| 1. |
- Lundholm, Ida V., et al.
(författare)
-
Considerations for three-dimensional image reconstruction from experimental data in coherent diffractive imaging
- 2018
-
Ingår i: IUCrJ. - : International Union of Crystallography. - 2052-2525. ; 5, s. 531-541
-
Tidskriftsartikel (refereegranskat)abstract
- Diffraction before destruction using X-ray free-electron lasers (XFELs) has the potential to determine radiation-damage-free structures without the need for crystallization. This article presents the three-dimensional reconstruction of the Melbournevirus from single-particle X-ray diffraction patterns collected at the LINAC Coherent Light Source (LCLS) as well as reconstructions from simulated data exploring the consequences of different kinds of experimental sources of noise. The reconstruction from experimental data suffers from a strong artifact in the center of the particle. This could be reproduced with simulated data by adding experimental background to the diffraction patterns. In those simulations, the relative density of the artifact increases linearly with background strength. This suggests that the artifact originates from the Fourier transform of the relatively flat background, concentrating all power in a central feature of limited extent. We support these findings by significantly reducing the artifact through background removal before the phase-retrieval step. Large amounts of blurring in the diffraction patterns were also found to introduce diffuse artifacts, which could easily be mistaken as biologically relevant features. Other sources of noise such as sample heterogeneity and variation of pulse energy did not significantly degrade the quality of the reconstructions. Larger data volumes, made possible by the recent inauguration of high repetition-rate XFELs, allow for increased signal-to-background ratio and provide a way to minimize these artifacts. The anticipated development of three-dimensional Fourier-volume-assembly algorithms which are background aware is an alternative and complementary solution, which maximizes the use of data.
|
|
| 2. |
- Altman, D., et al.
(författare)
-
Somatic Comorbidity in Women with Overactive Bladder Syndrome
- 2016
-
Ingår i: Journal of Urology. - : Ovid Technologies (Wolters Kluwer Health). - 0022-5347 .- 1527-3792. ; 196:2, s. 473-477
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: We explore the influence of co-occurring somatic illnesses on prevalent overactive bladder in women of premenopausal age. Materials and Methods: Data for the present study were derived from a nationwide survey on complex diseases among all twins in the Swedish Twin Registry born 1959 to 1985. The present study was limited to female twins participating in the survey (12,850). Generalized estimating equations were used to estimate odds ratios with 95% CIs. Environmental and genetic influences were assessed in co-twin control analysis. Results: Generalized estimating equations analysis showed a significant association between overactive bladder and migraine (OR 1.34, 95% CI 1.15-1.57), fibromyalgia (1.83, 1.54-2.18), chronic fatigue (1.81, 1.49-2.19) and eating disorders (1.56, 1.24-1.96). There was also a significant association with allergic disorders including asthma (1.24, 1.01-1.52) and eczema (1.22, 1.04-1.43). Among reproductive disorders, urinary tract infections (1.60, 1.40-1.84), dysmenorrhea (1.53, 1.33-1.76) and pelvic pain (1.60, 1.31-1.94) showed the strongest association with overactive bladder. Results from co-twin control analysis indicated that the significant associations observed in generalized estimating equations analysis were influenced by environmental and genetic factors without a common pathway model. Conclusions: Our results suggest a multifactorial and complex pathogenesis of overactive bladder in which associations between various somatic illnesses and overactive bladder may be affected by environmental and genetic factors.
|
|
| 3. |
- Bielecki, Johan, 1982, et al.
(författare)
-
Electrospray sample injection for single-particle imaging with x-ray lasers
- 2019
-
Ingår i: Science advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 5:5
-
Tidskriftsartikel (refereegranskat)abstract
- The possibility of imaging single proteins constitutes an exciting challenge for x-ray lasers. Despite encouraging results on large particles, imaging small particles has proven to be difficult for two reasons: not quite high enough pulse intensity from currently available x-ray lasers and, as we demonstrate here, contamination of the aerosolized molecules by nonvolatile contaminants in the solution. The amount of contamination on the sample depends on the initial droplet size during aerosolization. Here, we show that, with our electrospray injector, we can decrease the size of aerosol droplets and demonstrate virtually contaminant-free sample delivery of organelles, small virions, and proteins. The results presented here, together with the increased performance of next-generation x-ray lasers, constitute an important stepping stone toward the ultimate goal of protein structure determination from imaging at room temperature and high temporal resolution.
|
|
| 4. |
- Santangelo, James S., et al.
(författare)
-
Global urban environmental change drives adaptation in white clover
- 2022
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 375
-
Tidskriftsartikel (refereegranskat)abstract
- Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural dines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale.
|
|
| 5. |
- Altenburger, A., et al.
(författare)
-
Dimorphism in cryptophytes—The case of Teleaulax amphioxeia/Plagioselmis prolonga and its ecological implications
- 2020
-
Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 6:37
-
Tidskriftsartikel (refereegranskat)abstract
- Growing evidence suggests that sexual reproduction might be common in unicellular organisms, but observations are sparse. Limited knowledge of sexual reproduction constrains understanding of protist ecology. Although Teleaulax amphioxeia and Plagioselmis prolonga are common marine cryptophytes worldwide, and are also important plastid donors for some kleptoplastic ciliates and dinoflagellates, the ecology and development of these protists are poorly known. We demonstrate that P. prolonga is the haploid form of the diploid T. amphioxeia and describe the seasonal dynamics of these two life stages. The diploid T. amphioxeia dominates during periods of high dissolved inorganic nitrogen (DIN) and low irradiance, temperature, and grazing (winter and early spring), whereas the haploid P. prolonga becomes more abundant during the summer, when DIN is low and irradiance, temperature, and grazing are high. Dimorphic sexual life cycles might explain the success of this species by fostering high genetic diversity and enabling endurance in adverse conditions.
|
|
| 6. |
- Altman, Daniel, et al.
(författare)
-
The genetic and environmental contribution to the occurrence of bladder pain syndrome: an empirical approach in a nationwide population sample.
- 2011
-
Ingår i: European urology. - : Elsevier BV. - 1873-7560 .- 0302-2838. ; 59:2, s. 280-5
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aetiology of bladder pain syndrome (BPS) remains poorly understood, and a number of pathogenic mechanisms have been proposed. The importance of genetic factors for BPS is receiving growing attention, but data so far are of a preliminary nature. OBJECTIVE: To empirically assess the genetic and environmental contribution to BPS in a population-based sample of twins. DESIGN, SETTING, AND PARTICIPANTS: The study included >25 000 twins born between 1959 and 1985. Individuals with BPS were identified using latent class cluster analysis (LCCA) based on self-reported symptoms from a nationwide screening for complex diseases in the Swedish Twin Registry. By comparing monozygotic and dizygotic twins, we estimated twin similarity and the relative proportions of phenotypic variance resulting from genetic and environmental factors. MEASUREMENTS: Twin similarity was measured. RESULTS AND LIMITATIONS: The LCCA yielded an overall BPS prevalence of 1.1% and 2.4% for males and females, respectively. In males, the contribution of genetic effects to BPS could not be assessed because of the small number of concordant twin pairs. In women, twin similarity estimates indicated a genetic component for the aetiology of BPS, but genetic factors contributed less than one-third of the total variation in susceptibility to BPS. Nonshared environmental factors accounted for more than two-thirds of the variance, whereas early nongenetic factors shared within the family were of little or no consequence to the risk of developing BPS later in life. Use of self-reported symptoms to define the disease phenotype is a limitation of the study. CONCLUSIONS: The influence of environmental factors in the development of BPS in women is substantial, whereas genetic influences are of only modest importance for the possibility of developing the disease.
|
|
| 7. |
- Arner, P., et al.
(författare)
-
Circulating Carnosine Dipeptidase 1 associates with weight loss and poor prognosis in gastrointestinal cancer
- 2015
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:4
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Cancer cachexia (CC) is linked to poor prognosis. Although the mechanisms promoting this condition are not known, several circulating proteins have been proposed to contribute. We analyzed the plasma proteome in cancer subjects in order to identify factors associated with cachexia. Design/Subjects: Plasma was obtained from a screening cohort of 59 patients, newly diagnosed with suspected gastrointestinal cancer, with (n = 32) or without (n = 27) cachexia. Samples were subjected to proteomic profiling using 760 antibodies (targeting 698 individual proteins) from the Human Protein Atlas project. The main findings were validated in a cohort of 93 patients with verified and advanced pancreas cancer. Results: Only six proteins displayed differential plasma levels in the screening cohort. Among these, Carnosine Dipeptidase 1 (CNDP1) was confirmed by sandwich immunoassay to be lower in CC (p = 0.008). In both cohorts, low CNDP1 levels were associated with markers of poor prognosis including weight loss, malnutrition, lipid breakdown, low circulating albumin/IGF1 levels and poor quality of life. Eleven of the subjects in the discovery cohort were finally diagnosed with non-malignant disease but omitting these subjects from the analyses did not have any major influence on the results. Conclusions: In gastrointestinal cancer, reduced plasma levels of CNDP1 associate with signs of catabolism and poor outcome. These results, together with recently published data demonstrating lower circulating CNDP1 in subjects with glioblastoma and metastatic prostate cancer, suggest that CNDP1 may constitute a marker of aggressive cancer and CC.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Bryzgalova, G, et al.
(författare)
-
Mechanisms of antidiabetogenic and body weight-lowering effects of estrogen in high-fat diet-fed mice
- 2008
-
Ingår i: American journal of physiology. Endocrinology and metabolism. - : American Physiological Society. - 0193-1849 .- 1522-1555. ; 295:4, s. E904-E912
-
Tidskriftsartikel (refereegranskat)abstract
- The high-fat diet (HFD)-fed mouse is a model of obesity, impaired glucose tolerance, and insulin resistance. The main objective of this study was to elucidate the molecular mechanisms underlying the antidiabetogenic and weight-lowering effects of 17β-estradiol (E2) in this mouse model. C57BL/6 female mice (8 wk old) were fed on a HFD for 10 mo. E2, given daily (50 μg/kg sc) during the last month of feeding, decreased body weight and markedly improved glucose tolerance and insulin sensitivity. Plasma levels of insulin, leptin, resistin, and adiponectin were decreased. We demonstrated that E2treatment decreased the expression of genes encoding resistin and leptin in white adipose tissue (WAT), whereas adiponectin expression was unchanged. Furthermore, in WAT we demonstrated decreased expression levels of sterol regulatory element-binding protein 1c (SREBP1c) and its lipogenic target genes, such as fatty acid synthase and stearoyl-CoA desaturase 1 (SCD1). In the liver, the expression levels of transcription factors such as liver X receptor α and SREBP1c were not changed by E2treatment, but the expression of the key lipogenic gene SCD1 was reduced. This was accompanied by decreased hepatic triglyceride content. Importantly, E2decreased the hepatic expression of glucose-6-phosphatase (G-6-Pase). We conclude that E2treatment exerts antidiabetic and antiobesity effects in HFD mice and suggest that this is related to decreased expression of lipogenic genes in WAT and liver and suppression of hepatic expression of G-6-Pase. Decreased plasma levels of resistin probably also play an important role in this context.
|
|
| 11. |
- Correggi, M., et al.
(författare)
-
Vortex patterns in the almost-bosonic anyon gas
- 2019
-
Ingår i: Europhysics letters. - : Institute of Physics Publishing. - 0295-5075 .- 1286-4854. ; 126:2
-
Tidskriftsartikel (refereegranskat)abstract
- We study theoretically and numerically the ground state of a gas of 2D Abelian anyons in an external trapping potential. We treat anyon statistics in the magnetic gauge picture, perturbatively around the bosonic end. This leads to a mean-field energy functional, whose ground state displays vortex lattices similar to those found in rotating Bose-Einstein condensates. A crucial difference is, however, that the vortex density is proportional to the underlying matter density of the gas.
|
|
| 12. |
|
|
| 13. |
- Fransén-Pettersson, Nina, et al.
(författare)
-
A New Mouse Model That Spontaneously Develops Chronic Liver Inflammation and Fibrosis
- 2016
-
Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 11:7
-
Tidskriftsartikel (refereegranskat)abstract
- Here we characterize a new animal model that spontaneously develops chronic inflammation and fibrosis in multiple organs, the non-obese diabetic inflammation and fibrosis (N-IF) mouse. In the liver, the N-IF mouse displays inflammation and fibrosis particularly evident around portal tracts and central veins and accompanied with evidence of abnormal intrahepatic bile ducts. The extensive cellular infiltration consists mainly of macrophages, granulocytes, particularly eosinophils, and mast cells. This inflammatory syndrome is mediated by a transgenic population of natural killer T cells (NKT) induced in an immunodeficient NOD genetic background. The disease is transferrable to immunodeficient recipients, while polyclonal T cells from unaffected syngeneic donors can inhibit the disease phenotype. Because of the fibrotic component, early on-set, spontaneous nature and reproducibility, this novel mouse model provides a unique tool to gain further insight into the underlying mechanisms mediating transformation of chronic inflammation into fibrosis and to evaluate intervention protocols for treating conditions of fibrotic disorders.
|
|
| 14. |
|
|
| 15. |
|
|
| 16. |
|
|
| 17. |
- Iacopetta, B, et al.
(författare)
-
Functional categories of TP53 mutation in colorectal cancer: results of an International Collaborative Study.
- 2006
-
Ingår i: Annals of oncology : official journal of the European Society for Medical Oncology / ESMO. - : Elsevier BV. - 0923-7534. ; 17:5, s. 842-7
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Loss of TP53 function through gene mutation is a critical event in the development and progression of many tumour types including colorectal cancer (CRC). In vitro studies have found considerable heterogeneity amongst different TP53 mutants in terms of their transactivating abilities. The aim of this work was to evaluate whether TP53 mutations classified as functionally inactive (< or=20% of wildtype transactivation ability) had different prognostic and predictive values in CRC compared with mutations that retained significant activity. MATERIALS AND METHODS: TP53 mutations within a large, international database of CRC (n = 3583) were classified according to functional status for transactivation. RESULTS: Inactive TP53 mutations were found in 29% of all CRCs and were more frequent in rectal (32%) than proximal colon (22%) tumours (P < 0.001). Higher frequencies of inactive TP53 mutations were also seen in advanced stage tumours (P = 0.0003) and in tumours with the poor prognostic features of vascular (P = 0.006) and lymphatic invasion (P = 0.002). Inactive TP53 mutations were associated with significantly worse outcome only in patients with Dukes' stage D tumours (RR = 1.71, 95%CI 1.25-2.33, P < 0.001). Patients with Dukes' C stage tumours appeared to gain a survival benefit from 5-fluorouracil-based chemotherapy regardless of TP53 functional status for transactivation ability. CONCLUSIONS: Mutations that inactivate the transactivational ability of TP53 are more frequent in advanced CRC and are associated with worse prognosis in this stage of disease.
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
- Ludvigsson, JF, et al.
(författare)
-
Authors' reply to Makiyama and colleagues
- 2016
-
Ingår i: BMJ (Clinical research ed.). - : BMJ. - 1756-1833. ; 352, s. i776-
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 21. |
- Lundholm, L, et al.
(författare)
-
The estrogen receptor {alpha}-selective agonist propyl pyrazole triol improves glucose tolerance in ob/ob mice; potential molecular mechanisms
- 2008
-
Ingår i: Journal of Endocrinology. - 0022-0795 .- 1479-6805. ; 199:2, s. 275-286
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to validate the role of estrogen receptor alpha (ERalpha) signaling in the regulation of glucose metabolism, and to compare the molecular events upon treatment with the ERalpha-selective agonist propyl pyrazole triol (PPT) or 17beta-estradiol (E(2)) in ob/ob mice. Female ob/ob mice were treated with PPT, E(2) or vehicle for 7 or 30 days. Intraperitoneal glucose and insulin tolerance tests were performed, and insulin secretion was determined from isolated islets. Glucose uptake was assayed in isolated skeletal muscle and adipocytes. Gene expression profiling in the liver was performed using Affymetrix microarrays, and the expression of selected genes was studied by real-time PCR analysis. PPT and E(2) treatment improved glucose tolerance and insulin sensitivity. Fasting blood glucose levels decreased after 30 days of PPT and E(2) treatment. However, PPT and E(2) had no effect on insulin secretion from isolated islets. Basal and insulin-stimulated glucose uptake in skeletal muscle and adipose tissue were similar in PPT and vehicle-treated ob/ob mice. Hepatic lipid content was decreased after E(2) treatment. In the liver, treatment with E(2) and PPT increased and decreased the respective expression levels of the transcription factor signal transducer and activator of transcription 3, and of glucose-6-phosphatase. In summary, our data demonstrate that PPT exerts anti-diabetic effects, and these effects are mediated via ERalpha.
|
|
| 22. |
|
|
| 23. |
- Lundholm, N., et al.
(författare)
-
Induction of domoic acid production in diatoms-Types of grazers and diatoms are important
- 2018
-
Ingår i: Harmful Algae. - : Elsevier BV. - 1568-9883. ; 79, s. 64-73
-
Tidskriftsartikel (refereegranskat)abstract
- Grazers can induce toxin (domoic acid, DA) production in diatoms. The toxic response has been observed in two species of Pseudo-nitzschia and was induced by Calanus copepods. In this study, interactions between diatoms and copepods were further explored using different species of diatoms and copepods. All herbivorous copepods induced toxin production, whereas exposure to carnivorous copepods did not. In line with this, increasing the number of herbivorous copepods resulted in even higher toxin production. The induced response is thus only elicited by copepods that pose a real threat to the responding cells, which supports that the induced toxin production in diatoms evolved as an inducible defense. The cellular toxin content in Pseudo-nitzschia was positively correlated to the concentration of a group of specific polar lipids called copepodamides that are excreted by the copepods. This suggests that copepodamides are the chemical cues responsible for triggering the toxin production. Carnivorous copepods were found to produce less or no copepodamides. Among the diatoms exposed to grazing herbivorous copepods, only two of six species of Pseudo-nitzschia and none of the Nitzschia or Fragilariopsis strains responded by producing DA, indicating that not all Pseudo-nitzschia species/strains are able to produce DA, and that different diatom species might have different strategies for coping with grazing pressure. Growth rate was negatively correlated to cellular domoic acid content indicating an allocation cost associated with toxin production. Long-term grazing experiments showed higher mortality rates of grazers fed toxic diatoms, supporting the hypothesis that DA production is an induced defense mechanism.
|
|
| 24. |
|
|
| 25. |
|
|
