DNA synthesis is required for reprogramming mediated by stem cell fusion.

Embryonic stem cells (ESCs) can instruct the conversion of differentiated cells toward pluripotency following cell-to-cell fusion by a mechanism that is rapid but poorly understood. Here, we used centrifugal elutriation to enrich for mouse ESCs at sequential stages of the cell cycle and showed that ESCs in S/G2 phases have an enhanced capacity to dominantly reprogram lymphocytes and fibroblasts in heterokaryon and hybrid assays. Reprogramming success was associated with an ability to induce precocious nucleotide incorporation within the somatic partner nuclei in heterokaryons. BrdU pulse-labeling experiments revealed that virtually all successfully reprogrammed somatic nuclei, identified on the basis of Oct4 re-expression, had undergone DNA synthesis within 24 hr of fusion with ESCs. This was essential for successful reprogramming because drugs that inhibited DNA polymerase activity effectively blocked pluripotent conversion. These data indicate that nucleotide incorporation is an early and critical event in the epigenetic reprogramming of somatic cells in experimental ESC-heterokaryons.

High-density mapping of Koch's triangle during sinus rhythm and typical atrioventricular nodal re-entrant tachycardia, integrated with direct recording of atrio-ventricular node structure potential.

BACKGROUND: The mechanism of typical slow-fast atrioventricular nodal re-entrant tachycardia (AVNRT) and its anatomical and electrophysiological circuit inside the right atrium (RA) and Koch's Triangle (KT) are not well known. OBJECTIVE: To identify the potentials of the compact AV node and inferior extensions and to perform accurate mapping of the RA and KT in sinus rhythm (SR) and during AVNRT, to define the tachycardia circuit. METHODS: Consecutive patients with typical AVNRT were enrolled in 12 Italian centers and underwent mapping and ablation by means of a basket catheter with small electrode spacing for ultrahigh-density mapping and a modified signal-filtering toolset to record the potentials of the AV nodal structures. RESULTS: Forty-five consecutive cases of successful ablation of typical slow-fast AVNRT were included. The mean SR cycle length (CL) was 784.1 ± 6 ms and the mean tachycardia CL was 361.2 ± 54 ms. The AV node potential had a significantly shorter duration and higher amplitude in sinus rhythm than during tachycardia (60 ± 40 ms vs. 160 ± 40 ms, p < .001 and 0.3 ± 0.2 mV vs. 0.09 ± 0.12 mV, p < .001, respectively). The nodal potential duration extension was 169.4 ± 31 ms, resulting in a time-window coverage of 47.6 ± 9%. The recording of AV nodal structure potentials enabled us to obtain 100% coverage of the tachycardia CL during slow-fast AVNRT. CONCLUSION: Detailed recording of the potentials of nodal structures is possible by means of multipolar catheters for ultrahigh-density mapping, allowing 100% of the AVNRT CL to be covered. These results also have clinical implications for the ablation of right-septal and para-septal arrhythmias.

Alteplase Dose Assessment for Pleural infection Therapy (ADAPT) Study-2: Use of 2.5 mg alteplase as a starting intrapleural dose.

BACKGROUND AND OBJECTIVE: Intrapleural tissue plasminogen activator/deoxyribonuclease (tPA/DNase) therapy is increasingly used in pleural infection. Bleeding risks and costs associated with tPA remain the clinical concerns. Our dose de-escalation series aims to establish the lowest effective dosing regimen for tPA/DNase. This study assesses the intrapleural use of 2.5 mg tPA/5 mg DNase for pleural infection. METHODS: Consecutive patients with pleural infection treated with a starting regime of 2.5 mg tPA/5 mg DNase were included from two centres in Australia and UK. Escalation of tPA dose was permitted if clinical response was inadequate. RESULTS: Sixty-nine patients (mean age 61.0 years) received intrapleural 2.5 mg tPA/5 mg DNase. Most (88.4%) were treated successfully and discharged from hospital without surgery by 90 days. Patients received a median of 5 [interquartile range [IQR] = 3-6] doses of tPA/DNase. Total amount of tPA used per patient was 12.5 mg [median, IQR = 7.5-15.0]. Seventeen patients required dose escalation of tPA; most (n = 12) for attempted drainage of distant non-communicating locule(s). Treatment success was corroborated by clearance of pleural opacities on radiographs (from median 27.0% [IQR = 17.1-44.5] to 11.0% [IQR = 6.4-23.3] of hemithorax, p < 0.0001), increased pleural fluid drainage (1.98 L [median, IQR = 1.38-2.68] over 72 h following commencement of tPA/DNase) and reduction of serum C-reactive protein level (by 45.0% [IQR = 39.3-77.0] from baseline at day 5, p < 0.0001). Two patients required surgery. Six patients with significant comorbidities (e.g., advanced cancer) had ongoing infection when palliated and died. Two patients experienced self-limiting pleural bleeding and received blood transfusion. CONCLUSION: A starting intrapleural regime of 2.5 mg tPA/5 mg DNase, with up-titration if needed, can be effective and deserves further exploration.

Different roles for Tet1 and Tet2 proteins in reprogramming-mediated erasure of imprints induced by EGC fusion.

Genomic imprinting directs the allele-specific marking and expression of loci according to their parental origin. Differential DNA methylation at imprinted control regions (ICRs) is established in gametes and, although largely preserved through development, can be experimentally reset by fusing somatic cells with embryonic germ cell (EGC) lines. Here, we show that the Ten-Eleven Translocation proteins Tet1 and Tet2 participate in the efficient erasure of imprints in this model system. The fusion of B cells with EGCs initiates pluripotent reprogramming, in which rapid re-expression of Oct4 is accompanied by an accumulation of 5-hydroxymethylcytosine (5hmC) at several ICRs. Tet2 was required for the efficient reprogramming capacity of EGCs, whereas Tet1 was necessary to induce 5-methylcytosine oxidation specifically at ICRs. These data show that the Tet1 and Tet2 proteins have discrete roles in cell-fusion-mediated pluripotent reprogramming and imprint erasure in somatic cells.

Australia-wide cross-sectional survey of general practitioners' knowledge and practice of lung cancer screening.

BACKGROUND: Low-dose computed tomography (LDCT) screening can reduce lung cancer deaths in high-risk individuals, yet current Australian guidelines do not recommend screening. Little is known about current screening practices in Australia. AIM: To evaluate the proportion of general practitioners who report ordering lung cancer screening for their patients, identify factors associated with ordering lung cancer screening and assess general practitioners (GP) rationale for recommending screening and preference of composition of any future national targeted screening programme. METHODS: A survey was distributed to a nationally representative sample of 4000 Australian GP. The questionnaire included respondent demographics, self-reported screening practices, knowledge of screening recommendations, recent screening education, preference for recruitment methodologies for potential screening programmes and potential factors influencing the screening practices of GP. Two logistic regression models identified factors associated with self-reported chest X-ray (CXR) and LDCT screening within the past 12 months. RESULTS: A total of 323 GP completed the survey (participation rate 8.1%). Participants were mostly females (50.6%), from collective/group (79.1%) and metropolitan-based practices (73.5%). Despite the majority of responders understanding that screening is not recommended by Australian professional societies (71.2%), a substantial proportion of participants requested a CXR or LDCT screening (46.4% and 20.8% respectively). A variety of shared (GP reassurance, affordability of screening, believing screening is funded) and unique practice, educational and cognitive factors were associated with self-reported LDCT and CXR screening, with the strongest association being recent education about screening from radiology practices (odds ratio (aOR) for LDCT screening 10.4, P < 0.001). CONCLUSION: In Australia, lung cancer screening occurs outside a coordinated programme, and there is discordance between practice and national recommendations. This highlights an urgent need for clearer guidance from national and professional bodies.

The optimal timing of FDG-PET/CT in non-small cell lung cancer diagnosis and staging in an Australian centre.

BACKGROUND: Clinical practice guidelines and re-imbursement schedules vary in the recommended timing of FDG-PET/CT in the diagnostic evaluation of suspected or confirmed lung cancer. The aim was to estimate the probability of requiring more than one invasive test to complete diagnosis and staging in non-small cell lung cancer if FDG-PET/CT was used prior to initial biopsy (FDG-PET/CT First) compared to current Australian funding criteria (CT First). METHODS: Single-centre retrospective study of individuals with pathologically confirmed NSCLC without evidence of metastatic disease on baseline computed tomography (CT) of the chest. Decision tree analysis based on diagnosis and staging approaches estimated the probability of requiring more than one invasive biopsy. A Monte Carlo analysis with 1000 simulations was used to estimate decision tree precision. RESULTS: After exclusions, 115 patients were included with median (IQR) age of 71 (63-79) and 55.6% were male. The majority of cases were early stage (Stage I 43.5%, Stage II 19.1%) and adenocarcinoma (65.2%) histological subtype. The estimated probability of requiring more than one invasive biopsy with FDG-PET/CT prior was 0.12 compared to 0.19 when using the base case CT First scenario. Using the Monte Carlo analysis, the mean (95% CI) probability using the FDG-PET First approach was 0.15 (95%CI 0.12-0.20) versus 0.20 (95% CI 0.15-0.27) for the CT First approach. Only 7.8% had CT Chest-occult metastatic disease on FDG-PET that was accessible by percutaneous biopsy. CONCLUSION: FDG-PET/CT performed prior to initial biopsy may reduce the proportion of people with NSCLC who require more than one biopsy attempt, but the clinical significance and overall cost-utility requires evaluation.

Prospective validation of the RAPID clinical risk prediction score in adult patients with pleural infection: the PILOT study.

BACKGROUND: Over 30% of adult patients with pleural infection either die and/or require surgery. There is no robust means of predicting at baseline presentation which patients will suffer a poor clinical outcome. A validated risk prediction score would allow early identification of high-risk patients, potentially directing more aggressive treatment thereafter. OBJECTIVES: To prospectively assess a previously described risk score (the RAPID (Renal (urea), Age, fluid Purulence, Infection source, Dietary (albumin)) score) in adults with pleural infection. METHODS: Prospective observational cohort study that recruited patients undergoing treatment for pleural infection. RAPID score and risk category were calculated at baseline presentation. The primary outcome was mortality at 3 months; secondary outcomes were mortality at 12 months, length of hospital stay, need for thoracic surgery, failure of medical treatment and lung function at 3 months. RESULTS: Mortality data were available in 542 out of 546 patients recruited (99.3%). Overall mortality was 10% at 3 months (54 out of 542) and 19% at 12 months (102 out of 542). The RAPID risk category predicted mortality at 3 months. Low-risk mortality (RAPID score 0-2): five out of 222 (2.3%, 95% CI 0.9 to 5.7%); medium-risk mortality (RAPID score 3-4): 21 out of 228 (9.2%, 95% CI 6.0 to 13.7%); and high-risk mortality (RAPID score 5-7): 27 out of 92 (29.3%, 95% CI 21.0 to 39.2%). C-statistics for the scores at 3 months and 12 months were 0.78 (95% CI 0.71-0.83) and 0.77 (95% CI 0.72-0.82), respectively. CONCLUSIONS: The RAPID score stratifies adults with pleural infection according to increasing risk of mortality and should inform future research directed at improving outcomes in this patient population.

Middle-term Outcomes of Gatekeeper Implantation for Fecal Incontinence.

BACKGROUND: Intersphincteric injectable bulking agents are one of the current treatment options for fecal incontinence, failing behavioral and medical therapy. Gatekeeper showed promising short-term results, but long-term outcomes are unknown. OBJECTIVE: The purpose of this study was to clinically evaluate a prospective cohort of fecal incontinence patients up to 36 months after implantation of Gatekeeper. DESIGN: This was a prospective clinical study. SETTINGS: The study was conducted at a large university tertiary care hospital. PATIENTS: Consecutive female patients were eligible if fecal incontinence onset was ≥6 months before the first visit and symptoms were refractory to standard conservative measures. INTERVENTIONS: All of the patients underwent implantation of 4 or 6 Gatekeeper prostheses. Three-dimensional endoanal ultrasonography and high-resolution anorectal manometry were performed preoperatively and postoperatively at 2 and 3 months after implantation. MAIN OUTCOME MEASURES: The Cleveland Clinic Fecal Incontinence score was calculated at baseline and 1, 3, 12, 24, and 36 months postoperatively. RESULTS: Twenty patients (all women; median age, 59 y) were enrolled, and all implants were uneventful. Postoperative endoanal ultrasonography showed normal prosthesis localization in 16 patients (80%). At manometry, mean anal resting pressure significantly improved (57.8 ± 7.5 mm Hg; p = 0.0004). Mean preoperative Cleveland Clinic Fecal Incontinence score was 12.4 ± 1.8, with significant improvements initially documented at 3 months (4.9 ± 1.5; p < 0.0001) and sustained up to 36 months (4.9 ± 1.7; p < 0.0001). Patients receiving only 4 (compared with 6) prostheses and those experiencing pudendal neuropathy (compared with those who did not) showed significantly higher Cleveland Clinic Fecal Incontinence score values in the middle term. LIMITATIONS: The study was limited by its small sample size and absence of quality-of-life data. CONCLUSIONS: Initial improvements after Gatekeeper implantation for fecal incontinence are sustained in the middle term. Accurate preoperative evaluation of coexistent clinical conditions that may negatively affect outcomes is recommended for patient selection. See Video Abstract at http://links.lww.com/DCR/B109. RESULTADOS A MEDIANO PLAZO EN LA IMPLANTACIÓN DE GATEKEEPER PARA LA INCONTINENCIA FECAL: Los agentes de volumen inyectables interesfintéricos, son opciones actuales de tratamiento para la incontinencia fecal, ante fallas de terapias conductuales y médicas. Gatekeeper mostró resultados prometedores a corto plazo, pero resultados a largo plazo aún son desconocidos.Evaluar clínicamente una cohorte prospectiva de pacientes con incontinencia fecal, hasta 36 meses después de la implantación de Gatekeeper.Estudio clínico prospectivo.El estudio se realizó en un gran hospital universitario de atención terciaria.Fueron elegibles pacientes femeninas consecutivas, si el inicio de la incontinencia fecal, fue al menos 6 meses antes de la primera visita, y que los síntomas fueron refractarios a las medidas conservadoras estandarizadas.Todas las pacientes fueron sometidas a implantación de 4 o 6 prótesis Gatekeeper. Se realizó ecografía endoanal de 3D y manometría anorrectal de alta resolución, antes de la implantación y después a los 2 y 3 meses.Se calculó el puntaje de incontinencia fecal de la Cleveland Clinic al inicio, y a los 1, 3, 12, 24 y 36 meses después de la operación.Se inscribieron veinte pacientes (todas mujeres; con edad media de 59 años), y todos los implantes transcurrieron sin incidentes. La ecografía endoanal postoperatoria, mostró localización normal de la prótesis en 16 (80%) pacientes. A la manometría, la presión media de reposo anal, mejoró significativamente (57.8 ± 7.5 mmHg, p = 0.0004). La puntuación media preoperatoria de la incontinencia fecal de la Cleveland Clinic, fue de 12.35 ± 1.75, con mejoras significativas documentadas inicialmente a los 3 meses (4.9 ± 1.5, p <0.0001) y sostenidas hasta los 36 meses (4.9 ± 1.7, p <0.0001). Los pacientes que recibieron solo 4 prótesis (en comparación con 6) y que padecían neuropatía pudenda (en comparación con aquellas que no la padecían), mostraron valores de puntaje de Incontinencia Fecal de la Clínica Cleveland, significativamente más altos en el mediano plazo.El tamaño pequeño de la muestra y la ausencia de datos en calidad de vida.Las mejoras iniciales después de la implantación de Gatekeeper para la incontinencia fecal, se mantienen en el mediano plazo. Para la selección de pacientes, se recomienda una precisa evaluación preoperatoria de las condiciones clínicas coexistentes, que puedan afectar negativamente los resultados. Consulte Video Resumen en http://links.lww.com/DCR/B109.

Midland non-invasive ventilation score: a tool to predict non-invasive ventilation failure in people with acute hypercapnic respiratory failure.

Use of non-invasive ventilation (NIV) in patients with hypercapnic respiratory failure has clear benefits over invasive ventilation. Existing risk prediction models are complex and difficult to apply in the acute setting. We developed the Midland NIV score comprising only five parameters for use to predict NIV failure (in-hospital death or intubation) at initiation. Individuals with Midland NIV score of ≤11 (average 13% NIV failure) may be suitable for general ward care, compared to intensive care for those with Midland NIV score ≥12 (average 66% NIV failure rate). Prospective external validation is required.

Current lung cancer screening practice amongst general practitioners in Western Australia: a cross-sectional study.

Lung cancer screening with low dose computed tomography (LDCT) is recommended in the USA and Canada for high-risk smokers but not in Australia. We administered a cross-sectional survey to Western Australian general practitioners (GP). The majority (64/93, 69%) reported requesting a screening chest X-ray (42/93, 45%) and/or LDCT (38/93, 41%) in the past year. LDCT screening was more common if the GP had received education from radiology practices (odds ratio (OR) 2.81, P = 0.03) or if they believed screening is funded by the Medical Benefits Scheme (OR 3.57, P = 0.02). Lung cancer screening with LDCT is occurring outside a coordinated programme, contrary to Australian guidelines.

Effect of an Indwelling Pleural Catheter vs Talc Pleurodesis on Hospitalization Days in Patients With Malignant Pleural Effusion: The AMPLE Randomized Clinical Trial.

Importance: Indwelling pleural catheter and talc pleurodesis are established treatments for malignant pleural effusions among patients with poor prognosis. Objective: To determine whether indwelling pleural catheters are more effective than talc pleurodesis in reducing total hospitalization days in the remaining lifespan of patients with malignant pleural effusion. Design, Setting, and Participants: This open-label, randomized clinical trial included participants recruited from 9 centers in Australia, New Zealand, Singapore, and Hong Kong between July 2012 and October 2014; they were followed up for 12 months (study end date: October 16, 2015). Patients (n = 146) with symptomatic malignant pleural effusion who had not undergone indwelling pleural catheter or pleurodesis treatment were included. Interventions: Participants were randomized (1:1) to indwelling pleural catheter (n = 74) or talc pleurodesis (n = 72), minimized by malignancy (mesothelioma vs others) and trapped lung (vs not), and stratified by region (Australia vs Asia). Main Outcomes and Measures: The primary end point was the total number of days spent in hospital from procedure to death or to 12 months. Secondary outcomes included further pleural interventions, patient-reported breathlessness, quality-of-life measures, and adverse events. Results: Among the 146 patients who were randomized (median age, 70.5 years; 56.2% male), 2 withdrew before receiving the randomized intervention and were excluded. The indwelling pleural catheter group spent significantly fewer days in hospital than the pleurodesis group (median, 10.0 [interquartile range [IQR], 3-17] vs 12.0 [IQR, 7-21] days; P = .03; Hodges-Lehmann estimate of difference, 2.92 days; 95% CI, 0.43-5.84). The reduction was mainly in effusion-related hospitalization days (median, 1.0 [IQR, 1-3] day with the indwelling pleural catheter vs 4.0 (IQR, 3-6) days with pleurodesis; P < .001; Hodges-Lehmann estimate, 2.06 days; 95% CI, 1.53-2.58). Fewer patients randomized to indwelling pleural catheter required further ipsilateral invasive pleural drainages (4.1% vs 22.5%; difference, 18.4%; 95% CI, 7.7%-29.2%). There were no significant differences in improvements in breathlessness or quality of life offered by indwelling pleural catheter or talc pleurodesis. Adverse events were seen in 22 patients in the indwelling pleural catheter group (30 events) and 13 patients in the pleurodesis group (18 events). Conclusions and Relevance: Among patients with malignant pleural effusion, treatment with an indwelling pleural catheter vs talc pleurodesis resulted in fewer hospitalization days from treatment to death, but the magnitude of the difference is of uncertain clinical importance. These findings may help inform patient choice of management for pleural effusion. Trial Registration: anzctr.org.au Identifier: ACTRN12611000567921.

Huntingtin CAG-expansion mutation results in a dominant negative effect.

Introduction: Huntington's disease (HD) remains an incurable and fatal neurodegenerative disease long after CAG-expansion mutation in the huntingtin gene (HTT) was identified as the cause. The underlying pathological mechanism, whether HTT loss of function or gain of toxicity results from mutation, remains a matter of debate. Methods: In this study, we genetically modulated wild-type or mutant HTT expression levels in isogenic human embryonic stem cells to systematically investigate their contribution to HD-specific phenotypes. Results: Using highly reproducible and quantifiable in vitro micropattern-based assays, we observed comparable phenotypes with HD mutation and HTT depletion. However, halving endogenous wild-type HTT levels did not strongly recapitulate the HD phenotypes, arguing against a classical loss of function mechanism. Remarkably, expression of CAG-expanded HTT in non-HD cells induced HD like phenotypes akin to HTT depletion. Discussion: By corollary, these results indicate a dominant negative effect of mutated HTT on its wild-type counterpart. Complementation with additional copies of wild-type HTT ameliorated the HD-associated phenotypes, strongly supporting a classical dominant negative mechanism. Understanding the molecular basis of this dominant negative effect will guide the development of efficient clinical strategies to counteract the deleterious impact of mutant HTT on the wild-type HTT function.

Automated conduction velocity estimation based on isochronal activation of heart chambers.

BACKGROUND: Spatial differences in conduction velocity (CV) are critical for cardiac arrhythmias induction. We propose a method for an automated CV calculation to identify areas of slower conduction during cardiac arrhythmias and sinus rhythm. METHODS: Color-coded representations of the isochronal activation map using data coming from the RHYTHMIA™ Mapping System were reproduced by applying a temporal isochronal window at 20 ms. Geodesic distances of the 3D mesh were calculated using an algorithm selecting the minimum distance pathway (MDP). The CV estimation was performed considering points on the boundary of two spatially and temporally adjacent isochrones. For each of the boundary points of a given isochrone, the nearest boundary point of the consecutive isochrone was chosen, the MDP was evaluated, and a map of CV was created. The proposed method has been applied to a population of 29 patients. RESULTS: In all cases of perimitral atrial flutter (16 pts out of 29 (55%)), areas with significantly low CV (< 30 cm/s) were found. Half of the cases present regions with low CV located in the anterior wall. No case with low CV at the so-called LA isthmus was observed. Right atrial maps during common atrial flutters showed low CV areas mainly located in the inferior inter-atrial septum. No areas of low CV were observed in subjects without a history of atrial arrhythmia while pts affected by paroxysmal AF showed areas with a limited extension of low CV. CONCLUSIONS: The proposed software for automated CV estimation allows the identification of low CV areas, potentially helping electrophysiologists to plan the ablation strategy.

High-frequency and adaptive-like dynamics of human CD1 self-reactive T cells.

CD1 molecules present lipid antigens to T cells. An intriguing subset of human T cells recognize CD1-expressing cells without deliberately added lipids. Frequency, subset distribution, clonal composition, naïve-to-memory dynamic transition of these CD1 self-reactive T cells remain largely unknown. By screening libraries of T-cell clones, generated from CD4(+) or CD4(-) CD8(-) double negative (DN) T cells sorted from the same donors, and by limiting dilution analysis, we find that the frequency of CD1 self-reactive T cells is unexpectedly high in both T-cell subsets, in the range of 1/10-1/300 circulating T cells. These T cells predominantly recognize CD1a and CD1c and express diverse TCRs. Frequency comparisons of T-cell clones from sorted naïve and memory compartments of umbilical cord and adult blood show that CD1 self-reactive T cells are naïve at birth and undergo an age-dependent increase in the memory compartment, suggesting a naïve/memory adaptive-like population dynamics. CD1 self-reactive clones exhibit mostly Th1 and Th0 functional activities, depending on the subset and on the CD1 isotype restriction. These findings unveil the unanticipated relevance of self-lipid T-cell response in humans and clarify the basic parameters of the lipid-specific T-cell physiology.

Role of YAP in early ectodermal specification and a Huntington's Disease model of human neurulation.

The Hippo pathway, a highly conserved signaling cascade that functions as an integrator of molecular signals and biophysical states, ultimately impinges upon the transcription coactivator Yes-associated protein 1 (YAP). Hippo-YAP signaling has been shown to play key roles both at the early embryonic stages of implantation and gastrulation, and later during neurogenesis. To explore YAP's potential role in neurulation, we used self-organizing neuruloids grown from human embryonic stem cells on micropatterned substrates. We identified YAP activation as a key lineage determinant, first between neuronal ectoderm and nonneuronal ectoderm, and later between epidermis and neural crest, indicating that YAP activity can enhance the effect of BMP4 stimulation and therefore affect ectodermal specification at this developmental stage. Because aberrant Hippo-YAP signaling has been implicated in the pathology of Huntington's Disease (HD), we used isogenic mutant neuruloids to explore the relationship between signaling and the disease. We found that HD neuruloids demonstrate ectopic activation of gene targets of YAP and that pharmacological reduction of YAP's transcriptional activity can partially rescue the HD phenotype.

High-density mapping of Koch's triangle during sinus rhythm and typical AV nodal reentrant tachycardia: new insight.

BACKGROUND: Atrial activation during typical atrioventricular nodal reentrant tachycardia (AVNRT) exhibits anatomic variability and spatially heterogeneous propagation inside the Koch's triangle (KT). The mechanism of the reentrant circuit has not been elucidated yet. Aim of this study is to describe the distribution of Jackman and Haïssaguerre potentials within the KT and to explore the activation mode of the KT, in sinus rhythm and during the slow-fast AVNRT. METHODS: Forty-five consecutive cases of successful slow pathway (SP) ablation of typical slow-fast AVNRT from the CHARISMA registry were included. RESULTS: The KT geometry was obtained on the basis of the electroanatomic information using the Rhythmia mapping system (Boston Scientific) (mean number of points acquired inside the KT = 277 ± 47, mean mapping time = 11.9 ± 4 min). The postero-septal regions bounded anteriorly by the tricuspid annulus and posteriorly by the lateral wall toward the crista terminalis showed a higher prevalence of Jackman potentials than mid-postero-septal regions along the tendon of Todaro and coronary sinus (CS) (98% vs. 16%, p < 0.0001). Haïssaguerre potentials seemed to have a converse distribution across the KT (0% vs. 84%, p < 0.0001). Fast pathway insertion, as located during AVNRT, was mostly recorded in an antero-septal position (n = 36, 80%), rather than in a mid-septal (n = 6, 13.3%) or even postero-septal (n = 3, 7%) location. During typical slow-fast AVNRT, two types of propagation around the CS were discernible: anterior and posterior, n = 31 (69%), or only anterior, n = 14 (31%). During the first procedure, the SP was eliminated, and acute procedural success was achieved (median of 4 [3-5] RF ablations). CONCLUSION: High-density mapping of KT in AVNRT patients both during sinus rhythm and during tachycardia provides new electrophysiological insights. A better understanding and a more precise definition of the arrhythmogenic substrate in AVNRT patients may have prognostic value, especially in high-risk cases. TRIAL REGISTRATION: Catheter Ablation of Arrhythmias With High Density Mapping System in the Real World Practice (CHARISMA) URL: http://clinicaltrials.gov/ Identifier: NCT03793998.

Detection of multidrug resistance and extended-spectrum/plasmid-mediated AmpC beta-lactamase genes in Enterobacteriaceae isolates from diseased cats in Italy.

OBJECTIVES: The aim of this study was to determine the antimicrobial susceptibility of Enterobacteriaceae isolated from cats affected by diseases commonly encountered in practice, and to characterise the third-generation cephalosporin (3GC)-resistance molecular mechanisms involved. METHODS: Clinical samples (n = 100) included 58 rectal swabs from cats with diarrhoea, 31 nasal swabs from cats with clinical signs of upper respiratory tract disease, four ear swabs from cats with otitis, three conjunctival swabs from cats with conjunctivitis, two oral swabs from cats with stomatitis, one swab from a skin abscess and one urine sample from a cat with cystitis. A total of 125 Enterobacteriaceae were isolated from 90 cats. Escherichia coli was the most frequently isolated species (n = 65), followed by Enterobacter species (n = 20), Proteus species (n = 13), Citrobacter species (n = 12) and others (n = 15). Bacterial susceptibility testing was performed with respect to eight antimicrobial classes. Beta (ß)-lactamase genes were identified by PCR and nucleotide sequencing. RESULTS: Overall, the higher frequency of resistance was to amoxicillin-clavulanate (61.3%), trimethoprim/sulfamethoxazole (33.6%) and cefotaxime (32.8%). Thirty-six percent of the isolates (n = 45) were resistant to 3GCs. Of these isolates, 34 were tested by PCR and nucleotide sequencing and 23 were confirmed as encoding ß-lactamase genes. Fourteen 3GC-resistant isolates harboured extended-spectrum ß-lactamases (ESBLs) belonging to groups CTX-M-1 (n = 12, two of which were CTX-M-79), CTX-M-2 (n = 1) and CTX-M-9 (n = 1), as well as SHV-12 (n = 1) and TEM-92 (n = 1). Nine isolates had CMY-2 plasmid-mediated AmpC ß-lactamases (pAmpC). Thirty-one percent (n = 39) of the isolates were multidrug resistant (MDR) and were isolated from 34% (n = 31/90) of the cats. CONCLUSIONS AND RELEVANCE: A high frequency of MDR and ESBL/pAmpC ß-lactamase-producing Enterobacteriaceae were detected among bacteria isolated from a feline population in southern Italy with a variety of common clinical conditions, which poses limitations on therapeutic options for companion animals. We describe the first detection of CTX-M-79 and TEM-92 ESBL genes in isolates from cats.

The impact of perceived risk, screening eligibility and worry on preference for lung cancer screening: a cross-sectional survey.

Lung cancer screening is effective at reducing lung cancer deaths when individuals at greatest risk are screened. Recruitment initiatives target all current and former smokers, of whom only some are eligible for screening, potentially leading to discordance between screening preference and eligibility in ineligible individuals. The objective of the present study was to identify factors associated with preference for screening among ever-smokers. Ever-smokers aged 55-80 years attending outpatient clinics at three Australian hospitals were invited. The survey recorded: 1) demographics; 2) objective lung cancer risk and screening eligibility using the Prostate Lung Colon Ovarian 2012 risk model; and 3) perceived lung cancer risk, worry about and seriousness of lung cancer using a validated questionnaire. Multivariable ordinal logistic regression identified predictors of screening preference. The survey was completed by 283 individuals (response rate 27%). Preference for screening was high (72%) with no significant difference between low-dose computed tomography screening-eligible and -ineligible individuals (77% versus 68%, p=0.11). Worry about lung cancer (adjusted-proportional odds ratio (adj-OR) 1.31, 95% CI 1.08-1.58; p=0.007) and perceived seriousness of lung cancer (adj-OR 1.31, 95% CI 1.05-1.64; p=0.02) were associated with higher preference for lung cancer screening while screening eligibility was not. The concept of "early detection" was the most important driver to have screening while practical obstacles like difficulty travelling to the scan or taking time off work were the least important barriers to screening. Most current or former smokers prefer to undergo screening. Worry about lung cancer and perceived seriousness of the diagnosis are more important drivers for screening preference than eligibility status.