Exploring Breast Surgeons' Attitudes on Universal Genetic Testing: A Qualitative Study.

BACKGROUND: The American Society of Breast Surgeons released a consensus statement that genetic testing should be made available to all patients with a personal history of breast cancer. However, it is not clear whether physicians feel comfortable with universal genetic testing (UGT) or if they have sufficient knowledge to interpret results and manage them appropriately. OBJECTIVE: The purpose of this study was to explore breast surgeons' attitudes toward UGT. METHODS: Breast surgeons were consented and scheduled for a semi-structured virtual interview. Transcripts were uploaded into qualitative analysis software where they were exhaustively and iteratively coded. Codes were then organized into higher-order categories and themes and data saturation were assessed. RESULTS: Thirty-one surgeons completed the qualitative interview. Most surgeons practiced in the academic or community setting and most practiced in the Midwest (71.0%). The majority (90.3%) reported having a structured genetics program. The majority (96.8%) referred their patients to genetics for counseling and most preferred ordering testing through a genetic services provider. Some surgeons had concerns about access to genetic services. A minority of surgeons order UGT for all newly diagnosed breast cancer patients. The majority of respondents thought that more training in genetics was needed for surgeons. Many surgeons expressed concern about the psychosocial effects of UGT on patients. CONCLUSIONS: Many surgeons expressed concerns about UGT, mainly related to discomfort with their training, access to genetic services, and the psychosocial impact on their patients. Future work is needed to determine how to improve surgeon's comfort level in implementing UGT.

Ischemic myelomalacia and closed spinal dysraphism in multiple finishing swine.

Ischemic myelomalacia secondary to fibrocartilaginous emboli (FCE) is an idiopathic disease in humans and animals. On the other hand, congenital spinal cord malformations result from neural tube defects in fetal development (ie, spinal dysraphism), with structural anomalies referred to collectively as myelodysplasia. Spinal dysraphisms are frequently accompanied by skin and vertebral abnormalities because of the embryogenic relationship. In this observational case study, we report the pathologic findings of 13, 18- to 24-weeks-old pigs from a large conventional operation that presented with acute paraparesis. Ischemic myelomalacia secondary to FCE was observed in 5 of 13 examined pigs. Congenital spinal cord malformations located between the caudal thoracic and sacral spinal cord were identified in 7 pigs, with structural abnormalities that ranged from diplomyelia/split cord malformation to segmental spinal dysgenesis (myelodysplasia) to caudal agenesis. Concurrent myelomalacia and congenital spinal cord malformations in the same or different sites were noted in 2 pigs. No spinal lesion was observed in 3 pigs. Although gross vertebral abnormalities were not observed herein, intervertebral instability due to minor defects in the articular facets, as well as other unidentified factors, is suspected to contribute high incidence of FCE. It is likely that these congenital malformations were previously underdiagnosed or are possibly new conditions associated with continuous inbreeding and genetic improvement in the modern swine industry.

Adjunctive use of fluoroscopy during MitraClip implantation reduces procedural complexity: The parallax technique.

BACKGROUND: During MitraClip implantation sub-valvular correction of trajectory and/or alignment may increase adverse clip or leaflet events. With systematic adjunctive use of fluoroscopy ("Parallax technique"), we aimed to assess parameters that minimize the need for corrective measures and help increase procedural efficiency. METHODS: We retrospectively analyzed 30 patients without (Fl-) and 39 patients utilizing adjunctive fluoroscopy (Fl+) during MitraClip implantation. After establishing trajectory and supra-valvular alignment, the Parallax technique was utilized. Trajectory and alignment are maintained during advancement. RESULTS: All patients had 3 or 4+ MR. There were no differences in baseline demographics. The average number of clips (Fl- vs Fl+) was 1.72 ± 0.8 vs 1.59 ± 0.5, p = .57. For the first clip, the need for sub-valvular alignment (80% vs. 36%, p = .0001), eversion with retraction back to left atrium (23% vs. 10%, p = .001) and the number of grasps (2.3 ± 1.2 vs 1.4 ± 0.9) was reduced. The time from transseptal puncture to first clip deployment (71 ± 21 vs 44 ± 16 min, p = .01) was reduced. Procedural success was achieved in all but one patient in the Fl- group (p = ns). There were no differences noted for in-hospital or 30-day outcomes. CONCLUSIONS: Systematic use of a simple and easy to implement "Parallax technique" was associated with reduced need for sub-valvular manipulation and was associated with improved procedural times. Further larger scale studies are needed to assess the applicability of the technique.

Advanced spectroscopic analysis and 15N-isotopic labelling study of nitrate and nitrite reduction to ammonia and nitrous oxide by E. coli.

Nitrate and nitrite reduction to ammonia and nitrous oxide by anaerobic E. coli batch cultures is investigated by advanced spectroscopic analytical techniques with 15N-isotopic labelling. Non-invasive, in situ analysis of the headspace is achieved using White cell FTIR and cavity-enhanced Raman (CERS) spectroscopies alongside liquid-phase Raman spectroscopy. For gas-phase analysis, White cell FTIR measures CO2, ethanol and N2O while CERS allows H2, N2 and O2 monitoring. The 6 m pathlength White cell affords trace gas detection of N2O with a noise equivalent detection limit of 60 nbar or 60 ppbv in 1 atm. Quantitative analysis is discussed for all four 14N/15N-isotopomers of N2O. Monobasic and dibasic phosphates, acetate, formate, glucose and NO3- concentrations are obtained by liquid-phase Raman spectroscopy, with a noise equivalent detection limit of 0.6 mM for NO3- at 300 s integration time. Concentrations of the phosphate anions are used to calculate the pH in situ using a modified Henderson-Hasselbalch equation. NO2- concentrations are determined by sampling for colorimetric analysis and NH4+ by basifying samples to release 14N/15N-isotopomers of NH3 for measurement in a second FTIR White cell. The reductions of 15NO3-, 15NO2-, and mixed 15NO3- and 14NO2- by anaerobic E. coli batch cultures are discussed. In a major pathway, NO3- is reduced to NH4+via NO2-, with the bulk of NO2- reduction occurring after NO3- depletion. Using isotopically labelled 15NO3-, 15NH4+ production is distinguished from background 14NH4+ in the growth medium. In a minor pathway, NO2- is reduced to N2O via the toxic radical NO. With excellent detection sensitivities, N2O serves as a monitor for trace NO2- reduction, even when cells are predominantly reducing NO3-. The analysis of N2O isotopomers reveals that for cultures supplemented with mixed 15NO3- and 14NO2- enzymatic activity to reduce 14NO2- occurs immediately, even before 15NO3- reduction begins. Optical density and pH measurements are discussed in the context of acetate, formate and CO2 production. H2 production is repressed by NO3-; but in experiments with NO2- supplementation only, CERS detects H2 produced by formate disproportionation after NO2- depletion.

Preserving the organ donor pool and suprahepatic vena cava: Case series of transverse hepatectomy for polycystic liver disease.

Management of symptomatic polycystic liver disease (PLD) has remained primarily unchanged since the early 20th century when multiple case reports described management of non-parasitic liver cysts. In 1968, Lin et al. described the fenestration procedure, "aspiration of the cysts, incision, partial excision with or without external drainage, or marsupilization and anastomosis to the gastrointestinal tract". Further surgical options have included cyst sclerotherapy, laparoscopic cyst aspiration, partial hepatectomy, and orthotopic liver transplant (OLT). Recently there has been discussion of medical management with somatostatin analogs to reduce hepatomegaly in PLD with varying success. There is no current consensus on treatment or standard of care for symptomatic PLD, it is largely up to surgeon preference and ability; however, there has been a movement toward early OLT with Model for End-Stage Liver Disease (MELD) score exception points. This case series reviews two female patients with normal renal and hepatic function with symptomatic PLD treated with transverse hepatectomy. We propose that patients suffering from symptomatic PLD, with retained renal and hepatic function, can be treated with transverse hepatectomy conserving limited donor livers for decompensated patients; moreover, transverse hepatectomy does not disrupt the major suprahepatic vena cava preserving potential surgical access for future OLT.

Transjugular mitral valve repair with the MitraClip: A step-by-step guide.

The MitraClip procedure is carried out almost exclusively via the transfemoral approach. However, in some patients transfemoral delivery of MitraClip is not technically feasible (e.g., occluded inferior vena cava or tortuous/obstructive iliofemoral venous anatomy). The technical considerations and challenges of the MitraClip procedure are amplified when an alternate route is considered. We describe a successful case of MitraClip performed via the right internal jugular (IJ) approach in a patient with a flail A3 scallop and previous mitral valve repair. We reviewed prior cases in the literature and discuss step-by-step the pertinent clinical and technical considerations for performing this procedure via the transjugular route. In summary, the right IJ access site provides a reasonable alternative to perform the MitraClip procedure in cases where femoral access is contraindicated or prohibitive. A thorough understanding of the technical considerations is crucial in improving procedural success rates.

A novel clock-face method for characterizing peridevice leaks after left atrial appendage occlusion.

OBJECTIVES: To propose a novel method for mapping leak location and frequency to a clock-face representation of the left atrial appendage (LAA) ostium. BACKGROUND: LAA occlusion with the Watchman device (WD) is an established therapy to reduce thromboembolic events in patients with atrial fibrillation (AF) and intolerance to long-term oral anticoagulation. Postimplantation leaks are known sequelae, but leak locations and characteristics are poorly described. METHODS: We retrospectively reviewed 101 consecutive WD implants from April 2015 to February 2018. Leak locations from 6-week post-implant transesophageal echocardiograms were mapped to a clock-face representation of the LAA ostium: 12:00 as cranial near the limbus, 3:00 as anterior toward the pulmonary artery, 6:00 as caudal near the mitral annulus, and 9:00 as posterior. Patient demographics, LAA dimensions, and procedural characteristics were also collected. RESULTS: Thirty-four patients had ≥1 leak totaling 45 leaks at 6-week follow-up. Baseline patient demographics showed a mean age 77, CHA2 DS2 VASc 4.69, and 64% of patients with permanent AF. No patient had a detectable leak at the time of implant. At 6 weeks, mean leak size was 2.67 ± 0.89 mm with no leak over 5 mm (largest 4.60 mm). Most leaks occurred along the posterior 6:00-12:00 segment (39/45) and the 6:00-9:00 quadrant (16/45). CONCLUSION: Six-week post-WD implant leaks localize to the posterior LAA ostium. This could result from the elliptical LAA orifice, differential LAA tissue composition, or implantation technique. This study provides a novel method for describing the location of post-implant leaks and serves as the basis for further investigations.

Transseptal access for left heart structural interventions in the setting of prior atrial septal defect closure.

A transseptal puncture is critical for "left-sided" structural heart interventions. Procedures such as transcatheter edge-to-edge repair (MitraClip) and left atrial appendage (LAA) closure (Watchman) require precise puncture of the interatrial septum (IAS), and the presence of a prior atrial septal defect (ASD) closure device poses a challenge. We aim to present a successfully completed case of MitraClip and Watchman in the presence of ASD closure device in two different patients. A review of the literature will be reported, and pertinent clinical and technical considerations will be discussed in depth to achieve procedural success. In summary, transseptal puncture for left heart structural interventions is feasible in the presence of a prior ASD/patent foramen ovale closure device. A detailed understanding of the anatomical considerations as well as the use of multimodality imaging to evaluate the IAS will aid in improving procedural success rates.

Targeting Cancer with Genetically Engineered TCR T Cells.

The adoptive cell transfer (ACT) of genetically engineered T cell receptor (TCR) T cells is one of the burgeoning fields of immunotherapy, with promising results in current clinical trials. Presently, clinicaltrials.gov has over 200 active trials involving adoptive cell therapy. The ACT of genetically engineered T cells not only allows the ability to select for TCRs with desired properties such as high-affinity receptors and tumor reactivity but to further enhance those receptors allowing for better targeting and killing of cancer cells in patients. Moreover, the addition of genetic material, including cytokines and cytokine receptors, can increase the survival and persistence of the T cell allowing for complete and sustained remission of cancer targets. The potential for improvement in adoptive cell therapy is limitless, with genetic modifications targeting to improve weaknesses of ACT and to thus enhance receptor affinity and functional avidity of the genetically engineered T cells.

On-line analysis and in situ pH monitoring of mixed acid fermentation by Escherichia coli using combined FTIR and Raman techniques.

We introduce an experimental setup allowing continuous monitoring of bacterial fermentation processes by simultaneous optical density (OD) measurements, long-path FTIR headspace monitoring of CO2, acetaldehyde and ethanol, and liquid Raman spectroscopy of acetate, formate, and phosphate anions, without sampling. We discuss which spectral features are best suited for detection, and how to obtain partial pressures and concentrations by integrations and least squares fitting of spectral features. Noise equivalent detection limits are about 2.6 mM for acetate and 3.6 mM for formate at 5 min integration time, improving to 0.75 mM for acetate and 1.0 mM for formate at 1 h integration. The analytical range extends to at least 1 M with a standard deviation of percentage error of about 8%. The measurement of the anions of the phosphate buffer allows the spectroscopic, in situ determination of the pH of the bacterial suspension via a modified Henderson-Hasselbalch equation in the 6-8 pH range with an accuracy better than 0.1. The 4 m White cell FTIR measurements provide noise equivalent detection limits of 0.21 µbar for acetaldehyde and 0.26 µbar for ethanol in the gas phase, corresponding to 3.2 µM acetaldehyde and 22 µM ethanol in solution, using Henry's law. The analytical dynamic range exceeds 1 mbar ethanol corresponding to 85 mM in solution. As an application example, the mixed acid fermentation of Escherichia coli is studied. The production of CO2, ethanol, acetaldehyde, acids such as formate and acetate, and the changes in pH are discussed in the context of the mixed acid fermentation pathways. Formate decomposition into CO2 and H2 is found to be governed by a zeroth-order kinetic rate law, showing that adding exogenous formate to a bioreactor with E. coli is expected to have no beneficial effect on the rate of formate decomposition and biohydrogen production.

Cavity-Enhanced Raman and Helmholtz Resonator Photoacoustic Spectroscopy to Monitor the Mixed Sugar Metabolism of E. coli.

We introduce and compare two powerful new techniques for headspace gas analysis above bacterial batch cultures by spectroscopy, Raman spectroscopy enhanced in an optical cavity (CERS), and photoacoustic detection in a differential Helmholtz resonator (DHR). Both techniques are able to monitor O2 and CO2 and its isotopomers with excellent sensitivity and time resolution to characterize bacterial growth and metabolism. We discuss and show some of the shortcomings of more conventional optical density (OD) measurements if used on their own without more sophisticated complementary measurements. The spectroscopic measurements can clearly and unambiguously distinguish the main phases of bacterial growth in the two media studied, LB and M9. We demonstrate how 13C isotopic labeling of sugars combined with spectroscopic detection allows the study of bacterial mixed sugar metabolism to establish whether sugars are sequentially or simultaneously metabolized. For E. coli, we have characterized the shift from glucose to lactose metabolism without a classic diauxic lag phase. DHR and CERS are shown to be cost-effective and highly selective analytical tools in the biosciences and in biotechnology, complementing and superseding existing conventional techniques. They also provide new capabilities for mechanistic investigations and show a great deal of promise for use in stable isotope bioassays.

Iatrogenic atrial septal defect closure after transseptal mitral valve interventions: Indications and outcomes.

OBJECTIVES: Review indications and outcomes for transcatheter iatrogenic atrial septal defect (iASD) closure in patients undergoing MitraClip or transseptal (TS) mitral valve-in-valve/ring (ViV/ViR) procedures. BACKGROUND: Mitral valve transcatheter interventions require large-diameter TS sheaths that can result in iASDs that necessitate post-procedure transcatheter closure. Although the presence of iASD has been well-described, indications for closure and outcomes after TS mitral valve interventions have not been reported. METHODS: Patients undergoing MitraClip repair and ViV or ViR transcatheter mitral valve replacement (TMVR) from February 14, 2014, to January 16, 2018, were studied retrospectively in this single center study. RESULTS: Seventeen patients had iASD closure: 11 MitraClip and 6 TMVR (5 ViV, 1 ViR). Indications for iASD closure included large iASD (n = 7), large left-to-right shunt (n = 9), pulmonary hypertension (n = 8), large right-to-left shunt (n = 1), severe RV dysfunction (n = 2), thin/aneurysmal septum (n = 2), and mobile material on pacemaker leads (n = 2). Closures were performed without complications using Amplatzer septal occluders. At 30 days, 94% of subjects (n = 16) were alive with one patient deceased from unknown causes. There were no myocardial infarctions or strokes. At 12 months, follow-up was available for 14 of 17 patients, and 71% of patients (10/14) were alive. One patient died due to cardiac causes, two from noncardiac causes and one for unknown reasons. There was one myocardial infarction, one intraparenchymal hemorrhage, and no ischemic strokes. CONCLUSIONS: The most common reasons for iASD closure after TS MV procedures are: large ASD unlikely to spontaneously close, large left-to-right shunt, and pulmonary hypertension. Patients who required iASD closure had low 30-day mortality but higher one-year mortality potentially reflecting a population with substantial comorbidities.

Usable implantation depth for watchman left atrial appendage occlusion is greater with appendage angiography than transesophageal echocardiography.

OBJECTIVES: To compare left atrial appendage (LAA) angiography to transesophageal echocardiography (TEE) for assessing usable LAA depth. BACKGROUND: TEE is typically employed for procedural measurement of LAA ostial diameter and depth. Since angiography enhances distal LAA anatomy, we sought to compare angiography to TEE for determining usable LAA depth. METHODS: Seventy five Watchman device cases were retrospectively evaluated. Two independent cardiologists measured intraoperative LAA ostial diameter and depth at standard 0°, 45°, 90°, and 135° TEE omniplane views and in the right anterior oblique (RAO) 30°, caudal (CAUD) 30° angiographic view. RESULTS: The average age and CHA2 DS2 VASc score were 74 (±7.2) years and 4.6 (±1.3), respectively. The average ostial diameter and depth (mm) by TEE were 0°: 19.6 and 26.5; 45°: 17.5 and 26.6; 90°: 18.3 and 25.1; 135°: 19.5 and 23.3. The ostial diameter and depth (mm) by RAO 30° CAUD 30° angiography were 21.1 and 29.7. This angiographic view corresponds to a TEE view between 90° and 135°. In comparison to angiography, TEE 90° underestimated the LAA ostial diameter by 2.9 ± 3.7 mm (P < 0.001) and by 1.9 ± 4.0 mm at TEE 135° (P < 0.01); Pearson's r 0.53 angiography/TEE 90° and 0.50 angiography/TEE 135°. More importantly, TEE 90° underestimated the true usable LAA depth by 5.4 ± 5.8 mm (P < 0.001) and by 7.3 ± 6.1 mm at TEE 135° (P < 0.001); Pearson's r 0.39 angiography/TEE 90° and 0.30 angiography/TEE 135°. CONCLUSIONS: Compared to TEE, LAA angiography provides additional depth information and may be particularly valuable when patients have insufficient depth for Watchman by TEE measures.

Intraprocedural direct left atrial and wedge pressure correlation during transcatheter mitral valve repair: Results from a single center registry.

OBJECTIVES: This study investigates the correlation of occlusive wedge pressure (WP) with direct left atrial (LA) pressure in patients with severe mitral regurgitation (MR) undergoing transcatheter mitral valve repair (TMVr) with MitraClip. BACKGROUND: There is interest in acquiring objective hemodynamic parameters for intraprocedural guidance in patients undergoing MitraClip. METHODS: The study included 94 patients with severe MR at prohibitive surgical risk who underwent MitraClip at the University of California Davis Medical Center between 2014 and 2016. RESULTS: An average of 1.8 ± 0.7 clips were used to achieve MR grade of 2+ or less in 99% of patients. Correlation analysis of all (n = 236) pre-clip, inter-clip, and final-clip WP and LA pressures yielded a Pearson's R (r) of 0.85 and 0.79 for mean WP vs mean LA and WP V vs LA V, respectively. Median LA V to mean LA ratio (LAV:mLA) was 1.75 (IQR 1.5-1.9). 79% (n = 74) of patients had LAV:mLA ratio ≥ 1.5 with associated WP V vs LA V correlation (r) of 0.83. In patients with LAV:mLA ratio < 1.5, the correlation (r) was 0.69. Baseline characteristics were not significantly different between patients with LAV:mLA ratio ≥ 1.5 and patients with LAV:mLA ratio < 1.5. Post-procedure, median LA V: mean LA ratio decreased from 1.75 to 1.4, P = 0.0001. CONCLUSIONS: Correlation between WP and direct LA pressure in patients with severe MR undergoing Mitraclip is modest. Caution is advised when using WP to approximate LA pressure intraprocedurally, especially in patients with baseline low LAV:mLA ratios.

Altered Peptide Ligands Impact the Diversity of Polyfunctional Phenotypes in T Cell Receptor Gene-Modified T Cells.

The use of T cell receptor (TCR) gene-modified T cells in adoptive cell transfer has had promising clinical success, but often, simple preclinical evaluation does not necessarily accurately predict treatment efficacy or safety. Preclinical studies generally evaluate one or a limited number of type 1 cytokines to assess antigen recognition. However, recent studies have implicated other "typed" T cells in effective anti-tumor/viral immunity, and limited functional evaluations may underestimate cross-reactivity. In this study, we use an altered peptide ligand (APL) model and multi-dimensional flow cytometry to evaluate polyfunctionality of TCR gene-modified T cells. Evaluating six cytokines and the lytic marker CD107a on a per cell basis revealed remarkably diverse polyfunctional phenotypes within a single T cell culture and among peripheral blood lymphocyte (PBL) donors. This polyfunctional assessment identified unexpected phenotypes, including cells producing both type 1 and type 2 cytokines, and highlighted interferon γneg (IFNγneg) antigen-reactive populations overlooked in our previous studies. Additionally, APLs skewed functional phenotypes to be less polyfunctional, which was not necessarily related to changes in TCR-peptide-major histocompatibility complex (pMHC) affinity. A better understanding of gene-modified T cell functional diversity may help identify optimal therapeutic phenotypes, predict clinical responses, anticipate off-target recognition, and improve the design and delivery of TCR gene-modified T cells.

Sizing of patent ductus arteriosus in adults for transcatheter closure using the balloon pull-through technique.

OBJECTIVES: To describe a novel balloon sizing technique used during adult transcatheter patent ductus arteriosus (PDA) closure. In addition, to determine the clinical and procedural outcomes in six patients who underwent PDA balloon sizing with subsequent deployment of a PDA occluder device. BACKGROUND: Transcatheter PDA closure in adults has excellent safety and procedural outcomes. However, PDA sizing in adults can be challenging due to variable defect size, high flow state, or anatomical complexity. We describe a series of six cases where the balloon- pull through technique was successfully performed for PDA sizing prior to transcatheter closure. METHODS: Consecutive adult patients undergoing adult PDA closure at our institution were studied retrospectively. A partially inflated sizing balloon was pulled through the defect from the aorta into the pulmonary artery and the balloon waist diameter was measured. Procedural success and clinical outcomes were obtained. RESULTS: Six adult patients underwent successful balloon pull-through technique for PDA sizing during transcatheter PDA closure, since conventional angiography often gave suboptimal opacification of the defect. All PDAs were treated with closure devices based on balloon PDA sizing with complete closure and no complications. In three patients that underwent preprocedure computed tomography, the balloon size matched the CT derived measurements. CONCLUSION: The balloon pull-through technique for PDA sizing is a safe and accurate sizing modality in adults undergoing transcatheter PDA closure.

Initial clinical experience with the FlexPoint Steerable Transseptal Needle in left-sided structural heart procedures.

OBJECTIVES: The purpose of this study is to describe the initial clinical experience with a steerable transseptal needle (STSN) for left-sided structural heart procedures. BACKGROUND: Targeted transseptal (TS) puncture is required for many structural heart procedures, and the use of a steerable needle has not previously been described. METHODS: Consecutive patients undergoing structural heart interventions with targeted TS puncture under transesophageal echocardiographic (TEE) and fluoroscopic guidance were studied. The STSN was used in all patients with a standard commercial TS sheath. Deflection of the needle was performed "real time" to achieve localization of the TS puncture site. RESULTS: Twenty-seven patients underwent STSN puncture of the interatrial septum. In all cases, the needle could be deflected in vivo to achieve optimal tenting and localization of the puncture site without having to remove or reshape the needle. The needle was deflected to match a wide range of right atrial diameters (width 4.3 ± 0.9 cm and length 6.0 ± 0.9 cm in the 4-chamber view). In two patients with prior mitral valve surgery and a fibrotic septum, assisted crossing was achieved using the piercing stylet in one patient, and Bovie energy in the other. There were no procedural complications, and all patients had successful completion of the intended structural heart procedure. CONCLUSIONS: The STSN needle can be used to target the intended puncture location on the interatrial septum with real-time adjustable deflection without the need to remove and reshape the needle. In all cases crossing was successful and there were no complications.

Cavity-Enhanced Raman Spectroscopy in the Biosciences: In Situ, Multicomponent, and Isotope Selective Gas Measurements To Study Hydrogen Production and Consumption by Escherichia coli.

Recently we introduced cavity-enhanced Raman spectroscopy (CERS) with optical feedback cw-diode lasers as a sensitive analytical tool. Here we report improvements made on the technique and its first application in the biosciences for in situ, multicomponent, and isotope selective gas measurements to study hydrogen production and consumption by Escherichia coli. Under anaerobic conditions, cultures grown on rich media supplemented with d-glucose or glycerol produce H2 and simultaneously consume some of it. By introducing D2 in the headspace, hydrogen production and consumption could be separated due to the distinct spectroscopic signatures of isotopomers. Different phases with distinctly different kinetic regimes of H2 and CO2 production and D2 consumption were identified. Some of the D2 consumed is converted back to H2 via H/D exchange with the solvent. HD was formed only as a minor component. This reflects either that H/D exchange at hydrogenase active sites is rapid compared to the rate of recombination, rapid recapture of HD occurs after the molecule is formed, or that the active sites where D2 oxidation and proton reduction occur are physically separated. Whereas in glucose supplemented cultures, addition of D2 led to an increase in H2 produced, while the yield of CO2 remained unchanged; with glycerol, addition of D2 led not only to increased yields of H2, but also significantly increased CO2 production, reflecting an impact on fermentation pathways. Addition of CO was found to completely inhibit H2 production and significantly reduce D2 oxidation, indicating at least some role for O2-tolerant Hyd-1 in D2 consumption.

Accuracy and procedural characteristics of standard needle compared with radiofrequency needle transseptal puncture for structural heart interventions.

OBJECTIVES: Our objectives were to assess for differences between standard and radiofrequency (RF) needle in procedural times, success, and spatial accuracy. BACKGROUND: Targeted transseptal (TS) puncture is essential for structural heart interventions. Spatial accuracy of standard versus RF needle has not been reported. METHODS: Consecutive patients undergoing structural heart interventions requiring TS puncture were studied retrospectively. A standard needle was alternated with a RF needle. Procedural success and times were recorded. Measurements based on intraprocedural transesophageal echocardiograms of the intended versus final TS crossing site were obtained. Pre-puncture and maximal tenting of the septum were also recorded. RESULTS: Twenty-five patients underwent standard needle and 27 RF TS access. All RF needle attempts to cross were successful without an assistance wire. Three standard needle patients required assisted crossing. After failed TS access, two patients had successful RF TS access. TS procedural times significantly favored the RF needle for time from septum to puncture (P = 0.02). Both standard and RF access yielded accurate crossing with no significant differences between the intended and actual crossing site. Maximal tenting was significantly less with the RF needle (P = 0.004). There were no major complications. CONCLUSIONS: In the hands of an experienced operator, there were no major clinically significant differences between the standard and RF needle approaches. However, procedural unassisted crossing success was higher with the RF needle approach as compared to standard needle. Procedural times and degree of septum tenting favored the RF over standard needle. Accuracy was similar with both approaches. RF was a successful strategy when standard needle failed. There were no major complications with either TS puncture strategy. © 2016 Wiley Periodicals, Inc.