Fusarium and allied genera from China: species diversity and distribution

The genus Fusarium includes numerous important plant and human pathogens, as well as many industrially and commercially important species. During our investigation of fungal diversity in China, a total of 356 fusarioid isolates were obtained and identified from diverse diseased and healthy plants, or different environmental habitats, i.e., air, carbonatite, compost, faeces, soil and water, representing hitherto one of the most intensive sampling and identification efforts of fusarioid taxa in China. Combining morphology, multi-locus phylogeny and ecological preference, these isolates were identified as 72 species of Fusarium and allied genera, i.e., Bisifusarium (1), Fusarium (60), and Neocosmospora (11). A seven-locus dataset, comprising the 5.8S nuclear ribosomal RNA gene with the two flanking internal transcribed spacer (ITS) regions, the intergenic spacer region of the rDNA (IGS), partial translation elongation factor 1-alpha (tef1), partial calmodulin (cam), partial RNA polymerase largest subunit (rpb1), partial RNA polymerase second largest subunit (rpb2) gene regions, and partial β-tubulin (tub2), were sequenced and employed in phylogenetic analyses. A genus-level phylogenetic tree was constructed using combined tef1, rpb1, and rpb2 sequences, which confirmed the presence of four fusarioid genera among the isolates studied. Further phylogenetic analyses of two allied genera (Bisifusarium and Neocosmospora) and nine species complexes of Fusarium were separately conducted employing different multi-locus datasets, to determine relationships among closely related species. Twelve novel species were identified and described in this paper. The F. babinda species complex is herein renamed as the F. falsibabinda species complex, including descriptions of new species. Sixteen species were reported as new records from China. Citation: Wang MM, Crous PW, Sandoval-Denis M, et al. 2022. Fusarium and allied genera from China: species diversity and distribution. Persoonia 48: 1-53. https://doi.org/10.3767/persoonia.2022.48.01.

Targeting NAD metabolism regulates extracellular adenosine levels to improve the cytotoxicity of CD8+ effector T cells in the tumor microenvironment of gastric cancer

PURPOSE

Nicotinamide adenine dinucleotide (NAD+) is closely related to the pathogenesis of tumors. However, the effect of NAD+ metabolism of gastric cancer (GC) cells on immune cells remains unexplained. We targeted nicotinamide phosphoribosyltransferase (NAMPT), a rate-limiting enzyme in the NAD+ synthesis salvage pathway, to observe its effect in the immune microenvironment.

METHODS

NAMPT of GC cell lines was inhibited by using the small molecule inhibitor (FK866) and short hairpin RNA (shRNA). CCK-8 test and flow cytometry were performed to detect cell viability and apoptosis. Immunofluorescence was used to observe changes in mitochondrial membrane potential (MMP).The transfected GC cells (AGS) and patient-derived organoids (PDOs) were cocultured with activated PBMCs, followed by flow cytometric analysis (FCA) for cytokines and inhibitory marker. The level of NAD and ATP of GC cells (AGS & MKN45) was tested combined with NMN and CD39 inhibitor.

RESULTS

Targeting NAD+ by FK866 obviously reduced MMP, which ultimately inhibited proliferation and increased the apoptosis of GC cells. NAMPT silencing reduced intracellular NAD and ATP，further decreased extracellular adenosine. Meawhile, the cytokines of CD8+T cells were significantly increased after cocultured with transfected AGS, and the expression of PD-1 was distinctly decreased. NMN reversed the effect of shNAMPT and enhanced the immunosuppression. Consistent results were obtained by coculturing PBMCs with PDOs.

CONCLUSION

Restraining the function of NAMPT resulted in the functional improvement of effector CD8+ T cells by decreasing extracellular adenosine levels and inducing apoptosis of GC cells simultaneously. Therefore, this study demonstrates that NAMPT can be an effective target for gastric cancer immunotherapy.

[Experimental study on the effect of three-dimensional porous structures on the vascularization rate of artificial dermis]

Objective: To explore the effects of orienting three-dimensional porous network (type A) and honeycomb briquette-shaped vertically penetrating three-dimensional porous network (type B) on the vascularization rate of artificial dermis. Methods: The experimental research method was used. The artificial dermis was composed of a double layer of silicone layer and scaffold layer. Based on the difference of scaffold layer, they were divided into type A and type B artificial dermis (type A dermis and type B dermis, for short) containing type A and type B structure, respectively. The type A and type B structures were prepared by gradient freeze-drying technique and physical pore-making technique, respectively. The micro-morphology of two kinds of dermis scaffold was observed by scanning electron microscopy. The porosity of two kinds of dermis scaffold was measured by the Pyrex method. According to the method of national medical industry standard, the hydroxyproline content in degradation liquids and their residues in two kind of dermis were determined after degradation at 4, 8, 13, and 24 h, reflecting the degradation rates of two kinds of dermis. According to the random number table, L929 cells were divided into type A dermis group, type B dermis group, negative control group, and positive control group. The positive control group was added with minimum essential medium (MEM) containing 5% dimethyl sulfoxide, The negative control group was added with high-density polyethylene extract, and the other two groups were added with the corresponding extract. At 24 hours after culture, the growth rate of L929 cells was detected by methyl thiazolyl tetrazolium, and the cytotoxicity was graded. L929 cells and human umbilical vein endothelial cells (HUVECs) were inoculated into pore plates with two kinds of dermis preinstalled. On 1, 4, 7, and 14 d after inoculating, the adhesion and growth of L929 cells on the surfaces of the two kinds of scaffolds were detected by immunofluorescence method. On 7 d after inoculating, the migration of the above two kinds of cells into the two kinds of dermal scaffolds was detected by immunofluorescence and hematoxylin-eosin (HE) staining. Three full-thickness skin defect wounds of 5.0 cm×5.0 cm were created on both sides of the back of three 6-month-old healthy male Ba-Ma mini pigs. According to the random number table, six columns of wounds were divided into type A dermis two-step method group, type B dermis two-step method group, and type B dermis one-step method group. The wounds in type A dermis two-step method group and type B dermis two-step method group were transplanted with type A or type B dermis respectively before, and with autologous split-thickness skin grafting later. The wounds in type B dermis one-step method group were transplanted in a synchronous procedure including type B dermis (without silicone layer) and autologous skin grafting simultaneously. The bleeding, exudation, and infection of the wounds on the back in type A dermis two-step method group and type B dermis two-step method group on the 7th day after the second transplantation and in type B dermis one-step method group on the 14th day after the first transplantation were generally observed. The area of autologous skin graft was measured by the transparent film grid method, and the survival rate of autologous skin was calculated. On 4, 7, and 14 d after the first transplantation, the inflammatory cells, fibroblasts (Fbs), and capillary infiltration into the scaffolds of the three groups were detected by HE staining. On 7, 14 d after the first transplantation, the vascularization of the scaffolds was further observed by immunohistochemistry. On 28, 90 d after the first operation, the degradation of the scaffolds of type A dermis and type B dermis was observed by HE staining. Data were statistically analyzed with one-way analysis of variance, independent sample t test, and Bonferroni correction. Results: A large number of round and oval micropores were evenly distributed on the surface of type A scaffold, and the cylindrical hole walls could be observed arranging in a parallel direction in the longitudinal section. The honeycomb briquette-shaped penetrating macropores on the surface of type B scaffold were arranged in an orderly matrix. The pore walls of the honeycomb briquette-shaped penetrating macropores were connected by micropores to form a network structure. The porosity of type A dermis was (93.21±0.72)%, which was similar to (95.88±1.00)% of type B dermis (t=4.653, P>0.05). The degradation rates of type A dermis at 4, 8, 13, and 24 h were similar to those of type B dermis at the corresponding time point (t=0.232, 0.856, 0.258, 7.716, P>0.05). At 24 h after culture, the proliferation rates of L929 cells in the type A dermis group, type B dermis group, and negative control group were significantly higher than those of the positive control group (t=2 393.46, 2 538.27, 1 077.77, P<0.01). The cytotoxicity rating of cells in positive control group was grade 4, while that of the other three groups was grade zero. On 1, 4, 7, and 14 d after inoculation, both L929 cells and HUVECs proliferated in a time-dependent manner in two kinds of dermal scaffolds. The adhesion growth and proliferation rate of the two kinds of cells on the surface of type B dermis was higher than that of type A dermis. On 7 d after inoculation, both L929 cells and HUVECs covered the surface of type B dermis and migrated into one side of the silicone layer. However, the above two kinds of cells migrated slowly into type A dermis, and only a few cells were found on one side of the silicone layer. There was no bleeding, exudation, or infection in the wounds repaired by type A and type B dermis. The survival rate of autologous skin grafting of 6 wounds in each group was 100%. On 4, 7, and 14 d after the first operation, inflammatory cells, Fbs, and capillaries gradually infiltrated into the scaffold layer, and the cell infiltration rate from high to low was type B dermis one-step method group, type B dermis two-step method group, and type A dermis two-step method group. The scaffold in wound in the type B dermis one-step method group gradually collapsed on 28 d after the first operation, and completely degraded in 3 months after the first operation. The scaffold degradation rate of type A dermis two-step method group was similar to that mentioned above. Conclusions: The honeycomb briquette-shaped vertically penetrating three-dimensional porous network structure of type B scaffold can accelerate its vascularization process, which is beneficial to autogenous split-thickness skin in one-step procedure to repair full-thickness skin defects wound in Ba-Ma mini pigs. Compared with the "two-step method" of staged transplantation of type A scaffold and autologous split-thickness skin, and one-step transplantation has equal efficacy and can provide a better choice for wound treatment.

[Clinical application of a self-developed bone dust collector in mastoid cavity obliteration following mastoidectomy]

Objective: To introduce a self-developed bone dust collector designed by the authors and evaluate its efficiency in mastoid obliteration following mastoidectomy. Methods: Consecutive patients, from April 2017 to March 2018, who prepared to receive mastoidectomy were randomly divided into two groups, and in each group the bone dust was harvested by self-developed bone dust collector or by conventional used method respectively in mastoidectomy. The amount of the harvested bone dust and the time consumed in the collecting procedure were compared between two groups. The infection of the bone dust after mastoid obliteration was also evaluated during follow up. Results: 33 patients were recruited in bone dust collector group, and 31 patients in conventional method group.There is no significance of difference between two groups in sex ratio, age and pneumatization of mastoid cells (P>0.05 for all). The median amount of bone dust harvested by bone dust collector was significantly larger than that collected by conventional method (1.8 g vs 1.1 g, P<0.05). The median time spent in bone dust collector group was significantly shorter than that spent in conventional method group (4 minutes vs 6 minutes, P<0.05). No bone dust infection was found in the follow-up in all patients. Conclusion: The present self-developed bone dust collector is a easy and useful apparatus which can significantly improve the efficiency of collecting bone dust in mastoidectomy.

[Cell-penetrating chimeric apoptotic peptide AVPI-LMWP/DNA co-delivery system for cancer therapy]

To develop a cell-penetrating chimeric apoptotic peptide AVPI-LMWP/DNA co-delivery system for cancer therapy, we prepared the AVPI-LMWP/pTRAIL self-assembled complexes containing a therapeutic combination of peptide drug AVPI and DNA drug TRAIL. The chimeric apoptotic peptide AVPI-LMWP was synthesized using the standard solid-phase synthesis. The cationic AVPI-LMWP could condense pTRAIL by electrostatic interaction. The physical-chemical properties of the AVPI-LMWP/pTRAIL complexes were characterized. The cellular uptake efficiency and the inhibitory activity of the AVPI-LMWP/pTRAIL complexes on tumor cell were also performed. The results showed that the AVPI-LMWP/pTRAIL complexes were successfully prepared by co-incubation. With the increase of mass ratio (AVPI-LMWP/DNA), the particle size was decreased and the zeta potential had few change. Agarose gel electrophoresis showed that AVPI-LMWP could fully bind and condense pTRAIL at a mass ratio above 15:1. Cellular uptake efficiency was improved along with the increased ratio of W(AVPI-LMWP)/WpTRAIL. The in vitro cytotoxicity experiments demonstrated that the AVPI-LMWP/pTRAIL (W:W = 20:1) complexes was significantly more effective than the pTRAIL, AVPI-LMWP alone or LMWP/pTRAIL complexes on inhibition of HeLa cell growth. Our studies indicated that the AVPI-LMWP/pTRAIL co-delivery system could deliver plasmid into HeLa cell and induce tumor cell apoptosis efficiently, which showed its potential in cancer therapy using combination of apoptoic peptide and gene drugs.

Temporal dynamics and population genetic structure of Fusarium graminearum in the upper Midwestern United States

Fusarium graminearum sensu stricto causes Fusarium head blight (FHB) in wheat and barley, and contaminates grains with several trichothecene mycotoxins, causing destructive yield losses and economic impact in the United States. Recently, a F. graminearum strain collected from Minnesota (MN) was determined to produce a novel trichothecene toxin, called NX-2. In order to determine the spatial and temporal dynamics of NX-2 producing strains in MN, North Dakota (ND) and South Dakota (SD), a total of 463 F. graminearum strains were collected from three sampling periods, 1999-2000, 2006-2007 and 2011-2013. A PCR-RFLP based diagnostic test was developed and validated for NX-2 producing strains based on polymorphisms in the Tri1 gene. Trichothecene biosynthesis gene (Tri gene)-based polymerase chain reaction (PCR) assays and ten PCR-restriction fragment length polymorphism (RFLP) markers were used to genotype all strains. NX-2 strains were detected in each sampling period but with a very low overall frequency (2.8%) and were mainly collected near the borders of MN, ND and SD. Strains with the 3ADON chemotype were relatively infrequent in 1999-2000 (4.5%) but increased to 29.4% in 2006-2007 and 17.2% in 2011-2013. The distribution of 3ADON producing strains also expanded from a few border counties between ND and MN in 1999-2000, southward toward the border between SD and MN in 2006-2007 and westward in 2011-2013. Genetic differentiation between 2006-2007 and 2011-2013 populations (3%) was much lower than that between 1999-2000 and 2006-2007 (22%) or 1999-2000 and 2011-2013 (20%) suggesting that most change to population genetic structure of F. graminearum occurred between 1999-2000 and 2006-2007. This change was associated with the emergence of a new population consisting largely of individuals with a 3ADON chemotype. A Bayesian clustering analysis suggested that NX-2 chemotype strains are part of a previously described Upper Midwestern population. However, these analyses also suggest that the NX-2 isolates could represent a distinct population, but that interpretations of population assignment are influenced by the small number of NX-2 strains available for analysis.

In vivo tumor detection on rabbit with biopsy needle as MRE driver

Magnetic Resonance Elastography (MRE) is a phase contrast imaging technique to quantitatively measure the elasticity of tissues. Typically, the oscillating driver is placed on the surface of objects to generate shear waves. When it is applied to detect tumors in deep location, the depth penetration of the wave is limited by attenuation and the biopsy procedure has to be performed separately. In this study, we describe a method using biopsy needle as the MRE driver to produce shear waves in tissues. We made comparison between the MRE acquisitions obtained with biopsy needle and surface drivers. Because the well-defined propagation wave pattern reduces the error in wavelength calculation, the acquisitions of biopsy needle driver shows better homogeneity in stiffness map. We also performed the experiment with the biopsy needle for in vivo tumor detection in rabbits. This study demonstrates that the biopsy needle driver is more effective than the surface driver for accurately measuring the stiffness and location of the tumor.

[Correlation of peripheral blood micrometastasis to distant metastasis of breast cancer]

BACKGROUND & OBJECTIVE

Breast cancer, a whole body disease, can metastasize at early stage. This study was to explore the correlation of peripheral blood cancer cell (PBCC) content to distant metastasis of breast cancer.

METHODS

The PBCC content of 65 breast cancer patients and 8 healthy donors was detected by multi-parameter flow cytometry (FCM) with CD45 and cytokeratin staining.

RESULTS

Cancer cells were detected in peripheral blood samples from 57 of the 65 patients; the positive rate was 87.7%. No cancer cell was found in peripheral blood samples from healthy donors. The positive rate of PBCCs was correlated to T stage (r=0.271,P=0.017) and N stage (r=0.393, P=0.002). The patients were followed for 5 years; 2 were lost. Distant metastasis was found in 25 patients with PBCCs. In contrast, no metastasis was found in 8 patients without PBCCs (P<0.05).

CONCLUSION

Preoperative PBCC content is closely related to distant metastasis of breast cancer. The detection of PBCCs might be useful for individual treatment decision for breast cancer.

[Application of flow cytometric immunophenotypic analysis in the diagnosis of malignant lymphoma]

OBJECTIVE

To explore the value of flow cytometric immunophenotyping (FCI) in the diagnosis and differentiated diagnosis of lymphoma and explain the immunophenotypic features and differences of malignant lymphoma.

METHODS

Seventy four fresh samples of suspicious lymphoma were collected from Nov. 2004 to Aug. 2006. Each sample was individually evaluated by FCI. The results were analyzed and compared with the histopathological diagnosis.

RESULTS

Among the 74 cases, the FCI data consisted with the final morphological diagnosis in 61 cases (82.4%). For the diagnosis of B and T non-Hodgkin's lymphoma (NHL), thymoma, carcinoma and benign lesions of lymph node, the concordance between FCI data and morphological diagnosis were 93.5%, 100%, 100%, 100% and 81.3%, respectively.

CONCLUSION

Multi-parameter FCI analysis can provide important information and help for diagnosis of lymphoma. It is an assistant but necessary approach for the diagnosis and differential diagnosis of lymphoma.

High resolution electron microscopy of amorphous interlayers between metal thin films and silicon

High-resolution electron microscopy of amorphous interlayers (a-interlayer) formed by solid-state diffusion between metal thin films and silicon is reviewed. In this paper, an overview of the development is presented. Pertinent data obtained on the growth kinetics and structure of a-interlayers in polycrystalline metal thin films on single-crystal silicon are reported. For the Ti/Si, Zr/Si, Hf/Si, V/Si, Nb/Si and Ta/Si systems, the growth of a-interlayer was found to follow a linear law in the initial stage. Si atoms were found to be the dominant diffusing species in the solid phase amorphization in the Ti/Si, Zr/Si, and Hf/Si systems. For the Y/Si system, the stability of amorphous interlayer depends critically on the composition of the amorphous films. Auto-correlation function analysis was utilized to determine the structure of the amorphous interlayers. HRTEM in conjunction with the fast Fourier transform were applied to determine the first nucleated crystalline phase. Simultaneous presence of multiphases was observed to occur in a number of refractory metal/Si systems.

Model for gas-laser interaction: application to thermally activated laser-induced chemical vapor deposition

We present a model for the interaction between a laser and gas mixture that can be directly applied to the case of thermally activated laser-induced chemical vapor deposition (LICVD). The model involves the values of specific parameters, particularly gas pressure, laser intensity, detuning frequency, and rotational and vibrational relaxation rates, relevant to absorption, saturation, and heat-transfer processes and their interrelation. We adopt a semiclassical phenomenological approach, considering vibrational energy levels with accompanying rotational energy manifolds and both radiative and nonradiative transition processes. The model is applied to the experimental NH(3) absorption results at the R(6), R(14), and P(20) lines of a cw CO(2) laser in the 10-microm region.