Large-scale opacification of a hydrophilic/hydrophobic intraocular lens.

PURPOSE: To determine the prevalence and risk factors related to the opacification of the LS-502-1 intraocular lens. METHODS: Cross-sectional study including patients submitted to cataract surgery between January 2010 and March 2012, with implantation of the LS-502-1 intraocular lens. Past medical history was registered and a complete ophthalmologic evaluation, that included best-corrected visual acuity, slit-lamp examination and fundoscopy, was performed. Anterior segment photographs were taken whenever intraocular lens opacification was present. RESULTS: One hundred and sixty-nine eyes of 154 patients were included, mean age 78.5 ± 7.9 years. The average follow-up after intraocular lens implantation was 65.6 ± 10.0 months. Intraocular lens opacification was seen in 53.3% (n = 90) and presented as one of four different patterns: peripheral (15.6%, n = 14), central (4.4%, n = 4), diffuse (71.1%, n = 64) and superficial white deposits (8.9%, n = 8). There was no statistically significant association with systemic or ophthalmic conditions. In patients with bilateral implantation, intraocular lens opacification in one eye was significantly related to intraocular lens opacification in the fellow eye. A significant variability in opacification was found across intraocular lens serial numbers: the odds ratio for opacification in intraocular lens with serial number beginning with 200003 was 6.0 when comparing with the remaining lenses. CONCLUSION: The opacification prevalence of the LS-502-1 intraocular lens was 53.3%, which is the highest ever described for any intraocular lens model. Our results suggest that this occurrence is secondary to an interaction between unknown patient variables and problems related to intraocular lens manufacturing and storage procedures.

Molecular dynamics simulation and binding free energy studies of novel leads belonging to the benzofuran class inhibitors of Mycobacterium tuberculosis Polyketide Synthase 13.

In this work, the binding mechanism of new Polyketide Synthase 13 (Pks13) inhibitors has been studied through molecular dynamics simulation and free energy calculations. The drug Tam1 and its analogs, belonging to the benzofuran class, were submitted to 100 ns simulations, and according to the results obtained for root mean square deviation, all the simulations converged from approximately 30 ns. For the analysis of backbone flotation, the root mean square fluctuations were plotted for the Cα atoms; analysis revealed that the greatest fluctuation occurred in the residues that are part of the protein lid domain. The binding free energy value (ΔGbind) obtained for the Tam16 lead molecule was of -51.43 kcal/mol. When comparing this result with the ΔGbind values for the remaining analogs, the drug Tam16 was found to be the highest ranked: this result is in agreement with the experimental results obtained by Aggarwal and collaborators, where it was verified that the IC50 for Tam16 is the smallest necessary to inhibit the Pks13 (IC50 = 0.19 µM). The energy decomposition analysis suggested that the residues which most interact with inhibitors are: Ser1636, Tyr1637, Asn1640, Ala1667, Phe1670, and Tyr1674, from which the greatest energy contribution to Phe1670 was particularly notable. For the lead molecule Tam16, a hydrogen bond with the hydroxyl of the phenol not observed in the other analogs induced a more stable molecular structure. Aggarwal and colleagues reported this hydrogen bonding as being responsible for the stability of the molecule, optimizing its physic-chemical, toxicological, and pharmacokinetic properties.

Streptococcus mutans in Mother-Child Dyads and Early Childhood Caries: Examining Factors Underlying Bacterial Colonization.

This study investigated the association between colonization of mother-child dyads with Streptococcus mutans (SM) and early childhood caries (ECC), with consideration of the mediator and confounders, using a theoretical model. Four hundred mothers and their children from São Luís, Brazil, were included in the study. A diagram based on directed acyclic graphs was elaborated to analyze the association between SM colonization of the mother, mediated by child SM, and ECC. Other maternal (socioeconomic, waist circumference, sugar consumption, DMFT index, and visible plaque) and child factors (sugar consumption, visible plaque, and child age) composed the theoretical model. A total effect model (maternal SM on ECC) and a direct effect model, adjusted by the mediation effect of child SM (maternal SM via child SM) on ECC, were analyzed. The outcome of interest in this study was ECC (number of teeth with caries experience, dmft), which was analyzed as a discrete variable by Poisson regression. The Paramed test was used to analyze mediation. The following variables were associated with ECC in the total effect model: maternal SM, maternal waist circumference ≥80 cm, DMFT, maternal visible plaque, child age ≥4 years, and increased sugar consumption of the child (>3 times/day). In the direct effect model, high maternal SM levels remained associated with ECC, while moderate and high colonization of the child with SM was also associated with ECC. Child SM colonization just partially mediated the effect of maternal SM on ECC (33%). Thus, factors other than the mechanism of bacterial colonization should be considered in mother-child dyads, including eating habits, oral hygiene practices, and a family history of caries.

The potential of cashew gum functionalization as building blocks for layer-by-layer films.

Cashew gum (CG), an exudate polysaccharide from Anacardium occidentale trees, was carboxymethylated (CGCm) and oxidized (CGO). These derivatives were characterized by FTIR and zeta potential measurements confirming the success of carboxymethylation and oxidation reactions. Nanostructured multilayered films were then produced through layer-by-layer (LbL) assembly in conjugation with chitosan via electrostatic interactions or Schiff bases covalent bonds. The films were analyzed by QCM-D and AFM. CG functionalization increased the film thickness, with the highest thickness being achieved for the lowest oxidation degree. The roughest surface was obtained for the CGO with the highest oxidation degree due to the predominance of covalent Schiff bases. This work shows that nanostructured films can be assembled and stabilized by covalent bonds in alternative to the conventional electrostatic ones. Moreover, the functionalization of CG can increase its feasibility in multilayers films, widening its potential in biomedical, food industry, or environmental applications.

You are what you eat: ophthalmological manifestations of severe B12 deficiency.

Severe B12 vitamin deficiency due to diminished dietary intake is a known cause of severe pancytopenia with bleeding diathesis. The authors report a case with sudden-onset bilateral vision loss, severe pancytopenia and multiple organ failure secondary to B12 vitamin deficiency in a patient with a strict vegetarian diet. On funduscopic examination the patient had multiple bilateral exuberant haemorrhages in all retinal layers. Five months after presentation, he had a complete visual recovery without ophthalmological intervention.

Anterior Chamber Epithelial Cyst After Uneventful Deep Anterior Lamellar Keratoplasty.

PURPOSE: To report the case of an anterior chamber epithelial cyst after uncomplicated deep anterior lamellar keratoplasty (DALK) treated with a tissue-sparing surgical technique. METHODS: A 35-year-old female patient underwent DALK in her OS because of stage IV keratoconus. The surgery was uneventful, and 3 months postoperatively, best-corrected visual acuity (BCVA) was 20/25. By the sixth postoperative month, a cystic iris lesion was noticed. The lesion grew progressively larger, and BCVA dropped to 20/63 in OS. Cyst excision was performed. RESULTS: No complications possibly related to the surgery were observed. Two years later, BCVA was 20/25 in OS, and there were no signs of cyst recurrence. Histopathological examination of the lesion showed an epithelial implantation cyst. CONCLUSIONS: An anterior chamber epithelial cyst is a sight-threatening condition that may occur after DALK. In selected cases, a conservative surgical approach is an effective treatment option, conveying excellent functional and anatomical outcomes.

Efficacy and safety of postvitrectomy intravitreal triamcinolone therapy for diabetic macular edema.

PURPOSE: After vitrectomy, diffusion and clearance rates of numerous drugs are increased, leading to a shorter intravitreal half-life. This raises doubts about the efficacy of intravitreal therapies, as retina specialists generally believe that a shorter half-life compromises the drugs' therapeutic effect. We conducted a study to evaluate the functional and anatomical effect of intravitreal triamcinolone acetonide therapy (IVTA) in previously vitrectomized eyes with diabetic macular edema (DME). METHODS: In this retrospective, multicenter case series study including vitrectomized patients with DME who underwent IVTA injections, central macular thickness (CMT) measured with spectral-domain optical coherence tomography and best-corrected visual acuity (BCVA) in Early Treatment Diabetic Retinopathy Study letters were evaluated after each procedure. All relevant medical data were collected, including previous ophthalmologic treatments and comorbidities. RESULTS: Twenty vitrectomized eyes of 20 patients, mean age 58.1 years (range 40-72 years), were enrolled in the study. All patients presented DME and received at least one IVTA injection. Mean time between pars plana vitrectomy and IVTA was 12.9 ± 8.7 months. Mean pretreatment and posttreatment CMT was 438.8 ± 90.8 µm and 301.2 ± 76.2 µm, respectively, a difference that reached statistical significance (p<0.001). Mean gain in BCVA letter score was 7.83 ± 14.9 letters after treatment (p = 0.039). Mean intraocular pressure was significantly increased after IVTA (17.2 ± 1.9 mm Hg at baseline vs 21.2 ± 4.59 mm Hg after IVTA, p = 0.002). CONCLUSIONS: A positive anatomical and functional effect was observed in our cohort. Our results suggest that, despite prior vitrectomy, triamcinolone remains a valid therapeutic approach for eyes with persistent DME. Further prospective randomized studies with larger patient samples are needed to validate this conclusion.

Endogenous endophthalmitis secondary to erysipelas.

A 64-year-old woman with chronic right arm lymphoedema presented with progressive and painful vision loss in the right eye following diagnosis of erysipelas in the ipsilateral arm. Visual acuity was light perception. Biomicroscopy revealed marked conjunctival injection, decreased corneal transparency and an inflammatory mass in the anterior chamber, which precluded fundoscopy. The ocular ultrasonography features were consistent with acute endophthalmitis, and the patient was admitted to the hospital. A systemic evaluation, including complete physical examination, echocardiography and blood tests, ruled out other sources of infection besides the cutaneous site. Blood cultures were positive for group A Streptococcus. A diagnosis of unilateral acute endophthalmitis due to group A Streptococcus bacteraemia secondary to erysipelas was made and successfully treated with optimal medical care, including prompt intravitreal and systemic antibiotic administration. Despite resolution of the infectious process, visual acuity did not improve.

Myocardial remote ischemic preconditioning: from pathophysiology to clinical application.

Short periods of myocardial ischemia followed by reperfusion induce a cardioprotective mechanism when the myocardium is subsequently subjected to a prolonged period of ischemia, a phenomenon known as ischemic preconditioning. As well as its application in the myocardium, ischemic preconditioning can also be induced by brief interruptions of blood flow to other organs, particularly skeletal muscle. Transient ischemia induced noninvasively by inflating a cuff on a limb, followed by reperfusion, helps reduce the damage caused to the myocardium by interruption of the coronary circulation. Remote ischemic preconditioning involves activation of humoral and/or neural pathways that open mitochondrial ATP-sensitive potassium channels in the myocardium and close mitochondrial permeability transition pores, making cardiomyocytes less vulnerable to ischemia-induced cell death. This cardioprotective mechanism is now being translated into clinical practice, with positive results in several clinical trials in coronary artery bypass surgery, surgical repair of abdominal aortic aneurysms, valve replacement surgery and percutaneous coronary intervention. However, certain factors weaken the subcellular mechanisms of preconditioning - age, comorbidities, medication, anesthetic protocol - and appear to explain the heterogeneity of results in some studies. Detailed understanding of the pathways involved in cardioprotection induced by ischemic preconditioning is expected to lead to the development of new drugs to reduce the consequences of prolonged ischemia.

Ryanodane diterpenes from two Erythroxylum species.

Ryanodane diterpenes, named 14-O-methyl-ryanodanol and ryanodanol, were isolated from ripe fruit of Erythroxylum passerinum. Compound 2 was also found in the leaves of this species, while 1 was obtained from the leaves of E. nummularia. Compound 1 showed insecticidal activity against Aedes aegypti larvae.