Preparation and characterisation of novel casein-gum Arabic composite microcapsules for targeted in vivo delivery of Lactiplantibacillus plantarum A3

The health benefits of probiotics in the body are predicated on their ability to remain viable in harsh gastrointestinal conditions and complex pathological microenvironments. Casein and gum Arabic (GA), with dual emulsifying and stabilising effects in colloidal systems. Therefore, the objective of this research was to develop a novel microcapsule to encapsulate Lactiplantibacillus plantarum A3 using casein and GA as wall materials to improve the survival of the bacteria during gastrointestinal digestion, storage and lyophilization. The casein and GA composite microcapsules were prepared and characterised by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that the microcapsules had stable morphology, uniform size and spherical shape. The results revealed that the encapsulation of microcapsules significantly improved the survival of L. plantarum A3 in gastrointestinal fluid environment (5.52 × 109 cfu/ml) and lyophilization treatment (6.25 × 109 cfu/ml). Furthermore, the microencapsulated L. plantarum A3 exhibited an improved ability to regulate intestinal microbiota by effectively increasing the relative abundance of Bacteroidetes, Proteobacteria and Actinobacteria and decreasing the relative abundance of Firmicutes in vivo. The findings of the study will help to design a lactic acid bacteria encapsulation system based on the gastrointestinal environment and provide a basis for the development of probiotic functional products.

Connecting particle interactions to agglomerate morphology and rheology of boehmite nanocrystal suspensions

HYPOTHESIS

The rheology of complex suspensions, such as nuclear waste slurries at the Hanford and Savannah River sites, imposes significant challenges on industrial-scale processing. Investigating the rheology and connecting it to the agglomerate morphology and underlying particle interactions in slurries will provide important fundamental knowledge, as well as prescriptive data for practical applications. Here, we use suspensions of nano-scale aluminum oxyhydroxide minerals in the form of boehmite as an analog of the radioactive waste slurry to investigate the correlation between particle interactions, agglomerate morphology, and slurry rheology.

EXPERIMENTS

A combination of Couette rheometry and small-angle scattering techniques (independently and simultaneously) were used to understand how agglomerate structure of slurry changes under flow and how these structural changes manifest themselves in the bulk rheology of the suspensions.

FINDINGS

Our experiments show that the boehmite slurries are thixotropic, with the rheology and structure of the suspensions changing with increasing exposure to flow. In the slurries, particle agglomerates begin as loose, system-spanning clusters, but exposure to moderate shear rates causes the agglomerates to irreversibly consolidate into denser clusters of finite size. The structural changes directly influence the rheological properties of the slurries such as viscosity and viscoelasticity. Our study shows that solution pH affects the amount of structural rearrangement and the kinetics of the rearrangement process, with an increase in pH leading to faster and more dramatic changes in bulk rheology, which can be understood via correlations between particle interactions and the strength of particle network. Nearly identical structural changes were also observed in Poiseuille flow geometries, implying that the observed changes are relevant in pipe flow as well.

Two-hit model of postintensive care syndrome induced by lipopolysaccharide challenge and subsequent chronic unpredictable stress in mice

Postintensive care syndrome (PICS) is defined as a new or worsening impairment in cognition, mental health, and physical function after critical illness. However, there is still a lack of a clinically relevant animal model. Thus, development of a PICS model is essential for understanding the mechanism underlying PICS and screening treatment methods for this neuropsychiatric disorder. The purpose of this study was to establish a clinically relevant PICS model based on the two-hit concept, in which lipopolysaccharide (LPS, 3 mg/kg) injection was served as the first hit and subsequent modified chronic unpredictable stress as the second hit. In order to pharmacologically verify the proposed model of PICS, we studied the effectiveness of fluoxetine to reverse the behavioral and molecular abnormalities in this model. In the present study, body- and adrenal weight changes proved our model was effective, as reflected by body weight loss, increased adrenals weight, and a significantly increased level of plasma corticosterone. Moreover, our PICS model displayed reproducible anxiety- and depression like behavior and cognitive impairments. Neurobiological investigations revealed a significant up-regulation of the microglial marker CD68 and pro-inflammatory cytokine IL-6 in the hippocampus of stressed mice. Notably, chronic treatment with fluoxetine for three weeks reversed most of the affected parameters. In summary, we believe that we have developed a new model of PICS that is clinically relevant, which could advance the mechanism research and the development of therapeutic strategies.

Differentiation between malignant and benign breast masses: combination of semi-quantitative analysis on DCE-MRI and histogram analysis of ADC maps

AIM

To investigate the performance of combined semi-quantitative analysis on dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) and histogram analysis of diffusion-weighted imaging (DWI) for distinguishing malignant from benign breast masses.

MATERIALS AND METHODS

This study included 178 patients with breast masses (benign:malignant=88:9) who underwent both DCE-MRI and DWI. The semi-quantitative parameters, derived from DCE-MRI, included maximum slope of increase (MSI), signal intensity slope (SI_slope), initial percentage of enhancement (E_initial), percentage of peak enhancement (E_peak), early signal enhancement ratio (ESER), and second enhancement percentage (SEP). Histogram parameters derived from apparent diffusion coefficient (ADC) maps included ADC_min, ADC_max, ADC_mean, ADC₁₀, ADC₂₅, ADC₅₀, ADC₇₅, ADC₉₀, skewness, and kurtosis. All parameters were compared between malignant and benign groups, and their differences were tested using independent-samples t-test or Mann-Whitney test. Receiver operating characteristic (ROC) curves were used to determine the diagnostic value of each significant parameter.

RESULTS

Among semi-quantitative parameters, SI_slope exhibited the best diagnostic performance in predicting malignancy (cut-off value, 0.096; ROC, 0.756; sensitivity, 86.7%; specificity, 61.4%). Among histogram parameters, ADC₁₀ exhibited the best diagnostic performance in predicting malignancy (cut-off value, 1.051; ROC, 0.885; sensitivity, 86.7%; specificity, 84.1%). The optimal diagnostic performance of combined ADC₁₀ and SI_slope (area under curve [AUC], 0.888; sensitivity, 82.2%; specificity, 95.5%) was significantly better than SI_slope alone (p<0.001). Moreover, the combination showed higher AUC (0.888 versus 0.885) than ADC₁₀ alone, but the difference was not statistically significant (p=0.914).

CONCLUSION

SI_slope and ADC₁₀ are significant predictors for breast malignancy. The combination of DCE-MRI and DWI improves differentiating performance.

Individual differences in the brain are associated with resilience versus susceptibility to lipopolysaccharide-induced memory impairment

Sepsis impairs learning and memory function, yet marked interindividual variability exists in the degree to which sepsis compromises learning and memory function. Thus, testing resilience versus susceptibility to systemic inflammation induced-memory impairment and the underlying mechanism is needed. In the present study, we firstly used lipopolysaccharide (LPS) to induce memory impairment, and then evaluated cognitive function on days 4-7 after the first LPS challenge. Subjects' scores on both behavioral measures were subjected to a hierarchical cluster analysis, identifying two clusters that differed notably on the Y-maze and fear conditioning tests. This analysis divided these subjects into two groups, one cluster (13 of 34 subjects) displayed impaired working and associative memory, named "Susceptive". The remaining cluster (21 of 34 subjects) showed normal memory, named "Resilient". We have also included another group receiving normal saline to serve as the control group. The three groups underwent a battery of biochemical detections. In addition, we investigated whether the individual differences would disappear between the "Resilient" and "Susceptive" groups by using microglia inhibitor minocycline. We showed that as compared with the "Resilient" or control group, the "Susceptive" group was accompanied by increased tumor necrosis factor-alpha, interleukin-1beta (IL-1β), IL-6, and biomarkers of microglia activation ionized calcium binding adaptor molecule-1 and cluster of differentiation 68. Notably, after decreasing the activation of microglia, the differences in cognitive function between the "Resilient" and "Susceptive" groups disappeared. Collectively, our study suggests that individual differences in the brain are associated with resilience versus susceptibility to LPS-induced memory impairment.

Citrullinated vimentin stimulates proliferation, pro-inflammatory cytokine secretion, and PADI4 and RANKL expression of fibroblast-like synoviocytes in rheumatoid arthritis

OBJECTIVES

We aimed to investigate the possible effects of vimentin (Vim) and citrullinated Vim (cVim) on proliferation capacity, pro-inflammatory cytokine secretion, and the expression of peptidylarginine deiminase type 4 (PADI4) and receptor activator of nuclear factor kappa B ligand (RANKL) in cultured fibroblast-like synoviocytes (FLSs) from rheumatoid arthritis (RA) and osteoarthritis (OA) patients.

METHOD

Human native Vim was citrullinated with rabbit PAD in vitro and detected using a Western blot assay with anti-modified citrulline antibody (anti-MC Ab). FLSs from RA or OA synovial samples were stimulated with Vim or cVim. Cell proliferation capacity was determined using the Celltiter 96 AQueous cell proliferation assay. The concentrations of tumour necrosis factor (TNF)-α, interleukin (IL)-1, and IL-17 were measured by enzyme-linked immunosorbent assay (ELISA). The expression of PADI4 and RANKL was measured by real-time polymerase chain reaction (RT-PCR) and a Western blot assay.

RESULTS

Our Western blot assay with anti-MC Ab indicated that the amount of cVim increased significantly after Vim had been incubated with rabbit PAD in vitro. The proliferation capacity and secretion of TNF-α and IL-1 were significantly enhanced in the FLSs of RA patients when treated with cVim. However, when treated with Vim, an inhibitory effect on the proliferation capacity was noted in the FLSs from RA and also from OA patients. cVim significantly increased the expression of PADI4 and RANKL in the FLSs from RA patients.

CONCLUSION

cVim seems to have remarkable biological effects on RA as confirmed by the stimulation of proliferation capacity, pro-inflammatory cytokine secretion, and PADI4 and RANKL expression in the FLSs of RA patients.

Comparative proteomic analysis for the detection of biomarkers in pancreatic ductal adenocarcinomas

AIMS

To search for novel potential protein biomarkers for the early detection and better intervention of pancreatic ductal adenocarcinoma (PDAC).

METHODS

Eight pairs of matched PDAC and non-cancerous pancreas tissues were profiled with two-dimensional electrophoresis; differentially expressed proteins were identified by mass spectrometry. Expression patterns of TBX4 (T-box transcription factor TBX4) and HSP60 (60 KDa heat shock protein) were studied with immunohistochemistry using tissue microarrays.

RESULTS

A total of 48 differentially expressed proteins were identified; 30 of them are novel potential biomarkers. Immunohistochemistry showed that TBX4 expression could be seen in both centroacinar cells and small ducts in normal pancreas and tumour cells in 5/5 (100%) well differentiated, 35/38 (92.1%) moderately differentiated, and 11/18 (61.1%) poorly differentiated PDAC tissues with different staining intensity. However, in normal acinar cells and tumour cells in the other 3/38 (7.9%) moderately differentiated and 7/18 (38.9%) poorly differentiated PDAC tissues, there was no visible TBX4 expression. The expression difference of TBX4 between moderately differentiated and poorly differentiated PDAC tissues was statistically significant (p<0.01). In addition, there was obvious morphology difference between TBX4 negatively stained and positively stained tumour cells, which suggests different cellular origins. Strong expression of HSP60 could be seen in both acinar cells and small ducts in normal pancreas tissues and tumour cells in PDAC tissues except for islets and tumour stoma; no correlation was found between HSP60 expression and differentiation of PDAC tissues.

CONCLUSIONS

30 novel potential biomarkers differentially expressed in PDAC tissues were identified. TBX4 may be a differentiation related protein; its prognostic value for PDAC deserves further study.