| 1. |
- Hedberg, Maria E., et al.
(författare)
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Prevotella jejuni sp. nov., isolated from the small intestine of a child with celiac disease.
- 2013
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Ingår i: International journal of systematic and evolutionary microbiology. - : Microbiology Society. - 1466-5034 .- 1466-5026. ; 63:11, s. 4218-4223
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Tidskriftsartikel (refereegranskat)abstract
- Five obligately anaerobic, Gram-negative, saccharolytic and proteolytic, non-spore-forming bacilli (CD3:27, CD3:28T, CD3:33, CD3:32 and CD3:34) are described. All five strains were isolated from the small intestine of a female child with celiac disease. The cells of the five strains were observed to be short rods or coccoid cells with longer filamentous forms seen sporadically. The organisms produced acetic acid and succinic acid as major metabolic end products. Phylogenetic analysis, based on comparative 16S rRNA gene sequence analysis revealed close relationships between CD3:27, CD3:28T and CD3:33 on one hand, between CD3:32 and P. histicola CCUG 55407T and between CD3:34 and P. melaninogenica CCUG 4944BT on the other. The strains CD3:27, CD3:28T and CD3:33 were clearly different from any other species within the genus Prevotella and most closely related to but distinct from P. melaninogenica. Based on 16S rRNA gene, RNA polymerase β-subunit gene and 60-kDa chaperonin protein subunit gene sequencing, phenotypic, chemical and biochemical properties strains CD3:27, CD3:28T and CD3:33 have been determined to represent a novel species within the genus Prevotella, named Prevotella jejuni sp. nov. Strain CD3:28T (CCUG 60371T = DSM 26989T) is the type strain of the proposed new species. All five strains were able to form homologous aggregates, in which tube-like structures were connecting individual bacteria cells. The five strains were able to bind to human intestinal carcinoma cell lines at 37 °C.
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| 2. |
- Israelsson, Olle
(författare)
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Chlamydial symbionts in the enigmatic Xenoturbella (Deuterostomia)
- 2007
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Ingår i: Journal of Invertebrate Pathology. - : Elsevier BV. - 0022-2011 .- 1096-0805. ; 96:3, s. 213-220
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Tidskriftsartikel (refereegranskat)abstract
- Ultrastructural observations of the gastrodermal cells in the enigmatic Xenoturbella revealed numerous chlamydiae. They are related to "Candidatus Fritschea" and Simkania (Simkaniaceae) based oil 16S and 23S rRNA. Their 23S rRNA gene contains an intron encoding a putative homing endonuclease. The chlamydiae were pleornorphic and formed intravacuolar colonies. They have flattened disk-shaped elementary bodies, either oval or bow tie-shaped in cross-section, and reticulate bodies that are spherical, polygonal or irregularly shaped. All stages have five-layered cell wall with rippled appearance. Bacteria were not observed in the nuclei. The association between the chlamydiae and Xenoturbella is characterized by absence of cytopathological effects; limited host cell response against the chlamydiae; the confinement of the chlamydiae to inclusions in some part of the host cell; and complete and uniform infection of all examined hosts.
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| 3. |
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| 4. |
- Israelsson, Olle
(författare)
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Observations on some unusual cell types in the enigmatic worm Xenoturbella (phylum uncertain)
- 2006
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Ingår i: Tissue & Cell. - : Elsevier BV. - 0040-8166 .- 1532-3072. ; 38:4, s. 233-242
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Tidskriftsartikel (refereegranskat)abstract
- The inner epithelially organized gastrodermis of the enigmatic simple worms of the genus Xenoturbella contains numerous partly phagocytized cells of two kinds, ciliated cells (PCCs) and muscle cells (PMCs). PCCs and PMCs have features of undifferentiated cells and do not derive from differentiated adult cells. Homology of phagocytized cells to pulsatile bodies in acoel and nemertodermatid flatworms is therefore rejected. The phagocytized cells might represent an hitherto unknown process of regeneration in Xenoturbella. The phagocytized material contains as much DNA as in all mitochondria and nuclei of the living cells. This is probably caused by lack of digestion of nucleic acids. The genome size of Xenoturbella bocki was determined. It has a C-value of about 0.55 pg.
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| 5. |
- Israelsson, Olle
(författare)
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Ultrastructural aspects of the 'statocyst' of Xenoturbella (Deuterostomia) cast doubt on its function as a georeceptor
- 2007
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Ingår i: Tissue & Cell. - : Elsevier BV. - 0040-8166 .- 1532-3072. ; 39:3, s. 171-177
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Tidskriftsartikel (refereegranskat)abstract
- The "statocyst" in the enigmatic worm Xenoturbella is a structure containing motile flagellated cells. It is situated inside the subepidermal membrane complex (between epidermis and muscular layers) in the anterior end of the body. The motile cells contain a lipophilic retractile body ("statolith"). and a series of vesicles from small dense core vesicles presumably formed from the retractile body to large vesicles with dense aggregates of filamentous tubules that become exocytized through secretion. It is unlikely that the statocyst is a georeceptor (true statocyst); maybe it has an endocrine function.
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| 6. |
- Israelsson, Olle, 1967-
(författare)
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Xenoturbella
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Israelsson, Olle
(författare)
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Xenoturbella (Deuterostomia) probably feeds on dissolved organic matter
- 2008
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Ingår i: Marine Biology Research. - : Informa UK Limited. - 1745-1000 .- 1745-1019. ; 4:5, s. 384-391
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Tidskriftsartikel (refereegranskat)abstract
- The enigmatic deuterostome Xenoturbella does ubiquitously contain exogenous nucleic acids. This has been used in several papers as proof of selective feeding by Xenoturbella on nuculid bivalves. However, their feeding biology is unknown and exogenous nucleic acids might not originate from their main nutrient source. I have examined the possible pathways of nutrient uptake. The animals neither took up cells nor dissolved dyes through the 'mouth'. Instead, they possessed extensive pinocytosis through the epidermis. Therefore, it is probable that the main source of nutrients is dissolved organic matter uptaken through the epidermis. This does not exclude that phagocytosis in the gastrodermis does occur, e.g. due to direct expose of the gastrodermis during asexual reproduction. The ubiquitously present exogenous nucleic acids in Xenoturbella probably do originate from such events and not from their main food source.
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| 8. |
- Magnusson, Martin, et al.
(författare)
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Brain natriuretic peptide is related to diastolic dysfunction whereas urinary albumin excretion rate is related to left ventricular mass in asymptomatic type 2 diabetes patients
- 2010
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Ingår i: Cardiovascular Diabetology. - : Springer Science and Business Media LLC. - 1475-2840. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Background: The aims of this study were to estimate the prevalence of left ventricular systolic (LVSD) and diastolic (LVDD) dysfunction, and to test if BNP and urinary albumin excretion rate (AER) are related to LVSD, LVD and left ventricular mass (LVM) in asymptomatic type 2 diabetes patients. Methods: Presence of LVSD, LVDD and LVM, determined with echocardiography, was related to levels of BNP and AER in 153 consecutive asymptomatic patients with type 2 diabetes. Results: LVSD was present in 6.1% of patients whereas 49% (29% mild, 19% moderate and 0.7% severe) had LVDD and 9.4% had left ventricular hypertrophy. Increasing age (P < 0.0001) was the only independent variable related to mild LVDD whereas increasing BNP (P = 0.01), systolic blood pressure (P = 0.01), age (P = 0.003) and female gender (P = 0.04) were independent determinants of moderate to severe LVDD. AER (P = 0.003), age (P = 0.01) and male gender (P = 0.006) were directly and independently related to LVM. Conclusion: About half of asymptomatic type 2 diabetes patients have LVDD. Of those, more than one third display moderate LVDD pattern paralleled by increases in BNP, suggesting markedly increased risk of heart failure, especially in females, whereas AER and male sex are related to LVM.
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| 9. |
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| 10. |
- Perseke, Marleen, et al.
(författare)
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The mitochondrial DNA of Xenoturbella bocki : genomic architecture and phylogenetic analysis
- 2007
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Ingår i: Theory in biosciences. - : Springer Science and Business Media LLC. - 1431-7613 .- 1611-7530. ; 126:1, s. 35-42
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Tidskriftsartikel (refereegranskat)abstract
- The phylogenetic position of Xenoturbella bocki has been a matter of controversy since its description in 1949. We sequenced a second complete mitochondrial genome of this species and performed phylogenetic analyses based on the amino acid sequences of all 13 mitochondrial protein-coding genes and on its gene order. Our results confirm the deuterostome relationship of Xenoturbella. However, in contrast to a recently published study (Bourlat et al. in Nature 444: 85-88, 2006), our data analysis suggests a more basal branching of Xenoturbella within the deuterostomes, rather than a sister-group relationship to the Ambulacraria (Hemichordata and Echinodermata).
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