1.Npac Is A Co-factor of Histone H3K36me3 and Regulates Transcriptional Elongation in Mouse Embryonic Stem Cells
Yu SUE ; Li JIA ; Ji GUANXU ; Ng Long ZHEN ; Siew JIAMIN ; Lo Ning WAN ; Ye YING ; Chew Yuan YUAN ; Long Chau YUN ; Zhang WENSHENG ; Guccione ERNESTO ; Loh Han YUIN ; Jiang ZHI-HONG ; Yang HENRY ; Wu QIANG
Genomics, Proteomics & Bioinformatics 2022;20(1):110-128
Chromatin modification contributes to pluripotency maintenance in embryonic stem cells(ESCs).However,the related mechanisms remain obscure.Here,we show that Npac,a"reader"of histone H3 lysine 36 trimethylation(H3K36me3),is required to maintain mouse ESC(mESC)pluripotency since knockdown of Npac causes mESC differentiation.Depletion of Npac in mouse embryonic fibroblasts(MEFs)inhibits reprogramming efficiency.Furthermore,our chromatin immunoprecipitation followed by sequencing(ChIP-seq)results of Npac reveal that Npac co-localizes with histone H3K36me3 in gene bodies of actively transcribed genes in mESCs.Interestingly,we find that Npac interacts with positive transcription elongation factor b(p-TEFb),Ser2-phosphorylated RNA Pol Ⅱ(RNA Pol Ⅱ Ser2P),and Ser5-phosphorylated RNA Pol Ⅱ(RNA Pol Ⅱ Ser5P).Furthermore,depletion of Npac disrupts transcriptional elongation of the pluripotency genes Nanog and Rifl.Taken together,we propose that Npac is essential for the transcriptional elongation of pluripotency genes by recruiting p-TEFb and interact-ing with RNA Pol Ⅱ Ser2P and Ser5P.
2.Encapsulation of Ginseng inside Poly(lactic-co-glycolic acid)/ Polyaniline Microcaspsules
Alex Zhen Kai Lo ; Siti Khadijah Lukman ; Syafiqah Saidin
Malaysian Journal of Medicine and Health Sciences 2020;16(Supp 8, Aug):1-5
Introduction: : Ginseng is a type of traditional medicine that has been used for thousand years to treat various diseases and has been proven effective in treating cardiovascular diseases. Incorporation of polyaniline (PANI) which is a type of conductive polymer together with ginseng into poly(lactic-co-glycolic acid) (PLGA) microcapsules is necessary for the treatment of cardiovascular diseases as the polymer will control drug release and the electroconductivity of PANI is beneficial on myocardium cells. Methods: Therefore, this project involved the encapsulation of ginseng inside PLGA/PANI microcapsules. The encapsulation of ginseng inside the microcapsules was verified through the identification of chemical composition of ginseng, PLGA and PANI using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). Results: The results of scanning electron microscope (SEM) showed the formation of microspheres where the microcapsule size was decreased from 3.14±1.87 μm to 1.98±1.30 μm as the concentration of PANI increased. The distribution of microcapsules size was more homogeneous in the high concentration of PANI as been determined through the histogram analysis. In addition, the fluorescence analysis demonstrated the efficiency of ginseng encapsulation inside PLGA/PANI microcapsules through the appearance of stained ginseng inside the microcapsules. Conclusion: As a conclusion, the ginseng was successfully encapsulated within PLGA/PANI microcapsules that will be beneficial in drug delivery application, specifically in the cardiovascular area.
3.Hyperkalemia measurement between Blood Gas Analyser and Main Laboratory Biochemistry Analyser
Mohd Helmie Ismail ; Kamarul Aryffin Baharuddin ; Mohd Azmi Suliman ; Mohd Faiz Mohd Shukri ; Siti Natrah Che Has ; Zhen Zhen Lo
The Medical Journal of Malaysia 2021;76(2):157-163
Introduction: Potassium level is measured for patients with
high risk of hyperkalemia in the emergency department (ED)
using both blood gas analyser (BGA) and biochemistry
analyser (BCA). The study was conducted to evaluate the
correlation and agreement of potassium measurement
between BGA and BCA.
Materials and Methods: This is a prospective cross-sectional
study on the data obtained from Hospital Universiti Sains
Malaysia (Hospital USM) from Jun 2018 until May 2019. Blood
samples were taken via a single prick from venous blood and
sent separately using 1ml heparinised syringe and were
analysed immediately in ED using BGA (Radiometer, ABL800
FLEX, Denmark) and another sample was sent to the central
laboratory of Hospital USM and analysed by BCA (Architect,
C8000, USA). Only patients who had potassium levels
≥5.0mmol/L on blood gas results were included. A total of 173
sample pairs were included. The correlation and agreement
were evaluated using Passing and Bablok regression, Linear
Regression and Bland-Altman test.
Result: Of the 173 sample pairs, the median of potassium
level based on BGA and BCA were 5.50mmol/L (IQR: 1.00)
and 5.90mmol/L (IQR: 0.95) respectively. There was
significant correlation between two measurements (p<0.001,
r: 0.36). The agreement between the two measurements
showed within acceptable mean difference which was 0.27
mmol/L with 95% limit of agreement were 1.21mmol/L to
1.73mmol/L.
Conclusion: The result of blood gas can be used as a guide
for initial treatment of hyperkalaemia in critical cases where
time is of the essence. However, BCA result is still the
definitive value.