Cool phaco--new option in cataract surgery

PURPOSE: The aim of this paper is to present an alternative method of phacoemulsification. MATERIAL AND METHODS: Bimanual phacoemulsification through two paracenteses was performed in 15 eyes. After cataract removal intraocular lenses were implanted into the capsular bag through a small paracentesis (less than 2 mm). RESULTS: Anatomical and functional results were good in all cases. After comparison with conventional phacoemulsification we concluded, that the bimanual technique shortens the time of ultrasounds usage and reduces postoperative astigmatism. CONCLUSIONS: Phacoemulsification performed through two paracenteses can be the next step in cataract surgery development.     

Choroidal detachment--pathogenesis, etiology and clinical features

Serous choroidal detachment is characterized by exudative detachment of the retina and choroid following leakage of fluid from the choriocapillaris into suprachoroidal space. This accumulation of fluid has been known to be a complication of various intraocular surgeries (cataract, glaucoma and retinal detachment surgery), where hypotony is combined with postoperative inflammation. Among other non surgical conditions associated with uveal effusion are idiopathic (uveal effusion syndrome, microphthalmia) and inflammatory diseases (scleritis, sympathic ophthalmia, pars planitis, Harada's disease). Idiopathic serous detachment of choroids is caused by scleral abnormalities associated with hypoplasia or partial absence of the vortex venous system. The most cases of postoperative choroidal detachment resolve spontaneously. Resolution is usually associated with rapid normalization of the intraocular pressure and reduction of intraocular inflammation. The natural course of idiopathic condition is variable but tends to be prolonged with remissions and exacerbations. Surgical management involving vortex vein decompression and/or sclerotomy is the most effective treatment in this patients.     

Recurrent ventricular fibrillation during a febrile illness as the first manifestation of Brugada syndrome--a case report

A case of a 33-year-old male who was admitted to the hospital due to recurrent ventricular fibrillation during a febrile illness is presented. Initially, the patient was diagnosed with acute myocardial infarction and received thrombolytic treatment. Echocardiography and coronary angiography were normal. Right precordial ECG leads recorded one and two intercostal spaces higher than normal as well as ECG obtained following ajmaline administration revealed a typical Brugada pattern.     

Diminished toxicity of C-1748, 4-methyl-9-hydroxyethylamino-1-nitroacridine, compared with its demethyl analog, C-857, corresponds to its resistance to metabolism in HepG2 cells

The narrow "therapeutic window" of anti-tumour therapy may be the result of drug metabolism leading to the activation or detoxification of antitumour agents. The aim of this work is to examine (i) whether the diminished toxicity of a potent antitumour drug, C-1748, 9-(2'-hydroxyethylamino)-4-methyl-1-nitroacridine, compared with its 4-demethyl analogue, C-857, results from the differences between the metabolic pathways for the two compounds and (ii) the impact of reducing and/or hypoxic conditions on studied metabolism. We investigated the metabolites of C-1748 and C-857 formed in rat and human liver microsomes, with human P450 reductase (POR) and in HepG2 cells under normoxia and hypoxia. The elimination rate of C-1748 from POR knockout mice (HRN) was also evaluated. Three products, 1-amino-9-hydroxyethylaminoacridine, 1-aminoacridinone and a compound with an additional 6-membered ring, were identified for C-1748 and C-857 in all studied metabolic systems. The new metabolite was found in HepG2 cells. We showed that metabolic rate and the reactivity of metabolites of C-1748 were considerably lower than those of C-857, in all investigated metabolic models. Compared with metabolism under normoxia, cellular metabolism under hypoxia led to higher levels of 1-aminoacridine and aza-acridine derivatives of both compounds and of the 6-membered ring metabolite of C-1748. In conclusion, the crucial role of hypoxic conditions and the direct involvement of POR in the metabolism of both compounds were demonstrated. Compared with C-857, the low reactivity of C-1748 and the stability of its metabolites are postulated to contribute significantly to the diminished toxicity of this compound observed in animals.     

Seizure frequency and bioelectric brain activity in epileptic patients in stable and unstable atmospheric pressure and temperature in different seasons of the year--a preliminary report

Background and purposeAn epileptic seizure is a sum of exogenous and endogenous factors affecting an epileptic focus. The aim of the study was to examine the influence of changes in atmospheric pressure and temperature on the increase in the frequency of seizures and changes in EEG in epileptic patients.Material and methodsThe study included 30 epileptic patients (aged 19–54) reporting the influence of changes in weather conditions on the increase in the frequency of seizures for at least 2 years. EEG was performed twice each season at the time of stable and unstable weather conditions.ResultsIn stable and unstable weather conditions, epileptic changes in EEG were most often found in winter (in 43.3% and 63.3% of patients, respectively). Unstable weather conditions increased the proportion of patients with epileptic changes in EEG also in the other seasons. Unstable weather conditions caused an increase in the frequency of seizures in 40% of patients in spring, 43.3% in autumn, 40% in winter and in approximately 7% in summer.ConclusionsIn spring, autumn and winter, unstable weather conditions cause an increase in the frequency of seizures in almost half of the epileptic patients but only in 7% in summer. The increase in frequency of seizures in unstable weather conditions did not correspond in all patients with increase of changes in EEG. The higher proportion of epileptic patients with changes in EEG in unstable weather conditions in all seasons suggests an impact of these conditions on subclinical seizure discharges in this period.     

Nucleosome positioning by genomic excluding-energy barriers

Recent genome-wide nucleosome mappings along with bioinformatics studies have confirmed that the DNA sequence plays a more important role in the collective organization of nucleosomes in vivo than previously thought. Yet in living cells, this organization also results from the action of various external factors like DNA-binding proteins and chromatin remodelers. To decipher the code for intrinsic chromatin organization, there is thus a need for in vitro experiments to bridge the gap between computational models of nucleosome sequence preferences and in vivo nucleosome occupancy data. Here we combine atomic force microscopy in liquid and theoretical modeling to demonstrate that a major sequence signaling in vivo are high-energy barriers that locally inhibit nucleosome formation rather than favorable positioning motifs. We show that these genomic excluding-energy barriers condition the collective assembly of neighboring nucleosomes consistently with equilibrium statistical ordering principles. The analysis of two gene promoter regions in Saccharomyces cerevisiae and the human genome indicates that these genomic barriers direct the intrinsic nucleosome occupancy of regulatory sites, thereby contributing to gene expression regulation.     

Effect of metyrapone on the fluoxetine-induced change in extracellular dopamine, serotonin and their metabolites in the rat frontal cortex

Major depression is frequently associated with the hyperactivity of the hypothalamic-pituitary-adrenocortical axis, and glucocorticoid synthesis inhibitors have been shown to exert antidepressant action. Metyrapone (an inhibitor of the enzyme 11-β-hydroxylase) has been found to be effective as an adjunctive therapy in combination with other antidepressants (ADs) in both treatment-resistant depression and animal models. To understand the mechanism of the clinical efficacy of a combination of an AD and metyrapone in treatment-resistant depression, the present study was aimed at determining the influence of fluoxetine (FLU; a selective serotonin reuptake inhibitor) and metyrapone, given separately or jointly, on the extracellular level of dopamine (DA), serotonin (5-HT) and their metabolites in rat frontal cortex of freely moving rats using microdialysis and high performance liquid chromatography (HPLC) with electrochemical detection. FLU (10 mg/kg) given alone increased the extracellular level of DA and 5-HT in the rat frontal cortex. Metyrapone (100 mg/kg) alone did not change the level of monoamines. A combination of FLU and metyrapone produced the same change in the efflux of both DA and 5-HT as did FLU alone. However, the latter combination (FLU and metyrapone) produced significantly bigger increases in the levels of extracellular DA metabolites (3,4-dihydroxyphenylacetic acid, homovanillic acid) and a 5-HT metabolite (5-hydroxyindoleacetic acid) than did FLU alone. The above findings suggest that--among other mechanisms--increases in the levels of extracellular DA and 5-HT metabolites may play a role in the enhancement of FLU efficacy by metyrapone, and may be of crucial importance to the pharmacotherapy of drug-resistant depression.