| 1. |
- Björnsdottir, Halla, et al.
(författare)
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Phenol-soluble Modulin α Peptide Toxins from aggressive Staphylococcus aureus induce rapid Formation of neutrophil extracellular Traps through a reactive Oxygen species-independent Pathway
- 2017
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Neutrophils have the ability to capture and kill microbes extracellularly through the formation of neutrophil extracellular traps (NETs). These are DNA and protein structures that neutrophils release extracellularly and are believed to function as a defense mechanism against microbes. The classic NET formation process, triggered by, e.g., bacteria, fungi, or by direct stimulation of protein kinase C through phorbol myristate acetate, is an active process that takes several hours and relies on the production of reactive oxygen species (ROS) that are further modified by myeloperoxidase (MPO). We show here that NET-like structures can also be formed by neutrophils after interaction with phenol-soluble modulin alpha (PSM alpha) that are cytotoxic membrane-disturbing peptides, secreted from community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). The PSMa-induced NETs contained the typical protein markers and were able to capture microbes. The PSMa-induced NET structures were disintegrated upon prolonged exposure to DNase-positive S. aureus but not on exposure to DNase-negative Candida albicans. Opposed to classic NETosis, PSMa-triggered NET formation occurred very rapidly, independently of ROS or MPO, and was also manifest at 4 degrees C. These data indicate that rapid NETs release may result from cytotoxic membrane disturbance by PSMa peptides, a process that may be of importance for CA-MRSA virulence.
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| 2. |
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| 3. |
- Chen, Yun, 1966, et al.
(författare)
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Hair glucocorticoid concentration, self-perceived stress and their associations with cardiometabolic risk markers in Swedish adolescents
- 2022
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Ingår i: Psychoneuroendocrinology. - : Elsevier BV. - 0306-4530. ; 146
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Tidskriftsartikel (refereegranskat)abstract
- Background: While hair cortisol is proposed as a biomarker for chronic stress and a possible mediator linking chronic stress and cardiovascular risk in adults, studies in adolescents are scarce. We explored the associations between self-perceived stress, hair cortisol (HairF) and cortisone (HairE), and cardiometabolic risk markers in adolescents. Further, we examined whether association between self-perceived stress and HairF may depend on the use of the coping strategies "shift-persist ". Methods: Participants were 7th grade pupils recruited to the STudy of Adolescence Resilience and Stress (STARS) and data from the baseline examinations were used. Adolescents (n = 1553, 26 % boys, Mage=13.6, SD = 0.4) completed questionnaires assessing perceived stress and coping strategies "shift-persist ", provided hair sample, and examined for cardiometabolic risk factors including waist circumference (WC), body mass index (BMI) z -score, blood pressure, and white blood cell counts (WBC). HairF and HairE were analysed using liquid chro-matography with tandem mass spectrometry. We conducted descriptive analyses (Student's t-test, Wilcoxon Signed Ranks test, Chi-square test) and linear regression analyses. Results: Perceived stress was not associated with HairF, neither had the use of coping strategies "shift-persist " any influence on this association. Both HairF and HairE were positively associated with BMI z-score (beta coefficients (8): 0.178 (p < 0.001) and 0.119 (p < 0.001) for boys; 0.123 (p < 0.001) and 0.089 (p < 0.01) for girls) and WC (8: 0.089 (p > 0.05) and 0.098 (p < 0.05) for boys; 0.103 (p < 0.01) and 0.076 (p < 0.05) for girls). Perceived stress was also positively associated with BMI z-score and WC. Perceived stress, but not HairF, remained asso-ciated with WC in boys (8 = 0.200, p < 0.001) in the models with HairF and perceived stress presented simultaneously. Modest association between HairE and WBC was found in boys (8 = 0.149, p < 0.01). Conclusions: The study supports the association between chronic stress and overweight/obesity in adolescents. Hair cortisol and self-perceived stress capture different aspects of how chronic stress is related to overweight/ obesity in adolescents.
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| 4. |
- Chen, Yun, 1966, et al.
(författare)
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Impact of COVID-19 pandemic on mental health and health behaviors in Swedish adolescents
- 2022
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Ingår i: Scandinavian Journal of Public Health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 50, s. 26-32
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Tidskriftsartikel (refereegranskat)abstract
- Aims: There is an urgent need to explore the impact of the COVID-19 pandemic on adolescent mental health and health behaviours. To date, there are no such studies on Swedish adolescents. As COVID-19 emerged in the middle of our ongoing 2-year follow-up examination of the Study of Adolescence Resilience and Stress, we had the unique opportunity to use the corona outbreak as a 'natural experiment' to study the impact of COVID-19 on 15-year-old adolescents in Sweden. Methods: Adolescents (baseline age 13.6 +/- 0.4 years) were recruited from schools in western Sweden (during the COVID-19 outbreak schools were kept open for those under 16 years of age). The COVID-19 pandemic reached Sweden on 31 January 2020. A total of 1316 adolescents answered the 2-year follow-up survey before (unexposed to COVID-19 pandemic, controls) and 584 after 1 February 2020 (COVID19-exposed). Data on stress, psychosomatic symptoms, happiness, relationships with parents and peers, school and health behaviours were collected. Results: Adolescents reported higher levels of stress and psychosomatic symptoms and lower levels of happiness at follow-up compared to baseline. These changes occurred to a similar extent in both the control and COVID-19-exposed groups. Likewise, the COVID-19-exposed group showed no deterioration in peer relations or relations with parents versus controls. We did not find any significant differences between groups regarding sleep duration and physical activity. Conclusions: Swedish adolescents exposed to COVID-19 during most of 2020 showed no differences in longitudinal changes in mental health, relationships with parents and peers, and health behaviours compared to those not exposed to COVID-19.
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| 5. |
- Dahlgren, Liselotte, et al.
(författare)
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Human papillomavirus is more common in base of tongue than in mobile tongue cancer and is a favorable prognostic factor in base of tongue cancer patients.
- 2004
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 112:6, s. 1015-9
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Tidskriftsartikel (refereegranskat)abstract
- The frequency of human papilloma virus (HPV) and its influence on clinical outcome was analyzed retrospectively in pre-treatment paraffin embedded biopsies from 110 patients with tongue cancer. The presence of HPV DNA was examined in 85 mobile tongue tumors and 25 base of tongue tumors by a polymerase chain reaction (PCR) with 2 general primer pairs, GP5+/6+ and CPI/IIG. When HPV-DNA was found, HPV-type specific primers and direct sequencing were used for HPV sub-type verification. Twelve of 110 (10.9%) samples were HPV-positive; 9 for HPV-16, 1 for HPV-33, 1 for HPV-35 and 1 could not be analyzed because of shortage of DNA. HPV was significantly more common in base of tongue tumors (10/25, 40.0%) compared to tumors of the mobile tongue (2/85, 2.3%). The influence of HPV on clinical outcome in mobile tongue cancer could not be studied, due to that HPV was present in too few cases. Of the 19 patients with base of tongue cancer that were included in the survival analysis, however, 7 patients with HPV-positive base of tongue cancer had a significantly favorable 5-year survival rate compared to the 12 HPV-negative patients. In conclusion, HPV is significantly more common in base of tongue cancer than in mobile tongue cancer, and has a positive impact on disease-specific survival in patients with base of tongue cancer.
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| 7. |
- Dahlstrand, Johan, et al.
(författare)
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Move for Your Heart, Break a Sweat for Your Mind: Providing Precision in Adolescent Health and Physical Activity Behaviour Pattern.
- 2023
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Ingår i: The Journal of adolescent health : official publication of the Society for Adolescent Medicine. - 1879-1972. ; 73:1, s. 29-36
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Tidskriftsartikel (refereegranskat)abstract
- Adolescent health benefits of different physical activity (PA) intensities, especially of lower intensities, are debated due to challenges in accelerometer data processing and analyses. Using a new accelerometer data processing method and multivariate pattern analysis, this study investigated the association of PA intensities with indicators of cardiovascular and mental health.Adolescents (n= 1,235, mean age 13.6years, 41% males) were examined for cardiovascular health: body mass index (BMI) z-score, waist circumference (WC), resting heart rate and blood pressure, white blood cell count (WBC), pulse wave velocity (PWV), and answered questionnaires assessing stress and psychosomatic symptoms. Sex, age, and socioeconomic status were confounders. Hip-worn accelerometer data were processed with 10Hz frequency extended method and a spectrum of 22 PA intensity categories was analyzed for association with health using partial least squares regression.Total explained variances for BMI z-score, WC, resting heart rate, stress, and psychosomatic symptoms were higher (3.3%-8.7%) compared to diastolic blood pressure, WBC, and PWV (0.9%-1.4%). We found positive associations of high-end moderate PA and vigorous PA with cardiovascular and mental health indicators. More sedentary time and lower level of light PA were associated with higher BMI z-score, WC, resting heart rate, diastolic blood pressure, WBC, and PWV, but not with mental health indicators. Very vigorous PA was negatively associated with resting heart rate, stress, and psychosomatic symptoms.In adolescents, PA of varying intensities were generally found to be positively associated with better cardiovascular health, but only higher intensity PA was associated with better mental health.
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| 8. |
- Dahlstrand, Johan, et al.
(författare)
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Reaching the Poor: Some Observations on Formal and Informal Credit in Haiti
- 2007
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Ingår i: Savings and Development. - : Giordano Dell'amore Foundation. - 0393-4551. ; 31:2, s. 113-130
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Tidskriftsartikel (refereegranskat)abstract
- The article traces the evolution of credit to the poor in Haiti, mainly from the 1950s to the present. Two phases may be distinguished. The first one, characterized on the one hand by the dominance of informal lenders and on the other by unsuccessful efforts sponsored by the government to reach the peasant majority, extends from the beginning of the 1950s until the end of the 1970s. This was a period of failure from the point of view of formal credit, with a number of institutions that lent little to the needy and which had to be closed down for financial reasons. The second period, from the beginning of the 1980s to the present time, has seen the evolution of a new institutional framework: that of organized micro credits, mainly in urban areas, beginning in the capital and gradually extending into provincial towns as well. This approach is much more promising than the old one, and possibly it can be extended ito rural areas as well.
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| 9. |
- Dahlstrand, Johan, et al.
(författare)
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The use of coping strategies “shift-persist” mediates associations between physical activity and mental health problems in adolescents: a cross-sectional study
- 2021
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Ingår i: BMC Public Health. - : Springer Science and Business Media LLC. - 1471-2458. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Self-perceived mental health problems among adolescents has had an upward trend. Concurrently, adolescents’ physical activity (PA) has been falling whilst sedentary time (SED) has increased. There is a lack of research using accelerometer measured PA and SED to study their relationships to perceived stress and psychosomatic symptoms, both frequently observed mental health problems among adolescents. Whether coping strategies is one of the mechanisms underlying such relationship is less clear. Methods: A total of 2283 13-year olds were enrolled in the baseline examination of the STARS (STudy of Adolescence Resilience and Stress) study in Western Sweden. Light-, moderate-, vigorous-intensity PA (LPA, MPA and VPA) and SED were measured using hip-worn ActiGraph GT3X+ accelerometer. A total of 1284 adolescents provided valid accelerometer data (at least 4 days with ≥10 h per day). PA and SED during school-time and leisure-time were analysed separately. Surveys were utilized to monitor perceived stress, psychosomatic symptoms and the use of coping strategies “shift-persist”. Logistic regression and mediation analyses were performed adjusting for gender, ethnicity, socioeconomic status and puberty development. Results: We observed that more time spent in PA was associated with less stress in adolescents. The associations were observed for LPA (Odds ratio for LPA per 60 min: 0.557 (95% CI 0.399–0.776), VPA (Odds ratio for VPA per 15 min: 0.688 (95% CI 0.588–0.806) and MVPA (Odds ratio for MVPA per 15 min: 0.795 (95%CI 0.718–0.879) during leisure time, but not during school time. Similar associations were observed between leisure time PA and psychosomatic symptoms. The associations remained statistically significant even after adjusting for the confounders. Further, our data showed that adolescents who engaged more time in PA during leisure time were more likely to adopt the coping strategies of “shift-persist”. Mediation analysis showed that the use of “shift-persist” mediated the associations between leisure time PA and stress/psychosomatic symptoms. Conclusions: Leisure time physical activity, irrespective of intensity, may facilitate successful coping with stress and stress-related mental health problems in adolescents. © 2021, The Author(s).
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| 10. |
- Dahlstrand Rudin, Agnes, et al.
(författare)
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Porphyromonas gingivalis Produce Neutrophil Specific Chemoattractants Including Short Chain Fatty Acids
- 2021
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Ingår i: Frontiers in cellular and infection microbiology. - : Frontiers Media SA. - 2235-2988. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Neutrophil migration from blood to tissue-residing microbes is governed by a series of chemoattractant gradients of both endogenous and microbial origin. Periodontal disease is characterized by neutrophil accumulation in the gingival pocket, recruited by the subgingival biofilm consisting mainly of gram-negative, anaerobic and proteolytic species such as Porphyromonas gingivalis. The fact that neutrophils are the dominating cell type in the gingival pocket suggests that neutrophil-specific chemoattractants are released by subgingival bacteria, but characterization of chemoattractants released by subgingival biofilm species remains incomplete. In the present study we characterized small (< 3 kDa) soluble chemoattractants released by growing P. gingivalis, and show that these are selective for neutrophils. Most neutrophil chemoattractant receptors are expressed also by mononuclear phagocytes, the free fatty acid receptor 2 (FFAR2) being an exception. In agreement with the selective neutrophil recruitment, the chemotactic activity found in P. gingivalis supernatants was mediated in part by a mixture of short chain fatty acids (SCFAs) that are recognized by FFAR2, and other leukocytes (including monocytes) did not respond to SCFA stimulation. Although SCFAs, produced by bacterial fermentation of dietary fiber in the gut, has previously been shown to utilize FFAR2, our data demonstrate that the pronounced proteolytic metabolism employed by P. gingivalis (and likely also other subgingival biofilm bacteria associated with periodontal diseases) may result in the generation of SCFAs that attract neutrophils to the gingival pocket. This finding highlights the interaction between SCFAs and FFAR2 in the context of P. gingivalis colonization during periodontal disease, but may also have implications for other inflammatory pathologies involving proteolytic bacteria.
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