New solutions to old problems: A practical approach to identify samples with intravenous fluid contamination in clinical laboratories

OBJECTIVES

Contamination with intravenous (IV) fluids is a common cause of specimen rejection or erroneous results in hospitalized patients. Identification of contaminated samples can be difficult. Common measures such as failed delta checks may not be adequately sensitive nor specific. This study aimed to determine detection criteria using commonly ordered tests to identify IV fluid contamination and validate the use of these criteria.

METHODS

Confirmed contaminated and non-contaminated samples were used to identify patterns in laboratory results to develop criteria to detect IV fluid contamination. The proposed criteria were implemented at a tertiary care hospital laboratory to assess performance prospectively for 6 months, and applied to retrospective chemistry results from 3 hospitals and 1 community lab to determine feasibility and flagging rates. The algorithm was also tested at an external institution for transferability.

RESULTS

The proposed algorithm had a positive predictive value of 92 %, negative predictive value of 91 % and overall agreement of 92 % when two or more criteria are met (n = 214). The flagging rates were 0.03 % to 0.07 % for hospital and 0.003 % for community laboratories.

CONCLUSIONS

The proposed algorithm identified true contamination with low false flagging rates in tertiary care urban hospital laboratories. Retrospective and prospective analysis suggest the algorithm is suitable for implementation in clinical laboratories to identify samples with possible IV fluid contamination for further investigation.

Establishing quality indicators for point of care glucose testing: recommendations from the Canadian Society for Clinical Chemists Point of Care Testing and Quality Indicators Special Interest Groups

OBJECTIVES

Monitoring quality indicators (QIs) is an important part of laboratory quality assurance (QA). Here, the Canadian Society of Clinical Chemists (CSCC) Point of Care Testing (POCT) and QI Special Interest Groups describe a process for establishing and monitoring QIs for POCT glucose testing.

METHODS

Key, error prone steps in the POCT glucose testing process were collaboratively mapped out, followed by risk assessment for each step. Steps with the highest risk and ability to detect a non-conformance were chosen for follow-up. These were positive patient identification (PPID) and repeat of critically high glucose measurements. Participating sites were asked to submit aggregate data for these indicators from their site(s) for a one-month period. The PPID QI was also included as part of a national QI monitoring program for which fifty-seven sites submitted data.

RESULTS

The percentage of POCT glucose tests performed without valid PPID ranged from 0-87%. Sites without Admission-Discharge-Transfer (ADT) connectivity to POCT meters were among those with the highest percentage of POCT glucose tests performed without valid PPID. The percentage repeated critically high glucose measurements ranged from 0-50%, indicating low compliance with this recommendation. A high rate of discordance was also noted when critically high POCT glucose measurements were repeated, demonstrating the importance of repeat testing prior to insulin administration.

CONCLUSIONS

Here, a process for establishing these QIs is described, with preliminary data for two QIs chosen from this process. The findings demonstrate the importance of QIs for identification and comparative performance monitoring of non-conformances to improve POCT quality.

Characterization of floating microplastic contamination in the bay of Marseille (French Mediterranean Sea) and its impact on zooplankton and mussels

Microplastics (MPs) were sampled in three seasons from 2016 to 2018 in the Bay of Marseille, northwestern Mediterranean Sea, adjacent to a highly urbanized area. Six sites were selected according to their different characteristics (river mouth, treatment plants, protected marine area). Surface floating MPs were characterized (number, weight, typology and polymer) as was zooplankton. In addition, mussels were submerged and used to investigate ingestion. Finally, a hydrodynamic model was used to improve understanding of dispersion mechanisms. The annual averages of floating MPs values ranged from 39,217 to 514,817 items/km². The MPs collected were mainly fragments principally composed of polyethylene and polypropylene. The mean abundance ratio (MPs/zooplankton) was 0.09. On average 87% of mussel pools were contaminated and ingested 18.73 items/100 g of flesh. Two hydrodynamic patterns were identified: the first retaining the MPs in the harbor, and the second dispersing them outside.

Centralization of multisite reagent lot-to-lot validation for Ortho Clinical Vitros chemistry instruments

OBJECTIVE

Reagent lot-to-lot comparisons are recommended by accreditation bodies to ensure that the performance of each reagent lot meets acceptable standards for quality patient results. The general approach is comprised of performing quality control (QC) and patient comparison between the old and new reagent lots and evaluating against a pre-defined criteria. Reagent lot comparison practices are often variable despite using the same instrument across different laboratories. This is costly, time consuming, and can lead to variability in acceptance criteria. While Clinical & Laboratory Standards Institute (CLSI) has a recommended guideline for reagent lot validation, it is often difficult to execute for small and rural laboratories due to limited resources. Defining the analytes required for detailed validation is important to allocate appropriate resources to ensure quality patient results. The goal of this study was to develop a standardized approach to reagent lot validation and optimize lab resources on Vitros chemistry instruments.

DESIGN AND METHOD

This study consists of a retrospective and prospective analysis of reagent lot changes in dry slide chemistry analyzers (Ortho Clinical Diagnostics Vitros). Two years of retrospective reagent lot comparison data was obtained at a single site. A prospective study was conducted by assessing aliquots of 10 patient sample pools at 9 sites with Vitros analyzers.

RESULTS

Of the 19 chemistry analytes evaluated, albumin, sodium, and total protein showed significant differences between reagent lots and also exceeded the pre-defined acceptance criteria.

CONCLUSION

For these analytes, our recommendations are to perform a comprehensive lot validation with QC and patient samples. A simple lot validation with a reflex approach comprised of initially assaying QC can be adapted for the more stable analytes to allow achieving quality patient result in a resource constraint rural environment.

Identifying sources of error and selecting quality indicators for point of care testing

Objectives

Point of Care Testing (POCT) is a rapidly expanding area of clinical laboratory testing and quality assurance is an important area of focus. Quality indicators (QIs) are a quality management system tool that monitors aspects of the testing process to help meet the challenges associated with maintaining high quality patient safety given the growth in POCT. Alberta aims to formalize the development and use of QIs for POCT.

Design

and Methods: Potential QIs were identified by reviewing both the current standards and guidelines for QIs in POCT, and the research regarding quality and sources of error in POCT. Quality practices and potential sources of error in POCT were identified by: 1) a Canadian national survey on POCT, and 2) direct observation in two local POCT programs.

Results

A proposed selection of QIs in POCT were identified by incorporating the results from these investigations, while considering the unique characteristics of POCT. These QIs monitor the preanalytical, analytical, and post-analytical phases of testing, and support processes.

Conclusions

As POCT volumes and test menu expands, QIs will be a vital tool in monitoring error and maintaining high quality of results. Adoption of formal QIs will support continuous quality improvement and improved patient care.

Volume Fabrication of Quantum Cascade Lasers on 200 mm-CMOS pilot line

The manufacturing cost of quantum cascade lasers is still a major bottleneck for the adoption of this technology for chemical sensing. The integration of Mid-Infrared sources on Si substrate based on CMOS technology paves the way for high-volume low-cost fabrication. Furthermore, the use of Si-based fabrication platform opens the way to the co-integration of QCL Mid-InfraRed sources with SiGe-based waveguides, enabling realization of optical sensors fully integrated on planar substrate. We report here the fabrication and the characterization of DFB-QCL sources using top metal grating approach working at 7.4 µm fully implemented on our 200 mm CMOS pilot line. These QCL featured threshold current density of 2.5 kA/cm² and a linewidth of 0.16 cm⁻¹ with a high fabrication yield. This approach paves the way toward a Mid-InfraRed spectrometer at the silicon chip level.

Dynamic characterization of a periodic microstructured flexural system with rotational inertia

We consider the propagation of waves in a flexural medium composed of massless beams joining a periodic array of elements, elastically supported and possessing mass and rotational inertia. The dispersion properties of the system are determined and the influence and interplay between the dynamic parameters on the structure of the pass and stop bands are analysed in detail. We highlight the existence of three special dynamic regimes corresponding to a low stiffness in the supports and/or low rotational inertia of the masses; to a high stiffness and/or high rotational inertia regime; and to a transition one where dispersion degeneracies are encountered. In the low-frequency regime, a rigorous asymptotic analysis shows that the structure approximates a continuous Rayleigh beam on an elastic foundation. This article is part of the theme issue 'Modelling of dynamic phenomena and localization in structured media (part 1)'.

Seafloor litter from the continental shelf and canyons in French Mediterranean Water: Distribution, typologies and trends

Seafloor litter has been studied both on the continental shelves (by trawling during 24 years) and in canyons (by ROV) of the French Mediterranean sea Water (FMW). On the continental shelf, mean densities range from 49.63 to 289.01 items/km². The most abundant categories were plastic, glass/ceramics, metals and textiles. Trend analysis shows a significant increase in plastic quantities during the study period. Plastics accumulate at all depths, with heavier items being found in deeper areas, while the continental slope-break appears as a clean area. The spatial distribution of litter revealed the influence of geomorphologic factors, anthropic activities, shipping route, river inputs. All the canyons are affected by debris but coastal canyons (Ligurian Sea and Corsica) were more impacted than offshore canyons in the Gulf of Lion. The FMW appears to be highly polluted with regard to values found in other areas, but lower than those observed in the Eastern Mediterranean.

Effects of nuclear factor I phosphorylation on calpastatin (CAST) gene variant expression and subcellular distribution in malignant glioma cells

Malignant glioma (MG) is the most lethal primary brain tumor. In addition to having inherent resistance to radiation treatment and chemotherapy, MG cells are highly infiltrative, rendering focal therapies ineffective. Genes involved in MG cell migration and glial cell differentiation are up-regulated by hypophosphorylated nuclear factor I (NFI), which is dephosphorylated by the phosphatase calcineurin in MG cells. Calcineurin is cleaved and thereby activated by calpain proteases, which are, in turn, inhibited by calpastatin (CAST). Here, we show that the CAST gene is a target of NFI and has NFI-binding sites in its intron 3 region. We also found that NFI-mediated regulation of CAST depends on NFI's phosphorylation state. We noted that occupation of CAST intron 3 by hypophosphorylated NFI results in increased activation of an alternative promoter. This activation resulted in higher levels of CAST transcript variants, leading to increased levels of CAST protein that lacks the N-terminal XL domain. CAST was primarily present in the cytoplasm of NFI-hypophosphorylated MG cells, with a predominantly perinuclear immunostaining pattern. NFI knockdown in NFI-hypophosphorylated MG cells increased CAST levels at the plasma membrane. These results suggest that NFI plays an integral role in the regulation of CAST variants and CAST subcellular distribution. Along with the previous findings indicating that NFI activity is regulated by calcineurin, these results provide a foundation for further investigations into the possibility of regulatory cross-talk between NFI and the CAST/calpain/calcineurin signaling pathway in MG cells.

Treatment with DHA Modifies the Response of MDA-MB-231 Breast Cancer Cells and Tumors from nu/nu Mice to Doxorubicin through Apoptosis and Cell Cycle Arrest

Background

Docosahexaenoic acid (DHA) has been shown to reduce growth of breast cancer cells in vitro and in vivo; it may also benefit the action of cytotoxic cancer drugs. The mechanisms for these observations are not completely understood.

Objectives

We sought to explore how pretreatment of MDA-MB-231 breast cancer cells with DHA alters gene expression with doxorubicin (DOX) treatment and confirm that feeding DHA to tumor-bearing nu/nu mice improves the efficacy of DOX.

Methods

MDA-MB-231 cells were subjected to 4 conditions: a control mixture of 40 μM linoleic and 40 μM oleic acid (OALA), DHA (60 μM plus OALA), OALA DOX (0.41 μM), or DHA DOX (plus OALA) and assessed for effects on viability and function. Female nu/nu mice (6 wk old) bearing MDA-MB-231 tumors were randomly assigned to a nutritionally complete diet (20 g ± 2.8 g DHA/100 g diet) containing a polyunsaturated:saturated fat ratio of 0.5, with or without injections 2 times/wk of 5 mg DOX/kg for 4 wk.

Results

Microarray and protein analysis indicated that DHA DOX cells, compared with OALA DOX, had upregulated expression of apoptosis genes, Caspase-10 (1.3-fold), Caspase-9 (1.4-fold), and Receptor (TNFRSF)-interacting serine-threonine kinase 1 (RIPK1) (1.2-fold), while downregulating cell cycle genes, Cyclin B1 (-2.1-fold), WEE1 (-1.6-fold), and cell division cycle 25 homolog C (CDC25C) (-1.8-fold) (P < 0.05). DHA DOX-treated mice had 50% smaller tumors than control mice (P < 0.05). Analysis of proapoptotic proteins from tumors of DHA DOX mice showed increased Caspase-10 (by 68%) and BH3 interacting domain death agonist (Bid) (by 50%), decreased B-cell CLL/lymphoma 2 (BCL2) (by 24%), and decreased cell cycle proteins Cyclin B1 and Cdc25c (both by 42%), compared with control mice (P < 0.05).

Conclusions

Supplementation with DHA facilitates the action of DOX in MDA-MB-231 cells and in nu/nu mice, which may occur via amplification of the effect of DOX on apoptosis and cell cycle genes.

Nuclear Factor I Represses the Notch Effector HEY1 in Glioblastoma

Glioblastomas (GBMs) are highly aggressive brain tumors with a dismal prognosis. Nuclear factor I (NFI) is a family of transcription factors that controls glial cell differentiation in the developing central nervous system. NFIs have previously been shown to regulate the expression of astrocyte markers such as glial fibrillary acidic protein (GFAP) in both normal brain and GBM cells. We used chromatin immunoprecipitation (ChIP)–on-chip to identify additional NFI targets in GBM cells. Analysis of our ChIP data revealed ~400 putative NFI target genes including an effector of the Notch signaling pathway, HEY1, implicated in the maintenance of neural stem cells. All four NFIs (NFIA, NFIB, NFIC, and NFIX) bind to NFI recognition sites located within 1 kb upstream of the HEY1 transcription site. We further showed that NFI negatively regulates HEY1 expression, with knockdown of all four NFIs in GBM cells resulting in increased HEY1 RNA levels. HEY1 knockdown in GBM cells decreased cell proliferation, increased cell migration, and decreased neurosphere formation. Finally, we found a general correlation between elevated levels of HEY1 and expression of the brain neural stem/progenitor cell marker B-FABP in GBM cell lines. Knockdown of HEY1 resulted in an increase in the RNA levels of the GFAP astrocyte differentiation marker. Overall, our data indicate that HEY1 is negatively regulated by NFI family members and is associated with increased proliferation, decreased migration, and increased stem cell properties in GBM cells.

Traumatic avulsion of the flexor digitorum profundus tendon. Jersey finger, a 29 cases report

Traumatic avulsion of flexor digitorum profundus (jersey finger) is an uncommon injury. Our study aimed to describe functional outcomes of jersey fingers after surgical treatment. From January 2004 to 2014, we performed surgery on 32 patients who had jersey finger. Twenty-six of these patients were male and 6 were female with a mean age of 37.2years (range 16-68). Of the 32 cases, 11 were sports injuries, 16 presented on the ring finger and 13 on the little finger. Using the Leddy and Packer and Smith classifications, 16 of the injuries were type I, 4 were type II, 5 were type III, 7 were type IV. The mean time between injury and surgery was 6.8days (range: 0-32). The surgical techniques used were anchor, pull-out, or an association of both these techniques. Prior to the patient discharge, functional outcomes were evaluated. Twenty-nine patients were evaluated in total and three patients were lost. Of the 29, the average time between surgery and discharge was 36.6months ranging from 4.5 to 118months. According to the Buck-Gramcko classification, six patients had an excellent result, six had a good result, seven had a satisfactory result and ten a poor result. The mean Quick DASH score immediately to prior discharge was 5.66 (range: 0-56.82). Twelve complications were reported on nine patients. No infections were reported. Rapid diagnosis and rapid surgical treatment led to restoration of full range motion.

Wavelength conversion of complex modulation formats in a compact SiGe waveguide

We report a nonlinear signal processing system based on a SiGe waveguide suitable for high spectral efficiency data signals. Four-wave-mixing (FWM)-based wavelength conversion of 10-Gbaud 16-Quadrature amplitude modulated (QAM) and 64-QAM signals is demonstrated with less than -10-dB conversion efficiency (CE), 36-dB idler optical signal-to-noise ratio (OSNR), negligible bit error ratio (BER) penalty and a 3-dB conversion bandwidth exceeding 30nm. The SiGe device was CW-pumped and operated in a passive scheme without giving rise to any two-photon absorption (TPA) effects.

Mid-infrared nonlinear optical response of Si-Ge waveguides with ultra-short optical pulses

We characterize the nonlinear optical response of low loss Si(0.6)Ge(0.4) / Si waveguides in the mid-infrared between 3.3 μm and 4 μm using femtosecond optical pulses. We estimate the three and four-photon absorption coefficients as well as the Kerr nonlinear refractive index from the experimental measurements. The effect of multiphoton absorption on the optical nonlinear Kerr response is evaluated and the nonlinear figure of merit estimated providing some guidelines for designing nonlinear optical devices in the mid-IR. Finally, we compare the impact of free-carrier absorption at mid-infrared wavelengths versus near-infrared wavelengths for these ultra-short pulses.

[Syphilis in Montpellier, France, from 2002 to 2011: Survey in a free hospital screening centre for venereal disease and in the dermatology unit of a regional public hospital]

BACKGROUND

In a context of resurgent syphilis in France since 2000, we conducted a retrospective study in two different centres in Montpellier, France: the dermatology department of a public hospital and an anonymous and free centre for provision of information, diagnosis and treatment of venereal diseases (CDAG-CIDDIST).

PATIENTS AND METHODS

All patients with syphilis seen from January 2002 to December 2011 were included with the collaboration of the National Health Institute (InVS) and the Bacteriology Department of the public hospital. Epidemiology, clinical presentation, serological data, and treatment and monitoring data for up to 2 years were recorded.

RESULTS

One hundred and seventy-five cases of syphilis were diagnosed: 154 at the CDAG and 21 at the dermatology unit. Ninety-six percent of cases concerned men with a median age of 36 years. Eighty-two percent of these cases involved men having sex with men (MSM). Forty-nine percent of cases were diagnosed in the secondary stage, 22% in the primary stage and 28% in the latent stage. The treatment administered in the majority of cases (73%) was benzathine-penicillin G. The numbers of patients showing incomplete follow-up were equal at both centres, with 31 patients (17.7%) failing to attend the follow-up visit. A decrease of at least 2 dilutions in VDRL score occurred in the year following treatment for 93 of 103 patients (90%). Patients managed at the dermatology department were older than their counterparts managed at the CDAG and exhibited more frequent cutaneous eruptions (58% vs. 3%, P<0.0001) but were less frequently bisexual. However, no significant differences were seen concerning sex and associated infections (hepatitis, gonococcal infection, HPV or herpes).

DISCUSSION

Syphilis is on the rise, especially in the MSM population. The epidemiological characteristics of our cohort were consistent with those of other Western European countries. Although the reasons for consultation differed between CDAG/CIDDIST and the dermatology department, the two centres are complementary. Benzathine-penicillin G was the most commonly used treatment, in accordance with the recommendations. Measures must be introduced to improve patient monitoring without compromising anonymity.