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- Aspenberg, Per, et al.
(författare)
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The bone morphogenetic proteins antagonist noggin inhibits membranous ossification
- 2001
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 1523-4681 .- 0884-0431. ; 16:3, s. 497-500
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Tidskriftsartikel (refereegranskat)abstract
- Bone morphogenetic proteins (BMPs) are expressed and secreted during fracture repair. Although they are likely to be required for this process, little is known about their physiological role in bone regeneration. Noggin is a protein that specifically binds and inactivates several BMPs, It plays fundamental roles during early embryonal development and limb morphogenesis by this BMP-inactivating activity. This study shows that Noggin can modify bone formation in vivo in the adult animal and, thus, indirectly, that BMP signaling is indispensable in this process. A noggin mutein (hNg Delta B2-Fc) engineered so as to display increased bioavailability was used. Bilateral titanium bone chambers mere inserted in 70 rats, and side comparisons for bone formation in the chambers were done. The hNg Delta B2-Fc had no effect on total amount of tissue formed in the chamber but decreased the amount of bone compared with both buffer controls and a control made up of an Fc-tagged IL-6R alpha protein, which had no effects of its own, Also, wild-type noggin inhibited bone formation. Thus, endogenous BMP signaling is necessary for normal bone regeneration.
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- Botermans, Jos, et al.
(författare)
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Comparison between air inlet via channels under the building and air inlets via the ceiling for growing-finishing pigs
- 2014
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the studies was to compare the indoor climate between two different ventilation systems for growing-finishing pigs. In one housing system the air came into the pig house via channels under the lying area of the pigs. The air came into the compartment close to the lying area of the pigs. The first part of the exhaust air was via another channel along the manure channel (pit ventilation). The rest of the exhaust air was via two fans in the ceiling (farm 1). In the other housing system the air came into the pig house via air inlets in the ceiling. The exhaust air was via two fans in the ceiling (farm 2). Measurements were done during one summer batch and one winter batch. Air temperature was measured for 5-8 weeks with mini-loggers. Ammonia concentration, carbon dioxide concentration, air speed and differences in air pressure between in and outside the pig house, were registered at 4 occasions. During summer time, the temperature of incoming air via the channels under the building (farm 1) was almost the same as the temperature of the air outside. So the cooling effect in the channels was very small. However, on the farm with air inlets in the ceiling (farm 2), the incoming air, during the afternoon, was about 3 0C above the temperature outside. So during the warmest period of the day, the air was heated on the ceiling. On the farm with channels under the lying area, the pigs continued to lie on the concrete lying area instead of the slatted flooring and the cleanliness of the pens was good (farm 1). During winter time, the temperature of the incoming air via the channels under the building was about 4 0C above the air temperature outside. On the farm with air inlets in the ceiling, the air temperature of the incoming air was the same as the temperature of the air outside.
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- Gan, Li-Ming, 1969, et al.
(författare)
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Incremental Value of Transthoracic Doppler Echocardiography-Assessed Coronary Flow Reserve in Patients With Suspected Myocardial Ischemia Undergoing Myocardial Perfusion Scintigraphy.
- 2017
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Ingår i: Journal of the American Heart Association. - 2047-9980. ; 6:4
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Tidskriftsartikel (refereegranskat)abstract
- Adenosine-assisted transthoracic Doppler-derived coronary flow reserve (TDE-CFR) reflects coronary vascular function. The prognostic and incremental value of left anterior descending coronary artery TDE-CFR above myocardial perfusion scintigraphy in patients with suspected myocardial ischemia has not yet been studied.Three hundred seventy-one patients (mean age, 62.3±8.7years; 46.8% males) referred to myocardial perfusion scintigraphy attributed to suspected myocardial ischemia were included in the study. The TDE-CFR result was blinded to the referring physician. Patients were followed up regarding major cardiovascular events, defined as cardiovascular death, myocardial infarction, or acute revascularization during a median follow-up time of 4.5years. A TDE-CFR value of ≤2.0 was considered reduced. Major cardiovascular events occurred during follow-up in 60 patients (16.2%). A reduced TDE-CFR was detected in 76 patients (20.5%). Patients with reduced TDE-CFR had an event rate of 36.8% compared to 10.8% in patients with normal TDE-CFR (unadjusted hazard ratio, 4.63; 95% CI, 2.78-7.69; P<0.001). In a multivariate model, TDE-CFR remained a significant independent predictor of major cardiovascular events. The major cardiovascular events rate was 7.5% in patients without myocardial perfusion scintigraphy-detected myocardial ischemia and normal TDE-CFR (n=200), 24.2% in patients without ischemia but with reduced TDE-CFR (n=33), and 46.5% in patients with both myocardial perfusion scintigraphy-detected myocardial ischemia and a reduced TDE-CFR (n=43; P<0.001).Coronary microvascular dysfunction, as determined by TDE-CFR, is a strong independent predictor of cardiovascular events and adds incremental prognostic value compared with myocardial perfusion scintigraphy. The current study supports routine assessment of CFR in patients with suspected ischemic heart disease.
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- Jeppsson, Charlotte, et al.
(författare)
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A combination of bisphosphonate and BMP additives in impacted bone allografts
- 2003
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Ingår i: Acta Orthopaedica Scandinavica. - : Medical Journals Sweden AB. - 0001-6470. ; 74:4, s. 483-489
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Tidskriftsartikel (refereegranskat)abstract
- OP-1 increases bone ingrowth distance of new bone into allografts (TΣgil et al. 2000), but the bone density after incorporation may be reduced by an increase in resorption (H÷stner et al. 2000). Bisphosphonates inactivate osteoclasts and can be used to increase allograft bone density after incorporation (Aspenberg and ┼strand 2002). A combination of locally-applied bisphosphonate and OP-1 in the graft could therefore be expected to increase both new bone ingrowth and density. We tested this by using a rat bone chamber model. OP-1 alone increased the ingrowth distance of bone. Clodronate increased final bone density greatly, but reduced the ingrowth distance of new bone into grafts that were extremely impacted. This reduction was improved by adding OP-1. Regardless of graft density, combinations of OP-1 and clodronate included a high final bone density, but the ingrowth distances were shorter than with OP-1 alone. These data indicate that new bone and tissue ingrowth into a compacted graft depends on resorption and that resorption is a prerequisite for the stimulating effect of OP-1 in this experimental set-up. Although the problems associated with the use of OP-1 in impaction grafting may be solved by adding a bisphosphonate, some of the benefits of OP-1 can be lost.
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- Jeppsson, Charlotte
(författare)
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BMP implants in bone formation. Studies in rabbits and rats
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Bone morphogenic proteins, BMPs, are a group endogenous proteins that are highly conserved through evolution. The amino acid sequences of about 15 different BMPs are now known and recombinant human BMPs are commercially available. Implantation of an individual BMP protein is sufficient to induce bone formation even at a subcutaneous site. Our initial studies discovered inhibition of bone formation by BMP-2 implanted in a titanium chamber model in rabbit tibia. This paradoxical effect was previously unknown, and lead to studies trying to elucidate the required conditions for BMPs to induce bone formation. Inhibition of bone formation was still found, despite testing different doses of BMP-2, another BMP (OP-1), a different carrier, and altered microenvironment. Stimulation of bone formation by BMP-2 was finally shown in a similar titanium chamber model by adding micromotion. The used titanium model induces minimal fracture surfaces when implanting the BMP and thus a minimal trauma unless micromotion was added. Therefore, we conclude that a certain amount of trauma probably is a prerequisite for BMP induction of bone formation. Impaction of morselized allografts in rat titanium chamber models slowed down new bone ingrowth. This delay was overcome by adding OP-1 to the impacted graft. A marrow-like cavity forms by resorption behind the bone ingrowth frontier in impacted bone allografts. In situations where the graft must resist deformation during remodeling, this resorption might compromise the final result. Bisphosphonates bind to the mineral phase of bone and induce cell death to osteoclasts resorbing the bone. By treating impacted allografts in rats with a bisphosphonate we increased the bone density (both new bone and remaining graft) after 6 weeks. When treating allograft with both a bishosphonate and a BMP (OP-1) the previous increase in new bone ingrowth by OP-1 was lost, suggesting that, at least in some grafting situations, resorption may be a prerequisite for stimulation of bone ingrowth by a BMP.
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- Jeppsson, Knut-Håkan, et al.
(författare)
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Cooling growing/finishing pigs with showers in the slatted area: Effect on animal occupation area, pen fouling and ammonia emission
- 2021
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Ingår i: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 243
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Tidskriftsartikel (refereegranskat)abstract
- Growing and finishing pigs kept in insulated buildings are often exposed to high ambient temperature during summer. In high-temperature conditions, pigs in partly slatted pens change their behaviour to increase lying on the slatted area and fouling on the solid Hoor area, resulting in increased ammonia emissions. One way to cool the animals is to shower/sprinkle water in the slatted area, allowing pigs to wet their skin to increase heat loss. This study examined the effects of providing showers on pig activity and occupation area in pens, pen fouling and ammonia emission from the room. The investigation was performed in a commercial growing-finishing house with 10 identical rooms, each containing 16 pens for 9-13 pigs growing from 25-30 kg to 115-120 kg. Pigs were introduced into two parallel rooms in the house. During two summers and four batches, one room with showers in the slatted area and one room without per batch were compared in terms of concentrations of carbon dioxide (CO2) and ammonia (NH3), pig activity and occupation area in the pen, pen fouling and NH3 emissions, recorded on four measuring occasions (M1-M4) during the growing period. Gas concentrations were measured using a photoacoustic analyser, pig activity and occupation area detected by machine vision techniques and pen fouling was visually investigated. Climate parameters (air temperature and relative humidity) were logged continuously during the entire growing period. Ammonia emission was calculated from ventilation rate (determined by the indirect CO2 tracer gas method) and the difference in ammonia concentration between outlet and inlet air.The results showed that the pigs spent less time lying on the slats (p < 0.05) and the solid Hoor was cleaner (p < 0.05) on measuring occasions M2, M3 and M4 in rooms with showers than in control rooms. Mean NH3 emission for the four measurement occasions were 3.0-5.1 g pig(-1) day(-1) and 4.2-10.0 g pig(-1) day(-1) for the shower and control rooms, respectively. The differences were significant (p < 0.05) for all measuring occasions. The results also show improved animal environment when using showers to cool pigs at high ambient temperatures.Overall, providing showers in the slatted area in partly slatted pens encouraged growing/finishing pigs to lie in the lying area, reduced problems with pen fouling and decreased NH3 emissions by 45%. The latter could be partly due to reduced pen fouling and partly to dilution of urine on the slatted area and on the surface of slurry in the pit.
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