Immunomodulatory effects of Ulva-derived polysaccharides, oligosaccharides, and residues in a murine model of delayed-type hypersensitivity.

Ulva, an edible green alga, contains sulfated polysaccharides and oligosaccharides that possess immunomodulatory and anti-inflammatory properties. The objective of this study was to investigate the anti-allergic effects of Ulva-derived samples of polysaccharides (UP), oligosaccharides (UO), and residues (UR) on delayed-type hypersensitivity (DTH) in mice. Oral treatment of mice with UP, UO, and UR (250 mg/kg body weight) daily noticeably improved the DTH reaction as evidenced by attenuation of footpad swelling and cell infiltration at the allergen-challenge site. Although the Ulva samples had limited impacts on the production of serum total IgG, decreased concentrations of allergen-specific IgG and IgG2a and an increased concentration of IgG1 were observed in the treated mice. Moreover, treatment with them suppressed allergen-induced IFN-γ and TNF-α secretion and elevated IL-4 secretion. However, none of the Ulva sample treatments could modulate the production of IL-10. Concordantly, the in situ data reveal that the Ulva sample treatments suppressed IFN-γ and TNF-α expression at the allergen-injection site. These findings collectively suggest the potential of UP, UO, and UR as functional food candidates for the management of delayed-type hypersensitivity.

Promoting mental health in children and adolescents through digital technology: a systematic review and meta-analysis.

Background: The increasing prevalence of mental health issues among children and adolescents has prompted a growing number of researchers and practitioners to explore digital technology interventions, which offer convenience, diversity, and proven effectiveness in addressing such problems. However, the existing literature reveals a significant gap in comprehensive reviews that consolidate findings and discuss the potential of digital technologies in enhancing mental health. Methods: To clarify the latest research progress on digital technology to promote mental health in the past decade (2013-2023), we conducted two studies: a systematic review and meta-analysis. The systematic review is based on 59 empirical studies identified from three screening phases, with basic information, types of technologies, types of mental health issues as key points of analysis for synthesis and comparison. The meta-analysis is conducted with 10 qualified experimental studies to determine the overall effect size of digital technology interventions and possible moderating factors. Results: The results revealed that (1) there is an upward trend in relevant research, comprising mostly experimental and quasi-experimental designs; (2) the common mental health issues include depression, anxiety, bullying, lack of social emotional competence, and mental issues related to COVID-19; (3) among the various technological interventions, mobile applications (apps) have been used most frequently in the diagnosis and treatment of mental issues, followed by virtual reality, serious games, and telemedicine services; and (4) the meta-analysis results indicated that digital technology interventions have a moderate and significant effect size (g = 0.43) for promoting mental health. Conclusion: Based on these findings, this study provides guidance for future practice and research on the promotion of adolescent mental health through digital technology. Systematic review registration: https://inplasy.com/inplasy-2023-12-0004/, doi: 10.37766/inplasy2023.12.0004.

Anti-allergic effects of Ulva-derived polysaccharides, oligosaccharides and residues in a murine model of food allergy.

The medicinal benefits of green seaweed Ulva have been documented in traditional Chinese medicine literatures. Sulfated polysaccharides found in Ulva are recognized as the primary bioactive compounds, known for their immunomodulatory and anti-inflammatory properties. Despite this knowledge, the available information regarding anti-allergic activities of Ulva remains limited. The objective of this study was to prepare and characterize Ulva-derived polysaccharides (UP), oligosaccharides (UO), and residues (UR), followed by assessing their potential in improving allergic enteritis and gut microbiota in a murine model of ovalbumin (OVA)-induced food allergy. The immunomodulatory activities of UP, UO, and UR were evaluated by measuring the expression of serum antibodies, splenic cytokines and duodenal transcript factors of T cell subsets. The impact of UP, UO, and UR on enteric microbiota was explored by 16S rRNA gene sequencing analysis of fresh fecal samples from treated mice. Oral treatment of UP, UO, and UR noticeably attenuated allergic diarrhea and enteritis. Additionally, Ulva samples treatment decreased serum levels of IgG1 and OVA-specific IgE while increased the level of OVA-specific IgG. Enhanced production of IFN-γ and reduced production of IL-4 and IL-10 by splenocytes were observed in the treated mice. In parallel, Ulva samples treatment led to a decreased number of GATA3+ cells and an increased number of T-bet+ cells in the duodenum. However, the population of Foxp3+ cells was not significantly altered. Moreover, treatment of Ulva samples improved enteric dysbiosis evidenced by an increased abundance of Lactobacillus murinus, L. johnsonii, and L. reuteri, and a decreased abundance of Kineothrix alysoides, Lacrimispora saccharolytica, L. aerotolerans, and Erysipelotrichaceae in feces. In conclusion, UP, UO, and UR, which could modulate the Th1/Th2 immune balance, alleviate allergic enteritis and improve enteric dysbiosis in varying degrees, are potential to be developed into therapeutic agents for food allergy.

Prepandemic relationship satisfaction is related to postpandemic COVID-19 anxiety: A four-wave study in China.

The COVID-19 pandemic has had lasting impacts on people's interpersonal relationship and mental health. Using four-wave data in China (N = 222, 54.50% female, Mage = 31.53, SD = 8.17), the current study examined whether prepandemic relationship satisfaction was related to postpandemic COVID-19 anxiety through midpandemic perceived social support and/or gratitude. The results showed that people's COVID-19 anxiety decreased from the peak to the trough stage of the pandemic; perceived social support increased markedly from prepandemic to the peak and remained stable subsequently, while relationship satisfaction remained unchanged throughout. Further, it was midpandemic perceived social support, not gratitude, that mediated the association between prepandemic relationship satisfaction and postpandemic COVID-19 anxiety, indicating that perceived social support played a crucial role in this process. Finally, it is suggested that perceived social support should be distinguished from gratitude as two different components of social interactions.

SARS-CoV-2 Antibodies and Associated Factors at Different Hospitalization Time Points in 192 COVID-19 Cases.

BACKGROUND: We launched a retrospective analysis of SARS-CoV-2 antibodies in 192 patients with COVID-19, aiming to depict the kinetic profile of SARS-CoV-2 antibodies and explore the factors related to SARS-CoV-2 antibody expression. METHODS: Data on 192 confirmed patients with COVID-19 between January and February 2020 was collected from the designated hospital that received patients with COVID-19 in Guangzhou, China. Moreover, a cohort of 130 suspected patients with COVID-19 and 209 healthy people were also enrolled in this study. IgM and IgG antibodies to SARS-CoV-2 were detected by the chemiluminescence immunoassay kits in different groups. RESULTS: A total of 192 COVID-19 cases were analyzed, of which had 81.8% anti-SARS-CoV-2 IgM detected and 93.2% anti-SARS-CoV-2 IgG detected, respectively, at the time of sampling. The kinetics of anti-SARS-CoV-2 IgM and IgG showed that, the confirmed cases had anti-SARS-CoV-2 IgM seroconversion occurred 5-10 days after the onset of the symptoms, and then IgM rose rapidly to reach a peak within around 2-3 weeks, maintaining at its peak for 1 week before its decline. While they had anti-SARS-CoV-2 IgG seroconversion simultaneously or sequentially with IgM, reaching its peak within around 3 to 4 weeks and began to decline after the fifth week. Besides, correlation analysis showed that in patients with COVID-19 the level of IgM was related to gender and disease severity (P < 0.01), and the level of IgG was related to age and disease severity (P < 0.001). The univariate analysis of relevant factors indicated that the level of IgG had a weak correlation with age (r = 0.374, P < 0.01). The level of IgM in male patients was higher than that in female patients (P < 0.001). The expression level of anti-SARS-CoV-2 IgM and IgG were positively correlated with the severity of COVID-19 and the duration of the virus in the patients. CONCLUSION: The findings of this study show that anti-SARS-CoV-2 IgM and IgG can be important assisting COVID-19 diagnosis, especially in the early phase of infection. Furthermore, antibody expression in patients with COVID-19 is also correlated with disease severity, age, gender, and virus clearance or continuous replication.

Perceived Social Support Protects Lonely People Against COVID-19 Anxiety: A Three-Wave Longitudinal Study in China.

The isolation necessary to prevent the spread of the coronavirus disease 2019 (COVID-19) can give rise to anxiety, especially for lonely people who often feel upset without others' company. Although isolated from others, people can still receive support from others, which might lower their COVID-19 anxiety. To examine the relationship between loneliness, perceived social support, and anxiety, we measured 222 Chinese participants' (54.50% female, M age = 31.53, SD = 8.17) trait loneliness, chronic anxiety before the outbreak, COVID-19 anxiety at the peak and decline stages of COVID-19, and their perceived social support across the three time points. The results showed that people's perceived social support dramatically increased from the pre-pandemic to the peak COVID-19 stage, and remained stable during the decline of COVID-19 stage. In contrast, COVID-19 anxiety decreased from the peak to the decline stage. Further, perceived social support consistently moderated the relationship between loneliness with both chronic anxiety and COVID-19 anxiety. The current study provides initial evidence that perceived social support provides protection for lonely people in daily life as well as during unexpected disasters, which will contribute to finding ways to alleviate lonely people's anxiety during this global health crisis.

A Tool for Early Prediction of Severe Coronavirus Disease 2019 (COVID-19): A Multicenter Study Using the Risk Nomogram in Wuhan and Guangdong, China.

BACKGROUND: Because there is no reliable risk stratification tool for severe coronavirus disease 2019 (COVID-19) patients at admission, we aimed to construct an effective model for early identification of cases at high risk of progression to severe COVID-19. METHODS: In this retrospective multicenter study, 372 hospitalized patients with nonsevere COVID-19 were followed for > 15 days after admission. Patients who deteriorated to severe or critical COVID-19 and those who maintained a nonsevere state were assigned to the severe and nonsevere groups, respectively. Based on baseline data of the 2 groups, we constructed a risk prediction nomogram for severe COVID-19 and evaluated its performance. RESULTS: The training cohort consisted of 189 patients, and the 2 independent validation cohorts consisted of 165 and 18 patients. Among all cases, 72 (19.4%) patients developed severe COVID-19. Older age; higher serum lactate dehydrogenase, C-reactive protein, coefficient of variation of red blood cell distribution width, blood urea nitrogen, and direct bilirubin; and lower albumin were associated with severe COVID-19. We generated the nomogram for early identifying severe COVID-19 in the training cohort (area under the curve [AUC], 0.912 [95% confidence interval {CI}, .846-.978]; sensitivity 85.7%, specificity 87.6%) and the validation cohort (AUC, 0.853 [95% CI, .790-.916]; sensitivity 77.5%, specificity 78.4%). The calibration curve for probability of severe COVID-19 showed optimal agreement between prediction by nomogram and actual observation. Decision curve and clinical impact curve analyses indicated that nomogram conferred high clinical net benefit. CONCLUSIONS: Our nomogram could help clinicians with early identification of patients who will progress to severe COVID-19, which will enable better centralized management and early treatment of severe disease.

Transcriptome Analysis of Two Strains of Proteus mirabilis with Swarming Migration Deficiency Isolated from Patients with Urinary Tract Infection.

Two rare strains of Proteus mirabilis with swarming migration deficiency were isolated from urine samples of two patients with urinary tract infections and were named as G121 and G137. Migration experiments showed that P. mirabilis HI4320 had typical migration on blood agar, while G121 and G137 had significantly weakened migration ability. Results of adhesion tests showed that the adhesion ability of G121 and G137 to the bladder epithelial cell line 5637 was significantly reduced. High-throughput sequencing and alignment analysis of the transcriptomes of the three P. mirabilis strains were conducted, with P. mirabilis HI4320 as the reference strain. Reverse transcription quantitative PCR (RT-qPCR) was used to verify differentially expressed genes. Results of transcriptome analysis and RT-qPCR showed that, compared to the HI4320 strain, genes related to flagellum and fimbria formation, dicarboxylate transport, and cystathionine and anthranilate metabolism were down-regulated in G121 and G137, while genes related to iron transport, molybdenum metabolism, and metalloprotease were up-regulated, suggesting that these genes may be involved in the migration ability and epithelial cell adhesion ability of P. mirabilis. These results provide important insight to the search for virulence genes and the screening of new antibacterial targets for P. mirabilis.

[Expression of Proteus mirabilis polyphosphate kinase and preparation of its polyclonal antibodies].

OBJECTIVE: To express and purify polyphosphate kinase (PPK) from Proteus mirabilis and prepare the polyclonal antibody against PPK. METHODS: The antigenicity and hydrophobicity of PPK were analyzed using software. The N-terminal conservative sequence containing 309 amino acids was selected as the target peptide, and its corresponding gene sequence with modification based on prokaryotic cells-preferred codon was synthesized and inserted into plasmid pET28b(+). The constructed recombinant plasmid was transformed into Escherichia coli BL21 (DE3) and induced with IPTG. The expressed fusion protein was purified using Ni-affinity chromatography. The purified protein was injected along with adjuvant in rabbits to prepare the polyclonal antibodies against PPK. RESULTS AND CONCLUSION: PPK fusion protein expressed by E. coli was purified successfully using Ni-affinity chromatography. ELISA result demonstrated that the harvested rabbit anti-sera against PPK had a high titer of 1:512 000, and Western blotting showed a good specificity of the antibody, which can be used further study of the role of PPK in the pathogenesis of Proteus mirabilis infection.