Associations of maternal urinary rare earth elements individually and in mixtures with neonatal size at birth.

Prenatal rare earth elements (REEs) exposure is linked to unfavorable health consequences. Epidemiologic research on repeated measurements of REEs during gestation correlated with fetal growth is exiguous. Until now, few studies have characterized exposure characteristics of REEs in pregnant women. We aimed to ascertain the characteristics and predictors of REEs exposure over three trimesters among pregnant women and examine the possible effects of prenatal REEs exposure on size at birth. Urinary REEs concentrations exhibited considerable within-subject variation with intraclass correlation coefficients ranging from 0.16 to 0.58. Maternal age, household income, gestational weight gain, passive smoking during pregnancy, parity, and neonatal gender were associated with maternal urinary REEs concentrations. Elevated maternal urinary holmium and thulium concentrations in the 3rd trimester were significantly related to reductions in birth weight. Weighted quantile sum (WQS) regression model identified that urinary REEs mixture in the 3rd trimester were negatively related to birth weight (WQSREEs ß = -26.22; 95% confidence interval [CI]: -47.62, -4.82), with holmium (40%) and thulium (24%) receiving the highest weights. Male infants received the most weight (>50%) related to decreased birth weight. This study revealed a significant association between individual and mixture REE exposure in late pregnancy with a reduction in birth weight.

A CORM loaded nanoplatform for single NIR light-activated bioimaging, gas therapy, and photothermal therapy in vitro.

Carbon monoxide (CO) can cause mitochondrial dysfunction, inducing apoptosis of cancer cells, which sheds light on a potential alternative for cancer treatment. However, the existing CO-based compounds are inherently limited by their chemical nature, such as high biological toxicity and uncontrolled CO release. Therefore, a nanoplatform - UmPF - that addresses such pain points is urgently in demand. In this study, we have proposed a nanoplatform irradiated by near-infrared (NIR) light to release CO. Iron pentacarbonyl (Fe(CO)5) was loaded in the mesoporous polydopamine layer that was coated on rare-earth upconverting nanoparticles (UCNPs). The absorption wavelength of Fe(CO)5 overlaps with the emission bands of the UCNPs in the UV-visible light range, and therefore the emissions from the UCNPs can be used to incite Fe(CO)5 to control the release of CO. Besides, the catechol groups, which are abundant in the polydopamine structure, serve as an ideal locating spot to chelate with Fe(CO)5; in the meantime, the mesoporous structure of the polydopamine layer improves the loading efficiency of Fe(CO)5 and reduces its biological toxicity. The photothermal effect (PTT) of the polydopamine layer is highly controllable by adjusting the external laser intensity, irradiation time and the thickness of the polydopamine layer. The results illustrate that the combination of CO gas therapy (GT) and polydopamine PTT brought by the final nanoplatform can be synergistic in killing cancer cells in vitro. More importantly, the possible toxic side effects can be effectively prevented from affecting the organism, since CO will not be released in this system without near-infrared light radiation.

The ROS-generating photosensitizer-free NaYF4:Yb,Tm@SiO2upconverting nanoparticles for photodynamic therapy application.

In this work we adapt rare-earth-ion-doped NaYF4nanoparticles coated with a silicon oxide shell (NaYF4:20%Yb,0.2%Tm@SiO2) for biological and medical applications (for example, imaging of cancer cells and therapy at the nano level). The wide upconversion emission range under 980 nm excitation allows one to use the nanoparticles for cancer cell (4T1) photodynamic therapy (PDT) without a photosensitizer. The reactive oxygen species (ROS) are generated by Tm/Yb ion upconversion emission (blue and UV light). Thein vitroPDT was tested on 4T1 cells incubated with NaYF4:20%Yb,0.2%Tm@SiO2nanoparticles and irradiated with NIR light. After 24 h, cell viability decreased to below 10%, demonstrating very good treatment efficiency. High modification susceptibility of the SiO2shell allows for attachment of biological molecules (specific antibodies). In this work we attached the anti-human IgG antibody to silane-PEG-NHS-modified NaYF4:20%Yb,0.2%Tm@SiO2nanoparticles and a specifically marked membrane model by bio-conjugation. Thus, it was possible to perform a selective search (a high-quality optical method with a very low-level organic background) and eventually damage the targeted cancer cells. The study focuses on therapeutic properties of NaYF4:20%Yb,0.2%Tm@SiO2nanoparticles and demonstrates, upon biological functionalization, their potential for targeted therapy.

Thulium oxide nanoparticles as radioenhancers for the treatment of metastatic cutaneous squamous cell carcinoma.

Metastases from cutaneous squamous cell carcinoma (cSCC) occur in 2%-5% of cases. Surgery is the standard treatment, often combined with adjuvant radiotherapy. Concurrent carboplatin treatment with post-operative radiotherapy may be prescribed, although it has not shown benefit in recent clinical trials in high-risk cSCC patients. The novel high-Z nanoparticle thulium (III) oxide has been shown to enhance radiation dose delivery to brain tumors by specific uptake of these nanoparticles into the cancerous tissue. As the dose-enhancement capacity of thulium oxide nanoparticles following radiotherapy against metastatic cSCC cells is unknown, its efficacy as a radiosensitizer was evaluated, with and without carboplatin. Novel and validated human patient-derived cell lines of metastatic cSCC were used. The sensitivity of the cells to radiation was investigated using short-term proliferation assays as well as clonogenic survival as the radiobiological endpoint. Briefly, cells were irradiated with 125 kVp orthovoltage x-rays (0-6 Gy) with and without thulium oxide nanoparticles (99.9% trace metals basis; 50 µg ml-1) or low dose carboplatin pre-sensitization. Cellular uptake of the nanoparticles was first confirmed by microscopy and found to have no impact on short-term cell survival for the cSCC cells, highlighting the biocompatibility of thulium oxide nanoparticles. Clonogenic cell survival assays confirmed radio-sensitization when exposed to thulium nanoparticles, with the cell sensitivity increasing by a factor of 1.24 (calculated at the 10% survival fraction) for the irradiated cSCC cells. The combination of carboplatin with thulium oxide nanoparticles with irradiation did not result in significant further reductions in survival compared to nanoparticles alone. This is the first study to provide in vitro data demonstrating the independent radiosensitization effect of high-Z nanoparticles against metastatic cSCC with or without carboplatin. Further preclinical investigations with radiotherapy plus high-Z nanoparticles for the management of metastatic cSCC are warranted.

Green synthesis of highly dispersed ytterbium and thulium co-doped sodium yttrium fluoride microphosphors for in situ light upconversion from near-infrared to blue in animals.

We report a simple, low cost and environmentally friendly method to prepare NaYF4:Yb3+, Tm3+ upconversion microphosphors (UCMPs) by thermal decomposition of rare earth-trifluoroacetate precursors using paraffin as the high boiling non-coordinating solvent. The UCMPs exhibited cubic phase with defined shape and bright upconversion luminescence. After coating with amphiphilic polymers of phospholipid-polyethylene glycol, the NaYF4:Yb3+, Tm3+ UCMPs were highly dispersed in aqueous solutions and exhibited low cytotoxicity. Furthermore, we explored the use of the micro-injected micro-sized NaYF4:Yb3+, Tm3+ particles for converting of near infrared into blue light in mice brain. The in vivo macroscopic upconversion luminescence imaging results showed that UCMPs located at 1mm depth in the brain could be clearly distinguished. Microscopic upconversion luminescence imaging of the brain sections in vitro revealed that the UCMPs embedded at the particular location in brain tissues of mice were stable without significant diffusion in two weeks.

Androgen Deprivation Accelerates the Prostatic Urethra Wound Healing After Thulium Laser Resection of the Prostate by Promoting Re-Epithelialization and Regulating the Macrophage Polarization.

BACKGROUND: Complications after a thulium laser resection of the prostate (TmLRP) are related to re-epithelialization of the prostatic urethra. Since prostate growth and development are induced by androgen, the aim of this study was to determine the role and explore the mechanism of androgen in wound healing of the prostatic urethra. METHODS: Beagles that received TmLRPs were randomly distributed into a castration group, a testosterone undecanoate (TU) group, and a control group. The prostate wound was assessed once a week using a cystoscope. Histological analysis was then carried out to study the re-epithelialization of the prostatic urethra in each group. The inflammatory response in the wound tissue and urine was also investigated. RESULTS: The healing of the prostatic urethra after a TmLRP was more rapid in the castration group and slower in the TU group than that in the control group. Castration accelerated re-epithelialization by promoting basal cell proliferation in the wound surface and beneath the wound and by accelerating the differentiation of basal cells into urothelial cells. Castration reduced the duration of the inflammatory phase and induced the conversion of M1 macrophages to M2 macrophages, thus accelerating the maturation of the wound. By contrast, androgen supplementation enhanced the inflammatory response and prolonged the inflammatory phase. Moreover, the anti-inflammatory phase was delayed and weakened. CONCLUSION: Androgen deprivation promotes re-epithelialization of the wound, regulates the inflammatory response, and accelerates wound healing of the prostatic urethra after a TmLRP. Prostate 77:708-717, 2017. © 2017 Wiley Periodicals, Inc.

Thulium ion promotes apoptosis of primary mouse bone marrow stromal cells.

Bone is one of the main target organs for the lanthanides (Ln). Biodistribution studies of Tm-based compounds in vivo showed that bone had significant uptake. But the effect of Tm(3+) on primary mouse bone marrow stromal cells (BMSCs) has not been reported. So we investigated the effect and underlying mechanisms of Tm(3+) on BMSCs. Cell viability, cell apoptosis, reactive oxygen species (ROS) level, lactate dehydrogenase (LDH) activity and mitochondrial membrane potential (MMP) were studied. The results indicated that Tm(3+) increased the viability of BMSCs at concentrations of 1×10(−7), 1×10(−6), 1×10(−5), and 1×10(−4) mol/L in a dose-dependent manner, turned to decrease the viability of BMSCs at the highest concentration of 1×10(−3) mol/L for 24, 48, and 72 h. Tm(3+) at 1×10(−3) mol/L promoted apoptosis of BMSCs, increased the ROS and LDH levels, and decreased MMP in BMSCs. Taken together, we demonstrated that Tm(3+) + at 1×10(−3) mol/L might induce cellular apoptosis through mitochondrial pathway. These resultsmay be helpful for more rational application of Tm-based compounds in the future.

Scalp topography of ultralate (C-fibres) evoked potentials following thulium YAG laser stimuli to tiny skin surface areas in humans.

AIM: To investigate (1) the scalp topography of ultralate laser evoked potentials (LEPs) related to C-fibre activation, which can directly be obtained by thulium YAG (Tm YAG) laser stimulation of tiny skin surface areas (about 0.23 mm(2)) and (2) the influence of the performance of a motor task on ultralate LEPs. METHODS: Laser stimuli were applied to the dorsum of the left hand. LEPs were recorded with 58 scalp electrodes from 9 healthy subjects in two different conditions, with and without a reaction time (RT) task (press a button upon detection). RESULTS: On high resolution electroenchephalogram recordings, ultralate LEPs were characterized by a broad positive component (peak latency: 1133+/-91 ms) with maximum amplitude about the vertex. Moreover, the performance of a RT task had no influence on latency, amplitude and topographical patterns of two maps chosen at the positive peak latency in ultralate LEPs. Nevertheless, a negative inflexion (latency 1300 ms) appeared after the positive component in the task condition possibly reflecting movement-related potentials. CONCLUSION: Tm YAG laser stimulation of tiny skin surface areas allows recording the dynamic scalp topography of ultralate (C-fibres) LEPs, with or without the performance of a RT task.

The influence of isotopic and nonisotopic carriers on the biodistribution and biokinetics of M3+-citrate complexes.

The influence of carrier amounts of Fe, Ga, and Tm on the biodistribution of 67Ga-, 59Fe-, and 167Tm-citrate in mice was investigated. Our results suggest that 167Tm, unlike 67Ga and 59Fe, is not transported by transferrin in the blood. Of the three radioisotopes tested, 167Tm had the highest tumor/background ratio (10 h after the injection). The application of Fe carrier led to an enhancement of the elimination of 67Ga from the blood and muscles, resulting in a better tumor/background ratio.

Calcium and pancreatic beta-cell function. IX. Demonstration of lanthanide-induced inhibition of insulin secretion independent of modifications in transmembrane Ca2+ fluxes.

beta-Cell-rich pancreatic islets were microdissected from noninbred ob/ob-mice and used to examine the mode of action of trivalent lanthanide ions on insulin secretion. La3+, Sm3+, and Tm3+ were equally effective inhibitors of basal and glucose-stimulated insulin release. As indicated by perifusion experiments with Tm3+, the inhibitory action was prompt, sustained, and readily reversible. Despite the similarities among the lanthanides in inhibiting insulin secretion, these cations differed considerably in their ability to impair transmembrane 45Ca fluxes. Using 10 different members of the lanthanide series, it was possible to demonstrate that their effectiveness to inhibit 45Ca uptake increased with ionic radius. La3+ markedly inhibited intracellular uptake and superficial binding of 45Ca at both 3 and 20 mM glucose. However, Tm3+ failed to affect intracellular 45Ca uptake and only reduced superficial binding of 45Ca at 3 mM glucose. In efflux experiments, Tm3+ did not affect basal or glucose-stimulated 45Ca washout from islets perifused with a medium containing 1.28 mM Ca2+. In a Ca2+-deficient medium, Tm3+ caused a slight transient increase, followed by reduction of 45Ca washout. However, when glucose was omitted, there was a prompt increase in the washout of radioactivity in the presence of Tm3+. Accordingly, the potent inhibitory action of Tm3+ on insulin secretion is not matched by changes in transmembrane Ca2+ fluxes. Since the lanthanides do not penetrate intracellularly, we propose the existence of cationic binding sites in the beta-cell plasma membrane with direct inhibitory effects on insulin secretion.

Conformation of gramicidin A channel in phospholipid vesicles: a 13C and 19F nuclear magnetic resonance study.

We have determined the conformation of the channel-forming polypeptide antibiotic gramicidin A in phosphatidylcholine vesicles by using 13C and 19F NMR spectroscopy. The models previously proposed for the conformation of the dimer channel differ in the surface localization of the NH2 and COOH termini. We have incorporated specific 13C and 19F nuclei at both the NH2, and COOH termini of gramicidin and have used 13C and 19F chemical shifts and spin lattice relaxation time measurements to determine the accessibility of these labels to three paramagnetic NMR probes--two in aqueous solution and one attached to the phosphatidylcholine fatty acid chain9 all of our results indicate that the COOH terminus of gramicidin in the channel is located near the surface of the membrane and the NH2 terminus is buried deep within the lipid bilayer. These findings strongly favor an NH2-terminal to NH2-terminal helical dimer as the major conformation for the gramicidin channel in phosphatidylcholine vesicles.

An analysis of the action of cations of the lanthanide series on the mechanical responses of guinea-pig ileal longitudinal muscle.

1. The inhibitory effects of lanthanide cations (Ln3+) on mechanical responses and 45Ca uptake in guinea-pig ileal longitudinal smooth muscle were studied. 2. Ln3+ strongly inhibited the phasic and tonic component of the response to the muscarinic agonist cis-2-methyl-4-dimethylaminomethyl-1,3-dioxolane methiodide (CD) the two components being affected to the same extent. Inhibition was also obtained for the responses evoked by high K+ but here the effect was mainly on the phasic response, the tonic component was merely delayed. 3. Other members of the Ln3+ series, with the exception of cerium, were found to be more effective than lanthanum in their ability to inhibit the CD response. Thulium, Tm3+, the thirteenth member of the series was the most effective cation. 4. Analysis of 170Tm uptake revealed at least two components. The concentration-dependence of one component, saturating at 2-5 x 10(-6) Tm, corresponded closely to that of the inhibitory effect of Tm3+ on contraction. 5. 170Tm uptake as a function of time showed a secondary rise after 30 min of exposure to the lanthanide. 6. Although 2-5 x 10(-6) M-Tm3+ produced 90% inhibition of the CD and the high K+ induced responses significant reduction of 45Ca uptake by the muscle was only detected when much higher Tm3+ concentrations (greater than or equal 10(-3) M-Tm3+) were used. 7. It is concluded that Ln3+ combine with membrane sites specifically involved in Ca2+ translocation during excitation-contraction coupling.

The effects of lanthanum and thulium on the mechanical responses of rat vas deferens.

1. The contractile responses of rat vas deferens to noradrenaline and K+ are composed of phasic and tonic components both of which are dependent upon the concentration of extracellular Ca2+. 2. Lanthanum, La3+, and thulium ions, Tm3+, inhibited the noradrenaline and K+ induced responses, complete inhibition being obtained at approximately 10(-3) M-Ln3+. 3. La3+ and Tm3+ were equally effective in inhibiting noradrenaline and K+ responses. The phasic and tonic components of the noradrenaline response were equally sensitive to lanthanide cations, Ln3+, but the phasic component of the K+ response was more sensitive than the tonic component. 4. 170Tm binding did not show any saturable component over the concentration range in which inhibition of the pharmacological response was obtained. 5. It is suggested that the actions of Ln3+ in the rat vas deferens are mediated through some kind of membrane stabilization rather than via a specific Ca2+ binding site concerned with excitation-contraction coupling, the mechanism previously postulated for the Ln3+ action in guinea-pig ileal longitudinal muscle.