Elderly males with or without existing osteoporotic vertebral fracture have much lower future vertebral fracture risk than elderly females: the MrOS (Hong Kong) year-4 follow-up spine radiograph study

MrOS (Hong Kong)'s year-4 follow-up shows, for subjects at baseline without vertebral deformity (VD) and endplate or/and cortex fracture (ECF), the VD progression/new VD rate during follow-up in males was half of our paired MsOS (Hong Kong) study's results. For those with VD or ECF, the VD progression/new VD was less than one sixth of females' rate.

INTRODUCTION

This study documents MrOS (Hong Kong)'s year-4 follow-up, and the results are compared with the MsOS (Hong Kong) study. Of elderly females with Genant's grade-0, -1, -2, and -3 VD, at year-4 follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or incident VD, respectively.

METHODS

Spine radiographs of 1500 Chinese males with baseline (mean age 71.7 years, range 65-91 years) and year-4 follow-up were evaluated according to Genant's VD criteria and ECF (non-existent, ECF0; or existent, ECF1). Grade-2 VDs were divided into mild (VD2m, 25-34% height loss) and severe (VD2s, 34-40% height loss) subgroups. Study subjects were graded into eight categories: VD0/ECF0, VD1/ECF0, VD2m/ECF0, VD0/ECF1, VD1/ECF1, VD2m/ECF1, VD2s/ECF1, and VD3/ECF1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new VD incident was a change from grade-0 to grade-2/3, or to grade-1 with ≥ 10% height loss.

RESULTS

Of subjects with Genant's grade-0, 2.05% (25/1219) developed at least one VD progression or/and new VD, while of subjects with Genant's grade-1, -2, and -3 VD, only 2% (3/149), 3.1% (3/96), and 2.8% (1/36) developed at least one VD progression/new VD, respectively. Among the three ECF0 groups, there was a significant difference in new ECF incidence, with VD0/ECF0 being the lowest and VD2m/ECF0 being the highest.

CONCLUSION

VD progression/new VD is much less common in elderly men than in elderly women. Vertebrae with VD had a higher risk of developing ECF.

Osteoporotic vertebral deformity with endplate/cortex fracture is associated with higher further vertebral fracture risk: the Ms. OS (Hong Kong) study results

Compared with vertebrae without deformity, vertebrae with mild/moderate deformity have a higher risk of endplate or/and cortex fracture (ecf). Compared with subjects without ecf, subjects with ecf are at a higher risk of short-term (4-year period) deformity progression and new incident deformity.

INTRODUCTION

The progression and incidence of osteoporotic vertebral deformity/fracture (VD/VF) in elderly Chinese females remain not well documented.

METHODS

Spine radiographs of 1533 Chinese females with baseline and year-4 follow-up (mean age 75.7 years) were evaluated according to Genant's VD criteria and endplate/cortex fracture (non-existent: ecf0 or existent: ecf1). Grade-2 VDs were divided into mild (vd2m, 25-34% height loss) and severe (vd2s, 34-40% height loss) subgroups. According to their VD/VF, subjects were graded into seven categories: vd0/ecf0, vd1/ecf0, vd2m/ecf0, vd1/ecf1, vd2m/ecf1, vd2s/ecf1, and vd3/ecf1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new incident VD was a change from grade-0 to grade-2/3 or to grade-1 with ≥ 10% height loss.

RESULTS

Of subjects with Genant's grades 0, - 1, - 2, and - 3 VD, at follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or new incident VD respectively. Among the three ecf0 groups, there was no difference in VD progression or new VD; while there was a significant difference in new ecf incidence, with vd0/ecf0 being lowest and vd2m/ecf0 being highest. Vd1/ecf0 and vd2m/ecf0 vertebrae had a higher risk of turning to ecf1 than vd0/ecf0 vertebrae. If vd1/ecf0 and vd2m/ecf0 subjects were combined together (range 20-34% height loss) to compare with vd1/ecf1 and vd2m/ecf1 subjects, the latter had significantly higher VD progression and new VD rates.

CONCLUSION

Vertebrae with grade-1/2 VDs had a higher risk of developing ECF. Subjects with pre-existing ECFs had a higher risk of worsening or new vertebral deformities.

Isodon eriocalyx and its bioactive component Eriocalyxin B enhance cytotoxic and apoptotic effects of gemcitabine in pancreatic cancer

BACKGROUND

Pancreatic cancer, associated with poor prognosis and low survival rate, has been the fourth leading cause of cancer-related death in the US. Although gemcitabine (Gem) is the first-line chemotherapeutic drug in the management of pancreatic cancer, the median survival extension is only 1.5 months, indicating unsatisfactory clinical results. Therefore, exploring agents that can enhance the anti-cancer activity of Gem would be an attractive strategy.

PURPOSE

Our previous studies have demonstrated that eriocalyxin b (EriB), an ent‑kaurane diterpenoid isolated from Isodon eriocalyx (Dunn.) Hara, possesses anti-pancreatic cancer effects, thus acting as a potential therapeutic agent. In this study, we further investigated whether EriB or the ethanol extract of I. eriocalyx (Isodon) could potentiate the cytotoxic activity of Gem in human pancreatic adenocarcinoma cells. In addition, the mechanism associated with their effects was also studied.

METHODS

The anti-proliferation effect was assessed by MTT assay and Ki-67 immunostaining. The combination effect (addition, synergism and antagonism) of various agents was calculated by the Calcusyn software (Biosoft), utilizing the T.C. Chou Method. Apoptosis was detected using Annexin V and PI double staining followed by quantitative flow cytometry. Protein expression regulated by various treatments was analyzed by western blotting.

RESULTS

The combination index revealed that Gem and EriB (or Isodon extract) had synergistic anti-proliferative effect. Both cellular apoptotic and anti-proliferative effects of Gem were significantly increased after combination with EriB (or Isodon extract). The underlying mechanisms involved in the combination effects were elucidated, which include: (1) increased activation of the caspase cascade; (2) reduction of PDK1 and AKT phosphorylation; (3) induction of JNK phosphorylation by Isodon and Gem combination.

CONCLUSION

Gem and EriB (or Isodon extract) taken together in combination regulated PDK1/AKT1/caspase and JNK signaling and promoted apoptosis synergistically, which may contribute to the much increased anti-proliferative activity compared to either agent alone.

No Effects of Black Tea on Cognitive Decline Among Older US Men: A Prospective Cohort Study

BACKGROUND

Accumulating evidence supports the neuroprotective effects of bioactive compounds from tea leaves. There are limited data from black tea consumption populations.

OBJECTIVE

To determine whether black tea consumption is associated with cognitive decline among older men.

METHODS

We chose to study the association between black tea consumption and cognition using data from the Osteoporotic Fractures in Men (MrOS) cohort, which collected information on tea consumption at baseline and has repeatedly assessed cognitive function in 3,844 men aged 65+ years (mean = 72.4 years). We defined tea drinkers as those who drank black tea at least once per week and further grouped them into weekly drinkers and daily drinkers. Cognitive function was assessed at baseline and approximately 7 years later using the Modified Mini-Mental State Examination (3MSE). Multivariable logistic regression and linear regression models were constructed to assess the association between black tea consumption and risk of fast cognitive decline as a binary variable and change in 3MSE scores as continuous variable. Fast cognitive decline was defined as decline in 3MSE >1.5 standard deviation of mean change score. Models were adjusted for age, education level, and baseline cognitive scores.

RESULTS

Weekly and daily black tea drinkers were 24.8% and 12.4% of the study cohort, respectively. Fast cognitive decline occurred in 243 (6.3%) participants. Tea consumption was not associated with risk of cognitive decline, nor was tea associated with cognitive decline measured by absolute change in 3MSE scores.

CONCLUSIONS

There was no association of black tea consumption and cognitive decline among older men in the US.

Effects of 18-month low-magnitude high-frequency vibration on fall rate and fracture risks in 710 community elderly--a cluster-randomized controlled trial

This study is a prospective cluster-randomized controlled clinical trial involving 710 elderly subjects to investigate the long-term effects of low-magnitude high-frequency vibration (LMHFV) on fall and fracture rates, muscle performance, and bone quality. The results confirmed that LMHFV is effective in reducing fall incidence and enhancing muscle performance in the elderly.

INTRODUCTION

Falls are direct causes of fragility fracture in the elderly. LMHFV has been shown to improve muscle function and bone quality. This study is to investigate the efficacy of LMHFV in preventing fall and fractures among the elderly in the community.

METHODS

A cluster-randomized controlled trial was conducted with 710 postmenopausal females over 60 years. A total of 364 participants received daily 20 min LMHFV (35 Hz, 0.3 g), 5 days/week for 18 months; 346 participants served as control. Fall or fracture rate was taken as the primary outcome. Also, quadriceps muscle strength, balancing abilities, bone mineral density (BMD), and quality of life (QoL) assessments were done at 0, 9, and 18 months.

RESULTS

With an average of 66.0% compliance in the vibration group, 18.6% of 334 vibration group subjects reported fall or fracture incidences compared with 28.7% of 327 in the control (adjusted HR = 0.56, p = 0.001). The fracture rate of vibration and control groups were 1.1 and 2.3 % respectively (p = 0.171). Significant improvements were found in reaction time, movement velocity, and maximum excursion of balancing ability assessment, and also the quadriceps muscle strength (p < 0.001). No significant differences were found in the overall change of BMD. Minimal adverse effects were documented.

CONCLUSION

LMHFV is effective in fall prevention with improved muscle strength and balancing ability in the elderly. We recommend its use in the community as an effective fall prevention program and to decrease related injuries.

Cerebral vasodilator properties of Danshen and Gegen: a study of their combined efficacy and mechanisms of actions

Danshen and Gegen are two commonly used Chinese herbal medicines for treatment of cardiovascular diseases. The aim of the present study was to elucidate the combination effects of these two herbs on cerebral vascular tone and their underlying mechanisms of actions. Basilar artery rings were obtained from rats and precontracted with U46619. Cumulative administrations of aqueous extracts of Danshen, Gegen, or the two herbs combined (DG; ratio 7:3) produced concentration-dependent relaxation of the artery rings. Statistical analysis on these findings produced a combination index (CI) of 1.041 at ED50, which indicates the two herbs produced additive vasodilator effects when used as a combined decoction. Removal of the endothelium had no effect on the vasodilator properties of Danshen, Gegen, and DG. However, their maximum effects (Imax) were significantly blunted by a KATP channel inhibitor glibenclamide, a non-selective K(+) channel inhibitor tetraethylammonium (TEA), and by a combination of K(+) channel inhibitors (glibenclamide+TEA+iberiotoxin+4-aminopyridine+barium chloride). In addition, Danshen, Gegen, and DG produced augmentation of KATP currents and inhibited Ca(2+) influx in vascular smooth muscle cells isolated from rat basilar arteries. Furthermore, these agents inhibited CaCl2-induced contraction in the artery rings. In conclusion, the present study showed that Danshen and Gegen produced additive vasodilator effects on rat cerebral basilar arteries. These effects were independent of endothelium-derived relaxant factors (EDRF), but required the opening of KATP channels and inhibition of Ca(2+) influx in the vascular smooth muscle cells. It is suspected that the cerebral vasodilator effects of Danshen and Gegen produced either on their own or in combination, can help patients with obstructive cerebrovascular diseases.

The functional muscle-bone unit in subjects of varying BMD

SUMMARY

This study used the "functional muscle-bone unit" concept to investigate muscle-bone interaction of the lumbar spine in subjects of varying bone mineral density. It was found that unit bone mass corresponded to a relatively more muscle mass in subjects with reduced bone mineral density, indicating a relatively higher mechanical load from muscles exerted on trabecular bone.

INTRODUCTION

Bone is an architecturally adaptive tissue which responds to mechanical loading. This study is proposed to use "functional muscle-bone unit" to reflect this muscle-bone interaction at spine in subjects with different bone mineral density.

METHODS

The study was carried out in young normal subjects (21 females; age, 29 ± 3) and elderly subjects (155 females; age, 73 ± 3.9) with varying bone mineral density. Cross-sectional area of paravertebral muscle groups was measured in MR images to indicate the muscle mass, while the bone mineral content by dual X-ray absorptiometry was used to represent the bone mass. The functional muscle-bone unit was calculated as the ratio between the bone mass to muscle mass.

RESULTS

It showed that with aging, the muscle mass decreased with the bone mass losing. However, more pronounced reduction was found in bone mass than in muscle mass in the subjects with lower bone mineral density.

CONCLUSIONS

Muscle-bone interaction was changed in elderly, especially in those with osteoporosis. Unit bone mass corresponded to a higher muscle mass in subjects with reduced bone mineral density than those normal subjects. This may be contributory to the occurrence of nontraumatic vertebral fractures in elderly subjects with reduced bone mineral density.

Eriocalyxin B-induced apoptosis in pancreatic adenocarcinoma cells through thiol-containing antioxidant systems and downstream signalling pathways

Thiol-containing antioxidant systems play an important role in regulating cellular redox homeostasis. Several anti-cancer agents act by targeting these systems by inducing the production of reactive oxygen species (ROS). Our earlier studies have shown that Eriocalyxin B (EriB), a diterpenoid isolated from Isodon eriocalyx, possesses anti-pancreatic tumour activities in vitro and in vivo. The present study further demonstrated that only thiol-containing antioxidants, N-acetylcysteine (NAC) or dithiothreitol (DTT), inhibited EriB-induced cytotoxicity and apoptosis. EriB suppressed the glutathione and thioredoxin antioxidant systems, thus increasing the intracellular ROS levels and regulating the MAPK, NFκB pathways. Treatment with EriB depleted the intracellular thiol-containing proteins in CAPAN-2 cells. In vivo studies also showed that EriB treatment (2.5 mg/kg) reduced the pancreatic tumour weights significantly in nude mice with increased superoxide levels. Taken together, our results shed important new light on the molecular mechanisms of EriB acting as an apoptogenic agent and its therapeutic potential for pancreatic cancer.

International and ethnic variability of falls in older men

Aims: Fallers and especially recurrent fallers are at high risk for injuries. The aim of this study was to evaluate fall epidemiology in older men with special attention to the influence of age, ethnicity and country of residence. Methods: 10,998 men aged 65 years or above recruited in Hong Kong, the United States (US) and Sweden were evaluated in a cross-sectional retrospective study design. Self-reported falls and fractures for the preceding 12 months were registered through questionnaires. Group comparisons were done by chi-square test or logistic regression. Results: The proportion of fallers among the total population was 16.5% in ages 65–69, 24.8% in ages 80–84 and 43.2% in ages above 90 ( P <0.001). The corresponding proportions of recurrent fallers in the same age groups were 6.3%, 10.1% and 18.2%, respectively ( P <0.001), and fallers with fractures 1.0%, 2.3% and 9.1%, respectively ( P <0.001). The proportion of fallers was highest in the US, intermediate in Sweden and lowest in Hong Kong (in most age groups P <0.05). The proportion of fallers among white men in the US was higher than in white men in Sweden (all comparable age groups P <0.01) but there were no differences in the proportion of fallers in US men with different ethnicity. Conclusions: The proportion of fallers in older men is different in different countries, and data in this study corroborate with the view that society of residence influences fall prevalence more than ethnicity.

SLE disease per se contributes to deterioration in bone mineral density, microstructure and bone strength

OBJECTIVE

The objective of this report is to assess the effect of systemic lupus erythematosus (SLE) disease itself on deterioration of bone mineral density (BMD), microstructure and bone strength.

METHOD

Thirty age-matched SLE patients on long-term glucocorticoids (GC) (SLE/GC), 30 SLE patients without GC (SLE/non-GC) and 60 healthy controls were examined. Areal BMD (aBMD) was measured by dual-energy X-ray absorptiometry. Bone geometry, volumetric BMD (vBMD), and architectural parameters at the nondominant distal radius were assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT). Bone strength was estimated by HR-pQCT-based micro-finite element analysis.

RESULTS

Adjusted for menopausal status and adjusted calcium level, when compared with controls, SLE/non-GC patients had significantly lower aBMD at femoral neck and total hip, and diminished radial total vBMD, cortical area, vBMD and thickness, respectively, by 8.3%, 8%, 2.7% and 9.2%, as well as significant compromised bone strength (stiffness, failure load and apparent modulus) by 8.3%, 9.1% and 9.5%, respectively. Similar alterations were also found in SLE/GC patients when compared to controls. In the premenopausal subgroup analysis, when compared with controls, total hip aBMD and radial cortical area were significantly lower in SLE/non-GC patients, and cortical area and thickness were significantly deficit in SLE/GC patients. However, no significant difference in any bone variables was present between SLE/GC and SLE/non-GC patients in the entire cohort or in the premenopausal subgroup.

CONCLUSION

SLE disease per se contributes to the deterioration in bone density, cortical microstructure and bone strength. This might help to explain the considerably higher fracture risk seen in SLE patients.

Alterations of bone geometry, density, microarchitecture, and biomechanical properties in systemic lupus erythematosus on long-term glucocorticoid: a case-control study using HR-pQCT

Compared to controls, HR-pQCT at distal radius of SLE patients on chronic glucocorticoid (SLE/GC) revealed reduced bone area, vBMD, deteriorated microarchitecture, and unevenly distributed stresses limited to cortical bone. Despite similar trabecular quality, whole bone strength decreased in patients. These alterations may partly explain high fracture rates in SLE/GC.

INTRODUCTION

To assess bone geometric, densitometric, microarchitectural, and biomechanical properties in patients with systemic lupus erythematosus (SLE) on long-term glucocorticoid (GC) (SLE/GC) as compared with healthy controls.

METHODS

A total of 180 female SLE patients and 180 healthy controls were in this cross-sectional study to assess areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry. High-resolution peripheral quantitative computed tomography (HR-pQCT) and microfinite element analysis (μFEA) was performed at distal radius.

RESULTS

In addition to significantly lower aBMD at femoral neck, total hip and lumbar spine, cortical area, average volumetric BMD (vBMD) and cortical vBMD also significantly reduced by 5.3, 5.7, to 1.9 % in SLE patients, respectively. Deteriorations of cortical microarchitecture were pronounced in patients, with 6.3 % reduction in cortical thickness and 13.6 % higher in cortical porosity. Local stresses were more unevenly distributed through cortical bone in patients. SLE/GC patients had decreased whole bone stiffness, estimated failure load, and apparent modulus. Parameters related to trabecular bone density and microarchitecture were comparable between patients and controls.

CONCLUSION

In SLE/GC patients, despite a reduction in bone area, vBMD and deteriorated microarchitecture and unevenly distributed stresses limited to the cortical compartment, whole bone strength decreased. HR-pQCT and μFEA were promising in elucidating the potential underlying pathophysiology of bone loss and propensity to fracture in SLE/GC and provide us additional information about alterations of bone quality which might better predict fracture risk beyond aBMD in SLE/GC.

Genome-wide association study in a Chinese population identifies a susceptibility locus for type 2 diabetes at 7q32 near PAX4

AIMS/HYPOTHESIS

Most genetic variants identified for type 2 diabetes have been discovered in European populations. We performed genome-wide association studies (GWAS) in a Chinese population with the aim of identifying novel variants for type 2 diabetes in Asians.

METHODS

We performed a meta-analysis of three GWAS comprising 684 patients with type 2 diabetes and 955 controls of Southern Han Chinese descent. We followed up the top signals in two independent Southern Han Chinese cohorts (totalling 10,383 cases and 6,974 controls), and performed in silico replication in multiple populations.

RESULTS

We identified CDKN2A/B and four novel type 2 diabetes association signals with p < 1 × 10(-5) from the meta-analysis. Thirteen variants within these four loci were followed up in two independent Chinese cohorts, and rs10229583 at 7q32 was found to be associated with type 2 diabetes in a combined analysis of 11,067 cases and 7,929 controls (p meta = 2.6 × 10(-8); OR [95% CI] 1.18 [1.11, 1.25]). In silico replication revealed consistent associations across multiethnic groups, including five East Asian populations (p meta = 2.3 × 10(-10)) and a population of European descent (p = 8.6 × 10(-3)). The rs10229583 risk variant was associated with elevated fasting plasma glucose, impaired beta cell function in controls, and an earlier age at diagnosis for the cases. The novel variant lies within an islet-selective cluster of open regulatory elements. There was significant heterogeneity of effect between Han Chinese and individuals of European descent, Malaysians and Indians.

CONCLUSIONS/INTERPRETATION

Our study identifies rs10229583 near PAX4 as a novel locus for type 2 diabetes in Chinese and other populations and provides new insights into the pathogenesis of type 2 diabetes.

Synergistic effects of diosmetin with erythromycin against ABC transporter over-expressed methicillin-resistant Staphylococcus aureus (MRSA) RN4220/pUL5054 and inhibition of MRSA pyruvate kinase

Increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) worldwide with limited therapeutic options is a growing public health concern. Natural products have been shown to possess antibacterial actions against MRSA. Flavonoids from natural products have been shown to possess antibacterial actions against MRSA by antagonizing its resistance mechanisms. Diosmin and diosmetin are natural flavonoids found in a variety of citrus fruits. The aim of this study was to investigate whether diosmin and diosmetin could inhibit the growth of MRSA and the in vitro enzymatic activity of a newly discovered MRSA drug target, pyruvate kinase (PK). By using a panel of MRSA strains with known resistant mechanisms, neither diosmin nor diosmetin was shown to possess direct antibacterial activities against all tested MRSA strains. However, in checkerboard assay, we found that diosmetin together with erythromycin, could synergistically inhibit the growth of ABC-pump overexpressed MRSA-RN4220/pUL5054, and time kill assay also showed that the antibacterial activities of diosmetin with erythromycin were bactericidal. Diosmetin was further shown to significantly suppress the MRSA PK activities in a dose dependent manner. In conclusion, the inhibition of MRSA PK by diosmetin could lead to a deficiency of ATP and affect the bacterial efflux pump which might contribute to the antibacterial actions of diosmetin against MRSA.

Racial/ethnic differences in bone mineral density among older women

The epidemiologic information regarding international differences in bone mineral density (BMD) in women is currently insufficient. We compared BMD in older women across five racial/ethnic groups in four countries. The femoral neck, total hip, and lumbar spine BMD were measured in women (aged 65-74 years) from the Study of Osteoporotic Fractures (SOF) (5,035 Caucasian women and 256 African American women in the US), the Tobago Women's Health Study (116 Afro-Caribbean women), the Ms Os Hong Kong Study (794 Hong Kong Chinese women) and the Namwon Study (1,377 South Korean women). BMD was corrected according to the cross-site calibration results for all scanners. When compared with US Caucasian women, the age adjusted mean BMD measurements at the hip sites were 21-31 % higher among Tobago Afro-Caribbean women and 13-23 % higher among African American women. The total hip and spine BMD values were 4-5 % lower among Hong Kong Chinese women and 4-7 % lower among South Korean women compared to US Caucasians. The femoral neck BMD was similar in Hong Kong Chinese women, but higher among South Korean women compared to US Caucasians. Current/past estrogen use was a significant contributing factor to the difference in BMD between US versus non-US women. Differences in body weight partially explained the difference in BMD between Asian versus non-Asian women. These findings show substantial racial/ethnic differences in BMD even within African or Asian origin individuals, and highlight the contributing role of body weight and estrogen use to the geographic and racial/ethnic variation in BMD.

Prevalence and risk factors of radiographic vertebral fractures in elderly Chinese men and women: results of Mr. OS (Hong Kong) and Ms. OS (Hong Kong) studies

This study investigated the prevalence of radiographic vertebral fractures using Genant's semiquantitative (SQ) scoring system in elderly Chinese men (n = 2,000; mean age, 72.4 years) and women (n = 2,000; mean age, 72.6 years). Vertebral deformities had similar prevalence in elderly men (14.9 %) and women (16.5 %). Majority of the deformities in men were mild (9.9 %, grade = 1). The prevalence of vertebral fractures (grade ≥ 2) was 5.0 % among men and 12.1 % among women.

INTRODUCTION

Vertebral fracture is a serious consequence of osteoporosis and is often under-diagnosed. Researches on different ethnicities and territories to estimate the prevalence of vertebral fractures and to identify the risk factors are necessary.

METHODS

Mr. OS (Hong Kong) and Ms. OS (Hong Kong) represent the first large-scale cohort studies ever conducted on bone health in elderly Chinese men (n = 2,000) and women (n = 2,000). The current study investigated the prevalence of radiographic vertebral fractures in these subjects using Genant's SQ scoring system and identified risk factors for vertebral fractures.

RESULTS

The radiographs of all men (mean age, 72.4 years) and women (mean age, 72.6 years) were obtained. Six hundred twenty-seven subjects (15.7 %) had at least one vertebral deformity (SQ grade ≥ 1), including 297 men (14.9 %) and 330 women (16.5 %, p = 0.151). Three hundred forty-two participants (8.6 %) were defined as having at least one vertebra fracture (SQ grade ≥ 2), consisted of 100 men (5.0 %) and 242 women (12.1 %, p < 0.001). Older age, lower bone mineral density, lower physical activity, lower grip strength, fracture history, and low back pain were significantly associated with higher vertebral fracture rate for both men and women.

CONCLUSION

Vertebral deformity had similar prevalence in older men and women, while vertebral fracture was more common in women. Majority of deformities in men was mild. The vertebral deformity prevalence of women from this study is similar to previous reports of other East Asian women and Latin American women.

Inflammatory state of type II diabetic patients with chronic ulcers in response to herbal treatment

BACKGROUND

Type II diabetic patients easily develop ulcers over their feet which heal with great difficulties and not infrequently, end up in amputations. In the quest for innovative means to avoid amputation, herbal medicine has been used in China to heal ulcers.

METHOD

A randomized placebo controlled clinical trial involving 80 patients was conducted to test whether a herbal formula taken orally could help to preserve the ulcerated leg. Other parameters measured included granulation maturation time, skin temperature and circulation, and tumor necrosis factor alpha (TNF-α).

RESULTS

showed a 85% limb rescue with the herbal treatment group showing superiority over placebo group. TNF-α decline was observed with gradual ulcer healing and the herbal supplement group showed a more impressive decline (p=0.037).

Does the use of ACE inhibitors or angiotensin receptor blockers affect bone loss in older men?

In a prospective cohort study of 5,995 older American men (MrOS), users of angiotensin-converting enzyme (ACE) inhibitors had a small but significant increase in bone loss at the hip over 4 years after adjustment for confounders. Use of angiotensin II AT1 receptor blockers (ARB) was not significantly associated with bone loss.

INTRODUCTION

Experimental evidence suggests that angiotensin II promotes bone loss by its effects on osteoblasts. It is therefore plausible that ACE inhibitor and ARB may reduce rates of bone loss. The objective of this study is to examine the independent effects of ACE inhibitor and ARB on bone loss in older men.

METHODS

Out of 5,995 American men (87.2%) aged ≥65 years, 5,229 were followed up for an average of 4.6 years in a prospective six-center cohort study-The Osteoporotic Fractures in Men Study (MrOS). Bone mineral densities (BMD) at total hip, femoral neck, and trochanter were measured by Hologic densitometer (QDR 4500) at baseline and year 4.

RESULTS

Out of 3,494 eligible subjects with complete data, 1,166 and 433 subjects reported use of ACE inhibitors and ARBs, respectively. When compared with nonusers, continuous use of ACE inhibitors was associated with a small (0.004 g/cm(2)) but significant increase in the average rate of BMD loss at total hip and trochanter over 4 years after adjustment for confounders. Use of ARB was not significantly associated with bone loss.

CONCLUSION

Use of ACE inhibitors but not ARB may marginally increase bone loss in older men.

Sex steroids and bone health in older Chinese men

This study examines the association between sex steroids, bone mineral density (BMD), and incident fractures in 1,489 community-living Chinese men aged 65 and over. Chinese men with low serum estradiol levels display elevated bone loss and increased risk of fractures similar to findings in Caucasians.

INTRODUCTION

This study examines the association between serum total testosterone (TT), free testosterone (free T), estradiol (E(2)), bioavailable estradiol (bioE(2)), sex hormone binding globulin (SHBG), BMD, and incident fractures.

METHODS

This is a cohort study with 4-year follow-up in the community in Hong Kong SAR, China. One thousand four hundred eighty-nine community-living Chinese men aged 65 and over participated. Sex steroid levels and BMD were measured at baseline; BMD was repeated after 4 years of follow-up, and fracture incidence from ascertainment from hospital databases was determined over 4 years of follow-up.

RESULTS

The strongest age-adjusted positive association with total hip and femoral neck BMD was with bioE(2), followed by E(2). Greater bone loss occurred in the lowest quartile of E(2) and bioE(2). The lowest quartile of free T and bioE(2) and the two highest quartile of SHBG were associated with the highest percentage of participants with incident fractures. Those in the lowest quartile of E(2) and bioE(2) had approximately a 50% increased risk of incident fractures compared with the other three quartiles. This relationship remains significant for nonvertebral incident fractures (hip, radius, pelvis, and humerus) for E(2) only, but not bioE(2). Compared with the group with the three highest quartiles of TT and E(2), the group with the lowest quartile of both had approximately twice the risk of nonvertebral osteoporosis-related incident fractures.

CONCLUSION

Chinese men with low serum estradiol levels display elevated bone loss and increased risk of fractures similar to findings in Caucasians.

Effects of Radix Astragali and Radix Rehmanniae, the components of an anti-diabetic foot ulcer herbal formula, on metabolism of model CYP1A2, CYP2C9, CYP2D6, CYP2E1 and CYP3A4 probe substrates in pooled human liver microsomes and specific CYP isoforms

The present study investigated the effects of Radix Astragali (RA) and Radix Rehmanniae (RR), the major components of an anti-diabetic foot ulcer herbal formula (NF3), on the metabolism of model probe substrates of human CYP isoforms, CYP1A2, CYP2C9, CYP2D6, CYP2E1 and CYP3A4, which are important in the metabolism of a variety of xenobiotics. The effects of RA or RR on human CYP1A2 (phenacetin O-deethylase), CYP2C9 (tolbutamide 4-hydroxylase), CYP2D6 (dextromethorphan O-demethylase), CYP2E1 (chlorzoxazone 6-hydroxylase) and CYP3A4 (testosterone 6β-hydroxylase) activities were investigated using pooled human liver microsomes. NF3 competitively inhibited activities of CYP2C9 (IC(50)=0.98mg/ml) and CYP3A4 (IC(50)=0.76mg/ml), with K(i) of 0.67 and 1.0mg/ml, respectively. With specific human CYP2C9 and CYP3A4 isoforms, NF3 competitively inhibited activities of CYP2C9 (IC(50)=0.86mg/ml) and CYP3A4 (IC(50)=0.88mg/ml), with K(i) of 0.57 and 1.6mg/ml, respectively. Studies on RA or RR individually showed that RR was more important in the metabolic interaction with the model CYP probe substrates. RR dose-dependently inhibited the testosterone 6β-hydroxylation (K(i)=0.33mg/ml) while RA showed only minimal metabolic interaction potential with the model CYP probe substrates studied. This study showed that RR and the NF3 formula are metabolized mainly by CYP2C9 and/or CYP3A4, but weakly by CYP1A2, CYP2D6 and CYP2E1. The relatively high K(i) values of NF3 (for CYP2C9 and CYP3A4 metabolism) and RR (for CYP3A4 metabolism) would suggest a low potential for NF3 to cause herb-drug interaction involving these CYP isoforms.

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)

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.

Extracts from Radix Astragali and Radix Rehmanniae promote keratinocyte proliferation by regulating expression of growth factor receptors

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.

Mechanisms of the cerebral vasodilator actions of isoflavonoids of Gegen on rat isolated basilar artery

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.

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

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.

The anti-hypertensive effect of Danshen (Salvia miltiorrhiza) and Gegen (Pueraria lobata) formula in rats and its underlying mechanisms of vasorelaxation

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.

Potential reproductive toxicity of Largehead Atractylodes Rhizome, the most commonly used Chinese medicine for threatened miscarriage

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.

Synergistic effects of baicalein with ciprofloxacin against NorA over-expressed methicillin-resistant Staphylococcus aureus (MRSA) and inhibition of MRSA pyruvate kinase

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.

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

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.

A new ColE1-like plasmid group revealed by comparative analysis of the replication proficient fragments of Vibrionaceae plasmids

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.

The effect of diabetes mellitus on age-associated lean mass loss in 3153 older adults

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.

Race/ethnic differences in bone mineral densities in older men

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.

Characteristics of age-related changes in bone compared between male and female reference Chinese populations in Hong Kong: a pQCT study

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.

Mechanisms of the relaxant effect of a danshen and gegen formulation on rat isolated cerebral basilar artery

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.

Evidence for geographical and racial variation in serum sex steroid levels in older men

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.

ACE inhibitor use was associated with lower serum dehydroepiandrosterone concentrations in older men

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.

The effect of telomere length, a marker of biological aging, on bone mineral density in elderly population

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.

Estimation of stature by measuring fibula and ulna bone length in 2443 older adults

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.

Pharmacological investigation on the wound healing effects of Radix Rehmanniae in an animal model of diabetic foot ulcer

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.

Effect of increasing vertebral marrow fat content on BMD measurement, T-Score status and fracture risk prediction by DXA

Quantitative examination of iliac crest bone biopsies shows that as subjects become older bone and functional marrow are replaced by adipose tissue. Studies of vertebral marrow fat using nuclear magnetic resonance spectroscopy ((1)H-MRS) show that subjects with lower spine T-scores have significantly higher marrow fat content. These findings suggest that the ability of DXA scans to determine fracture risk may be partly explained by the effect of increased marrow fat on BMD. However, a proper evaluation of the relationship between WHO spine T-score status and marrow fat content requires that the BMD data are first corrected for the bias caused by a selection effect in which subjects with higher marrow fat are more likely to be identified as having osteoporosis. In this study we have therefore reanalysed previously published data for 185 elderly Hong Kong Chinese subjects (103 women, mean age 73 y; 82 men, mean age 73 y) who had spine DXA scans and (1)H-MRS measurements of L3 marrow fat. The effect of varying marrow fat on BMD was modelled using vertebral body thicknesses measured in 50 men and women. Spine T-scores in each individual were adjusted for the measured marrow fat. Subjects were assigned to WHO categories based on their corrected T-scores, and the relationship between marrow fat and T-score status evaluated using regression analysis and analysis of variance. The average change in percent marrow fat per T-score unit was used to infer the fraction of the spine BMD fracture discrimination explained by marrow composition. The mean (SD) of the L1-L4 vertebral body thickness was 30.2 (2.1) mm for Hong Kong women and 33.4 (2.5) mm for men. A change in marrow fat content from 0 to 100% was estimated to produce a BMD decrease of 0.14 g/cm(2) (1.3 T-score units) in women and 0.16 g/cm(2) (1.3 T-score units) in men. Although adjusting spine BMD for marrow fat reduced the significance of the correlation, there was still a trend for marrow fat to increase with decreasing T-score with a slope of -1.2+/-0.7% per T-score unit (p=0.078) for women and -1.4+/-0.6% per T-score unit (p=0.023) for men. When the effect of marrow composition on fracture discrimination was evaluated the results showed that the higher vertebral marrow fat content found in osteoporotic subjects made a negligible contribution to the ability of spine BMD measurements to predict fracture risk.