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Larsson, Nirina
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Publications (9 of 9) Show all publications
Andersson, N., Preuss, I., Boman, J. & Nylander, E. (2019). Chlamydia Infection Among Digital Daters and Nondigital Daters. Journal of Lower Genital Tract Disease, 23(3), 230-234
Open this publication in new window or tab >>Chlamydia Infection Among Digital Daters and Nondigital Daters
2019 (English)In: Journal of Lower Genital Tract Disease, ISSN 1089-2591, E-ISSN 1526-0976, Vol. 23, no 3, p. 230-234Article in journal (Refereed) Published
Abstract [en]

Objectives: The aim of the study was to investigate whether the use of dating apps is a risk factor for acquiring Chlamydia trachomatis (CT) infections.

Methods: Patients attending the drop-in facility at the STI clinic at Umea University Hospital between April 2016 and November 2017 were asked to fill in a survey about their sexual preferences and behaviors, including dating app use.

Results: Of 943 participants, 80 (8.5%) received a CT diagnosis (34 women and 46 men). Dating app users did not seem to have an increased risk of CT infection. Having 3 or more sex partners within the last year was a risk factor for CT only among those not using a dating app. Alcohol use before sex and unprotected sex with a new partner were risk factors for CT infection in the univariate but not in the multivariate analysis.

Conclusions: Dating app users did not seem to have an increased risk of acquiring CT and for dating app users the seemingly well-established risk factor of having many partners was not valid.

Place, publisher, year, edition, pages
Lippincott Williams & Wilkins, 2019
Keywords
Chlamydia trachomatis, risk factor, survey, sexual behavior, dating apps
National Category
Infectious Medicine
Identifiers
urn:nbn:se:umu:diva-161830 (URN)10.1097/LGT.0000000000000483 (DOI)000474336000010 ()31233434 (PubMedID)
Available from: 2019-08-12 Created: 2019-08-12 Last updated: 2019-08-12Bibliographically approved
Andersson, N., Carré, H., Janlert, U., Boman, J. & Nylander, E. (2018). Gender differences in the well-being of patients diagnosed with Chlamydia trachomatis: a cross-sectional study. Sexually Transmitted Infections, 94(6), 401-405
Open this publication in new window or tab >>Gender differences in the well-being of patients diagnosed with Chlamydia trachomatis: a cross-sectional study
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2018 (English)In: Sexually Transmitted Infections, ISSN 1368-4973, E-ISSN 1472-3263, Vol. 94, no 6, p. 401-405Article in journal (Refereed) Published
Abstract [en]

Objectives: We aimed to investigate how an infection with Chlamydia trachomatis (CT) influenced patients' well-being and whether there were differences due to gender, age or relationship status, in an effort to strengthen preventive measures and provide better healthcare for patients with CT.

Methods: Patients diagnosed with CT in the county of Västerbotten, Sweden, were asked to fill out a questionnaire about their feelings, thoughts and actions after CT diagnosis. The patients were also asked to fill in the validated questionnaires Hospital Anxiety and Depression Scale and Alcohol Use Disorder Identification Test. Between February 2015 and January 2017, 128 patients (74 women and 54 men) were included in the study.

Results: After being diagnosed with CT, men were generally less worried than women (P<0.001). Women worried more about not being able to have children (P<0.001) and about having other STIs (P=0.001) than men did. Men felt less angry (P=0.001), less bad (P<0.001), less dirty (P<0.001) and less embarrassed (P=0.011) than women did. Nineteen per cent of men and 48% of women reported symptoms of anxiety. The majority of both men (60%) and women (72%) had a risk consumption of alcohol.

Conclusion: Women and men reacted differently when diagnosed with CT. Women worried more about complications and more often blamed themselves for being infected. Being aware of these gender differences may be important when planning preventive measures and during counselling of CT-infected patients. Persons working with patients with CT must also be aware of the high frequency of harmful alcohol consumption among their patients.

Place, publisher, year, edition, pages
BMJ Publishing Group Ltd, 2018
Keywords
attitudes, chlamydia infection, chlamydia trachomatis, gender, sexual health
National Category
Public Health, Global Health, Social Medicine and Epidemiology Dermatology and Venereal Diseases
Identifiers
urn:nbn:se:umu:diva-150585 (URN)10.1136/sextrans-2017-053229 (DOI)000443606300006 ()29306870 (PubMedID)
Available from: 2018-08-13 Created: 2018-08-13 Last updated: 2018-11-01Bibliographically approved
Andersson, N., Boman, J. & Nylander, E. (2017). Rectal chlamydia - should screening be recommended in women?. International Journal of STD and AIDS (London), 28(5), 476-479
Open this publication in new window or tab >>Rectal chlamydia - should screening be recommended in women?
2017 (English)In: International Journal of STD and AIDS (London), ISSN 0956-4624, E-ISSN 1758-1052, Vol. 28, no 5, p. 476-479Article in journal (Refereed) Published
Abstract [en]

Chlamydia trachomatis is the most common bacterial sexually transmitted infection in Europe and has large impacts on patients' physical and emotional health. Unidentified asymptomatic rectal Chlamydia trachomatis could be a partial explanation for the high Chlamydia trachomatis prevalence. In this study, we evaluated rectal Chlamydia trachomatis testing in relation to symptoms and sexual habits in women and men who have sex with men. Rectal Chlamydia trachomatis prevalence was 9.1% in women and 0.9% in men who have sex with men. None of the patients reported any rectal symptoms; 59.0% of the women with a rectal Chlamydia trachomatis infection denied anal intercourse and 18.8% did not have a urogenital infection; 9.4% did neither have a urogenital infection nor reported anal sex. We suggest that rectal sampling should be considered in women visiting sexually transmitted infection clinics regardless of rectal symptoms and irrespective of anal intercourse, since our data suggest that several cases of rectal Chlamydia trachomatis otherwise would be missed, thus enabling further disease transmission.

Keywords
Chlamydia trachomatis, screening
National Category
Dermatology and Venereal Diseases
Identifiers
urn:nbn:se:umu:diva-133731 (URN)10.1177/0956462416653510 (DOI)000395743800006 ()27235696 (PubMedID)
Available from: 2017-05-05 Created: 2017-05-05 Last updated: 2018-06-09Bibliographically approved
Larsson, N., Rankin, G. D., Bicer, E. M., Roos-Engstrand, E., Pourazar, J., Blomberg, A., . . . Behndig, A. F. (2015). Identification of vitamin C transporters in the human airways: a cross-sectional in vivo study. BMJ Open, 5(4), Article ID e006979.
Open this publication in new window or tab >>Identification of vitamin C transporters in the human airways: a cross-sectional in vivo study
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2015 (English)In: BMJ Open, ISSN 2044-6055, E-ISSN 2044-6055, Vol. 5, no 4, article id e006979Article in journal (Refereed) Published
Abstract [en]

Objectives: Vitamin C is an important low-molecular weight antioxidant at the air-lung interface. Despite its critical role as a sacrificial antioxidant, little is known about its transport into the respiratory tract lining fluid (RTLF), or the underlying airway epithelial cells. While several vitamin C transporters have been identified, such as sodium-ascorbate cotransporters (SVCT1/2) and glucose transporters (GLUTs), the latter transporting dehydroascorbate, knowledge of their protein distribution within the human lung is limited, in the case of GLUTs or unknown for SVCTs.

Setting and participants: Protein expression of vitamin C transporters (SVCT1/2 and GLUT1-4) was examined by immunohistochemistry in endobronchial biopsies, and by FACS in airway leucocytes from lavage fluid, obtained from 32 volunteers; 16 healthy and 16 mild asthmatic subjects. In addition, antioxidant concentrations were determined in RTLF. The study was performed at one Swedish centre.

Primary and secondary outcome measures: The primary outcome measure was to establish the location of vitamin C transporters in the human airways. As secondary outcome measures, RTLF vitamin C concentration was measured and related to transporter expression, as well as bronchial epithelial inflammatory and goblet cells numbers.

Results: Positive staining was identified for SVCT1 and 2 in the vascular endothelium. SVCT2 and GLUT2 were present in the apical bronchial epithelium, where SVCT2 staining was predominately localised to goblet cells and inversely related to RTLF vitamin C concentrations.

Conclusions: This experimental study is the first to demonstrate protein expression of GLUT2 and SVCT2 in the human bronchial epithelium. A negative correlation between SVCT2-positive goblet cells and bronchial RTLF vitamin C concentrations suggests a possible role for goblet cells in regulating the extracellular vitamin C pool.

National Category
Respiratory Medicine and Allergy
Identifiers
urn:nbn:se:umu:diva-106157 (URN)10.1136/bmjopen-2014-006979 (DOI)000354705000048 ()25854967 (PubMedID)
Available from: 2015-07-10 Created: 2015-07-09 Last updated: 2018-06-07Bibliographically approved
Larsson, N., Lundström, S., Pinto, R., Rankin, G., Karimpour, M., Blomberg, A., . . . Nording, M. (2014). Lipid mediator profiles differ between lung compartments in asthmatic and healthy humans. European Respiratory Journal, 43(2), 453-463
Open this publication in new window or tab >>Lipid mediator profiles differ between lung compartments in asthmatic and healthy humans
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2014 (English)In: European Respiratory Journal, ISSN 0903-1936, E-ISSN 1399-3003, Vol. 43, no 2, p. 453-463Article in journal (Refereed) Published
Abstract [en]

Oxylipins are oxidised fatty acids that can exert lipid mediator functions in inflammation, and several oxylipins derived from arachidonic acid are linked to asthma. This study quantified oxylipin profiles in different regions of the lung to obtain a broad-scale characterisation of the allergic asthmatic inflammation in relation to healthy individuals. Bronchoalveolar lavage fluid (BALF), bronchial wash fluid and endobronchial mucosal biopsies were collected from 16 healthy and 16 mildly allergic asthmatic individuals. Inflammatory cell counts, immunohistochemical staining and oxylipin profiling were performed. Univariate and multivariate statistics were employed to evaluate compartment-dependent and diagnosis-dependent oxylipin profiles in relation to other measured parameters. Multivariate modelling showed significantly different bronchial wash fluid and BALF oxylipin profiles in both groups ((RY)-Y-2[cum]=0.822 and Q(2)[cum]=0.759). Total oxylipin concentrations and five individual oxylipins, primarily from the lipoxygenase (LOX) pathway of arachidonic and linoleic acid, were elevated in bronchial wash fluid from asthmatics compared to that from healthy controls, supported by immunohistochemical staining of 15-LOX-1 in the bronchial epithelium. No difference between the groups was found among BALF oxylipins. In conclusion, bronchial wash fluid and BALF contain distinct oxylipin profiles, which may have ramifications for the study of respiratory diseases. Specific protocols for sampling proximal and distal airways separately should be employed for lipid mediator studies.

Keywords
airway inflammation, asthma, bronchoalveolar lavage, bronchial wash, lung compartments, oxylipin profiles
National Category
Respiratory Medicine and Allergy
Research subject
Lung Medicine
Identifiers
urn:nbn:se:umu:diva-83487 (URN)10.1183/09031936.00209412 (DOI)000330824500018 ()
Note

Included in thesis in manuscript form

Available from: 2013-11-27 Created: 2013-11-27 Last updated: 2018-06-08Bibliographically approved
Larsson, N., Brown, J., Stenfors, N., Wilson, S., Mudway, I. S., Pourazar, J. & Behndig, A. F. (2013). Airway inflammatory responses to diesel exhaust in allergic rhinitics. Inhalation Toxicology, 25(3), 160-167
Open this publication in new window or tab >>Airway inflammatory responses to diesel exhaust in allergic rhinitics
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2013 (English)In: Inhalation Toxicology, ISSN 0895-8378, E-ISSN 1091-7691, Vol. 25, no 3, p. 160-167Article in journal (Refereed) Published
Abstract [en]

Context: Proximity to traffic, particularly to diesel-powered vehicles, has been associated with inducing and enhancing allergies. To investigate the basis for this association, we performed controlled exposures of allergic rhinitics to diesel exhaust (DE) at a dose known to be pro-inflammatory in healthy individuals.

Objective: We hypothesized that diesel-exhaust exposure would augment lower airway inflammation in allergic rhinitics.

Materials and methods: Fourteen allergic rhinitics were exposed in a double-blinded, randomized trial to DE (100 mu g/m(3) PM10) and filtered air for 2 h on separate occasions. Bronchoscopy with endobronchial mucosal biopsies and airway lavage was performed 18 h post-exposure, and inflammatory markers were assessed.

Results: No evidence of neutrophilic airway inflammation was observed post-diesel, however, a small increase in myeloperoxidase was found in bronchoalveolar lavage (p = 0.032). We found no increases in allergic inflammatory cells. Reduced mast cell immunoreactivity for tryptase was observed in the epithelium (p = 0.013) parallel to a small decrease in bronchial wash stem cell factor (p = 0.033). Discussion and conclusion: DE, at a dose previously shown to cause neutrophilic inflammation in healthy individuals, induced no neutrophilic inflammation in the lower airways of allergic rhinitics, consistent with previous reports in asthmatics. Although there was no increase in allergic inflammatory cell numbers, the reduction in tryptase in the epithelium may indicate mast cell degranulation. However, this occurred in the absence of allergic symptoms. These data do not provide a simplistic explanation of the sensitivity in rhinitics to traffic-related air pollution. The role of mast cells requires further investigation.

Keywords
Allergy, diesel exhaust, susceptibility
National Category
Respiratory Medicine and Allergy
Identifiers
urn:nbn:se:umu:diva-67599 (URN)10.3109/08958378.2013.765932 (DOI)000315185300004 ()
Available from: 2013-06-03 Created: 2013-03-25 Last updated: 2018-06-08Bibliographically approved
Larsson, N. (2013). Allergic airway disease: studies on diesel exhaust exposures, oxylipins and antioxidants. (Doctoral dissertation). Umeå: Umeå Universitet
Open this publication in new window or tab >>Allergic airway disease: studies on diesel exhaust exposures, oxylipins and antioxidants
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Allergic airway disease, i.e. allergic rhinitis (AR) and asthma, is a common health problem. The prevalence is increasing in most countries of the world. Traffic-related air pollution has been found to induce and enhance allergic airway disease, but the underlying mechanisms are not known.

Oxylipins are fatty acid metabolites, of which several have been linked to asthmatic airway inflammation. Oxylipin profiles have previously been investigated in bronchoalveolar lavage (BAL), mainly reflecting the peripheral lung, but not in bronchial wash (BW), which better reflect the proximal airways.

The airway epithelium is covered by a respiratory tract lining fluid (RTLF) The RTLF contains antioxidants to protect from oxidative stress, which may be caused by exposure to air pollution. Previous studies have reported diminished levels of the antioxidant ascorbate (vitamin C) in the RTLF of patients with asthma. Little is known about the regulation of vitamin C in the lung.

The aim of this thesis was to investigate airway inflammatory responses to diesel exhaust exposure in patients with AR and allergic asthma; to evaluate oxylipin profiles in different regions of the lung in patients with allergic asthma; and to study the distribution of vitamin C transporters in the airways of patients with allergic asthma.

Diesel exhaust (PM10 100 μg/m3 for 2 h) induced a neutrophilic airway inflammation in healthy individuals evaluated 18 h after exposure. Patients with AR and asthma did not respond with an enhanced airway inflammation. However, a small increase in myeloperoxidase was found in BAL from patients with AR, as well as decreases in epithelial tryptase and BW stem cell factor. This indicates that other mechanisms than classical inflammation are responsible for the increased sensitivity to traffic-related air pollution in patients with allergic airway disease.

Oxylipin baseline profiles differed between peripheral and proximal airways in both allergic asthmatics and healthy individuals. Total oxylipin concentrations, and five individual oxylipins, primarily from the lipoxygenase (LOX) pathway, were elevated in BW from asthmatics compared to healthy controls, supported by immunohistochemical staining of 15-LOX-1 in the bronchial epithelium. This suggests that lung compartment-specific sampling should be considered in future studies.

Sodium dependent vitamin C transporter 2 (SVCT2) was, for the first time, found present in the human lung epithelium, localised mainly within goblet cells. A negative correlation between SVCT2+ goblet cells and vitamin C suggests that these cells may play a hitherto unknown function in ascorbate re-uptake and recycling at the air-lung interface.

Place, publisher, year, edition, pages
Umeå: Umeå Universitet, 2013. p. 60
Series
Umeå University medical dissertations, ISSN 0346-6612 ; 1609
Keywords
Asthma, allergic rhinits, diesel exhaust, airway inflammation, oxylipins, metabolomics, antioxidants, SVCT2, bronchoscopy
National Category
Respiratory Medicine and Allergy
Research subject
Lung Medicine
Identifiers
urn:nbn:se:umu:diva-83493 (URN)978-91-7459-749-3 (ISBN)
Public defence
2013-12-19, Hörsal B, 9 tr, Norrlands Universitetssjukhus, Umeå, 13:00 (Swedish)
Opponent
Supervisors
Available from: 2013-11-28 Created: 2013-11-27 Last updated: 2018-06-08Bibliographically approved
Behndig, A. F., Larsson, N., Brown, J. L., Stenfors, N., Helleday, R., Duggan, S. T., . . . Blomberg, A. (2011). Proinflammatory doses of diesel exhaust in healthy subjects fail to elicit equivalent or augmented airway inflammation in subjects with asthma. Thorax, 66(1), 12-19
Open this publication in new window or tab >>Proinflammatory doses of diesel exhaust in healthy subjects fail to elicit equivalent or augmented airway inflammation in subjects with asthma
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2011 (English)In: Thorax, ISSN 0040-6376, E-ISSN 1468-3296, Vol. 66, no 1, p. 12-19Article in journal (Refereed) Published
Abstract [en]

Exposure to diesel exhaust at concentrations consistent with roadside levels elicited an acute and active neutrophilic inflammation in the airways of healthy subjects. This response was absent in subjects with asthma, as was evidence supporting a worsening of allergic airway inflammation.

National Category
Respiratory Medicine and Allergy
Identifiers
urn:nbn:se:umu:diva-39566 (URN)10.1136/thx.2010.140053 (DOI)20837873 (PubMedID)
Available from: 2011-02-01 Created: 2011-02-01 Last updated: 2018-06-08Bibliographically approved
Larsson, N., Rankin, G., Bicer, M., Roos-Engstrand, E., Pourazar, J., Mudway, I. & Behndig, A.Vitamin C transporters in the airways of healthy and asthmatic humans.
Open this publication in new window or tab >>Vitamin C transporters in the airways of healthy and asthmatic humans
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(English)Manuscript (preprint) (Other academic)
National Category
Respiratory Medicine and Allergy
Research subject
Lung Medicine
Identifiers
urn:nbn:se:umu:diva-83488 (URN)
Available from: 2013-11-27 Created: 2013-11-27 Last updated: 2018-06-08Bibliographically approved
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