245 research outputs found
Lead levels in fur of rats treated with inorganic lead measured by inductively coupled argon plasma mass spectrometry
The aim of this study was to investigate the relationship between continuous lead exposure and the concentration of this metal in fur. The two main questions we wanted to answer were: 1) Are the fur lead concentrations different according to exposure level? 2) Is the kinetics of lead concentration linear in different compartments
Mineral analysis of complete dog and cat foods in the UK and compliance with European guidelines
Mineral content of complete pet food is regulated to ensure health of the companion animal population. Analysis of adherence to these regulatory guidelines has not been conducted. Here, mineral composition of complete wet (n = 97) and dry (n = 80) canine and feline pet food sold in the UK was measured to assess compliance with EU guidelines. A majority of foods complied with ≥8 of 11 guidelines (99% and 83% for dry and wet food, respectively), but many failed to provide nutritional minimum (e.g. Cu, 20% of wet food) or exceeded nutritional maximum (e.g. Se, 76% of wet food). Only 6% (6/97) of wet and 38% (30/80) of dry food were fully compliant. Some foods (20–30% of all analysed) had mineral imbalance, such as not having the recommended ratio of Ca:P (between 1:1 to 2:1). Foods with high fish content had high levels of undesirable metal elements such as arsenic. This study highlights broad non-compliance of a range of popular pet foods sold in the UK with EU guidelines (94% and 61% of wet and dry foods, respectively). If fed exclusively and over an extended period, a number of these pet foods could impact the general health of companion animals
Toxic metals in toenails as biomarkers of exposure: A review
This work was supported by FIS grants PI12/00150, PI17CIII/00034, PI18/00287 (Instituto de Salud Carlos III, State Secretary of R + D + I and European Union (ERDF/ESF, "Investing in your future") ) , P42ES010349 and P30ES009089 (National Institute of Environmental Health Sciences) .Toenails have been used as biomarkers of exposure to toxic metals, but their validity for this purpose is not yet
clear and might differ depending on the specific agent. To evaluate this issue, we reviewed the literature on: a)
the time-window of exposure reflected by toenails; b) the reproducibility of toenail toxic-metal levels in repeated
measures over time; c) their relationship with other biomarkers of exposure, and; d) their association with potential
determinants (i.e. sociodemographic, anthropometric, or lifestyle characteristics) or with sources of
exposure like diet or environmental pollution.
Thus, we performed a systematic review, searching for articles that provided original data for levels of any of
the following toxic metals in toenails: aluminum, beryllium, cadmium, chromium, mercury, nickel, lead, thallium
and uranium.
We identified 88 articles, reporting data from 67 different research projects, which were quite heterogeneous
with regard to population profile, sample size and analytical technique. The most commonly studied metal was
mercury. Concerning the time-window of exposure explored by toenails, some reports indicate that toenail
cadmium, nickel and lead may reflect exposures that occurred 7–12 months before sampling. For repeated
samples obtained 1–6 years apart, the range of intraindividual correlation coefficients of aluminum, chromium
and mercury was 0.33–0.56. The correlation of toxic metal concentrations between toenails and other matrices
was higher for hair and fingernails than for urine or blood. Mercury levels were consistently associated with fish
intake, while other toxic metals were occasionally associated with specific sources (e.g. drinking water, place of
residence, environmental pollution, and occupation). The most frequently evaluated health endpoints were
cardiovascular diseases, cancer, and central nervous system diseases.
Available data suggest that toenail mercury levels reflected long-term exposures and showed positive associations
with fish intake. The lack of standardization in sample collection, quality control, analytical techniques
and procedures – along with the heterogeneity and conflicting results among studies – mean it is still difficult to conclude that toenails are a good biomarker of exposure to toxic metals. Further studies are needed to draw solid
conclusions about the suitability of toenails as biomarkers of exposure to toxic metals.FIS (Instituto de Salud Carlos III, State Secretary of R + D + I) PI12/00150
PI17CIII/00034
PI18/00287FIS (European Union (ERDF/ESF, "Investing in your future") PI12/00150
PI17CIII/00034
PI18/00287
United States Department of Health & Human Services
National Institutes of Health (NIH) - USA
NIH National Institute of Environmental Health Sciences (NIEHS) P42ES010349
P30ES00908
Elevated creatine kinase activity in primary hepatocellular carcinoma
BACKGROUND: Inconsistent findings have been reported on the occurrence and relevance of creatine kinase (CK) isoenzymes in mammalian liver cells. Part of this confusion might be due to induction of CK expression during metabolic and energetic stress. METHODS: The specific activities and isoenzyme patterns of CK and adenylate kinase (AdK) were analysed in pathological liver tissue of patients undergoing orthotopic liver transplantation. RESULTS: The brain-type, cytosolic BB-CK isoenzyme was detected in all liver specimens analysed. Conversely, CK activity was strongly increased and a mitochondrial CK (Mi-CK) isoenzyme was detected only in tissue samples of two primary hepatocellular carcinomas (HCCs). CONCLUSION: The findings do not support significant expression of CK in normal liver and most liver pathologies. Instead, many of the previous misconceptions in this field can be explained by interference from AdK isoenzymes. Moreover, the data suggest a possible interplay between p53 mutations, HCC, CK expression, and the growth-inhibitory effects of cyclocreatine in HCC. These results, if confirmed, could provide important hints at improved therapies and cures for HCC
Toenails as biomarker of exposure to essential trace metals: A review
Health problems associated with essential trace metals can result from both inadequate (i.e., low intake) and
excessive exposures (i.e., from environmental and/or occupational source). Thus, measuring the exposure level
is a real challenge for epidemiologists. Among non-invasive biomarkers that intend to measure long-term exposure
to essential trace metals, the toenail is probably the biological matrix with the greatest potential.
This systematic review collects the current evidence regarding the validity of toenail clippings as exposure
biomarker for trace metals such as boron, cobalt, copper, iron, manganese, molybdenum, selenium, silicon,
vanadium and zinc. Special attention was paid to the time-window of exposure reflected by the toenail, the
intraindividual variability in exposure levels over time in this matrix, and the relationship of toenail with other
biomarkers, personal characteristics and environmental sources.
Our search identified 139 papers, with selenium and zinc being the most studied elements. The variability
among studies suggests that toenail levels may reflect different degrees of exposure and probably correspond to
exposures occurred 3–12 months before sampling (i.e., for manganese/selenium). Few studies assessed the reproducibility
of results over time and, for samples obtained 1–6 years apart, the correlation coefficient were
between 0.26 and 0.66. Trace metal levels in toenails did not correlate well with those in the blood and urine and
showed low-moderate correlation with those in the hair and fingernails.This work was supported by FIS grants PI12/00150, PI17CIII/00034
& PI18/00287 (Instituto de Salud Carlos III, State Secretary of
R + D + I and European Union (ERDF/ESF, "Investing in your future"))
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