Malaria diagnosis in a malaria non-endemic high-resource country: high variation of diagnostic strategy in clinical laboratories in the Netherlands.

BACKGROUND: Microscopic examination of thick and thin blood films is the gold standard in current guidelines for the diagnosis of malaria, but guidelines do not uniformly agree on which combination of other methods should be used and when. METHODS: Three questionnaires were sent between March 2018 and September 2019 to laboratories subscribing to the external quality assessment scheme for the diagnosis of blood and intestinal parasites of the Dutch Foundation for Quality Assessment in Medical Laboratories in order to investigate how much variation in the laboratory diagnosis of malaria between different clinical laboratories is present in the Netherlands. RESULTS: The questionnaires were partially or fully completed by 67 of 77 (87%) laboratories. Only 9 laboratories reported 10 or more malaria positive patients per year. Most laboratories use a different diagnostic strategy, within office versus outside office hours depending on the screening assay result. Within office hours, 62.5% (35/56) of the responding laboratories perform an immunochromatographic test (ICT) in combination with microscopic examination of thick and thin blood films without additional examinations, such as Quantitative Buffy Coat and/or rtPCR analysis. Outside office hours 85.7% (48/56) of laboratories use an ICT as single screening assay and positive results are immediately confirmed by thick and thin blood films without additional examinations (89.6%, 43/48). In case of a negative ICT result outside office hours, 70.8% (34/48) of the laboratories perform microscopic examination of the thick film the next morning and 22.9% (11/48) confirm the negative ICT result immediately. Furthermore, substantial differences were found in the microscopic examinations of thick and thin blood films; the staining, theoretical sensitivity of the thick film and determination of parasitaemia. CONCLUSIONS: This study demonstrated a remarkably high variation between laboratories in both their diagnostic strategy as well as their methods for microscopic examination for the diagnosis of malaria in a clinical setting, despite existing national and international guidelines. While the impact of these variations on the accuracy of the diagnosis of malaria is yet unknown, these findings should stimulate clinical laboratories to critically review their own diagnostic strategy.

Deep learning-based transformation of H&E stained tissues into special stains.

Pathology is practiced by visual inspection of histochemically stained tissue slides. While the hematoxylin and eosin (H&E) stain is most commonly used, special stains can provide additional contrast to different tissue components. Here, we demonstrate the utility of supervised learning-based computational stain transformation from H&E to special stains (Masson's Trichrome, periodic acid-Schiff and Jones silver stain) using kidney needle core biopsy tissue sections. Based on the evaluation by three renal pathologists, followed by adjudication by a fourth pathologist, we show that the generation of virtual special stains from existing H&E images improves the diagnosis of several non-neoplastic kidney diseases, sampled from 58 unique subjects (P = 0.0095). A second study found that the quality of the computationally generated special stains was statistically equivalent to those which were histochemically stained. This stain-to-stain transformation framework can improve preliminary diagnoses when additional special stains are needed, also providing significant savings in time and cost.

Chemical analysis of saffron by HPLC based crocetin estimation.

Saffron is one of the most expensive and valuable spice having tremendous commercial value in food industry and thus its quality check is of utmost importance. Crocins are unique group of extremely hydrophilic apocarotenoids which are main components of saffron. Crocetin is an aglycone of crocins which do occur naturally in saffron, and is produced in biological system as a bioactive metabolite via hydrolytic cleavage of crocins. Crocins are unstable and tend to undergo isomerisation/ inter-conversions, and therefore their quantitative estimation is difficult. Herein, we have established for the first time, a crocetin-based HPLC method to evaluate the total crocin content of saffron, and thereby analyze the quality of saffron. The present approach comprises alkali-mediated conversion of crocins to crocetin in raw material followed by quantitative estimation of in-situ formed crocetin by HPLC analysis. The unique and efficient protocol for preparation of high purity analytical grade 'crocetin' directly from saffron has also been established. It is simple and efficient way to check the quality of saffron/ saffron-containing products.

Diagnostic utility of touch imprint cytology for intraoperative assessment of surgical margins and sentinel lymph nodes in oral squamous cell carcinoma patients using four different cytological stains.

BACKGROUND: OSCC is most commonly associated with positive surgical margins. The important cause of loco regional recurrence is histologically positive or closed margins. Clear surgical margins might favor the patient with a better prognosis and prevent repetitive surgeries. The present study was designed to the diagnostic utility of touch imprint (TI) smears using H and E, Pap, Giemsa and Feulgen stains, so that they can be used on a routine basis. MATERIALS AND METHODS: A total of 720 smears from 130 margins resected from 32 patients who underwent surgical resection of OSCC were prospectively evaluated. The slides were fixed in alcohol and randomly divided into four different batches for staining with H&E, rapid Pap, Giemsa, Feulgen stain. TI of 30 sentinel lymph node were fixed in 95% alcohol, stained by (H&E) and evaluated by two independent observers. The results were compared with gold standard histopathology. RESULTS: H&E stain showed sensitivity 44%, rapid Pap 35%, Giemsa 29% and Feulgen stain 25%. Positive predictive value-100% for all the four stains. NPV-H&E 70%, Pap 66%, Giemsa 62%, Feulgen 59%. Diagnostic test accuracy of H&E stained smears was higher 72%, compared to Pap 67%. Giemsa 65%, and Feulgen 63%. In lymph nodes, Specificity was 94.74%, PPV 90.91%, NPV 94.74%, diagnostic accuracy 93.33%. CONCLUSION: TIC is effective in identifying an inadequate or severe dysplasia margin comparable to gold standard histopathology. It might be used to intraoperatively identify metastases in sentinel lymph nodes in clinically N0 Patients.

Diagnostic application of patent blue V in sentinel lymph node biopsy for breast cancer - Is it time for a change?

Sentinel lymph node biopsy (SLNB) was introduced in the 1990s, as a minimally invasive procedure for staging the axilla with less morbidity to the traditional axillary lymph node dissection and is now standard management of the axilla in the early breast cancer. SLNB using the combined technique of blue dye and radioisotope is currently the recommended method for lymphatic mapping, and studies have shown high identification rates (IR) (>95%) and low false-negative rates (FNR) 5-10%. However, there are several reports raising awareness regarding patent blue V dye-induced peri-operative anaphylaxis. The main aim of this article is to highlight the emergence of patent blue dye as a new allergen and present evidence regarding the utility of alternative safer methods of evaluation of early breast cancer without compromising IR.

A Standardized Method of Applying Toluidine Blue Metachromatic Staining for Assessment of Chondrogenesis.

OBJECTIVES: Staining with toluidine blue is a well-established procedure for the histological assessment of cartilaginous- and chondrogenic-differentiated tissues. Being a cationic dye, toluidine blue staining visualizes proteoglycans in a tissue because of its high affinity for the sulfate groups in proteoglycans. It is generally accepted that metachromatic staining with toluidine blue represents cartilaginous matrix and that the degree of positive staining corresponds with the amount of proteoglycans. DESIGN: Articular cartilage and pellets of chondrocytes or bone marrow stromal cells were analyzed with a standardized staining procedure for toluidine blue. RESULTS: In the present study, we illustrate why such an assumption is invalid unless a detailed description of the procedure and/or reference to a detailed published method are provided. This is because the staining specificity and intensity depend, as we have shown, on the pH of the staining solution, the use of dehydration, and on staining time. CONCLUSIONS: We can, therefore, suggest a well-controlled standardized protocol for toluidine blue staining, which provides an easy and simple selective staining technique for the assessment of cartilage tissue and proteoglycan development in chondrogenic differentiation. If this procedure is not used, then investigators must provide sufficient technical information concerning the staining protocol to allow an assessment of the validity of the staining results.

Temporal changes in chromium allergy in Denmark between 2002 and 2017.

BACKGROUND: In 2012, Danish authorities submitted a proposal to the European Chemical Agency restricting the content of hexavalent chromium to a maximum of 3 ppm in leather goods. Following its adoption, this proposal was implemented in 2015 as a directive in the EU. OBJECTIVES: To examine the temporal trend of chromium contact allergy in adult dermatitis patients patch tested between 2002 and 2017, and to determine clinical characteristics and causative exposures in these patients. METHODS: All adult dermatitis patients patch tested between 2002 and 2017 were included. Patch test data were reviewed retrospectively. Comparisons were performed with the χ 2 test and logistic regression analysis. RESULTS: A total of 13 379 adults aged 18 to 99 years were patch tested between 2002 and 2017. The overall prevalence of chromium allergy was 2.2%. An overall decreasing trend was found for the prevalence of chromium allergy (Ptrend = 0.00002). Specifically, a significant difference was found for the study periods 2010 to 2013 (Ptrend = 0.002) and 2014 to 2017 (Ptrend < 0.0001) as compared with 2002 to 2005. Leather remained the most important single cause of allergic contact dermatitis caused by chromium. The proportion of clinically relevant leather exposures increased from 42.3% during 2002 to 2009 to 54.8% during 2010 to 2017 (P = 0.04). CONCLUSIONS: The prevalence of chromium allergy is decreasing. The EU Directive restricting the use of hexavalent chromium in leather goods is thought to be playing a central role in this change.

A new high-throughput method to make a quality control on tattoo inks.

Nowadays, practice of tattooing is very common worldwide and, along with this increasing trend, there is also an increased risk of adverse reactions to tattoo pigments that are well known and described in literature. Previous studies have reported that cutaneous and allergic reactions to a particular pigment can manifest in several ways (allergic contact dermatitis and photo-allergic dermatitis). In this paper, a new high-throughput method is presented, in order to achieve a new system for the quality control on tattoo inks based on chromatographic-spectroscopic approach. The samples, twenty-one tattoo inks and three permanent makeup, comprised the following colors: black inks, yellow, blue, green, white, pink and various shades of red (pigment that gives many allergic responses) were analyzed through the combination of chromatographic and spectroscopic techniques, the HPTLC-Raman. In particular, Raman technique has been chosen because of its high sensitivity towards the inorganic and organic pigments, main constituents of tattoo inks. Moreover, the advantage of this hyphenated technique is to overcome the problem of analysing the complex mixture of tattoo inks, allowing to obtain a Raman spectrum of each single component, isolated by chromatographic separation. This approach aims at developing a powerful instrument to establish the nature of tattoo inks and substances that could be cause adverse reactions in tattooed patients.

Prospective comparison of cytological specimen adequacy assessment by different rapid staining techniques for rapid on-site evaluation in fine needle aspiration cytology and their cost-effectiveness.

OBJECTIVE: Rapid on-site evaluation (ROSE) is a technique beneficial in determining the adequacy of the samples, thereby increasing the diagnostic yield, useful in triage of specimens for ancillary studies and can also help determine a preliminary diagnosis in emergency cases. The different rapid stains for on-site evaluation described in the literature are diff quik, toluidine blue (TB), brilliant cresyl blue (BCB), ultra-fast Pap stains, and rapid hematoxylin and eosin (H&E). This study was undertaken as there is sparse literature regarding the best and the most cost-effective rapid stain. METHOD: Fine needle aspiration samples from 200 patients with palpable swellings in easily accessible regions were taken. Smears stained by rapid and routine stains were assessed based on four parameters, with provisional diagnosis on the rapid stained smears. A comparative analysis of the advantages and disadvantages of the rapid stains was carried out with appropriate statistical tests with the routinely stained smears as gold standard. RESULTS: There was adequate material in 100% of ROSE smears. rapid pap stained smears showed well preserved cytoplasmic details, nuclear details, and background details. The time taken was least with TB and BCB being 5 s each. The most cost-effective was found to be TB. CONCLUSIONS: We conclude that TB is the most cost-effective, quick, least labor-intensive, and reliable rapid stain for ROSE especially in resource-poor settings.

Papanicolaou induced fluorescence, Ziehl-Neelsen and Auramine O stains on lymph node fine needle aspiration biopsy specimens from children: A comparative study.

BACKGROUND: The rapid diagnosis of extrapulmonary tuberculosis in children remains challenging. The presence of enlarged lymph nodes provides an opportunity to obtain diagnostic material through fine needle aspiration biopsy (FNAB). Mycobacterial culture, traditionally the reference standard, has a slow turnaround time and PCR-based methods are not widely available in developing countries. Direct visualization of mycobacteria on microscopy can be a rapid method to confirm the diagnosis. This study compared three staining methods to visualize mycobacteria. METHODS: Hundred FNAB specimens from persistently enlarged lymph nodes in children, clinically suspicious for tuberculosis, were evaluated for the presence of mycobacteria by three staining methods: Papanicolaou induced fluorescence (PIF) and Auramine O staining using fluorescence microscopy and Ziehl-Neelsen (ZN) staining using conventional light microscopy. These methods were evaluated against mycobacterial culture. RESULTS: PIF positivity was 30%, with 38% and 48% for Auramine O and ZN respectively. The combined ZN/PIF positivity was 56%. The highest diagnostic accuracy (73%) was demonstrated by ZN alone and in combination with PIF, with PIF alone showing the lowest (49%) accuracy. Although the combined test showed the highest sensitivity, it had the lowest specificity, while ZN was significantly more sensitive than both other staining modalities. No statistical difference in specificity was seen among the tests. CONCLUSION: This study suggests that Auramine O staining on previously ZN stained slides does not significantly improve diagnostic accuracy. While currently widely available methods of direct visualization of mycobacteria suffer from low sensitivity, the ZN stain remains a useful diagnostic test, particularly in resource-constrained countries.

Reconsidering the H&E stain as the gold standard in assessing the depth of burn wounds.

While histological examination is considered by most as the gold standard for burn depth assessment, it has no practical use in the clinical setting. It has, however, been used in the research setting, as a mean for evaluating emerging techniques of depth measurement. Due to the limitations of the H&E stain, other stains have also been explored, such as lactate dehydrogenase (LDH), as presented in this issue, in "Improving the Histologic Characterization of Burn Depth." As the determination of burn depth is not a typical subject in dermatopathology, a summary of selected techniques and the possible role for the LDH stain in future research, is described herein.

Establishing Standards on Colors from Natural Sources.

Color additives are applied to many food, drug, and cosmetic products. With up to 85% of consumer buying decisions potentially influenced by color, appropriate application of color additives and their safety is critical. Color additives are defined by the U.S. Federal Food, Drug, and Cosmetic Act (FD&C Act) as any dye, pigment, or substance that can impart color to a food, drug, or cosmetic or to the human body. Under current U.S. Food and Drug Administration (FDA) regulations, colors fall into 2 categories as those subject to an FDA certification process and those that are exempt from certification often referred to as "natural" colors by consumers because they are sourced from plants, minerals, and animals. Certified colors have been used for decades in food and beverage products, but consumer interest in natural colors is leading market applications. However, the popularity of natural colors has also opened a door for both unintentional and intentional economic adulteration. Whereas FDA certifications for synthetic dyes and lakes involve strict quality control, natural colors are not evaluated by the FDA and often lack clear definitions and industry accepted quality and safety specifications. A significant risk of adulteration of natural colors exists, ranging from simple misbranding or misuse of the term "natural" on a product label to potentially serious cases of physical, chemical, and/or microbial contamination from raw material sources, improper processing methods, or intentional postproduction adulteration. Consistent industry-wide safety standards are needed to address the manufacturing, processing, application, and international trade of colors from natural sources to ensure quality and safety throughout the supply chain.

Improving the histologic characterization of burn depth.

BACKGROUND: Visual assessment of burn wound appearance is the standard of care to determine the depth of thermal injury but often incorrectly predicts wound healing potential. Histologic evaluation of hematoxylin and eosin (H&E) stained burn tissue is prone to subjectivity and is challenging for the novice. Lactate dehydrogenase (LDH) staining may offer a simplified and consistent technique to identify burn tissue viability. METHODS: Thirty tissue samples were obtained from 6 patients undergoing surgical excision for clinically determined deep partial thickness or full thickness burns. Tissues were stained with H&E or LDH. Each specimen was scored by 3 individuals with varying levels of skill in histologic interpretation using a standardized checklist at 2 distinct time points. RESULTS: Agreement within raters was highest for the expert rater and lowest for the novice; however, the LDH stained tissue method had improved agreement for an experienced burn surgeon and novice. Agreement between raters was greater for the LDH stained samples which were determined to have greater viability than the corresponding H&E section in 100% of samples scored by the expert and in 80% for the novice clinician. CONCLUSION: LDH staining offers a more consistent measure of tissue viability that can be used by experienced and novice clinicians.

Application of a colorimetric technique in quality control for printed pediatric orodispersible drug delivery systems containing propranolol hydrochloride.

The feasibility of a colorimetric technique was investigated in CIELAB color space as an analytical quality control method for content uniformity of printed orodispersible pediatric delivery systems. Inkjet printing was utilized to fabricate orodispersibe film formulations containing propranolol hydrochloride in a colored ink base using three different edible substrates. A thin sweetener coating layer of saccharin was successfully included in the final dosage forms for palatability purposes using a casting knife. Optical microscopy, scanning electron microscopy and scanning white light interferometry analyses were conducted to study the effect of printing on the surface morphology and topography of the substrates. Differential scanning calorimetry and attenuated total reflectance infrared spectroscopy were used to study the solid state properties and possible interactions between the drug and the excipients. The inkjet printing technique deposited precise and uniform escalating doses (0.08-3.16mg) of the active pharmaceutical ingredient onto the substrates (R(2)≥0.9934). A disintegration test with clear end-point detection confirmed that all the substrates meet the requirements of the Ph. Eur. to disintegrate within 180s. The colorimetric technique proved to be a reliable method to distinguish the small color differences between formulations containing an escalating dose of propranolol hydrochloride.

Towards the limiting of health risks associated with tattooing: whitelists for tattoo pigments and preservatives.

The number of pigments that could potentially be used in tattoo inks is vast. However, pigments are generally not manufactured for the purpose of being injected into subepidermal layers of the skin. Assuming 100% bioavailability after injection means that pigments can be imminently hazardous to human health. Given the ever-increasing number of pigments being circulated on the market or through the internet, a 'negative list' ('black' list) containing pigments with known adverse effects will never be finalised. If incriminated, substances could easily be replaced by structurally similar pigments that might be even more deleterious to human health. Therefore, we and others suggest the establishment of a whitelist ('positive list') that would only contain pigments that had undergone a risk assessment specifically for their application into the dermis. Some of the problems associated with such a 'positive list' are discussed. Another important issue with regard to tattoo safety is related to the preservatives used in ink preparations. Notwithstanding the demand for sterile tattoo inks, a whitelist for these compounds would be beneficial. At present, many technical preservatives are being used, despite their known detrimental effects to human health. Criteria for the inclusion of preservatives in a 'positive list' are also discussed.

Survey of studies on microbial contamination of marketed tattoo inks.

Tattooing became a popular phenomenon during the late twentieth century. Because the act of tattooing involves repeated injection of ink through the skin, a risk of contracting infections from contaminated tattooing equipment and ink and the surrounding environment exists. Progress has been made in infection control strategies; however, contraction of bacterial and viral infections from tattooing continues to occur. The risk of acquiring a tattoo-related infection largely depends on the hygiene conditions under which the tattoo is applied. Nevertheless, even when adequate hygiene and sanitation measures are taken, the inks themselves may contain infectious microorganisms that are able to survive under hostile conditions, such as in inks. The results of the few studies on the microbiological quality of unopened and opened tattoo inks are reported. Some authors' conclusions demonstrated that the current ink sterilisation systems show a low capability to inactivate microbial contamination in tattoo inks. At the moment, European Resolution ResAP2008-1 recommends that the ink be sterile and supplied in containers that maintain the sterility of the product until application. In light of the outcomes of published studies, at the moment, preservation of the microbial quality and safety of ink seems challenging and still difficult to reach.

The European landscape of national regulations of tattoo inks and businesses.

A rising number of tattooed people in all parts of society and increasing concerns regarding potential health effects triggered the development of specific regulatory measures at the beginning of the 21st century. The first principles considering chemical safety and hygienic aspects were laid down by two resolutions of the Council of Europe, in 2003 and 2008. The applied principle of 'negative lists' of substances that should not be used in tattoo inks has subsequently been transferred to national regulations. However, surveillance data show that in particular, the chemical quality of tattoo inks is still insufficient. The reasons are, amongst others, the lack of analytical methods, the implementation of different thresholds, and the lack of awareness of distributors and producers when it comes to potential health hazards.

Implementation of European Council resolution ResAP(2008)1 in Italy. National and regional regulation of tattoo practices: diversity and challenges.

In Italy, tattoos and permanent make-up have become increasingly popular in recent years. The number of tattoo parlours has increased from 257 in 2009 to 2,055 in 2014, wich is a eight-fold increase over the last 6 years. Although there is no specific legislation, the Italian Ministry of Health issued a document containing the 'Guidelines for the implementation of procedures for tattooing and piercing in safe conditions'. This document has not been adopted by all Italian regions, principally regarding training course requirements for tattoo professionals, creating a highly fragmented situation that resembles the European scene in miniature. ResAP(2008)1, which is not mandatory in Italy but was made binding by Italian Decree n. 206/2005, has been applied uniformly throughout the country. Thus, as far as the safety of inks is concerned, the surveillance system appears to be working well. However, surveillance has highlighted the presence of non-compliant inks and potentially unsafe preparations for tattoo removal in the market. Updating and rebalancing the situation will be the goal in order to face the challenge of combining well-being with the on-going social demand of looking after and beautifying the body. This would include the growing fashion of tattoos, provided that the products that are used are safe and that tattooing is performed in controlled hygienic conditions that fully guarantee the health of consumers.

EU actions to ensure the safety of tattoos and the protection of consumers.

The number of tattooed persons has been continuously increasing in the last few years, particularly in the younger population. At the same time, the possibility of purchasing tattoo inks online is easier than ever worldwide. Consumers are not always sufficiently aware of the possible health problems associated with this 'cool fashion' if hygiene conditions are not respected and/or if the injected mixtures contain dangerous chemicals. Concerns about the possible health risks associated with such practices arise from the absence of a clear legislative framework, the lack of proper risk assessment of the chemicals used, and non-harmonised or missing hygiene and purity requirements, among other factors. There is a general consensus among all active stakeholders that EU harmonised rules would help to ensure a consistent high level of protection of consumers across the EU.

Seamless prevention of adverse events from tattooing: integrated strategy emphasising the customer-tattooist interaction.

The boom in tattooing has been paralleled by more frequent adverse events, which may be localised in the skin or systemic and manifested clinically or latent. Infections, allergic reactions from red-coloured tattoos and papulo-nodular reactions from black tattoos dominate. Mild complaints are very common, with 1/5 of all tattooed individuals having acquired sensitivity to sunlight in the tattooed skin. The potential risk of cancer due to potential carcinogens in some tattoo inks has hitherto not manifested in clinical reports, despite the millions of people who have been tattooed over many decades. A risk of death from tattooing remains associated with severe infection, i.e. sepsis. Preventive strategies may rely on focused preventions, and sterility and preservation of ink is essential, rational and knowledge-based. The chemical and particle contents of ink nanoparticles cannot be unrestricted; however, focused control of ink is facing many uncertainties, including analytical problems, lack of identification of allergens in ink and discrepancies between the content of potential carcinogens and manifestation of cancer in the clinic. The concept of seamless prevention is introduced as a pragmatic strategy that emphasises the customer-tattooist interaction, which is the 'engine' of tattoo safety. This strategy amalgamates the range of narrow-scope preventive instruments and shall ensure that any relevant instrument is used actively and without deficiency or drop out, thus resulting in a complete orchestration of a multi-targeted strategy. High-priority elements of this strategy shall facilitate a qualified 'go' or 'no go' decision by the customer before the tattoo is made and should involve informed consent, qualification of the tattooist and the parlour, including supplies of inks etc., and attention to hygienic security. Records and documentation of tattoo cases with complications and the culprit inks as well as the establishment of national or European-based surveillance systems that are properly equipped to deliver efficient clarification and handling of adverse events and hazards of tattooing and inks, which needs attention and timely action to prevent additional cases and epidemic outbreaks, are part of this seamless strategy, along with optimised medical therapy and research.