Spectrophotometric Determination of Irrigant Extrusion Using Passive Ultrasonic Irrigation,EndoActivator, or Syringe Irrigation

Introduction

Sodium hypochlorite (NaOCl) irrigation is critical to endodontic success, and several new methods have been developed to improve irrigation efficacy (eg, passive ultrasonic irrigation [PUI] and EndoActivator [EA]). Using a novel spectrophotometric method, this study evaluated NaOCl irrigant extrusion during canal irrigation.

Methods

One hundred fourteen single-rooted extracted teeth were decoronated to leave 15 mm of the root length for each tooth. Cleaning and shaping of the teeth were completed using standardized hand and rotary instrumentation to an apical file size #40/0.04 taper. Roots were sealed (not apex), and 54 straight roots (n = 18/group) and 60 curved roots (>20° curvature, n = 20/group) were included. Teeth were irrigated with 5.25% NaOCl by 1 of 3 methods: passive irrigation with needle, PUI, or EA irrigation. Extrusion of NaOCl was evaluated using a pH indicator and a spectrophotometer. Standard curves were prepared with known amounts of irrigant to quantify amounts in unknown samples.

Results

Irrigant extrusion was minimal with all methods, with most teeth showing no NaOCl extrusion in straight or curved roots. Minor NaOCl extrusion (1–3 μL) in straight roots or curved roots occurred in 10%–11% of teeth in all 3 irrigant methods. Two teeth in both the syringe irrigation and the EA group extruded 3–10 μL of NaOCl.

Conclusions

The spectrophotometric method used in this study proved to be very sensitive while providing quantification of the irrigant levels extruded. Using the PUI or EA tip to within 1 mm of the working length appears to be fairly safe, but apical anatomy can vary in teeth to allow extrusion of irrigant.     

Purple urine bag syndrome in nursing homes: Ten elderly case reports and a literature review

Purple urine bag syndrome (PUBS) is a rare occurrence, in which the patient has a purple-colored urine bag following urinary catheterization for hours to days. Most of authors believe it is a mixture of indigo (blue) and indirubin (red) that becomes purple. Previous study showed that PUBS occurred predominantly in chronically catheterized, constipated women. We collected 10 elderly patients with PUBS in two nursing homes. The first two cases were identified by chart review in 1987 and 2003, and then later eight cases (42.1%) were collected among 19 urinary catheterized elderly in the period between January 2007 and June 2007. In the present report, PUBS probably can occur in any patients with the right elements, namely urinary tract infection (UTI) with bacteria possessing these enzymes, diet with enough tryptophan, and being catheterized. Associations with bed-bound state, Alzheimer’s, or dementia from other causes are reflections of the state of such patients who are at higher risk for UTI, and hence PUBS occurred. Although we presented PUBS as a harmless problem, prevention and control of the nosocomial catheter-associated UTIs (CAUTIs) has become very important in the new patient-centered medical era. Thus, we should decrease the duration of catheterization, improve catheter care, and deploy technological advances designed for prevention, especially in the elderly cared for in nursing homes.     

紫山药营养成分分析研究

<正>山药,别名薯蓣,属薯蓣科(Dioscoreaceae)山药属(DioscoreaL.),是一年生或多年生缠绕性藤本植物,能形成肥大的地下肉质块茎供为食用或药用。有些山药品种是我国重要的出口特产蔬菜之一[1-3]。我国是山药重要原产地和驯化中     

美国紫皮书制度研究与构建我国“生物制品已上市产品目录集”必要性及可行性探讨

目的：对美国FDA紫皮书制度进行研究，结合我国生物制品监管现状与发展，探讨构建我国"生物制品已上市产品目录集"的必要性和可行性。方法：文献研究和对比研究法。结果：对美国紫皮书的内容和作用、美国紫皮书的制度支持及其关键要素进行了研究，在此基础上分析我国"生物制品已上市产品目录集"构建的必要性和可行性。结论：我国现阶段构建"生物制品已上市产品目录集"已具备一定的实施基础，具有可行性和必要性。     

紫甘薯花青素的稳定性及抗氧化性研究

目的探明紫甘薯花青素的稳定性和抗氧化性,为紫甘薯花青素在食品中的加工利用提供理论依据。方法采用HPLC和LC-MSn对ZA1紫甘薯花青素成分进行了分析。比较花青素在室内自然光,紫外光,沸水浴高压灭菌和不同pH值条件下的稳定性。研究了其清除超氧阴离子自由基、羟基自由基和DPPH.自由基等抗氧化性能力。结果紫甘薯花青素成分包括有矢车菊素、飞燕草素、锦葵色素、牵牛花色素和甲基花青素。自然光和紫外光照对花青素稳定性影响较小,高温对花青素稳定性影响较大。pH值对花青素稳定性影响非常大,低pH有利于花青素保留。pH为7.0时,花青素具备较好的清除超氧阴离子、羟基自由基和DPPH.自由基能力。结论紫甘薯花青素稳定性受光照、温度、pH值影响。紫甘薯花青素具有较强的抗氧化能力。     

Experimental evidence for a link among cupredoxins: red, blue, and purple copper transformations in nitrous oxide reductase

The cupredoxin fold is an important motif in numerous proteins that are central to several critical cellular processes ranging from aerobic and anaerobic respiration to catalysis and iron homeostasis. Three types of copper sites have been found to date within cupredoxin folds: blue type 1 (T1) copper, red type 2 (T2) copper, and purple Cu(A). Although as much as 90% sequence difference has been observed among some members of this superfamily of proteins that span several kingdoms, sequence alignment and phylogenic trees strongly suggest an evolutionary link and common ancestry. However, experimental evidence for such a link has been lacking. We report herein the observation of pH-dependent transformation between blue T1 copper, red T2 copper, and the native purple Cu(A) centers of nitrous oxide reductase (N2OR) from Paracoccus denitrificans. The blue and red copper centers form initially before they are transformed into purple Cu(A) center. This transformation process is pH-dependent, with lower pH resulting in fewer trapped T1 and T2 coppers and faster transition to purple Cu(A). These observations suggest that the purple Cu(A) site contains the essential elements of T1 and T2 copper centers and that the Cu(A) center is preferentially formed at low pH. Therefore, this work provides an underlying link between the various cupredoxin copper sites and possible experimental evidence in vitro for the evolutionary relationship between the cupredoxin proteins. The findings also lend physiological relevance to cupredoxin site biosynthesis.     

Mitochondria and chloroplasts as the original sites of melatonin synthesis: a hypothesis related to melatonin's primary function and evolution in eukaryotes

Mitochondria and chloroplasts are major sources of free radical generation in living organisms. Because of this, these organelles require strong protection from free radicals and associated oxidative stress. Melatonin is a potent free radical scavenger and antioxidant. It meets the criteria as a mitochondrial and chloroplast antioxidant. Evidence has emerged to show that both mitochondria and chloroplasts may have the capacity to synthesize and metabolize melatonin. The activity of arylalkylamine N‐acetyltransferase (AANAT), the reported rate‐limiting enzyme in melatonin synthesis, has been identified in mitochondria, and high levels of melatonin have also been found in this organelle. From an evolutionary point of view, the precursor of mitochondria probably is the purple nonsulfur bacterium, particularly, Rhodospirillum rubrum, and chloroplasts are probably the descendents of cyanobacteria. These bacterial species were endosymbionts of host proto‐eukaryotes and gradually transformed into cellular organelles, that is, mitochondria and chloroplasts, respectively, thereby giving rise to eukaryotic cells. Of special importance, both purple nonsulfur bacteria (R. rubrum) and cyanobacteria synthesize melatonin. The enzyme activities required for melatonin synthesis have also been detected in these primitive species. It is our hypothesis that mitochondria and chloroplasts are the original sites of melatonin synthesis in the early stage of endosymbiotic organisms; this synthetic capacity was carried into host eukaryotes by the above‐mentioned bacteria. Moreover, their melatonin biosynthetic capacities have been preserved during evolution. In most, if not in all cells, mitochondria and chloroplasts may continue to be the primary sites of melatonin generation. Melatonin production in other cellular compartments may have derived from mitochondria and chloroplasts. On the basis of this hypothesis, it is also possible to explain why plants typically have higher melatonin levels than do animals. In plants, both chloroplasts and mitochondria likely synthesize melatonin, while animal cells contain only mitochondria. The high levels of melatonin produced by mitochondria and chloroplasts are used to protect these important cellular organelles against oxidative stress and preserve their physiological functions. The superior beneficial effects of melatonin in both mitochondria and chloroplasts have been frequently reported.     

小儿哮咳症见气池青紫与免疫球蛋白的关系

目的观察小儿哮咳症见"气池"青紫与免疫球蛋白(IgG、IgA、IgM)关系的临床研究,探寻小儿哮咳发病的影响因素,为预防、治疗小儿哮咳提供依据,"气池"变化的观察为儿科望诊新增添的内容。方法收集小儿病例资料90例,选择症见"气池"青紫的哮咳患儿30例为观察组、单纯哮咳而未见"气池"青紫患儿30例为对照A组及健康体检小儿30例为对照B组,检测其免疫球蛋白(IgG、IgA、IgM)指标,进行观察、研究、总结。结果症见"气池"青紫哮咳患儿的IgG、IgA、IgM水平较单纯哮咳而未见"气池"青紫患儿及健康体检小儿均有不同程度降低,并且以IgA、IgM降低为主;少数患儿存在免疫球蛋白IgG、IgA、IgM在正常范围内偏高的现象。结论免疫力低下是症见"气池"青紫哮咳患儿反复发作的病因之一,故对临床症见"气池"青紫的哮咳患儿应常规检查免疫球蛋白(IgG、IgA、IgM)指标,以便调节机体的免疫力及为系统、规范化诊疗提供新的诊断依据。"气池"改变与免疫球蛋白指标变化关系的研究为儿科望诊新增添的内容。     

血清白蛋白检测方法对糖化白蛋白的影响

随机抽取306份不同白蛋白( Alb)浓度的新鲜血清标本,分别用溴甲酚绿法( BCG)、改良溴甲酚紫法( mBCP)、免疫比浊法( ITA )检测 Alb 浓度,液态酶法检测糖化白蛋白( GA) ,并计算GA值[ GA%(%) =GA/Alb × 100%]. 正常Alb浓度( Alb≥ 40 g/L )时, BCG 与 mBCP 法、BCG 与 ITA法、mBCP与ITA法检测结果比较,临床差异不明显,而且GA% BCG与GA% mBCP比较,差异无统计学意义( P=0. 537 );低Alb浓度( Alb<40 g/L)时,BCG法分别与mBCP、ITA法比较差异有统计学意义( P < 0. 01 ) , GA% BCG明显低于GA% mBCP ( P <0. 01 ). 故正常 Alb 浓度时, BCG、mBCP 与ITA 法三者结果差异无明显临床意义,各法用于GA%计算无明显差异;但低Alb浓度时,mBCP与ITA法二者一致性优于BCG与ITA法,若使用BCG法则GA%结果可能被低估.     

Purple Sweet Potato Color Alleviates D‐galactose‐induced Brain Aging in Old Mice by Promoting Survival of Neurons via PI3K Pathway and Inhibiting Cytochrome C‐mediated Apoptosis

Purple sweet potato color (PSPC), a class of naturally occurring anthocyanins, protects brain function against oxidative stress induced by D‐galactose (D‐gal) (Sigma‐Aldrich, St. Louis, MO, USA). Our data showed that PSPC enhanced open‐field activity, decreased step‐through latency, and improved spatial learning and memory ability in D‐gal‐treated old mice by decreasing advanced glycation end‐products'' (AGEs) formation and the AGE receptor (RAGE) expression, and by elevating Cu,Zn‐superoxide dismutase (Cu,Zn‐SOD) (Sigma‐Aldrich) and catalase (CAT) expression and activity. Cleavage of caspase‐3 and increased terminal deoxynucleotidyl transferase (TdT)‐mediated deoxyuridine triphosphate (dUTP) nick‐end‐labeling (TUNEL)‐positive cells in D‐gal‐treated old mice were inhibited by PSPC, which might be attributed to its antioxidant property. PSPC also suppressed the activation of c‐Jun NH₂‐terminal kinase (JNK) and the release of cytochrome c from mitochondria that counteracted the onset of neuronal apoptosis in D‐gal‐treated old mice. Furthermore, it was demonstrated that phosphoinositide 3‐kinase (PI3K) activation was required for PSPC to promote the neuronal survival accompanied with phosphorylation and activation of Akt and p44/42 mitogen‐activated protein kinase (MAPK) by using PI3K inhibitor LY294002 (Cell Signaling Technology, Inc., Beverly, MA, USA), implicating a neuronal survival mechanism. The present results suggest that neuronal survival promoted by PSPC may be a potentially effective method to enhance resistance of neurons to age‐related disease.