SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "L773:1530 0307 OR L773:0023 6837 "

Sökning: L773:1530 0307 OR L773:0023 6837

  • Resultat 1-50 av 167
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  •  
2.
  •  
3.
  • Fiorentino, M., et al. (författare)
  • Immunohistochemical Expression of BRCA1 in Prostate Cancer
  • 2009
  • Ingår i: Laboratory Investigation. - : Nature Publishing Group. - 0023-6837 .- 1530-0307. ; 22, s. 169A-169A
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • Background: BRCA1 is a multifunctional protein involved in DNA repair, gene transcription and the regulation of cell-cycle check-points. While germline mutations of BRCA1 are rare in prostate cancer and seem to play a limited role in tumor susceptibility, BRCA1 expression has not been investigated to date.Design: We analyzed the immunohistochemical expression of BRCA1 in paraffin embedded samples from 524 men with prostate cancer belonging to the Physicians’ Health Study and the Swedish Watchful Waiting cohorts of prostate cancer patients. High density tissue micro-arrays (TMA) including at least three tumor cores for each case were utilized for the immunohistochemical staining with the monoclonal MS110 antibody specific for the N-terminus of the 220 kDa BRCA1 protein. Cases were scored as negative or positive for BRCA1 immunostaining. The Ki67 proliferation index was also assessed on the same TMAs and evaluated by quantitative image analysis.Results: A positive nuclear immunostaining for BRCA1 was revealed in 62 of 524 (11.9%) patients while normal prostate control cores were all negative. BRCA1 positive tumors were associated with 4 times greater proliferation rate compared to BRCA1 negative tumors (p ∼ 0.0003). In addition, we found a linear trend such that tumors with greater number of TMA cores expressing BRCA1 had stronger extent of proliferation. Men with BRCA1 positive tumors had a slightly higher Gleason’s score (mean 7.5) compared to those negative for BRCA1 (mean 7) No significant correlation was found between BRCA1 staining and cancer-specific death.Conclusions: BRCA1 protein is expressed in a small subset of prostate cancers characterized by high proliferation index but not in normal prostate tissue. Expression of BRCA1 might be acquired in selected tumors to prevent DNA damage in actively replicating cells. A different role independent of germline mutations might be disclosed for BRCA1 as cell cycle regulator in prostate cancer.
  •  
4.
  •  
5.
  • Tessier-Cloutier, Basile, et al. (författare)
  • Cell of Origin (COO) of Diffuse Large B-Cell Lymphoma (DLBCL) in Patients with Systemic Lupus Erythematosus (SLE)
  • 2017
  • Ingår i: Modern Pathology. - Vancouver Gen Hosp, Vancouver, BC, Canada. McGill Univ, Ctr Hlth, Montreal, PQ, Canada. Uppsala Univ, Uppsala, Sweden. British Columbia Canc Agcy, Vancouver, BC, Canada. Jewish Gen Hosp, Montreal, PQ, Canada. Med Univ South Carolina, Charleston, SC USA. Univ Calgary, Calgary, AB, Canada. Northwestern Univ, Chicago, IL 60611 USA. : NATURE PUBLISHING GROUP. - 0893-3952 .- 1530-0285. ; 97, s. 381A-381A
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
  •  
6.
  • Andersson Sjöland, Annika, et al. (författare)
  • ROS-induced endothelial stress contributes to pulmonary fibrosis through pericytes and Wnt signaling.
  • 2015
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 1530-0307 .- 0023-6837.
  • Tidskriftsartikel (refereegranskat)abstract
    • Pulmonary fibrosis is a grave diagnosis with insidious progression, generally considered as a consequence of aberrant epithelial wound healing and excessive scarring. This process is commonly modeled in animals by local bleomycin administration, resulting in peribronchial inflammation and subsequent fibrosis. We have previously described initiation and early development of distal pulmonary fibrosis following repeated subcutaneous bleomycin injections (systemic administration). The aim of this study was to identify mechanisms for the development of pulmonary fibrosis, which we hypothesize is related to endothelial stress and activation. Bleomycin was administered subcutaneously 3 times/week during 0.33-4w, and parenchymal alterations were studied. In addition, we used microvascular endothelial cells to investigate effects of bleomycin in vitro. Our results confirmed that systemic administration of bleomycin exerts oxidative stress indicated by an increase in Sod1 at 0.33, 1, and 4w (P<0.05). Endothelial cells were activated (increased CD106 expression) from 1w and onwards (P<0.05), and p21 expression was increased 2-3 times throughout the study (P<0.05) as were the number of β-catenin-positive nuclei (P<0.001). Wnt3a was increased at 0.33, 1, and 4w (P<0.01) and Wnt5a from 1w and onwards (P<0.001). The present study suggests that bleomycin-induced reactive oxygen species (ROS) causes DNA stress affecting the endothelial niche, initiating repair processes including Wnt signaling. The repeated systemic administrations disrupt a normally fine-tuned balance in the Wnt signaling. In addition, pericyte differentiation was affected, which may have significant effects on fibrosis due to their ability to differentiate into myofibroblasts. We conclude that the endothelial niche may have an important role in the development of pulmonary fibrosis and warrants further investigations.Laboratory Investigation advance online publication, 14 September 2015; doi:10.1038/labinvest.2015.100.
  •  
7.
  • Balkenhol, Maschenka C. A., et al. (författare)
  • Deep learning assisted mitotic counting for breast cancer
  • 2019
  • Ingår i: Laboratory Investigation. - : NATURE PUBLISHING GROUP. - 0023-6837 .- 1530-0307. ; 99:11, s. 1596-1606
  • Tidskriftsartikel (refereegranskat)abstract
    • As part of routine histological grading, for every invasive breast cancer the mitotic count is assessed by counting mitoses in the (visually selected) region with the highest proliferative activity. Because this procedure is prone to subjectivity, the present study compares visual mitotic counting with deep learning based automated mitotic counting and fully automated hotspot selection. Two cohorts were used in this study. Cohort A comprised 90 prospectively included tumors which were selected based on the mitotic frequency scores given during routine glass slide diagnostics. This pathologist additionally assessed the mitotic count in these tumors in whole slide images (WSI) within a preselected hotspot. A second observer performed the same procedures on this cohort. The preselected hotspot was generated by a convolutional neural network (CNN) trained to detect all mitotic figures in digitized hematoxylin and eosin (Hamp;E) sections. The second cohort comprised a multicenter, retrospective TNBC cohort (n = 298), of which the mitotic count was assessed by three independent observers on glass slides. The same CNN was applied on this cohort and the absolute number of mitotic figures in the hotspot was compared to the averaged mitotic count of the observers. Baseline interobserver agreement for glass slide assessment in cohort A was good (kappa 0.689; 95% CI 0.580-0.799). Using the CNN generated hotspot in WSI, the agreement score increased to 0.814 (95% CI 0.719-0.909). Automated counting by the CNN in comparison with observers counting in the predefined hotspot region yielded an average kappa of 0.724. We conclude that manual mitotic counting is not affected by assessment modality (glass slides, WSI) and that counting mitotic figures in WSI is feasible. Using a predefined hotspot area considerably improves reproducibility. Also, fully automated assessment of mitotic score appears to be feasible without introducing additional bias or variability.
  •  
8.
  •  
9.
  • Carneiro, Ana, et al. (författare)
  • Indistinguishable genomic profiles and shared prognostic markers in undifferentiated pleomorphic sarcoma and leiomyosarcoma: different sides of a single coin?
  • 2009
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 1530-0307 .- 0023-6837. ; 89, s. 668-675
  • Tidskriftsartikel (refereegranskat)abstract
    • Soft tissue sarcoma (STS) diagnostics and prognostics are challenging, particularly in highly malignant and pleomorphic subtypes such as undifferentiated pleomorphic sarcoma (UPS) and leiomyosarcoma (LMS). We applied 32K BAC arrays and gene expression profiling to 18 extremity soft tissue LMS and 31 extremity soft tissue UPS with the aim of identifying molecular subtype signatures and genomic prognostic markers. Both the gains/losses and gene expression signatures revealed striking similarities between UPS and LMS, which were indistinguishable using unsupervised hierarchical cluster analysis and significance analysis for microarrays. Gene expression analysis revealed just nine genes, among them tropomyosin beta, which were differentially expressed. Loss of 4q31 (encompassing the SMAD1 locus), loss of 18q22, and tumor necrosis were identified as independent predictors of metastasis in multivariate stepwise Cox regression analysis. Combined analysis applying loss of 4q31 and 18q22 and the presence of necrosis improved the area under receiver operating characteristic curve for metastasis prediction from 0.64 to 0.86. The extensive genetic similarities between extremity soft tissue UPS and LMS suggest a shared lineage of these STS subtypes and the new and independent genetic prognosticators identified hold promise for refined prognostic determination in high-grade, genetically complex STS.Laboratory Investigation advance online publication, 16 March 2009; doi:10.1038/labinvest.2009.18.
  •  
10.
  •  
11.
  • Dave, Vivek Priy, et al. (författare)
  • MicroRNA amplification and detection technologies : opportunities and challenges for point of care diagnostics
  • 2018
  • Ingår i: Laboratory Investigation. - : Nature Publishing Group. - 0023-6837 .- 1530-0307. ; 99:4, s. 452-469
  • Forskningsöversikt (refereegranskat)abstract
    • The volume of point of care (POC) testing continues to grow steadily due to the increased availability of easy-to-use devices, thus making it possible to deliver less costly care closer to the patient site in a shorter time relative to the central laboratory services. A novel class of molecules called microRNAs have recently gained attention in healthcare management for their potential as biomarkers for human diseases. The increasing interest of miRNAs in clinical practice has led to an unmet need for assays that can rapidly and accurately measure miRNAs at the POC. However, the most widely used methods for analyzing miRNAs, including Northern blot-based platforms, in situ hybridization, reverse transcription qPCR, microarray, and next-generation sequencing, are still far from being used as ideal POC diagnostic tools, due to considerable time, expertize required for sample preparation, and in terms of miniaturizations making them suitable platforms for centralized labs. In this review, we highlight various existing and upcoming technologies for miRNA amplification and detection with a particular emphasis on the POC testing industries. The review summarizes different miRNA targets and signals amplification-based assays, from conventional methods to alternative technologies, such as isothermal amplification, paper-based, oligonucleotide-templated reaction, nanobead-based, electrochemical signaling-based, and microfluidic chip-based strategies. Based on critical analysis of these technologies, the possibilities and feasibilities for further development of POC testing for miRNA diagnostics are addressed and discussed.
  •  
12.
  •  
13.
  • Drake, Marcus J, et al. (författare)
  • Structural and functional denervation of human detrusor after spinal cord injury.
  • 2000
  • Ingår i: Laboratory Investigation. - : Nature Publishing Group. - 0023-6837 .- 1530-0307. ; 80:10, s. 1491-9
  • Tidskriftsartikel (refereegranskat)abstract
    • The bladder receives an extensive nerve supply that is predominantly cholinergic, but several putative transmitters are present, some of which are colocalized. Previous studies have shown increased levels of sensory nerves, reduced inhibitory transmitters, and structural and functional changes in the excitatory input in unstable bladder conditions. The present study compared the end-organ nerve supply to the bladder in spinal cord injury (SCI) with uninjured controls. Acetylcholinesterase histochemistry and double-label immunofluorescence were used to investigate neurotransmitter content, with confocal laser scanning microscopy to assess colocalization. Organ bath studies provided functional correlates for the structural changes in the excitatory innervation. Control samples had dense innervation of the detrusor containing a diverse range of transmitters. Hyperreflexic SCI samples showed patchy denervation, and areflexic SCI samples were diffusely denervated. Vasoactive intestinal polypeptide-, neuropeptide Y-, neuronal nitric oxide synthase-, and galanin-immunoreactive nerve fibers were reduced from frequent or moderately frequent to infrequent or very infrequent in SCI. Calcitonin gene-related peptide-immunoreactive fibers were infrequent in controls and SCI samples. Patterns of colocalization were unchanged, but significantly fewer fibers expressed more than one transmitter. The subepithelial plexus was markedly reduced and several of the smaller coarse nerve trunks showed no immunoreactivity to the transmitters assessed. There was no reduction in sensitivity to electrical field stimulation of intrinsic nerves in SCI, but the maximum force generated by each milligram of bladder tissue and the peak force as a proportion of the maximum carbachol contraction were significantly reduced and the responses were protracted. There was no significant functional atropine-resistant neuromuscular transmission in controls or SCI. The reported findings have clinical implications in the management of chronic SCI and development of new treatments.
  •  
14.
  •  
15.
  •  
16.
  • Ekman, Mari, et al. (författare)
  • HIF-mediated metabolic switching in bladder outlet obstruction mitigates the relaxing effect of mitochondrial inhibition.
  • 2014
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 1530-0307 .- 0023-6837. ; 94:5, s. 557-568
  • Tidskriftsartikel (refereegranskat)abstract
    • Prior work demonstrated increased levels of hypoxia-inducible factor-1α (HIF-1α) in the bladder following outlet obstruction, associated with bladder growth and fibrosis. Here we hypothesized that HIF induction in outlet obstruction also switches energetic support of contraction from mitochondrial respiration to glycolysis. To address this hypothesis, we created infravesical outlet obstruction in female Sprague-Dawley rats and examined HIF induction and transcriptional activation. HIF-1α increased after 6 weeks of outlet obstruction as assessed by western blotting and yet transcription factor-binding site analysis indicated HIF activation already at 10 days of obstruction. Accumulation HIF-2α and of Arnt2 proteins were found at 10 days, providing an explanation for the lack of correlation between HIF-1α protein and transcriptional activation. HIF signature targets, including Slc2a1, Tpi1, Eno1 and Ldha increased in obstructed compared with sham-operated bladders. The autophagy markers Bnip3 and LC3B-II were also increased at 6 week of obstruction, but electron microscopy did not support mitophagy. Mitochondria were, however, remodeled with increased expression of Cox4 compared with other markers. In keeping with a switch toward glycolytic support of contraction, we found that relaxation by the mitochondrial inhibitor cyanide was reduced in obstructed bladders. This was mimicked by organ culture with the HIF-inducer dimethyloxalylglycine, which also upregulated expression of Ldha. On the basis of these findings, we conclude that HIF activation in outlet obstruction involves mechanisms beyond the accumulation of HIF-1α protein and that it results in a switch of the energetic support of contraction to anaerobic glycolysis. This metabolic adaptation encompasses increased expression of glucose transporters and glycolytic enzymes combined with mitochondrial remodeling. Together, these changes uphold contractility when mitochondrial respiration is limited.Laboratory Investigation advance online publication, 3 March 2014; doi:10.1038/labinvest.2014.48.
  •  
17.
  • Falkeholm, L, et al. (författare)
  • Xylene-free method for histological preparation : A multicentre evaluation
  • 2001
  • Ingår i: Laboratory Investigation. - 0023-6837 .- 1530-0307. ; 81:9, s. 1213-1221
  • Tidskriftsartikel (refereegranskat)abstract
    • The backbone of daily pathological diagnostic work is the paraffin section. Paraffin sections are still prepared by methods largely unchanged for over 150 years. A xylene-free method has been developed that excludes xylene, not only as the intermediate step before the paraffin baths, but also for deparaffinizing of the cut sections, which also eliminates the need for rehydration and dehydration for the staining and mounting steps. Elimination of xylene from tissue processing cuts costs, saves time, and improves the laboratory environment. Experience with xylene-free sections since 1995 at the Vrinnevi Hospital is favorable. Our opinion is that the xylene-free sections are equivalent to conventionally processed sections. To test this hypothesis, nine pathologists from three hospitals participated in an evaluation trial. Paired tissue blocks from 10 consecutively submitted samples each of breast, intestine, and skin were processed by either the xylene-free or the conventional method. Sections from each block were deparaffinized and stained with hematoxylin-eosin (H&E), with periodic acid-Schiff (PAS), and with van Gieson's method. A randomized mix of 180 sections (10 samples x 3 tissues x 3 stains x 2) gave 90 matched pairs. Each section was blindly examined and scored by nine pathologists to give 810 paired observations for statistical evaluation. The xylene-free sections were ranked as good as or better than their conventional counterparts in 74% of the comparisons, and poorer in 26%. The major discriminating factor was the staining method. H&E and PAS sections were equivalent. The xylene-free van Gieson sections, cut from the same blocks and randomly assigned to this stain, tended to be downgraded. This could be traced to a faulty stain solution used for this batch. The overall results have demonstrated professional acceptance for the xylene-free method of processing histological sections.
  •  
18.
  • Fitchev, Philip P, et al. (författare)
  • Thrombospondin-1 regulates the normal prostate in vivo through angiogenesis and TGF-beta activation
  • 2010
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 0023-6837 .- 1530-0307. ; 90:7, s. 1078-1090
  • Tidskriftsartikel (refereegranskat)abstract
    • Castration experiments in rodents show that the stromal vasculature is critical to the androgen-mediated prostate growth regulation. However, the role of angiogenesis inhibitors, such as thrombospondin-1 (TSP-1), in this process is unclear. TSP-1 is a multifunctional glycoprotein that can function as a potent angiogenesis inhibitor and an in vivo activator of latent transforming growth factor-beta (TGF-beta) in some tissues. On the basis of these observations, we hypothesized that TSP-1 regulated androgen withdrawal-induced prostate regression and that this process was mediated not only through antiangiogenic activity but also through TGF-beta activation. To test this, we evaluated angiogenic activity in human prostate epithelial and stromal cells treated with androgens and hypoxia in vitro. TSP-1 knockout mice were characterized to investigate the in vivo functions of TSP-1. In vitro, we found that androgens and hypoxia differentially regulated TSP-1 and angiogenic activity. Androgens stimulated normal epithelial cell, but inhibited normal stromal cell, angiogenic activity. Conversely, hypoxia stimulated stromal while inhibiting epithelial activity. Thus, in vivo, net angiogenic activity must reflect cellular interactions. And, we found that media conditioned by epithelial cells grown under normoxic conditions stimulated stromal cell angiogenic activity, and if epithelial cells were grown under hypoxic conditions, stromal activity was further increased. TSP-1 levels, however, were unchanged. In vivo, TSP-1 loss in a mouse model led to prostate epithelial hyperplasia by 3 months of age with only a modest stromal effect. Androgens suppressed TSP-1 as expression increased after castration both in normal mouse prostate and in human prostate cancer tissues. In addition, TSP-1 expression corresponded to increased TGF-beta activation in mouse tissues, specifically in the stromal compartment. These data show a critical role for TSP-1 in prostate epithelial and stromal growth regulation through angiogenic inhibition and activation of latent TGF-beta. Therefore, loss of TSP-1 during tumorigenesis would eliminate two barriers to cancer progression.
  •  
19.
  • Gestblom, C, et al. (författare)
  • The basic helix-loop-helix transcription factor dHAND, a marker gene for the developing human sympathetic nervous system, is expressed in both high- and low-stage neuroblastomas
  • 1999
  • Ingår i: Laboratory Investigation. - 1530-0307 .- 0023-6837. ; 79, s. 67-
  • Tidskriftsartikel (refereegranskat)abstract
    • Neuroblastoma is derived from the sympathetic nervous system and might arise as a result of impaired differentiation, retaining the neuroblastic tumor cells in the cell cycle. Thus, to understand the genesis of neuroblastoma, the study of mechanisms and genes regulating normal sympathetic development is of potential interest. The basic helix-loop-helix transcription factors human achaete-scute homolog-1 (HASH-1) and deciduum, heart, autonomic nervous system, and neural crest derivatives (dHAND) are expressed in the sympathetic nervous system of embryonic mice and chicken, with undetectable postnatal expression. By in situ hybridization technique, we show that dHAND was expressed by human sympathetic neuronal and extra-adrenal chromaffin cells throughout embryonic and fetal life, and was initially expressed in immature chromaffin cells of the adrenal gland. With overt chromaffin differentiation, dHAND was down-regulated. HASH-1, in contrast, was expressed in human sympathetic cells only at the earliest embryonic ages examined (Week 6.5 to 7). All examined neuroblastoma specimens (25/25) and all cell lines (5/5) had detectable dHAND mRNA levels. HASH-1 expression in tumor specimens was more restricted, although all cell lines (5/5) were HASH-1-positive. These results show that neuroblastoma tumors have retained embryonic features, suggesting that many neuroblastomas are blocked at an early stage of normal development when HASH-1 and dHAND are expressed. dHAND also appears to be a reliable and potentially useful clinical diagnostic marker for neuroblastoma, because expression was not dependent on tumor or differentiation stages and other pediatric tumors were dHAND-negative.
  •  
20.
  • Gharizadeh, B., et al. (författare)
  • Typing of human papillomavirus by pyrosequencing
  • 2001
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 0023-6837 .- 1530-0307. ; 81:5, s. 673-679
  • Tidskriftsartikel (refereegranskat)abstract
    • The possibility of using a new bioluminometric UNA sequencing technique, called pyrosequencing, for typing of human papillomaviruses (HPV) was investigated. A blinded pyrosequencing test was performed on an HPV test panel of 67 GP5+/GP6+ PCR-derived amplification products. The 67 clinical DNA samples were sequenced up to 25 bases and sequences were searched using BLAST. All of the samples were correctly genotyped by pyrosequencing and the results were unequivocally in accordance with the results obtained from conventional DNA sequencing. Pyrosequencing was found to be a fast and efficient tool for identifying individual HPV types. Furthermore, pyrosequencing has the capability of determining novel HPV types as well as HPV sequence variants harboring mutation(s). The method is robust and well suited for large-scale programs.
  •  
21.
  • Gullberg, Elisabet, et al. (författare)
  • Yersinia pseudotuberculosis induces transcytosis of nanoparticles across human intestinal villus epithelium via invasin-dependent macropinocytosis
  • 2008
  • Ingår i: Laboratory investigation; a journal of technical methods and pathology. - New York, USA : Elsevier BV. - 1530-0307 .- 0023-6837. ; 88:11, s. 1215-26
  • Tidskriftsartikel (refereegranskat)abstract
    • Crohn's disease is characterized by a defect in intestinal barrier function, where bacteria are considered the most important inflammation-driving factor. Enteric bacteria, including E. coli and Yersinia spp, affect tight junctions in enterocytes, but little is known about bacterial effects on the transcellular pathway. Our objective was to study the short-term effects of Y. pseudotuberculosis on uptake of nanoparticles across human villus epithelium. Monolayers of human colon epithelium-derived Caco-2 cells and biopsies of normal human ileum were studied after 2 h exposure to Y. pseudotuberculosis expressing (inv+) or lacking (inv-) the bacterial adhesion molecule, invasin. Transepithelial transport of fluorescent nanoparticles (markers of transcytosis) was quantified by flow cytometry, and mechanisms explored by using inhibitors of endocytosis. Epithelial expressions of beta1-integrin and particle uptake pathways were studied by confocal microscopy. The paracellular pathway was assessed by electrical resistance (TER), mannitol flux, and expression of tight junction proteins occludin and caludin-4 by confocal microscopy. Inv+ Y. pseudotuberculosis adhered to the apical surface of epithelial cells and induced transcytosis of exogenous nanoparticles across Caco-2 monolayers (30-fold increase, P<0.01) and ileal mucosa (268+/-47% of control; P<0.01), whereas inv bacteria had no effect on transcytosis. The transcytosis was concentration-, particle size- and temperature-dependent, and possibly mediated via macropinocytosis. Y. pseudotuberculosis also induced apical expression of beta1-integrin on epithelial cells. A slight drop in TER was seen after exposure to inv+ Y. pseudotuberculosis, whereas mannitol flux and tight junction protein expression was unchanged. In summary, Y. pseudotuberculosis induced apical expression of beta1-integrin and stimulated uptake of nanoparticles via invasin-dependent transcytosis in human intestinal epithelium. Our findings suggest that bacterial factors may initiate transcytosis of luminal exogenous particles across human ileal mucosa, thus presenting a novel mechanism of intestinal barrier dysfunction.
  •  
22.
  • Hermsen, Meyke, et al. (författare)
  • Quantitative assessment of inflammatory infiltrates in kidney transplant biopsies using multiplex tyramide signal amplification and deep learning
  • 2021
  • Ingår i: Laboratory Investigation. - : Springer Nature. - 0023-6837 .- 1530-0307. ; 101:8, s. 970-982
  • Tidskriftsartikel (refereegranskat)abstract
    • Delayed graft function (DGF) is a strong risk factor for development of interstitial fibrosis and tubular atrophy (IFTA) in kidney transplants. Quantitative assessment of inflammatory infiltrates in kidney biopsies of DGF patients can reveal predictive markers for IFTA development. In this study, we combined multiplex tyramide signal amplification (mTSA) and convolutional neural networks (CNNs) to assess the inflammatory microenvironment in kidney biopsies of DGF patients (n = 22) taken at 6 weeks post-transplantation. Patients were stratified for IFTA development (<10% versus >= 10%) from 6 weeks to 6 months post-transplantation, based on histopathological assessment by three kidney pathologists. One mTSA panel was developed for visualization of capillaries, T- and B-lymphocytes and macrophages and a second mTSA panel for T-helper cell and macrophage subsets. The slides were multi spectrally imaged and custom-made python scripts enabled conversion to artificial brightfield whole-slide images (WSI). We used an existing CNN for the detection of lymphocytes with cytoplasmatic staining patterns in immunohistochemistry and developed two new CNNs for the detection of macrophages and nuclear-stained lymphocytes. F1-scores were 0.77 (nuclear-stained lymphocytes), 0.81 (cytoplasmatic-stained lymphocytes), and 0.82 (macrophages) on a test set of artificial brightfield WSI. The CNNs were used to detect inflammatory cells, after which we assessed the peritubular capillary extent, cell density, cell ratios, and cell distance in the two patient groups. In this cohort, distance of macrophages to other immune cells and peritubular capillary extent did not vary significantly at 6 weeks post-transplantation between patient groups. CD163(+) cell density was higher in patients with >= 10% IFTA development 6 months post-transplantation (p < 0.05). CD3(+)CD8(-)/CD3(+)CD8(+) ratios were higher in patients with <10% IFTA development (p < 0.05). We observed a high correlation between CD163(+) and CD4(+)GATA3(+) cell density (R = 0.74, p < 0.001). Our study demonstrates that CNNs can be used to leverage reliable, quantitative results from mTSA-stained, multi spectrally imaged slides of kidney transplant biopsies. This study describes a methodology to assess the microenvironment in sparse tissue samples. Deep learning, multiplex immunohistochemistry, and mathematical image processing techniques were incorporated to quantify lymphocytes, macrophages, and capillaries in kidney transplant biopsies of delayed graft function patients. The quantitative results were used to assess correlations with development of interstitial fibrosis and tubular atrophy.
  •  
23.
  • Hofvander, Jakob, et al. (författare)
  • RNA sequencing of sarcomas with simple karyotypes: identification and enrichment of fusion transcripts.
  • 2015
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 1530-0307 .- 0023-6837. ; 95:6, s. 603-609
  • Tidskriftsartikel (refereegranskat)abstract
    • Gene fusions are neoplasia-associated mutations arising from structural chromosomal rearrangements. They have a strong impact on tumor development and constitute important diagnostic markers. Malignant soft tissue tumors (sarcomas) constitute a heterogeneous group of neoplasms with >50 distinct subtypes, each of which is rare. In addition, there is considerable morphologic overlap between sarcomas and benign lesions. Several subtypes display distinct gene fusions, serving as excellent biomarkers. The development of methods for deep sequencing of the complete transcriptome (RNA-Seq) has substantially improved the possibilities for detecting gene fusions. With the aim of identifying new gene fusions of biological and clinical relevance, eight sarcomas with simple karyotypes, ie, only one or a few structural rearrangements, were subjected to massively parallel paired-end sequencing of mRNA. Three different algorithms were used to identify fusion transcripts from RNA-Seq data. Three novel (KIAA2026-NUDT11, CCBL1-ARL1, and AFF3-PHF1) and two previously known fusions (FUS-CREB3L2 and HAS2-PLAG1) were found and could be verified by other methods. These findings show that RNA-Seq is a powerful tool for detecting gene fusions in sarcomas but also suggest that it is advisable to use more than one algorithm to analyze the output data as only two of the confirmed fusions were reported by more than one of the gene fusion detection software programs. For all of the confirmed gene fusions, at least one of the genes mapped to a chromosome band implicated by the karyotype, suggesting that sarcomas with simple karyotypes constitute an excellent resource for identifying novel gene fusions.Laboratory Investigation advance online publication, 13 April 2015; doi:10.1038/labinvest.2015.50.
  •  
24.
  • Hwaiz, Rundk, et al. (författare)
  • Rac1 regulates platelet shedding of CD40L in abdominal sepsis.
  • 2014
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 1530-0307 .- 0023-6837. ; 94:9, s. 1054-1063
  • Tidskriftsartikel (refereegranskat)abstract
    • Matrix metalloproteinase-9 (MMP-9) regulates platelet shedding of CD40L in abdominal sepsis. However, the signaling mechanisms controlling sepsis-induced shedding of CD40L from activated platelets remain elusive. Rac1 has been reported to regulate diverse functions in platelets; we hypothesized herein that Rac1 might regulate platelet shedding of CD40L in sepsis. The specific Rac1 inhibitor NSC23766 (N6-[2-[[4-(diethylamino)-1-methylbutyl] amino]-6-methyl-4-pyrimidinyl]-2 methyl-4, 6-quinolinediamine trihydrochloride) was administered to mice undergoing cecal ligation and puncture (CLP). Levels of CD40L and MMP-9 in plasma, platelets, and neutrophils were determined by use of ELISA, western blot, and confocal microscopy. Platelet depletion abolished the CLP-induced increase in plasma levels of CD40L. Rac1 activity was significantly increased in platelets from septic animals. Administration of NSC23766 abolished the CLP-induced enhancement of soluble CD40L levels in the plasma. Moreover, Rac1 inhibition completely inhibited proteinase-activated receptor-4-induced surface mobilization and secretion of CD40L in isolated platelets. CLP significantly increased plasma levels of MMP-9 and Rac1 activity in neutrophils. Treatment with NSC23766 markedly attenuated MMP-9 levels in the plasma from septic mice. In addition, Rac1 inhibition abolished chemokine-induced secretion of MMP-9 from isolated neutrophils. Finally, platelet shedding of CD40L was significantly reduced in response to stimulation with supernatants from activated MMP-9-deficient neutrophils compared with supernatants from wild-type neutrophils, indicating a direct role of neutrophil-derived MMP-9 in regulating platelet shedding of CD40L. Our novel data suggest that sepsis-induced platelet shedding of CD40L is dependent on Rac1 signaling. Rac1 controls surface mobilization of CD40L on activated platelets and MMP-9 secretion from neutrophils. Thus, our findings indicate that targeting Rac1 signaling might be a useful way to control pathologic elevations of CD40L in the systemic circulation in abdominal sepsis.Laboratory Investigation advance online publication, 21 July 2014; doi:10.1038/labinvest.2014.92.
  •  
25.
  • Itoh, Fumiko, et al. (författare)
  • Poor vessel formation in embryos from knock-in mice expressing ALK5 with L45 loop mutation defective in Smad activation
  • 2009
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 1530-0307 .- 0023-6837. ; 89:7, s. 800-810
  • Tidskriftsartikel (refereegranskat)abstract
    • Transforming growth factor (TGF)-beta regulates vascular development through two type I receptors: activin receptor-like kinase (ALK) 1 and ALK5, each of which activates a different downstream Smad pathway. The endothelial cell (EC)-specific ALK1 increases EC proliferation and migration, whereas the ubiquitously expressed ALK5 inhibits both of these processes. As ALK1 requires the kinase activity of ALK5 for optimal activation, the lack of ALK5 in ECs results in defective phosphorylation of both Smad pathways on TGF-beta stimulation. To understand why TGF-beta signaling through ALK1 and ALK5 has opposing effects on ECs and whether this takes place in vivo, we carefully compared the phenotype of ALK5 knock-in (ALK5(KI/KI)) mice, in which the aspartic acid residue 266 in the L45 loop of ALK5 was replaced by an alanine residue, with the phenotypes of ALK5 knock-out (ALK5(-/-)) and wild-type mice. The ALK5(KI/KI) mice showed angiogenic defects with embryonic lethality at E10.5-11.5. Although the phenotype of the ALK5(KI/KI) mice was quite similar to that of the ALK5(-/-) mice, the hierarchical structure of blood vessels formed in the ALK5(KI/KI) embryos was more developed than that in the ALK5(-/-) mutants. Thus, the L45 loop mutation in ALK5 partially rescued the earliest vascular defects in the ALK5(-/-) embryos. This study supports our earlier observation that vascular maturation in vivo requires both TGF-beta/ALK1/BMP-Smad and TGF-beta/ALK5/activin-Smad pathways for normal vascular development. Laboratory Investigation (2009) 89, 800-810; doi:10.1038/labinvest.2009.37; published online 27 April 2009
  •  
26.
  •  
27.
  • Kallionpaa, Roope A., et al. (författare)
  • Characterization of Immune Cell Populations of Cutaneous Neurofibromas in Neurofibromatosis 1
  • 2024
  • Ingår i: LABORATORY INVESTIGATION. - 0023-6837 .- 1530-0307. ; 104:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Cutaneous neurofibromas (cNFs) are characteristic of neurofibromatosis 1 (NF1), yet their immune microenvironment is incompletely known. A total of 61 cNFs from 10 patients with NF1 were immunolabeled for different types of T cells and macrophages, and the cell densities were correlated with clinical characteristics. Eight cNFs and their overlying skin were analyzed for T cell receptor CDR domain sequences, and mass spectrometry of 15 cNFs and the overlying skin was performed to study immune-related processes. Intratumoral T cells were detected in all cNFs. Tumors from individuals younger than the median age of the study participants (33 years), growing tumors, and tumors smaller than the data set median showed increased T cell density. Most samples displayed intratumoral or peritumoral aggregations of CD3-positive cells. T cell receptor sequencing demonstrated that the skin and cNFs host distinct T cell populations, whereas no dominant cNF-specific T cell clones were detected. Unique T cell clones were fewer in cNFs than in skin, and mass spectrometry suggested lower expression of proteins related to T cell-mediated immunity in cNFs than in skin. CD163-positive cells, suggestive of M2 macrophages, were abundant in cNFs. Human cNFs have substantial T cell and macrophage populations that may be tumorspecific.
  •  
28.
  • Keita, Åsa V, et al. (författare)
  • Characterization of antigen and bacterial transport in the follicle-associated epithelium of human ileum
  • 2006
  • Ingår i: Laboratory investigation. - : Elsevier BV. - 0023-6837 .- 1530-0307. ; 86:5, s. 504-516
  • Tidskriftsartikel (refereegranskat)abstract
    • The follicle-associated epithelium (FAE), covering Peyer's patches, provides a route of entry for antigens and microorganisms. Animal studies showed enhanced antigen and bacterial uptake in FAE, but no study on barrier function of human FAE has been reported. Our aim was to characterize the normal barrier properties of human FAE. Specimens of normal ileum were taken from 30 patients with noninflammatory colonic disease. Villus epithelium (VE) and FAE were identified and mounted in Ussing chambers. Permeability to 51Cr-EDTA, transmucosal flux of the protein antigen, horseradish peroxidase (HRP), and transport of fluorescent Escherichia coli (chemically killed K-12 and live HB101) were measured. Uptake mechanisms were studied by confocal- and transmission electron microscopy, and by using pharmacological inhibitors in an in vitro coculture model of FAE and in human ileal FAE. HRP flux was substantially higher in FAE than in VE, and was reduced by an amiloride analog. Electron microscopy showed HRP-containing endosomes. Transport of E. coli K-12 and HB101 was also augmented in FAE and was confirmed by confocal microscopy. In vitro coculture experiments and electron microscopy revealed actin-dependent, mainly transcellular, uptake of E. coli K-12 into FAE. 51Cr-EDTA permeability was equal in FAE and VE. Augmented HRP flux and bacterial uptake but similar paracellular permeability, suggest functional variations of transcellular transport in the FAE. We show for the first time that FAE of human ileum is functionally distinct from regular VE, rendering the FAE more prone to bacterial–epithelial cell interactions and delivery of antigens to the mucosal immune system.
  •  
29.
  • Kilarski, Witold W., et al. (författare)
  • An ex vivo model for functional studies of myofibroblasts
  • 2005
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 0023-6837 .- 1530-0307. ; 85:5, s. 643-54
  • Tidskriftsartikel (refereegranskat)abstract
    • Migration, proliferation and invasive growth of myofibroblasts are key cellular events during formation of granulation tissue in situations of wound healing, arteriosclerosis and tumor growth. To study the invasive phenotype of myofibroblasts, we established an assay where arterial tissue from chicken embryos was embedded in fibrin gels and stimulated with growth factors. Addition of serum, PDGF-BB and FGF-2, but not VEGF-A, resulted in an outgrowth of cellular sprouts with a pattern that was similar to the organization of cells invading a provisional matrix in an in vivo model of wound healing using the chicken chorioallantoic membrane. Sprouting cells were defined as myofibroblasts based on being alpha-smooth muscle actin-positive but desmin-negative. There was no contribution of endothelial cells in outgrowing sprouts. The acquired myofibroblastic phenotype was stable since sprout-derived cells resumed sprouting in a growth factor-independent manner when re-embedded as spheroids in a fibrin matrix. Invasive growth and sprouting of vascular smooth muscle cells was not limited to chicken cells since a similar response was seen when spheroids composed of purified primary human aortic smooth muscle cells were embedded in fibrin. Finally, a technique for flat visualization of the three-dimensional sprouting and a quantification method is described. This ex vivo model allows quantitative analysis of invasive growth and differentiation of vascular smooth muscle cells and fibroblasts into myofibroblasts.
  •  
30.
  • Krampert, Monika, et al. (författare)
  • A gain-of-function mutation in the PDGFR-beta alters thekinetics of injury response in liver and skin
  • 2008
  • Ingår i: Laboratory Investigation. - : USCAP. - 0023-6837 .- 1530-0307. ; 88:11, s. 1204-1214
  • Tidskriftsartikel (refereegranskat)abstract
    • Platelet-derived growth factor (PDGF) isoforms stimulate cell proliferation, migration and survival. We recently generated mice carrying a gain-of-function mutation within the activation loop of PDGF beta-receptor (PDGFR-beta D849N). Embryonic fibroblasts derived from these mice show elevated basal phosphorylation and altered kinetics for ligand-induced activation of PDGFR-beta, as well as enhanced proliferation and migration. To investigate the effect of this mutation in vivo, we used carbon tetrachloride-induced liver injury as a model system. We observed a higher basal activation of mutant PDGFR-beta in unchallenged livers; however, the difference in activation upon carbon tetrachloride stimulation was lower than expected, an effect that might be explained by a delayed response of the mutated receptor toward reactive oxygen species. Mutant mice showed enhanced proliferation of nonparenchymal liver cells and activation of hepatic stellate cells, leading to a small increase in early fibrosis formation. Another mouse strain lacking the binding site for phosphatidylinositol-3' kinase in PDGFR-beta showed the reverse phenotype. These results suggest an important role for PDGFR-beta signaling in the early injury-response. We confirmed this hypothesis with a second injury model, cutaneous wound healing, where we observed earlier proliferation and formation of granulation tissue in D849N-mutant mice.  
  •  
31.
  • Lennikov, Anton, et al. (författare)
  • Deficiency of C-X-C chemokine receptor type 5 (CXCR5) gene causes dysfunction of retinal pigment epithelium cells
  • 2021
  • Ingår i: Laboratory Investigation. - : SPRINGERNATURE. - 0023-6837 .- 1530-0307. ; 101, s. 228-244
  • Tidskriftsartikel (refereegranskat)abstract
    • Homeostasis of the retinal pigment epithelium (RPE) is essential for the health and proper function of the retina. Regulation of RPE homeostasis is, however, largely unexplored, yet dysfunction of this process may lead to retinal degenerative diseases, including age-related macular degeneration (AMD). Here, we report that chemokine receptor CXCR5 regulates RPE homeostasis through PI3K/AKT signaling and by suppression of FOXO1 activation. We used primary RPE cells isolated from CXCR5-deficient mice and wild type controls, as well as ex vivo RPE-choroidal-scleral complexes (RCSC) to investigate the regulation of homeostasis. CXCR5 expression in mouse RPE cells was diminished by treatment with hydrogen peroxide. Lack of CXCR5 expression leads to an abnormal cellular shape, pigmentation, decreased expression of the RPE differentiation marker RPE65, an increase in the undifferentiated progenitor marker MITF, and compromised RPE barrier function, as well as compromised cell-to-cell interaction. An increase in epithelial-mesenchymal transition (EMT) markers (alpha SMA, N-cadherin, and vimentin) was noted in CXCR5-deficient RPE cells both in vitro and in age-progression specimens of CXCR5(-/-)mice (6, 12, 24-months old). Deregulated autophagy in CXCR5-deficient RPE cells was observed by decreased LC3B-II, increased p62, abnormal autophagosomes, and impaired lysosome enzymatic activity as shown by GFP-LC3-RFP reporter plasmid. Mechanistically, deficiency in CXCR5 resulted in the downregulation of PI3K and AKT signaling, but upregulation and nuclear localization of FOXO1. Additionally, inhibition of PI3K in RPE cells resulted in an increased expression of FOXO1. Inhibition of FOXO1, however, reverts the degradation of ZO-1 caused by CXCR5 deficiency. Collectively, these findings suggest that CXCR5 maintains PI3K/AKT signaling, which controls FOXO1 activation, thereby regulating the expression of genes involved in RPE EMT and autophagy deregulation. C-X-C chemokine receptor type 5 (CXCR5) regulates retinal pigment epithelium (RPE) homeostasis through PI3K/AKT signaling and by suppression of FOXO1 activation. CXCR5-deficency leads to decreased RPE differentiation, compromised barrier function, and increase in epithelial-mesenchymal transition markers (alpha SMA, N-cadherin, and vimentin) in CXCR5-deficient RPE cells in vitro and in CXCR5(-/-)mice.
  •  
32.
  • Lindmark, G, et al. (författare)
  • Stromal expression of platelet-derived growth factor beta-receptor and platelet-derived growth factor B-chain in colorectal cancer.
  • 1993
  • Ingår i: Laboratory Investigation. - 0023-6837 .- 1530-0307. ; 69:6, s. 682-9
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: The importance of growth factors, such as platelet-derived growth factor (PDGF), for stromal activation in colorectal cancer is unclear.EXPERIMENTAL DESIGN: The expression of beta-receptors for PDGF, and PDGF B-chain (PDGF AB and PDGF BB) was investigated by immunohistologic techniques in full-thickness biopsies from 210 colorectal cancers. These antigens were detected by the monoclonal antibodies PDGFR-B2 and PDGF 007, respectively.RESULTS: All tumors contained granular clusters of PDGF beta-receptor expressing stromal cells, whereas tumor epithelium was invariably negative. The staining was most prominent in vascular cells. There were several cells in the tumor stroma that expressed PDGF AB/BB. Double immunofluorescence stainings in specimens from four patients performed in order to characterize PDGF beta-receptor- and PDGF AB/BB expressing cells showed that cells expressing PDGF beta-receptors did not express PDGF AB/BB. About 20% of cells in the stroma expressing PDGF AB/BB were macrophages (CD68-positive cells), whereas the nature of the remaining stromal cells expressing PDGF AB/BB could not be disclosed. Furthermore, about 30% of CD68-positive macrophages expressed PDGF AB/BB, but not PDGF beta-receptors. The extent of clusters of PDGF beta-receptor expressing cells varied considerably between tumors, and its prognostic value was considered in the entire tumor material. The number of clusters did, however, not correlate to tumor differentiation, tumor stage according to Dukes', or outcome.CONCLUSIONS: The presence of cells expressing PDGF beta-receptor and PDGF AB/BB respectively, i.e., expression of the receptor and its ligand, fulfills two of the prerequisites for a role of PDGF in the activation of stromal cells in colorectal cancers. The data suggest that stromal activation, characterized by clusters of PDGF beta-receptor expressing cells, is of importance for the formation of tumor stroma per se. However, the expression of the PDGF beta-receptor has no potential as a prognostic marker.
  •  
33.
  • Lundberg, C, et al. (författare)
  • Inflammatory reaction in an experimental model of open wounds in the rat. The role of polymorphonuclear leukocytes.
  • 1984
  • Ingår i: Laboratory Investigation. - 0023-6837 .- 1530-0307. ; 50:6, s. 726-32
  • Tidskriftsartikel (refereegranskat)abstract
    • The accumulation of polymorphonuclear leukocytes (PMNLs) and the concentration of prostaglandin E2 in full thickness open skin wounds, created in the back of the rat, were studied. The quantity of PMNLs in the granulation tissue, assessed by analysis of wound exudate myeloperoxidase activity, increased from 0.45 units/ml on day 1 after wounding to 0.8 units/ml on day 2 and then remained constant throughout the 5 days of observation. The prostaglandin E2 concentration in wound exudate was measured by radioimmunoassay increased progressively from 70 ng/ml on day 1 to 290 ng/ml on day 5. The lack of correlation between these two variables indicates that PMNLs were not the major source of prostaglandin E2. To study the relation between PMNL accumulation, blood flow, and albumin extravasation in the granulation tissue, rats were treated with an antineutrophil serum. This resulted in an 83% decrease in circulating PMNLs and a 61% decrease in granulation tissue myeloperoxidase activity on the 5th day, as compared with rats treated with normal rabbit serum. No relationship was observed between myeloperoxidase activity and blood flow (r = 0.37) or between myeloperoxidase activity and albumin extravasation (r = -0.34) when absolute values were compared. However, when interindividual variation in the absolute levels of the variable measured was eliminated, by calculating in each rat a left to right wound ratio, good correlations (r = 0.81 and r = 0.65, respectively) were found. It is suggested that blood flow and albumin extravasation in the granulation tissue are influenced by local PMNL accumulation.
  •  
34.
  •  
35.
  • Macchia, Gemma, et al. (författare)
  • FOSL1 as a candidate target gene for 11q12 rearrangements in desmoplastic fibroblastoma.
  • 2012
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 1530-0307 .- 0023-6837. ; 92:5, s. 735-743
  • Tidskriftsartikel (refereegranskat)abstract
    • Desmoplastic fibroblastoma (DF) is a benign fibroblastic/myofibroblastic tumor. Cytogenetic analyses have revealed consistent rearrangement of chromosome band 11q12, strongly suggesting that this region harbors a gene of pathogenetic importance. To identify the target gene of the 11q12 rearrangements, we analyzed six cases diagnosed as DF using chromosome banding, fluorescence in situ hybridization (FISH), single-nucleotide polymorphism array and gene expression approaches. Different structural rearrangements involving 11q12 were found in five of the six cases. Metaphase FISH analyses in two of them mapped the 11q12 breakpoints to an ∼20-kb region, harboring FOSL1. Global gene expression profiling followed by quantitative real-time PCR showed that FOSL1 was expressed at higher levels in DF with 11q12 rearrangements than in desmoid-type fibromatoses. Furthermore, FOSL1 was not upregulated in the single case of DF that did not show cytogenetic involvement of 11q12; instead this tumor was found to display a hemizygous loss on 5q, including the APC (adenomatous polyposis coli) locus, raising the possibility that it actually was a misdiagnosed Gardner fibroma. 5'RACE-PCR in two 11q12-positive DF did not identify any fusion transcripts. Thus, in agreement with the finding at chromosome banding analysis that varying translocation partners are involved in the 11q12 rearrangement, the molecular data suggest that the functional outcome of the 11q12 rearrangements is deregulated expression of FOSL1.Laboratory Investigation advance online publication, 12 March 2012; doi:10.1038/labinvest.2012.46.
  •  
36.
  •  
37.
  •  
38.
  • Mertens, Fredrik, et al. (författare)
  • Clinicopathologic and molecular genetic characterization of low-grade fibromyxoid sarcoma, and cloning of a novel FUS/CREB3L1 fusion gene
  • 2005
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 1530-0307 .- 0023-6837. ; 85:3, s. 408-415
  • Tidskriftsartikel (refereegranskat)abstract
    • Low-grade fibromyxoid sarcoma (LGFMS) is an indolent, late-metastasizing malignant soft-tissue tumor that is often mistaken for either more benign or more malignant tumor types. Cytogenetic analyses have identified a recurrent balanced translocation t(7;16) (q32-34;p11), later shown by molecular genetic approaches to result in a FUS/CREB3L2 fusion gene. Whereas preliminary studies suggest that this gene rearrangement is specific for LGFMS, its incidence in this tumor type and the possible existence of variant fusion genes have not yet been addressed. For this purpose, a series of potential LGFMS were obtained from nine different soft-tissue tumor centres and subjected to molecular analysis as well as careful histopathologic review. Reverse transcriptase-polymerase chain reaction analysis disclosed a FUS/CREB3L2 fusion transcript in 22 of the 23 (96%) cases that remained classified as LGFMS after the histologic re-evaluation and from which RNA of sufficient quality could be extracted, whereas none of the cases that were classified as other tumor types was fusion-positive. In one of the tumors with typical LGFMS appearance, we found that FUS was fused to the CREB3L1 gene instead of CREB3L2. The proteins encoded by these genes both belong to the same basic leucine-zipper family of transcription factors, and display extensive sequence homology in their DNA-binding domains. Thus, it is expected that the novel FUS/CREB3L1 chimera will have a similar impact at the cellular level as the much more common FUS/CREB3L2 fusion protein. Taken together, the results indicate that virtually all LGFMS are characterized by a chimeric FUS/CREB3L2 gene, and that rare cases may display a variant FUS/CREB3L1 fusion.
  •  
39.
  • Peng, Siwei, et al. (författare)
  • Role of aggregated medin in the pathogenesis of thoracic aortic aneurysm and dissection
  • 2007
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 0023-6837 .- 1530-0307. ; 87:12, s. 1195-1205
  • Tidskriftsartikel (refereegranskat)abstract
    • The pathogenesis of sporadic thoracic aortic aneurysm and dissection, which may lead to rupture of the aorta, remains largely unknown. Amyloid deposits, formed from the medin peptide, are very prevalent in the media of the thoracic aorta. We have studied the occurrence of medin-derived amyloid in specimens from patients with thoracic aortic aneurysm, aortic dissection type A and normal dimensioned aorta. Surprisingly, the amount of amyloid was significantly lower in the aneurysm and dissection groups (0.63+/-0.13 and 0.36+/-0.24 amyloid particles per mm2, respectively) compared to the control material (2.37+/-0.58). However, focal medin immunoreactivity not associated with amyloid was found more conspicuously in the media of the two diseased groups. Recent amyloid research indicates that prefibrillar oligomeric aggregates, rather than mature amyloid fibrils, are toxic to the surrounding cells. The non-amyloid medin immunoreactivity observed may represent such toxic oligomers. This is supported by the fact that aggregated medin induced death of aortic smooth muscle cells in vitro. In addition, cells incubated together with medin increased the production of matrix metalloproteinase-2, a protease that degrades elastin and collagen and subsequently weakens the vessel wall. We therefore propose that medin oligomers are involved in the degeneration process of sporadic thoracic aortic aneurysm and dissection.
  •  
40.
  • Roberg, Karin, 1957- (författare)
  • Relocalization of Cathepsin D and Cytochrome c Early in Apoptosis Revealed by Immunoelectron Microscopy
  • 2001
  • Ingår i: Laboratory Investigation. - 0023-6837 .- 1530-0307. ; 81:2, s. 149-158
  • Tidskriftsartikel (refereegranskat)abstract
    • Cathepsin D was translocated from lysosomal structures to the cytosol in primary cultures of neonatal rat cardiomyocytes exposed to oxidative stress, and these cells underwent apoptotic death during subsequent incubation. Temporal aspects of cathepsin D relocalization, cytochrome c release, and decrease in mitochondrial transmembrane potential (Δψm) were studied in myocytes exposed to the redox-cycling xenobiotic naphthazarin (5,8-dihydroxy-1,4-naphthoquinone). Immunofluorescence labeling revealed that cathepsin D was translocated to the cytosol after 30 minutes of naphthazarin treatment, and cytochrome c was released from mitochondria to the cytosol after 2 hours. Western blotting and immunoelectron microscopy indicated a minor release of cytochrome c after only 30 minutes and 1 hour, respectively. Thereafter, a decrease in Δψm was detected using the Δψm-sensitive dye JC-1 and confocal microscopy, and ultrastructural analysis indicated apoptotic morphology. Pretreatment of the cultures with the cathepsin D inhibitor pepstatin A prevented release of cytochrome c from mitochondria and maintained the Δψm. Moreover, ultrastructural examination showed no apoptotic morphology. These findings suggest that lysosomal destabilization (detected as the release of cathepsin D) and release of cytochrome c from mitochondria take place early in apoptosis. Also, the former event probably occurs before the latter during apoptosis induced by oxidative stress because pretreatment with pepstatin A prevented release of cytochrome c and loss of Δψm in cardiomyocytes exposed to naphthazarin.
  •  
41.
  •  
42.
  •  
43.
  •  
44.
  • Rydell-Törmänen, Kristina, et al. (författare)
  • Extracellular matrix alterations and acute inflammation; developing in parallel during early induction of pulmonary fibrosis.
  • 2012
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 1530-0307 .- 0023-6837. ; 92:6, s. 917-925
  • Tidskriftsartikel (refereegranskat)abstract
    • Pulmonary fibrosis is a hallmark of several systemic diseases such as systemic sclerosis. Initiation and early development is not well characterized, as initiation usually is unnoticed in patients, yet fibrosis has been considered a late event, occurring after an inflammatory phase. By utilizing an animal model, the starting point can be defined and the initiation process and early development thoroughly investigated. To investigate these processes from a systemic perspective, we choose a systemic administration route, instead of the more commonly used local administration. The aim of this work was to study the initiation of pulmonary fibrosis in an animal model and to investigate early alterations in connective tissue, cell turnover and acute immune response in lung parenchyma. Animals were injected subcutaneously with bleomycin, three times a week (w) for 1-4w (controls received saline). Total collagen was histologically assessed by Picro Sirius Red and Masson's Trichrome, collagen production by antibodies directed against N-terminal of procollagens I and III, proliferation by labeling with proliferating cell nuclear antigen, apoptosis by TUNEL and innate immunity by detecting neutrophils and macrophages. Total collagen was significantly increased at 1, 2 and 4w compared with controls. Procollagen I, was increased at 1w and remained increased, whereas procollagen III-staining was increased at 2w, compared with controls. Myofibroblasts were increased at all times as were proliferation, whereas apoptosis was increased from 2w. Neutrophils peaked at 1w (2779±820 cells/mm(2)) and gradually decreased, whereas macrophages peaked at 2w (135±29 cells/mm(2)). Subcutaneously administered bleomycin induces rapid alterations in connective tissue and cell turnover, suggesting a plasticity of the connective tissue. A transient neutrophilia is detected and increased number of macrophages likely represents a clearance process of said neutrophils. The study suggests fibrosis initiation and acute inflammation to occur in parallel in this model.Laboratory Investigation advance online publication, 2 April 2012; doi:10.1038/labinvest.2012.57.
  •  
45.
  • Salnikov, Alexei V., et al. (författare)
  • Inhibition of TGF-beta modulates macrophages and vessel maturation in parallel to a lowering of interstitial fluid pressure in experimental carcinoma
  • 2005
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 0023-6837 .- 1530-0307. ; 85:4, s. 512-521
  • Tidskriftsartikel (refereegranskat)abstract
    • A pathologically elevated interstitial fluid pressure (IFP) is a characteristic of both clinical and experimental carcinoma. The soluble TGF-beta receptor type II-murine Fc:IgG2A chimeric protein (Fc:TbetaRII) lowers IFP in the KAT-4 experimental model for anaplastic thyroid carcinoma. Analyses of messenger RNA (mRNA) expressions by Affymetrix microarrays and RNase protection assays, as well as of protein expressions identified tumor macrophages as targets for Fc:TbetaRII. Treatment with Fc:TbetaRII reduced albumin extravasation, increased coverage of alpha-smooth muscle actin-positive cells and reduced expression of NG2, a marker of activated pericytes, in KAT-4 carcinoma blood vessels. Specific inhibition of interleukin-1 (IL-1), a major cytokine produced by activated macrophages, lowered carcinoma IFP to a similar degree as Fc:TbetaRII but had no significant effect on the parameters of blood vessel maturation. Neither Fc:TbetaRII nor inhibition of IL-1 changed blood vessel density. Finally, pretreatment of KAT-4 carcinomas with Fc:TbetaRII increased the antitumor efficacy of doxorubicin. Our data emphasize a potential role of tumor macrophages in carcinoma physiology and identify these cells as potential stromal targets for treatment aimed to improve efficacy of chemotherapy.
  •  
46.
  •  
47.
  • Smits, Anja, et al. (författare)
  • Coexpression of PDGF alpha and beta-receptors on medulloblastomas and other primitive neuroectodermal tumors (PNET) is consistent with an immature stem cell and neuronal derivation
  • 1996
  • Ingår i: Laboratory Investigation. - 0023-6837 .- 1530-0307. ; 74:1, s. 188-198
  • Tidskriftsartikel (refereegranskat)abstract
    • Medulloblastomas and related childhood primitive neuroectodermal tumors (PNET) are currently thought to originate from a multipotent stem cell that can give rise to a variety of different tumor types, representing different lines of differentiation and stages of maturation of the original stem cell. The proliferation and differentiation of different cell types in the central nervous system are influenced by growth factors, such as platelet-derived growth factor (PDGF). In this study, we investigated the expression of the two types of PDGF receptors, alpha and beta, on 14 cases of PNET by immunohistochemistry and in situ hybridization. To characterize the tumor cells according to their differentiation and maturation, we performed immunohistochemistry with Ab against several members of the intermediate filament family, such as neurofilament, glial fibrillary acidic protein, vimentin, and the embryonal marker nestin. For the cerebral PNET, we found that the phenotype of multidirectional differentiation (with coexpression of neurofilament, glial fibrillary acidic protein, vimentin, and in some cases nestin) was associated with the expression of both PDGF alpha and beta receptors on the tumor cells. Medulloblastomas (i.e., cerebellar PNET), however, often showed the phenotype of partially committed neuron-like precursor cells, and this was associated with the predominant expression of PDGF alpha receptors on the tumor cells. Our findings show that the PDGF alpha receptor, previously known to play a role in the normal development of cells of the glial lineage, either exclusively or in combination with the PDGF beta receptor, is expressed on tumor cells of neuronal derivation. This "aberrant" expression of PDGF alpha receptors on PNET may reflect a feature of the malignant phenotype of these tumors. Further studies are needed to study the biologic effects of PDGF-A and its receptor in PNET.
  •  
48.
  • Surace, Cecilia, et al. (författare)
  • A novel FISH assay for SS18-SSX fusion type in synovial sarcoma
  • 2004
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 1530-0307 .- 0023-6837. ; 84:9, s. 1185-1192
  • Tidskriftsartikel (refereegranskat)abstract
    • Synovial sarcoma is a morphologically, clinically and genetically distinct entity that accounts for 5-10% of all soft tissue sarcomas. The t(X;18)(p11.2;q11.2) is the cytogenetic hallmark of synovial sarcoma and is present in more than 90% of the cases. It produces three types of fusion gene formed in part by SS18 from chromosome 18 and by SSX1, SSX2 or, rarely, SSX4 from the X chromosome. The SS18-SSX fusions do not seem to occur in other tumor types, and it has been shown that in synovial sarcoma a clear correlation exists between the type of fusion gene and histologic subtype and, more importantly, clinical outcome. Previous analyses regarding the type of fusion genes have been based on PCR amplification of the fusion transcript, requiring access to good-quality RNA. In order to obtain an alternative tool to diagnose and follow this malignancy, we developed a fluorescence in situ hybridization (FISH) assay that could distinguish between the two most common fusion genes, that is, SS18-SSX1 and SS18-SSX2. The specificity of the selected bacterial artificial chromosome clones used in the detection of these fusion genes, as well as the sensitivity of the analysis in metaphase and interphase cells, was examined in a series of 28 synovial sarcoma samples with known fusion gene status. In all samples, the type of fusion was correctly identified by FISH. Thus, the assay described here should be useful for clarifying unresolved chromosome markers and for identifying fusion gene status in samples from which RNA of sufficient quality for PCR could not be extracted.
  •  
49.
  • Svec, David, et al. (författare)
  • Identification of inhibitors regulating cell proliferation and FUS-DDIT3 expression in myxoid liposarcoma using combined DNA, mRNA, and protein analyses.
  • 2018
  • Ingår i: Laboratory investigation; a journal of technical methods and pathology. - : Elsevier BV. - 1530-0307. ; 98, s. 957-967
  • Tidskriftsartikel (refereegranskat)abstract
    • FUS-DDIT3 belongs to the FET (FUS, EWSR1, and TAF15) family of fusion oncogenes, which collectively are considered to be key players in tumor development. Even though over 90% of all myxoid liposarcomas (MLS) have a FUS-DDIT3 gene fusion, there is limited understanding of the signaling pathways that regulate its expression. In order to study cell proliferation and FUS-DDIT3 regulation at mRNA and protein levels, we first developed a direct cell lysis approach that allows DNA, mRNA, and protein to be analyzed in the same sample using quantitative PCR, reverse transcription quantitative qPCR and proximity ligation assay, respectively. We screened 70 well-characterized kinase inhibitors and determined their effects on cell proliferation and expression of FUS-DDIT3 and FUS at both mRNA and protein levels in the MLS 402-91 cell line, where twelve selected inhibitors were evaluated further in two additional MLS cell lines. Both FUS-DDIT3 and FUS mRNA expression correlated with cell proliferation and both transcripts were co-regulated in most conditions, indicating that the common 5' FUS promotor is important in transcriptional regulation. In contrast, FUS-DDIT3 and FUS protein levels displayed more cell line dependent expression. Furthermore, most JAK inhibitors caused FUS-DDIT3 downregulation at both mRNA and protein levels. In conclusion, defining factors that regulate FUS-DDIT3 expression opens new means to understand MLS development at the molecular level.
  •  
50.
  • Svensson, Maria A., et al. (författare)
  • Testing mutual exclusivity of ETS rearranged prostate cancer
  • 2011
  • Ingår i: Laboratory Investigation. - : Elsevier BV. - 0023-6837 .- 1530-0307. ; 91:3, s. 404-412
  • Tidskriftsartikel (refereegranskat)abstract
    • Prostate cancer is a clinically heterogeneous and multifocal disease. More than 80% of patients with prostate cancer harbor multiple geographically discrete cancer foci at the time of diagnosis. Emerging data suggest that these foci are molecularly distinct consistent with the hypothesis that they arise as independent clones. One of the strongest arguments is the heterogeneity observed in the status of E26 transformation specific (ETS) rearrangements between discrete tumor foci. The clonal evolution of individual prostate cancer foci based on recent studies demonstrates intertumoral heterogeneity with intratumoral homogeneity. The issue of multifocality and interfocal heterogeneity is important and has not been fully elucidated due to lack of the systematic evaluation of ETS rearrangements in multiple tumor sites. The current study investigates the frequency of multiple gene rearrangements within the same focus and between different cancer foci. Fluorescence in situ hybridization (FISH) assays were designed to detect the four most common recurrent ETS gene rearrangements. In a cohort of 88 men with localized prostate cancer, we found ERG, ETV1, and ETV5 rearrangements in 51% (44/86), 6% (5/85), and 1% (1/86), respectively. None of the cases demonstrated ETV4 rearrangements. Mutual exclusiveness of ETS rearrangements was observed in the majority of cases; however, in six cases, we discovered multiple ETS or 50 fusion partner rearrangements within the same tumor focus. In conclusion, we provide further evidence for prostate cancer tumor heterogeneity with the identification of multiple concurrent gene rearrangements. Laboratory Investigation (2011) 91, 404-412; doi: 10.1038/labinvest.2010.179; published online 25 October 2010
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-50 av 167
Typ av publikation
tidskriftsartikel (88)
konferensbidrag (78)
forskningsöversikt (1)
Typ av innehåll
refereegranskat (87)
övrigt vetenskapligt/konstnärligt (80)
Författare/redaktör
Egevad, L (32)
Mertens, Fredrik (13)
Comperat, E (10)
Lopez-Beltran, A (8)
Algaba, F (8)
Camparo, P (8)
visa fler...
Montironi, R (8)
Varma, M (8)
Fall, K (8)
Andren, O (7)
Delahunt, B (7)
Kristiansen, G (7)
Samaratunga, H (6)
Rubin, MA (6)
Johansson, JE (5)
Wiklund, P (5)
Mucci, LA (5)
Carlson, J (5)
Berney, DM (5)
ANDERSSON, SO (5)
Elmberger, G (5)
Tsesmetzis, N (4)
Rassidakis, GZ (4)
Thyberg, J (4)
Nilsson, Jenny (4)
Magnusson, Linda (4)
Wiklund, F (4)
Leventaki, V (4)
Medeiros, LJ (4)
Sandstedt, B (4)
Martin, B. (3)
Nilsson, J. (3)
Thorlacius, Henrik (3)
Rahman, Milladur (3)
Griffiths, D (3)
Adami, HO (3)
Egevad, Lars (3)
Stattin, P (3)
Påhlman, Sven (3)
Funa, K (3)
Fiorentino, M (3)
Artursson, Per (3)
Kis, L (3)
Lindh, C (3)
Szuhai, K (3)
Söderholm, Johan D (3)
Amin, M (3)
Berney, D (3)
Gullberg, Elisabet (3)
PanaretakiS, T (3)
visa färre...
Lärosäte
Karolinska Institutet (110)
Lunds universitet (30)
Uppsala universitet (20)
Linköpings universitet (9)
Örebro universitet (5)
Göteborgs universitet (4)
visa fler...
Umeå universitet (2)
Kungliga Tekniska Högskolan (1)
Högskolan i Skövde (1)
visa färre...
Språk
Engelska (167)
Forskningsämne (UKÄ/SCB)
Medicin och hälsovetenskap (49)
Naturvetenskap (1)
Lantbruksvetenskap (1)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy