Bone disorders associated with diabetes mellitus and its treatments

Both type 1 and type 2 diabetes mellitus are associated with bone disorders, albeit via different mechanisms. Early studies in patients with type 1 diabetes suggested a 10-fold increase in the hip fracture risk compared to non-diabetic controls. Meta-analyses published more recently indicate a somewhat smaller risk increase, with odds ratios of 6 to 7. Diminished bone mineral density is among the contributors to the increased fracture risk. Both types of diabetes are associated with decreased bone strength related to low bone turnover. The multiple and interconnected pathophysiological mechanisms underlying the bone disorders seen in type 1 diabetes include insulin deficiency, accumulation of advanced glycation end products, bone microarchitecture alterations, changes in bone marrow fat content, low-grade inflammation, and osteocyte dysfunction. The bone alterations are less severe in type 2 diabetes. Odds ratios for hip fractures have ranged across studies from 1.2 to 1.7, and bone mineral density is higher than in non-diabetic controls. The odds ratio is about 1.2 for all bone fragility fractures combined. The pathophysiological mechanisms are complex, particularly as obesity is very common in patients with type 2 diabetes and is itself associated with an increased risk of fractures at specific sites (humerus, tibia, and ankle). The main mechanisms underlying the bone fragility are an increase in the risk of falls, sarcopenia, disorders of carbohydrate metabolism, vitamin D deficiency, and alterations in cortical bone microarchitecture and bone matrix. The medications used to treat both types of diabetes do not seem to play a major role. Nevertheless, thiazolidinediones and, to a lesser extent, sodium-glucose cotransporter inhibitors may have adverse effects on bone, whereas metformin may have beneficial effects. For the most part, the standard management of bone fragility applies to patients with diabetes. However, emphasis should be placed on preventing falls, which are particularly common in this population. Finally, there is some evidence to suggest that anti-fracture treatments are similarly effective in patients with and without diabetes.     

Pain after posterolateral versus nerve-sparing thoracotomy: A randomized trial

Objectives

Post-thoracotomy pain leads to patient discomfort, pulmonary complications, and increased analgesic use. Intercostal nerve injury during thoracotomy or its entrapment during closure can contribute to post-thoracotomy pain. We hypothesized that a modified technique of posterolateral thoracotomy and closure, preserving the intercostal neurovascular bundle, would reduce acute and chronic post-thoracotomy pain.

Ankle power biofeedback attenuates the distal-to-proximal redistribution in older adults

BackgroundCompared to young adults, older adults walk slower, with shorter strides, and with a characteristic decrease in ankle power output. Seemingly in response, older adults rely more than young on hip power output, a phenomenon known as a distal-to-proximal redistribution. Nevertheless, older adults can increase ankle power to walk faster or uphill, revealing a translationally important gap in our understanding.Research questionOur purpose was to implement a novel ankle power biofeedback paradigm to encourage favorable biomechanical adaptations (i.e. reverse the distal-redistribution) during habitual speed walking in older adults.Methods10 healthy older adults walked at their preferred speeds while real-time visual biofeedback provided target increases and decreases of 10 and 20% different from preferred ankle power. We evaluated the effect of changes in ankle power on joint kinetics, kinematics, and propulsive ground reaction forces. Pre and post overground walking speed assessments evaluated the effect of increased ankle power recall on walking speed.ResultsBiofeedback systematically elicited changes in ankle power; increasing and decreasing ankle power by 14% and 17% when targeting ±20% different from preferred, respectively. We observed a significant negative correlation between ankle power and hip extensor work. Older adults relied more heavily on changes in ankle angular velocity than ankle moment to modulate ankle power. Lastly, older adults walked almost 11% faster when recalling increased ankle power overground.SignificanceOlder adults are capable of increasing ankle power through targeted ankle power biofeedback – effects that are accompanied by diminished hip power output and attenuation of the distal-to-proximal redistribution. The associated increase in preferred walking speed during recall suggests a functional benefit to increased ankle power output via transfer to overground walking. Further, our mechanistic insights allude to translational success using ankle angular velocity as a surrogate to modulate ankle power through biofeedback.     

RP-HPLC法同时测定九味羌活丸、片、颗粒中4种成分

目的建立RP-HPLC法同时测定九味羌活丸、片、颗粒(羌活、防风、苍术等)中羌活醇、阿魏酸、异欧前胡素、紫花前胡苷的含有量。方法 3种药物甲醇提取液的分析采用TechMate C18色谱柱(4.6 mm×250 mm,5μm);流动相乙腈-0.1%冰醋酸,梯度洗脱;体积流量1.0 mL/min;柱温35℃;检测波长317 nm。结果羌活醇、阿魏酸、异欧前胡素、紫花前胡苷分别在2.944 2~31.768 2μg/mL(r=0.999 8)、1.995 8~19.958 4μg/mL(r=0.999 8)、2.944 2~29.441 8μg/mL(r=0.999 7)、8.215 0~82.150 1μg/mL(r=0.999 7)范围内线性关系良好,平均加样回收率分别为94.9%、93.9%、91.2%、101.1%,RSD分别为0.9%、1.2%、1.4%、1.0%。结论该方法准确可靠,可用于九味羌活丸、片、颗粒的质量控制。     

HPLC法同时测定小儿泄泻停颗粒中9种成分

目的建立HPLC法同时测定小儿泄泻停颗粒(羌活、车前子、苍术等)中紫花前胡苷、羌活醇、异欧前胡素、京尼平苷酸、毛蕊花糖苷、异毛蕊花糖苷、苍术素醇、白术内酯Ⅱ、苍术素的含有量。方法该药物甲醇提取液的分析采用Kromasil Eternity C18色谱柱(250 mm×4.6 mm,5μm);流动相乙腈-0.5%冰醋酸,梯度洗脱;体积流量1.0 mL/min;柱温30℃;检测波长254、270、315 nm。结果 9种成分在各自范围内线性关系良好(r≥0.999 1),平均加样回收率96.98%~99.85%,RSD 0.87%~1.57%。结论该方法简便准确,重复性好,可用于小儿泄泻停颗粒的质量控制。