Different regions and environments have critical roles on yield, main quality and industrialization of an industrial purple-fleshed sweetpotato (Ipomoea batatas L. (Lam.)) "Xuzishu8".

Purple-fleshed sweetpotato (PFSP) (Ipomoea batatas (L.) Lam), whose flesh is purple to dark purple, is a special variety type of sweetpotato, which has the characteristics of food crop, industrial crop and medicinal crop. The storage root (SR) of PFSP is rich in anthocyanins, starch, protein, soluble sugar, mineral elements, polyphenol, dietary fiber and so on, which has balanced and comprehensive nutritional value. And in recent years, its unique nutritional elements are increasingly known for their health functions. At present, there is no article on the characteristics and quality analysis of industrial xz8 variety. To explore the influence of different environments on the processing quality of xz8, we selected nine regions (Xuzhou, Jiawang, Pizhou, Xinyi, Peixian, Sihong, Yanchen, Xiangyang and Tianshui) to measure its yield and quality changes. The data demonstrated that xz8 has a very consistent high yield performance. In Tianshui, the anthocyanins, protein and minerals contents were significantly higher and yield also above average. Moreover, the variety with the lowest starch content exhibited the best taste. On the basis of the above results, it suggested that quite practicable to promote xz8 cultivation and suitable for processing in these areas. Thus, our present findings improve our understanding of xz8 variety and provide the basis for the industrial production of PFSP with strong prospects for success.

Effects of public health interventions and zero COVID policy on paediatric diseases: A Southern China study.

Background: With the spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in schools and communities, clinical evidence is needed to determine the impact of the pandemic and public health interventions under the zero coronavirus disease policy on the occurrence of common infectious diseases and non-infectious diseases among children. Methods: The current study was designed to analyse the occurrence of common infectious diseases before and after the pandemic outbreak in southern China. Data was obtained for 1 801 728 patients admitted into children's hospitals in Guangzhou between January 2017 and July 2022. Regression analysis was performed for data analysis. Results: The annual occurrence of common paediatric infectious diseases remarkably decreased after the pandemic compared to the baseline before the pandemic and the monthly occurrence. Cases per month of common paediatric infectious diseases were significantly lower in five periods during the local outbreak when enhanced public health measures were in place. Cases of acute non-infectious diseases such as bone fractures were not reduced. Non-pharmaceutical interventions decreased annual and monthly cases of paediatric respiratory and intestinal infections during the coronavirus disease 2019 (COVID-19) pandemic, especially when enhanced public health interventions were in place. Conclusions: Our findings provide clinical evidence that public health interventions under the dynamic zero COVID policy in the past three years had significant impacts on the occurrence of common respiratory and intestinal infectious diseases among children and adolescents but little impact on reducing non-infectious diseases such as leukaemia and bone fracture.

RNA-Sequencing Analysis Revealed Genes Associated with Sweet Potato (Ipomoea batatas (L.) Lam.) Responses to Stem Rot during Different Infection Stages.

The sweet potato, which is an important tuber crop in China, is susceptible to a variety of pathogens and insect pests during cultivation and production. Stem rot is a common sweet potato disease that seriously affects tuber yield and quality. Unfortunately, there have been relatively few studies on the mechanism mediating the stem rot resistance of sweet potatoes. In this study, a transcriptome sequencing analysis was completed using Xushu 48 samples at different stages (T1, T2, and T3) of the stem rot infection. The T1 vs. T2, T1 vs. T3, and T2 vs. T3 comparisons detected 44,839, 81,436, and 61,932 differentially expressed genes (DEGs), respectively. The DEGs encoded proteins primarily involved in alanine, aspartate, and glutamate metabolism (ko00250), carbon fixation in photosynthetic organisms (ko00710), and amino sugar and nucleotide sugar metabolism (ko00520). Furthermore, some candidate genes induced by phytopathogen infections were identified, including gene-encoding receptor-like protein kinases (RLK5 and RLK7), an LRR receptor-like serine/threonine protein kinase (SERK1), and transcription factors (bHLH137, ERF9, MYB73, and NAC053). The results of this study provide genetic insights that are relevant to future explorations of sweet potato stem rot resistance, while also providing the theoretical basis for breeding sweet potato varieties that are resistant to stem rot and other diseases.

[Interaction and Transport Characteristics of Lead and Cadmium in Different Soil-wheat Systems].

In this study, four groups of lead(Pb) and cadmium(Cd) combined treatments with different concentration ratios were set up in Hailun black soil, Xianning brown-red soil, and Changwu Heilu soil, and wheat(Zhengmai 9023) was planted for a five-month pot experiment to analyze the Pb-Cd interaction behavior on heavy metal bioaccumulation in wheat under three soil-wheat systems. The low pH brown-red soil had the highest water-soluble Cd and Pb contents with significant Pb-Cd interactions in the soil, whereas the black soil with high organic matter and Heilu soil with high calcium carbonate content exhibited lower Cd and Pb activities. Among the three soils, wheat height and dry weight showed the poorest growth performance in the Heilu soil, but the wheat height increased by 2.68-8.49 cm compared with that in the control under the Pb-Cd combined treatment, whereas Pb-Cd interaction had the least effect on wheat height and dry weight in black soil and inhibited the growth of wheat in the brown-red soil. In the transport process of Cd or Pb in wheat, Pb-Cd interaction showed quite different effects in the three soil-wheat systems. Under the 125 mg·kg-1 and 250 mg·kg-1 Pb treatments, the Pb content in wheat grain planted in brown-red soil significantly increased by 73.2% and 19.1% with the addition of Cd, respectively, and therefore there was a synergistic effect between Pb and Cd. Under the 0.3 mg·kg-1 and 0.6 mg·kg-1 Cd treatments, the Cd content in wheat grains planted in black soil decreased by 51% and 33% with the addition of Pb, respectively; therefore, there was an antagonist effect between Pb and Cd. In the Heilu soil, a synergistic effect of Cd on Pb transport in wheat leaves was only observed under high Pb treatment. Therefore, pH and organic matter content were the key factors that determined the interaction behavior of Pb and Cd. The wheat food security risk of Pb and Cd combined pollution was higher than that of single metal pollution in acidic brown-red soil and lower in high organic matter black soil, whereas the interaction of Pb and Cd had little impact on the wheat food security risk of alkaline Heilu soil.

Comparative Analysis of Saccharification Characteristics of Different Type Sweetpotato Cultivars.

As an important characteristic crop in China, sweetpotato plays an important role in the intake and supplement of nutrients. The saccharification characteristics of sweetpotato determine the edible quality and processing type. Exploring the saccharification characteristics of sweetpotato is of great significance to the selection of processing materials and the formation mechanism of service quality, but there are few relevant studies. A comparison study of two high saccharification varieties (Y25 and Z13) and one low saccharification variety (X27) was conducted to analyze their storage roots physical and chemical properties. The results show that the dry matter content, starch, and amylose content of Y25 and Z13 were significantly different from those of X27. Furthermore, the total amylase activity was significantly higher than that of X27. On the other hand, the starch gelatinization temperature was significantly lower than that of X27. The starch reduction in Y25 and Z13 is four times more than that in X27, and the maltose content of Y25 and Z13 is more than two times that of X27. Finally, the scores of sensory evaluation and physiological sweetness were significantly higher than those of X27. The results provide a theoretical basis for understanding the saccharification characteristics of sweetpotato varieties and are of guiding significance for the selection of sweetpotato parents.

Acute exacerbation of idiopathic pulmonary fibrosis treated using the Feibi recipe: Two case reports.

BACKGROUND: Rationale: No other treatment besides lung transplant is effective for idiopathic pulmonary fibrosis (IPF). Patients with IPF have poor prognosis, which may eventually lead to death. Patient concerns: Two female patients were diagnosed with IPF. In our recent follow-up, both these patients maintained a good quality of life. CASE SUMMARY: Diagnosis: Both patients had dry cough and progressive dyspnea. Interventions: The first patient was treated with prednisone, and the second patient was treated with prednisone and tripterygium glycosides. However, the symptoms did not improve and fibrosis was not controlled. Thus, the Feibi recipe was used. Outcomes: No deterioration was observed after the treatment, and the dry cough and its effect were ameliorated. Furthermore, they are still alive and the quality of their lives has improved. CONCLUSION: These two cases suggest that the Feibi recipe and other traditional Chinese medicine therapies could be beneficial for IPF treatment.

Effects of excitation power density on the Stern-Volmer constant measurement.

The Stern-Volmer constant (KSV) is an important parameter to describe the capability of energy transfer to oxygen for porphyrin and its derivatives. By fitting Stern-Volmer equation, IP0/IP = 1 + KSV[O2], the KSV is generally determined through phosphorescence intensities (IP) under aerobic and oxygen-free conditions. In this work, the effect of excitation power density on the KSV measurement is theoretically analyzed and experimentally studied, using palladium octaethylporphyrin (PdOEP) as an example. The IP of PdOEP increased nonlinearly with excitation power density, and the power dependent slope of IP0/IP could be obtained. By way of the functional relationship between the slope of IP0/IP and power density, the real KSV of PdOEP was fitted to be 58 ± 2 kPa-1. The oxygen-dependent phosphorescence lifetimes (τP) and IP under a weak excitation power are also measured to calculate the real KSV, which verifies our analysis.

Accurate Determination of the Photosensitizer Stern-Volmer Constant by the Oxygen-Dependent Consumption of 1,3-Diphenylisobenzofuran.

Because of the absence of phosphorescence, the Stern-Volmer constant (KSV) of the photosensitizer is hard to determine accurately. Although the delayed fluorescence and correlated fluorescence methods have been proposed to determine KSV, the weak signal detection and non-uniform excitation enlarged the measurement error. In this work, a method was proposed to accurately determine KSV by oxygen-dependent consumption of 1,3-diphenylisobenzofuran. The consumption time (δ), as a measurable quantity, is introduced and could be obtained by the absorption spectrum with a high signal-to-noise ratio. Analytically, δ is linearly related to the inverse of oxygen content, and the ratio of the intercept to the slope equals KSV. Experimentally, rose Bengal was selected to perform this determination; the KSV is measured to be 43(1) kPa-1, and the error is reduced by 1 order of magnitude. In addition, metalloporphyrin was used to verify this method.

Experimental Verification of the Accuracy of Oxygen-Varying Correlated Fluorescence for Determining the Quenching Constant KSV.

The oxygen-varying correlated fluorescence provides an effective strategy to gain the quenching constant KSV for a non-phosphorescent system. Owing to the absence of detectable phosphorescence emission in general optical spectroscopy, the facticity of this method has never been verified. Here, the correct way to determine KSV by oxygen-varying correlated fluorescence was systematically studied in detail. We selected gadolinium protoporphyrin IX (Gd-PpIX) to establish a fluorescence and phosphorescence dual emission system. Then, KSV of Gd-PpIX can be obtained by the change of fluorescence intensity (IF) with oxygen concentration using the method of correlated fluorescence at intense pump power; meanwhile, the value can also be determined from the relationship of the phosphorescence intensity ratio and oxygen content by the Stern-Volmer equation under relatively low power density. It was found that the KSV values obtained by the above two methods were 12.2(1) and 11.9(7) kPa-1, respectively. Our results successfully verified the accuracy of oxygen-varying correlated fluorescence for determining the KSV by the phosphorescence property and fluorescence saturation of Gd-PpIX.

Bradykinin-pretreated Human cardiac-specific c-kit+ Cells Enhance Exosomal miR-3059-5p and Promote Angiogenesis Against Hindlimb Ischemia in mice.

BACKGROUND: Protection of cardiac function following myocardial infarction was largely enhanced by bradykinin-pretreated cardiac-specific c-kit+ (BK-c-kit+) cells, even without significant engraftment, indicating that paracrine actions of BK-c-kit+ cells play a pivotal role in angiogenesis. Nevertheless, the active components of the paracrine actions of BK-c-kit+ cells and the underlying mechanisms remain unknown. This study aimed to define the active components of exosomes from BK-c-kit+ cells and elucidate their underlying protective mechanisms. METHODS: Matrigel tube formation assay, cell cycle, and mobility in human umbilical vein endothelial cells (HUVECs) and hindlimb ischemia (HLI) in mice were applied to determine the angiogenic effect of condition medium (CM) and exosomes. Proteome profiler, microRNA sponge, Due-luciferase assay, microRNA-sequencing, qRT-PCR, and Western blot were used to determine the underlying mechanism of the angiogenic effect of exosomes from BK-c-kit+. RESULTS: As a result, BK-c-kit+ CM and exosomes promoted tube formation in HUVECs and the repair of HLI in mice. Angiogenesis-related proteomic profiling and microRNA sequencing revealed highly enriched miR-3059-5p as a key angiogenic component of BK-c-kit+ exosomes. Meanwhile, loss- and gain-of-function experiments revealed that the promotion of angiogenesis by miR-3059-5p was mainly through suppression of TNFSF15-inhibited effects on vascular tube formation, cell proliferation and cell migration. Moreover, enhanced angiogenesis of miR-3059-5p-inhibited TNFSF15 has been associated with Akt/Erk1/2/Smad2/3-modulated signaling pathway. CONCLUSION: Our results demonstrated a novel finding that BK-c-kit+ cells enrich exosomal miR-3059-5p to suppress TNFSF15 and promote angiogenesis against hindlimb ischemia in mice.

DWL-4-140: A allene small molecule targeting STING that alleviates lupus-like phenotype in Trex1-/- mice.

The innate immune system plays a critical role in the host response against pathogenic microbial infection. However, aberrant activation of the innate immune pathways is a characteristic feature of various diseases. Thus, targeted drugs must be developed based on the understanding of the innate immune signaling pathways. This study demonstrated that an allene small molecule (DWL-4-140) can efficiently and selectively exert regulatory effects on the stimulator of interferon genes (STING), resulting in the downregulation of DNA-induced interferon responses. Mechanistically, DWL-4-140 targeted the cyclized nucleotide-binding domain (CBD) of STING, inhibiting the assembly of the STING multimeric complex and the recruitment of downstream signaling mediators. In addition to downregulating the 10-carboxymethyl-9-acridanone-induced production of inflammatory factors, DWL-4-140 alleviated the pathological features of Trex1 deletion-induced lupus in mice. Thus, this study demonstrated that DWL-4-140 pharmacologically inhibits STING with potential therapeutic applications in auto-inflammatory diseases.

A New Insight into the Singlet Oxygen Mechanism for Photodynamic Therapy.

Modern photodynamic therapy has been built on the mechanism of the interaction between the photosensitizer (porphyrin derivatives) and oxygen to produce singlet oxygen, which relies on energy transfer from the triplet excited state (T1) of porphyrin to the excited state of oxygen. In this process, the energy transfer from the singlet excited state (S1) of porphyrin to oxygen is believed to be not pronounced as the rapid decay of S1 and the large energy mismatch. Here, we have evidenced the existence of an energy transfer between S1 and oxygen, which can contribute to the production of singlet oxygen. For hematoporphyrin monomethyl ether (HMME), the Stern-Volmer constant of S1 (KSV') is 0.023 kPa-1, according to the oxygen concentration-dependent steady fluorescence intensities. In addition, fluorescence dynamic curves of S1 under various oxygen concentrations have also been measured through ultrafast pump probe experiments to further verify our results.

Identification and functional characterization of a flavonol synthase gene from sweet potato [Ipomoea batatas (L.) Lam.].

Flavonol synthase (FLS) is a key enzyme of the flavonoid biosynthetic pathway, which catalyzes the conversion of dihydroflavonols into flavonols. In this study, the FLS gene IbFLS1 was cloned and characterized from sweet potato. The resulting IbFLS1 protein showed a high similarity with other plant FLSs. The conserved amino acids (HxDxnH motifs) binding ferrous iron and residues (RxS motifs) binding 2-oxoglutarate were found in IbFLS1 at conserved positions, as in other FLSs, suggesting that IbFLS1 belongs to the 2-oxoglutarate-dependent dioxygenases (2-ODD) superfamily. qRT-PCR analysis showed an organ-specific pattern of expression of the IbFLS1 gene, which was predominantly expressed in young leaves. The recombinant IbFLS1 protein could catalyze the conversion of dihydrokaempferol and dihydroquercetin to kaempferol and quercetin, respectively. The results of subcellular localization studies indicated that IbFLS1 was found mainly in the nucleus and cytomembrane. Furthermore, silencing the IbFLS gene in sweet potato changed the color of the leaves to purple, substantially inhibiting the expression of IbFLS1 and upregulating the expression of genes involved in the downstream pathway of anthocyanin biosynthesis (i.e., DFR, ANS, and UFGT). The total anthocyanin content in the leaves of the transgenic plants was dramatically increased, whereas the total flavonol content was significantly reduced. Thus, we conclude that IbFLS1 is involved in the flavonol biosynthetic pathway and is a potential candidate gene of color modification in sweet potato.

Quantitative analysis of dose interval effect of Pb-Cd interaction on Oryza sativa L. root.

Combined pollution of cadmium (Cd) and lead (Pb) occurs frequently in agriculture lands, which has received increasing research attention. However, little is known about the interaction behaviors of Cd and Pb at various concentrations in the mixture. This study evaluated the single and combined effects of Cd and Pb on rice (Oryza sativa L.) root elongation through acute exposure test. The combined pollution was analyzed with the concentration addition (CA) model, independent action (IA) model and mathematical statistical methods. The dose-response results revealed that the interaction could weaken the toxicity of both Pb and Cd, and Cd had a more significant inhibitory effect on Pb toxicity. The predicted values of CA and IA models were consistently lower than the observed values in the relative root elongation range of 0-60%. Further, combining the CA or IA model with mathematical statistical methods, the interaction of Pb and Cd at similar concentrations showed a significant antagonistic effect on rice root elongation. At low Pb concentrations (Cd > 0.0195, Pb < 0.015 mg/L), there was a synergistic effect of the mixture on rice root; at high Pb concentrations (Cd < 0.225, Pb ≥ 1.25 mg/L), Pb dominated the toxicity on rice root. This is the first report of a systematic method for assessing heavy metal interaction at different concentration levels, which may facilitate the formulation of control standards of heavy metal combined pollution in agricultural land.

Insight into the Heavy Atom Effect Induced by Environmental Heavy Atoms for Gadolinium-Labeled Hematoporphyrin Monomethyl Ether.

Environmental heavy atoms can further enhance the room temperature phosphorescence (RTP) emissions of gadolinium-labeled hematoporphyrin monomethyl ether (Gd-HMME) by way of the external heavy atom effect (HAE). However, the macroscopic phosphorescence intensity covered the intrinsic effect of the environmental heavy atoms. In this study, a method of separating the external HAE from the total is performed, and a quantity to describe the intrinsic nature of external HAE is defined. The environmental Gd3+ concentration evolution of the phosphorescent transition rate (kP) is obtained by correlated absorption, emission, and time-resolved spectroscopy. The kP increases linearly with environmental Gd3+ concentration, while the intercept kP0 coincides with that of the internal HAE. The slope κ could be calculated, and it is a quantity free of the Gd3+ concentration and only relies on the type of environmental heavy atoms. In addition, the environmental Lu3+ exhibits similar functionality to Gd3+ in external HAE. Environmental Pd2+ quenches the phosphorescence intensity macroscopically, while it enhances the HAE intrinsically. Our method provides an alternative insight into the intrinsic nature of environmental heavy atoms.

Mitochondrial Cardiomyopathy: Molecular Epidemiology, Diagnosis, Models, and Therapeutic Management.

Mitochondrial cardiomyopathy (MCM) is characterized by abnormal heart-muscle structure and function, caused by mutations in the nuclear genome or mitochondrial DNA. The heterogeneity of gene mutations and various clinical presentations in patients with cardiomyopathy make its diagnosis, molecular mechanism, and therapeutics great challenges. This review describes the molecular epidemiology of MCM and its clinical features, reviews the promising diagnostic tests applied for mitochondrial diseases and cardiomyopathies, and details the animal and cellular models used for modeling cardiomyopathy and to investigate disease pathogenesis in a controlled in vitro environment. It also discusses the emerging therapeutics tested in pre-clinical and clinical studies of cardiac regeneration.

Genome-Wide Identification of the A20/AN1 Zinc Finger Protein Family Genes in Ipomoea batatas and Its Two Relatives and Function Analysis of IbSAP16 in Salinity Tolerance.

Stress-associated protein (SAP) genes-encoding A20/AN1 zinc-finger domain-containing proteins-play pivotal roles in regulating stress responses, growth, and development in plants. They are considered suitable candidates to improve abiotic stress tolerance in plants. However, the SAP gene family in sweetpotato (Ipomoea batatas) and its relatives is yet to be investigated. In this study, 20 SAPs in sweetpotato, and 23 and 26 SAPs in its wild diploid relatives Ipomoea triloba and Ipomoea trifida were identified. The chromosome locations, gene structures, protein physiological properties, conserved domains, and phylogenetic relationships of these SAPs were analyzed systematically. Binding motif analysis of IbSAPs indicated that hormone and stress responsive cis-acting elements were distributed in their promoters. RT-qPCR or RNA-seq data revealed that the expression patterns of IbSAP, ItbSAP, and ItfSAP genes varied in different organs and responded to salinity, drought, or ABA (abscisic acid) treatments differently. Moreover, we found that IbSAP16 driven by the 35 S promoter conferred salinity tolerance in transgenic Arabidopsis. These results provided a genome-wide characterization of SAP genes in sweetpotato and its two relatives and suggested that IbSAP16 is involved in salinity stress responses. Our research laid the groundwork for studying SAP-mediated stress response mechanisms in sweetpotato.

Intrinsic Characterization Method on the Heavy Atom Effect of Metalloporphyrins.

The presence of room temperature phosphorescence emission in metalloporphyrin, via the transition from the excited triplet state (T1) to the ground state (S0), relies on the chelated heavy metal ions, which is known as the heavy atom effect (HAE). Despite the HAE being a reliable method to tune the phosphorescence process widely, the realization of the HAE nature is a tough task as the induced phosphorescence process is sensitive to not only the specie of bonded heavy atoms but also chemical environments such as the oxygen quenching and solvent effect. In this study, we have aimed at a quantitative determination of the intrinsic phosphorescent transition rate (kP) in metalloporphyrin gadolinium-labeled hematoporphyrin monomethyl ether (Gd-HMME). After the theoretical analysis based on the rate equation model to remove the nonintrinsic contribution and the experimental results of phosphorescence, the kP is calculated to be ∼2.4 × 10-4 µs-1. This study enables us to approach the intrinsic energy characteristic of metalloporphyrins; moreover, our work provides an effective pathway for the further optimization of the varied functional metalloporphyrin.

A C2-Domain Abscisic Acid-Related Gene, IbCAR1, Positively Enhances Salt Tolerance in Sweet Potato (Ipomoea batatas (L.) Lam.).

Plant C2-domain abscisic acid-related (CAR) protein family plays an important role in plant growth, abiotic stress responses, and defense regulation. In this study, we cloned the IbCAR1 by homologous cloning method from the transcriptomic data of Xuzishu8, which is a sweet potato cultivar with dark-purple flesh. This gene was expressed in all tissues of sweet potato, with the highest expression level in leaf tissue, and it could be induced by NaCl and ABA. Subcellular localization analyses indicated that IbCAR1 was localized in the nucleus and plasma membrane. The PI staining experiment revealed the distinctive root cell membrane integrity of overexpressed transgenic lines upon salt stress. Salt stress significantly increased the contents of proline, ABA, and the activity of superoxide dismutase (SOD), whereas the content of malondialdehyde (MDA) was decreased in overexpressed lines. On the contrary, RNA interference plants showed sensitivity to salt stress. Overexpression of IbCAR1 in sweet potatoes could improve the salt tolerance of plants, while the RNAi of IbCAR1 significantly increased sensitivity to salt stress in sweet potatoes. Meanwhile, the genes involved in ABA biosynthesis, stress response, and reactive oxygen species (ROS)-scavenging system were upregulated in overexpressed lines under salt stress. Taken together, these results demonstrated that IbCAR1 plays a positive role in salt tolerance by relying on the ABA signal transduction pathway, activating the ROS-scavenging system in sweet potatoes.

Topical and intravenous administration of human umbilical cord mesenchymal stem cells in patients with diabetic foot ulcer and peripheral arterial disease: a phase I pilot study with a 3-year follow-up.

BACKGROUND: Diabetic foot ulcer (DFU) is a serious chronic complication of diabetes mellitus that contributes to 85% of nontraumatic lower extremity amputations in diabetic patients. Preliminary clinical benefits have been shown in treatments based on mesenchymal stem cells for patients with DFU or peripheral arterial disease (PAD). However, the long-term safety and benefits are unclear for patients with both DFU and PAD who are not amenable to surgical revascularization. METHODS: In this phase I pilot study, 14 patients with PAD and incurable DFU were enrolled to assess the safety and efficacy of human umbilical cord mesenchymal stem cell (hUC-MSC) administration based on conservative treatments. All patients received topical and intravenous administrations of hUC-MSCs at a dosage of 2 × 105 cells/kg with an upper limit of 1 × 107 cells for each dose. The adverse events during treatment and follow-up were documented for safety assessments. The therapeutic efficacy was assessed by ulcer healing status, recurrence rate, and 3-year amputation-free rate in the follow-up phase. RESULTS: The safety profiles were favorable. Only 2 cases of transient fever were observed within 3 days after transfusion and considered possibly related to hUC-MSC administration intravenously. Ulcer disclosure was achieved for more than 95% of the lesion area for all patients within 1.5 months after treatment. The symptoms of chronic limb ischaemia were alleviated along with a decrease in Wagner scores, Rutherford grades, and visual analogue scale scores. No direct evidence was observed to indicate the alleviation of the obstruction in the main vessels of target limbs based on computed tomography angiography. The duration of rehospitalization for DFU was 2.0 ± 0.6 years. All of the patients survived without amputation due to the recurrence of DFU within 3 years after treatments. CONCLUSIONS: Based on the current pilot study, the preliminary clinical benefits of hUC-MSCs on DFU healing were shown, including good tolerance, a shortened healing time to 1.5 months and a favorable 3-year amputation-free survival rate. The clinical evidence in the current study suggested a further phase I/II study with a larger patient population and a more rigorous design to explore the efficacy and mechanism of hUC-MSCs on DFU healing. TRIAL REGISTRATION: The current study was registered retrospectively on 22 Jan 2022 with the Chinese Clinical Trial Registry (ChiCTR2200055885), http://www.chictr.org.cn/showproj.aspx?proj=135888.