1.Diffusion-weighted magnetic resonance imaging in a case of osmotic demyelination syndrome with fatal outcome
Shen-Yang Lim ; ,Ismaliza Ismail ; Sharon Mei-Ling Tai ; Khairul Azmi Abdul Kadir ; Li-Ping Tan ; Yip-Boon Chong ; Nortina Shahrizaila
Neurology Asia 2011;16(1):89-92
Hyponatraemia with rapid correction of serum sodium may cause an osmotic demyelination syndrome
(ODS) with damage to pontine and/or extrapontine areas of the brain. The prognosis of ODS can range
from complete recovery to death; at present, our ability to predict clinical outcome is very limited. We
describe here a patient with ODS and increased signal intensity in the striatum on diffusion-weighted
MRI, with corresponding low apparent diffusion coeffi cient values (indicating restricted water diffusion).
This case provides a further example of the typical MRI appearance of extrapontine ODS and suggests
the potential value of diffusion-weighted MRI in predicting prognosis in ODS.
2.Purification and identification of novel cytotoxic oligopeptides from soft coral Sarcophyton glaucum.
Yixian QUAH ; Nor Ismaliza MOHD ISMAIL ; Jillian Lean Sim OOI ; Yang Amri AFFENDI ; Fazilah ABD MANAN ; Lai-Kuan TEH ; Fai-Chu WONG ; Tsun-Thai CHAI
Journal of Zhejiang University. Science. B 2019;20(1):59-70
Globally, peptide-based anticancer therapies have drawn much attention. Marine organisms are a reservoir of anticancer peptides that await discovery. In this study, we aimed to identify cytotoxic oligopeptides from Sarcophyton glaucum. Peptides were purified from among the S. glaucum hydrolysates produced by alcalase, chymotrypsin, papain, and trypsin, guided by a methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay on the human cervical cancer (HeLa) cell line for cytotoxicity evaluation. Purification techniques adopted were membrane ultrafiltration, gel filtration chromatography, solid phase extraction (SPE), and reversed-phase high-performance liquid chromatography (RP-HPLC). Purified peptides were identified by de novo peptide sequencing. From papain hydrolysate, three peptide sequences were identified: AGAPGG, AERQ, and RDTQ (428.45, 502.53, and 518.53 Da, respectively). Peptides synthesized from these sequences exhibited cytotoxicity on HeLa cells with median effect concentration (EC50) values of 8.6, 4.9, and 5.6 mmol/L, respectively, up to 5.8-fold stronger than the anticancer drug 5-fluorouracil. When tested at their respective EC50, AGAPGG, AERQ, and RDTQ showed only 16%, 25%, and 11% cytotoxicity to non-cancerous Hek293 cells, respectively. In conclusion, AERQ, AGAPGG, and RDTQ are promising candidates for future development as peptide-based anticancer drugs.
Amino Acid Sequence
;
Animals
;
Anthozoa/chemistry*
;
Antineoplastic Agents/pharmacology*
;
Chromatography, Gel
;
Chromatography, High Pressure Liquid
;
Chromatography, Reverse-Phase
;
Cytotoxins/pharmacology*
;
Drug Discovery
;
HEK293 Cells
;
HeLa Cells
;
Humans
;
Hydrolysis
;
Marine Toxins/pharmacology*
;
Oligopeptides/pharmacology*
;
Solid Phase Extraction
;
Tandem Mass Spectrometry