| 1. |
|
|
| 2. |
- Carrillo, M., et al.
(författare)
-
High-resolution crystal structures of transient intermediates in the phytochrome photocycle
- 2021
-
Ingår i: Structure. - : Elsevier BV. - 0969-2126. ; 29:7, s. 743-
-
Tidskriftsartikel (refereegranskat)abstract
- Phytochromes are red/far-red light photoreceptors in bacteria to plants, which elicit a variety of important physiological responses. They display a reversible photocycle between the resting Pr state and the light-activated Pfr state. Light signals are transduced as structural change through the entire protein to modulate its activity. It is unknown how the Pr-to-Pfr interconversion occurs, as the structure of intermediates remains notoriously elusive. Here, we present short-lived crystal structures of the photosensory core modules of the bacteriophytochrome from myxobacterium Stigmatella aurantiaca captured by an X-ray free electron laser 5 ns and 33 ms after light illumination of the Pr state. We observe large structural displacements of the covalently bound bilin chromophore, which trigger a bifurcated signaling pathway that extends through the entire protein. The snapshots show with atomic precision how the signal progresses from the chromophore, explaining how plants, bacteria, and fungi sense red light.
|
|
| 3. |
- Bjørnland, Kristin, et al.
(författare)
-
A Nordic multicenter survey of long-term bowel function after transanal endorectal pull-through in 200 patients with rectosigmoid Hirschsprung disease
- 2017
-
Ingår i: Journal of Pediatric Surgery. - : Elsevier BV. - 1531-5037 .- 0022-3468. ; 52:9, s. 1458-1464
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Transanal endorectal pull-through (ERPT) is the most popular technique to treat Hirschsprung disease (HD). Still, there is limited knowledge on long-term bowel function. This cross-sectional, multicenter study assessed long-term bowel function in a large HD population and examined predictors of poor outcome.METHODS: Patients older than four years or their parents filled out a validated questionnaire on bowel function. Clinical details were recorded retrospectively from medical records.RESULTS: 73/200 (37%) patients reported absolutely no impaired bowel function, meaning no constipation, fecal accidents, stoma, appendicostomy or need for enemas. Seven (4%) had a stoma, and 33 (17%) used antegrade or rectal colonic enemas. Most disarrangements of fecal control and constipation were significantly less common in older age group, but abnormal defecation frequency and social problems remained unchanged. Syndromic patients (n=31) experienced frequent fecal accidents (46%) more often than nonsyndromic (14%, P<0.001). Having a syndrome (adjusted OR 5.6, 95% CI 2.1-15, P=0.001) or a complete transanal ERPT (adjusted OR 2.4, 95% CI 1.1-5.7, P=0.038) was significantly associated with poor outcome defined as having a stoma, an appendicostomy, daily fecal accidents or need of regular rectal wash outs.CONCLUSION: A significant number of HD patients experience bowel problems many years after definite surgery. Fecal control was significantly better in older than younger HD patients, but some continued to have considerable bowel problems also as adults. A total transanal ERPT was associated with poorer outcome. Long-term follow-up of HD patients is warranted. Prognosis Study: Level II.
|
|
| 4. |
|
|
| 5. |
- Rotaru, Amelia-Elena, et al.
(författare)
-
Conductive Particles Enable Syntrophic Acetate Oxidation between Geobacter and Methanosarcina from Coastal Sediments
- 2018
-
Ingår i: mBio. - 2150-7511. ; 9:3
-
Tidskriftsartikel (refereegranskat)abstract
- Coastal sediments are rich in conductive particles, possibly affecting microbial processes for which acetate is a central intermediate. In the methanogenic zone, acetate is consumed by methanogens and/or syntrophic acetate-oxidizing (SAO) consortia. SAO consortia live under extreme thermodynamic pressure, and their survival depends on successful partnership. Here, we demonstrate that conductive particles enable the partnership between SAO bacteria (i.e., Geobacter spp.) and methanogens (Methanosarcina spp.) from the coastal sediments of the Bothnian Bay of the Baltic Sea. Baltic methanogenic sediments were rich in conductive minerals, had an apparent isotopic fractionation characteristic of CO2-reductive methanogenesis, and were inhabited by Geobacter and Methanosarcina. As long as conductive particles were delivered, Geobacter and Methanosarcina persisted, whereas exclusion of conductive particles led to the extinction of Geobacter. Baltic Geobacter did not establish a direct electric contact with Methanosarcina, necessitating conductive particles as electrical conduits. Within SAO consortia, Geobacter was an efficient [13C]acetate utilizer, accounting for 82% of the assimilation and 27% of the breakdown of acetate. Geobacter benefits from the association with the methanogen, because in the absence of an electron acceptor it can use Methanosarcina as a terminal electron sink. Consequently, inhibition of methanogenesis constrained the SAO activity of Geobacter as well. A potential benefit for Methanosarcina partnering with Geobacter is that together they competitively exclude acetoclastic methanogens like Methanothrix from an environment rich in conductive particles. Conductive particle-mediated SAO could explain the abundance of acetate oxidizers like Geobacter in the methanogenic zone of sediments where no electron acceptors other than CO2 are available.IMPORTANCE Acetate-oxidizing bacteria are known to thrive in mutualistic consortia in which H2 or formate is shuttled to a methane-producing Archaea partner. Here, we discovered that such bacteria could instead transfer electrons via conductive minerals. Mineral SAO (syntrophic acetate oxidation) could be a vital pathway for CO2-reductive methanogenesis in the environment, especially in sediments rich in conductive minerals. Mineral-facilitated SAO is therefore of potential importance for both iron and methane cycles in sediments and soils. Additionally, our observations imply that agricultural runoff or amendments with conductive chars could trigger a significant increase in methane emissions.
|
|
| 6. |
- Shaheen, H. I., et al.
(författare)
-
Phenotypic profiles of enterotoxigenic Escherichia coli associated with early childhood diarrhea in rural Egypt
- 2004
-
Ingår i: J Clin Microbiol. ; 42:12, s. 5588-95
-
Tidskriftsartikel (refereegranskat)abstract
- Enterotoxigenic Escherichia coli (ETEC) causes substantial diarrheal morbidity and mortality in young children in countries with limited resources. We determined the phenotypic profiles of 915 ETEC diarrheal isolates derived from Egyptian children under 3 years of age who participated in a 3-year population-based study. For each strain, we ascertained enterotoxin and colonization factor (CF) expression, the O:H serotype, and antimicrobial susceptibility. Sixty-one percent of the strains expressed heat-stable enterotoxin (ST) only, 26% expressed heat-labile enterotoxin (LT) alone, and 12% expressed both toxins. The most common CF phenotypes were colonization factor antigen I (CFA/I) (10%), coli surface antigen 6 (CS6) (9%), CS14 (6%), and CS1 plus CS3 (4%). Fifty-nine percent of the strains did not express any of the 12 CFs included in our test panel. Resistance of ETEC strains to ampicillin (63%), trimethoprim-sulfamethoxazole (52%), and tetracycline (43%) was common, while resistance to quinolone antibiotics was rarely detected. As for the distribution of observed serotypes, there was an unusually wide diversity of O antigens and H types represented among the 915 ETEC strains. The most commonly recognized composite ETEC phenotypes were ST CS14 O78:H18 (4%), ST (or LTST) CFA/I O128:H12 (3%), ST CS1+CS3 O6:H16 (2%), and ST CFA/I O153:H45 (1.5%). Temporal plots of diarrheal episodes associated with ETEC strains bearing common composite phenotypes were consistent with discrete community outbreaks either within a single or over successive warm seasons. These data suggest that a proportion of the disease that is endemic to young children in rural Egypt represents the confluence of small epidemics by clonally related ETEC strains that are transiently introduced or that persist in a community reservoir.
|
|
| 7. |
- Yadav, Manisha, et al.
(författare)
-
Cysteine proteinase 30 (CP30) and antibody response to CP30 in serum and vaginal washes of symptomatic and asymptomatic Trichomonas vaginalis-infected women
- 2007
-
Ingår i: Parasite Immunology. - : Wiley. - 1365-3024 .- 0141-9838. ; 29:7, s. 359-365
-
Tidskriftsartikel (refereegranskat)abstract
- Infection with Trichomonas vaginalis may be asymptomatic or with symptoms suggestive of vaginitis. Because cysteine proteinase 30 (CP30) of T. vaginalis is known to be a virulence marker that plays a role in cytoadherence, the aim of this study was to analyse the presence of CP30 and antibody to CP30 in clinical samples of symptomatic and asymptomatic infected women. CP30 was detected in all the serum and vaginal washes (VWs) of symptomatic women and in 65% of the serum and 80% of the VWs of asymptomatic women. This suggested that the majority of asymptomatic women also exhibit CP30 in the serum and VWs. Antibody to CP30 was detected in all the serum samples of symptomatic and asymptomatic women and in the VWs of only 54.5% of the symptomatic and 35% of the asymptomatic women. Antibody to CP30 was also detected in 3/20 of the serum samples and in none of the VWs from uninfected women. Significantly higher amounts of antibody (mean OD values) were observed in serum and VWs of symptomatic as compared to asymptomatic and healthy women (P<0.001). These results indicate that besides CP30, other factors may also be playing a role in leading to symptomatic infection, because CP30 was detected in clinical samples from all the symptomatic and the majority of the asymptomatic women. Although anti-CP30 antibodies do not appear to be protective, detection of antibody to CP30 antigen in serum samples may be used as a diagnostic tool.
|
|
| 8. |
- Yadav, Manisha, et al.
(författare)
-
Nitric oxide radicals in leucocytes and vaginal washes of Trichomonas vaginalis -infected symptomatic and asymptomatic women
- 2006
-
Ingår i: Parasitology. - 1469-8161. ; 132:Pt 3, s. 339-343
-
Tidskriftsartikel (refereegranskat)abstract
- The clinical spectrum of Trichomonas vaginalis infection varies from asymptomatic to mild, moderate or severe vaginitis. Nitric oxide and other reactive nitrogen radicals produced by immune effector cells are important cytotoxic and cytostatic mediators against several microorganisms including parasites. In the present study, inducible nitric oxide synthase (iNOS) and reactive nitrogen intermediates (RNI) were determined in leucocyte cultures (stimulated with T. vaginalis in vitro) and vaginal washes (VWs) of 22 symptomatic and 20 asymptomatic T. vaginalis-infected and 20 healthy women by immunoblotting and Griess method respectively. The iNOS protein was detected in leucocytes and VWs of all the symptomatic and asymptomatic women, but was not detected in any of the samples from healthy women. Mean iNOS protein band intensity was significantly higher in leucocytes as compared to VWs (P<0.001) of both symptomatic and asymptomatic women and was also higher in leucocytes of asymptomatic as compared to symptomatic women (P<0.05). Mean RNI concentration was also significantly higher in leucocytes (P<0.01) and VWs (P<0.05) of asymptomatic as compared to symptomatic women, and was also higher in samples of infected as compared to healthy women (P<0.001). These results suggest that reactive nitrogen radicals may have a role in limiting T. vaginalis infection in asymptomatic women.
|
|
