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Entire Experimental Period (entire + experimental_period)
Selected AbstractsLoss of Osteocyte Integrity in Association with Microdamage and Bone Remodeling After Fatigue In Vivo,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 1 2000Olivier Verborgt Abstract As a result of fatigue, bone sustains microdamage, which is then repaired by bone-remodeling processes. How osteoclastic activity is targeted at the removal of microdamaged regions of bone matrix is unknown. In the current studies, we tested the hypothesis that changes in osteocyte integrity, through the initiation of regulated cell death (apoptosis), are associated with fatigue-related microdamage and bone resorption. Ulnae of adult rats were fatigue-loaded to produce a known degree of matrix damage. Osteocyte integrity was then assessed histomorphometrically from terminal deoxynucleotidyl transferase,mediated deoxyuridine triphosphate,nick end labeling (TUNEL),stained sections to detect cells undergoing DNA fragmentation associated with apoptosis; toluidine blue,stained sections were used for secondary morphological confirmation. Ten days after loading, large numbers of TUNEL-positive osteocytes were found in bone surrounding microcracks and in bone surrounding intracortical resorption spaces (,300% increases over controls, p < 0.005). TUNEL labeling in loaded ulnae at sites distant from microcracks or resorption foci did not differ from that in control bone. Osteocytes in toluidine blue,stained sections showed equivalent trends to TUNEL-stained sections, with significant increases in pyknotic nuclei and empty lacunae associated with microcracks and intracortical resorption spaces. TUNEL-positive osteocytes were observed around bone microdamage by 1 day after loading (p < 0.01 relative to baseline), and their number remained elevated throughout the entire experimental period. Increases in empty lacunae and decreases in normal osteocyte numbers were observed over time as well. These studies show that (1) osteocyte apoptosis is induced by bone fatigue, (2) this apoptosis is localized to regions of bone that contain microcracks, and (3) osteoclastic resorption after fatigue also coincides with regions of osteocyte apoptosis. The strong associations between microdamage, osteocyte apoptosis, and subsequent bone remodeling support the hypothesis that osteocyte apoptosis provides a key part of the activation or signaling mechanisms by which osteoclasts target bone for removal after fatigue-induced matrix injury. [source] MULTIDISCIPLINARY PAIN ABSTRACTS: 47PAIN PRACTICE, Issue 1 2004Article first published online: 15 MAR 200 The purpose of this multicenter, randomized, controlled trial was to compare the effect of manual therapy to exercise therapy in sick-listed patients with chronic low back pain. The effects of exercise therapy and manual therapy on chronic low back pain with respect to pain, function, and sick leave have been investigated in a number of studies. The results are, however, conflicting. Patients with chronic low back pain or radicular pain sick-listed for more than 8 weeks and less than 6 months were included. A total of 49 patients were randomized to either manual therapy (n=27) or to exercise therapy (n=22). Sixteen treatments were given over the course of 2 months. Pain intensity, functional disability (Oswestry disability index), general health (Dartmouth Care Cooperative function charts), and return to work were recorded before, immediately after, at 4 weeks, 6 months, and 12 months after the treatment period. Spinal range of motion (Schober test) was measured before and immediately after the treatment period only. Although significant improvements were observed in both groups, the manual therapy group showed significantly larger improvements than the exercise therapy group on all outcome variables throughout the entire experimental period. Immediately after the 2-month treatment period, 67% in the manual therapy and 27% in the exercise therapy group had returned to work. It was concluded that improvements were found in both intervention groups, but manual therapy showed significantly greater improvement than exercise therapy in patients with chronic low back pain. The effects were reflected on all outcome measures, both on short- and long-term follow-up. [source] Productivity and energy partition of late lactation dairy cows during heat exposureANIMAL SCIENCE JOURNAL, Issue 1 2010Kyoung Hoon KIM ABSTRACT Three late-lactation Holstein cows were used to determine the effects of environmental temperature on performance and energy partitioning. Each cow was housed in a respiratory chamber for 30 consecutive days and exposed to three different conditions of environmental temperature: (i) 20°C and 20°C (20°C), (ii) 25°C and 20°C (25°C), (iii) 30°C and 25°C (30°C) during the day and night, respectively. The temperature was switched in an interval of 10 days. Humidity in the chamber was maintained at 55,65% through the entire experimental period. The daily mean as well as morning and evening rectal temperatures of Holstein cows increased linearly (P < 0.05) as chamber temperature increased. There was a significant linear reduction in dry matter (DM) intake (P < 0.05) and an increase in DM digestibility (P < 0.05). The response in milk yield, however, was not affected by heat stress. There were no significant differences among treatments for intake energy, heat production, net energy for lactation and net energy for gain. This results of this study disagreed with the assumption that late lactation cows gave priority to increasing body tissue at the expense of milk production under thermal stress. [source] Nutritional evaluation of waste date fruit as partial substitute for soybean meal in practical diets of juvenile Nile tilapia, Oreochromis niloticus L.AQUACULTURE NUTRITION, Issue 3 2009M.S. AZAZA Abstract The potential of waste date meal (WDM; low-quality date palm, Phoenix dactylifera L.) as a carbohydrate source in formulated diets for Nile tilapia was evaluated. Four isocaloric-practical diets (15.7 kJ g,1) were formulated incorporating WDM at 0, 100, 200 and 300 g kg,1 levels as partial substitutes for soybean meal (SBM). These were designated D0 [284 g crude protein (CP) and 383 g carbohydrate (CHO) kg,1 diet], D1 (279 g CP and 446 g CHO kg,1 diet), D2 (207 g CP and 495 g CHO kg,1 diet) and D3 (175 g CP and 578 g CHO kg,1 diet). Each diet was fed to three replicate groups of 30 fish [20.20 ± 0.09 g (±SE)] for 75 days. No feed-related mortality was observed during the entire experimental period. Final body weight (FBW) and specific growth rate (SGR) in the different treatments were statistically not significantly different (P > 0.05). Protein efficiency rate (PER) was lowest in diet D0 and increased with decrease of SBM content (D1,D3). A significant increase in whole body lipid content was recorded in fish fed diets D2 and D3. Results showed that WDM could be a substitute for SBM up to 300 g kg,1 in practical Nile tilapia diets without compromising growth. [source] Pheromone, juvenile hormone, and social status in the male lobster cockroach Nauphoeta cinereaARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 3 2008Rong Kou Abstract In this study, the major pheromone component, 3-hydroxy-2-butanone (3H-2B), released by dominants was measured during early scotophase. Both the JH III titer in the hemolymph and the 3H-2B content of the sternal glands of the dominants and subordinates were then measured during late scotophase and late photophase. These investigations were performed on encounter days 1, 2, 3, 5, 7, 9, 12, and 20. The results showed that, for non-aggressive posture (AP)-adopting socially naïve males (SNMs), both the 3H-2B release and the hemolymph JH III titer were maintained at a low level. Once a fight occurred, 3H-2B release was raised significantly in the AP-adopting dominants, but not in non-AP-adopting subordinates, and remained raised throughout the entire experimental period. At 30 min after the first encounter, the hemolymph JH III titer was significantly increased in dominants, but not in subordinates. A significantly higher hemolymph JH III titer was observed in dominants during late scotophase on days 3, 5, 12, and 20 and during late photophase on days 3, 5, and 20. After fighting, the sternal gland 3H-2B content of the dominants or subordinates was significantly lower than in SNMs. In dominants, the sternal gland 3H-2B content during late scotophase was significantly lower than that during late photophase in the first 9 domination days, while, in the subordinates, the 3H-2B content during late scotophase was either similar to, or significantly higher than, that in late photophase. In the dominants, 3H-2B release and JH III titer were positively correlated. In rank switchers, the switched social status was positively correlated with both 3H-2B release and JH III titer. Comparison of 3H-2B release and JH III titer in 1-time, 3-time, or 5-time dominants showed that, although winning significantly increased both 3H-2B release and JH III titer, there is no significant difference in 3H-2B release between 3- and 5-time winners, while the JH III titer was most significantly increased in the 3-time winners. The possible relationship between pheromone release, JH III titer, and social status is discussed. Arch. Insect Biochem. Physiol. 2008. © 2008 Wiley-Liss, Inc. [source] | ||||||||||