1.Role of PCSK9 Inhibitors in Patients with Familial Hypercholesterolemia
Brian TOMLINSON ; Nivritti Gajanan PATIL ; Manson FOK ; Christopher Wai Kei LAM
Endocrinology and Metabolism 2021;36(2):279-295
Patients with familial hypercholesterolemia (FH) are at high or very high risk for cardiovascular disease. Those with heterozygous FH (HeFH) often do not reach low-density lipoprotein cholesterol (LDL-C) targets with statin and ezetimibe therapy, and those with homozygous FH (HoFH) usually require additional lipid-modifying therapies. Drugs that inhibit proprotein convertase subtilisin/kexin type 9 (PCSK9) offer a novel approach to reduce LDL-C. The monoclonal antibodies, alirocumab and evolocumab, given by subcutaneous injection every 2 or 4 weeks produce reductions in LDL-C of 50% to 60% in patients with HeFH, allowing many of them to achieve their LDL-C goals. Patients with HoFH show a reduced and more variable LDL-C response, which appears to depend on residual LDL receptor activity, and those with receptor-negative mutations may show no response. Inclisiran is a long-acting small interfering RNA therapeutic agent that inhibits the synthesis of PCSK9. Subcutaneous doses of 300 mg can reduce LDL-C by more than 50% for at least 6 months and the responses in HeFH and HoFH patients are similar to those achieved with monoclonal antibodies. These PCSK9 inhibitors are generally well tolerated and they provide a new opportunity for effective treatment for the majority of patients with FH.
2.Role of PCSK9 Inhibitors in Patients with Familial Hypercholesterolemia
Brian TOMLINSON ; Nivritti Gajanan PATIL ; Manson FOK ; Christopher Wai Kei LAM
Endocrinology and Metabolism 2021;36(2):279-295
Patients with familial hypercholesterolemia (FH) are at high or very high risk for cardiovascular disease. Those with heterozygous FH (HeFH) often do not reach low-density lipoprotein cholesterol (LDL-C) targets with statin and ezetimibe therapy, and those with homozygous FH (HoFH) usually require additional lipid-modifying therapies. Drugs that inhibit proprotein convertase subtilisin/kexin type 9 (PCSK9) offer a novel approach to reduce LDL-C. The monoclonal antibodies, alirocumab and evolocumab, given by subcutaneous injection every 2 or 4 weeks produce reductions in LDL-C of 50% to 60% in patients with HeFH, allowing many of them to achieve their LDL-C goals. Patients with HoFH show a reduced and more variable LDL-C response, which appears to depend on residual LDL receptor activity, and those with receptor-negative mutations may show no response. Inclisiran is a long-acting small interfering RNA therapeutic agent that inhibits the synthesis of PCSK9. Subcutaneous doses of 300 mg can reduce LDL-C by more than 50% for at least 6 months and the responses in HeFH and HoFH patients are similar to those achieved with monoclonal antibodies. These PCSK9 inhibitors are generally well tolerated and they provide a new opportunity for effective treatment for the majority of patients with FH.
3.MTBSTFA derivatization-LC-MS/MS approach for the quantitative analysis of endogenous nucleotides in human colorectal carcinoma cells
Huixia ZHANG ; Yan LI ; Zheng LI ; Wai-Kei-Christopher LAM ; Peng ZHU ; Caiyun WANG ; Hua ZHOU ; Wei ZHANG
Journal of Pharmaceutical Analysis 2022;12(1):77-86
Endogenous ribonucleotides(RNs)and deoxyribonucleotides(dRNs)are important metabolites related to the pathogenesis of many diseases.In light of their physiological and pathological significances,a novel and sensitive pre-column derivatization method with N-(t-butyldimethylsilyl)-N-methyltri-fluoroacetamide(MTBSTFA)was developed to determine RNs and dRNs in human cells using high-performance liquid chromatography tandem mass spectrometry(HPLC-MS/MS).A one-step extraction of cells with 85%methanol followed by a simple derivatization reaction within 5 min at room temper-ature contributed to shortened analysis time.The derivatives of 22 nucleoside mono-,di-and tri-phosphates were retained on the typical Cig column and eluted by ammonium acetate and acetonitrile in 9 min.Under these optimal conditions,good linearity was achieved in the tested calibration ranges.The lower limit of quantitation(LLOQ)was determined to be 0.1-0.4 μM for the tested RNs and 0.001-0.1 μM for dRNs.In addition,the precision(CV)was<15%and the RSD of stability was lower than 10.4%.Furthermore,this method was applied to quantify the endogenous nucleotides in human colorectal carcinoma cell lines HCT116 exposed to 10-hydroxycamptothecin.In conclusion,our method has proven to be simple,rapid,sensitive,and reliable.It may be used for specific expanded studies on intracellular pharmacology in vitro.
4.Changes in main causes of death in Macao residents from 1986 - 2006.
Man-si CHAN ; Qing CHEN ; Christopher Wai-kei LAM
Chinese Medical Journal 2013;126(9):1661-1666
BACKGROUNDSince Macao's return of sovereignty to China in December 1999, the life style of Macao residents has changed. The aim of this study was to investigate changes of death patterns in Macao residents from 1986 to 2006 in order to identify the trends and patterns of major public health problems, which could provide the guidance for developing public health policies.
METHODSA retrospective study was conducted for this investigation. Research data were collected from official websites and statistical yearbooks and classified by the International Classification of Diseases (ICD)-9.
RESULTSIt was observed that mortality from the three major causes of (1) infectious, maternal and childhood diseases, (2) chronic non-communicable diseases, and (3) injury and poisoning were 17.7, 298.2 and 26.0 per 100 000, respectively. The largest decrease in death rate over the 21-year study-period was from infectious, maternal and childhood diseases (62.5%). The highest mortality rate was ischemic heart diseases (37.0%). The largest increase in mortality rate was lung cancer (46.9%).
CONCLUSIONSMortality rate of Macao residents progressively decreased, but the constituent ratio of death from chronic non-communicable diseases was increasing. The mortality rate of lung cancer was clearly ascending, so emphasis should be put on tertiary prevention in future.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Cause of Death ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Infant, Newborn ; Macau ; epidemiology ; Male ; Middle Aged ; Neoplasms ; mortality ; Primary Health Care ; Retrospective Studies ; Time Factors
5.Investigation into perturbed nucleoside metabolism and cell cycle for elucidating the cytotoxicity effect of resveratrol on human lung adenocarcinoma epithelial cells.
Zheng LI ; Qian-Qian CHEN ; Christopher Wai Kei LAM ; Jian-Ru GUO ; Wei-Jia ZHANG ; Cai-Yun WANG ; Vincent Kam Wai WONG ; Mei-Cun YAO ; Wei ZHANG
Chinese Journal of Natural Medicines (English Ed.) 2019;17(8):608-615
In an effort to understand the molecular events contributing to the cytotoxicity activity of resveratrol (RSV), we investigated its effects on human lung adenocarcinoma epithelial cell line A549 at different concentrations. Cellular nucleoside metabolic profiling was determined by an established liquid chromatography-mass spectrometry method in A549 cells. RSV resulted in significant decreases and imbalances of deoxyribonucleoside triphosphates (dNTPs) pools suppressing subsequent DNA synthesis. Meanwhile, RSV at high concentration caused significant cell cycle arrest at S phase, in which cells required the highest dNTPs supply than other phases for DNA replication. The inhibition of DNA synthesis thus blocked subsequent progression through S phase in A549 cells, which may partly contribute to the cytotoxicity effect of RSV. However, hydroxyurea (HU), an inhibitor of RNR activity, caused similar dNTPs perturbation but no S phase arrest, finally no cytotoxicity effect. Therefore, we believed that the dual effect of high concentration RSV, including S phase arrest and DNA synthesis inhibition, was required for its cytotoxicity effect on A549 cells. In summary, our results provided important clues to the molecular basis for the anticancer effect of RSV on epithelial cells.