tellurium and Abnormalities--Drug-Induced

CdTe quantum dots (QDs) are nanocrystals of unique composition and properties that have found many new commercial applications; therefore, their potential toxicity to aquatic organisms has become a hot research topic. The lab study was performed to determine the developmental and behavioral toxicities to zebrafish under continuous exposure to low concentrations of CdTe QDs (1-400 nM) coated with thioglycolic acid (TGA). The results show: (1) the 120 h LC(50) of 185.9 nM, (2) the lower hatch rate and body length, more malformations, and less heart beat and swimming speed of the exposed zebrafish, (3) the brief burst and a higher basal swimming rate of the exposed zebrafish larvae during a rapid transition from light-to-dark, and (4) the vascular hyperplasia, vascular bifurcation, vascular crossing and turbulence of the exposed FLI-1 transgenic zebrafish larvae.

Topics: Abnormalities, Drug-Induced; Animals; Blood Vessels; Cadmium Compounds; Embryo, Nonmammalian; Female; Growth; Heart Rate; Larva; Male; Photoperiod; Quantum Dots; Reproduction; Swimming; Tellurium; Zebrafish

BACKGROUND AND OBJECTIVE. Nanotechnology works with substances at a nanometer scale, and it offers many solutions for biomedicine. Nanoparticles (NPs) have been shown as effective agents for imaging, drug delivery, pathogen detection, etc. However, to date, NP toxicity is poorly known. The aim of our study was to investigate the embryotoxicity and teratogenicity of quantum dots (QDs) at the different stages of rat embryogenesis. MATERIALS AND METHODS. Wistar rats were injected with CdSe/ZnS or CdTe QDs on the 6th, 13th, and 18th days of embryogenesis. Cyclophosphamide was chosen as a positive control of embryotoxicity. On the 21st day, the number of resorptions, weight, length, and external malformations of the embryos were estimated. Fluorescence spectroscopy and microscopy analysis were used to determine the accumulation of QDs in the tissues. RESULTS. Exposure to cyclophosphamide during the pregnancy decreased the embryonic weight and length when compared with the control group and produced numerous malformations. The effects depended on the stage of embryogenesis. Meanwhile, QDs did not cause any embryotoxic or teratogenic effects. However, CdTe QDs induced necrosis in the tissues of the peritoneal cavity. The necrotic tissues contained QDs with altered spectroscopic properties. Spectroscopic and microscopic tissue examination revealed that QDs accumulated in the placenta, but no penetration to the embryonic tissues was observed. CONCLUSIONS. QDs did not cause any direct embryotoxic or teratogenic effects, but they had adverse effects on the maternal organism. The observed QD effects and the long-term accumulation of QDs in the maternal organism may increase the risk of adverse effects on embryo development.

Topics: Abnormalities, Drug-Induced; Animals; Cadmium Compounds; Cyclophosphamide; Embryo, Mammalian; Embryonic Development; Female; Nanoparticles; Pregnancy; Quantum Dots; Rats; Selenium Compounds; Sulfides; Tellurium; Zinc Compounds

Tellurium dioxide (TeO2) induces hydrocephalus, edema, exophthalmia, ocular hemorrhage, umbilical hernia, undescended testes and small kidneys in day 20 Wistar rat fetuses when administered s.c. to pregnant dams from gestational day 15 to 19. At doses of 500 mumole/kg or greater, a 100% incidence of these findings and a reduction in maternal weight gain were observed. A pair-fed study at the dose of 500 mumole/kg of TeO2 was conducted to establish if the effects of tellurium were a result of a reduction in food intake or other maternal toxic responses. Two additional control groups of rats receiving tellurium or vehicle were fed ad libitum. After a comparable maternal weight gain from day 0 to 15, weight gain was significantly reduced in the treated groups and the pair-fed control. There was a reduction of fetal weight in the treated groups (p less than 0.01) and in the pair-fed control (p less than 0.02). There was a 100% incidence of the above anomalies in the litters of the two treated groups, but none in the pair-fed and control groups. No histological alterations other than a mild centrolobular fatty change in the liver were detected in the other organs from the tellurium exposed dams. Thus, tellurium induces both maternal toxicity and teratogenic effects in the rat where the teratogenicity is not mediated by alterations in the diet.

Topics: Abnormalities, Drug-Induced; Animals; Eating; Female; Pregnancy; Rats; Rats, Inbred Strains; Tellurium; Weight Gain

The effects of multiple maternal subcutaneous injections of tellurium dioxide (TeO2) suspended in olive oil (0-1,000 mumol/kg) from day 15 to day 19 of gestation were evaluated in the Wistar rat. External and internal soft-tissue examinations were performed on day 20 fetuses. Multiple maternal injections, at doses higher than 10 mumol/kg, resulted in a dose-related appearance of hydrocephalus, edema, exophthalmia, ocular hemorrhage, umbilical hernia, undescended testis, and small kidneys in fetuses on day 20 of gestation. At 500 mumol/kg, reduction in maternal weight gain was also observed. At this level, the incidence of the above anomalies was 100%. The 100 mumol/kg dose of Te, which did not produce apparent maternal toxic responses, resulted in a 100% incidence of hydrocephalus and edema but no fetal mortality. Thus, tellurium can be teratogenic to the rat fetus without concomitant maternal toxicity. Also, the fetal period may be more sensitive than the organogenic period for the induction of hydrocephalus. Such evidence is consistent with the development of the choroid plexus and an effect of TeO2 on the production/resorption of cerebrospinal fluid.

Topics: Abnormalities, Drug-Induced; Animals; Embryonic and Fetal Development; Eye Abnormalities; Female; Hydrocephalus; Kidney; Male; Maternal-Fetal Exchange; Pregnancy; Rats; Rats, Inbred Strains; Tellurium; Testis

The developmental toxicity of tellurium was evaluated in Crl Sprague-Dawley rats and New Zealand white rabbits by means of standard segment II-type studies. Groups of pregnant rats were fed a diet containing 0, 30, 300, 3000, or 15,000 ppm of tellurium on Days 6 through 15 of gestation (microscopic detection of sperm in a smear of vaginal contents considered as Day 0), and artificially inseminated rabbits were fed a diet containing 0, 17.5, 175, 1750, and 5250 ppm of tellurium during Days 6 through 18 of gestation (day of insemination considered as Day 0). Signs of maternal toxicity were observed during the treatment period in a statistically significant and dose-related manner at dietary concentrations of 300 ppm and greater in rats and 1750 ppm and greater in rabbits. Exposure of these pregnant rats and rabbits to tellurium had no effect upon reproduction as measured by pregnancy rate, litter size, dead or resorbed implantations, or fetal sex ratio. Both skeletal (primarily skeletal maturational delays) and soft tissue malformations (primarily hydrocephalus) were noted in the offspring of pregnant rats exposed to the highest levels (3000 and 15,000 ppm) of tellurium. Rabbit fetuses of the highest dosage group (5250 ppm) had a slightly elevated evidence of skeletal delays and nonspecific abnormalities. Since maternal toxicity was observed at dosages that did not affect the developing conceptus, there were no indications of unique developmental susceptibility upon exposure of pregnant rats or rabbits to tellurium.

Topics: Abnormalities, Drug-Induced; Animals; Bone and Bones; Connective Tissue; Female; Hydrocephalus; Pregnancy; Prenatal Exposure Delayed Effects; Rabbits; Rats; Rats, Inbred Strains; Tellurium

Topics: Abnormalities, Drug-Induced; Animals; Brain Chemistry; Diet; Female; Gestational Age; Hydrocephalus; Microscopy, Electron; Pregnancy; Rats; Rats, Inbred Strains; Tellurium; Time Factors

Topics: Abnormalities, Drug-Induced; Animals; Autoradiography; Blood-Brain Barrier; Choroid Plexus; Female; Fetus; Gestational Age; Hydrocephalus; Maternal-Fetal Exchange; Pregnancy; Radioisotopes; Rats; Tellurium

Topics: Abnormalities, Drug-Induced; Animals; Embryo, Mammalian; Female; Fetal Diseases; Gestational Age; Hydrocephalus; Injections, Intramuscular; Injections, Intraperitoneal; Pregnancy; Rats; Tellurium

Topics: Abnormalities, Drug-Induced; Administration, Oral; Animals; Female; Fetal Diseases; Gestational Age; Hydrocephalus; Maternal-Fetal Exchange; Pregnancy; Rats; Tellurium; Time Factors

Topics: Abnormalities, Drug-Induced; Animals; Brain; Cerebral Ventricles; Ependyma; Female; Fetus; Hydrocephalus; Maternal-Fetal Exchange; Microscopy, Electron; Pregnancy; Rats; Tellurium

Topics: Abnormalities, Drug-Induced; Abortion, Veterinary; Animals; Antimony; Arsenic Poisoning; Bismuth; Copper; Female; Lead Poisoning; Pregnancy; Pregnancy Complications; Pregnancy, Animal; Sheep; Tellurium; Zinc

Topics: Abnormalities, Drug-Induced; Animals; Birds; Chick Embryo; Congenital Abnormalities; Pharmacology; Radiation Effects; Radioisotopes; Research; Selenium; Selenium Compounds; Sulfur; Sulfur Isotopes; Tellurium; Toxicology

Topics: Abnormalities, Drug-Induced; Animals; Animals, Newborn; Female; Humans; Hydrocephalus; Infant, Newborn; Maternal-Fetal Exchange; Pregnancy; Rats; Research; Tellurium; Toxicology