A cross-sectional study to determine the role of iris fluorescein angiography in chronic diabetic patients before cataract surgery

BACKGROUND OF STUDY: Diabetic Iridopathy (DI) has long been known as the silent thief of vision as it is often overlooked in the background of obvious and common Diabetic Retinopathy (DR). The dense brown melanocytes seen in our population and lack of appropriate technology to study the pattern of flow of blood through the iris vasculature has lead to slit lamp examination of the iris as one of the sole clinical gateway for detecting abnormal iris vasculature. However, slit lamp confesses only the severe and obvious degrees of iris vasculature abnormalities many a times only at the penultimate stage of neovascular glaucoma. In our study, we try to re-establish the long forgotten role of Iris Fluorescein Angiography (IFA) in early detection of iris vasculature abnormalities and thus be of more help in predicting the retinal status (alterations in the blood retinal barrier) in diabetic patients with dense cataract precluding the direct fundus examination. In diabetic patients it is important that we establish what type of retinopathy is behind either cataract or other types of dioptric media opacities, because serious complications can develop in a patient operated on without this knowledge. AIM OF THE STUDY: 1) To determine the role of iris fluorescein angiogram in detecting iris vessel abnormalities in diabetic patients. 2) To compare the fluoroscopic changes seen in iris with stage of diabetic retinopathy in diabetic patients with mature cataract. METHODOLOGY: 50 patients with diabetes mellitus and mature cataract who were admitted in to the wards of Department of ophthalmology , GRH Madurai, between January and June 2017, satisfying the inclusion exclusion criteria and who obliged with written consent were taken up for this study. A detailed, complete ocular examination was made in all subjects for both eyes. After hypersensitivity test and under anaesthetist monitoring iris fluorescein angiogram was performed using standard model zeiss fundus camera with dual filter system and objective settings for anterior segment photography. Diabetic iridopathy and diabetic retinopathy was classified based on abbreviated modified Airlie House classification .Cataract extraction was performed by phaco emulsification and within 2 weeks from the date of IFA routine fundus colour photography was taken and wherever necessary Fundus Fluorescein Angiography (FFA) was performed. The observations made were recorded in the master chart and the data analysis was done with the help of computer by using Graphpad prism7software and mean , Standard deviation and ‘p’ value were calculated through Fisher's exact test , pearson correlation and p value of <0.05 was taken as significant. RESULTS: The prevalence of Diabetic iridopathy was 32% in our study. Fluorescein dye leakage (Age Related Dye leak) which was transient and trivial with no specific pattern along the pupillary border is considered physiological after 50 years of age and thus included in the grade 0 Diabetic iridopathy group. Some recognisable patterns of abnormal iris vasculature were observed viz. loops, bifurcations and sprouts. But such patterns showed no significant correlation to the severity of iridopathy nor were they specific for diabetic iridopathy. According to our study IFA is found to have a low sensitivity (15%) and excellent specificity (96.07%) in predicting absence or presence of lower grades of Diabetic Retinopathy. However, the sensitivity (67%) and specificity (100%) of IFA in predicting higher grades of NPDR is substantially high which thus reinforces its role in heralding the occurrence of proliferative DR well ahead of clinical fundus changes. The two-tailed p value was calculated with the Fisher's exact test with and was found to be 0.0416, thus being statistically significant. The coefficient of correlation is 0.6119 and the coefficient of determination being 0.3744. This means that the clinically seen correlation between the Diabetic Retinopathy and Iridopathy in our study is also statistically significant proving the usefulness of Iris Fluorescein Angiography in predicting DR again. Thus, iris fluorescein angiography yields valuable information on status of retinopathy and is a helpful basis for avoiding complications (like vitreous hemorrhage, retinal hemorrhage, iris bleed or hemorrhage at angle,uveitis, post operative rise in IOP) when scheduling eyes with dioptric media opacities for cataract surgery. CONCLUSION: Using iris angiography we were able to detect severe form of DR by staging the Diabetic Iridopathy - that is, those most likely to present major complications during and following surgery. Clinically, when iris neovascularisation is detected in an eye in which it is impossible to evaluate retinopathy because of opacity in the lens or other media, concomitant serious retinopathy must be presumed, and therefore great care must be taken in the management of the eye. Before cataract extraction or vitrectomy, either cryocoagulation, transscleral photocoagulation or intravitreal Anti VEGF must be seriously considered to destroy the non-perfused peripheral areas of the retina. Sometimes endophotocoagulation carried out in the course of pars plana vitrectomy, or photocoagulation done in the early post op can produce good results. Above all, iris fluorescein angiography being a valuable diagnostic, non-invasive procedure, also provides more information regarding integrity of blood retinal barrier even in an opaque media. Our study thus proves that iris fluorescein angiography is more sensitive, specific and precise than slit lamp examination in revealing iris vasculature abnormalities

Molecular and thermal studies of carbon fiber precursor polymers with low thermal-oxidative stabilization characteristics

In this investigation, terpolymers, copolymers, and homopolymer of acrylonitrile with dimethylaminopropyl acrylamide (DMAPA), itaconic acid (IA) viz., poly(acrylonitrile‐ran‐3‐dimethylaminopropyl acrylamide‐ran‐itaconic acid) [P(AN‐DMAPP‐IA)], poly(acrylonitrile‐co‐3, dimethylaminopropyl acrylamide) [P(AN‐DMAPP)] were synthesized with varying amounts of comonomers using solution polymerization process. The chemical structure, composition, bonding network were determined employing infrared, 1H and, 13‐carbon nuclear magnetic resonance spectroscopic techniques. Molecular characteristics of as‐synthesized polymers such as different kinds of average molecular weights, molecular weight distribution were estimated applying solution viscometry and size exclusion chromatography. The influence of comonomers (DMPAA, IA) on the thermal stabilization characteristics of acrylonitrile terpolymers in comparison with copolymers and homopolymers of acrylonitrile were studied using differential scanning calorimetry (DSC), hyphenated thermal techniques (thermal gravimetry coupled with differential thermal analyzer).The DSC curves of P(AN‐DMAPP‐IA) exhibit a distinct broader bimodal peaks with thermal exotherm initiating at as low as 165 °C, and followed by two peaks with temperature difference of 42 °C, releasing the evolved heat at a release rate of 0.7–0.11 J g−1s−1over 10 min as compared to 1.2, 7.5 J g−1s−1 in 4.5, 2 min as observed in P(AN‐DMAPP), polyacrylonitrile, respectively. The thermal stability of P(AN‐DMAPP‐IA) and P(AN‐DMAPP), as evidenced by TGA‐DTA was found to be higher than PAN homopolymers. Specific heat capacity measurements confirmed the DSC results. Bulk densities of P(AN‐DMAPP‐IA) were in the range 0.31–0.35 g/cc. These results confirm the low‐temperature stabilization characteristics and suitability of P(AN‐DMAPP‐IA) as low cost carbon fiber precursor polymer

Wind Integrated Thermal Unit Commitment Solution Using Grey Wolf Optimizer

The augment of ecological shield and the progressive exhaustion of traditional fossil energy sources have increased the interests in integrating renewable energy sources into existing power system. Wind power is becoming worldwide a significant component of the power generation portfolio. Profuse literature have been reported for the thermal Unit Commitment (UC) solution. In this work, the UC problem has been formulated by integrating wind power generators along with thermal power system. The Wind Generator Integrated UC (WGIUC) problem is more complex in nature, that necessitates a promising optimization tool. Hence, the modern bio-inspired algorithm namely, Grey Wolf Optimization (GWO) algorithm has been chosen as the main optimization tool and real coded scheme has been incorporated to handle the operational constraints. The standard test systems are used to validate the potential of the GWO algorithm. Moreover, the ramp rate limits are also included in the mathematical WGIUC formulation. The simulation results prove that the intended algorithm has the capability of obtaining economical resolutions with good solution quality

Study of antimicrobial resistance profile and efflux mediated drug resistance in clinical isolates of Pseudomonas aeruginosa detected by ethidium bromide-agar Cartwheel method

Background: Development of antibiotic resistance or multidrug resistance (MDR) is one of the major causes of treatment failure of bacterial infections and has rapidly evolved into a threat to global health care. Bacterial efflux pumps play a significant role in the development of antibiotic resistance. This study evaluates the prevalence of efflux pump- mediated drug resistance in clinical isolates of P. aeruginosa.Methods: Clinical isolates (n=100) of P. aeruginosa were collected from various clinical laboratories in Kerala and their efflux mediated drug resistance detected by the ethidium bromide (EB) agar Cartwheel method.Results: The EB agar cartwheel method of screening revealed efflux activity in 17% (n=17) strains. The efflux activity was revealed at a minimum concentration of EB at 0 mg/l. P. aeruginosa strains showed the highest activity up to a concentration of 2.5 mg/l.Conclusions: This study discusses the emergence of efflux pump- mediated drug resistance in P. aeruginosa from various clinical samples. Our results showed that 17% drug resistance in P. aeruginosa is attributable to efflux related mechanisms.

Convective thundercloud development over the western ghats mountain slope in Kerala

Studies were carried out on the data from Braemore mountain observatory (lat. 8°45'N, long. 77°5'E) using a single-lens ceilometer (LIDAR), an electric field mill and a portable automatic weather station throughout the year 2010. The simultaneous data collected using the above instruments indicate the existence of strong updrafts followed by the formation of thunderclouds, a characteristic of the mountain slopes, during the thunderstorm months. Changes in atmosphere related to condensation and formation of water droplets during updraft events on the mountain slope could be detected from the ceilometer scattering data. Results of the study point to the cause of relatively more thunderstorm activity in that zone. This seems to be due to excessive updraft, which is strongly related to lightning activity in the region

Development of three dimensional constitutive theories based on lower dimensional experimental data

Most three dimensional constitutive relations that have been developed to describe the behavior of bodies are correlated against one dimensional and two dimensional experiments. What is usually lost sight of is the fact that infinity of such three dimensional models may be able to explain these experiments that are lower dimensional. Recently, the notion of maximization of the rate of entropy production has been used to obtain constitutive relations based on the choice of the stored energy and rate of entropy production, etc. In this paper we show different choices for the manner in which the body stores energy and dissipates energy and satisfies the requirement of maximization of the rate of entropy production that leads to many three dimensional models. All of these models, in one dimension, reduce to the model proposed by Burgers to describe the viscoelastic behavior of bodies.Comment: 23 pages, 6 figure

Network-Based Prediction and Analysis of HIV Dependency Factors

HIV Dependency Factors (HDFs) are a class of human proteins that are essential for HIV replication, but are not lethal to the host cell when silenced. Three previous genome-wide RNAi experiments identified HDF sets with little overlap. We combine data from these three studies with a human protein interaction network to predict new HDFs, using an intuitive algorithm called SinkSource and four other algorithms published in the literature. Our algorithm achieves high precision and recall upon cross validation, as do the other methods. A number of HDFs that we predict are known to interact with HIV proteins. They belong to multiple protein complexes and biological processes that are known to be manipulated by HIV. We also demonstrate that many predicted HDF genes show significantly different programs of expression in early response to SIV infection in two non-human primate species that differ in AIDS progression. Our results suggest that many HDFs are yet to be discovered and that they have potential value as prognostic markers to determine pathological outcome and the likelihood of AIDS development. More generally, if multiple genome-wide gene-level studies have been performed at independent labs to study the same biological system or phenomenon, our methodology is applicable to interpret these studies simultaneously in the context of molecular interaction networks and to ask if they reinforce or contradict each other

Micropropagation and conservation of selected endangered anticancer medicinal plants from the Western Ghats of India

Globally, cancer is a constant battle which severely affects the human population. The major limitations of the anticancer drugs are the deleterious side effects on the quality of life. Plants play a vital role in curing many diseases with minimal or no side effects. Phytocompounds derived from various medicinal plants serve as the best source of drugs to treat cancer. The global demand for phytomedicines is mostly reached by the medicinal herbs from the tropical nations of the world even though many plant species are threatened with extinction. India is one of the mega diverse countries of the world due to its ecological habitats, latitudinal variation, and diverse climatic range. Western Ghats of India is one of the most important depositories of endemic herbs. It is found along the stretch of south western part of India and constitutes rain forest with more than 4000 diverse medicinal plant species. In recent times, many of these therapeutically valued herbs have become endangered and are being included under the red-listed plant category in this region. Due to a sharp rise in the demand for plant-based products, this rich collection is diminishing at an alarming rate that eventually triggered dangerous to biodiversity. Thus, conservation of the endangered medicinal plants has become a matter of importance. The conservation by using only in situ approaches may not be sufficient enough to safeguard such a huge bio-resource of endangered medicinal plants. Hence, the use of biotechnological methods would be vital to complement the ex vitro protection programs and help to reestablish endangered plant species. In this backdrop, the key tools of biotechnology that could assist plant conservation were developed in terms of in vitro regeneration, seed banking, DNA storage, pollen storage, germplasm storage, gene bank (field gene banking), tissue bank, and cryopreservation. In this chapter, an attempt has been made to critically review major endangered medicinal plants that possess anticancer compounds and their conservation aspects by integrating various biotechnological tool