799 research outputs found
Survival and Growth of Adult Human Oligodendrocytes in Culture: Scanning Electron Microscopy
The oligodendrocytes in culture serve as an important model for the study of demyelination diseases. We have previously originated a method of isolating human oligodendrocytes. In order to establish their three dimensional morphology, scanning electron microscopy of the cultured oligodendrocytes was performed.
The oligodendrocytes bulk isolated from adult human brain were maintained in culture for more than 2 months. At the various periods in culture, the cells were studied by scanning electron microscopy and immunofluorescence staining using marker antibodies for the identification of oligodendrocytes. The three dimensional organization and the surface morphology of the cultured oligodendrocytes were investigated. They displayed an extensive network of the cell processes and characteristic surface morphology
Dissolution of Spinel Oxides and Capacity Losses in 4 V Li/LixMn2O4 Cells
Dissolution of spinel manganese oxides and the concomitant cathodic capacity losses were examined in 4 V Li/PC +
DME + LiClO4/LiMn2O4 cells where PC is propylene carbonate and DME is dimethoxyethane. Dissolved Mn2 contents
in the electrolytes were analyzed as a function of cathode potential and carbon contents in the composite cathodes.
Characteristically, manganese dissolution was notably high at the charged state (at >4.1 V vs. Li/Lit), in which potential
range an electrochemical oxidation of the solvent molecules was also prominent. From this and another observation
whereby the Mn dissolution increased with increasing carbon content in the composite cathodes, it was proposed that, at
the charged state of the cathode the solvent molecules are electrochemically oxidized on carbon surfaces and an as-generated
species promotes the manganese dissolution. Results of an ac impedance study revealed that Mn dissolution brings
about an increase in contact resistances at the Mn-depleted spinel/carbon interface, and also in the electrode reaction
resistances for Li intercalation/deintercalation. Thus, the Mn dissolution causes capacity losses in two different pathways;
material loss of the loaded spinel and polarization loss due to a cell resistance increment. The former prevailed
when cathodes contained excess amounts of carbon, while the latter became more of a problem as the carbon contents
decreased
Transdifferentiation-inducing HCCR-1 oncogene
<p>Abstract</p> <p>Background</p> <p>Cell transdifferentiation is characterized by loss of some phenotypes along with acquisition of new phenotypes in differentiated cells. The differentiated state of a given cell is not irreversible. It depends on the up- and downregulation exerted by specific molecules.</p> <p>Results</p> <p>We report here that <it>HCCR-1</it>, previously shown to play an oncogenic role in human cancers, induces epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET) in human and mouse, respectively. The stem cell factor receptor CD117/c-Kit was induced in this transdifferentiated (EMT) sarcoma tissues. This MET occurring in <it>HCCR-1 </it>transfected cells is reminiscent of the transdifferentiation process during nephrogenesis. Indeed, expression of <it>HCCR-1 </it>was observed during the embryonic development of the kidney. This suggests that <it>HCCR-1 </it>might be involved in the transdifferentiation process of cancer stem cell.</p> <p>Conclusions</p> <p>Therefore, we propose that <it>HCCR-1 </it>may be a regulatory factor that stimulates morphogenesis of epithelia or mesenchyme during neoplastic transformation.</p
Plant species of Sub-Family Valerianaceae—A review on its effect on the Central Nervous System
Valerianaceae, the sub-family of Caprifoliaceae, contains more than 300 species of annual and perennial herbs, worldwide distributed. Several species are used for their biological properties while some are used as food. Species from the genus Valeriana have been used for their antispasmodic, relaxing, and sedative properties, which have been mainly attributed to the presence of valepotriates, borneol derivatives, and isovalerenic acid. Among this genus, the most common and employed species is Valerianaofficinalis. Although valerian has been traditionally used as a mild sedative, research results are still controversial regarding the role of the different active compounds, the herbal preparations, and the dosage used. The present review is designed to summarize and critically describe the current knowledge on the different plant species belonging to Valerianaceae, their phytochemicals, their uses in the treatment of different diseases with particular emphasis on the effects on the central nervous system. The available information on this sub-family was collected from scientific databases up until year 2020. The following electronic databases were used: PubMed, Scopus, Sci Finder, Web of Science, Science Direct, NCBI, and Google Scholar. The search terms used for this review included Valerianaceae, Valeriana, Centranthus, Fedia, Patrinia, Nardostachys, Plectritis, and Valerianella, phytochemical composition, in vivo studies, Central Nervous System, neuroprotective, antidepressant, antinociceptive, anxiolytic, anxiety, preclinical and clinical studies.UIDB/05183/2020, DL 57/2016/CP1361/CT0022, UIDB/00313/2020info:eu-repo/semantics/publishedVersio
Effect of renal Doppler ultrasound on the detection of nutcracker syndrome in children with hematuria
To assess the detection rate of nutcracker syndrome in children with isolated hematuria, renal Doppler ultrasound examinations were routinely performed on 216 consecutive children (176 microscopic hematuria and 40 gross hematuria). Renal Doppler ultrasound was also performed on 32 healthy normal children. The peak velocity (PV) was measured at the hilar portion of the left renal vein (LRV) and at the LRV between the aorta and the superior mesenteric artery. The PV at the aortomesenteric portion (P=0.003) and the PV ratios of the LRV (P=0.003) were significantly higher in children with hematuria than in normal children, while the PV at the hilar portion was not different. If a PV ratio of the LRV of at least 4.1 (the cut-off level set at the mean ±2 SD of the value for the normal children) was defined as abnormal, 72 cases (33.3%) in children with hematuria and no cases in normal children were diagnosed as having nutcracker syndrome. The prevalence of nutcracker syndrome is relatively high in children with isolated hematuria, and the inclusion of renal Doppler ultrasound as a screening examination has a substantial effect on the detection of nutcracker syndrome
Gravitational-wave Electromagnetic Counterpart Korean Observatory (GECKO): GECKO Follow-up Observation of GW190425
One of the keys to the success of multimessenger astronomy is the rapid
identification of the electromagnetic wave counterpart, kilonova (KN), of the
gravitational-wave (GW) event. Despite its importance, it is hard to find a KN
associated with a GW event, due to a poorly constrained GW localization map and
numerous signals that could be confused as a KN. Here, we present the
Gravitational-wave Electromagnetic wave Counterpart Korean Observatory (GECKO)
project, the GECKO observation of GW190425, and prospects of GECKO in the
fourth observing run (O4) of the GW detectors. We outline our follow-up
observation strategies during O3. In particular, we describe our
galaxy-targeted observation criteria that prioritize based on galaxy
properties. Armed with this strategy, we performed an optical and/or
near-infrared follow-up observation of GW190425, the first binary neutron star
merger event during the O3 run. Despite a vast localization area of 7460 deg^2,
we observed 621 host galaxy candidates, corresponding to 29.5% of the scores we
assigned, with most of them observed within the first 3 days of the GW event.
Ten transients were discovered during this search, including a new transient
with a host galaxy. No plausible KN was found, but we were still able to
constrain the properties of potential KNe using upper limits. The GECKO
observation demonstrates that GECKO can possibly uncover a GW170817-like KN at
a distance less than 200 Mpc if the localization area is of the order of
hundreds of square degrees, providing a bright prospect for the identification
of GW electromagnetic wave counterparts during the O4 run.Comment: 35 pages, 19 figures Accepted for publication in Ap
Multidrug resistant pulmonary tuberculosis treatment regimens and patient outcomes: an individual patient data meta-analysis of 9,153 patients.
Treatment of multidrug resistant tuberculosis (MDR-TB) is lengthy, toxic, expensive, and has generally poor outcomes. We undertook an individual patient data meta-analysis to assess the impact on outcomes of the type, number, and duration of drugs used to treat MDR-TB
Sex differences in body composition affect total airway resistance during puberty
Abstract
Background
During puberty, changes in body composition due to sex hormones are associated with lung mechanics. However, little is known about the mediation effect of sex differences in body composition during puberty with total airway resistance.
Methods
We prospectively recruited 620 children (10–12years old) from the general population and conducted a cross-sectional study. This study assessed pubertal status according to the five Tanner stages using a questionnaire, line drawings, and each subjects blood sex hormone profile. Both the impulse oscillation system for total lung mechanics and multifrequency bioelectrical impedance for body composition analyses were conducted. The effects of puberty on body composition and subsequent total lung resistance were evaluated using mediation analysis.
Results
Among the 503 children enrolled, there were 261 males (51.9%) and 242 females (48.1%). In males, higher testosterone levels corresponded with reduced total lung resistance (β = –0.13, 95% CI = –0.21 to –0.05, p < 0.001), and the proportion of the mediating effect through the muscle-fat ratio was 19% (95% CI = 4 to 59, p = 0.02). In contrast, in females, pubertal status reduced total lung resistance (β = –0.27, 95% CI = –0.58 to –0.05, p = 0.04), however, the proportion of the mediating effect through the body mass index was –51% (95% CI = –244 to –4%, p = 0.04).
Conclusion
The muscle-fat ratio in adolescent males had a synergistic effect with testosterone on improving total airway resistance, whereas improvements in lung resistance by pubertal status were partially masked by body mass index in adolescent females. In conclusion, body composition changes during puberty between males and females have differing effects on total airway resistance
Comparative safety of mRNA COVID-19 vaccines to influenza vaccines: A pharmacovigilance analysis using WHO international database.
Funder: New faculty research seed money grant of Yonsei University College of Medicine for 2021 (2021-32-0049).Two messenger RNA (mRNA) vaccines developed by Pfizer-BioNTech and Moderna are being rolled out. Despite the high volume of emerging evidence regarding adverse events (AEs) associated with the COVID-19 mRNA vaccines, previous studies have thus far been largely based on the comparison between vaccinated and unvaccinated control, possibly highlighting the AE risks with COVID-19 mRNA vaccination. Comparing the safety profile of mRNA vaccinated individuals with otherwise vaccinated individuals would enable a more relevant assessment for the safety of mRNA vaccination. We designed a comparative safety study between 18 755 and 27 895 individuals who reported to VigiBase for adverse events following immunization (AEFI) with mRNA COVID-19 and influenza vaccines, respectively, from January 1, 2020, to January 17, 2021. We employed disproportionality analysis to rapidly detect relevant safety signals and compared comparative risks of a diverse span of AEFIs for the vaccines. The safety profile of novel mRNA vaccines was divergent from that of influenza vaccines. The overall pattern suggested that systematic reactions like chill, myalgia, fatigue were more noticeable with the mRNA COVID-19 vaccine, while injection site reactogenicity events were more prevalent with the influenza vaccine. Compared to the influenza vaccine, mRNA COVID-19 vaccines demonstrated a significantly higher risk for a few manageable cardiovascular complications, such as hypertensive crisis (adjusted reporting odds ratio [ROR], 12.72; 95% confidence interval [CI], 2.47-65.54), and supraventricular tachycardia (adjusted ROR, 7.94; 95% CI, 2.62-24.00), but lower risk of neurological complications such as syncope, neuralgia, loss of consciousness, Guillain-Barre syndrome, gait disturbance, visual impairment, and dyskinesia. This study has not identified significant safety concerns regarding mRNA vaccination in real-world settings. The overall safety profile patterned a lower risk of serious AEFI following mRNA vaccines compared to influenza vaccines
Association of adverse respiratory events with sodium-glucose cotransporter 2 inhibitors versus dipeptidyl peptidase 4 inhibitors among patients with type 2 diabetes in South Korea:a nationwide cohort study
BACKGROUND: Impaired respiratory function remains underrecognized in patients with type 2 diabetes (T2D), despite common pulmonary impairment. Meanwhile, there is little data available on the respiratory effects of sodium glucose cotransporter 2 inhibitors (SGLT2i). Hence, we examined the association between SGLT2i use and the risk of adverse respiratory events in a real-world setting. METHODS: We conducted a population-based, nationwide cohort study using an active-comparator new-user design and nationwide claims data of South Korea from January 2015 to December 2020. Among individuals aged 18 years or older, propensity score matching was done to match each new user of SGLT2is with dipeptidyl peptidase 4 inhibitors (DPP4is), with patients followed up according to an as-treated definition. The primary outcome was respiratory events, a composite endpoint of acute pulmonary edema, acute respiratory distress syndrome (ARDS), pneumonia, and respiratory failure. Secondary outcomes were the individual components of the primary outcome and in-hospital death. Cox models were used to estimate hazard ratios (HRs) and 95% CIs. RESULTS: Of 205,534 patient pairs in the propensity score matched cohort, the mean age of the entire cohort was 53.8 years and 59% were men, with a median follow-up of 0.66 years; all baseline covariates achieved balance between the two groups. Incidence rates for overall respiratory events were 4.54 and 7.54 per 1000 person-years among SGLT2i and DPP4i users, respectively, corresponding to a rate difference of 3 less events per 1000 person-years (95% CI - 3.44 to - 2.55). HRs (95% CIs) were 0.60 (0.55 to 0.64) for the composite respiratory endpoint, 0.35 (0.23 to 0.55) for acute pulmonary edema, 0.44 (0.18 to 1.05) for ARDS, 0.61 (0.56 to 0.66) for pneumonia, 0.49 (0.31 to 0.76) for respiratory failure, and 0.46 (0.41 to 0.51) for in-hospital death. Similar trends were found across individual SGLT2is, subgroup analyses of age, sex, history of comorbidities, and a range of sensitivity analyses. CONCLUSIONS: These findings suggest a lower risk of adverse respiratory events associated with patients with T2D initiating SGLT2is versus DPP4is. This real-world evidence helps inform patients, clinicians, and guideline writers regarding the respiratory effects of SGLT2i in routine practice
- …