SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Standardization

174

As reports on possible associations between microbes and the host increase in number, more meaningful interpretations of this information require an ability to compare data sets across studies. This is dependent upon standardization of workflows to ensure comparability both within and between studies. Here we propose the standard use of an alternate collection and stabilization method that would facilitate such comparisons. The DNA Genotek OMNIgene∙Gut Stool Microbiome Kit was compared to the currently accepted community standard of freezing to store human stool samples prior to whole genome sequencing (WGS) for microbiome studies. This stabilization and collection device allows for ambient temperature storage, automation, and ease of shipping/transfer of samples. The device permitted the same data reproducibility as with frozen samples, and yielded higher recovery of nucleic acids. Collection and stabilization of stool microbiome samples with the DNA Genotek collection device, combined with our extraction and WGS, provides a robust, reproducible workflow that enables standardized global collection, storage, and analysis of stool for microbiome studies.

Concepts: DNA, Comparison, Bacteria, Biotechnology, DNA sequencing, Nucleic acid, Standardization, Shotgun sequencing

142

INTRODUCTION    There are no widely accepted standards of diagnosis of sarcoidosis.  OBJECTIVES    The aim of the study was to assess the relative diagnostic yield of endobronchial ultrasound needle aspiration (EBUS-NA) and endoscopic ultrasound needle aspiration (EUS-NA), and to compare them with the standard diagnostic techniques, i.e. endobronchial biopsy (EBB), transbronchial lung biopsy (TBLB), transbronchial needle aspiration (TBNA) and mediastinoscopy.  PATIENTS AND METHODS    A prospective randomized study including consecutive patients with clinical diagnosis of stage I or II sarcoidosis. In all patients EBB, TBLB and TBNA were performed initially. Subsequently, patients were randomized to group A (EBUS-NA) or group B (EUS-NA). Next, a crossover control test was performed: all patients with negative results in group A underwent EUS- NA and all patients with negative results in the group B underwent EBUS-NA. In case of lack of confirmation of sarcoidosis, mediastinoscopy was performed. RESULTS    There were 106 patients enrolled, and 100 were available for the final analysis. Overall sensitivity and accuracy of standard endoscopic methods were both 64%. When analyzing each of the standard endoscopic methods separately, diagnosis was confirmed with EBB in 12 patients (12%), TBLB in 42 patients (42%) and TBNA in 44 patients (44%). The accuracy and sensitivity of each endosonography technique was statistically significantly higher than that of EBB+TBLB+TBNA (P = 0.0112 and 0.0134).  CONCLUSIONS    Sensitivity and accuracy of EBUS-NA and EUS-NA are significantly higher than the standard endoscopic methods (P <0.01). Sensitivity and accuracy of EUS-NA is higher than EBUS-NA, but the difference is not statistically significant.

Concepts: Statistics, Biopsy, Pathology, Type I and type II errors, Medical tests, Standardization, Biostatistics, Statistical theory

55

Single-laboratory studies conducted under highly standardized conditions are the gold standard in preclinical animal research. Using simulations based on 440 preclinical studies across 13 different interventions in animal models of stroke, myocardial infarction, and breast cancer, we compared the accuracy of effect size estimates between single-laboratory and multi-laboratory study designs. Single-laboratory studies generally failed to predict effect size accurately, and larger sample sizes rendered effect size estimates even less accurate. By contrast, multi-laboratory designs including as few as 2 to 4 laboratories increased coverage probability by up to 42 percentage points without a need for larger sample sizes. These findings demonstrate that within-study standardization is a major cause of poor reproducibility. More representative study samples are required to improve the external validity and reproducibility of preclinical animal research and to prevent wasting animals and resources for inconclusive research.

Concepts: Scientific method, Cancer, Sample size, Myocardial infarction, Stroke, Standardization, Statistical power, International Organization for Standardization

32

Dysphagia is estimated to affect ~8% of the world’s population (~590 million people). Texture-modified foods and thickened drinks are commonly used to reduce the risks of choking and aspiration. The International Dysphagia Diet Standardisation Initiative (IDDSI) was founded with the goal of developing globally standardized terminology and definitions for texture-modified foods and liquids applicable to individuals with dysphagia of all ages, in all care settings, and all cultures. A multi-professional volunteer committee developed a dysphagia diet framework through systematic review and stakeholder consultation. First, a survey of existing national terminologies and current practice was conducted, receiving 2050 responses from 33 countries. Respondents included individuals with dysphagia; their caregivers; organizations supporting individuals with dysphagia; healthcare professionals; food service providers; researchers; and industry. The results revealed common use of 3-4 levels of food texture (54 different names) and ≥3 levels of liquid thickness (27 different names). Substantial support was expressed for international standardization. Next, a systematic review regarding the impact of food texture and liquid consistency on swallowing was completed. A meeting was then convened to review data from previous phases, and develop a draft framework. A further international stakeholder survey sought feedback to guide framework refinement; 3190 responses were received from 57 countries. The IDDSI Framework (released in November, 2015) involves a continuum of 8 levels (0-7) identified by numbers, text labels, color codes, definitions, and measurement methods. The IDDSI Framework is recommended for implementation throughout the world.

Concepts: Food, Viscosity, Liquid, Standardization, Dysphagia, International Organization for Standardization, Catering, Thickened fluids

28

An ultrasound assisted extraction method is proposed for the recovery of bioactive glycosides (i.e. crocins and picrocrocin) from Crocus sativus L. dry stigmas using aqueous methanol. Response surface methodology (RSM) was employed to optimize the extraction parameters, namely, the percentage of methanol (%), the duration (min) and the duty cycles (s) of sonication. Optical microscopy, spectrophotometry and RP-HPLC-DAD were employed to follow pros and cons of the process. Additional experiments were conducted to compare recoveries with those under other agitation conditions (e.g. magnetic stirring according to ISO 3632-2 standard). The percentage of methanol, the sonication duration and duty cycles combination that can be recommended as optimum for the recovery of crocins and picrocrocin were 50%, 30min, 0.2s and 0.44%, 30min, 0.6s, respectively. Picrocrocin levels were not influenced dramatically under the optimum conditions for crocins extraction (11±2 instead of 12±1mgkg(-1) dry stigmas, respectively) so that these can be considered optimum for both categories of tested compounds. Ultrasound assisted extraction speeded up further recovery of these precious apocarotenoids. Our findings for extraction conditions are useful for both industrial and analytical applications and should be considered in a forthcoming revision of the ISO 3632-2 technical standard.

Concepts: Standardization, Saffron, Crocus, Safranal, Iridaceae, Picrocrocin, Minoan civilization, International Organization for Standardization

27

Abstract Background: Systems for self-monitoring of blood glucose (SMBG) have to provide accurate and reproducible blood glucose (BG) values in order to ensure adequate therapeutic decisions by people with diabetes. Materials and Methods: Twelve SMBG systems were compared in a standardized manner under controlled laboratory conditions: nine systems were available on the German market and were purchased from a local pharmacy, and three systems were obtained from the manufacturer (two systems were available on the U.S. market, and one system was not yet introduced to the German market). System accuracy was evaluated following DIN EN ISO (International Organization for Standardization) 15197:2003. In addition, measurement reproducibility was assessed following a modified TNO (Netherlands Organization for Applied Scientific Research) procedure. Comparison measurements were performed with either the glucose oxidase method (YSI 2300 STAT Plus™ glucose analyzer; YSI Life Sciences, Yellow Springs, OH) or the hexokinase method (cobas(®) c111; Roche Diagnostics GmbH, Mannheim, Germany) according to the manufacturer’s measurement procedure. Results: The 12 evaluated systems showed between 71.5% and 100% of the measurement results within the required system accuracy limits. Ten systems fulfilled with the evaluated test strip lot minimum accuracy requirements specified by DIN EN ISO 15197:2003. In addition, accuracy limits of the recently published revision ISO 15197:2013 were applied and showed between 54.5% and 100% of the systems' measurement results within the required accuracy limits. Regarding measurement reproducibility, each of the 12 tested systems met the applied performance criteria. Conclusions: In summary, 83% of the systems fulfilled with the evaluated test strip lot minimum system accuracy requirements of DIN EN ISO 15197:2003. Each of the tested systems showed acceptable measurement reproducibility. In order to ensure sufficient measurement quality of each distributed test strip lot, regular evaluations are required.

Concepts: Scientific method, Measurement, Psychometrics, Blood glucose monitoring, Standardization, Glucose meter, International Organization for Standardization, Deutsches Institut für Normung

27

The importance of the complement system in clinical medicine has become evident during the last decades and complement therapeutics has now reached the clinic. Thus, there is an increased interest in and need for assays to evaluate complement activity and dysfunction. Pathologically increased complement activation can indirectly be evaluated by quantification of complement components, but in order to exactly measure such activation, assays for quantification of products formed during activation are required. Progress in this field is hampered by lack of standardization. Therefore, members of the International Complement Standardization Committee, a joint initiative of the International Complement Society and the International Union of Immunological Societies (IUIS), prepared a defined standard for application in assays for complement activation products. We here report on the production and properties of this International Complement Standard #2 (ICS#2). ICS#2 was made from a pool of sera from healthy blood donors (ICS#1) that was activated with a combination of heat-aggregated IgG and zymosan, and subsequently stabilized by adding EDTA and nafamostat mesylate. The protocol was optimized to make the standard applicable in the following activation product assays: C1rs-C1-inhibitor complexes, C4a, C4bc, C4d, Bb, C3bBbP, C3a, C3bc, C3dg, C5a and the soluble terminal C5b-9 complement complex (SC5b-9, TCC). ICS#2 was defined as containing 1000 complement activation units (CAU)/mL for all activation products measured. All activation products were stable after 10 times thawing and freezing and most of the activation products were stable during storage at 4°C for up to 21 days. ICS#2 was produced large-scale and is considered a valuable tool for standardization, calibration and reference control for complement activation assays, providing the necessary prerequisite for quality assessments between complement laboratories.

Concepts: Immune system, Measurement, Complement system, Standardization, Standard, Radiation, Complement component 4, Activation product

27

Guidance about how to practice child neurology has been around for decades. Recently, however, clinical practice guidelines, practice parameters, and standardized clinical assessment and management plans are gaining increasing attention. This overview, written for child neurologists, addresses such issues as the following: what are clinical practice guidelines, why are they needed, how are they created, how should they be created, how well are they accepted and adhered to, what influences acceptance and adherence, do guidelines improve care, do they reduce costs, will they be viewed by courts as the standard of care, how can they be updated and improved, and are there better alternatives?

Concepts: Better, Medicine, Medical ethics, Improve, Neurology, Standardization

26

Experience with Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in a pioneer hospital resulted in a treatment protocol that has become the standard in the Netherlands. Outcome of CRS and HIPEC was reviewed to assure differences between the pioneer phase and the period wherein the Dutch HIPEC protocol was clinically implemented.

Concepts: South Africa, Netherlands, Standardization, Belgium, Dutch people, Dutch language, Afrikaner

26

The clinical hemostasis laboratory is a complex testing arena which employs numerous coagulation assays and spans several different test methodologies. Adding further complexity, these test results are expressed in a wide variety of unique units (concentration, activity, time, percentage, and ratio). Unfortunately, many of these reference values are derived from a local plasma pool or manufacturer’s standards, as there are few established international standards. These three main issues complicate the validation and performance of the coagulation testing. Before an assay can be introduced into clinical use, both analytical and clinical performance parameters must be validated or verified using the standard validation procedures of the laboratory. This article summarizes the initial evaluation and validation processes of the coagulation laboratory, which sometimes can be difficult concepts to implement. A standardized validation protocol is described in this article and, if used, will help to objectively evaluate the assay performance and determine if it meets acceptable laboratory criteria.

Concepts: Coagulation, Validation, Complexity, Test method, Standardization, Standard, Standards, Verification