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| 2. |
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| 3. |
- Albépart-Ottesen, Chantal, 1952-
(författare)
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L'auto-reformulation corrective: une stratégie dans la production orale de FLE
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this dissertation is to observe how Swedish learners of French monitor their speech output when confronted with a linguistic problem. The study is based on empirical data consisting of recorded interviews and tasks made with first year university students.L1 speech production is often interrupted by hesitations revealed through a variety of phenomena ranging from silent pauses to comments. Most of these interruptions are caused by the action of a control system, a “monitor” which checks our speech internally while it is produced or after the production has reached the articulation level. Speech is checked against an internal model of lexical and grammatical correctness. If the demands of the monitor are not met, a reparation may take place so that the speaker’s production eventually reaches the expected level of correctness.In the same way, the speech of L2 learners is controlled during and after production. The pattern of work of the monitor is much the same as for the L1, but the reparation is not necessarily conducted in a similar way because the learner’s internal grammar and lexicon are not complete and cannot be consulted as quickly as the L1 lexicon and grammar. L2 learners rely on a certain amount of acquired knowledge but they also need to be given time to refer to learned rules and patterns since the retrieval of these has not yet been made automatic.In this study, we observe the speech production of Swedish students learning French during the first semester of their academic studies. The recasts students make when trying to reach a correct solution to a linguistic problem are in focus. We can see a step-by-step process through which the speakers elaborates their production by putting forward hypotheses, each one usually containing a small modification, and try to reach an acceptable solution. In some cases we can see that the speaker might choose to focus on the communicative aspects instead of focusing on the formal correctness of the speech. On the background of L1 and L2 acquisition theories, this study focuses on two areas of difficulty for the Swedish learner: the production of –ment adverbs and the production of conjugated verbs.
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| 4. |
- Badiali, Luca, et al.
(författare)
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Adhesion GPCRs are widely expressed throughout the subsections of the gastrointestinal tract
- 2012
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Ingår i: BMC Gastroenterology. - 1471-230X. ; 12, s. 134-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: G protein-coupled receptors (GPCRs) represent one of the largest families of transmembrane receptors and the most common drug target. The Adhesion subfamily is the second largest one of GPCRs and its several members are known to mediate neural development and immune system functioning through cell-cell and cell-matrix interactions. The distribution of these receptors has not been characterized in detail in the gastrointestinal (GI) tract. Here we present the first comprehensive anatomical profiling of mRNA expression of all 30 Adhesion GPCRs in the rat GI tract divided into twelve subsegments.METHODS: Using RT-qPCR, we studied the expression of Adhesion GPCRs in the esophagus, the corpus and antrum of the stomach, the proximal and distal parts of the duodenum, ileum, jejunum and colon, and the cecum.RESULTS: We found that twenty-one Adhesion GPCRs (70%) had a widespread (expressed in five or more segments) or ubiquitous (expressed in eleven or more segments) distribution, seven (23%) were restricted to a few segments of the GI tract and two were not expressed in any segment. Most notably, almost all Group III members were ubiquitously expressed, while the restricted expression was characteristic for the majority of group VII members, hinting at more specific/localized roles for some of these receptors.CONCLUSIONS: Overall, the distribution of Adhesion GPCRs points to their important role in GI tract functioning and defines them as a potentially crucial target for pharmacological interventions.
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| 5. |
- Bengtsson, Magnus Wilhelm, 1977-
(författare)
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Effects of Orexins, Guanylins and Feeding on Duodenal Bicarbonate Secretion and Enterocyte Intracellular Signaling
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The duodenal epithelium secretes bicarbonate ions and this is regarded as the primary defence mechanism against the acid discharged from the stomach. For an efficient protection, the duodenum must also function as a sensory organ identifying luminal factors. Enteroendocrine cells are well-established intestinal “taste” cells that express signaling peptides such as orexins and guanylins. Luminal factors affect the release of these peptides, which may modulate the activity of nearby epithelial and neural cells.The present thesis considers the effects of orexins and guanylins on duodenal bicarbonate secretion. The duodenal secretory response to the peptides was examined in anaesthetised rats in situ and the effects of orexin-A on intracellular calcium signaling by human as well as rat duodenal enterocytes were studied in vitro.Orexin-A, guanylin and uroguanylin were all stimulants of bicarbonate secretion. The stimulatory effect of orexin-A was inhibited by the OX1-receptor selective antagonist SB-334867. The muscarinic antagonist atropine on the other hand, did not affect the orexin-A-induced secretion, excluding involvement of muscarinic receptors. Orexin-A induced calcium signaling in isolated duodenocytes suggesting a direct effect at these cells. Interestingly, orexin-induced secretion and calcium signaling as well as mucosal orexin-receptor mRNA and OX1-receptor protein levels were all substantially downregulated in overnight fasted rats compared with animals with continuous access to food. Further, secretion induced by Orexin-A was shown to be dependent on an extended period of glucose priming.The uroguanylin-induced bicarbonate secretion was reduced by atropine suggesting involvement of muscarinic receptors. The melatonin receptor antagonist luzindole attenuated the secretory response to intra-arterially administered guanylins but had no effect on secretion when the guanylins were given luminally. In conclusion, the results suggest that orexin-A as well as guanylins may participate in the regulation of duodenal bicarbonate secretion. Further, the duodenal orexin system is dependent on the feeding status of the animals.
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| 6. |
- Brändström, Sven, 1952-, et al.
(författare)
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Further development of the Temperament and Character Inventory
- 2001
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Ingår i: Psychological Reports. - 0033-2941 .- 1558-691X. ; 93, s. 995-1002
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Tidskriftsartikel (refereegranskat)abstract
- The Temperament and Character Inventory is an internationally used personality questionnaire based on Cloninger’s psychobiological theory of personality. Given some limitations of Version 9 a revised version was developed. The structural equivalence of the two versions was demonstrated from a cross-cultural perspective with 309 and 173 healthy volunteers from Sweden and Germany, respectively, who completed both versions in one session. In testing for the replicability of the factors across both samples as well as across both versions, an orthogonal Procrustes rotation method was used. The reliability coefficients for the revision were higher than the former version for both samples. The factor structures of the inventory remain highly equivalent across cultures and across versions. The results indicate a cross-cultural transferability of the Temperament and Character dimensions of the inventory. The stability and the validity of the 7-factor model of personality, as suggested by Cloninger, are supported. The Temperament and Character Inventory-Revised represents an important and useful method for the assessment of personality.
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| 7. |
- Brändström, Sven, 1952-, et al.
(författare)
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Further development of the temperament and character inventory
- 2003
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Ingår i: Psychological Reports. - 0033-2941 .- 1558-691X. ; 93:3 II, s. 995-1002
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Tidskriftsartikel (refereegranskat)abstract
- The Temperament and Character Inventory is an internationally used personality questionnaire based on Cloninger's psychobiological theory of personality. Given some limitations of Version 9 a revised version was developed. The structural equivalence of the two versions was demonstrated from a cross-cultural perspective with 309 and 173 healthy volunteers from Sweden and Germany, respectively, who completed both versions in one session. In testing for the replicability of the factors across both samples as well as across both versions, an orthogonal Procrustes rotation method was used. The reliability coefficients for the revision were higher than the former version for both samples. The factor structures of the inventory remain highly equivalent across cultures and across versions. The results indicate a cross-cultural transferability of the Temperament and Character dimensions of the inventory. The stability and the validity of the 7-factor model of personality, as suggested by Cloninger, are supported. The Temperament and Character Inventory-Revised represents an important and useful method for the assessment of personality.
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| 8. |
- Brändström, Sven, 1952-
(författare)
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Personality and its complexity : An investigation of the Swedish version of the Temperament and Character Inventory
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In former days the descriptions of personality were based on typologies, reflecting the view that people do not change over time and so have a stable, life-long personality type. Later on exclusive categories were created, but during recent times the understanding of personality has changed due to more dimensional and dynamic thinking.Cloninger’s personality theory integrates concepts and research findings from neuroanatomy, neurophysiology of behavior and learning, and from developmental, social and clinical psychology. It is postulated that the behavioural systems of temperament and character are related to two major neural systems for the adaptation of experiences on various levels. The continuous interaction between temperament and character affects the personality development in both directions; temperament impacts upon character and vice versa during life.The development of the TCI was founded on the development of the biosocial theory of personality, which in turn stimulated the further development of the theory. Unfortunately this theory-based approach is not commonly used in the development of personality measurements. The development of a personality questionnaire on the basis of the theory must be viewed as a significant challenge, and this prompted my interest in dealing with and learning more about this personality assessment method.The objectives of this thesis were a critical evaluation of Cloninger’s theory; a test of its applicability in psychiatric science; and an attempt to contribute to its development.The main findings of our investigations can be described as follows:The adaptation of the Swedish version of the Temperament and Character Inventory (TCI) was successful and the seven factor structure of Cloninger’s biopsychological theory of personality theory was mainly confirmed by the Swedish normative data and by cross-cultural comparisons between data from Germany, Sweden and the U.S.A.The results concerning internal consistency and factor structure further underline that the adult version of the TCI is unsuitable for use in adolescents before age of 17 years. For the adolescents the junior TCI is recommended.Furthermore temperament dimensions seem to be more stable over time compared to the character dimensions. The gender and age differences found suggest that both have to be taken into account in research and clinical application.The results from our studies suggested that the Temperament and Character Inventory (TCI) has to be evaluated as a useful tool within the process of validation of diagnosis of a Personality Disorder (PD), especially in clinical practice where it is often difficult to recognise all a patient’s personality disturbances during a short time. Use of the TCI is likely to improve understanding, classification, and subsequently the interpretations in clinical settings.
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| 9. |
- Brändström, Sven, 1952-, et al.
(författare)
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Swedish normative data on personality using the Temperament and Character Inventory
- 1998
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Ingår i: Comprehensive Psychiatry. - 0010-440X .- 1532-8384. ; 39:3, s. 122-128
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Tidskriftsartikel (refereegranskat)abstract
- The Temperament and Character Inventory (TCI) is a self-report personality questionnaire based on Cloninger's psychobiological model of personality, which accounts for both normal and abnormal variation in the two major components of personality, temperament and character. Normative data for the Swedish TCI based on a representative Swedish sample of 1,300 adults are presented, and the psychometric properties of the questionnaire are discussed. The structure of the Swedish version replicates the American version well for the means, distribution of scores, and relationships within the between scales and subscales. Further, the Swedish inventory had a reliable factor structure and test-retest performance. The results of this study confirm the theory of temperament and character as a seven-factor model of personality.
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| 10. |
- Brändström, Sven, 1952-, et al.
(författare)
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The Swedish Version of the Temperament and Character Inventory (TCI) : A Cross-Validation of Age and Gender Influences
- 2008
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Ingår i: European Journal of Psychological Assessment. - : Hogrefe Publishing Group. - 1015-5759 .- 2151-2426. ; 24:1, s. 14-21
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Tidskriftsartikel (refereegranskat)abstract
- In order to establish new norms of the Swedish version of the Temperament and Character Inventory (TCI), data from 2,209 Swedish individuals (age between 13 and 80) was analyzed. The second aim was to evaluate the impact of age and gender on the questionnaire scores. The third aim was to investigate whether the TCI can be meaningfully applied to adolescents in personality assessment as a basis for further research and clinical studies. Age and gender showed independent effects on personality dimensions, which implies that age and gender specific norms have to be established for the TCI. Furthermore, the results in terms of inconsistencies in the correlational and factorial structure, as well as low internal consistency scores in the younger age groups, suggest that the adult version of the TCI should not be applied below the age of 17; for these age groups we recommend the use of the junior TCI (JTCI). The inventory is under further development and several items are in need of revision in order to create less complicated formulations, enabling an improvement in the psychometrics.
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| 11. |
- Brändström, Sven, et al.
(författare)
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The Swedish version of the Temperament and Character Inventory (TCI)
- 2008
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Ingår i: European Journal of Psychological Assessment. - Göttingen : Hogrefe & Huber Publishers. - 1015-5759 .- 2151-2426. ; 24:1, s. 14-21
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Tidskriftsartikel (refereegranskat)abstract
- In order to establish new norms of the Swedish version of the Temperament and Character Inventory (TCI), data from 2,209 Swedish individuals (age between 13 and 80) was analyzed. The second aim was to evaluate the impact of age and gender on the questionnaire scores. The third aim was to investigate whether the TO can be meaningfully applied to adolescents in personality assessment as a basis for further research and clinical studies. Age and gender showed independent effects on personality dimensions, which implies that age and gender specific norms have to be established for the TCI. Furthermore, the results in terms of inconsistencies in the correlational and factorial structure, as well as low internal consistency scores in the younger age groups, suggest that the adult version of the TCI should not be applied below the age of 17; for these age groups we recommend the use of the junior TCI (JTCI). The inventory is under further development and several items are in need of revision in order to create less complicated formulations, enabling an improvement in the psychometrics.
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| 12. |
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| 13. |
- Carlsson, Anna, et al.
(författare)
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Identification of a susceptibility locus for migraine with and without aura on 6p12.2-p21.1
- 2002
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Ingår i: Neurology. - : Lippincott Williams & Wilkins. - 0028-3878 .- 1526-632X. ; 59:11, s. 1804-1807
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Tidskriftsartikel (refereegranskat)abstract
- Migraine is the most common type of chronic episodic headache. To find novel susceptibility genes for familial migraine with and without aura, a genomewide screen was performed in a large family from northern Sweden. Evidence of linkage was obtained on chromosome 6p12.2-p21.1, with a maximum two-point lod score of 5.41 for marker D6S452. The patients with migraine shared a common haplotype of 10 Mb between markers D6S1650 and D6S1960.
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| 14. |
- Cedernaes, Jonathan, et al.
(författare)
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Comprehensive analysis of localization of 78 solute carrier genes throughout the subsections of the rat gastrointestinal tract
- 2011
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 411:4, s. 702-707
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Tidskriftsartikel (refereegranskat)abstract
- Solute carriers (SLCs), the second largest super-family of membrane proteins in the human genome, transport amino acids, sugars, fatty acids, inorganic ions, essential metals and drugs over membranes. To date no study has provided a comprehensive analysis of SLC localization along the entire GI tract. The aim of the present study was to provide a comprehensive, segment-specific description of the localization of SLC genes along the rat Cl tract by employing bioinformatics and molecular biology methods. The Unigene database was screened for rat SLC entries in the intestinal tissue. Using qPCR we measured expression of the annotated genes in the Cl tract divided into the following segments: the esophagus, the corpus and the antrum of the stomach, the proximal and distal parts of the duodenum, ileum, jejunum and colon, and the cecum. Our Unigene-derived gene pool was expanded with data from in-house tissue panels and a literature search. We found 44 out of 78 (56%) of gut SLC transcripts to be expressed in all Cl tract segments, whereas the majority of remaining SLCs were detected in more than five segments. SLCs are predominantly expressed in gut regions with absorptive functions although expression was also found in segments unrelated to absorption. The proximal jejunum had the highest number of differentially expressed SLCs. In conclusion, SLCs are a crucial molecular component of the Cl tract, with many of them expressed along the entire GI tract. This work presents the first overall road map of localization of transporter genes in the Cl tract.
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| 15. |
- Dahlgren, David, et al.
(författare)
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Hypotonicity-Induced Increase in Duodenal Mucosal Permeability Is Regulated by Cholinergic Receptors in Rats
- 2023
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Ingår i: Digestive Diseases and Sciences. - : Springer. - 0163-2116 .- 1573-2568. ; 68:5, s. 1815-1823
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe role of cholinergic receptors in the regulation of duodenal mucosal permeability in vivo is currently not fully described.AimsTo elucidate the impact of nicotinic and muscarinic acetylcholine receptor signaling in response to luminal hypotonicity (50 mM NaCl) in the proximal small intestine of rat.MethodsThe effect on duodenal blood-to-lumen clearance of 51Cr-EDTA (i.e., mucosal permeability) and motility was studied in the absence and presence of nicotinic and muscarinic receptor agonists and antagonists, a sodium channel blocker (tetrodotoxin), and after bilateral cervical vagotomy.ResultsRats with duodenal contractions responded to luminal hypotonicity by substantial increase in intestinal permeability. This response was absent in animals given a non-selective nicotinic receptor antagonist (mecamylamine) or agonist (epibatidine). Pretreatment with tetrodotoxin reduced the increase in mucosal permeability in response to luminal hypotonicity. Further, the non-selective muscarinic receptor antagonist (atropine) and agonist (bethanechol) reduced the hypotonicity-induced increase in mucosal permeability, while vagotomy was without an effect, suggesting that local enteric reflexes dominate. Finally, neither stimulating nor blocking the α7-nicotinic receptor had any significant effects on duodenal permeability in response to luminal hypotonicity, suggesting that this receptor is not involved in regulation of duodenal permeability. The effect of the different drugs on mucosal permeability was similar to the effect observed for duodenal motility.ConclusionsA complex enteric intramural excitatory neural reflex involving both nicotinic and muscarinic receptor subtypes mediates an increase in mucosal permeability induced by luminal hypotonicity.
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| 16. |
- Engström, Christer, et al.
(författare)
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Bipolar disorder I. Temperament and character
- 2004
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Ingår i: Journal of Affective Disorders. - Amsterdam : Elsevier. - 0165-0327 .- 1573-2517. ; 82:1, s. 131-134
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Tidskriftsartikel (refereegranskat)abstract
- Background: The nature of the relationship between personality and bipolar affective disorders is an important but unanswered question. Methods: We have studied personality in bipolar patients by using the Temperament and Character Inventory (TCI). TCI were administered to 100 euthymic bipolar patients and 100 controls from the normal population.Results: Bipolar patients were significantly higher in harm avoidance (HA) and lower in reward dependence (RD), self-directedness (SD), and cooperativeness (CO) than controls. Bipolar patients are more fatigable, less sentimental, more independent, less purposeful, less resourceful, less empathic, less helpful, less pure-hearted, and have less impulse control than controls. Bipolar II patients are more impulsive, more fatigable, less resourceful, and have less impulse control than bipolar I patients.Limitations: Our results are limited to euthymic bipolar patients and cannot be generalized to affective disorders.Conclusions: Even when clinically euthymic on lithium maintenance, bipolar patients continue to have a characteristic cognitive deficit. This is in agreement with cognitive theories about cognitive deficits in depression that are regarded as important vulnerability factors in mood disorders.
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| 17. |
- Engström, C, et al.
(författare)
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Bipolar disorder. II : Personality and age of onset
- 2003
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Ingår i: Bipolar Disorders. - : Wiley. - 1398-5647 .- 1399-5618. ; 5:5, s. 340-348
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim of this study was to examine whether personality i.e. temperament and character interacts with age of onset in bipolar disorder. Methods: Bipolar patients were recruited among in- and outpatients from lithium dispensaries of northern Sweden. Patients were diagnosed according to DSM-IV criteria for bipolar disorder type I and II. Temperament and Character Inventory (TCI) was used for measuring personality. TCI was administered to 100 lithium treated bipolar patients and 100 controls. Results: Treatment response was significantly lower (p = 0.005) in patients with early onset compared with late onset. Family history (p = 0.013) and suicide attempts (p = 0.001) were also significantly more common in patients with early onset. Further, patients with early onset were significantly higher (p = 0.045) in the temperament factor harm avoidance (HA) than patients with late onset, but the difference was weak. Patients with early onset had more fear of uncertainty (HA2, P = 0.022) and were more shy (HA3, p = 0.030). Bipolar I patients showed similar results as those in the total bipolar group (I and II), with significantly higher HA (p = 0.019, moderate difference), HA2 (p = 0.015) and HA3 (p = 0.043) in patients with early onset compared with late onset. Bipolar II patients showed no differences between early and late age of onset but the groups are small and the results are therefore uncertain. Conclusions: Early age of onset in bipolar disorder was correlated to an increase in severity, family history, poorer treatment response and poorer prognosis. Early onset was also correlated to personality.
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| 18. |
- Engström, Christer, et al.
(författare)
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Bipolar disorder. III : harm avoidance a risk factor for suicide attempts
- 2004
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Ingår i: Bipolar Disorders. - Copenhagen : Blackwell Munksgaard. - 1398-5647 .- 1399-5618. ; 6:2, s. 130-138
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim of the study was to examine whether personality, i.e. temperament and character influence suicide attempts in bipolar patients.Methods: Bipolar patients were recruited from lithium dispensaries. Temperament and character inventory (TCI) was administered to 100 euthymic bipolar patients and 100 controls.Results: Age of onset was significantly lower in patients with suicide attempts in the total bipolar group (I and II) and bipolar I patients compared with patients without suicide attempts. Bipolar (I and II) and bipolar I patients with suicide attempts were significantly higher in harm avoidance (HA) and reward dependence compared with patients without suicide attempts. Patients (I and II) with suicide attempts had significantly more anticipatory worry, fatigability and asthenia than patients without suicide attempts. Bipolar I patients with suicide attempts had significantly more fatigability and asthenia and were more dependent than patients without suicide attempts. HA was lowest in patients with no suicide attempts and no family history of suicide, higher in patients with family history of suicide or patients with suicide attempts, and significantly highest in patients with suicide attempts and family history of suicide. Patients with suicide attempts and family history of suicide had more anticipatory worry, fatigability and asthenia. Bipolar disorder was significantly correlated to HA and suicide attempts to HA and PS. Family history of suicide and gender were significantly correlated to suicide attempts.Conclusions: Age of onset, HA, PS, gender and family history of suicide had a moderate to very strong effect on suicide attempts in bipolar patients.
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| 19. |
- Engström, Christer, et al.
(författare)
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Relationship between prophylactic effect of lithium therapy and family history of affective disorders
- 1997
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Ingår i: Biological Psychiatry. - 0006-3223 .- 1873-2402. ; 42:6, s. 425-433
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Tidskriftsartikel (refereegranskat)abstract
- Lithium therapy response and age of onset (AOO) were studied in 98 patients with bipolar affective disorder (BPAD) who were divided into subgroups depending on type of family history of affective disorders. The highest (33.0 years) and lowest (25.5 years) age of onset were found in nonfamilial patients and in familial patients with a first-degree relative of BPAD, respectively. Nonfamilial patients showed the best response to lithium. There were 0.9 episodes/year off lithium compared to 0.3 episodes/year on lithium (an 88% decrease). A poorer response (a 71% decrease; a reduction from 1.39 episodes per year off lithium to 0.65 on lithium) was found in familial patients with a first-degree relative of BPAD. Differences in serum lithium values between the groups could not explain the observed differences. Thus, familial patients showed a more severe manifestation of the disease with an earlier AOO and a lower prophylactic effect of lithium.
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| 20. |
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| 21. |
- Göransson, Viktoria, et al.
(författare)
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Renomedullary and intestinal hyaluronan content during body water excess : a study in rats and gerbils
- 2002
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Ingår i: Journal of Physiology. - : Wiley. - 0022-3751 .- 1469-7793. ; 542:1, s. 315-22
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Tidskriftsartikel (refereegranskat)abstract
- Our previous studies in rats have suggested a role for renomedullary hyaluronan (HA) in water homeostasis. The gerbil is known for its unique ability to conserve water. In the present study renal papillary and intestinal HA were compared between groups of anaesthetized gerbils and rats before and after up to 6 h of I.V. water loading. Baseline papillary HA in gerbils was only 37 % of that in the rat. Water loading in rats increased the papillary HA content. Elevation was maximal (+27 %, P < 0.05) after 2 h of water loading and then declined to control levels after 6 h of water loading (+3 %, n.s.). In contrast, the gerbil responded with a decreased papillary HA content during water loading. The depression was maximal after 2 h (-49 %, P < 0.05) and was still 41 % below the control values after 6 h (P < 0.05). The urine flow rate increased rapidly in the rat and its maximum, 21 times above the control level (P < 0.05), occurred at the HA peak, i.e. after 2 h of water loading while in the gerbil, the urine flow rate increased slowly and slightly and was only six times above control values after 6 h of water loading (P < 0.05). The HA content along the intestine was similar in the two species: lowest in the duodenum and jejunum and highest in the distal colon. To conclude, in the rat, the elevation of papillary interstitial HA during acute water loading would counteract water reabsorption by changing the physico-chemical characteristics of the interstitial matrix favouring rapid water diuresis. This would work as a complement to the powerful regulation by ADH. The gerbil has a diametrically different regulation of papillary HA turnover during water loading. The decreased papillary HA level during water loading and the slow and small diuretic response may represent a genetic difference in adaptation to enhance the ability to conserve water in an arid environment.
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| 22. |
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| 23. |
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| 24. |
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| 25. |
- Jansson, Kjell, 1956-, et al.
(författare)
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The value of repeated echocardiographic evaluation in patients with idiopathic dilated cardiomyopathy during treatment with metoprolol or captopril
- 2000
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Ingår i: Scandinavian Cardiovascular Journal. - 1401-7431 .- 1651-2006. ; 34:3, s. 293-300
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Tidskriftsartikel (refereegranskat)abstract
- Serial echocardiographic investigations were carried out on patients with idiopathic dilated cardiomyopathy, to evaluate treatment effects on left ventricular (LV) performance during therapy with either metoprolol or captopril. Thirty-two patients (23 males and 9 females) with mild to moderate symptoms of heart failure (NYHA II-III) and a mean age of 49 years were included in the investigation. The patients were investigated with Doppler echocardiography before treatment, after 3 and 6 months of treatment (either metoprolol or captopril) and 1 month after withdrawal of treatment. Intra- and inter-investigator reproducibility was acceptable, with a coefficient of variation of less than 5% for LV dimensions. A reduction in LV dimensions was seen in both treatment groups. In the metoprolol group there was also an increase in LV stroke volume and fractional shortening. The non-invasive data were in accordance with invasive measurements of stroke volume and LV filling pressure. In patients with idiopathic dilated cardiomyopathy and mild to moderate symptoms of heart failure, echocardiography seemed to be sufficiently reproducible to be used for determination of treatment effects in a longitudinal heart failure study. Both metoprolol and captopril were well tolerated and had favourable effects on LV performance.
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| 26. |
- Josefsson, Ann, 1958-, et al.
(författare)
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Temperament and character in women with postpartum depression
- 2007
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Ingår i: Archives of Women's Mental Health. - : Springer Science and Business Media LLC. - 1434-1816 .- 1435-1102. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate whether women with postpartum depression differ in personality traits from healthy postpartum women, healthy controls from the normal Swedish population and non-postpartum women with major depression. Methods: Forty-five women with postpartum depression were compared with 62 healthy postpartum women, 62 age-matched, healthy, non-postpartum women from a normal sample and 74 non-postpartum women with major depression from a clinical sample. The edinburgh postnatal depression scale was used in order to screen for postpartum depression. A clinical diagnostic interview was done including a rating with the Montgomery-Asberg depression rating scale. Personality i.e. temperament and character was measured by the temperament and character inventory. Results: Harm avoidance (HA) was higher (p < 0.001) and self-directedness (SD) scored lower (p < 0.001) in women with postpartum depression compared to healthy postpartum women. These differences were the most important differences between these two groups. Women with postpartum depression scored lower (p = 0.001) in cooperativeness (CO) and higher (p = 0.019) in self-transcendence (ST) compared to healthy postpartum women. Women with postpartum depression scored overall similar to women with major depression. Conclusion: High HA and low SD can be seen as vulnerability factors for developing a depression and especially in a stressful situation as childbirth. © 2006 Springer-Verlag.
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| 27. |
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| 28. |
- Lexne, Erik
(författare)
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Psychiatric aspects on acute abdominal pain
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Psychiatric comorbidity is estimated to occur in up to 40% of all patients with somatic disorders, and it can have an influence on patient morbidity and mortality. Approximately 20% of patients who seek care for abdominal pain receive the diagnosis nonspecific abdominal pain, and later develop chronic abdominal pain. This condition and other abdominal conditions without organic explanation are sometimes called diseases of gut-braininteraction, and psychosocial factors (personality, psychiatric conditions, etc.) have been suggested to play an important role. Organic dyspepsia (which in this thesis is limited to pepticulcer, gastritis and gastro-esophageal reflux disease, or GERD) has previously been reported to be associated with personality traits and psychiatric conditions. Despite these known associations, few studies have specifically investigated psychiatric comorbidity in patients with acute abdominal conditions.The aim of this thesis is to investigate the prevalence of psychiatric comorbidity in patients with acute abdominal pain conditions in the emergency setting and to evaluate the possible longterm psychiatric problems of these patients.Methods: Consecutive patients with who came to emergency care with acute abdominal pain conditions were divided into three diagnostic groups: acid-dependent organic dyspepsia (pepticulcer, gastritis and GERD), specific abdominal diagnoses, and non-specific abdominal pain.These groups were evaluated for personality traits, psychiatric symptoms, and self-rated health.A follow-up study explored prescription of antidepressant and anxiolytic (anti-anxiety) medications in this patients 10–15 years after the initial visit to emergency care.Results: Among the various diagnostic groups, patients with acid-dependent organic dyspepsia had significantly more anxiety-related personality traits, less mature characters, significantly more psychiatric symptoms, and poorer self-rated health. Patients with nonspecific abdominal pain also had more personality traits associated with anxiety, although to a lesser extent. Personality factors were significantly associated with poor self-rated health. The long-term follow-up showed that patients with organic dyspepsia and non-specific abdominal pain were prescribed antidepressants and anxiolytic drugs statistically more often than patients with specific abdominal diagnoses.Conclusion: Patients with abdominal pain who seek emergency care have enhanced psychiatric comorbidity, more anxiety-related personality traits, and poorer perceived health.This trend is particularly evident in patients with a diagnosis of acid-dependent organicdyspepsia, and to a lesser degree, patients with a diagnosis of non-specific abdominal pain.These factors also predict future prescription of depression and anxiety medications. These results suggest that patients who come to emergency care with acute abdominal pain could potentially benefit from psychiatric consultation.
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| 29. |
- Lexne, Erik, et al.
(författare)
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Psychiatric symptoms among patients with acute abdominal pain Patients with organic dyspepsia report more psychiatric symptoms and rate poorer general health compared to patients with other specific abdominal diagnoses and non-specific abdominal pain at an emergency ward
- 2020
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Ingår i: Scandinavian Journal of Gastroenterology. - : Taylor & Francis Group. - 0036-5521 .- 1502-7708. ; 55:7, s. 769-776
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Tidskriftsartikel (refereegranskat)abstract
- Background:Abdominal pain is a common cause of visits to emergency facilities. It is related to psychiatric disorders in primary care, but it is unclear if this also holds in emergency departments. Objective:Is to explore potential differences between diagnostic groups in patients with acute abdominal pain in an emergency ward regarding concurrent somatic-and psychiatric symptoms, 'Length of stay' (LOS) and perceived health. Method:The patients (N = 137) were divided into three groups; organic dyspepsia, specific abdominal diagnoses, and non-specific abdominal pain. The Prime-MD results for extra gastrointestinal symptoms (outside the gastrointestinal tract), psychiatric symptoms, frequency of symptoms, self-reported health, and LOS within the month before admittance were compared between the diagnostic groups. Results: There was a significant positive correlation between the number of physical extra gastrointestinal and psychiatric symptoms (p < .001), especially regarding anxiety (p < .001) and depression (p = .002). Patients with organic dyspepsia reported significantly more total (p = .016), extragastrointestinal (p = .026) (chest pain;p = .017, dizziness;p = .004, palpitations;p = .005, insomnia;p = .005 and worries;p = .001), and summarized anxiety and depression symptoms (p = .001-0.002) besides poorer general health (p < .001) compared to other abdominal conditions. Also, organic dyspepsia patients needed longer hospital stay than the non-specific abdominal group (p = .002) but similar to the specific abdominal disorders group. Conclusion:Organic dyspepsia is accompanied by more co-occurring physical, anxiety and depression symptoms as well as poorer perceived health than other abdominal pain conditions and comparably increased LOS. This suggests that psychiatric consultations might be beneficial for diagnosing and treating psychiatric comorbidity in emergency care.
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| 30. |
- Lexne, Erik, et al.
(författare)
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Temperament and character in patients with acute abdominal pain
- 2018
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Ingår i: Comprehensive Psychiatry. - : Saunders Elsevier. - 0010-440X .- 1532-8384. ; 87, s. 128-133
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundSeveral conditions presenting with abdominal pain are associated with specific personality factors although it is unclear if this is true also in emergency clinic settings.ObjectiveTo study personality factors among patients with acute abdominal pain in an emergency ward.MethodsConsecutive patients (N = 165) with abdominal symptoms at an emergency clinic were administrated the Temperament and Character Inventory (TCI). Three main groups were identified; specific abdominal diagnoses, (N = 77), non-specific abdominal pain, (N = 67) and organic dyspepsia (N = 21). TCI results were compared between clinical groups and a control group (N = 122).ResultsAs compared to individuals with specific abdominal diagnoses and controls, those with organic dyspepsia were significantly more anxious (harm avoidance), (p = 0.003), and had lower ability to cooperate (cooperativeness) (p = 0.048 and p = 0.004 respectively). They were also significantly more unpretentious (self-transcendence) compared to individuals with specific abdominal diagnoses (p = 0.048), non-specific abdominal pain (p = 0.012) and controls (p = 0.004) and evidenced less mature character (sum of self-directedness and cooperativeness) compared to those with specific abdominal diagnoses and controls (p = 0.003).ConclusionIndividuals seeking care at an emergency clinic with organic dyspepsia showed a distinguishable pattern of personality features that distinguished them from the other comparison groups. Therefore an evaluation of personality factors may add a new dimension to the diagnostic investigation in the emergency care of abdominal pain and contribute to the optimization of the treatment of organic dyspepsia.
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| 31. |
- Nordin, Conny, 1944-, et al.
(författare)
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Temperament and character in pathological gambling
- 2007
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Ingår i: Journal of Gambling Studies. - : Springer Science and Business Media LLC. - 1050-5350 .- 1573-3602. ; 23:2, s. 113-120
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Tidskriftsartikel (refereegranskat)abstract
- Objective: We have studied temperament and character in pathological gambling (PG). Methods: Thirty-eight DSM-IV verified pathological gamblers (31 males and 7 females, mean age 35.4 ± 10.4 years) were tested with Cloninger's Temperament and Character Inventory (TCI). Matched controls were chosen from the normal population. Results: Pathological gamblers scored higher on the temperament factors novelty seeking (NS) and harm avoidance (HA). The most pronounced difference was found in the character factor self-directedness (SD). The pathological gamblers differed from controls in cooperativeness and self-transcendence. A personality disorder was found in 29% of the pathological gamblers 84% of whom scored either low on SD and high on impulsivity or had a more dishonest behaviour. Two-thirds of pathological gamblers showed immature character with or without high HA in temperament. The other third showed normal-character extravagant behaviour (86%), high impulsivity (36%) and less responsibility (50%) being the most common personality traits. Conclusion: HA and NS might be trait-like characteristics in PG. © 2007 Springer Science+Business Media, Inc.
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| 32. |
- Nylander, Filip, 1986, et al.
(författare)
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New features of arabinoxylan ethers revealed by using multivariate analysis
- 2019
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617. ; 204, s. 255-261
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Tidskriftsartikel (refereegranskat)abstract
- © 2018 Hemicelluloses are a relatively unused renewable resource. One reason is their broad structure variety that makes it hard to understand structure-property relations. In this study arbinoxylan, extracted from barley husk, was chemically modified into hydroxypropyl methyl-, hydroxypropyl- and methyl arabinoxylan. The relationship between structure and phase behavior was investigated by using multivariate analysis. The arabinoxylan ethers were characterized using mid-infrared FTIR spectroscopy and from principal components analysis, PCA, structural or physical variations between samples were visualized. With orthogonal projections to latent structures, OPLS, vibrations specific for arabinoxylan hydroxypropyl and methyl substitutions was assigned. Among the observed differences between chemical derivatives was an intensity change in the water vibration. The differences in hydration were related to clouding phase behavior of the arabinoxylan ethers. This study shows that multivariate analysis methods are useful for finding unexpected and/or hidden features in the polysaccharide structure.
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| 33. |
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| 34. |
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| 35. |
- Nylander, Olof, et al.
(författare)
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Effects of α2-adrenoceptor stimulation on luminal alkalinisation and net fluid flux in rat duodenum
- 2022
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 17:8
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Tidskriftsartikel (refereegranskat)abstract
- The sympathetic nervous system is highly involved in the regulation of gastrointestinal functions such as luminal alkalinisation and fluid absorption. However, the exact mechanisms are not clear. This study aimed to delineate how α2-adrenergic receptor stimulation reduces duodenal luminal alkalinisation and induces net fluid absorption. This was tested by perfusing the duodenum of anesthetized rats with isotonic solutions devoid of Cl- and/or Na+, in the absence and presence of the α2-adrenoceptor agonist clonidine. The clonidine was also studied in rats treated with dimethylamiloride (a Na+/H+ exchange inhibitor), vasoactive intestinal peptide, and the nicotinic receptor antagonist hexamethonium. Clonidine reduced luminal alkalinisation and induced net fluid absorption. The Cl--free solution decreased luminal alkalinisation and abolished net fluid absorption, but did not prevent clonidine from doing so. Both the Na+-free solution and luminal dimethylamiloride increased luminal alkalinisation and abolished net fluid absorption, effects counteracted by clonidine. The NaCl-free solution (D-mannitol) did not affect luminal alkalinisation, but reduced net fluid absorption. Clonidine reduced luminal alkalinisation and induced net fluid absorption in rats perfused luminally with mannitol. However, clonidine did not affect the vasoactive intestinal peptide-induced increase in luminal alkalinisation or fluid secretion. Pre-treatment with hexamethonium abolished the effects of clonidine on luminal alkalinisation and net fluid flux. In summary, our in vivo experiments showed that clonidine-induced reduction in luminal alkalinisation and induction of net fluid absorption was unrelated to luminal Na+ and Cl-, or to apical Na+/H+ or Cl-/HCO3- exchangers. Instead, clonidine seems to exert its effects via suppression of nicotinic receptor-activated acetylcholine secretomotor neurons.
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| 36. |
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| 37. |
- Nylander, Olof, et al.
(författare)
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Luminal hypotonicity increases duodenal mucosal permeability by a mechanism involving 5-hydroxytryptamine
- 2006
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Ingår i: Acta Physiologica. - : Wiley. - 1748-1708 .- 1748-1716. ; 186:1, s. 45-58
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To investigate whether 5-HT participates in the mediation of the hypotonicity-induced increase in duodenal mucosal permeability. Methods: Proximal duodenum in anesthetized rats was perfused in situ with a hypotonic NaCl solution and effects on duodenal motility, net fluid flux, mucosal permeability (blood-to-lumen clearance of 51Cr-EDTA) and the release of 5-HT into the luminal solution studied in the presence of the cyclooxygenase inhibitor indomethacin. Results: Perfusion of the duodenum with 50 mM NaCl increased mucosal permeability eightfold, increased the luminal output of 5-HT twofold and induced net fluid absorption. This rise in permeability was enhanced 25% by 5-HT (3 · 10-3 M), reduced by the 5-HT3-receptor antagonists granisetron (10-4 - 3 · 10-4 M) or ondansetron (10-5 - 10-4 M) or by the 5-HT4 receptor antagonist SB 203186 (10-4 M). The 5-HT3/4 receptor antagonist tropisetron, at 10-4 M, did not affect while 3 · 10-4 and 3 · 10-3 M augmented the hypotonicity-induced increase in mucosal permeability. Lidocaine (1.1 · 10-3 M) similarly potentiated while tetrodotoxin (5 · 10-5 M) inhibited the hypotonicity-induced increase in mucosal permeability. Compared to animals treated with indomethacin alone ondansetron and granisetron augmented (by 30-40%) while tropisetron and lidocaine reduced (by 60-70%) the hypotonicity-induced net fluid absorption. TTX and all 5-HT receptor antagonists, except tropisetron, depressed duodenal motility. Conclusions: Luminal hypotonicity increases duodenal mucosal permeability by a neural mechanism involving 5-HT acting on 5-HT3 and 5-HT4 receptors. 5-HT also appears to participate in the regulation of the hypotonicity-induced fluid flux.
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| 38. |
- Nylander, Olof, et al.
(författare)
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Modulation of mucosal permeability by vasoactive intestinal peptide or lidocaine affects the adjustment of luminal hypotonicity in rat duodenum
- 2007
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Ingår i: Acta Physiologica. - : Wiley. - 1748-1708 .- 1748-1716. ; 189:4, s. 325-335
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To examine whether modulation of paracellular solute permeability affects the capability of the duodenum to adjust luminal osmolality. Methods: Proximal duodenum was perfused with a hypotonic NaCl solution and effects on paracellular permeability to 51Cr-EDTA, motility, anion secretion, net fluid flux and perfusate osmolality determined in anaesthetized rats in the absence and presence of the COX-2 inhibitor parecoxib. Vasoactive intestinal peptide (VIP) was used to reduce and lidocaine to augment the hypotonicity-induced increase in paracellular permeability. Results: Luminal hypotonicity slightly increased paracellular permeability in control animals. Parecoxib induced motility, increased electrolyte and fluid secretion, potentiated the hypotonicity-induced rise in paracellular permeability and enhanced the capability to adjust luminal osmolality. VIP, given to control animals stimulated electrolyte and fluid secretion and augmented the capability to adjust luminal osmolality. Administration of VIP to parecoxib-treated animals increased secretion further, markedly reduced the hypotonicity-induced increase in permeability but did not change the osmolality-adjusting capability. Luminal lidocaine potentiated the hypotonicity-induced increase in permeability, reduced the hypotonicity-induced net fluid absorption and the osmolality-adjusting capability was 50% greater than in controls. Lidocaine, given to parecoxib-treated animals potentiated the hypotonicity-induced increase in permeability, reduced the hypotonicity-induced net fluid absorption but did not change the osmolality-adjusting capability. Conclusions: Vasoactive intestinal peptide reduces the osmolality-adjusting capacity of the duodenum by inhibiting paracellular solute permeability but improves this capacity by stimulating active electrolyte and fluid secretion. In contrast, lidocaine improves the osmolality-adjusting capability by augmenting paracellular solute transport but depresses it by reducing the hypotonicity-induced net fluid absorption.
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| 39. |
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| 40. |
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| 41. |
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| 42. |
- Nylander, Olof
(författare)
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The impact of cyclooxygenase inhibition on duodenal motility and mucosal alkaline secretion in anaesthetized rats
- 2011
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Ingår i: Acta Physiologica. - : Wiley. - 1748-1708 .- 1748-1716. ; 201:1, s. 179-192
-
Forskningsöversikt (refereegranskat)abstract
- Aim: Non-steroidal anti-inflammatory drugs (NSAIDs) are effective in the treatment of various human diseases. However, these drugs also have serious adverse effects in the gastrointestinal tract. In the duodenum NSAIDs inhibit mucosal alkaline secretion (DMAS), an important protective mechanism against the acid emptied from the stomach in most species, including humans. Surprisingly, NSAIDs have been shown to stimulate DMAS in an anaesthetized rat model. The aim of this review was to summarize the effects of NSAIDs and selective cyclooxygenase-2 (COX-2) inhibition on duodenal function in the rat and provide an explanation for why these drugs stimulate DMAS. Included are new data examining the effect of alpha-adrenergic drugs on duodenal motility and DMAS. Methods: Experiments were performed in anaesthetized rats. The proximal duodenum was perfused luminally with an isotonic NaCl solution. DMAS, motility, fluid flux and epithelial permeability were assessed in the absence and presence of various COX inhibitors. Results: COX inhibition induced duodenal motility, increased DMAS and augmented the sensitivity as well as the maximal response of the duodenal mucosa to lidocaine- or hypotonicity-induced increases in mucosal permeability. Furthermore, the ability of the duodenum to absorb water and to adjust osmolality in response to luminal hypotonicity was improved in COX-inhibited animals. These improvements are mediated predominately via inhibition of COX-2. Conclusions: Inhibition of COX-2 in rats with postoperative duodenal ileus induces muscle contractions, which in turn activate a nicotinic receptor-dependent intramural reflex that stimulates duodenocytes to increase the activity of apical Cl-/HCO3- exchangers, resulting in a rise in DMAS.
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| 43. |
- Nylander, Per-Olof, 1953-
(författare)
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Ethnic heterogeneity of the North-Swedish population : its origin and medical consequences
- 1992
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Northern Sweden shows a unique population structure with remarkable geographical variations in the distribution of genetic disorders as well as genetic markers like blood groups, serum groups and red cell enzyme types. The present-day population of northern Sweden is a mixture of people of Finnish, Saamish (Lappish) and Central-Swedish origin.In this thesis the ethnic heterogeneity of the North-Swedish population (counties of Västerbotten and Norrbotten) was studied using genetic blood markers, and the epidemiological impact of the ethnic heterogeneity was exemplified by studying the geographical correlation between Finnish admixture and risk factors for cardiovascular diseases. The following results were found:1 Two new ethnic marker genes were discovered: the GC*1F allele (GC serum groups) for Saamish influence and the TF*C3 allele (transferrin serum groups) for Finnish influence.2 Regional gene frequency variations in the A1A2B0 blood groups, 6-phosphogluconate dehydrogenase (6-PGD) types and transferrin and GC serum groups were studied in a sample of 4100-5600 individuals from northern Sweden distributed according to birth place into 23 subpopulations. A significant regional heterogeneity was found in all systems. The ethnic marker genes (AB0*A2, GC*1F, TF*C3, PGD*C) showed clineal variations consistent with the expected patterns of Finnish and Saamish admixture.3 Finnish and Saamish admixture was estimated in the 23 subpopulations using AB0*A2,GC*1F and PGD*C as Saamish markers and TF*C3, TF*DCHI, TF*B0-1 and SODI*2 as Finnish markers. The Saamish admixture varied between 0 and 34% and was strongest in the northern and northwestern parts of northern Sweden. The Finnish influence varied between 0 and 84% and was strongest in the northern and northeastern parts of the area. The ethnic marker genes showed significant geographical intercorrelations.4 Hypercholesterolemia showed a significant heterogeneity between the 23 subpopulations, and there was a significant geographical covariation with the degree of Finnish admixture. These results are consistent with the hypothesis that Finnish genetic influence may contribute to the development of hypercholesterolemia and thereby to the increased rate of cardiovascular diseases found in northern Sweden.The results of this study suggest that in addition to the founder effect ethnic heterogeneity is an important determinant of the structure of the North-Swedish population.
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| 44. |
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| 45. |
- Persson, Per, et al.
(författare)
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Gastrectomy causes bone loss in the rat: is lack of gastric acid responsible?
- 1993
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 1502-7708 .- 0036-5521. ; 28:4, s. 301-306
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Tidskriftsartikel (refereegranskat)abstract
- Total gastrectomy or resection of the acid-producing part of the stomach (fundectomy) in the rat induced a marked and rapid reduction in bone wet weight, ash weight, and density (expressed as ash weight in mg/mm3 bone). Bone volumes were also affected but not as much. The radius, sternum, tibia, and femur were studied. Three weeks after gastrectomy the bone ash weight was reduced by almost 30% and the density by more than 25%. Maximum bone loss (approximately 40%) occurred about 6 weeks after the operation. The bone loss after gastrectomy was somewhat greater than that after fundectomy, whereas antrectomy had a marginal effect only. The percentage trabecular bone volume, calculated from morphometric analysis of histologic sections of the tibia, was greatly reduced by gastrectomy (approximately 50%), somewhat less so by fundectomy, whereas antrectomy had little effect. We set out to study whether calcium malabsorption could explain the bone loss after gastrectomy. Gastric acid is thought to facilitate the intestinal absorption of ingested calcium by mobilizing calcium from insoluble complexes in the diet. The possibility that lack of acid might contribute to the bone loss after gastrectomy was examined in experiments in which the proton pump inhibitor omeprazole was given for 4-8 weeks at such a dose (400 mumol/kg/day) that acid secretion was blocked almost completely during the period of study. This treatment was without effect on bone. However, the possibility could not be excluded that gastrectomized rats develop calcium deficiency for some reason other than lack of acid.(
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| 46. |
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| 47. |
- Pihl, Liselotte, et al.
(författare)
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Comparative study of the effect of luminal hypotonicity on mucosal permeability in rat upper gastrointestinal tract
- 2008
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Ingår i: Acta Physiologica. - : Wiley. - 1748-1708 .- 1748-1716. ; 193:1, s. 67-78
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To investigate whether the increase in mucosal permeability in the duodenum, induced by luminal hypotonicity, also occurs in the stomach and the jejunum and whether this increase in permeability can be explained by epithelial injury. Methods: The stomach, duodenum or jejunum of the anaesthetized rat were perfused with a hypotonic solution and effects on mucosal permeability (blood-to-lumen clearance of radioactive probes); luminal alkalinization and net fluid flux were determined in the absence and presence of cyclooxygenase inhibition. Results: The hypotonicity-induced (50 mM NaCl) increase in duodenal mucosal permeability was markedly larger in cyclooxygenase-2-inhibited animals than in controls and associated with a 20% decrease in luminal alkalinization and increased fluid absorption. Perfusion with 50 mM NaCl increased duodenal mucosal permeability to all probes investigated, i.e. C-14-urea, C-14-methyl-D-glucose, Cr-51-EDTA and C-14-inulin. The percentage increase in permeability was the greatest for inulin and the lowest for urea. Luminal hypotonicity caused superficial villous tip damage in some but not in all duodenal specimens but there was no difference in morphology between controls and cyclooxygenase-2-inhibited animals. Jejunum, but not the stomach, responded to luminal hypotonicity by increasing net fluid absorption, mucosal permeability (greater than sixfold) and the rate of luminal alkalinization (> 100%). Conclusions: The stomach does not respond while the jejunum is more sensitive to hypotonicity-induced increase in mucosal permeability than the duodenum. The hypotonicity-induced increase in duodenal mucosal permeability most probably constitutes a physiological mechanism that entails widening of paracellular pathways, which facilitates the transport of osmolytes into the lumen.
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| 48. |
- Pihl, Liselotte, 1976-
(författare)
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Luminal Hypotonicity and Duodenal Functions : An Experimental Study in the Rat
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- After drinking water, the fluid quickly leaves the stomach thereby creating a hypotonic luminal environment in the duodenum. This in turn constitutes a potential threat to the integrity of the duodenal epithelium. It therefore seems highly likely that luminal hypotonicity activates physiological mechanisms that aim to increase luminal osmolality. One such physiological mechanism may be to increase mucosal permeability thereby facilitating the transport of osmolytes into the lumen.A draw-back of performing experiments in anesthetized animals is that surgery per se depresses gut functions, such as peristalsis, by mechanisms involving endogenous prostaglandins. In this thesis it is shown that inhibition of cyclooxygenase-2 (COX-2), in animals subjected to an abdominal operation, restore and/or improve duodenal functions such as motility, mucosal bicarbonate secretion, hypotonicity-induced increase in mucosal permeability and the osmolality-adjusting capability.Experiments revealed that the stomach is resistant to hypotonic challenge while the jejunum is more sensitive to hypotonicity-induced increase in mucosal permeability than the duodenum. The hypotonicity-induced increase in duodenal mucosal permeability is not due to injury but possibly reflects physiological dilatation of paracellular shunts.Luminal perfusion of the duodenum with an isotonic solution lacking Cl- decreased bicarbonate secretion while the lack of luminal Na+ increased mucosal permeability. Stimulation of bicarbonate secretion by COX-2 inhibition is to a large extent dependent on luminal Cl- while that induced by vasoactive intestinal peptide is not.The hypotonicity-induced increase in mucosal permeability involves the release and action of serotonin (5-HT) on 5-HT3 and 5-HT4 receptors and stimulation of enteric nerves strongly implicating physiological regulation of this process.
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| 49. |
- Pihl, Liselotte, et al.
(författare)
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Motility-induced but not vasoactive intestinal peptide-induced increase in luminal alkalinization in rat duodenum is dependent on luminal Cl-
- 2010
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Ingår i: Acta Physiologica. - : Wiley. - 1748-1708 .- 1748-1716. ; 200:2, s. 181-191
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To investigate whether the motility- and the vasoactive intestinal peptide (VIP)-induced increase in luminal alkalinization in the duodenum is dependent on luminal Cl-. Methods: Experiments were performed in anaesthetized rats in vivo. The proximal duodenum was perfused luminally with an isotonic solution, containing zero or low Cl- and the effects on luminal alkalinization, motility, fluid flux and epithelial permeability were determined. Parecoxib, a COX-2 inhibitor, was used to induce duodenal contractions. Results: Control rats lacked duodenal wall contractions while parecoxib-treated ones exhibited contractions throughout the experiment. Most animals had a net fluid absorption during the perfusion with isotonic NaCl. Luminal alkalinization was about 100% higher in parecoxib-treated rats than in controls. Cl--free solutions did not affect epithelial permeability or motility but decreased luminal alkalinization by >= 50% and decreased net fluid absorption in both control and parecoxib-treated animals. Reduction in luminal Cl- decreased alkalinization in a concentration-dependent manner. The parecoxib-induced increase in alkalinization was markedly reduced in the absence of luminal Cl-. VIP increased luminal alkalinization and induced fluid secretion. The lack of luminal Cl- did not affect the VIP-induced increase in alkalinization but reduced fluid secretion. Conclusions: The parecoxib-induced increase in luminal alkalinization is highly dependent on luminal Cl- and it is proposed that COX-2 inhibition, via induction of duodenal motility, enhances HCO3- efflux through stimulation of apical Cl-/HCO3- exchange in duodenal epithelial cells. Although the VIP-induced stimulation of fluid secretion is partly dependent on luminal Cl-, the VIP-induced increase in luminal alkalinization is not.
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| 50. |
- Pihl, Liselotte, et al.
(författare)
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Products of cyclooxygenase-2 depress duodenal function in rats subjected to abdominal surgery
- 2006
-
Ingår i: Acta Physiologica. - : Wiley. - 1748-1708 .- 1748-1716. ; 186:4, s. 279-90
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Abdominal surgery evokes powerful biological responses that affect gastrointestinal functions. Here we investigate the role of the COX-1 and COX-2 isoforms in postoperative duodenal ileus. Methods: Proximal duodenum of anesthetized rats was perfused in situ with isotonic or hypotonic (50 mM) NaCl. Mucosal bicarbonate secretion, motility, mucosal permeability and effluent osmolality were determined in the absence and presence of different COX inhibitors. Results: The majority of control animals had no or few duodenal contractions and bicarbonate secretion averaged 10.9 ± 1.4 µmol · cm-1 · h-1. These “paralytic” controls responded to hypotonic NaCl with a small increase in mucosal permeability. In control animals exhibiting spontaneous duodenal contractions the bicarbonate secretion was 50% higher and the hypotonicity-induced net increase in mucosal permeability 7-fold higher than in “paralytic” controls. Treatment with the selective COX-2 inhibitors rofecoxib or parecoxib induced duodenal motility, increased bicarbonate secretion and potentiated the hypotonicity-induced increase in mucosal permeability. COX-2-inhibited animals had a twofold greater capacity to adjust luminal osmolality than “paralytic” controls. The selective COX-1 inhibitor SC-560 only transiently stimulated motility and bicarbonate secretion and the hypotonicity-induced increase in mucosal permeability was smaller than in COX-2 inhibited animals. Conclusions: Abdominal surgery increases the synthesis of prostanoids, particularly via the COX-2 isoform. This compromises the ability of the duodenum to contract and to secrete HCO3- and to adjust luminal osmolality possibly via altered mucosal permeability. It is proposed that studies of gastrointestinal functions in animals subjected to abdominal surgery should include animals pre-treated with a COX-2 inhibitor.
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