Interactions of Engineered Nanoparticles with Organs Protected by Internal Biological Barriers

Engineered nanomaterials may exert adverse effects on human health which, in turn, may be linked to their propensity to cross biological barriers in the body. Here, we will discuss available evidence based on in vivo studies for interactions of commercially relevant nanoparticles with critical internal barriers. The internal barriers at focus of this review are the blood-brain barrier (BBB), protecting the brain, the blood-testis barrier (BTB), protecting the male germ line, and the placenta, protecting the developing fetus. The route of exposure (pulmonary, gastrointestinal, intravenous, intraperitoneal, dermal), and the portal of entry of nanoparticles into the body, is of critical importance. Different physico-chemical properties, not only size, may determine the ability of nanoparticles to breach biological barriers; the situation is further compounded by the formation of a so-called corona of biomolecules on the surface of nanoparticles, the composition of which may vary depending on the route of exposure and the “history” of the nanoparticles as they translocate from one biological compartment to another. The relevance of nanoparticle interactions with internal biological barriers for their impact on the organs protected by these barriers is discussed

Physico-Chemical Properties Mediating Reproductive and Developmental Toxicity of Engineered Nanomaterials

With the increasing production of engineered nanomaterials (ENMs) exploited in many consumer products, a wider number of people is expected to be exposed to such materials in the near future, both in occupational and environmentalsettings. This has raised concerns about the possible implications on public health. In particular, very recently the scientific community has focused on the effect that ENMs might exert on the reproductive apparatus and on embryonic development. Indications that ENMs might have adverse effects on cells of the germ line and on the developing embryos have been reported. In the present minireview we will perform a critical analysis of the published work on reproductive and developmental toxicity of the most commonly used nanoparticles with a major focus on mammalian models. We will place emphasis on the main physico-chemical characteristics that can affect NP behaviour in biological systems, i.e. presence of contaminants and nanoparticle destabilization, size, dosage, presence of functional groups, influence of the solvent used for their suspension in biological media, aggregation/agglomeration, intrinsic chemical composition and protein corona/opsonisation. The importance of this specific field of nanotoxicology is documented by the rapidly increasing number of published papers registered in the last three years, which might be a consequence of the growing concerns on the possible interference of ENMs with reproductive ability and pregnancy outcome, in a time in which reproductive age has increased and the possibility to bear children appears reduced

Elemental analysis of histological specimens: A method to unmask nano asbestos fibers

There is recent mounting evidence that nanoparticles may have enhanced toxicological potential in comparison to the same material in the bulk form. The aim of this study was to develop a new method for unmask asbestos nanofibers from Formalin-Fixed, Paraffin-Embedded tissue. There is an increasing amount of evidence that nanoparticles may enhance toxicological potential in comparison to the same material in the bulk form. The aim of this study was to develop a new method to unmask asbestos nanofibers from Formalin-Fixed Paraffin-Embedded (FFPE) tissue. For the first time, in this study we applied Energy Dispersive X-ray (EDX) microanalysis through transmission electron microscopy to demonstrate the presence of asbestos nanofibers in histological specimens of patients with possible occupational exposure to asbestos. The diagnostic protocol was applied to 10 randomly selected lung cancer patients with no history of previous asbestos exposure. We detected asbestos nanofibers in close contact with lung cancer cells in two lung cancer patients with previous possible occupational exposure to asbestos. We were also able to identify the specific asbestos iso-type, which in one of the cases was the same rare variety used in the workplace of the affected patient. By contrast, asbestos nanofibers were not detected in lung cancer patients with no history of occupational asbestos exposure. The proposed technique can represent a potential useful tool for linking the disease to previous workplace exposure in uncertain cases. Furthermore, Formalin-Fixed Paraffin-Embedded (FFPE) tissues stored in the pathology departments might be re-evaluated for possible etiological attribution to asbestos in the case of plausible exposure. Since diseases acquired through occupational exposure to asbestos are generally covered by workers' insurance in most countries, the application of the protocol used in this study may have also relevant social and economic implications

Monthly fluctuations in 25-hydroxy-vitamin D levels in day and rotating night shift hospital workers

Purpose Epidemiological studies have suggested that indoor hospital employees, either day or night shift workers, are at high risk of metabolic and cardiovascular diseases. Interestingly, previous reports have also described a higher prevalence of vitamin D (25OHD) deficiency among these workers. However, few studies have determined the monthly variations in 25OHD levels in indoor hospital employees. Methods To address this lack of knowledge, in 2018, during the periodic health surveillance checks at the Service of Occupational Medicine, we measured 25OHD levels in a group of indoor hospital workers (88 rotating night shift workers vs 200 day workers). Each participant received a single annual health surveillance check. Results The mean levels of 25OHD were consistently below the lower limit of the normal range in both groups throughout the year. Only in the summer, day workers but not rotating night shift workers (mean 25.9 +/- 11.3 ng/ml vs 23.1 +/- 9.1 ng/ml; p = 0.042) showed levels significantly higher than those in the other seasons. This difference remained statistically significant even after correction for study covariates [beta = - 1.649 (CI - 0.283/- 3.482), p = 0.039]. A cosinor analysis confirmed that the difference in the 25OHD levels between groups was present later in the year. Conclusions We found that relatively young healthy hospital workers, especially those with rotating night shifts, in the absence of significant metabolic risk factors, have a high risk of 25OHD deficiency/insufficiency. Because 25OHD deficiency may lead to a progression to more severe conditions such as osteoporosis or bone fractures, our results should be verified in larger cohorts including different ancestries

Severe facial reaction to thiurams in surgeons

Contact dermatitis is a major problem in the healthcare environment and in other sectors. Healthcare professionals may be exposed to a large number of chemical agents, including the accelerators for rubber vulcanization process. The prevalence of allergic contact dermatitis among operators in the sector ranges 13–30%. This paper describes the case of a 46-year-old male cardiac surgeon affected by a severe skin reaction localized on the face in the absence of hand dermatitis, presumably resulting from the use of a surgical patch applied to the face. Patch tests were performed and the result was negative for latex and positive (+++) for thiuram mix. A thiuram-free tape was prescribed and the operator's dermatitis improved significantly. Thus, it would be very important to pay attention to skin disorders in health workers and thiuram as an occupational allergen. Med Pr. 2019;70(1):121–

Changes in Cardiac Autonomic Regulation after Acute Lung Exposure to Carbon Nanotubes: Implications for Occupational Exposure

Carbon nanotubes (CNTs) are among the most relevant engineered nanomaterials (ENMs). Given the expected rise of exposure to ENMs, there is concern that they may adversely affect health of exposed people. Aim of the study was to test the hypothesis that single wall carbon nanotubes (SWCNTs) pulmonary exposure acutely affect the autonomic cardiovascular regulation in conscious rats. We studied Wistar-Kyoto rats in which a telemetry transmitter for continuous arterial pressure (AP) and heart rate (HR) recordings was surgically implanted. SWCNTs dispersed in phosphate buffer saline (PBS) or PBS alone were randomly administered intratracheally. Immediately before, and 24 hours after each instillation a 30 min AP recording was performed. The sequence analysis was performed to evaluate the baroreflex function. In the control group, PBS instillation did not induce any significant changes. At variance the SWCNT exposure induced a significant reduction of baroreflex system (BRS) (3.5 \ub1 0.6 versus 2.6 \ub1 0.40\u2009msec/mmHg) without significant changes in the occurrence of baroreflex sequences (7.5 \ub1 0.47 % versus 7.4 \ub1 0.38 %). Our results show that SWCNT pulmonary exposure might affect the cardiovascular autonomic regulation thus contributing to cardiac and arrhythmic events

Silica encapsulation of ZnO nanoparticles reduces their toxicity for cumulus cell-oocyte-complex expansion

Background Metal oxide nanoparticles (NPs) are increasingly used in many industrial and biomedical applications, hence their impact on occupational and public health has become a concern. In recent years, interest on the effect that exposure to NPs may exert on human reproduction has grown, however data are still scant. In the present work, we investigated whether different metal oxide NPs interfere with mouse cumulus cell-oocyte complex (COC) expansion. Methods Mouse COCs from pre-ovulatory follicles were cultured in vitro in the presence of various concentrations of two types of TiO2 NPs (JRC NM-103 and NM-104) and four types of ZnO NPs (JRC NM-110, NM-111, and in-house prepared uncoated and SiO2-coated NPs) and the organization of a muco-elastic extracellular matrix by cumulus cells during the process named cumulus expansion was investigated. Results We show that COC expansion was not affected by the presence of both types of TiO2 NPs at all tested doses, while ZnO NM-110 and NM-111 induced strong toxicity and inhibited COCs expansion at relatively low concentration. Medium conditioned by these NPs showed lower toxicity, suggesting that, beside ion release, inhibition of COC expansion also depends on NPs per se. To further elucidate this, we compared COC expansion in the presence of uncoated or SiO2-coated NPs. Differently from the uncoated NPs, SiO2-coated NPs underwent slower dissolution, were not internalized by the cells, and showed an overall lower toxicity. Gene expression analysis demonstrated that ZnO NPs, but not SiO2-coated ZnO NPs, affected the expression of genes fundamental for COC expansion. Dosimetry analysis revealed that the delivered-to-cell mass fractions for both NPs was very low. Conclusions Altogether, these results suggest that chemical composition, dissolution, and cell internalization are all responsible for the adverse effects of the tested NPs and support the importance of a tailored, safer-by-design production of NPs to reduce toxicity

Language Usage Conditions of Multilingual Nations - Sri Lanka“Sinhalese native speakers and Tamil native speakers\u27 scenes, their word usage conditions in Western Province and Uva Province .

Sri Lanka is a multilingual nation, where various languages, races, and religions exist. Sinhalese, Muslims and Tamils reside together with Burger, Marais and native people called ‘Veddah\u27. Sri Lankan people use three languages; Sinhala, English, and Tamil in their daily communication. To examine the language situation in Sri Lanka means to analyze the cultural and social circumstances within Sri Lanka.In particular the Code Switching (CS) is seen in various situations in Sri Lanka. It is expected that a person would switch the language code depending on the situation. This also differs according to various circumstances such as speaker\u27s life style and living conditions at home, academic background and the social hierarchy. Furthermore, it is estimated that differences in CS between Tamil minority and Sinhala majority would exist. It is important to consider these points in order to examine the situation of communication. English is also used quite often in Sri Lanka. The influence and the necessity of English would be examined through a survey of English usage spreading in the real world.The questionnaire style survey has been conducted and it was administered based on pilot research in Japan. It is necessary to investigate various circumstances that people face in order to examine the true language usage conditions. The investigation considered people in various places and situations throughout Sri Lanka.Sri Lanka consists of nine states. The research was done in eight states: Central Province, Eastern Province, Northern Province, Southern Province, Western Province North western Province, Uva Province and Sabaragamuwa province.The research was done as follows:The locations : at a house of a standard family, at a bank, at a school and at a postoffice in each locations.The subjects : 525 people including students, office workers, house-wives, farmers,and elderly people.The format of investigation: The questionnaire included four communication situations and questionsIn this paper, the language usage conditions of Sinhalese native speakers and the Tamil native speakers of both Western Province and Uva Province are analyzed in various situations. As the result, the Sinhalese native speakers in Western Province showed many examples of code switching between Sinhalese and English. Moreover, English code switching was seen frequently in the home.When considering the Uva Province, the Sinhalese native speakers use both Sinhala and English while a significant proportion of them are trilingual speakers there. They often change between the three main languages; Sinhala, English and Tamil are used quite often at schools, offices, hospitals, and so on.To examine a number of communication scenes in different language groups in Sri Lanka, it was clearly seen that there are more trilingual speakers among Tamil native speakers who more likely to switch between three languages in different situations, while Sinhalese speakers switch between two languages. The data of the survey also showed that the usage of languages varies according to the speakers\u27 social status, region where he or she lives, academic background, age, etc.Moreover, when the communication is taking place at home, the Sinhalese native speakers often use the code switching between Sinhalese and English. However, the elderly people in Sri Lanka, especially people living in Uva Province, rarely speak English due to their poor academic background.It has become clear that the language usage conditions differ from one another depending on the society, the region, and the educational level, and age of the person in Sri Lanka.However it is not well known yet when and how the code switching happens. As for code switching between English and Sinhalese, it is important to record their natural conversation in various scenes to analyze certain characteristics of the code switching. This would help clarify how Sri Lankans use these languages.千葉大学大学院人文社会科学研究科研究プロジェクト報告書第239集「ユーラシアの多言語社会と言語政策」中川裕 編Eurasian Multilingual Society and Language Policy Report on Research Project No.23