[Mid-term efficacy of China Net Childhood Lymphoma-mature B-cell lymphoma 2017 regimen in the treatment of pediatric Burkitt lymphoma]

Objective: To analyze the clinical characteristics of children with Burkitt lymphoma (BL) and to summarize the mid-term efficacy of China Net Childhood Lymphoma-mature B-cell lymphoma 2017 (CNCL-B-NHL-2017) regimen. Methods: Clinical features of 436 BL patients who were ≤18 years old and treated with the CNCL-B-NHL-2017 regimen from May 2017 to April 2021 were analyzed retrospectively. Clinical characteristics of patients at disease onset were analyzed and the therapeutic effects of patients with different clinical stages and risk groups were compared. Survival analysis was performed by Kaplan-Meier method, and Cox regression was used to identify the prognostic factors. Results: Among 436 patients, there were 368 (84.4%) males and 68 (15.6%) females, the age of disease onset was 6.0 (4.0, 9.0) years old. According to the St. Jude staging system, there were 4 patients (0.9%) with stage Ⅰ, 30 patients (6.9%) with stage Ⅱ, 217 patients (49.8%) with stage Ⅲ, and 185 patients (42.4%) with stage Ⅳ. All patients were stratified into following risk groups: group A (n=1, 0.2%), group B1 (n=46, 10.6%), group B2 (n=19, 4.4%), group C1 (n=285, 65.4%), group C2 (n=85, 19.5%). Sixty-three patients (14.4%) were treated with chemotherapy only and 373 patients (85.6%) were treated with chemotherapy combined with rituximab. Twenty-one patients (4.8%) suffered from progressive disease, 3 patients (0.7%) relapsed, and 13 patients (3.0%) died of treatment-related complications. The follow-up time of all patients was 24.0 (13.0, 35.0) months, the 2-year event free survival (EFS) rate of all patients was (90.9±1.4) %. The 2-year EFS rates of group A, B1, B2, C1 and C2 were 100.0%, 100.0%, (94.7±5.1) %, (90.7±1.7) % and (85.9±4.0) %, respectively. The 2-year EFS rates was higher in group A, B1, and B2 than those in group C1 (χ²=4.16, P=0.041) and group C2 (χ²=7.21, P=0.007). The 2-year EFS rates of the patients treated with chemotherapy alone and those treated with chemotherapy combined with rituximab were (79.3±5.1)% and (92.9±1.4)% (χ²=14.23, P<0.001) respectively. Multivariate analysis showed that stage Ⅳ (including leukemia stage), serum lactate dehydrogenase (LDH)>4-fold normal value, and with residual tumor in the mid-term evaluation were risk factors for poor prognosis (HR=1.38,1.23,8.52,95%CI 1.05-1.82,1.05-1.43,3.96-18.30). Conclusions: The CNCL-B-NHL-2017 regimen show significant effect in the treatment of pediatric BL. The combination of rituximab improve the efficacy further.

[Interpretation for the group standards in technical specification for health risk investigation of central air conditioning ventilation system during coronavirus disease 2019 epidemic]

The central air conditioning ventilation system plays an important role in the air circulation of buildings such as centralized isolation medical observation points and general public buildings. In order to meet the requirements of COVID-19 epidemic prevention and control, Beijing Preventive Medicine Association organized Beijing CDC and other professional institutes to write up the group standard entitled "Technical specification for health risk investigation of central air conditioning ventilation system during the COVID-19 epidemic (T/BPMA 0006-2020)" . According to the particularity of central air conditioning ventilation system risk control during the outbreak of similar respiratory infectious diseases, based on current laws and regulations and the principle of scientific, practical, consistency and normative, 8 key points of risk investigations were summarized, which were the location of fresh air outlet, air conditioning mode, air return mode, air system, air distribution, fresh air volume, exhaust and air conditioner components. The contents, process, method, data analysis and conclusion of the investigation implementation were also defined and unified. It could standardize and guide institutions such as disease control and health supervision to carry out relevant risk managements, and provided solutions and technical supports for such major public health emergencies in city operations.

[Chimeric antigen receptors T cells for treatment of 48 relapsed or refractory acute lymphoblastic leukemia children: long term follow-up outcomes]

Objective: To evaluate the safety and efficacy of chimeric antigen receptors T cells (CAR-T) in childhood acute B lymphoblastic leukemia (B-ALL) to probe the prognosis-related factors. Methods: Forty-eight children, 29 boys and 19 girls, aged 3-17years old (median age was 8 years old) , with recurrent or refractory CD19 positive B-ALL, were treated by the CD19 specific CAR-T cells. A total of 48 cases received 61 infusions. Flow cytometry or real-time quantitative polymerase chain reaction method were used to monitor micro residual disease (MRD) . The follow-up period was from 16 to 1 259 days with the median follow-up of 406 days. SPSS software was used to statistical analysis. Results: No adverse reaction was observed during 61 infusions. The most common adverse reaction after CAR-T cell infusions was cytokine-release syndrome (CRS) . Only 2 cases experienced level 3 CRS performance, including continuous high fever, convulsions, delirium, serous cavity effusion, and decreasing of blood pressure. Tocilizumab was given to release CRS performance. No treatment-related death occurred. Thirty-seven patients showed response during 7 to 28 days after infusions. The early response rate was 77.1%, with MRD before infusion less than 5% group higher than the MRD more than 5% group (87.1% vs 58.8%, χ2=4.968, P=0.036) . For the 37 patients who showed response to CAR-T cell infusions, univariate analysis identified that age, disease status at the time of treatment, MRD before infusion affected 2-year OS rate (P<0.05) . Multivariate prognostic analysis for EFS disclosed that the MRD before infusion more than 5% (RR=3.433, 95% CI 1.333-8.844, P=0.011) and not bridge to HSCT (RR=4.996, 95% CI 1.852-13.474, P=0.001) were the independent risk factors. Conclusion: The fourth generation CAR-T cells directed against CD19 could effectively and safely treat relapsed and refractory B-ALL, which implicated that CAR-T therapy as a novel therapeutic approach could be useful for patients with relapsed or refractory B-ALL who have failed all other treatment options. Reducing MRD as far as possible by effective pretreatment chemotherapy was in favor of increasing the response rate. Bridging HSCT after CAR-T cell treatment might be a better therapeutic strategy for the patient with refractory or molecular relapsed B-ALL.

[Prognostic factors of pediatric patients with Ph-positive acute lymphoblastic leukemia]

Objective: To explore the clinical features and prognostic factors of Ph-positive and/or BCR-ABL positive acute lymphoblastic leukemia (Ph⁺ ALL) in children. Methods: The clinical data of 68 Ph⁺ ALL children who were treated at Peking University People's Hospital from December 2006 to December 2016 was retrospectively reviewed. Survival analysis were estimated by Kaplan-Meier method. Univariate analysis was estimated by Log-rank test and Chi-square, and multivariate analysis was estimated by Cox proportional hazards regression model. Results: In the 68 cases, the proportion of male to female was 2.1∶1, with a median age of 8 (1-16) years, and the median overall survival (OS) and disease free survival (DFS) were 16.8 months and 13.5 months, respectively. The early response rate to treatment was 43.9%, with myeloid-antigens-expression group lower than the non-expression group (29.6% vs 61.3%, χ²=5.814, P=0.020); The complete remission (CR) rate after one-course induction therapy was 86.2% (56/65), with good-response group higher than the poor-response group (100.0% vs 74.2%, χ²=6.680, P=0.003);The CR rate after induction in patients receiving imatinib plus chemotherapy was higher than the patients receiving chemotherapy only (94.9% vs 73.1%, χ²=5.185, P=0.024). The 2-and 5-year OS were (61.4±7.0)% and (50.8±8.1)%, respectively. The 2-and 5-year DFS were (54.6±6.8)% and (48.6±7.3)%, respectively. Univariate analysis showed that the initial WBC, LDH, spleen size, liver size, with-myeloid-antigens-expression, early response to treatment, MRD (BCR-ABL) after one-course induction, application of imatinib and different treatment options affected 2-year OS rate (all P<0.05). LDH, spleen size, liver size, with-myeloid-antigens-expression, early response to treatment, MRD (BCR-ABL) after one-course induction, application of imatinib and different treatment options affected 2-year DFS rate (all P<0.05). Multivariate prognostic analysis for OS (RR=45.7, 95% CI 1.4-1 528.2, P=0.033) and DFS (RR=52.3, 95% CI 1.6-1 725.9, P=0.026) showed that the spleen ≥ 3 cm was the independent risk factor. Conclusions: Pediatric Ph⁺ ALL is a special condition with unique clinical and biological features. The early response to treatment was poor in patients with myeloid-antigens-expression, which resulted in a low CR rate after one-course induction and the administration of imatinib can remarkably improve the CR rate. Initial spleen ≥ 3 cm is an independent prognostic factor. The efficacy of chemotherapy alone is poor, and imatinib combined with chemotherapy is applauded in the aim of improving outcomes.

[Study on the three-dimensional mapping to reduce the X-ray exposure dose of interventional doctors in radiofrequency catheter ablation of atrioventricular nodal reentry tachycardia]

Objective: To explore the advantage of radiofrequency catheter ablation under the three-dimensional mapping in the treatment of atrioventricular nodal reentrant tachycardia (AVNRT) in reducing the X-ray exposure dose of interventional doctors. Methods: 79 patients with AVNRT, in the first hospital of Shanxi Medical University from January 2015 to June 2016, performed to do radiofrequency catheter ablation treatment were selected, and according to the random number method were divided into two-dimensional mapping group and three-dimensional mapping group. The two-dimensional mapping group was mapped the ablation target at the X-ray, while the ablation target was mapped by CARTO 3 system in the three-dimensional mapping group. Compare the X-ray fluoroscopy time, success rate, complications rate and doctor's X-ray exposure dose between the two groups. Results: Compared with the two-dimensional mapping group, acute success rate and complication rate of the three dimensional mapping group were not statistically significant (P>0.05) , while the X-ray fluoroscopy time and the X-ray dose of the three-dimensional mapping group decreased significantly, the difference was statistically significant (P<0.05) . Conclusion: Three-dimensional mapping can significantly reduce the X-ray irradiation time and interventional doctor's X-ray exposure dose in radiofrequency catheter ablation of AVNRT patients and the potential hazards of ionizing radiation on the human body.

[Preliminavy clinical study of the treatment of hemorrhoids by superselective embolization of superior rectal artery]

Objective: To investigate the safety and feasibility of the treatment of hemorrhoids by superselective arterial embolization. Methods: The clinical data of 15 patients with grade Ⅱ to Ⅳ hemorrhoids were collected who were treated by superselective SRA embolization.According to the number and shape of SRA in the vicinity of the dentate line, chosed coils, PVA particles and gelfoam particles, ethanol and bletilla mixture of gelfoam particles for embolization.And intraoperative operations, postoperative complications, follow-up treatment results were observed. Results: The interventional procedures were successfully accomplished in all 15 cases.The operation time was (30±14) min, and the hospital stay was 1-7 (2.0±1.8) days after operation, and the patients recovered to normal life in 12 hours after the operation.Tenesmus (14/15), pain (5/15) and low fever (11/15) can alleviate without special treatment. All patients were follow up (19.0±2.6) months, bleeding symptoms were cured, there's no serious complications. Conclusion: The treatment of hemorrhoids by transcatheter superselective embolization of superior rectal artery is technically safe and feasible.

Helicobacter pylori CagA Protein Negatively Regulates Autophagy and Promotes Inflammatory Response via c-Met-PI3K/Akt-mTOR Signaling Pathway

Cytotoxin-associated-gene A (CagA) of Helicobacter pylori (H. pylori) is a virulence factor that plays critical roles in H. pylori-induced gastric inflammation. In the present study, gastric biopsies were used for genotyping cagA and vacA genes, determining the autophagic activity, and the severity of gastric inflammation response. It was revealed that autophagy in gastric mucosal tissues infected with cagA⁺H. pylori strains was lower than the levels produced by cagA^-H. pylori strains, accompanied with accumulation of SQSTM1 and decreased LAMP1 expression. In vitro, deletion mutant of cagA gene resulted in increased autophagic activity, and decreased expression of SQSTM1 and cytokines, whereas over-expression of CagA down-regulated the starvation-induced autophagy, and induced more production of the cytokines. Moreover, the production of the cytokines was increased by inhibition of autophagy, but decreased by enhancement of autophagy. Deletion of CagA decreased the ability to activate Akt kinase at Ser-473 site and increased autophagy. c-Met siRNA significantly affected CagA-mediated autophagy, and decreased the level of p-Akt, p-mTOR, and p-S6. Both c-Met siRNA and MK-2206 could reverse inflammatory response. H. pylori CagA protein negatively regulates autophagy and promotes the inflammation in H. pylori infection, which is regulated by c-Met-PI3K/Akt-mTOR signaling pathway activation.

Fusobacterium nucleatum-Induced Impairment of Autophagic Flux Enhances the Expression of Proinflammatory Cytokines via ROS in Caco-2 Cells

Fusobacterium nucleatum (F. nucleatum) plays a critical role in gastrointestinal inflammation. However, the exact mechanism by which F. nucleatum contributes to inflammation is unclear. In the present study, it was revealed that F. nucleatum could induce the production of proinflammatory cytokines (IL-8, IL-1β and TNF-α) and reactive oxygen species (ROS) in Caco-2 colorectal) adenocarcinoma cells. Furthermore, ROS scavengers (NAC or Tiron) could decrease the production of proinflammatory cytokines during F. nucleatum infection. In addition, we observed that autophagy is impaired in Caco-2 cells after F. nucleatum infection. The production of proinflammatory cytokines and ROS induced by F. nucleatum was enhanced with either autophagy pharmacologic inhibitors (3-methyladenine, bafilomycin A1) or RNA interference in essential autophagy genes (ATG5 or ATG12) in Caco-2 cells. Taken together, these results indicate that F. nucleatum-induced impairment of autophagic flux enhances the expression of proinflammatory cytokines via ROS in Caco-2 Cells.

[The protective effect of alpha-2 adrenergic agonist on cranial nerve in rats with brain injury]

OBJECTIVE

To investigate the neuroprotective effect of α2 adrenergic agonist, dexmedetomidine on tumor necrosis factor α (TNF-α), interleukin-6 (IL-6) in brain tissue and serum S-100β protein level in traumatic brain injury rats.

METHODS

Seventy-two male Sprague-Dawley rats were randomly divided into sham operation group (group S), traumatic brain injury group (group C), and dexmedetomidine group (group D), 24 rats in each group; each of which was divided into 6, 12, 24 and 48 hours subgroup, 6 rats in each subgroup. Parietal brain contusion was produced by reformed Feeney method. The group S underwent sham operation without blunt force stroke; group D underwent blunt force stroke, then received loading dose of dexmedetomidine, 3 μg/kg with common jugular vein injection and continued infusion with 3 μg·kg(-1)·h(-1) for 2 hours. The total dosage of dexmedetomidine was 9 μg/kg with a volume of 4 ml; group C underwent 0.9% NaCl, 4 ml injection at the same time point with the same method. The S-100 protein activity in arteria cruralis serum was detected at the each time point by ELISA and TNF-α, IL-6 in the brain tissue were detected by ELISA.

RESULTS

There were no significant difference of TNF-α activity among time point of 6, 12, 24 and 48 h in group S ((2.07±0.06), (2.01±0.03), (2.11±0.05), and (2.08±0.04) pg/mg, F=1.147, P>0.05), no significant difference of IL-6 activity among the same time point ((4.03±0.06), (4.07±0.09), (4.06±0.04), and (4.55±0.09) pg/mg, F=1.176, P>0.05), and no significant difference of serum S-100β activity among the same time too ((0.37±0.07), (0.36±0.02), (0.35±0.06), and (0.39±0.11) μg/L, F=1.045, P>0.05). The above indexes in group C were higher than those in group S, and the above indexes in group D were higher than those in group S and lower than those in group C (all P<0.05).

CONCLUSION

Alpha-2 adrenergic agonist, dexmedetomidine could dramatically inhibit inflammatory reaction induced by traumatic brain injury in rats and protect brain tissue.

Shiga toxins induce autophagic cell death in intestinal epithelial cells via the endoplasmic reticulum stress pathway

Shiga toxins (Stxs) are a family of cytotoxic proteins that lead to the development of bloody diarrhea, hemolytic-uremic syndrome, and central nervous system complications caused by bacteria such as S. dysenteriae, E. coli O157:H7 and E. coli O104:H4. Increasing evidence indicates that macroautophagy (autophagy) is a key factor in the cell death induced by Stxs. However, the associated mechanisms are not yet clear. This study showed that Stx2 induces autophagic cell death in Caco-2 cells, a cultured line model of human enterocytes. Inhibition of autophagy using pharmacological inhibitors, such as 3-methyladenine and bafilomycin A1, or silencing of the autophagy genes ATG12 or BECN1 decreased the Stx2-induced death in Caco-2 cells. Furthermore, there were numerous instances of dilated endoplasmic reticulum (ER) in the Stx2-treated Caco-2 cells, and repression of ER stress due to the depletion of viable candidates of DDIT3 and NUPR1. These processes led to Stx2-induced autophagy and cell death. Finally, the data showed that the pseudokinase TRIB3-mediated DDIT3 expression and AKT1 dephosphorylation upon ER stress were triggered by Stx2. Thus, the data indicate that Stx2 causes autophagic cell death via the ER stress pathway in intestinal epithelial cells.

Role of Itk signalling in the interaction between influenza A virus and T-cells

Although the T-cell-mediated immune response to influenza virus has been studied extensively, little information is available on the direct interaction between influenza virus and T-cells that pertains to severe diseases in humans and animals. To address these issues, we utilized the BALB/c mouse model combined with primary T-cells infected with A/WSN/33 influenza virus to investigate whether influenza virus has an affinity for T-cells in vivo. We observed that small proportions of CD4(+) T-cells and CD8(+) T-cells in spleen and thymus expressed viral proteins in infected mice. A significant proportion of mouse primary T-cells displayed expression of α-2,6 sialic acid-linked influenza virus receptor and were infected directly by influenza A virus. These experiments reveal that there exists a population of T-cells that is susceptible to influenza A virus infection. Furthermore, we employed human Jurkat T-cells to investigate the virus-T-cell interaction, with particular emphasis on understanding whether Itk (interleukin-2-inducible T-cell kinase), a Tec family tyrosine kinase that regulates T-cell activation, is involved in virus infection of T-cells. Interestingly, influenza virus infection resulted in an increased recruitment of Itk to the plasma membrane and an increased level of phospholipase C-γ1 (PLC-γ1) phosphorylation, suggesting that Itk/PLC-γ1 signalling is activated by the virus infection. We demonstrated that depletion of Itk inhibited the replication of influenza A virus, whereas overexpression of Itk increased virus replication. These results indicate that Itk is required for efficient replication of influenza virus in infected T-cells.

Spinal neurokin3 receptors facilitate the nociceptive flexor reflex via a pathway involving nitric oxide

The present study examined the effects of intrathecal administration of neurokinin3 receptor agonists on the electrically-evoked nociceptive flexor reflex in decerebrate and spinalized adult rats. The reflex was evoked by stimulating the isolated sural nerve at an intensity that activates C fibers and was measured by recording the number of compound potentials in the ipsilateral hamstring muscles. Intrathecal senktide (1-30 nmol), a neurokinin3 receptor agonist, dose-dependently facilitated the reflex reaching a maximum effect of 230% of the baseline reflex at 10 nmol. SR 142801 (60 nmol), a non-peptide neurokinin3 receptor antagonist, blocked facilitation of the reflex induced by 10 nmol senktide, providing further support that the effect of senktide is mediated by neurokinin3 receptors. The intrathecal administration of senktide (10 nmol) did not alter the monosynaptic reflex elicited by stimulating the L5 dorsal root at an intensity that was at the threshold for activating A fibers. This indicates that the senktide-induced facilitation of the nociceptive flexor reflex was not at the level of the motor neuron. Pretreatment with N(G)-nitro-L-arginine methyl ester (30 nmol), a nitric oxide synthase inhibitor, attenuated the effect of senktide, indicating that facilitation of the reflex by senktide is also mediated by the production of nitric oxide. Data from the present work have shown that spinal neurokinin3 receptors facilitate the nociceptive flexor reflex through a pathway that involves interneurons and the production of NO. Therefore, neurokinin3 receptors are likely to be involved in enhancing nociceptive neurotransmission at the level of the spinal cord.

Spinal NK2 receptors contribute to the increased excitability of the nociceptive flexor reflex during persistent peripheral inflammation

The role of endogenous neurokinin A in changes in the excitability of spinal neurons during adjuvant-induced, peripheral inflammation was examined by determining the effect of a selective NK2 receptor antagonist, GR103537, on the nociceptive flexor reflex in rats. Intrathecal administration of GR103537 (1.4-14 nmol) dose-dependently attenuated the increased activity of the flexor reflex ipsilateral to the inflamed paw. The activity of GR103537 at NK2 receptors was confirmed by blockade of the facilitation of the reflex by neurokinin A but not substance P in normal rats. These results indicate that endogenous neurokinin A increases the excitability of spinal neurons during persistent peripheral inflammation.

Spinal NK1 receptors contribute to the increased excitability of the nociceptive flexor reflex during persistent peripheral inflammation

Hyperalgesia is a characteristic of inflammation and is mediated, in part, by an increase in the excitability of spinal neurons. Although substance P does not appear to mediate fast synaptic events that underlie nociception in the spinal cord, it may contribute to the hyperalgesia and increased excitability of spinal neurons during inflammation induced by complete Freund's adjuvant. We examined the role of endogenous substance P in changes in the excitability of spinal neurons during adjuvant-induced, peripheral inflammation by determining the effect of a selective NK1 receptor antagonist (RP67580) on the nociceptive flexor reflex in adult rats. Experiments were conducted 2 or 3 days after injection of adjuvant. Animals exhibited moderate thermal hyperalgesia at this time. The flexor reflex was evoked by electrical stimulation of the sural nerve and was recorded in the ipsilateral hamstring muscles. The flexor reflex ipsilateral to the inflamed hindpaw was enhanced approximately two-fold compared to the flexor reflex evoked in untreated animals as determined by the number of potentials and the duration of the reflex. The enhanced reflex in adjuvant-treated animals was most likely due to an increase in the excitability of spinal interneurons because short-latency activity in the hamstring muscles did not differ between untreated animals and adjuvant-treated animals following electrical stimulation of the L5 dorsal root or the nerve innervating the muscle with a stimulus that was 1.3-1.5 times the threshold for excitation of A-fibers. Intrathecal administration of RP67580 (2.3 and 6.8 nmol) attenuated the flexor reflex evoked in adjuvant-treated animals, but had no effect in untreated animals. Intravenous or intraplantar injection of RP67580 (6.8 nmol) did not affect the flexor reflex in adjuvant-treated animals indicating a spinal action of the drug following intrathecal administration. RP68651, the enantiomer of RP67580, was without effect at doses up to 6.8 nmol, indicating that the effects of comparable doses of RP67580 were due to an action of the drug at NK1 receptors. However, intrathecal administration of 23 nmol of both drugs attenuated the reflex in adjuvant-treated and control animals indicating that effects of RP67580 at this dose were not mediated entirely by its action at NK1 receptors. Overall, these data suggest that endogenous substance P has a role in the increased excitability of spinal interneurons observed during persistent inflammation and support the hypothesis that substance P released in the spinal cord contributes to the hyperalgesia that accompanies adjuvant-induced persistent, peripheral inflammation.