A screen for regeneration-associated silencer regulatory elements in zebrafish

Regeneration involves gene expression changes explained in part by context-dependent recruitment of transcriptional activators to distal enhancers. Silencers that engage repressive transcriptional complexes are less studied than enhancers and more technically challenging to validate, but they potentially have profound biological importance for regeneration. Here, we identified candidate silencers through a screening process that examined the ability of DNA sequences to limit injury-induced gene expression in larval zebrafish after fin amputation. A short sequence (s1) on chromosome 5 near several genes that reduce expression during adult fin regeneration could suppress promoter activity in stable transgenic lines and diminish nearby gene expression in knockin lines. High-resolution analysis of chromatin organization identified physical associations of s1 with gene promoters occurring preferentially during fin regeneration, and genomic deletion of s1 elevated the expression of these genes after fin amputation. Our study provides methods to identify "tissue regeneration silencer elements" (TRSEs) with the potential to reduce unnecessary or deleterious gene expression during regeneration.

Activation of Lactate Receptor Positively Regulates Skeletal Muscle Mass in Mice

G protein-coupled receptor 81 (GPR81), a selective receptor for lactate, expresses in skeletal muscle cells, but the physiological role of GPR81 in skeletal muscle has not been fully elucidated. As it has been reported that the lactate administration induces muscle hypertrophy, the stimulation of GPR81 has been suggested to mediate muscle hypertrophy. To clarify the contribution of GPR81 activation in skeletal muscle hypertrophy, in the present study, we investigated the effect of GPR81 agonist administration on skeletal muscle mass in mice. Male C57BL/6J mice were randomly divided into control group and GPR81 agonist-administered group that received oral administration of the specific GPR81 agonist 3-Chloro-5-hydroxybenzoic acid (CHBA). In both fast-twitch plantaris and slow-twitch soleus muscles of mice, the protein expression of GPR81 was observed. Oral administration of CHBA to mice significantly increased absolute muscle weight and muscle weight relative to body weight in the two muscles. Moreover, both absolute and relative muscle protein content in the two muscles were significantly increased by CHBA administration. CHBA administration also significantly upregulated the phosphorylation level of p42/44 extracellular signal-regulated kinase-1/2 (ERK1/2) and p90 ribosomal S6 kinase (p90RSK). These observations suggest that activation of GRP81 stimulates increased the mass of two types of skeletal muscle in mice in vivo. Lactate receptor GPR81 may positively affect skeletal muscle mass through activation of ERK pathway.

Alzheimer PHF-tau aggregates do not spread tau pathology to the brain via the Retino-tectal projection after intraocular injection in mouse models

Neurofibrillary tangles (NFT), a neuronal lesion found in Alzheimer's disease (AD), are composed of fibrillary aggregates of modified forms of tau proteins. The propagation of NFT follows neuroanatomical pathways suggesting that synaptically connected neurons could transmit tau pathology by the recruitment of normal tau in a prion-like manner. Moreover, the intracerebral injection of pathological tau from AD brains induces the seeding of normal tau in mouse brain. Creutzfeldt-Jacob disease has been transmitted after ocular transplants of cornea or sclera and the scrapie agent can spread across the retino-tectal pathway after intraocular injection of scrapie mouse brain homogenates. In AD, a tau pathology has been detected in the retina. To investigate the potential risk of tau pathology transmission during eye surgery using AD tissue material, we have analysed the development of tau pathology in the visual pathway of mice models expressing murine tau, wild-type or mutant human tau after intraocular injection of pathological tau proteins from AD brains. Although these pathological tau proteins were internalized in retinal ganglion cells, they did not induce aggregation of endogenous tau nor propagation of a tau pathology in the retino-tectal pathway after a 6-month incubation period. These results suggest that retinal ganglion cells exhibit a resistance to develop a tau pathology, and that eye surgery is not a major iatrogenic risk of transmission of tau pathology, contrary to what has been observed for transmission of infectious prions in prion diseases.

Temporal course of vascular response after fluoropolymer paclitaxel-eluting stent implantation for femoropopliteal artery lesions

Background

Limited data is available regarding the vascular response after fluoropolymer paclitaxel-eluting stent (FP-PES) implantation. We sought to assess the vascular response at 6- and 12-month after FP-PES implantation for femoropopliteal artery lesions using serial optical coherence tomography (OCT) examination.

Methods and results

From the IMPERIAL trial, this study evaluated 10 de novo femoropopliteal lesions treated with FP-PES. The primary study endpoint was neointimal tissue coverage at 6- and 12-month follow-up as assessed by serial OCT examination. The incidence of peri-strut low-intensity area (PLIA) and extra-stent lumen (ESL) was also assessed. A total of 203 matched cross-sectional images were evaluated at 6- and 12-month (5,615 and 5,763 struts, respectively). From 6 to 12 months, the mean neointimal thickness tended to increase from 198 μm to 233 μm with a significant reduction in the incidence of malapposed struts (0.59% vs. 0.28%, p=0.039). Conversely, uncovered struts and PLIA were more frequently observed at 12 months (4.4% vs. 7.8%, p=0.01; 12.7% vs. 21.0%, p<0.001, respectively). The ESL area significantly increased over time without any difference in its incidence (0.24±0.32 mm2 vs. 0.38±0.36 mm2, p=0.009).

Conclusions

Neointimal proliferation was markedly inhibited from 6 to 12 months after FP-PES implantation, whereas the incidence of uncovered struts and PLIA significantly increased over time with the enlargement of ESL.

Funding Acknowledgement

Type of funding sources: None.

A systematic review of patient-reported outcome measures used to assess sleep in postpartum women using Consensus Based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines

STUDY OBJECTIVES

We performed a systematic review to identify the best patient-reported outcome measure (PROM) of postpartum sleep in women.

METHODS

We searched 4 databases for validated PROMs used to assess postpartum sleep. Studies were considered if they evaluated at least 1 psychometric measurement property of a PROM. An overall rating was assigned for each psychometric measurement property of each PROM based upon COSMIN criteria. A modified GRADE approach was used to assess the level of evidence and recommendations were then made for each PROM.

RESULTS

We identified 15 validation studies of 8 PROMs, in 9,070 postpartum women. An adequate number of sleep domains was assessed by 5 PROMs: Bergen Insomnia Scale (BIS), Pittsburgh Sleep Quality Index (PSQI), General Sleep Disturbance Scale (GSDS), Athens Insomnia Scale (AIS) and the Sleep Symptom Checklist (SSC). BIS and GSDS were the only PROMs to demonstrate adequate content validity and at least a low level of evidence of sufficient internal consistency, resulting in Class A recommendations. The BIS was the only PROM, which is easily accessible and free to use for non-commercial research, that achieved a Class A recommendation.

CONCLUSION

The BIS is the best currently available PROM of postpartum sleep. However, this PROM fails to assess several important domains such as sleep duration (and efficiency), chronotype, sleep-disordered breathing and medication usage. Future studies should focus on evaluating the psychometric measurement properties of BIS in the North American setting and in different cultural groups, or to develop a more specific PROM of postpartum sleep.

Impact of tapered-shaped left ventricular outflow tract on permanent pacemaker implantation after the third-generation balloon-expandable valve implantation

Background

In the era of transcatheter aortic valve implantation (TAVI) for patients with lower surgical risk, conduction disturbances requiring permanent pacemaker implantation (PPI) after TAVI remain a serious concern. The association between tapered-shaped left ventricular outflow tract (LVOT) and PPI after TAVI has not been elucidated.

Purposes

This study sought to identify predictors for PPI after TAVI with the third-generation balloon-expandable valve, with focus on LVOT morphology.

Methods

Of 272 consecutive patients treated with the third-generation balloon-expandable valve, 256 patients without previous PPI or bicuspid valve were retrospectively analyzed.

Results

PPI was implanted after TAVI in 20 (7.8%) patients. Patients requiring PPI had smaller LVOT area (356.3 mm2 vs. 399.4 mm2, p=0.011). Moreover, receiver-operating characteristic (ROC) statistics showed that LVOT area /annulus area possessed significantly higher predictive ability than LVOT area (area under the curve: 0.91 [95% confidence interval [CI]: 0.84 to 0.95] vs. 0.67 [95% CI: 0.57 to 0.77], p<0.001). Multivariable analysis revealed LVOT area /annulus area (odds ratio [OR]: 1.93 [95% CI: 1.38–2.71]; p<0.001 per % of decreasing), the difference between membranous septum length and implantation depth (ΔMSID) (OR: 6.82 [95% CI 2.39–19.48]; p<0.001 per mm of decreasing) and pre-existing complete right bundle branch block (CRBBB) (OR: 32.38 [95% CI 2.30–455.63]; p=0.002) as independent predictors of PPI. Further analysis using ROC statistics revealed LVOT area / annulus area of 88.5% and ΔMSID of 1.8 mm as the optimal cutoff points for prediction of PPI after the third-generation balloon-expandable valve implantation, with high negative predictive values of 98.1% and 99.0%, respectively. Figure shows the PPI rates stratified by the number of following predictors: LVOT area /annulus area <88.5%, ΔMSID <1.8 mm and pre-existing CRBBB. Patients with 2 or more predictors had significantly higher PPI rates than those with 1 or less predictor (67% [18 of 27 patients] vs. 1% [2 of 229 patients], p<0.001).

Conclusions

LVOT area /annulus area, ΔMSID and pre-existing CRBBB were identified as powerful independent predictors for PPI after TAVI. Higher valve implantation is important to prevent excessive PPI especially for patients with pre-procedural tapered-shaped LVOT, short membranous septum or pre-existing CRBBB.

PPI rates stratified by predictors

Funding Acknowledgement

Type of funding source: None

Impact of SYNTAX score 2 on 7-year clinical outcomes in patients treated with cobalt-chromium everolimus-eluting stent

Background

Impact of SYNTAX score II (SSII) on long-term clinical outcomes after cobalt-chromium everolimus-eluting stent (CoCr-EES) implantation remains unclear.

Methods

Between February 2010 and May 2011, 1064 consecutive patients with 1440 lesions were treated only with CoCr-EES implantation. Of these, the SSII was calculated in 1013 patients with 1345 lesions. Patients were divided into the tertile group: Tertiles for SSII (low SSII [12–28.9], n=334; intermediate SSII [29–39.1], n=339; and high SSII [39.2–80.8], n=340). We assessed the cumulative 7-year incidences of major adverse cardiac events (MACE), defined as a composite of cardiac death, myocardial infarction, definite stent thrombosis, and clinically driven target lesion revascularization (CDTLR) based on SSII groupings.

Results

Cumulative 7-year incidence of MACE was significantly higher in the high SSII group than in the other groups (34.1% vs. 18.6% vs. 17.2%, p<0.001). The cumulative incidence of cardiac death, myocardial infarction and stent thrombosis were significantly higher in the high SSII group than in the other groups (22.1% vs. 2.0% vs. 5.3%, p<0.001; 6.6% vs. 4.9% vs. 1.7%, p=0.01; 2.9% vs. 1.7% vs. 0.3%, p=0.03, respectively). The cumulative incidence of CDTLR was similar between the groups (15.2% vs. 12.8% vs. 15.7%, p=0.57). High SSII group (hazard ratio [HR] 2.18 [vs. low SS], 95% confidence intervals [CI]: 1.56–3.06, p<0.001) and diabetes mellitus (HR 1.37, 95% CI: 1.04–1.81, p=0.03) were predictors of 7-year MACE.

Conclusions

SSII has significantly impact on 7 years clinical outcomes after CoCr-EES implantation.

Cumulative incidence of MACE

Funding Acknowledgement

Type of funding source: None

Different clinical features between left atrial and left atrial appendage thrombus: an insight into more than 16,000 transesophageal echography database

Background

Thrombosis localization inside the left atrium (LA) is very frequently in the left atrial appendage (LAA). Some cases show atrial thrombus outside LAA, whose characteristics have not well elucidated.

Purpose

To reveal the different clinical background between thrombus inside LAA and outside LAA in a large transesophageal echo (TEE) database.

Methods

We searched the TEE database over 8 years of our center to identify patients in whom LA thrombus was pointed out. After initial TEE imaging, LA thrombus was confirmed with repeated TEE by echocardiography specialist or other modality, such as CT images.

Results

In a consecutive 16,142 TEE cases, LA thrombus was suspected in 162 cases (1%), finally 38 cases were identified as LA thrombus. They were divided into two groups; LAA only group and outside LAA group. Atrial fibrillation was concomitant in 34 patients (89%). History of stroke was significantly higher in LAA group (46.2% vs 8.3%, p=0.03) and malignant tumor was significantly higher in outside LAA group (23.1% vs 58.3%, p=0.035). LA thrombus was the first symptom in 3 cases of outside LAA group, following by malignant tumor was newly detected. Oral anticoagulation was prescribed in 23 cases (61%) at TEE study, mostly treated with warfarin, and median 123 days later thrombus dissolution was confirmed in 21 cases (55%). During mean follow up of 893 days, 4 patients experienced ischemic stroke, but two of them were due to self-interruption.

Conclusion

Outside LAA thrombus is minor but more concomitant with malignant tumor. Physician must be aware that screening of cancer is important if outside LAA thrombus is detected.

Funding Acknowledgement

Type of funding source: None

Serum Lipoprotein(a) levels on clinical outcomes after endovascular therapy

Background

While lipoprotein (a) (Lp(a)) is an independent predictor of atherosclerotic diseases involving the coronary and cerebrovascular arteries, its prognostic value in patients with peripheral artery disease (PAD) remains still unclear.

Objective

The aim of study is to determine the role of Lp(a) levels after endovascular therapy (EVT).

Methods

This study was prospective observational study. From September 2016 to April 2019, 676 the patients (873 limbs) who underwent EVT for de-novo PAD were enrolled. We divided into Lp(a) levels ≥40 mg/dl (high Lp(a) group; n=129) and <40 mg/dl (low Lp(a) group; n=547). Outcome measures were major adverse cardiovascular events (MACE; all-cause death, myocardial infarction and stroke), and major adverse limb events (MALE; repeat revascularization for limb and major amputation) at 1 year. Major amputation defined as above forefoot amputation due to vascular cause.

Results

The mean follow-up period was 14.3±8.9 months. Serum Lp(a) levels before EVT were 27.2 (10.0–36.0 mg/dl). High Lp (a) group was significantly older, higher prevalence of history of stroke, chronic kidney disease, and multi-vessel lesions. Cumulative incidence of MACE at 1 year was not significantly between two groups (p=0.53, log-rank test), whereas cumulative incidence of MALE at 1 year was significantly higher in high Lp (a) group (p=0.04, log-rank test). However, after adjusting for prespecified risk factors, high Lp (a) group was not independent predictor in MALE at 1 year.

Conclusion

High Lp (a) might not be associated with cardiovascular events and limb prognosis after EVT for PAD in early phase.

Funding Acknowledgement

Type of funding source: None

High-risk plaque burdens myocardial flow reserve in intermediate coronary artery disease: hybrid analysis of 13N-ammonia PET and coronary CT angiography

Background

13N-ammonia PET (NH3-PET) can detect myocardial perfusion abnormalities in patients with coronary artery disease (CAD) and also obtain diagnostic quantitative values of absolute myocardial blood flow and myocardial flow reserve (MFR). Low MFR (MFR<2.0) is an independent prognostic factor for major adverse cardiac event in patients with ischemic and non-ischemic heart disease. A feature of low attenuation plaque (LAP) on coronary CT angiography (CCTA) has been known as high-risk plaque (HRP) for acute coronary syndrome even if there is no significant coronary stenosis. The presence of HRP potentially adversely affects MFR, but the hypothesis has not been elucidated.

Purpose

We aimed to investigate the affect of LAP to MFR in intermediate CAD.

Methods

One hundred five patients (age 67±9 years, 65% male) with CAD underwent NH3-PET and CCTA within 6 months between April 2015 and March 2019 were enrolled. Based on the results of CCTA, mild and moderate stenosis were defined as 1% to 49% and 50% to 69% stenosis. Ischemic territories for major three vessels were identified by stress/rest NH3-PET images. Finally, 194 coronary arteries with mild to moderate stenosis corresponding to non-ischemic territory were analyzed in this study. LAP was defined as plaques containing CT value less than 90HU. Partially calcified plaques were included in LAP. Entirely calcification plaque without LAP was defined as calcified plaque. MFR for major three vessels were calculated from dynamic scan at stress/rest NH3-PET.

Results

CCTA showed 80 coronary arteries with LAP (41%), 104 coronary arteries with calcified plaque (54%), 102 vessels with mild stenosis (53%), and 92 vessels with moderate stenosis (47%). MFRs for coronary arteries with LAP were significantly lower than those without LAP (2.1±0.6 vs 2.5±0.6, p<0.0001). The significant difference in MFR between with and without LAP was observed in both mild and moderate stenosis (mild: 2.0±0.6 vs 2.5±0.6, p=0.0015, moderate: 2.1±0.6 vs 2.5±0.6, p<0.0001). In contrast, coronary arteries with calcified plaque had significantly higher MFR than those without (2.5±0.6 vs 2.1±0.6, p<0.0001).

In 58 coronary arteries with MFR<2.0, 71% (41/58) had LAP and 24% (14/58) had calcified plaque. In 136 coronary arteries with MFR≥2.0, 29% (39/136) had LAP and 66% (90/136) had calcified plaque. LAP was significantly more frequent in the former and calcified plaque was significantly more frequent in the latter.

Conclusion

The presence of LAP burdens MFR in mild to moderate CAD. On the other hand, calcified plaque alone had no adverse effect on MFR. LAP is an important sign in CAD risk assessment even without significant coronary stenosis.

MFR and stress MPI

Funding Acknowledgement

Type of funding source: None

P2716Correlation between computed tomography derived ischemia index and conventional fractional flow reserve

Background

Computed tomography (CT) derived ischemia index is a novel tool to determine the significance of coronary artery disease, however, its ability to identify myocardial ischemia has not been examined.

Methods

From Jan. 2013 to Dec. 2015, 14,000 patients underwent ECG-gated CT coronary angiography for suspected coronary artery disease. From Jan. 2013 to Jan. 2016, 483 patients (589 vessels) underwent conventional FFR to assess myocardial ischemia. Among those, FFR was assessed in 148 patients (167 vessels) within 30 days after CT coronary angiography. We further excluded 24 patients with prior stenting or bypass grafting, 3 patients with multiple MDCT or FFR, and 6 patients with insufficient datasets. Finally, we included 117 patients (127 vessels) to assess the correlation between CT derived ischemia index and conventional FFR.

CT derived ischemia index was calculated as follows: left ventricular volume distally to the coronary artery lumen (cm3)/coronary artery lumen area (mm2). Left ventricular volume was automatically determined using Advantage Workstation and divided according to the nearest coronary artery tree. Center of coronary arteries were manually traced and contours of coronary artery lumen were automatically depicted. CT derived ischemia index was calculated at approximately every 0.625mm point of coronary artery. Moving median of consecutive 5 points (approximately 3.125mm) were used to remove outliers. Maximum value of CT derived ischemia index per coronary artery segment was calculated to determine the significance of coronary artery disease.

Results

Mean age was 71.3±10.5 years and 63.8% of patients were male. Coronary angiography was performed to assess conventional FFR at the median of 13 days (IQR 7 to 18 days) after CT. Majority of the target vessel was left anterior descending artery (71.7%), followed by right coronary artery (14.2%), left circumflex artery (13.4%) and left main coronary artery (0.8%). According to the quantitative coronary angiography, minimum lumen diameter was 1.47±0.32mm with percent diameter stenosis of 48.3±10.4%. Median FFR value was 0.83 (IQR 0.76 to 0.88) and positive test for myocardial ischemia (FFR <0.80) was observed in 42 vessels (33.1%). Maximum CT derived ischemia index per segment ranged from 1.825 to 57.296 (median 8.333, IQR 4.911 to 14.484). There was a negative correlation between CT derived ischemia index and FFR (r=−0.319, 95% confidence interval −0.467 to −0.153, P<0.001). Receiver operating characteristic analysis indicated CT derived ischemia index of 9.962 has 76.2% sensitivity and 70.6% specificity for the presence of FFR<0.80 (AUC 0.73, 95% CI 0.64 to 0.82).

Conclusions

A novel tool of CT derived ischemia index has a significant negative correlation with conventional FFR in lesions with mild to moderate stenosis. Larger multicenter prospective studies are needed to fully determine the impact of CT derived ischemia index.

P6355The behavior of atrial fibrillation in patients with heart failure hospitalization

Background

Relationship between atrial fibrillation (AF) and heart failure (HF) is often compared with proverbial question of which came first, the chicken or the egg. Some patients showing AF at the HF admission result in restoration of sinus rhythm (SR) at discharge. It is not well elucidated that the restoration into SR during hospitalization can render the preventive effect for rehospitalization.

Purpose

To investigate the impact of restoration into SR during hospitalization for readmission rate of the HF patients showing AF.

Methods

We enrolled consecutive 640 HF patients hospitalized from January 2015 to December 2015. Patients data were retrospectively investigated from medical record. Patients showing atrial fibrillation on admission but unrecognized ever were defined as “incident AF”; patients with AF diagnosed before admission were defined as “prevalent AF”. Primary endpoint was a composite of death from cardiovascular disease or hospitalization for worsening heart failure. Secondary endpoints were death from cardiovascular disease, unplanned hospitalization related to heart failure, and any hospitalization.

Results

During mean follow up of 19 months, 139 patients (22%) were categorized as incident AF and 145 patients (23%) were categorized as prevalent AF. Among 239 patients showing AF on admission, 44 patients were discharged in SR (39 patients in incident AF and 5 patients in prevalent AF). Among incident AF patients, the primary composite end point occurred in significantly fewer in those who discharged in SR (19% vs. 42% at 1-year; 23% vs. 53% at 2-year follow-up, p=0.005). To compare the risk factors related to readmission due to HF with the cox proportional-hazards model, AF only during hospitalization [Hazard Ratio (HR)=0.37, p<0.01] and prevalent AF (HR=1.67, p=0.04) was significantly associated. There was no significant difference depending on LVEF.

Conclusion

Newly diagnosed AF with restoration to SR during hospitalization was a good marker to forecast future prognosis.

P6544A real world study of high frequency atrial anti-tachycardia pacing in new algorithm for atrial arrhythmia

Background

Advanced pacemakers feature atrial antitachycardia pacing (aATP) therapies for terminating atrial arrhythmia. Previous studies showed the efficacy of combined atrial preventive pacing and aATP in patients with pacemakers. The independent effect of aATP and the impact for patients outside the clinical trials has not been well elucidated.

Methods

In a single center, prospective, all-comers trial, we enrolled 567 patients implanted cardiac devices with Reactive ATP function. History of permanent atrial fibrillation (AF) was not included. After device interrogation of the AF burden and the longest AF duration in the last 6 months, aATP was programmed as a bit more aggressive setting than MINERVA trial (time interval was set as every 2 hours). As for newly implanted devices, aATP was activated after at least 3 months run-in period. Primary and secondary outcomes were the longest AF duration and cumulative percentage of progression into permanent AF, respectively.

Results

Of 541 eligible patients, aged 75.3±10.7 years, 356 pacemaker, 82 ICD and 103 CRT patients, the longest single episode of AF lasted ≤6 min in 439 patients (81.1%), >6 min to 6 h in 43 (8.0%), >6–24 h in 33 (6.1%), and >24 h in 26 (4.8%) at the enrollment. During mean follow-up of 1.9 years, the longest AF episode lasted >24 h in 49 patients (9.1%) and 14 patients (2.6%) progressed into permanent AF. According with baseline longest single episode of AF, patients with AF ≤6 min developed an episode >24 h in 0.8% at 1 year and 3.2% at 2 years follow up; patients with AF >6 min to 6 h developed an episode >24 h in none at 1 year and 7% at 2 years follow up; and patients with AF >6–24 h developed an episode >24 h in 19% at 1 year and 42% at 2 years follow up, respectively. In a subgroup analysis of in 192 patients with at least 1 aATP, 46 patients with high efficacy (>44%) did not developed an episode >24 h. Only one patient developed into permanent AF without aATP therapy. On multivariate analysis, neither ICD nor CRT was independent risk factor for developing the longest AF episode >24 h.

Conclusions

The independent use of aATP without atrial preventive pacing was effective for preventing AF progression in a real world cohort. Even without the previous AF episodes, aATP could prevent AF development, especially in patients showing high aATP efficacy. Future research is required to enhance the aATP success rate.

Systemic Immunologic Consequences of Chronic Periodontitis

Chronic periodontitis (ChP) is a prevalent inflammatory disease affecting 46% of the US population. ChP produces a profound local inflammatory response to dysbiotic oral microbiota that leads to destruction of alveolar bone and tooth loss. ChP is also associated with systemic illnesses, including cardiovascular diseases, malignancies, and adverse pregnancy outcomes. However, the mechanisms underlying these adverse health outcomes are poorly understood. In this prospective cohort study, we used a highly multiplex mass cytometry immunoassay to perform an in-depth analysis of the systemic consequences of ChP in patients before (n = 28) and after (n = 16) periodontal treatment. A high-dimensional analysis of intracellular signaling networks revealed immune system-wide dysfunctions differentiating patients with ChP from healthy controls. Notably, we observed exaggerated proinflammatory responses to Porphyromonas gingivalis-derived lipopolysaccharide in circulating neutrophils and monocytes from patients with ChP. Simultaneously, natural killer cell responses to inflammatory cytokines were attenuated. Importantly, the immune alterations associated with ChP were no longer detectable 3 wk after periodontal treatment. Our findings demarcate systemic and cell-specific immune dysfunctions in patients with ChP, which can be temporarily reversed by the local treatment of ChP. Future studies in larger cohorts are needed to test the boundaries of generalizability of our results.

Comparison of Different Parathyroid Hormone Radioimmunoassays in Uremic Patients with Secondary Hyperparathyroidism

Parathyroid hormone (PTH) levels of patients with chronic renal failure (CRF) were measured by three different radioimmunoassays (RIA); RIA for mid-region PTH by antibody CH9 (i-PTH) (1), RIA for intact fragments of PTH (intact PTH) and RIA for C-terminal fragments of PTH (PTH-C). PTH levels were higher in CRF patients undergoing hemodialysis therapy (hemodialysis patients) by all three methods. However, PTH levels measured only by i-PTH assay and intact PTH assay were significantly higher in patients with CRF who were not on dialysis (non-dialyzed CRF patients). PTH levels were above normal when creatinine clearance was below 45 ml/min in the intact PTH assay and 66 ml/min in the i-PTH assay. I-PTH levels were well correlated with the severity of osteitis fibrosa evaluated by the degree of periosteal resorption in the digits of hemodialysis patients. Since special handling of the sample is required for the intact PTH assay, i-PTH assay is the most suitable method for diagnosing secondary hyperparathyroidism in patients with CRF.

Heterogeneous fates and dynamic rearrangement of regenerative epidermis-derived cells during zebrafish fin regeneration

The regenerative epidermis (RE) is a specialized tissue that plays an essential role in tissue regeneration. However, the fate of the RE during and after regeneration is unknown. In this study, we performed Cre-loxP-mediated cell fate tracking and revealed the fates of major population of regenerative epidermis cells that express fibronectin 1b (fn1b) during zebrafish fin regeneration. Our study showed that these RE cells are mainly recruited from the inter-ray epidermis, and that they follow heterogeneous cell fates. Early recruited cells contribute to initial wound healing and soon disappear by apoptosis, while the later recruited cells contribute to the regenerated epidermis. Intriguingly, many of these cells were also expelled from the regenerated tissue by a dynamic caudal movement of the epidermis over time, and in turn the loss of epidermal cells was replenished by a global self-replication of basal and suprabasal cells in fin. De-differentiation of non-basal epidermal cells into the basal epidermal cells did not occur during regeneration. Overall, our study revealed heterogeneous fates of RE cells and a dynamic rearrangement of the epidermis during and after regeneration.

Osteoblast Production by Reserved Progenitor Cells in Zebrafish Bone Regeneration and Maintenance

Mammals cannot re-form heavily damaged bones as in large fracture gaps, whereas zebrafish efficiently regenerate bones even after amputation of appendages. However, the source of osteoblasts that mediate appendage regeneration is controversial. Several studies in zebrafish have shown that osteoblasts are generated by dedifferentiation of existing osteoblasts at injured sites, but other observations suggest that de novo production of osteoblasts also occurs. In this study, we found from cell-lineage tracing and ablation experiments that a group of cells reserved in niches serves as osteoblast progenitor cells (OPCs) and has a significant role in fin ray regeneration. Besides regeneration, OPCs also supply osteoblasts for normal bone maintenance. We further showed that OPCs are derived from embryonic somites, as is the case with embryonic osteoblasts, and are replenished from mesenchymal precursors in adult zebrafish. Our findings reveal that reserved progenitors are a significant and complementary source of osteoblasts for zebrafish bone regeneration.