The Uptake and Distribution Evidence of Nano- and Microplastics in vivo after a Single High Dose of Oral Exposure.

Objective: Tissue uptake and distribution of nano-/microplastics was studied at a single high dose by gavage in vivo. Methods: Fluorescent microspheres (100 nm, 3 µm, and 10 µm) were given once at a dose of 200 mg/(kg∙body weight). The fluorescence intensity (FI) in observed organs was measured using the IVIS Spectrum at 0.5, 1, 2, and 4 h after administration. Histopathology was performed to corroborate these findings. Results: In the 100 nm group, the FI of the stomach and small intestine were highest at 0.5 h, and the FI of the large intestine, excrement, lung, kidney, liver, and skeletal muscles were highest at 4 h compared with the control group ( P < 0.05). In the 3 µm group, the FI only increased in the lung at 2 h ( P < 0.05). In the 10 µm group, the FI increased in the large intestine and excrement at 2 h, and in the kidney at 4 h ( P < 0.05). The presence of nano-/microplastics in tissues was further verified by histopathology. The peak time of nanoplastic absorption in blood was confirmed. Conclusion: Nanoplastics translocated rapidly to observed organs/tissues through blood circulation; however, only small amounts of MPs could penetrate the organs.

Evidence on Invasion of Blood, Adipose Tissues, Nervous System and Reproductive System of Mice After a Single Oral Exposure: Nanoplastics versus Microplastics.

Objective: This study was designed to provide the evidences on the toxicokinetics of microplastics (MPs) and nanoplastics (NPs) in the bodies of mammals. Methods: 100 nm, 3 µm, and 10 µm fluorescent polystyrene (PS) beads were administered to mice once by gavage at a dose of 200 mg/kg body weight. The levels and change of fluorescence intensity in samples of blood, subcutaneous fat, perirenal fat, peritesticular fat, cerebrum, cerebellum, testis, and epididymis were measured at 0.5, 1, 2, and 4 h after administration using an IVIS Spectrum small-animal imaging system. Histological examination, confocal laser scanning, and transmission electron microscope were performed to corroborate the findings. Results: After confirming fluorescent dye leaching and impact of pH value, increased levels of fluorescence intensity in blood, all adipose tissues examined, cerebrum, cerebellum, and testis were measured in the 100 nm group, but not in the 3 and 10 µm groups except in the cerebellum and testis at 4 h for the 3 µm PS beads. The presence of PS beads was further corroborated. Conclusion: After a single oral exposure, NPs are absorbed rapidly in the blood, accumulate in adipose tissues, and penetrate the blood-brain/testis barriers. As expected, the toxicokinetics of MPs is significantly size-dependent in mammals.

Combined effects of obesity and di-(2-ethylhexyl) phthalate on testosterone levels and kisspeptin/GPR54 expression in hypothalamus and testes of male mice.

BACKGROUND: This study evaluated whether obese male mice exposed to di-(2-ethylhexyl) phthalate (DEHP) showed synergistic effects on testosterone levels and the potential underlying mechanism. METHODS: Forty-eight male mice were assigned to six groups for 12-week treatments as follows: normal, DEHP100, diet-induced obesity (DIO), DIO + DEHP30, DIO + DEHP100, and DIO + DEHP300. Serum hormone levels, including testosterone (T), luteinizing hormone (LH), and leptin, were detected by ELISA. The levels of Ob-R, kisspeptin, and GPR54 protein expression in hypothalamus and testicular tissues were measured by western blot. RESULTS: There were significantly lower levels of serum T and LH, higher levels of serum leptin and Ob-R, and kisspeptin and GPR54 protein expression were reduced in hypothalamus and testicular tissues in the DIO and DEHP groups compared with controls. Moreover, serum T and leptin levels were more severe in the combined DIO and DEHP exposure group than in the single exposure groups. Serum LH levels and GPR54 expression in the testis were significantly decreased in DIO + DEHP300 mice compared with DIO mice (p < 0.05). CONCLUSION: Obesity- and DEHP-only exposure had adverse effects on testosterone levels in mice, which may be due to high leptin levels and decreased Ob-R, kisspeptin, and GPR54 expression. Obesity combined with DEHP exposure had an additive adverse effect on testosterone levels in mice. One of the potential mechanisms is higher leptin levels and decreased GPR54 expression in the testes.

Effect of meteorological factors on influenza-like illness from 2012 to 2015 in Huludao, a northeastern city in China.

BACKGROUND: This study aims to describe the epidemiological patterns of influenza-like illness (ILI) in Huludao, China and seek scientific evidence on the link of ILI activity with weather factors. METHODS: Surveillance data of ILI cases between January 2012 and December 2015 was collected in Huludao Central Hospital, meteorological data was obtained from the China Meteorological Data Service Center. Generalized additive model (GAM) was used to seek the relationship between the number of ILI cases and the meteorological factors. Multiple Smoothing parameter estimation was made on the basis of Poisson distribution, where the number of weekly ILI cases was treated as response, and the smoothness of weather was treated as covariates. Lag time was determined by the smallest Akaike information criterion (AIC). Smoothing coefficients were estimated for the prediction of the number of ILI cases. RESULTS: A total of 29, 622 ILI cases were observed during the study period, with children ILI cases constituted 86.77%. The association between ILI activity and meteorological factors varied across different lag periods. The lag time for average air temperature, maximum air temperature, minimum air temperature, vapor pressure and relative humidity were 2, 2, 1, 1 and 0 weeks, respectively. Average air temperature, maximum air temperature, minimum air temperature, vapor pressure and relative humidity could explain 16.5%, 9.5%, 18.0%, 15.9% and 7.7% of the deviance, respectively. Among the temperature indexes, the minimum temperature played the most important role. The number of ILI cases peaked when minimum temperature was around -13 °C in winter and 18 °C in summer. The number of cases peaked when the relative humidity was equal to 43% and then began to decrease with the increase of relative humidity. When the humidity exceeded 76%, the number of ILI cases began to rise. CONCLUSIONS: The present study first analyzed the relationship between meteorological factors and ILI cases with special consideration of the length of lag period in Huludao, China. Low air temperature and low relative humidity (cold and dry weather condition) played a considerable role in the epidemic pattern of ILI cases. The trend of ILI activity could be possibly predicted by the variation of meteorological factors.

Effect of (R)-α-lipoic acid supplementation on serum lipids and antioxidative ability in patients with age-related macular degeneration.

BACKGROUND/AIMS: Supplementation with antioxidants is of special interest in preventing or delaying the development and progression of age-related macular degeneration (AMD). This investigation aimed to assess the effect of α- lipoic acid (LA) on serum lipids, serum malondialdehyde (MDA) and superoxide dismutase (SOD) in patients with AMD. METHODS: A total of 62 patients (50-75 years old) with early and intermediate dry form of AMD were randomly assigned to two groups, i.e. LA administration (n = 32) and placebo (n = 30). The levels of serum lipids and MDA and SOD activity were measured before and after LA and placebo intervention. RESULTS: Compared with the parameters at baseline, serum total cholesterol (CHO), triglyceride and high- and low-density lipoprotein CHO (HDL and LDL) levels were not significantly different after LA and placebo intervention. There was a slight but statistically nonsignificant decrease in serum MDA levels and a statistically significant increase in serum SOD activity after LA intervention. There were no statistically significant differences in serum MDA levels or SOD activity after placebo intervention. CONCLUSION: The apparent increase in SOD activity caused by LA supplementation indicates that LA may have a possible preventive effect in the development of AMD through an antioxidant mechanism.

Protective effect of ghrelin on left ventricular remodeling in spontaneously hypertensive rats is associated with the peroxisome proliferator-activated receptor gamma-dependent pathway.

BACKGROUND: Studies suggested that exogenous ghrelin administration could prevent early left ventricular remodeling in rats with myocardial infarction. We investigated herein whether ghrelin attenuated left ventricular remodeling induced by hypertension and whether ghrelin's effect was mediated through the peroxisome proliferator-activated receptor gamma (PPAR-gamma)-dependent pathway. METHODS: Spontaneously hypertensive rats (8-week-old males) were randomly divided into three groups with 12 rats in each: ghrelin group (received ghrelin 100 microg/kg subcutaneously (s.c.) twice daily); ghrelin + GW9662 group (received the PPAR-gamma antagonist GW9662 at 2 mg/kg s.c., and then ghrelin as above); saline controls. Normal male Wistar Kyoto rats (n = 12) served as normal controls. Four weeks later, the effects of ghrelin on cardiac remodeling were evaluated by echocardiographic, hemodynamic, and histopathological examination, and gene expression analysis (PPAR-gamma protein and mRNA expression). The serum levels of C-reactive protein (CRP) and tumor necrosis factor (TNF)-alpha were detected by enzyme linked immunosorbent assay. RESULTS: Ghrelin prevented ventricular remodeling, increased PPAR-gamma expression in the myocardium, suppressed collagen I and collagen III mRNA expression, and also decreased the serum levels of TNF-alpha, but not CRP. All abovementioned effects of ghrelin were inhibited by GW9662. CONCLUSION: Ghrelin inhibited ventricular remodeling induced by hypertension, and the preventive effects of ghrelin may be mediated by the anti-inflammatory actions of the PPAR-gamma-dependent pathway.