Triglyceride-glucose index and health outcomes: an umbrella review of systematic reviews with meta-analyses of observational studies.

BACKGROUND: Numerous meta-analyses have explored the association between the triglyceride-glucose (TyG) index and diverse health outcomes, yet the comprehensive assessment of the scope, validity, and quality of this evidence remains incomplete. Our aim was to systematically review and synthesise existing meta-analyses of TyG index and health outcomes and to assess the quality of the evidence. METHODS: A thorough search of PubMed, EMBASE, and Web of Science databases was conducted from their inception through to 8 April 2024. We assessed the quality of reviews using A Measurement Tool to Assess Systematic Reviews (AMSTAR) and the certainty of the evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. This study was registered with PROSPERO (CRD: 42024518587). RESULTS: Overall, a total of 95 associations from 29 meta-analyses were included, investigating associations between TyG index and 30 health outcomes. Of these, 83 (87.4%) associations were statistically significant (P < 0.05) according to the random effects model. Based on the AMSTAR tool, 16 (55.2%) meta-analyses were high quality and none was low quality. The certainty of the evidence, assessed by the GRADE framework, showed that 6 (6.3%) associations were supported by moderate-quality evidence. When compared with the lowest category of the TyG index, the risk of contrast-induced nephropathy (CIN) [relative risk (RR) = 2.25, 95%CI 1.82, 2.77], the risk of stroke in patients with diabetes mellitus (RR = 1.26, 95%CI 1.18, 1.33) or with acute coronary syndrome disease (RR = 1.56, 95%CI 1.06, 2.28), the prognosis of coronary artery disease (CAD)-non-fatal MI (RR = 2.02, 95%CI 1.32, 3.10), and the severity of CAD including coronary artery stenosis (RR = 3.49, 95%CI 1.71, 7.12) and multi-vessel CAD (RR = 2.33, 95%CI 1.59, 3.42) increased with high TyG index. CONCLUSION: We found that the TyG index was positively associated with many diseases including the risk of CIN and stroke, the prognosis of CAD, and the severity of CAD which were supported by moderate-quality evidence. TyG index might be useful to identify people at high-risk for developing these diseases.

Per- and polyfluoroalkyl substances and human health outcomes: An umbrella review of systematic reviews with meta-analyses of observational studies.

BACKGROUND: Although evidence on the association between per- and polyfluoroalkyl substances (PFASs) and human health outcomes has grown exponentially, specific health outcomes and their potential associations with PFASs have not been conclusively evaluated. METHODS: We conducted a comprehensive search through the databases of PubMed, Embase, and Web of Science from inception to February 29, 2024, to identify systematic reviews with meta-analyses of observational studies examining the associations between the PFASs and multiple health outcomes. The quality of included studies was evaluated using the A Measurement Tool to Assess Systematic Reviews (AMSTAR) tool, and credibility of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria. The protocol of this umbrella review (UR) had been registered in PROSPERO (CRD 42023480817). RESULTS: The UR identified 157 meta-analyses from 29 articles. Using the AMSTAR measurement tool, all articles were categorized as of moderate-to-high quality. Based on the GRADE assessment, significant associations between specific types of PFASs and low birth weight, tetanus vaccine response, and triglyceride levels showed high certainty of evidence. Moreover, moderate certainty of evidence with statistical significance was observed between PFASs and health outcomes including lower BMI z-score in infancy, poor sperm progressive motility, and decreased risk of preterm birth as well as preeclampsia. Fifty-two (33%) associations (e.g., PFASs and gestational hypertension, cardiovascular disease, etc) presented low certainty evidence. Additionally, eighty-five (55%) associations (e.g., PFASs with infertility, lipid metabolism, etc) presented very low certainty evidence. CONCLUSION: High certainty of evidence supported that certain PFASs were associated with the incidence of low birth weight, low efficiency of the tetanus vaccine, and low triglyceride levels.

Distinctive presentation of neurobrucellosis as myelitis: A case report and literature review.

ABSTRACT: Brucellosis is a zoonotic infectious allergic disease caused by Brucella that is widely distributed throughout the world. Brucella can invade various systems of the human body, such as the joints, the reproductive system, the spine, and the nervous system. Among patients with brucellosis, neurobrucellosis (NB) mainly manifests as nervous system symptoms in only 1.7-10% of patients and can cause a misdiagnosis. We reported a case of NB that presented as myelitis as the main clinical presentation and reviewed the relevant literature. It is suggested that clinicians should consider NB, especially atypical neurological symptoms, when there is a suspicious contact history.

Advances in co-pathogenesis of the united airway diseases.

According to the concept of "united airway diseases", the airway is a single organ in which upper and lower airway diseases are commonly comorbid. A range of inflammatory factors have been found to play an important role in the chain reaction of upper and lower airway diseases. However, the amount of research on this concept remains limited. The underlying mechanism of the relationship between typical diseases of the united airway, such as asthma, allergic rhinitis, and chronic sinusitis, also needs to be further explored. This review highlights the interaction between upper and lower respiratory diseases gathered from epidemiological, histoembryology, neural mechanistic, microbiological, and clinical studies, revealing the relationship between the upper and lower respiratory tracts.

Breviscapine attenuates lead­induced myocardial injury by activating the Nrf2 signaling pathway.

The present study investigated the therapeutic potential of breviscapine (Bre) in mitigating lead (Pb)-induced myocardial injury through activation of the nuclear factor erythroid-2 related factor 2 (Nrf2) pathway. Rat cardiomyocytes (H9C2 cells) were exposed to Pb to model Pb poisoning, and various parameters, including cell viability, apoptosis and reactive oxygen species (ROS) production, were assessed using Cell Counting Kit-8, flow cytometry and 2',7'-dichlorfluoresceindiacetate assays, respectively. Additionally, a rat model of Pb poisoning was established in which blood Pb levels were measured using a graphite furnace atomic absorption spectrophotometer, and alterations in myocardial tissue, oxidative stress markers, inflammatory indicators, protein expression related to apoptosis and the Nrf2 pathway were evaluated via histopathology, ELISA and western blotting. The results showed that Bre treatment enhanced cell viability, decreased apoptosis, and reduced ROS production in Pb-exposed H9C2 cells. Moreover, Bre modulated oxidative stress markers and inflammatory factors while enhancing the expression of proteins in the Nrf2 pathway. In a rat model, Bre mitigated the lead-induced increase in blood Pb levels and myocardial injury biomarkers, and reversed the downregulation of Nrf2 pathway proteins. In conclusion, the current findings suggested that Bre mitigates Pb-induced myocardial injury by activating the Nrf2 signaling pathway, highlighting its potential as a therapeutic agent for protecting the heart from the harmful effects of Pb exposure. Further research is required to elucidate the exact mechanisms and explore the clinical applicability of Bre in mitigating Pb-induced myocardial damage.

Dupilumab in chronic rhinosinusitis with nasal polyposis: current status, challenges, and future perspectives.

INTRODUCTION: Chronic sinusitis with nasal polyposis (CRSwNP) is a common heterogeneous disease that mainly manifests as chronic inflammation of the sinus mucosa. The effect of conventional treatments for CRSwNP, such as oral corticosteroids, intranasal corticosteroids (INCS) and polypectomy, is not always obvious, and postoperative recurrence is common in some CRSwNP patients. In recent years, some biologics have been shown to be very effective in treating refractory CRSwNP, of which dupilumab has attracted much attention as the first monoclonal drug approved to treat nasal polyps. AREAS COVERED: In this review, we discuss the research status of dupilumab in treatment of CRSwNP and how dupilumab differs from other treatment methods. EXPERT OPINION: The European Union and United States have approved dupilumab as the first biological agent for treatment of CRSwNP. Dupilumab can improve symptoms of nasal congestion or obstruction, nasal secretion, and olfactory loss in patients with CRSwNP. It can also improve a patient's health-related quality of life (HR-QoL) and reduce the need for systemic corticosteroids and nasal polyp surgery. While subcutaneous injection of dupilumab is a novel method for treating CRSwNP, it is still necessary to reasonably evaluate which patients might benefit most from biological therapy.

Ovarian Cancer and Parkinson's Disease: A Bidirectional Mendelian Randomization Study.

(1) Background: Ovarian cancer (OC) and Parkinson's disease (PD) represent a huge public health burden. The relationship of these two diseases is suggested in the literature while not fully understood. To better understand this relationship, we conducted a bidirectional Mendelian ran-domization analysis using genetic markers as a proxy. (2) Methods: Utilizing single nucleotide polymorphisms associated with PD risk, we assessed the association between genetically predicted PD and OC risk, overall and by histotypes, using summary statistics from previously conducted genome-wide association studies of OC within the Ovarian Cancer Association Consortium. Similarly, we assessed the association between genetically predicted OC and PD risk. The inverse variance weighted method was used as the main method to estimate odds ratios (OR) and 95% confidence intervals (CI) for the associations of interest. (3) Results: There was no significant association between genetically predicted PD and OC risk: OR = 0.95 (95% CI: 0.88-1.03), or between genetically predicted OC and PD risk: OR = 0.80 (95% CI: 0.61-1.06). On the other hand, when examined by histotypes, a suggestive inverse association was observed between genetically predicted high grade serous OC and PD risk: OR = 0.91 (95% CI: 0.84-0.99). (4) Conclusions: Overall, our study did not observe a strong genetic association between PD and OC, but the observed potential association between high grade serous OC and reduced PD risk warrants further investigation.

PM2.5 exposure and its interaction of oxidative balance score on ovarian cancer survival: A prospective cohort study.

Recent evidence advises particles with a diameter of 2.5 µm or less (PM2.5) might be a prognostic factor for ovarian cancer (OC) survival. The oxidative balance score (OBS) incorporates diet-lifestyle factors to estimate individuals' anti-oxidant exposure status which may be relevant to cancer prognosis. We aimed to investigate the roles of PM2.5, and OBS and their interaction in OC prognosis. 663 patients with OC were enrolled in the current study. Satellite-derived annual average exposures to PM2.5 based on patients' residential locations. The OBS was calculated based on 16 different diet-lifestyle components derived using an acknowledged self-reported questionnaire. The Cox regression model was performed to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival (OS). We also assessed the effect of modification between PM2.5 and OS by OBS via interaction terms. During a median follow-up of 37.57 (interquartile:35.27-40.17) months, 123 patients died. Compared to low-concentration PM2.5 exposure, high PM2.5 during 1 year before diagnosis was associated with worse OC survival (HR= 1.19, 95% CI = 1.01-1.42). We observed an improved OS with the highest compared with the lowest OBS (HR = 0.46, 95% CI = 0.27-0.79, P for trend < 0.05). Notably, we also found an additive interaction between low OBS and high exposure to PM2.5, with the corresponding associations of PM2.5 being more pronounced among participants with lower OBS (HR = 1.42, 95% CI = 1.09-1.86). PM2.5 may blunt OC survival, but high OBS represented an antioxidative performance that could alleviate the adverse association of PM2.5 and OS.

Global Learnable Attention for Single Image Super-Resolution.

Self-similarity is valuable to the exploration of non-local textures in single image super-resolution (SISR). Researchers usually assume that the importance of non-local textures is positively related to their similarity scores. In this paper, we surprisingly found that when repairing severely damaged query textures, some non-local textures with low-similarity which are closer to the target can provide more accurate and richer details than the high-similarity ones. In these cases, low-similarity does not mean inferior but is usually caused by different scales or orientations. Utilizing this finding, we proposed a Global Learnable Attention (GLA) to adaptively modify similarity scores of non-local textures during training instead of only using a fixed similarity scoring function such as the dot product. The proposed GLA can explore non-local textures with low-similarity but more accurate details to repair severely damaged textures. Furthermore, we propose to adopt Super-Bit Locality-Sensitive Hashing (SB-LSH) as a preprocessing method for our GLA. With the SB-LSH, the computational complexity of our GLA is reduced from quadratic to asymptotic linear with respect to the image size. In addition, the proposed GLA can be integrated into existing deep SISR models as an efficient general building block. Based on the GLA, we constructed a Deep Learnable Similarity Network (DLSN), which achieves state-of-the-art performance for SISR tasks of different degradation types (e.g., blur and noise). Our code and a pre-trained DLSN have been uploaded to GitHub† for validation.

Evaluation of 30% supramolecular salicylic acid followed by 1565-nm non-ablative fractional laser on facial acne and subsequent enlarged pores.

The treatment of acne vulgaris and enlarged pore remains challenging. The 30% supramolecular salicylic acid (SSA) is a newly developed form of SA which affects pathogenic factors of acne. Non-ablative fractional laser (NAFL) promotes remodeling and decreases sebum excretion with minimal side effect. The current study was aimed to evaluate the sequential modality with 30% SSA followed by 1565-nm NAFL on facial acne and subsequent enlarged pores. A 20-week-duration prospective study was performed. Consecutive 4 sessions of 30% SSA treatment were conducted, at 2-week intervals. Two weeks after the last session of 30% SSA, 3 sessions of 1565-nm NAFL treatment were applied, at 4-week intervals. The noninvasive devices measured scores of red areas and pores, cuticle moisture, and sebum secretion. The main subjective evaluation was global acne grading system (GAGS). The side effects were recorded. Compared to baseline, the scores of red areas and pores, sebum secretion, and GAGS significantly decreased after series sessions of 30% SSA treatments (P < 0.05). The sequential application of 1565-nm NAFL maintained the good results (P < 0.05, comparing to baseline) and even further decreased the sebum secretion (P < 0.05, comparing to SSA). The cuticle moisture remained unchanged during whole period, and side effects including tingling sensation, pain, erythema, and edema were quickly reversible and acceptable. The significant improvements of acne and pores were produced by 30% SSA, and 1565-nm NAFL inhibited the sebum secretion and maintained the efficacies of 30% SSA. The sequential modality of 30% SSA followed by 1565-nm NAFL was an alternative choice for acne vulgaris companied with enlarged pores.

Proteomics and metabolomics analysis of nasal lavage fluid in chronic rhinosinusitis with nasal polyps.

KEY POINTS: An integrated proteomics and metabolomics were used to investigate the pathogenesis of CRSwNP. Amino acid metabolism and mitochondrial dysfunction play key roles in the pathogenesis of CRSwNP.

Association between pre-diagnostic dietary antioxidant vitamin consumption and ovarian cancer survival: a prospective cohort study.

Background: Epidemiological evidence regarding the relationship between dietary antioxidant vitamin intake and ovarian cancer (OC) survival is not clear. Herein, we aimed to first evaluate this topic in a prospective cohort study in China. Methods: The present study included participants from the Ovarian Cancer Follow-Up Study, which was a hospital-based prospective cohort study including OC patients who were aged 18 to 79 years during 2015-2020. The information on the intake of antioxidant vitamins, consisting of vitamin A, retinol, α-carotene, ß-carotene, vitamin C, and vitamin E, and other diet information was obtained through a 111-item food frequency questionnaire. Deaths were recorded until March 31, 2021. Hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival were evaluated using Cox proportional hazards models. Results: There were 130 (18.49%) deaths among 703 OC patients during a median 37.19 months follow-up. In the multivariable-adjusted model, the highest tertile of dietary vitamin C (HR = 0.43, 95% CI = 0.25-0.75, P for trend <0.05) and ß-carotene intake (HR = 0.52, 95% CI = 0.31-0.87, P for trend <0.05) was inversely associated with the overall survival of OC when compared with the lowest tertile group. Retinol, vitamin A, vitamin E, and α-carotene consumption showed no association with OC survival. Of note is that the multiplicative interaction was identified between vitamin C intake and residual lesions in OC survival (P for interaction <0.05). Conclusion: Our findings indicate that pre-diagnostic higher vitamin C and ß-carotene intake was associated with improved OC survival.

Association between pre-diagnostic dietary copper, zinc, and copper-to-zinc ratio and severity of ovarian cancer.

Background: The impact of dietary trace elements intake on ovarian cancer (OC) severity is unknown. Objective: We firstly explore the relationship between dietary copper (Cu), zinc (Zn), and copper-to-zinc (Cu/Zn) ratio and severity of OC. Methods: This cross-sectional study included 701 women from the OC follow-up study between 2015 and 2020. Dietary information was collected by a validated food frequency questionnaire (FFQ). The severity information of OC including age at diagnosis, histological type, International Federation of Gynecology and Obstetrics (FIGO) stage, and histopathologic grade was ascertained from medical records. Logistic regression model was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of aforementioned associations. Results: Among 701 participants, the number of patients age at diagnosis older than 50 were 443 (63.2%). The number of patients diagnosed as serous, III-IV stage, and poorly differentiation OC were 477 (68.05%), 336 (47.93%), and 597 (85.16%), respectively. In addition, compared with the lowest tertile intake, higher possibility of non-serous OC was associated with the pre-diagnosis dietary Cu (OR = 2.39, 95% CI = 1.28-4.47, p trend < 0.05) and Cu/Zn ratio (OR = 2.06, 95% CI = 1.26-3.39, P trend < 0.05) in the highest tertile intake. The risk of poorly differentiation OC at diagnosis was significant inversely related to dietary Cu intake (OR = 0.40, 95% CI = 0.18-0.88, P trend < 0.05). Besides, the results of subgroup analyses were consistent with the main findings but not all of them showed statistical significance. Conclusion: Pre-diagnostic dietary Cu and Cu/Zn ratio were contributed to reducing the severity of OC at diagnosis, especially for the risk of serous OC and poorly differentiation OC.

Identification of novel candidate genes and predicted miRNAs in atopic dermatitis patients by bioinformatic methods.

Atopic dermatitis (AD) is a common, chronic inflammatory dermatosis with relapsing eruptions. Our study used bioinformatics to find novel candidate differentially expressed genes (DEGs) and predicted miRNAs between AD patients and healthy controls. The Mesh term "atopic dermatitis" was retrieved to obtain DEGs in GEO datasets. DEGs between AD patients and healthy controls were analyzed using GEO2R. Overlapping DEGs between different datasets were obtained with use of Draw Venn software. GO and KEGG enrichment analyses were conducted by the use of DAVID. STRING and miRWalk were used to individually analyze PPI networks, interactions of candidate genes and predicted miRNAs. A total of 571 skin samples, as retrieved from 9 databases were assessed. There were 225 overlapping DEGs between lesioned skin samples of AD patients and that of healthy controls. Nineteen nodes and 160 edges were found in the largest PPI cluster, consisting of 17 up-regulated and 2 down-regulated nodes. Two KEGG pathways were identified, including the cell cycle (CCNB1, CHEK1, BUB1B, MCM5) and p53 (CCNB1, CHEK1, GTSE1) pathways. There were 56 nodes and 100 edges obtained in the miRNA-target gene network, with has-miR-17-5p targeted to 4 genes and has-miR-106b-5p targeted to 3 genes. While these findings will require further verification as achieved with experiments involving in vivo and in vitro modles, these results provided some initial insights into dysfunctional inflammatory and immune responses associated with AD. Such information offers the potential to develop novel therapeutic targets for use in preventing and treating AD.

Parity and Metabolic Syndrome Risk: A Systematic Review and Meta-Analysis of 15 Observational Studies With 62,095 Women.

Background: Epidemiological studies have provided inconsistent evidence of the association between parity and metabolic syndrome (MetS) risk. We conducted this first systematic review and meta-analysis to comprehensively and precisely quantify this topic. Methods: Comprehensive searches of PubMed, Embase, and the Web of Science databases were conducted to identify observational studies of the association between parity and MetS risk up to 30 January 2022. Study inclusion, data extraction, and quality assessment were checked and reviewed by two investigators independently. Random-effects models were applied to estimate pooled odds ratios (ORs) and 95% CIs. This study has been registered with PROSPERO. Results: Two high-quality cohorts and thirteen medium-quality cross-sectional studies involving 62,095 women were finally included. Compared with the nulliparous, the pooled OR of MetS for the ever parity was 1.31 (95% CI = 0.91-1.88, I 2 = 72.6%, n = 3). Compared with the lowest parity number, the pooled OR of MetS for the highest parity number was 1.38 (95% CI = 1.22-1.57, I 2 = 60.7%, n = 12). For the dose-response analysis, the pooled OR of MetS for each increment of one live birth was 1.12 (95% CI = 1.05-1.19, I 2 = 78.6%, n = 6). These findings were robust across subgroups and sensitivity analyses. No evidence of heterogeneity between subgroups was indicated by meta-regression analyses. Conclusion: The findings suggested that parity was associated with an increased risk of MetS. A sufficient number of large prospective cohort studies are required to fully verify our findings. Systematic Review Registration: [https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42022307703].

Electroencephalography (EEG)-Based Neural Emotional Response to Flower Arrangements (FAs) on Normal Elderly (NE) and Cognitively Impaired Elderly (CIE).

BACKGROUND: The purpose of this study is to explore the differences and similarities of EEG -based neural emotional response toward flower arrangements (FAs) between the normal elderly (NE) and cognitively impaired elderly (CIE) in arranging flowers. METHODS: The study participants included 16 elderly individuals: eight elderly people with normal cognitive function and eight elderly people with cognitive dysfunction. They were divided into two groups to arrange flowers, and six mood indicators (Engagement, Excitation, Focus, Interest, Relaxation and Stress) were measured with EEG before and after the experiment. RESULTS: The similarities were that there was no significant difference in Excitement, Relaxation and Stress between pre-test and post-test for NE and CIE. The differences were that there was a significant difference on Engagement and Interest in CIE, and they both increased, but there was no difference with respect to them in NE. While there was a significant difference on the Focus of NE, it was decreased, but there was no difference for it with respect to CIE. CONCLUSIONS: A similarity on EEG-Based Neural Emotional Responses to flower arrangements between NE and CIE was that they both felt relaxation. The differences were that the Focus of NE decreased and the Interest and Engagement of CIE increased. CIEs were more interested and engaged in FAs.

Automatic Intermediate Generation With Deep Reinforcement Learning for Robust Two-Exposure Image Fusion.

Fusing low dynamic range (LDR) for high dynamic range (HDR) images has gained a lot of attention, especially to achieve real-world application significance when the hardware resources are limited to capture images with different exposure times. However, existing HDR image generation by picking the best parts from each LDR image often yields unsatisfactory results due to either the lack of input images or well-exposed contents. To overcome this limitation, we model the HDR image generation process in two-exposure fusion as a deep reinforcement learning problem and learn an online compensating representation to fuse with LDR inputs for HDR image generation. Moreover, we build a two-exposure dataset with reference HDR images from a public multiexposure dataset that has not yet been normalized to train and evaluate the proposed model. By assessing the built dataset, we show that our reinforcement HDR image generation significantly outperforms other competing methods under different challenging scenarios, even with limited well-exposed contents. More experimental results on a no-reference multiexposure image dataset demonstrate the generality and effectiveness of the proposed model. To the best of our knowledge, this is the first work to use a reinforcement-learning-based framework for an online compensating representation in two-exposure image fusion.

Bioinspired Multifunctional Cellulose Nanofibril-Based In Situ Liquid Wound Dressing for Multiple Synergistic Therapy of the Postoperative Infected Wound.

A smart in situ-formed wound dressing with excellent antibacterial ability against drug-resistance bacterial, antitumor, and biofilm-eliminating activities to promote effective wound closure is highly desirable in therapeutic and clinical applications. Herein, we designed and developed a multifunctional; shape-adaptable; and pH, temperature, and near-infrared radiation (NIR) multiple responsive cellulose nanofibril (CNF)-based in situ liquid wound dressing, using a pH-sensitive CNF grafted with terminated amino hyperbranched polyamines (HBP-NH2) as a substrate, along with poly(N-isopropylacrylamide) and indocyanine green (ICG) loaded as the temperature and NIR on/off switches, respectively. The 3D nanocage network structure of CNF and the nanocavities in the hyperbranched structure of HBP-NH2 endow the dressing with a high loading capacity for active drugs (doxorubicin and ICG) simultaneously. Moreover, the responsiveness of the dressing to multiple stimuli enables controllable and efficient drug release to the wound area. The bioinspired dressing demonstrates excellent antibacterial activity against common bacteria and methicillin-resistant Staphylococcus aureus, antitumor activity against A375 tumor cells, and biofilm-eliminating capability. In addition, the developed dressing synergistically combines multiple therapeutic strategies for effective wound healing, specifically photothermal therapy, photodynamic therapy, and chemotherapy. The design provides an ideal clinical intervention strategy for irregular tumor postoperative infected wounds.

Advances in scarless foetal wound healing and prospects for scar reduction in adults.

Healing after mammalian skin injury involves the interaction between numerous cellular constituents and regulatory factors, which together form three overlapping phases: an inflammatory response, a proliferation phase and a remodelling phase. Any slight variation in these three stages can substantially alter the healing process and resultant production of scars. Of particular significance are the mechanisms responsible for the scar-free phenomenon observed in the foetus. Uncovering such mechanisms would offer great expectations in the treatment of scars and therefore represents an important area of investigation. In this review, we provide a comprehensive summary of studies on injury-induced skin regeneration within the foetus. The information contained in these studies provides an opportunity for new insights into the treatment of clinical scars based on the cellular and molecular processes involved.