Aluminium and breast cancer: Sources of exposure, tissue measurements and mechanisms of toxicological actions on breast biology

Use of Antiperspirant Products and Risk of Breast Cancer: A Meta-Analysis of Case-Control Studies

Although several observational studies have reported a link between the use of underarm cosmetic products and the risk of breast cancer, the findings remain inconsistent. This study aimed to investigate these associations using a meta-analysis of observational studies. In the meta-analysis of seven case-control studies, we found no association between the use of underarm antiperspirants or deodorants and the risk of breast cancer (OR = 0.96, 95%CI 0.78-1.17; I2 = 60.0%). Further prospective cohort studies that provide a higher level of evidence are warranted to confirm our findings.

Aluminum and ABC transporter activity

Aluminum is the third most common element on Earth´s crust and despite its wide use in our workaday life it has been associated with several health risks after overexposure. In the present study the impact of aluminum salts upon ABC transporter activity was studied in the P-GP-expressing human blood-brain barrier cell line hCMEC/D3, in MDCKII cells overexpressing BCRP and MRP2, respectively, and in freshly isolated, functionally intact kidney tubules from Atlantic killifish (Fundulus heteroclitus), which express the analog ABC transporters, P-gp, Bcrp and Mrp2. In contrast to previous findings with heavy metals salts (cadmium(II) chloride or mercury(II) chloride), which have a strong inhibitory effect on ABC transporter activity, or zinc(II) chloride and sodium arsenite, which have a stimulatory effect upon ABC transport function, the results indicate no modulatory effect of aluminum salts on the efflux activity of the human ABC transporters P-GP, BCRP and MRP2 nor on the analog transporters P-gp, Bcrp and Mrp2.

Development of a water-soluble fluorescent Al3+ probe based on phenylsulfonyl-2-pyrone in biological systems

BACKGROUND

Al exists naturally in the environment and is an important component in acidic soils, which harm almost all plants. Furthermore, Al is widely used in food additives, cosmetics, and medicines, resulting in living organisms ingesting traces of Al orally or dermally every day. Accordingly, Al accumulates in the body, which can cause negative bioeffects and diseases, and this concern is gaining increasing attention. Therefore, to detect and track Al in the environment and in living organisms, the development of novel Al-selective probes that are water-soluble and exhibit fluorescence at long wavelengths is necessary.

RESULTS

In this study, an Al3+-selective fluorescent probe PSP based on a novel pyrone molecule was synthesized and characterized to detect and track Al in biological systems. PSP exhibited fluorescence enhancement at 580 nm in the presence of Al3+ in aqueous media. Binding analysis using Job's plot and structural analysis using 1H NMR showed that PSP formed a 1:1 complex with Al3+ at the two carbonyl groups of the dimethyl malonate of the pyrone ring. Upon testing in biological systems, PSP showed good cell membrane permeability, detected intracellular Al3+ in human breast cancer cells (MDA-MB-231), and successfully imaged accumulated Al3+ in Microcystis aeruginosa and the larvae of Rheocricotopus species.

SIGNIFICANCE

The novel Al3+-selective fluorescent probe PSP is highly effective and is expected to aid in elucidating the role of Al3+ in the environment and living organisms.

A zwitterionic probe for ratiometric fluorescent detection of aluminium(III) ion in aqueous medium and its application in bioimaging

In the present study, we have synthesized an aminobenzoic acid containing Schiff base (compound 1) and its structure was confirmed through single crystal X-ray study. Importantly, the compound 1 crystallizes in the zwitterionic form, with an anionic carboxylate group (-COO-) and a cationic iminium group (-C = NH+-). The compound 1 is highly soluble in water due to its zwitterionic feature in the solid state. Interestingly, compound 1 acts as a ratiometric fluorescent probe for the selective detection of Al3+ ion in aqueous solution without organic cosolvent. It can also detect Al3+ ion by visual colour change to bluish-green fluorescence under 365 nm UV light. The association constant between compound 1 with Al3+ ion was estimated to be 1.67 × 104 M-1. The lowest detection limit for Al3+ ion was calculated to be 7.05 × 10-8 M in water. Compound 1 in combination with Al3+ ion demonstrated fluorescent imaging potential of the nucleus of in RAW 264.7 murine macrophage cell line. In addition, the sensing model is developed as paper based sensor ''Test Kit' 'for its practical applicability.

Correlation between daily life aluminium exposure and breast cancer risk: A systematic review

BACKGROUND

Epidemiological data indicate that the role of environmental factors on breast cancer (BC) incidence remains undetermined. Our daily life exposure to aluminium (Al) is suspected to influence BC development. This review proposes a state of the art on the association between Al and BC risk combined with a critical point of view on the subject.

METHODS

We searched the PubMed database using terms related to Al and BC up to November 18, 2022. Reports were eligible if they were cohort or case-control studies or meta-analyses.

FINDINGS

Six studies focused on the relationship between deodorant and antiperspirant use and BC incidence and didn't produce consistent results. Among 13 studies relating Al content in mammary tissues and BC risk, results are not unanimous to validate higher Al content in tumor tissues compared to healthy ones. We detail parameters that could explain this conclusion: the absence of statistical adjustments on BC risk factors in studies, the confusion between deodorant and antiperspirant terms, the non-assessment of global Al exposure, and the focus on Al in mammary tissues whereas a profile of several metals seems more appropriate. The clinical studies are retrospective. They were carried out on small cohorts and without a long follow-up. On the other hand, studies on cell lines have shown the carcinogenic potential of aluminum. Moreover, studies considered BC as a unique group whereas BC is a heterogeneous disease with multiple tumor subtypes determining the tumor aggressiveness.

CONCLUSION

In light of the precautionary principle and based on the data obtained, it is better to avoid antiperspirants that contain Al. Deodorants without aluminum are not implicated in breast cancer, either clinically or fundamentally.

Concentrations and predictors of aluminum, antimony, and lithium in breast milk: A repeated-measures study of donors

Aluminum (Al), antimony (Sb), and lithium (Li) are relatively common toxic metal(oid)s that can be transferred into breast milk and potentially to the nursing infant. This study assessed concentrations of Al, Sb, and Li in breast milk samples collected from donor mothers and explored the predictors of these concentrations. Two hundred forty-two pooled breast milk samples were collected at different times post-partum from 83 donors in Spain (2015-2018) and analyzed for Al, Sb, and Li concentrations. Mixed-effect linear regression was used to investigate the association of breast milk concentrations of these elements with the sociodemographic profile of the women, their dietary habits and utilization of personal care products (PCPs), the post-partum interval, and the nutritional characteristics of milk samples, among other factors. Al was detected in 94% of samples, with a median concentration of 57.63 μg/L. Sb and Li were detected in 72% and 79% of samples at median concentrations of 0.08 μg/L and 0.58 μg/L, respectively. Concentrations of Al, Sb, and Li were not associated with post-partum time. Al was positively associated with total lipid content of samples, weight change since before pregnancy, and coffee and butter intakes and inversely with meat intake. Li was positively associated with intake of chocolate and use of face cream and eyeliner and inversely with year of sample collection, egg, bread, and pasta intakes, and use of hand cream. Sb was positively associated with fatty fish, yoghurt, rice, and deep-fried food intakes and use of eyeliner and inversely with egg and cereal intakes and use of eyeshadow. This study shows that Al, Sb, and Li, especially Al, are widely present in donor breast milk samples. Their concentrations in the milk samples were most frequently associated with dietary habits but also with the lipid content of samples and the use of certain PCPs.

A new fluorescent probe for sensing Al3+ ions in the solution phase and CH3COO- in the solid state with aggregation induced emission (AIE) activity

An AIE (aggregation induced emission) active probe DFP-AMQ was designed and synthesized as a hexa-coordinated N₂O donor chelator for the selective sensing of Al³⁺ colorimetrically as well as fluorimetrically with a 27-fold fluorescence enhancement for CH₃CN-H₂O (9 : 1, v/v, pH 7.2, HEPES buffer). The fluorescence enhancement occurred through the blocking of ESIPT, chelation enhanced fluorescence effect (CHEF) arose, and as a result fluorescence enhancement was observed through 1 : 1 complexation with Al³⁺ ions. Detailed spectroscopic studies including UV-Vis, FTIR, ¹H NMR, and HRMS studies were carried out to characterize the probable structure of DFP-AMQ including the complexation of DFP-AMQ with Al³⁺ ions. The spectrophotometric and spectrofluorimetric titrations revealed strong binding towards Al³⁺ and the K _d values were obtained from UV-Vis (3.26 × 10^-5 M^-1) and fluorescence titration (2.02 × 10^-5 M^-1). The limit of detection of Al³⁺ by DFP-AMQ was 1.11 μM. The quantum yields of DFP-AMQ and [DFP-AMQ-Al]⁺ were calculated to be 0.008 and 0.211, respectively. Dynamic light scattering (DLS) studies showed that the sizes of the particles increased with increasing water percentage due to aggregation. SEM (scanning electron microscopy) studies revealed interesting morphological changes in microstructures in which DFP-AMQ demonstrated a rod-like shape, which was converted to a spherical-like shape in the presence of Al³⁺ and when DFP-AMQ aggregated in H₂O it showed aggregated block-like shape. In the solid phase, DFP-AMQ with nitrate has no particular shape, but in the presence of acetate, it converts to stone-like shape. This probe (DFP-AMQ) could be employed for on-site Al³⁺ ion detection in the solid state.

In vitro evaluation of the inhalation toxicity of the cosmetic ingredient aluminum chlorohydrate

Aluminum chlorohydrate (ACH) is a major aerosol component frequently used as the active ingredient in antiperspirants, and in vivo studies have raised a concern about its inhalation toxicity. Still, few studies have addressed its effects on the human respiratory tract. Therefore, we developed a study on ACH inhalation toxicity using an in vitro human alveolar cell model (A549 cells) with molecular and cellular markers of oxidative stress, immunotoxicity, and epigenetic changes. The chemical characterization of ACH suspensions indicated particle instability and aggregation; however, side-scatter analysis demonstrated significant particle uptake in cells exposed to ACH. Exposure of A549 cells to non-cytotoxic concentrations of ACH (0.25, 0.5, and 1 mg/ml) showed that ACH induced reactive oxygen species. Moreover, ACH upregulated TNF, IL6, IL8, and IL1A genes, but not the lncRNAs NEAT1 and MALAT1. Finally, no alterations on the global DNA methylation pattern (5-methylcytosine and 5-hydroxymethylcytosine) or the phosphorylation of histone H2AX (γ-H2AX) were observed. Our data suggest that ACH may induce oxidative stress and inflammation on alveolar cells, and A549 cells may be useful to identify cellular and molecular events that may be associated with adverse effects on the lungs. Still, further research is needed to ensure the inhalation safety of ACH.

Biphenyl Containing Amido Schiff base Derivative as a Turn-on Fluorescent Chemosensor for Al3+ and Zn2+ ions

A hydrazine derived Bis(2-hydroxybenzylidene)-[1,1'-biphenyl]-2,2'-dicarbohydrazide (sensor 1) has been synthesized and its sensing properties towards metal ions has been demonstrated using simple UV-visble spectroscopic, fluorometric technique and visible colour change. The...

Nipple Aspirate Fluid at a Glance

Simple Summary

Nipple aspirate fluid (NAF) is a promising source of markers for detection of breast cancer. NAF can be acquired via the nipple by aspiration using a suction device, which is well tolerated by women. Future possible applications of biomarkers for breast cancer derived from NAF could be (1) as a detection tool to identify the initiation of the cancer development process, (2) as an additional tool next to imaging (mammography and breast magnetic resonance imaging) or (3) as a replacement tool for when imaging is not advisable for women, such as during pregnancy and breastfeeding. With this paper, we present a narrative review and perspectives of NAF research at a glance.

Abstract

Nipple aspirate fluid (NAF) is an intraductal mammary fluid that, because of its close proximity to and origin from the tissue from which breast cancer originates, is a promising source of biomarkers for early breast cancer detection. NAF can be non-invasively acquired via the nipple by aspiration using a suction device; using oxytocin nasal spray helps increase yield and tolerability. The aspiration procedure is generally experienced as more tolerable than the currently used breast imaging techniques mammography and breast magnetic resonance imaging. Future applications of NAF-derived biomarkers include their use as a tool in the detection of breast carcinogenesis at its earliest stage (before a tumor mass can be seen by imaging), or as a supporting diagnostic tool for imaging, such as when imaging is less reliable (to rule out false positives from imaging) or when imaging is not advisable (such as during pregnancy and breastfeeding). Ongoing clinical studies using NAF samples will likely shed light on NAF’s content and clinical potential. Here, we present a narrative review and perspectives of NAF research at a glance.

Aluminium in cosmetics and personal care products

Usage of inorganic ingredients like aluminium salts in cosmetics and personal care products has been a concern for producers and consumers. Although aluminium is used to treat hyperhidrosis, some worries have been raised about aluminium's role in breast cancer, breast cyst and Alzheimer's disease. The human population is exposed to aluminium from vaccines, diet, and drinking water, but the frequent use of aluminium-based cosmetics might add additional local exposure. This paper reviews literature to determine if aluminium-based products may pose potential harm to the body. The dermal absorption of aluminium is not widely understood. It is not yet known whether aluminium can travel from the skin to brain to cause Alzheimer's disease. Aluminium may cause gene instability, alter gene expression or enhance oxidative stress, but the carcinogenicity of aluminium has not been proved yet. Until now, epidemiological researches were based on oral information, which lacks consistency, and the results are conflicting. Future studies should target real-life-based long-time exposure to antiperspirants and other aluminium-containing cosmetics and personal care products.

Aluminum Content of Human Milk and Antiperspirant Use

Background: Aluminum exposure may originate from numerous sources, including antiperspirants. Aluminum toxicity can cause a wide range of neurological impairments. Infants are exposed to aluminum through human milk (HM), formulas, total-parenteral-nutrition and vaccines. Due to potential risk of toxicity to both infants and women, it has been advised that lactating women decrease their use of aluminum-based products and antiperspirants. Our study aimed to determine whether the use of aluminum-based antiperspirants (ABA) affects aluminum levels in HM. Methods: This cross-sectional study included healthy mothers who exclusively breastfed infants (1 week to 5 months). Questionnaires were used to collect data on demographics, antiperspirant use and aluminum exposure. Mothers were instructed to express HM during the morning at first breastfeeding session. Aluminum levels were measured by atomic absorption spectrometry with a 5 ppb limit of detection. Results: Fifteen of the 58 (26%) recruited mothers used an aluminum-free antiperspirant (AFA) and 43 (74%) used an ABA. The range of aluminum concentration in HM was 0-100.8 μg/L (mean 11.4 ± 17.4 μg/L). The median aluminum level (Q1-Q3) was 6.5 μg/L (5.2-11.9) and 5.2 μg/L (3.46-9.4) in the AFA and ABA groups, respectively (p = 0.19). The aluminum levels were not affected by maternal age, education, diet, number of children, infant age, lactation stage or self-reported aluminum exposure. Conclusion: The data from this preliminary study demonstrate that the use of an ABA by lactating mothers does not increase their HM aluminum content. Additional studies with a larger cohort are warranted to confirm these findings.

Diet as a Potential Moderator for Genome Stability and Immune Response in Pediatric Leukemia

Simple Summary

Pediatric acute lymphoblastic leukemia (ALL) is the most prevalent cancer affecting children in developed societies. Here, we review the role of diet in control of the incidence and progression of childhood ALL. Prenatally, ALL risk is associated with higher birthweights of newborns, suggesting that ALL begins to evolve in-utero. Indeed, maternal diet influences the fetal genome and immune development. Postnatally, breastfeeding associates with decreased risk of ALL development. Finally, for the ALL-affected child, certain dietary regimens that impact the hormonal environment may impede disease progression. Improved understanding of the dietary regulation of hormones and immunity may inform better approaches to predict, protect, and ultimately save children afflicted with pediatric leukemia.

Abstract

Pediatric leukemias are the most prevalent cancers affecting children in developed societies, with childhood acute lymphoblastic leukemia (ALL) being the most common subtype. As diet is a likely modulator of many diseases, this review focuses on the potential for diet to influence the incidence and progression of childhood ALL. In particular, the potential effect of diets on genome stability and immunity during the prenatal and postnatal stages of early childhood development are discussed. Maternal diet plays an integral role in shaping the bodily composition of the newborn, and thus may influence fetal genome stability and immune system development. Indeed, higher birth weights of newborns are associated with increased risk of ALL, which suggests in-utero biology may shape the evolution of preleukemic clones. Postnatally, the ingestion of maternal breastmilk both nourishes the infant, and provides essential components that strengthen and educate the developing immune system. Consistently, breast-feeding associates with decreased risk of ALL development. For children already suffering from ALL, certain dietary regimens have been proposed. These regimens, which have been validated in both animals and humans, alter the internal hormonal environment. Thus, hormonal regulation by diet may shape childhood metabolism and immunity in a manner that is detrimental to the evolution or expansion of preleukemic and leukemic ALL clones.

Critical Adjuvant Influences on Preventive Anti-Metastasis Vaccine Using a Structural Epitope Derived from Membrane Type Protease PRSS14

We tested how adjuvants effect in a cancer vaccine model using an epitope derived from an autoactivation loop of membrane-type protease serine protease 14 (PRSS14; loop metavaccine) in mouse mammary tumor virus (MMTV)-polyoma middle tumor-antigen (PyMT) system and in 2 other orthotopic mouse systems. Earlier, we reported that loop metavaccine effectively prevented progression and metastasis regardless of adjuvant types and T_H types of hosts in tail-vein injection systems. However, the loop metavaccine with Freund's complete adjuvant (CFA) reduced cancer progression and metastasis while that with alum, to our surprise, were adversely affected in 3 tumor bearing mouse models. The amounts of loop peptide specific antibodies inversely correlated with tumor burden and metastasis, meanwhile both T_H1 and T_H2 isotypes were present regardless of host type and adjuvant. Tumor infiltrating myeloid cells such as eosinophil, monocyte, and neutrophil were asymmetrically distributed among 2 adjuvant groups with loop metavaccine. Systemic expression profiling using the lymph nodes of the differentially immunized MMTV-PyMT mouse revealed that adjuvant types, as well as loop metavaccine can change the immune signatures. Specifically, loop metavaccine itself induces T_H2 and T_H17 responses but reduces T_H1 and T_reg responses regardless of adjuvant type, whereas CFA but not alum increased follicular T_H response. Among the myeloid signatures, eosinophil was most distinct between CFA and alum. Survival analysis of breast cancer patients showed that eosinophil chemokines can be useful prognostic factors in PRSS14 positive patients. Based on these observations, we concluded that multiple immune parameters are to be considered when applying a vaccine strategy to cancer patients.

Neurotoxic effects of combined exposures to aluminum and mercury in early life (infancy)

Aluminum and mercury are environmentally ubiquitous. Individually they are both neurotoxic elements with shared neuro-pathogenic pathways: oxidative stress, altered neurotransmission, and disruption of the neuroendocrine and immune systems. In the infant, Al and Hg differ in type of exposure, absorption, distribution (brain access), and metabolism. In environmentally associated exposure (breast milk and infant formulas) their co-occurrences fluctuate randomly, but in Thimerosal-containing vaccines (TCVs) they occur combined in a proprietary ratio; in these cases, low-doses of Thimerosal-ethylmercury (EtHg) and adjuvant-Al present the most widespread binary mixture in less developed countries. Although experimental studies at low doses of the binary Hg and Al mixture are rare, when studied individually they have been shown to affect neurological outcomes negatively. In invitro systems, comparative neurotoxicity between Al and Hg varies in relation to the measured parameters but seems less for Al than for Hg. While neurotoxicity of environmental Hg (mainly fish methyl-Hg, MeHg) is associated with neurobehavioral outcomes in children, environmental Al is not associated, except in certain clinical conditions. Therefore, the issues of their neurotoxic effects (singly or combined) are discussed. In the infant (up to six months) the organic-Hg and Al body burdens from a full TCV schedule are estimated to reach levels higher than that originating from breastfeeding or from high aluminum soy-based formulas. Despite worldwide exposure to both Al and Hg (inorganic Hg, MeHg, and Thimerosal/EtHg), our knowledge on this combined exposure is insufficient to predict their combined neurotoxic effects (and with other co-occurring neurotoxicants).

Aluminum in Coffee

This study investigated the aluminum content in one of the most consumed daily beverages: coffee. The total Al concentration in 10 different samples of coffee beans and their water-extractable fraction were determined. We then tested the influence of different brewing methods on the concentration of the extracted Al in the final beverage. Metal analyses were performed using graphite furnace atomic absorption spectroscopy (GF-AAS) after microwave-assisted acid digestion. The results showed highly variable Al contents in coffee beans (1.5-15.5 mg kg^-1), of which ∼2-10% were water-extractable. The brewing technique had a major influence on the Al content in the beverage: significantly higher Al concentrations (72.57 ± 23.96 μg L^-1) occurred in coffee brewed in an aluminum moka pot. Interestingly, using ground coffee with this method even reduced the Al content in the final beverage compared to the brewing water used. Coffee brewed from Al capsules did not contain significantly higher Al concentrations compared to other methods.

Neuroprotective effect of quercetin nanoparticles: A possible prophylactic and therapeutic role in alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is the most common cause of dementia in elderly. Quercetin is a well-known flavonoid with low bioavailability. Recently, quercetin nanoparticles (QNPs) has been shown to have a better bioavailability.

AIMS

This study aimed to investigate the protective and therapeutic effects of QNPs in Aluminum chloride (AlCl₃) induced animal model of AD.

MATERIALS AND METHODS

AD was induced in rats by oral administration of AlCl₃ (100 mg/kg/day) for 42 days. QNPs (30 mg/kg) was given along with AlCl₃ in the prophylactic group and following AD induction in the treated group. Hippocampi were harvested for assessments of the structural and ultrastructural changes using histological and histochemical approaches.

RESULTS AND DISCUSSION

AD hippocampi showed a prominent structural and ultrastructural disorders both neuronal and extraneuronal. Including neuronal degeneration, formation of APs and NFTs, downregulation of tyrosine hydroxylase (TH), astrogliosis and inhibition of the proliferative activity (all P ≤ 0.05). Electron microscopy showed signs of neuronal degeneration with microglia and astrocyte activation and disruption of myelination and Blood Brain Barrier (BBB). Interestingly, QNPs administration remarkably reduced the neuronal degenerative changes, APs and NFTs formation (all P ≤ 0.05). Furthermore, it showed signs of regeneration (all P ≤ 0.05) and upregulation of TH. The effect was profound in the prophylactic group. Thus, QNPs reduced the damaging effect of AlCl₃ on hippocampal neurons at the molecular, cellular and subcellular levels.

CONCLUSION

For the best of our knowledge this is the first study to show a prophylactic and therapeutic effect for QNPs in AD model. This might open the gate for further research and provide a new line for therapeutic intervention in AD.

Competition between Al3+ and Fe3+ binding to human transferrin and toxicological implications: structural investigations using ultra-high resolution ESI MS and CD spectroscopy

Human serum transferrin (hTF) is an iron binding protein with the primary task of ensuring well-controlled transport of Fe3+-ions in the bloodstream. Furthermore, hTF has been identified as a key component in the trafficking of Al3+-ions from the serum to cells. It is clear that binding alone does not guarantee cellular uptake via the transferrin receptor, since this is determined by the structural properties of the metal-protein complex. The conformation of the metallated hTF is critically important for delivery of Fe3+ or any other metal into the cell. The combination of ultra-high resolution ESI mass spectrometry and CD spectroscopy together provide accurate species distribution of the Fe3+ during stepwise addition to apo-hTF and an indirect indication of the tertiary structure of the metallated protein. These two methods together are extremely fine probes of structural changes as a function of precise metal binding status at micromolar concentrations. Simulation of the precise domain distribution could be determined during the stepwise metallation from 0 to 2 Fe3+ added. Analysis of the ESI-MS data for the stepwise metallation of apo-hTF and Al1 or 2-hTF with Fe3+ was carried out and used to simulate the experimental speciation based on the reported KF values. There are six main conclusions: (1) Fe3+ binds predominantly, initially to the C-lobe. (2) The CD spectral properties indicate that the C-lobe metallation dominates the structural properties of both binding sites; N-lobe metallation modifies the C-lobe structure. (3) Fe3+ metallation of the mixed Al1-2-hTF results in the dominant form of Fe1Al1-hTF. (4) The first Fe3+ bound to Al1-hTF binds predominantly in the C-lobe domain. (5) The CD spectral properties when Fe3+ binds to Al1-2-hTF indicates that Al-N-lobe occupation mirrors the structural effects of N-lobe occupation by Fe3+. (6) With respect to how Al3+ might enter the cell, the formation of a hybrid form Al1Fe1-hTF might enable the Al3+ to enter the cell via receptor-mediated endocytosis due to the binding of Fe3+ in the C-lobe of the protein which is primarily responsible for the structure of the metal-protein complex.

Chemical Speciation of Aluminum in Wine by LC-ICP-MS

Aluminum is very common in the natural environment and in everyday human life. We are living in the "aluminum age." Its average daily intake should not exceed a few mg/day. Unfortunately, despite the growing number of alarming data about the toxicity of this element, human exposure to aluminum is constantly increasing. The toxicity and bioavailability of aluminum depends mainly on the form in which it occurs. The main variables conditioning the form are the concentration, the type, the molar ratio of aluminum to ligand, the pH value, and the temperature. This research presents a new method for speciation analysis of both inorganic and organic aluminum complexes in model solutions by LC-ICP-MS. Different solutions with variable pH values and different Al/ligand molar ratios (fluorides and several organic ligands, e.g., citrates and oxalates ions) were used. The chromatographic separation process was carried out based on isocratic and gradient elution, using a cation exchange analytical column. All determinations have been confirmed based on chemical equilibrium modeling programs. The new developed method was successfully applied for the first time in speciation analysis of real samples: white and red wine.

The contribution of orthodontic braces to aluminum exposure in humans: an experimental in vitro study

There is limited information on whether metals such as aluminum (Al) can migrate from orthodontic braces to saliva and subsequently contribute to its exposure in humans. This study aimed to assess this experimentally by incubating elastomeric orthodontic ligatures in artificial saliva for 30 days and other components of orthodontic braces (brackets, arch wires, and retainers) up to 180 days. As demonstrated, significantly higher levels of Al were leached from elastomeric ligatures (mean ± SD 28.2 ± 6.8 μg compared with their stainless steel counterparts (3.6 ± 0.1 μg) during 30 days. The higher the incubation time, the greater levels of Al leaching to artificial saliva were observed with the highest levels found for CNA β arch wire (252 ± 12 μg), Ni-Ti-Al arch wire (224 ± 11 μg), ceramic brackets (199 ± 10 μg), stainless steel arch wire (108 ± 5 μg), and metallic brackets (81.0 ± 4.2 μg) after 180 days of incubation. However, considering the tolerable weekly intake (TWI) established by the European Food Safety Authority, the intraoral use of orthodontic braces considered in this study would in the worst case constitute 0.04% and 0.09% of TWI in 70-kg adults and 30-kg children, respectively. In conclusion, the orthodontic braces considered in this study have no contribution to Al exposure in humans and can be considered safe in this regard.

Aluminium toxicosis: a review of toxic actions and effects

Aluminium (Al) is frequently accessible to animal and human populations to the extent that intoxications may occur. Intake of Al is by inhalation of aerosols or particles, ingestion of food, water and medicaments, skin contact, vaccination, dialysis and infusions. Toxic actions of Al induce oxidative stress, immunologic alterations, genotoxicity, pro-inflammatory effect, peptide denaturation or transformation, enzymatic dysfunction, metabolic derangement, amyloidogenesis, membrane perturbation, iron dyshomeostasis, apoptosis, necrosis and dysplasia. The pathological conditions associated with Al toxicosis are desquamative interstitial pneumonia, pulmonary alveolar proteinosis, granulomas, granulomatosis and fibrosis, toxic myocarditis, thrombosis and ischemic stroke, granulomatous enteritis, Crohn's disease, inflammatory bowel diseases, anemia, Alzheimer's disease, dementia, sclerosis, autism, macrophagic myofasciitis, osteomalacia, oligospermia and infertility, hepatorenal disease, breast cancer and cyst, pancreatitis, pancreatic necrosis and diabetes mellitus. The review provides a broad overview of Al toxicosis as a background for sustained investigations of the toxicology of Al compounds of public health importance.

A Schiff-base receptor based chromone derivate: Highly selective fluorescent and colorimetric probe for Al(III)

Upon excitation of the visible light, probes show colorimetric and fluorescent responses to the specific metal ion, which can be easily detected by the naked eye. Owing to the excitation of the visible light at 423 nm, a novel and simple Schiff-base receptor based chromone derivative called 7-methoxychromone-3-carbaldehyde-(indole-3-formyl) hydrazone (MCIH2) had been investigated as a selective and sensitive probe for Al³⁺ with colorimetric and fluorescent responses. Upon addition of Al³⁺ to compound MCIH2 solution, compound MCIH2 could respond to Al³⁺ with a good selective colorimetric signal, which was easily observed from colorless to yellow-green by the naked eye. Furthermore, a remarkable fluorescence emission enhancement with an "OFF-ON" signal by over 700-fold was triggered, but other various metal ions had no such significant effects on the fluorescence emission. In addition, the detection limit of compound MCIH2 for recognizing Al³⁺ was evaluated to be as low as 1 × 10^-7 M level, which was sufficiently low for sensing Al³⁺ widely distributed in various environmental and biological systems.

Paraben Toxicology

Parabens now being formally declared as the American Contact Dermatitis Society (non)allergen of the year, the allergologic concerns regarding parabens raised during the past century are no longer a significant issue. The more recent toxicological concerns regarding parabens are more imposing, stemming from the gravity of the noncutaneous adverse health effects for which they have been scrutinized for the past 20 years. These include endocrine activity, carcinogenesis, infertility, spermatogenesis, adipogenesis, perinatal exposure impact, and nonallergologic cutaneous, psychologic, and ecologic effects. To assert that parabens are safe for use as currently used in the cosmetics, food, and pharmaceutical industries, all toxicological end points must be addressed. We seek to achieve perspective through this exercise: perspective for the professional assessing systemic risk of parabens by all routes of exposure. The data reviewed in this article strive to provide a balanced perspective for the consumer hopefully to allay concerns regarding the safety of parabens and facilitate an informed decision-making process. Based on currently available scientific information, claims that parabens are involved in the genesis or propagation of these controversial and important health problems are premature. Haste to remove parabens from consumer products could result in their substitution with alternative, less proven, and potentially unsafe alternatives, especially given the compelling data supporting the lack of significant dermal toxicity of this important group of preservatives.

Aggregation-Induced Emission-Active Hydrazide-Based Probe: Selective Sensing of Al3+, HF2 -, and Nitro Explosives

(E)-N'-((2-Hydroxynaphthalen-1-yl)methylene)picolinohydrazide (H-PNAP) shows aggregation-induced emission (AIE) strictly in a 90% water/MeOH (v/v) mixture at 540 nm, and the solid-state emission is blue-shifted to 509 nm upon excitation at 400 nm. The AIE activity of H-PNAP is selectively quenched by 2,4,6-trinitrophenol (TNP) and 2,4-dinitrophenol (DNP) out of different nitroaromatic compounds with a limit of detection (LOD) of 7.79 × 10-7 and 9.08 × 10-7 M, respectively. The probe is nonemissive in aqueous medium (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, HEPES buffer, pH 7.2); however, it shows a strong emission to Al3+ (λem, 490 nm) in the presence of 17 other biological metal ions, and the LOD is 2.09 nM which is far below the WHO recommended value (7.41 mM). The emission of the [Al(PNAP)(NO3)2] complex is quenched by HF2 - (F- and PO4 3- are weak quencher), and the LOD is as low as 15 nM. The probable mechanism of the sensing feature of the probe has been authenticated by 1H nuclear magnetic resonance titration, mass spectrometry, Fourier transform infrared spectroscopy, Benesi-Hildebrand plot, and Job's plot in each case. The probe has some practical applications such as recovery of Al3+ from the drinking water sample, construction of the INHIBIT logic gate, and detection kits for Al3+ and TNP/DNP by simple paper test strips. The probe, H-PNAP, has successfully been applied to the detection of intracellular Al3+ and HF2 - ions in the human breast cancer cell, MDA-MB-468.

Increased Aluminum Content in Certain Brain Structures is Correlated with Higher Silicon Concentration in Alcoholic Use Disorder

INTRODUCTION

Alcohol overuse may be related to increased aluminum (Al) exposure, the brain accumulation of which contributes to dementia. However, some reports indicate that silicon (Si) may have a protective role over Al-induced toxicity. Still, no study has ever explored the brain content of Al and Si in alcoholic use disorder (AUD).

MATERIALS AND METHODS

To fill this gap, the present study employed inductively coupled plasma optical emission spectrometry to investigate levels of Al and Si in 10 brain regions and in the liver of AUD patients (n = 31) and control (n = 32) post-mortem.

RESULTS

Al content was detected only in AUD patients at mean ± SD total brain content of 1.59 ± 1.19 mg/kg, with the highest levels in the thalamus (4.05 ± 12.7 mg/kg, FTH), inferior longitudinal fasciculus (3.48 ± 9.67 mg/kg, ILF), insula (2.41 ± 4.10 mg/kg) and superior longitudinal fasciculus (1.08 ± 2.30 mg/kg). Si content displayed no difference between AUD and control, except for FTH. Positive inter-region correlations between the content of both elements were identified in the cingulate cortex, hippocampus, and ILF.

CONCLUSIONS

The findings of this study suggest that AUD patients may potentially be prone to Al-induced neurodegeneration in their brain-although this hypothesis requires further exploration.

The etiology, diagnosis, and management of hyperhidrosis: A comprehensive review: Therapeutic options

Hyperhidrosis (HH) is a chronic disorder of excess sweat production that may have a significant adverse effect on quality of life. A variety of treatment modalities currently exist to manage HH. Initial treatment includes lifestyle and behavioral recommendations. Antiperspirants are regarded as the first-line therapy for primary focal HH and can provide significant benefit. Iontophoresis is the primary remedy for palmar and plantar HH. Botulinum toxin injections are administered at the dermal-subcutaneous junction and serve as a safe and effective treatment option for focal HH. Oral systemic agents are reserved for treatment-resistant cases or for generalized HH. Energy-delivering devices such as lasers, ultrasound technology, microwave thermolysis, and fractional microneedle radiofrequency may also be utilized to reduce focal sweating. Surgery may be considered when more conservative treatments have failed. Local surgical techniques, particularly for axillary HH, include excision, curettage, liposuction, or a combination of these techniques. Sympathectomy is the treatment of last resort when conservative treatments are unsuccessful or intolerable, and after accepting secondary compensatory HH as a potential complication. A review of treatment modalities for HH and a sequenced approach are presented.

Analysis of aluminum, minerals and trace elements in the milk samples from lactating mothers in Hamadan, Iran

The present cross-sectional study is aimed at analyzing the breast milk of lactating mothers in Hamadan, Iran for aluminum and several minerals and trace elements. Ten governmental health care centers were utilized to facilitate collection of breast milk samples. The breast milk samples were collected at 1, 2, 6, 7, and 12 months postpartum from one hundred healthy lactating women, who delivered full-term newborns. Detection of sodium (Na), zinc (Zn), calcium (Ca), iron (Fe), copper (Cu), magnesium (Mg) and aluminum (Al) levels was conducted with the use of Inductively Coupled Plasma Mass Spectrometry (ICP-MS). This method has shown high accuracy, precision, sensitivity, and linearity for the wide range of concentrations. The accumulated data were not normally distributed; thus, the non-parametric Mann-Whitney U test was used in the statistical analysis of the results. Mean concentrations of Fe, Zn, Cu, Ca, Mg, and Na were 0.75, 1.38, 0.35, 255, 34.58, and 155.72 μg/mL, respectively. The mean level of Al, a well-known neurotoxic metal, was determined to be an alarming 0.191 μg/mL. Moreover, 95% of participants contained very harmful concentrations of Al in their milk. This study also revealed Zn deficiency in about 50% of milk samples. Further investigation is needed to elucidate sources of exposure and factors that may influence maternal and fetal exposure to aluminum.

Assessment of hair metal levels in aluminium plant workers using scalp hair ICP-DRC-MS analysis

The objective of the present study was to assess the level of aluminium and toxic metals in hair of workers occupationally exposed to aluminium. 124 employees of the aluminium plant working in the hydrometallurgical (n = 43) and sintering units (n = 41), as well as 40 occupationally nonexposed controls were examined. Hair aluminium (Al), arsenic (As), beryllium (Be), cadmium (Cd), mercury (Hg), nickel (Ni), lead (Pb), and tin (Sn) content was assessed using inductively-coupled plasma mass spectrometry. The obtained data demonstrate that aluminium plant workers had significantly higher levels of hair Al (28.8 (15.4-58.6) vs 7.8 (4.3-14.2) μg/g, p < 0.001), Cd (0.053 (0.032 - 0.095) vs 0.025 (0.014 - 0.043) μg/g, p < 0.001) and Pb (0.672 (0.299-1.310) vs 0.322 (0.170 - 0.609) μg/g, p = 0.012) than the controls, respectively. Further analysis demonstrated that persons involved in different technological processes were characterized by distinct hair metal profiles. Hair Al, Be, Cd, Ni, Pb, and Sn levels in men working in the sintering unit of the aluminium plant exceeded the respective control values. In turn, workers of the hydrometallurgical unit were characterized by more than 2-fold higher levels of Al and Cd in hair as compared to the controls. The results of the present study demonstrate that workers of the aluminium plant are characterized by increased risk of Al as well as As, Cd, Pb, and Sn exposure.

A paper platform for colorimetric determination of aluminum hydrochloride in antiperspirant samples

A simple, fast, low-cost, portable, and eco-friendly method using a spot test on a paper platform, together with diffuse reflectance spectroscopy, was developed and validated for the quantification of aluminum hydrochloride, a potential neurotoxic agent, in antiperspirant samples. The determination of aluminum hydrochloride was performed at a wavelength of 615 nm, by measuring consumption of the purple colorimetric reagent Alizarin S, due to reaction with aluminum. The linear range was from 10.0 to 125.0 mg L^-1 and could be described by the equation: A_R = 0.4479 - 0.002543 C_Al (R = 0.999). The limits of detection (LOD) and quantification (LOQ) were 3.06 and 10.2 mg L^-1, respectively. The method was specific, accurate, and repeatable, with relative standard deviation (RSD) <5.0%. The recovery was between 92.2 and 103.4%. The method was successfully used for the determination of aluminum hydrochloride in commercial antiperspirant samples, revealing concentrations below the maximum permitted by current legislation.

A novel chromone and rhodamine derivative as fluorescent probe for the detection of Zn(II) and Al(III) based on two different mechanisms

In this study, a novel fluorescent probe, 6‑hydroxychromone‑3‑carbaldehyde‑(rhodamine B carbonyl) hydrazine (L), for Zn²⁺ and Al³⁺ was designed and synthesized. Initially, this probe L exhibited inferior fluorescence emission peak centered at 488 nm in EtOH/HEPES solution (3/1, 10.0 μM HEPES, pH 7.4) when excited at 421 nm. After the addition of Zn²⁺, this probe L displayed excellent selectivity towards Zn²⁺ with obvious fluorescence color change from colorless to yellow, which might be attributed to the formation of a 1:1 ligand-metal complex resulting in the inhibition of photo-induced electron transfer phenomenon. Whereas, the prepared Zn²⁺ complex of L could be used as a ratiometric fluorescent probe to detect Al³⁺ on the basis of fluorescence resonance energy transfer mechanism. This ligand-metal complex of Zn²⁺ (LZn) showed high selectivity towards Al³⁺ with obvious enhancement in fluorescence emission intensity at 580 nm and remarkable decrease in fluorescence emission intensity at 488 nm, and the fluorescence color also changed from yellow to pink. Furthermore, the detection limit of the probe L, LZn towards Zn²⁺, Al³⁺ were 1.25 × 10^-7 M and 3.179 × 10^-6 M, respectively. Additionally, the complexation properties of L towards Zn²⁺ and LZn towards Al³⁺ were studied in detail.

Recent advances on the stimulatory effects of metals in breast cancer

Certain environmental chemicals may accumulate in human serum and tissues eliciting estrogenic and/or carcinogenic effects. Therefore, there is heightened interest in determining whether environmental chemicals may increase the risk for endocrine-related tumors like breast cancer. For instance, metals as cadmium, zinc, copper, iron, nickel and aluminum have been shown to mimic estrogen action. Moreover, the exposure to these chemicals has been reported to stimulate diverse malignancies including breast cancer, which is the most common tumor in women worldwide. In this review, we summarize the epidemiologic and experimental evidence regarding the association between the exposure to some trace elements and breast cancer risk. We also address recent insights on the molecular mechanisms involved by metals in breast tumorigenesis.

The putative role of environmental aluminium in the development of chronic neuropathology in adults and children. How strong is the evidence and what could be the mechanisms involved?

The conceptualisation of autistic spectrum disorder and Alzheimer's disease has undergone something of a paradigm shift in recent years and rather than being viewed as single illnesses with a unitary pathogenesis and pathophysiology they are increasingly considered to be heterogeneous syndromes with a complex multifactorial aetiopathogenesis, involving a highly complex and diverse combination of genetic, epigenetic and environmental factors. One such environmental factor implicated as a potential cause in both syndromes is aluminium, as an element or as part of a salt, received, for example, in oral form or as an adjuvant. Such administration has the potential to induce pathology via several routes such as provoking dysfunction and/or activation of glial cells which play an indispensable role in the regulation of central nervous system homeostasis and neurodevelopment. Other routes include the generation of oxidative stress, depletion of reduced glutathione, direct and indirect reductions in mitochondrial performance and integrity, and increasing the production of proinflammatory cytokines in both the brain and peripherally. The mechanisms whereby environmental aluminium could contribute to the development of the highly specific pattern of neuropathology seen in Alzheimer's disease are described. Also detailed are several mechanisms whereby significant quantities of aluminium introduced via immunisation could produce chronic neuropathology in genetically susceptible children. Accordingly, it is recommended that the use of aluminium salts in immunisations should be discontinued and that adults should take steps to minimise their exposure to environmental aluminium.

Genotoxic effects in transformed and non-transformed human breast cell lines after exposure to silver nanoparticles in combination with aluminium chloride, butylparaben or di-n-butylphthalate

In the present study genotoxic effects after combined exposure of human breast cell lines (MCF-10A, MCF-7 and MDB-MB-231) to silver nanoparticles (AgNP, citrate stabilized, 15 and 45nm by STEM, Ag15 and Ag45, respectively) with aluminium chloride, butylparaben, or di-n-butylphthalate were studied. In MCF-10A cells exposed for 24h to Ag15 at the concentration of 23.5μg/mL a statistically significant increase in DNA damage in comet assay (SSB) was observed. In the presence of the test chemicals the genotoxic effect was decreased to a level comparable to control values. In MCF-7 cells a significant increase in SSB level was observed after exposure to Ag15 at 16.3μg/mL. The effect was also diminished in the presence of the three test chemicals. In MDA-MB-231 cells no significant increase in SSB was observed, however increased level of oxidative DNA damage (incubation with Fpg enzyme) was observed after exposure to combinations of both AgNP with aluminium chloride. No increase in micronuclei formation was observed in neither cell line after the single nor combined treatments. Our results point to a low risk of increased genotoxic effects of AgNP when used in combination with aluminium salts, butylparaben or di-n-butylphthalate in consumer products.

Use of Underarm Cosmetic Products in Relation to Risk of Breast Cancer: A Case-Control Study

Background

Previous studies on breast cancer (BC), underarm cosmetic products (UCP) and aluminum salts have shown conflicting results. We conducted a 1:1 age-matched case-control study to investigate the risk for BC in relation to self-reported UCP application.

Methods

Self-reported history of UCP use was compared between 209 female BC patients (cases) and 209 healthy controls. Aluminum concentration in breast tissue was measured in 100 cases and 52 controls. Multivariable conditional logistic regression analysis was performed to estimate odds ratios (ORs) with 95% confidence intervals (CIs), adjusting for established BC risk factors.

Findings

Use of UCP was significantly associated with risk of BC (p = 0.036). The risk for BC increased by an OR of 3.88 (95% CI 1.03–14.66) in women who reported using UCP's several times daily starting at an age earlier than 30 years. Aluminum in breast tissue was found in both cases and controls and was significantly associated to self-reported UCP use (p = 0.009). Median (interquartile) aluminum concentrations were significantly higher (p = 0.001) in cases than in controls (5.8, 2.3–12.9 versus 3.8, 2.5–5.8 nmol/g).

Interpretation

Frequent use of UCPs may lead to an accumulation of aluminum in breast tissue. More than daily use of UCPs at younger ages may increase the risk of BC.

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Frequent use of underarm cosmetic products may be related to incorporated aluminum concentration in breast tissue.

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Use of underarm cosmetic products several times a day at younger ages may increase the risk of breast cancer.

Previous studies regarding breast cancer (BC) risk and underarm cosmetic products (UCPs) with aluminum salts have shown conflicting results. Here we provide comprehensive information about the use of UCPs and aluminum measurements in breast cancer patients and healthy individuals. The findings suggest that the frequent use of UCPs lead to an accumulation of aluminum in breast tissue. We observed an increased risk for BC in women who reported to use UCPs more than once daily starting at an age < 30 years. We recommend that particularly women at younger ages should be careful using UCPs and avoid its excessive use.

Binding of Al(iii) to synthetic RNA and metal-mediated strand aggregation

Kinetic curve of the binding of aluminum to RNA and metal-induced strand aggregation.

Exposure to cyclic volatile methylsiloxanes (cVMS) causes anchorage-independent growth and reduction of BRCA1 in non-transformed human breast epithelial cells

Dermal absorption of components of personal care products (PCPs) may contribute to breast cancer development. Cyclic volatile methylsiloxanes (cVMS) are used widely in the formulation of PCPs, and their presence has been recently detected in human blood. The objectives of this study were to investigate any genotoxic effects after short- (1 week) or longer-term (30 weeks) exposure to hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4) or decamethylcyclopentasiloxane (D5) in MCF-10 A and MCF-10F immortalized non-transformed human breast epithelial cells. Genotoxic effects were assessed by an ability of cells to grow in suspension culture, from DNA damage measured by comet assays, and from a reduction in levels of DNA repair proteins measured by RT-PCR and western immunoblotting. Dose-dependent anchorage-independent growth in methocel culture was observed after exposure to D3 (10^-13  M-10^-5  M) and D4/D5 (10^-9  M-10^-5  M). DNA damage was measured by the comet assay after 1-h exposure to D3 (10^-6  M-10^-5  M) and D4 (10^-5  M). BRCA1 mRNA and BRCA1 protein levels were reduced after 30-week exposure to 10^-5  M D4 and D5 in both cell lines. Reduced levels of mRNAs for other DNA repair proteins (BRCA2, ATM, ATR, CHK1 and CHK2) were also observed after exposure to 10^-5  M D5 in both cell lines, and some reductions after exposure to D3 and D4. If cVMS can not only enable anchorage-independent growth of non-transformed breast epithelial cells and damage DNA, but also compromise DNA repair systems, then there is the potential for them to impact on breast carcinogenesis. Further risk assessment now requires information concerning the extent to which cVMS may be present in human breast tissues. Copyright © 2016 John Wiley & Sons, Ltd.

Heavy Metal Bioaccumulation in an Atypical Primitive Neuroectodermal Tumor of the Abdominal Wall

Heavy metals are able to interfere with the function of vital cellular components. Besides in trace heavy metals, which are essential at low concentration for humans, there are heavy metals with a well-known toxic and oncogenic potential. In this study, for the first time in literature, we report the unique adulthood case of an atypical primitive neuroectodermal tumor of the abdominal wall, diagnosed by histology and immunohistochemistry, with the molecular hybridization support. The neoplasia occurred in a patient chronically exposed to a transdermal delivery of heavy metal salts (aluminum and bismuth), whose intracellular bioaccumulation has been revealed by elemental microanalysis.

The toxicity of aluminium in humans

We are living in the 'aluminium age'. Human exposure to aluminium is inevitable and, perhaps, inestimable. Aluminium's free metal cation, Alaq(3+), is highly biologically reactive and biologically available aluminium is non-essential and essentially toxic. Biologically reactive aluminium is present throughout the human body and while, rarely, it can be acutely toxic, much less is understood about chronic aluminium intoxication. Herein the question is asked as to how to diagnose aluminium toxicity in an individual. While there are as yet, no unequivocal answers to this problem, there are procedures to follow to ascertain the nature of human exposure to aluminium. It is also important to recognise critical factors in exposure regimes and specifically that not all forms of aluminium are toxicologically equivalent and not all routes of exposure are equivalent in their delivery of aluminium to target sites. To ascertain if Alzheimer's disease is a symptom of chronic aluminium intoxication over decades or breast cancer is aggravated by the topical application of an aluminium salt or if autism could result from an immune cascade initiated by an aluminium adjuvant requires that each of these is considered independently and in the light of the most up to date scientific evidence. The aluminium age has taught us that there are no inevitabilities where chronic aluminium toxicity is concerned though there are clear possibilities and these require proving or discounting but not simply ignored.