Structural changes of rice starch-anthocyanins complexes (V-type) and its impact on gut microbiotas and potential metabolic pathways during in vitro fermentation

This study explored the differences in the in vitro fermentation properties of rice starch (RS) and rice starch-anthocyanins complexes (RS-A). Structural characterization suggested that RS and RS-A complexes showed a V-type crystalline structure. The degree of order (DO) and degree of double helix (DD) values of RS and RS-A complexes were enhanced after fermentation. Moreover, the RS-A complexes could improve the relative abundance of Bacteroidetes, Ruminococcaceae, and up-regulate gut microbiota diversity to maintain gut homeostasis. Relative abundance of potential metabolic pathways, such as energy metabolism, digestion system, and carbohydrate degradation overexpressed in the presence of RS-A complexes. The results demonstrated that the RS-A complexes had slower fermentation rates contributing to the transport of the formed short-chain fatty acid (SCFA) to the end of the colon and that the crystallinity might be a factor influencing the utilization of the starch matrix by the gut microbiota for SCFA formation.

A comparative study on the gel and structural characteristics of starch from three rice varieties when combined with Mesona chinensis polysaccharides

Mesona chinensis polysaccharide (MCP) has excellent gel-forming characteristic, previous studies showed that MCP could affect the gelling and structural properties of rice starch, but the effect of MCP on rice starch from different types is not clarified. In this study, the effects of MCP on the pasting, rheological, and structural characteristics of glutinous rice starch (GRS), japonica rice starch (JRS), and indica rice starch (IRS) were investigated. The results showed that GRS-MCP has the best viscosity, its peak and final viscosities are higher than JRS-MCP and IRS-MCP. The gel network structure was enhanced by MCP in the order of IRS > JRS > GRS, which was reflected by greater elasticity, higher gel strength and hardness, and less free water in JRS-MCP and IRS-MCP. MCP also enhanced the ordered structure and thermal stability of the three starch gels, which is conducive to their application in the market. These findings provide new theoretical insights to produce rice starch-based foods.

Cultivation of microalgae-bacteria consortium by waste gas-waste water to achieve CO2 fixation, wastewater purification and bioproducts production

The cultivation of microalgae and microalgae-bacteria consortia provide a potential efficient strategy to fix CO2 from waste gas, treat wastewater and produce value-added products subsequently. This paper reviews recent developments in CO2 fixation and wastewater treatment by single microalgae, mixed microalgae and microalgae-bacteria consortia, as well as compares and summarizes the differences in utilizing different microorganisms from different aspects. Compared to monoculture of microalgae, a mixed microalgae and microalgae-bacteria consortium may mitigate environmental risk, obtain high biomass, and improve the efficiency of nutrient removal. The applied microalgae include Chlorella sp., Scenedesmus sp., Pediastrum sp., and Phormidium sp. among others, and most strains belong to Chlorophyta and Cyanophyta. The bacteria in microalgae-bacteria consortia are mainly from activated sludge and specific sewage sources. Bioengineer in CBB cycle in microalgae cells provide effective strategy to achieve improvement of CO2 fixation or a high yield of high-value products. The mechanisms of CO2 fixation and nutrient removal by different microbial systems are also explored and concluded, the importance of microalgae in the technology is proven. After cultivation, microalgae biomass can be harvested through physical, chemical, biological and magnetic separation methods and used to produce high-value by-products, such as biofuel, feed, food, biochar, fertilizer, and pharmaceutical bio-compounds. Although this technology has brought many benefits, some challenging obstacles and limitation remain for industrialization and commercializing.

[The effect of glucose-6-phosphate dehydrogenase deficiency on allogeneic hematopoietic stem cell transplantation in patients with hematological disorders]

Objectives: To determine the effect of glucose-6-phosphate-dehydrogenase (G6PD) deficiency on patients' complications and prognosis following allogeneic stem cell hematopoietic transplantation (allo-HSCT) . Methods: 7 patients with G6PD deficiency (study group) who underwent allo-HSCT at Peking University People's Hospital from March 2015 to January 2021 were selected as the study group, and thirty-five patients who underwent allo-HSCT during the same period but did not have G6PD deficiency were randomly selected as the control group in a 1∶5 ratio. Gender, age, underlying diseases, and donors were balanced between the two groups. Collect clinical data from two patient groups and perform a retrospective nested case-control study. Results: The study group consisted of six male patients and one female patient, with a median age of 37 (range, 2-45) years old. The underlying hematologic diseases included acute myeloid leukemia (n=3), acute lymphocytic leukemia (n=2), and severe aplastic anemia (n=2). All 7 G6PD deficiency patients achieved engraftment of neutrophils within 28 days of allo-HSCT, while the engraftment rate of neutrophils was 94.5% in the control group. The median days of platelet engraftment were 21 (6-64) d and 14 (7-70) d (P=0.113). The incidence rates of secondary poor graft function in the study group and control group were 42.9% (3/7) and 8.6% (3/35), respectively (P=0.036). The CMV infection rates were 71.4% (5/7) and 31.4% (11/35), respectively (P=0.049). The incidence rates of hemorrhagic cystitis were 57.1% (4/7) and 8.6% (3/35), respectively (P=0.005), while the bacterial infection rates were 100% (7/7) and 77.1% (27/35), respectively (P=0.070). The infection rates of EBV were 14.3% (1/7) and 14.3% (5/35), respectively (P=1.000), while the incidence of fungal infection was 14.3% (1/7) and 25.7% (9/35), respectively (P=0.497). The rates of post-transplant lymphoproliferative disease (PTLD) were 0% and 5.7%, respectively (P=0.387) . Conclusions: The findings of this study indicate that blood disease patients with G6PD deficiency can tolerate conventional allo-HSCT pretreatment regimens, and granulocytes and platelets can be implanted successfully. However, after transplantation, patients should exercise caution to avoid viral infection, complications of hemorrhagic cystitis, and secondary poor graft function.

[Clinical features and risk factors for invasive fungal sinusitis after allogeneic hematopoietic stem cell transplantation]

Objective: To analyze the clinical characteristics and outcomes of patients with invasive fungal sinusitis (invasive fungal rhinosinusitis, IFR) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and explored the risk factors for IFR after allo-HSCT. Methods: Nineteen patients with IFR after allo-HSCT at Peking University People's Hospital from January 2012 to December 2021 were selected as the study group, and 95 patients without IFR after allo-HSCT during this period were randomly selected as the control group (1:5 ratio) . Results: Nineteen patients, including 10 males and 9 females, had IFR after allo-HSCT. The median age was 36 (10-59) years. The median IFR onset time was 68 (9-880) days after allo-HSCT. There were seven patients with acute myeloid leukemia, five with acute lymphoblastic leukemia, two with myelodysplastic syndrome, two with chronic myeloid leukemia, one with acute mixed-cell leukemia, one with multiple myeloma, and one with T-lymphoblastic lymph node tumor. There were 13 confirmed cases and 6 clinically diagnosed cases. The responsible fungus was Mucor in two cases, Rhizopus in four, Aspergillus in four, and Candida in three. Five patients received combined treatment comprising amphotericin B and posaconazole, one patient received combined treatment comprising voriconazole and posaconazole, nine patients received voriconazole, and four patients received amphotericin B. In addition to antifungal treatment, 10 patients underwent surgery. After antifungal treatment and surgery, 15 patients achieved a response, including 13 patients with a complete response and 2 patients with a partial response. Multivariate analysis revealed that neutropenia before transplantation (P=0.021) , hemorrhagic cystitis after transplantation (P=0.012) , delayed platelet engraftment (P=0.008) , and lower transplant mononuclear cell count (P=0.012) were independent risk factors for IFR after allo-HSCT. The 5-year overall survival rates in the IFR and control groups after transplantation were 29.00%±0.12% and 91.00%±0.03%, respectively (P<0.01) . Conclusion: Although IFR is rare, it is associated with poor outcomes in patients undergoing allo-HSCT. The combination of antifungal treatment and surgery might be effective.

Effects of three different polysaccharides on the sol gel-behavior, rheological, and structural properties of tapioca starch

The sol-gel behavior of tapioca starch (TS) plays a crucial role in the processing and quality control of flour-based products. However, natural tapioca starch has low gel strength and poor viscosity, which tremendously limits its application. To solve this problem, this study investigated the effects of κ-carrageenan (KC), konjac gum (KGM), and Mesona chinensis Benth polysaccharide (MCP) on the pasting behavior, rheological, and structural properties of tapioca starch. KC, KGM, and MCP significantly increased the viscosity of TS. With the exception of high-concentration KGM (0.5 %), all other blending systems showed decrease in setback. This may be attributed to the stronger effect of the high-concentration KC (0.5 %) and MCP (0.5 %) functional groups interacting with starch. KC, KGM, and MCP effectively improved the dynamic modulus (G' and G") of TS gel and were effective in increasing the gel strength and hardness of TS. The FT-IR analysis indicated that the short-range order of TS was mainly influenced by polysaccharides through non-covalent bonding interactions. Furthermore, it was confirmed that three polysaccharides could form dense structures by hydrogen bonding with TS. Similarly, more stable structure and pore size were observed in the microstructure diagram.

A preoperative predictive model for stage IV endometriosis

This was a retrospective study that evaluated a total of 280 patients who underwent surgery for complete removal of endometriosis to develop and validate the predictive model for stage IV endometriosis. The differences between stage I-III and stage IV endometriosis were performed by logistic regression. A model for the prediction of stage IV endometriosis was constructed, which was subsequently validated. The independent variables were visual analogue scale (VAS)≥4 [3.855, 95% confidence interval (CI): 1.675-8.871, p = 0.002], painful nodularity on uterosacral ligaments (13.954, 95% CI: 1.658-117.423, p = 0.015), and bilateral endometriosis (5.933, 95% CI: 1.931-18.225, p = 0.002). The AUC of the model was 0.777, with a sensitivity of 71.9% and specificity of 76.3% for stage IV endometriosis. Therefore, a complete collection of patient information prior to surgery, asking about pain and VAS scores, careful completion of pelvic examinations, and application of imaging techniques are conducive to better diagnosis and prediction of advanced endometriosis.IMPACT STATEMENTWhat is already known on this subject? Endometriosis, a chronic disease causing pain and infertility, is characterised by endometrial-like tissue outside the uterine cavity, which is often treated via surgery at present. Considering the risks of surgery, it is necessary to identify patients with stage IV endometriosis through non-invasive predictive models for adequate preparation for surgery. However, there is no reliable non-invasive predictive model now, despite utilisation of patient medical history, symptoms especially pain-related ones, pelvic examinations, laboratory examinations, and images in the preoperative diagnosis of endometriosis in the clinic.What do the results of this study add? A model developed based on three simple, accessible and non-invasive indicators displays good performance in predicting stage IV endometriosis.What are the implications of these findings for clinical practice and/or further research? It is conducive to diagnosing and predicting advanced endometriosis before surgery, so as to reduce the difficulty and improve the safety of surgery.

[Impact of SARS-CoV-2 infection on graft composition and early transplant outcomes following allogeneic hematopoietic stem cell transplantation]

Objective: To assess the feasibility of using donors with novel coronavirus disease 2019 (COVID-19) for allogeneic hematopoietic stem cell transplantation (allo-HSCT) when there are no other available donors and allo-HSCT cannot be delayed or discontinued. Methods: Seventy-one patients with malignant hematological diseases undergoing allo-HSCT between December 8, 2022, and January 10, 2023, were included. Of these, 16 received grafts from donors with mild COVID-19 (D-COVID(+) group) and 55 received grafts from donors without COVID-19 (D-COVID(-) group). The graft compositions were compared between the two groups. Engraftment, acute graft-versus-host disease (aGVHD), overall survival (OS), and relapse were also evaluated. Results: There were no serious side effects or adverse events in the D-COVID(+) group. The mononuclear cell dose and CD34(+) cell dose were comparable between the two groups, and no additional apheresis was required. There were no significant differences in the lymphocyte, monocyte, and T-cell subset doses between the two groups. The median natural killer cell dose in the D-COVID(+) group was significantly higher than that in the D-COVID(-) group (0.69×10(8)/kg vs. 0.53×10(8)/kg, P=0.031). The median follow-up time was 72 (33-104) days. All patients achieved primary engraftment. The 60-day platelet engraftment rates in the D-COVID(+) and D-COVID(-) groups were 100% and (96.4±0.2) %, respectively (P=0.568). There were no significant differences in neutrophil (P=0.309) and platelet (P=0.544) engraftment times. The cumulative incidence of grade 2-4 aGVHD was (37.5±1.6) % vs. (16.4±0.3) % (P=0.062), and of grade 3-4 aGVHD was 25.0% ±1.3% vs. 9.1% ±0.2% (P=0.095) in the D-COVID(+) and D-COVID(-) groups, respectively. The probabilities of 60-day OS were 100% and 98.1% ±1.8% (P=0.522) in the D-COVID(+) and D-COVID(-) groups, respectively. There was no relapse of primary disease during the study period. Conclusion: When allo-HSCT cannot be delayed or discontinued and no other donor is available, a donor with mild COVID-19 should be considered if tolerable. Larger sample sizes and longer follow-up periods are required to validate these results.

Comparison of Supraclavicular Surgery plus Radiotherapy vs. Radiotherapy Alone in Breast Cancer Patients with Synchronous Ipsilateral Supraclavicular Lymph Node Metastasis: A Multicenter Retrospective Study

PURPOSE/OBJECTIVE(S)

To evaluate and compare the outcomes of supraclavicular lymph node dissection (SLND) plus radiotherapy (RT) and RT alone for patients with synchronous ipsilateral supraclavicular lymph node metastasis (sISLM).

MATERIALS/METHODS

In all, 293 patients with sISLM across three centers were included. Of these, 85 (29.0%) received SLND plus RT and 208 (71.0%) received RT alone. All patients received preoperative systemic therapy followed by mastectomy or lumpectomy and axillary dissection. Supraclavicular recurrence-free survival (SCRFS), locoregional recurrence-free survival (LRRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) were evaluated by using the Kaplan-Meier method and multivariate Cox models. Multiple imputation was used for missing data.

RESULTS

The median follow-up duration of the RT and SLND+RT groups were 53.7 and 63.5 months, respectively. For the RT and SLND+RT groups, the 5-year SCRFS rates were 91.7% vs. 85.5% (P = 0.522), LRRFS rates were 79.1% vs. 73.1% (P = 0.412), DMFS rates were 60.4 vs. 58.8% (P = 0.708), DFS rates were 57.6% vs. 49.7% (P = 0.291), and OS rates were 71.9% vs. 62.2% (P = 0.272), respectively. There was no significant effect on any outcome when comparing SLND+RT versus RT alone in the multivariate analysis. Based on four risk factors of DFS, patients were classified into three risk groups: the intermediate- and high-risk groups had significantly lower survival outcomes than the low-risk group. SLND+RT did not improve outcomes of any risk group compared with RT alone.

CONCLUSION

Patients with sISLM may not benefit from SLND. Distant metastasis remained the major failure pattern, especially for intermediate- and high-risk groups with sISLM may not benefit from SLND. Distant metastasis remained the major failure pattern, especially for intermediate- and high-risk groups.

Rethreading Design of Ratiometric roGFP2 Mimetic Peptide for Hydrogen Peroxide Sensing

Reconstruction of the miniaturized peptide to mimic the tailored functions of protein has been attractive but challenging. Herein, initialized from the crystal structure of redox-sensitive green fluorescent protein-2 (roGFP2), we propose a practical approach to construct the roGFP2 mimetic peptide by rethreading the aromatic residues adjacent to the chromophore fragment. By fine-tuning the residues of peptides, a mini tetrapeptide (Cys-Phe-Phe-His) was designed, which can act as a hydrogen peroxide sensor using its ratiometric fluorescence. The roGFP2 mimetic tetrapeptide is biocompatible and photostable and has competitive fluorescent properties with roGFP2 by the virtue of its assembly induced emissions. We expand the ratiometric tetrapeptide for sensing hydrogen peroxide in acidic chambers. The results provide a promising approach for the artificial design of miniaturized peptides with the desired function.

[Developmental effects of TCIPP and TnBP on zebrafish (Danio rerio) embryos]

Objective: To investigate the toxicity of tris (2-chloropropyl) phosphate (TCIPP) and tributyl phosphate (TnBP) on the growth and development of zebrafish embryos, as well as to explore the underlying mechanisms at the transcriptional level. Methods: With zebrafish as a model, two hpf zebrafish embryos were exposed to TCIPP and TnBP (0.1, 1, 10, 100, 500, and 1 000 μmol/L) using the semi-static method, and their rates of lethality and hatchability were determined. The transcriptome changes of 120 hpf juvenile zebrafish exposed to environmentally relevant concentrations of 0.1 and 1 μmol/L were measured. Results: The 50% lethal concentrations (LC₅₀) of TCIPP and TnBP for zebrafish embryos were 155.30 and 27.62 μmol/L (96 hpf), 156.5 and 26.05 μmol/L (120 hpf), respectively. The 72 hpf hatching rates of TCIPP (100 μmol/L) and TnBP (10 μmol/L) were (23.33±7.72)% and (91.67±2.97)%, which were significantly decreased compared with the control group (P<0.05). Transcriptome analysis showed that TnBP had more differential genes (DEGs) than TCIPP, with a dose-response relationship. These DEGs were enriched in 32 pathways in total, including those involved in oxidative stress, energy metabolism, lipid metabolism, and nuclear receptor-related pathways, using the IPA pathway analysis. Among them, three enriched pathways overlapped between TCIPP and TnBP, including TR/RXR activation and CAR/RXR activation. Additionally, DEGs were also mapped onto pathways of LXR/RXR activation and oxidative stress for TnBP exposure only. Conclusion: Both TCIPP and TnBP have growth and developmental toxicities in zebrafish embryos, with distinct biomolecular mechanisms, and TnBP has a stronger effect than TCIPP.

Quantitative Ratiometric Biosensors Based on Fluorescent Ferrocene-Modified Histidine Dipeptide Nanoassemblies

Fluorescent proteins (FPs) provide a ratiometric readout for quantitative assessment of the destination of internalized biomolecules. FP-inspired peptide nanostructures that can compete with FPs in their capacity are the most preferred building blocks for the synthesis of fluorescent soft matter. However, realizing a ratiometric emission from a single peptide fluorophore remains exclusive since multicolor emission is a rare property in peptide nanostructures. Here, we describe a bioinspired peptidyl platform for ratiometric intracellular quantitation by employing a single ferrocene-modified histidine dipeptide. The intensiometric ratio of green to blue fluorescence correlates linearly with the concentration of the peptide by three orders of magnitude. The ratiometric fluorescence of the peptide is an assembly-induced emission originating from hydrogen bonds and aromatic interactions. Additionally, modular design enables ferrocene-modified histidine dipeptides to use as a general platform for the construction of intricate peptides that retain the ratiometric fluorescent properties. The ratiometric peptide technique promises flexibility in the design of a wide spectrum of stoichiometric biosensors for quantitatively understanding the trafficking and subcellular fate of biomolecules.

A versatile platform for colorimetric, fluorescence and photothermal multi-mode glyphosate sensing by carbon dots anchoring ferrocene metal-organic framework nanosheet

Concerns regarding pesticide residues have driven attempts to exploit accurate, prompt and straightforward approaches for food safety pre-warning. Herein, a nanozyme-mediated versatile platform with multiplex signal response (colorimetric, fluorescence and temperature) was proposed for visual, sensitive and portable detection of glyphosate (GLP). The platform was constructed based on a N-CDs/FMOF-Zr nanosensor that prepared by in situ anchoring nitrogen-doped carbon dots onto zirconium-based ferrocene metal-organic framework nanosheets. The N-CDs/FMOF-Zr possessed excellent peroxidase (POD)-like activity and thus could oxide colorless 3, 3', 5, 5'-tetramethylbenzidine (TMB) into a blue oxidized TMB (oxTMB) in presence of H₂O₂. Intriguingly, owing to the blocking effect triggered by multiple interaction between GLP and N-CDs/FMOF-Zr, its POD-like activity of the latter was remarkably suppressed, which can modulate the transformation of TMB into oxTMB, generating tri-signal responses of fluorescence enhancement, absorbance and temperature decrease. More significantly, the temperature mode can be facilely realized by a portable home-made mini-photothermal device and handheld thermometers. The proposed multimodal sensing was capable of providing sensitive results by fluorescence mode and simultaneously realized visual/portable testing by colorimetric and photothermal channels. Consequently, it exhibited more adaptability for practical applications, which can satisfy different testing requirements according to sensitivity and available instruments/meters, presenting a new horizon for exploiting multifunctional sensors.

Sediment and residual feed from aquaculture water bodies threaten aquatic environmental ecosystem: Interactions among algae, heavy metals, and nutrients

The effect of sediment and residual fish feed on aquaculture water bodies has gained increasing attention to alleviate the eutrophication and heavy metals enrichment induced by aquaculture. Thus, this study intended to reveal the possible interactions among nutrients, heavy metals, and Chlorella vulgaris (C. vulgaris) in aquaculture water bodies containing fish feed and sediment. The analyses showed that consistent with the composition of heavy metals in fish feed, manganese (Mn) and zinc (Zn) accounted for the highest proportions (68-78%) of heavy metals in sediment. Meanwhile, sediment in the centre of aquaculture water bodies (S2) contained more heavy metals than those in the perimeter (S1), but the released concentrations and rates (R_release) of heavy metals from S1 were higher than those from S2. Moreover, the biomass, growth rate, specific growth rate, and nitrogen and carbon fixation rate of C. vulgaris increased with adding fish feed, whereas superoxide dismutase (SOD) and malondialdehyde (MDA) decreased. In addition, with C. vulgaris, influenced by the release process from sediment and the uptake by C. vulgaris, the concentration and R_release of Mn, Pb, Cu, Mn, Cr and Cd from sediments coexisting with fish feed in water first increased and then decreased in general. The C. vulgaris biomass was significantly negatively related to Mn, Pb, Cu, Ni, Cr, and Cd and PO₄^3-P (P < 0.05), which was caused by the uptake of C. vulgaris and indicated that C. vulgaris biomass is easily affected by these factors. Accordingly, the input of residual fish feed and sediment should be controlled.

Color-Tunable Fluorescent Hierarchical Nanoassemblies with Concentration-Encoded Emission

Cephalopods possess a dynamic coloration behavior to change their iridescence due to the concentration-induced optical properties of chromatophores and hierarchical assembly of reflectin. However, cephalopods rarely have iridescence in the darkfield. It would be interesting to develop color-tunable fluorescent hierarchical nanoassemblies with concentration-encoded emission. Herein, to construct the bioavailable fluorophore with dynamic coloration properties, a histidine-rich peptide is designed, which can self-assemble into hierarchical nanoassemblies stabilized by hydrogen bonds and π-π stacking interactions. The peptidyl nanoassemblies emit fluorescent iridescence, encompassing the blue to orange region due to the assembly-induced emission. The fluorescence of histidine-rich peptides is color-tunable and reversible, which can be dynamically controlled in a concentration-encoded mode. Due to the coloration ability of histidine-rich peptides, fluorescent polychromatic human cells are developed, highlighting its potential role as a fluorescent candidate for future applications such as bioimaging, implantable light-emitting diodes, and photochromic camouflage.

The Safety of Cold-Chain Food in Post-COVID-19 Pandemic: Precaution and Quarantine

Since the outbreak of coronavirus disease-19 (COVID-19), cold-chain food contamination caused by the pathogenic severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has attracted huge concern. Cold-chain foods provide a congenial environment for SARS-CoV-2 survival, which presents a potential risk for public health. Strengthening the SARS-CoV-2 supervision of cold-chain foods has become the top priority in many countries. Methodologically, the potential safety risks and precaution measures of SARS-CoV-2 contamination on cold-chain food are analyzed. To ensure the safety of cold-chain foods, the advances in SARS-CoV-2 detection strategies are summarized based on technical principles and target biomarkers. In particular, the techniques suitable for SARS-CoV-2 detection in a cold-chain environment are discussed. Although many quarantine techniques are available, the field-based quarantine technique on cold-chain food with characteristics of real-time, sensitive, specific, portable, and large-scale application is urgently needed.

A food-grade vector for Streptococcus thermophilus based on the α-complementation of β-galactosidase

Streptococcus thermophilus is a common yogurt starter that consumes lactose as its primary carbon source. The enzyme β-galactosidase is essential for the lactose metabolism and the growth of this species. Streptococcus thermophilus appears to be a promising cell factory. Food-grade vectors have advantages in heterologous protein expression. This study aimed to determine whether the β-galactosidase of S. thermophilus has the α-complementary characteristic and to develop a novel food-grade vector based on this phenomenon. The N-terminal 7 to 36 AA residues of the β-galactosidase in S. thermophilus were deleted. The obtained mutant S. thermophilus Δα lost β-galactosidase activity and growth ability in the lactose medium. Subsequently, plasmids expressing α-fragments with different lengths of 1 to 36 (Sα1), 1 to 53 (Sα2), and 1 to 88 (Sα3) AA were constructed and transformed into S. thermophilus Δα. Recombinant S. thermophilus Δα expressing Sα2 or Sα3 recovered the ability to grow in the lactose medium, and their β-galactosidase activity accounted for 24.5% or 11.5% of the wild strain, respectively. These results indicated that the α-complementation system of β-galactosidase existed in S. thermophilus. Based on the characteristic, a food-grade vector pSEα was constructed. Except for Sα2, vector pSEα expressed the α-donor derived from E. coli β-galactosidase. This facilitated the construction of recombinant plasmids in E. coli DH5α and thus improved the transformation efficiency of S. thermophilus. Green fluorescent protein as a reporter protein could be highly expressed in S. thermophilus using this vector. As a result, pSEα is an efficient and safe vector for S. thermophilus with potential food applications.

Longitudinal Cognitive Decline in Patients With Mild Cognitive Impairment or Dementia Due to Alzheimer's Disease

Sensitive cognitive assessments accurately detect and track cognitive decline in Alzheimer's disease. The Cogstate battery was used to measure cognitive change in cognitively normal participants and in individuals with mild cognitive impairment and mild Alzheimer's disease enrolled in the Australian Imaging, Biomarker and Lifestyle Rate of Change Substudy. Over 18 months, verbal episodic memory performance declined for mild cognitive impairment and mild Alzeheimer's disease groups when compared to cognitively normal participants. Frequent assessments of episodic memory may facilitate early detection of cognitive decline due to Alzheimer's disease.

Modulation-free portable laser frequency and power stabilization system

The performance of laser-based instruments heavily depends on the stability of their laser source. Some instruments, such as the Cs-⁴He magnetometer, even require the frequency stabilization and the power stabilization at the same time. In this work, we design a double-locking system with a fiber-coupled output on a small bread board and apply it to the pump laser of a Cs-⁴He magnetometer. By carefully choosing the stabilization methods, we significantly improve the long-term simultaneous stability of frequency and power of the pump laser. The laser frequency drifts in 2 h are reduced from 100 to 10 MHz. For 10 h continuous measurements, their Allan deviation obtains about two orders of magnitude improvement for the averaging time larger than 200 s and reaches σ(τ) = 1.57 × 10^-9 with a 200 s averaging time. The laser power stability for 1.8 h also obtains two orders of magnitude improvement from 3.22% to 0.031%, and its power noise reaches a level that is very close to the electronic noise of the detector. Applying this stabilization system to the pump laser of a fiber-coupled Cs-⁴He magnetometer, its magnetic sensor noise is significantly reduced from 0.158 to 0.009 nT, which is a reasonable noise for magnetic field detection. With this on-board design of the laser stabilization system, it is more convenient to transform the magnetometer into an outdoor device.

SU(2)-in-SU(1,1) Nested Interferometer for High Sensitivity, Loss-Tolerant Quantum Metrology

We present experimental and theoretical results on a new interferometer topology that nests a SU(2) interferometer, e.g., a Mach-Zehnder or Michelson interferometer, inside a SU(1,1) interferometer, i.e., a Mach-Zehnder interferometer with parametric amplifiers in place of beam splitters. This SU(2)-in-SU(1,1) nested interferometer (SISNI) simultaneously achieves a high signal-to-noise ratio (SNR), sensitivity beyond the standard quantum limit (SQL) and tolerance to photon losses external to the interferometer, e.g., in detectors. We implement a SISNI using parametric amplification by four-wave mixing (FWM) in Rb vapor and a laser-fed Mach-Zehnder SU(2) interferometer. We observe path-length sensitivity with SNR 2.2 dB beyond the SQL at power levels (and thus SNR) 2 orders of magnitude beyond those of previous loss-tolerant interferometers. We find experimentally the optimal FWM gains and find agreement with a minimal quantum noise model for the FWM process. The results suggest ways to boost the in-practice sensitivity of high-power interferometers, e.g., gravitational wave interferometers, and may enable high-sensitivity, quantum-enhanced interferometry at wavelengths for which efficient detectors are not available.

Site-directed mutation of β-galactosidase from Streptococcus thermophilus for galactooligosaccharide-enriched yogurt making

β-Galactosidase is one of the most important enzymes used in dairy processing. It converts lactose into glucose and galactose, and also catalyzes galactose to form galactooligosaccharides (GOS), so-called prebiotics. However, most of the β-galactosidases from the starter cultures have low transgalactosylation activities, the process that results in galactose accumulation in yogurt. Here, a site-directed mutation strategy was attempted, to genetically modify β-galactosidase from Streptococcus thermophilus. Out of 28 Strep. thermophilus strains, a β-galactosidase gene named bgaQ, encoded for high β-galactosidase hydrolysis activity (BgaQ), was cloned from the strain Strep. thermophilus SDMCC050237. It was 3,081 bp in size, with 1,027 deduced amino acid residuals, which belonged to the GH2 family. After replacing the Tyr⁸⁰¹ and Pro⁸⁰² around the active sites of BgaQ with His⁸⁰¹ and Gly⁸⁰², the GOS synthesis of the generated mutant protein BgaQ-8012 increased from 20.5% to 26.7% at 5% lactose, and no hydrolysis activity altered obviously. Subsequently, the purified BgaQ or BgaQ-8012 was added to sterilized milk inoculated with 2 starters from Strep. thermophilus SDMCC050237 and Lactobacillus delbrueckii ssp. bulgaricus ATCC11842. The GOS yields with added BgaQ or BgaQ-8012 rose to 5.8 and 8.3 g/L, respectively, compared with a yield of 3.7 g/L without enzymes added. Meanwhile, the addition of the BgaQ or BgaQ-8012 reduced the lactose content by 49.3% and 54.4% in the fermented yogurt and shortened the curd time. Therefore, this study provided a site-directed mutation strategy for improvement of the transgalactosylation activity of β-galactosidase from Strep. thermophilus for GOS-enriched yogurt making.

Squeezed-Light Enhancement and Backaction Evasion in a High Sensitivity Optically Pumped Magnetometer

We study the effect of optical polarization squeezing on the performance of a sensitive, quantum-noise-limited optically pumped magnetometer. We use Bell-Bloom (BB) optical pumping to excite a ^{87}Rb vapor containing 8.2×10^{12}  atoms/cm^{3} and Faraday rotation to detect spin precession. The sub-pT/sqrt[Hz] sensitivity is limited by spin projection noise (photon shot noise) at low (high) frequencies. Probe polarization squeezing both improves high-frequency sensitivity and increases measurement bandwidth, with no loss of sensitivity at any frequency, a direct demonstration of the evasion of measurement backaction noise. We provide a model for the quantum noise dynamics of the BB magnetometer, including spin projection noise, probe polarization noise, and measurement backaction effects. The theory shows how polarization squeezing reduces optical noise, while measurement backaction due to the accompanying ellipticity antisqueezing is shunted into the unmeasured spin component. The method is compatible with high-density and multipass techniques that reach extreme sensitivity.

[BK virus encephalitis in children with hematopoietic stem cell transplantation]

目的

探讨异基因造血干细胞移植患儿中BK病毒（BKV）脑炎的发病率、病死率、中位发病时间、临床表现、诊治及转归等，以提高临床医师对本病的认识。

方法

回顾性分析2015年1月1日至2020年12月31日在北京大学人民医院接受单倍型造血干细胞移植治疗的709例儿童患者，其中14例诊断为BKV脑炎，分析其临床特征、治疗过程及转归。

结果

BKV脑炎发生率为1.97％（14例）。患儿多为男性（12例），中位年龄为11岁，中位发病时间为移植后第55天。最常见的临床表现为意识障碍、抽搐发作（7例）。14例患儿予阿昔洛韦、更昔洛韦单用，或联合丙种球蛋白治疗，9例患儿痊愈，1例患儿死于病毒性脑炎，4例患儿死于其他疾病，病死率为35.7％。

结论

BKV脑炎主要表现为脑炎或脑膜炎。虽然确诊BKV脑炎后积极予药物治疗，但许多患者仍死于多器官衰竭或其他并发症。当异基因造血干细胞移植患者出现神经系统症状、出血性膀胱炎时，必须高度警惕BKV脑炎，尽早施救，从而改善患者的生存率及生活质量。

Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

Transanal mesorectal excision: early outcomes in Australia and New Zealand

BACKGROUND

Transanal total mesorectal excision (taTME) aims to overcome some of the technical challenges faced when operating on mid and low rectal cancers. Specimen quality has been confirmed previously, but recent concerns have been raised about oncological safety. This multicentre prospective study aimed to evaluate the safety of taTME among early adopters in Australia and New Zealand.

METHODS

Data from all consecutive patients who had taTME for rectal cancer from July 2014 to February 2020 at six tertiary referral centres in Australasia were recorded and analysed.

RESULTS

A total of 308 patients of median age of 64 years underwent taTME. Some 75.6 per cent of patients were men, and the median BMI was 26.8 kg/m2. The median distance of tumour from anal verge was 7 cm. Neoadjuvant chemoradiotherapy was administered to 57.8 per cent of patients. The anastomotic leak rate was 8.1 per cent and there was no mortality within 30 days of surgery. Pathological examination found a complete mesorectum in 295 patients (95.8 per cent), a near-complete mesorectum in seven patients (2.3 per cent), and an incomplete mesorectum in six patients (1.9 per cent). The circumferential resection margin and distal resection margin was involved in nine patients (2.9 per cent), and two patients (0.6 per cent) respectively. Over a median follow-up of 22 months, the local recurrence rate was 1.9 per cent and median time to local recurrence was 30.5 months.

CONCLUSION

This study showed that, with appropriate training and supervision, skilled minimally invasive rectal cancer surgeons can perform taTME with similar pathological and oncological results to open and laparoscopic surgery.

Chlorella vulgaris cultivation in simulated wastewater for the biomass production, nutrients removal and CO2 fixation simultaneously

Chlorella vulgaris (C. vulgaris) was promising microalgae to simultaneously achieve biomass production, carbon dioxide (CO₂) fixation, nutrients removal and proteins production especially under different conditions of CO₂ gas and wastewaters. Results presented that maximal specific growth rate of C. vulgaris was 0.21-0.35 d^-1 and 0.33-0.43 d^-1 at 0.038% and 10% CO₂ respectively, and corresponding maximal CO₂ fixation rate was attended with 4.51-14.26 and 56.26-85.72 mg CO₂·L^-1·d^-1. C. vulgaris showed good wastewater removal efficiency of nitrogen and phosphorus at 10% CO₂ with 96.12%-99.61% removal rates. Nitrogen fixation amount achieved 41.86 mg L^-1 when the initial NH₄Cl concentration was set at 60 mg L^-1 at 10% CO₂. Improved total protein (25.01-365.49 mg) and amino acids (24.56-196.44 mg) contents of C. vulgaris biomass was observed with the increasing of added CO₂ and ammonium concentrations. Moreover, the developed kinetic function of C. vulgaris growth depends on both phosphorus quota and nitrogen quota with correlation coefficient (R²) ranged from 0.68 to 0.97. Computed maximal consumed nutrients concentrations (ΔC_max) based on Logistic function are positively related to initial NH₄⁺-N concentrations, which indicated that adding ammonium could stimulate the utilization of both phosphorus and nitrogen.

MiR-1301 promotes adipogenic and osteogenic differentiation of BMSCs by targeting Satb2

OBJECTIVE

Bone marrow mesenchymal stem cells (BMSCs) have the ability to differentiate into several cell lines and are critical for skeletal microenvironment and bone development. MiR-1301 is involved in multiple pathological and physiological processes. However, miR-1301's role in BMSCs adipogenic and osteogenic differentiation remains unclear.

MATERIALS AND METHODS

Rat BMSCs were isolated and randomly divided into control group, miR-1301 group, and miR-1301 siRNA group followed by analysis of the expression of miR-1301, Bax, Bcl-2, UNX2, and OPN, as well as FABP4 and PPARγ2 by Real Time-PCR. Cell proliferation was assessed by MTT assay and the relationship between miR-1301 and Satb2 was evaluated by the Dual-Luciferase reporter assay. Satb2 expression was detected by Western blot.

RESULTS

The pcDNA-miR-1301 plasmid was transfected into BMSCs to upregulate the expression of miR-1301, which promoted cell proliferation, decreased Bax expression, and increased Bcl-2 expression and ALP activity. In addition, it also elevated the expression of RUNX2 and OPN and decreased the expression of FABP4, PPARγ2, and Satb2. Compared with the control group, the difference was statistically significant (p<0.05); Satb2 was the target gene of miR-1301. MiR-1301 siRNA transfected into BMSCs down-regulated miR-1301 expression, inhibited cell proliferation, increased Bax expression and decreased Bcl-2 expression and ALP activity. Meanwhile, miR-1301 siRNA also reduced RUNX2 and OPN expression and increased expression of FABP4, PPARγ2 and Satb2. The difference was statistically significant compared with control group (p<0.05).

CONCLUSIONS

Regulation of miR-1301 expression in BMSCs can improve BMSCs proliferation and regulate their adipogenic and osteogenic differentiation by regulating Satb2.

Peptide transporter-related protein 2 plays an important role in glutathione transport of Streptococcus thermophilus

Streptococcus thermophilus is widely used as a starter culture in the fermentation of yogurt. Glutathione (GSH; γ-glutamyl-cysteinyl-glycine), as a tripeptide, has an important physiological role for Strep. thermophilus. However, the scope of the GSH transport proteins is still unexplored in this species. In the present study, 5 peptide transporter-related proteins (Ptrp) of Strep. thermophilus strain ST-1 were selected and then inactivated by gene insertion, respectively. Through detection and comparison of intracellular GSH content of mutant strain and wild strain, we identified 2 proteins, named Ptrp-2 and Ptrp-4, that might be related to GSH transport. Reverse-transcriptase quantitative PCR was performed to verify the gene expressions of these 2 possible GSH transport-related proteins, and it was finally determined that Ptrp-2 plays an important role in GSH transport of Strep. thermophilus. Milk fermentation experiments were further conducted to test the effect of Ptrp-2 on the characteristics of yogurt. The results showed that the fermented milk hardly curds using the mutant strain, indicating that Ptrp-2 is important for Strep. thermophilus as a yogurt starter.

Green fluorescent protein inspired fluorophores

Green fluorescence proteins (GFP) are appealing to a variety of biomedical and biotechnology applications, such as protein fusion, subcellular localizations, cell visualization, protein-protein interaction, and genetically encoded sensors. To mimic the fluorescence of GFP, various compounds, such as GFP chromophores analogs, hydrogen bond-rich proteins, and aromatic peptidyl nanostructures that preclude free rotation of the aryl-alkene bond, have been developed to adapt them for a fantastic range of applications. Herein, we firstly summarize the structure and luminescent mechanism of GFP. Based on this, the design strategy, fluorescent properties, and the advanced applications of GFP-inspired fluorophores are then carefully discussed. The diverse advantages of bioinspired fluorophores, such as biocompatibility, structural simplicity, and capacity to form a variety of functional nanostructures, endow them potential candidates as the next-generation bio-organic optical materials.

Prognostic factors influencing survival in patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for isolated colorectal peritoneal metastases: a systematic review and meta-analysis

AIM

Peritoneal metastases from colorectal cancer confer the worst survival among all metastatic sites. The adoption of cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) can offer selected patients with isolated colorectal peritoneal metastases (CRPM) a favourable long-term survival. There are numerous factors postulated to influence survival in patients undergoing CRS and HIPEC. The aim of this study was to identify the key perioperative prognostic factors that influence survival in patients undergoing CRS and HIPEC for isolated CRPM.

METHOD

A systematic review and meta-analysis were conducted to evaluate prognostic factors influencing survival in patients undergoing CRS and HIPEC for isolated CRPM.

RESULTS

Thirty-three studies fitted the inclusion criteria for the systematic review, with 25 studies included in the meta-analysis. On pooled analysis, incomplete cytoreduction, increasing peritoneal carcinoma index (PCI) and lymph node involvement were significantly associated with a worse survival. Additionally, a rectal primary [hazard ratio (HR) 1.93, 95% CI 1.10-3.37], adjuvant chemotherapy (HR 0.71, 95% CI 0.54-0.93) and perioperative grade III/IV morbidity (HR 1.59, 95% CI 1.17-2.16) were also found to significantly influence survival. Notably, tumour differentiation and signet ring cell histology did not influence survival on pooled analysis.

CONCLUSION

This meta-analysis confirms that in patients undergoing CRS and HIPEC for isolated CRPM, incomplete cytoreduction, high PCI and lymph node involvement have a negative influence on survival. In addition, a rectal primary, adjuvant chemotherapy use and grade III/IV morbidity are important factors that also significantly influence survival.

Bioinspired Fluorescent Peptidyl Nanoparticles with Rainbow Colors

The growing enthusiasm to mimic the luminous properties of fluorescent proteins (FPs) has expanded to include the potential biomedical applications of FP analogues. We developed a series of non-fluorescent oligopeptides (Fc-(X)_n; where X = F, Y, W, and H; n = 1-3) that can aggregate into fluorescent nanoparticles with rainbow colors, termed the peptidyl rainbow kit (PRK). The PRK encompasses the full visible color spectrum, and its photoluminescent properties may have originated from aggregation-induced emission (AIE). Intermolecular forces restricted the intramolecular motions of the oligopeptide residues, providing a barrier to non-radiative conformational relaxation pathways and leading to AIE fluorescence. The PRK oligopeptides are pH sensitive, biocompatible, and photostable under physiological conditions, making the PRK a promising fluorescence candidate for biomedical applications.

Measurement-induced, spatially-extended entanglement in a hot, strongly-interacting atomic system

Quantum technologies use entanglement to outperform classical technologies, and often employ strong cooling and isolation to protect entangled entities from decoherence by random interactions. Here we show that the opposite strategy-promoting random interactions-can help generate and preserve entanglement. We use optical quantum non-demolition measurement to produce entanglement in a hot alkali vapor, in a regime dominated by random spin-exchange collisions. We use Bayesian statistics and spin-squeezing inequalities to show that at least 1.52(4) × 1013 of the 5.32(12) × 1013 participating atoms enter into singlet-type entangled states, which persist for tens of spin-thermalization times and span thousands of times the nearest-neighbor distance. The results show that high temperatures and strong random interactions need not destroy many-body quantum coherence, that collective measurement can produce very complex entangled states, and that the hot, strongly-interacting media now in use for extreme atomic sensing are well suited for sensing beyond the standard quantum limit.

Enzyme-free visualization of nucleic acids during HIV infection by octopus-like DNA

It is highly desirable to develop a facile approach for the detection of the human immunodeficiency virus (HIV). To address this need, an octopus-like DNA (OLD) is designed in a one-pot method by direct folding of nine short single strands of DNA (ssDNA), which can be used to capture all the conserved HIV-1 gene efficiently though the sticky arms. The branched OLD was applied for the enzyme-free detection of HIV-1 nucleic acid and the visualization of the virus during HIV infection. The total detection procedure can be finished within 2 h with high specificity, making the OLD system a valuable tool for the rapid detection of HIV virus and further biomedical application.

Bioinspired pH-Sensitive Fluorescent Peptidyl Nanoparticles for Cell Imaging

As an invaluable tool for biomedical research, the green fluorescent proteins (GFPs) make tumor cells, amyloid plaques, and pathogenic bacteria equally visible. Here, inspired by the chromophore of GFPs, we constructed a tyrosine-based peptide that show green luminescence in the aggregation state. Similar to the optical property of GFPs, the tyrosine-based peptidyl nanoparticles are stabilized by intermolecular hydrogen bonding and emit fluorescence when the Tyr residues bear phenolic anions. In addition, the tyrosine-based peptide is cell-permeable and endosome-escaped when conjuncted with the GPGR motif of human immunodeficiency virus and can be used for stable cell imaging due to its excellent photostability, pH-sensitivity and biocompatibility in physiological conditions. The results provide a promising pathway to construct peptidyl bioluminescent agents for biomedical applications.

Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 ¹/₂ years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

Structural characterization and directed modification of Sus scrofa SAMHD1 reveal the mechanism underlying deoxynucleotide regulation

Sterile α-motif/histidine-aspartate domain-containing protein 1 (SAMHD1) is an intrinsic antiviral restriction factor known to play a vital role in preventing multiple viral infections and in the control of the cellular deoxynucleoside triphosphate (dNTP) pool. Human and mouse SAMHD1 have both been extensively studied; however, our knowledge on porcine SAMHD1 is limited. Here, we report our findings from comprehensive structural and functional studies on porcine SAMHD1. We determined the crystal structure of porcine SAMHD1 and showed that it forms a symmetric tetramer. Moreover, we modified the deoxynucleotide triphosphohydrolase (dNTPase) activity of SAMHD1 by site-directed mutagenesis based on the crystal structure, and obtained an artificial dimeric enzyme possessing high dNTPase activity. Taken together, our results define the mechanism underlying dNTP regulation and provide a deeper understanding of the regulation of porcine SAMHD1 functions. Directed modification of key residues based on the protein structure enhances the activity of the enzyme, which will be beneficial in the search for new antiviral strategies and for future translational applications.

Photo- and Aromatic Stacking-Induced Green Emissive Peptidyl Nanoparticles for Cell Imaging and Monitoring of Nucleic Acid Delivery

Owing to their potential applications in biomedicine and biotechnology, peptide nanostructures that exhibit stable intrinsic fluorescence in the visible range are highly desired. This research proposes a facile strategy to construct peptidyl virus-like nanoparticles (NVPs) that show green luminescence by coassembly of two bioactive ferrocene-diphenylalanine-based (Fc-FF) peptides. The green fluorescence of NVPs was originated from the highly ordered structures assembled by the amphiphilic Fc-FF-based peptides via strong π-π stacking interactions. In the assemblies, Fc-FF chromophore can be hydrolyzed under the natural light irradiation, which eliminates the fluorophore quenching effect of Fc and increases the aromatic stacking interactions, thereby giving rise to strong fluorescent nanoparticles. The NVPs could cross cytomembrane barriers by virtue of the HIV V3 peptide and the nuclear localization signal, and could thus be used for long-term cell imaging with excellent photostability and biocompatibility in physiological condition. In addition, NVPs could package DNA and be used to monitor the delivery of DNA, indicating great potential in the tracking and monitoring of genetic biological processes.

[Clinical analysis of hemorrhagic cystitis in children and adolescents with hematological diseases post haplo-hematopoietic stem cell transplantation]

目的

观察儿童及青少年血液病患者单倍型造血干细胞移植（haplo-HSCT）后出血性膀胱炎（HC）的临床特征并探讨其影响因素。

方法

回顾性分析2015至2016年接受haplo-HSCT的89例儿童及青少年血液病患者的临床资料。

结果

全部89例患者中，≤14岁62例（儿童组）、>14~<18岁27例（青少年组）；男56例，女33例；中位移植年龄10（1~17）岁；急性淋巴细胞白血病（ALL）44例，急性髓系白血病（AML）33例，急性混合细胞白血病（AHL）3例，骨髓增生异常综合征（MDS）9例。移植物来源均为骨髓+外周血干细胞。全部89例患者中32例（36%）发生HC，其中迟发型31例，早发型1例；Ⅰ度6例、Ⅱ度16例、Ⅲ度8例、Ⅳ度2例；HC发病中位时间为移植后25（2~55）d，中位持续时间为19（3~95）d；所有患儿均获得治愈。儿童组HC发病率低于青少年组[27.4%（17/62）对55.6%（15/27），χ²=6.466，P<0.05]。儿童组中<5岁组HC发生率低于5~14岁组[0（0/12）对34%（17/50），χ²=4.043，P<0.05]。

结论

HC是儿童及青少年血液病患者haplo-HSCT的常见并发症，总体预后良好，年龄是其发生的影响因素。

IgG1+ B-cell immunity predates IgE responses in epicutaneous sensitization to foods

BACKGROUND

The generation of IgE-mediated food allergy in humans is silent and only diagnosed upon manifestation of clinical symptoms. While experimental models have been used to investigate some mechanisms of allergic sensitization, the generation of humoral immunity and memory remains to be elucidated. Here, we defined the evolution of allergen-specific B-cell responses during epicutaneous sensitization to foods.

METHODS

Wild-type and genetic knockout animals, and drug or antibody strategies for cell depletion and immunoglobulin signaling blockade were used to investigate epicutaneous sensitization and disease progression; we analyzed allergen-specific germinal centers and IgG1⁺ memory B cells by flow cytometry, evaluated humoral responses, and determined clinical reactivity (anaphylaxis).

RESULTS

Epicutaneous sensitization caused microscopic skin damage, inflammation, and recruitment of activated dendritic cells to the draining lymph nodes. This process generated allergen-specific IgG1⁺ germinal center B cells, serum IgG1, and anaphylaxis that was mediated by the alternative pathway. Whether we used peanut and/or ovalbumin from the egg white for sensitization, the allergen-specific IgG1⁺ memory compartment predominantly exhibited an immature, pro-germinal center phenotype (PDL-2^- CD80^- CD35⁺ CD73⁺ ). Subsequent subclinical exposures to the allergen induced IgE⁺ germinal center B cells, serum IgE, and likely activated the classical pathway of anaphylaxis.

CONCLUSIONS

Our data demonstrate that IgG1⁺ B-cell immunity against food allergens in epicutaneous sensitization precedes the generation of IgE responses. Therefore, the assessment of allergen-specific cellular and humoral IgG1⁺ immunity may help to identify individuals at risk of developing IgE-mediated food allergy and hence provide a window for therapeutic interventions.