Performance of different mono- and multiplex nucleic acid amplification tests on a multipathogen external quality assessment panel

An external quality assessment (EQA) panel consisting of a total of 48 samples in bronchoalveolar lavage (BAL) fluid or transport medium was prepared in collaboration with Quality Control for Molecular Diagnostics (QCMD) (www.qcmd.org). The panel was used to assess the proficiency of the three laboratories that would be responsible for examining the 6,000 samples to be collected in the GRACE Network of Excellence (www.grace-lrti.org). The main objective was to decide on the best-performing testing approach for the detection of influenza viruses A and B, parainfluenza virus types 1 to 3, respiratory syncytial virus (RSV), human metapneumovirus, coronavirus, rhinovirus, adenovirus, Chlamydophila pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila by nucleic acid amplification techniques (NAATs). Two approaches were chosen: (i) laboratories testing samples using their in-house procedures for extraction and amplification and (ii) laboratories using their in-house amplification procedures on centrally extracted samples. Furthermore, three commercially available multiplex NAAT tests-the ResPlex (Qiagen GmbH, Hilden, Germany), RespiFinder plus (PathoFinder, Maastricht, The Netherlands), and RespiFinder Smart 21 (PathoFinder) tests-were evaluated by examination of the same EQA panel by the manufacturer. No large differences among the 3 laboratories were noticed when the performances of the assays developed in-house in combination with the in-house extraction procedures were compared. Also, the extraction procedure (central versus local) had little effect on performance. However, large differences in amplification efficacy were found between the commercially available tests; acceptable results were obtained by using the PathoFinder assays.     

Paired Ventricular Pacing: An Alternative Therapy for Postoperative Junctional Ectopic Tachycardia in Congenital Heart Disease

Junctional ectopic tachycardia (JET) is one of the most life-threatening postoperative arrhythmias in children with congenital heart disease, and medical management is difficult. Paired ventricular pacing (PVP) may provide a safe alternative mode of management. We evaluated the safety and efficacy of PVP for the management of postoperative JET in patients with congenital heart disease. A retrospective collection of data was done from 1981-1995. PVP was successfully tried in five postoperative patients (age range: 37 days to 22 years, median: 10 months). Onset of JET was 3-60 hours (mean +/- SD, 19 +/- 23 hours) postoperatively. The maximal JET rate was 261 +/- 39 beats/min. PVP was used as the first line of management in three patients and was successful in all patients. It resulted in an instantaneous increase in blood pressure from 66 +/- 9 to 94 +/- 15 mmHg (42% increase) and was required for 12 +/- 14 hours (range 2-36 hours). No complications were noted. Therefore, in our experience, this is a safe alternative modality for the control of postoperative JET.     

An Artificial Intelligence System for Computer-Assisted Menu Planning

Planning nutritious and appetizing menus is a complex task that researchers have tried to computerize since the early 1960s. We have attempted to facilitate computer-assisted menu planning by modeling the reasoning an expert dietitian uses to plan menus. Two independent expert systems were built, each designed to plan a daily menu meeting the nutrition needs and personal preferences of an individual client. One system modeled rule-based, or logical, reasoning, whereas the other modeled case-based, or experiential, reasoning. The 2 systems were evaluated and their strengths and weaknesses identified. A hybrid system was built, combining the best of both systems. The hybrid system represents an important step forward because it plans daily menus in accordance with a person's needs and preferences; the Reference Daily Intakes; the Dietary Guidelines for Americans; and accepted aesthetic standards for color, texture, temperature, taste, and variety. Additional work to expand the system's scope and to enhance the user interface will be needed to make it a practical tool. Our system framework could be applied to special-purpose menu planning for patients in medical settings or adapted for institutional use. We conclude that an artificial intelligence approach has practical use for computer-assisted menu planning. J Am Diet Assoc. 1998;98:1009-1014.     

Impact of age on management and outcome of acute coronary syndrome: observations from the Global Registry of Acute Coronary Events (GRACE)

Background

Evidence-based cardiac therapies are underutilized in elderly patients. We assessed differences in practice patterns, comorbidities, and in-hospital event rates, by age and type of acute coronary syndrome (ACS).

Methods

We studied 24165 ACS patients in 102 hospitals in 14 countries stratified by age.

Results

Approximately two-thirds of patients were men, but this proportion decreased with age. In elderly patients (≥ 65 years), history of angina, transient ischemic attack/stroke, myocardial infarction(MI), congestive heart failure, coronary artery bypass graft (CABG) surgery, hypertension or atrial fibrillation were more common, and delay in seeking medical attention and non-ST-segment elevation MI were significantly higher. Aspirin, β-blockers, thrombolytic therapy, statins and glycoprotein IIb/IIIa inhibitors were prescribed less, while calcium antagonists and angiotensin-converting enzyme inhibitors were prescribed more often to elderly patients. Unfractionated heparin was prescribed more often in young patients, while low-molecular-weight heparins were similarly prescribed across all age groups. Coronary angiography and percutaneous intervention rates significantly decreased with age. The rate of CABG surgery was highest among patients aged 65-74 years (8.1%) and 55-64 years (7.7%), but reduced in the youngest (4.7%) and oldest (2.7%) groups. Major bleeding rates were 2-3% among patients aged < 65 years, and > 6% in those ≥ 85 years. Hospital-mortality rates, adjusted for baseline risk differences, increased with age (odds ratio: 15.7 in patients ≥ 85 years compared with those < 45 years).

Conclusions

Many elderly ACS patients do not receive evidence-based therapies, highlighting the need for clinical trials targeted specifically at elderly cohorts, and quality-of-care programs that reinforce the use of such therapies among these individuals.     

Global patterns of use of antithrombotic and antiplatelet therapies in patients with acute coronary syndromes: insights from the Global Registry of Acute Coronary Events (GRACE)

Background

Many agents are available to treat acute coronary syndromes (ACS), yet limited information is available about their use from a multinational perspective. The objective of this report was to describe patterns of use of antithrombotic and antiplatelet therapies in patients with the spectrum of ACS through the use of data from the Global Registry of Acute Coronary Events (GRACE).

Methods

Data from 12,665 patients with ACS were analyzed. Baseline characteristics, clinical presentation, and medication use were compared. Regional differences in the administration of antiplatelet and antithrombotic therapies were analyzed. Multivariable logistic regression was implemented to determine independent variables indicating the use of various hospital therapies.

Results

Overall, unfractionated heparin was used in 57% of patients and low-molecular-weight heparin in 47% (P < .0001). More than 90% of patients received aspirin, but approximately 13% were not discharged on aspirin. Overall, 30% of patients received thienopyridines (with percutaneous coronary intervention [PCI] in 79%). Of those who did not receive aspirin, 31% received thienopyridines. Intravenous glycoprotein inhibitors were given to 17% of patients. Among those treated with PCI, only 47% received glycoprotein inhibitors, and 21% of those given glycoprotein inhibitors did not undergo PCI. Significant geographic variation was apparent in the use of unfractionated heparin, low-molecular-weight heparin, thienopyridines, and glycoprotein inhibitors.

Conclusions

Despite the availability of guidelines, striking geographic and practice variations are apparent in the use of antithrombotic and antiplatelet therapies. There remains significant room for improvement in the use of these therapies in patients with ACS, which should lead to improvement in care and outcomes.     

An assessment of the Coulter VCS automated differential counter scatterplots in the recognition of specific acute leukaemia variants

Summary The Coulter VCS is an automated differential counter, which derives a five-part differential count on the basis of differences in cell volume, high frequency conductivity and light scatter. A printed scatterplot relating volume and scatter is readily obtained. Other instruments which use automated cytochemistry can distinguish between AML and ALL, and between AML variants. It was our impression that the Coulter VCS might also be capable of such distinction on the basis of the scatterplot patterns. We therefore collected scatterplots produced by Coulter VCS analysis of peripheral blood from 63 patients presenting with acute leukaemia. The scatterplots were inspected and six basic patterns identified. The scatterplots could be reproducibly sorted into pattern-specific groups without knowledge of the diagnosis. Precise leukaemic diagnoses were made routinely by conventional morphology, cytochemistry and immunophenotyping. A comparison was then made with the scatterplot patterns. The 51 cases of AML produced examples of all six patterns. The nine cases of ALL produced only three patterns. These were shared with cases of AML, and two were also shared with the three cases of acute mixed lineage leukaemia. Thus, three of the six patterns were specific for AML, whereas no pattern was specific for ALL or acute mixed lineage acute leukaemia. One pattern was produced only by the three cases of AML M6, and another was produced only by five of the 25 cases of primitive (MO and Ml) AML. All 15 cases of AML M4 and M5 produced one of two related patterns. These were shared with other AML variants, and one was also shared with ALL. In conclusion, analysis of the Coulter VCS scatterplots was capable, in the case of some patterns, of distinguishing between AML and ALL, and between some AML variants.