Association of type of oral anticoagulation with risk of bleeding in 45,114 patients with venous thromboembolism during initial and extended treatment-A nationwide register-based study.

BACKGROUND: Safety data for different anticoagulant medications in venous thromboembolism (VTE) are scarce, in particular for extended treatment. OBJECTIVES: To compare major bleeding rates depending on the choice of anticoagulation during initial (first 6 months) and extended treatment (6 months up to 5 years). METHODS: A nationwide register-based study including cancer-free patients with a first-time VTE between 2014 and 2020. Cox proportional hazards models were used to compare bleeding rates. RESULTS: We included 6558 patients on warfarin, 18,196 on rivaroxaban, and 19,498 on apixaban. At 6 months, 4750 (72.4%) remained on warfarin, 11,366 (62.5%) on rivaroxaban, and 11,940 (61.2%) on apixaban. During initial treatment, major bleeding rates were 3.86 (95% CI 3.14-4.58), 2.93 (2.55-3.31), and 1.95 (1.65-2.25) per 100 patient-years for warfarin, rivaroxaban, and apixaban, respectively, yielding adjusted hazard ratios (aHRs) of 0.89 (95% CI 0.71-1.12) for rivaroxaban versus warfarin, 0.55 (0.43-0.71) for apixaban versus warfarin, and 0.62 (0.50-0.76) for apixaban versus rivaroxaban. During extended treatment, major bleeding rates were 1.55 (1.19-1.91), 1.05 (0.85-1.26), and 0.96 (0.78-1.15) per 100 patient-years for warfarin, rivaroxaban, and apixaban, respectively, with aHRs of 0.72 (0.53-0.99) for rivaroxaban versus warfarin, 0.60 (0.44-0.82) for apixaban versus warfarin, and 0.85 (0.64-1.12) for apixaban versus rivaroxaban. Previous bleeding and increasing age were risk factors for bleeding both during initial and extended treatment. CONCLUSION: Apixaban had a lower bleeding risk than warfarin or rivaroxaban during initial treatment. During extended treatment, bleeding risk was similar for apixaban and rivaroxaban, and higher with warfarin.

Prevalence of Cancer in Patients with Venous Thromboembolism: A Retrospective Nationwide Case-Control Study in Sweden.

Cancer is a risk factor for venous thromboembolism (VTE). We aimed to define sex-specific risk of preceding cancer in patients with a first-time VTE by conducting a nationwide Swedish registry-based study including 298 172 patients with VTE and 1 185 079 matched controls. This included 44 685 patients with a diagnosis of cancer at/or within 1 year before a VTE diagnosis. Female patients with VTE had a higher multivariable adjusted odds ratios of preceding cancer than male patients with VTE (5.5 [99% confidence interval 5.4-5.7] vs 3.9 [3.8-4.0]). The highest risk of cancer in patients with VTE were found for pancreatic cancer (women: 19.6 [15.8-24.4]; men: 17.2 [13.7-21.6]) and brain cancer (women: 17.4 [12.9-23.4]; men: 17.5 [13.8-22.2]). Weak associations were seen between VTE and bladder/urothelial cancer (women: 1.31 [1.12-1.53]; men: 1.34 [1.23-1.47]), prostate cancer (men: 2.17 [2.07-2.27]), malignant melanoma (women: 2.51 [2.07-3.05]; men: 2.67 [2.23-3.18]), and kidney cancer (women: 3.20 [2.49-4.11]; men: 3.33 [2.79-4.07]). In conclusion, associations with VTE were weak for bladder/urothelial cancer and kidney cancer, and strong for pancreatic, brain, and biliary cancers.

Pulmonary embolism and deep vein thrombosis-comorbidities and temporary provoking factors in a register-based study of 1.48 million people.

Background: Knowledge on differences in patients who present with deep vein thrombosis (DVT) and those with pulmonary embolism (PE) is incomplete. Objective: To determine comorbidities and temporary provoking factors in patients with a first-time PE or DVT. Methods: This was a nationwide Swedish registry-based, retrospective, case-control study including 298 172 patients with first-time venous thromboembolism (VTE) and 1 185 079 controls matched for age, sex, and county of residence, free of VTE at the time of matching. Results: Patients with PE were older than those with DVT (mean age, 69 vs 66 years) and included slightly more women (PE, 53.4% vs DVT, 52.1%). After multivariable adjustment for comorbidities (within 7 years) and temporary provoking factors (within 3 months), heart failure (PE: adjusted odds ratio [aOR], 2.64 [99% confidence interval [CI], 2.55-2.73]; DVT: aOR, 1.66 [99% CI, 1.60-1.72]), ischemic heart disease (PE: aOR, 1.51 [99% CI, 1.47-1.56]; DVT: aOR, 1.01 [99% CI, 0.98-1.04]), and chronic obstructive pulmonary disease (PE: aOR, 2.51 [99% CI, 2.40-2.63]; DVT, 1.54 [99% CI, 1.47-1.62]) were among diseases that showed higher odds ratios in patients with PE than in those with DVT, compared with controls. Comorbidities registered within 6 months were associated with higher aORs than those within 7 years. The highest population attributable risks for PE were for cancer (13.0%) and heart failure (11.7%). Conclusion: Cardiopulmonary diseases, particularly with recent onset, imply a higher risk for PE, whereas orthopedic surgery and lower-extremity fractures carry a higher risk of DVT.

New isoforms of rat Aquaporin-4.

Aquaporin-4 (AQP4) is a brain aquaporin implicated in the pathophysiology of numerous clinical conditions including brain edema. Here we show that rat AQP4 has six cDNA isoforms, formed by alternative splicing. These are named AQP4a-f, where AQP4a and AQP4c correspond to the two classical M1 and M23 isoforms, respectively. The various isoforms are differentially expressed in kidney and brain, and their prevalence does not correspond to the level of the respective mRNAs, pointing to posttranscriptional regulation. The three isoforms lacking exon 2, AQP4b, AQP4d, and AQP4f, have an intracellular localization when expressed in cell lines and do not transport water when expressed in Xenopus oocytes. In contrast, the largest of the new isoforms, AQP4e, which contains a novel N-terminal domain, is localized at the plasma membrane in cell lines and functions as a water transporter in Xenopus oocytes.

Huntingtin triplet-repeat locus is stable under long-term Fen1 knockdown in human cells.

The influence of Fen1 loss on trinucleotide-repeat expansion varies between species. In yeast, loss or haploinsufficiency of the Fen1 homolog Rad27 leads to triplet expansion. In mice, haploinsufficiency of Fen1 leads to expansion of a Huntingtin locus CAG repeat. However, no expansion was seen of a (CTG)(n).(CAG)(n) repeat in a Myotonic dystrophy type 1 (DM1) knock-in model. In contrast, in Drosophila, a SCA7 CAG90 repeat was completely stable in a series of strains with mutations of DNA repair genes, among them PCNA, MutS and Fen1. In light of the apparent species dependence of triplet expansion, we have investigated in human cells the effect of Fen1 loss on the Huntingtin CAG repeat. We constructed a cell line, Fen-Rex, which in a reversible manner allows regulation of endogenous Fen1 expression, by using RNA interference (RNAi). Keeping the Fen1 protein knocked down 10-fold over 27 successive cell passages (10(17)-fold expansion in total) and measuring the Huntingtin triplet expansion by both length profiling of PCR products on PAGE gels, and cloning and sequencing of the repeat region, we find the Huntingtin locus completely stable. Our results argue against a role for Fen1 in triggering Huntingtin triplet expansion in human cells.

'Theatre as an eye-opener': How theatre may contribute to knowledge about living close to persons with dementia.

The aim of the study was to show how theatre may yield insight into living close to persons with dementia. Six focus group interviews with health providers and close relatives were conducted. The informants, recruited by the local dementia associations and nursing homes in three Norwegian towns, were invited to see the theatre play Our Wonderful World. Further, they were asked to send written reflections from during and after the play to the project group within one week. Transcripts from the interviews and reflection notes were analysed inspired by a phenomenological approach. After discussion and reflection on each member's preliminary themes, a common meaning of the informants' experiences were gained. Informants gave written informed consent and The Norwegian Social Sciences Data Services assessed the project. Data showed that the two groups of informants had different knowledge of the patients' earlier life and thoughts of the future. They became aware of how different they experienced their responsibility, and they expressed different attitudes as to how open one should be about the illness. Findings are summarised in four themes: Bright memories and sombre views of the future, Life responsibility versus professional responsibility and Shielding versus openness. The drama creates emotional engagement that enabled the informants to transcend their personal experiences and gain new knowledge.

Early upregulation in nasal epithelium and strong expression in olfactory bulb glomeruli suggest a role for Aquaporin-4 in olfaction.

Aquaporin-4 (AQP4) has been reported to be upregulated post-partum in pregnancy and in early lung development. Several technical challenges exist in measuring AQP4 protein levels, among them sensitivity to detergent solubilization, sample heating and gel composition. Here we have optimized quantification of AQP4 using immuno-blots. Using improved methodology we find no evidence for AQP4 upregulation post-partum or in the early lung development. However, in the nasal epithelium AQP4 is upregulated as early as in the brain. Furthermore, AQP4 is strongly expressed in the glomerulus, the synaptic unit of the olfactory bulb, suggesting a role for AQP4 in olfactory function.

Tolerated wobble mutations in siRNAs decrease specificity, but can enhance activity in vivo.

RNA interference (RNAi) has become an invaluable tool for functional genomics. A critical use of this tool depends on an understanding of the factors that determine the specificity and activity of the active agent, small interfering RNA (siRNA). Several studies have concluded that tolerance of mutations can be considerable and hence lead to off-target effects. In this study, we have investigated in vivo the toleration of wobble (G:U) mutations in high activity siRNAs against Flap Endonuclease 1 (Fen1) and Aquaporin-4 (Aqp4). Mutations in the central part of the antisense strand caused a pronounced decrease in activity, while mutations in the 5' and 3'ends were tolerated very well. Furthermore, based on analysis of nine different mutated siRNAs with widely differing intrinsic activities, we conclude that siRNA activity can be significantly enhanced by wobble mutations (relative to mRNA), in the 5' terminal of the antisense strand. These findings should facilitate design of active siRNAs where the target mRNA offers limited choice of siRNA positions.

'Brightness in dark places': theatre as an arena for communicating life with dementia.

The aim of this study was to use artistic expressions on a theatrical stage for communicating life with dementia, as portrayed in literary texts and to explore whether such communication would help relatives of people suffering from dementia gain knowledge of their situation. Life with dementia was portrayed through four theatre performances with actors reading excerpts from literary texts combined with music. Relatives were invited to the performances and to participate in focus groups following the events. Analysis revealed that the participants recognized episodes in the texts and were touched. This resulted in new knowledge. The aesthetic expression was of great significance. The use of the theatre stage as an arena for communicating knowledge became a meaningful experience. The performances enabled identification with roles on the stage, created a feeling of community with the audience and contributed to an experience of dignity.

Human OXR1 maintains mitochondrial DNA integrity and counteracts hydrogen peroxide-induced oxidative stress by regulating antioxidant pathways involving p21.

The oxidation resistance gene 1 (OXR1) prevents oxidative stress-induced cell death by an unknown pathway. Here, depletion of human OXR1 (hOXR1) sensitized several human cell lines to hydrogen peroxide-induced oxidative stress, reduced mtDNA integrity, and increased apoptosis. In contrast, depletion of hOXR1 in cells lacking mtDNA showed no significant change in ROS or viability, suggesting that OXR1 prevents intracellular hydrogen peroxide-induced increase in oxidative stress levels to avoid a vicious cycle of increased oxidative mtDNA damage and ROS formation. Furthermore, expression of p21 and the antioxidant genes GPX2 and HO-1 was reduced in hOXR1-depleted cells. In sum, these data reveal that human OXR1 upregulates the expression of antioxidant genes via the p21 signaling pathway to suppress hydrogen peroxide-induced oxidative stress and maintain mtDNA integrity.

Small-scale purification and mass spectrometry analysis reveal a third aquaporin-4 protein isoform of 36 kDa in rat brain.

Aquaporin-4 (AQP4) is known to have two main isoforms M1 and M23 in the brain. Immunoblot analyses have provided evidence of additional AQP4 immunopositive bands, suggesting that the repertoire of AQP4 isoforms is broader than previously assumed. As isoforms beyond M1 and M23 are not observed in recombinant systems, investigation of novel isoforms requires the use of a native source. Here we report purification of AQP4 to three silver-stained proteins on SDS-PAGE. This was achieved by organelle separation, alkaline stripping of cellular membranes, detergent solubilization and multiple chromatographic steps. The three proteins that co-purified were identified as AQP4 by mass spectrometry. These results represent the first purification of AQP4 from a native source and demonstrate by mass spectrometry the presence of a third AQP4 isoform of 36 kDa in the rat brain. Immunoblots revealed that the same isoform is present in the mouse, pig, and human brain.

The molecular composition of square arrays.

Square arrays are prominent structures in plasma membranes of brain, muscle, and kidneys with an unknown function. So far, the analysis of these arrays has been restricted to freeze fracture preparations, which have shown square arrays to contain the water channel Aquaporin-4 (AQP4). Using Blue-Native PAGE immunoblots, we provide evidence that higher-order AQP4 complexes correspond to square arrays, with the AQP4 isoform M23 playing a dominant role. Our data are consistent with the idea that square arrays consist of aggregates of AQP4 tetramers complexed with multiples of dimers. By comparison, Aquaporin-1 and Aquaporin-9 form tetramers, but not higher-order complexes. AQP4 square arrays are stable under several biochemical purification steps. Analyzing the internal composition of the higher-order complexes by 2D gels, we demonstrate that the square arrays in addition to M23 also invariably contain AQP4, M1, and a novel AQP4 isoform that we call Mz. The visualization AQP4 square arrays by a rapid, biochemical assay provides new insight in the molecular organization of square arrays and gives further proof of the heterogeneity of AQP4 square arrays in vivo.