| 1. |
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| 2. |
- Laato, M, et al.
(författare)
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Epidermal growth factor (EGF) prevents methylprednisolone-induced inhibition of wound healing.
- 1989
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Ingår i: Journal of Surgical Research. - 0022-4804 .- 1095-8673. ; 47:4, s. 354-9
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Tidskriftsartikel (refereegranskat)abstract
- Subcutaneously implanted cylindrical hollow viscose cellulose sponges were used to study the effect of locally applied epidermal growth factor (EGF) on methylprednisolone-induced inhibition of granulation tissue formation in rats. In in vivo studies the sponges were treated immediately after implantation with a single injection of 2 mg (approximately 1.7 x 10(-3) M) of depot methylprednisolone or with its carrier solution only. Thereafter the implants were injected daily with 5 micrograms of EGF or with its carrier solution 0.1% albumin for 7 days. Methylprednisolone treatment decreased the accumulation of nucleic acids, collagen, and glycosaminoglycans in the developing granulation tissue. After daily injections of EGF the concentrations of these tissue components returned close to the control values. In cultures of rat granulation tissue fibroblasts, 10(-4) M and 10(-3)M methylprednisolone decreased collagen synthesis by 41 and 81% from the control level, respectively. In the presence of methylprednisolone EGF treatment could not increase collagen synthesis of fibroblasts. Methylprednisolone treatment resulted in a dose-dependent reduction in pro alpha 1(I) collagen mRNA levels, which was partially inhibited by low EGF concentrations (1 and 10 ng/ml). In the presence of methylprednisolone all concentrations of EGF increased fibronectin mRNA levels in a dose-dependent manner. It is concluded that EGF treatment can prevent the inhibitory effect of methylprednisolone on wound healing by stimulating fibroblast proliferation but does not stimulate collagen synthesis per cell.
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| 3. |
- Laato, M, et al.
(författare)
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Inflammatory reaction and blood flow in experimental wounds inoculated with Staphylococcus aureus.
- 1988
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Ingår i: European Surgical Research. - 0014-312X .- 1421-9921. ; 20:1, s. 33-8
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Tidskriftsartikel (refereegranskat)abstract
- Wound healing and granulation tissue formation can be accelerated by inoculation with live pathogenic microorganisms. For further elucidation of this phenomenon the present work was undertaken to study the effects of Staphylococcus aureus microorganisms on the inflammatory reaction and blood flow in developing granulation tissue in rats. Cylindrical hollow sponge implants were used as an inductive matrix for the growth of granulation tissue. In control animals 1 ml of wound fluid was withdrawn from the central dead space of the implant immediately after implantation and replaced with 1 ml of physiological saline. In experimental animals the implants were injected with live staphylococci, 10(2) or 10(5) microorganisms/ml. Wound fluid was analyzed 3, 7, 10 and 14 days after implantation, whereas measurements of local blood flow and albumin extravasation in the granulation tissue were made after 7 days. Implants inoculated with 10(5) organisms developed infection with pus formation while implants contaminated with 10(2) organisms showed no infection. In wound fluid specimens collected from the infected implants correlation between the number of polymorphonuclear leukocytes and prostaglandin E2 concentration was statistically significant. The most prominent finding in contaminated but uninfected implants was an enhanced local blood flow. This may explain some of the mechanisms leading to S. aureus-induced acceleration of wound healing.
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| 4. |
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| 5. |
- Laato, M, et al.
(författare)
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Stimulation of wound healing by epidermal growth factor. A dose-dependent effect.
- 1986
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Ingår i: Annals of Surgery. - 0003-4932 .- 1528-1140. ; 203:4, s. 379-81
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Tidskriftsartikel (refereegranskat)abstract
- This work was undertaken to study the effects of various doses of locally applied epidermal growth factor (EGF) on developing granulation tissue in rats. Cylindrical hollow sponge implants were used as an inductive matrix for the growth of granulation tissue. In the test groups, the implants were injected daily with a solution containing 0.2, 1, or 5 micrograms of EGF in 0.1% albumin while the implants of the control group were treated correspondingly with the carrier solution only. Analyses of granulation tissue in the sponge cylinders were carried out 7 days after implantation. A stimulatory, dose-dependent effect of EGF on granulation tissue formation was observed: cellularity increased, as evidenced by the elevated amounts of nucleic acids, and accumulation of collagen and glycosaminoglycans was enhanced.
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| 6. |
- Laato, Samuli, et al.
(författare)
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Did location-based games motivate players to socialize during COVID-19?
- 2020
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Ingår i: Telematics and informatics. - : Elsevier. - 0736-5853 .- 1879-324X. ; 54
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Tidskriftsartikel (refereegranskat)abstract
- Location-based games (LBGs) are typically played outdoors, as moving in the game is done by moving in the real world. However, during the COVID-19 pandemic, people were advised and even forced by governments to stay home and avoid social contact to slow down the spreading of the virus. The major LBG developers reacted by making in-game adjustments that allow playing from home, while still maintaining some incentives for players to go outdoors and socialise. For investigating factors influencing intention to play LBGs socially during the on-going pandemic, we collected cross-sectional survey data (N = 855) from Finnish players of the most popular LBG, Pokémon GO. The results showed that perceived severity of the pandemic and a positive attitude towards both governmental measures and in-game changes for combatting COVID-19 predicted intention to reduce social playing. Fear of missing out and deficient self-regulation increased playing intensity, which in turn negatively correlated with the intention to reduce social playing. Our findings demonstrate the influence that LBGs can have on human behaviour even during global crises such as COVID-19. As such, LBGs can be considered a resource in designing interventions for influencing movement at a population level.
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| 7. |
- Laato, Samuli, et al.
(författare)
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Location-Based Games and the COVID-19 Pandemic : An Analysis of Responses from Game Developers and Players
- 2020
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Ingår i: Multimodal Technologies and Interaction. - : MDPI. - 2414-4088. ; 4:2
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Tidskriftsartikel (refereegranskat)abstract
- In early 2020, as a countermeasure to mitigate the spread of the COVID-19 pandemic, governments issued limitations on the movements of their citizens, cancelling social events and advising people to stay home. As location-based games (LBGs) have been found to influence human movement, their role during COVID-19 deserves closer inspection. Under regular circumstances, the very aim of these games is to motivate people to go out, explore and meet other people. However, during COVID-19, people were advised to do the exact opposite. To study how LBG developers and players reacted to the situation, we used the netnography research method utilizing three types of data: (1) COVID-19 related in-game changes made by seven popular LBG developers during March 2020; (2) social media reactions on 20 posts across three popular Pokémon GO subreddits; and (3) the raiding activity (collaborative play) in Pokémon GO in a Finnish municipality during February–May 2020. All observed LBGs made in-game changes due to COVID-19. The social media reactions showed overwhelming appreciation towards these changes, and two central second order themes arose: (1) LBGs have the ability to influence human movement during pandemics; and (2) people should be able to self-regulate their behaviour during COVID-19 independent of LBG influence. Surprisingly, recorded Pokémon GO player activity in Finland was more influenced by offered in-game rewards than the COVID-19 pandemic. Our findings have implications on how games and gamification can be used to direct human movement in situations such as COVID-19 where population-level interventions are needed.
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| 8. |
- Laato, Samuli, et al.
(författare)
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Location-based Games as Exergames : From Pokémon To The Wizarding World
- 2020
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Ingår i: INTERNATIONAL JOURNAL OF SERIOUS GAMES. - : Serious Games Society. - 2384-8766. ; 7:1, s. 79-95
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Tidskriftsartikel (refereegranskat)abstract
- Exergames, i.e. games which aim to increase player’s physical activity, are a prominent sub-category of serious games (SGs). Recently, location-based games (LBGs) similar to Pokémon GO have gained the attention of exergame designers as they have been able to reach people who would otherwise not be motivated to exercise. Multiple studies have been conducted on Pokémon GO alone, identifying positive outcomes related to, for example, exercise and social well-being. However, with substantial findings derived from a single game, it is unclear whether the identified benefits of playing Pokémon GO are present in other similar games. In order to broaden the understanding of LBGs as exergames, this study investigates the gameplay features and initial reactions of early adopters to a game called Harry Potter: Wizards Unite (HPWU) which was launched in summer 2019. A questionnaire (N=346) was sent to HPWU players to measure the effects playing the game has on their physical activity. During the first week of play, an increase in mild physical activity was recorded among HPWU players, similar to what has been reported with Pokémon GO. Also almost half of respondents (46,82%) reported to play the game socially, showcasing how LBGs can generally have a positive impactalso on players’ social well-being.
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| 9. |
- Lepistö, J, et al.
(författare)
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Effects of homodimeric isoforms of platelet-derived growth factor (PDGF-AA and PDGF-BB) on wound healing in rat.
- 1992
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Ingår i: Journal of Surgical Research. - 0022-4804 .- 1095-8673. ; 53:6, s. 596-601
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Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor (PDGF) has been suggested to have a significant role in wound healing. The present work was aimed at studying the effects of PDGF-AA and PDGF-BB homodimers on developing granulation tissue in rats. Subcutaneously implanted hollow cylindrical cellulose sponges were used as an inductive matrix for the ingrowth of granulation tissue. Fifty microliters of solutions containing 0, 5, 50, or 500 ng of PDGF-AA or PDGF-BB homodimers was injected daily into the sponges; 7 days after implantation the granulation tissue in the sponge cylinders was analyzed. Five hundred nanograms of PDGF-BB stimulated significantly the accumulation of collagen, indicated by the elevated hydroxyproline content of the sponge (+34%, P < 0.001). Similarly, the amounts of RNA-ribose, nitrogen, hexosamines, and uronic acids were significantly higher, reflecting a PDGF-BB-induced increase in the accumulation of RNA, protein, and glycosaminoglycans. Analyses of wound fluid showed no essential changes in the composition of different cell types after PDGF-BB-treatment. The PDGF-AA-treatment increased significantly the mean amount of RNA but there were no significant changes in other parameters. In vitro both PDGF-AA and PDGF-BB increased significantly the number of rat granulation tissue derived fibroblasts in culture at concentrations of 10 and 30 ng/ml. This proliferative effect resulted in a lowered level of protein synthesis per cell. To conclude, PDGF-BB accelerates granulation tissue formation both in vitro and in vivo, whereas PDGF-AA is effective in vitro but it is clearly less effective in vivo.
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| 10. |
- Lepistö, J, et al.
(författare)
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Stimulation of wound healing by the immunomodulator LS-2616 (Linomide).
- 1994
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Ingår i: World Journal of Surgery. - 0364-2313 .- 1432-2323. ; 18:6, s. 818-20; discussion 821
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Tidskriftsartikel (refereegranskat)abstract
- LS-2616 (Linomide), a quinoline-3-carboxamide, is an immunomodulator that has been suggested to act on macrophage-like cells. Based on a hypothesis that LS-2616 would stimulate macrophages in the wound and affect the healing process, the effects of LS-2616 on developing granulation tissue were evaluated using a wound model in rats. Subcutaneously implanted cylindrical cellulose sponges were used as an inductive matrix for the ingrowth of granulation tissue. LS-2616 was continuously present at a concentration of 1.2 mg/ml in the drinking water either for 7 days before implantation or starting at the implantation of sponges. Seven days after implantation LS-2616 treatment increased the mean amounts of nitrogen and collagen hydroxyproline over the control level [+20% (p < 0.05) and +59% (p < 0.05), respectively]. The effect was less pronounced in the rats receiving LS-2616 in advance [+7% (NS) and +38% (p < 0.05), respectively]. The mean amounts of nucleic acids and proteoglycans tended to decrease in the rats receiving LS-2616 in advance compared to the control rats [-12% to 13% (NS) and -25% (p < 0.05), respectively]. It was concluded that continuous oral administration of LS-2616 enhanced wound repair in the rat. This immunoenhancement of wound healing results in increased accumulation of collagen.
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