28 research outputs found

    Improved subjective symptoms of conjunctivochalasis using bipolar diathermy method for conjunctival shrinkage

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    Tomoyuki Kashima1,2, Hideo Akiyama1, Fumihide Miura2, Shoji Kishi11Department of Ophthalmology, Gunma University School of Medicine, Gunma, Japan; 2Department of Ophthalmology, Saku Central Hospital, Nagano, JapanPurpose: To evaluate the improvement in subjective symptoms of conjunctivochalasis after bipolar coagulation.Methods: Forty-three eyes of 26 patients (average age, 75.7 ± 8.4 years) were included in this study. The inferior conjunctivas were cauterized between April 2009 and June 2010. Surgery involved pinching the excess conjunctiva and performing bipolar cauterization after subconjunctival injection of a local anesthetic agent. Patients were asked to describe the postoperative foreign-body sensation and change in subjective symptoms 1 month postoperatively, with the preoperative symptom score defined as 10.Results: Twenty-two patients (84.6%) reported symptom relief immediately after the procedure, though all patients had a mild gritty sensation for 1–2 weeks postoperatively. The mean postoperative symptom score obtained from the questionnaire was 3.27 ± 3.31, which was significantly lower than the preoperative score (P < 0.0001). No patients had experienced recurrent symptoms at the end of the follow-up period.Conclusion: Thermal cauterization can achieve conjunctival shrinkage and adherence to the subconjunctival tissues. Operation time is only a few minutes, postoperative pain is not severe, and the procedure can be performed in an outpatient clinic, all of which represent benefits to the patients.Keywords: coagulation, cauterization, conjunctival injection&nbsp

    Effect of Template Type on the Trametes versicolor Laccase-Catalyzed Oligomerization of the Aniline Dimer p-Aminodiphenylamine (PADPA)

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    Many previous studies have shown that (i) the oxidation of aniline or the aniline dimer p-aminodiphenyl-amine (PADPA) in a slightly acidic aqueous solution can be catalyzed with heme peroxidases or multicopper laccases and that (ii) subsequent reactions lead to oligomeric or polymeric products, which resemble chemically synthesized polyaniline in its conductive emeraldine salt form (PANI-ES), provided that (iii) an anionic "template" is present in the reaction medium. Good templates are anionic polyelectrolytes, micelles, or vesicles. Under optimal conditions, their presence directs the reactions in a positive way toward the desired formation of PANI-ES-type products. The effect of four different types of anionic templates on the formation of PANI-ES-like products from PADPA was investigated and compared by using Trametes versicolor laccase (TvL) as a catalyst in an aqueous pH 3.5 solution at room temperature. All four templates contain sulfonate groups: the sodium salt of the polyelectrolyte sulfonated polystyrene (SPS), micelles from sodium dodecylbenzenesulfonate (SDBS), vesicles from a 1:1 molar mixture of SDBS and decanoic acid, and vesicles from sodium bis(2-ethylhexyl) sulfosuccinate (AOT). Although with all four templates, stable, inkjet-printable solutions or suspensions consisting of PANI-ES-type products were obtained under optimized conditions, considerably higher amounts of TvL were required with SDBS micelles to achieve comparable monomer conversion to PANI-ES-like products during the same time period when compared to those with SPS or the two types of vesicles. This makes SDBS micelles less attractive as templates for the investigated reaction. In situ UV/vis/near-infrared, electron paramagnetic resonance (EPR), and Raman spectroscopy measurements in combination with an high-performance liquid chromatography analysis of extracted reaction products, which were deprotonated and chemically reduced, showed seemingly small but significant differences in the composition of the mixtures obtained when reaching reaction equilibrium after 24 h. With the two vesicle systems, the content of unwanted substituted phenazine units was lower than in the case of SPS polyelectrolyte and SDBS micelles. The EPR spectra indicate a more localized, narrower distribution of electronic states of the paramagnetic centers of the PANI-ES-type products synthesized in the presence of the two vesicle systems when compared to that of the similar products obtained with the SPS polyelectrolyte and SDBS micelles as templates. Overall, the data obtained from the different complementary methods indicate that with the two vesicle systems structurally more uniform (regular) PANI-ES-type products formed. Among the two investigated vesicle systems, for the investigated reaction (oxidation of PADPA with TvL and O-2), AOT appears a somewhat better choice as it leads to a higher content of the PANI-ES polaron form

    How experimental details matter. The case of a laccase-catalysed oligomerisation reaction

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    The Trametes versicolor laccase (TvL)-catalysed oligomerisation of the aniline dimer p-aminodiphenylamine (PADPA) was investigated in an aqueous medium of pH = 3.5, containing 80-100 nm-sized anionic vesicles formed from AOT, the sodium salt of bis(2-ethylhexyl)sulfosuccinic acid. If run under optimal conditions, the reaction yields oligomeric products which resemble the emeraldine salt form of polyaniline (PANI-ES) in its polaron state, known to be the only oxidation state of linear PANI which is electrically conductive. The vesicles serve as "templates" for obtaining products with the desired PANI-ES-like features. For this complex, heterogeneous, vesicle-assisted, and enzyme-mediated reaction, in which dissolved dioxygen also takes part as a re-oxidant for TvL, small changes in the composition of the reaction mixture can have significant effects. Initial conditions may not only affect the kinetics of the reaction, but also the outcome, i.e., the product distribution once the reaction reaches its equilibrium state. While a change in the reaction temperature from T approximate to 25 to 5 degrees C mainly influenced the rate of reaction, increase in enzyme concentration and the presence of millimolar concentrations of chloride ions were found to have significant undesired effects on the outcome of the reaction. Chloride ions, which may originate from the preparation of the pH = 3.5 solution, inhibit TvL, such that higher TvL concentrations are required than without chloride to yield the same product distribution for the same reaction runtime as in the absence of chloride. With TvL concentrations much higher than the elaborated value, the products obtained clearly were different and over-oxidised. Thus, a change in the activity of the enzyme was found to have influence not only on kinetics but also led to a change in the final product distribution, molecular structure and electrical properties, which was a surprising find. The complementary analytical methods which we used in this work were in situ UV/vis/NIR, EPR, and Raman spectroscopy measurements, in combination with a detailed ex situ HPLC analysis and molecular dynamics simulations. With the results obtained, we would like to recall the often neglected or ignored fact that it is important to describe and pay attention to the experimental details, since this matters for being able to perform experiments in a reproducible way

    Evaluation of Fundus Blood Flow in Normal Individuals and Patients with Internal Carotid Artery Obstruction Using Laser Speckle Flowgraphy

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    <div><p>Purpose</p><p>We investigated whether laser speckle flowgraphy (LSFG) results are comparable in both eyes and whether it is useful in the diagnosis of disparity in ocular ischemic syndrome (OIS) patients.</p><p>Methods</p><p>We compared the mean blur rate (MBR) value for various fundus regions in both eyes of 41 healthy subjects and 15 internal carotid artery occlusion (ICAO) cases. We calculated the standard value of the Laterality Index (LI), which was the MBR comparison of both eyes in each of the regions, in the control subjects. We then investigated the correlation between both eyes for the LIs in the entire fundus, the degree of ICAO and visual function.</p><p>Results</p><p>The disparity of the LIs in both eyes was least in the entire area of the fundus in control subjects and there was a significant correlation between both eyes of the 41 healthy individuals (P = 0.019). Significant correlations were found for the LI, visual acuity and degree of ICAO. The specificity and sensitivity of LI in the entire area was 93.8% and 100%, respectively.</p><p>Conclusions</p><p>LSFG revealed normal individuals have symmetrical fundus blood flow. LSFG could detect OIS and might be a useful tool for detecting disparities in fundus blood flow.</p></div

    Case 1. The false color maps of a patient with ocular ischemic syndrome.

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    <p>Top, right eye; bottom, left eye. Although the color map of the right eye is normal, that of the left eye shows that the choroidal vasculature has disappeared and that there are faint retinal vessels present, suggesting decreased retinal and choroidal blood flows.</p
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