The Diverse Mycorrizal Morphology of Rhododendron dauricum, the Fungal Communities Structure and Dynamics from the Mycorrhizosphere

It is generally believed that mycorrhiza is a microecosystem composed of mycorrhizal fungi, host plants and other microscopic organisms. The mycorrhiza of Rhododendron dauricum is more complex and the diverse morphology of our investigated results displays both typical ericoid mycorrhizal characteristics and ectomycorrhizal traits. The characteristics of ectendoomycorrhiza, where mycelial invade from the outside into the root cells, have also been observed. In order to further clarify the mycorrhizal fungi members and other fungal communities of R. dauricum mycorrhiza, and explore the effects of vegetation and soil biological factors on their community structure, we selected two woodlands in the northeast of China as samples-one is a mixed forest of R. dauricum and Quercus mongolica, and the other a mixed forest of R. dauricum, Q. mongolica, and Pinus densiflor. The sampling time was during the local growing season, from June to September. High-throughput sequencing yielded a total of 3020 fungal amplicon sequence variants (ASVs), which were based on sequencing of the internal transcribed spacer ribosomal RNA (ITS rRNA) via the Illumina NovaSeq platform. In the different habitats of R. dauricum, there are differences in the diversity of fungi obtained from mycorrhizal niches, and specifically the mycorrhizal fungal community structure in the complex vegetation of mixed forests, where R. dauricum is found, exhibits greater stability, with relatively minor changes over time. Soil fungi are identified as the primary source of fungi within the mycorrhizal niche, and the abundance of mycorrhizal fungi from mycorrhizal niches in R. dauricum is significantly influenced by soil pH, organic matter, and available nitrogen. The relationship between soil fungi and mycorrhizal fungi from mycorrhizal niches is simultaneously found to be intricate, while the genus Hydnellum emerges as a central genus among mycorrhizal fungi from mycorrhizal niches. However, there is currently a substantial gap in the foundational research of this genus, including the fact that mycorrhizal fungi from mycorrhizal niches have, compared to fungi present in the soil, proven to be more sensitive to changes in soil moisture.

[Clinical study of 19 cases of steroid-refractory gastrointestinal acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation with fecal microbiota transplantation]

Objective: To investigate the clinical efficacy of fecal microbiota transplantation (FMT) for treating steroid-refractory gastrointestinal acute graft-versus-host disease (GI-aGVHD) . Methods: This analysis included 29 patients with hematology who developed steroid-refractory GI-aGVHD after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in Huaian Hospital Affiliated to Xuzhou Medical University from March 2017 to March 2022. Among them, 19 patients underwent FMT treatment (the FMT group) and 10 patients did not (the control group). The efficacy and safety of FMT were assessed, as well as the changes in intestinal microbiota abundance, lymphocyte subpopulation ratio, peripheral blood inflammatory cytokines, and GVHD biomarkers before and after FMT treatment. Results: ① Complete remission of clinical symptoms after FMT was achieved by 13 (68.4%) patients and 2 (20.0%) controls, with a statistically significant difference (P<0.05). Intestinal microbiota diversity increased and gradually recovered to normal levels after FMT and FMT-related infections did not occur. ②The proportion of CD3(+) and CD8(+) cells in the FMT group after treatment decreased compared with the control group, and the ratio of CD4(+), regulatory T cells (Treg), and CD4(+)/CD8(+) cells increased (all P< 0.05). The interleukin (IL) -6 concentration in the FMT group was lower than that in the control group [4.15 (1.91-5.71) ng/L vs 6.82 (2.40-8.91) ng/L, P=0.040], and the IL-10 concentration in the FMT group was higher than that in the control group [12.11 (5.69-20.36) ng/L vs 7.51 (4.10-9.58) ng/L, P=0.024]. Islet-derived protein 3α (REG3α) was significantly increased in patients with GI-aGVHD, and the REG3α level in the FMT group was lower than that in the control group after treatment [30.70 (10.50-105.00) μg/L vs 74.35 (33.50-139.50) μg/L, P=0.021]. Conclusion: FMT is a safe and effective method for the treatment of steroid-refractory GI-aGVHD by restoring intestinal microbiota diversity, regulating inflammatory cytokines, and upregulating Treg cells.

[Haploidentical hematopoietic stem cell transplantation in the treatment of acquired aplastic anemia in children: a single center retrospective analysis]

Objective: To investigate the safety and efficacy of haploidentical hematopoietic stem cell transplantation with different intensity conditioning regimen in the treatment of childhood aplastic anemia (AA) . Methods: Thirty-seven AA patients who underwent haploidentical transplantation in BaYi Children's Hospital Affiliated to PLA Army General Hospital from January 2013 to January 2017 were enrolled. According to the dosage of conditioning regimen, 34 patients excluding 3 other conditioning regimens were divided into high-dosage group (regimen 2, 22 cases) and low-dosage group (regimen 3, 12 cases). The data of Engraftment, graft-vs-host disease (GVHD), hematopoietic reconstitution, relapse, infection, overall survival (OS) were analyzed. The comparison between the two groups was tested by χ(2) test. Results: A total of 35 of 37 patients achieved primary engraftment; 2 cases died of regimen-related toxicity and severe infection before the infusing of the grafts. The activation rate of CMV and EBV was 60% (21/35) . Post-transplant lymphocyte disease (PTLD) of lung occurred in one case. The cumulative incidences of acute GVHD grade Ⅰ-Ⅳ and chronic GVHD were 29% (10/35) and 34% (12/35) respectively and the incidence of extensive chronic GVHD was 6% (2/35) . The median follow-up time was 18.8 (2.9-44.1) months, the OS was 92% (34/37) .All survived patients were no longer dependent on blood transfusion and none of them had recurrence. Comparing the rates of overall survival(86%(19/22) vs.100%(12/12)) and rates of chronic GVHD(40%(8/20) vs. 17%(2/12)) in regimen 2 and regimen 3 group, there were no significant difference (χ(2)=1.742, 1.841, all P>0.05) . Significant difference was found at the incidence of Ⅰ-Ⅳ acute GVHD (10% (2/20) vs. 50% (6/12) ,χ(2)=6.200, P=0.013). Conclusions: Haploidentical hematopoietic stem cell transplantation is effective and safe. It is suitable for patients who are not eligible for matched donor transplantation. Application of reduced dose preconditioning in haploid transplantation is worth exploring.

Cloning of cDNA and the gene encoding human hepatocyte nuclear factor (HNF)-3 beta and mutation screening in Japanese subjects with maturity-onset diabetes of the young

AIMS/HYPOTHESIS

Molecular defects of the genes for transcription factors, hepatocyte nuclear factor (HNF)-4 alpha, HNF-1 alpha, HNF-1 beta and insulin promoter factor-1 cause maturity-onset diabetes of the young (MODY1, 3, 5, and 4, respectively). This suggests the HNF-related transcription cascade is important in insulin secretion which is induced by glucose. These genes and the gene encoding glycolytic enzyme glucokinase (MODY2) are, however, responsible for only 15-20% of cases of MODY in the Japanese. Searching for a novel form of MODY in this population, we cloned a new candidate gene encoding human HNF-3 beta, a winged helix transcription factor, which also belongs to the same HNF-transcription cascade.

METHODS

The cDNA clone for human HNF-3 beta was isolated from a liver cDNA library. The gene was also cloned from a genomic library and its organization and chromosomal localization were determined. We screened 68 Japanese subjects with MODY/early-onset diabetes for mutations in this gene.

RESULTS

Human HNF-3 beta is composed of 457 amino acids. The human gene, which was mapped to the segment 30 cR from SHGC-37039 on chromosome 20p by radiation hybrid mapping, spans approximately 4.5 kb and consists of three exons. Direct sequencing of the exons and flanking regions identified one missense mutation A328 V and seven polymorphisms, although the functional significance of the mutation in the pathogenesis of diabetes is not known.

CONCLUSION/INTERPRETATION

The characterization of the structure of the HNF-3 beta gene and its mapping in the framework of markers will be helpful in genetic studies of the various forms of diabetes mellitus.

Assessment of macular function by multifocal electroretinogram before and after macular hole surgery

AIM

To evaluate macular function before and after successful surgical closure of idiopathic macular holes using multifocal electroretinogram (ERG).

METHODS

40 patients (40 eyes) with idiopathic macular holes were examined using multifocal ERG both before and after vitreous surgery. The postoperative period was from 1 to 12 months.

RESULTS

Preoperatively, the electrical retinal response densities in the foveal and the perifoveal area were apparently decreased. After a mean postoperative period of 3-6 months, the foveal and perifoveal area electrical retinal response densities improved to two to four times the preoperative level and the improvement continued to 1 year after surgery.

CONCLUSION

In macular holes, the decrease in retinal electrophysiological response was not limited to the fovea but involved an area of the perifovea of 1.6 disc diameters. The electrical retinal response density of these areas gradually improved after macular hole closure.