Leaf ecological stoichiometry and anatomical structural adaptation mechanisms of Quercus sect. Heterobalanus in southeastern Qinghai-Tibet Plateau.

BACKGROUND: With the dramatic uplift of the Qinghai-Tibet Plateau (QTP) and the increase in altitude in the Pliocene, the environment became dry and cold, thermophilous plants that originally inhabited ancient subtropical forest essentially disappeared. However, Quercus sect. Heterobalanus (QSH) have gradually become dominant or constructive species distributed on harsh sites in the Hengduan Mountains range in southeastern QTP, Southwest China. Ecological stoichiometry reveals the survival strategies plants adopt to adapt to changing environment by quantifying the proportions and relationships of elements in plants. Simultaneously, as the most sensitive organs of plants to their environment, the structure of leaves reflects of the long-term adaptability of plants to their surrounding environments. Therefore, ecological adaptation mechanisms related to ecological stoichiometry and leaf anatomical structure of QSH were explored. In this study, stoichiometric characteristics were determined by measuring leaf carbon (C), nitrogen (N), and phosphorus (P) contents, and morphological adaptations were determined by examining leaf anatomical traits with microscopy. RESULTS: Different QSH life forms and species had different nutrient allocation strategies. Leaves of QSH plants had higher C and P and lower N contents and higher N and lower P utilization efficiencies. According to an N: P ratio threshold, the growth of QSH species was limited by N, except that of Q. aquifolioides and Q. longispica, which was limited by both N and P. Although stoichiometric homeostasis of C, N, and P and C: N, C: P, and N: P ratios differed slightly across life forms and species, the overall degree of homeostasis was strong, with strictly homeostatic, homeostatic, and weakly homeostatic regulation. In addition, QSH leaves had compound epidermis, thick cuticle, developed palisade tissue and spongy tissue. However, leaves were relatively thin overall, possibly due to leaf leathering and lignification, which is strategy to resist stress from UV radiation, drought, and frost. Furthermore, contents of C, N, and P and stoichiometric ratios were significantly correlated with leaf anatomical traits. CONCLUSIONS: QSH adapt to the plateau environment by adjusting the content and utilization efficiencies of C, N, and P elements. Strong stoichiometric homeostasis of QSH was likely a strategy to mitigate nutrient limitation. The unique leaf structure of the compound epidermis, thick cuticle, well-developed palisade tissue and spongy tissue is another adaptive mechanism for QSH to survive in the plateau environment. The anatomical adaptations and nutrient utilization strategies of QSH may have coevolved during long-term succession over millions of years.

Effects of advance care planning on end-of-life decisions among community-dwelling elderly people and their relatives: a systematic review and meta-analysis.

BACKGROUND: Currently, more and more older people are inevitably facing the final stages of life and their need for end-of-life care is becoming more prominent. It is therefore important to understand in advance what older people expect from their approaching end-of-life care and attention. We conducted a meta-analysis to explore the influence of advance care planning (ACP) on end-of-life decision-making among older adults living in community settings and their family members. METHODS: We searched databases including PubMed, Embase, Cochrane Library, and Web of Science through 10 August 2022, to locate randomized controlled trials (RCTs) that investigated the effects of ACP on the end-of-life decision-making of community-dwelling elderly individuals and their family members. Studies we obtained from the databases were screened based on specific inclusion and exclusion criteria. The software Stata 15.0 was used for combining and analyzing data. RESULTS: A total of 8 RCTs were eligible for meta-analysis. They involved 1,292 community-dwelling elderly people. The meta-analysis results revealed the incidence of the following items among participants after the intervention of the ACP: cardiopulmonary resuscitation (CPR) [rate =26%, 95% confidence interval (CI): 11-41%], life-sustaining treatment (rate =12%, 95% CI: 6-18%), gastric gavage (rate =34%, 95% CI: 18-50%), mechanical ventilation (rate =34%, 95% CI: 14-54%), death at home (rate =7%, 95% CI: 3-12%), and death in hospital (rate =6%, 95% CI: 3-10%). The systematic review protocol was prespecified and registered in the international prospective register of systematic reviews (PROSPERO; CRD42022348900). CONCLUSIONS: According to current research, ACP is a promising treatment that can improve the end of life of elderly people living in the community and their families. However, considering the heterogeneity of the included studies, multi-center RCTs with high quality and larger sample sizes need to be conducted to confirm our conclusions.

Antifungal action and induction of resistance by Bacillus sp. strain YYC 155 against Colletotrichum fructicola for control of anthracnose disease in Camellia oleifera.

Anthracnose disease caused by Colletotrichum fructicola is a serious disease that can afflict Camellia oleifera. Biological control is a rapidly growing approach for the management of plant diseases. In this study, we investigated the bio-control efficiency and the defense responses of an endophytic Bacillus tequilensis strain YYC 155, which was isolated from the root nodules of the Crotalaria pallida against anthracnose disease, caused by C. fructicola in C. oleifera. B. tequilensis YYC 155 exhibited significant inhibitory activity against anthracnose disease, caused by C. fructicola in C. oleifera. YYC 155 can secrete extracellular hydrolases, such as chitinase and ß-1, 3-glucanase, which produce lipopeptides that are antimicrobial and forms strong biofilms. In addition, in treatment with YYC 155, the cell membranes of C. fructicola were injured and the leakage of cell contents from the mycelia of the pathogen was increased. Spraying 1 × 107 cells mL-1 bacterial suspension of YYC 155 on C. oleifera leaves enhanced the activity of key enzymes in C. oleifera associated with the phenylpropanoid pathway and increased the content of phenolic compounds and flavonoids. Results of our study indicate that B. tequilensis YYC 155 may potentially represent an effective biocontrol agent against anthracnose disease in C. oleifera.

First report of 'Candidatus Phytoplasma asteris' associated with witches'-broom disease of Macadamia ternifolia in China.

Macadamia nut (Macadamia ternifolia) was first introduced into China from Australia in 1910, and the main cultivation areas were Yunnan and Guangxi. It can be used as both a fruit and a therapeutic drug, with high economic value. In March 2021, it was observed that the M. ternifolia was showing witches'-broom, leaf yellowing and plexus bud in Dehong Prefecture, Yunnan Province, China. The terminal buds of infected plants were inhibited and the lateral buds are stimulated to germinate into twigs in advance. It was named the M. ternifolia witches'-broom disease, and was found in urban and rural areas of Mangshi, Lianghe, Yingjiang, Mangdong, Longchuan and Longling cities and counties. More than 40% of the plants were infected on the seven areas surveyed. The lateral stems from symptomatic and asymptomatic plants were cut to small pieces. The tissues were treated by fixation, dehydration and spraying-gold. And the tissues were observed under a scanning electron microscope (Hitachi S-3000N) (Pathan et al. 2010). The nearly spherical bodies were found in the phloem sieve cells of symptomatic plants. Symptomatic and asymptomatic plants were collected from seven areas, ddH2O was used as the negative control, and Dodonaea viscose witches'-broom disease plants were used as the positive control. The total plants' DNA extraction was conducted from 0.1 g tissue using the CTAB method (Porebski et al. 1997), and were stored at -20 °C in a refrigerator in the Key Laboratory of Forest Disaster Warning and Control at the Southwest Forestry University. The nested PCR was employed to amplify the 16S rRNA gene with the primers P1/P7 and R16F2/R16R2 (Lee et al. 1993; Schneider et al. 1993). PCR amplicon of 1.8 kb and 1.2 kb were amplified (GenBank accessions MW892818, MW892819, MW892820, MW892821). The direct PCR with primer pairs rp(I)F/ rp(I)R (Lee et al. 2003) specific to the ribosomal protein (rp) gene yielded amplicons of approximately 1.2 kb (GenBank accessions MZ442600, MZ442601, MZ442602, MZ442603). The fragment from 21 samples was consistent with the positive control, confirming the association of phytoplasma with the disease. Interestingly, the phytoplasma/span>16S rRNA gene and rp gene was also amplified from the 4 samples of asymptomatic plant, we speculated that the latent infection and hidden symptoms existed in Macadamia nut (Moslemkhani and Sadeghi 2011). A BLAST analysis of the 16S rRNA sequences of MTWB phytoplasma showed that it has a 99% similarity with Trema laevigata witches'-broom phytoplasma (GenBank accession MG755412). The rp sequence shared 99% identity with 'Salix tetradenia' witches'-broom phytoplasma (GenBank accession KC117314). An analysis with iPhyClassifier showed that the virtual RFLP pattern derived from the query 16S rDNA fragment of MTWB phytoplasma is most similar to the reference pattern of the 16Sr group I, subgroup B (OY-M, GenBank accession AP006628), with a pattern similarity coefficient of 0.99. The phytoplasma is identified as 'Ca. Phytoplasma asteris'-related strain belonging to sub-group 16SrI-B. The phylogenetic tree was constructed based on 16S rRNA gene and rp gene sequences by using MEGA version 6.0 (Tamura et al. 2013) with neighbor-joining (NJ) method and bootstrap support was estimated with 1000 replicates. The result indicated that the MTWB phytoplasma formed a subclade in 16SrI-B and rpI-B respectively. In 2013, Macadamia nut showed leaf hardness phyllody and shoot proliferation caused by 'Ca. Phytoplasma asteris' in Artemisa, Cuba. The concern is that, the macadamia phytoplasma is closely related to the subgroup 16SrI-F, and it is significantly different from the Chinese strains (Pérez-López et al. 2013). In addition, the MTWB phytoplasma was graft-transmitted from infected to healthy plants in nursery conditions (Akhtar et al. 2009; Ikten et al. 2014). And the grafted plants were positive for the phytoplasma in the nested PCR assays. It is noteworthy that the plants were seriously damaged by aphid and it was speculated that the insects of Homoptera caused the spread of the disease by sucking plant sap, thus the aphids that transmits MTWB in China must be determined to control the M. ternifolia witches'-broom disease. To the best of our knowledge, Macadamia nut is a new host plant of 'Ca. Phytoplasma asteris' in China. The newly emerged disease is a threat to Macadamia nut.

Use of human amniotic epithelial cells in mouse models of bleomycin-induced lung fibrosis: A systematic review and meta-analysis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) urgently requires effective treatment. Bleomycin-induced lung injury models are characterized by initial inflammation and secondary fibrosis, consistent with the pathological features of IPF. Human amniotic epithelial cells (hAECs) exhibit good differentiation potential and paracrine activity and are thus ideal for cell-based clinical therapies. The therapeutic effects of hAECs on lung fibrosis are attributed to many factors. We performed a systematic review of preclinical studies investigating the treatment of pulmonary fibrosis with hAECs to provide suggestions for their clinical use. METHODS: PubMed and EMBASE were searched for original studies describing hAEC therapy in animal bleomycin-induced pulmonary fibrosis models. After quality assessments, the number and species of experimental animals, bleomycin dose, hAEC source and dosage, time and route of administration of transplanted cells in animals, and time animals were euthanized in nine controlled preclinical studies were summarized. Ashcroft scores, lung collagen contents, inflammatory cells and cytokines were quantitatively and/or qualitatively analyzed in this review. Publication bias was also assessed. RESULTS: Each of the nine preclinical studies have unique characteristics regarding hAEC use. Ashcroft scores and lung collagen contents were decreased following hAEC transplantation in bleomycin-injured mice. Histopathology was also improved in most studies following treatment with hAECs. hAECs modulated macrophages, neutrophils, T cells, dendritic cells and the mRNA or protein levels of cytokines associated with inflammatory reactions (tumor necrosis factor-α, transforming growth factor-ß, interferon-γ and interleukin) in lung tissues of bleomycin-injured mice. CONCLUSIONS: hAECs alleviate and reverse the progression of bleomycin-induced lung fibrosis in mice and may represent a new clinical treatment for IPF. hAECs exert anti-inflammatory and anti-fibrotic effects by modulating macrophage, neutrophil, T cell, dendritic cell and related cytokine levels in mice with bleomycin-induced lung fibrosis. Cell generation and the route, source and timing of hAEC transplantation all determine the therapeutic effectiveness of hAECs.

Mesenchymal stem cell therapy for paraquat poisoning: A systematic review and meta-analysis of preclinical studies.

BACKGROUND: Paraquat (PQ) poisoning can cause multiple organ failure, in which the lung is the primary target organ. There is currently no treatment for PQ poisoning. Mesenchymal stem cells (MSCs), which differentiate into multiple cell types, have generated much enthusiasm regarding their use for the treatment of several diseases. The aim of this study was to systematically review and analyze published preclinical studies describing MSC administration for the treatment of PQ poisoning in animal models to provide a basis for cell therapy. METHODS: The electronic databases PubMed and CBMdisc were searched in this systematic review and meta-analysis. The MSC treatment characteristics of animal models of PQ poisoning were summarized. After quality assessment was performed, the effects of MSC transplantation were evaluated based on the survival rate, lung wet/dry weight, fibrosis scores, oxidative stress response, and inflammatory response. Publication bias was assessed. RESULTS: Eleven controlled preclinical studies involving MSC transplantation in animal models of PQ poisoning were included in this review. MSC therapy improved the survival rate and reduced the lung wet/dry weight and histopathological fibrosis changes in most studies. MSCs decreased serum or plasma malondialdehyde levels in the acute phase after 7 and 14 d and increased serum or plasma superoxide dismutase and glutathione levels at the same time points. IL-1ß, TNF-α and TGF-ß1 levels in blood or lung tissues were decreased to different degrees by MSCs. Lung hydroxyproline was decreased by MSCs after 14 d. No obvious evidence of publication bias was found. CONCLUSION: MSCs showed anti-fibrosis therapeutic effects in animal models of lung injury caused by PQ poisoning, which may be related to reduced oxidative stress and inflammatory cytokine levels. Our review indicates a potential therapeutic role for MSC therapy to treat PQ poisoning and serves to augment the rationale for clinical studies.

Mechanisms of human amniotic epithelial cell transplantation in treating stage III pressure ulcer in a rat model.

The aim of the present study was to determine the function of human amniotic epithelial cell transplantation (hAECT) in promoting the healing of rats with stage III pressure ulcer (PU) and to initially investigate its possible mechanisms. A total of 96 Sprague Dawley rats were allocated at random into the model, hAECT, conventional treatment or control groups (n=24 per group). In each group, 6 rats were observed to determine the wound-healing rate. The mRNA and protein expression levels of vascular endothelial growth factor (VEGF) and tumor necrosis factor (TNF)-α in the wound tissue and serum were detected using reverse transcription-quantitative polymerase chain reaction analysis and enzyme-linked immunosorbent assay. The transplantation of hAECs significantly increased the healing rate of the stage III PUs and was accompanied by the significant upregulation of VEGF mRNA and protein expression levels and the significant downregulation of TNF-α mRNA and protein expression. Immunofluorescence staining showed that, on day 7 of transplantation, hAECs remained alive inside the skin tissues. Therefore, hAECT through subcutaneous injection appears to significantly improve the wound-healing rate of stage III PUs in rats, and this effect may be associated with the upregulation of the proangiogenic factor VEGF and the downregulation of the inflammatory cytokine TNF-α.

Pathologic changes of wound tissue in rats with stage III pressure ulcers treated by transplantation of human amniotic epithelial cells.

This study aims to determine the impact of orthotopic transplantation of human amniotic epithelial cells (hAECs) on the pathologic changes of wound tissues in a self-prepared rat stage III pressure ulcer model. Ninety-six SD rats were randomly divided into the model group (group M), hAEC transplantation group (group H), traditional treatment group (group T), and the control group (group C), with 24 rats in each group. The wound healing time was observed in 6 rats from each group, and 6 rats of each group were selected for post-modeling on day(s) (D) 1, 3, and 7 for HE staining to compare the pathological changes. The healing time of group H was significantly shorter than the other three groups. Moreover, pathological observations revealed that group H exhibited significant proliferation of fibrous tissues and vessels in the dermal layer, and the appearance time and degree of skin appendages were significantly greater than that observed in the other three groups. Pathological observations showed that hAEC transplantation could significantly speed up the healing of stage III pressure ulcer.