降钙素对骨质疏松大鼠骨密度形态计量学与骨代谢的影响

目的探讨降钙素(密盖息)对骨质疏松大鼠骨密度、骨形态计量学影响以及与血钙、磷、维生素D代谢和生长因子的关系。方法用摘除大鼠双侧卵巢的方式制备骨质疏松模型(OVX),实验动物分为4个组:模型对照组、密盖息治疗组,盐酸雷洛昔芬治疗组,假手术组。应用HOLOGIC第4代双能X线4500W骨密度仪测定大鼠腰椎、股骨上段骨密度值(BMD);以骨形态计量学测股骨骨小梁面积、矿化沉积率;用ELISA法测定血清IGF-1水平和血清25OHVitD浓度以及血淋巴细胞维生素D受体(VDR)含量。结果密盖息治疗组、盐酸雷洛昔芬治疗组均较OVX组腰椎、股骨上段骨密度增高,组间比较差异有显著性(P<0.01)。密盖息治疗组较盐酸雷洛昔芬治疗组股骨上段骨密度增高,两组之间差异有显著性(P<0.01)。密盖息治疗组骨小梁面积明显增加、矿化沉积率增高。密盖息治疗组、盐酸雷洛昔芬治疗组血清IGF-1浓度值、血清25-OHVitD浓度值升高,与OVX组比较差异有显著性(P<0.01)。各组血淋巴细胞VDR含量无明显变化,与OVX组比较差异无显著性(P>0.05)。结论密盖息能够预防腰椎、股骨上段骨密度丢失,使骨小梁面积明显增加、矿化沉积率增高并且血清IGF-1及血清25-OHVitD浓度值升高,但对VDR含量无明显作用。     

Effect of Bone Mineral Density on Rotator Cuff Tear: An Osteoporotic Rabbit Model

IntroductionAn increased bone mineral density (BMD) in the proximity to tendon insertion can improve rotator cuff repair and healing. However, how a decrease of BMD in the humeral head affects the biomechanical properties of the rotator cuff tendon is still unclear. Previous studies have demonstrated ovariectomy in animals to lead to osteoporosis and decreased BMD, and Teriparatide (PTH) administration to improve BMD and strength of bone. This study aimed to explore the correlation between humeral head BMD and infraspinatus (ISP) tendon insertion strength, and if an increase in bone quantity of the humeral head can improve the strength of the rotator cuff.ResultsSignificant differences were observed in the measured humeral head BMD of the Control and OVX-PTH groups compared to the OVX-Saline group (P = 0.0004 and P = 0.0024, respectively). No significant difference was found in failure stress among the three groups, but an expected trend with the control group and OVX-PTH group presenting higher failure strength compared to the OVX-Saline group. BMD at the humeral head showed a positive linear correlation with stress (r² = 0.54). Histology results showed the superiority in OVX-PTH group ISP enthesis compared to the OVX-Saline group.ConclusionBone loss of the humeral head leads to decreased tendon/bone insertion strength of the infraspinatus tendon enthesis. Teriparatide administration can increase bone density of the humeral head and may improve the mechanical properties of the infraspinatus tendon enthesis.     

熊果酸对酒精性骨质疏松大鼠骨形成、骨矿化的影响

目的：探讨熊果酸对酒精所致骨质疏松大鼠骨形成、骨矿化的影响。方法：雄性Wistar大鼠60只,按体重随机分为空白对照 组、熊果酸对照组、模型组、熊果酸低、中、高剂量组,同时分别给予生理盐水、150 mg/kg 熊果酸、50%酒精,50 mg/kg 熊果酸,100 mg/kg 熊果酸,150 mg/kg 熊果酸灌胃。熊果酸对照组生理盐水剂量同空白组,熊果酸低、中、高剂量组酒精剂量同模型组。灌胃共 持续8 周。磷钼酸法检测血清磷(P)含量,比色法检测血清钙(Ca)含量,酶联免疫吸附（ELISA）法检测血清骨钙素(BGP)、骨形成蛋 白-2(BMP-2)浓度;HE 染色法观察股骨结构的病理学变化。结果：与空白对照组相比较,模型组血清BGP、BMP-2 和Ca、P 均明显 降低,且有统计学差异(P < 0.05),但熊果酸对照与空白对照组各项指标结果相近。熊果酸中、高剂量组大鼠血清BGP、Ca 和P 水 平均较模型组有显著升高,差异具有统计学意义(P < 0.05),但仅熊果酸高剂量组血清BMP-2 显著升高(P < 0.05)。股骨组织HE 染色结果显示,空白对照组骨小梁致密、规则且较粗,粗细均匀;模型组骨小梁稀松、不规则、粗细不均匀,甚至可见骨小梁断裂; 熊果酸中、高剂量组骨小梁致密、规则、较厚、粗细均匀,未见骨小梁断裂。结论：熊果酸能够促进酒精性骨质疏松大鼠的骨形成, 抑制骨矿物质的流失,在改善酒精致骨质疏松方面有一定的保护作用。     

Effect of Oxidation Rate and Fe(II) State on Microbial Nitrate-Dependent Fe(III) Mineral Formation

A nitrate-dependent Fe(II)-oxidizing bacterium was isolated and used to evaluate whether Fe(II) chemical form or oxidation rate had an effect on the mineralogy of biogenic Fe(III) (hydr)oxides resulting from nitrate-dependent Fe(II) oxidation. The isolate (designated FW33AN) had 99% 16S rRNA sequence similarity to Klebsiella oxytoca. FW33AN produced Fe(III) (hydr)oxides by oxidation of soluble Fe(II) [Fe(II)_sol] or FeS under nitrate-reducing conditions. Based on X-ray diffraction (XRD) analysis, Fe(III) (hydr)oxide produced by oxidation of FeS was shown to be amorphous, while oxidation of Fe(II)_sol yielded goethite. The rate of Fe(II) oxidation was then manipulated by incubating various cell concentrations of FW33AN with Fe(II)_sol and nitrate. Characterization of products revealed that as Fe(II) oxidation rates slowed, a stronger goethite signal was observed by XRD and a larger proportion of Fe(III) was in the crystalline fraction. Since the mineralogy of Fe(III) (hydr)oxides may control the extent of subsequent Fe(III) reduction, the variables we identify here may have an effect on the biogeochemical cycling of Fe in anoxic ecosystems.     

Effect of Vitamin D on Bone Mineral Mass in Normal Subjects and in Epileptic Patients on Anticonvulsants: A Controlled Therapeutic Trial

The bone mineral mass was estimated by photon absorptiometry in 23 epileptic patients on long-term treatment with phenytoin and in 20 normal subjects before and during treatment with vitamin D or placebo.Initially, subnormal values of bone mineral mass were found in the epileptic patients. The group of epileptic patients treated with vitamin D showed a significant increase in bone mineral mass. The group of epileptic patients treated with placebo and the normal subjects treated with vitamin D or placebo showed no change in bone mineral mass.     

Effect of Supplemental Dietary Zinc on the Mammalian Target of Rapamycin (mTOR) Signaling Pathway in Skeletal Muscle and Liver from Post-absorptive Mice

Zinc (Zn) is an essential trace element that functions in cellular signaling. The mammalian target of rapamycin (mTOR) regulates the initiation of protein synthesis. The objective of this study was to determine whether Zn could stimulate protein phosphorylation in the mTOR pathway in vivo. Mice (C57BL/6J, n = 30) were fed Zn marginal diets (ZM, 5 mg/kg) for 4 weeks, followed by fasting (F) and/or refeeding with ZM or Zn supplemental (300 mg/kg, ZS) diets for 3 or 6 h. Plasma insulin was greater (P < 0.05) in refed animals as compared to F animals. Protein phosphorylation was detected using multiplex analysis and Western blotting. Multiplex analysis indicated greater (P < 0.05) p70 S6 kinase (p70^S6K) and glycogen synthase kinase 3 (GSK-3 α/β) phosphorylation in livers from 6-h refed ZS animals as compared to F animals. Western blots indicated increased (P < 0.05) Akt (Ser 473) phosphorylation in skeletal muscle from animals refed ZS diets for 3 and 6 h as compared to F animals. The ZS diet affected phosphorylation of GSK-3 (α/β) in liver, as 3-h ZS refed animals had greater (P < 0.01) phosphorylation than F animals. These findings indicate that Zn may contribute to the initiation of protein synthesis as a signaling molecule in vivo. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Army or the Department of Defense. Any citations of commercial organizations and trade names in this report do not constitute an official Department of the Army endorsement of approval of the products or services of these organizations.     

Osteopontin调控骨髓间充质干细胞(MSCs)对促进糖尿病足创面愈合的作用

目的:拟以C57糖尿病小鼠为研究对象,建立糖尿病小鼠OPN-/-MSCs组、糖尿病小鼠MSCs组及溶剂组对照组,采用小鼠创面愈合率检测、HE染色、免疫组化等试验方法,观察骨髓间充质干细胞(MSCs)及OPN基因敲除的MSCs对糖尿病小鼠创面愈合的影响.方法:原代提取MSCs及OPN-/-MSCs细胞;利用流式细胞仪检测细胞表面抗原;利用STZ溶液腹腔注射的方法建立糖尿病小鼠模型;将MSCs及OPN-/-MSCs分别注射至小鼠尾静脉,并观察创面愈合情况.结果:成功提取和培养了两组细胞,并成功建立了糖尿病小鼠模型;溶剂组小鼠完全愈合用了19.90± 0.55天,OPN-/-MSCs注射组完全愈合用了18.52±0.75天,MSCs尾静脉注射糖尿病组小鼠用了13.70±0.35天.尾静脉注射MSCs组创面愈合时间明显短于普通糖尿病小鼠组.结论:通过观察三组糖尿病小鼠创面愈合情况,证实MSCs尾静脉注射糖尿病组小鼠比OPN-/-MSCs注射组小鼠和溶剂组小鼠的创面愈合速度快,说明OPN具有调控骨髓间充质干细胞促进创面愈合的作用,为临床治疗糖尿病足提供新的理论依据.     

The Effect of Zinc on the Formation of Ribulose Diphosphate Carboxylase in Phaseolus vulgaris

The effect of Zn on the formation of ribulose diphosphate carboxylase (RuDPCase was investigated in the leaf discs from Zn-deficient Sanilac navy bean plants (Phaseolus rulgaris L.). The incorporation of ¹⁴C-leucine into the partially purified RuDPCase was found to be a quantitative equivalent of the level and activity of the enzyme. Zn as ZnSO₄ at 10 uM stimulates the formation of RuDPCase by at least 2-fold. Neither CuSO₄ nor CdSO₄ at the same concentration substitutes for ZnSO₄. The enhancement of RuDPCase formation by added Zn is greater with increasing severity of Zn deficiency, suggesting that Zn is a limiting factor in this system. Suppression of the Zn-stimulated formation of RuDPCase by actinomycin D and cycloheximide suggests that the Zn-mediated formation of RuDPCase most likely represents de novo synthesis. Also, the possible site(s) of action of Zn is discussed.     

Characteristics of Bone Turnover in the Long Bone Metaphysis Fractured Patients with Normal or Low Bone Mineral Density (BMD)

The incidence of osteoporotic fractures increases as our population ages. Until now, the exact biochemical processes that occur during the healing of metaphyseal fractures remain unclear. Diagnostic instruments that allow a dynamic insight into the fracture healing process are as yet unavailable. In the present matched pair analysis, we study the time course of the osteoanabolic markers bone specific alkaline phosphatase (BAP) and transforming growth factor β1 (TGFβ1), as well as the osteocatabolic markers crosslinked C-telopeptide of type-I-collagen (β-CTX) and serum band 5 tartrate-resistant acid phosphatase (TRAP5b), during the healing of fractures that have a low level of bone mineral density (BMD) compared with fractures that have a normal BMD. Between March 2007 and February 2009, 30 patients aged older than 50 years who suffered a metaphyseal fracture were included in our study. BMDs were verified by dual energy Xray absorptiometry (DXEA) scans. The levels of BTMs were examined over an 8-week period. Osteoanabolic BAP levels in those with low levels of BMD were significantly different from the BAP levels in those with normal BMD. BAP levels in the former group increased constantly, whereas the latter group showed an initial strong decrease in BAP followed by slowly rising values. Osteocatabolic β-CTX increased in the bone of the normal BMD group constantly, whereas these levels decreased significantly in the bone of the group with low BMD from the first week. TRAP5b was significantly reduced in the low level BMD group. With this work, we conduct first insights into the molecular biology of the fracture healing process in patients with low levels of BMD that explains the mechanism of its fracture healing. The results may be one reason for the reduced healing qualities in bones with low BMD.     

The Selective SGLT2 Inhibitor Ipragliflozin Has a Therapeutic Effect on Nonalcoholic Steatohepatitis in Mice

Background & Aims

In recent years, nonalcoholic steatohepatitis (NASH) has become a considerable healthcare burden worldwide. Pathogenesis of NASH is associated with type 2 diabetes mellitus (T2DM) and insulin resistance. However, a specific drug to treat NASH is lacking. We investigated the effect of the selective sodium glucose cotransporter 2 inhibitor (SGLT2I) ipragliflozin on NASH in mice.

Methods

We used the Amylin liver NASH model (AMLN), which is a diet-induced model of NASH that results in obesity and T2DM. AMLN mice were fed an AMLN diet for 20 weeks. SGLT2I mice were fed an AMLN diet for 12 weeks and an AMLN diet with 40 mg ipragliflozin/kg for 8 weeks.

Results

AMLN mice showed steatosis, inflammation, and fibrosis in the liver as well as obesity and insulin resistance, features that are recognized in human NASH. Ipragliflozin improved insulin resistance and liver injury. Ipragliflozin decreased serum levels of free fatty acids, hepatic lipid content, the number of apoptotic cells, and areas of fibrosis; it also increased lipid outflow from the liver.

Conclusions

Ipragliflozin improved the pathogenesis of NASH by reducing insulin resistance and lipotoxicity in NASH-model mice. Our results suggest that ipragliflozin has a therapeutic effect on NASH with T2DM.     

The Effect of HIV-Hepatitis C Co-Infection on Bone Mineral Density and Fracture: A Meta-Analysis

Objective

There is a variable body of evidence on adverse bone outcomes in HIV patients co-infected with hepatitis C virus (HCV). We examined the association of HIV/HCV co-infection on osteoporosis or osteopenia (reduced bone mineral density; BMD) and fracture.

Design

Systematic review and random effects meta-analyses.

Methods

A systematic literature search was conducted for articles published in English up to 1 April 2013. All studies reporting either BMD (g/cm², or as a T-score) or incident fractures in HIV/HCV co-infected patients compared to either HIV mono-infected or HIV/HCV uninfected/seronegative controls were included. Random effects meta-analyses estimated the pooled odds ratio (OR) and the relative risk (RR) and associated 95% confidence intervals (CI).

Results

Thirteen eligible publications (BMD N = 6; Fracture = 7) of 2,064 identified were included with a total of 427,352 subjects. No publications reported data on HCV mono-infected controls. Meta-analysis of cross-sectional studies confirmed that low bone mineral density was increasingly prevalent among co-infected patients compared to HIV mono-infected controls (pooled OR 1.98, 95% CI 1.18, 3.31) but not those uninfected (pooled OR 1.47, 95% CI 0.78, 2.78). Significant association between co-infection and fracture was found compared to HIV mono-infected from cohort and case-control studies (pooled RR 1.57, 95% CI 1.33, 1.86) and compared to HIV/HCV uninfected from cohort (pooled RR 2.46, 95% CI 1.03, 3.88) and cross-sectional studies (pooled OR 2.30, 95% CI 2.09, 2.23).

Conclusions

The associations of co-infection with prevalent low BMD and risk of fracture are confirmed in this meta-analysis. Although the mechanisms of HIV/HCV co-infection’s effect on BMD and fracture are not well understood, there is evidence to suggest that adverse outcomes among HIV/HCV co-infected patients are substantial.     

Delivery of Therapeutic Agents Through Intracerebroventricular (ICV) and Intravenous (IV) Injection in Mice

Despite the protective role that blood brain barrier plays in shielding the brain, it limits the access to the central nervous system (CNS) which most often results in failure of potential therapeutics designed for neurodegenerative disorders ^1,2. Neurodegenerative diseases such as Spinal Muscular Atrophy (SMA), in which the lower motor neurons are affected, can benefit greatly from introducing the therapeutic agents into the CNS. The purpose of this video is to demonstrate two different injection paradigms to deliver therapeutic materials into neonatal mice soon after birth. One of these methods is injecting directly into cerebral lateral ventricles (Intracerebroventricular) which results in delivery of materials into the CNS through the cerebrospinal fluid ^3,4. The second method is a temporal vein injection (intravenous) that can introduce different therapeutics into the circulatory system, leading to systemic delivery including the CNS ⁵. Widespread transduction of the CNS is achievable if an appropriate viral vector and viral serotype is utilized. Visualization and utilization of the temporal vein for injection is feasible up to postnatal day 6. However, if the delivered material is intended to reach the CNS, these injections should take place while the blood brain barrier is more permeable due to its immature status, preferably prior to postnatal day 2. The fully developed blood brain barrier greatly limits the effectiveness of intravenous delivery. Both delivery systems are simple and effective once the surgical aptitude is achieved. They do not require any extensive surgical devices and can be performed by a single person. However, these techniques are not without challenges. The small size of postnatal day 2 pups and the subsequent small target areas can make the injections difficult to perform and initially challenging to replicate. Download video file.^{(37M, mov)}     

The Effect of Light on Tobacco Mosaic Virus (TMV) Formation

Discs were punched from TMV-inoculated tobacco leaves (Nicotiana tabacum L.) and illuminated while floating on half strength Vickery's solution maintained at 24°C. After 48 hours some discs were placed in the dark for 24 hours and the amount of TMV formed in the light and dark compared. Discs from young leaves formed more virus in the light than in the dark. Discs from older leaves produced less virus, but as much in the dark as in the light.     

Effect of Simvastatin Use on Bone Mineral Density in Women with Type 2 Diabetes

ObjectiveTo attempt to clarify the effect of simvastatin, a widely used statin, on the bone mineral density in women with type 2 diabetes.MethodsWe performed a cross-sectional, controlled study of 37 women with type 2 diabetes who were taking simvastatin. Each woman was matched with 2 control subjects who were closest in age, years since menopause (if applicable), and duration of diabetes on the date on which the examination was performed. We measured bone mineral density at the spine and the hip with a dual-energy x-ray absorptiometry scanner and compared bone density in the 2 study groups.ResultsThe mean bone mineral density values of patients in the simvastatin group were found to be slightly increased in comparison with those of the control group, both in the lumbar vertebrae and in the femoral neck, but these differences were not statistically significant (P > 0.05).ConclusionIn this cross-sectional study, we could not demonstrate a positive effect of long-term simvastatin treatment on bone mineral density in women with type 2 diabetes and hypercholesterolemia. (Endocr Pract. 2007; 13:114-116)     

丙戊酸钠对LPS诱导的急性呼吸窘迫综合征小鼠的治疗作用

为了探讨丙戊酸钠(valproic acid,VPA)对急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)小鼠治疗作用及分子机制,本研究将30只雌性C57BL/6小鼠分为空白组、LPS组、LPS+VPA组,LPS+VPA组小鼠造模前腹腔预注射VPA,以LPS气管内注射诱导ARDS小鼠模型,6 h后检测各组小鼠肺水肿(湿重/干重),检测各组小鼠血液SOD和MDA水平;通过ELISA检测各组小鼠肺泡灌洗液中TNFα和IL-1β水平,Western blotting检测各组小鼠NF-κB p65和p-H2A.X蛋白表达水平。研究结果表明:与空白组相比,LPS组小鼠肺水肿显著升高,与LPS组比较,LPS+VPA组和阳性组小鼠肺水肿显著降低,差异具有统计学意义(p<0.01)。ELISA结果显示,与空白组比较,LPS组小鼠肺组织TNFα和IL-1β含量显著升高,与LPS组比较,LPS+VPA组小鼠肺组织TNFα和IL-1β含量显著降低,差异具有统计学意义(p<0.01)。与空白组比较,LPS组小鼠血液SOD活性显著降低,MDA含量显著升高,与LPS组比较,LPS+VPA组和阳性组小鼠血液SOD活性显著升高,MDA含量显著降低。Western blotting结果显示,与空白组比较,LPS组小鼠肺NF-κB p65和p-H2A.X蛋白表达显著升高,与LPS组比较,LPS+VPA组和阳性组小鼠肺NF-κB p65和p-H2A.X蛋白表达显著降低,差异具有统计学意义(p<0.01)。本研究初步表明:VPA能够抑制NF-κB通路,抑制小鼠氧化应激和炎症反应,保护ARDS小鼠肺组织。     

The Phosphate Transporter from Pea Mitochondria (Isolation and Characterization in Proteolipid Vesicles)

The phosphate transporter from mitochondria will exchange matrix phosphate for cytosolic phosphate and facilitate either phosphate/proton symport or phosphate/hydroxyl ion antiport. The phosphate transported into the matrix by this carrier is either used for ATP synthesis or exchanges back out to the cytosol on the dicarboxylate transporter, permitting entry of malate and succinate into the matrix. The phosphate transporter was solubilized from etiolated pea (Pisum sativum L. cv Alaska) mitochondrial membranes with Triton X-114, purified approximately 500-fold by hydroxylapatite chromatography, and reconstituted into azolectin vesicles that were preloaded with 0.1 or 10 mM phosphate. Phosphate transport was measured as the exchange of preloaded phosphate for external [32P]phosphate. Phosphate/phosphate exchange occurred for over 40 min at room temperature with an apparent K0.5 of 1.6 mM and a maximum velocity of over 700 nmol (mg protein)-1 min-1. Diethyl pyrocarbonate was used as an inhibitor-stop reagent. Transport was inhibited by p-hydroxyphenylglyoxal, p-hydroxymercuribenzoate, pyridoxal 5-phosphate, and dansyl chloride but was insensitive to sulfate, nitrate, and N-ethylmaleimide, the standard inhibitor for the mammalian phosphate transporter. Phosphate/hydroxyl exchange was stimulated when the proton gradient was collapsed with carbonyl cyanide m-chlorophenylhydrazone, but phosphate/phosphate exchange was unaffected by the uncoupler.     

离子对反相HPLC测定小鼠骨髓BFU—E,CFU—E中PRPP合成酶活性

采用离子对反相高效液相色谱法（ＩＰｒＨＰＬＣ）的单液等度洗脱,测定了小鼠骨髓红系爆增性集落形成单位（ＢＦＵ－Ｅｓ）与红系集落形成单位（ＣＦＵ－Ｅｓ）的ＰＲＰＰ合成酶活性。方法学研究表明,加入离子对试剂硫酸氢四丁基铵（ＴＢＡＨＳ）后,ＡＤＰ谱峰分离完全,其反应增加量易于计算。本法的批内变异系数平均值为－２．３０％￣－１．０６％与１．０６％￣２．３０％,平均相对偏差为０．８１％￣１．７４％,回收率为９     

离子对反相HPLC测定小鼠骨髓BFU-E、CFU-E中PRPP合成酶活性

采用离子对反相高效液相色谱法 ( IPr HPLC)的单液等度洗脱 ,测定了小鼠骨髓红系爆增性集落形成单位 ( BFU- Es)与红系集落形成单位 ( CFU- Es)的 PRPP合成酶活性 .方法学研究表明 ,加入离子对试剂硫酸氢四丁基铵 ( TBAHS)后 ,ADP谱峰分离完全 ,其反应增加量易于计算 .本法的批内变异系数平均值为 - 2 .30 %～ - 1 .0 6%与 1 .0 6%～ 2 .30 % ,平均相对偏差为 0 .81 %～ 1 .74% ,回收率为 93.9%～ 98.5% ,能达到操作简便、灵敏和准确的要求 .采用本法测得 2 0只正常昆明小鼠的 BFU- E和 CFU- E中该酶活性各为 ( 0 .563± 0 .0 2 7)μmol/( min·g· m L- 1)与 ( 0 .41 6± 0 .0 2 6) μmol/( min·g·m L- 1) .