The Safety Assessment of Cosmetic Perfumes by Using In Chemico and In Vitro Methods in Combination with GC-MS/MS Analysis

Animal testing has been prohibited for the safety assessment of cosmetic ingredients or finished products. Thus, alternative non-animal methods, followed by confirmatory clinical studies on human volunteers, should be used as the sole legally acceptable approach within the EU. The safety assessment of cosmetic products requires the involvement of multiple scientific disciplines, including analytical chemistry and biomedicine, as well as in chemico, in vitro and in silico toxicology. Recent data suggest that fragrance components may exert multiple adverse biological effects, e.g. cytotoxicity, skin sensitisation, (photo)genotoxicity, mutagenicity, reprotoxicity and endocrine disruption. Therefore, a pilot study was conducted with selected samples of fragrance-based products, such as deodorant, eau de toilette and eau de parfum, with the aim of integrating results from a number of alternative non-animal methods suitable for the detection of the following toxicological endpoints: cytotoxicity (with 3T3 Balb/c fibroblasts); skin sensitisation potential (in chemico method, DPRA); skin sensitisation potential (LuSens in vitro method, based on human keratinocytes); genotoxicity potential (in vitro Comet assay with 3T3 Balb/c cells); and endocrine disruption (in vitro YES/YAS assay). The presence of twenty-four specific known allergens in the products was determined by using GC-MS/MS. The strategies for estimation of the NOAEL of a mixture of allergens, which were proposed by the Scientific Committee on Consumer Products in their 'Opinion on Tea tree oil' document and by the Norwegian Food Safety Authority in their 'Risk Profile of Tea tree oil' report, were used as models for the NOAEL estimation of the mixtures of allergens that were identified in the individual samples tested in this study.

Low-cost and prototype-friendly method for biocompatible encapsulation of implantable electronics with epoxy overmolding, hermetic feedthroughs and P3HT coating

The research of novel implantable medical devices is one of the most attractive, yet complex areas in the biomedical field. The design and development of sufficiently small devices working in an in vivo environment is challenging but successful encapsulation of such devices is even more so. Industry-standard methods using glass and titanium are too expensive and tedious, and epoxy or silicone encapsulation is prone to water ingress with cable feedthroughs being the most frequent point of failure. This paper describes a universal and straightforward method for reliable encapsulation of circuit boards that achieves ISO10993 compliance. A two-part PVDF mold was machined using a conventional 3-axis machining center. Then, the circuit board with a hermetic feedthrough was placed in the mold and epoxy resin was injected into the mold under pressure to fill the cavity. Finally, the biocompatibility was further enhanced with an inert P3HT polymer coating which can be easily formulated into an ink. The biocompatibility of the encapsulants was assessed according to ISO10993. The endurance of the presented solution compared to silicone potting and epoxy potting was assessed by submersion in phosphate-buffered saline solution at 37 °C. The proposed method showed superior results to PDMS and simple epoxy potting.

Sensitization potential of medical devices detected by in vitro and in vivo methods

Medical devices must be tested before marketing in accordance with ISO EN 10993-10 in order to avoid skin sensi­tization. This standard predominantly refers to the in vivo test but does not exclude the use of in vitro methods that have been sufficiently technically and scientifically validated for medical device testing. It is foreseen that, due to the complexity of the sensitization endpoint, a combination of several methods will be needed to address all key events occurring in the sensitization process. The objective of this pilot study was to evaluate the sensitization potential of selected medical devices using a combination of in chemico (DPRA, OECD TG 442C) and in vitro (LuSens, OECD TG 442D) methods in comparison with the in vivo (LLNA DA, OECD TG 442A) method and to suggest a possible testing strategy for the safety assessment of medical device extracts. Overall, one of the 42 tested samples exhibited positive results in all employed test methods, while 33 samples were predicted as non-sensitizing in all three performed methods. This study demonstrated good agreement between in vitro and in vivo results regarding non-sensitizing samples; however, some discrepancies in positive classification were recorded. A testing strategy is suggested in which negative results are accepted and any positive results in the in chemico or in vitro tests are followed up with a third in vitro test and evaluated in accordance with the “2 out of 3 approach”. This strategy may reduce and replace animal use for testing the sensitization potential of medical devices.

Comparison of methods used for evaluation of mutagenicity/genotoxicity of model chemicals - parabens

Growing worldwide efforts to replace (reduce) animal testing and to improve alternative in vitro tests which may be more efficient in terms of both time, cost and scientific validity include also genotoxicity/mutagenicity endpoints. The aim of the review article was to summarize currently available in vitro testing approaches in this field, their regulatory acceptance and recommended combinations for classification of chemicals. A study using the combination of Comet Assay performed on two cell lines and the Chromosomal Aberration test on human peripheral lymphocytes was performed with the aim to predict the genotoxic potential of selected paraben esters, serving as a model chemical group. Parabens are widely used in consumer products as preservatives and have been reported to exhibit inconclusive results in numerous genotoxicity studies. The Comet Assay identified Ethylparaben and Benzylparaben as potentially genotoxic. The Chromosomal Aberration test revealed weak genotoxic potential in case of Ethylparaben and positive genotoxicity in case of Butylparaben, Propylparaben and Isopropylparaben. The main reasons for variability seem to be limited water solubility of parabens, determining their bioavailability at the cellular level, and absence of metabolic activation in the Comet Assay. The results confirmed that the Comet Assay should serve as a screening test and should not be used as a stand-alone method for classification of genotoxicity. The weight of evidence approach in risk assessment should be supported with data generated with the use of human relevant in vitro methods based on cells / tissues of human origin.

Toxicological testing of a photoactive phthalocyanine-based antimicrobial substance

The aim of the study was toxicological testing of an innovative and efficient antimicrobial agent based on photoactive phthalocyanine (Pc) derivative. A promising Aluminium phthalocyanine (AlPc) with efficient and stable antimicrobial effects was subjected to a battery of toxicological tests to avoid local and systemic toxicity hazard. In compliance with the current European legislation restricting the use of experimental animals, the methods comprised exclusively in vitro procedures based on cellular and tissue models of human origin or mimicking human tissues. The battery of toxicological tests to identify local toxicity included skin corrosion/irritation, eye irritation, and phototoxicity. The basic systemic toxicity tests included acute toxicity, skin sensitization, genotoxicity, and endocrine disruption. The results showed that AlPc induced skin and eye irritation, exhibited borderline sensitization potential and mutagenic potential in one test strain of the Ames test, which was not confirmed in the chromosome aberration test. The AlPc was found to be phototoxic. The results from the cytotoxicity test designed for acute oral toxicity estimation were not conclusive, the acute toxicity potential has to be determined by conventional tests in vivo. Regarding endocrine disruption, no agonistic activity of the AlPc on human estrogen receptor α, nor human androgen receptor was observed. The skin penetration/absorption test revealed that the AlPc has not penetrated into the dermis and receptor fluid, confirming no risk of systemic exposure via the bloodstream.

Advanced characterization of natural biofilm on nanofiber scaffold

Nanofiber scaffolds provide numerous advantages over common carriers engineered for microorganisms. The most important advantage is an increased speed of primary surface colonization (up to four times faster), which shortens the time required for the areal biofilm formation and optimum performance of attached microorganisms (higher efficiency of biological activity of up to twice as fast). Image analysis predicts early formation of biofilm even in beginning stages; analysis of biofilm reveals the different structures of bacterial colonies on both scaffolds (higher porosity, size, and number of bacterial colonies on nanofiber’s surface). The image analysis correlates well with determinations of dry matter (linear correlation of 0.96) and proteins (linear correlation of 0.89).

Diagnostic value of serum galactomannan, (1,3)-β-d-glucan, and Aspergillus fumigatus-specific IgA and IgG assays for invasive pulmonary aspergillosis in non-neutropenic patients

Detection of serum galactomannan (GM) and (1,3)-β-d-glucan (BG) is considered useful for non-culture diagnosis of invasive pulmonary aspergillosis (IPA) in neutropenic patients. Only few studies evaluated these seromarkers in non-neutropenic patients suspected of having IPA. The aim of this study was to evaluate both tests together with the Aspergillus fumigatus-specific serum IgG and IgA (IgAG) test for serological IPA diagnosis in non-neutropenic patients. Sera from 87 patients suspected of having IPA were retrospectively analysed. Patients were categorised into groups of proven IPA (n = 10), putative IPA (n = 31) and non-IPA colonisation (n = 46). When the GM, BG and IgAG assays were used for patients included in the study, the sensitivity/specificity/positive predictive value (PPV)/negative predictive value (NPV) were 48.8%/91.3%/83.3%/66.7%, 82.9%/73.9%/73.9%/82.9% and 75.6%/95.7%/93.9%/81.5%, respectively. Thus, the highest specificity and PPV were confirmed for the IgAG assay. Improvements in the sensitivity and NPV were achieved by "at least one positive" analysis with the GM and BG assays, with the sensitivity/specificity/PPV/NPV values being 85.0%/69.6%/71.4%/84.2%. Nevertheless, the highest sensitivity and NPV were achieved by the "at least one positive" analysis combining the GM, BG and IgAG tests (97.6% and 96.8%, respectively). The involvement of the IgAG assay could improve IPA diagnosis in non-neutropenic patients by increasing the sensitivity and NPV when combined with the GM or BG assays. Furthermore, improvement was achieved by combining the GM, BG and IgAG assays using the "at least one positive test" strategy, especially if doubt exists.

Nosocomial candidemia in the Czech Republic in 2012-2015: results of a microbiological multicentre study

  Background: Candidemia is a severe and often life-threatening infection frequently occurring in critically ill patients. During the last decade, new therapeutic and prophylactic strategies influenced (at least in some patient subgroups) the epidemiological situation and the spectrum of causative Candida strains. The present multicentre study aimed to assess the current epidemiological situation of Candida strains causing invasive candidiasis (IC) in patients of tertiary care hospitals in the Czech Republic.

MATERIAL AND METHODS

Clinical and microbiological data on patients with bloodstream yeast isolates collected in 11 tertiary care hospitals in the Czech Republic between 2012 and 2015 were analysed. The incidence of cases and species distribution were assessed by study year, age, and specialty. Moreover, an association with the Candida colonization and presence of toxigenic strains of Clostridium difficile in stool prior to blood culture positivity was analysed. For some of the strains, minimum inhibitory concentrations (MICs) of systemic antifungals were determined using standard methods.

RESULTS

A total of 886 episodes of candidemia (921 yeast strains) were identified during the study period. The overall incidence per 1000 admissions was 0.40 (range 0.21-1.22 depending on the hospital). Almost half of the isolates belonged to the species Candida albicans (49.7 %), followed by Candida glabrata (15.3 %) and Candida parapsilosis (11.2 %). Non-albicans species of Candida significantly predominated in oncology wards (71.6 %) as compared to surgery (40.4 %) or internal medicine (52.0 %) departments. More than 70.0 % of patients stayed in intensive care units at the time of positive culture; in 65.0 % of patients, colonization with the same yeast species preceded blood culture positivity. In only 5.1 % of all patients, the previous presence of toxigenic strains of Clostridium difficile in stool was found. Fifty-six of the 921 yeast strains were tested for antifungal susceptibility, with an increase in MICs to azoles being observed for C. glabrata.

CONCLUSION

The incidence of candidemia in the Czech Republic did not vary significantly between 2012 and 2015, and C. glabrata was the second most common yeast species after C. albicans isolated from blood.

[The prevalence of Candida pelliculosa, Candida utilis, and Candida fabianii in the Olomouc University Hospital: epidemiological study]

BACKGROUND

The aims of this study were to determine the prevalence of C. pelliculosa, C. utilis, and C. fabianii in clinical samples collected from patients hospitalized in the Olomouc University Hospital and compare their minimum inhibitory concentrations (MICs ) to nine systemic antifungals with respect to yeast species, patient age, gender, and site of infection.

MATERIAL AND METHODS

Identification was performed biochemically and using mass spectrometry (MALDI-TOF MS). MICs were determined by the broth dilution method.

RESULTS

Of a total of 163 clinical isolates, 119 were biochemically identified as C. pelliculosa and 44 as C. utilis. Using MALDI-TOF MS, 152 isolates were identified as C. fabianii, six as C. pelliculosa, three as C. utilis, and one as Ogataea polymorpha. The highest mean MICs were found in C. fabianii and in yeasts isolated from blood cultures and central venous catheters.

CONCLUSIONS

The MALDI-TOF MS found C. fabianii to be most prevalent in clinical samples as compared with the other studied species. The probable cause of discordant results between the two methods was the absence of C. fabianii in the database of the biochemical test kit which led to misidentification of this species. Higher MIC values in C. fabianii demonstrate the importance of the precise identification of this species.

The study of surface properties of an IgE-sensitive aptasensor using an acoustic method

We applied the acoustic transverse shear mode (TSM) method for study of the surface properties of a DNA aptasensor that specifically binds human immunoglobulin E (IgE). The biotinylated 45-mer DNA aptamers were immobilized on the surface of a self-assembled layer composed of a mixture of polyamidoamine dendrimers of the fourth generation with 1-hexadecanetiol covered by neutravidin. Using the TSM method, we studied the kinetics of changes of the series resonant frequency, f(s), and the motional resistance, R(m), of a quartz crystal transducer, used as a support for formation of the sensing layer. We have shown that attachment of the biotinylated DNA aptamers onto the surface covered by neutravidin results in a decrease of f(s), but in an increase of R(m). Similar changes of f(s) and R(m) were observed following addition of IgE. This suggests the contribution of friction forces to the crystal oscillation, which was taken into account in the calculation of the mass changes at the sensor surface following binding processes.

[Cryptogenic fibrotizing alveolitis]

Presented article deals with the pathogenesis of cryptogenic fibrotizing alveolitis (CFA), gives distinct histological types according ATS and ERS, considers clinical CFA picture and recommends examination program for this disease. The anti-inflammatory and immunosuppressive treatment is discussed together with other therapeutic approaches (long-lasting oxygenotherapy at home, transplantation and treatment of pulmonary hypertension). Final part deals with less frequent clinical manifestations.

[Tuberculosis in the Czech Republic]

Tuberculosis is a general infectious inflammatory disease caused by the bacillus (mycobacterium) tuberculosis. The disease originated when the bacillus was transmitted from affected cattle herds to humans. Genetic methods proved the existence of tuberculosis in mummies of the ancient Egypt. In the 19th and 20th century socio-economic conditions enabled pandemics of tuberculosis. The essential element for spreading of tuberculosis is the tuberculous patient. The disease develops in 10% of those who were infected. Tuberculosis manifests by long-lasting coughing, night sweating, tiredness, growing slim, febriles and loss of appetite. Diagnosis can be established on the basis of thoracic sciagram, confirmed by microscopic and cultivation examination of sputum. In the Czech Republic, an effective surveillance of tuberculosis was established with resulting good epidemiological situation.

Properties of mixed alkanethiol-dendrimer layers and their applications in biosensing

We studied the properties of mixed alkanethiol-dendrimer layers on a gold support and their application in biosensing. We showed that properties of glucose sensor can be modified using a different ratio of 1-hexadecanethiol (HDT) and poly(amidoamine) dendrimer of first generation (G1). The cyclic voltammetry in the presence of the redox couple, Fe(CN)(6)(3-)/Fe(CN)(6)(4-), was used for estimating how effectively the layer blocks the redox probe's access to the electrode surface. A scanning electrochemical microscope (SECM) was used to image the resulting distribution of the organic compounds. We found that with increasing content of dendrimers, the integrity of the layers was improved.

Activation and modulation of ligand-gated ion channels

Ligand-gated ionic channels are integral membrane proteins that enable rapid and selective ion fluxes across biological membranes. In excitable cells, their role is crucial for generation and propagation of electrical signals. This survey describes recent results from studies performed in the Department of Cellular Neurophysiology, Institute of Physiology ASCR, aimed at exploring the conformational dynamics of the acetylcholine, glutamate and vanilloid receptors during their activation, inactivation and desensitization. Distinct families of ion channels were selected to illustrate a rich complexity of the functional states and conformational transitions these proteins undergo. Particular attention is focused on structure-function studies and allosteric modulation of their activity. Comprehension of the fundamental principles of mechanisms involved in the operation of ligand-gated ion channels at the cellular and molecular level is an essential prerequisite for gaining an insight into the pathogenesis of many psychiatric and neurological disorders and for efficient development of novel specifically targeted drugs.

Effects of oxidation on changes of compressibility of bovine serum albumin

The methods of ultrasound velocity and density measurements were used to study the adiabatic compressibility of bovine serum albumin (BSA) during its oxidation by the prooxidants Cu2+ and 2,2'-azobis(2-amidinopropane) hydrochloride (AAPH). We did not find changes of compressibility of BSA in the presence of copper ions at rather high molar ratio Cu2+/BSA = 0.66 mol/mol. This can be explained by binding of the Cu2+ to the binding site of BSA and thus protecting the prooxidant action of the copper. However, AAPH-mediated oxidation of BSA resulted in an increase of its apparent specific compressibility (psik/beta0). These changes could be caused by the fragmentation of the protein.

[Lymphangioleiomyomatosis in a menopausal woman]

Lymphagioleiomyomatosis is a rare pulmonary disease which affects mainly women of childbearing age. An observation of lymphangiomyomatosis in a menopausal woman or in men is considered very unusual. We report a case of lymphagioleiomyomatosis in a 60-year-old woman.

[Interstitial pulmonary processes]

New classification of the idiopathic interstitial pneumonias on the basis of the structural characteristics is presented. The contemporary classification includes four types of disease, differing in the clinical symptomatology, reaction to therapy and prognosis.

Properties of glucose biosensors based on dendrimer layers. Effect of enzyme immobilization

The properties of glucose biosensors based on dendrimer layers on a gold support, which depend on the method of immobilization of glucose oxidase (GOX), were studied by amperometry. The kinetic parameters of enzymatic reactions, response time, sensitivity, detection limit, linear range, and enzyme turnover were determined. We showed that a more stable and sensitive sensor was obtained when GOX was immobilized on the dendrimer by crosslinking with glutaraldehyde in vacuum. This biosensor was stable for at least eight weeks. The response time was approximately 1.3 min, the detection limit of glucose was 25 micro M, and the apparent Michaelis-Menten constant was relative low ( K(m)=1.1+/-0.1 mM) in comparison with that for GOX in solution. The reason for these differences is discussed. The example of the application of the developed biosensors for the detection of mercury is also presented. The inhibitory effect of mercury on GOX activity was observed at mercury concentration of 100 nM.

Liposome aggregation in presence of the sweeteners cyclamate and saccharine

The interaction of the sweeteners saccharine and cyclamate with large unilamellar liposomes and planar bilayer lipid membranes (BLM) was studied. Application of the methods of light scattering and sound velocimetry showed that saccharine induces aggregation of liposomes, while cyclamate probably caused increase of the hydration of liposome surface. The sweeteners induced changes of BLM compressibility in a direction perpendicular to the membrane plane. The cyclamate induced considerably larger decreases in the elasticity module than saccharine. The obtained results show that both saccharine and cyclamate interacts with the surface of lipid bilayer and could modify the physical properties of lipid membranes.

[High-resolution computer tomography in the diagnosis of cryptogenic fibrosing alveolitis. Correlation with pulmonary function and bronchoalveolar lavage]

BACKGROUND

High resolution computed tomography (HRCT) revealed new findings as regards changes associated with cryptogenic fibrotizing alveolitis. So far views on changes suggesting activity of the disease are not uniform and they were not yet confronted with examinations of fluid obtained by bronchoalveolar lavage (BALT). The objective of the present work is to evaluate the contribution of HRCT to the assessment of the activity of the disease and compare the findings with the examination of BALT.

METHODS AND RESULTS

The authors evaluated the HRCT examination made in 52 patients with histologically confirmed cryptogenic fibrotizing alveolitis and in 39 of them the finding was confronted with the BALT examination. Signs of active inflammatory disease according to HRCT comprised a ground-glass increase of the density in 80.8%, centrilobular micronodules in 17.3% and a prominence of centrilobular structures in 32.7%. The suggested extent of affection of the pulmonary parenchyma assessed according to HRCT correlated well with the degree of dyspnoea, restrictive and obstructive ventilation disorder, pulmonary diffusion and with hypoxaemia. The authors confirmed also an inverse correlation between the grade assessed by HRCT and the percentage of lymphocytes in BALT.

CONCLUSIONS

The investigation confirmed the contribution of HRCT in the diagnosis of patients with cryptogenic fibrotizing alveolitis, it confirmed the complementary importance of HRCT and BALT examination when assessing the activity of the disease and its asset when monitoring patients during treatment.

[The clinical picture of pulmonary tuberculosis over the past 40 years]

Most patients with pulmonary tuberculosis present to their physician because of the symptoms of this disease. This study was aimed at finding out how the clinical picture of pulmonary tuberculosis diagnosed for the first time changes in the patients hospitalized at our department in the years 1948-1986. Furthermore, the percentage of asymptomatic patients, the frequency of detectable cavern and mycobacteria tuberculosis were established. During the time period studied a change in clinical picture of the disease occurred as seen on the 13 symptoms followed. The previously common haemoptysis is a rarer symptom of tuberculosis at present (17.5% in the 1948-1950 population compared to 5.0% in the 1983-1986 population). There is an increasing number of patients in which tuberculosis manifests itself by breathlessness (2.3% of the 1948-1950 population compared to 10.9% in the years 1979-1981). In the whole period studied patients with symptoms prevail, the difference between the 1948-1950 period (71.1%) and that of 1979-1986 (67.0%) is not statistically significant. The number of patients with cavernous tuberculosis is decreasing (75% of patients in the years 1948-1950, 37% of patients in the years 1983-1986), there is an increase in bacteriologically proven diseases (33.9% of the 1948-1950 population, 73.0% of that of 1983-1986). The change in the clinical picture of tuberculosis is connected with the improvement of social conditions of the whole population, introduction of compulsory BCG vaccination and effective therapy, as well as bovine tuberculosis elimination. The change in the clinical picture of the disease is also influenced by the ever increasing mean age of the patients.