Persistent Defects Research Articles

A zebrafish FASD model for congenital heart defects

Mothers who drink during pregnancy expose their developing babies to ethanol, and excessive drinking often produces devastating birth defects collectively termed fetal alcohol spectrum disorder (FASD). These defects include craniofacial defects, cognitive impairment, sensorimotor disabilities and organ deformities, including various congenital heart defects (CHDs), particularly septal and conotruncal defects. Genesis mechanisms for FASD‐associated CHDs are not well understood. Using a zebrafish model, experiments tested whether alcohol interferes with different heart development events or the multiple cardiac precursors that may contribute to CHD genesis. These experiments showed that ethanol affects various cardiac regulatory networks in multiple steps of cardiogenesis (specification, myocardial migration, differentiation, looping, chamber morphogenesis, and endocardial cushion formation). Retinoic acid and folic acid co‐treatment with ethanol had differential rescue effects on FASD‐induced cardiac defects. Early (first heart field) and late‐added (second heart field and cardiac neural crest precursors) cardiac precursors were reduced by ethanol exposure. Experiments showed dysregulation of BMP, Notch and other signaling pathways during atrioventricular valve formation produced persistent valve defects. Together, these results show that embryonic ethanol exposure disrupts critical cardiac morphogenic events and reduce cardiac precursor contributions to the growing heart. Additional mechanistic studies are needed to identify key events that can be targeted therapeutically.Support or Funding InformationNIH/NIAAA AA0022396 and AA026711This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Therapeutic Proteins for Treatment of Corneal Epithelial Defects.

Corneal epithelial disorders take pride of place in modern ophthalmology. Defects of corneal epithelium are commonly accompanied by blurry vision, photophobia and tearing. Since cornea is the most densely innervated tissue of organisms, its disruption leads to development of a severe pain syndrome. Mild corneal erosions commonly undergo quick spontaneous recovery. Suppression of corneal wound healing due to various pathological causes results in development of severe recurrent erosions and persistent corneal defects. These pathological events can in turn lead to corneal scarring, opacification, and ulceration of cornea, and ultimately to the permanent vision impairment. The etiology of the underlying corneal diseases that commonly involves inflammatory, neurotrophic and systemic factors, should be considered for treating such defects. Therefore, the research focus has been shifted to establish therapeutics based on proteins and peptides. Due to varied mechanisms of action, proteinbased pharmaceuticals can be involved in the protection of corneal surface, mimicking tear components, stimulation of corneal wound healing, regeneration of corneal innervation, suppressing oxidative stress, inflammation and neovascularization. The active components can be naturally occurring (blood- or tear-derived) or be created de novo and optimized in order to achieve the level of activity required. Such pharmaceuticals are characterized by low toxicity and absence of systemic side-effects due to their low absorption into the bloodstream, if administrated topically. This review summarizes existing data on protein-based drugs for treatment of corneal epithelial defects that are currently under preclinical development or testing in clinical trials, or approved for medical use.

Threshold Retinopathy of Prematurity with Persistent Corneal Defect

Aim: A case which highlights the challenges faced in treating a case of type 1 early treatment of retinopathy of prematurity (ETROP) with persistent corneal defect. Case Report: We report a case of a preterm boy born at 28 weeks with birth weight of 700 g who presented with persistent corneal defect along with type 1 ETROP disease. Because of the inability to complete LASER, intravitreal ranibizumab was given as a rescue therapy to buy some time. But unfortunately, baby succumbed to disease because of associated systemic problems. Conclusion: ROP can present with persistent corneal defect which can challenge the treatment of underlying pathology.

Single Cell Profiling Reveals PTEN Overexpression in Influenza-Specific B cells in Aging HIV-infected individuals on Anti-retroviral Therapy

Memory B cells (MBC) respond to secondary antigen challenge to protect against infection and to boost immunity following vaccinations. Despite effective treatment, chronic HIV infection disturbs MBCs by reducing numbers and altering functionality due to hyper-activation and increased apoptosis leading to suboptimal antibody responses against common infectious agents. We used single cell gene expression analysis to evaluate antigen-specific memory B cells in peripheral blood of virally-suppressed HIV-infected individuals and healthy controls stratified by serum H1N1 antibody response 3 weeks post-administration of the seasonal trivalent inactivated influenza vaccine. We used a fluorescent probe to isolate influenza H1N1-specific B cells and a multiplexed and targeted RT-PCR approach to measure expression levels of 96 genes involved in B cell activation and function. Gene profiling revealed a 4-gene predictive signature containing the phosphoinositide-3 kinase (PI3K) inhibitor, PTEN, for identifying antigen-specific MBC from HIV-infected individuals compared to healthy controls. Gene co-expression analysis showed that in addition to overexpression of PTEN, there was increased co-expression of type I interferon-associated genes with PTEN on single cell level in HIV compared to controls. This study highlights the persistent defects in MBC from HIV-infected individuals and points to the PI3K signaling pathway as a target for potential immune intervention.

Mucosal cell populations may contribute to peripheral immune abnormalities in HIV-infected subjects introducing cART with moderate immune-suppression.

HIV infection causes the progressive depletion of CD4+ T-lymphocytes and profound modifications of T-cell homeostasis, which persist despite virologically-suppressive treatment and have been linked to a worse clinical outcome. Enduring alterations of the gastrointestinal tract may represent the underlying pathogenic mechanisms of these phenomena. Twenty-six HIV-infected subjects were assessed over a 12-month period following the introduction of antiretroviral therapy. 18 uninfected individuals were enrolled as controls. Parameters of peripheral T-cell homeostasis (activation, maturation), gastrointestinal function (microbial translocation, gut inflammation, fecal microbiota composition) and mucosal immunity (CD4+CCR6+CD161+, CD4+CCR9+α4β7+, stem cell memory CD4+/CD8+ T-cells) were assessed. CD4+CCR6+CD161+ cells were depleted in HIV-infected untreated subjects and maintained significantly lower levels compared to controls, despite the introduction of effective antiviral treatment. The frequency of gut-homing CD4+CCR9+α4β7+ cells was also impaired in untreated infection and correlated with the HIV RNA load and CD4+HLADR+CD38+; during therapy, we observed a contraction of this pool in the peripheral blood and the loss of its correlation with antigenic exposure/immune activation. A partial correction of the balance between stem cell memory pools and T-cell homeostasis was registered following treatment. In HIV-infected subjects with moderate immune-suppression, antiretroviral therapy has a marginal impact on mucosal immune populations which feature distinctive kinetics in the periphery, possibly reflecting their diverse recruitment from the blood to the mucosa. The persistent defects in mucosal immunity may fuel peripheral T-cell abnormalities through diverse mechanisms, including the production of IL-17/IL-22, cellular permissiveness to infection and regulation of T-lymphocyte maturation.

The Role of Maternal Thyroid Hormones in Avian Embryonic Development

During avian embryonic development, thyroid hormones (THs) coordinate the expression of a multitude of genes thereby ensuring that the correct sequence of cell proliferation, differentiation and maturation is followed in each tissue and organ. Although THs are needed from the start of development, the embryonic thyroid gland only matures around mid-incubation in precocial birds and around hatching in altricial species. Therefore, maternal THs deposited in the egg yolk play an essential role in embryonic development. They are taken up by the embryo throughout its development, from the first day till hatching, and expression of TH regulators such as distributor proteins, transporters, and deiodinases in the yolk sac membrane provide the tools for selective metabolism and transport starting from this level. TH receptors and regulators of local TH availability are expressed in avian embryos in a dynamic and tissue/cell-specific pattern from the first stages studied, as shown in detail in chicken. Maternal hyperthyroidism via TH supplementation as well as injection of THs into the egg yolk increase TH content in embryonic tissues while induction of maternal hypothyroidism by goitrogen treatment results in a decrease. Both increase and decrease of maternal TH availability were shown to alter gene expression in early chicken embryos. Knockdown of the specific TH transporter monocarboxylate transporter 8 at early stages in chicken cerebellum, optic tectum, or retina allowed to reduce local TH availability, interfering with gene expression and confirming that development of the central nervous system (CNS) is highly dependent on maternal THs. While some of the effects on cell proliferation, migration and differentiation seem to be transient, others result in persistent defects in CNS structure. In addition, a number of studies in both precocial and altricial birds showed that injection of THs into the yolk at the start of incubation influences a number of parameters in posthatch performance and fitness. In conclusion, the data presently available clearly indicate that maternal THs play an important role in avian embryonic development, but how exactly their influence on cellular and molecular processes in the embryo is linked to posthatch fitness needs to be further explored.

Ceramic Bone Graft Substitutes do not reduce donor-site morbidity in ACL reconstruction surgeries: a pilot study.

Introduction: Anterior knee pain is a major problem following Bone-patellar-tendon-bone graft (BPTB) use in anterior cruciate ligament (ACL) reconstruction. We hypothesized that filling the donor defect sites with bone-graft substitute would reduce the anterior knee symptoms in ACL reconstruction surgeries. Material and Methods: Patients operated for ACL-deficient knee between March 2012 and August 2013 using BPTB graft were divided into two treatment groups. The patellar and tibial donor-site bony defects were filled-up with Hydroxyapatite–Bioglass (HAP:BG) blocks in the study group (n = 15) and no filler was used in the control group (n = 16). At 2 years, the clinical improvement was assessed using International Knee Documentation Committee (IKDC) score and donor-site morbidity was assessed by questionnaires and specific tests related to anterior knee pain symptoms. Results: Donor-site tenderness was present in 40% patients in the study group and 37.5% patients in the control group (p = 0.59). Pain upon kneeling was present in 33.3% patients in the study group and 37.5% patients in the control group (p = 0.55). Walking in kneeling position elicited pain in 40% patients in the study group and 43.8% in the control group (p = 0.56). The mean visual analogue score for knee pain was 3.0 in the study group and 3.13 in the control group, with no statistically significant difference (p = 0.68). Unlike control group, where a persistent bony depression defect was observed at donor sites, no such defects were observed in the study group. Conclusion: Filling the defects of donor sites with HAP:BG blocks do not reduce the anterior knee symptoms in patients with ACL reconstruction using autogenous BPTB graft.

A Very Long-term Longitudinal Study on the Evolution and Clinical Outcomes of Persistent Iatrogenic Atrial Septal Defect After Cryoballoon Ablation

BackgroundPersistent iatrogenic atrial septal defect (iASD) is a common but poorly characterized complication after cryoballoon (CB) pulmonary vein isolation (PVI) procedures. We therefore investigate its prevalence, evolution, risk factors, and clinical outcomes in a prospective longitudinal study. MethodsA total of 108 patients (41 women, mean age 57 ± 11.3) underwent CB PVI for AF. Serial transesophageal echocardiography (TEE) was performed 9 months and then annually until 6 years after the procedure to study the characteristics of persistent iASD. ResultsPersistent iASD occurred in 33 (30.6%) patients 9 months after CB PVI. Spontaneous closure of iASD was found in 6 (22.2%) and 3 (15.8%) patients 2 and 3 years after the procedures, respectively. No spontaneous closure was observed on 4, 5, and 6-year TEE follow-up. The projected long-term persistence rate of iASD after CB PVI was therefore 20% (30.6% × 0.778 × 0.842). Using multivariate logistic regression, a higher number of cryoapplications (≥ 2 minutes) was the only independent predictor of persistent iASD 9 months after CB PVI (odds ratio [OR] 1.207; 95% confidence interval [CI], 1.033-1.411, P = 0.018). Two (1.9%) patients with significantly larger iASD size than the others (long diameter 12.6 ± 0.8 vs 3.7 ± 1.5 mm, P < 0.001; short diameter 10.9 ± 0.2 vs 3 ± 1.1 mm, P < 0.001) required percutaneous closure because of exertional dyspnea and right ventricular enlargement. Over 129.7 patient-years follow-up, during which iASD persisted, there was no occurrence of neurologic events. ConclusionsApproximately one fifth of patients undergoing CB PVI will have permanently persistent iASD. Patients with defect sizes of greater than 10 mm may need percutaneous closure due to significant left-to-right shunting.

Impact of primary hemostasis disorders on late (>30 days) major/life-threatening bleedings after TAVR

Periprocedural and late (>30 days) bleedings represent one of the major complications after Transcatheter Aortic Valve Replacement (TAVR) and have been identified as potential area for improved patient care. To evaluate the impact of ongoing primary hemostasis disorders on late major/life-threatening bleeding complications (MLBCs). Bleedings were assessed according to the Valve Academic Research Consortium-2 (VARC-2) criteria. CT-ADP, a surrogate marker of high molecular weight von Willebrand multimers proteolysis was assessed 24 h after the procedure. Ongoing primary hemostasis disorder was defined by a CT-ADP > 180 s. Amongst 372 patients who survived at 30 days, MLBCs occurred in 42 patients (11.3%) at a median follow-up of 383 days (interquartile range 188 to 574 days). MLBCs were mainly of gastrointestinal origin (42.9%) and were associated with increased overall mortality (HR 5.66; 95% CI [3.10–10.31]; P < 0.001) and cardiac mortality (HR 11.62; 95% CI [4.59–29.37]; P < 0.001). A 2.5 fold elevation of MLBCs could be evidenced in patients with a CT-ADP > 180 s (27.4 vs. 11.5%; P < 0.001). Multivariate regression analysis identified paravalvular leak (PVL) (HR 6.31; 95% CI [3.43–11.60]; P < 0.0001) and CT-ADP > 180 s (HR 3.08; [1.62–5.81]; P = 0.0005) as independent predictor of MLBCs Table 1 , Fig. 1 ). MLBCs after TAVR are frequent and associated with an increased morbidity and mortality. PVL and CT-ADP > 180s were identified as strong predictors for MLBCs. Our findings strongly suggest that the missing link between PVL and the risk of MLBCs is a persistent High Molecular Weight Von Willebrand defect. It may help physician to tailor follow-up and anti-thrombotic regimens of patients and improve clinical outcomes.

Defective levels of both circulating dendritic cells and T-regulatory cells correlate with risk of recurrence in cutaneous melanoma.

Immune markers in the peripheral blood of melanoma patients provide useful information for clinical management although there is poor consensus on circulating cells which could putatively reflect the disease activity and play a prognostic role. Here, we investigated both dendritic cells (DCs) and T-regulatory cells (Tregs). The number of DC subsets as myeloid (m) and plasmacytoid was measured by flowcytometry in 113 melanoma patients in different clinical stages and correlated with the disease activity to evaluate the recurrence free survival (RFS) calculated as difference between baseline and post-surgical values in relation to the criteria for the melanoma staging, as primary tumor removal, sentinel lymph node biopsy and completion of lymph node dissection. Circulating mDC levels were significantly lower in metastatic melanoma than in other stages and inversely correlated to Treg values while both populations were similarly expressed in inactive disease at stage I-III. Furthermore, the levels of these cells after melanoma removal were apparently related to the disease activity since their persistent defect reflected high risk of recurrence and reduced the RFS. This work highlighted the role of immune cell measurement for the management of melanoma activity and the identification of patients at potential risk of recurrence based on the mDC ratio.

Prognostic value of a new semiquantitative score system for adenosine stress myocardial perfusion by CMR

Cardiovascular magnetic resonance (CMR) provides information on myocardial ischemia through stress perfusion studies. In clinical practice, the grading of induced perfusion defects is performed by visual estimation of their extension. The aim of our study is to devise a score of the degree of ischemia and to test its prognostic value. Between 2009 and 2011, patients with diagnosed or suspected coronary artery disease underwent stress perfusion CMR. A score of ischemic burden was calculated on the basis of (1) stress-induced perfusion defect, (2) persistence, (3) transmurality, and (4) stress-induced contractile defect. Follow-up was censored after 4years and primary end-point was defined by a composite of death, heart failure episode, acute coronary syndrome, and ventricular arrhythmias. Univariate and multivariate logistic regressions were used to assess the strength of the association between the CMR ischemic variables, and the composite outcome. Forty-four of the 128 patients (34%) presented with adverse events, while 84 (66%) did not. Sixty-one patients (48%) had negative perfusion studies while 67 (52%) showed perfusion defect. Patients with positive perfusion studies and adverse events (n = 39) had higher number of segments with persistent defect (3.3 vs 1.3, p = 0.001) and highest score (19.6 vs 13.3 p = 0.012) than patients with positive perfusion studies and absence of events (n = 28). The number of segments with persistent defect showed the strongest predictive value of adverse events (OR 1.54; CI 1.19-2.00; p < 0.001). The score of ischemic burden proposed herein has prognostic value. Persistence of a perfusion defect has the strongest impact on prognosis. • Cardiovascular magnetic resonance provides information on myocardial ischemia by visual estimation of the presence of perfusion defects induced by stress. • There is not a standardized method for grading perfusion defects which, in practice, is performed by visual estimation of their extension. • As proven in this study, the integration of several parameters of perfusion defects (in addition to extension) into a semiquantitative score has prognostic value.

Evolution of 316L stainless steel feedstock due to laser powder bed fusion process

Some of the primary barriers to widespread adoption of metal additive manufacturing (AM) are persistent defect formation in built components, high material costs, and lack of consistency in powder feedstock. To generate more reliable, complex-shaped metal parts, it is crucial to understand how feedstock properties change with reuse and how that affects build mechanical performance. Powder particles interacting with the energy source, yet not consolidated into an AM part can undergo a range of dynamic thermal interactions, resulting in variable particle behavior if reused. In this work, we present a systematic study of 316L powder properties from the virgin state through thirty powder reuses in the laser powder bed fusion process. Thirteen powder characteristics and the resulting AM build mechanical properties were investigated for both powder states. Results show greater variability in part ductility for the virgin state. The feedstock exhibited minor changes to size distribution, bulk composition, and hardness with reuse, but significant changes to particle morphology, microstructure, magnetic properties, surface composition, and oxide thickness. Additionally, sieved powder, along with resulting fume/condensate and recoil ejecta (spatter) properties were characterized. Formation mechanisms are proposed. It was discovered that spatter leads to formation of single crystal ferrite through large degrees of supercooling and massive solidification. Ferrite content and consequently magnetic susceptibility of the powder also increases with reuse, suggesting potential for magnetic separation as a refining technique for altered feedstock.

Primary Hemostatic Disorders and Late Major Bleeding After Transcatheter Aortic Valve Replacement

BackgroundPeriprocedural and late (>30 days) bleedings represent major complications after transcatheter aortic valve replacement and have been identified as potential areas for improved patient care. ObjectivesThe authors sought to evaluate the impact of ongoing primary hemostasis disorders on late major/life-threatening bleeding complications (MLBCs). MethodsBleedings were assessed according to the VARC-2 (Valve Academic Research Consortium-2) criteria. Closure time of adenosine diphosphate (CT-ADP), a surrogate marker of high molecular weight von Willebrand multimers proteolysis was assessed 24 h after the procedure. Ongoing primary hemostasis disorder was defined by a CT-ADP >180 s. ResultsAmong 372 patients who survived at 30 days, MLBCs occurred in 42 patients (11.3%) at a median follow-up of 383 days (interquartile range: 188 to 574 days). MLBCs were mainly of gastrointestinal origin (42.8%) and were associated with increased overall mortality (hazard ratio [HR]: 5.66; 95% confidence interval [CI]: 3.10 to 10.31; p < 0.001) and cardiac mortality (HR: 11.62; 95% CI: 4.59 to 29.37; p < 0.001). A 2.5-fold elevation of MLBCs could be evidenced in patients with a CT-ADP > 180 s (27.4% vs. 11.5%; p < 0.001). Multivariate regression analysis identified paravalvular leak (PVL) (HR: 6.31; 95% CI: 3.43 to 11.60; p < 0.0001) and CT-ADP > 180 s (HR: 3.08; 95% CI: 1.62 to 5.81; p = 0.0005) as predictor of MLBCs. ConclusionsMLBCs after transcatheter aortic valve replacement are frequent and associated with an increased morbidity and mortality. PVL and CT-ADP >180 s were identified as strong predictors for MLBCs. These findings strongly suggest that persistent HMW defects contribute to enhanced bleeding risk in patients with residual PVL.

Mode of delivery following an OASIS and caesarean section rates

ObjectivesWhile the rate of obstetric anal sphincter injury (OASIS) is increasing, there is a lack of evidence on how best to advise women on mode of delivery (MOD) afterwards. The objectives of this study were to assess the clinical value of bowel symptoms, endoanal ultrasound and anorectal manometry in the management of pregnancies after an OASIS and evaluate the performance of different algorithms. Study DesignThis was a retrospective analysis of prospectively collected data in a university hospital perineal clinic. Women with OASIS undergoing endoanal ultrasound scan (EAUS) and anorectal manometry (AM) were included in this study (all women with an OASIS, except the asymptomatic 3a tears). A number of published algorithms were theoretically applied in this cohort to define recommended MOD after an OASIS. ResultsOut of the 233 women included in the study, 51 (21.9%) were symptomatic, 141 (60.5%) had persistent sphincter defects on EAUS and 124 (53.2%) had abnormal AM. One asymptomatic and five symptomatic women were found to have isolated internal anal sphincter (IAS) defects without external anal sphincter (EAS) defects. There were no women with low resting pressure and normal incremental squeeze pressure.The application of the algorithm requiring only one abnormal investigation to be recommended caesarean would have led to an 81.5% caesarean rate. If women with symptoms of anal incontinence or abnormal investigations would be advised for caesarean the rate would be 85.0%. Using the local protocol where symptomatic women only needed one of the two investigations to be abnormal but asymptomatic women were required to have both investigations being abnormal, 94 were considered for caesarean (40.3%). ConclusionThere is a wide range in the number of patients recommended to have caesarean section after an OASIS, depending on the used criteria and management algorithms. There is minimal additional information gained from identifying internal anal sphincter defects and measuring low resting pressures at manometry.

Metabolite profiling of Mycoplasma gallisepticum mutants, combined with bioinformatic analysis, can reveal the likely functions of virulence-associated genes

Mycoplasma gallisepticum is an economically important pathogen of commercial poultry. An improved understanding of M. gallisepticum pathogenesis is required to develop better control methods. We recently identified a number of M. gallisepticum mutants with defects in colonization and persistence in chickens using signature-tagged transposon mutagenesis. Loss of virulence was associated with mutations in a putative oligopeptide/dipeptide (opp/dpp) ATP-binding cassette (ABC) transporter (where the transposon was inserted into the MGA_0220 (oppD1) gene and two hypothetical proteins (encoded by MGA_1102 and MGA_0588), one of which (MGA_1102) contains a putative peptidase motif. To further characterise the function of these proteins, we compared the metabolome of each transposon mutant with that of wild type bacteria. Two independent LC/MS analyses revealed consistent significant decreases in the abundances of several amino acids and the dipeptide alanyl-glycine (Ala-Gly) in the MGA_0220 mutant, consistent with this protein being a peptide transporter. Similarly, lysine and Ala-Gly were significantly decreased in the MGA_1102 mutant, consistent with our bioinformatic analysis suggesting that MGA_1102 encodes a membrane-located peptidase. Few differences were observed in metabolite levels in the MGA_0588 mutant, suggesting that the disrupted protein has a non-metabolic role. Overall, this study indicates that metabolomics is a useful tool in the functional analysis of mutants.

Activity-dependent Signaling and Epigenetic Abnormalities in Mice Exposed to Postnatal Ethanol

Postnatal ethanol exposure has been shown to cause persistent defects in hippocampal synaptic plasticity and disrupt learning and memory processes. However, the mechanisms responsible for these abnormalities are less well studied. We evaluated the influence of postnatal ethanol exposure on several signaling and epigenetic changes and on expression of the activity-regulated cytoskeletal (Arc) protein in the hippocampus of adult offspring under baseline conditions and after a Y-maze spatial memory (SP) behavior (activity). Postnatal ethanol treatment impaired pCaMKIV and pCREB in naïve mice without affecting H4K8ac, H3K14ac and H3K9me2 levels. The Y-maze increased pCaMKIV, pCREB, H4K8ac and H3K14ac levels in saline-treated mice but not in ethanol-treated mice; while H3K9me2 levels were enhanced in ethanol-exposed animals compared to saline groups. Like previous observations, ethanol not only reduced Arc expression in naïve mice but also behaviorally induced Arc expression. ChIP results suggested that reduced H3K14ac and H4K8ac in the Arc gene promoter is because of impaired CBP, and increased H3K9me2 is due to the enhanced recruitment of G9a. The CB1R antagonist and a G9a/GLP inhibitor, which were shown to rescue postnatal ethanol-triggered synaptic plasticity and learning and memory deficits, were able to prevent the negative effects of ethanol on activity-dependent signaling, epigenetics and Arc expression. Together, these findings provide a molecular mechanism involving signaling and epigenetic cascades that collectively are responsible for the neurobehavioral deficits associated with an animal model of fetal alcohol spectrum disorders (FASD).

Static balloon atrial septostomy for the purpose of left heart intervention in postoperative adult CHD.

We retrospectively reviewed six procedures in five adults with CHD and collected demographic characteristics, details of the procedures, clinical outcome, and size changes of the iatrogenic atrial septal defect. The mean age at the time of the procedure was 35 years. The intended primary interventions were pulmonary vein isolation, stenting for pulmonary vein obstruction, and catheter ablation for focal atrial tachycardia. All static balloon atrial septostomies were effective, and the left heart interventions were successfully achieved via transseptal sheaths. There were no major complications associated with the static balloon atrial septostomy. There were no adverse clinical outcomes related to iatrogenic atrial septal defect, and the size of the defects regressed over time in all cases. Static balloon atrial septostomy can be a safe and useful technique in adult CHD patients needing left heart procedures. The thick interatrial septum found in postoperative patients may reduce the risk of persistent iatrogenic atrial septal defect.

In vivo annular repair using high-density collagen gel seeded with annulus fibrosus cells

ObjectiveThe aim is assessing the in vivo efficacy of annulus fibrosus (AF) cells seeded into collagen by enhancing the reparative process around annular defects and preventing further degeneration in a rat-tail model. Summary of background dataTreating disc herniation with discectomy may relieve the related symptoms but does not address the underlying pathology. The persistent annular defect may lead to re-herniation and further degeneration. We recently demonstrated that riboflavin crosslinked high-density collagen gels (HDC) can facilitate annular repair in vivo. Methods42 rats, tail disc punctured with an 18-gauge needle, were divided into 3 groups: untreated (n = 6), injected with crosslinked HDC (n = 18), and injected with AF cell-laden crosslinked HDC (n = 18). Ovine AF cells were mixed with HDC gels prior to injection. X-rays and MRIs were conducted over 5 weeks, determining disc height index (DHI), nucleus pulposus (NP) size, and hydration. Histological assessments evaluated the viability of implanted cells and degree of annular repair. ResultsAlthough average DHIs of both HDC gel groups were higher than those of the puncture control group at 5 weeks, the retention of disc height, NP size and hydration at 1 and 5 weeks was significant for the cellular group compared to the punctured, and at 5 weeks to the acellular group. Histological assessment indicated that AF cell-laden HDC gels have accelerated reparative sealing compared to acellular HDC gels. ConclusionsAF cell-laden HDC gels have the ability of better repairing annular defects than acellular gels after needle puncture. Statement of SignificanceThis project addresses the compelling demand of a sufficient treatment strategy for degenerative disc disease (DDD) perpetuated by annulus fibrosus (AF) injury, a major cause of morbidity and burden to health care systems. Our study is designed to answer the question of whether injectable, photo-crosslinked, high density collagen gels can seal defects in the annulus fibrosus of rats and prevent disc degeneration. Furthermore, we investigated whether the healing of AF defects will be enhanced by the delivery of AF cells (fibrochondrocytes) to these defects.The use of cell-laden collagen gels in spine surgery holds promise for a wide array of applications, from current discectomy procedures to future nucleus pulposus reparative therapies, and our group is excited about this potential.

Evaluation of Unroofed Coronary Sinus Syndrome Using Cardiovascular CT Angiography: An Observational Study.

The purpose of this study was to determine the prevalence of unroofed coronary sinus (CS) syndrome at a tertiary hospital and analyze the clinical information, cardiovascular CT angiography (CCTA) imaging findings, associated anomalies, and surgical treatment of the identified cases. We retrospectively searched the database of a tertiary hospital for cases of unroofed CS syndrome among patients who underwent CCTA for known or suspected congenital heart disease. After the prevalence of unroofed CS syndrome was determined, CCTA findings, associated cardiovascular abnormalities, presence or absence of airway compression, clinical information, and surgical outcome were recorded. A total of 23 patients with unroofed CS syndrome were identified, with the syndrome therefore having a prevalence of 0.36% among patients with congenital heart disease who underwent CCTA. The diagnostic accuracy of CCTA for unroofed CS syndrome was 100%, whereas that of echocardiography was 69%. Type I unroofed CS syndrome was the most commonly noted type (52% of patients). All 23 patients had associated cardiovascular anomalies, including persistent left superior vena cava (65% of patients) and atrial septal defect (65%). Surgery was performed for 70% of patients because of cardiovascular anomalies. Seven patients (30%) had associated secondary airway compression but did not require surgical correction. At our institution, the prevalence of unroofed CS syndrome was 0.36% among patients with congenital heart disease who underwent CCTA. CCTA has excellent diagnostic performance, delineating different subtypes of unroofed CS syndrome and associated cardiovascular planning for treatment of unroofed CS syndrome abnormalities, improving clinical decision making, and permitting preoperative planning for treatment of unroofed CS syndrome.

Defects in meiotic recombination delay progression through pachytene in Tex19.1\u2212/\u2212 mouse spermatocytes

Recombination, synapsis, chromosome segregation and gene expression are co-ordinately regulated during meiosis to ensure successful execution of this specialised cell division. Studies with multiple mutant mouse lines have shown that mouse spermatocytes possess quality control checkpoints that eliminate cells with persistent defects in chromosome synapsis. In addition, studies on Trip13mod/mod mice suggest that pachytene spermatocytes that successfully complete chromosome synapsis can undergo meiotic arrest in response to defects in recombination. Here, we present additional support for a meiotic recombination-dependent checkpoint using a different mutant mouse line, Tex19.1−/−. The appearance of early recombination foci is delayed in Tex19.1−/− spermatocytes during leptotene/zygotene, but some Tex19.1−/− spermatocytes still successfully synapse their chromosomes and we show that these spermatocytes are enriched for early recombination foci. Furthermore, we show that patterns of axis elongation, chromatin modifications and histone H1t expression are also all co-ordinately skewed towards earlier substages of pachytene in these autosomally synapsed Tex19.1−/− spermatocytes. We also show that this skew towards earlier pachytene substages occurs in the absence of elevated spermatocyte death in the population, that spermatocytes with features of early pachytene are present in late stage Tex19.1−/− testis tubules and that the delay in histone H1t expression in response to loss of Tex19.1 does not occur in a Spo11 mutant background. Taken together, these data suggest that a recombination-dependent checkpoint may be able to modulate pachytene progression in mouse spermatocytes to accommodate some types of recombination defect.