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1.
绝经后健康妇女甲状旁腺激素基因多态性与骨密度的关系   总被引:11,自引:1,他引:10  
李东  董兆文  薛延  王芊 《遗传》2003,25(2):133-136
利用限制性片段长度多态性分析(RFLP)研究北京地区绝经后妇女甲状旁腺激素(PTH)基因多态性与骨密度的关系。筛选健康、无亲缘关系的绝经后妇女185例, 应用双能X射线骨密度仪(DEXA)检测腰椎等部位的骨密度,用PCR-RFLP方法检测绝经后妇女的PTH基因型。绝经后健康妇女中bb、Bb、BB三种基因型的分布频率分别为7.56%、28.11%和64.32%。方差分析显示前臂部位骨密度与PTH基因相关。除华氏三角区外,BB基因型各部位的骨密度值均高于Bb、bb基因型。Logistic回归分析结果显示,bb基因型组骨质疏松与正常妇女存在显著差异(P<0.001)。 PTH基因中B基因型可能对维持骨量具有一定的作用。  相似文献   

2.
模拟青霉素分批补料发酵过程的细胞自动机模型   总被引:2,自引:0,他引:2  
根据青霉素产生菌的生长机理和青霉素分批补料发酵过程的动力学特性,在Paull等建立的形态学结构动力学模型的基础上,建立了模拟青霉素分批补料发酵过程的细胞自动机模型。模型采用三维细胞自动机作为菌体生长空间,采用Moore型邻域作为细胞邻域,其演化规则根据青霉素分批补料发酵过程中菌体生长机理和简化动力学结构模型设计。模型中的每一个细胞既可代表单个产黄青霉菌体细胞,又可代表特定数量的这种菌体细胞,它具有不同的状态。对模型进行的仿真实验结果表明:模型不但能一致地复现形态学结构动力学模型所描述的青霉素分批补料发酵过程的演化特性,而且较形态学结构动力学模型更加直观地刻画了青霉素分批补料发酵过程的演化行为。最后,对所建模型在实际生产过程中的应用问题进行了分析,指出了需要进一步研究的问题。  相似文献   

3.
甲状旁腺素对成骨样细胞增殖的调节作用   总被引:3,自引:1,他引:3  
甲状旁腺素(PTH)是调节钙磷代谢的经典激素,有报道PTH对其靶细胞-成骨细胞有促增殖分化作用。经多层次、多水平的实验研究证实,PTH对成骨样细胞ROS17/2.8确有促增殖作用。(1)细胞计数、MTT[3-(4,5-dimethylthia-zol-z-yi)2,5-diphenyltetrazoliumbromide]测定及SRB(sodiumrhodamineB,SRB)染色均显示经PTH(10-9mol/L)处理的细胞,其数目明显增加;(2)3H-TdR参入增加;(3)与增殖相关的原癌基因(c-fos、c-jun、c-ki-ras和c-myc)的表达增强;(4)成骨细胞特征性蛋白-碱性磷酸酶活性降低.这些结果不仅表明该激素具有非经典样作用,同时意味着激素也参与其靶细胞增殖分化的调节作用  相似文献   

4.
1989年Lewanczuk等[1]报道在自发性高血压大鼠(spontaneouslyhvnertensiverat,SHR)的血浆中发现一种具有独特升压效应的高血压因子.通过激活平滑肌细胞膜钙通道,提高细胞内游离钙([Ca2 ])水平起作用.随之证明这种循环血中的高血压因子来源于甲状旁腺,故称“甲状旁腺高血压因子(Parathyroidhypertensivefactor,PHF)”[2]。我们经实验研究证明,当给SD(Sprague-Dawley)大鼠注射经透析的SHR血浆后30min其血压开始升高,45min达高峰,60min恢复到注射前水平.同时经透析的血浆可使SD大鼠尾动脉条的细胞45Ca2 摄取增加,其…  相似文献   

5.
We investigated whether lowering food intake by high phosphorus (P) diet influenced parathyroid hormone (PTH) actions, bone turnover markers, and kidney mineral concentration in rats. Rats in two of the three groups were respectively given free access to a control diet (C group) and a high P diet (HP group) for 21 days. Rats in another group (PF group) were pair-fed the control diet with the HP group. Compared to the C and PF groups, serum PTH concentration, urinary C-terminal telopeptide of type I collagen excretion, and kidney calcium and P concentrations were significantly higher in the HP group. Urinary excretion of cAMP was significantly lower in the HP group than in the C and PF groups. These results suggested that high P diet decreased PTH action in the kidney and increased bone resorption and kidney mineral concentrations independently of lowering food intake.  相似文献   

6.
《Endocrine practice》2021,27(4):342-347
ObjectiveOur objective was to analyze the effect of radioiodine (RAI) therapy on parathyroid hormone (PTH) secretion.MethodsA total of 137 patients were included and divided into 2 groups based on pretherapy PTH levels. The residual thyroid tissue volume was classified into 4 grades (0-3), and a value of 0 indicated that there was no apparent residual tissue. We analyzed the PTH level changes among different time points in each group and the factors that could predict the PTH level changes.ResultsIn 113 patients with normal parathyroid gland function, the PTH level at baseline, 1 day, 7 days, 1 month, 3 months, and 6 months after RAI therapy did not show any significant difference; in 24 patients with decreased parathyroid gland function, the level of PTH immediately decreased after the implementation of RAI therapy but gradually returned to a pre-RAI therapy level within 6 months. On the seventh day after therapy, the mean value of PTH in patients with a residual thyroid tissue volume of extent of 0/1 was 8.0 ± 2.3 pg/mL, which was significantly higher than that in patients with a residual thyroid tissue volume of extent of 2/3 (P = .011). Similar phenomena were observed 1 month, 3 months, and 6 months after therapy.ConclusionRAI therapy had a significant transient adverse effect on parathyroid gland function in patients with decreased PTH secretion pretherapy, and the extent was associated with the amount of residual thyroid tissue.  相似文献   

7.
The control by bone metabolism of the blood calcium level in young rats may be described in terms of a regulator-type system. The model presented here comprises a feedback loop involving only a proportional control in thyroparathyroidectomized, and a combination of proportional and integral controls in normal animals. It accounts for the variations observed when the system was subjected to a variety of experimental constraints. The implications, limitations, and possible extensions of the model are discussed.  相似文献   

8.
以苦瓜常规品种“绿爵士”为试材,在日光温室内于幼苗3-4叶期叶面喷施乙烯利溶液,通过高效液相色谱串联质谱(HPLC-MS/MS)仪测定了相关内源激素的含量,并结合高通量测序技术对相关调控基因表达进行分析,探究外源乙烯利对苦瓜幼苗激素代谢的影响,获得苦瓜应对外源乙烯诱导的内源激素代谢靶点,初步明确相关调控基因的作用特点,为深入开展苦瓜类作物外源乙烯调控机制的研究奠定基础。结果表明:(1)在外源乙烯利作用下,苦瓜幼苗植株内源乙烯合成直接前体物质1-氨基环丙基-1-羧酸(ACC)含量和主要限速酶ACC合成酶(ACS)活性均表现为显著升高的趋势;内源生长素(IAA)和细胞分裂素(tZR)的含量同样显著升高,而其赤霉素(GA3)的含量则显著降低。(2)经过Hi-seq测序,共获得1234个差异表达基因(DEGs),功能富集分析显示有570个DEGs富集于118条代谢通路中。(3)对所有DEGs进行功能注释,鉴定了多个参与内源激素合成及信号转导的基因,包括乙烯代谢相关的ACS、ACO、HMT3、EIN3、ERFs基因,IAA代谢相关的ALDH、TAA1、UGT74B1、AUX/IAA、ARF等基因,细胞分裂素代谢相关的CYP735A、CKX、A-ARR基因,以及GA3代谢相关的KAO1、CYP736A12-like、GID1、PIF3基因。(4)qRT-PCR分析表明,所挑选的8个基因的表达趋势与转录组log2FC值变化趋势一致,其中4个基因为上调表达,另外4个基因下调表达。  相似文献   

9.
膜上G蛋白偶联受体(GPCRs)是骨细胞感知外部信号刺激的关键跨膜蛋白,因其在成骨细胞(OB)、软骨细胞和破骨细胞(OC)分化和功能发挥上扮演的关键角色而在骨代谢研究领域备受关注。GPCRs功能缺失或异常升高后,骨细胞内环境稳态失衡,导致OB、软骨细胞和OC分化及代谢紊乱,骨组织微细结构退化。运动通过促进骨形成并抑制骨吸收来改善骨代谢,其机制与GPCRs (如GPR48、GPR54、GPR30等)介导的关键信号途径(cAMP/PKA/Atf4、JNK/AP-1、ERK1/2等)和细胞因子(T-PINP、Nkx3.2、Sox9和Cleaved-caspase-3等)调控下游级联反应来影响OB、软骨细胞和OC分化或功能密切相关。本文通过梳理GPCRs在运动改善骨代谢中的可能机制,有助于筛选出膜上敏感GPCRs来作为骨代谢疾病药物研发“效应器”以及运动干预中的力学刺激“明星蛋白”,为骨质疏松的研究和防治提供更多靶点或视角。  相似文献   

10.
目的:探究生长激素对特发性矮小(idiopathic short,ISS)的作用及临床疗效。方法:在我院临床接受ISS治疗的病患中,随机选取84例作为研究对象。按照随机分组法把其分为观察组(44例)和对照组(40例)。对照组进行常规治疗。观察组每日睡前注射生长激素0.16—0.20IU/kg。对比分析两组病患治疗后身高、身高标准差及生长速率情况。结果:对照组治疗后无明显增高现象,而观察组增高现象显著。差异均有统计学意义(均P0.05)。观察组疗效优者占63.6%(28/44),优良率为95.5%(42/44),均明显高于对照组的35%(14/40),80%(32/40),差异均有统计学意义(均P0.05)。结论:生长激素用于治疗ISS病患疗效显著,并能有效改善ISS病患身高、生长速率,安全性有保证,值得临床治疗广泛推荐。  相似文献   

11.
目的探讨羊骨酶解发酵液钙螯合物(SBEF-Ca)对雌激素缺乏造成的骨质疏松的防治作用。方法 40只3.5月龄的Sprague-Dawley大鼠,按体重随机分为正常组(假手术+蒸馏水)、模型对照组(去卵巢+蒸馏水)和高、中、低3个剂量组(去卵巢+SBEF-Ca)。术后12 d,持续灌胃11周后,测定股骨密度、长度以及血清中反映骨代谢的主要生化指标。结果模型对照组大鼠股骨密度和长度显著减小,各剂量组均可扭转这种减小趋势并使股骨密度和长度维持在正常组水平,其中高剂量组的股骨密度显著大于中、低剂量组;各剂量组的股骨长度差异不显著;所有大鼠的血Ca、血P水平差异无显著性;模型对照组的血清碱性磷酸酶(ALP)、骨钙素(BGP)水平明显升高,而各剂量组的ALP、BGP水平与正常组差异不显著,且高剂量组ALP水平显著低于中、低剂量组,中、高剂量组的BGP水平(P〉0.05)显著低于低剂量组。结论低、中、高剂量的SBEF-Ca对绝经后骨质疏松症有预防作用。  相似文献   

12.
摘要 目的:探讨重组人生长激素(rhGH)对特发性矮小(ISS)患儿的治疗效果,并建立rhGH治疗后生长速率(GV)的预测模型。方法:回顾性分析确诊为 ISS并应用rhGH治疗1年的130例患儿的疗效,以治疗12个月后的GV为因变量,采用多元逐步回归方法建立ISS患儿疗效的预测模型。结果:rhGH治疗6个月、12个月的身高、身高标准差分值(HtSDS)均逐渐升高(P<0.05),治疗12个月的身高增长(△Ht)、GV 低于治疗 6个月(P<0.05)。治疗6个月、治疗12个月的GV 均与初始治疗时的生活年龄(CA)、骨龄(BA)、身高、体重及垂体高度呈负相关(P<0.05)。将治疗12个月GV 作为因变量,治疗前初始身高(X1)、治疗6个月GV(X2)被纳入方程建立预测模型:Y=7.631-0.035X1+0.567X2,R2=0.791,并通过内外部验证。结论:rhGH治疗对ISS患儿的身高增长具有良好效果,前6个月的效果更好。rhGH治疗后ISS患儿的GV与治疗前CA、BA、身高、体重及垂体高度呈负相关。治疗前的身高、治疗6个月的GV能够较好地预测治疗12个月的GV。  相似文献   

13.
Abstract

In this work, a complete internal-external bone-remodelling scheme is presented and implemented into a finite element code. This model uses a combination of an anisotropic internal remodelling model based on a new Continuum "Damage-Repair" theory and an external adaptation approach that follows the idea, early introduced by Mattheck et ah, to simulate the growth behaviour of biological systems, known as CAO method. This combined scheme qualitatively resembles most of the main features of the bone adaptive behaviour, like the bone mass distribution (heterogeneity and porosity), the directional internal structure (anisotropy), the alignment of the microstructure with the constitutive principal directions and these with those of the stress tensor when permanently loaded by a unique stress state (WolfFs law). It is also thermodynamically consistent, fulfilling a principle of minimum mechanical dissipation. Finally, the comparison between the predicted results and the ones obtained by different experimental tests allows us to conclude that this model is able of reproducing qualitatively the global behaviour of bone tissue when subjected to external mechanical loads.  相似文献   

14.
源记忆是对信息来源(例如信息获取的媒介和感觉通道)的记忆.情绪刺激是能使个体产生正性或负性情绪的刺激.已有研究所揭示的情绪刺激对源记忆的影响不尽相同.综合情绪刺激对源记忆影响的研究成果,阐述注意资源缩减理论和优先捆绑理论,并基于情绪刺激增强、减弱和不影响源记忆三种实验现象总结现有相关实验研究,指出现有研究存在的局限,并对未来研究进行展望.  相似文献   

15.
 间歇性小剂量地给予甲状旁腺素 (parathyroid hormone,PTH)可促进成骨 .胰岛素样生长因子 - I(insulin- like growth factor- I,IGF- I)由成骨细胞所产生并贮存于骨基质中 ,可促进成骨细胞的增殖分化 .为进一步了解向钙性激素和骨源性生长因子对骨生长的影响 ,利用成骨样细胞 ROS1 7/ 2 .8进行体外实验 ,观察了 PTH和 IGF- I这两种在骨生长和代谢中有重要作用的激素和因子相互作用的效果 ,并对其相互作用机制作出初步探讨 .结果显示 :联合使用 IGF- I及 PTH(间歇性给药 )时 ,(1 ) SRB(sodium rhodamine B,SRB)染色显示经 PTH(1 0 -9mol/ L,间歇给药 )和 IGF- I(1 0 -9mol/ L)联合处理的细胞 ,其数目明显增加 ,且明显高于单独处理组 ;(2 ) 3H- Td R参入增加 ,也明显高于单独处理组 ;(3)与增殖相关的原癌基因 (c- fos,c- jun,c- ki- ras)的表达增强 ,明显高于单独处理组 ;(4)骨钙素 (osteocalcin)基因 m RNA表达增强 ,明显高于单独处理组 ;(5) IGF- I(1 0 -8mol/L,1 0 -9mol/ L)可使 PTH受体基因 m RNA表达增强 .这些结果提示 PTH和 IGF- I在成骨样细胞ROS 1 7/ 2 .8增殖分化中具有协同作用 ,原癌基因的表达增强可能是其作用的一个环节 .此外 ,IGF- I可能通过增强 PTH受体表达 ,使细胞对 PTH的反应性增强  相似文献   

16.
目的:建立稳定的异基因骨髓移植GVHD(移植物抗宿主病)动物模型,并初步了解其病理生理学机制。方法:以BALB/c(H-2^d)雌性小鼠为受者,接受8Gy致死剂量的。Co全身照射后,输注雄性C57BL/6(H-2^b)供鼠的脾细胞和骨髓细胞,观察受鼠的体征、造血功能恢复及生存时间的变化,并进行病理学、嵌合体和T细胞亚群及相关细胞因子的检查。结果:模型组小鼠在移植后出现了典型的GVHD症状;肠、肝、脾、皮肤的病理学分析均属于Ⅳ度GVHD;嵌合体植入成功;以7、14和21d为检测时间点,发现模型组鼠体内T细胞亚群移植后较移植前CD3^+CD4^+T细胞数量减少,CD3+CD8+T细胞显著升高,CD4^+和CD8^+T细胞比例严重倒置,随着时间变化比值会逐渐升高,但仍然处于较显著的倒置水平;血清中IFN-γ、TNF-α在移植后+7d表达显著增高,尤其是IFN-γ的表达在+7d达峰值;IL-4和IL-10的水平在移植前后几乎没有变化。结论:建立了稳定的GVHD动物模型;此模型发病过程中,CD8^+T细胞介导的CTL细胞毒性作用可能要大于CD4+Th介导的细胞因子效应;IFN-γ、TNF-α炎症因子在GVHD的早期发挥重要作用;IL-4、IL-10的低水平分泌与急性GVHD的高发病率有关。  相似文献   

17.
《Endocrine practice》2021,27(11):1065-1071
ObjectivePersistent secondary hyperparathyroidism (SHPT) may occur because of residual cervicothoracic parathyroids in parathyroidectomy (PTX) patients with chronic kidney disease. We prospectively compared the predictive values of intraoperative plasma (1-84) parathyroid hormone (PTH) and intact PTH (iPTH) levels to improve the safety and efficacy of PTX.MethodsWe included 100 healthy controls, 162 stage 5 chronic kidney disease patients without SHPT, and 214 patients who underwent PTX because of SHPT. Plasma iPTH and (1-84) PTH levels were measured before incision (io-iPTH0 and io-[1-84]PTH0, respectively) and 10 minutes (io-iPTH10 and io-[1-84]PTH10, respectively) and 20 minutes (io-iPTH20 and io-[1-84]PTH20, respectively) after removing all parathyroids. The percentage reduction of iPTH and (1-84) PTH at 10 minutes (io-iPTH10% and io-[1-84]PTH10%, respectively) and 20 minutes (io-iPTH20%, and io-[1-84]PTH20%, respectively) was calculated. iPTH and (1-84) PTH were measured using second- and third-generation PTH assays, respectively.ResultsCompared with the controls and non-PTX patients, the PTX group had more obvious mineral metabolism disorders. There were 187 successful PTXs, 19 patients with persistent SHPT, and 8 patients lost to follow-up. The receiver operating characteristic curves revealed that io-(1-84)PTH10% >86.6% and io-(1-84)PTH20% >87.5% suggested successful PTX. The sensitivity of io-iPTH20% and io-(1-84)PTH20% were higher than those at the timepoint of 10 minutes. Moreover, the specificity and sensitivity of the (1-84) PTH reduction percentage were superior to that of iPTH.ConclusionIntraoperative reduction percentages of plasma (1-84) PTH levels are superior to iPTH for accurately predicting successful PTX, especially at 20 minutes after all cervicothoracic parathyroids had been resected.  相似文献   

18.
Bone remodeling simulation is an effective tool for the prediction of long-term effect of implant on the bone tissue, as well as the selection of an appropriate implant in terms of architecture and material. In this paper, a finite element model of proximal femur was developed to simulate the structures of internal trabecular and cortical bones by incorporating quantitative bone functional adaptation theory with finite element analysis. Cementless stems made of titanium, two types of Functionally Graded Material (FGM) and flexible ‘iso-elastic’ material as comparison were implanted in the structure of proximal femur respectively to simulate the bone remodeling behaviors of host bone. The distributions of bone density, von Mises stress, and interface shear stress were obtained. All the prosthetic stems had effects on the bone remodeling behaviors of proximal femur, but the degrees of stress shielding were different. The amount of bone loss caused by titanium implant was in agreement with the clinical observation. The FGM stems caused less bone loss than that of the titanium stem, in which FGM I stem (titanium richer at the top to more HAP/Col towards the bottom) could relieve stress shielding effectively, and the interface shear stresses were more evenly distributed in the model with FGM I stem in comparison with those in the models with FGM II (titanium and bioglass) and titanium stems. The numerical simulations in the present study provided theoretical basis for FGM as an appropriate material of femoral implant from a biomechanical point of view. The next steps are to fabricate FGM stem and to conduct animal experiments to investigate the effects of FGM stem on the remodeling behaviors using animal model.  相似文献   

19.
Abstract: We have developed an in vitro system for the study of the release of luteinizing hormone-releasing hormone (LH-RH) from its storage granules. In this system, homogenates of hypothalamic tissue are subjected to hypoosmotic shock, and the LH-RH-containing granules are isolated by means of differential centrifugation. The isolated granules are then incubated in a buffered medium, and the incubation is terminated by passing the incubation mixture through LH-RH affinity columns. The LH-RH associated with the granules passes freely through the columns, whereas the LH-RH released into the medium binds to the columns and is subsequently eluted with an acid solution. LH-RH is quantified by radioimmunoassay (RIA). We tested the effects of various concentrations of KCl on LH-RH release, which was found to be dependent on the concentration of KCl in the medium over the range 40–160 mM. We then studied the effects of pH on the release of LH-RH. Incubation of granules at pH 7.8 in the presence of 160 mM-KC1 resulted in the release from the granules of 14% of the stored LH-RH, whereas incubation at pH 6.2 resulted in the release of approximately 30% of the LH-RH. In addition, granules were incubated at pH 7.8 with MgATP and KCl. MgATP elicited a marked release of LH-RH that was approximately twice that seen in the absence of MgATP. In summary, in this in vitro system, granules containing LH-RH are stable under defined biochemical conditions, and LH-RH release from these granules is stimulated by ions and MgATP.  相似文献   

20.
在杀虫剂作用下的一类具有Allee效应的天敌-害虫模型   总被引:4,自引:0,他引:4  
对一类具有Allee效应的天敌-害虫模型作了理论分析,同时对在杀虫剂作用下的此系统又作了理论分析,比较了二者之间的区别,从而从理论上获知利用杀虫剂控制虫害的利弊.  相似文献   

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