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- Larsson, Nirina, et al.
(författare)
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Airway inflammatory responses to diesel exhaust in allergic rhinitics
- 2013
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Ingår i: Inhalation Toxicology. - : Informa UK Limited. - 0895-8378 .- 1091-7691. ; 25:3, s. 160-167
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Larsson, Nirina, 1979-
(författare)
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Allergic airway disease : studies on diesel exhaust exposures, oxylipins and antioxidants
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 4. |
- Larsson, Nirina, et al.
(författare)
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Are Swedish swingers a risk group for sexually transmitted infections?
- 2021
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Ingår i: International Journal of STD and AIDS (London). - : Sage Publications. - 0956-4624 .- 1758-1052. ; 32:5, s. 427-434
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate whether Swedish swingers constitute a risk group for sexually transmitted infections (STIs). Two swinger clubs were invited to participate. At swinger meetings, members were offered an STI sampling kit and a questionnaire. Samples were analyzed for Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, and Trichomonas vaginalis using a multiplex real-time polymerase chain reaction assay. In total, 235 swingers participated (118 women and 117 men). Urogenital C. trachomatis prevalence was 1.7%. Urogenital M. genitalium prevalence was 7.6% for women and 4.3% for men. No one tested positive for N. gonorrhoeae or T. vaginalis. For women, the mean number of unprotected temporary sex partners within the last 12 months was four men (range 0–35) and three women (range 0–50). Among men, the mean number of unprotected temporary sex partners within the last 12 months was five women (range 0–50) and 0 men (range 0–10). During vaginal sex, 46.6% women and 38.5% men always used protection with a temporary sex partner. Swedish swingers did not seem to have an increased prevalence of STIs. However, there was high-risk sexual behavior with unprotected sex and multiple sex partners, thereby making them a vulnerable group for acquiring STIs.
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| 5. |
- Larsson, Nirina, et al.
(författare)
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Are Urogenital Symptoms Caused by Sexually Transmitted Infections and Colonizing Bacteria?
- 2021
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Ingår i: Journal of Lower Genital Tract Disease. - : Wolters Kluwer. - 1089-2591 .- 1526-0976. ; 25:3, s. 232-235
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This study aimed to investigate the prevalence of sexually transmitted infections (STIs) and colonizing bacteria in relation to urogenital symptoms.Materials and Methods: In this cross-sectional study, patients visiting the STI clinic at Umeå University Hospital were asked for symptoms and condom use. Samples from 759 patients (465 male and 294 female) were analyzed for 4 STIs (Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium) and 3 colonizing bacteria (Mycoplasma hominis, Ureaplasma parvum, and Ureaplasma urealyticum).Results: Chlamydia trachomatis prevalence was 11% among women and 9.5% among men. Neisseria gonorrhoeae prevalence was 0.7% among women and 0.9% among men. Mycoplasma genitalium was found in 11% and 5.6% of women and men, respectively. Asymptomatic men and women had similar distribution patterns of microorganisms as those with urogenital symptoms, with the exceptions of Neisseria gonorrhoeae- and Mycoplasma genitalium-infected men who declared symptoms more frequently. Of 158 men with urogenital symptoms, 55% were test-negative. Of 129 women with urogenital symptoms, 12% were test-negative.Conclusions: This study reveals a complex picture, where a large number of multi-positive tests made it complicated to correlate urogenital symptoms with microorganisms. A high number of test-negative but symptomatic patients indicate a need of searching for additional pathogens.
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| 6. |
- Larsson, Nirina, et al.
(författare)
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Identification of vitamin C transporters in the human airways : a cross-sectional in vivo study
- 2015
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Ingår i: BMJ Open. - : BMJ. - 2044-6055. ; 5:4
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 7. |
- Larsson, Nirina, et al.
(författare)
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Lipid mediator profiles differ between lung compartments in asthmatic and healthy humans
- 2014
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Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 43:2, s. 453-463
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 8. |
- Larsson, Nirina, et al.
(författare)
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Self-compassion, perfectionism, impostor phenomenon, stress and anxiety in patients with localized provoked vulvodynia
- 2023
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Ingår i: Journal of Psychosomatic Obstetrics and Gynaecology. - : Taylor & Francis. - 0167-482X .- 1743-8942. ; 44:1
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Tidskriftsartikel (refereegranskat)abstract
- Studies have shown that psychological distress has a role in the symptomology of localized provoked vulvodynia. Therefore, psychosocial support has been presented as a valuable part of the treatment. However, little is known about which psychological variables that coincide with localized provoked vulvodynia. The purpose of this study was to identify qualities of psychological distress in patients with localized provoked vulvodynia. Patients with localized provoked vulvodynia were consecutively recruited to participate in this cross-sectional questionnaire-based study. Participants completed a self-report questionnaire measuring perfectionism, impostor phenomenon, self-compassion, anxiety and perceived stress. A sample of 30 patients were included. Questionnaire results suggestive of perfectionism was seen in 63%, impostor phenomenon in 80%, low self-compassion in 27%, anxiety in 43% and perceived stress in 23% of the participants. The level of self-compassion was higher in patients in a committed relationship. The investigated qualities appear to be more common in patients with localized provoked vulvodynia than in comparable groups. Impostor phenomenon and perfectionism were particularly common, with more than half of the study population scoring above the cutoff for clinical significance. This motivates research to investigate if interventions targeting impostor phenomenon and perfectionism, may aid in the treatment of localized provoked vulvodynia.
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| 9. |
- Larsson, Nirina, et al.
(författare)
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Seroprevalence of sexually transmitted infections over 44 years : a cross-sectional study in Sweden
- 2024
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Ingår i: International Journal of STD and AIDS (London). - : Sage Publications. - 0956-4624 .- 1758-1052.
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Tidskriftsartikel (refereegranskat)abstract
- Background: Sexually transmitted infections (STIs) may cause substantial individual suffering and a large economic burden for society. This study examined the seroprevalence of Chlamydia trachomatis, Mycoplasma genitalium, herpes simplex virus (HSV) types 1 and 2, and several human papillomaviruses (HPV) in the Swedish population over time.Methods: The study population consisted of 30-year-old women attending maternity care, and 50 year-old men and women attending health check-ups, from 1975 to 2018. Antibody status was determined by multiplex serology and quantified using median reporter fluorescence intensity (MFI).Results: A total of 891 samples were analysed (519 from 30-year-old women, 186 from 50 year-old women and 186 from 50 year-old men). Of these, 41.5% showed seropositivity for Chlamydia trachomatis, 16.7% for Mycoplasma genitalium, 70.5% for HSV-1, 14.9% for HSV-2, 13.2% for high-risk HPV, and 8.3% for low-risk HPV. Seropositivity for Mycoplasma genitalium, HSV-1 and especially Chlamydia trachomatis decreased over time.Conclusions: There was a decrease over time in Chlamydia trachomatis seroprevalence, probably due to contact tracing, testing and early treatment; this might also have affected Mycoplasma genitalium seroprevalence. Despite the reduction, seroprevalences are still high, so continued and new efforts to reduce STI incidence are essential.
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