Swimming Exercise Protocol and Care Methods for Pregnant Rats.

The developmental origins of health and disease concept highlights the impact of early environments on chronic non-communicable diseases like diabetes, cardiovascular disease, and cancer. Studies using animal models have investigated how maternal factors such as undernutrition, overnutrition, obesity, and exposure to chemicals or hypoxia affect fetal development and offspring health, leading to issues like low birth weight, high blood pressure, dyslipidemia, and insulin resistance. Given the increasing prevalence of overweight and obesity among reproductive-age women, effective interventions are critical. Maternal exercise during pregnancy has emerged as a key intervention, benefiting both mother and offspring and reducing the risk of disease. This study compares the differences of three exercise models on pregnant rats: voluntary wheel running, motorized treadmills, and swimming. Swimming is the most beneficial option due to its safe and controlled intensity levels. This protocol details the rat breeding methods, swimming training during pregnancy, and post-breeding nursing protocols. This model, suitable for various rat and mouse species, is useful for studying the benefits of maternal exercise on offspring health and intergenerational wellness.

Toxic effects of pristine and aged polystyrene and their leachate on marine microalgae Skeletonema costatum.

The acute toxic effects of pristine and aged polystyrene (P-PS and A-PS) and their leaching solutions (L-PS) on microalgae Skeletonema costatum were investigated by measuring algal density and growth inhibition rate (IR), chlorophyll concentration and photosynthetic efficiency (Fv/Fm) over 96 h. Total protein (TP), superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) were measured to analyze the oxidative damage to microalgae by microplastics and their leachates. Hydrodynamic diameter of microplastics in seawater, FITR and SEM images were used to study the changes of polystyrene during aging. The interaction of algae cell with microplastics and the cellular ultrastructure changes of cells were analyzed combined with electron microscopy for a comprehensive and systematic understanding on the mechanisms of microplastic toxicity to microalgae. Both high concentration and small size of PS had significant inhibitory effect on the growth of microalgae, and the inhibitory effect was greater with increasing exposure time. The inhibition effect of aged microplastics was more obvious, which was speculated to be caused by the synergistic effect of aged PS itself and leaching solution. The negative effect of leaching solution on microalgae was due to the release of some additives during the aging process. The content of MDA reached the highest value of 54.41 nmol/mgprot in 1.0 µm 50 mg/L A-PS treatment group, and A-PS were found to be more prone to heterogeneous aggregation with algae cells by SEM.

Is hydrodynamic diameter the decisive factor? - Comparison of the toxic mechanism of nSiO2 and mPS on marine microalgae Heterosigma akashiwo.

To investigate the toxic mechanism of SiO2 nanoparticles (nSiO2) and polystyrene microplastics (mPS) on microalgae Heterosigma akashiwo, growth inhibition tests were carried out. The growth and biological responses of the algae exposed to nSiO2 (0.5, 1, 1.5, 2, 5, 10 and 30 mg L-1) and mPS (1, 2, 5, 10, 30 and 75 mg L-1) were explored in f/2 media for 96 h. It was found that the hydrodynamic diameter of the particles seems to be one of the more important factors to influence the algae. nSiO2 and mPS with similar hydrodynamic diameters have the similar toxic mechanism on H. akashiwo, and the effects were dose- and time-dependent. High concentrations of micro-/nano-particles (MNPs) could inhibit the growth of algal cells, however, low concentrations of MNPs did not restrict or even promoted the growth of algae, known as "Hormesis" phenomenon. The 96 h-EC20 values of nSiO2 and mPS on H. akashiwo were 2.69 and 10.07 mg L-1, respectively, and chlorophyll fluorescence parameters indicated that the microalgal photosynthetic system were inhibited. The hydrophilic surface of nSiO2 increased the likelihood of nSiO2 binding to the hydrophilic functional group of microalgae, which may account for the slightly stronger toxic effect of nSiO2 than mPS. The algae continued to produce reactive oxygen species (ROS) under stress conditions. Total protein (TP) levels reduced, and superoxide dismutase (SOD) and catalase (CAT) levels increased to maintain ROS levels in the cells. The decrease in adenosine triphosphate (ATPase) indicated an impact on cellular energy metabolism. Cell membrane damage, cytoplasm and organelle efflux under stress were confirmed by scanning and transmission electron microscopy (SEM and TEM) images. This study contributes to the understanding of the size effect of MNPs on the growth of marine microalgae.

Microplastic-induced apoptosis and metabolism responses in marine Dinoflagellate, Karenia mikimotoi.

Microplastics (MPs) occur widely in marine environments, and disturb the balance of aquatic ecosystems. In this study, programmed cell apoptosis in marine dinoflagellate, Karenia mikimotoi exposed to 10 mg L-1 micro/nanoplastics (MPs/NPs; polystyrene and polymethyl methacrylate) for 72 h was assessed. Prior to the toxicity assay, MPs/NPs were dialyzed to remove possible additives. Cell viability, membrane integrity, cell apoptosis, and total DNA concentration were measured to assess programmed cell apoptosis in K. mikimotoi following exposure to MPs/NPs. A transcriptome analysis was used to explore the potential toxic mechanism of MPs to K. mikimotoi. Programmed cell apoptosis was related to the size of MPs/NPs, and NPs could more easily impair cell viability, and reduced cell membrane integrity and DNA concentration. NP particles caused continuous apoptosis of K. mikimotoi compared to MP particles. Size had the greatest effect on toxicity in K. mikimotoi. In conclusion, the results evidenced that both MPs and NPs have a negative impact on the marine dinoflagellate, K. mikimotoi. However, NPs were more harmful to K mikimotoi than MPs, highlighting the potential ecological problems associated with exposure to NPs.

The effects and mechanisms of polystyrene and polymethyl methacrylate with different sizes and concentrations on Gymnodinium aeruginosum.

In this study, Gymnodinium aeruginosum was exposed to polystyrene (PS) and polymethyl methacrylate (PMMA) of three particle sizes (0.1 µm, 1.0 µm and 100 µm) and two concentrations (10 mg/L and 75 mg/L) for 96 h. The density of algae cells, the endpoints that reactive oxygen species (ROS), total protein (TP), malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT), scanning and transmission electron microscopy (SEM and TEM) were used to explore the toxicity mechanism to the microalgae. At a concentration of 75 mg/L, the 96 h inhibition ratios (IR) with particle sizes of 0.1 µm, 1.0 µm and 100 µm on G. aeruginosum were 55.9%, 63.7% and 6.0% for PS, respectively, and 3.0%, 4.1% and -0.6% for PMMA, respectively. The most significant changes in ROS, TP, MDA, SOD and CAT were observed at 75 mg/L 1.0 µm of PS when treated for 96 h. When exposed to nanoplastics (NPs) and microplastics (MPs), the algae cells were damaged, and the antioxidant system was activated. Extracellular polymeric substance (EPS) could help to detoxify the algae. In general, PS was more toxic than PMMA. The toxicity of small MNPs (0.1 µm and 1.0 µm) was related to the concentrations, while large MNPs (100 µm) did not.

Near-infrared light excited UCNP-DNAzyme nanosensor for selective detection of Pb2+ and in vivo imaging.

Due to similar charges, atomic radii, and chemical properties of most metal ions, the selective sensing of these metal ions and imaging in vivo is still a challenge. A DNAzyme assemblied and near-infrared (NIR) light excited nanosensor was developed to detect and image Pb2+. In this nanosensor, NaYF4:Yb, Er upconversion nanoparticles (UCNPs) introduced as NIR-to-Vis transducer were the donor of luminescence resonance energy transfer (LRET), and DNAzyme-functionalized black hole quencher 1 (BHQ1) acted as energy transfer acceptor. This proposed nanosensor was applied to detecting Pb2+ in solution with high sensitivity and selectivity. Furthermore, we have successfully demonstrated the imaging ability of this nanosensor towords Pb2+ in living cells and early-stage zebrafish with negligible autofluorescence and good photostability. The UCNP-DNAzyme nanosensor would enrich the method of imaging Pb2+ in vivo, and might serve as a potential tool for understanding the metabolic pathways of Pb2+ and the mechanism of lead poisoning in biological system.

A turn-on near-infrared fluorescent probe for visualization of endogenous alkaline phosphatase activity in living cells and zebrafish.

Alkaline phosphatase (ALP) is an essential hydrolase and widely distributed in living organisms. It plays important roles in various physiological and pathological processes. Herein, a turn-on near-infrared (NIR) fluorescent probe (DXMP) was developed for sensitive detection of ALP activity both in vitro and in vivo based on the intramolecular charge transfer (ICT) mechanism. Upon incubation with ALP, DXMP exhibited a strong fluorescence increment at 640 nm, which was attributed to the fact that ALP-catalyzed cleavage of the phosphate group in DXMP induced the transformation of DXMP into DXM-OH. The probe exhibited prominent features including outstanding selectivity, high sensitivity, and excellent biocompatibility. More importantly, it has been successfully used to detect and image endogenous ALP in living cells and zebrafish.

A near-infrared fluorescent probe for monitoring and imaging of ß-galactosidase in living cells.

ß-Galactosidase (ß-gal) which is overexpressed in primary ovarian cancer can be employed as a valuable biomarker for ovarian cancer. Thus, monitoring and imaging endogenous ß-gal in living cells is of great importance. Herein, a dicyanoisophorone-based near-infrared (NIR) fluorescent probe 2-(5,5-dimethyl-3-((E)-4-(((2R,3S,4R,5S,6S)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)styryl)cyclohex-2-en-1-ylidene)malononitrile named DP-ßgal, was rationally designed and synthesized for the monitoring of ß-gal activity in living cells. In the presence of ß-gal, with the breaking of the glycosidic bond, the NIR fluorescence of the dicyanoisophorone derivative gradually recovered, enabling the fluorescence "off-on" quantitative determination of ß-gal activity. DP-ßgal has the advantages of good selectivity and high sensitivity for the detection of ß-gal, with the limit of detection (LOD) of 3.2 × 10-3 U. Furthermore, based on its advantages of long-wavelength emission and excellent biocompatibility, the practical applications of DP-ßgal in NIR imaging of ß-gal in living ovarian cancer cells (SKOV-3) were demonstrated.

Upconversion nanoparticles with bright red luminescence for highly sensitive quantifying alkaline phosphatase activity based on target-triggered fusing reaction.

Herein, we report a novel ultrasensitive upconversion intense red fluorescence and colorimetric dual-readout strategy for the determination of alkaline phosphatase (ALP) that initially integrates enzyme-triggered cascade signals amplification (ECSAm) with rapid fusing reaction of label-free silver triangular nanoplates (AgTNPs). The sensing strategy involves four aspects. Firstly, AgTNPs with an absorption band at ∼610 nm was synthesized, which can effectively quench upconversion nanoparticles (UCNPs) fluorescence at 670 nm through the fluorescence resonance energy transfer (FRET). Secondly, when in the presence of ALP, l-ascorbic acid 2-phosphate (AAP) was transformed into ascorbic acid (AA) which can react with KIO3 to produce I2. Thirdly, the procreant I2 can quickly adsorb onto the surface of AgTNPs, then etch AgTNPs and the I2 is reduced to I-. Fourthly, the generated I- can further accelerate the fusion of AgTNPs by adsorption effect, which helps achieve ECSAm, allowing the quantitative evaluation of ALP with a satisfying detection limit of 0.035 mU/mL. In addition, the developed method has been further applied to the detection of ALP in human serum with satisfactory results. These results indicate that the dual-readout assay with a well-defined response mechanism shows good prospects in physiological and pathological studies.