[L-DEP regimen salvage therapy for refractory primary hemophagocytic lymphohistiocytosis triggered by Epstein-Barr virus infection in 4 children]

Objective: To analyze the efficacy and safety of the L-DEP regimen (asparaginase, liposome doxorubicin, etoposide and methylprednisolone) as a salvage therapy for the refractory primary hemophagocytic lymphohistocytosis triggered by Epstein-Barr virus infection (EBV-pHLH) in children. Methods: In this retrospective case study, clinical and laboratory data before and after L-DEP regimen of 4 children diagnosed with EBV-pHLH in Beijing Children's hospital between January 2016 and June 2022 were collected, and the efficacy and safety of L-DEP regimen for the treatment of EBV-pHLH were analyzed. Results: Among 4 patients, there were 3 females and 1 male with the age ranged from 0.8 to 7.0 years. Two of them showed compound heterozygous mutations of PRF1, one with a heterozygous mutation of UNC13D, one homozygous mutation of ITK. Before the L-DEP therapy, all of them had anemia and a soaring level of soluble CD25, 3 patients had neutropenia and thrombopenia, 3 patients had a high level of ferritin, 3 patients had hypofibrinogenemia and 1 patient had hypertriglyceridemia. After receiving 1 or 2 cycles of L-DEP treatment, three achieved remission, including complete remission (1 case) and partial remission (2 cases), and the other one had no remission. The levels of blood cell counts, soluble CD25, triglyceride, fibrinogen and albumin were recovered gradually in 3 patients who got remission. All four patients underwent hematopoietic stem cell transplantation (HSCT) after L-DEP regimen, and three survived. All patients had no severe chemotherapy related complications. The main side effects were bone marrow suppression, infection and pancreatitis, which recovered after appropriate treatments, apart from one who died from severe infection after urgent HSCT. Conclusion: L-DEP regimen could be served as an effective and safe salvage treatment for refractory pediatric EBV-pHLH, and also provide an opportunity for patients to receive HSCT.

[Analysis of 9 cases of drug induced hypersensitivity syndrome related hemophagocytic lymphohistiocytosis]

Objective: To analyze the clinical features,treatment and prognosis of drug induced hypersensitivity syndrome related hemophagocytic lymphohistiocytosis (DIHS-HLH). Methods: This was a retrospective case study. Clinical characteristics, laboratory results, treatment and prognosis of 9 patients diagnosed with DIHS-HLH in Beijing Children's hospital between January 2020 and December 2022 were summarized. Kaplan-Meier survival analysis was used to calculate the overall survival rate. Results: Among all 9 cases, there were 6 males and 3 females, with the age ranged from 0.8 to 3.1 years. All patients had fever, rash, hepatomegaly and multiple lymph node enlargement. Other manifestations included splenomegaly (4 cases), pulmonary imaging abnormalities (6 cases), central nervous system symptoms (3 cases), and watery diarrhea (3 cases). Most patients showed high levels of soluble-CD25 (8 cases), hepatic dysfunction (7 cases) and hyperferritinemia (7 cases). Other laboratory abnormalities included hemophagocytosis in bone marrow (5 cases), hypofibrinogenemia (3 cases) and hypertriglyceridemia (2 cases). Ascending levels of interleukin (IL) 5, IL-8 and interferon-γ (IFN-γ) were detected in more than 6 patients. All patients received high dose intravenous immunoglobulin, corticosteroid and ruxolitinib, among which 4 patients were also treated with high dose methylprednisolone, 2 patients with etoposide and 2 patients with cyclosporin A. After following up for 0.2-38.6 months, 7 patients survived, and the 1-year overall survival rate was (78±14)%. Two patients who had no response to high dose immunoglobulin, methylprednisolone 2 mg/(kg·d) and ruxolitinib died. Watery diarrhea, increased levels of IL-5 and IL-8 and decreased IgM were more frequently in patients who did not survive. Conclusions: For children with fever, rash and a suspicious medication history, when complicated with hepatomegaly, impaired liver function and high levels of IL-5 and IL-8, DIHS-HLH should be considered. Once diagnosed with DIHS-HLH, suspicious drugs should be stopped immediately, and high dose intravenous immunoglobulin, corticosteroid and ruxolitinib could be used to control disease.

[Efficacy and safety of intermediate-dose cytarabine in the treatment of children with refractory high risk Langerhans cell histiocytosis]

Objective: To analyze the efficacy, safety, and long-term prognosis of intermediate-dose cytarabine (Ara-c) regimen in the treatment of children with refractory risk organ involvement Langerhans cell histiocytosis (LCH). Methods: Clinical data of 17 children with multisystem and risk organ involvement LCH who failed the first-line therapy and were treated with intermediate-dose Ara-c (250 mg/m2, twice daily) regimen in the Hematology Center, Beijing Children's Hospital from January 2013 to December 2016 were analyzed retrospectively. In addition to the basic treatment of vindesine and dexamethasone, the patients received two regimens: regimen A: the intermediate-dose Ara-c combined with cladribine and regimen B: the intermediate-dose Ara-c alone. The efficacy, safety and prognosis of the two regimens were analyzed. Results: Among all 17 patients, there were 11 males and 6 females, with the diagnosis age of 2.1 (1.6, 2.7) years. Ten children received regimen A, all of them achieved active disease-better (AD-B) after 8 courses of induction therapy. The disease activity scores (DAS) decreased from 5.5 (3.0, 9.0) to 1.0 (0, 2.3). Seven children received regimen B, and 6 of them achieved AD-B after 8 courses of induction therapy. The DAS decreased from 4.0 (2.0, 4.0) to 1.0 (0, 2.0). The follow-up time was 6.2 (4.9,7.2) and 5.2 (3.7,5.8) years in group A and B. The 5-year overall survival rate was 100.0% in both groups, and the 5-year event free survival rate was (88.9±10.5)% and (85.7±13.2)% in group A and B. Grade 3 or 4 myelosuppression was observed in 8 patients in group A and 2 patients in group B. Conclusions: The intermediate-dose Ara-c regimen (with or without cladribine) is effective and safe for patients with refractory high-risk LCH, with a good long-term prognosis.

A receptor-binding domain-based nanoparticle vaccine elicits durable neutralizing antibody responses against SARS-CoV-2 and variants of concern

Numerous vaccines have been developed to address the current COVID-19 pandemic, but safety, cross-neutralizing efficacy, and long-term protectivity of currently approved vaccines are still important issues. In this study, we developed a subunit vaccine, ASD254, by using a nanoparticle vaccine platform to encapsulate the SARS-CoV-2 spike receptor-binding domain (RBD) protein. As compared with the aluminum-adjuvant RBD vaccine, ASD254 induced higher titers of RBD-specific antibodies and generated 10- to 30-fold more neutralizing antibodies. Mice vaccinated with ASD254 showed protective immune responses against SARS-CoV-2 challenge, with undetectable infectious viral loads and reduced typical lesions in lung. Besides, neutralizing antibodies in vaccinated mice lasted for at least one year and were effective against various SARS-CoV-2 variants of concern, including B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.617.2 (Delta), and B.1.1.529 (Omicron). Furthermore, particle size, polydispersity index, and zeta-potential of ASD254 remained stable after 8-month storage at 4°C. Thus, ASD254 is a promising nanoparticle vaccine with good immunogenicity and stability to be developed as an effective vaccine option in controlling upcoming waves of COVID-19.

Upregulation of PD-L1 by SARS-CoV-2 promotes immune evasion

Patients with severe COVID-19 often suffer from lymphopenia, which is linked to T-cell sequestration, cytokine storm, and mortality. However, it remains largely unknown how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces lymphopenia. Here, we studied the transcriptomic profile and epigenomic alterations involved in cytokine production by SARS-CoV-2-infected cells. We adopted a reverse time-order gene coexpression network approach to analyze time-series RNA-sequencing data, revealing epigenetic modifications at the late stage of viral egress. Furthermore, we identified SARS-CoV-2-activated nuclear factor-κB (NF-κB) and interferon regulatory factor 1 (IRF1) pathways contributing to viral infection and COVID-19 severity through epigenetic analysis of H3K4me3 chromatin immunoprecipitation sequencing. Cross-referencing our transcriptomic and epigenomic data sets revealed that coupling NF-κB and IRF1 pathways mediate programmed death ligand-1 (PD-L1) immunosuppressive programs. Interestingly, we observed higher PD-L1 expression in Omicron-infected cells than SARS-CoV-2 infected cells. Blocking PD-L1 at an early stage of virally-infected AAV-hACE2 mice significantly recovered lymphocyte counts and lowered inflammatory cytokine levels. Our findings indicate that targeting the SARS-CoV-2-mediated NF-κB and IRF1-PD-L1 axis may represent an alternative strategy to reduce COVID-19 severity.

[Interleukin-9 promotes the activation of hepatic stellate cells in mice infected with Schistosoma japonicum]

OBJECTIVE

To investigate the effects of interleukin-9 (IL-9) in the activation of hepatic stellate cells (HSCs) in mice infected with Schistosoma japonicum.

METHODS

Primary HSCs were isolated from mice 7 weeks post-infection with S. japonicum using the in situ liver perfusion and density gradient centrifugation, and cultured in vitro. HSCs were randomly assigned to the PBS control group and IL-9 stimulation group (stimulation with 20 ng/mL IL-9). HSCs were harvested 48 h and 72 h poststimulation, and the expression of α-smooth muscle actin (α-SMA), type I collagen (Col I) and type III collagen (Col III) was determined in HSCs using Western blotting.

RESULTS

Following stimulation with 20 ng/mL IL-9 for 48 h, the expression of α-SMA [(0.87 ± 0.02) vs. (0.69 ± 0.01); t = 17.39, P < 0.01], Col I [(0.74 ± 0.02) vs. (0.65 ± 0.01); t = 9.56, P < 0.01] and Col III [(0.94 ±0.04) vs. (0.75 ± 0.03); t = 6.15, P < 0.01] was significantly greater in HSCs in the IL-9 stimulation group than in the PBS control group. Following stimulation with 20 ng/mL IL-9 for 72 h, the expression of α-SMA was significantly greater in HSCs in the IL-9 stimulation group than in the PBS control group[(0.76 ± 0.02) vs. (0.58 ± 0.02); t = 12.52, P < 0.01]; however, there were no significant differences between the two groups in terms of Col I [(0.68 ± 0.02) vs. (0.66 ± 0.02); t = 1.15, P > 0.05] or Col III expression [(0.75 ± 0.01) vs. (0.72 ± 0.02); t = 2.22, P > 0.05].

CONCLUSIONS

IL-9 promotes the activation of HSCs in mice infected with S. japonicum.

[Efficacy and safety of modified hemophagocytic lymphohistiocytosis 04 regimen in Beijing Children's Hospital]

Objective: To evaluate the efficacy and safety of Beijing Children's Hospital (BCH) modified hemophagocytic lymphohistiocytosis (HLH) 04 regimen in the treatment of childhood HLH. Methods: A retrospective cohort study was conducted. From January 2016 to December 2017, 110 children with HLH who were treated with the modified HLH-04 regimen (replacing dexamethasone with methylprednisolone during the induction period, reducing the dose and frequency of etoposide, and not using cyclosporine except for autoimmune-related HLH) at the Hematology Oncology Center of Beijing Children's Hospital were selected as the modified group, while 102 children treated with the standard HLH-04 regimen from January 2012 to December 2015 were selected as the control group. The early remission rate, survival rate and adverse reactions of two groups were compared. Rank sum test and chi square test were used for comparison between groups. Results: The age of onset in the modified group was 1.9 (1.1, 3.5) years, with 65 males and 45 females. The age of onset in the control group was 2.0 (1.2, 4.6) years, with 47 males and 55 females. No significant difference was found in age and gender between 2 groups (both P>0.05). Except for fibrinogen (1.3 (1.0, 1.7) vs. 1.1 (0.8, 1.4) g/L, Z=-2.67, P=0.008) and natural killer cell activity (13.9 (13.4, 16.3) % vs.14.9 (12.0, 16.1) %, Z=-2.34, P=0.028), there were no statistically significant differences in etiology, disease duration, first clinical presentation, or laboratory tests between 2 groups (all P>0.05). At 2 months and 3 years, there were no statistically significant differences in overall survival between 2 groups (84.5% (93/110) vs.76.5% (78/102), 78.2% (86/110) vs. 67.6% (69/102), χ²=2.28, 3.07, P=0.131, 0.080). The first 3 weeks were the most common time for bone marrow suppression in the modified group, with a lower incidence than in the control group (47.3% (52/110) vs. 62.7% (64/102), χ²=5.11, P=0.024). The modified group had a lower rate of fungal infections than the control group (3.6% (4/110) vs. 13.7% (14/102), χ²=6.93, P=0.008). Compared with the control group, fewer children in the modified group died as a result of side effects from chemotherapy (8.0% (2/25) vs.30.3% (10/33), χ²=4.31, P=0.038). Conclusion: The BCH modified HLH-04 regimen reduced the intensity of chemotherapy, with overall efficacy no worse than the standard HLH-04 regimen, and significantly reduced the rate of chemotherapy-related myelosuppression, fungal infection and mortality.

[Ruxolitinib combined with liposomal doxorubicin, etoposide, methylprednisolone+/-PEG-asparaginase in treatment of relapsed/refractory pediatric hemophagocytic lymphohistiocytosis]

Objective: To investigate the efficacy and safety of ruxolitinib, liposomal doxorubicin, etoposide, methylprednisolone+/-PEG-asparaginase (RU-DEP+/-L) in the treatment of relapsed/refractory (R/R) pediatric hemophagocytic lymphohistiocytosis (HLH). Methods: The clinical data of R/R pediatric HLH, who accepted the RU-DEP+/-L regimen at Beijing Children's Hospital from January 2018 to December 2019 was retrospectively analyzed. Results: A total of 16 patients were included in this study, including 13 males and 3 females, aged[M(Q₁,Q₃)] 1 (1, 2) years at diagnosis. Thirteen patients were diagnosed with Epstein-Barr virus (EBV)-HLH, 2 with EBV-induced primary HLH, and 1 with unclear etiology, among which 3 patients were co-infected with CMV. After the first-line treatment, 11 patients had no response, and 5 patients relapsed after complete response. Nine patients received the RU-L-DEP regimen, and 7 patients received the RU-DEP regimen. The overall response rate and complete response of RU-DEP+/-L treatment were 10/16 and 3/16, respectively. The negative conversion rate of plasma EBV-DNA was 7/15. The median follow-up time was 35.1 (2.4, 40.7) months, and 9/16 patients were survival. The 3-year overall survival rate after RU-DEP+/-L treatment in response and accepted hematopoietic stem cell transplantation (HSCT) was higher than that without response and did not receive HSCT (P=0.048). Among the 16 patients, 9 had varying degrees of myelosuppression, and 13 had an infection. Conclusions: RU-DEP+/-L can be used as a salvage treatment in R/R pediatric HLH, which can provide a bridge to HSCT and play an important role in the control of HLH. The main adverse reactions are myelosuppression and infection, which can be tolerated.

A booster dose of Delta × Omicron hybrid mRNA vaccine produced broadly neutralizing antibody against Omicron and other SARS-CoV-2 variants

BACKGROUND

With the continuous emergence of new SARS-CoV-2 variants that feature increased transmission and immune escape, there is an urgent demand for a better vaccine design that will provide broader neutralizing efficacy.

METHODS

We report an mRNA-based vaccine using an engineered "hybrid" receptor binding domain (RBD) that contains all 16 point-mutations shown in the currently prevailing Omicron and Delta variants.

RESULTS

A booster dose of hybrid vaccine in mice previously immunized with wild-type RBD vaccine induced high titers of broadly neutralizing antibodies against all tested SARS-CoV-2 variants of concern (VOCs). In naïve mice, hybrid vaccine generated strong Omicron-specific neutralizing antibodies as well as low but significant titers against other VOCs. Hybrid vaccine also elicited CD8+/IFN-γ+ T cell responses against a conserved T cell epitope present in wild type and all VOCs.

CONCLUSIONS

These results demonstrate that inclusion of different antigenic mutations from various SARS-CoV-2 variants is a feasible approach to develop cross-protective vaccines.

Design, synthesis and biological evaluations of niclosamide analogues against SARS-CoV-2

Niclosamide, a widely-used anthelmintic drug, inhibits SARS-CoV-2 virus entry through TMEM16F inhibition and replication through autophagy induction, but the relatively high cytotoxicity and poor oral bioavailability limited its application. We synthesized 22 niclosamide analogues of which compound 5 was found to exhibit the best anti-SARS-CoV-2 efficacy (IC₅₀ = 0.057 μ M) and compounds 6, 10, and 11 (IC₅₀ = 0.39, 0.38, and 0.49 μ M, respectively) showed comparable efficacy to niclosamide. On the other hand, compounds 5, 6, 11 contained higher stability in human plasma and liver S9 enzymes assay than niclosamide, which could improve bioavailability and half-life when administered orally. Fluorescence microscopy revealed that compound 5 exhibited better activity in the reduction of phosphatidylserine externalization compared to niclosamide, which was related to TMEM16F inhibition. The AI-predicted protein structure of human TMEM16F protein was applied for molecular docking, revealing that 4'-NO₂ of 5 formed hydrogen bonding with Arg809, which was blocked by 2'-Cl in the case of niclosamide.

Vaccination with SARS-CoV-2 spike protein lacking glycan shields elicits enhanced protective responses in animal models

A major challenge to end the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is to develop a broadly protective vaccine that elicits long-term immunity. As the key immunogen, the viral surface spike (S) protein is frequently mutated, and conserved epitopes are shielded by glycans. Here, we revealed that S protein glycosylation has site-differential effects on viral infectivity. We found that S protein generated by lung epithelial cells has glycoforms associated with increased infectivity. Compared to the fully glycosylated S protein, immunization of S protein with N-glycans trimmed to the mono-GlcNAc-decorated state (S_MG) elicited stronger immune responses and better protection for human angiotensin-converting enzyme 2 (hACE2) transgenic mice against variants of concern (VOCs). In addition, a broadly neutralizing monoclonal antibody was identified from S_MG-immunized mice that could neutralize wild-type SARS-CoV-2 and VOCs with subpicomolar potency. Together, these results demonstrate that removal of glycan shields to better expose the conserved sequences has the potential to be an effective and simple approach for developing a broadly protective SARS-CoV-2 vaccine.

[Anaplastic lymphoma kinase-translocation renal cell carcinoma: clinical and pathological analysis]

Objective: To investigate the clinicopathological features, molecular characteristics, differential diagnosis and prognosis of anaplastic lymphoma kinase (ALK)-translocation renal cell carcinoma. Methods: Two cases of ALK-translocation renal cell carcinoma diagnosed from January 2011 to December 2020 were retrospectively analyzed to characterize their morphological features, immunohistochemical expression and prognosis. Multiple molecular studies including fluorescence in situ hybridization (FISH), reverse transcriptase-polymerase chain reaction (RT-PCR), and next-generation sequencing were performed to characterize the genetic alterations. Results: Two patients included one male and one female, with 59 and 57 years old, respectively. Morphologically, case 1 resembled collecting duct carcinoma or renal medullary carcinoma, which demonstrated tubular, microcapsule and reticular structures, with a remarkable myxoid background and lymphocytes infiltration; case 2 resembled Xp11.2 translocation renal cell carcinoma or type 2 papillary renal cell carcinoma, which demonstrated tubular papillary and focal solid structures, with flocculent cytoplasm and many foamy histiocytes, but without myxoid background and lymphocytes infiltration. Immunohistochemistry showed strongly positive expression of ALK. CK7, E-cadherin, vimentin, PAX8 and CD10 showed various degrees of expression, and other antibodies were nonreactive. A variety of molecular assays showed definite ALK gene translocation, with rare VCL-ALK gene fusion (VCL exon and 16-ALK exon 20) in case 1, and EML4-ALK gene fusion (EML4 exon and 2-ALK exon 20) in case 2. Conclusions: ALK-translocation renal cell carcinoma is rare with various morphological features, and is easy to miss and misdiagnose. The characteristic ALK expression and molecular detection of ALK translocation are helpful for diagnosing this type of renal cell carcinoma.

[Papillary renal neoplasm with reverse polarity: a clinicopathological analysis]

Objective: To study the clinical pathological characteristics, immunophenotype, molecular changes and prognosis of the papillary renal neoplasm with reverse polarity (PRNRP). Methods: Nine cases of PRNRP, diagnosed from 2013 to 2019, were retrieved from the Department of Pathology of Nanjing Jinling Hospital, Nanjing University School of Medicine. Histomorphology, immunophenotype and molecular genetics were analyzed with review of the literatures. Results: There were five male and four female patients, aged from 49 to 70 years, with an average age of 60.1 years. During a mean follow-up of 29 months, one patient died for other cause, and the others survived without disease. Microscopically, the tumor cells arranged in papillary structure with a fibrovascular core, the surface of which was covered with a single layer of cuboidal or columnar cells. The most prominent feature was that the tumor nuclei located at the top of the cytoplasm far from the basement membrane, and they were monotonous in size and arranged neatly with no or few nucleoli. Immunohistochemically, all nine cases of PRNRP showed diffuse positive expression of CK7 and E-cadherin, various degrees of P504s expression, and no expression of CD10 and CD117, with a Ki-67 index of 1%-3%. Unlike other papillary renal cell carcinoma, the nine cases of PRNRP all showed characteristic positive expression of GATA3. The fluorescence in situ hybridization assay showed that the majority of PRNRPs (8/9) did not have triploids on chromosomes 7 and 17. The sequencing of the KRAS gene confirmed the presence of a nonsense KRAS mutation in 8 of the 9 cases. Conclusions: PRNRP is a subtype of papillary renal cell carcinoma with characteristic morphological, immunophenotypic and molecular features, and indolent behaviors. More data are needed to define PRNRP as "carcinoma", and a definitive diagnosis of PRNRP is of great significance for proper treatment choice and accurate prognostication.

Vaccinia virus-based vaccines confer protective immunity against SARS-CoV-2 virus in Syrian hamsters

COVID-19 in humans is caused by Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that belongs to the beta family of coronaviruses. SARS-CoV-2 causes severe respiratory illness in 10-15% of infected individuals and mortality in 2-3%. Vaccines are urgently needed to prevent infection and to contain viral spread. Although several mRNA- and adenovirus-based vaccines are highly effective, their dependence on the "cold chain" transportation makes global vaccination a difficult task. In this context, a stable lyophilized vaccine may present certain advantages. Accordingly, establishing additional vaccine platforms remains vital to tackle SARS-CoV-2 and any future variants that may arise. Vaccinia virus (VACV) has been used to eradicate smallpox disease, and several attenuated viral strains with enhanced safety for human applications have been developed. We have generated two candidate SARS-CoV-2 vaccines based on two vaccinia viral strains, MVA and v-NY, that express full-length SARS-CoV-2 spike protein. Whereas MVA is growth-restricted in mammalian cells, the v-NY strain is replication-competent. We demonstrate that both candidate recombinant vaccines induce high titers of neutralizing antibodies in C57BL/6 mice vaccinated according to prime-boost regimens. Furthermore, our vaccination regimens generated TH1-biased immune responses in mice. Most importantly, prime-boost vaccination of a Syrian hamster infection model with MVA-S and v-NY-S protected the hamsters against SARS-CoV-2 infection, supporting that these two vaccines are promising candidates for future development. Finally, our vaccination regimens generated neutralizing antibodies that partially cross-neutralized SARS-CoV-2 variants of concern.

CpG-adjuvanted stable prefusion SARS-CoV-2 spike protein protected hamsters from SARS-CoV-2 challenge

The COVID-19 pandemic presents an unprecedented challenge to global public health. Rapid development and deployment of safe and effective vaccines are imperative to control the pandemic. In the current study, we applied our adjuvanted stable prefusion SARS-CoV-2 spike (S-2P)-based vaccine, MVC-COV1901, to hamster models to demonstrate immunogenicity and protection from virus challenge. Golden Syrian hamsters immunized intramuscularly with two injections of 1 µg or 5 µg of S-2P adjuvanted with CpG 1018 and aluminum hydroxide (alum) were challenged intranasally with SARS-CoV-2. Prior to virus challenge, the vaccine induced high levels of neutralizing antibodies with 10,000-fold higher IgG level and an average of 50-fold higher pseudovirus neutralizing titers in either dose groups than vehicle or adjuvant control groups. Six days after infection, vaccinated hamsters did not display any weight loss associated with infection and had significantly reduced lung pathology and most importantly, lung viral load levels were reduced to lower than detection limit compared to unvaccinated animals. Vaccination with either 1 μg or 5 μg of adjuvanted S-2P produced comparable immunogenicity and protection from infection. This study builds upon our previous results to support the clinical development of MVC-COV1901 as a safe, highly immunogenic, and protective COVID-19 vaccine.

Identification of existing pharmaceuticals and herbal medicines as inhibitors of SARS-CoV-2 infection

The outbreak of COVID-19 caused by SARS-CoV-2 has resulted in more than 50 million confirmed cases and over 1 million deaths worldwide as of November 2020. Currently, there are no effective antivirals approved by the Food and Drug Administration to contain this pandemic except the antiviral agent remdesivir. In addition, the trimeric spike protein on the viral surface is highly glycosylated and almost 200,000 variants with mutations at more than 1,000 positions in its 1,273 amino acid sequence were reported, posing a major challenge in the development of antibodies and vaccines. It is therefore urgently needed to have alternative and timely treatments for the disease. In this study, we used a cell-based infection assay to screen more than 3,000 agents used in humans and animals, including 2,855 small molecules and 190 traditional herbal medicines, and identified 15 active small molecules in concentrations ranging from 0.1 nM to 50 μM. Two enzymatic assays, along with molecular modeling, were then developed to confirm those targeting the virus 3CL protease and the RNA-dependent RNA polymerase. Several water extracts of herbal medicines were active in the cell-based assay and could be further developed as plant-derived anti-SARS-CoV-2 agents. Some of the active compounds identified in the screen were further tested in vivo, and it was found that mefloquine, nelfinavir, and extracts of Ganoderma lucidum (RF3), Perilla frutescens, and Mentha haplocalyx were effective in a challenge study using hamsters as disease model.

[Analysis of five cases of hepatitis associated aplastic anemia presenting with hemophagocytic lymphohistiocytosis at onset]

Objective: To discuss the clinical characteristics and management approaches to hepatitis associated aplastic anemia (HAAA) presenting as hemophagocytic lymphohistiocytosis (HLH) at onset. Methods: The clinical data and laboratory results of hospitalized 5 HAAA patients presenting as HLH at onset in Beijing Children's Hospital from January 2017 to May 2019 were analyzed retrospectively. Results: Among 5 cases, there were 4 males and 1 female. The age of onset was 6.0 (2.7-12.7) years. All patients presented with high fever, hepatomegaly, hepatic dysfunction (aspartate aminotransferase 1 716 (1 409-2 570) U/L, alanine aminotransferase 1 699 (937-2 540) U/L) at onset. After admission, the laboratory results showed pancytopenia (white blood cell 1.2 (0.6-6.7) ×10(9)/L, haemoglobin 94 (65-111) g/L, blood platelet 29 (10-41) ×10(9)/L), decreased fibrinogen (1.3 (1.1-2.5) g/L), significantly elevated triglyceride (4.0 (2.8-5.1) mmol/L), ferritin (1 766 (399-5 253) μg/L) and soluble CD25 (27 457 (9 625-44 000) ng/L). Hemophagocytosis was found in the bone marrow smears of all 5 patients. The diagnosis of acute hepatitis and HLH was confirmed. During the treatment of HLH, the blood cells remain below normal level and the further biopsy of bone marrow (iliac bone) indicated low myeloproliferation. After exclusion of congenital bone marrow failure syndromes and other pancytopenic diseases, HAAA was confirmed. After the diagnosis of HAAA, 1 patient received antithymocyte globulin (ATG) and cyclosporin treatment in our hospital, 1 patient received allogeneic stem cell transplantation (HSCT) in other hospital, 2 patients received ATG in other hospitals. Only 1 patient died of severe infection. Conclusions: HAAA can present as HLH at onset. It is mainly manifested by high fever, acute severe hepatitis, pancytopenia, elevated ferritin and hemophagocytosis in the bone marrow. The diagnosis of HAAA should be considered whenever cytopenia could not completely corrected while apparent improvement of HLH and hepatitis related complications were improved after immunosuppressive therapy. ATG or HSCT treatment should be performed as soon as the diagnosis of severe or transfusion dependent aplastic anemia is confirmed.

[Expression of H3.3 G34W mutant-specific antibody in giant cell tumors of bone and its diagnostic value]

Objective: To investigate the expression of H3.3 G34W mutant-specific antibody in giant cell tumors of bone (GCTB), and its value in the diagnosis of GCTB. Methods: Immunohistochemical (IHC) EnVision method was used to detect the expression of H3.3 G34W mutant-specific antibody and p63 in 83 GCTBs, 18 aneurysmal bone cysts, 23 chondroblastomas and 28 osteosarcomas diagnosed at Nanjing Jinling Hospital from June 2001 to April 2019. Results: Among the 83 cases of GCTB, 69 cases (69/83, 83.1%) expressed H3.3 G34W. H3.3 G34W expression was found exclusively in the mononuclear cell population with strong and diffuse nuclear staining. H3.3 G34W was expressed in 55 of 57 (96.5%) cases of GCTB in long bones, but only 14 of 26 (53.8%) cases of non-long bone GCTB. All recurrent (9/9)/metastatic GCTB (2/2), post-denosumab GCTB (3/3), primary malignant GCTB (3/3) and secondary malignant GCTB (5/5) also expressed H3.3 G34W. H3.3 G34W was negative in all aneurysmal bone cysts and chondroblastomas. H3.3 G34W was positive in 3 of 28(10.7%) cases of osteosarcomas, and giant cell-rich osteosarcoma(GCRO) was the only histological subtype of osteosarcoma that expressed H3.3 G34W. p63 was expressed in 71.1%(59/83) of GCTB, while the positive rates of p63 in aneurysmal bone cysts,chondroblastomas and osteosarcomas were 3/18, 43.5% (10/23) and 21.4% (6/28) respectively. The sensitivity and specificity of H3.3 G34W mutant-specific antibody in the diagnosis of GCTB were 83.1% and 95.7%. Conclusions: H3.3 G34W mutant-specific antibody is a highly sensitive and specific marker for GCTB and helpful for the diagnosis of GCTB and its variants. The limitation of this antibody is that as a mall number of GCTB harbor G34 mutation other than G34W, and thus that cannot be detected. The incidental expression of H3.3 G34W mutant protein in osteosarcoma could be a potential diagnostic dilemma, and the results of H3.3 G34W IHC staining needs careful interpretation.

[Eosinophilic solid and cystic renal cell carcinoma: clinicopathological analysis and molecular characterization]

Objective: To study the clinicopathological features, immunohistochemical phenotype, molecular changes, differential diagnosis and prognosis of eosinophilic solid and cystic renal cell carcinoma (ESC RCC). Methods: A total of 15 cases were selected from 2005 to 2019 at Nanjing Jinling Hospital,Nanjing University School of Medicine for clinicopathological and immunohistochemical analysis, 10 of which were subject to cancer-associated mutation analysis using targeted next-generation sequencing (NGS) panel. A literature review was also performed. Results: The patients' ages ranged from 15 to 68 years (mean, 33 years). The male-to-female ratio was 1.1∶1.0. During a mean follow-up of 22 months, none of the patients developed tumor recurrence, progression or metastasis. Histologically, the tumors typically demonstrated solid and cystic architectures and the neoplastic cells contained voluminous eosinophilic cytoplasm with prominent granular cytoplasmic stippling. Immunohistochemically, tumor cells in all cases were immunoreactive for CK20. Signal pathway related protein mTOR and S6 were positive in 14/15 and 6/15 cases, respectively. Cathepsin K, Melan A and HMB45 were at least focally positive in 12/15, 6/15 and 2/15 cases, respectively. CK7 and CD10 showed focal immunostain positivity in some cases, while TFE3, TFEB, CA9 and CD117 were negative in all cases. NGS demonstrated TSC1/TSC2 mutations in all tested cases (10/10). Conclusions: ESC RCC is a rare tumor that tends to occur in young patients with an indolent behavior. Diagnosis can be established by its distinct clinical and histopathologic findings, immunohistochemical phenotype and molecular genetics. The tumor may be considered as a new subtype of RCC.

[Primary mediastinal large B-cell lymphoma: a clinicopathologic study of 27 cases]

Objective: To study the clinicopathologic characteristics and diagnostic criteria of primary mediastinal B-cell lymphoma (PMBL), and to distinguish PMBL from classic Hodgkin lymphoma(CHL) and systemic diffuse large B-cell lymphoma(DLBCL). Methods: The clinical features, histologic findings, results of immunohistochemical study and prgnosis in 27 PMBL cases were analyzed, with review of literature. Results: The age of patients ranged from 19 to 82 years (median age 34 years). All cases were located in the mediastinum and frequently accompanied by superior vein cava syndrome. Histologically, the tumor cells were pleomorphic and diffusely distributed. Clear cytoplasm and spindle tumor cells were seen in some cases. Varying amount of sclerosing stroma with collagen deposition was seen.Immunohistochemical study showed that the tumor cells were positive for CD20(100%, 27/27), CD30 (64.0%, 16/25), CD23 (77.3%, 17/22) and p63 (16/19). Clonal B cell gene rearrangement was seen. Conclusions: PMBL is a subtype of diffuse large B-cell lymphoma with various histomorphology. Immunohistochemistry can help to confirm the diagnosis, and the prognosis is better than diffuse large B cell lymphoma, not otherwise specified.

[Molecular features of metanephric adenoma and their values in differential diagnosis]

Objective: To study the molecular features of metanephric adenoma (MA) and discuss their values in differential diagnosis. Methods: BRAF V600E immunohistochemistry (IHC) using the mutation-specific VE1 monoclonal antibody and Sanger sequencing of BRAF mutations were performed on 21 MAs, 16 epithelial-predominant Wilms tumors (e-WT) and 20 the solid variant of papillary renal cell carcinomas (s-PRCC) respectively. p16 protein was detected by IHC also. Fluorescence in situ hybridization (FISH) analyses using centromeric probes for chromosome 7 and 17 were performed on the three renal tumors in parallel. Results: Fourteen (14/21, 66.7%) of 21 MA cases demonstrated diffuse, moderate to strong cytoplasmic BRAF V600E IHC staining and the BRAF V600E protein expression was detected in 2 (2/16) of 16 e-WT cases for the first time, whereas all s-PRCCs were negative (P<0.05). All cases (including 14 MAs and 2 e-WTs) with diffuse, moderate to strong cytoplasmic BRAF V600E IHC staining were confirmed to harbor BRAF V600E missense mutations using Sanger sequencing, and no BRAF mutations were detected in cases with negative BRAF V600E protein expression. One case (1/21, 4.8%) showed trisomy of chromosome 7 alone, and another one (1/21, 4.8%) showed trisomy of chromosome 17 alone in 21 MAs. Two cases (2/16) of 16 e-WTs showed trisomy of chromosome 17 alone. In 20 s-PRCCs, trisomy of chromosomes 7 alone was reported in 2 cases (2/20), trisomy of chromosome 17 alone in 3 cases (3/20) and trisomy of chromosome 7 and 17 in 14 cases (14/20). The total positive rates of trisomy of chromosome 7 and/or 17 in MAs, e-WTs and s-PRCCs were 9.6% (2/21), 2/16 and 95.0% (19/20). p16 protein was positive in 81.0% (17/21) MAs, whereas the positive rates in e-WTs and s-PRCCs were 2/16 and 5.0% (1/20). Conclusions: Most MAs harbor BRAF V600E mutations, and MAs lack the gains of chromosome 7 and 17 that are characteristic of papillary renal cell carcinoma. These molecular features can be used to distinguish MA from its mimics. BRAF V600E IHC using the mutation-specific VE1 monoclonal antibody provides an effective method in BRAF V600E mutations detection of renal tumors. p16 is overexpressed in MA, and the finding suggests that the low proliferative rate of the tumor might be attributed to BRAF V600E-induced senescence mediated by p16.

[Application of BRAF V600E mutation-specific immunohistochemistry in diagnosis of gastrointestinal stromal tumors]

OBJECTIVE

To evaluate the utility of BRAF V600E allele-specific antibody in the diagnosis of gastrointestinal stromal tumors (GISTs).

METHODS

BRAF V600E mutation-specific immunohistochemistry and BRAF sequencing were performed in 24 consecutive GISTs, including 14 cases of KIT or PDGFRA mutations and 10 cases of KIT/PDGFRA wild GISTs.

RESULTS

GISTs of 11 men and 13 women with a mean age 54 years(range 29-75 years) were included with tumors arising from stomach (16 cases), small bowel (7 cases), and peritoneal cavity (1 case). Strong and diffuse cytoplasmic BRAF staining was noted in 4 of 24 cases (17%), while 1 of 24 cases (4%) showed weak staining, and 19 of 24 cases (79%) had no staining. The four cases with strong BRAF immunostain were confirmed to have BRAF mutations, including 3 cases in the stomach and 1 case in the small intestine. All tumors showed spindle cell morphology. Only one case had progressive disease. No BRAF mutations were detected in cases with weak or negative BRAF immunostain.

CONCLUSION

BRAF V600E mutation-specific immunohistochemistry is a highly sensitive and specific marker for detecting BRAF-mutated GISTs.

[Expression of cadherin17 in metanephric adenoma and its value in differential diagnosis]

OBJECTIVE

To study the expression of cadherin17(CDH17) in metanephric adenoma (MA), and to explore the value of CDH17 in the diagnosis of metanephric adenoma.

METHODS

Immunohistochemical EnVision method was used to detect the expression of CDH17, WT1, CD57, P504S and EMA in 21 cases of MAs, 16 epithelial-predominant Wilms tumors (e-WT), and 20 solid variant of papillary renal cell carcinomas (s-PRCC). The expression of CDH17 was also examined in other common renal epithelial tumors, including 10 cases of clear cell renal cell carcinomas (CCRCC), 10 chromophobe renal cell carcinomas (CHRCC), and 10 oncocytomas.

RESULTS

Twenty (95.2%) of 21 cases of MAs demonstrated membranous CDH17 immunoreactivity in all components (acinar, tubular, and papillary), whereas only 1 (1/16) e-WT was positive for CDH17 and all s-PRCCs were negative (P<0.05). WT1 was negative in s-PRCC and was positive in all cases of e-WT (16/16) and MA (100%, 21/21). All MAs (100%) were strongly positive for CD57; however, this marker was also positive in 13 (13/16) e-WTs and 9 (45.0%, 9/20) s-PRCCs. P504S was strongly positive in all s-PRCCs (100%), but reactivity was seen in 3 (14.3%, 3/21) MAs and all e-WTs were negative. The positive rates of EMA in MAs, e-WTs and s-PRCCs were 19.0%(4/21), 14/16 and 17/20, respectively. The sensitivity and specificity of CDH17 in the diagnosis of MA were 95% and 97%. CDH17 was negative in all cases of CCRCC, CHRCC and oncocytoma.

CONCLUSIONS

CDH17 is a highly sensitive and specific marker for MA and should be considered in the immunohistochemistry panel for distinguishing MA from its mimics and other common renal epithelial tumors.

Supercritical water oxidation of acrylic acid production wastewater

Supercritical water oxidation (SCWO) of wastewater from an acrylic acid manufacturing plant has been studied on a continuous flow experimental system, whose reactor was made of Hastelloy C-276. Experimental conditions included a reaction temperature (T) ranging from 673 to 773K, a residence time (t) ranging from 72.7 to 339s, a constant pressure (P) of 25 MPa and a fixed oxidation coefficient (alpha) of 2.0. Experimental results indicated that reaction temperature and residence time had significant influences on the oxidation reaction, and increasing the two operation parameters could improve both degradation of chemical oxygen demand (COD) and ammonia nitrogen (NH3-N). The COD removal efficiency could reach up to 98.73% at 25 MPa, 773 K and 180.1 s, whereas the destruction efficiency of NH3-N was only 43.71%. We further carried out a kinetic analysis considering the induction period through free radical chain mechanism. It confirms that the power-law rate equation for COD removal was 345 exp(-52200/RT)[COD]1.98[O2]0.17 and for NH3-N removal was 500 exp(-64492.19/RT)[NH3-N]1.87 [O2]0.03. Moreover, the induction time formulations for COD and NH3-N were suspected to be exp(38250/RT)/173 and exp(55690/RT)/15231, respectively. Correspondingly, induction time changed from 2.22 to 5.38 s for COD and 0.38 to 1.38 s for NH3-N. Owing to the catalysis of reactor inner wall surface, more than 97% COD removal was achieved in all samples.

Giant enhancement of surface second-harmonic generation using photorefractive surface waves with diffusion and drift nonlinearities

Giant enhancement of second-harmonic generation (SHG) with 83.4%/W coversion efficiency is obtained, taking advantage of photorefractive surface waves with diffusion and drift nonlinearity. In this method, the self-bending induced by diffusion nonlinearity can be utilized at the surface and can solve the phase-mismatch problem in bulk due to beam self-bending. With drift nonlinearity, an applied external electric filed and background illumination can further constringe surface waves to the surface and consequently enhance SHG, which provides the possibility and flexibility of control.

(2+1)D surface solitons in virtue of the cooperation of nonlocal and local nonlinearities

We introduce a type of (2+1)D surface soliton in virtue of the cooperation of nonlocal and local nonlinearities. Furthermore, taking advantage of diffusion and drift nonlinearity this type of surface soliton is demonstrated theoretically and experimentally in a storintium barium nitrate crystal. The dynamics behavior of the excitation and propagation of this type of surface soliton are studied using the beam-propagation method and the nonlinear equation of light rays.

Influences of MxA gene -88 G/T and IFN-gamma +874 A/T on the natural history of hepatitis B virus infection in an endemic area

The influence of human genetics on the natural history of hepatitis B virus (HBV) infection may be diminished in endemic areas because infection at a young age predisposes to chronic HBV infection. The present study aimed to address this issue through the determination of the influences of single nucleotide polymorphisms (SNPs) of myxovirus resistence-1 (MxA) -88 G/T and interferon (IFN)-gamma +874 A/T on the natural history of HBV infection in endemic regions. One hundred adult patients with self-limiting HBV infection (positive for both anti-HBs and anti-HBc) and 340 adult patients with persistent HBV infection were recruited from southern China, an endemic area with an HBsAg carrier rate of 17.8%. SNPs of MxA -88 G/T and interferon (IFN)-gamma +874 A/T were typed using a protocol based on competitively differentiated polymerase chain reaction. A highly significant difference in the distribution of MxA -88 G/T was observed between those with persistent and self-limiting HBV infections. The latter displayed a lower frequency of the GG genotype (41.0% vs. 52.9%, P = 0.036) and a higher frequency of the TT genotype (16.0% vs. 2.4%, P = 0.000), compared to patients with persistent infection. These differences were not gender- or age-specific. However, a significant distribution difference of IFN-gamma +874 A/T was not observed. Between two groups of patients, respectively, the distribution frequencies of the AA genotype (65.0% vs. 72.8%, P = 0.139) and the TT genotype (2.0% vs. 1.2%, P = 0.894) were found. These results suggest that MxA gene -88 G/T and IFN-gamma +874 A/T behave differently in endemic HBV infections. Further study is necessary to clarify the influences of human genetics on endemic HBV infections.

[Detection of coxsackie virus B3 gene in myocardium and spleen samples in myocarditis with sudden death]

OBJECTIVE

To detect the Coxsackie virus B3(CVB3) gene in myocardium and spleen tissues in viral myocarditis(VMC) with sudden death and to explore the diagnostic method for VMC by means of seeking pathogene.

METHODS

By in situ RT-PCR, the detection of CVB3 gene in myocardium and spleen sections were performed in sudden death group caused by VMC and non-cardiac death group.

RESULTS

In VMC group, CVB3 gene-positive signals were seen in myocardium sections(3 out of total 8 cases, No. 1, 4, 7 cases) and spleen sections(4 out of total 8 cases, No. 2, 4, 6, 7 cases). In non-cardiac death group, no positive signals were detected in both myocardium and spleen tissues.

CONCLUSION

Positive detection of CVB3 gene in both myocardium and spleen maybe an important character of VMC and can improve the detecting pathogene in diagnosing VMC.

Parameterization of inoculum effect via mathematical modeling: aminoglycosides against Staphylococcus aureus and Escherichia coli

Inoculum effect describes the inoculum size dependent changes in minimum inhibitory concentrations (MIC) exhibited by antibiotic-bacterium combinations demonstrating such effect. Traditionally, inoculum effect has been loosely defined based on the extent of increase in the MIC with respect to the increase in inoculum size. In most studies, assessment of MIC data has relied on the arbitrary selection of a point of reference for both baseline MIC and inoculum size. More importantly, this conventional method of assessment does not permit information conveyed in a complete MIC versus inoculum size profile to be fully explored. To undertake these issues, a mathematical model was developed for the description of the entire inoculum effect profile. With the employment of three key parameter estimates, i.e., the baseline MIC, the threshold inoculum size at which the increase in MIC commences, and the rate of increase in MIC with respect to inoculum size, both the shape and location of the profile could be adequately defined. To verify the application of this model, a series of four aminoglycosides were tested against standard strains of E. coli and S. aureus. Results showed a good degree of organism specificity and antibiotic-class dependency of the inoculum effect profiles. Analysis of the parameter estimates obtained provided further support for these observations. In conclusion, the mathematical model developed in the present study adequately described the inoculum effect exhibited by the various aminoglycoside-bacterium combinations tested. The parameter estimates generated by the modeling approach allowed comparison and quantitative analysis of the inoculum effect profiles with minimal difficulties.

Mitral insufficiency as a complication of acute myocardial infarction and left ventricular remodeling

The presence of mitral insufficiency after acute myocardial infarction (AMI) often leads to hemodynamic impairment and heart failure. This study was designed to examine the relationship between mitral regurgitation (MR), an indicator of mitral insufficiency, and the course of recovery from AMI. We evaluated the course of MR after AMI in 223 patients by color Doppler echocardiography. MR was detected in 21% (47/223) of patients at the onset of AMI, and developed in 18% (40/223) of patients during follow-up. Patients were grouped according to the course of MR as well as the success of acute recanalization therapy. No correlation was observed between the presence or course of MR and the site of infarction. The incidence of successful recanalization was higher in patients with MR that improved during follow-up than in patients with MR that was unchanged or that worsened during follow-up. Although no significant differences in hemodynamic variables were noted among the groups at admission, the group with unsuccessful recanalization and unimproved MR (BS-) showed a significantly greater left ventricular end-diastolic diameter (LVDd), left ventricular end-systolic diameter, and left ventricular end-diastolic volume (LVEDV) as well as a lower left ventricular ejection fraction than patients with successful recanalization and no MR (CS+) during the convalescent period. The extent of change in LVDd and LVEDV between admission and convalescence was significantly greater in the BS(-) group than in the CS(+) group. The results suggest that successful recanalization after AMI reduces the incidence of MR. Acute recanalization therapy after AMI may prevent left ventricular remodeling, resulting in a secondary improvement of MR.

Unilateral cleft lip repair without making incisions on the lip surface. A modified Millard operation

In clinical and anatomical studies carried out during 1986-1990, two new findings were identified: a small spade-shaped myocutaneous tag which can often be found at the medial side of the cleft near the columella base and the levator septi nasi muscle which draws the cleft side of the philtrum upwards. With the full use of the two findings, a method of unilateral cleft lip repair without making incisions on the lip surface was developed. Since 1986, 52 cases of unilateral cleft lip have been repaired with this method. The early and late results were gratifying.