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Sung HK, Tang J, Jahng JWS, Song E, Chan YK, Lone AH, Peterson J, Abdul‐Sater A, Sweeney G. Ischemia-induced cardiac dysfunction is exacerbated in adiponectin-knockout mice due to impaired autophagy flux. Clin Transl Sci 2024; 17:e13758. [PMID: 38515365 PMCID: PMC10958170 DOI: 10.1111/cts.13758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 01/23/2024] [Accepted: 02/14/2024] [Indexed: 03/23/2024] Open
Abstract
Strategies to enhance autophagy flux have been suggested to improve outcomes in cardiac ischemic models. We explored the role of adiponectin in mediating cardiac autophagy under ischemic conditions induced by permanent coronary artery ligation. We studied the molecular mechanisms underlying adiponectin's cardio-protective effects in adiponectin knockout (Ad-KO) compared with wild-type (WT) mice subjected to ischemia by coronary artery ligation and H9c2 cardiomyocyte cell line exposed to hypoxia. Systemic infusion of a cathepsin-B activatable near-infrared probe as a biomarker for autophagy and detection via noninvasive three-dimensional fluorescence molecular tomography combined with computerized tomography to quantitate temporal changes, indicated increased activity in the myocardium of WT mice after myocardial infarction which was attenuated in Ad-KO. Seven days of ischemia increased myocardial adiponectin accumulation and elevated ULK1/AMPK phosphorylation and autophagy assessed by Western blotting for LC3 and p62, an outcome not observed in Ad-KO mice. Cell death, assessed by TUNEL analysis and the ratio of Bcl-2:Bax, plus cardiac dysfunction, measured using echocardiography with strain analysis, were exacerbated in Ad-KO mice. Using cellular models, we observed that adiponectin stimulated autophagy flux in isolated primary adult cardiomyocytes and increased basal and hypoxia-induced autophagy in H9c2 cells. Real-time temporal analysis of caspase-3/7 activation and caspase-3 Western blot indicated that adiponectin suppressed activation by hypoxia. Hypoxia-induced mitochondrial reactive oxygen species production and cell death were also attenuated by adiponectin. Importantly, the ability of adiponectin to reduce caspase-3/7 activation and cell death was not observed in autophagy-deficient cells generated by CRISPR-mediated deletion of Atg7. Collectively, our data indicate that adiponectin acts in an autophagy-dependent manner to attenuate cardiomyocyte caspase-3/7 activation and cell death in response to hypoxia in vitro and ischemia in mice.
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Fedoruk KA, Chan YK, Williams CE. Scholarship in anesthesiology: the role of critical appraisal, literature review, quality improvement, journal club, and presentation skills. Int J Obstet Anesth 2023; 54:103639. [PMID: 36841065 DOI: 10.1016/j.ijoa.2023.103639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 12/27/2022] [Accepted: 01/29/2023] [Indexed: 02/05/2023]
Abstract
If asked to describe the term "anesthesiologist scholar", one may receive a variety of definitions depending on the individual's area of practice, location in the world, and the generation in which they trained. In this article, we review the roles of five core elements that make an anesthesiologist a "scholar": skills in critical appraisal, literature review, quality improvement, journal club participation, and presentation delivery. Although this list of scholarly components is not comprehensive, review of each element's role in the everyday practice and training of physicians will offer insight into their evolution and may offer a glimpse into the future of anesthesiologist scholars. Overall, through the dissemination, recognition, and support of scholarship through these practices, we will continue to achieve meaningful outcomes for our patients and promote a culture of collaboration worldwide. We should ensure that these topic areas become a bedrock of medical education globally, and we must foster opportunities for those who have already completed training to develop and master these skills as a part of their clinical and academic practice.
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Chan YK, Novalo Goto ES, Fachini Jardim Criado R, Criado PR. Allergic contact dermatitis by ophthalmological medications in Brazil: experience of a dermatology department. Eur Ann Allergy Clin Immunol 2021; 53:280-283. [PMID: 33728833 DOI: 10.23822/eurannaci.1764-1489.190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Summary Topical treatments in ophthalmologic therapy are significant for the development of allergic contact dermatitis (ACD) in the periorbital region. Preservatives, antibiotics, glucocorticoids, and beta-blocker eye drops are defined as drugs with the highest sensitizing potential. The unavailability of patch test batteries containing substances of ophthalmological use makes it difficult for this diagnosis. In the present report, we describe six patients who developed ACD induced by different agents presenting in eye drops, confirmed with the cutaneous patch tests. The ACD diagnosis due to ophthalmic medications can be challenging, since many different agents can cause it, and the sensitivity of these cutaneous tests is low. Thus, early diagnosis is essential to avoid the complications of ACD on the skin and ocular disorders related to chronic periorbital eczema.
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Abulizi N, Quin C, Brown K, Chan YK, Gill SK, Gibson DL. Gut Mucosal Proteins and Bacteriome Are Shaped by the Saturation Index of Dietary Lipids. Nutrients 2019; 11:nu11020418. [PMID: 30781503 PMCID: PMC6412740 DOI: 10.3390/nu11020418] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 02/01/2019] [Accepted: 02/13/2019] [Indexed: 02/07/2023] Open
Abstract
The dynamics of the tripartite relationship between the host, gut bacteria and diet in the gut is relatively unknown. An imbalance between harmful and protective gut bacteria, termed dysbiosis, has been linked to many diseases and has most often been attributed to high-fat dietary intake. However, we recently clarified that the type of fat, not calories, were important in the development of murine colitis. To further understand the host-microbe dynamic in response to dietary lipids, we fed mice isocaloric high-fat diets containing either milk fat, corn oil or olive oil and performed 16S rRNA gene sequencing of the colon microbiome and mass spectrometry-based relative quantification of the colonic metaproteome. The corn oil diet, rich in omega-6 polyunsaturated fatty acids, increased the potential for pathobiont survival and invasion in an inflamed, oxidized and damaged gut while saturated fatty acids promoted compensatory inflammatory responses involved in tissue healing. We conclude that various lipids uniquely alter the host-microbe interaction in the gut. While high-fat consumption has a distinct impact on the gut microbiota, the type of fatty acids alters the relative microbial abundances and predicted functions. These results support that the type of fat are key to understanding the biological effects of high-fat diets on gut health.
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Goh PK, Chiu CL, Wang CY, Chan YK, Loo PL. Randomized Double-blind Comparison of Ketamine-Propofol, Fentanyl-Propofol and Propofol-Saline on Haemodynamics and Laryngeal Mask Airway Insertion Conditions. Anaesth Intensive Care 2019; 33:223-8. [PMID: 15960405 DOI: 10.1177/0310057x0503300211] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The aim of this prospective, double-blind, randomized, placebo-controlled clinical trial was to investigate whether the administration of ketamine before induction with propofol improves its associated haemodynamic profile and laryngeal mask airway (LMA) insertion conditions. Ninety adult patients were randomly allocated to receive either ketamine 0.5 mg.kg-1 (n=30), fentanyl 1 μg.kg-1 (n=30) or normal saline (n=30), before induction of anaesthesia with propofol 2.5 mg.kg-1. Insertion of the LMA was performed 60s after injection of propofol. Arterial blood pressure and heart rate were measured before induction (baseline), immediately after induction, immediately before LMA insertion, immediately after LMA insertion and every minute for three minutes after LMA insertion. Following LMA insertion, the following six subjective endpoints were graded by a blinded anaesthestist using ordinal scales graded 1 to 3: mouth opening, gagging, swallowing, movement, laryngospasm and ease of insertion. Systolic blood pressure was significantly higher following ketamine than either fentanyl (P=0.010) or saline (P=0.0001). The median (interquartile range) summed score describing the overall insertion conditions were similar in the ketamine [median 7.0, interquartile range (6.0–8.0)] and fentanyl groups [median 7.0, interquartile range (6.0–8.0)]. Both appeared significantly better than the saline group [median 8.0, interquartile range (6.75–9.25); P=0.024]. The incidence of prolonged apnoea (>120s) was higher in the fentanyl group [23.1% (7/30)] compared with the ketamine [6.3% (2/30)] and saline groups [3.3% (1/30)]. We conclude that the addition of ketamine 0.5 mg.kg–1 improves haemo-dynamics when compared to fentanyl 1 μg.kg–1, with less prolonged apnoea, and is associated with better LMA insertion conditions than placebo (saline).
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Ortolani O, Conti A, Chan YK, Sie MY, Ong GSY. Comparison of Propofol Consumption and Recovery Time in Caucasians from Italy, with Chinese, Malays and Indians from Malaysia. Anaesth Intensive Care 2019; 32:250-5. [PMID: 15957725 DOI: 10.1177/0310057x0403200215] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Differences in sensitivity to anaesthetic drugs may exist among different ethnic groups. Allelic variants for drug metabolizing isoenzymes and pharmacokinetic differences may account for a variable response to some anaesthetic drugs. This study was designed to compare propofol consumption and recovery characteristics in four ethnic groups: Chinese, Malays, and Indians in Malaysia and Caucasians in Italy. Patients undergoing total intravenous anaesthesia with propofol and fentanyl were evaluated for propofol consumption and recovery time. The Bispectral Index (BIS) was used to maintain the same anaesthesia depth in all patients. The BIS value, the response to verbal stimuli and eye-opening time were used to assess recovery. After propofol discontinuation the BIS values returned to baseline in 11±4.2 min for Caucasians, in 12.5±5.1 min for Chinese, 15.9±6.3 min for Malays and 22.1±8.1 for Indians. Time to eye-opening was 11.63±4.2 min in Caucasians, 13.23±4.9 min in Chinese, 16.97±5.2 min in Malays and 22.3±6.6 min in Indians. The propofol consumption was significantly lower in Indians compared to the other three groups (P<0.01). The recovery of Indians was much slower compared to Chinese, Malays and Caucasians. The recovery time of Malays is significantly slower compared to Chinese and Caucasians. Differences in propofol consumption and recovery time were not significant between Chinese and Caucasians, but the ratio recovery time/propofol consumption was significantly lower in Caucasians compared to all the other groups.
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Chan YK, Wong WY. [Robotic head and neck surgery at the Chinese University of Hong Kong]. LIN CHUANG ER BI YAN HOU TOU JING WAI KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY, HEAD, AND NECK SURGERY 2018; 32:1056-1060. [PMID: 30550146 DOI: 10.13201/j.issn.1001-1781.2018.14.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Indexed: 11/12/2022]
Abstract
Introduction:Robotic surgery in the head and neck region has been used to approach many different areas within the head and neck region. Here we describe our experiences of its application at The Chinese University of Hong Kong.Methods:This is a retrospective review of all cases operated by the two authors since Jan 2015 at the Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong.Results:Twenty-four cases were performed with the da Vinci S or da Vinci Xi systems. Twenty-one cases were performed with the novel flexible robotic da Vinci SP system. There were no serious adverse events requiring a return to the operating room. Early results from the da Vinci SP have been previously published in seven patients that demonstrated the ability to reach the nasopharynx, oropharynx, hypopharynx, larynx and also retropharyngeal lymph nodes. There were no conversions to alternative surgical approaches. There were no serious adverse events or adverse events related to the use of this system.Discussion:In conclusion, through our experiences at The Chinese University of Hong Kong we have found the da Vinci robotic systems to be useful and safe in performing TORS and addressing pathologies in the neck through the retroauricular approach.
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Scuffham PA, Ball J, Horowitz JD, Wong C, Newton PJ, Macdonald P, McVeigh J, Rischbieth A, Emanuele N, Carrington MJ, Reid CM, Chan YK, Stewart S. Standard vs. intensified management of heart failure to reduce healthcare costs: results of a multicentre, randomized controlled trial. Eur Heart J 2018; 38:2340-2348. [PMID: 28531281 PMCID: PMC5843128 DOI: 10.1093/eurheartj/ehx259] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 04/27/2017] [Indexed: 12/28/2022] Open
Abstract
Aims To determine if an intensified form of heart failure management programme (INT-HF-MP) based on individual profiling is superior to standard management (SM) in reducing health care costs during 12-month follow-up (primary endpoint). Methods and results A multicentre randomized trial involving 787 patients (full analysis set) discharged from four tertiary hospitals with chronic HF who were randomized to SM (n = 391) or INT-HF-MP (n = 396). Mean age was 74 ± 12 years, 65% had HF with a reduced ejection fraction (31.4 ± 8.9%) and 14% were remote-dwelling. Study groups were well matched. According to Green, Amber, Red Delineation of rIsk And Need in HF (GARDIAN-HF) profiling, regardless of location, patients in the INT-HF-MP received a combination of face-to-face (home visits) and structured telephone support (STS); only 9% (`low risk') were designated to receive the same level of management as the SM group. The median cost in 2017 Australian dollars (A$1 equivalent to ∼EUR €0.7) of applying INT-HF-MP was significantly greater than SM ($152 vs. $121 per patient per month; P < 0.001), However, at 12 months, there was no difference in total health care costs for the INT-HF-MP vs. SM group (median $1579, IQR $644 to $3717 vs. $1450, IQR $564 to $3615 per patient per month, respectively). This reflected minimal differences in all-cause mortality (17.7% vs. 18.4%; P = 0.848) and recurrent hospital stay (18.6 ± 26.5 vs. 16.6 ± 24.8 days; P = 0.199) between the INT-HF-MP and SM groups, respectively. Conclusion During 12-months follow-up, an INT-HF-MP did not reduce healthcare costs or improve health outcomes relative to SM.
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Wong D, Chan YK, Bek T, Wilson I, Stefánsson E. Intraocular currents, Bernoulli's principle and non-drainage scleral buckling for rhegmatogenous retinal detachment. Eye (Lond) 2018; 32:213-221. [PMID: 29350687 DOI: 10.1038/eye.2017.312] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 11/30/2017] [Indexed: 11/09/2022] Open
Abstract
For many years, it is not fully understood how non-drainage scleral buckling surgery brings about spontaneous reattachment of the detached retina when retinal breaks remain open at the end of surgery. Various explanations have been put forward, but none more interesting than the effect of fluid currents associated with eye movements. One such explanation involved the physics of the Bernoulli's principle. Daniel Bernoulli was an eighteenth century Swiss mathematician and he described an equation based on the conservation of energy. The sum of pressure energy, potential energy and kinetic energy remains constant. Bernoulli's equation usually applies to closed system such as the flow of fluid through pipes. When fluid flows through a constriction, the speed of fluid increases, the kinetic energy increases. If there was no change in elevation (potential energy), then the increase in kinetic energy must be accompanied by a decrease in pressure energy. In ophthalmic surgery, the Bernoulli's effect is the basis for venturi pumps that drive vitrectomy and phacoemulsification machines. This essay expounds on how Bernoulli's effect might be relevant to scleral buckling for retinal detachment repair. In the era when vitrectomy is increasing the primary surgical operation for retinal detachment, the pervasive advice is to emphasise the importance of patient adopting head posture and remaining still postoperatively. The exception is non-drainage scleral buckling surgery. Early postoperative mobilisation may be vital to achieve reattachment.
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Stefánsson E, Chan YK, Bek T, Hardarson SH, Wong D, Wilson DI. Laws of physics help explain capillary non-perfusion in diabetic retinopathy. Eye (Lond) 2018; 32:210-212. [PMID: 29350688 DOI: 10.1038/eye.2017.313] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 12/03/2017] [Indexed: 01/09/2023] Open
Abstract
The purpose is to use laws of physics to elucidate the mechanisms behind capillary non-perfusion in diabetic retinopathy. In diabetic retinopathy, loss of pericytes weakens capillary walls and the vessel dilates. A dilated capillary has reduced resistance to flow, therefore increased flow in that vessel and decreased in adjoining capillaries. A preferential shunt vessel is thus formed from the dilated capillary and the adjacent capillaries become non-perfused. We apply the laws of Laplace and Hagen-Poiseuille to better understand the phenomena that lead to capillary non-perfusion. These laws of physics can give a foundation for physical or mathematical models to further elucidate this field of study. The law of Laplace predicts that a weaker vessel wall will dilate, assuming constant transmural pressure. The Hagen-Poiseuille equation for flow and the Ostwald-de Waele relationship for viscosity predict that a dilated vessel will receive a higher portion of the fluid flow than the adjoining capillaries. Viscosity will decrease in the dilated vessel, furthering the imbalance and resulting in a patch of non-perfused capillaries next to the dilated 'preferential' shunt vessel. Physical principles support or inspire novel hypotheses to explain poorly understood phenomena in ophthalmology. This thesis of pericyte death and capillary remodelling, which was first proposed by Cogan and Kuwabara, already agrees with histological and angiographical observations in diabetic retinopathy. We have shown that it is also supported by classical laws of physics.
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Sung HK, Chan YK, Han M, Jahng JWS, Song E, Danielson E, Berger T, Mak TW, Sweeney G. Lipocalin-2 (NGAL) Attenuates Autophagy to Exacerbate Cardiac Apoptosis Induced by Myocardial Ischemia. J Cell Physiol 2017; 232:2125-2134. [PMID: 27800610 DOI: 10.1002/jcp.25672] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 10/17/2016] [Indexed: 12/19/2022]
Abstract
Lipocalin-2 (Lcn2; also termed neutrophil gelatinase-associated lipocalin (NGAL)) levels correlate positively with heart failure (HF) yet mechanisms via which Lcn2 contributes to the pathogenesis of HF remain unclear. In this study, we used coronary artery ligation surgery to induce ischemia in wild-type (wt) mice and this induced a significant increase in myocardial Lcn2. We then compared wt and Lcn2 knockout (KO) mice and observed that wt mice showed greater ischemia-induced caspase-3 activation and DNA damage measured by TUNEL than Lcn2KO mice. Analysis of autophagy by LC3 and p62 Western blotting, LC3 immunohistochemistry and transmission electron microscopy (TEM) indicated that Lcn2 KO mice had a greater ischemia-induced increase in autophagy. Lcn2KO were protected against ischemia-induced cardiac functional abnormalities measured by echocardiography. Upon treating a cardiomyocyte cell line (h9c2) with Lcn2 and examining AMPK and ULK1 phosphorylation, LC3 and p62 by Western blot as well as tandem fluorescent RFP/GFP-LC3 puncta by immunofluorescence, MagicRed assay for lysosomal cathepsin activity and TEM we demonstrated that Lcn2 suppressed autophagic flux. Lcn2 also exacerbated hypoxia-induced cytochromc c release from mitochondria and caspase-3 activation. We generated an autophagy-deficient H9c2 cell model by overexpressing dominant-negative Atg5 and found significantly increased apoptosis after Lcn2 treatment. In summary, our data indicate that Lcn2 can suppress the beneficial cardiac autophagic response to ischemia and that this contributes to enhanced ischemia-induced cell death and cardiac dysfunction. J. Cell. Physiol. 232: 2125-2134, 2017. © 2016 Wiley Periodicals, Inc.
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Chan YK, El-Nezami H, Chen Y, Kinnunen K, Kirjavainen PV. Probiotic mixture VSL#3 reduce high fat diet induced vascular inflammation and atherosclerosis in ApoE(-/-) mice. AMB Express 2016; 6:61. [PMID: 27576894 PMCID: PMC5005234 DOI: 10.1186/s13568-016-0229-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 08/12/2016] [Indexed: 02/07/2023] Open
Abstract
Atherosclerosis results from chronic inflammation potentially caused by translocation of bacterial components from the oro-gastrointestinal tract to circulation. Specific probiotics have anti-inflammatory effects and may reduce bacterial translocation. We thereby tested whether a probiotic mixture with documented anti-inflammatory potential could reduce atherosclerosis. ApoE−/− mice were fed high fat diet alone or with VSL#3 or a positive control treatment, telmisartan or both for 12 weeks. All treatments reduced atherosclerotic plaques significantly compared to high fat diet alone. VSL#3 significantly reduced proinflammatory adhesion molecules and risk factors of plaque rupture, reduced vascular inflammation and atherosclerosis to a comparable extent to telmisartan; and VSL#3 treated mice had the most distinctly different intestinal microbiota composition from the control groups. Combining the VSL#3 and telmisartan brought no further benefits. Our findings showed the therapeutic potential of VSL#3 in reducing atherosclerosis and vascular inflammation.
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Chan YK, Budgett SC, MacGibbon AK, Quek SY, Kindleysides S, Poppitt SD. Small particle size lipid emulsions, satiety and energy intake in lean men. Physiol Behav 2016; 169:98-105. [PMID: 27890592 DOI: 10.1016/j.physbeh.2016.11.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/26/2016] [Accepted: 11/19/2016] [Indexed: 01/17/2023]
Abstract
Lipid emulsions have been proposed to suppress hunger and food intake. Whilst there is no consensus on optimal structural properties or mechanism of action, small particle size (small-PS) stable emulsions may have greatest efficacy. Fabuless®, a commercial lipid emulsion reported in some studies to decrease energy intake (EI), is a small-PS, 'hard' fat emulsion comprising highly saturated palm oil base (PS, 82nm). To determine whether small-PS dairy lipid emulsions can enhance satiety, firstly, we investigated 2 'soft' fat dairy emulsions generated using dairy and soy emulsifying agents (PS, 114nm and 121nm) and a non-emulsified dairy control. Secondly, we investigated a small-PS palmolein based 'hard' fat emulsion (fractionated palm oil, PS, 104nm) and non-emulsified control. This was a 6 arm, randomized, cross-over study in 18 lean men, with test lipids delivered in a breakfast meal: (i) Fabuless® emulsion (FEM); (ii) dairy emulsion with dairy emulsifier (DEDE); (iii) dairy emulsion with soy lecithin emulsifier (DESE); (iv) dairy control (DCON); (v) palmolein emulsion with dairy emulsifier (PEDE); (vi) palmolein control (PCON). Participants rated postprandial appetite sensations using visual analogue scales (VAS), and ad libitum energy intake (EI) was measured at a lunch meal 3.5h later. Dairy lipid emulsions did not significantly alter satiety ratings or change EI relative to dairy control (DEDE, 4035kJ; DESE, 3904kJ; DCON, 3985kJ; P>0.05) nor did palm oil based emulsion relative to non-emulsified control (PEDE, 3902 kJ; PCON, 3973kJ; P>0.05). There was no evidence that small-PS dairy lipid emulsions or commercial Fabuless altered short-term appetite or food intake in lean adults.
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Chan YK, Brar MS, Kirjavainen PV, Chen Y, Peng J, Li D, Leung FCC, El-Nezami H. High fat diet induced atherosclerosis is accompanied with low colonic bacterial diversity and altered abundances that correlates with plaque size, plasma A-FABP and cholesterol: a pilot study of high fat diet and its intervention with Lactobacillus rhamnosus GG (LGG) or telmisartan in ApoE -/- mice. BMC Microbiol 2016; 16:264. [PMID: 27821063 PMCID: PMC5100306 DOI: 10.1186/s12866-016-0883-4] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 10/29/2016] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Atherosclerosis appears to have multifactorial causes - microbial component like lipopolysaccharides (LPS) and other pathogen associated molecular patterns may be plausible factors. The gut microbiota is an ample source of such stimulants, and its dependent metabolites and altered gut metagenome has been an established link to atherosclerosis. In this exploratory pilot study, we aimed to elucidate whether microbial intervention with probiotics L. rhamnosus GG (LGG) or pharmaceuticals telmisartan (TLM) could improve atherosclerosis in a gut microbiota associated manner. METHODS Atherosclerotic phenotype was established by 12 weeks feeding of high fat (HF) diet as opposed to normal chow diet (ND) in apolipoprotein E knockout (ApoE-/-) mice. LGG or TLM supplementation to HF diet was studied. RESULTS Both LGG and TLM significantly reduced atherosclerotic plaque size and improved various biomarkers including endotoxin to different extents. Colonial microbiota analysis revealed that TLM restored HF diet induced increase in Firmicutes/Bacteroidetes ratio and decrease in alpha diversity; and led to a more distinct microbial clustering closer to ND in PCoA plot. Eubacteria, Anaeroplasma, Roseburia, Oscillospira and Dehalobacteria appeared to be protective against atherosclerosis and showed significant negative correlation with atherosclerotic plaque size and plasma adipocyte - fatty acid binding protein (A-FABP) and cholesterol. CONCLUSION LGG and TLM improved atherosclerosis with TLM having a more distinct alteration in the colonic gut microbiota. Altered bacteria genera and reduced alpha diversity had significant correlations to atherosclerotic plaque size, plasma A-FABP and cholesterol. Future studies on such bacterial functional influence in lipid metabolism will be warranted.
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Chan YK, Sung HK, Jahng JWS, Kim GHE, Han M, Sweeney G. Lipocalin-2 inhibits autophagy and induces insulin resistance in H9c2 cells. Mol Cell Endocrinol 2016; 430:68-76. [PMID: 27090568 DOI: 10.1016/j.mce.2016.04.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 04/05/2016] [Accepted: 04/13/2016] [Indexed: 01/08/2023]
Abstract
Lipocalin-2 (Lcn2; also known as neutrophil gelatinase associated lipocalin, NGAL) levels are increased in obesity and diabetes and associate with insulin resistance. Correlations exist between Lcn2 levels and various forms or stages of heart failure. Insulin resistance and autophagy both play well-established roles in cardiomyopathy. However, little is known about the impact of Lcn2 on insulin signaling in cardiomyocytes. In this study, we treated H9c2 cells with recombinant Lcn2 for 1 h followed by dose- and time-dependent insulin treatment and found that Lcn2 attenuated insulin signaling assessed via phosphorylation of Akt and p70S6K. We used multiple assays to demonstrate that Lcn2 reduced autophagic flux. First, Lcn2 reduced pULK1 S555, increased pULK1 S757 and reduced LC3-II levels determined by Western blotting. We validated the use of DQ-BSA to assess autolysosomal protein degradation and this together with MagicRed cathepsin B assay indicated that Lcn2 reduced lysosomal degradative activity. Furthermore, we generated H9c2 cells stably expressing tandem fluorescent RFP/GFP-LC3 and this approach verified that Lcn2 decreased autophagic flux. We also created an autophagy-deficient H9c2 cell model by overexpressing a dominant-negative Atg5 mutant and found that reduced autophagy levels also induced insulin resistance. Adding rapamycin after Lcn2 could stimulate autophagy and recover insulin sensitivity. In conclusion, our study indicated that acute Lcn2 treatment caused insulin resistance and use of gain and loss of function approaches elucidated a causative link between autophagy inhibition and regulation of insulin sensitivity by Lcn2.
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DeCoffe D, Quin C, Gill SK, Tasnim N, Brown K, Godovannyi A, Dai C, Abulizi N, Chan YK, Ghosh S, Gibson DL. Dietary Lipid Type, Rather Than Total Number of Calories, Alters Outcomes of Enteric Infection in Mice. J Infect Dis 2016; 213:1846-56. [PMID: 27067195 DOI: 10.1093/infdis/jiw084] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 02/18/2016] [Indexed: 12/19/2022] Open
Abstract
Dietary lipids modulate immunity, yet the means by which specific fatty acids affect infectious disease susceptibility remains unclear. Deciphering lipid-induced immunity is critical to understanding the balance required for protecting against pathogens while avoiding chronic inflammatory diseases. To understand how specific lipids alter susceptibility to enteric infection, we fed mice isocaloric, high-fat diets composed of corn oil (rich in n-6 polyunsaturated fatty acids [n-6 PUFAs]), olive oil (rich in monounsaturated fatty acids), or milk fat (rich in saturated fatty acids) with or without fish oil (rich in n-3 PUFAs). After 5 weeks of dietary intervention, mice were challenged with Citrobacter rodentium, and pathological responses were assessed. Olive oil diets resulted in little colonic pathology associated with intestinal alkaline phosphatase, a mucosal defense factor that detoxifies lipopolysaccharide. In contrast, while both corn oil and milk fat diets resulted in inflammation-induced colonic damage, only milk fat induced compensatory protective responses, including short chain fatty acid production. Fish oil combined with milk fat, unlike unsaturated lipid diets, had a protective effect associated with intestinal alkaline phosphatase activity. Overall, these results reveal that dietary lipid type, independent of the total number of calories associated with the dietary lipid, influences the susceptibility to enteric damage and the benefits of fish oil during infection.
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Cheung MY, Lai CL, Lam WHY, Lau JSK, Lee AKH, Yuen GG, Chan YK, Tsang WL. Trampoline-related injuries in Hong Kong. Hong Kong Med J 2016; 22:81-4. [PMID: 26845468 DOI: 10.12809/hkmj144411] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Shrestha S, Chan YK, Razali FN. Anesthetic Management for a Parturient with Facioscapulohumeral Muscular Dystrophy Undergoing Caesarean Section. NEPAL JOURNAL OF OBSTETRICS AND GYNAECOLOGY 2016. [DOI: 10.3126/njog.v10i2.14339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant muscle disorder characterized by progressive weakness and wasting of facial, shoulder girdle and upper arm muscles. Anesthetic management for the parturient with muscular dystrophy is very challenging for anesthesiologists because general as well as regional anesthesia may cause deleterious effect to the patient. We report a case of 28 years parturient with Facioscapulohumeral muscular dystrophy that underwent elective caesarean section under combined spinal epidural anesthesia. Intraoperative and postoperative period were uneventful however the motor block was prolonged. Regional anesthesia especially combined spinal epidural anesthesia can be safely used to provide anesthesia for caesarean section in patients with muscular dystrophy.
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Park M, Sabetski A, Kwan Chan Y, Turdi S, Sweeney G. Palmitate induces ER stress and autophagy in H9c2 cells: implications for apoptosis and adiponectin resistance. J Cell Physiol 2015; 230:630-9. [PMID: 25164368 DOI: 10.1002/jcp.24781] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 08/22/2014] [Indexed: 02/06/2023]
Abstract
The association between obesity and heart failure is well documented and recent studies have indicated that understanding the physiological role of autophagy will be of great significance. Cardiomyocyte apoptosis is one component of cardiac remodeling which leads to heart failure and in this study we used palmitate-treated H9c2 cells as an in vitro model of lipotoxicity to investigate the role of autophagy in cell death. Temporal analysis revealed that palmitate (100 μM) treatment induced a gradual increase of intracellular lipid accumulation as well as apoptotic cell death. Palmitate induced autophagic flux, determined via increased LC3-II formation and p62 degradation as well as by detecting reduced colocalization of GFP with RFP in cells overexpressing tandem fluorescent GFP/RFP-LC3. The increased level of autophagy indicated by these measures were confirmed using transmission electron microscopy (TEM). Upon inhibiting autophagy using bafilomycin we observed an increased level of palmitate-induced cell death assessed by Annexin V/PI staining, detection of active caspase-3 and MTT cell viability assay. Interestingly, using TEM and p-PERK or p-eIF2α detection we observed increased endoplasmic reticulum (ER) stress in response to palmitate. Autophagy was induced as an adaptive response against ER stress since it was sensitive to ER stress inhibition. Palmitate-induced ER stress also induced adiponectin resistance, assessed via AMPK phosphorylation, via reducing APPL1 expression. This effect was independent of palmitate-induced autophagy. In summary, our data indicate that palmitate induces autophagy subsequent to ER stress and that this confers a prosurvival effect against lipotoxicity-induced cell death. Palmitate-induced ER stress also led to adiponecin resistance.
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Cheung KM, Lam CW, Chan YK, Siu WK, Yong L. Atypical focal cortical dysplasia in a patient with Cowden syndrome. Hong Kong Med J 2015; 20:165-7. [PMID: 24714173 DOI: 10.12809/hkmj133863] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
A macrocephalic girl presented with generalised epilepsy due to focal cortical dysplasia. She later developed multiple hamartomatous lesions and was diagnosed to have Cowden syndrome. The diagnosis was confirmed by identification of a novel frameshift mutation in the PTEN gene of the patient.
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Vaithilingam RD, Safii SH, Baharuddin NA, Karen-Ng LP, Saub R, Ariffin F, Ramli H, Sharifuddin A, Hidayat MFH, Raman R, Chan YK, Rani NA, Rahim RA, Shahruddin N, Cheong SC, Bartold PM, Zain RB. Establishing and managing a periodontal biobank for research: the sharing of experience. Oral Dis 2014; 21:e62-9. [PMID: 24930489 DOI: 10.1111/odi.12267] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 05/12/2014] [Accepted: 06/08/2014] [Indexed: 12/30/2022]
Abstract
Periodontal bio-repositories, which allow banking of clinically validated human data and biological samples, provide an opportunity to derive biomarkers for periodontal diagnosis, prognosis and therapeutic activities which are expected to improve patient management. This article presents the establishing of the Malaysian Periodontal Database and Biobank System (MPDBS) which was initiated in 2011 with the aim to facilitate periodontal research. Partnerships were established with collaborating centres. Policies on specimen access, authorship and acknowledgement policies were agreed upon by all participating centres before the initiation of the periodontal biobank. Ethical approval for the collection of samples and data were obtained from institutional ethics review boards. A broad-based approach for informed consent was used, which covered areas related to quality of life impacts, genetics and molecular aspects of periodontal disease. Sample collection and processing was performed using a standardized protocol. Biobanking resources such as equipment and freezers were shared with the Malaysian Oral Cancer Database and Tissue Bank System (MOCDTBS). In the development of the MPDBS, challenges that were previously faced by the MOCDTBS were considered. Future challenges in terms of ethical and legal issues will be faced when international collaborations necessitate the transportation of specimens across borders.
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Shariffuddin II, Rai V, Chan YK, Muniandy RK. Safe delivery of two parturient women in severe metabolic acidosis. BMJ Case Rep 2014; 2014:bcr-2014-205135. [PMID: 24862427 DOI: 10.1136/bcr-2014-205135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Care of an acutely ill parturient is particularly difficult when we have to balance the needs of both mother and the fetus to survive. The literature suggests there should be emphasis on stabilising the mother's condition. In dealing with metabolic acidosis, however, we believe delivering the baby early might not only relieve the threat of the acidosis on the mother, it may be the only way to deliver a live baby. We report two parturient women with severe metabolic acidosis which was considerably reduced very soon after the delivery and how our timely delivery resulted in the birth of two neurologically intact babies.
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Chan YK, Estaki M, Gibson DL. Clinical consequences of diet-induced dysbiosis. ANNALS OF NUTRITION AND METABOLISM 2013; 63 Suppl 2:28-40. [PMID: 24217034 DOI: 10.1159/000354902] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Various disease states are associated with an imbalance of protective and pathogenic bacteria in the gut, termed dysbiosis. Current evidence reveals that dietary factors affect the microbial ecosystem in the gut. Changes to community structure of the intestinal microbiota are not without consequence considering the wide effects that the microbes have on both local and systemic immunity. The goal of this review is to give insight into the importance of gut microbiota in disease development and the possible therapeutic interventions in clinical settings. We introduce the complex tripartite relationship between diet, microbes and the gut epithelium. This is followed by a summary of clinical evidence of diet-induced dysbiosis as a contributing factor in the development of gastrointestinal diseases like inflammatory bowel disease, irritable bowel syndrome and colorectal cancer, as well as systemic diseases like obesity, diabetes, atherosclerosis and nonalcoholic fatty liver disease. Finally, the current dietary and microbial interventions to promote a healthy microbial profile will be reviewed.
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Hussain Khan Z, Chan YK. SAPS II, SAPS III versus markers of tissue oxygen delivery: discerning their role in predicting outcome for cardiopulmonary arrest. Minerva Anestesiol 2012; 78:1313-1315. [PMID: 23222997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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Li D, Tsang JYS, Peng J, Ho DHH, Chan YK, Zhu J, Lui VCH, Xu A, Lamb JR, Tam PKH, Chen Y. Adiponectin mediated MHC class II mismatched cardiac graft rejection in mice is IL-4 dependent. PLoS One 2012; 7:e48893. [PMID: 23155424 PMCID: PMC3498365 DOI: 10.1371/journal.pone.0048893] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 10/03/2012] [Indexed: 11/18/2022] Open
Abstract
Background Adiponectin regulates glucose and fatty-acid metabolism but its role in chronic graft rejection mediated by Th2 cytokines remains ill-defined. Methodology/Principal Findings Wild type and adiponectin-null mice were used as graft recipients in mouse MHC class II disparate cardiac transplantation (bm12 toB6) and the graft rejection was monitored. In adiponectin-null mice we observed that the cellular infiltrate of eosinophils, CD4+ and CD8+ T cells was reduced in grafts compared to the controls as was collagen deposition and vessel occlusion. A similar outcome was observed for skin transplants except that neutrophil infiltration was increased. Low levels of IL-4 were detected in the grafts and serum. The effect of adiponectin signaling on IL-4 expression was further investigated. Treatment with AMPK and p38 MAPK inhibitors blocked adiponectin enhanced T cell proliferation in mixed lymphocyte reactions. Inhibition of AMPK reduced eosinophil infiltration in skin grafts in wild type recipients and in contrast AMPK activation increased eosinophils in adiponectin-null recipients. The addition of adiponectin increased IL-4 production by the T cell line EL4 with augmented nuclear GATA-3 and phospho-STAT6 expression which were suppressed by knockdown of adiponectin receptor 1 and 2. Conclusions Our results demonstrate a direct effect of adiponectin on IL-4 expression which contributes to Th2 cytokine mediated rejection in mouse MHC class II histoincompatible transplants. These results add to our understanding of the interrelationship of metabolism and immune regulation and raise the possibility that AMPK inhibitors may be beneficial in selected types of rejection.
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