[Clinical research of multisystem inflammatory syndrome in children].

Objective: To analyze the clinical characteristics of children with multisystem inflammatory syndrome (MIS-C) associated with SARS-CoV-2 in China, and to improve the understanding of MIS-C among pediatricians. Methods: Case series study.Collect the clinical characteristics, auxiliary examinations, treatment decisions, and prognosis of 64 patients with MIS-C from 9 hospitals in China from December 2022 to June 2023. Results: Among the 64 MIS-C patients, 36 were boys and 28 were girls, with an onset age being 2.8 (0.3, 14.0) years. All patients suffered from fever, elevated inflammatory indicators, and multiple system involvement. Forty-three patients (67%) were involved in more than 3 systems simultaneously, including skin mucosa 60 cases (94%), blood system 52 cases (89%), circulatory system 54 cases (84%), digestive system 48 cases (75%), and nervous system 24 cases (37%). Common mucocutaneous lesions included rash 54 cases (84%) and conjunctival congestion and (or) lip flushing 45 cases (70%). Hematological abnormalities consisted of coagulation dysfunction 48 cases (75%), thrombocytopenia 9 cases (14%), and lymphopenia 8 cases (13%). Cardiovascular lesions mainly affected cardiac function, of which 11 patients (17%) were accompanied by hypotension or shock, and 7 patients (12%) had coronary artery dilatation.Thirty-six patients (56%) had gastrointestinal symptoms, 23 patients (36%) had neurological symptoms. Forty-five patients (70%) received the initial treatment of intravenous immunoglobulin in combination with glucocorticoids, 5 patients (8%) received the methylprednisolone pulse therapy and 2 patients (3%) treated with biological agents, 7 patients with coronary artery dilation all returned to normal within 6 months. Conclusions: MIS-C patients are mainly characterized by fever, high inflammatory response, and multiple organ damage. The preferred initial treatment is intravenous immunoglobulin combined with glucocorticoids. All patients have a good prognosis.

[The association study of WWP2 gene polymorphisms with delayed encephalopathy after acute carbon monoxide poisoning].

Objective: To investigate the association of WWP2 single nucleotide polymorphism (rs3790088, rs4247109) with delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) , and explore the influences of DEACMP genetic predisposition. Methods: From November 2006 to December 2017, 235 DEACMP cases and 429 acute carbon monoxide poisoning (ACMP) cases were selected. All ACMP patients were followed up for more than 90 days without DEACMP. The DNA in all blood samples were extracted with the blood Genome DNA Extraction Kit. The method of Sequenom Mass Array SNP technique was used to detect the genotype and allele of WWP2. All DEACMP patients were assessed every 3 days after hospitalization by the Hasegawa Dementia Scale (HDS) and Activity of Daily Living Scale (ADL) . The distribution of genotypes in conformty with Hardy-Weinderg law was analyzed by goodness-of-fit χ(2) test, and χ(2) test was used for association analysis. Results: For rs3790088, there were 226 DEACMP cases and 414 ACMP cases. For rs4247109, there were 234 DEACMP cases and 428 ACMP cases. For rs3790088 and rs4247109 in WWP2 gene: there were not significant differences in the gene genotype distribution and allele frequency of both DEACMP group and ACMP group (P>0.05) . According to gender, there were not significant differences in WWP2 gene genotype distribution and allele frequency between two female groups and two male groups (P>0.05) . After analysis by genetic model, the genotype distributions in both DEACMP group and ACMP group were not significantly differences in three genetic models (codominant genetic model, recessive genetic model and dominant genetic model, P>0.05) . Conclusion: It has not confirmed the genetic correlation between the two gene single nucleotide polymorphisms (rs3790088, rs4247109) of WWP2 gene and the incidence of DEACMP.

Improved RANKL production by memory B cells: A way for B cells promote alveolar bone destruction during periodontitis.

Periodontitis is a bacteria-induced disease that always clinically defined as loss of attachment, periodontal pocket and bone loss. Its mechanisms were considered to be complicated, involving an imbalance of the formation and resorption of bone. We sought to determine the function and mechanisms of the effects of B cells on osteoclastogenesis. We purified memory B cells from periodontitis or healthy animals and culture them. Receptor activator of nuclear factor kappa-B ligand (RANKL), expressed by gingival memory B cells, was detected by flow cytometry, enzyme-linked immunosorbent assay and real-time quantitative polymerase chain reaction (RT-qPCR). To discover any direct effects on osteoclastogenesis, gingival memory B cells were co-cultured with bone marrow mononuclear cells, osteoclast number and genes related to osteoclast differentiation were examined. In further investigations, an adoptive transfer experiment of memory B cells was designed, and pathologic indexes and expression of associated cytokines in different tissues were also investigated. We find that memory B cells from inflammatory gingiva produced more RANKL. Notably, such B cells promote osteoclastogenesis. In an adoptive transfer experiment, memory B cells enhanced alveolar bone loss and osteoclast formation. We also find a higher expression of RANKL, TNF-α, IL-1ß and IL-17A in gingival crevicular fluid, gingiva and cervical lymph nodes of adoptive transfer group. Our findings highlighted the considerable importance of B cells in alveolar bone homeostasis independent of antibody production during periodontitis.

CD8+ Foxp3+ T Cells Affect Alveolar Bone Homeostasis via Modulating Tregs/Th17 During Induced Periodontitis: an Adoptive Transfer Experiment.

Periodontitis is a dysbiotic bacteria-mediated disease characterized by periodontal inflammations and alveolar bone damage. Its mechanisms were complicated, involving an inflammation-mediated bone destruction. We sought to determine roles and rules that CD8+ regulatory T cells (CD8+ Tregs) affect alveolar bone homeostasis during periodontitis. Presence of CD8+ Tregs in the gingiva, cervical lymph nodes (CLNs), and spleens of healthy or periodontitis animals was analyzed. CD8+ regulatory T cells from periodontitis animals were sorted by magnetic-activated cell sorting and fluorescent-activated cell sorting technique, subsequently injected into recipient animals to set adoptive transfer model. We induced experimental periodontitis on transfer models and equal number healthy animals. Four weeks later, their alveolar bone loss and osteoclast coverage length were measured. We also detected CD8+ Tregs, CD4+ T cell, CD4+ Tregs, Th17 cell, and IL-1ß, IL-6, IL-10, IL-17A, RANKL, TGF-ß expression in the gingiva, CLNs, and spleen to illustrate possible working mechanism of CD8+ regulatory T cells. Periodontitis does not induce significant change on proportion or amount of CD8+ Tregs. Adoptive transfer of CD8+ Tregs reduces alveolar bone destruction and osteoclast formation. In addition, experimental periodontitis increases percentage of Th17 cells and decreases CD4+ Tregs in the gingiva and CLNs. More IL-1ß, IL-6, IL-17A, and RANKL, and less IL-10 and TGF-ß are also detected in the gingiva and CLNs from animals with periodontitis than the one from healthy animals. Adoptive transfer of CD8+ regulatory T cells remedies all above pathological change effectively. We did not find any significant difference in spleen, regardless group and detected items. Outcomes of present study clarify function that CD8+ regulatory T cells affect alveolar bone homeostasis, and disclose its possible working mechanisms. CD8+ regulatory T cells protect alveolar bone via reducing osteoclastogenesis and modulating local immune response.

14-3-3 eta depletion sensitizes glioblastoma cells to irradiation due to enhanced mitotic cell death.

14-3-3 proteins have important roles in several cellular processes such as cell cycle progression, the DNA-damage checkpoint and apoptosis. We have shown previously that depleting 14-3-3η, a 14-3-3 isoform, enhances mitotic cell death, and that combining it with microtubule agents is more effective for anticancer therapeutics. In this study, we investigated whether depleting 14-3-3η can be combined with radiotherapy to enhance its therapeutic efficacy. We found that depleting 14-3-3η resulted in a synergistic radiosensitizing effect when combined with radiotherapy in several glioblastoma cell lines, where its specific expression and correlation of its expression level with malignancy have been reported. The radiosensitizing effect was associated with enhanced mitotic cell death by 14-3-3η depletion but not with mitotic catastrophe, which is one of the major cell death mechanisms observed in response to irradiation of most solid tumors. These results suggest that 14-3-3η may be a therapeutic target to overcome radioresistance in glioblastoma.

Cbl-independent degradation of Met: ways to avoid agonism of bivalent Met-targeting antibody.

The Met receptor tyrosine kinase, found to be constitutively activated in many tumors, has become a leading target for cancer therapy. Disruptions in Met downregulation have been associated with aggressive tumor progression with several therapeutic strategies addressing this aspect of Met biology. Castias B-lineage lymphoma (Cbl) E3 ligase-mediated degradation, which attenuates Met signaling via ligand-dependent Met internalization, is a major negative regulator of Met expression. It is believed that one of the mechanisms by which the therapeutic anti-Met antibodies induce cancer cell death in Met overexpressing tumors is via internalization and subsequent degradation of Met from the cell surface. However, a previously reported Met-targeting antibody demonstrated intrinsic agonistic activity while being capable of inducing Cbl-mediated degradation of Met, suggesting that Cbl-mediated degradation requires receptor activation and impedes therapeutic application. We have developed a potent and selective bivalent Met-targeting antibody (SAIT301) that invokes Met degradation using an alternative regulator LRIG1. In this report, we demonstrate that LRIG1 mediates degradation of Met by SAIT301 and this degradation does not require Met activation. Furthermore, SAIT301 was able to downregulate Met and dramatically inhibit growth of tumors with low or no Cbl expression, as well as tumors with Met exon 14 deletion that prevents Met binding to Cbl. In summary, we demonstrate the enhanced therapeutic potential of a novel tumor-inhibiting anti-Met antibody, SAIT301, which utilizes a Cbl-independent, LRIG1-mediated Met degradation pathway and thereby avoids the agonism that limits the effectiveness of previously reported anti-Met antibodies.

Roles of 14-3-3η in mitotic progression and its potential use as a therapeutic target for cancers.

14-3-3 proteins are involved in several cellular processes, including the G1/S and G2/M cell cycle transitions. However, their roles during mitosis are not well understood. Here, we showed that depletion of 14-3-3η, a 14-3-3 protein isoform, enhanced mitotic cell death, resulting in sensitization to microtubule inhibitors and inhibition of aneuploidy formation. The enhanced mitotic cell death by depletion of 14-3-3η appeared to be both caspase-dependent and independent. Furthermore, enhanced mitotic cell death and a reduction in aneuploidy following 14-3-3η depletion were independent of the mitotic checkpoint, which is thought to be the primary signaling event in the regulation of the cell death induced by microtubule inhibitors. When 14-3-3η depletion was combined with microtubule inhibitors in HCT116 and U87MG cells, it sensitized both cancer cell lines to microtubule inhibitors. These results collectively suggest that 14-3-3η may be required for mitotic progression and may be considered as a novel anti-cancer strategy in combination with microtubule inhibitors.

First Report of Bacterial Black Spot Disease in Watermelon Caused by Acidovorax valerianellae in Korea.

Watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai), an important member of the Cucurbitaceae family, is cultivated on 21,000 ha that produces 850,000 t in Korea. In April 2011, we received grafted watermelon with necrotic leaf spots from a commercial watermelon grower in Andong, Korea. Black spots were observed on cotyledons of the plants in seedbeds, and approximately 9% of watermelon plants were infected with the disease. Initial symptoms on the seedling were black, greasy spots sometimes surrounded by a halo of discoloration. Younger leaves usually showed symptoms later than cotyledons. Bacteria isolated from the infected plants were gram-negative, motile, straight rods with a single flagellum and 0.84 to 0.89 µm wide and 1.54 to 1.69 µm long. They formed rough colonies with a white-cream color after 48 h of incubation on Luria-Bertani (LB) agar at 28°C. Colonies of isolates were nonfluorescent, smooth, and white on King's medium B. On YBGA (7 g of yeast extract, 7 g of bactopeptone, 7 g of glucose, 15 g of agar, 1,000 ml of distilled water; pH 7.2) colonies are circular, raised with an entire margin, and white to cream. Pathogenicity tests were conducted with potted, greenhouse-grown watermelon plants. Bacterial colonies grown on LB medium for 48 h at 28°C were suspended in sterile distilled water, and the suspension (1.0 × 108 CFU/ml) was infiltrated into mesophyll of watermelon leaves with a syringe as previously described (2). Inoculated plants were maintained at 28°C and 90% relative humidity in a growth chamber with a daily 12-h photoperiod of fluorescent light. Five plants were used for inoculation. Sterilized distilled water was used as a control. The bacterial isolates induced necrosis in the infiltrated area within 3 to 5 days. Typical water-soaked spots appeared after 3 days of incubation and became gray to black after 6 days. The bacterium was successfully reisolated from the diseased lesions, thus completing Koch's postulates. A cell suspension (50 µl of 1 × 106 CFU/ml) was infiltrated with a syringe into the intercellular spaces of tobacco leaves to determine the hypersensitive reaction (HR). A typical HR developed 20 h after leaf infiltration. The 16S rDNA region of the isolates, amplified by using universal PCR primers, shared 99% sequence identity with an Acidovorax valerianellae strain (GenBank Accession No. AJ431731) (1). The resulting sequences of 1,424 bp were deposited in GenBank (Accession No. JN983471). The isolates we obtained in this study clustered with A. valerianellae on a phylogenetic tree generated by the neighbor-joining method implemented in MEGA Version 4.1. In the Biolog Microbial Identification System, Version 4.2 (Biolog Inc., Hayward, CA), all isolates were 63 to 77% similar with a match probability of 100% to A. konjaci. Fatty acid composition analysis of isolates based on the MIDI Library version TSBA 5.0 and Library Generation system software version 5.0 showed that the isolates were 52 and 72% similar to an Acidovorax sp., respectively. To our knowledge, this is the first report of bacterial black spot disease in watermelon caused by A. valerianellae in Korea. A. valerianellae is a causal agent of bacterial black spot in corn salad and is transmitted by inoculated seeds (3). Further studies are required to determine whether it is seed transmitted in watermelon. References: (1) L. Gardan et al. Int. J. Syst. Evol. Microbiol. 53:795, 2003. (2) C. Grondeau et al. Plant Pathol. 56:302, 2007. (3) C. Grondeau et al. Plant Pathol. 58:846, 2009.

In vitro and in vivo study of lens refilling with poloxamer hydrogel.

AIM: To evaluate the compatibility of poloxamer hydrogel as a material for an injectable intraocular lens, in vivo and in vitro. METHODS: The appropriate concentration of poloxamer hydrogel was determined for injection by examining the transparency and gelling temperature of this material, assessing the lens capsule refilling technique, and studying the postoperative findings in a rabbit model. RESULTS: Poloxamer hydrogel showed excellent transparency and 25% was identified as an appropriate concentration for the lens refilling material. The authors developed a technique for injecting the material in vivo and obtained excellent short term results. CONCLUSIONS: Poloxamer hydrogel was identified as an appropriate material for direct lens refilling, and the developed injection technique produced excellent short term results.

Effect of immune RNA on NK activity of infants born to mothers with cytomegalovirus infection.

The effect of specific immune RNA (i-RNA) on the activity of natural killer (NK) cells in the peripheral blood of 27 newborn infants was studied by lactic dehydrogenase (LDH) release assay. Peripheral blood mononuclear cells (PBMC) were used as effector cells with K-562 tumour cells as target cells. The results showed that in the therapeutic group (n = 17) the average activity of NK cells after therapy (24.13 +/- 4.62%) was 13.67 +/- 5.79% higher than before therapy (10.47 +/- 3.57%). In the control group (n = 10) these were only 10.78 +/- 3.94% and 11.58 +/- 3.37%, the difference was not statistically significant (P > 0.05). However, NK activity in the therapeutic group and control group was markedly different (P < 0.01). The data indicate that specific i-RNA can enhance the activity of NK cells in the peripheral blood of newborn infants. Therefore, we believe that specific i-RNA may play an important role in defence against CMV infection. The mechanism of i-RNA augmenting NK cellular activity is also discussed.

Rapid serodiagnosis of human mycobacteriosis by ELISA using cord factor (trehalose-6,6'-dimycolate) purified from Mycobacterium tuberculosis as antigen.

IgG antibodies against purified cord factor (trehalose-6,6'-dimycolate, TDM) in sera of 99 patients infected with mycobacteria (42 patients with tuberculosis excreting tubercle bacilli in the sputum, 11 patients with non-tuberculous mycobacteriosis excreting acid-fast bacilli in the sputum, and 46 patients without bacilli in the sputum but diagnosed as having pulmonary tuberculosis by chest X-ray films and physical examination), five patients with lung cancer, and 100 healthy controls which included subjects positive and negative for the tuberculin test were tested by the ELISA with TDM purified from Mycobacterium tuberculosis H37Rv as the antigen. Of the 99 cases of mycobacteriosis, 83 patients (83.8%) had positive results (48 samples from 53 patients, or 90.5%, with bacilli in the sputum, and 35 samples from 46 patients (76%) with tuberculosis diagnosed clinically). The sera of the five patients with lung cancer and the 100 controls all gave negative results. Thus, the sensitivity and specificity were 83.8% and 100%, respectively. ELISA with TDM as the antigen is simple, reproducible, and useful for the rapid serodiagnosis of general mycobacterial infections including tuberculosis, because it does not involve the cultivation of bacteria.

Time-dependent recovery from electroconvulsive shock-induced amnesia.

To examine time-dependent recovery from ECS-induced amnesia, 44 hooded rats were trained to leverpress for food. On treatment day the first leverpress was followed by footshock and ECS or sham ECS (SECS). Animals in both treatment conditions then experienced a 10-min extinction session either 1 or 3 days following treatment. For both the 1-day and 3-day delay ECS groups, the latencies to the first response during extinction were lower than the latencies of the corresponding SECS groups. When extinction followed treatment by 1 day, the ECS rats also made more responses during the test than the SECS rats; however, when tested 3 days after treatment, the ECS and SECS groups did not differ on extinction response rate. In this operant setting, therefore, time-dependent recovery from amnesia can be demonstrated with response rate as the amnesia measure. In addition, since both groups of SECS animals exhibited significant interrelationships of measures following treatment and the same measures were not associated in the ECS groups, it was hypothesized that the proactive effects of ECS include a reduction in the stability of performance.