Phthalyl starch nanoparticles as prebiotics enhanced nisin production in Lactococcus lactis through the induction of mild stress in probiotics

AIM OF THE STUDY

Effect of internalized phthalyl starch nanoparticles (PSNs) on the antimicrobial ability of Lactococcus lactis (LL) KCTC 2013.

METHODS AND RESULTS

Phthalyl starch nanoparticles were prepared by self-assembly of phthalyl starch and the amount of the hydrophobic phthalic moieties were characterized by nuclear magnetic resonance: PSN1 (DS: 14·3 mol.%), PSN2 (DS: 17·8 mol.%) and PSN3 (DS: 30·4 mol.%). The sizes of PSN1, PSN2 and PSN3 measured by dynamic light scattering were 364·7, 248·4 and 213·4 nm, respectively, and the surface charges of PSNs measured by electrophoretic light scattering were negative charges and PSNs were spherical in shape according to scanning electron microscope. It was found that when PSNs were treated with LL, the PSNs were internalized into LL through nanoparticle size-, energy- and glucose transporter-dependent mechanisms. The internalization was confirmed by confocal laser scanning microscopy and fluorescence-activated cell sorting. Nisin was isolated and identified by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Also, more nisin was produced from PSNs-treated LL than untreated- or starch-treated LL. Co-culture assay and agar diffusion test were performed to test the antimicrobial ability. Antimicrobial ability against Gram-negative Escherichia coli k88, Salmonella gallinarum and Gram-positive Listeria monocytogenes of LL treated with PSNs was higher than that of untreated or starch-treated group. Finally, it was found that the expression level of stress response genes dnaK, dnaJ and groES was significantly higher in PSNs-treated groups compared with starch-treated group or LL alone.

CONCLUSION

The internalization of PSNs into LL enhanced the production of nisin through mild intracellular stimulation, resulting in enhanced antimicrobial ability.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study shows the promising potential of PSNs as new prebiotics for increasing the production of nisin, thus demonstrating a new method for the biological production of such antimicrobial peptides.

Childhood COVID-19: a multicentre retrospective study

Objectives

To investigate the clinical and epidemiological characteristics of paediatric patients with coronavirus disease-19 (COVID-19).

Methods

Paediatric patients diagnosed with COVID-19 between January 15 and March 15, 2020, from seven hospitals in Zhejiang Province, China, were collected retrospectively and analysed.

Results

Thirty-two children with COVID-19, ranging in age from 3 months to 18 years, were enrolled. Family aggregation occurred in 87.5% of infant and preschool-aged children (7/8), and also school-aged children (14/16), but in only 12.5% (1/8) of adolescents (p < 0.05, p < 0.001). Most of these patients had mild symptoms: mainly fever (20/32) followed by cough (10/32) and fatigue (4/32). The average durations of viral RNA in respiratory samples and gastrointestinal samples were 15.8 d and 28.9 d, respectively. Detox duration in faeces decreased with age: 39.8 d, 27.5 d and 20.4 d in infants and preschool children, school children, and adolescents respectively (p_{0–6, –18} <0.01, p_{0–6, –14} <0.05). Pneumonia was found in 14 children, but there was no statistical significance in the incidence of pneumonia between different age groups. Thirty patients were treated with antiviral drugs, and all patients were stable and gradually improved after admission.

Conclusions

Most children with COVID-19 had a mild process and a good prognosis. More attention should be paid to investigation of household contact history in the diagnosis of COVID-19 in young children. Viral RNA lasts longer in the gastrointestinal system than in the respiratory tract, especially in younger children.

Viral kinetics and factors associated with rapid viral clearance during lopinavir/ritonavir-based combination therapy in non-severe COVID-19 patients

OBJECTIVE

Lopinavir/ritonavir has modest antiviral activity against severe acute respiratory syndrome coronavirus 2. The aim was to investigate the viral kinetics and factors associated with viral clearance during lopinavir/ritonavir-based combination treatment in non-severe patients.

PATIENTS AND METHODS

Sixty-four patients were retrospectively enrolled. Viral RNA was detected by real-time RT-PCR assay from sputum or throat swab samples at different time points. The patterns of viral kinetics were characterized, and factors associated with rapid viral clearance, which was defined as viral RNA undetectable within two weeks, were analyzed using multivariate logistic regression analyses.

RESULTS

All patients achieved viral RNA negativity and were discharged from the hospital. Furthermore, 48 (75%) and 16 (25%) patients achieved rapid and delayed viral clearance, respectively. The lymphocyte counts of rapid viral clearance patients (1.40 [1.20-1.80] × 109/L) were higher, when compared to delayed viral clearance patients (1.00 [0.70-1.47] × 109/L) (p=0.024). The multivariate logistic analysis revealed that high lymphocyte count (≥1.3×109/L) is an independent factor associated with rapid viral clearance (OR=7.62, 95% CI=1.15-50.34, p=0.035).

CONCLUSIONS

The viral shedding exhibited different patterns during treatment. Immune insufficiency is responsible for the delayed viral clearance, suggesting that an immunomodulator should be considered to promote viral clearance in patients with low lymphocyte counts.

Correlation between MRAS gene polymorphism and atherosclerosis

OBJECTIVE

The aim of this study was to explore the correlation between muscle RAS oncogene homolog (MRAS) gene polymorphism and the onset risk of atherosclerosis (AS).

PATIENTS AND METHODS

A total of 135 AS patients diagnosed and treated in our hospital from November 2017 to October 2018 were randomly enrolled in the observation group. Meanwhile, 150 healthy adults were selected as control group. Venous blood was withdrawn from all the subjects, and DNAs were extracted. MRAS gene loci rs9818870 and rs3755751 were analyzed by the multiplex SNaPshot method, and their correlations with the onset risk of AS were explored.

RESULTS

No statistically significant differences in the frequencies at gene loci were observed between the two groups (p>0.05). Subjects with genotype TT at rs9818870 exhibited significantly higher risk of AS (p=0.041<0.05). The recessive model of rs9818870 (GG + AG/AA) in AS patients with coronary heart disease was correlated with AS (p=0.048<0.05). Similarly, the dominant model of rs3755751 (TT/TC+CC) in those with hypertension was associated with AS (p=0.027<0.05).

CONCLUSIONS

MRAS gene is correlated with the onset of AS to a certain degree.

Clinical efficacy of lopinavir/ritonavir in the treatment of Coronavirus disease 2019

OBJECTIVE

The Coronavirus disease 2019 (COVID-19) which outbroke in December 2019 is highly contagious with a low cure rate. In view of this, there is an urgent need to find a more appropriate therapeutic scheme against COVID-19. The study aimed to investigate whether lopinavir/ritonavir (LPV/r) in combination with other pneumonia-associated adjuvant drugs has a better therapeutic effect on COVID-19.

PATIENTS AND METHODS

Totally 47 patients with COVID-19 infection who were admitted to Rui'an People's Hospital between January 22 and January 29, 2020 were collected. The patients were divided into the test group and the control group according to whether they had been treated with LPV/r or not during hospitalization. Patients in the test group were treated with LPV/r combined with adjuvant medicine, while those in the control group were just treated with adjuvant medicine. The changes of body temperature, blood routine and blood biochemistry between the two groups were observed and compared.

RESULTS

Both groups achieved good therapeutic effect with the body temperature of patients decreased gradually from admission to the 10th day of treatment. But the body temperature of patients in the test group decreased faster than that of the control group. Blood routine indexes showed that compared with the control group, the abnormal proportion of white blood cells, lymphocytes and C-reactive protein of the test group could be reduced to some extent. Blood biochemical indexes exhibited that the proportion of patients with abnormal alanine aminotransferase and aspartate aminotransferase in the test group were lower than the control group. The number of days for nCoV-RNA turning negative after treatment was significantly decreased in the test group than that in the control group.

CONCLUSIONS

Compared with the treatment of pneumonia-associated adjuvant drugs alone, the combination treatment with LPV/r and adjuvant drugs has a more evident therapeutic effect in lowering the body temperature and restoring normal physiological mechanisms with no evident toxic and side effects. In view of these conclusions, we suggested that the use of LPV/r combined with pneumonia-associated adjuvant drugs in the clinical treatment for patients with COVID-19 should be promoted.

Mesoporous TiO2/carbon catalytic ozonation for degradation of p-chloronitrobenzene

In this study, a mesoporous TiO₂/carbon catalyst (TiO₂/C) was prepared by a facile impregnation-carbonization approach to catalyze ozonation of p-chloronitrobenzene (p-CNB). The catalyst was well characterized and the catalytic efficiency under various conditions was systematically evaluated. TiO₂/C has a disordered mesostructure with a high specific surface area. 92.8% of p-CNB (2 μmol/L) can be degraded within 20 min in the TiO₂/C/O₃ system in the presence of 1 mg/L O₃, 100 mg/L catalyst, at pH = 5. Based on the evaluation of the effect of basic parameters, it could be deduced that the removal of p-CNB relied on the synthetic effect of catalysis by TiO₂/C and the autocatalytic induction of p-CNB. The removal efficiency of p-CNB, the structure change and the leaching of Ti ions were also evaluated in five cycles, indicating TiO₂/C is stable and recyclable for catalytic ozonation in water treatment.

Crystallization-induced refractive index modulation on sapphire-derived fiber for ultrahigh temperature sensing

We have demonstrated crystallization-induced refractive index (RI) modulation on sapphire-derived fiber (SDF) showing superheat resistance and developed the SDF based Fabry-Perot interferometers (FPIs) for ultrahigh temperature sensing. The SDF is a special fiber with high concentration of alumina to silica in the fiber core region. Reheating and cooling the SDF by arc discharge generates mullite particles in the core region, which achieves RI modulation up to ~0.015. Such crystallized region in the SDF is explored as mirrors for FPI, showing a good linear response to temperature with sensitivity of ~13.2 pm/°C. Benefiting from superheat resistance of the crystallized SDF being mirrors, the developed SDF-FPI sensor is capable to withstand high temperature up to 1600°C, which is the highest working temperature for amorphous fiber. Moreover, the SDF-FPI sensor exhibits 6-hour stability at 1200°C. The crystallized SDF-FPIs with compactness, wide temperature working range, high sensitivity, and robustness show great potential application in harsh environment such as turbine engines, power plants, petrochemical, gas industry, etc.

Ameliorating Effects of Leaf Water Extract of Three Aromatic Plant Species on Ozone-Polluted Snap Bean (Phaseolus vulgaris L. 'Jiangjunyoudou')

Ozone (O₃) is one of the major pollutants in near-surface air. In order to protect sensitive plants from O₃ pollution, many kinds of protectants including synthetic ones, were assessed in previous studies. Although they have certain protective effects, some of them are not environment-friendly. In the present study, leaf water extracts of aromatic plants [Plectranthus hadiensis var. tomentosus (PHT), Pelargonium hortorum (PHB), Tagetes patula (TP)] were compared for mitigating the damages caused by O₃ (150 ppb for 3 days, 8 h day^-1) on snap bean (Phaseolus vulgaris 'Jiangjunyoudou'). Our results showed that O₃ fumigation impaired plasma membrane, decreased chlorophyll content, increased contents of malondialdehyde and superoxide anion, inhibited photosynthesis, and caused visible injury. Leaf water extracts of PHT, PHB or TP ameliorated the negative effects of O₃. Among them, extract of PHT showed the greatest potential to alleviate the O₃-caused injury, followed by PHB and TP.

The prevalence of psychological comorbidity in people with vitiligo: a systematic review and meta-analysis

BACKGROUND

Vitiligo is a chronic disorder causing skin depigmentation with global prevalence varying from 0·2% to 1·8%. U.K. guidelines recommend assessment of psychological state during clinical evaluation of vitiligo. However, the prevalence of psychological comorbidity in people with vitiligo has not been described.

OBJECTIVES

To establish the prevalence of psychological symptoms or disorders in people with vitiligo and describe the outcome measures used.

METHODS

We performed a comprehensive search of MEDLINE, Embase, CINAHL and PsycINFO to identify observational studies assessing the prevalence of psychological symptoms or disorders (December 2016). DerSimonian and Lard random-effects models were used to estimate the overall pooled prevalence.

RESULTS

We identified 29 studies with 2530 people with vitiligo. Most studies included a measure of either depression (n = 25) or anxiety (n = 13). The commonest tools were the Hospital Anxiety and Depression Scale and the Centre for Epidemiology Studies Depression Scale. Ten studies provided information on 13 other psychological outcomes. Pooled prevalence using depression-specific and anxiety-specific questionnaires was 0·29 [95% confidence interval (CI) 0·21-0·38] and 0·33 (95% CI 0·18-0·49), respectively. Prevalence was lower for clinically diagnosed depression (0·21, 95% CI 0·15-0·28) and anxiety (0·15, 95% CI 0·06-0·24). When nonspecific tools were used the prevalence remained similar for depression (0·27, 95% CI 0·08-0·46) but increased for anxiety (0·46, 95% CI 0·39-0·52). High heterogeneity was observed.

CONCLUSIONS

A range of psychological outcomes are common in people with vitiligo. The prevalence of anxiety was influenced by type of screening tool, suggesting the need for validation of psychological outcome screening tools in the field of dermatology.

Treatment results of adjuvant pelvic radiotherapy after radical hysterectomy for low-risk Stage IB1-IIA cervical cancer

Objective

The aim of the present retrospective analysis was to determine the effectiveness of pelvic radiotherapy (RT) as postoperative adjuvant therapy for low-risk cervical cancer.

Methods

Between June 2003 and April 2011, the clinical data of 225 International Federation of Gynecology and Obstetrics (FIGO) Stage IB1-IIA cervical cancer patients with low-risk factors were retrospectively reviewed, to analyze the relationship between adjuvant pelvic RT after radical hysterectomy and tumor recurrence or the patients' survival.

Results

The 5-year overall survival (OS) of 225 patients was 91.2% and 5-year disease-free survival (DFS) was 84.5%. The 5-year DFS and local regional disease-free survival was significantly better for patients in the RT group compared with that in the non-RT group (5-year DFS, 91.2% vs. 77.1%, P = 0.006; 5-year local regional disease-free survival 94.6% vs. 79.0%, P = 0.001). There were no statistically significant differences in the 5-year OS (92.9% vs. 89.4%, P = 0.371) and distant metastasis-free survival (96.4% vs. 96.5%, P = 0.887) between the two groups. Grade 3-4 treatment-related acute and late toxicities were not significantly different between the two groups. Subgroup analysis shows the 5-year DFS of RT alone, chemotherapy (CT) alone, non-RT/CT, RT and CT was, respectively, 90.5%, 62.9%, 81.4%, 92.5% separately (P = 0.002). The 5-year OS was not significantly different (91.6% vs. 78.2% vs. 92.9% vs. 96.9%, P = 0.887) between the four groups. Performing univariate analysis, postoperative CT was the only significant risk factor for DFS.

Conclusions

Our results indicate that postoperative adjuvant pelvic RT has a tendency to improve DFS especially local regional disease-free survival for FIGO Stage IB1-IIA cervical cancer patients with low-risk factors, without increased Grade 3-4 treatment-related acute and late toxicities, but non-standard CT is harmful to the prognosis (DFS) of these patients.

[Value of non-invasive models of liver fibrosis in judgment of treatment timing in chronic hepatitis B patients with ALT < 2×upper limit of normal]

Objective: To investigate the value of non-invasive liver fibrosis models, FIB-4, S index, aspartate aminotransferase to platelet ratio index(APRI), globulin-platelet(GP)model, aspartate aminotransferase/platelet/gamma-glutamyl transpeptidase/alpha-fetoprotein(APGA), and platelet/age/phosphatase/alpha-fetoprotein/aspartate aminotransferase(PAPAS), in the diagnosis of marked liver fibrosis in chronic hepatitis B(CHB)patients with ALT < 2×upper limit of normal(ULN), as well as treatment timing for this population. Methods: A total of 389 CHB patients with ALT < 2×ULN who were admitted to Beijing Ditan Hospital and whose treatment timing was difficult to judge were enrolled. Transdermal liver biopsy was performed to obtain pathological results, and routine serological tests were performed, including routine blood test, serum biochemical parameters, hepatitis B virus(HBV)markers, and HBV DNA. According to liver pathology, the patients were divided into non-marked liver fibrosis group(S < 2)with 324 patients and marked liver fibrosis group(S≥2)with 65 patients. The non-invasive models for predicting liver fibrosis was established with reference to original articles. SPSS 19.0 software was used for statistical analysis, and the receiver operating characteristic(ROC)curve was used to compare the value of different non-invasive models in predicting marked liver fibrosis in this population. Results: All the non-invasive models had a certain diagnostic value for liver fibrosis degree in these patients, and the areas under the ROC curve for APRI, FIB-4, APGA, S index, PAPAS, and GP model were 0.718, 0.691, 0.758, 0.729, 0.673, and 0.691, respectively. APGA had the largest area under the ROC curve(0.758, 95% CI 0.673-0.844), and gamma-glutamyl transpeptidase was significantly positively correlated with liver fibrosis degree. Conclusion: The non-invasive models of liver fibrosis can identify marked liver fibrosis in CHB patients with ALT < 2×ULN in whom it is difficult to judge treatment timing and help to determine treatment timing for them. APGA model has the highest value and can reduce the need for liver biopsy to the certain degree.

Dendritic Cells from Rheumatoid Arthritis Patient Peripheral Blood Induce Th17 Cell Differentiation via miR-363/Integrin αv/TGF-β Axis

Dendritic cells (DCs) are critical regulators of immune responses. This study was to observe the effect of DCs from peripheral blood on the differentiation of Th17 in patients with rheumatoid arthritis (RA). Peripheral blood samples were collected from 30 patients with RA and 20 healthy controls, respectively. Flow cytometry results showed that in contrast to Treg cells, the proportion of Th17 cells in T cells and the Th17/Treg ratio were both increased in patients with RA. The RT-PCR results showed that Foxp3、ROR γt and miR-363 expression in PBMC of patients with RA were reduced, but the ITGAV expression was increased, which was negatively related to miR-363 expression. IL-17, TGF-β and IL-6 levels detected by ELISA were increased in peripheral blood serum of patients with RA. Moreover, we noted that the CD11C⁺ αν⁺ /CD11C⁺ DCs ratio was obvious increased in patients with RA and has positive correlation to the Th17/Treg ratio. In cocultured system, Th17 cell differentiation was significantly inhibited in the presence of ITGF-β suggesting that Th17 cell differentiation was controlled by active TGF-β (aTGF-β). After DCs transfecting with miR-363 mimics and cocultured with T cells, Th17 cell number, IL-17 level and ROR-γt expression were significantly reduced in the presence of latent TGF-β (ITGF-β). In addition, the integrin αv protein expression was both reduced in the presence of aTGF-β or ITGF-β. These data demonstrated that DCs induced Th17 cell differentiation through miR-363/Integrin αv/TGF-β pathway in patients with RA.