甲状腺素运载蛋白时间分辨免疫荧光试剂盒的制备和效能评价

目的制备甲状腺素运载蛋白(transthyretin,TTR)的时间分辨免疫荧光(time-resolved fluoroimmunoassay,TRFIA)试剂盒并对其性能进行评价。方法将抗TTR的4H2单克隆抗体作为包被抗体包被至96孔板,用Eu^3+标记3E4单克隆抗体作为检测抗体,制备双抗体夹心TRFIA试剂盒,应用该试剂盒对42例川崎病(Kawasaki disease,KD)患儿及13名健康儿童的血清进行检测,以稀释回收率、准确度、精密度、稳定性等指标对试剂盒的效能进行评价。结果该研究制备的TTR TRFIA试剂盒与Western blot法同时检测42份KD临床样本和13份健康样本,两方法的结果符合率为100%,特异性强。试剂盒的最低检出浓度为0.05μg/ml,稀释回收率为88.00%~111.00%,分析内精密度为8.01%~9.17%,分析间精密度为8.88%~11.82%。稳定性实验表明该试剂盒可在4℃稳定保存6个月,37℃稳定保存7 d。结论该研究制备的TTR TRFIA试剂盒具有准确性高、方便快捷等优点,适用于大批量临床KD血清样品的TTR检测,为快速区分丙种球蛋白敏感型和无反应型的KD患儿提供了方法。     

露髓孔在龋源性牙髓病诊断中的意义

目的探讨露髓孔在龋源性牙髓病诊断中的意义,以及露髓孔大小与温度试验结果的关系,以提高龋源性牙髓病诊断的准确性。方法对391例经探诊、叩诊及温度试验等检查,初步诊断为牙髓病后局麻,用球钻及龋洞挖匙基本去除软化牙本质,再用探针探查穿髓孔情况。结果全部病例均有大小不等的露髓孔。大部分牙髓部分坏死及露髓孔大的慢性牙髓炎病例,温度试验结果类似可复性牙髓炎;慢性牙髓炎急性发作温度试验结果与露髓孔大小关系不大。结论露髓孔可作为诊断龋源性牙髓病的主要依据;温度试验刺激去除后疼痛立即消失,并不是可复性牙髓炎的特有表现。     

Atrial Fibrillation and Cognitive Function: JACC Review Topic of the Week

Numerous vascular risk factors and vascular diseases contribute to cognitive impairment and dementia. Many studies and registries show an association of atrial fibrillation (AF) with cognitive impairment, cognitive decline, and dementia. This is true for vascular dementia and Alzheimer's disease. The assumed multifactorial mechanisms include ischemic stroke, both apparent and silent, cerebral microinfarcts, cerebral hemorrhage, and reduced cerebral blood flow. A number of retrospective observational and prospective studies support that anticoagulation in patients with AF may reduce the risk of cognitive decline and dementia. This holds for both vitamin K antagonists (e.g., warfarin) and direct oral anticoagulants. However, it still remains unproven if anticoagulation reduces cognitive decline and dementia in AF patients based on randomized trials.     

英国药典2007年版简介

本文对英国药典2007年版的的基本情况、编排结构进行了简要介绍,并对英国药典2007年版和2005年版的不同之处进行了比较。     

Formylated N-terminal methionine is absent from the Mycoplasma hyopneumoniae proteome: Implications for translation initiation

N-terminal methionine excision (NME) is a proteolytic pathway that cleaves the N-termini of proteins, a process that influences where proteins localise in the cell and their turnover rates. In bacteria, protein biosynthesis is initiated by formylated methionine start tRNA (fMet-tRNA_f^Met). The formyl group is attached by formyltransferase (FMT) and is subsequently removed by peptide deformylase (PDF) in most but not all proteins. Methionine aminopeptidase then cleaves deformylated methionine to complete the process. Components of NME, particularly PDF, are promising therapeutic targets for bacterial pathogens. In Mycoplasma hyopneumoniae, a genome-reduced, major respiratory pathogen of swine, pdf and fmt are absent from its genome. Our bioinformatic analysis uncovered additional enzymes involved in formylated N-terminal methionine (fnMet) processing missing in fourteen mycoplasma species, including M. hyopneumoniae but not in Mycoplasma pneumoniae, a major respiratory pathogen of humans. Consistent with our bioinformatic studies, an analysis of in-house tryptic peptide libraries confirmed the absence of fnMet in M. hyopneumoniae proteins but, as expected fnMet peptides were detected in the proteome of M. pneumoniae. Additionally, computational molecular modelling of M. hyopneumoniae translation initiation factors reveal structural and sequence differences in areas known to interact with fMet-tRNA_f^Met. Our data suggests that some mycoplasmas have evolved a translation process that does not require fnMet.     

Familial amyloidotic polyneuropathy: Description of an Italian kindred

Familial amyloidotic polyneuropathy (FAP) is a heterogeneous group of genetic disorders characterized by progressive systemic deposition of extracellular amyloid fibrils, mainly affecting the peripheral nervous system (PNS). These disorders, inherited as an autosomal dominant trait, have frequently been described in various ethnic groups, but have rarely been reported in Italy. A 42 year-old man came to our observation for loss of pain and temperature sense in his legs. Clinical and laboratory data pointed to an amyloidotic polyneuropathy. This led us to discover a large italian kindred in which 19 members were affected by FAP. The diagnosis, established in 8 members on the clinical and laboratory findings, was ana-catamnestic in other 11. In this kindred the onset of the disease ranges from 35 to 50 years of age and the course is progressive and often fatal. The early symptoms are mainly related to autonomic disturbances and to peripheral neuropathy. Cardiac and renal involvement occurs frequently and may be life-threatening. Le Polineuropatie Amiloidosiche Familiari (FAP) sono un gruppo eterogeneo di affezioni trasmesse in via autosomica dominante caratterizzate dalla deposizione sistemica di fibrille amiloidi e dall'interessamento preminente del Sistema Nervoso Periferico (SNP). Queste affezioni, descritte frequentemente in vari gruppi etnici, sono state raramente segnalate in Italia. L'osservazione di un 42enne, venuto alla nostra osservazione per una perdita della sensibilità termo-dolorifica agli arti inferiori, ci ha consentito l'identificazione di una estesa famiglia italiana con 19 membri affetti da FAP. La diagnosi era basata su dati clinico-strumentali in 8 soggetti e su notizie anacatamnestiche in altri 11. Nella famiglia da noi studiata la malattia esordisce tra i 35 e i 50 anni di età e il decorso è progressivo e spesso fatale.     

Glucose fluctuations and activation of oxidative stress in patients with type 1 diabetes

AIMS/HYPOTHESIS: Glucose fluctuations may help predict diabetic complications. We evaluated the relation between glucose variability and oxidative stress in patients with type 1 diabetes. METHODS: Continuous glucose monitors were inserted subcutaneously in 25 patients. During the measurement, patients collected two 24 h urine samples, while 24 healthy controls collected one 24 h urine sample for determination of 15(S)-8-iso-prostaglandin [Formula: see text] using HPLC tandem mass spectrometry. Mean of the daily differences (MODD), mean amplitude of glycaemic excursions (MAGE) and continuous overlapping net glycaemic action calculated with n hour time-intervals (CONGA-n) were calculated as markers for glucose variability and correlation with [Formula: see text] excretion was calculated. RESULTS: Median [interquartile range (IQR)] urinary [Formula: see text] was higher in patients than healthy controls: 161 (140-217) pg/mg creatinine vs 118 (101-146) pg/mg creatinine (p = 0.001). Median (IQR) MODD was 3.7 (3.2-5.0) mmol/l, MAGE 7.6 (6.4-9.0) mmol/l and CONGA-1 2.3 (2.1-2.8) mmol/l. Univariate regression did not reveal an association for MODD (r (2) = 0.01), MAGE (0.08) or CONGA-1 (0.07) with [Formula: see text] excretion, nor was an association revealed when corrected for HbA(1c), age, sex and smoking. Spearman correlation coefficients (r) between [Formula: see text] excretion and MODD, MAGE and CONGA-1 were non-significant: -0.112, -0.381 and -0.177. CONCLUSIONS/INTERPRETATION: We report that there is no relationship between glucose variability and urinary [Formula: see text]. We also confirm that patients with type 1 diabetes have higher levels of urinary [Formula: see text] than healthy controls, suggesting that in addition to glucose variability, other factors favouring oxidative stress may exist. We did not see a relation between high glucose variability and elevated levels of oxidative stress in patients with type 1 diabetes.     

The leveling-off of oxygen uptake is related to blood lactate accumulation. Retrospective study of 94 elite rowers

To assess whether the ability to demonstrate a plateau in oxygen consumption VO2 could be related to adaptation to exercise, the data obtained over a period of 10 years on 94 elite oarsmen who had participated in annual testing were re-evaluated. The test consisted in an incremental step protocol until volitional exhaustion. VO2, heart rate (HR), blood lactate ([La]b) and respiratory exchange ratio (RER) were measured at each step. The maximal oxygen consumption (VO2max), the power corresponding to VO2maxPamax and the maximal power achieved (Ppeak) were recorded. Thirty-eight oarsmen achieved a VO2 plateau and were designated as Pla; 56 did not and were designed as N-Pla. The Pla and N-Pla VO2max, Pamax and maximal HR values were similar. In comparison with N-Pla, the Pla group displayed a rightward shift of the [La]b versus power curve, accounted for by both the increased percentage of VO2max corresponding to 4 mmol l(-1) and the decreased value of [La]b corresponding to Pamax (P<0.05). Pla oarsmen attained a higher Ppeak expressed as % of Pamax (P<0.05) and also showed better ergometer performance (P<0.05). In a sub-group of 53 oarsmen constituted on the basis of Pamax values close to 400 W, for a given power output, the Pla subjects had significantly lower HR, RER, and [La]b values at each sub-maximal stage of the test. These results suggest that achieving a [Formula: see text] plateau during completion of an incremental step protocol accounts for greater muscle ability to maintain homeostasis during exercise. These differences give the oarsmen an advantage in rowing competitions.     

Effect of prior heavy exercise on muscle deoxygenation kinetics at the onset of subsequent heavy exercise

This study examines the effect of prior heavy exercise on muscle deoxygenation kinetics at the onset of heavy-intensity cycling exercise. Ten young male adults (20 +/- 2 years) performed two repetitions of step transitions (6 min) from 35 W to heavy-intensity exercise preceded by either no warm-up or by a heavy-intensity exercise. VO2 was measured breath-by-breath, and muscle deoxygenation (HHb) and total hemoglobin (Hb(tot)) were monitored continuously by near-infrared spectroscopy. We used a two-exponential model to describe the VO2 kinetics and a mono-exponential model for the HHb kinetic. The parameters of the phase II VO2 kinetics (TD1 VO2, tau1 VO2 and A1 VO2) were unaffected by prior heavy exercise, while some parameters of local muscle deoxygenation kinetics were significantly faster (TD HHb: 7 +/- 2 vs. 5 +/- 2 s; P < 0.001, MRT HHb: 20 +/- 3 vs. 15+/- 4 s; P < 0.05). Blood lactate, heart rate and Hb(tot) values were significantly higher before the second bout of heavy exercise. These results collectively suggest that the prior heavy exercise probably increased muscle O2 availability and improved O2 utilization at the onset of a subsequent bout of heavy exercise.     

Examination of the effects of virus inactivation methods on the induction of antibody- and cell-mediated immune responses against whole inactivated H9N2 avian influenza virus vaccines in chickens

Several types of avian influenza virus (AIV) vaccines exist, including live-attenuated, vectored, and whole inactivated virus (WIV) vaccines. Inactivated vaccines offer some advantages compared to other types of vaccines, including ease of production and lack of ability to revert to a virulent state. However, WIV are poorly immunogenic, especially when these vaccines are delivered to mucosal surfaces. There are several factors that contribute to the immunogenicity of vaccines, one of which is the method used to inactivate viruses. Several methods exist for producing influenza WIVs, including formaldehyde, a chemical that affects protein structures leading to virus inactivation. Other methods include treatment with beta-propiolactone (BPL) and the application of gamma radiation, both of which have less effects on protein structures compared to formaldehyde, and instead alter nucleic acids in the virion. Here, we sought to determine the effect of the above inactivation methods on immunogenicity of AIV vaccines. To this end, chickens were vaccinated with three different H9N2 WIVs using formaldehyde, BPL, and gamma radiation for inactivation. In addition to administering these three WIVs alone as vaccines, we also included CpG ODN 2007, a synthetic ligand recognized by Toll-like receptor (TLR)21 in chickens, as an adjuvant for each WIV. Subsequently, antibody- and cell-mediated immune responses were measured following vaccination. Antibody-mediated immune responses were increased in chickens that received the BPL and Gamma WIVs compared to the formaldehyde WIV. CpG ODN 2007 was found to significantly increase antibody responses for each WIV compared to WIV alone. Furthermore, we observed the presence of cell-mediated immune responses in chickens that received the BPL WIV combined with CpG ODN 2007. Based on these results, the BPL WIV + CpG ODN 2007 combination was the most effective vaccine at inducing adaptive immune responses against H9N2 AIV. Future studies should characterize mucosal adaptive immune responses to these vaccines.