3 research outputs found
Oxidative Stress Induces Transient OâGlcNAc Elevation and Tau Dephosphorylation in SHâSY5Y Cells
Oâlinked ÎČâNâacetlyglucosamine or OâGlcNAc modification is a dynamic postâtranslational modification occurring on the Ser/Thr residues of many intracellular proteins. The chronic imbalance between phosphorylation and OâGlcNAc on tau protein is considered as one of the main hallmarks of Alzheimer\u27s disease. In recent years, many studies also showed that OâGlcNAc levels can elevate upon acute stress and suggested that this might facilitate cell survival. However, many consider chronic stress, including oxidative damage as a major risk factor in the development of the disease. In this study, using the neuronal cell line SHâSY5Y we investigated the dynamic nature of OâGlcNAc after treatment with 0.5 mM H2O2 for 30 min. to induce oxidative stress. We found that overall OâGlcNAc quickly increased and reached peak level at around 2 hrs postâstress, then returned to baseline levels after about 24 hrs. Interestingly, we also found that tau protein phosphorylation at site S262 showed parallel, whereas at S199 and PHF1 sites showed inverse dynamic to OâGlycosylation. In conclusion, our results show that temporary elevation in OâGlcNAc modification after H2O2âinduced oxidative stress is detectable in cells of neuronal origin. Furthermore, oxidative stress changes the dynamic balance between OâGlcNAc and phosphorylation on tau proteins
Comparison of pediatric ventriculo-peritoneal shunt infections arising in antibiotic-impregnated and standard catheters: a multicenter observational study
Characteristics of children admitted to hospital with acute SARS-CoV-2 infection in Canada in 2020
Background: Risk factors for severe outcomes of SARS-CoV-2 infection are not
well established in children. We sought
to describe pediatric hospital admissions associated with SARS-CoV-2 infection in Canada and identify risk factors
for more severe disease.
Methods: We conducted a national prospective study using the infrastructure of
the Canadian Paediatric Surveillance
Program (CPSP). Cases involving children who were admitted to hospital with
microbiologically confirmed SARS-CoV-2
infection were reported from Apr. 8 to
Dec. 31 2020, through weekly online
questionnaires distributed to the CPSP
network of more than 2800 pediatricians. We categorized hospital admissions as related to COVID-19, incidental,
or for social or infection control reasons
and determined risk factors for disease
severity in hospital.
Results: Among 264 hospital admissions
involving children with SARS-CoV-2
infection during the 9-month study
period, 150 (56.8%) admissions were
related to COVID-19 and 100 (37.9%)
were incidental infections (admissions
for other reasons and found to be positive for SARS-CoV-2 on screening).
Infants (37.3%) and adolescents (29.6%)
represented most cases. Among hospital
admissions related to COVID-19, 52
(34.7%) had critical disease, 42 (28.0%)
of whom required any form of respiratory or hemodynamic support, and 59
(39.3%) had at least 1 underlying
comorbidity. Children with obesity,
chronic neurologic conditions or
chronic lung disease other than asthma
were more likely to have severe or critical COVID-19.
Interpretation: Among children who
were admitted to hospital with SARSCoV-2 infection in Canada during the
early COVID-19 pandemic period, incidental SARS-CoV-2 infection was common. In children admitted with acute
COVID-19, obesity and neurologic and
respiratory comorbidities were associated with more severe disease.Medicine, Faculty ofNon UBCPediatrics, Department ofReviewedFacultyResearche