[Correlation analysis between blood routine-derived inflammatory markers and respiratory function in pneumoconiosis patients]

Objective: To analyze the correlation between blood routine-derived inflammation indicators and respiratory function in patients with pneumoconiosis. Methods: In January 2021, 492 male pneumoconiosis patients hospitalized in Hefei Institute of Occupational Disease Control and Prevention from 2012 to 2020 were randomly selected as the case group, 492 dust exposed non pneumoconiosis workers who underwent occupational health examination at the same time were taken as the control group. The occupational history and clinical examination data of the two groups of subjects were collected, the correlation between blood routine-derived inflammatory indexes and pulmonary function and blood gas analysis was analyzed retrospectively. Results: Compared with the control group, the lymphocyte monocyte ratio (LMR) in the case group was decreased, and the neutrophil lymphocyte ratio (NLR) was increased, and the difference was statistically significant (P<0.05) . There were significant differences in forced vital capacity as a percentage of the predicted value (FVC) , forced expiratory volume in the first second as a percentage of the predicted value (FEV(1)%) , one second rate (FEV(1)/FVC) , partial pressure of oxygen (PaO(2)) , partial pressure of carbon dioxide (PaCO(2)) , and pH among pneumoconiosis patients at different stages (P<0.05) . FVC%, FEV(1)%, FEV(1)/FVC, and PaO(2) decreased with the increase of the stage, the trend test was statistically significant (tau-b=-0.24, -0.34, -0.37, -0.17, P<0.05) , PaCO(2) and pH increased with the increase of the stage, and the trend test was statistically significant (tau-b=0.10, 0.08, P<0.05) . There were statistically significant differences in LYM, LMR, NLR, platelet lymphocyte ratio (PLR) in patients with pneumoconiosis at different stages (P<0.05) , and LYM and LMR decreased with the increase of stage, trend test showed that there was statistically significant (tau-b=-0.11, -0.13, P<0.05) . There were significant differences in FVC%, FEV(1)%, FEV(1)/FVC, PaO(2), pH, LMR, NLR, PLR among patients with different types of pneumoconiosis (P<0.05) . LMR in pneumoconiosis patients was significantly positively correlated with FVC%, FEV(1)%, FEV(1)/FVC and PaO(2) (r(s)=0.342, 0.324, 0.203, 0.207, P<0.05) , NLR was significantly negatively correlated with FVC%, FEV(1)%, FEV(1)/FVC and PaO(2) (r(s)=-0.193, -0.202, -0.164, -0.177, P<0.05) , PLR was significantly negatively correlated with FVC%, FEV(1)%, FEV(1)/FVC and PaO(2) (r(s)=-0.194, -0.193, -0.106, -0.113, P<0.05) . Multiple linear regression analysis showed that LMR in pneumoconiosis patients was positively related with FVC%, FEV(1)% and PaO(2) (P<0.05) . Conclusion: LMR in patients with pneumoconiosis has a certain correlation with lung function and blood gas analysis, LMR is expected to become a sensitive indicator for evaluating pneumoconiosis.

[Inhibition of Sonic Hedgehog signaling inhibits fibrous scar formation and adversely affects functional outcome after ischemic brain injury in rats]

OBJECTIVE

To investigate the effects of inhibiting Sonic Hedgehog (Shh) signaling on fibrous scar formation and functional outcome after ischemic brain injury.

METHODS

Adult SD rats were randomized into sham-operated group, middle cerebral artery occlusion (MCAO) and reperfusion (I/R) group, I/R with intraventricular empty adenoviral vector (rAd-NC) injection group, and I/R with adenovirus-mediated Shh knockdown (rAd-ShShh) group. After the treatments, the neurological deficits of the rats were assessed, and the protein and mRNA expressions of fibronectin (Fn), α-SMA, and Shh in the ischemic hemisphere were detected with immunofluorescence assay and qPCR; TUNEL staining was used for detecting neural cell apoptosis. In the cell experiment, primary meningeal fibroblasts isolated from neonatal SD rats were pretreated for 24 h with TGF-β1 or TGF-β1 plus cyclopamine (CYC) before oxygen-glucose deprivation for 150 min followed by reoxygenation for 72 h (OGD/R). CCK-8 assay and scratch test were performed to examine the changes in cell proliferation and migration, and immunofluorescence assay, qPCR and Western blotting were used for detecting cell transformation and the expressions of Shh, α-SMA, and Fn.

RESULTS

Cerebral I/R injury significantly increased the protein and mRNA expressions of Shh, α-SMA, and Fn in the ischemic hemisphere of the rats, but their expression levels were significantly lowered by intraventricular injection of rAd-Shshh (P < 0.05), which obviously increased cell apoptosis in the ischemic hemisphere (P < 0.05) and improved modified mNSS and modified Bederson scores of the rats (P < 0.05). In the cell experiment, pretreatment with TGF-β1 and TGF-β1+CYC both increased the viability of the primary meningeal fibroblasts after OGD/R. TGF-β1 significantly enhanced the migration ability and induced obvious transformation of the exposed cells (P < 0.05), but these effects were significantly attenuated by co-treatment with CYC (P < 0.05). The expressions of Shh, α-SMA and Fn in the TGF-β1 group were all significantly higher in TGF-β1-treated cells (P < 0.05) and were obviously lowered by co-treatment with CYC (P < 0.05).

CONCLUSION

Inhibition of Shh signaling may inhibit fibrous scar formation and functional recovery in rats after ischemic brain injury.

Epithelial HIF2α expression induces intestinal barrier dysfunction and exacerbation of arthritis

OBJECTIVE

To investigate how the mucosal barrier in the intestine influences the development of arthritis, considering that metabolic changes in the intestinal epithelium influence its barrier function.

METHODS

Intestinal hypoxia inducible factor (HIF)-2α expression was assessed before, at onset and during experimental arthritis and human rheumatoid arthritis (RA). Intestinal epithelial cell-specific HIF2α conditional knock-out mice were generated (HIF2α∆IEC) and subjected to collagen-induced arthritis. Clinical and histological courses of arthritis were recorded; T-cell and B-cell subsets were analysed in the gut and secondary lymphatic organs; and intestinal epithelial cells were subjected to molecular mRNA sequencing in HIF2α∆IEC and littermate control mice. The gut intestinal HIF2α target genes were delineated by chromatin immunoprecipitation and luciferase experiments. Furthermore, pharmacological HIF2α inhibitor PT2977 was used for inhibition of arthritis.

RESULTS

Intestinal HIF2α expression peaked at onset of experimental arthritis and RA. Conditionally, deletion of HIF2α in gut epithelial cells inhibited arthritis and was associated with improved intestinal barrier function and less intestinal and lymphatic Th1 and Th17 activation. Mechanistically, HIF2α induced the transcription of the pore-forming claudin (CLDN)-15, which inhibits intestinal barrier integrity. Furthermore, treatment with HIF2α inhibitor decreased claudin-15 expression in epithelial cells and inhibited arthritis.

CONCLUSION

These findings show that the HIF2α-CLDN15 axis is critical for the breakdown of intestinal barrier function at onset of arthritis, highlighting the functional link between intestinal homeostasis and arthritis.

POS0409 INTESTINAL HIF1α EXPRESSION PROTECTS AGAINST EPITHELIAL CELL DEATH IN ARTHRITIS

Background

While a so-called gut-joint axis is supported by many clinical observations, the current knowledge on such axis is mostly confined to descriptive and correlative data, e.g. showing the microbiota changes are associated with arthritis. In contrast, mechanistic data on how molecular changes in the intestinal epithelium influence the development of arthritis are scarce.

Objectives

To investigate, whether the mucosal barrier in the intestine dependent of the epithelial cell survival maintenance, influences the development of arthritis.

Methods

Intestinal hypoxia inducible factor (HIF)-1α expression was assessed before, at onset and during experimental arthritis and human rheumatoid arthritis (RA). Intestinal epithelial cell-specific HIF1α conditional knock-out mice were generated (HIF1αΔIEC) and subjected to collagen-induced arthritis (CIA). Clinical and histological courses of arthritis were recorded, and T and B cell subsets were analyzed in the gut and secondary lymphatic organs, and intestinal epithelial cells were subjected to molecular mRNA sequencing in HIF1αΔIEC and littermate control mice. Furthermore, pharmacologic HIF1α stabilization by PHD inhibitor was used for the treatment of arthritis.

Results

Intestinal HIF1α expression peaked at onset and remained high in experimental arthritis and RA. Conditionally deletion of HIF1α in gut epithelial cells strongly exacerbate arthritis and was associated with increased gut epithelial cell death, intestinal and lymphatic Th1 and Th17 activation. Mechanistically, HIF1α inhibits the transcription of necroptotic and apoptotic markers, which leads to a defect in the intestinal barrier integrity. Furthermore, treatment with HIF1α stabilization reinforced the gut epithelial cell survival and inhibited arthritis.

Conclusion

These findings show that the HIF1α regulating epithelial cells survival is critical for the breakdown of the intestinal barrier function in arthritis highlighting the functional link between intestinal homeostasis and arthritis.

Disclosure of Interests

None declared.

Combination therapy with interleukin-15 and metformin as a synergistic treatment for pancreatic cancer

OBJECTIVE

To investigate the efficacies and mechanisms of combination therapy with interleukin-15 (IL-15) and metformin (Met) on suppressing pancreatic cell proliferation and protecting Panc02-bearing mice.

MATERIALS AND METHODS

MTT assays were applied to assess the inhibitory effects of IL-15 combined Met or Met and IL-15 alone on proliferation of normal HPDE6-C7 and Panc02 cells. After tumor grew up to 150 mm3, the Panc02-bearing xenograft model mice were randomly divided into saline group, IL-15 and Met alone group and combined treatment group (n=8) with the administration of each agent every other day for three weeks, and survival rates were recorded. The changes in tumor size, expression levels of the apoptosis, autophagy as well as Akt/mTOR/STAT3-related factors in tumor tissues were all measured.

RESULTS

MTT assays demonstrated significantly inhibiting efficacy of combination therapy with IL-15 and Met on Panc02 cell proliferation compared to other groups (all p<0.05) with combination index<1 showing evident synergistic effect. Moreover, the apoptosis rate of Panc02 cell under combined treatment were 95.5±3.2% and significantly higher than those of others (all p<0.01). In addition, combined administration remarkably inhibited the growth of pancreatic carcinoma, and improved survival rate of Panc02-bearing model with less body weight loss. Furthermore, combined treatment significantly downregulated anti-apoptotic proteins as well as Akt/mTOR/STAT3 signaling pathway and upregulated autophagy related factors, respectively, compared with those of monotherapy groups in both Panc02 cells and tumor tissues.

CONCLUSIONS

Combined treatment of IL-15 with Met showed synergistic anti-tumor efficacies on Panc02 cells attributing to promotion on apoptosis, autophagy and inhibition on Akt/mTOR/STAT3 signaling-transduction in Panc02-bearing model mice.

Development of solid state terahertz interferometer for the first plasma on HL-2M tokamak

A solid state terahertz interferometer has been developed on the recent commissioned HL-2M tokamak. It can work in a wide frequency region of 220-325 GHz, and the terahertz wave is generated from a low frequency phase locked voltage controlled oscillator with the frequency multiplying technique. A phase processor based on field programmable gate array (FPGA) technology is designed for the heterodyne interferometer, and it contributes to real-time display of electron density. To extract phase information, a novel numerical algorithm related to fast Fourier transform is written on the FPGA chip and enables one to obtain phase shift without being affected by amplitude variation induced by plasma absorption or frequency modulation from the outer electromagnetic environment. The interferometer achieves minimum measurable electron density in the order of 10¹⁶ m^-3. With the plasma diagnosis, electron density and low frequency tearing mode have been measured during the first experimental campaign.

A remote gain controlled and polarization angle tunable Doppler backward scattering reflectometer

Remote control of the diagnostic systems is the basic requirement for the high performance plasma operation in a fusion device. This work presents the development of the remote control system for the multichannel Doppler backward scattering (DBS) reflectometers. It includes a remote controlled quasi-optical system and a remote intermediate frequency (IF) amplifier gain control system. The quasi-optical system contains a rotational polarizer, its polarization angle is tunable through a remote controlled motor, and it could combine the microwave beams with a wide frequency range into one focused beam. The remote IF gain control system utilizes the digital microcontroller (MCU) technique to regulate the signal amplitude for each signal channel. The gain parameters of amplifiers are adjustable, and the feedback of working status in the IF system will be sent to MCU in real time for safe operation. The gain parameters could be controlled either by the Ethernet remote way or directly through the local control interface on the system. Preliminary experimental results show the effectiveness of the remote controlled multichannel DBS system.

[The value of MRI plain scan and DWI in the diagnosis of brain metastases]

Objective: To investigate the clinical value of magnetic resonance imaging (MRI) plain scan and diffusion weighted imaging (DWI) in the diagnosis of brain metastases. Methods: The MRI plain imaging findings of 105 cases with brain metastases and 103 cases without brain metastases confirmed by enhanced MRI examination and clinical diagnosis were retrospectively analyzed. The comparisons of plain MRI findings including T1 weighted image (T1WI), T2WI, T2/fluid attenuated inversion recovery (T2/FLAIR), DWI and apparent diffusion coefficient (ADC) values were made between brain metastases and non-brain metastases. Results: The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T1WI in the brain metastatic group were 54, 23, 9 and 19, respectively, while the numbers of hypo-intensity and iso-intensity in the non-brain metastatic group were 52 and 51, respectively, with statistically significant difference (P<0.001). The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T2WI in the brain metastatic group were 1, 9, 72 and 23, respectively, while the numbers of iso-intensity and hyper-intensity in the non-brain metastatic group were 11 and 92, respectively, with statistically significant difference (P<0.001). The numbers of hypo-intensity, hyper-intensity and heterogeneous signal intensity of DWI in the brain metastatic group were 4, 31 and 65, respectively, while the number of hyper-intensity in the non-brain metastatic group was 4 and others were iso-intensity, respectively, with statistically significant difference (P<0.001). The numbers of hypo-intensity, iso-intensity, hyper-intensity and heterogeneous signal intensity of T2WI/FLAIR in the brain metastatic group were 4, 5, 60 and 36, respectively, while all cases in the non-brain metastatic group were hyper-intensity, with statistically significant difference (P<0.001). The number of lesion accompanied with peripheral edema in the brain metastatic group were 69 cases, significantly higher than 0 cases in the non-brain metastatic group (P<0.001). The mean ADC value in the brain metastatic group were (0.919±0.019)×10(-3) mm(2)/s, significantly lower than (1.098±0.012)×10(-3) mm(2)/s of non-brain metastatic group (P<0.05). Conclusions: For patients with a history of primary malignancy, the MRI plain scan signals of T1WI, T2WI, T2WI/FLAIR and DWI are significantly different between brain metastatic tumor and non-metastatic tumor. The mixed signal, peripheral edema and the restriction of DWI diffusion indicate brain metastases. The combined application of the above parameters can improve the diagnostic efficacy of predicting brain metastases, and contrast enhancement MRI examination should be performed for the confirmation of diagnosis.

Partial repigmentation of a vitiliginous nipple areolar complex following therapeutic mammoplasty

We discuss the unusual repigmentation of a vitiliginous region of a nipple areolar complex following a therapeutic mammoplasty. We consider the autoimmune mechanisms behind the pathogenesis of vitiligo and their potential interplay with the immunological pathways involved in this patient's breast cancer and ultimately in the postoperative recovery period. This case highlights the potential interconnecting thread of immunological disruptions, which may provide a springboard for further discussion around the treatment for vitiligo. It also provides a useful point of note when counselling darker skin patients around scarring when undergoing surgical interventions.

Genomic scan revealed KIT gene underlying white/gray plumage color in Chinese domestic geese

Goose is an important type of domesticated poultry. The wild geese that are regarded as the ancestors of modern domestic geese present gray plumage. Domesticated, geese have both white and gray feathers. To elucidate the genetic mechanisms underlying the formation of white and gray plumage in geese, we resequenced the whole genome of 18 geese from six populations including white and gray goose breeds. The average sequencing depth per individual was 9.81× and the average genome coverage was 96.8%. A total of 346 genes were detected in the top 1% of F_ST scores of gray- and white-feathered geese, and a significant F_ST site was located in the intron region within the KIT gene, the 18 bp deletion in KIT having the strongest potential association with white feathers. It has been reported that a number of genes are associated with plumage colors in birds. However, no studies have identified the relationship between KIT and plumage color in birds at present, although the white coat can be attributed to mutations in KIT in some mammals. Our study showed that that KIT is a plausible candidate gene for white/gray plumage color in Chinese domestic geese.

MicroRNA-26b-5p alleviates cerebral ischemia-reperfusion injury in rats via inhibiting the N-myc/PTEN axis by downregulating KLF10 expression

MicroRNAs plays important role in cerebral ischemia-reperfusion (CIR). However, the role of miR-26b-5p in CIR injury remains unclear. PC12 cells were treated with oxygen-glucose deprivation (OGD) for 0 h, 2 h, 4 h, 6 h, and then reoxygenated for 24 h to construct an in vitro I/R model. Then, miR-26b-5p mimic, small interfering RNA of KLF10 and KLF10 overexpression plasmid were transfected into cells respectively for mechanism study. Our results showed that miR-26b-5p was downregulated in OGD/R-induced PC12 cells. After overexpression of miR-26b-5p, cell proliferation ability was enhanced, apoptosis, ROS and inflammatory mediators were inhibited. Bioinformatics analysis indicated that miR-26b-5p was directly bound to the 3' UTR of KLF10, and downregulated the expression of KLF10. KLF10 was upregulated in OGD/R cells, and transfection with si-KLF10 promoted cell proliferation and reduced apoptosis, NO concentration and inflammatory factor secretion. Moreover, pcDNA-KLF10 reversed the inhibitory effects of miR-26b-5p mimic on apoptosis, NO content and inflammatory factor secretion, as well as the downregulation of N-myc and PTEN expression. Meanwhile, I/R rat models were constructed and divided into sham operation group (femoral artery isolation only), model group (middle cerebral artery occlusion model of rats was prepared by thread embolization), treatment group (200 µL of miR-26b-5p mimic was injected into the brain of model rats). We observed that the infarct size of brain tissue was reduced, KLF10 expression was downregulated, and apoptosis and inflammatory response were reduced. These results suggest that miR-26b-5p had protective effects on CIRI and it may be a potential treatment target.

[Application value of high-throughput gene copy number variation detection in the diagnosis of enlarged vestibular aqueduct]

Objective: To explore the application value of high-throughput gene detection method of copy number variations (CNV) in the diagnosis of enlarged vestibular aqueduct (EVA). Methods: A total of 46 nonsyndromic hearing loss patients with EVA were recruited between May 2014 and December 2016 from Department of Otolaryngology of Xiangya Hospital, Central South University. A high-throughput multiplex analysis method based on double ligation and multiple fluorescent PCR was designed and performed to detect CNV in the three EVA-related genes (SLC26A4, FOXI1 and KCNJ10). The data were analyzed by GeneMapper v4.1. Healthy volunteers (n=100) were selected as normal controls. Results: A total of 46 EVA patients were detected (32 males, 14 females, aged 1 to 26 years). In 4 EVA patients, deletions of exons 1-3 of SLC26A4 gene (4/46, 8.7%) were detected, which were not reported in the database of genomic variants (DGV), and were absent in 100 normal controls. There was no CNV detected in FOXI1 and KCNJ10 in the study. Conclusions: In the current study, three known EVA-related genes were designed as the target area for CNV detection by high-throughput ligation-dependent probe amplification (HLPA) analysis. This method can be used as a supplementary analysis of point mutation detection of hearing loss, which helps achieve the accurate genetic diagnosis of EVA.

Intratumor Heterogeneity Correlates With Reduced Immune Activity and Worse Survival in Melanoma Patients

Background

Human malignant melanoma is a highly aggressive, heterogeneous and drug-resistant cancer. Due to a high number of clones, harboring various mutations that affect key pathways, there is an exceptional level of phenotypic variation and intratumor heterogeneity (ITH) in melanoma. This poses a significant challenge to personalized cancer medicine. Hitherto, it remains unclear to what extent the heterogeneity of melanoma affects the immune microenvironment. Herein, we explore the interaction between the tumor heterogeneity and the host immune response in a melanoma cohort utilizing The Cancer Genome Atlas (TCGA).

Methods

Clonal Heterogeneity Analysis Tool (CHAT) was used to estimate intratumor heterogeneity, and immune cell composition was estimated using CIBERSORT. The Overall Survival (OS) among groups was analyzed using Kaplan-Meier curves with the log-rank test and multivariate cox regression. RNA-seq data were evaluated to identify differentially expressed immunomodulatory genes. The reverse phase protein array (RPPA) data platform was used to validate immune responses at protein level.

Results

Tumors with high heterogeneity were associated with decreased overall survival (p = 0.027). High CHAT tumors were correlated with less infiltration by anti-tumor CD8 T cells (p = 0.0049), T follicular cells (p = 0.00091), and M1 macrophages (p = 0.0028), whereas tumor-promoting M2 macrophages were increased (p = 0.02). High CHAT tumors correlated with a reduced expression of immunomodulatory genes, particularly Programmed Cell Death 1 (PD1) and its ligand PD-L1. In addition, high CHAT tumors exhibited lower immune Cytotoxic T lymphocytes (CTLs)-mediated toxicity pathway score (p = 2.9E-07) and cytotoxic pathway score (p = 2.9E-08). High CHAT tumors were also associated with a lower protein level of immune-regulatory kinases, such as lymphocyte-specific protein tyrosine kinase (LCK) (p = 3.4e-5) and spleen tyrosine kinase (SYK) (p = 0.0011).

Conclusions

Highly heterogeneous melanoma tumors are associated with reduced immune cell infiltration and immune response activation as well as decreased survival. Our results reveal that intratumor heterogeneity is an indicative factor for patient survival due to its impact on anti-tumor immune response.

[Establishment of nutrition literacy core items for Chinese preschool children]

Objective: To establish the nutrition literacy core items for preschool children in China. Methods: The framework system and preliminary items of nutrition literacy were established through literature review and experts consultation. E-Delphi method was used to determine the nutrition literacy items. Nine experts in the field of nutrition, child and adolescent health, health education were invited to score the importance of each nutrition literacy item via Email. The judgment basis and familiarity of experts towards the items, active coefficient, authority coefficient and harmony coefficient were evaluated and analyzed to generate the final list of nutrition literacy items. Results: In the first round of E-Delphi consultation, the active coefficient and authority coefficient were 88.9%(8/9) and(0.88±0.07).The harmony coefficient was 0.350 (χ²=36.432, P=0.001). In the second round, the active coefficient and authority coefficient were 100% (9/9) and (0.89±0.11).The harmony coefficient was 0.347 (χ²=34.330, P<0.001). After qualitative and quantitative analyses, we identified the final list of nutrition literacy items consisting of two scales (basic knowledge, lifestyles and dietary behaviors), six subscales (food knowledge, food characteristic, food choice, dietary behavior, dietary safety, and physical activity)with 14 items in total. Conclusion: The framework system and core items of nutrition literacy are established for Chinese preschool children, which could provide a reference basis for the implementation of nutrition education project and the establishment of standardized evaluation tools.

Multiyear in-situ L-band microwave radiometry of land surface processes on the Tibetan Plateau

We report a unique multiyear L-band microwave radiometry dataset collected at the Maqu site on the eastern Tibetan Plateau and demonstrate its utilities in advancing our understandings of microwave observations of land surface processes. The presented dataset contains measurements of L-band brightness temperature by an ELBARA-III microwave radiometer in horizontal and vertical polarization, profile soil moisture and soil temperature, turbulent heat fluxes, and meteorological data from the beginning of 2016 till August 2019, while the experiment is still continuing. Auxiliary vegetation and soil texture information collected in dedicated campaigns are also reported. This dataset can be used to validate the Soil Moisture and Ocean Salinity (SMOS) and Soil Moisture Active Passive (SMAP) satellite based observations and retrievals, verify radiative transfer model assumptions and validate land surface model and reanalysis outputs, retrieve soil properties, as well as to quantify land-atmosphere exchanges of energy, water and carbon and help to reduce discrepancies and uncertainties in current Earth System Models (ESM) parameterizations. Measurement cases in winter, pre-monsoon, monsoon and post-monsoon periods are presented.

Computational modelling for the spiral flow in umbilical arteries with different systole/diastole flow velocity ratios

The systole/diastole (S/D) flow velocity ratios in umbilical arteries (UAs) have been used to assess the health status of the feto-placental circulation, yet its connection to the morphology of UAs, specifically its coiling pattern remains unclear. Spiral flow induces unbalanced wall shear stress (WSS) distribution in UAs, and may contribute to the uneven arterial wall thickness, and the chirality. In this paper, we use a 3D computational fluid dynamics (CFD) technique to quantify the wall shear stress (WSS) in UA models of two configurations, i.e. at 0.17 and 0.50 spirals per centimeter, to represent normo- and hyper-coiling, respectively. For CFD simulations we use two different S/D ratios (3.02 and 5.70) revealed from the ultrasonography waveforms of a normal and an intrauterine growth restriction (IUGR) case. We found that more coils in the UA model enhanced WSS throughout a cardiac cycle (up to 24%) with the same inflow condition. In addition, time-averaged WSS are generally increased and more uneven in the hyper-coiling model. We suggest that the large WSS difference between the peak systole and end diastole (62% higher in the IURG case than the normal case) may induce uneven stenosis distribution at UAs, and contribute to UA chirality.

LepR-Expressing Stem Cells Are Essential for Alveolar Bone Regeneration

Stem cells play a critical role in bone regeneration. Multiple populations of skeletal stem cells have been identified in long bone, while their identity and functions in alveolar bone remain unclear. Here, we identified a quiescent leptin receptor–expressing (LepR+) cell population that contributed to intramembranous bone formation. Interestingly, these LepR+ cells became activated in response to tooth extraction and generated the majority of the newly formed bone in extraction sockets. In addition, genetic ablation of LepR+ cells attenuated extraction socket healing. The parabiosis experiments revealed that the LepR+ cells in the healing sockets were derived from resident tissue rather than peripheral blood circulation. Further studies on the mechanism suggested that these LepR+ cells were responsive to parathyroid hormone/parathyroid hormone 1 receptor (PTH/PTH1R) signaling. Collectively, we demonstrate that LepR+ cells, a postnatal skeletal stem cell population, are essential for alveolar bone regeneration of extraction sockets.