Variation in Laboratory Reporting of Haemolysis – a Need for Harmonisation

Aim

The purpose of this survey was to determine the cut-offs being used by Australian laboratories using their instrument’s Haemolysis Index (HI), whether these cut-offs vary, and at what level of haemolysis (or haemolysis index) did laboratories stop reporting one or more analytes. This was done in response to the large numbers of haemolysed samples reported in the RCPAQAP Key Incident Monitoring and Management System External Quality Assurance program (KIMMS EQA) and lack of information in the literature at the time regarding what to do once a haemolysed sample was identified. As it was known from discussions with laboratory personnel that different instruments reported their HI differently, we asked for the results to be provided in g/L free haemoglobin.

Method

An electronic survey was conducted with participants enrolled in the RCPA Quality Assurance Programs with a total of 68 laboratories responding to this survey. Some questions attracted a lower level of response.

Results

The responses showed a poor understanding of the relationship between HI units and haemoglobin concentration. There was wide variation in the way HI results were reported and thus comparing cut-off values for reporting specific analytes based on the HI was impossible to determine.

Conclusion

There is a need to harmonise the way laboratories report analytes in the presence of haemolysis. This would involve adopting a uniform definition of HI and a protocol for laboratories to confirm for themselves the level of HI at which each analyte is no longer reported, as this is method dependent and so will vary from laboratory to laboratory.     

Carbapenem Non-Susceptible Enterobacteriaceae in Quebec,Canada: Results of a Laboratory Surveillance Program (2010–2012)

The emergence and spread of carbapenemase-producing Enterobacteriaceae (CPE) represent a major public health concern because these bacteria are usually extensively resistant to most antibiotics. In order to evaluate their dissemination in Quebec, a surveillance program was introduced in 2010. We report the molecular and epidemiological profiles of CPE isolates collected. Between August 2010 and December 2012, a total of 742 non-duplicate isolates non-susceptible to carbapenems were analysed. AmpC β-lactamase and metallo-β-lactamase production were detected by Etest and carbapenemase production by the modified Hodge test (MHT). Antibiotic susceptibility profiles were determined using broth microdilution or Etest. Clonality of Klebsiella pneumoniae carbapenemase (KPC) strains was analyzed by pulsed-field gel electrophoresis (PFGE). The presence of genes encoding carbapenemases as well as other β-lactamases was detected using PCR. Of the 742 isolates tested, 169 (22.8%) were CPE. Of these 169 isolates, 151 (89.3%) harboured a bla _KPC gene while the remaining isolates carried bla _SME (n = 9), bla _OXA-48 (n = 5), bla _NDM (n = 3), and bla _NMC (n = 1) genes. Among the 93 KPC strains presenting with a unique pattern (unique PFGE pattern and/or unique antibiotics susceptibility profile), 99% were resistant to ertapenem, 95% to imipenem, 87% to meropenem, 97% to aztreonam, 31% to colistin and 2% to tigecycline. In 19 patients, 2 to 5 KPC strains from different species or with a different PFGE pattern were isolated. CPE strains were present in the province of Quebec with the majority of strains harbouring KPC. Alternately, SME, OXA-48 and NMC containing strains were rarely found.     

Loop-Mediated Isothermal Amplification for Laboratory Confirmation of Buruli Ulcer Disease—Towards a Point-of-Care Test

Background

As the major burden of Buruli ulcer disease (BUD) occurs in remote rural areas, development of point-of-care (POC) tests is considered a research priority to bring diagnostic services closer to the patients. Loop-mediated isothermal amplification (LAMP), a simple, robust and cost-effective technology, has been selected as a promising POC test candidate. Three BUD-specific LAMP assays are available to date, but various technical challenges still hamper decentralized application. To overcome the requirement of cold-chains for transport and storage of reagents, the aim of this study was to establish a dry-reagent-based LAMP assay (DRB-LAMP) employing lyophilized reagents.

Methodology/Principal Findings

Following the design of an IS2404 based conventional LAMP (cLAMP) assay suitable to apply lyophilized reagents, a lyophylization protocol for the DRB-LAMP format was developed. Clinical performance of cLAMP was validated through testing of 140 clinical samples from 91 suspected BUD cases by routine assays, i.e. IS2404 dry-reagent-based (DRB) PCR, conventional IS2404 PCR (cPCR), IS2404 qPCR, compared to cLAMP. Whereas qPCR rendered an additional 10% of confirmed cases and samples respectively, case confirmation and positivity rates of DRB-PCR or cPCR (64.84% and 56.43%; 100% concordant results in both assays) and cLAMP (62.64% and 52.86%) were comparable and there was no significant difference between the sensitivity of the assays (DRB PCR and cPCR, 86.76%; cLAMP, 83.82%). Likewise, sensitivity of cLAMP (95.83%) and DRB-LAMP (91.67%) were comparable as determined on a set of 24 samples tested positive in all routine assays.

Conclusions/Significance

Both LAMP formats constitute equivalent alternatives to conventional PCR techniques. Provided the envisaged availability of field friendly DNA extraction formats, both assays are suitable for decentralized laboratory confirmation of BUD, whereby DRB-LAMP scores with the additional advantage of not requiring cold-chains. As validation of the assays was conducted in a third-level laboratory environment, field based evaluation trials are necessary to determine the clinical performance at peripheral health care level.     

Do Movement Patterns Differ Between Laboratory and Field Suction Feeding Behaviors in a Mexican Cichlid?

Synopsis We analyzed feeding behavior of individuals of Herichthys minckleyi, the Cuatro Ciénegas cichlid, under laboratory conditions and freely behaving in their natural environment using high-speed video imaging. In a multivariate analysis of suction feeding behaviors there was no clear grouping of feeding events based on the environment, which suggests that most of the variability in the data was unrelated to differences between lab and field behaviors. In fact, the variability within an environment was far greater than the variability between the two environments. These results suggest that laboratory studies can accurately describe the kinematics of behaviors seen in the field. However, although lab based studies can quantify behaviors seen in the field, natural habitats are complex and provide individuals with the opportunity to exploit a wide range of food types and microhabitats, which may elicit behaviors not observed in the laboratory. However, feeding behaviors observed in the lab are representative of frequently used feeding behaviors in the field, at least for this species. Thus, we suggest that laboratory studies of feeding behavior, particularly those that test biomechanical or performance-based hypotheses can be extrapolated to natural environments.     

Evans Blue as a Simple Method to Discriminate Mosquitoes’ Feeding Choice on Small Laboratory Animals

Background

Temperature, humidity, vision, and particularly odor, are external cues that play essential roles to mosquito blood feeding and oviposition. Entomological and behavioral studies employ well-established methods to evaluate mosquito attraction or repellency and to identify the source of the blood meal. Despite the efficacy of such methods, the costs involved in the production or acquisition of all parts, components and the chemical reagents involved are unaffordable for most researchers from poor countries. Thus, a simple and relatively low-cost method capable of evaluating mosquito preferences and the blood volume ingested is desirable.

Principal Findings

By using Evans blue (EB) vital dye and few standard laboratory supplies, we developed and validated a system capable of evaluating mosquito’s choice between two different host sources of blood. EB-injected and PBS-injected mice submitted to a number of situations were placed side by side on the top of a rounded recipient covered with tulle fabric and containing Aedes aegypti mosquitoes. Homogenates from engorged mosquitoes clearly revealed the blood source (EB- or PBS-injected host), either visually or spectrometrically. This method was able to estimate the number of engorded mosquitoes, the volume of blood ingested, the efficacy of a commercial repellent and the attractant effects of black color and human sweat.

Significance

Despite the obvious limitations due to its simplicity and to the dependence of a live source of blood, the present method can be used to assess a number of host variables (diet, aging, immunity, etc) and optimized for several aspects of mosquito blood feeding and vector-host interactions. Thus, it is proposed as an alternative to field studies, and it could be used for initial screenings of chemical compound candidates for repellents or attractants, since it replicates natural conditions of exposure to mosquitoes in a laboratory environment.     

Individual Normal Laboratory Values—Preliminary Observations

A brief and preliminary outline is given describing a consecutive and continuing study of laboratory blood values of only 12 of 48 “normal healthy” subjects with only a few values given. The major emphasis is that of obtaining blood from each subject over a 12-week period to be repeated annually in order to determine individual values and in obtaining a chemical identification of each subject with the anticipation that more information will be available concerning the meaning and limiting parameters of “normal” biologic values. Such a study is made available through the application of modern advances in automation and the wide use of computers. It seems likely that some disorders can be discovered before clinically apparent, with the hope that consequent preventive measures and therapy may be more effective.The few values presented represent only a small part of those yet to be obtained. Much more work is needed in this study of normal values whose parameters must be further defined.     

Complete Isolation System for Laboratory Infectious Animal

Contents:Duringthe development of biological medical science,a great number of research experiments are carried out andthe various infectious animal experiments are necessary part of them.For lab animal experiments,it is necessary tochoose proper isolation equipments accordingto experiment hazardlevels.1.FunctionsAnimal isolation systemare used broadlyin laboratory research,pharmaceuticals and medical areas.The isolationsystemhas become excellent equipmentsin animal breeding,disease diagnosis…     

Here a virus, there a virus, everywhere the same virus?

There are an estimated 10(31) viruses on Earth, most of which are phages that infect bacteria. Metagenomic analyses have shown that environmental viral communities are incredibly diverse. There are an estimated 5000 viral genotypes in 200 liters of seawater and possibly a million different viral genotypes in one kilogram of marine sediment. By contrast, some culturing and molecular studies have found that viruses move between different biomes. Together, these findings suggest that viral diversity could be high on a local scale but relatively limited globally. Also, by moving between environments, viruses can facilitate horizontal gene transfer.     

Sociologists,Archbishops, and ‘making a verb of a noun’

ABSTRACT

Contemporary discussion about race has a tendency to set off out without first checking the rear view mirror. In Theories of Race and Ethnicity: Contemporary Debates and Perspectives, in contrast, Murji and Solomos identify what has and has not been covered, and so appeal at the outset for a ‘more sustained’ account of changing research agendas of race and ethnic relations. Taken as a whole, the collection allows the editors to contemplate ‘what factors explain the mobilizing power of ideas about race and ethnicity in the contemporary environment?' and whether indeed ‘it is the “real” rather than race that should be placed in quotation marks’.     

TREPONEMAL SEROLOGIC TESTS—Experiences of the Bacteriology Laboratory,California State Department of Public Health

In a study of the relationship of clinical impression regarding syphilis and age, sex and pregnancy status to treponemal serologic test reactivity, it was noted that in diagnostic “problem cases” the standard lipid serologic test titers did not differentiate between syphilitic and biologic false positive reactors. Preliminary data indicated that heroin addiction may be a source of biologic false reactions and that pregnant women with standard serologic test reactivity have a lower treponemal reactivity rate than other women with lipid serologic reactivity.     

Beta-carotene supplementation: a good thing, a bad thing, or nothing?

Available data from several completed large-scale randomized trials indicate that beta-carotene supplementation for durations up to 12 years has no overall benefit in well-nourished populations on the incidence of cardiovascular disease or the middle-to-late stages of carcinogenesis. Several important questions, however, remain unanswered. The post-trial follow-up of completed trials, together with the results of several ongoing trials of beta-carotene supplementation, will contribute reliable information to the totality of evidence from basic research, animal studies, observational epidemiologic studies, and completed trials, thus allowing more rational clinical decisions for individual patients and policy decisions for the health of the general public.     

Aurora kinases, aneuploidy and cancer, a coincidence or a real link?

As Aurora kinases are overexpressed in a large number of cancers, and ectopic expression of Aurora generates polyploid cells containing multiple centrosomes, it has been tempting to suggest that Aurora overexpression provokes genetic instability underlying the tumorigenesis. However, examination of the evidence suggests a more complex relationship. Overexpression of Aurora-A readily transforms rat-1 and NIH3T3 cells, but not primary cells, whereas overexpression of Aurora-B induces metastasis after implantation of tumors in nude mice. Why do polyploid cells containing abnormal centrosome numbers induced by Aurora not get eliminated at cell-cycle checkpoints? Does this phenotype determine the origin of cancer or does it only promote tumor progression? Would drugs against Aurora family members be of any help for cancer treatment? These and related questions are addressed in this review (which is part of the Chromosome Segregation and Aneuploidy series).