Importance of social vulnerability on long-term outcomes after heart transplantation.

The relationship between social determinants of health and outcomes after heart transplantation has not been examined. The social vulnerability index (SVI) uses United States census data to determine the social vulnerability of every census tract based on 15 factors. This retrospective study seeks to examine the impact of SVI on outcomes after heart transplantation. Adult heart recipients who received a graft between 2012 and 2021 were stratified into SVI percentiles of <75% and SVI of ≥75%. The primary endpoint was survival. The median SVI was 48% (interquartile range: 30%-67%) among 23 700 recipients. One-year survival was similar between groups (91.4 vs 90.7%, log-rank P = .169); however, 5-year survival was lower among individuals living in vulnerable communities (74.8% vs 80.0%, P < .001). This finding persisted despite risk adjustment for other factors associated with mortality (survival time ratio 0.819, 95% confidence interval: 0.755-0.890, P < .001). The incidences of 5-year hospital readmission (81.4% vs 75.4%, P < .001) and graft rejection (40.3% vs 35.7%, P = .004) were higher among individuals living in vulnerable communities. Individuals living in vulnerable communities may be at increased risk of mortality after heart transplantation. These findings suggest there is an opportunity to focus on these recipients undergoing heart transplantation to improve survival.

Analysis of protein-coding genetic variation in 60,706 humans.

Large-scale reference data sets of human genetic variation are critical for the medical and functional interpretation of DNA sequence changes. Here we describe the aggregation and analysis of high-quality exome (protein-coding region) DNA sequence data for 60,706 individuals of diverse ancestries generated as part of the Exome Aggregation Consortium (ExAC). This catalogue of human genetic diversity contains an average of one variant every eight bases of the exome, and provides direct evidence for the presence of widespread mutational recurrence. We have used this catalogue to calculate objective metrics of pathogenicity for sequence variants, and to identify genes subject to strong selection against various classes of mutation; identifying 3,230 genes with near-complete depletion of predicted protein-truncating variants, with 72% of these genes having no currently established human disease phenotype. Finally, we demonstrate that these data can be used for the efficient filtering of candidate disease-causing variants, and for the discovery of human 'knockout' variants in protein-coding genes.

Synergetic Induction of NGF With Diazoxide and Erythropoietin Attenuates Spinal Cord Ischemic Injury.

BACKGROUND: Paraplegia remains a significant complication of thoracoabdominal aortic intervention. We previously reported that diazoxide (DZ), enhances the neuroprotective efficacy of erythropoietin (EPO). We hypothesized that DZ and EPO combined treatment attenuates spinal cord ischemic injury through upregulation of nerve growth factor (NGF). METHODS: DZ (pretreatment) was given to adult male C57/BL6 mice by oral gavage and EPO (before surgery) was intraperitoneally injected 32 h after administration of DZ. Spinal cords were harvested 0, 2, 4, and 6 h after injection of EPO. NGF expression was analyzed by western blot. After determining the optimal time, NGF expression was compared between DZ (pretreatment) + EPO (before surgery), DZ + PBS, PBS + EPO, and PBS + PBS (ischemic control). Four groups were studied to compare the motor function after ischemia: DZ + EPO (n = 11), ischemic control (n = 9), DZ + EPO + tropomyosin receptor kinase A receptor inhibitor (n = 9), and sham (without cross-clamp, n = 4). Spinal cord ischemia was induced by a 4-min thoracic aortic cross-clamp. Functional scoring (Basso Mouse Score) was done at 12-h intervals until 48 h, and spinal cords were harvested for evaluation of NGF expression and histological changes. RESULTS: NGF expression was significantly upregulated 4 h after administration of EPO. At 4 h after injection of EPO, NGF expression in the DZ + EPO group was significantly higher than that in the other groups. DZ + EPO significantly preserved motor function compared with all other groups. At 48 h after reperfusion, the level of NGF expression in the DZ + EPO group, was significantly higher than in all other groups. CONCLUSIONS: DZ + EPO attenuates spinal cord ischemic injury through upregulation of NGF. Better understanding of this mechanism may serve to further prevent ischemic complications for aortic intervention.

The ExAC browser: displaying reference data information from over 60 000 exomes.

Worldwide, hundreds of thousands of humans have had their genomes or exomes sequenced, and access to the resulting data sets can provide valuable information for variant interpretation and understanding gene function. Here, we present a lightweight, flexible browser framework to display large population datasets of genetic variation. We demonstrate its use for exome sequence data from 60 706 individuals in the Exome Aggregation Consortium (ExAC). The ExAC browser provides gene- and transcript-centric displays of variation, a critical view for clinical applications. Additionally, we provide a variant display, which includes population frequency and functional annotation data as well as short read support for the called variant. This browser is open-source, freely available at http://exac.broadinstitute.org, and has already been used extensively by clinical laboratories worldwide.

Added Value of Computer-aided CT Image Features for Early Lung Cancer Diagnosis with Small Pulmonary Nodules: A Matched Case-Control Study.

Purpose To test whether computer-aided diagnosis (CAD) approaches can increase the positive predictive value (PPV) and reduce the false-positive rate in lung cancer screening for small nodules compared with human reading by thoracic radiologists. Materials and Methods A matched case-control sample of low-dose computed tomography (CT) studies in 186 participants with 4-20-mm noncalcified lung nodules who underwent biopsy in the National Lung Screening Trial (NLST) was selected. Variables used for matching were age, sex, smoking status, chronic obstructive pulmonary disease status, body mass index, study year of the positive screening test, and screening results. Studies before lung biopsy were randomly split into a training set (70 cancers plus 70 benign controls) and a validation set (20 cancers plus 26 benign controls). Image features from within and outside dominant nodules were extracted. A CAD algorithm developed from the training set and a random forest classifier were applied to the validation set to predict biopsy outcomes. Receiver operating characteristic analysis was used to compare the prediction accuracy of CAD with the NLST investigator's diagnosis and readings from three experienced and board-certified thoracic radiologists who used contemporary clinical practice guidelines. Results In the validation cohort, the area under the receiver operating characteristic curve for CAD was 0.9154. By default, the sensitivity, specificity, and PPV of the NLST investigators were 1.00, 0.00, and 0.43, respectively. The sensitivity, specificity, PPV, and negative predictive value of CAD and the three radiologists' combined reading were 0.95, 0.88, 0.86, and 0.96 and 0.70, 0.69, 0.64, and 0.75, respectively. Conclusion CAD could increase PPV and reduce the false-positive rate in the early diagnosis of lung cancer. © RSNA, 2017 Online supplemental material is available for this article.

Innominate Versus Axillary Artery Cannulation for the Hemiarch Repair.

BACKGROUND: Innominate artery cannulation has gained some popularity over the last decade as an alternative to axillary artery cannulation for providing selective antegrade cerebral perfusion during repair of the ascending aorta and arch. Innominate artery cannulation provides several advantages including avoidance of an additional incision and use of a larger caliber artery to provide less resistance to high flow during bypass and selective antegrade cerebral perfusion. We hypothesize that these advantages make innominate artery cannulation superior to axillary artery cannulation as it can decrease operative times and potentially decrease blood loss. METHODS: This was a single-center retrospective analysis of 206 patients who underwent hemiarch replacement between 2009 and 2017. All patients qualified including emergent cases. Groups were separated by mode of cannulation: axillary and innominate. Outcomes evaluated included cardiopulmonary bypass (CPB) time, cross-clamp time, circulatory arrest (CA) time, postoperative transfusions, intensive care unit length of stay, development of any neurological complications, end-organ failure, and mortality. Subgroup analysis was performed for elective and emergent cases. RESULTS: Axillary and innominate artery cannulation accounted for 37% (n = 77) and 67% (n = 129) of cases, respectively. There was no difference in patient characteristics except for a higher incidence of renal disease in the axillary group (16% versus 6%, P = 0.05). More emergent cases were performed in the axillary group (61% versus 17%, P < 0.001). Innominate cases had shorter CPB times (189 versus 150 min, P < 0.001) and CA (22.5 versus 11 min, P < 0.001) times overall. In the elective subgroup, CA times were shorter for the innominate cases. However, the emergent subgroup displayed no difference in operative times. Less transfusions were given in the innominate group including units of red blood cells (2 [0-6] versus 0 [0-2], P < 0.001), units of platelets (2 [1-3] versus 1 [0-2], P = 0.001), and units of plasma (6 [2-9] versus 2 [0-4], P < 0.001). A similar trend was observed in the elective subgroup. No difference in transfusions was observed in the emergent subgroup. There was no statistical difference in remaining outcomes between cases of axillary and innominate cannulation in the combined, elective, and emergent groups. CONCLUSIONS: Alternate cannulation strategies for open arch anastomoses are evolving with a trend toward using the innominate artery. These data suggest that innominate cannulation is at least equivalent to, and may be superior to, axillary cannulation. The innominate artery provides a larger conduit vessel for perfusion and this decrease in resistance to flow, allowing for faster cooling and rewarming, maybe why CPB times were lower in this group. Innominate cannulation is a safe and potentially advantageous technique for hemiarch repair.

Melanoma mimicking Rosai-Dorfman disease.

Despite well-defined clinical and histopathological features of melanoma, atypical presentations mimicking other skin disorders can result in a delayed diagnosis or misdiagnosis and subsequent inappropriate treatment. Rosai-Dorfman disease (RDD) is a rare histiocytic disorder with unique clinical and histopathological features. We report a case of melanoma treated with cryotherapy that mimicked RDD both clinically and histopathologically. We compare this RDD-like melanoma to classic RDD, outlining the importance of clinicopathological correlation prior to treatment, as well as the potential pitfalls in diagnosis after cryotherapy of pigmented lesions.

Mutations in PIGY: expanding the phenotype of inherited glycosylphosphatidylinositol deficiencies.

Glycosylphosphatidylinositol (GPI)-anchored proteins are ubiquitously expressed in the human body and are important for various functions at the cell surface. Mutations in many GPI biosynthesis genes have been described to date in patients with multi-system disease and together these constitute a subtype of congenital disorders of glycosylation. We used whole exome sequencing in two families to investigate the genetic basis of disease and used RNA and cellular studies to investigate the functional consequences of sequence variants in the PIGY gene. Two families with different phenotypes had homozygous recessive sequence variants in the GPI biosynthesis gene PIGY. Two sisters with c.137T>C (p.Leu46Pro) PIGY variants had multi-system disease including dysmorphism, seizures, severe developmental delay, cataracts and early death. There were significantly reduced levels of GPI-anchored proteins (CD55 and CD59) on the surface of patient-derived skin fibroblasts (∼20-50% compared with controls). In a second, consanguineous family, two siblings had moderate development delay and microcephaly. A homozygous PIGY promoter variant (c.-540G>A) was detected within a 7.7 Mb region of autozygosity. This variant was predicted to disrupt a SP1 consensus binding site and was shown to be associated with reduced gene expression. Mutations in PIGY can occur in coding and non-coding regions of the gene and cause variable phenotypes. This article contributes to understanding of the range of disease phenotypes and disease genes associated with deficiencies of the GPI-anchor biosynthesis pathway and also serves to highlight the potential importance of analysing variants detected in 5'-UTR regions despite their typically low coverage in exome data.

High-resolution study of the 3D collagen fibrillary matrix of Achilles tendons without tissue labelling and dehydrating.

Knowledge of the collagen structure of an Achilles tendon is critical to comprehend the physiology, biomechanics, homeostasis and remodelling of the tissue. Despite intensive studies, there are still uncertainties regarding the microstructure. The majority of studies have examined the longitudinally arranged collagen fibrils as they are primarily attributed to the principal tensile strength of the tendon. Few studies have considered the structural integrity of the entire three-dimensional (3D) collagen meshwork, and how the longitudinal collagen fibrils are integrated as a strong unit in a 3D domain to provide the tendons with the essential tensile properties. Using second harmonic generation imaging, a 3D imaging technique was developed and used to study the 3D collagen matrix in the midportion of Achilles tendons without tissue labelling and dehydration. Therefore, the 3D collagen structure is presented in a condition closely representative of the in vivo status. Atomic force microscopy studies have confirmed that second harmonic generation reveals the internal collagen matrix of tendons in 3D at a fibril level. Achilles tendons primarily contain longitudinal collagen fibrils that braid spatially into a dense rope-like collagen meshwork and are encapsulated or wound tightly by the oblique collagen fibrils emanating from the epitenon region. The arrangement of the collagen fibrils provides the longitudinal fibrils with essential structural integrity and endows the tendon with the unique mechanical function for withstanding tensile stresses. A novel 3D microscopic method has been developed to examine the 3D collagen microstructure of tendons without tissue dehydrating and labelling. The study also provides new knowledge about the collagen microstructure in an Achilles tendon, which enables understanding of the function of the tissue. The knowledge may be important for applying surgical and tissue engineering techniques to tendon reconstruction.

Whole-exome sequencing identifies rare, functional CFH variants in families with macular degeneration.

We sequenced the whole exome of 35 cases and 7 controls from 9 age-related macular degeneration (AMD) families in whom known common genetic risk alleles could not explain their high disease burden and/or their early-onset advanced disease. Two families harbored novel rare mutations in CFH (R53C and D90G). R53C segregates perfectly with AMD in 11 cases (heterozygous) and 1 elderly control (reference allele) (LOD = 5.07, P = 6.7 × 10(-7)). In an independent cohort, 4 out of 1676 cases but none of the 745 examined controls or 4300 NHBLI Exome Sequencing Project (ESP) samples carried the R53C mutation (P = 0.0039). In another family of six siblings, D90G similarly segregated with AMD in five cases and one control (LOD = 1.22, P = 0.009). No other sample in our large cohort or the ESP had this mutation. Functional studies demonstrated that R53C decreased the ability of FH to perform decay accelerating activity. D90G exhibited a decrease in cofactor-mediated inactivation. Both of these changes would lead to a loss of regulatory activity, resulting in excessive alternative pathway activation. This study represents an initial application of the whole-exome strategy to families with early-onset AMD. It successfully identified high impact alleles leading to clearer functional insight into AMD etiopathogenesis.

Matrix Gla protein regulates calcification of the aortic valve.

BACKGROUND: The aortic valve interstitial cell (AVIC) has been implicated in the pathogenesis of aortic stenosis. In response to proinflammatory stimulation, the AVIC undergoes a phenotypic change from that of a myofibroblast phenotype to that of osteoblast-like cell. Matrix Gla-protein (MGP) has been identified as an important inhibitor of vascular calcification. We therefore hypothesized that MGP expression is reduced in diseased AVICs, and loss of this protective protein contributes to calcification of the aortic valve. Our purpose was to compare MGP expression in normal versus diseased AVICs. MATERIALS AND METHODS: Human AVICs were isolated from normal aortic valves from explanted hearts (n = 6) at the time of heart transplantation. AVICs were also isolated from calcified, diseased valves of patients (n = 6) undergoing aortic valve replacement. AVICs were grown in culture until they reached passages 2-6 before experimentation. Immunofluorescent staining, reverse transcriptase-polymerase chain reaction, immunoblotting, and enzyme-linked immunosorbent assay were used to compare levels of MGP in normal and diseased AVICs. Statistics were performed using the Mann-Whitney U test (P < 0.05). RESULTS: MGP expression was significantly decreased in diseased AVICs relative to normal AVICs by immunofluorescent staining, reverse transcriptase-polymerase chain reaction, immunoblotting, and enzyme-linked immunosorbent assay. CONCLUSIONS: An important anti-calcification defense mechanism is deficient in calcified aortic valves. MGP expression is significantly lower in diseased relative to normal AVICs. Lack of this important "anti-calcification" protein may contribute to calcification of the aortic valve.

Participants' Views of Retention Materials Used in the PLCO Cancer Screening Trial.

OBJECTIVE: To obtain information from participants in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial regarding their perception of the retention materials employed by the screening centers. Also, to determine the viability of using email or the internet as a data collection tool with an older population. DESIGN: Three of ten PLCO screening centers queried participants towards the end of the study (2010) as to their opinions of the various retention materials and whether they would have been willing to use electronic communication for study activities, had the option been available. SETTING: The questionnaires were administered by mail, and responses were returned to the originating screening center. PARTICIPANTS: The participants in this study consisted of all the active participants at three PLCO screening centers: the University of Colorado Anschutz Medical Campus, the University of Utah, and Henry Ford Health System. METHODS: A short, self-administered questionnaire was mailed to all active participants at three PLCO centers (n=41,482). This was a one-time mailing with no follow-up, as the responses were designed to be anonymous in order to obtain the most honest responses. RESULTS: The response rate was 62%. Of respondents, 97% reported their PLCO experience was good or excellent. Nearly 50% of respondents indicated that receipt of an annual newsletter made them more likely to participate; newsletter features they reported as most important were those that conveyed information on cancer, study findings, and how their data were being used. Results did not support study coordinators' suppositions that receipt of a token gift or birthday card by participants was important for retention. Fewer than 30% of respondents indicated that they would have been unwilling to use a secure website to complete study forms. CONCLUSION: These data indicate the importance of querying participants rather than relying on impressions of study staff, and also indicate that the internet will be a viable means of data collection in future prevention studies that include older Americans.

Aortic valve calcification is mediated by a differential response of aortic valve interstitial cells to inflammation.

BACKGROUND: Although calcific aortic stenosis is common, calcification of the other three heart valves is not. The aortic valve interstitial cell (VIC) has been implicated in the pathogenesis of aortic stenosis. Proinflammatory stimulation of aortic VICs induces an osteogenic and inflammatory phenotypic change. We hypothesized that the VICs of the other heart valves do not undergo these changes. Using isolated human VICs from normal aortic, mitral, pulmonary, and tricuspid valves, our purpose was to compare the osteogenic response to proinflammatory stimulation via toll-like receptor 4 (TLR-4). MATERIALS AND METHODS: Aortic, pulmonic, mitral, and tricuspid (n=4 for each valve type) VICs were isolated from hearts valves explanted from patients undergoing cardiac transplantation. Cells were cultured and grown to confluence in passage 2-6 before treatment with Lipopolysaccharide (LPS) (100-200 ng/mL) for 24 or 48 h. Cells were characterized by immunofluorescent staining. TLR-4 expression was analyzed (immunoblotting, flow cytometry). Bone morphogenetic protein 2 and intercellular adhesion molecule 1 production were determined (immunoblotting). Monocyte chemoattractant protein 1 levels were determined by enzyme-linked immunosorbent assay. Statistics were by Mann-Whitney U test. RESULTS: TLR-4 stimulation induced bone morphogenetic protein 2 production only in aortic VICs (P<0.05). Intra-cellular adhesion molecule 1 production and monocyte chemoattractant protein 1 secretion increased in a similar fashion among TLR-4-stimulated VICs from all four valves. CONCLUSIONS: Proinflammatory stimulation induces an osteogenic phenotype in aortic VICs but not mitral, pulmonic, or tricuspid VICs. We conclude that this differential osteogenic response of aortic VICs contributes to the pathogenesis of calcific aortic stenosis.

Non-compliance with the initial screening exam visit in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial.

OBJECTIVE: Identify predictors of non-compliance with first round screening exams in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. METHOD: The PLCO was conducted from 1993 to 2011 at 10 US institutions. A total of 154,897 healthy men and women ages 55-74 years were randomized. Intervention arm participants were invited to receive gender-appropriate screening exams for prostate, lung, colorectal and ovarian cancer. Using intervention-arm data (73,036 participants), non-compliance percentages for 13 covariates were calculated, as were unadjusted and adjusted odds ratios (ORs), and 95% confidence intervals. Covariates included demographic factors as well as factors specific to PLCO (e.g., method of consent, distance from screening center). RESULTS: The rate of non-compliance was 11% overall but varied by screening center. Significant associations were observed for most covariates but indicated modest increases or decreases in odds. An exception was the use of a two-step consent process (consented intervention arm participants for exams after randomization) relative to a one-step process (consented all participants prior to randomization) (OR: 2.2, 95% CI: 2.0-2.5). Non-compliance percentages increased with further distance from screening centers, but ORs were not significantly different from 1. CONCLUSIONS: Many factors modestly influenced compliance. Consent process was the strongest predictor of compliance.

Why Opportunities for Tenure Matter for Minoritized Faculty in Academic Medicine.

Academic medicine continues to characterize the experiences of Black and other minoritized faculty in medicine to enhance their careers and promote their advancement. An issue of discussion is tenure and its role in the advancement and retention of this group. Tenure is a sign of national presence, command of an area of study, and can demonstrate support from the institution in terms of permanent employment, eligibility to apply for awards, sit or vote on certain committees or qualify for certain leadership opportunities. Anecdotally there have been reports that tenure is a thing of the past that has lost relevance prompting some to end tenure in their institutions. Reasons for this are complex, however the literature does not include minoritized faculty as a reason for the need to revise or eliminate tenure and tenure earning tracks. The authors discuss 3 reasons why Black and other minoritized faculty should be afforded the opportunity to achieve permanent status in their academic health centers. They include histories of being denied freedom, having information concealed or being giving false information, and being denied permanent academic employment status.

INRICH: interval-based enrichment analysis for genome-wide association studies.

SUMMARY: Here we present INRICH (INterval enRICHment analysis), a pathway-based genome-wide association analysis tool that tests for enriched association signals of predefined gene-sets across independent genomic intervals. INRICH has wide applicability, fast running time and, most importantly, robustness to potential genomic biases and confounding factors. Such factors, including varying gene size and single-nucleotide polymorphism density, linkage disequilibrium within and between genes and overlapping genes with similar annotations, are often not accounted for by existing gene-set enrichment methods. By using a genomic permutation procedure, we generate experiment-wide empirical significance values, corrected for the total number of sets tested, implicitly taking overlap of sets into account. By simulation we confirm a properly controlled type I error rate and reasonable power of INRICH under diverse parameter settings. As a proof of principle, we describe the application of INRICH on the NHGRI GWAS catalog. AVAILABILITY: A standalone C++ program, user manual and datasets can be freely downloaded from: http://atgu.mgh.harvard.edu/inrich/.

Optimizing Nicorandil for Spinal Cord Protection in a Murine Model of Complex Aortic Intervention.

There are currently no clinically utilized pharmacological agents for the induction of metabolic tolerance to spinal cord ischemia-reperfusion injury in the setting of complex aortic intervention. Nicorandil, a nitric oxide donor and ATP-sensitive potassium (KATP) channel opener, has shown promise in neuroprotection. However, the optimized clinical application of the drug and its mechanism of neuroprotection remains unclear. We hypothesized that 3-days pretreatment would confer the most effective neuroprotection, mediated by mitochondrial KATP channel activation. Spinal cord injury was induced by 7 minutes of thoracic aortic cross-clamping in adult male C57BL/6 mice. Time course: mice received 0.1 mg/kg nicorandil for 10 min, 4 hours, and 3 consecutive days prior to ischemia compared with control. Dose challenge: mice received 3-days nicorandil pretreatment comparing 0.1 mg/kg, 1.0 mg/kg, 5.0 mg/kg, and saline administration. Mitochondrial KATP channel blocker 5-hydroxy-decanoate (5HD) was co-administered to elucidate mechanism. Limb motor function was evaluated, and viable anterior horn neurons quantified. Nicorandil pretreatment at 4 hours and 3 days before ischemia demonstrated significant motor function preservation; administration 10 minutes before ischemia showed no neuroprotection. All nicorandil doses showed significant motor function preservation. Three days administration of Nicorandil 1.0 mg/kg was most potent. Neuroprotection was completely abolished by 5HD co-administration. Histological analysis showed significant neuron preservation with nicorandil pretreatment, which was attenuated by 5HD co-administration. Three days administration of Nicorandil 1.0 mg/kg showed near-total motor function preservation in a murine spinal cord ischemia-reperfusion model, mediated by the mitochondrial KATP channel.

Injectable and Self-Healing Hydrogels with Double-Dynamic Bond Tunable Mechanical, Gel-Sol Transition and Drug Delivery Properties for Promoting Periodontium Regeneration in Periodontitis.

Injection of a hydrogel loaded with drugs with simultaneous anti-inflammatory and tissue regenerating properties can be an effective treatment for promoting periodontal regeneration in periodontitis. Nevertheless, the design and preparation of an injectable hydrogel with self-healing properties for tunable sustained drug release is still highly desired. In this work, polysaccharide-based hydrogels were formed by a dynamic cross-linked network of dynamic Schiff base bonds and dynamic coordination bonds. The hydrogels showed a quick gelation process, injectability, and excellent self-healing properties. In particular, the hydrogels formed by a double-dynamic network would undergo a gel-sol transition process without external stimuli. And the gel-sol transition time could be tuned by the double-dynamic network structure for in situ stimuli involving a change in its own molecular structure. Moreover, the drug delivery properties were also tunable owing to the gel-sol transition process. Sustained drug release characteristics, which were ascribed to a diffusion process, were observed during the first stage of drug release, and complete drug release owing to the gel-sol transition process was achieved. The sustained drug release time could be tuned according to the double-dynamic bonds in the hydrogel. The CCK-8 assay was used to evaluate the cytotoxicity, and the result showed no cytotoxicity, indicating that the injectable and self-healing hydrogels with double-dynamic bond tunable gel-sol transition could be safely used in controlled drug delivery for periodontal disease therapy. Finally, the promotion of periodontal regeneration in periodontitis in vivo was investigated using hydrogels loaded with ginsenoside Rg1 and amelogenin. Micro-CT and histological analyses indicated that the hydrogels were promising candidates for addressing the practical needs of a tunable drug delivery method for promoting periodontal regeneration in periodontitis.

A review of methods to measure tendon dimensions.

Tendons are soft tissues of the musculoskeletal system that are designed to facilitate joint movement. Tendons exhibit a wide range of mechanical properties matched to their functions and, as a result, have been of interest to researchers for many decades. Dimensions are an important aspect of tendon properties.Change in the dimensions of tissues is often seen as a sign of injury and degeneration, as it may suggest inflammation or general disorder of the tissue. Dimensions are also important for determining the mechanical properties and behaviours of materials, particularly the stress, strain, and elastic modulus. This makes the dimensions significant in the context of a mechanical study of degenerated tendons. Additionally, tendon dimensions are useful in planning harvesting for tendon transfer and joint reconstruction purposes.Historically, many methods have been used in an attempt to accurately measure the dimensions of soft tissue, since improper measurement can lead to large errors in the calculated properties. These methods can be categorised as destructive (by approximation), contact, and non-contact and can be considered in terms of in vivo and ex vivo.