Improving the sensitivity of myelin oligodendrocyte glycoprotein-antibody testing: exclusive or predominant MOG-IgG3 seropositivity-a potential diagnostic pitfall in patients with MOG-EM/MOGAD

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated encephalomyelitis (MOG-EM; also termed MOG antibody-associated disease, MOGAD) is the most important differential diagnosis of both multiple sclerosis and neuromyelitis optica spectrum disorders. A recent proposal for new diagnostic criteria for MOG-EM/MOGAD explicitly recommends the use of immunoglobulin G subclass 1 (IgG1)- or IgG crystallizable fragment (Fc) region-specific assays and allows the use of heavy-and-light-chain-(H+L) specific assays for detecting MOG-IgG. By contrast, the utility of MOG-IgG3-specific testing has not been systematically evaluated.

OBJECTIVE

To assess whether the use of MOG-IgG3-specific testing can improve the sensitivity of MOG-IgG testing.

METHODS

Re-testing of 22 patients with a definite diagnosis of MOG-EM/MOGAD and clearly positive MOG-IgG status initially but negative or equivocal results in H+L- or Fc-specific routine assays later in the disease course (i.e. patients with spontaneous or treatment-driven seroreversion).

RESULTS

In accordance with previous studies that had used MOG-IgG1-specific assays, IgG subclass-specific testing yielded a higher sensitivity than testing by non-subclass-specific assays. Using subclass-specific secondary antibodies, 26/27 supposedly seroreverted samples were still clearly positive for MOG-IgG, with MOG-IgG1 being the most frequently detected subclass (25/27 [93%] samples). However, also MOG-IgG3 was detected in 14/27 (52%) samples (from 12/22 [55%] patients). Most strikingly, MOG-IgG3 was the predominant subclass in 8/27 (30%) samples (from 7/22 [32%] patients), with no unequivocal MOG-IgG1 signal in 2 and only a very weak concomitant MOG-IgG1 signal in the other six samples. By contrast, no significant MOG-IgG3 reactivity was seen in 60 control samples (from 42 healthy individuals and 18 patients with MS). Of note, MOG-IgG3 was also detected in the only patient in our cohort previously diagnosed with MOG-IgA+/IgG- MOG-EM/MOGAD, a recently described new disease subvariant. MOG-IgA and MOG-IgM were negative in all other patients tested.

CONCLUSIONS

In some patients with MOG-EM/MOGAD, MOG-IgG is either exclusively or predominantly MOG-IgG3. Thus, the use of IgG1-specific assays might only partly overcome the current limitations of MOG-IgG testing and-just like H+L- and Fcγ-specific testing-might overlook some genuinely seropositive patients. This would have potentially significant consequences for the management of patients with MOG-EM/MOGAD. Given that IgG3 chiefly detects proteins and is a strong activator of complement and other effector mechanisms, MOG-IgG3 may be involved in the immunopathogenesis of MOG-EM/MOGAD. Studies on the frequency and dynamics as well as the clinical and therapeutic significance of MOG-IgG3 seropositivity are warranted.

Finding new analgesics: Computational pharmacology faces drug discovery challenges

Despite the worldwide prevalence and huge burden of pain, pain is an undertreated phenomenon. Currently used analgesics have several limitations regarding their efficacy and safety. The discovery of analgesics possessing a novel mechanism of action has faced multiple challenges, including a limited understanding of biological processes underpinning pain and analgesia and poor animal-to-human translation. Computational pharmacology is currently employed to face these challenges. In this review, we discuss the theory, methods, and applications of computational pharmacology in pain research. Computational pharmacology encompasses a wide variety of theoretical concepts and practical methodological approaches, with the overall aim of gaining biological insight through data acquisition and analysis. Data are acquired from patients or animal models with pain or analgesic treatment, at different levels of biological organization (molecular, cellular, physiological, and behavioral). Distinct methodological algorithms can then be used to analyze and integrate data. This helps to facilitate the identification of biological molecules and processes associated with pain phenotype, build quantitative models of pain signaling, and extract translatable features between humans and animals. However, computational pharmacology has several limitations, and its predictions can provide false positive and negative findings. Therefore, computational predictions are required to be validated experimentally before drawing solid conclusions. In this review, we discuss several case study examples of combining and integrating computational tools with experimental pain research tools to meet drug discovery challenges.

Melatonin facts: Melatonin lacks immuno-inflammation boosting capacities at the molecular and cellular levels

Among the properties melatonin is claimed to possess, are the immuno-inflammation inductive capacities that would be responsible of some of the paramount of activities melatonin is reported to have in most of the human pathological conditions. In the present paper, we measured the effect of melatonin on established cellular models of immuno-inflammation, and found none. The discrepancies are discussed, especially because those properties are reported at pharmacological concentration (1 μM and beyond) at which the melatonin receptors are desensitized by internalization, leading to putative non-receptor-dependent mechanism of action.

Consensus on criteria for acromegaly diagnosis and remission

PURPOSE

The 14th Acromegaly Consensus Conference was convened to consider biochemical criteria for acromegaly diagnosis and evaluation of therapeutic efficacy.

METHODS

Fifty-six acromegaly experts from 16 countries reviewed and discussed current evidence focused on biochemical assays; criteria for diagnosis and the role of imaging, pathology, and clinical assessments; consequences of diagnostic delay; criteria for remission and recommendations for follow up; and the value of assessment and monitoring in defining disease progression, selecting appropriate treatments, and maximizing patient outcomes.

RESULTS

In a patient with typical acromegaly features, insulin-like growth factor (IGF)-I > 1.3 times the upper limit of normal for age confirms the diagnosis. Random growth hormone (GH) measured after overnight fasting may be useful for informing prognosis, but is not required for diagnosis. For patients with equivocal results, IGF-I measurements using the same validated assay can be repeated, and oral glucose tolerance testing might also be useful. Although biochemical remission is the primary assessment of treatment outcome, biochemical findings should be interpreted within the clinical context of acromegaly. Follow up assessments should consider biochemical evaluation of treatment effectiveness, imaging studies evaluating residual/recurrent adenoma mass, and clinical signs and symptoms of acromegaly, its complications, and comorbidities. Referral to a multidisciplinary pituitary center should be considered for patients with equivocal biochemical, pathology, or imaging findings at diagnosis, and for patients insufficiently responsive to standard treatment approaches.

CONCLUSION

Consensus recommendations highlight new understandings of disordered GH and IGF-I in patients with acromegaly and the importance of expert management for this rare disease.

Serum and cerebrospinal fluid neurofilament light chains measured by SIMOA™, Ella™, and Lumipulse™ in multiple sclerosis naïve patients

BACKGROUND

Neurofilament light chains (NfL) are cytoskeletal biomarkers of axonal damage, about 40-fold higher in cerebrospinal fluid (CSF) compared to serum, and requiring ultrasensitive techniques to be measured in this latter fluid.

OBJECTIVES

To compare CSF and serum NfL levels in multiple sclerosis (MS) patients using different platforms.

METHODS

60 newly diagnosed relapsing-remitting MS patients (38 females; median age: 36.5 years, range: 15-60) were enrolled before steroid or disease-modifying treatments. CSF and serum NfL were measured with: the commercial Ella™ microfluidic platform (Bio-Techne), the Lumipulse™ Chemiluminescent Enzyme ImmunoAssay (Fujirebio), and the SIMOA™ on the SR-X instrument using NF-light assays (Quanterix).

RESULTS

CSF and serum NfL absolute levels strongly correlated between assays, although being more elevated with Ella™. Passing-Bablok regression showed high agreement in measuring CSF NfL between assays (with greater proportional difference using Ella™), and very high agreement for serum comparing SIMOA™ and Lumipulse™. Similarly, the Bland-Altman comparison evidenced lower biases for Lumipulse™ for both fluids.

CONCLUSIONS

CSF and serum NfL in naïve MS patients are reliably measured with all assays. Although not interchangeable, SIMOA™ and Lumipulse™ showed high agreement for serum and CSF values.

Development and validation of an expanded panel of progestins using liquid chromatography-tandem triple quadrupole mass spectrometry to monitor protocol compliance in hormonal contraceptive pharmacokinetic/pharmacodynamic studies

We developed and validated the use of ultra-high-performance liquid chromatography-heated electrospray ionization-tandem triple quadrupole mass spectrometry to simultaneously analyze serum concentrations of ethinylestradiol, dienogest, norelgestromin, norethindrone, gestodene, levonorgestrel, etonogestrel, segesterone acetate, medroxyprogesterone acetate, and drospirenone. The calibration range for all targets was 0.009-10 ng/mL, with lower limit of quantification of 0.009 ng/mL for all analytes except gestodene (0.019 ng/mL). We used our assay to check compliance among participants in a clinical trial, confirmed the use of drospirenone in 11 of 13 study participants, and evidence of noncompliant progestins in 2 (levonorgestrel = 1, norethindrone = 1). We conclude that this approach provides an accurate method to check protocol compliance in contraceptive clinical trials. IMPLICATIONS: The availability of a liquid chromatography-tandem triple quadrupole mass spectrometry multiprogestin analysis panel for simultaneous evaluation of the most common contraceptive steroids approved worldwide could improve monitoring of compliance and protocol adherence in clinical trials.

Hormone receptor activities of complex mixtures of known and suspect chemicals in personal silicone wristband samplers worn in office buildings

Humans are exposed to increasingly complex mixtures of hormone-disrupting chemicals from a variety of sources, yet, traditional research methods only evaluate a small number of chemicals at a time. We aimed to advance novel methods to investigate exposures to complex chemical mixtures. Silicone wristbands were worn by 243 office workers in the USA, UK, China, and India during four work shifts. We analyzed extracts of the wristbands for: 1) 99 known (targeted) chemicals; 2) 1000+ unknown chemical features, tentatively identified through suspect screening; and 3) total hormonal activities towards estrogen (ER), androgen (AR), and thyroid hormone (TR) receptors in human cell assays. We evaluated associations of chemicals with hormonal activities using Bayesian kernel machine regression models, separately for targeted versus suspect chemicals (with detection ≥50%). Every wristband exhibited hormonal activity towards at least one receptor: 99% antagonized TR, 96% antagonized AR, and 58% agonized ER. Compared to men, women were exposed to mixtures that were more estrogenic (180% higher, adjusted for country, age, and skin oil abundance in wristband), anti-androgenic (110% higher), and complex (median 836 detected chemical features versus 780). Adjusted models showed strong associations of jointly increasing chemical concentrations with higher hormonal activities. Several targeted and suspect chemicals were important co-drivers of overall mixture effects, including chemicals used as plasticizers, fragrance, sunscreen, pesticides, and from other or unknown sources. This study highlights the role of personal care products and building microenvironments in hormone-disrupting exposures, and the substantial contribution of chemicals not often identifiable or well-understood to those exposures.

A systematic quality evaluation and review of nanomaterial genotoxicity studies: a regulatory perspective

The number of publications in the field of nanogenotoxicology and the amount of genotoxicity data on nanomaterials (NMs) in several databases generated by European Union (EU) funded projects have increased during the last decade. In parallel, large research efforts have contributed to both our understanding of key physico-chemical (PC) parameters regarding NM characterization as well as the limitations of toxicological assays originally designed for soluble chemicals. Hence, it is becoming increasingly clear that not all of these data are reliable or relevant from the regulatory perspective. The aim of this systematic review is to investigate the extent of studies on genotoxicity of NMs that can be considered reliable and relevant by current standards and bring focus to what is needed for a study to be useful from the regulatory point of view. Due to the vast number of studies available, we chose to limit our search to two large groups, which have raised substantial interest in recent years: nanofibers (including nanotubes) and metal-containing nanoparticles. Focusing on peer-reviewed publications, we evaluated the completeness of PC characterization of the tested NMs, documentation of the model system, study design, and results according to the quality assessment approach developed in the EU FP-7 GUIDEnano project. Further, building on recently published recommendations for best practices in nanogenotoxicology research, we created a set of criteria that address assay-specific reliability and relevance for risk assessment purposes. Articles were then reviewed, the qualifying publications discussed, and the most common shortcomings in NM genotoxicity studies highlighted. Moreover, several EU projects under the FP7 and H2020 framework set the aim to collectively feed the information they produced into the eNanoMapper database. As a result, and over the years, the eNanoMapper database has been extended with data of various quality depending on the existing knowledge at the time of entry. These activities are highly relevant since negative results are often not published. Here, we have reviewed the NanoInformaTIX instance under the eNanoMapper database, which hosts data from nine EU initiatives. We evaluated the data quality and the feasibility of use of the data from a regulatory perspective for each experimental entry.

Validation of double freezing protocol for Beetal buck (Capra hircus) spermatozoa

The study aimed to validate the double versus single freezing protocol for Beetal buck (Capra hircus) spermatozoa in tris-citric acid (TCA) based extender both in terms of quality and fertilization potential. Computer-assisted sperm motion and kinematic (CASA) variables i.e., total (%), and progressive motilities (TM and PM, %), and rapid velocity (RV, %), average path (VAP, μm/s), straight line (VSL, μm/s), and curved line velocities (VCL, μm/s), straightness, (VSL/VAP, %), and linearity, (VSL/VCL, %) as well as supra-vital plasma membrane integrity (SV-PMI, %), mitochondrial membrane potential (MMP, %), viable / intact acrosome (V-IACR, %) and DNA integrity (DNA-I, %) had significantly greater values (P<0.05) during single freeze-thawing as compared to the double freeze-thawing at 0, 30, 90, 150 and 210 days, respectively. All CASA and other assays alone did not show significant differences (P>0.05) between both freeze-thaw cycles at all treatment durations, respectively. No statistical significance (P>0.05) was observed for the in vivo fertility between single (n = 84/141 = 59.72%) and double freeze-thawing (n =72/136 = 52.90%) cycles, respectively. In conclusion, sperm motion, kinematics, plasma membrane, acrosome, mitochondria and DNA integrities and in vivo fertility are acceptable after the double freezing protocol despite being lower than after one freeze cycle in Beetal buck (Capra hircus).

Role of the pathologist in the diagnosis of autoimmune encephalitis

Autoimmune encephalitis is a group of non-infectious immune-mediated inflammatory disorders manifesting with epilepsy and encephalitis syndromes that are associated with autoantibodies in the serum and/or cerebrospinal fluid (CSF). Pathogenic autoantibodies have been discovered against intracellular onconeural antigens, surface neuronal, or synaptic antigens with distinctive pathogenesis that underlie differences in response to immunotherapy. The onconeural antigens incite cytotoxic T-cell-mediated neuronal destruction, whereas surface antigens trigger direct damage by autoantibodies via complement mediated pathways, and hence respond well to immunomodulatory therapy, in contrast to poor response in the former. Neuroimaging, electroencephalogram, and CSF findings being non-specific, detection of autoantibodies is essential for a confirmatory diagnosis. Detection methods available include tissue-based assay, cell-based assays, immunoblot, cell culture, flow cytometry, and enzyme-linked immunosorbent assays. In this review, we discuss the various testing modalities available for onconeural and cell surface antibodies, their sensitivity and specificity and the emerging role of the pathologist in the diagnosis of autoimmune encephalitis. Early diagnosis is crucial for instituting treatment and preventing morbidity and mortality.

Evaluation of in vitro methods of anthelmintic efficacy testing against Ascaridia galli

To investigate methods for in vitro assessment of anthelmintic efficacy against the chicken nematode Ascaridia galli this study firstly evaluated sample preparation methods including recovery of eggs from excreta using different flotation fluids and induced larval hatching by the deshelling-centrifugation method and the glass-bead method with or without bile. It then evaluated two in vitro assays, the in-ovo larval development assay (LDA) and larval migration inhibition assay (LMIA), for anthelmintic efficacy testing against A. galli using fresh eggs and artificially hatched larvae, respectively. Four anthelmintics, thiabendazole (TBZ), fenbendazole (FBZ), levamisole (LEV) and piperazine (PIP) were employed using an A. galli isolate of known susceptibility. The results suggested that the LDA and LMIA could successfully be used to generate concentration response curves for the tested drugs. The LDA provided EC50 values for inhibition of egg embryonation of 0.084 and 0.071 μg/ml for TBZ and FBZ, respectively. In the LMIA, the values of effective concentration (EC50) of TBZ, FBZ, LEV and PIP were 105.9, 6.32, 349.9 and 6.78 × 107 nM, respectively. For such in vitro studies, a saturated sugar solution showed high egg recovery efficiency (67.8%) and yielded eggs of the highest morphological quality (98.1%) and subsequent developmental ability (93.3%). The larval hatching assays evaluated did not differ in hatching efficiency but the deshelling-centrifugation method yielded larvae that had slightly better survival rates. For final standardization of these tests and establishment of EC50 reference values, tests using isolates of A. galli of defined resistance status need to be performed.

Breast cancer resistance to chemotherapy: When should we suspect it and how can we prevent it?

Chemotherapy is an essential treatment for breast cancer, inducing cancer cell death. However, chemoresistance is a problem that limits the effectiveness of chemotherapy. Many factors influence chemoresistance, including drug inactivation, changes in drug targets, overexpression of ABC transporters, epithelial-to-mesenchymal transitions, apoptotic dysregulation, and cancer stem cells. The effectiveness of chemotherapy can be assessed clinically and pathologically. Clinical response evaluation is based on physical examination or imaging (mammography, ultrasonography, computed tomography scan, or magnetic resonance imaging) and includes tumor size changes after chemotherapy. Pathological response evaluation is a method based on tumor residues in histopathological preparations. We should be suspicious of chemoresistance if there are no significant changes clinically according to the Response Evaluation Criteria in Solid Tumors and World Health Organization criteria or pathological changes according to the Miller and Payne criteria, especially after 2–3 cycles of chemotherapy treatments. Chemoresistance is mostly detected after the administration of chemotherapy drugs. No reliable parameters or biomarkers can predict chemotherapy responses appropriately and effectively. Well-known parameters such as cancer type, grade, subtype, estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, Ki-67, and MDR-1/P-gP have been used for selecting chemotherapy regimens. Some new methods for predicting chemoresistance include chemosensitivity and chemoresistance assays, multigene expressions, and positron emission tomography assays. The latest approaches are based on evaluation of molecular processes and the metabolic activity of cancer cells. Some methods for preventing chemoresistance include using the right regimen, using some combination of chemotherapy methods, conducting adequate monitoring, and using drugs that could prevent the emergence of multidrug resistance.

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Chemotherapy is an essential treatment in the management of breast cancer.

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Chemotherapy is carried out based on the selection of regimens for the specific individual and tumor characteristics.

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Combination therapy, monitoring, and evaluation are used to prevent chemoresistance.

Reliable generation of glial enriched progenitors from human fibroblast-derived iPSCs

White matter stroke (WMS) occurs as small infarcts in deep penetrating blood vessels in the brain and affects the regions of the brain that carry connections, termed the subcortical white matter. WMS progresses over years and has devastating clinical consequences. Unlike large grey matter strokes, WMS disrupts the axonal architecture of the brain and depletes astrocytes, oligodendrocyte lineage cells, axons and myelinating cells, resulting in abnormalities of gait and executive function. An astrocytic cell-based therapy is positioned as a strong therapeutic candidate after WMS. In this study we report, the reliable generation of a novel stem cell-based therapeutic product, glial enriched progenitors (GEPs) derived from human induced pluripotent stem cells (hiPSCs). By transient treatment of hiPSC derived neural progenitors (hiPSC-NPCs) with the small molecule deferoxamine, a prolyl hydroxylase inhibitor, for three days hiPSC-NPCs become permanently biased towards an astrocytic fate, producing hiPSC-GEPs. In preparation for clinical application, we have developed qualification assays to ensure identity, safety, purity, and viability of the cells prior to manufacture. Using tailored q-RT-PCR-based assays, we have demonstrated the lack of pluripotency in our final therapeutic candidate cells (hiPSC-GEPs) and we have identified the unique genetic profile of hiPSC-GEPs that is clearly distinct from the parent lines, hiPSCs and iPSC-NPCs. After completion of the viability assay, we have stablished the therapeutic window of use for hiPSC-GEPs in future clinical applications (7 h). Lastly, we were able to reliably and consistently produce a safe therapeutic final product negative for contamination by any human or murine viral pathogens, selected bacteria, common laboratory mycoplasmas, growth of any aerobes, anaerobes, yeast, or fungi and 100 times less endotoxin levels than the maximum acceptable value. This study demonstrates the reliable and safe generation of patient derived hiPSC-GEPs that are clinically ready as a cell-based therapeutic approach for WMS.

Markers of Immune Function in Heart Transplantation: Implications for Immunosuppression and Screening for Rejection

PURPOSE OF REVIEW

Recent developments in high-throughput DNA and RNA sequencing technologies have facilitated the development of noninvasive assays to monitor heart transplant rejection. In this review, we summarize existing assays employed for the surveillance of allograft rejection, as well as promising future directions for such tests in the molecular biology field.

RECENT FINDINGS

The AlloMap genome expression profiling assay remains the only noninvasive test for rejection surveillance and is incorporated into the International Society of Heart and Lung Transplantation guidelines. Other efforts have focused on messenger RNA (mRNA), microRNA (miRNA), and donor-derived cell-free DNA (dd-cfDNA) as potential viable biomarkers. Mitochondrial pathways in allograft necroptosis and inflammation signaling may represent a novel direction for future research endeavors. Although endomyocardial biopsy remains the gold standard, several converging areas of molecular biology could soon yield successful alternative methods of heart transplant rejection monitoring, with the distinct advantage of avoiding procedural complications.

Making Cardiomyocytes from Pluripotent Stem Cells

The ability to differentiate pluripotent stem cells to cardiomyocyte lineages (PSC-CMs) has opened the door to new disease models and innovative drug and cell therapies for the heart. Nevertheless, further advances in the differentiation protocols are needed to fulfill the promise of PSC-CMs. Obstacles that remain include deriving PSC-CMs with proper electromechanical properties, coalescing them into functional tissue structures, and manipulating the genome to test the impact mutations have on arrhythmias and other heart disorders. This chapter gives a brief consideration of these challenges and outlines current methodologies that offer partial solutions.

The Fundamental Contribution of Judah Folkman in the Setting of Angiogenesis Assays

Judah Folkman (1933-2008) made seminal discoveries on the mechanisms of angiogenesis which have opened a field of investigation worldwide. This chapter summarizes the fundamental contribution of Folkman in the setting of angiogenesis assays in vivo and in vitro.

Historical Overview of In Vivo and In Vitro Angiogenesis Assays

Most of angiogenesis assays were designed and developed during Folkman's era. But the growth of new blood vessels in several pathologic conditions as tumor development or inflammation were observed long time ago.The development of new blood vessels was early observed by ancient Egyptians who tried to destroy them by applying empirical methods. From the first observations regarding angiogenesis to a personalized therapy targeting newly formed blood vessels a lot of experimental in vitro and in vivo angiogenesis assays have been developed. The present work will overview the oldest and less known part of angiogenesis assays development, and in addition, it will present the newest data in the experimental field of angiogenesis which is rapidly improved by the needs of new antiangiogenic and antivascular therapy development.

Carbon dots as rapid assays for detection of mercury(II) ions based on turn-off mode and breast milk

In this research, nitrogen co-doped carbon dots were synthesized by solid thermal method with citric acid used as the precursor of carbon, and melamine as nitrogen source. Such carbon dots show high quantum yield of 44%. Furthermore, the native fluorescence of CDs can be reduced by mercury(II), while other metals had no significant influence on fluorescence intensity. During the study, the optimal parameters were selected, such as pH or time for incubation with analyte. Under the optimal conditions, quenching effect caused by mercury ions was evaluated. It was observed that with increasing mercury concentration, the fluorescence of the carbon dots decreased proportionally. The response was characterized by linearity within the range from 2 to 14 μM. Moreover, the limit of detection was 0.44 μM. It was the first time that human milk was used as a real sample to test the applicability of carbon dots. The study results demonstrated good recovery in the 74-111% range (RSD < 6%) As a novel carbon material, CDs show promise for broader applications in analyzing complicated biological samples.

Loop-mediated isothermal amplification (LAMP) test for diagnosis of uncomplicated malaria in endemic areas: a meta-analysis of diagnostic test accuracy

Background

The global malaria decline has stalled and only a few countries are pushing towards pre-elimination. The aim of the malaria elimination phase is interruption of local transmission of a specified malaria parasite in a defined geographical area. New and improved screening tools and strategies are required for detection and management of very low-density parasitaemia in the field. The objective of this study was to synthesize evidence on the diagnostic accuracy of loop-mediated isothermal amplification (LAMP) test for the detection of malaria parasites among people living in endemic areas.

Methods

This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Diagnostic Test Accuracy (PRISMA-DTA) guideline. Relevant studies in the health-related electronic databases were searched. According to the criteria set for this study, eligible studies were identified. The quality of included studies was evaluated with the use of a quality assessment checklist. A summary performance estimates such as pooled sensitivity and specificity were stratified by type of LAMP. Bivariate model for data analyses was applied. Summary receiver operating characteristics plots were created to display the results of individual studies in a receiver operating characteristics space. Meta-regression analysis was performed to investigate the sources of heterogeneity among individual studies.

Results

Twenty-seven studies across 17 endemic countries were identified. The vast majority of studies were with unclear risk of bias in the selection of index test. Overall, the pooled test performances were high for Pan LAMP (sensitivity: 0.95, 95% CI 0.91 to 0.97; specificity: 0.98, 95% CI 0.95 to 0.99), Plasmodium falciparum (Pf) LAMP (sensitivity: 0.96, 95% CI 0.94 to 0.98; specificity: 0.99, 95% CI 0.96 to 1.00) or for Plasmodium vivax (Pv) LAMP from 6 studies (sensitivity: 0.98, 95% CI 0.92 to 0.99; specificity: 0.99, 95% CI 0.72 to 1.00). The area under the curve for Pan LAMP (0.99, 95% CI 0.98–1.00), Pf LAMP (0.99, 95% CI 0.97–0.99) and Pv LAMP was (1.00, 95% CI 0.98–1.00) indicated that the diagnostic performance of these tests were within the excellent accuracy range. Meta-regression analysis showed that sample size had the greatest impact on test performance, among other factors.

Conclusions

The current findings suggest that LAMP-based assays are appropriate for detecting low-level malaria parasite infections in the field and would become valuable tools for malaria control and elimination programmes. Future well-designed larger sample studies on LAMP assessment in passive and active malaria surveillances that use PCR as the reference standard and provide sufficient data to construct 2 × 2 diagnostic table are needed.

Development of flow cytometry assays for measuring cell-membrane enzyme activity on individual cells

Background: Cell-membrane expressing enzymes such as ADAM (a disintegrin and metalloproteinase) superfamily members are thought to be key catalysts of vital cellular functions. To directly measure these enzymes and determine their association with particular cells and functions, individual-cell membrane-bound enzyme activity assays are required, but unavailable.

Methods: We developed two such assays, using a fluorescence resonance energy transfer (FRET) peptide substrate (FPS) and flow cytometry. One assay measured live-cell natural processing of FPS and binding of its fluorescent product onto individual-cell membrane-bound enzymes. The other assay measured processing of specifically-bound and glutaraldehyde-crosslinked FPS, and consequent generation of its coupled fluorescent product onto individual-cell membrane-bound enzymes.

Results: Confocal-microscopy imaging indicated that proteolytic processing of FPS selectively occurred on and labeled cell membrane of individual cells. The new assays measured specific increases of cell-associated FPS fluorescent product in substrate-concentration-, temperature- and time-dependent manners. A large proportion of processed FPS fluorescent products remained cell-associated after cell washing, indicating their binding to cell-membrane expressing enzymes. The assays measured higher levels of cell-associated FPS fluorescent product on wild-type than ADAM10-knockout mouse fibroblasts and on human monocytes than lymphocytes, which correlated with ADAM10 presence and expression levels on cell membrane, respectively. Furthermore, the enzyme activity assays could be combined with fluorescent anti-ADAM10 antibody staining to co-label and more directly associate enzyme activity and ADAM10 protein levels on cell membrane of individual cells.

Conclusions: We report on two novel assays for measuring cell-membrane anchored enzyme activity on individual cells, and their potential use to directly study specific biology of cell-surface-expressing proteases.

Methods for the Simple and Reliable Assessment of Barley Sensitivity to Abiotic Stresses During Early Development

Physiological assays that facilitate screening for various types of responses to abiotic stresses are well established for model plants such as Arabidopsis; however, there is a need to optimize similar tests for cereal crops, including barley. We have developed a set of stress assays to characterize the response of different barley lines during two stages of development-seed germination and seedling growth. The assays presented, including the response to osmotic, salt, oxidative stresses, and exogenously applied abscisic acid, can be used for forward screening of populations after mutagenesis as well as for phenotyping of already isolated mutants, cultivars, or breeding lines. As well as protocols for stress treatments, we also provide methods for plant stress response evaluation, such as chlorophyll a fluorescence (ChlF) and image analysis.

The central role of thrombin in bleeding disorders

Maintaining normal hemostasis relies on a regulated system of procoagulant and anticoagulant pathways, and disruption of these processes leads to the loss of hemostatic control, with the potential for excessive bleeding or thrombosis. Evaluation of bleeding disorders has conventionally been achieved by laboratory assays that measure the activity of individual coagulation factors. While such assays have proven effective for detecting abnormalities of the coagulation system and aiding diagnosis, inherent limitations prevent them from capturing a complete picture of hemostatic function. An improved understanding of thrombin activity and its central role in hemostasis and bleeding disorders has led to the clinical development of global assays that are more physiologically relevant than traditional assays; furthermore, these global assays are able to monitor responses to therapy. In this review, we provide an overview of the role of thrombin in hemostasis, and describe the clinical benefits of thrombin monitoring in patients with bleeding disorders. Moreover, we discuss recent advances in thrombin-targeting therapeutic strategies that aim to correct thrombin deficiency and prevent bleeding in patients with hemophilia and other rare bleeding disorders.

Enzymatic Synthesis of Repeating Unit Oligosaccharides of Escherichia coli O104

Escherichia coli serotype O104:H4 (ECO104) is a potent intestinal pathogen that causes severe bloody diarrhea and hemolytic-uremic syndrome. The O antigenic polysaccharides of ECO104 consist of repeating units with the structure [4Galα1-4Neu5,7,9Ac3α2-3Galβ1-3GalNAcβ1-]_n. These repeating units are assembled sequentially by specific glycosyltransferases on a diphosphate-undecaprenol intermediate. Internal structures include mimics of the human T and sialyl-T antigen. This protocol describes the in vitro synthesis of the repeating unit by β1,3-Gal-transferase WbwC, α2,3-sialyltransferase WbwA, and α1,4-Gal-transferase WbwB. All of these enzymes require acceptor substrates based on GalNAc-diphosphate-lipid. These methods are applicable for the assembly of bacterial polysaccharides of gram-negative bacteria that require sugar-diphosphate intermediates and are a basis for vaccine synthesis.

Defining a correlate of protection for chikungunya virus vaccines

Chikungunya virus infection causes a debilitating febrile illness that in many affected individuals is associated with long-term sequelae that can persist for months or years. Over the past decade a large number of candidate vaccines have been developed, several of which have now entered clinical trials. The rapid and sporadic nature of chikungunya outbreaks poses challenges for planning of large clinical efficacy trials suggesting that licensure of chikungunya vaccines may utilize non-traditional approval pathways based on identification of immunological endpoint(s) predictive of clinical benefit. This report reviews the current status of nonclinical and clinical testing and potential challenges for defining a suitable surrogate or correlate of protection.

State of the art in factor XIII laboratory assessment

Factor XIII, a heterotetrameric proenzyme, is converted to an activated transglutaminase by thrombin and calcium in the final phases of coagulation. Factor XIII catalyzes the formation of crosslinks between fibrin monomers and between α2-antiplasmin and fibrin. These crosslinks mechanically stabilize fibrin against shear stress, enable red cell retention within the clot, and protect the clot from premature degradation. Congenital factor XIII deficiency is caused by autosomal recessive mutations, presenting early in life with a severe bleeding diathesis. Acquired deficiency may be caused by autoimmunity. Currently available assays for laboratory diagnosis of factor XIII deficiency include clot solubility assays, quantitative factor XIII activity assays, factor XIII antigen assays, and genetic testing. The International Society on Thrombosis and Haemostasis Scientific and Standardization Committee has recommended an algorithm for the laboratory diagnosis and differentiation of the different forms of factor XIII deficiency. However, implementation of this algorithm has been limited by technical and budgetary challenges associated with the currently available factor XIII-specific assays. The purpose of this review is to discuss the advantages and limitations of the currently available assays employed for the laboratory diagnosis of factor XIII deficiency.

Hydroxyvitamin D assays: An historical perspective from DEQAS

Recent years have seen a substantial increase in demand for 25-hydroxyvitamin D (25-OHD) assays. DEQAS (the Vitamin D External Quality Assessment Scheme) has been monitoring the performance of these assays since 1989. The first DEQAS distribution was in June 1989 and results were submitted by 13 laboratories in the UK, two of which used HPLC/UV; the rest used ligand binding assays with a tritium tracer. Inter-laboratory CVs (ALTM) ranged from 29.3% (42.7nmol/L) to 53.7% (20.0nmol/L). Currently the scheme has participants in 56 countries using 30 methods or variants of methods. In January 2017, 918 participants returned results and inter-laboratory CVs (ALTM) ranged from 10.3% (73.1nmol/L) to 15.3% (29.4nmol/L). Over the last 27 years, there have been a number of significant milestones in assay development. The first major advance was the development of an iodinated 25-OHD tracer by Hollis and Napoli in 1992, subsequently used in an RIA kit marketed by DiaSorin. This and other commercial radioimmunoassays that followed brought 25-OHD assays within reach of many more non-specialist routine laboratories. With the introduction of fully automated non-isotopic assays without solvent extraction, measurement of 25-OHD became available to any clinical chemistry laboratory with an appropriate analytical platform. However, as the limitations of these non-extraction assays became apparent more laboratories started using LC-MS/MS methodology. Meanwhile the variable accuracy of 25-OHD methods has been addressed by the Vitamin D Standardization Program (VDSP) which encourages manufacturers to produce methods traceable to the reference measurement procedures (RMPs) of NIST, University of Ghent and the Centers for Disease Control and Prevention (CDC). DEQAS changed to an accuracy-based scheme in 2013 and now assesses assay accuracy against the NIST RMP. This review will use DEQAS results and statistics to chart the historical development in 25-OHD assay technology and highlight some of the problems encountered in obtaining reliable results for this most challenging of analytes.

Concordant testing results between various human papillomavirus assays in primary cervical cancer screening: systematic review

OBJECTIVES

Human papillomavirus (HPV) assays are increasingly used for primary cervical screening and HPV-vaccination-effect monitoring. We undertook a systematic literature review to determine the concordance in positive test results (i.e. detection of HPV infections) between Hybrid Capture 2 (HC2) and other assays.

METHODS

We searched PubMed, Embase and Scopus for studies of primary screening with HC2 and one or more assays, with cross-tabulated testing results for the assays. Two authors applied inclusion criteria and three authors extracted data from included studies. For each inter-assay comparison, we calculated the concordance by comparing the number of concordant samples with the number of samples that tested positive on at least one assay.

RESULTS

Sixteen studies fulfilled inclusion criteria, comparing nine assays to HC2, and including 392 to 9451 patients each. The calculated concordance varied between 48% and 69% for HC2 and APTIMA, Cobas, Abbott RealTime, Cervista, GP5+/6+, CLART, BD HPV test, Amplicor and Linear Array, i.e. 31%-52% of all positive tests on any pair of compared assays were discordant. Although modest variation in the degree of concordance with HC2 was suggested for particular assays, the numbers of studies per assay were generally low. No pronounced systematic patterns were observed by study (e.g. liquid medium) or population characteristics.

CONCLUSIONS

The ten commercially available assays do not detect the same HPV infections. Even in the most favourable case, the two assays provided discordant test results in 31% of all detected infections.

Undefined cellulase formulations hinder scientific reproducibility

In the shadow of a burgeoning biomass-to-fuels industry, biological conversion of lignocellulose to fermentable sugars in a cost-effective manner is key to the success of second-generation and advanced biofuel production. For the effective comparison of one cellulase preparation to another, cellulase assays are typically carried out with one or more engineered cellulase formulations or natural exoproteomes of known performance serving as positive controls. When these formulations have unknown composition, as is the case with several widely used commercial products, it becomes impossible to compare or reproduce work done today to work done in the future, where, for example, such preparations may not be available. Therefore, being a critical tenet of science publishing, experimental reproducibility is endangered by the continued use of these undisclosed products. We propose the introduction of standard procedures and materials to produce specific and reproducible cellulase formulations. These formulations are to serve as yardsticks to measure improvements and performance of new cellulase formulations.

The Alphabet Soup of HIV Reservoir Markers

PURPOSE OF REVIEW

Despite the success of antiretroviral therapy in suppressing HIV, life-long therapy is required to avoid HIV reactivation from long-lived viral reservoirs. Currently, there is intense interest in searching for therapeutic interventions that can purge the viral reservoir to achieve complete remission in HIV patients off antiretroviral therapy. The evaluation of such interventions relies on our ability to accurately and precisely measure the true size of the viral reservoir. In this review, we assess the most commonly used HIV reservoir assays, as a clear understanding of the strengths and weaknesses of each is vital for the accurate interpretation of results and for the development of improved assays.

RECENT FINDINGS

The quantification of intracellular or plasma HIV RNA or DNA levels remains the most commonly used tests for the characterization of the viral reservoir. While cost-effective and high-throughput, these assays are not able to differentiate between replication-competent or defective fractions or quantify the number of infected cells. Viral outgrowth assays provide a lower bound for the fraction of cells that can produce infectious virus, but these assays are laborious, expensive and substantially underestimate the potential reservoir of replication-competent provirus. Newer assays are now available that seek to overcome some of these problems, including full-length proviral sequencing, inducible HIV RNA assays, ultrasensitive p24 assays and murine adoptive transfer techniques. The development and evaluation of strategies for HIV remission rely upon our ability to accurately and precisely quantify the size of the remaining viral reservoir. At this time, all current HIV reservoir assays have drawbacks such that combinations of assays are generally needed to gain a more comprehensive view of the viral reservoir. The development of novel, rapid, high-throughput assays that can sensitively quantify the levels of the replication-competent HIV reservoir is still needed.

Scientific consultation on the safety and containment of new poliovirus strains for vaccine production, clinical/regulatory testing and research. Report of a meeting held at NIBSC, Potters Bar, Hertfordshire, UK, 6/7th July 2016

When poliomyelitis is totally eradicated from the natural world containment will be vital to prevent its re-emergence. The matter has become pressing as type 2 component of oral polio vaccine was completely withdrawn by May 2016 as wild ty[e 2 was declared eradicated. Work on polioviruses must be contained in accordance with GAPIII (the third version of the Global Action Plan of WHO). Some activities will be essential for years after eradication. Vaccine production and control, surveillance and supportive applied and academic research must all continue. Most laboratories do not currently comply with GAPIII and could not do so in the short term without disruption of essential activities including vaccine supply. The development and use of safer strains is raised in GAPIII and the meeting considered the strains available and the uses to which they could be put to facilitate compliance with the aims of GAPIII.

Use of poly ADP-ribose polymerase [PARP] inhibitors in cancer cells bearing DDR defects: the rationale for their inclusion in the clinic

BACKGROUND

DNA damage response (DDR) defects imply genomic instability and favor tumor progression but make the cells vulnerable to the pharmacological inhibition of the DNA repairing enzymes. Targeting cellular proteins like PARPs, which cooperate and complement molecular defects of the DDR process, induces a specific lethality in DDR defective cancer cells and represents an anti-cancer strategy. Normal cells can tolerate the DNA damage generated by PARP inhibition because of an efficient homologous recombination mechanism (HR); in contrast, cancer cells with a deficient HR are unable to manage the DSBs and appear especially sensitive to the PARP inhibitors (PARPi) effects.

MAIN BODY

In this review we discuss the proof of concept for the use of PARPi in different cancer types and the success and failure of their inclusion in clinical trials. The PARP inhibitor Olaparib [AZD2281] has been approved by the FDA for use in pretreated ovarian cancer patients with defective BRCA1/2 genes, and by the EMEA for maintenance therapy in platinum sensitive ovarian cancer patients with defective BRCA1/2 genes. BRCA mutations are now recognised as the molecular targets for PARPi sensitivity in several tumors. However, it is noteworthy that the use of PARPi has shown its efficacy also in non-BRCA related tumors. Several trials are ongoing to test different PARPi in different cancer types. Here we review the concept of BRCAness and the functional loss of proteins involved in DDR/HR mechanisms in cancer, including additional molecules that can influence the cancer cells sensitivity to PARPi. Given the complexity of the existing crosstalk between different DNA repair pathways, it is likely that a single biomarker may not be sufficient to predict the benefit of PARP inhibitors therapies. Novel general assays able to predict the DDR/HR proficiency in cancer cells and the PARPi sensitivity represent a challenge for a personalized therapy.

CONCLUSIONS

PARP inhibition is a potentially important strategy for managing a significant subset of tumors. The discovery of both germline and somatic DNA repair deficiencies in different cancer patients, together with the development of new PARP inhibitors that can kill selectively cancer cells is a potent example of targeting therapy to molecularly defined tumor subtypes.

Comparing high-throughput methods to measure NK cell-mediated antibody dependent cellular cytotoxicity during HIV-infection

HIV-specific binding antibody responses, including those mediating antibody-dependent cellular cytotoxicity (ADCC), provided the best functional correlate of lower risk of infection in the RV144 HIV-1 vaccine clinical trial. The aim of this study was to compare two high-throughput flow cytometry based methods to measure HIV-specific ADCC responses, the GranToxilux and PanToxilux assays. Plasma from nine HIV-1 seropositive individuals was screened for binding antibody titres against HIV-1 subtype C gp120 by ELISA and western blot. Plasma from six HIV-negative individuals was included as controls. Both ADCC assays used subtype C gp120-coated CEM.NKRCCR5 cells as targets. The PanToxilux assay (which measured both granzyme B and caspase activity) measured higher levels of direct natural killer (NK) cell killing of K562 tumour cells than the GranToxilux assay (granzyme B alone; p<0.05). In ADCC assays in which NK cell killing was directed against gp120-coated CEM.NKRCCR5 cells in an antibody-dependent manner, plasma from HIV-positive individuals yielded significantly higher levels of ADCC activity than the HIV-negative controls. In contrast to direct killing, the GranToxilux assay measured similar levels of ADCC killing as the PanToxilux assay but had significantly lower background cytotoxicity against target cells coated with HIV negative serum. In conclusion, the PanToxilux assay was more sensitive for detecting direct NK cell killing of K562 cells than the GranToxilux assay, although the GranToxilux assay performed better at detecting HIV-specific ADCC activity, because of lower background cytotoxicity from HIV-negative serum. This is the first study to compare GranToxilux and PanToxilux ability to detect ADCC during HIV infection.

Polysaccharides and lignin from oak wood used in cooperage: Composition, interest, assays: A review

It is widely accepted that alcoholic beverage quality depends on their ageing in premium quality oak wood. From the choice of wood to beverage ageing, through the different steps in cask manufacturing, many factors should be considered. One of the biggest challenge in cooperages is to take into account all these factors. Most of the studies are interested in phenolic compounds, extracted during ageing and especially involved in wine oxidation, colour, and sensory properties such as astringency and bitterness. Oak aroma volatile compounds have also been the subject of numerous studies. These compounds of interest are part of low molecular weight compounds which represent 2%-10% of oak wood composition. However, three polymers constitute the main part of oak wood: cellulose, hemicellulose and lignin. As far as we are aware, few studies concerning the role of these major macromolecules in oak wood have been published previously. This article reviews oak wood polysaccharides and lignin, their potential interest and different assays used to determine their content.

Oxidative stress, the term and the concept

The 30th birthday of a central concept in biomedicine, such as oxidative stress (OS) is a good time for re-evaluation of its contribution to science and particularly to the field of redox biology. In his recent communication, Sies described the history of the concept as well as the benefits and pitfalls of the term OS. In this mini-review, we discuss the problems associated with the still common perception of "bad OS, good antioxidants". Specifically, the term OS is an intuitively understood term originally used to describe an imbalance between pro-oxidative factors and anti-oxidative factors. It has no units, its level is dependent on the way it is measured and there is no correlation between various criteria of OS, which indicates that there are sub-classes (types) of OS (other than the classifications presented by Sies). In spite of these limitations, it is commonly regarded a measure of a person's probability to suffer from oxidative damages and is being held responsible for many diseases and antioxidants are predicted to be good to us. In fact, a "Basal OS" is vital and antioxidants may interfere with the mechanisms responsible for maintaining the oxidative status. We also discuss the linkage of OS to the outcome of antioxidant supplementation and comment on the importance of kinetic studies in evaluation of OS and on the ranking of antioxidants.

Methods used in preclinical assessment of anti-Buruli ulcer agents: A global perspective

Buruli ulcer (BU) caused by Mycobacterium ulcerans is the third most common chronic mycobacterial infection in humans. Approximately 5000 cases are reported annually from at least 33 countries around the globe, especially in rural African communities. Even though anti-mycobacterial therapy is often effective for early nodular or ulcerative lesions, surgery is sometimes employed for aiding wound healing and correction of deformities. The usefulness of the antibiotherapy nonetheless is challenged by huge restrictive factors such as high cost, surgical scars and loss of income due to loss of man-hours, and in some instances employment. For these reasons, more effective and safer drugs are urgently needed, and research programs into alternative therapeutics including investigation of natural products should be encouraged. There is the need for appropriate susceptibility testing methods for the evaluation of potency. A number of biological assay methodologies are in current use, ranging from the classical agar and broth dilution assay formats, to radiorespirometric, dye-based, and fluorescent/luminescence reporter assays. Mice, rats, armadillo, guinea pigs, monkeys, grass cutters and lizards have been suggested as animal models for Buruli ulcer. This review presents an overview of in vitro and in vivo susceptibility testing methods developed so far for the determination of anti-Buruli ulcer activity of natural products and derivatives.

Enhancing longevity of Plasmodium vivax and P. falciparum sporozoites after dissection from mosquito salivary glands

The pre-erythrocytic stages of Plasmodium vivax and Plasmodium falciparum remain challenging for experimental research in part due to limited access to sporozoites. An important factor limiting availability is the laboratory support required for producing infected mosquitoes and the ephemeral nature of isolated extracellular sporozoites. This study was undertaken to investigate methods to improve the availability of this limited resource by extending the longevity of the extracellular sporozoites after mosquito dissection. Our goal in this study was to determine whether buffer conditions more closely mimicking the insect microenvironment could prolong longevity of ex vivo P. vivax and P. falciparum sporozoites. The study compared the current standard dissection buffer RPMI1640 to Hank's Balanced Salt Solution with 1g/L glucose (HBSS-1) or 2g/L glucose (HBSS-2) and Grace's Insect Medium for ability to extend longevity of ex vivo P. vivax and P. falciparum sporozoites. The effect of each buffer on sporozoite viability was evaluated by measuring sporozoite gliding motility at 0, 4, 8, and 24h post-dissection from mosquito salivary glands. Comparisons of mean gliding percentages of ex vivo sporozoites in the different buffers and time points found that RPMI and Grace's both showed strong gliding at 0h. In contrast, by 4h post-dissection sporozoites in RPMI consistently had the lowest gliding activity, whereas sporozoites in Grace's had significantly more gliding compared to all other buffers at almost all time points. Our results indicate that P. vivax and P. falciparum sporozoites maintained in insect media rather than the standard dissection buffer RPMI and HBSS retain viability better over time.

The role of biomarkers in the assessment of aquatic ecosystem health

Ensuring the health of aquatic ecosystems and identifying species at risk from the detrimental effects of environmental contaminants can be facilitated by integrating analytical chemical analysis with carefully selected biological endpoints measured in tissues of species of concern. These biological endpoints include molecular, biochemical, and physiological markers (i.e., biomarkers) that when integrated, can clarify issues of contaminant bioavailability, bioaccumulation, and ecological effects while enabling a better understanding of the effects of nonchemical stressors. In the case of contaminant stressors, an understanding of chemical modes of toxicity can be incorporated with diagnostic markers of aquatic animal physiology to help understand the health status of aquatic organisms in the field. Furthermore, new approaches in functional genomics and bioinformatics can help discriminate individual chemicals, or groups of chemicals among complex mixtures that may contribute to adverse biological effects. Although the use of biomarkers is not a new paradigm, such approaches have been underused in the context of ecological risk assessment and natural resource damage assessment. From a regulatory standpoint, these approaches can help better assess the complex effects from coastal development activities to assessing ecosystem integrity pre- and post development or site remediation.

UK approach to assessing assays and filters designed to reduce the risk of transfusion-transmitted vCJD

Three cases of vCJD transmission by blood transfusion have been reported in the UK, and a fourth case discovered at post-mortem. Modelling has been conducted to predict the number of cases that may occur in the future through transfusion, based on estimates of prevalence, infectivity and susceptibility, and a number of steps have been taken to reduce the risk of transmission. These include deferral of previously transfused donors, leucocyte depletion of all components, importation of plasma for certain patient groups and for fractionation, and the collection of the majority of platelets from single donors (by apheresis). However, even with these interventions, some future cases are still predicted. The UK-wide Advisory Committee on the Safety of Blood, Tissues and Organs (SaBTO) considers the evidence for clinical and cost-effectiveness of any proposed intervention, such as prion assays and filters, and makes recommendations to the governments of the UK. The development of prion assays is challenging as prions do not generate an immune response, do not have nucleic acid and are present in blood in very low concentrations against a high background of normal prion protein. It is critically important that prion assays show high levels of sensitivity and - especially -specificity for a healthy blood donor population. Assessment is impacted by the very short supply of positive human samples, necessitating the use of animal models. Filters that are capable of removing prions from blood components have been developed and CE marked, but it is again necessary to use animal models to study their efficacy. Guidelines have been produced for the assessment of the quality of red cells filtered through these devices, and a clinical safety study has recently been completed. In conclusion, the evaluation of screening assays and prion filters is challenging, time-consuming and costly, but these evaluations are critical to policy making.

A review on angiogenesis and its assays

Angiogenesis or formation of new blood vessels from preexisting vasculature is a key process in some physiological conditions such as wound healing, growth, and action of female reproductive organs. Moreover, disturbance of the mechanisms of physiological angiogenesis has a role in pathogenesis of some diseases in the form of overproliferation of blood vessels such as cancers, psoriasis, arthritis, retinopathies, obesity, asthma, and atherosclerosis or impaired angiogenesis participates in diseases such as heart and brain ischemia, neurodegeneration, hypertension, osteoporosis, respiratory distress, preeclampsia, endometriosis, postpartum cardiomyopathy, and ovarian hyperstimulation syndrome. Research and study in angiogenesis provide a potential to cure a variety of diseases such as cancers or cardiovascular diseases. Thus, in recent years, several methods for evaluation of angiogenesis have been introduced and selecting the most appropriate cure is very important. In this article, first, we briefly reviewed appropriate assays to evaluate therapeutic angiogenesis (clinical manipulation of angiogenesis) and its importance during some clinical diseases and then introduced in vitro, in vivo, and ex vivo assays of angiogenesis besides their benefits and disadvantages. Next, some quantitative techniques for assessing angiogenesis have been discussed.