A Combined Treatment of BMP2 and Soluble VEGFR1 for the Enhancement of Tendon-Bone Healing by Regulating Injury-Activated Skeletal Stem Cell Lineage

BACKGROUND

Bone morphogenetic protein 2 (BMP2) is an appealing osteogenic and chondrogenic growth factor for promoting tendon-bone healing. Recently, it has been reported that soluble vascular endothelial growth factor (VEGF) receptor 1 (sVEGFR1) (a VEGF receptor antagonist) could enhance BMP2-induced bone repair and cartilage regeneration; thus, their combined application may represent a promising treatment to improve tendon-bone healing. Moreover, BMP2 could stimulate skeletal stem cell (SSC) expansion and formation, which is responsible for wounded tendon-bone interface repair. However, whether the codelivery of BMP2 and sVEGFR1 increases tendon enthesis injury-activated SSCs better than does BMP2 alone needs further research.

PURPOSE

To study the effect of BMP2 combined with sVEGFR1 on tendon-bone healing and injury-activated SSC lineage.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 128 C57BL/6 mice that underwent unilateral supraspinatus tendon detachment and repair were randomly assigned to 4 groups: (1) untreated control group; (2) hydrogel group, which received a local injection of the blank hydrogel at the injured site; (3) BMP2 group, which received an injection of hydrogel with BMP2; and (4) BMP2 with sVEGFR1 group, which received an injection of hydrogel with BMP2 and sVEGFR1. Histology, micro-computed tomography, and biomechanical tests were conducted to evaluate tendon-bone healing at 4 and 8 weeks after surgery. In addition, flow cytometry was performed to detect the proportion of SSCs and their downstream differentiated subtypes, including bone, cartilage, and stromal progenitors; osteoprogenitors; and pro-chondrogenic progenitors within supraspinatus tendon enthesis at 1 week postoperatively.

RESULTS

The repaired interface in BMP2 with sVEGFR1 group showed a significantly improved collagen fiber continuity, increased fibrocartilage, greater newly formed bone, and elevated mechanical properties compared with the other 3 groups. There were more SSCs; bone, cartilage, and stromal progenitors; osteoprogenitors; and pro-chondrogenic progenitors in the BMP2 with sVEGFR1 group than that in the other groups.

CONCLUSION

Our study suggests that the combined delivery of BMP2 and sVEGFR1 could promote tendon-bone healing and stimulate the expansion of SSCs and their downstream progeny within the injured tendon-bone interface.

CLINICAL RELEVANCE

Combining BMP2 with sVEGFR1 may be a good clinical treatment for wounded tendon enthesis healing.

[Expressions of NLRP3, Caspase-1, and GSDMD in nasopharyngeal carcinoma tissue and association with recurrence and metastasis]

Objective: To investigate the expressions of Nod-like receptor protein 3 (NLRP3), cysteine-aspartic acid protease 1 (Caspase-1), and Gasdermin D (GSDMD) in nasopharyngeal carcinoma (NPC), and their relationships with the recurrence and metastasis of NPC. Methods: A retrospective study was conducted on 421 patients diagnosed with NPC between December 2014 and January 2020. The expressions of NLRP3, Caspase-1, and GSDMD in pathological specimens were examined with immunohistochemistry and multiplex immunofluorescence staining. Univariate and multivariate Cox regression analyses were applied to identify the factors influencing NPC recurrence and metastasis. In vitro experiments with NPC cell line HNE-2 were used to explore the functional mechanisms of NLRP3, Caspase-1, and GSDMD. Results: Multivariate Cox analysis revealed that tumor staging of Ⅲ-Ⅳ(HRrecurrence=2.74, 95%CIrecurrence: 1.61-4.65; HRmetastasis=1.90, 95%CImetastasis: 1.04-3.49) and pre-treatment plasma EBV-DNA levels≥1 500 copies/ml (HRrecurrence=1.91, 95%CIrecurrence: 1.13-3.23; HRmetastasis=2.07, 95%CImetastasis: 1.23-3.50)were independent risk factors for NPC recurrence and metastasis, while positive expression of NLRP3(HRrecurrence=0.17, 95%CIrecurrence: 0.08-0.35; HRmetastasis=0.30, 95%CImetastasis: 0.15-0.59), Caspase-1(HRrecurrence=0.32, 95%CIrecurrence: 0.18-0.59; HRmetastasis=0.43, 95%CImetastasis: 0.25-0.76), and GSDMD(HRrecurrence=0.48, 95%CIrecurrence: 0.25-0.91; HRmetastasis=0.96, 95%CImetastasis: 0.53-1.74) served as independent protective factors. Age (HR=1.02, 95%CI: 1.01-1.04) and intensity-modulated radiotherapy (HR=0.51, 95%CI: 0.30-0.88) were independent factors for NPC recurrence, whereas chemotherapy (HR=0.50, 95%CI: 0.29-0.88) acted as an independent protective factor for NPC metastasis (all P<0.05). NPC patients with positive expressions of the three proteins had higher locoregional recurrence-free survival, distant metastasis-free survival, and overall survival compared to those with negative expressions (all P<0.05). In vitro experiments revealed that the overexpression of NLRP3 activated the NLRP3/Caspase-1/GSDMD signaling pathway, as evidenced by Western Blot analysis. Enzyme-linked immunosorbent assay and scanning electron microscopy demonstrated that overexpression of NLRP3 promoted pyroptosis in HNE-2 cells. Cellular functional assays further confirmed that overexpression of NLRP3 significantly inhibited the proliferation, invasion, and migration of HNE-2 cells. Conclusion: Positive expressions of NLRP3, Caspase-1, and GSDMD serves as independent protective factors for recurrence and metastasis of NPC, potentially by promoting cell pyroptosis and thus inhibiting NPC cell proliferation, invasion, and migration.

Psychological effects of COVID-19 outbreak on mental health in parents of children with hematopathy

OBJECTIVE

We explored whether parents of children with hematopathy had more psychosocial problems than parents of healthy children during the COVID-19 outbreak.

SUBJECTS AND METHODS

An online survey was performed, and a total of 1,116 parents participated. The mental health variables were assessed via the Simplified Coping Style Questionnaire (SCSQ) and the Symptom Checklist-Revised (SCL-90-R).

RESULTS

Compared with parents of healthy children, parents of children with hematopathy have a higher possibility of negative coping style (70.9% vs. 33.2%, p=0.01) and are more concerned with media reports related to the pandemic (37.8% vs. 17.6%, p=0.02). In SCL-90-R somatization, obsessive-compulsive, and anxiety scale, the parents of children with hematopathy have higher scores than parents of healthy children (12.50±1.69 vs. 12.23±1.37, p<0.01; 13.42±6.69 vs. 10.47±2.25, p<0.01; 15.21±5.53 vs. 10.52±2.34, p<0.01, respectively). History of visiting Wuhan, and history of epidemics occurring in the community are independent risk factors of parental obsessive-compulsive and anxiety symptoms (p<0.01).

CONCLUSIONS

Parents of children with hematopathy had evident severe symptoms of obsessive-compulsive and anxiety during the outbreak of COVID-19. Providing psychological interventions and beneficial approaches to parents of children with hematopathy urgently needs to be realized.

Erratum: Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande [Phys. Rev. Lett. 130, 031802 (2023)]

This corrects the article DOI: 10.1103/PhysRevLett.130.031802.

Single-cell RNA sequencing reveals cellular and molecular heterogeneity in fibrocartilaginous enthesis formation

The attachment site of the rotator cuff (RC) is a classic fibrocartilaginous enthesis, which is the junction between bone and tendon with typical characteristics of a fibrocartilage transition zone. Enthesis development has historically been studied with lineage tracing of individual genes selected a priori, which does not allow for the determination of single-cell landscapes yielding mature cell types and tissues. Here, in together with open-source GSE182997 datasets (three samples) provided by Fang et al., we applied Single-cell RNA sequencing (scRNA-seq) to delineate the comprehensive postnatal RC enthesis growth and the temporal atlas from as early as postnatal day 1 up to postnatal week 8. And, we furtherly performed single-cell spatial transcriptomic sequencing on postnatal day 1 mouse enthesis, in order to deconvolute bone-tendon junction (BTJ) chondrocytes onto spatial spots. In summary, we deciphered the cellular heterogeneity and the molecular dynamics during fibrocartilage differentiation. Combined with current spatial transcriptomic data, our results provide a transcriptional resource that will support future investigations of enthesis development at the mechanistic level and may shed light on the strategies for enhanced RC healing outcomes.

Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7 ( 16.3 ) × 10 20 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7 × 10 20 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin 2 θ 13 and the impact of priors on the δ CP measurement. Both analyses prefer the normal mass ordering and upper octant of sin 2 θ 23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin 2 θ 13 from reactors, sin 2 θ 23 = 0 . 561 - 0.032 + 0.021 using Feldman-Cousins corrected intervals, and Δ m 32 2 = 2 . 494 - 0.058 + 0.041 × 10 - 3 eV 2 using constant Δ χ 2 intervals. The CP-violating phase is constrained to δ CP = - 1 . 97 - 0.70 + 0.97 using Feldman-Cousins corrected intervals, and δ CP = 0 , π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2 σ credible level using a flat prior in δ CP , and just below 2 σ using a flat prior in sin δ CP . When the external constraint on sin 2 θ 13 is removed, sin 2 θ 13 = 28 . 0 - 6.5 + 2.8 × 10 - 3 , in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

Acupuncture and Chinese herbal medicine for menopausal mood disorder: a randomized controlled trial

OBJECTIVE

This study aimed to analyze the effectiveness of acupuncture combined with Chinese herbal medicine (CHM) on mood disorder symptoms for menopausal women.

METHODS

A total of 95 qualified Chinese participants were randomly assigned to one of three groups: 31 in the acupuncture combined with CHM group (combined group), 32 in the acupuncture combined with CHM placebo group (acupuncture group) and 32 in the CHM combined with sham acupuncture group (CHM group). The patients were treated for 8 weeks and followed up for 4 weeks. The data were collected using the Greene Climacteric Scale (GCS), self-rating depression scale (SDS), self-rating anxiety scale (SAS) and safety index.

RESULTS

The three groups each showed significant decreases in the GCS, SDS and SAS after treatment (p < 0.05). Furthermore, the effect on the GCS total score and the anxiety domain lasted until the follow-up period in the combined group (p < 0.05). Within the three groups, there was no difference in GCS and SAS between the three groups after treatment (p > 0.05). However, the combined group showed significant improvement in the SDS, compared with both the acupuncture group and the CHM group at 8 weeks and 12 weeks (p < 0.05). No obvious abnormal cases were found in any of the safety indexes.

CONCLUSIONS

The results suggest that either acupuncture, or CHM or combined therapy offer safe improvement of mood disorder symptoms for menopausal women. However, the combination therapy was associated with more stable effects in the follow-up period and a superior effect on improving depression symptoms.

The effect of local sympatholysis on bone-tendon interface healing in a murine rotator cuff repair model

Background

Although neuroregulation plays an important role in tissue healing, the key neuroregulatory pathways and related neurotransmitters involved in bone-tendon interface (BTI) healing are still unknown. It is reported that sympathetic nerves can regulate cartilage and bone metabolism, which are the basic aspects of BTI repair after injury, through the release of norepinephrine (NE). Thus, the purpose of this study was to explore the effect of local sympatholysis (LS) on BTI healing in a murine rotator cuff repair model.

Methods

Specifically, C57BL/6 mice underwent unilateral supraspinatus tendon (SST) detachment and repair was established on a total of 174 mature C57BL/6 mice (12 weeks old): 54 mice were used to examine the sympathetic fibers and its neurotransmitter NE for the representation of sympathetic innervation of BTI, while the rest of them were randomly allocated into (LS) group and control group to verify the effect of sympathetic denervation during BTI healing. The LS group were intervened with fibrin sealant containing 10 ​ng/ml guanethidine, while the control group received fibrin sealant only. Mice were euthanized at postoperative 2, 4 and 8 weeks for immunofluorescent, qRT-PCR, ELISA, Micro-computed tomography (CT), histology and biomechanical evaluations.

Results

Immunofluorescence, qRT-PCR and ELISA evaluations indicated that there were the expression of tyrosine hydroxylase (TH), NE and β2-adrenergic receptor (β2-AR) at the BTI site. All the above showed a trend of increasing at the early postoperative stage and they started to decrease with the healing time after a significant peak. Meanwhile, local sympathetic denervation of BTI was achieved after the use of guanethidine as shown in the NE ELISA outcomes in two groups. QRT-PCR analysis revealed that the healing interface in the LS group expressed more transcription factors, such as Runx2, Bmp2, Sox9, and Aggrecan, than the control group. Further, radiographic data showed that the LS group significantly possessed higher bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), and lower trabecular spacing (Tb.Sp) than the control group. Also, histological test results showed that there was more fibrocartilage regenerated at the healing interface in the LS group compared with the control group. Mechanical testing results demonstrated that the failure load, ultimate strength and stiffness in the LS group were significantly higher at postoperative week 4 (P ​< ​0.05), but not at postoperative week 8 (P ​> ​0.05), compared to the control group.

Conclusion

The regulation of sympathetic innervation was involved in the healing process of injured BTI, and local sympathetic denervation by using guanethidine was beneficial for BTI healing outcomes.The translational potential of this article: This is the first study to evaluate the expression and specific role of sympathetic innervation during BTI healing. The findings of this study also imply that the antagonists of β2-AR could serve as a potential therapeutic strategy for BTI healing. Also, we firstly successfully constructed a local sympathetic denervation mouse model by using guanethidine loaded fibrin sealant, which provided a new effective methodology for future neuroskeletal biology study.

Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande

We report a search for cosmic-ray boosted dark matter with protons using the 0.37  megaton×years data collected at Super-Kamiokande experiment during the 1996-2018 period (SKI-IV phase). We searched for an excess of proton recoils above the atmospheric neutrino background from the vicinity of the Galactic Center. No such excess is observed, and limits are calculated for two reference models of dark matter with either a constant interaction cross section or through a scalar mediator. This is the first experimental search for boosted dark matter with hadrons using directional information. The results present the most stringent limits on cosmic-ray boosted dark matter and exclude the dark matter-nucleon elastic scattering cross section between 10^{-33}cm^{2} and 10^{-27}cm^{2} for dark matter mass from 1  MeV/c^{2} to 300  MeV/c^{2}.

[Research progress on the pathogenesis of diabetes-related dry eye]

In recent years, with the further understanding of medical circles on diabetic ocular complications, the ocular surface abnormalities of diabetes has drawn increasing concerns. Nearly 50% of diabetic patients suffer from dry eye symptoms. The main manifestations of diabetes related dry eye were abnormal lacrimal secretion, poor lacrimal stability, decreased corneal sensitivity, persistent corneal epithelial defect and even corneal ulcer, which were mainly related to the changes of structure and function of lacrimal gland, the decrease of goblet cells in conjunctiva, the abnormality of meibomian gland function and the degeneration of corneal nerve caused by diabetes. In this paper, we summarized and analyzed the recent research progress on the effect of diabetes on lacrimal film, corneal innervation and lacrimal gland innervation, and the correlation between oxidative stress, advanced glycation end products and diabetes-related dry eye, to explore the pathogenesis of diabetes-related dry eye and to provide reference for clinical diagnosis, treatment and research.

Role of low-intensity pulsed ultrasound in regulating macrophage polarization to accelerate tendon-bone interface repair

Low-intensity pulsed ultrasound (LIPUS) has been proven to accelerate the healing of the tendon-bone interface (TBI), and macrophages are considered to play an important regulatory role. This study was designed to explore the polarization of macrophages during treatment of TBI injury with LIPUS. In a rat model of rotator cuff tear, LIPUS or mock sonication (controls) was administered from 1 week postoperatively. The supraspinatus-supraspinatus tendon-humerus complexes were harvested for further evaluation at different time points for measures such as new bone formation, TBI maturity, ultimate failure load and stiffness, and types of macrophages. In vitro, bone marrow-derived macrophages were cultured, and polarization was identified after stimulation with or without LIPUS (the LIPUS or control groups, respectively). Two weeks posttreatment, the LIPUS group showed higher bone volume/total volume ratios and better TBI maturity scores. Six weeks posttreatment, the failure load of the LIPUS group was significantly higher than that of the control group. LIPUS also accelerated initial inflammatory macrophage accumulation and facilitated anti-inflammatory macrophage polarization (M2) in the late period. In the in vitro macrophage polarization model, the LIPUS group showed a higher proportion of M2 macrophages and mRNA expression of anti-inflammatory genes than the control group, while there was no significant difference in the proinflammatory macrophages between the two groups. Our observations revealed that macrophage polarization may be a potential mechanism of LIPUS treatment for TBI repair.

High-speed railway and the intercity transmission of epidemics: Evidence from COVID-19 in China

In the context of the COVID-19 outbreak in Wuhan, we investigate the effect of intercity high-speed railway (HSR) connections on intercity transmission of epidemics in the absence of government intervention. Intercity HSR connections increase the number of COVID-19 patients per 10,000 population by 0.029, accounting for 45% of the total infections. Our results remain intact in several robustness assessments. The total economic loss owing to HSR connections to Wuhan is estimated to be USD 0.62 billion. The internal mechanism demonstrates that intercity HSR connections increase intercity COVID-19 transmission by facilitating human mobility between cities. Based on intercity transportation connections, our findings can help the government predict the direction and scope of virus transmission and control the intercity transmission of epidemics.

Effects of antidepressant medicines on preventing relapse of unipolar depression: a pooled analysis of parametric survival curves

BACKGROUND

Major depressive disorder is characterized by a high risk of relapse. We aimed to compare the prophylactic effects of different antidepressant medicines (ADMs).

METHODS

PubMed, Cochrane Central Register of Controlled Trials, Embase and the Web of Science were searched on 4 July 2019. A pooled analysis of parametric survival curves was performed using a Bayesian framework. The main outcomes were hazard ratios (HRs), relapse-free survival and mean relapse-free months.

RESULTS

Forty randomized controlled trials were included. The 1-year relapse-free survival for ADM (76%) was significantly better than that for placebo (56%). Most of the relapse difference (86.5%) occurred in the first 6 months. Most HRs were not constant over time. Proof of benefit after 6 months of follow-up was not established partially because of small differences between the drug and placebo after 6 months. Almost all studies used an 'enriched' randomized discontinuation design, which may explain the high relapse rates in the first 6 months after randomization.

CONCLUSIONS

The superiority of ADM v. placebo was mainly attributed to the difference in relapse rates that occurred in the first 6 months. Our analysis provided evidence that the prophylactic efficacy was not constant over time. A beneficial effect was observed, but the prevention of new episodes after 6 months was questionable. These findings may have implications for clinical practice.

Association Between Serum Uric Acid Levels and Suicide Attempts in Adolescents and Young Adults with Major Depressive Disorder: A Retrospective Study

PURPOSE

Uric acid (UA) is thought to exert neuroprotective roles. The purpose of this study was to examine the association of serum UA with suicide attempts (SA) in adolescents and young adults with major depressive disorder (MDD).

PATIENTS AND METHODS

We retrospectively recruited 533 participants with MDD aged 13 to 25 years, of which 168 had a history of SA in the past three months and 365 did not have a history of SA. Serum UA levels were measured using the uricase-peroxidase coupling method. In addition to overall serum UA level comparison in MDD individuals with and without SA, a stratified analysis by biological sex was carried out.

RESULTS

Compared to MDD individuals without a history of SA, serum UA levels were significantly lower in MDD individuals with SA (P < 0.001). Female MDD, but not male MDD individuals, with SA exhibited lower levels of UA than those without SA (P < 0.01). Importantly, serum UA remained significantly associated with SA in MDD individuals (OR = 0.996, 95% CI: 0.993~0.999, P < 0.01) when controlling for possible confounding variables.

CONCLUSION

This research identifies a relationship between serum UA levels and SA in adolescents and young adults with MDD. UA may represent a biological risk marker for SA, in particular for female MDD individuals.

Deletion in KRT75L4 linked to frizzle feather in Xiushui Yellow Chickens

Bird feathers are the product of interactions between natural and artificial selection. Feather-related traits are important for chicken selection and breeding. Frizzle feather is characterized by the abnormally development of feathers in chickens. In the current study, frizzle feather characteristics were observed in a local breed called Xiushui Yellow Chicken in Jiangxi, China. To determine the molecular mechanisms that underlie frizzle feather in Xiushui Yellow Chicken, four populations of three breeds (Xiushui Yellow Chicken with frizzle feathers, Xiushui Yellow Chicken with normal feathers, Guangfeng White-Ear Yellow Chicken, and Ningdu Yellow Chicken) were selected for whole-genome resequencing. Using a comparative genome strategy and genome-wide association study, a missense mutation (g.5281494A>G) and a 15-bp deletion (g.5285437-5285451delGATGCCGGCAGGACG) in KRT75L4 were identified as candidate mutations associated with frizzle feather in Xiushui Yellow Chicken. Based on genotyping performed in a large Xiushui Yellow Chicken population, the g.5285437-5285451delGATGCCGGCAGGACG mutation in KRT75L4 was confirmed as the putative causative mutation of frizzle feather. These results deepen the understanding of the molecular mechanisms responsible for frizzle feather, as well as facilitating the molecular detection and selection of the feather phenotype in Xiushui Yellow Chickens.

Early treadmill running delays rotator cuff healing via Neuropeptide Y mediated inactivation of the Wnt/β-catenin signaling

Background

Defining the optimal rehabilitation programs for rotator cuff healing remains a challenge. Early treadmill running may have negative effects on tendon-bone interface (TBI) healing with increased expression of Neuropeptide Y (NPY). However, the underlying mechanism is still unknown.

Methods

The mice were randomly assigned to four groups: control group, treadmill group, treadmill ​+ ​BIBO3304 group and BIBO3304 group alone. Specifically, the control group was allowed free cage activity without any treatment after surgery. The treadmill group received early treadmill running initiated from postoperative day 2. The treadmill ​+ ​BIBO3304 group received treadmill running combined with intra-articular injection of BIBO3304 postoperatively. The BIBO3304 group only received type 1 NPY receptor (Y1 receptor, Y1R) antagonist BIBO3304 postoperatively. Healing outcomes of the rotator cuff were evaluated by histological analysis, synchrotron radiation micro-computed tomography (SR-μCT) scanning, and biomechanical testing at 4 and 8 weeks after surgery. The expression of NPY and its Y1 receptor during the treadmill running were tested by immunofluorescence. In addition, the related signaling pathway of Neuropeptide Y among all groups was detected by immunohistochemistry and western-blot.

Results

Immunofluorescence results show that early treadmill training could lead to a significant increase in the expression of NPY at the healing site, and Y1R was widely expressed in both normal or injured rotator cuff without statistical difference. At the same time, early treadmill running delayed the healing of rotator cuff, as indicated with unsatisfactory outcomes, including a significantly lower histological score, decreased bone formation and inferior biomechanical properties at postoperative week 4 and 8. Moreover, the use of BIBO3304 could partly alleviate the negative effects of early treadmill running on the healing of rotator cuff and promote the natural healing process of rotator cuff, as evidenced by significant differences observed between the treadmill and treadmill ​+ ​BIBO3304 groups, as well as observed between the control and BIBO3304 groups. On the other hand, the expressions of Wnt3a and β-catenin in the treadmill group were significantly lower compared with the other groups, while the expression in the BIBO3304 group was the highest, as evaluated by immunohistochemistry and western-blot.

Conclusions

Early treadmill running increased the expression of NPY at the RC healing site, which might burden the expression of Wnt3a/β-catenin and delay the healing process, inhibition of Y1 receptor with BIBO3304 could promote bone-tendon healing through the Wnt/β-catenin signaling.

The translational potential of this article: This is the first study to evaluate the specific role of the NPY-Y1R axis and its underlying mechanism by which early treadmill running delays bone-tendon healing. Further, our study may provide references of precise and individualized exercise-based rehabilitation strategies for TBI healing in clinic.

The translational potential of this article

This is the first study to evaluate the specific role of the NPY-Y1R axis and its underlying mechanism by which early treadmill running delays bone-tendon healing. Further, our study may provide references of precise and individualized exercise-based rehabilitation strategies for TBI healing in clinic.

A Mild CO2 Etching Method To Tailor the Pore Structure of Platinum-Free Oxygen Reduction Catalysts in Proton Exchange Membrane Fuel Cells

The structural tailoring of pores is essential to high-performance Fe/N/C electrocatalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells. Current strategies for pore structure engineering are usually accompanied with a drastic change of the intrinsic activity-related surface, which may mask the real effects of the porous structure on ORR activity. Herein, a mild carbon dioxide (CO₂) etching method was used to flexibly tailor the pore structure of Fe/N/C electrocatalysts without drastic changes in their surface structure and property. In this way, via employing the Fe/N/C electrocatalysts as a model, the intrinsic impact of the pore structure on ORR activity was revealed. In addition, the CO₂ etching method developed a high-quality electrocatalyst (sample Fe/N/C-5% CO₂) with polarization performance exceeding that of the commercial Pt/C catalyst in the fuel cell working voltage region (>0.65 V). This work will promote the ongoing intensive studies on the rational design of the pore structures in the Fe/N/C electrocatalysts.

[Clinical value of emergency endovascular embolization in the interventional treatment for oral hemorrhage caused by carcinoma]

To evaluate the clinical value of emergency endovascular embolization in the interventional treatment for oral hemorrhage caused by carcinoma, 32 patients with oral hemorrhage caused by carcinoma, who received emergency endovascular embolization due to unsatisfactory hemostatic effect of conventional conservative treatment in the First Affiliated Hospital of Zhengzhou University from January 2014 to December 2019, were included in this study and their clinical data, laboratory data and imaging information were retrospectively analyzed. There were 16 males and 16 females, aged (60.6±13.6) years (34-88 years). Technical successful rate of emergency endovascular embolization, immediate successful rate of controlling hemorrhage, blood pressure before and after operation, hemoglobin before and after operation, postoperative complications and recurrence rate of oral hemorrhage were statistically analyzed. Results showed that technical successful rate of operation and immediate successful rate of controlling oral hemorrhage are both 100% (32/32). Recurrent oral hemorrhage occurred in 4 patients (13%). The hemorrhagic shock symptoms of all patients were significantly improved after interventional therapy. After operation, local swelling happened in 34% (11/32) patients and intermittent local pain happened in 22% (7/32) within 24 hours; the swelling and the pain gradually disappeared from 2nd to 5th days. Mild complications of transient fever happened in 9% (3/32) patients and disappeared spontaneously in the short term. No serious complications such as blindness, cerebrovascular accident or central nervous system disturbance occurred in all patients after operations. During the whole follow-up period (1 to 12 months), a total of 8 patients died. The causes of death were progression and metastasis of carcinoma (n=4), heart failure (n=2), severe pneumonia (n=1) and respiratory failure caused by recurrent oral hemorrhage (n=1). Owing to the remarkable short-term curative effect, repeatable operation, low recurrence rate of oral hemorrhage and low incidence of complications, emergency endovascular embolization can be used in the clinical therapy and application of oral hemorrhage caused by carcinoma.

[Research Status of Postmortem MSCT Angiography in Forensic Science]

Abstract

Virtual autopsy is a new technique for investigating the morphological changes of cadaveric tissues and organs by medical imaging technology. It has been widely used in the identification of causes of death. Multislice spiral computed tomography （MSCT） has become a routine inspection method in some identification institutions, although it cannot completely replace traditional autopsy, it plays a key auxiliary or substitute role in the identification of certain abnormal causes of death. Plain MSCT scan cannot visualize cadaveric vessels, but can perform cadaveric angiography to determine vascular injury or disease. This technology has entered a rapid development period in recent years, and has made a considerable progress in contrast agent, perfusion methods and imaging methods. This article summarizes several common cadaveric MSCT angiography methods, such as systemic angiography, angiography through cardiopulmonary resuscitation, targeted angiography, and angiography by cardiac puncture, and analyzes and compares the application prospects.

[Comparison of Three CNN Models Applied in Bone Age Assessment of Pelvic Radiographs of Adolescents]

Abstract

Objective To compare the performance of three deep-learning models （VGG19, Inception-V3 and Inception-ResNet-V2） in automatic bone age assessment based on pelvic X-ray radiographs. Methods A total of 962 pelvic X ray radiographs taken from adolescents （481 males, 481 females） aged from 11.0 to 21.0 years in five provinces and cities of China were collected, preprocessed and used as objects of study. Eighty percent of these X ray radiographs were divided into training set and validation set with random sampling method and used for model fitting and hyper-parameters adjustment. Twenty percent were used as test sets, to evaluate the ability of model generalization. The performances of the three models were assessed by comparing the root mean square error （RMSE）, mean absolute error （MAE） and Bland-Altman plots between the model estimates and the chronological ages. Results The mean RMSE and MAE between bone age estimates of the VGG19 model and the chronological ages were 1.29 and 1.02 years, respectively. The mean RMSE and MAE between bone age estimates of the Inception-V3 model and the chronological ages were 1.17 and 0.82 years, respectively. The mean RMSE and MAE between bone age estimates of the Inception-ResNet-V2 model and the chronological ages were 1.11 and 0.84 years, respectively. The Bland-Altman plots showed that the mean value of differences between bone age estimates of Inception-ResNet-V2 model and the chronological ages was the lowest. Conclusion In the automatic bone age assessment of adolescent pelvis, the Inception-ResNet-V2 model performs the best while the Inception-V3 model achieves a similar accuracy as VGG19 model.

Transfemoral-venous transcatheter access to left ventricle through the created communication of inter-ventricular septum with the assistance of arterio-venous circuit

Background

During transcatheter aortic/mitral valve replacement (TA/MVR), current available routes are limited due to unfavorable entry-angle, vessel-anatomy or mini-thoracotomy. Through created communication of inter-ventricular septum (C-IVS), transfemoral venous transcatheter access to left ventricle becomes feasible with the assistance of arterio-venous circuit.

Purpose

The study was conducted to investigate the feasibility and safety of transfemoral-venous transcatheter access to left ventricle through the created C-IVS in a swine model.

Methods

Via femoral artery, transcatheter puncture of mid-IVS was performed with the custom-made nickel-titanium needle (0.038-inch, needle-tip bent 60 degrees automatically associated with increased hardness when temperature was above 30°C) and 6F-sheath in 20 healthy Chinese mini-swine. Then femoral arterio-venous circuit was established through created C-IVS with hydrophilic guidewire in all swine, and femoral veno-venous circuit was further created through C-IVS and atrial septum in 4 swine. After pre-dilation of C-IVS, a 20F-sheath was introduced into left ventricle transvenously over the guidewire. Furthermore, transfemoral-venous TAVR was attempted with this approach in one swine. C-IVS was evaluated postoperatively and was further confirmed pathologically 2 months later.

Results

All transcatheter puncture of IVS was performed successfully in left ventricle and the thickness of mid-IVS was 7.67±0.98 mm. During the puncture, ventricular fibrillation occurred in one swine (successfully defibrillation) and only isolated ventricular premature beats/non-sustained ventricular tachycardia were observed in other swine. In all swine, femoral arterio-venous/veno-venous circuit was established via C-IVS, and the 20F-sheath was introduced into left ventricle safely through femoral vein and C-IVS. With the aid of vessel circuit, the 20F-sheath was further advanced into aorta in 16 swine (the entry-angle was 145.3±12.2 degrees) and into left atrium in 4 swine. After the procedure, there was one swine with moderate tricuspid regurgitation and 5 swine with mild residual shunt (2.6±0.7 mm). In addition, epicardial coronary arteries were normal in all swine. Two months later, residual shunt was still detected in 3 swine and the communication was confirmed pathologically. In other swine, there was no defect of IVS and mild replacement-scar was identified along C-IVS. In the swine underwent transfemoral-venous TAVR, prosthetic valve was deployed successfully with good function.

Conclusions

With the aid of vessel circuit, transfemoral-venous transcatheter access to left ventricle is feasible and safe via C-IVS, and transfemoral-venous TAVR was achieved successfully using this novel approach with favorable entry-angle.

Figure 1

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): National Natural Science Foundation of China

Indirect evaluation of device-endothelialization with cardiac-CT after transcatheter closure of atrial septal defect: how long should antiplatelet therapy last postoperatively?

Background

After transcatheter closure of atrial septal defect (ASD), it is still unclear about the in-vivo process of device-endothelialization in humans, which determines the duration of antiplatelet therapy. Based on contrast-uptake within device, cardiac-CT might have the potential to assess device-endothelialization indirectly.

Purpose

The study was conducted to investigate the status of device-endothelialization with cardiac-CT after transcatheter closure of ASD.

Methods

After more than 6 months of transcatheter ASD closure, cardiac-CT was performed in 119 patients (48M/71F; age: 46.7±14.4 years). According to contrast-uptake within device, complete or incomplete device-endothelialization was determined. In the latter, it was further divided into partial-endothelialization (with filling-defect) and no-endothelialization (without filling-defect). Multivariate logistic regression was used to determine the risk factors of incomplete device-endothelialization. In addition, device-endothelialization was analyzed grossly and histopathologically in 7 patients.

Results

During the implantation-period of 2.57±2.59 years, incomplete device-endothelialization was identified in 43.7% of patients (partial-endothelialization in 36 patients and no-endothelialization in 16 patients). Complete device-endothelialization occurred in 14.3% of patients during 0.5–1 year and 73.8% after one year. After 6-month antiplatelet therapy, migraine restarted in 15 patients with incomplete device-endothelialization and 3 patients with complete device-endothelialization. After one-year antiplatelet therapy, migraine was still detected in 4 of 15 patients with incomplete device-endothelialization. There was a significant association between high in-vivo device-thickness and incomplete device-endothelialization (P&lt;0.001) after adjusted for confounding factors. Pathological findings from 7 patients corresponded well with cardiac-CT.

Conclusions

Cardiac-CT had the potential to evaluate the status of device-endothelialization after transcatheter closure of ASD and there was a good clinico-pathological correlation. Incomplete device-endothelialization was common postoperatively in humans and was associated with device-oversizing. Further research is required to determine the appropriate duration of antiplatelet therapy after device implantation.

Figure 1

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): National Natural Science Foundation of China

Ultrathin 2D Mesoporous TiO2 /rGO Heterostructure for High-Performance Lithium Storage

Lithium-ion batteries (LIBs) have been widely applied and studied as an effective energy supplement for a variety of electronic devices. Titanium dioxide (TiO₂ ), with a high theoretical capacity (335 mAh g^-1 ) and low volume expansion ratio upon lithiation, has been considered as one of the most promising anode materials for LIBs. However, the application of TiO₂ is hindered by its low electrical conductivity and slow ionic diffusion rate. Herein, a 2D ultrathin mesoporous TiO₂ /reduced graphene (rGO) heterostructure is fabricated via a layer-by-layer assembly process. The synergistic effect of ultrathin mesoporous TiO₂ and the rGO nanosheets significantly enhances the ionic diffusion and electron conductivity of the composite. The introduced 2D mesoporous heterostructure delivers a significantly improved capacity of 350 mAh g^-1 at a current density of 200 mA g^-1 and excellent cycling stability, with a capacity of 245 mAh g^-1 maintained over 1000 cycles at a high current density of 1 A g^-1 . The in situ transmission electron microscopy analysis indicates that the volume of the as-prepared 2D heterostructures changes slightly upon the insertion and extraction of Li⁺ , thus contributing to the enhanced long-cycle performance.

Expression of T follicular helper lymphocytes with different subsets and analysis of serum IL-6, IL-17, TGF-β and MMP-3 contents in patients with rheumatoid arthritis

OBJECTIVE

To investigate the expression levels of T follicular helper (Tfh) with different subsets in patients with rheumatoid arthritis (RA) and their serum interleukin-6 (IL-6), interleukin-17 (IL-17), transforming growth factor-β (TGF-β) and matrix metalloproteinase 3 (MMP-3) contents.

PATIENTS AND METHODS

The medical records of 45 RA patients in the Department of Rheumatology and Immunology in the First Affiliated Hospital of Chengdu Medical College from January 2016 to April 2018 were retrospectively analyzed. They were divided into the RA high activity group (24 cases, group A) (DAS28 score ≥ 5.0) and RA low activity group (21 cases, group B) (3.2 < DAS28 score < 5.0). At the same time, 20 healthy subjects were selected as a control group. Flow cytometry was used to detect the expression levels of Tfh1, Tfh2 and Tfh17, enzyme-linked immunosorbent assay to detect serum IL-6, IL-17, IL-21 and MMP-3 concentrations. The correlation of Tfh cells with IL-6, IL-17, IL-21 and MMP-3 was analyzed.

RESULTS

Those of peripheral blood mononuclear cell (PBMC) Tfh2 and Tfh17 cells were significantly higher in group A than those in group B (p < 0.05). Compared with the control group, the concentrations of serum IL-6, IL-17 and MMP-3 significantly increased (p < 0.001), but that of serum TGF-β markedly decreased in group A and group B (p < 0.01). The concentrations of serum IL-6, IL-17 and MMP-3 were remarkably higher in group A than those in group B (p < 0.001), but that of serum TGF-β was significantly lower in group A than that in group B (p < 0.001). The expression level of PBMC Tfh2 cells, PBMC Tfh17 cells was positively correlated with serum IL-6, IL-17 and MMP-3. The expression levels of Tfh2 and Tfh17 cells are positively correlated with serum IL-6, IL-17 and MMP-3 concentrations, negatively correlated with serum TGF-β concentration.

CONCLUSIONS

Tfh2 and Tfh17 are expected to be new targets for immunotherapy in RA patients.

Research Progress and Prospect of Machine Learning in Bone Age Assessment

Abstract

Bone age assessment has always been one of the key issues and difficulties in forensic science. With the gradual development of machine learning in many industries, it has been widely introduced to imageology, genomics, oncology, pathology, surgery and other medical research fields in recent years. The reason why the above research fields can be closely combined with machine learning, is because the research subjects of the above branches of medicine belong to the computer vision category. Machine learning provides unique advantages for computer vision research and has made breakthroughs in medical image recognition. Based on the advantages of machine learning in image recognition, it was combined with bone age assessment research, in order to construct a recognition model suitable for forensic skeletal images. This paper reviews the research progress in bone age assessment made by scholars at home and abroad using machine learning technology in recent years.

Tumor-on-a-chip for integrating a 3D tumor microenvironment: chemical and mechanical factors

Tumor progression, including metastasis, is significantly influenced by factors in the tumor microenvironment (TME) such as mechanical force, shear stress, chemotaxis, and hypoxia. At present, most cancer studies investigate tumor metastasis by conventional cell culture methods and animal models, which are limited in data interpretation. Although patient tissue analysis, such as human patient-derived xenografts (PDX), can provide important clinical relevant information, they may not be feasible for functional studies as they are costly and time-consuming. Thus, in vitro three-dimensional (3D) models are rapidly being developed that mimic TME and allow functional investigations of metastatic mechanisms and drug responses. One of those new 3D models is tumor-on-a-chip technology that provides a powerful in vitro platform for cancer research, with the ability to mimic the complex physiological architecture and precise spatiotemporal control. Tumor-on-a-chip technology can provide integrated features including 3D scaffolding, multicellular culture, and a vasculature system to simulate dynamic flow in vivo. Here, we review a select set of recent achievements in tumor-on-a-chip approaches and present potential directions for tumor-on-a-chip systems in the future for areas including mechanical and chemical mimetic systems. We also discuss challenges and perspectives in both biological factors and engineering methods for tumor-on-a-chip progress. These approaches will allow in the future for the tumor-on-a-chip systems to test therapeutic approaches for individuals through using their cancerous cells gathered through approaches like biopsies, which then will contribute toward personalized medicine treatments for improving their outcomes.

Research Progress on Postmortem Changes of Computed Tomography Imaging Characteristics on Corpses

Abstract

Postmortem changes on corpses appear immediately after death, and can transform the original structure characteristics of the corpse to different degrees as well as show specific changes on computed tomography （CT） images, sometimes with false positives and false negatives, influencing the identification of injuries or diseases. This paper systematically summarizes the postmortem changes of computed tomography imaging characteristics on corpses, to further expand the application of virtopsy in the practices of forensic pathology identification, and provide reference for the identification of injuries, diseases and changes after normal death.

4284The combined use of radiofrequency-ablation and balloon-dilation (CURB) in the creation of a stable inter-atrial communication: first-in-man use for patients with severe pulmonary arterial hypertension

Background

Recent preclinical research has suggested that combined use of radiofrequency-ablation and balloon-dilation (CURB) had the potential to create a stable inter-atrial communication. However, the related clinical data is still absent.

Purpose

This study describes the first-in-man use of CURB in the patients with severe pulmonary arterial hypertension (PAH).

Methods

Under the guidance of fluoroscopy and intra-cardiac echocardiography, CURB was attempted in 3 patients with severe PAH (age: 35.0±12.1 years, one idiopathic PAH and two PAH related to repaired congenital heart disease). With the aid of 3D location system, fossae ovalis was ablated with radiofrequency. Then the graded balloon-dilation was performed after transseptal puncture, and radiofrequency-ablation was repeated around the rim of fenestration created with balloon-dilation. The exercise capacity and fenestration-size were followed up.

Results

CURB was performed successfully in all 3 patients, and pulmonary vascular resistance was 30.3±10.9 Wood units. The fenestration size was 5.0±1.0 mm (range: 4–6 mm), and systemic arterial oxygen saturation decreased by 4.7±0.6% (range: 4–5%). World Health Organization functional class increased by 1.6±0.5 (P<0.001) and cardiac index increased by 0.58±0.34 L/min/m2 (P<0.001). In addition, exercise capacity improved significantly (+63.7 meters, P<0.001). Follow-up (6.0±1.0 months; range: 5–7 months) showed that all fenestrations were stable (P=0.808), and no complication occurred.

Figure 1. The combined use of radiofrequency-ablation and balloon-dilation (CURB) was performed in the patient with severe PAH. Left figures showed the procedure of CURB. Middle figures showed the created fenestration with MSCT, and the morphology and size of fenestration was provided in the right-inferior panel. In addition, the sizes of right atrium and ventricle were alleviated with increase of left atrium. Right figures indicated that the fenestration-size was stable during follow-up (one week, one month and six months, respectively).

Conclusions

In patients with severe PAH, CURB is feasible and effective to create a stable inter-atrial communication. Further research was required to evaluate the long-term result of this novel approach.

ClinicalTrials.gov ID: NCT03554330.

Acknowledgement/Funding

National Natural Science Foundation of China (81670283) and Beijing Natural Science Foundation (7162160)

Whole-genome SNP data unravel population structure and signatures of selection for black plumage of indigenous chicken breeds from Jiangxi province, China

Ten indigenous chicken breeds were originally distributed in Jiangxi Province, China, and they define a critical component of Chinese chicken genetic resources. We have investigated the population genetics of seven Jiangxi chicken breeds using 600K chicken BeadChip SNP data. To provide a genome-wide perspective for the population structure of all 10 Jiangxi chicken breeds, we herein genotyped 78 additional individuals from the seven breeds and 63 chickens from three uninvestigated breeds-Yugan Black (YG), Nancheng Black (NC) and Wanzai Yellow using 55K chicken SNP arrays. We then explored merged data of 17 101 SNPs from 235 individuals to infer the population structure of the 10 breeds. We showed that NC and YG are two regional populations of the same breed, as individuals from the two populations clustered together to form a branch separate from the other breeds in the neighbor-joining tree, they always grouped together in multidimensional principal component analyses and they displayed an identical pattern of ancestral lineage composition. Hence, NC and YG should be considered a single breed in the state-supported conservation scheme. Moreover, we conducted a genome scan for signatures of selection for black plumage. bayescan and hapflk analyses of two contrasting groups (three black-feathered breeds vs. six non-black-feathered breeds) consistently detected 25 putative regions under selection. Nine pigmentation- associated genes (DCT, SLC24A5, SLC30A4, MYO5A, CYP19A1, NADK2, SLC45A2, GNAQ and DCP2) reside within these regions, and these genes are interesting candidates for black plumage and provide a starting point for further identification of causative mutations for black feathers in chicken.

Characteristic Changes and 3D Virtual Measurement of Lung CT Image Parameters in the Drowning Rabbit Model

OBJECTIVES

To use virtual anatomy technique in the analysis of post-mortem characteristic changes of CT images in the experimental drowning rabbit model and the related parameters in 3D virtual model, so as to explore its application value in the diagnosis of drowning in forensic pathology.

METHODS

A model of drowning rabbits was established, with animal models of hemorrhagic shock and mechanical asphyxia as the controls. CT scan was performed on the experimental animals, and the differences in imaging features between the groups were compared by morphological reading of the tomographic images. CT data were imported into Mimics 14.0 software for 3D modeling. The CT values and lung volumes were calculated by the software, and the differences on CT values and lung volumes brought by different causes of death were analyzed.

RESULTS

The CT images of lungs in the drowning group showed characteristic ground-glass opacity （diffuse and uniform density increase）. There were no obvious abnormalities in hemorrhagic shock group, and only a few similar changes were found in the mechanical asphyxia group. Compared with the controls, the CT values and the lung volumes in the drowning group were significantly increased P<0.05.

CONCLUSIONS

Based on post-mortem lung imaging, the combination of CT value and lung volume changes can effectively reflect the virtual anatomical features in drowning, and provide a diagnostic basis for the forensic identification of drowning.

Commercial Low-citrate Anticoagulation Haemofiltration in High Risk Patients with Frequent Filter Clotting

This study assessed the safety and efficacy of a commercial low-citrate concentration-based pre-filter replacement fluid during continuous veno-venous haemofiltration (CVVH) in patients with frequent filter clotting and high risk of bleeding. We used a commercial low-citrate fluid as pre-dilution replacement fluid during CVVH (citrate: 11 mmol/l (33 meq/l), sodium: 140 mmol/l, chloride: 108 mmol/l and potassium: 1 mmol/l). A calcium and magnesium infusion was delivered separately by central line for the maintenance of serum ionized calcium (Cai) and total magnesium (Mg). In this prospective observational study, 30 patients, 124 filters and 1,515 treatment-hours were observed. Median filter life of citrate CVVH was 9.5 hours. Filter life in the 48 hours prior to citrate CVVH was also observed. In the patients on prior non-anticoagulant CVVH (n=14) filter life increased significantly with citrate (9.5 hours vs 5 hours; P<0.0001). In patients on prior heparin CVVH (n=15), filter life was similar with citrate (10 hours vs 8 hours; P=0.68). However, in patients with prior early/frequent filter clotting despite heparin (n=11) filter life increased significantly (10 hours vs 7 hours; P=0.038). Of 411 serum Cai measurements, none showed a Cai<0.85 mmol/l and, of 84 observations, none showed a serum Mg<0.6mmol/l. One patient with sepsis and shock needed to cease citrate CVVH because of progressive ionized hypocalcaemia and increasing anion gap. No other adverse effects were observed. In selected patients, CVVH with a commercial low-citrate concentration solution as pre-filter replacement fluid and a simultaneous calcium and magnesium infusion protocol appears generally safe. Filter life was acceptable and superior to that achieved with previous treatment.

A Comparison of 4% Succinylated Gelatin Solution versus Normal Saline in Stable Normovolaemic Sheep: Global Haemodynamic, Regional Blood Flow and Oxygen Delivery Effects

The objective of this study was to compare the effects on regional blood flow and regional oxygen delivery of 4% succinylated gelatin solution (Gelofusine®, B. Braun) with those of normal saline. This was a randomised, controlled, crossover large animal study, which took place at the animal laboratory of university physiology institute. The subjects were seven merino cross-ewes.

We implanted flow probes around the aorta, coronary, renal and mesenteric arteries. We randomised animals to observation (control), normal saline (one litre over 15 minutes) or Gelofusine* (one litre over 15 minutes). We measured central haemodynamics, organ blood flows, arterial blood gases and haemoglobin every 30 minutes for 210 minutes.

Compared to control, both Gelofusine* and normal saline significantly and similarly increased mean arterial pressure, stroke volume, cardiac output and central venous pressure in the first hour (P <0.05). Such changes, however, were transient except for the increase in cardiac output seen with Gelofusine®. Normal saline significantly increased mesenteric blood flow in the first hour (P <0.05), while Gelofusine* caused a specific, sustained and progressive increase in renal blood flow and conductance (P <0.05). Both fluids increased urine output and creatinine clearance (P <0.05), but, due to haemodilution, both decreased renal oxygen delivery in the first hour (P <0.05).

Normal saline and Gelofusine® have transient, volume expansion-related systemic haemodynamic effects, which are greater for Gelofusine®. Saline had a more pronounced early effect on mesenteric blood flow, while Gelofusine* had a sustained and progressive greater effect on renal blood flow. The transient increase in urine output and creatinine clearance seen with both fluids occurred while renal oxygen delivery decreased.

Time-dependent Effects of Pressure during Preservation of Rat Hearts in an Isochoric System at Subfreezing Temperatures

BACKGROUND

Isochoric freezing systems enable ice-free preservation of biological matter at subfreezing temperatures under the increased hydrostatic pressure.

OBJECTIVE

To examine the effects of pressure and exposure period on rat hearts preserved in an isochoric chamber.

MATERIALS AND METHODS

Rat hearts were preserved in the UW solution in isochoric chambers at temperatures from -2°C to -8°C and pressure from the atmospheric level to 78 MPa for up to eight hours, with and without the addition of glycerol. Hearts were evaluated via Langendorff perfusion and HE histology.

RESULTS

Hearts were compromised quickly as pressure increased, suggesting an acute time-pressure sensitivity. With the addition of 1 M glycerol, which reduces the pressure experienced at a given temperature, the survival time at -4°C was doubled.

CONCLUSION

The enhanced hydrostatic pressure encountered during isochoric preservation yields time-dependent negative effects on the heart, which can potentially be alleviated by the addition of a cryoprotectant.

Assessment of the Original Height of L1~2 after Vertebral Compression Fracture

OBJECTIVES

To explore the assessment method of original height of L_1-2 after vertebral compression fracture and its application value in forensic clinical practice.

METHODS

A total of 154 normal thoracic and lumbar X-ray films were collected, and 140 cases were used as experimental group while 14 cases as validation group. The heights of anterior （Ha） and posterior （Hp） vertebral body of T₁₂-L₃ vertebrae in each X-ray image were measured. In the experimental group, the correlation analysis between Ha_L₁ and Ha_T₁₂, Hp_T₁₂, Hp_L₁, Ha_L₂ and Hp_L₂ was carried out, and regression equation was established via fitting. The correlation analysis between Ha_L₂ and Ha_L₁, Hp_L₁, Hp_L₂, Ha_L₃, Hp_L₃ was performed, and the regression equation was also established via fitting. The difference between the predicted and measured values of Ha_L₁ and Ha_L₂ in validation group was compared.

RESULTS

In the 140 normal subjects, Ha_L₁ （y₁） was well correlated with Ha_T₁₂ （x₁） and Ha_L₂（x₂）, and the multiple linear regression equation was y₁=2.545+0.423 x₁+0.486 x₂ （determining coefficient R²=0.712, P<0.05; F=169.206, P<0.05）. There was no significant difference between the predicted and actual measured values of Ha_L₁ in the validation group （ P>0.05）. HaL₂ （y₂） was well correlated with Ha_L₁ （x₃） and Ha_L₃ （x₄）, and the multiple linear regression equation was y₂=4.354+0.530 x₃+0.349 x₄ （determining coefficient R²=0.689, P<0.05; F=151.575, P<0.05）. There was no significant difference between the predicted and actual measured values of Ha_L₂ in the validation group （ P>0.05）.

CONCLUSIONS

It is more appropriate to evaluate the original height of L₁ or L₂ single vertebrae by comparing with the height of the anterior edge of the upper and lower adjacent vertebral bodies.