| 1. |
- Abd, Hadi, et al.
(author)
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Ante mortem diagnosis of amoebic encephalitis in a haematopoietic stem cell transplanted patient
- 2009
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In: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 1651-1980 .- 0036-5548. ; 41:8, s. 619-622
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Journal article (other academic/artistic)abstract
- Acanthamoeba species are widely distributed free-living amoebae showing an increased role as human pathogens causing encephalitis, keratitis, pneumonitis and dermatitis. A haematopoietic stem cell transplanted (HSCT) patient developed purulent meningitis while awaiting regrafting. The meningitis was thought to be an endogenous infection arising from the mucous membranes primarily involving the cervicofacial regions, probably due to haematogenous spread facilitated by surgery. We diagnosed a fatal case of granulomatous amoebic encephalitis caused by Acanthamoeba castellanii by direct microscopy of a cerebrospinal fluid sample (CSF), Acanthamoeba cultivation, Giemsa staining, polymerase chain reaction and sequencing.
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| 2. |
- Dlugosz, Aldona, et al.
(author)
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Chlamydia trachomatis antigens in enteroendocrine cells and macrophages of the small bowel in patients with severe irritable bowel syndrome
- 2010
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In: BMC Gastroenterology. - 1471-230X. ; 10
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Journal article (peer-reviewed)abstract
- Background: Inflammation and immune activation have repeatedly been suggested as pathogentic factors in irritable bowel syndrome (IBS). The driving force for immune activation in IBS remains unknown. The aim of our study was to find out if the obligate intracellular pathogen Chlamydia could be involved in the pathogenesis of IBS. Methods: We studied 65 patients (61 females) with IBS and 42 (29 females) healthy controls in which IBS had been excluded. Full thickness biopsies from the jejunum and mucosa biopsies from the duodenum and the jejunum were stained with a monoclonal antibody to Chlamydia lipopolysaccharide (LPS) and species-specific monoclonal antibodies to C. trachomatis and C. pneumoniae. We used polyclonal antibodies to chromogranin A, CD68, CD11c, and CD117 to identify enteroendocrine cells, macrophages, dendritic, and mast cells, respectively. Results: Chlamydia LPS was present in 89% of patients with IBS, but in only 14% of healthy controls (p < 0.001) and 79% of LPS-positive biopsies were also positive for C. trachomatis major outer membrane protein (MOMP). Staining for C. pneumoniae was negative in both patients and controls. Chlamydia LPS was detected in enteroendocrine cells of the mucosa in 90% of positive biopsies and in subepithelial macrophages in 69% of biopsies. Biopsies taken at different time points in 19 patients revealed persistence of Chlamydia LPS up to 11 years. The odds ratio for the association of Chlamydia LPS with presence of IBS (43.1; 95% CI: 13.2-140.7) is much higher than any previously described pathogenetic marker in IBS. Conclusions: We found C. trachomatis antigens in enteroendocrine cells and macrophages in the small bowel mucosa of patients with IBS. Further studies are required to clarify if the presence of such antigens has a role in the pathogenesis of IBS.
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| 3. |
- Hagstrom, Emil, et al.
(author)
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IMPACT OF BODY WEIGHT AT AGE 20 AND WEIGHT GAIN DURING ADULTHOOD ON MIDLIFE CORONARY ARTERY CALCIUM IN 15,000 MEN AND WOMEN : AN INTERIM ANALYSIS OF THE SWEDISH CARDIOPULMONARY BIOIMAGE STUDY
- 2019
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In: Journal of the American College of Cardiology. - : ELSEVIER SCIENCE INC. - 0735-1097 .- 1558-3597. ; 73:9, s. 1692-1692
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Journal article (other academic/artistic)abstract
- BackgroundElevated body weight in adolescence is strongly associated with early cardiovascular disease, but whether this association is traceable to weight in early adulthood, or to weight gain with subsequent high adult weight is not known. Using data from the Swedish CArdioPulmonary bioImage Study (SCAPIS), we investigated the association between weight at age 20, weight gain to midlife and coronary artery calcium score (CACS) at midlife.MethodsIn the first 15,810 participants in SCAPIS (mean age 58 years, 52% women), data on CACS at midlife, self-reported body weight at age 20 and weight at examination in SCAPIS were recorded.ResultsCACS in midlife was significantly higher with increasing weight at age 20 (p<0.001 for both sexes), and then increased with weight gain until midlife at all levels of body weight at age 20 after adjusting for age, height, smoking, alcohol intake, education level, exercise levels and LDL cholesterol. However, the association with weight gain was only significant in men (p = 0.047), not in women (p=0.474). No significant interaction was seen between weight at age 20 and midlife weight with CACS. The effect of weight at age 20 on CACS was significantly more marked in men than in women, as was the effect of weight gain (p<0.001 for both interactions).ConclusionWeight at age 20 and weight gain to midlife were both related to CACS, but much more markedly so in men than in women, indicating a generally larger effect of both early adult weight and further weight gain until midlife on CACS in men, compared to women.
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| 5. |
- Park, Y I, et al.
(author)
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Expression of the isiA gene is essential for the survival of the cyanobacterium Synechococcus sp PCC7942 by protecting photosystem II from excess light under iron limitation
- 1999
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In: Molecular Microbiology. - 0950-382X .- 1365-2958. ; 32:1, s. 123-129
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Journal article (peer-reviewed)abstract
- Iron deficiency is known to suppress primary productivity in both marine and freshwater ecosystems. In response to iron deficiency, certain cyanobacteria induce a chlorophyll (Chl)-protein complex, CP43 ', which is encoded by the isiA gene. The deduced amino-acid sequence of CP43 ' predicts some structural similarity to the CP43 polypeptide of photosystem II, but the function of CP43 ' remains uncertain. In order to assess its physiological role, the isiA gene of a cyanobacterium, Synechococcus sp. PCC7942, was inactivated by insertion mutagenesis (giving isiA(-) cells). Compared with isiA- cells, under iron deprivation, wild-type cells showed both lower rates of photosystem Ii-mediated O-2 evolution at limiting light irradiances and decreased yields of room temperature Chi fluorescence at various irradiances. These observations strongly suggest that the decreased photosystem II activity in wild-type cells with CP43 ' is attributable to increased non-radiative dissipation of light energy. In agreement with this hypothesis, isiA- cells were more susceptible to photoinhibition of photosynthesis than wild-type cells, resulting in much slower growth rates under iron limitation. Based on these results, we suggest that CP43' functions as a non-radiative dissipator of light energy, thus protecting photosystem II from excessive excitation under iron-deficient conditions.
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| 6. |
- Sandstrom, S, et al.
(author)
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CP43 ', the isiA gene product, functions as an excitation energy dissipator in the cyanobacterium Synechococcus sp PCC 7942
- 2001
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In: Photochemistry and Photobiology. - 0031-8655 .- 1751-1097. ; 74:3, s. 431-437
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Journal article (peer-reviewed)abstract
- Under conditions of iron deficiency certain cyanobacteria induce a chlorophyll (Chl)-binding protein, CP43 ', which is encoded by the isiA gene. We have previously suggested that CP43' functions as a nonradiative dissipator of light energy. To further substantiate its functional role an isiA overexpression construct was introduced into the genome of a cyanobacterium Synechococcus sp. PCC 7942 (giving isiA(oe) cells). The presence of functional CP43' in isiA(oe) cells was confirmed by Western blot as well as by the presence of a characteristic blueshift of the red Chi a absorption peak and a notable increase in the 77 K fluorescence peak at 685 nm. Compared to wildtype cells isiA(oe) cells, with induced CP43', had both smaller functional antenna size and decreased yields of room temperature Chi fluorescence at various light irradiances. These observations strongly suggest that isiA(oe) cells, with induced CP43', have an increased capacity for dissipating light energy as heat. In agreement with this hypothesis isiA(oe) cells were also more resistant to photoinhibition of photosynthesis than wild-type cells. Based on these results we have further strengthened the hypothesis that CP43 ' functions as a nonradiative dissipator of light energy, thus protecting photosystem II from excessive excitation under iron-deficient conditions.
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| 7. |
- Sandstrom, S, et al.
(author)
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Iron stress responses in the cyanobacterium Synechococcus sp PCC7942
- 2002
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In: Physiologia Plantarum. - 0031-9317 .- 1399-3054. ; 116:2, s. 255-263
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Journal article (peer-reviewed)abstract
- In the present study, we describe the sequential events by which the cyanobacterium Synechococcus sp. PCC 7942 adapts to iron deficiency. In doing so, we have tried to elucidate both short and long-term acclimation to low iron stress in order to understand how the photosynthetic apparatus adjusts to low iron conditions. Our results show that after an initial step, where CP43' is induced and where ferredoxin is partly replaced by flavodoxin, the photosynthetic unit starts to undergo major rearrangements. All measured components of Photosystem I (PSI), PSII and cytochrome (Cyt) i decrease relative to chlorophyll (Chl) a . The photochemical efficiencies of the two photosystems also decline during this phase of acclimation. The well-known drop in phycobilisome content measured as phycocyanin (PC)/Chl was not due to an increased degradation, but rather to a decreased rate of synthesis. The largest effects of iron deficiency were observed on PSI, the most iron-rich structure of the photosynthetic apparatus. In the light of the recent discovery of an iron deficiency induced CP43' ring around PSI a possible dual function of this protein as both an antenna and a quencher is discussed. We also describe the time course of a blue shift in the low temperature Chl emission peak around 715 nm, which originates in PSI. The shift might reflect the disassembly and/or degradation of PSI during iron deficiency and, as a consequence, PSI might under these conditions be found predominantly in a monomeric form. We suggest that the observed functional and compositional alterations represent cellular acclimation enabling growth and development under iron deficiency, and that growth ceases when the acclimation capacity is exhausted. However, the cells remain viable even after growth has ceased, since they resumed growth once iron was added back to the culture.
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