| 1. |
- Knutsson, Anders, et al.
(författare)
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Postprandial responses of glucose, insulin and triglycerides : Influence of the timing of meal intake during night work
- 2002
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Ingår i: Nutrition and Health. - : SAGE Publications. - 0260-1060 .- 2047-945X. ; 16, s. 133-141
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Tidskriftsartikel (refereegranskat)abstract
- The objective was to study the postprandial responses of glucose, insulin and triglycerides to meal intake at different clock times during night work. Eleven night shift working nurses participated. Identical test meals were ingested at 19:30, 23:30 and 03:30, and contained 440 kcal/ 1860 kJ of energy (33 E% fat, 51 E% carbohydrate, 16 E% protein). The food intake was standardized three days before the first test meal. Blood samples were drawn just before the test meals were ingested and thereafter at 30, 60, 90, 120, 180 and 240 minutes. The postprandial responses were estimated as the total area under the curve (AUC) and significance testing was done using repeated measures ANOVA. The highest insulin level was found after meal intake at 23:30, and the lowest after meal intake 03:30. The glucose response showed the same pattern. The insulin response to food intake in night working nurses is more pronounced in the night compared with morning and evening. The results would have implications for metabolic and cardiovascular disorders in night workers.
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| 2. |
- Björklund, Martin, et al.
(författare)
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Muscle stretch-induced modulation of noxiously activated dorsal horn neurons of feline spinal cord.
- 2004
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Ingår i: Neuroscience research. - : Elsevier BV. - 0168-0102 .- 1872-8111. ; 48:2, s. 175-184
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Tidskriftsartikel (refereegranskat)abstract
- The present work was designed to check for the possibility of interactions between mechanical innocuous and chemically induced noxious muscle afferent inputs on discharge behavior of nociceptive superficial dorsal horn neurons (SDHNs) of the spinal cord in decerebrated cats. The innocuous and noxious stimuli were applied separately and in combination, so that the effects of the innocuous stimulus on nociceptive processing could be evaluated. The innocuous stimulus consisted of ramp-and-hold stretches of the gastrocnemius muscles, whereas the noxious stimulus consisted of i.a. injections of bradykinin (BK; 0.5-1 ml, 50 microg/ml) into the arterial circulation of same muscles. Only neurons up to approximately 1mm depth and those that responded to noxious pinch of the gastrocnemius muscles were selected for further analysis. The activity of 16 dorsal horn neurons was recorded extracellularly with high-impedance glass microelectrodes, out of which seven responded to stretch, while 12 neurons responded to bradykinin injections. The bradykinin injections induced three types of responses: excitatory, inhibitory and mixed. The majority of the neurons that showed excitatory and mixed responses to bradykinin were also influenced by stretches applied directly after the bradykinin injection. In these neurons, the stretch usually counteracted the bradykinin-induced response, i.e. shortening and reducing bradykinin-induced excitation and re-exciting the cells after bradykinin-induced inhibition. The mechanism of the stretch modulation is proposed to reside in a segmental spinal control of the nociceptive transmission.
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| 3. |
- Björklund, Martin, et al.
(författare)
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Sensory adaptation after a 2-week stretching regimen of the rectus femoris muscle
- 2001
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Ingår i: Archives of Physical Medicine and Rehabilitation. - : Elsevier BV. - 0003-9993 .- 1532-821X. ; 82:9, s. 1245-1250
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To study the effects of a muscle stretching regimen for the rectus femoris muscle on subjective stretch sensation and range of motion (ROM). DESIGN: A 2 x 2 crossover design comprising 2 treatments and 2 intervention periods. SETTING: A military base in Sweden. PARTICIPANTS: A volunteer sample of 29 male military conscripts divided into 2 groups, with each group subjected to both experimental and control treatments at different time periods. INTERVENTION: Two weeks of supervised stretching (4 times/wk) of the rectus femoris muscle (experimental treatment) and the calf muscles (control treatment). MAIN OUTCOME MEASURES: Subjective rating of the stretch sensation for the anterior aspect of the thigh determined on a category ratio scale. Passive knee flexion ROM determined on each test with the same applied torque, specific for each subject. RESULTS: An additive analysis of variance revealed that the stretch sensation after the experimental treatment was decreased, compared with the control treatment (p <.01). The knee flexion, however, remained the same regardless of the treatment. CONCLUSION: Sensory adaptation seems to be an important mechanistic factor in the effect stretching has on ROM changes. The lack of change in knee flexion suggests that the stretching, as performed in this study, did not influence stiffness of the rectus femoris muscle. Sensory adaptation may also be an underlying mechanism in the alleviating effect of stretching when applied to tired, tender, and painful muscles.
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| 4. |
- Kjellgren, Daniel, et al.
(författare)
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Laminin isoforms in human extraocular muscles
- 2004
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Ingår i: Investigative Ophthalmology and Visual Science. - : Association for Research in Vision and Ophthalmology (ARVO). - 0146-0404 .- 1552-5783. ; 45:12, s. 4233-4239
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To determine the laminin isoform composition of the basement membranes (BMs) in the human extraocular muscles (EOMs) and relate it to the fact that EOMs are spared in laminin alpha2-chain-deficient congenital muscular dystrophy. METHODS: Samples from adult human EOMs and limb muscle were processed for immunocytochemistry, with monoclonal antibodies against laminin chains (Ln) alpha1 to -5, beta1 and -2, and gamma1. Neuromuscular junctions (NMJs) were identified with acetylcholinesterase reaction. The capillary density was measured in sections stained with anti-Lnalpha5. RESULTS: The extrasynaptic BM of the EOM muscle fibers contained Lnalpha2, -beta1, -beta2, and -gamma1, and, in contrast to limb muscle, it also contained Lnalpha4 and -alpha5, to some extent. The distinct laminin composition of the EOMs was confirmed by the presence of Lutheran protein, an alpha5-chain-specific receptor not found in limb muscle. At the NMJs, there was increased expression of Lnalpha4 and expression of Lnalpha2, -alpha5, -beta1, -beta2, and -gamma1 was also maintained. The capillary density was very high (1050 +/- 190 capillaries/mm(2)) in the EOMs and significantly (P < 0.05) higher in the orbital (1170 +/- 180 capillaries/mm(2)) than in the global (930 +/- 110 capillaries/mm(2)) layer. CONCLUSIONS: The human EOMs showed important differences in laminin isoform composition and capillary density when compared with human limb muscle and muscles of other species. The presence of additional laminin isoforms other than laminin-2 in the BM of the extrasynaptic sarcolemma could partly explain the sparing of the EOMs in Lnalpha2-deficient congenital muscular dystrophy.
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| 5. |
- Yu, Ji-Guo, et al.
(författare)
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Evidence for myofibril remodeling as opposed to myofibril damage in human muscles with DOMS : an ultrastructural and immunoelectron microscopic study.
- 2004
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Ingår i: Histochemistry and Cell Biology. - : Springer Science and Business Media LLC. - 0948-6143 .- 1432-119X. ; 121:3, s. 219-227
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Tidskriftsartikel (refereegranskat)abstract
- The myofibrillar and cytoskeletal alterations observed in delayed onset muscle soreness (DOMS) caused by eccentric exercise are generally considered to represent damage. By contrast our recent immunohistochemical studies suggested that the alterations reflect myofibrillar remodeling (Yu and Thornell 2002; Yu et al. 2003). In the present study the same human muscle biopsies were further analyzed with transmission electron microscopy and immunoelectron microscopy. We show that the ultrastructural hallmarks of DOMS, Z-disc streaming, Z-disc smearing, and Z-disc disruption were present in the biopsies and were significantly more frequent in biopsies taken 2-3 days and 7-8 days after exercise than in those from controls and 1 h after exercise. Four main types of changes were observed: amorphous widened Z-discs, amorphous sarcomeres, double Z-discs, and supernumerary sarcomeres. We confirm by immunoelectron microscopy that the main Z-disc protein alpha-actinin is not present in Z-disc alterations or in the links of electron-dense material between Z-discs in longitudinal register. These alterations were related to an increase of F-actin and desmin, where F-actin was present within the strands of amorphous material. Desmin, on the other hand, was seen in less dense regions of the alterations. Our results strongly support that the myofibrillar and cytoskeletal alterations, considered to be the hallmarks of DOMS, reflect an adaptive remodeling of the myofibrils
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