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Kwok T, Khoo CC, Leung J, Kwok A, Qin L, Woo J, Leung PC. Predictive values of calcaneal quantitative ultrasound and dual energy X ray absorptiometry for non-vertebral fracture in older men: results from the MrOS study (Hong Kong). Osteoporos Int 2012; 23:1001-6. [PMID: 21528361 DOI: 10.1007/s00198-011-1634-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 03/02/2011] [Indexed: 10/18/2022]
Abstract
UNLABELLED Calcaneal QUS is comparable to DXA in predicting non-vertebral fractures in older Chinese men. INTRODUCTION The predictive values of calcaneal quantitative ultrasound (QUS) and dual-energy X-ray absorptiometry (DXA) for non-vertebral fractures in older Chinese men were examined. METHODS One thousand nine hundred twenty-one Chinese men aged 65-92 years had calcaneal QUS and axial DXA bone mineral density (BMD) measurements. The incidence of non-vertebral fractures was documented. Cox regression and receiver operating curve (ROC) analysis were used to examine the associations of QUS parameters and BMD with the incidence of non-vertebral fractures. RESULTS The duration of follow-up was (mean ± SD) 6.5 ± 1.7 years. One hundred thirty-one non-vertebral fractures were recorded, 71 of which were major fragility fractures. Broadband ultrasound attenuation (BUA) and quantitative ultrasound index (QUI) were significantly associated with non-vertebral fractures and major fragility fractures, with age and fracture history-adjusted hazard ratio (95% CI) of 1.23 (1.03, 1.47) and 1.32 (1.10, 1.59) per standard deviation reduction, respectively, for non-vertebral fractures; 1.32 (1.04, 1.68) and 1.43 (1.11, 1.84), respectively, for major fragility fractures. Age and fracture history-adjusted areas under ROC curves of hip or spine BMDs were significantly greater than that of BUA or QUI in predicting major fragility fractures, but not in predicting all non-vertebral fractures. The addition of BUA or QUI had no effect on AUCs of total hip BMD alone. CONCLUSIONS The ability of calcaneal QUS to predict non-vertebral fractures was comparable to that of axial BMD by DXA, but was inferior to BMD in predicting major fragility fractures in older Chinese men.
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Ren JW, Chan KM, Lai PKK, Lau CBS, Yu H, Leung PC, Fung KP, Yu WFX, Cho CH. Extracts from Radix Astragali and Radix Rehmanniae promote keratinocyte proliferation by regulating expression of growth factor receptors. Phytother Res 2012; 26:1547-54. [PMID: 22359405 DOI: 10.1002/ptr.4615] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 01/06/2012] [Accepted: 01/09/2012] [Indexed: 02/04/2023]
Abstract
Chinese herbal medicine has long been used as a treatment for wounds. However, the underlying cellular and molecular mechanisms remain largely unknown. In this study it was shown that the proliferation of keratinocytes, which is known to play an important role in wound healing as the major cell type in the epidermis, was promoted by three herbal extracts/natural compounds: NF3 (an extract from the mixture of Radix Astragali (RA) and Radix Rehmanniae (RR) in the ratio of 2:1), stachyose (an isolated compound from Radix Rehmanniae) and extract P2-2 (a sub-fraction from the extract of Radix Astragali). The effect of the herbal extracts/natural compounds on the growth of keratinocytes was not influenced by a high glucose level, a condition similar to diabetic patients who usually suffer from diabetic foot ulcers. Real time RT-PCR results showed that the expression of epidermal growth factor (EGF) receptor, but not transforming growth factor-β (TGF-β) receptor, was up-regulated by NF3. Moreover, treatments with the EGF receptor kinase inhibitor AG1478 and the MEK inhibitor U0126 resulted in the diminishment of the effect of the three herbal extracts/natural compounds on keratinocyte proliferation, indicating that EGF receptor might have a significant role in this action. This study has further elucidated the molecular mechanism under which herbal extracts/natural compounds exert their effects on the wound healing process.
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Deng Y, Ng ESK, Yeung JHK, Kwan YW, Lau CBS, Koon JCM, Zhou L, Zuo Z, Leung PC, Fung KP, Lam FFY. Mechanisms of the cerebral vasodilator actions of isoflavonoids of Gegen on rat isolated basilar artery. JOURNAL OF ETHNOPHARMACOLOGY 2012; 139:294-304. [PMID: 22120017 DOI: 10.1016/j.jep.2011.11.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 09/12/2011] [Accepted: 11/12/2011] [Indexed: 05/31/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Gegen (root of Pueraria lobata) is used in traditional Chinese medicine for treatment of cardiovascular diseases. In this study, the relaxant actions of three of its isoflavonoids; puerarin, daidzein, and daidzin, were investigated on rat-isolated cerebral basilar artery. MATERIALS AND METHODS Rat basilar artery rings were precontracted with 100 nM U46619. Involvement of endothelium-dependent mechanisms was investigated by mechanical removal of the endothelium and inhibitors of nitric oxide synthase (NOS) and cyclooxygenase (COX) enzymes. Adenylyl cyclase- and guanylyl cyclase-dependent pathways were investigated using their respective inhibitors 9-(tetrahydro-2-furanyl)-9H-purine-6-amine (SQ22536) and 1H-[1,2,4]oxadiazolo [4,3-[alpha]]-quinoxalin-1-one (ODQ). K(+) channels were investigated by pretreatment of the artery rings with various K(+) channel inhibitors, and Ca(2+) channels were investigated in artery rings incubated with Ca(2+)-free buffer and primed with 100 nM U46619 for 5 min prior to adding CaCl(2) to elicit contraction. RESULTS Puerarin, daidzein, and daidzin produced concentration-dependent relaxation of the artery rings with concentration that produced 50% inhibition (IC(50)) of 304 ± 49 μM, 20 ± 7 μM, and 140 ± 21 μM, respectively. Removal of the endothelium produced no change on their vasorelaxant responses except the maximum response (I(max)) to puerarin was inhibited by 28%. The NOS inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME; 100 μM) also produced 45% inhibition on the puerarin-induced vasorelaxant response, but not the COX inhibitor flurbiprofen (10 μM). SQ22536 (100 μM) and ODQ (100μM) did not affect the vasodilator responses to puerarin, daidzein and daidzin, but glibenclamide (1μM), tetraethylammonium (TEA, 100mM) or a combination of K(+) channel inhibitors (100nM iberiotoxin+1mM 4-aminopyridine+100 μM barium chloride+1 μM glibenclamide+100mM TEA) reduced their I(max). The contractile response to CaCl(2) was attenuated by 61% and 34% in the presence of daidzein and daidzin, respectively, whereas, puerarin did not significantly affect the contraction. CONCLUSIONS The vasorelaxant action of daidzein and daidzin involved opening of K(+) channels and inhibition of Ca(2+) influx in the vascular smooth muscle cells. There is no evidence supporting involvement of endothelium-derived relaxing factors (EDRFs) in their actions. In contrast, puerarin produced vasodilatation via an endothelium-dependent mechanism involving nitric oxide production and an endothelium-independent pathway mediated by the opening of K(+) channels. The cerebral vasodilator activities of all these three isoflavonoids may be beneficial to patients with obstructive cerebrovascular diseases.
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Koon CM, Woo KS, Leung PC, Fung KP. Salviae Miltiorrhizae Radix and Puerariae Lobatae Radix herbal formula mediates anti-atherosclerosis by modulating key atherogenic events both in vascular smooth muscle cells and endothelial cells. JOURNAL OF ETHNOPHARMACOLOGY 2011; 138:175-183. [PMID: 21924338 DOI: 10.1016/j.jep.2011.08.073] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 08/03/2011] [Accepted: 08/31/2011] [Indexed: 05/31/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Salviae Miltiorrhizae Radix (Danshen) and Puerariae Lobatae Radix (Gegen) are principal herbs have long been used in combination for treating cardiovascular disease. AIMS OF STUDY Danshen and Gegen in the ratio of 7:3 (DGW) have significantly reduced the carotid intimal-media thickening (IMT) in patients in our previous clinical study. In the present study, we have demonstrated the mechanisms on IMT reduction by investigating its key processes on both vascular smooth muscle cell (vSMC) and endothelial cells. MATERIALS AND METHODS The anti-proliferative effects of DGW on platelet-derived growth factor (PDGF) induced vSMC proliferation were studied by cell proliferation, cell cycle distribution, p-ERK and cyclin D expression level. The anti-migratory effect of DGW was investigated by using transwell apparatus. For human umbilical endothelial cells (HUVEC), the inhibitory effects of DGW on TNF-alpha induced cell adhesion, cell adhesion molecules expression, MCP-1 and IL-6 production were investigated. RESULTS DGW significantly inhibited A7r5 proliferation and exhibited G1/S cell cycle arrest by suppressing both p-ERK and cyclin D expression. Moreover, DGW showed anti-migratory effect against PDGF-induced A7r5 migration. In addition, DGW inhibited the cell adhesion as well as the expression of ICAM-1 and VCAM-1, the production of MCP-1 but not IL-6 in TNF-α stimulated HUVECs. CONCLUSIONS Our study provided strong scientific evidence on IMT reduction in patients by modulating the key atherogenic events in both vSMC and endothelial cells.
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MESH Headings
- Atherosclerosis/metabolism
- Atherosclerosis/prevention & control
- Cell Physiological Phenomena/drug effects
- Cell Proliferation/drug effects
- Chemokine CCL2/metabolism
- Cyclin D/metabolism
- Drugs, Chinese Herbal/pharmacology
- Drugs, Chinese Herbal/therapeutic use
- Endothelial Cells/metabolism
- Endothelial Cells/pathology
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Human Umbilical Vein Endothelial Cells
- Humans
- Intercellular Adhesion Molecule-1/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Phytotherapy
- Plant Roots
- Pueraria
- Salvia miltiorrhiza
- Tunica Intima/cytology
- Tunica Intima/drug effects
- Tunica Intima/metabolism
- Tunica Media/cytology
- Tunica Media/drug effects
- Tunica Media/metabolism
- Vascular Cell Adhesion Molecule-1/metabolism
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Ng CF, Koon CM, Cheung DWS, Lam MY, Leung PC, Lau CBS, Fung KP. The anti-hypertensive effect of Danshen (Salvia miltiorrhiza) and Gegen (Pueraria lobata) formula in rats and its underlying mechanisms of vasorelaxation. JOURNAL OF ETHNOPHARMACOLOGY 2011; 137:1366-1372. [PMID: 21855622 DOI: 10.1016/j.jep.2011.08.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 08/01/2011] [Accepted: 08/02/2011] [Indexed: 05/31/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Radix Salviae miltiorrhizae (Danshen) and Radix Puerariae lobatae (Gegen) have long been used in traditional Chinese Medicine and serve as the principal herbs in treating cardiovascular disease. AIMS OF THE STUDY In the present study, an aqueous extract comprising Danshen and Gegen in the ratio of 7:3 (DG) was investigated for its anti-hypertension in vivo and vasodilative activities ex vivo. MATERIALS AND METHODS The anti-hypertensive effect of DG extract was investigated in spontaneously hypertensive rat (SHR) by measuring systolic blood pressure (SBP). Oral administration of DG extract was started at age of 6 weeks and 14 weeks for the preventive and therapeutic studies, respectively. Blood pressure was measured by tail-cuff method biweekly for 12 weeks. The ex vivo vasodilative activities of DG extract, its dependency on endothelium and the involvement of nitric oxide, prostacyclin and potassium channels were investigated using isolated rat aorta ring in organ bath. RESULTS For in vivo study, systolic blood pressure was significantly reduced in DG extract-treated groups (90.2 and 300 mg/kg) as compared with the SHR control in both preventive and therapeutic studies. However, DG extract was unable to suppress or delay the onset of hypertension in the preventive study. For ex vivo study, the results showed that DG extract induced a concentration-dependent relaxation in aorta and persisted response was observed with the removal of endothelium. Besides, pretreatment with a non-selective potassium channel inhibitor tetraethylammonium (TEA) also significantly inhibited DG extract-induced vasodilation. Further investigations on specific potassium channel blockers revealed that ATP-sensitive potassium (K(ATP)) channel inhibitor glibenclamide, inward rectifier potassium (Kir) inhibitor barium chloride and voltage-dependent potassium (K(v)) channel inhibitor 4-aminopyridine, but not BK(Ca) channel inhibitor iberiotoxin, exerted significant inhibition on DG extract-induced vasodilation. CONCLUSIONS The results of in vivo SHR animal model suggested that DG aqueous extract possessed blood pressure lowering effect on both pre- and post-hypertensive rats, which could be explained by its endothelium-independent vasodilation via the opening of K(ATP), Kir and K(v) channels.
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MESH Headings
- Administration, Oral
- Animals
- Antihypertensive Agents/administration & dosage
- Antihypertensive Agents/isolation & purification
- Antihypertensive Agents/pharmacology
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/metabolism
- Aorta, Thoracic/physiopathology
- Blood Pressure/drug effects
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Drugs, Chinese Herbal/administration & dosage
- Drugs, Chinese Herbal/isolation & purification
- Drugs, Chinese Herbal/pharmacology
- Epoprostenol/metabolism
- Hypertension/drug therapy
- Hypertension/metabolism
- Hypertension/physiopathology
- Hypertension/prevention & control
- KATP Channels/drug effects
- KATP Channels/metabolism
- Male
- Nitric Oxide/metabolism
- Plants, Medicinal
- Potassium Channel Blockers/pharmacology
- Potassium Channels, Inwardly Rectifying/drug effects
- Potassium Channels, Inwardly Rectifying/metabolism
- Potassium Channels, Voltage-Gated/drug effects
- Potassium Channels, Voltage-Gated/metabolism
- Pueraria/chemistry
- Rats
- Rats, Inbred SHR
- Rats, Inbred WKY
- Rats, Sprague-Dawley
- Salvia miltiorrhiza/chemistry
- Time Factors
- Vasodilation/drug effects
- Vasodilator Agents/administration & dosage
- Vasodilator Agents/isolation & purification
- Vasodilator Agents/pharmacology
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Li L, Tang LY, Man GCW, Yeung BHY, Lau CBS, Leung PC, Wang CC. Potential reproductive toxicity of Largehead Atractylodes Rhizome, the most commonly used Chinese medicine for threatened miscarriage. Hum Reprod 2011; 26:3280-8. [PMID: 21984574 DOI: 10.1093/humrep/der335] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Largehead Atractylodes Rhizome (LAR) is the most commonly used Chinese medicine to prevent early pregnancy loss due to threatened miscarriage. However, its safety profile during pregnancy is still not available. Here we aimed to identify the potential adverse effects of LAR on embryo-fetal development as well as prenatal and post-natal growth. METHODS Pregnant mice, rats and rabbits were orally administered with LAR extracts in various doses (from 1×, 2×, 3× and up to 6× clinical doses) at different gestational periods (implantation, gastrulation, organogenesis, maturation and whole gestation). Maternal effects on weight loss, implantation failure and fetal resorption and perinatal effects on developmental delay, growth restriction and congenital malformations were studied. RESULTS In mice, with early LAR exposure, a significant decrease in fetal growth parameters and a significant increase in post-implantation loss were identified. With late LAR exposure, significant increases in gestational duration as well as prenatal and post-natal mortality were found. At high clinical doses, congenital skeletal malformations were recorded. In rabbits, fetal resorption, hydrops fetalis and short ear anomaly were observed. No significant adverse effects were found in rats. CONCLUSIONS Potential reproductive toxicity of LAR in pregnant animals was identified within the clinical dose. Caution should be taken in clinical applications of LAR during pregnancy.
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Chan BCL, Ip M, Lau CBS, Lui SL, Jolivalt C, Ganem-Elbaz C, Litaudon M, Reiner NE, Gong H, See RH, Fung KP, Leung PC. Synergistic effects of baicalein with ciprofloxacin against NorA over-expressed methicillin-resistant Staphylococcus aureus (MRSA) and inhibition of MRSA pyruvate kinase. JOURNAL OF ETHNOPHARMACOLOGY 2011; 137:767-773. [PMID: 21782012 DOI: 10.1016/j.jep.2011.06.039] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 06/20/2011] [Accepted: 06/25/2011] [Indexed: 05/31/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Baicalein, the active constituent derived from Scutellaria baicalensis Georgi., has previously been shown to significantly restore the effectiveness of β-lactam antibiotics and tetracycline against methicillin-resistant Staphylococcus aureus (MRSA). With multiple therapeutic benefits, the antibacterial actions of baicalein may also be involved in overcoming other bacterial resistance mechanisms. The aim of the present study was to further investigate antibacterial activities of baicalein in association with various antibiotics against selected Staphylococcus aureus strains with known specific drug resistance mechanisms. MATERIAL AND METHODS A panel of clinical MRSA strains was used for further confirmation of the antibacterial activities of baicalein. The effect of baicalein on inhibiting the enzymatic activity of a newly discovered MRSA-specific pyruvate kinase (PK), which is essential for Staphylococcus aureus growth and survival was also examined. RESULTS In the checkerboard dilution test and time-kill assay, baicalein at 16 μg/ml could synergistically restore the antibacterial actions of ciprofloxacin against the NorA efflux pump overexpressed SA-1199B, but not with the poor NorA substrate, pefloxacin. Moreover, synergistic effects were observed when baicalein was combined with ciprofloxacin against 12 out of 20 clinical ciprofloxacin resistant strains. For MRSA PK studies, baicalein alone could inhibit the enzymatic activity of MRSA PK in a dose-dependent manner. CONCLUSION Our results demonstrated that baicalein could significantly reverse the ciprofloxacin resistance of MRSA possibly by inhibiting the NorA efflux pump in vitro. The inhibition of MRSA PK by baicalein could lead to a deficiency of ATP which might further contribute to the antibacterial actions of baicalein against MRSA.
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Khoo CC, Woo J, Leung PC, Kwok A, Kwok T. Determinants of bone mineral density in older postmenopausal Chinese women. Climacteric 2011; 14:378-83. [DOI: 10.3109/13697137.2010.548566] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Fung KP, Leung PC, Tsui KWS, Wan CCD, Wong KB, Waye MYM, Au WNS, Wong CK, Lam WKC, Lau BSC. Immunomodulatory activities of the herbal formula Kwan Du Bu Fei Dang in healthy subjects: a randomised, double-blind, placebo-controlled study. Hong Kong Med J 2011; 17 Suppl 2:41-43. [PMID: 21368336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
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Lau KM, Fu LH, Wong YL, Lau CP, Wong CW, Cheng L, Lau CBS, Ooi VEC, Chan PKS, Fung KP, Hui M, Leung PC. Efficacy and active components of herbal extracts on the treatment of tinea pedis. Hong Kong Med J 2011; 17 Suppl 2:44-47. [PMID: 21368337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
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Hon KLE, Leung TF, Ng PC, Lam MCA, Kam WYC, Wong KY, Lee KCK, Sung RYT, Cheng KF, Fok TF, Fung KP, Leung PC. Therapeutic effect and safety of a traditional Chinese medicine for atopic dermatitis in children: a randomised, double-blind, placebo-controlled study. Hong Kong Med J 2011; 17 Suppl 2:38-40. [PMID: 21368335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
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37
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Wang YXJ, Griffith JF, Ma HT, Kwok AWL, Leung JCS, Yeung DKW, Ahuja AT, Leung PC. Relationship between gender, bone mineral density, and disc degeneration in the lumbar spine: a study in elderly subjects using an eight-level MRI-based disc degeneration grading system. Osteoporos Int 2011; 22:91-6. [PMID: 20352410 DOI: 10.1007/s00198-010-1200-y] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Accepted: 02/08/2010] [Indexed: 11/29/2022]
Abstract
UNLABELLED The study cohort comprised 196 females and 163 males. Lumbar spine bone mineral density (BMD) and magnetic resonance imaging (MRI) were acquired. Females had more severe disc degeneration than males. Lumbar spine lower BMD was associated with less severe disc degeneration. Lumbar disc spaces were more likely to be narrower when vertebral BMD was higher. INTRODUCTION The purpose of this paper is to study the relationship between gender, BMD, and disc degeneration in the lumbar spine. METHODS The study cohort comprised 196 females and 163 males (age range 67-89 years) with no age difference between the two groups. Lumbar spine BMD was measured with dual X-ray densitometry, and MRI was acquired at 1.5 T. A subgroup of 48 males had additional lumbar vertebral quantitative computerized tomography densitometry. Lumbar disc degeneration was assessed using a MRI-based eight-level grading system. RESULTS Female subjects had more severe disc degeneration than male subjects. After removing age effect, a positive trend was observed between T-score and severity of lumbar disc degeneration. This was significant in female subjects while not significant in male subjects. Lumbar disc spaces were more likely to be narrowed when vertebral BMD was higher. These observations were more significant in the midlumbar region (L3/4 and L4/5) and less so at the thoracolumbar junction. CONCLUSION Female subjects tended to have slightly more severe lumbar disc degeneration than male subjects. Lower lumbar spine BMD was associated with less severe disc degeneration.
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Pan L, Leung PC, Gu JD. A new ColE1-like plasmid group revealed by comparative analysis of the replication proficient fragments of Vibrionaceae plasmids. J Microbiol Biotechnol 2010; 20:1163-78. [PMID: 20798577 DOI: 10.4014/jmb.1003.03007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Plasmids play important roles in horizontal gene transfer among Vibrionaceae, but surprisingly little is known about their replication and incompatibility systems. In this study, we successfully developed a bioinformatics-assisted strategy of experimental identification of 7 Vibrio plasmid replicons. Comparative sequences analysis of the 7 Vibrio plasmid replicons obtained in this study together with 8 published Vibrionaceae plasmid sequences revealed replication participating elements involved in the ColE1-mode of replication initiation and regulation. Like plasmid ColE1, these Vibrionaceae plasmids encode two RNA species (the primer RNA and the antisense RNA) for replication initiation and regulation and, as a result the 15 Vibrionaceae plasmids were designated as ColE1-like Vibrionaceae (CLV) plasmids. Two subgroups were obtained for the 15 CLV plasmids based on comparison of replicon organization and phylogenetic analysis of replication regions. Coexistence of CLV plasmids has been demonstrated by direct sequencing analysis and southern hybridization, strongly suggesting that the incompatibility of CLV plasmids is determined mainly by the RNAI species like the ColE1-like plasmids. Sequences resembling the conserved Xer recombination sites were also identified on the CLV plasmids, indicating that the CLV plasmids probably use the host site-specific recombination system for multimer resolution like that used by ColE1-like plasmids. All the results indicated that the 15 plasmids form a new ColE1-like group, providing basis for rapid characterization and classification of Vibrionaceae plasmids.
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Lee JSW, Auyeung TW, Leung J, Kwok T, Leung PC, Woo J. The effect of diabetes mellitus on age-associated lean mass loss in 3153 older adults. Diabet Med 2010; 27:1366-71. [PMID: 21059088 PMCID: PMC3059762 DOI: 10.1111/j.1464-5491.2010.03118.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
AIMS Diabetes mellitus may be associated with excessive lean mass loss. Other diabetes-related conditions may also play a role. We assessed body composition changes associated with diabetes in older adults with adjustment for diabetes-related co-morbidities. METHODS Three thousand, one hundred and fifty-three community-living adults aged ≥ 65 years were examined for lifestyle factors, diabetes-related medical conditions and body composition by dual energy X-ray absorptiometry at baseline and 4 years later. Body composition changes were compared between participants with diabetes and those without diabetes. Multivariate linear regression was used to examine the relationship between appendicular lean mass loss and confounders. RESULTS Appendicular lean mass loss in men with diabetes was two times that of men without diabetes (-1.5% in 'no diabetes' vs. -3.0% in 'diabetes') and in women with diabetes was 1.8 times that of those without diabetes (-1.9% in 'no diabetes' vs. -3.4% in 'diabetes') over 4 years. Men with diabetes also had higher total body mass loss and higher total body fat loss than men without diabetes. Women with diabetes had higher total body mass loss but total body fat loss was similar. After adjusting for age, body mass index, diabetes-related conditions, lifestyle factors and total body mass loss, diabetes remained an independent predictor of appendicular lean mass loss in both men and women. CONCLUSION Diabetes was associated with higher body mass loss and higher appendicular lean mass loss in older adults. In men, diabetes was also associated with total body fat loss.
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Nam HS, Shin MH, Zmuda JM, Leung PC, Barrett-Connor E, Orwoll ES, Cauley JA. Race/ethnic differences in bone mineral densities in older men. Osteoporos Int 2010; 21:2115-23. [PMID: 20204598 PMCID: PMC2974925 DOI: 10.1007/s00198-010-1188-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Accepted: 01/15/2010] [Indexed: 11/24/2022]
Abstract
SUMMARY BMD was compared across race/ethnic groups. There were substantial race/ethnic differences in BMD even within African or Asian origin. Additional adjustment for body size greatly attenuated or reversed the differences between US Caucasian men vs Asian men. It illustrates the role of body size on the difference between these groups. INTRODUCTION There is insufficient epidemiologic information about men's bone mineral density (BMD) levels across race/ethnic groups and geographic locations. METHODS In a cross-sectional design, we compared BMD in older men across seven race/ethnic groups in four countries. Femoral neck, total hip, and lumbar spine BMD were measured in men (age 65 to 78 years) from the Osteoporotic Fractures in Men (MrOS) Study (4,074 Caucasian, 208 African-American, 157 Asian, and 116 Hispanic men in USA), Tobago Bone Health Study (422 Afro-Caribbean men), MrOS Hong Kong Study (1,747 Hong Kong Chinese men), and the Namwon Study (1,079 South Korean men). BMD was corrected according to the cross-site calibration results for all scanners. RESULTS When compared with US Caucasian men, Afro-Caribbean and African-American men had, respectively, 8-20% and 6-11% higher age-adjusted mean BMD at all three bone sites. Hip BMD was similar in US Caucasian and Hispanic men, US Asian, Hong Kong Chinese, and Korean men had 3-14% lower BMD at all bone sites except femoral neck in Korean men. Additional adjustment for weight and height greatly attenuated or reversed the differences between US Caucasian men vs Asian men including US Asian, Hong Kong Chinese, and South Korean men. Among Asian groups, Korean men had higher femoral neck BMD and lower total hip BMD. CONCLUSION These findings show substantial race/ethnic differences in BMD even within African or Asian origin and illustrate the important role of body size on the difference between Asian men and others.
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Yuen KWK, Kwok TCY, Qin L, Leung JCS, Chan DCC, Kwok AWL, Woo J, Leung PC. Characteristics of age-related changes in bone compared between male and female reference Chinese populations in Hong Kong: a pQCT study. J Bone Miner Metab 2010; 28:672-81. [PMID: 20393762 DOI: 10.1007/s00774-010-0170-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Accepted: 02/08/2010] [Indexed: 10/19/2022]
Abstract
There have been few comprehensive studies on the age-related changes in bone mineral density (BMD) and bone structure in Chinese people. Using peripheral quantitative computed tomography (pQCT), we assessed volumetric BMD of both trabecular and cortical bone and their geometry at both radius and tibia in 620 Chinese men and 638 women, aged 20–98 years, in Hong Kong. Cortical BMD did not start declining until after the age of 50 years in women and the age of 60 years in men. In contrast, trabecular BMD declined with age starting from adulthood in both sexes, and the rates of decline accelerated after the age of 50 years only in women. The integral and trabecular bone area expanded with age in older men and women, primarily at the tibia. Cortical bone area decreased significantly in older women, particularly at the tibia, while it decreased only slightly with aging in men. The moment of inertia decreased with age at the radius in older men and women. At the tibia, age-related decline accelerated in older women, but not in older men. It was concluded that trabecularization of bone in response to declining BMD and mechanical loading may be maladaptive by reducing cortical bone area, if periosteal apposition cannot keep pace with it.
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Lam FFY, Deng SY, Ng ESK, Yeung JHK, Kwan YW, Lau CBS, Koon JCM, Zhou L, Zuo Z, Leung PC, Fung KP. Mechanisms of the relaxant effect of a danshen and gegen formulation on rat isolated cerebral basilar artery. JOURNAL OF ETHNOPHARMACOLOGY 2010; 132:186-192. [PMID: 20723594 DOI: 10.1016/j.jep.2010.08.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 06/25/2010] [Accepted: 08/09/2010] [Indexed: 05/29/2023]
Abstract
AIM OF THE STUDY Danshen (root of Salvia miltiorrhiza) and gegen (root of Pueraria lobata) are two herbs used in traditional Chinese medicine, most commonly for their putative cardioprotective and anti-atherosclerotic effects. In this study, the actions of a danshen and gegen formulation (DG; ratio 7:3) were investigated on rat-isolated cerebral basilar artery. MATERIALS AND METHODS Rat basilar artery rings were precontracted with 100 nM U46619. Involvement of endothelium-dependent mechanisms was investigated by mechanical removal of the endothelium; K(+) channels were investigated by pretreatment of the artery rings with various K(+) channel inhibitors, and Ca(2+) channels were investigated in artery rings incubated with Ca(2+)-free buffer and primed with 100 nM U46619 for 5 min prior to adding CaCl(2) to elicit contraction. RESULTS DG produced concentration-dependent relaxation of the artery rings with an IC(50) of 895±121 μg/ml. Mechanical removal of the endothelium or pretreatment with the BK(Ca) channel inhibitor iberiotoxin (100 nM), the K(V) channel inhibitor 4-aminopyridine (1 mM), or the K(IR) channel inhibitor barium chloride (100 μM), all had no effect on the DG-induced response (P>0.05 for all). However, pretreatment with the K(ATP) channel inhibitor glibenclamide (1 μM), the non-selective K(+) channel inhibitor tetraethylammonium (TEA, 100 mM), or a combination of all the K(+) channel inhibitors (iberiotoxin+4-aminopyrindine+barium chloride+glibenclamide+TEA) produced significant inhibition on the DG-induced response (P<0.01 for all); its maximum vasorelaxant effect (Imax) was reduced by 37, 24, and 30%, respectively. Preincubation of the artery rings with DG for 10 min produced concentration-dependent (1, 3 and 7 mg/ml) and total inhibition on the CaCl(2)-induced vasoconstriction. CONCLUSIONS These findings suggest the vasorelaxant effect of DG on rat basilar artery is independent of endothelium-derived mediators, whereas, inhibition of Ca(2+) influx in the vascular smooth muscle cells is important, and a minor component is mediated by the opening of K(ATP) channels. DG could be a useful cerebroprotective agent in some patients with occlusive cerebrovascular disease.
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Orwoll ES, Nielson CM, Labrie F, Barrett-Connor E, Cauley JA, Cummings SR, Ensrud K, Karlsson M, Lau E, Leung PC, Lunggren O, Mellström D, Patrick AL, Stefanick ML, Nakamura K, Yoshimura N, Zmuda J, Vandenput L, Ohlsson C. Evidence for geographical and racial variation in serum sex steroid levels in older men. J Clin Endocrinol Metab 2010; 95:E151-60. [PMID: 20668046 PMCID: PMC3050097 DOI: 10.1210/jc.2009-2435] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Despite considerable racial and geographical differences in human phenotypes and in the incidence of diseases that may be associated with sex steroid action, there are few data concerning variation in sex steroid levels among populations. We designed an international study to determine the degree to which geography and race influence sex steroid levels in older men. METHODS Using mass spectrometry, concentrations of serum androgens, estrogens, and sex steroid precursors/metabolites were measured in 5003 older men from five countries. SHBG levels were assessed using radioimmunoassay. RESULTS There was substantial geographical variation in the levels of sex steroids, precursors, and metabolites, as well as SHBG. For instance, Asian men in Hong Kong and Japan, but not in the United States, had levels of total testosterone approximately 20% higher than in other groups. Even greater variation was present in levels of estradiol, SHBG, and dihydrotestosterone. Group differences in body mass index did not explain most geographical differences. In addition, body mass index-independent racial differences were present; Black men had higher levels of estrogens (estradiol, estrone), and Asian men had lower levels of glucuronidated androgen metabolites. CONCLUSIONS On a global scale, there are important geographical and racial differences in the concentrations of serum sex steroids and SHBG in older men.
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Wong SYS, Woo J, Leung PC. Genitourinary problems and mood disorders in elderly Chinese men in Hong Kong: an epidemiological cohort study. Hong Kong Med J 2010; 16 Suppl 3:17-19. [PMID: 20601728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023] Open
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Kwok T, Ohlsson C, Vandenput L, Tang N, Zhang YF, Tomlinson B, Leung PC. ACE inhibitor use was associated with lower serum dehydroepiandrosterone concentrations in older men. Clin Chim Acta 2010; 411:1122-5. [PMID: 20403346 DOI: 10.1016/j.cca.2010.04.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Revised: 04/12/2010] [Accepted: 04/13/2010] [Indexed: 11/28/2022]
Abstract
CONTEXT Angiotensin converting enzyme (ACE) activity may influence the production of adrenal androgen precursors and testosterone. Use of ACE inhibitors may therefore have an influence on serum sex hormone concentrations in older men. DESIGN AND METHODS 1486 out of 2,000 community-dwelling Chinese men aged 65years who participated in a cohort study were randomly selected to have archived fasting morning serum analyzed for androgen precursors and sex hormones. DNA was extracted from whole blood and analyzed for ACE gene I/D polymorphism. RESULTS Subjects with the ACE gene D allele (higher ACE activity) had higher serum dehydroepiandrosterone (DHEA) sulphate and DHEA than those with I/I genotype (P=0.014 and 0.018 respectively, Mann Whitney test). These differences were not significant after Bonferroni correction. Among those with history of hypertension, but without diabetes mellitus or cardiac failure, users of ACE inhibitors had significantly lower serum DHEA (median 1.78 versus 1.49ng/ml in non-users, P=0.0074, Mann Whitney test) and also tended to have lower serum androstenedione and androst-5-ene-3beta,17beta-diol (0.68 versus 0.72ng/ml in non-users; 552.4 versus 624.1pg/ml respectively, both P values <0.05). Serum testosterone and estradiol were not significantly changed. CONCLUSIONS ACE inhibitor use was associated with lower serum DHEA in older men.
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Tang NLS, Woo J, Suen EWC, Liao CD, Leung JCS, Leung PC. The effect of telomere length, a marker of biological aging, on bone mineral density in elderly population. Osteoporos Int 2010; 21:89-97. [PMID: 19436937 DOI: 10.1007/s00198-009-0948-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Accepted: 03/27/2009] [Indexed: 01/20/2023]
Abstract
UNLABELLED Telomere length (TL), as a reflection of aging and inflammatory processes, may be associated with bone mineral density (BMD). This study examines the association between TL and BMD cross-sectionally and the rate of bone loss over a 4-year period in 1,867 Chinese elderly community living subjects. After adjusting for confounding factors, no association was observed with BMD or bone loss. The decline in BMD with aging is not reflected by corresponding changes in telomere length. INTRODUCTION Bone mineral density (BMD) is influenced by the dynamics of aging, inflammatory, and bone remodeling processes. Telomere length (TL) is a reflection of the former two processes and may also be associated with bone loss. METHODS Hip BMD was measured in 1,867 Chinese elderly community living subjects and the relationship between leukocyte TL measured using quantitative real-time polymerase chain reaction, and bone loss after 4 years was examined. RESULTS Women had greater bone loss than men. In women, age of menopause, menarche, estrogen treatment/replacement therapy, and history of previous fracture were also among the significant covariates. However, in multivariate analyses, TL was not associated with BMD in either sex. CONCLUSIONS TL was not associated with either baseline BMD or bone loss over 4 years and accounted for less than 1.6% of the baseline BMD.
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Auyeung TW, Lee JSW, Kwok T, Leung J, Leung PC, Woo J. Estimation of stature by measuring fibula and ulna bone length in 2443 older adults. J Nutr Health Aging 2009; 13:931-6. [PMID: 19924356 DOI: 10.1007/s12603-009-0254-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Accepted: 12/10/2008] [Indexed: 10/19/2022]
Abstract
UNLABELLED Estimation of Stature by Measuring Fibula and Ulna Bone Length in 2443 Older Adults. OBJECTIVES Knee height has been commonly used to estimate stature but may not always be possible in the frail older adults with compromised posture. Measurement of fibula and ulna bone length could be an alternative method. We attempted to develop and validate regression models to predict measured and reported height using age, fibula length, ulna length, hip circumferences and body weight. DESIGN A cross-sectional survey. SETTING The study was conducted in the Jockey Club Centre for Osteoporosis Care and Control, School of Public Health, The Chinese University of Hong Kong. PARTICIPANTS Two thousand four hundred and forty three community-dwelling older Chinese aged from 65 to 98 years were recruited. MEASUREMENTS The standing height, fibula length, ulna length, hip circumference and body weight were measured and the reported height was recorded. Three separate multiple linear regression models were developed to predict measured-height and reported-height respectively. RESULTS In predicting measured-height by the bone-length model, the mean errors were +0.52 cm (over-estimation) in men and +0.45 cm (over-estimation) in women and the SDs were +/- 3.5 cm in both genders. The 95% limits of agreement were: -6.65 to +7.70 cm for men and -6.59 to +7.49 cm for women. CONCLUSION The accuracy and precision of stature estimation by fibula and ulna bone length is comparable to that by knee height. This may be an acceptable alternative method when knee height measurement is difficult or when the knee height caliper is not available.
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Haines CJ, Lam PM, Chung TKH, Cheng KF, Leung PC. A randomized, double-blind, placebo-controlled study of the effect of a Chinese herbal medicine preparation (Dang Gui Buxue Tang) on menopausal symptoms in Hong Kong Chinese women. Climacteric 2009; 11:244-51. [DOI: 10.1080/13697130802073029] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Lau TW, Chan YW, Lau CP, Lau KM, Lau CBS, Fung KP, Leung PC, Ho YY. Radix Astragali and Radix Rehmanniae, the principal components of two antidiabetic foot ulcer herbal formulae, elicit viability-promoting effects on primary fibroblasts cultured from diabetic foot ulcer tissues. Phytother Res 2009; 23:809-15. [DOI: 10.1002/ptr.2649] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Lau TW, Lam FFY, Lau KM, Chan YW, Lee KM, Sahota DS, Ho YY, Fung KP, Leung PC, Lau CBS. Pharmacological investigation on the wound healing effects of Radix Rehmanniae in an animal model of diabetic foot ulcer. JOURNAL OF ETHNOPHARMACOLOGY 2009; 123:155-162. [PMID: 19429355 DOI: 10.1016/j.jep.2009.02.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Revised: 01/04/2009] [Accepted: 02/02/2009] [Indexed: 05/27/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Radix Rehmanniae (RR) has a very long history of usage in traditional Chinese medicine and is usually one of the principal herb found in many herbal formulae used in diabetic foot ulcer. AIM OF THE STUDY RR aqueous extract was investigated for its wound healing effects in a diabetic foot ulcer rat model and its detailed mechanism of actions. MATERIALS AND METHODS A previously established diabetic foot ulcer rat model was used to assess the effect of RR extract on wound area reduction, tissue regeneration and angiogenesis. Carrageenan-induced inflammation rat model was used for inflammation study; and diabetic control was evaluated using a neonatal streptozotocin-induced diabetic rat model. RESULTS In the RR treated group, a trend of reduction of the wound area was observed from days 8 to 18 and a significant difference (as compared with control group) was found on day 8. The ulcer healing effect of RR extract was further supported by better developed scars and epithelialization as well as good formation of capillaries with enhanced VEGF expression. Carrageenan-induced inflammation was also significantly alleviated with RR extract. CONCLUSIONS Our results demonstrated for the first time that Radix Rehmanniae was effective in promoting diabetic foot ulcer healing in rats through the processes of tissue regeneration, angiogenesis and inflammation control, but not glycemia control. The present study provided scientific basis to support the traditional use of Radix Rehmanniae in diabetic foot ulcer.
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