BACKGROUND & AIMS: OBJECTIVE:The aim of this study was to assess the relative influence of age and edentulousness upon mandibular bone mineral density (BMD) in a sample of dentate and edentulous female subjects. STUDY DESIGN:Seventy-two patients (43-79 years of age; mean age, 62.5 years), of whom 49 were edentulous and 23 dentate, underwent dual x-ray energy absorptiometry (DXA) to determine the BMD of the body of mandible. Mandibular BMD was measured using DXA. The investigators independently determined rectangular regions of interest (ROIs) on the mandibular images, and the computer calculated the BMD of these specified regions. For the dentate patients, the ROIs were placed to exclude the roots of teeth. RESULTS:A linear multiple regression model was fitted to the dependent variable, mandibular body BMD, with age and whether the patient was edentulous or dentate being explanatory factors in the statistical model. The variable describing the dentate/edentulous state was not significant in the statistical model (P = .91). The model showed that age was significantly related negatively to the BMD of the mandibular body (P = .01). CONCLUSION:Age was a predictor of mandibular BMD but edentulousness was not.

背景与目标：

BACKGROUND & AIMS: :High salinity causes ion imbalance and osmotic stress in plants. Leaf sections from 8-d-old dark-grown wheat (Triticum aestivum cv. Giza 168) were exposed to high salt stress (600 mM) and the native arrangements of plastid pigments together with the ultrastructure of the plastids were studied using low-temperature fluorescence spectroscopy and transmission electron microscopy. Although plastids from salt-treated leaves had highly swollen prothylakoids (PTs) the prolamellar bodies (PLBs) were regular. Accordingly, a slight intensity decrease of the short-wavelength protochlorophyllide (Pchlide) form was observed, but no change was found in the long-wavelength Pchlide form emitting at 656 nm. After irradiation, newly formed swollen thylakoids showed traversing stromal strands. The PLB dispersal was partly inhibited and remnants of the PLBs formed an electron-dense structure, which remained after prolonged (8 h) irradiation. The difference in fluorescence emission maximum of the main chlorophyll form in salt-stressed leaves (681 nm) and in control leaves (683 nm) indicated a restrained formation of the photosynthetic apparatus. Overall chlorophyll accumulation during prolonged irradiation was inhibited. Salt-stressed leaves returned to darkness after 3 h of irradiation had, compared with the control, a reduced amount of Pchlide and reduced re-formation of regular net-like PLBs. Instead, the size of the electron-dense structures increased. This study reports, for the first time, the salt-induced swelling of PTs and reveals traversing stromal strands in newly formed thylakoids. Although the PLBs were intact and the Pchlide fluorescence emission spectra appeared normal after salt stress in darkness, plastid development to chloroplasts was highly restricted during irradiation.

背景与目标： : 高盐度导致植物离子失衡和渗透胁迫。将8-d龄深色小麦 (Triticum aestivum cv。Giza 168) 的叶片切片暴露于高盐胁迫 (600 mM) 下，并使用低温研究了质体色素的天然排列以及质体的超微结构。荧光光谱和透射电子显微镜。尽管盐处理过的叶子中的质体具有高度肿胀的前类囊体 (PTs)，但层状体 (plb) 是规则的。因此，观察到短波长原叶绿素 (Pchlide) 形式的轻微强度降低，但在656 nm处发射的长波长Pchlide形式中没有发现变化。辐照后，新形成的肿胀类囊体显示出横穿的基质链。PLB的扩散受到部分抑制，PLB的残留物形成了电子致密结构，该结构在长时间 (8 h) 照射后仍保留。盐胁迫叶片 (681 nm) 和对照叶片 (683 nm) 中主要叶绿素形式的荧光发射最大值的差异表明光合装置的形成受到限制。长时间照射期间的总叶绿素积累受到抑制。与对照相比，辐射3小时后，盐胁迫的叶子恢复到黑暗中，减少了克利德的量，并减少了常规网状plb的重新形成。相反，电子致密结构的大小增加了。这项研究首次报告了盐诱导的PTs肿胀，并揭示了新形成的类囊体中穿越的基质链。尽管plb完好无损，并且在黑暗中的盐胁迫后，Pchlide荧光发射光谱似乎正常，但在辐照过程中，质体向叶绿体的发育受到高度限制。

BACKGROUND & AIMS: :Inappropriate activation of the intrarenal renin-angiotensin system induces generation of reactive oxygen species and tubulointerstitial inflammation, which contribute to salt-sensitive hypertension (SSHT). Liver-type fatty acid-binding protein is expressed in proximal tubules in humans, but not in rodents, and may play an endogenous antioxidative role. The objective of the present study was to examine the antioxidative effect of liver-type fatty acid-binding protein on post-angiotensin II SSHT model in transgenic mice with selective overexpression of human liver-type fatty acid-binding protein in the proximal tubules. The transgenic mice showed marked protection against angiotensin II-induced SSHT. Overexpression of tubular liver-type fatty acid-binding protein prevented intrarenal T-cell infiltration and also reduced reactive oxygen species generation, intrarenal renin-angiotensin system activation, and monocyte chemotactic protein-1 expression. We also performed an in vitro study using the murine proximal tubular cell lines with or without recombinant liver-type fatty acid-binding protein and murine proximal tubular cell lines transfected with human liver-type fatty acid-binding protein, and found that gene transfection of liver-type fatty acid-binding protein and, in part, recombinant liver-type fatty acid-binding protein administration had significantly attenuated angiotensin II-induced reactive oxygen species generation and the expression of angiotensinogen and monocyte chemotactic protein-1 in murine proximal tubular cell lines. These findings indicated that liver-type fatty acid-binding protein in the proximal tubules may protect against angiotensin II-induced SSHT by attenuating activation of the intrarenal renin-angiotensin system and reducing oxidative stress and tubulointerstitial inflammation. Present data suggest that liver-type fatty acid-binding protein in the proximal tubules may be a novel therapeutic target for SSHT.

背景与目标： : 肾内肾素-血管紧张素系统的不适当激活会导致活性氧和肾小管间质炎症的产生，从而导致盐敏感性高血压 (SSHT)。肝型脂肪酸结合蛋白在人类近端小管中表达，但在啮齿动物中不表达，并且可能发挥内源性抗氧化作用。本研究的目的是研究肝型脂肪酸结合蛋白对血管紧张素II后SSHT模型的抗氧化作用，该模型在近端小管中选择性过表达人肝型脂肪酸结合蛋白。转基因小鼠对血管紧张素II诱导的SSHT具有明显的保护作用。肾小管型脂肪酸结合蛋白的过表达阻止了肾内T细胞的浸润，并减少了活性氧的产生，肾内肾素-血管紧张素系统的激活和单核细胞趋化蛋白-1的表达。我们还使用带有或不带有重组肝型脂肪酸结合蛋白的鼠近端肾小管细胞系和转染人肝型脂肪酸结合蛋白的鼠近端肾小管细胞系进行了体外研究，发现基因转染肝型脂肪酸结合蛋白，在某种程度上，重组肝型脂肪酸结合蛋白的施用显着减弱了血管紧张素II诱导的活性氧的产生以及鼠近端肾小管细胞系中血管紧张素原和单核细胞趋化蛋白-1的表达。这些发现表明，近端肾小管中的肝型脂肪酸结合蛋白可以通过减弱肾内肾素-血管紧张素系统的激活并减少氧化应激和肾小管间质炎症来预防血管紧张素II诱导的SSHT。目前的数据表明，近端小管中的肝型脂肪酸结合蛋白可能是SSHT的新治疗靶标。

BACKGROUND & AIMS: BACKGROUND:In premenopausal women treated for breast cancer, loss of bone mineral density (BMD) follows from menopause induced by chemotherapy or loss of ovarian function biochemically or by surgical oophorectomy. The impact on BMD of surgical oophorectomy plus tamoxifen therapy has not been described. METHODS:In 270 Filipino and Vietnamese premenopausal patients participating in a clinical trial assessing the impact of the timing in the menstrual cycle of adjuvant surgical oophorectomy on breast cancer outcomes, BMD was measured at the lumbar spine and femoral neck before this treatment, and at 6, 12, and 24 months after surgical and tamoxifen therapies. RESULTS:In women with a pretreatment BMD assessment and at least 1 other subsequent BMD assessment, no significant change in femoral neck BMD was observed over the 2-year period (-0.006 g/cm2 , -0.8%, P = .19), whereas in the lumbar spine, BMD fell by 0.045 g/cm2 (4.7%) in the first 12 months (P < .0001) and then began to stabilize. CONCLUSIONS:Surgically induced menopause with tamoxifen treatment is associated with loss of BMD at a rate that lessens over 2 years in the lumbar spine and no significant change of BMD in the femoral neck.

背景与目标：

BACKGROUND & AIMS: :Soil salinity is a major abiotic stress that limits plant growth and productivity. High concentrations of sodium chloride can cause osmotic and ionic effects. This stress minimises a plant's ability to uptake water and minerals, and increases Na+ accumulation in the cytosol, thereby disturbing metabolic processes. Prolonged plant exposure to salt stress can lead to oxidative stress and increased production of reactive oxygen species (ROS). Higher plants developed some strategies to cope with salt stress. Among these, mechanisms involving nitric oxide (NO) and polyamines (PAs) are particularly important. NO is a key signalling molecule that mediates a variety of physiological functions and defence responses against abiotic stresses in plants. Under salinity conditions, NO donors increase growth parameters, reduce Na+ toxicity, maintain ionic homeostasis, stimulate osmolyte accumulation and prevent damages caused by ROS. NO enhances salt tolerance of plants via post-translational protein modifications through S-nitrosylation of thiol groups, nitration of tyrosine residues and modulation of multiple gene expression. Several reviews have reported on the role of polyamines in modulating salt stress plant response and the capacity to enhance PA synthesis upon salt stress exposure, and it is known that NO and PAs interact under salinity. In this review, we focus on the role of NO in plant response to salt stress, paying particular attention to the interaction between NO and PAs.

背景与目标： : 土壤盐分是一种主要的非生物胁迫，限制了植物的生长和生产力。高浓度的氯化钠会引起渗透效应和离子效应。这种压力最大程度地降低了植物吸收水和矿物质的能力，并增加了胞质溶胶中Na的积累，从而干扰了代谢过程。植物长期暴露于盐胁迫会导致氧化应激和活性氧 (ROS) 的产生增加。高等植物开发了一些应对盐胁迫的策略。其中，涉及一氧化氮 (NO) 和多胺 (PAs) 的机制尤为重要。NO是一种关键的信号分子，可介导多种生理功能和针对植物非生物胁迫的防御反应。在盐度条件下，NO供体增加了生长参数，降低了Na毒性，维持了离子稳态，刺激了渗透剂的积累并防止了ROS引起的损害。NO通过巯基的S-亚硝基化，酪氨酸残基的硝化和多种基因表达的调节，通过翻译后蛋白质修饰增强植物的耐盐性。一些评论报道了多胺在调节盐胁迫植物响应中的作用以及在盐胁迫暴露时增强PA合成的能力，并且已知NO和PAs在盐度下相互作用。在这篇综述中，我们着重于NO在植物对盐胁迫的响应中的作用，特别注意NO和PAs之间的相互作用。

BACKGROUND & AIMS: CONTEXT:In the Denosumab and High-Dose Teriparatide Administration (DATA-HD) study, we reported that 15 months of combined high-dose (HD) teriparatide and denosumab increased mean areal bone mineral density (aBMD) at the hip and spine more than combined denosumab and standard-dose (SD) teriparatide. OBJECTIVE:In the current analysis, we compare the individual rates of aBMD response between the treatment groups. DESIGN:Single-site, open-label, randomized controlled trial in which postmenopausal women received either teriparatide 20-μg daily (SD) or 40-μg daily (HD) given months 0 through 9, overlapped with denosumab 60 mg, given months 3 through 15 (15 months' total duration). The proportion of participants in the SD and HD groups experiencing total hip, femoral neck, and lumbar spine aBMD gains of >3%, >6%, and >9% were compared. PARTICIPANTS:Postmenopausal women with osteoporosis completing all study visits (n = 60). MAIN OUTCOME MEASURE(S):aBMD (dual x-ray absorptiometry). RESULTS:At the end of the 15-month treatment period, a higher proportion of women in the HD group had aBMD increases >3% (83% vs. 58%, P = .037) and >6% (45% vs. 19%, P = .034) at the total hip, and >3% at the femoral neck (86% vs. 63%, P = .044). At the lumbar spine, >3% response rates were similar, whereas the >6% and >9% response rates were greater in the HD group (100% vs. 79%, P = .012 and 93% vs. 59%, P = .003, respectively). CONCLUSION:Compared with the SD regimen, more women treated with the HD regimen achieved clinically meaningful and rapid gains in hip and spine aBMD. These results suggest that this approach may provide unique benefits in the treatment of postmenopausal osteoporosis.

背景与目标：

BACKGROUND & AIMS: BACKGROUND:Calcium may be mobilized from the maternal skeleton during pregnancy, which may be influenced by several factors. OBJECTIVE:The objective was to investigate changes in bone mineral status and size during pregnancy and to consider the influences of body weight and calcium intake. DESIGN:Thirty-four British women were studied before pregnancy and 2 wk postpartum (Preg). Eighty-four nonpregnant, nonlactating (NPNL) women were studied over a corresponding time. Bone mineral content (BMC), bone area (BA), areal bone mineral density (aBMD), and BA-adjusted BMC of the whole-body, lumbar spine, radius, and hip were measured by dual-energy X-ray absorptiometry. RESULTS:The Preg group experienced significant decreases in BMC, aBMD, and BA-adjusted BMC at the whole-body, spine, and total hip of between 1% and 4%. Whole-body BMC increased in the NPNL group, and aBMD and BA-adjusted BMC decreased at the spine and hip by 0.5% to 1%. Whole-body BMC decreased in the Preg group by -2.16 +/- 0.46%, equivalent to -2.71 +/- 0.43% relative to the NPNL group (P < or = 0.001). Weight change was a positive predictor of skeletal change at the spine, hip, and radius in both groups. Differences between the Preg and NPNL groups in change in BA-adjusted BMC, after correction for weight change and other influences, were as follows (P < or = 0.01): whole-body, -1.70 +/- 0.25%; spine, -3.03 +/- 0.72%; and total hip, -1.87 +/- 0.60%. Calcium intake was not a significant predictor of skeletal change in either group. CONCLUSIONS:Pregnancy is associated with decreases in whole-body and regional bone mineral status sufficient to make a sizeable contribution to maternal and fetal calcium economy. Calcium intake is not a significant predictor of the skeletal response to pregnancy in well-nourished women.

背景与目标：

BACKGROUND & AIMS: :Added Ce(3+) can partly substitute for Ca(2+) or Mg(2+) and improve photosynthesis under the deficiency of these elements, but very few studies focused on photosynthetic improvement in maize seedlings caused by K(+) deficiency, salt stress, especially a combination of K(+) deficiency and salt stress. In the present study, the effects of Ce(3+) on the photosynthesis of maize seedlings under the three different stresses were investigated. The results showed that added Ce(3+) under various stresses increased the ratios of free water/bound water and of K(+)/Na(+), the pigment contents, the values of Fv/Fm, Y(II), ETR(II), Y(NPQ), Qp, qL, NPQ, and qN of photosystem II (PSII), the values of Y(I) and ETR(I) of photosystem I (PSI) and the expression levels of LhcII cab1 and rbcL, and decreased the values of Y(NO) and Y(NA). This implied that added Ce(3+) depressed ion toxicity, photodamage of PSII, and acceptor side constraints of PSI, and enhanced adjustable energy dissipation, the responses of photochemistry, and carbon assimilation caused by K(+) deficiency, salt stress, and the combination of K(+) deficiency and salt stress. However, Ce(3+) mitigation of photosynthetic inhibition in maize seedlings caused by the combined stresses was greater than that of salt stress, and Ce(3+) mitigation under salt stress was greater than that under K(+) deficiency. In addition, the results also showed that Ce(3+) cannot improve photosynthesis and growth of maize seedlings under K(+) deficiency by substituting for K(+).

背景与目标： : 添加的Ce(3) 可以部分替代Ca(2) 或Mg(2)，并在缺乏这些元素的情况下改善光合作用，但很少有研究关注K () 缺乏，盐胁迫引起的玉米幼苗光合作用的改善。特别是钾 (+) 缺乏和盐胁迫的结合。在本研究中，研究了Ce(3) 对三种不同胁迫下玉米幼苗光合作用的影响。结果表明，在各种应力下添加Ce(3) 增加了自由水/结合水和K ()/Na () 的比率，颜料含量，Fv/Fm，Y(II)，ETR(II)，Y(NPQ)，光系统II (PSII) 的Qp，qL，NPQ和qN，光系统I (PSI) 的Y(I) 和ETR(I) 的值以及LhcII cab1和rbcL的表达水平，并降低了Y的值 (NO) 和Y(NA)。这意味着添加Ce(3) 抑制了离子毒性，PSII的光损伤和PSI的受体侧约束，并增强了可调节的能量耗散，光化学反应以及由K () 缺乏引起的碳同化，盐胁迫，以及钾 (+) 缺乏和盐胁迫的结合。然而，联合胁迫对玉米幼苗光合抑制的Ce(3 +) 缓解大于盐胁迫，盐胁迫下Ce(3 +) 缓解大于钾 (+) 缺乏下Ce(3 +) 缓解。此外，结果还表明，Ce(3) 不能通过替代K () 来改善K () 缺乏下玉米幼苗的光合作用和生长。

BACKGROUND & AIMS: OBJECTIVES:Juglans (J.) regia L. is known to possess many biological properties. In this study, antihemolytic activity of methanol extract of Juglans regia L. flower were investigated. MATERIALS AND METHODS:Antihemolytic activities of Juglans regia L. flowers were evaluated by various in vitro assays. In addition, scavenging of hydrogen peroxide and mineral contents of flowers were determined using atomic absorption spectroscopy. RESULTS:Extract showed good antihemolytic activity against H2O2 and CuOOH induced hemolysis in comparison with control. Extract was capable of scavenging H2O2 in a concentration dependent manner. IC50 for H2O2 scavenging activity was 311±12.8 µg ml-1. The amount of eight elements was determined and was in the order: Mn > Cu > Fe > Zn. CONCLUSIONS:Our study indicate that J. regia flower has remarkable antihemolytic activity, which maybe result of its high phenol and flavonoid contents, especially quercetin.

背景与目标：

BACKGROUND & AIMS: :Adolescent idiopathic scoliosis (AIS) is a pathological entity of unknown etiology. The causes of osteoporosis or osteopenia in AIS remain undetermined. Whether poor bone quality is an etiologic factor remains controversial. To determine the correlation between low bone mineral status and AIS, a review of literature was performed. After a literature search from 1966 to June 2007 (using Medline, EMBASE, Cochrane DSR, ACP Journal Club, DARE, CCTR, CINAHL and hand searches of references) for studies regarding low bone mineral status and AIS, 20 studies meeting the inclusion criteria were reviewed in terms of the appropriateness of valuation technique, the validity of descriptive system, the number and type of respondents, and overall quality of the studies. Nearly all investigations demonstrated that low bone mineral density (BMD) was a generalized phenomenon and a systematic disorder in AIS. The prevalence of AIS with osteoporosis is approximately 20-38%. The follow-up studies indicated that osteopenia in patients with AIS may be a persistent phenomenon. BMD could be affected by the mechanical loading and lower bone mineral mass is always associated with lower bone strength. The spinal architecture associated with the osteopenia may aggravate the spinal deformity. However, with regard to the concave and convex femoral neck BMD values, and the correlation of BMD to scoliosis parameters, the results remain inconsistent. Bracing may not result in permanent loss of bone mineral mass. The effect of the eccentric tension-compression environments on BMD, the correlation of BMD with scoliosis parameters and the effect of bracing on BMD should be investigated further in prospective, randomized and longitudinal follow-up studies.

背景与目标： : 青少年特发性脊柱侧凸 (AIS) 是病因不明的病理实体。AIS中骨质疏松症或骨量减少的原因尚未确定。骨质量差是否是病因仍存在争议。为了确定低骨矿物质状态与AIS之间的相关性，对文献进行了回顾。在1966年2007年6月 (使用Medline，EMBASE，Cochrane DSR，ACP Journal Club，DARE，CCTR，CINAHL和参考文献的手工搜索) 进行有关低骨矿物质状况和AIS的研究之后，对20项符合纳入标准的研究进行了审查。评估技术的适当性，描述系统的有效性，受访者的数量和类型以及研究的整体质量。几乎所有研究都表明，低骨矿物质密度 (BMD) 是AIS的普遍现象和系统疾病。患有骨质疏松症的AIS的患病率约为20-38%。随访研究表明，AIS患者的骨量减少可能是一种持续的现象。BMD可能会受到机械负荷的影响，而较低的骨矿物质质量始终与较低的骨强度有关。与骨质减少相关的脊柱结构可能会加剧脊柱畸形。但是，关于凹凸股骨颈BMD值以及BMD与脊柱侧弯参数的相关性，结果仍然不一致。支撑可能不会导致骨矿物质质量的永久性损失。在前瞻性，随机和纵向随访研究中，应进一步研究偏心拉伸压缩环境对BMD的影响，BMD与脊柱侧弯参数的相关性以及支撑对BMD的影响。

BACKGROUND & AIMS: :For sustainable agriculture in saline soil, extensive exploitation of salt-tolerant plant growth-promoting (PGP) bacteria and other symbiotic bacteria is required. This study was carried out to evaluate the efficiency of native salt-tolerant rice rhizobacteria for plant growth promotion under salt stress. A total of 188 bacteria were screened for assessing salt-tolerant capacity and nine isolates tolerating 12% NaCl (w/v) concentration were selected. Biochemical and molecular identification revealed that the salt-tolerant bacteria belonged to Bacillus sp, Exiguobacterium sp, Enterobacter sp, Lysinibacillus sp, Stenotrophomonas sp, Microbacterium sp, and Achromobacter sp. The increase in NaCl concentration from 2 to 4% decreases the PGP activities such as IAA production, P solubilization, K solubilization, and nitrate reduction. The effects of inoculation of salt-tolerant bacteria on the growth and different physiological properties of rice (Oryza sativa) were studied. It was found that the salinity affected the root and shoot length of the control plants; however, bacterial inoculant were found to effectively promote the growth of paddy under salinity stress. Further, bacterial inoculants substantially enhanced total chlorophyll, proline, total phenol, and oxidative damage such as electrolyte leakage and membrane stability index under salt stress. This study suggests that salt-tolerant PGP bacteria may be used for cultivation of O. sativa in salinized agricultural lands.

背景与目标： : 为了在盐渍土中实现可持续农业，需要广泛开发耐盐植物促生长 (PGP) 细菌和其他共生细菌。本研究旨在评估天然耐盐水稻根瘤菌在盐胁迫下促进植物生长的效率。总共筛选了188种细菌以评估耐盐能力，并选择了9种12% NaCl (w/v) 浓度的菌株。生化和分子鉴定表明，耐盐细菌属于芽孢杆菌属，外杆菌属，肠杆菌属，赖氨酸杆菌属，窄食单胞菌属，微细菌属和无色杆菌属。NaCl浓度从2增加到4% 会降低PGP活性，例如IAA产生，P增溶，K增溶，和硝酸盐还原。研究了接种耐盐细菌对水稻 (Oryza sativa) 生长和不同生理特性的影响。发现盐度影响对照植物的根长和芽长。但是，发现细菌接种剂可以有效地促进盐度胁迫下稻谷的生长。此外，细菌接种剂在盐胁迫下显着增强了总叶绿素，脯氨酸，总酚和氧化损伤，例如电解质泄漏和膜稳定性指数。这项研究表明，耐盐PGP细菌可用于盐碱化农田的水稻种植。

BACKGROUND & AIMS: :The effect of salt stress on nitrogen fixation, in relation to sucrose transport towards nodules and other sink organs and the potential of sucrose breakdown by nodules, was investigated in two lines of Medicago ciliaris. Under salt stress conditions, the two lines showed a decrease of total biomass production, but TNC 1.8 was less affected by salt than TNC 11.9. The chlorophyll content was not changed in TNC 1.8, in contrast to TNC 11.9. Shoot, root, and nodule biomass were also affected in the two lines, but TNC 1.8 exhibited the higher potentialities of biomass production of these organs. Nitrogen fixation also decreased in the two lines, and was more sensitive to salt than growth parameters. TNC 1.8 consistently exhibited the higher values of nitrogen fixation. Unlike nodules, leaves of both lines were well supplied in nutrients with some exceptions. Specifically, the calcium content decreased in the sensitive line leaves, and the nodule magnesium content was not changed in either line. The tolerant line accumulated more sodium in its leaves. The two lines did not show any differences in the nodule sodium content. Sucrose allocation towards nodules was affected by salt in the two lines, but this constraint did not seem to affect the repartition of sucrose between sink organs. Salt stress induced perturbations in nodule sucrolytic activities in the two lines. It inhibited sucrose synthase, but the inhibition was more marked in TNC 11.9; alkaline/neutral activity was not altered in TNC 1.8, whereas it decreased more than half in TNC 11.9. Thus, the relative tolerance of TNC 1.8 to salt stress could be attributed to a better use of these photoassimilates by nodules and a better supply of bacteroids in malate. The hypothesis of a competition for sucrose between nodules and other sink organs under salt stress could not be verified.

背景与目标： : 在两条纤毛紫花苜蓿中研究了盐胁迫对固氮的影响，与蔗糖向结节和其他汇器官的转运以及结节对蔗糖分解的潜力有关。在盐胁迫条件下，两品系的总生物量产量均有所下降，但TNC 1.8受盐的影响小于TNC 11.9。与TNC 1.8相比，TNC 11.9的叶绿素含量没有变化。在这两个品系中，芽，根和根瘤生物量也受到影响，但是TNC 1.8显示出这些器官产生生物量的更高潜力。两品系的固氮作用也有所降低，并且对盐的敏感性高于生长参数。TNC 1.8始终表现出较高的固氮值。与结节不同，这两个品系的叶子都有很好的营养供应，但有一些例外。具体来说，敏感品系叶片中的钙含量降低，而根瘤镁含量在任一品系中均没有变化。耐性品系在其叶片中积累了更多的钠。两条线没有显示结节钠含量的任何差异。蔗糖向结节的分配受到两行盐的影响，但是这种限制似乎并未影响蔗糖在汇器官之间的重新分配。盐胁迫在两行中引起根瘤蔗糖活性的扰动。它抑制了蔗糖合酶，但在TNC 11.9中抑制作用更为明显; 在TNC 1.8中，碱性/中性活性没有改变，而在TNC 11.9中，碱性/中性活性下降了一半以上。因此，TNC 1.8对盐胁迫的相对耐受性可归因于结节更好地利用这些光同化物和苹果酸中更好地供应类细菌。无法验证在盐胁迫下结核和其他汇器官之间竞争蔗糖的假设。

BACKGROUND & AIMS: :Salinity is one of the most important abiotic factors in various natural habitats of microbes. Cyanobacteria are the most widely distributed family of photosynthetic microorganisms in environments with fluctuating salinity. In response to salt stress, many cyanobacteria de novo synthesize compatible solutes to maintain osmotic balance in the cell. However, the regulation of intracellular accumulation of these compounds is still not well understood. The freshwater cyanobacterium Synechococcus elongatus PCC 7942 (Syn7942) exclusively accumulates sucrose as a compatible solute upon salt stress and is thus an ideal model microorganism for studying the metabolism of compatible solute dynamics. Here, we focused on elucidating the regulatory mechanisms involved in salt-induced sucrose accumulation in Syn7942. Using a series of physiological and biochemical experiments, we showed that the ionic effect of salt stress plays an important role in inducing sucrose synthesis, whereby elevated ion concentration directly activates the sucrose-synthesizing enzyme sucrose-phosphate synthase and simultaneously inhibits the sucrose-degrading enzyme invertase, resulting in a rapid sucrose accumulation. Thus, we propose a novel mechanism for cyanobacterial adaption to salt stress and fluctuating salinity, i.e., the ion-induced synergistic modulation of the enzymes synthesizing and degrading compatible solutes. These findings greatly enhance our current understanding of microbial adaptation to salt.IMPORTANCE Most microbes de novo synthesize compatible solutes for adaptation to salt stress or fluctuating salinity environments. However, to date, one of the core questions involved in these physiological processes, i.e., the regulation of salt-induced compatible solute biosynthesis, is still not well understood. Here, this issue was systematically investigated by employing the model freshwater cyanobacterium Synechococcus elongatus PCC 7942. A novel mechanism for cyanobacterial adaption to salt stress and fluctuating salinity, i.e., the ion-induced synergistic modulation of key synthesizing and degrading enzymes of compatible solutes, is proposed. Because the ion-induced activation/inhibition of enzymes is a fast and efficient process, it may represent a common strategy of microbes for adaptation to environments with fluctuating salinity.

背景与目标： : 盐度是微生物各种自然栖息地中最重要的非生物因子之一。蓝细菌是盐度波动环境中分布最广泛的光合微生物家族。为了应对盐胁迫，许多蓝细菌从头合成了相容的溶质，以维持细胞内的渗透平衡。然而，对这些化合物的细胞内积累的调节仍然没有很好的理解。淡水蓝细菌Synechococcus elongatus PCC 7942 (Syn7942) 在盐胁迫下专门积累蔗糖作为相容溶质，因此是研究相容溶质动力学代谢的理想模型微生物。在这里，我们重点阐明了syn7942中盐诱导蔗糖积累的调控机制。通过一系列生理生化实验表明，盐胁迫的离子效应在诱导蔗糖合成中起着重要作用，离子浓度升高直接激活蔗糖合成酶蔗糖-磷酸合成酶，同时抑制蔗糖降解酶转化酶，导致蔗糖快速积累。因此，我们提出了一种新的机制，用于蓝藻适应盐胁迫和盐度波动，即离子诱导的酶合成和降解相容溶质的协同调节。这些发现极大地增强了我们目前对微生物适应盐的理解。重要性大多数微生物从头合成相容的溶质，以适应盐胁迫或盐度波动的环境。然而，迄今为止，这些生理过程中涉及的核心问题之一，即盐诱导的相容性溶质生物合成的调节，仍然没有得到很好的理解。在此，通过使用模型淡水蓝细菌Synechococcus elongatus PCC 7942系统地研究了此问题。提出了一种新的蓝藻适应盐胁迫和盐度波动的机制，即离子诱导的相容溶质关键合成和降解酶的协同调节。由于离子诱导的酶激活/抑制是一个快速有效的过程，因此它可能代表了微生物适应盐度波动环境的通用策略。

BACKGROUND & AIMS: :After prolonged treatment (76.4+/-10 and 70.1+/-12.3 months, respectively) (mean+/-SE) with testosterone enanthate (250 mg i.m. every 3 weeks), bone mineral density (BMD) and bone metabolism were evaluated in 12 patients (aged 29.3+/-1.4 yr) affected by idiopathic hypogonadotropic hypogonadism (IHH), in 8 patients (29.6+/-2.6 yr) affected by Klinefelter's syndrome (KS), and in 10 healthy men (30.6+/-1.7 yr) matched according to age and BMI. Spinal BMD in IHH was significantly lower than in controls (0.804+/-0.04 vs 1.080+/-0.01 g/cm2; p<0.001), while there was no difference in neck BMD (0.850+/-0.01 vs 0.948+/-0.02 g/cm2). Neither spinal (0.978+/-0.05 g/cm2) nor neck (0.892+/-0.03 g/cm2) BMD in KS were significantly different from controls. Six IHH and one KS subjects were osteoporotic, while 6 IHH and 2 KS subjects were osteopenic. A significant inverse correlation was found between spinal BMD and age at the treatment onset in IHH (r=-0.726, p=0.007). In IHH there were significant increases in bone formation (alkaline phosphatase=318.3+/-33.9 vs 205.4+/-20.0 IU/l; osteocalcin=13.44+/-1.44 vs 8.57+/-0.94 ng/ml; p<0.05) and in bone resorption (urinary cross-linked N-telopeptides of type I collagen=149.1+/-32.3 vs 47.07+/-8.4 nmol bone collagen equivalents/mmol creatinine; p<0.05) compared to controls, while such differences were not present in KS. Our results outline the importance of BMD evaluation in all hypogonadal males. Nevertheless, bone loss is a minor characteristic of KS, while it is a distinctive feature of IHH. Therefore, early diagnosis and age-related replacement therapy coupled with a specific treatment for osteoporosis could be useful in preventing future severe bone loss and associated skeletal morbidity.

背景与目标： : 经过长时间的治疗 (分别为76.4/-10和70.1/-12.3个月) (平均/-SE)，庚酸睾酮 (每3周250 mg i.m.)，对12例 (年龄29.3 +/-1.4岁) 的特发性低促性腺激素性性腺功能减退症 (IHH) 患者和8例 (29.6 +/-2.6岁) 的Klinefelter综合征 (KS) 患者进行了骨矿物质密度 (BMD) 和骨代谢评估，10名健康男性 (30.6 +/-1.7岁) 根据年龄和BMI进行匹配。IHH的脊柱BMD明显低于对照组 (0.804 +/-0.04 vs 1.080 +/-0.01g/cm2; p<0.001)，而颈部BMD无差异 (0.850 +/-0.01 vs 0.948 +/-0.02g/cm2)。KS中的脊柱 (0.978/-0.05g/cm2) 和颈部 (0.892/-0.03g/cm2) BMD均与对照组无显着差异。6名IHH和1名KS受试者为骨质疏松，而6名IHH和2名KS受试者为骨质疏松。在IHH中，脊柱BMD与治疗开始时的年龄之间存在显着的负相关 (r =-0.726，p = 0.007)。在IHH中，骨形成显着增加 (碱性磷酸酶 = 318.3/-33.9 vs 205.4/-20.0 IU/l; 骨钙素 = 13.44/-1.44 vs 8.57/-0.94 ng/ml; 与对照组相比，p<0.05) 和骨吸收 (I型胶原的尿交联N-端肽 = 149.1 +/-32.3 vs 47.07 +/-8.4 nmol骨胶原当量/mmol肌酐; p<0.05)，而KS中不存在这种差异。我们的结果概述了BMD评估在所有性腺功能减退男性中的重要性。然而，骨丢失是KS的次要特征，而它是IHH的显着特征。因此，早期诊断和与年龄相关的替代疗法以及针对骨质疏松症的特定治疗可能有助于预防未来的严重骨质流失和相关的骨骼发病率。

BACKGROUND & AIMS: :Human milk provides newborns with several physiologically important proteins not found in cow's milk, including bile salt-stimulated lipase (BSSL) that compensates for the reduced lipolytic capability of the newborn intestine. We analyzed the milk of two ethnically distinct groups of women in northern Nigeria and Nepal. The milk of the Nepalese women (n = 36) contained slightly more BSSL activity (mean, 38.8 units/mL) than that of Fulani (n = 48; mean, 30.3 units/mL) and Kanuri (n = 90; mean 27.6 units/mL) women in Nigeria. There was also a weak positive correlation between the BSSL content of the milk and the body mass index (BMI) of the lactating women. The BSSL activity declined with the length of lactation for both well-nourished and undernourished women. The presence of a heat-stable inhibitor of BSSL in cow's milk was also demonstrated. This finding, along with the decrease in BSSL activity postgestation, could be of significance to populations such as the Fulani of the western Sahel who supplement the diets of their infants with unpasteurized cow's milk.

背景与目标： : 人乳为新生儿提供了几种在牛奶中找不到的生理重要蛋白质，包括胆汁盐刺激的脂肪酶 (BSSL)，可补偿新生儿肠道脂分解能力的降低。我们分析了尼日利亚北部和尼泊尔两个不同种族的妇女群体的牛奶。尼泊尔妇女 (n = 36) 的牛奶含有的BSSL活性 (平均38.8单位/mL) 略高于富拉尼 (n = 48; 平均30.3单位/mL) 和卡努里 (n = 90; 平均27.6单位/mL) 尼日利亚妇女。牛奶中的BSSL含量与哺乳期妇女的体重指数 (BMI) 之间也呈弱正相关。营养丰富和营养不足的妇女的BSSL活性随着泌乳时间的延长而下降。还证明了牛奶中BSSL的热稳定抑制剂的存在。这一发现，以及妊娠后BSSL活性的降低，可能对诸如西萨赫勒地区的富拉尼人等人群具有重要意义，他们用未经巴氏消毒的牛奶补充婴儿的饮食。