持续质量改进对老年腹膜透析患者钙磷代谢紊乱的作用

目的:探讨应用持续质量改进(CQI)的方法纠正老年腹膜透析患者钙磷代谢紊乱的效果。方法:运用PDCA四步法,即设计、实施、检验和应用,设计并实施改善老年腹膜透析患者钙磷代谢紊乱的治疗措施。结果:45例腹膜透析时间>3个月的老年患者参与了此项研究。经9个月CQI,各种钙磷代谢紊乱总发生率由82.22%降至42.22%(P<0.05)。其中高钙血症组血钙由(2.71±0.25)mmol/L降至(2.52±0.31)mmol/L(P<0.05),低钙血症组血钙由(1.78±0.42)mmol/L升至(2.11±0.24)mmol/L(P<0.05),血磷水平由(2.13±0.62)mmol/L降至(1.67±0.53)mmol/L(P<0.05),钙磷乘积由(80.22±16.61)mg2/dl2降至(54.58±15.93)mg2/dl2(P<0.05),继发性甲状旁腺功能亢进患者的血清全段甲状旁腺素(iPTH)由(488.12±227.31)pg/ml降至(290.3±171.15)pg/ml(P<0.01),血清碱性磷酸酶水平由(108.75±35.31)U/L降至(88.75±38.14)U/L(P<0.05)。有残肾功能较无残肾功能组,虽KT/V差异不大,在CQI后纠正高磷血症、高钙血症、甲状旁腺功能亢进上差异均有统计学意义(P<0.05)。结论:持续质量改进措施显著改善了老年腹膜透析患者的钙磷代谢紊乱。     

A murine model of thoracic aortic aneurysms

BACKGROUND: The mechanisms of thoracic aortic aneurysm (TAA) formation are poorly understood, mainly due to the lack of a useful and reproducible model. Accordingly, the goal of this study was to test the hypothesis that abluminal calcium chloride (CaCl(2)) application could create TAAs in the mouse. MATERIALS AND METHODS: Adult 129/SvE mice (n = 8) were anesthetized and their thoracic aortas exposed via left thoracotomy. CaCl(2) (0.5M) was applied to the distal descending thoracic aorta for 15 min followed by chest closure. At 4 weeks, the perfusion-fixed aorta was harvested from the root to the renal arteries. Diameter measurements were made using confocal microscopy, and wall thickness was measured from hematoxylin and eosin-stained sections. RESULTS: The control (n = 15) distal descending thoracic aortic diameter was 0.60 +/- 0.04 mm and increased by 25% (0.76 +/- 0.06 mm, P < 0.05) following CaCl(2) treatment. Control aortic wall thickness was 48 +/- 9 mum and decreased by 47% in corresponding CaCl(2)-exposed segments (25 +/- 8 mum, P < 0.05). The diameter and wall thickness of the ascending aorta (used as an internal control) were not significantly different between groups. Picrosirius red staining of the TAA showed adventitial collagen breakdown and disruption of lamellar organization. CONCLUSIONS: We conclude that abluminal application of CaCl(2) to the thoracic aorta reliably produces dilation, wall-thinning, and disruption of mural architecture, the hallmark signs of aneurysm formation. To our knowledge, these findings describe for the first time the generation of a reproducible model of isolated TAA formation in a murine system.     

Rodent Osteoblastic Cells Express Voltage-Sensitive Calcium Channels Lacking a γ Subunit

Voltage-sensitive calcium channels (VSCC) open in response to external stimuli, including calcitropic hormones, that alter plasma membrane calcium (Ca²⁺) permeability. Ca²⁺ that enters the cell through these channels serves a second messenger function, eliciting cellular responses that include secretion and changes in gene expression. In osteoblasts, VSCCs serve as key regulators of Ca²⁺ permeability and are a major class of calcitropic hormone-sensitive Ca²⁺ channels present in the plasma membrane. The members of the VSCC family exist as a complex of polypeptide subunits that are comprised of a pore-forming ₁ subunit, an intracellular subunit, a dimer of disulfide-linked ₂ and subunits, and in some tissues, a subunit. Previous studies in our laboratory have shown that the major functional ₁ subunit present in osteoblasts is the _1C (Ca_V1.2). To determine the complement of auxiliary subunits present in rodent osteoblastic cells, we employed RT-PCR using a battery of subunit specific primers and appropriate tissue controls. Immunohistochemistry also was performed, using available subunit specific antibodies, to measure protein expression and localization. Cell types examined included MC3T3-E1 at various stages of differentiation, ROS 17/2.8 osteosarcoma, and primary cultures of rat calvarial osteoblasts. The results indicate that all cells expressed multiple subunit classes and ₂ dimers, but no subunits, regardless of differentiation state. We propose a structure for the functional osteoblast VSCC that consists of ₁, , ₂ subunits and is devoid of a subunit.     

钠钾镁钙葡萄糖注射液术中输注对患者肝肾功能、血电解质、血糖、血乳酸及凝血功能的影响

目的 评估钠钾镁钙葡萄糖注射液（sodium potassium magnesium calcium and glucose,SPMCG）术中输注对患者肝肾功能、血电解质、血糖、血乳酸及凝血功能的影响.方法 择期拟在全身麻醉下行普外科或骨科手术的患者80例,美国麻醉医师协会（ASA）分级Ⅰ级～Ⅱ级,采用随机数字表法分为实验组和对照组,每组40例.实验组给予SPMCG,对照组给予乳酸钠林格注射液.两组均以15 ml·kg-1·h-1的速度输注500 ml液体后行麻醉诱导,诱导后以10 ml·kg 1·h-1的速度维持输液2h,之后以8 ml·kg-1h-1的速度维持至手术结束.输液前后测定患者的肝肾功能、血电解质以及凝血功能,并监测输液前即刻、诱导前即刻、诱导后1、2h和输液结束时即刻各时间点的血乳酸和血糖值.结果 两组患者输注相应液体后,丙氨酸氨基转移酶（alanine aminotransferase,ALT）、天门冬氨酸氨基转移酶（aspartateaminotransferase,AST）、白蛋白（albumin,ALB）、总胆红素（total bilirubin,TBIL）、血尿素氮（blood urea nitrogen,BUN）和血肌酐（serum creatinine,Cr）与输液前比较差异无统计学意义,组间比较差异无统计学意义.电解质方面,输液后2组Na＋、K＋、Cl-、Ca2＋的浓度差异无统计学意义,但实验组输液后Mg2浓度较对照组高[（0.48±0.21） mmol/L vs（0.71±0.31） mmol/L（P＜0.05）].手术过程中2组患者血糖均逐渐上升,术后又下降至输液前水平.两种液体输注后,凝血酶原时间（prothrombin time,PT）和部分凝血活酶时间（activated partial thromboplastin time,APTT）无显著变化.结论 在术中输注SPMCG,对患者肝肾功能、血电解质、血糖、血乳酸及凝血功能无明显不良影响,并且相对于乳酸钠林格注射液,SPMCG能更好地维持血镁水平.     

Engineered CaM2 modulates nuclear calcium oscillation and enhances legume root nodule symbiosis

The key physiological event essential to the establishment of nitrogen-fixing bacteria and phosphate-delivering arbuscular mycorrhizal symbioses is the induction of nuclear calcium oscillations that are required for endosymbioses. These regular fluctuations in nucleoplasmic calcium concentrations are generated by ion channels and a pump located at the nuclear envelope, including the CYCLIC NUCLEOTIDE GATED CHANNEL 15 (CNGC15). However, how the CNGC15s are regulated in planta to sustain a calcium oscillatory mechanism remains unknown. Here, we demonstrate that the CNGC15s are regulated by the calcium-bound form of the calmodulin 2 (holo-CaM2), which, upon release of calcium, provides negative feedback to close the CNGC15s. Combining structural and evolutionary analyses of CaM residues with bioinformatic analysis, we engineered a holo-CaM2 with an increased affinity for CNGC15s. In planta, the expression of the engineered holo-CaM2 accelerates the calcium oscillation frequency, early endosymbioses signaling and is sufficient to sustain over time an enhanced root nodule symbiosis but not an increased arbuscular mycorrhization. Together, these results reveal that holo-CaM2 is a component of endosymbiosis signaling required to modulate CNGC15s activity and the downstream root nodule symbiosis pathway.

Nutrient acquisition is fundamental to life. Plants have evolved strategies to overcome soil phosphate limitation and gain access to atmospheric dinitrogen by developing beneficial associations with arbuscular mycorrhizal (AM) fungi and nitrogen-fixing bacteria, respectively. Unlike other crops, the vast majority of legumes have mastered associations with both endosymbionts, positioning them as key crops to develop sustainable agricultural practices in both developed and developing countries (1).The entry of nitrogen-fixing bacteria, known as rhizobia, and AM fungi into legume roots is initiated by the recognition of the endosymbiont. Host plants have plasma-membrane receptor-like kinases (2–6) that recognize rhizobial elicitors, lipochitooligosaccharides (LCOs), also known as Nod factors (7), and mycorrhizal factors composed of derivatives of LCOs and shorter chain chitooligosaccharides (8, 9). Although rhizobial and AM elicitors are recognized by different complexes of receptor-like kinases (10, 11), both symbionts require the activation of calcium oscillations in root epidermal nuclei (9, 12, 13) to set off the endosymbiosis program. In the model legume Medicago truncatula, two types of nuclear envelope localized ion channels are required to generate the calcium oscillation; the DOESN’T MAKE INFECTIONS1 (DMI1) channel and paralogs of CYCLIC NUCLEOTIDE GATED CHANNEL 15 (CNGC15) (14), and the calcium pump, MCA8 (15). Similar to the animal CNGCs, plant CNGCs are tetrameric ion channels that can include different CNGC units (16, 17). In M. truncatula, CNGC15a, CNGC15b, and CNGC15c are all involved in nuclear calcium oscillation in the root epidermis, nodulation, and arbuscular mycorrhization, suggesting that the three units could assemble into a heterocomplex at the nuclear envelope (14). However, how CNGC15s are regulated in planta to sustain a calcium oscillatory mechanism remains unknown.In this study, we demonstrate that CNGC15s are regulated by the calcium-bound form of the calmodulin 2 (holo-CaM2) in planta, which shapes the oscillatory pattern of nucleoplasmic calcium concentration by providing negative feedback on CNGC15s to cause its closure. By engineering CaM2 to generate CaM2^R91A, which specifically increased holo-CaM2 binding affinity to each CNGC15 unit, we accelerated closure of CNGC15s and increased the calcium oscillation frequency. We further show that accelerating the calcium oscillation frequency was sufficient to accelerate the early endosymbiosis signaling and that the expression of CaM2^R91A resulted in an enhanced root nodule symbiosis but not enhanced AM colonization. Our data reveal differential regulation of rhizobia and AM endosymbioses by CaM2^R91A and suggest that modulating calcium signaling can be used as a strategy to positively impact symbiosis with nitrogen-fixing bacteria.     

Focus超声刀在甲状腺手术中甲状旁腺的功能保护及对术后血钙水平的影响

目的探讨Focus超声刀在甲状腺手术中的应用及其对甲状旁腺的功能保护作用,以及围手术期患者血钙水平的变化。方法选取本院2010年5月至2011年5月实施的甲状腺手术226例,采用传统手术方式,设为对照组;选取2011年6月至2012年6月实施的甲状腺手术250例,应用Focus超声刀实施手术,设为观察组。比较两组患者的手术效果与效率,术前、术后3天血清甲状旁腺素、血钙及血磷水平,观察甲状旁腺功能损伤患者治疗及随访结果。结果两组患者手术过程均比较顺利,无术中及住院期间死亡病例,术后病理诊断均与临床诊断一致;观察组患者手术时间、术中出血量、术后引流量、平均住院时间均少于（或短于）对照组（P〈0．01或P〈O．05）;观察组低钙血症、血钙下降的发生率均低于对照组（P〈0．01或P〈0．05）。术前两组患者血清甲状旁腺素、血钙、血磷比较,差异均无统计学意义（P〉0．05）;术后,对照组血清甲状旁腺素、血钙水平降低,血磷水平升高（P〈0．01或P〈0．05）,表明对照组患者甲状旁腺功能损伤;观察组患者手术前后甲状旁腺功能比较稳定。术后3月内,所有甲状旁腺功能损伤患者均恢复至正常范围,无永久性甲状旁腺功能减退的发生。结论Focus超声刀在甲状腺手术中对甲状旁腺具有较好的保护作用,术中组织分离、止血效果确切,损伤较小．术后患者血清甲状旁腺功能指标稳定,恢复较快,是目前比较优化的一种手术措施。     

Estrogen treatment of spinal cord injury attenuates calpain activation and apoptosis

Spinal cord injury (SCI) is a devastating neurologic injury, and currently, the only recommended pharmacotherapy is high-dose methylprednisolone, which has limited efficacy. Estrogen is a multi-active steroid with anti-oxidant and anti-apoptotic effects. Estrogen may modulate intracellular Ca2+ and prevent inflammation. For this study, male rats were divided into three groups. Sham-group animals received a laminectomy at T12. Injured rats received both laminectomy and 40 gram centimeter force SCI. Estrogen-group rats received 4 mg/kg 17beta-estradiol (estrogen) at 15 min and 24 hr post-injury, and vehicle-group rats received equal volumes of dimethyl sulfoxide. Animals were sacrificed at 48 hr post-injury, and 1-cm segments of the lesion, rostral penumbra, and caudal penumbra were excised. The degradation of 68 kD neurofilament protein (NFP) and estrogen receptors (ER) was examined by Western blot analysis. Protein levels of calpain and the activities of calpain and caspase-3 were also examined. Levels of cytochrome c were determined in both cytosolic and mitochondrial fractions. Cell death with DNA fragmentation was examined using the TUNEL assay. At the lesion, samples from both vehicle and estrogen treated animals showed increased levels of 68 kD NFP degradation, calpain content, calpain activity, cytochrome c release, and degradation of ERalpha and ERbeta, as compared to sham. In the caudal penumbra, estrogen treatment significantly attenuated 68 kD NFP degradation, calpain content, calpain activity, levels of cytosolic cytochrome c, and ERbeta degradation. At the lesion, vehicle-treated animals displayed more TUNEL+ cells, and estrogen treatment significantly attenuated this cell death marker. We conclude that estrogen may inhibit cell death in SCI through calpain inhibition.     

Mitochondrial ligand inhibits store-operated calcium influx and COX-2 production in human microglia

We used calcium sensitive fluorescence microscopy to investigate the actions of PK11195, a ligand for the mitochondrial peripheral benzodiazepine receptor (PBR), to modulate Ca2+ influx through store-operated channels (SOC) in human microglia. PK11195 effectively blocked SOC-mediated Ca2+ influx induced by platelet-activating factor (PAF) in a dose-dependent manner (IC50 of 9 microM). A prolonged SOC-mediated Ca2+ entry was also induced using the sarcoplasmic endoreticulum Ca2+-ATPase (SERCA) inhibitor cyclopiazonic acid (CPA) to deplete intracellular endoplasmic reticulum (ER) stores; a single concentration of PK11195 (at 20 microM) reduced SOC-mediated Ca2+ influx by 78%. RT-PCR and immunocytochemical analysis results showed PK11195 also inhibited the expression and production of cyclooxygenase-2 (COX-2) triggered by PAF stimulation. These results suggest that activation of the PBR in mitochondria is linked to reduced entry of Ca2+ through plasmalemmal SOC and subsequent modulation of cellular functions in human microglia.     

Neurotransmitters involved in fast excitatory neurotransmission directly activate enteric glial cells

Background The intimate association between glial cells and neurons within the enteric nervous system has confounded careful examination of the direct responsiveness of enteric glia to different neuroligands. Therefore, we aimed to investigate whether neurotransmitters known to elicit fast excitatory potentials in enteric nerves also activate enteric glia directly. Methods We studied the effect of acetylcholine (ACh), serotonin (5‐HT), and adenosine triphosphate (ATP) on intracellular Ca²⁺ signaling using aequorin‐expressing and Fluo‐4 AM‐loaded CRL‐2690 rat and human enteric glial cell cultures devoid of neurons. The influence of these neurotransmitters on the proliferation of glia was measured and their effect on the expression of c‐Fos as well as glial fibrillary acidic protein (GFAP), Sox10, and S100 was examined by immunohistochemistry and quantitative RT‐PCR. Key Results Apart from ATP, also ACh and 5‐HT induced a dose‐dependent increase in intracellular Ca²⁺ concentration in CRL‐2690 cells. Similarly, these neurotransmitters also evoked Ca²⁺ transients in human primary enteric glial cells obtained from mucosal biopsies. In contrast with ATP, stimulation with ACh and 5‐HT induced early gene expression in CRL‐2690 cells. The proliferation of enteric glia and their expression of GFAP, Sox10, and S100 were not affected following stimulation with these neurotransmitters. Conclusions & Inferences We provide evidence that enteric glial cells respond to fast excitatory neurotransmitters by changes in intracellular Ca²⁺. On the basis of our experimental in vitro setting, we show that enteric glia are not only directly responsive to purinergic but also to serotonergic and cholinergic signaling mechanisms.