SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "swepub ;lar1:(umu);pers:(Lammi Mikko 1961)"

Sökning: swepub > Umeå universitet > Lammi Mikko 1961

  • Resultat 1-10 av 225
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Qu, Chengjuan, 1967-, et al. (författare)
  • Chondrogenic differentiation of human pluripotent stem cells in chondrocyte co-culture
  • 2013
  • Ingår i: International Journal of Biochemistry and Cell Biology. - : Elsevier. - 1357-2725 .- 1878-5875. ; 45:8, s. 1802-1812
  • Tidskriftsartikel (refereegranskat)abstract
    • Chondrogenic differentiation of human embryonic (hESCs) or induced pluripotent stem cells (hiPSCs) has been achieved in embryoid bodies (EBs) by adding selected growth factors to the medium. Also chondrocyte-secreted factors have been considered to promote the chondrogenic differentiation. Hence, we studied whether co-culture with primary chondrocytes can induce hESCs or hiPSCs to differentiate into chondrocyte lineage. Co-culture of hESCs or hiPSCs was established in a transwell insert system in feeder-free culture conditions, while hESCs or hiPSCs grown alone in the wells were used as controls. After 3-week co-culture with weekly replenished chondrocytes, the chondrogenically committed cells (hCCCs) were evaluated by morphology, immunocytochemistry, quantitative real-time RT-PCR, and analysis of chondrogenic, osteogenic and adipogenic differentiation markers. The expressions of chondrocyte- and pluripotency-associated genes were frequently measured during the monolayer expansion of hCCCs from passage 1 to 10. Human CCCs displayed morphology similar to chondrocytes, and expressed chondrocyte-associated genes, which were declined following passaging, similarly to passaged chondrocytes. They also formed a chondrogenic cell pellet, and differentiated into chondrocytic cells, which secreted abundant extracellular matrix. Human CCCs also proliferated rapidly. However, they did not show osteogenic or adipogenic differentiation capacity. Our results show that co-culture of hESCs or hiPSCs with primary chondrocytes could induce specific chondrogenic differentiation.
  •  
2.
  • Pulliainen, Outi, et al. (författare)
  • Poly-L-D-lactic acid scaffold in the repair of porcine knee cartilage lesions.
  • 2007
  • Ingår i: Tissue engineering. - : Mary Ann Liebert Inc. - 1076-3279 .- 1557-8690. ; 13:6, s. 1347-55
  • Tidskriftsartikel (refereegranskat)abstract
    • Articular cartilage injuries cause a major clinical problem because of the negligible repair capacity of cartilage. Autologous chondrocyte transplantation is a surgical method developed to repair cartilage lesions. In the operation, cartilage defect is covered with a periosteal patch and the suspension of cultured autologous chondrocytes is injected into the lesion site. The method can form good repair tissue, but new techniques are needed to make the operation easier and to increase the postoperative biomechanical properties of the repair tissue. In this study, we investigated poly-L,D-lactic acid (PLDLA) scaffolds alone or seeded with autologous chondrocytes in the repair of circular 6-mm cartilage lesions in immature porcine knee joints. Spontaneous repair was used as a reference. Histologic evaluation of the repair tissue showed that spontaneous repair exhibited higher scores than either PLDLA scaffold group (with or without seeded chondrocytes). The scaffold material was most often seen embedded in the subchondral bone underneath the defect area, probably because of the hardness of the PLDLA material. However, some of the cell-seeded and nonseeded scaffolds contained cartilaginous tissue, suggesting that invasion of mesenchymal cells inside nonseeded scaffolds had occurred. Hyaluronan deposited in the scaffold had possibly acted as a chemoattractant for the cell recruitment. In conclusion, the PLDLA scaffold material used in this study was obviously mechanically too hard to be used for cartilage repair in immature animals.
  •  
3.
  • Vasara, Anna I, et al. (författare)
  • Immature porcine knee cartilage lesions show good healing with or without autologous chondrocyte transplantation.
  • 2006
  • Ingår i: Osteoarthritis and cartilage / OARS, Osteoarthritis Research Society. - : Elsevier BV. - 1063-4584 .- 1522-9653. ; 14:10, s. 1066-74
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVE: The purpose of this study was to find out how deep chondral lesions heal in growing animals spontaneously and after autologous chondrocyte transplantation. METHODS: A 6mm deep chondral lesion was created in the knee joints of 57 immature pigs and repaired with autologous chondrocyte transplantation covered with periosteum or muscle fascia, with periosteum only, or left untreated. After 3 and 12 months, the repair tissue was evaluated with International Cartilage Repair Society (ICRS) macroscopic grading, modified O'Driscoll histological scoring, and staining for collagen type II and hyaluronan, and with toluidine blue and safranin-O staining for glycosaminoglycans. The repair tissue structure was also examined with quantitative polarized light microscopy and indentation analysis of the cartilage stiffness. RESULTS: The ICRS grading indicated nearly normal repair tissue in 65% (10/17) after the autologous chondrocyte transplantation and 86% (7/8) after no repair at 3 months. At 1 year, the repair tissue was nearly normal in all cases in the spontaneous repair group and in 38% (3/8) in the chondrocyte transplantation group. In most cases, the cartilage repair tissue stained intensely for glycosaminoglycans and collagen type II indicating repair tissue with true constituents of articular cartilage. There was a statistical difference in the total histological scores at 3 months (P=0.028) with the best repair in the spontaneous repair group. A marked subchondral bone reaction, staining with toluidine blue and collagen type II, was seen in 65% of all animals. CONCLUSIONS: The spontaneous repair ability of full thickness cartilage defects of immature pigs is significant and periosteum or autologous chondrocytes do not bring any additional benefits to the repair.
  •  
4.
  • Vasara, Anna I, et al. (författare)
  • Subchondral bone reaction associated with chondral defect and attempted cartilage repair in goats.
  • 2004
  • Ingår i: Calcified tissue international. - : Springer Science and Business Media LLC. - 0171-967X .- 1432-0827. ; 74:1, s. 107-14
  • Tidskriftsartikel (refereegranskat)abstract
    • Repair of cartilage damage with autologous chondrocyte transplantation (ACT) has become popular in clinical use during the past few years. Although clinical results have mostly been successful, several unanswered questions remain regarding the biological mechanism of the repair process. The aim of this study was to develop a goat model for ACT. The repair was not successful due to the graft delamination, but we characterize the subchondral changes seen after the procedure. A chondral lesion was created in 14 goat knees, operated on 1 month later with ACT, and covered with periosteum or a bioabsorbable poly-L/D-lactide scaffold. After 3 months, only two of the five lesions repaired with ACT showed partly hyaline-like repair tissue, and all lesions (n = 4) with the scaffold failed. Even though the lesions did not extend through the calcified cartilage, the bone volume and collagen organization of bone structure were decreased when assessed by quantitative polarized light microscopy. There was a significant loss of bone matrix and distortion of the trabecular structure of subchondral bone, which extended several millimeters into the bone. The subchondral bone demonstrated strong hyaluronan staining in the bone marrow and cartilaginous areas with signs of endochondral ossification, suggesting structural remodeling of the bone. The goat model used here proved not to be an optimal model for ACT. The changes in subchondral bone may alter the biomechanical properties of the subchondral plate and thus the long-term survival of the repair tissue after ACT.
  •  
5.
  • Anerillas, Luis Oliveros, et al. (författare)
  • Three-dimensional osteogenic differentiation of bone marrow mesenchymal stem cells promotes matrix metallopeptidase 13 (Mmp13) expression in type i collagen hydrogels
  • 2021
  • Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 22:24
  • Tidskriftsartikel (refereegranskat)abstract
    • Autologous bone transplantation is the principal method for reconstruction of large bone defects. This technique has limitations, such as donor site availability, amount of bone needed and morbidity. An alternative to this technique is tissue engineering with bone marrow-derived mesenchymal stem cells (BMSCs). In this study, our aim was to elucidate the benefits of culturing BMSCs in 3D compared with the traditional 2D culture. In an initial screening, we combined BMSCs with four different biogels: unmodified type I collagen (Col I), type I collagen methacrylate (ColMa), an alginate and cellulose-based bioink (CELLINK) and a gelatin-based bioink containing xanthan gum (GelXA-bone). Col I was the best for structural integrity and maintenance of cell morphology. Osteogenic, adipogenic, and chondrogenic differentiations of the BMSCs in 2D versus 3D type I collagen gels were investigated. While the traditional pellet culture for chondrogenesis was superior to our tested 3D culture, Col I hydrogels (i.e., 3D) favored adipogenic and osteogenic differentiation. Further focus of this study on osteogenesis were conducted by comparing 2D and 3D differentiated BMSCs with Osteoimage® (stains hydroxyapatite), von Kossa (stains anionic portion of phosphates, carbonates, and other salts) and Alizarin Red (stains Ca2+ deposits). Multivariate gene analysis with various covariates showed low variability among donors, successful osteogenic differentiation, and the identification of one gene (matrix metallopeptidase 13, MMP13) significantly differentially expressed in 2D vs. 3D cultures. MMP13 protein expression was confirmed with immunohistochemistry. In conclusion, this study shows evidence for the suitability of type I collagen gels for 3D osteogenic differentiation of BMSCs, which might improve the production of tissue-engineered constructs for treatment of bone defects.
  •  
6.
  • Arasu, Uma Thanigai, et al. (författare)
  • Human mesenchymal stem cells secrete hyaluronan-coated extracellular vesicles
  • 2017
  • Ingår i: Matrix Biology. - Amsterdam : Elsevier. - 0945-053X .- 1569-1802. ; 64, s. 54-68
  • Tidskriftsartikel (refereegranskat)abstract
    • Extracellular vesicles (EVs) secreted by stem cells are potential factors mediating tissue regeneration. They travel from bone marrow stem cells into damaged tissues, suggesting that they can repair tissue injuries without directly replacing parenchymal cells. We have discovered that hyaluronan (HA) synthesis is associated with the shedding of HA-coated EVs. The aim of this study was to test whether bone marrow-derived hMSCs secrete HA-coated EVs. The EVs secreted by MSCs were isolated by differential centrifugation and characterized by nanoparticle tracking analysis. Their morphology and budding mechanisms were inspected by confocal microscopy and correlative light and electron microscopy. Hyaluronan synthesis of hMSCs was induced by lipopolysaccharide and inhibited by RNA interference and 4-methylumbelliferone. It was found that the MSCs have extremely long apical and lateral HA-coated filopodia, typical for cells with an active HA secretion. Additionally, they secreted HA-coated EVs carrying mRNAs for CD44 and all HAS isoforms. The results show that stem cells have a strong intrinsic potential for HA synthesis and EV secretion, and the amount of HA carried on EVs reflects the HA content of the original cells. These results show that the secretion of HA-coated EVs by hMSCs is a general process, that may contribute to many of the mechanisms of HA-mediated tissue regeneration. Additionally, an HA coat on EVs may regulate their interactions with target cells and participate in extracellular matrix remodeling.
  •  
7.
  • Arokoski, Jari, et al. (författare)
  • Nivelrikon etiopatogeneesi [Etiopathogenesis of osteoarthritis].
  • 2001
  • Ingår i: Duodecim. - : Duodecim. - 0012-7183 .- 2242-3281. ; 117:16, s. 1617-1626
  • Tidskriftsartikel (refereegranskat)abstract
    • Nivelrikon patofysiologia tunnetaan huonosti. Nykykäsityksen mukaan artroosissa ei olekyse nivelruston passiivisesta kulumisesta vaan biokemiallisesta tapahtumasarjasta, jossasoluväliaineen tuhoutuminen saa ylivallan rustoa korjaavista prosesseista. Nivelrikon alkuvaiheessarustosoluissa eli kondrosyyteissä aktivoituvat sekä ruston aineosien synteesitoimintaettä rustoa hajottavien entsyymien ilmentyminen ja niitä koodaavien geenientoiminta. Nivelrikko on koko nivelen sairaus, joka aiheuttaa muutoksia niin nivelrustossa,luussa kuin pehmytosissakin. Vallitsevan käsityksen mukaan nivelrikko käynnistyynivelruston pinnallisesta vyöhykkeestä. On myös esitetty, että nivelalueen altistuminenliialliselle kuormitukselle aiheuttaisi ensin rustonalaisen luun paksunemisen ja jäykkenemisen,mikä puolestaan altistaisi nivelruston suuremmille kuormittaville voimille. Riskitekijöistätärkeimpiä ovat ikääntyminen, liikapaino, niveleen kohdistuvat vammat ja ruumiillisentyön aiheuttama liikarasitus. Perinnöllisten tekijöiden osuus on myös merkittävä.Ruston kollageenien rakennevirheiden tiedetään altistavan nivelrikolle.
  •  
8.
  • Arokoski, Jari, et al. (författare)
  • Nivelrikon lääkehoito [Medical treatment of osteoarthritis]
  • 2008
  • Ingår i: Duodecim. - 0012-7183. ; 124, s. 1899--1907
  • Forskningsöversikt (refereegranskat)abstract
    • teho ei riitä, siirrytään tulehduskipulääkkeisiin niiden haitat huomioiden. Ellei parasetamolilla ja tulehduskipulääkkeillä saada riittävää tehoa nivelrikkokipuun tai niitä ei haittavaikutusten vuoksi ole mahdollista käyttää, kipua voidaan hoitaa opioideilla. Niveleen annettu glukokortikoidi- tai hyaluronaattihoito näyttää lievittävän nivelkipua. Glukosamiini saattaa helpottaa nivelrikon oireita, mutta luotettava tieteellinen näyttö sen tehosta puuttuu edelleen. Kehitteillä on nykyisiin vaikutusmekanismeihin tukeutuvia oireita lievittäviä lääkeaineita, mutta merkittävämpi ja haastavampi pitkän aikavälin tavoite on kehittää rustovaurioita hidastavia lääkkeitä. Potentiaalisia tautiprosessiin vaikuttavia lääkeaineita ovat mm. rustomatriksia hajottavien entsyymien estäjät, typpioksidisynteesin estäjät, sytokiinimodulaattorit ja PPAR-agonistit.
  •  
9.
  • Beier, Frank, et al. (författare)
  • Localization of silencer and enhancer elements in the human type X collagen gene.
  • 1997
  • Ingår i: Journal of Cellular Biochemistry. - : John Wiley & Sons. - 0730-2312 .- 1097-4644. ; 66:2, s. 210-218
  • Tidskriftsartikel (refereegranskat)abstract
    • Collagen type X is a short, network-forming collagen expressed temporally and spatially tightly controlled in hypertrophic chondrocytes during endochondral ossification. Studies on chicken chondrocytes indicate that the regulation of type X collagen gene expression is regulated at the transcriptional level. In this study, we have analyzed the regulatory elements of the human type X collagen (Col10a1) by reporter gene constructs and transient transfections in chondrogenic and nonchondrogenic cells. Four different promoter fragments covering up to 2,864 bp of 5'-flanking sequences, either including or lacking the first intron, were linked to luciferase reporter gene and transfected into 3T3 fibroblasts, HT1080 fibrosarcoma cells, prehypertrophic chondrocytes from the resting zone, hypertrophic chondrocytes, and chondrogenic cell lines. The results indicated the presence of three regulatory elements in the human Col10a1 gene besides the proximal promoter. First, a negative regulatory element located between 2.4 and 2.8 kb upstream of the transcription initiation site was active in all nonchondrogenic cells and in prehypertrophic chondrocytes. Second, a positive, but also non-tissue-specific positive regulatory element was present in the first intron. Third, a cell-type-specific enhancer element active only in hypertrophic chondrocytes was located between -2.4 and -0.9 kb confirming a previous report by Thomas et al. [(1995): Gene 160:291-296]. The enhancing effect, however, was observed only when calcium phosphate was either used for transfection or included in the culture medium after lipofection. These findings demonstrate that the rigid control of human Col10a1 gene expression is achieved by both positive and negative regulatory elements in the gene and provide the basis for the identification of factors binding to those elements.
  •  
10.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-10 av 225
Typ av publikation
tidskriftsartikel (194)
forskningsöversikt (16)
bokkapitel (6)
konferensbidrag (4)
annan publikation (3)
doktorsavhandling (2)
visa fler...
visa färre...
Typ av innehåll
refereegranskat (217)
övrigt vetenskapligt/konstnärligt (8)
Författare/redaktör
Helminen, Heikki (56)
Guo, Xiong (54)
Tammi, Markku (43)
Jurvelin, Jukka (31)
Qu, Chengjuan, 1967- (26)
visa fler...
Kiviranta, Ilkka (26)
Parkkinen, Jyrki (22)
Kaarniranta, Kai (21)
Töyräs, Juha (21)
Hyttinen, Mika (18)
Sironen, Reijo (18)
Karjalainen, Hannu (17)
Tiitu, Virpi (16)
Elo, Mika (15)
Wang, Xi (13)
Ning, Yujie (13)
Lappalainen, Reijo (13)
Zhang, Feng (12)
Arokoski, Jari (12)
Liu, Huan (12)
Saarakkala, Simo (12)
Wu, Cuiyan (12)
Inkinen, Ritva (12)
Wang, Sen (11)
Tammi, Raija (11)
Jortikka, Matti (9)
Pulkkinen, Hertta (9)
Rilla, Kirsi (8)
Yang, Lei (8)
Lammi, Pirkko (8)
Korhonen, Rami (8)
Puustjärvi, Kaija (8)
Han, Jing (7)
von der Mark, Klaus (7)
Zhang, Yanan (7)
Qu, Cheng-Juan, 1967 ... (7)
Kröger, Heikki (6)
Säämänen, Anna-Marja (6)
Yu, Fangfang (6)
Ylärinne, Janne, 199 ... (6)
Zhang, Pan (5)
Häkkinen, Tomi (5)
Laasanen, Mikko (5)
Tan, Wuhong (5)
Lapveteläinen, Tuomo (5)
Rieppo, Jarno (5)
Sistonen, Lea (5)
Rieppo, Lassi (5)
Prittinen, Juha, 198 ... (5)
visa färre...
Lärosäte
Göteborgs universitet (3)
Karolinska Institutet (1)
Språk
Engelska (216)
Finska (8)
Kinesiska (1)
Forskningsämne (UKÄ/SCB)
Medicin och hälsovetenskap (213)
Naturvetenskap (128)
Teknik (13)

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