eV-Scale Sterile Neutrino Search Using Eight Years of Atmospheric Muon Neutrino Data from the IceCube Neutrino Observatory

The results of a 3+1 sterile neutrino search using eight years of data from the IceCube Neutrino Observatory are presented. A total of 305 735 muon neutrino events are analyzed in reconstructed energy-zenith space to test for signatures of a matter-enhanced oscillation that would occur given a sterile neutrino state with a mass-squared differences between 0.01 and 100  eV^{2}. The best-fit point is found to be at sin^{2}(2θ_{24})=0.10 and Δm_{41}^{2}=4.5  eV^{2}, which is consistent with the no sterile neutrino hypothesis with a p value of 8.0%.

Characteristics of the Diffuse Astrophysical Electron and Tau Neutrino Flux with Six Years of IceCube High Energy Cascade Data

We report on the first measurement of the astrophysical neutrino flux using particle showers (cascades) in IceCube data from 2010-2015. Assuming standard oscillations, the astrophysical neutrinos in this dedicated cascade sample are dominated (∼90%) by electron and tau flavors. The flux, observed in the sensitive energy range from 16 TeV to 2.6 PeV, is consistent with a single power-law model as expected from Fermi-type acceleration of high energy particles at astrophysical sources. We find the flux spectral index to be γ=2.53±0.07 and a flux normalization for each neutrino flavor of ϕ_{astro}=1.66_{-0.27}^{+0.25} at E_{0}=100  TeV, in agreement with IceCube's complementary muon neutrino results and with all-neutrino flavor fit results. In the measured energy range we reject spectral indices γ≤2.28 at ≥3σ significance level. Because of high neutrino energy resolution and low atmospheric neutrino backgrounds, this analysis provides the most detailed characterization of the neutrino flux at energies below ∼100  TeV compared to previous IceCube results. Results from fits assuming more complex neutrino flux models suggest a flux softening at high energies and a flux hardening at low energies (p value ≥0.06). The sizable and smooth flux measured below ∼100  TeV remains a puzzle. In order to not violate the isotropic diffuse gamma-ray background as measured by the Fermi Large Area Telescope, it suggests the existence of astrophysical neutrino sources characterized by dense environments which are opaque to gamma rays.

[Maintenance therapy following CD19 CAR-T treatment for relapsed B-cell acute lymphoblastic leukemia after allogeneic hematopoietic stem cell transplantation]

Objective: This study aimed to evaluate the maintenance therapy following an anti-CD19-CAR T-cell therapy for a B-cell acute lymphoblastic leukemia (ALL) patient who relapsed after allogeneic hematopoietic cell transplantation (allo-HSCT) and investigate the effect of donor stem cells and donor T lymphocyte infusion on the amplification of CD19 CAR-T cells. Methods: One refractory B-ALL patient relapsed after murine CD19 CAR-T cell therapy followed by a sibling allo-HSCT. He underwent a humanized CD19 CAR-T cell therapy followed by donor stem cell and donor T lymphocytes infusions as maintenance therapy in our hospital. The level of cytokines, the proportion of CD19 CAR-T cell, the level of CAR19 DNA expression in the peripheral blood, and the proportion of leukemia cells and donor chimerism in the bone marrow were detected. Correspondingly, T lymphocytes from the C57 spleen were separated to modify the CD19 CAR lentivirus and refused into C57 mice, and after 14 days, the B lymphocytes from C57 mice were separated and refused into the same C57 mice. The CD19 CAR T cells, B cells, and CD19 CAR gene counts in the peripheral blood were evaluated at different time points. Results: ①The patient achieved a complete response (CR) 14 days after a humanized CD19 CAR-T therapy with grade 1 cytokine release syndrome (CRS) and restored a donor chimerism to 99.76%. ② Following the remission from humanized CD19 CAR-T therapy, the patient received a maintenance therapy of donor stem cell infusion. Mild graft-versus-host disease (GVHD) manifested 24 days after infusion with an increased proportion of CD19 CAR-T cells and an increased level of CAR19 DNA expression in the peripheral blood. It fell with the remission of GVHD. The patient maintained CR and 99.69% donor chimerism during this period. ③ Throughout the subsequent donor T lymphocytes maintenance therapy, mild GVHD surfaced12 days after infusion without an increased proportion of CD19 CAR-T cells and an increased level of CAR19 DNA expression in the peripheral blood. The patient maintained CR and 99.87% donor chimerism during this period. ④ In vivo experiments on C57 mice confirmed that the proportion of CD19 CAR-T cells and the level of CAR19 DNA expression were upregulated in mice following CAR-T cell infusion, accompanied by depletion of CD19(+) B lymphocyte. After infusion of CD19(+) B lymphocyte cells, an increased proportion of CD19 CAR-T cells and an increased level of CAR19 DNA expression in the peripheral blood were observed again. Conclusions: The infusion of donor stem cells and donor T lymphocytes could be used as a maintenance treatment after CD19 CAR-T cell therapy for B-ALL patients who relapsed after allo-HSCT. Infusion of donor stem cells induced an increased proportion of CD19 CAR-T cells and an increased level of CAR19 DNA expression with the occurrence of GVHD. It might lead to further elimination of minimal residual disease.

Post-translational Succinylation of Mycobacterium tuberculosis Enoyl-CoA Hydratase EchA19 Slows Catalytic Hydration of Cholesterol Catabolite 3-Oxo-chol-4,22-diene-24-oyl-CoA

Cholesterol is a major carbon source for Mycobacterium tuberculosis (Mtb) during infection, and cholesterol utilization plays a significant role in persistence and virulence within host macrophages. Elucidating the mechanism by which cholesterol is degraded may permit the identification of new therapeutic targets. Here, we characterized EchA19 (Rv3516), an enoyl-CoA hydratase involved in cholesterol side-chain catabolism. Steady-state kinetics assays demonstrated that EchA19 preferentially hydrates cholesterol enoyl-CoA metabolite 3-oxo-chol-4,22-diene-24-oyl-CoA, an intermediate of side-chain β-oxidation. In addition, succinyl-CoA, a downstream catabolite of propionyl-CoA that forms during cholesterol degradation, covalently modifies targeted mycobacterial proteins, including EchA19. Inspection of a 1.9 Å resolution X-ray crystallography structure of Mtb EchA19 suggests that succinylation of Lys132 and Lys139 may perturb enzymatic activity by modifying the entrance to the substrate binding site. Treatment of EchA19 with succinyl-CoA revealed that these two residues are hotspots for succinylation. Replacement of these specific lysine residues with negatively charged glutamate reduced the rate of catalytic hydration of 3-oxo-chol-4,22-diene-24-oyl-CoA by EchA19, as does succinylation of EchA19. Our findings suggest that succinylation is a negative feedback regulator of cholesterol metabolism, thereby adding another layer of complexity to Mtb physiology in the host. These regulatory pathways are potential noncatabolic targets for antimicrobial drugs.

Environmental enrichment prevents chronic stress-induced brain-gut axis dysfunction through a GR-mediated mechanism in the central nucleus of the amygdala

BACKGROUND

Cognitive behavioral therapy (CBT) improves quality of life of patients with irritable bowel syndrome (IBS), a disorder characterized by chronic visceral pain and abnormal bowel habits. Whether CBT can actually improve visceral pain in IBS patients is still unknown. The aim of this study is to evaluate whether environment enrichment (EE), the animal analog of CBT, can prevent stress-induced viscero-somatic hypersensitivity through changes in glucocorticoid receptor (GR) signaling within the central nucleus of the amygdala (CeA).

METHODS

Rats were housed in either standard housing (SH) or EE for 7 days before and during daily water avoidance stress (WAS) exposure (1-h/d for 7 days). In the first cohort, visceral and somatic sensitivity were assessed via visceromotor response to colorectal distention and von Frey Anesthesiometer 24 hous and 21 days after WAS. In another cohort, the CeA was isolated for GR mRNA quantification.

KEY RESULTS

Environment enrichment for 7 days before and during the 7 days of WAS persistently attenuated visceral and somatic hypersensitivity when compared to rats placed in SH. Environment enrichment exposure also prevented the WAS-induced decrease in GR expression in the CeA.

CONCLUSION & INFERENCES

Pre-exposure to short-term EE prevents the stress-induced downregulation of GR, and inhibits visceral and somatic hypersensitivity induced by chronic stress. These results suggest that a positive environment can ameliorate stress-induced pathology and provide a non-pharmacological therapeutic option for disorders such as IBS.

Self-made Salmonella Pullorum agglutination antigen development and its potential practical application

Pullorum disease caused by Salmonella Pullorum is one of the most important infectious diseases in the poultry industry worldwide, which leads to serious economic losses in many developing countries because of its high mortality rate in young chicks. The traditional slide agglutination test with low cost, fast reaction, and on-site detection has been widely used in the diagnosis of Pullorum disease. However, in practice, the test performance is with the disadvantages of false positive results and unstable detection results. In this paper, we developed self-made agglutination antigens prepared by local isolates in the poultry farm and compare the detection performance with commercial agglutination antigens (China Institute of Veterinary Drug Control) and Group D Salmonella ELISA kit (BioChek UK Ltd). The results of detecting 200 serum samples indicated that the consistency of commercial agglutination antigen detecting in 2 times was only 79.5%. Using the ELISA kit as the reference method, the commercial agglutination antigen detecting results of the Kappa test were only moderately consistent (0.58 ∼ 0.59). Meanwhile, positive and total coincidence rates of the self-made agglutination antigen test with more reliable repeat could reach 97.4 and 88%, respectively, and the result of Kappa test was highly consistent (0.75). The Receiver Operating Characteristic curve analysis clarified that the area under the receiver-operating-characteristic curve values of self-made and commercial agglutination antigen tests could reach 0.861 and 0.804, respectively. These results were coincident when detecting known positive serum from the infected chickens. It's worth mentioning that the visible positive reaction of self-made agglutination antigen test appeared faster and stronger than commercial antigen test. In conclusion, self-made Salmonella Pullorum agglutination antigen developed in this study was much better than commercial agglutination antigen and is expected to be a valuable tool in the diagnosis of the epidemiology of Salmonella Pullorum.

[Etiology and clinical features of primary adrenal insufficiency]

Objective: To summarize the etiology of primary adrenal insufficiency (PAI) and analyze its clinical features. Methods: A retrospective analysis was performed in the Department of Endocrinology, Peking Union Medical College Hospital from October 1981 to June 2019. Patients with PAI as the first symptom were enrolled. The etiology of PAI was analyzed and the clinical characteristics was also summarized. Results: A total of 131 patients with PAI were enrolled, including 87 males and 44 females (57 adolescents, and 74 adults). The age ranged from 0 to 73 years. The primary cause of PAI in adolescents was genetic defects (52.6%, 30/57), in which congenital adrenal dysplasia caused by DAX1 gene deficiency accounted for 50.0% (15/30), followed by autoimmunity (22.8%, 13/57). The primary cause of adult PAI was infection (58.1%, 43/74), of which tuberculosis accounted for the majority (93.0%, 40/43), and autoimmune adrenalitis accounted for 19.0% (14/74). Compared with the tuberculosis group, female patients were more common, and the onset age was younger, the plasma cortisol, serum sodium, fasting blood glucose, creatinine and aldosterone were lower (all P<0.05), and serum potassium and renin levels were higher in the autoimmune adrenalitis group (both P<0.05). Conclusions: In the current study, the proportion of PAI caused by infection in the adult group was higher than that in the adolescent group. The most common cause of adult PAI was tuberculosis infection. The most common cause of childhood PAI was genetic defects. Autoimmune damage to the adrenal glands may be more severe than tuberculosis infection.

[Analysis of the efficacy and influencing factors of nilotinib or dasatinib as second- or third-line treatment in patients with chronic myeloid leukemia in the chronic phase and accelerated phase]

目的

分析二代酪氨酸激酶抑制剂（TKI）尼洛替尼和达沙替尼作为二三线药物治疗慢性髓性白血病（CML）慢性期（CP）和加速期（AP）患者的治疗反应和预后，以及相关影响因素。

方法

回顾性分析2008年1月至2018年11月北京大学人民医院收治的一二线TKI治疗失败并接受尼洛替尼或达沙替尼作为二三线治疗的CML-CP和AP患者资料。

结果

共收集183例尼洛替尼和达沙替尼作为二线治疗和43例尼洛替尼和达沙替尼作为三线治疗的CML-CP或AP患者。二线TKI治疗患者中，中位随访21（1~135）个月，完全血液学反应（CHR）率为80.4%，完全细胞遗传学反应（CCyR）率为56.3%，主要分子学反应（MMR）率为38.3%，3年疾病无进展生存（PFS）和总生存(OS)率分别为78.7%和93.1%。二线TKI治疗中，Sokal积分为高危、女性、一线TKI治疗期间获得最佳反应<CHR、诊断CML距转换二线TKI治疗时间≥18个月、二线TKI治疗前为AP/血液学耐药、二线TKI治疗前未检测出BCR-ABL特殊突变、二线治疗中发生≥3级血液学不良反应是获得细胞遗传学或分子学反应或PFS的不利影响因素。三线TKI治疗患者中，中位随访6（3~129）个月，CHR率为95.7%，CCyR率为29.3%，MMR率为18.6%，2年PFS和OS率分别为66.8%和93.8%。三线TKI治疗中，诊断距一线TKI治疗时间≥6个月、二线TKI治疗期间未获得细胞遗传学反应、诊断距三线TKI治疗时间≥60个月或转换治疗前疾病分期为AP患者获得治疗反应的比例显著降低或预后不良。

结论

尼洛替尼和达沙替尼作为二三线药物可以有效治疗TKI耐药的CML-CP和AP患者，前次TKI治疗期间获得的最佳反应、换药前疾病分期和本次TKI治疗中是否发生≥3级血液学不良反应等因素影响治疗结果。

IpdE1-IpdE2 Is a Heterotetrameric Acyl Coenzyme A Dehydrogenase That Is Widely Distributed in Steroid-Degrading Bacteria

Steroid-degrading bacteria, including Mycobacterium tuberculosis (Mtb), utilize an architecturally distinct subfamily of acyl coenzyme A dehydrogenases (ACADs) for steroid catabolism. These ACADs are α₂β₂ heterotetramers that are usually encoded by adjacent fadE-like genes. In mycobacteria, ipdE1 and ipdE2 (formerly fadE30 and fadE33) occur in divergently transcribed operons associated with the catabolism of 3aα-H-4α(3'-propanoate)-7aβ-methylhexahydro-1,5-indanedione (HIP), a steroid metabolite. In Mycobacterium smegmatis, ΔipdE1 and ΔipdE2 mutants had similar phenotypes, showing impaired growth on cholesterol and accumulating 5-OH HIP in the culture supernatant. Bioinformatic analyses revealed that IpdE1 and IpdE2 share many of the features of the α- and β-subunits, respectively, of heterotetrameric ACADs that are encoded by adjacent genes in many steroid-degrading proteobacteria. When coproduced in a rhodococcal strain, IpdE1 and IpdE2 of Mtb formed a complex that catalyzed the dehydrogenation of 5OH-HIP coenzyme A (5OH-HIP-CoA) to 5OH-3aα-H-4α(3'-prop-1-enoate)-7aβ-methylhexa-hydro-1,5-indanedione coenzyme A ((E)-5OH-HIPE-CoA). This corresponds to the initial step in the pathway that leads to degradation of steroid C and D rings via β-oxidation. Small-angle X-ray scattering revealed that the IpdE1-IpdE2 complex was an α₂β₂ heterotetramer typical of other ACADs involved in steroid catabolism. These results provide insight into an important class of steroid catabolic enzymes and a potential virulence determinant in Mtb.

[Analysis on poor efficacy factors in the treatment of recurrent/refractory B-cell lymphoma with CD19 CAR-T cells]

Objective: To investigate the factors influencing the efficacy of CD19 chimeric antigen receptor T (CAR-T) cells in the treatment of patients with relapsed refractory B cell lymphoma and to provide evidence for further improvement of CAR-T efficacy. Methods: A total of 34 patients with relapsed and refractory B-cell lymphoma were recruited from the Department of Hematology of Tianjin First Central Hospital from February 2017 to January 2019. All patients received CD19 CAR-T cell therapy. These patients were evaluated for efficacy, factors with poor efficacyand adverse effects. Results: The overall response rate was 58.8% (20/34) and the complete remission rate was 41.2% (14/34) after infusion of CD19 CAR-T cells in 34 patients with relapsed refractory B cell lymphoma. According to the efficacy of CAR-T cells, patients were divided into two groups, 20 in the effective group and 14 in the poorly effective group. The median am ount of CD19 CAR-T cell infusions in these two groups were 8.6 (5.0-12.7)×10(6)/kg and 9.7 (5.8-15.0) × 10(6)/kg, respectively, and the difference was not statistically significant (P=0.654). The percentage of CD19 CAR-T cells in the effective group and the poorly treated group was 10.28% (3.92%-44.16%) and 4.05% (0.92%-28.63%), respectively.The effective group had a higher proportion of CAR-T cells than the poorly treated group, but the difference was not statistically significant (P=0.371).The presence of massive mass was an unfavorable factor affecting the efficacy of CD19 CAR-T cells and the difference was statistically significant (P=0.001). Logistic regression multivariate analysis showed that the characteristics of massive tumors were still independent prognostic factors for poor efficacy of CD19 CAR-T cells (P=0.005, OR=0.039). Of all 34 patients, there were 70.6% (24/34) who showed varying degrees of adverse reactions after the infusion of CD19 CAR-T cells, mainly cytokines release syndrome (CRS). The median time of occurrence of fever was on the third day after infusion (0-11th) day. 16 patients were with grade 1 CRS, 7 with grade 2, and 1 with grade 3. After glucocorticoids and support treatment, they all showed improvements. Conclusions: CD19 CAR-T cell therapy has achieved a certain effect in CD19(+)B cell lymphoma, but has poor efficacy on some patients. Large mass tumors may be an adverse factors to CAR-T cell treatment.

Time-Integrated Neutrino Source Searches with 10 Years of IceCube Data

This Letter presents the results from pointlike neutrino source searches using ten years of IceCube data collected between April 6, 2008 and July 10, 2018. We evaluate the significance of an astrophysical signal from a pointlike source looking for an excess of clustered neutrino events with energies typically above ∼1  TeV among the background of atmospheric muons and neutrinos. We perform a full-sky scan, a search within a selected source catalog, a catalog population study, and three stacked Galactic catalog searches. The most significant point in the northern hemisphere from scanning the sky is coincident with the Seyfert II galaxy NGC 1068, which was included in the source catalog search. The excess at the coordinates of NGC 1068 is inconsistent with background expectations at the level of 2.9σ after accounting for statistical trials from the entire catalog. The combination of this result along with excesses observed at the coordinates of three other sources, including TXS 0506+056, suggests that, collectively, correlations with sources in the northern catalog are inconsistent with background at 3.3σ significance. The southern catalog is consistent with background. These results, all based on searches for a cumulative neutrino signal integrated over the 10 years of available data, motivate further study of these and similar sources, including time-dependent analyses, multimessenger correlations, and the possibility of stronger evidence with coming upgrades to the detector.

Autologous oxygen release nano bionic scaffold composite miR-106a induced BMSCs enhances osteoblast conversion and promotes bone repair through regulating BMP-2

OBJECTIVE

Suitable seed cells and selection of bioactive scaffold materials are the main research contents of bone tissue engineering. It was showed that autologous oxygen release nano bionic scaffold could promote the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). The role of microRNA-106a (miR-106a) in regulating BMSCs differentiation has not been reported. We intend to investigate the role of autologous oxygen release nano bionic scaffold composite miR-106a in inducing BMSCs constructing tissue engineering bone.

MATERIALS AND METHODS

Rat BMSCs were isolated and transfected by using miR-106a scramble or miR-106a inhibitor. Healthy male Sprague-Dawly (SD) rats were randomly divided into three groups, including bone fracture group established as rat tibial fracture model, negative control group implanted by autologous oxygen release nano bionic scaffold composite miR-106a scramble BMSCs, and miR-106a inhibitor group implanted by autologous oxygen release nano bionic scaffold composite miR-106a inhibitor BMSCs. Callus growth was observed. Alkaline phosphatase (ALP) activity was detected. Bone morphogenetic protein 2 (BMP-2) expression was tested by Real-time PCR (RT-PCR) and Western blot assay. Collagen II production was determined by RT-PCR.

RESULTS

Autologous oxygen release nano bionic scaffold composite BMSCs significantly increased local bone mineral density, promoted callus healing, facilitated ALP secretion, elevated collagen II expression, and up-regulated BMP-2 mRNA and protein levels compared with fracture group (p<0.05). Autologous oxygen release nano bionic scaffold composite miR-106a induced BMSCs exhibited more significant effect on bone repair (p<0.05).

CONCLUSIONS

Autologous oxygen release nano bionic scaffold composite miR-106a induced BMSCs enhanced osteoblast conversion and promoted bone repair through regulating BMP-2.

Mycobacterium tuberculosis Exploits a Heterohexameric Enoyl-CoA Hydratase Retro-Aldolase Complex for Cholesterol Catabolism

Cholesterol catabolism plays an important role in Mycobacterium tuberculosis's (Mtb's) survival and persistence in the host. Mtb exploits three β-oxidation cycles to fully degrade the side chain of cholesterol. Five cistronic genes in a single operon encode three enzymes, 3-oxo-4-pregnene-20-carboxyl-CoA dehydrogenase (ChsE1-ChsE2), 3-oxo-4,17-pregnadiene-20-carboxyl-CoA hydratase (ChsH1-ChsH2), and 17-hydroxy-3-oxo-4-pregnene-20-carboxyl-CoA retro-aldolase (Ltp2), to perform the last β-oxidation cycle in this pathway. Among these three enzymes, ChsH1-ChsH2 and Ltp2 form a protein complex that is required for the catalysis of carbon-carbon bond cleavage. In this work, we report the structure of the full length ChsH1-ChsH2-Ltp2 complex based on small-angle X-ray scattering and single-particle electron microscopy data. Mutagenesis experiments confirm the requirement for Ltp2 to catalyze the retro-aldol reaction. The structure illustrates how acyl transfer between enzymes may occur. Each protomer of the ChsH1-ChsH2-Ltp2 complex contains three protein components: a chain of ChsH1, a chain of ChsH2, and a chain of Ltp2. Two protomers dimerize at the interface of Ltp2 to form a heterohexameric structure. This unique heterohexameric structure of the ChsH1-ChsH2-Ltp2 complex provides entry to further understand the mechanism of cholesterol catabolism in Mtb.

[Philadelphia chromosome-negative myeloid neoplasms in patients with Philadelphia chromosome-positive chronic myeloid leukemia during tyrosine kinase inhibtor-therapy]

Objective: To compare the clinical features between the 2 cohorts developing myelodysplastic syndrome or acute myeIogenous Ieukemia in Philadelphia chromosome-negative cells (Ph(-) MDS/AML) and maintaining disease stable in the patients with Philadelphia chromosome-positive chronic myeloid Ieukemia (Ph(+) CML) who had clonal chromosomal abnormalities in Philadelphia chromosome-negative metaphases (CCA/Ph(-)) during tyrosine kinase inhibtor (TKI) - therapy. Methods: We retrospectively analyzed Ph(+) CML patients who developed CCA/Ph(-) during TKI-therapy from May 2001 to December 2017. Results: Data of CCA/Ph(-) 63 patients, including 7 progressing to Ph(-) MDS/AML and 56 remaining disease stable were collected. Compared with those with stable disease, patients with Ph(-)MDS/AML had lower hemoglobin (P=0.007) and platelet (P=0.006) counts, and higher proportion of peripheral blasts (P<0.001) when the first time CCA/Ph(-) was detected, and more mosonomy 7 abnormality (5/7, 71.4%) when MDS or AML was diagnosed; meanwhile, trisomy 8 (32/56, 57.1%) was more common in those with stable disease. Outcome of the patients with Ph(-) MDS/AML were poor. However, most of those with CCA/Ph(-) and stable disease had optimal response on TKI-therapy. Conclusions: A few patients with Ph(+) CML developed CCA/Ph(-) during TKI-therapy, most of them had stable disease, but very few patients developed Ph(-) MDS/AML with more common occurrence of monosomy 7 or unknown cytopenia. Our data suggested the significance of monitoring of peripheral blood smear, bone marrow morphology and cytogenetic analysis once monosomy 7 or unknown cytopenia occurred.

Mce3R Stress-Resistance Pathway Is Vulnerable to Small-Molecule Targeting That Improves Tuberculosis Drug Activities

One-third of the world’s population carries Mycobacterium tuberculosis (Mtb), the infectious agent that causes tuberculosis (TB), and every 17 s someone dies of TB. After infection, Mtb can live dormant for decades in a granuloma structure arising from the host immune response, and cholesterol is important for this persistence of Mtb. Current treatments require long-duration drug regimens with many associated toxicities, which are compounded by the high doses required. We phenotypically screened 35 6-azasteroid analogues against Mtb and found that, at low micromolar concentrations, a subset of the analogues sensitized Mtb to multiple TB drugs. Two analogues were selected for further study to characterize the bactericidal activity of bedaquiline and isoniazid under normoxic and low-oxygen conditions. These two 6-azasteroids showed strong synergy with bedaquiline (fractional inhibitory concentration index = 0.21, bedaquiline minimal inhibitory concentration = 16 nM at 1 μM 6-azasteroid). The rate at which spontaneous resistance to one of the 6-azasteroids arose in the presence of bedaquiline was approximately 10^–9, and the 6-azasteroid-resistant mutants retained their isoniazid and bedaquiline sensitivity. Genes in the cholesterol-regulated Mce3R regulon were required for 6-azasteroid activity, whereas genes in the cholesterol catabolism pathway were not. Expression of a subset of Mce3R genes was down-regulated upon 6-azasteroid treatment. The Mce3R regulon is implicated in stress resistance and is absent in saprophytic mycobacteria. This regulon encodes a cholesterol-regulated stress-resistance pathway that we conclude is important for pathogenesis and contributes to drug tolerance, and this pathway is vulnerable to small-molecule targeting in live mycobacteria.

[A comparative study of induction chemotherapy with or without autologous hematopoietic stem cell transplantation in the treatment of newly diagnosed young medium/high risk diffuse large B cell lymphoma patients]

Objective: To compare the efficacy of induction chemotherapy with or without autologous hematopoietic stem cell transplantation (auto-HSCT) for newly diagnosed young diffuse large B cell lymphoma (DLBCL) patients. Methods: The retrospective study was performed in 90 cases of young patients (≤60 years) with newly diagnosed DLBCL and an age-adjusted International Prognostic Index (aa-IPI) score of 2 or 3. All of them were treated with R-CHOP (32 cases, rituximab combined with CHOP), dose-intensive regimens (DA-EPOCH, Hyper CVAD/MA or ESHAP) combined with or without rituximab (25 cases), and consolidated with up-front auto-HSCT (33 cases), respectively. The efficacy and the potential predictors were evaluated. Results: ①The median age of 90 patients was 43 (18-60) years old. The median follow-up time was 42 (3-110) months. ②The 5-year progression-free survival (PFS) for R-CHOP group, dose-intensive chemotherapy group and auto-HSCT group were (33.5±10.7) %, (55.3±10.1) % and (65.8±13.6) % (P=0.012), the 5-year overall survival (OS) were (49.7±9.0) %, (61.6±10.2) % and (78.6±7.8) % (P=0.035), respectively. There was no significant difference in 5-years PFS and OS between the R-CHOP group and dose-intensive chemotherapy group (P=0.519, P=0.437) compared with that of the dose-intensive chemotherapy group, auto-HSCT group has higher 5-year PFS (P=0.042). ③ When stratified with IPI score, the high-risk group treated with auto-HSCT (26 cases) showed similar 5-years PFS and 5-years OS to those in the low-risk group with chemotherapy alone (12 cases were in R-CHOP group and 8 cases were in dose-intensive chemotherapy group) [5-years PFS were (62.3 ±14.3)%, (58.3 ±18.6)% and (51.4±18.7)%, respectively, P=0.686; 5-years OS were (69.2±13.9)%, (62.5±15.5)% and (58.3±18.6)%, respectively, P=0.592]. ④However, the high-risk group treated with auto-HSCT (26 cases) showed superior 5-years PFS (P=0.002) and 5-years OS (P=0.019) compared to the high-risk group with chemotherapy alone (20 cases were in R-CHOP group and 17 cases were in dose-intensive chemotherapy group) [5-years PFS were (62.3±14.3)%, (41.1±13.5)% and (21.9±11.6)%, respectively; 5-years OS were (69.2±13.9)%, (51.5%±14.0)% and (35.4±13.6)%, respectively]. ⑤In the univariate analysis, as a whole, patients diagnosed with GCB subtype had higher 3-years PFS (P=0.022) and 3-years OS (P=0.037) compared to non-GCB subtype patients; in subgroup analysis, patients diagnosed with GCB subtype had higher 3-years PFS and 3-years OS compared to non-GCB subtype both in R-CHOP group (P=0.030, P=0.041) and dose-intensive chemotherapy group (P=0.044, P=0.047), but not in auto-HSCT group (P=0.199, P=0.093). ⑥In the multivariate analysis, different molecular classification (GCB/non-GCB) was an independent predictor for PFS and OS both in R-CHOP group [HR=0.274 (95% CI 0.094-0.800), P=0.018; HR=0.408 (95% CI 0.164-1.015), P=0.045] and dose-intensive chemotherapy group [HR=0.423 (95% CI 0.043-1.152), P=0.048; HR=5.758 (95% CI 0.882-6.592), P=0.035]. However, there was no significant difference in PFS and OS for auto-HSCT group between GCB/non-GCB patients. Conclusion: Induction chemotherapy followed by up-front auto-HSCT has significant effect on efficacy for young and untreated patients with high risk DLBCL. Combined with induction chemotherapy followed by up-front auto-HSCT could improve the prognosis of non-GCB patients.

[Ibrutinib inhibits mesenchymal stem cells-mediated drug resistance in diffuse large B-cell lymphoma]

目的

探讨依布替尼克服弥漫大B细胞淋巴瘤（DLBCL）细胞耐药的机制。

方法

①体外实验：以DLBCL细胞系SUDHL10细胞（GCB亚型）、HBL-1（ABC亚型）以及8例DLBCL患者原代细胞为研究对象，与正常人骨髓基质细胞（MSC）共培养后，显微镜下计数向MSC趋化迁移及与MSC黏附的DLBCL细胞数，ELISA法检测MSC的CXCL12表达水平，流式细胞术检测DLBCL细胞的CXCR4表达水平；以携带有CXCR4的慢病毒转染HBL-1细胞，米托蒽醌、依布替尼处理后与MSC共培养，流式细胞术检测细胞凋亡水平；倒置显微镜下观察HBL-1细胞集落形成情况。②体内实验：以HBL-1细胞构建的NOD/SCID肿瘤模型小鼠为研究对象，观察依布替尼治疗后肿瘤体积变化。

结果

①依布替尼处理后，DLBCL细胞向MSC的迁移数和与MSC的黏附比例明显降低（P值均<0.05），并呈剂量依赖性。②与依布替尼处理前比较，处理后MSC的CXCL12表达水平降低（SUDHL10细胞：660 pg/ml对1 400 pg/ml，P=0.004；HBL-1细胞：720 pg/ml对1 490 pg/ml，P=0.018；DLBCL原代细胞：850 pg/ml对1 450 pg/ml，P=0.004），DLBCL细胞的CXCR4表达水平降低（P值均<0.05）。③共培养时，对照组、米托蒽醌组、依布替尼组、米托蒽醌组+依布替尼组的HBL-1细胞凋亡比例分别为15.1%、17.5%、23.5%、58.7%，转染过表达CXCR4后，HBL-1细胞凋亡比例分别为14.2%、16.1%、22.5%、38.3%，共培养联合用药组HBL-1细胞凋亡比例高于单药培养组，差异均有统计学意义（P值均<0.05）。④对照组、MSC组、依布替尼组、MSC组+依布替尼组集落数分别为113±5、205±4、62±9、123±3（每孔2.5×10³），模型小鼠皮下肿瘤体积分别为6 500、17 000、4 000、10 000 mm³，依布替尼处理后较处理前集落数和肿瘤体积明显减少，差异均有统计学意义（P值均<0.05）。

结论

依布替尼靶向作用于CXCL12/CXCR4轴，抑制CXCR4表达从而克服MSC介导的耐药作用，并且能够在体内外抑制MSC促淋巴瘤细胞集落形成的作用。为依布替尼治疗复发耐药DLBCL提供了理论依据。

Constraints on Minute-Scale Transient Astrophysical Neutrino Sources

High-energy neutrino emission has been predicted for several short-lived astrophysical transients including gamma-ray bursts (GRBs), core-collapse supernovae with choked jets, and neutron star mergers. IceCube's optical and x-ray follow-up program searches for such transient sources by looking for two or more muon neutrino candidates in directional coincidence and arriving within 100 s. The measured rate of neutrino alerts is consistent with the expected rate of chance coincidences of atmospheric background events and no likely electromagnetic counterparts have been identified in Swift follow-up observations. Here, we calculate generic bounds on the neutrino flux of short-lived transient sources. Assuming an E^{-2.5} neutrino spectrum, we find that the neutrino flux of rare sources, like long gamma-ray bursts, is constrained to <5% of the detected astrophysical flux and the energy released in neutrinos (100 GeV to 10 PeV) by a median bright GRB-like source is <10^{52.5}  erg. For a harder E^{-2.13} neutrino spectrum up to 30% of the flux could be produced by GRBs and the allowed median source energy is <10^{52}  erg. A hypothetical population of transient sources has to be more common than 10^{-5}  Mpc^{-3}  yr^{-1} (5×10^{-8}  Mpc^{-3}  yr^{-1} for the E^{-2.13} spectrum) to account for the complete astrophysical neutrino flux.

[Vertigo and sensorineural hearing loss due to syphilis: differential diagnosis and treatment]

Objective:To analyze the etiology of repeatedly attacks of intractable vertigo and some types of sensorineural deafness whose clinical manifestation were not in conformity with the known spectrum diseases，and explore the screening method to prevent missed diagnosis or misdiagnosis, then provide references for clinical diagnosis and treatment for rare etiology. Method:The authors retrospectively analyzed the clinical manifestations, diagnosis, treatment and prognosis from 4 cases of vertigo sufferers and 2 cases of hearing impairment sufferers whose serological tests were positive for syphilis. All these 6 cases were treated with large doses of penicillin aqueous solutions (24 million U/d), multi-times intravenous infusion, the course of the treatment was 14 d. Result:The clinical manifestations of these 6 patients were lack of characteristic, as well as the results of hearing and vestibular function, imaging diagnosis. Positive syphilis detection of serology and cerebrospinal fluid tests were the main diagnostic basis. After anti-syphilis treatment, 5 cases got satisfied clinical symptoms improvement, 1 case suffered from low-tone sensorineural hearing loss, whose hearing fluctuated recurrently. Conclusion:Syphilis infection may damage the Ⅷ cranial nerve and then lead to vertigo and hearing loss, through chronic syphilitic osteitis of temporal bone, atrophy of organ of corti, osteolytic lesion surrounding the endolymphatic duct, and neurosyphilis. For patients presented with intractable vertigo, and those whose clinical manifestations are not in conformity with the known diseases of unilateral ear or bilateral ears rapidly progressive deafness, syphilis serology screening and validation tests are recommended in case of missed diagnosis or misdiagnosis.