Combined Laser and Intravitreal Triamcinolone for Proliferative Diabetic Retinopathy and Macular Edema: One-year Results of a Randomized Clinical Trial

PURPOSE: To evaluate laser combined with intravitreal triamcinolone acetonide (IVTA) for the management of patients with proliferative diabetic retinopathy (PDR) and clinically significant macular edema (CSME). DESIGN: Randomized clinical trial. METHODS: SETTINGS: Single center. STUDY POPULATION: Twenty-two patients with bilateral treatment,naive moderate PDR and CSME. INTERVENTION: Laser (panretinal and macular) photocoagulation was performed in each eye, followed by IVTA in one randomly assigned eye. Best,corrected visual acuity (BCVA), fundus photography, and optical coherence tomography were performed at baseline and at months 1, 3, 6, 9, and 12. MAIN OUTCOME MEASURES:. Changes in BCVA, central macular thickness (CMT), and total macular volume (TMV). RESULTS: The mean logarithm of the minimal angle of resolution (logMAR) BCVA improved significantly, and mean CMT and TMV were significantly reduced in the IVTA group compared with the laser,only group (controls) at all study follow-up visits (P < .001). The mean logMAR BCVA (Snellen equivalent) was 0.44 (20/50(-2)) for the IVTA group and 0.38 (20/50(+1)) for the controls at baseline, and 0.12 (20/25(-1)) for the IVTA group and 0.32 (20/40(-1)) for the controls at 12 months (P < .001.). The mean CMT and TMV were, respectively, 360 mu m and 8.59 mm(3) for the IVTA group and 331 mu m and 8.44 mm(3) for the controls at baseline, and 236 mu m and 7.32 mm(3) for the IVTA group and 266 mu m and 7.78 mm(3) for the controls at 12 months (P < .001). CONCLUSIONS: The combination of laser photocoagulation with IVTA was associated with improved BCVA and decreased CMT and TMV when compared with laser photocoagulation alone for the treatment of moderate PDR with CSME. (Am J Ophthalmol 2009;147:291-297. (C) 2009 by Elsevier Inc. All rights reserved.)

Left Atrial Function After Ablation for Paroxysmal Atrial Fibrillation

Radiofirequency ablation of the pulmonary veins has been used to treat patients with paroxysmal atrial fibrillation (AF), and atrial damage after ablation is an issue of concern. To evaluate left atrial function shortly and midterm after ablation, 33 consecutive patients with paroxysmal AF were studied at baseline, 24 hours, and >= 6 months after ablation. Patients in sinus rhythm with normal ventricular function were included in the study. Echocardiographic measurements of left atrial volumes (Simpson`s rule) and transmitral and tissue Doppler myocardial (A`) velocities at the septal and lateral mitral annulus were undertaken at each time. Left atrial emptying fraction (EF; maximal - minimal left atrial volume/maximal left atrial volume) was used to express left atrial function. After 8 +/- 2 months, 30 of 33 patients returned (23 men, age 53 +/- 13 years), and all except 2 were in sinus rhythm. Shortly after ablation, left atrial minimal volumes increased (from 30 +/- 15 to 35 +/- 15 ml; p = 0.02), with maximal volumes unchanged, resulting in decreased left atrial EF (from 47 +/- 8 to 40 +/- 7 ml; p <0.05). Tissue Doppler septal A` velocities also decreased (from 8.2 +/- 1.8 to 6.9 +/- 2.0 cm/s; p <0.05). However, after midterm follow-up, both left atrial EF and septal A` velocities had slightly increased compared with shortly after ablation, although left atrial volumes remained similar to baseline. Septal A` velocity changes paralleled left atrial EF both shortly (r = 0.46, p = 0.02) and at midterm after ablation (r = 0.47, p = 0.01). In conclusion, after radiofrequency ablation, patients with paroxysmal AF experienced an initial impairment in atrial function, with improvement at longer term follow-up. (C) 2009 Elsevier Inc. All rights reserved. (Am J Cardiol 2009;103: 395-398)

Gastric hypomotility following epicardial vagal denervation ablation to treat atrial fibrillation

Gastric Palsy Following AF Vagal Ablation. We report a case of a 55-year-old man with vagal paroxysmal atrial fibrillation (AF) who was submitted to selective epicardial and endocardial atrial vagal denervation with the objective of treating AF. Radiofrequency pulses were applied on epicardial and endocardial surface of the left atrium close to right pulmonary veins (PVs) and also on epicardial surface close to left inferior PV. Following the procedure, patient presented with symptoms of gastroparesis, which was documented on CT scan and gastric emptying scintigraphy. Symptoms were transient and the patient recovered completely.

Atrial Coronary Arteries in Areas Involved in Atrial Fibrillation Catheter Ablation

Background-The proximity to vascular structures is a limiting factor during radiofrequency ablation. However, little or no attention has been given to the atrial arterial circulation during the development of atrial fibrillation (AF) catheter ablation techniques. Methods and Results-We examined the atrial arterial circulation in areas involved in AF ablation in 24 heart specimens by colored resin injection and careful dissection. The sinus node artery (SNA) arose from the circumflex artery in 42% of case; proximal to the LA appendage in 29%, crossing the left atrium (LA) anterior wall; and after the LA appendage in the remaining 13%, crossing the mitral isthmus and passing close to the left pulmonary veins (PVs), the LA roof, and the right superior PV. In 58%, the SNA arose from the right coronary artery. Major arteries (>= 1 mm in external diameter) were found in the mitral isthmus in 54%, at the LA roof in 54%, and at the LA anterior wall in 29%. Around the left PV ostia, there were areas with major arteries in up to 37% (at the roof and inferior segments) and around the right PV ostia in up to 29% (at the roof segment). Conclusions-Major atrial coronary arteries, including the SNA, were commonly found in the areas involved in AF ablation and could cause difficulties in obtaining transmural lesions and electric isolation or even lead to ischemic sinus node or atrial dysfunction. (Circ Arrhythm Electrophysiol. 2010;3:600-605.)

Supersonic velocimetry in a shock tube using laser enhanced ionisation and planar laser induced fluorescence

A novel flow-tagging technique is presented which was employed to measure gas velocities in the free stream of a shock tube. This method is based on the laser spectroscopic techniques of Laser-Enhanced Ionisation (LEI) and Laser-Induced Fluorescence (LIF). The flow in the shock tube is seeded with small amounts of sodium, and LEI is used to produce a substantial depletion of neutral sodium atom concentration in a well-defined region of the flow, by using two wavelength-resonance excitation and subsequent collisional ionisation. At a specific time delay, single-laser-pulse planar LIF is utilised to produce a two-dimensional (2-D) inverse image of the depleted tagged region downstream of the flow. By measuring the displacement of the tagged region, free stream velocities in a shock tube were determined. Large variations in the concentration of sodium seeded into the flow were observed and even in the presence of these large variations accurate free-stream velocity measurements were obtained. The experimentally determined value for velocity compares very well with the predicted velocity.

Effect of phototherapy with low intensity laser on local and systemic immunomodulation following focal brain damage in rat

Brain injury is responsible for significant morbidity and mortality in trauma patients, but controversy still exists over therapeutic management for these patients. The objective of this study was to analyze the effect of phototherapy with low intensity lasers on local and systemic immunomodulation following cryogenic brain injury. Laser phototherapy was applied (or not-controls) immediately after cryogenic brain injury performed in 51 adult male Wistar rats. The animals were irradiated twice (3 h interval), with continuous diode laser (gallium-aluminum-arsenide (GaAlAs), 780 nm, or indium-gallium-aluminum-phosphide (InGaAlP), 660 nm) in two points and contact mode, 40 mW, spot size 0.042 cm(2), 3 J/cm(2) and 5 J/cm(2) (3 s and 5 s, respectively). The experimental groups were: Control (non-irradiated), RL3 (visible red laser/ 3 J/cm(2)), RL5 (visible red laser/5 J/cm(2)), IRL3 (infrared laser/ 3 J/cm(2)), IRL5 (infrared laser/5 J/cm(2)). The production of interleukin-1IL-1 beta (IL-1 beta), interleukin6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-alpha) was analyzed by enzyme immunoassay technique (ELISA) test in brain and blood samples. The IL-1 beta concentration in brain of the control group ;was significantly reduced in 24 h (p < 0.01). This reduction was also observed in the RL5 and IRL3 groups. The TNF-alpha and IL-6 concentrations increased significantly (p < 0.01 and p < 0.05, respectively) in the blood of all groups, except by the IRL3 group. The IL-6 levels in RL3 group were significantly smaller than in control group in both experimental times. IL-10 concentration was maintained stable in all groups in brain and blood. Under the conditions of this study, it is possible to conclude that the laser phototherapy can affect TNF-alpha, IL-1 beta and IL-6 levels in the brain and in circulation in the first 24 h following cryogenic brain injury. (C) 2009 Elsevier B.V. All rights reserved.

Measurements of neutral atom diffusion and electron-ion recombination by laser enhanced ionisation and planar laser induced fluorescence in an air-acetylene flame

The spatial and temporal evolution of a depleted atomic distribution created by laser enhanced ionisation (LEI) was employed to determine both a diffusion coefficient for sodium (Na) and an electron (e(-)) and sodium ion recombination rate coefficient in an analytical air-C2H2 flame. A depleted distribution of neutral sodium atoms was produced in a flame by ionising approximately 80% of the irradiated sodium atoms in a well defined region using a two step LEI excitation scheme. Following depletion by ionisation, planar laser induced fluorescence (PLIF) images of the depleted region recorded the diffusion and decay of the depleted Na distribution for different depletion-probe delays. From measurements of the diffused width of the distribution, an accurate diffusion coefficient D = (1.19 +/- 0.03) x 10(-3) m(2) s(-1) for Na was determined in teh burnt gases of the flame. Measurements of the integrated fluorescence intensity in the depleted region for different depletion-probe delays were related to an increase in atomic sodium concentration caused by electron-ion recombination. At high concentrations (greater than or equal to 50 mu g ml(-1)), where the electron and ion concentrations in the depleted region were assumed equal, a recombination rate coefficient of 4.2 x 10(-9) cm(3) s(-1) was calculated. (C) 1997 Elsevier Science B.V.

Low-Level Laser Therapy in Chronic Autoimmune Thyroiditis: A Pilot Study

Background and Objectives: Chronic autoimmune thyroiditis (CAT) remains the most common cause of acquired hypothyroidism There is currently no therapy that is capable of regenerating CAT-damaged thyroid tissue The objective of this study was to gauge the value of applying low-level laser therapy (LLLT) in CAT patients based on both ultrasound studies (USs) and evaluations of thyroid function and thyroid autoantibodies. Study Design/Materials and Methods: Fifteen patients who had hypothyroidism caused by CAT and were undergoing levothyroxine (LT4) treatment were selected to participate in the study Patients received 10 applications of LLLT (830 nm, output power 50 mW) in continuous mode, twice a week, using either the punctual technique (8 patients) or the sweep technique (7 patients), with fluence in the range of 38-108 J/cm(2) USs were performed prior to and 30 days after LLLT USs included a quantitative analysis of echogenicity through a gray-scale computerized histogram index (El). Following the second ultrasound (30 days after LLLT), LT4 was discontinued in all patients and, if required, reintroduced Truodothyronine, thyroxine (T4), free T4, thyrotropin, thyroid peroxidase (TPOAb) and thyroglobulin (TgAb) antibodies levels were assessed before LLLT and then 1, 2, 3, 6, and 9 months after LT4 withdrawal. Results: We noted all patients` reduced LT4 dosage needs, including 7 (47%) who did not require any LT4 through the 9-month follow-up The LT4 dosage used pre-LLLT (96 +/- 22 mu g/day) decreased in the 9th month of follow-up (38 23 mu g/day; P<0.0001) TPOAb levels also decreased (pre-LLLT = 982 +/- 530 U/ml, post-LLLT = 579 454 U/ml, P = 0 016) TgAb levels were not reduced, though we did observe a post-LLLT increase in the EI (pre-LLLT = 0 99 +/- 0.09, post-LLLT= 1.21 +/- 0.19, P=0.001) Conclusion: The preliminary results indicate that LLLT promotes the improvement of thyroid function, as patients experienced a decreased need for LT4, a reduction in TPOAb levels, and an increase in parenchymal echogenicity Lasers Surg. Med. 42:589-596, 2010. (C) 2010 Wiley-Liss, Inc

Prion protein ablation increases cellular aggregation and embolization contributing to mechanisms of metastasis

Cellular Prion Protein (PrP(C)) is a cell surface protein highly expressed in the nervous system, and to a lesser extent in other tissues. PrP(C) binds to the extracellular matrix laminin and vitronectin, to mediate cell adhesion and differentiation. Herein, we investigate how PrP(C) expression modulates the aggressiveness of transformed cells. Mesenchymal embryonic cells (MEC) from wildtype (Prnp(+/+)) and PrP(C)-null (Prnp(0/0)) mice were immortalized and transformed by co-expression of ras and myc. These cells presented similar growth rates and tumor formation in vivo. When injected in the tail vein, PrnP(0/0)raS/myc cells exhibited increased lung colonization compared with Prnp(+/+)ras/myc cells. Additionally, Prnp(0/0)ras/myc cells form more aggregates with blood components than Prnp(+/+)ras/myc cells, facilitating the arrest of Prnp(0/0)ras/myc cells in the lung vasculature. Integrin alpha(v)beta(3) is more expressed and activated in MEC and in transformed Prnp(0/0) cells than in the respective Prnp(+/+) cells. The blocking of integrin alpha(v)beta(3) by RGD peptide reduces lung colonization in transformed Prnp(0/0) cells to similar levels of those presented by transformed Prnp(+/+) cells. Our data indicate that PrP(C) negatively modulates the expression and activation of integrin alpha(v)beta(3) resulting in a more aggressive phenotype. These results indicate that PrP(C) may have main implications in modulating metastasis formation. (C) 2009 UICC

Antiphase dynamics of a chaotic multimode laser

Antiphase dynamics of an optically pumped NH3 bidirectional ring laser under the chaotic, phase-sensitive mode coupling is experimentally observed. Our experimental result suggests strongly that the dynamics is a generic behavior of the laser.

Metastable chaos in the ammonia ring laser

We report experimental studies of metastable chaos in the far-infrared ammonia ring: laser. When the laser pump power is switched from above chaos threshold to slightly below, chaotic intensity pulsations continue for a varying time afterward before decaying to either periodic or cw emission. The behavior is in good qualitative agreement with that predicted by the Lorenz equations, previously used to describe this laser. The statistical distribution of the duration of the chaotic transient is measured and shown to be in excellent agreement with the Lorenz equations in showing a modified exponential distribution. We also give a brief numerical analysis and graphical visualization of the Lorenz equations in phase space illustrating the boundary between the metastable chaotic and the stable fixed point basins of attraction. This provides an intuitive understanding of the metastable dynamics of the Lorenz equations and the experimental system.

Homoclinic orbits and chaos in a multimode laser

We show experimentally that under certain conditions the chaotic intensity dynamics of an optically pumped NH3 bidirectional ring laser could be well described in terms of Shil'nikov homoclinic orbits and chaos. We found that the mechanism that resulted in this kind of dynamics of the laser is the competition between effects caused by the mode interaction between the forward and the backward modes of the laser and by the intrinsic single-mode dynamics of the interacting modes. (C) 1997 Optical Society of America.

A method to immunolabel rodent spinal cord neurons and glia for molecular study in specific laser microdissected cells involved in neurodegenerative disorders

Neuron-glia interaction is involved in physiological function of neurons, however, recent evidences have suggested glial cells as participants in neurotoxic and neurotrophic mechanisms of neurodegenerative/neuroregenerative processes. Laser microdissection offers a unique opportunity to study molecular regulation in specific immunolabeled cell types. However, an adequate protocol to allow morphological and molecular analysis of rodent spinal cord astrocyte, microglia and motoneurons remains a big challenge. In this paper we present a quick method to immunolabel those cells in flash frozen sections to be used in molecular biology analyses after laser microdissection and pressure catapulting.

Long-Term Astroglial Reaction and Neuronal Plasticity in the Subcortical Visual Pathways After a Complete Ablation of Telencephalon in Pigeons (Columba livia)

This paper analyzes the astroglial and neuronal responses in subtelencephalic structures, following a bilateral ablation of the telencephalon in the Columba livia pigeons. Control birds received a sham operation. Four months later the birds were sacrificed and their brains processed for glial fribillary acid protein (GFAP) and neurofilament immunohistochemistry, markers for astrocytes and neurons, respectively. Computer-assisted image analysis was employed for quantification of the immunoreactive labeling in the nucleus rotundus (N.Rt) and the optic tectum (OT) of the birds. An increased number of GFAP immunoreactive astrocytes were found in several subregions of the N.Rt (p .001), as well as in layers 1, 2cd, 3, and 6 of the OT (p .001) of the lesioned animals. Neurofilament immunoreactivity decreased massively in the entire N.Rt of the lesioned birds; however, remaining neurons with healthy aspect showing large cytoplasm and ramified branches were detected mainly in the periphery of the nucleus. In view of the recently described paracrine neurotrophic properties of the activated astrocytes, the data of the present study may suggest a long-lasting neuroglial interaction in regions of the lesioned bird brain far from injury. Such events may trigger neuronal plasticity in remaining brain structures that may lead spontaneous behavior recovery as the one promoted here even after a massive injury.