| 1. |
- Mamontov, Eugen, 1955, et al.
(author)
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The minimal, phase-transition model for the cell-number maintenance by the hyperplasia-extended homeorhesis
- 2006
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In: Acta Biotheoretica. - : Springer Science and Business Media LLC. - 0001-5342 .- 1572-8358. ; 54:2, s. 61-101
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Journal article (peer-reviewed)abstract
- Oncogenic hyperplasia is the first and inevitable stage of formation of a (solid) tumor. This stage is also the core of many other proliferative diseases. The present work proposes the first minimal model that combines homeorhesis with oncogenic hyperplasia where the latter is regarded as a genotoxically activated homeorhetic dysfunction. This dysfunction is specified as the transitions of the fluid of cells from a fluid, homeorhetic state to a solid, hyperplastic-tumor state, and back. The key part of the model is a nonlinear reaction-diffusion equation (RDE) where the biochemical-reaction rate is generalized to the one in the well-known Schlögl physical theory of the non-equilibrium phase transitions. A rigorous analysis of the stability and qualitative aspects of the model, where possible, are presented in detail. This is related to the spatially homogeneous case, i.e. when the above RDE is reduced to a nonlinear ordinary differential equation. The mentioned genotoxic activation is treated as a prevention of the quiescent G0-stage of the cell cycle implemented with the threshold mechanism that employs the critical concentration of the cellular fluid and the nonquiescent-cell-duplication time. The continuous tumor morphogeny is described by a time-space-dependent cellular-fluid concentration. There are no sharp boundaries (i.e. no concentration jumps exist) between the domains of the homeorhesis- and tumor-cell populations. No presumption on the shape of a tumor is used. To estimate a tumor in specific quantities, the model provides the time-dependent tumor locus, volume, and boundary that also points out the tumor shape and size. The above features are indispensable in the quantitative development of antiproliferative drugs or therapies and strategies to prevent oncogenic hyperplasia in cancer and other proliferative diseases. The work proposes an analytical-numerical method for solving the aforementioned RDE. A few topics for future research are suggested.
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| 2. |
- Sukhovey, Yurij G., et al.
(author)
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Functional Conjugation of the Different Regulatory Responses to the Stress Stimuli in Healthy Human Subjects
- 2016
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In: Open Journal of Applied Sciences. - : Scientific Research Publishing, Inc.. - 2165-3917 .- 2165-3925. ; 6, s. 489-500
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Journal article (peer-reviewed)abstract
- Present article discusses the physiological mechanisms of the state employees adaptation duringactive training in temporary groups. It is suggested that adaptive mechanisms to adverse effectsmay be studied basing on the concept of functional isomorphism of the psychic and immune systems.Adaptive mechanisms were studied through the monitoring of the stress factors’ impact upon thelaw enforcement officers when training outside the places of permanent deployment. The specificpurpose of present study was to evaluate the physiological indicators of the psychic, immune andendocrine systems dynamics at different stages of adaptation of the live organism to a stressfulsituation, hoping to get better insight into possible relations between psychic and immune domains.Through monitoring of the dynamics of the endocrine and immune responses to the psychic stimuli,it was possible to correlate the stages of the stress onset to the phases of specific immune reactions.Strong correlations between the parameters characterizing activation of the psychic and immuneresponses support the hypothesis of the presence of “strong cooperation” between psychic andimmune domains. It supports earlier hypothesis that we are monitoring
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| 3. |
- Landberg, Rikard, 1981, et al.
(author)
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Avenanthramides as lipoxygenase inhibitors
- 2020
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In: Heliyon. - : Elsevier BV. - 2405-8440. ; 6:6
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Journal article (peer-reviewed)abstract
- Avenanthramides (AVAs) present in oats are amides of anthranilic and cinnamic acids. AVAs are potent antioxidants and have anti-inflammatory properties. There are various potential mechanisms for their anti-inflammatory effects, including inhibition of lipoxygenases (LOX), which catalyse oxygenation of polyunsaturated fatty acids into potent signal molecules involved in inflammatory processes. In this study, AVAs were screened for LOX inhibition in vitro and structure-activity relationships were examined. Twelve different AVAs at 0.6 mM were tested as LOX inhibitors. The corresponding free cinnamic acids, the AVA analogue Tranilast® and the known LOX inhibitor trans-resveratrol were included for comparison. It was found that AVAs comprising caffeic or sinapic acid exhibited significant lipoxygenase inhibition (60–90%) (P < 0.05), whereas low or no inhibition was observed with AVAs containing p-coumaric or ferulic acid. No difference in inhibition was seen on comparing AVAs with their free corresponding cinnamic acids, which implies that the anthranilic acid part of the avenanthramide molecule does not affect inhibition. Trans-resveratrol showed inhibition, whereas no inhibition was seen for Tranilast® at the concentrations used in this study. This study suggests that aventahtramides comprising caffeic acid or sinapic acid partly exert their antioxidant and anti-inflammatory effects via lipoxygenase inhibition.
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| 4. |
- Holmström, Pontus, et al.
(author)
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Test–retest reliability of splenic volume assessment by ultrasonography
- 2022
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In: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 12:1
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Journal article (peer-reviewed)abstract
- While MRI and CT are the gold standards for assessments of splenic size in clinical settings, ultrasonography is particularly suited due to its portability, cost efficiency and easy utilization. However, ultrasonography is associated with subjective assessment, potentially resulting in increased variation. We used a test–retest design aiming to determine the reliability of splenic measurements assessed by ultrasonography during apnea. In addition, we compared reliability between different equations for volume calculations: Koga, Prolate ellipsoid and Pilström. Twelve healthy participants (6 women) performed two tests separated by 15 min, comprising a maximal voluntary apnea in a seated position. Splenic dimensions were measured via ultrasonography for 5 min before and immediately following apnea. Resting splenic volume displayed high test–retest reliability between tests (Pilström: 157 ± 39 mL vs 156 ± 34 mL, p = .651, ICC = .970, p < .001, CV = 2.98 ± 0.1%; Prolate ellipsoid: 154 ± 37 mL vs 144 ± 43 mL, p = .122, ICC = .942, p < .001, CV = 5.47 ± 0.3%; Koga: 142 ± 37 mL vs 140 ± 59 mL, p = .845, ICC = .859, p < .001, CV = 9.72 ± 1.4%). Apnea-induced volumes displayed similar reliability (127 ± 29 mL vs 129 ± 28 mL, p = .359, ICC = .967, p < .001, CV = 3.14 ± 3.1%). Reliability was also high between equations (Pilström vs Prolate ellipsoid: ICC = .818, p < .001, CV = 7.33 ± 0.3%, bias = − 3.1 mL, LoA = − 46.9 to 40.7 mL; Pilström vs Koga: ICC = .618, p < .01, CV = 11.83 ± 1.1%, bias = − 14.8 mL, LoA = − 76.9 to 47.3 mL). We conclude that splenic ultrasonographic measurements have practical applications during laboratory and field-based research as a reliable method detecting splenic volume change consistently between repeated tests. The Pilström equation displayed similar reliability compared to the prolate ellipsoid formula and slightly higher compared to the Koga formula and may be particularly useful to account for individual differences in splenic dimensions.
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| 5. |
- Schulte, Stefanie, et al.
(author)
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Serum Concentrations of S100B are not Affected by Cycling to Exhaustion With or Without Vibration
- 2011
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In: Journal of Human Kinetics. - : Termedia Sp. z.o.o.. - 1640-5544 .- 1899-7562. ; 30:1, s. 67-78
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Journal article (peer-reviewed)abstract
- The calcium-binding protein S100B is produced primarily by astrocytes and exerts concentration-dependentparacrine and autocrine effects on neurons and glia. The numerous findings of a correlation between S100B andtraumatic brain injury (TBI) have resulted in the employment of this protein as a clinical biomarker for such injury.Our present aim was to determine whether cycling with (V) or without (NV) vibration alters serum concentrations ofS100B. Twelve healthy, male non-smokers (age: 25.3±1.6 yrs, body mass: 74.2±5.9 kg, body height: 181.0±3.7 cm,VO2peak: 56.9±5.1 ml·min-1·kg-1(means ± SD)) completed in random order two separate trials to exhaustion on avibrating bicycle (amplitude 4 mm and frequency 20 Hz) connected to an ergometer. The initial workload of 100 W waselevated by 50 W every 5 min and the mean maximal period of exercise was 25:27±1:30 min. The S100B in venousblood taken at rest, immediately after the test, and 30, 60 and 240 min post-exercise exhibited no significant differences(p>0.05), suggesting that cycling with and without vibration does not influence this parameter.
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| 6. |
- Furmark, Tomas, et al.
(author)
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A link between serotonin-related gene polymorphisms, amygdala activity, and placebo-induced relief from social anxiety
- 2008
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In: Journal of Neuroscience. - 0270-6474 .- 1529-2401. ; 28:49, s. 13066-74
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Journal article (peer-reviewed)abstract
- Placebo may yield beneficial effects that are indistinguishable from those of active medication, but the factors underlying proneness to respond to placebo are widely unknown. Here, we used functional neuroimaging to examine neural correlates of anxiety reduction resulting from sustained placebo treatment under randomized double-blind conditions, in patients with social anxiety disorder. Brain activity was assessed during a stressful public speaking task by means of positron emission tomography before and after an 8 week treatment period. Patients were genotyped with respect to the serotonin transporter-linked polymorphic region (5-HTTLPR) and the G-703T polymorphism in the tryptophan hydroxylase-2 (TPH2) gene promoter. Results showed that placebo response was accompanied by reduced stress-related activity in the amygdala, a brain region crucial for emotional processing. However, attenuated amygdala activity was demonstrable only in subjects who were homozygous for the long allele of the 5-HTTLPR or the G variant of the TPH2 G-703T polymorphism, and not in carriers of short or T alleles. Moreover, the TPH2 polymorphism was a significant predictor of clinical placebo response, homozygosity for the G allele being associated with greater improvement in anxiety symptoms. Path analysis supported that the genetic effect on symptomatic improvement with placebo is mediated by its effect on amygdala activity. Hence, our study shows, for the first time, evidence of a link between genetically controlled serotonergic modulation of amygdala activity and placebo-induced anxiety relief.
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| 7. |
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| 8. |
- Bergman, Olle, 1978, et al.
(author)
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Association between amygdala reactivity and a dopamine transporter gene polymorphism.
- 2014
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In: Translational psychiatry. - : Springer Science and Business Media LLC. - 2158-3188. ; 4
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Journal article (peer-reviewed)abstract
- Essential for detection of relevant external stimuli and for fear processing, the amygdala is under modulatory influence of dopamine (DA). The DA transporter (DAT) is of fundamental importance for the regulation of DA transmission by mediating reuptake inactivation of extracellular DA. This study examined if a common functional variable number tandem repeat polymorphism in the 3' untranslated region of the DAT gene (SLC6A3) influences amygdala function during the processing of aversive emotional stimuli. Amygdala reactivity was examined by comparing regional cerebral blood flow, measured with positron emission tomography and [(15)O]water, during exposure to angry and neutral faces, respectively, in a Swedish sample comprising 32 patients with social anxiety disorder and 17 healthy volunteers. In a separate US sample, comprising 85 healthy volunteers studied with blood oxygen level-dependent functional magnetic resonance imaging, amygdala reactivity was assessed by comparing the activity during exposure to threatening faces and neutral geometric shapes, respectively. In both the Swedish and the US sample, 9-repeat carriers displayed higher amygdala reactivity than 10-repeat homozygotes. The results suggest that this polymorphism contributes to individual variability in amygdala reactivity.
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| 9. |
- Essner, Ann, et al.
(author)
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Comparison of Polar® RS800CX heart rate monitor and electrocardiogram for measuring inter-beat intervals in healthy dogs
- 2015
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In: Physiology and Behavior. - : Elsevier. - 0031-9384 .- 1873-507X. ; 138:January, s. 247-253
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Journal article (peer-reviewed)abstract
- The aim of the present study was to assess the criterion validity, relative reliability and level of agreement ofPolar® RS800CX heart rate monitor measuring inter-beat intervals (IBIs), compared to simultaneously recordedelectrocardiogram (ECG) in dogs.Methods: Five continuous minutes of simultaneously recorded IBIs from Polar® RS800CX and Cardiostore ECG in11 adult healthy dogs maintaining standing position were analyzed. Polar® data was statistically compared toECG data to assess for systematic differences between the methods. Three different methods for handling missingIBI data were used. Criterion validities were calculated by intraclass correlation coefficients (ICCs) and corresponding95% confidence intervals (CIs). Relative reliabilities and levels of agreement were calculated by ICCsand the Bland and Altman analysis for repeated measurements per subject.Results: Correlation coefficients between IBI data from ECG and Polar® RS800CX varied between 0.73 and 0.84depending on how missing values were handled. Polar® was over- and underestimating IBI data compared toECG. The mean difference in log transformed (base10) IBI data was 0.8%, and 93.2% of the values were withinthe limits of agreement. Internally excluding three subjects presenting IBI series containing more than 5% erroneousIBIs resulted in ICCs between 0.97 and 0.99. Bland and Altman analysis (n = 8) showed mean differencewas 1.8 ms, and 98.5% of the IBI values were plotted inside limits of agreement.Conclusion: This study showed that Polar® systematically biased recorded IBI series and that it was fundamentalto detect measurement errors. For Polar® RS800CX heart rate monitor to be used interchangeably to ECG, byshowing excellent criterion validity and reliable IBI measures in group and individual samples, only less than5% of artifacts could be accepted.
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| 10. |
- Heikkila, K., et al.
(author)
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Job strain and the risk of severe asthma exacerbations : a meta-analysis of individual-participant data from 100 000 European men and women
- 2014
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In: Allergy. European Journal of Allergy and Clinical Immunology. - : Wiley. - 0105-4538 .- 1398-9995. ; 69:6, s. 775-783
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Journal article (peer-reviewed)abstract
- BackgroundMany patients and healthcare professionals believe that work-related psychosocial stress, such as job strain, can make asthma worse, but this is not corroborated by empirical evidence. We investigated the associations between job strain and the incidence of severe asthma exacerbations in working-age European men and women. MethodsWe analysed individual-level data, collected between 1985 and 2010, from 102 175 working-age men and women in 11 prospective European studies. Job strain (a combination of high demands and low control at work) was self-reported at baseline. Incident severe asthma exacerbations were ascertained from national hospitalization and death registries. Associations between job strain and asthma exacerbations were modelled using Cox regression and the study-specific findings combined using random-effects meta-analyses. ResultsDuring a median follow-up of 10years, 1 109 individuals experienced a severe asthma exacerbation (430 with asthma as the primary diagnostic code). In the age- and sex-adjusted analyses, job strain was associated with an increased risk of severe asthma exacerbations defined using the primary diagnostic code (hazard ratio, HR: 1.27, 95% confidence interval, CI: 1.00, 1.61). This association attenuated towards the null after adjustment for potential confounders (HR: 1.22, 95% CI: 0.96, 1.55). No association was observed in the analyses with asthma defined using any diagnostic code (HR: 1.01, 95% CI: 0.86, 1.19). ConclusionsOur findings suggest that job strain is probably not an important risk factor for severe asthma exacerbations leading to hospitalization or death.
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