopolysaccharide (LPS) (1 μg/mL)-induced NO production, expression of iNOS and COX-2, and NF-κB DNA binding activities in RAW264.7 macrophage cells. Our data demonstrated that TECA could be a promising agent for AD by inhibition of NF-κB signaling. [ABSTRACT FROM AUTHOR]
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- 2017
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29. Effect of Tailored Dose-Dense Chemotherapy vs Standard 3-Weekly Adjuvant Chemotherapy on Recurrence-Free Survival Among Women With High-Risk Early Breast Cancer: A Randomized Clinical Trial.
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Foukakis, Theodoros, von Minckwitz, Gunter, Bengtsson, Nils-Olof, Brandberg, Yvonne, Wallberg, Birgitta, Fornander, Tommy, Mlineritsch, Brigitte, Schmatloch, Sabine, Singer, Christian F., Steger, Günther, Egle, Daniel, Karlsson, Eva, Carlsson, Lena, Loibl, Sibylle, Untch, Michael, Hellström, Mats, Johansson, Hemming, Anderson, Harald, Malmström, Per, and Gnant, Michael
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CANCER chemotherapy , *BREAST cancer , *CANCER prevention , *BREAST cancer treatment , *ANTINEOPLASTIC agents , *ANTINEOPLASTIC antibiotics , *BREAST tumors , *CANCER relapse , *COMBINED modality therapy , *COMPARATIVE studies , *DRUG administration , *FLUOROURACIL , *HYDROCARBONS , *RESEARCH methodology , *MEDICAL cooperation , *PROGNOSIS , *QUALITY of life , *RESEARCH , *EVALUATION research , *CYCLOPHOSPHAMIDE , *EPIRUBICIN ,BREAST cancer chemotherapy - Abstract
Importance: Standard dosing of chemotherapy based on body surface area results in marked interpatient variation in pharmacokinetics, toxic effects, and efficacy. Whether tailored dosing can improve outcomes is unknown, as is the role of dose-dense adjuvant chemotherapy.Objective: To determine whether tailored dose-dense adjuvant chemotherapy improves the outcomes of early breast cancer compared with a standard 3-weekly chemotherapy schedule.Design, Setting, and Participants: A randomized, open-label, phase 3 trial of women aged 65 years and younger who had surgery for nonmetastatic node-positive or high-risk node-negative breast cancer at 86 sites in Sweden, Germany, and Austria between February 20, 2007, and September 14, 2011.Interventions: Patients were randomized 1:1 either to 4 cycles of leukocyte nadir-based tailored and dose-dense adjuvant epirubicin and cyclophosphamide every 2 weeks followed by 4 cycles of tailored dose-dense docetaxel every 2 weeks, or to standard-interval chemotherapy with 3 cycles of fluorouracil and epirubicin-cyclophosphamide every 3 weeks followed by 3 cycles of docetaxel every 3 weeks.Main Outcomes and Measures: The primary end point was breast cancer recurrence-free survival (BCRFS). Secondary end points included 5-year event-free survival (EFS), distant disease-free survival (DDFS), overall survival (OS), and rates of grade 3 or 4 toxic effects.Results: Among 2017 randomized patients (1006 in the tailored dose-dense group and 1011 in the control group; median [IQR] age, 51 [45-58] years; 80% with hormone receptor-positive tumors; 97% with node-positive disease), 2000 received study treatment (≥1 cycle of chemotherapy; 1001 in the tailored dose-dense group and 999 in the control group). After a median follow-up of 5.3 years (IQR, 4.5-6.1 years), 269 BCRFS events were reported, 118 in the tailored dose-dense group and 151 in the control group (HR, 0.79; 95% CI, 0.61-1.01; log-rank P = .06; 5-year BCRFS, 88.7% vs 85.0%). The tailored dose-dense group had significantly better EFS than the control group (HR, 0.79; 95% CI, 0.63-0.99; P = .04; 5-year EFS, 86.7% vs 82.1%). The groups did not differ in OS (HR, 0.77; 95% CI, 0.57-1.05; P = .09; 5-year OS, 92.1% vs 90.2%) or DDFS (HR, 0.83; 95% CI, 0.64-1.08; P = .17; 5-year DDFS, 89.4% vs 86.7%). Grade 3 or 4 nonhematologic toxic effects occurred in 527 (52.6%) in the tailored dose-dense group and 366 (36.6%) in the control group.Conclusions and Relevance: Among women with high-risk early breast cancer, the use of tailored dose-dense chemotherapy compared with standard adjuvant chemotherapy did not result in a statistically significant improvement in breast cancer recurrence-free survival. Nonhematologic toxic effects were more frequent in the tailored dose-dense group.Trial Registration: clinicaltrials.gov Identifier: NCT00798070; isrctn.org Identifier: ISRCTN39017665. [ABSTRACT FROM AUTHOR]- Published
- 2016
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30. The Sphingosine-1-Phosphate Receptor S1PR1 Restricts Sprouting Angiogenesis by Regulating the Interplay between VE-Cadherin and VEGFR2
- Author
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Gaengel, Konstantin, Niaudet, Colin, Hagikura, Kazuhiro, Siemsen, Bàrbara Laviña, Muhl, Lars, Hofmann, Jennifer J., Ebarasi, Lwaki, Nyström, Staffan, Rymo, Simin, Chen, Long Long, Pang, Mei-Fong, Jin, Yi, Raschperger, Elisabeth, Roswall, Pernilla, Schulte, Dörte, Benedito, Rui, Larsson, Jimmy, Hellström, Mats, Fuxe, Jonas, and Uhlén, Per
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SPHINGOSINE-1-phosphate , *NEOVASCULARIZATION inhibitors , *CADHERINS , *VASCULAR endothelial growth factors , *BLOOD vessels , *EMBRYOLOGY , *ENDOTHELIAL cells - Abstract
Summary: Angiogenesis, the process by which new blood vessels arise from preexisting ones, is critical for embryonic development and is an integral part of many disease processes. Recent studies have provided detailed information on how angiogenic sprouts initiate, elongate, and branch, but less is known about how these processes cease. Here, we show that S1PR1, a receptor for the blood-borne bioactive lipid sphingosine-1-phosphate (S1P), is critical for inhibition of angiogenesis and acquisition of vascular stability. Loss of S1PR1 leads to increased endothelial cell sprouting and the formation of ectopic vessel branches. Conversely, S1PR1 signaling inhibits angiogenic sprouting and enhances cell-to-cell adhesion. This correlates with inhibition of vascular endothelial growth factor-A (VEGF-A)-induced signaling and stabilization of vascular endothelial (VE)-cadherin localization at endothelial junctions. Our data suggest that S1PR1 signaling acts as a vascular-intrinsic stabilization mechanism, protecting developing blood vessels against aberrant angiogenic responses. [Copyright &y& Elsevier]
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- 2012
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31. Gamma-Secretase Inhibitor Treatment Promotes VEGF-A-Driven Blood Vessel Growth and Vascular Leakage but Disrupts Neovascular Perfusion.
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Kalén, Mattias, Heikura, Tommi, Karvinen, Henna, Nitzsche, Anja, Weber, Holger, Esser, Norbert, Ylä-Herttuala, Seppo, and Hellström, Mats
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CARCINOGENESIS , *CELL differentiation , *VASCULAR endothelial growth factors , *ALZHEIMER'S disease , *METASTASIS , *NEOVASCULARIZATION , *BLOOD-vessel development , *ANTINEOPLASTIC agents , *LABORATORY mice - Abstract
The Notch signaling pathway is essential for normal development due to its role in control of cell differentiation, proliferation and survival. It is also critically involved in tumorigenesis and cancer progression. A key enzyme in the activation of Notch signaling is the gamma-secretase protein complex and therefore, gamma-secretase inhibitors (GSIs)- originally developed for Alzheimer's disease-are now being evaluated in clinical trials for human malignancies. It is also clear that Notch plays an important role in angiogenesis driven by Vascular Endothelial Growth Factor A (VEGF-A)-a process instrumental for tumor growth and metastasis. The effect of GSIs on tumor vasculature has not been conclusively determined. Here we report that Compound X (CX), a GSI previously reported to potently inhibit Notch signaling in vitro and in vivo, promotes angiogenic sprouting in vitro and during developmental angiogenesis in mice. Furthermore, CX treatment suppresses tumor growth in a mouse model of renal carcinoma, leads to the formation of abnormal vessels and an increased tumor vascular density. Using a rabbit model of VEGF-A-driven angiogenesis in skeletal muscle, we demonstrate that CX treatment promotes abnormal blood vessel growth characterized by vessel occlusion, disrupted blood flow, and increased vascular leakage. Based on these findings, we propose a model for how GSIs and other Notch inhibitors disrupt tumor blood vessel perfusion, which might be useful for understanding this new class of anti-cancer agents. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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32. Heterogeneity prevails: the state of clinical trial data management in Europe--results of a survey of ECRIN centres.
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Kuchinke, Wolfgang, Ohmann, Christian, Qin Yang, Salas, Nader, Lauritsen, Jens, Gueyffier, Francois, Leizorovicz, Alan, Schade-Brittinger, Carmen, Wittenberg, Michael, Voko, Zoltán, Gaynor, Siobhan, Cooney, Margaret, Doran, Peter, Maggioni, Aldo, Lorimer, Andrea, Torres, Ferràn, McPherson, Gladys, Charwill, Jim, Hellström, Mats, and Lejeune, Stéphane
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DATABASE management , *CLINICAL trials , *MEDICAL experimentation on humans , *MEDICAL care - Abstract
Background: The use of Clinical Data Management Systems (CDMS) has become essential in clinical trials to handle the increasing amount of data that must be collected and analyzed. With a CDMS trial data are captured at investigator sites with "electronic Case Report Forms". Although more and more of these electronic data management systems are used in academic research centres an overview of CDMS products and of available data management and quality management resources for academic clinical trials in Europe is missing. Methods: The ECRIN (European Clinical Research Infrastructure Network) data management working group conducted a two-part standardized survey on data management, software tools, and quality management for clinical trials. The questionnaires were answered by nearly 80 centres/units (with an overall response rate of 47% and 43%) from 12 European countries and EORTC. Results: Our survey shows that about 90% of centres have a CDMS in routine use. Of these CDMS nearly 50% are commercial systems; Open Source solutions don't play a major role. In general, solutions used for clinical data management are very heterogeneous: 20 different commercial CDMS products (7 Open Source solutions) in addition to 17/18 proprietary systems are in use. The most widely employed CDMS products are MACRO™ and Capture System™, followed by solutions that are used in at least 3 centres: eResearch Network™, CleanWeb™, GCP Base™ and SAS™. Although quality management systems for data management are in place in most centres/units, there exist some deficits in the area of system validation. Conclusions: Because the considerable heterogeneity of data management software solutions may be a hindrance to cooperation based on trial data exchange, standards like CDISC (Clinical Data Interchange Standard Consortium) should be implemented more widely. In a heterogeneous environment the use of data standards can simplify data exchange, increase the quality of data and prepare centres for new developments (e.g. the use of EHR for clinical research). Because data management and the use of electronic data capture systems in clinical trials are characterized by the impact of regulations and guidelines, ethical concerns are discussed. In this context quality management becomes an important part of compliant data management. To address these issues ECRIN will establish certified data centres to support electronic data management and associated compliance needs of clinical trial centres in Europe. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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33. Blocking VEGFR-3 suppresses angiogenic sprouting and vascular network formation.
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Tammela, Tuomas, Zarkada, Georgia, Wallgard, Elisabet, Murtomäki, Aino, Suchting, Steven, Wirzenius, Maria, Waltari, Marika, Hellström, Mats, Schomber, Tibor, Peltonen, Reetta, Freitas, Catarina, Duarte, Antonio, Isoniemi, Helena, Laakkonen, Pirjo, Christofori, Gerhard, Ylä-Herttuala, Seppo, Shibuya, Masabumi, Pytowski, Bronislaw, Eichmann, Anne, and Betsholtz, Christer
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NEOVASCULARIZATION , *PATHOLOGY , *TUMOR growth , *DEGENERATION (Pathology) , *VASCULAR endothelial growth factors , *LYMPHANGIOGRAPHY , *ENDOTHELIUM , *PROTEIN-tyrosine kinases , *MONOCLONAL antibodies - Abstract
Angiogenesis, the growth of new blood vessels from pre-existing vasculature, is a key process in several pathological conditions, including tumour growth and age-related macular degeneration. Vascular endothelial growth factors (VEGFs) stimulate angiogenesis and lymphangiogenesis by activating VEGF receptor (VEGFR) tyrosine kinases in endothelial cells. VEGFR-3 (also known as FLT-4) is present in all endothelia during development, and in the adult it becomes restricted to the lymphatic endothelium. However, VEGFR-3 is upregulated in the microvasculature of tumours and wounds. Here we demonstrate that VEGFR-3 is highly expressed in angiogenic sprouts, and genetic targeting of VEGFR-3 or blocking of VEGFR-3 signalling with monoclonal antibodies results in decreased sprouting, vascular density, vessel branching and endothelial cell proliferation in mouse angiogenesis models. Stimulation of VEGFR-3 augmented VEGF-induced angiogenesis and sustained angiogenesis even in the presence of VEGFR-2 (also known as KDR or FLK-1) inhibitors, whereas antibodies against VEGFR-3 and VEGFR-2 in combination resulted in additive inhibition of angiogenesis and tumour growth. Furthermore, genetic or pharmacological disruption of the Notch signalling pathway led to widespread endothelial VEGFR-3 expression and excessive sprouting, which was inhibited by blocking VEGFR-3 signals. Our results implicate VEGFR-3 as a regulator of vascular network formation. Targeting VEGFR-3 may provide additional efficacy for anti-angiogenic therapies, especially towards vessels that are resistant to VEGF or VEGFR-2 inhibitors. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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34. PDGF-C is a new protease-activated ligand for the PDGF α-receptor.
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Li, Xuri, Pontén, Annica, Aase, Karin, Karlsson, Linda, Abramsson, Alexandra, Uutela, Marko, Bäckström, Gudrun, Hellström, Mats, Boström, Hans, Li, Hong, Soriano, Philippe, Betsholtz, Christer, Heldin, Carl-Henrik, Alitalo, Kari, Östman, Arne, and Eriksson, Ulf
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PLATELET-derived growth factor , *FIBROBLASTS - Abstract
Platelet-derived growth factors (PDGFs) are important in many types of mesenchymal cell. Here we identify a new PDGF, PDGF-C, which binds to and activates the PDGF α-receptor. PDGF-C is activated by proteolysis and induces proliferation of fibroblasts when overexpressed in transgenic mice. In situ hybridization analysis in the murine embryonic kidney shows preferential expression of PDGF-C messenger RNA in the metanephric mesenchyme during epithelial conversion. Analysis of kidneys lacking the PDGF α-receptor shows selective loss of mesenchymal cells adjacent to sites of expression of PDGF-C mRNA; this is not found in kidneys from animals lacking PDGF-A or both PDGF-A and PDGF-B, indicating that PDGF-C may have a unique function. [ABSTRACT FROM AUTHOR]
- Published
- 2000
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35. Microarray analysis of blood microvessels from PDGF-B and PDGF-Rβ mutant mice identifies novel markers for brain pericytes.
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Bondjers, Cecilia, Liqun He, Takemoto, Minoru, Norlin, Jenny, Asker, Noomi, Hellström, Mats, Lindahl, Per, and Betsholtz, Christer
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PLATELET-derived growth factor , *POTASSIUM channels , *BIOMARKERS , *CENTRAL nervous system , *PROTEIN microarrays - Abstract
The article presents a study which described the identification of novel markers for brain pericytes by way of microarray analysis of blood microvessels from platelet-derived growth factor (PDGF)-B and PDGF-Rβ. The expression of adenosine triphosphate-sensitive potassium-channel Kir 6.1, sulfonylurea receptor 2 and delta-homologue 1 in central nervous system (CNS) pericytes is described. The restriction of pericytic expression of Kir 6.1 in the CNS is revealed.
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- 2006
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36. Intestinal Preservation Injury: A Comparison Between Rat, Porcine and Human Intestines.
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Søfteland, John Mackay, Casselbrant, Anna, Biglarnia, Ali-Reza, Linders, Johan, Hellström, Mats, Pesce, Antonio, Padma, Arvind Manikantan, Jiga, Lucian Petru, Hoinoiu, Bogdan, Ionac, Mihai, and Oltean, Mihai
- Abstract
Advanced preservation injury (PI) after intestinal transplantation has deleterious short- and long-term effects and constitutes a major research topic. Logistics and costs favor rodent studies, whereas clinical translation mandates studies in larger animals or using human material. Despite diverging reports, no direct comparison between the development of intestinal PI in rats, pigs, and humans is available. We compared the development of PI in rat, porcine, and human intestines. Intestinal procurement and cold storage (CS) using histidine–tryptophan–ketoglutarate solution was performed in rats, pigs, and humans. Tissue samples were obtained after 8, 14, and 24 h of CS), and PI was assessed morphologically and at the molecular level (cleaved caspase-3, zonula occludens, claudin-3 and 4, tricellulin, occludin, cytokeratin-8) using immunohistochemistry and Western blot. Intestinal PI developed slower in pigs compared to rats and humans. Tissue injury and apoptosis were significantly higher in rats. Tight junction proteins showed quantitative and qualitative changes differing between species. Significant interspecies differences exist between rats, pigs, and humans regarding intestinal PI progression at tissue and molecular levels. These differences should be taken into account both with regards to study design and the interpretation of findings when relating them to the clinical setting. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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37. Decellularization of the mouse ovary: comparison of different scaffold generation protocols for future ovarian bioengineering.
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Alshaikh, Ahmed Baker, Padma, Arvind Manikantan, Dehlin, Matilda, Akouri, Randa, Song, Min Jong, Brännström, Mats, and Hellström, Mats
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OVARIAN follicle , *BIOENGINEERING , *SODIUM dodecyl sulfate , *OVARIES , *MICE - Abstract
Background: In order to preserve fertility in young women with disseminated cancer, e.g. leukemia, an approach that has been suggested is to retransplant isolated small follicles within an ovarian matrix free from malignant cells and with no risk for contamination. The present study evaluates the first step to create a bioengineered ovarian construct that can act as growth-supporting tissue for isolated small follicles that are dependent on a stroma for normal follicular maturation. The present study used the intact mouse ovary to develop a mouse ovarian scaffold through various protocols of decellularization. Material and methods: Potential Immunogenic DNA and intracellular components were removed from whole mouse ovaries by agitation in a 0.5% sodium dodecyl sulfate solution (Protocol 1; P1), or in a 2% sodium deoxycholate solution (P2) or by a combination of the two (P3). The remaining decelluralized ovarian extracellular matrix structure was then assessed based on the DNA- and protein content, and was further evaluated histologically by haematoxylin and eosin-, Verhoeff's van gieson- (for elastin), Masson's trichrome- (for collagens) and Alcian blue (for glycosaminoglycans) staining. We also evaluated the decellularization efficiency using the mild detergent Triton-X100 (1%). Results: Sodium dodecyl sulfate efficiently removed DNA and intracellular components from the ovarian tissue but also significantly reduced the integrity of the remaining ovarian extracellular matrix. Sodium deoxycholate, a considerably milder detergent compared to sodium dodecyl sulfate, preserved the ovarian extracellular matrix better, evident by a more distinct staining for glycosaminoglycan, collagen and elastic fibres. Triton-X100 was found ineffective as a decellularization reagent for mouse ovaries in our settings. Conclusions: The sodium dodecyl sulfate generated ovarian scaffolds contained minute amounts of DNA that may be an advantage to evade a detrimental immune response following engraftment. The sodium deoxycholate generated ovarian scaffolds had higher donor DNA content, yet, retained the extracellular composition better and may therefore have improved recellularization and other downstream bioengineering applications. These two novel types of mouse ovarian scaffolds serve as promising scaffold-candidates for future ovarian bioengineering experiments. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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38. The development of an extended normothermic ex vivo reperfusion model of the sheep uterus to evaluate organ quality after cold ischemia in relation to uterus transplantation.
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Padma, Arvind Manikantan, Truong, MyLan, Jar-Allah, Tagrid, Song, Min Jong, Oltean, Mihai, Brännström, Mats, Hellström, Mats, Padma, Arvind M, and Song, Min J
- Abstract
Introduction: Uterus transplantation has recently proved that infertility in women with uterine factor infertility can be cured. It is still an experimental procedure with numerous critical details remaining to be established, including tolerance to warm and cold ischemic insults. In preparation for human uterus transplantation trials, most teams use the sheep as a model system for research and team training, since the vasculature and the uterus is of similar size as in the human. We, therefore, aimed to develop an ex vivo sheep uterus reperfusion platform that mimics the reperfusion situation so that initial assessments and comparisons can be performed without the need for costly and labor-intensive in vivo transplantation experiments.Material and Methods: Isolated sheep uteri were perfused with the preservation solution IGL-1 and were then exposed to cold ischemia for either 4 (n = 6) or 48 hours (n = 7). Uteri were then reperfused for 48 hours under normothermic conditions with an oxygenated recirculating perfusate containing growth factors and synthetic oxygen carriers. Histological and biochemical analysis of the perfusate was conducted to assess reperfusion injury.Results: Quantification of cell density indicated no significant edema in the myometrium or in the endometrium of uteri exposed to 4 hours cold ischemia and then a normothermic ex vivo reperfusion for 48 hours. Only the outer serosa layer and the inner columnar luminal epithelial cells were affected by the reperfusion. However, a much faster and severe reperfusion damage of all uterine layers were evident during the reperfusion experiment following 48 hours of cold ischemia. This was indicated by major accumulation of extracellular fluid, presence of apoptotic-labeled glandular epithelial layer and vascular endothelium. A significant accumulation of lactate was measured in the perfusate with a subsequent decrease in pH.Conclusions: We developed a novel ex vivo sheep uterus model for prolonged perfusion. This model proved to be able to distinguish reperfusion injury-related differences associated to organ preservation. The experimental setup is a platform that can be used to conduct further studies on uterine ischemia- and reperfusion injury that may lead to improved human uterus transplantation protocols. [ABSTRACT FROM AUTHOR]- Published
- 2019
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39. The Sphingosine-1-Phosphate Receptor S1PR1 Restricts Sprouting Angiogenesis by Regulating the Interplay between VE-Cadherin and VEGFR2
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Gaengel, Konstantin, Niaudet, Colin, Hagikura, Kazuhiro, Laviña, Bàrbara, Muhl, Lars, Hofmann, Jennifer J., Ebarasi, Lwaki, Nyström, Staffan, Rymo, Simin, Chen, Long Long, Pang, Mei-Fong, Jin, Yi, Raschperger, Elisabeth, Roswall, Pernilla, Schulte, Dörte, Benedito, Rui, Larsson, Jimmy, Hellström, Mats, Fuxe, Jonas, and Uhlén, Per
- Published
- 2012
- Full Text
- View/download PDF
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