| 1. |
- Boman, Jesper, et al.
(författare)
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Evolution of hybrid inviability associated with chromosome fusions
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Chromosomal rearrangements, such as inversions, have received considerable attention in the speciation literature due to their hampering effects on recombination. However, less is known about how other rearrangements, such as chromosome fissions and fusions, can affect the evolution of reproductive isolation. Here, we used crosses between populations of the wood white butterfly (Leptidea sinapis) with different karyotypes to identify genomic regions associated with hybrid inviability. We mapped candidate loci for hybrid inviability by contrasting allele frequencies between F2 hybrids that survived until the adult stage with individuals of the same cohort that succumbed to hybrid incompatibilities. Hybrid inviability factors were predominantly found in fast-evolving regions with reduced recombination rates, especially in regions where chromosome fusions have occurred. By analyzing sequencing coverage, we excluded aneuploidies as a direct link between hybrid inviability and chromosome fusions. Instead, our results point to an indirect relationship between hybrid inviability and chromosome fusions, possibly related to reductions in recombination rate caused by fusions. These results highlight that the extensive variation in chromosome numbers observed across the tree of life does not only distinguish species but can also be involved in speciation by being hotspots for the early evolution of postzygotic reproductive isolation.
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| 2. |
- Höök, Lars, et al.
(författare)
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Dualistic dosage compensation and rapid evolution of expression balance in response to W chromosome degeneration in Leptidea butterflies
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The evolution of dimorphic sex chromosomes from initially homologous autosomes is generally explained by sex-specific selection to maintain linkage between a sex determining locus and genes that are beneficial to the same sex. While initially beneficial, the strong linkage and reduced recombination causes differentiation and degeneration of many initially shared genes. Reduced copy numbers can have severe consequences for the balance of gene expression levels between sex-linked genes and the rest of the genome. Consequently, dosage compensation has evolved independently in different lineages to mitigate the detrimental effects of unbalanced expression of sex-linked genes in the heterogametic sex. However, the variation in sex chromosome regulation in different lineages, puts the need to restore expression to ancestral levels into question. In particular, a general difference has been observed between male- (XY) and female-heterogametic (ZW) systems. In contrast to the X chromosome upregulation in heterogametic males in the XY-systems, the Z chromosomes are rarely upregulated in the heterogametic females in organisms with ZW-systems. Instead, the Z chromosomes are often downregulated in the homogametic males to achieve inter-sexual balance. Although progress has been made to understand what causes this discrepancy, comparative approaches are limited by long divergence times and ancient sex chromosome systems. An attractive approach is therefore to study the evolution of gene regulation on recently derived neo-sex chromosomes, formed through fusions between ancestral sex chromosomes and autosomes. Here, we investigated dosage compensation of neo-sex chromosomes in three closely related butterflies in the cryptic wood white clade (Leptidea). Importantly, the species have acquired multiple sex chromosomes, and dosage compensation could therefore have evolved repeatedly in the clade. Our analyses reveal a mixture of gene expression patterns which suggests that distinct modes of dosage compensation have evolved on the different Z chromosomes. In addition, we detect evidence that dosage balancing mechanisms have been rapidly recruited to the youngest neo-Z chromosome, to counteract an ongoing degeneration of neo-W gametologs. The results add to a growing list of examples where diverse dosage compensation mechanisms can evolve within a single species, and suggests that various regulatory mechanisms are not restricted to specific sex chromosome systems.
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| 3. |
- Höök, Lars, et al.
(författare)
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High-density linkage maps and chromosome level genome assemblies unveil direction and frequency of extensive structural rearrangements in wood white butterflies (Leptidea spp.)
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Tidskriftsartikel (refereegranskat)abstract
- Karyotypes are generally conserved between closely related species and large chromosome rearrangements typically have negative fitness consequences in heterozygotes, potentially driving speciation. In the order Lepidoptera, most investigated species have the ancestral karyotype and gene synteny is often conserved across deep divergence, although examples of extensive genome reshuffling have recently been demonstrated. The genus Leptidea has an unusual level of chromosome variation and rearranged sex chromosomes, but the extent of restructuring across the rest of the genome is so far unknown. To explore the genomes of the wood white (Leptidea) species complex, we generated eight genome assemblies using a combination of 10X linked reads and HiC data, and improved them using linkage maps for two populations of the common wood white (L. sinapis) with distinct karyotypes. Synteny analysis revealed an extensive amount of rearrangements, both compared to the ancestral karyotype and between the Leptidea species, where only one of the three Z chromosomes was conserved across all comparisons. Most restructuring was explained by fissions and fusions, while translocations appear relatively rare. We further detected several examples of segregating rearrangement polymorphisms supporting a highly dynamic genome evolution in this clade. Fusion breakpoints were enriched for LINEs and LTR elements, which suggests that ectopic recombination might be an important driver in the formation of new chromosomes. Our results show that chromosome count alone may conceal the extent of genome restructuring and we propose that the amount of genome evolution in Lepidoptera might still be underestimated due to lack of taxonomic sampling.
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| 4. |
- Höök, Lars, et al.
(författare)
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High-density linkage maps and chromosome level genome assemblies unveil direction and frequency of extensive structural rearrangements in wood white butterflies (Leptidea spp.)
- 2023
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Ingår i: Chromosome Research. - : Springer Science and Business Media LLC. - 0967-3849 .- 1573-6849. ; 31:1
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Tidskriftsartikel (refereegranskat)abstract
- Karyotypes are generally conserved between closely related species and large chromosome rearrangements typically have negative fitness consequences in heterozygotes, potentially driving speciation. In the order Lepidoptera, most investigated species have the ancestral karyotype and gene synteny is often conserved across deep divergence, although examples of extensive genome reshuffling have recently been demonstrated. The genus Leptidea has an unusual level of chromosome variation and rearranged sex chromosomes, but the extent of restructuring across the rest of the genome is so far unknown. To explore the genomes of the wood white (Leptidea) species complex, we generated eight genome assemblies using a combination of 10X linked reads and HiC data, and improved them using linkage maps for two populations of the common wood white (L. sinapis) with distinct karyotypes. Synteny analysis revealed an extensive amount of rearrangements, both compared to the ancestral karyotype and between the Leptidea species, where only one of the three Z chromosomes was conserved across all comparisons. Most restructuring was explained by fissions and fusions, while translocations appear relatively rare. We further detected several examples of segregating rearrangement polymorphisms supporting a highly dynamic genome evolution in this clade. Fusion breakpoints were enriched for LINEs and LTR elements, which suggests that ectopic recombination might be an important driver in the formation of new chromosomes. Our results show that chromosome count alone may conceal the extent of genome restructuring and we propose that the amount of genome evolution in Lepidoptera might still be underestimated due to lack of taxonomic sampling.
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| 5. |
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| 6. |
- Lundin, Karin, et al.
(författare)
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Cochlear implantation in the elderly
- 2013
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Ingår i: Cochlear Implants International. - 1467-0100 .- 1754-7628. ; 14:2, s. 92-97
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To analyse complications and outcome of cochlear implant (CI) treatment in seniors receiving CIs during a 10-year period.METHODS:A total of 28 patients, 79 years or older (mean age 81.6 years), were evaluated and compared with a younger group of 76 patients, 20-60 years old (mean age 48.9 years). A retrospective study of the patients' records was performed. Data on per- and post-operative complications, pre- and post-operative speech perception, estimated cognitive skills, and social situation was extracted. A subjective score was assessed and correlated with post-operative performance.RESULTS: No severe per- or post-operative surgical complications were noted. Speech perception improved significantly after surgery (P < 0.001). The younger age group showed better results post-operatively for monosyllabic words (P < 0.01) compared with the older group with no difference seen for bi-syllabic words. In both the groups, there were no significant differences between patients living with or without social support.DISCUSSION:CI surgery for patients 79 years or older was well tolerated. Patients benefited greatly from the device with improved hearing. CI should not be denied older individuals who are otherwise in good health. Non-use in the elderly was associated with post-operative vertigo and tinnitus, severe disease and limited social support.
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| 7. |
- Näsvall, Karin, et al.
(författare)
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Activity profiles of regulatory elements and associations with the oogenesis-flight syndrome in a long-distance butterfly migrant.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The oogenesis-flight syndrome reflects the temporal allocation of energy resources between dispersal / migration and reproduction and is a key concept in research on migratory behaviour in animals. Here, we used an experimental set-up to assess how variation in host plant abundance affected the activity of regulatory elements in the painted lady butterfly (Vanessa cardui), a model species for insect migratory behaviour studies. The results indicate that recently eclosed females that had access to host plants invested in reproduction at an earlier stage and that variation in host plant abundance triggered significant differences in regulatory element activity via acetylation. By analysing functions of genes in the vicinity of significant differences in regulatory activity we pinpointed a set of categories that can be relevant for how females perceive the environment and allocate resources for either migration or reproduction. The functions of genes in the vicinity of differentially activated regions were associated with metabolism, egg shell formation, female receptivity, muscle activity, pheromone binding and mini-chromosome maintenance. Our results provide a first glimpse into the regulatory underpinnings of the oogenesis-flight syndrome and a starting point for more detailed understanding of the links between environmental variation, gene regulation and migratory behaviour in butterflies.
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| 8. |
- Näsvall, Karin, et al.
(författare)
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Base composition, codon usage and patterns of gene sequence evolution in butterflies.
- 2023
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Ingår i: Genome Biology and Evolution. - : Oxford University Press (OUP). - 1759-6653. ; 15:8
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Tidskriftsartikel (refereegranskat)abstract
- Coding sequence evolution is influenced by both natural selection and neutral evolutionary forces. In many species, the effects of mutation bias, codon usage and GC-biased gene conversion (gBGC) on gene sequence evolution have not been detailed. Quantification of how these forces shape substitution patterns is therefore necessary to understand the strength and direction of natural selection. Here, we used comparative genomics to investigate the association between base composition and codon usage bias on gene sequence evolution in butterflies and moths (Lepidoptera), including an in-depth analysis of underlying patterns and processes in one species, Leptidea sinapis. The data revealed significant G/C to A/T substitution bias at third codon position with some variation in the strength among different butterfly lineages. However, the substitution bias was lower than expected from previously estimated mutation rate ratios, partly due to the influence of gBGC. We found that A/T-ending codons were overrepresented in most species and there was a negative association between the magnitude of codon usage bias and GC-content in third codon positions. In contrast, the tRNA-gene population in L. sinapis showed higher GC-content at third codon positions compared to coding sequences in general and less overrepresentation of A/T-ending codons. There was an inverse relationship between synonymous substitutions and codon usage bias indicating selection on synonymous sites. We conclude that the evolutionary rate in Lepidoptera is affected by a complex interaction between underlying G/C -> A/T mutation bias and partly counteracting fixation biases, predominantly conferred by overall purifying selection, gBGC and selection on codon usage.
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| 9. |
- Näsvall, Karin, et al.
(författare)
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Host plant diet affects growth and induces altered gene expression and microbiome composition in the wood white (Leptidea sinapis) butterfly
- 2021
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Ingår i: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 30:2, s. 499-516
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Tidskriftsartikel (refereegranskat)abstract
- In a time with decreasing biodiversity, especially among insects, a detailed understanding about specific resource utilization strategies is crucial. The physiological and behavioural responses to host switches in phytophagous insects are poorly understood. Earlier studies indicate that a host plant switch might be associated with distinctive molecular and physiological responses in different lineages. Expanding the assessment of such associations across Lepidoptera will reveal if there are general patterns in adaptive responses, or if each switch event is more of a unique character. We investigated host plant preference, fitness consequences, effects on expression profiles and gut microbiome composition in two common wood white (Leptidea sinapis) populations with different host plant preferences from the extremes of the species distribution area (Sweden and Catalonia). Our results show that female Catalonian wood whites lack preference for either host plant (Lotus corniculatus or L. dorycnium), while Swedish females laid significantly more eggs on L. corniculatus. Individuals from both populations reared on L. dorycnium had longer developmental times and smaller body size as adults. This indicates that both environmental and genetic factors determine the choice to use a specific host plant. Gene expression analysis revealed a more pronounced response to host plant in the Catalonian compared to the Swedish population. In addition, host plant treatment resulted in a significant shift in microbiome community structure in the Catalonian population. Together, this suggests that population specific plasticity associated with local conditions underlies host plant utilisation in wood whites.
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| 10. |
- Näsvall, Karin, et al.
(författare)
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Nascent evolution of recombination rate as a consequence of chromosomal rearrangements.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Reshuffling of genetic variation occurs both by independent assortment of chromosomes and by homologous recombination. Such reshuffling can generate novel allele combinations and break linkage between advantageous and deleterious variants which increases both the potential and the efficacy of natural selection. Here we used high-density linkage maps to characterize global and regional recombination rate variation in two populations of the wood white butterfly (Leptidea sinapis) with distinct karyotypes. The recombination data were combined with estimates of genetic diversity and measures of selection to assess associations between chromosomal rearrangements, crossing over, maintenance of genetic diversity and adaptation. Our data show that the recombination rate is influenced by both chromosome size and karyotype, but that the difference in recombination rate between karyotypes is reduced as a consequence of a higher frequency of double crossovers in larger chromosomes. As expected from effects of selection on linked sites, we observed an overall positive association between recombination rate and genetic diversity in both populations. Our results also revealed a significant effect of chromosomal rearrangements on the rate of intergenic diversity change between populations, but limited effects on polymorphisms in coding sequence. We conclude that chromosomal rearrangements can have considerable effects on the recombination landscape and consequently influence both maintenance of genetic diversity and efficiency of selection in natural populations.
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| 11. |
- Näsvall, Karin, et al.
(författare)
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Nascent evolution of recombination rate differences as a consequence of chromosomal rearrangements
- 2023
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Ingår i: PLOS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 19:8
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Tidskriftsartikel (refereegranskat)abstract
- Reshuffling of genetic variation occurs both by independent assortment of chromosomes and by homologous recombination. Such reshuffling can generate novel allele combinations and break linkage between advantageous and deleterious variants which increases both the potential and the efficacy of natural selection. Here we used high-density linkage maps to characterize global and regional recombination rate variation in two populations of the wood white butterfly (Leptidea sinapis) that differ considerably in their karyotype as a consequence of at least 27 chromosome fissions and fusions. The recombination data were compared to estimates of genetic diversity and measures of selection to assess the relationship between chromosomal rearrangements, crossing over, maintenance of genetic diversity and adaptation. Our data show that the recombination rate is influenced by both chromosome size and number, but that the difference in the number of crossovers between karyotypes is reduced as a consequence of a higher frequency of double crossovers in larger chromosomes. As expected from effects of selection on linked sites, we observed an overall positive association between recombination rate and genetic diversity in both populations. Our results also revealed a significant effect of chromosomal rearrangements on the rate of intergenic diversity change between populations, but limited effects on polymorphisms in coding sequence. We conclude that chromosomal rearrangements can have considerable effects on the recombination landscape and consequently influence both maintenance of genetic diversity and efficiency of selection in natural populations.
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| 12. |
- Näsvall, Karin, 1974-
(författare)
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Rates and patterns of genome evolution in Lepidoptera
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The evolutionary consequences of genome restructuring and chromosomal rearrangements can be significant, but the underlying mechanisms are poorly understood. This thesis explores the relationships between genome restructuring, recombination, and maintenance of genetic diversity in different butterfly species. I also investigate the genetic underpinnings of different types of adaptations in two butterfly species with distinct life-history characteristics and adaptations. In Chapter I, whole genome alignments and linkage maps were used to characterize inter- and intra-specific chromosomal rearrangements in wood white butterflies (Leptidea spp.), revealing extensive reorganization of the chromosomes predominantly driven by fusions and fissions. Several fusion-fission polymorphisms were found segregating within populations, confirming the dynamic and ongoing process of karyotype evolution. In Chapter II, I used the linkage map information to show that chromosomal rearrangements have had considerable effects on the recombination landscape and maintenance of genetic diversity. Chapter III presents a detailed annotation of the genome of a long-distance migrant, the painted lady butterfly (Vanessa cardui). The annotation was used to identify expanded gene families, providing insight into the genetic underpinnings of this unique life-history. Here, I also developed linkage maps confirming a well-preserved karyotype in this species and showed that chromosome size is a major determinant of the recombination landscape. In Chapter IV, I explored the relationship between nucleotide composition, codon usage, and substitution rates across multiple Lepidoptera species, in an attempt to disentangle the relative effects of natural selection and neutral evolutionary forces on gene sequence evolution. The final two chapters focus on understanding the genetic basis of key adaptive traits in butterflies. Specifically, in Chapter V, I investigated potential local adaption in Leptidea sinapis by studying how host plant switch is associated with oviposition rates, larval growth and development, gene expression, and microbiome composition in populations experiencing different environmental conditions. In Chapter VI, I assessed the differential activation of regulatory elements in V. cardui females in response to host plant availability, which together with the gene family analysis in Chapter III, resulted in a set of candidate genes potentially associated with a migratory lifestyle. In conclusion, I have explored the complex interplay between proximate mechanisms and evolutionary forces shaping the genome structure and levels of genetic variation. I also investigated the genetic and regulatory underpinnings of adaptive traits in different butterfly species. In addition, I provided resources including chromosome-level genome assemblies, recombination maps, and annotations that will contribute to our understanding of evolutionary processes in general.
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| 13. |
- Näsvall, Pia, et al.
(författare)
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A comparison between intrastomal 3D ultrasonography, CT scanning and findings at surgery in patients with stomal complaints
- 2014
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Ingår i: International Journal of Colorectal Disease. - : Springer. - 0179-1958 .- 1432-1262. ; 29:10, s. 1263-1266
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Since there are no reliable investigative tools for imaging parastomal hernia, new techniques are needed. The aim of this study was to assess the validity of intrastomal three-dimensional ultrasonography (3D) as an alternative to CT scanning for the assessment of stomal complaints.METHOD: Twenty patients with stomal complaints, indicating surgery, were examined preoperatively with a CT scan in the supine position and 3D intrastomal ultrasonography in the supine and erect positions. Comparison with findings at surgery, considered to be the true state, was made.RESULTS: Both imaging methods, 3D ultrasonography and CT scanning, showed high sensitivity (ultrasound 15/18, CT scan 15/18) and specificity (ultrasound 2/2, CT scan 1/2) when judged by a dedicated radiologist. Corresponding values for interpretation of CT scans in routine clinical practice was for sensitivity 17/18 and for specificity 1/2.CONCLUSION: 3D ultrasonography has a high validity and is a promising alternative to CT scanning in the supine position to distinguish a bulge from a parastomal hernia.
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| 14. |
- Näsvall, Pia, 1967-
(författare)
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Parastomal hernia : investigation and treatment
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundParastomal hernia is a common stoma complication causing the patient considerable inconvenience. The patient becomes aware of a bulge around the stoma, but a bulge is not always a parastomal hernia and diagnostics must be performed to enable differential treatment. It is difficult to distinguish between a bulge and a hernia. Results based on clinical examination and computerised tomography (CT) in the supine position, have not been convincing. Three-dimensional intrastomal ultrasonography (3D US) is a novel technique shown to be promising in the assessment of stoma complaints. Two studies were performed to determine inter- and intra-observer reliability as well as the validity of 3D US as an alternative to CT when assessing stoma complaints.There are numerous options for the treatment of parastomal hernia, but none has been shown superior. In the recent decades the use of mesh in the repair of incisional and inguinal hernia has become routine. New materials must be evaluated as there are potential morbidity and even mortality risks with mesh repair. As recurrence of a parastomal hernia is an even greater challenge, the method of choice should have a low risk for recurrence. A prospective multicenter study was performed to evaluate safety and recurrence rate when using Parastomal Hernia Patch BARDTM (PHP), a mesh specially designed for parastomal hernia repair.A stoma has a profound impact on the patient´s daily life, both physical and psychological. A parastomal hernia with its associated risk for leakage and incarceration worsens the situation. Patient driven assessment of healthcare outcome is important if we are to improve medical care. A quality of life (QoL) survey was performed to assess the impact of parastomal bulging and hernia on the patient´s daily life.MethodsForty patients were investigated and the 3D US images were twice evaluated by two or three physicians to assess inter- and intra-observer reliability. Totally 20 patients with stoma complaints requiring surgery were examined with CT and 3D US prior to surgery. The findings were compared with the intraoperative findings – regarded as the true outcome.Fifty patients with parastomal hernia requiring surgery were enrolled from three hospitals. Patients were followed up one month and one year after repair using PHP.Patients still alive in 2008 who had been operated between1996 and 2004 for rectal cancer in Uppsala/Örebro-, Stockholm/Gotland-, and Northern Regions (986 patients) and registered in the Swedish Rectal Cancer Registry (SRCR) were invited to fill in four QoL questionnaires.ResultsInter-observer agreement using 3D US reached 80% for the last 10 patients examined, with a kappa value of 0.70. Intra-observer agreement for two examiners was 80% and 95%. The learning curve levelled out at 30 patients. Both CT and 3D US showed high sensitivity and specificity when compared with intraoperative findings.After surgery for parastomal hernia with a PHP, the complication rate at one month was 30% and recurrence rate at one year was 22%. Twelve patients were reoperated within one year.In the QoL study, 31.5% of the patients with a stoma reported a bulging or a hernia. 11.7% had been operated for parastomal hernia. A hernia or a bulge gave rise to significantly more pain and impaired stoma function. Overall QoL was inferior in patients with a permanent stoma compared to a group without a stoma.
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| 15. |
- Näsvall, Pia, 1967-, et al.
(författare)
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Parastomal hernia repair with intraperitoneal mesh
- 2017
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Ingår i: Surgery Research and Practice. - : Hindawi Publishing Corporation. - 2356-7759 .- 2356-6124. - 9789176012413 ; 2017
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Tidskriftsartikel (refereegranskat)abstract
- Purpose. Parastomal hernia is a common complication following a stoma and may cause leakage or incarceration. No optimal treatment has been established, and existing methods using mesh repair are associated with high recurrence rates and a considerable risk for short- and long-term complications including death. A double-layer intraperitoneal on-lay mesh (IPOM), the Parastomal Hernia Patch (BARD™), consisting of ePTFE and polypropylene, has been developed and tailored to avoid recurrence. To evaluate the safety of and recurrence rate using this mesh, a nonrandomised prospective multicentre study was performed. Method. Fifty patients requiring surgery for parastomal hernia were enrolled. Clinical examination and CT scan prior to surgery were performed. All patients were operated on using the Parastomal Hernia Patch (BARD). Postoperative follow-up at one month and one year was scheduled to detect complications and hernia recurrence. Results. The postoperative complication rate at one month was 15/50 (30%). The parastomal hernia recurrence rate at one year was 11/50 (22%). The reoperation rate at one month was 7/50 (14%), and further 5/50 (10%) patients were reoperated on during the following eleven months.
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| 16. |
- Näsvall, Pia, et al.
(författare)
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Quality of life in patients with a permanent stoma after rectal cancer surgery
- 2017
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Ingår i: Quality of Life Research. - : Springer Science and Business Media LLC. - 0962-9343 .- 1573-2649. ; 26:1, s. 55-64
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Tidskriftsartikel (refereegranskat)abstract
- AIM: Health-related quality of life (HRQoL) assessment is important in understanding the patient's perspective and for decision-making in health care. HRQoL is often impaired in patients with stoma. The aim was to evaluate HRQoL in rectal cancer patients with permanent stoma compared to patients without stoma.METHODS: 711 patients operated for rectal cancer with abdomino-perineal resection or Hartman's procedure and a control group (n = 275) operated with anterior resection were eligible. Four QoL questionnaires were sent by mail. Comparisons of mean values between groups were made by Student´s independent t test. Comparison was made to a Swedish background population.RESULTS: 336 patients with a stoma and 117 without stoma replied (453/986; 46 %). A bulging or a hernia around the stoma was present in 31.5 %. Operation due to parastomal hernia had been performed in 11.7 % in the stoma group. Mental health (p = 0.007), body image (p < 0.001), and physical (p = 0.016) and emotional function (p = 0.003) were inferior in patients with stoma. Fatigue (p = 0.019) and loss of appetite (p = 0.027) were also more prominent in the stoma group. Sexual function was impaired in the non-stoma group (p = 0.034). However in the stoma group, patients with a bulge/hernia had more sexual problems (p = 0.004). Pain was associated with bulge/hernia (p < 0.001) and fear for leakage decreased QoL (p < 0.001). HRQoL was impaired compared to the Swedish background population.CONCLUSION: Overall HRQoL in patients operated for rectal cancer with permanent stoma was inferior compared to patients without stoma. In the stoma group, a bulge or a hernia around the stoma further impaired HRQoL.
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| 17. |
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| 18. |
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| 19. |
- Näverlo, Simon, et al.
(författare)
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Quality of life after end colostomy without mesh and with prophylactic synthetic mesh in sublay position : one-year results of the STOMAMESH trial
- 2019
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Ingår i: International Journal of Colorectal Disease. - : Springer. - 0179-1958 .- 1432-1262. ; 34:9, s. 1591-1599
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To determine whether prophylactic mesh in a sublay position has an impact on the quality-of-life (QoL) of patients receiving an end colostomy.Methods: One-year follow-up of patients from the STOMAMESH trial, a randomized controlled double-blinded multicenter study. Patients were randomized to either prophylactic synthetic mesh with a cruciform incision in the center, placed in sublay position, or no prophylactic mesh. Patients attended a 1-year visit and responded to the questionnaires EORTC QLQ C-30 and CR-38. The impact of having a mesh on QoL was determined by comparing a group of patients receiving a mesh with a group without. A subgroup analysis was made depending on whether a PSH was clinically present or not.Results: Of the 232 randomized patients, 211 patients reached the 1-year clinical follow-up. The response rate of these 211 patients was 70%. No differences were seen in global QoL between the groups. Mesh patients reported significantly less stoma-related problems (p = 0.014) but more sexual problems in males (p = 0.022). When excluding patients with a clinical diagnosis of PSH, the difference in stoma-related problems remained while no significant difference was seen regarding sexual problems in males.Conclusions: When forming an end colostomy, prophylactic synthetic mesh in a sublay position did not affect global QoL at 1-year follow-up, but stoma-related problems were fewer even in the presence of a clinically diagnosed PSH.
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| 20. |
- Odensten, Christoffer, et al.
(författare)
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Parastomal hernia repair; seldom performed and seldom reported : Results from a nationwide survey
- 2020
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Ingår i: Scandinavian Journal of Surgery. - : Sage Publications. - 1457-4969 .- 1799-7267. ; 109:2, s. 96-101
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Parastomal hernia is common, but there are few population-based studies showing the frequency and outcome of parastomal hernia repair in routine surgical practice. The aim of this study was to identify patients undergoing surgery for parastomal hernia in Sweden and to define risk factors for complication and recurrence.METHODS: A broad search of the Swedish National Patient Register 1998-2007 for all possible parastomal hernia repairs using surgical procedure codes. Records of all patients identified were reviewed and those with a definite parastomal hernia procedure were included and analyzed.RESULTS: A total of 71 patients were identified after review of the records. The most common reason for surgery was cosmetic and the most frequent method was relocation of the stoma. Parastomal hernia recurrence rate was 18% during follow-up of a minimum 2 years. Overall, a surgical complication occurred in 32%. Possible risk factors were analyzed including emergency surgery versus planned, gender, age, indication for surgery, and method of surgery; none of which was significant.CONCLUSION: The frequency of parastomal hernia procedures was much lower than suggested by previous studies. The number of procedures per surgeon was even lower than expected. No specific risk factor could be identified. Parastomal hernia auditing in the form of a nationwide quality register should be mandatory. Centralization should be considered.
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| 21. |
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| 22. |
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| 23. |
- Odensten, Christoffer, et al.
(författare)
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Use of prophylactic mesh when creating a colostomy does not prevent parastomal hernia : a randomized controlled trial—STOMAMESH
- 2019
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Ingår i: Annals of Surgery. - : Wolters Kluwer. - 0003-4932 .- 1528-1140. ; 269:3, s. 427-431
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of this study was to determine whether parastomal hernia (PSH) rate can be reduced by using synthetic mesh in the sublay position when constructing permanent end colostomy. The secondary aim was to investigate possible side-effects of the mesh.Background: Prevention of PSH is important as it often causes discomfort and leakage from stoma dressing. Different methods of prevention have been tried, including several mesh techniques. The incidence of PSH is high; up to 78%.Methods: Randomized controlled double-blinded multicenter trial. Patients undergoing open colorectal surgery, including creation of a permanent end colostomy, were randomized into 2 groups, with and without mesh. A lightweight polypropylene mesh was placed around the colostomy in the sublay position. Follow up after 1 month and 1 year. Computerized tomography and clinical examination were used to detect PSH at the 1-year follow up. Data were analyzed on an intention-to-treat basis.Results: After 1 year, 211 of 232 patients underwent clinical examination and 198 radiologic assessments. Operation time was 36 minutes longer in the mesh arm. No difference in rate of PSH was revealed in the analyses of clinical (P = 0.866) and radiologic (P = 0.748) data. There was no significant difference in perioperative complications.Conclusions: The use of reinforcing mesh does not alter the rate of PSH. No difference in complication rate was seen between the 2 arms. Based on these results, the prophylactic use of mesh to prevent PSH cannot be recommended.
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| 24. |
- Palahi i Torres, Aleix, et al.
(författare)
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The fine-scale recombination rate variation and associations with genomic features in a butterfly
- 2023
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051 .- 1549-5469. ; 33:5, s. 810-823
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Tidskriftsartikel (refereegranskat)abstract
- Recombination is a key molecular mechanism that has profound implications on both micro- and macroevolutionary processes. However, the determinants of recombination rate variation in holocentric organisms are poorly understood, in particular in Lepidoptera (moths and butterflies). The wood white butterfly (Leptidea sinapis) shows considerable intraspecific variation in chromosome numbers and is a suitable system for studying regional recombination rate variation and its potential molecular underpinnings. Here, we developed a large whole-genome resequencing data set from a population of wood whites to obtain high-resolution recombination maps using linkage disequilibrium information. The analyses revealed that larger chromosomes had a bimodal recombination landscape, potentially caused by interference between simultaneous chiasmata. The recombination rate was significantly lower in subtelomeric regions, with exceptions associated with segregating chromosome rearrangements, showing that fissions and fusions can have considerable effects on the recombination landscape. There was no association between the inferred recombination rate and base composition, supporting a limited influence of GC-biased gene conversion in butterflies. We found significant but variable associations between the recombination rate and the density of different classes of transposable elements, most notably a significant enrichment of short interspersed nucleotide elements in genomic regions with higher recombination rate. Finally, the analyses unveiled significant enrichment of genes involved in farnesyltranstransferase activity in recombination coldspots, potentially indicating that expression of transferases can inhibit formation of chiasmata during meiotic division. Our results provide novel information about recombination rate variation in holocentric organisms and have particular implications for forthcoming research in population genetics, molecular/genome evolution, and speciation.
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| 25. |
- Renman, David, et al.
(författare)
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Attitudes to and Experiences of Physical Activity After Colon Cancer Diagnosis Amongst Physically Active Individuals : A Qualitative Study
- 2022
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Ingår i: Cancer Control. - : Sage Publications. - 1073-2748 .- 1526-2359. ; 29
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Physical activity improves survival, reduces postoperative complications, and reduces the risk of developing colon cancer. It is important to maintain physical activity after receiving a diagnosis of colon cancer to improve postoperative recovery. Individuals who are physically active and diagnosed with colon cancer presumably have different motivations to maintain physical activity compared to their sedentary counterparts.OBJECTIVE: Enlighten how the diagnosis of colon cancer might affect physically active individuals in their attitude and experiences towards physical activity.METHODS: A qualitative study using content analysis was conducted in northern Sweden based on semi-structured telephone interviews of twenty patients diagnosed with colon cancer. All participants met the recommendations for physical activity issued by the World Health Organization.RESULTS: Participants were between 50 and 88 years and 50% were male. Three main categories were identified: I'll fight the cancer and come out stronger; The diagnosis makes no difference; and The diagnosis is an obstacle for physical activity. These main categories represent the ways the individuals reacted to the diagnosis of colon cancer regarding their physical activity.CONCLUSION: Attitudes to and experience of physical activity after colon cancer diagnosis varied from a will to increase physical activity and fight the cancer, to the diagnosis putting a stop to physical activity. It is important that healthcare professionals recommend physical activity even in already physically active individuals, to encourage continued physical activity after diagnosis of colon cancer.
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| 26. |
- Ringblom, Christian, et al.
(författare)
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No reduction in parastomal hernia rate 3 years after stoma construction with prophylactic mesh : Three-year follow-up results from stomamesh-a multicenter double-blind randomized controlled trial
- 2023
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Ingår i: Annals of Surgery. - : Wolters Kluwer. - 0003-4932 .- 1528-1140. ; 277:1, s. 38-42
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The primary objective was to compare rates of parastomal hernia (PSH) 3 years after stoma construction with prophylactic mesh or no mesh. A secondary objective was to compare complications requiring reintervention within 3 years.BACKGROUND: Recent studies have shown that a prophylactic mesh does not reduce the rate of PSH contrary to older studies. Long-term data on efficacy and safety is however scarce.METHODS: A randomized controlled double-blind multicenter trial. Patients planned for permanent end colostomy were randomized to either prophylactic mesh in the retromuscular position around the stoma site or no mesh. They were evaluated for PSH clinically and with computed tomography (CT) 3 years after stoma construction. Medical records of all patients included were also reviewed at 3 years to detect any abdominal or abdominal wall surgery during that period.RESULTS: A total of 232 patients were randomized. At 3 years, 154 patients were available for clinical evaluation and 137 underwent a CT scan. No significant difference in PSH rates was seen between the treatment allocation arms (clinical: P=0.829 and CT: P=0.761, respectively), nor was there a significant difference in the number of reinterventions, but 2 patients had their mesh removed at emergency surgery.CONCLUSIONS: Prophylactic mesh does not reduce the rate of PSH and cannot be recommended for routine use.
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| 27. |
- Shipilina, Daria, et al.
(författare)
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Linkage mapping and genome annotation give novel insights into gene family expansions and regional recombination rate variation in the painted lady (Vanessa cardui) butterfly
- 2022
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Ingår i: Genomics. - : Elsevier. - 0888-7543 .- 1089-8646. ; 114:6
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Tidskriftsartikel (refereegranskat)abstract
- Characterization of gene family expansions and crossing over is crucial for understanding how organisms adapt to the environment. Here, we develop a high-density linkage map and detailed genome annotation of the painted lady butterfly (Vanessa cardui) -a non-diapausing, highly polyphagous species famous for its long-distance migratory behavior and almost cosmopolitan distribution. Our results reveal a complex interplay between regional recombination rate variation, gene duplications and transposable element activity shaping the genome structure of the painted lady. We identify several lineage specific gene family expansions. Their functions are mainly associated with protein and fat metabolism, detoxification, and defense against infection -critical pro-cesses for the painted lady's unique life-history. Furthermore, the detailed recombination maps allow us to characterize the regional recombination landscape, data that reveal a strong effect of chromosome size on the recombination rate, a limited impact of GC-biased gene conversion and a positive association between recom-bination and short interspersed elements.
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| 28. |
- Strigård, Karin, 1958-, et al.
(författare)
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Intrastomal 3D ultrasound : an inter- and intra-observer evaluation
- 2013
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Ingår i: International Journal of Colorectal Disease. - : Springer-Verlag New York. - 0179-1958 .- 1432-1262. ; 28:1, s. 43-47
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to determine intra- and interobserver reliability in 3D intrastomal ultrasound imaging of parastomal hernia and protrusion. A total of 40 patients were investigated. Two or three physicians evaluated the images twice, 1 month apart. Inter-observer agreement was 72 % with a kappa value 0.59. For the last 10 patients there was an agreement of 80 % with a kappa value of 0.70. Intraobserver agreement was 80 % for one observer and 95 % for the other. The learning curve levelled out at around 30 patients. Considering the learning curve of 30 patients, 3D intrastomal ultrasound is a reliable investigation method. 3D intrastomal ultrasonography has the potential to be the investigation of choice to differentiate between a bulge, a hernia, or a protrusion.
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