| 41. |
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| 42. |
- Bednarska, Olga, 1973-
(författare)
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Peripheral and Central Mechanisms in Irritable Bowel Syndrome : in search of links
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Irritable bowel syndrome (IBS) is a chronic visceral pain disorder with female predominance, characterized by recurrent abdominal pain and disturbed bowel habits in the absence of an identifiable organic cause. This prevalent and debilitating disease, which accounts for a substantial economic and individual burden, lacks exact diagnostic tools and effective treatment, since its pathophysiology remains uncertain. The bidirectional and multilayered brain-gut axis is a well-established disease model, however, the interactions between central and peripheral mechanisms along the brain-gut axis remain incompletely understood. One of the welldescribed triggering factors, yet accounting for only a fraction of IBS prevalence, is bacterial gastroenteritis that affects mucosal barrier function. Altered gut microbiota composition as well as disturbed intestinal mucosal barrier function and its neuroimmune regulation have been reported in IBS, however, the impact of live bacteria, neither commensal nor pathogenic, on intestinal barrier has not been studied yet. Furthermore, abnormal central processing of visceral sensations and psychological factors such as maladaptive coping have previously been suggested as centrally-mediated pathophysiological mechanisms of importance in IBS. Brain imaging studies have demonstrated an imbalance in descending pain modulatory networks and alterations in brain regions associated with interoceptive awareness and pain processing and modulation, particularly in anterior insula (aINS), although biochemical changes putatively underlying these central alterations remain poorly understood. Most importantly, however, possible associations between these documented changes on central and peripheral levels, which may as complex interactions contribute to disease onset and chronification of symptoms, are widely unknown.This thesis aimed to investigate the peripheral and central mechanisms in women with IBS compared to female healthy controls (HC) and to explore possible mutual associations between these mechanisms.In Paper I, we studied paracellular permeability and passage of live bacteria, both commensal and pathogenic through colonic biopsies mounted in Ussing chambers. We explored the regulation of the mucosal barrier function by mast cells and the neuropeptide vasoactive intestinal polypeptide (VIP) as well as a correlation between mucosal permeability and gastrointestinal and psychological symptoms. We observed increased paracellular permeability and the passage of commensal and pathogenic live bacteria in patients with IBS compared with HC, which was diminished by blocking the VIP receptors as well as after stabilizing mast cells in both groups. Moreover, higher paracellular permeability was associated with less somatic and psychological symptoms in patients.In Paper II, we aimed to determine the association between colonic mucosa paracellular permeability and structural and resting state functional brain connectivity. We demonstrated different patterns of associations between mucosa permeability and functional and structural brain connectivity in IBS patients compared to HC. Specifically, lower paracellular permeability in IBS, similar to the levels detected in HC, was associated with more severe IBS symptoms and increased functional and structural connectivity between intrinsic brain resting state network and descending pain modulation brain regions. Our findings further suggested that this association between mucosa permeability and functional brain connectivity was mainly mediated by coping strategies.In Paper III, we investigated putative alterations in excitatory and inhibitory neurotransmission of aINS, as the brain’s key node of the salience network crucially involved in cognitive control, in IBS patients relative to HC and addressed possible connections with both symptoms and psychological factors. We found decreased concentrations of the excitatory neurotransmitter Glx in bilateral aINS in IBS patients compared to HC, while inhibitory neurotransmitter GABA+ levels were comparable. Further, we demonstrated hemisphere-specific associations between abdominal pain, coping and aINS excitatory neurotransmitter concentration.In conclusion, this thesis broadens the knowledge on peripheral and central mechanisms in IBS and presents novel findings that bring together the ends of brain-gut axis. Our results depict association between mucosal permeability, IBS symptoms and functional and structural connectivity engaging brain regions involved in emotion and pain modulation as well as underlying neurotransmitter alterations.
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| 43. |
- Brands Viktorsdóttir, Margrét, et al.
(författare)
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Complications according to underlying disease in children undergoing video-assisted gastrostomy
- 2017
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Ingår i: Medical Research Archives. - 2375-1916. ; 5:6
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The aim of this study was to identify short-term complications after video-assisted gastrostomy in children and to examine the association between complications and underlying disease.Methods: This was a retrospective study at a single institution. Data for all children who underwent video-assisted gastrostomy during 12 years was collected. Complications occurring within three months postoperatively were analyzed.Results: Among 421 children undergoing video-assisted gastrostomy, 402 were included in the study. The median age at surgery was two years (range one month-14 years). The most common underlying disorder was neurological disease (49%). There were two major postoperative complications and 78% had minor complications. Minor complications included granulation tissue (43%), leakage (16%), wound infection (14%), vomiting, dislodgement and pain. There was no significant difference in frequency of the various complications when compared between the underlying diseases (p=0.10-0.82). Wound infection was registered in overall 14% and occurred least frequently in children with neurologic disease and syndromes (10% and 9% respectively).Conclusion: Serious complications after video-assisted gastrostomy are rare, while minor complications occur in 78% of the children. There is no association between the frequency of complications and underlying disease according to this study.
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| 44. |
- Docherty, Neil G., et al.
(författare)
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Urinary sodium excretion after gastric bypass surgery
- 2017
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Ingår i: Surgery for Obesity and Related Diseases. - : Elsevier BV. - 1550-7289. ; 13:9, s. 1506-1514
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Tidskriftsartikel (refereegranskat)abstract
- Background: Gut-kidney signaling is implicated in sodium homeostasis and thus blood pressure regulation. Roux-en-Y gastric bypass (RYGB) surgery for morbid obesity confers a pronounced and long-lasting blood pressure lowering effect in addition to significant weight loss. Objectives: We set out to establish whether RYGB is associated with an intrinsic change in urinary sodium excretion that may contribute to the reported blood pressure lowering effects of the procedure. Methods: Five female patients (age range: 28-50 yr) without metabolic or hypertensive co-morbidities were included in a study involving four 24-hour residential visits: once before surgery and 10 days, 3 months, and 20 months after surgery. Creatinine and sodium were measured in fasting plasma samples and 24-hour urine samples and creatinine clearance, estimated glomerular filtration rate, and indices of urinary sodium excretion were calculated. Fasting and 60-minute postprandial blood samples from each study day were assayed for pro-B-type natriuretic peptide (NT-proBNP). Results: Increases in weight-normalized urinary sodium excretion of up to 2.3-fold in magnitude occurred at 20 months after surgery. Median fractional excretion of sodium at 20 months was double that seen before surgery. Fasting NT-proBNP levels were stable or increased (1.5- to 5-fold). Moreover, a small postprandial increase in NT-proBNP was observed after surgery. Conclusions: Renal fractional excretion of sodium is increased after RYGB. A shift toward increased postoperative basal and meal associated levels of NT-proBNP coincides with increased urinary sodium excretion. The data support a working hypothesis that an enhanced natriuretic gut kidney signal after RYGB may be of mechanistic importance in the blood pressure lowering effects of this procedure. (C) 2017 American Society for Metabolic and Bariatric Surgery. All rights reserved.
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| 45. |
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| 46. |
- Hedberg, Suzanne, et al.
(författare)
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BEST: Bypass equipoise sleeve trial; rationale and design of a randomized, registry-based, multicenter trial comparing Roux-en-Y gastric bypass with sleeve gastrectomy
- 2019
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Ingår i: Contemporary Clinical Trials. - : Elsevier BV. - 1551-7144 .- 1559-2030. ; 84
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Tidskriftsartikel (refereegranskat)abstract
- Background: Laparoscopic gastric bypass (LGBP) is a well-documented surgical intervention for severe obesity. Recently, laparoscopic sleeve gastrectomy (LSG) has gained increased popularity. Short-term follow-up in limited-sized randomized trials comparing LGBP and LSG show no major differences in weight-loss, adverse events, or effect on comorbidities; however, there is a lack of sufficiently powered, pragmatic, randomized controlled trials comparing the mid- and long-term results of the two methods. Method: BEST is a randomized, registry-based, multicenter trial comparing LGBP and LSG. The trial has two primary outcomes; rates of substantial complications (SC) and total body weight loss. We hypothesize that patients treated with LSG will experience 35% fewer substantial complications during the 5-year follow-up compared to patients treated with LGBP, and that the efficacy of LSG will remain within a non-inferiority margin of 5% in terms of weight loss. Our sample size calculation, using data from the Scandinavian Obesity Surgery Registry (SOReg), shows a power of 80% for SC and > 95% for weight loss at p < .025 with a total of 2100 included patients. The design of the trial will also enable comparisons within several relevant patient subgroups. Conclusions: As a large-sized, pragmatic, randomized trial, BEST will provide robust data comparing LGBP with LSG by generating long-term results on weight loss and SC's, as well as secondary outcomes and comparisons within patient subgroups. The use of a well-established registry for registration of all data facilitates a large multicenter trial, and combines the strengths of registry studies with those of a randomized trial. Clinical Trials registry: NCT 02767505. © 2019 Elsevier Inc.
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| 47. |
- Hieronymus, Fredrik, et al.
(författare)
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Influence of baseline severity on the effects of SSRIs in depression: an item-based, patient-level post-hoc analysis
- 2019
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Ingår i: The Lancet Psychiatry. - 2215-0366 .- 2215-0374. ; 6:9, s. 745-752
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Tidskriftsartikel (refereegranskat)abstract
- Background: Reports claiming that antidepressants are effective only in patients with severe depression have affected treatment guidelines but these reports usually use a disputed measure of improvement, a decrease in the sum-score of the 17-item Hamilton Depression Rating Scale (HDRS-17), and are based on group-level rather than patient-level data. Method: In this item-based, patient-level, post-hoc analysis, we pooled data from all completed, acute-phase, placebo-controlled, industry-sponsored, H DRS-based trials of the SSRIs citalopram, paroxetine, or sertraline in adult major depression. Patient-level data were pooled and subjected to item-based post-hoc analyses to assess the effect of baseline severity of depression on the response to treatment as assessed with HDRS-17 sum score, the depressed mood item of the HDRS, a six-item HDRS subscale (HDRS-6), and the remaining 11 HDRS items not included in this subscale (non-HDRS-6). Patients were defined as having non-severe depression if they had a baseline HDRS-17 sum score of 18 points or less and as having severe depression if they had a score of 27 points or more. Findings: Our study population consisted of 8262 patients from 28 placebo-controlled SSRI trials. Participants were treated with either citalopram (n=744), paroxetine (n=2981), sertraline (n=1202), fluoxetine (active-control group; n=754), or placebo (n=2581). 654 patients were defined as having non-severe depression and 1377 as having severe depression. Patients with non-severe and severe depression did not differ with respect to SSRI-induced decrease in depressed mood and other HDRS symptoms belonging to the HDRS-6 subscale. However, after exclusion of patients with rare extreme baseline values, a positive association was seen between severity and efficacy when using HDRS-17 sum score as the effect parameter. This result was largely due to a more pronounced response to treatment with respect to non-HDRS-6 items in patients with severe depression than in those with non-severe depression. This outcome could be explained by non-HDRS-6 items, more so than HDRS-6 items, being more severe and prevalent at baseline in severe than in non-severe cases; hence, less room was left for improvement in these areas in patients with non-severe depression. Interpretation: The use of an outcome measure that includes symptoms that rate low at baseline in patients with non-severe depression might result in the interpretation that SSRIs are ineffective in these patients. With respect to alleviation of HDRS-6 items, SSRIs appear to be as effective in patients with non-severe depression as in those with severe depression.
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| 48. |
- Holmström, M., et al.
(författare)
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Long-term liver-related morbidity and mortality related to chronic hepatitis C virus infection in Swedish patients with inherited bleeding disorders
- 2016
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Ingår i: Haemophilia. - : Wiley-Blackwell Publishing Inc.. - 1351-8216 .- 1365-2516. ; 22:6, s. e494-e501
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Hepatitis C virus (HCV) infection is common in patients with inherited bleeding disorders treated with clotting factor concentrates prior to the introduction of viral inactivation of these products. The long-term consequences of hepatitis C infection in Swedish patients are not fully understood.Aim: To examine the impact of HCV infection on liver-related morbidity and mortality in Swedish patients with inherited bleeding disorders.Methods: We retrospectively collected data on 183 patients with inherited bleeding disorders infected with HCV who attended the Coagulation Unit at Karolinska University Hospital, Sweden. Data regarding end-stage liver disease (ESLD), defined as presence of ascites, encephalopathy, variceal bleeding, hepatocellular carcinoma or liver-related death, were collected from the patient records and the national registers.Results: The median follow-up time was 35.9 years (IQR 29.0-41.2). A total of 41% had achieved sustained virological response (SVR) after treatment. In total, 14.2% developed ESLD at the median age of 52.6 years (IQR 46.5-64.7). Nineteen (35.8%) of all deaths were due to liver-related causes. Co-infection with human immunodeficiency virus (HIV), older age at time of infection and severe form of bleeding disorder was associated with higher risk of developing ESLD, while SVR was a strong protective factor.Conclusions: This study demonstrated that liver-related morbidity and mortality was significant in patients with bleeding disorders and HCV infection in Sweden. Patients with HCV-infection should be candidates for treatment with the new highly effective antiviral drugs, since SVR proved to be a strong protective factor.
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| 49. |
- Nordén, Rickard, 1977, et al.
(författare)
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Quantification of torque teno virus and Epstein-Barr virus is of limited value for predicting the net state of immunosuppression after lung transplantation
- 2018
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Ingår i: Open Forum Infectious Diseases. - : Oxford University Press (OUP). - 2328-8957. ; 5:4
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Tidskriftsartikel (refereegranskat)abstract
- Background. Major hurdles for survival after lung transplantation are rejections and infectious complications. Adequate methods for monitoring immune suppression status are lacking. Here, we evaluated quantification of torque teno virus (TTV) and Epstein-Barr virus (EBV) as biomarkers for defining the net state of immunosuppression in lung-transplanted patients. Methods. This prospective single-center study included 98 patients followed for 2 years after transplantation. Bacterial infections, fungal infections, viral respiratory infections (VRTI), cytomegalovirus (CMV) viremia, and acute rejections, as well as TTV and EBV levels, were monitored. Results. The levels of torque teno virus DNA increased rapidly after transplantation, likely due to immunosuppressive treatment. A modest increase in levels of Epstein-Barr virus DNA was also observed after transplantation. There were no associations between either TTV or EBV and infectious events or acute rejection, respectively, during follow-up. When Tacrolimus was the main immunosuppressive treatment, TTV DNA levels were significantly elevated 6-24 months after transplantation as compared with Cyclosporine treatment. Conclusions. Although replication of TTV, but not EBV, appears to reflect the functionality of the immune system, depending on the type of immunosuppressive treatment, quantification of TTV or EBV as biomarkers has limited potential for defining the net state of immune suppression.
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| 50. |
- Polster, Annikka, et al.
(författare)
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Heart rate variability characteristics of patients with irritable bowel syndrome and associations with symptoms
- 2018
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Ingår i: Neurogastroenterology and Motility. - : Wiley. - 1350-1925 .- 1365-2982. ; 30:7
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundDisturbed brain-gut interactions are assumed to be of importance for symptom generation in patients with irritable bowel syndrome (IBS). The autonomic nervous system (ANS) is part of the bidirectional brain-gut communication, but previous studies in IBS show diverging results. We aimed to identify subgroups of IBS patients with distinct ANS characteristics differentiating them from healthy controls (HC), and to study associations between ANS status and symptoms. MethodsHeart rate variability (HRV) was measured in IBS patients and HC (Holter monitoring: supine and standing positions with controlled respiration and ambulatory 24-hour period). Frequency (5minutes, supine, standing) and time domains (24hours, day, night) were analyzed. Validated questionnaires were used to measure gastrointestinal and psychological symptoms in patients. Patients and HC were compared on a univariate and multivariate level (principal component analysis [PCA] and orthogonal partial least squares discriminatory analysis (OPLS-DA)). Key ResultsWe analyzed 158 IBS patients (Rome III) and 39 HC. Patients differed significantly from HC in HRV parameters during daytime and in standing position. In the PCA, a majority of patients overlapped with HC, but the weighted means differed (P<.01). A subset of patients (n=30; 19%) with an aberrant global HRV profile was identified through PCA and OPLS-DA; these patients reported more severe symptoms of frequent (P<.05) and loose stools (P=.03), as well as urgency (P=.01). Conclusions and InferencesAltered ANS function was demonstrated in patients with IBS, and this might be of particular relevance for symptoms in a subset of the patients.
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