Optimization of duplex digital PCR for the measurement of SARS-CoV-2 RNA.

Quantitative PCR (qPCR) is the gold standard for detecting nucleic acid sequences specific to the target pathogen. For COVID-19 diagnosis, several molecular assays have been developed. In this study, we present an optimization strategy for the measurement of SARS-CoV-2 RNA via multiplex qPCR and digital PCR (dPCR). Compared to qPCR, both droplet and chip-based dPCR, which are known to be more sensitive and accurate, showed a better resilience to suboptimal assay compositions and cycling conditions following the proposed optimizations. In particular, the formation of heterodimers among assays greatly interfered with qPCR results, but only minimally with dPCR results. In dPCR, existing heterodimers lowered the PCR efficiency, producing a dampened fluorescent signal in positive partitions. This can be corrected by adjusting the PCR cycling conditions, after which dPCR shows the capability of measuring the expected copy number. In addition, we present a process to improve the existing RdRp assay by correcting the primer sequences and matching the melting temperature, ultimately producing highly sensitive and robust assays. The results of this study can reduce the cost and time of SARS-CoV-2 diagnosis while increasing accuracy. Furthermore, our results suggest that dPCR is a reliable method for the accurate measurement of nucleic acid targets.

Cathepsin C regulates tumor progression via the Yes-associated protein signaling pathway in non-small cell lung cancer.

Cathepsin C (CTSC), also known as dipeptidyl peptidase I, is a cathepsin with lysosomal exocysteine protease activity and a central coordinator for the activation of neutrophil-derived serine proteases in the lysosomes of neutrophils. Although the role of CTSC in various cancers, including liver and breast cancers, has recently been reported, its role in non-small cell lung cancer (NSCLC) is largely unknown. This study aimed to investigate the functional role of CTSC in NSCLC and the molecular mechanisms underlying CTSC involvement in disease progression. CTSC overexpression markedly enhanced the growth, motility, and invasiveness of NSCLC cells in vitro and in vivo. CTSC knockdown using shRNA in NSCLC cells reversed the migratory and invasive behavior of NSCLC cells. CTSC also induced epithelial-mesenchymal transition through the Yes-associated protein signaling pathway. In addition, our analyses of clinical samples confirmed that high CTSC expression was associated with lymph node metastasis and recurrence in lung adenocarcinoma. In conclusion, CTSC plays an important role in the progression of NSCLC. Thus, targeting CTSC may be a promising treatment option for patients with NSCLC.

The Matrix Stiffness Coordinates the Cell Proliferation and PD-L1 Expression via YAP in Lung Adenocarcinoma.

The extracellular matrix (ECM) exerts physiological activity, facilitates cell-to-cell communication, promotes cell proliferation and metastasis, and provides mechanical support for tumor cells. The development of solid tumors is often associated with increased stiffness. A stiff ECM promotes mechanotransduction, and the predominant transcription factors implicated in this phenomenon are YAP/TAZ, ß-catenin, and NF-κB. In this study, we aimed to investigate whether YAP is a critical mediator linking matrix stiffness and PD-L1 in lung adenocarcinoma. We confirmed that YAP, PD-L1, and Ki-67, a marker of cell proliferation, increase as the matrix stiffness increases in vitro using the lung adenocarcinoma cell lines PC9 and HCC827 cells. The knockdown of YAP decreased the expression of PD-L1 and Ki-67, and conversely, the overexpression of YAP increased the expression of PD-L1 and K-67 in a stiff-matrix environment (20.0 kPa). Additionally, lung cancer cells were cultured in a 3D environment, which provides a more physiologically relevant setting, and compared to the results obtained from 2D culture. Similar to the findings in 2D culture, it was confirmed that YAP influenced the expression of PD-L1 and K-67 in the 3D culture experiment. Our results suggest that matrix stiffness controls PD-L1 expression via YAP activation, ultimately contributing to cell proliferation.

Novel Organoid Culture System for Improved Safety Assessment of Nanomaterials.

Over the past few decades, the increased application of nanomaterials has raised questions regarding their safety and possible toxic effects. Organoids have been suggested as promising tools, offering efficient assays for nanomaterial-induced toxicity evaluation. However, organoid systems have some limitations, such as size heterogeneity and poor penetration of nanoparticles because of the extracellular matrix, which is necessary for organoid culture. Here, we developed a novel system for the improved safety assessment of nanomaterials by establishing a 3D floating organoid paradigm. In addition to overcoming the limitations of two-dimensional systems including the lack of in vitro-in vivo cross-talk, our method provides multiple benefits as compared with conventional organoid systems that rely on an extracellular matrix for culture. Organoids cultured using our method exhibited relatively uniform sizing and structural integrity and were more conducive to the internalization of nanoparticles. Our floating culture system will accelerate the research and development of safe nanomaterials.

Prediction of lung cancer using novel biomarkers based on microbiome profiling of bronchoalveolar lavage fluid.

There is an unmet need for biomarkers for the diagnosis of lung cancer and decision criteria for lung biopsy. We comparatively investigated the lung microbiomes of patients with lung cancer and benign lung diseases. Patients who underwent bronchoscopy at Chungnam National University Hospital between June 2021 and June 2022 were enrolled. Bronchoalveolar lavage fluid (BALF) was collected from 24 patients each with lung cancer and benign lung diseases. The samples were analyzed using 16S rRNA-based metagenomic sequencing. We found that alpha diversity and the beta diversity distribution (P = 0.001) differed significantly between patients with benign lung diseases and those with lung cancer. Firmicutes was the most abundant phylum in patients with lung cancer (33.39% ± 17.439), whereas Bacteroidota was the most abundant phylum in patients with benign lung disease (31.132% ± 22.505), respectively. In differential abundance analysis, the most differentially abundant microbiota taxon was unclassified_SAR202_clade, belonging to the phylum Chloroflexi. The established prediction model distinguished patients with benign lung disease from those with lung cancer with a high accuracy (micro area under the curve [AUC] = 0.98 and macro AUC = 0.99). The BALF microbiome may be a novel biomarker for the detection of lung cancer.

Factors associated with the download and use of mobile personal health record applications in Korean hospitals.

The use of mobile personal health records (m-PHR) has been little studied at the organizational level. This study was to investigate the relationships of various hospital-related factors with m-PHR use in Korean hospitals. Downloads of m-PHR applications for 101 hospitals were examined from May 26 to 30 June 2022. The dependent variable was the number of m-PHR downloads, and the major independent variables included six technological, organizational, and environmental factors. As technological factors, the number of computed tomography and magnetic resonance imagery devices were significantly associated with downloads (RR = 1.119, CI = 1.022-1.226, p = 0.016; and RR = 1.155; 95% CI = 1.024-1.302, p = 0.019, respectively). At the organizational level, the number of physicians, adjusting for the number of beds, and the number of medical information management staff showed significant associations (RR = 1.059, CI = 1.019-1.100, p = 0.004; and RR = 1.026, CI = 1.002-1.050, p = 0.033, respectively). From an environmental standpoint, downloads were positively associated with the proportion of the local population of working age (20-59 years) (RR = 1.102, CI 1.022-1.189, p = 0.012). Healthcare policymakers should pay close attention to these factors to advocate for the widespread use of m-PHR applications.

Comparison of progression-free survival outcome of sentinel node biopsy without ultrastaging versus lymphadenectomy in endometrial cancer: a propensity-matched analysis.

OBJECTIVE: We aimed to investigate the oncologic outcomes of patients with endometrial cancer who underwent sentinel lymph node (SLN) biopsy without ultrastaging compared with that of those who underwent lymphadenectomy (LND). METHODS: Patients with endometrial cancer who underwent staging with SLN biopsy or LND during 2006 - 2021 were analyzed using propensity score matching (PSM). SLN metastasis was examined using hematoxylin and eosin staining, without ultrastaging. Progression-free survival (PFS) was compared between the two groups before and after PSM using age, histology, and stage as covariates. Clinical variables such as recurrence patterns and lymphatic complications, were assessed. RESULTS: After excluding 213 patients who underwent validation LND with SLN biopsy, 902 were identified. The demographics of the remaining patients differed according to histology, myometrial invasion depth, and stage. Lymph node metastasis was less frequent in the SLN group than in the LND group (9.4% vs. 3.8%, p=0.004). The recurrence rates within 2 years were lower in the SLN group. The SLN group exhibited significantly superior 2-year and overall PFS than the LND group. Among patients with uterus-confined disease, overall PFS was favorable for SLN biopsy. After matching, differences in PFS were no longer observed, although the lymphocele and lymphedema rates were significantly lower in the SLN group. CONCLUSION: In patients with endometrial cancer, SLN biopsy without ultrastaging did not compromise survival outcomes and was associated with significantly reduced lymphatic complication rates compared with LND. Therefore, SLN biopsy can be recommended for patients with endometrial cancer without definitive preoperative evidence of distant metastasis.

Establishment of a TNFRSF11B knock-out human induced pluripotent stem cell line (KSCBi002-B-2) via CRISPR/Cas9 system.

A TNFRSF11B (TNF Receptor Superfamily Member 11b) gene encodes a soluble decoy receptor, osteoprotegerin (OPG), which has a key role in repressing osteoclast differentiation. In this report, we generated a biallelic knock-out hiPSC line for the TNFRSF11B gene via CRISPR/Cas9. When TNFRSF11B Knock-out hiPSCs were differentiated into mesenchymal progenitor cells (MPCs), the expression level of OPG was significantly decreased compared to normal hiPSC-derived MPCs. This knock-out hiPSCs will provide a chance to study Paget disease of bone 5 (juvenile Paget disease).

Cryobiopsy: A Breakthrough Strategy for Clinical Utilization of Lung Cancer Organoids.

One major challenge associated with lung cancer organoids (LCOs) is their predominant derivation from surgical specimens of patients with early-stage lung cancer. However, patients with advanced lung cancer, who are in need of chemotherapy, often cannot undergo surgery. Therefore, there is an urgent need to successfully generate LCOs from biopsy specimens. Conventional lung biopsy techniques, such as transthoracic needle biopsy and forceps biopsy, only yield small amounts of lung tissue, resulting in a low success rate for culturing LCOs from biopsy samples. Furthermore, potential complications, like bleeding and pneumothorax, make it difficult to obtain sufficient tissue. Another critical issue is the overgrowth of normal lung cells in later passages of LCO culture, and the optimal culture conditions for LCOs are yet to be determined. To address these limitations, we attempted to create LCOs from cryobiopsy specimens obtained from patients with lung cancer (n = 113). Overall, the initial success rate of establishing LCOs from cryobiopsy samples was 40.7% (n = 46). Transbronchial cryobiopsy enables the retrieval of significantly larger amounts of lung tissue than bronchoscopic forceps biopsy. Additionally, cryobiopsy can be employed for peripheral lesions, and it is aided via radial endobronchial ultrasonography. This study significantly improved the success rate of LCO culture and demonstrated that the LCOs retained characteristics that resembled the primary tumors. Single-cell RNA sequencing confirmed high cancer cell purity in early passages of LCOs derived from patients with advanced lung cancer. Furthermore, the three-dimensional structure and intracellular components of LCOs were characterized using three-dimensional holotomography. Finally, drug screening was performed using a specialized micropillar culture system with cryobiopsy-derived LCOs. LCOs derived from cryobiopsy specimens offer a promising solution to the critical limitations of conventional LCOs. Cryobiopsy can be applied to patients with lung cancer at all stages, including those with peripheral lesions, and can provide sufficient cells for LCO generation. Therefore, we anticipate that cryobiopsy will serve as a breakthrough strategy for the clinical application of LCOs in all stages of lung cancer.

Virus-templated redox nanowire network for enzyme electrode.

Viruses have unique coat proteins that are genetically modifiable. Their surface can serve as a nano-template on which electroactive molecules are immobilized. In this study, we report filamentous bacteriophage as a backbone to which redox mediators are covalently and densely tethered, constructing redox nanowire, i.e. an electron conducting biomaterial. The highly ordered coat proteins of a filamentous bacteriophage provide flexible and biocompatible platform to constitute a biohybrid redox nanowire. Incorporating bacteriophage and redox molecules form an entangled assembly of nanowires enabling facile electron transfer. Electron transfer among the molecular mediators in the entangled assembly originates apparent electron diffusion of which the electron transfer rate is comparable to that observed in conventional redox polymers. Programming peptide terminals suggests further enhancement in electron mediation by increasing redox species mobility. In addition, the redox nanowire film functions as a favorable matrix for enzyme encapsulation. The stability of the enzymes entrapped in this unique matrix is substantially improved.

Dynamic changes in pathology and PD-L1 expression in a patient with metastatic lung adenocarcinoma who received pembrolizumab therapy followed by two salvage surgeries two years later: A case report.

During chemotherapy, certain cancer cells undergo cell death, which alters the properties of remaining cells and leads to numerous changes in the constituent cells of lung cancer. Immunotherapy has been used as neoadjuvant therapy, and several studies have reported changes in lung cancer tissue following treatment with immuno-anticancer drugs in early stage disease. However, no research has currently discussed the pathological and PD-L1 expression changes in metastatic lung cancer. Here, we describe a patient with lung adenocarcinoma and multiple metastases who achieved complete remission after receiving initial carboplatin/pemetrexed followed by pembrolizumab treatment for 2-years. The initial biopsy revealed adenocarcinoma with high PD-L1 expression, and next-generation sequencing (NGS) identified KRAS, RBM10, and STAG2 mutations. After 2-years of treatment with pembrolizumab, the patient achieved complete response (CR). The patient underwent first salvage surgery for the oligo-relapse lesion, and the pathology result showed a large cell neuroendocrine tumor (NET) with adenocarcinoma and no PD-L1 expression. NGS revealed KRAS and TP53 mutations. After one year, a chest computed tomography (CT) scan revealed a small nodule in the right lower lobe, and the patient underwent second salvage surgery. Pathology results showed minimally invasive adenocarcinoma with no PD-L1 expression and no significant genetic mutations. This case report demonstrates the dynamic changes cancer cells undergo following pembrolizumab treatment and salvage surgeries and is the first report to compare pathological changes after immunotherapy and two subsequent salvage surgeries in metastatic lung adenocarcinoma. Clinicians must remain vigilant to these dynamic changes throughout treatment and consider salvage surgery for oligo-relapse lesions. By understanding these changes, new strategies can be developed to improve the long-term efficacy of immunotherapy.

Scientific evidence of foods that improve the lifespan and healthspan of different organisms.

Age is a risk factor for numerous diseases. Although the development of modern medicine has greatly extended the human lifespan, the duration of relatively healthy old age, or 'healthspan', has not increased. Targeting the detrimental processes that can occur before the onset of age-related diseases can greatly improve health and lifespan. Healthspan is significantly affected by what, when and how much one eats. Dietary restriction, including calorie restriction, fasting or fasting-mimicking diets, to extend both lifespan and healthspan has recently attracted much attention. However, direct scientific evidence that consuming specific foods extends the lifespan and healthspan seems lacking. Here, we synthesized the results of recent studies on the lifespan and healthspan extension properties of foods and their phytochemicals in various organisms to confirm how far the scientific research on the effect of food on the lifespan has reached.

A pilot randomized clinical trial of biomedical link with mental health in art therapy intervention programs for alcohol use disorder: Changes in NK cells, addiction biomarkers, electroencephalography, and MMPI-2 profiles.

OBJECTIVE: Alcohol intake is a major risk factor for various diseases. Elucidating alcohol use disorder (AUD) is important in preventing diseases and promoting health. We aimed to investigate the effect of art therapy on emotional (Minnesota Multiphasic Personality Inventory-2 [MMPI-2]) and physical (natural killer [NK] cell count, expression of stress-associated proteins [SAP], and electroencephalography) changes in patients with AUD. METHODS: Participants were randomly divided into two groups (n = 35), with the experimental group undergoing art therapy involving weekly 60-min group therapy sessions for 10 weeks. Statistical analysis was performed using Ranked ANCOVA and Wilcoxon's signed rank test. Western blotting was performed to analyze serum SAP levels. RESULTS: We observed an association between psychological mechanisms and stress proteins. There was an increased number of NK cells in the experimental group after the program. Moreover, compared with the control group, the experimental group showed significant changes in SAP expression. Further, the experimental group showed a positive change in the MMPI-2 profile, as well as a decrease in depression, anxiety, impulsivity, and alcohol dependence. CONCLUSIONS: Continuous psychological support could be applied as a stress-control program for preventing stress recurrence and post-discharge relapse. Our findings strengthen the link between biomedical science and mental health in rehabilitation treatment for AUD.

A denoising model based on multi-agent reinforcement learning with data transformation for digital tomosynthesis.

Objective. Denoising models based on the supervised learning have been proposed for medical imaging. However, its clinical availability in digital tomosynthesis (DT) imaging is limited due to the necessity of a large amount of training data for providing acceptable image quality and the difficulty in minimizing a loss. Reinforcement learning (RL) can provide the optimal pollicy, which maximizes a reward, with a small amount of training data for implementing a task. In this study, we presented a denoising model based on the multi-agent RL for DT imaging in order to improve the performance of the machine learning-based denoising model.Approach. The proposed multi-agent RL network consisted of shared sub-network, value sub-network with a reward map convolution (RMC) technique and policy sub-network with a convolutional gated recurrent unit (convGRU). Each sub-network was designed for implementing feature extraction, reward calculation and action execution, respectively. The agents of the proposed network were assigned to each image pixel. The wavelet and Anscombe transformations were applied to DT images for delivering precise noise features during network training. The network training was implemented with the DT images obtained from the three-dimensional digital chest phantoms, which were constructed by using clinical CT images. The performance of the proposed denoising model was evaluated in terms of signal-to-noise ratio (SNR), structural similarity (SSIM) and peak signal-to-noise ratio (PSNR).Main results. Comparing the supervised learning, the proposed denoising model improved the SNRs of the output DT images by 20.64% while maintaining the similar SSIMs and PSNRs. In addition, the SNRs of the output DT images with the wavelet and Anscombe transformations were 25.88 and 42.95% higher than that for the supervised learning, respectively.Significance. The denoising model based on the multi-agent RL can provide high-quality DT images, and the proposed method enables the performance improvement of machine learning-based denoising models.

Antimicrobial activity of Limosilactobacillus fermentum strains isolated from the human oral cavity against Streptococcus mutans.

Oral probiotics have been recently gaining much attention owing to their potential to inhibit the progression of dental caries by controlling the cariogenic effects of Streptococcus mutans. We isolated and genotypically identified 77 lactic acid bacteria including 12 Limosilactobacillus fermentum probiotic candidates from the oral cavity of healthy volunteers. Among the 12 L. fermentum isolates, nine isolates effectively inhibited the growth of S. mutans via hydrogen peroxide (H2O2) production. The others neither suppressed the growth of S. mutans nor produced H2O2. Eight out of the nine H2O2-producing L. fermentum isolates exhibited strong adherence to oral epithelial KB cells while inhibiting the adherence of S. mutans to KB cells. The eight H2O2-producing isolates were neither haemolytic based on a blood-agar test, cytotoxic according to lactate dehydrogenase assay, nor resistant to eight antibiotics represented by the European Food Safety Authority guideline, indicating that the isolates have potential to suppress the cariogenesis driven by S. mutans while providing general probiotic benefits.

Redefining the role of AMPK in autophagy and the energy stress response.

Autophagy maintains cellular homeostasis during low energy states. According to the current understanding, glucose-depleted cells induce autophagy through AMPK, the primary energy-sensing kinase, to acquire energy for survival. However, contrary to the prevailing concept, our study demonstrates that AMPK inhibits ULK1, the kinase responsible for autophagy initiation, thereby suppressing autophagy. We found that glucose starvation suppresses amino acid starvation-induced stimulation of ULK1-Atg14-Vps34 signaling via AMPK activation. During an energy crisis caused by mitochondrial dysfunction, the LKB1-AMPK axis inhibits ULK1 activation and autophagy induction, even under amino acid starvation. Despite its inhibitory effect, AMPK protects the ULK1-associated autophagy machinery from caspase-mediated degradation during energy deficiency, preserving the cellular ability to initiate autophagy and restore homeostasis once the stress subsides. Our findings reveal that dual functions of AMPK, restraining abrupt induction of autophagy upon energy shortage while preserving essential autophagy components, are crucial to maintain cellular homeostasis and survival during energy stress.

Usefulness and potential pitfalls of pre-operative PET-CT in patients with endometrial cancer undergoing one- and two-step sentinel lymph node mapping: Do negative findings on PET-CT negativity really indicate node negativity?

OBJECTIVE: We investigated the utility of Positron emission tomography-Computed tomography (PET-CT) in the setting of two different sentinel lymph node (SLN) mapping techniques; the conventional cervical injection method (one-step) and the two-step method, which involves fundal injection followed by cervical injection. METHODS: Patients with endometrial cancer undergoing FDG PET-CT followed by laparoscopic or robotic surgical staging with SLN mapping at the Yonsei Cancer Center between July 2014 and April 2021 were stratified into the PET-positive group (with suspected or likely lymph nodes metastasis) and PET-negative group. A chart review was performed for the number of harvested SLNs, patterns of SLN metastases, and recurrence. RESULTS: Among 466 patients undergoing one-step (n = 276) and two-step (n = 190) SLN mapping, LN metastasis was identified in 21 of 434 PET-negative and 18 of 32 PET-positive patients. The sensitivity and specificity of PET-CT for diagnosing lymph node metastasis were 46.2% and 96.7%, respectively. Among PET-positive patients with LN metastasis, anatomical distribution was concordant in 14/18 patients (77.8%). Among PET-negative patients, four (2.3%) had metastatic para-aortic SLNs, including three (1.7%) with isolated para-aortic metastases; metastatic para-aortic SLNs were exclusively found in the two-step group. Among PET-positive patients, para-aortic SLN metastasis was identified in 35.7% of two-step and 16.7% of one-step group. Among the 21 PET false-negative patients, recurrence was seen in four patients (19%) after a median follow-up of 34 months (range: 7-70 months). CONCLUSIONS: PET-CT served as a useful guide to clinicians with high anatomical concordance rate in patients with LN metastasis. However, despite high specificity, sensitivity was limited. SLN metastasis pattern, especially at the para-aortic level, indicates that the two-step SLN technique might be useful in PET-negative and PET-positive patients.

STAT3 activation in microglia increases pericyte apoptosis in diabetic retinas through TNF-ɑ/AKT/p70S6 kinase signaling.

Diabetic retinopathy (DR) is one of the vascular complications associated with diabetes mellitus. Pericyte loss is an early characteristic phenomenon in DR. However, the mechanism by which pericyte apoptosis occurs in DR is not fully understood. We have focused on the increased STAT3 activation in diabetic retinas because STAT3 activation is associated with inflammation, and persistent chronic inflammation is closely related to retinal lesions. In this study, we demonstrated that STAT3 was activated by IFN-γ and IL-6 that highly expressed in diabetic retinas. We identified TNF-α as a potent inducer of pericyte apoptosis in diabetic retinas from the gene expression analysis and found that STAT3 activation in microglia increased TNF-α expression in the diabetic retinas. We also demonstrated that increased TNF-α expression in microglia caused pericyte apoptosis through downregulating AKT/p70S6 kinase signaling. Moreover, we took advantage of mice lacking STAT3 in microglia and demonstrated that STAT3 ablation in microglia reduced the pericyte apoptosis and TNF-α expression in the diabetic retinas. These results suggest that STAT3 activation in microglia plays an important role in pericyte apoptosis in the diabetic retinas through increased TNF-α expression and provide STAT3 activation in microglia as a potential therapeutic target for preventing pericyte loss in DR.

Association of antibiotics exposure within the first 2 years after birth with subsequent childhood type 1 diabetes.

PURPOSE: Antibiotics prescription in early life can cause dysbiosis, an imbalance of gut microbiota. We aimed to reveal the relationship between antibiotics exposure during the first 2 years after birth and type 1 diabetes risk in children under 8 years of age using a nationally representative data from South Korea. METHODS: The final study population consisted of 63,434 children from the National Health Insurance Service (NHIS) database from 2008 to 2015. The primary exposure of interest was antibiotics prescription in first 2 years after birth. The analysis was conducted with cumulative defined daily dose (cDDD; 0-29, 30-59, ≥ 60 cDDD), the number of antibiotics classes (0-3, 4, ≥5 classes), and age at first antibiotics prescription (0-119, 120-239, ≥ 240 days). Age, sex, household income, and overweight were considered as potential confounding covariates. RESULTS: Compared to those within the less than 30 cDDD, other groups that were prescribed more antibiotics did not have a significant difference in diabetes risk (aHR 0.86, 95% CI 0.37-2.02 in ≥ 60 cDDD). The number of antibiotics classes and age at first antibiotics prescriptions were also not associated with the risk of type 1 diabetes. The development of diabetes was not related to the cDDD, the number of antibiotics classes, and age at first antibiotics prescription according to subgroup analysis which was stratified by overweight. CONCLUSIONS: Antibiotics exposure within the first 2 years of life was not associated with subsequent diabetes risk. Future studies using a larger number of long-term follow-up data are needed.

Leaky Gum: The Revisited Origin of Systemic Diseases.

The oral cavity is the gateway for microorganisms into your body where they disseminate not only to the directly connected respiratory and digestive tracts but also to the many remote organs. Oral microbiota, travelling to the end of the intestine and circulating in our bodies through blood vessels, not only affect a gut microbiome profile but also lead to many systemic diseases. By gathering information accumulated from the era of focal infection theory to the age of revolution in microbiome research, we propose a pivotal role of "leaky gum", as an analogy of "leaky gut", to underscore the importance of the oral cavity in systemic health. The oral cavity has unique structures, the gingival sulcus (GS) and the junctional epithelium (JE) below the GS, which are rarely found anywhere else in our body. The JE is attached to the tooth enamel and cementum by hemidesmosome (HD), which is structurally weaker than desmosome and is, thus, vulnerable to microbial infiltration. In the GS, microbial biofilms can build up for life, unlike the biofilms on the skin and intestinal mucosa that fall off by the natural process. Thus, we emphasize that the GS and the JE are the weakest leaky point for microbes to invade the human body, making the leaky gum just as important as, or even more important than, the leaky gut.