| 1. |
- Larsson, Britt, et al.
(författare)
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The prevalences of cytochrome c oxidase negative and superpositive fibres and ragged-red fibres in the trapezius muscle of female cleaners with and without myalgia and of female healthy controls
- 2000
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Ingår i: Pain. - 1872-6623 .- 0304-3959. ; 84:2-3, s. 379-387
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Tidskriftsartikel (refereegranskat)abstract
- The association of cytochrome c oxidase negative fibres (COX-negative) and ragged-red fibres (RR-fibres) with work related trapezius myalgia has been proposed. Hitherto studies have been small or without control groups. The aim of the present study was to investigate the prevalences of RR-fibres and COX-negative fibres in female cleaners with (n=25) and without (n=23) trapezius myalgia and in clinically healthy female teachers (n=21). The cleaners did mainly floor cleaning requiring monotonous loading on the trapezius muscle. A questionnaire covering background data and aspects of pain (prevalence, duration, intensity and influence on daily living) was answered. Biopsies were obtained from the trapezius muscle by an open surgical technique. The three groups did not differ in prevalence of COX-negative or COX-superpositive (i.e. type-I fibres with extremely strong brownish reaction in both the COX and SDH/COX stainings) fibres. The prevalence of COX-negative fibres was age dependent. Two subgroups of RR-fibres were present when stained for COX; COX-negative (73%) and COX-superpositive (26%) fibres. Forty-two percent of the COX-negative fibres were RR-fibres and 79% of the COX-superpositive were RR-fibres. A significantly (P=0.002) higher proportion of the COX-superpositive fibres in the cleaners were RR-fibres compared to the teachers. Multivariate regression analysis revealed that age, occupation as cleaner and a tender point in the trapezius were significantly associated with increased prevalences of RR-fibres; a cleaner with a tender point had a 4.35 higher prevalence of RR-fibres compared to a teacher without a tender point. No correlations between other pain related variables and prevalence of RR-fibres were noted. In conclusion, RR-fibres but not COX-negative or COX-superpositive fibres were correlated with cleaning work tasks and with a tender point in the trapezius.
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| 2. |
- Östrand, Fredrik, et al.
(författare)
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Stereoisomeric composition of the sex pheromone of the pine sawfly Microdiprion pallipes (Hym., Diprionidae)
- 2003
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Ingår i: Chemoecology. - : Springer Science and Business Media LLC. - 0937-7409 .- 1423-0445. ; 13:3, s. 155-162
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Tidskriftsartikel (refereegranskat)abstract
- The basic chemical structure of the sex pheromone of the pine sawfly Microdiprion pallipes (Fallen) has earlier been identified as the propionate ester of (2S,3S,7 R/S,11 R/S)/(2R,3R,7 R/S,11 R/S)-3,7,11-trimethyl-2-tridecanol. We now report the results from further investigations on the male response to individual stereoisomers and to blends of stereoisomers, both in electroantennographic (EAG) recordings and in field trapping experiments. We also present our attempts to determine the stereochemistry of the compounds present in females of M. pallipes. By comparing gas chromatograms and mass spectra obtained from natural extracts with those from synthetic compounds it was found that the females contain one or more of the four (2S,3S,7 R/S,11 R/S)-3,7,11-trimethyl-2-tridecanol isomers (SS++-1). The active pheromone component is the corresponding propionate ester 2. In EAG experiments, males responded most strongly to five propionate ester samples, namely two four-isomer blends: SS++-2 and SR++-2, and three individual stereoisomers: SSSR-, SRRR- and SRSR-2. In a series of field trapping experiments it was found that males were attracted to the SR++-2 four-isomer blend and to the individual isomer SSSR-2. Based on the EAG-recordings and field responses of males and the stereoisomers found in the females, we suggest that the propionate ester of (2S,3S,7S,11R)-3,7,11-trimethyl-2-tridecanol (SSSR-2) is used as a main component of the sex pheromone in M. pallipes. Apparently the males react to other stereoisomers in addition to that or those produced by the females.
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| 3. |
- Améen, Caroline, 1975, et al.
(författare)
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Effects of gender and GH secretory pattern on sterol regulatory element-binding protein-1c and its target genes in rat liver.
- 2004
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Ingår i: American journal of physiology. Endocrinology and metabolism. - : American Physiological Society. - 0193-1849 .- 1522-1555. ; 287:6
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Tidskriftsartikel (refereegranskat)abstract
- We investigated whether the sexually dimorphic secretory pattern of growth hormone (GH) in the rat regulates hepatic gene expression of sterol regulatory element-binding protein-1c (SREBP-1c) and its target genes. SREBP-1c, fatty acid synthase (FAS), and glycerol-3-phosphate acyltransferase (GPAT) mRNA were more abundant in female than in male livers, whereas acetyl-CoA carboxylase-1 (ACC1) and stearoyl-CoA desaturase-1 (SCD-1) were similarly expressed in both sexes. Hypophysectomized female rats were given GH as a continuous infusion or as two daily injections for 7 days to mimic the female- and male-specific GH secretory patterns, respectively. The female pattern of GH administration increased the expression of SREBP-1c, ACC1, FAS, SCD-1, and GPAT mRNA, whereas the male pattern of GH administration increased only SCD-1 mRNA. FAS and SCD-1 protein levels were regulated in a similar manner by GH. Incubation of primary rat hepatocytes with GH increased SCD-1 mRNA levels and decreased FAS and GPAT mRNA levels but had no effect on SREBP-1c mRNA. GH decreased hepatic liver X receptor-alpha (LXRalpha) mRNA levels both in vivo and in vitro. Feminization of the GH plasma pattern in male rats by administration of GH as a continuous infusion decreased insulin sensitivity and increased expression of FAS and GPAT mRNA but had no effect on SREBP-1c, ACC1, SCD-1, or LXRalpha mRNA. In conclusion, FAS and GPAT are specifically upregulated by the female secretory pattern of GH. This regulation is not a direct effect of GH on hepatocytes and does not involve changed expression of SREBP-1c or LXRalpha mRNA but is associated with decreased insulin sensitivity.
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| 4. |
- Eberhardt, Kerstin, et al.
(författare)
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Measuring health related quality of life in patients with rheumatoid arthritis--reliability, validity, and responsiveness of a Swedish version of RAQoL.
- 2002
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Ingår i: Scandinavian Journal of Rheumatology. - : Informa UK Limited. - 1502-7732 .- 0300-9742. ; 31:1, s. 6-12
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To adapt the Rheumatoid Arthritis Quality of Life (RAQoL) questionnaire for Swedish patients and evaluate psychometric properties in a prospective study. METHODS: Reliability was assessed in 61 patients filling in RAQoL two times with one week's interval. 114 patients completed RAQoL and Nottingham Health Profile (NHP) on 2-3 occasions 6 months apart. Validity was evaluated comparing RAQoL-scores to disease-related variables and NHP subscales. Standardized response mean was applied to calculate responsiveness with the RA-related variables as external indicators of change. RESULTS: Test-retest reliability was high and internal consistency sufficient. RAQoL correlated as expected to NHP section scores. In a multivariate model the Stanford Health Assessment Questionnaire disability index (HAQ) and general health could explain 40% and disease activity measures 13% of the variance of RAQoL. Correlations between change scores of clinical variables and RAQoL and NHP were weak but positive. Standardized response means regarding change of disease activity, HAQ, and general health were small but in the same range for both RAQoL and NHP. CONCLUSION: The Swedish RAQoL had similar measurement properties as the original version. However, responsiveness regarding condition specific measures was not better than for the generic instrument NHP.
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| 5. |
- Frost, Britt-Marie, et al.
(författare)
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In vitro activity of the novel cytotoxic agent CHS 828 in childhood acute leukemia
- 2002
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Ingår i: Anti-Cancer Drugs. - 0959-4973 .- 1473-5741. ; 13:7, s. 735-742
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Tidskriftsartikel (refereegranskat)abstract
- CHS 828, a pyridyl cyanoguanidine, is a new drug candidate now in phase I/II trials, that has shown promising anticancer activity in experimental tumor models and primary cultures of cancer cells from patients. In this study the fluorometric microculture cytotoxicity assay was used for evaluation of CHS 828 in primary cell cultures from children with acute leukemia. The activity of and interaction with the standard drugs, doxorubicin, melphalan, etoposide and cytosine arabinoside (Ara-C), were also assessed. Samples from 65 patients, 42 with acute lymphocytic leukemia (ALL) and 23 with acute myelocytic leukemia (AML) were tested with 72-h continuous drug exposure. There was 50% cell kill at very low CHS 828 concentrations; median IC50 was 0.01 microM in ALL and 0.03 in AML samples (NS) with large interindividual variability in both groups. ALL samples were significantly more sensitive than AML samples to melphalan, doxorubicin and etoposide, but not to Ara-C. In AML samples, combinations between CHS 828 and each of the four standard drugs resulted in significantly lower cell survival than either drug alone. This was also observed in ALL samples, except for Ara-C. Using the additive interaction model, CHS 828 showed a synergistic effect with melphalan in 67%, doxorubicin in 47%, etoposide in 38% and Ara-C in 14% of AML samples. In most ALL samples subadditive effects were found. Further exploration of CHS 828 in childhood leukemia is warranted, especially in AML.
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| 6. |
- Frost, Britt-Marie, et al.
(författare)
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Increased in vitro cellular drug resistance is related to poor outcome in high-risk childhood acute lymphoblastic leukaemia
- 2003
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Ingår i: British Journal of Haematology. - : Wiley. - 0007-1048 .- 1365-2141. ; 122, s. 376-
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Tidskriftsartikel (refereegranskat)abstract
- Summary. We determined the in vitro cellular drug resistance in 370 children with newly diagnosed acute lymphoblastic leukaemia (ALL). The resistance to each of 10 drugs was measured by the fluorometric microculture cytotoxicity assay (FMCA) and was related to clinical outcome. The median follow-up time was 41 months. Risk-group stratified analyses indicated that in vitro resistance to dexamethasone, doxorubicin and amsacrine were each significantly related to the probability of disease-free survival. In the high-risk (HR) group, increased in vitro resistance to dexamethasone (P = 0·014), etoposide (P = 0·025) and doxorubicin (P = 0·05) was associated with a worse clinical outcome. Combining the results for these drugs provided a drug resistance score with an independent prognostic significance superior to that of any other factor studied, with a relative risk of relapse in the most resistant group 9·8 times that in the most sensitive group (P = 0·007). The results in the intermediate-risk (IR) and standard-risk (SR) groups were less clear cut. In conclusion, our data indicate that in vitro testing of cellular drug resistance can be used to predict the clinical outcome in HR ALL, while the final evaluation of the results in IR and SR patients must await longer follow-up.
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| 7. |
- Frost, Britt-Marie, et al.
(författare)
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Translocation t(12;21) is related to in vitro cellular drug sensitivity to doxorubicin and etoposide in childhood acute lymphoblastic leukemia
- 2004
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Ingår i: Blood. - Washington : American society of hematology. - 0006-4971 .- 1528-0020. ; 104:8, s. 2452-2457
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Tidskriftsartikel (refereegranskat)abstract
- The t(12;21) (p13;q22) translocation resulting in ETV6/RUNX1 (previously named TEL/AML1) gene fusion is present in about 25% of children with precursor B-lineage acute lymphoblastic leukemia (B-ALL). We successfully tested 275 precursor BALL samples from children aged 1 to 17 years to determine the relation between t(12;21) and in vitro cellular drug resistance, measured by the fluorometric microculture cytotoxicity assay (FMCA). Samples from 83 patients (30%) were positive for t(12;21). The ETV6/RUNX1(+) samples were significantly more sensitive than ETV6/RUNX1(-) samples to doxorubicin, etoposide, amsacrine, and dexamethasone, whereas the opposite was true for cytarabine. After matching for unevenly distributed patient characteristics, that is, excluding patients with high hyperdiploidy (> 51 chromosomes), t(g;22), t(1;19), or 11q23 rearrangement, the ETV6/RUNX1(+) samples remained significantly more sensitive to doxorubicin (P = .001) and etoposide (P = .001). For the other drugs tested (amsacrine, cytarabine, dexamethasone, prednisolone, vincristine, 6-thioguanine, and 4-hydroper-oxy-cyclophosphamide), no significant difference in cellular drug sensitivity was found. In conclusion, we found that the presence of the t(12;21) translocation in childhood precursor B-ALL is associated with a high tumor cell sensitivity to doxorubicin and etoposide. High throughput techniques should now be used to elucidate the cellular mechanisms by which ETV6/RUNX1 gene fusion is linked to increased sensitivity to these drugs.
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| 8. |
- Gabrielsson, Britt, 1957, et al.
(författare)
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High expression of complement components in omental adipose tissue in obese men.
- 2003
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Ingår i: Obesity research. - : Wiley. - 1071-7323 .- 1550-8528. ; 11:6, s. 699-708
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Accumulation of visceral fat is recognized as a predictor of obesity-related metabolic disturbances. Factors that are predominantly expressed in this depot could mediate the link between visceral obesity and associated diseases. RESEARCH METHODS AND PROCEDURES: Paired subcutaneous and omental adipose tissue biopsies were obtained from 10 obese men. Gene expression was analyzed by DNA microarrays in triplicate and by real-time polymerase chain reaction. Serum C3 and C4 were analyzed by radial immunodiffusion assays in 91 subjects representing a cross section of the general population. Body composition was measured by computerized tomography. RESULTS: Complement components C2, C3, C4, C7, and Factor B had higher expression in omental compared with subcutaneous adipose tissue ( approximately 2-, 4-, 17-, 10-, and 7-fold, respectively). In addition, adipsin, which belongs to the alternative pathway, and the classical pathway components C1QB, C1R, and C1S were expressed in both depots. Analysis of tissue distribution showed high expression of C2, C3, and C4 in omental adipose tissue, and only liver had higher expression of these genes. Serum C3 levels correlated with both visceral and subcutaneous adipose tissue in both men (r = 0.65 and p < 0.001 and r = 0.52 and p < 0.001, respectively) and women (r = 0.34 and p = 0.023 and r = 0.49 and p < 0.001, respectively), whereas C4 levels correlated with only visceral fat in men (r = 0.36, p = 0.015) and with both depots in women (visceral: r = 0.58, p < 0.001; and subcutaneous: r = 0.51, p < 0.001). DISCUSSION: Recent studies show that the metabolic syndrome is associated with chronically elevated levels of several immune markers, some of which may have metabolic effects. The high expression of complement genes in intra-abdominal adipose tissue might suggest that the complement system is involved in the development of visceral adiposity and/or contributes to the metabolic complications associated with increased visceral fat mass.
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| 9. |
- Gainer, Erin, et al.
(författare)
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Bringing emergency contraception over the counter : experiences of nonprescription users in France, Norway, Sweden and Portugal.
- 2003
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Ingår i: Contraception. - 0010-7824 .- 1879-0518. ; 68:2, s. 117-24
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Tidskriftsartikel (refereegranskat)abstract
- Emergency contraceptive pills are now available on a nonprescription basis in over 25 countries worldwide. In an effort to learn about women's experiences with this new means of emergency contraception (EC) service delivery, we conducted focus-group discussions with nonprescription EC users from France, Norway, Portugal and Sweden. Participants from these countries overwhelming supported pharmacy access to EC, explaining that pharmacy delivery facilitated rapid access to the method. Despite expressing mixed reviews of the counseling given by the providing pharmacists, participants reported that they knew how use the method safely and properly. Most indicated that the package insert was easy to understand and adequately answered the majority of their questions. Participants described the EC experience as a motivating factor that, in many cases, has led to more consistent use of regular contraceptive methods. These data are valuable to policy-makers and institutions interested in learning more about the safety and acceptability of nonprescription access to emergency contraceptive pills.
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| 10. |
- Grodzinsky, Ewa, 1958-, et al.
(författare)
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Point-of-care testing has a limited effect on time to clinical decision in primary health care
- 2004
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Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 64:6, s. 547-551
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate the clinical logistics of laboratory routines at primary health care centres (PHCs). Design and methods: Prospective registration was carried out for each PHC using questionnaires during 2-week intervals between the end of November 2001 and mid-January 2002. The study included 9 PHCs in the county of Östergötland and 4 in the county of Jönköping, Sweden, with different numbers of blood tests analysed using point-of-care testing (POCT). Data for B-glucose, HbA1c, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), thyroid-stimulating hormone (TSH), T4, cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides were collected. Main outcome measures were median time from sampling to available test result (TATa) and median time from sampling to clinical decision (TATd), and the proportion of patients informed of the outcome of the blood test in question during the sampling occasion. Results: A total of 3542 samples were collected. The median TATa showed that B-glucose, ESR and CRP were immediately analysed at all 13 PHCs. For the other tests, TATa varied from immediately to about two days. The median TATd varied from immediately to about a week. When POCT was used, 30% of the patients were informed about the outcome of the test during the sampling occasion. Conclusion: POCT has a limited effect on the clinical logistics in PHCs.
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| 11. |
- Herrmann, Björn, et al.
(författare)
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Comparison of a duplex quantitative real-time PCR assay and the COBAS Amplicor CMV Monitor test for detection of cytomegalovirus
- 2004
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Ingår i: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 42:5, s. 1909-14
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Tidskriftsartikel (refereegranskat)abstract
- A duplex quantitative real-time PCR (qPCR) assay was designed to detect both the polymerase gene (pol) and the glycoprotein gene (gB) of cytomegalovirus (CMV). The detection limit of the qPCR was determined to be 1 to 3 copies/reaction and the linear measure interval was 10(3) to 10(8) copies/ml. The qPCR system was compared to the COBAS Amplicor CMV Monitor test (COBAS) by an analysis of 138 plasma samples. Both systems detected CMV in 71 cases and had negative results for 33 samples. In addition, 34 samples were positive by qPCR and negative by the COBAS assay, but in no case was the COBAS result positive and the qPCR result negative. Thus, qPCR detected 48% more positive cases than the COBAS method. For samples with > or = 10(5) copies/ml by qPCR, a saturation effect was seen in the COBAS assay and quantification required dilution. Copy numbers for pol and gB by qPCR generally agreed. However, the reproducibility of qPCR assays and the need for an international standard are discussed. Discrepant copy numbers for pol and gB by qPCR were found for samples from two patients, and sequence analysis revealed that the corresponding CMV strains were mismatched at four nucleotide positions compared with the gB fragment primer sequences. In conclusion, a duplex qPCR assay in a real-time format facilitates quantitative measurements and minimizes the risk of false-negative results.
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| 12. |
- Kadi, Fawzi, et al.
(författare)
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The effects of physical activity and estrogen treatment on rat fast and slow skeletal muscles following ovariectomy.
- 2002
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Ingår i: Journal of muscle research and cell motility. - Dordrecht : Springer. - 0142-4319 .- 1573-2657. ; 23:4, s. 335-9
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Tidskriftsartikel (refereegranskat)abstract
- Decreased estrogen production is associated with changes in the skeletal, cardiovascular and muscular systems. At the level of skeletal muscles, it has been shown that a reduction in force production occurs at menopause but the underlying mechanisms are still unknown. The aim of the study was to investigate the effects of ovariectomy on myosin heavy chain (MyHC) composition. Additionally, we studied the effects of physical activity and the combined effects of physical activity and estrogen treatment on MyHC content in ovariectomised (OX) animals. Twenty-five rats were randomly assigned to five different groups: controls, runners, OX, ovariectomised runners and ovariectomised runners receiving estrogen. Exercise consisted of voluntary running for 5 weeks. Two muscles were analysed: m. extensor digitorum longus, EDL, (fast muscle) and m. soleus (slow muscle). MyHC content was analysed on 8% gel electrophoresis. The level of running activity is reduced in OX animals and estrogen administration is associated with the normalisation of the level of physical activity. Ovariectomy induces a shift from fast to slow MyHC isoforms in both the soleus and EDL. When OX animals are allowed to run, alterations in MyHC isoforms are still observed in the EDL but not in the soleus. When physical activity is combined with estrogen treatment no alterations are observed in both muscles. In conclusion, this study shows that ovariectomy induces alterations in the contractile properties of skeletal muscles and that physical activity in combination with estrogen treatment are associated with the maintenance of slow and fast muscle characteristics.
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| 13. |
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| 14. |
- Kasrayan, Alex, et al.
(författare)
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Enhancement by effectors and substrate nucleotides of R1-R2 interactions in Escherichia coli class Ia ribonucleotide reductase.
- 2004
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Ingår i: J Biol Chem. - 0021-9258. ; 279:30, s. 31050-7
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Ribonucleotide reductases are a family of essential enzymes that catalyze the reduction of ribonucleotides to their corresponding deoxyribonucleotides and provide cells with precursors for DNA synthesis. The different classes of ribonucleotide reductase are distinguished based on quaternary structures and enzyme activation mechanisms, but the components harboring the active site region in each class are evolutionarily related. With a few exceptions, ribonucleotide reductases are allosterically regulated by nucleoside triphosphates (ATP and dNTPs). We have used the surface plasmon resonance technique to study how allosteric effects govern the strength of quaternary interactions in the class Ia ribonucleotide reductase from Escherichia coli, which like all class I enzymes has a tetrameric alpha(2) beta(2) structure. The component alpha(2)called R1 harbors the active site and two types of binding sites for allosteric effector nucleotides, whereas the beta(2) component called R2 harbors the tyrosyl radical necessary for catalysis. Our results show that only the known allosteric effector nucleotides, but not non-interacting nucleotides, promote a specific interaction between R1 and R2. Interestingly, the presence of substrate together with allosteric effector nucleotide strengthens the complex 2-3 times with a similar free energy change as the mutual allosteric effects of substrate and effector nucleotide binding to protein R1 in solution experiments. The dual allosteric effects of dATP as positive allosteric effector at low concentrations and as negative allosteric effector at high concentrations coincided with an almost 100-fold stronger R1-R2 interaction. Based on the experimental setup, we propose that the inhibition of enzyme activity in the E. coli class Ia enzyme occurs in a tight 1:1 complex of R1 and R2. Most intriguingly, we also discovered that thioredoxin, one of the physiological reductants of ribonucleotide reductases, enhances the R1-R2 interaction 4-fold.
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| 15. |
- Larsson, Britt, et al.
(författare)
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Blood supply and oxidative metabolism in muscle biopsies of female cleaners with and without myalgia
- 2004
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Ingår i: The Clinical Journal of Pain. - : Ovid Technologies (Wolters Kluwer Health). - 0749-8047 .- 1536-5409. ; 20:6, s. 440-446
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Pathomechanisms of work-related myalgia are poorly understood. Myalgia is thought to be caused by excitation of nociceptors present in the muscular tissue but not in the muscle fiber itself. Muscle contraction in combination with hypoxia is known to excite nociceptors. Morphologic analysis can contribute to the knowledge of the excitation of nociceptors. This study thoroughly examines the morphology of the trapezius muscle's capillary supply and signs of disturbed oxidative metabolism to understand their role in work-related myalgia. METHODS: Surgical trapezius muscle biopsies were obtained from 25 female cleaners with long-standing work-related myalgia, 25 female cleaners without trapezius myalgia, and 21 healthy teachers. Enzyme and immunohistochemical stainings were performed to highlight fibers with aberrant intermyofibrillar patterns, indicating a disturbed oxidative metabolism (also known as moth-eaten fibers) and a disturbed capillary supply of different fibers. RESULTS: A significantly lower number of capillaries per fiber area in cleaners suffering from myalgia compared with cleaners without trapezius myalgia was found. Moth-eaten fibers were found in the 3 groups, but these fibers were significantly more prevalent in the groups of cleaners than in the healthy teacher group. CONCLUSION: This work indicates that the capillary supply of trapezius is affected in work-related trapezius myalgia. More studies are needed to understand possible mechanisms that would explain the occurrence of moth-eaten fibers.
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| 16. |
- Larsson, Britt, et al.
(författare)
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Fibre type proportion and fibre size in trapezius muscle biopsies from cleaners with and without myalgia and its correlation with ragged red fibres, cytochrome-c-oxidase-negative fibres, biomechanical output, perception of fatigue, and surface electromyography during repetitive forward flexions
- 2001
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Ingår i: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6327 .- 1439-6319. ; 84:6, s. 492-502
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Tidskriftsartikel (refereegranskat)abstract
- In the literature enlarged/increased cross-sectional area (CSA) of type I muscle fibres has been reported as a morphological mark of work-related localised myalgia in the descending part of the trapezius muscle of women. These studies did not use enough subjects or lacked an adequate control group. The recording of surface electromyograms (EMG) is central to the research field of work-related myalgia. However, the influence of intrinsic muscle properties such as the effect of muscle fibre distribution upon surface EMG has to be better understood in order properly to evaluate this method as a possible diagnostic and preventive tool. This study had two aims. Firstly, it investigated the muscle fibre distribution and CSA in work-related myalgia in trapezius muscles. Secondly, the multivariate relationships among muscle morphology and histochemistry [ragged-red (RR) fibres, and cytochrome-c-oxidase-negative-fibre changes] EMG, perceived fatigue, and biomechanical output of shoulder flexions were analysed. The raw data have been presented in an earlier study. The participants in this study were 25 female cleaners with work-related myalgia of the trapezius muscle and 25 female cleaners not experiencing work-related myalgia of this muscle. The control group comprised 21 healthy female teachers who had not been exposed to highly repetitive work or static muscle work. Smaller CSA of type II fibres were found in cleaners compared to teachers. In this study the CSA of type I fibres of the trapezius muscles associated with myalgia were no greater than in muscles without myalgia. The prevalence of RR fibres together with age, fibre type proportions, CSA and working as a cleaner correlated with the ability to relax as recorded electromyographically. The relative mean frequency of the EMG of the trapezius muscle correlated with the prevalence of RR fibres, but it did not correlate with the proportions and CSA of different fibre types. Low biomechanical outputs and low signal amplitude increases of the EMG during the test were associated with high proportions of type -IIB fibres. The smaller CSA of type II fibres in cleaners might have reflected a different muscle activation pattern due to different occupational demands in cleaners than in teachers. Morphological or histopathological variables can influence the three EMG variables investigated.
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| 17. |
- Larsson, Britt-Marie
(författare)
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Induction of a non-allergic inflammation in the human respiratory tract by organic dust
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Swine farming is an occupation associated with high exposure levels to organic dust, but gases such as ammonia and hydrogen sulphide are also contributing to the potentially hazardous exposure. The prevalences for respiratory symptoms, chronic or work-related, are increased among swine farmers, compared to both the normal population as well as other farming categories. Healthy subjects, previously unexposed to farming environment, developed an intense airway inflammation following three hours of exposure during weighing pigs or during cleaning procedure of an evacuated stable using a high-pressure cleaner. The inflammation was characterised by an increased bronchial responsiveness to methacholine between approximately 1 to 3 dose-doubling steps as well as an extensive migration of inflammatory cells, predominantly neutrophils, into the upper and lower airways. Elevated levels of the chemotactic factor IL-8 found in lavage fluid from the airways most likely achieve this accumulation of neutrophils. The significant correlation between changes in IL-8 levels and increased concentrations of neutrophils found in nasal lavage fluid supports such a theory. Other chemoattractants, could however, also contribute to the recruitment of neutrophils, since increased levels of LTB4 were demonstrated in the upper airways. Other signs of an induced inflammatory reaction were increased post-exposure levels of the inflammatory cytokine IL-6 in nasal lavage fluid and peripheral blood. Involvement of cysteinyl-leukotrienes (cys-LTs) was also established. A local production of LTE4 was detected in the upper airways following exposure as well as an increased whole body formation of cys-LTs measured as increased levels of urinary LTE4. The cys-LTs were hypothesised to be contributing factors to the increased bronchial responsiveness. The intervention study with an inhibitor of leukotriene biosynthesis could not clarify this assumption due to an insufficient inhibitory effect on urinary LTE4 excretion. Signs of mast cell activation were also demonstrated by increased levels of PGD2 , a mast cell mediator, measured as increased urinary levels of the PGD2 metabolite 9a, 11b-PGF2. No relationship between measured inflammatory mediators and increased bronchial responsiveness could be detected, indicating that the airway response was not caused directly by mediator release. Instead, swelling of the airway mucosa and increased secretions due to the general inflammatory reaction could lead to an airway narrowing that would enhance the post-exposure response to methacholine. Endotoxin has been postulated as the main factor behind respiratory illness in the farming environment. This hypothesis is not supported by our studies. Other agents, originating from Gram-positive bacteria are probably important contributors to the induction of the inflammatory reaction after swine house exposure. The perhaps most intriguing finding regarding exposure in this thesis, was the discovery that even if the healthy volunteers were equipped with a half mask with a particle filter during the exposure, they still responded with an increased bronchial responsiveness, although somewhat attenuated. However, the respiratory device showed better effect regarding reactions in the upper airways. This implicates a role for gases (e.g. ammonia) in the development of increased bronchial responsiveness in healthy, previously unexposed, subjects following an acute exposure in the swine farm environment. On the other hand, the particles seem to have a more prominent role for the reactions in the upper airways.
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| 18. |
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| 19. |
- Larsson, Britt, et al.
(författare)
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Mechanical performance and electromyography during repeated maximal isokinetic shoulder forward flexions in female cleaners with and without myalgia of the trapezius muscle and in healthy controls
- 2000
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Ingår i: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6327 .- 1439-6319. ; 83:4-5, s. 257-267
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Tidskriftsartikel (refereegranskat)abstract
- This cross-sectional study aimed at investigating the influence of occupational exposure to static and highly repetitive work involving the neck and shoulder muscles, myalgia of and tender point in the trapezius muscle on biomechanical output, and electromyogram (EMG) variables (mean frequency MNF, signal amplitude and ability to relax) during maximal forward flexions of the shoulder muscles. Groups of 25 cleaners suffering from chronic myalgia of the trapezius muscle, 25 cleaners free from myalgia of the trapezius muscle and 21 teachers performed 150 forward flexions using an isokinetic dynamometer. Perception of fatigue was reported and surface EMG was recorded from four muscles during the endurance test. The cleaners were stronger than the teachers. Myalgia was associated with lower levels of endurance and a high degree of perceived fatigue. The ability to relax the trapezius muscle decreased with age and was even lower in cleaners with and without myalgia. Higher MNF of the deltoid muscle but not of the trapezius muscle was found in the group suffering from myalgia compared to the groups free from myalgia. This cross-sectional study indicated that myalgia of the trapezius muscle did not influence the strength but did influence the endurance of the forward flexor muscles of cleaners. The observed decrease in the ability to relax the trapezius muscle in cleaners compared to healthy teachers might be indicative of a future insufficiency in the muscle. Prospective studies are needed to define the significance of the results presented here.
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| 20. |
- Larsson, Britt
(författare)
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Morphological and electromyographical studies of trapezius myalgia in cleaners
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Pathomechanisms of work-related myalgia are poorly understood. Myalgia is caused by exitation of nociceptors present in the muscular tissue but not in the muscle fibres themselves. Morphological analysis can contribute to knowledge of excitation of nociceptors. Surface EMG is a widely used method in the research field of ergonomics. Knowledge of influence of myalgia, occupation, age and intrinsic properties on the surface EMG is limited. Twenty-five female cleaners with long standing work related myalgia, 25 female cleaners without trapezius myalgia and 21 healthy teachers participated in the study. All participants were clinically examined to reach the diagnosis trapezius myalgia. Surface EMG was recorded during an isokinetic endurance test of shoulder forward flexors. Biomechanical output and the EMG parameters mean power frequency and root mean square (RMS) were calculated. The RMS ratio between passive and active phases of contractions were calculated to assess the ability to relax between contractions. Surgical trapezius muscle biopsies were obtained from all subjects. Enzym- and immunohistochemical stainings were performed to visualize different fibre types, capillary density, fibres with subsarcolemmal accumulations of mitochondria, cytochrome oxidase deficient fibres and fibres with a disorganization of mitochondrial distribution. Occupational cleaning work, myalgia and age contributed to the total variation of biomechanical output and EMG parameters. Histopathological findings and the relative distribution of myosin heavy chains in the trapezius muscle influenced the surface EMG signal. The capillary supply but not the morphological characteristics and functional properties of the trapezius muscle may be associated with myalgia. Histochemical and enzym histochemical alterations indicating a disturbed oxidative metabolism were linked to heavy work load on the trapezius muscle.
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| 21. |
- Larsson, Britt, et al.
(författare)
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Myosin heavy chain isoforms influence surface EMG parameters : A study of the trapezius muscle in cleaners with and without myalgia and in healthy teachers
- 2002
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Ingår i: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6319 .- 1439-6327. ; 87:6, s. 481-488
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Tidskriftsartikel (refereegranskat)abstract
- The present study had two aims: (1) to investigate potential differences in proportion of myosin heavy chain isoforms in the trapezius muscle between female cleaners with and without trapezius myalgia and healthy teachers, and (2) to elucidate if myosin heavy chain composition and surface electromyogram (EMG) during an isokinetic endurance test of shoulder flexors are significantly related. The subjects were divided into three groups: (1) 25 female cleaners with diagnosed work-related trapezius myalgia, (2) 25 female cleaners without work-related trapezius myalgia, (3) a control group of 21 healthy female teachers who were not exposed to repetitive or static muscle work. All subjects performed a test involving 150 forward flexions using an isokinetic dynamometer. During the test surface EMG was recorded from the trapezius muscle. Muscle samples were obtained from the descending part of the trapezius muscle. The fibre type area percentage based on ATPase staining and the proportions of different MHC isoforms as determined by gel electrophoresis. The trapezius was dominated by MHC I (71%), followed by MHC IIA (22-24%), and MHC IIX (5-7%), no significant differences between the three groups of subjects were found. The proportion of MHC I correlated negatively with MHC IIA (r=-0.78, P<0.001) and MHC IIX (r= -0.53, P<0.001). Significant correlations existed between the proportion of the MHC isoforms and the corresponding proportion of the fibre type area, 27-45% of the variance was explained. The multivariate analysis of the three groups of subjects revealed that MHC variables showed intercorrelations with EMG (both amplitude and frequency variables). However, the directions of the relationships differed among the three groups, the cleaners with myalgia and the teachers showed the greatest similarities in patterns. Intrinsic muscle properties appear to influence the frequency content of the EMG, which is in contrast to some of the theoretical models of the EMG. Our data could suggest that monotonous work such as professional cleaning can change the relationships between muscle structure and the frequency content of the EMG.
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| 22. |
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| 23. |
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| 24. |
- Larsson-Birgander, Pernilla, et al.
(författare)
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Mutant R1 proteins from Escherichia coli class Ia ribonucleotide reductase with altered responses to dATP inhibition.
- 2004
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Ingår i: J Biol Chem. - 0021-9258. ; 279:15, s. 14496-501
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Aerobic ribonucleotide reductase from Escherichia coli regulates its level of activity by binding of effectors to an allosteric site in R1, located to the proposed interaction area of the two proteins that comprise the class I enzyme. Activity is increased by ATP binding and decreased by dATP binding. To study the mechanism governing this regulation, we have constructed three R1 proteins with mutations at His-59 in the activity site and one R1 protein with a mutation at His-88 close to the activity site and compared their allosteric behavior to that of the wild type R1 protein. All mutant proteins retained about 70% of wild type enzymatic activity. We found that if residue His-59 was replaced with alanine or asparagine, the enzyme lost its normal response to the inhibitory effect of dATP, whereas the enzyme with a glutamine still managed to elicit a normal response. We saw a similar result if residue His-88, which is proposed to hydrogen-bond to His-59, was replaced with alanine. Nucleotide binding experiments ruled out the possibility that the effect is due to an inability of the mutant proteins to bind effector since little difference in binding constants was observed for wild type and mutant proteins. Instead, the interaction between proteins R1 and R2 was perturbed in the mutant proteins. We propose that His-59 is important in the allosteric effect triggered by dATP binding, that the conserved hydrogen bond between His-59 and His-88 is important for the communication of the allosteric effect, and that this effect is exerted on the R1/R2 interaction.
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| 25. |
- Larsson-Lund, Maria, et al.
(författare)
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Patients' perceptions of their participation in rehabilitation planning and professionals' view of their strategies to encourage it
- 2001
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Ingår i: Occupational Therapy International. - : Wiley. - 0966-7903 .- 1557-0703. ; 8:3, s. 151-167
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Tidskriftsartikel (refereegranskat)abstract
- The purposes of this descriptive study were threefold: first, to describe how patients perceived their participation in the planning of their rehabilitation; second, to describe nurses' and occupational therapists' view of the strategies they used to encourage patients' participation; and third, to compare the perceptions of the two groups. Data was collected through semi-structured interviews with 57 hospitalized patients, 39 nurses and 11 occupational therapists. On the basis of the data patients were categorized as (a) 'relinquishers', (b) 'participants', and (c) 'occasional participants'. Professionals were categorized as 'information providers' and 'rehabilitation practitioners'. The strategies used by the professionals to encourage patient participation were approximately the same irrespective of patient category. It is suggested that professionals need to be sensitive to the patient's desire to participate in the planning of a rehabilitation programme. Further research is recommended to investigate circumstances affecting patients' participation and which strategies professionals can use to encourage their participation
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| 26. |
- Logan, Derek, et al.
(författare)
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A metal-binding site in the catalytic subunit of anaerobic ribonucleotide reductase.
- 2003
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Ingår i: Proc Natl Acad Sci U S A. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 100:7, s. 3826-31
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A Zn(Cys)(4) center has been found in the C-terminal region of the crystal structure of the anaerobic class III ribonucleotide reductase (RNR) from bacteriophage T4. The metal center is structurally related to the zinc ribbon motif and to rubredoxin and rubrerythrin. Mutant enzymes of the homologous RNR from Escherichia coli, in which the coordinating cysteines, conserved in almost all known class III RNR sequences, have been mutated into alanines, are shown to be inactive as the result of their inability to generate the catalytically essential glycyl radical. The possible roles of the metal center are discussed in relationship to the currently proposed reaction mechanism for generation of the glycyl radical in class III RNRs.
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| 27. |
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| 28. |
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| 29. |
- Nilsson, Cecilia, et al.
(författare)
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Maternal endotoxemia results in obesity and insulin resistance in adult male offspring.
- 2001
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Ingår i: Endocrinology. - 0013-7227. ; 142:6, s. 2622-30
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Tidskriftsartikel (refereegranskat)abstract
- Events in utero appear to be important factors contributing to the development of somatic disorders at adult age. The aim of this study was to examine whether maternal immune challenge would be followed at adult age by metabolic and endocrine abnormalities in the offspring. Pregnant rats were given injections of either endotoxin (Escherichia coli lipopolysaccharide; 0.79 mg/kg, ip) or vehicle on days 8, 10, and 12 of gestation. Adult male offspring to lipopolysaccharide-exposed dams were heavier than controls (P < 0.05) and showed increased adipose tissue weights (P < 0.05), elevated food intake (P < 0.05), and increased circulating leptin (P < 0.01). The effect of insulin on glucose uptake was reduced, as measured by an euglycemic hyperinsulinemic clamp technique (P < 0.05). Serum levels of 17beta-estradiol and progesterone were elevated (P < 0.01 and P < 0.05, respectively). Baseline levels of corticosterone were normal, but the corticosterone response to stress was attenuated (P < 0.05), and hippocampal glucocorticoid receptor protein was up-regulated (P < 0.05). Female offspring were uninfluenced, except for increased testosterone levels (P < 0.05), increased baseline corticosterone levels (P < 0.05), and enlargement of heart and adrenals (P < 0.05). The results indicate that maternal endotoxemia leads to obesity, insulin resistance, and high serum levels of leptin in the adult male offspring. This study reports a novel animal model of obesity with features of the metabolic syndrome.
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| 30. |
- Nilsson, Gunilla, et al.
(författare)
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Patients' experiences of illness, operation and outcome with reference to gastro-oesophageal reflux disease.
- 2002
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Ingår i: Journal of Advanced Nursing. - : Wiley. - 0309-2402 .- 1365-2648. ; 40:3, s. 307-15
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Describing the illness-story from a patient perspective could increase understanding of living with a chronic disease for health professionals and others, facilitate decision-making about treatment and enhance information about the outcome from a patient perspective. AIM: To illuminate patients' illness experiences of having a gastro-oesophageal reflux disease (GORD), going through surgery and the outcome. METHODS: Twelve patients were interviewed 5 years after having had the operation; six patients had had fundoplication via laparoscopy and six via open surgery. Each patient was asked to talk openly about their experiences, thoughts, feelings and consequences of living with the illness, going through surgery and the period from surgery to the day of interview. A qualitative content analysis was performed concerning the context of the data and its meaning. FINDINGS: Three central categories were identified and nine subcategories: living with GORD- symptoms of the disease affecting daily living, taking medicines, work, family and social life; concerns related to surgery- decision-making about the operation, influence by physicians; life after the operation- outcomes and consequences, side-effects and complications of the operation, sick leave, information and sharing experiences with future patients. All patients were free from symptoms of the illness after surgery independent of type of surgery, but side-effects from surgical treatment varied individually. Interviewees would have liked information concerning side-effects after surgery from previous patients. CONCLUSIONS: This study contributes to knowledge about patients' long-term suffering, their control of symptoms and how they have tried to cure themselves, but also about their concerns about surgery and the importance of surgical treatment to their quality of life. They wanted information about treatment, outcome and consequences, not only from a health care perspective but also from previous patients having had the same treatment.
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| 31. |
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| 32. |
- Rosendahl, Lars, 1971-, et al.
(författare)
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Increase in muscle nociceptive substances and anaerobic metabolism in patients with trapezius myalgia : microdialysis in rest and during exercise
- 2004
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Ingår i: Pain. - : Ovid Technologies (Wolters Kluwer Health). - 0304-3959 .- 1872-6623. ; 112:3, s. 324-334
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Tidskriftsartikel (refereegranskat)abstract
- Local metabolic changes are suggested to be involved in muscle pain development in humans. Nineteen women with chronic work-related trapezius myalgia (TM) and 20 healthy female controls (CON) were studied during baseline rest, 20 min repetitive low-force exercise, and 120 min recovery. Interstitial serotonin (5-HT), glutamate, lactate, pyruvate, and blood flow were determined by microdialysis in the trapezius muscle. Baseline pressure pain threshold (PPT) was lower (143+/-18 (TM) vs. 269+/-17 (CON) kPa) (mean +/- SEM), pain intensity (visual analogue scale, VAS) higher (33+/-5 vs. 2+/-1 mm), muscle 5-HT higher (22.9+/-6.7 vs. 3.8+/-1.3 nmol/l), and glutamate higher (47+/-3 vs. 36+/-4 mumol/l) in TM than in CON (all P<0.05), whereas muscle blood flow was similar in groups. Furthermore, muscle pyruvate was higher (180+/-15 vs. 135+/-12 mumol/l) and lactate higher (4.4+/-0.3 vs. 3.1+/-0.3 mmol/l) in TM than in CON (P<0.001). In response to exercise, VAS and glutamate increased in both TM and CON (all P<0.05). In TM only, lactate and pyruvate increased significantly (P<0.02), whereas blood flow increased to similar levels in both groups. During the initial 20 min recovery period, blood flow remained increased in TM (P<0.005) whereas it decreased to baseline levels in CON. In conclusion, patients with chronic work-related TM have increased levels of muscle 5-HT and glutamate that were correlated to pain intensity (r=0.55, P<0.001) and PPT (r=-0.47, P<0.001), respectively. In addition, TM was associated with increased anaerobic metabolism, whereas a normal rise in blood flow was seen with exercise. These findings indicate that peripheral nociceptive processes are active in work-related TM.
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| 33. |
- Rotter Sopasakis, Victoria, 1972, et al.
(författare)
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Short-term infusion of interleukin-6 does not induce insulin resistance in vivo or impair insulin signalling in rats
- 2004
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 47:11, s. 1879-87
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Tidskriftsartikel (refereegranskat)abstract
- AIMS/HYPOTHESIS: Interleukin-6 has been implicated in the insulin resistance associated with obesity and impaired glucose tolerance. Previous studies in vitro have shown that IL-6 rapidly (1-2 h) impairs cellular insulin signalling and action through an increased expression of suppressor of cytokine signalling (SOCS)-3. In the present study, IL-6 or saline was infused in rats that were simultaneously in a state of hyperinsulinaemia. Muscle, liver and adipose tissue were excised after 2 h to examine potential effects on insulin signalling or gene expression. METHODS: The rats were infused with IL-6 or saline during a euglycaemic-hyperinsulinaemic clamp and the glucose infusion rate was measured after 90 to 120 min. Signal transducer and activator of transcription (STAT)3 phosphorylation and insulin-stimulated tyrosine phosphorylation of the insulin receptors and IRS were measured with immunoblotting and gene expression through real-time PCR. RESULTS: No inhibitory effect of IL-6 on insulin-stimulated whole-body glucose uptake was seen in spite of high circulating levels of IL-6 (0.85+/-0.08 nmol/l). Tyrosine phosphorylation of the insulin receptors and IRS was also unchanged in the liver, skeletal muscles and adipose tissue. However, tyrosine phosphorylation of STAT3 was increased in all tissues, showing that IL-6 signalling was activated. IL-6 mRNA tended to increase, while GLUT4, peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1) and adiponectin gene expression were unchanged. CONCLUSIONS/INTERPRETATION: Infusion of IL-6 for 120 min in rats during euglycaemic-hyperinsulinaemic conditions did not alter the effect of insulin on whole-body glucose homeostasis, plasma adiponectin levels or insulin signalling in target tissues. Thus, the acute effects of IL-6, associated with SOCS-3 induction, do not lead to whole-body insulin resistance. These data further underscore the importance of the chronic, and potentially tissue-specific effects of IL-6 on insulin signalling and action.
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