γ-Cyclodextrin encapsulated thymol for citrus preservation and its possible mechanism against Penicillium digitatum.

The volatility of essential oils greatly limits their industrial applications. Here, we successfully prepared γ-cyclodextrin (γ-CD) inclusion compounds (γ-CDTL) containing thymol (TL) for the control of green mold caused by Penicillium digitatum (P. digitatum) in citrus fruit. In vitro experiment showed that the minimum fungicidal concentration (MFC) of γ-CDTL against the hyphae growth of P. digitatum was 2.0 g/L, and 8 × MFC treatment significantly reduced the occurrence of green mold in citrus fruit and had no adverse effect on fruit quality in vivo test compared to prochloraz. Scanning electron microscopy (SEM), x-ray diffraction (XRD), fourier transform-infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), physical properties and sustained release properties were also performed, results indicated that the hydrogen bonds between TL and γ-CD were the basis for the formation of γ-CDTL. We further investigated the inhibition mechanism of γ-CDTL. SEM and TEM experiments showed that γ-CDTL treatment caused severe damage to the hyphal morphology and cells in 30 min and disrupted the permeability of P. digitatum mycelial cell walls by increasing the chitinase activity, thus accelerating the leakage of intracellular lysates. However, the integrity of the cell membrane was obviously damaged only after 60 min of treatment. In conclusion, we prepared a novel inclusion complex γ-CDTL with obvious antifungal effects and preliminarily elucidated its inclusion mechanism and antifungal mechanism. γ-CDTL might be a potent alternative to chemical fungicides for controlling the postharvest decay of citrus.

γ-Cyclodextrin-Encapsulated Cinnamaldehyde for Citrus Preservation and Its Potential Mechanisms against Penicillium digitatum.

In this study, a γ-cyclodextrin-cinnamaldehyde inclusion compound (γ-CDCL) was prepared to control green mold caused by Penicillium digitatum (P. digitatum) in citrus. The results showed that the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of γ-CDCL against the mycelial growth of P. digitatum were 2.0 g L-1 and 4.0 g L-1, respectively. Simultaneously, eight × MFC γ-CDCL could effectively reduce the incidence of green mold in citrus fruit without impairment of the fruit qualities, meanwhile, eight × MFC γ-CDCL was comparable to Prochloraz in controlling fruit under natural storage conditions. The structure of γ-CDCL was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), and nuclear magnetic resonance (NMR) analyses. Results showed that the successful preparation of γ-CDCL was due to the spatial interaction between H-4,8 of cinnamaldehyde and H-5' of γ-cyclodextrin. Meanwhile, the cell membrane permeability of P. digitatum was impaired by γ-CDCL through massive accumulation of reactive oxygen species, whereas the cell wall integrity was barely affected. These results indicated that γ-CDCL might inhibit the growth of P. digitatum through a membrane damage mechanism and it is a promising alternative to chemical fungicides in controlling the post-harvest citrus decay.

The E484K Substitution in a SARS-CoV-2 Spike Protein Subunit Vaccine Resulted in Limited Cross-Reactive Neutralizing Antibody Responses in Mice.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), especially emerging variants, poses an increased threat to global public health. The significant reduction in neutralization activity against the variants such as B.1.351 in the serum of convalescent patients and vaccinated people calls for the design of new potent vaccines targeting the emerging variant. However, since most vaccines approved and in clinical trials are based on the sequence of the original SARS-CoV-2 strain, the immunogenicity and protective efficacy of vaccines based on the B.1.351 variant remain largely unknown. In this study, we evaluated the immunogenicity, induced neutralization activity, and protective efficacy of wild-type spike protein nanoparticle (S-2P) and mutant spike protein nanoparticle (S-4M-2P) carrying characteristic mutations of B.1.351 variant in mice. Although there was no significant difference in the induction of spike-specific IgG responses in S-2P- and S-4M-2P-immunized mice, neutralizing antibodies elicited by S-4M-2P exhibited noteworthy, narrower breadth of reactivity with SARS-CoV-2 variants compared with neutralizing antibodies elicited by S-2P. Furthermore, the decrease of induced neutralizing antibody breadth at least partly resulted from the amino acid substitution at position 484. Moreover, S-4M-2P vaccination conferred insufficient protection against live SARS-CoV-2 virus infection, while S-2P vaccination gave definite protection against SARS-CoV-2 challenge in mice. Together, our study provides direct evidence that the E484K substitution in a SARS-CoV-2 subunit protein vaccine limited the cross-reactive neutralizing antibody breadth in mice and, more importantly, draws attention to the unfavorable impact of this mutation in spike protein of SARS-CoV-2 variants on the induction of potent neutralizing antibody responses.

Clinical study on surgical treatment of granulomatous lobular mastitis.

BACKGROUND: The etiology and pathogenesis of granulomatous lobular mastitis (GLM) remain unknown, with no unified evaluation criteria or standard treatments. This study aimed to assess the etiology and features of GLM, as well as the effects of surgery (lesion excision + stage I breast reconstruction; LE + BR) for GLM. METHODS: This study evaluated 178 female GLM patients retrospectively in 2006-2015. The surgery and non-surgery groups included 164 and 14 patients, respectively. All patients received conservative therapy (traditional Chinese medicine combined with regional wet compress and pus drainage). In addition, the surgery group (n=164) underwent LE + BR. Clinical data, including disease course, causes, lesion size, marital status, and treatment approaches, were assessed. RESULTS: Follow-up was 13-117 months. Seventy-five of the 178 patients had no overt causes (42.1%); meanwhile, 63 (35.4%) and 16 (9.0%) had congenital nipple retraction and a history of psychotropic drugs for >1 year, respectively. The surgery group showed lesions significantly shrunk (≤1 quadrant) with acute inflammation fully controlled; 8 showed recurrence, indicating a cure rate of 95.1% (156/164). In the non-surgery group, 4 cases showed relapse after 6-14 months (cure rate =71.4%; 10/14). Therefore, surgical treatment was significantly more efficient than non-surgical treatment (P=0.001). Kaplan-Meier survival curves for the two treatment types showed a significant difference in recurrence (log rank =11.84, P<0.001). CONCLUSIONS: In GLM patients, LE + BR is safe and effective with respect to cosmetic results, recovery time, and recurrence. Successful surgery should be performed for patients whose lesions ≤1 quadrant, aim to achieve optimal GLM treatment.

Intranasal H102 Peptide-Loaded Liposomes for Brain Delivery to Treat Alzheimer's Disease.

PURPOSE: H102, a novel ß-sheet breaker peptide, was encapsulated into liposomes to reduce its degradation and increase its brain penetration through intranasal administration for the treatment of Alzheimer's disease (AD). METHODS: The H102 liposomes were prepared using a modified thin film hydration method, and their transport characteristics were tested on Calu-3 cell monolayers. The pharmacokinetics in rats' blood and brains were also investigated. Behavioral experiments were performed to evaluate the improvements on AD rats' spatial memory impairment. The neuroprotective effects were tested by detecting acetylcholinesterase (AchE), choline acetyltransferase (ChAT) and insulin degrading enzyme (IDE) activity and conducting histological assays. The safety was evaluated on rats' nasal mucosa and cilia. RESULTS: The liposomes prepared could penetrate Calu-3 cell monolayers consistently. After intranasal administration, H102 could be effectively delivered to the brain, and the AUC of H102 liposomes in the hippocampus was 2.92-fold larger than that of solution group. H102 liposomes could excellently ameliorate spatial memory impairment of AD model rats, increase the activities of ChAT and IDE and inhibit plaque deposition, even in a lower dosage compared with H102 intranasal solution. H102 nasal formulations showed no toxicity on nasal mucosa. CONCLUSIONS: The H102-loaded liposome prepared in this study for nasal administration is stable, effective and safe, which has great potential for AD treatment.

Feasibility of ß-sheet breaker peptide-H102 treatment for Alzheimer's disease based on ß-amyloid hypothesis.

ß-amyloid hypothesis is the predominant hypothesis in the study of pathogenesis of Alzheimer's disease. This hypothesis claims that aggregation and neurotoxic effects of amyloid ß (Aß) is the common pathway in a variety of etiological factors for Alzheimer's disease. Aß peptide derives from amyloid precursor protein (APP). ß-sheet breaker peptides can directly prevent and reverse protein misfolding and aggregation in conformational disorders. Based on the stereochemical structure of Aß1-42 and aggregation character, we had designed a series of ß-sheet breaker peptides in our previous work and screened out a 10-residue peptide ß-sheet breaker peptide, H102. We evaluated the effects of H102 on expression of P-tau, several associated proteins, inflammatory factors and apoptosis factors, and examined the cognitive ability of APP transgenic mice by behavioral test. This study aims to validate the ß-amyloid hypothesis and provide an experimental evidence for the feasibility of H102 treatment for Alzheimer's disease.