Multielemental analysis of human fetal tissues using inductively coupled plasma-mass spectrometry

The distribution and structural fingerprints of metals from particulate matters (PM) deposited in human lungs

This work investigated the distribution and chemical fingerprints of 24 metals in particulate matter (PM) deposited in nonoccupational human lungs. Metals in the pulmonary PM can be grouped by the mean concentration as > 5 × 10³ μg/g (Al/Fe/Ca/Mg/Zn), 1-5 × 10³ μg/g (Ti/Ba/Pb/Mn), 0.2-1 × 10³ μg/g (Cu/Cr/As/V) and < 100 μg/g (Ni/Sn/Cd/Sb). Three parameters (LF_L, LR, EF_P) were defined to predict different metal leaching behaviors. The leaching factor (LF_L) of metals was 10-60 for Pb/Sb/Cd/Co/Cu and decreased to 1-2 for Ni/Cr/Mg/Al/Fe. Metals showed a divergent extent of lung retention (LR), including high retention (LR>10, Al/Cd/Cr/Ba/Ni/Ti/Sn/V/Sb), moderate retention (2 <LR<10, Pb/Mn/Fe), minor retention (1 < LR <2, Cu/Co), and negligible retention (LR<1, Ca/Mg/Zn). V and Ti were found to be mainly from indoor PM sources and deserve a close attention in healthy individuals. C-, Al- and Ti-rich fine particles were the most common pulmonary particles imaged by spherical aberration-corrected scanning transmission electron microscopy (Cs-STEM). These data establish a foundation for classification and further risk assessment of the metal species in pulmonary PM.

Role of zinc in neonatal growth and brain growth: review and scoping review

This manuscript includes (1) a narrative review of Zinc as an essential nutrient for fetal and neonatal growth and brain growth and development and (2) a scoping review of studies assessing the effects of Zinc supplementation on survival, growth, brain growth, and neurodevelopment in neonates. Very preterm infants and small for gestational age infants are at risk for Zinc deficiency. Zinc deficiency can cause several complications including periorificial lesions, delayed wound healing, hair loss, diarrhea, immune deficiency, growth failure with stunting, and brain atrophy and dysfunction. Zinc is considered essential for oligodendrogenesis, neurogenesis, neuronal differentiation, white matter growth, and multiple biological and physiological roles in neurobiology. Data support the possibility that the critical period of Zinc delivery for brain growth in the mouse starts at 18 days of a 20-21-day pregnancy and extends during lactation and in human may start at 26 weeks of gestation and extend until at least 44 weeks of postmenstrual age. Studies are needed to better elucidate Zinc requirement in extremely low gestational age neonates to minimize morbidity, optimize growth, and brain growth, prevent periventricular leukomalacia and optimize neurodevelopment. IMPACT: Zinc is essential for growth and brain growth and development. In the USA, very preterm small for gestational age infants are at risk for Zinc deficiency. Data support the possibility that the critical period of Zinc delivery for brain growth in the mouse starts at 18 days of a 20-21-day pregnancy and extends during lactation and in human may start at 26 weeks' gestation and extend until at least 44 weeks of postmenstrual age. Several randomized trials of Zinc supplementation in neonates have shown improvement in growth when using high enough dose, for long duration in patients likely to or proven to have a Zinc deficiency. Studies are needed to better elucidate Zinc requirement in extremely low gestational age neonates to minimize morbidity, optimize growth and brain growth, prevent periventricular leukomalacia and optimize neurodevelopment.

Myocardial iron content and mitochondrial function in human heart failure: a direct tissue analysis

AIMS

Iron replacement improves clinical status in iron-deficient patients with heart failure (HF), but the pathophysiology is poorly understood. Iron is essential not only for erythropoiesis, but also for cellular bioenergetics. The impact of myocardial iron deficiency (MID) on mitochondrial function, measured directly in the failing human heart, is unknown.

METHODS AND RESULTS

Left ventricular samples were obtained from 91 consecutive HF patients undergoing transplantation and 38 HF-free organ donors (controls). Total myocardial iron content, mitochondrial respiration, citric acid cycle and respiratory chain enzyme activities, respiratory chain components (complex I-V), and protein content of reactive oxygen species (ROS)-protective enzymes were measured in tissue homogenates to quantify mitochondrial function. Myocardial iron content was lower in HF compared with controls (156 ± 41 vs. 200 ± 38 µg·g^-1 dry weight, P < 0.001), independently of anaemia. MID (the lowest iron tercile in HF) was associated with more extensive coronary disease and less beta-blocker usage compared with non-MID HF patients. Compared with controls, HF patients displayed reduced myocardial oxygen₂ respiration and reduced activity of all examined mitochondrial enzymes (all P < 0.001). MID in HF was associated with preserved activity of respiratory chain enzymes but reduced activity of aconitase and citrate synthase (by -26% and -15%, P < 0.05) and reduced expression of catalase, glutathione peroxidase, and superoxide dismutase 2.

CONCLUSION

Myocardial iron content is decreased and mitochondrial functions are impaired in advanced HF. MID in HF is associated with diminished citric acid cycle enzyme activities and decreased ROS-protecting enzymes. MID may contribute to altered myocardial substrate use and to worsening of mitochondrial dysfunction that exists in HF.

Determination of protein-bound trace elements in human cell cytosols of different organs and different pathological states

In the human body, there exists over 200 different cell types, which differ in size and structure and have specialised functions in the organism. Therefore it can be assumed that these different cells also contain different proteins necessary to carry out the respective specialised functions. This supposed different metalloprotein composition in different human organs cannot be demonstrated by determination of total element concentrations. Therefore investigations of the different protein-bound forms of the elements were achieved by speciation analysis: The biomolecules were separated by size exclusion chromatography and the elements detected on-line in the eluate by a hyphenated inductively coupled plasma mass spectrometer (ICP-MS). For the interpretation of the obtained element profiles, an identification of the signals and their assignment to different metalloproteins was necessary. This identification was carried out by means of specific protein assays, i.e. enzymatic assays or immunochemical reactions, in collected fractions of the chromatographic separations. A comparison of the element binding pattern in cytosols of different human organs was then possible. The optimised method was applied to tissue cytosols of different human organs. As expected, the element patterns varied for different organs of the same patient and for the same organ of patients with different diseases. Metalloproteins and their bound metals could consequently be considered as biological markers for physiological differences or pathological changes in human tissues.