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Made available in DSpace on 2020-12-10T20:12:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-01 Background: This in vivo study assessed and compared the effectiveness of an aqueous indocyanine green (ICG) formulation (R-ICG) and a lipid ICG formulation (L-ICG) in occluding the rabbit choriocapillaris, and determined the singlet oxygen quantum yields and aggregation properties of both formulations in vitro. Methods: Singlet oxygen production and aggregation were compared. The eye fundus of 30 albino rabbits was irradiated 0-15 min after dye injection using an 810 nm diode laser. Fluorescein angiography and light microscopy were used to evaluate the safety and efficacy of R-ICG and L-ICG. Results: L-ICG decreased the dimerisation constant and the tendency of ICG to form aggregates, and increased the efficiency of ICG in generating singlet oxygen (R-ICG, Phi Delta= 0.120 and L-ICG, Phi Delta= 0.210). Using a 10 mg/kg dose, choriocapillaris occlusion was achieved at a light dose of 35.8 J/cm(2) with L-ICG and 71.6 J/cm(2) with R-ICG with minimal damage to the neurosensory retina. Conclusion: Restrictions to the use of ICG in aqueous solution, low singlet oxygen quantum yields and high aggregation tendency, were overcome with L-ICG. The lower laser irradiance required to obtain choriocapillaris occlusion may suggest that L-ICG is a more potent and selective photosensitiser than R-ICG. Hosp Olhos Araraquara, Retinal Diagnost & Treatment Div, BR-14802530 Araraquara, SP, Brazil Univ Fed Sao Paulo, Paulista Sch Med, Dept Ophthalmol, Sao Paulo, Brazil State Univ Sao Paulo USP Ribeirao Preto, Dept Chem, Riberir Preto, Brazil Univ Calif Irvine, Dept Ophthalmol, Irvine, CA USA State Univ Sao Paulo USP Ribeirao Preto, Dept Chem, Riberir Preto, Brazil

Background/aims: To determine the potential of an intravitreal sustained release naproxen and 5-fluorouracil (NA/5-FU) codrug for the treatment of experimental proliferative vitreoretinopathy (PVR) in a model for trauma associated tractional retinal detachment (TRD). Methods: Sustained release pellets were prepared by covalently linking naproxen to 5-fluorouracil. Drug release was tested in vitro and toxic effects were evaluated by electroretinography and light microscopy. Traumatic PVR was induced in pigmented rabbits by performing a scleral laceration, followed by repair and intravitreal injection of 0.4 ml of autologous blood. Thirty six eyes were treated with a sustained release implant containing 1.5 mg NA/5-FU as a codrug and 36 control eyes were submitted to surgery alone. Eyes were evaluated for TRD by serial indirect ophthalmoscope examination at different time points followed by postmortem fundus evaluation of the enucleated eye Results: The NA/5-FU pellets were found to provide linear release of 5-FU and naproxen over the 30 day duration of the in vitro release test. Both the severity of PVR grade and the percentage of eyes with moderate or worse tractional detachment were significantly lower in eyes treated with the codrug pellet. There were no drug related toxic effects evident on histopathological or electroretinograph examination of eyes containing the NA/5-FU pellet. Conclusions: The results suggest that this NA/5-FU codrug device effectively inhibits the progression of PVR in a rabbit trauma model that closely resembles PVR in humans. Additional studies to add knowledge to these initial findings and to clarify the potential of the codrug device for the treatment of human PVR are warranted.

Ventricular arrhythmias (VAS), Including ventricular tachycardia (VT), ventricular fibrillation (VF) and Brady-arrhythmias, are life-threatening complications of acute myocardial infarction (MI). Objective: To study the incidence of ventricular arrhythmias, brady-arrhythmias and Sudden Cardiac Death (SCD) in Sudanese patients with acute MI. Methodology: This is a prospective cross sectional, hospital based study, conducted at Elshaab Teaching Hospital Khartoum Sudan. One Hundred Sudanese patients with acute MI were enrolled in the study in the period between August 2006 and December 2006. A questionnaire was constructed in sections to address the different aspect of the study group. ECG Monitor was used to confirm the complication in every patient. Result:Of the study group forty seven (47%) patients were 55-65 years old, twenty eight (28%) were more than 65 years old and twenty five (25%) were less than 55 years old. Sixty nine (69%) were males. Twenty patients (20%) developed complications [ventricular arrhythmias (VAS), Brady-arrhythmias and SCD]. Conclusion: The incidence of ventricular arrhythmias, brady-arrhythmias and sudden cardiac death following acute myocardial infarction were significantly high in Sudanese patients. The increased incidence is even in all age groups. DM, smoking and past history of IHD are the commonest associated risk factors. Thrombolysis is under used and had no significant impact. Keywords : thrombolysis, fibrillation, ischemia, Dyslipidaemia Sudan Journal of Medical Science Vol. 3 (4) 2008: pp. 325-332

Purpose To investigate the in vitro pH, osmolarity, spectral, and photostability properties of nine vital dyes for vitreoretinal surgery. Methods Nine dyes-indocyanine green (ICG), trypan blue (TB), brilliant blue (BriB), bromophenol blue (BroB), Congo red (CR), light green (LG), fast green (FG), indigo carmine (IC) and Evans blue (EB)-diluted in three solvents (saline solution, glucose 5%, and water) were tested for osmolarity and pH. Spectrophotometry was used to determine absorbance properties of 27 solutions. Irradiance emission spectra of seven endoillumination light sources and fiber-optics were compared with dye absorbance curves. Results Dye osmolarity in saline solution and glucose 5% varied widely (257-385 mOsm) and was lower (0-54 mOsm) when dyes were dissolved in water. Dyes diluted in three solvents showed pH values varying from 2.6 to 9.85. ICG, LG, TB, BroB, CR, and IC demonstrated different absorbances, depending on the solvent. BriB and FG showed similar absorbance curves with different solvents. Spectrophometric analysis showed that all dyes except ICG had remarkable spectral overlap with the light sources. Among endoillumination fiber-optics, overlap was greatest with dual-output illumination with an integrated laser pathway and least with a mercury vapor lamp. Conclusions Vital dyes showed variable osmolarity and pH, which also depended on the solvent used. Interaction of light from endoillumination source and vital dye may increase or decrease the risk for toxicity, making appropriate selection of both a desirable way to minimize the risk for phototoxic effects.

Coronary artery disease is one of the l wide. lipoprotein(a) [Lp (a)] is a cholesterol rich plasma lipoprotein Its structure and composition closely resembles low density lipoproteins (LDL). Elevated Lp (a) is the most common familial lipoprotein disorder in patients with premature Coronary Artery Disease (CAD). Objective: To study the pattern of plasma LP(a) levels in Sudanese patients who presented with coronary artery disease [CAD]. Material and Methods: This is a case control study. 30 patients randomly se admitted to the coronary care unit [C.C.U] in Elshaab Teaching Hospital with acute coronary syndrome in the period from April 2004 to July 2005 while 30 patients with non ischaemic cardiac problems admitted to the same ho randomly selected as a matched control group. Serum LP(a), cholesterol and low C) concentrations were determined using the conventional enzymatic colorimetric methods. Results: LP(a), cholesterol and LDL lev respectively]. Lp(a) is also high in patients blew 60years of age. High LP(a) correlates with high cholesterol, LDL and other risk factors. The role of Lp(a) as an independent 15 patients with no other risk factors had high LP(a) level. Conclusion: This study demonstrated significant Lp(a) level in patients with other risk factors of CAD [including cholesterol and LDL].

Poliovirus type 2 Sabin mutants were selected for drug resistance and dependence by plating on HeLa cell monolayers in the presence of 3(2H)-isoflavene, a compound related to dichloroflavan, which prevents the shut-off of host translation and poliovirus RNA and protein synthesis. The drug-resistant mutants grew equally well in the presence and in the absence of the drug, while the drug-dependent mutants only grew in the presence of the compound. One dependent and one resistant mutant were characterized biologically in more detail. The resistant mutant did not exhibit thermolability. The mild thermolability exhibited by the dependent mutant was not affected by the addition of 3(2H)-isoflavene, indicating that the substance does not bind the poliovirus type 2 Sabin capsid. The translation of viral proteins and the shut-off of host protein translation during cell infection were not inhibited in either mutant. In the absence of the drug, the cleavage of the precursor VPO, a step in virus protein processing, was affected in the dependent mutant. The dependence of the mutant on the drug was due to the inability of 75S empty particles to reach maturation: our results strongly suggest that this phenomenon is strictly dependent on the reduction of RNA synthesis, confirming the existence of a dynamic equilibrium between RNA production and genome encapsidation during the poliovirus replication cycle.

We read with interest the article by Schumann et al ,1 who have reported the ultrastructural analyses of internal limiting membrane (ILM) specimens after staining with new dye Brilliant Blue G (BBG). In their study, morphological analyses failed to reveal any adverse effects possibly related to BBG. However, they stated that ultrastructural analyses alone may not be sufficient to allow definite conclusions on the safety of a vital dye used for macular surgery. Here we report the effects of accidental subretinal migration of BBG for ILM identification during vitrectomy for epiretinal membrane (ERM). A 56-year-old man had decreased visual acuity and metamorphopsia. He had an idiopathic ERM, and the best-corrected visual acuity (BCVA) measured by the Early Treatment Diabetic Retinopathy Study chart was 1.0 logMAR (Snellen equivalent 6/60). Pars plana vitrectomy and ERM peeling …