Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
11 result(s) for "Tsui, Yvonne"
Sort by:
Methods for Photocrosslinking Alginate Hydrogel Scaffolds with High Cell Viability
Methods for seeding high-viability (>85%) three-dimensional (3D) alginate–chondrocyte hydrogel scaffolds are presented that employ photocrosslinking of methacrylate-modified alginate with the photoinitiator VA-086. Comparison with results from several other photoinitiators, including Irgacure 2959, highlights the role of solvent, ultraviolet exposure, and photoinitiator cytotoxicity on process viability of bovine chondrocytes in two-dimensional culture. The radicals generated from VA-086 photodissociation are shown to be noncytotoxic at w/v concentrations up to 1.5%, enabling photocrosslinking without significant cell death. The applicability of these photoinitiators for generating 3D tissue-engineered constructs is evaluated by measuring cell viability in 3D constructs with aggregate moduli in the 10–20 kPa range. Hydrogels with encapsulated bovine chondrocytes were constructed with >85% viability using VA-086. While the commonly used Irgacure 2959 is noncytotoxic in its native state and crosslinks the alginate at weight fractions much lower than VA-086, the cytotoxicity of IRG2959's photogenerated radical leads to viabilities below 70% in the conditions tested.
Systematic Selection of Reference Genes for the Normalization of Circulating RNA Transcripts in Pregnant Women Based on RNA-Seq Data
RNA transcripts circulating in peripheral blood represent an important source of non-invasive biomarkers. To accurately quantify the levels of circulating transcripts, one needs to normalize the data with internal control reference genes, which are detected at relatively constant levels across blood samples. A few reference gene candidates have to be selected from transcriptome data before the validation of their stable expression by reverse-transcription quantitative polymerase chain reaction. However, there is a lack of transcriptome, let alone whole-transcriptome, data from maternal blood. To overcome this shortfall, we performed RNA-sequencing on blood samples from women presenting with preterm labor. The coefficient of variation (CV) of expression levels was calculated. Of 11,215 exons detected in the maternal blood whole-transcriptome, a panel of 395 genes, including PPP1R15B, EXOC8, ACTB, and TPT1, were identified to comprise exons with considerably less variable expression level (CV, 7.75–17.7%) than any GAPDH exon (minimum CV, 27.3%). Upon validation, the selected genes from this panel remained more stably expressed than GAPDH in maternal blood. This panel is over-represented with genes involved with the actin cytoskeleton, macromolecular complex, and integrin signaling. This groundwork provides a starting point for systematically selecting reference gene candidates for normalizing the levels of circulating RNA transcripts in maternal blood.
Nascent Glial Precursors in Human Bone Marrow Allow Rapid Induction of Functional Oligodendrocyte Precursors for Therapy
Loss of myelinating oligodendrocytes and myelin impairs motor and cognitive functions. Transplantation of autologous oligodendrocyte precursors (OPCs) holds promise for treatment of such diseases, but a protocol to derive human OPCs from a safe, ethical and accessible cell source with the rapidity required to catch the therapeutic window remains to be found. Although we previously generated myelinating glia from rat bone marrow stromal cells (BMSCs), it remains unknown if clinically sourced human BMSCs (hBMSCs) share the same potential. Moreover, whether the multipotency of BMSCs results from diverse progenitors preexisting in the bone marrow or from a single multipotent progenitor population remains unaddressed. Single-cell RNA sequencing data revealed a CD90hiEGFR+PDGFRA+ pre-OPC-like subpopulation within hBMSCs. With a small-molecule-based (virus-free and supporting-cell-free) two-step induction protocol designed to expand this pre-OPC population, we generated functional OPCs with high purity in eight days. These derived OPCs showed phenotypic transcriptomes and immunoprofiles. They were also capable of myelinating naked axons when transplanted into myelin-deficient shiverer mice. Results highlight how targeted enrichment and maturation of specific progenitor subpopulations within hBMSCs allows rapid induction of desired cell types. These results place hBMSCs as a robust source of OPCs, unlocking the possibility for cell transplantation therapy for myelin deficiency in the central nervous system.
Iron Deficiency among School-Aged Adolescents in Hong Kong: Prevalence, Predictors, and Effects on Health-Related Quality of Life
Iron deficiency (ID) is a prevalent nutritional deficiency affecting children/adolescents worldwide. We reported (1) the prevalence of ID and ID with anemia (IDA) among Chinese school-aged adolescents, (2) clinical and dietary predictors of iron status, and (3) its impact on health-related qualities of life (HRQoL). This cross-sectional study recruited 183 boys and 340 girls (mean age = 17.55) from 16 schools in Hong Kong. ID is defined as serum ferritin <15 μg/L. The participants reported their dietary habits, menstrual patterns (girls), and HRQoL using structured questionnaires. The overall prevalence of ID was 11.1%. None of the boys had ID or IDA. Among girls, the rate of ID was 17.1% and IDA was 10.9%. One-third (36.3%) reported a regular habit of skipping ≥1 meal/day. Lower ferritin was found in adolescents who skipped meals (Est = −35.1, p = 0.017). Lower ferritin is correlated with poorer school functioning (Est = 0.81, p = 0.045) and fatigue (Est = 0.92, p = 0.016). Skipping meals is associated with poorer physical (p = 0.0017) and school functioning (p = 0.027). To conclude, 1 in 10 school-aged adolescents in Hong Kong are iron-deficient. The ID rate in girls (17.1%) is similar to that in other industrialized countries (5.2–16.6%). Future work should promote awareness on the potential health consequences of poor dietary habits on ID and the well-being of adolescents.
Molecular characteristics of Asian male BRCA-related cancers
PurposeGermline mutations of BRCA1 or BRCA2 predispose men to develop various cancers, including breast cancers and prostate cancers. Male breast cancer (MBC) is a rare disease while prostate cancer (PRC) is uncommon in young men at the age of less than 40. The prevalence of BRCA genes in Asian male patients has to be elevated.MethodsGermline mutations screening was performed in 98 high-risk Chinese MBC and PRC patients.ResultWe have identified 16 pathogenic BRCA2 mutation carriers, 12 were MBC patients, 2 were PRC patients and 2 were patients with both MBC and PRC. The mutation percentages were 18.8%, 6.7% and 50% for MBC, PRC and both MBC and PRC patients, respectively. BRCA2 gene mutations confer a significantly higher risk of breast/prostate cancers in men than those with BRCA1 mutations. BRCA mutated MBC patients had a younger age of diagnosis and strong family histories of breast cancers while BRCA mutated PRC patients had strong family histories of ovarian cancers.ConclusionMale BRCA carriers with breast cancers or prostate cancers showed distinct clinical and molecular characteristics, a male-specific genetic screening model would be useful to identify male cancer patients who have a high risk of BRCA mutation.
Training perinatal nurses in palliative communication by using scenario-based simulation: A quasi-experimental study
This study aimed to assess the impact of two educational modules on enhancing the communication confidence, competence and performance of perinatal nurses in the context of palliative care. Concerns have arisen regarding the preparedness of perinatal nurses in delivering palliative care, especially in terms of deficiencies in communication skills and negative attitudes toward making life-support decisions for parents facing neonates with terminal conditions. Bridging this gap necessitates improved perinatal palliative care education for healthcare providers. Research has shown that simulation-based teaching effectively enhances procedural competence, communication skills and confidence among healthcare professionals. However, comprehensive curricula focusing on perinatal palliative communication remain limited. This study used a quasi-experimental design employing a two-group repeated measure approach. It involved a purposive sample of 79 perinatal nurses from a hospital in northern Taiwan. A palliative communication course specifically designed for registered nurses in perinatal units was developed. Participants were allocated to either the experimental group (Scenario-Based Simulation, SBS) or the control group (traditional didactic lecture). Communication confidence and competence were assessed before and immediately after the course through structured questionnaires. Learning satisfaction was collected post-intervention and participants underwent performance evaluation by standardized parents one week later. A significant training gap in palliative care exists among nurses in OB/GYN wards, delivery rooms and neonatal critical care units, highlighting the need for continuing education. All 79 participants completed the training course. Following the intervention, nurses in the SBS group (n=39) exhibited significant improvements in self-reported confidence (p <0.05), competence (p <0.01) and performance (p <0.001) in neonatal palliative communication compared with the traditional didactic lecture group (n=40). The SBS group also received higher satisfaction ratings from nurse learners (p <0.001). The research findings support scenario-based simulation as a more effective educational approach compared with traditional didactic lectures for enhancing communication confidence and competence. These results were further reinforced by evaluation from standardized patients, highlighting the value of direct feedback in enhancing nurses' performance. Tailoring SBS designs to diverse nursing contexts and incorporating a flipped approach can further enrich the overall learning experience. Given its high effectiveness and positive reception, we recommend integrating this educational module into palliative care training programs for perinatal nurses.
Meta-analyses identify 13 loci associated with age at menopause and highlight DNA repair and immune pathways
Kathryn Lunetta and colleagues report a meta-analysis of 22 genome-wide association studies for age at menopause. They identify 13 loci newly associated with age at natural menopause, including several candidate genes with roles in DNA repair and immune function. To newly identify loci for age at natural menopause, we carried out a meta-analysis of 22 genome-wide association studies (GWAS) in 38,968 women of European descent, with replication in up to 14,435 women. In addition to four known loci, we identified 13 loci newly associated with age at natural menopause (at P < 5 × 10 −8 ). Candidate genes located at these newly associated loci include genes implicated in DNA repair ( EXO1 , HELQ , UIMC1 , FAM175A , FANCI , TLK1 , POLG and PRIM1 ) and immune function ( IL11 , NLRP11 and PRRC2A (also known as BAT2 )). Gene-set enrichment pathway analyses using the full GWAS data set identified exoDNase, NF-κB signaling and mitochondrial dysfunction as biological processes related to timing of menopause.
Dissection of Immune Gene Networks in Primary Melanoma Tumors Critical for Antitumor Surveillance of Patients with Stage II–III Resectable Disease
Patients with resected stage II–III cutaneous melanomas remain at high risk for metastasis and death. Biomarker development has been limited by the challenge of isolating high-quality RNA for transcriptome-wide profiling from formalin-fixed and paraffin-embedded (FFPE) primary tumor specimens. Using NanoString technology, RNA from 40 stage II–III FFPE primary melanomas was analyzed and a 53-immune-gene panel predictive of non-progression (area under the curve (AUC)=0.920) was defined. The signature predicted disease-specific survival (DSS P<0.001) and recurrence-free survival (RFS P<0.001). CD2, the most differentially expressed gene in the training set, also predicted non-progression (P<0.001). Using publicly available microarray data from 46 primary human melanomas (GSE15605), a coexpression module enriched for the 53-gene panel was then identified using unbiased methods. A Bayesian network of signaling pathways based on this data identified driver genes. Finally, the proposed 53-gene panel was confirmed in an independent test population of 48 patients (AUC=0.787). The gene signature was an independent predictor of non-progression (P<0.001), RFS (P<0.001), and DSS (P=0.024) in the test population. The identified driver genes are potential therapeutic targets, and the 53-gene panel should be tested for clinical application using a larger data set annotated on the basis of prospectively gathered data.
The effectiveness of low-dose desmopressin in improving hypothermia-induced impairment of primary haemostasis under influence of aspirin – a randomized controlled trial
Background Mild hypothermia (34–35 °C) increases perioperative blood loss. Our previous studies showed that desmopressin could have in vitro beneficial effects on hypothermia-induced primary haemostasis impairment. In this study, we investigate the in vitro effects of desmopressin on hypothermia-induced primary haemostasis impairment under the influence of aspirin in healthy volunteers. Methods Sixty healthy volunteers were randomly allocated to taking aspirin 100 mg or placebo for three days. On the sixth day blood samples were taken before and after the injection of desmopressin (1.5 microgram or 5 microgram) or normal saline subcutaneously. Measurements including Platelet Function Analyzer (PFA-100®) closure times, plasma von Willebrand Factor antigen, haemoglobin and platelet levels were made at 32 °C and 37 °C respectively. Results Collagen/epinephrine closure time (EPICT) was significantly prolonged by 21.13 % (95 %CI 2.34–39.74 %, p  = 0.021) in aspirin group at 37 °C. While hypothermia alone prolonged both collagen/adenosine diphosphate (ADPCT) and EPICT by 17.63 % (95 %CI 13.5–20.85 %, p  < 0.001) and 8.0 % (95 %CI 6.38–10.04 %, p  = 0.024) respectively, addition of aspirin only further prolonged EPICT by 19.9 % (95 %CI 3.32–36.49 %, p  = 0.013). In aspirin group, desmopressin 1.5 microgram and 5 microgram significantly reduced ADPCT to below baseline levels at 37 °C ( p  = 0.025 and <0.001 respectively), whereas reduction in EPICT was seen with desmopressin 5 microgram ( p =0.008). The effect was less pronounced at 32 °C, with a significant reduction in EPICT obtained with a dosage of 5 microgram only ( p  = 0.011). Conclusion It was shown that aspirin could further potentiate the hypothermia-induced closure time prolongations. Low dose desmopressin (1.5 microgram) reduced PFA-100® closure times towards baseline. A higher dosage (5 microgram) further reduced the closure times below baseline. Therefore low dose desmopressin (1.5 microgram) might have the potential to correct hypothermia-induced primary haemostasis impairment under the influence of aspirin during the perioperative period. Trial registration ClinicalTrials.gov: NCT01382134
Derivation of oligodendrocyte precursor cells from human bone marrow stromal cells and use for re-myelination in the congenitally dysmyelinated brain
Oligodendrocytes (OLs) are the only myelinating glia in the central nervous system (CNS). In congenital myelin disorders, OL dysfunction or death results in loss of myelin. This causes progressive and irreversible impairment to motor and cognitive functions, and is amongst the most disabling neurological disorder. Neonatal engraftment by glial progenitor cells (GPCs) allows the robust myelination of congenitally dysmyelinated brain, thereby preserving brain function and quality of life of patients. However, endogenous sources of glial progenitors are hard to obtain without causing secondary injury, while use of exogenous sources such as embryonic stem cells and induced-pluripotent stem cells face considerable ethical and safety issues. To circumvent such hurdles, we asked whether NG2+ cells in the bone marrow could be a potential cell source for GPCs. We successfully generated glial progenitor cells (GPCs) from human bone marrow stromal cells (hBMSCs) from 3 donors using a 14-day induction protocol. The generated hBMSC-GPCs were highly enriched in OPC marker expression, including OLIG2, PDGFRα, NG2, SOX10 and O4, and showed efficient differentiation into myelinogenic oligodendrocytes when transplanted into postnatal day 7 (P7) myelin-deficient shiverer mice. Remyelination of the shiverer mouse brain significantly extended lifespan and improved motor function. The novel induction protocol described here provides a method for fast, simple and effective glial therapy for myelin disorders, overcoming existent hurdles of cell source restriction and time frame requirement.