Search

Despite a great deal of prior research, the early pathogenic events in natural oral poliovirus infection remain poorly defined. To establish a model for study, we infected 39 macaques by feeding them single high doses of the virulent Mahoney strain of wild type 1 poliovirus. Doses ranging from 107 to 109 50% tissue culture infective doses (TCID50) consistently infected all the animals, and many monkeys receiving 108 or 109 TCID50 developed paralysis. There was no apparent difference in the susceptibilities of the three macaque species (rhesus, cynomolgus, and bonnet) used. Virus excretion in stool and nasopharynges was consistently observed, with occasional viremia, and virus was isolated from tonsils, gut mucosa, and draining lymph nodes. Viral replication proteins were detected in both epithelial and lymphoid cell populations expressing CD155 in the tonsil and intestine, as well as in spinal cord neurons. Necrosis was observed in these three cell types, and viral replication in the tonsil/gut was associated with histopathologic destruction and inflammation. The sustained response of neutralizing antibody correlated temporally with resolution of viremia and termination of virus shedding in oropharynges and feces. For the first time, this model demonstrates that early in the infectious process, poliovirus replication occurs in both epithelial cells (explaining virus shedding in the gastrointestinal tract) and lymphoid/monocytic cells in tonsils and Peyer's patches (explaining viremia), extending previous studies of poliovirus pathogenesis in humans. Because the model recapitulates human poliovirus infection and poliomyelitis, it can be used to study polio pathogenesis and to assess the efficacy of candidate antiviral drugs and new vaccines.IMPORTANCE Early pathogenic events of poliovirus infection remain largely undefined, and there is a lack of animal models mimicking natural oral human infection leading to paralytic poliomyelitis. All 39 macaques fed with single high doses ranging from 107 to 109 TCID50 Mahoney type 1 virus were infected, and many of the monkeys developed paralysis. Virus excretion in stool and nasopharynges was consistently observed, with occasional viremia; tonsil, mesentery lymph nodes, and intestinal mucosa served as major target sites of viral replication. For the first time, this model demonstrates that early in the infectious process, poliovirus replication occurs in both epithelial cells (explaining virus shedding in the gastrointestinal tract) and lymphoid/monocytic cells in tonsils and Peyer's patches (explaining viremia), thereby supplementing historical reconstructions of poliovirus pathogenesis. Because the model recapitulates human poliovirus infection and poliomyelitis, it can be used to study polio pathogenesis, candidate antiviral drugs, and the efficacy of new vaccines.

Chestnuts become sweetened with better tastes for fried products after cold storage, but the possible mechanism is not clear. The dynamics of sugar components and related physiological responses, as well as the possible molecular mechanism in chestnuts during cold storage, were investigated. Sucrose accumulation and starch degradation contributed to taste improvement. Sucrose content reached the peak after two months of cold storage, along with the accumulation of reducing sugars of maltose, fructose and glucose to a much lesser extent. Meanwhile, alpha-amylase and beta-amylase maintained high levels, and the activities of acid invertase and sucrose synthase increased. Transcriptome data demonstrated that differentially expressed genes (DEGs) were significantly enriched in the process of starch and sucrose metabolism pathway, revealing the conversion promotion of starch to sucrose. Furthermore, DEGs involved in multiple phytohormone biosynthesis and signal transduction, as well as the transcription regulators, indicated that sucrose accumulation might be interconnected with the dormancy release of chestnuts, with over 90% germinated after two months of cold storage. Altogether, the results indicated that cold storage improved the taste of chestnuts mainly due to sucrose accumulation induced by DEGs of starch and sucrose metabolism pathway in this period, and the sweetening process was interconnected with dormancy release. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) is a temporally and spatially precisely controllable, noninvasive, and potentially highly efficient method of phototherapy. The three components of PDT primarily include photosensitizers, oxygen, and light. PDT employs specific wavelengths of light to active photosensitizers at the tumor site, generating reactive oxygen species that are fatal to tumor cells. Nevertheless, traditional photosensitizers have disadvantages such as poor water solubility, severe oxygen‐dependency, and low targetability, and the light is difficult to penetrate the deep tumor tissue, which remains the toughest task in the application of PDT in the clinic. Here, we systematically summarize the development and the molecular mechanisms of photosensitizers, and the challenges of PDT in tumor management, highlighting the advantages of nanocarriers‐based PDT against cancer. The development of third generation photosensitizers has opened up new horizons in PDT, and the cooperation between nanocarriers and PDT has attained satisfactory achievements. Finally, the clinical studies of PDT are discussed. Overall, we present an overview and our perspective of PDT in the field of tumor management, and we believe this work will provide a new insight into tumor‐based PDT. [ABSTRACT FROM AUTHOR]

Penicillium italicum, a major postharvest pathogen, causes blue mold rot in citrus fruits through the deployment of various virulence factors. Recent studies highlight the role of the epigenetic reader, SntB, in modulating the pathogenicity of phytopathogenic fungi. Our research revealed that the deletion of the SntB gene in P. italicum led to significant phenotypic alterations, including delayed mycelial growth, reduced spore production, and decreased utilization of sucrose. Additionally, the mutant strain exhibited increased sensitivity to pH fluctuations and elevated iron and calcium ion stress, culminating in reduced virulence on Gannan Novel oranges. Ultrastructural analyses disclosed notable disruptions in cell membrane integrity, disorganization within the cellular matrix, and signs of autophagy. Transcriptomic data further indicated a pronounced upregulation of hydrolytic enzymes, oxidoreductases, and transport proteins, suggesting a heightened energy demand. The observed phenomena were consistent with a carbon starvation response potentially triggering apoptotic pathways, including iron-dependent cell death. These findings collectively underscored the pivotal role of SntB in maintaining the pathogenic traits of P. italicum, proposing that targeting PiSntB could offer a new avenue for controlling citrus fungal infections and subsequent fruit decay. [ABSTRACT FROM AUTHOR]

AbstractErastin is the most classical small molecular ferroptosis inducer but its clinical application is hindered due to its poor solubility. Nanotechnology has been used to improve ferroptosis inducer erastin’s solubility. The recently reported erastin-incorporated nanosystems (e.g., nanoparticulate ferritin, poly(ethylene glycol) methyl ether-blockpoly(lactide-co-glycolide) (mPEG-PLGA) nanoparticle, exosome, and liposome) could to some degree elevate its solubility, but were still poor in loading capacity. To be specific, the maximum entrapment efficiency and drug loading in previous studies were approximately 36% and 3.7%, respectively. In order to improve drug loading capacity, we constructed a novel carrier based on Vitamin E d-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) and polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (Soluplus®) blended micelles. The erastin@TPGS/Soluplus® micelles were prepared by thin film hydration method, and formulation details including dosage of Soluplus®, the weight ratio of TPGS to Soluplus®, the weight ratio of erastin to TPGS/Soluplus® were optimized. The physicochemical properties of the erastin micelles were measured by DLS, TEM, FTIR, and TG-DSC analysis. The products exhibited a nanoscale and uniform particle size (78.11 ± 0.54 nm) and neutral surface charge (-0.43 ± 0.32 mV). Significantly improved entrapment efficiency (89.63 ± 1.81%) and drug loading rate (10.03 ± 0.14%) were obtained, which was over 2-fold of current reports. The in vitro release study demonstrated that erastin could release in a sustained yet complete manner, and the drug release might be governed by multiple mechanisms including anomalous diffusion of non-Fickian diffusion, matrix erosion and sustained release. In summary, this proposed erastin nanosystem provides a new strategy for improving loading capacity, and may probably augment ferroptosis-inducing therapy for cancer treatment. [ABSTRACT FROM AUTHOR]

This paper investigates a novel correction technique for the unsteady subsonic wing–body interference model. The correction technique considers the unsteady forces on the lifting boxes and the body elements of an idealized aircraft model. The chosen simulation model was a passenger aircraft, and the transonic unsteady aerodynamics in sinusoidal pitch motion at four different frequencies are analyzed. The unsteady aerodynamics of the uncorrected DLM (doublet lattice method), ECFT (enhanced correction factor technique) and the new unsteady wing–body correction method are compared to the unsteady CFD simulation results. The results show that when the frequency is small, the new unsteady wing–body correction method can obtain certain benefits in terms of accuracy, for the lifting boxes and the body elements as well. [ABSTRACT FROM AUTHOR]