Role of endothelial glycocalyx in sliding friction at the catheter-blood vessel interface.

Catheterization is a common medical operation to diagnose and treat cardiovascular diseases. The blood vessel lumen is coated with endothelial glycocalyx layer (EGL), which is important for the permeability and diffusion through the blood vessels wall, blood hemodynamics and mechanotransduction. However EGL's role in catheter-blood vessel friction is not explored.

Laser-Plasma Spectroscopy of Hydroxyl with Applications.

This article discusses laser-induced laboratory-air plasma measurements and analysis of hydroxyl (OH) ultraviolet spectra. The computations of the OH spectra utilize line strength data that were developed previously and that are now communicated for the first time. The line strengths have been utilized extensively in interpretation of recorded molecular emission spectra and have been well-tested in laser-induced fluorescence applications for the purpose of temperature inferences from recorded data.

Laser-Plasma Spatiotemporal Cyanide Spectroscopy and Applications.

This article reports new measurements of laser-induced plasma hypersonic expansion measurements of diatomic molecular cyanide (CN). Focused, high-peak-power 1064 nm Q-switched radiation of the order of 1 TW/cm 2 generated optical breakdown plasma in a cell containing a 1:1 molar gas mixture of N 2 and CO 2 at a fixed pressure of 1.1 × 10 5 Pascal and in a 100 mL/min flow of the mixture.

Effect of preoperative pelvic floor muscle therapy with biofeedback versus standard care on stress urinary incontinence and quality of life in men undergoing laparoscopic radical prostatectomy: a randomised control trial.

Aims: Laparoscopic radical prostatectomy (LARP) may cause stress urinary incontinence (SUI). This study reports the effects of preoperative pelvic floor muscle therapy (PFMT) on SUI and quality of life (QoL) in men undergoing LARP.

Materials And Methods: In this single-center randomized controlled trial, 122 patients undergoing LARP were assigned to an intervention group of PFMT with biofeedback once a week preoperatively, with 4 weeks' follow-up or to a control group receiving standard care.

Optical diagnostic and therapy applications of femtosecond laser radiation using lens-axicon focusing.

Diagnostic modalities by means of optical and/or near infrared femtosecond radiation through biological media can in principle be adapted to therapeutic applications. Of specific interest are soft tissue diagnostics and subsequent therapy through hard tissue such as bone. Femto-second laser pulses are delivered to hydroxyapatite representing bone, and photo-acoustic spectroscopy is presented in order to identify the location of optical anomalies in an otherwise homogeneous medium.

Temperature distribution in dental tissue after interaction with femtosecond laser pulses.

Algebraic and numerical solutions are presented of the temperature rise in dental tissue due to interaction with ultrashort optical radiation. Results of the studies with femtosecond laser pulses show agreement between theory and experiment. A temperature rise of typically 5 K is found for a 40 millisecond train of 7 nJ, 70 fs laser pulses at a repetition rate of 80 MHz.

Validation of a brief quantitative measure of autistic traits: comparison of the social responsiveness scale with the autism diagnostic interview-revised.

Studies of the broader autism phenotype, and of subtle changes in autism symptoms over time, have been compromised by a lack of established quantitative assessment tools. The Social Responsiveness Scale (SRS-formerly known as the Social Reciprocity Scale) is a new instrument that can be completed by parents and/or teachers in 15-20 minutes. We compared the SRS with the Autism Diagnostic Interview-Revised (ADI-R) in 61 child psychiatric patients.

New perspectives on catheter-based ablation of ventricular tachycardia complicating Chagas' disease: experimental evidence of the efficacy of near infrared lasers for catheter ablation of Chagas' VT.

Chronic Chagas' myocarditis can alter the myocardial substrate in a way that facilitates the emergence of fatal VT in a way similar to the long-term consequences of myocardial infarction. Post-myocardial infarction and Chagas' VT share many similarities: they are both macroreentrant circuits, entrainable, involving any wall segment from the endocardium to the epicardium. However, as compared to patients with post-MI VT, Chagasic patients tend to be younger and have a higher left ventricular ejection fraction.

Quantifying spatial localization of optical mapping using Monte Carlo simulations.

Optical mapping techniques used to study spatial distributions of cardiac activity can be divided into two categories. 1) Broad-field excitation method, in which hearts stained with voltage or calcium sensitive dyes are illuminated with broad-field excitation light and fluorescence is collected by image or photodiode arrays. 2) Laser scanning method, in which illumination uses a scanning laser and fluorescence is collected with a photomultiplier tube.

Laser photoablation of experimental post-infarction ventricular tachycardia guided by three dimensional activation mapping.

Background And Objective: The purpose of this study was to evaluate the efficacy of epicardially delivered laser energy to ablate induced ventricular tachycardia in a post-infarction canine model.

Study Design/materials And Methods: In 13 canines, the left anterior wall myocardial infarction was created. Five days later, 240 plunged electrodes were inserted into the heart.

Myocardial temperatures during in vivo endocardial Nd:YAG laser irradiation.

To determine safety and efficacy of neodymium:YAG laser irradiation of the endocardium, temperatures at both the epicardium and the endocardium were recorded for thermal damage evaluation. A total of 48 coagulation lesions were created at power settings of 20 and 30 W in 20 open chest dogs by transcatheter endocardial laser irradiation. Tissue temperatures were monitored by epicardial thermography (Tepi), and by endocardial thermocouples at the catheter tip (Tprox) and 4 mm below the endocardial surface (Tdist).

Selective coagulation necrosis of canine adventitia and media induces extracellular matrix accumulation without neointima formation.

Endothelial cell injury, the disruption of the internal elastic membrane and medial damage represent important stimuli for the development of a neointima. It is unclear whether selective adventitial and medial injury also induce neointima formation. Incremental argon laser energies (11.

Myocardial temperature distribution under cw Nd:YAG laser irradiation in in vitro and in vivo situations: theory and experiment.

Tissue samples ranging from 2 to 16 mm in thickness were irradiated at 1064 nm with energies ranging from 40 to 2400 J. Coagulation lesions of in vitro and in vivo experiments were subjected to temperature profiling and submitted for histology. Irreversible damage was calculated with the damage integral formalism, following the bioheat equation solved with Monte Carlo computer light-distribution simulations.

Ultrasonic characterization of myocardial photocoagulation lesion size in vivo during Nd:YAG laser irradiation.

Endocardial coagulation lesions were created using transcatheter continuous-wave Nd:YAG laser irradiation. Ultrasound monitoring of thermal lesion dimensions was performed using 7.5-MHz and 10-MHz transducers directly from the epicardial surface in short-axis configuration (group A) or through the chest wall (group B).

Catheterization technique for laser photoablation of atrioventricular conduction from the aortic root in dogs.

A simple catheterization technique for producing suppression or block of atrioventricular (AV) conduction in dogs by neodymium:YAG (Nd:YAG) laser photocoagulation from the aortic root is described. In 14 canines, electrode catheters were percutaneously advanced to the high right atrium, to the His bundle area at the tricuspid valve (right His [RH]), and the noncoronary cusp of the aortic valve (left His [LH]). A 400 microns optical fiber was fed into the lumen of the LH catheter.

Selective elimination of retrograde conduction by intraoperative neodymium: YAG laser photocoagulation in dogs.

Objectives: The purpose of this study was to test the feasibility of selective elimination of ventriculoatrial (VA) conduction by limited laser photocoagulation of the atrioventricular (AV) node, and to analyze the histologic substrate of unidirectional retrograde block.

Background: Atrioventricular node reentry requires intact retrograde conduction.

Methods: Neodymium:yttrium-aluminum-garnet laser photocoagulation was performed during cardiopulmonary bypass through a right atriotomy in 15 dogs that had intact retrograde conduction before operation.

Neodymium:YAG contact laser photocoagulation of the in vivo canine epicardium: dosimetry, effects of various lasing modes, and histology.

Unlabelled: Neodymium:YAG laser photocoagulation (LPC) is an investigational technique for the treatment of drug-resistant postinfarction ventricular tachycardia that requires cardiopulmonary bypass and open heart surgery. The purpose of this experimental study was to evaluate the feasibility of contact epicardial LPC to reach subepicardial, deep myocardial, and subendocardial regions without ventriculotomy and to analyze the dose-response relationships of this new technology. In 24 open-chest, closed heart dogs, a total of 219 epicardial laser lesions were generated under sterile conditions.

Modification of atrioventricular node transmission properties by intraoperative neodymium-YAG laser photocoagulation in dogs.

The purpose of this study was to test the feasibility of neodymium-yttrium-aluminum-garnet (Nd-YAG) laser photocoagulation of the atrioventricular (AV) node to control the ventricular rate during rapid atrial rhythms without creating AV block. In 12 dogs on normothermic cardiopulmonary bypass, short laser pulses were delivered to an area between the coronary sinus orifice and the site of the most proximally recorded His deflection until second degree AV block occurred at a paced atrial rate of 200 beats/min. Long-term effects on AV node function were followed up for 3 months.

Optical properties of normal, diseased, and laser photocoagulated myocardium at the Nd: YAG wavelength.

Laser photocoagulation of the myocardium effectively destroys arrhythmogenic foci. The purpose of this study was 1) to compare the optical properties of canine myocardium before and after photocoagulation, 2) to compare the canine model with clinical cases by measuring the optical properties of human myocardium, and 3) to assess the optical properties of human myocardial scar and epicardial fat tissue. Measured optical properties were the absorption coefficient, mu a; scattering coefficient, mu s; and scattering anisotropy factor, g.

Influence of probe motion on laser probe temperature in circulating blood.

The purpose of this study was to evaluate the effect of probe motion on laser probe temperature in various blood flow conditions. Laser probe temperatures were measured in an in vitro blood circulation model consisting of 3.2 nm-diameter plastic tubes.

Electrophysiologic characteristics of manifest and latent retrograde conduction in dogs.

Atrioventricular (AV) nodal reentry requires intact retrograde ventriculoatrial (VA) conduction. The purpose of this study was to assess the contribution of various pacing and pharmacologic techniques to uncover VA conduction during apparent unidirectional VA block, and to evaluate the role of several biologic and electrophysiologic factors in concealment of retrograde conduction. Forty healthy dogs underwent catheter-electrophysiologic studies of AV and VA conduction.

In vitro optical properties of human and canine brain and urinary bladder tissues at 633 nm.

Absorption and scattering coefficients and scattering anisotropy factor are presented for human and canine cadaver tissues at the helium-neon wavelength (633 nm). Measurements were performed with an integrating sphere arrangement and analyzed with the diffusion approximation of the equation of radiative transfer adapted to Kubelka-Munk techniques.

Drinking water and cancer incidence in Iowa. III. Association of cancer with indices of contamination.

With data from the Iowa Cancer Registry, age-adjusted sex-specific cancer incidence rates for the years 1969-1981 were determined for towns with a population of 1,000-10,000 and a public water supply from a single stable ground source. These rates were related to levels of volatile organic compounds and metals found in the finished drinking water of these towns in the spring of 1979. Results showed association between 1,2 dichloroethane and cancers of the colon and rectum and between nickel and cancers of the bladder and lung.