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- Bednarska, Olga, et al.
(författare)
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Neurotransmittor Concentration in Pregenual ACC in Stool Consistency Patient Subgroups With IBS
- 2014
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Konferensbidrag (refereegranskat)abstract
- IntroductionThe Anterior Cingulate Cortex (ACC) is a key region of the central autonomic brain network. Irritable Bowel Syndrome (IBS) is characterized abdominal pain and bowel habit disturbances. Autonomic dysregulation has been reported in IBS as well as altered ACC activation in pregenual ACC during visceral stimulation 1 2. Glutamate is the major excitatory and Gamma-aminobutyric acid (GABA) the major inhibitory neurotransmitter in the brain.Aim & MethodsWe aimed to measure neurotransmitter concentration in the pregenual ACC, in stool consistency subgroups with IBS by using quantitative neurotransmitter Magnetic Resonance Spectroscopy (qMRS)Seven patients with IBS-mixed (6 women) and five patients with IBS -diarrhea (4 women) according to Rome 3 were included. Mean age was 34.2 years (SD 5.3) with no significant difference between subgroups. Patients completed symptom severity score (IBS-SSS). Quantitative MRS was measured in a 3T MRI scanner. A water-suppressed MEGA-PRESS sequence (TR 2.0 s, TE 68 ms) was used with the editing pulses placed at 1.90 ppm (‘ON-dynamics’) and at 7.46 ppm (‘OFF-dynamics’) with a voxel (3x3x3 cm3) placed in the pACC. Each MEGA-PRESS measurement resulted in a sequence of 40 OFF- and ON-dynamics, where each was computed by 8 phase cycles. Directly after each water-suppressed MEGA-PRESS measurement, a shorter 2-dynamic unsuppressed water MEGA-PRESS measurement was performed within the same voxel, which was used to obtain the concentrations in physically well-defined units of [mM]. The GABA concentrations were computed by averaging the difference spectra obtained by subtracting each OFF-dynamic from subsequent ON-dynamic and using LCModel (Version 6.3) for the final quantification. The Glutamate concentrations were obtained by only averaging the OFF-dynamics, which were not affected by the editing pulses. Additionally, all dynamics were phase and frequency corrected prior to the averaging. For group comparison unpaired T-tests were used.ResultsPatients had moderate to severe symptoms with IBS-SSS of 367 (SD 79.7). There was no significant difference between IBS subgroups in terms of IBS-SSS. Mean pACC GABA concentration was 1.66 (SD 0.17) mM in IBS-M and 1.65 (SD 0.27) mM in IBS-D. There was no significant difference between groups (p=0.9). Mean pACC Glutamate concentration was 4.54 (0.35) mM in IBS-M and 5.13 (SD 0.64) mM in IBS-D. There was no significant difference between groups, although a trend with p=0.06 was observed.ConclusionFurther qMRS data have to be collected in IBS patients as well as healthy controls to evaluate if IBS subgroups demonstrate alterations in pACC glutamate and GABA concentrations
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- Berlin, Gösta, et al.
(författare)
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Effects of age, gender and menstrual cycle on platelet function assessed by impedance aggregometry
- 2019
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Ingår i: Platelets. - : TAYLOR & FRANCIS INC. - 0953-7104 .- 1369-1635. ; 30:4, s. 473-479
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Tidskriftsartikel (refereegranskat)abstract
- Platelets are needed to prevent or arrest bleeding and aggregate at the site of injury upon vascular damage. Platelets express receptors for estrogens which might affect the function of the platelets and their hemostatic ability. The aim was to identify possible differences in platelet function related to age, gender, and phases of the menstrual cycle by use of impedance aggregometry with Multiplate. In the first part of the study, platelet function was assessed in 60 healthy individuals (30 men and 30 women) in each of three age groups (20-25, 40-45, and 60-65 years). In the second part of the study, the platelet function was analyzed on four occasions during the menstrual cycle in women without oral contraceptives (OCs) (n = 17) and compared to 19 women on OCs and 18 men of similar age (20-40 years). For the women on OCs, aggregation was analyzed once during the tablet-free week and once late during the period with OCs. The men were sampled once. Women of younger age (amp;lt;45 years) had significantly higher agonist-induced aggregation response than both men and post-menopausal women (60-65 years). The agonist-induced aggregation response did not differ between phases of the menstrual cycle or OC use. The results suggest that estradiol and/or progesterone affect spontaneous aggregation since it was found to be lowest in the mid-luteal phase. Spontaneous aggregation was significantly lower in women on OCs than in both men and women without OCs. Our findings indicate that fertile age is associated with higher aggregation response capacity of the platelets, possibly to prevent excessive bleeding during menstruation, but this response capacity is not altered during the menstrual cycle or by use of OCs.
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- Konarska, Janina, 1986, et al.
(författare)
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319: Tree Health, Growth and Cooling Effects at Contrasting Urban Sites in Gothenburg, Sweden
- 2018
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Ingår i: 10th International Conference on Urban Climate/14th Symposium on the Urban Environment, New York, US, August 2018.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- One of the most important ecosystem services provided by urban trees is the mitigation of urban heat. However, this cooling effect may be compromised due to vulnerability of urban trees to harsh urban environment and ongoing climate change. In this project we aim to analyse the growth and health of urban tree species in Gothenburg, Sweden in response to different urban growing conditions, as well as the impact of heat and drought stress on tree cooling benefits through changes to shading effect and transpiration. Three species with different adaptation mechanisms to drought stress were selected: Aesculus hippocastanum, Tilia europaea and Quercus palustris. For each species, trees of the same age planted at adjacent paved and unpaved sites were chosen for the study. In 2017, measured traits included stomatal conductance and transpiration rates, pre-dawn and midday water potentials, chlorophyll content, and leaf area density. In 2018, additional microclimate and human thermal comfort measurements were added to assess the cooling benefits provided by trees. The summertime measurements in 2017 showed significant differences in multiple plant traits between contrasting sites for all species studied, with trees at paved sites showing reduced gas exchange, chlorophyll content and leaf area density compared to sites with a higher fraction of permeable surfaces. These differences were observed both on a hot summer day following a dry period, as well as on a cooler day following a wet period. A clear difference in water use dynamics between species with ”tolerant” (e.g. Q. palustris) and ”avoiding” (e.g. A. hippocastanum) mechanisms against drought stress were also observed. The results highlight the importance of proper planning and species selection in supporting the health and resilience of the urban forest as well as maximising its cooling benefits. The study will be continued in Melbourne, Australia with the focus on urban tree performance alongside water sensitive urban design (WSUD).
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