Rice is the world's largest food crop, and its yield and quality are directly related to food security and human health. Grain size, as one of the important factors determining the rice yield, has been widely concerned by breeders and researchers for a long time. To decipher the regulatory mechanism of rice grain size, we obtained a multi-tiller, dwarf, and small-grain mutant htd1 by ethyl methanesulfonate (EMS) mutation from the Japonica rice cultivar 'Zhonghua 11' ('ZH11'). Genetic analysis indicated that the phenotype of htd1 was controlled by a single recessive gene. Using the mutation site map (Mutmap) method, we identified the candidate gene OsHTD1, which encoded a carotenoid cleavage dioxygenase involved in the biosynthesis of strigolactone (SL). The SL content in htd1 was significantly lower than that in 'ZH11'. Cytological analysis showed that the grain size of the mutant decreased due to the reductions in the length and width of glume cells. The function of htd1 was further verified by the CRISPR/cas9 gene editing technology. The plants with the gene knockout exhibited similar grain size to the mutant. In addition, gene expression analysis showed that the expression levels of multiple grain size-related genes in the mutant changed significantly, suggesting that HTD1 may interact with other genes regulating grain size. This study provides a new theoretical basis for research on the regulatory mechanism of rice grain size and potential genetic resources for breeding the rice cultivars with high yields.
Oryza/growth & development* ; Mutation ; Edible Grain/growth & development* ; Alleles ; Plant Proteins/genetics* ; Dioxygenases/genetics* ; Lactones/metabolism* ; Gene Expression Regulation, Plant ; Genes, Plant ; Gene Editing ; CRISPR-Cas Systems ; Phenotype

Rice (Oryza sativa L.), as a thermophilic crop, is highly susceptible to cold stress during its growth process. Chilling injury at the plumule stage and seedling stage often affects the morphological development and leads to yield reduction of rice. The exploration and utilization of cold tolerance genes are among the most direct and effective approaches to address cold stress in rice. To identify quantitative trait loci (QTLs) associated with cold tolerance at plumule and seedling stages, in this study, we measured the seedling rates and survived seedling rates of the indica rice cultivar 'HZ', the japonica cultivar 'Nekken2', and their 120 recombinant inbred lines (RILs) under cold stress. A previously constructed high-density genetic linkage map was used for the mapping of the QTLs conferring cold tolerance at the plumule and seedling stages. A total of 4 QTLs for plumule-stage cold tolerance and 9 QTLs for seedling-stage cold tolerance were detected, with the maximum limit of detection reaching 5.20. Notably, a genetically overlapping QTL for both plumule and seedling stages was identified on chromosome 8, spanning a physical interval of 24 432 953-25 295 129 bp. Candidate genes within the detected QTL intervals were screened, and quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to analyze the gene expression during the plumule and seedling stages. The results revealed that LOC_Os03g06570, LOC_Os03g07100, LOC_Os06g08280, LOC_Os08g38440, LOC_Os08g39100, and LOC_Os08g39540 exhibited significantly differential expression between the parental lines. These genes were either significantly downregulated or upregulated under cold stress. Among them, the first three gene (LOC_Os03g06570, LOC_Os03g07100, and LOC_Os06g08280) were hypothesized to be key candidates regulating the cold tolerance of rice seedlings, while the latter three genes (LOC_Os08g38440, LOC_Os08g39100, and LOC_Os08g39540) were identified as comprehensive regulators of cold tolerance during both plumule and seedling stages. These findings lay a foundation for the fine mapping and cloning of cold tolerance genes at the plumule and seedling stages, providing valuable insights for breeding cold-tolerant rice varieties.
Quantitative Trait Loci/genetics* ; Oryza/growth & development* ; Seedlings/growth & development* ; Cold Temperature ; Chromosome Mapping ; Gene Expression Regulation, Plant

Objective To investigate the antigen presentation characteristics of dendritic cells(DC)and B cells in cardiac grafts.Methods The heart of BALB/c mice was transplanted into the abdominal cavity of C57BL/6J mice.CD45+cells in the heart graft were extracted and sorted by flow cytometry at postoperative 5 d,and single cell RNA sequencing was performed.Taking DC and B cell subsets in cardiac grafts as the main study cells,the changing trend,antigen presenting ability and intercellular communication with T cells after heart transplantation were analyzed by bioinformatics analysis and flow cytometry.Gene ontology(GO)function enrichment difference analysis was adopted to prove the specific function and the reliability annotation of cell subsets.Results Germinal center-like B cell(GC-L B)was the B cell subset with the largest increase in quantity during the acute rejection phase,accounting for 87％.Classical DC(cDC)2 was the only DC subset with a significant increase in quantity during acute rejection of heart transplantation,accounting for 44％of DC subset,and it occupied the highest communication intensity with T cells after heart transplantation.Mononucleated DC(moDC)and memory B cell(MBC)were the main transmitters of T cell input signals in non-transplanted hearts,whereas transformed into cDC2 and GC-L B during the acute rejection phase.Among them,MBC and GC-L B were the main sources of T cell input signals in non-transplanted hearts and heart grafts.Conclusions Compared with DC,B cells occupy a higher number and weight in the intercellular communication with T cells in non-transplanted hearts and heart grafts,prompting that the antigen presenting activity of B cells is more active and stronger than DC in the early stage of acute rejection of heart transplantation.

Background::Homoharringtonine (HHT) is an effective anti-inflammatory, anti-viral, and anti-tumor protein synthesis inhibitor that has been applied clinically. Here, we explored the therapeutic effects of HHT in a mouse heart transplant model.Methods::Healthy C57BL/6 mice were used to observe the toxicity of HHT in the liver, kidney, and hematology. A mouse heart transplantation model was constructed, and the potential mechanism of HHT prolonging allograft survival was evaluated using Kaplan–Meier analysis, immunostaining, and bulk RNA sequencing analysis. The HHT-T cell crosstalk was modeled ex vivo to further verify the molecular mechanism of HHT-induced regulatory T cells (Tregs) differentiation. Results::HHT inhibited the activation and proliferation of T cells and promoted their apoptosis ex vivo. Treatment of 0.5 mg/kg HHT for 10 days significantly prolonged the mean graft survival time of the allografts from 7 days to 48 days ( P <0.001) without non-immune toxicity. The allografts had long-term survival after continuous HHT treatment for 28 days. HHT significantly reduced lymphocyte infiltration in the graft, and interferon-γ-secreting CD4 + and CD8 + T cells in the spleen ( P <0.01). HHT significantly increased the number of peripheral Tregs (about 20%, P <0.001) and serum interleukin (IL)-10 levels. HHT downregulated the expression of T cell receptor (TCR) signaling pathway-related genes ( CD4, H2-Eb1, TRAT1, and CD74) and upregulated the expression of IL-10 and transforming growth factor (TGF) -β pathway-related genes and Treg signature genes ( CTLA4, Foxp3, CD74, and ICOS). HHT increased CD4 + Foxp3 + cells and Foxp3 expression ex vivo, and it enhanced the inhibitory function of inducible Tregs. Conclusions::HHT promotes Treg cell differentiation and enhances Treg suppressive function by attenuating the TCR signaling pathway and upregulating the expression of Treg signature genes and IL-10 levels, thereby promoting mouse heart allograft acceptance. These findings may have therapeutic implications for organ transplant recipients, particularly those with viral infections and malignancies, which require a more suitable anti-rejection medication.

Objective:To investigate the clinical, endoscopic and pathological characteristics of synchronous multiple early gastric cancer (SMEGC), and to reduce the rate of missed diagnosis.Methods:Clinical data of 227 early gastric cancer patients treated by endoscopic submucosal dissection (ESD) and/or surgery in Songjiang Hospital, Shanghai Jiaotong University School of Medicine from January 2017 to December 2019 were retrospectively analyzed. The differences of clinical, endoscopic and pathological characteristics between solitary early gastric cancer (SEGC) group (200 cases) and SMEGC group (27 cases) were compared. The relevance of endoscopic and pathological features of major and minor lesions of SMEGC was also analyzed.Results:Among the 227 early gastric cancer patients, 27 (11.9%) were SMEGC (58 lesions), of which 25 cases were detected preoperatively, and 2 cases were reexamined within 6 months after surgery with another lesion found at a different site from the previous lesion. In the SMEGC group, the percentages of male and atrophy and intestinal metaplasia in surrounding mucosa were significantly higher than those of the SEGC group [85.2% (23/27) VS 61.5% (123/200), χ2=5.815, P=0.016; 96.3% (26/27) VS 81.0% (162/200), χ2=3.912, P=0.048]. The mean age of the SMEGC group was significantly higher than that of the SEGC group (68.7±6.7 years VS 63.8±9.8 years, t=-2.561, P=0.011). The correlation analysis showed a significant correlation between the major and minor lesions of SMEGC in the size of lesion ( r=0.640, P<0.001), vertical location ( r=0.518, P=0.006), macroscopic type ( r=0.904, P<0.001) and depth of invasion ( r=0.470, P=0.013). Conclusion:SMEGC is prevalent in elderly males with atrophic gastritis and intestinal metaplasia. It is necessary to be alert to the possibility of multiple cancer lesions, if an early cancer lesion is found under endoscopy, especially those that may have the same or similar shape and invasion depth in the same vertical distribution range.

Idiopathic hypoparathyroidism is a rare endocrine disease. It is often manifested as neuropsychiatric symptoms, especially epileptic seizures. Thus, it is easy to be misdiagnosed as primary epilepsy. The following case report details the diagnosis of a 17-year-old girl who had been misdiagnosed as primary epilepsy for a long time. She was found hypoparathyroidism during the hospitalization for the operation of ovarian mixed germ cell tumor. After whole exome sequencing, she was ultimately diagnosed as 22q11.2 deletion syndrome. This case suggested that clinicians should be aware of the possibility of hypoparathyroidism in adolescent epilepsy, especially hereditary hypoparathyroidism. At the same time, the possible high risk of tumors should also be considered in hereditary hypoparathyroidism.

Objective To explore effects of spinal-epidural anesthesia combined with epidural anesthesia for cesarean section anesthesia and hemodynamic maternal.Methods 122 cases of mothers for cesarean section surgery in Lyuliang Municipal People's Hospital from January 2012 to January 2014 were selected,and they were divided into two groups by randomized single-blind method.The control group (61 cases) was given simple subdural anesthesia (EA),while the observation group was given CSEA.The maternal hemodynamics,efficacy of the anesthesia and adverse reactions were compared between the two groups.Results The onset time of anesthesia,maximum block level,amount of anesthetic in the observation group were (3.87 ± 0.25) min,(5.04 ± 0.41) T,(6.87 ± 0.92) mL,which were significantly reduced compared with the control group (t =8.55,8.03,6.45,all P ＜ 0.05),and the duration of anesthesia was (116.76 ± 7.89) min,which was significantly increased compared with the control group (t =7.93,P＜0.05).The MAP and HR of observation group in T1,T2,T3 showed no significant differences compared with T0 (P ＞ 0.05);while the control group of patients with the MAP at T2 had obvious reduction compared with T0 (t =8.34,P ＜ 0.05),T2,T3 compared with T0 decreased significantly (t =7.87,7.56,all P ＜ 0.05).The incidence rate of adverse reaction in the observation group was 9.84％,which was significantly lower than 24.59％ of the control group,the difference was statistically significant (x2 =9.45,P ＜ 0.05).Conclusion The lumbar epidural anesthesia for cesarean section anesthesia had significantly fewer adverse reactions,and it can remain stable maternal vital signs,which was an ideal cesarean for section anesthesia.

Objective To investigate the specific activity of 24Na per unit neutron fluence,AB/Φ,in blood produced for Chinese reference man irratiaded by 252Cf neutron source,and to analyze the effects of scattering neutrons from ground,wall,and ceiling in irradiation site on it.MethodsA 252Cf neutron source of 3 × 108 n/s and the anthropomorphic phantom were used for experiments.The phantom was made from 4 mm thick of outer covering by perspex and the liquid tissue-equivalent substitute in it.The data of phantom dimensions fit into Chinese reference man.The weight ratios of H,N,O and C in substitute equal from source to long axis of phantom were 1.1,2.1,3.1 and 4.1 m,respectively.Both the neutron source and the position of xiphisternum of the phantom were 1.6 m above the floor.ResultsThe average specific activity of 24Na per unit neutron fluence was related to the irradiation-distances,d,and its The AB/ΦM corresponds to that of phantom irradiated by plane-parallel beams,and the value is about more 3% than that by BOMAB phantom reported in literature.It has shown that floor-( wall-)scattered neutrons in irradiation site have significant contribution to the specific activity of 24Na ,but they contributed relatively little to the induced neutron doses.Consequently,using the specific activity of 24 Na for assessing accidental neutron doses received by an individual,the contribution of scattered neutrons in accident site will lead dose to be overestimated,and need to be correct.

Objective To establish the model of VX2 soft tissue xenograft in rabbit, and choose the best time for PET-CT imaging. To analyze the result of the imaging with semi-quantitative, and evaluate the feasibility of the study with VX2 soft-tissue tumor model in rabbit for PET-CT imaging. Methods 20 Japanese white rabbits were successfully implanted with VX2 tumors in thighs by the injection of tissue mass suspension.Then they were scanned with PET-CT after the diameter of the tumor is ＞2 cm. Results The diameter of the tumor＞2 cm at 14 d post implant. The average volume of tumor was (114.57±9.87) cm3.The average SUVmax of tumor's and normal tissue's in the other thigh was 5.85±0.92 and 0.22±0.09 (t=27.03, P＜0.01). SUVmax was not associated with tumor volume (r=0.02, P=0.93).Conclusion The imaging of VX2 soft tissue xenograft is clear by clinic PET-CT, and it is suitable for the study of PET-CT.PET-CT imaging performed at 14 d post implantation had the highest imaging quality.

AIM To investigate whether pioglitazone can protect cortical neurons from lipopolysaccharides(LPS)-induced neurotoxicity and the mechanisms responsible for this protective effect. METHODS After 7 d cultures，cultured cortical neurons were incubated with LPS 10 mg·L~(-1) for 4-24 h with or without other drugs. In co-incubation experiments, other drugs were added to the neurons 30 min or 1 h prior to incubation with LPS. The cell viability was assessed by MTT assay. The neuronal apoptosis was quantified by scoring the percentage of cells with apoptotic nuclear morphology after Hoechst 33258 staining. The cultured cells were then fixed on the 7th day and immunocytochemically stained with phosphorylated JNK1 antibody. The protein expressions of active caspase 3 and phosphorylated JNK1 were measured by Western blot. Nitric oxide (NO) generation was measured by Griess method. RESULTS The decrease of cell viability and the increase of apoptotic cells in cultured cortical neurons were observed incubated with LPS for 24 h compared with the normal controls. The cell viability of cortical neurons was decreased from (100.0±10.9)% in the normal control group to (72.3±2.1)% in the LPS-treated group and the apoptotic cell percentages were increased from (11.5±4.2)% in the normal control group to (39.5±8.2)% in the LPS group. LPS induced the increases in phospho-JNK1, active caspase 3 expression, and NO generation. Pioglitazone 0.01, 0.1 and 1 μmol·L~(-1), respectively inhibited LPS-induced decrease in cell viability and increase of apoptotic morphology, active caspase 3 expression in cultured neurons. In LPS+pioglitazone 1 μmol·L~(-1) group, cell viability was （97.8±9.7）%, the apoptotic cells percentage was (20.6±5.0)%, NO generation (6.8±1.3)μmol·L~(-1). Furthermore, pioglitazone also inhibited LPS-induced the increase in JNK1 phosphorylation and NO generation. JNK inhibitor SP600125 5 μmol·L~(-1) significantly inhibited LPS-induced neurotoxicity, cell viability was increased from (72.3±2.1)% to (109.8±11.8)%, the apoptotic cells percentage from (39.5±8.2)% decreased to (19.1±4.8)%, NO generation from （21.1±5.0）μmol·L~(-1) decreased to（4.0±1.3）μmol·L~(-1). The PPARγ antagonist GW9662 10 μmol·L~(-1) did not reverse the effects of pioglitazone. In LPS+pioglitazone 1 μmol·L~(-1)+GW9662 10 μmol·L~(-1) group, cell viability was (90.7±6.9)%, the apoptotic cells percentage was (23.4±4.1)%, and NO concentration was (5.8±0.7)μmol·L~(-1). CONCLUSION Pioglitazone protects cortical neurons against LPS insult at least via inhibiting JNK activity and NO generation, but not PPARγ activation.