| 1. |
- Aziz, Emad F., et al.
(author)
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Photoinduced formation of N-2 molecules in ammonium compounds
- 2007
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In: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 111:39, s. 9662-9669
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Journal article (peer-reviewed)abstract
- Via fluorescence yield (FY) and resonant inelastic scattering spectroscopy in the soft X-ray range we find that soft X-rays induce formation of N-2 molecules in solid NH4Cl and in related compounds. The nitrogen molecules form weak bonds in NH4Cl, so that a substantial fraction of the molecules remains in the sample. From measurements of the FY as a function of exposure and temperature, the rates for the photochemical processes are estimated. At elevated temperatures (363 K), several nitrogen atoms are removed from the sample per incoming photon. At lower temperatures (233 K), the rate is reduced to around 0.02 nitrogen atoms for each incoming photon. Virtually all these atoms form N-2 molecules which are bound in the sample. The generality and implications of these results are briefly discussed.
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| 2. |
- Avdic, H. B., et al.
(author)
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Reduced effects of social feedback on learning in Turner syndrome
- 2023
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In: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13:1
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Journal article (peer-reviewed)abstract
- Turner syndrome is a genetic condition caused by a complete or partial loss of one of the X chromosomes. Previous studies indicate that Turner syndrome is associated with challenges in social skills, but the underlying mechanisms remain largely unexplored. A possible mechanism is a reduced social influence on learning. The current study examined the impact of social and non-social feedback on learning in women with Turner syndrome (n=35) and a sex- and age-matched control group (n=37). Participants were instructed to earn points by repeatedly choosing between two stimuli with unequal probabilities of resulting in a reward. Mastering the task therefore required participants to learn through feedback which of the two stimuli was more likely to be rewarded. Data were analyzed using computational modeling and analyses of choice behavior. Social feedback led to a more explorative choice behavior in the control group, resulting in reduced learning compared to non-social feedback. No effects of social feedback on learning were found in Turner syndrome. The current study thus indicates that women with Turner syndrome may be less sensitive to social influences on reinforcement learning, than the general population.
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| 3. |
- Forsberg, Johan, et al.
(author)
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Angular anisotropy in resonant inelastic soft X-ray scattering of liquid water
- 2009
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In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 79:13, s. 132203-
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Journal article (peer-reviewed)abstract
- Resonantly excited soft x-ray emission spectra of liquid water have been measured at two different angles relative to the polarization direction of the exciting radiation. The results demonstrate that the emission is much more isotropic than expected for the free water molecule but that the trends in the remaining anisotropy qualitatively agree. It is found that the two sharp oxygen peaks at high emission energy correspond to states of different symmetry.
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| 4. |
- Gråsjö, Johan, et al.
(author)
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Electronic structure of water molecules confined in a micelle lattice
- 2009
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In: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 113:24, s. 8201-8205
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Journal article (peer-reviewed)abstract
- Oxygen K absorption and emission spectra of water molecules confined in dodecyltrimethyl ammonium chloride micelle structures are presented. The local electronic structure of the water molecules is found to be dramatically different from the electronic structure of water molecules in the gas-phase as well as in liquid water. Hybridization with states of the ions in the surrounding ions is directly observed, and evidence for stabilization of the water molecules relative to molecules in bulk water is found.
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| 5. |
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| 6. |
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| 7. |
- Agåker, Marcus, et al.
(author)
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Spectroscopy in the vacuum-ultraviolet
- 2011
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In: Nature Photonics. - : Springer Science and Business Media LLC. - 1749-4885 .- 1749-4893. ; 5:5, s. 248-248
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Journal article (peer-reviewed)
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| 8. |
- Akhoondi, Shahab, et al.
(author)
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FBXW7/hCDC4 is a general tumor suppressor in human cancer
- 2007
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In: Cancer Research. - 0008-5472 .- 1538-7445. ; 67:19, s. 9006-9012
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Journal article (peer-reviewed)abstract
- The ubiquitin-proteasome system is a major regulatory pathway of protein degradation and plays an important role in cellular division. Fbxw7 (or hCdc4), a member of the F-box family of proteins, which are substrate recognition components of the multisubunit ubiquitin ligase SCF (Skpl-Cdc53/ Cullin-F-box-protein), has been shown to mediate the ubiquitin-dependent proteolysis of several oncoproteins including cyclin El, c-Myc, c-Jun, and Notch. The oncogenic potential of Fbxw7 substrates, frequent allelic loss in human cancers, and demonstration that mutation of FBXW7 cooperates with p53 in mouse tumorigenesis have suggested that Fbxw7 could function as a tumor suppressor in human cancer. Here, we carry out an extensive genetic screen of primary tumors to evaluate the role of FBXW7 as a tumor suppressor in human tumorigenesis. Our results indicate that FBXW7 is inactivated by mutation in diverse human cancer types with an overall mutation frequency of ∼ 6%. The highest mutation frequencies were found in tumors of the bile duct (cholangio-carcinomas, 35%), blood (T-cell acute lymphocytic leukemia, 31%), endometrium (9%), colon (9%), and stomach (6%). Approximately 43% of all mutations occur at two mutational "hotspots," which alter Arg residues (Arg465 and Arg479) that are critical for substrate recognition. Furthermore, we show that Fbxw7Arg465 hotspot mutant can abrogate wild-type Fbxw7 function through a dominant negative mechanism. Our study is the first comprehensive screen of FBXW7 mutations in various human malignancies and shows that FBXW7 is a general tumor suppressor in human cancer.
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| 9. |
- Andreasson, Eskil, et al.
(author)
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Integrating Moldflow and Abaqus in the Package Simulation Workflow
- 2013
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Conference paper (peer-reviewed)abstract
- Tetra Pak has used numerical simulation tools for plastic injection molding (Moldflow) and structural analysis (Abaqus/Implicit and Abaqus/Explicit) for many years. Today these two simulation tools are used independently of each other without any coupling. How these two disciplines can be combined to better predict the mechanical response of a polymer component is presented in this work. The manufacturing process, in this case injection molding, creates the mechanical properties of the produced polymer part. Process settings, material selection and molding tool geometry affect the polymer flow, material orientation and rate of crystallinity. A method to build a layered finite element model in Abaqus using results from Moldflow simulations regarding crystallinity growth and molecular orientation is proposed. Relatively simple material models were utilized and assigned for each individual material layer through the thickness in the polymer part. These constitutive models were derived phenomenologically from experimental test results and could adequately capture both the microscopic and the macroscopic behavior in a more realistic way. The numerical results showed a good agreement with the experimental results, both regarding visual appearance and force/displacement response.
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| 10. |
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| 11. |
- Barbe, Laure, et al.
(author)
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Histo-blood group antigen-binding specificities of human rotaviruses are associated with gastroenteritis but not with in vitro infection
- 2018
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In: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 8
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Journal article (peer-reviewed)abstract
- Human strains of rotavirus A (RVAs) recognize fucosylated glycans belonging to histo-blood group antigens (HBGAs) through their spike protein VP8*. Lack of these ligands due to genetic polymorphisms is associated with resistance to gastroenteritis caused by P[8] genotype RVAs. With the aim to delineate the contribution of HBGAs in the process, we analyzed the glycan specificity of VP8* proteins from various P genotypes. Binding to saliva of VP8* from P[8] and P[4] genotypes required expression of both FUT2 and FUT3 enzymes, whilst binding of VP8* from the P[14] genotype required FUT2 and A enzymes. We further defined a glycan motif, GlcNAc beta 3Gal beta 4GlcNAc, recognized by P[6] clinical strains. Conversion into Lewis antigens by the FUT3 enzyme impaired recognition, explaining their lower binding to saliva of Lewis positive phenotype. In addition, the presence of neutralizing antibodies was associated with the presence of the FUT2 wild type allele in sera from young healthy adults. Nonetheless, in vitro infection of transformed cell lines was independent of HBGAs expression, indicating that HBGAs are not human RV receptors. The match between results from saliva-based binding assays and the epidemiological data indicates that the polymorphism of human HBGAs controls susceptibility to RVAs, although the exact mechanism remains unclear.
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| 12. |
- Baroni de Moraes, Marcia Terezinha, et al.
(author)
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Phenotyping of Lewis and secretor HBGA from saliva and detection of new FUT2 gene SNPs from young children from the Amazon presenting acute gastroenteritis and respiratory infection
- 2019
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In: Infection, Genetics and Evolution. - : ELSEVIER SCIENCE BV. - 1567-1348 .- 1567-7257. ; 70, s. 61-66
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Journal article (peer-reviewed)abstract
- The Histo-blood group antigens (HBGA) are host genetic factors associated with susceptibility to rotavirus (RV) and human norovirus (HuNoV), the major etiological agents of viral acute gastroenteritis (AGE) worldwide. The FUT2 gene expressing the alpha-1, 2-L- fucosyltransferase enzyme is important for gut HBGA expression, and also provides a composition of the phenotypic profile achieved through mutations occurring in populations with different evolutionary histories; as such, it can be considered a genetic population marker. In this study, Lewis and secretor HBGA phenotyping was performed using 352 saliva samples collected from children between three months and five years old born in the Amazon (Brazil, Venezuela and English Guyana) presenting AGE or acute respiratory infection (ARI), the latter considered as control samples. The total of children phenotyped as secretors was 323, corresponding to 91.80%. From these, 207 (58.80%) had a Le (a + b +) profile. The HBGA profiles were equally found in children with AGE as well as with ARI. The rs1047781 of the FUT2 gene was not detected in DNA from saliva cells with a Le (a + b +) profile. However, mutations not yet described in the FUT2 gene were observed: missense 325A amp;gt; T, 501C amp;gt; T, 585C amp;gt; T, 855A amp;gt; T and missense substitutions 327C amp;gt; T [S (Ser) amp;gt; C (Cys)], 446 T amp;gt; C [L(Leu) amp;gt; P(Pro)], 723C amp;gt; A [N(Asn) amp;gt; K(Lys)], 724A amp;gt; T [I(Ile) amp;gt; F(Phe)], 736C amp;gt; A [H(His) amp;gt; N(Asn)]. The SNP distribution in the FUT2 gene of the analyzed samples was very similar to that described in Asian populations, including indigenous tribes.
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| 13. |
- Becker-Dreps, Sylvia, et al.
(author)
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Etiology of Childhood Diarrhea After Rotavirus Vaccine Introduction A Prospective, Population-based Study in Nicaragua
- 2014
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In: The Pediatric Infectious Disease Journal. - : Lippincott, Williams andamp; Wilkins. - 0891-3668 .- 1532-0987. ; 33:11, s. 1156-1163
-
Journal article (peer-reviewed)abstract
- Background: Nicaragua was the first developing nation to implement routine immunization with the pentavalent rotavirus vaccine (RV5). In this RV5-immunized population, understanding infectious etiologies of childhood diarrhea is necessary to direct diarrhea treatment and prevention efforts. Methods: We followed a population-based sample of children less than5 years in Leon, Nicaragua for diarrhea episodes through household visits. Information was obtained on RV5 history and sociodemographics. Stool samples collected during diarrhea episodes and among healthy children underwent laboratory analysis for viral, bacterial and parasitic enteropathogens. Detection frequency and incidence of each enteropathogen was calculated. Results: The 826 children in the cohort experienced 677 diarrhea episodes during 607.5 child-years of exposure time (1.1 episodes per child-year). At least 1 enteropathogen was detected among 61.1% of the 337 diarrheal stools collected. The most common enteropathogens among diarrheal stools were: norovirus (20.4%), sapovirus (16.6%), enteropathogenic Escherichia coli (11.3%), Entamoeba histolytica/dispar (8.3%), Giardia lamblia (8.0%) and enterotoxigenic E. coli (7.7%), with rotavirus detected among 5.3% of diarrheal stools. Enteropathogenic Escherichia coli and enterotoxigenic E. coli were frequently detected among stools from healthy children. Among children with diarrhea, norovirus was more commonly detected among younger children (less than2 years) and G. lamblia was more commonly detected among older children (2-4 years). The mean age of rotavirus detection was 34.6 months. Conclusions: In this Central American community after RV5 introduction, rotavirus was not commonly detected among children with diarrhea. Prevention and appropriate management of norovirus and sapovirus should be considered to further reduce the burden of diarrheal disease.
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| 14. |
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| 15. |
- Bialowas, Sonja, et al.
(author)
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Intracellularly expressed rotavirus NSP4 stimulates release of serotonin (5-HT) from human enterochromaffin cells
-
Other publication (other academic/artistic)abstract
- Rotavirus (RV) is associated with diarrhoea and vomiting, but the mechanisms behind these symptoms remain unresolved. While RV have been shown to infect and stimulate secretion of serotonin (5-hydroxytryptamine; 5-HT) from human enterochromaffin (EC) cells and to infect EC cells in the small intestine of mice, it remains to identify which intracellularly expressed viral protein (VP) being responsible for this novel property.To address this issue, human EC cells were transfected with small interfering RNA (siRNA) targeting the structural (VP4, VP6 and VP7) and the non-structural protein 4 (NSP4) followed by infection with Rhesus rotavirus (RRV). siRNA specific to NSP4 (siRNANSP4) significantly attenuated secretion of 5-HT compared to siRNAVP4, siRNAVP6 , siRNAVP7 and non-targeting (Nt) siRNAnt. Intracellular calcium clamping with BABTA/AM showed that intracellularly expressed NSP4-stimulated secretion of 5-HT from EC cells was calcium-dependent. Furthermore RV down-regulated the 5-HT transporter (SERT) mRNA in ileum but not tryptophan hydroxylase 1 (TPH1) mRNA the rate-limiting enzyme for 5-HT synthesis. The unaffected expression of TPH1 mRNA in the intestinal segments suggests that release of 5- HT primarily originates from pre-made 5-HT rather than from newly synthesised 5-HT mRNA. Moreover, down-regulation of SERT mRNA in ileum presumably resulted in reduced re- uptake of 5-HT by SERT to EC cells and thus increased extracellular 5-HT in the small intestine. Moreover, 7/7 infant mice responded following intraperitoneal administration of 5-HT with rapid (<30 min) diarrhoea in dose-dependent manner. In the light of these results and the fact that both 5-HT and NSP4 can induce diarrhoea in mice, a disease mechanism to RV diarrhoea is proposed.
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| 16. |
- Bialowas, Sonja, et al.
(author)
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Rotavirus and Serotonin Cross-Talk in Diarrhoea
- 2016
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In: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 11:7, s. e0159660-
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Journal article (peer-reviewed)abstract
- Rotavirus (RV) has been shown to infect and stimulate secretion of serotonin from human enterochromaffin (EC) cells and to infect EC cells in the small intestine of mice. It remains to identify which intracellularly expressed viral protein(s) is responsible for this novel property and to further establish the clinical role of serotonin in RV infection. First, we found that siRNA specifically silencing NSP4 (siRNA(NSP4)) significantly attenuated secretion of serotonin from Rhesus rotavirus (RRV) infected EC tumor cells compared to siRNA(VP4), siRNA(VP6) and siRNA(VP7). Second, intracellular calcium mobilization and diarrhoeal capacity from virulent and avirulent porcine viruses correlated with the capacity to release serotonin from EC tumor cells. Third, following administration of serotonin, all (10/10) infants, but no (0/8) adult mice, responded with diarrhoea. Finally, blocking of serotonin receptors using Ondansetron significantly attenuated murine RV (strain EDIM) diarrhoea in infant mice (2.9 vs 4.5 days). Ondansetron-treated mice (n = 11) had significantly (p amp;lt; 0.05) less diarrhoea, lower diarrhoea severity score and lower total diarrhoea output as compared to mock-treated mice (n = 9). Similarly, Ondansetron-treated mice had better weight gain than mock-treated animals (p amp;lt; 0.05). A most surprising finding was that the serotonin receptor antagonist significantly (p amp;lt; 0.05) also attenuated total viral shedding. In summary, we show that intracellularly expressed NSP4 stimulates release of serotonin from human EC tumor cells and that serotonin participates in RV diarrhoea, which can be attenuated by Ondansetron.
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| 17. |
- Bjureberg, Johan, et al.
(author)
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Targeting Maladaptive Anger With Brief Therapist-Supported Internet-Delivered Emotion Regulation Treatments : A Randomized Controlled Trial
- 2023
-
In: Journal of Consulting and Clinical Psychology. - : American Psychological Association Press. - 0022-006X .- 1939-2117. ; 91:5, s. 254-266
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Journal article (peer-reviewed)abstract
- Objective: To evaluate the relative impact of three brief therapist-supported internet-delivered emotion regulation treatments for maladaptive anger (mindful emotion awareness [MEA], cognitive reappraisal [CR], and mindful emotion awareness + cognitive reappraisal [MEA + CR]) and to test whether baseline levels of anger pathology moderate treatment outcome.Method: Treatments were evaluated in a randomized controlled trial. In total, 234 participants (59% female; mean age = 41.1, SD = 11.6) with maladaptive anger were randomized to MEA (n = 78), CR (n = 77), or MEA + CR (n = 79). Self-reported primary and secondary outcomes were followed up at primary endpoint, 3 months after treatment termination (88% retention). Primary outcomes were also assessed weekly during a prolonged baseline phase (4 weeks) and an active treatment phase (4 weeks).Results: At the primary endpoint, the MEA + CR was superior in terms of anger expression (d = 0.27 95% confidence interval, CI [0.03, 0.51]), aggression (d = 0.43 [0.18, 0.68]), and anger rumination (d = 0.41 [0.18, 0.63]). MEA + CR was particularly effective in reducing anger expression (d = 0.66 [0.21, 1.11]), aggression (d = 0.90 [0.42, 1.39]), and anger rumination (d = 0.80 [0.40, 1.20]) for individuals who reported high values (+1SD) of the outcomes at baseline.Conclusions: Brief therapist-supported internet-delivered MEA and CR treatments are effective interventions for maladaptive anger. Combining MEA and CR is especially effective in reducing anger expression and aggression, particularly, in individuals who report higher levels of initial anger pathology. The present study highlights the importance of emotion regulation as an important treatment target for reducing maladaptive anger.
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| 18. |
- Bonkoungou, Isidore Juste O., et al.
(author)
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Rotavirus and norovirus in children with severe diarrhea in Burkina Faso before rotavirus vaccine introduction
- 2018
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In: Journal of Medical Virology. - : WILEY. - 0146-6615 .- 1096-9071. ; 90:9, s. 1453-1460
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Journal article (peer-reviewed)abstract
- Burkina Faso introduced rotavirus vaccine (RotaTeq) to the national immunization program in November 2013. This study describes the detection rates, clinical profiles, and molecular epidemiology of rotavirus and norovirus (NoV) infections among children amp;lt;5 years hospitalized (n=154) because of acute diarrhea in Ouagadougou, Burkina Faso, from December 2012 to November 2013, just before the start of vaccination. Overall, 44% and 23% of fecal samples were positive for rotavirus and NoV, respectively, most of them detected during the cold dry season (December-March). The predominant G/P combinations were G12P[8] (47%) and G6P[6] (30%). G2P[4] (n=3), G12P[6] (n=3), and G6P[8] (n=1) werealso detected. Nearly all (94%) successfully genotyped NoV strains belonged to genotype GII.4. The predominance of rotavirus and NoV was noteworthy in the age group 6 months, with 67% rotavirus and 22% NoV, respectively. Vomiting was significantly more common among rotavirus-infected children. To conclude, this study shows high detection rates of both rotavirus and NoV in children with severe diarrhea in Burkina Faso just before the introduction of rotavirus group A vaccination. The results can be used for estimating the impact of rotavirus group A vaccination, which started in the end of 2013. Furthermore, this study shows that the G6P[6] rotavirus strains emerging in Burkina Faso in 2010 is now established as a regionally important genotype.
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| 19. |
- Boström, Hans, et al.
(author)
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U-2973, a novel B-cell line established from a patient with a mature B-cell leukemia displaying concurrent t(14;18) and MYC translocation to a non-IG gene partner
- 2008
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In: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 81:3, s. 218-225
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Journal article (peer-reviewed)abstract
- B-cell lymphomas/leukemias with simultaneous t(14;18)(q32;q21) and MYC rearrangements have recently been shown to constitute a separate diagnostic entity, presenting with a rapid clinical course and a very poor prognosis. We describe the establishment of an Epstein-Barr virus negative cell line, designated U-2973, from a male patient with a de novo aggressive B-cell lymphoma/leukemia and very high peripheral blast cell count. Flow cytometry of bone marrow cells and U-2973 displayed a mature B-cell phenotype, and immunostaining showed expression of MYC and BCL2. IG gene rearrangement data were consistent with a lymphoid neoplasm of germinal centre derivation. Cytogenetic studies using conventional G-banding, fluorescent in situ hybridization, spectral karyotyping and single nucleotide polymorphism array demonstrated a complex karyotype with both a t(14;18) and double translocations between MYC and a non-IG gene partner located at chromosome 12p12.1.
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| 20. |
- Bucardo, Filemón, et al.
(author)
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Association of Genetic Polymorphisms in DC-SIGN, Toll-Like Receptor 3, and Tumor Necrosis Factor a Genes and the Lewis-Negative Phenotype With Chikungunya Infection and Disease in Nicaragua
- 2021
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In: Journal of Infectious Diseases. - : Oxford University Press. - 0022-1899 .- 1537-6613. ; 223:2, s. 278-286
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Journal article (peer-reviewed)abstract
- BackgroundChikungunya infections range from subclinical infection to debilitating arthralgia and to chronic inflammatory rheumatism. Tumor necrosis factor (TNF) α, DC-SIGN (dendritic cell–specific intercellular adhesion molecule 3–grabbing nonintegrin), Toll-like receptor (TLR) 3, and blood groups have been directly or indirectly implicated in the susceptibility and pathogenesis of chikungunya.MethodsTo test the hypothesis that polymorphisms in genes coding for these molecules determine clinical outcomes of chikungunya infection, a retrospective case-control study was performed in León, Nicaragua. The study included 132 case patients and 132 controls, matched for age, sex and neighborhood. Case patients had clinical symptoms of chikungunya, which was diagnosed by means of polymerase chain reaction. Controls were individuals not reporting abrupt presentation of clinical chikungunya-like symptoms. Polymorphisms were identified by TaqMan single-nucleotide polymorphism genotyping assays.ResultsAfter adjustment for sociodemographic risk factors, chikungunya disease was associated with polymorphism in DC-SIGN and TLR3 genes (odds ratios, 5.2 and 3.3, respectively), and TNF-α with reduced persistent joint pain (0.24). Persistent joint pain was also associated with age, female sex and other comorbid conditions. Most interestingly, the Lewis-negative phenotype was strongly associated with both symptomatic chikungunya and immunoglobulin G seropositivity (odds ratios, 2.7, and 3.3, respectively).ConclusionThis study identified polymorphisms in DC-SIGN, TLR3, and TNF-α genes as well as Lewis-negative phenotype as risk factors for chikungunya infection and disease progression.
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| 21. |
- Bucardo, Filemon, et al.
(author)
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Asymptomatic Norovirus Infections in Nicaraguan Children and its Association With Viral Properties and Histo-blood Group Antigens
- 2010
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In: PEDIATRIC INFECTIOUS DISEASE JOURNAL. - : Williams and Wilkins. - 0891-3668 .- 1532-0987. ; 29:10, s. 934-939
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Journal article (peer-reviewed)abstract
- Background: It has been previously reported that histo-blood group antigens (HBGAs) and particularly secretor status provides protection against symptomatic norovirus infection, but it remains unclear to what extent this includes asymptomatic infections in children. Methods: To explore whether HBGAs or certain viral genotypes are associated with asymptomatic norovirus infections in a pediatric population in Nicaragua, we investigated 163 children andlt;= 5 years of age, without a recent history of diarrhea (andlt;= 10 days). Results: Asymptomatic norovirus infections were observed in 11.7% (19/163), with children andlt;= 6 months of age being most frequently infected (16%). Of the 19 norovirus-positive children, 4 (21%) and 10 (53%) were infected with genogroups GI and GII, respectively, and 4 children (21%) were infected with viruses of both genogroups. Most children had andgt;= 10(6) viral genomes per gram of feces. Nucleotide sequence analysis (15/19) revealed uncommon genotypes, such as, GII. 7 (n = 5) and GII. 2 (n = 3). An interesting observation was the low frequency of norovirus GII. 4 strains among the asymptomatic children. AB blood type, Lewis a (Lea(a+b-)) phenotype and nonsecretor genotype (se(428)se(428)) were not found among the asymptomatic children, but they occurred in population controls. Conclusions: Frequency of asymptomatic norovirus infections was similar to that observed in symptomatic children from Nicaragua. Norovirus GII. 2 and GII. 7 were frequently detected but the globally dominating GII. 4 was infrequent. Host genetic factors previously observed to be associated with protection against symptomatic norovirus infection were not found in this study.
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| 22. |
- Bucardo, Filemon, et al.
(author)
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Histo-blood group antigens and rotavirus vaccine shedding in Nicaraguan infants
- 2019
-
In: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 9
-
Journal article (peer-reviewed)abstract
- ABO, Lewis and secretor histo-blood group antigens (HBGA) are susceptibility factors for rotavirus in a P-genotype dependent manner and can influence IgA seroconversion rates following rotavirus vaccination. To investigate the association between HBGA phenotypes and rotavirus vaccine shedding fecal samples (n = 304) from a total of 141 infants vaccinated with Rotarix (n = 71) and RotaTeq (n = 70) were prospectively sampled in three time frames (= 3, 4-7 and = 8 days) after first vaccination dose. Rotavirus was detected with qPCR and genotypes determined by G/P multiplex PCR and/or sequencing. HBGAs were determined by hemagglutination and saliva based ELISA. Low shedding rates were observed, with slightly more children vaccinated with RotaTeq (19%) than Rotarix (11%) shedding rotavirus at = 4 days post vaccination (DPV). At = 4 DPV no infant of Lewis A (n = 6) or nonsecretor (n = 9) phenotype in the Rotarix cohort shed rotavirus; the same observation was made for Lewis A infants (n = 7) in the RotaTeq cohort. Putative in-vivo gene reassortment among RotaTeq strains occurred, yielding mainly G1P[8] strains. The bovine derived P[5] genotype included in RotaTeq was able to replicate and be shed at long time frames (amp;gt;13 DPV). The results of this study are consistent with that HBGA phenotype influences vaccine strain shedding as similarly observed for natural infections. Due to the low overall shedding rates observed, additional studies are however warranted.
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| 23. |
- Bucardo, Filemon, et al.
(author)
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Impact of vaccination on the molecular epidemiology and evolution of group A rotaviruses in Latin America and factors affecting vaccine efficacy
- 2015
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In: Infection, Genetics and Evolution. - : ELSEVIER SCIENCE BV. - 1567-1348 .- 1567-7257. ; 34, s. 106-113
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Research review (peer-reviewed)abstract
- Despite high rotavirus (RV) vaccine coverage (similar to 83%) and good effectiveness (similar to 77%) against RV-diarrhea hospitalization, RV is still contributing to the burden of diarrhea that persists in hospital settings in several Latin American countries, where RV vaccination is being implemented. Due to the extensive genomic and antigenic diversity, among co-circulating human RV, a major concern has been that the introduction of RV vaccination could exert selection pressure leading to higher prevalence of strains not included in the vaccines and/or emergence of new strains, thus, reducing the efficacy of vaccination. Here we review the molecular epidemiology of RV in Latin America and explore issues of RV evolution and selection in light of vaccination. We further explore etiologies behind the large burden of diarrhea remaining after vaccination in some countries and discuss plausible reasons for vaccine failures. (C) 2015 Elsevier B.V. All rights reserved.
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| 24. |
- Bucardo, F., et al.
(author)
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Large increase of rotavirus diarrhoea in the hospital setting associated with emergence of G12 genotype in a highly vaccinated population in Nicaragua.
- 2015
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In: Clinical Microbiology and Infection. - : Elsevier. - 1198-743X .- 1469-0691. ; 21:6, s. 603.e1-603.e7
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Journal article (peer-reviewed)abstract
- Rotaviruses (RVs) are a major cause of severe diarrhoea in young children. Nicaragua introduced routine immunization with the pentavalent RV vaccine (RV5) in 2006, which greatly reduced the incidence of diarrhoea. A remaining concern has been the possible emergence of new RV strains to which the vaccination has less effect. In this study, 837 children with diarrhoea in hospital settings were investigated for RV between May 2011 and July 2013. RVs were subsequently typed by multiplex PCR and/or sequencing. Fecal anti-RV IgA titres for a subset of RV-infected (n = 137) and noninfected children (n = 52) were determined with an in-house enzyme-linked immunosorbent assay. The RV detection rate was 8% in 2011, followed by a sharp increase to 29% in 2012 and 19% in 2013. This was associated with emergence and predominance of genotype G12 RV, from 0% in 2011 to 66% in 2012 and 82% in 2013, infecting children from 1 month to 10 years of age. Two sequenced G12 strains showed a Wa-like genome with genotype G12-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1, similar to the globally emerging G12 strains. Fecal anti-RV IgA analysis showed that most G12-infected and noninfected children had been in contact with either vaccine or wild RV strains, but such antibodies did not prevent symptomatic G12 infection. A marked increase of RV was evident in the hospital setting associated with a nationwide emergence and predominance of RV G12 genotype in a population with high RV5 vaccine coverage.
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| 25. |
- Bucardo, Filemon, et al.
(author)
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Low Prevalence of Rotavirus and High Prevalence of Norovirus in Hospital and Community Wastewater after Introduction of Rotavirus Vaccine in Nicaragua
- 2011
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In: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 6:10
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Journal article (peer-reviewed)abstract
- Rotavirus (RV) and norovirus (NoV) are major causes of pediatric diarrhea and are altogether associated with approximately 800,000 deaths in young children every year. In Nicaragua, national RV vaccination program using the pentavalent RV5 vaccine from Merck was implemented in October 2006. To determine whether RV vaccination decreased the overall number of RV infections, we investigated the occurrence of RV and NoV in wastewater in the city of Leon from July 2007 to July 2008 and compared these data with pre-vaccination data. The major finding was the low prevalence of RV compared to NoV in all sampling points (11% vs 44%, pandlt;0.05), and that RV concentration was lower as compared to NoV. RV was observed mainly during the rainy season (July-September), and the majority of all RV detected (6/9) belonged to subgroup (SG) I. The partial VP7-gene obtained from one RV positive sample was similar (99% nt identity) to a G6 VP7-gene of bovine origin and similar to the corresponding gene of the vaccine strain (98%). Furthermore RV G-types 2 and 4 were found in the incoming wastewater. NoV strains were detected throughout the year, of which a majority (20/21) were of genotype GII.4. We conclude that the introduction of RV vaccination reduced the transmission of RV in the community in Nicaragua. However, the burden of diarrhea in the country remains high, and the high prevalence of NoVs in hospital and municipal wastewater is noteworthy. This study highlights the need for further assessment of NoV following RV vaccine introduction.
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