Emergence and rapid transmission of SARS-CoV-2 B.1.1.7 in the United States.

The highly transmissible B.1.1.7 variant of SARS-CoV-2, first identified in the United Kingdom, has gained a foothold across the world. Using S gene target failure (SGTF) and SARS-CoV-2 genomic sequencing, we investigated the prevalence and dynamics of this variant in the United States (US), tracking it back to its early emergence. We found that, while the fraction of B.1.1.7 varied by state, the variant increased at a logistic rate with a roughly weekly doubling rate and an increased transmission of 40%-50%. We revealed several independent introductions of B.1.1.7 into the US as early as late November 2020, with community transmission spreading it to most states within months. We show that the US is on a similar trajectory as other countries where B.1.1.7 became dominant, requiring immediate and decisive action to minimize COVID-19 morbidity and mortality.

Exploiting transposons in the study of Staphylococcus aureus pathogenesis and virulence.

The opportunistic pathogen Staphylococcus aureus has an extremely complex relationship with humans. While the bacteria can exist as a commensal in many, it can cause a wide range of diseases and infections when turned pathogenic. Its presence is a determinant of chronicity and poor prognosis in numerous diseases, and its genomic plasticity causes S. aureus antimicrobial resistance to be one of the most dire contemporary medical problems to solve. Genetic manipulation of S. aureus has led to numerous findings that are vital in the fight against its pathogenesis. The utilisation of transposon mutant libraries for the systematic inspection of the S. aureus genome led to many landmark discoveries pertaining to the bacteria's pathogenicity, antimicrobial resistance acquisition, and virulence regulation. In this review, we describe mutant libraries, and their significant contributions, from various S. aureus strains created with commonly used transposons. The general workflow for the construction of libraries will be presented, along with a discussion of the challenges of undertaking the task of large-scale library construction. As the accessibility of transposon mutant library construction, screening, and analysis increases, this genetic tool could be further exploited in the study of the S. aureus genome.

Cx43 regulates mechanotransduction mechanisms in human preterm amniotic membrane defects.

OBJECTIVE: The effects of mechanical stimulation in preterm amniotic membrane (AM) defects were explored. METHODS: Preterm AM was collected from women undergoing planned preterm caesarean section (CS) due to fetal growth restriction or emergency CS after spontaneous preterm prelabour rupture of the membranes (sPPROM). AM explants near the cervix or placenta were subjected to trauma and/or mechanical stimulation with the Cx43 antisense. Markers for nuclear morphology (DAPI), myofibroblasts (αSMA), migration (Cx43), inflammation (PGE2 ) and repair (collagen, elastin and transforming growth factor ß [TGFß1 ]) were examined by confocal microscopy, second harmonic generation, qPCR and biochemical assays. RESULTS: In preterm AM defects, myofibroblast nuclei were highly deformed and contractile and expressed αSMA and Cx43. Mechanical stimulation increased collagen fibre polarisation and the effects on matrix markers were dependent on tissue region, disease state, gestational age and the number of fetuses. PGE2 levels were broadly similar but reduced after co-treatment with Cx43 antisense in late sPPROM AM defects. TGFß1 and Cx43 gene expression were significantly increased after trauma and mechanical stimulation but this response dependent on gestational age. CONCLUSION: Mechanical stimulation affects Cx43 signalling and cell/collagen mechanics in preterm AM defects. Establishing how Cx43 regulates mechanosignalling could be an approach to repair tissue integrity after trauma.

Short and mid-term characteristics of COVID-19 disease course in athletes: A high-volume, single-center study.

INTRODUCTION: At the pandemic's beginning, significant concern has risen about the prevalence of myocardial involvement after SARS-CoV-2 infection. We assessed the cardiovascular burden of SARS-CoV-2 in a large cohort of athletes and identified factors that might affect the disease course. We included 633 athletes in our study on whom we performed extensive cardiology examinations after recovering from SARS-CoV-2 infection. More than half of the athletes (n = 322) returned for a follow-up examination median of 107 days after the commencement of their infection. RESULTS: Troponin T positivity was as low as 1.4% of the athletes, where the subsequently performed examinations did not show definitive, ongoing myocardial injury. Altogether, 31% of the athletes' rapid training rebuild was hindered by persistent or reoccurring symptoms. Female athletes reported a higher prevalence of return to play (RTP) symptoms than their male counterparts (34% vs. 19%, p = 0.005). The development of long COVID symptoms was independently predicted by increasing age and acute symptoms' severity in a multiple regression model (AUC 0.75, CI 0.685-0.801). Athletes presenting with either or both cough and ferritin levels higher than >150 µg/L had a 4.1x (CI 1.78-9.6, p = 0.001) higher odds ratio of developing persistent symptoms. CONCLUSION: While SARS-CoV-2 rarely affects the myocardium in athletes, about one in three of them experience symptoms beyond the acute phase. Identifying those athletes with a predisposition to developing long-standing symptoms may aid clinicians and trainers in finding the optimal return-to-play timing and training load rebuild pace.

A Method for Variant Agnostic Detection of SARS-CoV-2, Rapid Monitoring of Circulating Variants, and Early Detection of Emergent Variants Such as Omicron.

The rapid emergence of SARS-CoV-2 variants raised public health questions concerning the capability of diagnostic tests to detect new strains, the efficacy of vaccines, and how to map the geographical distribution of variants to understand transmission patterns and loads on healthcare resources. Next-generation sequencing (NGS) is the primary method for detecting and tracing new variants, but it is expensive, and it can take weeks before sequence data are available in public repositories. This article describes a customizable reverse transcription PCR (RT-PCR)-based genotyping approach which is significantly less expensive, accelerates reporting, and can be implemented in any lab that performs RT-PCR. Specific single-nucleotide polymorphisms (SNPs) and indels were identified which had high positive-percent agreement (PPA) and negative-percent agreement (NPA) compared to NGS for the major genotypes that circulated through September 11, 2021. Using a 48-marker panel, testing on 1,031 retrospective SARS-CoV-2 positive samples yielded a PPA and NPA ranging from 96.3 to 100% and 99.2 to 100%, respectively, for the top 10 most prevalent World Health Organization (WHO) lineages during that time. The effect of reducing the quantity of panel markers was explored, and a 16-marker panel was determined to be nearly as effective as the 48-marker panel at lineage assignment. Responding to the emergence of Omicron, a genotyping panel was developed which distinguishes Delta and Omicron using four highly specific SNPs. The results demonstrate the utility of the condensed panel to rapidly track the growing prevalence of Omicron across the US in December 2021 and January 2022.

Patient-specific Alzheimer-like pathology in trisomy 21 cerebral organoids reveals BACE2 as a gene dose-sensitive AD suppressor in human brain.

A population of more than six million people worldwide at high risk of Alzheimer's disease (AD) are those with Down Syndrome (DS, caused by trisomy 21 (T21)), 70% of whom develop dementia during lifetime, caused by an extra copy of ß-amyloid-(Aß)-precursor-protein gene. We report AD-like pathology in cerebral organoids grown in vitro from non-invasively sampled strands of hair from 71% of DS donors. The pathology consisted of extracellular diffuse and fibrillar Aß deposits, hyperphosphorylated/pathologically conformed Tau, and premature neuronal loss. Presence/absence of AD-like pathology was donor-specific (reproducible between individual organoids/iPSC lines/experiments). Pathology could be triggered in pathology-negative T21 organoids by CRISPR/Cas9-mediated elimination of the third copy of chromosome 21 gene BACE2, but prevented by combined chemical ß and γ-secretase inhibition. We found that T21 organoids secrete increased proportions of Aß-preventing (Aß1-19) and Aß-degradation products (Aß1-20 and Aß1-34). We show these profiles mirror in cerebrospinal fluid of people with DS. We demonstrate that this protective mechanism is mediated by BACE2-trisomy and cross-inhibited by clinically trialled BACE1 inhibitors. Combined, our data prove the physiological role of BACE2 as a dose-sensitive AD-suppressor gene, potentially explaining the dementia delay in ~30% of people with DS. We also show that DS cerebral organoids could be explored as pre-morbid AD-risk population detector and a system for hypothesis-free drug screens as well as identification of natural suppressor genes for neurodegenerative diseases.

Development of a refined ex vivo model of peritoneal adhesion formation, and a role for connexin 43 in their development.

Despite many advances across the surgical sciences, post-surgical peritoneal adhesions still pose a considerable risk in modern-day procedures and are highly undesirable. We have developed a novel mouse peritoneal strip ex vivo adhesion model which may serve to bridge the gap between single cell culture systems and in vivo animal drug testing for the assessment of potential anti-adhesion agents, and study of causality of the process. We investigated the optimal conditions for adhesion formation with mouse peritoneal tissue strips by modifying an existing ex vivo rat model of peritoneal adhesions. We assessed the impact of the following conditions on the formation of adhesions: contact pressure, abrasions, and the presence of clotted blood. Macroscopic adhesions were detected in all mouse peritoneal strips exposed to specific conditions, namely abrasions and clotted blood, where peritoneal surfaces were kept in contact with pressure using cotton gauze in a tissue cassette. Adhesions were confirmed microscopically. Interestingly, connexin 43, a gap junction protein, was found to be upregulated at sites of adhesions. Key features of this model were the use of padding the abraded tissue with gauze and the use of a standardised volume of clotted blood. Using this model, peritoneal strips cultured with clotted blood between abraded surfaces were found to reproducibly develop adhesion bands at 72 h. Our goal is to develop a model that can be used in genetically modified mice in order to dissect out the role of particular genes in adhesion formation and to test drugs to prevent adhesion formation.

Characteristics and outcomes associated with two asthma quality of care measures.

OBJECTIVE: We investigated asthma quality measures to understand patient characteristics associated with non-attainment of quality care and measure the association with asthma-related emergency department (ED) visits or inpatient hospitalizations (IPs). METHODS: Using administrative data from ALL Kids, Alabama's Children's Health Insurance Program, from 2013 to 2019 we calculated non-attainment of the Medication Management for Asthma (MMA) and Asthma Medication Ratio (AMR) quality measures. Patient characteristics and asthma-related ED visits and IPs associated with non-attainment of the MMA and AMR measures were assessed using logit regression models and Marginal effects at the mean. RESULTS: Among 2528 children with asthma, 53.2% failed to attain the MMA measure and 8.5% the AMR measure. Prior asthma-related ED visits or IP stays increased likelihood of non-attainment by 14.8 percentage points (95% CI 8.6-20.9) for MMA and 7.3 percentage points (95% CI 2.8-11.8) for AMR. Among 868 children (34.3%) with three years of continuous enrollment, AMR non-attainment was associated with a 6.1 percentage point increase in ED or IP utilization (95% CI 1.3-10.9), however MMA non-attainment was not associated with either outcome. Prior ED visit/IP stay was associated with a 17.2 percentage point (95% CI 8.3-26.1) increase in the likelihood of a subsequent ED visit/IP stay among those with non-attainment MMA and a 15.5 percentage point increase (95% CI 6.9-24.2) for non-attainment AMR. CONCLUSIONS: Patient characteristics associated with non-attainment of asthma quality measures presents actionable evidence to guide improvement efforts as non-attainment AMR increases the risk of subsequent ED visits and IP stays.

Is cardiac involvement prevalent in highly trained athletes after SARS-CoV-2 infection? A cardiac magnetic resonance study using sex-matched and age-matched controls.

OBJECTIVES: To investigate the cardiovascular consequences of SARS-CoV-2 infection in highly trained, otherwise healthy athletes using cardiac magnetic resonance (CMR) imaging and to compare our results with sex-matched and age-matched athletes and less active controls. METHODS: SARS-CoV-2 infection was diagnosed by PCR on swab tests or serum immunoglobulin G antibody tests prior to a comprehensive CMR examination. The CMR protocol contained sequences to assess structural, functional and tissue-specific data. RESULTS: One hundred forty-seven athletes (94 male, median 23, IQR 20-28 years) after SARS-CoV-2 infection were included. Overall, 4.7% (n=7) of the athletes had alterations in their CMR as follows: late gadolinium enhancement (LGE) showing a non-ischaemic pattern with or without T2 elevation (n=3), slightly elevated native T1 values with or without elevated T2 values without pathological LGE (n=3) and pericardial involvement (n=1). Only two (1.4%) athletes presented with definite signs of myocarditis. We found pronounced sport adaptation in both athletes after SARS-CoV-2 infection and athlete controls. There was no difference between CMR parameters, including native T1 and T2 mapping, between athletes after SARS-CoV-2 infection and the matched athletic groups. Comparing athletes with different symptom severities showed that athletes with moderate symptoms had slightly greater T1 values than athletes with asymptomatic and mildly symptomatic infections (p<0.05). However, T1 mapping values remained below the cut-off point for most patients. CONCLUSION: Among 147 highly trained athletes after SARS-CoV-2 infection, cardiac involvement on CMR showed a modest frequency (4.7%), with definite signs of myocarditis present in only 1.4%. Comparing athletes after SARS-CoV-2 infection and healthy sex-matched and age-matched athletes showed no difference between CMR parameters, including native T1 and T2 values.

Outcomes before and after Adopting Guidelines for Expectant Management of Severe Preeclampsia.

OBJECTIVE: This study aimed to compare maternal and neonatal outcomes in women with severe preeclampsia before and after implementation of the American College of Obstetricians and Gynecologists (ACOG) taskforce hypertensive guidelines. STUDY DESIGN: Single-center retrospective cohort study of women with severe preeclampsia delivering live nonanomalous singletons 23 to 342/7 weeks from 2013 to 2017. In 2015, the ACOG guidelines for expectant management of severe preeclampsia were implemented at our institution. Based on this, patients were categorized as preguideline (January 2013-December 2015) or postguideline adoption (January 2016-December 2017). Primary outcomes included composite maternal morbidity and composite neonatal morbidity; secondary outcomes included composite components, length of stay, birth weight, and delivery gestational age. Groups were compared with Student's t-test, Chi-square, and Wilcoxon's rank-sum tests; adjusted odds ratios (aOR; 95% confidence intervals [CIs]) were calculated. Yearly composite outcomes were compared using the Cochran-Armitage trend test. We estimated a sample size of 250 per group would provide 80% power at α = 0.05 to detect a 50% reduction in neonatal morbidity from a baseline rate of 21.5%. RESULTS: From 2013 to 2017, a total of 543 women with severe preeclampsia were identified: 278 (51%) preguideline and 265 (49%) postguideline. Baseline characteristics were overall similar between groups. There were no significant differences in maternal (aOR = 0.96, 95% CI: 0.6-1.41) or neonatal (aOR = 0.88, 95% CI: 0.61-1.28) composite morbidity between groups. Furthermore, there were no differences in composite maternal or neonatal morbidity over time. CONCLUSION: Perinatal outcomes were similar before and after implementation of severe preeclampsia management guidelines at our institution. Studies to evaluate if benefits are limited to subsets of this population, such as earlier gestational ages, are needed. KEY POINTS: · Expectant management of severe preeclampsia has yet to be fully evaluated outside of trial conditions.. · We did not see a significant improvement in neonatal composite morbidity/mortality.. · We also did not see a worsened composite maternal morbidity/mortality..

Contemporary Test Performance of the Random Urine Protein-to-creatinine Ratio.

OBJECTIVE: The random urine protein-to-creatinine ratio (UPCR) is a screening test used for predicting clinically significant proteinuria (urine protein ≥ 300 mg) during pregnancy. No consensus exists on the optimal random UPCR cutoff for performing follow-up 24 hour urine (24H) total protein collection. We aim to evaluate the test performance of random UPCR in predicting proteinuria in a contemporary cohort. STUDY DESIGN: This was a retrospective cohort study of pregnant patients at our institution from 2014 to 2018 with a random UPCR and follow-up 24H protein collection. The primary analysis estimated the test characteristics (sensitivity, specificity, positive and negative predictive values) of using random UPCR for the detection of proteinuria defined as urine protein ≥300 mg on 24H protein collection. UPCR cutoffs from 0.10 to 0.30 mg/dL were evaluated, receiver operator characteristic (ROC) curve was constructed, and area under the curve (AUC) was determined. A secondary analysis examined the correlation between UPCR and 24H protein using least squares regression and Pearson correlation. RESULTS: Paired UPCR and 24H collection results were available for 1,120 patients. Mean gestational age at time of UPCR was 31.1 ± 5.1 weeks and 687 (61.3%) of patients had a 24H ≥300 mg. UPCR <0.10 mg/dL effectively excluded proteinuria ≥300 mg on 24H collection, while UPCR ≥0.18 mg/dL correctly classifies proteinuria with 91% sensitivity, 57% specificity, 77% positive predictive value, and 79% negative predictive value. UPCR ≥1.07 mg/dL had 100% specificity for 24 hour proteinuria. The area under ROC curve was 0.86. UPCR and 24H collection were highly correlated with a Pearson correlation coefficient of 0.85. After our institution lowered the threshold to obtain a 24H from UPCR ≥0.20 mg/dL to ≥0.10 mg/dL in May 2017, the percentage of patients meeting criteria for 24H collection increased from 57.8 to 84.4%. CONCLUSION: The AUC and Pearson correlation suggest random UPCR is a high performance test for the prediction of proteinuria on 24H. Optimal test performance is dependent upon clinical consideration and upon the implications of the disease or condition. A random UPCR screen positive threshold of 0.18 mg/dL maximizes sensitivity to identify clinically significant proteinuria. KEY POINTS: · Random urine protein to creatinine ratio is a high performance test for proteinuria.. · A random UPCR threshold of 0.18 mg/dL maximizes sensitivity to identify proteinuria.. · Optimal test performance is dependent on the disease or clinical condition..

Reperfusion therapies and in-hospital outcomes for ST-elevation myocardial infarction in Europe: the ACVC-EAPCI EORP STEMI Registry of the European Society of Cardiology.

AIMS: The aim of this study was to determine the contemporary use of reperfusion therapy in the European Society of Cardiology (ESC) member and affiliated countries and adherence to ESC clinical practice guidelines in patients with ST-elevation myocardial infarction (STEMI). METHODS AND RESULTS: Prospective cohort (EURObservational Research Programme STEMI Registry) of hospitalized STEMI patients with symptom onset <24 h in 196 centres across 29 countries. A total of 11 462 patients were enrolled, for whom primary percutaneous coronary intervention (PCI) (total cohort frequency: 72.2%, country frequency range 0-100%), fibrinolysis (18.8%; 0-100%), and no reperfusion therapy (9.0%; 0-75%) were performed. Corresponding in-hospital mortality rates from any cause were 3.1%, 4.4%, and 14.1% and overall mortality was 4.4% (country range 2.5-5.9%). Achievement of quality indicators for reperfusion was reported for 92.7% (region range 84.8-97.5%) for the performance of reperfusion therapy of all patients with STEMI <12 h and 54.4% (region range 37.1-70.1%) for timely reperfusion. CONCLUSIONS: The use of reperfusion therapy for STEMI in the ESC member and affiliated countries was high. Primary PCI was the most frequently used treatment and associated total in-hospital mortality was below 5%. However, there was geographic variation in the use of primary PCI, which was associated with differences in in-hospital mortality.

Conservation psychology and the legacy of Carol Saunders for zoo and aquarium programs, networks, practices, and exhibits.

Conservation Psychology created a dialog between environmental conservation and behavioral sciences. With an outsized influence by Dr. Carol Saunders, it started at Brookfield Zoo in Chicago exploring questions about the impacts of a zoo visit, and particularly how human behavior influences environmental outcomes for our planet. Here we explore how Conservation Psychology influenced the development of programs, exhibits and communities of practice at Brookfield Zoo and elsewhere in the zoo and aquarium world, and how eventually these applications changed the way modern zoos and aquariums operate. We present testimonials and review a handful of examples in which Conservation Psychology led to tangible programs, practices and wide professional networks at zoos and aquariums. These include an exploration of the future of zoos with George Rabb, followed by the legacy of nature play and the groundbreaking Hamill Family Play Zoo. Furthermore, we discuss how visitor studies at zoos and aquariums were influenced by Conservation Psychology, including the development of the Association of Zoos and Aquariums Social Science Research and Evaluation Scientific Advisory Group and two climate change education networks. We end with the development of tools, practices, and professional networks to explore empathy for animals. Most of these programs were envisioned or facilitated by Dr. Saunders, who was always a role model with an impact and a legacy that lives on.

Toward integrated synchronously pumped optical parametric oscillators in silicon nitride.

We present a tunable, hybrid waveguide-fiber optical parametric oscillator (OPO) synchronously pumped by an ultra-fast fiber laser exploiting four-wave mixing (FWM) generated in silicon nitride waveguides. Parametric oscillation results in a 35 dB enhancement of the idler spectral power density in comparison to spontaneous FWM, with the ability of wide wavelength tuning over 86 nm in the O-band. Measurements of the oscillation threshold and the efficiency of the feedback loop reveal how an integration of the OPO on a single silicon nitride chip can be accomplished at standard repetition rates of pump lasers in the order of 100 MHz.

Needle in the heart: a rare case of cardiac tamponade caused by a migrated foreign body and mimicking ST segment elevation myocardial infarction.

BACKGROUND: Pericardial tamponade is a serious condition which may eventually lead to severe haemodynamic disturbances and cardiac arrest. It is most often caused by the accumulation of fluid inside the pericardium, as a result of different aetiological factors such as pericarditis, neoplastic diseases, lymphatic dysfunctions, or idiopathic pericardial disease. Pericardial tamponade can develop after cardiac surgical procedures or as a complication of myocardial infarction. Collection of blood inside the pericardial sack can be the result of pericardial or cardiac trauma. It is exceedingly rare for the injury to be caused by a migrating foreign body. Although a typical picture of pericardial tamponade has been previously described, the disorder may clinically resemble an acute myocardial infarction. CASE PRESENTATION: We report the case of a 58-year-old female patient complaining of new onset thoracic pain and shortness of breath. Electrocardiographic examination results were suggestive of an acute inferior myocardial infarction. However, echocardiography revealed significant pericardial tamponade. The cause was found to be a needle which remained inside the pelvis following a previous cesarean delivery, which the patient had undergone 18 years prior. In emergency setting, the needle was removed and the pericardial tamponade was resolved. Due to the prompt and efficient management, the patient had an uneventful postoperative recovery and presented no recurrence at the follow-up examinations. CONCLUSIONS: The migration of foreign bodies through tissues is exceedingly rare. If present, it may cause life-threatening complications. Since the aetiology of pericardial tamponade is vast, a thorough assessment is highly important. Therefore, echocardiography is the imaging modality of choice. We wish to highlight the possibility of migrating foreign bodies as probable cause for pericardial tamponade, as well as the importance of echocardiographic methods in the fast-track evaluation of such critical conditions.

Potential sealing and repair of human FM defects after trauma with peptide amphiphiles and Cx43 antisense.

OBJECTIVE: We examined whether peptide amphiphiles functionalised with adhesive, migratory or regenerative sequences could be combined with amniotic fluid (AF) to form plugs that repair fetal membrane (FM) defects after trauma and co-culture with connexin 43 (Cx43) antisense. METHODS: We assessed interactions between peptide amphiphiles and AF and examined the plugs in FM defects after trauma and co-culture with the Cx43antisense. RESULTS: Confocal microscopy confirmed directed self-assembly of peptide amphiphiles with AF to form a plug within minutes, with good mechanical properties. SEM of the plug revealed a multi-layered, nanofibrous network that sealed the FM defect after trauma. Co-culture of the FM defect with Cx43 antisense and plug increased collagen levels but reduced GAG. Culture of the FM defect with peptide amphiphiles incorporating regenerative sequences for 5 days, increased F-actin and nuclear cell contraction, migration and polarization of collagen fibers across the FM defect when compared to control specimens with minimal repair. CONCLUSIONS: Whilst the nanoarchitecture revealed promising conditions to seal iatrogenic FM defects, the peptide amphiphiles need to be designed to maximize repair mechanisms and promote structural compliance with high mechanical tolerance that maintains tissue remodeling with Cx43 antisense for future treatment.

Mid-Trimester Cervical Length Screening: Effect of Poorly Developed Lower Uterine Segment on Pregnancy Outcome.

OBJECTIVES: To identify whether a poorly developed lower uterine segment (PDLUS) observed during cervical length (CL) screening affects the duration of gestation in women with no prior spontaneous preterm birth (sPTB). MATERIALS AND METHODS: A retrospective cohort study of women with a singleton gestation and no prior sPTB, who underwent transvaginal CL screening at our institution. We excluded women with progesterone exposure, major anomalies, and women delivering elsewhere. Women with PDLUS were compared to those with a measured (normal) CL ≥25 mm. PRIMARY OUTCOME: birth gestational age (GA). SECONDARY OUTCOMES: sPTB <35 and 37 weeks, hospital evaluation for preterm labor without delivery, delivery indication, and mode. A Cox proportional-hazards survival model considered time from CL scan to delivery. We powered the study to detect a one-half week difference in birth GA. RESULTS: We included 270 women with PDLUS and 985 women with normal CL. Mean birth GA was 38.9 ± 2.0 weeks with PDLUS versus 38.7 ± 2.4 weeks with normal CL (p = .10). Women with PDLUS were less likely to experience sPTB <37 weeks (1.1% vs 3.6%; p = 0.04). There was no difference in sPTB <35 weeks (0.8% vs 1.7%; p = .25). Hospital evaluation for preterm labor (17% vs 19%; p = .54), delivery indication, and mode were not different. The hazard ratio for earlier birth in women with PDLUS was 0.67 (95% CI 0.46, 0.98; p = .04). CONCLUSIONS: We observed no difference in mean GA at birth; however, PDLUS was protective against sPTB <37 weeks and was associated with a lower hazard ratio for earlier birth.

Pulpal upregulation of connexin 43 during pulpitis.

OBJECTIVES: Connexins are building blocks of membranous channels that form gap junctions and hemichannels. These channels are essential portals for information exchange and coordination during inflammation. Pathologic levels of these conduits may result in excessive inflammation and collateral destruction. This study aimed to analyse temporospatial levels of connexin 43 (Cx43) during pulpitis in extracted human teeth and in a rodent model. A specific interest was directed at the pulpal stroma as it is conserved during vital pulp therapy. MATERIALS AND METHODS: Pulpal tissues were attained from human extracted teeth of various pulpal inflammatory stages and fixed for cryosections. Pulpal exposures were created in bilateral maxillary molars in Sprague-Dawley rats. Rats were sacrificed at days 1 to 5 post-exposure. Immunofluorescence histology was performed to detect Cx43, markers for inflammation, and cell death. Immunofluorescent levels in the pulpal stroma at 3 sites (wound/near/far) were matched to pulpal condition (human) or days post-exposure (rodent). RESULTS: Cx43 upregulation was observed with increased severity of pulpitis both in humans and rodent model. The upregulation appeared to be global and included distant regions. Elevated levels of neutrophils were present in advanced pulpitis. Apoptosis and necroptosis seem to be upregulated in human samples as Cx43 levels rose. CONCLUSIONS: We observed a disseminated upregulation of Cx43 throughout the pulpal stroma as inflammation became advanced. This observation may facilitate cell death signal transfer or represent overt levels of purinergic signalling that leads to pro-inflammatory conditions. CLINICAL RELEVANCE: Cx43 downregulation may represent a potential therapeutic approach to enable resolution of pulpal inflammation.

Characterisation of an ischemia reperfusion model for the formation of a stage I pressure ulcer in mouse skin.

Pairs of magnets were applied to the loose skin on the backs of mice in order to cause ischemia for periods of 1.5, 2, 2.5 and 3 h followed by reperfusion. We found 1.5 h of ischemia resulted in the most reliable outcome of blanched skin but no redness or skin breakdown. Histological analysis at 4 h of reperfusion showed, in the centre of the insult, condensed nuclei in the epidermis and sebaceous glands with a build up of neutrophils in the blood vessels, and a reduction in the number of fibroblasts. At 24 h, spongiosis was seen in the epidermis and pockets of neutrophils began to accumulate under it, as well as being scatted through the dermis. In the centre of the insult there was a loss of sebaceous gland nuclei and fibroblasts. Four days after the insult, spongiosis was reduced in the epidermis at the edge of the insult but enhanced in the centre and in hair follicles. Leukocytes were seen throughout the central dermis. At 8 days, spongiosis and epidermal thickness had reduced and fibroblasts were reappearing. However, blood vessels still had leukocytes lining the lumen. The gap junction protein connexin 43 was significantly elevated in the epidermis at 4 h and 24 h reperfusion. Ischemia of 1.5 h generates a sterile inflammatory reaction causing the loss of some cell types but leaving the epidermis intact reminiscent of a stage I pressure ulcer.

Epidermal graft encourages wound healing by down-regulation of gap junctional protein and activation of wound bed without graft integration as opposed to split-thickness skin graft.

Wound coverage by split-thickness skin graft (SSG) and epidermal graft (EG) shortens healing time, with comparable outcomes. However, the healing mechanism of EG is not as well understood as SSG. The difference in the healing mechanisms of EG and SSG was investigated using gap junctional proteins, proliferative marker, and cytokeratin markers. Paired punch biopsies were taken from the wound edge and wound bed from patients undergoing EG and SSG at weeks 0 and 1 to investigate wound edge keratinocyte migratory activities (connexins 43, 30, and 26), wound bed activation (Ki67), and the presence of graft integration to the wound bed (cytokeratins 14 and 6). Twenty-four paired biopsies were taken at weeks 0 and 1 (EG, n = 12; SSG, n = 12). Wound edge biopsies demonstrated down-regulation of connexins 43 (P = .023) and 30 (P = .027) after EG, indicating accelerated healing from the wound edge. At week 1, increased expression of Ki67 (P < .05) was seen after EG, indicating activation of cells within the wound bed. Keratinocytes expressing cytokeratins 6 and 14 were observed on all wounds treated with SSG but were absent at week 1 after EG, indicating the absence of graft integration following EG. Despite EG and SSG both being autologous skin grafts, they demonstrate different mechanisms of wound healing. EG accelerates wound healing from the wound edges and activates the wound bed despite not integrating into the wound bed at week 1 post-grafting as opposed to SSG, hence demonstrating properties comparable with a bioactive dressing instead of a skin substitute.