Nucleic acid crystallography: a view from the nucleic acid database

What are the future directions of the field of nucleic acid crystallography? Although there have been many duplex structures determined, the sample is still relatively small. This is especially true if one wants to derive enough information about the relationships between sequence and structure. Indeed, there are data for all the possible 10 dimer steps, but for some steps it is very limited. If the structural code resides in trimers or tetrad steps then there is simply not enough data to do meaningful statistical analyses. So the first direction that needs to be explored is the determination of more structures with more varied sequences. The other noticeable thing about the data is the shortness of the strands. While it is probably true that attempts to crystallize very long sequences will not meet with success, the idea of crystallizing sequences engineered to fit together via sticky ends such as has been done for the CAP-DNA complex (Schultz et al., 1990) should give data about the behavior of much longer stretches of DNA. The question of the effects of environment on the structure of DNA continues to be a very important one to address since DNA is rarely alone. The preliminary data we have analysed from the current sample shows that the conformation of some steps are very sensitive to packing type. Numerous studies of the hydration around DNA shows that there is a real synergy between the hydration structure and the base conformation. More data will allow further quantitation of these observations. RNA structure is the next very exciting frontier. The emerging structures of duplexes with internal loops, the two hammerhead ribozyme structures and the group I intron ribozyme have given us a glimpse of the complexity and elegance of this class of molecules. With the technology now in place to allow the determination of the structures of these molecules, the expectation is that now we will see a large increase in the number of these structures in the NDB.     

Haemophilia A and the blood transfusion service: a Scottish study

The demand for blood products containing factor VIII for treating patients with haemophilia A in south-east Scotland was reviewed. From 1961 to 1975 the demand for fresh frozen plasma (FFP), cryoprecipitate (CP), and antihaemophilic factor (AHF) increased by seven and a half times, while total donations increased by only a third. Patients with severe haemophilia A treated at the regional haemophilia centre used about 85% of the factor VIII issued in 1971-4, most of which was used on demand. A patient with severe haemophilia A on unlimited ondemand home treatment would need about 500 units of factor VII/kg body weight/year, and a regional haemophilia centre, treating moderate and mild cases as well as severe ones, would use 15000 units/patient/year. Altogether about 50 million units of factor VIII will be needed each year in the UK. Although cryoprecipitate is much harder to store and administer than AHF, its yield from plasma may be far greater and its cost far smaller. Unless the blood transfusion services receive increased amounts of money and reappraise their functions and operation, it seems likely that they will have to rely increasingly on commercial (and costly) sources for the major plasma fractions.     

Mandatory continuing education for licensed psychologists: Its rationale and current implementation.

We review literature on effectiveness of continuing education (CE) in enhancing quality of services in health professions. We conclude that if CE is properly implemented, health care can be positively impacted. Two examples of effective CE programs are described. We also review current status of mandatory CE (MCE) in health fields, especially psychology. Most MCE systems do not meet criteria of good CE systems. The profession of psychology is encouraged to shift to more effective systems of MCE. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Provocative testing for coronary arterial spasm: rationale, risk and clinical illustrations

Two cases of Prinzmetal's variant angina are presented in which coronary spasm was documented by electrocardiographic evidence obtained in the coronary care unit during provocative testing with ergonovine maleate after the arteriographic demonstration of anatomically normal coronary arteries. The rationale and risks of provocative testing for spasm in patients with chest pain and anatomically normal coronary arteries are reviewed. The advantages of performing provocative testing in the coronary care unit after arteriography rather than in the catheterization laboratory during coronary arteriography are discussed.     

Predictors of success on the Canadian Nurses Association testing service (CNATS) examination

This retrospective study examined the relationship of selected admissions variables and in-course performance to success in the Canadian Nurses Association Testing Service (CNATS) examinations of 114 students admitted directly from secondary school to a four-year integrated, problem-based learning (PBL) baccalaureate nursing program in Canada. Data were analyzed using two separate hierarchical stepwise regression equations. The first equation examined a set of secondary school grades (Ontario Academic Credits, or OACs) used to calculate university admission averages and their ability to predict CNATS performance. OAC English was found to be the best predictor, followed by OAC chemistry and the admission average obtained on other OAC subjects. The second regression equation looked at in-course grades as potential predictors of CNATS scores. The basic sciences variable proved to be the best predictor, followed by research methodology, first-year Nursing Concepts I, a problem-based nursing average, and a clinical practice average. Findings support the continued use of English and chemistry as admission criteria. The basic sciences courses and first-year nursing courses also emerged as statistically significant predictors of licensure examination success.     

DNA adducts in human breast tissue: association with N-acetyltransferase-2 (NAT2) and NAT1 genotypes

An intriguing development in the G-protein signaling field has been the finding that not only the Galpha subunit, but also Gbetagamma subunits, affect a number of downstream target molecules. One of the downstream targets of Gbetagamma is adenylyl cyclase, and it has been demonstrated that a number of isoforms of adenylyl cyclase can be either inhibited or stimulated by Gbetagamma subunits. Until now, adenylyl cyclase type I has been the only isoform reported to be inhibited by free Gbetagamma. Here we show by transient cotransfection into COS-7 cells of either adenylyl cyclase V or VI, together with Ggamma2 and various Gbeta subunits, that these two adenylyl cyclase isozymes are markedly inhibited by Gbetagamma. In addition, we show that Gbeta1 and Gbeta5 subunits differ in their activity. Gbeta1 transfected alone markedly inhibited adenylyl cylcase V and VI (probably by recruiting endogenous Ggamma subunits). On the other hand, Gbeta5 produced less inhibition of these isozymes, and its activity was enhanced by the addition of Ggamma2. These results demonstrate that adenylyl cyclase types V and VI are inhibited by Gbetagamma dimers and that Gbeta1 and Gbeta5 subunits differ in their capacity to regulate these adenylyl cyclase isozymes.     

Development and implementation of a perioperative autologous service program

Several months after we initiated our PAS program, the AABB scrutinized our policy and procedure manual. At the same time, the JCAHO conducted an inspection of our blood bank and its standards. Both reviews were positive, which provided all of us involved in the PAS program with a tremendous sense of accomplishment. Each PAS team member played a significant role in the development and implementation of our PAS program. Thanks to the energy, enthusiasm, and support of perioperative nurses, surgeons, and hospital administrators, our PAS program has evolved into a high quality, efficient alternative to homologous blood transfusions in the perioperative setting.     

Influence of the microencapsulation method and peptide loading on poly(lactic acid) and poly(lactic-co-glycolic acid) degradation during in vitro testing

Three methods were used, namely spray drying, w/o/w solvent evaporation and the aerosol solvent extraction system (ASES), for the preparation of microparticles having the same size range, to study the influence of the preparation method on polymer degradation in vitro (PBS, 37 degrees C, one month). The following five polymers of the biodegradable poly(lactic acid) (PLA) and poly(lactic-co-glycolic acid) (PLGA) group were selected: L-PLA, MW 81 200; DL-PLGA 75:25, MW 64-300; DL-PLGA 50:50 MW 52 600; DL-PLGA 50:50 MW 14 500, AND DL-PLGA 50:50, MW 3400, to prepare drug-free and drug-loaded microparticles. Tetracosactide was selected as model peptide. When microparticles were prepared by solvent evaporation, the mean diameter and, more markedly, the drug encapsulation efficiency tended to decrease when decreasing the molecular weight and increasing the proportion of glycolic acid in the polymer. In contrast, no direct influence of the polymer nature on these parameters was observed in spray dried microparticles. Polymer degradation was heterogenous in L-PLA and DL-PLGA 75:25 microparticles and was not influenced by the presence of the drug at a nominal loading of 1% (w/w), when prepared by the three methods (note that with ASES, only L-PLA could be used for microencapsulation). In batches made of DL-PLGA 50:50 MW 52 600, the degradation rate decreased slightly when increasing the drug loading. Only in the case of DL-PLGA 50:50 MW 14 500, the polymer degradation rate for spray dried microparticles was higher compared to that for microparticles prepared by the w/o/w solvent evaporation method. Generally, the degradation rates of the different microparticles followed the expected order: L-PLA相似文献   

Constitutive cyclooxygenase (COX-1) and inducible cyclooxygenase (COX-2): rationale for selective inhibition and progress to date

While a great deal has been discovered concerning the potential physiological and pathological role of prostanoids, much is left to be determined. The widespread distribution of both COX-1 and COX-2 coupled with the capacity of most vascular beds, smooth muscle, as well as leukocytes to respond to prostanoids make drawing generalities difficult. The problems with the majority of currently used NSAIDs are clear and ulcerogenic liability is of obvious concern. Interestingly enough, the mechanism of that damage is still the subject of controversy as illustrated by the recent review and hypothesis of Somasundaram et al. In this treatise, the suggestion is made that the initial gastric damage is the result of uncoupling of oxidative phosphorylation which is independent but simultaneous with COX inhibition. At least two currently marketed NSAIDs have improved G.I. liability (nabumetone and etodolac) with efficacy equivalent to other more ulcerogenic NSAIDs. These drugs appear to have achieved that by a mechanism distinct from selective inhibition of COX-2. Whether or not selective COX-2 inhibitors will demonstrate an improved profile over these compounds remains to be shown. Unfortunately, clinical experience with nimsulide and CGP 28238 suggest that NSAID-like toxicity may still be an issue. The promise of selective COX-2 inhibitors remains largely untested. It is with great interest and expectation that the clinical evaluation of the more selective compounds of different structural types is awaited.     

Anti-Rd (Radin) following the transfusion of a Radin positive unit of blood

Anti-Rd (Radin) was first described in association with five cases of hemolytic disease of the newborn. The authors report an anti-Rd that was demonstrated following the transfusion of a Radin positive unit of blood. The antibody appears to be of the IgG immunoglobulin class and increased in titer following the transfusion.     

The Edinburgh Extended Glasgow Outcome Scale (EEGOS): rationale and pilot studies

OBJECTIVES: To determine whether patch angioplasty is more effective than primary closure in carotid endarterectomy, and whether one type of patch is better than another. DESIGN: Systematic review of the randomised trials. MATERIALS: Trials were identified from the Cochrane Stroke Review Group database plus additional handsearching, electronic searching, and personal contact. METHODS: Two authors independently selected studies for inclusion and extracted details of trial quality and data on the following outcomes: any stroke; stroke ipsilateral to the operated artery; death; occlusion or restenosis, and other significant arterial complications. Meta-analysis of odds ratios (OR) was performed using the Peto method. RESULTS: Six trials (882 operations) compared routine patching with primary closure. Routine patching was associated with significant reductions in the risks of ipsilateral stroke during the perioperative period (OR 0.34, 95% CI 0.15-0.76) and during long-term follow-up (OR 0.38, 95% CI 0.16-0.88). Significant reductions in the odds of any stroke, stroke or death, acute arterial occlusion and long-term restenosis were also found. However, these results were based on very small numbers of outcome events and may be biased by losses to follow-up and publication bias. Three trials (326 operations) compared the use of polytetrafluoroethylene patches with venous patches. There were too few events (strokes, deaths, arterial complications) to determine whether there were significant differences between the patch materials. Fewer pseudoaneurysms occurred in those who received synthetic patches but the clinical consequence of this was unclear. CONCLUSIONS: Routine carotid patch angioplasty was associated with promising reductions in the risks of ipsilateral stroke and death, but the results should be interpreted cautiously because of the small number of outcome events, significant losses to follow-up, and poor trial methodology. Ideally, a large definitive trial should be performed. There is insufficient evidence to support the preferential use of one particular type of patch versus another.     

Thoracic and lumbar deformity: rationale for selecting the appropriate fusion technique (Anterior, posterior, and 360 degree)

The rationale of anterior versus posterior, or combined fusion is discussed with regards to different clinical diagnoses and situations. Factors involved in the decision-making process include stability, magnitude of deformity, rigidity of deformity, neurologic considerations, bone quality, and medical/metabolic factors. Careful preoperative assessment and planning are required as well as consideration for the patient's overall well being.     

N-Acetyltransferase 2 (NAT2) and Glutathione S-Transferase μ (GSTM1) in Bladder-cancer Patients in a Highly Industrialized Area

The gene encoding the 33 kDa piroplasm surface protein of Theileria sergenti isolated in Korea was cloned and the nucleotide sequence was determined by dideoxy chain termination method. The cloned gene corresponds to 869 bp encoding an open reading frame 283 amino acids. Comparison of the sequence between Korean and Japanese isolates showed 99.4% homology rate in the nucleotide sequence and 98.9% homology rate in the amino acid sequence.     

基于SOA架构的物流信息系统的相关技术研究与实现

以物流信息系统为实例,针对原有物流信息系统存在灵活性差等一系列问题,通过深入分析面向服务的体系结构(SOA)的相关理论,利用网络服务技术,提出了一种基于SOA架构的企业应用设计流程和建模方法.讨论了在跨语言、跨操作系统的平台下实现\     

The Ontario Prehospital Advanced Life Support (OPALS) Study: rationale and methodology for cardiac arrest patients

Modalities of management of arterio-venous malformations are discussed according to natural history and size of lesion, patient clinical status, and potential side effects of available techniques (microsurgery, radiosurgery, ambolization). Clinical cases illustrate this discussion.     

铜冶炼厂现有最佳硫酸生产技术:最新总结

在不远的将来,硫的捕集是铜冶炼厂的主要目标和挑战之一。已制定了增大硫捕集率的目标,技术供应商已为达成这些目标作好了准备。现代硫酸厂配有高效的烟气净化系统,可以保证硫酸的高洁净度,同时维持制酸的较低成本。目前制酸技术已非常成熟,硫酸厂可以直接处理体积浓度高达30%的烟气,并保证要求的尾气浓度。捕集铜冶炼厂中各种来源的SO2烟气生产硫酸,满足所需的硫捕集目标是一种实际的选择。本文对解决该行业烟气制酸问题提出了种种构想。     

Is there a rationale for eradication of Helicobacter pylori? Cost-benefit: the case for

Although the items within the WAIS-R subtests are presumed to be in ascending order of difficulty, several studies have indicated that the Picture Arrangement subtest items are out of order for clinical groups. The present study retrospectively examined item difficulty and discrimination in the test data of 74 individuals who had been referred for neuropsychological assessment following a traumatic brain injury. While results were not statistically significant, qualitative analysis of partial credit scoring for four of the items indicated some inconsistencies in the scoring rationale. Caution is recommended in the use and interpretation of the Picture Arrangement tests scores in the assessment of individuals with traumatic brain injury.