Cytomegalovirus Shedding in Healthy Seropositive Female College Students: A 6-Month Longitudinal Study.

Background: Cytomegalovirus (CMV) establishes a lifelong latent infection after primary infection and may reactivate periodically, with the shedding of infectious virus in body fluids. To better understand the prevalence and shedding model of CMV in immunocompetent seropositive women of childbearing age, a 6-month longitudinal study was conducted in healthy female college students. Methods: A total of 102 nonpregnant female college students aged 18-30 years were enrolled and followed up every 2 weeks for 6 months. Saliva and urine samples were collected at each visit. Serum samples were collected at the first and last visits. Results: All participants were positive for anti-CMV immunoglobulin G (IgG) at entry. During the 6-month period, 29.4% of participants (30 of 102) shed CMV intermittently in saliva or urine. At each visit, the CMV shedding prevalence varied from 2.0% to 10.4% and presented only in 1 bodily fluid. The viral load was low and did not induce marked antibody increases. The baseline anti-CMV IgG level was not found to be associated with viral shedding. Conclusions: CMV shedding in saliva and urine is common and intermittent and does not stimulate an anamnestic antibody response in seropositive immunocompetent women of childbearing age with a low risk of exposure to exogenous infectious sources.

Enhancing aggregation of microalgae on polystyrene microplastics by high light: Processes, drivers, and environmental risk assessment.

Microplastics (MPs) are emerging pollutants, causing potential threats to aquatic ecosystems and serious concern in aggregating with microalgae (critical primary producers). When entering water bodies, MPs are expected to sink below the water surface and disperse into varying water compartments with different light intensities. However, how light influences the aggregation processes of algal cells onto MPs and the associated molecular coupling mechanisms and derivative risks remain poorly understood. Herein, we investigated the aggregation behavior between polystyrene microplastics (mPS, 10 µm) and Chlorella pyrenoidosa under low (LL, 15 µmol·m-2·s-1), normal (NL, 55 µmol·m-2·s-1), and high light (HL, 150 µmol·m-2·s-1) conditions from integrated in vivo and in silico assays. The results indicated that under LL, the mPS particles primarily existed independently, whereas under NL and HL, C. pyrenoidosa tightly bounded to mPS by secreting more protein-rich extracellular polymeric substances. Infrared spectroscopy analysis and density functional theory calculation revealed that the aggregation formation was driven by non-covalent interaction involving van der Waals force and hydrogen bond. These processes subsequently enhanced the deposition and adherence capacity of mPS and relieved its phytotoxicity. Overall, our findings advance the practical and theoretical understanding of the ecological impacts of MPs in complex aquatic environments.

Invasion of Trifolium repens L. aggravated by biodegradable plastics: adjustable strategy for foraging N and P.

The invasion of alien plant and the pollution caused by soil microplastics have emerged as significant ecological threats. Recent studies have demonstrated aggravating effect of non-biodegradable microplastics on plant invasion. However, the impact of biodegradable microplastics (BMPs) on plant invasion remains unclear. Therefore, it is imperative to explore the impact of BMPs on plant invasion. In this study, a 30-day potting experiment with Trifolium repens L. (an invasive plant) and Oxalis corniculata L. (a native plant) was conducted to evaluate the influence of BMPs on T. repens's invasion. The findings revealed that BMPs results in a reduction in available N and P contents, thereby facilitating the colonization of arbuscular mycorrhizal fungi on T. repens 's roots. Consequently, T. repens adjusted its N and P foraging strategy by increasing P absorption ratio, and enhancing the accumulation of N and P in leaves. This ultimately led to the decrease of relative neighbor effect index of T. repens, indicating an aggravated invasion by T. repens. This study significantly enhances and expands the understanding of mechanisms by which microplastics aggravate plant invasion.

Stealth microplastics pollutants: Toxicological evaluation of polyethylene terephthalate-based glitters on the microalga Desmodesmus sp. and its color effect.

Polyethylene terephthalate-based glitters (PET glitters) are a potential source of primary microplastics in the environment. However, the bioeffects of PET glitters and the associated leachates remain largely unknown. In this study, we investigated the individual and combined toxicity of five colors (silver, black, red, green, and blue) of PET glitters and their corresponding leachates on the cellular responses of Desmodesmus sp. The results indicated that the photosynthesis of Desmodesmus sp. could be partly affected by PET glitters through the shading effect, but not that of growth. Conversely, the leachates of red and green PET glitters significantly inhibited the growth of the microalga, suggesting a higher risk associated with additives leached from these colors of PET glitters. Furthermore, the adverse effects of the co-occurrence of PET glitters and leachates were closely related to oxidative stress responses in the microalgal cells, along with a color effect, which could be mainly attributed to variations in the composition and abundance of toxic additives in different colors of PET glitters. Overall, our findings provide insights into the ecological risks posed by glitters in aquatic environments and emphasize the importance of considering color factors in assessing microplastics toxicity.

In vitro and in vivo evaluation of immune response of poly(lactic acid) nanoparticles with different end groups.

Poly(lactic acid) (PLA) has excellent properties of biodegradability and biocompatibility, which is a US Food and Drug Administration (FDA) approved biopolymer for the preparation of safe and effective vaccines, drugs, and gene delivery systems. However, there still exists a great problem whether and how the end group affects the immune response of PLA vaccines. Therefore, the aim of this study was to evaluate the in vitro and in vivo of immune response of PLA nanoparticles (NPs) with carboxyl (COOH) and ester (COOR) end groups. In vitro experiments suggested COOH NPs could promote the higher phagocytosis and activation of bone marrow dendritic cells (BMDCs) with a lower cytotoxicity. In vivo experiments showed that COOR NPs and COOH NPs could strongly elicit IgG, IgG1, and IgG2a responses both in the short and long-terms. However, the highest T cell and B cell activation, and central memory T cells response was induced by COOH NPs. In addition, the COOH NPs could significantly enhance splenocytes proliferation and cytokines secretion. Thus, the PLA with the COOH end group shows greater potential as efficient carrier materials of NPs for enhancing cellular and humoral immune responses.

Poor Oral Health and Risk of Incident Dementia: A Prospective Cohort Study of 425,183 Participants.

BACKGROUND: The association between poor oral health and the risk of incident dementia remains unclear. OBJECTIVE: To investigate the associations of poor oral health with incident dementia, cognitive decline, and brain structure in a large population-based cohort study. METHODS: A total of 425,183 participants free of dementia at baseline were included from the UK Biobank study. The associations between oral health problems (mouth ulcers, painful gums, bleeding gums, loose teeth, toothaches, and dentures) and incident dementia were examined using Cox proportional hazards models. Mixed linear models were used to investigate whether oral health problems were associated with prospective cognitive decline. We examined the associations between oral health problems and regional cortical surface area using linear regression models. We further explored the potential mediating effects underlying the relationships between oral health problems and dementia. RESULTS: Painful gums (HR = 1.47, 95% CI [1.317-1.647], p < 0.001), toothaches (HR = 1.38, 95% CI [1.244-1.538], p < 0.001), and dentures (HR = 1.28, 95% CI [1.223-1.349], p < 0.001) were associated with increased risk of incident dementia. Dentures were associated with a faster decline in cognitive functions, including longer reaction time, worse numeric memory, and worse prospective memory. Participants with dentures had smaller surface areas of the inferior temporal cortex, inferior parietal cortex, and middle temporal cortex. Brain structural changes, smoking, alcohol drinking, and diabetes may mediate the associations between oral health problems and incident dementia. CONCLUSION: Poor oral health is associated with a higher risk of incident dementia. Dentures may predict accelerated cognitive decline and are associated with regional cortical surface area changes. Improvement of oral health care could be beneficial for the prevention of dementia.

Boron-mediated lignin metabolism in response to aluminum toxicity in citrus (Poncirus trifoliata (L.) Raf.) root.

Aluminum (Al) toxicity has conspicuous detrimental effects on citrus production whereas boron (B) has been shown to alleviate its toxicity. Lignin plays a critical role in the cell wall extensibility and root elongation under stressed conditions. Hence, the interaction between B and Al on cell wall structure and lignin-related metabolic pathway was investigated in root of trifoliate orange (Poncirus trifoliata (L.) Raf.) seedlings. The results showed B supply considerably decreased the Al content in root, particularly in cell wall, and reduced Al-induced damage on growth-related parameters and thickness of cell wall. Boron application decreased the hydrogen peroxide (H2O2), malondialdehyde (MDA), and lignin contents in the Al-treated root, which prevents the inhibitory effects of Al on the root length. Moreover, metabonomics results showed that B addition resulted in the reduction of metabolites involved in the lignin biosynthesis pathways (phenylpropanoid metabolic) i.e., shikimic acid, tyrosine, caffeic acid, chlorogenic acid, coniferyl alcohol, sinapinic acid, sinapaldehyde, and sinapyl alcohol, as well as distinctively restrain the activities of lignin biosynthesis-related enzymes (4-coumarate-CoA ligase (4CL), cinnamyl-alcohol dehydrogenase (CAD)) under Al toxicity. Collectively, our findings suggest that the positive effects of B on the resistance of Al toxicity may be it reduces Al accumulation in the cell wall, lignin biosynthesis, and cell wall thickness, thereby increasing the extensibility and elasticity of cell wall and thus promoting root elongation.

Dimeric artesunate phospholipid-conjugated liposomes as promising anti-inflammatory therapy for rheumatoid arthritis.

OBJECTIVE: The dimeric artesunate phospholipid conjugate (Di-ART-GPC) is a novel amphipathic artemisinin derivative, which can be assembled into liposomes. Di-ART-GPC liposomes were prepared and evaluated as potential anti-inflammatory agents for rheumatic arthritis (RA). METHODS: Di-ART-GPC was assembled into liposomes utilizing thin film dispersion-high pressure homogenization. Dynamic light scattering (DLS), transmission electron microscopy (TEM), and electron cryo microscopy (cryo-EM) were employed to characterize the liposomal size and morphology. The in vitro cytotoxicity of the Di-ART-GPC liposomes was assessed using Cell Counting Kit-8 (CCK8). The anti-inflammatory effects were studied utilizing the inflammatory cell model. Finally, the in vivo efficacy of the Di-ART-GPC-conjugated liposomes was investigated using the arthritis rat model. RESULTS: The particle size of the Di-ART-GPC liposomes decreased to a narrow range of approximately 70 nm following high-pressure homogenization. The in vitro studies revealed low cytotoxicity and good anti-inflammatory effects of the Di-ART-GPC liposomes, which exhibited significantly higher inhibition of the cell secretion of pro-inflammatory cytokines than ART. The in vivo evaluation confirmed that treatment with Di-ART-GPC resulted in a decline in the ankle swelling rate and a low inflammatory response compared with the model control and ART. CONCLUSION: Di-ART-GPC liposomes demonstrate remarkable potential as novel ART-based anti-inflammatory agents for RA.

An acoustic/thermo-responsive hybrid system for advanced doxorubicin delivery in tumor treatment.

The efficiency of drug delivery and bioavailability to tumor cells are crucial for effective cancer chemotherapy. Herein, a doxorubicin (DOX) encapsulated lysolipid-based thermosensitive liposome decorated with cRGD peptide (RTSL) is conjugated on the surface of an IR780-loaded microbubble (IMB) to synthesize RTSL-IMBs. Sequentially taking advantage of acoustic-assisted early extravasation and thermo-triggered interstitium ultrafast drug release, RTSL-IMBs combine with ultrasound (US) and laser irradiation can advance drug delivery and bioavailability. In vitro experiments demonstrate that RTSL-IMBs associated with a two-step protocol (subsequently US irradiation for 1 min and laser irradiation for 5 min) can dramatically enhance the cellular uptake and bioavailability of DOX. In vivo fluorescence imaging studies reveal that the combination of RTSL-IMBs and US shows a 2.8-fold intratumoral drug accumulation increase at 0.5 h post-injection, while it will take 48 h to reach the same level of intratumoral drug accumulation for the RTSL-IMB group alone. Interestingly, the following localized application of a laser can further increase drug accumulation and slow tumor clearance. Histological analysis demonstrates that the combinational RTSL-IMBs, US and laser significantly improve the drug penetration distance and delivery efficiency in the tumor core. In this study, the acoustic/thermo-responsive hybrid system shows potential for advancing DOX chemotherapy in breast cancer cell MCF-7 xenograft nude mice.

Identification of a microglial activation-dependent antidepressant effect of amphotericin B liposome.

Chronic stress-induced decline in microglia in the hippocampus is a newly hypothesized mechanism of depression, and reversal of this decline by microglial activators has been shown to suppress depression-like behaviors in mice. This suggests that activation of immune cells in the hippocampus may be a potential strategy for depression therapy. Since amphotericin B, an anti-fungal medication, is known to activate macrophages and microglia, we investigated whether conventional amphotericin B or its liposomal form displays antidepressant activity. Our results showed that both amphotericin B and its liposomal form at various doses induced obvious depression-like behaviors in naïve mice, likely owing to increased serum interleukin-6 (IL-6) and IL-1ß levels. However, under stressed conditions, amphotericin B liposome, but not amphotericin B itself, reversed chronic unpredictable stress (CUS)-induced increase in immobility time in the tail suspension test and forced swim test as well as CUS-induced decrease in sucrose intake in the sucrose preference test and the time spent in the center region of the open field test in a dose-dependent manner. Immunofluorescence analysis showed that amphotericin B liposome reversed the CUS-induced decline in dentate gyrus (DG) microglia, and inhibition or ablation of microglia in the hippocampus by minocycline (40 mg/kg) or PLX3397 pre-treatment (290 mg/kg) abrogated the antidepressant effect of the amphotericin B liposome in CUS-treated mice. These results not only identify a novel pharmacological effect of amphotericin B liposome, but further support the notion that microglial activation in the hippocampus is a potential strategy for depression therapy.