20 research outputs found

    Exogenous lipoid pneumonia associated with oil pulling: Report of two cases

    Get PDF
    Two ladies with history of carcinoma of tongue presenting with un-resolving pneumonia were ultimately diagnosed to have lipoid pneumonia, and both were subsequently found to be associated with the practice of oil pulling which is a popular complementary therapy. Apart from cessation of oil pulling, they were treated with repeated therapeutic lobar broncho-alveolar lavage. despite the potential benefits of oil pulling on oral health, people especially those at risk of aspiration, should be properly informed of this potential risk when considering this form of complementary therapy

    <i>De novo</i> phosphatidylcholine synthesis is required for autophagosome membrane formation and maintenance during autophagy.

    Get PDF
    Macroautophagy/autophagy can enable cancer cells to withstand cellular stress and maintain bioenergetic homeostasis by sequestering cellular components into newly formed double-membrane vesicles destined for lysosomal degradation, potentially affecting the efficacy of anti-cancer treatments. Using 13C-labeled choline and 13C-magnetic resonance spectroscopy and western blotting, we show increased de novo choline phospholipid (ChoPL) production and activation of PCYT1A (phosphate cytidylyltransferase 1, choline, alpha), the rate-limiting enzyme of phosphatidylcholine (PtdCho) synthesis, during autophagy. We also discovered that the loss of PCYT1A activity results in compromised autophagosome formation and maintenance in autophagic cells. Direct tracing of ChoPLs with fluorescence and immunogold labeling imaging revealed the incorporation of newly synthesized ChoPLs into autophagosomal membranes, endoplasmic reticulum (ER) and mitochondria during anticancer drug-induced autophagy. Significant increase in the colocalization of fluorescence signals from the newly synthesized ChoPLs and mCherry-MAP1LC3/LC3 (microtubule-associated protein 1 light chain 3) was also found on autophagosomes accumulating in cells treated with autophagy-modulating compounds. Interestingly, cells undergoing active autophagy had an altered ChoPL profile, with longer and more unsaturated fatty acid/alcohol chains detected. Our data suggest that de novo synthesis may be required to increase autophagosomal ChoPL content and alter its composition, together with replacing phospholipids consumed from other organelles during autophagosome formation and turnover. This addiction to de novo ChoPL synthesis and the critical role of PCYT1A may lead to development of agents targeting autophagy-induced drug resistance. In addition, fluorescence imaging of choline phospholipids could provide a useful way to visualize autophagosomes in cells and tissues.Abbreviations AKT: AKT serine/threonine kinase; BAX: BCL2 associated X, apoptosis regulator; BECN1: beclin 1; ChoPL: choline phospholipid; CHKA: choline kinase alpha; CHPT1: choline phosphotransferase 1; CTCF: corrected total cell fluorescence; CTP: cytidine-5'-triphosphate; DCA: dichloroacetate; DMEM: dulbeccos modified Eagles medium; DMSO: dimethyl sulfoxide; EDTA: ethylenediaminetetraacetic acid; ER: endoplasmic reticulum; GDPD5: glycerophosphodiester phosphodiesterase domain containing 5; GFP: green fluorescent protein; GPC: glycerophosphorylcholine; HBSS: hanks balances salt solution; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; LPCAT1: lysophosphatidylcholine acyltransferase 1; LysoPtdCho: lysophosphatidylcholine; MRS: magnetic resonance spectroscopy; MTORC1: mechanistic target of rapamycin kinase complex 1; PCho: phosphocholine; PCYT: choline phosphate cytidylyltransferase; PLA2: phospholipase A2; PLB: phospholipase B; PLC: phospholipase C; PLD: phospholipase D; PCYT1A: phosphate cytidylyltransferase 1, choline, alpha; PI3K: phosphoinositide-3-kinase; pMAFs: pancreatic mouse adult fibroblasts; PNPLA6: patatin like phospholipase domain containing 6; Pro-Cho: propargylcholine; Pro-ChoPLs: propargylcholine phospholipids; PtdCho: phosphatidylcholine; PtdEth: phosphatidylethanolamine; PtdIns3P: phosphatidylinositol-3-phosphate; RPS6: ribosomal protein S6; SCD: stearoyl-CoA desaturase; SEM: standard error of the mean; SM: sphingomyelin; SMPD1/SMase: sphingomyelin phosphodiesterase 1, acid lysosomal; SGMS: sphingomyelin synthase; WT: wild-type

    Optimization of indoor air temperature set-point for centralized air-conditioned spaces in subtropical climates

    No full text
    2009-2010 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptRGCOthersRGC: Research Grants Council of the HKSAR, China (B-Q11W)Others: The Hong Kong Polytechnic University (Project A/C code: G-YX1Y)Publishe

    Air quality influence on chronic obstructive pulmonary disease (COPD) patients' quality of life

    No full text
    2010-2011 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptOthers[a0680-n20/912] The Hong Kong Polytechnic University (No. GYF21)Publishe

    Processing of speech in Chinese students with different reading abilities – an FMRI study

    No full text
    While imaging studies with English-speaking children showed that reading achievement of children is associated with their brain profiles during speech perception tasks, little is known about the neurocognitive processing of normal\ud Chinese students with different reading proficiencies: To study the neurocognitive processing on Chinese and the input of reading level on the process, seventeen six year old students with Chinese as their first language were recruited for the research study. These students were further assessed by a reading test to distinguish their Chinese reading ability. Those scored 2/3 deviation\ud below the cultural mean score were classified as low-proficiency readers. Those scored between 2/3 below or above the mean score were classified as intermediate-proficiency readers. Those scored 2/3 standard deviation above the mean score were regarded as high-proficiency readers. During the experiment, 12 pairs of Chinese syllables evenly distributed in three stimuli blocks were presented to the students acoustically and they had to judge whether each pair of syllables was the same in rhyme\ud or not. Throughout the whole process the students' brain activation profiles were assessed by FMRl examination using the BOW (blood oxygen level dependent) contrast method in a 1. 5 T MRI system. Result analysis was focussed on the possible neurocognitive discrepancies between students of varying reading proficiency on phonological sensitivity
    corecore